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Transient response of doubly-curved bio-inspired composite shells resting on viscoelastic foundation subject to blast load using improved first-order shear theory and isogeometric approach 被引量:1
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作者 Thuy Tran Thi Thu Tu Nguyen Anh +1 位作者 Hue Nguyen Thi Hong Nguyen Thi 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第8期171-193,共23页
Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties... Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties and environmental resilience. Biological composite structures with helicoidal schemes and designs have remarkable capacities to absorb impact energy and withstand damage. However, there is a dearth of extensive study on the influence of fiber redirection and reorientation inside the matrix of a helicoid structure on its mechanical performance and reactivity. The present study aimed to explore the static and transient responses of a bio-inspired helicoid laminated composite(B-iHLC) shell under the influence of an explosive load using an isomorphic method. The structural integrity of the shell is maintained by a viscoelastic basis known as the Pasternak foundation, which encompasses two coefficients of stiffness and one coefficient of damping. The equilibrium equations governing shell dynamics are obtained by using Hamilton's principle and including the modified first-order shear theory,therefore obviating the need to employ a shear correction factor. The paper's model and approach are validated by doing numerical comparisons with respected publications. The findings of this study may be used in the construction of military and civilian infrastructure in situations when the structure is subjected to severe stresses that might potentially result in catastrophic collapse. The findings of this paper serve as the foundation for several other issues, including geometric optimization and the dynamic response of similar mechanical structures. 展开更多
关键词 Blast load Modified first-order shear theory Biological composite structures
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Efficient slope reliability and sensitivity analysis using quantile-based first-order second-moment method
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作者 Zhiyong Yang Chengchuan Yin +2 位作者 Xueyou Li Shuihua Jiang Dianqing Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期4192-4203,共12页
This paper introduces a novel approach for parameter sensitivity evaluation and efficient slope reliability analysis based on quantile-based first-order second-moment method(QFOSM).The core principles of the QFOSM are... This paper introduces a novel approach for parameter sensitivity evaluation and efficient slope reliability analysis based on quantile-based first-order second-moment method(QFOSM).The core principles of the QFOSM are elucidated geometrically from the perspective of expanding ellipsoids.Based on this geometric interpretation,the QFOSM is further extended to estimate sensitivity indices and assess the significance of various uncertain parameters involved in the slope system.The proposed method has the advantage of computational simplicity,akin to the conventional first-order second-moment method(FOSM),while providing estimation accuracy close to that of the first-order reliability method(FORM).Its performance is demonstrated with a numerical example and three slope examples.The results show that the proposed method can efficiently estimate the slope reliability and simultaneously evaluate the sensitivity of the uncertain parameters.The proposed method does not involve complex optimization or iteration required by the FORM.It can provide a valuable complement to the existing approximate reliability analysis methods,offering rapid sensitivity evaluation and slope reliability analysis. 展开更多
关键词 Slope reliability Sensitivity analysis QUANTILE first-order second-moment method(FOSM) first-order reliability method(FORM)
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Psychosocial and Socioeconomic Barriers to Treatment Adherence in Pediatric Atopic Dermatitis
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作者 Kelly Frasier Darianne Zimmer +7 位作者 Grace Herrick Marissa Ruppe Mahnoor Mukarram Bret-Ashleigh Coleman Madeline Coleman Therese Anne Limbana Brooke Blan Evadne Rodriguez 《Open Journal of Medical Psychology》 2024年第4期87-102,共16页
Research Background: Atopic dermatitis (AD) is a chronic inflammatory skin condition in children that significantly impacts physical health and quality of life. Adherence to treatment regimens is crucial for effective... Research Background: Atopic dermatitis (AD) is a chronic inflammatory skin condition in children that significantly impacts physical health and quality of life. Adherence to treatment regimens is crucial for effective disease management but is often hindered by various psychosocial and socioeconomic barriers. Parental mental health issues, family dynamics, financial constraints, and limited access to specialized care contribute to inconsistent treatment adherence, exacerbating the condition. Purpose/Aim: The aim of this study is to explore the multifaceted barriers to treatment adherence in children with AD and evaluate the effectiveness of current interventions targeting these