Search results for: wave impact loads
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 12792

Search results for: wave impact loads

10752 Comparative Investigation of Two Non-Contact Prototype Designs Based on a Squeeze-Film Levitation Approach

Authors: A. Almurshedi, M. Atherton, C. Mares, T. Stolarski, M. Miyatake

Abstract:

Transportation and handling of delicate and lightweight objects is currently a significant issue in some industries. Two common contactless movement prototype designs, ultrasonic transducer design and vibrating plate design, are compared. Both designs are based on the method of squeeze-film levitation, and this study aims to identify the limitations, and challenges of each. The designs are evaluated in terms of levitation capabilities, and characteristics. To this end, theoretical and experimental explorations are made. It is demonstrated that the ultrasonic transducer prototype design is better suited to the terms of levitation capabilities. However, the design has some operating and mechanical designing difficulties. For making accurate industrial products in micro-fabrication and nanotechnology contexts, such as semiconductor silicon wafers, micro-components and integrated circuits, non-contact oil-free, ultra-precision and low wear transport along the production line is crucial for enabling. One of the designs (design A) is called the ultrasonic chuck, for which an ultrasonic transducer (Langevin, FBI 28452 HS) comprises the main part. Whereas the other (design B), is a vibrating plate design, which consists of a plain rectangular plate made of Aluminium firmly fastened at both ends. The size of the rectangular plate is 200x100x2 mm. In addition, four rounded piezoelectric actuators of size 28 mm diameter with 0.5 mm thickness are glued to the underside of the plate. The vibrating plate is clamped at both ends in the horizontal plane through a steel supporting structure. In addition, the dynamic of levitation using the designs (A and B) has been investigated based on the squeeze film levitation (SFL). The input apparatus that is used with designs consist of a sine wave signal generator connected to an amplifier type ENP-1-1U (Echo Electronics). The latter has to be utilised to magnify the sine wave voltage that is produced by the signal generator. The measurements of the maximum levitation for three different semiconductor wafers of weights 52, 70 and 88 [g] for design A are 240, 205 and 187 [um], respectively. Whereas the physical results show that the average separation distance for a disk of 5 [g] weight for design B reaches 70 [um]. By using the methodology of squeeze film levitation, it is possible to hold an object in a non-contact manner. The analyses of the investigation outcomes signify that the non-contact levitation of design A provides more improvement than design B. However, design A is more complicated than design B in terms of its manufacturing. In order to identify an adequate non-contact SFL design, a comparison between two common such designs has been adopted for the current investigation. Specifically, the study will involve making comparisons in terms of the following issues: floating component geometries and material type constraints; final created pressure distributions; dangerous interactions with the surrounding space; working environment constraints; and complication and compactness of the mechanical design. Considering all these matters is essential for proficiently distinguish the better SFL design.

Keywords: ANSYS, floating, piezoelectric, squeeze-film

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10751 The Effects of Dual-Enrollment Programs on Students’ Post-Secondary Academic Performance

Authors: Cody Kirby, Kaustav Misra, Arundhati Bagchi Misra, Sharon P. Cox

Abstract:

This paper focuses on the relationship that dual-enrollment programs have on academic performance and retention. Both performance and retention are significant issues in higher education. The first, performance, is a goal of higher education, having an impact on students’ lives. The second, retention, is key to the viability of any college or university. This paper uses survey research methodology to examine factors that lead to positive student academic performance, which leads to retention, specifically in dual-enrollment programs. The data show several characteristics that lead to a positive impact on GPA. These include the following; age, Caucasian race, full-time status, students in STEM programs, and finally dual enrollment participation.

Keywords: dual enrollment, early college, retention, undergraduate education

Procedia PDF Downloads 141
10750 The Optimization of an Industrial Recycling Line: Improving the Durability of Recycled Polyethyene Blends

Authors: Alae Lamtai, Said Elkoun, Hniya Kharmoudi, Mathieu Robert, Carl Diez

Abstract:

This study applies Taguchi's design of experiment methodology and grey relational analysis (GRA) for multi objective optimization of an industrial recycling line. This last is composed mainly of a mono and twin-screw extruder and a filtration system. Experiments were performed according to L₁₆ standard orthogonal array based on five process parameters, namely: mono screw design, screw speed of the mono and twin-screw extruder, melt pump pressure, and filter mesh size. The objective of this optimization is to improve the durability of the Polyethylene (PE) blend by decreasing the loss of Stress Crack resistance (SCR) using Notched Crack Ligament Stress (NCLS) test and Unnotched Crack Ligament Stress (UCLS) in parallel with increasing the gain of Izod impact strength of the Polyethylene (PE) blend before and after recycling. Based on Grey Relational Analysis (GRA), the optimal setting of process parameters was identified, and the results indicated that the mono-screw design and screw speed of both mono and twin-screw extruder impact significantly the mechanical properties of recycled Polyethylene (PE) blend.

Keywords: Taguchi, recycling line, polyethylene, stress crack resistance, Izod impact strength, grey relational analysis

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10749 Analysis of the Gait Characteristics of Soldier between the Normal and Loaded Gait

Authors: Ji-il Park, Min Kyu Yu, Jong-woo Lee, Sam-hyeon Yoo

Abstract:

The purpose of this research is to analyze the gait strategy between the normal and loaded gait. To this end, five male participants satisfied two conditions: the normal and loaded gait (backpack load 25.2 kg). As expected, results showed that additional loads elicited not a proportional increase in vertical and shear ground reaction force (GRF) parameters but also increase of the impulse, momentum and mechanical work. However, in case of the loaded gait, the time duration of the double support phase was increased unexpectedly. It is because the double support phase which is more stable than the single support phase can reduce instability of the loaded gait. Also, the directions of the pre-collision and after-collision were moved upward and downward compared to the normal gait. As a result, regardless of the additional backpack load, the impulse-momentum diagram during the step-to-step transition was maintained such as the normal gait. It means that human walk efficiently to keep stability and minimize total net works in case of the loaded gait.

