Discontinuous Galerkin for the wave equation: a simplified a priori error analysis

Standard discontinuous Galerkin methods, based on piecewise polynomials of degree \qq\geq 0, are considered for temporal semi-discretization for second order hyperbolic equations. The main goal of this paper is to present a simple and straight forward a priori error analysis of optimal order with minimal regularity requirement on the solution. Uniform norm in time error estimates are also proved for the constant and linear cases. To this end, energy identities and stability estimates of the discrete problem are proved for a slightly more general problem. These are used to prove optimal order a priori error estimates with minimal regularity requirement on the solution. The combination with the classic continuous Galerkin finite element discretization in space variable is used, to formulate a full-discrete scheme. The a priori error analysis is presented. Numerical experiments are performed to verify the theoretical rate of convergence.Comment: 23 pages, 1 figur

A comparison of antibiotic disks from different sources on Quicolor and Mueller-Hinton agar media in evaluation of antibacterial susceptibility testing

Background and Objectives: Antibacterial susceptibility testing of clinical bacterial isolates through disk diffusion method plays a major role in antibacterial treatment. One of the main factors affecting the result of these tests is the type, structure and quality of the disks. The main objective of this study was to compare the agreement of antibiotic disks originated from three companies on Quicolor and Mueller-Hinton agar. Materials and Methods: Quicolor and Mueller-Hinton agar media were used in disk diffusion method. Seventy clinical isolates from Enterobacteriaceae family (21 Klebsiella spp., 36 Escherichia coli, 1 Enterobacter spp. and 12 Shigella spp.) were investigated in the study. After obtaining data, the results were interpreted as resistant, sensitive or intermediate. Kappa coefficient measured the agreement of two media. Coefficient of variation (CV) was also calculated for antibiotic disks. Results: The kappa agreement values for three types of antibiotic disks on Quicolor and Mueller-Hinton agar plates were good or excellent for all the examined antibiotics. CV values were also very satisfactory in the majority of cases. Conclusion: Antibiotic disks from three manufacturers can successfully be used on both Quicolor and Mueller-Hinton agar plates

Design and Implementation of Low Power SRAM Using Highly Effective Lever Shifters

The explosive growth of battery-operated devices has made low-power design a priority in recent years. In high-performance Systems-on-Chip, leakage power consumption has become comparable to the dynamic component, and its relevance increases as technology scales. These trends are even more evident for SRAM memory devices since they are a dominant source of standby power consumption in low-power application processors. The on-die SRAM power consumption is particularly important for increasingly pervasive mobile and handheld applications where battery life is a key design and technology attribute. In the SRAM-memory design, SRAM cells also comprise the most significant portion of the total chip. Moreover, the increasing number of transistors in the SRAM memories and the MOSs\u27 increasing leakage current in the scaled technologies have turned the SRAM unit into a power-hungry block for both dynamic and static viewpoints. Although the scaling of the supply voltage enables low-power consumption, the SRAM cells\u27 data stability becomes a major concern. Thus, the reduction of SRAM leakage power has become a critical research concern. To address the leakage power consumption in high-performance cache memories, a stream of novel integrated circuit and architectural level techniques are proposed by researchers including leakage-current management techniques, cell array leakage reduction techniques, bitline leakage reduction techniques, and leakage current compensation techniques. The main goal of this work was to improve the cell array leakage reduction techniques in order to minimize the leakage power for SRAM memory design in low-power applications. This study performs the body biasing application to reduce leakage current as well. To adjust the NMOSs\u27 threshold voltage and consequently leakage current, a negative DC voltage could be applied to their body terminal as a second gate. As a result, in order to generate a negative DC voltage, this study proposes a negative voltage reference that includes a trimming circuit and a negative level shifter. These enhancements are employed to a 10kb SRAM memory operating at 0.3V in a 65nm CMOS process

Comparing the effect of Anethum gravolens with mefenamic acid consumption on treatment of primary dysmenorrhea

