Safety Class Research Articles

New Swedish Design Method for Concrete Pavements

A new concrete pavement design method is currently introduced in Sweden. It consists of two parts: (i) computations of subgrade and base distresses and (ii) computations of concrete pavement distresses. To eliminate the difference between concrete and asphalt pavement design, the first part is carried out with equal requirements, in the same manner, and with the very same computer program. The computer run also provides a coefficient of subgrade reaction that is used as input in the second part. For this part, the American FE program ISLAB2000 is used to compute stresses – both traffic and thermal stresses, simultaneously – in various locations of the concrete pavement slab. Contrary to previous Swedish tradition, both bottom-up and top-down cracking are considered in the analysis of the computations. For the pavement designer, the division into two parts will not be visible. She will use the same user-friendly computer program (that previously has only been used for flexible pavement design) for both pavement alternatives. It is the authors’ hope that the selection of pavement solution for a certain case will be dependent solely on technical and economical factors and not on tradition and intensive advertising. The new design method includes a novelty concerning safety philosophy. The safety margin should be obvious and transparent and determined by the client in co-operation with the designer by selecting an appropriate safety class that is dependent on the economical consequences of a pavement failure but independent of material in the wear layer.

Glucagon-like Peptide-1 Receptor Agonists in the Management of Diabetic Retinopathy.

Glucagon-like peptide-1 (GLP-1) receptor agonists are a family of drugs, most well known by the third-generation once-weekly subcutaneous semaglutide, that act on the incretin pathway of metabolic, hormonal signaling to modulate pancreatic insulin release, gastric emptying, energy intake, and subjective feelings of satiety. This class of drugs' efficacy and safety in the treatment of type 2 diabetes and obesity have been demonstrated across multiple large randomized controlled trials. These data have propelled GLP-1 receptor agonists to ubiquity in diabetic management and weight loss therapy, leading them to be frequently encountered in ophthalmic practice. The effect of GLP-1 receptor agonists like semaglutide on diabetic retinopathy (DR) is at this point unclear; some studies indicate a worsening of DR with the initiation of GLP-1 agonists, especially semaglutide. Overall, the macrovascular reduction of cardiovascular and stroke risks from GLP-1 receptor agonists should be prioritized over the potential microvascular progression of DR, as long as the patient is regularly followed by ophthalmology.

Seismic Fragility Analysis for Probabilistic Risk Assessment of Underground Structures

ABSTRACT The seismic assessment of urban tunnels, crucial for city infrastructure, particularly shallow tunnels in transportation systems, is vital for risk mitigation. This study focused on the Ahwaz twin tunnels in Iran, using incremental dynamic analysis and probabilistic risk assessment. Evaluating seismic behavior through 15 earthquake records, the study generated fragility curves for operational, minor, moderate, and extensive damage states. Results indicate a 99.5% probability of operational limit at a PGA of 0.35 g, with seismic risk assessment aligning with safety class 3 of the Swedish Transportation Administration.

Make the Right Call: formative evaluation for a water safety programme for adults in Western Australia.

Preventing drowning in adults is a complex, multifaceted injury prevention issue. The adult drowning rate in Australia is continuing to rise. In 2023, more than half of those who drowned were aged over 45 years. While there has been a call for robust, evidence-informed drowning prevention interventions across the life course, evidence of evaluated, drowning prevention programmes for adults is lacking. For more than a decade, drowning prevention researchers and practitioners in Western Australia (WA) have worked in partnership to design and evaluate evidence-informed programmes. This paper describes formative research to develop 'Make the Right Call' (MTRC), an adult water safety programme in WA. A staged, mixed-methods, formative evaluation was undertaken to inform the design of MTRC. The approach involved cluster analysis of coronial data 2008-2018 (n = 93), interviews with adults aged 45-64 years (n = 10) and 65 years and older (n = 15), theory mapping, survey design, content and face validity testing of a baseline questionnaire with content experts (n = 11) and a refined instrument to collect knowledge, and data on norms and water-based activity. The subsequent MTRC programme comprised a media campaign, community swimming and safety classes, lifejacket trade-in, subsidised first-aid training and community education. The results of each stage informed the design and evaluation of a new evidence-informed and theory-driven drowning prevention programme for adults aged 45 years and older, delivered by the peak drowning prevention agency in WA, Royal Life Saving Western Australia. An investment in mixed-methods research by the partnership added rigour and credibility to the programme and evaluation design. To the best of our knowledge, this is the first adult water safety programme to apply a theory-driven, evidence-informed approach to its development, implementation and evaluation. The partnership was vital in maximising and accelerating the acceptable transfer of results to enhance knowledge creation and, ultimately, the design of the MTRC drowning prevention programme.

