1,434 research outputs found

    Hair histology as a tool for forensic identification of some domestic animal species

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    Animal hair examination at a criminal scene may provide valuable information in forensic investigations. However, local reference databases for animal hair identification are rare. In the present study, we provide differential histological analysis of hair of some domestic animals in Upper Egypt. For this purpose, guard hair of large ruminants (buffalo, camel and cow), small ruminants (sheep and goat), equine (horse and donkey) and canine (dog and cat) were collected and comparative analysis was performed by light microscopy. Based on the hair cuticle scale pattern, type and diameter of the medulla, and the pigmentation, characteristic differential features of each animal species were identified. The cuticle scale pattern was imbricate in all tested animals except in donkey, in which coronal scales were identified. The cuticle scale margin type, shape and the distance in between were characteristic for each animal species. The hair medulla was continuous in most of the tested animal species with the exception of sheep, in which fragmental medulla was detected. The diameter of the hair medulla and the margins differ according to the animal species. Hair shaft pigmentation were not detected in all tested animals with the exception of camel and buffalo, in which granules and streak-like pigmentation were detected. In conclusion, the present study provides a first-step towards preparation of a complete local reference database for animal hair identification that can be used in forensic investigations.Comment: 8 pages, 3 Figure

    Honeyword Generation Using a Proposed Discrete Salp Swarm Algorithm

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    إن كلمات العسل (Honeywords) هي كلمات مرور مزيفة مرافقة لكلمة المرور الحقيقية والتي تدعى كلمة السكر. يعد نظام كلمات مرور العسل نظامًا فعالاً لاكتشاف اختراق كلمات المرور مصمم لاكتشاف اختراق كلمة المرور بسهولة من أجل تحسين أمان كلمات المرور المشفرة. لكل مستخدم ، سيكون لملف كلمة المرور الخاص بنظام الكلمات العسلية كلمة مرور واحدة حقيقية مشفرة مصحوبة بالعديد من كلمات المرور المزيفة المشفرة. إذا قام شخص دخيل بسرقة ملف كلمات المرور من النظام ونجح في اختراق كلمات المرور محاولا تسجيل الدخول إلى حسابات المستخدمين ، فسيكتشف نظام كلمات المرور هذه المحاولة من خلال مدقق العسل. (Honeychecker) مدقق العسل هو خادمًا إضافيًا يميز كلمة المرور الحقيقية عن كلمات المرور المزيفة ويطلق إنذارًا إذا قام شخص دخيل بتسجيل الدخول باستخدام كلمة مرور العسل. تم اقتراح العديد من طرق توليد كلمات العسل خلال البحوث السابقة، مع وجود قيود على عمليات إنشاء كلمات العسل الخاصة بهم ، ونجاح محدود في توفير جميع ميزات كلمات العسل المطلوبة ، والتعرض للعديد من مشكلات كلمات العسل. سيقدم هذا العمل طريقة جديدة لتوليد كلمات العسل تستخدم خوارزمية سرب عنب البحر المتقطعة. خوارزمية سرب عنب البحر هي خوارزمية تحسين مستوحاة من الأحياء تحاكي سلوك سرب عنب البحر في بيئتها الطبيعية. تم استخدام  خوارزمية سرب عنب البحر لحل مجموعة متنوعة من مشاكل التحسين. ستعمل طريقة توليد الكلمات العسلية المقترحة على تحسين عملية توليد كلمات العسل وتحسين ميزات كلمات العسل والتغلب على عيوب التقنيات السابقة. ستوضح هذه الدراسة العديد من الاستراتيجيات السابقة لتوليد الكلمات العسلية، ووصف الطريقة المقترحة، وفحص النتائج التجريبية، ومقارنة طريقة إنتاج كلمات العسل الجديدة بالطرق السابقة.Honeywords are fake passwords that serve as an accompaniment to the real password, which is called a “sugarword.” The honeyword system is an effective password cracking detection system designed to easily detect password cracking in order to improve the security of hashed passwords. For every user, the password file of the honeyword system will have one real hashed password accompanied by numerous fake hashed passwords. If an intruder steals the password file from the system and successfully cracks the passwords while attempting to log in to users’ accounts, the honeyword system will detect this attempt through the honeychecker. A honeychecker is an auxiliary server that distinguishes the real password from the fake passwords and triggers an alarm if intruder signs in using a honeyword. Many honeyword generation approaches have been proposed by previous research, all with limitations to their honeyword generation processes, limited success in providing all required honeyword features, and susceptibility to many honeyword issues. This work will present a novel honeyword generation method that uses a proposed discrete salp swarm algorithm. The salp swarm algorithm (SSA) is a bio-inspired metaheuristic optimization algorithm that imitates the swarming behavior of salps in their natural environment. SSA has been used to solve a variety of optimization problems. The presented honeyword generation method will improve the generation process, improve honeyword features, and overcome the issues of previous techniques. This study will demonstrate numerous previous honeyword generating strategies, describe the proposed methodology, examine the experimental results, and compare the new honeyword production method to those proposed in previous research

