Experimental Evaluation of Performance of Different Thermal Boxes Heated by Solar Radiation for Hot Water Storage System

The aim of this research is to investigate the performance of different thermal boxes heated by solar radiation for a water storage system that can be used in accordance with the climate of Asia-Pacific countries. In general, this research is related to thermal efficient water heating system, specifically to improve the water heating system that exists nowadays. The focus is to improve the thermal efficiency by adding different thermal boxes as the absorber bed. By implementing the black body and radiation concept, the air trapped in the box is heated. The trapped air then increases the collisions between the molecules and directly increases the temperature inside the box, higher than the outside environment. Based on theory and concept purposed, the temperature of the water increases more efficient and faster by using radiation heat as the source. Based on 24 hours experimental results revealed steel thermal box is better to be used for tropical weather like Malaysi

The Effects of Heterospecific Mating Frequency on the Strength of Cryptic Reproductive Barriers

Heterospecific mating frequency is critical to hybrid zone dynamics and can directly impact the strength of reproductive barriers and patterns of introgression. The effectiveness of post-mating prezygotic (PMPZ) reproductive barriers, which include reduced fecundity via heterospecific matings and conspecific sperm precedence, may depend on the number, identity and order of mates. Studies of PMPZ barriers suggest that they may be important in many systems, but whether these barriers are effective at realistic heterospecific mating frequencies has not been tested. Here, we evaluate the strength of cryptic reproductive isolation in two leaf beetles (Chrysochus auratus and C. cobaltinus) in the context of a range of heterospecific mating frequencies observed in natural populations. We found both species benefited from multiple matings, but the benefits were greater in C. cobaltinus and extended to heterospecific matings. We found that PMPZ barriers greatly limited hybrid production by C. auratus females with moderate heterospecific mating frequencies, but that their effectiveness diminished at higher heterospecific mating frequencies. In contrast, there was no evidence for PMPZ barriers in C. cobaltinus females at any heterospecific mating frequency. We show that integrating realistic estimates of cryptic isolation with information on relative abundance and heterospecific mating frequency in the field substantially improves our understanding of the strong directional bias in F1 production previously documented in the Chrysochus hybrid zone. Our results demonstrate that heterospecific mating frequency is critical to understanding the impact of cryptic post-copulatory barriers on hybrid zone structure and dynamics, and that future studies of such barriers should incorporate field-relevant heterospecific mating frequencies

Permeance Based Algorithm For Computation Of Flux Linkage Characteristics Of Non-Linear 6/4 Switched Reluctance Motor (SRM)

The concept of permeance is used in the analysis of flux linkage of 6/4 SRM. The aim of this paper is to develop an efficient algorithm exploiting the nonlinear feature of the 6/4 SRM using the aforementioned concept of permeance. The first step is to generate the relevant equations related to permeances of the 6/4 SRM under study. The 6/4 SRM’s magnetization curve is then derived from the summation of mmf drops at various blocks representing the motor. The air gap permeances are derived at various angles and 3-D leakage effects are taken into account. These permeances are used for the mmf drop computation. The algorithm is capable of efficiently computing mmf drop at every block to consequently yield a complete accurate nonlinear flux linkage feature of the 6/4 switched reluctance motor. In this way, the capability of the SRM to produce the expected four times the specific output torque due to operation in high saturation region compared to an equivalent induction motor as special the attribute of the SRM is demonstrated

Hearing and dementia

Hearing deficits associated with cognitive impairment have attracted much recent interest, motivated by emerging evidence that impaired hearing is a risk factor for cognitive decline. However, dementia and hearing impairment present immense challenges in their own right, and their intersection in the auditory brain remains poorly understood and difficult to assess. Here, we outline a clinically oriented, symptom-based approach to the assessment of hearing in dementias, informed by recent progress in the clinical auditory neuroscience of these diseases. We consider the significance and interpretation of hearing loss and symptoms that point to a disorder of auditory cognition in patients with dementia. We identify key auditory characteristics of some important dementias and conclude with a bedside approach to assessing and managing auditory dysfunction in dementia

Effect of absorbed hydrogen on crack-tip ductility in the welded A516 steel

Effects of absorbed hydrogen on structure and properties of welded A516 Grade-70 steel are investigated. Emphasis is placed on ductility measure of the crack-tip plastic zone under Mode I loading. Specimens are cathodically charged in a cell with dilute sulphuric acid and corrosion inhibitor with uniform charging current density of 20 mA/ cm2 and at different exposure time. Results indicate a change from coarse- to fine-grained microstructures in the weld region and heat affected zone (HAZ) of hydrogen-charged specimen. Well-defined ferrite-pearlite bands in the base metal are transformed into coarse-grain structure. Hardness variation along radial distance indicates higher values towards the center of the bar, possibly due to faster diffusion rate but limited solubility of hydrogen. Load-COD responses indicate that slow, stable crack propagation occurred in both base metal and HAZ. The measured provisional fracture toughness, KQ is higher for HAZ than that for the base metal. The toughness values decreases significantly for the initial three hours of hydrogen charging. The tensile fracture region in the immediate fatigue pre-crack tip forms a triangular (rough) zone due to limited constraint to free surface deformation in the thin specimen. Fracture surface of HAZ is dominated by intergranular fracture with localized cleavage facets

Infectious Agents in Immunodeficient Murine Models: Pathogenicity of Nocardia asteroides in Congenitally Athymic (Nude) and Hereditarily Asplenic (Dh/+) Mice

Congenitally athymic (Nu/Nu), hereditarily asplenic (Dh/+), and littermate control mice were given intravenous injections of homogeneous cell suspensions of the virulent Nocardia asteroides GUH-2. Kill curve, 50% lethal dose, and kidney clearance data were obtained over a period of 3 months postinfection. N. asteroides initiated both an acute infectious process and a chronic, progressive disease in these animals when given intravenously. The heterozygous (Nu/+) mice appeared to be slightly more susceptible to the acute phase of infection than their nude littermates. In contrast, nude mice were at least 50 times more susceptible to chronic nocardial infection than were the heterozygous (Nu/+) controls. Swiss Webster specific pathogen-free mice were similar to heterozygous (Nu/+) mice in their susceptibility to N. asteroides. The hereditarily asplenic (Dh/+) mice were not as susceptible to lethal infection as were nude mice. However, asplenic mice demonstrated an inability to eliminate nocardia from infected kidneys, whereas their littermate control (+/+) mice were able to mount an effective response and destroy most of the organisms within the kidneys. Similar observations were noted when nude and heterozygous (Nu/+) littermate mice were infected in the footpad. The nude mice developed a systemic infection and died within 4 weeks with little inflammation of the footpad and no macroscopic lesions. In contrast, heterozygous (Nu/+) mice developed extensive local abscesses in the foot that persisted for at least 4 weeks. There was no animal death and no evidence of dissemination. The data presented herein indicate that T cells are essential for adequate host response against infection with a virulent strain of N. asteroides

Infectious agents in immunodeficient murine models: pathogenicity of Actinomyces israelii serotype I in congenitally athymic (nude) mice.

Nude (Nu/Nu) and heterozygous (NU/+) mice were infected with Actinomyces israelii serotype I by either intranasal instillation or intravenous injection. Lung clearance data and 50% lethal dose values indicated that T-lymphocytes were not necessary for pulmonary clearance or prevention of systemic actinomycosis. However, T-lymphocyte deficiency may play a role in the localized cervicofacial form of actinomycosis