Yazar "Sharma, R. K." seçeneğine göre listele

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    Capric-stearic acid mixture impregnated carbonized waste sugar beet pulp as leak-resistive composite phase change material with effective thermal conductivity and thermal energy storage performance
    (Pergamon-Elsevier Science Ltd, 2022) Sarı, Ahmet; Hekimoğlu, Gökhan; Karabayır, Yasemin; Sharma, R. K.; Arslanoğlu, Hasan; Gencel, Osman; Tyagi, V. V.
    The present investigation aims to develop a potential composite phase change material (PCM) with leak-resistive and high thermal conductivity. Sugar beet pulp (CSBP) as an industrial waste was carbonized to produce a porous framework and used for solving leakage issue and boosting thermal conductivity of capric-stearic acid eutectic mixture (CSEM) used as PCM. FTIR and XRD results proved that the integration of CSEM and CSBP was carried out physically. The SEM analysis demonstrated that the CSEM was well uniformly impregnated within the pores of CSBP scaffold. DSC analysis revealed that the CSBP/CSEM (70 wt%) composite showed melting enthalpy and temperature as 117 J/g and 24 degrees C. The TGA measurements demonstrated that the produced composite was thermally stable. The incorporation of CSEM with CSBP leaded to a 79% increase in its thermal conductivity and this improvement was proved by comparing heating-cooling periods of CSEM and the composite PCM. The latent heat of the composite PCM was reduced less than 3% as its melting temperature was almost constant after 1000 thermal cycles. All findings of this work disclosed that the developed CSBP/CSEM as cost-effective and environmentally friendly composite PCM can be handled potential TES material for temperature controlling of buildings. (C) 2022 Elsevier Ltd. All rights reserved.
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    Valorization of waste biomass derived activated carbon @expanded graphite for intensification of thermal characteristics of RT24 phase change material through shape-stabilization
    (Elsevier, 2025) Gowthami, D.; Sharma, R. K.; Kar, Turgay; Sarı, Ahmet; Arslanoğlu, Hasan; Eren, Sena; Gençel, Osman
    The basic philosophy of this work is to create cleaner energy alternative materials for solar thermal energy storage applications. This experimental evaluation focuses on elevating the thermal characteristics of Rubitherm paraffin (RT24) by incorporating a hybrid matrix for shape stabilization. The hybrid matrix was fabricated by infusing expanded graphite (EG) (5 wt% and 10 wt%) into carbonized sugar beet pulp and vinasse wastes (BAC). The shape-stabilization of RT24 was carried out in vacuum to achieve uniform dissipation. The synthesized hybrid supporting matrices were adequately porous with highest BET surface area of 411.25 m2/g after adding EG(5 wt%) to BAC. According to TGA analysis BAC/RT24, BAC@5%EG/RT24(45 %) and BAC@10%EG/RT24 (60 %) were highly resistant to heat with corresponding mass loss of 39.4 %, 44.7 % and 59.8 % at around 280 degrees C. In accordance with XRD and FTIR analysis PCM composites have not displayed structural or chemical transformation due to the presence of EG or BAC. The melting and solidifying latent heat values of BAC@10% EG/RT24(60 %) were measured as 132.15 J/g and 129.42 J/g respectively. Also, BAC/RT24, BAC@5%EG/RT24 (45 %) and BAC@10%EG/RT24(60 %) have revealed high thermal reliability after performing 1000 thermal cycles with a variation of about 3 % in melting latent heat, thus signifying their adaptability into latent heat storage (LHS) systems. Thermal conductivity of the shape-stable BAC/RT24 composite was increased by 300 % compared to pure RT24 PCM as a result of adding 10 wt% EG to the composite. Especially BAC@10%EG/RT24 (60 %) composite can be utilized as cleaner energy alternative material for building solar thermal implementation because it had relatively higher LHS capacity and thermal conductivity value.