Search results for: high speed milling

Authors: H. M. Mohammad, A. Martin, N. Brown, N. Hodson, P. Hill, E. Roberts

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Graphite intercalation compound (GIC) has been demonstrated to be a useful, low capacity and rapid adsorbent for the removal of organic micropollutants from water. The high electrical conductivity and low capacity of the material lends itself to electrochemical regeneration. Following electrochemical regeneration, equilibrium loading under similar conditions is reported to exceed that achieved by the fresh adsorbent. This behavior is reported in terms of the regeneration efficiency being greater than 100%. In this work, surface analysis techniques are employed to investigate the material in three states: ‘Fresh’, ‘Loaded’ and ‘Regenerated’. ‘Fresh’ GIC is shown to exhibit a hydrogen and oxygen rich surface layer approximately 150 nm thick. ‘Loaded’ GIC shows a similar but slightly thicker surface layer (approximately 370 nm thick) and significant enhancement in the hydrogen and oxygen abundance extending beyond 600 nm from the surface. 'Regenerated’ GIC shows an oxygen rich layer, slightly thicker than the fresh case at approximately 220 nm while showing a very much lower hydrogen enrichment at the surface. Results demonstrate that while the electrochemical regeneration effectively removes the phenol model pollutant, it also oxidizes the exposed carbon surface. These results may have a significant impact on the estimation of adsorbent life.

Keywords: graphite, adsorbent, electrochemical, regeneration, phenol

Procedia PDF Downloads 139

Authors: Muhammad Anwar, Ameen Ullah, Intakhab Alam Qadri

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This study presents a technique utilizing the Iterative Rational Krylov Algorithm (IRKA) to reduce the order of large-scale descriptor systems. Descriptor systems, which incorporate differential and algebraic components, pose unique challenges in Model Order Reduction (MOR). The proposed method partitions the descriptor system into polynomial and strictly proper parts to minimize approximation errors, applying IRKA exclusively to the strictly adequate component. This approach circumvents the unbounded errors that arise when IRKA is directly applied to the entire system. A comparative analysis demonstrates the high accuracy of the reduced model and a significant reduction in computational burden. The reduced model enables more efficient simulations and streamlined controller designs. The study highlights IRKA-based MOR’s effectiveness in optimizing complex systems’ performance across various engineering applications. The proposed methodology offers a promising solution for reducing the complexity of large-scale descriptor systems while maintaining their essential characteristics and facilitating their analysis, simulation, and control design.

Keywords: model order reduction, descriptor systems, iterative rational Krylov algorithm, interpolatory model reduction, computational efficiency, projection methods, H₂-optimal model reduction

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Authors: Nikolai Brosch, Alwine Mohnen

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Academics and business leaders increasingly call for a (re)definition of a corporate purpose beyond profit-maximization to contribute to the welfare of society. This study investigates the effect of communicating such a pro-social corporate purpose on three employee-level outcomes that constitute major cost components for most organizations: workers reservation wage, work quality, and work misbehavior. To provide causal evidence, two natural field experiments were conducted with almost 2,000 workers recruited from different online labor marketplaces. Workers were randomly assigned to treatments manipulating whether or not they received information about the employer’s corporate purpose and subsequently performed a short, real-effort task for payment. The main findings in both experiments show that receiving information about an employer’s pro-social corporate purpose causes workers to accept lower wages (9% lower in the first experiment and 28% lower in the second experiment) for the same job. Workers that personally assess high importance to organizations having a pro-social purpose are most responsive. At the same time, sacrificing wage for a corporate purpose comes at no cost of quality and even decreases the likelihood of engaging in work misbehavior. In a broader context, the results provide some evidence that the (re)definition of corporate purpose in commercial organizations is not ultimately at odds with creating profits.

Keywords: corporate purpose, natural field experiment, reservation wage, work misbehavior, work quality

Procedia PDF Downloads 239

Authors: Emanuele Bonamente, Andrea Aquino, Franco Cotana

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The exploitation of the low-temperature geothermal resource via ground-source heat pumps is often limited by the high investment cost mainly due to borehole drilling. From the monitoring of a prototypal system currently used by a commercial building, it was found that a simple upgrade of the conventional layout, obtained including a thermal storage between the ground-source heat exchangers and the heat pump, can optimize the ground energy exploitation requiring for shorter/fewer boreholes. For typical applications, a reduction of up to 66% with respect to the conventional layout can be easily achieved. Results from the monitoring campaign of the prototype are presented in this paper, and upgrades of the thermal storage using phase change materials (PCMs) are proposed using computational fluid dynamics simulations. The PCM thermal storage guarantees an improvement of the system coefficient of performance both for summer cooling and winter heating (up to 25%). A drastic reduction of the storage volume (approx. 1/10 of the original size) is also achieved, making it possible to easily place it within the technical room, avoiding extra costs for underground displacement. A preliminary optimization of the PCM geometry is finally proposed.

