Search results for: section shutdown

Authors: Sara Vora (Hoxha)

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An essential feature of any international lawsuit is the ability of the parties to pick the law that would apply in the event of a tort claim. This option to choose the law to use in tort cases is based on Article 14 and 4/3 of the Rome II Regulation. The purpose of this article is to examine the boundaries of this freedom, as well as its relevance in international legal disputes. The article opens with a brief introduction to the basics of tort law. After a short introduction, the article demonstrates why Article 14 and 4/3 of the Rome II Regulation are so crucial to the right to select appropriate law in tort cases. The notion of the right to select the law to use in tort cases is examined, along with its breadth and possible restrictions. The article presents case studies to demonstrate how the right to select relevant law in tort might be put into practise. Case results and the judges' rationales for their rulings are examined. The possible influence of the right to select applicable law in tort on the process of harmonisation is also explored in this study. The results are summarised and the primary research question is addressed in the last section of the paper. In conclusion, the parties' ability to pick the law that rules their dispute via the freedom to choose relevant law in tort is a crucial feature of cross-border litigation. Despite certain restrictions, this freedom is nevertheless an important part of the legal structure that governs international conflicts.

Keywords: applicable law, tort, Rome II regulation, freedom to choose, cross-border litigation, harmonization of tort law

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Authors: Mohammed Mahmood, Walid Tizani, Carlo Sansour

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In this paper, experimental testing and numerical analysis were used to investigate the effect of tube thickness on the face bending for concrete filled hollow sections connected to other structural members using Extended Hollobolts. Six samples were tested experimentally by applying pull-out load on the bolts. These samples were designed to fail by column face bending. The main variable in all tests is the column face thickness. Finite element analyses were also performed using ABAQUS 6.11 to extend the experimental results and to quantify the effect of column face thickness. Results show that, the column face thickness has a clear impact on the connection strength and stiffness. However, the amount of improvement in the connection stiffness by changing the column face thickness from 5 mm to 6.3 mm seems to be higher than that when increasing it from 6.3 mm to 8 mm. The displacement at which the bolts start pulling-out from their holes increased with the use of thinner column face due to the high flexibility of the section. At the ultimate strength, the yielding of the column face propagated to the column corner and there was no yielding in its walls. After the ultimate resistance is reached, the propagation of the yielding was mainly in the column face with a miner yielding in the walls.

Keywords: anchored bolted connection, Extended Hollobolt, column faces bending, concrete filled hollow sections

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Authors: Juergen Orasche, Vesta Kohlmeier, George C. Dragan, Gert Jakobi, Patricia Forbes, Ralf Zimmermann

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Underground mining poses a difficult environment for both man and machines. At more than 1000 meters underneath the surface of the earth, ores and other mineral resources are still gained by conventional and motorised mining. Adding to the hazards caused by blasting and stone-chipping, the working conditions are best described by the high temperatures of 35-40°C and high humidity, at low air exchange rates. Separate ventilation shafts lead fresh air into a mine and others lead expended air back to the surface. This is essential for humans and machines working deep underground. Nevertheless, mines are widely ramified. Thus the air flow rate at the far end of a tunnel is sensed to be close to zero. In recent years, conventional mining was supplemented by mining with heavy diesel machines. These very flat machines called Load Haul Dump (LHD) vehicles accelerate and ease work in areas favourable for heavy machines. On the other hand, they emit non-filtered diesel exhaust, which constitutes an occupational hazard for the miners. Combined with a low air exchange, high humidity and inorganic dust from the mining it leads to 'black smog' underneath the earth. This work focuses on the air quality in mines employing LHDs. Therefore we performed personal sampling (samplers worn by miners during their work), stationary sampling and aethalometer (Microaeth MA200, Aethlabs) measurements in a platinum mine in around 1000 meters under the earth’s surface. We compared areas of high diesel exhaust emission with areas of conventional mining where no diesel machines were operated. For a better assessment of health risks caused by air pollution we applied a separated gas-/particle-sampling tool (or system), with first denuder section collecting intermediate VOCs. These multi-channel silicone rubber denuders are able to trap IVOCs while allowing particles ranged from 10 nm to 1 µm in diameter to be transmitted with an efficiency of nearly 100%. The second section is represented by a quartz fibre filter collecting particles and adsorbed semi-volatile organic compounds (SVOC). The third part is a graphitized carbon black adsorber – collecting the SVOCs that evaporate from the filter. The compounds collected on these three sections were analyzed in our labs with different thermal desorption techniques coupled with gas chromatography and mass spectrometry (GC-MS). VOCs and IVOCs were measured with a Shimadzu Thermal Desorption Unit (TD20, Shimadzu, Japan) coupled to a GCMS-System QP 2010 Ultra with a quadrupole mass spectrometer (Shimadzu). The GC was equipped with a 30m, BP-20 wax column (0.25mm ID, 0.25µm film) from SGE (Australia). Filters were analyzed with In-situ derivatization thermal desorption gas chromatography time-of-flight-mass spectrometry (IDTD-GC-TOF-MS). The IDTD unit is a modified GL sciences Optic 3 system (GL Sciences, Netherlands). The results showed black carbon concentrations measured with the portable aethalometers up to several mg per m³. The organic chemistry was dominated by very high concentrations of alkanes. Typical diesel engine exhaust markers like alkylated polycyclic aromatic hydrocarbons were detected as well as typical lubrication oil markers like hopanes.

