Editorial

Editoria

An alternative approach to assessing feasibility of flushing sediment from reservoirs

Effective parameters on feasibility of sediment flushing through reservoirs include hydrological, hydraulic, and topographic properties of the reservoirs. In this study, the performances of the Decision tree forest (DTF) and Group method of data handling (GMDH) for assessing feasibility of flushing sediment from reservoirs, were investigated. In this way, Decision tree Forest, that combines multiple Decision tree, used to evaluate the relative importance of factors affecting flushing sediment. At the second step, GMDH deployed to predict the feasibility of flushing sediment from reservoirs. Results indicate that these models, as an efficient novel approach with an acceptable range of error, can be used successfully for assessing feasibility of flushing sediment from reservoirs

Texas LPG fire: Domino effects triggered by natural hazards

© 2018 Institution of Chemical Engineers On February 2007, a massive fire in a propane de-asphalting unit in an oil refinery in Texas, USA happened due to liquid propane release from a cracked pipe in a control station injuring four people, damaging extensive equipment, causing significant business interruption, and resulting in more than $50 million losses. The accident was triggered by a natural hazard: freezing of piping at a control station caused an inlet pipe elbow to crack, which in turn, led to the release of high-pressure liquid propane which was rapidly ignited. In addition, there were two near-miss events due to potential domino effects. In fact, the accident could reasonably have resulted in much more severe consequences due to the exposure of large butane storage spheres and chlorine containers, increasing the possibility of a catastrophic domino effect. This paper develops a Natech (natural hazard triggering technological disasters) risk assessment methodology that relies upon Bayesian network capabilities and takes into account the potential Natech domino effects. The methodology is implemented in the intended refinery and mathematically graphically represents the dynamic cause–effect relations between units involved in the scenario, and handles uncertainties among the interactions. In addition, the methodology can provide a risk value for the entire scenario that can be used further for risk-based decision making

Investigation of background signals caused by cosmic muons in SiPM and light guides

SiPM is often used to detect a small number of photons produced by very weak radiations. A light guide is usually used to connect this detector to the test space or a scintillator. This research investigated the scintillation of glass and PMMA materials in light guide and epoxy resin in the top window structure of SiPM. The amount of this scintillation is relatively determined by simulation and experimentally measured. Cosmic rays and other energetic particles emitting photons in these structures can leave a significant background error in some experiments if a standard scintillator is not used in the detector structure

Lightweight tubular fiberboard: Effect of hole diameters and number on panel properties

Special tubular fiberboard with a density of 550 kg/m3 was manufactured using the round rods for creation of the holes. Physicomechanical properties of tubular fiberboard (6, 8, 10, 12 (mm)) with various hole diameters and number of hole (0, 1, 2 and 3 in a constant cross section) were evaluated. The surface layers density, especially on top of the holes, considerably elevated with increasing the hole diameter. This did create higher bending properties as well as higher internal bond and surface soundness. The structure of webs between the holes, when the holes’ number increases, were predominant factor influencing the panel properties. Weak and loose web structure were obtained by increasing the holes’ number from 1 to 3 within a constant cross section (50 mm × 16 mm) that was due to the less transferred fiber during pressing in the webs’ sections. A corresponding comparison of panel properties with those in American and European standards presents that the minimum requirements according to most of the standards (ANSI A208/2, EN 14755, EN 312/P2 and EN 622-5/P1) were obtained

Review of Geochimical, Isotopic and Fluid Inclusions Studies in Ramand Region (Qazvin Province)

