Thermophysical Properties of Copper/Water Nanofluid for Automotive Cooling System – Mathematical Modeling

Nanofluid is an advanced fluid with enhanced thermophysical properties that has been introduced in many applications for better heat transfer process. In automotive cooling system, conventional coolants such as water and ethylene glycol could have superior thermophysical properties of thermal conductivity, viscosity, density and heat transfer coefficient by introducing nanoparticles suspension. This study investigated the thermophysical properties of Copper/Water nanofluid by using mathematical modeling approach to come out with a new coolant for Louvered-fins and flat tube of a radiator. The nanofluid showed enhanced thermophysical properties with nanoparticles suspension of 2 vol.% to 10 vol.%. By offering 10 % of copper nanoparticles concentration, the heat transfer coefficient of the nanofluid was increased up to 26000 W.m-2K-1 with enhancement of 92 %. Consequently, it also enhanced the heat transfer rate in the cooling system. The different particles sizes of 10 nm, 50 nm, and 100 nm showed different heat transfer coefficients but the heat transfer rate in the radiator is similar, up to 64400 W with 10 % of nanoparticle volume fraction. The nanofluids showed better heat transfer characteristics as a new alternative coolant for the radiator

Effects of Reduction of MHCII Expression on M1 Polarity Activated HMC3 Microglia Cells by N-Hexane and Ethyl Acetate Fraction of Semanggi (Marsilea Crenata Presl.) Leaves: Efek Penurunan Ekspresi MHCII Pada Sel Mikroglia HMC3 Teraktivasi M1 Polarity Oleh Fraksi N-Heksana Dan Etil Asetat Daun Semanggi (Marsilea Crenata Presl.)

Neuroinflammatory is a pathological condition in which neuronal cells experience progressive loss of function, one of which is due to estrogen deficiency. Phytoestrogens are compound that has structure and function similar to 17β-estradiol, the most potent natural form of estrogen. Semanggi (Marsilea crenata Presl.) is known to contain phytoestrogens which can replace the function of 17β-estradiol in maintaining organ homeostasis, so that is potential to be developed as an anti-neuroinflammatory drug. This study was aimed to prove the anti-neuroinflammatory effect of the n-hexane and ethyl acetate fraction of Semanggi leaves on HMC3 microglia cells, by measuring the expression of major histocompatibility complex II (MHC II). Both fractions with a concentration of 62.5; 125; and 250 μg/ml were administered to HMC3 microglia cells which had been induced by interferon gamma (IFN-γ) for 24 hours. Measurement of MHC II expression were using immunocytochemistry (ICC) methods and confocal laser scanning microscopy (CLSM) instruments. The results showed that n-hexane fraction could reduce MHC II expression at concentrations of 250 μg/ml with p<0.05, and showed a non-monotonic dose response (NMDR) pattern, while ethyl acetate fraction could reduce MHC II expression at all concentrations with p<0.05. Based on the results of the correlation test, the best anti-neuroinflammatory activity on HMC3 microglia cells is showed by the ethyl acetate fraction of Semanggi leaves