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Study on a loop heat pipe for a long-distance heat transport under anti-gravity condition

This paper reports the test results and evaluation of gravity effects on long-distance loop heat pipe (LLHP) with 10m distances for heat transport. First, the LLHP was designed based on the one-dimensional steady-state model, fabricated and tested. Test results showed the LLHP could transport heat up to 340W for 10m and the thermal resistance between the evaporator and the condenser was 0.12K/W under horizontal condition. Next, the LLHP was tested in top-heat mode. The maximum heat transports were 310, 270, 220W and the thermal resistances were 0.15, 0.17, 0.22K/W under 30, 60, 100cm anti-gravity condition respectively. The heat transfer efficiency of the LLHP was discussed in detail. The evaluation results showed 71.4% of the 340W heat load was dissipated at the condenser under the horizontal condition. On the other hand, 62.8, 61.8, 57.1% of the maximum heat load was dissipated at the condenser under 30, 60, 100cm anti-gravity condition respectively. The calculation model was in good agreement with the experimental results by considering the existence of a vapor pocket between the evaporator case and the vapor-liquid interface. This analysis indicated the vapor blanket generates easily and becomes thicker as anti-gravity effect increases.

Test-beam and laboratory characterisation of the TORCH prototype detector

The TORCH time-of-flight (TOF) detector is being developed to provide particle identification up to a momentum of 10GeV/c over a flight distance of 10m. It has a DIRC-like construction with 10mm thick synthetic amorphous fused-silica plates as a Cherenkov radiator. Photons propagate by total internal reflection to the plate periphery where they are focused onto an array of customised position-sensitive micro-channel plate (MCP) detectors. The goal is to achieve a 15ps time-of-flight resolution per incident particle by combining arrival times from multiple photons. The MCPs have pixels of effective size 0.4mm×6.6mm2 in the vertical and horizontal directions, respectively, by incorporating a novel charge-sharing technique to improve the spatial resolution to better than the pitch of the readout anodes. Prototype photon detectors and readout electronics have been tested and calibrated in the laboratory. Preliminary results from testbeam measurements of a prototype TORCH detector are also presented.

Trace Elemental Characterization of Chalk Dust and Their Associated Health Risk Assessment.

It is evident that chalk produces dust on use, i.e., particulate matter, which will alter the air quality of classrooms and can cause health hazards in teachers. The possible causes for health effects of chalk dust on teachers are still unclear. Hence, the aim of this study is to estimate the concentration of trace elements (Al, Cr, Mn, Fe, Co, Ni, Si, Pb) in chalk dust collected from classrooms by using ICP-MS. Both suspended and settled chalk dust was collected from selected classrooms. Suspended chalk dust was collected with PM2.5 filter paper using fine dust sampler, and settled chalk dust was collected by placing petriplates at a distance of 3m from the board for a duration period of 30min. Scanning electron microscopy images of chalk dust were taken up. Potential health risk analysis was also assessed. Results showed that Al, Fe, and Mn are in higher concentration (>1000μgkg-1) in both settled and suspended chalk dust. Cr, Mn, Fe, Co, and Ni were beyond the minimal risk levels in both settled and suspended chalk dust. There are no minimal risk levels for the elements Al, Si, and Pb. The concentration of trace elements in suspended chalk dust was higher than that in settled chalk dust. The SEM images of PM2.5 filter papers (suspended chalk dust) showed that all pores of the sampled filter papers are clogged with chalk dust. The few SEM images of the settled chalk dust showed fibrous shape which is associated with good-quality chalk whereas others showed circular and more aggregated nature of chalk dust from low-quality chalk from which the dust production will be very high. As observed from the result that the trace elements concentration was high in the suspended chalk dust, the fact can be correlated with the SEM images which have shown high density of absorbed chalk dust. With reference to human health risk, dermal exposure was the main route of exposure followed by inhalation and ingestion. Al (aluminum), Fe (iron), Si (silicon), and Mn (manganese) are the major contributors for the non-carcinogenic effects. For all the elements, the carcinogenic effect calculated (LADD) is within the global acceptable limit (10-6-10-4).

