"Your Lord has decreed to you that: You shall worship none but Him, and you shall be kind to your parents; if one or both of them live to their old age in your lifetime, you shall not say to them any word of contempt nor repel them and you shall address them in kind words. You shall lower to them your wings of humility and pray: "O Lord! Bestow on them Your blessings just as they cherished me when I was a little child." The Holy Quran
Saturday, November 21, 2009
Obtaining natural odorants(MAKING OF PERFUMES)
Main article: Extraction (fragrance)
Before perfumes can be composed, the odorants used in various perfume compositions must first be obtained. Synthetic odorants are produced through organic synthesis and purified. Odorants from natural sources require the use of various methods to extract the aromatics from the raw materials. The results of the extraction are either essential oils, absolutes, concretes, or butters, depending on the amount of waxes in the extracted product. [13]
All these techniques will, to a certain extent, distort the odor of the aromatic compounds obtained from the raw materials. This is due to the use of heat, harsh solvents, or through exposure to oxygen in the extraction process which will denature the aromatic compounds, which either change their odor character or renders them odorless.
- Maceration/Solvent extraction: The most used and economically important technique for extracting aromatics in the modern perfume industry. Raw materials are submerged in a solvent that can dissolve the desired aromatic compounds. Maceration lasts anywhere from hours to months. Fragrant compounds for woody and fibrous plant materials are often obtained in this manner as are all aromatics from animal sources. The technique can also be used to extract odorants that are too volatile for distillation or easily denatured by heat. Commonly used solvents for maceration/solvent extraction include hexane, and dimethyl ether. The product of this process is called a "concrete".
- Supercritical fluid extraction: A relatively new technique for extracting fragrant compounds from a raw material, which often employs Supercritical CO2. Due to the low heat of process and the relatively nonreactive solvent used in the extraction, the fragrant compounds derived often closely resemble the original odor of the raw material.
- Ethanol extraction: A type of solvent extraction used to extract fragrant compounds directly from dry raw materials, as well as the impure oily compounds materials resulting from solvent extraction or enfleurage. Ethanol extraction is not used to extract fragrance from fresh plant materials since these contain large quantities of water, which will also be extracted into the ethanol.
- Distillation: A common technique for obtaining aromatic compounds from plants, such as orange blossoms and roses. The raw material is heated and the fragrant compounds are re-collected through condensation of the distilled vapour.
- Steam distillation: Steam from boiling water is passed through the raw material, which drives out their volatile fragrant compounds. The condensate from distillation are settled in aFlorentine flask. This allows for the easy separation of the fragrant oils from the water. The water collected from the condensate, which retains some of the fragrant compounds and oils from the raw material is called hydrosol and sometimes sold. This is most commonly used for fresh plant materials such as flowers, leaves, and stems.
- Dry/destructive distillation: The raw materials are directly heated in a still without a carrier solvent such as water. Fragrant compounds that are released from the raw material by the high heat often undergo anhydrous pyrolysis, which results in the formation of different fragrant compounds, and thus different fragrant notes. This method is used to obtain fragrant compounds from fossil amber and fragrant woods where an intentional "burned" or "toasted" odor is desired.
- Fractionation: Through the use of a fractionation column, different fractions distilled from a material can be selectively excluded to modify the scent of the final product. Although the product is more expensive, this is sometimes performed to remove unpleasant or undesirable scents of a material and affords the perfumer more control over their composition process.
- Expression: Raw material is squeezed or compressed and the oils are collected. Of all raw materials, only the fragrant oils from the peels of fruits in the citrus family are extracted in this manner since the oil is present in large enough quantities as to make this extraction method economically feasible.
- Enfleurage: Absorption of aroma materials into solid fat or wax and then extracting the odorous oil with ethyl alcohol. Extraction by enfleurage was commonly used when distillationwas not possible because some fragrant compounds denature through high heat. This technique is not commonly used in the present day industry due to its prohibitive cost and the existence of more efficient and effective extraction methods. [7]
[edit]Fragrant extracts
Although fragrant extracts are known to the general public as the generic term "essential oils", a more specific language is used in the fragrance industry to describe the source, purity, and technique used to obtain a particular fragrant extract.
Of these extracts, only absolutes, essential oils, and tinctures are directly used to formulate perfumes.
- Absolute: Fragrant materials that are purified from a pommade or concrete by soaking them in ethanol. By using a slightly hydrophilic compound such as ethanol, most of the fragrant compounds from the waxy source materials can be extracted without dissolving any of the fragrantless waxy molecules. Absolutes are usually found in the form of an oily liquid.
