499 research outputs found
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Flash flood simulations for an Egyptian city - mitigation measures and impact of infiltration
Within this work, the impact of mitigation measures and infiltration on flash floods is investigated by using a 2D robust shallow water model including infiltration with the Green-Ampt model. The results show the combined effects of infiltration and mitigation measures as well as the effectiveness of bypass channels in addition to retention basins. Retention basins at appropriate locations could reduce the maximum water depth at critical locations by 23%, while the additional implementation of drainage channels lead to a reduction of 75%, considering also infiltration lead to a further reduction of 97%. If infiltration was considered without mitigation measures, the peak water depth was reduced by 67%. For an exceptional extreme event the measures lead to a reduction of 73% at some locations, while at other locations the overflow from retention basins due to overstraining generated even higher inundations with an increase of 58%
Detection of grapevine closterovirus A in infected grapevine tissue by reverse transcription-polymerase chain reaction
Reverse transcription-polymerase chain reaction (RT-PCR) was successfully applied to detection of GVA RNA in nucleic acid extracts of infected grapevines. In particular, an artificially synthesized DNA primer set designed to amplify a GVA cDNA fragment of 430 base pairs, specifically detected GVA RNA sequences in extracts from infected grapevine tissues such as leaves from in vitro-grown explants, leaves from greenhouse-grown rooted cuttings, and bark scrapings of mature canes from field-grown vines. The detection limit of GVA RNA by RT-PCR was estimated to be 200 fold higher than that obtained by molecular hybridization or ELISA
Multidimensional Inverse Boundary Value Problem for a System of Hyperbolic Equations
In the paper we investigate the solvability of the inverse multidimensional boundary value problem for the system of hyperbolic type equations. A method is proposed to reduce the considered problem to some non infinite system of differential equations. The proposed method allows one to prove the existence and uniqueness theorems for the multidimensional inverse boundary value problems in the class of the functions with bounded smoothness
Plasma Catalytic Reforming of Biofuels
Vegetable oils and ethanol have been used in a plasmatron reformer to generate synthesis gas. Corn, canola, and soybean oils and ethanol have been reformed at different oxygen to carbon ratios and different power levels. Both homogeneous plasma reforming (uncatalyzed) and catalytic plasma reformer have been evaluated. I
Plasma Adrenomedullin level in Egyptian children and Adolescents with type 1 diabetes mellitus: relationship to microvascular complications
<p>Abstract</p> <p>Background</p> <p>Adrenomedullin (AM) is known to be elevated in different clinical situations including diabetes mellitus (DM), but its potential role in the pathogenesis of vascular complications in diabetic children and adolescents is to be clarified. Hence, the study aimed at assessment of plasma adrenomedullin levels in children and adolescents with type 1 DM and correlation of these levels with metabolic control and diabetic microvascular complications (MVC).</p> <p>Methods</p> <p>The study was performed in the Diabetes Specialized Clinic, Children's Hospital of Ain Shams University in Cairo, Egypt. It included 55 diabetic children and adolescents (mean age 13.93 ± 3.15 years) who were subdivided into 40 with no MVC and 15 with MVC. Thirty healthy subjects, age-and sex- matched were included as control group (mean age 12.83 ± 2.82 years). Patients and controls were assessed for glycosylated hemoglobin (HbA1c) and plasma adrenomedullin assay using ELISA technique.</p> <p>Results</p> <p>Mean plasma AM levels were significantly increased in patients with and without MVC compared to control group, (110.6 pg/mL, 60.25 pg/mL and 39.2 pg/mL respectively) (P < 0.01) with higher levels in those with MVC (P < 0.05). Plasma AM levels were positively correlated with both duration of diabetes (ρ = 0.703, P < 0.001) and glycemic control (HbA1c) (ρ = 0.453, P < 0.001).</p> <p>Conclusion</p> <p>Higher plasma AM levels in diabetics particularly in those with MVC & its correlation with diabetes duration and metabolic control may reflect the role of AM in diabetic vasculopathy in the pediatric age group.</p
Modified Mamdani-fuzzy inference system for predicting the cost overrun of construction projects
Cost overruns are a common worldwide problem in the construction industry; improved proactive risk management and cost control are much needed. Several models have been proposed, but all have weaknesses, particularly in data demands and the severity of critical risks or uncertainties associated with expert judgment. In response, this study develops a new 3-part model based on the Mamdani-type fuzzy inference system (FIS) to predict the cost overrun of construction projects. The first part assesses the weight of each expert, evaluating the severity of cost overrun factors. The second part contains a list of 40 in-built cost overrun factors and their degree of severity, while the third part establishes the relationships of every factor's occurrence probability and severity to predict the cost overrun of a specific project. The severity of each factor is assessed based on a survey of 31 randomly selected experts in the Saudi Arabian construction industry. The model is demonstrated on two completed projects in Saudi Arabia. For each project, this involves a group of project-based experts rating the probability of occurrence of each factor on that project and applying this to the factor severity list to obtain a predicted cost overrun (PCO) for the whole project. The model is validated for robustness by sensitivity analysis comparing the predicted and actual whole project cost overrun and shown to be of practical value in assessing critical risks and predicting the likely amount of cost overrun. The model is equally applicable in the early project stages.</p
Glocal integrity in 420 stainless steel by asynchronous laser processing
Cold working individual layers during additive manufacturing (AM) by mechanical surface treatments, such as peening, effectively “prints” an aggregate surface integrity that is referred to as a glocal (i.e., local with global implications) integrity. Printing a complex, pre-designed glocal integrity throughout the build volume is a feasible approach to improve functional performance while mitigating distortion. However, coupling peening with AM introduces new manufacturing challenges, namely thermal cancellation, whereby heat relaxes favorable residual stresses and work hardening when printing on a peened layer. Thus, this work investigates glocal integrity formation from cyclically coupling LENS® with laser peening on 420 stainless steel
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