A new method for risk assessment of pillar recovery operation

Safe pillar recovery operations can result in better miner safety and more efficient recovery of ore reserves. Several parameters influence on safety of pillar recovery operation. Each of these parameters is able to reduce safety of operation and cause to detrimental effects during pillar recovery. In this paper, by emphasizing ground control aspects, the most important technical parameters influencing on safety of pillar recovery are introduced and the role of them is described. Then, a new method is presented by combining all of these parameters to assess overall risk of pillar recovery operation in pre-developed room and pillar mines. The proposed method involves calculating the PR-Risk (Pillar Recovery-Risk) indicator. PR-Risk value is between 0 and 100 that based on overall risk of pillar recovery operation divides into four categories: low, medium, high, and very high. PR-Risk is an important indicator for predicting the safety of pillar recovery operation and based on it decision can be made about the safe implementation of operation. Finally, the overall risk of pillar recovery operation in main panel of Tabas Central Mine, located in the mid eastern of Iran, is assessed by use of proposed method in this paper. PR-Risk value in this panel was obtained 51 that show overall risk of operation is medium. Moreover, based on individual assessment of parameters, for the safe implementation of operation and reduction of related risks, reinforcement of roof prior to beginning of operation and partial pillar extraction have been suggested as the most efficient controlling measures.     

Development and application of a video-mosaic survey technology to document the status of coral reef communities

The recent decline in the condition of coral reef communities worldwide has fueled the need to develop innovative assessment tools to document coral abundance and distribution rapidly and effectively. While most monitoring programs rely primarily on data collected in situ by trained divers, digital photographs and video are used increasingly to extract ecological indicators, provide a permanent visual record of reef condition, and reduce the time that divers spend underwater. In this study, we describe the development and application of a video-based reef survey methodology based on an algorithm for image registration and the estimation of image motion and camera trajectory. This technology was used to construct two-dimensional, spatially accurate, high-resolution mosaics of the reef benthos at a scale of up to 400 m². The mosaics were analyzed to estimate the size and percent cover of reef organisms and these ecological indicators of reef condition were compared to similar measurements collected by divers to evaluate the potential of the mosaics as monitoring tools. The ecological indicators collected by trained divers compared favorably with those measured directly from the video mosaics. Five out of the eight categories chosen (hard corals, octocorals, Palythoa, algal turf, and sand) showed no significant differences in percent cover based on survey method. Moreover, no significant differences based on survey method were found in the size of coral colonies. Lastly, the capability to extract the same reef location from mosaics collected at different times proved to be an important tool for documenting change in coral abundance as the removal of even small colonies (<10 cm in diameter) was easily documented. The two-dimensional video mosaics constructed in this study can provide repeatable, accurate measurements on the reef-plot scale that can complement measurements on the colony-scale made by divers and surveys conducted at regional scales using remote sensing tools.     

Measurement and management of hospital waste in southern Iran: a case study

One of the requirements for development of human societies is the establishment of new healthcare centers. A variety of wastes are generated in healthcare centers depending on the type of activities. This study was conducted to identify, measure and manage different types of hospital wastes as a case study in a hospital located in southern Iran. For this purpose, a questionnaire was initially designed and distributed among the relevant experts to survey the current trend of waste management in the hospital in terms of waste collection, storage and disposal. Afterwards, the hospital waste was sampled during two seasons of fall and winter. The samples were weighted for seven consecutive days in the middle of each season. Approximately, 10 % of the total waste bags per day collected round the clock were selected for further analysis. The obtained results indicated that infectious-hazardous and pseudo-household wastes were, respectively, about 3.79 kg/day/bed, 1.36 kg/day/bed and 2.43 kg/day/bed of the total generated waste in the hospital. As the research findings suggest, proper separation of infectious and pseudo-household wastes at the source would be an essential step towards mitigating environmental and health risks and minimizing the cost of the hospital waste management.     

Indicator-Based Approach for Assessing the Vulnerability of Freshwater Resources in the Bagmati River Basin,Nepal

To assess the vulnerability of water resources in the Bagmati River Basin in Nepal, this paper adopts an indicator-based approach wherein vulnerability is expressed as a function of water stress and adaptive capacity. Water stress encompasses indicators of water resources variation, scarcity, and exploitation and water pollution, whereas adaptive capacity covers indicators of natural, physical, human resource, and economic capacities. Based on the evaluation of eleven indicators, which were aggregated into eight vulnerability parameters, an increasingly stressful situation and lack of adaptive capacity became evident. Considerable spatial variation in indicator values suggests differential policy options. While the northern parts need attention to reduce pollution loading and conserve vegetation cover, the southern parts need improvements in physical capacity, i.e. water infrastructures. The comprehensive and easily interpretable findings of the study are expected to help decision makers reach sound solutions to reduce freshwater resources vulnerability in the Bagmati River Basin, Nepal. With its inherent flexibility, the approach has demonstrated its potential for application in different times and areas for monitoring and comparison purposes.     

Challenges of higher education related to e-learning in developing countries during COVID-19 spread: a review of the perspectives of students,instructors, policymakers,and ICT experts

The COVID-19 pandemic brought about many critical issues in all aspects such as economy, environment, health, and lifestyle, but people always try to find some response to crisis in different conditions. E-learning is defined as an elaborate response aiming at continuing education during the COVID-19 pandemic. It seems that developed countries have established and adjusted their technological infrastructures for the transition from a face-to-face education to a digital one. In contrast, developing countries were not completely prepared for this transition. Improper and deficient technological and practical fundamentals have been causing problems for all students, instructors, and other involved individuals. Therefore, we reviewed the challenges that have arisen from e-learning during the COVID-19 outbreak in different parts of tertiary education focusing on underprivileged countries.

