Search results for: opti system simulation

Authors: Mohammadreza Akbari, Sara Akbari, Davood Domiri Ganji, Pooya Solimani, Reza Khalili

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As all experts know most of engineering system behavior in practical are nonlinear process (especially heat, fluid and mass, etc.) and analytical solving (no numeric) these problems are difficult, complex and sometimes impossible like (fluids and gas wave, these problems can't solve with numeric method, because of no have boundary condition) accordingly in this symposium we are going to exposure a innovative approach which we have named it Akbari-Ganji's Method or AGM in engineering, that can solve sets of coupled nonlinear differential equations (ODE, PDE) with high accuracy and simple solution and so this issue will be emerged after comparing the achieved solutions by Numerical method (Runge-Kutte 4th) and so compare to other methods such as HPM, ADM,… and exact solutions. Eventually, AGM method will be proved that could be created huge evolution for researchers, professors and students (engineering and basic science) in whole over the world, because of AGM coding system, so by using this software we can analytically solve all complicated linear and nonlinear differential equations, with help of that there is no difficulty for solving nonlinear differential equations(ODE and PDE). In this paper, we investigate and solve 4 types of the nonlinear differential equation with AGM method : 1-Heat and fluid, 2-Unsteady state of nonlinear partial differential, 3-Coupled nonlinear partial differential in wave equation, and 4-Nonlinear integro-differential equation.

Keywords: new method AGM, sets of coupled nonlinear equations at engineering field, waves equations, integro-differential, fluid and thermal

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Authors: Diane M. Bender

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In architecture and design education, students learn and understand their discipline through lecture courses and within studios. A studio is where the instructor works closely with students to help them understand design by doing design work. The final jury is the culmination of the studio learning experience. It’s value and significance are rarely questioned. Students present their work before their peers, instructors, and invited reviewers, known as jurors. These jurors are recognized experts who add a breadth of feedback to students mostly in the form of a verbal critique of the work. Since the design review or jury has been a common element of studio education for centuries, jurors themselves have been instructed in this format. Therefore, they understand its value from both a student and a juror perspective. To better understand how these reviewers see the value of a studio review, a survey was distributed to reviewers at a multi-disciplinary design school within the United States. Five design disciplines were involved in this case study: architecture, graphic design, industrial design, interior design, and landscape architecture. Respondents (n=108) provided written comments about their perceived value of the studio review system. The average respondent was male (64%), between 40-49 years of age, and has attained a master’s degree. Qualitative analysis with thematic coding revealed several themes. Reviewers view the final jury as important because it provides a variety of perspectives from unbiased external practitioners and prepares students for similar presentation challenges they will experience in professional practice. They also see it as a way to validate the assessment and evaluation of students by faculty. In addition, they see a personal benefit for themselves and their firm – the ability to network with fellow jurors, professors, and students (i.e., future colleagues). Respondents also provided additional feedback about the jury system and studio education in general. Typical responses included a desire for earlier engagement with students; a better explanation from the instructor about the project parameters, rubrics/grading, and guidelines for juror involvement; a way to balance giving encouraging feedback versus overly critical comments; and providing training for jurors prior to reviews. While this study focused on the studio review, the findings are equally applicable to other disciplines. Suggestions will be provided on how to improve the preparation of guests in the learning process and how their interaction can positively influence student engagement.

Keywords: assessment, design, jury, studio

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Authors: Tahsin Shameem, Chowdhury Sadman Jahan, Mohammad Alam

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Interest about Net Zero Energy Buildings have gained traction in recent years following the need to sustain energy consumption with generations on site and to reduce dependence on grid supplied energy from large plants using fossil fuel. With this end in view, building integrated photovoltaics are being studied attempting to utilize all exterior facades of a building to generate power. In this paper, we have looked at the physical parameters defining a dye sensitized solar cell (DSSC) and discussed their impact on energy harvest. Following our discussion and experimental data obtained from literature, we have attempted to optimize these physical parameters accordingly so as to allow maximum light absorption for a given active layer thickness. We then modified a planer DSSC design with our optimized properties to allow adequate light transmission which demonstrated a high fill factor and an External Quantum Efficiency (EQE) of greater than 9% by computer aided design and simulation. In conclusion, a DSSC based solar window with such high output values even after such high light transmission through it definitely flags a promising future for this technology and our work elicits the need for further study and practical experimentation.

Keywords: net zero energy building, integrated photovoltaics, dye sensitized solar cell, fill factor, External Quantum Efficiency

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Authors: Seyedvahid Najafi, Viliam Makis

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In recent years, maintenance optimization has attracted special attention due to the growth of industrial systems complexity. Maintenance costs are high for many systems, and preventive maintenance is effective when it increases operations' reliability and safety at a reduced cost. The novelty of this research is to consider general repair in the modeling of multi-unit series systems and solve the maintenance problem for such systems using the semi-Markov decision process (SMDP) framework. We propose an opportunistic maintenance policy for a series system composed of two main units. Unit 1, which is more expensive than unit 2, is subjected to condition monitoring, and its deterioration is modeled using a gamma process. Unit 1 hazard rate is estimated by the proportional hazards model (PHM), and two hazard rate control limits are considered as the thresholds of maintenance interventions for unit 1. Maintenance is performed on unit 2, considering an age control limit. The objective is to find the optimal control limits and minimize the long-run expected average cost per unit time. The proposed algorithm is applied to a numerical example to compare the effectiveness of the proposed policy (policy Ⅰ) with policy Ⅱ, which is similar to policy Ⅰ, but instead of general repair, replacement is performed. Results show that policy Ⅰ leads to lower average cost compared with policy Ⅱ. 