Assessment of Power Equipment Operational Safety in the Sustainable Management of Residual Lifespan

Introduction. Ensuring the safe operation of energy facilities is a critical issue at all life cycle stages. It is associated with the adoption of management decisions when rescheduling and assessing the remaining resources, which are made based on a comprehensive assessment of the technical condition of the equipment, taking into account the economic efficiency and environmental requirements for further operation, which is the basis for technical and economic assessments. Aim and tasks. This study aims to develop a technical and economic assessment of the safe operation of power equipment to ensure sustainable management of the remaining service lifespan. Results. An algorithm for assessing pipeline system elements by the coolant environment is proposed, which allows for the pipeline load and changes in erosion and corrosion caused by coolant movement. It was proposed that the equipment be systematised by safety class and coolant. When conducting a technical and economic assessment, these parameters and the costs of extending the service life and upgrading the existing equipment were considered in the standard calculations of a certain type of equipment. For this purpose, mathematical models for calculating the residual life for each type, obtained and confirmed based on empirical studies, are proposed. Research findings into ensuring the reliability and safety of operation with various heat carriers have shown that it is necessary to consider low-cycle and high-cycle loads and erosion processes. It was found that the erosive wear rate is 0.3-0.4 mm/year for bending sections of the main circulation pipeline, where maximum loads occur relative to low-cycle and vibration loads, and the stress is 212.5 MPa when assessing the residual life of 7 years. Conclusions. The cost-effectiveness of reassigning the service life is reasonable, as it does not require additional investment in upgrading or replacing equipment subject to annual technical diagnostics. The systematisation of pipelines, improved codifiers, lifespan assessment models, and algorithms for evaluating the remaining life under various loadings enhance the regulatory framework for safe nuclear power plant operations and support technical and economic evaluations for extending their lifespan.

Classification of Histamine Content in Fish Using Near-Infrared Spectroscopy and Machine Learning Techniques

Near-infrared (NIR) spectroscopy has emerged as a popular technique for assessing food quality due to its advantages over complex chemical analysis methods. However, the application of NIR spectroscopy for evaluating fish quality based on histamine content has not been extensively explored. This study investigates the use of NIR spectroscopy in combination with machine learning (ML) techniques to classify fish samples into two safety classes, Safe and Unsafe, based on their histamine content. A comprehensive NIR dataset comprising 11,360 spectra collected at eight distinct positions within the fish body was obtained from 284 fish samples of mackerel, tuna, and pompano species. ML experiments were conducted to classify fish samples based on whether their histamine content exceeded the permissible limit of 100 ppm. To address class imbalance and optimize ML models, various data pre-processing and feature extraction techniques as well as ML algorithms were explored. The results demonstrated that utilizing NIR data specifically obtained from the tail’s flesh, a specific location within the fish, yielded superior models for fish safety classification. A feature extraction method employing pre-processed NIR spectra and their second derivatives, combined with an optimized convolutional neural network architecture, outperformed traditional ML classifiers with an accuracy of approximately 93%.