Effects of riparian zone buffer widths on vegetation diversity in southern Appalachian headwater catchments

In mountainous areas such as the southern Appalachians USA, riparian zones are difficult to define. Vegetation is a commonly used riparian indicator and plays a key role in protecting water resources, but adequate knowledge of floristic responses to riparian disturbances is lacking. Our objective was to quantify changes in stand-level floristic diversity of riparian plant communities before (2004) and two, three, and seven years after shelterwood harvest using highlead cable-yarding and with differing no-cut buffer widths of 0m, 10m, and 30m distance from the stream edge. An unharvested reference stand was also studied for comparison. We examined: (1) differences among treatment sites using a mixed linear model with repeated measures; (2) multivariate relationships between ground-layer species composition and environmental variables (soil water content, light transmittance, tree basal area, shrub density, and distance from stream) using nonmetric multidimensional scaling; and (3) changes in species composition over time using a multi-response permutation procedure. We hypothesized that vegetation responses (i.e., changes in density, species composition, and diversity across the hillslope) will be greatest on harvest sites with an intermediate buffer width (10-m buffer) compared to more extreme (0-m buffer) and less extreme (30-m buffer and no-harvest reference) disturbance intensities. Harvesting initially reduced overstory density and basal area by 83% and 65%, respectively, in the 0-m buffer site; reduced by 50% and 74% in the 10-m buffer site; and reduced by 45% and 29% in the 30-m buffer site. Both the 0-m and 10-m buffer sites showed increased incident light variability across the hillslope after harvesting; whereas, there was no change in the 30-m and reference sites over time. We found significant changes in midstory and ground-layer vegetation in response to harvesting with the greatest responses on the 10-m buffer site, supporting our hypotheses that responses will be greatest on sites with intermediate disturbance. Ground-layer species composition differed significantly over time in the 0-m buffer and 10-m buffer sites (both P<0.0001), but did not change in the 30-m buffer and reference sites (both P>0.100). Average compositional dissimilarity increased after seven years, indicating greater within-stand heterogeneity (species diversity) after harvesting. These vegetation recovery patterns provide useful information for evaluating management options in riparian zones in the southern Appalachians.

METHODICAL RECOMMENDATIONS ON MANAGING TACTICAL TRAINING OF SWIMMERS SPECIALIZING ON THE 100M DISTANCE COMPLEX SWIMMING

The system of management of a comlex swimming style at the distance of 100m was developed. The main components of the system: forecasting of results in complex swimming at the 100m distance (by the average results of four types of competitive swimming at the 100m distance); analysis of the ratio between the speed on individual segments in four types of competitive swimming among the highly skilled sportsmen (dolphin, freestyle, on the back, breaststroke) and among low-skilled sportsmen (with a different speed ratio sequence); calculation of indexes allowing to predict: 1) fi nal result according to the data about the start, sections, turns and the fi nish; 2) calculation of the model parameters of technical elements (start, sections, turns and finish) on the basis of the predicted result.

Normative data for distal line bisection and baking tray task.

Line bisection is one of the tests used to diagnose unilateral spatial neglect (USN). Despite its wide application, no procedure or norms were available for the distal variant when the task was performed at distance with a laser pointer. Furthermore, the baking tray task was an ecological test aimed at diagnosing USN in a more natural context. The aim of this study was to collect normative values for these two tests in an Italian population. We recruited a sample of 191 healthy subjects with ages ranging from 20 to 89years. They performed line bisection with a laser pointer on three different line lengths (1, 1.5, and 2m) at a distance of 3m. After this task, the subjects performed the baking tray task and a second repetition of line bisection to test the reliability of measurement. Multiple regression analysis revealed no significant effects of demographic variables on the performance of both tests. Normative cut-off values for the two tests were developed using non-parametric tolerance intervals. The results formed the basis for clinical use of these two tools for assessing lateralized performance of patients with brain injury and for diagnosing USN.

