P&R Labpak - Everything for your laboratory

P&R Labpak - Everything for your laboratory
Our Head Office in St Helens

Friday, 25 January 2013

Hello Sunshine!!


Space Instrument Adds Big Piece to the Solar Corona Puzzle
The Sun is a fascinating object and is not fully understood.  It's a complex entity and a recent scientific instrument has helped to unlock some of its secrets.

The Sun's visible surface, or photosphere, is 10,000 degrees Fahrenheit. As you move outward from it, you pass through a tenuous layer of hot, ionized gas or plasma called the corona. The corona is familiar to anyone who has seen a total solar eclipse, since it glimmers ghostly white around the hidden Sun.

But how can the solar atmosphere get hotter, rather than colder, the farther you go from the Sun's surface? This mystery has puzzled solar astronomers for decades. A suborbital rocket mission that launched in July 2012 has just provided a major piece of the puzzle.

The High-resolution Coronal Imager, or Hi-C, revealed one of the mechanisms that pumps energy into the corona, heating it to temperatures up to 7 million degrees F. The secret is a complex process known as magnetic reconnection.

"This is the first time we've had images at high enough resolution to directly observe magnetic reconnection," explained Smithsonian astronomer Leon Golub (Harvard-Smithsonian Center for Astrophysics). "We can see details in the corona five times finer than any other instrument."

"Our team developed an exceptional instrument capable of revolutionary image resolution of the solar atmosphere. Due to the level of activity, we were able to clearly focus on an active sunspot, thereby obtaining some remarkable images," said heliophysicist Jonathan Cirtain (Marshall Space Flight Center).

Magnetic braids and loops

The Sun's activity, including solar flares and plasma eruptions, is powered by magnetic fields. Most people are familiar with the simple bar magnet, and how you can sprinkle iron filings around one to see its field looping from one end to the other. The Sun is much more complicated.

The Sun's surface is like a collection of thousand-mile-long magnets scattered around after bubbling up from inside the Sun. Magnetic fields poke out of one spot and loop around to another spot. Plasma flows along those fields, outlining them with glowing threads.

The images from Hi-C showed interweaved magnetic fields that were braided just like hair. When those braids relax and straighten, they release energy. Hi-C witnessed one such event during its flight.

It also detected an area where magnetic field lines crossed in an X, then straightened out as the fields reconnected. Minutes later, that spot erupted with a mini solar flare.

Hi-C showed that the Sun is dynamic, with magnetic fields constantly warping, twisting, and colliding in bursts of energy. Added together, those energy bursts can boost the temperature of the corona to 7 million degrees F when the Sun is particularly active.

Selecting the target

The telescope aboard Hi-C provided a resolution of 0.2 arcseconds - about the size of a dime seen from 10 miles away. That allowed astronomers to tease out details just 100 miles in size. (For comparison, the Sun is 865,000 miles in diameter.)

Hi-C photographed the Sun in ultraviolet light at a wavelength of 19.3 nanometers - 25 times shorter than wavelengths of visible light. That wavelength is blocked by Earth's atmosphere, so to observe it astronomers had to get above the atmosphere. The rocket's suborbital flight allowed Hi-C to collect data for just over 5 minutes before returning to Earth.

Hi-C could only view a portion of the Sun, so the team had to point it carefully. And since the Sun changes hourly, they had to select their target at the last minute - the day of the launch. They chose a region that promised to be particularly active.

"We looked at one of the largest and most complicated active regions I've ever seen on the Sun," said Golub. "We hoped that we would see something really new, and we weren't disappointed."

Next steps

Golub said that data from Hi-C continues to be analyzed for more insights. Researchers are hunting areas where other energy release processes were occurring.

In the future, the scientists hope to launch a satellite that could observe the Sun continuously at the same level of sharp detail.

"We learned so much in just five minutes. Imagine what we could learn by watching the Sun 24/7 with this telescope," said Golub.

This research is being published in the journal Nature in a paper co-authored by Cirtain, Golub, A. Winebarger (Marshall), B. De Pontieu (Lockheed Martin), K. Kobayashi (University of Alabama - Huntsville), R. Moore (Marshall), R. Walsh (University of Central Lancashire), K. Korreck, M. Weber and P. McCauley (CfA), A. Title (Lockheed Martin), S. Kuzin (Lebedev Physical Institute), and C. DeForest (Southwest Research Institute).

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

Friday, 18 January 2013

The Galileo Thermometer


A Galileo thermometer is a thermometer made of a sealed glass cylinder containing a clear liquid and several glass vessels of varying densities. As temperature changes, the individual floats rise or fall proportion to their respective density.

It is named after Galileo Galilei because he discovered the principle on which this thermometer is based—that the density of a liquid changes in proportion to its temperature—and invented a thermoscope based on this principle.


Floating in the liquid inside the cylinder are a number of sealed glass bulbs containing coloured liquid. Attached to each bulb is a metal disc whose weight is adjusted to give the bulb the correct buoyancy. As the liquid in the cylinder changes temperature, its density changes and the bulbs are free to move – rising or falling to reach a position where their density is either equal to that of the surrounding liquid or where they are brought to a halt by other bulbs. The bulbs differ in buoyancy by a very small amount and are ordered such that the least dense is at the top and densest at the bottom so that they form a temperature scale.


 

The temperature is typically read from the metal disc hanging from each bulb. Usually a gap separates the top bulbs from the bottom bulbs and then the temperature is between the tag readings on either side of the gap. If a bulb is free-floating in the gap, then its tag reading is closest to the ambient temperature.

