Electromagnetic nondestructive inspection of aircraft structures by using a magnetic flux leakage method

Aging of aircraft structures is mostly associated with fatigue cracking, de-bonding and corrosion. Detection and characterization of the structural defects at the initiation stages makes it a great challenge for any inspection technology. This study proposes a new solution for the nondestructive evaluation problem by using a magnetic flux method for non-ferromagnetic materials and provides a new neural network tool that predicts crack profiles in three dimensions by solving the inverse problem, where available neural networks can solve it in two dimensions only.;The discontinuity resulting from a crack produces disturbance to the distribution of electrical current density in the structure and as a result the magnetic field around the crack will change. The magnitude of the disturbance is determined by the size and shape of the crack. Therefore, it is possible to evaluate the crack area by magnetic field measurements. The magnetic fields from the plate edges and the wires that carry the current are very strong compared to the magnetic field produced by the crack. A new plate, called a dummy plate, is used to minimize the effect of the magnetic fields produced by the plate edges. This study proves the effectiveness of the dummy plate and shows the measurable change in the magnetic signal around the crack.;As a result of this work, a tool is now available that can solve the nondestructive evaluation problem and the inverse problem in three dimensions and has the capability to provide an enhanced assessment tool for judgment and decision-making which will improve the safety of metallic structures and save people lives

Predictive maintenance of rotational machinery using deep learning

This paper describes an implementation of a deep learning-based predictive maintenance (PdM) system for industrial rotational machinery, built upon the foundation of a long short-term memory (LSTM) autoencoder and regression analysis. The autoencoder identifies anomalous patterns, while the latter, based on the autoencoder’s output, estimates the machine’s remaining useful life (RUL). Unlike prior PdM systems dependent on labelled historical data, the developed system doesn’t require it as it’s based on an unsupervised deep learning model, enhancing its adaptability. The paper also explores a robust condition monitoring system that collects machine operational data, including vibration and current parameters, and transmits them to a database via a Bluetooth low energy (BLE) network. Additionally, the study demonstrates the integration of this PdM system within a web-based framework, promoting its adoption across various industrial settings. Tests confirm the system's ability to accurately identify faults, highlighting its potential to reduce unexpected downtime and enhance machinery reliability

Effect of Sand Percentage on the Compaction Properties and Undrained Shear Strength of Low Plasticity Clay

This paper investigates the influence of sand content on the mechanical behavior of a low plasticity clay that collected from south of Iraq (Sumer town). Samples have been prepared with sand contents of 0%, 10%, 20%, 30%, and 40% of the clay weight. Standard Proctor and unconfined compression tests have been carried out and the optimum moisture content, maximum dry density, and undrained shear strength have been determined. The results show a gradual increasing trend of the maximum dry density with the increase of the sand content up to 30%. The highest dry density reaches 1.90 g/cm3 corresponding to an optimum moisture content of 12%. In addition, this paper shows that the undrained shear strength is inversely proportional to the increase of the percentage of sand. The results of this work provide a useful addition to the literature regarding the behaviour or low plasticity clay-sand mixture

The Impact Of Budget Participation On Work-Information Availability -The Role Of Organizational Commitment, Distributive Fairness And Satisfaction- -An Empirical Study On The Agricultural Firms-

