Search results for: spurious free dynamic range

Authors: Tatsuhiko Aizawa, Hiroshi Morita

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The tool steels such as SKD11 and SKH51 have been utilized as punch and die substrates for cold stamping, forging, and fine blanking processes. The heat-treated SKD11 punches with the hardness of 700 HV wrought well in the stamping of SPCC, normal steel plates, and non-ferrous alloy such as a brass sheet. However, they suffered from severe damage in the fine blanking process of smaller holes than 1.5 mm in diameter. Under the high aspect ratio of punch length to diameter, an elastoplastic bucking of slender punches occurred on the production line. The heat-treated punches had a risk of chipping at their edges. To be free from those damages, the blanking punch must have sufficient rigidity and strength at the same time. In the present paper, the small-hole blanking punch with a dual toughness structure was proposed to provide a solution to this engineering issue in production. The low-temperature plasma nitriding process was utilized to form the nitrogen supersaturated thick layer into the original SKD11 punch. Through the plasma nitriding at 673 K for 14.4 ks, the nitrogen supersaturated layer, with the thickness of 50 μm and without nitride precipitates, was formed as a high nitrogen steel (HNS) layer surrounding the original SKD11 punch. In this two-zone structured SKD11 punch, the surface hardness increased from 700 HV for the heat-treated SKD11 to 1400 HV. This outer high nitrogen SKD11 (HN-SKD11) layer had a homogeneous nitrogen solute depth profile with a nitrogen solute content plateau of 4 mass% till the border between the outer HN-SKD11 layer and the original SKD11 matrix. When stamping the brass sheet with the thickness of 1 mm by using this dually toughened SKD11 punch, the punch life was extended from 500 K shots to 10000 K shots to attain a much more stable production line to yield the brass American snaps. Furthermore, with the aid of the masking technique, the punch side surface layer with the thickness of 50 μm was modified by this high nitrogen super-saturation process to have a stripe structure where the un-nitrided SKD11 and the HN-SKD11 layers were alternatively aligned from the punch head to the punch bottom. This flexible structuring promoted the mechanical integrity of total rigidity and toughness as a punch with an extremely small diameter.

Keywords: high nitrogen supersaturation, semi-dry cold stamping, solid solution hardening, tool steel dies, low temperature nitriding, dual toughness structure, extremely small diameter punch

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Authors: Adya Uluwita, Fernando Pedrosa, Georgi Georgiev, Christian Bernard, Raoul Masterson

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CERN is an international organisation founded by 23 countries that provide the particle physics community with excellence in particle accelerators and other related facilities. Founded in 1954, CERN has a wide range of accelerators that allow groundbreaking science to be conducted. Accelerators bring particles to high levels of energy and make them collide with each other or with fixed targets, creating specific conditions that are of high interest to physicists. A chain of accelerators is used to ramp up the energy of particles and eventually inject them into the largest and most recent one: the Large Hadron Collider (LHC). Among this chain of machines is, for instance the Proton Synchrotron, which was started in 1959 and is still in operation. These machines, called "injectors”, keep evolving over time, as well as the related infrastructure. Massive decommissioning of obsolete cables started in 2015 at CERN in the frame of the so-called "injectors de-cabling project phase 1". Its goal was to replace aging cables and remove unused ones, freeing space for new cables necessary for upgrades and consolidation campaigns. To proceed with the de-cabling, a project co-ordination team was assembled. The start of this project led to the investigation of legacy cables throughout the organisation. The identification of cables stacked over half a century proved to be arduous. Phase 1 of the injectors de-cabling was implemented for 3 years with success after overcoming some difficulties. Phase 2, started 3 years later, focused on improving safety and structure with the introduction of a quality assurance procedure. This paper discusses the implementation of this quality assurance procedure throughout phase 2 of the project and the transition between the two phases. Over hundreds of kilometres of cable were removed in the injectors complex at CERN from 2015 to 2023.

Keywords: CERN, de-cabling, injectors, quality assurance procedure

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Authors: Laura Elena De León Prado, Dora Alicia Cortés Hernández, Javier Sánchez

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Among the different cancer treatments that are currently used, hyperthermia has a promising potential due to the multiple benefits that are obtained by this technique. In general terms, hyperthermia is a method that takes advantage of the sensitivity of cancer cells to heat, in order to damage or destroy them. Within the different ways of supplying heat to cancer cells and achieve their destruction or damage, the use of magnetic nanoparticles has attracted attention due to the capability of these particles to generate heat under the influence of an external magnetic field. In addition, these nanoparticles have a high surface area and sizes similar or even lower than biological entities, which allow their approaching and interaction with a specific region of interest. The most used magnetic nanoparticles for hyperthermia treatment are those based on iron oxides, mainly magnetite and maghemite, due to their biocompatibility, good magnetic properties and chemical stability. However, in order to fulfill more efficiently the requirements that demand the treatment of magnetic hyperthermia, there have been investigations using ferrites that incorporate different metallic ions, such as Mg, Mn, Co, Ca, Ni, Cu, Li, Gd, etc., in their structure. This paper reports the synthesis of nanosized Mg_xMn_1-xFe₂O₄ (x = 0.3 and 0.4) ferrites by sol-gel method and their evaluation in terms of heating capability and in vitro hemolysis to determine the potential use of these nanoparticles as thermoseeds for the treatment of cancer by magnetic hyperthermia. It was possible to obtain ferrites with nanometric sizes, a single crystalline phase with an inverse spinel structure and a behavior near to that of superparamagnetic materials. Additionally, at concentrations of 10 mg of magnetic material per mL of water, it was possible to reach a temperature of approximately 45°C, which is within the range of temperatures used for the treatment of hyperthermia. The results of the in vitro hemolysis assay showed that, at the concentrations tested, these nanoparticles are non-hemolytic, as their percentage of hemolysis is close to zero. Therefore, these materials can be used as thermoseeds for the treatment of cancer by magnetic hyperthermia.

Keywords: ferrites, heating capability, hemolysis, nanoparticles, sol-gel

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Authors: Changyeop Lee, Sewon Kim, Jongho Lee

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Reburning technology has been developed to adopt various commercial combustion systems. Fuel lean reburning is an advanced reburning method to reduce NOx economically without using burnout air, however it is not easy to get high NOx reduction efficiency. In the fuel lean reburning system, the localized fuel rich eddies are used to establish partial fuel rich regions so that the NOx can react with hydrocarbon radical restrictively. In this paper, a new advanced reburning method which supplies reburn fuel with oscillatory motion is introduced to increase NOx reduction rate effectively. To clarify whether forced oscillating injection of reburn fuel can effectively reduce NOx emission, experimental tests were conducted in vertical combustion furnace. Experiments were performed in flames stabilized by a gas burner, which was mounted at the bottom of the furnace. The natural gas is used as both main and reburn fuel and total thermal input is about 40kW. The forced oscillating injection of reburn fuel is realized by electronic solenoid valve, so that fuel rich region and fuel lean region is established alternately. In the fuel rich region, NOx is converted to N2 by reburning reaction, however unburned hydrocarbon and CO is oxidized in fuel lean zone and mixing zone at downstream where slightly fuel lean region is formed by mixing of two regions. This paper reports data on flue gas emissions and temperature distribution in the furnace for a wide range of experimental conditions. All experimental data has been measured at steady state. The NOx reduction rate increases up to 41% by forced oscillating reburn motion. The CO emissions were shown to be kept at very low level. And this paper makes clear that in order to decrease NOx concentration in the exhaust when oscillating reburn fuel injection system is adopted, the control of factors such as frequency and duty ratio is very important.

