Showing posts with label study. Show all posts
Showing posts with label study. Show all posts

Sunday, November 20, 2011

Camping Hutan Lipur Ulu Bendul


Salam.. gua semalam baru pulang dari camping kat pilah. dari pada sabtu pagi da bla ke tempat kejadian. ni adalah camping ke-2 gua as a person what-so-called facilitator. generally, camping kali ni banyak bagi gua lesson dan experience baru.

before ni jadi biro disiplin, nak kata susah x susah, senang x senang. masing2 ade kelebihan masing2. dalam biro disiplin, gua x boley mesra sangat dengan trainees, nak gurau2 dengan member2 pon x expose. yes its like a hypocrite, but that was the job. gua kena laksanakan dengan berhemah dan berkesan.

sekarang biro aktiviti. x yah lagi da nak cover2 garang ke ape. walaupun bukan menjadi 100% diri sendiri, tp at least gua x payah menahan diri dari melakukan sebarang perkara. yang beratnya pasal biro ni, otak kena kreatif. even before the camp. semua aktiviti kne dirancang dengan baik dan diterangkan dengan jelas supaya x da salah paham dan berjalan lancar. setiap gap even 5 min kalu trainees boring and x da apa nak buat dan dorg da start buat hal pelik, gua kne buat sesuatu. create la apa2 game supaya trainees x bosan atau kurang bosan.

camping kali ni kekurangan aktiviti. sebab 1st camping ni cume 1 malam shj. 2 hari pulak tu. memang extremely lack of time. dan gua amat tidak menyukainya. sebab banyak aktiviti gua planned kne cut sebab kekangan masa. sedih but boleh diterima. 

pengajaran yang rare gua dapat kali ni adalah

1st. kalau bende nak jadi, ko x dapat ngelak.
2nd. tetap kne react cool, even in panicking moment.
3rd. solve problem in engineering ways
4th kne bantu semua orang, sebab semua tu akan memantul atas diri sendiri.
5th. jangan pass kerja kat orang lain. even dipercayai, u'll not know whats gonna happen
6th. expect the unexpected (ni yang paling ketara)
7th. kebersihan diri tetap dijaga walau berlari sana sini.


stakat ni, tu jelah yang sempat pikiaQ. semoga camping akan datang lebih baik dari kali ni. next camping gua akan bukak balik post ni untuk references. so now gua boley continue focussing on study even next event would be PERKAD (marching and show).

gud luck and thank you!

Tuesday, June 21, 2011

Jenis Blog macam mana yang KRLBrands follow

hey fellas! 


da makan? bwat pe tu? sorang je ke?


(jawab la pliz.....)


ha.. sambil2 blogging baca entry2 pasal hackers, eclipse, shawl, makanan sedap, orang putus cinta, bagai, ni aq nak cite pasal bg cemane yang aq follow..


utk pengetahuan korang, memang aq de 2 blog x termasuk website yg x siap g.. dan blog itu adalah


1. http://kaprileader.blogspot.com/


2. http://krlbrands.blogspot.com/


ok2, aq cite pasal beze 2 blog ni memandangkan aq x femes macam joegrimjoe, ben ashaari, haniszalikha, dll.. (yg x sebut tu kire femes gak, cume aq je x tau)


blog yg first tu adalah blog pertama aq dalam dunia maya ni... asalnya memang x bermatlamat.. bajet macam nak bwat diari konon.. geli je aq dgr. lepas tu aq banyak bwat macam bende2 grafik  cap ayam, sampah, komen2 pasal orang2 sekeliling, tutor2 yang bukan2, dll.. so x lame lepas tu, x la lame sangat, dalam setahun gak.. aq rase cam serabut nak kne carik balik post2 aq yg berkaitan dgn topik2 tertentu... memandangkan aq de minat yg sedalam 2.5meter kepada graphic design, aq mendecide dan memutuskan untuk memisahkan 2 agenda yang berlainan bapa kepada blog yang berasingan.. maka lepas tu terhasillah 2 blog yg aq handle. wah.. da macam sejarah gak aq karang ni. lepas ni boley la tag *history lepas siap.. klw korang cek sekarang gak kat bawah tu aq letak ke x, aq bg singget.. hahha


dah cukup pasal asal usul 2 blog ni. tu je... ada apa soklan, tanye kat komen. I'Allah aq jawab sejujur hati yang suci.


