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This work reports hydrogen adsorption properties of four different metal–organic frameworks (MOFs) namely Zn-BDC, Cr-BDC, Ni-DABCO, and Mg-DOBDC. Gravimetric hydrogen adsorption measurements are performed over a wide range of temperature (90 K to 298 K) and pressure (0 bar to 100 bar). At the lowest experimental temperature (90 K to 100 K) all the isotherms are saturated and the adsorption capacity is governed by pore volume. On the other hand, at room temperature the isotherms closely follow Henry’s law. Modeling of the excess isotherms is also done. Net adsorption isotherms, which can directly indicate the efficiency of porous adsorbent for storage, are also presented. In terms of volumetric efficiency, Mg-DOBDC MOF exhibits best storage capacity out of all the MOFs considered in this study.

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Estimation of magneto-caloric effect is crucial to determine a material’s suitability for the desired operating conditions. The magneto-caloric effect can be measured in two ways-the magnetic entropy change and the adiabatic temperature change. These parameters are the prerequisites in evaluating a magnetic refrigeration system. In this work, an application is developed and tested for 3 materials (one Gadolinium and two Lanthanum alloys) using COMSOL multiphysics to estimate the final temperature of a Magneto-Caloric Material (MCM). The duration of the magneto-caloric effect is compared amongst 4 different cases of magnetic field change. Among the selected materials Gadolinium shows the highest adiabatic temperature difference of 12K at a field change from 0 to 5 tesla.

Solar refrigeration may have applications in both developed and developing countries. Applications in developing countries such as airconditioning, vaccine storage or large scale food preservation have been the subject of scientific research. Ammonia-water based system has good COP but generally vapor absorption refrigeration system requires high generator temperature and high circulating ratio aided by a powerful pump. Our objective was to trivialize the role of circulating ratio and simultaneously achieve higher COP. A prototype model was designed, fabricated in laboratory using scrap material and tested; performance of the unit has been analyzed. A parabolic solar trough was used as a source of heat. Various components were modeled in computer and analyzed using ANSYS. The performances and effectiveness of the unit was studied by determining refrigeration effect (RE) and coefficient of performance (COP).

In this work, a set of computational investigation results of two-phase refrigerant flow through adiabatic capillary are presented. There are various sizes of capillary tubes that can be selected related to commercially available copper tubes. Earlier refrigerants and new refrigerants like R12, R22, R134a, R410A and R32 are used for the flow analysis. Homogeneous-equilibrium model is employed with user-defined properties of the refrigerants for computation using ANSYS CFX. Several important parameters can be predicted rapidly and accurately using this method such as refrigerant mass flow rate, vapor mass fraction, local Mach no. etc. The mean deviation in mass flow rate is found to be [Formula: see text]1.18% for the same length of capillary tube and the mean deviation of tube length is found to be [Formula: see text]1.48% for the same experimental mass flow rate with choked flow condition.