A Numerical Investigation of Thermal Airflows over Strip Fin Heat Sinks

The benefits of using strip fin heat sinks (SFHSs) where the cross-sectional aspect ratio of the fins lie between those for plate fins (high aspect ratio) and pins fins (aspect ratio≈ 1) are explored computationally, using a conjugate heat transfer model. Results show that strip fins provide another effective means of enhancing heat transfer, especially when staggered arrangements of strip fins are used. A detailed parameter investigation demonstrates that perforating the strip fins provide additional improvements in terms of enhanced heat transfer, together with reduced pressure loss and heat sink mass. Results are also given which show that, for practical applications in micro-electronics cooling, perforated SFHSs offer important benefits as a means of achieving smaller processor temperatures for reduced mechanical power consumption

An appraisal of the thermal decomposition mechanisms of ILs as potential lubricants

Ionic liquid (IL) lubricants are rapidly seeing increased use as either base lubricants or additives for a wide range of functionalities. This study considers the thermal stability of the ILs with the emphasis being their use as potential lubricants. The effect of IL chemistry, including anion chain length, cation chain length, anion type, and cation type, on their thermal stability is studied. The decomposition mechanism as a function of time and temperature is considered. Five ILs are studied by utilising both thermogravimetric analysis (TGA) for the dynamic thermal decomposition and Fourier transform IR spectroscopy (FTIR) for the static thermal decomposition. For static thermal decomposition, both time and temperature are varied. The results show that the variation of IL chemistry directly influences their thermal stability. The increase of either cation or anion chain length decreases their thermal stability. Both anion and cation type have a significant influence on the thermal stability

Reactivity of oil‐soluble IL with silicon surface at elevated temperature

The reactivity of an oil‐miscible ionic liquid, phosphonium phosphate (PP), and the common anti‐wear additive zinc dialkyl dithio phosphate (ZDDP) with a solid surface at elevated temperature in the absence of any tribological motion is investigated. Understanding the thermal film build up, composition, and relative thickness will help in the understanding of lubrication mechanisms once tribological effects are introduced. Attenuated total reflection–Fourier transform infrared (ATR‐FTIR), scanning electron microscopy–energy dispersive spectroscopy (SEM‐EDS), and X‐ray photoelectron spectroscopy (XPS) are employed to characterise silicon surfaces before and after the experiments in terms of surface chemistry and surface morphology. The results show that both additives react with the silicon surface to produce thermal films. However, ZDDP forms a thicker film. PP reacts with the silicon and forms a thermal film, but the reaction rate is self‐limited such that an increase of time to 24 hours does not significantly increase the film thickness

A Numerical Investigation of the Thermal-Hydraulic Characteristics of Perforated Plate Fin Heat Sinks

The benefits of using notch, slot and multiple circular perforations in plate fin heat sinks (PFHSs), are investigated numerically, using a conjugate heat transfer model. Comparisons show that each type of perforation can provide significantly reduced pressure drops over PFHSs but that fins with slot perforations provide the most effective design in terms of heat transfer and pressure drop. The practical benefits of each type of perforated fin for micro-electronics cooling is also explored and their capabilities of achieving low processor temperatures for reduced mechanical power consumption are quantified

Probucol Release from Novel Multicompartmental Microcapsules for the Oral Targeted Delivery in Type 2 Diabetes

In previous studies, we developed and characterised multicompartmental microcapsules as a platform for the targeted oral delivery of lipophilic drugs in type 2 diabetes (T2D). We also designed a new microencapsulated formulation of probucol-sodium alginate (PB-SA), with good structural properties and excipient compatibility. The aim of this study was to examine the stability and pH-dependent targeted release of the microcapsules at various pH values and different temperatures. Microencapsulation was carried out using a Büchi-based microencapsulating system developed in our laboratory. Using SA polymer, two formulations were prepared: empty SA microcapsules (SA, control) and loaded SA microcapsules (PB-SA, test), at a constant ratio (1:30), respectively. Microcapsules were examined for drug content, zeta potential, size, morphology and swelling characteristics and PB release characteristics at pH 1.5, 3, 6 and 7.8. The production yield and microencapsulation efficiency were also determined. PB-SA microcapsules had 2.6 ± 0.25% PB content, and zeta potential of −66 ± 1.6%, suggesting good stability. They showed spherical and uniform morphology and significantly higher swelling at pH 7.8 at both 25 and 37°C (p < 0.05). The microcapsules showed multiphasic release properties at pH 7.8. The production yield and microencapsulation efficiency were high (85 ± 5 and 92 ± 2%, respectively). The PB-SA microcapsules exhibited distal gastrointestinal tract targeted delivery with a multiphasic release pattern and with good stability and uniformity. However, the release of PB from the microcapsules was not controlled, suggesting uneven distribution of the drug within the microcapsules

Pharmacokinetic-Pharmacodynamic Modeling in Pediatric Drug Development, and the Importance of Standardized Scaling of Clearance.

Pharmacokinetic/pharmacodynamic (PKPD) modeling is important in the design and conduct of clinical pharmacology research in children. During drug development, PKPD modeling and simulation should underpin rational trial design and facilitate extrapolation to investigate efficacy and safety. The application of PKPD modeling to optimize dosing recommendations and therapeutic drug monitoring is also increasing, and PKPD model-based dose individualization will become a core feature of personalized medicine. Following extensive progress on pediatric PK modeling, a greater emphasis now needs to be placed on PD modeling to understand age-related changes in drug effects. This paper discusses the principles of PKPD modeling in the context of pediatric drug development, summarizing how important PK parameters, such as clearance (CL), are scaled with size and age, and highlights a standardized method for CL scaling in children. One standard scaling method would facilitate comparison of PK parameters across multiple studies, thus increasing the utility of existing PK models and facilitating optimal design of new studies

Protective Role of Pomegranate Peel (Punica granatum L) against Thioacetamide-Induced cirrhosis in a Rat Model

This study was designed to determine the effects of pomegranate peel on various antioxidiants measurements in liver cirrhosis of rats induced by thioacetamide.Fifty-seven male rats aged 13–15 weeks were randomly divided into 15 categories containing 5 rats per category, and were treated with either TAA, PP, or PP plus TAA or Selenium plus TAA or administered with 0.9% physiological saline solution as a control. The hepatoprotective effect of herbs was evaluated by measuring levels of antioxidiant marker enzymes such as Glutathione Peroxidase (GSH-Px) and Superoxide Dismutase (SOD) and measurement Malondialdehyde (MDA). The histological studies were also carried out to support the above parameters by using special stain Haemotoxlin & eosin and using immunofluorescent staining to examine the distribution of DDR2 in the liver. The study found that the supplementation of pomegranate peel significantly (p< 0.05) reduced the damaging effects on the liver by TAA. GSH, SOD increased in the treatment group, but serum MDA level was declined due to the hepatic injury induced. A comparative histopathological research of the liver between different groups demonstrated that pomegranate peel, drive to normal liver architecture suggesting they may use as a hepatoprotective alternative medicatio