Relationships between non-acoustic factors and subjective reactions to floor impact noise in apartment buildings

The aim of this study was to provide an understanding of how residents in apartment buildings perceive and react to impact sounds coming from the upstairs neighbours' dwellings. Based on existing theoretical and empirical studies on environmental noise, a conceptual model was developed to explain relationships among noise annoyance and non-acoustic factors. The model was then tested using structural equation modelling with survey data from residents living in apartment buildings (N = 487). The findings showed that the conceptual model was consistent with other models developed for environmental noises. The results indicated that annoyance induced by floor impact noise was associated with perceived disturbance, coping, and self-reported health complaints. Noise sensitivity had a direct impact on perceived disturbance and an indirect impact on annoyance, and moderating variables affected the non-acoustic factors. Exposure to footstep noises increased the impact size of noise sensitivity to disturbance. Predictability, marital status, and house ownership were found to influence the relationship between attitudes towards authorities and coping. In addition, a negative attitude towards neighbours (i.e., the noise source) moderated the positive relationship between annoyance and coping

2003, ‘An experimental study on the thermal conductivity change of building insulation materials with environmental condition and long-time elapse

Abstract It has been known that the thermal performance of building insulation materials is easily influenced by the environment's condition, and moreover the thermal performance of some insulation materials are changed dramatically with time elapse. So, during the life span of actual buildings, the thermal performance of envelope should not be maintained as the design intended. To keep thermal performance of buildings as the design intended, it is essential to know the performance change of insulation materials with time elapse and environmental condition changes. The objective of this paper is to provide the basic experimental data for thermal insulation performance change with environmental condition and time elapse. We tested the thermal conductivity of insulation materials used widely in Korean domestic buildings. We measured the change of thermal conductivity according to the moisture content rate, the variation of test temperature and the time elapse, etc. The test specimens were kept in actual weather condition, which was influenced directly by the outside environment for the long-time elapse test. The result of the study shows 1)the maximum moisture content rate of mineral fibre insulations is higher than others, 2)thermal conductivity rises as test temperature goes up, 3)the thermal conductivity of the extruding insulations and hardened urethane foam changes by maximum 50% with time elapse(2 years)

High-Performance Plasmonic THz Detector by Monolithic Integration of Asymmetric FET-Antenna in 65-nm CMOS Technology

In this paper, we report the high-performance plasmonic terahertz (THz) detector based on antenna-coupled asymmetric nano-CMOS structure. For maximizing performance enhancement by nano-CMOS technology, asymmetric MOSFET is newly designed on a self-aligned gate structure and verticallyintegrated patch antenna in 65-nm CMOS technology. Finally, we obtained the highly enhanced detection performance with responsivity (Rv) of 1.5 kV/W and noise-equivalent-power (NEP) of 15 pW/Hz0.5 at 0.2 THz

A multifunctional micro-fluidic system for dielectrophoretic concentration coupled with immuno-capture of low numbers of Listeria monocytogenes

In this study, we demonstrated a micro-fluidic system with multiple functions, including concentration of bacteria using dielectrophoresis (DEP) and selective capture using antibody recognition, resulting in a high capture efficiency of bacterial cells. The device consisted of an array of oxide covered interdigitated electrodes on a flat silicon substrate and a y16 mm high and y260 mm wide micro-channel within a PDMS cover. For selective capture of Listeria monocytogenes from the samples, the channel surface was functionalized with a biotinylated BSA– streptavidin–biotinylated monoclonal antibody sandwich structure. Positive DEP (at 20 Vpp and 1 MHz) was used to concentrate bacterial cells from the fluid flow. DEP could collect y90% of the cells in a continuous flow at a flow rate of 0.2 ml min21 into the micro-channel with concentration factors between 102–103, in sample volumes of 5–20 ml. A high flow rate of 0.6 ml min21 reduced the DEP capture efficiency to y65%. Positive DEP attracts cells to the edges of the electrodes where the field gradient is the highest. Cells concentrated by DEP were captured by the antibodies immobilized on the channel surface with efficiencies of 18 to 27% with bacterial cell numbers ranging from 101 to 103 cells. It was found that DEP operation in our experiments did not cause any irreversible damage to bacterial cells in terms of cell viability. In addition, increased antigen expression (antigens to C11E9 monoclonal antibody) on cell membranes was observed following the exposure to DEP

