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# Difference between revisions of "Guide For Student Wizards"

This is a living guide, if there are any mistakes or updates or new information you want to add, please feel free to!

## Newbie Gear

• You should get a wizard's hat
• Get a small leather shield for casting magic shield spells
• For casting certain spells:
• Some containers and scabbards to hold your things:
• Large backpack or black backpack to hold your items
• If you can get a hunter's pack, get that instead of the backpack to also hold your staff and items
• A staff harness to hold your staff if you do not have a hunter's pack
• An optional scabbard like a witchy garter to hold your knife for cutting up things.
• For healing yourself:
• Get some healing tea from a local player shop, some of them sell newbie healing teas for cheaper prices
• For the free option, you can get a bottle yourself and fill it up with some blue water
• Healing tea will gradually heal you over time until the effects run out while blue water is an instant healing effect
• Remember to type drink 1/100 bottle or whatever container is holding the water/tea as that should be enough to heal you
• You can also look into bandages but it needs 25 levels of crafts.medicine.firstaid and another player to teach it to you
• For melee combat weapons, check out:

## Spells

• Check out which spells you want: Spells/Wizard and where to find them: Spellbooks
• Wizard spells have nicknames that the wizard and general player community uses, check them out here: Wizard spell nicknames
• Theres a limit to how many spells can be remembered in your mindspace, you will have to forget spells if you find that you can't remember new ones
• Note that spells need to pass each stage which goes through a skillcheck for each skill that the spell needs.
• You can use the spellcheck command or check out the specific spell's page on the wiki, there will usually be a coloured Spellcheck table showing the chances of success for each skill needed in each stage of the spell.
• If you suddenly receive a lot of damage from like another spell or a special attack or just a normal attack, it can disrupt the casting of your spell.

### For common spell components

Components chapter in Elanor's Guide to the Disc is also a good but bit outdated resource

• For Memories of a Vicious Chicken:
• You can buy a pet chicken and pluck feathers from the chicken.
• You can usually find chickens to kill wandering Lancre Town or in Ephebe or chickens at the Muckloe Farm in the Ramtops or at the farm in Dinky, although those chickens in Dinky will be needed for a quest.
• If you can, you can also kill wizard npcs as they usually carry chicken feathers in their satchels, this is however not recommended as wizard npcs can be dangerous to kill and also the wizards in Ankh-Morpork might explode when they die and the wizards in other locations tend to run when dying so you have to pursue them.
• For KOF:
• For TPA:
• Look at the ash page
• You can usually get ashes by sweeping ashes from a local smithy.
• You will also need a broom for sweeping, I recommend getting a push broom (https://quow.co.uk/cow.php?t=Items&s=push+broom) which can be easily bought or an small ornamental broom if you can find one.
• Make sure you type take handful of ash when casting TPAs so you don't end up using up all your ash in one go.
• Some more complicated or more dangerous way to get ashes and not recommended unless you have to:
• You can also scoop ashes at midnight at the Phoenix statue in DJB,
• gather vampire ash in Escrow
• You can also use a shovel to gather ash at the campfire near Hillshire or at the Bandit Camp
• Some stoves can make ash from burning wood and paper can be burned into ash
• For lightable torches:
• For PFG:
• You can collect eyes from dead bodies by holding a knife (stilettos don't work) and typing get eyes from bodies
• You can pickle the eyes for later so the eyes don't decay using a small stick summoned using Collatrap's Instant Pickling Stick
• For CCC:
• Check out the Ball of congealed sap page for instructions on how to obtain the sap for free. In short you can:
• squeeze from trees in Bes Pelargic (Azure Promenade, Green Street)
• lance tree with knife in Ephebe on cedar trees
• Otherwise can be bought from Institute of Illusory Learning component shop, AoA component shop, or up to 20 from Tarnach's at the Magic Emporium in AM
• Usually player shops will also sell CCC components together so you can check out those but it will be more pricey.
• For beeswax candles:
• For sulfur blocks:
• Sulfur blocks can be made from sulfur powder
• You can mine for sulfur powder in the Copperhead mines using a pickaxe but this can be dangerous so recommended for more mature players
• The blocks can be made using the sugar press in Millie Hopgood's cottage in Slice (west side of town), the steps are:
• put 10 handfuls of powder in press
• push lever on press
• get all from press
• 10 handfuls of sulfur powder makes 8 blocks

### Tips & Tricks for Spells

• MWLC:
• Blorples:
• Jewellery used as blorples can degrade as you use it for JPCTs
• You can fix the jewellery at certain smithies shown on the Smithy page.
• Make sure to advance some skills in Crafts.smithing for fixing jewellery
• You can ask on the igame or one talker channels if someone can teach you the fix command.
• You can also buy blorples at some player shops if you have some money and don't want to go around blorpling.
• If you starting to find you are carrying lots of blorples and taking up space in your main container/bag, you can have a specific container or smaller satchel you put in your main bag to hold the blorps to make it easier to find and sort them, you can identify this as blorp_pouch like so:identify satchel as blorp_pouch
• JPCT:
• Misports (where you don't get teleported to where you want) and burning or rumbling doors are normal when using JPCTs.
• Before you open the door, type look portal to check if its not burning, you might also want to wait a bit to see if the door rumbles or wobbles on its own.
• Then type open portal and look enter portal before you enter the door to see if it is the location you want, sometimes you might misport to a dangerous area so this is always a good practice.
• If you are using aliases to create portals to a destination, you could set a category like so: alias set category <portal alias> portal so that you can find all your portal-related aliases in one place by typing alias category portal if you do not remember them
• PFG and other area attack spells:
• PFGs won't affect lights summoned using MWLC, other group mates and pets
• Certain NPCs run away from spells like Pragi's Fiery Gaze before the spell is done casting so be careful, you can invest in skills for Myrandil's Vicious Seizure so you can hold them down.
• A method for wizards to kill large amounts of enemies is to attack certain NPCs who pursue you and don't run away from PFGs or similar spells and then gather them into one room and then cast an area attack spell like PFG. This is only recommended to try when you are confident that you can cast PFGs without failure and also can deal enough damage using PFGs. Also this is best done in a group where you are leading the group and other group members assist you.
• PFGs and other area attacks don't tend to do as much damage earlier on and its quite common to fail before you have meet all the skill requirements so it's recommended to rely on melee or KOF when you're young.
• Be careful using PFGs in areas where you are lower level than the NPCs as you can quickly get overwhelmed
• Make sure you avoid using it in Djelibeybi where you might end up killing a cat or priest(ess).
• Try to shield up with TPAs, EFFs and also CCC when possible while casting.
• TPA and other magical protection spells:
• You can type shields to see if you are protected by TPAs, EFFs and CCCs etc.
• Typing group shields or group status will show similar results for you and your groupmates if you are in a group.
• If your TPA is flickering yellow, it means it is about to break if it is hit again, be prepared to run 2 rooms somewhere else and then TPA yourself again if possible
• Sometimes TPAs break on their own without any combat so watch out!
• EFF:
• Note that EFF swooping down to block consumes your AP and thus if you are facing multiple enemies, you will find that you won't even be able to do melee attacks because your action points is all consumed up.
• Spells however can be cast no matter the loss in action points, however casting spells will also lose action points.
• Special attacks can knock down your EFF shield, have an alias prepared for these scenarios like alias ts take shield and then run 2 rooms away and then cast EFF again as some NPCs will pursue
• You can enchant your EFF shield to add some durability and make sure to fix your shield if it is getting too damaged
• KOF:
• Certain NPCs also run away from KOF before it is done casting, especially some NPCs in Bes Pelargic
• KOF can be cast on multiple targets, you can do this by typing cast Kamikaze Oryctolagus Flammula on target_1,target_2, note that it costs 100 extra GP per another target
• NES:
• Certain NPCs also run away from NES before it is done casting such as some NPCs in Djelibeybi

## Making some money

As a member of the wizard's guild, you might find yourself needing more and more money to buy components, advance skills and buy other useful items.

