Search results for: solar cycle

Authors: Svetlana Pushkar, Oleg Verbitsky

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The goal of the present study is to evaluate environmental damage from four wall technologies under the following conditions: four climate zones in Israel, two building (conventional vs. low-energy) types, and two types of fuel source [natural gas vs. photovoltaic (PV)]. The hierarchical ReCiPe method with a two-stage nested (hierarchical) ANOVA test is applied. It was revealed that in a hot climate in Israel in a conventional building fueled by natural gas, OE is dominant (90 %) over the P&C stage (10 %); in a mild climate in Israel in a low-energy building with PV, the P&C stage is dominant (85 %) over the OE stage (15 %). It is concluded that if PV is used in the building sector in Israel, (i) the P&C stage becomes a significant factor that influences the environment, (ii) autoclaved aerated block is the best external wall technology, and (iii) a two-stage nested mixed ANOVA can be used to evaluate environmental damage via ReCiPe when wall technologies are compared.

Keywords: life cycle assessment (LCA), photovoltaic, ReCiPe method, residential buildings

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Authors: Yasunori Kobori, Futoshi Fukaya, Takuya Arafune, Nobukazu Tsukiji, Nobukazu Takai, Haruo Kobayashi

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This paper proposes an EMI spread spectrum technique to enable to set notch frequencies using pulse coding method for DC-DC switching converters of communication equipment. The notches in the spectrum of the switching pulses appear at the frequencies obtained from empirically derived equations with the proposed spread spectrum technique using the pulse coding methods, the PWM (Pulse Width Modulation) coding or the PCM (Pulse Cycle Modulation) coding. This technique would be useful for the switching converters in the communication equipment which receives standard radio waves, without being affected by noise from the switching converters. In our proposed technique, the notch frequencies in the spectrum depend on the pulse coding method. We have investigated this technique to apply to the switching converters and found that there is good relationship agreement between the notch frequencies and the empirical equations. The notch frequencies with the PWM coding is equal to the equation F=k/(WL-WS). With the PCM coding, that is equal to the equation F=k/(TL-TS).

Keywords: notch frequency, pulse coding, spread spectrum, switching converter

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Authors: Abegunde Linda, Adedeji Oluwatola

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It has become increasingly evident that large developments influence the climate within the immediate region and there are concerns that rising temperatures over developed areas could have negative impact and increase living discomfort within city boundaries. Temperature trends in Ibadan city have received minor attention, yet the area has experienced heavy urban expansion between 1972 and 2014. This research aims at examining the impact of landuse change on temperature knowing that the built environment absorbs and stores solar energy, the temperature in cities can be several degrees higher than in adjacent rural areas. This is known as the urban heat island (UHI) effect. The Landsat imagery were used to examine the landuse change for a time period of 42years (1972-2014) and Land surface temperature (LST) was obtained by converting the thermal band to a surface temperature map and zonal statistic analyses was further used to examine the relationship between landuse and temperature emission. The results showed that the settlement area increased by 200km2 while the area covered by vegetation also reduced to about 42.6% during the study period. The spatial and temporal trends of temperature are related to the gradual change in urban landcover and the settlement area has the highest emission of land surface temperature. This research provides useful insight into the temporal behavior of the Ibadan city.

Keywords: landuse, LST, remote sensing, UHI

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Authors: Orose Rugchati, Sarawut Wattanawongpitak

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This research studied the analysis of the thermal conductivity and heat transfer in porcine meat due to the electric current flowing between the electrode plates in parallel. Hot-boned pork sample was prepared in 2*1*1 cubic centimeter. The finite element method with ANSYS workbench program was applied to simulate this heat transfer problem. In the thermal simulation, the input thermoelectric energy was calculated from measured current that flowing through the pork and the input voltage from the dc voltage source. The comparison of heat transfer in pork according to two voltage sources: DC voltage 30 volts and dc pulsed voltage 60 volts (pulse width 50 milliseconds and 50 % duty cycle) were demonstrated. From the result, it shown that the thermal conductivity trends to be steady at temperature 40C and 60C around 1.39 W/mC and 2.65 W/mC for dc voltage source 30 volts and dc pulsed voltage 60 volts, respectively. For temperature increased to 50C at 5 minutes, the appearance color of porcine meat at the exposer point has become to fade. This technique could be used for predicting of thermal conductivity caused by some meat’s characteristics.

