Search results for: Indo-Pak tension

Authors: Xiaoxiao Zhao

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We report macroscopic evidence of the liquidlike nature of surface-tethered poly(dimethylsiloxane) (PDMS) brushes by studying their adhesion to ice. Whereas ice permanently detaches from solid surfaces when subjected to sufficient shear, commonly referred to as the material’s ice adhesion strength, adhered ice instead slides over PDMS brushes indefinitely. When additionally methylated, we observe a Couette-like flow of the PDMS brushes between the ice and silicon surface. PDMS brush ice adhesion displays shear-rate-dependent shear stress and rheological behavior reminiscent of liquids and is affected by ice velocity, temperature, and brush thickness, following scaling laws akin to liquid PDMS films. This liquidlike nature allows it to detach solely by self-weight, yielding an ice adhesion strength of 0.3 kPa, 1000 times less than low surface energy, perfluorinated monolayer. The methylated PDMS brushes also display omniphobicity, repelling all liquids essentially with vanishingly small contact angle hysteresis. Methylation results in significantly higher contact angles than previously reported, nonmethylated brushes, especially for polar liquids of both high and low surface tension.

Keywords: omniphobic, surface science, polymer brush, icephobic surface

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Authors: Luljeta Plakolli-Kasumi

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In the digital age, the relationship between traditional property rights and online intellectual property rights is becoming increasingly complex. On the one hand, the internet and advancements in technology have allowed for the widespread distribution and use of digital content, making it easier for individuals and businesses to access and share information. On the other hand, the rise of digital piracy and illegal file-sharing has led to increased concerns about the protection of intellectual property rights. This paper aims to examine the relationship between traditional property rights and online intellectual property rights in the digital age by analyzing the current legal frameworks, key challenges and controversies that arise, and potential solutions for addressing these issues. The paper will look at how traditional property rights concepts such as ownership and possession are being applied in the online context and how they intersect with new and evolving forms of intellectual property such as digital downloads, streaming services, and online content creation. It will also discuss the tension between the need for strong intellectual property protection to encourage creativity and innovation and the public interest in promoting access to information and knowledge. Ultimately, the paper will explore how the legal system can adapt to better balance the interests of property owners, creators, and users in the digital age.

Keywords: intellectual property, traditional property, digital age, digital content

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Authors: A. U. Haque, W. Asrar, A. A Omar, E. Sulaeman, J. S. M. Ali

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Buoyancy force applied on deformable symmetric bodies can be estimated by using Archimedes Principle. Such bodies like ellipsoidal bodies have high volume to surface ratio and are isometrically scaled for mass, length, area and volume to follow square cube law. For scaling up such bodies, it is worthwhile to find out the scaling relationship between the other physical quantities that represent thermodynamic, structural and inertial response etc. So, dimensionless similarities to find an allometric scale can be developed by using Bukingham π theorem which utilizes physical dimensions of important parameters. Base on this fact, physical dependencies of buoyancy system are reviewed to find the set of physical variables for deformable bodies of revolution filled with expandable gas like helium. Due to change in atmospheric conditions, this gas changes its volume and this change can effect the stability of elongated bodies on the ground as well as in te air. Special emphasis was given on the existing similarity parameters which can be used in the design of experiments of such bodies whose shape is affected by the external force like a drag, surface tension and kinetic loads acting on the surface. All these similarity criteria are based on non-dimensionalization, which also needs to be consider for scaling up such bodies.

Keywords: Bukhigham pi theorem, similitude, scaling, buoyancy

Procedia PDF Downloads 349

Authors: Yesim Ozogul, Mustafa Durmuş, Fatih Ozogul, Esmeray Kuley Boğa, Yılmaz Uçar, Hatice Yazgan

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The effects of oil-in-water nanoemulsions on the sensory, chemical (total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), peroxide value (PV) and free fatty acids (FFA), and microbiological qualities (total viable count (TVC), total psychrophilic bacteria, and total Enterbactericaea bacteria) of sea bream fillets stored at 2 ± 2°C were investigated. Physical properties of emulsions (viscosity, the particle size of droplet, thermodynamic stability, refractive index and surface tension) were determined. The results showed that the use of nanoemulsion extended the shelf life of fish 2 days when compared with the control. Treatment with nanoemulsions significantly (p<0.05) decreased the values of biochemical parameters during storage period. Bacterial growth was inhibited by the use of nanoemulsions. Based on the results, it can be concluded that nanoemulsions based on commercial oils extended the shelf life and improved the quality of sea bass fillets during storage period.

