Optimal crew routing for linear repetitive projects using graph theory and entropy maximization metric

Construction projects that contain several identical or similar units are usually known as repetitive or linear projects. Repetitive projects are regarded as a wide umbrella that includes various categories of construction projects and represents a considerable portion of the construction industry, and contain uniform repetition of work. CPM has been proved to be inefficient in scheduling linear projects because CPM does not address two key aspects, which are maintaining crew work continuity, and achieving a constant rate of progress to meet a given deadline. Line-of-balance (LOB) is a linear scheduling methodology that produces a work schedule in which resource allocation is automatically performed to provide a continuous and uninterrupted use of resource. The fundamental principles of LOB have several shortfalls that raise many concerns about LOB, which need to be attuned and improved in order to suit the nature of construction projects. Hence, this thesis proposes a hybrid approach for scheduling linear projects that stresses on the limitation of LOB scheduling technique. To meet the physical limitation of resources in linear projects, this study presents a flexible optimization model for resolving resource constraint dilemma in linear scheduling problems .The proposed model utilizes a MATLAB code as the searching algorithm to automate the model formulation. The novelty of this model is supplementing a new optimization engine and a decision supporting system that formulate the optimal crews routing between different activities in different units and guarantee the optimal crew distribution for cost efficiency. This model investigates the mechanics of allocating a multi- task skilled workforce between different activities in different units that can lead to increased productivity, flexibility, and work continuity; besides, this model has the capability of accurately identifying the critical path in linear projects. Furthermore, to avoid day-to-day fluctuation in resource demands, this study encompasses a simulation model for handling the resource leveling in linear construction projects. The proposed model was implemented using crystal ball ribbon based on an entropy maximization metric. The entropy-maximization method accounts for such possibility of allowing activity duration to be stretched or crunched relying on activity type without affecting total completion date of a project and provides more optimized resource allocation solutions. A case study for a 4-km sewage pipeline is used to demonstrate the capability of the proposed models, which illustrates the implementation of the proposed models in construction projects

Thermal experimental dielectric characterization of cost-fewer low-density polyethylene nanocomposites

Polymer properties can be experimentally tailored by adding small amounts of different fillers, but they are expensive with respect to the classical polymer materials. This paper has been studied the enhancement and controlling of electric and dielectric properties of low-density polyethylene (LDPE) polymer materials by cost-fewer nanoparticles. Certain percentages of clay and fumed silica nanoparticles have been enhanced electric and dielectric properties of low-density polyethylene nanocomposite. Dielectric spectroscopy has been measured the electric and dielectric properties of low-density polyethylene with and without nanofillers at various frequencies (10Hz-100kHz) and temperatures (20°C, 40°C and 60°C). Also, it has been investigated the optimum percentages of nanofillers with respect to nanofillers type, filler concentration and temperature for enhancing electric and dielectric characterization of low-density polyethylene. Experimental measurements have been carried out on dielectric breakdown strength of new polyethylene nanocomposites materials under variant electric fields (uniform, and non-uniform) and variant temperatures. It has been specified the effective nanofillers factors on dielectric breakdown strength of polyethylene nanocomposites materials

Synthesis and antioxidant evaluation of some new pyridines

One-pot condensation of malononitrile (1), 4-methylpentan-2-one (2), aryl carboxaldehyde (3a-f) and ammonium acetate in ethanol afforded 2-amino-5-isopropyl-4-(4-aryl)-6-methylnicotinonitriles (4a-f). The antioxidant activity of the new synthesized compounds was evaluated and the result showed all compound exhibited weak anti-oxidant activities

Pyrrolizine-5-carboxamides: Exploring the impact of various substituents on the anti-inflammatory and anticancer activities

Towards optimization of the pyrrolizine-5-carboxamide scaffold, a novel series of six derivatives (4a-c and 5a-c) was prepared and evaluated for their anti-inflammatory, analgesic and anticancer activities. The (EZ)-7-cyano-6-((4-hydroxybenzylidene)amino)-N-(p-tolyl)-2,3-dihydro-1H-pyrrolizine-5-carboxamide (4b) and (EZ)-6-((4-chlorobenzylidene)-amino)-7-cyano-N-(p-tolyl)-2,3-dihydro-1H-pyrrolizine-5-carboxamide (5b) bearing the electron donating methyl group showed the highest anti-inflammatory activity while (EZ)-6-((4-chlorobenzylidene)amino)-7-cyano-N-phenyl-2,3-dihydro-1H-pyrrolizine-5-carboxamide (5a) was the most active analgesic agent. Cytotoxicity of the new compounds was evaluated against the MCF-7, A2780 and HT29 cancer cell lines using the MTT assay. Compounds 4b and 5b displayed high anticancer activity with IC50 in the range of 0.30–0.92 µmol L–1 against the three cell lines, while compound (EZ)-N-(4-chlorophenyl)-7-cyano-6-((4-hydroxybenzylidene)-amino)-2,3-dihydro-1H-pyrrolizine-5-carboxamide (4c) was the most active against MCF-7 cells (IC50 = 0.08 µmol L–1). Both the anti-inflammatory and anticancer activities of the new compounds were dependent on the type of substituent on the phenyl rings. Substituents with opposite electronic effects on the two phenyl rings are preferable for high cytotoxicity against the MCF-7 and A2780 cells. COX inhibition was suggested as the molecular mechanism of the anti-inflammatory activity of the new compounds while no clear relationship could be observed between COX inhibition and anticancer activity. Compound 5b, the most active against the three cell lines, induced dose-dependent early apoptosis with 0.1–0.2 % necrosis in MCF-7 cells. New compounds showed promising drug-likeness scores while the docking study revealed high binding affinity to COX-2. Taken together, this study highlighted the significant impact of the substituents on the anti-inflammatory and anticancer activity of pyrrolizine-5-carboxamides, which could help in further optimization to discover good leads for the treatment of cancer and inflammation