Keywords: condition-based maintenance, proportional hazards model, semi-Markov decision process, two-unit series systems

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Authors: Sugene Kim

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The English articles are taught as a binary system based on nominal countability and definiteness. Despite the detailed rules of prescriptive grammar, it has been consistently reported in the literature that their correct usage is extremely difficult to master even for advanced learners of English as a second language (ESL) or a foreign language (EFL). Given that an English sentence (except for an imperative) cannot be constructed without a noun, which is always paired with one of the indefinite, definite, and zero articles; it is essential to understand specifically what causes ESL/EFL learners to misuse them. To that end, this study examined EFL learners’ article use employing a one-group pre–post-test design. Forty-three Korean college students received instruction on correct English article usage for two 75-minute classes employing the binary schema set up for the study. They also practiced in class how to apply the rules as instructed. Then, the participants were assigned a forced-choice elicitation task, which was also used as a pre-test administered three months prior to the instruction. Unlike the pre-test on which they only chose the correct article for each of the 40 items, the post-instruction task additionally asked them to give written accounts of their decision-making procedure to choose the article as they did. The participants’ performance was scored manually by checking whether the answer given is correct or incorrect, and their written comments were first categorized using thematic analysis and then ranked by frequency. The analyses of the performance on the two tasks and the written think-aloud data suggested that EFL learners exhibit fluctuation between specificity and definiteness, overgeneralizing the use of the definite article for almost all cataphoric references. It was apparent that they have trouble distinguishing from the two concepts possibly because the former is almost never introduced in the grammar books or classes designed for ESL/EFL learners. Particularly, most participants were found to be ignorant of the possibility of using nouns as [+specific, –definite]. Not surprisingly, the correct answer rates for such nouns averaged out at 33% and 46% on the pre- and post-tests, respectively, which narrowly reach half the overall mean correct answer rates of 65% on the pre-test and 81% on the post-test. In addition, correct article use for specific indefinites was most impermeable to instruction when compared with nouns used as [–specific, –definite] or [± specific, +definite]. Such findings underline the necessity for expanding the binary schema to a ternary form that incorporates the specificity feature, albeit not morphologically marked in the English language.

Keywords: countability, definiteness, English articles, specificity, ternary system

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Authors: Babar Sultan, Kiran Sultan, Waseem Khan, Ijaz Mansoor Qureshi

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In this paper, a novel idea for the performance enhancement of secondary network is proposed for Underlay Cognitive Radio Networks (CRNs). In Underlay CRNs, primary users (PUs) impose strict interference constraints on the secondary users (SUs). The proposed scheme is based on Artificial Bee Colony (ABC) optimization for relay selection and power allocation to handle the highlighted primary challenge of Underlay CRNs. ABC is a simple, population-based optimization algorithm which attains global optimum solution by combining local search methods (Employed and Onlooker Bees) and global search methods (Scout Bees). The proposed two-phase relay selection and power allocation algorithm aims to maximize the signal-to-noise ratio (SNR) at the destination while operating in an underlying mode. The proposed algorithm has less computational complexity and its performance is verified through simulation results for a different number of potential relays, different interference threshold levels and different transmit power thresholds for the selected relays.

Keywords: artificial bee colony, underlay spectrum sharing, cognitive radio networks, amplify-and-forward

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Authors: Kaarunya Sampathkumar, Say Chye Joachim Loo

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Oral delivery is regarded as the facile method for the administration of active pharmaceutical ingredients (API) and drug carriers. In an initiative towards sustainable nanotechnology, an oral nano-delivery system has been developed that is made entirely of food-based materials and can also act as a site-specific delivery device depending on the stimulus encountered in different parts of the gastrointestinal tract (GIT). The delivery system has been fabricated from food grade polysaccharide materials like chitosan and starch through electrospraying technique without the use of any organic solvents. A nutraceutical extracted from an Indian medicinal plant, has been loaded into the nano carrier to test its efficacy in encapsulation and stimuli based release of the active ingredient. The release kinetics of the nutraceutical from the carrier was evaluated in simulated gastric, intestinal and colonic fluid and was found to be triggered both by the enzymes and the pH in each part of the intestinal tract depending on the polysaccharide being used. The toxicity of the nanoparticles on the intestinal epithelial cells was tested and found to be relatively safe for up to 24 hours at a concentration of 0.2 mg/mL with cellular uptake also being observed. The developed nano carrier thus serves as a promising delivery vehicle for targeted delivery to different parts of the GIT with the inherent conditions of the GIT itself acting as the stimulus. In addition, being fabricated from food grade materials, the carrier could be potentially used for the targeted delivery of nutrients through functional foods.

Keywords: bioavailability, chitosan, delivery systems, encapsulation

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Authors: Aslanova Aida Ramiz

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One of the important aspects of rheophysical problems in oil and gas extraction is the regulation of thermohydrodynamic properties of liquid systems using physical and physicochemical methods. It is known that the constituent parts of real fluid systems in oil and gas production are practically non-conducting, non-magnetically active components. Real heterogeneous hydrocarbon systems, from the structural point of view, consist of an infinite number of microscopic local ion-electrostatic cores distributed in the volume of the dispersion medium. According to Cohen's rule, double electric layers are formed at the contact boundaries of components in contact (oil-gas, oil-water, water-condensate, etc.) in a heterogeneous system, and as a result, each real fluid system can be represented as a complex composition of a set of local electrostatic fields. The electrokinetic properties of this structure are characterized by a certain electrode potential. Prof. F.H. Valiyev called this potential the α-factor and came up with the idea that many natural and technological rheophysical processes (effects) are essentially electrokinetic in nature, and by changing the α-factor, it is possible to adjust the physical properties of real hydraulic systems, including thermohydrodynamic parameters. Based on this idea, extensive research work was conducted, and the possibility of reducing hydraulic resistances and improving rheological properties was experimentally discovered in real liquid systems by reducing the electrical potential with various physical and chemical methods.

