Influence of convective heat transfer coefficients on thermal behaviour of a lithium-ion cell: a numerical study.

In the current study, the impact of C-ratio, convective heat transfer coefficient, and free stream temperature on the maximal cell temperature and temperature uniformity was computationally and statistically examined. Results revealed that the free stream temperature was the main influential factor for the maximal cell temperature for both natural and forced convection conditions while the C-ratio was the most effective parameter for the temperature uniformity for both natural and forced convections. On the other hand, the contribution of the free stream temperature to the maximum battery temperature increased from 63% to 94% when the conditions were changed from natural convection to forced convection. Moreover, the contribution of the C-rate to the temperature uniformity decreased from 89% to 79% when the conditions were changed from natural convection to forced convection. The results obtained from this study are significant in terms of determining which factor should be given more importance under natural and forced convection conditions.

Parameter effect quantification for a phase change material-based lithium-ion battery thermal management system.

The influence of discharge rate, ambient temperature, and phase change material on the maximum temperature and the highest temperature difference was investigated. The maximum temperature of the battery was tested with and without phase change material under extreme discharge rates (4C and 5C) and ambient temperatures (310 K and 320 K). Results showed that a phase change material reduced the maximum temperature from 327.94 K to 306.45 K for a 14.6 Ah lithium-ion battery discharged at 5C-rate and 320 K. Quantitatively determined parameter effects revealed that the PCM parameter considerably had a remarkable influence on maximum temperature compared to discharge rate and ambient temperature. Moreover, the influence of ambient temperature on the maximum temperature was approximately 2.5 times greater than the C-rate, while the influence of ambient temperature on the highest temperature difference was approximately 50 times greater than the C-rate. The quantified parameter effects can be used to improve the phase change material-battery cooling system.

Investigation of electrochemical behavior of potassium ferricyanide/ferrocyanide redox probes on screen printed carbon electrode through cyclic voltammetry and electrochemical impedance spectroscopy.

Potassium ferricyanide, potassium ferrocyanide, and their combination system are widely used redox probes for electrochemical impedance spectroscopy (EIS) characterization. In this work, electrochemical behavior of K3Fe(CN)6, K4Fe(CN)6, and K3Fe(CN)6/K4Fe(CN)6 redox probes at five different concentrations using a screen printed carbon electrode (SPCE) by cyclic voltammetry (CV) and EIS methods was analyzed. Redox potentials were observed as a result of anodic and cathodic peak with CV analysis with determination 10 mM appropriate concentration through 0.01 mM, 0.1 mM, 1 mM, and 100 mM. In addition, with EIS analysis, each redox probe was simulated according to two different Randles circuit models and fitting equivalent model with varying concentration was determined and examined in detail. The results also demonstrated that selected high and low concentrations of redox probes can be categorized in two different models, although 1 mM behaved as a critical transition concentration. This study may contribute to the determination of relevant redox probe and its concentration in electrochemical investigations by selecting K3Fe(CN)6/K4Fe(CN)6 to decrease any risk of inaccuracy.

Decellularized inner body membranes for tissue engineering: A review.

Body membranes are thin sheets/layers of cells or tissues which cover the surface of internal organs, the outside of the body and lines various body cavities. These membranes are separated into two main groups which are epithelial membranes and connective tissue membranes. Decellularized forms of inner body membranes in the groups of epithelial membranes (amniotic membrane, mesentery, omentum, pericardium, peritoneum, pleura) and connective tissue membranes (fascia, periosteum, synovial membrane) have been used in tissue engineering studies for preparation and regeneration of various tissues such as bone, tendon, cartilage, skin, cornea, ocular surface, uterine, periodontium, vascular and cardiovascular structures. Decellularized inner body membranes have high biocompatibility and support cell attachment, cell growth and angiogenesis which are desired properties for using as versatile tools in tissue engineering applications. Even though, decellularized forms of these membranes have been used in many studies, it is necessary to develop new decellularization methods for more effective cell removal and less destructive properties on tissue structures. Moreover, development of decellularization agents which target removal of antigens of donor tissues is also essential because these antigens are one of the main reasons for tissue-organ rejections in allogeneic and xenogeneic tissue-organ implantations. This review provides comprehensive information and analysis about the current state of the art in the literature on decellularized inner body membranes and applications of these membranes in tissue engineering.

Analysis of electrochemical impedance spectroscopy response for commercial lithium-ion batteries: modeling of equivalent circuit elements.

Electrochemical impedance spectroscopy measurements were performed to capture the physically meaningful parameters of commercially available 18650 cylindrical and 2032 coin cells by using the equivalent circuit model. The impedance response of the batteries was systematically investigated and discussed. A detailed analysis was achieved providing a determination of influential factors on the equivalent circuit parameters. The results suggested that the cell type tested here influenced the equivalent circuit elements profoundly. Taguchi analysis indicated that state-of-charge had the highest effect on the cathodic constant-phase-element exponent. The results contribute to full electrochemical analysis that is required for battery characterization.

Pyrolysis of hornbeam (Carpinus betulus L.) sawdust: Characterization of bio-oil and bio-char.

Slow pyrolysis of hornbeam (Carpinus betulus L.) sawdust was performed to produce bio-oil and bio-char. The operational variables were as follows: pyrolysis temperature (400-600°C), heating rate (10-50°Cmin-1) and nitrogen flow rate (50-150cm3min-1). Physicochemical and thermogravimetric characterizations of hornbeam sawdust were performed. The characteristics of bio-oil and bio-char were analyzed on the basis of various spectroscopic and chromatographic techniques such as FTIR, GC-MS, 1H NMR, SEM, BET. Higher heating value, density and kinematic viscosity of the bio-oil with maximum yield of 35.28% were 23.22MJkg-1, 1289kgm-3 and 0.6mm2s-1, respectively. The bio-oil with relatively high fuel potential can be obtained from the pyrolysis of the hornbeam sawdust and the bio-char with a calorific value of 32.88MJkg-1 is a promising candidate for solid fuel applications that also contributes to the preservation of the environment.