زمینه و هدف : دیسمنوره اولیه یکی از شایع‌ترین شکایات در زنان می‌باشد و حداقل 50 زنان در خلال دوره باروری خود آن را تجربه می کنند. پژوهش حاضر با هدف مقایسه تأثیر مصرف عصاره گیاه شوید با مفنامیک اسید در درمان دیسمنوره اولیه انجام شده است. روش بررسی : این کارآزمایی بالینی بر 100 دانشجوی مبتلا به دیسمنوره اولیه با شدت متوسط و محصل در دانشگاه های ایرانشهر در سال 1389 انجام شد. نمونه گیری به روش دو مرحله ای صورت گرفت و نمونه ها با روش تخصیص تصادفی به دو گروه مفنامیک اسید و عصاره گیاه شوید تقسیم شدند. در ابتدای سیکل، برای گروه عصاره شوید، قطره دیل سان 10 قطره هر 8 ساعت در روز و برای گروه دیگر کپسول مفنامیک اسید 250 میلی گرم هر 6 ساعت در روز بعد از شروع درد، تجویز شد و شدت درد در سیکل قبل از مداخله و سه سیکل (ماه) بعد از مداخله در هر گروه و در دو گروه با یکدیگر مقایسه شد. نتایج در نرم افزار SPSS و استفاده از آزمون های آماری کای دو، آنالیز واریانس یک طرفه و تی تست در سطح معنی داری 05/0 آنالیز شدند. یافته ها: میانگین شدت درد قبل از مداخله در دو گروه معنی دار نبود (42/0 (P= . بعد از مداخله، در هر سه سیکل در دو گروه مورد بررسی کاهش درد وجود داشته است که این کاهش در گروه مفنامیک اسید بیشتر بوده و در سیکل دوم و سوم معنی دار بوده است (05/0 > .(P نتیجه گیری : عصاره گیاه شوید و مفنامیک اسید بر دیسمنوره موثر بودند. گرچه این تأثیر در گروه مفنامیک اسید بیشتر بود؛ اما با توجه به کمتربودن عوارض داروهای گیاهی و علاقه بیشتر عموم به مصرف آن ها، عصاره شوید جهت درمان دیسمنوره توصیه می شود

Biological and therapeutic properties of Bee pollen

Introduction: Bee pollen is a natural honeybee product promoted as a valuable source of nourishing substances and energy. Bee pollen contains several nutrients and bioactive compounds: proteins, which are among the main components of Bee pollen, include enzymes and both essential and nonessential amino acids. In fact, Bee pollen is referred to as the “only perfectly complete food”, as it contains all the essential amino acids needed for the human organism. A large number of carbohydrates, lipids, sugars, fibers, vitamins and mineral salts are also found in this substance. The health-enhancing value of bee pollen is expected due to the wide range of secondary plant metabolites such as tocopherol, thiamine, biotin, polyphenols, carotenoid pigments, phytosterols. It has many beneficial effects such as antioxidant, anti-inflammatory, anti-carcinogenic, antibacterial, antifungal, hepatoprotective, anti-atherosclerotic and immune enhancing. So there are many therapeutic goals for Bee pollen. Methods and Results: This article is based on different original articles on PubMed‚ and ScienceDirect data bases.  Almost 50 articles have been studied that 20 of them were really useful in writing this abstract. Bee pollen has many beneficial effects like antioxidant, anti-inflammatory, anti-carcinogenic, antibacterial, antifungal, hepatoprotective, anti-atherosclerotic, anti-estrogenic and immune enhancing activity. It also can be used as a promising agent in the burn Wounds treatment. Conclusions: Bee pollen as a natural honeybee product؛ has a lot of biological and therapeutic effects. It is useful for treatment of many diseases. In principle, we can unequivocally recommend bee pollen as a valuable dietary supplement. Also, the bee-pollen components have potential bioactive and therapeutic properties. Extensive research is required before bee pollen can be used in therapy

The Role of Protamine in Male Fertility

Background: Approximately 40-50% of infertilities is related to males. Abnormal sperm chromatin structure is suggested as a significant cause of infertility. Protamines constitute a significant component of the sperm chromatin, and they play a vital role in the proper packaging of chromatin. Numerous studies have shown that protamine deficiency in sperm is associated with low sperm quality and infertility. Given the importance of protamine infertility, the purpose of this article is to investigate the content of protamine and its biological importance in male fertility. Materials and Methods: In this study, data and information collected on English-language articles from PubMed and MEDLINE databases. For Persian articles, Persian-language databases, including SID Scientific Database, IranMedex Medical Articles Database, IranDoc (Iran Scientific Information and Documents Research Institute), Magiran Publication Information and MedLib investigated. Results: Based on previous studies about protamine and its role in spermatogenesis, any disruption in protamine genes, including PRM1 and PMR2, can disrupt histone/protamine ratio, leading to abnormal spermatozoa. Conclusion: Most the previous studies approved any mutation in protamine genes correlates with infertility in men. These results can be a potential subject for future researches into infertility treatment in men

