Search results for: Li-ion battery packs modeling optimized
Commenced in January 2007
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Edition: International
Paper Count: 5973

Search results for: Li-ion battery packs modeling optimized

993 Influence of Travel Time Reliability on Elderly Drivers Crash Severity

Authors: Ren Moses, Emmanuel Kidando, Eren Ozguven, Yassir Abdelrazig

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Although older drivers (defined as those of age 65 and above) are less involved with speeding, alcohol use as well as night driving, they are more vulnerable to severe crashes. The major contributing factors for severe crashes include frailty and medical complications. Several studies have evaluated the contributing factors on severity of crashes. However, few studies have established the impact of travel time reliability (TTR) on road safety. In particular, the impact of TTR on senior adults who face several challenges including hearing difficulties, decreasing of the processing skills and cognitive problems in driving is not well established. Therefore, this study focuses on determining possible impacts of TTR on the traffic safety with focus on elderly drivers. Historical travel speed data from freeway links in the study area were used to calculate travel time and the associated TTR metrics that is, planning time index, the buffer index, the standard deviation of the travel time and the probability of congestion. Four-year information on crashes occurring on these freeway links was acquired. The binary logit model estimated using the Markov Chain Monte Carlo (MCMC) sampling technique was used to evaluate variables that could be influencing elderly crash severity. Preliminary results of the analysis suggest that TTR is statistically significant in affecting the severity of a crash involving an elderly driver. The result suggests that one unit increase in the probability of congestion reduces the likelihood of the elderly severe crash by nearly 22%. These findings will enhance the understanding of TTR and its impact on the elderly crash severity.

Keywords: highway safety, travel time reliability, elderly drivers, traffic modeling

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992 Metalorganic Chemical Vapor Deposition Overgrowth on the Bragg Grating for Gallium Nitride Based Distributed Feedback Laser

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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991 Tectono-Thermal Evolution of Ningwu-Jingle Basin in North China Craton: Constraints from Apatite (U–Th-Sm)/He and Fission Track Thermochronology

Authors: Zhibin Lei, Minghui Yang

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Ningwu-Jingle basin is a structural syncline which has undergone a complex tectono-thermal history since Cretaceous. It stretches along the strike of the northern Lvliang Mountains which are the most important mountains in the middle and west of North China Craton. The Mesozoic units make up of the core of Ningwu-Jingle Basin, with pre-Mesozoic units making up of its flanks. The available low-temperature thermochronology implies that Ningwu-Jingle Basin has experienced two stages of uplifting: 94±7Ma to 111±8Ma (Albian to Cenomanian) and 62±4 to 75±5Ma (Danian to Maastrichtian). In order to constrain its tectono-thermal history in the Cenozoic, both apatite (U-Th-Sm)/He and fission track dating analysis are applied on 3 Middle Jurassic and 3 Upper Triassic sandstone samples. The central fission track ages range from 74.4±8.8Ma to 66.0±8.0Ma (Campanian to Maastrichtian) which matches well with previous data. The central He ages range from 20.1±1.2Ma to 49.1±3.0Ma (Ypresian to Burdigalian). Inverse thermal modeling is established based on both apatite fission track data and (U-Th-Sm)/He data. The thermal history obtained reveals that all 6 sandstone samples cross the high-temperature limit of fission track partial annealing zone by the uppermost Cretaceous and that of He partial retention zone by the uppermost Eocene to the early Oligocene. The result indicates that the middle and west of North China Craton is not stable in the Cenozoic.

Keywords: apatite fission track thermochronology, apatite (u–th)/he thermochronology, Ningwu-Jingle basin, North China craton, tectono-thermal history

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990 Classical and Bayesian Inference of the Generalized Log-Logistic Distribution with Applications to Survival Data

Authors: Abdisalam Hassan Muse, Samuel Mwalili, Oscar Ngesa

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A generalized log-logistic distribution with variable shapes of the hazard rate was introduced and studied, extending the log-logistic distribution by adding an extra parameter to the classical distribution, leading to greater flexibility in analysing and modeling various data types. The proposed distribution has a large number of well-known lifetime special sub-models such as; Weibull, log-logistic, exponential, and Burr XII distributions. Its basic mathematical and statistical properties were derived. The method of maximum likelihood was adopted for estimating the unknown parameters of the proposed distribution, and a Monte Carlo simulation study is carried out to assess the behavior of the estimators. The importance of this distribution is that its tendency to model both monotone (increasing and decreasing) and non-monotone (unimodal and bathtub shape) or reversed “bathtub” shape hazard rate functions which are quite common in survival and reliability data analysis. Furthermore, the flexibility and usefulness of the proposed distribution are illustrated in a real-life data set and compared to its sub-models; Weibull, log-logistic, and BurrXII distributions and other parametric survival distributions with 3-parmaeters; like the exponentiated Weibull distribution, the 3-parameter lognormal distribution, the 3- parameter gamma distribution, the 3-parameter Weibull distribution, and the 3-parameter log-logistic (also known as shifted log-logistic) distribution. The proposed distribution provided a better fit than all of the competitive distributions based on the goodness-of-fit tests, the log-likelihood, and information criterion values. Finally, Bayesian analysis and performance of Gibbs sampling for the data set are also carried out.

Keywords: hazard rate function, log-logistic distribution, maximum likelihood estimation, generalized log-logistic distribution, survival data, Monte Carlo simulation

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989 Ontology-Driven Knowledge Discovery and Validation from Admission Databases: A Structural Causal Model Approach for Polytechnic Education in Nigeria

Authors: Bernard Igoche Igoche, Olumuyiwa Matthew, Peter Bednar, Alexander Gegov

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This study presents an ontology-driven approach for knowledge discovery and validation from admission databases in Nigerian polytechnic institutions. The research aims to address the challenges of extracting meaningful insights from vast amounts of admission data and utilizing them for decision-making and process improvement. The proposed methodology combines the knowledge discovery in databases (KDD) process with a structural causal model (SCM) ontological framework. The admission database of Benue State Polytechnic Ugbokolo (Benpoly) is used as a case study. The KDD process is employed to mine and distill knowledge from the database, while the SCM ontology is designed to identify and validate the important features of the admission process. The SCM validation is performed using the conditional independence test (CIT) criteria, and an algorithm is developed to implement the validation process. The identified features are then used for machine learning (ML) modeling and prediction of admission status. The results demonstrate the adequacy of the SCM ontological framework in representing the admission process and the high predictive accuracies achieved by the ML models, with k-nearest neighbors (KNN) and support vector machine (SVM) achieving 92% accuracy. The study concludes that the proposed ontology-driven approach contributes to the advancement of educational data mining and provides a foundation for future research in this domain.

