Dangerous Points Research Articles

Interaction and effects of dangerous and hidden points on firefighter’s health during fire overhaul using the PLS-SEM technique

PurposeThe existence of hidden and dangerous points after the fire leads to loss of command of the rescue teams, casualties, and financial loss. This paper aims to identify these points by taking into account their contributing factors that can help to better manage, prevent and prepare for the risks even after their occurrence.Design/methodology/approachIn this study, the fire overhaul was investigated by identifying the risks of this stage and ranking them in terms of impact. This paper introduces danger points using empirical knowledge (questionnaire) along with theoretical knowledge (literature review) and suggested solutions. Finally, by investigating the dangers and their effects on each other, it introduced three main danger paths. The main problem is the lack of applied knowledge, the relationship between theoretical knowledge at this stage of fire and its application in firefighting operations. To solve this problem, a model was developed to determine the relationships between the effects on firefighters’ health during fire overhaul using structural equation modeling (SEM) in the building. To develop this model, dangerous points were first identified, categorized and weighted, and then the effect of each of these points and their interactions was determined.FindingsThis paper contributes to the literature by identifying hazardous points and investigating their impacts on firefighters’ health using the SEM method. This study identifies 17 points that can be traversed through three paths.Research limitations/implicationsHazardous points could affect the success of the fire overhaul operation. Adopting a flexible model during this stage can enhance safety.Originality/valueThe results of this study can be used to rank and classify fire overhaul hazards in buildings and to increase firefighters’ safety and other related factors.

Multi-field coupling simulation and low cycle fatigue life prediction of turbine blades

Through the finite element analysis, the aerodynamic load and temperature load in the flow field of the turbine blades are studied, and in-depth analysis is carried out. Based on the simulation results in the flow field, a multi-field coupling simulation calculation is performed to determine the dangerous points of the blade during operation. Regarding the blade fatigue life, first, use the Smith-Watson-Topper (SWT) model to predict the blade's low cycle fatigue life, and then take the shear strain range into account, modify the SWT model, use the modified model to predict the blade's low cycle fatigue life, and predict both. The results are compared, and the results show that the revised model prediction results are more accurate.

Identification of Potential Landslide Hazards Using Time-Series InSAR in Xiji County, Ningxia

Potential landslide identification and monitoring are essential to prevent geological disasters. However, in mountainous areas where the surface gradient changes significantly, the leveling effect is not completely removed, affecting the deformation results. In this paper, the SBAS-InSAR and PS-InSAR time-series processing methods were combined to interfere with the SAR image data of the ascending orbit in the southern mountainous area of Ningxia and its surrounding regions. Based on the obtained surface deformation monitoring results and optical images, landslide hazard identification was successfully carried out within the coverage area of 3130 km2 in Xiji County. The results show that the whole study area presented a relatively stable state, most of the deformation rates were concentrated in the range of 0 mm/a to −10 mm/a, and the deformation in the southwest area was larger. A total of 11 large potential landslides (which were already registered potential danger points of geological disasters) were identified in the study area, including three historical collapses. The landslide identification results were highly consistent with the field survey results after verification. The timing analysis of the typical landslide point of the Jiaowan landslide was further carried out, which showed that the Jiaowan landslide produced new deformation during the monitoring time, but it was still in a basically stable state. It can do a good job in disaster prevention and reduction while strengthening monitoring. The results of this study have a guiding effect on landslide prevention and mitigation in the mountainous areas of southern Ningxia.

A Review of Verbal and Written Patient Handoffs Applicable to the U.S. Military's Expeditionary Care System.

