Search results for: short slabs
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2966

Search results for: short slabs

2876 Mechanism to Optimize Landing Distance in Order to Minimize Tyre Wear during Braking

Authors: H. V. H. De Soysa, N. D. Hiripitiya, H. S. U. Thrimavithana, B. R. Epitawala, K. A. D. D. Kuruppu, D. J. K. Lokupathirage

Abstract:

This research was based on developing a mechanism in order to optimize the landing distance. Short distance braking and long distance braking may cause several issues for the aircraft including tyre wearing. The worst case occurs with short distance landing. The issues related to short distance landing were identified after conducting interviews with pilots, aeronautical engineers and technicians. A model was constructed in order to optimize the landing distance. The device started to function at the point where the main wheels of the aircraft touchdown the runway. It was found that implementing this device to the aircraft benefits to optimize the landing distance. This could lead to rectifying several issues occurred due to improper braking distances.

Keywords: aircraft, mechanism, optimize landing distance, runway

Procedia PDF Downloads 288
2875 Short Term Distribution Load Forecasting Using Wavelet Transform and Artificial Neural Networks

Authors: S. Neelima, P. S. Subramanyam

Abstract:

The major tool for distribution planning is load forecasting, which is the anticipation of the load in advance. Artificial neural networks have found wide applications in load forecasting to obtain an efficient strategy for planning and management. In this paper, the application of neural networks to study the design of short term load forecasting (STLF) Systems was explored. Our work presents a pragmatic methodology for short term load forecasting (STLF) using proposed two-stage model of wavelet transform (WT) and artificial neural network (ANN). It is a two-stage prediction system which involves wavelet decomposition of input data at the first stage and the decomposed data with another input is trained using a separate neural network to forecast the load. The forecasted load is obtained by reconstruction of the decomposed data. The hybrid model has been trained and validated using load data from Telangana State Electricity Board.

Keywords: electrical distribution systems, wavelet transform (WT), short term load forecasting (STLF), artificial neural network (ANN)

Procedia PDF Downloads 398
2874 Dielectric Recovery Characteristics of High Voltage Gas Circuit Breakers Operating with CO₂ Mixture

Authors: Peng Lu, Branimir Radisavljevic, Martin Seeger, Daniel Over, Torsten Votteler, Bernardo Galletti

Abstract:

CO₂-based gas mixtures exhibit huge potential as the interruption medium for replacing SF₆ in high voltage switchgears. In this paper, the recovery characteristics of dielectric strength of CO₂-O₂ mixture in the post arc phase after the current zero are presented. As representative examples, the dielectric recovery curves under conditions of different gas filling pressures and short-circuit current amplitudes are presented. A series of dielectric recovery measurements suggests that the dielectric recovery rate is proportional to the mass flux of the blowing gas, and the dielectric strength recovers faster in the case of lower short circuit currents.

Keywords: CO₂ mixture, high voltage circuit breakers, dielectric recovery rate, short-circuit current, mass flux

Procedia PDF Downloads 166
2873 “A Built-In, Shockproof, Shit Detector”: Major Challenges and Peculiarities of Translating Ernest Hemingway’s Short Stories Into Georgian

Authors: Natia Kvachakidze

Abstract:

Translating fiction is a complicated and multidimensional issue. However, studying and analyzing literary translations is not less challenging. This becomes even more complex due to the existence of several alternative translations of one and the same literary work. However, this also makes the research process more interesting at the same time. The aim of the given work is to distinguish major obstacles and challenges translators come across while working on Ernest Hemingway’s short fiction, as well as to analyze certain peculiarities and characteristic features of some existing Georgian translations of the writer’s work (especially in the context of various alternative versions of some well-known short stories). Consequently, the focus is on studying how close these translations come to the form and the context of the original text in order to see if the linguistic and stylistic characteristics of the original author are preserved. Moreover, it is interesting not only to study the relevance of each translation to the original text but also to present a comparative analysis of some major peculiarities of the given translations, which are naturally characterized by certain strengths and weaknesses. The latter is at times inevitable, but in certain cases, there is room for improvement. The given work also attempts to humbly suggest certain ways of possible improvements of some translation inadequacies, as this can provide even more opportunities for deeper and detailed studies in the future.

Keywords: Hemingway, short fiction, translation, Georgian

Procedia PDF Downloads 59
2872 Long-Term Cohort of Patients with Beta Thalassemia; Prevailing Role of Serum Ferritin Levels in Hypocalcemia and Growth Retardation

Authors: Shervin Rashidinia, Sara Shahmoradi, Seyyed Shahin Eftekhari, Mohsen Talebizadeh, Mohammad Saleh Sadeghi

Abstract:

