Sunday, June 30, 2013

Crayon for Emergency

 Do you have crayons where it was stuck anywhere unused because in one set of color in a box is no longer complete and you have to buy new set of box?Then you may use it for recycling. When you run out of candle. You can use a crayon instead of a candle in case of Emergency. It will burn for 30 minutes. 
 But take necessary precautions when you use this crayon or candle. Put it on a glass /candle holder when lit for safety. Keep Away from curtains or combustible materials when using candles or anything with fire to protect lives and properties. Do not leave burning candle unattended. Somebody might get bump into it. Children might want to play with it so keep out of reach of children.  Better to teach them not touch anything that uses fire, even the lighter/fire matchbox(posporo).   source: General Knowledge

Friday, June 28, 2013

Japan Eases Visa Rules for Pinoys

 By Pia Lee-Brago (The Philippine Star) | Updated June 28, 2013 -      MANILA, Philippines - The Japanese embassy in Manila clarified yesterday that Japan has not lifted the visa requirement for Filipinos but is giving multiple-entry visas to Filipinos.
The embassy made the clarification following reports that Japan had lifted its visa requirement for the Philippines.
“However, Japan has opened multiple-entry visas to Filipinos. Japan will continue to accept and deliver visa applications for Japan through accredited agencies,” it said.
Starting July 1, Filipinos could apply for multiple-entry visas to Japan, the Japan Ministry of Foreign Affairs said.
The Department of Foreign Affairs (DFA) welcomed last June 12 the Japanese government’s decision to relax visa policies, saying the easing of Japan’s visa requirement is expected to boost tourism.
A Kyodo news agency report said the Japanese government had set a goal of increasing the number of visitors from Southeast Asia by 2.5 times the current level to 2 million in 2016 as part of the 2013 white paper on tourism that was adopted last June 11.

the same day to waive visa requirements for tourists from Thailand and Malaysia and allow the issuance of multiple-entry visas for visitors from the Philippines and Vietnam Japanese Ambassador Toshinao Urabe said the visa requirement for visitors from the Philippines was retained because “overstaying cases are high among Filipinos – the third after China and Korea.”
To help meet the target, the Cabinet of Prime Minister Shinzo Abe decided the same day to waive visa requirements for tourists from Thailand and Malaysia and allow the issuance of multiple-entry visas for visitors from the Philippines and Vietnam Japanese Ambassador Toshinao Urabe said the visa requirement for visitors from the Philippines was retained because “overstaying cases are high among Filipinos – the third after China and Korea..Tokyo will relax travel visa requirements for the fast-growing Southeast Asian nations as part of efforts to boost tourism to spur Japan’s economic growth.   The white paper underlined the need for the Japanese tourism industry to cater to the needs of Muslims, such as those from Indonesia and Malaysia, by offering spaces for prayers at hotels and other places, as well as catering to their dietary habits.
“We expect the easing of the requirements and introduction of multiple-entry visa facility for Filipino nationals would encourage more of our citizens to visit Japan and will create more opportunities for economic and people exchanges between our two countries,” Hernandez said in a press briefing.
The Japanese Foreign Ministry said this latest development is part of Association of Southeast Asian Nations (ASEAN)-Japan Friendship and Cooperation celebrations.
An ordinary Machine-Readable Passport (MRP) that meets International Civil Aviation Organization (ICAO) standards or an ordinary IC passport is also required.
“The further development of Japan-Philippines exchange is expected as a result of the issuance of multiple entry visas, including increases in the number of tourist from the Philippines who visit Japan and the enhancement of the ease of business transactions between the two countries,” the statement said.
source:http://www.philstar.com/headlines/2013/06/28/959150/japan-eases-visa-rules-pinoys                                  credit to:https://news.google.com

Kaspersky: Phishing attacks rise;Warning also to other Issues

Category IT SecurityArticle date 27 June 2013
The number of phishing crimes being committed has risen, according to a new study released by Kaspersky.

Some 37.3 million internet users around the world were the victims of attacks in 2012-13 - up 87 per cent from the year before.

Phishing is the act of contacting a person or organisation and lying about who you are or what company you represent. Many scammers register domain names that closely match those of large corporations such as Mastercard and Sony to lull consumers into a false sense of security, before stealing valuable data.

Victims were seen to come from a number of different countries, but the population of Russia, the US, India, Vietnam and the UK were targeted by the cyber-attacks most often.

Around 56 per cent of all identified sources of phishing scams came from just ten nations, with Germany, the UK and US among those suspected of participating most often in the criminal behavior.