Keywords: NOx, CO, reburning, pollutant

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Authors: S. Fominow, C. Dobert

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The present article describes the research that deals with the development of equivalent geometric imperfections for the stability design of steel members considering lateral-torsional buckling. The application of these equivalent imperfections takes into account the stiffness-reducing effects due to inelasticity and residual stresses, which lead to a reduction of the load carrying capacity of slender members and structures. This allows the application of a simplified design method, that is performed in three steps. Application of equivalent geometric imperfections, determination of internal forces using geometrical non-linear analysis (GNIA) and verification of the cross-section resistance at the most unfavourable location. All three verification steps are closely related and influence the results. The derivation of the equivalent imperfections was carried out in several steps. First, reference lateral-torsional buckling resistances for various rolled I-sections, slenderness grades, load shapes and steel grades were determined. This was done either with geometric and material non-linear analysis with geometrical imperfections and residual stresses (GMNIA) or for standard cases based on the equivalent member method. With the aim of obtaining identical lateral-torsional buckling resistances as the reference resistances from the application of the design method, the required sizes for equivalent imperfections were derived. For this purpose, a program based on the FEM method has been developed. Based on these results, several proposals for the specification of equivalent geometric imperfections have been developed. These differ in the shape of the applied equivalent geometric imperfection, the model of the cross-sectional resistance and the steel grade. The proposed design methods allow a wide range of applications and a reliable calculation of the lateral-torsional buckling resistances, as comparisons between the calculated resistances and the reference resistances have shown.

Keywords: equivalent geometric imperfections, GMNIA, lateral-torsional buckling, non-linear finite element analysis

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Authors: Isabella Lima Leite de Freitas

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The importance of astronomy for humanity is unquestionable. Despite being a robust science, capable of bringing new discoveries every day and quickly increasing the ability of researchers to understand the universe more deeply, scientific research in this area can also help in various applications outside the domain of astronomy. The objective of this study was to review and conduct a descriptive analysis of published studies that presented the importance of astronomy in the area of education. A narrative review of the literature has been performed, considering the articles published in the last five years. As astronomy involves the study of physics, chemistry, biology, mathematics and technology, one of the studies evaluated presented astronomy as the gateway to science, demonstrating the presence of astronomy in 52 school curricula in 37 countries, with celestial movement the dominant content area. Another intervention study, evaluating individuals aged 4-5 years, demonstrated that the attribution of personal characteristics to cosmic bodies, in addition to the use of comprehensive astronomy concepts, favored the learning of science in preschool-age children, considering the use of practical activities of accompaniment and free drawing. Aiming to measure scientific literacy, another study developed in Turkey, motivated the authorities of this country to change the teaching materials and curriculum of secondary schools after the term “astronomy” appeared as one of the most attractive subjects for young people aged 15 to 24. There are also reports in the literature of the use of pedagogical tools, such as the representation of the Solar System on a human scale, where students can walk along the orbits of the planets while studying the laws of dynamics. The use of this tool favored the teaching of the relationship between distance, duration and speed over the period of the planets, in addition to improving the motivation and well-being of students aged 14-16. An important impact of astronomy on education was demonstrated in the study that evaluated the participation of high school students in the Astronomical Olympiads and the International Astronomy Olympiad. The study concluded that these Olympics have considerable influence on students who pursue a career in teaching or research later on, many of whom are in the area of astronomy itself. In addition, the literature indicates that the teaching of astronomy in the digital age has facilitated the availability of data for researchers, but also for the general population. This fact can increase even more the curiosity that the astronomy area has always instilled in people and promote the dissemination of knowledge on an expanded scale. Currently, astronomy has been considered an important ally in strengthening the school curricula of children, adolescents and young adults. This has been used as teaching tools, in addition to being extremely useful for scientific literacy, being increasingly used in the area of education.

Keywords: astronomy, education area, teaching, review

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Authors: Maimuna Akram, Khadija Zia, Sohaib Naseer

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Pedagogical objectives and the nature of the course content may lead instructors to take varied approaches to selecting a student for the cold call, specifically in a studio setup where students work on different projects independently and show progress work time to time at scheduled critiques. Cold-calling often proves to be an effective tool in eliciting a response without enforcing judgment onto the recipients. While there is a mixed range of behavior exhibited by students who are cold-called, a classification of responses from anxiety-provoking to inspiring may be elicited; there is a need for a greater understanding of utilizing the exchanges in bringing about fruitful and engaging outcomes of studio discussions. This study aims to unravel the dimensions of utilizing the cold-call approach in a didactic exchange within studio pedagogy. A questionnaire survey was conducted in an undergraduate class at Arts and Design School. The impact of cold calling on students’ participation was determined through various parameters, including course choice, participation frequency, students’ comfortability, and teaching methodology. After analyzing the surveys, specific classroom teachers were interviewed to provide a qualitative perspective of the faculty. It was concluded that cold-calling increases students’ participation frequency and also increases preparation for class. Around 67% of students responded that teaching methods play an important role in learning activities and students’ participation during class discussions. 84% of participants agreed that cold calling is an effective way of learning. According to research, cold-calling can be done in large numbers without making students uncomfortable. As a result, the findings of this study support the use of this instructional method to encourage more students to participate in class discussions.

