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1. Garzo,Vicente Miguel P.
BSCS-CS1-2
ArticlesinChemistry
 POLLUTION PATROL
The "mini-mobile labs"are attachedinthe back of the cars. Airreachesthem
throughtubesthat passthroughone of the vehicle’swindows.Amongthe
pollutantsbeingtrackedare carbonmonoxide,methane,andozone,all of which
can contribute tohealthproblems.The programiscurrentlybeingtestedinthe San
FranciscoBay Areaafter a successful trial inDenverlastyear.Manycitiesalready
track air pollution,butsensorsare oftenfew andfarbetween—plustheydon't
move around.Google hopesitsstreet-by-streetdatacollectionwill helplocal
governmentsfindwaystoaddresspollutantsourcesandimprove local airquality.
The data may alsocontribute toscientificresearchonairpollution.Asdataonair
pollutionbecomesmore widelyavailable,itcouldalsoallow people toavoidzones
withpoorair quality.Forexample,“If you're amotherof an asthmaticchild,you
couldplanyour dayusingthiskindof information,”Google'sKarinTuxen-Bettman
toldNPR.
 MASSIVECONTENDERS
The kilogram, the basic unitof mass inthe metricsystem, needsanupdate.Aspartof theireffortto
redefine the unit,scientistshave createdthe roundestobjectsinthe world.
THE TROUBLE WITH BIG K
Ever since the 1880s, the kilogramhasbeendefinedasthe weightof a certain cylindermade of
platinumandiridium.Thischunkof metal,the international prototype kilogram,iskeptina vaultin
France.It’snicknamedLe Grand K (Frenchfor“Big K”).Othercountrieshave theirownlocal copies.
Unfortunately,measurementsinthe 1990s revealedthatthe massof Le Grand K had changed.Notby
much—aboutthe equivalentof a speckof dust.But a unitwitha changingdefinitionisaproblem.That’s
whyscientistswanttoredefine the kilogram.
FROM CYLINDERS TO NUMBERS
One proposal is to setthe definitionof akilogramusinga formulabasedonAvogadro’snumber,a
constantwitha value of about 6.022 x 1023
. Avogadro’snumber isa countof how manyatoms are ina
certainamountof a substance.Butexistingmeasurementsof Avogadro’snumberaren’tprecise enough
to be usedinthe definitionof aunit.
To get a bettermeasurementof Avogadro’snumber,aninternational teamof scientistshascreatedtwo
near-perfectsiliconspheres.Eachsphere weighsone kilogram(bytoday’sdefinition) andcostmore
than $3 milliontomake.

2. Garzo,Vicente Miguel P.
BSCS-CS1-2
The spheresare the roundestobjectsinthe world—if theywere the size of Earth,the highest
mountaintopwouldbe justafewmeterstall andthe deepestoceanjustafew metersdeep!The
roundnesshelpsthe scientistspreciselycalculate eachsphere’s volume—theamountof space ittakes
up.The researchersare usinglaserstomeasure the diameter,whichallowsthemtocalculate volume.
Andthey’re usingX-raystostudythe spacingof the siliconatoms.Withthatinformation,they’re making
the bestmeasurementsyetof Avogadro’snumber.
HANGING INTHE BALANCE
If the teamcan create a number-baseddefinitionof the kilogram, the unitshouldremainstable.Itwon’t
change no matterwhat happenstothe siliconspheresor Le Grand K. But thisisn’tthe onlyproposal for
a newkilogram.A competingprojectaimstodefine itusingelectrical andmagneticfields.Noone knows
yetwhichdefinitionwill winout.
Andfor anyone outthere hopingtoavoidthe whole problembystickingwithpounds,thinkagain:The
official definitionof the poundis0.45359237 kilograms!
 FUNGUS FIGHTERS
A colonyof leaf-cutterantscannumbermillionsof membersstrong.Because the antsare social
creatures,youmightthinkthatinfectionsoftentake hold,spreadingeasilythroughagroupof leaf-
cutters.But that’snot the case.In fact, the ant issurprisinglyresistanttodisease.Now aninternational
teamof scientistshasdiscoveredhowleaf-cutterswardoff infectionfromapotential enemy,aparasitic
funguscalled Escovopsis:Theirbodiessecrete anacidthat isdeadlytothe fungus,protectingthe ants’
surfacesandbody parts.Large colonieshave groupsof small workerantswithenlargedglandsfor
releasingacid.These creaturesseemtospecialize inlocatingthe fungusandkill itbefore itcantake out
the entire army.Experimentsshowedthatfungusgrowingnearleaf-cuttercolonieshasbecome
somewhatresistanttothe acid.Fortunatelyforthe ants,theirchemical weaponisstill powerfulenough
to protectthem.The insectsseemtocombat resistance byusingthe acidsparingly—onlywhenthe
fungusispresentandonlyinsmall,targeteddoses.