However, it was not just individuals that were attacked by the cyber thieves - threats against corporations also rose dramatically and nearly 20 per cent of victims did business in the financial sector - a lucrative target for skillful con-artists.

Yahoo!, Google, Amazon and Facebook were the top private sector targets but online games services including Playstation Network, Steam, Xbox live and Wii shop also suffered from substantial levels of activity.

One of the most common ways people were targeted was, ironically, by scams claiming to offer anti-virus technology products that often have keylogging or trojan horse infections built-in to log key pieces of information that can be sold on to third parties for profit.

The study released by Kaspersky concluded: "Both phishing itself and the diversity of the types of phishing attacks are experiencing rapid growth and affecting an enormous number of users and organisations around the world.

"Relative simplicity [in] setting up these types of attacks and the high probability of gaining some type of reward from a successful phishing ploy has attracted more and more malicious users to phishing."

Posted by Paul Sells
Breaking news from ihotdesk, IT Security Solutions in LondonADNFCR-8000229-ID-801605361-ADNFCR

Read more: http://www.ihotdesk.co.uk/article/801605361/Kaspersky:-Phishing-attacks-rise#ixzz2XSl4LIdP 
Under Creative Commons License: Attribution Non-Commercial No Derivatives 

source:https://news.google.com/?ar=1372378089            TECNOLOGY
Apple ID Data 
As Apple's popularity grows, so does the desire among fraudsters to make money from the people who own the company's devices. The cybercriminals are aiming to steal Apple ID data which provides access to users' personal information stored in iCloud (e.g., photographs, contacts, documents, email, etc.) as well as to the purchases made in the company's iTunes Store. Many malicious users go further and try to the steal bank card details used to pay for those purchases.
The scammers make use of phishing sites that imitate the official apple.com site. Since the beginning of 2012 until the present time this has resulted in a significant increase in the number of web antivirus detections triggered by users of our products attempting to visit such sites. During that period we have seen on average around 200,000 detections per day. By contrast, in 2011 the figure stood at around 1,000 detections per day. 
 written article/source by: Nadezhda Demidova              source:http://www.securelist.com/en/blog
Script Worm
Recent months have produced little of interest among worms written in Java and script languages such as JavaScript and VBScript. The main reason behind this was the limited proficiency of the virus writers, whose creations were anything but remarkable. However, a couple of malware samples grabbed our attention; their complexity is testimony to the fact that professionals sometimes get involved as well.
Kaspersky Lab’s products detect these special worms as Worm.JS.AutoRun and Worm.Java.AutoRun. They are also detected by heuristic methods as HEUR:Worm.Script.Generic and HEUR:Worm.Java.Generic respectively.
These two worms have three key features in common: heavy obfuscation, backdoor-type essential payloads, and similar methods of propagation. Both worms spread by copying themselves and the configuration file autorun.inf into the root folders of logical volumes of removable storage media and network disks. If these infected storages are opened on other computers, the infection can spread. Having infected the operating system and established a foothold on the victim computer, the malicious programs deploy their principal payload.
For months, the number of AutoRun worms detected on Kaspersky Lab users’ computers remained essentially unchanged. According to Kaspersky Security Network data, half of all script worms spread themselves this way. As for Java worms, this is not their usual method of propagation. However, in the last three months we have seen a dramatic rise in the number of new Worm.Java.AutoRun modifications
written artilcle and source:Konstantin Markov
Note; I am not technology expert nor technology savvy but I need to inform my readers from  whom I have believed their line of expertise from the articles/blog they have written/published.

Phl except gov't 'relatively safe' from cyber attacks

Phl except gov't 'relatively safe' from cyber attacks
 (philstar.com) | ANILA, Philippines - While the Philippines in general is safe from cyber attacks and espionage, its government and businesses remain vulnerable, a security software firm's official said.
"The Philippines seems relatively safe from major mobile malware and cyber espionage (but) attacks against government institutions and corporations are possible," Kaspersky Lab Southeast Asia Jimmy Fong said in a statement Wednesday.
Fong said that recent denial-of-service or DDOS attacks against state-owned sites are indicators that the country's government systems are still at risk.
“These attacks can be dangerous for any institution especially now that the Philippines is linked to other countries via broadband Internet connections. Security even in the virtual world is the responsibility of everyone and putting in place the best security solutions is paramount,” he said.
Credit to :https://news.google.com

Wednesday, June 26, 2013

Health-Chikungunya

Chikungunya fever is a viral disease transmitted to humans by the bite of infected mosquitoes. Chikungunya virus is a member of the genus Alphavirus, in the family Togaviridae. Chikungunya fever is diagnosed based on symptoms, physical findings (e.g., joint swelling), laboratory testing, and the possibility of exposure to infected mosquitoes. There is no specific treatment for chikungunya fever; care is based on symptoms. Chikungunya fever is not usually fatal. Steps to prevent infection with chikungunya virus include use of insect repellent, protective clothing, and staying in areas with screens. Chikungunya virus was first isolated from the blood of a febrile patient in Tanzania in 1953, and has since been cited as the cause of numerous human epidemics in many areas of Africa and Asia and most recently in limited areas of Europe. Chikungunya virus is not currently found in the United States.

