Clay minerals damage quantification in sandstone rocks using core flooding and NMR

Sandstone oil reservoirs consist of different clay minerals such as kaolinite, illite, and chlorite. These clay minerals highly affect the formation damage during enhanced oil recovery (EOR) and well stimulation operations in these reservoirs. No attention was paid to investigate the effect of these clay minerals on the formation damage during different reservoir processes. In addition, no solution was introduced to mitigate the effect of clay minerals on the formation damage in sandstone reservoirs. In this study, the effect of clay mineral contents and type on the formation damage was studied in detail by injecting water and HCl as damaging fluids. Bandera grey, Berea, and Bandera brown sandstone rocks with various clay mineral contents were studied. XRD was used to characterize the sandstone rocks to determine the clay type and content in each rock. Two core plugs from each rock were selected for HCl and water injection. Core flooding experiments were performed to measure the initial and final permeability. In the core flooding experiments, fluids were injected into the cores at 25 °C and at a backpressure of 1000 psi. SEM was carried out before and after flooding for the tested rocks to locate the change in the clay distribution inside the rocks. The NMR analysis of core samples was done before and after flooding with the damaging fluid to quantify the formation damage and to find the possible damaging mechanism. NMR was used to locate the damage inside the rock due to the migration of clay minerals. Based on the core flooding, SEM, and NMR analysis, the maximum damage by the fresh water took place in Berea sandstone core due to fine migration and clay swelling. The illite clay mineral and chlorite can cause the formation damage on HCl injection. Illite can break down and migrates in the cores during the acid injection. In sandstone acidizing, chlorite clay mineral caused iron hydroxide precipitation inside the cores during treatment with mud acid. NMR showed that clay minerals plugged the pore throats of the rocks and reduced the rock permeability during the injection of fresh water

Viral Hepatitis A to E in South Mediterranean Countries

Viral hepatitis represents an important health problem in the South Mediterranean countries, Egypt, Libya, Tunisia, Algeria and Morocco. Emerging natural history and epidemiological information reveal differences in the overall epidemiology, risk factors and modes of transmission of viral hepatitis A, B, C, D, E infections in the South Mediterranean region. The differences in the in incidence and prevalence of viral hepatitis across North African countries is attributed to variations in health care and sanitation standards, risk factors and immunization strategies. The active continuous population movement through travel, tourism and migration from and to the South Mediterranean countries contribute to the spread of infections due to hepatitis viruses across borders leading to outbreaks and emergence of new patterns of infection or introduction of uncommon genotypes in other countries, particularly in Europe

Bond Strength of Concrete Containing Different Recycled Coarse Aggregates

Some of the remnants of construction demolition wastes could be used after recycling as coarse aggregate in concrete industry. Among these wastes are ceramics, shale bricks and hardened concrete. This research was carried out to determine the effect of using such recycled aggregate (RA) as total or partial replacement of the natural dolomite coarse aggregate in concrete mixes on their compressive and bond strength with steel bars. Two types of concrete were investigated in this research which included normal concrete and self-compacted concrete. The main variables taken into consideration wee, the type of concrete, the type and percentage of the recycled aggregate and the age of testing. The consistency of the normal fresh concrete was measured by the slump test. However, the workability and flowability of the self-compacted fresh concrete were measured using slump test, V-funnel test. Out of the experimental test results, equations were predicted which correlated between the concrete compressive strength and bond strength of both the recycled aggregate ordinary concrete and the recycled aggregate self-compacted concrete. These equations were completely different than that of the steel-concrete bond equation of concrete with natural aggregate. Out of this research results, the recycled aggregate concrete could be used in both non structural applications and in some structural applications with special precautions

Reliability and Cost-Benefit Efficient in a Two-Dissimilar- Unit with Warm Unit Standby Case Subject to Arbitrary Repair and Replacement

In this paper, we deal with a warm case of standby system made up of two-dissimilar-units. One of these units is a high quality unit, while the other is a low quality one and may require repairs or replacement with a different lesser device in the event of failure, so the first unit is given priority in use. Assume that an arbitrary distribution for repairing the main unit and standby unit. We also examine all transition probabilities and calculate mean sojourn time, availability, and repair time. In the end, we use all of the previous measurments to evaluate the cost-benefit of the system

Qualitative and Quantitative Analysis of Amygdalin in Sweet and Bitter Almond Kernel in Erbil City Using GC-FID Technique

This paper described the determination of amygdalin in sweet and bitter almond kernel in Erbil City using GC-FID technique. The effect of wavelength, selecting the best solvent as a mobile phase, flow rate, injection volume, pH, and temperature had been studied, in which the flow rate 10.0 ml min-1 at the concentration range (20-600) μg ml-1 with correlation coefficient and relative error (0.9990, 1.501%)respectively

The Response, Operability, and Type of Surgery Following Neoadjuvant Chemotherapy in Sudanese Patients with Locally Advanced Breast Cancer

