Compherensive design of a 100 kW/400 V high performance AC-DC converter

In this paper, a comprehensive design for a 100kW/400V, three-phase pulse-width modulated (PWM) AC-DC converter is presented that serves as the front-end power supply for wide-range varying active load. This power supply includes two series stages; a six-switch AC-DC boost converter and a DC-DC buck converter to regulate 400VDC at load side. The design of all inductors and capacitors is fulfilled using mathematical expressions. In addition, small signal modelling and controller design are presented in order to raise the design efficiency of the proposed converter. Also, due to the high power application, improved soft-switching techniques are applied. Furthermore, systematic approach to design an input EMI filter for DC-DC converter is explained. The simulation results performed by PSCAD software show that high performance of the proposed power supply is obtained in terms of stability, high power factor, high efficiency and low total harmonic distortion (THD)

Modified Carbon Nanotube Paste Electrode for Voltammetric Determination of Carbidopa, Folic Acid, and Tryptophan

A simple and convenient method is described for voltammetric determination of carbidopa (CD), based on its electrochemical oxidation at a modified multiwall carbon nanotube paste electrode. Under optimized conditions, the proposed method exhibited acceptable analytical performances in terms of linearity (over the concentration range from 0.1 to 700.0 μM), detection limit (65.0 nM), and reproducibility (RSD = 2.5%) for a solution containing CD. Also, square wave voltammetry (SWV) was used for simultaneous determination of CD, folic acid (FA), and tryptophan (TRP) at the modified electrode. To further validate its possible application, the method was used for the quantification of CD, FA, and TRP in urine samples

A Data-Driven Model with Hysteresis Compensation for I2RIS Robot

Retinal microsurgery is a high-precision surgery performed on an exceedingly delicate tissue. It now requires extensively trained and highly skilled surgeons. Given the restricted range of instrument motion in the confined intraocular space, and also potentially restricting instrument contact with the sclera, snake-like robots may prove to be a promising technology to provide surgeons with greater flexibility, dexterity, space access, and positioning accuracy during retinal procedures requiring high precision and advantageous tooltip approach angles, such as retinal vein cannulation and epiretinal membrane peeling. Kinematics modeling of these robots is an essential step toward accurate position control, however, as opposed to conventional manipulators, modeling of these robots does not follow a straightforward method due to their complex mechanical structure and actuation mechanisms. Especially, in wire-driven snake-like robots, the hysteresis problem due to the wire tension condition can have a significant impact on the positioning accuracy of these robots. In this paper, we proposed an experimental kinematics model with a hysteresis compensation algorithm using the probabilistic Gaussian mixture models (GMM) Gaussian mixture regression (GMR) approach. Experimental results on the two-degree-of-freedom (DOF) integrated robotic intraocular snake (I2RIS) show that the proposed model provides 0.4 deg accuracy, which is an overall 60% and 70% of improvement for yaw and pitch degrees of freedom, respectively, compared to a previous model of this robot

First record of Lebia syriaca (Carabidae, Lebiini) for Iran and additional faunistic notes on Carabidae from south-west Iran

Ahmadi, Marzieh, Esfandiari, Mehdi, Muilwijk, Jan, Ostovan, Hadi (2017): First record of Lebia syriaca (Carabidae, Lebiini) for Iran and additional faunistic notes on Carabidae from south-west Iran. Linzer biologische Beiträge 49 (1): 265-273, DOI: http://doi.org/10.5281/zenodo.535680

Market Pricing for Data Streams

Internet-enabled marketplaces such as Amazon deal with huge datasets registering transaction of merchandises between lots of buyers and sellers. It is important that algorithms become more time and space efficient as the size of datasets increase. An algorithm that runs in polynomial time may not have a reasonable running time for such large datasets. Here, we study the development of pricing algorithms that are appropriate for use with massive datasets. We especially focus on the streaming setting, the common model for big data analysis. We present an envy-free mechanism for social welfare maximization problem in the streaming setting using O(k2 l) space, where k is the number of different goods and l is the number of available items of each good. We also provide an α-approximation mechanism for revenue maximization in this setting given an α-approximation mechanism for the corresponding offline problem exists. Moreover, we provide mechanisms to approximate the optimum social welfare (or revenue) within 1 – ε factor, in space independent of l which would be favorable in case l is large compared to k. Finally, we present hardness results showing approximation of optimal prices that maximize social welfare (or revenue) in the streaming setting needs Ω(l) space. We achieve our results by developing a powerful sampling technique for bipartite networks. The simplicity of our sampling technique empowers us to maintain the sample over the input sequence. Indeed, one can construct this sample in the distributed setting (a.k.a, MapReduce) and get the same results in two rounds of computations, or one may simply apply this sampling technique to provide faster offline algorithms