Transmission of Chikungunya Virus

Chikungunya virus is spread by the bite of an infected mosquito. Mosquitoes become infected when they feed on a person infected with chikungunya virus. Infected mosquitoes can then spread the virus to other humans when they bite. Monkeys, and possibly other wild animals, may also serve as reservoirs of the virus.
Image: Aedes aegypti mosquito
The Aedes aegypti mosquito is the principle vector responsible for transmitting the chikungunya virus to humans.
Aedes aegypti (the yellow fever mosquito), a species of mosquito that breeds in household containers, is an aggressive biter during the day, and is attracted to humans for bloodmeals. Aedes albopictus (the Asian tiger mosquito) has also played a role in human transmission in Asia, Africa, and Europe. Various forest-dwelling mosquito species in Africa have been found to be infected with the virus.

Symptoms and Treatment

Chikungunya virus infection can cause a debilitating illness, most often characterized by fever, headache, fatigue, nausea, vomiting, muscle pain, rash, and joint pain. The term ‘chikungunya’ means ‘that which bends up’ in the Kimakonde language of Mozambique.
Acute chikungunya fever typically lasts a few days to a few weeks, but as with dengue, West Nile fever and other arboviral fevers, some patients have prolonged fatigue lasting several weeks. Additionally, some patients have reported incapacitating joint pain, or arthritis which may last for weeks or months. The prolonged joint pain associated with chikungunya virus is not typical of dengue. No hemorrhagic cases related to chikungunya virus infection have been conclusively documented in the scientific literature. Co-circulation of dengue fever in many areas may mean that chikungunya fever cases are sometimes clinically misdiagnosed as dengue infections, therefore the incidence of chikungunya fever could be much higher than what has been previously reported.
The incubation period (time from infection to illness) can be 2-12 days, but is usually 3-7 days. “Silent” chikungunya virus infections (infections without illness) do occur, but how commonly this happens is not yet known. Chikungunya virus infection (whether clinically apparent or silent) is thought to confer life-long immunity. Fatalities related to chikungunya virus are rare.
Pregnant women can become infected with chikungunya virus during all stages of pregnancy and have symptoms similar to other individuals. Most infections occurring during pregnancy will not result in the virus being transmitted to the fetus. The highest risk for infection of the fetus/child occurs when a woman has virus in her blood (viremic) at the time of delivery. There are also rare reports of first trimester abortions occurring after chikungunya infection. Pregnant women should take precautions to avoid mosquito bites. Products containing DEET can be used in pregnancy without adverse effects. Currently, there is no evidence that the virus is transmitted through breast milk.
There is no vaccine or specific antiviral treatment currently available for chikungunya fever. Treatment is symptomatic and can include rest, fluids, and medicines to relieve symptoms of fever and aching such as ibuprofen, naproxen, acetaminophen, or paracetamol. Aspirin should be avoided. Infected persons should be protected from further mosquito exposure (staying indoors in areas with screens and/or under a mosquito net) during the first few days of the illness so they can not contribute to the transmission cycle.

Diagnostic Testing

A presumptive diagnosis of an arboviral disease is often based on the patient's clinical features, places and dates of travel (if the patient is from a non-endemic country or area), activities, and epidemiologic history of the location where infection occurred.
Laboratory diagnosis of arboviral infections is generally accomplished by testing of serum or cerebrospinal fluid (CSF) to detect virus-specific IgM and neutralizing antibodies.
In fatal cases, nucleic acid amplification, histopathology with immunohistochemistry, and virus culture of biopsy or autopsy tissues can also be useful. Only a few state laboratories or other specialized laboratories, including those at CDC, are capable of doing this specialized testing.
Instructions for sending diagnostic specimens to CDC’s Arbovirus Diagnostic Laboratory can be found at the following site: http://www.cdc.gov/ncezid/dvbd/specimensub/index.html .
Test results are normally available 4 to 14 days after specimen receipt. Reporting times for test results may be longer during summer months when arbovirus activity increases. Receipt of a hard copy of the results will take at least 2 weeks after testing is completed. Initial serological testing will be performed using IgM-capture ELISA, MIA (Microsphere-based Immunoassay) and IgG ELISA. If the initial results are positive, further confirmatory testing may delay the reporting of final results. ALL RESULTS WILL BE SENT TO THE APPROPRIATE STATE HEALTH DEPARTMENT. Notify your state health department of any direct submissions to CDC.