Keywords: microcracked, electrode potential, hydraulic resistance, Newtonian fluid, rheophysical properties

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Authors: Nitika Sharma, Yogesh Jain

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Introduction: An efficient Information System helps in improving the service delivery as well provides the foundation for policy and regulation of other building blocks of Health System. Health care organizations require an integrated working of its various sub-systems. An efficient EMR software boosts the teamwork amongst the various sub-systems thereby resulting in improved service delivery. Although there has been a huge impetus to EMR under the Digital India initiative, it has still not been mandated in India. It is generally implemented in huge funded public or private healthcare organizations only. Objective: The study was conducted to understand the factors that lead to the successful adoption of an affordable EMR in the low level healthcare organization. It intended to understand the design of the EMR and address the solutions to the challenges faced in adoption of the EMR. Methodology: The study was conducted in a non-profit registered Healthcare organization that has been providing healthcare facilities to more than 2500 villages including certain areas that are difficult to access. The data was collected with help of field notes, in-depth interviews and participant observation. A total of 16 participants using the EMR from different departments were enrolled via purposive sampling technique. The participants included in the study were working in the organization before the implementation of the EMR system. The study was conducted in one month period from 25 June-20 July 2018. The Ethical approval was taken from the institute along with prior approval of the participants. Data analysis: A word document of more than 4000 words was obtained after transcribing and translating the answers of respondents. It was further analyzed by focused coding, a line by line review of the transcripts, underlining words, phrases or sentences that might suggest themes to do thematic narrative analysis. Results: Based on the answers the results were thematically grouped under four headings: 1. governance of organization, 2. architecture and design of the software, 3. features of the software, 4. challenges faced in adoption and the solutions to address them. It was inferred that the successful implementation was attributed to the easy and comprehensive design of the system which has facilitated not only easy data storage and retrieval but contributes in constructing a decision support system for the staff. Portability has lead to increased acceptance by physicians. The proper division of labor, increased efficiency of staff, incorporation of auto-correction features and facilitation of task shifting has lead to increased acceptance amongst the users of various departments. Geographical inhibitions, low computer literacy and high patient load were the major challenges faced during its implementation. Despite of dual efforts made both by the architects and administrators to combat these challenges, there are still certain ongoing challenges faced by organization. Conclusion: Whenever any new technology is adopted there are certain innovators, early adopters, late adopters and laggards. The same pattern was followed in adoption of this software. He challenges were overcome with joint efforts of organization administrators and users as well. Thereby this case study provides a framework of implementing similar systems in public sector of countries that are struggling for digitizing the healthcare in presence of crunch of human and financial resources.

Keywords: EMR, healthcare technology, e-health, EHR

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Authors: Sweta Pandey, Samridhi Dhyani, Susmita Chaudhuri

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Klebsiella pneumoniae bacteria is a global threat to human health due to an increase in multi-drug resistance among strains. The hypervirulent strains of Klebsiella pneumoniae is a major trouble due to their association with life-threatening infections in a healthy population. One of the major virulence factors of hyper virulent strains of Klebsiella pneumoniae is the T6SS (Type six secretary system) which is majorly involved in microbial antagonism and causes interaction with the host eukaryotic cells during infections. T6SS mediates some of the crucial factors for establishing infection by the bacteria, such as cell adherence, invasion, and subsequent in vivo colonisation. The antibacterial activity and the cell invasion property of the T6SS system is a major requirement for the establishment of K. pneumoniae infections within the gut. The T6SS can be an appropriate target for developing therapeutics. The T6SS consists of an inner tube comprising hexamers of Hcp (Haemolysin -regulated protein) protein, and at the top of this tube sits VgrG (Valine glycine repeat protein G); the tip of the machinery consists of PAAR domain containing proteins which act as a delivery system for bacterial effectors. For this study, immune response to recombinant VgrG protein was generated to establish this protein as a potential immunogen for the development of therapeutic leads. The immunogenicity of the selected protein was determined by predicting the B cell epitopes by the BCEP analysis tool. The gene sequence for multiple domains of VgrG protein (phage_base_V, T6SS_Vgr, DUF2345) was selected and cloned in pMAL vector in E. coli. The construct was subcloned and expressed as a fusion protein of 203 residue protein with mannose binding protein tag (MBP) to enhance solubility and purification of this protein. The purified recombinant VgrG fusion protein was used for mice immunisation. The antiserum showed reactivity with the recombinant VgrG in ELISA and western blot. The immunised mice were challenged with K. pneumoniae bacteria and showed bacterial clearance in immunised mice. The recombinant VgrG protein can further be used for studying downstream signalling of VgrG protein in mice during infection and for therapeutic MAb development to eradicate K. pneumoniae infections.

