Search results for: materials chemistry

Authors: Fares Khalfallah, Zakaria Boumerzoug, Selvarajan Rajakumar, Elhadj Raouache

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The ceramic-aluminum bond is strongly present in industrial tools, due to the need to combine the properties of metals, such as ductility, thermal and electrical conductivity, with ceramic properties like high hardness, corrosion and wear resistance. In recent years, some joining techniques have been developed to achieve a good bonding between these materials such as brazing, diffusion bonding, ultrasonic joining and friction welding. In this work, AA1100 aluminum alloy rods were welded with Alumina 99.9 wt% ceramic rods, by friction welding. The effect of friction pressure on mechanical and structural properties of welded joints was studied. The welding was performed by direct friction welding machine. The welding samples were rotated at a constant rotational speed of 900 rpm, friction time of 4 sec, forging strength of 18 MPa, and forging time of 3 sec. Three different friction pressures were applied to 20, 34 and 45 MPa. The three-point bending test and Vickers microhardness measurements were used to evaluate the strength of the joints and investigate the mechanical properties of the welding area. The microstructure of joints was examined by optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that bending strength increased, and then decreased after reaching a maximum value, with increasing friction pressure. The SEM observation shows that the increase in friction pressure led to the appearance of cracks in the microstructure of the interface area, which is decreasing the bending strength of joints.

Keywords: welding of ceramic to aluminum, friction welding, alumina, AA1100 aluminum alloy

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Authors: Kizito Ugochukwu Nwajeria

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This paper presents a spectral quasi-linearization technique (SQLT) for solving time fractional diffusion wave equations in boundary value problems. The proposed method integrates spectral approximations for spatial derivatives with a quasi-linearization approach to address the nonlinearity introduced by fractional time derivatives. Time fractional differential equations typically formulated using Caputo or Riemann-Liouville derivatives, model complex phenomena such as anomalous diffusion and wave propagation, which are not captured by classical integer-order models. The SQLT method iteratively linearizes the nonlinear terms at each time step, transforming the original problem into a series of linear subproblems, which can be efficiently solved. Using high-order spectral methods such as Chebyshev or Legendre polynomials for spatial discretization, the technique achieves high accuracy in approximating the solution. A convergence analysis is provided, demonstrating the method's efficiency and establishing error bounds. Numerical experiments on a range of test problems confirm the effectiveness of SQLT in solving fractional diffusion wave equations with various boundary conditions. The method offers a robust framework for addressing time fractional differential equations in diverse fields, including materials science, bioengineering, and anomalous transport phenomena.

Keywords: spectral methods, quasilinearization, time-fractional diffusion-wave equations, boundary value problems, fractional calculus

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Authors: Ktiri Fouad

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Objectives: The present study examined how the polyvalent nursing students of the Higher Institute of Nursing Professions and Health Techniques (ISPITS-Rabat-Morocco) conceived the term "feeling stressed.” We checked whether they were referring to a specific type of sensation (emotional, mental, physical) or both or all of them when they said they were stressed at the time they felt it. Materials and methods: A quantitative cross-sectional study was conducted among students of the three years of polyvalent nursing courses. Using a 7-Likert scale, the students were asked to assess their states of stress and the emotional, mental and physical sensations they were experiencing before and after carrying out a mental arithmetic task. An ordinal logistic regression method was used to investigate the association between the states of stress and the 3 types of sensations. Results: 222 polyvalent nursing students out of 307 were included in the experience. Their increased perceived states of stress after carrying out the mental task were found to be significantly associated with emotional distress and mental fatigue and not with physical tiredness. The mental sensation (mental fatigue) was found to have more effects in predicting the likelihood of feeling stressed. In addition, the lower the intensity of emotional or mental sensation, the more likely the students were to experience stress, given that one of both sensations is held constant, whatever the intensity of the physical sensation. We conclude that the polyvalent nursing students refer to mental fatigue and emotional distress and not to physical tiredness when they say they felt stressed, the mental fatigue having more effects. The implications of the study are discussed.

Keywords: feeling stressed”, emotional sensation, mental sensation, physical sensation

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Authors: Kangujam Monika, Kiranbala Devi Thokchom, Soibam Sandhyarani Devi

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Earthquake is a major natural hazard in India. Manipur, located in the North-Eastern Region of India, is one of the most affected location in the region prone to earthquakes since it lies in an area where Indian and Eurasian tectonic plates meet and is in seismic Zone V which is the most severe intensity zone, according to IS Code. Some recent earthquakes recorded in Manipur are M 6.7 epicenter at Tamenglong (January 4, 2016), M 5.2 epicenter at Churachandpur (February 24, 2017) and most recent M 4.4 epicenter at Thoubal (June 19, 2017). In these recent earthquakes, some houses and buildings were damaged, landslides were also occurred. A field study was carried out. An overview of the various causal factors involved in triggering of earthquake in Manipur has been discussed. It is found that improper planning, poor design, negligence, structural irregularities, poor quality materials, construction of foundation without proper site soil investigation and non-implementation of remedial measures, etc., are possibly the main causal factors for damage in Manipur during earthquake. The study also suggests, though the proper design of structure and foundation along with soil investigation, ground improvement methods, use of modern techniques of construction, counseling with engineer, mass awareness, etc., might be effective solution to control the hazard in many locations. An overview on the analysis pertaining to earthquake in Manipur together with on-going detailed site specific geotechnical investigation were presented.