ToxEraser cosmetics: A new tool for substitution, towards safer cosmetic ingredients

Cosmetic ingredients of choice are those appropriate for a specific commercial use and deemed safer than existing alternatives. In the LIFE VERMEER project (https://www.life-vermeer.eu/), the ToxEraser Cosmetics software was developed as a platform under which an ingredient is presented with a list of potential substitutes, from an archive of 2233 items. Key information about the safety of each item concerns: (a) the risk assessment addressed by seven regulatory and other specialized European-US authorities; (b) the safety class emerging from the systematic evaluation and integration of each authority’s assessment. Read-across analysis makes the substitution possible even when the ingredient is not included in the archive. The list of alternatives can be extended or reduced flexibly, since the commercial use of cosmetics is dictated by attributes indicating progressively detailed and hierarchically related categories. Finally, the identification of significant validated structural alerts for endpoints of interest serves in detecting which part of the structure is associated with certain hazardous properties. This tool will be joined with VERMEER Cosmolife, the other tool for cosmetics developed as part of the VERMEER project. ToxEraser offers a systematic, flexible approach to explore safer cosmetic substitutes, acknowledging the sources of evidence produced by VERMEER Cosmolife, offering a forward-looking tool for the cosmetic sector. More in general, the novelty is the shift to in silico models, not only to assess possible concern associated with a substance, but also to move towards safer alternatives.

Analysis of Diesel Fuel Production by Environmental Safety Class

Analysis of Diesel Fuel Production by Environmental Safety Class

Comparative study on the performance of butt fusion-welding processes for nuclear safety class large-diameter thick-walled PE pipes

New technologies in polymer synthesis and pipe extrusion equipment have led to the commercialization of high-performance, large-diameter, thick-wall high density polyethylene (HDPE) pipes. They have been used in the field of seawater transport and cooling to replace metal pipes, due to their advantages of high corrosion resistance and extensibility. Connection of HDPE pipe is important as it determines the safety of the entire piping system. Butt fusion welding is commonly used for HDPE pipe connection but may cause the formation of weak points in the welded joints, interfering the reliability of the pipeline system in the application of nuclear power plants. At present, there is a lack of research on evaluating the performance of welded joint for large-diameter thick-wall HDPE pipes made by butt fusion-welding. The purpose of this study is to investigate the influence of three different butt fusion-welding processes, i.e., single low pressure (SLP), single high pressure (SHP) and dual low pressure (DLP), by evaluating the performance of their welded joints, including characterizing tensile strength, extensibility, crystallinity and hardness. In specific, a thick-wall HDPE pipe with OD of 812.8 mm and wall thickness of 74 mm which is certified for nuclear safety class was used for study. Representative specimen from the outer, middle and inner part across the wall of the main pipe body and welded joints were taken for testing. Different test methods and specimens were designed to assess the feasibility of evaluating the welding performance from different welding process. The results showed that the mechanical properties of different locations of the welded joints were different, and the tensile strength and fracture energy of the middle part of the joint were lower than that of the inner and outer parts, which could be caused by the difference in the crystallinity and thickness of the melting zone influenced by welding processes, as can be seen from the analysis of DSC test and morphology observation. Hardness testing was conducted on the section of the welded joints, and it revealed that the micromechanical properties of the welded joints in the region of the heat-affected zone were enhanced significantly, which may be due to the annealing effect caused by welding process. In summary, The DLP process resulted in the best extensibility of the welded joints among three processes, suggesting that the joining pressure from welding process plays an important role in affecting the extensibility of the welded joints.

A comprehensive framework for identifying safety-related and ageing sensitive sscs in low power nuclear research reactor

This work aims to establish a novel approach for the selection of structures, systems, and components (SSCs) important to safety and vulnerable to ageing degradation for low-power research reactors. For this purpose, the framework developed combines the Preliminary Risk Analysis (PRA) technique to categorize SSCs into four different safety classes, and Ageing Failure Mode and Effect Analysis (AFMEA) technique to find out ageing failure modes related to a specific SSC and evaluate them according to the Risk Priory Number (RPN). The intersection of the PRA and AFMEA outcomes then yields a list of SSCs that are both important to safety and strongly ageing sensitive, making it possible to optimize the selection process of SSCs to be prioritized in further preventive maintenance, periodic testing, and inspection activities. The present paper also conducts a case study to apply the proposed methodology to the Brazilian IPR-R1 TRIGA nuclear research reactor. The selected SSCs were then both AL and SS fuel rods from the reactor core, stainless steel pipe, thermocouples, pressure indicators, and water level indicators from the primary circuit, and power monitoring channels, radiation monitors, and cooling water temperature channels from the controlling system. Moreover, the approach was also able to identify SSCs that are important from a safety perspective but are not ageing sensitive (reactor tank and control rods) and components that are not important to safety but are strongly ageing sensitive (pipe filters). These findings may further serve as input for the comprehensive safety assessment conducted during the Periodic Safety Review of the facility.