Keywords: immune response, Klebsiella pneumoniae, multi-drug resistance, recombinant protein expression, T6SS, VgrG

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Authors: Mohamed Amine El Hameur, Lyes Tarabet, Mahfoudh Cerdoun, Boubkr Zebiri, Giovanni Ferrara

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Due to the drastic environmental and energy regulations regarding the reduction of exhaust emissions and fuel consumption, added to the increasing demand for powerful performance, several automotive manufacturers are constantly obliged to redesign their existing products and/or develop novel powertrain techniques to respond to the aforementioned restrictions. In this aspect, an implemented approach is proposed in the present work to boost a 1.5 L, three-cylinder Diesel engine with a new turbocharger, based on 1D preliminary design codes, 3D design, and numerical assessment of a suitable radial turbine followed by an accurate selection procedure of an adequate centrifugal compressor. Furthermore, to investigate the effect of the turbine’s rotor position on the simulation convergence, stability, and calculation time; two combinations (rotor blade- volute) have been assessed. Consequently, significant results are obtained when comparing the original turbocharged engine and the new one at the engine’s full load and rated speed (@4500rpm) conditions. A maximum improvement in terms of brake-specific fuel consumption, thermal efficiency, total-to-static turbine efficiency, and total-to-total compressor efficiency equal 6.5% (corresponding to a decrease of 2.3 litre/hr in fuel consumption), 7%, 10.9%, and 19.9%, respectively.

Keywords: CFD investigation, engine boosting, turbine design, turbocharger, rotor blade positioning

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Authors: Manpreet Kaur, Amita Rani, Sanjay Kumar

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The Internet of Things (IoT), a cyber-physical paradigm, allows a large number of devices to connect and send the sensory data in the network simultaneously. This tremendous amount of data generated leads to very high network load consequently resulting in network congestion. It further amounts to frequent loss of useful information and depletion of significant amount of nodes’ energy. Therefore, there is a need to control congestion in IoT so as to prolong network lifetime and improve the quality of service (QoS). Hence, we propose a two-level clustering based routing algorithm considering congestion score and packet priority metrics that focus on minimizing the network congestion. In the proposed Priority based Congestion Control (PBCC) protocol the sensor nodes in IoT network form clusters that reduces the amount of traffic and the nodes are prioritized to emphasize important data. Simultaneously, a congestion score determines the occurrence of congestion at a particular node. The proposed protocol outperforms the existing Packet Discard Network Clustering (PDNC) protocol in terms of buffer size, packet transmission range, network region and number of nodes, under various simulation scenarios.

Keywords: internet of things, cyber-physical systems, congestion control, priority, transmission rate

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Authors: M. Kessi

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We investigated the effect of the magnetic field on carrier transport phenomena in the transistor channel region of Double-Gate Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). This explores the Lorentz force and basic physical properties of solids exposed to a constant external magnetic field. The magnetic field modulates the electrons and potential distribution in the case of silicon Tunnel FETs. This modulation shows up in the device's external electrical characteristics such as ON current (ION), subthreshold leakage current (IOF), the threshold voltage (VTH), the magneto-transconductance (gm) and the output magneto-conductance (gDS) of Tunnel FET. Moreover, the channel doping concentration and potential distribution are obtained using the numerical method by solving Poisson’s transport equation in 3D modules semiconductor magnetic sensors available in Silvaco TCAD tools. The numerical simulations of the magnetic nano-sensors are relatively new. In this work, we present the results of numerical simulations based on 3D magnetic sensors. The results show excellent accuracy comportment and good agreement compared with that obtained in the experimental study of MOSFETs technology.

Keywords: single-gate MOSFET, magnetic field, hall field, Lorentz force

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Authors: Y. Lu, L. Liu, J. Guo

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Monolayer graphene and dichaclogenide semiconductor materials attract extensive research interest for potential nanoelectronics applications. The ultimate scaling limit of double gate MoS2 Field-Effect-Transistors (FETs) with a monolayer thin body is examined and compared with ultra-thin-body Si FETs by using self-consistent quantum transport simulation in the presence of phonon scattering. Modelling of phonon scattering, quantum mechanical effects, and self-consistent electrostatics allows us to accurately assess the performance potential of monolayer MoS2 FETs. The results revealed that monolayer MoS2 FETs show 52% smaller Drain Induced Barrier Lowering (DIBL) and 13% Smaller Sub-Threshold Swing (SS) than 3 nm-thick-body Si FETs at a channel length of 10 nm with the same gating. With a requirement of SS<100mV/dec, the scaling limit of monolayer MoS2 FETs is assessed to be 5 nm, comparing with 8nm of the ultra-thin-body Si counterparts due to the monolayer thin body and higher effective mass which reduces direct source-to-drain tunnelling. By comparing with the ITRS target for high performance logic devices of 2023; double gate monolayer MoS2 FETs can fulfil the ITRS requirements.

Keywords: nanotransistors, monolayer 2D materials, quantum transport, scaling limit

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Authors: George Kyriakopoulos, Photini Pazartzis, Anthi Koskina, Crystalie Bourcha

