56 research outputs found

    Role of Evolutionary Algorithms in Construction Projects Scheduling

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    Due to the increase in the stakeholders and their objectives the construction projects have significantly been affected by the ongoing demands leading to increase in complexity of scheduling problems, research in the field of Multi-Objective Optimization (MOO) have increased significantly. Through their population-based search methodologies, Evolutionary Algorithms drove attention to their efficiency in addressing scheduling problems involving two or three objectives. Genetic Algorithms (GA) particularly have been used in most of the construction optimization problems due to their ability to provide near-optimal Pareto solutions in a reasonable amount of time for almost all objectives. However, when optimizing more than three objectives, the efficiency of such algorithms degrades and trade-offs among conflicting objectives must be made to obtain an optimal Pareto Frontier. To address that, this paper aims to provide a comparative analysis on four evolutionary algorithms (Genetic algorithms – Memetic algorithms – Particle Swarm – Ant colony) in the field of construction scheduling optimization, gaps are addressed, and recommendations are proposed for future research development

    Early Cerebrovascular Silent Changes in Long-Standing End-Stage Renal Disease Patients on Hemodialysis Value of Adding Advanced Unenhanced MRI Sequences to Imaging Protocols

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    Background: End-Stage Renal Disease (ESRD) patients on hemodialysis suffered from many central and peripheral neurological insults. Aim of the work:This study aimed to assess the value of using MRA, MRV, and SWAN sequences in early visualization of the silent cerebrovascular complications in those patients. Patients and Methods: Our study was conducted on forty-five patients with well-documented ESRD on regular hemodialysis for more than 5 years with no neurological manifestation, all undergone unenhanced MRI, DWI with ADC and measuring the ADC value, SWAN, MRA, and MRV. Results: we found that 11% of cases have acute infarction at the basal ganglia region. 36.7% of patients are diagnosed with intracerebral hemorrhage, only 26.7% of them are seen by the conventional MRI, and 16.7% of cases showed microbleeds on SWAN with normal conventional MRI. The sensitivity and specificity of SWAN with ADC value to detect brain hemorrhage are 100% and 88.8% respectively. Conclusion: Visualization of cerebrovascular complications such as infarction, hemorrhage, atherosclerosis, and arterial and venous occlusion using DWI with ADC, MRA, MRV, and SWAN and is very useful in early management and better prognosis of ESRD patients even with silent complications that don’t give up symptoms with high sensitivity and specificity of SWAN in early detection of hemorrhage and microbleeds

    Design and Fabrication a W-Shape Form Dual-Band Flexible Antenna For Biomedical Applications

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    This study suggests a dual band flexible antenna for use at 900 and 2450 MHz. With a footprint of 0.23 o, 0.120 o, and 0.0007 o, where o is the lowest resonance wavelength, the antenna is relatively tiny. The antenna is built from a straightforward geometrical structure consisting of a W-shaped serpentine structure supplied by a microstrip line and a partial ground plane utilizing the Defected Ground Structure (DGS) technology in order to achieve wide operational bandwidth. In order to boost resonance, an additional capacitor was inserted between the slots, creating a portable dual-band antenna. Several performance metrics\u27 findings and the ones that had been measured were compared. The antenna\u27s potential for rigid and flexible electronics is increased by its good size, bandwidth, gain, and radiation pattern

    The antiproliferative effect of mulberry (Morus alba L.) plant on hepatocarcinoma cell line HepG2

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    AbstractThis study aimed to investigate the antiproliferative effect of aqueous and organic extracts of mulberry leaves (Morus Alba L.) on human hepatocellular carcinoma HepG2 cell line. Mulberry leaf extracts were prepared using the solvents: water, 50% aqueous MeOH, and 100% MeOH for different time intervals, while the cells treated with dimethyl sulfoxide (DMSO) served as control. The effects of aqueous and organic extracts of M. alba L. leaves on HepG2 cell viability, nuclear factor kappa B (NF-κB) gene expression, alfa-fetoprotein (AFP), albumin (ALB), gamma-glutamyl transpeptidase (γ-GT) and alkaline phosphatase (ALP) were measured. The results of the cell viability assays showed that water, 50% aqueous MeOH, and 100% MeOH extracts exhibited a highly significant inhibitory effect on HepG2 cell proliferation which was evidenced by a reduction in viable cell count. The results were confirmed by microscopical examination of cell morphology. Furthermore, the mulberry leaf extracts suppressed the activity of NF-κB gene expression of HepG2 cells compared to the control. Also a highly significant depression occurred at the levels of AFP, γ-GT and ALP in HepG2 cells compared with that of controls in a time dependent manner. By contrast, the mulberry leaf extracts increased the secretion of ALB. Therefore, the conclusion was that the organic and aqueous extracts of mulberry leaves inhibit the growth of HepG2 cells through suppressing the activity of NF-κB gene expression and modulate the biochemical markers