Keywords: lipid oxidation, nanoemulsion, sea bass, quality parameters

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Authors: Ekaterina Leusheva, Valentin Morenov

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Well drilling in hard rocks is coupled with high energy demands which negates the speed of the process and thus reduces overall effectiveness. Aim of this project is to develop the technique of experimental research, which would allow to select optimal washing fluid composition while adding special hardness reducing detergent reagents. Based on the analysis of existing references and conducted experiments, technique dealing with quantitative evaluation of washing fluid weakening influence on drilled rocks was developed, which considers laboratory determination of three mud properties (density, surface tension, specific electrical resistance) and three rock properties (ultimate stress, dynamic strength, micro-hardness). Developed technique can be used in the well drilling technologies and particularly while creating new compositions of drilling muds for increased destruction effectiveness of hard rocks. It can be concluded that given technique introduces coefficient of hard rocks destruction effectiveness that allows quantitative evaluation of different drilling muds on the drilling process to be taken. Correct choice of drilling mud composition with hardness reducing detergent reagents will increase drilling penetration rate and drill meterage per bit.

Keywords: detergent reagents, drilling mud, drilling process stimulation, hard rocks

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Authors: Benaouda Hemza

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This work on the characterization of structural elements in metal fiber concrete is devoted to the study of recyclability, as reinforcement for concrete, of chips resulting from the machining of steel parts. We are interested in this study to the rheological behavior of fresh chips reinforced concrete and its mechanical behavior at a young age. The evaluation of the workability with the LCL workabilimeter shows that optimal sand gravel ratios (S/G) are S/G=0.8, and S/G=1. The study of the content chips (W%) influence on the workability of the concrete shows that the flow time and the S/G optimum increase with W%. For S/G=1.4, the flow time is practically insensitive to the variation of W%, the concrete behavior is similar to that of self-compacting concrete. Mechanical characterization tests (direct tension, compression, bending, and splitting) show that the mechanical properties of chips concrete are comparable to those of the two selected reference concretes (concrete reinforced with conventional fibers: EUROSTEEL fibers corrugated and DRAMIX fibers). Chips provide a significant increase in strength and some ductility in the post-failure behavior of the concrete. Recycling chips as reinforcement for concrete can be favorably considered.

Keywords: fiber concrete, chips, workability, direct tensile test, compression test, bending test, splitting test

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Authors: Ammari Abdelhammid

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This work on the characterization of structural elements in metal fiber concrete is devoted to the study of recyclability, as reinforcement for concrete, of chips resulting from the machining of steel parts. We're interested in this study to the Rheological behavior of fresh chips reinforced concrete and its mechanical behavior at a young age. The evaluation of the workability with the LCL workabilimeter shows that optimal sand gravel ratios ( S/G) are S/G = 0.8 and S/G = 1. The study of the content chips (W%) influence on the workability of the concrete shows that the flow time and the S/G optimum increase with W%. For S/G = 1.4, the flow time is practically insensitive to the variation of W%, the concrete behavior is similar to that of self-compacting concrete. Mechanical characterization tests (direct tension, compression, bending, and splitting) show that the mechanical properties of chips concrete are comparable to those of the two selected reference concretes (concrete reinforced with conventional fibers: Eurosteel fibers corrugated and Dramix fibers). Chips provide a significant increase in strength and some ductility in the post-failure behavior of the concrete. Recycling chips as reinforcement for concrete can be favorably considered.

Keywords: fiber concrete, chips, workability, direct tensile test, compression test, bending test, splitting test

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Authors: Rudy Djamaluddin, Arbain Tata, Rita Irmawaty

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The study conducted a simulation of the effect of sea water to the bonding capacity of GFRP sheet on the concrete beams using a simulation tank. As it well known that, fiber reinforced polymer (FRP) has been applied to many purposes for civil engineering structures not only for new structures but also for strengthening of the deteriorated structures. The FRP has advantages such as its corrosion resistance, as well as high tensile strength, to weight ratio. Glass composed FRP (GFRP) sheet is most commonly used due to its relatively lower cost compared to the other FRP materials. GFRP sheet is applied externally by bonding it on the concrete surface. Many studies have been done to investigate the bonding of GFRP sheet. However, it is still very rarely studies on the effect of sea water to the bonding capacity of GFRP sheet on the strengthened beams due to flexural loadings. This is important to be clarified for the wider application of GFRP sheet especially on the flexural structure that directly contact to the sea environment. To achieve the objective of the study, a series of concrete beams strengthened with GFRP sheet on extreme tension surface were prepared. The beams then were stored on the sea water tank for six months. Results indicated the bonding capacity decreased after six months exposed to the sea water.