challenges. The study seeks to identify strategies that can improve adherence and health outcomes by addressing psychosocial and socioeconomic factors. Method: The method involves a comprehensive review of existing literature on the impact of psychosocial and socioeconomic factors on treatment adherence in children with AD. The study also examines various interventions designed to address these barriers, including community support programs, family-centered interventions, financial aid, integrated care models, and telehealth solutions. Results: Results indicate that psychosocial barriers, such as parental anxiety and depression, significantly hinder effective disease management. Family dynamics, including poor communication and single-parent households, complicate adherence efforts. Socioeconomic factors, such as financial constraints and limited healthcare access, further impede adherence. Interventions that address these barriers show promise in improving treatment adherence and health outcomes. Community support programs and family-centered interventions enhance parental mental health and family communication. Financial aid programs and integrated care models help mitigate economic and logistical challenges. Telehealth solutions improve access to specialized care, particularly in underserved areas. Conclusion: The study concludes that a holistic approach integrating medical treatment with psychosocial and socioeconomic support is essential for managing pediatric AD effectively. Policy recommendations include increased funding for community support programs, expanded telehealth services, and the integration of social services with medical care. Addressing these barriers comprehensively can enhance treatment adherence and improve the quality of life for children with AD. Further research should focus on long-term outcomes and diverse populations to refine these interventions and ensure they meet the needs of all affected children. 展开更多
关键词 Pediatric Atopic Dermatitis Treatment Adherence Psychosocial barriers Socioeconomic barriers
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Assessment of public perspectives and barriers towards dengue preventive practices using the Health Belief Model in Puducherry,India:A cross-sectional study
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作者 Dharani Govindasamy Gnanasekaran Vijalakashmi +1 位作者 Balakrishnan Vijayakumar Arya Rahul 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2024年第8期358-368,I0001,共12页
Objective:To assess the perspectives and barriers towards dengue preventive practices among the residents of Puducherry,India.Methods:A cross-sectional survey was conducted in 300 households in Puducherry,using a popu... Objective:To assess the perspectives and barriers towards dengue preventive practices among the residents of Puducherry,India.Methods:A cross-sectional survey was conducted in 300 households in Puducherry,using a population-proportionate(7:3)distribution from urban and rural areas by grid sampling.One adult interview per household was conducted and the participants were selected using a KISH grid.A semi-structured questionnaire based on the Health Belief Model(HBM)with additional questions on knowledge assessment was used.Knowledge was assessed based on the correctness of answers and the HBM scores were calculated on a 5-point Likert scale.Participants were categorized based on the median score under each domain.Logistic regression was used for adjusted analysis and models were built to predict the performances in each domain.Results:Four percent of the participants lacked basic knowledge regarding dengue transmission.While 208(69.3%)participants did not consider themselves at risk of contracting dengue within the next year,majority perceived dengue as a disease with low severity.Around 49.3%(148)were skeptical about the benefit of time and money spent on dengue prevention.Inadequate government efforts were stated as the major barrier(47.0%)and frequent reminders(142,47.3%)as the major cue to action.Age above 50 years(aOR 1.78,95%CI 1.04-3.06,P=0.037)and rural locality(aOR 2.68,95%CI 1.52-4.71,P=0.001)were found to be significantly associated with poor knowledge scores.Urban participants had a significantly higher chance to perceive low susceptibility as compared to the rural counterparts(aOR 1.74,95%CI 1.05-2.9,P=0.03).Participants with less than a high school education had low perceived benefits(aOR 2.46,95%CI 1.52-3.96,P<0.001)and low self-efficacy scores(aOR 2.66,95%CI 1.61-4.39,P<0.001).Conclusions:This study identifies key gaps in dengue prevention,including low perceived susceptibility,mild disease perception,limited knowledge of breeding sites,and overreliance on government efforts.Tailoring interventions to community needs,stratified to factors influencing the community perspectives can significantly improve dengue prevention efforts. 展开更多
关键词 DENGUE Public perspectives Prevention barriers Health belief model
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Does the Hartman effect exist in triangular barriers
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作者 李青玲 郑爽 肖智 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期214-230,共17页