Keywords: thermal conductivity, porcine meat, electricity, finite element method

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Authors: Ibrahim Abubakar Mikugi

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Nigerian graduates could only be self-employed and marketable if they acquire relevant skills and knowledge for successful establishment in various occupation and gainful employment. Research has shown that entrepreneurship education will be successful through developing individual entrepreneurial attitudes, raising awareness of career options by integrating and inculcating a positive attitude in the mind of students through skill acquisition. This paper examined the student- led entrepreneurship education through skill acquisition with specific emphasis on analysis of David Kolb experiential learning cycle. This Model allows individual to review their experience through reflection and converting ideas into action by doing. The methodology used was theoretical approach through journal, internet and Textbooks. Challenges to entrepreneurship education through skill acquisition were outlined. The paper concludes that entrepreneurship education is recognised by both policy makers and academics; entrepreneurship is more than mere encouraging business start-ups. Recommendations were given which include the need for authorities to have a clear vision towards entrepreneurship education and skill acquisition. Authorities should also emphasise a periodic and appropriate evaluation of entrepreneurship and to also integrate into schools academic curriculum to encourage practical learning by doing.

Keywords: entrepreneurship, entrepreneurship education, active learning, Cefe methodology

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Authors: Cihan Cilbircioğlu

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Allium sativum L.(garlic) and Allium. cepa L. (onion) are the most common species of the Allium spp. and are produced at the very high rate all over the world. The yield loss caused by pests is the most important problem in the production of these crops. In the absence of control measures, yield loss would be around 35% on average. The yield loss sometimes depending on the pest species and population density can reach about 100%. Mites and nematodes are the most important pests of them. These pests that cause damage to A. sativum and A. cepa shows a wide range of taxonomic categories. The number of common pest mite and nematode species that cause damage to either A. sativum and A. cepa are over 20 species. In this study, detailed information on morphology, life cycle, management, and symptoms of the economically most important harmful important mite (acari) and nematode species of onion and garlic has been provided through careful survey of corresponding researches in Turkey and given information about new practices and approaches on their controls.

Keywords: onion, garlic, pest, acari, nematoda control methods, Turkey

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Authors: Patrick O. Bobbie, Prince S. Attrams

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In recent times, the rapid change in new technologies has spurred up the way and manner records are handled in educational institutions. Also, there is a need for reliable access and ease-of use to these records, resulting in increased productivity in organizations. In academic institutions, such benefits help in quality assessments, institutional performance, and assessments of teaching and evaluation methods. Students in educational institutions benefit the most when advanced technologies are deployed in accessing records. This research paper discusses the use of biometric technologies coupled with smartcard technologies to provide a unique way of identifying students and matching their data to financial records to grant them access to restricted areas such as examination halls. The system developed in this paper, has an identity verification component as part of its main functionalities. A systematic software development cycle of analysis, design, coding, testing and support was used. The system provides a secured way of verifying student’s identity and real time verification of financial records. An advanced prototype version of the system has been developed for testing purposes.

Keywords: biometrics, smartcards, identity-verification, fingerprints

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Authors: M. H. Shwehdi, S. Raja Mohammad

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Recently energy savings have become more pronounced as a result of the world financial crises as well the unstable oil prices. Certainly all entities needs to adapt Energy Conservation and Management Strategies due to high monthly consumption of their spread locations and advancements of its telecom systems. These system improvements necessitate the establishment of more exchange centers as well provide energy savings. This paper investigates the impact of HVAC System Characteristics, Operational Strategies, the impact of Envelope Thermal Characteristics, and energy conservation measures. These are classified under three types of measures i.e. Zero-Investment; Low-Investment and High-Investment Energy Conservation Measures. The study shows that the Energy Conservation Measures (ECMs) pertaining to the HVAC system characteristics and operation represent the highest potential for energy reduction, attention should be given to window thermal and solar radiation characteristics when large window areas are used. The type of glazing system needs to be carefully considered in the early design phase of future buildings. Paper will present the thermal optimization of different size centers in the two hot-dry and hot-humid Saudi Arabian city of Al Khobar, East province.