Keywords: GFRP sheet, sea water, concrete beams, bonding

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Authors: Saidia Houari

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The current coronavirus pandemic (COVID-19) is a special and unusual reality. It can affect people physically, but also psychologically. Indeed, in such a context, many people will experience reactions of stress, anxiety and depression, and Sports is known to be a great in improving the effectiveness of the nervous system and mental health. Professor Ango Frubuze“many studies proved that sports play an important role in fighting psychological tension and some other psychological problems, such as depression and sleep difficulties, but on condition of practicing them properly,choosing the kind that generates comfort and happiness for man “ .The sports university professor in the German city of Cologne added that the effort exerted during the exercise works on restoring balance to the stress hormones like cortisol.The case report provides an insight into the COVID-19 current situation and represents a picture of the current state of mental health and an overview of novel coronavirus (Covid-19) outbreaks in some countries of the world. Some procedures taken to combat the coronavirus. We proposed the practice of physical activities during the quarantine period, and we showed their importance and their positive effects.

Keywords: COVID-19, psycholiqical impacts, stress, physical activities

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Authors: Emily Simone Doffing, Danielle Kohfeldt

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Disabled students are underrepresented in graduate-level degree enrollment and completion. There is limited research on disabled students' progression during the pandemic. Disabled graduate students (DGS) face unique interpersonal and institutional barriers, yet, limited research explores these barriers, buffering facilitators, and aids to academic persistence. This study adopts an asset-based, embodied disability approach using the critical pedagogy theoretical framework instead of the deficit research approach. The Participatory Action Research (PAR) paradigm, the critical pedagogy theoretical framework, and emancipatory disability research share the same purpose -creating a socially just world through reciprocal learning. This study is one of few, if not the first, to center solely on DGS’ lived understanding using a Participatory Action Research (PAR) epistemology. With a PAR paradigm, participants and investigators work as a research team democratically at every stage of the research process. PAR has individual and systemic outcomes. PAR lessens the researcher-participant power gap and elevates a marginalized community’s knowledge as expertise for local change. PAR and critical pedagogy work toward enriching everyone involved with empowerment, civic engagement, knowledge proliferation, socio-cultural reflection, skills development, and active meaning-making. The PAR process unveils the tensions between disability and graduate school in policy and practice during the pandemic. Likewise, institutional and ideological tensions influence the PAR process. This project is recruiting 10 DGS until September through purposive and snowball sampling. DGS will collectively practice praxis during four monthly focus groups in the fall 2023 semester. Participant researchers can attend a focus group or an interview, both with field notes. September will be our orientation and first monthly meeting. It will include access needs check-ins, ice breakers, consent form review, a group agreement, PAR introduction, research ethics discussion, research goals, and potential research topics. October and November will be available for meetings for dialogues about lived experiences during our collaborative data collection. Our sessions can be semi-structured with “framing questions,” which would be revised together. Field notes include observations that cannot be captured through audio. December will focus on local social action planning and dissemination. Finally, in January, there will be a post-study focus group for students' reflections on their experiences of PAR. Iterative analysis methods include transcribed audio, reflexivity, memos, thematic coding, analytic triangulation, and member checking. This research follows qualitative rigor and quality criteria: credibility, transferability, confirmability, and psychopolitical validity. Results include potential tension points, social action, individual outcomes, and recommendations for conducting PAR. Tension points have three components: dubious practices, contestable knowledge, and conflict. The dissemination of PAR recommendations will aid and encourage researchers to conduct future PAR projects with the disabled community. Identified stakeholders will be informed of DGS’ insider knowledge to drive social sustainability.

Keywords: participatory action research, graduate school, disability, higher education

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Authors: Debby Rizqie Amelia Gustin, Purnomo Yusgiantoro

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Hydrocarbon energy is still pivotal to today’s economy, but its existence is continually declining. Thus, preserving future energy supply has become the national interest of many countries, which they cater in various way, from importing to expansion and occupation. Underwater of Natuna islands in Indonesia deposits great amount of natural gas reserved, numbered to 46 TCF (trillion cubic feet), which is highly potential to meet Indonesia future energy demand. On the other hand, there could be a possibility that others also seek this natural resources. Natuna is located in the borderline of Indonesia, directly adjacent to the South China Sea, an area which is prolonged to conflict. It is a challenge for Indonesia government to preserve their energy deposit in Natuna islands and to response accordingly if the tension in South China Sea rises. This paper examines that nowadays defense and border security is not only a matter of guarding a country from foreign invasion, but also securing its resources accumulated on the borderline. Countries with great amount of energy deposits on their borderline need to build up their defense capacity continually, to ensure their territory along with their energy deposits is free from any interferences.

Keywords: border security, defense, energy, national interest, threat

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Authors: Bambang Piscesa, Mario M. Attard, Dwi Presetya, Ali K. Samani

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A numerical strategy formulated using a plasticity approach is presented to model spalling of the concrete cover in reinforced concrete columns. The stage at which the concrete cover within reinforced concrete column spalls has a direct bearing on the load capacity. The concrete cover can prematurely spall before the full cross-section can be utilized if the concrete is very brittle under compression such as for very high strength concretes. If the confinement to the core is high enough, the column can achieve a higher peak load by utilizing the core. A numerical strategy is presented to model spalling of the concrete cover. Various numerical strategies are employed to model the behavior of reinforced concrete columns which include: (1) adjusting the material properties to incorporate restrained shrinkage; (2) modifying the plastic dilation rate in the presence of the tensile pressure; (3) adding a tension cut-off failure surface and (4) giving the concrete cover region and the column core different material properties. Numerical comparisons against experimental results are carried out that shown excellent agreement with the experimental results and justify the use of the proposed strategies to predict the axial load capacity of reinforce concrete columns.