Monday, June 24, 2013

Health-Leptospirosis

Leptospirosis is an infectious disease of humans and animals that is caused by pathogenic spirochetes of the genus Leptospira (see the image below). It is considered the most common zoonosis in the world.
A scanning electron micrograph depicting Leptospir
A scanning electron micrograph depicting Leptospira atop a 0.1-ยตm polycarbonate filter.
(This image is in the public domain and thus free of any copyright restrictions.
Creidt/Courtesy of the Centers for Disease Control/Rob Weyant)

Credit/Source: 
http://emedicine.medscape.com

Leptospirosis is a bacterial disease that affects humans and animals. It is caused by bacteria of the genus Leptospira. In humans, it can cause a wide range of symptoms, some of which may be mistaken for other diseases. Some infected persons, however, may have no symptoms at all.
Without treatment, Leptospirosis can lead to kidney damage, meningitis (inflammation of the membrane around the brain and spinal cord), liver failure, respiratory distress, and even death.

Risk of Exposure

Leptospirosis occurs worldwide, but is most common in temperate or tropical climates. It is an occupational hazard for many people who work outdoors or with animals.
The disease has also been associated with swimming, wading, kayaking, and rafting in contaminated lakes and rivers. As such, it is a recreational hazard for campers or those who participate in outdoor sports. The risk is likely greater for those who participate in these activities in tropical or temperate climates.
In addition, incidence of Leptospirosis infection among urban children appears to be increasing.

 Note: When there is flood due to heavy rainstorm and has to pass or walk over on the flood and you have skin disease or open wound be careful it can go through that wound the water that has been contaminated of animals with their urine/feces. It may cause also be aware of the possibility of infection. Or by any chance /accidentally to swallow flood water while walking/swimming almost a high water of the flood because there is no other way to leave the flooded area. Have yourself be seen by physician or have a laboratory procedure. Wear footwear to protect your lower limbs by wearing boots.

Symptoms

In humans, Leptospirosis can cause a wide range of symptoms, including:
  • High fever
  • Headache
  • Chills
  • Muscle aches
  • Vomiting
  • Jaundice (yellow skin and eyes)
  • Red eyes
  • Abdominal Pain
  • Diarrhea
  • Rash
Many of these symptoms can be mistaken for other diseases. In addition, some infected persons may have no symptoms at all.
The time between a person's exposure to a contaminated source and becoming sick is 2 days to 4 weeks. Illness usually begins abruptly with fever and other symptoms. Leptospirosis may occur in two phases:
  • after the first phase (with fever, chills, headache, muscle aches, vomiting, or diarrhea) the patient may recover for a time but become ill again.
  • if a second phase occurs, it is more severe; the person may have kidney or liver failure or meningitis. This phase is also called Weil's disease.
The illness lasts from a few days to 3 weeks or longer. Without treatment, recovery may take several months.

Treatment

Leptospirosis is treated with antibiotics, such as doxycycline or penicillin, which should be given early in the course of the disease.
Intravenous antibiotics may be required for persons with more severe symptoms. Persons with symptoms suggestive of leptospirosis should contact a health care provider.

Prevention

The risk of acquiring leptospirosis can be greatly reduced by not swimming or wading in water that might be contaminated with animal urine, or eliminating contact with potentially infected animals.
Protective clothing or footwear should be worn by those exposed to contaminated water or soil because of their job or recreational activities.
For more information :
credit/source: http://www.cdc.gov/leptospirosis/
Courtesy of Center for Disease and Prevention

Sunday, June 23, 2013

To Remove Pet Urine Odor from Carpets

Photo: To Remove Pet Urine Odor from Carpets: 

~ Mix 1/2 cup vinegar and 1/2 cup water and pour over the old urine. If this amount doesn't cover the urine stain, double it.

~ Blot up the vinegar solution with paper towels by standing it on it to pull all of the moisture out.

~ Sprinkle the stain with baking soda.

~ Mix 1/4 cup hydrogen peroxide with 1 tsp. liquid dish soap and spread it over the area. Use a stiff, bristle brush to work it into the carpet. (Be sure to test on an inconspicuous place first)

~ Vacuum up the cleaner residue when it is dry. This will usually take overnight. Point a fan at it to speed drying.Mix 1/2 cup vinegar and 1/2 cup water and pour over the old urine. If this amount doesn't cover the urine stain, double it.