Keywords: energy conservation, optimization, thermal design, intermittent operation, exchange centers, hot-humid climate, Saudi Arabia

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Authors: Sanjeev Kumar, S. K. Nath

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Proper selection of welding parameters for getting excellent weld is a challenge. HAZ simulation helps in identifying suitable welding parameters like heating rate, cooling rate, peak temperature, and energy input. In this study, the influence of weld thermal cycle of heat affected zone (HAZ) is simulated for Submerged Arc Welding (SAW) using Gleeble ® 3800 thermomechanical simulator. A (Micro-alloyed) MA steel plate of thickness 18 mm having yield strength 450MPa is used for making test specimens. Determination of the mechanical properties of weld simulated specimens including Charpy V-notch toughness and hardness is performed. Peak temperatures of 1300°C, 1150°C, 1000°C, 900°C, 800°C, heat energy input of 22KJ/cm and preheat temperatures of 30°C have been used with Rykalin-3D simulation model. It is found that the impact toughness (75J) is the best for the simulated HAZ specimen at the peak temperature 900ºC. For parent steel, impact toughness value is 26.8J at -50°C in transverse direction.

Keywords: HAZ simulation, mechanical properties, peak temperature, ship hull steel, weldability

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Authors: Auwal Mustapha Imam

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The aim of the energy management system is to monitor and control utilization, access, optimize and manage energy availability. This can be realized through real-time analyses and energy sources and loads data control in a predictive way. Smart-home monitoring and control provide convenience and cost savings by controlling appliances, lights, thermostats and other loads. There may be different categories of loads in the various homes, and the homeowner may wish to control access to solar-generated energy to protect the storage from draining completely. Controlling the power system operation by managing the converter output power and controlling how it feeds the appliances will satisfy the residential load demand. The Internet of Things (IoT) provides an attractive technological platform to connect the two and make home automation and domestic energy utilization easier and more attractive. This paper presents the use of IoT-based control topology to monitor and control power distribution and consumption by DC loads connected to single-input multiple outputs (SIMO) DC-DC converter, thereby reducing leakages, enhancing performance and reducing human efforts. A SIMO converter was first developed and integrated with the IoT/Raspberry Pi control topology, which enables the user to monitor and control power scheduling and load forecasting via an Android app.

Keywords: flyback, converter, DC-DC, photovoltaic, SIMO

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Authors: Eden G. Mariquit, Winarto Kurniawan, Masahiro Miyauchi, Hirofumi Hinode

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This research studied the effect of adding surfactant to the titanium dioxide (TiO2) sol-gel solution that was used to immobilize TiO2 on glass substrates by dip coating technique using TiO2 sol-gel solution mixed with different types of surfactants. After dipping into the TiO2 sol, the films were calcined and produced pure anatase crystal phase. The thickness of the thin film was varied by repeating the dip and calcine cycle. The prepared films were characterized using FE-SEM, TG-DTA, and XRD, and its photocatalytic performances were tested on degradation of an organic dye, methylene blue. Aside from its phocatalytic performance, the photo-induced hydrophilicity of thin TiO2 films surface was also studied. Characterization results showed that the addition of surfactant gave rise to characteristic patterns on the surface of the TiO2 thin film which also affects the photocatalytic activity. The addition of CTAB to the TiO2 dipping solution had a negative effect because the calcination temperature was not high enough to burn all the surfactants off. As for the surface wettability, the addition of surfactant also affected the induced surface hydrophilicity of the TiO2 films when irradiated under UV light.

Keywords: photocatalysis, surface hydrophilicity, TiO2 thin films, surfactant

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Authors: H. Özkan Gülsoy, Antonyraj Arockiasamy

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The application of powder injection molding technology for the fabrication of metallic and non-metallic components is of growing interest as the process considerably saves time and cost. Utilizing this fabrication method, full dense components are being prepared in various sizes. In this work, our effort is focused to study the densification behavior of the parts made using different size 316L stainless steel powders. The metal powders were admixed with an adequate amount of polymeric compounds and molded as standard tensile bars. Solvent and thermal debinding was carried out followed by sintering in ultra pure hydrogen atmosphere based on the differential scanning calorimetry (DSC) cycle. Mechanical property evaluation and microstructural characterization of the sintered specimens was performed using universal Instron tensile testing machine, Vicker’s microhardness tester, optical (OM) and scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction were used. The results are compared and analyzed to predict the strength and weakness of the test conditions.

