Dissipative Processes in the Early Universe: Bulk Viscosity

In this talk, we discuss one of the dissipative processes which likely take place in the Early Universe. We assume that the matter filling the isotropic and homogeneous background is to be described by a relativistic viscous fluid characterized by an ultra-relativistic equation of state and finite bulk viscosity deduced from recent lattice QCD calculations and heavy-ion collisions experiments. We concentrate our treatment to bulk viscosity as one of the essential dissipative processes in the rapidly expanding Early Universe and deduce the dependence of the scale factor and Hubble parameter on the comoving time $t$. We find that both scale factor and Hubble parameter are finite at $t=0$, revering to absence of singularity. We also find that their evolution apparently differs from the one resulting in when assuming that the background matter is an ideal and non-viscous fluid.Comment: 8 pages, 2 eps figure, Invited talk given at the 7th international conference on "Modern Problems of Nuclear Physics", 22-25 September 2009, Tashkent-Uzbekista

Risk Assessments are the Diagnosis not the Cure: How Using Algorithms as Diagnostic Tools Can Prevent the Bait-And-Switch of Unconstitutional Pretrial Practices

This Comment takes a closer look at the very timely debate revolving around the cash bail system. This Comment surveys the history of bail, addresses the problems caused by cash bail, evaluates the two main schools of thought on bail reform, and proposes a comprehensive solution to the identified problems

Analytical and stability studies on medical cosmetics

Two simple and sensitive spectrofluorimetric (method Ι) and spectrophotometric (method ΙΙ) methods have been developed for the determination of some chloride containing toothpastes and panthenol-containing cosmetic preparations respectively. Method Ι is based on quantitative fluorescence quenching of (terbium-salicylate-hexamine ternary complex) by fluoride which could be measured at λem/λex of 547nm/322nm. The ∆Fconcentration plot was rectilinear over the concentration range of 0.5-20 µg/ml. Method ΙΙ depends reaction of panthenol with nitrobenzoxadiazole chloride (NBD-Cl) and measuring the absorbance of the resultant product at 480nm. The absorbance- concentration plot was rectilinear over the concentration range of 2-20 µg/m

Using some Natural Minerals to Remove Cadmium from Polluted Water

تعد مشكلة ندرة المياه من اهم المشاكل التىتواجه الانسان فى مختلف المجالات المعيشية والاقتصادية مثل مجال الصناعة والزراعة و السياحة مما يدفع الانسان لاستخدام المياه منخفضة الجوده كمياه الصرف الصناعى. ويعتبر استخدام بعض المركبات الكيميائية فى التخلص من العناصر الثقيلة مثل الكادميوم هو نهج ضار بالبيئة. و من المعروف جيدًا أن عنصر الكادميوم يسبب مشاكل كبيرة عند وجوده في الماء ومن ثم يغزو التربة والنباتات والسلسلة الغذائية للإنسان. وبالتالى فان استخدام المواد الطبيعية بدلاً من المواد الكيميائية لإزالة الكادميوم من المياه الملوثة نهجصديقًا للبيئة. لذلك تم التركيز في هذا البحث على استخدام بعض المعادن الطبيعية مثلالمونتموريلونيتوالبنتونيتوالزيوليتلامتصاص عنصر الكادميوم من المياه الملوثة. و قد استخدمت تركيزات مختلفة من الكادميوم في المحاليل 10 و 30 و 50 جزء في المليون و تم معالجتها بثلاث نسب مختلفة لكل معدن (1 و 3 و 5٪ وزن الى حجم). وقد أثبتت النتائج التي تم الحصول عليها أن زيادة نسبة الاضافات إلى 5٪ تزيد من امتزاز الكادميوم من المحلول خاصة عند تركيز 50 جزء في المليون من الكادميوم. حصل الزيوليت على أعلى نسبة امتزاز (47.90 جزء في المليون) ، يليه مونتموريلونيت (44.99 جزء في المليون) وأقل نسبة كانت للبينتونيت (38.97 جزء في المليون). لذلك ، يمكن التوصية بأن إضافة الزيوليت هي المادة الأكثر ملاءمة لإزالة عنصر Cd من المياه الملوثة.Water scarcity is one of the most important problems facing humanity in various fields such as economics, industry, agriculture, and tourism. This may push people to use low-quality water like industrial-wastewater. The application of some chemical compounds to get rid of heavy metals such as cadmium is an environmentally harmful approach. It is well-known that heavy metals as cadmium may induce harmful problems when present in water and invade to soil, plants and food chain of a human being. In this case, man will be forced to use the low quality water in irrigation. Application of natural materials instead of chemicals to remove cadmium from polluted water is an environmental friendly approach. Attention was drawn in this research work to use some natural minerals as zeolite, bentonite and montmorillonite to adsorb cadmium element from polluted water. Various concentrations of cadmium in solutions 10, 30 and 50 ppm were treated with three different ratios of each mineral; 1, 3 and 5% (W/V). The obtained results proved that increasing the ratio of amendments to 5% increased Cd adsorption from solution particularly at 50ppm Cd. Zeolite obtained the highest ratio of adsorption (47.90 ppm), followed by montmorillonite (44.99 ppm) and the lowest was bentonite (38.97 ppm). Therefore, it can be recommended that addition of zeolite is the most favorable material to remove Cd element from polluted water