Promoting Retention of Native American Nursing Students: Insights From a Qualitative Study.

This qualitative study aimed to identify effective retention strategies for Native American nursing students. Native Americans are underrepresented in nursing and health education programs, comprising only 1.3 percent of the nursing workforce in the United States. A basic qualitative design grounded in self-determination theory was used to solicit narrative accounts from 12 Native American nursing students. Semistructured interviews revealed three themes: nursing program experience, methods to enhance persistence, and hindrances to persistence. Social support emerged as a critical factor, with participants emphasizing the significance of cultural awareness activities, safety classes, and celebrations fostering a sense of belonging. The study found that social support, financial aid, and cultural awareness are essential for Native American nursing students to succeed. Limited resources and online learning challenges are barriers that need to be addressed. Tailored support systems, financial assistance, and culturally responsive education can enhance retention and success rates.

Psychological safety among K‐12 educators: Patterns over time, and associations with staff well‐being and organizational context

AbstractPsychological safety is a psychosocial construct that reflects an individual's perception of social risk in the work environment, and is related to employee performance and well‐being, including job satisfaction and burnout. Psychological safety remains relatively understudied among educators, including its patterns over time and relationships with other aspects of the school environment. This study explored patterns of psychological safety over 4 years among 769 staff at 20 rural K‐12 schools, before and during the COVID‐19 pandemic, and the associations of these patterns with work‐associated well‐being and organizational context outcomes. Repeated measures latent profile analyses identified a 3‐class solution of stable‐high (51.0%), stable‐medium (44.8%), and dynamic‐low (4.2%) psychological safety classes. Those in the stable‐high class had consistently better outcomes, including less burnout and greater self‐efficacy, and better perceived organizational context and climate, compared to other classes. Among educators, psychological safety is generally stable, and reliably differentiates other important outcomes. Interventions fostering greater psychological safety may improve perceptions of the school environment and reduce burnout.

Teorijska analiza niskozapaljivih i ekološki prihvatljivih smjesa ukapljenog naftnog plina i tetrafluoretana kao hladila

Liquefied petroleum gas (LPG), like other hydrocarbon gases, has good thermo-physical and ecological properties, but its high-flammability has limited its direct use in refrigeration applications. Therefore, this paper investigates the thermodynamic performance of low flammable and ecological-save mixtures of LPG and tetrafluoroethane refrigerant in a refrigeration system. The computational results of global warming potential (GWP) and low flammability limit shown that the blends with 50 – 90 % LPG contents have GWP below 750 and fall within the lower flammability safety class of which five were selected for further analysis. The results showed that the thermal conductivity and the refrigerating effects produced by the selected blends are greater than those of the reference refrigerant (R134a). Also, the selected blends exhibited appropriate lower pressure ratio, discharge temperature and specific power than R134a refrigerant. Four of the blends required low power input and exhibited higher coefficient of performance which are clear indication that they are more energy efficient than R134a in the refrigeration systems.

Flow boiling heat transfer coefficient and pressure drop of R448A inside various multiport tubes: An experimental investigation and correlation assessment

R448A, a safety class A1 a-zeotropic refrigerant blend with a GWP of 1390, is considered an efficient and environmentally friendly substitute for R404A in direct-expansion commercial refrigeration systems. Herein, we experimentally investigate the flow boiling heat transfer and pressure drop of R448A inside a multiport mini-channel tube. The experimental ranges of mass flux and heat flux are 100–500 kg/m2s and 3–15 kW/m2, respectively, and they cover the entire quality range at three different saturation temperatures of 3, 6, and 10°C. Three different test tubes are utilized in this study to evaluate the effect of tube geometry on the heat transfer, and their diameters range from 0.831 to 1.14 mm. The results show that mass flux has favorable effects on the heat transfer coefficient and pressure drop, while heat flux has a favorable effect on the heat transfer coefficient at low mass fluxes. As the saturation temperature decreases when the mass flux is high, the heat transfer coefficient and pressure drop increase. The tube with largest perimeter but the smallest hydraulic diameter has the highest heat transfer coefficient under the low mass flux condition. Heat transfer coefficient and pressure drop experimental data were compared with the models in literature, and the results of our statistical assessment indicate that the pure fluid model modified to account for the mixture effect produces the best results. Meanwhile, most pressure drop models produce reasonably good predictions. Additionally, a new correlation is proposed to predict the heat transfer coefficient in practical applications.