We study the phase,Larmor and dwell times of a particle scattered off triangular barriers(TBs).It is interesting that the dependences of dwell,reflective phase and Larmor times on the wave number,barrier width and hei... We study the phase,Larmor and dwell times of a particle scattered off triangular barriers(TBs).It is interesting that the dependences of dwell,reflective phase and Larmor times on the wave number,barrier width and height for a pair of mirror-symmetric(MS)exact triangular barriers(ETBs)are quite different,as the two ETBs have quite distinct scattering surfaces.In comparison,the dependence of the transmitted phase or Larmor times is exactly the same,since the transmitted amplitudes are the same for a pair of MS TBs.We further study the Hartman effect by defining the phase and Larmor velocities associated with the phase and Larmor times.We find no barrier width saturation effect for the transmitted and reflected times.This is indicated by the fact that all the velocities approach finite constants that are much smaller than the speed of light in vacuum for TBs with positive-slope impact faces.As for ETBs with vertical left edges,the naive velocities seem to also indicate the absence of the Hartman effect.These are quite distinct from rectangular barriers and may shed new light on the clarification of the tunneling time issues. 展开更多
关键词 triangular barrier Hartman effect
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A Qualitative Look at Decreasing Barriers to Receiving Uninterrupted Care for People Living with HIV in Rural Southern Georgia
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作者 Joshua M. Kies 《Open Journal of Nursing》 2024年第8期447-458,共12页
Early linkage to antiretroviral therapy (ART) after HIV diagnosis extends life. Low socioeconomic populations with HIV face regional concerns that inhibit early treatment. Barriers include religious-based stigma, lack... Early linkage to antiretroviral therapy (ART) after HIV diagnosis extends life. Low socioeconomic populations with HIV face regional concerns that inhibit early treatment. Barriers include religious-based stigma, lack of local treatment facilities, fear of discovery and purposeful secrecy fostering increased HIV transmission and decreased ART adherence. This ethnographic qualitative study employed semi-structured interviews with 10 health care providers (HCP) and 10 people living with HIV (PLWH) to discover methods to streamline care and increase medication adherence. Clients perceive enhanced care when they are active participants in treatment. HCPs reported positive health outcomes when there was active multidisciplinary communication. Obstacles included a lack of consistent medication assistance programs, homelessness, and limited access to specialized services. There is a need for further investigation on how to provide individualized, holistic treatment to a population of patients with extremely limited federal funding in a geographic region where religious stigma surrounding HIV is widespread. 展开更多
关键词 Antiretroviral Treatment (ART) barriers COMPLIANCE HIV RURAL
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Euler’s First-Order Explicit Method–Peridynamic Differential Operator for Solving Population Balance Equations of the Crystallization Process
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作者 Chunlei Ruan Cengceng Dong +2 位作者 Kunfeng Liang Zhijun Liu Xinru Bao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期3033-3049,共17页
Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridyna... Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridynamic differential operator(EE–PDDO)was obtained for solving the one-dimensional population balance equation in crystallization.Four different conditions during crystallization were studied:size-independent growth,sizedependent growth in a batch process,nucleation and size-independent growth,and nucleation and size-dependent growth in a continuous process.The high accuracy of the EE–PDDO method was confirmed by comparing it with the numerical results obtained using the second-order upwind and HR-van methods.The method is characterized by non-oscillation and high accuracy,especially in the discontinuous and sharp crystal size distribution.The stability of the EE–PDDO method,choice of weight function in the PDDO method,and optimal time step are also discussed. 展开更多
关键词 Population balance equation CRYSTALLIZATION peridynamic differential operator Euler’s first-order explicit method
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Barriers and Motivators of Young Dutch Elite Athletes for Optimizing Their Nutritional Intake
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作者 Marijn de Wit Anja van Geel 《Open Journal of Preventive Medicine》 2024年第7期143-162,共20页
