scholarly journals A NEW FORM OF DIFFERENTIAL MICRORESPIROMETER

1940 ◽  
Vol 24 (2) ◽  
pp. 135-149 ◽  
Author(s):  
Burris Cunningham ◽  
Paul L. Kirk
Keyword(s):  
Room Temperature ◽  
Gas Mixture ◽  
Chamber Volume ◽  
Capillary Tubing ◽  
New Form ◽  
Entire Apparatus

1. A microrespirometer suitable for measuring oxygen uptakes from 0.1 to 10λ per hour is described. 2. The sensitivity of the instrument may be readily altered by substituting different sizes of capillary tubing. 3. By means of replaceable brass plugs the chamber volume of this instrument may be varied from 700 to less than 40λ. 4. No thermostat is required for the operation of the instrument at room temperature. 5. It may be charged at one temperature and used at a widely different one. 6. The chambers may be filled with any desired gas mixture. 7. Two solutions may be mixed during the course of an experiment. 8. The entire apparatus may be sterilized.

scholarly journals The sorption of hydrogen on copper. Part II.—The rate of solution

1931 ◽  
Vol 133 (822) ◽  
pp. 522-535 ◽  
Keyword(s):  
Room Temperature ◽  
Thermal Capacity ◽  
Mercury Surface ◽  
Nichrome Wire ◽  
Boiling Points ◽  
Spark Gap ◽  
Capillary Tubing ◽  
Alumel Thermocouple ◽  
Adsorption Of Gases ◽  
Iron Tube

Before attention was directed to the adsorption of gases on the surfaces of solids much work was done on the “occlusion” at higher temperatures. Above 400° C. solution usually occurs rapidly, and because of the decrease in surface by sintering, the adsorption is negligible compared with the absorption. In this paper, investigations on the sorption of hydrogen on copper are described at temperatures intermediate between 25° C. when adsorption is the principal phenomenon and 200° C. when solution has become important. Over this range of temperature both adsorption and absorption have been measured. On bringing the hydrogen into contact with the copper there was always an immediate fall in pressure attributable to adsorption, followed by a slower fall as absorption proceeded. This latter process, of course, became quicker at higher temperatures. Experimental . Apparatus .—The apparatus used was almost exactly the same as that described in the previous paper. The only difference was that instead of the thermostat at 25° C. a furnace was used. A copper tube about 50 cm. long and 5 cm. in diameter, wound with nichrome wire, had placed inside it, for half its length, a tightly fitting iron tube with thick walls (1 cm.). The adsorption bulb went into this half, and the low conductivity and large thermal capacity of the iron hindered fluctuations in temperature from reaching the bulb. In the lower half of the furnace, where the absence of the iron tube allowed the temperature to vary promptly with a changed heating current, was a thermoregulator bulb containing air, connected by capillary tubing to a U-tube in which mercury made contact with a tungsten point. On the other side of the U-tube a system of the same volume, with a bulb immersed in a thermostat, counteracted the effect of alterations of room temperature. An extra U-tube of mercury enclosed nitrogen around the spark gap to prevent dirtying the mercury surface by oxidation. With this arrangement the temperature could be kept constant to within half a degree for any length of time. Temperatures were measured by a chromel-alumel thermocouple calibrated at the boiling points of suitable liquids.

Epoxidized Natural Rubber

1985 ◽  
Vol 58 (1) ◽  
pp. 67-85 ◽  
Author(s):  
C. S. L. Baker ◽  
I. R. Gelling ◽  
R. Newell
Keyword(s):  
Natural Rubber ◽  
Room Temperature ◽  
Unique Feature ◽  
Gas Permeability ◽  
Rolling Resistance ◽  
Truck Tire ◽  
Coupling Reagent ◽  
Automotive Parts ◽  
New Form ◽  
Wet Grip

Abstract When natural rubber is epoxidized under carefully controlled conditions, it can be converted to a totally new polymer with some properties more akin to speciality rubbers and some properties that appear to be advantageous for tire treads. Three levels of epoxidation have been extensively evaluated. They were 50, 25 and 10 mole% epoxidized NR referred to as ENR-50, ENR-25 and ENR-10 respectively. ENR-50 has been found to undergo strain crystallization like NR, but with oil resistance similar to a medium acrylonitrile NBR and gas permeability similar to butyl rubber. It is a highly damping rubber with a very low room-temperature resilience. ENR-50 and ENR-25 both exhibit good wet grip characteristics and have been examined as tire tread materials. In particular, ENR-25 compounds containing silica or silica/black have been found to give lower rolling resistance than NR and better wet traction than OESBR, so providing an ideal combination of these two properties for tire treads. Unfortunately, wear data is as yet incomplete, but it is anticipated, from truck tire experience, that the black/silica compounds will present no problems. ENR-25 and ENR-50 exhibit this unique feature with silica of reinforcement equivalent to black without the use of a coupling reagent. Thus, these rubbers have potential of providing white or colored vulcanizates with properties previously associated only with black-filled compounds, so extending applicational areas, or even resulting in colored tires or other automotive parts. ENR-10 provides a damping grade of NR when lower resiliences are required. Alternatively, blends of ENR-25 or -50 with NR may be used. Many engineering applications are calling for reduced resilience, and this new form of NR can give precisely this.

