Applied Mechanics and Materials Vols. 295-298

Abstract: The seasonal correlation of the same kind of heavy metal and the relationship between different heavy metals’ content were discussed, and the pollution characteristics of heavy metal were assessed by using the potential ecological risk index method. The results show that the content of heavy metals are higher in autumn and winter and lower in spring and summer. The content of Pb only has the significant correlation between autumn and winter at the 0.01 level. It has no significant correlation between the content of Cd, As, Pb and Cr in four seasons. The content of Cr and Pb is significantly correlated in winter at 0.05 level. The potential ecological risk level of Cd belongs to the slight ecological risk in spring and the medium ecological risk in the other seasons. The potential ecological risk level of As, Pb and Cr belong to the slight ecological risk in four seasons.

Abstract: This study aimed to provide insight into antimicrobial susceptibility and homology of Elizabethkingia meningoseptica in a hospital environment. Samples from environmental surfaces and the hands of medical staff were screened for E. meningoseptica and antimicrobial susceptibility testing was performed; Pulsed-Field Gel Electrophoresis (PFGE) was employed to subtype E. meningoseptica strains; The resistant genes were detected by PCR. In total, six isolates of E. meningoseptica were collected from 280 samples. Antimicrobial susceptibility testing revealed that all of the six strains displayed multiresistance, showing resistance to more than three different classes of antibiotics. The strains were separated into five different PFGE patterns. The sulII gene was detected in four of the strains. Our data show that multiresistant E. meningoseptica strains exist in the hospital environment and susceptibility testing revealed that vancomycin was the most effective antibiotic. These results have practical significance for treatment of E. meningoseptica infection.

Abstract: A small-scale crude oil tank boilover experimental device was established to study the basic characteristics of boilover phenomenon. The boilover starting time was mainly focused in order to make the proper fire rescue strategy. The results indicate that, the commonly used methods of predicting the boilover starting time show a relatively great deviation with the results obtained in experiments. The boilover starting time is linearly proportional to the parameter Ho/D0.5, which agrees Tan’s equation. However, Tan’s equation underestimates the boilover starting time when Ho/D0.5≤0.09 and overestimates the boilover starting time when Ho/D0.5>0.09.

Abstract: Water safety is an important branch in the field of safety. By using the periphery theory and the similarity measure of Vague sets, the emergency rescue method of urban raw water safety which are used to meet the emergency demands with certain level of safety in emergencies were discussed. The periphery model of urban raw water system was established, and the mechanism of emergency rescue of raw water system to the safety was analyzed; the evaluation indicator system was constructed in two dimensions of pressure and support, and the principles for determining the control factors of emergency rescue of urban raw water safety were presented; the evaluation indicators were measured by formulas of similarity measure of Vague sets, and pressure indexes and support indexes of the periphery of the urban raw water system, as well as the formulas for emergency rescue of urban raw water safety were established; recommended evaluation standards for the emergency rescue degree of urban raw water safety in emergencies were provided, and methods to achieve the emergency rescue of urban raw water safety with certain safety level through emergency rescue control factors were put forward. With the raw water system of Chengdu as the background, application analysis of the established emergency rescue methods of urban raw water safety was conducted. The analysis results show that the established methods can achieve the emergency rescue of urban raw water safety with certain safety level in emergencies through the emergency rescue control factors and according to the emergency demands.

Abstract: This paper highlights the importance of departmental faculty wellness within a workplace and the development of wellness strategies as well as program including departmental wellness tips and program for improving physical wellness. This project is based on establishing a set of long-term wellness strategies from both macro-level and micro-level. Both department and faculties should take responsibility to contribute to the improvement of institutional faculty wellness from physical, emotional, spiritual, social, mental, resourceful and environmental dimensions.

Abstract: In order to study the diffusion pattern of Unsymmetrical Dimethyl Hydrazine (UDMH) in a confined space, a 3D geometric model of cylindrical space with a column obstacle in the center was built and diffusion of UDMH in the space was simulated by using FLUENT. The gas concentration distribution in the space was gained at different moments, and the polluted area with concentration above 0.5ppm was focused on. The simulation result suggests that the toxic gas is mainly concentrated in an area about 1m above the bottom of the space, and ventilation can effectively reduce the hazard time and continuous expansion of polluted area.

Abstract: A rapid removal method of hydrogen sulfide (H2S) gas is studied in the present paper at ambient conditions. These capture agents are powers of grain sizes and convenient for injection on H2S gas at the site of accident. The agents are characterized by SEM and N2 adsorption-desorption method, etc. The test on capturing H2S was experimented and the result indicated that the prepared agents can reduce the H2S concentration in the air to a harmless level rapidly.

Abstract: Sulfur dioxide (SO₂) is a ubiquitous air pollutant which causes kinds of damage to human and other organisms. However, the effects and mechanisms on the plasma membrane when cells and tissues were exposed to SO₂ were still unknown. The results herein showed a gradual reduction in body weight and dry lung weight for rats exposed to SO₂. The wet lung weights were increased. The changes indicated SO2 inhalation caused pulmonary tissue permeability edema. _{Subscript text}The pulmonary permeability was increase_{Subscript textSubscript textSubscript text}d by the determination of protein contents in BALs and pulmonary permeability index (PPI). The intracellular proteins were penetrated into extracellular matrix. The total leukocytes in BALs of rats in each group exposed to SO₂ were significantly increased, and the granulocytes were also increased significantly. However, the lymphocytes in BALs of rats exposed SO₂ were to some extent different to the control groups. The activities of acid phosphatase (ACP), alkaline phosphatase (AKP) and lactic dehydrogenase (LDH) in BALs were increased to some extent. The results showed that the functions of plasma membrane were damaged with the damage of membrane structure, parts of the membrane bound enzymes and intracellular enzymes were released into BALs. The membrane fluidity in AM cells were significantly decreased by the determination of steady-state fluorescent polarization degree (P) and fluorescence microviscosity (η) of the AM.

Abstract: The object of this paper is to measure the characteristics of the inactivation kinetics of B. subtilis spores-surrogates for B. anthracis spores following the treatment with free chlorine. The results indicated that the inactivation kinetics of B. subtilis spores with free chlorine was characterized by a lag phase followed by a pseudo-first-order rate of inactivation. The magnitude of the lag phase increased and the rate of subsequent inactivation decreased with the decreasing temperature, for the experimental temperature range of 1-30 °C. The same tendency of inactivation kinetics curves was observed for the increasing solution pH, for the experimental pH range of 6-8. The CT concept was proved to be valid for the inactivation kinetics of B. subtilis spores with free chlorine under the conditions investigated. The validity of B. subtilis spores served as conservative surrogates for B. anthracis spore has been finally discussed.

Abstract: In recent years, with the center of the city to promote ecological construction, polluting enterprises have gradually transferred to the county, and serious environmental pollution and environmental conflicts are brought to the county. And because of county governments are in the end of the status of the urban power pyramid system, the regional environmental collaborative development mechanism remains to be further improve, the county government performance evaluation is still mainly in terms of GDP, the tenure system led to the prevalence of short-term behavior, supervision of production safety and technological transformation not in place, as well as lack of environmental accountability and effective environmental compensation mechanism and so on, the county environmental crisis happened frequently, governance falls into trouble. Therefore, in the context of the environmental crisis, effective county governance embodies fair regional collaborative development mechanism, further innovate performance evaluation and reform the existing cadres of the tenure system, strengthen supervision of production safety and technological innovation, improve environmental accountability and environmental compensation system, etc.