Shiv Nadar University

About: Shiv Nadar University is a education organization based out in Dadri, Uttar Pradesh, India. It is known for research contribution in the topics: Population & Graphene. The organization has 1015 authors who have published 1924 publications receiving 18420 citations.

Performance Enhancement of a Refrigerator Using Phase Change Material-Based Condenser: An Experimental Investigation

Abstract: Tropical countries like India, the ambient temperature reaches to 45–50∘C in the summer and higher ambient temperature directly impacts the energy required by the household refrigerator. This paper presents an experimental performance of a domestic refrigerator incorporated with a phase change material (PCM)-based condenser in parallel to the conventional wire-and-tube air-cooled condenser for the climatic conditions of India. It is proposed to operate the refrigerator with the PCM-based condenser, while the ambient temperature is higher during the day, otherwise with the air-cooled condenser. Due to large latent heat storage capacity of the PCM, the condenser temperature would not increase significantly. The COP of the PCM-based condenser was 28% higher as compared to air cooled condenser for 60min which reduce to 3% as PCM temperature reached to 33∘C. The energy consumption is lower by ∼15% in 312h of refrigerator experimentation with the proposed modification.

Selective U(VI) removal using phosphorous-doped graphitic carbon

Abstract: Development of materials for selective recovery of uranium (U) from contaminated water and sea water is necessary to solve the issues related to sources of U(VI) for nuclear energy and alleviating the environmental pollution. Phosphorous-doped Graphitic (P-Gc) material, synthesized under microwave irradiation (450 W, 40 s) has been utilized as potential adsorbent material for U removal in ppm level from contaminated water selectively at room temperature (RT). The influence of various environmental conditions (e.g. pH, contact time, ionic strength, and temperature) on U(VI) adsorption was investigated by batch method. Maximum Adsorption capacity (QM) was found 1186 mg g−1 from Langmuir fit and this could be due to high specific surface area of P-Gc (1635 m2/g) and the presence of phosphate functionalities (3.18 atomic wt% P according to XPS) on the adsorbent surface. The results of kinetic and thermodynamic studies revealed that the adsorption was a spontaneous and exothermic chemical process and the adsorption process could be better fitted by a pseudo-second order model, suggesting a chemisorption over physisorption. The adsorption of U(VI) on P-Gc was a multilayer uptake in lower concentration range of U(VI) and monolayer in higher concentration range of U(VI). The material has been reused for five cycles with almost no change in the efficiency which is very important for the wastewater treatment. 90 % of the adsorbed uranium was regenerated from P-Gc by simple acid treatment. Hence, P-Gc has a great promise in the quest to development of metal free adsorbent for uranium removal at RT.