Search results for: foreign exchange rate

Authors: Tunchanok Nitipan, Siriporn Jongpatiwut, Thirasak Rirksomboon, Boonyarach Kitiyanan, Tivaporn Apphakvan

Abstract:

In this study, the conversion of n-pentane to aromatics is investigated on HZSM-5 zeolites modified by Ga ion-exchange and silylation using tetraethyl orthosilicate (TEOS) via chemical liquid deposition (CLD). The effect of SiO2/Al2O3 ratios of HZSM-5 was also studied. Parameters in preparing catalysts i.e. TEOS loading and cycles of deposition were varied to obtain the optimal condition for enhancing p-xylene selectivity. The highest p-xylene selectivity 99.7% was achieved when the amount of TEOS was 20 vol.%.The catalysts were characterized by TPD, TPO, XRF, and BET. Results show that the conversion of n-pentane was influenced remarkably by the SiO2/Al2O3 ratios of HZSM-5. The highest p-xylene selectivity 99.7% was achieved when the amount of TEOS was 20 vol.%. And cycles of deposition greatly improves HZSM-5 shape-selectivity.

Keywords: Aromatization, Chemical Liquid Deposition (CLD), p-Xylene, ZSM-5 Zeolite

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Authors: A.A.Rohani, B.Hatami, L.Jokar, F.khorasheh, A.A.Safekordi

Abstract:

In industrial scale of Gas to Liquid (GTL) process in Fischer-Tropsch (FT) synthesis, a part of reactor outlet gases such as CO2 and CH4 as side reaction products, is usually recycled. In this study, the influence of CO2 and CH4 on the performance and selectivity of Co-Ru/Al2O3 catalyst is investigated by injection of these gases (0-20 vol. % of feed) to the feed stream. The effect of temperature and feed flow rate, are also inspected. The results show that low amounts of CO2 in the feed stream, doesn`t change the catalyst activity significantly but increasing the amount of CO2 (more than 10 vol. %) cause the CO conversion to decrease and the selectivity of heavy components to increase. Methane acts as an inert gas and doesn`t affect the catalyst performance. Increasing feed flow rate has negative effect on both CO conversion and heavy component selectivity. By raising the temperature, CO conversion will increase but there are more volatile components in the product. The effect of CO2 on the catalyst deactivation is also investigated carefully and a mechanism is suggested to explain the negative influence of CO2 on catalyst deactivation.

Keywords: Alumina, Carbon dioxide, Cobalt catalyst, Conversion, Fischer Tropsch, Selectivity

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Authors: S. Thongchai

Abstract:

Result of the study on knowledge management systems in businesses was shown that the most of these businesses provide internet accessibility for their employees in order to study new knowledge via internet, corporate website, electronic mail, and electronic learning system. These business organizations use information technology application for knowledge management because of convenience, time saving, ease of use, accuracy of information and knowledge usefulness. The result indicated prominent improvements for corporate knowledge management systems as the following; 1) administrations must support corporate knowledge management system 2) the goal of corporate knowledge management must be clear 3) corporate culture should facilitate the exchange and sharing of knowledge within the organization 4) cooperation of personnel of all levels must be obtained 5) information technology infrastructure must be provided 6) they must develop the system regularly and constantly. 

Keywords: Business organizations, information technology application, knowledge management systems, and prominent improvements.

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Authors: Hadeer R. M. Tawfik, Rania A. K. Birry, Amani A. Saad

Abstract:

Eyes are considered to be the most sensitive and important organ for human being. Thus, any eye disorder will affect the patient in all aspects of life. Cataract is one of those eye disorders that lead to blindness if not treated correctly and quickly. This paper demonstrates a model for automatic detection, classification, and grading of cataracts based on image processing techniques and artificial intelligence. The proposed system is developed to ease the cataract diagnosis process for both ophthalmologists and patients. The wavelet transform combined with 2D Log Gabor Wavelet transform was used as feature extraction techniques for a dataset of 120 eye images followed by a classification process that classified the image set into three classes; normal, early, and advanced stage. A comparison between the two used classifiers, the support vector machine SVM and the artificial neural network ANN were done for the same dataset of 120 eye images. It was concluded that SVM gave better results than ANN. SVM success rate result was 96.8% accuracy where ANN success rate result was 92.3% accuracy.

Keywords: Cataract, classification, detection, feature extraction, grading, log-gabor, neural networks, support vector machines, wavelet.