so, nak tau ape blog yang aq follow?? ha.... jeng3.... *drum roll...



bbbrrrr
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r
r
r
r
r
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r
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r
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DOOM!




ciri2 nya seperti berikut:


x semestinya blog awek cantek


x semestinya mamat ensem


x semestinya blog femes


x semestinya pasal bola


x semestinya da ade ramai followers


x semestinya da follow salah satu blog aq


tapi....


blog yang bertemplate smart


blog yang simple


blog yang ringan


blog yang banyak menceritakan pasal tutorial2 adobe illustrator dan photoshop


blog yang selalu menceritakan prinsip2 hidop yang aq rase macam... (eh, betol jugak!)


blog yang selalu letak gamba2 vintage, typography, rare dan ade wow factor


blog yang ade unsur2 humor


dan blog yang mane aq suke. hehe (play safe)

Thursday, January 13, 2011

ECO FRIENDLY : Nokia

This right here is a cellular phone that will last you five years. After that, it’s just a twist and about a minute of dissembling and you’ve got an 85% recyclable stack of materials on your hands. Kind of nice, yes? Why is it all green, you ask? So that the plastic can be melted down and re-molded without any discoloration! Super neat.
This lovely design was made by James Barber in hopes of creating a new, more conscious market for cell phones. He did some fabulous research that pointed toward the energy used to make and the energy used BY a cellphone in it’s whole life. Can you guess which was more?
For a cellphone used for 2 years, the energy used to create the phone is “roughly 3 times larger” than the energy used by the phone in it’s lifetime!
James Barber’s trying to push those amounts of energy closer to equal. To do that, he’s created this extremely rough and tough phone with, yes!, easily replaceable parts, nice, pretty design, and horayy! 85% recyclable parts! I dig it. Or rather, since it wont be in a land-fill with all the other cellphones, I USE it

nokia5yearphone01
do i look like a toys??
nokia5yearphone02
P / S : Underage not allowed to play this!!
nokia5yearphone03
2 year is enough for a luxurious gadget.
nokia5yearphone05

Nokia 5 Year Phone by James Barber

Sunday, November 21, 2010

Patotnye blogger kne tau ni sebelom start blogging

1. The domain name matters

When I started blogging I didn’t pay much attention to the domains of my blogs. As a result I ended up with some long and boring domains (e.g., FutureTechWeb.com, which was my first tech blog). This is a big mistake because the domain is one of the few factors you won’t be able to change.
The rule of thumb I use these days is to look for domains with two words, branding potential and a .com extension. If I wanted to start a soccer blog, for instance, I would consider domains such as SoccerHub.com, SuperSoccer.com and so on. Most of the times I am also willing to spend some money on the domain (e.g., $200-$500), because finding available ones that fit the above requirements is tough.

2. Quality is more important than quantity

As you can guess by the name of this blog, I have always been a big fan of quantity when it comes to content creation. Over the years, however, my opinion has changed a bit.
I still believe that you need to update your blog regularly if you want it to be come popular, but quality should be your first priority. If you only have two hours to spend writing content every week, for example, I would recommend you to spend all the time writing a single, high quality post, instead of writing four small posts to be published on different days.

3. It is about the readers, and not about yourself

If you are blogging as a hobby, then writing about whatever you feel like is fine. If you are trying to build a popular blog and to eventually make money with it, however, you need to be more conscious about the type of content you’ll publish.
More specifically you need to understand that your content should be appealing and interesting to your readers above all, and not to yourself. It’s about them, and not about you.