Keywords: computational fluid dynamics (CFD), geothermal energy, ground-source heat pumps, phase change materials (PCM)

Procedia PDF Downloads 267

Authors: M. P. Raju, P. D. Safai, P. S. P. Rao, P. C. S. Devara, C. V. Naidu

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In order to study the Physical and chemical characteristics of aerosols, samples of Total Suspended Particulates (TSP) were collected using a high volume sampler at Pune, a semi-urban location in SW India during March 2009 to February 2010. TSP samples were analyzed for water soluble components like F, Cl, NO3, SO4, NH4, Na, K, Ca, and Mg and acid soluble components like Al, Zn, Fe and Cu using Ion-Chromatograph and Atomic Absorption Spectrometer. Analysis of the data revealed that the monthly mean TSP concentrations varied between 471.3 µg/m3 and 30.5 µg/m3 with an annual mean value of 159.8 µg/m3. TSP concentrations were found to be less during post-monsoon and winter (October through February), compared to those in summer and monsoon (March through September). Anthropogenic activities like vehicular emissions and dust particles originated from urban activities were the major sources for TSP. TSP showed good correlation with all the major ionic components, especially with SO4 (R= 0.62) and NO3 (R= 0.67) indicating the impact of anthropogenic sources over the aerosols at Pune. However, the overall aerosol nature was alkaline (Ave pH = 6.17) mainly due to the neutralizing effects of Ca and NH4. SO4 contributed more (58.8%) to the total acidity as compared to NO3 (41.1%) where as, Ca contributed more (66.5%) to the total alkalinity than NH4 (33.5%). Seasonality of acid soluble component Al, Fe and Cu showed remarkable increase, indicating the dominance of soil source over the man-made activities. Overall study on TSP indicated that aerosols at Pune were mainly affected by the local sources.

Keywords: chemical composition, acidic and neutralization potential, radiative forcing, urban station

Procedia PDF Downloads 244

Authors: Bouthiba Amina

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The estimation of the statistics bound to the precipitation represents a vast domain, which puts numerous challenges to meteorologists and hydrologists. Sometimes, it is necessary, to approach in value the extreme events for sites where there is little, or no datum, as well as their periods of return. The search for a model of the frequency of the heights of daily rains dresses a big importance in operational hydrology: It establishes a basis for predicting the frequency and intensity of floods by estimating the amount of precipitation in past years. The most known and the most common approach is the statistical approach, It consists in looking for a law of probability that fits best the values observed by the random variable " daily maximal rain " after a comparison of various laws of probability and methods of estimation by means of tests of adequacy. Therefore, a frequent analysis of the annual series of daily maximal rains was realized on the data of 54 pluviometric stations of the pond of high and average. This choice was concerned with five laws usually applied to the study and the analysis of frequent maximal daily rains. The chosen period is from 1970 to 2013. It was of use to the forecast of quantiles. The used laws are the law generalized by extremes to three components, those of the extreme values to two components (Gumbel and log-normal) in two parameters, the law Pearson typifies III and Log-Pearson III in three parameters. In Algeria, Gumbel's law has been used for a long time to estimate the quantiles of maximum flows. However, and we will check and choose the most reliable law.

Keywords: return period, extreme flow, statistics laws, Gumbel, estimation

Procedia PDF Downloads 79

Authors: Antoine Vikkey Hinson, Ranty Jolianelle Dassi, Menonli Adjobimey, Rose Mikponhoue, Paul Ayelo

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Introduction: The psychological hardship of the teaching profession maintains a chronic stress that inevitably evolves into burnout (BO) in the absence of adequate preventive measures. The objective of this study is to study the prevalence and factors associated with burnout among secondary school teachers in the city of Cotonou in 2022. Methods: This was a descriptive cross-sectional study with an analytical aim and prospective data collection that took place over a period of 2 months, from July 19 to August 19 and from October 1 to October 31, 2022. Sampling was done using a three-stage probability sampling technique. Data analysis was performed using R 4.1.1 software. Bivariate logistic regression was used to identify associated factors. The significance level chosen was 5% (p < 0.05). Results: A total of 270 teachers were included in the study, of whom 208 (77.00%) were men. The mean age of the workers was 38.03 ± 8.30 years. According to the Maslach Burnout Inventory, 58.51% of the teachers had burnout, with 41.10% of teachers in emotional exhaustion, 27.40% in depersonalization and 21.90% in loss of personal accomplishment. The severity of the syndrome was low to moderate in almost all teachers. The occurrence of BO was associated with), not practicing sports (ORa= 2,38 [1,32; 4,28]), jobs training (ORa= 1,86 [1,04; 3,34]) and an imbalance of effort/reward (ORa= 5,98 [2,24;15,98]). Conclusion: The prevalence of BO is high among secondary school teachers in the city of Cotonou. A larger scale study, including research on its consequences on the teacher and the learner, is necessary in order to act quickly to implement a prevention program.