Many young elite athletes do not meet their daily energy and nutrient requirements. However, little research has been done on why these athletes do not meet their daily needs. The aim was to research the barriers and ... Many young elite athletes do not meet their daily energy and nutrient requirements. However, little research has been done on why these athletes do not meet their daily needs. The aim was to research the barriers and motivators of young Dutch elite athletes to optimize their nutritional intake. Quantitative and qualitative research was conducted among 8 handball and 4 volleyball players at the Dutch National Sports Center (17.2 ± 0.8 years). First, the nutritional intake was tracked through food diaries and analyzed in Nutritics. Thereupon, five semi-structured interviews based on the COM-B model were carried out. The interviews were transcribed and coded. The athletes had a reduced intake of energy, carbohydrates, vitamins A, C, E, D, calcium, potassium, zinc, and iron compared to their requirements. Seven themes for optimizing their nutritional intake emerged in the interviews: needs assessment, practical translation, portion size, lack of time, involvement, individuality, and food distribution. Barriers that the athletes experienced were that they did not know what their total daily nutritional needs were and how this translates into practice. In addition, the portion size at dinner was too small. They also had little time to eat a full meal due to time pressure from training and school. On the other hand, motivators were receiving meal options to translate their needs into practice with a distribution of moments when they need to eat. Covering these topics in nutritional workshops where athletes actively participate with more individual focus, could contribute to the optimization of their nutritional intake. 展开更多
关键词 barriers MOTIVATORS Young Elite Athletes Optimize Nutritional Intake
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Assessing Barriers to Mental Healthcare Interventions for Deaf People in Ghana
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作者 Wisdom Kwadwo Mprah Juventus Duorinaah +1 位作者 Lyla Adwan-Kamara Rebecca Tawiah 《Journal of Biosciences and Medicines》 2024年第1期29-51,共23页
While mental health issues are increasingly gaining attention in Ghana, little is known about the situation among deaf people. This study assessed the mental health care needs of deaf people in Ghana. A descriptive de... While mental health issues are increasingly gaining attention in Ghana, little is known about the situation among deaf people. This study assessed the mental health care needs of deaf people in Ghana. A descriptive design, consisting of interviews and focus group discussions, was used to collect data from 97 participants. Findings indicated that participants had limited knowledge on mental health issues. Mental health stigma, inaccessible mental health information and exclusion from mental health programmes were the major barriers hindering access to mental health care services. This study bridges the knowledge gap and provides evidence for the implementation of deaf-friendly services. 展开更多
关键词 ACCESS barriers Deaf People Mental Health CAREGIVERS Civil Society Organizations
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The use of oral human immunodeficiency virus pre-exposure prophylaxis in pregnant and lactating women in sub-Saharan Africa:considerations,barriers,and recommendations
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作者 Enos Moyo Grant Murewanhema +2 位作者 Perseverance Moyo Tafadzwa Dzinamarira Andrew Ross 《Global Health Journal》 2024年第2期41-45,共5页
In sub-Saharan Africa(SSA),63%of new human immunodeficiency virus(HIV)infections in 2021 were among women,particularly adolescent girls,and young women.There is a high incidence of HIV among pregnant and lactating wom... In sub-Saharan Africa(SSA),63%of new human immunodeficiency virus(HIV)infections in 2021 were among women,particularly adolescent girls,and young women.There is a high incidence of HIV among pregnant and lactating women(PLW)in SSA.It is estimated that the risk of HIV-acquisition during pregnancy and the postpartum period more than doubles.In this article,we discuss the safety and effectiveness of drugs used for oral HIV pre-exposure prophylaxis(PrEP),considerations for initiating PrEP in PLW,the barriers to initiating and adhering to PrEP among them and suggest recommendations to address these barriers.Tenofovir/emtricitabine,the most widely used combination in SSA,is safe,clinically effective,and cost-effective among PLW.Any PLW who requests PrEP and has no medical contraindications should receive it.PrEP users who are pregnant or lactating may experience barriers to starting and adhering for a variety of reasons,including personal,pill-related,and healthcare facility-related issues.To address the barriers,we recommend an increased provision of information on PrEP to the women and the communities,increasing and/or facilitating access to PrEP among the PLW,and developing strategies to increase adherence. 展开更多
关键词 Pre-exposure prophylaxis PREGNANCY LACTATION SAFETY barriers RECOMMENDATIONS
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Recent advances in zwitterionic nanoscale drug delivery systems to overcome biological barriers
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作者 Xumei Ouyang Yu Liu +2 位作者 Ke Zheng Zhiqing Pang Shaojun Peng 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2024年第1期49-68,共20页
Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinic... Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinical use up to now,biological barriers between the administration site and the target site hinder the wider clinical adoption of nDDS in disease treatment.Polyethylene glycol(PEG)-modification(or PEGylation)has been regarded as the gold standard for stabilising nDDS in complex biological environment.However,the accelerated blood clearance(ABC)of PEGylated nDDS after repeated injections becomes great challenges for their clinical applications.Zwitterionic polymer,a novel family of antifouling materials,have evolved as an alternative to PEG due to their super-hydrophilicity and biocompatibility.Zwitterionic nDDS could avoid the generation of ABC phenomenon and exhibit longer blood circulation time than the PEGylated analogues.More impressively,zwitterionic nDDS have recently been shown to overcome multiple biological barriers such as nonspecific organ distribution,pressure gradients,impermeable cell membranes and lysosomal degradation without the need of any complex chemical modifications.The realization of overcoming multiple biological barriers by zwitterionic nDDS may simplify the current overly complex design of nDDS,which could facilitate their better clinical translation.Herein,we summarise the recent progress of zwitterionic nDDS at overcoming various biological barriers and analyse their underlyingmechanisms.Finally,prospects and challenges are introduced to guide the rational design of zwitterionic nDDS for disease treatment. 展开更多
关键词 Zwitterionic polymer Nano drug delivery system Biological barrier Targeting delivery Disease treatment
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Assessment of Barriers and Challenges to the Screening and Linkages of Non-Communicable Diseases by Community Health Volunteers in Nyeri County, Kenya
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作者 Kenneth Mugambi Jackline Nyaberi Elizabeth Echoka 《Open Journal of Preventive Medicine》 2024年第5期90-109,共20页
Non-communicable diseases (NCDs) are a significant global health challenge, contributing to 50% of worldwide morbidity and 63% of mortality. The burden is particularly substantial in low—and middle-income countries (... Non-communicable diseases (NCDs) are a significant global health challenge, contributing to 50% of worldwide morbidity and 63% of mortality. The burden is particularly substantial in low—and middle-income countries (LMICs), where 80% of NCD-related deaths occur. A quasi-experimental study addressed this challenge from May 2022 to March 2023. This study utilized a non-equivalent pre-and post-test design, with 300 participants in the quantitative and 70 in the qualitative. The study employed multistage cluster and random sampling to select ten community units, resulting in 150 community health volunteers (CHVs) in the control unit and 150 in the intervention group. Data collection was facilitated through the KOBO app. Qualitative data analysis involved six homogeneous focus group discussions (FGDs) and ten key informant interviews (KIIs), audio-recorded, transcribed, and analyzed using N-Vivo 12. Despite efforts to implement screening programs and improve linkages to care, significant barriers persist. This article reviews these barriers, drawing on current literature and empirical evidence. Key obstacles identified include limited awareness, inadequate healthcare infrastructure, cultural beliefs, financial constraints, fragmented healthcare systems, and challenges linking individuals to appropriate care services. The article explores strategies to overcome these barriers, emphasizing the importance of collaborative approaches involving stakeholders at various levels. Addressing these challenges aims to strengthen NCD screening and linkages to care, ultimately improving health outcomes for populations globally. Several recommendations emerge from the study’s findings and literature review. Raising awareness about NCDs and preventive measures is crucial and can be achieved through targeted health education campaigns and community outreach programs. Addressing healthcare infrastructure deficiencies, such as inadequate facilities and workforce shortages, is essential to ensure access to quality care. Cultural beliefs and practices also play a significant role in shaping health-seeking behavior. Engaging with local communities and incorporating cultural sensitivity into healthcare delivery can help bridge the gap between traditional beliefs and modern healthcare practices. Financial constraints pose a significant barrier to healthcare services, particularly in LMICs. Innovative financing mechanisms, such as health insurance schemes or subsidies, can help alleviate this burden and improve access to care. Furthermore, the fragmented nature of healthcare systems can hinder effective NCD management. Enhancing coordination and integration between primary care providers, specialists, and community health workers is essential to ensure seamless care delivery and patient follow-up. Finally, strengthening linkages between screening programs and care services is critical for the timely diagnosis and management of NCDs. This requires establishing robust referral systems and ensuring continuity of care for patients throughout their healthcare journey. In conclusion, addressing the multifaceted barriers to NCD screening and care linkage is essential for improving health outcomes globally. By implementing targeted interventions and fostering collaboration among stakeholders, progress can be made towards reducing the burden of NCDs and promoting population health. 展开更多
关键词 Non-Communicable Diseases barriers CHALLENGES Healthcare Infrastructure AWARENESS Cultural Beliefs Financial Constraints