4. Social media can be a waste of time, too

Social media certainly became a buzz word over the past years, and people seem to think that they need to have a presence and be active on every single social media site out there. I joined the bandwagon for a while, but then realized I was just wasting my time.
I am not saying social media is useless, but that you need to have the right approach to it, else you’ll just waste your time. For instance, instead of joining every single social network out there join one or two at most, where you think your target readers/customers hang out, and where you think you’ll be able to add value and build real relationships.

5. The Pareto principle applies to anything, blogging included

I have a degree in Economics, so I learned about the Pareto principle years ago. It basically states that for many events and things in life, 80% of the effects come from 20% of the causes. For example, 80% of the land in the world is owned by 20% of the people, and 80% of the revenues on most companies come from 20% of the customers.
After some years I realized that the Pareto principle also applies to blogging. This means that 80% of your results (e.g., traffic or revenue gains) will come from 20% of your blogging activities. What are these activities? Writing quality content and promoting that content. If you focus on these, the rest will come naturally.

6. You need a community around your blog

Apart from writing quality content and promoting that content, there is one more activity that is very important for your blog, and that is community building. It’s important because without a community your blog will not be a blog, but rather a website with some articles.
Your community will enrich your content (through comments and email feedback), keep you motivated, help to promote your blog by spreading the word and so on.
Practically speaking this means that you should engage your readers with your content (e.g., by using polls, surveys, asking questions and so on), and that you should interact with them as often as possible (e.g., via comments, email, Twitter and so on).

7. Having an email list is essential

When I started, around 5 years ago, I didn’t know what email marketing was. After two years or so I started joining the email list of other marketers, but until then I had not considered building my own.
It was a big mistake.
A responsive email list is one of the most valuable assets you can have. And mind you that you won’t be using it to spam people, but rather to deliver quality content that will solidify your relationship with your subscribers.

8. Giving away free stuff works like a charm

Over the years I have tried many types of promotions, from interviews to viral videos and linkbaits. One technique always seemed to work, though, and it was giving away free stuff.
I have given away WordPress themes, ebooks, plugins, and more recently my entire Internet marketing training program, and the results I got always exceeded my expectations. If I knew this back in the day I would have used it more often.

9. You need to think about the business model

If you want to make money with your blog, you need to start thinking about your business model right away. That is, you need to have an idea or a plan regarding how you’ll produce value, and how you are going to get paid for that.
Having this clear in your mind will help you craft your content, target the right readers, design your blog around your goals and so on.

10. Selling ads is not the best business model

When people start blogging they believe that the best, if not the only way to make money with it is by selling ads. This is not true.
Selling ads might be the easiest way to make money with a blog, but it’s definitely not the most profitable one.
On most niches selling your own product will be the most profitable model you can have, followed by selling other people’s products (i.e., affiliate marketing), so make sure to consider these at least.

11. Shared hosting sucks

When I started my first blogs I obviously went with a shared hosting plan, and since I couldn’t compare it with anything else I thought it was a decent option.
A couple of years later I moved to a dedicated server, and only then I realized how bad shared hosting plans are. The slow loading speeds, the downtimes, the security holes created by other users on your server….
I know we all must start on shared hosting, but as soon as your blog start making some money (e.g., $300 per month or so), consider investing half of that into a dedicated server.

12. Checking your stats daily is pointless

When you build your first website or blog you start checking your stats at least daily (some people go further and check them hourly….). Every new visitor is a joy, and a sign that you are doing something right.
The problem with this is that you are wasting time. Every minute you spending checking your stats is one fewer minute you have to work on actually get more visitors. On top of that daily fluctuations might give you the wrong idea of what is going on.
My advice would be to check your stats monthly.

13. It takes persistence

Everything happens really fast on the Internet, and when you start building your first websites you figure that they will sky rocket (both in terms of traffic and revenues) within a couple of months.
The reality is quite the opposite. While it’s possible, very few websites become popular or profitable before one or two years. If you want to play the game, therefore, come with the right expectations, else you’ll get frustrated and quit too soon.

