SAR

Choosing a smartphone, and then we focus on its technical and cost characteristics. And hardly anyone pays attention to the fact, what level of radiation has a particular model. World found some harmless modern smartphones.

Radiation level of mobile devices are usually denoted acronym SAR. SAR (Specific Absorption Rate) – is the specific absorption coefficient of the human body of electromagnetic radiation emitted by mobile phone. SAR is the unit of measurement of watts / kilogram. To mobile phone received a certificate of conformity of an organization, depending on the country of production, it must meet certain standards. In the U.S., certification by Federal Communications Commission and Communications (FCC), in Canada this procedure by the Ministry of Industry (IC). These countries have adopted the norm value up to 1.6 W / kg per 1 gram of tissue mass. In countries outside the European Union, the rate of SAR is 2 W / kg, but the calculation is made on 10 grams of tissue.

lowest level of radiation

Typically, parameter SAR neglected. Shops and online sites in the description of a particular model indicate all options except this one. And all because of that finding, what level of SAR, is not so simple. So, if the models of Samsung and Nokia easier (their SAR can be found on the official website or through the technical support service), other manufacturers specify this option only in the manual, which is issued when buying a smartphone. Having dealt with the fact that a SAR, as it is measured, and that affects its level, we wanted to find out which one on the market today is the apparatus `harmless` and compiled a rating.

The first hand-held cell phone was demonstrated by John F. Mitchell and Dr. Martin Cooper of Motorola in 1973, using a handset weighing around 4.4 pounds (2 kg). In 1983, the DynaTAC 8000x was the first to be commercially available. From 1983 to 2014, worldwide mobile phone subscriptions grew from zero to over 7 billion, penetrating 100% of the global population and reaching the bottom of the economic pyramid. In 2014, the top cell phone manufacturers were Samsung, Nokia, Apple, and LG and Sony.

Osmium

Osmium is a hard but brittle metal that remains lustrous even at high temperatures. It has a very low compressibility. Correspondingly, its bulk modulus is extremely high, reported between 395 and 462 GPa  (gigapascals -kN/mm2), which rivals that of diamond (443 GPa). The hardness of osmium is moderately high at 4 GPa.Because of its hardness, brittleness, low vapor pressure (the lowest of the platinum group metals), and very high melting point (the fourth highest of all elements), solid osmium is difficult to machine, form, or work.Osmium has a blue-gray tint and is the densest stable element, slightly denser than iridium.Calculations of density from the X-ray diffraction data may produce the most reliable data for these elements, giving a value of 22.562±0.009 g/cm3 for iridium versus 22.587±0.009 g/cm3 for osmium.Osmium was discovered in 1803 by Smithson Tennant and William Hyde Wollaston in London, England.The discovery of osmium is intertwined with that of platinum and the other metals of the platinum group.Osmium (from Greek osme meaning "smell") is a chemical element with symbol Os and atomic number 76.  Its alloys with platinum, iridium, and other platinum group metals are employed in fountain pen nibs, electrical contacts, and other applications where extreme durability and hardness are needed.Osmium is the least abundant stable element in Earth's crust with an average mass fraction of 50 parts per trillion in the continental crust.Within Earth's crust, osmium, like iridium, is found at highest concentrations in three types of geologic structure: igneous deposits (crustal intrusions from below), impact craters, and deposits reworked from one of the former structures. The largest known primary reserves are in the Bushveld igneous complex in South Africa,though the large copper–nickel deposits near Norilsk in Russia, and the Sudbury Basin in Canada are also significant sources of osmium. Smaller reserves can be found in the United States. Osmium tetroxide has been used in fingerprint detection and in staining fatty tissue for optical and electron microscopy. In 1898 an Austrian chemist, Auer von Welsbach, developed the Oslamp with a filament made of osmium, which he introduced commercially in 1902.The only known clinical use of osmium appears to be for synovectomy in arthritic patients in Scandinavia. It involves the local administration of osmium tetroxide (OsO4) which is a highly toxic compound. The lack of reports of long-term side effects suggest that osmium itself can be biocompatible, although this depends on the osmium compound administered. In 2011, osmium(VI)and osmium(II) compounds were reported to show anti cancer activity in vivo, it indicated a promising future for using osmium compounds as anti cancer drugs. Osmium is usually sold as a minimum 99.9% pure powder. Like other precious metals, it is measured by troy weight and by grams.

Its price in 2012 was about $400 per troy ounce (or about $13,000 per kilogram), depending on the quantity and its supplier.Osmium is one of the heaviest elements known; it is twice as heavy as lead and 22 times as heavy as water. It is also the least compressible material known. Osmium is a member of the platinum family of metals and is found in ores containing platinum. Osmium tetroxide, the most important osmium compound, is a powerful oxidizing agent. It is used to harden and stain microscope slides of biological specimens, and plays an important role in the synthesis of certain organic compounds, including cortisone. Osmium was discovered in 1804 by Smithson Tennant, a British chemist. Osmium metal remained as a residue when he dissolved crude platinum in aqua regia (a mixture of nitric and hydrochloric acids). 

The name osmium is derived from osme, the Greek word for smell, in recognition of the strong, chlorinelike odor of osmium tetroxide.osmium Symbol: Os. Atomic number: 76. Atomic weight: 190.2. Specific gravity: 22.57. Hardness: 7.0. Melting point: about 5,520 F. (3,050 C.). Boiling point: about 9,000 F. (5,000 C.). Osmium has seven stable isotopes: Os-184, Os-186 through 190, and Os-192. It belongs to Group VIII of the Periodic Table, and its principal valences are +3, +4, +6, and +8.A vest made of osmium would be extremely expensive, pricing in at around $100/gram.

The ultimate success of the humanity

Kawasaki disease

Rarest of the rare disease..The `Kawasaki disease` (mucocutaneous lymph node syndrome) is a form of vasculitis identified by an acute febrile illness with multiple systems affected. The cause is unknown, but autoimmunity, infection, and genetic predisposition are believed to be involved. It affects mostly children between ages 3 months and 8 years; 80% are younger than age 5. It occurs more commonly in Japanese children or those of Japanese decent. It has seasonal epidemics, usually in late winter and early spring. It was first described in 1967 by Dr. Tomisaku Kawasaki in Japan.Although Kawasaki disease is a multisystem disease, the cardiovascular system appears to be the primary site with coronary artery vasculitis, aneurysm development, thrombosis, and myocardial thrombosis progressing over days to weeks. Kawasaki disease is diagnosed off the presence of symptoms rather than the results of tests. Symptoms include: conjunctivitis, rash, adenopathy, strawberry tongue, and rash on palms and soles of hands and feet. Four of these symptoms must be present, in addition to a fever which has lasted more than 5 days to confirm a diagnosis. Learn about atypical Kawasaki disease, and how health professional treat the disease using intravenous immunoglobulins (IVIG) and acetylsalicylic acid.Approximately 15% to 25% of patients develop cardiac complications (coronary thrombosis or rupture, myocardial infarction, heart failure, vasculitis of the aorta or peripheral arteries); however mortality is low.