Insulated Solar Electric Cooker

The purpose of this Final Project Report is to highlight the work completed by the interdisciplinary engineering capstone project for the Insulated Solar Electric Cooker (ISEC) at California Polytechnic State University, San Luis Obispo under the supervision of Professor Jim Widmann (Mechanical Engineering) and Dr. Peter Schwartz (Physics). Dr. Schwartz, better known as Pete, has been working on the project with a team of students for the past five years and is working to integrate the ISEC in Ghanaian communities. This project focuses on making the ISEC mass-manufacturable and making the transition from biomass cooking to solar cooking as familiar as possible. Our concept chosen is called the Sugar Oven, which has been designed to optimize and simplify usage to be an inexpensive and easy alternative to biomass cooking. The design we chose will also feature a standardized manufacturing process and reduces risk of injury. This report features the calculations for the thermal conductivity and thermal battery and addresses the possible risks of diode failure. It also will cover the best materials to build the Sugar Oven. Due to the current nature of COVID-19, the planned building, testing, and analysis could not be done. This report instead will cover how to build the sugar oven and detailed descriptions of the tests that need to be conducted. It will lastly touch base on further research and work that can be done in furthering the development of our design

The Relationship between Serum Procalcitonin and Dialysis Adequacy in Hemodialysis Patients

Introduction: In hemodialysis (HD) patients procalcitonin (PCT) considered as an early predictor of acute infection. It represents a new and potential marker of inflammation and may correlate with dialysis adequacy. This makes procalcitonin a potential biomarker for obesity-related low-grade inflammation.Objective: The aim of the work was to assess procalcitonin level in obese prevalent hemodialysis patients and its relation to hemodialysis adequacy. Patients and Methods: A cross sectional study was conducted on 90 patients divided into 3 groups, 40 obese (BMI ≥ 30 Kg/m2) ESRD patients on regular hemodialysis (group A), 40 non obese (BMI < 25 Kg/m2) ESRD patients on regular hemodialysis (group B) attending at Dialysis Unit, El-Sahel Teaching Hospital and 10 healthy individuals with BMI < 25 Kg/m2 as a control group (group C). All patients were subjected to detailed history taking and general examination. All patients were laboratory investigated for CBC, serum urea, creatinine, CRP, urea reduction ratio (URR), equilibrated Kt/v. All controls were subjected to written informed consent, full history, examination and CRP level. Procalcitonin level was done by ELISA technique for all patients and controls.Results: In our study, we found that there was a higher level of procalcitonin (PCT) in obese hemodialysis patient than non-obese. We also found that there was no correlation between PCT and hemodialysis adequacy in our study population.Conclusion: It could be concluded that procalcitonin is a potential biomarker for obesity-related low-grade inflammation, but not related to hemodialysis adequacy

Value of Atrial Fibrillation Prophylaxis after Coronary Artery Bypass Graft Surgery

Background: Heart surgery patients who develop acute and new-onset AF (postoperative atrial fibrillation, POAF) are among the most common postoperative complications, affecting around 35 percent of those who undergo the procedure. Objective: To assess the effectiveness of amiodarone in prophylaxis of AF post coronary artery bypass surgery (CABG). Patients and Methods: Our work represents a randomized clinical trial, which was carried out at National Heart Institute and Zagazig University from the period of August 2020 to June 2021. 68 patients, admitted for CABG and had high risk score according to POAF score, were included in our study. Results: Regarding mean left ventricular ejection fraction (LVEF), in group I was 47.52±5.85 while in group II it was 49.85±6.25. There was a statistically non-significant difference between the groups with a P value of 0.414. Mean Intensive Care Unit (ICU) period was 4.42±1.35 in group I, and group II was 2.73±0.95. The difference between the groups was statistically significantly shorter among group II (prophylaxis group) (P <0.01). Regarding development of POAF, in group I, the incidence of POAF was 85.3% while in group II, it was 38.2%. Difference among the two studied groups was statistically significantly lower in the group II (prophylaxis group). Conclusion: A prophylactic amiodarone strategy dramatically decreased incidence of POAF risk. All previous estimations of POAF risk reduction using prophylactic amiodarone were found to be accurate. Amiodarone was more effective in preventing postoperative atrial fibrillation with no serious side effects and it decreased postoperative ICU stay

Synthesis and antioxidant evaluation of some new sulphadimidine incorporating thiophene moiety

A few new sulphadimidine incorporating thiophene moiety are synthesized. These compounds were assessed by analytical and spectral data. Antioxidant evaluation for the investigated compounds was evaluated by ABTS assay and bleomycin-dependent DNA-damage; the compounds exhibited weak activities