Keywords: admission databases, educational data mining, machine learning, ontology-driven knowledge discovery, polytechnic education, structural causal model

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988 Mapping of Geological Structures Using Aerial Photography

Authors: Ankit Sharma, Mudit Sachan, Anurag Prakash

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Rapid growth in data acquisition technologies through drones, have led to advances and interests in collecting high-resolution images of geological fields. Being advantageous in capturing high volume of data in short flights, a number of challenges have to overcome for efficient analysis of this data, especially while data acquisition, image interpretation and processing. We introduce a method that allows effective mapping of geological fields using photogrammetric data of surfaces, drainage area, water bodies etc, which will be captured by airborne vehicles like UAVs, we are not taking satellite images because of problems in adequate resolution, time when it is captured may be 1 yr back, availability problem, difficult to capture exact image, then night vision etc. This method includes advanced automated image interpretation technology and human data interaction to model structures and. First Geological structures will be detected from the primary photographic dataset and the equivalent three dimensional structures would then be identified by digital elevation model. We can calculate dip and its direction by using the above information. The structural map will be generated by adopting a specified methodology starting from choosing the appropriate camera, camera’s mounting system, UAVs design ( based on the area and application), Challenge in air borne systems like Errors in image orientation, payload problem, mosaicing and geo referencing and registering of different images to applying DEM. The paper shows the potential of using our method for accurate and efficient modeling of geological structures, capture particularly from remote, of inaccessible and hazardous sites.

Keywords: digital elevation model, mapping, photogrammetric data analysis, geological structures

Procedia PDF Downloads 683
987 Modeling Flow and Deposition Characteristics of Solid CO2 during Choked Flow of CO2 Pipeline in CCS

Authors: Teng lin, Li Yuxing, Han Hui, Zhao Pengfei, Zhang Datong

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With the development of carbon capture and storage (CCS), the flow assurance of CO2 transportation becomes more important, particularly for supercritical CO2 pipelines. The relieving system using the choke valve is applied to control the pressure in CO2 pipeline. However, the temperature of fluid would drop rapidly because of Joule-Thomson cooling (JTC), which may cause solid CO2 form and block the pipe. In this paper, a Computational Fluid Dynamic (CFD) model, using the modified Lagrangian method, Reynold's Stress Transport model (RSM) for turbulence and stochastic tracking model (STM) for particle trajectory, was developed to predict the deposition characteristic of solid carbon dioxide. The model predictions were in good agreement with the experiment data published in the literature. It can be observed that the particle distribution affected the deposition behavior. In the region of the sudden expansion, the smaller particles accumulated tightly on the wall were dominant for pipe blockage. On the contrary, the size of solid CO2 particles deposited near the outlet usually was bigger and the stacked structure was looser. According to the calculation results, the movement of the particles can be regarded as the main four types: turbulent motion close to the sudden expansion structure, balanced motion at sudden expansion-middle region, inertial motion near the outlet and the escape. Furthermore the particle deposits accumulated primarily in the sudden expansion region, reattachment region and outlet region because of the four type of motion. Also the Stokes number had an effect on the deposition ratio and it is recommended for Stokes number to avoid 3-8St.

Keywords: carbon capture and storage, carbon dioxide pipeline, gas-particle flow, deposition

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986 Short-Term Forecast of Wind Turbine Production with Machine Learning Methods: Direct Approach and Indirect Approach

Authors: Mamadou Dione, Eric Matzner-lober, Philippe Alexandre

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The Energy Transition Act defined by the French State has precise implications on Renewable Energies, in particular on its remuneration mechanism. Until then, a purchase obligation contract permitted the sale of wind-generated electricity at a fixed rate. Tomorrow, it will be necessary to sell this electricity on the Market (at variable rates) before obtaining additional compensation intended to reduce the risk. This sale on the market requires to announce in advance (about 48 hours before) the production that will be delivered on the network, so to be able to predict (in the short term) this production. The fundamental problem remains the variability of the Wind accentuated by the geographical situation. The objective of the project is to provide, every day, short-term forecasts (48-hour horizon) of wind production using weather data. The predictions of the GFS model and those of the ECMWF model are used as explanatory variables. The variable to be predicted is the production of a wind farm. We do two approaches: a direct approach that predicts wind generation directly from weather data, and an integrated approach that estimâtes wind from weather data and converts it into wind power by power curves. We used machine learning techniques to predict this production. The models tested are random forests, CART + Bagging, CART + Boosting, SVM (Support Vector Machine). The application is made on a wind farm of 22MW (11 wind turbines) of the Compagnie du Vent (that became Engie Green France). Our results are very conclusive compared to the literature.

Keywords: forecast aggregation, machine learning, spatio-temporal dynamics modeling, wind power forcast

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985 Interaction between Space Syntax and Agent-Based Approaches for Vehicle Volume Modelling

Authors: Chuan Yang, Jing Bie, Panagiotis Psimoulis, Zhong Wang

Abstract:

Modelling and understanding vehicle volume distribution over the urban network are essential for urban design and transport planning. The space syntax approach was widely applied as the main conceptual and methodological framework for contemporary vehicle volume models with the help of the statistical method of multiple regression analysis (MRA). However, the MRA model with space syntax variables shows a limitation in vehicle volume predicting in accounting for the crossed effect of the urban configurational characters and socio-economic factors. The aim of this paper is to construct models by interacting with the combined impact of the street network structure and socio-economic factors. In this paper, we present a multilevel linear (ML) and an agent-based (AB) vehicle volume model at an urban scale interacting with space syntax theoretical framework. The ML model allowed random effects of urban configurational characteristics in different urban contexts. And the AB model was developed with the incorporation of transformed space syntax components of the MRA models into the agents’ spatial behaviour. Three models were implemented in the same urban environment. The ML model exhibit superiority over the original MRA model in identifying the relative impacts of the configurational characters and macro-scale socio-economic factors that shape vehicle movement distribution over the city. Compared with the ML model, the suggested AB model represented the ability to estimate vehicle volume in the urban network considering the combined effects of configurational characters and land-use patterns at the street segment level.