Keywords: burnout, teachers, Maslach burnout inventory, associated factors, Benin

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Authors: Paam Bidaya

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The red seaweed Gracilaria fisheri, widely distributed along Thailand's southern coastlines, has been discovered to be edible. Sulfated polysaccharides from G. fisheri were extracted in low-temperature (25 °C) water. Seaweed polysaccharides (SPs) have been shown to have various advantageous biological effects. This study aims to investigate total phenolic content and antioxidant capacity of G. fisheri extract. The total phenolic content of G. fisheri extract was determined using Folin-Cioucalteu method and calculated as gallic acid equivalents (GAE). The antioxidant activity of G. fisheri extract was performed via 2, 2-diphenyl-1- picrylhydrazyl (DPPH) free radical scavenging assay and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity assays. The findings exhibited a strong correlation between antioxidant activity and the total phenol contents. In addition, DPPH and ABTS assays showed that G. fisheri extract showed antioxidant activities as a concentration-dependent manner. The IC50 values of G. fisheri extract were 902.19 μg/mL ± 0.785 and 727.98 μg/mL ± 0.822 for DPPH and ABTS, respectively. Vitamin C was used as a positive control in DPPH assay, while Trolox was used as a positive control in ABTS assay. To conclude, G. fisheri extract consists of a high amount of total phenolic content, which exhibit a significant antioxidant activity. However, further investigation regarding antioxidant activity should be performed in order to identify the mechanism of Gracilaria fisheri action.

Keywords: ABTS assay, DPPH assay, sulfated polysaccharides, total phenolic content

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Authors: Andrey V. Malyshev, Anna B. Petrova, Anatoly P. Surzhikov

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The article presents the results of the influence of diamagnetic additives on the defects level of ferrite ceramics. For this purpose, we use a previously developed method based on the mathematical analysis of experimental temperature dependences of the initial permeability. A phenomenological expression for the description of such dependence was suggested and an interpretation of its main parameters was given. It was shown, that the main criterion of the integral defects level of ferrite ceramics is the relation of two parameters correlating with elastic stress value in a material. Model samples containing a controlled number of intergranular phase inclusions served to prove the validity of the proposed method, as well as to assess its sensitivity in comparison with the traditional XRD (X-ray diffraction) analysis. The broadening data of diffraction reflexes of model samples have served for such comparison. The defects level data obtained by the proposed method are in good agreement with the X-ray data. The method showed high sensitivity. Therefore, the legitimacy of the selection relationship β/α parameters of phenomenological expression as a characteristic of the elastic state of the ferrite ceramics confirmed. In addition, the obtained data can be used in the detection of non-magnetic phases and testing the optimal sintering production technology of soft magnetic ferrites.

Keywords: cure point, initial permeability, integral defects level, homogeneity

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Authors: Halimah Al Hifzi, Waseem Al-Talalwah, Shorok Al Dorazi, Hassan Al Mousa, Zainab Al-Hashim, Roger Soames

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The obturator artery is one branches of anterior division of the internal iliac artery. It passes on the lateral wall of pelvis to escape into thigh region via obturator foremen. Based on previous research studies, it found to be extremely variable in origin and course. It may arise from internal or external iliac artery. The current study includes 82 dissected specimens to investigate the origin of the obturator artery and explain the clinical importance. The obturator artery arises from the internal iliac artery in 75% either from its anterior or posterior division in 46.9% or 25% respectively. Further, it arises neither from the anterior nor posterior division of the internal iliac artery but it arises between them in 3.1%. In 25%, the obturator artery arises from the external iliac artery. In case of aneurysmectomy of posterior division, carries a high risk of insufficient of vascular supply for demand structures such as proximal adductors attachment and hip joint. Therefore, vascular surgeons have to pay attention to the posterior division being an origin of the obturator artery beside its usual three classical branches: superior gluteal, iliolumbar and lateral sacral arteries. Further, the obturator artery arising from the external iliac system is in great dangerous of laceration in case of anterior pelvic fracture. Therefore, it may lead to haemorrhagic shock threatening life.

Keywords: obturator artery, external iliac, internal iliac artery, anterior division, posterior division, superior gluteal, iliolumbar and lateral sacral, pubic fracture, aneurysm, shock

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Authors: Saurabh Chaudhury, Sanjeet Kumar Sinha

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The MOSFET has been the main building block in high performance and low power VLSI chips for the last several decades. Device scaling is fundamental to technological advancements, which allows more devices to be integrated on a single die providing greater functionality per chip. Ultimately, the goal of scaling is to build an individual transistor that is smaller, faster, cheaper, and consumes less power. Scaling continued following Moore's law initially and now we see an exponential growth in today's nano scaled chip. However, device scaling to deep nano meter regime leads to exponential increase in leakage currents and excessive heat generation. Moreover, fabrication process variability causing a limitation to further scaling. Researchers believe that with a mix of chemistry, physics, and engineering, nano electronics may provide a solution to increasing fabrication costs and may allow integrated circuits to be scaled beyond the limits of the modern transistor. Carbon nano tube (CNT) and nano wires (NW) based FETs have been analyzed and characterized in laboratory and also been demonstrated as prototypes. This work presents an extensive simulation based study and analysis of CNTFET and NW-FET devices and comparison of the results with conventional MOSFET. From this study, we can conclude that these devices have got some excellent properties and favorable characteristics which will definitely lead the future semiconductor devices in post silicon era.

