Miracle-dz/UniFAR-FTUs huggingface dataset:
Modelling of Railway Track and Vehicle/Track Interaction at High Frequencies

Abstract A review is presented of dynamic modelling of railway track and of the interaction of vehicle and track at frequencies which are sufficiently high for the track's dynamic behaviour to be significant. Since noise is one of the most important consequences of wheel/rail interaction at high frequencies, the maximum frequency of interest is about 5kHz: the limit of human hearing. The topic is reviewed both historically and in particular with reference to the application of modelling to the solution of practical problems. Good models of the rail, the sleeper and the wheelset are now available for the whole frequency range of interest. However, it is at present impossible to predict either the dynamic behaviour of the railpad and ballast or their long term behaviour. This is regarded as the most promising area for future research.
Improving performance of microwave AlGaAs/GaAs HBTs using novel SiN/sub x/ passivation process

We report on the development of a silicon-nitride passivation film and its application to heterojunction bipolar transistors (HBT). The electric characterization of the semi-insulating film shows excellent passivation properties with measured charge density on the order of 5/spl times/10/sup 10/ cm/sup -2/, lowest, to our knowledge, reported for GaAs. Applied to HBT structure the passivation reduces in more than 75% the extrinsic base surface recombination current guaranteeing transistor gain even at 10 nA collector current levels.
An updated review of intensive design weeks for architectural technology programmes

Architectural Technologists are uniquely positioned to deliver wholesome technological building solutions; solutions that address sustainability, economics, social and psychological requirements. The structure of the Architectural technology courses differs from institution to institution in the UK; however, at the core is the objective to prepare the students for the real challenge of the multi-disciplinary nature of the profession while in practice. The teaching, learning and assessment strategies employed in delivering the curricula are crucial for achieving this objective. In order to facilitate or improve the teaching and learning experience in Architectural Technology programmes, it is imperative to design and structure teaching in a manner that reflects what the students will experience after graduation. To achieve this real and active learning process, a hands-on approach to teaching (and learning) is required. The design block week is an intensive learning experience which aims to immerse students in a focussed, project-based environment where through collaborative working they are encouraged to explore unique solutions to design and technological problems. It has long been recognised that intensive block weeks offer advantages to enhance core competency in students as well as fine-tune soft skills. To further contribute to the pedagogical debate, this paper revisits the intensive design week as a tool for delivering experiential learning to students. It re-evaluates the design and delivery of an intensive design week programme, now in its third year. Using quantitative data derived from student feedback, it discusses whether this approach continues to be effective and makes recommendations.
Finanzas internacionales

El presente libro ofrece a los lectores una mirada amplia y detallada sobre el funcionamiento y las particularidades de las finanzas internacionales, de la constitución y manejo de las divisas como puente principal para los intercambios entre naciones. Además, explica la operatividad en los diferentes mercados, así como de los diversos mecanismos y opciones que existen en la actualidad para gestionar los riesgos en todos los niveles y evitar pérdidas y afectaciones a las organizaciones por el desconocimiento de estas dinámicas.
Wpływ czynników sektorowych na wyniki finansowe polskich spółek publicznych

Podstawowym celem opracowania jest dokonanie przeglądu kluczowych światowych badan w zakresie wplywu czynnikow oddzialujących na poziomie sektora na wyniki finansowe przedsiebiorstw wraz z przedstawieniem wynikow badan wlasnych w tym zakresie. Wykorzystano probe 85 polskich spolek publicznych, dane finansowe zostaly zebrane za lata 2005‒2007, wykorzystaną metodą byla analiza regresji wielorakiej. Wyniki badan światowych pokazują rozbiezne rezultaty – od bardzo duzego wplywu czynnikow sektorowych na wyniki finansowe przedsiebiorstw do ich niemal calkowitego braku. Wyniki przeprowadzonych przez Autora badan wskazują na nieznaczny udzial zmiennych sektorowych w wynikach finansowych spolek, przy znacznie wiekszym znaczeniu zmiennych oddzialujących na poziomie firmy.
Large-scale time-resolved digital particle image velocimetry (TR-DPIV) for measurement of high subsonic hot coaxial jet exhaust of a gas turbine engine