14. Choosing the right niche is important

Choosing the right niche is critical if you want your blog to become popular and profitable. Sure, you should follow your passion (as you probably heard around…), but you should also make sure your niche is big enough to generate the kind of revenues you are aiming for.
Also remember that some niches will always be more profitable than others, regardless of their sizes. That is because people inside those niches actually buy stuff, so money circulates more freely.

15. Learning the technical part helps a lot

The Internet technology has advanced so much that today anyone can build a blog or website in 5 minutes, with no technical knowledge whatsoever. As long as you know how to read, you are good to go.
This is certainly a positive thing, as it democratizes the access to information and to publishing.
If you want to make a living online, however, it would be a good idea to spend some time learning the technical part. Start with HTML/CSS, and if you have time try learning JavaScript, PHP and MySQL.

Tuesday, November 2, 2010

Ade bigfoot lah! btol......


btol an ade bigfott.. da cakap da.. x tpu pny.. nampak tapak kaki 2?? sebelah je die pijak kt blog ni.. cemane ntah die jalan.. merangkak x mungkin.. lari apetah lagi! die men teng2! lalala~~ ape yg menarik sgt tapak kaki die ni???

haha.. die ni bukan blogger tegar yg da memiliki 1000+follower dan bukan yg slalu terjerit kat blog orang.. die adalah minah asing yg tinggal luar dari wilayah asia... nme die adalah...
jeng3.....
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StephanieC...


tgk la die cakap ape.. (suke post ni).. dah tu?? ape masalahnye?? ramai je lagi yg suke blog ni!! (poyo bongkak cam haram) x de r.. aq suke part yg die cakap da couple ke married x tw tp da 6 tahun!!! wow!! dgn engineer plak an.. (bajet gempak je).
ternampak je da 6 thun, tros2 aq egt yg aq da couple selama 6 thun jugak secare x langsung dgn si gadis sweet dr N9.. heheh (rahsie ok!) lalal~~  cpat x cpat plak an mase blalu pergi... minom2 dlu ke ape yg patot.. ni x.. men chow je.. geram dgn mase ni.. (ngarot)

dah2.. kte kembali kepada pengetahuan am tentang penjagaan sendi tangan..
perasan x mase kt skola ke CC mne2, mouse (tikus comel) die letak mane?? haha...

yg sepatutnye, natang tu x bley diletakkan atas dari paras dada dan rendah dari pinggang.. x kesah la ape pose pon korg on9.. kecuali kalaw meniarap..( semua sama paras).. cara korg pegang tikus tu sebenarnya, ade care die.. iaitu.... tgk pic bawah ni.


skang sape yg slalu on9 dgn care yg weirdo, (pelik) amalkan la pemakanan yg sihat kerana penghadaman anda mudah dicerna..

ok.. stakat ni jelah. nk study balik.. 
tata~~~

Saturday, October 30, 2010

Bahagi masa antara study, dan On9.... (cam best je)

HI!! 

mggu depan aq de paper calculus.. otak bley naek gler klw study lelame.. klw aq la..
korg yg pandai2 ni rilek sudeyh... sambil2 aq on9 mase study, ataupun study mase on9, aq tergoogle lah sume note2 .pdf ygf stakat ni da 9 file yg da download.. sume 2 campor dr chapter awal sampai mampos (habis la mknenye..)

bile penat study tu an... (an3X) sebenarnye aq boring atau tension.. bukanlah penat macam ko berlari rentas desa permai kg. medan.... tp... tu lah! aq da ckp td an.. (an3x)..