Keywords: normal gait, loaded gait, impulse, collision, gait analysis, mechanical work, backpack load

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10748 Comparison of Dynamic Characteristics of Railway Bridge Spans to Know the Health of Elastomeric Bearings Using Tri Axial Accelerometer Sensors

Authors: Narayanakumar Somasundaram, Venkat Nihit Chirivella, Venkata Dilip Kumar Pasupuleti

Abstract:

Ajakool, India, has a multi-span bridge that is constructed for rail transport with a maximum operating speed of 100 km/hr. It is a standard RDSO design of a PSC box girder carrying a single railway track. The Structural Health Monitoring System (SHM) is designed and installed to compare and analyze the vibrations and displacements on the bridge due to different live loads from moving trains. The study is conducted for three different spans of the same bridge to understand the health of the elastomeric bearings. Also, to validate the same, a three-dimensional finite element model is developed, and modal analysis is carried out. The proposed methodology can help in detecting deteriorated elastomeric bearings using only wireless tri-accelerometer sensors. Detailed analysis and results are presented in terms of mode shapes, accelerations, displacements, and their importance to each other. This can be implemented with a lot of ease and can be more accurate.

Keywords: dynamic effects, vibration analysis, accelerometer sensors, finite element analysis, structural health monitoring, elastomeric bearing

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10747 Ecopath Analysis of Trophic Structure in Moroccan Mediterranean Sea and Atlantic Ocean

Authors: Salma Aboussalam, Karima Khalil, Khalid Elkalay

Abstract:

The Ecopath model was utilized to evaluate the trophic structure, function, and current status of the Moroccan Mediterranean Sea ecosystem. The model incorporated 31 functional groups, including fish species, invertebrates, primary producers, and detritus. Through the analysis of trophic interactions among these groups, an average trophic transfer efficiency of 23% was found. The findings revealed that the ecosystem produced more energy than it consumed, with high respiration and consumption rates. Indicators of stability and development were low, indicating that the ecosystem is disturbed by a linear trophic structure. Additionally, keystone species were identified through the use of the keystone index and mixed trophic impact analysis, with demersal invertebrates, zooplankton, and cephalopods found to have a significant impact on other groups.

Keywords: ecopath, food web, trophic flux, Moroccan Mediterranean Sea

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10746 Experimental Study of Energy Absorption Efficiency (EAE) of Warp-Knitted Spacer Fabric Reinforced Foam (WKSFRF) Under Low-Velocity Impact

Authors: Amirhossein Dodankeh, Hadi Dabiryan, Saeed Hamze

Abstract:

Using fabrics to reinforce composites considerably leads to improved mechanical properties, including resistance to the impact load and the energy absorption of composites. Warp-knitted spacer fabrics (WKSF) are fabrics consisting of two layers of warp-knitted fabric connected by pile yarns. These connections create a space between the layers filled by pile yarns and give the fabric a three-dimensional shape. Today because of the unique properties of spacer fabrics, they are widely used in the transportation, construction, and sports industries. Polyurethane (PU) foams are commonly used as energy absorbers, but WKSF has much better properties in moisture transfer, compressive properties, and lower heat resistance than PU foam. It seems that the use of warp-knitted spacer fabric reinforced PU foam (WKSFRF) can lead to the production and use of composite, which has better properties in terms of energy absorption from the foam, its mold formation is enhanced, and its mechanical properties have been improved. In this paper, the energy absorption efficiency (EAE) of WKSFRF under low-velocity impact is investigated experimentally. The contribution of the effect of each of the structural parameters of the WKSF on the absorption of impact energy has also been investigated. For this purpose, WKSF with different structures such as two different thicknesses, small and large mesh sizes, and position of the meshes facing each other and not facing each other were produced. Then 6 types of composite samples with different structural parameters were fabricated. The physical properties of samples like weight per unit area and fiber volume fraction of composite were measured for 3 samples of any type of composites. Low-velocity impact with an initial energy of 5 J was carried out on 3 samples of any type of composite. The output of the low-velocity impact test is acceleration-time (A-T) graph with a lot deviation point, in order to achieve the appropriate results, these points were removed using the FILTFILT function of MATLAB R2018a. Using Newtonian laws of physics force-displacement (F-D) graph was drawn from an A-T graph. We know that the amount of energy absorbed is equal to the area under the F-D curve. Determination shows the maximum energy absorption is 2.858 J which is related to the samples reinforced with fabric with large mesh, high thickness, and not facing of the meshes relative to each other. An index called energy absorption efficiency was defined, which means absorption energy of any kind of our composite divided by its fiber volume fraction. With using this index, the best EAE between the samples is 21.6 that occurs in the sample with large mesh, high thickness, and meshes facing each other. Also, the EAE of this sample is 15.6% better than the average EAE of other composite samples. Generally, the energy absorption on average has been increased 21.2% by increasing the thickness, 9.5% by increasing the size of the meshes from small to big, and 47.3% by changing the position of the meshes from facing to non-facing.

Keywords: composites, energy absorption efficiency, foam, geometrical parameters, low-velocity impact, warp-knitted spacer fabric

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10745 Monitoring Future Climate Changes Pattern over Major Cities in Ghana Using Coupled Modeled Intercomparison Project Phase 5, Support Vector Machine, and Random Forest Modeling

Authors: Stephen Dankwa, Zheng Wenfeng, Xiaolu Li

Abstract:

Climate change is recently gaining the attention of many countries across the world. Climate change, which is also known as global warming, referring to the increasing in average surface temperature has been a concern to the Environmental Protection Agency of Ghana. Recently, Ghana has become vulnerable to the effect of the climate change as a result of the dependence of the majority of the population on agriculture. The clearing down of trees to grow crops and burning of charcoal in the country has been a contributing factor to the rise in temperature nowadays in the country as a result of releasing of carbon dioxide and greenhouse gases into the air. Recently, petroleum stations across the cities have been on fire due to this climate changes and which have position Ghana in a way not able to withstand this climate event. As a result, the significant of this research paper is to project how the rise in the average surface temperature will be like at the end of the mid-21st century when agriculture and deforestation are allowed to continue for some time in the country. This study uses the Coupled Modeled Intercomparison Project phase 5 (CMIP5) experiment RCP 8.5 model output data to monitor the future climate changes from 2041-2050, at the end of the mid-21st century over the ten (10) major cities (Accra, Bolgatanga, Cape Coast, Koforidua, Kumasi, Sekondi-Takoradi, Sunyani, Ho, Tamale, Wa) in Ghana. In the models, Support Vector Machine and Random forest, where the cities as a function of heat wave metrics (minimum temperature, maximum temperature, mean temperature, heat wave duration and number of heat waves) assisted to provide more than 50% accuracy to predict and monitor the pattern of the surface air temperature. The findings identified were that the near-surface air temperature will rise between 1°C-2°C (degrees Celsius) over the coastal cities (Accra, Cape Coast, Sekondi-Takoradi). The temperature over Kumasi, Ho and Sunyani by the end of 2050 will rise by 1°C. In Koforidua, it will rise between 1°C-2°C. The temperature will rise in Bolgatanga, Tamale and Wa by 0.5°C by 2050. This indicates how the coastal and the southern part of the country are becoming hotter compared with the north, even though the northern part is the hottest. During heat waves from 2041-2050, Bolgatanga, Tamale, and Wa will experience the highest mean daily air temperature between 34°C-36°C. Kumasi, Koforidua, and Sunyani will experience about 34°C. The coastal cities (Accra, Cape Coast, Sekondi-Takoradi) will experience below 32°C. Even though, the coastal cities will experience the lowest mean temperature, they will have the highest number of heat waves about 62. Majority of the heat waves will last between 2 to 10 days with the maximum 30 days. The surface temperature will continue to rise by the end of the mid-21st century (2041-2050) over the major cities in Ghana and so needs to be addressed to the Environmental Protection Agency in Ghana in order to mitigate this problem.

Keywords: climate changes, CMIP5, Ghana, heat waves, random forest, SVM

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10744 Towards a Doughnut Economy: The Role of Institutional Failure

Authors: Ghada El-Husseiny, Dina Yousri, Christian Richter

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Social services are often characterized by market failures, which justifies government intervention in the provision of these services. It is widely acknowledged that government intervention breeds corruption since resources are being transferred from one party to another. However, what is still being extensively studied is the magnitude of the negative impact of corruption on publicly provided services and development outcomes. Corruption has the power to hinder development and cripple our march towards the Sustainable Development Goals. Corruption diminishes the efficiency and effectiveness of public health and education spending and directly impacts the outcomes of these sectors. This paper empirically examines the impact of Institutional Failure on public sector services provision, with the sole purpose of studying the impact of corruption on SDG3 and 4; Good health and wellbeing and Quality education, respectively. The paper explores the effect of corruption on these goals from various perspectives and extends the analysis by examining if the impact of corruption on these goals differed when it accounted for the current corruption state. Using Pooled OLS(Ordinary Least Square) and Fixed effects panel estimation on 22 corrupt and 22 clean countries between 2000 and 2017. Results show that corruption in both corrupt and clean countries has a more severe impact on Health than the Education sector. In almost all specifications, corruption has an insignificant effect on School Enrollment rates but a significant effect on Infant Mortality rates. Results further indicate that, on average, a 1 point increase in the CPI(Consumer Price Index) can increase health expenditures by 0.116% in corrupt and clean countries. However, the fixed effects model indicates that the way Health and Education expenditures are determined in clean and corrupt countries are completely country-specific, in which corruption plays a minimal role. Moreover, the findings show that School Enrollment rates and Infant Mortality rates depend, to a large extent, on public spending. The most astounding results-driven is that corrupt countries, on average, have more effective and efficient healthcare expenditures. While some insights are provided as to why these results prevail, they should be further researched. All in all, corruption impedes development outcomes, and any Anti-corrupt policies taken will bring forth immense improvements and speed up the march towards sustainability.

Keywords: corruption, education, health, public spending, sustainable development

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10743 Holistic Simulation-Based Impact Analysis Framework for Sustainable Manufacturing

Authors: Mijoh A. Gbededo, Kapila Liyanage, Sabuj Mallik

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The emerging approaches to sustainable manufacturing are considered to be solution-oriented with the aim of addressing the environmental, economic and social issues holistically. However, the analysis of the interdependencies amongst the three sustainability dimensions has not been fully captured in the literature. In a recent review of approaches to sustainable manufacturing, two categories of techniques are identified: 1) Sustainable Product Development (SPD), and 2) Sustainability Performance Assessment (SPA) techniques. The challenges of the approaches are not only related to the arguments and misconceptions of the relationships between the techniques and sustainable development but also to the inability to capture and integrate the three sustainability dimensions. This requires a clear definition of some of the approaches and a road-map to the development of a holistic approach that supports sustainability decision-making. In this context, eco-innovation, social impact assessment, and life cycle sustainability analysis play an important role. This paper deployed an integrative approach that enabled amalgamation of sustainable manufacturing approaches and the theories of reciprocity and motivation into a holistic simulation-based impact analysis framework. The findings in this research have the potential to guide sustainability analysts to capture the aspects of the three sustainability dimensions into an analytical model. Additionally, the research findings presented can aid the construction of a holistic simulation model of a sustainable manufacturing and support effective decision-making.