    Neurological Alterations in Type 1 Diabetes Mellitus Among Adolescents

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    BACKGROUND: Diabetes mellitus (DM) is a group of chronic disorders of metabolism characterised by high blood glucose levels. There is an increased prevalence of Type 1 DM in children and adolescents with its adverse complications especially microvascular ones (retinopathy, nephropathy and neuropathy) that might cause multiple organ damage. AIM: To study the relation between DM and neurological affection. METHODS: Fifty-nine children with type I DM, divided randomly into 2 groups, aged 8-18 years old of both sexes were enrolled in this cross-sectional study. All children were subjected to full history taking, physical, neurological and systemic examination. RESULTS: There was an affection of motor power in both upper limbs as well as lower limbs. Also, we found that there was an affection of the superficial peripheral sensation affecting both upper and lower limbs. CONCLUSION: Neurological assessment of children with diabetes mellitus type I should be a routine to early discover these manifestations which can have a deteriorating effect on the child’s health

    Evaluating neutral, preferred, and comfort range temperatures and computing adaptive equation for Kano region

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    Provisions of international comfort standards may not be appropriate for all climates, it is therefore imperative to evaluate comfort requirements of indoor occupants in all regions, particularly where comprehensive standards are lacking. As part of an ongoing study on comfort in higher education facilities in Kano, involving lecture theatres and laboratories, an Indoor Environmental Quality field study was conducted by collecting a total of 1382 questionnaires in addition to physical measurements, covering a period of 10 months. In addition to measurements of air speed, air and radiant temperatures, relative humidity, a comfort survey was undertaken where activity levels and clothing insulations were obtained. Two neutral temperatures were arrived at based on operative and indoor running mean temperatures, 27.4 °C and 28.1 °C respectively. Similarly a comfort zone of 22 °C to 32 °C was realised. The results revealed that the adaptive equation using the weighted running mean outdoor air temperature had the highest coefficient of determination, with regression coefficient of 0.6, which is nearly twice those of ASHRAE 55 and EN 15251. The evaluated neutral and preferred temperatures show that subjects are comfortable even at 32 °C in naturally ventilated buildings in Kano regio

    Design and Analysis of Circular Polarized Two-Port MIMO Antennas with Various Antenna Element Orientations

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    This article presents the circularly polarized antenna operating over 28 GHz mm-wave applications. The suggested antenna has compact size, simple geometry, wideband, high gain, and offers circular polarization. Afterward, two-port MIMO antenna are designed to get Left Hand Circular Polarization (LHCP) and Right-Hand Circular Polarization (RHCP). Four different cases are adopted to construct two-port MIMO antenna of suggested antenna. In case 1, both of the elements are placed parallel to each other; in the second case, the element is parallel but the radiating patch of second antenna element are rotated by 180°. In the third case, the second antenna element is placed orthogonally to the first antenna element. In the final case, the antenna is parallel but placed in the opposite end of substrate material. The S-parameters, axial ratio bandwidth (ARBW) gain, and radiation efficiency are studied and compared in all these cases. The two MIMO systems of all cases are designed by using Roger RT/Duroid 6002 with thickness of 0.79 mm. The overall size of two-port MIMO antennas is 20.5 mm × 12 mm × 0.79 mm. The MIMO configuration of the suggested CP antenna offers wideband, low mutual coupling, wide ARBW, high gain, and high radiation efficiency. The hardware prototype of all cases is fabricated to verify the predicated results. Moreover, the comparison of suggested two-port MIMO antenna is also performed with already published work, which show the quality of suggested work in terms of various performance parameters over them

    Effect of Early Breast Milk Nutrition on Serum Insulin-Like Growth Factor-1 in Preterm Infants