scholarly journals On a new form of reagent against perspiration effects on shoe materials

1945 ◽  
Vol 44 (1) ◽  
pp. 53-55 ◽  
Author(s):  
A. Colin-Russ
Keyword(s):  
Salt Solution ◽  
Room Temperature ◽  
Ammonium Acetate ◽  
Common Salt ◽  
Cotton Yarn ◽  
Precise Data ◽  
White Cotton ◽  
New Form ◽  
Dry Out ◽  
Aqueous Ammonium Acetate

In a discussion of a series of tests connected with the fastness of colours on textile fibres, Villavecchia (1918) mentions the use of neutral ammonium acetate or common salt solution for measuring the colour resistance to perspiration. Thus in the case of coloured cotton, this is immersed for 10 min. alongside an equal quantity of white cotton yarn in a 0·1% aqueous ammonium acetate at 80°C., and the extent of colouring of the yarn as well as the degree of stripping of the coloured sample noted after drying without rinsing. An odd number of degrees of fastness is arbitrarily assigned to the coloured specimen according to the result, e.g. V degrees if neither the original tint nor the whiteness of the yarn is changed. Similarly with linen, hemp and ramie. For coloured wool both methods are used, viz. with sodium chloride and with ammonium acetate. In the former case, the alteration in colour is noted after simply dipping the wool in salt solution and allowing to air-dry out at room temperature. In the latter case, an equal quantity of white zephyr wool in addition to the white cotton is present. V degrees in all cases are stated to be conventionally adopted between industrial associations and dyestuff manufacturers for materials which are fast enough to reveal no change whatever in the testing bath. For coloured silk there are no precise data, and usually it is immersed in distilled water for several days to ascertain if any colour is lost.

Stable Visible Photoluminescence from Annealed Polysiloxene-Based Thin Films

1995 ◽  
Vol 417 ◽  
Author(s):  
S. Miyazaki ◽  
A. Mouraguchi ◽  
M. Shinohara
Keyword(s):  
Thin Films ◽  
Steady State ◽  
Substrate Temperature ◽  
Radiative Recombination ◽  
Room Temperature ◽  
Excitation Power ◽  
Localized States ◽  
Gas Mixture ◽  
Plasma Enhanced Cvd ◽  
Visible Luminescence

AbstractPolysiloxene-based films have been prepared by plasma enhanced CVD in a Si2H6+O2 gas mixture at a substrate temperature of −110°C and annealed at temperatures from 700°C to 1000°C. It is found that the film annealed at 1000°C is composed of 1∼5nm Si crystallites embedded in SiO2 and exhibits stable, intense visible-luminescence at room temperature under 488nm excitation. The temperature and excitation power dependences of the steady-state and timeresolved luminescence of the annealed films suggest the radiative recombination through localized states in the Si/SiO2 interface region.

Lewis-Base Adducts of Group 11 Metal(I) Compounds. LXVIII Synthesis and Structural Systematics of Some 1 : 3 Adducts of Silver(I) Compounds with Triphenylstibine, [(Ph3Sb)3AgX], X = Cl, I, SCN, NCS, CN, ONO2

1997 ◽  
Vol 50 (6) ◽  
pp. 587 ◽  
Author(s):  
Effendy ◽  
John D. Kildea ◽  
Allan H. White
Keyword(s):  
Single Crystal ◽  
Structural Characterization ◽  
Room Temperature ◽  
Lewis Base ◽  
Nitrate Complex ◽  
X Ray ◽  
Ethanol Solvate ◽  
New Form ◽  
Pseudo Halides

