Areas Of Weakness Research Articles

Seismic rehabilitation of RC frames with innovative precast U-shaped UHPC jackets: Experimental evaluation and computational simulation

The rehabilitation of post-earthquake reinforced concrete (RC) frames is crucial for both restoring structural integrity and enhancing seismic resilience against future seismic events. Ultra-high-performance concrete (UHPC) is distinguished by its exceptional strength, crack-control capabilities, ductility, and durability. Despite numerous studies on its use for structural retrofitting, its application in rehabilitating damaged RC frames remains limited. This study introduced a novel precast U-shaped UHPC jacket designed for the post-earthquake rehabilitation of RC frames. The jacketing method promotes composite action in rehabilitated members through lap splicing and dowel bars, complemented by cast-in-place connections using UHPC to minimize splice length and strengthen potential weak areas under external loads. The efficacy of this jacketing approach was rigorously evaluated through cyclic loading experiments on two RC frame specimens. Results indicated that the UHPC rehabilitation method not only recovered but significantly enhanced the seismic performance of the previously damaged frame, improving initial stiffness, yield strength, peak strength, displacement ductility, and energy dissipation capacity. However, the rehabilitated frame showed a reduced yield drift and increased residual displacement compared to the as-built frame. The experimental results also revealed the necessity of accounting for bond slip in structural rehabilitation analysis and design to prevent overestimating lateral stiffness. Furthermore, the study developed a computational model that incorporates flexure, bond slip, and shear responses, aiming to effectively simulate the load-displacement behavior of rehabilitated RC frames with reasonable accuracy.

Palliative Care Knowledge among Physicians in King Abdullah Medical City, Makkah, Saudi Arabia: A Cross Section Study

Aims: To estimate the level of understanding of non-palliative physicians regarding the palliative approach and to identify areas of weakness in their management of advanced terminal symptoms. Study Design: An observational study was conducted among physicians at a single center using a cross-sectional design. Location and Duration of Study: King Abdullah Medical City, Makkah, Kingdom of Saudi Arabia. Methodology: The sample size was determined using ROA software based on the number of physicians. A validated survey was used from a comparable study conducted in Vietnam. The data was transmitted via an electronic iteration of the authorized survey. Statistical significance will be assessed using a significance level of P < 0.05 and a confidence range of 95%. Results: The study included a sample size of 80 individuals, with the highest proportion (37.5%) belonging to the age group of 31-40 years. The findings revealed that 57.5% of the participants have knowledge about comprehensive and appropriate palliative care. The study found significant positive correlations between healthcare provider practices and education (r: 0.360, P <0.001), as well as comprehensive Palliative Care Practices (r: 0.476, P <0.001). A negative correlation was seen between knowledge and belief of end- of-life (r = -0.358, P <0.001). Statistically significant correlations were observed between knowledge of palliative care and age (p =0.028), degree (P <0.001), and clinical practice area (P =0.004). The pain management category showed a significant positive correlation with healthcare providers and practices (r: 0.316, P =0.004). Conclusion: The findings revealed that physicians possessed insufficient knowledge in the areas of pain management and palliative care. Knowledge levels are associated with age, educational attainment, and beliefs about end-of-life care. The study recommended the implementation of additional specialized facilities and the establishment of more efficient palliative care education programs.

Infant Suck Strength Exam: Introduction of an Accessible Clinical Technique for Measuring Infant Suck at the Breast.

One of the core skills required in lactation support is understanding and correcting ineffective or painful breastfeeding. The behavior being corrected, however, occurs inside the infant's mouth, making it difficult to see and assess. When providing care in the field, we use standardized tools and digital suck exams. In research, instruments have been developed to measure infant suck strength with a pacifier, bottle, or at the breast using ultrasound. The aim of this article is to introduce a simple manual clinical technique to identify areas of weakness in an infant's suck and describe one treatment option that can be used to reduce weakness in the identified area. During the Infant Suck Strength Exam, the lactation support provider places a finger on the breast 2 to 4 cm from the edge of the infant's mouth at the upper and lower lip and then at both corners of the mouth, testing the strength of the suck in each of these four areas. To address any specific areas of weakness, the nursing parent can be taught to apply light skin traction back toward the chest wall at the affected area. This engages the suckling reflex and amplifies the strength of the infant's suck in that particular area. The traction applied should not indent the breast but rather just pull back on the skin. It should be applied with enough strength to challenge the infant without pulling the breast out. This is a teaching tool, and is typically only needed for a few weeks before the infant improves their nursing habits.