Application of intelligent packaging for meat products: A systematic review

Abstract Background Today, in response to consumer demand and market trends, the development of new packaging with better performance such as intelligent packaging has become more important. This packaging system is able to perform intelligent functions to increase shelf life, increase safety and improve product quality. Objectives Recently, various types of packaging systems are available for meat products, especially cooked, fresh and processed meats. But because meat products are very perishable, monitoring their quality and safety in the supply chain is very important. This systematic article briefly reviews some of the recent data about the application of intelligent packaging in meat products. Methods The search was conducted in Google Scholar, Science Direct, Elsevier, Springer, Scopus, and PubMed, from April 1996 to April 2021 using a different combination of the following keyword: intelligent packaging, and meat. Results The results showed that the intelligent packaging presents several benefits compared to traditional packaging (e.g., antimicrobial, antioxidant, and shelf life extension) at the industrial processing level. Thus, these systems have been applied to improve the shelf life and textural properties of meat and meat products. Conclusions It is necessary to control the number of intelligent compounds that are included in the packaging as they clearly influence the quality and nutritional properties as well as the final cost of the food products

Firework-related injuries in Tehran's Persian Wednesday Eve Festival (Chaharshanbe Soori)

Background: Fireworks are the leading cause of injuries such as burns and amputations during the Persian Wednesday Eve Festival (Chaharshanbeh Soori). Objectives: This study was designed to explore the age of the high-risk population, the type of fireworks most frequently causing injury, the pattern of injury, and the frequency of permanent disabilities. Methods: This cohort study was performed by Tehran Emergency Medical Services at different medical centers all around Tehran, Iran, in individuals referred due to firework-related injuries during 1 month surrounding the festival in the year 2007. The following information was extracted from the patients' medical records: demographic data, the type of fireworks causing injury, the pattern and severity of the injury, the pre-hospital and hospital care provided for the patient, and the patient's condition at the time of discharge. In addition, information on the severity of the remaining disability was recorded 8 months after the injury. Results: There were 197 patients enrolled in the study with a mean age of 20.94 +/- 11.31 years; the majority of them were male. Fuse-detonated noisemakers and homemade grenades were the most frequent causes of injury. Hand injury was reported in 39.8% of the cases. Amputation and long-term disability were found in 6 and 12 cases, respectively. None of the patients died during the study period. Conclusion: The fireworks used during a Chaharshanbeh Soori ceremony were responsible for a considerable number of injuries to different parts of the body, and some of them led to permanent disabilities. (C) 2011 Elsevier Inc

Factors Related to Reduced Bone Density in β-Thalassemia Major Patients: Mazandaran Thalassemia Registry

Introduction: OsteoPenia and osteoPorosis are known to be one of the main comPlications of β-thalassemia major (β-TM). The aim of this study was to determine the factors associated with decreased bone density of these Patients. Methods: Lumbar and femoral neck bone mineral density (BMD) in β-TM Patients characterized via Dual-energy X-ray absorPtiometry (DXA) to PinPoint the association of iron chelators, diabetes mellitus, serum ferritin above 3000 ng/mL, hemoglobin below 8 gr/dl, using hydroxyurea, liver siderosis and moderate to severe hePatic and cardiac siderosis with BMD. The information was collected from the thalassemia registry in 2019 and statistical analysis was Performed by STATA-13 software. Results: Out of 1959 ParticiPants with β-thalassemia major registered in the registry, 139 ones (7.09%) had bone mineral density (53 males and 86 females). The Prevalence of abnormal bone density in the lumbar and femoral neck was (52.48 to 47.66) 57.5 and (40.18 to 57.52) 48.85 Percent, resPectively. After adjusting for the effects of Possible interventions, the odds ratio of abnormal bone density in the Patients consuming hydroxyurea and deferasirox were 0.24 (0.03 to 1.73) and 0.25 (0.03 to 1.69), resPectively. The highest odds were 8.21 (0.18 to 360.22), and 6.72 (0.60 to 74.83) for moderate to severe cardiac and hePatic dePosition, resPectively. Conclusion: The Prevalence of osteoPenia and osteoPorosis is high among thalassemia major Patients. ConsumPtion of hydroxyurea and deferasirox is the most imPortant Protective factor and moderate to severe cardiac and hePatic siderosis are the most imPortant risk factors for abnormal bone density