Search results for: large scale calorimeter

Authors: Jonny Beirne

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Hydropower developments have come to assume an important role within the Ethiopian government's overall development strategy for the country during the last ten years. The Gilgel Gibe III on the Omo river, due to become operational in September 2014, represents the most ambitious, and controversial, of these projects to date. Further aspects of the government's national development strategy include leasing vast areas of designated 'unused' land for large-scale commercial agricultural projects and 'voluntarily' villagizing scattered, semi-nomadic agro-pastoralist groups to centralized settlements so as to use land and water more efficiently and to better provide essential social services such as education and healthcare. The Lower Omo valley, along the Omo River, is one of the sites of this villagization programme as well as of these large-scale commercial agricultural projects which are made possible owing to the regulation of the river's flow by Gibe III. Though the Ethiopian government cite many positive aspects of these agricultural and hydropower developments there are still expected to be serious regional and transnational effects, including on migration flows, in an area already characterized by increasing climatic vulnerability with attendant population movements and conflicts over scarce resources. The following paper is an attempt to track actual and anticipated migration flows resulting from the construction of Gibe III in the immediate vicinity of the dam, downstream in the Lower Omo Valley and across the border in Kenya around Lake Turkana. In the case of those displaced in the Lower Omo Valley, this will be considered in view of the distinction between voluntary villagization and forced resettlement. The research presented is not primary-source material. Instead, it is drawn from the reports and assessments of the Ethiopian government, rights-based groups, and academic researchers as well as media articles. It is hoped that this will serve to draw greater attention to the issue and encourage further methodological research on the dynamics of dam constructions (and associated large-scale irrigation schemes) on migration flows and on the ultimate experience of displacement and resettlement for environmental migrants in the region.

Keywords: forced displacement, voluntary resettlement, migration, human rights, human security, land grabs, dams, commercial agriculture, pastoralism, ecosystem modification, natural resource conflict, livelihoods, development

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Authors: Maria Pintea, Nigel Mason

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Induced chemistry is one of the newest pathways in the nanotechnology field with applications in the focused electron beam induced processes for deposition of nm scale structures. Si(OPr)₄ and Ti(OEt)₄ are two of the precursors that have not been so extensively researched, though highly sought for semiconductor and medical applications fields, the two compounds make good candidates for FEBIP and are the subject of velocity slice map imaging analysis for deposition purposes, offering information on kinetic energies, fragmentation channels, and angular distributions. The velocity slice map imaging technique is a method used for the characterization of molecular dynamics of the molecule and the fragmentation channels as a result of induced chemistry. To support the gas-phase analysis, Meso-Bio-Nano simulations of irradiation dynamics studies are employed with final results on Fe(CO)₅ deposited on various substrates. The software is capable of running large scale simulations for complex biomolecular, nano- and mesoscopic systems with applications to thermos-mechanical DNA damage, complex materials, gases, nanoparticles for cancer research and deposition applications for nanotechnology, using a large library of classical potentials, many-body force fields, molecular force fields involved in the classical molecular dynamics.

Keywords: focused electron beam induced deposition, FEBID, induced chemistry, molecular dynamics, velocity map slice imaging

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Authors: Matthew T. McCarthy, Sarah Janse, Natalie M. Pizzimenti, Anthony K. Savino, Brian Crosser, Sean C. Rose

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Concussion is diagnosed clinically using a comprehensive history and exam, supported by ancillary testing. Frequently, symptom checklists are used as part of the evaluation of concussion. Existing symptom scales are based on a subjective Likert scale, without relation of symptoms to clinical or functional impairment. This is a retrospective review of 133 patients under age 30 seen in an outpatient neurology practice within 30 days of a probable or definite concussion. Each patient completed 2 symptom checklists at the initial visit – the SCAT-3 symptom evaluation (22 symptoms, 0-6 scale) and a scale based on the degree of clinical impairment for each symptom (22 symptoms, 0-3 scale related to functional impact of the symptom). Final clearance date was determined by the treating physician. 60.9% of patients were male with mean age 15.7 years (SD 2.3). Mean time from concussion to first visit was 6.9 days (SD 6.2), and 101 patients had definite concussions (75.9%), while 32 were diagnosed as probable (24.1%). 94 patients had a known clearance date (70.7%) with mean clearance time of 20.6 days (SD 18.6) and median clearance time of 19 days (95% CI 16-21). Mean total symptom score was 27.2 (SD 22.9) on the SCAT-3 and 14.7 (SD 11.9) for the functional impairment scale. Pearson’s correlation between the two scales was 0.98 (p < 0.001). After adjusting for patient and injury characteristics, an equivalent increase in score on each scale was associated with longer time to clearance (SCAT-3 hazard ratio 0.885, 95%CI 0.835-0.938, p < 0.001; functional impairment scale hazard ratio 0.851, 95%CI 0.802-0.902, p < 0.001). A concussion symptom scale based on degree of functional impairment correlates strongly with the SCAT-3 scale and demonstrates a similar association with time to clearance. By assessing the degree of impact on clinical functioning, this symptom scale reflects a more intuitive approach to rating symptoms and can be used in the management of concussion.