- Concrete: Fragrant materials that have been extracted from raw materials through solvent extraction using volatile hydrocarbons. Concretes usually contain a large amount of wax due to the ease in which the solvents dissolve various hydrophobic compounds. As such concretes are usually further purified through distillation or ethanol based solvent extraction. Concretes are typically either waxy or resinous solids or thick oily liquids.
- Essential oil: Fragrant materials that have been extracted from a source material directly through distillation or expression and obtained in the form of an oily liquid. Oils extracted through expression are sometimes called expression oils.
- Pomade: A fragrant mass of solid fat created from the enfleurage process, in which odorous compounds in raw materials are adsorbed into animal fats. Pommades are found in the form of an oily and sticky solid.
- Tincture: Fragrant materials produced by directly soaking and infusing raw materials in ethanol. Tinctures are typically thin liquids. [7]
Products from different extraction methods are known under different names even though their starting materials are the same. For instance, orange blossoms from Citrus aurantium that have undergone solvent extraction produces "orange blossom absolute" but that which have been steam distilled is known as "neroli oil".
[edit]Composing perfumes
Perfume compositions are an important part of many industries ranging from the luxury goods sectors, food services industries, to manufacturers of various household chemicals. The purpose of using perfume or fragrance compositions in these industries is to affect customers through their sense of smell and entice them into purchasing the perfume or perfumed product. As such there is significant interest in producing a perfume formulation that people will find aesthetically pleasing.
[edit]The perfumer
Main article: Perfumer
The job of composing perfumes that will sell is left up to an expert on perfume composition or known in the fragrance industry as the perfumer. They are also sometimes referred to affectionately as a "Nez" (French for nose) due to their fine sense of smell and skill in smell composition.
The composition of a perfume typically begins with a brief by the perfumer's employer or an outside customer. The customers to the perfumer or their employers, are typically fashion houses or large corporations of various industries. The perfumer will then go through the process of blending multiple perfume mixtures and sell the formulation to the customer, often with modifications of the composition of the perfume.
The perfume composition will then be either used to enhance another product as a functional fragrance (shampoos, make-up, detergents, car interiors, etc.), or marketed and sold directly to the public as a fine fragrance.[6]
[edit]Technique
Although there is no single "correct" technique for the formulation of a perfume, there are general guidelines as to how a perfume can be constructed from a concept. Although many ingredients do not contribute to the smell of a perfume, many perfumes include colorants and anti-oxidants to improve the marketability and shelf life of the perfume, respectively.
[edit]Basic framework
Perfume oils usually contain tens to hundreds of ingredients and these are typically organized in a perfume for the specific role they will play. These ingredients can be roughly grouped into four groups:
- Primary scents: Can consist of one or a few main ingredients for a certain concept, such as "rose". Alternatively, multiple ingredients can be used together to create an "abstract" primary scent that does not bear a resemblance to a natural ingredient. For instance, jasmine and rose scents are commonly blends for abstract floral fragrances. Cola flavourant is a good example of an abstract primary scent.
- Modifiers: These ingredients alter the primary scent to give the perfume a certain desired character: for instance, fruit esters may be included in a floral primary to create a fruity floral; calone and citrus scents can be added to create a "fresher" floral. The cherry scent in cherry cola can be considered a modifier.
- Blenders: A large group of ingredients that smooth out the transitions of a perfume between different "layers" or bases. Common blending ingredients include linalool andhydroxycitronellal.
- Fixatives: Used to support the primary scent by bolstering it. Many resins and wood scents, and amber bases are used as fixatives.
The top, middle, and base notes of a fragrance may have separate primary scents and supporting ingredients. The perfume's fragrance oils are then blended with ethyl alcohol and water, aged in tanks for several weeks and filtered through processing equipment to, respectively allow the perfume ingredients in the mixture to stabilize and to remove any sediment and particles before the solution can be filled into the perfume bottles[14].
[edit]Fragrance bases
Instead of building a perfume from "ground up", many modern perfumes and colognes are made using fragrance bases or simply bases. Each base is essentially modular perfume that is blended from essential oils and aromatic chemicals, and formulated with a simple concept such as "fresh cut grass" or "juicy sour apple". Many of Guerlain's Aqua Allegoria line, with their simple fragrance concepts, are good examples of what perfume fragrance bases are like.