Background: Beta-thalassemia Major (BTM) is a kind of hereditary hemolytic anemia which depended on regular monthly blood transfusion. However, iron deposition into the organs leads to multi-organ damage. The present study is the first study which aimed to evaluate the average of five-years serum ferritin level and compared by the prevalence of short stature and hypocalcemia. Materials/Methods: A cross-sectional retrospective study which a total of 140 patients with beta-thalassemia who were referred to Qom Thalassemia Clinic between February 2011 and July 2016 were enrolled to be reviewed. The exclusion criteria were consisting of incomplete medical records, diagnosis less than 2-years-ago and the blood transfusion less than every 4 weeks. The data including age, gender, weight, height, age of initial blood transfusion, age of initial chelation therapy, ferritin, and calcium were collected and analysis by SPSS version 24. Results: A total of 140 patients were enrolled. Of them, 75 (53.4%) were female. The mean age of the patients was 13.4±4.6 years.The mean age of initial diagnosis was 20.2±7.4 months. Hypocalcemia and short stature were occurred in 41 (29.3%) and 37 (26.4%) patients, respectively. The mean five-years serum ferritin level was significantly higher in the patients with short stature and hypocalcemia (P<0.0001). However, rise in serum ferritin level significantly increases the risk of short-stature and hypocalcemia (1.0004- and 1.0029 fold, respectively). Conclusion: We demonstrated that prevalence of short stature and hypocalcemia were significantly higher in the BTM.However, ferritin significantly increases the risk of short stature and hypocalcemia.

Keywords: beta-thalassemia, ferritin, growth retardation, hypocalcemia

Procedia PDF Downloads 301
2871 Adaptation in Translation of 'Christmas Every Day' Short Story by William Dean Howells

Authors: Mohsine Khazrouni

Abstract:

The present study is an attempt to highlight the importance of adaptation in translation. To convey the message, the translator needs to take into account not only the text but also extra-linguistic factors such as the target audience. The present paper claims that adaptation is an unavoidable translation strategy when dealing with texts that are heavy with religious and cultural themes. The translation task becomes even more challenging when dealing with children’s literature as the audience are children whose comprehension, experience and world knowledge are limited. The study uses the Arabic translation of the short story ‘Christmas Every Day’ as a case study. The short story will be translated, and the pragmatic problems involved will be discussed. The focus will be on the issue of adaptation. i.e., the source text should be adapted to the target language audience`s social and cultural environment.

Keywords: pragmatic adaptation, Arabic translation, children's literature, equivalence

Procedia PDF Downloads 177
2870 Finite Element Modeling of Influence of Roll Form of Vertical Scale Breaker on Decreased Formation of Surface Defects during Roughing Hot Rolling

Authors: A. Pesin, D. Pustovoytov, M. Sverdlik

Abstract:

During production of rolled steel strips the quality of the surface of finished strips influences steel consumption considerably. The most critical areas for crack formation during rolling are lateral sides of slabs. Deformation behaviors of the slab edge in roughing rolling process were analyzed by the finite element method with Deform-3D. In this study our focus is the analysis of the influence of edger’s form on the possibility to decrease surface cracking during roughing hot rolling.

Keywords: roughing hot rolling, FEM, crack, bulging

Procedia PDF Downloads 357
2869 The Prevalence of Cardiovascular Diseases in World-Class Triathletes: An Internet-Based Study from 2006 to 2019

Authors: Lingxia Li, Frédéric Schnell, Shuzhe Ding, Solène Le Douairon Lahaye

Abstract:

Background: The prevalence of cardiovascular diseases (CVD) in different triathlon sports disciplines has not been determined. Purpose: The present study aimed to determine the prevalence of CVD in world-class triathletes according to their sex, sports disciplines (aquathlon, duathlon, triathlon…), and formats (short/medium, long, and ultra-long distance). Methods: Male and female elite athletes from eleven triathlon sport disciplines, ranked in the internationally yearly top 10 between 2006 and 2019, were included. The athlete’s name was associated in a Google search with selected key terms related to heart disease and/or cardiac abnormalities. The prevalence and the hazard function of the variation were calculated, and the differences were then compared. Results: From 1329 athletes (male 639, female 690), 13 cases of CVD (0.98%, 95% CI: [0.45-1.51]) were identified, and the mean age of their occurrence was 29±6 years. Although no sex differences were found in each sport discipline/format (p > 0.05), severe outcomes (sudden cardiac arrest/death and those who had to stop their sports practice) were only observed in males. Short-distance triathlon (5.08%, 95% CI: [1.12-9.05]) was more affected than other disciplines in short/medium, long, and ultra-long formats. The prevalence of CVD in athletes who participated in multi-type of sports disciplines (4.14%, 95% CI: [1.14-7.15]) was higher than in those who participated in one type (0.52%, 95% CI: [0.10-0.93]) (p = 0.0004). Conclusion: Athletes in short-distance triathlon were more affected than other disciplines in short/medium, long and ultra-long formats. Athletes who participate in short/medium distances and those who participate in multi-type of sports disciplines should be closely monitored regardless of sex.