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The need for securing safe access to and return from outer space, as well as ensuring the viability of outer space operations, maintains vivid the debate over the promotion of organization of space traffic through a Space Traffic Management System (STM). The proliferation of outer space activities in recent years as well as the dynamic emergence of the private sector has gradually resulted in a diverse universe of actors operating in outer space. The said developments created an increased adverse impact on outer space sustainability as the case of the growing number of space debris clearly demonstrates. The above landscape sustains considerable threats to outer space environment and its operators that need to be addressed by a combination of scientific-technological measures and regulatory interventions. In this context, recourse to recent technological advancements and, in particular, to Artificial Intelligence (AI) and machine learning systems, could achieve exponential results in promoting space traffic management with respect to collision avoidance as well as launch and re-entry procedures/phases. New technologies can support the prospects of a successful space traffic management system at an international scale by enabling, inter alia, timely, accurate and analytical processing of large data sets and rapid decision-making, more precise space debris identification and tracking and overall minimization of collision risks and reduction of operational costs. What is more, a significant part of space activities (i.e. launch and/or re-entry phase) takes place in airspace rather than in outer space, hence the overall discussion also involves the highly developed, both technically and legally, international (and national) Air Traffic Management System (ATM). Nonetheless, from a regulatory perspective, the use of AI for the purposes of space traffic management puts forward implications that merit particular attention. Key issues in this regard include the delimitation of AI-based activities as space activities, the designation of the applicable legal regime (international space or air law, national law), the assessment of the nature and extent of international legal obligations regarding space traffic coordination, as well as the appropriate liability regime applicable to AI-based technologies when operating for space traffic coordination, taking into particular consideration the dense regulatory developments at EU level. In addition, the prospects of institutionalizing international cooperation and promoting an international governance system, together with the challenges of establishment of a comprehensive international STM regime are revisited in the light of intervention of AI technologies. This paper aims at examining regulatory implications advanced by the use of AI technology in the context of space traffic management operations and its key correlating concepts (SSA, space debris mitigation) drawing in particular on international and regional considerations in the field of STM (e.g. UNCOPUOS, International Academy of Astronautics, European Space Agency, among other actors), the promising advancements of the EU approach to AI regulation and, last but not least, national approaches regarding the use of AI in the context of space traffic management, in toto. Acknowledgment: The present work was co-funded by the European Union and Greek national funds through the Operational Program "Human Resources Development, Education and Lifelong Learning " (NSRF 2014-2020), under the call "Supporting Researchers with an Emphasis on Young Researchers – Cycle B" (MIS: 5048145).

Keywords: artificial intelligence, space traffic management, space situational awareness, space debris

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Authors: Wondmyibza Tsegaye Bayou, Johannes C. Nonner, Joost Heijkers

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This study aimed to identify and estimate dynamic groundwater seepage rates using four comparative methods; the Darcian approach, the water balance approach, the tracer method, and modeling. The theoretical background to these methods is put together in this study. The methodology was applied to a case study area at Zegveld following the advice of the Water Board Stichtse Rijnlanden. Data collection has been from various offices and a field campaign in the winter of 2008/09. In this complex confining layer of the study area, the location of the phreatic groundwater table is at a shallow depth compared to the piezometric water level. Data were available for the model years 1989 to 2000 and winter 2008/09. The higher groundwater table shows predominately-downward seepage in the study area. Results of the study indicated that net recharge to the groundwater table (precipitation excess) and the ditch system are the principal sources for seepage across the complex confining layer. Especially in the summer season, the contribution from the ditches is significant. Water is supplied from River Meije through a pumping system to meet the ditches' water demand. The groundwater seepage rate was distributed unevenly throughout the study area at the nature reserve averaging 0.60 mm/day for the model years 1989 to 2000 and 0.70 mm/day for winter 2008/09. Due to data restrictions, the seepage rates were mainly determined based on the Darcian method. Furthermore, the water balance approach and the tracer methods are applied to compute the flow exchange within the ditch system. The site had various validated groundwater levels and vertical flow resistance data sources. The phreatic groundwater level map compared with TNO-DINO groundwater level data values overestimated the groundwater level depth by 28 cm. The hydraulic resistance values obtained based on the 3D geological map compared with the TNO-DINO data agreed with the model values before calibration. On the other hand, the calibrated model significantly underestimated the downward seepage in the area compared with the field-based computations following the Darcian approach.

Keywords: groundwater seepage, phreatic water table, piezometric water level, nature reserve, Zegveld, The Netherlands

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Authors: S. J. Addinell, A. F. Grabsch, P. D. Fawell, B. Evans

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The Deep Exploration Technologies Cooperative Research Centre (DET CRC) is researching and developing a new coiled tubing based greenfields mineral exploration drilling system utilising down-hole water-powered percussive drill tooling. This new drilling system is aimed at significantly reducing the costs associated with identifying mineral resource deposits beneath deep, barren cover. This system has shown superior rates of penetration in water-rich, hard rock formations at depths exceeding 500 metres. With fluid flow rates of up to 120 litres per minute at 200 bar operating pressure to energise the bottom hole tooling, excessive quantities of high quality drilling fluid (water) would be required for a prolonged drilling campaign. As a result, drilling fluid recovery and recycling has been identified as a necessary option to minimise costs and logistical effort. While the majority of the cuttings report as coarse particles, a significant fines fraction will typically also be present. To maximise tool life longevity, the percussive bottom hole assembly requires high quality fluid with minimal solids loading and any recycled fluid needs to have a solids cut point below 40 microns and a concentration less than 400 ppm before it can be used to reenergise the system. This paper presents experimental results obtained from the research program during laboratory and field testing of the prototype drilling system. A study of the morphological aspects of the cuttings generated during the percussive drilling process shows a strong power law relationship for particle size distributions. This data is critical in optimising solids control strategies and cuttings dewatering techniques. Optimisation of deployable solids control equipment is discussed and how the required centrate clarity was achieved in the presence of pyrite-rich metasediment cuttings. Key results were the successful pre-aggregation of fines through the selection and use of high molecular weight anionic polyacrylamide flocculants and the techniques developed for optimal dosing prior to scroll decanter centrifugation, thus keeping sub 40 micron solids loading within prescribed limits. Experiments on maximising fines capture in the presence of thixotropic drilling fluid additives (e.g. Xanthan gum and other biopolymers) are also discussed. As no core is produced during the drilling process, it is intended that the particle laden returned drilling fluid is used for top-of-hole geochemical and mineralogical assessment. A discussion is therefore presented on the biasing and latency of cuttings representivity by dewatering techniques, as well as the resulting detrimental effects on depth fidelity and accuracy. Data pertaining to the sample biasing with respect to geochemical signatures due to particle size distributions is presented and shows that, depending on the solids control and dewatering techniques used, it can have unwanted influence on top-of-hole analysis. Strategies are proposed to overcome these effects, improving sample quality. Successful solids control and cuttings dewatering for water-powered percussive drilling is presented, contributing towards the successful advancement of coiled tubing based greenfields mineral exploration.