Keywords: active learning, class discussion, class participation, cold calling, pedagogical methods, student engagement

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Authors: Abdul Basit, Shahid Latif, Shah Mehmood

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Lawn fabric was usually prepared from originally of linen but at present chiefly cotton. Lawn fabric is worn in summer. Cotton Lawn is a lightweight pure cloth which is heavier than voile. It is so fine that it is somewhat transparent. It is soft and superb to wear thus it is perfect for summer clothes or for regular wear in hotter climates. Tencel (Lyocell) fiber is considered as the fiber of the future as Tencel fibers are absorbent, soft, and extremely strong when wet or dry, and resistant to wrinkles. Fibers are more absorbent than cotton, softer than silk and cooler than linen. High water absorption and water vapor absorption give more heat capacity and heat balancing effect for thermo-regulation. This thermo-regulation is analogous with the action of phase-change-materials. The thermal wear properties result in cool and dry touch that gives cooling effect in sportswear, and the warmth properties (when used as an insulation layer). These cooling and warming effects are adaptive to the environment giving comfort in a broad range of climatic conditions. In this work, single yarns of Ne 80s were made. Yarns were made from conventional ring spinning. Different yarns of 100% cotton, 100% micro-Tencel and Cotton:micro-Tencel blends (67:33, 50:50:33:67) were made. The mechanical and comfort properties of the woven fabrics were compared. The mechanical properties include the tensile and tear strength, bending length, pilling and abrasion resistance whereas comfort properties include the air permeability, moisture management and thermal resistance. It is found that as the content of the micro-Tencel is increased, the mechanical and comfort properties of the woven fabric are also increased.

Keywords: combed cotton, comfort properties , mechanical properties, micro-Tencel

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Authors: Mohammed Belalia Douma

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Interactive learning is considered as the most effective strategy of learning, it is an educational philosophy based on the learner's contribution and involvement mainly in classroom and how he interacts toward his small society “classroom”, and the level of his collaboration into challenge, discovering, games, participation, all these can be provided through the interactive learning, which aims to activate the learner's role in the operation of learning, which focuses on research and experimentation, and the learner's self-reliance in obtaining information, acquiring skills, and forming values and attitudes. Whereas not based on memorization only, but rather on developing thinking and the ability to solve problems, on teamwork and collaborative learning. With the exchange or roles - teacher to student- , when the student will be more active and performing operations more than the student under the interactive learning method; we might face a several issues dealing with class controlling management, noise, and stability of learning… etc. This research paper is observing the application of the interactive learning on reality “classroom” and answers several assumptions and analyzes the issues coming up of these strategies mainly: noise, class control…etc The research sample was about 150 student of the 3rd year primary school in “Chlef” district, Algeria, level: beginners in the range of age 08 to 10 years old . We provided a questionnaire of confidential fifteen questions and also analyzing the attitudes of learners during three months. it have witnessed as teachers a variety of strategies dealing with applying the interactive learning but with a different issues; time management, noise, uncontrolled classes, overcrowded classes. Finally, it summed up that although the active education is an inevitably effective method of teaching, however, there are drawbacks to this, in addition to the fact that not all theoretical strategies can be applied and we conclude with solutions of this case study.

Keywords: interactive learning, student, learners, strategies.

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Authors: Tahra AlMahmoud, Sameeha Mohamed Al Hadhrami, Mohamed Elhanan, Hanan Naser Alshamsi, Fikri Abu-Zidan

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Background: To the best of the author(s)’ knowledge there are no epidemiological studies for traumatic eye injuries in UAE, neither data on groups at risk or mechanisms for ocular trauma. Purpose: To report the epidemiology of eye injuries that required hospital admission and surgery at a referral center at the eastern part of Abu Dhabi. Method: Retrospective charts review of all patients who had suffered an eye injury that required surgical intervention between 2012 and 2017 at Al Ain Hospital. Demographic data, place of occurrence, the cause of injury, visual acuity (VA) before and after treatment, number of admission days and follow up were extracted. Data were tabulated and presented as number (%), mean (SD), or median (range) as appropriate. Wilcoxon signed rank test was used for VA outcome. Results: One hundred forty-one patients were identified, 96 eyes with open-globe and 48 other types of injuries. The mean age of the patients was 26±15.5 years, and 89% were male. Majority of injuries occurred at the workplace (50.4%) followed by home (31.2%). Trauma with a sharp object (24.1%), blunt object (16.3%), nail (11.3%), and hammer on metal (7.8%) were the most common etiologies of injury. Corneas injuries (48.2%) was the most frequent cause for visual acuity limitation followed by lens/cataract (23.4%). Among the traumatized eyes, 30 eyes (21.3%) retained intraocular foreign body, Mean admission days was 3.16± 2.81days (1-16) and a number of follow up visit was 3.17± 4.11times (0-26). Conclusion: Ocular trauma requiring surgical intervention is an area of concern in particular for occupations involving work with metals. This work may give insight into the value and necessity of implementing preventive measures.

Keywords: epidemiology, Middle Eastern area, occupational injury, ocular traumas

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Authors: Bintou Jobe

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Musculo-skeletal disorders (MSDs) are injuries or disorders of the spine disc, muscle strains, and low back injuries. It remains a major cause of occupational illness. Findings: Due to poor grips during handling, it is possible for neck, shoulder, arm, knees, ankle, fingers, waist, lower back injuries, and other muscle joints to be affected. Pregnant women are more prone to physical and hormonal changes, which lead to the relaxation of supporting ligaments. MSD continues to pose a global concern due to its impact on workers worldwide. The prevalence of the disorder is high, according to research into the workforce in Europe and developing countries. The causes are characterized by long working hours, insufficient rest breaks, poor posture, repetitive motion, poor manual handling techniques, psychological stress, and poor nutrition. To prevent MSD, the design mainly involves avoiding and assessing the risk. However, clinical solutions, policy governance, and minimizing manual labour are also an alternative. In addition, eating a balanced diet and teamwork force are key to elements in minimising the risk. This review aims to raise awareness and promote cost effectiveness prevention and understanding of MSD through research and identify proposed solutions to recognise the underlying causes of MSDs in the construction sectors. The methodology involves a literature review approach, engaging with the policy landscape of MSD, synthesising publications on MSD and a wider range of academic publications. In conclusion, training on effective manual handling techniques should be considered, and Personal Protective Equipment should be a last resort. The implementation of training guidelines has yielded significant benefits.

Keywords: musculoskeletal disorder work related, MSD, manual handling, work hazards

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Authors: Muhammed Saeed Rasheed