Long considered a danger point in patient care, handoffs and patient care transitions contribute to medical errors and adverse events. Without standardization of patient handoffs, communication breakdowns arise and critical patient information is lost. Minimal training and informal learning have led to a lack of understanding the process involved in this vital aspect of patient care. In 2017, the U.S. Army commissioned a report to study the process of patient handoffs and identify training gaps. Our report summarizes that process and makes recommendations for implementation. Scoping literature review of 139 articles published between 1999 and 2017 using PubMed, CINAHL, Cochrane, and Medline databases. Verbal tools for handoffs were evaluated against 12 criteria including patient ID, history, current situation, contingency planning, ability to ask questions, ownership, and read back. Written tools were evaluated against a matrix of 126 casualty/treatment attributes. Among verbal communication protocols, the highest scoring handoff mnemonics were HAND ME AN ISOBAR, IPASS the BATON, and I-SBARQ. Among written handoff tools, the highest scoring documents were the Special Operations Forces (SOF) Mechanism, Injuries, Signs, and Treatment (MIST) Casualty Treatment Card and the Department of Defense (DD) Form 1380 Tactical Combat Casualty Care (TCCC) Card. Four critical process elements for patient handoffs and transfers were identified: (1) interactive communications, (2) limited interruptions, (3) a process for verification, and (4) an opportunity to review any relevant historical data. The findings in this review highlight the need for standardized tools and techniques for patient handoffs in the U.S. Military's expeditionary care system. Future research is needed to trial verbal and nonverbal handoffs under field conditions to gather observational data to assess effectiveness. The results of our gap analyses may provide researchers insight for determining which handoffs to study. If standardized handoffs are utilized, training programs should incorporate the four critical elements into their curricula.

Railway construction site safety hidden danger identification method based on machine vision

In order to achieve accurate identification of safety hazards at railway construction sites, taking a railway engineering project as an example, machine vision technology was introduced to design a method for identifying safety hazards at railway construction sites. In this study, the images of key monitoring areas are first collected, input into the computer, and preprocessed. Then, the scene model of the construction site is constructed through the camera and infrared thermal imaging acquisition equipment, and the image background model of the dangerous area is established by referring to the Gaussian model. Finally, the image carrying the background is input, and the image is matched with the time series. The identification conditions of construction site dangerous areas are set up to realize the identification of hidden danger points in the background of dangerous point image. Comparative experimental results show that this method can improve the identification rate of safety hazards in railway construction sites.

Electrocution of Eagles in Mongolia

Steppe Eagles (Aquila nipalensis) and Golden Eagles (Aquila chrysaetos) are species of conservation and cultural importance in Mongolia. Electrocution at electricity distribution lines is a threat faced by both species across Central Asia. We present the results of power line surveys conducted in the Mongolian steppe region to elucidate temporal patterns of electrocution and specific danger points on power poles for eagles. There was spatial and temporal variation in electrocution rates for Steppe Eagles and Golden Eagles. Autumn surveys across Mongolia recorded the electrocuted carcasses of 18 Steppe Eagles and 9 Golden Eagles. The distribution of electrocutions revealed that Steppe Eagles are mainly killed at power lines in the central steppe zone; in contrast, only Golden Eagles were found at power lines in the southern ‘gobi’ desert zone. Daily surveys conducted for a year at a single power line in the eastern steppe detected 8 Golden Eagles and 6 Steppe Eagles. All Steppe Eagle electrocutions occurred between April and September as they are predominantly summer visitors in Mongolia, whereas six of the eight Golden Eagle electrocutions occurred in winter indicating that Golden Eagles can range over predominantly flat, open steppe landscapes at this time. Significantly more electrocutions occurred at poles with no crossarm mitigation compared to poles with deflectors, deterrents or covers, indicating that mitigation on the crossarm can reduce eagle electrocution rates. Furthermore, the absence of eagle carcasses at poles with crossarm mitigation suggests that crossarms are the main site of electrocution for eagles in Mongolia. Country-scale retrofitting of insulation to crossarms and pole tops significantly reduced eagle electrocution events.