Here are several ways a wizard can earn money in the beginning:

• Collecting sacks and killing rats for tails in the Pepper Pot:
• It is quite easy to earn several dollars just collecting sacks in the maze
• You should have a knife on you if you want to collect and sell rat tails
• It is recommended to read up on Pepper Pot before entering
• Doing Missions and Jobs:
• Places like the AM Job Market, doing Takeaway jobs and certain restaurants like the McSweeney Restaurants offer delivery jobs, restaurant jobs and other missions which can be quite profitable
• Able to use JPCT and blorps are recommended to do this as you would be likely travelling around a lot
• There might be other skill requirements for the more complicated jobs
• Killing and Looting:
• You can travel to newbie areas like Ohulan Cutash which have plenty of NPCs to kill and loot
• Items can then be fenced or sold in general stores
• You should advance a melee skill and a defence skill and have learnt to use TPA.
• Considering the NPCs there should also generally show that most NPCs there are weaker before you start killing.
• Picking up trash:
• Sto Lat is a good area to pick up clothes, money and loot left on the ground from NPC vagrants/wizards killing off other NPCs
• You can sell to the general store or fence to Ragman
• This is a way to earn some quick cash but sometimes the area might have already been picked clean
• Bleak Prospect, etc. are also similar areas but much more dangerous and not recommended.
• Creating or gathering components to sell:
• You can always gather or make components (pickled eyes/carrots, Pfga amulets, lightable torches, beeswax candles, etc) and sell these to Tarnach's in Sator Square.
• Ring the bell at Tarnach's and someone might get around to helping you sell those items
• Ability to use JPCT and blorps are recommended to do this as you would be likely travelling around a lot
• Selling your scrolls to a player shop:
• If your magic.items.scroll skill reaches level 51, you can buy tiny or small packets from a shop in the Plaza of Broken Moons, as well as a few chapbooks and a quill, pen, or pencil.
• There's a free pen in the wastebasket at the Academy of Artificers secretary office. There is a free ink vial that can be found in the same room on the table for the pen
• You can look up who owns a player shop from the wiki link and offer your services if the owner is a non-wizard or does not have the time to scribe scrolls.
• Some pay better than others, some let you set your own price and sell the scroll packets for a 10% or other random markup, and some have fixed pricing for how much you can sell your 4-pack of scrolls for.
• On average, you should be making roughly $10 AM per 4-pack packet, at least for JPCT. It is recommended to sell JCPT scrolls. • The rates are lower for other spells like CCC, EHA, FFM, FNP, GFR, TPA, and not all player shops carry these. • Doing Puzzles for the AM Daily • Usually royals (equivalent to 100 AM dollars) are given out as prizes for participating and winning puzzles/games for the AM daily which come out each month • You should send a mudmail to Jeanie if you have an answer to win a prize • Check out Making money for more ideas ## Aliases • See Alias if you're not sure what an alias is • Create an idle alias, you you can use to TM skills while idling, see: Idlechasing aliases, Idlechasing for new characters and Idlechasing for wizards • There are some good general aliases in General aliases • Use the recommended kill alias and check out Combat aliases • Useful aliases from other players: • You can type alias mdt map door text and then type mdt to quickly check the NPCs around you depending on your perception • For teleporting, alias port cast Jogloran's Portal of Cheaper Travel on$*$ • For TPA, alias tpa take shield from component_pouch; take handful of ash from component_pouch; cast Transcendent Pneumatic Alleviator on$*$; put shield in component_pouch • For KOF, alias kof take carrot,torch from component_pouch; cast Kamikaze Oryctolagus Flammula on$*\$;put torch in component_pouch
• For other wizard aliases, you can check out Guild_aliases#Wizards

## Choosing an Order

Review Wizards' Guild#Orders before reading this section

When it comes to the time to choose an order, here is a brief overview of the orders, the hedge orders are similar:

• Lodgers are a good generalist order, very popular specifically because of its very good and diverse primaries.
• Unbroken Circle focuses upon elemental skills first and foremost and is favoured strongly by people who want to focus on offensive casting, especially spells like Pragi's Fiery Gaze or Nargl'frob's Empyrean Spear (lightning bolt!).
• Hoodwinkers focuses upon illusions and trickery, but has a good generalist bent to it, especially having a good spread for some niche but useful spells. They're the best at Eha.
• Silver Star is for if you really like crafts, but they suffer at everything else because they get barely any methods.
• Seers is great if you are interested in scrying and also have some useful general primaries for spells as well.
• Shadow focuses on demonology and is the order to go for if you want to cast Doctor Kelleflump's Deadly Demon.
• Midnight are necromancers, can speedrun to Grg if you care for having your own skeleton minion.
• Last Order may as well be a second Lodgers but with methods focusing more on reaching offensive spells.

Usually when it comes down to choosing an order, it is more about your play-style (roleplaying or fighting style, etc.) and also which spells you want to be able to master early on as the primaries each order offers will make it easy to master certain spells.

Your Order's Senior Wizard will usually welcome you into the order when you join, if you have any questions or need further help with the Order, you can ask your Senior Wizard.

Once you join your order, there is usually a club made for the Order that you can join and there may be a newbie chest in the room of your order.

## Wizard Ranks

Once you are able to choose an order, you will see that you have become a First Level Wizard (usually). There are eight levels altogether.

From the First Level to the Fourth Level, you will be given a rank dependant on the mastery of your primaries.

From the Fifth Level to the Eighth Level, these ranks are dependant on the size of your order and usually if someone who is ranked above you dies, you will move up in level.

If you are inactive or do not play for a while, your rank usually drops from between Fifth to Eighth to the Fourth Level or a level that more reflects your primaries.

The Senior Wizard is an elected position and does not abide by these ranks.

## Rearranging

It is recommended that wizards take their time before rearranging and try out spells and different playstyles (melee-focused, casting or more casual) before trying to rearrange. Usually the basic stats (all 13) are good enough for quite some time.

### On Stats

More traditional wizards usually go for a lot of Intelligence at the expense of stats like Wisdom. The upper limits for Intelligence appears to be around 23.

Hp can be a potential life-saver for wizards, tweaking your Constitution and maybe your Strength as well in http://www.bonuses.irreducible.org/hp.php is recommended.

Guild points and their regeneration rates will be helpful for wizards focused on casting spells, this would also mean Both Wisdom and Intelligence should be prioritized with Strength to a lesser degree. Wizards should also play around with this tool: http://www.bonuses.irreducible.org/regen.php

Burden can also be an issue with wizards carrying lots of components, testing with the burden calculator: http://www.bonuses.irreducible.org/burden.php is recommended.

To go beyond these stats for certain spells, wizards should also look towards items such as the bronze helm. This gives the wearer a combination of +3 intelligence, +2 wisdom and -3 constitution while it is worn. Along similar lines is the flat cap, which provides +3 wisdom, +2 intelligence and -3 strength while worn. Both of these items however cannot be worn indefinitely, and will begin to hurt the wearer after a short period, leading to death eventually. Both these items can be purchased from the t-shop. Usually wizards have an alias for taking out these items, wearing them, casting the spell and then taking them off again.

The bonus computer is a great tool to help plan stats and bonuses: http://bonuses.irreducible.org/bonus.php

Below are some practical examples with explanations provided copied from https://artificersanonomyous.webs.com/rearrange.htm which is a more in-depth read on rearranging.

### Rearrange Examples

Poncho
Con 8, Dex 8, Int 21, Str 8, Wis 20
Q. What would you say is the primary reason for your chosen rearrange?
A. Mine is an unusual rearrange for most everybody. Mostly it emphasis magic, most importantly ma.po and the ma.sp.* tree, as well as giving me amazing mindspace and things like perception. However I really wanted to be a teacher and thanks to this rearrange that makes it easier to do.

Thoughts
Con 13, Dex 9, Int 20, Str 14, Wis 9
Q. What would you say is the primary reason for your chosen rearrange?
A. I like the concept of being a wizard that actually plays like a wizard. As opposed to a wizard which is basically a warrior with portal...
Q. So what is it about your rearrange that you feel makes it 'Wizardy'
A. Well it fits my Order near perfectly. Provides good over-all stability for nearly all spells, and excels in the areas such as Elementals, whilst providing quite nice bonuses in Offensive and Defensive.

Con 8, Dex 13, Int 21, Str 12, Wis 11
Q. What is the primary reason for that chosen rearrange?
A. It's a heavy magic rearrange. Huge Int gives good bonuses in all the magic disciplines. I'm reducing con because I can replace ot.he with xp, and I tm elementals nicely - I've already tm'd fire past 300 twice. Getting the dex up will help with the crafts and stealing I like doing as well as magic.
A. I ought to add that my stats have evolved over time. I could not have sustained this rearrange as a younger wizard, but increasing powers mean that I have strategies (and very high levels in certain skills) which compensate for the highly unbalanced stats I now have.
Q. Do you recall your original rearrange?
A. C13 D11 I20 S11 W10, I think.
A. So what I've done is gradually reduce con and redistribute it over the rest. And in the process given up all hope of ever casting JHSD. It's the torches, you know ;)

Tay
Con 8, Dex 12, Int 18, Str 15, Wis 12
Q. What would you say is the primary reason for your chosen rearrange?
A. Because it worked decently for stealing, as well as giving me a nice boost in EHA (Effermhor's Hypersonic Assault) and TIG (Torqvald's Illusion Generatrix)
A. Also, it gave me a fairly decent sword bonus.
Q. So Illusions were something that grabbed your interested from the start then?
A. I was an assassin. Then I learned about TIG, and refreshed.