Keywords: Manipur, earthquake, hazard, structure, soil

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Authors: Nazih Ramadan, Manal Mohy-Eldine, Amani Hanoon, Alaa Shehab

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Background and Aims: The study of fingerprints is widely used in providing a clue regarding identity. Age and gender identification from fingerprints is an important step in forensic anthropology in order to minimize the list of suspects search. The aim of this study was to determine finger ridge density and patterns among Egyptians, and to estimate age and gender using ridge densities. Materials and Methods: This study was conducted on 177 randomly-selected healthy Egyptian subjects (90 males and 87 females). They were divided into three age groups; Group (a): from 6-< 12 years, group (b) from 12-< 18 years and group (c) ≥ 18 years. Bilateral digital prints, from every subject, were obtained by the inking procedure. Ridge count per 25 mm² was determined together with assessment of ridge pattern type. Statistical analysis was done with references to different age and sex groups. Results: There was a statistical significant difference in ridge density between the different age groups; where younger ages had significantly higher ridge density than older ages. Females proved to have significantly higher ridge density than males. Also, there was a statistically significant negative correlation between age and ridge density. Ulnar loops were the most frequent pattern among Egyptians then whorls then arches then radial loops. Finally, different regression models were constructed to estimate age and gender from fingerprints ridge density. Conclusion: fingerprint ridge density can be used to identify both age and sex of subjects. Further studies are recommended on different populations, larger samples or using different methods of fingerprint recording and finger ridge counting.

Keywords: age, sex identification, Egyptian population, fingerprints, ridge density

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Authors: Aboagye Boye Gilbert

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Teaching and learning (Education), not only in Ghana but the whole world is regarded as the (Stepping stone) vehicle to accelerate the country’s economy, development and social growth. Basically the ingredients for human development and the country in general is Vocational and Technical education and this has been stressed in Ghana’s education system since Pre-independence. To this effect, this research seeks to determine using demonstration method of Teachings sewing to improve the skills of form 3 Fashion Designing students of Baworo Integrated Community Centre for Employable Skills. In this research, reviewed literature on opinions of other researchers and what other people have done and said on related articles or topics, analyzed the research design used, translate the data gathered in the study. The study was design to gather information from the school on how they use Teaching methods to teach sewing. The targeted respondent contacted to give assistance Consist of students from BICCES, fashion teachers and tailored garment makers. The sample size consisted of 5 teachers, 20 students and 5 tailors were selected to answer questionnaire items that were used to gather the data for the study. The study revealed that most teachers and students agreed to the fact that demonstration, teaching and learning materials had a positive attitude towards the students in learning sewing. The study recommends that there should be more mechanisms in place to serve as a guide.

Keywords: VOTEC, BECE, BICCES, SHS

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Authors: K. H. Teng, A. Shaw, M. Ateeq, A. Al-Shamma'a, S. Wylie, S. N. Kazi, B. T. Chew

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Numerical and experimental of using novel electromagnetic wave technique to detect water hardness concentration has been presented in this paper. Simulation is powerful and efficient engineering methods which allow for a quick and accurate prediction of various engineering problems. The RF module is used in this research to predict and design electromagnetic wave propagation and resonance effect of a guided wave to detect water hardness concentration in term of frequency domain, eigenfrequency, and mode analysis. A cylindrical cavity resonator is simulated and designed in the electric field of fundamental mode (TM010). With the finite volume method, the three-dimensional governing equations were discretized. Boundary conditions for the simulation were the cavity materials like aluminum, two ports which include transmitting and receiving port, and assumption of vacuum inside the cavity. The design model was success to simulate a fundamental mode and extract S21 transmission signal within 2.1 – 2.8 GHz regions. The signal spectrum under effect of port selection technique and dielectric properties of different water concentration were studied. It is observed that the linear increment of magnitude in frequency domain when concentration increase. The numerical results were validated closely by the experimentally available data. Hence, conclusion for the available COMSOL simulation package is capable of providing acceptable data for microwave research.

Keywords: electromagnetic wave technique, frequency domain, signal spectrum, water hardness concentration

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Authors: Mohammad Shabani

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The physical activities depending on the nature of the mechanical stresses they induce on bone sometimes have brought about different results. The purpose of this study was to compare bone mineral density (BMD) of the lumbar spine between the high-level cyclists and sedentary. Materials and Methods: In the present study, 73 cyclists senior (age: 25.81 ± 4.35 years; height: 179.66 ± 6.31 cm; weight: 71.55 ± 6.31 kg) and 32 sedentary subjects (age: 28.28 ± 4.52 years; height: 176.56 ± 6.2 cm; weight: 74.47 ± 8.35 kg) participated voluntarily. All cyclists belonged to the different teams from the International Cycling Union and they trained competitively for 10 years. BMD of the lumbar spine of the subjects was measured using DXA X-ray (Lunar). Descriptive statistics calculations were performed using computer software data processing (Statview 5, SAS Institute Inc. USA). The comparison of two independent distributions (BMD high level cyclists and sedentary) was made by the Student T Test standard. Probability 0.05 (p≤0 / 05) was adopted as significance. Results: The result of this study showed that the BMD values of the lumbar spine of sedentary subjects were significantly higher for all measured segments. Conclusion and Discussion: Cycling is firstly a common sport and on the other hand endurance sport. It is now accepted that weight bearing exercises have an osteogenic effect compared to non-weight bearing exercises. Thus, endurance sports such as cycling, compared to the activities imposing intense force in short time, seem not to really be osteogenic. Therefore, it can be concluded that cycling provides low stimulates osteogenic because of specific biomechanical forces of the sport and its lack of impact.