Keywords: checklist, concussion, neurology, scale, sports, symptoms

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Authors: Meril Kate Mariano, Billy Joel Almarinez Divina Amalin, Jose Isagani Janairo

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The scale insects Aspidiotus destructor and Aspidiotus rigidus exhibit notable scale covers made of wax which provides protection against water loss and is capable to resist wetting, thus making them a desirable model for biomimetic designs. Their waxy covers enable them to infest mainly leaves of coconut trees despite the harsh wind and rain. This study aims to describe and compare the micro morphological characters on the surfaces of their scale covers consequently, how these micro structures affect their wetting properties. Scanning electron microscope was used for the surface characterization while an optical contact angle meter was employed in the wetting measurement. The scale cover of A. destructor is composed of multiple overlapping layers of wax that is arranged regularly while that of A. rigidus is composed of a uniform layer of wax with much more prominent wax ribbons irregularly arranged compared to the former. The protrusions found on the two organisms are formed by the wax ribbons that differ in arrangement with their height being A. destructor (3.57+1.29) < A. rigidus (4.23+1.22) and their density A. destructor (15+2.94) < A. rigidus (18.33+2.64). These morphological measurements could affect the contact angle (CA θ) measurement of A. destructor (102.66+9.78°) < A. rigidus (102.77 + 11.01°) wherein the assessment that the interaction of the liquid to the microstructures of the substrate is a large factor in the wetting properties of the insect scales is realized. The calculated surface free energy of A. destructor (38.47 mJ/m²) > A. rigidus (31.02 mJ/m²) shows inverse proportionality with the CA measurement. The dispersive interaction between the surface and liquid is more prevalent compared to the polar interaction for both Aspidiotus species, which was observed using the Fowkes method. The results of this study have possible applications to be a potential biomimetic design for various industries such as textiles and coatings.

Keywords: Aspidiotus spp., biomimetics, contact angle, surface characterization, wetting behavior

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Authors: I. Dangeard, S. Meineri, M. Dupré

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large body of research on energy consumption reveals that regular information on energy consumption produces a positive effect on behavior. The present research aims to test this feedback paradigm on waste management. A small-scale experiment on residual household waste was performed in a large french urban area, in partnership with local authorities, as part of the development of larger-scale project. A two-step door-to-door recruitment scheme led to 85 households answering a questionnaire. Among them, 54 accepted to participate in a study on waste (second step). Participants were then randomly assigned to one of the 3 experimental conditions : self-reported feedback on curbside waste, external feedback on waste weight based on information technologies, and no feedback for the control group. An additional control group was added, including households who were not requested to answer the questionnaire. Household residual waste was collected every week, and tags on curbside bins fed a database with waste weight of households. The feedback period lasted 14 weeks (february-may 2014). Quantitative data on waste weight were analysed, including these 14 weeks and the 7 previous weeks. Households were then contacted by phone in order to confirm the quantitative results. Regarding the recruitment questionnaire, results revealed high pro-environmental attitude on the NEP scale, high recycling behavior level and moderate level of source reduction behavior on the adapted 3R scale, but no statistical difference between the 3 experimental groups. Regarding the feedback manipulation paradigm, waste weight reveals important differences between households, but doesn't prove any statistical difference between the experimental conditions. Qualitative phone interviews confirm that recycling is a current practice among participants, whereas source reduction of waste is not, and mainly appears as a producer problem of packaging limitation. We conclude that triggering waste prevention behaviors among recycling households involves long-term feedback and should promote benchmarking, in order to clearly set waste reduction as an objective to be managed through feedback figures.

Keywords: eco-feedback, household waste, waste reduction, experimental research

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Authors: Ijaz Ul Haq, Fiorenzo Franceschini

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The distributed manufacturing methodology brings a new concept of decentralized manufacturing operations close to the proximity of end users. A preliminary scale, to measure distributed capacity and evaluate positioning of firms, is developed in this research. In the first part of the paper, a literature review has been performed which highlights the explorative nature of the studies conducted to present definitions and classifications due to novelty of this topic. From literature, five dimensions of distributed manufacturing development stages have been identified: localization, manufacturing technologies, customization and personalization, digitalization and democratization of design. Based on these determinants a conceptual scale is proposed to measure the status of distributed manufacturing of a generic firm. A multiple case study is then conducted in two steps to test the conceptual scale and to identify the corresponding level of distributed potential in each case study firm.

