Search Results (50,557)

Oblique detonation waves (ODWs) are hypersonic combustion phenomena induced by oblique shock waves. When applied to air-breathing engines, ODWs offer high thermal cycle efficiency, adaptability to a wide range of flight Mach numbers, and the advantage of a short combustion chamber, making them highly promising for hypersonic propulsion applications. Despite numerous numerical studies on the heat release and multi-wave flow mechanisms of ODWs, practical applications of oblique detonation engines (ODEs) remain limited due to several technical challenges. These challenges include generating the required high-velocity test environments, achieving effective fuel and oxidant mixing, and measuring the flow field structure in hyper-velocity and high-temperature flows. These limitations hinder the development of ODEs, underscoring the importance of experimental research, particularly for understanding the initiation and propagation mechanisms of ODWs. One of the primary experimental techniques involves inducing oblique detonation using high-velocity models. This method is extensively used to study the initiation process, shock structure, initiation criteria, and ODW propagation. It is advantageous because the state of the experimental mixture is controllable, and the model state can be precisely measured. This paper reviews studies on oblique detonation induced by hyper-velocity projectiles, presenting advances in experimental methods, detonation wave structures, unsteady processes, and initiation characteristics. Additionally, we discuss the deficiencies in existing studies, noting that the current measurement methods fall short of the requirements for observing the ODW initiation process, propagation process, and fine structure. The application of advanced combustion diagnostic techniques and the exploration of the relationship between initiation processes and criteria are crucial for advancing our understanding of ODW initiation and stabilization mechanisms. Finally, we summarize the current state of experimental facilities and measurement techniques, providing suggestions for future research on the measurement of shock waves and chemical reaction zones. Full article

Efforts have been made to improve gender diversity in the built environment professions. This sector continues to experience growth restrictions due to skill shortages. Some progress has been made at the entry level; however, the retention of women in professional roles within this sector continues to present a challenge. Support for women during maternity, upon return to work and while working with family has been identified as a barrier to women’s progression in this sector. Professional bodies are uniquely placed to support their female members. Therefore, this study had two aims: to examine current professional body support for members during and after maternity leave and to examine the experiences of female professionals, who have taken maternity leave whilst holding membership in a built environment professional body. This study adopted an embedded, mixed-method design, using a secondary, qualitative data set to augment the primary, quantitative data set, within one phase. Surveys were distributed directly to professional bodies and to professionals via social media (LinkedIn). The survey of the professional bodies identified a varied approach to maternity support. The professional member survey identified a lack of awareness of available support, and generally the need for more support during maternity and on return to work. In summary, professional bodies in the built environment could improve maternity support for members by improving communication and achieving parity in support across the various disciplines. Full article

This study examined local communities’ perceptions of mangroves in coastal southeastern Cuba. A variety of methods were employed, including mixed and structured questionnaire surveys, interviews with key informants, and document reviews. Data were gathered from 334 respondents living in communities adjacent to four mangrove social–ecological systems (SESs). The analysis focused on five variables: community use of mangrove resources, ecosystem services, threats to the ecosystem, management activities, and social–ecological relationships. To qualitatively assess the influence of social–ecological relationships and governance, a matrix was created based on anthropogenic activities identified by respondents and their perceptions of ecosystem services. A Spearman’s rank correlation analysis was performed between demographic variables and identified mangrove uses. The Kruskal–Wallis test was used to compare the frequency of mangrove uses and the perception of ecosystem services among the studied areas. The results indicate that, while local people recognise the uses and ecosystem services of mangroves, they do not rely on them for their livelihoods. Perceptions of ecosystem services vary significantly depending on the occupation of the respondents and the locality. They also showed moderate to full awareness of management responsibilities and activities at each site. The most commonly identified threats were climate change, drought, and deforestation. Three types of social–ecological relationships were identified based on the characteristics of the communities, their economic activities, and their impacts on the mangroves: urban–industrial, rural–agricultural, and rural–agricultural/tourism. Based on the results, recommendations are made for ecosystem governance in the southeast of Cuba. Full article

