• 제목/요약/키워드: university laboratory safety

검색결과 1,640건 처리시간 0.023초

Microbial Floral Dynamics of Chinese Traditional Soybean Paste (Doujiang) and Commercial Soybean Paste

  • Gao, Xiuzhi;Liu, Hui;Yi, Xinxin;Liu, Yiqian;Wang, Xiaodong;Xu, Wensheng;Tong, Qigen;Cui, Zongjun
    • Journal of Microbiology and Biotechnology
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    • 제23권12호
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    • pp.1717-1725
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    • 2013
  • Traditional soybean paste from Shandong Liangshan and Tianyuan Jiangyuan commercial soybean paste were chosen for analysis and comparison of their bacterial and fungal dynamics using denaturing gel gradient electrophoresis and 16S rRNA gene clone libraries. The bacterial diversity results showed that more than 20 types of bacteria were present in traditional Shandong soybean paste during its fermentation process, whereas only six types of bacteria were present in the commercial soybean paste. The predominant bacteria in the Shandong soybean paste were most closely related to Leuconostoc spp., an uncultured bacterium, Lactococcus lactis, Bacillus licheniformis, Bacillus spp., and Citrobacter freundii. The predominant bacteria in the Tianyuan Jiangyuan soybean paste were most closely related to an uncultured bacterium, Bacillus licheniformis, and an uncultured Leuconostoc spp. The fungal diversity results showed that 10 types of fungi were present in the Shandong soybean paste during the fermentation process, with the predominant fungi being most closely related to Geotrichum spp., an uncultured fungal clone, Aspergillus oryzae, and yeast species. The predominant fungus in the commercial soybean paste was Aspergillus oryzae.

DL-RRT* algorithm for least dose path Re-planning in dynamic radioactive environments

  • Chao, Nan;Liu, Yong-kuo;Xia, Hong;Peng, Min-jun;Ayodeji, Abiodun
    • Nuclear Engineering and Technology
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    • 제51권3호
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    • pp.825-836
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    • 2019
  • One of the most challenging safety precautions for workers in dynamic, radioactive environments is avoiding radiation sources and sustaining low exposure. This paper presents a sampling-based algorithm, DL-RRT*, for minimum dose walk-path re-planning in radioactive environments, expedient for occupational workers in nuclear facilities to avoid unnecessary radiation exposure. The method combines the principle of random tree star ($RRT^*$) and $D^*$ Lite, and uses the expansion strength of grid search strategy from $D^*$ Lite to quickly find a high-quality initial path to accelerate convergence rate in $RRT^*$. The algorithm inherits probabilistic completeness and asymptotic optimality from $RRT^*$ to refine the existing paths continually by sampling the search-graph obtained from the grid search process. It can not only be applied to continuous cost spaces, but also make full use of the last planning information to avoid global re-planning, so as to improve the efficiency of path planning in frequently changing environments. The effectiveness and superiority of the proposed method was verified by simulating radiation field under varying obstacles and radioactive environments, and the results were compared with $RRT^*$ algorithm output.

대학 연구실험실 안전환경과 교육시간에 대한 만족도 조사 (A Satisfaction Survey On the Safety Environment and Education Time in University Laboratories)

  • 이종호
    • 한국안전학회지
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    • 제25권4호
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    • pp.36-41
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    • 2010
  • This paper seeks to survey and analyze the status of obligatory execution from key institutional aspects that have taken effect according to laws on creating safe environment for laboratory and of general details such as the level of satisfaction on the part of people engaged in research activity regarding the laws after they have taken effect. The subjects of this study were MA and PhD graduate students in science and engineering who are primarily involved in research. This questionnaire survey was focused on finding basic data required for safety education for researcher and for efficient safety management by examining the correlation between education time and level of satisfaction. The collected data were analyzed by using frequency analysis, descriptive statistics, one way anova by SPSS12 package. The results obtained by this study are as follow. 1) Awarences of safety management rules, ordinary inspection, safety education were around 70% and other law clauses were around 50%. 2) The general satisfaction after the Laboratory Safety Act enforcement was usual level with 4.72 points in 7. 3) Researchers demanded ordinary inspection and protective equipment in a safe environmental composition. 4) The safety education time for improvement of a safe consciousness level was needed 12h or 24h at 1 years.