Con 12, Dex 12, Int 17, Str 14, Wis 10
Q. What would you say is the primary reason for your chosen rearrange?
A. Really, it came from disgust with how weak NES (Nargl'frob's Empyrean Spear) seemed to be, and realizing that a rearrange for JHSD (Journey of the Heavenly Storm Dragon) was just stupid. Stupid for someone at my level who wasn't a circle, I mean. Once I arrived at that conclusion, gimping wis was a pretty easy decision to make. Str went up for good Offensive, and because I tend to carry a lot of stuff.
Q. So your chosen rearrange was based purely on a factor of offensive capabilities then?
A. Offense was the biggest factor. And I do like being able to carry a lot and stay in the 20-30 burden range.
Q. Do you use melee as well?
A. Not very much. If I pragi someone to very bad, I might use the stilettos to finish up with.

Con 13, Dex 14, Int 16, Str 10, Wis 12
Q. What would you say is the primary reason for your chosen rearrange?
A. I was intending to maximize my bonus in magic, specifically in the most used skills (at higher levels, nobody cares what you need for FTF etc.)

Saaur
Con 8, Dex 14, Int 19, Str 14, Wis 10
Q. What would you say is the primary reason for your chosen rearrange?
A. I have high str and dex to carry heavier loads. I have a ‘ok’ wisdom so that I can cast dkdd (Doctor Kelleflump's Deadly Demon). Con I keep low because I can subsidise the skills that use it with xp e.g. elementals and HP. Obviously Str and Dex affect other things like how much you can hold, carry etc that xp can't solve. I wouldn’t go over 19 int seeing as since the change it wont give the same benefit that it used to.

Alatar
Con 18, Dex 9, Int 20, Str 8, Wis 10
Q. What would you say is the primary reason for your chosen rearrange?
A. The sole reason for my rearrange is to cast JHSD

Comments: Alatar's high int/con gave him brilliant elementals bonuses at low levels, which mean he can gain a high mastery of them. Meanwhile the con/int/wis all go into brilliant ma.sp.de. His ma.sp.of bonus is really terrible however, taking a hit to max damage. However I'm inclined to think he's less likely to kill himself with a backfire at that stage which is an upside, as well as the fact that he only has the one skill to pump xp into (ma.sp.of) to 'fix' the bonus.

Horror
Str 20, Int 19, Wis 10, Con 8, Dex 8
Q. What would you say is the primary reason for your chosen rearrange?
A: I wanted high ma.sp.of, to be able to wear armour, and carry a crap load of components.

Mayian (PK)
Con 11, Dex 13, Int 16, Str 17, Wis 8
Q. What would you say is the primary reason for your chosen rearrange?
A. Id say I try to have a balance between my magic skills, and fighting. With my 16 Int I have decent enough bonus's in the spells that I cast, and the rest of my rearrange is geared towards not-great but workable fighting bonuses.

Cripsi (PK)
Con 10, Dex 12, Int 15, Str 13, Wis 15
Q. What would you say is the primary reason for your chosen rearrange?
A. good methods, good tactics/perception, with strength gauntlets i can hold a fair amount of components, and I don't have the best melee in the world but it's enough to get 300 bonuses in melee+defense without needing 600 levels for the 300 bonus.
Q. And how does that end out working for you in the wide world of PK?
A. It worked alright at a surviving level, but as magic is sometimes to slow to fight more experienced PK's it's not the greatest rearrange in the world. i imagine it would be a lot better with more skills, but relying on just one skill tree in PK isn't a good thing, combat is needed to for a wizard (as we don't get faith).

Kripsi (PK)
Con 8, Dex 20, Int 14, Str 15, Wis 8
Q. What would you say is the primary reason for your chosen rearrange?
A. After almost 50 days with Cripsi's rearrange, I could see that relying heavily on magic wasn't working. This rearrange is for combat, so i become a warrior that can remember spells. This is mostly because with magic, i found it gets to good at 300-400 bonuses, in 5 or 6 skills per spell. it doesn't get amazing until 500-600 bonuses, which is a lot more expensive than doing sword/dodge to 500/600 bonuses. so i guess the main reason is that I'll be completely able to fight in PK, and on top of that I'll have magic in my head so no scrolls blowing up on me and more spells than the average PK can really carry around.

## Next Steps

• You can group with other players to kill NPCs as described in Numberchasing, however it is recommended that you have a >= 200 bonus in magic.spells.defensive for casting TPAs and around 2000 hp and can use JPCTs and CCCs. Make sure you have enough ash for casting TPAs on you and your groupmates.
• Join the Club/Faculty club once you reach 10 days of age, there are also usually clubs for the order in which you have decided to join
• Contribute back to the wiki or this guide if you find discrepancies or other things that will be useful! See: Special:UserLogin to register


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# Documents in process

 2020-01-2315:17 [PUBDB-2020-00528] Journal Article et al Correlative x-ray phase-contrast tomography and histology of human brain tissue affected by Alzheimer's disease NeuroImage xxx, 116523 - (2020) [10.1016/j.neuroimage.2020.116523] 2020-01-2315:13 [PUBDB-2020-00527] Journal Article Salditt, T. Time-resolved x-ray phase-contrast tomography of sedimenting micro-spheres Brief treatment and crisis intervention 21(4), 043017 - (2019) [10.1088/1367-2630/ab13c8]   Fulltext: PDF PDF (PDFA); 2020-01-2315:11 [PUBDB-2020-00525] Journal Article et al Multiscale x-ray phase-contrast tomography in a mouse model of transient focal cerebral ischemia Biomedical optics express 10(1), 92 - (2019) [10.1364/BOE.10.000092]   Fulltext: PDF PDF (PDFA); 2020-01-2315:10 [PUBDB-2020-00524] Journal Article et al Contrast enhancement for visualizing neuronal cytoarchitecture by propagation-based x-ray phase-contrast tomography NeuroImage 199, 70 - 80 (2019) [10.1016/j.neuroimage.2019.05.043]   Fulltext: PDF PDF (PDFA); 2020-01-2315:08 [PUBDB-2020-00523] Journal Article Salditt, T. Radiation damage studies in cardiac muscle cells and tissue using microfocused X-ray beams: experiment and simulation Journal of synchrotron radiation 26(4), 980 - 990 (2019) [10.1107/S1600577519006817]   Fulltext: PDF PDF (PDFA); 2020-01-2314:54 [PUBDB-2020-00522] Journal Article et al Time- and momentum-resolved photoemission studies using time-of-flight momentum microscopy at a free-electron laser Review of scientific instruments 91(1), 013109 - (2020) [10.1063/1.5118777] 2020-01-2314:22 [PUBDB-2020-00521] Preprint/Report et al The transverse momentum spectrum of low mass Drell-Yan production at next-to-leading order in the parton branching method [DESY 20-006; arXiv:2001.06488] The transverse momentum spectrum of low mass Drell-Yan (DY) production at low center-of-mass energies $\sqrt{s}$ is calculated by applying transverse momentum dependent (TMD) parton distributions obtained from the Parton Branching (PB) evolution method, combined with the next-to-leading-order (NLO) calculation of the hard process in the MCatNLO method. We compare our predictions with experimental measurements at low DY mass, and find very good agreement. [...] Restricted: PDF PDF (PDFA); 2020-01-2313:45 [PUBDB-2020-00519] Patent et al A multilayer device having an improved antiferromagnetic pinning layer and a corresponding manufacturing method Restricted: PDF PDF (PDFA); 2020-01-2311:30 [PUBDB-2020-00518] Journal Article et al Ghost imaging at an XUV free-electron laser Here we present the results of a classical ghost imaging experiment accomplished at an XUV free-electronlaser (FEL). To perform such experiment at an FEL source each x-ray pulse was transmitted through a movingdiffuser, which created a noncorrelated speckled beam. [...] Restricted: PDF PDF (PDFA); External link: Fulltext 2020-01-2310:22 [PUBDB-2020-00512] Report/Journal Article et al All-Sky Measurement of the Anisotropy of Cosmic Rays at 10 TeV and Mapping of the Local Interstellar Magnetic Field [arXiv:1812.05682] The astrophysical journal / 1 Part 1 871(1), 96 - (2019) [10.3847/1538-4357/aaf5cc]   We present the first full-sky analysis of the cosmic ray arrival direction distribution with data collected by the High-Altitude Water Cherenkov and IceCube observatories in the northern and southern hemispheres at the same median primary particle energy of 10 TeV. The combined sky map and angular power spectrum largely eliminate biases that result from partial sky coverage and present a key to probe into the propagation properties of TeV cosmic rays through our local interstellar medium and the interaction between the interstellar and heliospheric magnetic fields. [...] Restricted: PDF PDF (PDFA);

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# Work energy incline with spring

tiny-tim
Homework Helper
Hi Jason03!