Keywords: space syntax, vehicle volume modeling, multilevel model, agent-based model

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984 Optimizing Recycling and Reuse Strategies for Circular Construction Materials with Life Cycle Assessment

Authors: Zhongnan Ye, Xiaoyi Liu, Shu-Chien Hsu

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Rapid urbanization has led to a significant increase in construction and demolition waste (C&D waste), underscoring the need for sustainable waste management strategies in the construction industry. Aiming to enhance the sustainability of urban construction practices, this study develops an optimization model to effectively suggest the optimal recycling and reuse strategies for C&D waste, including concrete and steel. By employing Life Cycle Assessment (LCA), the model evaluates the environmental impacts of adopted construction materials throughout their lifecycle. The model optimizes the quantity of materials to recycle or reuse, the selection of specific recycling and reuse processes, and logistics decisions related to the transportation and storage of recycled materials with the objective of minimizing the overall environmental impact, quantified in terms of carbon emissions, energy consumption, and associated costs, while adhering to a range of constraints. These constraints include capacity limitations, quality standards for recycled materials, compliance with environmental regulations, budgetary limits, and temporal considerations such as project deadlines and material availability. The strategies are expected to be both cost-effective and environmentally beneficial, promoting a circular economy within the construction sector, aligning with global sustainability goals, and providing a scalable framework for managing construction waste in densely populated urban environments. The model is helpful in reducing the carbon footprint of construction projects, conserving valuable resources, and supporting the industry’s transition towards a more sustainable future.

Keywords: circular construction, construction and demolition waste, material recycling, optimization modeling

Procedia PDF Downloads 53
983 Text Mining of Veterinary Forums for Epidemiological Surveillance Supplementation

Authors: Samuel Munaf, Kevin Swingler, Franz Brülisauer, Anthony O’Hare, George Gunn, Aaron Reeves

Abstract:

Web scraping and text mining are popular computer science methods deployed by public health researchers to augment traditional epidemiological surveillance. However, within veterinary disease surveillance, such techniques are still in the early stages of development and have not yet been fully utilised. This study presents an exploration into the utility of incorporating internet-based data to better understand the smallholder farming communities within Scotland by using online text extraction and the subsequent mining of this data. Web scraping of the livestock fora was conducted in conjunction with text mining of the data in search of common themes, words, and topics found within the text. Results from bi-grams and topic modelling uncover four main topics of interest within the data pertaining to aspects of livestock husbandry: feeding, breeding, slaughter, and disposal. These topics were found amongst both the poultry and pig sub-forums. Topic modeling appears to be a useful method of unsupervised classification regarding this form of data, as it has produced clusters that relate to biosecurity and animal welfare. Internet data can be a very effective tool in aiding traditional veterinary surveillance methods, but the requirement for human validation of said data is crucial. This opens avenues of research via the incorporation of other dynamic social media data, namely Twitter and Facebook/Meta, in addition to time series analysis to highlight temporal patterns.

Keywords: veterinary epidemiology, disease surveillance, infodemiology, infoveillance, smallholding, social media, web scraping, sentiment analysis, geolocation, text mining, NLP

Procedia PDF Downloads 91
982 Political Regimes, Political Stability and Debt Dependence in African Countries of Franc Zone: A Logistic Modeling

Authors: Nounamo Nguedie Yann Harold

Abstract:

The factors behind the debt have been the subject of several studies in the literature. Pioneering studies based on the 'double deficit' approach linked indebtedness to the imbalance between savings and investment, the budget deficit and the current account deficit. Most studies on identifying factors that may stimulate or reduce the level of external public debt agree that the following variables are important explanatory variables in leveraging debt: the budget deficit, trade opening, current account and exchange rate, import, export, interest rate, term variation exchange rate, economic growth rate and debt service, capital flight, and over-indebtedness. Few studies addressed the impact of political factors on the level of external debt. In general, however, the IMF's stabilization programs in developing countries following the debt crisis have resulted in economic recession and the advent of political crises that have resulted in changes in governments. In this sense, political institutions are recognised as factors of accumulation of external debt in most developing countries. This paper assesses the role of political factors on the external debt level of African countries in the Franc Zone over the period 1985-2016. Data used come from World Bank and ICRG. Using a logit in panel, the results show that the more a country is politically stable, the lower the external debt compared to the gross domestic product. Political stability multiplies 1.18% the chances of being in the sustainable debt zone. For example, countries with good political institutions experience less severe external debt burdens than countries with bad political institutions.

Keywords: African countries, external debt, Franc Zone, political factors

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981 Mechanical Properties of Diamond Reinforced Ni Nanocomposite Coatings Made by Co-Electrodeposition with Glycine as Additive

Authors: Yanheng Zhang, Lu Feng, Yilan Kang, Donghui Fu, Qian Zhang, Qiu Li, Wei Qiu

Abstract:

Diamond-reinforced Ni matrix composite has been widely applied in engineering for coating large-area structural parts owing to its high hardness, good wear resistance and corrosion resistance compared with those features of pure nickel. The mechanical properties of Ni-diamond composite coating can be promoted by the high incorporation and uniform distribution of diamond particles in the nickel matrix, while the distribution features of particles are affected by electrodeposition process parameters, especially the additives in the plating bath. Glycine has been utilized as an organic additive during the preparation of pure nickel coating, which can effectively increase the coating hardness. Nevertheless, to author’s best knowledge, no research about the effects of glycine on the Ni-diamond co-deposition has been reported. In this work, the diamond reinforced Ni nanocomposite coatings were fabricated by a co-electrodeposition technique from a modified Watt’s type bath in the presence of glycine. After preparation, the SEM morphology of the composite coatings was observed combined with energy dispersive X-ray spectrometer, and the diamond incorporation was analyzed. The surface morphology and roughness were obtained by a three-dimensional profile instrument. 3D-Debye rings formed by XRD were analyzed to characterize the nickel grain size and orientation in the coatings. The average coating thickness was measured by a digital micrometer to deduce the deposition rate. The microhardness was tested by automatic microhardness tester. The friction coefficient and wear volume were measured by reciprocating wear tester to characterize the coating wear resistance and cutting performance. The experimental results confirmed that the presence of glycine effectively improved the surface morphology and roughness of the composite coatings. By optimizing the glycine concentration, the incorporation of diamond particles was increased, while the nickel grain size decreased with increasing glycine. The hardness of the composite coatings was increased as the glycine concentration increased. The friction and wear properties were evaluated as the glycine concentration was optimized, showing a decrease in the wear volume. The wear resistance of the composite coatings increased as the glycine content was increased to an optimum value, beyond which the wear resistance decreased. Glycine complexation contributed to the nickel grain refinement and improved the diamond dispersion in the coatings, both of which made a positive contribution to the amount and uniformity of embedded diamond particles, thus enhancing the microhardness, reducing the friction coefficient, and hence increasing the wear resistance of the composite coatings. Therefore, additive glycine can be used during the co-deposition process to improve the mechanical properties of protective coatings.