Effect of bamboo shoot dietary fiber on gel properties, microstructure and water distribution of pork meat batters

  • Li, Ke;Liu, Jun-Ya;Fu, Lei;Zhao, Ying-Ying;Zhu, He;Zhang, Yan-Yan;Zhang, Hua;Bai, Yan-Hong
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권7호
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    • pp.1180-1190
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    • 2020
  • Objective: To develop healthier comminuted meat products to meet consumer demand, the gel properties, rheological properties, microstructure and water distribution of pork meat batters formulated with various amounts of bamboo shoot dietary fiber (BSDF) were investigated. Methods: Different levels of BSDF (0% to 4%) were added to pork batters, and the pH, color, water-holding capacity, texture and rheological properties of pork batters were determined. Then, pork batters were analyzed for their microstructure and water distribution using scanning electron microscopy (SEM) and low-field nuclear magnetic resonance (LF-NMR). Results: Compared with the control, BSDF addition into meat batters showed a significant reduction in L*-value and a significant increase in b*-value (p<0.05). BSDF addition of up to 4% reduced the pH value of pork batters by approximately 0.15 units; however, the cooking loss and expressible water loss decreased significantly (p<0.05) with the increased addition of BSDF. The hardness and gel strength were noticeably enhanced (p<0.05) as the content of BSDF increased. The rheological results showed that BSDF added into pork batters produced higher storage modulus (G') and loss modulus (G") values. The SEM images suggested that the addition of BSDF could promote pork batters to form a more uniform and compact microstructure. The proportion of immobilized water increased significantly (p<0.05), while the population of free water was decreased (p<0.05), indicating that BSDF improved the water-holding capability of pork batters by decreasing the fraction of free water. Conclusion: BSDF could improve the gel properties, rheological properties and water distribution of pork meat batters and decrease the proportion of free water, suggesting that BSDF has great potential as an effective binder in comminuted meat products.

A two-stage Kalman filter for the identification of structural parameters with unknown loads

  • He, Jia;Zhang, Xiaoxiong;Feng, Zhouquan;Chen, Zhengqing;Cao, Zhang
    • Smart Structures and Systems
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    • 제26권6호
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    • pp.693-701
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    • 2020
  • The conventional Kalman Filter (KF) provides a promising way for structural state estimation. However, the physical parameters of structural systems or models should be available for the estimation. Moreover, it is not applicable when the loadings applied to the structures are unknown. To circumvent the aforementioned limitations, a two-stage KF with unknown input approach is proposed for the simultaneous identification of structural parameters and unknown loadings. In stage 1, a modified observation equation is employed. The structural state vector is estimated by KF on the basis of structural parameters identified at the previous time-step. Then, the unknown input is identified by Least Squares Estimation (LSE). In stage 2, based on the concept of sensitivity matrix, the structural parameters are updated at the current time-step by using the estimated structural states obtained from stage 1. The effectiveness of the proposed approach is numerically validated via a five-story shearing model under random and earthquake excitations. Shaking table tests on a five-story structure are also employed to demonstrate the performance of the proposed approach. It is demonstrated from numerical and experimental results that the proposed approach can be used for the identification of parameters of structure and the external force applied to it with acceptable accuracy.

An improved extended Kalman filter for parameters and loads identification without collocated measurements

  • Jia He;Mengchen Qi;Zhuohui Tong;Xugang Hua;Zhengqing Chen
    • Smart Structures and Systems
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    • 제31권2호
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    • pp.131-140
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    • 2023
  • As well-known, the extended Kalman filter (EKF) is a powerful tool for parameter identification with limited measurements. However, traditional EKF is not applicable when the external excitation is unknown. By using least-squares estimation (LSE) for force identification, an EKF with unknown input (EKF-UI) approach was recently proposed by the authors. In this approach, to ensure the influence matrix be of full column rank, the sensors have to be deployed at all the degrees-of-freedom (DOFs) corresponding to the unknown excitation, saying collocated measurements are required. However, it is not easy to guarantee that the sensors can be installed at all these locations. To circumvent this limitation, based on the idea of first-order-holder discretization (FOHD), an improved EKF with unknown input (IEKF-UI) approach is proposed in this study for the simultaneous identification of structural parameters and unknown excitation. By using projection matrix, an improved observation equation is obtained. Few displacement measurements are fused into the observation equation to avoid the so-called low-frequency drift. To avoid the ill-conditioning problem for force identification without collocated measurements, the idea of FOHD is employed. The recursive solution of the structural states and unknown loads is then analytically derived. The effectiveness of the proposed approach is validated via several numerical examples. Results show that the proposed approach is capable of satisfactorily identifying the parameters of linear and nonlinear structures and the unknown excitation applied to them.

유해·위험물질 취급 화학실험실 관리 기준 정립 및 체계 개선에 관한 연구 (Study on Establishment of management standards of Chemistry laboratory handling harzadous substances and improvement of system)

  • 조남준;이만수
    • 대한안전경영과학회지
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    • 제18권4호
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    • pp.57-72
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    • 2016
  • There are more than 30,000 chemical substances handled in domestic university laboratories. Among them, hazardous materials are selected and managed as designated substances by the standards of 19 Ministries and 16 Acts. However, domestic safety-related laws and regulations are used to manage industrial risk factors based on industrial activities. In case of installing a university chemical laboratory in accordance with the installation standards applicable to general workplaces. It is not suitable to use as a laboratory installation standard that can be applied to a chemical laboratory installed at a university such as a problem occurs in applying to a university using a small quantity of dangerous substances in a small amount. In order to establish the laboratory structure and facility standards that are appropriate for the laboratory characteristics and apply systematic laboratory safety, the National Security Administration shall apply the special handling standard of chemical experiment to places where handling less than 30 times the designated quantity of chemical substances for chemical experiments. On August 2, 2016, the regulations for the enforcement of the Dangerous Goods Safety Management Act and the standards for the structure and facilities of the university chemical laboratory were enacted. In this study, we investigated the domestic chemical substances laws and regulations to determine the chemical substances that are over-regulated in the relevant laws, and define them as substances against accidents. The management criteria for the substances were analyzed. The R value for the designation of the designated quantity by the concept of the space in the management standard was calculated.

