Miracle-dz/UniFAR-FTUs huggingface dataset:
Analysis of the Flow Between the Impeller and Pump Casing Back Face for a Centrifugal Pump

Previous experimental investigations of an open faced impeller, low specific speed, centrifugal pump showed that increasing the clearance between the impeller and the pump casing back face decreased the axial thrust generated on the impeller. This is contrary to normal convention. It was also found that if the front clearance of the pump was maintained at a constant value, the efficiency of the pump was not affected by the changing back clearance when no balance holes were present. The pump performance did vary with back clearance when balance holes were present. These results were obtained by measuring pump casing pressure distributions by Hossain (2000). In order to determine the reasons for this axial thrust dependence upon back clearance, it is necessary to determine the flow field within this small region. It is very difficult to measure the fluid flow in the small back clearance so the entire pump was simulated with varying back clearances and with and without balance holes using CFD. The CFD results are compared to the pump housing pressure distributions and to analytical analyses of flow between simple rotating disks. The dependence of the flow inside the back clearance region of the centrifugal pump has been analyzed in terms of the gap size and balance hole size. The impeller used in the analyses and experiments includes a cutaway section on the impeller. The flow inside the gap was severely affected by the gap size and, as a consequence, the pressure distribution and the axial thrust.Copyright © 2009 by ASME
A Bibliometric Analysis of Electronic Commerce Research from 1996 to 2012

This study identified 19,831 publications to explore global trends of electronic commerce research during 1996-2012, based on all the subject categories of the SCIE and SSCI. A few significant global trends of EC research were revealed. First, proceedings papers and journal articles were the primary document types, contributing 12,200 and 6,707 publications respectively. Journal articles showed stable upward trends from 1996 to 2012. Second, the top three conferences contributed a 10.6% share of total proceedings papers and the top 20 journals published a 31.1% share of total journal articles. Third, “Computer Science Information Systems”, “Business” and “Computer Science Theory Methods” were the top three most popular subject categories.
The Roles of Shape and Size in the Pinch Effort of Screw Knobs

The most common body parts that sustain injuries at the workplace are the hands and fingers. In association to this, researchers have conducted various studies on grip span, forces, postures, contact area and strength. However, it appears that limited studies have been done on the design of screw knobs of ergonomic shapes and sizes for pinch grip activities. Thus, the aim of this study is to design, develop and assess screw knobs of ergonomic shapes and sizes for pinching activities. Several designs of screw knobs were designed and fabricated. The assessment of the knobs involved workers from a manufacturing firm. The ratings on the efforts to pinch and turn the knobs were collected using surveys and analyzed with reliability and descriptive and analyses. The results show that the workers mostly preferred using the small 5-lobes knob. However, the large ball knob was the least preferred knob to be used. The findings of this study can be used to create design guidelines on knob shapes and sizes to develop safer, more ergonomic and efficient knobs.
Frequency Analysis of Bridge Condition Explanatory Data Items for Customized Data Collection and Bridge Management

Understanding the relative importance of large number of potential explanatory data items possibly explaining bridge condition deteriorations will help bridge management agencies better allocate resources for data collection, and simplify the data analysis. Previous studies explored how various factors influence bridge deteriorations and prioritized them, but they either used data from one geographic region, or used one or two statistical methods for analyzing data from the United States. Using National Bridge Inventory data, this study presents a systematic statistical investigation to better understand how the relative importance of different explanatory data items vary across regions in the U.S. and bridge condition rating items. We observed substantial variations in the frequency generated for different rating items using data from different regions, while some items are consistently identified as important. Deck material related features of bridges are items not studied in-depth in previous studies while consistently identified as important data items in this research.
Force distribution at the hand/handle interface for grip and pull tasks

The purpose of this experiment was to investigate how surface pressure distribution at the hand/handle interface changes during gripping and pulling and to enhance understanding of coupling between hands and grasped objects. Two pressure-sensing arrays were wrapped around a 3.18 cm diameter cylindrical handle which was fixed to a six-axis load cell. Six male subjects grasped the fixed overhead instrumented handle and performed two exertion types: downward pull exertions of 30, 60, and 90 percent of their measured grip strength and a maximal isometric grip exertion. Consistent with previous studies, the greatest pressure was exerted on the distal segments of the phalanges and at the base of the thumb and palm during maximum isometric gripping. However, when pulling, pressure on the palm (underside of the handle) was negligible. Most pull pressure was distributed over the fingers unevenly in a bimodal distribution, with the greatest pressures occurring on the proximal side of the hand followed by the fingertips. This supports the hypothesis that friction acts through the soft tissues of the fingers and creates an increased normal force in the direction of proximal segments (i.e. “belt friction”). When the surface of the handle is lumped into 5 equal zones, the observed bimodal trend is lost, with the greatest average pressure observed at the top of the handle corresponding to the pull direction. This discrepancy highlights the importance of resolution when making conclusions about applied hand forces. Future research is needed to investigate pressures on handles of different size and surface friction to develop comprehensive models of hand/object coupling.
The influence of mechanical shock on the operation of electrostatically driven RF-MEMS switches