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Knowledge of the zinc and phytic acid (PA) concentrations of staple cereal crops are essential when evaluating the nutritional health of national and regional populations. In the present study, a total of 120 farmers’ fields in Iraqi Kurdistan were surveyed for zinc status in soil and wheat grain samples; wheat is the staple carbohydrate source in the region. Soils were analysed for total concentrations of phosphorus (PT) and zinc (ZnT), available P (POlsen) and Zn (ZnDTPA) and for pH. Average values (mg kg-1) ranged between 403-3740 (PT), 42.0-203 (ZnT), 2.13-28.1 (POlsen) and 0.14-5.23 (ZnDTPA); pH was in the range 7.46-8.67. The concentrations of Zn, PA/Zn molar ratio and estimated Zn bioavailability were also determined in wheat grain. The ranges of Zn and PA concentrations (mg kg⁻¹) were 12.3-63.2 and 5400 – 9300, respectively, giving a PA/Zn molar ratio of 15.7-30.6. A trivariate model was used to estimate intake of bioaccessible Zn, employing the following parameter values: (i) maximum Zn absorption = 0.09 (AMAX), (ii) equilibrium dissociation constant of zinc-receptor binding reaction = 0.680 (KP), and (iii) equilibrium dissociation constant of Zn-PA binding reaction = 0.033 (KR). In the model, total daily absorbed Zn (TAZ) (mg d⁻¹) as a function of total daily nutritional PA (mmole d⁻¹) and total daily nutritional Zn (mmole Zn d⁻¹) was estimated assuming an average wheat flour consumption of 300 g day⁻¹ in the region. Consideration of the PA and Zn intake suggest only 21.5±2.9% of grain Zn is bioavailable so that the effective Zn intake from wheat is only 1.84-2.63 mg d-1 for the local population. Overall results suggest available dietary Zn is below recommended levels (11 mg d⁻¹), partly due to low uptake by wheat but also due to the presence of large concentrations of PA in wheat grains. A crop breeding program combined with enhanced agronomic management methods is needed to enhance both Zn uptake and bioavailability in grains of cultivated wheat types.

Keywords: phosphorus, zinc, phytic acid, phytic acid to zinc molar ratio, zinc bioavailability

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Authors: S. Gowri, K. Narayanasamy, R. Krishnamurthy

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Plasma spraying, from the point of value engineering, is considered as a cost-effective technique to deposit high performance ceramic coatings on ferrous substrates for use in the aero,automobile,electronics and semiconductor industries. High-performance ceramics such as Alumina, Zirconia, and titania-based ceramics have become a key part of turbine blades,automotive cylinder liners,microelectronic and semiconductor components due to their ability to insulate and distribute heat. However, as the industries continue to advance, improved methods are needed to increase both the flexibility and speed of ceramic processing in these applications. The ceramics mentioned were individually coated on structural steel substrate with NiCr bond coat of 50-70 micron thickness with the final thickness in the range of 150 to 200 microns. Optimal spray parameters were selected based on bond strength and porosity. The 'optimal' processed specimens were super finished by lapping using diamond and green SiC abrasives. Interesting results could be observed as follows: The green SiC could improve the surface finish of lapped surfaces almost as that by diamond in case of alumina and titania based ceramics but the diamond abrasives could improve the surface finish of PSZ better than that by green SiC. The conventional random scratches could be absent in alumina and titania ceramics but in PS those marks were found to be less. However, the flatness accuracy could be improved unto 60 to 85%. The surface finish and geometrical accuracy were measured and modeled. The abrasives in the midrange of their particle size could improve the surface quality faster and better than the particles of size in low and high ranges. From the experimental investigations after lapping process, the optimal lapping time, abrasive size, lapping pressure etc could be evaluated.

Keywords: atmospheric plasma spraying, ceramics, lapping, surface qulaity, optimization

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Authors: Kyle Burke Pfeiffer, Carmella Burdi, Karen Marsh

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The evacuation and shelter-in-place planning process employed by most jurisdictions within the United States is not informed by a scientifically-derived framework that is inclusive of the behavioral and policy-related indicators of public compliance with evacuation orders. While a significant body of work exists to define these indicators, the research findings have not been well-integrated nor translated into useable planning factors for public safety officials. Additionally, refinement of the planning factors alone is insufficient to support science-based evacuation planning as the behavioral elements of evacuees—even with consideration of policy-related indicators—must be examined in the context of specific regional transportation and shelter networks. To address this problem, the Federal Emergency Management Agency and Argonne National Laboratory developed an agent-based model to support regional analysis of zone-based evacuation in southeastern Georgia. In particular, this model allows public safety officials to analyze the consequences that a range of hazards may have upon a community, assess evacuation and shelter-in-place decisions in the context of specified evacuation and response plans, and predict outcomes based on community compliance with orders and the capacity of the regional (to include extra-jurisdictional) transportation and shelter networks. The intention is to use this model to aid evacuation planning and decision-making. Applications for the model include developing a science-driven risk communication strategy and, ultimately, in the case of evacuation, the shortest possible travel distance and clearance times for evacuees within the regional boundary conditions.

Keywords: agent-based modeling for evacuation, decision-support for evacuation planning, evacuation planning, human behavior in evacuation

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Authors: Michal Biały, Konrad Pietrykowski, Rafal Sochaczewski

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The kinematics and dynamics analysis of crank-piston system of aircraft engine. The object of the study was the high power aircraft engine ASz 62-IR. This engine is produced by a Polish company WSK "PZL-KALISZ" S.A.". All analyzes were performed numerically using CAD and CAE environment. Three-dimensional model of the crank-piston system was developed based on real engine located in the Laboratory of Centre of Innovation and Advanced Technologies of Lublin University of Technology. During the development of the model, the technique of reverse engineering - 3D scanning was used. ASz 62-IR engine is characterized by a radial type of crank-piston system. In this system the cylinders are arranged radially around the circle. This crank-piston system consists of a main connecting rod and eight additional connecting rods. In addition, three-dimensional model consists of a piston pins, pistons and piston rings. As a result of the specific engine design, characteristics of the piston individual movement are slightly different from each other. But the model assumes that they are the same during the analysis. Three-dimensional model of the engine was implemented into the MSC Adams software. The environment of MSC Adams allows for multibody simulation of the dynamic phenomena. This determines the state parameters of the moving elements, among which the load or force distribution on each kinematic node can be distinguished. Materials and characteristic materials parameters were adopted on the basis of commonly used materials for engine parts. The mass values of individual elements were adopted on the basis of real engine parts. The piston gas forces were replaced by calculation of pressure variations recorded during engine tests on the engine test bench. The research the changes of forces acting in the individual kinematic pairs of crank-piston system. The model allows to determine the load on the crankshaft main bearings. This gives the possibility for the main supports forces analysis The model allows for testing and simulation of kinematics and dynamics of a radial aircraft engine. This is the first stage of the work, which aims to numerical simulation of vibration of multi-cylinder aircraft engine. This work has been financed by the Polish National Centre for Research and Development, INNOLOT, under Grant Agreement No. INNOLOT/I/1/NCBR/2013.

