Search results for: cyber space

Authors: Hamed Sanei, Mohammad Bagher Ayani

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Optimizations of Plate Heat Exchangers (PHS) have received great attention in the past decade. In this study, heat transfer and pressure drop coefficients are compared for rectangular and circular PHS employing numerical simulations. Plates are designed to have equivalent areas. Simulations were implemented to investigate the efficiency of PHSs considering heat transfer, friction factor and pressure drop. Amount of heat transfer and pressure drop was obtained for different range of Reynolds numbers. These two parameters were compared with aim of F "weighting factor correlation". In this comparison, the minimum amount of F indicates higher efficiency. Results reveal that the F value for rectangular shape is less than circular plate, and hence using rectangular shape of PHS is more efficient than circular one. It was observed that, the amount of friction factor is correlated to the Reynolds numbers, such that friction factor decreased in both rectangular and circular plates with an increase in Reynolds number. Furthermore, such simulations revealed that the amount of heat transfer in rectangular plate is more than circular plate for different range of Reynolds numbers. The difference is more distinct for higher Reynolds number. However, amount of pressure drop in circular plate is less than rectangular plate for the same range of Reynolds numbers which is considered as a negative point for rectangular plate efficiency. It can be concluded that, while rectangular PHSs occupy more space than circular plate, the efficiency of rectangular plate is higher.

Keywords: Chevron corrugated plate heat exchanger, heat transfer, friction factor, Reynolds numbers

Procedia PDF Downloads 280

Authors: M. Talebzadegan, S. Bina, I. Riazi

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The purpose of this paper is to present an active solar energy system to supply heating demands of the teaching staff dormitory of the Islamic Azad University of Ramhormoz. The design takes into account the solar radiations and climate data of Ramhormoz town and is based on the daily warm water consumption for health demands of 450 residents of the dormitory, which is equal to 27000 lit of 50-C° water, and building heating requirements with an area of 3500 m² well-protected by heatproof materials. First, heating demands of the building were calculated, then a hybrid system made up of solar and fossil energies was developed and finally, the design was economically evaluated. Since there is only roof space for using 110 flat solar water heaters, the calculations were made to hybridize solar water heating system with heat pumping system in which solar energy contributes 67% of the heat generated. According to calculations, the net present value “N.P.V.” of revenue stream exceeds “N.P.V.” of cash paid off in this project over three years, which makes economically quite promising. The return of investment and payback period of the project is 4 years. Also, the internal rate of return (IRR) of the project was 25%, which exceeds bank rate of interest in Iran and emphasizes the desirability of the project.

Keywords: Solar energy, Heat Demand, Renewable , Pollution

Procedia PDF Downloads 234

Authors: Kahlil Fredrick Cui, Marissa Pastor

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Earthquakes are complex phenomena, exhibiting complex correlations in space, time, and magnitude. Recently, the concept of complex networks has been used to shed light on the statistical and dynamical characteristics of regional seismicity. In this work, we study the relationships and interactions of seismic regions in Chile, Japan, and the Philippines through weighted and directed complex network analysis. Geographical areas are digitized into cells of fixed dimensions which in turn become the nodes of the network when an earthquake has occurred therein. Nodes are linked if a correlation exists between them as determined and measured by a correlation metric. The networks are found to be scale-free, exhibiting power-law behavior in the distributions of their different centrality measures: the in- and out-degree and the in- and out-strength. The evidence is also found of preferential interaction between seismically active regions through their degree-degree correlations suggesting that seismicity is dictated by the activity of a few active regions. The importance of a seismic region to the overall seismicity is measured using a generalized centrality metric taken to be an indicator of its activity or passivity. The spatial distribution of earthquake activity indicates the areas where strong earthquakes have occurred in the past while the passivity distribution points toward the likely locations an earthquake would occur whenever another one happens elsewhere. Finally, we propose a method that would project the location of the next possible earthquake using the generalized centralities coupled with correlations calculated between the latest earthquakes and a geographical point in the future.

Keywords: complex networks, correlations, earthquake, hazard assessment

Procedia PDF Downloads 189

Authors: Z. Chen, C. S. Poon

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In Hong Kong, about 1,000 tonnes of sewage sludge were produced every day in 2014 representing a major fraction of the total solid municipal waste. Traditionally, sewage sludge is disposed of at landfills. This disposal method causes environmental issues and uses up precious space in landfills which are becoming saturated one by one. To tackle the disposal problem, Hong Kong government has just built a sewage sludge incinerator. Through incineration the volume of waste can be reduced up to 90% by converting sewage sludge into ash. Whilst sewage sludge ash (SSA) still needs to be disposed of at landfills, research has been conducted at the Hong Kong Polytechnic University on using SSA to substitute cement for the production of construction materials. Results demonstrated that SSA contained many open and isolated pores and thus can reduce the cement dilution effect resulting in only slight decrease in the flexural and compressive strengths of cement mortar. The incorporation of SSA in cement mortar can be up to 20% of the binder, without too much worry about adverse effect on strength development of mortar. There was some enhancement in strength using ground SSA in comparison to the original SSA. The original SSA shortened the relative initial setting time of cement paste but ground SSA caused slight delay in the setting of cement paste. The research also found that increasing the percentage of SSA lead to decreasing workability of cement mortar with the same water/binder ratio, and ground SSA was beneficial to workability although grinding increased the surface area of SSA. This paper summarizes the major findings of the research.