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Authors: Venkata Ravi Kumar Veluru, Tej Kumar Karki

Abstract:

Indian traditional neighbourhoods are socially active and sometimes intrusive communities, which are losing their qualities due to Western influences, undermining the traditional Indian values by blind adaption of neighbourhood concepts since the western scale is not suitable to the Indian context. The main aim is to understand the qualities of Indian traditional neighbourhoods by evaluating a traditional neighbourhood of Jaipur, and comparing it with the modern planned neighbourhood of Chandigarh, (designed by a foreign planner, in the neighbourhood concept of the Western world), to find out the special qualities of traditional Indian neighbourhoods as compared to Western concepts based on social spaces, using methods such as physical observation of selected neighbourhoods and residents structured perception survey. A combined analysis found that social spaces are abundantly available in traditional neighbourhoods which are missing in modern neighbourhoods. The quality of traditional neighbourhoods is interactions that aim toward the formation of social capital. The qualities of traditional neighbourhoods have to be considered while designing new neighbourhoods in India.

Keywords: Indian Neighbourhoods, modern neighbourhoods, neighbourhood planning, social spaces, traditional neighbourhoods.

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Authors: A. Pashayev, D. Askerov, R. Sadiqov, A. Samedov, C. Ardil

Abstract:

In contrast to existing methods which do not take into account multiconnectivity in a broad sense of this term, we develop mathematical models and highly effective combination (BIEM and FDM) numerical methods of calculation of stationary and quasi-stationary temperature field of a profile part of a blade with convective cooling (from the point of view of realization on PC). The theoretical substantiation of these methods is proved by appropriate theorems. For it, converging quadrature processes have been developed and the estimations of errors in the terms of A.Ziqmound continuity modules have been received. For visualization of profiles are used: the method of the least squares with automatic conjecture, device spline, smooth replenishment and neural nets. Boundary conditions of heat exchange are determined from the solution of the corresponding integral equations and empirical relationships. The reliability of designed methods is proved by calculation and experimental investigations heat and hydraulic characteristics of the gas turbine first stage nozzle blade.

Keywords: Gas turbine, cooled blade, nozzle blade, temperature field.

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Authors: M. Izvercianu, L. Ivascu

Abstract:

This paper presents an innovative computer system that contributes to sustainable development of the enterprise. The research refers to a rethinking of traditional systems of collaboration and risk assessment, present in any organization, leading to a sustainable enterprise. This concept integrates emerging tools that allow the implementation and exploitation of the collective intelligence of the enterprise, allowing the exchange of contextual, agile and simplified information, and collaboration with networks of customers and partners in an environment where risks are controlled. Risk assessment is done in a systemic way: the enterprise as the system compared to the contained departments and the enterprise as a subsystem compared to: families of international standards and sustainability-s responsibilities. The enterprise, in this systemic vision, responds to the requirements that any existing system to operate continuously in an indefinite future without reaching key resource depletion. The research is done by integrating collaborative science, engineering, management, psychology, obtaining thus a cornerstone of sustainable development of the enterprise.

Keywords: Enterprise 2.0, ISO, Risk management, Sustainable development

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Authors: Anna Romanova, Mojtaba Mahmoodian, Upul Chandrasekara, Morteza A. Alani

Abstract:

Corrosion of concrete sewer pipes induced by sulphuric acid attack is a recognised problem worldwide, which is not only an attribute of countries with hot climate conditions as thought before. The significance of this problem is by far only realised when the pipe collapses causing surface flooding and other severe consequences. To change the existing post-reactive attitude of managing companies, easy to use and robust models are required to be developed which currently lack reliable data to be correctly calibrated. This paper focuses on laboratory experiments of establishing concrete pipe corrosion rate by submerging samples in to 0.5pH sulphuric acid solution for 56 days under 10ºC, 20ºC and 30ºC temperature regimes. The result showed that at very early stage of the corrosion process the samples gained overall mass, at 30ºC the corrosion progressed quicker than for other temperature regimes, however with time the corrosion level for 10ºC and 20ºC regimes tended towards those at 30ºC. Overall, at these conditions the corrosion rates of 10 mm/year, 13,5 mm/year and 17 mm/year were observed.

Keywords: Sewer pipes, concrete corrosion, sulphuric acid, concrete coupons, corrosion rate.