Keywords: distributed manufacturing, distributed capacity, localized production, ordinal scale

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Authors: Yiannis Koumpouros, Effie Papageorgiou, Alexandra Karavasili, Foteini Koureta

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The objective of the present study was to develop a scale called PYTHEIA. The PYTHEIA is a self-reported measure for the assessment of rehabilitation and assistive robotics and other assistive technology devices. The development of PYTHEIA faced the absence of a valid instrument that can be used to evaluate the assistive robotic devices both as a whole, as well as any of their individual components or functionalities implemented. According to the results presented, PYTHEIA is a valid and reliable scale able to be applied to different target groups for the subjective evaluation of various assistive technology devices.

Keywords: rehabilitation, assistive technology, assistive robots, rehabilitation robots, scale, psychometric test, assessment, validation, user satisfaction

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Authors: Gee-Cheol Kim, Joo-Won Kang

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Structural characteristics of spatial structure are different from that of rahmen structures and it has many factors that are unpredictable experientially. Both horizontal and vertical earthquake should be considered because of seismic behaviour characteristics of spatial structures. This experimental study is conducted about seismic response characteristics of roof structure according to the effect of columns or walls, through scale model of arch structure that has the basic dynamic characteristics of spatial structure. Though remarkable response is not occurred for horizontal direction in the region of higher frequency than the region of frequency that seismic energy is concentrated, relatively large response is occurred in vertical direction. It is proved that seismic response of arch structure with column is varied according to property of column.

Keywords: arch structure, seismic response, shaking table, spatial structure

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Authors: Ahmed El Naggar, Homyan Saleh

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Dams are crucial for flood control, water supply, and the creation of hydroelectric power. Every dam has a water conveyance system, such as a spillway, providing the safe discharge of catastrophic floods when necessary. Spillway design has historically been investigated in laboratory research owing to the absence of suitable full-scale flow monitoring equipment and safety problems. Prototype measurements of aerated flows are urgently needed to quantify projected scale effects and provide missing validation data for design guidelines and numerical simulations. In this work, an image-based investigation of free-surface flows on a tiered spillway was undertaken at the laboratory (fixed camera installation) and prototype size (drone video) (drone footage) (drone footage). The drone videos were generated using data from citizen science. Analyses permitted the measurement of the free-surface aeration inception point, air-water surface velocities, fluctuations, and residual energy at the chute's downstream end from a remote site. The prototype observations offered full-scale proof of concept, while laboratory results were efficiently confirmed against invasive phase-detection probe data. This paper stresses the efficacy of image-based analyses at prototype spillways. It highlights how citizen science data may enable academics better understand real-world air-water flow dynamics and offers a framework for a small collection of long-missing prototype data.

Keywords: remote sensing, aerated flows, large dams, proof of concept, dam spillways, air-water flows, prototype operation, remote sensing, inception point, optical flow, turbulence, residual energy

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Authors: Q. Giraud, J. Gonçalvès, B. Paris

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Remediation of dense non-aqueous phase liquids (DNAPLs) represents a challenging issue because of their persistent behaviour in the environment. This pilot-scale study investigates, by means of in situ experiments and numerical modelling, the feasibility of the pulsed pumping process of a large amount of a DNAPL in an alluvial aquifer. The main compound of the DNAPL is hexachlorobutadiene, an emerging organic pollutant. A low-permeability keyed enclosure was built at the location of the DNAPL source zone in order to isolate a finite undisturbed volume of soil, and a 3-month pulsed pumping process was applied inside the enclosure to exclusively extract the DNAPL. The water/DNAPL interface elevation at both the pumping and observation wells and the cumulated pumped volume of DNAPL were also recorded. A total volume of about 20m³ of purely DNAPL was recovered since no water was extracted during the process. The three-dimensional and multiphase flow simulator TMVOC was used, and a conceptual model was elaborated and generated with the pre/post-processing tool mView. Numerical model consisted of 10 layers of variable thickness and 5060 grid cells. Numerical simulations reproduce the pulsed pumping process and show an excellent match between simulated, and field data of DNAPL cumulated pumped volume and a reasonable agreement between modelled and observed data for the evolution of the water/DNAPL interface elevations at the two wells. This study offers a new perspective in remediation since DNAPL pumping system optimisation may be performed where a large amount of DNAPL is encountered.