Ramand copper deposit is an example of vein-bearing deposits with volcanic host located in the Urumieh-Dokhtar zone. The deposit host is an Eocene volcanic sequence and the main host’s rock is the rhyolite mineral. The main minerals are chalcopyrite, pyrite, covellite and natural gold; and the tailings minerals include quartz, calcite and sericite. The average grade of gold in silica veins is 133.5 ppb, the average grade of copper is about 3.5% and the average grade of molybdenum is 135 ppm. Quartz-sulfide hydrothermal veins contain biphasic fluid-rich fluid inclusions and monophasic fluid-rich fluid inclusions. The homogenization temperature ranged from 73 to 307 ° C with an average of 141 ° C and in all samples, homogenization was carried out through the liquid phase and salinity variations ranged from 1.75 to 4.74 with an average of 3.65 wt% NaCl equivalent. Quartz and calcite oxygen isotope values range between 4.4 to 9.4 per thousand. Isotopic data indicate that the ore-generating fluids in the Ramand ore deposit have relatively low salinity and atmospheric-magmatic origin. According to this study, Ramand’s mineralization range is the result of hydrothermal activity in the area where mineralization with simple mineralogical characteristics has occurred in siliceous veins and sub-veinsO depósito de cobre de Ramand é um exemplo de depósitos contendo veias de origem vulcânica localizado na zona de Urumieh-Dokhtar. O depósito é uma sequência de origem vulcânica do Eoceno e a rocha principal encontrada na área é o riolito. Os principais minerais são calcopirita, pirita, covellite e ouro natural; e os minerais de rejeitos incluem quartzo, calcita e sericita. O teor médio de ouro nas veias de sílica é de 133,5 ppb, o teor médio de cobre é de cerca de 3,5% e o teor médio de molibdênio é de 135 ppm. As veias hidrotermais de sulfeto de quartzo contêm inclusões fluidas ricas em líquidos bifásicos e inclusões fluidas ricas em líquidos monofásicos. A temperatura de homogeneização variou de 73 a 307°C com uma média de 141°C e em todas as amostras, a homogeneização foi realizada na fase líquida e as variações de salinidade variaram de 1,75 a 4,74 com uma média de 3,65% em peso de NaCl equivalent

Evaluating the effects of climate on weathering processes of rocks based on Peltier models in Kermanshah province

Weathering is a result of physical, chemical and biological factors, all of which affect the rocks but do not cause Material Handling. The existence of pores and crevices and cracks in the rocks expose the rocks to physical and chemical attack, gradual wracking and being weathered. This study has been based on Louis Peltier’s models in which two mean annual temperature and precipitation variables are used. Peltier identified seven models using these two variables which can describe different types of weathering phenomena. Among these models, two models related to weathering regimes and morphogenetic regimes were evaluated in case of Kermanshah province and the regimes related to each station were determined from the related diagrams. Climate data such as mean annual temperature and precipitation and eight synoptic stations which had appropriate data and statistical length were taken from meteorological organization and then were recorded in a database in GIS environment for studying and zoning of the weathering status and geomorphological regions in Kermanshah. Then, the regimes relating to each station were determined from Peltier models after evaluation of temperature and precipitation processes in the study area which were recorded in the database after giving weighted value to them and then the related maps were generated in ARC map environment. The obtained results showed that most parts of Kermanshah province are semi-arid regions. Chemical weathering along with glacial action to moderate chemical weathering take place in in Kermanshah province in terms of weathering status.Keywords: Weathering regimes, Peltier model, morphogenetic regions, Kermanshah

Re-evaluation of coastal cultural heritage resources : case study of North Carolina southeastern coastal region