Keywords: diesel emission, personal sampling, aethalometer, mining

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Authors: Huang Yueh Chen, Sheng Ang Shen

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Purpose: Sexual assault has always been a highly anticipated crime in Taiwan. People assume that the career of sexual offenders tends to be highly specialized. This study hopes to analyze the crime career and risk factors of offenders by means of another classification. Methods: A total of 145 sexual offenders were sentenced on the parole or expiration date from 2009 to 2011, through analysis of official existing documents such as ‘Re-infringement risk assessment report’ and ‘case assessment report’. Results: The section ‘Various Types of Crimes ‘ of criminal career is analyzed. The highest number of ‘ versatile sexual offender’ followed by ‘adult sexual offender’ is about 2.5, representing more than 1.5 kinds of non-sex crimes besides sexual crimes. Different specialized sexual offenders have had extensive experience in the ‘Sexual Assault Experiences in Children and School’, ‘Static 99 Levels’, ‘Pre-Commuted Substance Use’, ‘Excited Deviant Sexual Behavior’, ‘Various Types of Crimes,’ and ‘Sexual Crime in Forerunner’ , ‘Type of Index Crime’ and other projects to achieve significant differences. Conclusions: Resources continue to be devoted to specialized offenders, the character of first-time sexual offender depends on further research and makes the public aware of the different assumptions of diversified offenders from traditional professional offenses that reduce unnecessary panic in society.

Keywords: versatile sexual offender, specialized sexual offender, criminal career, risk factor

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Authors: Magaji Zainab Musa, Nordin M. A. Rahman, Julaily Aida Jusoh

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This paper discusses the formal specification of web services applications for digital reference services (WSDRS). Digital reference service involves a user requesting for help from a reference librarian and a reference librarian responding to the request of a user all by electronic means. In most cases users do not get satisfied while using digital reference service due to delay of response of the librarians. Another may be due to no response or due to librarian giving an irrelevant solution to the problem submitted by the user. WDSRS is an informal model that claims to reduce the problems of digital reference services in libraries. It uses web services technology to provide efficient way of satisfying users’ need in the reference section of libraries. But informal model is in natural language which is inconsistent and ambiguous that may cause difficulties to the developers of the system. In order to solve this problem we decided to convert the informal specifications into formal specifications. This is supposed to reduce the overall development time and cost. Formal specification can be used to provide an unambiguous and precise supplement to natural language descriptions. It can be rigorously validated and verified leading to the early detection of specification errors. We use Z language to develop the formal model and verify it with Z/EVES theorem prover tool.

Keywords: formal, specifications, web services, digital reference services

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Authors: Shafiullah Soomro

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Active contour is one of the image segmentation techniques and its goal is to capture required object boundaries within an image. In this paper, we propose a novel image segmentation method by using an active contour method based on anisotropic diffusion feature enhancement technique. The traditional active contour methods use only pixel information to perform segmentation, which produces inaccurate results when an image has some noise or complex background. We use Perona and Malik diffusion scheme for feature enhancement, which sharpens the object boundaries and blurs the background variations. Our main contribution is the formulation of a new SPF (signed pressure force) function, which uses global intensity information across the regions. By minimizing an energy function using partial differential framework the proposed method captures semantically meaningful boundaries instead of catching uninterested regions. Finally, we use a Gaussian kernel which eliminates the problem of reinitialization in level set function. We use several synthetic and real images from different modalities to validate the performance of the proposed method. In the experimental section, we have found the proposed method performance is better qualitatively and quantitatively and yield results with higher accuracy compared to other state-of-the-art methods.

Keywords: active contours, anisotropic diffusion, level-set, partial differential equations

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Authors: Vipul M. Patel, H. B. Mehta

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Closed Loop Pulsating Heat Pipe (CLPHP) is a passive two-phase heat transfer device having potential to achieve high heat transfer rates over conventional cooling techniques. It is found in electronics cooling due to its outstanding characteristics such as excellent heat transfer performance, simple, reliable, cost effective, compact structure and no external mechanical power requirement etc. Comprehensive understanding of the thermo-hydrodynamic mechanism of CLPHP is still lacking due to its contradictory results available in the literature. The present paper discusses the experimental study on 9 turn CLPHP. Inner and outer diameters of the copper tube are 2 mm and 4 mm respectively. The lengths of the evaporator, adiabatic and condenser sections are 40 mm, 100 mm and 50 mm respectively. Water is used as working fluid. The Filling Ratio (FR) is kept as 50% throughout the investigations. The gravitational effect is studied by placing the evaporator heater at different orientations such as horizontal (90 degree), vertical top (180 degree) and bottom (0 degree) as well as inclined top (135 degree) and bottom (45 degree). Heat input is supplied in the range of 10-50 Watt. Heat transfer mechanism is natural convection in the condenser section. Vacuum pump is used to evacuate the system up to 10^-5 bar. The results demonstrate the influence of input heat flux and gravity on the thermal performance of the CLPHP.