The effort used in developing bases by fragrance companies or individual perfumers may equal that of a marketed perfume, since they are useful in that they are reusable. On top of its reusability, the benefit in using bases for construction are quite numerous:
- Ingredients with "difficult" or "overpowering" scents that are tailored into a blended base may be more easily incorporated into a work of perfume
- A base may be better scent approximations of a certain thing than the extract of the thing itself. For example, a base made to embody the scent for "fresh dewy rose" might be a better approximation for the scent concept of a rose after rain than plain rose oil. Flowers whose scents cannot be extracted, such as gardenia or hyacinth, are composed as bases from data derived from headspace technology.
- A perfumer can quickly rough out a concept from a brief by cobbling together multiple bases, then present it for feedback. Smoothing out the "edges" of the perfume can be done after a positive response.
[edit]Reverse engineering
Creating perfumes through reverse engineering with analytical techniques such as GC/MS can reveal the "general" formula for any particular perfume. The difficulty of GC/MS analysis arises due to the complexity of a perfume's ingredients. This is particularly due to the presence of natural essential oils and other ingredients consisting of complex chemical mixtures. However, "anyone armed with good GC/MS equipment and experienced in using this equipment can today, within days, find out a great deal about the formulation of any perfume... customers and competitors can analyze most perfumes more or less precisely."[15]
Antique or badly preserved perfumes undergoing this analysis can also be difficult due to the numerous degradation by-products and impurities that may have resulted from breakdown of the odorous compounds. Ingredients and compounds can usually be ruled out or identified using gas chromatograph (GC) smellers, which allow individual chemical components to be identified both through their physical properties and their scent. Reverse engineering of best-selling perfumes in the market is a very common practice in the fragrance industry due to the relative simplicity of operating GC equipment, the pressure to produce marketable fragrances, and the highly lucrative nature of the perfume market.[14]
[edit]
[edit]Preserving perfume
Fragrance compounds in perfumes will degrade or break down if improperly stored in the presence of:
Proper preservation of perfumes involve keeping them away from sources of heat and storing them where they will not be exposed to light. An opened bottle will keep its aroma intact for several years, as long as it is well stored.[6] However the presence of oxygen in the head space of the bottle and environmental factors will in the long run alter the smell of the fragrance.
Perfumes are best preserved when kept in light-tight aluminium bottles or in their original packaging when not in use, and refrigerated to relatively low temperatures: between 3-7 degrees Celsius (37-45 degrees Fahrenheit). Although it is difficult to completely remove oxygen from the headspace of a stored flask of fragrance, opting for spray dispensers instead of rollers and "open" bottles will minimize oxygen exposure. Sprays also have the advantage of isolating fragrance inside a bottle and preventing it from mixing with dust, skin, and detritus, which would degrade and alter the quality of a perfume.
[edit]Lists of perfumes
Further information: List of Famous Perfumes
Further information: List of celebrity endorsed perfumes
Friday, November 20, 2009
This technology is inspired by water transport in natural leaves. Hence researchers have developed artificial leaves that can generate power from evaporative flow. The concept behind this is that natural leaves constantly lose water through evaporation as water in their veins is pumped up to the top of the tree. This process popularly known as transpiration also creates a mechanical energy in synthetic leaves thus creating power. Now that is one innovative way of generation electricity. Researchers have constructed leaves out of glass wafers with tiny veins through which water can flow. The veins open at the tips of glass leaves where evaporation happens at the rate of 1.5 cm per second.The researchers have wired these leaves by adding metal plates to the walls and then connecting them to a circuit. The metal plates get charged and a capacitor has been made from the two conducting plates separated by an insulation layer. The researchers have added bubbles into the leaf’s veins to periodically interrupt the flow of water. Every time a bubble is passed between the metal plates, it changes the capacitance and generates a small current. Each bubble can create about 2-5 microvolts or 2 microwatts per cubic centimeter. Ofcourse it is much less compared to solar power generation but scientists are working towards increasing the capacity.
[Physorg]
Thursday, November 19, 2009
A chat with Dr.Devi Shetty, Narayana Hrudayalaya (Heart Specialist)
The transcript of the chat is given below. Useful for everyone.
Qn: What are the thumb rules for a layman to take care of his heart?
Ans:
1. Diet - Less of carbohydrate, more of protein, less oil
2.. Exercise - Half an hour's walk, at least five days a week; avoid lifts and avoid sitting for a longtime
3. Quit smoking
4. Control weight
5. Control blood pressure and sugar
Qn: Is eating non-veg food (fish) good for the heart?