I don't see anywhere "let the maximum additional deformation of the spring be x inches" …

On the right hand side of the energy conservation equation, you're assuming the object is going to be at a height of 0 (in other words, you need to include the final gravity potential energy on the right hand side, if I'm not mistaken). In addition, you're solving for displacement of spring, displacement isn't already found (on the right hand side you already plugged in 'x'?)

so the fact that the spring is compressed 6 in. is not takin into consideration in my equations?

Sorry, didn't catch that's what you're doing (I was looking for an x in the equation to solve for the displacement). But this is really on the wrong side of the equation. It should be on the left side since initially it is displace this amount.

Here's how I would attempt it. First, write your left hand side equation with initial total energy, including spring, kinetic, and gravity potential. Then, on the left hand side, place your final total energy, which should include spring and gravity potential (no kinetic since its stopped). Take 'X' to be your TOTAL (not change) in compression of spring. Find the height change of the box when it goes 'X' distance down the slope. This will be used to find on the right hand side of equation the new gravitational potential energy. Set it all up, and solve equation!

Last edited:
tiny-tim
Homework Helper
so the fact that the spring is compressed 6 in. is not takin into consideration in my equations?
The 6 in is used to calculate the initial energy of the spring.

You need to find the maximal energy of the spring, and then calculate x from that.

this problem is confusing me, would this work for setting up my equ...?

$$\frac{1}{2}MV^2 + \frac{1}{2}KX^2 + mgh = \frac{1}{2}KX^2$$

the left side of the equ would be the block at the top of the incline....should there be gravitationl potential on the right side as someone had said earlier?...that doesnt make sense to me...

tiny-tim
Homework Helper
this problem is confusing me, would this work for setting up my equ...?

$$\frac{1}{2}MV^2 + \frac{1}{2}KX^2 + mgh = \frac{1}{2}KX^2$$

the left side of the equ would be the block at the top of the incline....should there be gravitationl potential on the right side as someone had said earlier?...that doesnt make sense to me...
Hi Jason03!

(btw, don't say "someone" … this is a friendly forum! )

Yes, that's basically correct … you've followed the proecdure that Durato recommended.

Except it shouldn't be $$\frac{1}{2}kx^2$$, it should be kx, shouldn't it?

The gravitational potential can be on the left, on the right, or both, depending on where you put your "zero level" of gravitational potential.

Before you go any further, draw a fresh diagram, with every number or letter that you're going to use marked clearly … if you try to set up an equation like this in your head without a complete diagram, you'll almost certainly make a mistake.

I made my "zero level" for gravitational potential at ground level.....and it is kx^2

so I came up with this

$$\frac{1}{2}(1500\frac{lb}{ft})(.5ft)^2 + \frac{1}{2}(6.2slug)(8\frac{ft}{s}) + (6.2 slug)(32.2\frac{ft}{s^2})(25Sin20) = \frac{1}{2}(1500\frac{lb}{ft})(x)^2$$

so if I solve for x would that be giving me the total compression in x ...or just the compression due to the block hitting it...

Last edited:
tiny-tim
Homework Helper
Hi Jason03!
....and it is kx^2
Yes … sorry … got confused.
$$\frac{1}{2}(1500\frac{lb}{ft})(.5ft)^2 + \frac{1}{2}(6.2slug)(8\frac{ft}{s}) + (6.2 slug)(32.2\frac{ft}{s^2})(25Sin20) = \frac{1}{2}(1500\frac{lb}{ft})(x)^2$$
The question says "bringing the package to rest", so you should assume that the package stays in contact with the spring. That means you have to include x in your h.
so if I solve for x would that be giving me the total compression in x ...or just the compression due to the block hitting it...
x, as you have written the equation, is the total compression (so the problem starts with x = .5ft).

Apart from that (and apart from the fact that I don't really understand the units!), the equation looks ok.

didnt I include x in my h by the term (25 sin 20)?........

h = xsin25 = 25sin20 = 8.5 feet

tiny-tim
Homework Helper
h = xsin25 = 25sin20 = 8.5 feet
sin25?

x (or x + 0.5) is the compression of the spring. 25 is the original distance of the package.

If the package compresses the spring by x (or x ± 0.5), then that has to be added to the 25 before finding h.

ohhh i see what your saying....so the angle is 20 and the x traveled is 25 so:

$$h = (25+x)sin 20$$

so would that be

$$h = 7.5 + xsin20$$

Last edited:
tiny-tim
Homework Helper
$$h = (25+x)sin 20$$

so would that be

$$h = 7.5 + xsin20$$
Yes, except it's $$h = 8.5 + xsin20$$.

And with that definition of x, you now have to use 1/2k(x+h)^2.

The 'h' that you're defining is the vertical distance from the original position and the new compressed position. So, since you have no gravitational potential energy on the right hand side of the equation, this infers that h=0 (relative to 'zero' level). So , zero level must be at the end position of the spring compression. Therefore, on the left hand side of equation, potential energy must become

6.2*(32.2)*(25*sin(20)+x*sin(20))
where x = the extra compression of the spring along the slope

This change on the left hand side you have already stated (h = (25+x)*sin(20))

On the right hand side, spring potential energy must become .5*K*(.5+x)^2, because .5 is
the initial compression and x is the extra compression of the spring along the slope.

Oh, and I noticed that in the equation, on the left hand side, you need to square (I think?) the 8 ft/s.

(btw, how do you format equations into neat looking text?)


text:
# Ode periodic solutions

I have a question concerning periodic odes: $y'=y^2f (t)$, where $f$ is a real continous and periodic function with period $T$, with initial condition $y(0)=y_0\gt0$. It is asked to show that there are always $y_0$ such that there is not a global solution and to find those conditions on $f$ such that there are global non-zero periodic solutions. I solved the equation with separation af variables getting $$y=\frac{1} {\frac{1}{y_0}-\int_{0}^t f (s)ds}.$$ And I have no othqer ideas on the first question. As far as the second is concerned I substituted $s+T$ obtaining the same solution, so I guess no more conditions are needed, but I feel I'm wrong. May you help me?

• What is the condition for $y(T)=y_0$? How can you produce a singularity, i.e., a zero denominator at some $t$? – LutzL Feb 24 '17 at 22:02
• Maybe $\int_0^t y_0f (s) ds=0$ giving $f (t)=0$ for a given $t$? But this is not necessary satisfied... – Gigio Feb 24 '17 at 22:11

We introduce the antiderivative $F(t) = \int_0^t f(s)\, ds$ and the following decomposition of the integral: $$F(t) = \int_0^{T\left\lfloor\frac{t}{T}\right\rfloor} f(s)\, ds + \int_{T\left\lfloor\frac{t}{T}\right\rfloor}^t f(s)\, ds = \left\lfloor t/T\right\rfloor\! F(T) + F(t-T\left\lfloor t/T\right\rfloor)) \, .$$ If $F(T)$ is nonzero, then the choice $y_0 = 1/F(T)$ makes the denominator of $y$ vanish at the time $t=T$. Else, $F(T)=0$ and we can find $t^*$ in $[0,T[$ such that $F(t^*)$ is nonzero. The choice $y_0 = 1/F(t^*)$ makes the denominator vanish at the time $t=t^*$. Thus, we can always find $y_0$ such that no global solution exists.
Now, let us consider a $T$-periodic global solution $y$. For $t$ such that $y(t)$ is nonzero, one has $$y(t+T)^{-1} - y(t)^{-1} = -\int_t^{t+T} f(s)\, ds = -F(T) = 0 \, .$$ Furthermore, the denominator in $y$ cannot vanish, i.e. $1/y_0$ cannot belong to the image of $[0,T[$ through $F$. The inverse $1/y_0$ of the initial value is allowed to be strictly larger than $\max_{t\in[0,T[} F(t)$, or strictly smaller than $\min_{t\in[0,T[} F(t)$.