Keywords: co-electrodeposition, glycine, mechanical properties, Ni-diamond nanocomposite coatings

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980 Human Resource Practices and Organization Knowledge Capability: An Exploratory Study Applied to Private Organization

Authors: Mamoona Rasheed, Salman Iqbal, Muhammad Abdullah

Abstract:

Organizational capability, in terms of employees’ knowledge is valuable, and difficult to reproduce; and help to build sustainable competitive advantages. Knowledge capability is linked with human resource (HR) practices of an organization. This paper investigates the relationship between HR practices, knowledge management and organization capability. In an organization, employees play key role for the effective organizational performance by sharing their knowledge with management and co-workers that contributes towards organization capability. Pakistan being a developing country has different HR practices and culture. The business opportunities give rise to the discussion about the effect of HR practices on knowledge management and organization capability as innovation performance. An empirical study is conducted through questionnaires form the employees in private banks of Lahore, Pakistan. The data is collected via structured questionnaire with a sample of 120 cases. Data is analyzed using Structure Equation Modeling (SEM), and results are depicted using AMOS software. Results of this study are tabulated, interpreted and crosschecked with other studies. Findings suggest that there is a positive relationship of training & development along with incentives on knowledge management. On the other hand, employee’s participation has insignificant association with knowledge management. In addition, knowledge management has also positive association with organization capability. In line with the previous research, it is suggested that knowledge management is important for improving the organizational capability such as innovation performance and knowledge capacity of firm. Organization capability may improve significantly once specific HR practices are properly established and implemented by HR managers. This Study has key implications for knowledge management and innovation fields theoretically and practically.

Keywords: employee participation, incentives, knowledge management, organization capability, training and development

Procedia PDF Downloads 155
979 Using Open Source Data and GIS Techniques to Overcome Data Deficiency and Accuracy Issues in the Construction and Validation of Transportation Network: Case of Kinshasa City

Authors: Christian Kapuku, Seung-Young Kho

Abstract:

An accurate representation of the transportation system serving the region is one of the important aspects of transportation modeling. Such representation often requires developing an abstract model of the system elements, which also requires important amount of data, surveys and time. However, in some cases such as in developing countries, data deficiencies, time and budget constraints do not always allow such accurate representation, leaving opportunities to assumptions that may negatively affect the quality of the analysis. With the emergence of Internet open source data especially in the mapping technologies as well as the advances in Geography Information System, opportunities to tackle these issues have raised. Therefore, the objective of this paper is to demonstrate such application through a practical case of the development of the transportation network for the city of Kinshasa. The GIS geo-referencing was used to construct the digitized map of Transportation Analysis Zones using available scanned images. Centroids were then dynamically placed at the center of activities using an activities density map. Next, the road network with its characteristics was built using OpenStreet data and other official road inventory data by intersecting their layers and cleaning up unnecessary links such as residential streets. The accuracy of the final network was then checked, comparing it with satellite images from Google and Bing. For the validation, the final network was exported into Emme3 to check for potential network coding issues. Results show a high accuracy between the built network and satellite images, which can mostly be attributed to the use of open source data.

Keywords: geographic information system (GIS), network construction, transportation database, open source data

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978 Experimental Monitoring of the Parameters of the Ionosphere in the Local Area Using the Results of Multifrequency GNSS-Measurements

Authors: Andrey Kupriyanov

Abstract:

In recent years, much attention has been paid to the problems of ionospheric disturbances and their influence on the signals of global navigation satellite systems (GNSS) around the world. This is due to the increase in solar activity, the expansion of the scope of GNSS, the emergence of new satellite systems, the introduction of new frequencies and many others. The influence of the Earth's ionosphere on the propagation of radio signals is an important factor in many applied fields of science and technology. The paper considers the application of the method of transionospheric sounding using measurements from signals from Global Navigation Satellite Systems to determine the TEC distribution and scintillations of the ionospheric layers. To calculate these parameters, the International Reference Ionosphere (IRI) model of the ionosphere, refined in the local area, is used. The organization of operational monitoring of ionospheric parameters is analyzed using several NovAtel GPStation6 base stations. It allows performing primary processing of GNSS measurement data, calculating TEC and fixing scintillation moments, modeling the ionosphere using the obtained data, storing data and performing ionospheric correction in measurements. As a result of the study, it was proved that the use of the transionospheric sounding method for reconstructing the altitude distribution of electron concentration in different altitude range and would provide operational information about the ionosphere, which is necessary for solving a number of practical problems in the field of many applications. Also, the use of multi-frequency multisystem GNSS equipment and special software will allow achieving the specified accuracy and volume of measurements.

Keywords: global navigation satellite systems (GNSS), GPstation6, international reference ionosphere (IRI), ionosphere, scintillations, total electron content (TEC)

Procedia PDF Downloads 175
977 Secure Optimized Ingress Filtering in Future Internet Communication

Authors: Bander Alzahrani, Mohammed Alreshoodi

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Information-centric networking (ICN) using architectures such as the Publish-Subscribe Internet Technology (PURSUIT) has been proposed as a new networking model that aims at replacing the current used end-centric networking model of the Internet. This emerged model focuses on what is being exchanged rather than which network entities are exchanging information, which gives the control plane functions such as routing and host location the ability to be specified according to the content items. The forwarding plane of the PURSUIT ICN architecture uses a simple and light mechanism based on Bloom filter technologies to forward the packets. Although this forwarding scheme solve many problems of the today’s Internet such as the growth of the routing table and the scalability issues, it is vulnerable to brute force attacks which are starting point to distributed- denial-of-service (DDoS) attacks. In this work, we design and analyze a novel source-routing and information delivery technique that keeps the simplicity of using Bloom filter-based forwarding while being able to deter different attacks such as denial of service attacks at the ingress of the network. To achieve this, special forwarding nodes called Edge-FW are directly attached to end user nodes and used to perform a security test for malicious injected random packets at the ingress of the path to prevent any possible attack brute force attacks at early stage. In this technique, a core entity of the PURSUIT ICN architecture called topology manager, that is responsible for finding shortest path and creating a forwarding identifiers (FId), uses a cryptographically secure hash function to create a 64-bit hash, h, over the formed FId for authentication purpose to be included in the packet. Our proposal restricts the attacker from injecting packets carrying random FIds with a high amount of filling factor ρ, by optimizing and reducing the maximum allowed filling factor ρm in the network. We optimize the FId to the minimum possible filling factor where ρ ≤ ρm, while it supports longer delivery trees, so the network scalability is not affected by the chosen ρm. With this scheme, the filling factor of any legitimate FId never exceeds the ρm while the filling factor of illegitimate FIds cannot exceed the chosen small value of ρm. Therefore, injecting a packet containing an FId with a large value of filling factor, to achieve higher attack probability, is not possible anymore. The preliminary analysis of this proposal indicates that with the designed scheme, the forwarding function can detect and prevent malicious activities such DDoS attacks at early stage and with very high probability.