The main objective of this study is to examine the direct impact of the relationship between information availability needed to prepare budget and participating in budget preparation process, as well as the indirect impact of this relationship. More specifically, this study will examine the impact of participating in budget preparation process on psychological factors of the participants such as commitment, justice and satisfaction. Besides, this study will further examine the impact of these factors on information availability. To achieve the study objectives, a questionnaire was used and distributed on the Agricultural Firms in the Syrian Coast. This questionnaire was distributed to 72 respondents, but only 50 questionnaires were completed and received. The results show a positive impact of the relationship between information availability needed to prepare budget and participating in budget preparation process, as well as a positive impact of participating in budget preparation process on psychological factors of the participants. Additionally, the results indicate a positive impact of the information content of psychological factors on participating in budget preparation process. هدفت الدراسة إلى تحديد الأثر المباشر للمشاركة في إعداد الموازنة على توافر المعلومات اللازمة للقيام بالعمل, ثم تحديد الأثر غير المباشر لهذه العلاقة؛ وذلك من خلال دراسة أثر المشاركة في إعداد الموازنة على العامل النفسي للمشاركين, والمتمثل بالشعور بالالتزام وبالعدالة وبدرجة الرضا, فضلاً عن تحديد أثر كل من هذه المتغيرات على توافر المعلومات. لذلك تمَّ إجراء مسح ميداني باستخدام الاستبانة على منشآت القطاع الزراعي العامة العاملة في الساحل السوري, إذ تمَّ توزيع /72/ استبانة, استرجع منها /50/ استبانة. وقد أظهرت نتائج تحليل البيانات وجود تأثير إيجابي للمشاركة في إعداد الموازنة على توافر المعلومات, وتأثير إيجابي للمشاركة في إعداد الموازنة على متغيرات الجانب النفسي الناتجة عن هذه المشاركة, فضلاً عن وجود تأثير إيجابي جداً لهذه المتغيرات على الجانب المعلوماتي المرتبط بعملية المشاركة

Use of hydrophilic and hydrophobic polymers for the development of controlled release tizanidine matrix tablets

The aim of the present study was to develop tizanidine controlled release matrix. Formulations were designed using central composite method with the help of design expert version 7.0 software. Avicel pH 101 in the range of 14-50% was used as a filler, while HPMC K4M and K100M in the range of 25-55%, Ethylcellulose 10 ST and 10FP in the range of 15 - 45% and Kollidon SR in the range of 25-60% were used as controlled release agents in designing different formulations. Various physical parameters including powder flow for blends and weight variation, thickness, hardness, friability, disintegration time and in-vitro release were tested for tablets. Assay of tablets were also performed as specified in USP 35 NF 32. Physical parameters of both powder blend and compressed tablets such as compressibility index, angle of repose, weight variation, thickness, hardness, friability, disintegration time and assay were evaluated and found to be satisfactory for formulations K4M2, K4M3, K4M9, K100M2, K100M3, K100M9, E10FP2, E10FP9, KSR2, KSR3 & KSR9. In vitro dissolution study was conducted in 900 ml of 0.1N HCl, phosphate buffer pH 4.5 and 6.8 medium using USP Apparatus II. In vitro release profiles indicated that formulations prepared with Ethocel 10 standard were unable to control the release of drug while formulations K4M2, K100M9, E10FP2 & KSR2 having polymer content ranging from 40-55% showed a controlled drug release pattern in the above mentioned medium. Zero-order drug release kinetics was observed for formulations K4M2, K100M9, E10FP2 & KSR2. Similarity test (f 2) results for K4M2, E10FP2 & KSR2 were found to be comparable with reference formulation K100M9. Response Surface plots were also prepared for evaluating the effect of independent variable on the responses. Stability study was performed as per ICH guidelines and the calculated shelf life was 24-30 months for formulation K4M2, K100M9 and E10FP2.O objetivo do presente estudo foi desenvolver matriz de de tizanidina de liberação controlada. As formulações foram projetadas usando o método do componente, central com a ajuda de software Design expert(r), versão 7.0. Utilizou-se Avicel pH 101, no intervalo de 14-50%, como material de preenchimento, enquanto HPMC K4M e K100M, no intervalo de 25-55%, Etilcelulose 10 ST e 10FP, no intervalo de 15-45% e Kollidon SR, na faixa de 25-60% foram utilizados como agentes de liberação controlada, no planejamento de formulações diferentes. Vários parâmetros físicos, incluindo o fluxo de pó para as misturas e variação de peso, espessura, dureza, friabilidade, tempo de desintegração e liberação in vitro, foram testados para comprimidos. Ensaios dos comprimidos foram, também, realizados, tal como especificado em USP 35 NF 32. Avaliaram-se os parâmetros físicos de ambos, mistura em pó e comprimidos, como índice de compressibilidade, ângulo de repouso, variação de peso, espessura, dureza, friabilidade, tempo de desintegração e de ensaio, considerando-os satisfatórios para as formulações K4M2, K4M3, K4M9, K100M2, K100M3, K100M9, E10FP2, E10FP9, KSR2, KSR3 e KSR9. O estudo de dissolução in vitro foi realizado em 900 mL de HCl 0,1 N, tampão de fosfato pH 4,5 e meio 6,8, usando aparelho USP II. Os perfis de liberação in vitro indicaram que as formulações preparadas com Ethocel 10 padrão não foram capazes de controlar a liberação do fármaco, enquanto as formulações K4M2, K100M9, E10FP2e KSR2, com teor de polímero variando entre 40 e 55% apresentaram padrão de liberação controlada de fármaco no meio anteriormente mencionado. Observou-se cinética de liberação de fármaco de ordem zero para as formulações K4M2 , K100M9, E10FP2 e KSR2. Resultados do teste de similaridade (f 2) para K4M2, E10FP2 e KSR2 foram comparáveis com a formulação de referência K100M9. Gráficos de superfície de resposta também avaliaram o efeito da variável independente sobre as respostas. Estudo de estabilidade foi realizado conforme as diretrizes do ICH e a vida de prateleira calculada foi de 24-30 meses para as formulações K4M2, K100M9 e E10FP2