Keywords: BMD, lumbar spine, high level cyclist, cycling

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Authors: Jessevel Montes

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This study explored on the culture of journal writing among the Senior High School Manobo students. The purpose of this qualitative morpho-semantic and syntactic study was to discover the morphological, semantic, and syntactic features of the written output through morphological, semantic, and syntactic categories present in their journal writings. Also, beliefs and practices embedded in the norms, values, and ideologies were identified. The study was conducted among the Manobo students in the Senior High Schools of Central Mindanao, particularly in the Division of North Cotabato. Findings revealed that morphologically, the features that flourished are the following: subject-verb concordance, tenses, pronouns, prepositions, articles, and the use of adjectives. Semantically, the features are the following: word choice, idiomatic expression, borrowing, and vernacular. Syntactically, the features are the types of sentences according to structure and function; and the dominance of code switching and run-on sentences. Lastly, as to the beliefs and practices embedded in the norms, values, and ideologies of their journal writing, the major themes are: valuing education, family, and friends as treasure, preservation of culture, and emancipation from the bondage of poverty. This study has shed light on the writing capabilities and weaknesses of the Manobo students when it comes to English language. Further, such an insight into language learning problems is useful to teachers because it provides information on common trouble-spots in language learning, which can be used in the preparation of effective teaching materials.

Keywords: applied linguistics, culture, morpho-semantic and syntactic analysis, Manobo Senior High School, Philippines

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Authors: M. Venkateswarlu, Srinivasa Rao Allam, S. K. Mahamuda, K. Swapna, G. Vijaya Prakash

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Lead Tungsten Tellurite (LTT) glasses doped with different concentrations of Tm3+ ions were prepared by using melt quenching technique and characterized through optical absorption, photoluminescence and decay spectral studies to know the feasibility of using these glasses as luminescent devices in visible Red and NIR regions. By using optical absorption spectral data, the energy band gaps for all the glasses were evaluated and were found to be in the range of 2.34-2.59 eV; which is very useful for the construction of optical devices. Judd-Ofelt (J-O)theory has been applied to the optical absorption spectral profiles to calculate the J-O intensity parameters Ωλ (λ=2, 4 and 6) and consecutively used to evaluate various radiative properties such as radiative transition probability (AR), radiative lifetimes (τ_R) and branching ratios (β_R) for the prominent luminescent levels. The luminescence spectra for all the LTT glass samples have shown two intense peaks in bright red and Near Infrared regions at 650 nm (1G4→3F4) and 800 nm (3H4→3H6) respectively for which effective bandwidths (〖Δλ〗_P), experimental branching ratios (β_exp) and stimulated emission cross-sections (σ_se) are evaluated. The decay profiles for all the glasses were also recorded to measure the quantum efficiency of the prepared LTT glasses by coupling the radiative and experimental lifetimes. From the measured emission cross-sections, quantum efficiency and CIE chromaticity coordinates, it was found that 0.5 mol% of Tm3+ ions doped LTT glass is most suitable for generating bright visible red and NIR lasers to operate at 650 and 800 nm respectively.

Keywords: glasses, JO parameters, optical materials, thullium

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Authors: Ananya Mitra Pramanik, Anjali Agrawal

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The objective of this paper is to trace the origin and evolution of clothing in the Indian Subcontinent. The paper seeks to understand the need for mankind to shed his natural state and adopt clothing as an inseparable accessory for his body. It explores the various theories of the origin of clothing. The known journey of clothing of this region started from the Indus Valley Civilisation which dates back to 2500 BC. Due to the weather conditions of the region, few actual samples have survived, and most of the knowledge of textiles is derived from the sculptures and other remains from this era. The understanding of textiles of the period after the Indus Valley Civilisation (2500-1500 BC) till the Mauryan and the Sunga Period (321-72 BC) comes from literary sources, e.g., Vedas, Smritis, the eminent Indian epics of the Ramayana and the Mahabharata, forest books, etc. Textile production was one of the most important economic activities of this region. It was next only to agriculture. While attempting to trace the history of clothing the paper draws the evolution of Indian traditional fashion through the change of rulers of this region and the development of the modern Indian traditional dress, i.e., sari, salwar kamiz, dhoti, etc. The major aims of the study are to define the different time periods chronologically and to inspect the major changes in textile fashion, manufacturing, and materials that took place. This study is based on secondary research. It is founded on data taken primarily from books and journals. Not much of visuals are added in the paper as actual fabric references are near nonexistent. It gives a brief history of the ancient textiles of India from the time frame of 2500 BC-8th C AD.

Keywords: evolution, history, origin, textiles

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Authors: Mi-Hyang Lee, Seung-Hoon Han

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Korean traditional residences have been built with deep design issues for various values such as social, cultural, and environmental influences to be started from a few thousand years ago, but its meaning is being vanished due to the different lifestyles these days. It is necessary, therefore, to grasp the meaning of the Korea traditional building called Hanok and to get Korean people understand its real advantages. The purpose of this study is to propose a standardization methodology for evaluating comfort features towards Korean traditional houses. This paper is also trying to build an official standard evaluation system and to integrate aesthetic and psychological values induced from Hanok. Its comfort performance values could be divided into two large categories that are physical and psychological, and fourteen methods have been defined as the Korean Standards (KS). For this research, field survey data from representative Hanok types were collected for each method. This study also contains a qualitative in-depth analysis of the Hanok comfort index by the professions using AHP (Analytical Hierarchy Process) and has examined the effect of the methods. As a result, this paper could define what methods can provide trustful outcomes and how to evaluate the own strengths in aspects of spatial comfort of Hanok using suggested procedures towards the spatial configuration of the traditional dwellings. This study has finally proposed an integrated development of a standardization methodology assessing the comfort performance for Korean traditional residences, and it is expected that they could evaluate inhabitants of the residents and interior environmental conditions especially structured by wood materials like Hanok.