Keywords: spalling, concrete, plastic dilation, reinforced concrete columns

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Authors: Chenhong Peng

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Beijing, the capital city of China, is running out of water. The water resource per capita in Beijing is only 106 cubic meter, accounts for 5% of the country’s average level and less than 2% of the world average level. The tension between water supply and demand is extremely serious. For one hand, the surface and ground water have been over-exploited during the last decades; for the other hand, water demand keep increasing as the result of population and economic growth. There is a massive gap between water supply and demand. This paper will focus on addressing the water shortage in Beijing city by increasing water use efficiency in domestic sector. First, we will emphasize on the changing structure of water supply and demand in Beijing under the economic development and restructure during the last decade. Second, by analyzing the water use efficiency in agriculture, industry and domestic sectors in Beijing, we identify that the key determinant for addressing the water crisis is to increase the water use efficiency in domestic sector. Third, this article will explore the two primary causes for the water use inefficiency in Beijing: The ineffective water pricing policy and the poor water education and communication policy. Finally, policy recommendation will offered to improve the water use efficiency in domestic sector by making and implementing an effective water pricing policy and people-engaged water education and communication policy.

Keywords: Beijing, water use efficiency, domestic sector, water pricing policy, water education policy

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Authors: Martin Alexander Eder, Sergei Semenov

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Many glass-epoxy composite structures, such as large utility wind turbine rotor blades (WTBs), comprise of adhesive joints with typically thick bond lines used to connect the different components during assembly. Performance optimization of rotor blades to increase power output by simultaneously maintaining high stiffness-to-low-mass ratios entails intricate geometries in conjunction with complex anisotropic material behavior. Consequently, adhesive joints in WTBs are subject to multiaxial stress states with significant stress gradients depending on the local joint geometry. Moreover, the dynamic aero-elastic interaction of the WTB with the airflow generates non-proportional, variable amplitude stress histories in the material. Empiricism shows that a prominent failure type in WTBs is high cycle fatigue failure of adhesive bond line interfaces, which in fact over time developed into a design driver as WTB sizes increase rapidly. Structural optimization employed at an early design stage, therefore, sets high demands on computationally efficient interface fatigue models capable of predicting the critical locations prone for interface failure. The numerical stress-based interface fatigue model presented in this work uses the Drucker-Prager criterion to compute three different damage indices corresponding to the two interface shear tractions and the outward normal traction. The two-parameter Drucker-Prager model was chosen because of its ability to consider shear strength enhancement under compression and shear strength reduction under tension. The governing interface damage index is taken as the maximum of the triple. The damage indices are computed through the well-known linear Palmgren-Miner rule after separate rain flow-counting of the equivalent shear stress history and the equivalent pure normal stress history. The equivalent stress signals are obtained by self-similar scaling of the Drucker-Prager surface whose shape is defined by the uniaxial tensile strength and the shear strength such that it intersects with the stress point at every time step. This approach implicitly assumes that the damage caused by the prevailing multiaxial stress state is the same as the damage caused by an amplified equivalent uniaxial stress state in the three interface directions. The model was implemented as Python plug-in for the commercially available finite element code Abaqus for its use with solid elements. The model was used to predict the interface damage of an adhesively bonded, tapered glass-epoxy composite cantilever I-beam tested by LM Wind Power under constant amplitude compression-compression tip load in the high cycle fatigue regime. Results show that the model was able to predict the location of debonding in the adhesive interface between the webfoot and the cap. Moreover, with a set of two different constant life diagrams namely in shear and tension, it was possible to predict both the fatigue lifetime and the failure mode of the sub-component with reasonable accuracy. It can be concluded that the fidelity, robustness and computational efficiency of the proposed model make it especially suitable for rapid fatigue damage screening of large 3D finite element models subject to complex dynamic load histories.