Keywords: cardiovascular diseases, sudden cardiac death, triathlon sport disciplines, world-class athletes

Procedia PDF Downloads 114
2868 An Event Relationship Extraction Method Incorporating Deep Feedback Recurrent Neural Network and Bidirectional Long Short-Term Memory

Authors: Yin Yuanling

Abstract:

A Deep Feedback Recurrent Neural Network (DFRNN) and Bidirectional Long Short-Term Memory (BiLSTM) are designed to address the problem of low accuracy of traditional relationship extraction models. This method combines a deep feedback-based recurrent neural network (DFRNN) with a bi-directional long short-term memory (BiLSTM) approach. The method combines DFRNN, which extracts local features of text based on deep feedback recurrent mechanism, BiLSTM, which better extracts global features of text, and Self-Attention, which extracts semantic information. Experiments show that the method achieves an F1 value of 76.69% on the CEC dataset, which is 0.0652 better than the BiLSTM+Self-ATT model, thus optimizing the performance of the deep learning method in the event relationship extraction task.

Keywords: event relations, deep learning, DFRNN models, bi-directional long and short-term memory networks

Procedia PDF Downloads 100
2867 Driving in a Short Arm Plaster Cast Steer a Patient off Course: A Randomised, Controlled, Crossover Study

Authors: B. W. Kenny, D.Mansour, K. G. Mansour, J. Attia, B. Meads

Abstract:

There is currently insufficient evidence to make a conclusive statement about safety while immobilized in a short arm cast. There is a paucity of published literature on this topic. The purpose of this study is to specifically evaluate short arm casts and their effect on driving abilities, particularly steering and avoidance of obstacles. The ability to drive safely is extrapolated from this data. In this study, a randomised, controlled, crossover design was used to assess 30 subjects randomised into 2 groups. A Logitech force feedback steering column and simulated driving program with a standardised road course was used. Objective outcome measures were the number of times subjects drove off the track, the number of crashes, time to lap completion and subjective assessment on whether wearing a short arm plaster cast impeded their steering. Recruited subjects had no upper limb pathology. The side of the applied plaster cast was randomised. The mean lap completion time reduced with repetition, the difference being statistically significant. There was no significant difference in mean number of times subjects in casts drove off the track (3 with vs. 3.07 without casts), average number of crashes (1.27 vs 0.97). Steering ability was not reduced whilst a subject was immobilised in a short arm Plaster of Paris cast, despite subject’s own impressions that their steering was impeded. This may help guide doctors in their advice to patients regarding driving in these casts.

Keywords: upper limb, arm injury, plaster cast, splint, driving, automobile, bone fracture

Procedia PDF Downloads 211
2866 Fiber Orientation Measurements in Reinforced Thermoplastics

Authors: Ihsane Modhaffar

Abstract:

Fiber orientation is essential for the physical properties of composite materials. The theoretical parameters of a given reinforcement are usually known and widely used to predict the behavior of the material. In this work, we propose an image processing approach to estimate true principal directions and fiber orientation during injection molding processes of short fiber reinforced thermoplastics. Generally, a group of fibers are described in terms of probability distribution function or orientation tensor. Numerical techniques for the prediction of fiber orientation are also considered for concentrated situations. The flow was considered to be incompressible, and behave as Newtonian fluid containing suspensions of short-fibers. The governing equations, of this problem are: the continuity, the momentum and the energy. The obtained results were compared to available experimental findings. A good agreement between the numerical results and the experimental data was achieved.

Keywords: injection, composites, short-fiber reinforced thermoplastics, fiber orientation, incompressible fluid, numerical simulation

Procedia PDF Downloads 501
2865 Fast Short-Term Electrical Load Forecasting under High Meteorological Variability with a Multiple Equation Time Series Approach

Authors: Charline David, Alexandre Blondin Massé, Arnaud Zinflou

Abstract:

In 2016, Clements, Hurn, and Li proposed a multiple equation time series approach for the short-term load forecasting, reporting an average mean absolute percentage error (MAPE) of 1.36% on an 11-years dataset for the Queensland region in Australia. We present an adaptation of their model to the electrical power load consumption for the whole Quebec province in Canada. More precisely, we take into account two additional meteorological variables — cloudiness and wind speed — on top of temperature, as well as the use of multiple meteorological measurements taken at different locations on the territory. We also consider other minor improvements. Our final model shows an average MAPE score of 1:79% over an 8-years dataset.

Keywords: short-term load forecasting, special days, time series, multiple equations, parallelization, clustering

Procedia PDF Downloads 70
2864 Engineering Analysis for Fire Safety Using Computational Fluid Dynamic (CFD)

Authors: Munirajulu M, Srikanth Modem

Abstract:

A large cricket stadium with the capacity to accommodate several thousands of spectators has the seating arena consisting of a two-tier arrangement with an upper and a lower bowl and an intermediate concourse podium level for pedestrian movement to access the bowls. The uniqueness of the stadium is that spectators can have an unobstructed view from all around the podium towards the field of play. Upper and lower bowls are connected by stairs. The stairs landing is a precast slab supported by cantilevered steel beams. These steel beams are fixed to precast columns supporting the stadium structure. The stair slabs are precast concrete supported on a landing slab and cantilevered steel beams. During an event of a fire at podium level between two staircases, fire resistance of steel beams is very critical to life safety. If the steel beam loses its strength due to lack of fire resistance, it will be weak in supporting stair slabs and may lead to a hazard in evacuating occupants from the upper bowl to the lower bowl. In this study, to ascertain fire rating and life safety, a performance-based design using CFD analysis is used to evaluate the steel beams' fire resistance. A fire size of 3.5 MW (convective heat output of fire) with a wind speed of 2.57 m/s is considered for fire and smoke simulation. CFD results show that the smoke temperature near the staircase/ around the staircase does not exceed 1500 C for the fire duration considered. The surface temperature of cantilevered steel beams is found to be less than or equal to 1500 C. Since this temperature is much less than the critical failure temperature of steel (5200 C), it is concluded that the design of structural steel supports on the staircase is adequate and does not need additional fire protection such as fire-resistant coating. CFD analysis provided an engineering basis for the performance-based design of steel structural elements and an opportunity to optimize fire protection requirements. Thus, performance-based design using CFD modeling and simulation of fire and smoke is an innovative way to evaluate fire rating requirements, ascertain life safety and optimize the design with regard to fire protection on structural steel elements.

Keywords: fire resistance, life safety, performance-based design, CFD analysis

Procedia PDF Downloads 164
2863 Oleic Acid Enhances Hippocampal Synaptic Efficacy

Authors: Rema Vazhappilly, Tapas Das

Abstract:

Oleic acid is a cis unsaturated fatty acid and is known to be a partially essential fatty acid due to its limited endogenous synthesis during pregnancy and lactation. Previous studies have demonstrated the role of oleic acid in neuronal differentiation and brain phospholipid synthesis. These evidences indicate a major role for oleic acid in learning and memory. Interestingly, oleic acid has been shown to enhance hippocampal long term potentiation (LTP), the physiological correlate of long term synaptic plasticity. However the effect of oleic acid on short term synaptic plasticity has not been investigated. Short term potentiation (STP) is the physiological correlate of short term synaptic plasticity which is the key underlying molecular mechanism of short term memory and neuronal information processing. STP in the hippocampal CA1 region has been known to require the activation of N-methyl-D-aspartate receptors (NMDARs). The NMDAR dependent hippocampal STP as a potential mechanism for short term memory has been a subject of intense interest for the past few years. Therefore in the present study the effect of oleic acid on NMDAR dependent hippocampal STP was determined in mouse hippocampal slices (in vitro) using Multi-electrode array system. STP was induced by weak tetanic Stimulation (one train of 100 Hz stimulations for 0.1s) of the Schaffer collaterals of CA1 region of the hippocampus in slices treated with different concentrations of oleic acid in presence or absence of NMDAR antagonist D-AP5 (30 µM) . Oleic acid at 20 (mean increase in fEPSP amplitude = ~135 % Vs. Control = 100%; P<0.001) and 30 µM (mean increase in fEPSP amplitude = ~ 280% Vs. Control = 100%); P<0.001) significantly enhanced the STP following weak tetanic stimulation. Lower oleic acid concentrations at 10 µM did not modify the hippocampal STP induced by weak tetanic stimulation. The hippocampal STP induced by weak tetanic stimulation was completely blocked by the NMDA receptor antagonist D-AP5 (30µM) in both oleic acid and control treated hippocampal slices. This lead to the conclusion that the hippocampal STP elicited by weak tetanic stimulation and enhanced by oleic acid was NMDAR dependent. Together these findings suggest that oleic acid may enhance the short term memory and neuronal information processing through the modulation of NMDAR dependent hippocampal short-term synaptic plasticity. In conclusion this study suggests the possible role of oleic acid to prevent the short term memory loss and impaired neuronal function throughout development.

Keywords: oleic acid, short-term potentiation, memory, field excitatory post synaptic potentials, NMDA receptor

Procedia PDF Downloads 307
2862 Political Determinants of Sovereign Spread: The Great East-West Divide

Authors: Maruska Vizek, Josip Glaurdic, Marina Tkalec, Goran Vuksic

Abstract:

We empirically explore whether and how taxation affects bilateral real exchange rates in the euro area – relative unit labor costs and relative consumer price indices. We find that employers’ social security contributions and the value added tax changes have the expected effects put forward in the fiscal devaluation literature and simulations. Increases in employers’ contributions appreciate the relative unit labor costs in the short- and the long-run, while value added tax hike appreciates the relative consumer prices. Somewhat surprisingly, for personal income tax increases, we find a short-run depreciating impact on the relative unit labor costs, while increases in employees’ contributions depreciate both measures of real exchange rates in the short-run.