Keywords: Hanok, comfort performance, human condition, analytical hierarchy process

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Authors: Soroush Hooshyar, Mohamadali Masoudian, Natalie Germann

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Many soft materials such as polymer solutions can develop localized bands with different shear rates, which are known as shear bands. Using the generalized bracket approach of nonequilibrium thermodynamics, we recently developed a new two-fluid model to study shear banding for semi-dilute polymer solutions. The two-fluid approach is an appropriate means for describing diffusion processes such as Fickian diffusion and stress-induced migration. In this approach, it is assumed that the local gradients in concentration and, if accounted for, also stress generate a nontrivial velocity difference between the components. Since the differential velocity is treated as a state variable in our model, the implementation of the boundary conditions arising from the derivative diffusive terms is straightforward. Our model is a good candidate for benchmark simulations because of its simplicity. We analyzed its behavior in cylindrical Couette flow, a rectilinear channel flow, and a 4:1 planar contraction flow. The latter problem was solved using the OpenFOAM finite volume package and the impact of shear banding on the lip and salient vortices was investigated. For the other smooth geometries, we employed a standard Chebyshev pseudospectral collocation method. The results showed that the steady-state solution is unique with respect to initial conditions, deformation history, and the value of the diffusivity constant. However, smaller the value of the diffusivity constant is, the more time it takes to reach the steady state.

Keywords: nonequilibrium thermodynamics, planar contraction, polymer solutions, shear banding, two-fluid approach

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Authors: L. Freeborn

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Recent years have seen an increasing number of neuroimaging studies related to language learning as imaging techniques such as fMRI and EEG have become more widely accessible to researchers. By using a variety of structural and functional neuroimaging techniques, these studies have already made considerable progress in terms of our understanding of neural networks and processing related to first and second language acquisition. However, the methodological designs employed in neuroimaging studies to test language learning have been questioned by applied linguists working within the field of second language acquisition (SLA). One of the major criticisms is that tasks designed to measure language learning gains rarely have a communicative function, and seldom assess learners’ ability to use the language in authentic situations. This brings the validity of many neuroimaging tasks into question. The fundamental reason why people learn a language is to communicate, and it is well-known that both first and second language proficiency are developed through meaningful social interaction. With this in mind, the SLA field is in agreement that second language acquisition and proficiency should be measured through learners’ ability to communicate in authentic real-life situations. Whilst authenticity is not always possible to achieve in a classroom environment, the importance of task authenticity should be reflected in the design of language assessments, teaching materials, and curricula. Tasks that bear little relation to how language is used in real-life situations can be considered to lack construct validity. This paper first describes the typical tasks used in neuroimaging studies to measure language gains and proficiency, then analyses to what extent these tasks can validly assess these constructs.

Keywords: neuroimaging studies, research design, second language acquisition, task validity

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Authors: Seon Yeong Byeon, Hwa Sung Shin

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Nanofibrous sheets are of interest in the beauty industries due to the properties of moisturizing, adhesion to skin and delivery of nutrient materials. The benefit and function of the cosmetic products should not be considered without safety thus a non-toxic manufacturing process is ideal when fabricating the products. In this study, we have developed cosmetic patches consisting of alginate and Spirulina extract, a marine resource which has antibacterial and antioxidant effects, without addition of harmful cross-linkers. The patches obtained their structural stabilities by layer-upon-layer electrospinning of an alginate layer on a formerly spread polycaprolactone (PCL) layer instead of crosslinking method. The morphological characteristics, release of Spirulina extract, water absorption, skin adhesiveness and cytotoxicity of the double-layered patches were assessed. The image of scanning electron microscopy (SEM) showed that the addition of Spirulina extract has made the fiber diameter of alginate layers thinner. Impregnation of Spirulina extract increased their hydrophilicity, moisture absorption ability and skin adhesive ability. In addition, wetting the pre-dried patches resulted in releasing the Spirulina extract within 30 min. The patches were detected to have no cytotoxicity in the human keratinocyte cell-based MTT assay, but rather showed increased cell viability. All the results indicate the bioactive and hydro-adhesive double-layered patches have an excellent applicability to bioproducts for personal skin care in the trend of ‘A mask pack a day’.