Keywords: aircraft engine, CAD, CAE, dynamics, kinematics, MSC Adams, numerical simulation

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Authors: Caiwei Zhu, Remke Klapwijk

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Spatial thinking, a way of thinking based on the understanding and reasoning of spatial concepts and representations, is embedded in science, technology, engineering, arts, and mathematics (STEAM) learning. Aside from many studies that successfully used targeted training to improve students’ spatial thinking skills, few have closely examined how spatial thinking can be trained in classroom settings. Design and technology education, which receives increasing attention towards its integration into formal curriculums, inherently encompasses a wide range of spatial activities, such as constructing mental representations of design ideas, mentally transforming objects and materials to form designs, visually communicating design plans through annotated drawings, and creating 2D and 3D design artifacts. Among different design topics, biomimicry offers a unique avenue for students to recognize and analyze the shapes and structures in nature. By mapping the forms of plants and animals onto functions, students gain inspiration to solve human design challenges. This study is one of the first to highlight opportunities for training spatial thinking in a biomimicry design project for primary school students. Embracing methodological principles of educational design-based research, this case study is conducted along with iterations in the design of the intervention and collaboration with teachers. Data are harvested from small groups of 10- to 12-year-olds at an international school in the Netherlands. Classroom videos, semi-structured interviews with students, design drawings and artifacts, formative assessment, and the pre- and post-intervention spatial test triangulate evidence for students' spatial thinking. In addition to contributing to a theory of integrating spatial thinking in the primary curriculum, mechanisms underlying such improvement in spatial thinking are explored and discussed.

Keywords: biomimicry, design and technology education, primary education, spatial thinking

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Authors: Panwad Wongthong, Thanan Apivantanaporn, Sutthiwan Amattayakul

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Nature-based tourism is one of the fastest growing industries that can bring in economic benefits, improve quality of life and promote conservation of biodiversity and habitats. As tourism develops, substantial socio-economic and environmental costs become more explicit. Particularly in island destinations, the dynamic system and geographical limitations makes the intensity of tourism development and severity of the negative environmental impacts greater. The current contribution of the tourism sector to global climate change is established at approximately 5% of global anthropogenic CO2 emissions. In all scenarios, tourism is anticipated to grow substantially and to account for an increasingly large share of global greenhouse gas emissions. This has prompted an urgent call for more sustainable alternatives. This study selected a small island of Koh Mak in Thailand as a case study because of its reputation of being laid back, family oriented and rich in biodiversity. Importantly, it is a test platform for low carbon tourism development project supported by the Designated Areas for Sustainable Tourism Administration (DASTA) in collaboration with the Institute for Small and Medium Enterprises Development (ISMED). The study explores strategies for low carbon tourism management and assesses challenges and opportunities for Koh Mak to become a low carbon tourism destination. The goal is to identify suitable management approaches applicable for Koh Mak which may then be adapted to other small islands in Thailand and the region. Interventions/initiatives to increase energy efficiency in hotels and resorts; cut carbon emissions; reduce impacts on the environment; and promote conservation will be analyzed. Ways toward long-term sustainability of climate-friendly tourism will be recommended. Recognizing the importance of multi-stakeholder involvement in the tourism sector, findings from this study can reward Koh Mak tourism industry with a triple-win: cost savings and compliance with higher standards/markets; less waste, air emissions and effluents; and better capabilities of change, motivation of business owners, staff, tourists as well as residents. The consideration of climate change issues in the planning and implementation of tourism development is of great significance to protect the tourism sector from negative impacts.

Keywords: climate change, CO2 emissions, low carbon tourism, sustainable tourism management

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Authors: Khushboo Verma

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The use of rape as a weapon of war has been in existence for as early as the middle ages. Women, during the conflict, have been treated as the spoils of war, a reward for the conquering soldiers granted to them by their superiors which is, arguably, most often overlooked as part of the collateral damage that is unavoidable in conflict zones. Korean-born Therese Park’s first novel, A Gift of the Emperor (1997), describes one such atrocious incidence wherein she highlights the active role the Japanese military played in procuring and condoning trafficking of women, who were euphemistically referred to as ‘comfort women’, for prostitution during World War II. This paper thus aims to look at the remembering and reckonings of these women, which fueled a range of creative gestures in the artistic representations and knowledge production by Korean American artists and writers. The essay divides into three parts wherein first it tries to highlight the relationship of the state and the self in relation to the ‘comfort women’ as to who bears the onus of the exploitation of these women, or the responsibility for the redressal with the present-day notions of human rights as studied through Ueno Chizuko’s ‘The Politics of Memory: Nation, Individual and Self’ (1999). There are several narratological elements of the text that are of interest here which shall be viewed and analysed throughout the paper as well. The second part of the paper talks about the aesthetics of rape and sexual violence as represented or (mis)represented by Park in her novel as she attempts to give voice to the victim and retain her and her suffering as the central focus of the narrative. Finally, the third part of the novel explores as well as places the novel in the context of debates over the highly contested issue of ‘comfort women’ and the actual ‘comfort women’ survivors’ testimonies. For this purpose, the present study focuses on Dori Laub’s ‘Truth and Testimony: The Process and the Struggle’ (1991).

Keywords: Korean comfort women, survivors’ testimonies, sexual slavery, aesthetics of sexual violence, horrible memories

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Authors: Akram Khelaifia, Salah Guettala, Nesreddine Djafar Henni, Rachid Chebili

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Reinforced concrete shear walls are pivotal in protecting buildings from seismic forces by providing strength and stiffness. This study highlights the importance of strategically placing shear walls and optimizing the shear wall-to-floor area ratio in building design. Nonlinear analyses were conducted on an eight-story building situated in a high seismic zone, exploring various scenarios of shear wall positioning and ratios to floor area. Employing the performance-based seismic design (PBSD) approach, the study aims to meet acceptance criteria such as inter-story drift ratio and damage levels. The results indicate that concentrating shear walls in the middle of the structure during the design phase yields superior performance compared to peripheral distributions. Utilizing shear walls that fully infill the frame and adopting compound shapes (e.g., Box, U, and L) enhances reliability in terms of inter-story drift. Conversely, the absence of complete shear walls within the frame leads to decreased stiffness and degradation of shorter beams. Increasing the shear wall-to-floor area ratio in building design enhances structural rigidity and reliability regarding inter-story drift, facilitating the attainment of desired performance levels. The study suggests that a shear wall ratio of 1.0% is necessary to meet validation criteria for inter-story drift and structural damage, as exceeding this percentage leads to excessive performance levels, proving uneconomical as structural elements operate near the elastic range.