The development of a highly configurable triple digital particle image velocimetry (DPIV) system is described, which is capable of acquiring both continuous, statistically independent measurements at up to 14 Hz and time-resolved PIV data at MHz rates. The system was used at QinetiQ's Noise Test Facility (NTF) as part of the EU-funded CoJeN programme to obtain measurements from high subsonic (Mach ⩽ 0.9), hot (∼500 °C), large (1/10th) scale coaxial jet flows at a standoff distance of ∼1 m. High-resolution time-averaged velocity and turbulence data were obtained for complete coaxial engine exhaust plumes down to 4 m (20 jet diameters) from the nozzle exit in less than 1 h. In addition, the system allowed volumetric data to be obtained, enabling fast assessment of spatial alignment of nozzle configurations. Furthermore, novel six-frame time-series data-capture is demonstrated up to 330 kHz, used to calculate time–space correlations within the exhaust, allowing for study of spatio-temporal developments in the jet, associated with jet-noise production. The highly automated system provides synchronization triggers for simultaneous acquisition from different measurement systems (e.g. LDA) and is shown to be versatile, rugged, reliable and portable, operating remotely in a hostile environment. Data are presented for three operating conditions and two nozzle geometries, providing a database to be used to validate CFD models of coaxial jet flow.
Imaging impact of multilayer tuning in EUV masks, experimental validation

This paper reports on the experimental validation of adapting the multilayer periodicity of an EUV mask to mitigate pattern shifts at wafer level. This EUV specific pattern shift will eventually contribute to overlay budgets which continue to tighten with decreasing technology node. A good understanding of its manipulators, i.e., mask 3D effects, is paramount. By means of mask diffractometry and scanner exposures at numerical aperture of 0.33 the mask-induced pattern shift at wafer level is verified. These measurements are then correlated to rigorous simulations using a calibrated EUV mask stack model to accurately predict the imaging impact of multilayer tuning in EUV masks. A comprehensive interpretation of the mask 3D impact on pattern shift at wafer level will be presented based on simulated diffraction pupils supported by experimental verification at both mask and wafer level.
True carrier lifetime measurements of semiconductor lasers

Differential carrier lifetimes of semiconductor lasers are obtained directly from the device impedance measurements. This new technique gives accurate lifetimes down to low bias currents, at which correct lifetimes are an order of magnitude higher than those obtained by a commonly used optical technique. Correct lifetimes reconcile the results of early PL studies and suggest much higher carrier concentrations.
A Novel Zadoff-Chu Matrix Transform Precoded Interleaved-OFDMA Uplink System for 4G Cellular Systems: Peak to Average Power Ratio Performance

Abstract High Peak to Average Power Ratio (PAPR) is one of the major drawbacks in the Orthogonal Frequency Division Multiple Access (OFDMA) systems. In this paper, we present a novel Zadoff-Chu Matrix Transform (ZCMT) precoding based Interleaved-OFDMA uplink system with improved PAPR for the upcoming 4G cellular systems. The proposed system is based on the precoding of constellation symbols with ZCMT precoder in such a way that the system becomes Constant Envelope OFDMA (CE-OFDMA). The CE-OFDMA signal allows the Radio-Frequency (RF) high power amplifier to operate near its saturation levels, thus maximize the power efficiency. However, even 0 db PAPR or CE-OFDMA systems must contend with pulse shaping to keep out of band radiation low and to meet the transmission spectrum mask requirement. Hence, the PAPR is analyzed with Root Raised Cosine pulse shaping. Simulation results show that proposed system has better PAPR gain than the walsh-hadamard transform (WHT) precoded Interleaved-OFDMA uplink systems and the conventional Interleaved-OFDMA uplink systems.
Monitoring the junction temperature of an IGBT through direct measurement using a fiber Bragg grating

This paper proposes a new technique to monitor the junction temperature of an insulated gate bipolar transistor (IGBT) through direct measurement using an optical fiber sensor mounted on the chip structure. Some features of the sensor such as electromagnetic immunity, small size and fast response time allow the identification of temperature changes generated by the energy loss during device operation. In addition to the online monitoring of the junction temperature, results show the thermal characteristics of the IGBT, which can be used to develop an accurate model to simulate the heat generated during the device conduction and switching processes.
Experimental and Numerical Response of Arch Bridge Historic Masonry Under Eccentric Loading

This study contributes to the knowledge of the compressive behavior of brickwork used in railway bridges and shows how to incorporate this information in structural modeling. An experimental investigation is carried out on brickwork specimens made with old clay bricks and lime mortar to reproduce the original components and the arrangement of masonry arch bridges built in Italy at the end of the nineteenth century. The specimens are subjected to monotonic and cyclic displacement-controlled compression tests, under centered and eccentric loading. Based on experimental results, a beam model with fiber cross-section is used to describe the macroscopic behavior of brickwork, where the fiber constitutive relationship is estimated according to the concentric tests. Eccentric tests are finally simulated and the comparison between theoretical predictions and experimental results reveals the capability of the model to reproduce the global force-displacement and bending moment-curvature experimental behavior and it.
Laser light-section sensor automating the production of textile-reinforced composites