so, ape yg aq bwat adalah, just open mne2 tutorial (yg ni bukan calculus) adobe Ps atau Ai mne2 version (CSX).. korg just buffer... klik pause. bia je loading merah tu jalan tkedek2 sampai mampos (habis la tu)..tu pn klw tenet (teeeetneneneeeet... bnyi trumpet) korg lmbat mcm wifi aq ni ha...
dah loading ape sume bagai, tinggai je... ko troskan BW (jalan dalam halaman rumah En blogger) selama beberapa minit klaw study lebih sejam...

then, stuby blk..
eh! kertas graph pn bley dwnload??
(abes cite utk figure dibawah..)


nampak x tab yg aq bukak tu?? aq puas hati gler tgk.. sampai icon je yg nampak..
agak2 masenyer da sampai, kte play sume video2 tu!!! lalalalallaa
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agak2 da abes, klw mane rse best utk dishare, bubohla dkt page KRL di facebook.. (link)
KRL x marah pny klw share bende2 ni... siryes.. x tipu pny lah!!


Monday, October 25, 2010

Paper + Illustrator = Papetrator

Berakhirlah paper pertama yg telah selesai djawab...
komen pasal soalan?? no komen. tp pic .gif ni telah aq rembat dari mane2 web yg aq sempat explore sepanjang aq study subjek ni.. totally berkenaan enjin. yes mmg aq mnat kete tp x mampu bkerete. tp aq rilek... tenang sudeyh.. x perlu rush kot.

sebenarnya, petang semalam aq bersiar2 keliling Shah Alam teman houseMate (photographer) outing (term bg photo2grapher yg kuar semata2 take the best shot). so, dictu aq dapat la sket tech2 camera zaman sekarang... aq tw light trail, reflection, awan yg terbaek, exposure, dll. style sebenarny jd mereka ni. kenapa aq x minat?? sebab kos sangat tinggi baek intro sampai maintainance. tp klw pandai cari duet, x de hal lah..

minat aq sebenarnya lebih tertumpu pada graphic design. sebab bg aq creativiti ni datang dari satu canvas putih atau blank.. ape yg kite akan bwat utk canvas tu adalah ape yg sempat ko imaginekan... tapi mestilah dibantu dengan software2 yg membantu.. tu lah datang nye 'design'.. 

lepas paper aq nk try beberapa image Ai yg aq download minggu ni.. sangat mengagumkan..  Adobe illustrator generally mggunakan vector ( yang x akan pecah bile di expandkan). so, create lah pape shape yg rare2. mesti kemas dan sharp. klw nak start dr 0, mmg illustrator adalah software yg tepat. hmm... sekarang ade sape2 yg bley tolong bwat free tutor Ai utk aq?? lalalla.....





serba sedikit gamba yg aq download dan edit. mereka ni merupakan ilham2 aq ble mase aq memerlukannya nanti..

Friday, October 22, 2010

Radiator (engine cooling)


Radiator (engine cooling)

From Wikipedia, the free encyclopedia

A typical automobile coolant radiator
Radiators are used for cooling internal combustion engines, chiefly in automobiles but also in piston-engined aircraft, railway locomotives, motorcycles, stationary generating plant or any similar use of such an engine.
They operate by passing a liquid coolant through the engine block, where it is heated, then through the radiator itself where it loses this heat to the atmosphere. This coolant is usually water-based, but may also be oil. It's usual for the coolant flow to be pumped, also for a fan to blow air through the radiator.

Contents

 [hide]

[edit]Automobiles

In automobiles with a liquid-cooled internal combustion engine a radiator is connected to channels running through the engine and cylinder head, through which a liquid (coolant) is pumped. This liquid may be water (in climates where water is unlikely to freeze), but is more commonly a mixture of water and antifreeze in proportions appropriate to the climate. Antifreeze itself is usually ethylene glycolor propylene glycol (with a small amount of corrosion inhibitor).
The radiator transfers the heat from the fluid inside to the air outside, thereby cooling the engine. Radiators are also often used to cool automatic transmissions, air conditioners, and sometimes to cool engine oil. Radiators are typically mounted in a position where they receive airflow from the forward movement of the vehicle, such as behind a front grill. Where engines are mid- or rear-mounted, it is common to mount the radiator behind a front grill to achieve sufficient airflow, even though this requires long coolant pipes. Alternatively, the radiator may draw air from the flow over the top of the vehicle or from a side-mounted grill. For long vehicles, such as buses, side airflow is most common for engine and transmission cooling and top airflow most common for air conditioner cooling.