Keywords: nonlinear analyses, pushover analysis, shear wall, plastic hinge, performance level

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Authors: Udaykumar R., M. S. Ganachari

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In order to engage community pharmacies in Tuberculosis care, a survey has been conducted in Belgaum city, Karnataka state, India. After the survey divided into two groups one is control group and another one is intervention group. One is dispensing of anti-tuberculosis drugs, and another one is non-availability of anti-tuberculosis drugs. Those community pharmacists who are voluntarily interesting for becoming DOTS (Directly observed treatment short course) provider and RNTCP (Revised national tuberculosis control programme) objectives. Structured training is conducted for community pharmacist who are dispensing anti-tuberculosis drugs. The training module includes record maintaining, reporting to the RNTCP, Medication adherence etc. In case of non-availability of anti-tuberculosis drugs, the district RNTCP has been given training for community pharmacist by providing free of drugs to the community pharmacies. So, community pharmacies can dispense anti-tuberculosis drugs to the patients. The target of this study is Private community pharmacies. A simple random sampling method is used and 550 private community pharmacy shops has been involved in Belgaum city of Karnataka state, India. Significance of the Study: This study mainly focused on training of DOTS (Directly observed treatment short course) to the private community pharmacist. Indian Govt. Considers Private Providers as Assets for TB Control and Care to Achieve National Strategic Plan for TB Elimination 2017-2025. The Govt. has not fully tapped the Potential of Private Pharmacies to Fight TB. Providing DOTS as per patient’s convenience through community DOT Providers with periodic monitoring may reduce the treatment Default. We explore RNTCP objectives interventions that can have directly managed by private community pharmacy shop. Objectives: Survey of anti-tuberculosis drugs in Community pharmacy shop in Belgaum city. Interested community pharmacist who are willing to become DOTS (Directly observed treatment short course) Provider. Major Findings:Most of the community pharmacist are dispensing anti-tuberculosis drugs without having knowledge of DOTS therapy and RNTCP objectives. No community pharmacist is aware of RNTCP and Tuberculosis burden in India. Most of the Pharmacist agreed to come for RNTCP Training module for the community pharmacist. Some of the community pharmacist not dispensing anti-tuberculosis drugs and they agreed to become official DOTS provider. Concluding Statement: Awareness of role of community pharmacist on tuberculosis control and care has been neglected. More than 50% of tuberculosis patients seeking treatments from privatesector. In this study finds the major gap between government and private sector on tuberculosis treatment.

Keywords: community pharmacist, directly observed treatment short course(DOTS), revised national tuberculosis control programme (RNTCP), private pharmacies, anti-tuberculosis drugs

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Authors: Reshma P. Nuri, Ebenezer Dassah

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Introduction: Raising a child with a disability can affect family members in different ways. However, this can be determined by the way in which a family member copes with the situation. There is little research that explores how families develop coping strategies to overcome barriers in raising CWDs. Objective: This study explored family members’ coping mechanism in raising a child with disability in Bangladesh. Method: A qualitative approach that involved 20 interviews with family members of CWDs. A purposive sampling procedure was used in selecting the study participants. A digital recorder was used to record all the interviews. Transcriptions were done in Bengali, translated into English, and then imported to NVivo software 12 for analysis. Thematic analysis was used to analyze the data. Results: The study revealed that family members adopted different coping strategies for their CWDs, including seeking support from formal (e.g., service providers) and informal sources (family members and friends); relying on religious beliefs; accepting the situation. Additionally, to cope with extra cost in raising CWDs, family members strategies included relying on overtime work; borrowing money from financial institutions; selling or mortgaging assets; and replying on donations from community members. Finally, some families had to reduce spending on food and buying toys for their CWDs. Conclusion: This qualitative study highlighted a range of coping mechanism adopted by family members in Bangladesh. The information provided in this study is potentially important to policy makers and service providers as it presents evidence on the coping mechanism of families in raising their CWDs. This underscores the need for policy design and service delivery in government support system in Bangladesh and potentially in other low- and middle-income contexts.

Keywords: Bangladesh, children with disabilities, coping mechanism, family members

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Authors: Kurudzirayi Robson Musikavanhu

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Nanophase particles exhibit quantum behavior by virtue of their small size, being particles of gamma to x-ray wavelength [atomic range]. Such particles exhibit high frequencies, high energy/photon, high penetration power, high ionization power [atomic behavior] and are stable at low energy levels as opposed to bulk phase matter [macro particles] which exhibit higher wavelength [radio wave end] properties, hence lower frequency, lower energy/photon, lower penetration power, lower ionizing power and are less stable at low temperatures. The ‘unique’ behavioral motion of Nano systems will remain a mystery as long as quantum theory remains a mystery, and for pharmacology, pharmacovigilance profiling of Nano systems becomes virtually impossible. Quantum theory is the 4 – 3 – 5 electromagnetic law of life and life motion systems on planet earth. Electromagnetic [wave-particle] properties of all particulate matter changes as mass [bulkiness] changes from one phase to the next [Nano-phase to micro-phase to milli-phase to meter-phase to kilometer phase etc.] and the subsequent electromagnetic effect of one phase particle on bulk matter [different phase] changes from one phase to another. All matter exhibit electromagnetic properties [wave-particle duality] in behavior and the lower the wavelength [and the lesser the bulkiness] the higher the gamma ray end properties exhibited and the higher the wavelength [and the greater the bulkiness], the more the radio-wave end properties are exhibited. Quantum theory is the 4 [moon] – 3[sun] – [earth] 5 law of the Electromagnetic spectrum [solar system]. 4 + 3 = 7; 4 + 3 + 5 = 12; 4 * 3 * 5 = 60; 42 + 32 = 52; 43 + 33 + 53 = 63. Quantum age is overdue.

Keywords: electromagnetic solar system, nano-material, nano pharmacology, pharmacovigilance, quantum theory

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Authors: Montasser Mohamed Abdelwahab Mahmoud, Abdelwahab Saber Esawi

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The language of the Qur’an has a wide range of understanding, reflection, and meanings. Therefore, translation of the Qur’an is inevitably nothing but a translation of the interpretation of the meanings of the Qur’an. It requires special competencies and skills for translators so that they can get close to the intended meaning of the verse of the Qur’an and convey it with precision. In the Arabic language, the verbal noun “AlMasdar” is a very important derivative that properly expresses the verbal idea in the form of a noun. It sounds the same as the base form of the verb with minor changes in the vowel pattern. It is one of the important topics in morphology. The morphologists divided verbal nouns into auditory and analogical, and they stated that that the verbal nouns (Masadars) originating from three-letter verbs are auditory, although they set controls for some of them in order to preserve them. As for the lexicographers, they mentioned the verbal nouns while talking about the lexical materials, and in some cases, their explanation of them exceeded that made by the morphologists, especially in their discussion of structures that the morphologists did not refer to in their books. The verb kafara (disbelief), for example, has three patterns, namely: al-kufْr, al-kufrān, and al-kufūr, and it was mentioned in the Holy Qur’an with different connotations. The verb ṣāma (fasted) with his two patterns (al-ṣaūm and al-ṣīām) was mentioned in the Holy Qur’an while their semantic meaning is different. The problem discussed in this research paper lied in the "linguistic loss" committed by translators when dealing with Islamic religious texts, especially the Qur'an. The study tried to identify the strategy adopted by translators of the Holy Qur'an in translating words that were classified as verbal nouns through analyzing the translation rendered by five translations of the Qur’an into English: Yusuf Ali, Pickthall, Mohsin Khan, Muhammad Sarwar, and Shakir. This study was limited to the verbal nouns in the Quraan that originate from three-letter verbs and have different semantic meanings.