A Hybrid Continual Machine Learning Model for Efficient Hierarchical Classification of Domain-Specific Text in The Presence of Class Overlap (Case Study: IT Support Tickets)

In today’s world, support ticketing systems are employed by a wide range of businesses. The ticketing system facilitates the interaction between customers and the support teams when the customer faces an issue with a product or a service. For large-scale IT companies with a large number of clients and a great volume of communications, the task of automating the classification of incoming tickets is key to guaranteeing long-term clients and ensuring business growth. Although the problem of text classification has been widely studied in the literature, the majority of the proposed approaches revolve around state-of-the-art deep learning models. This thesis addresses the following research questions: What are the reasons behind employing black box models (i.e., deep learning models) for text classification tasks? What is the level of polysemy (i.e., the coexistence of many possible meanings for a word or phrase) in a technical (i.e., specialized) text? How do static word embeddings like Word2vec fare against traditional TFIDF vectorization? How do dynamic word embeddings (e.g., PLMs) compare against a linear classifier such as Support Vector Machine (SVM) for classifying a domain-specific text? This integrated article thesis aims to investigate the aforementioned issues through five empirical studies that were conducted over the past four years. The observation of our studies is an emerging theory that demonstrates why traditional ML models offer a more efficient solution to domain-specific text classification compared to state-of-the-art DL language models (i.e., PLMs). Based on extensive experiments on a real-world dataset, we propose a novel Hybrid Online Offline Model (HOOM) that can efficiently classify IT Support Tickets in a real-time (i.e., dynamic) environment. Our classification model is anticipated to build trust and confidence when deployed into production as the model is interpretable, efficient, and can detect concept drifts in the data

Rotating Scheimpflug Imaging Indices in Different Grades of Keratoconus

Purpose. To evaluate accuracy of various Keratoconus (KC) screening indices, in relation to Topographic Keratoconus (TKC) grading. Setting. Al Watany Eye Hospital, Cairo, Egypt. Methods. Data of 103 normal (group 1) and 73 KC eyes (group 2), imaged by Pentacam (branded as Allegro Oculyzer), were analysed. Group 2 was divided into 2a: 14 eyes (TKC = 1, early KC), 2b: 25 eyes (TKC = 1 to 2 or 2, moderate KC), and 2c: 34 eyes (TKC = 2 to 3 up to 4, severe KC). Participants were followed up for six years to confirm diagnosis. Area under the receiver operating characteristic curve (AUROC) was calculated for evaluated curvature, elevation, and pachymetry indices with various reference shapes at different diameters. Results. When comparing normal to KC eyes, ten indices had significantly higher AUROC. Only five of them had significantly higher AUROC in early KC compared to normal corneas: Pachymetry Progression Index- (PPI-) Maximum (Max), Ambrósio’s Relational Thickness- (ART-) Max, PPI-Max minus PPI-Minimum (Min), central corneal thickness (CCT), and diagonal decentration of thinnest point from the apex (AUROC = 0.690, 0.690, 0.687, 0.683, and 0.674, resp.). Conclusion. Generally, ten pachymetry and elevation-based indices had significantly higher AUROC. Five indices had statistically significant high AUROC when comparing early KC to normal corneas

Effectiveness of Green Roofs and Green Walls on Energy Consumption and Indoor Comfort in Arid Climates

Increased urbanization have many negative effects on human well-being, city infrastructure, electricity usage and the increase of indoor temperatures. A solution may be to retrofit existing buildings, with implementing a vegetated layer to roofs and walls, this may enhance building performance, reduce consumption and improve indoor comfort. Cities with tall buildings may be more adequate to implement a green-wall as it have more area to make impact. This paper examines the energy reduction advantages of adding greenery on buildings in the hot arid climate of Egypt by considering three typical types of residential buildings in the city of Cairo as a case study. Designbuilder software was selected to stimulate the buildings chosen in this research. The results shows that an extensive soil thickness of 15cm performs better in the arid climates. electricity consumption for the base case is 52 kWh/m2 annually when used a traditional external envelop and dropped to 43 kWh/m2 when a vegetated layer added to the whole building (roof & wall), annual electricity consumption reduced by 17% to 25% per annum when added a vegetated layer. In addition to enhancing the indoor thermal comfort by 3 PMV values and indoor air temperature by 5°C