Keywords: powder injection molding, sintering, particle size, stainless steels

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Authors: Rui Sang, Fei Deng, Alexander Engel, Ewa M. Goldys, Wei Deng

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In this study, we brought together X-ray induced photodynamic therapy (X-PDT) and chemo-drug (5-FU) for the treatment on colorectal cancer cells. This was achieved by developing a lipid-polymer hybrid nanoparticle delivery system (FA-LPNPs-VP-5-FU). It was prepared by incorporating a photosensitizer (verteporfin), chemotherapy drug (5-FU), and a targeting moiety (folic acid) into one platform. The average size of these nanoparticles was around 100 nm with low polydispersity. When exposed to clinical doses of 4 Gy X-ray radiation, FA-LPNPs-VP-5-FU generated sufficient amounts of reactive oxygen species, triggering the apoptosis and necrosis pathway of cancer cells. Our combined X-PDT and chemo-drug strategy was effective in inhibiting cancer cells’ growth and proliferation. Cell cycle analyses revealed that our treatment induced G2/M and S phase arrest in HCT116 cells. Our results indicate that this combined treatment provides better antitumour effect in colorectal cancer cells than each of these modalities alone. This may offer a novel approach for effective colorectal cancer treatment with reduced off-target effect and drug toxicity.

Keywords: pdt, targeted lipid-polymer nanoparticles, verteporfin, colorectal cancer

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Authors: Kaoutar Ben Azzou, Hanaa Talei

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Human resources is an important department in each organization as it manages the life cycle of employees from recruitment training to retirement or termination of contracts. The recruitment process starts with a job opening, followed by a selection of the best-fit candidates from all applicants. Matching the best profile for a job position requires a manual way of looking at many CVs, which requires hours of work that can sometimes lead to choosing not the best profile. The work presented in this paper aims at reducing the workload of HR personnel by automating the preliminary stages of the candidate screening process, thereby fostering a more streamlined recruitment workflow. This tool introduces an automated system designed to help with the recruitment process by scanning candidates' CVs, extracting pertinent features, and employing machine learning algorithms to decide the most fitting job profile for each candidate. Our work employs natural language processing (NLP) techniques to identify and extract key features from unstructured text extracted from a CV, such as education, work experience, and skills. Subsequently, the system utilizes these features to match candidates with job profiles, leveraging the power of classification algorithms.

Keywords: automated recruitment, candidate screening, machine learning, human resources management

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Authors: Yasmeen A. S. Essawy, Khaled Nassar

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With the rapid increase of complexity in the building industry, professionals in the A/E/C industry were forced to adopt Building Information Modeling (BIM) in order to enhance the communication between the different project stakeholders throughout the project life cycle and create a semantic object-oriented building model that can support geometric-topological analysis of building elements during design and construction. This paper presents a model that extracts topological relationships and geometrical properties of building elements from an existing fully designed BIM, and maps this information into a directed acyclic Elemental Graph Data Model (EGDM). The model incorporates BIM-based search algorithms for automatic deduction of geometrical data and topological relationships for each building element type. Using graph search algorithms, such as Depth First Search (DFS) and topological sortings, all possible construction sequences can be generated and compared against production and construction rules to generate an optimized construction sequence and its associated schedule. The model is implemented in a C# platform.

Keywords: building information modeling (BIM), elemental graph data model (EGDM), geometric and topological data models, graph theory

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Authors: M. A. Grigoryev, A. N. Shishkov, N. V. Savosteenko

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The article identifies optimal path motion of positional electric drive, for example, the feed of cold pilgering mill. It is shown that triangle is the optimum shape of the speed curve, and the ratio of its sides depends on the type of load diagram, in particular from the influence of the main drive of pilgering mill, and is not dependent on the presence of backlash and elasticity in the system. This thesis is proved analytically, and confirmed the results are obtained by a mathematical model that take into account the influence of the main drive-to-drive feed. By statistical analysis of oscillograph traces obtained on the real object allowed to give recommendations on the optimal control of the electric drive feed cold pilgering mill 450. Based on the data that the load torque depends on by hit the pipe in rolls of pilgering mill, occurs in the interval (0,6…0,75) tc, the recommended ratio of start time to the braking time is 2:1. Optimized path motion allowed get up to 25% more RMS torque for the cycle that allowed increased the productivity of the mill.