[edit]Radiator construction

Automobile radiators are constructed of a pair of header tanks, linked by a core with many narrow passageways, thus a high surface area relative to its volume. This core is usually made of stacked layers of metal sheet, pressed to form channels and soldered or brazed together. For many years radiators were made from brass or copper cores soldered to brass headers. Modern radiators save money and weight by using plastic headers and may use aluminium cores. This construction is less easily repaired than traditional materials.

Honeycomb radiator tubes
An earlier construction method was the honeycomb radiator. Round tubes were swaged into hexagons at their ends, then stacked together and soldered. As they only touched at their ends, this formed what became in effect a solid water tank with many air tubes through it.[1]
Vintage cars may also have used radiator cores made from coiled tube, a less-efficient but simpler construction.

[edit]Coolant pumps

 A sectioned view of the cylinder block, radiator and connecting hoses. The hoses link the tops and bottoms of each, without any pump but with an engine-driven cooling fan
Thermosysphon cooling system of 1937, without circulating pump
Radiators first used downward vertical flow, driven solely by a thermosyphon effect. Coolant is heated in the engine, becoming less dense and so rising, cooled, denser coolant in the radiator falling in turn. This effect is sufficient for low-power stationary engines, but inadequate for all but the earliest automobiles. A common fallacy is to assume that a greater vertical separation between engine and radiator can increase the thermosyphon effect. Once the hot and cold headers are separated sufficiently to reach their equilibrium temperatures though, any further separation merely increases pipework length and flow restriction.
All automobiles for many years have used centrifugal pumps to circulate their coolant, driven by geared drives or more commonly by a belt drive. This "fan belt" has a well-established reputation for being slightly unreliable, a failure being rapidly obvious as the engine overheats. Despite the name though, it's thecoolant pump's failure that causes the overheating, not the fan.

[edit]Heater

A system of valves or baffles, or both, is usually incorporated to simultaneously operate a small radiator inside the car. This small radiator, and the associated blower fan, is called the heater core, and serves to warm the cabin interior. Like the radiator, the heater core acts by removing heat from the engine. For this reason, automotive technicians often advise operators to turn on the heater and set it to high if the engine is overheating.

[edit]Temperature control

[edit]Waterflow control


Car engine thermostat
The engine temperature is primarily controlled by a wax-pellet type of thermostat, a valve which opens once the engine has reached its optimum operating temperature.
When the engine is cold the thermostat is closed, with a small bypass flow so that the thermostat experiences changes to the coolant temperature as the engine warms up. Coolant is directed by the thermostat to the inlet of the circulating pump and is returned directly to the engine, bypassing the radiator. Directing water to circulate only through the engine allows the temperature to reach optimum operating temperature as quickly as possible whilst avoiding localised "hot spots". Once the coolant reaches the thermostat's activation temperature it opens, allowing water to flow through the radiator to prevent the temperature rising higher.
Once at optimum temperature, the thermostat controls the flow of coolant to the radiator so that the engine continues to operate at optimum temperature. Under peak load conditions, such as labouring slowly up a steep hill whilst heavily laden on a hot day, the thermostat will be approaching fully open because the engine will be producing near to maximum power while the velocity of air flow across the radiator is low. (The velocity of air flow across the radiator has a major effect on its ability to dissipate heat.) Conversely, when cruising fast downhill on a motorway on a cold night on a light throttle, the thermostat will be nearly closed because the engine is producing little power, and the radiator is able to dissipate much more heat than then engine is producing. Allowing too much flow of coolant to the radiator would result in the engine being over cooled and operating at lower than optimum temperature. A side effect of this would be that the passenger compartment heater would not be able to put out enough heat to keep the passengers warm.
The thermostat is therefore constantly moving throughout its range, responding to changes in vehicle operating load, speed and external temperature, to keep the engine at its optimum operating temperature.

