New approach to calculate the probability of ignition

The probabilistic approach to the evaluation of fire hazard and the effectiveness of fire-precaution measures enables a rational response to the randomness of fire outbreaks. This article employs the statistical analysis methods to elucidate the causes for the ignition of fire on a random sample of industrial buildings in the Republic of Slovenia. The analyses are based on the Structural Equation Modeling (SEM), which is a well established and important statistical analysis technique in the fields of social science, biology, psychology and medicine, but hitherto rarely applied in safety research. The results of the study demonstrate that for the analyzed random sample of industrial buildings the frequency of fire outbreaks statistically significantly depends only on the presence and the probability of exposure to the heat sources (flames, sparks, and hot surfaces), but does not significantly depend on the available quantity of flammable materials within the industrial structure.     

Heart rate variability and motion sickness during forklift simulator driving

The goal of the study was to determine the effect of a 1-h hour long forklift truck virtual simulator driving on the mechanism of autonomic heart rate (HR) regulation in operators. The participants were divided into 2 subgroups: subjects with no definite inclination to motion sickness (group A) and subjects with a definite inclination to motion sickness (group B). Holter monitoring of electrocardiogram (ECG) signal was carried out in all subjects during the virtual simulator driving. For 12 consecutive epochs of ECG signal, HR variability analysis was conducted in time and frequency domains. In subjects with a definite inclination to motion sickness after ~30 min of the driving, changes in parameter values were found indicating an increase in sympathetic and parasympathetic activity with parasympathetic dominance.     

Evaluation of sound exposure and risk of hearing impairment in orchestral musicians

This study aimed to assess exposure to sound and the risk of noise-induced hearing loss (NIHL) in orchestral musicians. Sound pressure level was measured in 1 opera and 3 symphony orchestras; questionnaires were filled in. On the basis of that data, the risk of NIHL was assessed according to Standard No. ISO 1999:1990. Classical orchestral musicians are usually exposed to sound at equivalent continuous A-weighted sound pressure levels of 81?90 dB (10th?90th percentiles), for 20?45 h (10th?90th percentiles) per week. Occupational exposure to such sound levels over 40 years of employment might cause hearing loss (expressed as a mean hearing threshold level at 2, 3, 4 kHz exceeding 35 dB) of up to 26%. Playing the horn, trumpet, tuba and percussion carries the highest risk (over 20%).     

Synthesis and application of graphene oxide as a nanoadsorbent to remove Cd (II) and Pb (II) from water: adsorption equilibrium,kinetics, and regeneration

Environmental Science and Pollution Research - In this work, graphene oxide (GO) was synthesized by the modified Hummers method. The nanomaterial was characterized by FTIR and Raman spectroscopy,...     

航空压力环境对锂离子电池热解气体爆炸极限影响*

针对航空锂离子电池热失控释放气体安全性研究不足的问题,采用气体拉曼光谱技术、气相色谱仪(Gas Chromatography,GC)和质谱(Mass Spectroscopy,MS)耦合来探究压力和荷电状态(State of Charge,SOC)对锂离子电池早期故障气体类型、气体动态演变及气体潜在危险性等特征的影响规律,同时综合考虑压力、电压和电池温度等多种因素分析锂离子电池热失控危害。研究结果表明:电池SOC越高且环境压力越低,电池越早触发热失控,爆炸极限越宽,其中30 kPa下100%SOC电池热解气体爆炸极限为8.01%~53.35%;SOC和环境压力越高,电池热失控越危险,释放的气体体积越多;CO,CO2,PF3,C2H4及电解液（C3H6O2、C3H6O3、C4H8O2）等气体可作为航空锂离子电池早期故障诊断特征。研究结果对保障锂离子电池在航空领域的安全运输及应用具有重要意义。     

Spatial variation of otolith elemental signatures among juvenile gray snapper (<Emphasis Type="Italic">Lutjanus griseus</Emphasis>) inhabiting southern Florida waters