A closed-form relationship between the insertion loss, the externally applied mechanical shock and the RF signal voltage of a capacitive RF-MEMS shunt switch is derived. It is shown that, based on this relationship, the minimum required mechanical stiffness of the suspended structure can be calculated. This allows determination of the minimum electrostatic switching voltage in a given process flow. The results are illustrated for specifications regarding shock resistance of electronic equipment as set out in MIL-STD-883. Even under the least severe test conditions, the shocks can affect the insertion loss of RF-MEMS switches, and can provoke self-biasing. This paper gives guidelines to avoid such false operation modes. The method can also be extended to yield the sensitivity of RF-MEMS devices to harmonic vibrations.
Guidelines for Closing the Efficiency Gap between Hero Solar Cells and Roll‐To‐Roll Printed Modules

One of the biggest challenges for the commercialization of polymer-based and other printed photovoltaic (PV) technologies is to establish reliable up-scaling processes that minimize the efficiency losses occurring during the transition from record laboratory cells to roll-to-roll (R2R) printed PV modules. This article reviews the latest advances in reducing the efficiency gap between record solar cells and large-area organic PV modules. The major loss sources are identified for the most popular cell architectures and categorized into optical, electrical, and processing-related contributions. Their relative shares in the overall efficiency drop are quantified through optical and electrical simulations. Further potential sources of efficiency loss, such as the replacement of halogenated by green solvents for active layer processing, are also addressed. Finally, the effect of reduced efficiency gaps on the production costs of R2R printed modules is discussed, demonstrating that values as low as € 0.5 Wp−1 (the nominal power of a solar module/cell) can be achieved.
Low power CMOS level shifters by bootstrapping technique

A level shifter circuit using bootstrapped gate drive to minimise voltage swing is presented. Capacitors are used to maintain the voltage difference between the gates of pull-up PMOS and pull-down NMOS. The power saving over conventional level shifter is typically 50% for a 5 V input and 12 V output.
The Effect of Stimulus Duration and Inter-stimulus Interval on Cortical Responses in Infants

Cortical auditory evoked potentials (CAEP) were recorded from ten normal-hearing infants, aged 3 to 7 months, using the natural speech segments /m/ and /t/. The aim was to investigate the effect of selected stimulus durations and inter-stimulus intervals (ISIs) on infant responses. In the first experiment, various stimulus durations were used but the ISI was fixed. Results showed no significant difference in the latency of the first positive peak (P1) with changes in stimulus duration, but there was a minor increase in amplitude when duration increased from short to medium length. In the second experiment, medium length stimuli were presented with various ISIs. Results showed that as the ISI increased, P1 latency was constant but its amplitude increased non-linearly for /t/ only. It appears therefore, that for the selected speech stimuli there was no clear advantage in using stimulus durations beyond 35 ms and ISIs beyond 1125 ms in infant assessments.
Design of Stictionfree - Lower Pull in Voltage RF MEMS Switch Using Varying Section Cantilever Beam

A new varying section cantilever beam type RF MEMS switch has been proposed. The main advantage of this switch is that it is inherently stiction free and therefore enhances design flexibility. An analytical model developed using unit load approach for the spring constant of the proposed switch has been presented and it has been shown that the spring constant and therefore the pull in voltage (Vpi) can be considerably reduced with the proposed switch. Simulation studies conducted on two groups of devices clearly demonstrate that the pull in voltage can be reduced by 26% with ten sections. Comparision of the pull in voltage obtained in the simulation studies for devices with the theoretically estimated Vpi shows that the spring constant model presented in this paper accurately estimates the spring constant. The results of analytical studies also demonstrate that the new proposed cantilever beam can considerably reduce the pull in voltage.
Can Virtual Reality Be Used As A Gait Training Tool For Older Adults?

