MATHEMATICAL MODELING OF THE DESTABILIZATION OF ACID IN CRUDE OIL EMULSIONS USING POPULATION BALANCE EQUATION

In this current work, a phenomenological mathematical model that utilizes the population balance equation was developed to understand the destabilization process of acid in crude oil emulsions in laboratory conditions. The model considers changes due to advection, diffusion and binary coalescence of the dispersed acid phase. The model studies specifically the evolution of the droplet size distribution as a function of time for the top, next to bottom and bottom layers of a vertical cylinder. The resulting model was a nonlinear hyperbolic intergo-partial differential equation. As with many complex mathematical models, this model required a numerical solution. The source term modeling birth and death of droplets was numerically solved using Kumar’s fixed-pivot technique and converted to a system of partial differential equations. As for the advection-diffusion transport properties, five numerical solutions were examined each suitable under certain model properties. Four of the techniques were standard upwind schemes that are second, third and fourth order accurate, and the fifth was a non-standard method. All these schemes were also optimized to reduce the numerical errors to almost negligible. The non-standard method proved to be superior to the traditionally used upwind schemes for fine and course grids and low and high Reynolds numbers. Based on this algorithm, the numerical model was solved using initial literature experimental data for acid/oil emulsions and was able to provide a suitable prediction of droplet size distribution profiles for each of the three layers of interest in addition to both dispersed and continuous phase volumes. The model was also found to be a good predictive tool for the initial mean droplet size for early acid/oil emulsion days using an exponential regression model for each time step. The volume fraction of acid was found to be highly sensitive to changes in mean droplet size but was inconclusive in accessing the effect of standard deviation on the model evolution. The proposed algorithm has also presented evidence of the presence of a cohesive process dominating the system alongside the destabilization process of advection, diffusion and binary coalescence

Ruling on Zakat on Digital Currencies Rooted in the Noble Qur'an and the Prophet's Sunnah

Praise be to God, Lord of the worlds, who guided us and brought us out of darkness into light, and prayers and peace be upon the messenger as a mercy to the worlds, who delivered the message and advised the nation, and all his family and companions. Digital currencies are one of the modern calamities that many people wonder about, some are confused about, and many wonder how to deal with them. Is it an illusion or reality? Most of the dealers of digital currencies wonder about its legal ruling and whether the provisions that apply to money issued by official state banks also apply to it. Therefore, the research aims to clarify the ruling on zakat on digital currencies from the perspective of the Noble Qur'an and the purified Sunnah of the Prophet. Keywords: digital currencies, zakat

CHANGES IN SOME BIOPHYSICAL AND BIOCHEMICAL PARAMETERS IN BLOOD AND URINE OF WORKERS CHRONICALLY EXPOSED TO BENZENE

Objective: Benzene may occur naturally as a component of petroleum, or may be manufactured synthetically. It is found in the environment as a contaminant from both human activities and natural processes, posing serious bio-hazards from chronic exposure.Methods: A total of 330 individual were enrolled to study possible health hazards of benzene contamination; 265 males occupationally chronically exposed to low levels of benzene in their daily activity were compared to 65 healthy individuals of the same socio-economic standard. Benzene workers were divided between 45 workers in printing shops, 70 subjects dealing with benzene containing paints (painters), 75 subjects working in professions related to automotive work (autoworkers) and 75 car drivers.Results: benzene itself was not detected in blood or urine of all participants, but the levels of its metabolites; phenol and t,t-muconic acid, were higher in the blood and urine samples in the group of benzene-exposed workers. The results also indicate that individuals in this group are under oxidative stress. However, neither the determined liver function nor the kidney function tests showed significant deviation from controls. However, the results of the biophysical hematological parameters, including the degree of hemolysis, blood viscosity, RBCs aggregation and form factor were significantly deviated from normal.Conclusion: The deviation of the determined biochemical and biophysical parameters from normal may predispose such workers to a variety of health problems. Early correction of the oxidative stress and the hematological parameters and improvement of working conditions are necessary to prevent their progress to more serious health conditions, especially in children and young adolescents working under similar conditions.Running Title : Chronic exposure to benzene in work plac

Immunophenotyping of chronic B-cell neoplasms: flow cytometry versus immunohistochemistry

