Papers by Keyword: Hazard

Abstract: In contrast to bulk materials, nanoparticles, which are distinguished by their extremely small size and remarkable surface area-to-volume ratio, have unique physical and chemical properties. Among the several metal-oxide nanoparticles, green zinc oxide nanoparticles have drawn a lot of interest because of their wide range of uses, including antibacterial, antifungal, antimicrobial, and anticancer activities. To assess the potential of zinc oxide nanoparticles in developing domains like bioapplications, this thorough investigation offers insights into the shape and structure of ZnO NPs as well as their characteristics and attributes using characterisation procedures. This work is novel because it carefully examines various synthesis techniques for zinc oxide nanoparticles, provides a thorough understanding of their chemical and biological complexities, and investigates how these nanoparticles' special properties can revolutionise this field. Through this investigation, we want to clarify the complexities of synthesis while also illuminating the wide range of uses and constraints of zinc oxide nanoparticles, offering a path forward for further nanotechnology research and development.

Abstract: Despite being natural processes of the Earth’s surface dynamics, mass movements can be accelerated or sparked by human interference. Human activities such as developments in highly susceptible mass movements areas have been the main cause of accidents linked to landslides in Brazilian urban hillsides. In Natal - RN, the existence of areas with high declivity combined with inappropriate human occupation has been making the city vulnerable to stability problems of slopes. In this context, this work aimed to map the risk and analyze situations of hazard, vulnerability, and risk of incidence of mass movements present in São José do Jacó community, in Rocas neighborhood, Natal/RN. In order to map the risk, the methodology proposed by [1] was applied and adjusted to the characteristics of the study area. The mapping results showed that São José do Jacó presented a high degree of risk, ranging from high to very high. The analysis of hazard, vulnerability and risk has made possible to observe the factors that triggers mass movements in the area, among which: steep slopes, disordered cut slopes, dense occupation, inefficient drainage system, septic tanks and cesspools on the edge or in the middle of the talus and low/medium vegetation cover can be identified. The detailed research of the hazard, vulnerability and risk situations found in São José do Jacó community has enabled a better understanding of the area’s aspects, which lead to the obtention of high degree of risk.

Abstract: Study on the elemental composition of nanoparticles is of great importance due to their high mobility in the environment and ability to penetrate into human organism. A global aspect is the transport of nutrient and toxic elements with environmental nanoparticles, which can serve as a carrier for these elements. Nanoparticles in complex polydisperse environmental samples such as dust, volcanic ash, or soil may represent only about thousandths or less of bulk sample. Therefore, their recovery followed by quantitative determination of analytes is a difficult task. A novel technique, sedimentation field-flow fractionation in a rotating coiled column, was applied to the fractionation of urban dust and volcanic ash samples with water being used as a carrier fluid. nanoand submicron particles have been separated, weighted, characterized by electronic microscopy and static laser light scattering, and then quantitatively analyzed by ICP-AES and ICP-MS (after digestion). In urban street dust samples, the elements that may be of anthropogenic origin (Zn, Cr, Ni, Cu, Cd, Sn, Pb) were found to concentrate mainly in <0.3 and 0.3-1 μm fractions. It has been shown that the concentrations of Cr, Ni, Zn, Pb, Sn in the finest fraction (<0.3 μm) of street dust can be one order of magnitude higher than the concentrations of elements in bulk sample and coarse fractions. For volcanic ash samples, it has been evaluated that nanoparticles may concentrate potentially toxic elements of volcanic gases. The concentrations of Zn, Cu, Pb, Tl, Bi, Sn, As, Sb in the size fraction <0.2 μm can be two orders of magnitude higher than the concentrations of these elements in bulk sample. Hence, measuring the total concentrations of elements in dust and ash leads to underestimation of the hazard of these samples. The proposed approach to the separation and quantitative analysis of environmental nanoparticles can be a powerful tool for risk assessment related to toxic elements in dust, ash, and other particulate matter.

