Specialized Inter-Particle Interaction Lbm For Patterned Superhydrophobic Surfaces

SPECIALIZED INTER-PARTICLE INTERACTION LBM FOR PATTERNED SUPERHYDROPHOBIC SURFACES by AMAL S. YAGUB ABSTRACT: Superhydrophobic surface characteristics are important in many industrial applications, ranging from the textile to the military. It was observed that surfaces fabricated with nano/micro roughness can manipulate the droplet contact angle, thus providing an opportunity to control the droplet wetting characteristics. The Shan and Chen (SC) lattice Boltzmann model (LBM) is a good numerical tool, which holds strong potentials to qualify for simulating droplets wettability. This is due to its realistic nature of droplet contact angle (CA) prediction on flat smooth surfaces. But SC-LBM was not able to replicate the CA on rough surfaces because it lacks a real representation of the physics at work under these conditions. By using a correction factor to influence the interfacial tension within the asperities, the physical forces acting on the droplet at its contact lines were mimicked. This approach allowed the model to replicate some experimentally confirmed Wenzel and Cassie wetting cases. Regular roughness structures with different spacing were used to validate the study using the classical Wenzel and Cassie equations. This work highlights the strength and weakness of the SC model and attempts to qualitatively conform it to the fundamental physics, which causes a change in the droplet apparent contact angle, when placed on nano/micro structured surfaces. In the second part of this work, the model is used also to analyze the sliding of droplets in contact with flat horizontal surfaces. This part identifies the main factors, which influence the multiphase fluids transport in squared channels. Effects of dimensionless radius, Weber number, Reynolds number and static contact angles are evaluated by calculating the power required for moving single droplets in comparison to the power needed for moving the undisturbed flow in the channel. Guidelines for optimizing the design of such flow are presented. In last part of work, the sliding of droplets on sloped surfaces with and without roughness is numerically investigated. The Shan and Chen (SC) Lattice Boltzmann model (LBM) is used to analyze the effect of pinning on the movement of droplets placed on sloped surfaces. The model is checked for conformance with the Furmidge equation which applies to tilted unstructured surfaces. It is shown that a droplet sliding on a perfectly smooth surface requires very minimal slope angle and that pinning due to the inhomogeneous nature of manufactured smooth surfaces is the key factor in determining the minimal slope angle. The model is also used on sloped rough surfaces to check the effects of roughness on the movement of single droplets. The numerical outcomes are compared with published experimental results for validation and a dimensionless number is suggested for quantifying the degree of pinning needed to control the behavior of sliding droplets on sloped surfaces

On the Extension of Exponentiated Pareto Distribution

In this study, an extended exponentiated Pareto distribution is proposed. Some statistical properties are derived. We consider maximum likelihood, least squares, weighted least squares and Bayesian estimators. A simulation study is implemented for investigating the accuracy of different estimators. An application of the proposed distribution to a real data is presented

The diagnosis of COVID-19 in CT images using hybrid machine learning approaches (CNN & SVM)

The new coronavirus disease (2019) has spread quickly as an acute respiratory distress syndrome (ARDS) among millions of individuals worldwide. Furthermore, the number of COVID-19 checking obtainable in hospitals is very limited as compared to the rising number of infections every day. As an outcome, an automatic detection system must be implemented as a quick diagnostic tool for preventing or reducing the spread of COVID-19 among humans. The present paper aims to propose an automated system by means of a hybrid Deep Learning ("convolutional neural network"(CNN)) and "support vector machine (SVM)" approach for identifying COVID-19 pneumonia-infected patients on the basis of chest computed tomography (746 CT images of "COVID-19" and "non-COVID-19"). The proposed system is composed of three phases. The first, pre-processing phase begins with converting CT images into greyscale level CT images of equal size (256×256). The "contrast limited adaptive histogram equalization" technology is adopted to enhance the intensity levels, and demonstrate the feature of lung tissue. It is also necessary to normalize the division of the image elements by 255 to make the values between 0 and 1, as this will speed up the processing process. The second phase, the CNN (SimpNet model), was applied as a deep feature extraction technique to identify CT samples. The SVM classifier and SoftMax function are employed in the third phase to classify COVID-19 pneumonia-infected patients. Specificity, Sensitivity, "F-score", Accuracy, and "area under curve" are used as criteria to estimate the efficiency of the classification. The results showed a high accuracy rate of COVID-19 classification which reached (98%) and (99.1%) for CNN-SoftMax and CNN-SVM classifier, respectively in the tested dataset (225 CT images)