The syntheses and room-temperature single-crystal X-ray structural characterization of 1 : 3 adducts formed between silver(I) (pseudo-) halides, AgX, and triphenylstibine, SbPh3, are described for X = Cl, I, SCN, NCS, CN, NO3 (1)-(6). The chloride, as its methanol solvate (1a), is isomorphous with the arsine analogue: triclinic, P-1, a 13·373(4), b 14·48(6), c 14·702(3) Å, α 83·49(3), β 87·76(2), γ 76·45(3)°; Z = 2, conventional R on F being 0·046 for No 5514 independent ‘observed’ reflections (I > 3σ(I )). A new form (1b) of the chloride has also been authenticated: monoclinic, P 21/c, a 12·832(2), b 54·24(1), c 18·519(8) Å, β 129·68(3)°; Z = 8 (R 0·065 for No 5672). No bromide has been obtained; the iodide (2) is described as monoclinic, P 21/n, a 19·611(4), b 14·473(6), c 17·74(1) Å, β 98·28(3)°; Z = 4 (R 0·036 for No 6769). The thiocyanate crystallizes from acetonitrile or pyridine as an S-bonded form (3) isomorphous with the arsine analogue: monoclinic, P 21/n, a 19·143(7), b 14·288(5), c 18·694(6) Å, β 98·81(2)°; Z = 4 (R 0·037 for No 4482). From 2-methylpyridine, remarkably, a solvate is obtained in which the thiocyanate is N-bonded (4): triclinic, P-1, a 27·261(5), b 14·767(3), c 13·319(1) Å, α 91·53(1), β 101·58(1), γ 92·29(2)°; Z = 4 (R 0·045 for No 6900). The cyanide is also monoclinic, P 21/n, a 19·442(7), b 14·267(3), c 17·741(6) Å, β 97·63(3)°, z = 4; R 0·057 for No 2487. The unsolvated 1 : 3 nitrate complex (6a) is monoclinic, P 21/n, a 19·602(5), b 14·455(1), c 17·727(2) Å, β 97·19(2)°, Z = 4; R was 0·034 for No 6522. The complex is isomorphous with the arsenic and phosphorus analogues, being mononuclear [(Ph3Sb)3Ag(O2NO)]. The ethanol solvate (6b) is triclinic, P-1, a 13·352(5), b 14·548(9), c 14·701(4) Å, α 81·64(4), β 84·45(3), γ 75·32(4)°, Z = 2; R was 0·058 for No 4702. Ag-Sb range between 2·6980(8) and 2·843(3) Å in the precise determinations; Ag-X are 2·481(4) and 2·52(1) Å (the two chlorides), 2·757(1) (I), 2·533(3) (SCN), 2·21(1) (NCS), 2· 09(3) (CN), 2·377(7) Å (unidentate ONO2)

scholarly journals Селективные сенсоры двуокиси азота на основе тонких пленок оксида вольфрама при воздействии оптического излучения

2019 ◽  
Vol 45 (20) ◽  
pp. 7
Author(s):  
А.В. Алмаев ◽  
Н.Н. Яковлев ◽  
Е.В. Черников ◽  
О.П. Толбанов
Keyword(s):  
Room Temperature ◽  
Response Times ◽  
Sensor Response ◽  
Maximum Intensity ◽  
Gas Mixture ◽  
Selective Detection ◽  
High Humidity ◽  
Near Surface ◽  
Order Of Magnitude ◽  
Reducing Gases

The possibility of selective detection of NO2 in the air starting with a concentration of 1 ppm by means of sensors based on thin films of Au/WO3:Au when replacing the heating by the irradiation of the diode with the wavelength of 400 nm of maximum intensity of radiation is shown. Activation of photodesorption by irradiation reduces the response times of sensors under the influence of NO2 by an order of magnitude. It was found that the effect of high humidity in the conditions of irradiation of sensors at room temperature leads to an increase in response to NO2, due to the appearance of additional adsorption centers. The lack of sensor response to reducing gases and the change in the oxygen concentration in the gas mixture is caused by photodesorption of chemisorbed O2- when interacting with holes that generated under exposure of irradiation in the near-surface area of WO3.

Fabrication of Patterned Ferromagnetic Shape Memory Thin Films

2015 ◽  
Vol 644 ◽  
pp. 219-222
Author(s):  
P. Álvarez-Alonso ◽  
A. Pérez-Checa ◽  
I.R. Aseguinolaza ◽  
J. Alonso ◽  
A.V. Svalov ◽  
...  
Keyword(s):  
Shape Memory ◽  
Room Temperature ◽  
Film Deposition ◽  
Gas Mixture ◽  
Si Substrate ◽  
Polystyrene Spheres ◽  
Large Area ◽  
Coating Method ◽  
2D Arrays ◽  
Ferromagnetic Shape Memory

We report two possible routes of fabrication of large surfaces of ferromagnetic shape memory antidots with tunable pore size and center-to-center distances. By using the drop coating method, we have prepared a large area of 2D arrays (typically 1cm2) of polystyrene spheres (PS) (1.4±0.1μm diameter) on a Si substrate. We have used reactive ion etching with a gas mixture of O2(12sccm) and Ar (5sccm) to reduce the diameter of the PS spheres whereby controlling the size of pores. The film deposition was performed on a substrate heated at 500oC (route 1) and at room temperature with subsequent annealing in a furnace at 500oC for 4 hours (route 2). Route 1 proved to be promising but more work is needed to optimize it. The antidots of Ni-Mn-Ga obtained along route 2 are ferromagnetic with a Curie temperature ~100oC, and a spread martensitic transformation (between-100oC and-30oC).

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