Atom Re40

[Sandra Grady]

Thispack has few load assisting features and, as such, is only intended to be used by those with dialled in gear lists who like to enjoy the freedom of a light pack and moving without a frame or hip belt.

Side pockets

Two 2.5L forward-facing, deep and low side pockets made with 210D Robic Extreema. Each one is big enough to keep 2 x 1L Smartwater bottles steady, yet low enough to reach whilst the pack is worn.

Side elastic with Lineloc

These are there to secure a pole or tent stakes when stored in the side pocket. If you are wanting to compress the bag, we recommend switching to a non-stretch cord.

My first Atom Pack. I bought this pack 2 months ago to help reduce my spring/summer pack weight and have been nothing but blown away by the detail and thought of the design. Currently in the process of purchasing a custom MO60 for winter and i know ill be impressed yet again. Added bonus to be able to support another great UK maker. Thank you Atom Packs

Too many of the other ultralight products I've purchased recently just haven't been durable enough to justify buying and using. I've used the 35L atom on many trips now and it's blowing everything else out of the water. It's been in the desert, swamp, and mountains and it's my favorite piece of gear.

The wide shoulder straps are not noticeable until you go back to a pack that has smaller ones. Then you will miss the wider straps. The pack itself is pretty narrow; narrower than I thought it would be, but it can still fit the smaller, blue bear canister in any orientation. The bottom pocket works well too.

Rhenium was originally discovered by Masataka Ogawa in 1908, but he mistakenly assigned it as element 43 rather than element 75 and named it nipponium. It was rediscovered by Walter Noddack, Ida Tacke and Otto Berg in 1925,[8] who gave it its present name. It was named after the river Rhine in Europe, from which the earliest samples had been obtained and worked commercially.[9]

Nickel-based superalloys of rhenium are used in combustion chambers, turbine blades, and exhaust nozzles of jet engines. These alloys contain up to 6% rhenium, making jet engine construction the largest single use for the element. The second-most important use is as a catalyst: it is an excellent catalyst for hydrogenation and isomerization, and is used for example in catalytic reforming of naphtha for use in gasoline (rheniforming process). Because of the low availability relative to demand, it is expensive, with price reaching an all-time high in 2008/2009 of US$10,600 per kilogram (US$4,800 per pound). Due to increases in recycling and a drop in demand for rhenium in catalysts, the price had dropped to US$2,844 per kilogram (US$1,290 per pound) as of July 2018.[10]

In 1908, Japanese chemist Masataka Ogawa announced that he had discovered the 43rd element and named it nipponium (Np) after Japan (Nippon in Japanese). In fact, he had found element 75 (rhenium) instead of element 43: both elements are in the same group of the periodic table.[11][12] Ogawa's work was often incorrectly cited, because some of his key results were published only in Japanese; it is likely that his insistence on searching for element 43 prevented him from considering that he might have found element 75 instead. Just before Ogawa's death in 1930, Kenjiro Kimura analysed Ogawa's sample by X-ray spectroscopy at the Imperial University of Tokyo, and said to a friend that "it was beautiful rhenium indeed". He did not reveal this publicly, because under the Japanese university culture before World War II it was frowned upon to point out the mistakes of one's seniors, but the evidence became known to some Japanese news media regardless. As time passed with no repetitions of the experiments or new work on nipponium, Ogawa's claim faded away.[12] The symbol Np was later used for the element neptunium, and the name "nihonium", also named after Japan, along with symbol Nh, was later used for element 113. Element 113 was also discovered by a team of Japanese scientists and was named in respectful homage to Ogawa's work.[13] Today, Ogawa's claim is widely accepted as having been the discovery of element 75 in hindsight.[12]

Rhenium (Latin: Rhenus meaning: "Rhine")[14] received its current name when it was rediscovered by Walter Noddack, Ida Noddack, and Otto Berg in Germany. In 1925 they reported that they had detected the element in platinum ore and in the mineral columbite. They also found rhenium in gadolinite and molybdenite.[15] In 1928 they were able to extract 1 g of the element by processing 660 kg of molybdenite.[16] It was estimated in 1968 that 75% of the rhenium metal in the United States was used for research and the development of refractory metal alloys. It took several years from that point before the superalloys became widely used.[17][18]

The original mischaracterization by Ogawa in 1908 and final work in 1925 makes rhenium perhaps the last stable element to be understood. Hafnium was discovered in 1923[19] and all other new elements discovered since then, such as francium, are radioactive.[20]

Rhenium is a silvery-white metal with one of the highest melting points of all elements, exceeded by only tungsten. (At standard pressure carbon sublimes rather than melts, though its sublimation point is comparable to the melting points of tungsten and rhenium.) It also has one of the highest boiling points of all elements, and the highest among stable elements. It is also one of the densest, exceeded only by platinum, iridium and osmium. Rhenium has a hexagonal close-packed crystal structure.