Keywords: cuttings, dewatering, flocculation, percussive drilling, solids control

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Authors: Abid Ali Abid

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One-dimensional (1-D) particle-in-cell (PIC) electrostatic simulations are carried out to investigate the electrostatic waves, whose constituents are hot, cold and beam electrons in the background of motionless positive ions. In fact, the electrostatic modes excited are electron acoustic waves, beam driven waves as well as Langmuir waves. It is assessed that the relevant plasma parameters, for example, hot electron temperature, beam electron drift speed, and the electron beam density significantly modify the electrostatics wave's profiles. In the nonlinear stage, the wave-particle interaction becomes more evident and the waves have obtained its saturation level. Consequently, electrons become trapped in the waves and trapping vortices are clearly formed. Because of this trapping vortices and mixing of the electrons in phase space, finally, lead to electrons thermalization. It is observed that for the high-density value of the beam-electron, the solitary waves having a bipolar form of the electric field. These solitons are the nonlinear Brenstein-Greene and Kruskal wave mode that attributes the trapping of electrons potential well of phase-space hole. These examinations revealed that electrostatic waves have been exited in beam-plasma model and producing waves having broad-frequency ranges, which may clarify the broadband electrostatic noise (BEN) spectrum studied in the auroral zone.

Keywords: electron acoustic waves, trapping of cold electron, Langmuir waves, particle-in cell simulation

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Authors: Jiunde Lee, Meng-Yu Wun

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The present study attempted to explore how the range differences of ‘Geometric Field of Vision’ (GFOV) and differences in camera control in 3D simulation games, OMSI—The Bus Simulator of the 2013 PC version, affected players’ cognitive load, anxiety, and task performances. The study employed a between-subjects factorial experimental design. A total of 80 subjects completed experiment whose data were eligible for further analysis. The results of this study showed that in the difference of field of view, players had better task performances in a spacious view. Although cognitive resources consumed more of the players’ ‘mental demand,’ ‘physical demand’, and ‘temporal demand’, they had better performances in the experiment, and their anxiety was effectively reduced. On the other hand, in the narrow GFOV, players thought they spent more cognitive resources on ‘effort’ and ‘frustration degree,’ and had worse task performances, but it was not significant enough to reduce their anxiety. In terms of difference of camera control, players had worse performances since the fixed lens restricted their dexterous control. However, there was no significant difference in the players’ subjective cognitive resources or anxiety. The results further illustrated that task performances were affected by the interaction of GFOV and camera control.

Keywords: geometric field of view, camera lens, cognitive load, anxiety

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Authors: Layla Farhat, Mathieu Bardoux, Stéphane Longuemart, Ziad Herro, Abdelhak Hadj Sahraoui

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Electrocaloric (EC) effect refers to the isothermal entropy or adiabatic temperature changes of a dielectric material induced by an external electric field. This phenomenon has been largely ignored for application because only modest EC effects (2.6

Keywords: electrocaloric effect, thermoreflectance, ferroelectricity, cooling system

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Authors: Min-Woo Kim, Ok-Kyun Na, Jun-Ho Byun, Jong-Hwan Park, Seung-Hwa Yang, Joon-Hong Park, Young-Chul Park

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This study is focused on the comparative analysis and improvement to grasp the flow characteristic of the Anti-Splash Device located under the P/V Valve and new concept design models using the CFD analysis and Artificial Neural Network. The P/V valve located upper deck to solve the pressure rising and vacuum condition of inner tank of the liquid cargo ships occurred oil outflow accident by transverse and longitudinal sloshing force. Anti-Splash Device is fitted to improve and prevent this problem in the shipbuilding industry. But the oil outflow accidents are still reported by ship owners. Thus, four types of new design model are presented by study. Then, comparative analysis is conducted with new models and existing model. Mostly the key criterion of this problem is flux in the outlet of the Anti-Splash Device. Therefore, the flow and velocity are grasped by transient analysis. And then it decided optimum model and design parameters to develop model. Later, it needs to develop an Anti-Splash Device by Flow Test to get certification and verification using experiment equipment.

Keywords: anti-splash device, P/V valve, sloshing, artificial neural network

Procedia PDF Downloads 586

Authors: Amin Zabihinejad, Philippe Viarouge

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In this paper, a direct power control (DPC) strategies have been investigated in order to control a high power AC/DC converter with time variable load. This converter is composed of a three level three phase neutral point clamped (NPC) converter as rectifier and an H-bridge four quadrant current control converter. In the high power application, controller not only must adjust the desired outputs but also decrease the level of distortions which are injected to the network from the converter. Regarding this reason and nonlinearity of the power electronic converter, the conventional controllers cannot achieve appropriate responses. In this research, the precise mathematical analysis has been employed to design the appropriate controller in order to control the time variable load. A DPC controller has been proposed and simulated using Matlab/Simulink. In order to verify the simulation result, a real-time simulator- OPAL-RT- has been employed. In this paper, the dynamic response and stability of the high power NPC with variable load has been investigated and compared with conventional types using a real-time simulator. The results proved that the DPC controller is more stable and has more precise outputs in comparison with the conventional controller.