Keywords: forwarding identifier, filling factor, information centric network, topology manager

Procedia PDF Downloads 149
976 Numerical and Sensitivity Analysis of Modeling the Newcastle Disease Dynamics

Authors: Nurudeen Oluwasola Lasisi

Abstract:

Newcastle disease is a highly contagious disease of birds caused by a para-myxo virus. In this paper, we presented Novel quarantine-adjusted incident and linear incident of Newcastle disease model equations. We considered the dynamics of transmission and control of Newcastle disease. The existence and uniqueness of the solutions were obtained. The existence of disease-free points was shown, and the model threshold parameter was examined using the next-generation operator method. The sensitivity analysis was carried out in order to identify the most sensitive parameters of the disease transmission. This revealed that as parameters β,ω, and ᴧ increase while keeping other parameters constant, the effective reproduction number R_ev increases. This implies that the parameters increase the endemicity of the infection of individuals. More so, when the parameters μ,ε,γ,δ_1, and α increase, while keeping other parameters constant, the effective reproduction number R_ev decreases. This implies the parameters decrease the endemicity of the infection as they have negative indices. Analytical results were numerically verified by the Differential Transformation Method (DTM) and quantitative views of the model equations were showcased. We established that as contact rate (β) increases, the effective reproduction number R_ev increases, as the effectiveness of drug usage increases, the R_ev decreases and as the quarantined individual decreases, the R_ev decreases. The results of the simulations showed that the infected individual increases when the susceptible person approaches zero, also the vaccination individual increases when the infected individual decreases and simultaneously increases the recovery individual.

Keywords: disease-free equilibrium, effective reproduction number, endemicity, Newcastle disease model, numerical, Sensitivity analysis

Procedia PDF Downloads 42
975 The Potential of On-Demand Shuttle Services to Reduce Private Car Use

Authors: B. Mack, K. Tampe-Mai, E. Diesch

Abstract:

Findings of an ongoing discrete choice study of future transport mode choice will be presented. Many urban centers face the triple challenge of having to cope with ever increasing traffic congestion, environmental pollution, and greenhouse gas emission brought about by private car use. In principle, private car use may be diminished by extending public transport systems like bus lines, trams, tubes, and trains. However, there are limits to increasing the (perceived) spatial and temporal flexibility and reducing peak-time crowding of classical public transport systems. An emerging new type of system, publicly or privately operated on-demand shuttle bus services, seem suitable to ameliorate the situation. A fleet of on-demand shuttle busses operates without fixed stops and schedules. It may be deployed efficiently in that each bus picks up passengers whose itineraries may be combined into an optimized route. Crowding may be minimized by limiting the number of seats and the inter-seat distance for each bus. The study is conducted as a discrete choice experiment. The choice between private car, public transport, and shuttle service is registered as a function of several push and pull factors (financial costs, travel time, walking distances, mobility tax/congestion charge, and waiting time/parking space search time). After the completion of the discrete choice items, the study participant is asked to rate the three modes of transport with regard to the pull factors of comfort, safety, privacy, and opportunity to engage in activities like reading or surfing the internet. These ratings are entered as additional predictors into the discrete choice experiment regression model. The study is conducted in the region of Stuttgart in southern Germany. N=1000 participants are being recruited. Participants are between 18 and 69 years of age, hold a driver’s license, and live in the city or the surrounding region of Stuttgart. In the discrete choice experiment, participants are asked to assume they lived within the Stuttgart region, but outside of the city, and were planning the journey from their apartment to their place of work, training, or education during the peak traffic time in the morning. Then, for each item of the discrete choice experiment, they are asked to choose between the transport modes of private car, public transport, and on-demand shuttle in the light of particular values of the push and pull factors studied. The study will provide valuable information on the potential of switching from private car use to the use of on-demand shuttles, but also on the less desirable potential of switching from public transport to on-demand shuttle services. Furthermore, information will be provided on the modulation of these switching potentials by pull and push factors.

Keywords: determinants of travel mode choice, on-demand shuttle services, private car use, public transport

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974 Design an Assessment Model of Research and Development Capabilities with the New Product Development Approach: A Case Study of Iran Khodro Company

Authors: Hamid Hanifi, Adel Azar, Alireza Booshehri

Abstract:

In order to know about the capability level of R & D units in automotive industry, it is essential that organizations always compare themselves with standard level and higher than themselves so that to be improved continuously. In this research, with respect to the importance of this issue, we have tried to present an assessment model for R & D capabilities having reviewed on new products development in automotive industry of Iran. Iran Khodro Company was selected for the case study. To this purpose, first, having a review on the literature, about 200 indicators effective in R & D capabilities and new products development were extracted. Then, of these numbers, 29 indicators which were more important were selected by industry and academia experts and the questionnaire was distributed among statistical population. Statistical population was consisted of 410 individuals in Iran Khodro Company. We used the 410 questionnaires for exploratory factor analysis and then used the data of 308 questionnaires from the same population randomly for confirmatory factor analysis. The results of exploratory factor analysis led to categorization of dimensions in 9 secondary dimensions. Naming the dimensions was done according to a literature review and the professors’ opinion. Using structural equation modeling and AMOS software, confirmatory factor analysis was conducted and ultimate model with 9 secondary dimensions was confirmed. Meanwhile, 9 secondary dimensions of this research are as follows: 1) Research and design capability, 2) Customer and market capability, 3) Technology capability, 4) Financial resources capability, 5) Organizational chart, 6) Intellectual capital capability, 7) NPD process capability, 8) Managerial capability and 9) Strategy capability.