Identifying failure connection area on wall for deep excavation based on system stiffness influence factor

In this study, a methodology to identify weak or failure connection area on the wall of deep excavation was proposed based on the system stiffness influence factor (IF), which can be beneficially utilized for wall-collapse prevention and forecasting system. Irregular excavation configuration common in urban areas and various weak-connection locations were considered. Three-dimensional finite element analyses with full consideration of actual staged excavation and strut-waler connection condition were performed. It was found that wall deflection and ground movement increased as the location of weak connection became deeper. It was also found that the influence of weak connection on the wall behavior became more pronounced as it located towards the center of the wall. The effects of weak connection on wall deflection were evaluated and quantified using IF. A modification procedure for IF was introduced to consider the effects of depth and horizontal weak-connection locations. The modified IF was adopted to establish a method for quantifying and identifying weak or failure connection area on the wall based on measured wall deflection from field monitoring. Case examples were selected to check the validity of the proposed method. The compared results showed that monitored and predicted locations of weak connection were in close agreement.

Evaluation of user experience and satisfaction with workplace-based assessments (WPBAs) in dental postgraduate programmes.

To explore the experience of and satisfaction with workplace-based assessment tools among dental postgraduate trainees. The cross-sectional study was conducted from March to October 2022 at the Aga Khan University Hospital, Karachi, and comprised all Operative Dentistry, Prosthodontics and Orthodontics postgraduate trainees. A questionnaire with both open-ended and closed-ended questions was used to record the experiences and satisfaction level of the dental residents who had earlier been subjected to workplace-based assessment. Data was analysed using SPSS 20, while thematic analysis was used for open-ended questions. Of the 20 Subjects, 15(75%) were females. Also, 11(55%) participants had received prior training for workplacebased assessment. There were 16(80%) residents who were satisfied with workplace-based assessment tools in the dental residency programme, 15(75%) agreed that the tools improved their clinical skills and helped them identify their weak areas, all the 20(100%) participants said the feedback given to them was constructive, 18(90%) reported that they were allowed to put in their views. However, 7(35%) participants reported that being observed adversely affected their performance. Dental residents generally gave positive feedback related to workplace-based assessment tools in a clinical setting.

Data simulation of the impact of ball strikes on the bottom of electric vehicle battery packs based on finite element analysis

As a key component, electric vehicle battery packs may suffer serious consequences from external impacts, but there is currently a lack of comprehensive data and simulation studies to evaluate the impact resistance of battery pack structures. Therefore, this article establishes a three-dimensional model of the electric vehicle battery pack through finite element analysis method, taking into account the elastic and geometric nonlinear characteristics of the material. In the ball hitting simulation, appropriate impact dynamic loads were selected to simulate the actual response and deformation of the battery pack bottom under impact, in order to ensure the accuracy and reliability of the simulation results. By analyzing the simulation results, the deformation, stress, and strain distribution at the bottom of the battery pack under ball impact were obtained, as well as the related variation patterns. It was observed that the battery pack underwent significant deformation under impact load, and stress concentration also occurred in certain areas. By analyzing the stress and strain distribution obtained, the weak areas of the battery pack can be identified, and corresponding improvement measures can be proposed to enhance its impact resistance and structural strength. These simulation results also provide reference for the optimization design of the battery pack, helping to further improve its overall working performance.