Diagnosis Method of Radiated Emission from Battery Management System for Electric Vehicle

Electromagnetic emission from EVs has an effect on board equipment and nearby vehicles in urban transportation. Moreover, the electromagnetic emission from BMS in EVs can exceed the CISPR 12 limits of radiated emission for EVs. The radiated electric fields average for an electric car (CISPR12) is measured in semi-anechoic chamber (SAC) at a distance of 10m to study the diagnosis method for EMI. An exclusion procedure for EMI from BMS is designed to determine the component responsible for emission peaks through far-field antenna testing for vehicle. BMS and instrument are responsible for the average radiated emission exceeded the limits for the testing EV. The near-field testing is used to diagnose the location of EMI. From measurements and analysis of EMI from clock, the clock oscillator is the key component responsible for narrowband emission, and power devices’ switching in DC-DC converter BMS is the key component responsible for broadband emission.

Physical demand of seven closed agility drills

The present study aimed to quantify the demand of seven generic, closed agility drills. Twenty males with experience in invasion sports volunteered to participate in this study. They performed seven, closed agility drills over a standardised 30-m distance. Physical demand measures of peak velocity, total foot contacts, peak impacts, completion time, and maximum heart rate were obtained via the use of wearable sensor technologies. A subjective rating of perceived exertion (RPE) was also obtained. All measures, with the exception of maximum heart rates and RPE were able to delineate drills in terms of physical and physiological demand. The findings of this study exemplify the differences in demand of agility-type movements. Drill demand was dictated by the type of agility movement initiated with the increase in repetitiveness of a given movement type also contributing to increased demand. Findings from this study suggest agility drills can be manipulated to vary physical and physiological demand. This allows for the optimal application of training principles such as overload, progression, and periodisation.

Performance Analysis of WiFi Hotspot Network in Nnamdi Azikiwe University Awka

This work centres on the study of campus wifi hotspot networks in Nigeria universities, using the Nnamdi Azikiwe University Awka as a case study. A Campus Wide Area Network (CWN) provides a means of communication and collaboration in data intensive environments. These are vital key factors to building a strong knowledge culture and facilitating collaborative research for any educational institution. Network stumbler (Wifi Network Analyzer) and Iperf were installed on different laptop computers in the respective Access Points (AP) while being monitored from a dedicated server running on Mikrotik and wireshark. This was used in collecting useful data needed for the characterisation of the UNIZIK wifi hotspot network in terms of Received signal strength index (RSSI), Data throughput and latency/network delay. The AP distance from user is carefully measured with a meter tape. Performance analysis carried out on this university wifi hotspots shows that the network offers a delay of 0.1545s by default that increases by a factor of 0.001s; a data throughput of 37.30Mbps that decreases by a factor of 0.25Mbps for any user added to the network. Also, that an RSSI of -35.438dBm was obtained at the AP base station which decreases by a factor of 0.4925dBm for any 1m distance away from the APand finally that a traditional hotspot networks based on IEEE 802.11 series lacks integrated intelligence for services convergence, QoS performance and in most cases suffers from interoperability problem

Long-range high-speed visible light communication system over 100-m outdoor transmission utilizing receiver diversity technology

Visible light communication (VLC) has no doubt become a promising candidate for future wireless communications due to the increasing trends in the usage of light-emitting diodes (LEDs). In addition to indoor high-speed wireless access and positioning applications, VLC usage in outdoor scenarios, such as vehicle networks and intelligent transportation systems, are also attracting significant interest. However, the complex outdoor environment and ambient noise are the key challenges for long-range high-speed VLC outdoor applications. To improve system performance and transmission distance, we propose to use receiver diversity technology in an outdoor VLC system. Maximal ratio combining–based receiver diversity technology is utilized in two receivers to achieve the maximal signal-to-noise ratio. A 400-Mb/s VLC transmission using a phosphor-based white LED and a 1-Gb/s wavelength division multiplexing VLC transmission using a red–green–blue LED are both successfully achieved over a 100-m outdoor distance with the bit error rate below the 7% forward error correction limit of 3.8×10−3. To the best of our knowledge, this is the highest data rate at 100-m outdoor VLC transmission ever achieved. The experimental results clearly prove the benefit and feasibility of receiver diversity technology for long-range high-speed outdoor VLC systems.