     

Degradation–environment–society spiral: A spatial auto‐logistic model in Thailand

In this contemporary interpretation of the widespread land degradation problem in Southeast Asia, it is hypothesized that spatial interplay of environmental and socioeconomic predictors determines the occurrence of land degradation. Village surveys, remote sensing and spatial auto‐logistic modelling of the relationship between degradation and land use dynamics in Lam Phra Phloeng watershed of Thailand enabled 80.2% of land to be classified correctly in terms of the presence or absence of erosion and explained 53.2% of the total variation. Cultivation and dependence on agriculture for livelihood positively and significantly affect degradation. Lack of access to institutional credit and land titles significantly increased the probability of occurrence of degradation. On the other hand, education and social cohesion are negatively associated with the occurrence of degradation. The Relative Operating Characteristic (ROC) curve was used to measures the performance of the model. The calculated area under the curve (0.879) suggests that significant predictor variables in the model can be confidently used to forecast the likelihood of occurrence of degradation and thus to identify priority areas for intervention. Policies to reduce land degradation should include measures to reduce pressure on the land, including alternative income sources. Policies could mobilize capital to invest in encouraging nature‐based tourism and other off‐farm income options.     

Risk analysis for oil & gas pipelines: A sustainability assessment approach using fuzzy based bow-tie analysis

Vast amounts of oil & gas (O&G) are consumed around the world everyday that are mainly transported and distributed through pipelines. Only in Canada, the total length of O&G pipelines is approximately 100,000 km, which is the third largest in the world. Integrity of these pipelines is of primary interest to O&G companies, consultants, governmental agencies, consumers and other stakeholder due to adverse consequences and heavy financial losses in case of system failure. Fault tree analysis (FTA) and event tree analysis (ETA) are two graphical techniques used to perform risk analysis, where FTA represents causes (likelihood) and ETA represents consequences of a failure event. ‘Bow-tie’ is an approach that integrates a fault tree (on the left side) and an event tree (on the right side) to represent causes, threat (hazards) and consequences in a common platform. Traditional ‘bow-tie’ approach is not able to characterize model uncertainty that arises due to assumption of independence among different risk events. In this paper, in order to deal with vagueness of the data, the fuzzy logic is employed to derive fuzzy probabilities (likelihood) of basic events in fault tree and to estimate fuzzy probabilities (likelihood) of output event consequences. The study also explores how interdependencies among various factors might influence analysis results and introduces fuzzy utility value (FUV) to perform risk assessment for natural gas pipelines using triple bottom line (TBL) sustainability criteria, namely, social, environmental and economical consequences. The present study aims to help owners of transmission and distribution pipeline companies in risk management and decision-making to consider multi-dimensional consequences that may arise from pipeline failures. The research results can help professionals to decide whether and where to take preventive or corrective actions and help informed decision-making in the risk management process. A simple example is used to demonstrate the proposed approach.     

An integrated Shannon's Entropy–TOPSIS methodology for environmental risk assessment of Helleh protected area in Iran

This study aims to use integrated Shannon's Entropy-TOPSIS methodology for environmental risk assessment of the Helleh protected area in Iran. In this research, first, with regard to field visits, interview with natives of the area, and investigation of the environment of the study area, the risks existing in the region were identified. Then, for final identification of the risks, the Delphi method was applied. Analysis and prioritization of risks of the area of Helleh were performed by multi-criteria decision-making methods of Shannon's Entropy and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). In this research, risks were assessed by three criteria of severity, probability of occurrence, and vulnerability. Twenty six of the risks were identified which were specified in two groups, natural events and environmental risks. The environmental ones were classified into four groups: physicochemical, biological, social-economic, and cultural. Results of the research showed that the construction of the Rayis-Ali-Delvari Dam at the upper part of the study area threatens the wetland. Water supply for the dam 75?km away from the area with concession of 0.9999 holds the first priority of risk-generating factors. Of the managerial workable solutions suggested controlling the risks, the stopping of the pumping of water from the wetland and observation of hunting season length and permissible type and number of hunting in the area can be mentioned.     

Examining motorcyclists' postcrash impressions: A qualitative study

Objective: Motorcycle-related crashes and injuries continue to be of great concern in Iran. This study seeks to explore how motorcyclists' perspectives and impressions of a crash are shaped and influence their future riding behaviors.

Methods: This was a qualitative study conducted in 3 major cities in Iran between March 2011 and February 2012. Participants included 31 male motorcyclists, of whom 22 participated in 4 focus groups and 9 in in-depth interviews. Findings were derived through the thematic method of analysis.

Results: Six delineated themes suggest different factors that influence riders' postcrash impressions. These include (1) opposing reactions from family and peers postcrash; (2) the motorcyclist's perception of his or her ability to handle risky road situations; (3) risk-taking attributes; (4) perceived responsibility in meeting family needs; (5) the severity of the crash-related injury; and (6) elapsed time from the crash experience.

Conclusions: Riders' postcrash impressions were formed by the opposing reactions of their family and peers to the crash experience (i.e., the index crash); the personality of riders, including being overconfident and a risk taker; familial obligations; feeling traumatized by the crash; and passage of time. These formed their perceptions, feelings, attitudes, and thoughts about the index crash.

These findings are an important step in understanding how perception and attitudes of motorcyclists are shaped and how these influence their future riding behavior. The needs for interventional studies to assess the effectiveness of road safety risk reduction programs aligned with the riders' degree of postcrash impressions are discussed.