Keywords: optimal curve speed, positional electric drive, cold pilgering mill 450, optimal path motion

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Authors: Abel Edeowede Abhulimen

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Due to supply irregularity and frequent outages, the need for reliability in power supply has grown unsatisfactorily over time in developing nations, impeding industrialization and fueling insecurity. This article attempts to break down the Nigerian power issue into its numerous sub-sectors in order to pinpoint the industry's ailment and suggest a viable fix. Monthly average performance data were obtained for the various sub-sectors across the industry for eight consecutive quarters. Whereas the amount of energy generated was found to be insufficient to engender industrialization in a nation like Nigeria, the transmission infrastructure was inadequate for the amount of power needed to be wheeled. Additionally, the distribution sub-sector was plagued with problems such as revenue collection inefficiency, severe enough to impede the growth of the entire industry. The country's goal of attaining energy sufficiency and industrialization would significantly be closer to reality with a conscious effort to increase the base of power generation through aggressive investment in Combined Cycle Gas Turbines (CCGT), decentralization of the transmission infrastructure, and strict monitoring of the distribution sub-sector for improved accountability and system reliability.

Keywords: performance, power industry, industrialization, security, energy

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Authors: Meesun Sun, Yongmin Kim

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Estimating maintenance cost is crucial in defense management because it affects military budgets and availability of equipment. When it comes to estimating maintenance cost of the deployed equipment, time series forecasting can be applied with the actual historical cost data. It is more difficult issue to estimate maintenance cost of new equipment for which the actual costs are not provided. In this underlying context, this study proposes an analytical method for maintenance cost estimating relationships (CERs) development of helicopters using linear programming. The CERs can be applied to a new helicopter because they use non-cost independent variables such as the number of engines, the empty weight and so on. In the Republic of Korea, the maintenance cost of new equipment has been usually estimated by reflecting maintenance cost to unit price ratio of the legacy equipment. This study confirms that the CERs perform well for the 10 types of airmobile helicopters in terms of mean absolute percentage error by applying leave-one-out cross-validation. The suggested method is very useful to estimate the maintenance cost of new equipment and can help in the affordability assessment of acquisition program portfolios for total life cycle systems management.

Keywords: affordability analysis, cost estimating relationship, helicopter, linear programming, maintenance cost

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Authors: Soraya Abtouche, Zeyneb Ghoualem, Syrine Daoudi, Lina Ouldmohamed, Xavier Assfeld

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This work reports density functional theory calculations of the optimized geometries, molecular reactivity, energy gap,and thermodynamic properties of the free base (H2P) and their Zn (II) metallated (ZnP), bearing one, two, or three carboxylic acid groups using the hybrid functional B3LYP, Cam-B3lYP, wb97xd with 6-31G(d,p) basis sets. When donating groups are attached to the molecular dye, the bond lengths are slightly decreased, which is important for the easy transfer of an electron from donating to the accepting group. For all dyes, the highest occupied molecular orbital/lowest occupied molecular orbital analysis results in positive outcomes upon electron injection to the semiconductor and subsequent dye regeneration by the electrolyte. The ionization potential increases with increasing conjugation; therefore, the compound dye attached to one carboxylic acid group has the highest ionization potential. The results show higher efficiencies of those sensitized with ZnP. These results have been explained, taking into account the electronic character of the metal ion, which acts as a mediator in the injection step, and, on the other hand, considering the number of anchoring groups to which it binds to the surface of TiO2.

Keywords: DSSC, porphyrin, TD-DFT, electronic properties, donor-acceptor groups

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Authors: Vaso K. Kapnopoulou, Piero Caridis