Humans have had a long history of interconnectedness with the sea and ocean due to the use of natural resources available in the coastal areas. These interactions have influenced the natural landscape and played a crucial role in the formation of coastal cultural heritage. Coastal cultural heritage, a continuum of land and sea, is an important part of our cultural resources in the coastal areas. Presently, coastal cultural heritage has not been well-integrated into coastal management plans as a cultural resource. the values of cultural heritage have theoretically been recognized in benefiting people and its role in sustainable development. However, the qualitative and comparative analysis of coastal management experiences show that many valuable cultural heritage assets have been overlooked as resources in coastal management schemes. Acknowledging the significance of cultural heritage in Brunswick Country coastal area, the current study address three topics: 1) assessment of the impact of natural and environmental factors on coastal cultural heritage and identifying the heritage items that have been marginalized for variety of different reasons; 2) considering a new evaluation of a selected marginalized cultural heritage (fishing cultural heritage) and assessing the role of cultural heritage for fishing communities wellbeing; and 3) finally exploring the feasibility of developing a cultural tourism in Brunswick County directed at fishing communities. The study applies a multidisciplinary approach for data collection, analysis and evaluation purposes. A synthesis approach is applied and data from different sources on cultural and archaeological resources, and natural-environmental factors are compiled. ArcGIS software is used for analyzing data and creating risk maps for cultural heritage. In addition, several interviews and photo elicitation methods are used for understanding the viewpoints of local fishing communities regarding their cultural heritage resources. Content analysis, a series of graphs and quantitative analysis are applied to understand the state of cultural tourism in Brunswick County on fishing communities. The result of the first part of study shows that there are several sites that are in potential risk zones. However, more site-specific data are required for better assessment. The second section concluded that fishing communities respect their material culture. There are sites, buildings and objects related to fishing that are of sociocultural significance for fishing communities in Brunswick County. However, many of these items are suffering lack of attention and also abandonment. The study on tourism revealed that although there is interest in visiting fishing heritage, lack of information and proper publicity on fishing cultural heritage resulted in overlooking fishing cultural heritage sites as a tourist attraction. The study concludes that a balanced integrated and interdisciplinary evaluation of different cultural resources can enhance our understanding of the holistic values of cultural heritage as a resource to benefit people. Passing this understanding to managers and policy makers will help to improve future planning aimed at sustainable development. Better decisions require concrete evidence that demonstrates how re-evolution of cultural capital in regards to different aspects of communities and society can lead to outcomes that improve human well-being in the short and long term. This evidence should combine natural-environmental, cultural, economic, and social data

Multi-objective Optimization of Firefighting Strategies in Process Plants

Ideal firefighting strategies at process plants would include simultaneous suppressing and cooling of all the burning and exposed units, respectively, if firefighting resources are sufficient. As a result, the primary fires can be contained and their escalation into secondary fires via domino effect can be prevented until the fires are fully extinguished. However, when the number of burning units to suppress and exposed units to cool exceeds the firefighting capacity of a process plant, it is not feasible to conduct an ideal firefighting. Consequently, the plant owners need to conduct an optimal firefighting to address the following question: When all the burning and exposed units cannot be considered in firefighting, which ones should be prioritized and included in firefighting so that the risk of fire propagation in the plant can be minimized? For process plants that are close to other land-use developments (residential communities, infrastructures, etc.), conducting an optimal firefighting can become more challenging as it should minimize not only the risk of domino effect within the plant (onsite risk) but also risks posed to the nearby land-use developments (offsite risks). In the present study, considering onsite and offsite risks that may arise from domino effects in process plants, a methodology is developed based on goal programming – a multi-objective optimization technique – for identifying optimal firefighting strategies. Given limited firefighting resources, the developed methodology helps determine which units to suppress and which ones to cool in order to minimize as many risks as possible

An Approach to Update the Failure Rates of Safety Barriers Based on Operating Experience

Hazardous events in process plants like the leakage of dangerous substances can result in severe damage, and such an event is often defined as the TOP event of a fault tree analysis (FTA) in a quantitative risk analysis. The TOP event probability can then be calculated if the basic events probabilities are provided. These probabilities are often determined based on generic reliability data which do not necessarily reflect the operational and environmental characteristics of a plant of interest. This paper presents an approach based on Bayesian network (BN) analysis to explicitly include experience data collected during the plant operation to make the generic probabilities more plant specific. The approach is illustrated via a pressure vessel containing a toxic substance in an Ammonia production plant. In this case study, the failure rate distribution in the BN is updated as the new information becomes available during plant operation. The results show that the suggested approach effectively reflects the operating experience of a specific plant.publishedVersio