Agri-food supply chains have the potential to make a significant contribution to achieving sustainable development goals through ongoing improvements in their configurations. A range of strategic, tactical, and operational level decisions pertaining to the design and operation of sustainable supply chains have been studied in the extant literature. However, investigations into the adoption of multi-modal transportation as a strategic decision in the context of agri-food supply chains operating in constrained environments are limited. As such, in this study, the adoption of bi-modal transportation for the domestic vegetable supply chain in a developing country context under certain constraints was examined. A mixed-integer linear programming model was developed to determine the volume and direction of the product flow to achieve the minimum total food-miles and smallest emissions footprint. As a case study, a Sri Lankan mainstream vegetable supply chain was used to investigate the applicability of a combination of truck and railway modes to transport vegetables from farms to retailer locations via economic (consolidation) centers. The adoption of a bi-modal transportation structure demonstrated the potential to reduce food miles by 32%, transportation costs by 36%, contributions to global warming potential by 35%, and empty truck hauls by 38%, compared to a structure with truck-based, uni-modal transportation. Full article

Rayleigh–Bénard convection is a fundamental fluid dynamics phenomenon that significantly influences heat transfer in various natural and industrial processes, such as geophysical dynamics in the Earth’s liquid core and the performance of heat exchangers. Understanding the behavior of conductive fluids under the influence of heating, rotation, and magnetic fields is critical for improving thermal management systems. Utilizing the Boussinesq approximation, this study theoretically examines the nonlinear convection of a planar layer of conductive liquid that is heated from below and subjected to rotation about a vertical axis in the presence of a magnetic field. We focus on the onset of stationary convection as the temperature difference applied across the planar layer increases. Our theoretical approach investigates the formation of parallel rolls aligned with the magnetic field under free–free boundary conditions. To analyze the system of nonlinear equations, we expand the dependent variables in a series of orthogonal functions and express the coefficients of these functions as power series in a parameter $ϵ$. A solution for this nonlinear problem is derived through Fourier analysis of perturbations, extending to O(${ϵ}^8$), which allows for a detailed visualization of the parallel rolls. Graphical results are presented to explore the dependence of the Nusselt number on the Rayleigh number (R) and Ekman number (E). We observe that both the local Nusselt number and average Nusselt number increase as the Ekman number decreases. Furthermore, the flow appears to become more deformed as E decreases, suggesting an increased influence of external factors such as rotation. This deformation may enhance mixing within the fluid, thereby improving heat transfer between different regions. Full article

Artificial intelligence (AI) has emerged as an effective solution to alleviate excessive carbon emissions in sustainable building projects. Although there are numerous applications of AI, there is no state-of-the-art review of how AI applications can reduce net-zero carbon emissions (NZCEs) for sustainable building projects. Therefore, this review study aims to conduct a systematic literature and science mapping review of AI applications in NZCEs for sustainable building projects, thereby expediting the realization of NZCEs in building projects. A mixed-method approach (i.e., systematic literature review and science mapping) consisting of four comprehensive stages was used to retrieve relevant published articles from the Scopus database. A total of 154 published articles were retrieved and used to conduct science mapping analyses and qualitative discussions, including mainstream research topics, gaps, and future research directions. Six mainstream research topics were identified and discussed. These include (1) life cycle assessment and carbon footprint, (2) practical applications of AI technology, (3) multi-objective optimization, (4) energy management and energy efficiency, (5) carbon emissions from buildings, and (6) decision support systems and sustainability. In addition, this review suggests six research gaps and develops a framework depicting future research directions. The findings contribute to advancing AI applications in reducing carbon emissions in sustainable building projects and can help researchers and practitioners to realize its economic and environmental benefits. Full article