Keywords: CLPHP, gravity effect, start up, two-phase flow

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Authors: Samar Akef, Ahdab M. K. El-Morshedy, Mohamed M. Samy, Ahmed M. Emam

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This paper presents a safe and realistic design for the proposed high voltage direct current grounding grid for the converter station at Badr City in Egypt. The outcomes show that the estimated results for touch and step voltages are below the safe limits for humans in monopolar operation and fault conditions. The cross-section area of earthing conductor is computed using IEC TS 62344. The results show that touch voltage in monopolar and fault conditions are 46.6 V and 167.68 V, respectively. The optimum number of required earthing rods is obtained by an analytical method. The step voltages are 12.9 and 43 V in monopolar operation and fault conditions. In addition, this paper presents an experimental case study to verify the simulation work executed using CYMGrd software (finite element method based). The percentage error between the measured and simulated surface potential is below 15.9%.

Keywords: grounding, monopolar, fault conditions, step potential, touch potential, CYMGrd, finite element method, experimental case study

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Authors: Dina Dahood Dabash

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Palestine Refugee Camps have never been settings that can be overlooked; they even became (as physical settings) a cornerstone topic of negotiations whenever Palestinian matters are on the table (specifically in Jordan). Consequently, maintaining the familiar face of the camp with its dilapidated shelters and narrow streets that rarely allowed its residents to extinguish a fire or evacuate a building safely has become a fundamental method to protect the “right of the return” from the perspective of various stakeholders. When the Infrastructure and Camp Improvement Programme (ICIP) was established in 2007 as an additional UNRWA program, some concerns were raised around the newly established section, mainly due to its direct impact on the “image” of the camp through a provision of a relatively nonconventional service that differs from what the Agency used to provide in the past seventy years. By presenting the Urban Improvement Project in Jerash camp (UIP) -Jordan, this paper aims to contribute to the ongoing discussion around enduring the improvement of Palestine refugee camps “programmatically” in UNRWA or not. The UIP as a co-product by UNRWA and the camp’s community within one of the most vulnerable refugee camps in Jordan offers a remarkable opportunity to excerpt lessons that can contribute to the strategic shaping of the ICIP. The paper concludes with five mine uptakes mainly related to community engagement, power structures and UNRWA's role in camps.

Keywords: camp improvement program, Jerash camp, Palestine refugee camps, UNRWA.

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Authors: S. Tavuyanago

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Cartels within the international competition law framework have been dubbed the most egregious of competition law violations; this is because they entail a concerted effort by two or more competitor firms to knowingly ‘rob’ consumers of their welfare through their cooperation instead of competition. The net effect of cartel conduct is that the market is distorted as the colluding firms gain enough market power to constrain the supply of goods or services, ultimately driving up prices. As a result, consumers end up paying inflated prices for goods and services, which eventually affects their welfare. It is against this backdrop that competition authorities worldwide have mounted a robust fight against the proliferation of cartels. In South Africa, the fight against cartels saw an amendment to the Competition Act to allow for criminal prosecution of individuals who cause their firms to take part in cartels. The Competition Amendment Act 1 of 2009 introduced section 73A into the principal Competition Act, making it a criminal offence to engage in cartel conduct. This paper assesses the rationale for criminalisation of cartel conduct, discusses the challenges or potential challenges associated with criminalisation, and provides an evaluation of the efficacy of criminalisation of cartel conduct. It questions whether criminal sanctions for cartel conduct as a competition enforcement tool aimed at deterring such conduct are generally effective and whether they have been effective in South Africa specifically. It concludes by offering recommendations on how to effectively root out cartels.

Keywords: cartels, criminalisation, competition, deterrence, South Africa

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Authors: Pietro Mortini, Marco Losa

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Objective: Resection of large lesions growing into the third ventricle remains a demanding surgery, sometimes at risk of severe post-operative complications. Transcallosal and transcortical routes were considered as approaches of choice to access the third ventricle, however neurological consequences like memory loss have been reported. We report clinical results of the previously described combined interhemispheric sub-commissural translaminaterminalis approach (CISTA) for the resection of large lesions located in the third ventricle. Methods: Authors conducted a retrospective analysis on 10 patients, who were operated through the CISTA, for the resection of lesions growing into the third ventricle. Results: Total resection was achieved in all cases. Cognitive worsening occurred only in one case. No perioperative deaths were recorded and, at last follow-up, all patients were alive. One year after surgery 80% of patients had an excellent outcome with a KPS 100 and Glasgow Outcome score (GOS) Conclusion: The CISTA represents a safe and effective alternative to transcallosal and transcortical routes to resect lesions growing into the third ventricle. It allows for a multiangle trajectory to access the third ventricle with a wide working area free from critical neurovascular structures, without any section of the corpus callosum, the anterior commissure and the fornix.