Keywords: life cycle sustainability analysis, sustainable manufacturing, sustainability performance assessment, sustainable product development

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10742 The Environmental Impacts of Textiles Reuse and Recycling: A Review on Life-Cycle-Assessment Publications

Authors: Samuele Abagnato, Lucia Rigamonti

Abstract:

Life-Cycle-Assessment (LCA) is an effective tool to quantify the environmental impacts of reuse models and recycling technologies for textiles. In this work, publications in the last ten years about LCA on textile waste are classified according to location, goal and scope, functional unit, waste composition, impact assessment method, impact categories, and sensitivity analysis. Twenty papers have been selected: 50% are focused only on recycling, 30% only on reuse, the 15% on both, while only one paper considers only the final disposal of the waste. It is found that reuse is generally the best way to decrease the environmental impacts of textiles waste management because of the avoided impacts of manufacturing a new item. In the comparison between a product made with recycled yarns and a product from virgin materials, in general, the first option is less impact, especially for the categories of climate change, water depletion, and land occupation, while for other categories, such as eutrophication or ecotoxicity, under certain conditions the impacts of the recycled fibres can be higher. Cultivation seems to have quite high impacts when natural fibres are involved, especially in the land use and water depletion categories, while manufacturing requires a remarkable amount of electricity, with its associated impact on climate change. In the analysis of the reuse processes, relevant importance is covered by the laundry phase, with water consumption and impacts related to the use of detergents. About the sensitivity analysis, it can be stated that one of the main variables that influence the LCA results and that needs to be further investigated in the modeling of the LCA system about this topic is the substitution rate between recycled and virgin fibres, that is the amount of recycled material that can be used in place of virgin one. Related to this, also the yield of the recycling processes has a strong influence on the results of the impact. The substitution rate is also important in the modeling of the reuse processes because it represents the number of avoided new items bought in place of the reused ones. Another aspect that appears to have a large influence on the impacts is consumer behaviour during the use phase (for example, the number of uses between two laundry cycles). In conclusion, to have a deeper knowledge of the impacts of a life-cycle approach of textile waste, further data and research are needed in the modeling of the substitution rate and of the use phase habits of the consumers.

Keywords: environmental impacts, life-cycle-assessment, textiles recycling, textiles reuse, textiles waste management

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10741 Monthly Labor Forces Surveys Portray Smooth Labor Markets and Bias Fixed Effects Estimation: Evidence from Israel’s Transition from Quarterly to Monthly Surveys

Authors: Haggay Etkes

Abstract:

This study provides evidence for the impact of monthly interviews conducted for the Israeli Labor Force Surveys (LFSs) on estimated flows between labor force (LF) statuses and on coefficients in fixed-effects estimations. The study uses the natural experiment of parallel interviews for the quarterly and the monthly LFSs in Israel in 2011 for demonstrating that the Labor Force Participation (LFP) rate of Jewish persons who participated in the monthly LFS increased between interviews, while in the quarterly LFS it decreased. Interestingly, the estimated impact on the LFP rate of self-reporting individuals is 2.6–3.5 percentage points while the impact on the LFP rate of individuals whose data was reported by another member of their household (a proxy), is lower and statistically insignificant. The relative increase of the LFP rate in the monthly survey is a result of a lower rate of exit from the LF and a somewhat higher rate of entry into the LF relative to these flows in the quarterly survey. These differing flows have a bearing on labor search models as the monthly survey portrays a labor market with less friction and a “steady state” LFP rate that is 5.9 percentage points higher than the quarterly survey. The study also demonstrates that monthly interviews affect a specific group (45–64 year-olds); thus the sign of coefficient of age as an explanatory variable in fixed-effects regressions on LFP is negative in the monthly survey and positive in the quarterly survey.

Keywords: measurement error, surveys, search, LFSs

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10740 Opening of North Sea Route and Geopolitics in Arctic: Impact and Possibilities of Route

Authors: Nikkey Keshri

Abstract:

Arctic is a polar region located at the north of the earth. This consists of the Arctic Ocean and other parts of Canada, Russia, the United States, Denmark, Norway, Sweden, Finland, and Iceland. Arctic has vast natural resources which are exploited with modern technology, and the economic opening up of Russia has given new opportunities. All these states have connected with the Arctic region for economic activities and this effect the region ecology. The pollution problem is a serious threat to the people health living around pollution sources. Due to the prevailing worldwide sea and air currents, the Arctic area is the fallout region for long-range transport pollutants, and in some places the concentrations exceed the levels of densely populated urban areas. The Arctic is especially vulnerable to the effects of global warming, as has become apparent in the melting sea ice in recent years. Climate models predict much greater warming in the Arctic than the global average, resulting in significant international attention to the region. The global warming has an adverse impact on the climate, indigenous people, wildlife, and infrastructure. However, there are several opportunities that have emerged in the form of shipping routes, resources, and new territories. The shipping route through the Arctic is a reality and is currently navigable for a few weeks during summers. There are large deposits of oil and gas, minerals and fish and the surrounding countries with Arctic coastlines are becoming quite assertive about exercising their sovereignty over the newfound wealth. The main part of the research is that how the opening of Northern Sea Route is providing opportunities or problem in the Arctic and it is becoming geopolitically important. It focuses on the interest Arctic and non Arctic states, their present and anticipated global geopolitical aims. The Northern Sea Route might open up due to climate changes and that Iceland might benefit or has an impact from the situation. Efforts will be made to answer the research question: ‘Whether Opening of North Sea Route is providing opportunities or becoming a risk for Arctic region?’ Every research has a structure which usually called design. In this research, both Qualitative and Quantitative method is used in terms of various literature, maps, pie- charts, etc to find out the answer for the research question. The aim of this research is to find out the impact of Opening of North Sea Route over Arctic region and how this make arctic geopolitically important. The aim behind this research is to find out the impact of climate change and how the particular geographical area is being affected.