Keywords: cement replacement, construction material, sewage sludge ash, waste recycling

Procedia PDF Downloads 369

Authors: A. Chari, A. El Bouari, B. Orayech, A. Faik, J. M. Igartua

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The phosphate is a natural resource of great importance in Morocco. In order to exploit this wealth, synthesis and studies of new a material based phosphate, were carried out. The apatite structure present o lot of characteristics, One of the main characteristics is to allow large and various substitutions for both cations and anions. Beside their biological importance in hard tissue (bone and teeth), apatites have been extensively studied for their potential use as fluorescent lamp phosphors or laser host materials.The apatite have interesting possible application fields such as in medicine as materials of bone filling, coating of dental implants, agro chemicals as artificial fertilizers. The LiPb2Ca2(PO4)3 was synthesized by the solid-state method, its crystal structure was investigated by Rietveld analysis using XRPD data. This material crystallizes with a structure of lacunar apatite anion deficit. The LiPb2Ca2(PO4)3 is hexagonal apatite at room temperature, adopting the space group P63/m (ITA No. 176), Rietveld refinements showed that the site 4f is shared by three cations Ca, Pb and Li. While the 6h is occupied by the Pb and Li cations. The structure can be described as built up from the PO4 tetrahedra and the sixfold coordination cavities, which delimit hexagonal tunnels along the c-axis direction. These tunnels are linked by the cations occupying the 4 f sites. Raman and Infrared spectroscopy analyses were carried out. The observed frequencies were assigned and discussed on the basis of unit-cell group analysis and by comparison to other apatite-type materials.

Keywords: apatite, Lacunar, crystal structure, Rietveldmethod, LiPb2Ca2(PO4)3, Phase transition

Procedia PDF Downloads 381

Authors: Chien-Yeh Hsu, Yuan-Ching Chiang, Zi-Jie Chien, Sih-Li Chen

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In this study, a field experiment and performance analysis of air-tunnel heat exchanger integrated with water-filled raft foundation of residential building were performed. In order to obtain better performance, conventional applications of air-tunnel inevitably have high initial cost or issues about insufficient installation space. To improve the feasibility of air tunnel heat exchanger in high-density housing, an integrated system consisting of air pipes immersed in the water-filled raft foundation was presented, taking advantage of immense amount of water and relatively stable temperature in raft foundation of building. The foundation-integrated air tunnel was applied to a residential building located in Yilan, Taiwan, and its thermal performance was measured in the field experiment. The results indicated that the cooling potential of integrated system was close to the potential of soil-based EAHE at 2 m depth or deeper. An analytical model based on thermal resistance method was validated by measurement results, and was used to carry out the dimensioning of foundation-integrated air tunnel. The discrepancies between calculated value and measured data were less than 2.7%. In addition, the return-on-investment with regard to thermal performance and economics of the application was evaluated. Because the installation for air tunnel is scheduled in the building foundation construction, the utilization of integrated system spends less construction cost compare to the conventional earth-air tunnel.

Keywords: air tunnel, ground heat exchanger, raft foundation, residential building

Procedia PDF Downloads 303

Authors: Luciano E. Sewaybricker

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Psychology has faced many challenges in order to claim its right to study happiness. Probably the major issue has been to present a clear definition of happiness, which has a long history outside the scientific field and has been used imprecisely in the daily life. Even after years of great improvement, different meanings of happiness still have been seen in academic studies. This scenario allows to question if any definition is consistent enough to sustain the recent findings of the psychological processes behind happiness. Moreover, does it make sense to seek a single definition of happiness? By investigating the history of happiness and the theoretical foundations of Positive Psychology, it can be advocated that it’s proper for happiness to be polysemic. Since Ancient Greece most attempts to outline happiness consists of an appreciation of the "best way to live" and consequently requires a delineation of the most important things in life. Besides this generic definition, it’s hard to find consensus about happiness. In fact, what and how much something will be considered important to happiness depend on social influence. This compels happiness to vary between groups, historical periods, and even for the same person over time. Therefore, the same psychological processes will not necessarily be behind all forms of happiness. Consequently, three assumptions should be considered when studying happiness: it’s intrinsic of happiness to be transitory and socially influenced; happiness refers not only to what is possible in the present, but also to an ideal future; when someone (including a scientist) talks about happiness they describe and prescribe a better way to live. Because any attempt to define happiness will be limited in space and time, it's more suitable to study its variations than its universalities. This may have considerable consequences to political agenda on happiness evaluation and maximization, like Gross National Happiness and utilitarian initiatives. Happiness policies should be understood as an arbitrary choice amongst all kinds of happiness and as prescriptive of what “the best way to live” should be.