Keywords: dense non-aqueous phase liquid (DNAPL), hexachlorobutadiene, in situ pulsed pumping, multiphase flow, numerical modelling, porous media

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Authors: Avinoam Rabinovich

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CO₂ geological storage is a proven technology for reducing anthropogenic carbon emissions, which is paramount for achieving the ambitious net zero emissions goal. Core flooding experiments are an important step in any CO₂ storage project, allowing us to gain information on the flow of CO₂ and brine in the porous rock extracted from the reservoir. This information is important for understanding basic mechanisms related to CO₂ geological storage as well as for reservoir modeling, which is an integral part of a field project. In this work, a different method for constructing accurate models of CO₂-brine core flooding will be presented. Results for synthetic cases and real experiments will be shown and compared with numerical models to exhibit their predictive capabilities. Furthermore, the various mechanisms which impact the CO₂ distribution and trapping in the rock samples will be discussed, and examples from models and experiments will be provided. The new method entails solving an inverse problem to obtain a three-dimensional permeability distribution which, along with the relative permeability and capillary pressure functions, constitutes a model of the flow experiments. The model is more accurate when data from a number of experiments are combined to solve the inverse problem. This model can then be used to test various other injection flow rates and fluid fractions which have not been tested in experiments. The models can also be used to bridge the gap between small-scale capillary heterogeneity effects (sub-core and core scale) and large-scale (reservoir scale) effects, known as the upscaling problem.

Keywords: CO₂ geological storage, residual trapping, capillary heterogeneity, core flooding, CO₂-brine flow

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Authors: Sohail Zafar, Sardar Javaid Iqbal Khan

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We use a parametric approach within a translog cost function framework to estimate the economies of scale in National Bank of Pakistan from 1997 to 2013. The results indicate significant economies of scale throughout the sample at aggregates and disaggregates taking in account size subject to stipulation ownership. The factor markets often produce scale inefficiencies in the banking of developing countries like Pakistan such inefficiencies are common due to distortion in factor markets leading to the use of inappropriate factor proportions. The findings suggest that National Bank of Pakistan diversify their asset portfolios that it has cost advantage, therefore, expansion in size should be encouraged under current technology because it appears to be cost effective. In addition, our findings support the implementation of universal banking model in Pakistan.

Keywords: scale economies, cost function, disaggregates, aggregates

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Authors: Vishal Kumar Singh

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Bioprocess development is a time-constrained activity aimed at harnessing the full potential of culture performance in an ambience that is not natural to cells. Even with the use of chemically defined media and feeds, a significant amount of time is devoted in identifying the apt operating parameters. In addition, the scale-up of these processes is often accompanied by loss of antibody titer and product quality, which further delays the commercialization of the drug product. In such a scenario, the investigation of this disparity of culture performance is done by further experimentation at a smaller scale that is representative of at-scale production bioreactors. These scale-down model developments are also time-intensive. In this study, a computation fluid dynamics-based multi-objective scaling approach has been illustrated to speed up the process transfer. For the implementation of this approach, a transient multiphase water-air system has been studied in Ansys CFX to visualize the air bubble distribution and volumetric mass transfer coefficient (kLa) profiles, followed by the design of experiment based parametric optimization approach to define the operational space. The proposed approach is completely in silico and requires minimum experimentation, thereby rendering a high throughput to the overall process development.

Keywords: bioprocess development, scale up, scale down, computation fluid dynamics, multi-objective, Ansys CFX, design of experiment

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Authors: Intesar Ibrahim

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Large-scale Libyan emigration is a relatively new phenomenon. Most of the Libyan families in the UK are new immigrants, unlike the other neighbouring countries of Egypt, Tunisia, Algeria and even Sudan. Libyans have no particular history of large-scale migration. On the other hand, many Libyan families live in modest homes located in large Muslim communities of Pakistanis and Yemenis. In the UK as a whole, there are currently 16 Libyan schools most of which are run during the weekend for children of school age. There are three such weekend schools in Sheffield that teach a Libyan school curriculum, and Libyan women and men run these schools. Further, there is also a Masjid (mosque) that is operated by Libyans, beside the other Masjids in the city, which most of the Libyan community attend for prayer and for other activities such as writing marriage contracts. The presence of this Masjid increases the attraction for Libyans to reside in the Sheffield area. This paper studies how Libyan immigrants in the UK make their decisions on their housing and living environment in the UK. Libyan residents in the UK come from different Libyan regions, social classes and lifestyles; this may have an impact on their choices in the interior designs of their houses in the UK. A number of case studies were chosen from Libyan immigrants who came from different types of dwellings in Libya, in order to compare with their homes and their community lifestyle in the UK and those in Libya. This study explores the meaning and the ways of using living rooms in Libyan emigrants’ houses in the UK and compares those with those in their houses back in their home country. For example, the way they set up furniture in rooms acts as an indicator of the hierarchical structure of society. The design of furniture for Libyan sitting rooms for floor-seating is different from that of the traditional English sitting room. The paper explores the identity and cultural differences that affected the style and design of the living rooms for Libyan immigrants in the UK. The study is carried out based on the "production of space" theory that any culture has its needs, style of living and way of thinking. I argue that the study found more than 70% of Libyan immigrants in the UK still furnish the living room in their traditional way (flooring seating).