Glutamate attenuates lipopolysaccharide induced intestinal barrier injury by regulating corticotropin-releasing factor pathway in weaned pigs

  • Guo, Junjie;Liang, Tianzeng;Chen, Huifu;Li, Xiangen;Ren, Xiaorui;Wang, Xiuying;Xiao, Kan;Zhao, Jiangchao;Zhu, Huiling;Liu, Yulan
    • Animal Bioscience
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    • 제35권8호
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    • pp.1235-1249
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    • 2022
  • Objective: The purpose of this study was to evaluate the protection of glutamate (GLU) against the impairment in intestinal barrier function induced by lipopolysaccharide (LPS) stress in weaned pigs. Methods: Twenty-four weaned pigs were divided into four treatments containing: i) non-challenged control, ii) LPS-challenged control, iii) LPS+1.0% GLU, and iv) LPS+2.0% GLU. On day 28, pigs were treated with LPS or saline. Blood samples were collected at 0, 2, and 4 h post-injection. After blood samples collection at 4 h, all pigs were slaughtered, and spleen, mesenteric lymph nodes, liver and intestinal samples were obtained. Results: Dietary GLU supplementation inhibited the LPS-induced oxidative stress in pigs, as demonstrated by reduced malondialdehyde level and increased glutathione level in jejunum. Diets supplemented with GLU enhanced villus height, villus height/crypt depth and claudin-1 expression, attenuated intestinal histology and ultrastructure impairment induced by LPS. Moreover, GLU supplementation reversed intestinal intraepithelial lymphocyte number decrease and mast cell number increase induced by LPS stress. GLU reduced serum cortisol concentration at 4 h after LPS stress and downregulated the mRNA expression of intestinal corticotropin-releasing factor signal (corticotrophin-releasing factor [CRF], CRF receptor 1 [CRFR1], glucocorticoid receptor, tryptase, nerve growth factor, tyrosine kinase receptor A), and prevented mast cell activation. GLU upregulated the mRNA expression of intestinal transforming growth factor β. Conclusion: These findings indicate that GLU attenuates LPS-induced intestinal mucosal barrier injury, which is associated with modulating CRF signaling pathway.

무선 감시 시스템을 활용한 연구실 사고의 비상대응체계 개발에 대한 연구 (Study on Developing Emergency Response Procedure in Laboratory accident with Wireless Detecting System)

  • 이만수
    • 대한안전경영과학회지
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    • 제17권2호
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    • pp.139-145
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    • 2015
  • In these days, hazards in laboratories are consistently increasing due to high technological advance in modern science. Efforts to prevent accidents in laboratories became law named [ACT ON THE ESTABLISHMENT OF SAFE LABORATORY ENVIRONMENT]. The law made laboratories more safely but it's not enough to keep up laboratory safety in advanced countries. To improve laboratory safety, this study reformed laboratory emergency response flow chart based on each emergency scenarios and its evaluated hazards in laboratories applied wireless hazard detecting equipments.

Strain demand prediction of buried steel pipeline at strike-slip fault crossings: A surrogate model approach

  • Xie, Junyao;Zhang, Lu;Zheng, Qian;Liu, Xiaoben;Dubljevic, Stevan;Zhang, Hong
    • Earthquakes and Structures
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    • 제20권1호
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    • pp.109-122
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    • 2021
  • Significant progress in the oil and gas industry advances the application of pipeline into an intelligent era, which poses rigorous requirements on pipeline safety, reliability, and maintainability, especially when crossing seismic zones. In general, strike-slip faults are prone to induce large deformation leading to local buckling and global rupture eventually. To evaluate the performance and safety of pipelines in this situation, numerical simulations are proved to be a relatively accurate and reliable technique based on the built-in physical models and advanced grid technology. However, the computational cost is prohibitive, so one has to wait for a long time to attain a calculation result for complex large-scale pipelines. In this manuscript, an efficient and accurate surrogate model based on machine learning is proposed for strain demand prediction of buried X80 pipelines subjected to strike-slip faults. Specifically, the support vector regression model serves as a surrogate model to learn the high-dimensional nonlinear relationship which maps multiple input variables, including pipe geometries, internal pressures, and strike-slip displacements, to output variables (namely tensile strains and compressive strains). The effectiveness and efficiency of the proposed method are validated by numerical studies considering different effects caused by structural sizes, internal pressure, and strike-slip movements.