Positive nursing practice environments benefit clients, professionals, and institutions, specifically for professionals, by improving professional visibility, recognition, retention intentions, well-being, commitment, job satisfaction, and reducing stress and burnout. Clients experience better quality care, safety, satisfaction, engagement, and fewer care omissions. Institutions favored reduced absenteeism and turnover, improved efficiency, lower costs, and better health outcomes. This study aimed to document the development of the “Program to Promote Positive Nursing Practice Environments” and analyze expert perceptions to reach a consensus. Using a two-round modified online Delphi technique with 22 experts, we examined perspectives on the program’s goals, duration, organization, and content. Initial feedback showed agreement on the program’s duration but mixed opinions on the number and length of sessions due to concerns about participant workload and fatigue. Adjustments led to a strong consensus and positive feedback on the program’s coverage of essential nursing practice environment constructs. The program includes sessions on client, professional, and institutional dynamics, focusing on key attributes and outcomes for fostering positive nursing environments. By equipping nurses with knowledge and skills, the program aims to enhance work environments effectively. These findings provide a substantial advancement in the field, offering a robust framework for future initiatives. Full article

The growing population of aging adults, coupled with the widespread adoption of technology, including within virtual environments, prompts the need to understand technology engagement preferences among older adults. This study aimed to explore the experiences and perceptions of older adults engaging with a client-centered immersive virtual reality (IVR) protocol tailored to their specific occupational interests. Employing a mixed methods approach, the research combined the quantitative System Usability Scale (SUS) assessment with qualitative interviews to examine the feasibility, usability, and learning experiences of community-dwelling older adults. Fifteen (n = 15) older adult participants trialed an IVR session tailored to match their chosen occupations of importance. Findings revealed that the usability of IVR varied significantly among participants, with an average SUS score of 55, indicating a need for further investigation into usability issues. Qualitative analysis identified three themes: IVR is usable when it is intuitive and with training, balance the apps for success, and overall lasting impressions were related to the perceived implementation for the participant. The incorporation of meaningful occupations in IVR programming is feasible and can be integrated into healthy aging-in-place programming; however, expanding available leisure-based apps and increasing the learning time before engagement should be considered. Full article

Equine-assisted intervention (EAI) studies deal with clients, whereas very few studies focused on the effects on animals. EAI equids are also submitted to management, which influences their welfare. Management and working conditions depend on human decisions and perception. We gathered information through a survey about facilities managers’ strategies (n = 51) and obtained direct information on management and working practices and their consequences on equids’ welfare through an observational study (n = eight facilities, 174 equids). Differences in managers’ perceptions of good management practices were related to the facility’s involvement in EAI, e.g., increased awareness of equids’ needs (housing and feeding), especially when EAI was the main activity. A detailed observational study on eight additional facilities confirmed that. Facility management profiles were paralleled by equids’ welfare profiles. Clear correlates were found between management decisions and welfare consequences. One major factor influencing welfare and human–equid interactions appeared to be working modalities, with more EAI facilities practicing groundwork and bitless work. Facilities where equids were the most involved in mixed activities had the most equids with compromised welfare. Given EAI clients’ particularities, conventional working modalities are less adapted and at risk of increased discomfort for equids. Overall, survey and observational approaches converged but some discrepancies (choice of equid type) appeared between the reported and observed prevalence. Full article