The objective of this study was to examine the effects of Virtual Reality (VR) habituation on the kinematic and gait variability changes in older adults. Sixteen healthy older adults participated in the study. The experiment consisted of walking session on a walkway, followed by walking on the treadmill with and without a head mounted display of a VR scene. Kinematic data were collected using a motion capture system. Additionally, a cyber-sickness questionnaire was administered to the participants during and after the experiment to evaluate motion sickness symptoms. Statistical analyses indicated an increased variability in stride length, stride velocity, and step width during the initial 5-10 min in the VR. Kinematic data indicated an increased ankle plantar flexion, knee flexion, and trunk flexion in the initial VR period. All parameters approximated normal treadmill walking within 20 min of VR walking. The cyber sickness scores indicated no presence of cyber sickness during or after the VR experiment. It was concluded that the habituation time in VR may have significant effect on gait behavior in older adults and therefore it should be considered while designing a VR locomotion training study.
Predicting Age in Aedes aegypti (Diptera: Culicidae) Females to Monitor Changes in Transmission Potential

Abstract Background: The Aedes aegypti mosquito is a vector of several viruses including dengue, chikungunya, zika, and yellow fever. Vector surveillance and control are the primary methods used for the control and prevention of disease transmission, however, there is an overreliance on measures of population abundance in surveillance programs as a trigger for initiating control activities. At the northern edge of Ae. aegypti’s geographic range, survival seems to be the factor limiting disease transmission. In this study, we sought to test the utility of using body size as an entomological index to surveil changes in the age structure of field collected, female Aedes aegypti. Methods: We collected female Ae. aegypti mosquitoes using BG sentinel traps in three cities at the northern edge of their geographic range. Collections took place during their active season over the course of three years. Female wing size was measured as an estimate of body size and reproductive status was characterized by examining ovary tracheation. Chronological age was determined by measuring transcript abundance of an age-dependent gene. These data were then combined with weather data from the estimated larval development period and adulthood (one week prior to capture). Two sources of weather data were tested to see which was more appropriate for evaluating impacts on mosquito physiology. All variables were then used to test models for predicting age via structural equation modeling. Results: We found that there was a bias in the body size of mosquitoes collected alive from the BG sentinel traps that favored large females. In comparing city-specific NOAA weather data and site-specific data from HOBO remote temperature and humidity loggers, we found that HOBO data was more tightly associated with body size. We found that body size itself was not associated with age. Of all the variables measured, we found that temperature during development, body size, and relative humidity in the one week prior to capture produced the strongest model for predicting age. The strength of models improved drastically when testing one city at a time, with Hermosillo having the strongest model for predicting age.Conclusions: Body size increased the strength of weather-based models for predicting variation in age. Importantly, we found that variability of the factors measured was greater within cities than between cities, meaning that age predictions must be made on a city by city basis. These results contribute to efforts to use weather forecasts to predict changes in the probability of disease transmission by mosquito vectors.
Switched transmission-line type Q-band 4-bit MMIC phase shifter using InGaAs pin diodes

A fully integrated Q-band 4-bit MMIC phase shifter with InGaAs pin diodes has been designed and fabricated. To achieve low insertion loss and good phase shifting characteristics at Q-band frequencies, topology based on a switched transmission line is employed using a thin-film microstrip line structure implemented in the MMIC fabrication process. The fabricated phase shifter has demonstrated good performance such as an insertion loss of less than 6.1 dB in the frequency range 46–49 GHz with a small intrinsic chip size of 2.48×0.87 mm. The results show the best insertion loss characteristic among the switched transmission-line type phase shifters reported at Ka- and Q-band frequencies.
Optimization and stability of a cable-in-conduit superconductor

The optimization process for strand number and diameter, cable void fraction, and Cu/NbTi-ratio of the cable-in-conduit conductor for the superconducting magnet system of the planned stellarator fusion experiment Wendelstein 7-X is presented. Main optimization criteria are stability and cable cooling requirements, taking into account transient disturbances and losses. A simple stability criterion regarding transient disturbances is used which is derived from cable compression experiments. The resulting data for the 16 kA, 6 T cable are: cable and strand diameter /spl ap/11.5 mm and /spl ap/0.57 mm, respectively, strand number /spl ap/250, void /spl ap/36%, and Cu/sc-ratio /spl ap/2.7.
Exploring information experience using social media during the 2011 Queensland Floods: a pilot study

Social media networks have emerged as a powerful tool in allowing collaboration and sharing of information during times of crisis (Axel Bruns, The Centre for Creative Industries Blog, comment posted January 19, 2011). The 2011 Queensland floods provided a unique opportunity to explore social media use during an emergency. This paper presents the findings of a pilot study that explored the information experiences of people using social media during the flooding of the Brisbane River. Analysis of data from four interviews supported the emergence of four categories of information experience. Examination of the categories revealed the way in which individuals experienced social media and the point of the flooding at which each category of experience occurred. Information regarding individuals’ use of social media has the potential to inform the development of social media platforms that can provide relevant and accessible information for the general public in the event of a natural disaster. Category 1: Monitoring information Category 2: Community and communication Category 3: Affirmation Category 4: Awareness
SiteDB: Marshalling people and resources available to CMS