Keywords: place, identity, culture, immigrants

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Authors: Sarra Haouala, Issam Doghri

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In this work, a multiscale computational strategy is proposed for the analysis of structures, which are described at a refined level both in space and in time. The proposal is applied to two-phase viscoelastic-viscoplastic (VE-VP) reinforced thermoplastics subjected to large numbers of cycles. The main aim is to predict the effective long time response while reducing the computational cost considerably. The proposed computational framework is a combination of the mean-field space homogenization based on the generalized incrementally affine formulation for VE-VP composites, and the asymptotic time homogenization approach for coupled isotropic VE-VP homogeneous solids under large numbers of cycles. The time homogenization method is based on the definition of micro and macro-chronological time scales, and on asymptotic expansions of the unknown variables. First, the original anisotropic VE-VP initial-boundary value problem of the composite material is decomposed into coupled micro-chronological (fast time scale) and macro-chronological (slow time-scale) problems. The former is purely VE, and solved once for each macro time step, whereas the latter problem is nonlinear and solved iteratively using fully implicit time integration. Second, mean-field space homogenization is used for both micro and macro-chronological problems to determine the micro and macro-chronological effective behavior of the composite material. The response of the matrix material is VE-VP with J2 flow theory assuming small strains. The formulation exploits the return-mapping algorithm for the J2 model, with its two steps: viscoelastic predictor and plastic corrections. The proposal is implemented for an extended Mori-Tanaka scheme, and verified against finite element simulations of representative volume elements, for a number of polymer composite materials subjected to large numbers of cycles.

Keywords: asymptotic expansions, cyclic loadings, inclusion-reinforced thermoplastics, mean-field homogenization, time homogenization

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Authors: Shashank Tiwari, S. P. Mahapatra

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The aim of this technique is to reduce the steps of process scales up, save time & cost of the industries. This technique will minimise the steps of process scale up. The new steps are, Novel Lab Scale, Novel Lab Scale Trials, Novel Trial Batches, Novel Exhibit Batches, Novel Validation Batches. In these steps, it is not divided to validation batches in three parts but the data of trials batches, Exhibit Batches and Validation batches are use and compile for production and used for validation. It also increases the batch size of the trial, exhibit batches. The new size of trials batches is not less than fifty Thousand, the exhibit batches increase up to two lack and the validation batches up to five lack. After preparing the batches all their data & drugs use for stability & maintain the validation record and compile data for the technology transfer in production department for preparing the marketed size batches.

Keywords: batches, technique, preparation, scale up, validation

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Authors: Melissa Teo

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It is increasingly important that project managers develop greater capabilities to better manage the social, cultural, political, environmental and economic impacts on proposed construction projects. These challenges are best resolved in consultation with communities rather than in conflict with them. This is particularly important on controversial projects which are projects that have obtained government sanctioned ‘development approval’ but not ‘community approval’. While a rich body of research and intellectual frameworks exist in the fields of urban geography and planning to understand and manage community concerns during the pre-development approval stages of new projects, current theoretical frameworks guiding community engagement in project management are inadequate. A new and innovative research agenda is needed to guide thinking about the role of local communities in the construction process and is an important research gap that needs to be filled. Within this context, this research aims to assess the effectiveness of strategies adopted by project teams to engage with local communities so as to capture lessons learnt to apply to future projects. This paper reports a research methodology which uses Arnstein’s model of participation to better understand how power differentials between the project team and local communities can influence the adoption of community engagement strategies. A case study approach is utilizing interviews and documentary analysis of a large-scale controversial construction project in Queensland, Australia is presented. The findings will result in a number of recommendations to guide community engagement practices on future projects.

Keywords: community engagement, construction, case study, project management

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Authors: Yitao Lei, Xingxiang Zhai, Burra Venkata Durga Kumar

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As the quantity and complexity of computing in large-scale software systems increase, distributed system computing becomes increasingly important. The distributed system realizes high-performance computing by collaboration between different computing resources. If there are no efficient resource scheduling resources, the abuse of distributed computing may cause resource waste and high costs. However, resource scheduling is usually an NP-hard problem, so we cannot find a general solution. However, some optimization algorithms exist like genetic algorithm, ant colony optimization, etc. The large scale of distributed systems makes this traditional optimization algorithm challenging to work with. Heuristic and machine learning algorithms are usually applied in this situation to ease the computing load. As a result, we do a review of traditional resource scheduling optimization algorithms and try to introduce a deep reinforcement learning method that utilizes the perceptual ability of neural networks and the decision-making ability of reinforcement learning. Using the machine learning method, we try to find important factors that influence the performance of distributed system computing and help the distributed system do an efficient computing resource scheduling. This paper surveys the application of deep reinforcement learning on distributed system computing resource scheduling proposes a deep reinforcement learning method that uses a recurrent neural network to optimize the resource scheduling, and proposes the challenges and improvement directions for DRL-based resource scheduling algorithms.