text:
# zbMATH — the first resource for mathematics

Recursiveness, positivity, and truncated moment problems. (English) Zbl 0757.44006
Suppose, there are $$m$$ complex numbers $$\gamma_ 0,\gamma_ 1,\dots,\gamma_ m$$. Let $$K$$ be a subset of $$\mathbb{C}$$. The truncated $$K$$- power moment problem is the question of finding a positive Borel measure $$\mu$$ such that $$\int t^ j d\mu(t)=\gamma_ j$$ ($$0\leq j\leq m$$) and $$\text{supp} \mu\subseteq K$$. The authors consider the cases $$K=\mathbb{R}$$, $$[a,b]$$, $$[0,+\infty)$$ and $$T=\{t\in \mathbb{C}$$: $$| t | =1\}$$. They give a detailed description of necessary and sufficient conditions for solvability of the moment problem. They obtain a lot of classical results and state many new ones.
Reviewer: E.Krätzel (Jena)

##### MSC:
 44A60 Moment problems


text:
# Why there is no decoupling capacitors in analog IC

Here is a CMOS two stage amplifier. As you can see there is no decoupling capacitor at all. Also I don't see decoupling capacitors that are used in CMOS integrated circuits. Could you explain why? Thank you for help.

• Capacitors are very expensive in terms of area, and therefore large capacitors are usually left outside the chip. Feb 1 '16 at 16:39
• Decoupling/bypass capacitors are connected between power supply and ground. They wouldn't necessarily be shown on the amplifier schematic, particularly not on the internal schematic of an IC. Feb 1 '16 at 16:42

Decoupling capacitors are used in digital circuits to suppress the high-frequency noise generated on the supply line (Vcc or Vdd) as a result of the rapid switching inside the chip. The signals that are switching are usually square waves, which generate a lot of harmonics.

These capacitors fulfill dual roles -- they provide a little energy reserve to suppress voltage spikes inside an IC, and they help suppress any voltage spikes on the supply line outisde the chip from getting in.

Analog circuitry, on the other hand, usually doesn't switch as fast as digital IC's do, and even when it does, the signals usually aren't square waves so they don't have as many harmonics. Still, it is recommended to put decoupling IC's on all analog chips like op-amps. They are especially needed for analog devices that have a poor power supply rejection ratio (PSSR) to avoid power supply fluctuations from affecting the output.

In either case, decoupling caps are almost never found inside the IC's; as others have pointed out, they are usually separate components placed next to a chip between the power and ground pins. Values of 100 nf (0.1 µF) and 10 nf (0.01 µF) are often used.

Decoupling caps are required to not only make your circuit behave more reliably, but also to reduce emissions to enable it to pass FCC certification.

• Apparently, the question was related to missing COUPLING capacitors (see my answer and the latest comment from the questioner).
– LvW
Apr 18 '16 at 6:23

As many people could and have pointed out, capacitors are large. If left outside the chip, it makes IC design easier to manage. This means we need them outside the IC. It does not mean, however, that we need a capacitor package on the surface. By keeping them outside the package we have allowed for the layout specialists to get creative.

The layout specialists will sometimes create layers with a given surface area, distance between them, material, etc. in order to create a capacitance between them. You can then use the internal layers as a capacitor. This means that by keeping them on the outside of the IC we can give designers more flexibility. They can choose to place the caps next to the part, a little further away, on the opposite side of the board, as internal layers (whatever gives us better results). This is a good thing in the ever shrinking HDI world.

Very large cap are placed outside of the chip, however, it is usually good practice when you do the IC layout, to use any spare area, and fill it with decoupling cap, sometime the designer will have those cap already in the schematic but not necessarily, this will help with not only the performance of the amp/block but also with other process requirement like metal/poly density. It is also not unusual in RF part, to see the design term specify a minimum decoupling cap to be inserted - as many said this has a cost in term of area, that actually lead to creation of MOM cap which can be layout over circuitry.

I think, the most obvious reason is that the shown circuit (with a diff. amplifier at its input) is intended to work for very low frequencies down to DC. Such a DC amplifier must not contain any coupling capacitors because it must allow DC negative feedback.

• Because, continuously, I try to learn it would be very important (and interestingly) to read, why somebody felt the necessity to downvote this answer. Please, if something is wrong, dont hide your identity and try to improve my knowledge. Dont you think, that - because of the diff. amplifier at a first stage - the whole circuit is prepared for DC feedback?
– LvW
Apr 15 '16 at 9:29
• Looking at the question, it appears to be discussing the power supply decoupling caps, not stage to stage caps.
– W5VO
Apr 15 '16 at 12:48
• OK - I must admit that I have overlooked the prefix "de". I really could not imagine that somebody is surprised to see no power supply decoupling capacitors located on the chip. On the other hand - what is the working principle of capacitors in parallel to emitter resp. source resistors? Coupling or decoupling?
– LvW
Apr 15 '16 at 14:17
• I'll be honest, the term decoupling with capacitors is used inconsistently by a lot of people in different ways. Not sure what circuit you're referring to - in the question, capacitor Cc is a Miller compensation capacitor for stabilizing the frequency response of the amplifier. For a common-emitter/source amplifier with a source degeneration resistor for DC biasing, and a capacitor in parallel to the source resistor, I would probably call it a "DC Bypass" capacitor.
– W5VO
Apr 15 '16 at 15:05
• Unfortunately, the questioner (user 3126592) did not react upon the answers up to now. I would be not surprised if his question was initially related to the missing coupling capacitors between the stages (although he wrote "decoupling").
– LvW
Apr 15 '16 at 15:40


text:
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Calculating with Fractional Indices

# Calculating with Fractional Indices

GCSE(H),

For a fractional index, the numerator is a power term, and the denominator is a root term.

27^frac(2)(3) means square 27 then cube root the answer; or cube root 27 then square the answer. Choose the easiest calculation. In this instance, the cube root of 27 is 3, and 3 squared is 9.

## Examples

1. Simplify sqrt(2) xx root(4)2, and show with a fractional index.

Answer: 2^frac(3)(4)

sqrt(2) xx root(4)2

= 2^frac(1)(2) xx 2^frac(1)(4)

= 2^frac(3)(4)

2. Simplify √5 ÷ 25. Leave the index as a fraction.

Answer: 5^(frac(-3)(2)

sqrt(5) ÷ 25

5^frac(1)(2) ÷ 5^2

5^(frac(1)(2) - 2)

5^-frac(3)(2)


text:
Here I would like to summarize my understanding of Singular Value Decomposition (SVD).

# Matrix multiplication is essentially rotation and stretching

Consider the following multiplication

\begin{align} Ax &= y \label{eq:matmul} \end{align}

e.g.

\begin{align} \begin{bmatrix}2 & 1\\ -1 & 1\end{bmatrix} \begin{bmatrix}1 \\3 \end{bmatrix} = \begin{bmatrix}5 \\2 \end{bmatrix} \end{align}

Thus, a 2D vector ends in another 2D vector, which is essentially a rotation and stretching.

To see which part of $A$ does the rotation and which part of it does the stretching, that’s where SVD comes into play.

Equivalently, we could rewrite Eq. \eqref{eq:matmul} into

\begin{align} Av &= \sigma u \end{align}

where $v$ and $u$ are unit vectors, you could consider both sides are divided by a factor to turn $x$ from Eq. \eqref{eq:matmul} into a unit $v$. $\sigma$ is a scaling factor that plays the stretching.

When considering $n$ orthonormal $v$ vectors, represented as U, the above equation becomes

\begin{align} \underset{m \times n,}{A} \underset{n \times n}{V} &= \underset{m \times n,}{U} \underset{n \times n}{\Sigma} \end{align}

where $\Sigma$ is diagonal. The reason that $n$ $v$ vectors are used is because $V$ cannot be inverted otherwise. If they were not orthonormal, they could always be turned into orthonormal via Gram–Schmidt process.

Then,

\begin{align} \underset{m\times n}{A} &= \underset{m \times n,}{U} \underset{n \times n,}{\Sigma} \underset{n \times n}{V^{-1}} = U \Sigma V^T \end{align}

Since $U$ is not square, this version of SVD is called reduced SVD. There are also full SVD and truncated SVD, see here.

Some experiments done on SVD regarding matrices shapes are recorded here.

