Search results for: combined sewer systems

Authors: M. J. Park, S. H. Lee, C. H. Lee, O. M. Kwon

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This paper investigates stability problem for linear systems of neutral type with time-varying delay. By constructing various Lyapunov-Krasovskii functional, and utilizing some mathematical techniques, the sufficient stability conditions for the systems are established in terms of linear matrix inequalities (LMIs), which can be easily solved by various effective optimization algorithms. Finally, some illustrative examples are given to show the effectiveness of the proposed criterion.

Keywords: neutral systems, time-delay, stability, Lyapnov method, LMI

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Authors: Elena A. Troubitsyna

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Designers of modern safety-critical control systems are increasingly relying on networking to provide the systems with advanced functionality and satisfy customer’s needs. However, networking nature of modern control systems also brings new technological challenges associated with ensuring system safety in the presence of openness and hence, potential security threats. In this paper, we propose a methodology that relies on systems-theoretic analysis to enable an integrated analysis of safety and security requirements of controlling software. We demonstrate how to create a safety case – a structured argument about system safety – with explicit representation of both safety and security goals. Our approach provides the designers with a systematic approach to analysing safety and security interdependencies while designing safety-critical control systems.

Keywords: controlling software, integrated analysis, security, safety-security co-engineering

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Authors: Sarah Elsayed Mohammed, Lamiaa Ahmed Ahmed, Mahmoud Mohammed Khattab

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Aim: The aim of the present study was to investigate whether combined nicorandil and bone marrow-derived mesenchymal stem cells (BMDMSC) treatment could offer an additional benefit in ameliorating isoproterenol (ISO)-induced heart failure in rats. Methods: ISO (85 and 170 mg/kg/day) was injected subcutaneously for 2 successive days, respectively. By day 3, electrocardiographic changes were recorded and serum was separated for determination of CK-MB level for confirmation of myocardial damage. Nicorandil (3 mg/kg/day) was then given orally with or without a single i.v. BMDMSC administration. Electrocardiography and echocardiography were recorded 2 weeks after beginning of treatment. Rats were then sacrificed and ventricles were isolated for estimation of vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) contents, caspase-3 activity as well as inducible nitric oxide synthase (iNOS) and connexin-43 protein expressions. Moreover, histological analysis of myocardial fibrosis was performed and cryosections were done for estimation of homing of BMDMSC. Results: ISO induced a significant increase in ventricles/body weight ratio, left ventricular end diastolic (LVEDD) and systolic dimensions (LVESD), ST segment and QRS duration. Moreover, myocardial fibrosis as well as VEGF, TNF-α and TGF-β contents were significantly increased. On the other hand, connexin-43 protein expression was significantly decreased, while caspase-3 and iNOS protein expressions were significantly increased. Combined therapy provided additional improvement compared to cell treatment alone towards reducing cardiac hypertrophy, fibrosis and inflammation. Furthermore, combined therapy induced significant increase in angiogenesis and BMDMSC homing and prevented ISO induced changes in iNOS, connexin-43 and caspase-3 protein expressions. Conclusion: Combined nicorandil/BMDMSC treatment was superior to BMDMSC alone towards preventing ISO-induced heart failure in rats.

Keywords: fibrosis, isoproterenol, mesenchymal stem cells, nicorandil

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Authors: Oyenike Eludoyin

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Extreme climate conditions are deviation from the norms and are capable of causing upsets in many important environmental parameter including disruption of water balance and air temperature balance. Studies have shown that extreme climate conditions can foretell disaster in regions with inadequate early warning systems. In this paper, we combined geographical information systems, statistics and social surveys to evaluate the physiologic indices [(Dewpoint Temperature (Td), Effective Temperature Index (ETI) and Relative Strain Index (RSI)] and extreme climate conditions in different parts of southwest Nigeria. This was with the view to assessing the nature and the impact of the conditions on the people and their coping strategies. The results indicate that minimum, mean and maximum temperatures were higher in 1960-1990 than 1991-2013 periods at most areas, and more than 80% of the people adapt to thermal stress by changing wear type or cloth, installing air conditioner and fan at home and/or work place and sleeping outside at certain period of the night and day. With respect to livelihoods, about 52% of the interviewed farmers indicated that too early rainfall, late rainfall, prolonged dryness after an initial rainfall, excessive rainfall and windstorms caused low crop yields. Main (76%) coping strategies were changing of planting dates, diversification of crops, and practices of mulching and intercropping. Government or institutional support was less than 20%.