Estimation of Levelized Costs of Electricity Generation in Renewable and Fossil Power Plants

The existence of a comprehensive model that enables the calculation of the real price of electricity production along with its environmental costs is one of the most important analytical tools in energy economics. It is now different from when virtual water costs and other environmental costs of power generation are taken into account. In this article, information from 56 power plants across the country was used. In this paper, an algorithm for calculating the Levelized Cost of Electricity (LCOE) is presented. Among these, common technologies in the production sector, including heating, gas, combined cycle, wind, and photovoltaic power plants, have been studied from an economic perspective and the results of calculating their cost price have been presented. The results show that the highest costs are related to electricity generation using gas technology (18.86 cents per kilowatt hour with subsidized fuel and 35.98 cents per kilowatt hour with exported fuel) and the lowest cost of generating electricity through a wind farm is 6.59 cents per kilowatt hour. In the calculations, the cost of fuel in the form of subsidies and exports and the cost of virtual water in the production process are also considered. One of the reasons for the slow growth of renewable energy development is that the fuel price of gas and oil for power plants in Iran was not realistic despite the fuel subsidy, so electricity production in thermal power plants is cost-effective and electricity production from renewable energies such as wind and photovoltaic power plants in a superficial view has no economic justification.

Effects of Y chromosome Microdeletions on Male Fertility

Background: In the process of human reproduction, spermatogenesis is one of the most important stages, which is controled by special genes on Y chromosome. Previous studies show that some infertile men have microdeletions on Y chromosome, which cause the reduction of sperm count. Three prominent spermatogenesis loci have been identified on the Y chromosome and entitled “azoospermia factors” (AZFa, b, and c). Hereby, this review article aimed to investigate the content of the Y chromosome microdeletions and their importance in male fertility. Methods: Data and information were collected on English-language articles from PubMed and MEDLINE databases. For Persian articles, Persian-language databases, including SID Scientific Database, IranMedex Medical Articles Database, IranDoc (Iran Scientific Information and Documents Research Institute), Magiran Publication Information, and MedLib were investigated. More than 50 articles on Y chromosome microdeletions and infertility published during 2000-2020 were studied. Results: Previous studies implicated that Y chromosome microdeletions in AZFa, AZFb, and AZFc regions are accompanied by defect in spermatogenesis, leading to oligo / azoospermia. Patients with AZFa and AZFb microdeletions present secretory azoospermia and do not have sperm in their seminiferous tubules. Complete AZFc deletion involves region b2/b4, which contains a total of 12 genes. Incomplete deletion of AZFc includes b1/b3, b2/b3 and gr/gr. The most common of which are gr/gr. In men with gr/gr deletion, sperm count and motility were lower than control group. Conclusion: Y chromosomal microdeletions emerged as the most frequent structural chromosome anomaly associated with the quantitative reduction of sperm. The development of assisted reproductive techniques (ART) like intra-cytoplasmic sperm injection (ICSI) and testicular sperm extraction (TESE) helps to bypass the natural barriers of fertilization

Polymer/Inorganic Hole Transport Layer for Low-Temperature-Processed Perovskite Solar Cells

In the search for improvements in perovskite solar cells (PSCs), several different aspects are currently being addressed, including an increase in the stability and a reduction in the hysteresis. Both are mainly achieved by improving the cell structure, employing new materials or novel cell arrangements. We introduce a hysteresis-free low-temperature planar PSC, composed of a poly(3-hexylthiophene) (P3HT)/CuSCN bilayer as a hole transport layer (HTL) and a mixed cation perovskite absorber. Proper adjustment of the precursor concentration and thickness of the HTL led to a homogeneous and dense HTL on the perovskite layer. This strategy not only eliminated the hysteresis of the photocurrent, but also permitted power conversion efficiencies exceeding 15.3%. The P3HT/CuSCN bilayer strategy markedly improved the life span and stability of the non-encapsulated PSCs under atmospheric conditions and accelerated thermal stress. The device retained more than 80% of its initial efficiency after 100 h (60% after 500 h) of continuous thermal stress under ambient conditions. The performance and durability of the PSCs employing a polymer/inorganic bilayer as the HTL are improved mainly due to restraining perovskite ions, metals, and halides migration, emphasizing the pivotal role that can be played by the interface in the perovskite-additive hole transport materials (HTM) stack