Keywords: carbon nanotube, nanowire FET, low power, nanoscaled devices, VLSI

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Authors: Juliana Sagretti, Susy Sabato

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Despite the poverty in the world, a third of all food produced in the world is wasted. FAO, the United Nations Organization of Agriculture and Food, points out the need to combine actions and new technologies to combat hunger and waste in contrast to the high production of food in the world. The energy of ionizing radiation in food brought many positive results, such as increased validity and insect infestation control. The food banks are organizations that act at various points of food chain to collect and distribute food to the needy. So, the aim of this study was to initiate a partnership between irradiation and the food bank through the development of a questionnaire to evaluate and disseminate the knowledge and acceptance of individuals in the food bank in Brazil. In addition, this study aimed to standardize a basis questionnaire for future research assessment of irradiated foods. For the construction of the questionnaire as a measuring instrument, a comprehensive and rigorous literature review was made. Its covered qualitative research, questionnaires, sensory evaluation and food irradiated. Three stages of pre - tests were necessary and related fields of experts were consulted. As a result, the questionnaire has three parts, personal issues, assertive issues and questions of multiple choices and finally an informative question. The questionnaire was applied in Ceagesp food bank in the biggest center of food in Brazil (data not shown).

Keywords: food bank, food irradiation, food waste, sustainability

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Authors: Mejía M. Paula, Ramírez L. Leonardo, Puerta A. Gabriel

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In telemedicine, the image repository service is important to increase the accuracy of diagnostic support of medical personnel. This study makes comparison between two routing algorithms regarding the quality of service (QoS), to be able to analyze the optimal performance at the time of loading and/or downloading of medical images. This study focused on comparing the performance of Tabu Search with other heuristic and metaheuristic algorithms that improve QoS in telemedicine services in Colombia. For this, Tabu Search and Simulated Annealing heuristic algorithms are chosen for their high usability in this type of applications; the QoS is measured taking into account the following metrics: Delay, Throughput, Jitter and Latency. In addition, routing tests were carried out on ten images in digital image and communication in medicine (DICOM) format of 40 MB. These tests were carried out for ten minutes with different traffic conditions, reaching a total of 25 tests, from a server of Universidad Militar Nueva Granada (UMNG) in Bogotá-Colombia to a remote user in Universidad de Santiago de Chile (USACH) - Chile. The results show that Tabu search presents a better QoS performance compared to Simulated Annealing, managing to optimize the routing of medical images, a basic requirement to offer diagnostic images services in telemedicine.

Keywords: medical image, QoS, simulated annealing, Tabu search, telemedicine

Procedia PDF Downloads 219

Authors: Luciana Brandao Ferreira, Janaina de Moura Engracia Giraldi, Fabiana Gondim Mariutti, Marina Toledo de Arruda Lourencao

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Developing countries, such as BRICS (Brazil, Russia, India, China and South Africa) are hosting sports mega-events to promote socio-economic development and image enhancement. Thus, this paper aims to verify the image of Rio de Janeiro, in Brazil, as the host city of 2016 Olympic Games, considering the main cognitive and affective image dimensions. The research design uses exploratory factorial analysis to find the most important factors highlighted in the city image dimensions. The data were collected by structured questionnaires with an international respondents sample (n=274) with high international travel experience. The results show that Rio’s image as a sport mega-event host city has two main factors in each dimension: Cognitive ('General Infrastructure'; 'Services and Attractions') and Affective ('Positive Feelings'; 'Negative Feelings'). The most important factor related to cognitive dimension was 'Services and Attractions' which is more related to tourism activities. In the affective dimension 'Positive Feelings' was the most important factor, which means a good result considering that is a city in an emerging country with many unmet social demands.

Keywords: Rio de Janeiro, 2016 olympic games, host city image, cognitive image dimension, affective image dimension

Procedia PDF Downloads 147

Authors: Mustafa Ali Abugila, Basma Nuri Kajruba, Hanan Elhadi, Rehab Ramadan Wali

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Iron deficiency anemia is characterized by a decrease of Hb (hemoglobin), serum iron, ferritin, and RBC (red blood cells) (shape and size). Also, it is characterized by an increase in total iron binding capacity (TIBC). Red blood cells become microctytic and hypochromic due to a decrease in iron content. This study was conducted in the north west of Libya and included 210 women in childbearing age (18-45 years) who were visiting women clinic. After filling the questionnaire, blood samples were taken and analyzed for hematological and biochemical profiles. Biochemical tests included measurement of serum iron, ferritin, and total iron binding capacity (TIBC). Among the total sample (210 women), there were 87 (41.42%) pregnant and 123 (58.57%) non-pregnant women (includes married and single). Pregnant women (87) were classified according to the gestational age into first, second, and third trimesters. The means of biochemical and hematological parameters in the studied samples were: Hb = 10.37± 2.02 g/dl, RBC = 3.78± 1.037 m/m3, serum iron 61.86± 40.28 µg/dl, and TIBC = 386.01 ± 94.91 µg/dl. In this study, we considered that any women have hemoglobin below 11.5 g/dl is anemic. 89.1%, 69.5%, and 47.8% of pregnant women who belong to third trimester had low (below normal value) Hb, serum iron, and ferritin, i.e. iron deficiency anemia was more common in third trimester among the first and the second trimesters. Third trimester pregnant women also had high TIBC more than first and second trimesters.