Keywords: coping strategies, extreme climate, livelihoods, physiologic comfort

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Authors: Samir Kumar Pal

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Background: Targeted rapid degradation of bilirubin has the potential to thwart incipient bilirubin encephalopathy. Uncontrolled hyperbilirubinemia is a potential problem in developing countries, including India, because of the lack of reliable healthcare institutes for conventional phototherapy. In India, most of the rural subjects duel in the exchange limit during transport, leading to a risk of kernicterus when they arrive at the treatment centre. Thus, an alternative pharmaceutical agent is needed for the hours. Objective: Exploration of a distinct therapeutic strategy for the control of neonatal hyperbilirubinemia compared to conventional phototherapy in a clinical setting. Method: We synthesized, characterized and investigated a spinel-structured Manganese citrate nanocomplex (C-Mn₃O₄ NC, the nanodrug) along with conventional phototherapy in neonatal subjects. We have also observed BIND scores in order to assess neurological dysfunctions. Results: Our observational study clearly reveals that the rate of declination of bilirubin in neonatal subjects with nanodrug oral administration and phototherapy is faster compared to that in the case of phototherapy only. The associated neural dysfunctions were also found to be significantly lower in the case of combined therapy. Conclusion: This study demonstrates that combined therapy works better than conventional phototherapy only for the control of hyperbilirubinemia. We have observed that a significant portion of neonatal subjects requiring blood exchange has been prevented with the combined therapeutic strategy. Further compilation of a drug-safety-dossier is warranted to translate this novel therapeutic chemo preventive approach to clinical settings.

Keywords: nanodrug, nanoparticle, Neonatal hyperbilirubinemia, alternative to phototherapy, redox modulation, redox medicine

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Authors: Sareh Rajabi, Taha Anjamrooz, Salwa Bheiry

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The continuous increase in the world population, resource shortage and the warning of climate change cause various environmental and social issues to the world. Thus, sustainability concept is much needed nowadays. Organizations are progressively falling under strong worldwide pressure to integrate sustainability practices into their project decision-making development. Construction projects in the industry are amongst the most significant, since it is one of the biggest divisions and of main significance for the national economy and hence has a massive effect on the environment and society. So, it is important to discover approaches to incorporate sustainability into the management of those projects. This study presents a combined sustainability index of projects with sustainable transportation which has been formed as per a comprehensive literature review and survey study. Transportation systems enable the movement of goods and services worldwide, and it is leading to economic growth and creating jobs while creating negative impacts on the environment and society. This research is study to quantify the sustainability indicators, through 1) identifying the importance of sustainable transportation indicators that are based on the sustainable practices used for the construction projects and 2) measure the effectiveness of practices through these indicators on the three sustainable pillars. A total 26 sustainability indicators have been selected and grouped under each related sustainability pillars. A survey was used to collect the opinion about the sustainability indicators by a scoring system. A combined sustainability index considering three sustainable pillars can be helpful in evaluating the transportation sustainable practices of a project and making decisions regarding project selection. In addition to focus on the issue of financial resource allocation in a project selection, the decision-maker could take into account the sustainability as an important key in addition to the project’s return and risk. The purpose of this study is to measure the performance of transportation sustainability which allow companies to assess multiple projects selection. This is useful to decision makers to rank and focus more on future sustainable projects.

Keywords: sustainable transportation, transportation performances, sustainable indicators, sustainable construction practice, sustainability

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Authors: Yaya Gao, Bing Zhong, Yafeng Liu, Fei Chen

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Aim: The purpose of this study was to explore the difference between acellular dermal matrix (ADM) combined with anterolateral thigh (ALT) flap and ALT flap alone. Methods: HSCC patients were treated and divided into group A (ALT) and group B (ALT+ADM) between January 2014 and December 2018. We compared and analyzed the intraoperative information and postoperative outcomes of the patients. Results: There were 21 and 17 patients in group A and group B, respectively. The operation time, blood loss, defect size and anastomotic vessel selection showed no significant difference between two groups. The postoperative complications, including wound bleeding (n=0 vs. 1, p=0.459), wound dehiscence (n=0 vs. 1, p=0.459), wound infection (n=5vs.3, p=0.709), pharyngeal fistula (n=5vs.4, p=1.000) and hypoproteinemia (n=11 vs. 12, p=0.326) were comparable between the groups. Dysphagia at 6 months (number of liquid diets=0vs. 0; number of partial tube feedings=1vs. 1; number of total tube feedings=1vs. 0, p=0.655) also showed no significant differences. However, significant differences was observed in dysphagia at 12 months (number of liquid diets=0vs. 0; number of partial tube feedings=3 vs. 1; number of total tube feedings=10vs. 1, p=0.006). Conclusion: For HSCC patients, the use of the ALT flap combined ADM, compared to ALT treatment, showed better swallowing function at 12 months. The ALT flap combined ADM may serve as a safe and feasible alternative for selected HSCC patients.

