The European,Japanese and US protective helmet,gloves and boots for firefighters: thermoregulatory and psychological evaluations

The purpose of this study was to investigate the physiological and subjective responses of the European, Japanese (JPN) and US firefighters' helmet, gloves and boots for international standardisation. Three experimental conditions were evaluated (clothing mass: 9.4, 8.2 and 10.1 kg for the three conditions, respectively) at the air temperature of 32°C and 60% relative humidity. The results showed that there was no significant difference among the three conditions in oxygen consumption, heart rate, total sweat rate, rectal temperature and mean skin temperature, whereas peripheral temperatures and subjective perceptions were lower in the JPN condition than in the other conditions (P < 0.05). These results indicate that a 0.5-kg reduction in helmet mass and a 1.1-kg reduction in boot mass during exercise resulted in a significant decrease in head and leg temperatures and subjective perceptions, while a 1.9-kg reduction in total clothing mass had insignificant influences on the metabolic burden and overall body temperature.     

Branched poly(biphenylene-co-sulfone)ether ion exchange membranes containing perfluorocyclobutane groups for fuel cell applications

A series of branched poly(biphenylene-co-sulfone) ion exchange membranes containing perfluorocyclobutane groups were prepared for fuel cells. Two bifunctional trifluorovinyloxy-terminated monomers (sulfonable 4,4′-bis(trifluorovinyloxy)biphenyl and insulfonable 4,4′-sulfonyl-bis(trifluorovinyloxy)biphenyl) and a trifunctional trifluorovinyloxy-terminated branching agent (1,1,1-tris(4′-trifluorovinyloxyphenyl)ethane) were synthesized and terpolymerized via thermal [2π + 2π] cyclodimerization to obtain partially fluorinated and branched polymers containing 0–5 mol% of the branching agent. They were then postsulfonated by chlorosulfonic acid at room temperature, cast as membranes, and characterized to evaluate their electrochemical properties for fuel cell applications. As the branching agent content was increased, their polydispersity values highly increased, indicating they became highly branched. It was confirmed that higher branching agent content also increased the ion exchange capacity, water uptake, and proton conductivity of the branched ion exchange membranes containing perfluorocyclobutane groups. This indicates that their electrochemical properties can be easily controlled by the degree of branching. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48373.     

Comparisons between Shikoro-type helmet with no hood and typical fire protective helmets with hood in a hot and humid environment

The purpose of this study was to evaluate physiological and subjective responses while wearing the Shikoro-type helmet for firefighters when compared to typical helmets. Eight firefighters conducted a 30-min exercise at a 5 km h^?1 in three helmet conditions at an air temperature of 32 °C with 70%RH. The results showed that no significant differences in rectal, mean skin temperature and physiological strain index among the three conditions were found during exercise and recovery. Skin temperatures on the cheek, ear and neck during exercise were significantly lower for the Shikoro-type condition (p < 0.05), but forehead temperature was greater for the Shikoro-type helmet when compared to the other conditions (p < 0.05). Statistical differences in thermal sensation and thermal comfort for overall and local body regions were not found among the three conditions. These results imply that the Shikoro-type helmet had local advantages in reducing skin temperatures on the face and neck.

Practitioner Summary: Firefighters wear their helmet with its hood to protect the head and neck but a Shikoro type helmet has no fire protective hood. This study aimed to evaluate the comfort function of Shikoro helmet along with typical helmets. The results demonstrated thermal benefits of the Shikoro helmet on the head.     

Comparison of firefighters and non-firefighters and the test methods used regarding the effects of personal protective equipment on individual mobility

The aims of this study were 1) to evaluate the current pilot test method and ascertain reliable measurements for a standard test method of mobility with personal protective equipment (PPE), such as physical performance and balance ability tests; 2) to compare two participant groups (firefighters versus non-firefighters) and to investigate whether non-firefighters are appropriate as a standard participant group in the field of PPE or not. Totally, 18 participants (nine professional firefighters and nine untrained males) performed the current pilot test method consisting of a balance test, completed prior to and after a performance test. Significant differences were found between PPE conditions and CON (the control clothing ensemble: T-shirt, shorts, and running shoes) for the functional balance test, physical performance test, heart rate, and subjective evaluations in firefighters group. Therefore, the present pilot test method is valid as a standard test method for assessing mobility while wearing PPE. Moreover, the present result shows that firefighters are more reliable than non-firefighters in testing of PPE with current test methods.     