Keywords: adhesive, fatigue, interface, multiaxial stress

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Authors: Jimena Lizeth Gomez Delgado, Jhon Jairo Rodriguez, Nicolas Santos, Enrique Mejia Ospino

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Nanotechnology has played an important role in the hydrocarbon industry, recently , due to the unique properties of graphene oxide nanoparticles, they have been incorporated in different studies enhanced oil recovery. Nonetheless, very few studies have used graphene oxide nanoparticles in coreflooding experiments. Herein, the use of Graphene oxide (GO) nanoparticle was explored, exploited and evaluated. The performance of Graphene oxide nanoparticles on the interfacial properties in the presence of different electrolyte concentrations representative of field brine and pH conditions was investigated. Moreover, wettability behavior of the nanofluid at the oil/sand interface was studied used contact angle and Amott Harvey evaluation. Experimental result shows that the adsorption of GO on the sandstone surface changes the wettability of the sandstone from being strongly crude oil-wet to intermediate crude oil-wettability. At 900 ppm formation brine with 8 pH solution and 0.09 wt% nanoparticles concentration, Graphene oxide nanofluid exhibited better performance under the different electrolyte concentration studied. Finally, heavy oil displacement test in sandstone cores showed that oil recovery of Graphene oxide nanofluid had 7% incremental oil recovery over conventional waterflooding.

Keywords: nanoparticle, graphene oxide, nanotechnology, wettability, enhanced oil recovery, coreflooding

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Authors: Niloufar Khoshbakht, Peggi L. Clouston, Sanjay R. Arwade, Alexander C. Schreyer

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Laminated veneer bamboo (LVB) is a structural engineered composite made from glued layers of bamboo. A relatively new building product, LVB is currently employed in similar sizes and applications as dimensional lumber. This study describes the results of a 3D elastic Finite Element model for halfhole specimens when loaded in compression parallel-to-grain per ASTM 5764. The model simulates LVB fracture initiation due to shear stresses in the dowel joint and predicts displacement at failure validated through comparison with experimental results. The material fails at 1mm displacement due to in-plane shear stresses. The paper clarifies the complex interactive state of in-plane shear, tension perpendicular-to-grain, and compression parallel-to-grain stresses that form different distributions in the critical zone beneath the bolt hole for half-hole specimens. These findings are instrumental in understanding key factors and fundamental failure mechanisms that occur in LVB dowel connections to help devise safe standards and further LVB product adoption and design.

Keywords: composite, dowel connection, embedment strength, failure behavior, finite element analysis, Moso bamboo

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Authors: Nitai Biswas, Prasenjit Kapas, Arumay Jana, Asish Paul

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Introduction: Motivation is basic drive for all kinds of action. It has direct influence on academic achievement and sports performance that builds urge to incentive values of success. In other words, it can be defined as the need for success to attain excellence. Anxiety in pre competition especially in sports formulates positive inward settings in mind to overcome the challenge. There is a tendency to perceive competitive situations as some threatening issues and to respond them with feelings of apprehension and tension. Aim: Aim of the study was to compare the achievement motivation and competition anxiety among three different classes of students. Methods and Materials: To conduct the study the researcher has taken 131 male subjects from three different classes as Extra Department, Bachelor of Physical Education-I and Master of Physical EducationII, aged 19-28 years. Achievement motivation and sports competition anxiety were measured by the questionnaire. To analyze the data mean, standard deviation for each parameter as descriptive statistics and one way analysis of variance as inferential statistics were employed. Results: From the result of the study in achievement motivation (p ≥ 0.05) and competition anxiety (p ≥ 0.05) no significant differences were found among the said three groups. Conclusion: The study concluded that all three groups had almost the same state of achievement motivation and sports competition anxiety.

Keywords: anxiety, sports psychology, sports competition anxiety, achievement motivation, academic hierarchy, E.D., B.P.Ed., M.P.Ed

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Authors: Ngozi N. Sydney-Agbor, Chioma N. Ihegboro

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Stress and personality as factors influencing nurses’ aggressive behaviour were investigated. The participants comprised of one hundred and fifty nurses selected through convenience sampling technique from four (4) private hospitals in Imo State, Nigeria; namely: Eastern Summit Specialist Clinics and Maternity, St. David Hospital, New Cross Hospital, and Christian Teaching Hospital. The nurses were all females with ages between 20–35 and a mean age of 25.10 years and a standard deviation of 4.15. The participants were administered with Job Related Tension Scale, Type A Behaviour Scale and Buss- Perry Aggressive Behaviour Scale. Two hypotheses were postulated and tested. Cross- sectional survey and Regression Analysis were adopted as design and statistics respectively. Results showed that as stress increased, nurses aggression also increased. Personality also predicted nurses aggressive behaviour with Type As’ exhibiting higher aggression than Type Bs’.The study recommended that hospital management board should improve the welfare of the nurses and their morale should be boosted by involving them in policy-making concerning their welfare and care of their patients, this will help minimise situations capable of increasing aggressive behaviour. There should also be sensitization on the negative impact of aggressive behaviour to patients especially amongst the personality Type A’s who are more susceptible to aggression.