Keywords: direct power control, three level rectifier, real time simulator, high power application

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Authors: Mustafa Mutahari, Nao Sugiki, Kojiro Matsuo

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The four decades of war, lack of job opportunities, poverty, lack of services, and natural disasters in different provinces of Afghanistan have contributed to a rapid increase in the population of Kabul, the capital city of Afghanistan. Population census has not been conducted since 1979, the first and last population census in Afghanistan. However, according to population estimations by Afghan authorities, the population of Kabul has been estimated at more than 4 million people, whereas the city was designed for two million people. Although the major transport mode of Kabul residents is public transport, responsible authorities within the country failed to supply the required means of transportation systems for the city. Besides, informal resettlement, lack of intersection control devices, presence of illegal vendors on streets, presence of illegal and unstandardized on-street parking and bus stops, driver`s unprofessional behavior, weak traffic law enforcement, and blocked roads and sidewalks have contributed to the extreme traffic congestion of Kabul. In 2018, the government of Afghanistan approved the Kabul city Urban Design Framework (KUDF), a vision towards the future of Kabul, which provides strategies and design guidance at different scales to direct urban development. Considering traffic congestion of the city and its budget limitations, the KUDF proposes a BRT route network with seven lines to reduce the traffic congestion, and it is said to facilitate more than 50% of Kabul population to benefit from this service. Based on the KUDF, it is planned to increase the BRT mode share from 0% to 17% and later to 30% in medium and long-term planning scenarios, respectively. Therefore, a detailed research study is needed to evaluate the proposed system before the implementation stage starts. The integrated land-use transport model is an effective tool to evaluate the Kabul BRT because of its future assessment capabilities that take into account the interaction between land use and transportation. This research aims to analyze and evaluate the proposed BRT route network with the application of an integrated land-use and transportation model. The research estimates the population distribution and travel behavior of Kabul within small boundary scales. The actual road network and land-use detailed data of the city are used to perform the analysis. The BRT corridors are evaluated not only considering its impacts on the spatial interactions in the city`s transportation system but also on the spatial developments. Therefore, the BRT are evaluated with the scenarios of improving the Kabul transportation system based on the distribution of land-use or spatial developments, planned development typology and population distribution of the city. The impacts of the new improved transport system on the BRT network are analyzed and the BRT network is evaluated accordingly. In addition, the research also focuses on the spatial accessibility of BRT stops, corridors, and BRT line beneficiaries, and each BRT stop and corridor are evaluated in terms of both access and geographic coverage, as well.

Keywords: accessibility, BRT, integrated land-use and transport model, travel behavior, spatial development

Procedia PDF Downloads 211

Authors: Yang Song, Xiaojun Qiu

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Multilayer materials are applied to much acoustics area. Multilayer porous materials are dominant in room absorber. Multilayer viscoelastic materials are the basic parts in underwater absorption coating. In most cases, the one-way sound absorption performance of multilayer material is concentrated according to the sound source site. But the two-way sound absorption performance is also necessary to be known in some special cases which sound is produced in both sides of the material and the both sides especially might contact with different media. In this article, this kind of case was research. The multilayer material was composed of viscoelastic layer and steel plate and the porous layer. The two sides of multilayer material contact with water and air, respectively. A theory model was given to describe the sound propagation and impedance in multilayer absorption material. The two-way sound absorption properties of several multilayer materials were calculated whose two sides all contacted with different media. The calculated results showed that the difference of two-way sound absorption coefficients is obvious. The frequency, the relation of layers thickness and parameters of multilayer materials all have an influence on the two-way sound absorption coefficients. But the degrees of influence are varied. All these simulation results were analyzed in the article. It was obtained that two-way sound absorption at different frequencies can be promoted by optimizing the configuration parameters. This work will improve the performance of underwater sound absorption coating which can absorb incident sound from the water and reduce the noise radiation from inside space.

Keywords: different media, multilayer material, sound absorption coating, two-way sound absorption

Procedia PDF Downloads 537

Authors: Yuri Boiko, Ci Lin, Iluju Kiringa, Tet Yeap

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The performance of a BLDC motor controlled by the Kalman filter-based position-sensorless drive is studied in terms of its dependence on the system’s parameters' variations. The effects of system’s parameters changes on the dynamic behavior of state variables are verified. Simulated is a closed-loop control scheme with a Kalman filter in the feedback line. Distinguished are two separate data sampling modes in analyzing feedback output from the BLDC motor: (1) equal angular separation and (2) equal time intervals. In case (1), the data are collected via equal intervals Δθ of rotor’s angular position θᵢ, i.e., keeping Δθ=const. In case (2), the data collection time points tᵢ are separated by equal sampling time intervals Δt=const. Demonstrated are the effects of the parameters changes on the sensorless control flow, in particular, reduction of the torque ripples, switching spikes, torque load balancing. It is specifically shown that an efficient suppression of commutation induced torque ripples is achievable selection of the sampling rate in the Kalman filter settings above certain critical value. The computational cost of such suppression is shown to be higher for the motors with lower induction values of the windings.

Keywords: BLDC motor, Kalman filter, sensorless drive, state variables, torque ripples reduction, sampling rate

Procedia PDF Downloads 142

Authors: Yaxian Chen, Yeonhee Park

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Driven by evolving FDA recommendations, modern clinical trials demand innovative designs that strike a balance between statistical rigor and ethical considerations. Covariate-adjusted response-adaptive (CARA) designs bridge this gap by utilizing patient attributes and responses to skew treatment allocation in favor of the treatment that is best for an individual patient’s profile. However, existing CARA designs for survival outcomes often hinge on specific parametric models, constraining their applicability in clinical practice. In this article, we address this limitation by introducing a CARA design for survival outcomes (CARAS) based on the Cox model and a variance estimator. This method addresses issues of model misspecification and enhances the flexibility of the design. We also propose a group sequential overlapweighted log-rank test to preserve type I error rate in the context of group sequential trials using extensive simulation studies to demonstrate the clinical benefit, statistical efficiency, and robustness to model misspecification of the proposed method compared to traditional randomized controlled trial designs and response-adaptive randomization designs.