Research on the Reinforcement Characteristics of Thick Cushion Layer and Rigid Pile Composite Foundation

The rigid pile composite foundation method is the most commonly used method for strengthening weak soil foundations. In this method, piles usually need to pass through weak soil layers, and the pile end falls on a bearing layer with good bearing capacity. Under existing technical conditions, the thicker the weak soil layer, the longer the pile body, and the more difficult it is to ensure the construction quality of the pile. In response to this issue, some scholars have adopted the rigid pile composite foundation method with a thick cushion layer for reinforcement treatment. This article uses PLAXIS 3D (V20.04.00.790) software to establish a finite element model of rigid pile composite foundation with a thick cushion layer and simulate the process of foundation reinforcement. The influence of parameters such as thickness, compression modulus, and shear strength index of the cushion layer on foundation settlement and pile–soil stress distribution is studied, and the reasonable range of these parameters is analyzed under the condition of considering reinforcement effect. Through comparative analysis, it can be concluded that for deep and weak soil areas, the thickness of the cushion layer can range from 0.5 to 2.6. The thickness and compressive modulus of the cushion layer have a significant impact on the settlement of the foundation, the pile–soil stress ratio, and the stress of the pile body, while the shear strength index of the cushion layer has a relatively small impact on these parameters. Reasonably selecting the geometric and mechanical parameters of the cushion layer can effectively reduce stress concentration at the pile top and better play the role of the soil between piles.

Changes in Snow Cover and Its Surface Temperature across the Tibetan Plateau Region from 2000 to 2020

Currently, the global climate system is complex and ever-changing, with multiple factors influencing climate change. The Qinghai–Tibet Plateau, known as the “Third Pole” of the Earth, is particularly sensitive to global climate change. Without timely and scientific research on the ecological environment of the Qinghai–Tibet Plateau and without summarizing relevant adaptive strategies, global climate change will impact the sustainable development of the plateau. This study utilized Landsat remote sensing images from 2000 to 2020 to extract the snow cover area and snow temperature of the Qinghai–Tibet Plateau using the snow frequency threshold method. The study analyzed the spatiotemporal characteristics of snow cover and temperature over the 20-year period and investigated some of the climate and topographical driving factors influencing their changes. The results showed that from 2000 to 2020, the permanent snow cover area in the Qinghai–Tibet Plateau region showed a fluctuating decreasing trend, reducing from approximately 12.34 thousand km2 to around 9.01 thousand km2; the permanent snow temperature showed an initial increase followed by a decrease during the same period. The highest annual average snow temperature was approximately −3.478 °C, while the lowest annual average temperature was around −8.150 °C. Over the 20-year period, the snow cover area in the plateau was negatively correlated with temperature and precipitation, while snow temperature was positively correlated with temperature and precipitation. The snow cover in the weak wind areas of the plateau showed a significant reduction. Areas with higher average wind speeds, such as shaded slopes and semi-shaded slopes, had larger snow cover areas. These research findings provide important insights into the protection and management of the ecological environment of the Qinghai–Tibet Plateau.

The Influence of Seasonal Effects on Railway Vertical Track Modulus

Adequate vertical track support is essential for safe and efficient railway operations. Insufficient support leads to distorted track geometry, increased dynamic loads, component stress, poor ride quality, rolling stock damage, and derailment risks. Current inspection practices focus on assessing the condition of the track components and geometry, rather than the root causes of degradation. To improve this condition, this study presents the use of a methodology that utilizes an autonomous vertical track deflection measurement system mounted on a loaded rail car (36 tonnes/axle) to support track maintenance decisions in a heavy haul railroad located in southeast Brazil. The system continuously measured substructure stiffness along the railway line. Over one year, data were collected from over 8000 km of track. The study highlighted seasonal effects on track degradation over time, identifying areas with significant deflections and high deflection rates, which contribute to issues such as differential settlement and reduced lifespan of track components. Additionally, the study revealed seasonal effects, with deflections peaking during wet weather and decreasing during dry cycles. A method to classify weak track areas was developed, facilitating monitoring and enabling more effective maintenance planning, contributing to the reduction of overall track maintenance costs and enhancing safety and operational efficiency.