Aflatoxin B1 as an endocrine disruptor among miller flour workers

Aim: Aflatoxin В1 has been stated to inhibit the function of different endocrine glands. This study was proposed to clarify the possible effects of aflatoxin B1 as an endocrine disruptor on pituitary gland, thyroid gland and gonads among miller flour workers, and to evaluate its effects on human male sexual function. Methods: A case-control study was conducted in a flour mill in Helwan District Cairo, Egypt in 2019. The study included 42 exposed flour milling male workers from the grinding department which showed the highest level of aspergillus flavus in the air sampling of airborne fungi and 40 non-exposed males. Serumaflatoxin В1/albumin, luteinizing hormone, follicle stimulating hormone, testosterone, 17-beta-estradiol, free triiodothyronine, free thyroxin and thyroid stimulating hormone were measured for the studied groups. Results: Sampling of airborne fungi revealed that aspergillus flavus and penicillum were the predominant fungal types in the flour mill. Indoor/Outdoor ratios for aspergillus flavus were ≥ 1 in all the locations indicating presence of indoor sources. Serum Aflatoxin В1/albumin, luteinizing hormone and follicle stimulating, the existence of various types of sexual disorders (decreased libido, impotence and premature ejaculation) were higher while testosterone was lower in the miller flour workers compared to non-exposed. However, there was no significant difference regarding 17-beta-estradioland thyroid hormone levels between both studied groups. Conclusion: Aflatoxin B1creates possible human male reproductive health distresses in miller flour workers

Aflatoxin B1 as an endocrine disruptor among miller flour workers

Aim: Aflatoxin В1 has been stated to inhibit the function of different endocrine glands. This study was proposed to clarify the possible effects of aflatoxin B1 as an endocrine disruptor on pituitary gland, thyroid gland and gonads among miller flour workers, and to evaluate its effects on human male sexual function. Methods: A case-control study was conducted in a flour mill in Helwan District Cairo, Egypt in 2019. The study included 42 exposed flour milling male workers from the grinding department which showed the highest level of aspergillus flavus in the air sampling of airborne fungi and 40 non-exposed males. Serumaflatoxin В1/albumin, luteinizing hormone, follicle stimulating hormone, testosterone, 17-beta-estradiol, free triiodothyronine, free thyroxin and thyroid stimulating hormone were measured for the studied groups. Results: Sampling of airborne fungi revealed that aspergillus flavus and penicillum were the predominant fungal types in the flour mill. Indoor/Outdoor ratios for aspergillus flavus were ≥ 1 in all the locations indicating presence of indoor sources. Serum Aflatoxin В1/albumin, luteinizing hormone and follicle stimulating, the existence of various types of sexual disorders (decreased libido, impotence and premature ejaculation) were higher while testosterone was lower in the miller flour workers compared to non-exposed. However, there was no significant difference regarding 17-beta-estradioland thyroid hormone levels between both studied groups. Conclusion: Aflatoxin B1creates possible human male reproductive health distresses in miller flour workers.   Acknowledgement: The authors are grateful to the National Research Centre for funding this research.   Funding: This study was funded by the National Research Centre, Egypt.   Conflicts of interest: None declared.   &nbsp

Screw nail medialization of arytenoid in unilateral adductor vocal cord paralysis: A new office procedure

AbstractObjectivesThe aim of this study is to describe and evaluate new technique for treatment of unilateral vocal cord paralysis giving the same results of the standard procedure but minimizing the surgical trauma.Patients and methodsA prospective study was carried out between November 2009 and November 2011 in the Otorhinolaryngology Department, Zagazig University Hospitals, Egypt. It included 12 patients with unilateral idiopathic vocal cord paralysis who were managed by this new technique. Preoperative and postoperative video-laryngoscopy was done, maximal phonation time was calculated and ratings grade of dysphonia was compared.ResultsPostoperative video-laryngoscopy relieved complete glottic gap closure in 83.3% of cases and partial glottic gap in the remaining 16.7% of cases. The mean preoperative maximal phonation time was 9.42s and the postoperative value was 21.5s with a mean difference of 11.6s. The rating of the grade of dysphonia showed great improvement in the patient’s voice quality from severe dysphonia preoperatively to normal or near-normal voice postoperatively. All patients were satisfied with the results of the procedure except one patient (8.3%).ConclusionThe screw nail medialization technique gives a good reliable and easy procedure under local anesthesia for managing unilateral vocal cord paralysis and avoids the disadvantages of infection laryngoplasty and medialization thyroplasty using implants

Relational social recommendation: Application to the academic domain

This paper outlines RSR, a relational social recommendation approach applied to a social graph comprised of relational entity profiles. RSR uses information extraction and learning methods to obtain relational facts about persons of interest from the Web, and generates an associative entity-relation social network from their extracted personal profiles. As a case study, we consider the task of peer recommendation at scientific conferences. Given a social graph of scholars, RSR employs graph similarity measures to rank conference participants by their relatedness to a user. Unlike other recommender systems that perform social rankings, RSR provides the user with detailed supporting explanations in the form of relational connecting paths. In a set of user studies, we collected feedbacks from participants onsite of scientific conferences, pertaining to RSR quality of recommendations and explanations. The feedbacks indicate that users appreciate and benefit from RSR explainability features. The feedbacks further indicate on recommendation serendipity using RSR, having it recommend persons of interest who are not apriori known to the user, oftentimes exposing surprising inter-personal associations. Finally, we outline and assess potential gains in recommendation relevance and serendipity using path-based relational learning within RSR