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The fatigue of ship structural details is of major concern in the maritime industry as it can generate fracture issues that may compromise structural integrity. In the present study, a fatigue analysis of the lower hopper knuckle connection of a bulk carrier was conducted using the Finite Element Method by means of ABAQUS/CAE software. The fatigue life was calculated using Miner’s Rule and the long-term distribution of stress range by the use of the two-parameter Weibull distribution. The cumulative damage ratio was estimated using the fatigue damage resulting from the stress range occurring at each load condition. For this purpose, a cargo hold model was first generated, which extends over the length of two holds (the mid-hold and half of each of the adjacent holds) and transversely over the full breadth of the hull girder. Following that, a submodel of the area of interest was extracted in order to calculate the hot spot stress of the connection and to estimate the fatigue life of the structural detail. Two hot spot locations were identified; one at the top layer of the inner bottom plate and one at the top layer of the hopper plate. The IACS Common Structural Rules (CSR) require that specific dynamic load cases for each loading condition are assessed. Following this, the dynamic load case that causes the highest stress range at each loading condition should be used in the fatigue analysis for the calculation of the cumulative fatigue damage ratio. Each load case has a different effect on ship hull response. Of main concern, when assessing the fatigue strength of the lower hopper knuckle connection, was the determination of the maximum, i.e. the critical value of the stress range, which acts in a direction normal to the weld toe line. This acts in the transverse direction, that is, perpendicularly to the ship's centerline axis. The load cases were explored both theoretically and numerically in order to establish the one that causes the highest damage to the location examined. The most severe one was identified to be the load case induced by beam sea condition where the encountered wave comes from the starboard. At the level of the cargo hold model, the model was assumed to be simply supported at its ends. A coarse mesh was generated in order to represent the overall stiffness of the structure. The elements employed were quadrilateral shell elements, each having four integration points. A linear elastic analysis was performed because linear elastic material behavior can be presumed, since only localized yielding is allowed by most design codes. At the submodel level, the displacements of the analysis of the cargo hold model to the outer region nodes of the submodel acted as boundary conditions and applied loading for the submodel. In order to calculate the hot spot stress at the hot spot locations, a very fine mesh zone was generated and used. The fatigue life of the detail was found to be 16.4 years which is lower than the design fatigue life of the structure (25 years), making this location vulnerable to fatigue fracture issues. Moreover, the loading conditions that induce the most damage to the location were found to be the various ballasting conditions.

Keywords: dynamic load cases, finite element method, high cycle fatigue, lower hopper knuckle

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Authors: Junaid Bin Aamir, Ma Fanhua

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Methanol is one of the most suitable alternative fuels for replacing gasoline in present and future spark-ignited engines. However, for pure methanol engines, cold start problems and misfires are observed under certain operating conditions. Hydrogen provides a solution for such problems. This paper experimentally investigated the effect of hydrogen on the performance of a pure methanol SI-engine at city driving conditions (1500 rpm speed and 1.18 excess air ratio). Hydrogen was used as a part of methanol reformed syngas (67% hydrogen by volume). 4% by mass of the total methanol converted to hydrogen and other constituent gases, was used in each cycle. Port fuel injection was used to inject methanol and hydrogen-rich syngas into the 4-cylinder engine. The results indicated an increase in brake thermal efficiency up to 5% with the addition of hydrogen, a decrease in brake specific fuel consumption up to 200 g/kWh, and a decrease in exhaust gas temperature by 100°C for all mean effective pressures. Hydrogen addition also decreased harmful exhaust emissions significantly. There was a reduction in THC emissions up to 95% and CO emissions up to 50%. NOx emissions were slightly increased (up to 15%), but they can be reduced to zero by lean burn strategy.

Keywords: alternative fuels, hydrogen, methanol, performance, spark ignition engines

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Authors: Sun-Young Jang, Sung-Ah Kim, Dongyoun Shin

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Current real-estate value estimation, difficult for laymen, usually is performed by specialists. This paper presents an automated estimation process based on big data and machine-learning technology that calculates influences of building conditions on real-estate price measurement. The present study analyzed actual building sales sample data for Nonhyeon-dong, Gangnam-gu, Seoul, Korea, measuring the major influencing factors among the various building conditions. Further to that analysis, a prediction model was established and applied using RapidMiner Studio, a graphical user interface (GUI)-based tool for derivation of machine-learning prototypes. The prediction model is formulated by reference to previous examples. When new examples are applied, it analyses and predicts accordingly. The analysis process discerns the crucial factors effecting price increases by calculation of weighted values. The model was verified, and its accuracy determined, by comparing its predicted values with actual price increases.

