Search results for: internal tides

Authors: Merzak Laribi, Abdelmadjid Kasser

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Thermal spraying processes are widely used to produce coatings on original constructions as well as in repair and maintenance of long standing structures. A lot of efforts forwarding to develop thermal spray coatings technology have been focused on improving mechanical characteristics, minimizing residual stress level and reducing porosity of the coatings. The specific aim of this paper is to determine either residual stresses distribution or wear resistance of stainless steel coating thermally sprayed on a carbon steel substrate. Internal stresses determination was performed using an extensometric method in combination with a simultaneous progressive electrolytic polishing. The procedure consists of measuring micro-deformations using a bi-directional extensometric gauges glued on the substrate side of the materials. Very thin layers of the deposits are removed by electrochemical polishing across the sample surface. Micro-deformations are instantaneously measured, leading to residual stresses calculation after each removal. Wear resistance of the coating has been determined using a ball-on-plate tribometer. Friction coefficient is instantaneously measured during the tribological test. Attention was particularly focused on the influence of a post-annealing at 850 °C for one hour in vacuum either on the residual stresses distribution or on the wear resistance behavior under specific wear and lubrication conditions. The obtained results showed that the microstructure of the obtained arc sprayed stainless steel coating is classical. It is homogeneous and contains un-melted particles, metallic oxides and also pores and micro-cracks. The internal stresses are in compression in the coating. They are more or less scattered between -50 and -270 MPa on the surface and decreased more at the interface. The value at the surface of the substrate is about –700 MPa, partially due to the molten particles impact with the substrate. The post annealing has reduced the residual stresses in both coating and surface of the steel substrate so that the hole material becomes more relaxed. Friction coefficient has an average value of 0.3 and 0.4 respectively for non annealed and annealed specimen. It is rather oil lubrication which is really benefit so that friction coefficient is decreased to about 0.06.

Keywords: residual stresses, wear resistance, stainless steel, coating, thermal spraying, annealing, lubrication

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Authors: Ahmed G. Mahgoub, Dahlia H. Hafez, Mostafa A. Abu Kiefa

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The Cone Penetration Test (CPT) is a common in-situ test which generally investigates a much greater volume of soil more quickly than possible from sampling and laboratory tests. Therefore, it has the potential to realize both cost savings and assessment of soil properties rapidly and continuously. The principle objective of this paper is to demonstrate the feasibility and efficiency of using artificial neural networks (ANNs) to predict the soil angle of internal friction (Φ) and the soil modulus of elasticity (E) from CPT results considering the uncertainties and non-linearities of the soil. In addition, ANNs are used to study the influence of different parameters and recommend which parameters should be included as input parameters to improve the prediction. Neural networks discover relationships in the input data sets through the iterative presentation of the data and intrinsic mapping characteristics of neural topologies. General Regression Neural Network (GRNN) is one of the powerful neural network architectures which is utilized in this study. A large amount of field and experimental data including CPT results, plate load tests, direct shear box, grain size distribution and calculated data of overburden pressure was obtained from a large project in the United Arab Emirates. This data was used for the training and the validation of the neural network. A comparison was made between the obtained results from the ANN's approach, and some common traditional correlations that predict Φ and E from CPT results with respect to the actual results of the collected data. The results show that the ANN is a very powerful tool. Very good agreement was obtained between estimated results from ANN and actual measured results with comparison to other correlations available in the literature. The study recommends some easily available parameters that should be included in the estimation of the soil properties to improve the prediction models. It is shown that the use of friction ration in the estimation of Φ and the use of fines content in the estimation of E considerable improve the prediction models.

Keywords: angle of internal friction, cone penetrating test, general regression neural network, soil modulus of elasticity

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Authors: Fabian Nde Fon

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Decolonisation is one of the hottest topics in most African Universities; this is because many researchers focus on research that does not speak to their immediate community. This research looked at postgraduate research projects that can take students to the community to apply the knowledge that they have learned as an attempt to transform their community. In regards to this, an honours project was designed to try and provide a cheaper and continuous source of protein (egg) using amber-link layers and to investigate the potential of the project to promote postgraduate student development and entrepreneurship. Two ban layer production systems were created: (1) Production system one on a Hill (PS-I) and (2) Production system two in a valley, closer to a dam (PS-II) at Nqutshini, Gingindlovu, KwaZulu-Natal Province. Forty point-of-lay (18 weeks old) amber links were bought at Inverness Rearers and divided into PS-I (20), and PS-II (20), and each of the production systems was further divided into two groups of ten (PS-I-1 and PS-II-1 (partially supplemented) and PS-I-2 and PS-II-2 (supplemented with layer mash)) by a random selection. Birds' weights were balanced in each group to avoid bias. The two groups in each production system were caged separately (1.5x1.5m² for ten birds) and in close proximity. Partially supplemented birds received 0.6 kg of layer mash (60g/per bird/day) and kitchen leftovers daily, and supplemented birds were fed 1.2 kg of layer mash (120g/per bird/day). Egg collection was daily after feeding in the morning while was given ad libitium. The eggs were assessed for internal and external quality after weighing before recording. Egg production from fully supplemented birds (PS-I-2 and PS-II-2) was generally higher (P<0.05) than those of PS-I-1 and PS-II-1. The difference in production was only 6% in the valley while on the Hill, it was only 3%. However, some of the birds in the valley showed signs of respiratory infections, which was not observed with those on the Hill. There are no differences in the internal and external qualities of eggs (york colour and egg shell) determined. This implies that both systems were sustainable. It was suggested members in the community living at the valley or Hill can use these hardy layers as a cheaper source of protein and preferable to the partially supplemented systems because it is relatively cheaper. The smallholder farmers are still pursuing the project long after the students graduate; hence the benefit of the project is reciprocal for both the university and the community (entrepreneurship).