Keywords: happiness, politics, positive psychology, well-being

Procedia PDF Downloads 241

Authors: Khadidja Rahmani, Nahla Bouaziz

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The climate change and the economic crisis, which are currently running, are the origin of the emergence of many issues and problems, which are related to the domain of energy and environment in à direct or indirect manner. Since the urban space is the core element and the key to solve the current problem, particular attention is given to it in this study. For this reason, we rented to the later a very particular attention; this is for the opportunities that it provides and that can be invested to attenuate a little this situation, which is disastrous and worried, especially in the face of the requirements of sustainable development. Indeed, the purpose of this work is to develop a method, which will allow us to guide designers towards projects with a certain degree of thermo-aeraulic comfort while requiring a minimum energy consumption. In this context, the architects, the urban planners and the engineers (energeticians) have to collaborate jointly to establish a method based on indicators for the improvement of the urban environmental quality (aeraulic-thermo comfort), correlated with a reduction in the energy demand of the entities that make up this environment, in areas with a sub-humid climate. In order to test the feasibility and to validate the method developed in this work, we carried out a series of simulations using computer-based simulation. This research allows us to evaluate the impact of the use of the indicators in the design of the urban sets, on the economic and ecological plan. Using this method, we prove that an urban design, which carefully considered energetically, can contribute significantly to the preservation of the environment and the reduction of the consumption of energy.

Keywords: comfort, energy consumption, energy mastery, morpho-energetic indicators, simulation, sub-humid climate, urban sets

Procedia PDF Downloads 255

Authors: Priyansha Sharma, Sibani Mund, Sivakumar Vaidyanathan

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Solid-state synthesis methods were used for the synthesis of pure red emissive Li¬3BaSrxCa(1-x)Eu2.7Gd0.3(MoO4)8 (x = 0.0 to 1.0) phosphors, XRD, SEM, and FTIR spectra were used to characterize the materials, and their optical properties were thoroughly investigated. PL studies were examined at different excitations 230 nm, 275nm, 465nm, and 395 nm. All the spectra show similar emissions with the highest transition at 616 nm due to ED transition. The given phosphor Li¬3BaSr0.25Ca0.75Eu2.7Gd0.3(MoO4)8 shows the highest intensity and is thus chosen for the temperature-dependent and Quantum yield study. According to the PL investigation, the phosphor-containing Eu3+ emits red light due to the (5D0 7F2) transition. The excitation analysis shows that all of the Eu3+ activated phosphors exhibited broad absorption due to the charge transfer band, O2-Mo6+, O2-Eu3+ transition, as well as narrow absorption bands related to the Eu3+ ion's 4f-4f electronic transition. Excitation spectra show Charge transfer band at 275 nm shows the highest intensity. The primary band in the spectra refers to Eu3+ ions occupying the lattice's non-centrosymmetric location. All of the compositions are monoclinic crystal structures with space group C2/c and match with reference powder patterns. The thermal stability of the 3BaSr0.25Ca0.75Eu2.7Gd0.3(MoO4)8 phosphor was investigated at (300 k- 500 K) as well as at low temperature from (20 K to 275 K) to be utilized for red and white LED fabrication. The Decay Lifetime of all the phosphor was measured. The best phosphor was used for White and Red LED fabrication.

Keywords: PL, phosphor, quantum yield, white LED

Procedia PDF Downloads 48

Authors: Haitao Yang, Jianming Lv, Fei Xu, Xintong Wang, Yilin Huang, Lanting Xia, Xuewu Zhu

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Given a fixed fund, purchasing fewer hosts of higher capability or inversely more of lower capability is a must-be-made trade-off in practices for building a Hadoop big data platform. An exploratory study is presented for a Housing Big Data Platform project (HBDP), where typical big data computing is with SQL queries of aggregate, join, and space-time condition selections executed upon massive data from more than 10 million housing units. In HBDP, an empirical formula was introduced to predict the performance of host clusters potential for the intended typical big data computing, and it was shaped via a regression approach. With this empirical formula, it is easy to suggest an optimal cluster configuration. The investigation was based on a typical Hadoop computing ecosystem HDFS+Hive+Spark. A proper metric was raised to measure the performance of Hadoop clusters in HBDP, which was tested and compared with its predicted counterpart, on executing three kinds of typical SQL query tasks. Tests were conducted with respect to factors of CPU benchmark, memory size, virtual host division, and the number of element physical host in cluster. The research has been applied to practical cluster procurement for housing big data computing.

Keywords: Hadoop platform planning, optimal cluster scheme at fixed-fund, performance predicting formula, typical SQL query tasks

Procedia PDF Downloads 213

Authors: C. Akhras

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Change is the life blood of business. Dynamic factors inspire change yet may act as barriers, influencing the company’s position in the market and challenging its organizational mission and culture. Today, the business context has globalized with business enterprises in the North and South joint in mergers and the East forges a strategic alliance with the West. Moreover, given that very little remains stable in certain industries, national business goals in the millennial marketplaces might be rapid, accelerated, and differentiated growth while distinctive competitive advantage might mark new qualitative excellence in others. In a new age culture marked by change, organizations, leaders, and followers are impacted; indigenous business leaders seem to have a very important role to play in change management. This case study was carried out on 178 business employees employed in local industry to evaluate perceptions of indigenous business leadership, workplace assessment, and organizational change management in the Middle East and North Africa. Three research questions were posed: (1) In your work context, do you think business leaders are essentially changing agents? (2) In your work context, is workplace change more effective in business leaders perceived as a hierarchical change agent rather than those perceived as an empowering change agent? (3) In your work context, is workplace change more efficient in business leaders perceived as a hierarchical change agent rather than those perceived as an empowering change agent? The results of the study and its limitations imposed by time and space indicate that more comprehensive research is required in this area.