In a collaboration the size of CMS (approx. 3000 users, and almost 100 computing centres of varying size) communication and accurate information about the sites it has access to is vital in co-ordinating the multitude of computing tasks required for smooth running. SiteDB is a tool developed by CMS to track sites available to the collaboration, the allocation to CMS of resources available at those sites and the associations between CMS members and the sites (as either a manager/operator of the site or a member of a group associated to the site). It is used to track the roles a person has for an associated site or group. SiteDB eases the coordination load for the operations teams by providing a consistent interface to manage communication with the people working at a site, by identifying who is responsible for a given task or service at a site and by offering a uniform interface to information on CMS contacts and sites. SiteDB provides api's and reports for other CMS tools to use to access the information it contains, for instance enabling CRAB to use "user friendly" names when black/white listing CE's, providing role based authentication and authorisation for other web based services and populating various troubleshooting squads in external ticketing systems in use daily by CMS Computing operations.
Study on Bus Assignment Algorithm for SOC Test

The main concern is over rising temperature during the testing of complex system-on-chip (SOC), this paper studies SOC wrapper and test access mechanism (TAM), and proposes an improved algorithm of TAM assignment under the constraints of temperature. The algorithm uses temperature superposition method and adds compression process. This algorithm can find the test structure that uses shorter test time.
Basic characteristics of Ar/N2 atmospheric pressure nonequilibrium microwave discharge plasma jets

To understand the mechanism of surface processing by atmospheric pressure nonequilibrium microwave discharge plasma jets of coaxial type without a resonator, we measured the vibrational and rotational temperatures in plasmas using optical emission spectroscopy. The plasma was excited by a microwave power supply, using a gas mixture of Ar and N2 as the plasma gas, and changing the flow rate of N2 gas. We also measured the change in the contact angle of a PET film before and after the plasma processing. It decreased as the plasma rotational temperature increased, indicating that the hydrophilicity of the PET surface was improved as the plasma rotational temperature became higher. © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
High Performance 785 nm Wavelength Super-Luminescent Diodes

High-performance 785 nm wavelength super-luminescent diodes (SLDs) with ring cavity were fabricated. The maximum output power of 100 mW was obtained in continuous wave (CW) mode under room temperature. The full width at half maximum (FWHM) of the emission spectrum was 24 nm.
OpenVSLAM

Visual simultaneous localization and mapping (VSLAM) systems are essential for augmented reality devices, autonomous control of robots and drones, etc. However, conventional open-source visual SLAM frameworks are not designed to be called as libraries from third-party programs. To overcome this situation, we have developed OpenVSLAM [1-3], a novel visual SLAM framework, and released it as open-source software under the 2-clause BSD license. OpenVSLAM was presented and won first place in ACM Multimedia 2019 Open Source Software Competition. In this article, we show examples of using OpenVSLAM and hope that this encourages and enables further use of OpenVSLAM in research and development.
High area rate reconnaissance (HARR) and mine reconnaissance/hunter (MR/H) exploratory development programs

This paper describes the sea mine countermeasures developmental context, technology goals, and progress to date of the two principal Office of Naval Research exploratory development programs addressing sea mine reconnaissance and minehunting technology development. The first of these programs, High Area Rate Reconnaissance, is developing toroidal volume search sonar technology, sidelooking sonar technology, and associated signal processing technologies (motion compensation, beamforming, and computer-aided detection and classification) for reconnaissance and hunting against volume mines and proud bottom mines from 21-inch diameter vehicles operating in deeper waters. The second of these programs, Amphibious Operation Area Mine Reconnaissance/Hunter, is developing a suite of sensor technologies (synthetic aperture sonar, ahead-looking sonar, superconducting magnetic field gradiometer, and electro-optic sensor) and associated signal processing technologies for reconnaissance and hunting against all mine types (including buried mines) in shallow water and very shallow water from 21-inch diameter vehicles. The technologies under development by these two programs must provide excellent capabilities for mine detection, mine classification, and discrimination against false targets.
A New Index for Steel Framed Roof Information Extraction Based on Remote Sensing

There are a great number of index methods used to extract impervious surface from satellite images. However, these indices are not robust enough to detect steel framed roof due to the diversity of impervious materials. The extraction of steel framed roof information by remote sensing technology is becoming increasingly important because of its environmental and socio-economic significance. A new index, Normalized Difference Steel framed roof Index (NDSI) is proposed to extract steel framed roof surface information from TM images. The NDSI was created based on its spectral characteristics of TM image and the steel framed roof information can be extracted fast by NDSI threshold method. Additionally, Shijiazhuang city, which has experienced rapid urbanization, was chosen as the study area. And the classification results show that the new index NDSI can effectively extract steel framed roof information with higher accuracy.