Geospatial variability of soil CO2–C exchange in the main terrestrial ecosystems of Keller Peninsula, Maritime Antarctica

Soils and vegetation play an important role in the carbon exchange in Maritime Antarctica but little is known on the spatial variability of carbon processes in Antarctic terrestrial environments. The objective of the current study was to investigate (i) the soil development and (ii) spatial variability of ecosystem respiration (ER), net ecosystem CO2 exchange (NEE), gross primary production (GPP), soil temperature (ST) and soil moisture (SM) under four distinct vegetation types and a bare soil in Keller Peninsula, King George Island, Maritime Antarctica, as follows: site 1: moss-turf community; site 2: moss-carpet community; site 3: phanerogamic antarctic community; site 4: moss-carpet community (predominantly colonized by Sanionia uncinata); site 5: bare soil. Soils were sampled at different layers. A regular 40-point (5×8 m) grid, with a minimum separation distance of 1m, was installed at each site to quantify the spatial variability of carbon exchange, soil moisture and temperature. Vegetation characteristics showed closer relation with soil development across the studied sites. ER reached 2.26μmolCO2m−2s−1 in site 3, where ST was higher (7.53°C). A greater sink effect was revealed in site 4 (net uptake of 1.54μmolCO2m−2s−1) associated with higher SM (0.32m3m−3). Spherical models were fitted to describe all experimental semivariograms. Results indicate that ST and SM are directly related to the spatial variability of CO2 exchange. Heterogeneous vegetation patches showed smaller range values. Overall, poorly drained terrestrial ecosystems act as CO2 sink. Conversely, where ER is more pronounced, they are associated with intense soil carbon mineralization. The formations of new ice-free areas, depending on the local soil drainage condition, have an important effect on CO2 exchange. With increasing ice/snow melting, and resulting widespread waterlogging, increasing CO2 sink in terrestrial ecosystems is expected for Maritime Antarctica.

Quantification and risks associated with bacterial aerosols near domestic greywater-treatment systems

Greywater (GW) reuse can alleviate water stress by lowering freshwater consumption. However, GW contains pathogens that may compromise public health. During the GW-treatment process, bioaerosols can be produced and may be hazardous to human health if inhaled, ingested, or come in contact with skin. Using air-particle monitoring, BioSampler®, and settle plates we sampled bioaerosols emitted from recirculating vertical flow constructed wetlands (RVFCW) – a domestic GW-treatment system. An array of pathogens and indicators were monitored using settle plates and by culturing the BioSampler® liquid. Further enumeration of viable pathogens in the BioSampler® liquid utilized a newer method combining the benefits of enrichment with molecular detection (MPN-qPCR). Additionally, quantitative microbial risk assessment (QMRA) was applied to assess risks of infection from a representative skin pathogen, Staphylococcus aureus.According to the settle-plate technique, low amounts (0–9.7×104CFUm−2h−1) of heterotrophic bacteria, Staphylococcus spp., Pseudomonas spp., Klebsiella pneumoniae, Enterococcus spp., and Escherichia coli were found to aerosolize up to 1m away from the GW systems. At the 5m distance amounts of these bacteria were not statistically different (p>0.05) from background concentrations tested over 50m away from the systems. Using the BioSampler®, no bacteria were detected before enrichment of the GW-aerosols. However, after enrichment, using an MPN-qPCR technique, viable indicators and pathogens were occasionally detected. Consequently, the QMRA results were below the critical disability-adjusted life year (DALY) safety limits, a measure of overall disease burden, for S. aureus under the tested exposure scenarios. Our study suggests that health risks from aerosolizing pathogens near RVFCW GW-treatment systems are likely low. This study also emphasizes the growing need for standardization of bioaerosol-evaluation techniques to provide more accurate quantification of small amounts of viable, aerosolized bacterial pathogens.

Analysis of floe velocity characteristics in small-scaled zone in offshore waters in the eastern coast of Liaodong Bay