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Estimation of Landfill Gas and Its Renewable Energy Potential from the Polesgo Controlled Landfill Using First-Order Decay (FOD) Models
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作者 Haro Kayaba Ouarma Issoufou +4 位作者 Dabilgou Téré Compaore Abdoulaye Sanogo Oumar Bere Antoine Koulidiati Jean 《Journal of Environmental Protection》 2024年第10期975-993,共19页
Methane generation in landfills and its inadequate management represent the major avoidable source of anthropogenic methane today. This paper models methane production and the potential resources expected (electrical ... Methane generation in landfills and its inadequate management represent the major avoidable source of anthropogenic methane today. This paper models methane production and the potential resources expected (electrical energy production and potential carbon credits from avoided CH4 emissions) from its proper management in a municipal solid waste landfill located in Ouagadougou, Burkina Faso. The modeling was carried out using two first-order decay (FOD) models (LandGEM V3.02 and SWANA) using parameters evaluated on the basis of the characteristics of the waste admitted to the landfill and weather data for the site. At the same time, production data have been collected since 2016 in order to compare them with the model results. The results obtained from these models were compared to experimental one. For the simulation of methane production, the SWANA model showed better consistency with experimental data, with a coefficient of determination (R²) of 0.59 compared with the LandGEM model, which obtained a coefficient of 0.006. Thus, despite the low correlation values linked to the poor consistency of experimental data, the SWANA model models methane production much better than the LandGEM model. Thus, despite the low correlation values linked to the poor consistency of the experimental data, the SWANA model models methane production much better than the LandGEM V3.02 model. It was noted that the poor consistency of the experimental data justifies these low coefficients, and that they can be improved in the future thanks to ongoing in situ measurements. According to the SWANA model prediction, in 27 years of operation a biogas plant with 33% electrical efficiency using biogas from the Polesgo landfill would avoid 1,340 GgCO2e. Also, the evaluation of revenues due to electricity and carbon credit gave a total revenue derived from methane production of US$27.38 million at a cost of US$10.5/tonne CO2e. 展开更多
关键词 first-order Decay METHANE Modeling LANDFILL Renewable Energy
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Train-induced aerodynamic characteristics of vertical sound barriers influenced by several factors
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作者 Xiaowei Qiu Xiaozhen Li +1 位作者 Jing Zheng Ming Wang 《Railway Engineering Science》 EI 2024年第2期177-193,共17页
Investigations into the aerodynamic properties of vertical sound barriers exposed to high-speed operations employ computational fluid dynamics.The primary focus of this research is to evaluate the influence of train s... Investigations into the aerodynamic properties of vertical sound barriers exposed to high-speed operations employ computational fluid dynamics.The primary focus of this research is to evaluate the influence of train speed and the distance(D)from the track centerline under various operating conditions.The findings elucidate a marked elevation in the aerodynamic effect amplitude on sound barriers as train speeds increase.In single-train passages,the aerodynamic effect amplitude manifests a direct relationship with the square of the train speed.When two trains pass each other,the aerodynamic amplitude intensifies due to an additional aerodynamic increment on the sound barrier.This increment exhibits an approximate quadratic correlation with the retrograde train speed.Notably,the impact of high-speed trains on sound barrier aerodynamics surpasses that of low-speed trains,and this discrepancy amplifies with larger speed differentials between trains.Moreover,the train-induced aerodynamic effect diminishes significantly with greater distance(D),with occurrences of pressure coefficient(CP)exceeding the standard thresholds during dual-train passages.This study culminates in the formulation of universal equations for quantifying the influence of train speed and distance(D)on sound barrier aerodynamic characteristics across various operational scenarios. 展开更多
关键词 Aerodynamic characteristic Sound barrier Two trains passing each other Distance from track centerline CFD simulation
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Utilizing sediment grain size characteristics to assess the effectiveness of clay–sand barriers in reducing aeolian erosion in Minqin desert area,China
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作者 SONG Dacheng ZHAO Wenzhi +5 位作者 LI Guangyu WEI Lemin WANG Lide YANG Jingyi WU Hao MA Quanlin 《Journal of Arid Land》 SCIE CSCD 2024年第5期668-684,共17页
