Analytic similarity solutions for fully resolved unsteady laminar boundary layer flow and heat transfer in the presence of radiation.

In this paper, we have compared a new type of similarity transformation derived systematically by using Lie point symmetries with the existing similarity transformations for unsteady fluid flow and heat transfer in the boundary layer in the presence of radiation. It is observed that the existing transformations map the steady and marginally accelerating flows only, while the Lie similarity transformations provide solutions for all types of accelerating flows and are independent of unsteadiness in the fluid. The previous transformations are valid for a specific time interval which depends on a range of unsteadiness parameter, however the Lie similarity transformations provide valid solutions at any given time. This implies that the Lie similarity transformations yield solutions for previously unexplored ranges of unsteadiness in the fluid. Boundary layer flow physics for both types of transformations is discussed by employing the Homotopy analysis method. We show that for accelerating fluids, in the developing region, the boundary layer thickness first increases and than starts to decrease with increase in unsteadiness for fully developed flow. Detailed comparison of velocity and temperature profiles in the boundary layer is made using the tables and graphs which show that with Lie similarity transformations the region of study of the considered flow extends significantly for the unsteadiness parameter. The effect of the Prandtl number and radiation parameter on temperature distribution is also compared for both types of similarity transformations. The Lie symmetry similarity transformations are shown to explain the unsteady laminar boundary layer flow and heat transfer to an extent where the existing similarity transformations do not work.

Synthesis and characterization of silver-indium and antimony selenide: role in photocatalytic degradation of dyes.

These days, water contamination poses a severe threat to the ecosystem and demands immediate care. This study examined the need to reduce water pollution using clean, renewable energy (solar light irradiations) for the degradation of Congo red by Silver-indium and antimony selenide with chemical composition AgInSbSe3. The sample was fabricated through a hydrothermal technique. The synthesized sample was characterized through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Ultraviolet-Visible spectroscopy. The X-ray diffraction confirms crystalline structure of the synthesized sample. The SEM analysis reveals irregular grains and exhibits a very small inter-particle distance. SEM provides the morphology of the synthesized sample, the grain size of the synthesized sample was 0.58 µm. FTIR results revealed specific absorption bands in the range of 400-4000 cm-1; optical properties are studied through UV-Vis-spectroscopy. The synthesized sample has 1.97 eV bandgap which is suitable for degradation of organic pollutants. The photocatalytic activity of the material is checked by degrading the Congo red dye under direct sunlight irradiation and for the 75 min illumination 77.8% degradation efficiency is attained.

Microfluidic fuel cells for energy generation.

Sustainable energy generation is of recent interest due to a growing energy demand across the globe and increasing environmental issues caused by conventional non-renewable means of power generation. In the context of microsystems, portable electronics and lab-on-a-chip based (bio)chemical sensors would essentially require fully integrated, reliable means of power generation. Microfluidic-based fuel cells can offer unique advantages compared to conventional fuel cells such as high surface area-to-volume ratio, ease of integration, cost effectiveness and portability. Here, we summarize recent developments which utilize the potential of microfluidic devices for energy generation.

A highly sensitive and specific tetraplex PCR assay for soybean, poultry, horse and pork species identification in sausages: development and validation.

A tetraplex PCR assay was developed for a rapid and reliable identification of horse, soybean, poultry, and pork species in sausages simultaneously. The method merges the use of horse (Equus caballus), soybean (Glycine max), poultry (Gallus gallus), and pork (Sus scrofa) specific primers that amplify small fragments (horse; 85bp, soybean; 100bp, poultry; 183bp and pork; 212bp) of the mitochondrial cyt b, lectin, 12S rRNA and ATPase subunit 6 genes respectively. Good quality DNA was isolated from reference sausage to optimize the assay. Tetraplex analysis of the reference sausage samples showed that the detection limit of the assay was 0.01% for each species. Taken together, all data indicated that this tetraplex PCR assay was a simple, rapid, sensitive, specific, and cost-effective detection method for horse, soybean, poultry, and pork species in commercial sausages.