Keywords: climate change, geopolitics, international relation, Northern Sea Route

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10739 Digital Divide and Its Impact on the Students’ Performance

Authors: Aissa Hanifi

Abstract:

People across different world societies are using information and communication technology (ICT) for different purposes. Unfortunately, in contemporary societies, some people have little access to ICT and thus cannot have effective participation in society compared with those who have better access. The purpose of this study is to test the impact of ICTs on university life in general and students' performance in particular. The study relied on an online survey questionnaire that was administered to 30 undergraduate students at Chef University. The findings of the survey revealed that there is still an important number of students who do not have easy access to ICT. Such limited access to ICTs is attributed to varied factors. Some students live in rural areas, where due to the poor internet coverage, they face difficulties in competing with students who live in urban areas with better ICT access. The lack of ICT access has hindered the students' university performance in general and their language skills, and the exchange of information with teachers and classmates.

Keywords: access, communication, ICT, performance, technology

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10738 Climate Change and Migration from Ngala and Kala-Balge LGAs, North-Eastern Borno State, Nigeria

Authors: Adam Modu Abbas

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Nigeria, due to its location, size and population is very vulnerable to the impact of climate change. Little effort is however made to address most of the problems, despite the fact that sufficient understanding is made on the impact of climate change and problems emanating from it are also always being propagated. Migration, one of the resultant effects of climate change is however given less attention. This paper focuses on the climate change impact and one of resulting effects, migration and its associated problems. Purposive sampling technique was adopted in sampling 250 respondents who were mainly family members of out-migrants from Ngala and Kala-Balge LGAs of North-eastern Borno State, Nigeria. Available literatures were consulted for the types of climate change impacts. The results revealed that, climate change leads to climatic variation over the space with numerous effects on the environment such as intermittent droughts, desertification/deforestation, low water table and establishment of dams across the courses of the main sources of water supply to the Lake Chad. Many people in the study area either migrated to Cameroon’s Darrak, Lake Doi and Mayo Mbund, Lagos, Nigeria, leaving some members of their families at home. More than half of respondents indicated that the heads of the households migrated as a result of poor harvest due to diminishing or fluctuating rains/drought and/or drying of river Surbewel. It is recommended that; inter-basin water transfers should be embarked upon.

Keywords: climate, change, migration, dam, intermittent

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10737 Acoustic Radiation from an Infinite Cylindrical Shell with Periodic Lengthwise Ribs

Authors: Yunzhe Tong, Jun Fan, Bin Wang

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The vibroacoustic behavior of an immersed infinite cylindrical shell with periodic lengthwise ribs has been studied in this paper. The motions of the shell are described by the Donnell equations. Each lengthwise rib is modeled as an elastic beam. The motions of the bulkheads are decomposed into the longitudinal motions and flexural motions. The analytical expressions of the shell motions can be obtained through circumferential mode expansion, Fourier Transform and periodic boundary condition in the circumferential direction. Furthermore, the far-field radiated pressure has been obtained using the stationary phase. The analysis of wavenumber domain shows that periodic lengthwise stiffeners in the circumferential direction can produce flexural Bloch waves. The dominant feature in far-field pressure amplitude is the resonance of the supersonic components of the flexural Bloch waves in the circumferential direction.

Keywords: flexural Bloch wave, stiffened shell, vibroacoustics, wavenumber analysis

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10736 To Examine Perceptions and Associations of Shock Food Labelling and to Assess the Impact on Consumer Behaviour: A Quasi-Experimental Approach

Authors: Amy Heaps, Amy Burns, Una McMahon-Beattie

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Shock and fear tactics have been used to encourage consumer behaviour change within the UK regarding lifestyle choices such as smoking and alcohol abuse, yet such measures have not been applied to food labels to encourage healthier purchasing decisions. Obesity levels are continuing to rise within the UK, despite efforts made by government and charitable bodies to encourage consumer behavioural changes, which will have a positive influence on their fat, salt, and sugar intake. We know that taking extreme measures to shock consumers into behavioural changes has worked previously; for example, the anti-smoking television adverts and new standardised cigarette and tobacco packaging have reduced the numbers of the UK adult population who smoke or encouraged those who are currently trying to quit. The USA has also introduced new front-of-pack labelling, which is clear, easy to read, and includes concise health warnings on products high in fat, salt, or sugar. This model has been successful, with consumers reducing purchases of products with these warning labels present. Therefore, investigating if shock labels would have an impact on UK consumer behaviour and purchasing decisions would help to fill the gap within this research field. This study aims to develop an understanding of consumer’s initial responses to shock advertising with an interest in the perceived impact of long-term effect shock advertising on consumer food purchasing decisions, behaviour, and attitudes and will achieve this through a mixed methodological approach taken with a sample size of 25 participants ages ranging from 22 and 60. Within this research, shock mock labels were developed, including a graphic image, health warning, and get-help information. These labels were made for products (available within the UK) with large market shares which were high in either fat, salt, or sugar. The use of online focus groups and mouse-tracking experiments results helped to develop an understanding of consumer’s initial responses to shock advertising with interest in the perceived impact of long-term effect shock advertising on consumer food purchasing decisions, behaviour, and attitudes. Preliminary results have shown that consumers believe that the use of graphic images, combined with a health warning, would encourage consumer behaviour change and influence their purchasing decisions regarding those products which are high in fat, salt and sugar. Preliminary main findings show that graphic mock shock labels may have an impact on consumer behaviour and purchasing decisions, which will, in turn, encourage healthier lifestyles. Focus group results show that 72% of participants indicated that these shock labels would have an impact on their purchasing decisions. During the mouse tracking trials, this increased to 80% of participants, showing that more exposure to shock labels may have a bigger impact on potential consumer behaviour and purchasing decision change. In conclusion, preliminary results indicate that graphic shock labels will impact consumer purchasing decisions. Findings allow for a deeper understanding of initial emotional responses to these graphic labels. However, more research is needed to test the longevity of these labels on consumer purchasing decisions, but this research exercise is demonstrably the foundation for future detailed work.

