Investigation the properties of nanostructured materials

Elements have various characteristics that require precise tools and devices to determine each of them, EDS (Energy Dispersive Spectroscopy) system, or (Energy Dispersive X-ray Spectroscopy) EDAX or as a tool for energy dispersive spectroscopy and system ( Wavelength Dispersive X-ray Spectroscopy (WDS) is introduced as wavelength dispersive spectroscopy. These systems are used as peripheral equipment of the scanning electron microscope (SEM). In EDS spectroscopy, by measuring the energy of X-rays emitted from the sample, it is possible to examine the sample quantitatively and qualitatively. In WDS spectroscopy, the emitted X-ray waves are classified and separated based on wavelength and analyzed. Using these methods, quantitative and qualitative analyzes can be performed on the sample, and the type and amount of elements in the sample can be determined

Teacher’s instructional strategies to support slow learners in selected schools, The Islamic Republic Of Pakistan

Slow learner has been a real challenge for the teacher, especially in the early ages of schooling. This study empirically investigated the impact of instructional strategies adopted by teachers and lecturers at school and college level. Data was collected in a survey was conducted from the teachers and professors in teacher training workshop on the topic of dealing with a slow learner. Results show positive impacts of the teacher supporting instructional strategies including easy use of language, relation development with slow learner, using flexible teaching methodologies, activity based and peer based learnin

A Comparative Study of Iran’s Electricity Market Auction Mechanism and System Marginal Price Auction Mechanism

The present article discusses the impacts of selecting between different common auctions in electricity markets (system marginal price auction and pay as bid auction) on production efficiency, total efficiency and average expected price in an asymmetric information situation, where each player’s information about the marginal cost of the competitor is incomplete. A simple model is designed to conduct the comparative study of alternative auction mechanisms. The model is based on two profit maximizing players, with full information about their own marginal cost and incomplete information about their competitor. Assumptions which have been used to construct the model are based on Iran’s electricity market structure. The outcome indicates that although players bid functions in alternative auction mechanism differ from each other, the production efficiency, total efficiency and the average expected price are equivalent

Mid-term results of thoracoscopic thymectomy for myasthenia gravis

Context : Video-assisted thoracic surgery (VATS) has been proposed as a less invasive technique for treatment of myasthenia gravis. Materials and Methods : A total of 31 patients underwent a right-sided VATS to remove all anterior mediastinal fat and thymic tissue during a 4-year period in our institution. None of the patients had associated thymoma. Results : All procedures were performed successfully with no conversion to sternotomy. The mean operating time was 190 minutes. The median intubation time and assisted ventilation were 24 and 18 hours, respectively. The median ICU and hospital stays were 3 and 7 days, respectively. The median time for post-operative chest drainage was 48 hours. There was no perioperative mortality. Eight significant complications occurred. One patient had atelectasis, 1 patient had aspiration pneumonia, and 3 patients had postoperative myasthenic crisis and required prolonged mechanical ventilation. Other complications were granuloma of the vocal cord, right recurrent laryngeal nerve palsy, and temporary brachial plexus injury due to poor intraoperative positioning. The mean length of follow-up was 20 months (range: 3-42 months). Overall, 27 patients (87%) had improved clinically and 11 patients (35%) had complete remission. The resulting scars were cosmetically acceptable for all patients. Conclusion : VATS provides an effective alternative approach to thymectomy and has several advantages over open techniques. VATS causes minimal postoperative complications, shortens hospital stay, and gives better cosmetic results

Synthesis of hemoglobin F in adult simian erythroid progenitor-derived colonies.

The simian hematopoietic system is known to respond to anemic stress with the production of erythrocytes containing large amounts of fetal hemoglobin. To determine the regulatory mechanism responsible for hemoglobin F (HbF) production in stress erythropoiesis, adult simian bone marrow cells were cultured in plasma clots in the presence or absence of erythropoietin and burst-promoting activities, and the HbF content of progenitor-derived colonies was determined by radioimmunoligand assay. Three classes of erythroid progenitors were detected: BFU-E, CFU-E, and a very mature cohort of dense highly erythropoietin-responsive cells (HERC). These classes varied in inverse proportion to their maturity with respect to their potential for HbF accumulation in the colonies to which they give rise. Both erythropoietin and burst-promoting activity stimulated HbF production, particularly in colonies derived from immature progenitors. For example, under conditions of high erythropoietin stimulation, BFU-E colonies contained 13.7-37.7% HbF, CFU-E colonies contained 2.8-13.5% HbF, and HERC colonies 0-1% HbF. These results suggest that under nonstress conditions simian erythrocytes are derived almost entirely from HERC progenitors and proerythroblasts in which gamma chain synthesis is suppressed. During stress erythropoiesis, augmented HbF accumulation could be explained by the rapid entrance into the marrow of proerythroblasts directly derived from immature progenitors. Gamma chain production in these proerythroblasts is additionally regulated by the changes in environmental erythropoietin and burst-promoting activities