Keywords: sovereign bonds, European Union, developing countries, political determinants

Procedia PDF Downloads 275
2861 A Program Evaluation of TALMA Full-Year Fellowship Teacher Preparation

Authors: Emilee M. Cruz

Abstract:

Teachers take part in short-term teaching fellowships abroad, and their preparation before, during, and after the experience is critical to affecting teachers’ feelings of success in the international classroom. A program evaluation of the teacher preparation within TALMA: The Israel Program for Excellence in English (TALMA) full-year teaching fellowship was conducted. A questionnaire was developed that examined professional development, deliberate reflection, and cultural and language immersion offered before, during, and after the short-term experience. The evaluation also surveyed teachers’ feelings of preparedness for the Israeli classroom and any recommendations they had for future teacher preparation within the fellowship program. The review suggests the TALMA program includes integrated professional learning communities between fellows and Israeli co-teachers, more opportunities for immersive Hebrew language learning, a broader professional network with Israelis, and opportunities for guided discussion with the TALMA community continued participation in TALMA events and learning following the full-year fellowship. Similar short-term international programs should consider the findings in the design of their participation preparation programs. The review also offers direction for future program evaluation of short-term participant preparation, including the need for frequent response item updates to match current offerings and evaluation of participant feelings of preparedness before, during, and after the full-year fellowship.

Keywords: educational program evaluation, international teaching, short-term teaching, teacher beliefs, teaching fellowship, teacher preparation

Procedia PDF Downloads 149
2860 Real Interest Rates and Real Returns of Agricultural Commodities in the Context of Quantitative Easing

Authors: Wei Yao, Constantinos Alexiou

Abstract:

In the existing literature, many studies have focused on the implementation and effectiveness of quantitative easing (QE) since 2008, but only a few have evaluated QE’s effect on commodity prices. In this context, by following Frankel’s (1986) commodity price overshooting model, we study the dynamic covariation between the expected real interest rates and six agricultural commodities’ real returns over the period from 2000:1 to 2018 for the US economy. We use wavelet analysis to investigate the causal relationship and co-movement of time series data by calculating the coefficient of determination in different frequencies. We find that a) US unconventional monetary policy may cause more positive and significant covariation between the expected real interest rates and agricultural commodities’ real returns over the short horizons; b) a lead-lag relationship that runs from agricultural commodities’ real returns to the expected real short-term interest rates over the long horizons; and c) a lead-lag relationship from agricultural commodities’ real returns to the expected real long-term interest rates over short horizons. In the realm of monetary policy, we argue that QE may shift the negative relationship between most commodities’ real returns and the expected real interest rates to a positive one over a short horizon.

Keywords: QE, commodity price, interest rate, wavelet coherence

Procedia PDF Downloads 52
2859 A Short-Baseline Dual-Antenna BDS/MEMS-IMU Integrated Navigation System

Authors: Tijing Cai, Qimeng Xu, Daijin Zhou

Abstract:

This paper puts forward a short-baseline dual-antenna BDS/MEMS-IMU integrated navigation, constructs the carrier phase double difference model of BDS (BeiDou Navigation Satellite System), and presents a 2-position initial orientation method on BDS. The Extended Kalman-filter has been introduced for the integrated navigation system. The differences between MEMS-IMU and BDS position, velocity and carrier phase indications are used as measurements. To show the performance of the short-baseline dual-antenna BDS/MEMS-IMU integrated navigation system, the experiment results show that the position error is less than 1m, the pitch angle error and roll angle error are less than 0.1°, and the heading angle error is about 1°.

Keywords: MEMS-IMU (Micro-Electro-Mechanical System Inertial Measurement Unit), BDS (BeiDou Navigation Satellite System), dual-antenna, integrated navigation

Procedia PDF Downloads 165
2858 Problems in Lifelong Education Course in Information and Communication Technology

Authors: Hisham Md.Suhadi, Faaizah Shahbodin, Jamaluddin Hashim, Nurul Huda Mahsudi, Mahathir Mohd Sarjan

Abstract:

The study is the way to identify the problems that occur in organizing short courses lifelong learning in the information and communication technology (ICT) education which are faced by the lecturer and staff at the Mara Skill Institute and Industrial Training Institute in Pahang, Malaysia. The important aspects of these issues are classified to five which are selecting the courses administrative. Fifty lecturers and staff were selected as a respondent. The sample is selected by using the non-random sampling method purpose sampling. The questionnaire is used as a research instrument and divided into five main parts. All the data that gain from the questionnaire are analyzed by using the SPSS in term of mean, standard deviation and percentage. The findings showed that there are the problems occur in organizing the short course for lifelong learning in ICT education.

Keywords: lifelong Education, information and communication technology, short course, ICT education, courses administrative

Procedia PDF Downloads 419
2857 Cycle Number Estimation Method on Fatigue Crack Initiation Using Voronoi Tessellation and the Tanaka Mura Model

Authors: Mohammad Ridzwan Bin Abd Rahim, Siegfried Schmauder, Yupiter HP Manurung, Peter Binkele, Meor Iqram B. Meor Ahmad, Kiarash Dogahe

Abstract:

This paper deals with the short crack initiation of the material P91 under cyclic loading at two different temperatures, concluded with the estimation of the short crack initiation Wöhler (S/N) curve. An artificial but representative model microstructure was generated using Voronoi tessellation and the Finite Element Method, and the non-uniform stress distribution was calculated accordingly afterward. The number of cycles needed for crack initiation is estimated on the basis of the stress distribution in the model by applying the physically-based Tanaka-Mura model. Initial results show that the number of cycles to generate crack initiation is strongly correlated with temperature.