Keywords: hypopharyngeal squamous cell carcinoma, anterolateral thigh free flap, acellular dermal matrix, reconstruction, dysphagia

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Authors: Maryam Hasanali, Syed Mohammad Mojtabaei, Iman Hajirasouliha, G. Charles Clifton, James B. P. Lim

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Cold-formed steel (CFS) elements are increasingly being used as main load-bearing components in the modern construction industry, including low- to mid-rise buildings. In typical multi-storey buildings, CFS structural members act as beam-column elements since they are exposed to combined axial compression and bending actions, both in moment-resisting frames and stud wall systems. Current design specifications, including the American Iron and Steel Institute (AISI S100) and the Australian/New Zealand Standard (AS/NZS 4600), neglect the beneficial effects of warping-restrained boundary conditions in the design of beam-column elements. Furthermore, while a non-linear relationship governs the interaction of axial compression and bending, the combined effect of these actions is taken into account through a simplified linear expression combining pure axial and flexural strengths. This paper aims to evaluate the reliability of the well-known Direct Strength Method (DSM) as well as design proposals found in the literature to provide a better understanding of the efficiency of the code-prescribed linear interaction equation in the strength predictions of CFS beam columns and the effects of warping-restrained boundary conditions on their behavior. To this end, the experimentally validated finite element (FE) models of CFS elements under compression and bending were developed in ABAQUS software, which accounts for both non-linear material properties and geometric imperfections. The validated models were then used for a comprehensive parametric study containing 270 FE models, covering a wide range of key design parameters, such as length (i.e., 0.5, 1.5, and 3 m), thickness (i.e., 1, 2, and 4 mm) and cross-sectional dimensions under ten different load eccentricity levels. The results of this parametric study demonstrated that using the DSM led to the most conservative strength predictions for beam-column members by up to 55%, depending on the element’s length and thickness. This can be sourced by the errors associated with (i) the absence of warping-restrained boundary condition effects, (ii) equations for the calculations of buckling loads, and (iii) the linear interaction equation. While the influence of warping restraint is generally less than 6%, the code suggested interaction equation led to an average error of 4% to 22%, based on the element lengths. This paper highlights the need to provide more reliable design solutions for CFS beam-column elements for practical design purposes.

Keywords: beam-columns, cold-formed steel, finite element model, interaction equation, warping-restrained boundary conditions

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Authors: Soroush Momeni

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

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

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Authors: Alessandra Turini Bolsoni-Silva, Sonia Regina Loureiro

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It is important to evaluate such variables simultaneously and differentiating types of behavior problems: internalizing, externalizing and with comorbidity of internalizing and externalizing. The objective was to compare, correlate and predict teacher educational practices (educational social skills and negative practices) and children's behaviors (social skills and behavior problems) of children with internalizing, externalizing and combined internalizing and externalizing problems, controlling variables of child (gender and education). A total of 262 children were eligible to compose the participants, considering preschool age from 3 to 5 years old (n = 109) and school age from 6 to 11 (n = 153) years old, and their teachers who were distributed, in designs case-control, non-clinical, with internalizing, externalizing problems and internalizing and externalizing comorbidity, using the Teacher's Report Form (TRF) as a criterion. The instruments were applied with the teachers, after consent from the parents/guardians: a) Teacher’s Report Form (TRF); b) Educational Social Skills Interview Guide for Teachers (RE-HSE-Pr); (c) Socially Skilled Response Questionnaire – Teachers (QRSH-Pr). The data were treated by univariate and multivariate analyses, proceeding with comparisons, correlations and predictions regarding the outcomes of children with and without behavioral problems, considering the types of problems. As main results stand out: (a) group comparison studies: in the Inter group there is emphasis on behavior problems in affection interactions, which does not happen in the other groups; as for positive practices, they discriminate against groups with externalizing and combined problems and not in internalizing ones, positive educational practices – hse are more frequent in the G-Exter and G-Inter+Exter groups; negative practices differed only in the G-Exter and G-Inter+Exter groups; b) correlation studies: it can be seen that the Inter+Exter group presents a greater number of correlations in the relationship between behavioral problems/complaints and negative practices and between children's social skills and positive practices/contexts; c) prediction studies: children's social skills predict internalizing, externalizing and combined problems; it is also verified that the negative practices are in the multivariate model for the externalizing and combined ones. This investigation collaborates in the identification of risk and protective factors for specific problems, helping in interventions for different problems.

Keywords: development, educational practices, social skills, behavior problems, teacher

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Authors: Georgi Y. Georgiev, Matthew Brouillet

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This research applies the power of agent-based modeling to a pivotal question at the intersection of biology, computer science, physics, and complex systems theory about the self-organization processes in open, complex, non-equilibrium thermodynamic systems. Central to this investigation is the principle of Maximum Entropy Production (MEP). This principle suggests that such systems evolve toward states that optimize entropy production, leading to the formation of structured environments. It is hypothesized that guided by the least action principle, open thermodynamic systems identify and follow the shortest paths to transmit energy and matter, resulting in maximal entropy production, internal structure formation, and a decrease in internal entropy. Concurrently, it is predicted that there will be an increase in system information as more information is required to describe the developing structure. To test this, an agent-based model is developed simulating an ant colony's formation of a path between a food source and its nest. Utilizing the Netlogo software for modeling and Python for data analysis and visualization, self-organization is quantified by calculating the decrease in system entropy based on the potential states and distribution of the ants within the simulated environment. External entropy production is also evaluated for information increase and efficiency improvements in the system's action. Simulations demonstrated that the system begins at maximal entropy, which decreases as the ants form paths over time. A range of system behaviors contingent upon the number of ants are observed. Notably, no path formation occurred with fewer than five ants, whereas clear paths were established by 200 ants, and saturation of path formation and entropy state was reached at populations exceeding 1000 ants. This analytical approach identified the inflection point marking the transition from disorder to order and computed the slope at this point. Combined with extrapolation to the final path entropy, these parameters yield important insights into the eventual entropy state of the system and the timeframe for its establishment, enabling the estimation of the self-organization rate. This study provides a novel perspective on the exploration of self-organization in thermodynamic systems, establishing a correlation between internal entropy decrease rate and external entropy production rate. Moreover, it presents a flexible framework for assessing the impact of external factors like changes in world size, path obstacles, and friction. Overall, this research offers a robust, replicable model for studying self-organization processes in any open thermodynamic system. As such, it provides a foundation for further in-depth exploration of the complex behaviors of these systems and contributes to the development of more efficient self-organizing systems across various scientific fields.