Keywords: craniopharingioma, surgery, sub-commissural translaminaterminalis approach (CISTA),

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Authors: Abdulrahman Abdulrahman

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When the Manning equation is used, a unique value of normal depth in the uniform flow exists for a given channel geometry, discharge, roughness, and slope. Depending on the value of normal depth relative to the critical depth, the flow type (supercritical or subcritical) for a given characteristic of channel conditions is determined whether or not flow is uniform. There is no general solution of Manning's equation for determining the flow depth for a given flow rate, because the area of cross section and the hydraulic radius produce a complicated function of depth. The familiar solution of normal depth for a rectangular channel involves 1) a trial-and-error solution; 2) constructing a non-dimensional graph; 3) preparing tables involving non-dimensional parameters. Author in this paper has derived semi-analytical solution to Manning's equation for determining the flow depth given the flow rate in rectangular open channel. The solution was derived by expressing Manning's equation in non-dimensional form, then expanding this form using Maclaurin's series. In order to simplify the solution, terms containing power up to 4 have been considered. The resulted equation is a quartic equation with a standard form, where its solution was obtained by resolving this into two quadratic factors. The proposed solution for Manning's equation is valid over a large range of parameters, and its maximum error is within -1.586%.

Keywords: channel design, civil engineering, hydraulic engineering, open channel flow, Manning's equation, normal depth, uniform flow

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Authors: Hasan Izhar Khan, Naiqiang Zhang, Hong Xu, Zhongliang Zhu, Dongfang Jiang

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Inconel 617, a nickel-based alloy designed for high-temperature applications, got an excellent amalgamation of strength and oxidation resistance at high temperatures. For a better understanding of its suitability to be used in superheater and reheater tubes in ultra-supercritical power plants, stress corrosion cracking (SCC) susceptibility must be evaluated. In the present study, the effect of medium environment on SCC behavior of Inconel 617, in the form of a round bar tensile specimen, was tested via slow strain rate tensile tests in steam and supercritical water (SCW) at 650 °C. The results showed that SCC susceptibility has a linear relationship with exposed pressure and increases monotonically with an increase in pressure. A severe SCC susceptibility was observed in SCW followed by that in a steam environment. Fracture and gage surface showed apparent characteristics of brittle fracture. Intergranular cracks initiated from the edge region and propagated into the matrix through cross section until ductile rupture. When dissolved oxygen contents were decreased in SCW environment, it showed no noticeable effect on mechanical properties but SCC susceptibility slightly decreased. The research revealed the influence of environment on SCC susceptibility of Inconel 617 in steam and SCW.

Keywords: Inconel 617, steam, supercritical water, stress corrosion cracking

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Authors: Maurizio Dapor, Isabel Abril, Pablo de Vera, Rafael Garcia-Molina

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The ionization yield of ion tracks in polymers and bio-molecular systems reaches a maximum, known as the Bragg peak, close to the end of the ion trajectories. Along the path of the ions through the materials, many electrons are generated, which produce a cascade of further ionizations and, consequently, a shower of secondary electrons. Among these, very low energy secondary electrons can produce damage in the biomolecules by dissociative electron attachment. This work deals with the calculation of the energy distribution of electrons produced by protons in a sample of polymethylmethacrylate (PMMA), a material that is used as a phantom for living tissues in hadron therapy. PMMA is also of relevance for microelectronics in CMOS technologies and as a photoresist mask in electron beam lithography. We present a Monte Carlo code that, starting from a realistic description of the energy distribution of the electrons ejected by protons moving through PMMA, simulates the entire cascade of generated secondary electrons. By following in detail the motion of all these electrons, we find the radial distribution of the energy that they deposit in PMMA for several initial proton energies characteristic of the Bragg peak.

