MIR imaging bundles of ordered silver halide polycrystalline fibres for thermal transmission and imaging

This study aims to experimentally examine the energy-saving potential by using R-134a filled separated two-phase thermosiphon loop (STPTL) for data center applications. A parametric study had been made to compare the energy consumption of two data center racks. Two fin-and-tube heat exchangers were attached to one of the racks to form two individual thermosiphon loops. The experiments were carried out subject to different operating conditions, including three ambient temperatures (20 °C, 23 °C, and 27 °C) and filling ratios ranging from 30 to 90% in association with heating loads ranging between 1.5 kW and 6 kW. Parametric influences regarding concentrated heat loading or uniform heat loading are studied. It was found that an appreciable energy-savings can be obtained at high filling ratios and a maximum of 49% energy-saving with the assistance of thermosiphon is observed. Accordingly, the rising of system pressure will result in noticeable savings. Relative to the uniform heat loading of the data rack, the thermosiphon shows even more energy-saving potential in concentrated heat loading. This phenomenon is more pronounced at a lower ambient temperature like 20 °C. On the other hand, there is no appreciable energy-saving for the thermosiphon between concentrated and uniform heating loads when the ambient temperature is high (27 °C). Furthermore, the influence of airflow rate was also investigated under various ambient temperatures with a 90% filling ratio and a heating load of 6 kW. The results revealed that the lower airflow rate in the thermosiphon yields comparatively better energy-saving than the higher flow rate. The study on the influence of using two STPTLs indicated that 15–23% energy-saving can be achieved at a 90% filling ratio and 6 kW heating load for all the studied ambient conditions if compared with testing each loop separately. Lower thermal resistance is seen at the higher filling ratios, ambient temperatures, and heating loads.

     

Pressure Improvement on a Supercritical High-Lift Wing Using Simple and Modulated Pulse Jet Vortex Generator

In this paper, an experimental study, aimed at delaying flow separation on a high-lift device using a pulsed blowing excitation method, is reported. The main objective of this investigation was to evaluate a new pulsed jet generation strategy to enhance flow control performance. In these experiments, two types of signal waveform were implemented to produce the unsteady blowing; a simple square-wave excitation signal for the first case, and a burst modulated excitation signal for the second case. The signal modulation was the first time to be used for a fast-switching solenoid valve actuator. Another objective of this study was to evaluate a new arrangement of the jet exit slots, in the form of a vortex generator which was employed for the first time on the high-lift device. For this purpose, a NASA SC(2)-0714 airfoil with a single slotted flap was employed. The vortex generator jets emanated from the shoulder of the trailing-edge flap with excitation frequencies from 40 to 1000 Hz. Pressure distribution around the model and wake total pressure deficit were measured. The results indicated that ejection from vortex generator slot pairs was able to prevent flow separation completely in most conditions. These measurements revealed that the burst modulated excitation signal was accompanied by more aerodynamic improvements and less air consumption relative to the simple pulsed jet excitation signal. In the best flow control mode, the results showed about a 53% increase in the value of the suction pressure peak on the flap and a 38% decrease in drag with a reduction in total pressure loss.

     

Third body modeling in fretting using the combined finite-discrete element method

A new approach was developed for modeling the effect of the third body on fretting. This was accomplished using the combined finite-discrete element method (FDEM) in which the third body is analyzed as discrete elements while the first bodies are modeled using finite elements. This approach provides a link between large scale models which treat the mass of wear debris as a single or small number of bodies and small scale models which only study a control volume. The FDEM was used to analyze the behavior of third body particles between flat sliding surfaces. When the third body mass is composed of unconnected particles, it behaves as a Newtonian fluid, but this behavior ceases when the particles are connected into platelets. The FDEM was also used to study the behavior of third body particles inside a Hertzian line contact. As the number of particles and platelet size increase the load carried by the worn slip zone grows larger in relationship to the unworn stick zone.     

Biotechnological Innovations from Ocean: Transpiring Role of Marine Drugs in Management of Chronic Disorders

Marine drugs are abundant in number, comprise of a diverse range of structures with corresponding mechanisms of action, and hold promise for the discovery of new and better treatment approaches for the management of several chronic diseases. There are huge reserves of natural marine biological compounds, as 70 percent of the Earth is covered with oceans, indicating a diversity of chemical entities on the planet. The marine ecosystems are a rich source of bioactive products and have been explored for lead drug molecules that have proven to be novel therapeutic targets. Over the last 70 years, many structurally diverse drug products and their secondary metabolites have been isolated from marine sources. The drugs obtained from marine sources have displayed an exceptional potential in the management of a wide array of diseases, ranging from acute to chronic conditions. A beneficial role of marine drugs in human health has been recently proposed. The current review highlights various marine drugs and their compounds and role in the management of chronic diseases such as cancer, diabetes, neurodegenerative diseases, and cardiovascular disorders, which has led to the development of new drug treatment approaches.     

Combined electroosmotically and pressure driven flow of power-law fluids in a slit microchannel

Electroosmotic flow of power-law fluids in the presence of pressure gradient through a slit is analyzed. After numerically solving the Poisson–Boltzmann equation, the momentum equation with electroosmotic body force is solved through an iterative numerical procedure for both favorable and adverse pressure gradients. The results reveal that, in case of pressure assisted flow, shear-thinning fluids reach higher velocity magnitudes compared with shear-thickening fluids, whereas the opposite is true when an adverse pressure gradient is applied. The Poiseuille number is found to be an increasing function of the dimensionless Debye–Hückel parameter, the wall zeta potential, and the flow behavior index. Comparison between the exact and the results based on the Debye–Hückel linearization reveals that the simplified solution leads to large errors in evaluating the velocity profile for zeta potentials higher than 25 mV, except for shear-thickening fluids in the presence of favorable pressure gradient.     

Purification of soybean oil with phospholipase Al

An enzymatic degumming step in the production of edible soybean oil is carried out. The phosphatides are present in free hydratable form (HP) or in nonhydratable form (NHP). The main characteristic of the discovery is the use of phospholipid A1 (Lecithin Ultra) enzyme, which catalyzes reactions at specific temperatures. The mechanism includes the conversion of nonhydratable phospholipids into water-soluble lysophospholipids, which are then removed by centrifuge, yielding degumming oil low in phosphorus. The effects of important determining factors affecting oil degumming such as enzyme dosage, temperature and pH are investigated.