Sleep habits and sleep problems among Palestinian students

<p>Abstract</p> <p>Aim</p> <p>The aim of this study was to describe sleep habits and sleep problems in a population of undergraduates in Palestine. Association between self-reported sleep quality and self-reported academic achievement was also investigated.</p> <p>Methods</p> <p>Sleep habits and problems were investigated using a convenience sample of students from An-Najah National University, Palestine. The study was carried out during spring semester, 2009. A self-administered questionnaire developed based on The Diagnostic and Statistical Manual of Mental Disorders IV criteria and Pittsburgh Sleep Quality Index was used.</p> <p>Results</p> <p>400 students with a mean age of 20.2 ± 1.3 were studied. Reported mean duration of night sleep in the study sample was 6.4 ± 1.1 hours. The majority (58.3%) of students went to bed before midnight and 18% of the total sample woke up before 6 am. Sleep latency of more than one hour was present in 19.3% of the students. Two thirds (64.8%) of the students reported having at least one nocturnal awakening per night. Nightmares were the most common parasomnia reported by students. Daytime naps were common and reported in 74.5% of the study sample. Sleep quality was reported as "poor" in only 9.8% and was significantly associated with sleep latency, frequency of nocturnal awakenings, time of going to bed, nightmares but not with academic achievement.</p> <p>Conclusion</p> <p>Sleep habits among Palestinian undergraduates were comparable to those reported in European studies. Sleep problems were common and there was no significant association between sleep quality and academic achievement.</p

Formulation development and optimization of cefuroxime axetil tablets by direct compression method and its stability studies

Cefuroxime axetil (CA) immediate release (IR) tablets were developed and optimized by direct compression method. Ten formulations were designed and optimized using central composite design with two main variables, microcrystalline cellulose PH 102 and croscarmellose. Pharmaceutical evaluation of the formulations was conducted emphasizing on dissolution profile of the drug by USP dissolution test using apparatus II in 0.07 N HCl and in medium of pH 1.2, 4.5 and 6.8 to determine the dissolution pattern of the low soluble drug. Test formulations were compared against reference brand using f2 similarity factor. Test formulations were assayed by a validated HPLC method, with acetonitrile and 10 mM ammonium acetate solution (pH = 5.2) in a ratio of 15:85 as mobile phase. Stability studies under stress were conducted on selected formulations according to ICH guidelines. It was conclusive that stable CA formulations could be developed by direct compression method.Colegio de Farmacéuticos de la Provincia de Buenos Aire