Abstract: A hazard and operability study (HAZOP) is a structured and systematic examination of a planned or existing process or operation in order to find and evaluate problems that may represent risks to personnel or equipment, or prevent efficient operation. The qualitative HAZOP uses keywords for generating deviations from safe condition and ensures that appropriate safeguards are in place to prevent accidents. WHIPP or Walkdown Hazard Identification for Plant and Process is a hazard identification technique which can be applied to chemical plants, but with modification can be tailored for many industry types. The method adopts a checklist approach to hazard identification which enables auditors and plant operators to carry out plant walkdowns easily and effectively. But there is a high difference between a qualitative hazard identification method and audit type method since HAZOP is mainly used in a process industry and an audit is mainly used for inspecting the safety management of the industry thus in the WHIPP they used guidewords same as HAZOP uses keywords to identify the hazards and risks associated with the hazards while they perform the walk down in the company and are assessed with a checklist. This paper is the comparison of the two methods to see which is more efficient and which is more reliable in the process industries as well as normal industries.

Abstract: In the context of refurbishment projects, providing a safety and health checklist could assist in reducing noncompliance with health and safety regulations and would lead to improvement in communication between different participants in refurbishment projects. The practical checklist for refurbishment project is developed by revising current demolition checklist since there is no specific checklist applicable for refurbishment work at the moment. To achieve this target, demolition techniques, methods and accident reports on the refurbishment project is critically reviewed and investigated. A semi-structured interview based on reviewed literature and existing demolition checklist is organized which addresses a panel of Malaysian refurbishment experts and workers. The final results are provided by analyzing the response of interviewees in listing the common hazards occurring in the site and their recommendations regarding to appropriate precautions to prevent accidents in work site. Finally, refurbishment checklist is developed based on different categories of work phase, activities, precautionary actions and recommendations in which contents directly extracted from data collection and literature review.

Abstract: Mechanical and chemical hazards are the main hazards to children's toys. The current situation of quality hazards and damage mechanism of children's toys was analyzed and the current standards at home and abroad were introduced. The domestic and foreign recall notification, standard comparison and national supervision were deeply discussed. Researching toys’ potential hazards risk, improving the risk assessment research, standardizing production and marking behavior, and strengthening t consumer education were suggested.

Abstract: The debris flow in Sewanzu gully was located in Heishui county of Sichuan province, which was 5.12 Wenchuan of sichuan earthquake severely disaster. It was large and very likely outbreak, which not only had posed a serious threat to the lives and properties of people, but also affected the reconstruction work going on smoothly. According to the basic features of the valley and the debris flow, the dynamic parameters,such as bulk density,flow rate,flow capacity and sediment flush-out were calculated.And then the hazard of the debris flow was evaluated quantitatively. The results could provide the basis for the governance and disaster prevention and mitigation of the debris flow gully.

Abstract: This paper based on the characteristic of large scale、more Individual project、Operation difficulty in water conservancy and Hydropower Engineering,make a improvement of the original LEC method in order to get the purpose of reduce the risk coefficient. The results show that:the results of the improved LEC method in this paper is more simple and more accurate than the original improved LEC method. Accurate estimation of hazard levels not only can be appropriate to reduce the budget of production units in the construction safety,but also means that the increase of enterprise benefit and social benefit.

Abstract: To identify the component failure propagation path in complex systems, a component failure logical model based on DEVS was established by combining the failure logic principle and DEVS formal specification at the next granularity level of component hierarchy. A series of components failure states define a potential hazard. DEVS has modeling advantages of standardized, hierarchical and modular. Basing on its own characteristics,it can be used to study failure logic modeling techniques of complex systems, model and analyse the scene of the accident process. Therefore, the paper describes syntax and semantics of component failure logic and atomic DEVS, focusing on the implementation mechanism of failure logic using DEVS, the establishment of component state space, the trigger mechanism and the corresponding output in order to establish a component failure logical model based on DEVS. At last, a Wheel Brake System is used to verify the applicability and validity of the model.

Abstract: In steelmaking and casting, there are used, stored and handled chemicals which are risk factors either in the normal operation of the technical plants, or in predictable and unpredictable failure conditions. In the steelmaking and casting plants, the substances and liquids considered risk factors are: methane, oxygen, liquid steel and water used for the cooling system. This paper deals with the risk assessment within the premises of electric steelworks, in predictable failure situations, based on the sheets of assessment and reduction of the risk associated with explosive atmospheres of methane and oxygen, in the presence of high temperatures existing at the electric steelworks.