Keywords: animal nutrition, ban layer, production, postgraduate curricula, entrepreneurship

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Authors: A. A. Purohit, M. M. Vaidya, M. D. Kudale

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Among the various developing countries in the world like China, Malaysia, Korea etc., India is also developing its infrastructures in the form of Road/Rail/Airports and Waterborne facilities at an exponential rate. Mumbai, the financial epicenter of India is overcrowded and to relieve the pressure of congestion, Navi Mumbai suburb is being developed on the east bank of Thane creek near Mumbai. The government due to limited space at existing Mumbai Airports (domestic and international) to cater for the future demand of airborne traffic, proposes to build a new international airport near Panvel at Navi Mumbai. Considering the precedence of extreme rainfall on 26^th July 2005 and nearby townships being in a low-lying area, wherein new airport is proposed, it is inevitable to study this complex confluence area from a hydrodynamic consideration under both tidal and extreme events (predicted discharge hydrographs), to avoid inundation of the surrounding due to the proposed airport reclamation (1160 hectares) and to determine the safe grade elevation (SGE). The model studies conducted using the application of unstructured mesh to simulate the Panvel estuarine area (93 km²), calibration, validation of a model for hydraulic field measurements and determine the maxima water levels around the airport for various extreme hydrodynamic events, namely the simultaneous occurrence of highest tide from the Arabian Sea and peak flood discharges (Probable Maximum Precipitation and 26^th July 2005) from five rivers, the Gadhi, Kalundri, Taloja, Kasadi and Ulwe, meeting at the proposed airport area revealed that: (a) The Ulwe River flowing beneath the proposed airport needs to be diverted. The 120m wide proposed Ulwe diversion channel having a wider base width of 200 m at SH-54 Bridge on the Ulwe River along with the removal of the existing bund in Moha Creek is inevitable to keep the SGE of the airport to a minimum. (b) The clear waterway of 80 m at SH-54 Bridge (Ulwe River) and 120 m at Amra Marg Bridge near Moha Creek is also essential for the Ulwe diversion and (c) The river bank protection works on the right bank of Gadhi River between the NH-4B and SH-54 bridges as well as upstream of the Ulwe River diversion channel are essential to avoid inundation of low lying areas. The maxima water levels predicted around the airport keeps SGE to a minimum of 11m with respect to Chart datum of Ulwe Bundar and thus development is not only technologically-economically feasible but also sustainable. The unstructured mesh modeling is a promising tool to simulate complex extreme hydrodynamic events and provides a reliable solution to evolve optimal SGE of airport.

Keywords: airport, hydrodynamics, safe grade elevation, tides

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Authors: Uzma Ahmad

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hyber Pakhtunkhwa (KPK) is the most turbulent province of Pakistan, sharing a longborder with Afghanistan. For about four decades, KPK is facing a series of international events. The peak was reached after 9/11when region was labelled as posing a major theatre of militancy and terrorism which was intensified when Tehrik Taliban Pakistan (TTP) began attempts to seize the authority of state. One of the main focus of TTP was to damage and uprooting of female education system and infrastructure in KPK which later became the site of a massacre of school children of Army Public School Peshawar on 16 December 2014.It resulted to the launching of Zarb-e-Azb against the TTP insurgency,casualty and crime rates in the KPKas a whole dropped by 40.0% as compared to 2011–13. All this has badly hampered the female education both in terms of quantity and quality. Malala Yousafzai who is now an advocate of female education has been a victim of Talibans brutality in that area. And thelanguage in which she managed to express herself to the International community is English.Keeping in view the situation, the present project was designed with a sole aim to focus on female students of the area which are few in numbers and to investigate some specific area, where they have been confronting problems in the use of grammar, vocabulary,tenses and organization of ideas in writings. The reasons might be the careless attitude, insufficient reading habits, lack of interest and poor knowledge of English language. The methodology was a descriptive one as it shows the effects of the internal efficiency(independent variables) on an intermediate college’s progress(dependent variables). It was a case study since data was collected from a focused group of 60 female students of arts and humanities at Swabi college at Intermediate level. The ultimate focus was to explore the possibilities of creating a Gender friendly environment for female students. This research has proved how the correct use of English language has given them confidence to move ahead side by side with men and to acknowledge their right of self-determination.

Keywords: capacity building, female education, gender friendly, internal efficiency

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Authors: Manal Elsayed Elkheshin, Rasha Saleh Mansour, Mohamed Fawzy Mohamed Eldnasury, Mamdouh Elbadry Mohamed

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This research Aims to identify the main factors affecting the production and the fish consumption in Egypt, through the econometric estimation for various forms functions of fish production and fish consumption during the period (1991-2014), as the aim of this research to forecast the production and the fish consumption in Egypt until 2020, through determine the best standard methods using (ARIMA).This research also aims to the economic feasibility of the production of fish in aquaculture farms study; investment cost and represents the value of land, buildings, equipment and irrigation. Aquaculture requires three types of fish (Tilapia, carp fish, and mullet fish), and the total area of the farm, about an acre. The annual Fish production from this project about 3.5 tons. The annual investment costs of about 50500 pounds, Find conclude that the project can repay the cost of their investments after about 4 years and 5 months, and therefore recommend the implementation of the project, and internal rate of return reached (IRR) of about 22.1%, where it is clear that the rate of large internal rate of return, and achieves pound invested in this project annual return is estimated at 22.1 pounds, more than the opportunity cost, so we recommend the need to implement the project.Recommendations:1. Increasing the fish agriculture to decrease the gap of animal protein. 2.Increasing the number of mechanism fishing boats, and the provision of transport equipped to maintain the quality of fish production. 3.Encourage and attract the local and foreign investments, providing advice to the investor on the aquaculture field. 4. Action newsletters awareness of the importance of these projects where these projects resulted in a net profit after recovery in less than five years, IRR amounted to about 23%, which is much more than the opportunity cost of a bank interest rate is about 7%, helping to create work and graduates opportunities, and contribute to the reduction of imports of the fish, and improve the performance of the food trade balance.

