Thermal Performance of an Air Heating Storing System

Owing to the lack of synchronization between the solar energy availability and the heat demands in a specific application, the energy storing sub-system is necessary to maintain the continuity of thermal process. The present work is dealing with an active solar heating storing system in which an air solar collector is connected to storing unit where this energy is distributed and provided to the heated space in a controlled manner. The solar collector is a box type absorber where the air flows between a number of vanes attached between the collector absorber and the bottom plate. This design can improve the efficiency due to increasing the heat transfer area exposed to the flowing air, as well as the heat conduction through the metal vanes from the top absorbing surface. The storing unit is a packed bed type where the air is coming from the air collector and circulated through the bed in order to add/remove the energy through the charging / discharging processes, respectively. The major advantage of the packed bed storage is its high degree of thermal stratification. Numerical solution of the packed bed energy storage is considered through dividing the bed into a number of equal segments for the bed particles and solved the energy equation for each segment depending on the neighbor ones. The studied design and performance parameters in the developed simulation model including, particle size, void fraction, etc. The final results showed that the collector efficiency was fluctuated between 55%-61% in winter season (January) under the climatic conditions of Misurata in Libya. Maximum temperature of 52ºC is attained at the top of the bed while the lower one is 25ºC at the end of the charging process of hot air into the bed. This distribution can satisfy the required load for the most house heating in Libya

Complete Sequences of Organelle Genomes from the Medicinal Plant Rhazya Stricta (Apocynaceae) and Contrasting Patterns of Mitochondrial Genome Evolution Across Asterids

Rhazya stricta is native to arid regions in South Asia and the Middle East and is used extensively in folk medicine to treat a wide range of diseases. In addition to generating genomic resources for this medicinally important plant, analyses of the complete plastid and mitochondrial genomes and a nuclear transcriptome from Rhazya provide insights into inter-compartmental transfers between genomes and the patterns of evolution among eight asterid mitochondrial genomes. Results: The 154,841 bp plastid genome is highly conserved with gene content and order identical to the ancestral organization of angiosperms. The 548,608 bp mitochondrial genome exhibits a number of phenomena including the presence of recombinogenic repeats that generate a multipartite organization, transferred DNA from the plastid and nuclear genomes, and bidirectional DNA transfers between the mitochondrion and the nucleus. The mitochondrial genes sdh3 and rps14 have been transferred to the nucleus and have acquired targeting presequences. In the case of rps14, two copies are present in the nucleus; only one has a mitochondrial targeting presequence and may be functional. Phylogenetic analyses of both nuclear and mitochondrial copies of rps14 across angiosperms suggests Rhazya has experienced a single transfer of this gene to the nucleus, followed by a duplication event. Furthermore, the phylogenetic distribution of gene losses and the high level of sequence divergence in targeting presequences suggest multiple, independent transfers of both sdh3 and rps14 across asterids. Comparative analyses of mitochondrial genomes of eight sequenced asterids indicates a complicated evolutionary history in this large angiosperm clade with considerable diversity in genome organization and size, repeat, gene and intron content, and amount of foreign DNA from the plastid and nuclear genomes. Conclusions: Organelle genomes of Rhazya stricta provide valuable information for improving the understanding of mitochondrial genome evolution among angiosperms. The genomic data have enabled a rigorous examination of the gene transfer events. Rhazya is unique among the eight sequenced asterids in the types of events that have shaped the evolution of its mitochondrial genome. Furthermore, the organelle genomes of R. stricta provide valuable genomic resources for utilizing this important medicinal plant in biotechnology applications.King Abdulaziz UniversityIntegrative Biolog

Speed Control of Hydraulic Elevator by Using Electro-Hydraulic Servo Mechanism

المصعد الهيدروليكي هو أحد أنواع المصاعد المستخدمة في المباني ذات الارتفاع المنخفض والذي لا يزيد عن الثلاث طوابق. في هذا البحث تم نصب وتنفيذ وتشغيل نموذج مصغر لمصعد هيدروليكي والتحقق النظري والتجريبي باستخدام صمام تناسبي، ومسيطر نوع PI. تم تنفيذ المصعد مع ثلاث طوابق بارتفاع كلي يبلغ 76 سم مع جميع المكونات والملحقات الهيدروليكية والكهربائية، حيث ان اتمتة المصعد كانت باستخدام مايكرو كونترولر اردوينو ِArduino نوع أونو. UNO برنامج الحاسوب اللابفيو LABVEIW تم استخدامه للسيطرة على المصعد من خلال مسوق التيار المستمر L298 DC. أفضل قيم لباراميترات المسيطر PI تم الحصول عليها تجريبيا. النتائج أظهرت دعم وتحسين الأداء للمصعد الهيدروليكي من خلال استخدام نظام المؤازرة الكهروهيدروليكي لتحقيق التوقف السلس وراحة المستخدمين للمصعد في التنقل بحركة انسيابية بين الطوابق.An electro-hydraulic elevator is a new type of enhanced elevators used in low-rise buildings, no more than eight floors. In this paper, an electro-hydraulic servo system for controlling the speed of a hydraulic elevator prototype by using a proportional valve and PI controller has been investigated theoretically and experimentally. A three floors elevator prototype model with 76cm height has been built, including hydraulic components and electrical components. The elevator system is automated using an Arduino UNO board based Data Acquisition (DAQ) system. LabVIEW software is programmed to control the hydraulic elevator system through L298 DC drive via the DAQ board. The best PI gains have been calculated experimentally using Ziegler–Nichols, trial and error methods. The results showed the effectiveness of the use of Electro-hydraulic servomechanism in enhancing the performance of the hydraulic elevator in terms of comfort and smoothness when people travelled through the elevator floors