Keywords: consumer behavior, decision making, labelling legislation, purchasing decisions, shock advertising, shock labelling

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10735 Energy Efficient Shading Strategies for Windows of Hospital ICUs in the Desert

Authors: A. Sherif, A. El Zafarany, R. Arafa

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Hospitals, everywhere, are considered heavy energy consumers. Hospital Intensive Care Unit spaces pose a special challenge, where design guidelines requires the provision of external windows for day-lighting and external view. Window protection strategies could be employed to reduce energy loads without detriment effect on comfort or health care. This paper addresses the effectiveness of using various window strategies on the annual cooling, heating and lighting energy use of a typical Hospital Intensive Unit space. Series of experiments were performed using the EnergyPlus simulation software for a typical Intensive Care Unit (ICU) space in Cairo, located in the Egyptian desert. This study concluded that the use of shading systems is more effective in conserving energy in comparison with glazing of different types, in the Cairo ICUs. The highest energy savings in the West and South orientations were accomplished by external perforated solar screens, followed by overhangs positioned at a protection angle of 45°.

Keywords: energy, hospital, intensive care units, shading

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10734 An Experimental Comparative Study of SI Engine Performance and Emission Characteristics Fuelled with Various Gasoline-Alcohol Blends

Authors: M. Mourad, K. Abdelgawwad

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This experimental investigation aimed to determine the influence of using different types of alcohol and gasoline blends such as ethanol - butanol - propanol on the performance of spark ignition engine. The experimental work studied the effect of various fuel blends such as ethanol – butanol/gasoline and propanol/gasoline with two rates of 15% and 20%, at different operating conditions (engine speed and loads), on engine performance emission characteristics. Laboratory experiments are carried out on a four-cylinder spark ignition (SI) engine. In this practical study, all considerations and precautions are taken into account to ensure the quality and accuracy of practical experiments and different measurements. The results show that the performance of the engine improved significantly in the case of ethanol/butanol-gasoline blends. The results also indicated that the engine emitted pollutants such as CO, hydrocarbon (HC) for alcohol fuel blends compared to base gasoline NOx emission increased for different fuel blends either ethanol/butanol-gasoline or propanol-gasoline fuel blend.

Keywords: gasoline engine, performance, emission, fuel blends

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10733 Impact of Organizational and Individual Antecedents on Employees Empowerment in Nigeria's Hospitality

Authors: Olubunmi Kolawole

Abstract:

This study explored how certain organizational antecedents like work environment, and individual antecedents (e.g. job level and tenure) could affect employees empowerment in the hospitality industry. A total of 200 valid responses from a survey conducted in 10 hotels in Lagos Nigeria were received. Data were analyzed using frequency distribution and percentage analysis. Findings suggest that leadership, work environment, as well as tenure and level in the organization are reliable predictors of employees empowerment in Nigeria's hotel sector. Empowerment is a major factor which determines how employees feel about themselves and their jobs. The study concluded that organizations need to learn that an empowered employee will put in superior performance which would positively impact on the organization.

Keywords: employee empowerment, hospitality industry, individual-level antecedents, leadership, organizational antecedents

Procedia PDF Downloads 487
10732 The Impact of Malicious Attacks on the Performance of Routing Protocols in Mobile Ad-Hoc Networks

Authors: Habib Gorine, Rabia Saleh

Abstract:

Mobile Ad-Hoc Networks are the special type of wireless networks which share common security requirements with other networks such as confidentiality, integrity, authentication, and availability, which need to be addressed in order to secure data transfer through the network. Their routing protocols are vulnerable to various malicious attacks which could have a devastating consequence on data security. In this paper, three types of attacks such as selfish, gray hole, and black hole attacks have been applied to the two most important routing protocols in MANET named dynamic source routing and ad-hoc on demand distance vector in order to analyse and compare the impact of these attacks on the Network performance in terms of throughput, average delay, packet loss, and consumption of energy using NS2 simulator.

Keywords: MANET, wireless networks, routing protocols, malicious attacks, wireless networks simulation

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10731 Parametric Analysis of Water Lily Shaped Split Ring Resonator Loaded Fractal Monopole Antenna for Multiband Applications

Authors: C. Elavarasi, T. Shanmuganantham

Abstract:

A coplanar waveguide (CPW) feed is presented, and comprising a split ring resonator (SRR) loaded fractal with water lily shape is used for multi band applications. The impedance matching of the antenna is determined by the number of Koch curve fractal unit cells. The antenna is designed on a FR4 substrate with a permittivity of εr = 4.4 and size of 14 x 16 x 1.6 mm3 to generate multi resonant mode at 3.8 GHz covering S band, 8.68 GHz at X band, 13.96 GHz at Ku band, and 19.74 GHz at K band with reflection coefficient better than -10 dB. Simulation results show that the antenna exhibits the desired voltage standing wave ratio (VSWR) level and radiation patterns across the wide frequency range. The fundamental parameters of the antenna such as return loss, VSWR, good radiation pattern with reasonable gain across the operating bands are obtained.

Keywords: fractal, metamaterial, split ring resonator, waterlily shape

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10730 Friction and Wear Characteristics of Pongamia Oil Based Blended Lubricant at Different Load and Sliding Distance

Authors: Yashvir Singh

Abstract:

Around the globe, there is demand for the development of bio-based lubricant which will be biodegradable, non -toxic and environmental friendly. This paper outlines the friction and wear characteristics of Pongamia oil (PO) contaminated bio-lubricant by using pin-on-disc tribometer. To formulate the bio-lubricants, PO was blended in the ratios 15, 30 and 50% by volume with the base lubricant SAE 20 W 40. Tribological characteristics of these blends were carried out at 3.8 m/s sliding velocity and loads applied were 50, 100, 150 N. Experimental results showed that the lubrication regime that occurred during the test was boundary lubrication while the main wear mechanisms were abrasive and the adhesive wear. During testing, the lowest wear was found with the addition of 15% PO, and above this contamination, the wear rate was increased considerably. With increase in load, viscosity of all the bio-lubricants increases and meets the ISO VG 100 requirement at 40 oC except PB 50. The addition of PO in the base lubricant acted as a very good lubricant additive which reduced the friction and wear scar diameter during the test. It has been concluded that the PB 15 can act as an alternative lubricant to increase the mechanical efficiency at 3.8 m/s sliding velocity and contribute in reduction of dependence on the petroleum based products.