Keywords: cox model, log-rank test, optimal allocation ratio, overlap weight, survival outcome

Procedia PDF Downloads 58

Authors: Li Guoyou, Zhang Tao, Ji Wenzhan, Huo Liang, Lin Xiqiang, Zhang Nan

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The three dimensional (3D) printing technology has undergone rapid development in the last few years and it is possible to print engineering structures. 3D printing buildings use wastes from constructions, industries and mine tailings as “ink”, and mix it with property improved materials, such as cement, fiber etc. This paper presents a study of the Thermodynamic performance of 3D printed walls using cement and steel slag powder. Analyses the thermal simulation regarding 3D printed walls and solid brick wall by the way of the hot-box methods and the infrared technology, and the results were contrasted with theoretical calculation. The results show that the excellent thermodynamic performance of 3D printed concrete wall made it suitable as the partial materials for self-thermal insulation walls in residential buildings. The thermodynamic performance of 3D printed concrete walls depended on the density of materials, distribution of holes, and the filling materials. Decreasing the density of materials, increasing the number of holes or replacing the filling materials with foamed concrete could improve its thermodynamic performance significantly. The average of heat transfer coefficient and thermal inertia index of 3D printed steel slag powder concrete wall all better than the traditional solid brick wall with a thickness of 240mm.

Keywords: concrete, 3D printed walls, thermodynamic performance, steel slag powder

Procedia PDF Downloads 181

Authors: Souhila Boukli Hacene, Djamila Kherbouche, Abdelhak Chikhaoui

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In this work, we elucidate theoretically the effect of defects and temperature on the performance of the organic bulk heterojunction solar cell (BHJ) P3HT: PCBM. We have studied the influence of their parameters on cell characteristics. For this purpose, we used the effective medium model and the solar cell simulator (SCAPS) to model the characteristics of the solar cell. We also explore the transport of charge carriers in the device. It was assumed that the mixture is lightly p-type doped and that the band gap contains acceptor defects near the HOMO level with a Gaussian distribution of energy states at 100 and 50 meV. We varied defects density between 1012-1017 cm-3, from 1016 cm-3, a total decrease of the photovoltaic characteristics due to the increase of the non-radiative recombination can be noticed. Then we studied the effect of variation of the electron and the hole capture cross-section on the cell’s performance, we noticed that the cell obtains a better efficiency of about 3.6% for an electron capture cross section ≤ 10-15 cm2 and a hole capture cross section ≤ 10-19 cm2. On the other hand, we also varied the temperature between 120K and 400K. We observed that the temperature of the solar cell induces a noticeable effect on its voltage. While the effect of temperature on the solar cell current is negligible.

Keywords: organic solar cell, P3HT:PCBM, defects, temperature, SCAPS

Procedia PDF Downloads 83

Authors: Pello Alfonso-Muniozguren, Madeleine Bussemaker, Ralph Chadeesingh, Caryn Jones, David Oakley, Judy Lee, Devendra Saroj

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Current industrialized livestock agriculture is growing every year leading to an increase in the generation of wastewater that varies considerably in terms of organic content and microbial population. Therefore, suitable wastewater treatment methods are required to ensure the wastewater quality meet regulations before discharge. In the present study, a combined lab scale activated sludge-filtration-ozonation system was used to treat a pre-treated abattoir wastewater. A hydraulic retention time of 24 hours and a solid retention time of 13 days were used for the activated sludge process, followed by a filtration step (4-7 µm) and using ozone as tertiary treatment. An average reduction of 93% and 98% was achieved for Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD), respectively, obtaining final values of 128 mg/L COD and 12 mg/L BOD. For the Total Suspended Solids (TSS), the average reduction increased to 99% in the same system, reducing the final value down to 3 mg/L. Additionally, 98% reduction in Phosphorus (P) and a complete inactivation of Total Coliforms (TC) was obtained after 17 min ozonation time. For Total Viable Counts (TVC), a drastic reduction was observed with 30 min ozonation time (6 log inactivation) at an ozone dose of 71 mg O3/L. Overall, the combined process was sufficient to meet discharge requirements without further treatment for the measured parameters (COD, BOD, TSS, P, TC, and TVC).

Keywords: abattoir waste water, activated sludge, ozone, waste water treatment

Procedia PDF Downloads 271

Authors: Kalbende Krunal Ramesh

Abstract:

The Carbon Capture and Storage Technology (CCS) provides a veritable platform to bridge the gap between the seemingly irreconcilable twin global challenges of ensuring a secure, reliable and diversified energy supply and mitigating climate change by reducing atmospheric emissions of carbon dioxide. Making its proper regulatory policy and making it flexible for the government and private company by law to regulate, also exploring the opportunity in this sector is the main aim of this paper. India's total annual emissions was 1725 Mt CO2 in 2011, which comprises of 6% of total global emission. It is very important to control the greenhouse gas emission for the environment protection. This paper discusses the various regulatory policy and technology adopted by some of the countries for successful using CCS technology. The brief geology of sedimentary basins in India is studied, ranging from the category I to category IV and deep water and potential for mature technology in CCS is reviewed. Areas not suitable for CO2 storage using presently mature technologies were over viewed. CSS and Clean development mechanism was developed for India, considering the various aspects from research and development, project appraisal, approval and validation, implementation, monitoring and verification, carbon credit issued, cap and trade system and its storage potential. The opportunities in oil and gas operations, power sector, transport sector is discussed briefly.

Keywords: carbon credit issued, cap and trade system, carbon capture and storage technology, greenhouse gas

Procedia PDF Downloads 429