Application of a full-scale strain gauge to study the stress-strain state of structures subjected to the action of a liquid-metal coolant at high temperatures

A technique for studying the stress-strain state of structural elements exposed to an aggressive liquid metal with temperatures up to 500°C was developed. Strain gauges were used to solve the problem installed on the internal and external surfaces of the equipment. The operability of measuring instruments was checked during bench tests under conditions close to operational ones. An algorithm was proposed to determine the stresses at dangerous points of the structure. The developed technique was assessed during tests of a BN-type nuclear reactor.

Residual risk in Automatic Train Protection systems: evaluation and management

The paper on typical rail operation hazards, such as Signal Passed at Danger (SPAD) and Failed Braking Application by Driver (FBAD). The protection against these hazards is normally by Automatic Train Protection (ATP) systems and emergency braking activation, operated by the onboard systems over a certain Minimum Release Speed (MRS). The determination of such speed is a key design parameter related with the achievable performances in terms of safety and capacity. The present research deal with a systematic analysis of the operational conditions potentially affecting the determination of such speed values by modelling the dynamics of the problem taking into account the features of the infrastructures (tracks layout, gradients, etc.), the vehicles (mass, braking performances, etc.) and the geography of signalling and ATP systems themselves. In fact, the position of main signals protecting the dangerous points (switches, level crossings, etc.) emerges as key player, affecting both the design and the operation of the systems.

Stress Characteristics near Wellbore and Prevention Casing Deformation for Fracturing Horizontal Wells

Aiming at the problem that casing deformation can easily occur in tight oil horizontal well fracturing, based on the rock mechanics experiments and probability statistics, the distribution characteristics and law of the near-wellbore stress field of the reservoir in STH M56 were solved and analyzed by using the finite element modeling numerical method. The research shows that (1) the max/min horizontal stress ratio of the M56 tight oil reservoir is 1.2, the difference is less than 8 MPa, and this characteristic condition is more conducive to the formation of complex fracturing network in the reservoir during fracturing. (2) In M56, the Mises stress isoline near the borehole is symmetrically distributed. Stress concentration has four dangerous points (30°, 150°, 210° and 330°); a sector-shaped high dangerous stress zone is formed along the four dangerous points. As the pumping pressure increases, the vertical Mises stress first increases and then decreases, while the horizontal Mises stress first decreases and then increases. The max-Mises stress at the casing wall is linearly and positively correlated with the stress uniformity coefficient. When the pumping pressure is 80 MPa, the Mises stress exceeds the safe pressure limit of the casing. A pumping pressure of 70 MPa fracturing is the safe pumping pressure for the reservoir casing. (3) It is found that the 90° and 270° horizontal fixed plane perforations can avoid the dangerous stress zone, increasing and decreasing the injection flow rate of the fracturing pump step by step ( step pressure ≤ 5 MPa ) at the start and stop stages of fracturing; the control of the pump pressure during the whole process of fracturing is within 70 MPa, which can prevent the casing deformation.

The use of full-scale tensometry for studying the stress state of new power equipment

Creation of the new generation of power equipment (nuclear reactors, gas turbine plants, special power plants) with increased operational parameters and meeting high safety requirements, entails the goal of creating novel domestic methods for determining stresses and strains that occur in the most critical elements during operation of such installations. The new approaches, including the restoration and development of domestic competencies in the creation of means for experimental control of deformations in elements of the equipment at high temperatures are proposed. The results of developing indirect methods providing determination of the deformations at the most critical points of the structure based on solutions of the inverse problems of experimental mechanics are presented. Improved algorithms for processing experimental information and determining strains from measured stresses are considered for the case of inelastic behavior of the structural material in the zones of tensometric measurements. The improved hermetic strain gauges resistant to lead and sodium coolant are proposed for experimental determination of the deformations that occur on the internal surfaces of the liquid metal coolant circulation circuit of new nuclear reactors of BN and BREST types. The results of tests of the developed measuring instruments in liquid sodium medium at a temperature of 540°C during bench tests are presented. In conditions of increased requirements for assessing the effect of the strain gauge creep on the measurement results obtained at high temperatures, a stand design has been developed that makes it possible to determine the boundaries of a possible error at temperatures up to 600°C under dynamic loading of the structure. To determine the stresses arising at dangerous points of the heat exchange equipment of BN type reactors located in inaccessible areas of the inner surface of the facility, an iterative algorithm for solving the inverse problem of thermoelasticity is proposed, using the measured values of stresses and temperatures on the outer surface of the structure. A set of improvements to the traditional method of full-scale tensometric study is proposed proceeding from of the analysis and implementation of the data obtained.