Application of the MELCOR for Fusion Code to the Transient Accident Analysis of the IFMIF-DONES Test Cell

According to the European Fusion Roadmap, to demonstrate the feasibility of fusion energy, it is necessary to build a comprehensive database of materials properties to be used in future fusion power plants. This is the objective of the IFMIF-DONES facility, which will drive a deuteron beam on a liquid lithium target to produce high energy neutron fluxes for irradiating candidate fusion materials. Among the several ongoing activities in the frame of the EUROfusion Early Neutron Source Work Package (WPENS) project, deterministic accident analyses play an important role, since they help identifying a set of reference accident scenarios and related safety class components. Some of these scenarios are being studied with the MELCOR-fusion code, an integrated engineering code which is able to perform thermal-hydraulic transient calculations. In this work, the MELCOR-fusion code has been applied to two potential accident scenarios involving the degradation of the primary lithium loop of IFMIF-DONES. A rupture in the Quench Tank and a break in the inlet nozzle to the Target Vacuum Chamber were postulated as the two initiating events followed by a lithium spill into the Test Cell room. The purpose of this study was to obtain different key metrics, such as the maximum pressure and temperature loads reached in the TC room, the amount of the leaked lithium mass, and the time for lithium solidification. The computed results will help identify the safety requirements to be applied to the final design of the TC room.

Enhancing Safety Education Through the Looking Glass: Acceptance of Augmented Reality

This study explores the acceptance of augmented reality (AR) in safety classes using the Technology Acceptance Model (TAM). Participants from safety classes were exposed to AR-based activities, and their perceptions of AR's usefulness and ease of use were measured through surveys. The findings reveal that participants found AR highly useful in enhancing safe learning experiences, visualizing safety procedures, and facilitating engagement. Participants also reported that AR applications were intuitive and user-friendly. The study supports the TAM model, indicating that perceived usefulness and ease of use strongly influenced participants' attitudes and intentions toward AR. Educators should prioritize emphasizing usefulness and ease of use to promote successful integration of AR in safety education.

Corrosion Detection and Surface Repair with Coatings on Condensate Storage Tanks Internal Surfaces

In the Nuclear power plant Krško, there are two single hull condensate storage tanks with floating diaphragm each containing up to 757 m3 of demineralized water. The main purpose of these two storage tanks is to provide a capacity of cooling water for cooling the reactor coolant system via steam generators with the use of auxiliary feedwater pumps. This is a very important function from the safety point of view and that is the reason that both storage tanks are listed as safety class 3 components. It is also possible to fill up the condensate system if other means are not available. Condensate storage tanks are subject to periodic testing and periodic inspections to determine the condition of the components. Both tanks are in operation since the start-up of the powerplant, are located outside, and are exposed to different degradation processes. There was a concern that the tanks are leaking because there were often small puddles of water near the tanks. There were no changes in the levels of tanks. The design of tanks is a single hull, so there is no indication if a small leak is present.In the outage 2018, both tanks were emptied and examined with NDE methods to find any corrosion damage of bottom plates and any untight spots on adjacent welds.The article is about the NDE methods that were used (Magnetic Flux Leakage, Ultrasonic and Vacuum Box inspection) to determine the condition of the floor plates and adjacent welds as well as the process of internal surface reparation with coatings. Process of coatings qualification for use in safety class components is also explained: dedication process for material up-grade from non-safety related to safety-related because CY tank linings are classified as safety-related according to RG 1.54, rev 2 and corresponding ASTM standards and NEK technical specification SP-A5001. All activities for surface repair with coatings shall comply with safety-related requirements. Also, extensive immersion tests with selected and specially defined parameters were performed in NEK chemical laboratory in order to select the most suitable coating system for surface repair of CY tank floor lining. Further details concerning immersion tests are presented below.