Keywords: complexity, self-organization, agent based modelling, efficiency

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Authors: Lan Yang, Kathryn Cormican, Ming Yu

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ISO/IEC/IEEE 15288: 2015, Systems and Software Engineering - System Life Cycle Processes is an international standard that provides generic top-level process descriptions to support systems engineering (SE). However, the processes defined in the standard needs improvement to lift integrity and consistency. The goal of this research is to explore the way by building an ontology model for the SE standard to manage the knowledge of SE. The ontology model gives a whole picture of the SE knowledge domain by building connections between SE concepts. Moreover, it creates a hierarchical classification of the concepts to fulfil different requirements of displaying and analysing SE knowledge.

Keywords: knowledge management, model-based systems engineering, ontology modelling, systems engineering ontology

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Authors: Sara Jelodarian

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Organic agriculture is a kind of living and dynamic agriculture that was introduced in the early 20^th century. The fundamental basis for organic agriculture is in harmony with nature. This version of farming emphasizes removing growth hormones, chemical fertilizers, toxins, radiation, genetic manipulation and instead, integration of modern scientific techniques (such as biologic and microbial control) that leads to the production of healthy food and the preservation of the environment and use of agricultural products such as forage and manure. Supports from governments for the markets producing organic products and taking advantage of the experiences from other successful societies in this field can help progress the positive and effective aspects of this technology, especially in developing countries. This research proves that till 2030, 25% of the global agricultural lands would be covered by organic farming. Consequently Iran, due to its rich genetic resources and various climates, can be a pioneer in promoting organic products. In addition, for sustainable farming, blend of organic and other innovative systems is needed. Important limitations exist to accept these systems, also a diversity of policy instruments will be required to comfort their development and implementation. The paper was conducted to results of compilation of reports, issues, books, articles related to the subject with library studies and research. Likewise we combined experimental and survey to get data.

Keywords: develop, production markets, progress, strategic role, technology

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Authors: A. Falsafi, M. Dadkhah, S. Shahidi

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The destruction and defeat of drill pipes and drill rigs in oil wells often combined with a combination of shear modulus II and III. In such a situation, the strength and load bearing capacity of the drill are evaluated based on the principles of fracture mechanics and crack growth criteria. In this paper, using the three-dimensional stress equations around the Turkish frontier, the relations of the tense-tense criterion (MTS) are extracted for the loading of the combined II and III modulus. It is shown that in crisp deflection under loading of combination II and III, the level of fracture is characterized by two different angles: the longitudinal angle of deflection θ and the angle of the deflection of the alpha. Based on the relationships obtained from the MTS criterion, the failure criteria, the longitudinal angle of the theta failure and the lateral angle of the failure of the alpha are presented. Also, the role of Poisson's coefficient on these parameters is investigated in these graphs.

Keywords: most tangential tension criterion, longitudinal angle of failure, side angle of fracture, drills crack

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Authors: Nathen A. Spitz, Dennis Martin Kivlighan III, Arwa Aburizik

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Background and Purpose: Presently, there is a paucity of naturalistic studies that directly compare the effectiveness of psychotherapy versus concurrent psychotherapy and psychiatric care for the treatment of depression and anxiety in cancer patients. Informed by previous clinical trials examining the efficacy of concurrent approaches, this study sought to test the hypothesis that a combined approach would result in the greatest reduction of depression and anxiety symptoms. Methods: Data for this study consisted of 433 adult cancer patients, with 252 receiving only psychotherapy and 181 receiving concurrent psychotherapy and psychiatric care at the University of Iowa Hospitals and Clinics. Longitudinal PHQ9 and GAD7 data were analyzed between both groups using latent growth curve analyses. Results: After controlling for treatment length and provider effects, results indicated that concurrent care was more effective than psychotherapy alone for depressive symptoms (γ₁₂ = -0.12, p = .037). Specifically, the simple slope for concurrent care was -0.25 (p = .022), and the simple slope for psychotherapy alone was -0.13 (p = .006), suggesting that patients receiving concurrent care experienced a greater reduction in depressive symptoms compared to patients receiving psychotherapy alone. In contrast, there were no significant differences between psychotherapy alone and concurrent psychotherapy and psychiatric care in the reduction of anxious symptoms. Conclusions: Overall, as both psychotherapy and psychiatric care may address unique aspects of mental health conditions, in addition to potentially providing synergetic support to each other, a combinatorial approach to mental healthcare for cancer patients may improve outcomes.