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    BACKGROUND: Insulin-like growth factor 1 (IGF-1) is one of the essential intrauterine hormonal mediators of growth, and its serum values are often low after preterm delivery. AIM: To evaluate the influence of immediate breast milk feeding on serum IGF-1 in preterm newborns. SUBJECTS AND METHODS: This prospective, observational cohort study included 60 premature infants born < 32 weeks of gestation, divided into group A and B regarding breastfeeding or formula feeding. Growth measurements were taken at birth. The standard deviation of each measurement was calculated. Serum IGF-I was measured one day postnatal and at a time equivalent to 40 weeks of gestation. RESULTS: Significant higher level of mean serum IGF-1 was detected in group A than B at postnatal age equivalent to 40 weeks of gestation. In group A, the higher significant level was detected in mean serum IGF-1 at an age equivalent to 40 weeks of gestation than at birth (25.21 ± 6.69 and 20.13 ± 5.46 p < 0.05). Multiple linear regression analysis showed that high birth weight, increased age of gestation and breastfeeding were correlated to the elevated serum level of IGF-1 at a postnatal age corresponding to 40 weeks gestational age. CONCLUSION: Immediate breast milk feeding was accompanied by elevated IGF-1 in the serum of preterm infants

    Biomechanical aspects of reinforced implant over-dentures: a systematic review

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    AbstractPurposeThe purpose of this systematic review was to investigate the effect of reinforcement on the mechanical behaviour of implant overdenture (IOD) bases and its cumulative biological effect on the underlying supporting structures (implants and the residual ridge).Material and methodsThe required documents were collected electronically from PubMed and Web of Science databases targeting papers published in English that focused on denture base reinforcement for IOD prostheses in order to recognize the principal outcomes of reinforcement on the mechanical and biological properties of overdentures. Such biological outcomes as: strains on implants, peri-implant bone loss, residual ridge resorption, and strain on the residual alveolar ridge.ResultsA total of 269 citations were identified. After excluding any repeated articles between databases and the application of exclusion and inclusion criteria, only 13 publications fulfilled the inclusion criteria. Three publications investigated the mechanical properties of fibre and/or metal-reinforced implant overdentures while another 3 articles investigated the effect of metal reinforcement on stress distribution and strains transmitted to the underlying implants. In addition, 3 in vitro studies investigated the effect of metal reinforcement on overdenture base strain and stresses. Stress distribution to the residual ridge and strain characteristics of the underlying tissues were investigated by 2 in vitro studies. Five clinical studies performed to assist the clinical and prosthetic maintenance of metal-reinforced IOD were included. Data concerning denture base fracture, relining, peri-implant bone loss, probing depth, and implant survival rates during the functional period were extracted and considered in order to evaluate the mechanical properties of the denture base, residual ridge resorption and implant preservation rates, respectively.ConclusionThe use of a denture base reinforcement can reduce the fracture incidence in IOD bases by enhancing their flexural properties and reducing the overdenture base deformation. Strains on the underlying supporting structures of overdenture prostheses including dental implants and the residual ridge can be decreased and evenly distributed using a metal reinforcement.</div

    A parametric approach for achieving optimum daylighting performance through solar screens in desert climates

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    Daylighting provision gives a significant contribution to the enhancement of the indoor environment. However, in desert climates spaces are exposed to direct solar radiation, leading to a non-uniform daylight distribution and excessive heat gain. The literature proves that the use of a shading device may solve these problems. In this daylighting study, a parametric approach was implemented where all combinations of five screen parameters (window to wall ratio, louvers count, louvers tilt angle, screen depth ratio, and screen reflectivity) were computed. This generated 1600 different screen configurations based on the predefined range of each parameter. Two consecutive phases were performed in which the Illuminating Engineering Society (IES) metrics, Spatial Daylight Autonomy (sDA300/50%), Annual Sunlight Exposure (ASE1000/250 h), Daylight Availability as well as Annual Daylight Glare Probability (DGP), were examined. Diva-for-Rhino plug-in for Rhinoceros was used to interface Radiance and Daysim while Grasshopper plug-in for Rhinoceros was used to generate 1600 solar screen's configurations parametrically and to automate the simulation process. The simulated case study was a generic south-oriented classroom located in Cairo' desert in Egypt. A parallel computing procedure, by which multiple Radiance simulations can be run, was used to find optimal solutions. These solutions were characterized by maximum daylit area without excessive solar penetration. The general tendency of each parameter and the interaction between them was examined. Simulation results demonstrated the trend of converging solutions starting from 1:1 depth ratio with downward tilted angles. Finally, the influence of increasing screen reflectivity in enhancing daylighting performance was illustrated
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