Research on construction site violation monitoring platform with target detection

This mainly describes the construction site supervision platform design purpose, determine in different areas of internal detection and target detection of site violations in the supervision of the link, should be done to visualize the market site standard model, early warning type violation of work and safety class risk hidden danger, real-time monitoring of the site. With this as the basis condition, the systematic structure design of the supervisory platform is launched, and the intelligent voice recognition technology and in-depth learning technology of monitoring images are used to establish a sound design of this system, which maximally meets the requirements of construction site violation monitoring and supervision.

Reliability Assessment of NPP Safety Class Equipment Considering the Manufacturing Quality Assurance Process

Quality and safety are intensely related and go hand in hand. Quality of the safety-grade equipment is very important for the safety of a nuclear power plant (NPP) and achieving production goals. During manufacturing of plant components or equipment, deviation from the design might occur at different stages of manufacturing for various reasons, such as a lack of skilled manpower, deviation of materials, human errors, malfunction of equipment, violation of manufacturing procedure, etc. These deviations can be assessed cautiously and taken into consideration in the final safety analysis report (FSAR) before issuing an operating license. In this paper, we propose a Bayesian belief network for quality assessment of safety class equipment of NPPs with a few examples. The proposed procedure is a holistic approach for estimation of equipment failure probability considering manufacturing deviations and errors. Case studies for safety-class dry transformers and reactor pressurizers employing the proposed method are also presented in this article. This study provides insights for probabilistic safety assessment engineers and nuclear plant regulators for improved assessment of NPP safety.

Skin cancer screening and sun safety education program for high school students in southern California.

e22505 Background: Decreasing unprotected exposure to ultraviolet (UV) radiation during childhood can significantly decrease the risk of developing skin cancer as an adult. School-based sun safety curricula have demonstrated efficacy in teaching young adults about the harms of prolonged, unprotected UV exposure and have been effective in increasing safety practices. This project provided a 50-min sun safety curriculum to high school students at a public high school in San Diego, CA just prior to the summer break in 2022. The curriculum addressed skin cancer risk factors, skin protection methods, the benefits of limiting lifetime UV exposure, and methods for performing a skin self exam. The study objective was to assess sun safety knowledge before and after the class, and measure behavior changes three months thereafter when students returned from summer break. Methods: The sun safety classes were taught in groups of 40-60 students across six class periods in June 2022. Students were asked to complete an anonymous pre-participation online survey assessing their knowledge of common skin cancer types and skin cancer risk factors. Students were taught the curriculum over 45 minutes with 5 minutes reserved for questions. Two follow-ups surveys were conducted with the students, one at the end of the class period and a second follow-up three months later. Follow-up surveys assessed retention of knowledge and changes in sun safety behavior. Students had the option of providing a cell phone number so they could be contacted to participate in the second follow-up survey. Results: The curriculum was taught to nine classes of approximately 300 students in a single day across six class periods. A total of 206 students completed the pre-participation survey. At the first follow-up, 95.1% of students completed the post-participation survey and students showed significant improvement in knowledge of common skin cancer types (12.6% pre-participation to 68.9% post-participation), skin cancer risk factors (11.2% pre-participation to 16.8% post-participation), and skin cancer prevention methods (22.8% pre-participation to 45.9% post-participation). For the second follow-up, 128 students provided contact information and the survey had a response rate of 71.5%. After 3 months, students demonstrated retention of knowledge of skin cancer types and risk factors. A majority (87.2%) of students indicated that their use of sunscreen had increased and 57.4% indicated that their use of sun protective barriers had increased over the summer because of this course. Conclusions: This pilot course demonstrates that targeted sun safety education for teenagers before summer break can significantly increase sun safety awareness, adoption of protective behaviors, and knowledge about skin cancer. Such an intervention can promote skin cancer awareness at a young age where behavior changes can decrease lifetime risk of skin cancer.