Keywords: catalyst, change management, business enterprise, workplace assessment

Procedia PDF Downloads 269

Authors: Oluwlola Felicia Kikelomo

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This study examined the influence of Tertiary Education Trust Fund (TETF) intervention projects and resource utilization in universities in South Western State of Nigeria. The study was a descriptive design of the correlation type. Purposive sampling technique was used to select six out of 14 beneficiary universities in the States. Instruments used to collect data were TETF Intervention Projects Checklist (TETFIPC), Educational Facilities Checklists (EFC) and Resources Utilization Checklists (RUC). The research questions raised were answered using percentage and utilization rates, while Pearson product-moment correlation statistic was used to test the hypotheses formulated to guide the study 0.05 level of significance. Findings of the study indicated that building construction had the highest TETF allocation (64.5%), while staff development opportunities had the least (1.1%) in the sampled universities. Significant and positive relationship existed between time and space utilization rates and student academic performance in the universities (r (1,800) = 0.63 and r (1,800) = 0.59, p ≤ 0.05 respectively). Based, on these findings, it was recommended that there should be periodic evaluation of completed TETF projects and utilization to ensure that TETF funds are properly used for the approved projects; and that TETF should improve on the provision of educational facilities to universities for staff and students’ use through increase in education tax from 2% to 4% with collaboration with the world bank and other funding agencies as being practiced in other countries of the world such as Norway, Spain, and United Kingdom.

Keywords: tertiary education trust fund, intervention, education, human development

Procedia PDF Downloads 358

Authors: Saimir Heta, Kers Kapaj, Rialda Xhizdari, Ilma Robo

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Dealing with emerging cases of dental malpractice with justifications that stem from the clear rules of dental ethics is a phenomenon with an increasing trend in today's dental practice. Dentists should clearly understand how far the limit of malpractice goes, with or without minimal or major consequences, for the affected patient, which can be justified as a complication of dental treatment, in support of the rules of dental ethics in the dental office. Indeed, malpractice can occur in cases of lack of professionalism, but it can also come as a consequence of anatomical and physiological limitations in the implementation of the dental protocols, predetermined and indicated by the patient in the paragraph of the treatment plan in his personal card. This study is of the review type with the aim of the latest findings published in the literature about the problem of dealing with these phenomena. The combination of keywords is done in such a way with the aim to give the necessary space for collecting the right information in the networks of publications about this field, always first from the point of view of the dentist and not from that of the lawyer or jurist. From the findings included in this article, it was noticed the diversity of approaches towards the phenomenon depends on the different countries based on the legal basis that these countries have. There is a lack of or a small number of articles that touch on this topic, and these articles are presented with a limited number of data on the same topic. Conclusions: Dental malpractice should not be hidden under the guise of various dental complications that we justify with the strict rules of ethics for patients treated in the dental chair. The individual experience of dental malpractice must be published with the aim of serving as a source of experience for future generations of dentists.

Keywords: dental ethics, malpractice, professional protocol, random deviation

Procedia PDF Downloads 69

Authors: Kumud Singh, Janvin Itteera, Priti Ukarde, Sanjay Malhotra, P. PMarathe, Ayan Bandyopadhay, Rakesh Meena, Vikram Rawat, L. M. Joshi

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Application of Permanent magnet technology to high frequency miniature klystron tubes to be utilized for space applications improves the efficiency and operational reliability of these tubes. But nevertheless the task of generating magnetic focusing forces to eliminate beam divergence once the beam crosses the electrostatic focusing regime and enters the drift region in the RF section of the tube throws several challenges. Building a high quality magnet focusing lens to meet beam optics requirement in cathode gun and RF interaction region is considered to be one of the critical issues for these high frequency miniature tubes. In this paper, electromagnetic design and particle trajectory studies in combined electric and magnetic field for optimizing the magnetic circuit using 3D finite element method (FEM) analysis software is presented. A rectangular configuration of the magnet was constructed to accommodate apertures for input and output waveguide sections and facilitate coupling of electromagnetic fields into the input klystron cavity and out from output klystron cavity through coupling loops. Prototype lenses have been built and have been tested after integration with the klystron tube. We discuss the design requirements and challenges, and the results from beam transmission of the prototype lens.

Keywords: beam transmission, Brillouin, confined flow, miniature klystron

Procedia PDF Downloads 423

Authors: Chong Zhang, Guoming Tang, Bin Ge, Jiuyang Tang

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With the fast growing road traffic and increasingly severe traffic congestion, more and more citizens choose to use the public transportation for daily travelling. Meanwhile, the shared bike provides a convenient option for the first and last mile to the public transit. As of 2016, over one thousand cities around the world have deployed the bike-sharing system. The combination of these two transportations have stimulated the development of each other and made significant contribution to the reduction of carbon footprint. A lot of work has been done on mining the riding behaviors in various bike-sharing systems. Most of them, however, treated the bike-sharing system as an isolated system and thus their results provide little reference for the public transit construction and optimization. In this work, we treat the bike-sharing and public transit as a whole and investigate the customers’ bike-and-ride behaviors. Specifically, we develop a spatio-temporal traffic delivery model to study the riding patterns between the two transportation systems and explore the traffic characteristics (e.g., distributions of customer arrival/departure and traffic peak hours) from the time and space dimensions. During the model construction and evaluation, we make use of large open datasets from real-world bike-sharing systems (the CitiBike in New York, GoBike in San Francisco and BIXI in Montreal) along with corresponding public transit information. The developed two-dimension traffic model, as well as the mined bike-and-ride behaviors, can provide great help to the deployment of next-generation intelligent transportation systems.