Keywords: friction, load, pongamia oil, sliding velocity, wear

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10729 Corporate Governance and Corporate Social Responsibility: Research on the Interconnection of Both Concepts and Its Impact on Non-Profit Organizations

Authors: Helene Eller

Abstract:

The aim of non-profit organizations (NPO) is to provide services and goods for its clientele, with profit being a minor objective. By having this definition as the basic purpose of doing business, it is obvious that the goal of an organisation is to serve several bottom lines and not only the financial one. This approach is underpinned by the non-distribution constraint which means that NPO are allowed to make profits to a certain extent, but not to distribute them. The advantage is that there are no single shareholders who might have an interest in the prosperity of the organisation: there is no pie to divide. The gained profits remain within the organisation and will be reinvested in purposeful projects. Good governance is mandatory to support the aim of NPOs. Looking for a measure of good governance the principals of corporate governance (CG) will come in mind. The purpose of CG is direction and control, and in the field of NPO, CG is enlarged to consider the relationship to all important stakeholders who have an impact on the organisation. The recognition of more relevant parties than the shareholder is the link to corporate social responsibility (CSR). It supports a broader view of the bottom line: It is no longer enough to know how profits are used but rather how they are made. Besides, CSR addresses the responsibility of organisations for their impact on society. When transferring the concept of CSR to the non-profit area it will become obvious that CSR with its distinctive features will match the aims of NPOs. As a consequence, NPOs who apply CG apply also CSR to a certain extent. The research is designed as a comprehensive theoretical and empirical analysis. First, the investigation focuses on the theoretical basis of both concepts. Second, the similarities and differences are outlined and as a result the interconnection of both concepts will show up. The contribution of this research is manifold: The interconnection of both concepts when applied to NPOs has not got any attention in science yet. CSR and governance as integrated concept provides a lot of advantages for NPOs compared to for-profit organisations which are in a steady justification to show the impact they might have on the society. NPOs, however, integrate economic and social aspects as starting point. For NPOs CG is not a mere concept of compliance but rather an enhanced concept integrating a lot of aspects of CSR. There is no “either-nor” between the concepts for NPOs.

Keywords: business ethics, corporate governance, corporate social responsibility, non-profit organisations

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10728 Migrant Workers and the Challenge for Human Security in Southeast Asia since 1997

Authors: Hanen Khaldi

Abstract:

This paper aims to study the impact of international migration on human security in the Southeastern region of Asia, especially after Asian Financial Crisis 1997-98. International migration has impacts on many dimensions of security: the state security (sovereignty and autonomy); international relationships security (conflicts, terrorism, etc); and immigrants security. The paper aims to improve our comprehension of the impact of international migration on immigrant security in the region of Southeast Asia, particularly “vulnerable workers’’ whose number is growing very fast in the region. The literature review carried out on this matter led us to ask the following two question: 1) Did the creation of ASEAN Community matter on the evolution of immigrants in the region? And How governments try to resolve the gap between economic objectifs and security of immigrants in the region? To answer these two questions, the paper is subdivided in three parts: Firstly, we will show how the creation of the ASEAN Community, especially ASEAN Economic Community, had a significant impact on the pattern of evolution of immigration in this region. Secondly, we will paint a portrait illustrating the vulnerability of immigrants in Southeast Asia, particularly unskilled workers. Finally, using the theories of regional integration, we will assess how governments try to ensure the security and safety of the immigrants. Overall, our analysis illustrate the significant change of the official discourse of the leaders of the ASEAN member states, now more conciliator and especially more open to cooperation, as well as the proliferation of meetings and initiatives between these countries to control mobility flows in the region, and the ensure immigrants security.

Keywords: migrant workers, human security, human rights

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10727 Multi-Disciplinary Optimisation Methodology for Aircraft Load Prediction

Authors: Sudhir Kumar Tiwari

Abstract:

The paper demonstrates a methodology that can be used at an early design stage of any conventional aircraft. This research activity assesses the feasibility derivation of methodology for aircraft loads estimation during the various phases of design for a transport category aircraft by utilizing potential of using commercial finite element analysis software, which may drive significant time saving. Early Design phase have limited data and quick changing configuration results in handling of large number of load cases. It is useful to idealize the aircraft as a connection of beams, which can be very accurately modelled using finite element analysis (beam elements). This research explores the correct approach towards idealizing an aircraft using beam elements. FEM Techniques like inertia relief were studied for implementation during course of work. The correct boundary condition technique envisaged for generation of shear force, bending moment and torque diagrams for the aircraft. The possible applications of this approach are the aircraft design process, which have been investigated.

Keywords: multi-disciplinary optimization, aircraft load, finite element analysis, stick model

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10726 The Influence of Ice Topography on Sliding over Ice

Authors: Ernests Jansons, Karlis Agris Gross

Abstract:

Winter brings snow and ice in the Northern Europe and with it the need to move safely over ice. It has been customary to select an appropriate material surface for movement over ice, but another way to influence the interaction with ice is to modify the ice surface. The objective of this work was to investigate the influence of ice topography on initiating movement over ice and on sliding velocity over ice in the laboratory and real-life conditions. The ice was prepared smooth, scratched or with solidified ice-droplets to represent the surface of ice after ice rain. In the laboratory, the coefficient of friction and the sliding velocity were measured, but the sliding velocity measured at the skeleton push-start facility. The scratched ice surface increased the resistance to movement and also showed the slowest sliding speed. Sliding was easier on the smooth ice and ice covered with frozen droplets. The contact surface was measured to determine the effect of contact area with sliding. Results from laboratory tests will be compared to loading under heavier loads to show the influence of load on sliding over different ice surfaces. This outcome provides a useful indicator for pedestrians and road traffic on the safety of movement over different ice surfaces as well as a reference for those involved with winter sports.