Keywords: red blood cells, hemoglobin, total iron binding capacity, ferritin

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Authors: Rym Sassi, Franck Fayon, Mohend Chaouche, Emmanuel Veron, Valerie Montouillout

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The chemical phenomena occurring during cement hydration are complex and interdependent, and even after almost two centuries of studies, they are still difficult to solve for complex mixtures combining different hydraulic binders. Powder-XRD has been widely used for characterizing the crystalline phases in both anhydrous and hydrated cement, but only limited information is obtained in the case of strongly disordered and amorphous phases. In contrast, local spectroscopies like solid-state NMR can provide a quantitative description of noncrystalline phases. In this work, the structural modifications occurring during hydration of a fast-setting ternary binder based on white Portland cement, white calcium aluminate cement, and calcium sulfate were investigated using advanced solid-state NMR methods. We particularly focused on the early stage of the hydration up to 28 days, working with samples whose hydration was controlled and stopped. ²⁷Al MQ-MAS as well as {¹H}-²⁷Al and {¹H}-²⁹Si Cross- Polarization MAS NMR techniques were combined to distinguish all of the aluminum and silicon species formed during the hydration. The NMR quantification of the different phases was conducted in parallel with the XRD analyses. The consumption of initial products, as well as the precipitation of hydraulic phases (ettringite, monosulfate, strätlingite, CSH, and CASH), were unambiguously quantified. Finally, the drawing of the consumption and formation of phases was correlated with mechanical strength measurements.

Keywords: cement, hydration, hydrates structure, mechanical strength, NMR

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Authors: Etika Sukma Adiyanti, H. N. Nurul Huda Putu Ekapraja, Gugun Gunawan

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Global warming causes climate change and sea level rise. This is a threat for coastal regions, especially for coastal settlements with activities that are influenced by this natural phenomenon. Consequences are damage of houses, humid house environment, sustainability of the houses, obstructed economic activities and domestic works, disruption of sanitation facilities, lack of electricity, failure of transport system, psychological issues and other. Icons Tambak Lorok as 'Fisherman Village' is not something familiar to residents of the city of Semarang. Especially for the housewife who every day have to buy the ingredients high in protein and omega fish auction which is adjacent to the main street market in the village of Tambak Lorok. However, there are major problems that are being experienced by this small neighborhood. In fact, this issue includes seven infrastructure that should spoil the fishermen in activity with marine life. With this research, we will investigate water urbanism and climate change resiliency in Semarang, specifically the traditional fisher community of Tambak Lorok. We intend to find out how the local people in the fisher settlement Tambak Lorok deal with water urbanism, proverty and living with floods. So, we have a good solution for this problem, Floating Stage. We think that Tambak Lorok needs a new design for the common future. With this, One Building at A Time for Tambak Lorok, will be a good solution.

Keywords: fisher community, environment, climate change, settlement

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Authors: Ali Muhammad

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The study investigates the effect of a number of contextual on the degree of trust within Kuwaiti business organizations. The model used in this study suggests that degree of trust within the organization is determined by four contextual variables, namely, centralization, formalization, role ambiguity, and procedural justice. Organizational trust refers to employee’ positive assumptions in regard to the goal and behaviors of other members in the organization according to organizational duties, relationships, experiences, and interrelatedness. According to the norm of reciprocity, individuals with high perceived organizational justice will be compelled to react positively to the organization in the form of higher degree of trust. The duty to exchange kindness for kindness. Based on the exchange theory, this research proposes that procedural justice, role clarity, and voice in the organization will lead to the perception of an organization’s discretionary positive treatment of employees and, in return enhances their trust in the organization. Survey data were collected from a sample of 206 employees working in Kuwaiti business organizations. Results of multiple regression analysis revealed that both organizational justice and formalization have positive effects on organizational trust. Furthermore, results indicate that lower degree of role ambiguity leads to higher degree of organizational trust. On the other hand, centralization was not found to have a significant effect on organizational trust. Implications of the findings and directions for future research are discussed.