Keywords: equation model, individual share, red meat, consumption, production, endogenous variable, exogenous variable, financial performance evaluates fish culture, feasibility study, fish production, aquaculture

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Authors: Anatoly A. Kuznetsov, Pavel G. Berezhko, Sergey M. Kunavin, Eugeny V. Zhilkin, Maxim V. Tsarev, Vyacheslav V. Yaroshenko, Valery V. Mokrushin, Olga Y. Yunchina, Sergey A. Mityashin

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The acoustic emission is caused by short-time propagation of elastic waves that are generated as a result of quick energy release from sources localized inside some material. In particular, the acoustic emission phenomenon lies in the generation of acoustic waves resulted from the reconstruction of material internal structures. This phenomenon is observed at various physicochemical transformations, in particular, at those accompanying hydrogenation processes of metals or intermetallic compounds that make it possible to study parameters of these transformations through recording and analyzing the acoustic signals. It has been known that at the interaction between metals or inter metallides with hydrogen the most intensive acoustic signals are generated as a result of cracking or crumbling of an initial compact powder sample as a result of the change of material crystal structure under hydrogenation. This work is dedicated to the study into changes occurring in metallic titanium samples at their interaction with hydrogen and followed by acoustic emission signals. In this work the subjects for investigation were specimens of metallic titanium in two various initial forms: titanium sponge and fine titanium powder made of this sponge. The kinetic of the interaction of these materials with hydrogen, the acoustic emission signals accompanying hydrogenation processes and the structure of the materials before and after hydrogenation were investigated. It was determined that in both cases interaction of metallic titanium and hydrogen is followed by acoustic emission signals of high amplitude generated on reaching some certain value of the atomic ratio [H]/[Ti] in a solid phase because of metal cracking at a macrolevel. The typical sizes of the cracks are comparable with particle sizes of hydrogenated specimens. The reasons for cracking are internal stresses initiated in a sample due to the increasing volume of a solid phase as a result of changes in a material crystal lattice under hydrogenation. When the titanium powder is used, the atomic ratio [H]/[Ti] in a solid phase corresponding to the maximum amplitude of an acoustic emission signal are, as a rule, higher than when titanium sponge is used.

Keywords: acoustic emission signal, cracking, hydrogenation, titanium specimen

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Authors: Tanios Saliba, Jad Wakim, Elie Awwad

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Clayey soils exhibit undesirable problems in civil engineering project: poor bearing soil capacity, shrinkage, cracking, …etc. On the other hand, the increasing production of bottom ash and its disposal in an eco-friendly manner is a matter of concern. Soil stabilization using bottom ash is a new technic in the geo-environmental engineering. It can be used wherever a soft clayey soil is encountered in foundations or road subgrade, instead of using old technics such as cement-soil mixing. This new technology can be used for road embankments and clayey foundations platform (shallow or deep foundations) instead of replacing bad soil or using old technics which aren’t eco-friendly. Moreover, applying this new technic in our geotechnical engineering projects can reduce the disposal of the bottom ash problem which is getting bigger day after day. The research consists of mixing clayey soil with different percentages of bottom ash at different values of water content, and evaluates the mechanical properties of every mix: the percentages of bottom ash are 10% 20% 30% 40% and 50% with values of water content of 25% 35% and 45% of the mix’s weight. Before testing the different mixes, clayey soil’s properties were determined: Atterbeg limits, soil’s cohesion and friction angle and particle size distribution. In order to evaluate the mechanical properties and behavior of every mix, different tests are conducted: -Direct shear test in order to determine the cohesion and internal friction angle of every mix. -Unconfined compressive strength (stress strain curve) to determine mix’s elastic modulus and compressive strength. Soil samples are prepared in accordance with the ASTM standards, and tested at different times, in order to be able to emphasize the influence of the curing period on the variation of the mix’s mechanical properties and characteristics. As of today, the results obtained are very promising: the mix’s cohesion and friction angle vary in function of the bottom ash percentage, water content and curing period: the cohesion increases enormously before decreasing for a long curing period (values of mix’s cohesion are larger than intact soil’s cohesion) while internal friction angle keeps on increasing even when the curing period is 28 days (the tests largest curing period), which give us a better soil behavior: less cracks and better soil bearing capacity.

Keywords: bottom ash, Clayey soil, mechanical properties, tests

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Authors: Subrat Partha Sarathi Pattnaik, Rajan N.K.S.

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Integrated rocket ramjet engines are highly suitable for long range missile applications. Designing the fixed geometry intakes for such missiles that can operate efficiently over a range of operating conditions is a highly challenging task. Hence, the present study aims to evaluate the effect of throat design on the performance of a rectangular mixed compression intake for operation in the Mach number range of 1.8 – 2.5. The analysis has been carried out at four different Mach numbers of 1.8, 2, 2.2, 2.5 and two angle-of-attacks of +5 and +10 degrees. For the throat design, three different throat heights have been considered, one corresponding to a 3- external shock design and two heights corresponding to a 2-external shock design leading to different internal contraction ratios. The on-design Mach number for the study is M 2.2. To obtain the viscous flow field in the intake, the theoretical designs have been considered for computational fluid dynamic analysis. For which Favre averaged Navier- Stokes (FANS) equations with two equation SST k-w model have been solved. The analysis shows that for zero angle of attack at on-design and high off-design Mach number operations the three-ramp design leads to a higher total pressure recovery (TPR) compared to the two-ramp design at both contraction ratios maintaining same mass flow ratio (MFR). But at low off-design Mach numbers the total pressure shows an opposite trend that is maximum for the two-ramp low contraction ratio design due to lower shock loss across the external shocks similarly the MFR is higher for low contraction ratio design as the external ramp shocks move closer to the cowl. At both the angle of attack conditions and complete range of Mach numbers the total pressure recovery and mass flow ratios are highest for two ramp low contraction design due to lower stagnation pressure loss across the detached bow shock formed at the ramp and lower mass spillage. Hence, low contraction design is found to be suitable for higher off-design performance.