[edit]Airflow control

Other factors influence the temperature of the engine including radiator size and the type of radiator fan. The size of the radiator (and thus its cooling capacity) is chosen such that it can keep the engine at the design temperature under the most extreme conditions a vehicle is likely to encounter (such as climbing a mountain whilst fully loaded on a hot day).
Airflow speed through a radiator is a major influence on the heat it loses. Vehicle speed affects this, in rough proportion to the engine effort, thus giving crude self-regulatory feedback. Where an additional cooling fan is driven by the engine, this also tracks engine speed similarly.
Engine-driven fans are often regulated by a viscous-drive clutch from the drivebelt, which slips and reduces the fan speed at low temperatures. This improves fuel efficiency by not wasting power on driving the fan unnecessarily. On modern vehicles, further regulation of cooling rate is provided by either variable speed or cycling radiator fans. Electric fans are controlled by a thermostatic switch or the engine control unit. Electric fans also have the advantage of giving good airflow and cooling at low engine revs or when stationary, such as in slow-moving traffic.
Before the development of viscous-drive and electric fans, engines were fitted with simple fixed fans that drew air through the radiator at all times. Vehicles whose design required the installation of a large radiator to cope with heavy work at high temperatures, such as commercial vehicles and tractors would often run cool in cold weather under light loads, even with the presence of a thermostat, as the large radiator and fixed fan caused a rapid and significant drop in coolant temperature as soon as the thermostat opened. This problem could be solved by fitting a radiator blind to the radiator which could be adjusted to partially or fully block the airflow. At its simplest the blind was a roll of material (such as canvas or rubber that was unfurled along the length of the radiator to cover the desired portion. Some vehicles had a series of shutters that could be adjusted from the driver's seat to provide a very fine degree of control.

These AEC Regent III RT buses are fitted with radiator blinds, seen here covering the lower half of the radiators.

[edit]Coolant pressure

Because the thermal efficiency of internal combustion engines increases with internal temperature the coolant is kept at higher-than-atmospheric pressure to increase its boiling point. A calibrated pressure-relief valve is usually incorporated in the radiator's fill cap. This pressure varies between models, but typically ranges from 9 psi (0.6 bar) to 15 psi (1.0 bar).
As the coolant expands with increasing temperature its pressure in the closed system must increase. Ultimately the pressure relief valve opens and excess fluid is dumped into an overflow container. Fluid overflow ceases when the thermostat modulates the rate of cooling to keep the temperature of the coolant at optimum. When the coolant cools and contracts (as conditions change or when the engine is switched off) the fluid is returned to the radiator through additional valving in the cap.

[edit]Coolant

Before World War II, radiator coolant was usually plain water. Antifreeze was used solely to control freezing, and this was often only done in cold weather.
Development in high-performance aircraft engines required improved coolants with higher boiling points, leading to the adoption of glycol or water-glycol mixtures. These led to the adoption of glycols for their antifreeze properties.
Since the development of aluminium or mixed-metal engines, corrosion inhibition has become even more important than antifreeze, and in all regions and seasons.

[edit]Boiling or overheating

On this type system, if the coolant in the overflow container gets too low, fluid transfer to overflow will cause an increased loss by vaporizing the engine coolant.
Severe engine damage can be caused by overheating, by overloading or system defect, when the coolant is evaporated to a level below the water pump. This can happen without warning because, at that point, the sending units are not exposed to the coolant to indicate the excessive temperature.
To protect the unwary the cap often contains a mechanism that attempts to relieve the internal pressure before the cap can be fully opened. Some scalding of one's hands can easily occur in this event. Opening a hot radiator drops the system pressure immediately and may cause a sudden ebullition of super-heated coolant which can cause severe burns . .