Keywords: riding pattern mining, bike-sharing system, public transportation, bike-and-ride behavior

Procedia PDF Downloads 751

Authors: Zakiul Fuady, Ismail AB, Fauzi, Zulfian

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This research was conducted to analyze the absorption coefficients of sound at several types of materials as well as its combinations. The aim of this research was to find the value of sound absorption coefficients on the materials and its combinations. The materials used in this research were gypsum panel, gypsum-fibre palm, fibre palm-gypsum, and foamed concrete-fibre palm. The test was conducted by using a method of reverberation chamber based on the ISO 354-1985 with the types of the sound source: white noise and pink noise at the frequency of 125 Hz - 8000 Hz. Based on the test results of white noise, it was found that the panel of gypsum-fibre palm has α = 0.93 at low frequency; the panel of fibre palm has α = 0.97 at a medium frequency; and the panel of foamed concrete-fibre palm has α = 0.89 at high frequency. Further, for the sound source of pink noise, it was found that the panel of gypsum-fibre palm has α = 0.99 at low level; the panel of fibre palm-gypsum has α = 0.86 at medium level; and the panel of fibre palm-gypsum has α = 0.64 at high level. The fibre palm panel could absorb the sounds well since this material has bigger airspace (pore) than the foamed concrete and gypsum. Consequently, when the sounds wave enters to this material it will be trapped in the space. The panel of fibre palm affected an increasing of sound absorption coefficient value at the combination materials when the panel of fibre palm was placed under another panel. However, the absorption coefficient values of both fibre palm and fibre palm-gypsum panels are about the same.

Keywords: coefficient of sound absorption, pink noise, white noise, palm

Procedia PDF Downloads 230

Authors: Todd Zhou, Mikhail Yurochkin

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Out-of-distribution (OOD) detection is receiving increasing amounts of attention in the machine learning research community, boosted by recent technologies, such as autonomous driving and image processing. This newly-burgeoning field has called for the need for more effective and efficient methods for out-of-distribution generalization methods. Without accessing the label information, deploying machine learning models to out-of-distribution domains becomes extremely challenging since it is impossible to evaluate model performance on unseen domains. To tackle this out-of-distribution detection difficulty, we designed a model selection pipeline algorithm and developed a model selection framework with different impurity and randomness measurements to evaluate and choose the best-performing models for out-of-distribution data. By exploring different randomness scores based on predicted probabilities, we adopted the out-of-distribution entropy and developed a custom-designed score, ”CombinedScore,” as the evaluation criterion. This proposed score was created by adding labeled source information into the judging space of the uncertainty entropy score using harmonic mean. Furthermore, the prediction bias was explored through the equality of opportunity violation measurement. We also improved machine learning model performance through model calibration. The effectiveness of the framework with the proposed evaluation criteria was validated on the Folktables American Community Survey (ACS) datasets.

Keywords: model selection, domain generalization, model fairness, randomness measurements, bias index

Procedia PDF Downloads 107

Authors: Muhammad Abubakar Alhassan, Diane Pennington

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Social networking sites have become a space for people to discuss public health issues such as non-suicidal self-injury (NSSI). There are thousands of tweets containing self-harm and self-injury hashtags on Twitter. It is difficult to distinguish between different users who participate in self-injury discussions on Twitter and how their opinions change over time. Also, it is challenging to understand the topics surrounding NSSI discussions on Twitter. We retrieved tweets using #selfham and #selfinjury hashtags and investigated those from the United kingdom. We applied inductive coding and grouped tweeters into different categories. This study used the Latent Dirichlet Allocation (LDA) algorithm to infer the optimum number of topics that describes our corpus. Our findings revealed that many of those participating in NSSI discussions are non-professional users as opposed to medical experts and academics. Support organisations, medical teams, and academics were campaigning positively on rais-ing self-injury awareness and recovery. Using LDAvis visualisation technique, we selected the top 20 most relevant terms from each topic and interpreted the topics as; children and youth well-being, self-harm misjudgement, mental health awareness, school and mental health support and, suicide and mental-health issues. More than 50% of these topics were discussed in England compared to Scotland, Wales, Ireland and Northern Ireland. Our findings highlight the advantages of using the Twitter social network in tackling the problem of self-injury through awareness. There is a need to study the potential risks associated with the use of social networks among self-injurers.