Keywords: pattern, three-letter verbs, translation of the Quran, verbal nouns

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Authors: M. Aboalazayem, Essam A. Gouda, Ahmed M. Moussa, Amr E. Flifl

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Field data collecting is considered one of the most difficult work due to the difficulty of accessing large zones such as large lakes. Also, it is well known that the cost of obtaining field data is very expensive. Remotely monitoring of lake water quality (WQ) provides an economically feasible approach comparing to field data collection. Researchers have shown that lake WQ can be properly monitored via Remote sensing (RS) analyses. Using satellite images as a method of WQ detection provides a realistic technique to measure quality parameters across huge areas. Landsat (LS) data provides full free access to often occurring and repeating satellite photos. This enables researchers to undertake large-scale temporal comparisons of parameters related to lake WQ. Satellite measurements have been extensively utilized to develop algorithms for predicting critical water quality parameters (WQPs). The goal of this paper is to use RS to derive WQ indicators in Aswan High Dam Reservoir (AHDR), which is considered Egypt's primary and strategic reservoir of freshwater. This study focuses on using Landsat8 (L-8) band surface reflectance (SR) observations to predict water-quality characteristics which are limited to Turbidity (TUR), total suspended solids (TSS), and chlorophyll-a (Chl-a). ArcGIS pro is used to retrieve L-8 SR data for the study region. Multiple linear regression analysis was used to derive new correlations between observed optical water-quality indicators in April and L-8 SR which were atmospherically corrected by values of various bands, band ratios, and or combinations. Field measurements taken in the month of May were used to validate WQP obtained from SR data of L-8 Operational Land Imager (OLI) satellite. The findings demonstrate a strong correlation between indicators of WQ and L-8 .For TUR, the best validation correlation with OLI SR bands blue, green, and red, were derived with high values of Coefficient of correlation (R2) and Root Mean Square Error (RMSE) equal 0.96 and 3.1 NTU, respectively. For TSS, Two equations were strongly correlated and verified with band ratios and combinations. A logarithm of the ratio of blue and green SR was determined to be the best performing model with values of R2 and RMSE equal to 0.9861 and 1.84 mg/l, respectively. For Chl-a, eight methods were presented for calculating its value within the study area. A mix of blue, red, shortwave infrared 1(SWR1) and panchromatic SR yielded the greatest validation results with values of R2 and RMSE equal 0.98 and 1.4 mg/l, respectively.

Keywords: remote sensing, landsat 8, nasser lake, water quality

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Authors: Ishani Maheshika

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The intermediary role performed by freight forwarders in exportation has become significant in fulfilling businesses’ supply chain needs in this dynamic world. Since the success of exporter’s business is at present, highly reliant on supply chain optimization, cost efficiency, profitability, consistent service and responsiveness, the decision of selecting the most beneficial freight forwarder has become crucial for exporters. Although there are similar foreign researches, prior researches covering Sri Lankan setting are not in existence. Moreover, results vary with time, nature of industry and business environment factors. Therefore, a study from the perspective of Sri Lankan exporters was identified as a requisite to be researched. In order to identify and prioritize key factors which have affected the exporter’s decision in selecting freight forwarders in Sri Lankan context, Sri Lankan export industry was stratified into 22 sectors based on commodity using stratified sampling technique. One exporter from each sector was then selected using judgmental sampling to have a sample of 22. Factors which were identified through a pilot survey, was organized under 6 main criteria. A questionnaire was basically developed as pairwise comparisons using 9-point semantic differential scale and comparisons were done within main criteria and subcriteria. After a pre-testing, interviews and e-mail questionnaire survey were conducted. Data were analyzed using Analytic Hierarchy Process to determine priority vectors of criteria. Customer service was found to be the most important main criterion for Sri Lankan exporters. It was followed by reliability and operational efficiency respectively. The criterion of the least importance is company background and reputation. Whereas small sized exporters pay more attention to rate, reliability is the major concern among medium and large scale exporters. Irrespective of seniority of the exporter, reliability is given the prominence. Responsiveness is the most important sub criterion among Sri Lankan exporters. Consistency of judgments with respect to main criteria was verified through consistency ratio, which was less than 10%. Being more competitive, freight forwarders should come up with customized marketing strategies based on each target group’s requirements and expectations in offering services to retain existing exporters and attract new exporters.

Keywords: analytic hierarchy process, freight forwarders, main criteria, Sri Lankan exporters, subcriteria

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Authors: Surya Prasad Sharma, Suyash Katdare, Syed Ainul Hussain

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Human-induced factors contributed to the population decline of crocodylians in India which became evident by the mid-20th century when authorities forewarned the extinction risk for the crocodile and proposed regulation in the crocodile trade. The proposed action led to the enactment of national and international wildlife regulations to prohibit the trade-in of crocodile skins and parts. Subsequently, conservation translocation programs were initiated to restore the species in the wild through a 'head-start' approach. In India, the crocodile conservation program, which began in the early 1970s, has been one of India's longest-running conservation initiatives. The gharial (Gavialis gangeticus) population has benefitted, and the gharial number increased rapidly owing to these efforts. The immediate risk of extinction was averted as the gharial has recovered due to decades-long cumulative conservation efforts, the consideration of the genetic for monitoring the recovery of the recovered populations is still lacking. Hence, we assessed the genetic diversity of the Girwa gharial population in India using six polymorphic nuclear microsatellites loci and mitochondrial control region. The number of alleles per loci ranged between 2 to 5, and the allelic richness (Ar) was 2.67 ± 0.49, and the observed (Ho) and expected (He) heterozygosities were 0.42 ± 0.08 and 0.42 ± 0.09, respectively. The M-ratio yielded a value of (0.41 ± 0.16) lower than critical M, suggesting a genetic bottleneck in the Girwa population. We observed more mitochondrial control region haplotypes in the Girwa population than previously reported in the largest gharial population in the Chambal River. Overall, our study indicates that genetic diversity remains low despite the recovery in the Girwa population. Hence, we recommend a range-wide genetic assessment of gharial populations using high-throughput techniques to identify the source population and plan future translocation programs.