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Authors: Ismail Gerzeli, Cemal Baykara, Osman Akin Kutlar

Abstract:

Skip cycle is a working strategy for spark ignition engines, which allows changing the effective stroke of an engine through skipping some of the four stroke cycles. This study proposes a new mechanism to achieve the desired skip-cycle strategy for internal combustion engines. The air and fuel leakage, which occurs through the gas exchange, negatively affects the efficiency of the engine at high speeds and loads. An absolute sealing is assured by direct use of poppet valves, which are kept in fully closed position during the skipped mode. All the components of the mechanism were designed according to the real dimensions of the Anadolu Motor's gasoline engine and modeled in 3D by means of CAD software. As the mechanism operates in two modes, two dynamically equivalent models are established to obtain the force and strength analysis for critical components.

Keywords: Dynamic Model, Mechanical Design, Skip Cycle System (SCS), Valve Disabling Mechanism

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Authors: Umpawan Satitthai, Apanee Luengnaruemitchai, Erdogan Gulari

Abstract:

In this study, oxidative steam reforming of methanol (OSRM) over a Au/CeO2–Fe2O3 catalyst prepared by a depositionprecipitation (DP) method was studied to produce hydrogen in order to feed a Proton Exchange Membrane Fuel Cell (PEMFC). The support (CeO2, Fe2O3, and CeO2–Fe2O3) were prepared by precipitation and co-precipitation methods. The impact of the support composition on the catalytic performance was studied by varying the Ce/(Ce+Fe) atomic ratio, it was found that the 1%Au/CF(0.25) calcined at 300 °C exhibited the highest catalytic activity in the whole temperature studied. In addition, the effect of Au content was investigated and 3%Au/CF(0.25) exhibited the highest activity under the optimum condition in the temperature range of 200 °C to 400 °C. The catalysts were characterized by various techniques: XRD, TPR, XRF, and UV-vis.

Keywords: CeO2, Fe2O3, Gold catalyst, Hydrogen production, Methanol, Oxidative steam reforming.

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Authors: Yogita, Durga Toshniwal

Abstract:

Outlier detection in streaming data is very challenging because streaming data cannot be scanned multiple times and also new concepts may keep evolving. Irrelevant attributes can be termed as noisy attributes and such attributes further magnify the challenge of working with data streams. In this paper, we propose an unsupervised outlier detection scheme for streaming data. This scheme is based on clustering as clustering is an unsupervised data mining task and it does not require labeled data, both density based and partitioning clustering are combined for outlier detection. In this scheme partitioning clustering is also used to assign weights to attributes depending upon their respective relevance and weights are adaptive. Weighted attributes are helpful to reduce or remove the effect of noisy attributes. Keeping in view the challenges of streaming data, the proposed scheme is incremental and adaptive to concept evolution. Experimental results on synthetic and real world data sets show that our proposed approach outperforms other existing approach (CORM) in terms of outlier detection rate, false alarm rate, and increasing percentages of outliers.

Keywords: Concept Evolution, Irrelevant Attributes, Streaming Data, Unsupervised Outlier Detection.

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Authors: A. Alzeyadi, E. Loffill, R. Alkhaddar

Abstract:

Continuous upflow filters can combine the nutrient (nitrogen and phosphate) and suspended solid removal in one unit process. The contaminant removal could be achieved chemically or biologically; in both processes the filter removal efficiency depends on the interaction between the packed filter media and the influent. In this paper a residence time distribution (RTD) study was carried out to understand and compare the transfer behaviour of contaminants through a selected filter media packed in a laboratory-scale continuous up flow filter; the selected filter media are limestone and white dolomite. The experimental work was conducted by injecting a tracer (red drain dye tracer –RDD) into the filtration system and then measuring the tracer concentration at the outflow as a function of time; the tracer injection was applied at hydraulic loading rates (HLRs) (3.8 to 15.2 m h-1). The results were analysed according to the cumulative distribution function F(t) to estimate the residence time of the tracer molecules inside the filter media. The mean residence time (MRT) and variance σ2 are two moments of RTD that were calculated to compare the RTD characteristics of limestone with white dolomite. The results showed that the exit-age distribution of the tracer looks better at HLRs (3.8 to 7.6 m h-1) and (3.8 m h-1) for limestone and white dolomite respectively. At these HLRs the cumulative distribution function F(t) revealed that the residence time of the tracer inside the limestone was longer than in the white dolomite; whereas all the tracer took 8 minutes to leave the white dolomite at 3.8 m h-1. On the other hand, the same amount of the tracer took 10 minutes to leave the limestone at the same HLR. In conclusion, the determination of the optimal level of hydraulic loading rate, which achieved the better influent distribution over the filtration system, helps to identify the applicability of the material as filter media. Further work will be applied to examine the efficiency of the limestone and white dolomite for phosphate removal by pumping a phosphate solution into the filter at HLRs (3.8 to 7.6 m h-1).