Keywords: psychiatry, psychology, psycho-oncology, combined care, psychotherapy, behavioral psychology

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Authors: G. González, J. Ramírez, A. Rubiano

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This article describes different patented systems for safe use in vehicles based on GPS technology, speed sensors, gyroscopes, maps, communication systems, and monitors, that inform the driver about traffic jam, obstruction in the road, speed limits, among others. Once the information is analyzed and contrasted to final propose new technical needs to be solved.

Keywords: GPS, information technology, telecommunications, communication networks, gyroscope, environmental pollution

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Authors: Dong Il Shim, Geehong Choi, Donghwi Lee, Namkyu Lee, Hyung Hee Cho

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Effective cooling technology is required to secure thermal stability in extreme heat generated systems such as integrated electronic devices and power generated systems. Pool boiling heat transfer is one of the powerful cooling mechanisms using phase change phenomena. Critical heat flux (CHF) and heat transfer coefficient (HTC) are main factors to evaluate the performance of boiling heat transfer. CHF is the limitation of boiling heat transfer before film boiling which occurs thermal failure. Surface wettability is an important surface characteristic of boiling heat transfer. A hydrophilic surface has higher CHF through effective working fluid supply to local hot spots. A hydrophobic surface promotes the onset of nucleate boiling (ONB) to enhance HTC. In this study, superbiphilic surfaces, which is combined with superhydrophillic and superhydrophobic, are applied on boiling experiments to maximize boiling performance. We conducted pool boiling heat transfer using DI water at a saturated temperature and recorded bubble dynamics using a high-speed camera with 2000 fps. As a result, superbiphilic patterned surfaces promote ONB and enhance both CHF and HTC. This study demonstrates the enhanced boiling performance using superbiphilic surfaces by effective nucleation and separation of liquid/vapor pathway. We expect that further enhancement of heat transfer could be achieved in future work using optimized patterned surfaces.

Keywords: boiling heat transfer, wettability, critical heat flux, heat transfer coefficient

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Authors: C. Trapp, A. Vijay, M. Khorasani

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Decentralised micro-grids with sector coupling can combat the spatial and temporal intermittence of renewable energy by combining power, transportation and infrastructure sectors. Intelligent energy conversion concepts such as electrolysers, hydrogen engines and fuel cells combined with energy storage using intelligent batteries and hydrogen storage form the back-bone of such a system. This paper describes a micro-grid based on Photo-Voltaic cells, battery storage, innovative modular and scalable Anion Exchange Membrane (AEM) electrolyzer with an efficiency of up to 73%, high-pressure hydrogen storage as well as cutting-edge combustion-engine based Combined Heat and Power (CHP) plant with more than 85% efficiency at the university campus to address the challenges of decarbonization whilst eliminating the necessity for expensive high-voltage infrastructure.

Keywords: sector coupling, micro-grids, energy self-sufficiency, decarbonization, AEM electrolysis, hydrogen CHP

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Authors: Adedayo Adeleke, Dineo Pule

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The ongoing load-shedding in most parts of South Africa, combined with climate change causing severe drought conditions in Cape Town, has left electricity consumers seeking alternative sources of power and water. Solar energy, which is abundant in most parts of South Africa and is regarded as a clean and renewable source of energy, allows for the generation of electricity via solar photovoltaic systems. Rainwater harvesting is the collection and storage of rainwater from building rooftops, allowing people without access to water to collect it. The lack of dependable energy and water source must be addressed by shifting to solar energy via solar photovoltaic systems and rainwater harvesting. Before this can be done, the potential of building rooftops must be assessed to determine whether solar energy and rainwater harvesting will be able to meet or significantly contribute to Atlantis industrial areas' electricity and water demands. This research project presents methods and approaches for automatically extracting building rooftops in Atlantis industrial areas and evaluating their potential for solar photovoltaics and rainwater harvesting systems using Light Detection and Ranging (LiDAR) data and aerial imagery. The four objectives were to: (1) identify an optimal method of extracting building rooftops from aerial imagery and LiDAR data; (2) identify a suitable solar radiation model that can provide a global solar radiation estimate of the study area; (3) estimate solar photovoltaic potential overbuilding rooftop; and (4) estimate the amount of rainwater that can be harvested from the building rooftop in the study area. Mapflow, a plugin found in Quantum Geographic Information System(GIS) was used to automatically extract building rooftops using aerial imagery. The mean annual rainfall in Cape Town was obtained from a 29-year rainfall period (1991- 2020) and used to calculate the amount of rainwater that can be harvested from building rooftops. The potential for rainwater harvesting and solar photovoltaic systems was assessed, and it can be concluded that there is potential for these systems but only to supplement the existing resource supply and offer relief in times of drought and load-shedding.