    Histological Sequences of Long Bone Development in the New Zealand White Rabbits

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    Long bone development occurred through endochondral ossification. The current study investigated the main histological changes associated with the development of humerus from the New Zealand white rabbits. The upper limb or humerus during embryonic (12, 14, 15, 16, 18, 21, 24 and 27 days) and neonatal (3 and 7 days) development was processed for light microscopy. Three stages preceded endochondral ossification; limb bud (mesenchymal cells), cartilage primordia (mesenchymal condensation and differentiation into chondrocytes) and cartilage template (organization of chondrocytes into proliferative and hypertrophic zones) by 12, 14 and 15 days, respectively. At day 16, cartilage template elongated forming a cartilaginous diaphysis of the prospective humerus. At day 18, cartilaginous epiphyses were formed. Medullary cavity was established by day 21 with no signs of calcification in the bone collar. Primary ossification center appeared within the diaphysis at day 24 of embryonic development. Secondary ossification centers were seen within the epiphyses by day 3 of neonatal development. Two types of cartilage canals were investigated; short epiphyseal canals appeared from day 21 and long transphyseal canals appeared from day 27. At day 7 of neonatal development, the cartilage of the humerus was limited in two places; articular epiphyseal growth cartilage between articular surface and secondary ossification center, epiphyseal physeal growth cartilage between the secondary and primary ossification centers. The current study summarized the main histological stages of development of rabbit humerus. These results should be considered in molecular studies of endochondral bone formation

    Application of UPFC on stabilizing torsional oscillations and improving transient stability

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    This paper investigates the application of Unified Power Flow Controller (UPFC) to stabilize multi-mode torsional oscillations of sub-synchronous resonance (SSR), and to improve the transient stability during a three phase short circuit fault that may result in oscillatory torques on the generator rotor shaft causing serious damages to the system and may call for the disconnection of a wind farm to avoid any possible damages. Simulation is carried out using MATLAB/Simulink software. Results show that the proposed UPFC controller is very effective in damping all SSR modes of the system under study and in minimizing the potential for the wind farm disconnection during the studied faults. The proposed controller is simple and easy to be implemented

    Morphological and Biochemical Adaptive Changes Associated With A Short-period Starvation of Adult Male Japanese Quail (Coturnix japonica)

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    Objective: The morphological and biochemical impact of a short-period of starvation on Japanese quail was investigated. Materials and Methods: Ten adult male Japanese quail were divided into two groups; control fed and starved. The control-fed group was offered food and water ad libitum and the starved group was subjected to a short-period of food deprivation. After 2.5 days, the serum was obtained and different parameters including the total protein, AST, ALT, triglyceride, HDL, LDL, creatinine and urea were assessed. Gastrointestinal tract, stomach and liver were excised and their masses were estimated. Paraffin and resin embedded sections from the proventriculus, gizzard, liver, duodenum, kidney and pancreas were examined with a light microscopy. Results: Significant decreases in the masses of body, gastrointestinal tract, stomach and liver of the starved group were recorded. The liver and duodenum were the most affected organs. The liver showed depletion of glycogen, vacuolation, hyperemia and cellular infiltrations. Duodenal villi showed degenerative changes in lamina epithelialis and cellular infiltrations in the lamina propria. Biochemical analysis revealed a decreased level of total protein, AST and ALT, increased cholesterol, triglycerides and LDL and unchanged HDL, urea and creatinine by starvation. Conclusion: The current study described in details the effect of short time starvation on quail organs. Time-point adaptive responses of male quail to starvation and refeeding will be investigated in future studies

    Numerical and experimental investigations on efficient design and performance of hydrokinetic Banki cross flow turbine for rural areas

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    Micro hydrokinetic energy scheme presents an attractive, environmentally-friendly and efficient electric generation in rural, remote and hilly areas. However, this scheme is yet to be fully discovered, as researchers are still searching for solutions for the main problems of low velocity of current in the open flow channels and low efficiency of hydrokinetic turbines. This research proposes a novel system configuration to capture as much kinetic energy as possible from stream water current. This system, known as bidirectional diffuser augmented (BDA) channel, functions by utilizing dual directed nozzles in the flow and is surrounded by dual cross flow/Banki turbines. It is also important to obtain the efficient design parameters of the turbines to use in the current configuration. The appropriate angle is important in order to guide the flow to touch the blades more perpendicularly to capture as much torque and power as possible. Hence, experimental and numerical investigations have been carried out in this research paper to study the performance characteristics of the CFT configuration applied in BDA system and investigate the effects of blades’ inlet and outlet angles of CFT runners on the internal flow characteristics and efficiency. In this study, four different runners with various inlet and outlet angles of two CFT have been investigated. The CFD results have been validated with the experimental work and proven acceptable with flow pattern and performance characteristics. The results of the current study conclude that the maximum power coefficients (Cp) of 0.612 and 0.473 for lower and upper turbines are recorded for best runner angles of Case 3