Horizontal and Vertical Spatial Equity Analysis Based on Accessibility to Living Service Amenities: A Case Study of Xi’an, China

Accessibility is closely related to residents’ well-being and quality of life and is a potential indicator of social equity. This study aims to present a methodology for assessing the combined equity of living service amenities (LSAs) based on accessibility. This study focuses on fourteen types of LSAs in six dimensions and improves the three-step floating catchment area (3SFCA) model by considering the behavioral demand characteristics of different age groups. Taking the main built-up area of Xi’an as an example, the modified 3SFCA model is applied to assess the accessibility of LSAs, and the supply–demand index is used to measure the supply and demand level of the horizontal dimension. Furthermore, random forest regression was used to screen the key socioeconomic indicators affecting the accessibility of LSAs, and then the binary spatial correlation local index was used to reveal the spatial distribution characteristics between LSA accessibility and key socioeconomic indicators in the vertical dimension. Finally, the comprehensive equity of LSAs is evaluated by space superposition. The results showed that there was a serious imbalance between the supply and demand of LSAs in Xi’an’s main built-up area, with polarized oversupply and weak supply areas, especially for accessibility to low-grade LSAs. Accessibility is relatively low for children and young and middle-aged groups, and intergenerational inequalities were particularly pronounced among them. The lower-income group was generally at a disadvantage in accessing the high-demand amenities, and those who resided in affordable housing in the periphery of the city were more likely to face social exclusion. This study emphasizes the importance of distributing urban resources equitably among different social groups, which can help decision makers achieve a balance between horizontal equity and vertical equity in the allocation of urban LSAs and promote spatial equity and sustainable social development.

Urban policy responses to climate hazards in Addis Ababa, Ethiopia

Urban in-migration, high birth rates and unchecked development are driving the continued growth of African cities. Much of this urbanization occurs in informal settlements, where unplanned growth exacerbates the impacts of climate hazards. Our paper explores the challenges faced by urban planners seeking to address climate change threats in African cities. Focusing on Addis Ababa, we conduct a robust policy analysis of urban government response. Our main finding is that Addis Ababa’s environmental challenges are primarily a result of urban development and inadequate planning and policy enforcement. Environmental challenges are exacerbated by rapidly intensifying climate impacts, but not driven by them. Improved city-level policy responses can potentially mitigate many of Addis Ababa’s current environmental challenges and prepare the city to weather future ones. We highlight four areas of policy weakness: (1) ineffective or absent policies concerning green space; (2) the exclusion of informal settlements from ongoing resilience planning efforts; (3) limited public trust and transparency; and (4) a lack of coordination across the multiple agencies in Addis charged with planning. Holistic, multi-stakeholder planning is inhibited by a lack of collaboration, limited stakeholder participation, and a reluctance to engage in productive dialogue. Resolving all four issues will only occur with sustained increases in social trust, expertise, governance capacity and capital.

Evolution of light deflection and shadow from a gauge-potential-like AdS black hole under the influence of a non-magnetic plasma medium

We investigate the light deflection in the weak field approximation from the accelerating charged AdS black hole. For this purpose, we apply the Gauss–Bonnet theorem to calculate the light deflection in the weak field area and use the Gibbons–Werner approach to analyze the optical geometry of the accelerating charged AdS black hole in the non-magnetic plasma absence/presence of a non-magnetic medium. We also represent the graphical behavior of the light deflection angle w.r.t. the impact parameter. We also compute the light deflection angle using Keeton and Petters approximations under the impact of accelerating charged AdS black hole geometry. Furthermore, by using the ray-tracing approach, we determine the shadow in the non-magnetic plasma presence and also demonstrate that graphical shadow has an impact on the gauge potential, non-magnetic plasma frequencies and charge.

Research on the evaluation and optimization path of long-term care insurance policy in Chengdu and Chongqing--Based on the PMC index model

This paper applies the quantitative method of policy text to construct an evaluation index system based on the PMC index model to quantitatively evaluate the long-term care insurance policies introduced in Chengdu and Chongqing since 2017. The study finds that long-term care insurance policies have dilemmas in terms of policy subjects, policy areas, and policy tool combinations. The direction of future policy optimization should strengthen collaboration between departments; focus on the development of weak policy areas; and optimize the combination of policy tools.