Keywords: internal contraction ratio, mass flow ratio, mixed compression intake, performance, supersonic flows

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Authors: O. Fiquet, P. Lemarignier

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Additive manufacturing may find numerous applications in the nuclear industry, for the same reason as for other industries, to enlarge design possibilities and performances and develop fabrication methods as a flexible route for future innovation. Additive Manufacturing applications in the design of structural metallic components for reactors are already developed at a high Technology Readiness Level (TRL). In the case of a Pressured Water Reactor using uranium oxide fuel pellets, which are ceramics, the transposition of already optimized Additive Manufacturing (AM) processes to UO₂ remains a challenge, and the progress remains slow because, to our best knowledge, only a few laboratories have the capability of developing processes applicable to UO₂. After the Fukushima accident, numerous research fields emerged with the study of ATF (Accident tolerant Fuel) fuel concepts, which aimed to improve fuel behaviour. One item concerns the increase of the pellet thermal performance by, for example, the addition of high thermal conductivity material into fissile UO₂. This additive phase may be metallic, and the end product will constitute a CERMET composite. Innovative designs of an internal metallic framework are proposed based on predictive calculations. However, because the well-known reference pellet manufacturing methods impose many limitations, manufacturing such a composite remains an arduous task. Therefore, the AM process appears as a means of broadening the design possibilities of CERMET manufacturing. If the external form remains a standard cylindrical fuel pellet, the internal metallic design remains to be optimized based on process capabilities. This project also considers the limitation to a maximum of 10% volume of metal, which is a constraint neutron physics considerations impose. The AM technique chosen for this development is robocasting because of its simplicity and low-cost equipment. It remains, however, a challenge to adapt a ceramic 3D printing process for the fabrication of UO₂ fuel. The investigation starts with surrogate material, and the optimization of slurry feedstock is based on alumina. The paper will present the first printing of Al2O3-Mo CERMET and the expected transition from ceramic-based alumina to UO₂ CERMET.

Keywords: nuclear, fuel, CERMET, robocasting

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Authors: Sadok Aboubakr

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The mechanical behavior of cracks from several manufacturing defect in an oil pipeline, is characterized by the fact that defects'm taking several forms: circumferential, longitudinal and inclined crack that evolve over time. Increased lifetime of the constructions and in particular cylindrical tubes under internal pressure requires knowledge improving these defects during loading. From this study we simulated various forms of cracking and also their pipeline repair patch.

Keywords: stress intensity factor, pressure, Young's modulus, Poisson's ratio, Shear modulus, Longueur du pipeline, the angle of crack, crack length

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Authors: Jagdish Prasad Sahoo

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The increase in active earth pressure during the event of an earthquake results sliding, overturning and tilting of earth retaining structures. In order to improve upon the stability of structures, the soil mass is often reinforced with various types of reinforcements such as metal strips, geotextiles, and geogrids etc. The stresses generated in the soil mass are transferred to the reinforcements through the interface friction between the earth and the reinforcement, which in turn reduces the lateral earth pressure on the retaining walls. Hence, the evaluation of earth pressure in the presence of seismic forces with an inclusion of reinforcements is important for the design retaining walls in the seismically active zones. In the present analysis, the effect of reinforcing horizontal layers of reinforcements in the form of sheets (Geotextiles and Geogrids) in sand used as backfill, on reducing the active earth pressure due to earthquake body forces has been studied. For carrying out the analysis, pseudo-static approach has been adopted by employing upper bound theorem of limit analysis in combination with finite elements and linear optimization. The computations have been performed with and out reinforcements for different internal friction angle of sand varying from 30 ° to 45 °. The effectiveness of the reinforcement in reducing the active earth pressure on the retaining walls is examined in terms of active earth pressure coefficient for presenting the solutions in a non-dimensional form. The active earth pressure coefficient is expressed as functions of internal friction angle of sand, interface friction angle between sand and reinforcement, soil-wall interface roughness conditions, and coefficient of horizontal seismic acceleration. It has been found that (i) there always exists a certain optimum depth of the reinforcement layers corresponding to which the value of active earth pressure coefficient becomes always the minimum, and (ii) the active earth pressure coefficient decreases significantly with an increase in length of reinforcements only up to a certain length beyond which a further increase in length hardly causes any reduction in the values active earth pressure. The optimum depth of the reinforcement layers and the required length of reinforcements corresponding to the optimum depth of reinforcements have been established. The numerical results developed in this analysis are expected to be useful for purpose of design of retaining walls.

Keywords: active, finite elements, limit analysis, presudo-static, reinforcement

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Authors: Mitsunobu Iwasaki, Akifumi Iseda

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Yttrium aluminum garnet doped with cerium (Ⅲ) ions (Y3Al5O12:Ce3+, YAG:Ce3+) has attracted a great attention because it can efficiently convert the blue light into a very broad yellow emission band, which produces white light emitting diodes and is applied for panel displays. To improve the brightness and resolution of the display, a considerable attention has been directed to develop fine phosphor particles. We have prepared YAG:Ce3+ nanophosphors by environmental-friendly wet process. The peak maximum of absorption spectra of surface plasmon of Ag nanopaticles are close to that of the excitation spectra (460 nm) of YAG:Ce3+. It can be expected that Ag nanoparticles supported onto the surface of YAG:Ce3+ (Ag-YAG:Ce3+) enhance the absorption of Ce3+ ions. In this study, we have prepared Ag-YAG:Ce3+ nanophosphors and investigated their photoluminescent properties. YCl3･6H2O and AlCl3･6H2O with a molar ratio of Y:Al=3:5 were dissolved in ethanol (100 ml), and CeCl3•7H2O (0.3 mol%) was further added to the above solution. Then, NaOH (4.6×10-2 mol) dissolved in ethanol (50 ml) was added dropwise to the mixture under reflux over 2 hours, and the solution was further refluxed for 1 hour. After cooling to room temperature, precipitates in the reaction mixture were heated at 673 K for 1 hour. After the calcination, the particles were immersed in AgNO3 solution for 1 hour, followed by sintering at 1123 K for 1 hour. YAG:Ce3+ were confirmed to be nanocrystals with a crystallite size of 50-80 nm in diameter. Ag nanoparticles supported onto YAG:Ce3+ were single nanometers in diameter. The excitation and emission spectra were 454 nm and 539 nm at a maximum wavelength, respectively. The emission intensity was maximum for Ag-YAG:Ce3+ immersed into 0.5 mM AgCl (Ag-YAG:Ce (0.5 mM)). The absorption maximum (461 nm) was increased for Ag-YAG:Ce3+ in comparison with that for YAG:Ce3+, indicating that the absorption was enhanced by the addition of Ag. The external and internal quantum efficiencies became 11.2 % and 36.9 % for Ag-YAG:Ce (0.5 mM), respectively. The emission intensity and absorption maximum of Ag-YAG:Ce (0.5 mM)×n (n=1, 2, 3) were increased with an increase of the number of supporting times (n), respectively. The external and internal quantum efficiencies were increased for the increase of n, respectively. The external quantum efficiency of Ag-YAG:Ce (0.5 mM) (n=3) became twice as large as that of YAG:Ce. In conclusion, Ag nanoparticles supported onto YAG:Ce3+ increased absorption and quantum efficiency. Therefore, the support of Ag nanoparticles enhanced the photoluminescent properties of YAG:Ce3+.