Keywords: alginate, cosmetic patch, electrospun nanofiber, polycaprolactone, Spirulina extract

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Authors: Karoline Reis de Sena

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Endocrine disruptors are unregulated or not fully regulated compounds, even in the most developed countries, and which can be a danger to the environment and human health. They pass untreated through the secondary stage of conventional wastewater treatment plants, then the effluent from the wastewater treatment plants is discharged into the rivers, upstream and downstream from the drinking water treatment plants that use the same river water as the tributary. Long-term consumption of drinking water containing low concentrations of these compounds can cause health problems; these are persistent in nature and difficult to remove. In this way, research on emerging pollutants is expanding and is fueled by progress in finding the appropriate method for treating wastewater. Adsorption is the most common separation process, it is a simple and low-cost operation, but it is not eco-efficient. Concomitant to this, biosorption arises, which is a subcategory of adsorption where the biosorbent is biomass and which presents numerous advantages when compared to conventional treatment methods, such as low cost, high efficiency, minimization of the use of chemicals, absence of need for additional nutrients, biosorbent regeneration capacity and the biomass used in the production of biosorbents are found in abundance in nature. Thus, the use of alternative materials, such as sewage sludge, for the synthesis of adsorbents has proved to be an economically viable alternative, together with the importance of valuing the generated by-product flows, as well as managing the problem of their correct disposal. In this work, an alternative for the management of sewage sludge is proposed, transforming it into activated carbon and using it in the adsorption process of 17a-ethinylestradiol.

Keywords: 17α-ethinylestradiol, adsorption, activated carbon, sewage sludge, micropollutants

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Authors: Komal Saeed

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Introduction: Rhinoplasty is considered one of the challenging aesthetic procedures. Psychosocial concerns motivate the urge for aesthetic procedures especially rhinoplasty. Males who fall in this category are designated as single, immature, male, over expectant and narcissistic (SIMON) in literature. As of yet, there is no term that depicts females showing similar characteristics. The purpose of this study is to evaluate the incidence of body dysmorphic disorder (BDD) in females seeking rhinoplasty and to introduce a term for such individuals. Materials and Methods: A prospective, questionnaire based, qualitative study was conducted in the Department Of Plastic Surgery between March 2018 and March 2020. 110 female candidates seeking aesthetic rhinoplasty were included in the study. BDD was evaluated using the Dysmorphic Concerns Questionnaire, DCQ. Data were analyzed using SPSS version 25 software and correlation between the groups was evaluated. Results: Out of 110 female subjects, 77.3% (n=85) were single, 16.4% (n=18) were married and 6.4% (n=7) were divorced. BDD was found in 41.8% (n=46) of the candidates, majority being single (n=41, 89.1%) and having educational status above diploma (n=39, 84.8%). There was a statistically higher percentage of young adults between 24 and 28 years (n=33, 71.7%) having BDD (p= 0.0001). Conclusion: Considering the high frequency of BDD among females seeking rhinoplasty, a standardized term ‘SIFON’ is introduced to describe such individuals who are S; single, I; immature, F; female, O; over expectant, N; narcissistic as apposed to SIMON in males. These individuals perceive aesthetic procedures as a solution to their body dissatisfaction. Therefore, preoperative counseling seems necessary to avoid unsatisfactory outcomes secondary to mental health.

Keywords: aesthetic rhinoplasty, body dismorphic disorder, single, immature, obsessive

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Authors: Sylvia Tumelo Nthutang, Nehemiah Mavetera

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Educational institutions are under pressure from their competitors. Regulators and community groups need educational institutions to adopt appropriate business and organizational practices. Globally, educational institutions are now using e-learning as the best teaching and learning approach. E-learning is becoming the center of attention to the learning institutions, educational systems and software inventors. North-West University (NWU) is currently using eFundi, a Learning Management System (LMS). LMS are all information systems and procedures that adds value to students learning and support the learning material in text or any multimedia files. With various e-learning tools, students would be able to access all the materials related to the course in electronic copies. The study was tasked with identifying the e-learning components at the NWU, Mafikeng campus. Quantitative research methodology was considered in data collection and descriptive statistics for data analysis. The Activity Theory (AT) was used as a theory to guide the study. AT outlines the limitations amongst e-learning at the macro-organizational level (plan, guiding principle, campus-wide solutions) and micro-organization (daily functioning practice, collaborative transformation, specific adaptation). On a technological environment, AT gives people an opportunity to change from concentrating on computers as an area of concern but also understand that technology is part of human activities. The findings have identified the university’s current IT tools and knowledge on e-learning elements. It was recommended that university should consider buying computer resources that consumes less power and practice e-learning effectively.

Keywords: e-learning, information and communication technology (ICT), teaching, virtual learning environment

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Authors: Javid Iqbal, Zhu Shifan

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The development in the construction of unconventional ships and the implementation of lightweight materials have shown a large impulse towards finite element (FE) method, making it a general tool for ship design. This paper briefly presents the modeling and analysis techniques of ship structures using FE method for complex boundary conditions which are difficult to analyze by existing Ship Classification Societies rules. During operation, all ships experience complex loading conditions. These loads are general categories into thermal loads, linear static, dynamic and non-linear loads. General strength of the ship structure is analyzed using static FE analysis. FE method is also suitable to consider the local loads generated by ballast tanks and cargo in addition to hydrostatic and hydrodynamic loads. Vibration analysis of a ship structure and its components can be performed using FE method which helps in obtaining the dynamic stability of the ship. FE method has developed better techniques for calculation of natural frequencies and different mode shapes of ship structure to avoid resonance both globally and locally. There is a lot of development towards the ideal design in ship industry over the past few years for solving complex engineering problems by employing the data stored in the FE model. This paper provides an overview of ship modeling methodology for FE analysis and its general application. Historical background, the basic concept of FE, advantages, and disadvantages of FE analysis are also reported along with examples related to hull strength and structural components.