The clay–sand barriers in Minqin desert area,China,represent a pioneering windbreak and sand fixation project with a venerable history of 60 a.However,studies on evaluating the long-term effectiveness of clay–sand b... The clay–sand barriers in Minqin desert area,China,represent a pioneering windbreak and sand fixation project with a venerable history of 60 a.However,studies on evaluating the long-term effectiveness of clay–sand barriers against aeolian erosion,particularly from the perspective of surface sediment grain size,are limited and thus insufficient to ascertain the protective impact of these barriers on regional aeolian activities.This study focused on the surface sediments(topsoil of 0–3 cm depth)of clay–sand barriers in Minqin desert area to explain their erosion resistance from the perspective of surface sediment grain size.In March 2023,six clay–sand barrier sampling plots with clay–sand barriers of different deployment durations(1,5,10,20,40,and 60 a)were selected as experimental plots,and one control sampling plot was set in an adjacent mobile sandy area without sand barriers.Surface sediment samples were collected from the topsoil of each sampling plot in the study area in April 2023 and sediment grain size characteristics were analyzed.Results indicated a predominance of fine and medium sands in the surface sediments of the study area.The deployment of clay–sand barriers cultivated a fine quality in grain size composition of the regional surface sediments,increasing the average contents of very fine sand,silt,and clay by 30.82%,417.38%,and 381.52%,respectively.This trend became markedly pronounced a decade after the deployment of clay–sand barriers.The effectiveness of clay–sand barriers in erosion resistance was manifested through reduced wind velocity,the interception of sand flow,and the promotion of fine surface sediment particles.Coarser particles such as medium,coarse,and very coarse sands predominantly accumulated on the external side of the barriers,while finer particles such as fine and very fine sands concentrated in the upwind(northwest)region of the barriers.By contrast,the contents of finest particles such as silt and clay were higher in the downwind(southeast)region of the sampling plots.For the study area,the deployment of clay–sand barriers remains one of the most cost-effective engineering solutions for aeolian erosion control,with sediment grain size parameters serving as quantitative indicators for the assessment of these barriers in combating desertification.The results of this study provide a theoretical foundation for the construction of windbreak and sand fixation systems and the optimization of artificial sand control projects in arid desert areas. 展开更多
关键词 clay-sand barriers sediment grain size grain size distribution aeolian erosion windbreak and sand fixation Minqin desert area
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Public knowledge about and attitudes toward organ donation, and public barriers to donate in Jordan: A cross-sectional study
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作者 Adham Al-Salhi Elham H Othman 《World Journal of Transplantation》 2024年第4期110-122,共13页
BACKGROUND Organ donation is a critical issue that is receiving greater attention worldwide.In Jordan,the public’s knowledge about and attitudes toward organ donation play a significant role in the availability of or... BACKGROUND Organ donation is a critical issue that is receiving greater attention worldwide.In Jordan,the public’s knowledge about and attitudes toward organ donation play a significant role in the availability of organs for transplantation.AIM To assess the public knowledge about and attitudes toward organ donation in Jordan.METHODS A cross-sectional design was used to collect data from 396 Jordanian citizens via an online self-reported questionnaire.RESULTS Overall,396 participants were recruited.Of the entire sample,93.9%of the participants had heard about and had sufficient knowledge about organ donation but they had limited knowledge about brain death.The most common source of information about organ donation was social media networks.Females were found to score significantly higher than males for attitude.Those who had thought about organ donation or registered their names to donate scored signi-ficantly higher in terms of attitudes to donation than their counterparts who had not.The most common reasons for limited organ donation practices in Jordan were a lack of awareness programs and insufficient knowledge in society.CONCLUSION Greater public understanding of organ donation appears to be associated with more positive attitudes toward organ donation.Most participants responded positively regarding their attitude toward organ donation as they believed that this action could give another person a chance to live.Moreover,most agreed that they would donate their organs after their death.Otherwise,the participants had limited general knowledge about brain death,and most had not registered their names to donate their organs.These findings indicate the need for public awareness campaigns and educational programs to encourage more people to become organ donors. 展开更多
关键词 ATTITUDE barriers JORDAN KNOWLEDGE Organ donation PUBLIC
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Impact Containment Barriers with Geotextile Tubes
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作者 Flávio da Silva Ornelas Luís Fernando Martins Ribeiro Rafael Cerqueira Silva 《Journal of Geoscience and Environment Protection》 2024年第5期325-344,共20页