Keywords: self-harm, non-suicidal self-injury, Twitter, social networks

Procedia PDF Downloads 110

Authors: Mai Anh Pham Ho

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Scarf products today is a symbol of fashion to decorate, to make our life more beautiful and bring new features to our living space. It also shows the cultural identity by using the traditional patterns that make easily to introduce the image of Vietnam to other nations all over the world. Therefore, the purpose of this research is to classify Vietnamese traditional patterns according to the era and dynasties. Vietnamese traditional patterns through the dynasties of Vietnamese history are done and classified by five groups of patterns including the geometric patterns, the natural patterns, the animal patterns, the floral patterns, and the character patterns in the Prehistoric times, the Bronze and Iron age, the Chinese domination, the Ngo-Dinh-TienLe-Ly-Tran-Ho dynasty, and the LeSo-Mac-LeTrinh-TaySon-Nguyen dynasty. Besides, there are some special kinds of Vietnamese traditional patterns like buffalo, lotus, bronze-drum, Phuc Loc Tho character, and so on. Extensive research was conducted for modernizing scarf collection applied Vietnamese traditional patterns which the fashion trend is used on creating works. The concept, target, image map, lifestyle map, motif, colours, arrangement and completion of patterns on scarf were set up. The scarf collection is designed and developed by the Adobe Illustrator program with three colour ways for each scarf. Upon completion of the research, digital printing technology is chosen for using on scarf collection which Vietnamese traditional patterns were researched deeply and widely with the purpose of establishment the basic background for Vietnamese culture in order to identify Vietnamese national personality as well as establish and preserve the cultural heritage.

Keywords: scarf collection, Vietnamese traditional patterns, printing methods, fabric design

Procedia PDF Downloads 325

Authors: Belal Mohamadi Kalesar, Raouf Hasanpour

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Proper placement of Distributed Generation (DG) units such as wind turbine generators in distribution system are still very challenging issue for obtaining their maximum potential benefits because inappropriate placement may increase the system losses. This paper proposes Particle Swarm Optimization (PSO) technique for optimal placement of wind based DG (WDG) in the primary distribution system to reduce energy losses and voltage profile improvement with four different wind levels modeling in year duration. Also, wind turbine is modeled as a DFIG that will be operated at unity power factor and only one wind turbine tower will be considered to install at each bus of network. Finally, proposed method will be implemented on widely used 69 bus power distribution system in MATLAB software environment under four scenario (without, one, two and three WDG units) and for capability test of implemented program it is supposed that all buses of standard system can be candidate for WDG installing (large search space), though this program can consider predetermined number of candidate location in WDG placement to model financial limitation of project. Obtained results illustrate that wind speed increasing in some months will increase output power generated but this can increase / decrease power loss in some wind level, also results show that it is required about 3MW WDG capacity to install in different buses but when this is distributed in overall network (more number of WDG) it can cause better solution from point of view of power loss and voltage profile.

Keywords: wind turbine, DG placement, wind levels effect, PSO algorithm

Procedia PDF Downloads 434

Authors: Alemayehu Ambaw, Matia Mukama, Umezuruike Linus Opara

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This study introduces a comprehensive method for designing ventilated corrugated fiberboard carton for fresh fruit packaging utilising virtual prototyping. The technique efficiently assesses and analyses the mechanical and thermal capabilities of fresh fruit packing boxes prior to making production investments. Comprehensive structural, aerodynamic, and thermodynamic data from designs were collected and evaluated in comparison to real-world packaging needs. Physical prototypes of potential designs were created and evaluated afterward. The virtual prototype is created with computer-aided graphics, computational structural dynamics, and computational fluid dynamics technologies. The virtual prototyping quickly generated data on carton compression strength, airflow resistance, produce cooling rate, spatiotemporal temperature, and product quality map in the cold chain within a few hours. Six distinct designs were analysed. All the various carton designs showed similar effectiveness in preserving the quality of the goods. The innovative packaging box design is more compact, resulting in a higher freight density of 1720 kg more fruit per reefer compared to the commercial counterpart. The precooling process was improved, resulting in a 17% increase in throughput and a 30% reduction in power usage.

Keywords: postharvest, container logistics, space/volume usage, computational method, packaging technology

Procedia PDF Downloads 37

Authors: J. B. Qin, X. H. Jiang, Y. T. Ge

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The growing awareness of global warming potential has internationally aroused interest and demand in reducing greenhouse gas emissions produced by human activity. Much national energy in the UK had been consumed in the residential sector mainly for space heating and domestic hot water production. Currently, gas boilers are mostly applied in the domestic water heating which contribute significantly to excessive CO₂ emissions and consumption of primary energy resources. The issues can be solved by popularizing heat pump systems that are attributable to higher performance efficiency than those of traditional gas boilers. Even so, the heat pump system performance can be further enhanced if the dissolved gases in its hot water circuit can be efficiently discharged.  To achieve this target, the bubble behaviors in the heat pump water heating system need to be extensively investigated. In this paper, by varying different experimental conditions, the effects of various heat pump hot water side parameters on gas microbubble diameters were measured and analyzed. Correspondingly, the effect of each parameter has been investigated. These include varied system pressures, water flow rates, saturation ratios and heat outputs. The results measurement showed that the water flow rate is the most significant parameter to influence on gas microbubble productions. The research outcomes can significantly contribute to the understanding of gas bubble behaviors at domestic heat pump water heating systems and thus the efficient way for the discharging of the associated dissolved gases.  