 MUSHROOM MAGIC
The story beginsonthe morningof October3rd 1799. A poor man can be seeninthe gloomydawnlight
gatheringfield mushroomsinLondon’sGreenPark.Whenhe getshome,the mushroomsare cooked
withflour,waterandsaltto provide a morningbrothforhim, hiswife andtheirfourchildren.
A fewhourslaterEverardBrande,a doctor, issummonedtothe householdwherethe familyare
experiencingstrange symptoms.The fatherhasdevelopedvertigoanddisturbedvision;the restof the
familycomplainof poisoningandstomachcrampswiththeirextremitiesbecomingcold.Theirpulses

3. Garzo,Vicente Miguel P.
BSCS-CS1-2
and breathingoscillatebetweenfrighteninghighsandlows.The familyare overwhelmedwiththe fear
of dying– all,thatis, excepteightyearoldEdward,whois“attackedwithfitsof immoderate laughter”.
Nowadayswe can be fairlycertainthatthe strange symptomsexperiencedbythe family200 yearsago
were the resultof accidental consumptionofLibertyCap mushrooms.Or,togive themthe name by
whichtheyare betterknow,“magicmushrooms”or “shrooms”.
These growwidelyinthe UKand continental Europe inthe autumn.Theycarrythe name "LibertyCap"
because of theirresemblancetothe PhrygianCap,commonlyseenasasymbol of liberty.
Magic mushrooms
LibertyCapmushrooms(Psilocybe semilanceata) are partof the large familyof upto 200 species
ofBasidiomycotamushroomthatcontainthe psychedelicdrugpsilocybin.These mushroomsare found
inmany parts of the world,withthe Psilocybe genusbeingthe majortype. Psilocybe have longbeen
associatedwithritual because of theirabilitytochange humanperception –the “psychedelic”effect.
Evidence hasbeenfoundinAlgeria,MexicoandSpainfortheiruse inreligiousceremonies.The Aztecs
calledthemteonanacatl (divinemushroom)andthe mushroomswere reportedlyservedatthe
coronationof MoctezumaII in 1502. Use of Psilocybe bythe Aztecswassuppressedfollowingthe
Spanishconquest,buttheycontinuedtobe usedcovertlybynative Indiansinthispartof America.
Little wasknownaboutthese ceremoniesinthe USand Europe until husbandandwife teamGordon
and ValentinaWassontravelledto Mexicointhe 1950s. Theiraim wasto understandthe culture
associatedwiththe “divine mushroom”andtheymade several visitstoMexicoatthat time.In1955,
Gordon Wassonwasone of the firstwesternerstoparticipate inanindigenousmushroomceremony.
Wassonwrote an article for the popularmagazine “Life”in1957, describingthe mushroomceremony
and the sensationshe experienced.The Frenchmycologist,RogerHeim, accompaniedthe Wassonson
one visitandHeimidentifiedthe mushroomsas Psilocybe mexicana.
The nextstepwas to identifythe active chemical inthe mushrooms,sosamplesweregiventoAlbert
Hofmannat Sandozin Basel.Hofmannwasalreadywell knownasthe chemistwhohadfirstsynthesised
the relatedpsychedelicdrugLSD in1938, and wholaterinadvertentlyexperiencedthe effectsof the
drug himself.Hofmannmade extractsof the Psilocybe andanalysedthe constituentsfortheir
psychological effects,oftentestingthe extractsonhimself.He showedthatthere were twoprincipal
active compoundsinthe mushrooms,psilocybinandpsilocin;once ingested,psilocybinisrapidly
convertedtopsilocin.
The effectsof psilocybinandLSD
So whatare the effectsof psilocybinandpsilocinonhumans?Psilocybinhaseffectsrathersimilartothe
twoother principal psychedelicdrugs,mescalineandLSD,althoughthere are differencesindetail andin
potency.Sol Snyder,inhisbook Drugsand the Brain, describeshow he tookLSD to documentand
understanditseffects.Thisisanexcellentdescriptionfromarespectedscientist;he reportschangesin
sensoryperception,especiallyvisual effects.Objectsmayseemdistorted,change colourorevenmove.