Keywords: centralization, formalization, organizational justice, organizational trust, role ambiguity

Procedia PDF Downloads 189

Authors: L. Vujičić, Ž. Ivković, Ž. Boneta

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There is a widespread belief in everyday discourse that science subjects (physics, chemistry and biology) are, along with math, the most difficult school subjects in the education of an individual. This assumption is usually justified by the following facts: low GPA in these subjects, the number of pupils who fail these subjects is high in comparison to other subjects, and the number of pupils interested in continuing their studies in the fields with a focus on science subjects is lower compared to non-science-oriented fields. From that perspective, the project: “Could it be different? How do children explore it?” becomes extremely interesting because it is focused on young children and on the introduction of new methods, with aim of arousing interest in scientific literacy development in 10 kindergartens by applying the methodology of an action research, with an ethnographic approach. We define scientific literacy as a process of encouraging and nurturing the research and explorative spirit in children, as well as their natural potential and abilities that represent an object of scientific research: to learn about exploration by conducting exploration. Upon project completion, an evaluation questionnaire was created for the parents of the children who had participated in the project, as well as for those whose children had not been involved in the project. The purpose of the first questionnaire was to examine the level of satisfaction with the project implementation and its outcomes among those parents whose children had been involved in the project (N=142), while the aim of the second questionnaire was to find out how much the parents of the children not involved (N=154) in this activity were interested in this topic.

Keywords: documenting, early childhood education, evaluation questionnaire for parents, scientific literacy development

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Authors: Ming Ma, Zhenyu Cai, Rui Li

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People are more vulnerable to health problems than ever before, such as overweight and obesity due to the change of built environment. In the high-rise buildings, the core-tube layout is closely associated with user’s physical activities which will affect human’s health in a long-term. As for the white-collars who spends the amount of time working in the office tower, using staircase seems to provide an opportunity for them to increase the physical activities in the workplaces. This paper is aiming to find out the specific relationship between health and core-tube in the office tower through analyzing the correlation between staircase’s layout and user’s health. The variables of staircase’s layout are consisted of two indicators: plan layout and space design, including nine factors while health variable is applying BIM as the only main factor. 14 office towers in downtown Shanghai are selected as the research samples because of its typical users’ pattern and similar core-tube layout. In the result, it is obvious that the users from these 14 cases have higher BMI than average partly because that the staircases are mainly designed for emergency and fire instead of daily use. After the regression and correlation analysis of the variables of health and staircases, it’s found that users’ BMI is significantly associated with the factors of floor guide-signs and distance from lobby to the staircase. In addition, the factors of comfort level of staircase such as width and daylighting have a certain correlation with users’ BMI.

Keywords: office tower, staircase, design, obesity, physical activity

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Authors: I. Mentziou, C. Delezos, D. Krikidis, A. Nestoridou, G. Boskou

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Introduction: The systems of production and distribution of meals can have a significant impact on the food intake of hospital patients who are likely to develop malnutrition. In hospitals, the consequences of food borne infections can range from annoying to life-threatening for a patient, since they can lead up to death in vulnerable groups Aim: The aim of the present study was the evaluation of food safety management systems implementation, as well as the general evaluation of the total quality management systems in Greek hospitals. Methods: This is a multifocal study on the implementation and evaluation of the food safety management systems in the Greek hospitals of Attica region. Eleven hospitals from the city of Athens were chosen for this purpose. The sample was derived from the high rank personnel of the nutritional department (dietician, head-chef, food technologist, public health inspector). Tailor made questionnaires on hygiene regulations were used as tools for the interviews. Results: Overall, 30 employees in the field of hospital nutrition participated. Most of the replies implied that almost always the hygiene regulations are implemented. Nevertheless, only 30% stated that there is a Hazard Analysis Critical Control Points HACCP system (HACCP) in the hospital. In a small number of questionnaires there were proposals for changes by the staff. Conclusion: Measurement of the opinion of the personnel about the provided food services within a hospital can further lead to continuous improvement of the hospital nutrition.

Keywords: evaluation, food service, HACCP, hospital, personnel

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Authors: H. Gokdemir

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All structures are subject to vertical and lateral loads. Under these loads, structures make deformations and deformation values of structural elements mustn't exceed their capacity for structural stability. Especially, lateral loads cause critical deformations because of their random directions and magnitudes. Wind load is one of the lateral loads which can act in any direction and any magnitude. Although wind has nearly no effect on reinforced concrete structures, it must be considered for steel structures, roof systems and slender structures like minarets. Therefore, every structure must be able to resist wind loads acting parallel and perpendicular to any side. One of the effective methods for resisting lateral loads is assembling cross steel elements between columns which are called as wind bracing. These cross elements increases lateral rigidity of a structure and prevent exceeding of deformation capacity of the structural system. So, this means cross elements are also effective in resisting earthquake loads too. In this paper; Effects of wind bracing to earthquake resistance of structures are studied. Structure models (with and without wind bracing) are generated and these models are solved under both earthquake and wind loads with different seismic zone parameters. It is concluded by the calculations that; in low-seismic risk zones, wind bracing can easily resist earthquake loads and no additional reinforcement for earthquake loads is necessary. Similarly; in high-seismic risk zones, earthquake cross elements resist wind loads too.