In the field of high-end equipment, the synergistic effect of friction-reducing agents plays an important role in the performance study of gel grease. Exploring its tribological and rheological properties can not only significantly reduce the coefficient of friction of mechanical components and enhance its viscosity at high temperatures but also effectively reduce energy consumption, thus improving the service life of high-end equipment. In this study, Schaeffler Load 460 gel grease was mixed with polysiloxane viscosity modifier (PV611) and molybdenum dialkyl dithiocarbamate (RFM3000) according to (3:1, 1:1, and 1:3), and its tribological properties and rheological properties were investigated by the MRS-10G friction and wear tester, MCR302 rotational rheometer, and crossover test. Comparative analyses of tribological and rheological properties were carried out. The results showed that the average coefficient of friction of Schaeffler Load 460 grease was reduced by 57.2%, 60%, and 71.9%, respectively, with the addition of two different ratios of friction reducers; the average diameter of abrasive spots was reduced by 44.5%, 55.4%, and 61.3%; and the shear stress and viscosity were increased by 117.94 Pa and 1295.02 mPa∙s, respectively, compared with that of the original grease, which is a good example for the lubrication of gel grease in the high-end equipment industry. This study provides a new direction and idea for the lubrication research of gel grease in the high-end equipment industry. Full article

No Money No Time (NMNT) is a culinary nutrition website designed to optimize diet quality. The primary aim was to evaluate the impact of an online targeted nutrition challenge email campaign that encouraged engagement with NMNT and goal setting to improve diet quality and weekly food expenditure. A secondary aim was to assess NMNT engagement. Australian adults ≥18 years were recruited to the eHealth nutrition challenge delivered via weekly emails. Diet quality was assessed using the Healthy Eating Quiz (HEQ) diet quality tool. Engagement was assessed using email open and click-through rates. Intention-to-treat (ITT) analysis was conducted using mixed effects linear regression. Of 481 adults (49.7 ± 13.9 years, 84% female) who enrolled 79 (16%) completed the challenge. ITT results indicated statistically significant 6-week increases in diet quality score (+3.8 points p ≤ 0.001, d = 0.58) with sub-scale improvements in vegetables (+0.9 points, p = 0.01, d = 0.32), fruit (+1.2 points, p ≤ 0.001, d = 0.55), and dairy (+0.9 points, p ≤ 0.001, d = 0.58). There were significant post-challenge reductions in household spending on takeaway/snacks/coffee of AUD 8.9 per week (p = 0.01, d = 0.29), body weight reduction (−0.6 kg, p = 0.03, d = 0.26), and BMI (−0.2 kg/m²p = 0.02, d = 0.28). The email open rate remained constant at around 67% (56% to 75%), with an average click-through rate of 18% (7.1% to 37.9%). The eHealth nutrition challenge significantly improved diet quality while reducing BMI and money spent on discretionary foods. Strategies to scale the challenge should be tested as an innovative population strategy for improving diet quality, health indicators, and managing household food budgets. Full article

Relatively little attention has been given to mixed anxiety and depression in autistic youth, particularly how this differs between males and females. This study investigated sex-based differences in the prevalence and correlates of mixed anxiety and depression in a sample of 51 autistic males (M age = 10.16 yr, SD = 2.81 yr, and range = 6 yr to 17 yr) and 51 autistic females (M age = − 10.07 yr, SD = 2.76 yr, and range = 6 yr to 17 yr), matched for age, IQ, and autism severity. Self-reports on generalised anxiety disorder and major depressive disorder, morning salivary cortisol, ADOS-2 scores, and WASI-II full-scale scores were collected from these autistic youth, and data on the ASD-related symptoms of these youth were collected from their parents. The data were analysed for total anxiety–depression score levels, for the underlying components of this scale, and for the individual items used in the scale. The results indicate no significant sex differences for the prevalence of mixed anxiety and depression total scores or the underlying components of anxiety and depression or for the individual items of the mixed anxiety–depression scale. There were sex differences in the significant correlates of mixed anxiety and depression: morning cortisol and ASD-related difficulties in social interaction for females, and ASD-related behaviour for males. Males’ feelings of being restless or edgy were correlated with their social interaction and repetitive and restricted behaviour. Females’ difficulties in social interaction were correlated with their concerns about their abilities and their sleeping problems. Females’ sleeping problems, their tendency to talk about dying, and feeling worthless, were correlated with their morning cortisol. These findings suggest that, while mixed anxiety and depression is experienced similarly by autistic males and females at the global, component, and individual item levels, specific aspects of the symptomatology of mixed anxiety and depression are differently associated with aspects of their ASD-related symptomatology and their levels of chronic physiological stress for males and females. Full article