The color tuning of PS-b-P2VP lamellar films with changing the alkyl chain length of 1-iodoalkanes

Photonic crystals with tunability in the visible or near-infrared region have drawn increasing attention for controlling and processing light for the active components of future display. We prepared polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) lamellar films which is hydrophobic block-hydrophilic polyelectrolyte block polymer of 57 kg/mol-b-57 kg/mol. The lamellar stacks, which is alternating layer of hydrophilic and hydrophobic moiety of PS-b-P2VP, are obtained by exposing the spin coated film under chloroform vapor. The band gaps of the lamellar films interestingly varied after immersion into the quaternizing solvents containing 5 wt% of iodomethane, iodoethane, 1-iodobutane, 1-iodopentane, 1-iodohexane and 1-iodooctane solubilized in n-hexane. The iodoalkanes reacted with pyridine groups in PS-b-P2VP and generated the alkyl pyridinium salts readily. The degree of quaternization, alkyl chain length of iodoalkane and the salt water concentration affects the spacing of layer structure of PS-b-P2VP. The iodomethane and iodohexane produced similar band gaps and salt concentration dependence. These results are very much dependent on the hydrophobic-hydrophilic characters of PS-b-P2VP lamellar surface.     

Effects of caffeoylquinic acid analogs derived from aerial parts of Artemisia iwayomogi on adipogenesis

Food Science and Biotechnology - Artemisia iwayomogi (AI) is a perennial herb found in Korea. Its ground parts are dried and used in food and traditional medicine for treating hepatitis,...     

Quality and Functional Characteristics of Chungkukjang Prepared with Various Bacillus sp. Isolated from Traditional Chungkukjang

ABSTRACT: Bacillus circulans, Brevibacillus brevis, B. licheniformis, B. coagulans, B. subtilis , and B. sterothermophillus were isolated and identified from chungkukjangs (Korean traditional soybean paste fermented for a few day). Chungkukjang was prepared on a laboratory scale with soybeans and the isolated strains. Characteristics of the chungkukjangs including slime material content, free amino acid content, sensory qualities, and antimutagenicity were determined. The content of slime material, which is an important indicator of the quality of chungkukjang, was highest in B. licheniformis -inoculated chungkukjang, andlowestin B. sterothermophillus -inoculated chungkukjang. The total content of glycine, glutamic acid, aspartic acid, and arginine, which contribute a savory taste to chungkukjangs, was highest in B. licheniformis-inoculated chungkukjang. The content of leucine, which gives a bitter taste, was highest in B. brevis -inoculated chungkukjang. Sensory evaluation revealed that chungkukjangs made using B. licheniformis and B. subtilishad a weak bitter taste and strong sweet and savory taste and good color, so their overall acceptability was high. Chungkukjang fermented with B. circulans and B. licheniformis inhibited N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG) mutagenicity by more than 80%. B. licheniformis-inoculated chungkukjang exhibited the highest antimutagenicity against and aflatoxin B₁ (AFB₁) and MNNG. These results suggest that using B. licheniformis to ferment chungkukjang increases the antimutagenic properties and improves the sweet and savory taste by increasing glycine, glutamic acid, aspartic acid, and arginine concentrations.     

Asian Dust Storm and pulmonary function of school children in Seoul

Health effects of the Asian Dust Storm (ADS) have not been evaluated adequately, even though it may affect health of people in East Asia. This study was conducted to evaluate whether the ADS affects particulate air pollution and pulmonary function of children. We studied 110 school children in Seoul, Korea with daily measurement of peak expiratory flow rate (PEFR) from May 13 to June 15, 2007. PM_2.5, PM₁₀ and metals bound to the particles were also determined daily during the study period in Ala Shan and Beijing (China) as well as in Seoul (Korea). Three-day back trajectories showed that air parcels arrived at Seoul mostly from the desert areas in China and Mongolia through eastern China during ADS event affecting levels of particulate pollutants in the areas. Analysis of metals bound to the particulates showed that natural metal levels were much higher than the anthropogenic metal levels. We found that ambient concentrations of PM_2.5 and PM₁₀ were not significantly associated with PEFR in school children except asthmatics during the study period (P > 0.05). However, most of the metal concentrations bound to the particulates were significantly associated with decrease of the children's PEFR (P < 0.05). The effect of anthropogenic metals was not different from natural components of metals for reduction of PEFR. This result indicates that exposure to the metals bound to particles during the ADS period reduces children's pulmonary function, but there was no difference of potency for reduction of the pulmonary function between natural and anthropogenic metal components.     

Improving the precision of Hall effect measurements using a single-crystal copper probe

The circuitry and components of a Hall measurement kit were replaced with single-crystal copper (SCC) wires and parts prepared by a novel wire fabrication process. This process preserved the grain-free structure of SCC grown by the Czochralski method. The new kit was used to determine, with greatly improved precision, the electrical coefficients such as carrier density and mobility, establish the reproducibility of the measured values, and define the semiconductor type. The observed reduction in electrical signal losses and distortion has been attributed to grain boundary elimination.