Keywords: Filter media, hydraulic loading rate, residence time distribution, tracer.

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Authors: Martina Drdlová, Michal Frank, Jaroslav Buchar, Josef Krátký

Abstract:

The main aim of the presented experiments is to improve behaviour of sandwich structures under dynamic loading, such as crash or explosion. Several cellular materials are widely used as core of the sandwich structures and their properties influence the response of the entire element under impact load. To optimize their performance requires the characterisation of the core material behaviour at high strain rates and identification of the underlying mechanism. This work presents the study of high strain-rate characteristics of a specific porous lightweight blast energy absorbing foam using a Split Hopkinson Pressure Bar (SHPB) technique adapted to perform tests on low strength materials. Two different velocities, 15 and 30 m.s-1 were used to determine the strain sensitivity of the material. Foams were designed using two types of porous lightweight spherical raw materials with diameters of 30- 100 *m, combined with polymer matrix. Cylindrical specimens with diameter of 15 mm and length of 7 mm were prepared and loaded using a Split Hopkinson Pressure Bar apparatus to assess the relation between the composition of the material and its shock wave attenuation capacity.

Keywords: Blast, foam, microsphere, resin.

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Authors: Yassine Meraihi, Dalila Acheli, Rabah Meraihi

Abstract:

Vehicular Ad hoc Network (VANET) is a special case of Mobile Ad hoc Network (MANET) used to establish communications and exchange information among nearby vehicles and between vehicles and nearby fixed infrastructure. VANET is seen as a promising technology used to provide safety, efficiency, assistance and comfort to the road users. Routing is an important issue in Vehicular Ad Hoc Network to find and maintain communication between vehicles due to the highly dynamic topology, frequently disconnected network and mobility constraints.

This paper evaluates the performance of two most popular proactive routing protocols OLSR and DSDV in real city traffic scenario on the basis of three metrics namely Packet delivery ratio, throughput and average end to end delay by varying vehicles density and transmission range.

Keywords: DSDV, OLSR, Quality of service, Routing protocols, VANET.

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Authors: Abdallah S. Abdallah, A. Lynn Abbott, Mohamad Abou El-Nasr

Abstract:

This paper presents a new technique for detection of human faces within color images. The approach relies on image segmentation based on skin color, features extracted from the two-dimensional discrete cosine transform (DCT), and self-organizing maps (SOM). After candidate skin regions are extracted, feature vectors are constructed using DCT coefficients computed from those regions. A supervised SOM training session is used to cluster feature vectors into groups, and to assign “face" or “non-face" labels to those clusters. Evaluation was performed using a new image database of 286 images, containing 1027 faces. After training, our detection technique achieved a detection rate of 77.94% during subsequent tests, with a false positive rate of 5.14%. To our knowledge, the proposed technique is the first to combine DCT-based feature extraction with a SOM for detecting human faces within color images. It is also one of a few attempts to combine a feature-invariant approach, such as color-based skin segmentation, together with appearance-based face detection. The main advantage of the new technique is its low computational requirements, in terms of both processing speed and memory utilization.

Keywords: Face detection, skin color segmentation, self-organizingmap.

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Authors: A. Borji, M. Hamidi

Abstract:

A new method for color image segmentation using fuzzy logic is proposed in this paper. Our aim here is to automatically produce a fuzzy system for color classification and image segmentation with least number of rules and minimum error rate. Particle swarm optimization is a sub class of evolutionary algorithms that has been inspired from social behavior of fishes, bees, birds, etc, that live together in colonies. We use comprehensive learning particle swarm optimization (CLPSO) technique to find optimal fuzzy rules and membership functions because it discourages premature convergence. Here each particle of the swarm codes a set of fuzzy rules. During evolution, a population member tries to maximize a fitness criterion which is here high classification rate and small number of rules. Finally, particle with the highest fitness value is selected as the best set of fuzzy rules for image segmentation. Our results, using this method for soccer field image segmentation in Robocop contests shows 89% performance. Less computational load is needed when using this method compared with other methods like ANFIS, because it generates a smaller number of fuzzy rules. Large train dataset and its variety, makes the proposed method invariant to illumination noise

Keywords: Comprehensive learning Particle Swarmoptimization, fuzzy classification.