Keywords: Monte Carlo method, secondary electrons, energetic ions, ion-beam cancer therapy, ionization cross section, polymethylmethacrylate, proton beams, secondary electrons, radial energy distribution

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Authors: Sandy Black, Calum McLaughlin, Alessandro Pranzitelli, Marc Laing

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Multiphase flow structures of two-phase multicomponent fluids were experimentally investigated in a large diameter high-pressure pipeline up to 130 bar at TÜV SÜD’s National Engineering Laboratory Advanced Multiphase Facility. One of the main objectives of the experimental test campaign was to evaluate the impact of pressure on multiphase flow patterns as much of the existing information is based on low-pressure measurements. The experiments were performed in a horizontal and vertical orientation in both 4-inch and 6-inch pipework using nitrogen, ExxsolTM D140 oil, and a 6% aqueous solution of NaCl at incremental pressures from 10 bar to 130 bar. To visualise the detailed structure of the flow of the entire cross-section of the pipe, a fast response X-ray tomography system was used. A wide range of superficial velocities from 0.6 m/s to 24.0 m/s for gas and 0.04 m/s and 6.48 m/s for liquid was examined to evaluate different flow regimes. The results illustrated the suppression of instabilities between the gas and the liquid at the measurement location and that intermittent or slug flow was observed less frequently as the pressure was increased. CFD modellings of low and high-pressure simulations were able to successfully predict the likelihood of intermittent flow; however, further tuning is necessary to predict the slugging frequency. The dataset generated is unique as limited datasets exist above 100 bar and is of considerable value to multiphase flow specialists and numerical modellers.

Keywords: computational fluid dynamics, high pressure, multiphase, X-ray tomography

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Authors: Iyad A. A. Abusahloub

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This research aimed to measure the level of perception and application of Integrated Talent Management according to IBM standards, by the upper and middle categories in Palestinian government institutions in Gaza, using a descriptive-analytical method. Using a questionnaire based on the standards of the IBM Institute for Business Value, the researcher added a second section to measure the perception of integrated talent management, the sample was 248 managers. The SPSS package was used for statistical analysis. The results showed that government institutions in Gaza apply Integrated Talent Management according to IBM standards at a medium degree did not exceed 59.8%, there is weakness in the perception of integrated talent management at the level of 53.6%, and there is a strong correlation between (Integrated Talent Management) and (the perception of the integrated talent management) amounted to 92.9%, and 88.9% of the change in the perception of the integrated talent management is by (motivate and develop, deploy and manage, connect and enable, and transform and sustain) talents, and 11.1% is by other factors. Conclusion: This study concluded that the integrated talent management model presented by IBM with its six dimensions is an effective model to reach your awareness and understanding of talent management, especially that it must rely on at least four basic dimensions out of the six dimensions: 1- Stimulating and developing talent. 2- Organizing and managing talent. 3- Connecting with talent and empowering it. 4- Succession and sustainability of talent. Therefore, this study recommends the adoption of the integrated talent management model provided by IBM to any organization across the world, regardless of its specialization or size, to reach talent sustainability.

Keywords: HR, talent, talent management, IBM

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Authors: F. Sangiorgio, J. Silfwerbrand, G. Mancini

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Geometric and mechanical properties all influence the resistance of RC structures and may, in certain combination of property values, increase the risk of a brittle failure of the whole system. This paper presents a statistical and probabilistic investigation on the resistance of RC beams designed according to Eurocodes 2 and 8, and subjected to multiple failure modes, under both the natural variation of material properties and the uncertainty associated with cross-section and transverse reinforcement geometry. A full probabilistic model based on JCSS Probabilistic Model Code is derived. Different beams are studied through material nonlinear analysis via Monte Carlo simulations. The resistance model is consistent with Eurocode 2. Both a multivariate statistical evaluation and the data clustering analysis of outcomes are then performed. Results show that the ultimate load behaviour of RC beams subjected to flexural and shear failure modes seems to be mainly influenced by the combination of the mechanical properties of both longitudinal reinforcement and stirrups, and the tensile strength of concrete, of which the latter appears to affect the overall response of the system in a nonlinear way. The model uncertainty of the resistance model used in the analysis plays undoubtedly an important role in interpreting results.

Keywords: modelling, Monte Carlo simulations, probabilistic models, data clustering, reinforced concrete members, structural design

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Authors: Itziar Gonzalez, Pilar Carreras, Alberto Pinto, Roque Ruben Andres

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Acoustophoretic separation of plasma from blood is based on a collection process of the blood cells, driven by an acoustic radiation force. The number of cells, their concentration, and the sample hydrodynamics are involved in these processes. However, their influence on the acoustic blood response has not yet been reported in the literature. Addressing it, this paper presents an experimental study of blood samples exposed to ultrasonic standing waves at different hematocrit levels and hydrodynamic conditions. The experiments were performed in a glass capillary (700µm-square cross section) actuated by a piezoelectric ceramic at 1MHz, hosting 2D orthogonal half-wavelength resonances transverse to the channel length, with a single-pressure-node along its central axis where cells collected driven by the acoustic radiation force. Four blood dilutions in PBS of 1:20, 1:10, 1:5, and 1:2 were tested at eight flow rate conditions Q=0:120µL/min. The 1:5 dilution (H=9%) demonstrated to be optimal for the plasmapheresis at any of the flow rates analyzed, requiring the shortest times to achieve plasma free of cells. The study opens new possibilities to optimize processes of plasmapheresis processes by ultrasounds at different hematocrit conditions in future personalized diagnoses/treatments involving blood samples.