Keywords: research and development, new products development, structural equations, exploratory factor analysis, confirmatory factor analysis

Procedia PDF Downloads 332
973 Modelling of Air-Cooled Adiabatic Membrane-Based Absorber for Absorption Chillers Using Low Temperature Solar Heat

Authors: M. Venegas, M. De Vega, N. García-Hernando

Abstract:

Absorption cooling chillers have received growing attention over the past few decades as they allow the use of low-grade heat to produce the cooling effect. The combination of this technology with solar thermal energy in the summer period can reduce the electricity consumption peak due to air-conditioning. One of the main components, the absorber, is designed for simultaneous heat and mass transfer. Usually, shell and tubes heat exchangers are used, which are large and heavy. Cooling water from a cooling tower is conventionally used to extract the heat released during the absorption and condensation processes. These are clear inconvenient for the generalization of the absorption technology use, limiting its benefits in the contribution to the reduction in CO2 emissions, particularly for the H2O-LiBr solution which can work with low heat temperature sources as provided by solar panels. In the present work a promising new technology is under study, consisting in the use of membrane contactors in adiabatic microchannel mass exchangers. The configuration here proposed consists in one or several modules (depending on the cooling capacity of the chiller) that contain two vapour channels, separated from the solution by adjacent microporous membranes. The solution is confined in rectangular microchannels. A plastic or synthetic wall separates the solution channels between them. The solution entering the absorber is previously subcooled using ambient air. In this way, the need for a cooling tower is avoided. A model of the configuration proposed is developed based on mass and energy balances and some correlations were selected to predict the heat and mass transfer coefficients. The concentration and temperatures along the channels cannot be explicitly determined from the set of equations obtained. For this reason, the equations were implemented in a computer code using Engineering Equation Solver software, EES™. With the aim of minimizing the absorber volume to reduce the size of absorption cooling chillers, the ratio between the cooling power of the chiller and the absorber volume (R) is calculated. Its variation is shown along the solution channels, allowing its optimization for selected operating conditions. For the case considered the solution channel length is recommended to be lower than 3 cm. Maximum values of R obtained in this work are higher than the ones found in optimized horizontal falling film absorbers using the same solution. Results obtained also show the variation of R and the chiller efficiency (COP) for different ambient temperatures and desorption temperatures typically obtained using flat plate solar collectors. The configuration proposed of adiabatic membrane-based absorber using ambient air to subcool the solution is a good technology to reduce the size of the absorption chillers, allowing the use of low temperature solar heat and avoiding the need for cooling towers.

Keywords: adiabatic absorption, air-cooled, membrane, solar thermal energy

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972 Consequences of Corruption on Tunisian Small and Medium Enterprises' Exports

Authors: Moujib Bahri, Ouafa Sakka, Kallel Rahim

Abstract:

This study builds on the literature about the effects of corruption on economic growth at the firm level, which analyzes how the payment of bribes affect organizational performance. Traditionally, the literature distinguishes two points of view regarding the impact of corruption: grease view and sand view. The grease view is based on the idea that corruption can compensate for the negative effect of red tape on firms’ activities such as innovation and exports. Therefore, some firms will be motivated to pay some additional money to officials in order to reduce the delay related to bureaucratic procedures. On the contrary, the second point of view considers that corruption sands the wheels of the economy and distorts resource allocation because it increases agency and transaction costs and reduces the returns on the investment. We have tested the effect of corruption on innovation and export activities on a sample of 537 Tunisian manufacturing small and medium enterprises (SMEs) using structural equation modeling and path analysis. Tunisia has undergone a revolution in 2010 and since then, the country is experiencing a political instability and economic hardships. Our results do not support the greasing hypothesis suggesting that corruption can reduce the negative effect of bureaucratic delays and the hard access of companies to public services related to exports. Instead, our results support the sanding hypothesis according to which corruption hinders SMEs’ exports through its negative influence on innovation. Furthermore, our results show that the interaction between excessive bureaucratic red tape and corruption has a negative effect on exports. However, the interaction between political instability and corruption increases exports.

Keywords: corruption, exports, SMEs, economic conditions

Procedia PDF Downloads 170
971 Conventional and Hybrid Network Energy Systems Optimization for Canadian Community

Authors: Mohamed Ghorab

Abstract:

Local generated and distributed system for thermal and electrical energy is sighted in the near future to reduce transmission losses instead of the centralized system. Distributed Energy Resources (DER) is designed at different sizes (small and medium) and it is incorporated in energy distribution between the hubs. The energy generated from each technology at each hub should meet the local energy demands. Economic and environmental enhancement can be achieved when there are interaction and energy exchange between the hubs. Network energy system and CO2 optimization between different six hubs presented Canadian community level are investigated in this study. Three different scenarios of technology systems are studied to meet both thermal and electrical demand loads for the six hubs. The conventional system is used as the first technology system and a reference case study. The conventional system includes boiler to provide the thermal energy, but the electrical energy is imported from the utility grid. The second technology system includes combined heat and power (CHP) system to meet the thermal demand loads and part of the electrical demand load. The third scenario has integration systems of CHP and Organic Rankine Cycle (ORC) where the thermal waste energy from the CHP system is used by ORC to generate electricity. General Algebraic Modeling System (GAMS) is used to model DER system optimization based on energy economics and CO2 emission analyses. The results are compared with the conventional energy system. The results show that scenarios 2 and 3 provide an annual total cost saving of 21.3% and 32.3 %, respectively compared to the conventional system (scenario 1). Additionally, Scenario 3 (CHP & ORC systems) provides 32.5% saving in CO2 emission compared to conventional system subsequent case 2 (CHP system) with a value of 9.3%.  

Keywords: distributed energy resources, network energy system, optimization, microgeneration system

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970 Integrated Modeling of Transformation of Electricity and Transportation Sectors: A Case Study of Australia

Authors: T. Aboumahboub, R. Brecha, H. B. Shrestha, U. F. Hutfilter, A. Geiges, W. Hare, M. Schaeffer, L. Welder, M. Gidden

Abstract:

The proposed stringent mitigation targets require an immediate start for a drastic transformation of the whole energy system. The current Australian energy system is mainly centralized and fossil fuel-based in most states with coal and gas-fired plants dominating the total produced electricity over the recent past. On the other hand, the country is characterized by a huge, untapped renewable potential, where wind and solar energy could play a key role in the decarbonization of the Australia’s future energy system. However, integrating high shares of such variable renewable energy sources (VRES) challenges the power system considerably due to their temporal fluctuations and geographical dispersion. This raises the concerns about flexibility gap in the system to ensure the security of supply with increasing shares of such intermittent sources. One main flexibility dimension to facilitate system integration of high shares of VRES is to increase the cross-sectoral integration through coupling of electricity to other energy sectors alongside the decarbonization of the power sector and reinforcement of the transmission grid. This paper applies a multi-sectoral energy system optimization model for Australia. We investigate the cost-optimal configuration of a renewable-based Australian energy system and its transformation pathway in line with the ambitious range of proposed climate change mitigation targets. We particularly analyse the implications of linking the electricity and transport sectors in a prospective, highly renewable Australian energy system.