Thermal Protection Mechanism of a Novel Adjustable Non-Ablative Thermal Protection System for Hypersonic Vehicles

In order to improve the thermal protection performance of the active thermal protection system (TPS) based on the spike and jet, an adjustable non-ablative thermal protection system, of which the spike can be rotated in the direction of the free stream, is proposed in this paper. The thermal protection mechanism and the optimal installation angle are analyzed by adopting the numerical method. The results show that the angle of attack has great influence on the peak heat flux of hypersonic vehicles, the dangerous point is on the windward side of the vehicles at the non-zero angle of attack. With the increase in angle of attack, the heat flux of the windward side of the vehicles rises rapidly, leading to the decrease in the global thermal protection efficiency. The adjustable non-ablative TPS in this paper greatly reduces the aeroheating of the windward side through the installation angle between the spike and nose cone, thus improving the global thermal protection efficiency. The optimal installation angle can be obtained by numerical or experimental methods in engineering design, and the difference between the angle of attack and the optimal installation angle is about 2.4° for the proposed model. Therefore, the installation angle can be automatically adjusted based on the angle of attack to achieve the highest thermal protection efficiency.

Fatigue Life Calculation of Tubing for In Situ Drilling Rig

The severe bending strain that the tubing of the in-situ drilling rig is subjected to during the operation under pressure, which exceeds the elastic limit, will cause periodic plastic deformation of the tubing of the in-situ drilling rig, so that fatigue cracks will occur on the internal and external surfaces of the tubing of the in-situ drilling rig and expand rapidly, leading to the greatly shortened service life of the tubing of the in-situ drilling rig. Based on the stress analysis of the dangerous points of the tubing of the in-situ drilling rig, the relationship between the predicted and the standard measured tubing life of the in-situ drilling rig is obtained in this paper. The number of tubing cycles of in-situ drilling rig decreases sharply with the increase of internal pressure. The greater the internal pressure is, the greater the circumferential stress and uniaxial alternating stress are, which causes the number of tubing cycles of in-situ drilling rig to decrease when tubing fails. It shows that the fatigue life of tubing of in-situ drilling rig is significantly affected by internal pressure.

Research on fatigue performance of offshore wind turbine blade with basalt fiber bionic plate

As a new type of inorganic green and high performance fiber material, basalt fiber has broad application prospects in the field of offshore wind power. In order to promote the application of basalt fiber in offshore wind turbine blade, the static tensile test and tensile-tensile fatigue test of basalt fiber reinforced polymer (BFRP) at different stress levels were carried out to obtain the elastic modulus, tensile strength, and SN curve of BFRP. The equivalent model of basalt fiber bionic plate and the finite element model of wind turbine blade were established by Ansys Workbench software. Based on nCode software, the fatigue performance of the offshore wind turbine blade with basalt fiber bionic plate was analyzed and its fatigue life was predicted. The results show that the elastic modulus of BFRP is more than 2.5 times that of glass fiber reinforced polymer (GFRP), and BFRP has good plastic energy dissipation capacity. The equivalent model based on equivalent plate theory is suitable for static and dynamic analysis of basalt fiber bionic plate. The fatigue damage of the wind turbine blade under low wind speed is mainly concentrated in the edge of the blade root, the area where the skin and the web intersect and near the tip of the blade. Under the high wind speed, the fatigue damage covered the whole skin, only slight damage occurred at the trailing edge of the tip. The dangerous point is mainly located near the tip of 50 m–60 m along the span direction. The traditional Miner theory can accurately predict the fatigue life of wind turbine blade, and the fatigue life of the wind turbine blade with basalt fiber bionic plate is 29 years, while the fatigue life of the glass fiber wind turbine blade at the same scale is less than 1 year.