Keywords: aggressive behaviour, nurses, personality, stress

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Authors: J. Ramos, V. Gil, A. F. Torres

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The nodular iron is a material that has shown great advantages respect to other materials (steel and gray iron) in the production of machine elements. The engineering industry, especially automobile, are potential users of this material. As it is known, the alloying elements modify the properties of steels and castings. Copper has been investigated as a structural modifier of nodular iron, but studies of its mechanical and tribological implications still need to be addressed for industrial use. With the aim of improving the mechanical properties of nodular iron, alloying elements (Mn, Si, and Cu) are added in order to increase their pearlite (or ferrite) structure according to the percentage of the alloying element. In this research (using induction furnace process) nodular iron with three different percentages of copper (residual, 0,5% and 1,2%) was obtained. Chemical analysis was performed by optical emission spectrometry and microstructures were characterized by Optical Microscopy (ASTM E3) and Scanning Electron Microscopy (SEM). The study of mechanical behavior was carried out in a mechanical test machine (ASTM E8) and a Pin on disk tribometer (ASTM G99) was used to assess wear resistance. It is observed that copper increases the pearlite structure improving the wear behavior; tension behavior. This improvement is observed in higher proportion with 0,5% due to the fact that too much increase of pearlite leads to ductility loss.

Keywords: copper, mechanical properties, nodular iron, pearlite structure, wear

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Authors: Prajwal Raj Gyawali, Aastha Dahal

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The tension between human rights and loans provided by international development banks with hidden conditions in the pretext of development is a complex issue with significant implications for the rights of citizens in borrowing countries. It is important for all parties involved, including international banks, borrowing countries, and affected communities, to consider and respect human rights in the negotiation and implementation of development projects. Yet, it is rare for human rights actors or communities to have a seat at the negotiation table when loans are finalized. In our research, we conducted negotiation simulations in law schools to examine how international loan negotiations would play out if human rights actors and communities had seats at the table. We ran the negotiation simulations in Bangladesh, Nepal and India. We found that the presence of community groups and human rights actors makes a difference in loan outcomes. While the international development loan was accepted as opposed to rejected by negotiators in three countries, the cultural values of the respective countries played a significant part in terms of the final agreement. We present the findings and their implications for the design of human rights courses in law schools as well as larger policy implications for expanding the participation of actors in international development loan negotiations.

Keywords: law, development, debt, human rights

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Authors: Chul-Hee Jo, Do-Youb Kim, Seok-Jin Cho, Yu-Ho Rho

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The Catenary Anchor Leg Mooring (CALM) Single Point Mooring (SPM) buoy system is the most popular and widely used type of offshore loading terminals. SPM buoy mooring systems have been deployed worldwide for a variety of applications, water depths and vessel sizes ranging from small production carriers to Very Large Crude Carriers (VLCCs). Because of safe and easy berthing and un-berthing operations, the SPM buoy mooring system is also preferred for offshore terminals. The SPM buoy consists of a buoy that is permanently moored to the seabed by means of multiple mooring lines. The buoy contains a bearing system that allows a part of it to rotate around the moored geostatic part. When moored to the rotating part of the buoy, a vessel is able to freely weathervane around the buoy. This study was verified the effects of design variables in order to design an SPM buoy mooring system through parametric analysis. The design variables have independent and nonlinear characteristics. Using parametric analysis, this research was found that the fairlead departure angle, wave height and period, chain diameter and line length effect to the mooring top tension, buoy excursion and line layback.

Keywords: Single Point Mooring (SPM), Catenary Anchor Leg Mooring(CALM), design variables, parametric analysis, mooring system optimization

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Authors: Masoud Ghermezi

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Studying the sheet metals is one of the most important research areas in the field of metal forming due to their extensive applications in the aerospace industries. A useful method for determining the forming limit of these materials and consequently preventing the rupture of sheet metals during the forming process is the use of the forming limit curve (FLC). In addition to specifying the forming limit, this curve also delineates a boundary for the allowed values of strain in sheet metal forming; these characteristics of the FLC along with its accuracy of computation and wide range of applications have made this curve the basis of research in the present paper. This study presents a new model that not only agrees with the results obtained from the above mentioned theory, but also eliminates its shortcomings. In this theory, like in the M-K theory, a thin sheet with an inhomogeneity as a gradient thickness reduction with a sinusoidal function has been chosen and subjected to two-dimensional stress. Through analytical evaluation, ultimately, a governing differential equation has been obtained. The numerical solution of this equation for the range of positive strains (stretched region) yields the results that agree with the results obtained from M-K theory. Also the solution of this equation for the range of negative strains (tension region) completes the FLC curve. The findings obtained by applying this equation on two alloys with the hardening exponents of 0.4 and 0.24 indicate the validity of the presented equation.