The chordal ring (CR) graphs are a well-known family of graphs used to model some interconnection networks for computer systems in which all nodes are in a cycle. Generalizing the CR graphs, in this paper, we introduce the families of chordal multi-ring (CMR), chordal ring mixed (CRM), and chordal multi-ring mixed (CMRM) graphs. In the case of mixed graphs, we can have edges (without direction) and arcs (with direction). The chordal ring and chordal ring mixed graphs are bipartite and 3-regular. They consist of a number r (for $r\ge 1$) of (undirected or directed) cycles with some edges (the chords) joining them. In particular, for CMR, when $r=1$, that is, with only one undirected cycle, we obtain the known families of chordal ring graphs. Here, we used plane tessellations to represent our chordal multi-ring graphs. This allowed us to obtain their maximum number of vertices for every given diameter. Additionally, we computationally obtained their minimum diameter for any value of the number of vertices. Moreover, when seen as a lift graph (also called voltage graph) of a base graph on Abelian groups, we obtained closed formulas for the spectrum, that is, the eigenvalue multi-set of its adjacency matrix. Full article

As electronic sensors and sensor networks advance, perception data are increasingly characterized by mixed attributes. Traditional anomaly detection methods predominantly focus on numerical attributes. In this paper, we introduce a weighted neighborhood information network (WNIN)-enabled anomaly detection method tailored for mixed-attribute data from electronic sensors and sensor networks. Firstly, we employ the analytic hierarchy process (AHP) to analyze the security of sensor networks, leveraging a hierarchical electronic sensor network model to construct a hierarchical perception security architecture for anomaly detection. Subsequently, a neighborhood information system is established to ascertain the relationships between data objects with mixed attributes. We then develop the WNIN to encapsulate the relationships, and a state-transferring probability matrix based on data object similarity is derived. Ultimately, a random wandering process within the WNIN is executed, and the importance of data objects is evaluated using the steady-state distribution vector, thereby determining the anomaly data. Simulation outcomes reveal that our proposed method attains superior anomaly detection rates compared with existing methods. Full article

Rainwater and sewage are important pollution sources for surface water bodies. Vertical greening systems (VGSs) are extensively employed for these wastewater treatments due to the green and sustainable characteristics, as well as their high-efficiency in pollutant (organic matter, nitrogen, and phosphorus) removal. At present, more and more VGSs are designed with green buildings, serving city ecosystems. This study provides an overview of different kinds of VGSs for rain and sewage treatment, emphasizing their types, design, mechanisms, selection of plants, and growth substrate. Plants play a crucial role in pollutant removal, and different plants usually obtain different efficiencies of water treatment. Climbing plants and ornamental plants with fast growth rates are priority selections for VGSs, including Canna lilies, Jasmine, Grape vine, Boston ivy, Pittosporum tobira, Pelargonium australe, Mentha aquatica, and Lythrum salicaria. The substrate is the most critical part of the VGS, which plays an important role in regulating water flow, supporting plant growth, promoting biofilm growth, filtering pollutants, and adsorbing nutrients. The single substrate either has a blockage problem or has a short holding time. Therefore, a number of studies have mixed the substrates and integrated the advantages of the substrates to form a complementary effect, thereby improving the overall purification efficiency and stability. Novel substrates (sand, spent coffee grounds, date seeds, coffee grinds, reed-based, etc.) are usually mixed with coco coir, light-weight expanded clay, growstone, or perlite at a certain ratio to obtain optimum treatment performance. Moreover, plants in clay show more significant growth advantages and health statuses than in zeolite or soil. Operating parameters are also significant influences on the treatment performance. This review provides theoretical and technical support for designing sustainable, environmentally friendly, and cost-effective VGSs in treating rainwater and sewage. Full article