The Numerical Simulation Method of the Slot Crack Groups’ Effect Analysis for Solid Rocket Motor Grain

This study is aimed at the stability and effect of the crack groups in the solid rocket motor (SRM) grain when it was launched at normal temperature. Based on the nearly incompressible viscoelastic finite element method, several cracks were preset in a critical location along with the dangerous point of the back slot. The singular crack elements at the tips of crack groups were established to calculate the J -integral. With the position of the cracks, the J -integral of the various crack tips was, respectively, calculated to prejudge its stability and the group effect. Finally, the experimental measured critical J -integral J IC was compared with the numerical simulation result. The results showed that in the collinear crack groups, the enhancement effect of the main crack was caused by the nearest second crack, and the significant shielding effect of the main crack was occurred in the noncollinear crack groups. Moreover, the experimental result showed that the numerical method had high accuracy.

Gambaran Penerapan Hazard Analisys Critical Control Point (HACCP) Pada Pembuatan Tahu di Home Industri Tahu MD Kampung Sawah Kecamatan Lubuk Basung

Abstract
 Tofu is a food product in the form of soft solids made through the process of processing glycine-type soybeans by depositing protein, with or without the addition of other permitted ingredients. The problems found were during the soaking of soybeans, the water used was cloudy and workers smoked during the tofu printing process. The tofu making process requires the HACCP system to be implemented to be able to control the danger points in each tofu making process. This type of research is descriptive which was carried out at the Home Industri Tahu MD Kampung Sawah, Lubuk Basung District. This research was carried out in December 2021 – Juni 2022 with the research subjects including workers, materials and tools and the object of research includes the tofu making process. The data collection techniques carried out are observations and interviews and are analyzed univariately. The results showed that the hazard analysis in making tofu includes physical, chemical and biological hazards with the most risk categories, namely high contained in the process of cooking, filtering, clumping and printing tofu. Critical control points (TKK) are obtained in 3 tofu making processes, namely the filtering process, clumping and tofu printing. Critical Limits include the absence of sweat splash contamination by workers, workers no longer smoking which can cause the entry of cigarette ash into tofu juice and the use of vinegar acid (CaSO4) according to dosage and needs. Based on the results of the study, it is hoped that the management of the Home Industry knows MD to hold training on the application of HACCP to workers so that workers know and can minimize what dangers can arise during the tofu making process.
 Keyword : HACCP; Tofu Making; and Home Industry

Enzensberger’s Illusions

Enzensberger’s Illusions

APPLICATION OF DIGITAL TWINS IN HIGH PRECISION GEOLOGICAL HAZARD SURVEY AND PREVENTION IN BEIJING

Abstract. Beijing is located in the northwest corner of the North China Plain, with a total area of 16410 km2, of which mountainous area accounts for about 61.3 % of the total area. Due to the complex geological and geomorphological conditions, the development of fault structures, the spatial-temporal uneven distribution of rainfall and the influence of human engineering activities, there are many sudden geological hazards in Beijing, such as collapse, landslide, debris flow and mining collapse. As is known, Beijing is one of the capital cities with most developed sudden geological hazard in the world. With the continuous development of economy and tourism in mountainous and shallow mountain valleys and the further enhancement of human activities, the threat of sudden geological hazard to Beijing's social and economic development will continue to exist. This paper explores the application of digital twin technology in the survey and prevention of geological hazard in Beijing, mainly using tilt aerial photogrammetry, 3D model production, remote sensing interpretation, ground analysis, database management and other methods to carry out high precision survey, mapping and investigation research. Furthermore, we analyze the relevant features of geological hazard hidden danger points, deeply study their dangers, and establish a two-dimensional and three-dimensional information management system for geological hazard in Beijing's mountainous areas. It is proved that the information management system can effectively improve the management and prevention of geological hazard.