Keywords: plasmon, quantum efficiency, silver nanoparticles, yttrium aluminum garnet

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Authors: Felipe J. Costa, João F. A. Martos, Ronaldo L. Cardoso, Israel S. Rêgo, Marco A. S. Minucci, Antonio C. Oliveira, Paulo G. P. Toro

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The Prof. Henry T. Nagamatsu Laboratory of Aerothermodynamics and Hypersonics, at the Institute for Advanced Studies designed the Brazilian 14-X Hypersonic Aerospace Vehicle, which is a technological demonstrator endowed with two innovative technologies: waverider technology, to obtain lift from conical shockwave during the hypersonic flight; and uses hypersonic airbreathing propulsion system called scramjet that is based on supersonic combustion, to perform flights on Earth's atmosphere at 30 km altitude at Mach numbers 7 and 10. The scramjet is an aeronautical engine without moving parts that promote compression and deceleration of freestream atmospheric air at the inlet through the conical/oblique shockwaves generated during the hypersonic flight. During high speed flight, the shock waves and the viscous forces yield the phenomenon called aerodynamic heating, where this physical meaning is the friction between the fluid filaments and the body or compression at the stagnation regions of the leading edge that converts the kinetic energy into heat within a thin layer of air which blankets the body. The temperature of this layer increases with the square of the speed. This high temperature is concentrated in the boundary-layer, where heat will flow readily from the boundary-layer to the hypersonic aerospace vehicle structure. Fay and Riddell and Eckert methods are applied to the stagnation point and to the flat plate segments in order to calculate the aerodynamic heating. On the understanding of the aerodynamic heating it is important to analyze the heat conduction transfer to the 14-X waverider internal structure. ANSYS Workbench software provides the Thermal Numerical Analysis, using Finite Element Method of the 14-X waverider unpowered scramjet at 30 km altitude at Mach number 7 and 10 in terms of temperature and heat flux. Finally, it is possible to verify if the internal temperature complies with the requirements for embedded systems, and, if is necessary to do modifications on the structure in terms of wall thickness and materials.

Keywords: aerodynamic heating, hypersonic, scramjet, thermal analysis

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Authors: Mohamad Bolandmartabe, Nafiseh Hassani, Saeed Abdi Darake, Maryam Asghari

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Dogs are highly susceptible to diseases, nutritional problems, toxins, and parasites, with parasitic infections being common and causing hardship in their lives. Some important internal parasites include worms (such as roundworms and tapeworms) and protozoa, which can lead to anemia in dogs. Important bloodborne parasites in dogs include microfilariae and adult forms of Dirofilaria immitis, Dipetalonema reconditum, Babesia, Trypanosoma, Hepatozoon, Leishmania, Ehrlichia, and Hemobartonella. Babesia and Hemobartonella are parasites that reside inside red blood cells and cause regenerative anemia by directly destroying the red blood cells. Hepatozoon, Leishmania, and Ehrlichia are also parasites that reside within white blood cells and can infiltrate other tissues, such as the liver and lymph nodes. Since intermediate hosts are more commonly found in the open environment, the prevalence of parasites in stray and free-roaming dogs is higher compared to pet dogs. Furthermore, pet dogs are less exposed to internal and external parasites due to better care, hygiene, and being predominantly indoors. Therefore, they are less likely to be affected by them. Among the parasites, Leishmania carries significant importance as it is shared between dogs and humans, causing a dangerous disease known as visceral Leishmaniasis or kala-azar and cutaneous Leishmaniasis. Furthermore, dogs can act as reservoirs and spread the disease agent within human communities. Therefore, timely and accurate diagnosis of these diseases in dogs can be highly beneficial in preventing their occurrence in humans. In this article, we employed the Giemsa staining technique under a light microscope for the identification of bloodborne parasites in dogs. However, considering the negative impact of these parasites on the natural life of dogs, the development of chronic diseases, and the gradual loss of the animal's well-being, rapid and timely diagnosis is essential. Serological methods and PCR are available for the diagnosis of certain parasites, which have high sensitivity and desirable characteristics. Therefore, this research aims to investigate the molecular aspects of bloodborne parasites in dogs referred to veterinary hospitals in Tehran city.

Keywords: leishmaniasis, babesiosis, ehrlichiosis, dirofilariasis, hepatozoonosis

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Authors: H. Yousefnia, S. Zolghadri, S. Shanesazzadeh, A.Lahooti, A. R. Jalilian

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In this study, 68Ga-ECC and 67Ga-ECC were both prepared with the radiochemical purity of higher than 97% in less than 30 min. The biodistribution data for 68Ga-ECC showed the extraction of the most of the activity from the urinary tract. The absorbed dose was estimated based on biodistribution data in mice by the medical internal radiation dose (MIRD) method. Comparison between human absorbed dose estimation for these two agents indicated the values of approximately ten-fold higher after injection of 67Ga-ECC than 68Ga-ECC in the most organs. The results showed that 68Ga-ECC can be considered as a more potential agent for renal imaging compared to 67Ga-ECC.