Keywords: ultrasounds, microfluidics, flow rate, acoustophoresis, polymeric resonators

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Authors: Mostafa Osman, Ata El-Kareim Shoeib

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The main objective of this paper is study the influence of carbon nano-tubes fibers and nano silica fibers on the characteristic compressive strength and flexural strength on concrete and cement mortar. Twelve tested specimens were tested with square section its dimensions (40*40*160) mm, divided into four groups. The first and second group studied the effect of carbon nano-tubes (CNTs) fiber with different percentage equal to 0.0, 0.11 %, 0.22 %, and 0.33 % by weight of cement and effect of nano-silica (nS) fibers with different percentages equal to 0.0, 1.0 %, 2.0 %, and 3.0 % by weight of cement on the cement mortar. The third and fourth groups studied the effect of CNTs fiber with different percentage equal to 0.0 %, 0.11 %, and 0.22 % by weight of cement, and effect of nS fibers with different percentages were equal to 0.0 %, 1.0%, and 2.0 % by weight of cement on the concrete. The compressive strength and flexural strength at 7, 28, and 90 days is determined. From analysis of tested results concluded that the nano-fiber is more effective when used with cement mortar than that of used with concrete because of increasing the surface area, decreasing the pore and the collection of nano-fiber. And also by adding nano-fiber the improvement of flexural strength of concrete and cement mortar is more than improvement of compressive strength.

Keywords: carbon nano-tubes (CNTs) fibres, nano-silica (nS) fibres, compressive strength, flexural strength

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Authors: O. M. Bamigbola, A. A. Ibrahim

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Analysis of real life problems often results in linear systems of equations for which solutions are sought. The method to employ depends, to some extent, on the properties of the coefficient matrix. It is not always feasible to solve linear systems of equations by direct methods, as such the need to use an iterative method becomes imperative. Before an iterative method can be employed to solve a linear system of equations there must be a guaranty that the process of solution will converge. This guaranty, which must be determined a priori, involve the use of some criterion expressible in terms of the entries of the coefficient matrix. It is, therefore, logical that the convergence criterion should depend implicitly on the algebraic structure of such a method. However, in deference to this view is the practice of conducting convergence analysis for Gauss-Seidel iteration on a criterion formulated based on the algebraic structure of Jacobi iteration. To remedy this anomaly, the Gauss-Seidel iteration was studied for its algebraic structure and contrary to the usual assumption, it was discovered that some property of the iteration matrix of Gauss-Seidel method is only diagonally dominant in its first row while the other rows do not satisfy diagonal dominance. With the aid of this structure we herein fashion out an improved version of Gauss-Seidel iteration with the prospect of enhancing convergence and robustness of the method. A numerical section is included to demonstrate the validity of the theoretical results obtained for the improved Gauss-Seidel method.

Keywords: linear algebraic system, Gauss-Seidel iteration, algebraic structure, convergence

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Authors: Bharat Kumar, Deepak Kumar, Vijay Chaudhry

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Zirconium alloys exhibit low neutron absorption cross-section and excellent mechanical properties. Due to these unique characteristics, these materials are widely used in designing core components of pressurized heavy water reactors (PHWRs). Another material that is widely used in the design of reactor core is stainless steel. Under operating conditions of the reactor, there are possibilities for mechanical and tribological interaction between the components made of zirconium alloy (Zr-2.5 Nb) and stainless steel (SS-410). This may result in wear of the material. To study the tribological characteristics of Zr-2.5 Nb and SS-410, low amplitude reciprocating wear tests are conducted at room temperature and at high temperatures (260 degrees Celsius). The tests are conducted at frequencies ranging from 5 Hz to 25 Hz. The displacement amplitude is varied from 200 µm to 600 µm. The responses are recorded, analyzed and correlated with damage observed using scanning electron microscopy (SEM) and an optical profilometer. Energy dispersive spectroscopy (EDS) is used to study the damage mechanism prevailing at the contact interface. A higher coefficient of friction (COF) is observed at higher temperatures as compared to the one at room temperature. Tests carried out at high temperature reveals adhesive wear as the dominant mechanism resulting in significant material transfer.

Keywords: PHWRs, Zr-2.5Nb, SS-410, wear

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Authors: Houda Khaled, Fredj Chaabani, Frederic Boulvain

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The Aptian series in north-central Tunisia was studied in detail regarding to lithology, microfacies, and magnetic susceptibility to provide new insights into the paleoenvironmental evolution and sea level changes in the carbonate platform. The study series is about 350 meters thick, and it consists of fives sequences of limestones, separated by four levels of marlstones and marly limestones. Petrographic study leads to the definition of 11 microfacies which are successively recorded along the Serdj section into the outer ramp, mid-ramp, inner ramp and coastal facies associations. The magnetic susceptibility of all samples was measured and compared with the facies and microfacies. There is a clear link between facies and magnetic susceptibility; the distal facies show high values while the proximal areas show lower values. The magnetic susceptibility profile reflects stratigraphic variations in response to relative changes in sea level and input of detrital materials. During the Aptian, kaolinite/illite intensity ratios show high values possibly indicating a warming trend followed then by decreasing values that may indicate a cooling trend. During the Albian, this cooling trend is reverted into humid/warming.