Keywords: wind bracings, earthquake, steel structures, vertical and lateral loads

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Authors: Xie Weifan, Wang Zhongde

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Everyday landscape in the countryside has long played an important role as a cultural representation of the countryside and a link between the countryside and social relations. In the transformation of modernization, the daily landscape in the countryside needs to change with the transformation of daily life in countryside therefore, interpreting the daily landscape in the countryside and understanding the basic characteristics and value perception of the daily landscape from the villagers' perspective can help to understand the daily landscape in the countryside and its conservation and development. Taking Lizi Village in Qianjiang District, Chongqing Municipality, China, as a case study, we collected important daily landscapes in villagers' perceptions through in-depth interviews, categorized them into personal living space, public affairs space, and public activity space, and analyzed the characteristics of the spatial distribution of daily landscapes. The perceptual characteristics of the villagers' perceptions are analyzed and divided into four major types, namely, physical environment perception, atmosphere and culture perception, emotional feelings, and behavioral preferences, and their perceptual characteristics are analyzed respectively to understand the important characteristics of the villagers' perceptions of the daily landscapes. Finally, it is proposed that the protection and development of daily landscape in villages need to improve the mechanism of discovering and evaluating daily landscape, encourage residents to participate in the construction of daily landscape, protect the high-value daily landscape, and promote the innovative development of daily landscape.

Keywords: rural landscape, everyday landscape, landscape perception, conservation and development

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Authors: Talal Al-Bazali, S. Mohammad

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The threshold capillary pressure of shale caprocks is an important parameter in CO₂ storage modeling. A correct estimation of the threshold capillary pressure is not only essential for CO₂ storage modeling but also important to assess the overall economical and environmental impact of the design process. A standard step by step approach has to be used to measure the threshold capillary pressure of shale and non-wetting fluids at different temperatures. The objective of this work is to assess the impact of high temperature on the threshold capillary pressure of four different shales as they interacted with four different oil based muds, air, CO₂, N₂, and methane. This study shows that the threshold capillary pressure of shale and non-wetting fluid is highly impacted by temperature. An empirical correlation for the dependence of threshold capillary pressure on temperature when different shales interacted with oil based muds and gasses has been developed. This correlation shows that the threshold capillary pressure decreases exponentially as the temperature increases. In this correlation, an experimental constant (α) appears, and this constant may depend on the properties of shale and non-wetting fluid. The value for α factor was found to be higher for gasses than for oil based muds. This is consistent with our intuition since the interfacial tension for gasses is higher than those for oil based muds. The author believes that measured threshold capillary pressure at ambient temperature is misleading and could yield higher values than those encountered at in situ conditions. Therefore one must correct for the impact of temperature when measuring threshold capillary pressure of shale at ambient temperature.

Keywords: capillary pressure, shale, temperature, thresshold

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Authors: M. Khazam, M. Altawil, A. Eljabri

Abstract:

Fluid properties in states near a vapor-liquid critical region are the most difficult to measure and to predict with EoS models. The principal model difficulty is that near-critical property variations do not follow the same mathematics as at conditions far away from the critical region. Libyan NC98 field in Sirte basin is a typical example of near critical fluid characterized by high initial condensate gas ratio (CGR) greater than 160 bbl/MMscf and maximum liquid drop-out of 25%. The objective of this paper is to model NC98 phase behavior with the proper selection of EoS parameters and also to model reservoir depletion versus gas cycling option using measured PVT data and EoS Models. The outcomes of our study revealed that, for accurate gas and condensate recovery forecast during depletion, the most important PVT data to match are the gas phase Z-factor and C7+ fraction as functions of pressure. Reasonable match, within -3% error, was achieved for ultimate condensate recovery at abandonment pressure of 1500 psia. The smooth transition from gas-condensate to volatile oil was fairly simulated by the tuned PR-EoS. The predicted GOC was approximately at 14,380 ftss. The optimum gas cycling scheme, in order to maximize condensate recovery, should not be performed at pressures less than 5700 psia. The contribution of condensate vaporization for such field is marginal, within 8% to 14%, compared to gas-gas miscible displacement. Therefore, it is always recommended, if gas recycle scheme to be considered for this field, to start it at the early stage of field development.

Keywords: EoS models, gas-condensate, gas cycling, near critical fluid

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Authors: Soroush Momeni

Abstract:

Excellent damping capacity and superelasticity of the bulk NiTi shape memory alloy (SMA) makes it a suitable material of choice for tools in machining process as well as tribological systems. Although thin film of NiTi SMA has a same damping capacity as NiTi bulk alloys, it has a poor mechanical properties and undesirable tribological performance. This study aims at eliminating these application limitations for NiTi SMA thin films. In order to achieve this goal, NiTi thin films were magnetron sputtered as an interlayer between reactively sputtered hard TiCN coatings and hard work tool steel substrates. The microstructure, composition, crystallographic phases, mechanical and tribological properties of the deposited thin films were analyzed by using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), nanoindentation, ball–on-disc, scratch test, and three dimensional (3D) optical microscopy. It was found that under a specific coating architecture, the superelasticity of NiTi inter-layer can be combined with high hardness and wear resistance of TiCN protective layers. The obtained results revealed that the thickness of NiTi interlayers is an important factor controlling mechanical and tribological performance of bi-layer composite coating systems.

