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.

scholarly journals On the capacity for heat of water between the freezing and boiling points, together with a determination of the mechanical equivalent of heat in terms of the international electrical units.―Experiments by the continuous-flow method of calorimetry performed in the Macdonald Physical Laboratory of McGill University, Montreal

1901 ◽  
Vol 67 (435-441) ◽  
pp. 238-244 ◽  
Keyword(s):  
Specific Heat ◽  
Continuous Flow ◽  
Thermal Capacity ◽  
Boiling Points ◽  
Physical Laboratory ◽  
Complete Work ◽  
Different Temperatures ◽  
Mcgill University ◽  
Continuous Flow Method

At the Toronto meeting of the British Association in 1897, a new method of calorimetry was proposed by Professor Callendar and the author for the determination of the specific heat of a liquid in term of the international electrical units. At the Dover meeting ii September, 1899, some of the general results obtained with the method for water over a part of the range between 0° and 100 were communicated, with a general discussion of the bearing of the experiments to the work of other observers. In the present paper the author gives a summary of the complete work, in the case of water, to determine the thermal capacity at different temperatures between the freezing and boiling points.

scholarly journals The fine-structure of some lines in the visible region of the spectrum of thallium III

1930 ◽  
Vol 129 (809) ◽  
pp. 43-47 ◽  
Keyword(s):  
Fine Structure ◽  
Visible Region ◽  
Nuclear Moment ◽  
Nichrome Wire ◽  
Spark Gap ◽  
High Tension ◽  
In Series ◽  
The One ◽  
Theoretical Results ◽  
Line Classification

From a study of the fine-structure of some lines in the arc spectrum of thallium Schüler and Brück concluded that the nucleus of the thallium atom possessed a moment of momentum given by ½ h /2π and this value was confirmed by work on the first spark spectrum of the element. The value of the nuclear moment being known the structure of the lines in the second spark spectrum could be predicted and the present paper is the account of an investigation of a number of these lines which lie in the visible region, a comparison being drawn between the experimental and the theoretical results. The source of light used was similar to the one employed by McLennan, McLay and Crawford in the excitation of the first and second spark spectra of thallium for the purpose of line classification. It consisted of a quartz tube about 50 cm. long and 1½ cm. in diameter with a plain window in each end and provided with aluminium electrodes sealed into side tubes. The metal whose spectrum was to be studied was scattered along thé bottom of the tube and the tube evacuated. The metal was then vaporised by hear supplied by a coil of nichrome wire wound on the tube. This coil must be wound non-inductively or the desired excitation will not be obtained. The high tension across the terminals was produced by joining them in series with the secondary of a 30,000-volt transformer and a spark gap of about 1 c. m., a condenser being connected in parallel.

Temperature Dependence of the Diffusion of 1,2-Dichloroethane, 1,1,1-Trichloroethane, Trichloroethylene, and Tetrachloroethylene in Air

1971 ◽  
Vol 49 (11) ◽  
pp. 1965-1967 ◽  
Author(s):  
Harry Watts
Keyword(s):  
Temperature Dependence ◽  
Diffusion Coefficients ◽  
Room Temperature ◽  
Evaporation Method ◽  
Temperature Range ◽  
Boiling Points ◽  
Rate Of Evaporation

The diffusion coefficients in air of 1,1-dichloroethane, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene have been measured over a temperature range from room temperature to close to their boiling points by a rate of evaporation method.

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 Synthesis and Property Characterization of Ternary Laminar Zr2SB Ceramic

2021 ◽  
Author(s):  
Qiqiang Zhang ◽  
Shuai Fu ◽  
Detian Wan ◽  
Yiwang Bao ◽  
Qingguo Feng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Room Temperature ◽  
Thermal Capacity ◽  
Boron Powder ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Spark Plasma ◽  
Property Characterization

Abstract In this paper, Zr2SB ceramics with high relative density (99.03%) and high purity of 82.95 wt% (containing 8.96 wt% ZrB2 and 8.09 wt% zirconium) were successfully synthesized from ZrH2, sublimated sulfur and boron powder by spark plasma sintering at 1300 ℃. The reaction mechanism, microstructures, physical properties and mechanical properties of Zr2SB ceramic were systematically studied. The results show that Zr2SB was obtained by the reaction of zirconium sulfide, zirconium and boron, and ZrB2 coexisted in the sample as a symbiotic impurity phase. The average grain size of Zr2SB was 12.46 μm in length and 5.12 μm in width, and the mean grain sizes of ZrB2 and zirconium impurities were about 300 nm. In terms of physical properties, the measured thermal expansion coefficient was 7.64 × 10-6 K-1 from room temperature to 1200 ℃, and the thermal capacity and thermal conductivity at room temperature were 0.39 J·g−1·K−1 and 12.01 W∙m−1∙K−1, respectively. The room temperature electrical conductivity of Zr2SB ceramic was measured to be 1.74 × 106 Ω−1∙m−1. In terms of mechanical properties, Vickers hardness was 9.86 ± 0.63 GPa under 200 N load, and the measured flexural strength, fracture toughness and compressive strength were 269 ± 12.7 MPa, 3.94 ± 0.63 MPa·m1/2, and 2166.74 ± 291.34 MPa, respectively.