~ Blot up the vinegar solution with paper towels by standing it on it to pull all of the moisture out.

~ Sprinkle the stain with baking soda.

~ Mix 1/4 cup hydrogen peroxide with 1 tsp. liquid dish soap and spread it over the area. Use a stiff, bristle brush to work it into the carpet. Note: (Be sure to test on an inconspicuous place first)

~ Vacuum up the cleaner residue when it is dry. This will usually take overnight. Point a fan at it to speed drying.

Saturday, June 22, 2013

Contact Lens: Care Tips-health

Nature's Eye

"Contact lens: care tips"

1. Avoid wearing contact lenses while swimming as there are bacteria in the water that can adhere to your lenses and cause infections. If you do swim with your contacts, you should wear goggles over them and you should disinfect them immediately afterwards.

2. You should never share your contact lenses with anyone as it may cause an eye infection.

3. You should clean the lenses by rinsing them with the solution and not rub the lenses to remove dirt and protein deposits.

4. Contact lenses should always be stored in a sterile carrying case filled with fresh solution, which ensures the lenses remain moist and clean.

5. Many people use their contact lenses longer than recommended. This leads to loss of comfort and an increase risk of eye infections.

6. Some contact lenses have UV protection built into the lenses but you should still use sunglasses because the contact lenses will only protect the part of your eye that it covers.

7. You should wash and dry your hands thoroughly before removing contact lenses. After removing them, gently rub them with cleaning solution and store them in a case filled with solution.

8. Falling asleep while wearing disposable contact lenses is a common problem. Sleeping with your contact lenses in your eyes can cause damage and discomfort.

9. You should always have a back-up pair of eyeglasses - even if you wear your contacts all the time.

10. Contact lenses are extremely popular world over as fashion statements. Avoid wearing coloured contact lenses as they can cause conjunctivitis, corneal oedema, allergic reactions, corneal abrasions and reduction in vision.

11. You must follow the rules of hygiene recommended by the contact lenses manufacturer and doctor. The lenses must be stored correctly and never worn beyond the stipulated time.

12. Always consult a doctor if there is any eye redness or irritation.

13. Always buy contact lenses from reputable manufacturers and follow the instructions given by the doctor about wear and tear.

14. Insert contact lens before applying eye makeup and remove lenses before removing the makeup.

15. The lens solutions must be recommended by a doctor. Keep the tip of the lens solution bottles clean and never use expired solutions.

16. Protect your eyes against infections by never using saliva, strange soaps, and un-sterilised water or solutions to clean the lenses.

source: General Knowledge

Thursday, June 20, 2013

How to Repair Wood Furniture with Natural Ingredients

Photo: I have been asked to repost this again. Please, be sure to SHARE in order to SAVE to your timeline so you can return to it, when needed! :)

Naturally Repair Wood With Vinegar and Canola Oil. So, for a super cheap, use 3/4 cup of oil, add 1/4 cup vinegar. white or apple cider vinegar, mix it in a jar, then rub it into the wood. You don’t need to wipe it off; the wood just soaks it in.
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 To SAVE this idea, be sure to click SHARE so it will store on your personal page.
 Click and join us here---for more every day fun, tips, recipes, weight loss support & motivation.. and learn about Skinny Fiber! 
Healthy Body Helpers
 And Please feel free to follow me and ADD me as a friend for recipes, tips, DIY's and much moreNaturally Repair Wood With Vinegar and Canola Oil. So, for a super cheap, use 3/4 cup of oil, add 1/4 cup vinegar. white or apple cider vinegar, mix it in a jar, then rub it into the wood. You don’t need to wipe it off; the wood just soaks it in.
courtesy of S. Glavic
Note: Clean any dust on the wood and test a small portion to see on how it will react before applying all over the wood furnishes you are trying to restore.

Tuesday, June 18, 2013

GALLIUM

CHEMICOOL.COM

Data Zone

Classification:Gallium is an ‘other metal’
Color:silvery-blue
Atomic weight:69.723
State:solid
Melting point:29.76 oC, 302.91 K
Boiling point:2200 oC, 2473 K
Electrons:31
Protons:31
Neutrons in most abundant isotope:40
Electron shells:2,8,18,3
Electron configuration:[Ar] 3d10 4s2 4p1
Density @ 20oC:5.907 g/cm3
Crystals of gallium metal.