Due to their advanced weight-specific mechanical properties, the application of fibre-reinforced plastics (FRP) has been established as a key technology in several engineering areas. Textile-based reinforcement structures (Preform) in particular achieve a high structural integrity due to the multi-dimensional build-up of dry-fibre layers combined with 3D-sewing and further textile processes. The final composite parts provide enhanced damage tolerances through excellent crash-energy absorbing characteristics. For these reasons, structural parts (e.g. frame) will be integrated in next generation airplanes. However, many manufacturing processes for FRP are still involving manual production steps without integrated quality control. The non-automated production implies considerable process dispersion and a high rework rate. Before the final inspection there is no reliable information about the production status. This work sets metrology as the key to automation and thus an economically feasible production, applying a laser light-section sensor system (LLSS) to measure process quality and feed back the results to close control loops of the production system. The developed method derives 3D-measurements from height profiles acquired by the LLSS. To assure the textile's quality a full surface scan is conducted, detecting defects or misalignment by comparing the measurement results with a CAD model of the lay-up. The method focuses on signal processing of the height profiles to ensure a sub-pixel accuracy using a novel algorithm based on a non-linear least-square fitting to a set of sigmoid functions. To compare the measured surface points to the CAD model, material characteristics are incorporated into the method. This ensures that only the fibre layer of the textile's surface is included and gaps between the fibres or overlaying seams are neglected. Finally, determining the uncertainty in measurement according to the GUM-standard proofed the sensor system's accuracy. First tests under industrial conditions showed that applying this sensor after the drapery of each textile layer reduces the scrap quota by approximately 30%.
Transforming Caterpillars into Butterflies: The Role of Managerial Values and HR Systems in the Performance of Emergent Organizations - Executive Summary

Emerging firms are the foundation for economic growth in today’s business world, yet relatively little is known about the factors that contribute to the success or failure of developing organizations. This research study helps to address this broad question by examining the role that managerial values and practices play in the performance of high-tech start-ups. Using the resource-based and dynamic capability perspectives, this research project examines three critical factors that are likely to affect the performance of emerging firms: human resource policies and practices, an overarching philosophy of partnership, and an entrepreneurial orientation. Each of these is argued to produce a sustainable competitive advantage by providing firms with the ability to dynamically configure and reconfigure resource bundles. Results indicate that high performance work systems and partnership philosophy are positively associated with sales growth and innovation. Additional findings suggest that partnership and an entrepreneurial orientation both increase the likelihood of implementing high performance work systems. Finally, the results suggest that firms combining a greater utilization of high performance work systems with an entrepreneurial orientation achieve higher levels of sales growth.
On adopting quality orientation as an operations philosophy to improve business performance in banking services

Purpose – This paper seeks to study the impact of adopting quality orientation as a business operations philosophy to enhance a firm's performance. Specifically, it aims to identify various indicators that make up a quality orientation philosophy, and to research their role in improving business performance in the banking sector of the service industry.Design/methodology/approach – The paper surveyed retail banking firms for this study, and used path analysis and structure equation modeling (SEM) to develop the study model. This model was tested to develop the process by which quality orientation philosophy, if adopted, can impact a business's performance.Findings – Results indicate that specific indicators of quality orientation, when operationalized as a business philosophy, can enhance a banking firm's performance. This study also provides an insight for managers as to the process of adopting quality orientation philosophy in their businesses.Research limitations/implications – Research was conducted o.
Controlling copper corrosion in new construction by organic matter removal

A new elementary school with persistent elevated copper corrosion by‐product release evaluated pH increase, orthophosphate dosing, and granular activated carbon (GAC) treatment as potential corrosion control measures using bench‐scale experiments. Removal of natural organic matter (NOM) with temporary GAC treatment facilitated the formation of a copper scale with a permanently diminished (> 85%) solubility via an accelerated natural scale‐aging process. Increasing the pH and adding a high dose of orthophosphate were also effective for decreasing copper release but presented significant long‐term drawbacks, and their benefits were reversed if the treatments were discontinued. Temporary GAC treatment may be a holistically attractive option to reduce copper corrosion problems in new construction in certain waters with high levels of NOM.
DPOAE Changes in Young Children with Confirmed Hearing Loss Due to Ototoxicity

The aim of this study was to examine the pattern of changes in distortion product otoacoustic emissions (DPOAEs) in children with ototoxic hearing loss during chemotherapy. The participants included a control group of 15 normal hearing children (3-12 years) and an experimental group of 7 paediatric oncology patients (1-13 years). Participants were tested using pure tone audiometry (PTA), tympanometry, and DPOAEs (primaries 65/55 dB SPL). The results revealed no perfect match between PTA and DPOAE results with respect to frequency and pattern of decrease/increase of DPOAE amplitudes. Further analysis of DPOAEs in the experimental group revealed three main patterns of change: (1) Concurrent decreases in DPOAEs that matched pure tone threshold (PTT) changes at approximately the same frequencies; (2) DPOAE changes prior to PTT change, suggesting possible predictive power in DPOAE testing and (3) DPOAE and PTT changes not related in terms of test frequency and direction of change, noted in a patient with a high cumulative carboplatin dose.
Study of Seepage and Stability of Foundation Pit under Continuous Rainy Conditions