A Proposed Conceptualization of a Training Program for Secondary School Social Studies Teachers in Light of the Degree of Use and Challenges to Employ Some Applications of Artificial Intelligence in Education تصور مقترح لبرنامج تدريبي لمعلمات الدراسات الاجتماعية بالمرحلة الثانوية في ضوء درجة الاستخدام والتحديات لتوظيف بعض تطبيقات الذكاء الاصطناعي في التعليم

Abstract: The study aimed at identifying the use degree of secondary school social studies teachers for some applications of Artificial Intelligence in three axes (planning, implementation and evaluation) of the lesson, and the challenges faced by the teachers of social studies when employing the applications of artificial intelligence in education. The sample of the study included (130) high school social studies teachers. The study was applied in the second semester of the academic year 1441 AH. The study restricted to a random sample of high school social studies teachers in the city of Riyadh in Saudi Arabia. The study tool included a questionnaire divided into four axes to answer the questions of the research. The study depended on the descriptive methodology. The study found that the use degree of high school social studies teachers for some applications of Artificial Intelligence was low; and that there are a set of challenges that obstruct their use of the applications. In light of that, a proposed conceptualization for a training program for the teachers of social studies was developed to train them on the applications of Artificial Intelligence. ملخص: استهدفت الدراسة التعرُّف إلى درجة استخدام معلمات الدراسات الاجتماعية بالمرحلة الثانوية لبعض تطبيقات الذكاء الاصطناعي في ثلاثة محاور: (تخطيط، وتنفيذ، وتقييم) الدرس، والتحديات التي تواجهها معلمات الدراسات الاجتماعية عند توظيف تطبيقات الذكاء الاصطناعي في التعليم، وتكوّنت عينة الدراسة من (130) معلمة من معلمات الدراسات الاجتماعية بالمرحلة الثانوية. طُبِّقت الدراسة في الفصل الدراسي الثاني للعام الدراسي 1441هـ، واقتصرت على عينة عشوائية من معلمات الدراسات الاجتماعية بالمرحلة الثانوية في مدينة الرياض بالمملكة العربية السعودية. وتكوّنت أداة الدراسة من استبانة قُسِّمت إلى أربعة محاور للإجابة عن تساؤلات البحث، واعتمدت الدراسة على المنهج الوصفي، وتوصلت إلى أن درجة استخدام معلمات الدراسات الاجتماعية بالمرحلة الثانوية لتطبيقات الذكاء الاصطناعي كانت منخفضة، وهناك مجموعة من التحديات التي تعوق استخدامهن لها، وفي ضوء ذلك تم وضع تصور مقترح لبرنامج تدريبي لمعلمات الدراسات الاجتماعية لتدريبهن على تطبيقات الذكاء الاصطناعي

Effect of pre-eclampsia on glomerular filtration rate in Sudanese women

Background: Creatinine clearance is safest method to measure glomerular filtration rate (GFR) in pregnancy. The objectives was to study a case-control study conducted in Omdurman Maternity Hospital aimed to assess GFR, using creatinine clearance and magnitude of changes of serum creatinine in pre-eclampsia.Methods: Pre-eclamptic were 70, normal pregnant 96 and non-pregnant 63. Investigations were done at St Hellier's hospital London. Serum and urine creatinine were measured using Jaffé reaction and spectrophotometer. 24-hour urine output was measured and creatinine clearance calculated to find GFR. GFR was calculated in ml/min/mm2 using John Hopkins’ method.Results: The mean serum creatinine in pre-eclamptic (68.6µmol/L) was less than non-pregnant (75.5µmol/L) (P=0.001) but was higher than normal pregnant (62.4µmol/L) (P=0.003). Mean GFR pre-eclamptic (68.6ml/min.1.73m2) was less than non-pregnant (87.0ml/min/1.73m2) (P=0.0001) and normal pregnant (89.0ml/min/1.73ml/min/1.73m2) (P =0.0001).Conclusions: GFR decreased at term in normal pregnancy and even more in pre-eclampsia. Serum creatinine levels increased and did not correlate with GFR changes in pre-eclampsia

Spectrophotometric Assay of Noradrenaline in Pharmaceutical Formulation with Quinalizarin in Aqueous Solution

A simple, rapid and sensitive spectrophotometric method for the determination of noradrenaline was developed. The method is based on the proton transfer reaction with quinalizarin in aqueous neutral solution to form a violet product showing maximum absorbance at 560 nm with molar absorptivity of 6680 l.mol-1.cm-1. The method follows Beer’s law over the concentration range (5.91×10-6 -5.91×10-5) mol.L-1 The accuracy (average recovery) of the method is 99.72% and the precision (RSD) of the method is less than 1.5%.The method was successfully applied for the determination of noradrenaline in pharmaceutical formulation as injection and the results were in a good agreement with the standard addition procedure