Effect of ventilation improvement during a tuberculosis outbreak in underventilated university buildings

The role of ventilation in preventing tuberculosis (TB) transmission has been widely proposed in infection control guidance. However, conclusive evidence is lacking. Modeling suggested the threshold of ventilation rate to reduce effective reproductive ratio (ratio between new secondary infectious cases and source cases) of TB to below 1 is corresponding to a carbon dioxide (CO₂) level of 1000 parts per million (ppm). Here, we measured the effect of improving ventilation rate on a TB outbreak involving 27 TB cases and 1665 contacts in underventilated university buildings. Ventilation engineering decreased the maximum CO₂ levels from 3204 ± 50 ppm to 591-603 ppm. Thereafter, the secondary attack rate of new contacts in university dropped to zero (mean follow-up duration: 5.9 years). Exposure to source TB cases under CO₂ >1000 ppm indoor environment was a significant risk factor for contacts to become new infectious TB cases (P < .001). After adjusting for effects of contact investigation and latent TB infection treatment, improving ventilation rate to levels with CO₂ <1000 ppm was independently associated with a 97% decrease (95% CI: 50%-99.9%) in the incidence of TB among contacts. These results show that maintaining adequate indoor ventilation could be a highly effective strategy for controlling TB outbreaks.     

Nonlocal heat transport with phonons and electrons: Application to metallic nanowires

In the framework of Extended Irreversible Thermodynamics we develop a model for coupled heat conduction by phonons and electrons. Particular emphasis is given to nonlocal effects, which may arise when the mean-free paths of phonons and/or electrons are comparable to the size of the system. As particular cases, we recover two parabolic equations of the Guyer–Krumhansl type which model the concurrent presence of the diffusion of heat superposed to the propagation of heat waves, and two hyperbolic equations of the Maxwell–Cattaneo type. In the latter case, the phase speed of temperature waves is calculated. The size dependence of the Wiedemann–Franz law is briefly analyzed for metallic nanowires.     

Fabrication and characterization of electrolyte membranes based on organoclay/tripropyleneglycol diacrylate/poly(vinylidene fluoride) electrospun nanofiber composites

Utilizing polymer electrospinning technology, novel electrolyte membranes based on poly(vinylidene fluoride) (PVDF)/organomodified clay (OC)/tripropyleneglycol diacrylate (TPGDA) composite nanofibers with a diameter of 100–400 nm were fabricated for application in lithium batteries. Ultraviolet photo‐polymerization of electrospun PVDF/OC/TPGDA nanofibers generated chemically crosslinked TPGDA‐grafted PVDF/OC nanofibers exhibiting robust mechanical and electrochemical properties. The prepared fibrous PVDF/OC/TPGDA electrolytes were characterized in terms of morphology, crystallinity, electrochemical stability, ionic conductivity and cell cycleability. Based on differential scanning calorimetry analysis, the crystallinity of PVDF decreased by ca 10% on employing the OC and TPGDA. Compared with pure PVDF film‐based electrolyte membranes, the TPGDA‐ and OC‐modified PVDF electrolyte membranes exhibited improved mechanical properties and various electrochemical properties. The OC‐ and TPGDA‐modified microporous membranes are promising candidates for overcoming the drawbacks of the lower mechanical stability of fibrous‐type electrolytes with further improvement of electrochemical performance. Copyright © 2009 Society of Chemical Industry     

Wideband Matched CMOS LNA Design Using R-L-C Loading Network

This paper proposes a new methodology for designing and analyzing wideband matched CMOS LNA with R-L-C loading network, where validity of this new approach is supported by the agreement between the simulated input impedance of the LNA and its calculated counterpart. To demonstrate its feasibility, two wideband matched LNA’s are designed using TSMC 0.18-μm RF-CMOS process. One is for 3–8 GHz application and the second one targets at 8–25 GHz frequency range. The measured results of both circuits will then be presented.     

Automobile drivers’ willingness to pay for moving violation behaviour—Compared to motorcyclists

A triple-bounded dichotomous choice (TBDC) structure and Spike models are applied to investigate the amount of money Taiwan automobile drivers are willing to pay for five types of moving violations, including local street speeding, expressway and freeway speeding, red light running, right turn on red, and drink-driving. Face-to-face survey was conducted at freeway rest areas by targeting passenger car drivers. The Spike model, superior to other tradition models by capturing excessive zero responses, is applied and the estimated results show that speeders would accept willingness to pay (WTP) of US$37 and US$48,¹ respectively, for local roads and expressways and highways, while red-light runners would accept a WTP of US$44, drivers who turn right on red would accept a lower WTP of US$9, and drunk drivers will accept a WTP as high as US$597. Interestingly, the difference in WTP for drunk driving between drivers and motorcyclists is significant, while others are not.     