Keywords: decarbonization, energy system modelling, renewable energy, sector coupling

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969 Relation Between Marital Adjustment and Parenting: The Moderating Effect of Children´s Temperament

Authors: Ester Ato, Maria Angeles Fernández-Vilar, Maria Dolores Galián

Abstract:

The aim of this work was to analyze the relation between children´s effortful control, marital adjustment and parenting practices in a sample of 345 Spanish children aged between 6 and 8 years. Traditionally, the literature confirms that a higher level of marital conflict has been associated with less effective and less positive parenting, but there are few studies that include the effect that children´s effortful control exert to this relation. To measure marital adjustment, parenting practices and children’s temperament, parents were given the Marital Adjustment Test (MAT), the Spanish version of the PCRI (Parent-Child Relationship Inventory), and the TMCQ (Temperament in Middle Childhood Questionnaire). The results confirmed that higher marital satisfaction predicted more positive parenting practices, whereas lower marital adjustment scores predicted less parenting support and control. Using a statistical modeling approach, we tested a moderation model that revealed the moderating role of effortful control in the relation between marital adjustment and parenting. Concretely, higher marital satisfaction predicts higher parenting communication and involvement, but only in children with low levels of effortful control. Therefore, a difficult temperament interferes in a less negative way in the family system when parents are satisfied and united. And a better self-regulated child predicts more effective parenting practice regardless of the parents´ marital satisfaction. The clinical implications of the present findings should be considered. Specifically, difficult children must be detected and evaluated in community settings, such as school or community programs, in order to take into account the marital adjustment and parenting practices of their parents, and to be able to design adequate family interventions and prevent future pathologizing patterns.

Keywords: effortful control, marital adjustment, parenting, moderation

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968 Examining the Predicting Effect of Mindfulness on Psychological Well-Being among Undergraduate Students

Authors: Piyanee Klainin-Yobas, Debbie Ramirez, Zenaida Fernandez, Jenneth Sarmiento, Wareerat Thanoi, Jeanette Ignacio, Ying Lau

Abstract:

In many countries, university students experience various stressors that may negatively affect their psychological well-being (PWB). Hence, they are at risk for physical and mental problems. This research aimed to examine the predicting effects of mindfulness, self-efficacy, and social support on psychological well-being among undergraduate students. A non-experimental research was conducted at a university in the Philippines. All students enrolled in undergraduate programs were eligible for this study unless they had chronic medical or mental health problems. Power analysis was used to calculate an adequate sample size and a convenience sampling of 630 was recruited. Data were collected through online self-reported questionnaires from year 2013 to 2015. All self-reported scales used in this study had sound psychometric properties. Descriptive statistics, correlational analyses, and structural equation modeling were performed to analyze the research data. Results showed that the participants were mostly Filipino, female, Christian, and in Schools of Nursing. Mindfulness, self-efficacy, support from family, support from friends, and support from significant others were significant predictors of psychological well-being. Mindfulness was the strongest predictor of positive psychological well-being whereas self-efficacy was the strongest predictor of negative psychological well-being. In conclusion, findings from this study add knowledge to the existing literature regarding the predictors of psychological well-being. Psychosocial interventions, with the focus on strengthening mindfulness and self-efficacy, could be delivered to undergraduate students to help them enhance psychological well-being. More studies can be undertaken to test the interventions and multi-centered research can be conducted to enhance generalizability of research findings.

Keywords: mindfulness, self-efficacy, social support, psychological wellbeing

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967 The Highly Dispersed WO3-x Photocatalyst over the Confinement Effect of Mesoporous SBA-15 Molecular Sieves for Photocatalytic Nitrogen Reduction

Authors: Xiaoling Ren, Guidong Yang

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As one of the largest industrial synthetic chemicals in the world, ammonia has the advantages of high energy density, easy liquefaction, and easy transportation, which is widely used in agriculture, chemical industry, energy storage, and other fields. The industrial Haber-Bosch method process for ammonia synthesis is generally conducted under severe conditions. It is essential to develop a green, sustainable strategy for ammonia production to meet the growing demand. In this direction, photocatalytic nitrogen reduction has huge advantages over the traditional, well-established Haber-Bosch process, such as the utilization of natural sun light as the energy source and significantly lower pressure and temperature to affect the reaction process. However, the high activation energy of nitrogen and the low efficiency of photo-generated electron-hole separation in the photocatalyst result in low ammonia production yield. Many researchers focus on improving the catalyst. In addition to modifying the catalyst, improving the dispersion of the catalyst and making full use of active sites are also means to improve the overall catalytic activity. Few studies have been carried out on this, which is the aim of this work. In this work, by making full use of the nitrogen activation ability of WO3-x with defective sites, small size WO3-x photocatalyst with high dispersibility was constructed, while the growth of WO3-x was restricted by using a high specific surface area mesoporous SBA-15 molecular sieve with the regular pore structure as a template. The morphology of pure SBA-15 and WO3-x/SBA-15 was characterized byscanning electron microscopy (SEM). Compared with pure SBA-15, some small particles can be found in the WO3-x/SBA-15 material, which means that WO3-x grows into small particles under the limitation of SBA-15, which is conducive to the exposure of catalytically active sites. To elucidate the chemical nature of the material, the X-ray diffraction (XRD) analysis was conducted. The observed diffraction pattern inWO3-xis in good agreement with that of the JCPDS file no.71-2450. Compared with WO3-x, no new peaks appeared in WO3-x/SBA-15.It can be concluded that WO3-x/SBA-15 was synthesized successfully. In order to provide more active sites, the mass content of WO3-x was optimized. Then the photocatalytic nitrogen reduction performances of above samples were performed with methanol as a hole scavenger. The results show that the overall ammonia production performance of WO3-x/SBA-15 is improved than pure bulk WO3-x. The above results prove that making full use of active sites is also a means to improve overall catalytic activity.This work provides material basis for the design of high-efficiency photocatalytic nitrogen reduction catalysts.