Keywords: roof potential, rainwater harvesting, urban plan, roof extraction

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Authors: Lalit Tejwani, Reetika Sharma, Arun Singhvi, Himanshu Shekhar

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Purpose: To assess the efficacy of collagen matrix implant (Ologen) in phacotrabeculectomy augmented with mitomycin C (MMC). Methods: A biodegradable collagen matrix (Ologen) was placed in the subconjunctival and subscleral space in twenty-two eyes of 22 patients with glaucoma and cataract who underwent combined phacoemulsification and trabeculectomy augmented with MMC. All of them were examined preoperatively and on the first postoperative day. They were followed for twelve months after surgery. Any intervention needed in follow-up period was noted. Any complication was recorded. The primary outcome measure was postoperative intraocular pressure at one year follow-up. Any additional postoperative treatments needed and adverse events were noted. Results: The mean age of patients included in the study was 57.77 ± 9.68 years (range=36 to 70 years). All the patients were followed for at least one year. Three patients had history of failed trabeculectomy. Fifteen patients had chronic angle closure glaucoma with cataract, five had primary open angle glaucoma with cataract, one had uveitic glaucoma with cataract, and one had juvenile open angle glaucoma with cataract. Mean preoperative IOP was 32.63 ± 8.29 mm Hg, eighteen patients were on oral antiglaucoma medicines. The mean postoperative IOP was 10.09 ± 2.65 mm Hg at three months, 10.36 ± 2.19 mm Hg at six months and 11.36 ± 2.72 mm Hg at one year follow up. No adverse effect related to Ologen was seen. Anterior chamber reformation was done in five patients, and three needed needling of bleb. Four patients needed additional antiglaucoma medications in the follow-up period. Conclusions: Combined phacotrabeculectomy with MMC with Ologen implantation appears to be a safe and effective option in glaucoma patients needing trabeculectomy with significant cataract. Comparative studies with longer duration of follow-up in larger number of patients are needed.

Keywords: combined surgery, ologen, phacotrabeculectomy, success

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Authors: Gauthier Lefevre, Holger Kohlmann, Sebastien Saitzek, Rachel Desfeux, Adlane Sayede

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Hydrogen is a promising energy carrier, compatible with the sustainable energy concept. In this context, solid-state hydrogen-storage is the key challenge in developing hydrogen economy. The capability of absorption of large quantities of hydrogen makes intermetallic systems of particular interest. In this study, efforts have been devoted to the theoretical investigation of binary systems with constraints consideration. On the one hand, besides considering hydrogen-storage, a reinvestigation of crystal structures of the palladium-arsenic system shows, with experimental validations, that binary systems could still currently present new or unknown relevant structures. On the other hand, various binary Mg-based systems were theoretically scrutinized in order to find new interesting alloys for hydrogen storage. Taking the effect of pressure into account reveals a wide range of alternative structures, changing radically the stable compounds of studied binary systems. Similar constraints, induced by Pulsed Laser Deposition, have been applied to binary systems, and results are presented.

Keywords: binary systems, evolutionary algorithm, first principles study, pulsed laser deposition

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Authors: Ting-Ting Wen, H. C. Lin

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This paper reports a study for the light outcoupling efficiency of the PLED device. In use of a designed substrate combined with nano-line patterns in PLED device, the light outcoupling efficiency can be significantly enhanced. The designed substrate was made by UV imprinting technology, such as triangular microlens arrays on the front and periodic corrugated patterns on the back surface. The nano-line patterns in PLED device was fabricated by advanced microstamping and ink-jet printing techniques. For high angles of observation with respect to the substrate surface normal, the light out intensity of the developed PLED device is increased from 0.05 (a.u.) up to 0.69 (a.u.) at the view angle 85 degree. The designed integration leads to 64% increase of the light out intensity compared with the conventional PLED device.

Keywords: triangular microlens, corrugation patterns, nano-line patterns, PLED device, UV imprinting technology, microstamping

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Authors: Dong Sang Yoo

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We consider nonlinear uncertain systems such that a priori information of the uncertainties is not available. For such systems, we assume that the upper bound of the uncertainties is represented as a Fredholm integral equation of the first kind and we propose an adaptation law that is capable of estimating the upper bound and design a continuous robust control which renders nonlinear uncertain systems ultimately bounded.