Keywords: apartment complex, big data, life-cycle building value analysis, machine learning

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Authors: Alexander de Tomás, Miquel Sierra, Stefan Pfenninger, Francesco Lombardi, Ines Campos, Cristina Madrid

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Environmental parameters are key in the definition of sustainable energy systems yet excluded from most energy system optimization models. Still, decision-making may be misleading without considering them. Environmental analyses of the energy transition are a key part of industrial ecology but often are performed without any input from the users of the information. This work assesses the systemic impacts of energy transition pathways in Portugal. Using the Calliope energy modeling framework, 250+ optimized energy system pathways are generated. A Delphi study helps to identify the relevant criteria for the stakeholders as regards the environmental assessment, which is performed with ENBIOS, a python package that integrates life cycle assessment (LCA) with a metabolic analysis based on complex relations. Furthermore, this study focuses on how the uncertainty propagates through the model’s consortium. With the aim of doing so, a soft link between the Calliope/ENBIOS cascade and Brightway’s data capabilities is built to perform Monte Carlo simulations. These findings highlight the relevance of including uncertainty analysis as a range of values rather than informing energy transition results with a single value.

Keywords: energy transition, energy modeling, uncertainty, sustainability

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Authors: I. Inthanongsone, C. Drebenstedt, J. C. Bongaerts, P. Sontamino

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The major concern in evaluating the value of mining projects related to the deficiency of the traditional discounted cash flow (DCF) method. This method does not take uncertainties into account and, hence it does not allow for an economic assessment of managerial flexibility and operational adaptability, which are increasingly determining long-term corporate success. Such an assessment can be performed with the real options valuation (ROV) approach, since it allows for a comparative evaluation of unforeseen uncertainties in a project life cycle. This paper presents an economic evaluation model for open pit mining projects based on real options valuation approach. Uncertainties in the model are caused by metal prices and cost uncertainties and the system dynamics (SD) modeling method is used to structure and solve the real options model. The model is applied to a case study. It can be shown that that managerial flexibility reacting to uncertainties may create additional value to a mining project in comparison to the outcomes of a DCF method. One important insight for management dealing with uncertainty is seen in choosing the optimal time to exercise strategic options.

Keywords: DCF methods, ROV approach, system dynamics modeling methods, uncertainty

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Authors: Betty Makena, Tsegaye Tadesse, Mark Svoboda

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Global warming has intensified the frequency and intensity of extreme climate disasters and led to unpredictable weather conditions. Consequently, rapid shifts between drought and floods, known as Drought-Flood Abrupt Alteration (DFAA), have become increasingly common. DFAA results in superimposed impacts of drought and floods within a short period, exacerbating the effects of the floods or drought event. Current disaster management plans often overlook DFAA events, as they primarily focus on either floods or drought. Therefore, effectively identifying DFAA events is crucial for developing effective mitigation strategies. This study aims to identify historical DFAA events in Kenya using the Long Cycle Drought-Flood Abrupt Alteration Index (LDFAI). The research will analyze the spatial distribution, temporal variation, and intensity of DFAA events from 1990 to 2023, as well as their socio-economic impacts. Understanding these events is important to develop more effective strategies to address the impacts of DFAA events. Findings from this study will inform decision making to develop coping strategies to mitigate the adverse effects of DFAA in Kenya.

Keywords: abrupt, alteration, drought, floods

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Authors: Salma Aboussalam, Karima Khalil, Khalid Elkalay

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In order to understand the structure, functioning, and current state of the Moroccan Mediterranean Sea ecosystem, an Ecopath mass balance model was applied. The model was based on 31 functional groups, which included 21 fish species, 7 invertebrates, 2 primary producers, and one detritus group. The trophic interactions between these groups were analyzed, and the system's average trophic transfer efficiency was found to be 23%. The total primary production and total respiration were calculated to be greater than 1, indicating that the system produces more energy than it respires. The ecosystem was found to have a high level of respiration and consumption flows, and indicators of stability and development showed low values for the Finn cycle index (13.97), system omnivory index (0.18), and average Finn path length (3.09), indicating that the ecosystem is disturbed and has a linear rather than web-like trophic structure. Keystone species were identified using the keystone index and mixed trophic impact analysis, with other demersal invertebrates, zooplankton, and cephalopods found to have a significant impact on other groups.

