Exact implicit Solution of Nonlinear Heat Transfer in Rectangular Straight Fin Using Symmetry Reduction Methods

In this paper, the exact implicit solution of the second order nonlinear ordinary differential equation which governing heat transfer in rectangular fin is obtained using symmetry reduction methods. General relationship among the temperature at the fin tip, the temperature gradient at the fin base, the mode of heat transfer, and the fin parameters and ℰ is obtained. Some numerical examples are discussed and it is shown that the temperature of fin increases when approaching from the heat source. The relationship between the fin efficiency and the temperature of fin tip is obtained for any value of the mode of heat transfer . The relationship between the fin efficiency and both the parameter and ε the temperature gradient at the fin base is obtained. To our best knowledge, solutions obtained in this paper are new

The role of losartan and enalapril in the protection against stress-induced gastric mucosal ulceration in rats

Background: Angiotensin II (ANG II) is a stress hormone and its level dramatically increases in the stomach during stress. In addition, it generates reactive oxygen species (ROS) with cellular damage and inflammation. So the aim of this study is to evaluate the mechanism of losartan and enalapril in the prevention of stress-induced gastric ulcer through their action on mucosal prostaglandin (PGs) and antioxidant enzymes and compare between them.Methods: Thirty- six adult male wistar albino rats weighing 180-200 g were divided into 6 groups; n= 6. Groups 1, 2, and 3 were received saline (normal control), losartan (3 mg/kg/day) and enalapril (10 mg/kg/day) i.p respectively for 4 weeks. Groups 4, 5, and 6 were pretreated with saline (ulcer control), losartan (3 mg/kg/day) and enalapril (10 mg/kg/day) i.p respectively for 4 weeks duration. On 29th day, group 4, 5 and 6 were submitted to gastric ulcer by water immersion method, then animals of all groups were sacrificed, stomachs were excised for gross and microscopic examination and determination of the mucosal levels of prostaglandin E2 (PGE2), superoxide dismutase (SOD), nitric oxide (NO) and catalase (CAT).Results: Stress produced gastric ulcer and a significant decrease in all measured gastric parameters compared to normal control group. Pre-treatment of rats with losartan or enalapril decreased the stress-induced alterations in mucosal parameters, but only losartan caused a significant increase in CAT activity in addition.Conclusions: Antagonize the action of ANG II by losartan and enalapril have preventive advantages in stress-induced gastric ulcer and losartan has better influence as it has an additional effect on CAT activity

Gastrografin in the management of adhesive small bowel obstruction in children: a pilot study

Background/purpose Adhesive small bowel obstruction (ASBO) is a common emergency problem in children with previous abdominal surgery. Management protocols usually start with a conservative approach that may be successful in some cases, whereas in others it will end eventually by laparotomy with its associated morbidity and mortality. Our aim was to assess the role of water-soluble contrast, gastrografin, in the conservative management of ASBO. Patients and methods During the period January 2009 to July 2010, 33 patients with ASBO were presented at the Pediatric Surgery Unit at the Ain Shams University Hospitals. Patients who failed to improve after 48 h of conservative management in the absence of signs of strangulation were subjected to gastrografin administration. Patients were evaluated clinically and radiologically to determine the resolution of the adhesive attack, with estimation of hospital stay time. Results An oral administration of gastrografin successfully completed the conservative management in eight of 12 patients (66.6%), thus avoiding surgery and subsequently reducing hospital stay. Conclusion Gastrografin may have a valuable role in the management of ASBO, whether diagnostic or therapeutic, but a randomized controlled trial is needed to prove its effectiveness in reducing surgical intervention rate and hospital stay time.Keywords: adhesive, bowel obstruction, gastrografi

Validation of RELAP5 model of experimental test rig simulating the natural convection in MTR research reactors

In an attempt to understand the buildup of natural circulation in MTR pool type upward flow research reactors after loss of power, an experimental test rig was built to simulate the loop of natural circulation in MTR reactors. In this test rig the reactor core is simulated by two electrically heated, rectangular parallel channels. The channel's coolant and surface temperature at different operating conditions were measured. The measurements and their interpretation were published by the first three authors. In the present article the thermal hydraulic behavior of the test rig is complemented by theoretical analysis using RELAP5 system code. The analysis consisting of two parts; in the first part RELAP5 model is validated against the experimental measurements and in the second part the other non-measured hydraulic parameters are presented and analyzed. In spite of the low pressure of the test rig, the results show that RELAP5 Mode 3.3 qualitatively predicts the thermal hydraulic behaviour and the accompanied phenomenon of flow inversion in such facilities. Quantitatively, there is a difference between the predicted and measured values especially the surface temperature of channel's wall. This difference may be return to the uncertainties in initial conditions of experimental runs, the position of the thermocouples which buried inside the heat structure, and the heat transfer package in RELAP5