Keywords: adaptive control, estimation, Fredholm integral, uncertain system

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Authors: Cornelius Femi Popoola

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This study investigated logistics information systems in the distribution of flour in Nigeria. A case study design was used and 50 staff of Honeywell Flour Mill was sampled for the study. Data generated through a questionnaire were analysed using correlation and regression analysis. The findings of the study revealed that logistic information systems such as e-commerce, interactive telephone systems and electronic data interchange positively correlated with the distribution of flour in Honeywell Flour Mill. Finding also deduced that e-commerce, interactive telephone systems and electronic data interchange jointly and positively contribute to the distribution of flour in Honeywell Flour Mill in Nigeria (R = .935; Adj. R2 = .642; F (3,47) = 14.739; p < .05). The study therefore recommended that Honeywell Flour Mill should upgrade their logistic information systems to computer-to-computer communication of business transactions and documents, as well adopt new technology such as, tracking-and-tracing systems (barcode scanning for packages and palettes), tracking vehicles with Global Positioning System (GPS), measuring vehicle performance with ‘black boxes’ (containing logistic data), and Automatic Equipment Identification (AEI) into their systems.

Keywords: e-commerce, electronic data interchange, flour distribution, information system, interactive telephone systems

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Authors: Junze Li, M. Li

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Laser diodes fabricated from the III-nitride material system are emerging solutions for the next generation telecommunication systems and optical clocks based on Ca at 397nm, Rb at 420.2nm and Yb at 398.9nm combined 556 nm. Most of the applications require single longitudinal optical mode lasers, with very narrow linewidth and compact size, such as communication systems and laser cooling. In this case, the GaN based distributed feedback (DFB) laser diode is one of the most effective candidates with gratings are known to operate with narrow spectra as well as high power and efficiency. Given the wavelength range, the period of the first-order diffraction grating is under 100 nm, and the realization of such gratings is technically difficult due to the narrow line width and the high quality nitride overgrowth based on the Bragg grating. Some groups have reported GaN DFB lasers with high order distributed feedback surface gratings, which avoids the overgrowth. However, generally the strength of coupling is lower than that with Bragg grating embedded into the waveguide within the GaN laser structure by two-step-epitaxy. Therefore, the overgrowth on the grating technology need to be studied and optimized. Here we propose to fabricate the fine step shape structure of first-order grating by the nanoimprint combined inductively coupled plasma (ICP) dry etching, then carry out overgrowth high quality AlGaN film by metalorganic chemical vapor deposition (MOCVD). Then a series of gratings with different period, depths and duty ratios are designed and fabricated to study the influence of grating structure to the nano-heteroepitaxy. Moreover, we observe the nucleation and growth process by step-by-step growth to study the growth mode for nitride overgrowth on grating, under the condition that the grating period is larger than the mental migration length on the surface. The AFM images demonstrate that a smooth surface of AlGaN film is achieved with an average roughness of 0.20 nm over 3 × 3 μm2. The full width at half maximums (FWHMs) of the (002) reflections in the XRD rocking curves are 278 arcsec for the AlGaN film, and the component of the Al within the film is 8% according to the XRD mapping measurement, which is in accordance with design values. By observing the samples with growth time changing from 200s, 400s to 600s, the growth model is summarized as the follow steps: initially, the nucleation is evenly distributed on the grating structure, as the migration length of Al atoms is low; then, AlGaN growth alone with the grating top surface; finally, the AlGaN film formed by lateral growth. This work contributed to carrying out GaN DFB laser by fabricating grating and overgrowth on the nano-grating patterned substrate by wafer scale, moreover, growth dynamics had been analyzed as well.

Keywords: DFB laser, MOCVD, nanoepitaxy, III-niitride

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Authors: Mohamed Hassan Abdullahi

Abstract:

Decomposition is used as a synthesis tool in several physical systems. It can also be used for tearing and restructuring, which is large-scale system analysis. On the other hand, the commutativity of series-connected systems has fascinated the interest of researchers, and its advantages have been emphasized in the literature. The presentation looks into the necessary conditions for decomposing any third-order discrete-time linear time-varying system into a commutative pair of first- and second-order systems. Additional requirements are derived in the case of nonzero initial conditions. MATLAB simulations are used to verify the findings. The work is unique and is being published for the first time. It is critical from the standpoints of synthesis and/or design. Because many design techniques in engineering systems rely on tearing and reconstruction, this is the process of putting together simple components to create a finished product. Furthermore, it is demonstrated that regarding sensitivity to initial conditions, some combinations may be better than others. The results of this work can be extended for the decomposition of fourth-order discrete-time linear time-varying systems into lower-order commutative pairs, as two second-order commutative subsystems or one first-order and one third-order commutative subsystems.

Keywords: commutativity, decomposition, discrete time-varying systems, systems

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Authors: Abhishek Dave, Manisha Singh

Abstract:

Purpose: The study aims to evaluate the outcomes of combined Penetrating keratoplasty (PKP) and Vitreo-Retinal (VR) surgery in patients having endophthalmitis with poor corneal clarity. Methods: PKP with VR Surgery was performed in 43 eyes. This is a retrospective analysis of their preoperative, intraoperative and microbiological characteristics and anatomical and functional outcomes. Results: Corneal opacification was due to corneal ulcer in 30 (69.7%), graft infection in 8 (18.6%), bullous keratopathy in 4 and corneal scar in 1 eye. Postoperative visual acuity improved in 20 (46.5%), not changed in 14 (32.5%) and deteriorated in 9 eyes (20.9%). Poor anatomic success was seen in 15 (34.88%) eyes (9-phthisis bulbi, 6-eviscerated). Graft remained clear in 24 eyes (1 year). Microbiology revealed bacteria in 26, fungus in 14 and no growth in 3 eyes. Six out of 11 patients having poor vision in the fellow eye, too, achieved functional success. Conclusion: PKP with VR surgery is a complex but globe-salvaging procedure for poor prognosis eyes, which otherwise would need evisceration.