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Authors: Aleksandra Nocoń (Szunke)

Abstract:

The study is a review of the literature concerning the consequences of non-standard monetary policy, which are used by central banks during unconventional periods, threatening banking sector instability. In particular, the attention was paid to the effects of non-standard monetary policy tools for financial markets. However, the empirical evidence about their effects and real consequences for financial markets is still not final. The main aim of the study is to survey consequences of standard and non-standard monetary policy instruments, implemented during the global financial crisis in the United States, United Kingdom and euro area, with particular attention to the results for the stabilization of global financial markets. The study consists mainly of the empirical review, indicating the impact of the implementation of these tools for financial markets. The following research methods were used in the study: literature studies, including domestic and foreign literature, cause and effect analysis and statistical analysis.

Keywords: Asset purchase facility, consequences of monetary policy instruments, non-standard monetary policy, Quantitative Easing.

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Authors: Asfaw Gezae Daful

Abstract:

In the present study, two distinctly different approaches are followed for modeling of reactive distillation column, the equilibrium stage model and the nonequilibrium stage model. These models are simulated with a computer code developed in the present study using MATLAB programming. In the equilibrium stage models, the vapor and liquid phases are assumed to be in equilibrium and allowance is made for finite reaction rates, where as in the nonequilibrium stage models simultaneous mass transfer and reaction rates are considered. These simulated model results are validated from the experimental data reported in the literature. The simulated results of equilibrium and nonequilibrium models are compared for concentration, temperature and reaction rate profiles in a reactive distillation column for Methyl Tert Butyle Ether (MTBE) production. Both the models show similar trend for the concentration, temperature and reaction rate profiles but the nonequilibrium model predictions are higher and closer to the experimental values reported in the literature.

Keywords: Reactive Distillation, Equilibrium model, Nonequilibrium model, Methyl Tert-Butyl Ether

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Authors: T. Zergoug, S.H. Abaidia, A. Nedjar, M. Y. Mokeddem

Abstract:

Physical properties of uranium dinitride (UN2) were investigated in detail using first principle calculations based on density functional theory (DFT). To study the strong correlation effects due to 5f uranium valence electrons, the on-site coulomb interaction correction U via the Hubbard-like term (DFT+U) was employed. The UN2 structural, mechanical and thermodynamic properties were calculated within DFT and Various U of DFT+U approach. The Perdew–Burke–Ernzerhof (PBE.5.2) version of the generalized gradient approximation (GGA) is used to describe the exchange-correlation with the projector-augmented wave (PAW) pseudo potentials. A comparative study shows that results are improved by using the Hubbard formalism for a certain U value correction like the structural parameter. For some physical properties the variation versus Hubbard-U is strong like Young modulus but for others it is weakly noticeable such as bulk modulus. We noticed also that from U=7.5 eV, elastic results don’t agree with the cubic cell because of the C44 values which turn out to be negative.

Keywords: Ab initio, bulk modulus, DFT, DFT + U.

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Authors: R. Reka, R. S. D. Wahidabanu

Abstract:

The aim of this paper is to propose a novel technique to guarantee Quality of Service (QoS) in a highly dynamic environment. The MANET changes its topology dynamically as the nodes are moved frequently. This will cause link failure between mobile nodes. MANET cannot ensure reliability without delay. The relay node is selected based on achieving QoS in previous transmission. It considers one more factor Connection Existence Period (CEP) to ensure reliability. CEP is to find out the period during that connection exists between the nodes. The node with highest CEP becomes a next relay node. The relay node is selected dynamically to avoid frequent failure. The bandwidth of each link changed dynamically based on service rate and request rate. This paper proposes Active bandwidth setting up algorithm to guarantee the QoS. The series of results obtained by using the Network Simulator (NS-2) demonstrate the viability of our proposed techniques.

Keywords: Bandwidth, Connection Existence Period (CEP), Mobile Adhoc Network (MANET), Quality of Service (QoS), Relay node.