# SVD theorem

For any matrix $A \in C^{m \times n}$, it has a singular value decomposition.

• singular values $\{\sigma_i\}$ are uniquely determined, and if $A$ is square, $\{\sigma_i\}$ is distinct.
• $\{u_i\}$ and $\{v_i\}$ are also unique up to a complex sign.

This statement of the theorem is from https://youtu.be/EokL7E6o1AE?t=38m16s.

# SVD and PCA

SVD could be used to solve principal component analysis (PCA).

Suppose input is the matrix $X$, which has to be standardized to have zero mean and unit variance. The principal components of $X$ are also the egigenvectors of the corresponding covariance matrix ($X^TX$).

\begin{align} X X^T = Q \Lambda Q^T \end{align}

In terms of SVD, $X^TX$ can also be written as

\begin{align} X X^T &= (U \Sigma V^T)(V \Sigma U^T) \\ &= U \Sigma^2 U^T \\ \end{align}

Hence, \begin{align} Q &= U \\ \Lambda &= \Sigma^2 \\ \end{align}

Additional reference: https://math.stackexchange.com/questions/3869/what-is-the-intuitive-relationship-between-svd-and-pca, which says that numerically SVD is much more stable than constructing covariance matrix. SVD is one of the most common way conduct PCA.


text:
# Quickstart Guide: GFDL CM2.5 and FLOR Models

References:

Delworth, Thomas L., Anthony Rosati, Whit G Anderson, Alistair Adcroft, Venkatramani Balaji, Rusty Benson, Keith W Dixon, Stephen M Griffies, Hyun-Chul Lee, Ronald C Pacanowski, Gabriel A Vecchi, Andrew T Wittenberg, Fanrong Zeng, and Rong Zhang, April 2012: Simulated climate and climate change in the GFDL CM2.5 high-resolution coupled climate model. Journal of Climate, 25(8), doi:10.1175/JCLI-D-11-00316.1.

Vecchi, Gabriel A., Thomas L Delworth, Rich Gudgel, Sarah B Kapnick, Anthony Rosati, Andrew T Wittenberg, Fanrong Zeng, Whit G Anderson, Venkatramani Balaji, Keith W Dixon, Liwei Jia, Hyeong-Seog Kim, Lakshmi Krishnamurthy, Rym Msadek, William F Stern, Seth Underwood, G Villarini, Xiaosong Yang, and Shaoqing Zhang, November 2014: On the Seasonal Forecasting of Regional Tropical Cyclone Activity. Journal of Climate, 27(21), DOI:10.1175/JCLI-D-14-00158.1.

## 1. Acquire the Source Code and Runscripts

A zipped tar ball containing the code and scripts can be downloaded here. This package contains code, scripts and a few tools. Model input data and sample output exist as separate files.

## 2. Acquire the Input Datasets

Note that the resulting tar files are sizable, approximately 24GB for the CM2.5 data. Extract the files into a location where you have sufficient free space.

## 3. Run the Models

### 3.1. Functionality of the Sample Runscripts

The scripts to compile and run the models can be found in the exp directory. They were developed and tested on the gaea machine at ORNL using the versions of system software that were default at the time of development. Both CM2.5 and FLOR run from the same source code and executable, only the input differs.

The compile script:

• compiles mppnccombine, which combines atmospheric restart files from multiprocessor distributed output into one netcdf file.
• compiles landnccombine, which combines land restart files from multiprocessor distributed output into one netcdf file.
• compiles fregrid, which interpolates data on a cubed sphere grid to a global lat-lon grid.
• compiles and links the source code.

The run script:

• creates a working directory where the model will be run.
• creates or copies the required input data into the working directory.
• runs the model.
• combines distributed ouput and renames the output files using the timestamp.
• executes mppnccombine and landnccombine to combine multiprocessor distributed output and renames the output files using the timestamp.
• executes fregrid to interpolate diagnostic output on the cubed sphere grid to a global lat-lon grid.

Note that all model output and processed model output is left in the working directory. It is not copied to permanent storage.

Also note that the directory paths and file paths are variables. They are initially set to correspond to the directory structure as it exists after extraction from the tar file, but are made variables to accommodate changes to this directory structure.

The directory path most likely to need changing is workdir. workdir is a temporary directory where the model will run. A sizable amount of data will be copied into the work directory, and output from the model is also written to the work directory. workdir must be large enough to accommodate all of this. The input data is approximately 24GB and the model output is potentially much larger.

### 3.2. Portability Issues with the Sample Runscripts

If you encounter a compile error when executing the compile script, first check whether you have correctly customized your mkmf template. The scripts use the mkmf utility, which creates a Makefile to facilitate compilation. The mkmf utility uses a platform-specific template for setting up system and platform dependent parameters. Sample templates for various platforms are provided in the bin directory. You may need to consult your system administrator to set up a compilation template for your platform and ensure the locations for system libraries are defined correctly. For a complete description of mkmf see the mkmf documentation.

### 3.3. layout and io_layout

This discussion of layouts applies only to the atmospheric and land components of the models, not the ocean or ice components. It is a repeat of what is included in GFDL’s public release of AM3.

#### 3.3.1. layout

The horizontal grid of each component model is partitioned among processors according to the setting of the namelist variable “layout”. Each model has a layout variable in its namelist.

Consider a horizontal grid with 30 cells in one direction and 16 in the other. (This does not have to be rectangular longitude by latitude grid, model grids can be considered logically rectangular.) If run on 24 processors, one could set layout=6,4 The grid would be partitioned among processors as shown below. (Each asterisk represents a grid cell)

 +---------+---------+---------+---------+---------+---------+
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|         |         |         |         |         |         |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|  pe=18  |  pe=19  |  pe=20  |  pe=21  |  pe=22  |  pe=23  |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|         |         |         |         |         |         |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
+---------+---------+---------+---------+---------+---------+
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|         |         |         |         |         |         |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|  pe=12  |  pe=13  |  pe=14  |  pe=15  |  pe=16  |  pe=17  |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|         |         |         |         |         |         |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
+---------+---------+---------+---------+---------+---------+
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|         |         |         |         |         |         |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|  pe=6   |  pe=7   |  pe=8   |  pe=9   |  pe=10  |  pe=11  |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|         |         |         |         |         |         |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
+---------+---------+---------+---------+---------+---------+
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|         |         |         |         |         |         |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|  pe=0   |  pe=1   |  pe=2   |  pe=3   |  pe=4   |  pe=5   |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
|         |         |         |         |         |         |
|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|* * * * *|
+---------+---------+---------+---------+---------+---------+

The cubed_sphere atmosphere and land models treat each face of the cubed sphere grid as a separate grid in itself. The example above would then represent one face of the global grid. The total number of cells globally would be $30 \times 16 \times 6 = 2880$ (6 is for each cubed sphere face). The total number of processors used would be $6 \times 24 = 144$

The cubed_sphere atmosphere has one restriction: It requires at least 4 grid cells in each direction, a minimum of 16 grid cells per processor.

Choice of layout has no effect on the model’s solution, but on some platforms the code’s performance can be affected.

#### 3.3.2. io_layout

The I/O efficiency of high resolution models run on a large number of processors can be significantly impacted by the number files written. For this reason, this code allows control over the distributed output of the diagnostic and restart files.

io_layout is a namelist variable that controls the partitioning of multiple processor output among files. Each component model has its own io_layout.

Consider a model running on 24 processors with layout=6,4 as shown above. If io_layout were set to 3,2 the processor output would be aggregated into files as shown below.

 +-------------------+-------------------+-------------------+
|                   |                   |                   |
|                   |                   |                   |
|                   |                   |                   |
|  pe=18     pe=19  |  pe=20     pe=21  |  pe=22     pe=23  |
|                   |                   |                   |
|                   |                   |                   |
|                   |                   |                   |
|      file 3       |      file 4       |      file 5       |
|                   |                   |                   |
|                   |                   |                   |
|                   |                   |                   |
|  pe=12     pe=13  |  pe=14     pe=15  |  pe=16     pe=17  |
|                   |                   |                   |
|                   |                   |                   |
|                   |                   |                   |
+-------------------+-------------------+-------------------+
|                   |                   |                   |
|                   |                   |                   |
|                   |                   |                   |
|  pe=6      pe=7   |  pe=8      pe=9   |  pe=10     pe=11  |
|                   |                   |                   |
|                   |                   |                   |
|                   |                   |                   |
|      file 0       |      file 1       |      file 2       |
|                   |                   |                   |
|                   |                   |                   |
|                   |                   |                   |
|  pe=0      pe=1   |  pe=2      pe=3   |  pe=4      pe=5   |
|                   |                   |                   |
|                   |                   |                   |
|                   |                   |                   |
+-------------------+-------------------+-------------------+

Output from a single processor cannot be divided between files. This means that io_layout must be chosen such that layout(1) and layout(2) are multiples of io_layout(1) and io_layout(2) respectively.

