Efficient Air conditioning discussed

Will the answer to lower energy, efficient air conditioning systems come from the computing industry?

The big increasing number of data centres that house computer servers could be among the first to benefit from some of these developments in cooling technology. These data centres use a lot of energy. IBM reckons that in some centres about half of all the electricity consumed is spent cooling equipment. Mr Collins’s company, Synergetics, is working on what it calls a “surgical ventilation” system which uses small tubes with fans that whisk heat away from hot components inside servers before it warms nearby parts. This heat could then be used to power thermal air-conditioning. And, of course, the fans will be aerodynamically perfect.

(eg. If blades were designed for better aerodynamic efficiency, instead of for being stamped from sheet metal as cheaply as possible, the electricity consumption of many cooling systems could, he says, be cut by a third. )

Or again "Nature's best-Water beats all contenders"

Evaporative coolers are a cheap alternative to refrigerative air-conditioning. The air near a splashing waterfall or fountain is cooler than the surrounding area because water droplets remove heat as they evaporate. Spraying water inside a cooling tower while air is blown through will have the same effect. Whereas refrigerative systems reduce the humidity of air (because some water vapour condenses and is drained away), evaporative coolers increase humidity. This means they tend to be more popular in dry climates.

However, researchers at the National Renewable Energy Laboratory (NREL) in Colorado have designed an evaporative system that sprays ambient-temperature water into warm air to cool it, but in a way that also lowers the humidity. NREL uses syrupy liquids which contain salty desiccants to soak up the humidity. Hot water is used to heat the syrups and dry them out. NREL’s technology, known as “desiccant-evaporative cooling”, is still being developed, but it requires little power, not least because the hot water can be obtained from solar panels. Ron Judkoff of NREL thinks the process will consume only about a fifth of the energy of conventional air-conditioners, depending how dry the climate is to begin with.


More from the Economist Science & Technology pages...


Water beats all contenders"

Product	Latent Heat of Evaporation *)
	(kJ/kg)	(Btu/lb)

Water

2257

970.4

 

The Cost of Cartilage maintenance better than surgical repair?

Glucosamine and chondroitin are widely taken to help relieve knee pain from osteoarthritis but do they work?

The GAIT Study

Double blind

The study, like most good medical studies, was done ‘double blind’, that is neither the patients nor the people administering to them knew which treatment the patient was on.

MORE cf link below
But when results of the group of patients with moderate to severe pain was analysed the investigators found that the combination of glucosamine and chondroitin sulphate WAS significantly effective for pain relief!

ie a healthy dynamic life style may be pursued?
(This is true in my case - Add my experience to the study -Chondrosulf alone 400mg x 3 per day.

The GUIDE findings
Both glucosamine sulphate and acetaminophen were more effective in reducing pain than placebo. Patients taking glucosamine sulphate exhibited more relief than patients on acetaminophen.

It was concluded that once-daily 1500 mg oral doses of glucosamine sulphate may be the preferred treatment for knee osteoarthritis.

Note
It must be noted that unlike the GAIT study that was publicly funded the GUIDE study was sponsored by the manufacturers of the glucosamine compound that was used in the trial.


In both the GAIT and GUIDE studies 1500mg of glucosamine daily was used and in the GAIT study 1200mg of chondroitin daily was used. However, some manufacturers suggest that glucosamine and chondroitin sulphate supplements should be taken in two phases, for example -

* A loading phase of a month of increased levels of glucosamine (up to 2250mg) and 1200mg of chondroitin sulphate.
* A maintenance phase of 1500mg of glucosamine and 800mg of chondroitin sulphate.

Other suggestions are that glucosamine and chondroitin sulphate doses should be calculated based on a person’s body weight. One recommendation is 20mg of glucosamine for every 1kg of body weight, whilst another suggestion is as follows:

* If body weight is less than 54.5kg take 1,000mg glucosamine and 800mg chondroitin sulphate.
*
* If body weight is between 54.5 and 91kg take 1,500mg glucosamine and 1,200 mg chondroitin sulphate.
*
* If body weight is more than 91kg take 2,000mg glucosamine and 1,600mg chondroitin sulphate.

Are these ploys by supplement companies to sell more of their product or is there a scientific basis for these recommendations? Well, at present the evidence for doses and schedules is fairly sparse and that is one of the reasons why daily doses of 1500mg of glucosamine and 1200mg of chondroitin sulphate are common recommendations.

What about the source of these products?

Chondroitin sulphate is usually produced from cow (bovine) cartilage but can be produced from pig (porcine), chicken and even shark cartilage. Glucosamine on the other hand is derived from shellfish, usually shrimp, lobster or crab shells.

An important and informative discussion followed cf link
en référence à :

"Other factors   Chondroitin sulphate production in the body can be hindered if there is a deficiency of some key vitamins and minerals, in particular manganese, vitamin C and vitamin A. As participants in the GAIT study didn’t appear to undergo a dietary analysis prior to the start of the trial it is possible that some individuals may have had deficiencies in these key substances."
- Cartilage Health - Glucosamine and Chrondroitin Supplement (afficher sur Google Sidewiki)