Keywords: contact area, friction, ice topography, sliding velocity

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10725 Investigation of Mechanical Properties of Epoxy-Nanocomposite Reinforced with Copper Coated MWCNTs

Authors: M. Nazem Salimi, C. Abrinia, M. Baniassadi, M. Ehsani

Abstract:

Mechanical properties of epoxy based nanocomposites containing copper coated MWCNTs were investigated and a comparative study between nanocomposites containing functionalized MWCNTs and copper coated MWCNTs which are already functionalized was conducted. The MWCNTs was deposited with copper nanoparticles through electroless deposition process after accomplishment of "two-step" method as sensitization and activation procedures on oxidized MWCNTs. In addition, functionalization of MWCNTs was carried out through combination of two covalent and non-covalent funcionalization methods using HNO3 for acid solution of covalent treatment and Triton X100 as non-ionic surfactant of non-covalent treatment. The presence of functional groups and removal of impurities of MWCNTs were confirmed by FTIR and Raman spectroscopy, respectively. The layer of copper nanoparticles on the MWCNTs wall increasing its diameter was observed by SEM. Utilizing solution blending process, 0.1%, 0.5% and 1.5% wt loading of both copper coated MWCNTs and non-coated MWCNTs were used to prepare epoxy-based nanocomposites. The tensile, flexural and impact properties of nanocomposites were investigated. The results of tensile test demonstrated that nanocomposites containing copper coated MWCNTs exhibited brittle behavior compared to those reinforced with functionalized MWCNTs, whereas former one exhibited higher values of modulus than latter one for concentrations more than 0.4% wt. Presence of copper particles on MWCNTs surface decreased the tensile strength of nanocomposites. In comparison to pure epoxy, nanocomposites with treated-MWCNTs and Cu-MWCNTs loading of 0.1% wt showed an increase of 35% and 51.6% for flexural strength beside 20% and 30% increase in flexural modulus, respectively, whereas flexural properties of both naocomposites decreased with increasing of CNTs concentration. The results of impact strength of nanocomposites with Cu-CNTs demonstrated that impact properties decreased with increasing of filler content with a optimum value at 0.1% wt while in high concentrations impact properties of Cu-nanocomposites exhibited lower values than f-MWCNT nanocomposites.

Keywords: epoxyresin, nanocomposite, functionalization, copper, electroless deposition process, mechanical properties

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10724 Seismic Performance of RC Frames Equipped with Friction Panels Under Different Slip Load Distributions

Authors: Neda Nabid, Iman Hajirasouliha, Sanaz Shirinbar

Abstract:

One of the most challenging issues in earthquake engineering is to find effective ways to reduce earthquake forces and damage to structural and non-structural elements under strong earthquakes. While friction dampers are the most efficient systems to improve the seismic performance of substandard structures, their optimum design is a challenging task. This research aims to find more appropriate slip load distribution pattern for efficient design of friction panels. Non-linear dynamic analyses are performed on 3, 5, 10, 15, and 20-story RC frame using Drain-2dx software to find the appropriate range of slip loads and investigate the effects of different distribution patterns (cantilever, uniform, triangle, and reverse triangle) under six different earthquake records. The results indicate that using triangle load distribution can significantly increase the energy dissipation capacity of the frame and reduce the maximum inter-storey drift, and roof displacement.

Keywords: friction panels, slip load, distribution patterns, RC frames, energy dissipation

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10723 Quantitative Analysis of Contract Variations Impact on Infrastructure Project Performance

Authors: Soheila Sadeghi

Abstract:

Infrastructure projects often encounter contract variations that can significantly deviate from the original tender estimates, leading to cost overruns, schedule delays, and financial implications. This research aims to quantitatively assess the impact of changes in contract variations on project performance by conducting an in-depth analysis of a comprehensive dataset from the Regional Airport Car Park project. The dataset includes tender budget, contract quantities, rates, claims, and revenue data, providing a unique opportunity to investigate the effects of variations on project outcomes. The study focuses on 21 specific variations identified in the dataset, which represent changes or additions to the project scope. The research methodology involves establishing a baseline for the project's planned cost and scope by examining the tender budget and contract quantities. Each variation is then analyzed in detail, comparing the actual quantities and rates against the tender estimates to determine their impact on project cost and schedule. The claims data is utilized to track the progress of work and identify deviations from the planned schedule. The study employs statistical analysis using R to examine the dataset, including tender budget, contract quantities, rates, claims, and revenue data. Time series analysis is applied to the claims data to track progress and detect variations from the planned schedule. Regression analysis is utilized to investigate the relationship between variations and project performance indicators, such as cost overruns and schedule delays. The research findings highlight the significance of effective variation management in construction projects. The analysis reveals that variations can have a substantial impact on project cost, schedule, and financial outcomes. The study identifies specific variations that had the most significant influence on the Regional Airport Car Park project's performance, such as PV03 (additional fill, road base gravel, spray seal, and asphalt), PV06 (extension to the commercial car park), and PV07 (additional box out and general fill). These variations contributed to increased costs, schedule delays, and changes in the project's revenue profile. The study also examines the effectiveness of project management practices in managing variations and mitigating their impact. The research suggests that proactive risk management, thorough scope definition, and effective communication among project stakeholders can help minimize the negative consequences of variations. The findings emphasize the importance of establishing clear procedures for identifying, assessing, and managing variations throughout the project lifecycle. The outcomes of this research contribute to the body of knowledge in construction project management by demonstrating the value of analyzing tender, contract, claims, and revenue data in variation impact assessment. However, the research acknowledges the limitations imposed by the dataset, particularly the absence of detailed contract and tender documents. This constraint restricts the depth of analysis possible in investigating the root causes and full extent of variations' impact on the project. Future research could build upon this study by incorporating more comprehensive data sources to further explore the dynamics of variations in construction projects.

Keywords: contract variation impact, quantitative analysis, project performance, claims analysis

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