Keywords: sheet metal, metal forming, forming limit curve (FLC), M-K theory

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Authors: Ajay Kumar Choubey, Geeta Agnihotri, C. Sasikumar, Rashmi Dwivedi

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Deep-drawing operations are performed widely in industrial applications. It is very important for efficiency to achieve parts with no or minimum defects. Deep drawn parts are used in high performance, high strength and high reliability applications where tension, stress, load and human safety are critical considerations. Wrinkling is a kind of defect caused by stresses in the flange part of the blank during metal forming operations. To avoid wrinkling appropriate blank-holder pressure/force or drawbead can be applied. Now-a-day computer simulation plays a vital role in the field of manufacturing process. So computer simulation of manufacturing has much advantage over previous conventional process i.e. mass production, good quality of product, fast working etc. In this study, a two dimensional elasto-plastic Finite Element (F.E.) model for Mild Steel material blank has been developed to study the behavior of the flange wrinkling and deep drawing parameters under different Blank-Holder Pressure (B.H.P.). For this, commercially available Finite Element software ANSYS 14 has been used in this study. Simulation results are critically studied and salient conclusions have been drawn.

Keywords: ANSYS, deep drawing, BHP, finite element simulation, wrinkling

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Authors: Chongyang Ye, Rong Liu

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Compression textiles such as compression stockings (CSs) have been extensively applied for the prevention and treatment of chronic venous insufficiency of lower extremities. The involvement of multiple mechanical factors such as interface pressure, frictional force, and elastic materials make the interactions between lower limb and CSs to be complex. Determination of Poisson’s ratio and elastic moduli of CS materials are critical for constructing finite element (FE) modeling to numerically simulate a complex interactive system of CS and lower limb. In this study, a mixed approach, including an analytic model based on the orthotropic Hooke’s Law and experimental study (uniaxial tension testing and pure shear testing), has been proposed to determine Young’s modulus, Poisson’s ratio, and shear modulus of CS fabrics. The results indicated a linear relationship existing between the stress and strain properties of the studied CS samples under controlled stretch ratios (< 100%). The newly proposed method and the determined key mechanical properties of elastic orthotropic CS fabrics facilitate FE modeling for analyzing in-depth the effects of compression material design on their resultant biomechanical function in compression therapy.

Keywords: elastic compression stockings, Young’s modulus, Poisson’s ratio, shear modulus, mechanical analysis

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Authors: Sena Su, Burak Ozbek, Yesim M. Sahin, Sevil Yucel, Dilek Kazan, Faik N. Oktar, Nazmi Ekren, Oguzhan Gunduz

Abstract:

In recent years, protein, lipid or polysaccharide-based polymers have been used in order to develop biodegradable materials and their chemical nature determines the physical properties of the resulting films. Among these polymers, proteins from different sources have been extensively employed because of their relative abundance, film forming ability, and nutritional qualities. In this study, the biodegradable composite nanofiber films based on fish sarcoplasmic protein (FSP) were prepared via electrospinning technique. Biodegradable polycaprolactone (PCL) was blended with the FSP to obtain hybrid FSP/PCL nanofiber mats with desirable physical properties. Mixture solutions of FSP and PCL were produced at different concentrations and their density, viscosity, electrical conductivity and surface tension were measured. Mechanical properties of electrospun nanofibers were evaluated. Morphology of composite nanofibers was observed using scanning electron microscopy (SEM). Moreover, Fourier transform infrared spectrometer (FTIR) studies were used for analysis chemical composition of composite nanofibers. This study revealed that the FSP based nanofibers have the potential to be used for different applications such as biodegradable packaging, drug delivery, and wound dressing, etc.

Keywords: edible film, electrospinning, fish sarcoplasmic protein, nanofiber

Procedia PDF Downloads 275

Authors: Rouaz Idriss, Bourahla Nour-Eddine, Kahlouche Farah, Rafa Sid Ali

Abstract:

The stability of structures made of light-gauge steel depends highly on the contribution of Shear Wall Panel (SWP) systems under horizontal forces due to wind or earthquake loads. Steel plate sheathing is often used with these panels made of cold formed steel (CFS) to improve its shear strength. In order to predict the shear strength resistance, two methods are presented in this paper. In the first method, the steel plate sheathing is modeled with plats strip taking into account only the tension and compression force due to the horizontal load, where both track and stud are modeled according to the geometrical and mechanical characteristics of the specimen used in the experiments. The theoretical background and empirical formulations of this method are presented in this paper. However, the second method is based on a micro modeling of the cold formed steel Shear Wall Panel “CFS-SWP” using Abaqus software. A nonlinear analysis was carried out with an in-plan monotonic load. Finally, the comparison between these two methods shows that the micro modeling with Abaqus gives better prediction of shear resistance of SWP than strips method. However, the latter is easier and less time consuming than the micro modeling method.