Keywords: effective absorbed dose, ethylenecysteamine cysteine, Ga-67, Ga-68

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Authors: Richa Dhingra, Monika, Manav Malhotra, Tilak Raj Bhardwaj, Neelima Dhingra

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5-Alpha-reductases (5AR), a membrane bound, NADPH dependent enzyme and convert male hormone testosterone (T) into more potent androgen dihydrotestosterone (DHT). DHT is the required for the development and function of male sex organs, but its overproduction has been found to be associated with physiological conditions like Benign Prostatic Hyperplasia (BPH). Thus the inhibition of 5ARs could be a key target for the treatment of BPH. In present study, 2D and 3D Quantitative Structure Activity Relationship (QSAR) pharmacophore models have been generated for 5AR based on known inhibitory concentration (IC₅₀) values with extensive validations. The four featured 2D pharmacophore based PLS model correlated the topological interactions (–OH group connected with one single bond) (SsOHE-index); semi-empirical (Quadrupole2) and physicochemical descriptors (Mol. wt, Bromines Count, Chlorines Count) with 5AR inhibitory activity, and has the highest correlation coefficient (r² = 0.98, q² =0.84; F = 57.87, pred r² = 0.88). Internal and external validation was carried out using test and proposed set of compounds. The contribution plot of electrostatic field effects and steric interactions generated by 3D-QSAR showed interesting results in terms of internal and external predictability. The well validated 2D Partial Least Squares (PLS) and 3D k-nearest neighbour (kNN) models were used to search novel 5AR inhibitors with different chemical scaffold. To gain more insights into the molecular mechanism of action of these steroidal derivatives, molecular docking and in silico absorption, distribution, metabolism, and excretion (ADME) studies were also performed. Studies have revealed the hydrophobic and hydrogen bonding of the ligand with residues Alanine (ALA) 63A, Threonine (THR) 60A, and Arginine (ARG) 456A of 4AT0 protein at the hinge region. The results of QSAR, molecular docking, in silico ADME studies provide guideline and mechanistic scope for the identification of more potent 5-Alpha-reductase inhibitors (5ARI).

Keywords: 5α-reductase inhibitor, benign prostatic hyperplasia, ligands, molecular docking, QSAR

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Authors: T. Konst

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Most jobs include training and communication tasks, but often the people in these jobs lack pedagogical competences to plan, implement and assess learning. This paper aims to discuss how a learning approach called innovation pedagogy developed in higher education can be utilized for learning development in various organizations. The methods presented how to implement innovation pedagogy such as process consultation and train the trainer model can provide added value to develop pedagogical knowhow in organizations and thus support their internal learning and development.

Keywords: innovation pedagogy, learning, organizational development, process consultation

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Authors: Wilfred A. Abiaa, Chibundu N. Ezekiel, Benedikt Warth, Michael Sulyok, Paul C. Turner, Rudolf Krska, Paul F. Moundipa

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Mycotoxins are a wide range of toxic secondary metabolites of fungi that contaminate various food commodities worldwide especially in sub-Saharan Africa (SSA). Such contamination seriously compromises food safety and quality posing a serious problem for human health as well as to trade and the economy. Their concentrations depend on various factors, such as the commodity itself, climatic conditions, storage conditions, seasonal variances, and processing methods. When humans consume foods contaminated by mycotoxins, they exert toxic effects to their health through various modes of actions. Rural populations in sub-Saharan Africa, are exposed to dietary mycotoxins, but it is supposed that exposure levels and health risks associated with mycotoxins between SSA countries may vary. Dietary exposures and health risk assessment studies have been limited by lack of equipment for the proper assessment of the associated health implications on consumer populations when they eat contaminated agricultural products. As such, mycotoxin research is premature in several SSA nations with product evaluation for mycotoxin loads below/above legislative limits being inadequate. Few nations have health risk assessment reports mainly based on direct quantification of the toxins in foods ('external exposure') and linking food levels with data from food frequency questionnaires. Nonetheless, the assessment of the exposure and health risk to mycotoxins requires more than the traditional approaches. Only a fraction of the mycotoxins in contaminated foods reaches the blood stream and exert toxicity ('internal exposure'). Also, internal exposure is usually smaller than external exposure thus dependence on external exposure alone may induce confounders in risk assessment. Some studies from SSA earlier focused on biomarker analysis mainly on aflatoxins while a few recent studies have concentrated on the multi-biomarker analysis of exposures in urine providing probable associations between observed disease occurrences and dietary mycotoxins levels. As a result, new techniques that could assess the levels of exposures directly in body tissue or fluid, and possibly link them to the disease state of individuals became urgent.

Keywords: mycotoxins, biomarkers, exposure assessment, health risk assessment, sub-Saharan Africa

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Authors: Binaya Tamang, Buddhhi Raj Pokhrel, Narayan Gautam

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Background: There may be a connection between thyroid function and vitamin D status since both bind to similar nuclear hormone receptors and have similar response regions on gene promoters. The purpose of the current study was to investigate the relationship between thyroid hormones and vitamin D levels in females who were attending a tertiary care center in western Nepal and were either hypothyroid or euthyroid. Methods: This hospital-based cross-sectional study was carried out between March 2020 and March 2021 by the Biochemistry department of the Universal College of Medical Sciences (UCMS), Bhairahawa, Province No. 5, Nepal, in cooperation with Internal medicine. Prior to the study, institutional review committee approval (UCMS/IRC/008/20) was acquired from UCMS. Women who visited the Internal Medicine OPD of UCMS and were advised to get a thyroid function test (TFT) were included in the study population. Only those who were willing to participate in the study were enrolled after the goals and advantages of the study had been explained to them. Participants who had recently used vitamin D supplements and medications that affected thyroid hormones were excluded. The participants gave their consent verbally and in writing. After getting the consent, a convenient sample technique was applied. Serum was isolated after drawing 3 ml of blood in a plain vial. Chemiluminescence assay was used to analyze vitamin D and thyroid hormones (MAGLUMI 2000). SPSS version 16.0 for Windows was used to conduct the statistical analysis. Statistical significance was defined as a P-value < 0.05. Results: Majority of the study population (n=214, 71%) had insufficient serum vitamin D levels. Among the thyroid groups, the median Vitamin D levels were significantly lower in hypothyroid (16.88 ng/ml) as compared to the euthyroid groups (25.01 ng/ml) (P<0.001). Similarly, serum Vitamin D levels were considerably lower in the obese population (16.86 ng/ml) as compared to the normal BMI group (24.90 ng/ml) (P<0.001) as well as in the vegetarian (15.43 ng.ml) than mixed diet consumer (24.89 ng/ml) (P<0.01). Even after the adjustment for these variables, the Vitamin D levels were significantly lower in the hypothyroid population than in the euthyroid group (P<0.001). Conclusion: Comparing the hypothyroid population to the euthyroid, the median serum vitamin D levels were considerably lower. We were alarmed to see that the majority of euthyroid participants also had low levels of vitamin D. Therefore if left untreated, low vitamin D levels in hypothyroid patients could worsen their health further.