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Authors: K. Anitha Sheela, J. Tarun Kumar

Abstract:

HSDPA is a new feature which is introduced in Release-5 specifications of the 3GPP WCDMA/UTRA standard to realize higher speed data rate together with lower round-trip times. Moreover, the HSDPA concept offers outstanding improvement of packet throughput and also significantly reduces the packet call transfer delay as compared to Release -99 DSCH. Till now the HSDPA system uses turbo coding which is the best coding technique to achieve the Shannon limit. However, the main drawbacks of turbo coding are high decoding complexity and high latency which makes it unsuitable for some applications like satellite communications, since the transmission distance itself introduces latency due to limited speed of light. Hence in this paper it is proposed to use LDPC coding in place of Turbo coding for HSDPA system which decreases the latency and decoding complexity. But LDPC coding increases the Encoding complexity. Though the complexity of transmitter increases at NodeB, the End user is at an advantage in terms of receiver complexity and Bit- error rate. In this paper LDPC Encoder is implemented using “sparse parity check matrix" H to generate a codeword at Encoder and “Belief Propagation algorithm "for LDPC decoding .Simulation results shows that in LDPC coding the BER suddenly drops as the number of iterations increase with a small increase in Eb/No. Which is not possible in Turbo coding. Also same BER was achieved using less number of iterations and hence the latency and receiver complexity has decreased for LDPC coding. HSDPA increases the downlink data rate within a cell to a theoretical maximum of 14Mbps, with 2Mbps on the uplink. The changes that HSDPA enables includes better quality, more reliable and more robust data services. In other words, while realistic data rates are only a few Mbps, the actual quality and number of users achieved will improve significantly.

Keywords: AMC, HSDPA, LDPC, WCDMA, 3GPP.

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Authors: А. Pashayev, C. Ardil, D. Askerov, R. Sadiqov, A. Samedov

Abstract:

In contrast to existing methods which do not take into account multiconnectivity in a broad sense of this term, we develop mathematical models and highly effective combination (BIEM and FDM) numerical methods of calculation of stationary and quasistationary temperature field of a profile part of a blade with convective cooling (from the point of view of realization on PC). The theoretical substantiation of these methods is proved by appropriate theorems. For it, converging quadrature processes have been developed and the estimations of errors in the terms of A.Ziqmound continuity modules have been received. For visualization of profiles are used: the method of the least squares with automatic conjecture, device spline, smooth replenishment and neural nets. Boundary conditions of heat exchange are determined from the solution of the corresponding integral equations and empirical relationships. The reliability of designed methods is proved by calculation and experimental investigations heat and hydraulic characteristics of the gas turbine first stage nozzle blade.

Keywords: Mathematical Modeling, Gas Turbine Blade Cooling, Neural Networks, BIEM and FDM.

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Authors: Chan-Sik Kim, Jong-Seong Kim, Se Won Lee, Hoo-Gon Choi

Abstract:

In rapidly changing market environment, firms are investing a lot of time and resources into new product development (NPD) projects to make profit and to obtain competitive advantage. However, failure rate of NPD projects is becoming high due to various internal and external risks which hinder successful NPD projects. To reduce the failure rate, it is critical that risks have to be managed effectively and efficiently through good strategy, and treated by optimal responses to minimize risk cost. Four strategies are adopted to handle the risks in this study. The optimal responses are characterized by high reduction of risk costs with high efficiency. This study suggests a framework to decide the optimal responses considering the core risks, risk costs, response efficiency and response costs for successful NPD projects. Both binary particles warm optimization (BPSO) and multi-objective particle swarm optimization (MOPSO) methods are mainly used in the framework. Although several limitations exist in use for real industries, the frame work shows good strength for handling the risks with highly scientific ways through an example.

Keywords: NPD projects, risk cost, strategy, optimal responses, Particle Swarm Optimization.

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Authors: S. Chikh, S. Boulifa

Abstract:

The present study addresses the problem of ammonia evaporation during filling of a vertical cylindrical tank and the influence of various external factors on the stability of storage by determining the conditions for minimum evaporation. Numerical simulation is carried out by solving the governing equations namely, continuity, momentum, energy, and diffusion of species. The effect of temperature of surrounding air, the filling speed of the reservoir and the temperature of the filling liquid ammonia on the evaporation rate is investigated. Results show that the temperature of the filling liquid has little effect on the liquid ammonia for a short period, which, in fact, is function of the filling speed. The evaporation rate along the free surface of the liquid is non-uniform. The inlet temperature affects the vapor ammonia temperature because of pressure increase. The temperature of the surrounding air affects the temperature of the vapor phase rather than the liquid phase. The maximum of evaporation is reached at the final step of filling. In order to minimize loss of ammonia vapors automatically causing losses in quantity of the liquid stored, it is suggested to ensure the proper insulation for the walls and roof of the reservoir and to increase the filling speed.

Keywords: Evaporation, liquid ammonia, storage tank, numerical simulation.