Keywords: dynamic analysis, finite element methods, ship structure, vibration analysis

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Authors: Sadaf Karkoodi, Hassan Karampour

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There is a growing interest in the construction industry towards hybrid systems. The hybrid systems use construction materials such as timber, steel, and concrete smartly, can be prefabricated, and are cost-effective and sustainable solutions to an industry targeting reduced carbon footprint. Moreover, in case of periodical shortage in timber resources, reusable and waste wood such as fibres can be used in the hybrid modules, which facilitates the circular economy. In this research, a hybrid frame is proposed and experimentally validated by introducing dried wood fibre products inside cold-formed steel square hollow sections without using any adhesives. As such, fibre-filled steel tubular (FFST) columns, beams, and 2D frames are manufactured and tested. The results show that the FFST columns have stiffness and strength 44% and 55% higher than cold-formed steel columns, respectively. The bearing strength of the FFST beams shows an increase of 39.5% compared to steel only. The flexural stiffness and strength of the FFST beams are 8.5% and 28% higher than the bare steel beams, respectively. The FFST frame depicted an 18.4% higher ultimate load capacity than the steel-only frame under a mid-point concentrated load. Moreover, the FFST beam-to-column bolted connection showed high ductile performance. The initial results and the proposed simple manufacturing process suggest that the proposed FFST concept can be upscaled and used in real structures.

Keywords: wood fibre, reusing wood, fibre-filled steel, hybrid construction

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Authors: Nasibullina A., Leonov D.

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The ultrasonography method is actively used for the early diagnosis of various le-sions in the human body, including the mammary gland. The incidence of breast cancer has increased by more than 20%, and mortality by 14% since 2008. The correctness of the diagnosis often directly depends on the qualifications and expe-rience of a diagnostic medical sonographer. That is why special attention should be paid to the practical training of future specialists. Anatomical phantoms are ex-cellent teaching tools because they accurately imitate the characteristics of real hu-man tissues and organs. The purpose of this work is to create a breast phantom for practicing ultrasound diagnostic skills in grayscale and elastography imaging, as well as ultrasound-guided biopsy sampling. We used silicone-like compounds ranging from 3 to 17 on the Shore scale hardness units to simulate soft tissue and lesions. Impurities with experimentally selected concentrations were added to give the phantom the necessary attenuation and reflection parameters. We used 3D modeling programs and 3D printing with PLA plastic to create the casting mold. We developed a breast phantom with inclusions of varying shape, elasticity and echogenicity. After testing the created phantom in B-mode and elastography mode, we performed a survey asking 19 participants how realistic the sonograms of the phantom were. The results showed that the closest to real was the model of the cyst with 9.5 on the 0-10 similarity scale. Thus, the developed breast phantom can be used for ultrasonography, elastography, and ultrasound-guided biopsy training.

Keywords: breast ultrasound, mammary gland, mammography, training phantom, tissue-mimicking materials

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Authors: Pooja Kherudkar, Namdeo Hedaoo

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There are various causes for asphalt pavement distresses which can develop prematurely or with aging in services. These causes are not limited to aging of bitumen binder but include poor quality materials and construction, inadequate mix design, inadequate pavement structure design considering the traffic and lack of preventive maintenance. There is physical evidence available for each type of pavement distress. Distress in asphalt pavements can be categorized in different distress modes like fracture (cracking and spalling), distortion (permanent deformation and slippage), and disintegration (raveling and potholes). This study shows the importance of severity determination of distresses for the selection of appropriate preventive maintenance treatment. Distress analysis of the deteriorated roads was carried out. Four roads of urban flexible pavements from Pune city was selected as a case study. The roads were surveyed to detect the types, to measure the severity and extent of the distresses. Causes of distresses were investigated. The pavement condition rating values of the roads were calculated. These ranges of ratings were as follows; 1 for poor condition road, 1.1 to 2 for fair condition road and 2.1 to 3 for good condition road. Out of the four roads, two roads were found to be in fair condition and the other two were found in good condition. From the various preventive maintenance treatments like crack seal, fog seal, slurry seal, microsurfacing, surface dressing and thin hot mix/cold mix bituminous overlays, the effective maintenance treatments with respect to the surface condition and severity levels of the existing pavement were recommended.

Keywords: distress analysis, pavement condition rating, preventive maintenance treatments, surface distress measurement

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Authors: Iliya Ibrahim Gimba

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The period between the late 18th and early 19th centuries was characterized by conflict of ethnic nationalities in the Benue valley region. This conflict was exacerbated by the introduction of the Fulani jihad that began in Hausa land into the Benue valley region. Fulani in this region launched the Jihad movement which pushed out some ethnic groups from their natural abode or ancestral home to live a nomad live until they could settle and established a stayed in a particular place. The Chamba were being displaced by the Fulani jihad that took place around Faro deo in about 1809. It was from there that most of the Chamba migrated out, some into the Cameroon republic, while others moved into the Benue valley region. Among those that entered into the Benue valley region are the Sama, Kola, Gayam etc, and could be found in Donga local Government area of Taraba state. Those Chamba clan that later on cameo into the Benue Valley are Pyeri, Kashimbila etc. The sudden movement of the Chamba or migrations into the Jukun territory co-in ceded with the period that the Jihad had already had a severe and consequential effect or impact on the Jukun territory cause by Yakubu Ibrahim of Bzuchi, and Buba Yero of Gombe, and Hamaruwa of Muri Emirate. This ne authorities in Kwararafa Kingdom cut the Jukun King out of contact with Borno and Hausa-land. This paper set to examine the chiefdom that the Chamba established right within the Jukun headquarters of Wukari. Sources to be used are published books, Journals, Archival materials, and M.A. Thesis to enable us know the impact of Chamba migrations on the Jukun territory and reactions of the Jukun’s to this new comers.