Based on ice conditions and environmental data obtained through fixed-site monitoring in coastal waters in the eastern coast of Liaodong Bay in two winters from 2012 to 2014, we determined the statistical characteristics of floe velocity in local small-scaled zone in the nearshore waters and analyzed the influences of offshore distance, ocean current velocity, and wind velocity on floe velocity. Moreover, the relationship between instantaneous floe velocity direction and other two directions (wind direction and ocean current direction) was discussed. The dominant floe velocity direction in nearshore waters in the eastern coast of Liaodong Bay was NE–SW, which was parallel to the general coastline trend. Offshore distance showed a significant influence on floe velocity in nearshore waters. The floe velocity in the waters within the offshore distance of 100m was significantly restricted and generally below 45cm/s. The floe velocity in the waters beyond the offshore distance of 100m was not affected by coastline and showed the positive correlation with ocean current velocity and the insignificant correlation with wind velocity. Instantaneous floe velocity direction showed no significant correlation with wind direction or ocean current direction, displaying certain randomness. Because the study sea area in the paper is characterized by the typical artificial coastline, the study results can be applicable in the reasonable selection and determination of sea ice design conditions in nearshore projects.

Development of TORCH readout electronics for customised MCPs

The TORCH detector is being developed for low-momentum particle identification, combining time-of-flight and Cherenkov techniques to achieve charged particle pi/K/p separation up to 10 GeV/c over a flight distance of 10m. This requires a timing resolution of 70 ps for single photons. Based on an existing scalable design, production and testing of a TORCH readout system has been undertaken over the past year, and a novel customized Micro Channel Plate (MCP) photomultiplier device with 128-channels has been instrumented. This paper will report on the development of the readout system which is being used to measure time-of-flight in a test-beam, and its performance. We will also discuss the communication and data alignment between the TORCH system and the TimePix3 telescope in order to provide track reconstruction.

Factors affecting sound exposure from firing an SA80 high-velocity rifle

The effect of distance on the peak sound pressure level and sound exposure level from an SA80 rifle has been investigated. Sound pressure waveforms were measured in two directions from the gun: downrange, from 50m to 300m, and to the left-hand side, from 0.3m to 32m. Some additional measurements were made to the right of the gun. Measurements made downrange showed three distinct features of the waveform; the shock wave from the supersonic bullet, the reflection from the ground, and the muzzle blast. The time elapsed between the shock wave and the muzzle blast increased with increasing distance: 94ms for a distance of 50m, and 507ms for a distance of 300m. The highest peak sound level downrange from a single round was between 151dB(C) and 148dB(C) at distances from 50m to 300m, and varied little if at all with distance. To the left of the gun, the peak sound pressure level of 161dB(C) at 0.3m reduced to 128dB(C) at 32m. The peak sound pressure level was estimated to be 137dB(C) at a distance of approximately 20m to the left-hand side. Hearing protection must therefore be worn by anyone closer than 20m to a person firing. The peak sound pressure level was estimated to be 135dB(C) at a distance of approximately 25m and therefore hearing protection is recommended at distances of up to 25m. The sound exposure level of 98dB(A) at 20m indicated that an observer at this distance could hear about 1440 rounds without hearing protection before the noise exposure reached the upper exposure action value specified in the Control of Noise at Work Regulations 2005. Peak sound pressure levels were on average 2.4dB higher at the left ear compared with the right ear.

Spectroscopic gamma camera for use in high dose environments

We developed a pinhole gamma camera to measure distributions of radioactive material contaminants and to identify radionuclides in extraordinarily high dose regions (1000mSv/h). The developed gamma camera is characterized by: (1) tolerance for high dose rate environments; (2) high spatial and spectral resolution for identifying unknown contaminating sources; and (3) good usability for being carried on a robot and remotely controlled. These are achieved by using a compact pixelated detector module with CdTe semiconductors, efficient shielding, and a fine resolution pinhole collimator. The gamma camera weighs less than 100kg, and its field of view is an 8m square in the case of a distance of 10m and its image is divided into 256 (16×16) pixels. From the laboratory test, we found the energy resolution at the 662keV photopeak was 2.3% FWHM, which is enough to identify the radionuclides. We found that the count rate per background dose rate was 220cpsh/mSv and the maximum count rate was 300kcps, so the maximum dose rate of the environment where the gamma camera can be operated was calculated as 1400mSv/h. We investigated the reactor building of Unit 1 at the Fukushima Dai-ichi Nuclear Power Plant using the gamma camera and could identify the unknown contaminating source in the dose rate environment that was as high as 659mSv/h.