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Authors: Bakhtiar Ul Haq, R. Ahmed, A. Shaari, Mazmira Binti Mohamed, Nisar Ali

Abstract:

The capability of exploiting the electronic charge and spin properties simultaneously in a single material has made diluted magnetic semiconductors (DMS) remarkable in the field of spintronics. We report the designing of DMS based on zinc-blend ZnO doped with Cr impurity. The full potential linearized augmented plane wave plus local orbital FP-L(APW+lo) method in density functional theory (DFT) has been adapted to carry out these investigations. For treatment of exchange and correlation energy, generalized gradient approximations have been used. Introducing Cr atoms in the matrix of ZnO has induced strong magnetic moment with ferromagnetic ordering at stable ground state. Cr:ZnO was found to favor the short range magnetic interaction that reflect tendency of Cr clustering. The electronic structure of ZnO is strongly influenced in the presence of Cr impurity atoms where impurity bands appear in the band gap.

Keywords: ZnO, Density functional theory, Diluted magnetic semiconductors, Ferromagnetic materials, FP-L(APW+lo).

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Authors: Areej Azhar, Peter Duncan, David Edgar

Abstract:

Due to a high unemployment rate among local people and a high reliance on expatriate workers, the governments in the Gulf Co-operation Council (GCC) countries have been implementing programmes of localisation (replacing foreign workers with GCC nationals). These programmes have been successful in the public sector but much less so in the private sector. However, there are now insufficient jobs for locals in the public sector and the onus to provide employment has fallen on the private sector. This paper is concerned with a study, which is a work in progress (certain elements are complete but not the whole study), investigating the effective implementation of localisation policies in four- and five-star hotels in the Kingdom of Saudi Arabia (KSA) and the United Arab Emirates (UAE). The purpose of the paper is to identify the research gap, and to present the need for the research. Further, it will explain how this research was conducted. Studies of localisation in the GCC countries are under-represented in scholarly literature. Currently, the hotel sectors in KSA and UAE play an important part in the countries’ economies. However, the total proportion of Saudis working in the hotel sector in KSA is slightly under 8%, and in the UAE, the hotel sector remains highly reliant on expatriates. There is therefore a need for research on strategies to enhance the implementation of the localisation policies in general and in the hotel sector in particular. Further, despite the importance of the hotel sector to their economies, there remains a dearth of research into the implementation of localisation policies in this sector. Indeed, as far as the researchers are aware, there is no study examining localisation in the hotel sector in KSA, and few in the UAE. This represents a considerable research gap. Regarding how the research was carried out, a multiple case study strategy was used. The four- and five-star hotel sector in KSA is one of the cases, while the four- and five-star hotel sector in the UAE is the other case. Four- and five-star hotels in KSA and the UAE were chosen as these countries have the longest established localisation policies of all the GCC states and there are more hotels of these classifications in these countries than in any of the other Gulf countries. A literature review was carried out to underpin the research. The empirical data were gathered in three phases. In order to gain a pre-understanding of the issues pertaining to the research context, Phase I involved eight unstructured interviews with officials from the Saudi Commission for Tourism and Antiquities (three interviewees); the Saudi Human Resources Development Fund (one); the Abu Dhabi Tourism and Culture Authority (three); and the Abu Dhabi Development Fund (one).

In Phase II, a questionnaire was administered to 24 managers and 24 employees in four- and five-star hotels in each country to obtain their beliefs, attitudes, opinions, preferences and practices concerning localisation. Unstructured interviews were carried out in Phase III with six managers in each country in order to allow them to express opinions that may not have been explored in sufficient depth in the questionnaire. The interviews in Phases I and III were analysed using thematic analysis and SPSS will be used to analyse the questionnaire data. It is recommended that future research be undertaken on a larger scale, with a larger sample taken from all over KSA and the UAE rather than from only four cities (i.e., Riyadh and Jeddah in KSA and Abu Dhabi and Sharjah in the UAE), as was the case in this research.

Keywords: KSA, UAE, localisation, hotels, Human Resource Management.