Based on unsaturated soil seepage and shear strength theory , to explore the pore pressure dissipation law , it has been analyzed seepage about slope of deep foundation pit in Xian , supporting by pile-anchor retaining structure under the condition of continuous rainy by MIDAS software . The simulation result shows a temporary saturated region would appear on the surface of slope in continuous rainy days , then soil water content increasing as the rainwater infiltrate into a deeper soil layer gradually . For the sake of different cohesion of different time , Combine moisture filed , coming from pore pressure field , with the functional relationship between water content and cohesion , of simulated with filed test dates . The influence law of continuous rainy is derived from stability analysis by strength reduction fem about slope safety factor and stress of retaining structure .
Mentoring Relationships for Women in Retailing: Prevalence, Perceived Importance, and Characteristics

This paper describes a study on the prevalence, perceived importance, and characteristics of mentoring relationships for women employed in middle and upper level retail positions in the southwestern region of the United States. Survey questionnaires were mailed to 466 female executives employed by specialty, department, or discount store retailers; 205 (44%) were returned and usable. Results of this study indicated that mentored mid-level executives reported more promotions over a five-year period than nonmentored executives and that upper level executives were more likely to be mentored than mid-level executives. Upper level women experiencing mentoring relationships reported higher levels of job motivation than did their nonmentored counterparts. Study results also revealed that upper level executives were more likely to have been mentored by someone of the male gender than were the mid-level participants and were more likely to have been mentored by an older individual. The similarity in the relationship characteristics for middle and upper level executives suggests that upper level executives who had been mentored were serving this function for other females in the organization. The findings indicate that mentoring relationships can be an important force in the career development of women in retailing.
Seismic force demand on ductile reinforced concrete shear walls subjected to western North American ground motions: Part 1 — parametric study

A parametric study of regular ductile reinforced concrete (RC) cantilever walls designed with the 2010 National building code of Canada and the 2004 Canadian Standards Association (CSA) standard A23.3 for Vancouver is performed to investigate the influence of the following parameters on the higher mode amplification effects, and hence on the seismic force demand: number of storeys, fundamental lateral period (T), site class, wall aspect ratio, wall cross-section, and wall base flexural overstrength (γw). The study is based on inelastic time-history analyses performed with a multilayer beam model and a smeared membrane model accounting for inelastic shear–flexure–axial interaction. The main conclusions are that (i) T and γw are the studied parameters affecting the most dynamic shear amplification and seismic force demand, (ii) the 2004 CSA standard A23.3 capacity design methods are inadequate, and (iii) a single plastic hinge design may be inadequate and unsafe for regular ductile RC walls with γw < 2.0.
A Systematic Review of Workplace Rehabilitation Interventions for Work-Related Low Back Pain

Abstract This article describes the process and outcome of a systematic review that evaluated the effectiveness of workplace rehabilitation interventions for work-related low back pain (LBP). Between 1982 and 2005 CINAHL, MEDLINE, EMBASE and AMED databases were searched for studies of interventions that were provided at the workplace for workers with LBP. Using methodological quality appraisal 5 reviewers scrutinised the articles. A total of 1224 articles were reviewed and 15 articles, consisting of 10 studies, were deemed of sufficient quality to be included. The best evidence was clinical interventions with occupational interventions, as well as early return to work/modified work interventions, were effective in returning workers to work earlier, reducing pain and disability, and decreasing the rate of back injuries. Ergonomic interventions were also found to be effective workplace interventions.
Biodiesel Feedstock and Blend Level Sensing Using Visible Light Spectra and Neural Network

Even after biodiesel meets ASTM D6751 specifications, biodiesels from different feedstocks may have different properties. Biodiesel blend level influences the fuel properties, such as cloud point and emissions. Therefore, whether for performance reasons or other reasons, it is often required to detect the biodiesel percentage in a diesel-biodiesel blend. This research used a spectrophotometer to scan the blends of U.S. No. 2 diesel and biodiesel from three different feedstocks (rapeseed, soybean. and mustard oil) in the visible wavelength range of 380-530 nm. It was found that the shape of the absorption curve varied according to biodiesel feedstock; however, relative absorbance was proportional to the blend level. If the absorbance of the parent biodiesel can be measured, such as in a blending facility, then a single wavelength between 470 and 490 nm could be used to measure the biodiesel blend level with ±1.85% standard error at 95% confidence interval. A neural network was trained to measure the blend level when the parent biodiesel spectrum was unknown. It was concluded that even if the absorption spectrum of the parent biodiesel is not known, the absorption spectrum of the blend from 380-530 nm can be used along with a neural network to detect the biodiesel feedstock and for rough blend level estimation.