Keywords: Chamba people, encroachment, migration, ethnic nationalities

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Authors: Cassandra Seery

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During the twentieth century, the notion of child rights at the international level began with the League of Nations’ Geneva Declaration of the Rights of the Child 1924, culminating in the development and adoption of the UN Convention on the Rights of the Child (‘the Convention’) in 1989. A key foundation of child rights lies in the development of the ‘best interests of the child’ principle and its subsequent incorporation into domestic legislation across the globe. This principle has become a key concept in child rights protection and has become a widely recognized principle in the protection of child rights. However, despite its status as the primary operating standard in child and family law and its ‘deepening hold in domestic and international instruments’, the meaning of the ‘best interests of the child’ principle has been criticised as open-ended and vague. This paper explores the evolution and development of the principle in the context of parental separation at international law throughout the 21st century and identifies opportunities for the Nation States to further improve legislative responses in associated child protection cases. An extensive review of relevant United Nations documentation (including instruments, resolutions and comments, jurisprudence, reports, guidelines and policies, training materials and so forth) explores: (i) what progress has been made to further develop the principle at the international level with regard to parental separation; and (ii) what developments participating the Nation States should consider as part of future legal and social policy reforms in this space. It will highlight opportunities for improvement and explore the benefit and relevance of international approaches for the Nation States moving forward.

Keywords: international human rights, best interests of the child, legal and social policy, child rights

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Authors: Ghoul Rachid Brahim

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Introduction: Back pain is a real public health problem with a significant socio-economic impact. It is the consequence of a degeneration of the lumbar intervertebral disc (IVD). This often asymptomatic pathology is compatible with an active life. As soon as it becomes symptomatic, conservative treatment is recommended in the majority of cases. The physical or functional disability is resistant to well-monitored conservative treatment, which justifies a surgical alternative which imposes a well-studied reflection on the objectives to be achieved. Objective: Evaluate the indication and short and medium term contribution of surgery in the management of painful degenerative lumbar disc disease. To prove the effectiveness of surgical treatment in the management of painful lumbar degenerative disc disease. Materials and methods: This is a prospective descriptive mono-centric study without comparison group, comprising a series of 104 patients suffering from lumbar painful degenerative disc disease treated surgically. Retrospective analysis of data collected prospectively. Comparison between pre and postoperative clinical status, by pain self-assessment scores and on the impact on pre and postoperative quality of life (3, 6 to 12 months). Results: This study showed that patients who received surgical treatment had great improvements in symptoms, function and several health-related quality of life in the first year after surgery. Conclusions: The surgery had a significantly positive impact on patients' pain, disability and quality of life. Overall, 97% of the patients were satisfied.

Keywords: degenerative disc disease, intervertebral disc, several health-related quality, lumbar painful

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Authors: Danila Merino, Leandro N. Ludueña, Vera A. Alvarez

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Clays are commonly used to reinforce polymeric materials. In order to modify them, long-chain quaternary-alkylammonium salts have been widely employed. However, the application of these clays in biological fields is limited by the toxicity and poor biocompatibility presented by these modifiers. Meanwhile, soy lecithin, acts as a natural biosurfactant and environment-friendly biomodifier. In this report, we analyse the effect of content of soy lecithin-modified bentonite on the properties of polycaprolactone (PCL) nanocomposites. Commercial grade PCL (CAPA FB 100) was supplied by Perstorp, with Mw = 100000 g/mol. Minarmco S.A. and Melar S.A supplied bentonite and soy lecithin, respectively. Clays with 18, 30 and 45 wt% of organic content were prepared by exchanging 4 g of Na-Bent with 1, 2 and 4 g of soy lecithin aqueous and acid solution (pH=1, with HCl) at 75ºC for 2 h. Then, they were washed and lyophilized for 72 h. Samples were labeled A, B and C. Nanocomposites with 1 and 2 wt.% of each clay were prepared by melt-intercalation followed by compression-moulding. An intensive Brabender type mixer with two counter-rotating roller rotors was used. Mixing temperature was 100 ºC; speed of rotation was 100 rpm. and mixing time was 10 min. Compression moulding was carried out in a hydraulic press under 75 Kg/mm2 for 10 minutes at 100 ºC. The thickness of the samples was about 1 mm. Thermal and mechanical properties were analysed. PCL nanocomposites with 1 and 2% of B presented the best mechanical properties. It was observed that an excessive organic content produced an increment on the rigidity of PCL, but caused a detrimental effect on the tensile strength and elongation at break of the nanocomposites. Thermogravimetrical analyses suggest that all reinforced samples have higher resistance to degradation than neat PCL.