Keywords: heat pump water heating system, microbubble formation, dissolved gases in water, effectiveness

Procedia PDF Downloads 242

Authors: Ebert Brea

Abstract:

We propose a novel direct search algorithm for identifying at least a local minimum of mixed integer nonlinear unconstrained optimization problems. The Mixed Integer Randomized Pattern Search Algorithm (MIRPSA), so-called by the author, is based on a randomized pattern search, which is modified by the MIRPSA for finding at least a local minimum of our problem. The MIRPSA has two main operations over the randomized pattern search: moving operation and shrinking operation. Each operation is carried out by the algorithm when a set of conditions is held. The convergence properties of the MIRPSA is analyzed using a Markov chain approach, which is represented by an infinite countable set of state space λ, where each state d(q) is defined by a measure of the qth randomized pattern search Hq, for all q in N. According to the algorithm, when a moving operation is carried out on the qth randomized pattern search Hq, the MIRPSA holds its state. Meanwhile, if the MIRPSA carries out a shrinking operation over the qth randomized pattern search Hq, the algorithm will visit the next state, this is, a shrinking operation at the qth state causes a changing of the qth state into (q+1)th state. It is worthwhile pointing out that the MIRPSA never goes back to any visited states because the MIRPSA only visits any qth by shrinking operations. In this article, we describe the MIRPSA for mixed integer nonlinear unconstrained optimization problems for doing a deep study of its convergence properties using Markov chain viewpoint. We herein include a low dimension case for showing more details of the MIRPSA, when the algorithm is used for identifying the minimum of a mixed integer quadratic function. Besides, numerical examples are also shown in order to measure the performance of the MIRPSA.

Keywords: direct search, mixed integer optimization, random search, convergence, Markov chain

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Authors: Rania E. Ramadan

Abstract:

Dental esthetics is subjective, can be reported by the dentist and not noticed by the patient. However, if there is any imperfection seen by both the dentist and the patient, it is considered as an unesthetic like white and/or brown spot lesions. Many patients nowadays have been concerned about dental esthetics. Esthetic rehabilitation of anterior teeth and even maxillary premolars aid a lot in patients’ satisfaction of their smile consequently, gaining positive psychological impact for the patients. Many cases need esthetic rehabilitation such as diastema closure, spaced teeth and masking discolored teeth. Dental fluorosis and enamel hypo calcification can be presented as white and/or brown spot lesions. There are many treatment options for the management of these spotted teeth. Treatment options range from bleaching, microabrasion, direct composite restorations, porcelain veneers, and complete coverage crowns. The selection of certain options depends on many factors: the patient’s age, socioeconomic status and the severity of the lesion. In this clinical report, a 22-year-old male patient has been presented to the Department of Prosthodontics in Alexandria University, Egypt. His chief complaint was, “I was unpleased by white and brown spots in my teeth and I want to close the space between the two maxillary central.” Upon medical history, clinical examination, diagnostic photographs, and digital smile design by Exocad software, lithium disilicate veneers were chosen as the treatment of choice in maxillary anterior and first premolars.

Keywords: flourosis, ceramic veneers, case report, diastema closure

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Authors: N. Abbas, S. Lagomarsino, S. Cattari

Abstract:

Examining existing experimental results for shallow rigid foundations subjected to vertical centric load (N), accompanied or not with a bending moment (M), two main non-linear mechanisms governing the cyclic ‎response of the soil-foundation system can be distinguished: foundation uplift and soil yielding. A soil-foundation failure limit, is defined as a domain of resistance in the two dimensional (2D) load space (N, M) inside of which lie all the admissible combinations of loads; these latter correspond to a pure elastic, non-linear elastic or plastic behavior of the soil-foundation system, while the points lying on the failure limit correspond to a combination of loads leading to a failure of the soil-foundation system. In this study, the proposed resistance domain is constructed analytically based on mechanics. Original elastic limit, uplift initiation ‎limit and iso-uplift limits are constructed inside this domain. These limits give a prediction ‎of the mechanisms activated for each combination of loads applied to the ‎foundation. A comparison of the proposed failure limit with experimental tests existing in the literature shows interesting results. Also, the developed uplift initiation limit and iso-uplift curves are confronted with others already proposed in the literature and widely used due to the absence of other alternatives, and remarkable differences are noted, showing evident errors in the past proposals and relevant accuracy for those given in the present work.

Keywords: foundation uplift, iso-uplift curves, resistance domain, soil yield

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Authors: Alvaro Aguinaga, Carlos Avila, Edgar Cando

Abstract:

This article proposes a n-layer architecture, with a web client as a front-end, for the development of a virtual platform for process simulation on CNC machines. This Open-Source platform includes a CAD-CAM interface drawing primitives, and then used to furnish a CNC program that triggers a touch-screen virtual simulator. The objectives of this project are twofold. First one is an educational component that fosters new alternatives for the CAD-CAM/CNC learning process in undergrad and grade schools and technical and technological institutes emphasizing in the development of critical skills, discussion and collaborative work. The second objective puts together a research and technological component that will take the state of the art in CAD-CAM integration to a new level with the development of optimal algorithms and virtual platforms, on-line availability, that will pave the way for the long-term goal of this project, that is, to have a visible and active graduate school in Ecuador and a world wide Open-Innovation community in the area of CAD-CAM integration and operation of CNC machinery. The virtual platform, developed as a part of this study: (1) delivers improved training process of students, (2) creates a multidisciplinary team and a collaborative work space that will push the new generation of students to face future technological challenges, (3) implements industry standards for CAD/CAM, (4) presents a platform for the development of industrial applications. A protoype of this system was developed and implemented in a network of universities and technological institutes in Ecuador.