Discovery of Gallium

Before the discovery of gallium its existence and main properties were predicted by Russian chemist Dmitri Mendeleev. He named the hypothetical element eka-aluminum as he predicted the element would sit below aluminum on the periodic table.
Gallium was discovered by French chemist Paul E. Lecoq de Boisbaudran through a spectroscope in 1875 in Paris.
Its now characteristic spectrum (two violet lines) identified it as a new element.
De Boisbaudran extracted gallium in the first instance from a zinc blende ore from the Pyrenees and obtained initially only 0.65 grams from 430 kilograms of ore. He isolated gallium by electrolysis of its hydroxide in potassium hydroxide solution.
The origin of the name comes from the Latin word ‘Gallia’, meaning France.
Appearance and Characteristic
Harmful effects:
Gallium is considered to be non-toxic.
Characteristics:
Gallium is a silvery, glass-like, soft metal. It sits close to the non-metals in the periodic table and its metallic properties aren’t as obviously metallic as most other metals. Solid gallium is brittle and is a poorer electrical conductor than lead.
The solid metal fractures conchoidally. (Conchoidally means like a shell – the fractured surfaces are curved like a sea shell.)
Gallium has the second largest liquid range of any element and is one of the few metals that is liquid near room temperature (m.pt. 29.76 oC, 85.6 oF ), melting in the hand.
The other metals with this property are cesiumfrancium andmercury.
Bromine is the only non-metallic element that is liquid at or around room-temperature.
Gallium liquid clings to or wets glass and similar surfaces.
Gallium also has the unusual property that (like water) it expands as it freezes.
Four other elements expand when they freeze; silicon,bismuthantimony and germanium

Uses of Gallium

Low melting gallium alloys are used in some medical thermometers as non-toxic substitutes for mercury.
Gallium arsenide is used in semiconductor production mainly for laser diodes, light-emitting diodes and solar panels. It is also used to create brilliant mirrors.

Abundance and Isotopes

Abundance earth’s crust: 19 parts per million by weight, 5.5 parts per million by moles
Abundance solar system: 40 parts per billion by weight, 0.6 parts per billion by moles
Cost, pure: $220 per 100g
Cost, bulk: $ per 100g
Source: Gallium does not exist free in nature and there are no minerals with any substantial gallium content. Commercially, most gallium is extracted as a byproduct of aluminum and zinc production. Gallium is also extracted from the flue dusts of coal.
Isotopes: Gallium has 24 isotopes whose half-lives are known, with mass numbers 61 to 84. Of these, two are stable: 69Ga and 71Ga with natural abundances of 60.1% and 39.9% respectively.

References

1. Photo by Foobar, GNU FD.

Cite this Page

For online linking, please copy and paste one of the following:
<a href="http://www.chemicool.com/elements/gallium.html">Gallium</a>
or
<a href="http://www.chemicool.com/elements/gallium.html">Gallium Element Facts</a>
To cite this page in an academic document, please use the following MLA compliant citation:
"Gallium." Chemicool Periodic Table. Chemicool.com. 17 Oct. 2012. Web. 6/18/2013 
<http://www.chemicool.com/elements/gallium.html>.

NEW WORLD ENCYCLOPEDIA
Gallium (chemical symbol Ga, atomic number 31) is a rare, soft, silvery metal. It is a brittle solid at low temperatures, but it liquefies slightly above room temperature and melts in the hand. It is one of only a few materials that expands when freezing (like water), and its liquid form has a higher density than the solid form (like water). Gallium occurs in trace amounts in bauxite (an aluminum ore) and zinc ores.
Gallium is most commonly used in the form of the compound gallium(III) arsenide, which is a semiconductor useful for integrated circuitslight-emitting diodes (LEDs), and laser diodes. The nitride and phosphide of gallium are also valuable semiconductor materials, and gallium itself is used as a dopant in semiconductors. In addition, this metal is a component in low-melting temperature alloys, and its alloy with indium and tin is used in medical thermometers to replace mercury. Also, gallium can wet (coat) glass to create brilliant mirrors.

Occurrence and isolation

Gallium does not exist in free form in nature, nor are there any gallium-rich minerals that might serve as primary sources of extraction of the element or its compounds. Rather, gallium is extracted as a trace component from bauxitecoal, diaspore, germanite, and sphalerite. Some flue dusts from burning coal have been shown to contain as much as 1.5 percent gallium.
Most gallium is extracted from the crude aluminum hydroxide solution of the Bayer process for producing alumina and aluminum. A mercury cell electrolysis and hydrolysisof the amalgam with sodium hydroxide leads to sodium gallate. Electrolysis then gives gallium metal. For semiconductor use, further purification is carried out using zone melting, or else single crystal extraction from a melt (Czochralski process). Purities of 99.9999 percent are routinely achieved and widely available commercially.