[edit]History

The invention of the automobile water radiator is attributed to Karl BenzWilhelm Maybach designed the first honeycomb radiator for the Mercedes 35hp.[2]

[edit]Supplementary radiators

It is sometimes necessary for a car to be equipped with a second, or auxiliary, radiator to increase the cooling capacity, when the size of the original radiator cannot be increased. The second radiator is plumbed in series with the main radiator in the circuit. This was the case when the Audi 100 was first turbocharged creating the 200. These are not to be confused with intercoolers.
Some engines have an oil cooler, a separate small radiator to cool the engine oil. Cars with an automatic transmission often have extra connections to the radiator, allowing the transmission fluid to transfer its heat to the coolant in the radiator. These may be either oil-air radiators, as for a smaller version of the main radiator. More simply they may be oil-water coolers, where an oil pipe is inserted inside the water radiator. As water is denser than air, this offers comparable cooling (within limits) from a less complex and thus cheaper oil cooler.
Turbo charged or supercharged engines may have an intercooler, which is an air-to-air or air-to-water radiator used to cool the incoming air charge—not to cool the engine.

[edit]Aircraft

Aircraft with liquid-cooled piston engines (usually inline engines rather than radial) also require radiators. As airspeed is higher than for cars, these are efficiently cooled in flight and so do not require large areas or cooling fans. Many high-performance aircraft however suffer extreme overheating problems when idling on the ground - a mere 7 minutes for a Spitfire.[3]

[edit]Surface radiators

Reducing drag is a major goal in aircraft design, including the design of cooling systems. An early technique was to take advantage of an aircraft's abundant airflow to replace the honeycomb core (many surfaces, with a high ratio of surface to volume) by a surface mounted radiator. This uses a single surface blended into the fuselage or wing skin, with the coolant flowing through pipes at the back of this surface.
As they are so dependent on airspeed, surface radiators are even more prone to overheating when ground-running. Racing aircraft such as the Supermarine S.6B, a racing seaplane with radiators built into the upper surfaces of its floats, have been described as "being flown on the temperature gauge" as the main limit on their performance.[4]
Surface radiators have also been used by a few high-speed racing cars, such as Malcolm Campbell's Blue Bird of 1928.

[edit]Radiator thrust

An aircraft radiator comprises a duct wherein heat is added. As a result, this is effectively a jet engine. High-performance piston aircraft with well-designed low-drag radiators (notably the P-51 Mustang) derived thrust from this effect. The thrust was significant enough to offset the drag of the duct the radiator was enclosed in and allowed the aircraft to achieve zero cooling drag. At one point, there were even plans to equip the Spitfire with a ramjet, by injecting fuel into this duct after the radiator and igniting it. Although ramjets normally require a supersonic airspeed, this light-up speed can be reduced where heat is being added, such as in a radiator duct.

[edit]Steam cooling

Pressurized cooling systems operate by adding heat to the coolant fluid, causing it to rise in temperature in inverse proportion to its specific heat capacity. With the need to keep the final temperature below boiling point, this limits the amount of heat that a given mass-flow of coolant can dissipate.
Attempts were made with aero-engines of the 1930s, notably the Rolls-Royce Goshawk, to exceed this limit by allowing the coolant to boil. This absorbs an amount of heat equivalent to the specific heat of vaporization, which for water is more than five times the energy required to heat the same quantity of water from 0°C to 100°C. Obviously this allows the necessary cooling effect with far less mass of coolant.
The practical difficulty was the need to provide condensers rather than radiators. Cooling was now needed not just for hot, dense liquid coolant, but for low-density vapor. This required a condenser far larger, and with higher drag, than a radiator. For aircraft, especially high-speed aircraft, it was soon realized this configuration was unworkable and so evaporative cooling was abandoned.

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