scholarly journals The oxidation of copper and the reactions of hydrogen and carbon monoxide with copper oxide

1949 ◽  
Vol 197 (1050) ◽  
pp. 294-314 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Cuprous Oxide ◽  
Room Temperature ◽  
Hydrogen Reduction ◽  
Metallic Copper ◽  
Conductivity Measurements ◽  
Heats Of Adsorption ◽  
Adsorption Of Gases ◽  
Conductivity Of Thin Films ◽  
Kinetics Of

An investigation has been made of the activation of copper by successive oxidation and reduction with hydrogen. Reduction with carbon monoxide causes deactivation of the surface. The heats of adsorption of carbon monoxide and oxygen and the heat liberated during the catalytic reaction of carbon monoxide and oxygen on a cuprous oxide film formed on metallic copper have been measured at room temperature. The kinetics of the reactions have been studied. The electrical conductivity of thin films of oxides has been measured during the reduction with hydrogen, and a study made of the process of embrittlement, whereby the surface is activated. The effect of the adsorption of gases on the conductivity of the Cu 2 O-CuO surface has been investigated. Oxygen enhances the conductivity and carbon monoxide and hydrogen depress it. The reaction between carbon monoxide and oxygen has been followed at room temperature by conductivity measurements and the results have been employed to interpret the nature of the adsorption, the kinetics of the reaction, and the deactivation of the surface by carbon monoxide.

Temperature of Food and Drink Intake Matters

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Kaufui Vincent Wong
Keyword(s):  
Room Temperature ◽  
Caloric Intake ◽  
Thermal Capacity ◽  
The Body ◽  
Effect Of Temperature ◽  
South Korean ◽  
Daily Diet ◽  
Food And Drink ◽  
Current Guidelines ◽  
Food Consumed

The U.S. Government determines the guidelines for daily diet of humans in their various life stages. The current guidelines for caloric intake are about 2800 cal daily for the adult male, and about 600 cal less for the adult female. This work brings up the point that with the growing diversity of the population, these caloric intake guidelines need to consider the effect of temperature at the time the food is consumed. The motivation of this study is diversity; it is recognized that the Chinese and South Korean cuisines typically have high temperatures when served, whereas much of standard American food is consumed at room temperature. The thermal capacity of the food consumed has not been taken into consideration. It is likely that the “empty” calories related to consumption of hot foods are helpful, in keeping the body warm without the risk of weight gain. They may also be used judiciously to lose weight.

Estimation of heats of vaporization for non associating organic liquids from the boiling points at various pressures

1986 ◽  
Vol 64 (4) ◽  
pp. 635-640 ◽  
Author(s):  
J. Peter Guthrie
Keyword(s):  
Heat Capacity ◽  
Vapor Pressure ◽  
Boiling Point ◽  
Room Temperature ◽  
Quadratic Function ◽  
Organic Liquids ◽  
Heat Of Vaporization ◽  
Boiling Points ◽  
Temperature And Pressure ◽  
Heats Of Vaporization

At any pressure the heat of vaporization can be expressed as a quadratic function of the boiling point at that pressure. A seven parameter equation expressing the simultaneous dependence on boiling point and pressure can be fitted to the data; six pressures from 1 to 760 Torr (1 Torr = 133.3 Pa) were used. ΔHvap = b11 + b12 In (p) + b13p + (b21 + b22 In (p))tbp + (b31 + b32 In (p))tbp2. This relationship served as a guide for developing a relationship between vapour pressure at 25 °C and the calorimetric heat of vaporization, and also a relationship between vapor pressure at 25 °C and the boiling point at some other pressure. Parameters for both these relationships could be derived from the parameters obtained for ΔHvap as a function of temperature and pressure. A third method was developed starting from an equation for vapor pressure and fitting to the heat of vaporization, the heat capacity of vaporization, and at least one t,p point. These methods allow the estimation of the vapor pressure at room temperature from very meager data. The problems of errors in estimated values are discussed.

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