4. Garzo,Vicente Miguel P.
BSCS-CS1-2
Confusionbetweensensorymodalities(synaesthesia) mayalsooccur.Sense of time andspace are
alteredbutitis the effectonthe sense of self thatisparticularlystriking.“Boundariesbetweenself and
non-self evaporate,givingrise toaserene sense of beingatone withthe universe.”He goesonto
speculate:“The almostpredictable transcendence of egoboundariesbroughtonbythese drugshas
causedscientiststoconsiderthatthere mightbe a neural basisforthe ego.”Othersreportheightened
awareness,super-realityandmystical experiencesaftertakingthe drug.Manypeople have enjoyedthe
effectsproducedbythese drugs,whichsometimesofferinsightsnotavailable innormal life.Forothers
it isan unpleasantexperience andaminorityhave injured orkilledthemselvesasaresultof
disorientationcausedbychangedperceptionorlossof self.The experience maydependonthe state of
the individual andtheirenvironmentwhentheytake the drug(“setandsetting”).More recentlyafive-
componentscale hasbeendevisedtoprovide asemi-quantitative measure of the effectsof these drugs.
Mechanismsof actionof psilocybinandLSD
So,how are these curiouseffectsonhumanconsciousnessachievedbythese drugs?Inthe case of
psilocybinandLSD,itis thoughtthatthe drugshijacksome of the normal processesinthe brain.Brain
functiondependsonthe releaseof chemicalstermedneurotransmitters.These are detectedbytheir
bindingtospecialisedproteinscalledreceptors.One neurotransmitterthatis importantforregulatinga
hostof functionsinthe brainandelsewhereisserotonin.Thisneurotransmitterregulatesbehaviour,
mood,sleep,appetite andbloodflow.PsilocybinandLSDbothbindto and activate receptorsfor
serotoninthatare presentthroughoutthe nervoussystem,soitisnot surprisingthattheyhave such
broad impactsonbeaviourandfunction.
To probe these effectsmore deeply,scientistshave begunbrainscanningindividualsusingthe agent,
but sofar the resultsare unclear.One studyfoundbrainactivation whenpsilocybinwasadministeredto
humanvolunteers,whereasanotherstudyreportedreducedactivity,sofurtherworkisrequired.
 MAKINGMETALS STRONGER
For thousandsof yearsmetallurgistshave beenmixingmetalstochange theircharacteristics, oftenwith
world-alteringconsequences.Andalthoughthe materialsscientistsof todayhave largelyswappeda
hammerfor some of the most expensiveandadvancedscientificequipmentmoneycanbuy,the quest
for materialswithsuperiorqualitiescontinues.
Take,for example,the nickel-basedsuperalloysusedextensivelyinthe hottestpartsof the gas turbine
enginesthatpowerpassengerjets.Amongmanufacturersthere isanincreasingdesire tooperate the
enginesathighertemperaturesandundergreaterstresses,meaningthe materialsinsidethemalsohave
to withstandmuchharsherconditions.Why?Because runningagas turbine engine fasterandhotter
meansitcan be more fuel-efficient,keepingdownthe costof a plane ticketandmakingthe aircraft
more environmentallyfriendly.

5. Garzo,Vicente Miguel P.
BSCS-CS1-2
The aims soundsimple,butachievingthemmeansmetallurgistsneedtocome upwithnew materials
capable of meetingthe challenge.One waytodothisis withcomputermodelling,whichallowsmore
efficientandcosteffectivedevelopmentbyemployingamixture of quantitativemathematical
techniquesoverarange of length-scalestooptimise amaterial'sperformance (figure1).
At a microscopicscale,amaterial can be seento be made up of many tinycrystals,whichexhibit
differentatomicarrangementsanddifferentcompositionsreferredtoasthe microstructure.The
physical propertiesdepend,inturn,uponthe interactionsbetweenandwithinthesecrystals,andthe
nature of these interactionscanbe correlatedtothe chemical compositionandtothe arrangementof
atoms.
So,to designan improvedsuperalloy,the compositionandmicrostructure needtobe optimisedto
provide amaterial withanincreasedtemperaturecapability.Butatthishightemperature,the material
mustalso have exceptional mechanical propertiesandexcellentenvironmental resistance toensure
operational longevity.