The output file names consist of a base name with a four digit file number appended to it. For the example above the restart files for the ice model would be:

• ice_model.res.nc.0000
• ice_model.res.nc.0001
• ice_model.res.nc.0002
• ice_model.res.nc.0003
• ice_model.res.nc.0004
• ice_model.res.nc.0005

As stated above, the cubed sphere atmosphere and land models treat each face of the global cubed sphere grid as a separate grid. From these models, one would see output files names with both the tile and processor numbers as part of the name. For example:

• atmos_coupled.res.tile1.nc.0000
• atmos_coupled.res.tile1.nc.0001
• atmos_coupled.res.tile2.nc.0000
• atmos_coupled.res.tile2.nc.0001

There would be a total of 30 atmos_coupled.res.* files.

Tools are provided to combine these distributed files into files of data on a single grid. The processor numbers are removed from the file names after combining. Combining of restart files is done in the run script provided, but is not required. The code has the capability of restarting with either combined or distributed restart files.

If io_layout is set to 1,1 then all processors write to a single file and the file number suffix does not appear in the file name.

### 3.4. Restarting and cold-starting

#### 3.4.1. restarting

Restart files are written to a sub-directory, named RESTART, off the working directory. Information about the state of the model at the point of termination is contained in these files. Each component model and/or sub-component may have restart files. To continue a previous integration these files are put in the INPUT directory. They are read at initialization to restore the state of the model as it was at termination of the previous integration.

#### 3.4.2. cold-starting

If a component and/or sub-component does not find its restart files in the INPUT directory then it performs a default initialization, also referred to as a cold-start. The default initialization of each component is required to be compatible with other model components, but otherwise is entirely at the discretion of the developer(s).

The atmospheric and land models typically fill the model fields with constant values for a cold-start. The result is a model state that is very flat and far away from anything scientifically interesting. As a result, a cold-started model needs to be spun-up. The spin-up time can be very long. For the land model it can be on the order of a century or more. For this reason it is recommended that the user cold-start only the atmospheric component, by omitting only atmospheric restart files and including all other restart files.

A few changes to the namelist settings are needed for a cold start. For the intrepid, a namelist file with these changes is included.

### 3.5. Time and calendar

Control of model time and calendar is a common source of confusion. Only a couple facts need to be understood to avoid most of this confusion. The first is how the model time and calendar are set.

When coupler.res does not exist:
current_date and calendar are as specified in coupler_nml and the namelist setting of force_date_from_namelist is ignored.
When coupler.res does exist and force_date_from_namelist=.true.:
current_date and calendar are as specified in coupler_nml.
When coupler.res does exist and force_date_from_namelist=.false.:
current_date and calendar are read from coupler.res and the namelist settings of current_date and calendar are ignored.

The second is the date which appears at the top of the diag_table. This is the model initial time. It is used for two purposes.

• It is used to define a time axis for netcdf model output, the time values are since the initial time.
• It is also used in the time interpolation of certain input data. Because of this, It is recommended that it always be equal to the date that was used for current_date (in coupler_nml) in the initial run of the model and that it not change thereafter. That is, do not change it when restarting the model.

### 3.6. diag_table

The diagnostic output is controlled via the diagnostics table, which is named diag_table.

Documentation on the use of diag_table comes with the release package. After extraction, it can be found in the file src/shared/diag_manager/diag_table.html.

### 3.7. data_table

The data_table includes information about external files that will be read by the data_override code to fill fields of specified data.

### 3.8. field_table

Aside from the model’s required prognostic fields, the models may or may not have any number of additional fields. These optional fields, referred to as tracers, are specified in field_table. For each tracer, the method of advection, convection, source and sink that are to be applied to the tracer is specified in the table. In essence the field_table is a powerful type of namelist.

### 3.9. Changing the Sample Runscripts

#### 3.9.1. Changing the length of the run

By default the scripts are set up to run only eight days. The run length is controlled by the namelist coupler_nml The variables months and days set the run length.

#### 3.9.2. Changing the number of processors

To change the number of processors, change the \$npes variable at the top of the sample runscripts. The processor count must be consistent with the model layouts.

## 4. Known bugs

When compiled with the gnu compiler, version 4.7.0, both models crash with a Segmentation fault at line 897 of mpp_domains_util.inc

## 5. How to get help

Documentation concerning the ocean component of CM2.5 and FLOR can be found here: https://mom-ocean.github.io/docs/userguide/. This guide also provides additional documentation of the field, data and diag tables.

All inquiries regarding this release should be mailed to: GFDL.Climate.Model.Info@noaa.gov


text:
# Integral Fast Reactor

1. Feb 19, 2008

### catseye747

Does anyone know why this project lost its funding? From what I understand it was three years from being completed. The prototype EBR II which had tests conducted to verify the passive safety system were successful and then BAM funding is cut. Was it due to Chernobyl or Three Mile Island. I think I read that these test were performed a couple of weeks before Chernobyl.

Thanks

2. Feb 19, 2008

### theCandyman

Part of the Clinton adminstration's promises were to cut back funding for nuclear related programs. IFR got cut.

3. Feb 21, 2008

### Andrew Mason

There seem to be different views as to why Congress voted to cut funding. "http://www.nrdc.org/nuclear/bush/freprocessing.asp" [Broken] says that Congress was concerned about the proliferation risk:

The Integral Fast Reactor concept envisioned that pyroprocessing spent fuel would take place in a facility adjacent to a reactor and some radioactive transuranium elements would remain mixed with the plutonium, making the otherwise separated plutonium less vulnerable to theft. The 62.5 megawatt-thermal (20 megawatt-electric) Experimental Breeder Reactor-II (EBR-II) used a prototype for testing Integral Fast Reactor fuel. The concept was highly uneconomical, however, and would have represented a significant proliferation risk because non-weapon states could have converted pyroprocessing facilities to produce and separate weapons-grade plutonium. DOE therefore terminated the Integral Fast Reactor program in September 1994, but it kept alive the pyroprocessing program by continuing reprocessing research using Experimental Breeder Reactor-II spent fuel.
"http://www.pbs.org/wgbh/pages/frontline/shows/reaction/interviews/till.html" [Broken] on the other hand, the head of Argonne's reactor development program for the IFR, says that the IFR fuel cycle presented a very low proliferation risk.

Morbius may have something to say on this. I expect that the proliferation risk for the IFR was not well understood by Congress.

In my view, the IFR had great potential. But it was probably ahead of its time, technologically and politically.

AM

Last edited by a moderator: Apr 23, 2017 at 11:00 AM
4. Feb 23, 2008

### Staff: Mentor

Certainly one single plant would be uneconomical because of all the R&D that goes into it.

The argument about proliferation is spurious, because weapon states can develop the technology, and non-weapon states could also if they are able to obtain the technology from countries other than the US.

Gore may have had more to do with undermining support for nuclear energy in the US than Clinton, but Clinton was certainly not supportive of nuclear. Hazel O'Leary was not a good choice for Sec of Energy. In fact, I was unimpressed by many in the Clinton cabinet, particularly those as SecEnergy.

5. Apr 16, 2008

### RobertW

The EBR II project was nearly completed - it cost more to cancel the project than it would have cost to complete it. You can find the entire history of the EBR II by googling the following: S.M. Stacy, Idaho National Laboratory, Proving the Principle This will eventually lead you to about 24 chapters on the history of the Idaho National Laboratory that will include numerous details about EBR II and why it was cancelled. By the way, the EBR II has been totally dismantled, but they continued some of the fuel reprocessing projects.
I have written a book "Total Energy Independence for the United States - A Twelve-Year Plan" extolling the benefits of the integral fast reactor in achieving oil independence and a hydrogen fuel infrastructure for the U.S, and for consuming most of the waste plutonium currently being stored in about 125 locations throughout the U.S. I used some of the information documented by S.M. Stacy in my book.

6. Apr 16, 2008

### vanesch

Staff Emeritus
This has the same smell to it as Super-Phenix...

I don't know much about the IFR, but what I know about it, sounds brilliant. I had a few courses on the pyro-processing techniques that were used there. As such, the argument of proliferation is, as usual, silly, because the knowledge is out there
(this is like Carter being against the PUREX process, while you can read about it in a few books...).

