MIR imaging bundles of ordered silver halide polycrystalline fibres for thermal transmission and imaging

This study aims to experimentally examine the energy-saving potential by using R-134a filled separated two-phase thermosiphon loop (STPTL) for data center applications. A parametric study had been made to compare the energy consumption of two data center racks. Two fin-and-tube heat exchangers were attached to one of the racks to form two individual thermosiphon loops. The experiments were carried out subject to different operating conditions, including three ambient temperatures (20 °C, 23 °C, and 27 °C) and filling ratios ranging from 30 to 90% in association with heating loads ranging between 1.5 kW and 6 kW. Parametric influences regarding concentrated heat loading or uniform heat loading are studied. It was found that an appreciable energy-savings can be obtained at high filling ratios and a maximum of 49% energy-saving with the assistance of thermosiphon is observed. Accordingly, the rising of system pressure will result in noticeable savings. Relative to the uniform heat loading of the data rack, the thermosiphon shows even more energy-saving potential in concentrated heat loading. This phenomenon is more pronounced at a lower ambient temperature like 20 °C. On the other hand, there is no appreciable energy-saving for the thermosiphon between concentrated and uniform heating loads when the ambient temperature is high (27 °C). Furthermore, the influence of airflow rate was also investigated under various ambient temperatures with a 90% filling ratio and a heating load of 6 kW. The results revealed that the lower airflow rate in the thermosiphon yields comparatively better energy-saving than the higher flow rate. The study on the influence of using two STPTLs indicated that 15–23% energy-saving can be achieved at a 90% filling ratio and 6 kW heating load for all the studied ambient conditions if compared with testing each loop separately. Lower thermal resistance is seen at the higher filling ratios, ambient temperatures, and heating loads.

     

New direction of the reaction between N,N′-disubstituted hydrazine and nitric acid

Conclusions The action of conc. HNO₃ on N,N-bis-(2,2-dinitropropyl)hydrazine and azo-(2,2-dinitro)propane at low temperatures was investigated, and it has been shown that in both cases 2,2-dinitropropionylhydrazone of 2,2-dinitropropionaldehyde is formed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1202–1203, May, 1970.     

Method of Probabilistic Convolutions for Interpreting Data of Electromagnetic Logging

A new method is proposed for processing the data of electromagnetic logging in wells. The method is based on the hydrodynamic analysis of drilling mud filtrate penetration into the oil stratum, determination of the field of electrical resistances of the near-well zone with its subsequent averaging by convolutions with a kernel in the form of a logarithmically normal distribution of probe sensitivity.     

CLOSED CIRCULATION OF THERMAL WATER STUDIED USING THE EMBEDDED CONTINUUM METHOD

Journal of Applied Mechanics and Technical Physics - A case of two-dimensional motion of thermal waters under the action of two wells comprising a spaced dipole is investigated on the basis of a...     

Phenomenological approach to simulating hydraulic fracturing of a stratum

A mathematical model for hydraulic fracturing is proposed. The model is based on the presentation of the fractured portion of the stratum adjacent to the well as a heterogeneous fractured porous medium. Assumptions usually used in the theory of elastic flow are applied. Formulas for determining the size of the hydraulic fracturing zone and the degree of fracture opening under conditions of relative equilibrium are derived.     

Effect of the drilling mud filtrate temperature on the resistivity of the stratum saturated by oil and gas

A mathematical model of the axisymmetric distribution of the phases in the zone of invasion of the water-based drilling mud into the productive stratum whose porous space can simultaneously contain three immiscible fluids (oil, gas, and natural water) is constructed; the model takes into account the high rate of heat transfer between the fluids and the rock matrix. It is shown that the resistivity of the invaded zone depends not only on saturation of the latter by the fluids and the concentration of salts in the water phase, but also on the drilling mud filtrate temperature. It is also shown that there is a jump in the function of stratum saturation by oil on the thermal front.     

Influx of oil to a gallery of water‐plugged wells

Within the framework of the Buckley–Leverett scheme, a solution is obtained for the problem of organization of an influx to a gallery of wells whose nearwell zone is contaminated for some reasons by the water phase. A method of engineering estimates is developed for the moment of penetration of the front of water displacing oil into the plugged zone of production wells with simultaneous determination of oil recovery in the reservoir. The results obtained may be used in constructing a mathematical model of optimized development of oil fields.     

Equilibrium self-polarization of clay

A condition of equilibrium between charged clay particle surfaces and the solution contained in the pore space of the rock is derived using electrical double layer theory. This condition is the relation linking the cation concentration in the middle surface of the pores with the exchange capacity of the clay, the total ion charges, and the specific surface area of the particles. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 5, pp. 96–103, September–October, 2007.