Flood Risk Forecasting and Early Warning Technology for Medium and Small Rivers in the Yellow River Basin Induced by Heavy Rain

The Yellow River Basin is one of the important sand-producing and sediment-transporting areas in China, and one of the three most important sand-producing areas in the world. The amount of sand and dust days in the “Three Norths” (Dongbei, Xibei, and Huabei) area has increased, and regional sand and dust storms have occurred frequently. There are generally more serious hidden danger points of debris flow geological disasters in small and medium-sized river basins. The technical achievements of flood risk forecasting and early warning for medium and small rivers in the Yellow River Basin based on rainstorm-induced floods are important technical supports for flood forecasting and early warning for medium and small rivers. Based on this, a case study was carried out on the problems such as the weak forecasting and early warning ability of flood disasters induced by heavy rain and the low accuracy of flood disaster loss assessment in the flood disasters of medium and small rivers, for the reference of relevant personnel.

First insights in perception of feet and lower-body stimuli for proximity and collision feedback in 3D user interfaces

The visual and auditory quality of computer-mediated stimuli for virtual and extended reality (VR/XR) is rapidly improving. Still, it remains challenging to provide a fully embodied sensation and awareness of objects surrounding, approaching, or touching us in a 3D environment, though it can greatly aid task performance in a 3D user interface. For example, feedback can provide warning signals for potential collisions (e.g., bumping into an obstacle while navigating) or pinpointing areas where one’s attention should be directed to (e.g., points of interest or danger). These events inform our motor behaviour and are often associated with perception mechanisms associated with our so-called peripersonal and extrapersonal space models that relate our body to object distance, direction, and contact point/impact. We will discuss these references spaces to explain the role of different cues in our motor action responses that underlie 3D interaction tasks. However, providing proximity and collision cues can be challenging. Various full-body vibration systems have been developed that stimulate body parts other than the hands, but can have limitations in their applicability and feasibility due to their cost and effort to operate, as well as hygienic considerations associated with e.g., Covid-19. Informed by results of a prior study using low-frequencies for collision feedback, in this paper we look at an unobtrusive way to provide spatial, proximal and collision cues. Specifically, we assess the potential of foot sole stimulation to provide cues about object direction and relative distance, as well as collision direction and force of impact. Results indicate that in particular vibration-based stimuli could be useful within the frame of peripersonal and extrapersonal space perception that support 3DUI tasks. Current results favor the feedback combination of continuous vibrotactor cues for proximity, and bass-shaker cues for body collision. Results show that users could rather easily judge the different cues at a reasonably high granularity. This granularity may be sufficient to support common navigation tasks in a 3DUI.

Visualization and Analysis of Safe Routes to School based on Risk Index using Student Survey Data for Safe Mobility

Risk analysis is important in heterogeneous industrial domains to enable sustainable development. Data is the basis for emphasizing the potential risk elements for improving efficiency, quality, and safety. For supplying safe routes to schools based on risk analysis, the risk assessment of routes is one of the widely used and very effective methodologies to filter the most dangerous roads, intersections, or specific points on roads. This paper presents a visualization and analysis of the risk assessment approach based on the risk index model using geographical information, including routes, danger points, and student survey data. The proposed risk index model is used for deriving a risk index based on geographical information, including danger points and a route's path. The model includes an equation to calculate the distance of danger points to the path using the coordinates of each location. The survey data is mainly comprised of route and survey information that is analyzed and preprocessed for the input data of the risk index model. The survey mainly consists of basic information on the route, survey participants, school route information, and school route coordinates. The data is classified into the school route data set and the school route danger points data set, and these values are applied to the analysis and the risk index model. Also, the risk index model is designed and developed through the analysis of routes.