In bulk form and at room temperature and atmospheric pressure, the element resists alkalis, sulfuric acid, hydrochloric acid, nitric acid, and aqua regia. It will however, react with nitric acid upon heating.[25]

The most common oxide is the volatile yellow Re2O7. The red rhenium trioxide ReO3 adopts a perovskite-like structure. Other oxides include Re2O5, ReO2, and Re2O3.[33] The sulfides are ReS2 and Re2S7. Perrhenate salts can be converted to tetrathioperrhenate by the action of ammonium hydrosulfide.[34]

Methylrhenium trioxide ("MTO"), CH3ReO3 is a volatile, colourless solid has been used as a catalyst in some laboratory experiments. It can be prepared by many routes, a typical method is the reaction of Re2O7 and tetramethyltin:

Analogous alkyl and aryl derivatives are known. MTO catalyses for the oxidations with hydrogen peroxide. Terminal alkynes yield the corresponding acid or ester, internal alkynes yield diketones, and alkenes give epoxides. MTO also catalyses the conversion of aldehydes and diazoalkanes into an alkene.[39]

The nickel-based superalloys have improved creep strength with the addition of rhenium. The alloys normally contain 3% or 6% of rhenium.[55] Second-generation alloys contain 3%; these alloys were used in the engines for the F-15 and F-16, whereas the newer single-crystal third-generation alloys contain 6% of rhenium; they are used in the F-22 and F-35 engines.[54][56] Rhenium is also used in the superalloys, such as CMSX-4 (2nd gen) and CMSX-10 (3rd gen) that are used in industrial gas turbine engines like the GE 7FA. Rhenium can cause superalloys to become microstructurally unstable, forming undesirable topologically close packed (TCP) phases. In 4th- and 5th-generation superalloys, ruthenium is used to avoid this effect. Among others the new superalloys are EPM-102 (with 3% Ru) and TMS-162 (with 6% Ru),[57] as well as TMS-138[58] and TMS-174.[59][60]

For 2006, the consumption is given as 28% for General Electric, 28% Rolls-Royce plc and 12% Pratt & Whitney, all for superalloys, whereas the use for catalysts only accounts for 14% and the remaining applications use 18%.[53] In 2006, 77% of rhenium consumption in the United States was in alloys.[54] The rising demand for military jet engines and the constant supply made it necessary to develop superalloys with a lower rhenium content. For example, the newer CFM International CFM56 high-pressure turbine (HPT) blades will use Rene N515 with a rhenium content of 1.5% instead of Rene N5 with 3%.[61][62]

Rhenium improves the properties of tungsten. Tungsten-rhenium alloys are more ductile at low temperature, allowing them to be more easily machined. The high-temperature stability is also improved. The effect increases with the rhenium concentration, and therefore tungsten alloys are produced with up to 27% of Re, which is the solubility limit.[63] Tungsten-rhenium wire was originally created in efforts to develop a wire that was more ductile after recrystallization. This allows the wire to meet specific performance objectives, including superior vibration resistance, improved ductility, and higher resistivity.[64] One application for the tungsten-rhenium alloys is X-ray sources. The high melting point of both elements, together with their high atomic mass, makes them stable against the prolonged electron impact.[65] Rhenium tungsten alloys are also applied as thermocouples to measure temperatures up to 2200 C.[66]

Rhenium has a high melting point and a low vapor pressure similar to tantalum and tungsten. Therefore, rhenium filaments exhibit a higher stability if the filament is operated not in vacuum, but in oxygen-containing atmosphere.[67] Those filaments are widely used in mass spectrometers, ion gauges[68] and photoflash lamps in photography.[69]

Rhenium in the form of rhenium-platinum alloy is used as catalyst for catalytic reforming, which is a chemical process to convert petroleum refinery naphthas with low octane ratings into high-octane liquid products. Worldwide, 30% of catalysts used for this process contain rhenium.[70] The olefin metathesis is the other reaction for which rhenium is used as catalyst. Normally Re2O7 on alumina is used for this process.[71] Rhenium catalysts are very resistant to chemical poisoning from nitrogen, sulfur and phosphorus, and so are used in certain kinds of hydrogenation reactions.[21][72][73]

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