Morphological differentiation between benign and malignant lymphoproliferative disorders (LPDs) can be challenging. Immunophenotyping (IPT) by either technique, flow cytometry or immunohistochemistry (IHC), is an important step in solving such difficulty. Thirty-five newly diagnosed patients with chronic B-cell neoplasms (11 chronic lymphocytic leukemia, 22 non Hodgkin lymphoma and 2 hairy cell leukemia) were included in this study with age range from 20 to 70 years. Monoclonal antibodies surface expression using lymphoproliferative disorders panel (CD45, CD19, CD5, CD10, CD11c, CD20, CD22, CD23, CD38, CD79b, FMC7, CD103, CD25, kappa and lambda light chains) by flow cytometry was done on bone marrow samples. CD20, CD5, CD23, Bcl-2, Bcl-6, kappa and lambda light chain immunostaining were performed on fixed bone marrow trephine biopsy specimen. The sensitivity of IHC was 81.8% in chronic lymphocytic leukemia (CLL) and 100% in non Hodgkin lymphoma (NHL) as regards CD20, 100% in both groups as regards CD5, 46% in CLL and 66.7% in NHL as regards CD23, 33.3% in CLL and 50% in NHL as regards kappa chain, 20% in CLL and 33.3% in NHL as regards lambda chain. We found that IHC and flow cytometry are equally effective in diagnosing CLL; however, IHC might be slightly more sensitive than flow cytometry in detecting bone marrow infiltration in NHL and hairy cell leukemia (HCL)

Risk identification framework in construction of Egyptian mega housing projects

Egypt's population is increasing and expected to exceed 120 million by 2050. Egypt constructed mega housing projects (M.H.P) to cater with that escalation in population. The Egyptian strategy 2030 prioritized the construction of M.H.P. Contractors’ in Egypt have struggled to manage construction risks and deliver housing projects successfully. The aim of the paper is to develop a conceptual risk identification framework to improve contractors’ risk identification practices during the construction of mega housing projects in Egypt. The objectives of the paper are to analyse risk management practices in Egyptian M.H.P and to develop a risk identification framework (CRIF). The paper reviewed the literature of identified risks in construction of mega projects. Through a constructivism paradigm, the paper adopted the interview technique and allocated contractors’ recent risk practice. Qualitative risk information is analysed using NVivo tool for qualitative analysis. The paper used the ISO 31,000 as a backdrop to design a conceptual risk identification framework (CRIF), and a computerized risk identification database (CRID) using visual basic programming. The paper further produced generic guidelines to support the use of the CRIF during construction of M.H.P. Availability of resources, poor financial status, and weak technical training were the most common risks in construction of mega projects worldwide. The paper presented a risk breakdown structure (R.B.S) that included M.H.P common opportunities and challenges in Egypt. Egypt’s main challenges in construction of M.H.P included Management of Resources, Project Management, and Cash flow issues. The CRIF guides contractors’ in Egypt to improve risk knowledge, and management. The CRID improves the management of identified risks by providing a database for future M.H.P. The guidelines support contractors’ in using the conceptual risk identification framework. The paper updates risk identification process by adding multidisciplinary risk elements including risk communication, risk knowledge, and considering the context in building frameworks. The paper enhances contractors’ capability in management and identification of risks in construction of M.H.P. The paper allowed researchers to manage challenges and opportunities in construction of mega housing project in Egypt

Thermal Performance Evaluation for Two Designs of Flat-Plate Solar Air Heater : An Experimental and CFD Investigations

The main objective of this research was to create two different configurations of a flat-plate solar air heater, namely, Conventional-Case A and Modified-Case B, and develop a three-dimensional computational fluid dynamics (CFD) model using ANSYS R15.0. The purpose of the CFD model was to simulate the heat transfer behavior of the proposed solar air heaters under unsteady conditions. The RNG k-ε turbulence model was employed for this CFD study. The experiments were conducted on sunny days, under the same conditions as the Egyptian climate. The results of the experiments show that the simulated CFD model and the measured outlet airflow temperatures, relative humidity, and velocities of the two tested solar air heaters were compared. The developed model made very satisfactory predictions. Moreover, the deviations between the average CFD outlet air temperatures and the experimental results were 7% and 7.8% for Case B and Case A, respectively. The CFD-simulated average relative humidity was reduced by 31.6% when using Case B compared with Case A, and it was reduced by 28.8% when comparing the experimental data to Case B. Additionally, the average CFD thermal efficiencies obtained for Case B and Case A were 28.7% and 21.6%, respectively, while the average experimental thermal efficiencies for the cases were 26.4% and 18.2%, respectively. The proposed model can be used to design and simulate other solar air heater designs.Peer reviewe