Keywords: short crack initiation, P91, Wöhler curve, Voronoi tessellation, Tanaka-Mura model

Procedia PDF Downloads 72
2856 Interface Engineering of Short- and Ultrashort Period W-Based Multilayers for Soft X-Rays

Authors: A. E. Yakshin, D. Ijpes, J. M. Sturm, I. A. Makhotkin, M. D. Ackermann

Abstract:

Applications like synchrotron optics, soft X-ray microscopy, X-ray astronomy, and wavelength dispersive X-ray fluorescence (WD-XRF) rely heavily on short- and ultra-short-period multilayer (ML) structures. In WD-XRF, ML serves as an analyzer crystal to disperse emission lines of light elements. The key requirement for the ML is to be highly reflective while also providing sufficient angular dispersion to resolve specific XRF lines. For these reasons, MLs with periods ranging from 1.0 to 2.5 nm are of great interest in this field. Due to the short period, the reflectance of such MLs is extremely sensitive to interface imperfections such as roughness and interdiffusion. Moreover, the thickness of the individual layers is only a few angstroms, which is close to the limit of materials to grow a continuous film. MLs with a period between 2.5 nm and 1.0 nm, combining tungsten (W) reflector with B₄C, Si, and Al spacers, were created and examined. These combinations show high theoretical reflectance in the full range from C-Kα (4.48nm) down to S-Kα (0.54nm). However, the formation of optically unfavorable compounds, intermixing, and interface roughness result in limited reflectance. A variety of techniques, including diffusion barriers, seed layers, and ion polishing for sputter-deposited MLs, were used to address these issues. Diffuse scattering measurements, photo-electron spectroscopy analysis, and X-ray reflectivity measurements showed a noticeable reduction of compound formation, intermixing, and interface roughness. This also resulted in a substantial increase in soft X-ray reflectance for W/Si, W/B4C, and W/Al MLs. In particular, the reflectivity of 1 nm period W/Si multilayers at the wavelength of 0.84 nm increased more than 3-fold – propelling forward the applicability of such multilayers for shorter wavelengths.

Keywords: interface engineering, reflectance, short period multilayer structures, x-ray optics

Procedia PDF Downloads 20
2855 Modeling Study of Short Fiber Orientation in Simple Injection Molding Processes

Authors: Ihsane Modhaffar, Kamal Gueraoui, Abouelkacem Qais, Abderrahmane Maaouni, Samir Men-La-Yakhaf, Hamid Eltourroug

Abstract:

The main objective of this paper is to develop a Computational Fluid Dynamics (CFD) model to simulate and characterize the fiber suspension in flow in rectangular cavities. The model is intended to describe the velocity profile and to predict the fiber orientation. The flow was considered to be incompressible, and behave as Newtonian fluid containing suspensions of short-fibers. The numerical model for determination of velocity profile and fiber orientation during mold-filling stage of injection molding process was solved using finite volume method. The governing equations of this problem are: the continuity, the momentum and the energy. The obtained results were compared to available experimental findings. A good agreement between the numerical results and the experimental data was achieved.

Keywords: injection, composites, short-fiber reinforced thermoplastics, fiber orientation, incompressible fluid, numerical simulation

Procedia PDF Downloads 439
2854 Stator Short-Circuits Fault Diagnosis in Induction Motors

Authors: K. Yahia, M. Sahraoui, A. Guettaf

Abstract:

This paper deals with the problem of stator faults diagnosis in induction motors. Using the discrete wavelet transform (DWT) for the current Park’s vector modulus (CPVM) analysis, the inter-turn short-circuit faults diagnosis can be achieved. This method is based on the decomposition of the CPVM signal, where wavelet approximation and detail coefficients of this signal have been extracted. The energy evaluation of a known bandwidth detail permits to define a fault severity factor (FSF). This method has been tested through the simulation of an induction motor using a mathematical model based on the winding-function approach. Simulation, as well as experimental results, show the effectiveness of the used method.

Keywords: induction motors (IMs), inter-turn short-circuits diagnosis, discrete wavelet transform (DWT), Current Park’s Vector Modulus (CPVM)

Procedia PDF Downloads 429
2853 Evaluation of the Accuracy of a ‘Two Question Screening Tool’ in the Detection of Intimate Partner Violence in a Primary Healthcare Setting in South Africa

Authors: A. Saimen, E. Armstrong, C. Manitshana

Abstract:

Intimate partner violence (IPV) has been recognised as a global human rights violation. It is universally under diagnosed and the institution of timeous multi-faceted interventions has been noted to benefit IPV victims. Currently, the concept of using a screening tool to detect IPV has not been widely explored in a primary healthcare setting in South Africa, and it was for this reason that this study has been undertaken. A systematic random sampling of 1 in 8 women over a period of 3 months was conducted prospectively at the OPD of a Level 1 Hospital. Participants were asked about their experience of IPV during the past 12 months. The WAST-short, a two-question tool, was used to screen patients for IPV. To verify the result of the screening, women were also asked the remaining questions from the WAST. Data was collected from 400 participants, with a response rate of 99.3%. The prevalence of IPV in the sample was 32%. The WAST-short was shown to have the following operating characteristics: sensitivity 45.2%, specificity 98%,positive predictive value 98%, negative predictive value 79%. The WAST-short lacks sufficient sensitivity and therefore is not an ideal screening tool for this setting. Improvement in the sensitivity of the WAST-short in this setting may be achieved by lowering the threshold for a positive result for IPV screening, and modification of the screening questions to better reflect IPV as understood by the local population.