Keywords: PVD coatings, sliding wear, hardness, tool steel

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Authors: Cornelius Michael Ekenta

Abstract:

The study determined institutional and technological factors that influence the adoption of tenera oil palm production practices with a gender dimension among smallholder farmers in Edo State, Nigeria. Primary data were generated with use of questionnaire administered to 155 males and 137 female respondents. Results show that the level of adoption of tenera oil palm production practices was low for both male and females. Tobi regression result shows that land ownership structure and affordability at 1% significance influenced male adoption of tenera oil palm production practices while age and level of income at 1% significance influenced female in the adoption. The major roles of male as reported in adopting process were purchase of seedlings, clearing of bush for planting and selling of cut bunches while the major roles of female were periodic weeding, gathering of cut bunches and mulching of palm field. The major constraint faced by male in adoption process were high cost of labour while for females is drudgery nature of the work. The study recommended that the Land Use Act of 1978 should be enforced to help women and non-indigenes to have sizeable farm lands, Government should empower Agricultural Development Programme (ADP) by employing more extension personnel to increase their contacts with the farmers.

Keywords: gender, adoption, variety, oil, tenera, Edo

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Authors: M. Arunachalam, M. Pandey

Abstract:

Nacre, a biological material that forms the inner-layer of sea shells can achieve high toughness and strength by way of staggered arrangement of strong tablets with soft and weak organic interface. Under applied loads the tablets slide over the adjacent tablets, thus generating inelastic deformation and toughness on macroscopic scale. A two dimensional finite element based homogenization methodology is adopted for obtaining the effective material properties of Nacre using a representative volume element (RVE) at finite deformations. In this work, the material behaviour for tablet and interface are assumed to be Isotropic elastic and Isotropic elastic-perfectly plastic with strain softening respectively. Numerical experiments such as uniaxial tension test along X, Y directions and simple shear test are performed on the RVE with uniform displacement and periodic constraints applied at the RVE boundaries to obtain the anisotropic homogenized response and maximum local stresses within each constituents of Nacre. Homogenized material model is then tested for macroscopic structure under three point bending condition and the results obtained are comparable with the results obtained for detailed microstructure based structure, thus homogenization provides a bridge between macroscopic scale and microscopic scale and homogenized material properties obtained from microstructural (RVE) analysis could be used in large scale structural analysis.

Keywords: finite element, homogenization, inelastic deformation, staggered arrangement

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Authors: David Jurado, Carlos Ávila

Abstract:

Detection of early signs of breast cancer development is crucial to quickly diagnose the disease and to define adequate treatment to increase the survival probability of the patient. Computer Aided Detection systems (CADs), along with modern data techniques such as Machine Learning (ML) and Neural Networks (NN), have shown an overall improvement in digital mammography cancer diagnosis, reducing the false positive and false negative rates becoming important tools for the diagnostic evaluations performed by specialized radiologists. However, ML and NN-based algorithms rely on datasets that might bring issues to the segmentation tasks. In the present work, an automatic segmentation and detection algorithm is described. This algorithm uses image processing techniques along with the Hough transform to automatically identify microcalcifications that are highly correlated with breast cancer development in the early stages. Along with image processing, automatic segmentation of high-contrast objects is done using edge extraction and circle Hough transform. This provides the geometrical features needed for an automatic mask design which extracts statistical features of the regions of interest. The results shown in this study prove the potential of this tool for further diagnostics and classification of mammographic images due to the low sensitivity to noisy images and low contrast mammographies.

Keywords: breast cancer, segmentation, X-ray imaging, hough transform, image analysis

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Authors: Mathias B. Michael, Esther T. Akinlabi, Tien-Chien Jen

Abstract:

The current energy crisis in Ghana has affected significant number of industries which have direct impact on the country’s economy. Amongst the affected industries are palm oil production industries even though the impact is less as compared to fully relied national grid industries. Most of the large and medium palm oil production industries are partially grid reliance, however, the unavailability and the high cost palm biomass poses huge challenge. This paper aimed to identify and analyse the energy challenges associated with the palm oil production industries in Ghana. The study is conducted on the nine largest palm oil production plants in Ghana. Data is obtained by the use of questionnaire and observation. Since the study aimed to compare the respective energy challenges associated with nine industrial plants under study and establish a benchmark that represents a common problem of all the nine plants under study, the study uses percentile analysis and Analysis of Variance (ANOVA) as the statistical tools to validate the benchmark. The results indicate that lack of sustainability of palm biomass supply chain is the key energy challenge in the palm oil production industries in Ghana. Other problems include intermittent power supply from the grid and the low boiler efficiency due to outmoded conversion technology of the boilers. The result also demonstrates that there are statistically significant differences between the technologies in different age groups in relation to technology conversion efficiency.

Keywords: palm biomass, steam supply, energy challenges, energy benchmark

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