History

Before gallium was discovered, the element and many of its properties had been predicted and described by Dmitri Mendeleev, on the basis of its position in the periodic table. Mendeleev called the hypothetical element eka-aluminum.
In 1875, Lecoq de Boisbaudran discovered gallium by the technique known as spectroscopy. When examining a sample of zinc blende from the Pyrenees, he noticed two unique violet lines in its spectrum, indicative of a previously unknown element. Later, he obtained the free metal by the electrolysis of its hydroxide in KOH solution. He named the element "gallia" after his native land of France; also, in one of those multilingual puns so beloved of men of science of the early nineteenth century, he named it after himself—Lecoq means "the rooster" in French, and Latin for rooster is gallus.
31zinc ← gallium → germanium
Al

Ga

In
Ga-TableImage.png
General
NameSymbolNumbergallium, Ga, 31
Chemical seriespoor metals
GroupPeriod, Block13, 4, p
Appearancesilvery white
Typical (melted blob) Crystallized
Atomic mass69.723(1) g/mol
Electron configuration[Ar] 3d10 4s2 4p1
Electrons per shell2, 8, 18, 3
Physical properties
Phasesolid
Density (near r.t.)5.91 g/cm³
Liquid density at m.p.6.095 g/cm³
Melting point302.9146 K
(29.7646 °C, 85.5763 °F)
Boiling point2477 K
(2204 °C, 3999 °F)
Heat of fusion5.59 kJ/mol
Heat of vaporization254 kJ/mol
Heat capacity(25 °C) 25.86 J/(mol·K)
Vapor pressure
P/Pa1101001 k10 k100 k
at T/K131014481620183821252518
Atomic properties
Crystal structureorthorhombic
Oxidation states3
(amphoteric oxide)
Electronegativity1.81 (Pauling scale)
Ionization energies
(more)
1st: 578.8 kJ/mol
2nd: 1979.3 kJ/mol
3rd: 2963 kJ/mol
Atomic radius130 pm
Atomic radius (calc.)136 pm
Covalent radius126 pm
Van der Waals radius187 pm
Miscellaneous
Magnetic orderingno data
Thermal conductivity(300 K) 40.6 W/(m·K)
Speed of sound (thin rod)(20 °C) 2740 m/s
Mohs hardness1.5
Brinell hardness60 MPa
CAS registry number7440-55-3
Notable isotopes
Main article: Isotopes of gallium
isoNAhalf-lifeDMDE (MeV)DP
69Ga60.11%Ga is stable with 38 neutrons
71Ga39.89%Ga is stable with 40 neutrons

Notable characteristics


Very pure gallium metal has a brilliant silvery color.
In the periodic table, gallium lies in group 13 (former group 3A), between aluminum and indium, and in the same group as thallium. Consequently, its properties resemble those of these three elements. In addition, it is situated in period 4, between zinc and germanium. It is also said to be one of the "poor metals"—elements located between the transition metals and metalloids in the periodic table.
High-purity, metallic gallium has a brilliant, silvery color. By contrast, like most metals, finely divided gallium loses its luster—powdered gallium appears gray. The solid form fractures conchoidally, like glass. When liquid gallium solidifies, it expands by 3.1 percent. Thus, its liquid state has a higher density than the solid state—a property characteristic of only a few materials like water and bismuth. Also, given the property of expansion during solidification, gallium is not stored in either glass or metal containers to prevent the container from rupturing when the element freezes.
Gallium also diffuses into the crystal lattice of most other metals. This is another reason why it is important to keep gallium away from metal containers such as steel or aluminum. Gallium easily alloys with many other metals, and it was used in small quantities in the core of the first atomic bomb to help stabilize the plutonium crystal structure.
Given its melting point of 30°C, the metal readily melts in the hand. Also, the liquid form has a strong tendency to supercool below its melting point, and it needs to be seeded for solidification to begin. Gallium is one of the metals—along with cesiumfrancium, and mercury)—that is liquid at or near normal room temperature. It can therefore be used in metal-in-glass high-temperature thermometers. It is also notable for having one of the largest liquid ranges for a metal, and (unlike mercury) for having a low vapor pressure at high temperatures.
Unlike mercury, liquid gallium wets (coats) glass and skin, making it mechanically more difficult to handle, although it is substantially less toxic and requires far fewer precautions. For this reason, as well as the metal contamination and freezing expansion problems noted above, samples of gallium metal are usually supplied in polyethylene packets within other containers.
Gallium does not crystallize into any of the simple crystal structures. The stable phase under normal conditions is orthorhombic, with eight atoms in the conventional unit cell. Each atom has only one nearest neighbor (at a distance of 244 picometers) and six other neighbors within an additional 39-picometer radius. The bonding between nearest neighbors has covalent character. Also, the element has many stable and metastable phases, depending on the temperature and pressure conditions.
High-purity gallium is attacked slowly by mineral acids.