Juvenile gray snapper, Lutjanus griseus, are believed to use bays and estuaries in southern Florida as nurseries before moving out to the adjoining reef tract as adults. Using high-resolution sector field-inductively coupled plasma-mass spectrometry (SF-ICP-MS), the elemental chemistry of the otoliths of juveniles from five nursery regions was resolved by establishing elemental “signatures” for each region. In this study we simultaneously analyzed 32 elements including a suite of rare earth elements. A stepwise variable selection procedure retained a subset of eight elements that contributed substantially to separating otolith samples, including two rare earth elements; this is one of the first studies in which rare earth elements in otoliths have contributed to separation of fish stocks. The classification success rate in assigning fishes to the correct region of origin was 82%. Resolution of sites less than 10 km apart suggested high site fidelity in juvenile gray snapper and little mixing of water masses between sites. The juvenile nursery signatures will be used to determine the relative contribution of different nurseries to the adult population on an adjoining reef tract.     

Controlling mechanisms of aluminium in soil solution--an evaluation of 180 podzolic forest soils.

To monitor the level of soil acidification in the county of V?rmland in the middle west of Sweden 180 podzolic forest soils were investigated. Soil solutions from four horizons were obtained by centrifugation and the soil was sampled for a determination of the exchangeable pool by extraction. The concentrations of inorganic Al and its fraction of the total Al in solution were greater in the south of the county (up to 50%). The factors influencing the total Al and free inorganic Al3+ in the soil solutions were evaluated. Saturation indices (SI) for five different mineral phases were calculated but none implied equilibrium conditions. The relationships between pAl3+ and pH (in the pH range 4-6.2) gave slopes of about 1, which indicated that ion exchange/complexation reactions may be important for determining the Al3+ concentration in the B and C horizons. In the E horizon solutions complexation with soluble organic acids seemed to be the major factor which influenced the Al3+ activity. The influence of organic matter on Al solubility was supported by partial least square (PLS) regressions.     

Environmental fate and bioavailability of wood preservatives in freshwater sediments near an old sawmill site.

Impacts of an old contaminated sawmill site located in Eastern Finland were studied, with emphasis on transportation and bioaccumulation of wood preservatives in the surrounding water system. To assess the transportation of chlorophenols and chromated copper arsenate (CCA) from the sawmill to the nearby lake, the concentrations of these compounds in selected sediment samples were analyzed. To assess the contribution of a pulp mill further upstream, the concentration of extractable organic halogens (EOX) was analyzed. Bioaccumulation of wood preservatives from sediments was examined using Lumbriculus variegatus as test organism. In sediments collected from the sawmill area, concentrations of chlorophenols, arsenic, chromium and copper were high. In the surrounding area the concentrations of these compounds were slightly elevated at some sampling points but were mostly within the natural range of variation. Thus, it can be concluded that transportation of wood preservatives from the sawmill area to its surroundings is fairly low. However, 60 microg/l of arsenic and 50 microg/l of copper were found in water taken from a brook that runs through a landfill area of the sawmill to the nearby river, and the concentration of arsenic in the surface sediment at one sampling point in the lake was slightly elevated. The total amount of organohalogens in sediment was higher in the river and the lake than in the sawmill area. Of all the wood preservatives studied, only arsenic was found to bioaccumulate in present conditions, reaching a tissue concentration of 362 microg/g dw in organisms exposed for 28 days to sediment from the brook. High concentration of arsenic in oligochaeta tissue was related to high concentration of arsenic in the pore water.     

Formation of singlet oxygen during farmorubicin oxidation.

The enhanced generation of singlet oxygen (1O2) during oxidation of farmorubicin in the Co(II) + H2O2 system was studied using chemiluminescent, fluorescent and spectrophotometic techniques. The influence of 1O2-quenchers, catalase, superoxide anion radical (O2*-) and hydroxyl radical (HO*) scavengers on the light emission was studied. The spectrophotometric determination of 1O2 was based on bleaching of p-nitrosodimethylaniline caused by an intermediate product of the reaction of 1O2 with imidazole, and was followed by monitoring the decrease in optical density at 440 nm.