Keywords: conservation translocation, recovery, crocodile, bottleneck

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Authors: Amal G. Kurian

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The use of mathematical modeling has seen a considerable boost in recent times with the development of many advanced algorithms and mathematical modeling capabilities. The advantages this method has over other methods are that they are much closer to standard physics theories and thus represent a better theoretical model. They take lesser solving time and have the ability to change various parameters for optimization, which is a big advantage, especially in automotive industry. This thesis work focuses on a thorough investigation of the effects of vehicle speed and road roughness on a heavy commercial vehicle ride and structural dynamic responses. Since commercial vehicles are kept in operation continuously for longer periods of time, it is important to study effects of various physical conditions on the vehicle and its user. For this purpose, various experimental as well as simulation methodologies, are adopted ranging from experimental transfer path analysis to various road scenario simulations. To effectively investigate and eliminate several causes of unwanted responses, an efficient and robust technique is needed. Carrying forward this motivation, the present work focuses on the development of a mathematical model of a 4-axle configuration heavy commercial vehicle (HCV) capable of calculating responses of the vehicle on different road PSD inputs and vehicle speeds. Outputs from the model will include response transfer functions and PSDs and wheel forces experienced. A MATLAB code will be developed to implement the objectives in a robust and flexible manner which can be exploited further in a study of responses due to various suspension parameters, loading conditions as well as vehicle dimensions. The thesis work resulted in quantifying the effect of various physical conditions on ride comfort of the vehicle. An increase in discomfort is seen with velocity increase; also the effect of road profiles has a considerable effect on comfort of the driver. Details of dominant modes at each frequency are analysed and mentioned in work. The reduction in ride height or deflection of tire and suspension with loading along with load on each axle is analysed and it is seen that the front axle supports a greater portion of vehicle weight while more of payload weight comes on fourth and third axles. The deflection of the vehicle is seen to be well inside acceptable limits.

Keywords: mathematical modeling, HCV, suspension, ride analysis

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Authors: Hanjun Hu, Jinxiang Zhang

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With the decline of "growthism", China's urbanization process has shifted from the stage of spatial expansion to the stage of optimization of built-up spaces, and urban renewal has gradually become a new wave of China's urban movement in recent years. The ongoing urban renewal movement in China not only needs to generate new motivation for urban development but also solve the backlog of social problems caused by rapid urbanization, which provides an opportunity for the transformation of China's urban governance model. Unlike previous approaches that focused on physical space and functional renewal, such as urban reconstruction, redevelopment, and reuse, the key challenge of urban renewal in the post-growth era lies in coordinating the complex interest relationships between multiple stakeholders. The traditional theoretical frameworks that focus on the structural relations between social groups are insufficient to explain the behavior logic and mutual cooperation mechanism of various groups and individuals in the current urban renewal practices. Therefore, based on the long-term tracking of the urban renewal practices in the Old City of Nanjing (OCN), this paper introduces the "collective action" theory to deeply analyze changes in the urban renewal governance model in OCN and tries to summarize the governance strategies that promote the formation of collective action within recent practices from a micro-scale. The study found that the practice in OCN experienced three different stages "government-led", "growth coalition" and "asymmetric game". With the transformation of government governance concepts, the rise of residents' consciousness of rights, and the wider participation of social organizations in recent years, the urban renewal in OCN is entering a new stage of "collective renewal action". Through the establishment of the renewal organization model, incentive policies, and dynamic negotiation mechanism, urban renewal in OCN not only achieves a relative balance between individual interests and collective interests but also makes the willingness of residents the dominant factor in formulating urban renewal policies. However, the presentation of "collective renewal action" in OCN is still mainly based on typical cases. Although the government is no longer the dominant role, a large number of resident-led collective actions have not yet emerged, which puts forward new research needs for a sustainable governance policy innovation in this action.

Keywords: urban renewal, collective action theory, governance, cooperation mechanism, China

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Authors: Md. Kausar Alam, Ramin Motamed

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The damaging effects of liquefaction-induced ground movements have been frequently observed in past earthquakes, such as the 2010-2011 Canterbury Earthquake Sequence (CES) in New Zealand and the 2011 Tohoku earthquake in Japan. To reduce the consequences of soil liquefaction at shallow depths, various ground improvement techniques have been utilized in engineering practice, among which this research is focused on experimentally evaluating the press-in sheet piling technique. The press-in sheet pile technique eliminates the vibration, hammering, and noise pollution associated with dynamic sheet pile installation methods. Unfortunately, there are limited experimental studies on the press-in sheet piling technique for liquefaction mitigation using 1g shake table tests in which all the controlling mechanisms of liquefaction-induced foundation settlement, including sand ejecta, can be realistically reproduced. In this study, a series of moderate scale 1g shake table experiments were conducted at the University of Nevada, Reno, to evaluate the performance of this technique in liquefiable soil layers. First, a 1/5 size model was developed based on a recent UC San Diego shaking table experiment. The scaled model has a density of 50% for the top crust, 40% for the intermediate liquefiable layer, and 85% for the bottom dense layer. Second, a shallow foundation is seated atop an unsaturated sandy soil crust. Third, in a series of tests, a sheet pile with variable embedment depth is inserted into the liquefiable soil using the press-in technique surrounding the shallow foundations. The scaled models are subjected to harmonic input motions with amplitude and dominant frequency properly scaled based on the large-scale shake table test. This study assesses the performance of the press-in sheet piling technique in terms of reductions in the foundation movements (settlement and tilt) and generated excess pore water pressures. In addition, this paper discusses the cost-effectiveness and carbon footprint features of the studied mitigation measures.

Keywords: excess pore water pressure, foundation settlement, press-in sheet pile, soil liquefaction

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Authors: Nagui A. Abdel-Khalek, Khaled A. Selim, Ahmed Hamdy

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Kaolin is naturally occurring ore predominantly containing kaolinite mineral in addition to some gangue minerals. Typical impurities present in kaolin ore are quartz, iron oxides, titanoferrous minerals, mica, feldspar, organic matter, etc. The main coloring impurity, particularly in the ultrafine size range, is titanoferrous minerals. Kaolin is used in many industrial applications such as sanitary ware, table ware, ceramic, paint, and paper industries, each of which should be of certain specifications. For most industrial applications, kaolin should be processed to obtain refined clay so as to match with standard specifications. For example, kaolin used in paper and paint industries need to be of high brightness and low yellowness. Egyptian kaolin is not subjected to any beneficiation process and the Egyptian companies apply selective mining followed by, in some localities, crushing and size reduction only. Such low quality kaolin can be used in refractory and pottery production but not in white ware and paper industries. This paper aims to study the amenability of beneficiation of an Egyptian kaolin ore of El-Teih locality, Sinai, to be suitable for different industrial applications. Attrition scrubbing and classification followed by magnetic separation are applied to remove the associated impurities. Attrition scrubbing and classification are used to separate the coarse silica and feldspars. Wet high intensity magnetic separation was applied to remove colored contaminants such as iron oxide and titanium oxide. Different variables affecting of magnetic separation process such as solid percent, magnetic field, matrix loading capacity, and retention time are studied. The results indicated that substantial decrease in iron oxide (from 1.69% to 0.61% ) and TiO2 (from 3.1% to 0.83%) contents as well as improving iso-brightness (from 63.76% to 75.21% and whiteness (from 79.85% to 86.72%) of the product can be achieved.

Keywords: Kaolin, titanoferrous minerals, beneficiation, magnetic separation, attrition scrubbing, classification

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