Keywords: CAD-CAM integration, virtual platforms, CNC machines, multi-layer based architecture

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Authors: Mohsen Azarmjoo, Yasaman Azarmjoo, Zahra Alikhani Koopaei

Abstract:

The increasing global population and continued growth in energy consumption underscore the need for renewable and sustainable energy sources more than ever. Soil batteries are a method for generating electrical energy by using recycled materials. Recycled materials include galvanized and copper sheets and recycled tires. Additionally, hydrogen, being a clean and efficient fuel, has the potential to replace fossil fuels. Consequently, hydrogen production from water presents a sustainable solution for energy supply. By utilizing aged materials, hydrogen production becomes more cost-effective and environmentally friendly. This article focuses on energy-deprived agricultural lands, explaining how soil batteries and hydrogen can provide the necessary energy for agricultural equipment, such as irrigation, lighting, greenhouse ventilation, and heating. The article explores the benefits of utilizing this method, emphasizing its potential to reduce environmental pollution through the use of recyclable materials. It is worth mentioning that these technologies face challenges, but their progress toward achieving zero-energy consumer standards positions them as promising future technologies for electricity generation. This article provides detailed insights into emerging technologies using a constructed case study involving soil batteries and a hydrogen fuel production device.

Keywords: electricity generation, soil batteries, tires, hydrogen, heat supply, water, aged materials, recycling, agricultural lands

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Authors: Ferit Çakıcı, M. Kemal Leblebicioğlu

Abstract:

In this study, characteristics and flight test analysis of a fixed-wing unmanned aerial vehicle (UAV) with hover capability is analyzed. The base platform is chosen as a conventional airplane with throttle, ailerons, elevator and rudder control surfaces, that inherently allows level flight. Then this aircraft is mechanically modified by the integration of vertical propellers as in multi rotors in order to provide hover capability. The aircraft is modeled using basic aerodynamical principles and linear models are constructed utilizing small perturbation theory for trim conditions. Flight characteristics are analyzed by benefiting from linear control theory’s state space approach. Distinctive features of the aircraft are discussed based on analysis results with comparison to conventional aircraft platform types. A hybrid control system is proposed in order to reveal unique flight characteristics. The main approach includes design of different controllers for different modes of operation and a hand-over logic that makes flight in an enlarged flight envelope viable. Simulation tests are performed on mathematical models that verify asserted algorithms. Flight tests conducted in real world revealed the applicability of the proposed methods in exploiting fixed-wing and rotary wing characteristics of the aircraft, which provide agility, survivability and functionality.

Keywords: flight test, flight characteristics, hybrid aircraft, unmanned aerial vehicle

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Authors: Liu Szu Yin

Abstract:

The center of urban development lies in commercial transactions and folk religious activities. In Taipei City, temples serve as crucial urban spaces and centers for civic activities and religious beliefs. The appearance of local temples can be influenced by the prosperity of the surrounding communities. Apart from being centers of religious worship, Taipei's temples also host festival celebrations, allowing people to gather in front of the temples and form collective urban memories. The spatial attributes for hosting festival activities include streets, squares, parks, and buildings. In Taipei, many traditional festivals take place on the streets, either as round-trip routes or linear routes with a single starting and ending point. Given the processions and parades involving palanquins and other ceremonial objects during traditional festival activities, street spaces are frequently utilized. Therefore, this study analyzes the historical context and street spaces of three traditional festivals in Taipei City, including Qingshan Temple in Monga, Xiahai City God Temple in Dadaocheng, and Baoan Temple in Dalongdong, through on-site research. Most urban festival planners need to understand the characteristics of the city's streets in order to effectively utilize street spaces for festival planning. Taipei's traditional festivals not only preserve Chinese traditional culture but also incorporate modern elements, ensuring the transmission of culture and faith and allowing the city to become characterized by sustainable culture and unique urban memories.

Keywords: festival space, urban festival, taipei, urban memory

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Authors: Brar Prabhdip

Abstract:

Art and fashion are coupled by a common bridge which is ‘Creativity’. For centuries art has influenced fashion and has been inspirational for modern-day national as well as international designers. Italian artists during the Renaissance period were highly influenced by art. 20th and 21st-century artists have often found themselves the muses of major fashion houses. Many times artists and designers like Andy Warhol, Damien Hirst, and Dior, Prada, respectively, have collaborated and successfully created prints, textiles, and silhouettes that have dazzled the art and fashion world. This paper nudges deeper and discourses the statement pieces of remarkable designers that have been influenced by art and adorned by international celebrities. Indian designer Manish Arora has been able to design a remarkable position for himself in the international fashion world. His clothes are avant-garde and favoured choice of celebrities like Lady Gaga and Katy Perry. The Manish Arora collaboration with Berlin-based artist Amrie Hoffstater has carved its space for a new segment. The latest collaboration, despite being in the pandemic, is between Sabyasachi (India) and Bergdorfs Goodman (New York). It boasts of the traditional Colonial Indian sensibility juxtaposed with the eclectic Western American mix for the new-age wearer. A qualitative and exploratory research design is steered towards both art and fashion as they reflect social, economic, and political changes. Social issues are highlighted through these platforms. Secondary data has been used for this paper to explain how designers have bridged the way for how one could wear fashion as a piece of art in and of itself. Conclusively we reach the perfect camaraderie between art and fashion.

Keywords: art, artist, collaboration, designer, fashion, relationship commas

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