Polycyclic Aromatic Hydrocarbons in Grilled Meats from Restaurants

Polycyclic aromatic hydrocarbons are a group of lipophilic compounds that can be generated during the preparation of food items at elevated temperatures. They are regarded as potentially genotoxic and carcinogenic to human beings, related to increased incidence of breast and colorectal cancers, oxidative DNA injury, and bad effects on children neuro-differentiation. Thus, they are considered a public health concerns. A total of thirty samples of grilled beef steak, beef kofta and chicken (ten each) were collected from different restaurants. The samples were extracted by magnesium sulfate and sodium acetate in acetonitrile then purified in magnesium sulfate, primary, secondary amine and silica gel, and finally measured by gas chromatography-mass spectrometry (GC-MS). Benzo[a]pyrene was recorded with the highest average level (3.63µg/kg) in grilled kofta samples, but it was not detected in chicken samples. On the other hand, PAH4, PAH8 and ƩPAHs content were more abundant in grilled beef steak (5.32, 9.97 and 56.91µg/kg). Meanwhile, they recorded the least concentrations of grilled chicken from different restaurants. Furthermore, benzo[a]pyrene exceeded the permissible limits of the European Commission and Egyptian National Food Safety Authority in grilled kofta samples; further studies are needed to investigate the limits of exposure to these harmful compounds from meats and other food items

Cardiac Chemical Exchange Saturation Transfer MR Imaging Tracking of Cell Survival or Rejection in Mouse Models of Cell Therapy

Purpose: To examine whether cardiac chemical exchange saturation transfer (CEST) imaging can be serially and noninvasively used to probe cell survival or rejection after intramyocardial implantation in mice. Materials and Methods: Experiments were compliant with the National Institutes of Health Guidelines on the Use of Laboratory Animals and approved by the Institutional Animal Care and Use Committee. One million C2C12 cells labeled with either europium (Eu) 10-(2-hydroxypropyl)-1,4,7-tetraazacyclododecane-1,4,7-triacetic acid (HP-DO3A) or saline via the hypotonic swelling technique were implanted into the anterior-lateral left ventricular wall in C57BL/6J (allogeneic model, n = 17) and C3H (syngeneic model, n = 13) mice. Imaging (frequency offsets of ±15 parts per million) was performed 1, 10, and 20 days after implantation, with the asymmetrical magnetization transfer ratio (MTRasym) calculated from image pairs. Histologic examination was performed at the conclusion of imaging. Changes in MTRasym over time and between mice were assessed by using two-way repeated-measures analysis of variance. Results: MTRasym was significantly higher in C3H and C57BL/6J mice in grafts of Eu-HP-DO3A–labeled cells (40.2% ± 5.0 vs 37.8% ± 7.0, respectively) compared with surrounding tissue (−0.67% ± 1.7 vs −1.8% ± 5.3, respectively; P \u3c .001) and saline-labeled grafts (−0.4% ± 6.0 vs −1.2% ± 3.6, respectively; P \u3c .001) at day 1. In C3H mice, MTRasym remained increased (31.3% ± 9.2 on day 10, 28.7% ± 5.2 on day 20; P \u3c .001 vs septum) in areas of in Eu-HP-DO3A–labeled cell grafts. In C57BL/6J mice, corresponding MTRasym values (11.3% ± 8.1 on day 10, 5.1% ± 9.4 on day 20; P \u3c .001 vs day 1) were similar to surrounding myocardium by day 20 (P = .409). Histologic findings confirmed cell rejection in C57BL/6J mice. Estimation of graft area was similar with cardiac CEST imaging and histologic examination (R2 = 0.89). Conclusion: Cardiac CEST imaging can be used to image cell survival and rejection in preclinical models of cell therapy

Evaporation induced flow inside circular wells

Flow field and height averaged radial velocity inside a droplet evaporating in an open circular well were calculated for different modes of liquid evaporation.Comment: 5 page, 3 figures, submitted to European Physical Journal

Dye Sensitized Solar Cells Based on Hydrazonoyl Synthetic Dyes

A group of chemical sensitizers of two hydrazonoyl based derivatives were synthesized. These derivatives contain a good π system for efficient light absorption and oxide sensitization. Precursor structure I was reacted with 2,6-diaminopyridine, 2-aminobenzoic acid, 4-aminobenzoic acid, 2-aminopyridine, 2,6-dinitrophenylhydrazine, and diphenylamine. The other precursor, structure (II), was reacted with 2-aminobenzoic acid, 2-amino-3-methyl, and 2-amino-4-methylpyridine. A total of 9 dyes were prepared and evaluated as sensitizers for dye-sensitized solar cells (DSSCs). Full computational calculations using DFT B3LYP 6-31+G were carried out for evaluation of band edge and band gap energies of all compounds. The absorption spectra of these dyes as well as cyclic voltammetry were used for the measurement of the HOMO, LUMO, and energy band gaps. The photovoltaic performance of the fabricated DSSCs was measured in different solutions comprising water, alcohol, phenylhydrazine, and dinitrophenylhydazine