Keywords: resource scheduling, deep reinforcement learning, distributed system, artificial intelligence

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Authors: Talal S. Abdullah, Shahin Mehraban, Geraint Lodwig, Nicholas P. Lavery

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The defining property of Interstitial Free (IF) steels is formability, comprehensively measured using the Lankford coefficient (r-value) on uniaxial tensile test data. The contributing factors supporting this feature are grain size, orientation, and elemental additions. The processes that effectively modulate these factors are the casting procedure, hot rolling, and heat treatment. An existing methodology is well-practised in the steel Industry; however, large-scale production and experimentation consume significant proportions of time, money, and material. Introducing small-scale rapid alloy prototyping (RAP) as an alternative process would considerably reduce the drawbacks relative to standard practices. The aim is to finetune the existing fundamental procedures implemented in the industrial plant to adapt to the RAP route. IF material is remelted in the 80-gram coil induction melting (CIM) glovebox. To birth small grains, maximum deformation must be induced onto the cast material during the hot rolling process. The rolled strip must then satisfy the polycrystalline behaviour of the bulk material by displaying a resemblance in microstructure, hardness, and formability to that of the literature and actual plant steel. A successful outcome of this work is that small-scale RAP can achieve target compositions with similar microstructures and statistically consistent mechanical properties which complements and accelerates the development of novel steel grades.

Keywords: rapid alloy prototyping, plastic anisotropy, interstitial free, miniaturised tensile testing, formability

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Authors: Kenneth Azaigba

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The history of post-colonial African States has been dubbed a history of endemic warfare in existing literature. Indeed, Africa political environment is characterized by a multiplicity of threats to peace and security. Africa's leading drivers of conflict include abundant (especially mineral) resources, personal rule and attendant political authoritarianism, manipulation of identity politics across ethnicity, marginalization of communities, as well as electoral mal-practices resulting in contested legitimacy and resultant violence. However, the character of armed conflicts in Africa is changing. This paper attempts to reconstruct the trajectory of armed conflicts in Africa and explain the changing pattern of armed conflict. The paper contends that large scale political violence in Africa is on the decline rendering the endemic thesis an inappropriate paradigm in explaining political conflicts in Africa. The paper also posits that though small scale conflicts are springing up and exhibiting trans-border dimensions, these patterns of armed conflicts are not peculiar to Africa but emerging waves of global conflicts. The paper explains that the shift in the scale of warfare in Africa is a function of a multiplicity of post-cold war global contradictions. Inclusive governance, social justice and economic security are articulated as workable panaceas for mitigating warfare in Africa.

Keywords: Africa, conflicts, pattern, war

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Authors: T. Angeline Priyanka, R. Ganesan

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Recent trends in microelectronics technology have gradually changed the strategies used in very large scale integration (VLSI) circuits. Complementary Metal Oxide Semiconductor (CMOS) technology has been the industry standard for implementing VLSI device for the past two decades, but due to scale-down issues of ultra-low dimension achievement is not achieved so far. Hence it paved a way for Quantum Cellular Automata (QCA). It is only one of the many alternative technologies proposed as a replacement solution to the fundamental limit problem that CMOS technology will impose in the years to come. In this brief, presented a new adder that possesses high speed of operation occupying less area is proposed. This adder is designed especially for error tolerant application. Hence in the proposed adder, the overall area (cell count) and simulation time are reduced by 88 and 73 percent respectively. Various results of the proposed adder are shown and described.

Keywords: quantum cellular automata, carry look ahead adder, ripple carry adder, lossy application, majority gate, crossover

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Authors: Li-Hsueh Chen

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Efficient operation is more and more important for managers of hotels. Unlike the manufacturing industry, hotels cannot store their products. In addition, many hotels provide room service, and food and beverage service simultaneously. When efficiencies of hotels are evaluated, the internal structure should be considered. Hence, based on the operational characteristics of hotels, this study proposes a DEA model to simultaneously assess the efficiencies among the room production division, food and beverage production division, room service division and food and beverage service division. However, not only the enhancement of efficiency but also the adjustment of scale can improve the performance. In terms of the adjustment of scale, scale elasticity or returns to scale can help to managers to make decisions concerning expansion or contraction. In order to construct a reasonable approach to measure the efficiencies and scale elasticities of hotels, this study builds an alternative variable-returns-to-scale-based two-stage network DEA model with the combination of parallel and series structures to explore the scale elasticities of the whole system, room production division, food and beverage production division, room service division and food and beverage service division based on the data of international tourist hotel industry in Taiwan. The results may provide valuable information on operational performance and scale for managers and decision makers.

Keywords: efficiency, scale elasticity, network data envelopment analysis, international tourist hotel

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Authors: Patrick Nüß

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I estimate management opposition against unions in terms of hiring discrimination by a large scale field experiment in the German labor market. The results show that callback rates for union members decrease significantly in the presence of high sectoral union density and large firm size. I further explore how this effect varies with regional and sectoral labor dispute intensity and find that management opposition is stronger when a sector is exposed to an intense labor dispute. There is evidence that the observed management opposition can be explained by sectoral union threat effects. Sectors with lower hiring discrimination have lower coverage of collective agreements, and in the absence of a collective agreement, they are less likely to follow the collective agreement wage setting.