To achieve satisfactory accuracy, the weights must be manufactured to a tolerance of less than 1/1000 of one gram (1 mg)


For more information please check out the following links

http://www.h2g2.com/approved_entry/A60734955

http://en.wikipedia.org/wiki/Galileo_thermometer

http://www.howstuffworks.com/question663.htm

Friday, 11 January 2013

Fancy a coffee?

I don't know about you but I can't start the day without a cup of coffee to wake me up.  Other people drink tea but both contain caffeine and it's this that helps kick start your day.
 
Caffeine
Caffeine (C8H10N4O2), known medically as 1,3,7-trimethylxanthine, is a legal stimulant and diuretic used by a large percentage of the Earth's human inhabitants. It can be found naturally in drinks like coffee and tea, and has been artificially introduced into soft drinks like 'Coke' for example. Additionally, small amounts can be found in solid foods like chocolate. The primary method of obtaining pure caffeine is through the decaffeination of coffee and tea, and in this state caffeine appears as a fine white powder. When ingested, this powder is very bitter.
The Effects of Caffeine on the Human Body
The primary effect of caffeine on the human body, and the one that it is most often consumed for, is that of cardiac stimulation - caffeine gives the consumer an 'energy boost' that lasts for a period of time proportional to the amount of caffeine ingested. Cardiac stimulation is achieved indirectly through the release of epinephrine (adrenaline) by the pituitary gland; however, in order to get the pituitary to release epinephrine, caffeine must first cause an increase in nerve cell activity in the brain.

To do this, caffeine takes the place of adenosine, a naturally occurring chemical in the body that slows down nerve cell activity and dilates blood vessels to allow for the increased oxygen uptake necessary during sleep. Caffeine binds to adenosine receptor sites on nerve cells in the brain, and instead of slowing activity, it quickens the pace at which nerve cells fire, warding off drowsiness. It does this by lowering the trigger level for norepinephrine, increasing the likelihood that the firing of one nerve cell in the brain will cause neighbouring cells to fire. This increased activity in the brain alerts the pituitary gland, and it releases epinephrine, setting off the 'fight-or-flight' response in the human. One of the functions of the fight-or-flight response is to release sugar (stored in the liver in the form of glycogen) for immediate use; this is the source of the energy used in the 'boost' provided by ingesting caffeine.

How Caffeine Becomes Addictive
In addition to touching off the fight-or-flight response, caffeine also increases dopamine levels in the brain. Dopamine is a neurotransmitter that activates the pleasure centre in the brain; by manipulating the level of dopamine, caffeine artificially makes the consumer feel good for a short period of time. This is the same mechanism used by both cocaine and heroin.

As well as providing an immediate 'feel-good' sensation, caffeine encourages long-term addiction by depriving the consumer of a good night's sleep. Because adenosine reception is essential to deep sleep and it is blocked by caffeine, consumers wake up feeling irritable, and use caffeine to mentally 'awaken' themselves so that they can function 'properly' - as though they had had a good night's sleep. In this way, a positive feedback loop is created, and consumers cannot abstain from caffeine consumption without adverse effects.

Positive Uses of Caffeine
Caffeine can be used in treatment of acute asthma - because of the overall vasodilation effect caffeine has on the human body, the airways in the lungs are also widened slightly (this effect is known specifically as bronchodilation), enabling someone afflicted with asthma to breathe more easily. While there are more asthma-specific drugs on the market, caffeine will do if there's nothing else around.

Another use of the vasodilation effect of caffeine can be found in headache relief; constriction of blood vessels in the brain can cause major headache pain, and caffeine relieves this pain by widening the blood vessels. For this reason, caffeine can be found in many specialised headache medicines.

Additionally, caffeine can be used to treat ADHD, a hyperactivity disorder. People with ADHD have a lowered ability to focus and a shortened attention span, and stimulants like caffeine (and Ritalin, the most frequently-used treatment for ADHD) allow for longer periods of intense concentration. Unfortunately, the side effects of caffeine make it impractical as a long term solution to most medical conditions.

While caffeine causes negative results when used in the long term, it is - like most things - safe in small amounts.

Friday, 4 January 2013

Useful Conversion Units of Power


Units of Power:

English System

To convert
Multiply by
To obtain
kW
1.341
hp
kW
738
ft-lb/sec
kW
44,260
ft-lb/min
kW
0.948
Btu/sec
kW
56.9
Btu/min
kW
3,413
Btu/hr
hp
0.7455
kW
hp
550
ft-lb/sec
hp
33,000
ft-lb/min
hp
0.707
Btu/sec
hp
42.41
Btu/min
hp
2,545
Btu/hr
ft-lb/sec
0.001356
kW
ft-lb/sec
0.001818
hp
ft-lb/sec
60
ft-lb/min
ft-lb/sec
0.001285
Btu/sec
ft-lb/sec
0.0771
Btu/min
ft-lb/min
0.00002260
kW
ft-lb/min
0.0000303
hp
ft-lb/min
0.01667
ft-lb/sec
ft-lb/min
0.00002141
Btu/sec
ft-lb/min
0.001285
Btu/min
Btu/sec
1.055
kW
Btu/sec
1.415
hp
Btu/sec
778.3
ft-lb/sec
Btu/sec
46,700
ft-lb/min
Btu/sec
60
Btu/min
Btu/min
0.01758
kW
Btu/min
0.02357
hp
Btu/min
12.97
ft-lb/sec
Btu/min
778.3
ft-lb/min
Btu/min
0.01667
Btu/sec

Metric System

To convert
Multiply by
To obtain
watts
0.7376
ft-lb/sec
watts
0.001341
hp
kW
1.3410
hp
cheval-vap
0.9863
hp
ft-lb/sec
1.356
watts
hp
745.7
watts
hp
0.7457
kW
hp
1.0139
cheval-vap