Evolutionary Computation in Coded Communications: an Implementation of Viterbi Algorithm

Non

Biosurfactant as the next antimicrobial agents in pharmaceutical applications

The number of patients with antimicrobial resistance is growing as a result of new emerging microbes or overuse of antibiotics. A new substitute to the existing antimicrobial agents is important in time to come to control the mortality rate in the global population. Natural substances, like biosurfactants or commonly known as microbial surfactants could be a potential antimicrobial agent to medical personnel’s consideration as some biosurfactants exhibits antimicrobial activity. Hence, this paper will briefly highlight some of the findings from contemporary researchers who have tested different biosurfactants for potential antimicrobial activity

Chronic Salt Loading and the Expression of Adenosine Receptor Subtypes

N/

Simplex and triplex polymerase chain reaction (PCR) for identification of three medically important Candida species

Candida species are a major cause of invasive infections in both critically ill and immunocompromised patients. Hence, rapid identification of these pathogens may facilitate specific therapy and patient management. The development of rapid and specific diagnostic methods remains a challenge. Herein, we developed the simplex and triplex polymerase chain reaction (PCR) for the identification of three medically important Candida species namely C. albicans, C. parapsilosis and C. tropicalis. The developed methods target the phospholipase B gene (PLB). The primers designed achieved highly specific identification of the selected species using both the simplex PCR and the triplex PCR formats, which were confirmed by DNA sequencing. The primers did not show any non-specific amplification when tested with DNA from other Candida species and other fungal species such as Aspergillus and Cryptococcus. These results showed that the PLB gene provides a novel target that could be used for the detection of medically important Candida species from clinical specimens.Key words: Candida species, primers, phospholipase B gene (PLB), polymerase chain reaction (PCR)

Fisheries Education and Research in Bangladesh

With the increase of population and depletion of fisheries resources due to loss of fish growing land to agriculture, siltation, etc it became necessary to develop an institutional set-up for fisheries education and research. A number of educational institutes have been established in Bangladesh and every year a number of graduates are coming out from these institutes. In addition, various research and development institutes have also conducted fruitful research for the upliftment of fisheries sector to meet the increasing demand for fish in Bangladesh. The present study is conducted to explore how these institutes play a role in fisheries education and research. This paper highlights training requirements and future plan of the government of Bangladesh for fisheries education and research. The researchers also tried to identify the constraints in fisheries research and education and suggested few probable suggestions for the government and other relevant parties for the ultimate benefit of the fisheries sector.Keywords: Education and Research, Institutional Set-Up, Constraints, Fisheries Resources, Future Plan, Trainin

Angiotensin II stimulation alters vasomotor response to adenosine in mouse mesenteric artery: role for A1 and A2B adenosine receptors.

BACKGROUND AND PURPOSE: Stimulation of the A1 adenosine receptor and angiotensin II receptor type-1 (AT1 receptor) causes vasoconstriction through activation of cytochrome P450 4A (CYP4A) and ERK1/2. Thus, we hypothesized that acute angiotensin II activation alters the vasomotor response induced by the non-selective adenosine receptor agonist, NECA, in mouse mesenteric arteries (MAs). EXPERIMENTAL APPROACH: We used a Danish Myo Technology wire myograph to measure muscle tension in isolated MAs from wild type (WT), A1 receptor and A2B receptor knockout (KO) mice. Western blots were performed to determine the expression of AT1 receptors and CYP4A. KEY RESULTS: Acute exposure (15 min) to angiotensin II attenuated the NECA-dependent vasodilatation and enhanced vasoconstriction. This vasoconstrictor effect of angiotensin II in NECA-treated MAs was abolished in A1 receptor KO mice and in WT mice treated with the A1 receptor antagonist DPCPX, CYP4A inhibitor HET0016 and ERK1/2 inhibitor PD98059. In MAs from A2B receptor KO mice, the vasoconstrictor effect of angiotensin II on the NECA-induced response was shown to be dependent on A1 receptors. Furthermore, in A2B receptor KO mice, the expression of AT1 receptors and CYP4A was increased and the angiotensin II-induced vasoconstriction enhanced. In addition, inhibition of KATP channels with glibenclamide significantly reduced NECA-induced vasodilatation in WT mice. CONCLUSIONS AND IMPLICATIONS: Acute angiotensin II stimulation enhanced A1 receptor-dependent vasoconstriction and inhibited A2B receptor-dependent vasodilatation, leading to a net vasoconstriction and altered vasomotor response to NECA in MAs. This interaction may be important in the regulation of BP

Remission of hypertension after treatment of giant simple renal cyst: a case report

Renal cysts are common in old patients, and usually remain untreated. Giant renal cysts measuring more than 15 cm in greatest diameter are uncommon and the association with hypertension is very rare. We present a case of a 25-year-old woman with a giant right renal cyst associated with hypertension that was treated by laparoscopic excision, followed by resolution hypertension