Keywords: vitamin D, thyroid hormones, euthyroid, hypothyroid, Nepal

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Authors: Jaan-Willem Simon, Bertram Stier, Brett Bednarcyk, Evan Pineda, Stefanie Reese

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Textile composites, in which the reinforcing fibers are woven or braided, have become very popular in numerous applications in aerospace, automotive, and maritime industry. These textile composites are advantageous due to their ease of manufacture, damage tolerance, and relatively low cost. However, physics-based modeling of the mechanical behavior of textile composites is challenging. Compared to their unidirectional counterparts, textile composites introduce additional geometric complexities, which cause significant local stress and strain concentrations. Since these internal concentrations are primary drivers of nonlinearity, damage, and failure within textile composites, they must be taken into account in order for the models to be predictive. The macro-scale approach to modeling textile-reinforced composites treats the whole composite as an effective, homogenized material. This approach is very computationally efficient, but it cannot be considered predictive beyond the elastic regime because the complex microstructural geometry is not considered. Further, this approach can, at best, offer a phenomenological treatment of nonlinear deformation and failure. In contrast, the mesoscale approach to modeling textile composites explicitly considers the internal geometry of the reinforcing tows, and thus, their interaction, and the effects of their curved paths can be modeled. The tows are treated as effective (homogenized) materials, requiring the use of anisotropic material models to capture their behavior. Finally, the micro-scale approach goes one level lower, modeling the individual filaments that constitute the tows. This paper will compare meso- and micro-scale approaches to modeling the deformation, damage, and failure of textile-reinforced polymer matrix composites. For the mesoscale approach, the woven composite architecture will be modeled using the finite element method, and an anisotropic damage model for the tows will be employed to capture the local nonlinear behavior. For the micro-scale, two different models will be used, the one being based on the finite element method, whereas the other one makes use of an embedded semi-analytical approach. The goal will be the comparison and evaluation of these approaches to modeling textile-reinforced composites in terms of accuracy, efficiency, and utility.

Keywords: multiscale modeling, continuum damage model, damage interaction, textile composites

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Authors: Mohammad Arshad Ikram

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We report three cases of challenging fractures in children treated by intramedullary fixation using the Metaizeau method and achieved anatomical reduction with excellent clinical results. Jean-Paul Metaizeau described the centromedullary fixation for the radial neck in 1980 using K-wires Radial neck fractures are uncommon in children. Treatment of severely displaced fractures is always challenging. Closed reduction techniques are more popular as compared to open reduction due to the low risk of complications. Metaizeau technique of closed reduction with centromedullary pinning is a commonly preferred method of treatment. We present two cases with a severely displaced radial neck fracture, treated by this method and achieved sound union; anatomical position of the radial head and full function were observed two months after surgery. Proximal humerus fractures are another uncommon injury in children accounting for less than 5% of all pediatric fractures. Most of these injuries occur through the growth plate because of its relative weakness. Salter-Harris type I is commonly seen in the younger age group, whereas type II & III occurs in older children and adolescents. In contrast to adults, traumatic glenohumeral dislocation is an infrequently observed condition among children. A combination of proximal humerus fracture and glenohumeral dislocation is extremely rare and occurs in less than 2% of the pediatric population. The management of this injury is always challenging. Treatment ranged from closed reduction with and without internal fixation and open reduction with internal fixation. The children who had closed reduction with centromedullary fixation by the Metaizeau method showed excellent results with the return of full movements at the shoulder in a short time without any complication. We present the case of a child with anterior dislocation of the shoulder associated with a complete displaced proximal humerus metaphyseal fracture. The fracture was managed by closed reduction and then fixation by two centromedullary K-wires using the Metaizeau method, achieving the anatomical reduction of the fracture and dislocation. This method of treatment enables us to achieve excellent radiological and clinical results in a short time.

Keywords: glenohumeral, Metaizeau method, pediatric fractures, radial neck

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Authors: Mohammad Umar Azizi, Tetsuya Ando

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This study investigates the transformation of the traditional landscape of Kabul Old City through an examination of five case study areas. Based on physical observation, three types of houses are found: traditional, mixed and modern. Firstly, characteristics of the houses are described according to construction materials and the number of stories. Secondly, internal and external factors are considered in order to implement a conservation plan. Finally, an adaptive conservation plan is suggested to protect the traditional landscape of Kabul Old City.

Keywords: conservation, district 1, Kabul Old City, landscape, transformation, traditional houses

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Authors: Anuja Askhedkar, G. H. Agrawal, Madhu Gudgunti

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Direct Charge Transfer Switched Capacitor (DCT-SC) DAC is the internal DAC used in Delta-Sigma (∆∑) DAC which works on Over-Sampling concept. The Switched Capacitor DAC mainly suffers from mismatch among capacitors. Mismatch among capacitors in DAC, causes non linearity between output and input. Dynamic Element Matching (DEM) technique is used to match the capacitors. According to element selection logic there are many types. In this paper, Data Weighted Averaging (DWA) technique is used for mismatch shaping. In this paper, the 4 bit DCT-SC-DAC with DWA-DEM technique is implemented using WINSPICE simulation software in 180nm CMOS technology. DNL for DAC with DWA is ±0.03 LSB and INL is ± 0.02LSB.

Keywords: ∑-Δ DAC, DCT-SC-DAC, mismatch shaping, DWA, DEM

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Authors: Yolanda Ramirez, Angel Tejada, Agustin Baidez

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In the knowledge-based economy, intangible elements are considered essential in order to achieve competitive advantage in organizations. In this sense, the Balanced Scorecard is a very suitable tool to recognize value and manage intangibles because it translates an organization’s strategic objectives into a set of performance indicators from a financial, as well as customer perspective, internal process and learning and growth perspectives. The aim of this paper is to expose and justify the benefits that the Balanced Scorecard might have for identifying, measuring and managing intellectual capital at universities, by means of reviewing the most important Balanced Scorecard implementations at Spanish public universities.