Keywords: Aptian, mineralogy, petrology, Serdj massif

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Authors: Rabia Khalil

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The aim of the study is to find out the perception of early childhood education teacher‘s about the role and implementation of information communication technology in early childhood education. The main purpose of the study is to investigate the role of information and communication technology in early childhood education as perceived by early childhood education teachers. The objectives of the study were to identify the roles of ICT in today’s early years and the impacts of Information communication technology in early childhood education. This study is to find out the role of ICT at ECE level & how it will be useful for teachers to implement this technique for the development of student skills. This is a quantitative research in which a survey study was conducted. The Population of the study was the primary teachers of the public and private primary schools of Lahore. By using random sampling technique the sample consists of 300 teachers but only 260 respond from 52 primary schools of Lahore. In this research, questionnaire was developed for primary school teachers. The questionnaires were based on liker type scale which comprises of section of strongly agree to strongly disagree. Data were analyzed by using descriptive analysis. The data was arranged and then entered in computer, having the software package for social sciences (SPSS) version 15. The importance of this study is to find out the role of ICT at ECE level & how it will be useful for teachers to implement this technique for the development of student skills.

Keywords: ECE, ICT, PC, C AI

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Authors: Ionel D. Craiu, Mihai Nedelcu

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Thin-walled cylinders are often used by the offshore industry as columns of floating installations. Based on observed strains, the inverse Finite Element Method (iFEM) may rebuild the deformation of structures. Structural Health Monitoring uses this approach extensively. However, the number of in-situ strain gauges is what determines how accurate it is, and for shell structures with complicated deformation, this number can easily become too high for practical use. Any thin-walled beam member's complicated deformation can be modeled by the Generalized Beam Theory (GBT) as a linear combination of pre-specified cross-section deformation modes. GBT uses bar finite elements as opposed to shell finite elements. This paper proposes an iFEM/GBT formulation for the shape sensing of thin-walled cylinders based on these benefits. This method significantly reduces the number of strain gauges compared to using the traditional inverse-shell finite elements. Using numerical simulations, dent damage detection is achieved by comparing the strain distributions of the undamaged and damaged members. The effect of noise on strain measurements is also investigated.

Keywords: damage detection, generalized beam theory, inverse finite element method, shape sensing

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Authors: Ya-Ping Chang

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Starting from the early stages of pregnancy, parents begin to form hopes and dreams about the future of their child. They will think about the appearance and personality of their child and may even develop many expectations. The patient in this study experienced a successful pregnancy following multiple attempts at artificial insemination. However, due to arrested embryonic development, and based on the physician’s evaluation, a caesarean section was performed at week 25. However, the baby suffered from infections and subsequently died from multiple organ failures. This study collected and analyzed objective and subjective data through observation, interviews, recording, and interactions with the patient. The following nursing issues of the patient were identified: anxiety, anticipatory grief, and adjustment disorder. The psychology of caring as proposed in Watson’s theory was applied to address these nursing issues. Comprehensive and continuous care was provided to the patient on the basis of mutual trust and individual nursing guidelines in order to alleviate the patient’s anxiety, help her to cope with grief, and prepare her for the eventual death of her child. The author helped the patient to say goodbye to her child and accept the child’s death calmly, such that she had no regrets about the experience. This nursing experience may serve as a reference to nurses managing similar cases in the future.

Keywords: dying baby, mother, grief, Watson’s theory

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Authors: Zhenyu Yang, Qiunan Chen, Xiaocheng Huang

Abstract:

Reliable prediction of tunnel collapse remains a prominent challenge in the field of civil engineering. In this study, leveraging the nonlinear Hoek-Brown failure criterion and the upper-bound theorem, an analytical solution for the collapse surface of shallowly buried circular tunnels was derived, taking into account the coupled effects of surface loads and pore water pressures. Initially, surface loads and pore water pressures were introduced as external force factors, equating the energy dissipation rate to the external force, yielding our objective function. Subsequently, the variational method was employed for optimization, and the outcomes were juxtaposed with previous research findings. Furthermore, we utilized the deduced equation set to systematically analyze the influence of various rock mass parameters on collapse shape and extent. To validate our analytical solutions, a comparison with prior studies was executed. The corroboration underscored the efficacy of our proposed methodology, offering invaluable insights for collapse risk assessment in practical engineering applications.

