Comparison between Analytical Equation and Numerical Methods for Determining Shear Stress in a Cantilever Beam

A three meter-length cantilever beam loaded with a concentrated load at its free end is studied to determine shear stresses. In the present study, three cross sections are considered: rectangle (R); I, and T. The study presents a comparison of maximum shear stresses obtained by means of two methods: classical analytical equation derived by Collingnon, and finite element method (FEM) software. Software programs ANSYS and SAP2000 were used. The results show difference between the maximum shear stresses obtained by the analytical equation and the software, being the last is always higher. The average differences for ANSYS and SAP2000, independently of the cross section, were 12.76% and 11.96%, respectively. Considering these differences, correction factors were proposed to the classical analytical formula for each cross section case to obtain more realistic results. After the correction, the average differences decrease to 1.48% and 4.86%, regardless of the cross section shape

Design and Simulation of 2×2Micro Strip Circular Patch Antenna Array at 28 GHz for 5G Mobile Station Application

This paper propose the design and simulation of 2  circular patch antenna array working at 28 GHz by using four inset feed  micro strip circular patch antennas to achieve beam forming with directivity around 13dB  which is required to overcome part of high path loss challenge for high data rate mm-5G mobile station application. Four element 2x2 array consists of two 1x2 circular patch antenna arrays based on power divider and quarter wavelength transition lines as a matching circuits. The designed  antenna array is simulated on Rogers RT 5880 dielectric substrate with properties of 0.5mm thickness, and dielectric constant =2.2 by using Computer System Technology (CST) software. The performances in terms of return loss, 3D–radiation pattern are evaluated at 28 GHz frequency band. The design also include the possibility of inserting four identical 2x2 antenna arrays at four edges of mobile station substrate to achieve broad space coverage by steering the beams of the mobile station arrays

Differential evolution algorithm for linear frequency modulation radar signal denoising

Signal denoising is directly related to sample estimation of received signals, either by estimating the equation parameters for the target reflections or the surrounding noise and clutter accompanying the data of interest. Radar signals recorded using analogue or digital devices are not immune to noise. Random or white noise with no coherency is mainly produced in the form of random electrons, and caused by heat, environment, and stray circuitry loses. These factors influence the output signal voltage, thus creating detectable noise. Differential Evolution (DE) is an effectual, competent, and robust optimisation method used to solve different problems in the engineering and scientific domains, such as in signal processing. This paper looks at the feasibility of using the differential evolution algorithm to estimate the linear frequency modulation received signal parameters for radar signal denoising. The results gave high target recognition and showed feasibility to denoise received signals

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Optimized differential evolution algorithm for linear frequency modulation radar signal denoising

In radar systems, the problem of recovering the targets reflections has been a major concern for system designers for decades. One of the first steps for better signal recovery was done by initializing a stable radar signal with high repetition sequence of generated pulses. Stabilizing the radar signal and achieving a better recovery for the received signal, over the years, took a big part of extensive studies on pulse generators and led to the era of analog systems replacement with digital ones. Using the microelectronic circuitries have shown reliability prove in terms of signal generation stability. Chirp pulses are one of the most popular radar signals that can be easily generated using digital technology. In this thesis, Memory Based, and Direct Digital Synthesizer (DDS) architectures as the two most popular chirp signal generation techniques have been designed, by using Altera StratixIII FPGA by the use of Altera QuartusII software. The received signal recording was performed by using MATLAB Software code, connected to the FPGA for getting the received reflections from the HSMC FPGA daughter board that worked as an Analog-to-Digital and Digital-to-Analog converter. Both architectures gave precise results for different selections of chirp rate that could fit with system specifications. The main contention of this thesis is to investigate the development of new optimization technique based on Differential Evolution algorithm (DE), applied for radar signal denoising application. The choose of the Differential Evolution was mainly made because, of its simplicity, and reliability scheme that can provide especially, in the applications that require continuous spaces measurements, which was fit to our problem. An improvement to the conventional DE algorithm has been made to change it from its classical form to be possibly applied for ambiguous targets range detection for radar system. The standard DE algorithm is known as a fixed length optimizer, while our problem demands the need for methods that aren’t tolerated to a fixed individual size, and that was made by altering the mutation and crossover strategies as well as the selection operation. We propose an optimized crossover scheme that changes the crossover operation from being fixed-length to random-length, which has been designed to fit for the proposed variable length DE. We refer to the new DE algorithm as random variable length crossover DE (rvlx- DE) algorithm. The measurement results show high capability for target recognition in terms of frequency response and peak forming that has been clearly recognized from noise and clutter distortion, and that was shown more clearly when it was compared with Wavelet Transform and Hilbert-Huang Transform denoising techniques

3D Printed Carbon-Fiber Filament Density Effects on Mechanical Properties

This study aims to select the suitable density of the material according to the mechanical properties needed by the 3D-printing application in which it will be used. 3D-printed carbon fiber filaments with different printing densities have been tensile, and a fatigue test was experimented with to find the mechanical properties. Furthermore, the modulus of elasticity, yield stress, and ultimate tensile strength of the material was determined by analyzing the stress-strain curves. The result shows that the parts printed with a high infill density give better mechanical properties, more time to build the object, more strength, and heavier weight than those printed with low infill density

Management of resistant hypertension

PURPOSE OF REVIEW: Resistant hypertension is defined as blood pressure above patient goal despite three different antihypertensive agents at optimal dose including a diuretic. Resistant hypertension is increasingly common issue in clinical practice and it is a major risk factor of cardiovascular disease. RECENT FINDINGS: All patients with resistant hypertension should be evaluated for possible correctable factors associated with pseudoresistance, such as poor adherence, white coat hypertension and suboptimal measurement of blood pressure. In patients with resistant hypertension, thiazide diuretics should be considered as one of the first agents, in addition to mineralocorticoids receptor antagonist. SUMMARY: Resistant hypertension can be associated with secondary cause that is why treatment can be challenging and should always include lifestyle modification and evaluation for possible secondary causes, in addition to adding a fourth agent or considering newer interventional therapies, such as renal denervation or other device-based options

Unusual product from the acid-catalyzed one-pot, multicomponent reaction of thiocarbohydrazide, aldehydes, and phenacyl bromides

A one-pot, three-component protocol for the synthesis of novel five-membered thiazole ring bonded to two hydrazone motifs is described. The acid-catalyzed reaction of one equivalent of thiocarbohydrazide, two equivalents of aromatic aldehydes, and one equivalent of phenacyl bromides afforded the five-membered thiazole ring. The reactions proceed with novel chemoselectivity. Similar reported protocols have always afforded 1,3,4-thiadiazines.The financial support of this work by the Deanship of Graduate Studies and Research at Yarmouk University is highly acknowledged (project no. 29/2014)