Keywords: cold formed steel 'CFS', shear wall panel, strip method, finite elements

Procedia PDF Downloads 281

Authors: A. Siva, R. Senthil, R. Banupriya, R. Saravanakumar

Abstract:

Cold-formed steel sheets are widely used as primary tension reinforcement in composite slabs. It also performs as formwork for concreting and better ceiling surface. The major type of failure occurring in composite slab is shear failure. When the composite slab is flexurally loaded, the longitudinal shear is generated and transferred to the steel sheet concrete interface. When the load increases, the interface slip occurs. The slip failure can be resisted by mechanical interface interlock by shear studs. In this paper, the slip failure has been resisted by shear connectors and geometry of the steel sheet alone. The geometry of the sheet is kept constant for all the specimens and the type of shear connectors has been varied. Totally, three types of shear connectors (viz., straight headed, U and J) are bolted to the trapezoidal profile sheet and the concrete is casted over it. After curing, the composite slab is subjected to flexure load and the test results are compared with the numerical results analysed by ABAQUS software. The test result shows that the U-shaped bolted stud has higher flexure strength than the other two types of shear connectors.

Keywords: cold formed steel sheet, headed studs, mechanical interlock, shear connectors, shear failure, slip failure

Procedia PDF Downloads 530

Authors: Faci Youcef

Abstract:

In the present work, an experimental study is carried out using the digital image correlation (DIC) technique to analyze the damage and behavior of woven composite carbon/epoxy under tensile loading. The tension mechanisms associated with failure modes of bolted joints in advanced composites are studied, as well as displacement distribution and strain distribution. The evolution value of bolt angle inclination during tensile tests was studied. In order to compare the distribution of displacements and strains along the surface, figures of image mapping are made. Several factors that are responsible for the failure of fiber-reinforced polymer composite materials are observed. It was found that strain concentrations observed in the specimens can be used to identify full-field damage onset and to monitor damage progression during loading. Moreover, there is an interaction between laminate pattern, laminate thickness, fastener size and type, surface strain concentrations, and out-of-plane displacement. Conclusions include a failure analysis associated with bolt angle inclinations and supported by microscopic visualizations of the composite specimen. The DIC results can be used to develop and accurately validate numerical models.

Keywords: Carbone, woven, damage, digital image, bolted joint, the inclination of angle

Procedia PDF Downloads 45

Authors: S. N. Al-Bahry, Y. M. Al-Wahaibi, S. J. Joshi, E. A. Elshafie, A. S. Al-Bimani

Abstract:

Oman is one of the oil producing countries in the Arabian Peninsula and the Gulf region. About 30-40 % of oil produced from the Gulf is transported globally along the seacoast of Oman. Oil pollution from normal tanker operations, ballast water, illegal discharges and accidental spills are always serious threats to terrestrial and marine habitats. Due to Oman’s geographical location at arid region where the temperature ranges between high 40s and low 50s Celsius in summers with low annual rainfall, the main source of fresh water is desalinated sea and brackish water. Oil pollution, therefore, pose a major threat to drinking water. Biosurfactants are secondary metabolites produced by microorganisms in hydrophobic environments to release nutrients from solid surfaces, such as oil. In this study, indigenous oil degrading thermophilic spore forming bacteria were isolated from oil fields contaminated soil. The isolates were identified using MALDI-TOF biotyper and 16s RNA. Their growth conditions were optimized for the production of biosurfactant. Surface tension, interfacial tensions and microbial oil biodegradation capabilities were tested. Some thermophilic bacteria degraded either completely or partially heavy crude oil (API 10-15) within 48h suggesting their high potential in oil spill bioremediation and avoiding the commonly used physical and chemical methods which usually lead to other environmental pollution.

Keywords: bacteria, bioremediation, biosurfactant, crude-oil-pollution

Procedia PDF Downloads 385

Authors: Badr Alsulami, Ahmed S. Elamary

Abstract:

This paper summarizes and presents main results of an in-depth numerical analysis dealing with the shear buckling resistance of aluminum plate girders. The studies conducted have permitted the development of a simple design expression to determine the critical shear buckling stress in aluminum web panels. This expression takes into account the effects of reduction of strength in aluminum alloys due to the welding process. Ultimate shear resistance (USR) of plate girders can be obtained theoretically using Cardiff theory or Hӧglund’s theory. USR of aluminum alloy plate girders predicted theoretically using BS8118 appear inconsistent when compared with test data. Theoretical predictions based on Hӧglund’s theory, are more realistic. Cardiff theory proposed to predict the USR of steel plate girders only. Welded aluminum alloy plate girders studied experimentally by others; the USR resulted from tests are reviewed. Comparison between the test results with the values obtained from Hӧglund’s theory, BS8118 design method, and Cardiff theory performed theoretically. Finally, a new equation based on Cardiff tension-field theory proposed to predict theoretically the USR of aluminum plate girders.

Keywords: shear resistance, aluminum, Cardiff theory, Hӧglund's theory, plate girder

Procedia PDF Downloads 379