Rapid bovine and caprine species identification in ruminant feeds by duplex real-time PCR melting curve analysis using EvaGreen fluorescence dye.

A duplex real-time PCR assay with melting curve analysis, using the EvaGreen fluorescence dye, was developed for rapid and reliable identification of bovine and caprine in ruminant feeds. The method merges the use of bovine (Bos taurus) and caprine (Capra hircus) specific primers that amplify small fragments (bovine 96 bp and caprine 142 bp) of the mitochondrial 16S rRNA and 12S rRNA genes, respectively. DNA was isolated from heat-treated meats (133 °C/3 bar for 20 min) mixtures of bovine and caprine and was used to optimize the assay. Gene products of caprine and bovine produced two distinct melting peaks simultaneously at 82 and 86.8 °C, respectively. Duplex analysis of the reference samples showed that the detection limit of the assay was 0.003 % for bovine and 0.005 % for caprine species. The aim of this study was to develop a duplex real-time PCR assay followed by a melt curve step for sensitive, rapid, specific, and cost-effective detection of bovine and caprine species based on the amplicon melting peak in ruminant feeds to prevent Transmissible Spongiform Encephalopathies.

Simultaneous identification of pork and poultry origins in pet foods by a quick multiplex real-time PCR assay using EvaGreen florescence dye.

EvaGreen multiplex real-time polymerase chain reaction (EMRT-PCR) was designed for an assay that can join the advantages of multiplex PCR and real-time PCR to recognize animal genes more quickly in pet foods. EMRT-PCR based on melting temperatures discrimination by using EvaGreen fluorescence dye was developed for the analysis of pork and poultry in pet food. The method combines the use of poultry- and pork-specific primers that amplify small fragments of 12S rRNA and mitochondrial DNA genes. Appropriate mixtures of poultry and pork meat in reference samples were used to develop the assay. Gene yields of poultry and pork were represented in two melting peaks generated simultaneously at temperatures of 80.5 and 87.2 °C, respectively. Based upon the assay results, it has been concluded that EMRT-PCR assay might be an efficient tool for the verification of species origin in pet foods.

Meningococcal disease: Clinical profile of 99 patients.

Ninety-nine patients with meningcoccal disease were admitted to the medical department of King Fahd Hospital, Medina during the Haj season of 1407H. (August 1987G). Neisseria meningitidis group A (Clone III-I) was responsible for this outbreak. This bacteria was brought into the Kingdom of Saudi Arabia by the pilgrims from South Asia who were carriers of the disease. Middle age and elderly seemed to be vulnerable to meningococcal disease. The majority of the patients presented with fever, headache, vomiting, skin rash, and signs of meningeal irritation. Diabetics afflicted with meningococcal disease fared badly; of 13 diabetics in the study, eight died. The mortality rate in our patients was 12.1%, a figure comparing favorably with other studies. The factors which influenced mortality included age above 50, shock, coma, renal failure, DIC, upper gastrointestinal bleeding, female sex and other associated diseases. The outbreak was successfully controlled by mass vaccination with polyvalent vaccine of the pilgrims and local population along with chemoprophylaxis with rifampicin.

Tc99m-renal imaging agent--the preparation and comparative clinical evaluation.

Radionuclide Tc99m DTPA (Diethylenetriaminepenta Acetic Acid) renal imaging is being used to assist in the evaluation of overall GFR, the intra-renal transit time, the cortical transit time, response to frusimide injection, diagnosis of ATN and rejection in renal transplant cases. A study was conducted at PINSTECH in order to prepare DTPA kit locally and evaluate the labeling efficiency as well as the in vitro and in vivo stability of Tc99m DTPA preparation. The results were comparable with those of imported Renal imaging (pentetate-II Technetium 99m) agent. The shelf life of the kit at room temperature recorded is around 3 months, the labeling efficiency with Tc99m pertechnetate is more than 99% and the fraction of hydrolyzed Tc99m recorded is less than 1%. On clinical trials no artifacts were seen on scintigraphic images.