Performance enhancement of plasmonic sub-terahertz detector based on antenna integrated low-impedance silicon MOSFET

We demonstrate the performance enhancement of field-effect transistor (FET)-based plasmonic terahertz (THz) detector with monolithic integrated antenna in low-impedance regime and report the experimental results of Si MOSFET impedance in THz regime using 0.2-THz measurement system. By designing FET with low-impedance ranges (<1 k??) and integrating antennas with impedances of 50 and 100 ??, we found that our low-impedance MOSFETs have the input impedance criterion of 50 ?? at 0.2 THz and the MOSFETs with thinner gate oxide show the highly enhanced plasmonic photoresponses at 50-?? antenna by 325 times from the result of the detector without antennaclose1

High-Performance Plasmonic THz Detector Based on Asymmetric FET with Vertically Integrated Antenna in CMOS Technology

We report a high-performance plasmonic terahertz (THz) detector based on antenna-coupled asymmetric field-effect transistor (FET) structure using 65-nm CMOS technology. By designing asymmetric FET on a self-aligned poly-Si gate structure, more enhanced channel charge asymmetry between source and drain has been obtained in comparison with non-self-aligned metal gate structure of our previous work. In addition, using vertically-integrated patch antenna, which is designed for 0.2 THz resonance frequency, we demonstrated the highly enhanced detection performance with responsivity (Rv) of 1.5 kV/W and noise-equivalent-power (NEP) of 15 pW/Hz0.5 at 0.2 THz.clos

Electrical detection of germination of viable model Bacillus anthracis spores in microfluidic biochips

In this paper, we present a new impedance-based method to detect viable spores by electrically detecting their germination in real time within microfluidic biochips. We used Bacillus anthracis Sterne spores as the model organism. During germination, the spores release polar and ionic chemicals, such as dipicolinic acid (DPA), calcium ions, phosphate ions, and amino acids, which correspondingly increase the electrical conductivity of the medium in which the spores are suspended. We first present macro-scale measurements demonstrating that the germination of spores can be electrically detected at a concentration of 10(9) spores ml(-1) in sample volumes of 5 ml, by monitoring changes in the solution conductivity. Germination was induced by introducing an optimized germinant solution consisting of 10 mM L-alanine and 2 mM inosine. We then translated these results to a micro-fluidic biochip, which was a three-layer device: one layer of polydimethylsiloxane (PDMS) with valves, a second layer of PDMS with micro-fluidic channels and chambers, and the third layer with metal electrodes deposited on a pyrex substrate. Dielectrophoresis (DEP) was used to trap and concentrate the spores at the electrodes with greater than 90% efficiency, at a solution flow rate of 0.2 ml min(-1) with concentration factors between 107-109 spores ml(-1), from sample volumes of 1-5 mu l. The spores were captured by DEP in deionized water within 1 min (total volume used ranged from 0.02 ml to 0.2 ml), and then germinant solution was introduced to the flow stream. The detection sensitivity was demonstrated to be as low as about a hundred spores in 0.1 nl, which is equivalent to a macroscale detection limit of approximately 10(9) spores ml(-1). We believe that this is the first demonstration of this application in microfluidic and BioMEMS devices

Tailoring physical properties of crystals through synthetic temperature control: A case study for new polymorphic NbFeTe2 phases

Growth parameters play a significant role in the crystal quality and physical properties of layered materials. Here we present a case study on a van der Waals magnetic NbFeTe2 material. Two different types of polymorphic NbFeTe2 phases, synthesized at different temperatures, display significantly different behaviors in crystal symmetry, electronic structure, electrical transport, and magnetism. While the phase synthesized at low temperature showing behavior consistent with previous reports, the new phase synthesized at high temperature, has completely different physical properties, such as metallic resistivity, long-range ferromagnetic order, anomalous Hall effect, negative magnetoresistance, and distinct electronic structures. Neutron diffraction reveals out-of-plane ferromagnetism below 70 K, consistent with the electrical transport and magnetic susceptibility studies. Our work suggests that simply tuning synthetic parameters in a controlled manner could be an effective route to alter the physical properties of existing materials potentially unlocking new states of matter, or even discovering new materials