Keywords: knowledge management, balanced scorecard, universities, Spain

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Authors: Mohammadreza DaqiqShirazi, Rouhollah Torabi, Alireza Riasi, Ahmad Nourbakhsh

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In this paper, the flow in a sidewall gap of an impeller which belongs to a centrifugal pump is studied using numerical method. The flow in sidewall gap forms internal leakage and is the source of “disk friction loss” which is the most important cause of reduced efficiency in low specific speed centrifugal pumps. Simulation is done using CFX software and a high quality mesh, therefore the modeling error has been reduced. Navier-Stokes equations have been solved for this domain. In order to predict the turbulence effects the SST model has been employed.

Keywords: numerical study, centrifugal pumps, disk friction loss, sidewall gap

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Authors: İsmail Seçer

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Although depression and anxiety disorders are considered to be adult disorders, the evidence obtained from several studies conducted recently shows that the roots of depression and anxiety disorders go back to childhood years. Thus, it is thought that analyzing depressive symptoms and anxiety disorders observed in the childhood is an important necessity. In the direction of the problem status of the study, the purpose of this study is to adapt anxiety and depression questionnaire for children into Turkish culture and analyze the psychometric characteristics of it on clinical and nonclinical samples separately. The study is a descriptive survey research. The study was conducted on two different sample groups, clinical and nonclinical. The clinical sample is formed of 205 individuals and the nonclinical sample is formed of 630 individuals. Through the study, anxiety and depression questionnaire for children, anxiety sensitivity index and obsessive compulsive disorder questionnaire for children were used. Experts’ opinions were asked to provide language validity of the scale. Confirmatory factor analysis and criterion-related validity to analyze construct validity and internal consistency and split-half reliability analyses were done for reliability. In the direction of experts’ opinions, construct validity of the scale was analyzed with simple confirmatory factor analysis and it was determined that the model fit of the two-factor structure of the scale gives good fit on both the clinical and nonclinical samples after determining that the language validity of the scale is provided. In criterion-related validity, it was determined that there are positive and significant relations between anxiety and depression questionnaire for children and anxiety sensitivity and obsessive compulsive disorder. The results of internal consistency and half-split reliability analyses also show that the scale has adequate reliability value. It can be said that depression and anxiety questionnaire for children which was adapted to determine depressive symptoms and anxiety disorders observed in childhood has adequate reliability and validity values and it can be used in future studies. It can be recommended that the psychometric characteristics of the scale can be analyzed and reported on new samples in the future studies.

Keywords: scale adapting, construct validity, confirmatory factor analysis, childhood depression

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Authors: Nuruddin Mohammod Zahangir, Syed Tanvir Ahmady, Firoz Ahmed, Mainul Kabir, Tamjid Mohammad Najmus Sakib Khan, Nazmul Hossain, Niaz Ahmed, Madhava Janardhan Naik

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The management of combined Coronary Artery Disease and Peripheral Vascular Disease is a challenge and brings with it numerous clinical dilemmas.The 56 year old gentleman presented to our department with significant triple vessel disease with occluded lower end of aorta just before bifurcation and bilateral superficial femoral arteries. Operation was done on 11.03.14. The The Left Internal Mammary Artery (LIMA) and the Right Internal Mammary Artery (RIMA) were harvested in skeletonized manner. The free RIMA was then anastomosed with LIMA to make LIMA-RIMA Y. Cardio Pulmonary Bypass was then established and coronary artery bypass grafts performed. LIMA was anastomosed to the Left Anterior Descending artery. RIMA was anastomosed to Posterior Descending Artery, 1st and 2nd Obtuse Marginal arteries in a sequential manner. Abdomen was opened by midline incision. The infrarenal aorta exposed and was found to be severely diseased. A Vascular Clamp was applied infrarenally, aortotomy done and limited endarterectomy performed. An end-to-side anastomosis was done with upper end of PTFE synthetic Y-graft (14/7 mm) to the infarenal Aorta and the Clamp released. Good flow noted in both limbs of the graft. Patient was then slowly weaned off from Cardio Pulmonary Bypass without difficulty. The distal two limbs of the Y graft were passed to the groin through retroperitoneal tunnels and anastomosed end-to-side with the common femoral arteries. Saphenous vein was interposed between common femoral and popliteal arteries bilaterally through subfascial tunnels in both thigh. On 12th postoperative day he was discharged from hospital in good general condition. Follow up after 3 months of operation the patient is doing good and free of chest pain and claudication pain.

Keywords: total arterial, coronary revascularization, aorto-bifemoral bypass, bifemoro-bipopliteal bypass

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Authors: Fazli Idris, Jihad Mohammad

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The study aims to determine the impact of technology and service operations flexibility, which is divided into external flexibility and internal robustness, on operations costs. A mediation model is proposed that links technology to operations costs via operation flexibility. Drawing on a sample of 475 of operations managers of various service sectors in Malaysia and South Africa, Structural Equation Modeling (SEM) was employed to test the relationship using Smart-PLS procedures. It was found that a significant relationship was established between technologies to operations costs via both operations flexibility dimensions. Theoretical and managerial implications are offered to explain the results.

Keywords: Operations flexibility, technology, costs, mediation

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Authors: R. Horchani

Abstract:

Optical pumping technique with laser fields combined with photo-association of ultra-cold atoms leads to control on demand the vibrational and/or the rotational population of molecules. Here, we review the basic concepts and main steps should be followed, including the excitation schemes and detection techniques we use to achieve the ro-vibrational cooling of Cs2 molecules. We also discuss the extension of this technique to other molecules. In addition, we present a theoretical model used to support the experiment. These simulations can be widely used for the preparation of various experiments since they allow the optimization of several important experimental parameters.

Keywords: cold molecule, photo-association, optical pumping, vibrational and rotational cooling

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