Keywords: domestic violence, intimate partner violence, screening, screening tools

Procedia PDF Downloads 279
2852 Effects of the Visual and Auditory Stimuli with Emotional Content on Eyewitness Testimony

Authors: İrem Bulut, Mustafa Z. Söyük, Ertuğrul Yalçın, Simge Şişman-Bal

Abstract:

Eyewitness testimony is one of the most frequently used methods in criminal cases for the determination of crime and perpetrator. In the literature, the number of studies about the reliability of eyewitness testimony is increasing. The study aims to reveal the factors that affect the short-term and long-term visual memory performance of the participants in the event of an accident. In this context, the effect of the emotional content of the accident and the sounds during the accident on visual memory performance was investigated with eye-tracking. According to the results, the presence of visual and auditory stimuli with emotional content during the accident decreases the participants' both short-term and long-term recall performance. Moreover, the data obtained from the eye monitoring device showed that the participants had difficulty in answering even the questions they focused on at the time of the accident.

Keywords: eye tracking, eyewitness testimony, long-term recall, short-term recall, visual memory

Procedia PDF Downloads 128
2851 Using Short Narrative Film to Drive Healthcare Policy: A Case Study

Authors: T. L. Granzyk, S. Scarborough, J. DeCosmo

Abstract:

The use of health-related or medical narratives has gained increasing anecdotal and research-based support as a successful device for changing health behavior and outcomes. These narratives, in the form of oral storytelling, short films, and educational documentaries, for example, are most effective when including empathetic characters that transport viewers into the story and command both their attention and emotional response. This case study outlines how and why one large health system created a short narrative film for their internal Sepsis Awareness campaign, which told the dramatic story of a patient recovering from a missed sepsis diagnosis, leaving her a quad-amputee. Results include positive global anecdotal response to the film from healthcare professionals and patients, as well as use of the film to support legislation, ultimately passed in favor of the formation of Sepsis Awareness Workgroups in Maryland. Authors conclude that narrative films can be used successfully to initiate healthcare legislation and to increase internal and external awareness of health-related areas in need of greater improvement and support. As such, healthcare leaders and stakeholders would benefit from learning how to intentionally create, cultivate, and curate narratives from within their own health systems that elicit an empathetic response.

Keywords: healthcare policy, healthcare narratives, sepsis awareness, short films

Procedia PDF Downloads 76
2850 Surface Induced Alteration of Nanosized Amorphous Alumina

Authors: A. Katsman, L. Bloch, Y. Etinger, Y. Kauffmann, B. Pokroy

Abstract:

Various nanosized amorphous alumina thin films in the range of (2.4 - 63.1) nm were deposited onto amorphous carbon and amorphous Si3N4 membrane grids. Transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), X-ray photoelectron spectroscopy (XPS) and differential scanning calorimetry (DSC) techniques were used to probe the size effect on the short range order and the amorphous to crystalline phase transition temperature. It was found that the short-range order changes as a function of size: the fraction of tetrahedral Al sites is greater in thinner amorphous films. This result correlates with the change of amorphous alumina density with the film thickness demonstrated by the reflectivity experiments: the thinner amorphous films have the less density. These effects are discussed in terms of surface reconstruction of the amorphous alumina films. The average atomic binding energy in the thin film layer decreases with decease of the thickness, while the average O-Al interatomic distance increases. The reconstruction of amorphous alumina is induced by the surface reconstruction, and the short range order changes being dependent on the density. Decrease of the surface energy during reconstruction is the driving force of the alumina reconstruction (density change) followed by relaxation process (short range order change). The amorphous to crystalline phase transition temperature measured by DSC rises with the decrease in thickness from 997.6°C for 13.9 nm to 1020.4 °C for 2.7 nm thick. This effect was attributed to the different film densities: formation of nanovoids preceding and accompanying crystallization process influences the crystallization rate, and by these means, the temperature of crystallization peak.