Ans: No
Qn: It's still a grave shock to hear that some apparently healthy person
gets a cardiac arrest. How do we understand it in perspective?
Ans: This is called silent attack; that is why we recommend everyone past the age of 30 to undergo routine health checkups.
Qn: Are heart diseases hereditary?
Ans: Yes
Qn: What are the ways in which the heart is stressed? What practices do you suggest to de-stress?
Ans: Change your attitude towards life. Do not look for perfection in everything in life.
Qn: Is walking better than jogging or is more intensive exercise required to keep a healthy heart?
Ans: Walking is better than jogging since jogging leads to early fatigue and injury to joints
Qn: You have done so much for the poor and needy. What has inspired you to do so?
Ans: Mother Theresa , who was my patient
Qn: Can people with low blood pressure suffer heart diseases?
Ans: Extremely rare
Qn: Does cholesterol accumulates right from an early age
(I'm currently only 22) or do you have to worry about it only after you are above 30 years of age?
Ans: Cholesterol accumulates from childhood.
Qn: How do irregular eating habits affect the heart ?
Ans: You tend to eat junk food when the habits are irregular and your body's enzyme release for digestion gets confused.
Qn: How can I control cholesterol content without using medicines?
Ans: Control diet, walk and eat walnut.
Qn: Can yoga prevent heart ailments?
Ans: Yoga helps.
Qn: Which is the best and worst food for the heart?
Ans: Fruits and vegetables are the best and the worst is oil.
Qn: Which oil is better - groundnut, sunflower, olive?
Ans: All oils are bad ..
Qn: What is the routine checkup one should go through? Is there any specific test?
Ans: Routine blood test to ensure sugar, cholesterol is ok. Check BP, Treadmill test after an echo.
Qn: What are the first aid steps to be taken on a heart attack?
Ans: Help the person into a sleeping position , place an aspirin tablet under the tongue with a sorbitrate tablet if available, and rush him to a coronary care unit since the maximum casualty takes place within the first hour.
Qn: How do you differentiate between pain caused by a heart attack and that caused due to gastric trouble?
Ans: Extremely difficult without ECG.
Qn: What is the main cause of a steep increase in heart problems amongst youngsters? I see people of about 30-40 yrs of age having heart attacks and serious heart problems.
Ans: Increased awareness has increased incidents. Also, sedentary lifestyles, smoking, junk food, lack of exercise in a country where people are genetically three times more vulnerable for heart attacks than Europeans and Americans.
Qn: Is it possible for a person to have BP outside the normal range of 120/80 and yet be perfectly healthy?
Ans: Yes.
Qn: Marriages within close relatives can lead to heart problems for the child. Is it true?
Ans : Yes, co-sanguinity leads to congenital abnormalities and you may not have a software engineer as a child
Qn: Many of us have an irregular daily routine and many a times we have to stay late nights in office. Does this affect our heart ? What precautions would you recommend?
Ans : When you are young, nature protects you against all these irregularities. However, as you grow older, respect the biological clock.
Qn: Will taking anti-hypertensive drugs cause some other complications (short / long term)?
Ans : Yes, most drugs have some side effects. However, modern anti-hypertensive drugs are extremely safe.
Qn: Will consuming more coffee/tea lead to heart attacks?
Ans : No.
Qn: Are asthma patients more prone to heart disease?
Ans : No.
Qn: How would you define junk food?
Ans : Fried food like
Qn: You mentioned that Indians are three times more vulnerable. What is the reason for this, as Europeans and Americans also eat a lot of junk food?
Ans: Every race is vulnerable to some disease and unfortunately, Indians are vulnerable for the most expensive disease.
Qn: Does consuming bananas help reduce hypertension?
Ans : No.
Qn: Can a person help himself during a heart attack (Because we see a lot of forwarded emails on this)?
Ans : Yes. Lie down comfortably and put an aspirin tablet of any description under the tongue and ask someone to take you to the nearest coronary care unit without any delay and do not wait for the ambulance since most of the time, the ambulance does not turn up.
Qn: Do, in any way, low white blood cells and low hemoglobin count lead to heart problems?
Ans : No. But it is ideal to have normal hemoglobin level to increase your exercise capacity.
Qn: Sometimes, due to the hectic schedule we are not able to exercise. So, does walking while doing daily chores at home or climbing the stairs in the house, work as a substitute for exercise?
Ans : Certainly. Avoid sitting continuously for more than half an hour and even the act of getting out of the chair and going to another chair and sitting helps a lot.