Keywords: ecopath, food web, trophic flux, moroccan mediterranean sea

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Authors: Ebrahim Solgi, Zahra Hamedani, Behrouz Mohammad Kari, Ruwan Fernando, Henry Skates

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The use of thermal energy storage (TES) as part of a passive design strategy can reduce a building’s energy demand. TES materials do this by increasing the lag between energy consumption and energy supply by absorbing, storing and releasing energy in a controlled manner. The increase of lightweight construction in the building industry has made it harder to utilize thermal mass. Consequently, Phase Change Materials (PCMs) are a promising alternative as they can be manufactured in thin layers and used with lightweight construction to store latent heat. This research investigates utilizing PCMs, with the first step being measuring their performance under experimental conditions. To do this requires three components. The first is a calorimeter for measuring indoor thermal conditions, the second is a pyranometer for recording the solar conditions: global, diffuse and direct radiation and the third is a data-logger for recording temperature and humidity for the studied period. This paper reports on the design and implementation of an experimental setup used to measure the thermal characteristics of PCMs as part of a wall construction. The experimental model has been simulated with the software EnergyPlus to create a reliable simulation model that warrants further investigation.

Keywords: phase change materials, EnergyPlus, experimental evaluation, night ventilation

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Authors: Paul Ojeaga

Abstract:

Can the level of innovation use drive un-validated business models across regions? To what extent does industrial sector attractiveness drive firm’s success across regions at the time of start-up? This study examines the role of innovation on start-up success in six regions of the world (namely Sub Saharan Africa, the Middle East and North Africa, Latin America, South East Asia Pacific, the European Union and the United States representing North America) using macroeconomic variables. While there have been studies using firm level data, results from such studies are not suitable for national policy decisions. The need to drive a regional innovation policy also begs for an answer, therefore providing room for this study. Results using dynamic panel estimation show that innovation counts in the early infancy stage of new business life cycle. The results are robust even after controlling for time fixed effects and the study present variance-covariance estimation robust standard errors.

Keywords: industrial economics, un-validated business models, scalable models, entrepreneurship

Procedia PDF Downloads 276

Authors: Shadab Shishegar, Sophie Duchesne, Genevieve Pelletier

Abstract:

Sustainability as one of the key elements of Smart cities, can be realized by employing Real Time Control Strategies for city’s infrastructures. Nowadays Stormwater management systems play an important role in mitigating the impacts of urbanization on natural hydrological cycle. These systems can be managed in such a way that they meet the smart cities standards. In fact, there is a huge potential for sustainable management of urban stormwater and also its adaptability to global challenges like climate change. Hence, a dynamically managed system that can adapt itself to instability of the environmental conditions is desirable. A Global Predictive Real Time Control approach is proposed in this paper to optimize the performance of stormwater management basins in terms of flooding prevention. To do so, a mathematical optimization model is developed then solved using Genetic Algorithm (GA). Results show an improved performance at system-level for the stormwater basins in comparison to static strategy.

Keywords: environmental sustainability, optimization, real time control, storm water management

Procedia PDF Downloads 169

Authors: Anurakti Shukla, Sudhakar Srivastava

Abstract:

Cyanobacteria are known for rapid growth rates, high biomass, and the ability to accumulate potentially toxic elements and contaminants. The present work was planned to develop a low-cost, feasible prototype, CyanoClean, for the growth of a cyanobacterial consortium for the removal of arsenic (As) from water. The cyanobacterial consortium consisting of Oscillatoria, Phormidiumand Gloeotrichiawas used, and the conditions for optimal growth of the consortium were standardized. A pH of 7.6, initial cyanobacterial biomass of 10 g/L, and arsenite [As(III)] and arsenate [As(V)] concentration of 400 μΜand 600 μM, respectively, were found to be suitable. The CyanoClean prototype was designed with acrylic sheet and had arrangements for optimal cyanobacterial growth in natural sunlight and also in artificial light. The As removal experiments in concentration- and duration-dependent manner demonstrated removal of up to 39-69% and 9-33% As respectively from As(III) and As(V)-contaminated water. In field testing of CyanoClean, natural As-contaminated groundwater was used, and As reduction was monitored when a flow rate of 3 L/h was maintained. In a field experiment, As concentration in groundwater was found to reduce from 102.43 μg L⁻¹ to <10 μg L⁻¹ after 6 h in natural sunlight. However, in shaded conditions under artificial light, the same result was achieved after 9 h. The CyanoClean prototype is of simple design and can be easily up-scaled for application at a small- to medium-size land and shall be affordable even for a low- to middle-income group farmer.

Keywords: cyanoclean, gloeotrichia, oscillatoria, phormidium, phycoremediation

Procedia PDF Downloads 133