Keywords: trade unions, Industrial relations, management opposition, union threat, labor disputes, field experiments

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Authors: Xiaohua Zhu, Lingling Ma, Yongguang Zhao

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Leaf Area Index (LAI) is a key structural characteristic of crops and plays a significant role in precision agricultural management and farmland ecosystem modeling. However, LAI retrieved from different resolution data contain a scaling bias due to the spatial heterogeneity and model non-linearity, that is, there is scale effect during multi-scale LAI estimate. In this article, a typical farmland in semi-arid regions of Chinese Inner Mongolia is taken as the study area, based on the combination of PROSPECT model and SAIL model, a multiple dimensional Look-Up-Table (LUT) is generated for multiple crops LAI estimation from unmanned aerial vehicle (UAV) hyperspectral data. Based on Taylor expansion method and computational geometry model, a scale transfer model considering both difference between inter- and intra-class is constructed for scale effect analysis of LAI inversion over inhomogeneous surface. The results indicate that, (1) the LUT method based on classification and parameter sensitive analysis is useful for LAI retrieval of corn, potato, sunflower and melon on the typical farmland, with correlation coefficient R2 of 0.82 and root mean square error RMSE of 0.43m2/m-2. (2) The scale effect of LAI is becoming obvious with the decrease of image resolution, and maximum scale bias is more than 45%. (3) The scale effect of inter-classes is higher than that of intra-class, which can be corrected efficiently by the scale transfer model established based Taylor expansion and Computational geometry. After corrected, the maximum scale bias can be reduced to 1.2%.

Keywords: leaf area index (LAI), scale effect, UAV-based hyperspectral data, look-up-table (LUT), remote sensing

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Authors: Pitsanu Poonpetpun, Witthaya Mekhum, Warangkana Kongsil

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This research was an attempt to study work motivation of employees in Siam Thai Co., Ltd. The study took place in Rayong with 59 employees as participants. The research tool was questionnaires which consisted of sets of questions about company’s policy, management, executives and good relationship within the firm. The questionnaires style was rating scale with 5 score bands. The questionnaires were analyzed by percentage, frequency, mean and standard deviation. From the study, the result showed that policy and management were in moderate scale, executive and managers were in moderate scale and relationship within the firm were in high scale.

Keywords: motivation, job, performance, employees

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Authors: Shawn G. Gallaher, Lilli E. Hirth

Abstract:

As permafrost thaws with the continued warming of the Alaskan North Slope, a progressively thicker active thaw layer is evidently releasing previously sequestered nutrients, metals, and particulate matter exposed to fluvial transport. In this study, we estimate material fluxes on the North Slope of Alaska during the 2019-2022 melt seasons. The watershed of the Alaskan North Slope can be categorized into three regions: mountains, tundra, and coastal plain. Precipitation and discharge data were collected from repeat visits to 14 sample sites for biogeochemical surface water samples, 7 point discharge measurements, 3 project deployed meteorology stations, and 2 U. S. Geological Survey (USGS) continuous discharge observation sites. The timing, intensity, and spatial distribution of precipitation determine the material flux composition in the Sagavanirktok and surrounding bodies of water, with geogenic constituents (e.g., dissolved inorganic carbon (DIC)) expected from mountain flushed events and biogenic constituents (e.g., dissolved organic compound (DOC)) expected from transitional tundra precipitation events. Project goals include connecting late summer precipitation events to peak discharge to determine the responses of the watershed to localized atmospheric forcing. Field study measurements showed widespread precipitation in August 2019, generating an increase in total suspended solids, dissolved organic carbon, and iron fluxes from the tundra, shifting the main-stem mountain river biogeochemistry toward tundra source characteristics typically only observed during the spring floods. Intuitively, a large-scale precipitation event (as defined by this study as exceeding 12.5 mm of precipitation on a single observation day) would dilute a body of water; however, in this study, concentrations increased with higher discharge responses on several occasions. These large-scale precipitation events continue to produce peak constituent fluxes as the thaw layer increases in depth and late summer precipitation increases, evidenced by 6 large-scale events in July 2022 alone. This increase in late summer events is in sharp contrast to the 3 or fewer large events in July in each of the last 10 years. Changes in precipitation intensity, timing, and location have introduced late summer peak constituent flux events previously confined to the spring freshet.