Keywords: tunnel roof stability, analytical solution, hoek–brown failure criterion, limit analysis

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Authors: C. Lanzerstorfer

Abstract:

Liquid sprays of water are frequently used in air pollution control for gas cooling purposes and for gas cleaning. Twin-fluid nozzles with internal mixing are often used for these purposes because of the small size of the drops produced. In these nozzles the liquid is dispersed by compressed air or another pressurized gas. In high efficiency scrubbers for particle separation, several nozzles are operated in parallel because of the size of the cross section. In such scrubbers, the scrubbing water has to be re-circulated. Precipitation of some solid material can occur in the liquid circuit, caused by chemical reactions. When such precipitations are detached from the place of formation, they can partly or totally block the liquid flow to a nozzle. Due to the resulting unbalanced supply of the nozzles with water and gas, the efficiency of separation decreases. Thus, the nozzles have to be cleaned if a certain fraction of blockages is reached. The aim of this study was to provide a tool for continuously monitoring the status of the nozzles of a scrubber based on the available operation data (water flow, air flow, water pressure and air pressure). The difference between the air pressure and the water pressure is not well suited for this purpose, because the difference is quite small and therefore very exact calibration of the pressure measurement would be required. Therefore, an equation for the reference air flow of a nozzle at the actual water flow and operation pressure was derived. This flow can be compared with the actual air flow for assessment of the status of the nozzles.

Keywords: condition monitoring, dual flow nozzles, flow equation, operation data

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Authors: Leon Pan

Abstract:

The first programming course within post-secondary education has long been recognized as a challenging endeavor for both educators and students alike. Historically, these courses have exhibited high failure rates and a notable number of dropouts. Instructors often lament students' lack of effort in their coursework, and students often express frustration that the teaching methods employed are not effective. Drawing inspiration from the successful principles of Extreme Programming, this study introduces an approach—the Extremes-based teaching model — aimed at enhancing the teaching of introductory programming courses. To empirically determine the effectiveness of the model, a comparison was made between a section taught using the extreme-based model and another utilizing traditional teaching methods. Notably, the extreme-based teaching class required students to work collaboratively on projects while also demanding continuous assessment and performance enhancement within groups. This paper details the application of the extreme-based model within the post-secondary online classroom context and presents the compelling results that emphasize its effectiveness in advancing the teaching and learning experiences. The extreme-based model led to a significant increase of 13.46 points in the weighted total average and a commendable 10% reduction in the failure rate.

Keywords: extreme-based teaching model, innovative pedagogical methods, project-based learning, team-based learning

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Authors: Eda Orhun

Abstract:

This paper studies the IELTS exit scores of Emirati university students before graduation and specifically compares the IELTS exit performance of the English foundation program (FP) students to direct entry (DE) students. Direct entry (DE) students are the students who were able to directly start with the undergraduate program without the need to attend English foundation program courses as they were able to prove a sufficient level of English at the university admittance. The results clearly show that the gap that existed already between these two groups of students at the start does not seem to disappear at the end of university studies, as DE students’ IELTS exit scores are significantly higher compared to FP students. Further work of a regression analysis exhibits that GPA and CMATH scores do have a positive and significant effect on IELTS exit scores. In addition, while the College of Education students are found to have the lowest performance in every sub-section of the IELTS exam across colleges, students of the College of Humanities and Social Sciences and the College of Natural and Health Sciences seem to have the best reading skills. Another important determinant of IELTS exit scores is found to be the English level of students at inception. With these results, the study offers important policy implications regarding the public education system of the UAE and sheds light on the main roots of the problem.

Keywords: English proficiency, higher education, IELTS exit scores, English foundation program, United Arab Emirates

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Authors: M. T. Z. Butt, T. Ahmad, N. A. Siddiqui

Abstract:

Commercially SA 516 Grade 70 is frequently used for the manufacturing of pressure vessels, boilers and storage tanks etc. in fabrication industry. Heat input is the major parameter during welding that may bring significant changes in the microstructure as well as the mechanical properties. Different welding technique has different heat input rate per unit surface area. Materials with large thickness are dealt with different combination of welding techniques to achieve required mechanical properties. In the present research two schemes: Scheme 1: SMAW (Shielded Metal Arc Welding) & GTAW (Gas Tungsten Arc Welding) and Scheme 2: SMAW & SAW (Submerged Arc Welding) of hybrid welding techniques have been studied. The purpose of these schemes was to study hybrid welding effect on the microstructure and mechanical properties of the weldment, heat affected zone and base metal area. It is significant to note that the thickness of base plate was 12 mm, also welding conditions and parameters were set according to ASME Section IX. It was observed that two different hybrid welding techniques performed on two different plates demonstrated that the mechanical properties of both schemes are more or less similar. It means that the heat input, welding techniques and varying welding operating conditions & temperatures did not make any detrimental effect on the mechanical properties. Hence, the hybrid welding techniques mentioned in the present study are favorable to implicate for the industry using the plate thickness around 12 mm thick.

Keywords: grade 70, GTAW, hybrid welding, SAW, SMAW

Procedia PDF Downloads 324