Last edited: Apr 16, 2008
7. Oct 22, 2008

### Captainjf

I am in debate and i was instructed by my teacher to find negative evidence on the IFR reactor. is there anything wrong with the reactor that stands out alot?

8. Oct 22, 2008

### RobertW

Relative to the other types of reactors in current use, IFRs of the EBRII design are the safest reactors in the world at this time. The Russians have had a fast neutron reactor in continuous operation on their power grid since 1981. The world has about 290 reactor-years of experience with fast neutron reactors. See:
http://www.world-nuclear.org/info/inf08.html

The IFR negative that comes to mind first is that the "fuel reprocessing cell" is costly. However, the cost of creating huge water reserviors for cooling light water reactors is also costly. Considering the safety advantage in not having to transport highly radioactive fuels on our highways and railroads, I believe the fuel reprocessing cell is worth its cost.

Another problem with metal-cooled reactors is that the liquid metals, particularly lead, used for cooling may cause problems with the piping used in the reactor. For example, liquid lead can leach some of the metal from the piping. I understand MIT has done research on the leaching problem with highly favorable results. MIT found that chromium and nickel alloys are very resistant to leaching.

I would like to know if you have found anything else WRONG with the IFR.

Last edited: Oct 22, 2008
9. Oct 23, 2008

What about the acutal cost, is it around $10bill for one reactor? more? less? i just need more info. 10. Oct 23, 2008 ### RobertW The best estimate I can find on the cost of an IFR is$1.5 to $2 billion for a one-Gw(e) reactor if the reactors are mass-produced. In my book, I use the scenario of constructing 500 reactors at locations throughout the U.S. where there is an abundant supply of water. My thinking is that the water could be electrolyzed to produce hydrogen and steam used to drive the generators. The cost of the reactor will also vary if the operating fluid is a supercritical gas instead of steam. The use of a supercritical gas as the operating fluid practically eliminates the need for water. Water would be needed only for sanitation purposes and pyroprocessing of spent fuel. I am assuming that you are aware that the IFR can use our reprocessed nuclear waste for fuel. We have on hand enough "fuel" (nuclear waste and processed uranium) for the IFRs to produce all of the energy the U.S. will need for the next 1,000 years. Last edited: Oct 23, 2008 11. Oct 23, 2008 ### Captainjf What i would really like to know is how much a standard IFR (sodium cooling, not mass produced, and still new) would cost. not any new versons, because this is all that the other teams are basically saying. also for a 1,700MW reactor 12. Oct 24, 2008 ### RobertW There is no such thing as a "standard" 1.7GW(t) IFR - one must be designed and built. A 1.7GW(t) -(thermal) IFR would produce about one GW(e) - (electrical) output. Based on the Department of Energy's 10-year old estimate of$985 million to build a one GW(e) IFR reactor, the 1.5 to 2 billion dollar estimate I gave you earlier is approximately correct once the prototype is built, tested, and approved, taking inflation into account. The prototype one GW(e) IFR, estimating again, would cost about $5 to$10 billion to design, construct, test, and approve.

The use of liquid sodium as the coolant in an IFR has inherent dangers. Sodium, when exposed to air will burn; exposure of sodium to water in the presence of oxygen can cause an explosion. The Monju IFR in Japan had such an accident. No one was injured, but the reactor had to be shut down. Liquid lead is the coolant of choice because of its shielding characteristics and higher operating temperature.

If you are debating the disadvantages of the IFR relative to the other types of reactors, you definitely have an uphill battle.

13. Oct 24, 2008

### Captainjf

Thank you for all the information, but what if you look at it in a perspective of IFR against all other alternate energy (solar, wind, biofuels) instead of against other reactors? Does that change anything?

14. Oct 24, 2008

### vanesch

Staff Emeritus
Show me a place with cities and industries and so on where, say, more than 75% of the electricity has been reliably provided by alternatives, for at least a few years.

15. Oct 24, 2008

### RobertW

(Originally Posted by Captainjf
Thank you for all the information, but what if you look at it in a perspective of IFR against all other alternate energy (solar, wind, biofuels) instead of against other reactors? Does that change anything?)

The amount of power that will be required in the U.S. in the future will be immense. To provide the needed power with wind turbines, solar, etc. is unrealistic. It would require 400 2.5 MW wind turbines to equal the power output of one 1GW(e) IFR - assuming that the wind turbines get enough wind to produce their maximum output. One-eighth of the surface of the U.S. would have to be covered with solar cells to meet the nations power needs - and then only when the sun is shining. What makes matters worse is that solar cells, when they are spent, are slightly radioactive - another disposal problem.

A 0.5GW(e) "clean coal" plant produces 125,000 tons of ash and 165,000 tons of sludge (from the stack scrubbers) in one year. The ash and sludge contain arsenic, cadmium, mercury and ... . The fly ash from the stacks contain 100 times more radioactivity than the air near a compliant nuclear reactor. Many times, the sludge is allowed to seep into the ground, contaminating the ground water for miles around. All of this is before we consider the CO2 output.

IFRs are reliable and their output is constant for 30 to 60 years, regardless of the climate, and the cost of mass-produced IFRs per kWh produced will be less than \$1,000. Today, the cheapest source of electricity is nuclear - as low as 2 cents per kWh. The IFR would produce about 1,700 pounds of waste per year and it would be "safe" in 200 to 300 years as opposed to 10,000 to 200,000 years for the light water reactors.

In the future, the cost of energy, not the cost of labor will be the determining factor in which country will dominate on planet Earth. In the long-term, the IFR will produce more energy safer and cheaper than any other technology currently available. It will be another century or two before the fusion reactor is commercially viable. Perhaps, after the fusion reactor will come zero-point energy sources.

How do you like nuclear energy via IFR now?

Last edited: Oct 24, 2008
16. Oct 25, 2008

### Captainjf

Personally, i love the IFR reactor. But in debate, something you love you will have to fight against. (the IFR was actually my starting case, but my teacher pulled me off of it). I just want to know how to fight against it because i will get a very bad grade if i dont find something to use.

17. Oct 25, 2008

### vanesch

Staff Emeritus
Maybe you can use a lot of false information to make up a totally bogus case against the IFR ?

18. Oct 27, 2008

### Andrew Mason

Re: Integral Fast Reactor - a few negatives

In order to cool this reactor you need something that will carry away heat rapidly. The IFR was designed to use liquid sodium, which is a key part of the "inherently safe" design (water at high temperatures must be kept under extreme pressure in order to remain liquid, whereas liquid sodum absorbs heat at extremely high temperatures at atmospheric pressure).

But liquid sodium is highly flammable. So that is a potential problem.

Also, sodium can become radioactive when it absorbs neutrons - 24Na (unlike water which becomes stable deuterium) . This requires a second heat transfer system to circulate in order to withdraw useable heat from the reactor - to power steam turbines. This reduces its efficiency somewhat. That is a potential negative.

The other negative is that it was cancelled by the Clinton administration. That was probably a big mistake. But it means that it carries some political baggage that may make it difficult to get political approval in the future.

AM

19. Oct 27, 2008

### RobertW

According to the International Atomic Energy Admin., (IAEA) sodium used as a coolant for 50 years in a liquid metal cooled fast reactor should be retained for a period of 50 years before it can be used in industry or returned to nature. 24Na becomes stable in about 15 hours - the main problem is caused by 22Na, cobalt60, and cesium137 - they have longer half-lifes. See:
http://www.iaea.org/inisnkm/nkm/aws/fnss/fulltext/1289_7.pdf

20. Oct 27, 2008

### Captainjf

thanks, that helps this a lot!!! I appricate all your help, and if you figure out anything else, it would be very helpful to my team and i.
(Is sodium really the only bad thing about the reactor? That wasnt very smart of clinton...)


text:
## Elementary Algebra

Following order of operations, we first consider exponents. We then create common denominators in order to simplify the fractions. Now, we consider addition and subtraction in the numerator and the denominator. Finally, we turn the fraction into a decimal: $(0.2)^{2}-(0.3)^{3}+(0.4)^{2}$ =$(\frac{2}{10})^{2}-(\frac{3}{10})^{3}+(\frac{4}{10})^{2}$ =$\frac{4}{100}-\frac{27}{1000}+\frac{16}{100}$ =$\frac{4(10)-27(1)+16(10)}{1000}$ =$\frac{40-27+160}{1000}$ =$\frac{173}{1000}$ =$0.173$