To designa newsuperalloy,achemical compositionmustfirstbe chosen.Ratherlikeanartistspoiltfor
choice by a massive mixture of colourswithwhichtopaint,a metallurgistmustselectthe rightchemical
elements - andinthe rightproportions - to come up withjustthe rightmetaphorical colour
combination.Foranyalloythere are upto 20 potential elementsthatcouldbe used,meaningthatthere
are literallytrillionsof potentialcompositionstopickfrom.We can considerthisarrayof optionsasa
huge “compositional space”,containingeverypossiblecombination.
So howisthe ideal recipe determined?Todothis,we couldadopt a manual method,whereby
compositionsof possible meritare identifiedusingthe proceedsof previousresearchcoupledwitha
metallurgist’sexperience.Butthissortof manual approach isdemanding,verytime consumingand
therefore limitedintermsof whatitcan achieve.Instead,amore powerful alternativeistouse a
computerto evaluate vastarraysof experimental datawhichcanthenbe combinedwithappropriate
materialsmodelling.Computer-basedmethodslike thisalsomeanthatthe previouslyun-investigated
cornersof compositionalspace canbe probed.
To do so,a choice isfirstmade regardingwhich"phases"are desirableinthe material andthen
elementswhichfavourthe formationof anyotherphase are eliminated.A phase isdefinedas a
structure (an example isshowninthe belowfigure) thatisstable fora givencompositionoverarange of
temperaturesandpressures.Thisisthe jobof specialistsoftwarethatcan calculate the phasesthatwill
formwhendifferentmixturesare made.Thisenablesametallurgisttoidentifythose compositionsthat
will give adesiredcombinationof phases.
The mechanical propertiesof eachphase,orthe whole microstructure,canthenbe predictedusing
neural networkmodelling,whichisastatistical technique basedpartlyonexperimental datafrom
similarmaterialstestedpreviously.
However,superalloysusuallydisplayverycomplex behaviours,soit'snotpossible tomodel all aspects
of theirattributesduringthe initial development,especiallywhenthere islimitedexperimental data.

6. Garzo,Vicente Miguel P.
BSCS-CS1-2
Therefore,duringthe initial stages,assumptionsandsimplificationshave tobe made basedonthe
particularalloysystemsbeingconsidered.Thisincludesevaluatingdifferentphasesseparatelyaswell as
assumingthe combinationof optimal phaseswill leadtothe productionof anoptimal alloy.Withthisin
mind,it'susuallybettertoeliminate compositionsthatclearlydonotmeetthe desireddesign
specificationbecause thisnarrowsthe compositional space downtoa few regionsthatare small enough
to be evaluatedexperimentally.
Next,once some experimental resultshave beengathered,microstructuralmodellingcanbe carried
out.This iscritical because,evenforfully-developedalloys,adjustingcertainaspectsof the
manufacturingprocesscandramaticallyimprove the propertiesof amaterial.And,withthe adventof
advancedmaterialsmodellingtoolswhichallow the materialbehaviourtobe accuratelypredicted,this
has become increasinglycommon.Also,advancesinprocessingtechniques,suchasthe abilityto
bespoke-tailorthe microstructure withindifferentregionsof amaterial tomeetdifferingchemical or
mechanical demands,have beenmade possibledue tocomputational models.
Nowhere isthismore importantthanina jetengine,where aturbine blade hastosurvive inagas
streamapproaching1500°C. At thishightemperature,the lifeexpectancyof componentsislimitedby
slow,time-dependentplasticdeformationof the material.Aseachblade withinthe engine rotates,the
force feltbythe root of the blade isequal tothe weightof afamilycar; and at the highoperating
temperature,thiscausesthe material todeformplastically.Castingthe blade fromasingle crystal,
however,rendersitmuchmore resistanttothisprocess.
Nevertheless,asolidificationprocessthatallowsasingle crystal tobe grownis nottrivial to achieve.The
solidificationprocessis"dendritic",resemblingabranch-type structure similartothe shapesseenin
snowflakesorfrost. Andonce the material isfullysolidified,the historyof thisdendriticsolidification
remainsimprintedwithinthe material,withvariationsincompositionobservedinnumerouslocations.
Thismeansthat, before thismaterial cangointoservice,the compositionmustbe made consistent
throughout.Toachieve this,the material isheatedinafurnace fora numberof hoursat a temperature
highenoughforthe elementstodiffuse quickly.This"ironsout"the fluctuationsinthe composition
throughoutthe material,makingitmuchmore homogeneous.