Changes in running mechanics over 100-m, 200-m and 400-m treadmill sprints

PurposeCompare alterations in running mechanics during maximal treadmill sprints of different distances. MethodsEleven physically active males performed short (100-m), medium (200-m) and long (400-m) running sprints on an instrumented treadmill. Continuous measurement of running kinetics/kinematics and spring-mass characteristics were recorded and values subsequently averaged over every 50-m distance intervals for comparison. ResultsCompared with the initial 50m, running velocity decreased (P<0.001) by 8±2%, 20±4% and 39±7% at the end of the 100, 200 and 400-m, respectively. All sprint distances (except for step length in the 100-m) induced significantly longer (P<0.05) contact times (+7±4%, +22±8% and +36±13%) and lower step lengths (−1±4%, −5±5% and −41±2%) and frequencies (−6±3%, −13±7% and −22±8%) at the end of the 100-m, 200-m and 400-m, respectively. Larger reductions in ground reaction forces occurred in horizontal versus vertical direction, with greater changes with increasing sprinting distance (P<0.05). Similarly, the magnitude of decrement in vertical stiffness increased with sprint distance (P<0.05), while leg stiffness decreases were smaller and limited to 200-m and 400-m runs. Overall, we observed earlier and larger alterations for the 400-m compared with other distances. ConclusionsThe magnitude of changes in running velocity and mechanics over short (100-m), medium (200-m) and long (400-m) treadmill sprints increases with sprint distance. The alterations in stride mechanics occur relatively earlier during the 400-m compared with the 100-m and 200-m runs.

Spatial Effects of Industrial Effluent on Soil Quality around the Textile Industrial Area of Bhaluka Upazila, Mymensingh

The study was carried out to investigate the spatial effects of industrial effluent on physico-chemical properties of soil around the textile industrial area of Bhaluka upazila, Mymensingh, from January to March, 2015. Total 15 soil samples were collected at 0m, 50m, 100m, 200m and 300m distances from the effluent discharging point. Soil texture, pH, electrical conductivity (EC), organic matter (OM), nitrogen (N), phosphorus (P), potassium (K), sulphur (S), sodium (Na) and heavy metal (lead, Pb and cadmium, Cd) content were investigated in this study. Soil pH, EC, OM and nutrient content of soil were higher at discharge point (at 0m) and lowest at 300m distance. The Pb content was maximum (36.9 ppm) at 0m and minimum (24.27 ppm) at 300m distance. The highest value (3.0 ppm) of Cd was observed at 0m and lowest value (2.8 ppm) was at 300m distance. All of the studied values were higher at the adjacent of industrial area and gradually decreased with distance.J. Environ. Sci. &amp; Natural Resources, 8(2): 79-82 2015

Standoff detection of explosives and buried landmines using fluorescent bacterial sensor cells

A standoff detection scheme for buried landmines and concealed explosive charges is presented. The detection procedure consists of the following: Live bacterial sensor strains, genetically engineered to produce a dose-dependent amount of green fluorescent protein (GFP) in the presence of explosives' vapors, are encapsulated and spread on the suspected area. The fluorescence produced by the bacteria in response to traces of the explosive material in their microenvironment is remotely detected by a phase-locked optoelectronic sampling system.This scheme enables fast direct access to a large minefield area, while obviating the need to endanger personnel and equipment. Moreover, the employment of phase locking detection efficiently isolates the bacterial sensors' fluorescent output from the background optical signals. This facilitates the application of bacterial sensors in an outdoor environment, where control of background illumination is not possible. Using this system, we demonstrate standoff detection of 2,4-DNT both in aqueous solution and when buried in soil, by sensor bacteria either in liquid culture or agar-immobilized, respectively, at a distance of 50m in a realistic optically noisy environment.

遠隔加熱装置を利用した構造物のアクティブサーモグラフィ検査システムの開発

This study focuses on active thermographic non-destructive testing using remote heating equipments. Inspection capability using two different heating systems were examined, one is halogen lamp with light collecting mirror and another is CO2 laser scanning system. Experimental results showed that defect in a concrete specimen located at 20-m distance from heater was detected by using the focused halogen lamp, and that defects in a CFRP specimen were detected in thermal images obtained after laser scanning heating. These results imply that inspection system with these heating equipments is effective to inspect objects located far from observers.