Versatile α,ω‐Disubstituted Tetrathienoacene Semiconductors for High Performance Organic Thin‐Film Transistors

Facile one‐pot [1 + 1 + 2] and [2 + 1 + 1] syntheses of thieno[3,2‐b]thieno[2′,3′:4,5]thieno[2,3‐d]thiophene (tetrathienoacene; TTA) semiconductors are described which enable the efficient realization of a new TTA‐based series for organic thin‐film transistors (OTFTs). For the perfluorophenyl end‐functionalized derivative DFP‐TTA , the molecular structure is determined by single‐crystal X‐ray diffraction. This material exhibits n‐channel transport with a mobility as high as 0.30 cm²V^?1s^?1 and a high on‐off ratio of 1.8 × 10⁷. Thus, DFP‐TTA has one of the highest electron mobilities of any fused thiophene semiconductor yet discovered. For the phenyl‐substituted analogue, DP‐TTA , p‐channel transport is observed with a mobility as high as 0.21 cm²V^?1s^?1. For the 2‐benzothiazolyl (BS‐) containing derivative, DBS‐TTA , p‐channel transport is still exhibited with a hole mobility close to 2 × 10^?3 cm²V^?1s^?1. Within this family, carrier mobility magnitudes are strongly dependent on the semiconductor growth conditions and the gate dielectric surface treatment.     

Inter-laboratory comparison of biaxial tests for architectural textiles

Architectural fabrics are used in high-profile tensile structures worldwide, and the accurate determination of fabric material properties is vital to achieve safe, efficient designs. There are currently limited standards for biaxial testing of fabrics used in building structures. The ability to carry out repeatable tests in multiple locations is vital for the validation and implementation of the forthcoming Eurocode 10, which will include requirements for the design of fabric structures. This paper describes the comparison of two biaxial test machines using finite element analysis of the cruciform test specimens and discusses the difficulties inherent in comparison of test results. It is found that exact replication of test protocols on two different machines is difficult to achieve, and a method is developed to facilitate a meaningful comparison of test data where the timing and/or stress levels differ between tests. Guidelines are provided to assist in future comparative testing.     

The Impact of Grape Skin Bioactive Functionality Information on the Acceptability of Tea Infusions Made from Wine By-Products

ABSTRACT: The effect of information on the health benefits of bio-active compounds on the acceptability of 5 tea infusions made from grape skins generated from wine processing waste (from Vitis vinifera var. Pinot Noir and Pinot Gris) was investigated. Samples of tea infusions with natural additives (PNHGT25 and PGGT50) and without additives (control PN, control PG, and PNPG50) were evaluated by 45 in-home consumer panels (30 female, 15 male) before and after information on the health benefits of grape skins were provided. Information significantly increased the overall acceptability, overall aroma, flavor, and aftertaste of the infusions. The results obtained showed a clear tendency toward increased purchase intention (by 29%) when information on the health benefits of the tea infusion samples was provided to consumers. Interactions existed between gender/infusion samples and stage of information on the purchase intention. Females recorded a significant increase (by 53%) in purchase intention, whereas no change in the males' purchase intention was found after information was provided.     

Vapor adsorption characteristics of toluene in an activated carbon adsorbent-loaded nonwoven fabric media for chemical filters applied to cleanrooms

Chemical filters are used extensively in the cleanrooms of the semiconductor factories to remove airborne molecular contamination (AMC). Adsorption by activated carbons (AC) as media within the chemical filter is one of the practical methods for removal of gaseous contamination in a cleanroom. The objective of this study is to evaluate coconut shell activated carbon adsorbent-loaded nonwoven fabric media performance by determining the breakthrough curves, the linear driving force (LDF), the intra-particle diffusion characteristics, the empty bed contact time (EBCT) and the bed depth service time (BDST), the mass-transfer zone (MTZ), and pressure drop. The testing conditions were maintained at 28 ± 1 °C, and relative humidity at 40 ± 2% with face velocities of 0.076, 0.114 and 0.152 m/s for removal efficiency and capacity determination. The challenge gas concentrations of toluene were fixed at 10, 31, 42 and 70 ppm to accelerate the breakthrough of media adsorption. The concentrations were measured by a real-time photoionization detector. Results showed that breakthrough curves correlate to the challenge vapor concentration and the face velocity. Saturated adsorption ratio was increased with raised challenge gas concentration and increased face velocity significantly.