Keywords: Alaska North Slope, arctic rivers, material flux, precipitation

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Authors: Chung-Yuan Huang, Yu-Hsiang Fu, Chuen-Tsai Sun

Abstract:

Community detection represents an important data-mining tool for analyzing and understanding real-world complex network structures and functions. We believe that at least four criteria determine the appropriateness of a community detection algorithm: (a) it produces useable normalized mutual information (NMI) and modularity results for social networks, (b) it overcomes resolution limitation problems associated with synthetic networks, (c) it produces good NMI results and performance efficiency for Lancichinetti-Fortunato-Radicchi (LFR) benchmark networks, and (d) it produces good modularity and performance efficiency for large-scale real-world complex networks. To our knowledge, no existing community detection algorithm meets all four criteria. In this paper, we describe a simple hierarchical arc-merging (HAM) algorithm that uses network topologies and rule-based arc-merging strategies to identify community structures that satisfy the criteria. We used five well-studied social network datasets and eight sets of LFR benchmark networks to validate the ground-truth community correctness of HAM, eight large-scale real-world complex networks to measure its performance efficiency, and two synthetic networks to determine its susceptibility to resolution limitation problems. Our results indicate that the proposed HAM algorithm is capable of providing satisfactory performance efficiency and that HAM-identified communities were close to ground-truth communities in social and LFR benchmark networks while overcoming resolution limitation problems.

Keywords: complex network, social network, community detection, network hierarchy

Procedia PDF Downloads 191

Authors: Wei Zhang, Lifen Zhao

Abstract:

The present study aims to translate and validate the Career Motivation Scale among Chinese university and vocational college teachers. Exploratory factor analysis supported a three-factor structure that was consistent with the original structure of career motivation: career insight, career identity, and career resilience. Confirmatory factor analysis showed that a second-order three-factor model with correlated measurement errors best fit the data. Configural, metric, and scalar invariance models were tested, demonstrating that the Chinese version of the Career Motivation Scale did not differ across groups of school type, educational level, and working years in current institutions. The concurrent validity of the Chinese Career Motivation Scale was confirmed by its significant correlations with work engagement, career adaptability, career satisfaction, job crafting, and intention to quit. The results of the study indicated that the Chinese Career Motivation Scale was a valid and reliable measure of career motivation among university and vocational college teachers in China.

Keywords: career motivation scale, Chinese University, vocational college teachers, measurement invariance, validation

Procedia PDF Downloads 96

Authors: Ambra Giovannelli, Coriolano Salvini

Abstract:

Many efforts have been spent in the design and development of Concentrated Solar Power (CPS) Plants worldwide. Most of them are for on-grid electricity generation and they are large plants which can benefit from the economies of scale. Nevertheless, several potential applications for Small and Medium-Scale CSP plants can be relevant in the industrial sector as well as for off-grid purposes (i.e. in rural contexts). In a wide range of industrial processes, CSP technologies can be used for heat generation replacing conventional primary sources. For such market, proven technologies (usually hybrid solutions) already exist: more than 100 installations, especially in developing countries, are in operation and performance can be verified. On the other hand, concerning off-grid applications, solar technologies are not so mature. Even if the market offers a potential deployment of such systems, especially in countries where the access to grid is strongly limited, optimized solutions have not been developed yet. In this context, steam power plants can be taken into consideration for medium scale installations, due to the recent results achieved with direct steam generation systems based on paraboloidal dish or Fresnel lens solar concentrators. Steam at 4.0-4.5 MPa and 500°C can be produced directly by means of innovative solar receivers (some prototypes already exist). Although it could seem a promising technology, presently, steam turbines commercially available do not cover the required cycle specifications. In particular, while low-pressure turbines already exist on the market, high-pressure groups, necessary for the abovementioned applications, are not available. The present paper deals with the preliminary design of a high-pressure steam turbine group for a medium-scale CSP plant (200-1000 kWe). Such a group is arranged in a single geared package composed of four radial expander wheels. Such wheels have been chosen on the basis of automotive turbocharging technology and then modified to take the new requirements into account. Results related to the preliminary geometry selection and to the analysis of the high-pressure turbine group performance are reported and widely discussed.

Keywords: concentrated solar power (CSP) plants, steam turbine, radial turbine, medium-scale power plants

Procedia PDF Downloads 190

Authors: Do Chi Thanh, Dang Ngoc Huy

Abstract:

Nowadays, there are more and more variable speed drive systems in small-scale and large-scale applications such as the electric vehicle industry, household appliances, medical equipment, and other industrial fields led to the development of BLDC (Brushless DC) motors. BLDC drive has many advantages, such as higher efficiency, better speed torque characteristics, high power density, and low maintenance cost compared to other conventional motors. Most BLDC motors use a proportional-integral (PI) controller and a pulse width modulation (PWM) scheme for speed control. This article describes the simulation model of BLDC motor drive control with the help of MATLAB - SIMULINK simulation software. The built simulation model includes a BLDC motor dynamic block, Hall sensor signal generation block, inverter converter block, and PI controller.

Keywords: brushless DC motor, BLDC, six-step inverter, PI speed

Procedia PDF Downloads 44