Keywords: ammonia, photocatalytic, nitrogen reduction, WO3-x, high dispersibility

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966 Applicability of Polyisobutylene-Based Polyurethane Structures in Biomedical Disciplines: Some Calcification and Protein Adsorption Studies

Authors: Nihan Nugay, Nur Cicek Kekec, Kalman Toth, Turgut Nugay, Joseph P. Kennedy

Abstract:

In recent years, polyurethane structures are paving the way for elastomer usage in biology, human medicine, and biomedical application areas. Polyurethanes having a combination of high oxidative and hydrolytic stability and excellent mechanical properties are focused due to enhancing the usage of PUs especially for implantable medical device application such as cardiac-assist. Currently, unique polyurethanes consisting of polyisobutylenes as soft segments and conventional hard segments, named as PIB-based PUs, are developed with precise NCO/OH stoichiometry (∽1.05) for obtaining PIB-based PUs with enhanced properties (i.e., tensile stress increased from ∽11 to ∽26 MPa and elongation from ∽350 to ∽500%). Static and dynamic mechanical properties were optimized by examining stress-strain graphs, self-organization and crystallinity (XRD) traces, rheological (DMA, creep) profiles and thermal (TGA, DSC) responses. Annealing procedure was applied for PIB-based PUs. Annealed PIB-based PU shows ∽26 MPa tensile strength, ∽500% elongation, and ∽77 Microshore hardness with excellent hydrolytic and oxidative stability. The surface characters of them were examined with AFM and contact angle measurements. Annealed PIB-based PU exhibits the higher segregation of individual segments and surface hydrophobicity thus annealing significantly enhances hydrolytic and oxidative stability by shielding carbamate bonds by inert PIB chains. According to improved surface and microstructure characters, greater efforts are focused on analyzing protein adsorption and calcification profiles. In biomedical applications especially for cardiological implantations, protein adsorption inclination on polymeric heart valves is undesirable hence protein adsorption from blood serum is followed by platelet adhesion and subsequent thrombus formation. The protein adsorption character of PIB-based PU examines by applying Bradford assay in fibrinogen and bovine serum albumin solutions. Like protein adsorption, calcium deposition on heart valves is very harmful because vascular calcification has been proposed activation of osteogenic mechanism in the vascular wall, loss of inhibitory factors, enhance bone turnover and irregularities in mineral metabolism. The calcium deposition on films are characterized by incubating samples in simulated body fluid solution and examining SEM images and XPS profiles. PIB-based PUs are significantly more resistant to hydrolytic-oxidative degradation, protein adsorption and calcium deposition than ElastEonTM E2A, a commercially available PDMS-based PU, widely used for biomedical applications.

Keywords: biomedical application, calcification, polyisobutylene, polyurethane, protein adsorption

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965 Study on the Thermal Mixing of Steam and Coolant in the Hybrid Safety Injection Tank

Authors: Sung Uk Ryu, Byoung Gook Jeon, Sung-Jae Yi, Dong-Jin Euh

Abstract:

In such passive safety injection systems in the nuclear power plant as Core Makeup Tank (CMT) and Hybrid Safety Injection Tank, various thermal-hydraulic phenomena including the direct contact condensation of steam and the thermal stratification of coolant occur. These phenomena are also closely related to the performance of the system. Depending on the condensation rate of the steam injected to the tank, the injection of the coolant and pressure equalizing timings of the tank are decided. The steam injected to the tank from the upper nozzle penetrates the coolant and induces a direct contact condensation. In the present study, the direct contact condensation of steam and the thermal mixing between the steam and coolant were examined by using the Particle Image Velocimetry (PIV) technique. Especially, by altering the size of the nozzle from which the steam is injected, the influence of steam injection velocity on the thermal mixing with coolant and condensation shall be comprehended, while also investigating the influence of condensation on the pressure variation inside the tank. Even though the amounts of steam inserted were the same in three different nozzle size conditions, it was found that the velocity of pressure rise becomes lower as the steam injection area decreases. Also, as the steam injection area increases, the thickness of the zone within which the coolant’s temperature decreases. Thereby, the amount of steam condensed by the direct contact condensation also decreases. The results derived from the present study can be utilized for the detailed design of a passive safety injection system, as well as for modeling the direct contact condensation triggered by the steam jet’s penetration into the coolant.

Keywords: passive safety injection systems, steam penetration, direct contact condensation, particle image velocimetry

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964 Cycle-Oriented Building Components and Constructions Made from Paper Materials

Authors: Rebecca Bach, Evgenia Kanli, Nihat Kiziltoprak, Linda Hildebrand, Ulrich Knaack, Jens Schneider

Abstract:

The building industry has a high demand for resources and at the same time is responsible for a significant amount of waste created worldwide. Today's building components need to contribute to the protection of natural resources without creating waste. This is defined in the product development phase and impacts the product’s degree of being cycle-oriented. Paper-based materials show advantage due to their renewable origin and their ability to incorporate different functions. Besides the ecological aspects like renewable origin and recyclability the main advantages of paper materials are its light-weight but stiff structure, the optimized production processes and good insulation values. The main deficits from building technology’s perspective are the material's vulnerability to humidity and water as well as inflammability. On material level, those problems can be solved by coatings or through material modification. On construction level intelligent setup and layering of a building component can improve and also solve these issues. The target of the present work is to provide an overview of developed building components and construction typologies mainly made from paper materials. The research is structured in four parts: (1) functions and requirements, (2) preselection of paper-based materials, (3) development of building components and (4) evaluation. As part of the research methodology at first the needs of the building sector are analyzed with the aim to define the main areas of application and consequently the requirements. Various paper materials are tested in order to identify to what extent the requirements are satisfied and determine potential optimizations or modifications, also in combination with other construction materials. By making use of the material’s potentials and solving the deficits on material and on construction level, building components and construction typologies are developed. The evaluation and the calculation of the structural mechanics and structural principals will show that different construction typologies can be derived. Profiles like paper tubes can be used at best for skeleton constructions. Massive structures on the other hand can be formed by plate-shaped elements like solid board or honeycomb. For insulation purposes corrugated cardboard or cellulose flakes have the best properties, while layered solid board can be applied to prevent inner condensation. Enhancing these properties by material combinations for instance with mineral coatings functional constructions mainly out of paper materials were developed. In summary paper materials offer a huge variety of possible applications in the building sector. By these studies a general base of knowledge about how to build with paper was developed and is to be reinforced by further research.

Keywords: construction typologies, cycle-oriented construction, innovative building material, paper materials, renewable resources

Procedia PDF Downloads 273