Keywords: chemical modification, clay, nanocomposite, characterization

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Authors: Snowie Jane Galgo, Victor Asio

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Geochemical composition of soils provides vital information about their origin and development. Highly weathered soils are widespread in the islands of Leyte and Samar but limited data have been published in terms of their nature, characteristics and nutrient status. This study evaluated the total elemental composition, properties and nutrient status of eight (8) deep and highly weathered soils in various parts of Leyte and Samar. Sampling was done down to 3 to 4 meters deep. Total amounts of Al₂O₃, As₂O₃, CaO, CdO, Cr₂O₃, CuO, Fe₂O₃, K₂O, MgO, MnO, Na₂O, NiO, P₂O₅, PbO, SO₃, SiO₂, TiO₂, ZnO and ZrO₂ were analyzed using an X-ray analytical microscope for eight soil profiles. Most of the deep and highly weathered soils have probably developed from homogenous parent materials based on the regular distribution with depth of TiO₂ and ZrO₂. Two of the soils indicated high variability with depth of TiO₂ and ZrO₂ suggesting that these soils developed from heterogeneous parent material. Most soils have K₂O and CaO values below those of MgO and Na₂O. This suggests more losses of K₂O and CaO have occurred since they are more mobile in the weathering environment. Most of the soils contain low amounts of other elements such as CuO, ZnO, PbO, NiO, CrO and SO₂. Basic elements such as K₂O and CaO are more mobile in the weathering environment than MgO and Na₂O resulting in higher losses of the former than the latter. Other elements also show small amounts in all soil profile. Thus, this study is very useful for sustainable crop production and environmental conservation in the study area specifically for highly weathered soils which are widespread in the Philippines.

Keywords: depth function, geochemical composition, highly weathered soils, total elemental composition

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Authors: Khaled M. Ali, M. A. Abdel-Hamid, Ayman A. Mostafa

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Objective: Safety and efficacy of Ahmed glaucoma valve implantation for the management of uveitis induced glaucoma evaluated on the five dogs with uncontrollable glaucoma. Materials and Methods: Ahmed Glaucoma Valve (AGV®; New World Medical, Rancho Cucamonga, CA, USA) is a flow restrictive, non-obstructive self-regulating valve system. Preoperative ocular evaluation included direct ophthalmoscopy and measurement of the intraocular pressure (IOP). The implant was examined and primed prior to implantation. The selected site of the valve implantation was the superior quadrant between the superior and lateral rectus muscles. A fornix-based incision was made through the conjunectiva and Tenon’s capsule. A pocket is formed by blunt dissection of Tenon’s capsule from the episclera. The body of the implant was inserted into the pocket with the leading edge of the device around 8-10 mm from the limbus. Results: No post operative complications were detected in the operated eyes except a persistent corneal edema occupied the upper half of the cornea in one case. Hyphaema was very mild and seen only in two cases which resolved quickly two days after surgery. Endoscopical evaluation for the operated eyes revealed a normal ocular fundus with clearly visible optic papilla, tapetum and retinal blood vessels. No evidence of hemorrhage, infection, adhesions or retinal abnormalities was detected. Conclusion: Ahmed glaucoma valve is safe and effective implant for treatment of uveitic glaucoma in dogs.

Keywords: Ahmed valve, endoscopy, glaucoma, ocular fundus

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Authors: Hany R. Ammar, Khalil A. Khalil, El-Sayed M. Sherif

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The as-received metal powders were used to synthesis bulk nanocrystalline Al; Al-10%Cu; and Al-10%Cu-5%Ti alloys using mechanical alloying and high frequency induction heat sintering (HFIHS). The current study investigated the influence of milling time and ball-to-powder (BPR) weight ratio on the microstructural constituents and mechanical properties of the processed materials. Powder consolidation was carried out using a high frequency induction heat sintering where the processed metal powders were sintered into a dense and strong bulk material. The sintering conditions applied in this process were as follow: heating rate of 350°C/min; sintering time of 4 minutes; sintering temperature of 400°C; applied pressure of 750 Kgf/cm2 (100 MPa); cooling rate of 400°C/min and the process was carried out under vacuum of 10-3 Torr. The powders and the bulk samples were characterized using XRD and FEGSEM techniques. The mechanical properties were evaluated at various temperatures of 25°C, 100°C, 200°C, 300°C and 400°C to study the thermal stability of the processed alloys. The bulk nanocrystalline Al; Al-10%Cu; and Al-10%Cu-5%Ti alloys displayed extremely high hardness values even at elevated temperatures. The Al-10%Cu-5%Ti alloy displayed the highest hardness values at room and elevated temperatures which are related to the presence of Ti-containing phases such as Al3Ti and AlCu2Ti, these phases are thermally stable and retain the high hardness values at elevated temperatures up to 400ºC.

Keywords: nanocrystalline aluminum alloys, mechanical alloying, hardness, elevated temperatures

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Authors: Jaeun Park, Daekyoung Kim, Ho Kyoon Chung, Heeyeop Chae

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Quantum dots light-emitting diodes (QD-LEDs) have been considered as the next generation display and lighting devices due to their excellent color purity, photo-stability solution process possibility and good device stability. Currently typical quantum dot light emitting diodes contain organic layers such as PEDOT:PSS and PVK for charge transport layers. To make quantum dot light emitting diodes (QD-LED) more stable, it is required to replace those acidic and relatively unstable organic charge transport layers with inorganic materials. Therefore all inorganic and solution processed quantum dot light emitting diodes can potentially be a solution to stable and cost-effective display devices. We studied solution processed NiO films to replace organic charge transport layers that are required for stable all-inorganic based light emitting diodes. The transition metal oxides can be made by various vacuum and solution processes, but the solution processes are considered more cost-effective than vacuum processes. In this work we investigated solution processed NiOx for a hole transport layer (HTL). NiOx, has valence band energy levels of 5.3eV and they are easy to make sol-gel solutions. Water vapor oxidation process was developed and applied to solution processed all-inorganic QD-LED. Turn-on voltage, luminance and current efficiency of QD in this work were 5V, 1800Cd/m2 and 0.5Cd/A, respectively.

Keywords: QD-LED, metal oxide solution, NiO, all-inorganic QD-LED device

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