A proposed feedback model for the objective structured clinical examination (OSCE) in health and medical education

What was the educational challenge? The objective structured clinical examination (OSCE) is used extensively in health and medical education to assess clinical competence. While OSCEs are not primarily designed for individual feedback, they provide an opportunity to generate meaningful and constructive feedback that students can use to reflect on areas of weakness (and strength). The most timely and effective way to incorporate individual feedback following a summative OSCE continues to be explored. What was the solution? This paper describes a novel OSCE feedback model which uses readily available summative assessment data to calculate 10% index scores. This provides information about relative station difficulty and relative individual student performance. How was the solution implemented? An individualised feedback report was provided to every student after the OSCEs. This enables identification of stronger and weaker performance areas and composite skills, which can be utilised by all students to direct future learning. What lessons were learned that are relevant to a wider global audience? Providing timely, individual actionable feedback to every student following a summative OSCE is possible without impacting the examination process or examiner burden. What are the next steps? A study is planned to determine the utilisation of this feedback by students and it’s impact as a qualitative self-assessment exercise.

Readiness for clinical practice: Self-perceived confidence of final year dental students in Turkey - A multi-institutional study.

The primary aim of undergraduate dental education is to prepare dental students for independent dental practice and to enable them to provide safe and effective dental care. This study aimed to investigate the self-perceived preparedness of senior dental undergraduate students in Turkey. Purposive sampling was used to recruit final-year dental students from 10 dental institutions offering undergraduate dental programs in Turkey. Student preparedness was assessed using a previously validated dental preparedness assessment scale based on 50 items encompassing core clinical skills, cognitive attributes, and behavioral skills. The research instrument was then translated into Turkish. The R statistical environment for Windows was used for the data analysis. Responses were provided by 272 students (156 women and 116 men; 57% and 43%, respectively) across 10 different universities. The mean score of the participants was 75.68 with slightly higher scores for men compared to women (77.35 vs. 74.46 respectively). However, independent t-tests showed that the scores did not differ significantly between women and men. This study evaluated the self-perceived preparedness for dental practice of final-year students from 10 universities in Turkey. Although the results showed several areas of weakness, the scores of self-perceived preparedness of Turkish students were comparable to those reported in Europe and Asia. These findings can be used to inform future curriculum development to support students in consolidating their learning in perceived areas of weakness.

Exploring the Nexus: Homeschooling and Library Engagement in Connecticut

ABSTRACT In the dynamic landscape of education, homeschooling continues to offer a compelling alternative to traditional schooling. Homeschool numbers surged through the pandemic and have not decreased to pre-pandemic levels. This study examines the shared connections between homeschooled families in Connecticut and local public libraries by looking at how home educators use library resources and participate in library programming; and examining how Connecticut libraries perceive and respond to the diverse needs of homeschooling communities. Based on 2 Connecticut statewide surveys, one sent to public librarians and another to homeschoolers, the study sought to identify areas of strengths, weaknesses and disconnects in the homeschool community and public library relationships in Connecticut. Both qualitative and quantitative data was collected and reviewed to identify potential improvements to the evolving role of libraries in supporting alternative education pathways, and the potential for an infusion of public library support from the homeschool community.

Raw material design, sintering temperature optimization and development mechanism investigation of self-foaming porous bricks with high solid waste addition

In recent years, the contradiction between the huge production of municipal sludge and industrial residue and the shortage of landfill space has driven the exploration of novel effective methods to valorize these solid wastes. In this research, blast furnace slag (BFS), municipal sewage sludge (MSS) and kaolin are combined innovatively as precursor materials to manufacture self-foaming porous bricks, and the sintering behavior of bricks under different BFS doses and sintering temperatures is deeply studied to reveal the development mechanism. The results indicate that the formation of Fe2O3-hematite during sintering leads to a reddish-brown appearance of the bricks, while the generation of CaAl2Si2O8-anorthite with lower melting points helps to enhance the vitrification process. Besides, the increase in BFS dose or sintering temperature has significant impacts on the evolution of the brick physicochemical properties. This occurs because changing the dose of BFS or sintering temperature can obviously regulate the internal morphological characteristics of bricks, such as particle consolidation, pore size and structural compactness. Among them, large-sized pores are considered as the weak areas of mechanical strength, which is also the responsibility for the worst compressive strength of bricks sintered at 1300 °C. Finally, under the optimal sintering conditions of 15 % BFS dose and 1250 °C sintering temperature, the compressive strength, water absorption, apparent porosity, bulk density and linear shrinkage of the resulting brick are 65 MPa, 0.45 %, 2.50 %, 2.34 g/cm3 and 19.56 %, respectively. Overall results demonstrate that using recycled sludge and waste slag in brick manufacturing can produce products with desired performance, providing preferable solutions for solid waste valorization and sustainable brick production.

