6 research outputs found
Nanofluids In Battery Cooling System
No full textThermal implications related to heat generation and potential temperature excursions during operation in lithium-ion batteries are of critical importance for electric vehicle safety, performance and life. Concurrently, appropriate thermal management strategies for lithium-ion batteries are crucial to maintain cell temperatures within a
desired range. Hence, the development of nanofluids to improve heat transfer capabilities in car batteries have attracted intense research activities in recent years. Nanofluids, which are stably dispersed or suspended nanosized particles in heat transfer liquids have
attracted substantial interest because they offer a promising alternative to the inherent problems of conventional working fluids. Besides, the nanoparticles do not settle in the fluid and do not cause clogging and damage to surfaces as with micron sized particles.
The problem statement of the project is to analyze the efficiency of nanofluids as heat transfer fluids for active thermal management in car batteries. The research
experimentally investigates the use of silica nanofluids and distilled water. In order to determine the efficiency of nanofluid as heat transfer fluids, experimental data such as
Reynolds number, heat transfer coefficient and Nusselt number of water and water based silica nanofluid that flow through a circular tube (Di=0.8 mm) are obtained. The flow
was assumed as fully laminar flow with uniform heat flux applied to the tube surface. Different weight concentrations of silica/water nanofluids (0.1, 0.2, 0.3, 0.4, 0.5wt %)
were used in the experiment. Based on the data collected, graphs of heat transfer coefficient of nanofluids at different concentrations and distilled water versus axial
distance over inner diameter of tube (Z/Di) and % heat transfer enhancement of nanofluis at different concentrations and distilled water versus (Z/Di) were plotted and analyzed. The results concluded that heat transfer coefficient and Nusselt number was significantly
enhanced using silica nanofluids as compared to distilled water as heat transfer fluids. Higher values of heat transfer coefficient and Nusselt number indicate that more heat is being transferred from the tube to the fluid which results in a significant reduction of the overall tube surface temperature. The heat transfer enhancement was found to be dependent on the nanoparticle concentrations. The maximum enhancement was recorded for 0.4 wt. % silica nanofluids with 6.9% increase in heat transfer coefficient
The antioxidant, wound healing properties and proteomic analysis of water extracts from the tropical cyanobacteria, Nostoc NIES-2111_MUM004
No full textCyanobacteria bioactive compounds are chemical treasure troves for product discovery and development. The wound healing effects and antioxidant capacities of water extracts from Nostoc NIES-2111_MUM004 were evaluated via in vitro wound scratch assay and three antioxidant assays respectively. Results showed that the water extracts were protein-rich and exhibited good antioxidant properties in ABTS radical scavenging (11.27 ± 0.205 mg TAE g−1 extract), Ferric reducing antioxidant power (1652.71 ± 110.71 mg TAE g−1 extract) and β-carotene bleaching assay (354.90 ± 31.80 mg TAE g−1 extract). Also, extracts were non-cytotoxic in concentrations up to 250 µg/mL as reflected in cytotoxicity assay. Importantly, water extracts showed considerable proliferation and migration activity at 125 µg/mL with wound closure rate as high as 42.67%. Statistical correlation revealed no significant relationship (p > 0.05) between protein fraction and the wound healing properties, confirming that phycobiliproteins were not solely responsible for wound healing activities. Subsequent Q-TOF-LCMS analysis identified six protein families involved in enhancing the proliferation and migration of epithelial cells. These findings are antecedent in the uncovering of continuous supplies of bioactive compounds from new and sustainable sources. Ultimately, enriching the microalgae menu for applications in pharmaceutical, nutraceutical and cosmeceuticals.</p
Thermal performance comparison between bias acoustic liner and acoustic liner for aircraft anti-icing
No full textAcoustic liner is essential to reduce noise pollution in the aircraft engine. There
is a suggestion to reduce more noise by installing the acoustic liner on the nacelle lip-skin.
However, there are thermal issues including a low temperature of the acoustic liner surface and
its poor heat transfer mechanism increase of ice thickness on the nacelle surface. This phenomenon leads to the higher engine power to increase the acoustic liner surface tempera-ture.
Thus, aircraft manufacturers proposed to install the bias acoustic liner instead of the acoustic
liner on the nacelle lip-skin integrated with an anti-icing system to improve the thermal characteristics of the acoustic liner. Therefore, the present work studies the thermal performance
comparison between bias acoustic liner and acoustic liner on the nacelle lip-skin integrated with
an aircraft anti-icing system. The simulation study is conducted using the CFD ANSYS Fluent
in four different real flight conditions including taxi, climb, hold, and descent. The numbers of
both acoustic liners and bias acoustic liners are varied from 1 to 6. The results show that the
local dimensionless temperature of nacelle lip-skin with the bias acoustic liner at wrap locations
is between 39 % and 100 % higher than that of the nacelle lip-skin with the acoustic liner alone.
Further, the average dimensionless temperature of the nacelle lip-skin called the ratio between
the average temperature of the nacelle lip skin with respect to ambient and the temperature of
the hot air with respect to ambient are analyzed. The maximum average dimensionless temperature of nacelle lip-skin increases to 31.36 %, 26.35 %, 30.43 %, and 13.8 % for the climb,
descent, hold, and taxi conditions, respectively, when considering bias acoustic liner instead of
acoustic liner. The hold condition shows the highest average Nusselt number with the increasing number of bias acoustic liners, followed by descent, taxi, and climb conditions. In conclusion, the bias acoustic liner enhances the thermal performance of the nacelle lip-skin anti-icing
system
Comparison of mental-physical comorbidity, risk of death and mortality among patients with mental disorders - a retrospective cohort study
No full textAim: To compare the risk of death, the prevalence of comorbid chronic physical illness and mortality among an Asian population of patients with mental disorders.
Methods: This was a retrospective data analysing of medical records of patients with schizophrenia, depression, anxiety, bipolar disorder, alcohol use disorder (AUD) or substance use disorder and the comorbid chronic physical illnesses. The hazard risk of death was calculated with Cox regression and compared between patients with and without comorbid chronic physical illness(es). Odds ratios of specific comorbid chronic physical illness were calculated with logistic regression and mean crude death rate was calculated for patients with different mental disorders.
Results: A total of 56,447 patients with mental disorders were included in the analysis. Compared to patients without comorbid physical illness, patients with mental-physical comorbidity were associated with a higher risk of death [2.36 (2.22–2.52); hazard ratio (95% CI)] and less estimated survival days [2157 (2142–2172) vs 2508 (2504–2513)]. Compared to other mental disorders, those with AUD had the highest prevalence of two or more comorbid chronic physical illnesses and associated with the highest odds of comorbid hypertension, diabetes mellitus, stroke, nephritis, chronic kidney disease, and cancer. The highest one-year crude death rate was similarly observed in patients with AUD.
Conclusions: Mental-physical comorbidity was associated with a higher risk of death compared to patients with mental disorders only. The highest prevalence of mental-physical comorbidity and mortality were observed in patients with AUD. More attention and resources may be needed to tackle the burden of AUD