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Authors: Reeta Devi, Hitender Kumar Tyagi, Dinesh Kumar

Abstract:

In present scenario, cardiovascular problems are growing challenge for researchers and physiologists. As heart disease have no geographic, gender or socioeconomic specific reasons; detecting cardiac irregularities at early stage followed by quick and correct treatment is very important. Electrocardiogram is the finest tool for continuous monitoring of heart activity. Heart rate variability (HRV) is used to measure naturally occurring oscillations between consecutive cardiac cycles. Analysis of this variability is carried out using time domain, frequency domain and non-linear parameters. This paper presents HRV analysis of the online dataset for normal sinus rhythm (taken as healthy subject) and sudden cardiac death (SCD subject) using all three methods computing values for parameters like standard deviation of node to node intervals (SDNN), square root of mean of the sequences of difference between adjacent RR intervals (RMSSD), mean of R to R intervals (mean RR) in time domain, very low-frequency (VLF), low-frequency (LF), high frequency (HF) and ratio of low to high frequency (LF/HF ratio) in frequency domain and Poincare plot for non linear analysis. To differentiate HRV of healthy subject from subject died with SCD, k –nearest neighbor (k-NN) classifier has been used because of its high accuracy. Results show highly reduced values for all stated parameters for SCD subjects as compared to healthy ones. As the dataset used for SCD patients is recording of their ECG signal one hour prior to their death, it is therefore, verified with an accuracy of 95% that proposed algorithm can identify mortality risk of a patient one hour before its death. The identification of a patient’s mortality risk at such an early stage may prevent him/her meeting sudden death if in-time and right treatment is given by the doctor.

Keywords: Early stage prediction, heart rate variability, linear and non linear analysis, sudden cardiac death.

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Authors: Maurizio Mastroianni, Lou Savoni, Paul Henshaw, Gary W. Rankin

Abstract:

The refueling of a transparent rectangular fuel tank fitted with a standard filler pipe and roll-over valve was experimentally studied. A fuel-conditioning cart, capable of handling fuels of different Reid vapor pressure at a constant temperature, was used to dispense fuel at the desired rate. The experimental protocol included transient recording of the tank and filler tube pressures while video recording the flow patterns in the filler tube and tank during the refueling process. This information was used to determine the effect of changes in the vent tube diameter, fuel-dispense flow rate and fuel Reid vapor pressure on the pressure-time characteristics and the occurrence of premature fuel filling shut-off and fuel spill-back. Pressure-time curves for the case of normal shut-off demonstrated the classic, three-phase characteristic noted in the literature. The variation of the maximum values of tank dome and filler tube pressures are analyzed in relation to the occurrence of premature shut-off.

Keywords: experimental study, fuel tank filling, premature shutoff, spill-back

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Authors: Jean François Chatelain, Imed Zaghbani, Joseph Monier

Abstract:

The machining of Carbon Fiber Reinforced Plastics has come to constitute a significant challenge for many fields of industry. The resulting surface finish of machined parts is of primary concern for several reasons, including contact quality and impact on the assembly. Therefore, the characterization and prediction of roughness based on machining parameters are crucial for costeffective operations. In this study, a PCD tool comprised of two straight flutes was used to trim 32-ply carbon fiber laminates in a bid to analyze the effects of the feed rate and the cutting speed on the surface roughness. The results show that while the speed has but a slight impact on the surface finish, the feed rate for its part affects it strongly. A detailed study was also conducted on the effect of fiber orientation on surface roughness, for quasi-isotropic laminates used in aerospace. The resulting roughness profiles for the four-ply orientation lay-up were compared, and it was found that fiber angle is a critical parameter relating to surface roughness. One of the four orientations studied led to very poor surface finishes, and characteristic roughness profiles were identified and found to only relate to the ply orientations of multilayer carbon fiber laminates.

Keywords: Roughness, Detouring, Composites, Aerospace

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Authors: Yu-Chuan Chang, Chen Shi-Kai

Abstract:

A water reuse system in wetland paddy was simulated to supply water for industrial in this paper. A two-tank model was employed to represent the return flow of the wetland paddy.Historical data were performed for parameter estimation and model verification. With parameters estimated from the data, the model was then used to simulate a reasonable return flow rate from the wetland paddy. The simulation results show that the return flow ratio was 11.56% in the first crop season and 35.66% in the second crop season individually; the difference may result from the heavy rainfall in the second crop season. Under the existent pond with surplus active capacity, the water reuse ratio was 17.14%, and the water supplementary ratio was 21.56%. However, the pattern of rainfall, the active capacity of the pond, and the rate of water treatment limit the volume of reuse water. Increasing the irrigation water, dredging the depth of pond before rainy season and enlarging the scale of module are help to develop water reuse system to support for the industrial water use around wetland paddy.

Keywords: Return flow, water reuse, wetland paddy, return flow ratio (RR), water reuse ratio (WRR), water supplementary ratio(WSR)

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