Effect of recycled concrete aggregate size on physical and mechanical properties of eco-friendly-self-compacting concrete

In recent years, the rapid increase in population and building demand across the world leads to significant deterioration or reduction of natural resources. Meanwhile the huge amounts of waste from the demolition of buildings and concrete structures in the landfill space become a serious ecological and environmental problem. The recovery of aggregates from recycled concrete for the formulation of new concrete would contribute to reducing the depletion of natural resources and therefore integrate into the context of sustainable development, because there are several socio-economic advantages. The objective of this possibility of using aggregates from recycled concrete mixes. We have established a comparison between the physical and mechanical behavior of SCC based on RCA (Recycled Sand: SR 0/3 and Recycled Gravel RG: 3/8 and 8/15) and that of SCC based on natural aggregates (NA) on fresh support and hardened state. Additionally, Non-Destructive Testing (NDT) methods were conducted in this research to obtain more information about the properties of the studied SCC. The results of the tests on fresh SCC meet the recommendations of the French Association of Civil Engineering (AFGC). The physical and mechanical behavior of SCC-RS is relatively weak compared to SCC-NA/RG. This is directly related to the high absorption capacity of the aggregates (depending on the size of the aggregates) and the poor quality of the mortar attached to the aggregates, which can create areas of weakness in the concrete structure. From the regression results, it was found that there is a direct correlation between the physical and mechanical properties of different concretes indicated by the higher values of R-squared (R2 = 0.92).

Conocimientos sobre astronomía en estudiantes de educación secundaria en Colombia: una evaluación desde la fundación AstrodidaXis

An exploratory analysis of the astronomical knowledge of 241 secondary education students in Boyacá, Colombia, members of the AstrodidaXis network, was carried out using a qualitative, hermeneutic and exploratory methodology. This analysis was developed through a questionnaire aligned with the learning standards of the Ministry of National Education, as a basis for identifying areas of strength and weakness in astronomy concepts. The need to improve the understanding of various topics was highlighted, including the fundamental forces of the universe and the origin of chemical elements from the teaching of astronomy. These findings contributed to the construction of projections for the research and development of astronomy teaching in Boyacá, promoting the scientific, technological and social progress of the region.

Chemical heterogeneity size effects at nanoscale on interface thermal resistance of solid–liquid polymer interface via molecular dynamics simulations

The shrinking size of integrated chips poses thermal management challenges. Understanding the size effect of chemical heterogeneity on solid–liquid interfacial thermal transfer is essential for heterogeneous chip design, yet the underlying mechanisms remain lacking. The present work used the liquid n-alkanes as the thermal interface material between solid platinum substrates. To characterize chemical heterogeneity, periodic solid surface patterns composed of patches with alternating solid–liquid affinities were constructed. By using non-equilibrium molecular dynamics simulations, we investigated the size effect of chemically heterogeneous patterns on interfacial thermal resistance (ITR) at the nanoscale. At larger heterogeneity sizes, i.e., larger patch sizes, most alkane molecules directly in contact weak interaction patches cannot interact with strong interaction patches due to long atomic distances. In the case of alkanes in contact a cold substrate, alkanes in contact weak interaction patches transferred thermal energy to the substrate at a lower rate than those in contact strong interaction patches. The different rates resulted in the higher temperature of alkanes in contact weak interaction patches than those in contact strong interaction patches and, therefore, a larger disparity between temperature jump at the strong interaction areas and that at the weak interaction areas. The non-uniformity of temperature jump distribution increased ITR when compared to the heterogeneous surface system characterized by a smaller patch size with a more uniform temperature distribution in the plane perpendicular to the heat flux direction. In addition, the classical parallel thermal resistance model predicted ITR accurately for the heterogeneous surface systems with small size patches but overestimated overall thermal resistance.