Isotopes

Many isotopes of gallium are known, ranging from 56Ga to 86Ga. Among them, there are two stable isotopes69Ga and 71Ga, at relative abundances estimated at 60.11 percent and 39.89 percent, respectively. The radioisotopes, by contrast, have extremely short half-lives.

Compounds

Gallium can form a number of compounds. Some of them are mentioned below.
  • Gallium(III) arsenide (GaAs): It is an important semiconductor, used for such devices as microwave-frequency integrated circuits (Monolithic Microwave Integrated Circuits, or MMICs), infrared light-emitting diodes (LEDs), laser diodes, and solar cells. Some of its electronic properties are superior to those of silicon. For instance, GaAs devices can function at higher frequencies (above 250 gigahertz), generating less noise, and can be operated at higher power levels. Also, they have a direct band gap, so they can be used to emit light.
  • Gallium(III) hydroxide (Ga(OH)3): This is the normal mineral form of gallium in the Earth's crust. It does not occur as a discrete mineral, but gallium replaces aluminum in ores such as bauxite. Gallium hydroxide isamphoteric, that is, it can behave as an acid as well as a base. In strongly acidic conditions, the ion Ga3+ is formed; in strongly basic conditions, Ga(OH)4-, is formed.
  • Gallium(III) nitride (GaN): This hard, mechanically stable material is a binary semiconductor with a wide, direct band gap. It is used in optoelectronic devices such as high-brightness, blue LEDs and blue laser diodes. Its sensitivity to ionizing radiation is low, making it a suitable material for solar cell arrays for satellites. It is being investigated for use in high-frequency, high-power transistors that can operate at high temperatures.
  • Gallium(III) phosphide (GaP): This solid, crystalline material has the appearance of pale orange pieces. It is odorless and insoluble in water, and it melts at 1,480°C. It is a semiconductor with an indirect band gap (2.26 electronvolt). Sulfur or tellurium may be added as dopants to turn gallium phosphide into an n-type semiconductor; or zinc may be added as a dopant to prepare a p-type semiconductor. GaP is used for the manufacture of low- and standard-brightness red, orange, and green LEDs.

Applications

Gallium, its alloys, and its compounds have many applications. Some of them are listed below.
  • The most common applications of gallium are in the form of the semiconductor gallium(III) arsenide. This compound is used mainly for analog integrated circuits, and also for optoelectronic devices such as LEDs and laser diodes.
  • Gallium is widely used as a dopant in semiconductors, to produce solid-state devices such as transistors.
  • Given that gallium can wet glass or porcelain, it can be used to create brilliant mirrors.
  • Gallium readily alloys with most metals, and has been used as a component in low-melting alloys.
  • The plutonium used in nuclear weapon pits is machined by alloying with gallium to stabilize the allotropes of plutonium.
  • When added in quantities up to 2 percent in common solders, gallium can aid wetting and flow characteristics.
  • Gallium is used in some high-temperature thermometers.
  • An alloy of gallium, indium, and tin (trade name Galinstan) is widely available in medical thermometers (fever thermometers), replacing problematic mercury. This alloy has a freezing point of −20°C.
  • Magnesium gallate, containing impurities such as Mn+2, is beginning to be used in ultraviolet-activated phosphor powder.
  • Gallium salts, such as gallium citrate or gallium nitrate containing a radioactive isotope of gallium, have been used in nuclear medicine imaging. This use, however, has largely been replaced by FDG PET scans.
  • Much research is being devoted to gallium alloys as substitutes for mercury dental amalgams, but such compounds have yet to gain wide acceptance.
  • Gallium is the rarest component of new photovoltaic compounds (such as copper indium gallium selenium sulphide or Cu(In,Ga)(Se,S)2, announced by South African researchers) for use in solar panels as an alternative to crystalline silicon, which is currently in short supply.
  • It has been suggested that a liquid gallium-tin alloy could be used to cool computer chips in place of water. As it conducts heat approximately 65 times better than water, it can make a comparable coolant.[1]

Precautions

Gallium is not considered toxic, but the data about its effects are inconclusive. Some sources suggest that it may cause dermatitis from prolonged exposure; other tests have not caused a positive reaction. When the element is handled with bare hands, the skin acquires a gray stain from an extremely fine dispersion of liquid gallium droplets.

Credits

New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License(CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here.
Note: Some restrictions may apply to use of individual images which are separately licensed.