Qn: Is there a relation between heart problems and blood sugar?
Ans: Yes. A strong relationship since diabetics are more vulnerable to heart attacks than non-diabetics.
Qn: What are the things one needs to take care of after a heart operation?
Ans : Diet, exercise, drugs on time , Control cholesterol, BP, weight..
Qn: Are people working on night shifts more vulnerable to heart disease when compared to day shift workers?
Ans : No.
Qn: What are the modern anti-hypertensive drugs?
Ans : There are hundreds of drugs and your doctor will chose the right combination for your problem, but my suggestion is to avoid the drugs and go for natural ways of controlling blood pressure by walk, diet to
reduce weight and changing attitudes towards lifestyles.
Qn: Does dispirin or similar headache pills increase the risk of heart attacks?
Ans : No.
Qn: Why is the rate of heart attacks more in men than in women?
Ans : Nature protects women till the age of 45.
Qn: How can one keep the heart in a good condition?
Ans : Eat a healthy diet, avoid junk food, exercise everyday, do not smoke and, go for health checkup s if you are past the age of 30 ( once in six months recommended) ....
Wednesday, November 18, 2009
GM crops have a role in preventing world hunger, chief scientist says
The Government should approve trials to develop crops resistant to climate change that would feed a growing population
GETTY IMAGES
The pubic is concerned about the threat to bio-diversity posed by GM crops
ENLARGEGM crops have a role to play in preventing mass starvation across the world caused by a combination of climate change and rapid population growth, a senior government scientist said yesterday.
Professor Robert Watson, the chief scientific adviser at the Department for Environment, Food and Rural Affairs (Defra), called for UK trials of GM foods, arguing that the Government needs to be more open with the public about the risks and benefits of genetically modified foods.
"Over the next 20 to 50 years, the population is going to increase from 6.5 to 9 billion. There will be more extreme weather, more demand for food, meat, and water, a changing climate: it is a very challenging situation, which, if we don't deal with it, could become a nightmare scenario," said Professor Watson. "We have to look at all the technologies, policies and practices, all forms of bio-tech, including GM."
"We need to have trials in the UK, and to make them open and transparent," Professor Watson added. "We'd have to protect them, to stop them getting trashed. There are a whole range of situations in which science can play a very important role. We'll need seeds which are more temperature- and pest-tolerant."
The suggestion that the Government should resume trials of GM crops, which halted in 2008, has generated criticism from environmental campaigners who point out that the growth of herbicide-resistant GM crops in countries such as Argentina and the US has seen dramatic increases in pesticide use and created pesticide-resistant "super-weeds".
"If the Government does make the mistake of approving new field trials, then they should prepare themselves for the response of local communities, who will be worried about the risks that these crops pose," said Clare Oxborrow, senior food campaigner at Friends of the Earth. "The issues that applied a few years ago still apply. The risks of contamination have not been addressed; nor have any health and safety concerns."
A 2008 trial by Leeds University, in which potatoes were genetically modified to resist a parasitic worm, provoked anger from local residents and was destroyed by environmentalists. In addition to environmental fears about loss of bio-diversity and harm to other crops, consumers are also concerned about the possible health risks posed by GM food.
A study conducted by Eurobarometer in 2008 which surveyed 25,000 EU citizens found that 61 per cent thought that animal cloning was morally wrong. Meanwhile, a Gallup poll in 2005 found that 54 per cent of Britons were opposed to bio-technology in food production.
Professor Watson acknowledged that the subject is controversial. "It is similar to nuclear power," he said. "We have to look at all the risks and benefits, real and perceived, and tell the public what we are trying to achieve."
In 2008, however, Professor Watson led a study for the International Assessment of Agricultural Knowledge, Science and Technology for Development, of which he is the director, which found that GM foods are likely to play only a small role in feeding the world's poor. The report highlighted that the "assessment of the technology lags behind its development".
The chief scientist's comments add weight to the claims of the Royal Society which last month argued that GM crops will prove important in preventing future food shortages. The controversial report called for a 10-year research programme, in which £200m a year would be spent on science that improves crops and sustainable crop management – including research into GM crops.
However, Professor Watson emphasised that GM foods could only play one part in solving a world food crisis, stressing that improving farming in developing countries is also vital. He recommends ending farming subsidies in developed countries, which would make the price of food produced in developing nations more competitive. He also spoke of the need to improve infrastructure, such as loans for farmers, and improve African farmers' education.
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