Background:Neoadjuvant chemotherapy (NACT) treatment has become the standard treatment for locally advanced breast cancer (LABC) in many centers worldwide. Objectives: This study evaluates the short-term response of patients with LABC to NACT and its impact on operability and the type of surgery. Patients and Methods: This is a descriptive analytical hospital-based study including 147 patients with LABC who were presented to Plastic and Reconstructive Surgery Unit at Soba University hospital (SUH), between January 2012 and December 2014, and were treated with NACT. Clinical and pathological responses to neoadjuvant chemotherapy were evaluated according to Union for International Cancer Control criteria, operability, and the type of surgery performed was also recorded. Results: All patients were females, the mean age was 43 ± 7 years, of them 53.7% were pre-menopausal, 51% presented with a breast lump, 19.7% with nipple discharge, and 19% with skin changes and ulceration. The mean initial tumor size was 7 cm ± SD. Following NACT, complete clinical response was reported in 30 patients (20.4%), partial clinical response in 92(62.6%), stable clinical response in 20 (13.6%), and five (3.4%) had progressive clinical response. Initial smaller tumors (size < 5 cm) showed a better clinical response to NACT as 76.7% of complete clinical response was achieved.Pathological complete response was achieved in 25(17%) patients, pathological partial response in 102(74.1%), and pathological stable disease in 13(8.8%). Following NACT, breast conserving surgery was performed in 78(53.1%) patients, Modified Radical Mastectomy in 64(43.5%), 25 of them had Latissimus Dorsi, and five patients were not offered surgery as they developed progressive disease during the study period. Conclusion: Following NACT, it was possible to perform surgery in more than 96% of patients with LABC

New Mixed Ligand Complexes of Ditertiary Phosphanes with Ni(II) Alkylxanthates

Mixed Iigand complexes of Ni(II) with alkylxanthates and ditertiary phosphanes of the composition Ni(ROCSSb(diphoshhave been prepared, where R = methyl, ethyl, propyl, butyl, and cyclohexyl and diphos = bis(diphenylphosphino)ethane (dpe) and bis- (diphenylphosphino)butane (dpb). The newly prepared compounds were characterized on the basis of chemical analyses, infrared and electronic spectra, lH-NMR, molar conductance, and thermal analysis. A square planar structure was proposed for the complexes

A Parabolic Transform and Averaging Methods for General Partial Differential Equations

Averaging method of the fractional general partial differential equations and a special case of these equations are studied, without any restrictions on the characteristic forms of the partial differential operators. We use the parabolic transform, existence and stability results can be obtained

Evaluation of Cerebral Hemodynamics in Cirrhotic Patients by Transcranial Doppler Ultrasonography and its Relation to Hepatic Encephalopathy

The study aimed at Aim evaluation the cerebral hemodynamics in cirrhotic patients by transcranial Doppler ultrasonography and its relation to hepatic encephalopathy. This study is a prospective study , 50 subjects attended El Hussein university hospital, inpatient and outpatient clinic are classified into three groups, group I(10 subjects as a healthy control),group II (20 subjects with liver cirrhosis without hepatic encephalopathy) and group III(20 subjects with liver cirrhosis with hepatic encephalopathy). All patients included in the study underwent a full history taking,complete physical examination, liver functions tests,blood ammonia level,C.B.C,blood urea and serum creatinine and pelvi-abdominal ultarasonography. Transcranial Doppler done for all patients participated in the study using a 2 MHz transducer. The results showed that as regard Trans cranial Doppler ultrasound parameters, we found a statistical significant difference between the three groups as regard Pulsatility Index (P ˂ 0.001), Breath-Holding Index (P ˂ 0.001) ) , Maximum Flow Velocity(P ˂ 0.001) and Mean (P ˂ 0.001), whereas Pulsatility Index, , Maximum Flow Velocity and Mean are higher in patient with Hepatic Encephalopathy, but Breath-holding index is low, there is no statistical significant difference (P > 0.05) between them as regard Minimum Flow Velocity. Conclusion: Transcranial doppler ultrasonography is easy, rapidly done not invasive method for evaluation of cerebral hemodynamic in cirrhotic patient and predection of hepatic encephalopathy. Keywords: Transcranial doppler, Hepatic encephalopathy, Cirrhosis

Study of obesity associated proopiomelanocortin gene polymorphism: Relation to metabolic profile and eating habits in a sample of obese Egyptian children and adolescents

AbstractBackgroundMelanocortinergic system represents a known system involved in the central regulation of body weight with the central proopiomelanocortin (POMC) neurons forming a potent anorexigenic network. Polymorphisms in the POMC gene locus are associated with obesity phenotypes.AimTo assess the contribution of the POMC gene 9-bp insertional polymorphism in the susceptibility to obesity and its relation to body mass index (BMI) and adiposity-related co-morbidities in obese children and adolescents; as well as binge eating behavior.Patients and methodsFifty obese children and adolescents with simple obesity were screened for Binge Eating Disorder (BED) by The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), they were compared to 50 age, sex and pubertal stage-matched non obese controls. Anthropometric measurements, blood pressure, abdominal ultrasound for fatty liver, measurement of fasting lipid profile, fasting insulin, fasting blood glucose and assessment of POMC gene 9-bp insertional polymorphism were done.ResultsObese patients had significantly higher anthropometric measurements, blood pressure percentiles, fasting glucose, fasting insulin, homeostasis model assessment for insulin resistance (HOMA-IR) and fasting lipid profiles, and higher frequency of occurrence of non alcoholic fatty liver disease and BED. Allelic frequencies of POMC gene 9bp insertional polymorphism were comparable in patients and controls (p=0.956). Fasting insulin levels were significantly higher in the heterozygous cases having the polymorphism than in wild homozygous cases; whereas no difference was observed among the controls.ConclusionThis polymorphism was associated with higher fasting insulin levels in the obese patients only. These findings support the hypothesis that the melanocortin pathway may modulate glucose metabolism in obese subjects indicating a possible gene-environment interaction. POMC variant may be involved in the natural history of polygenic obesity, contributing to the link between type 2 diabetes and obesity