Observingandoptimisingthisprocessusingmicroscopycanbe expensive andtime consuming.Soin
recentyearsit hasbeenaidedsignificantlybyacomputational tool knownasphase fieldmodelling.By
understandinghowamaterial solidifies,aswell ashow rapidlyeachof the elementsinthe alloycan
move bydiffusion,the heattreatmentprocesscanbe optimisedandmuchbetterunderstood.
In the case of a turbine disc,whichisa large and heavycomponentoftenweighingupto80 kg or more,
whenthisspinsinside anengineatratesof upto 10,000 rpm the kineticenergyishuge.Thismeansthat
the consequencesof a“burstdisc” couldbe catastrophic,so theyare designednevertofail.Butinorder
to be able to deliverthissortof certainty,it'scritical tounderstandthe behaviourandlimitationsof the
material.Andasa material isexposedtoelevatedtemperatureswhilstinservice,itsmicrostructure
evolves,givingrise toagradual change in the material properties.

7. Garzo,Vicente Miguel P.
BSCS-CS1-2
Therefore,tounderstandthe full behaviourof thiscomponent,itisnecessarytounderstandthe
material overa range of length-scales,asshowninthe figure below.By observingasectionof turbine
discunderan electronmicroscope itispossibletosee individualcrystals,orgrains.Increasingthe
magnificationfurtherallowsyoutosee fine precipitates.These precipitatesare tailoredtobe aspecific
shape and size,andare hugelyimportanttothe tremendousstrengthof the material.Zoomingintothe
material evenfartherwouldallowustoreveal the individualatoms.
Overall,it’sbyunderstandingthe relationshipbetweenthese length-scales,helpedbycomputational
tools,the turbine bladesanddiscsof tomorrow will continuetoconveypeoplesafely,butevenmore
economicallyandinamore environmentally-friendlyfashion...

8. Garzo,Vicente Miguel P.
BSCS-CS1-2
4th Generation of programming languages
Fourth generation languages are also known as very high level languages. They are non-procedural languages, so
named because they allow programmers and users to specify what the computer is supposed to do without having to
specify how the computer is supposed to do it. Consequently, fourth generation languages need approximately one
tenth the number of statements that a high level languages needs to achieve the same results. Because they are so
much easier to use than third generation languages, fourth generation languages allow users , or non-computer
professionals, to develop software.
Objectives of fourth generation languages
 Increasing the speed of developing programs.
 Minimizing user effort to obtain information from computer.
 Decreasing the skill level required of users so that they can concentrate on the application rather than the
intricacies of coding, and thus solve their own problems without the aid of a professional programmer.
 Minimizing maintenance by reducing errors and making programs that are easy to change.
Depending on the language, the sophistication of fourth generation languages varies widely. These languages are
usually used in conjunction with a database and its data dictionary.
Five basic types of language tools fall into the fourth generation language category.
1. Query languages
2. Report generators.
3. Applications generators.
4. Decision support systems and financial planning languages.
5. Some microcomputer application software.
Query languages
Query languages allowthe user to ask questions about,or retrieve information from database files by forming requests
in normal human language statements(such as English).The difference between the definitions for query language and
for database management systems software is so slight that most people consider the definitions to be the same.Query
languages do have a specific grammarvocabulary, and syntax that must be mastered, but this is usually a simple task
for both users and programmers.

9. Garzo,Vicente Miguel P.
BSCS-CS1-2
Report generators
Report generators are similar to query languagesin that they allow users to ask questions from a database and retrieve
information from it for a report (the output); however, in case of a report generator, the user is unable to alter the
contents of the database file. And with a report generator,the user has much greater control over what the output will
look like. The user of a report generator can specify that the software automatically determine how the output should
look or can create his or her own customized output reports using special report generator command instr uctions.
Application generators
Application generators allow the user to reduce the time it takes to design an entire software application that accepts
input, ensures data has been input accurately, performs complex calculations and processing logic, and o utputs
information in the form of reports. The user must key into computer-useable form the specification for what the
program is supposed to do. The resulting file is input to the applications generator, which determine how to perform
the tasks and which then produces the necessary instructions for the software program.
Decision support systems and financial planning languages combine special interactive computer programs and some
special hardware to allow high level managers to bring data and information together from different sources and
manipulate it in new ways.
Some microcomputer applications software can also be used to create specialized applications – in other words, to
create new software.Microcomputer software packages that fall into this category include many spreadsheet programs
(such as Lotus 1-2-3), database managers (Such as dBase IV), and integrated packages (such as Symphony).