Keywords: amorphous alumina, density, short range order, size effect

Procedia PDF Downloads 436
2849 Effect of Cumulative Dissipated Energy on Short-Term and Long-Term Outcomes after Uncomplicated Cataract Surgery

Authors: Palaniraj Rama Raj, Himeesh Kumar, Paul Adler

Abstract:

Purpose: To investigate the effect of ultrasound energy, expressed as cumulative dissipated energy (CDE), on short and long-term outcomes after uncomplicated cataract surgery by phacoemulsification. Methods: In this single-surgeon, two-center retrospective study, non-glaucomatous participants who underwent uncomplicated cataract surgery were investigated. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were measured at 3 separate time points: pre-operative, Day 1 and ≥1 month. Anterior chamber (AC) inflammation and corneal odema (CO) were assessed at 2 separate time points: Pre-operative and Day 1. Short-term changes (Day 1) in BCVA, IOP, AC and CO and long-term changes (≥1 month) in BCVA and IOP were evaluated as a function of CDE using a multivariate multiple linear regression model, adjusting for age, gender, cataract type and grade, preoperative IOP, preoperative BCVA and duration of long-term follow-up. Results: 110 eyes from 97 non-glaucomatous participants were analysed. 60 (54.55%) were female and 50 (45.45%) were male. The mean (±SD) age was 73.40 (±10.96) years. Higher CDE counts were strongly associated with higher grades of sclerotic nuclear cataracts (p <0.001) and posterior subcapsular cataracts (p <0.036). There was no significant association between CDE counts and cortical cataracts. CDE counts also had a positive correlation with Day 1 CO (p <0.001). There was no correlation between CDE counts and Day 1 AC inflammation. Short-term and long-term changes in post-operative IOP did not demonstrate significant associations with CDE counts (all p >0.05). Though there was no significant correlation between CDE counts and short-term changes in BCVA, higher CDE counts were strongly associated with greater improvements in long-term BCVA (p = 0.011). Conclusion: Though higher CDE counts were strongly associated with higher grades of Day 1 postoperative CO, there appeared to be no detriment to long-term BCVA. Correspondingly, the strong positive correlation between CDE counts and long-term BCVA was likely reflective of the greater severity of underlying cataract type and grade. CDE counts were not associated with short-term or long-term postoperative changes in IOP.

Keywords: cataract surgery, phacoemulsification, cumulative dissipated energy, CDE, surgical outcomes

Procedia PDF Downloads 152
2848 Income-Consumption Relationships in Pakistan (1980-2011): A Cointegration Approach

Authors: Himayatullah Khan, Alena Fedorova

Abstract:

The present paper analyses the income-consumption relationships in Pakistan using annual time series data from 1980-81 to 2010-1. The paper uses the Augmented Dickey-Fuller test to check the unit root and stationarity in these two time series. The paper finds that the two time series are nonstationary but stationary at their first difference levels. The Augmented Engle-Granger test and the Cointegrating Regression Durbin-Watson test imply that the two time series of consumption and income are cointegrated and that long-run marginal propensity to consume is 0.88 which is given by the estimated (static) equilibrium relation. The paper also used the error correction mechanism to find out to model dynamic relationship. The purpose of the ECM is to indicate the speed of adjustment from the short-run equilibrium to the long-run equilibrium state. The results show that MPC is equal to 0.93 and is highly significant. The coefficient of Engle-Granger residuals is negative but insignificant. Statistically, the equilibrium error term is zero, which suggests that consumption adjusts to changes in GDP in the same period. The short-run changes in GDP have a positive impact on short-run changes in consumption. The paper concludes that we may interpret 0.93 as the short-run MPC. The pair-wise Granger Causality test shows that both GDP and consumption Granger cause each other.

Keywords: cointegrating regression, Augmented Dickey Fuller test, Augmented Engle-Granger test, Granger causality, error correction mechanism

Procedia PDF Downloads 388
2847 Effect of Hollow and Solid Recycled-Poly Fibers on the Mechanical and Morphological Properties of Short-Fiber-Reinforced Polypropylene Composites

Authors: S. Kerakra, S. Bouhelal, M. Poncot

Abstract:

The aim of this study is to give a comprehensive overview of the effect of short hollow and solid recycled polyethylene terephthalate (PET) fibers in different breaking tenacities reinforced isotactic polypropylene (iPP) composites on the mechanical and morphological properties. Composites of iPP/3, 7and 10 wt% of solid and hollow recycled PET fibers were prepared by batched melt mixing in a Brabender. The incorporation of solid recycled-PET fibers in isotactic polypropylene increase Young’s modulus of iPP relatively, meanwhile it increased proportionally with hollow fibers content. An improvement of the storage modulus, and a shift up in glass transition temperatures of hollow fibers/iPP composites was determined by DMA results. The morphology of composites was determined by scanning electron microscope (SEM) and optical polarized microscopy (OM) showing a good dispersion of the hollow fibers. Also, their flexible aspect (folding, bending) was observed. But, one weak interaction between the polymer/fibers phases was shown. Polymers can be effectively reinforced with short hollow recycled PET fibers due to their characteristics like recyclability, lightweight and the flexible aspect, which allows the absorbance of the energy of a striker with a minimum damage of the matrix. Aiming to improve the affinity matrix–recycled hollow PET fibers, it is suggested the addition of compatibilizers, as maleic anhydride.

Keywords: isotactic polypropylene, hollow recycled PET fibers, solid recycled-PET fibers, composites, short fiber, scanning electron microscope

Procedia PDF Downloads 249