Keywords: penetrating keratoplasty, VR surgery, endophthalmitis, corneal ulcer

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Authors: Stephanie Chen, Mitja Echim, Christof Büskens

Abstract:

To describe and propagate the behavior of a system mathematical models are formulated. Parameter identification is used to adapt the coefficients of the underlying laws of science. For complex systems this approach can be incomplete and hence imprecise and moreover too slow to be computed efficiently. Therefore, these models might be not applicable for the numerical optimization of real systems, since these techniques require numerous evaluations of the models. Moreover not all quantities necessary for the identification might be available and hence the system must be adapted manually. Therefore, an approach is described that generates models that overcome the before mentioned limitations by not focusing on physical laws, but on measured (sensor) data of real systems. The approach is more general since it generates models for every system detached from the scientific background. Additionally, this approach can be used in a more general sense, since it is able to automatically identify correlations in the data. The method can be classified as a multivariate data regression analysis. In contrast to many other data regression methods this variant is also able to identify correlations of products of variables and not only of single variables. This enables a far more precise and better representation of causal correlations. The basis and the explanation of this method come from an analytical background: the series expansion. Another advantage of this technique is the possibility of real-time adaptation of the generated models during operation. Herewith system changes due to aging, wear or perturbations from the environment can be taken into account, which is indispensable for realistic scenarios. Since these data driven models can be evaluated very efficiently and with high precision, they can be used in mathematical optimization algorithms that minimize a cost function, e.g. time, energy consumption, operational costs or a mixture of them, subject to additional constraints. The proposed method has successfully been tested in several complex applications and with strong industrial requirements. The generated models were able to simulate the given systems with an error in precision less than one percent. Moreover the automatic identification of the correlations was able to discover so far unknown relationships. To summarize the above mentioned approach is able to efficiently compute high precise and real-time-adaptive data-based models in different fields of industry. Combined with an effective mathematical optimization algorithm like WORHP (We Optimize Really Huge Problems) several complex systems can now be represented by a high precision model to be optimized within the user wishes. The proposed methods will be illustrated with different examples.

Keywords: adaptive modeling, automatic identification of correlations, data based modeling, optimization

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Authors: Man Young Kim

Abstract:

To reduce the NOx emission in a Diesel vehicle, such various after treatment systems as SCR, LNC, and LNT are frequently visited as promising systems. Among others, urea-based SCR systems are known to be stable, effective technologies that can reduce NOx emissions most efficiently from diesel exhaust systems. In this study, therefore, effect of urea injector installation angle on the evaporation and mixing characteristics is investigated to find optimum operation conditions. It can be found that the injection angle significantly affects the thermal behavior of the urea-water solution in the diesel exhaust gases.

Keywords: selective catalytic reduction (SCR), evaporation, thermolysis, urea-water solution (UWS), injector installation angle

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Authors: Rita Bagheri, Javed Ahmed, Humayra Bashir, M. Irfan Qureshi

Abstract:

Agriculture lands suffer from a combination of stresses such as salinity and metal contamination including cadmium at the same time. Under such condition of multiple stresses, plant may exhibit unique responses different from the stress occurring individually. Thus, it would be interesting to investigate that how plant respond to combined stress at level of antioxidants and proteome expression, and identifying the proteins which are involved in imparting stress tolerance. With an approach of comparative proteomics and antioxidant analysis, present study investigates the response of Spinacia oleracea to salt (NaCl), cadmium (Cd), and their combination (NaCl+Cd) stress. Two-dimensional gel electrophoresis was used for resolving leaf proteome, and proteins of interest were identified using PDQuest software. A number of proteins expressed differentially, those indicated towards their roles in imparting stress tolerance, were digested by trypsin and analyzed on mass spectrometer for peptide mass fingerprinting (PMF). Data signals were then matched with protein databases using MASCOT. Results show that NaCl, Cd and both together (NaCl+Cd) induce oxidative stress which was highest in combined stress of Cd+NaCl. Correspondingly, the activities of enzymatic antioxidants viz., SOD, APX, GR and CAT, and non-enzymatic antioxidants had highest changes under combined stress compares to single stress over their respective controls. Among the identified proteins, several interesting proteins were identified that may be have role in Spinacia oleracia tolerance in individual and combinatorial stress of salt and cadmium. The functional classification of identified proteins indicates the importance and necessity of keeping higher ratio of defence and disease responsive proteins.

Keywords: Spinacia oleracea, Cd, salinity, proteomics, antioxidants, combinatorial stress

Procedia PDF Downloads 360