Recently, tragic tailings dam collapses in Brazil have caused deaths and major destruction and the need to develop technologies capable of preventing damage to people and the environment. Brazilian tailings dams are i... Recently, tragic tailings dam collapses in Brazil have caused deaths and major destruction and the need to develop technologies capable of preventing damage to people and the environment. Brazilian tailings dams are in a situation of uncertainty due to new legislation that even requires decommissioning, an activity that involves many problems and where the risk of failure is the main one. An impact containment structure downstream of these dams can be effective and geotextile tubes, in a new approach, have emerged as an option with advantages in terms of execution, costs and safety. The technology is versatile and can bring many benefits such as the reuse of tailings or filling with low-energy or reused materials. In this research, geotextile tubes were tested as free containment barriers, experiencing impacts in reduced models. The safety factor for the stability of the structure was constructed using an equation which is the ratio between the self-weight of the barrier structure and its coefficient of static friction and the impact pressure, where the data showed an adequate correlation which suggests the viability of mitigating risks. 展开更多
关键词 Geotextile Tube Debris Flow barriers IMPACT MINING
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Analysis of current status of and barriers to exercise participation among patients on maintenance hemodialysis
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作者 Xin TIAN Xiuli LI Jianhua DENG 《Journal of Integrative Nursing》 2024年第2期96-102,共7页
Objective:The objective of this study was to analyze the current status of barriers to exercise participation(EP)among patients on maintenance hemodialysis(MHD).Materials and Methods:A cross-sectional study was conduc... Objective:The objective of this study was to analyze the current status of barriers to exercise participation(EP)among patients on maintenance hemodialysis(MHD).Materials and Methods:A cross-sectional study was conducted on 277 outpatients undergoing MHD in 2 tertiary first-class hospitals in Beijing from February 2023 to June 2023 who were selected using convenience sampling method.The data of patients on MHD were collected using the general information questionnaire,Physical Activity Rating Scale,Exercise Benefits/Barriers Scale(EBBS),and Exercise Self-Efficacy Scale(ESES).The relationship between EP and barriers to EP was analyzed through univariate and multivariate linear regression models.Results:Patients on MHD had a low exercise volume score of 13.71±0.68 points and a medium EBBS score of 63.36±0.40 points.Multivariate logistic analysis showed that exercise volume was significantly related to the following four aspects,including low monthly household income per capita(odds ratio[OR]=86.741,95%confidence interval[CI][1.164-6.465],P=0.042),primary underlying disease of diabetic nephropathy(OR=45.993,95%CI[1.353-1.564],P=0.033),the belief that“fatigue in lower extremities hinders exercise”(OR=4.697,95%CI[1.127-19.585],P=0.034),and the belief that“physical exercise bringing optimistic and positive life attitude”(OR=0.074,95%CI[0.007-0.830],P=0.035).Conclusions:Since patients on MHD had low physical exercise volume,the health-care provider should pay more attention on the controllable factors that affect the EP of patients on MHD.Therefore,feasible and effective intervention measures can be formulated based on ESES in clinical nursing. 展开更多
关键词 barrier(s) exercise rehabilitation EXERCISE maintenance hemodialysis physical activity renal dialysis
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Effects of surface chlorine atoms on charge distribution and reaction barriers for photocatalytic CO_(2)reduction
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作者 Wendong Zhang Wenjun Ma +6 位作者 Yuerui Ma Peng Chen Qingqing Ye Yi Wang Zhongwei Jiang Yingqing Ou Fan Dong 《Nano Materials Science》 EI CAS CSCD 2024年第2期235-243,共9页
Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are st... Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are still low due to the sluggish dynamics of transfer processes involved in proton-assisted multi-electron reactions.Lowering the formation energy barriers of intermediate products is an effective method to enhance the selectivity and productivity of final products.In this study,we aim to regulate the surface electronic structure of Bi_(2)WO_(6)by doping surface chlorine atoms to achieve effective photocatalytic CO_(2)reduction.Surface Cl atoms can enhance the absorption ability of light,affect its energy band structure and promote charge separation.Combined with DFT calculations,it is revealed that surface Cl atoms can not only change the surface charge distribution which affects the competitive adsorption of H_(2)O and CO_(2),but also lower the formation energy barrier of intermediate products to generate more intermediate*COOH,thus facilitating CO production.Overall,this study demonstrates a promising surface halogenation strategy to enhance the photocatalytic CO_(2)reduction activity of a layered structure Bi-based catalyst. 展开更多
关键词 Surface chlorine atoms Charge distribution Reaction barriers Photocatalytic CO_(2)reduction Bi_(2)WO_(6)
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Analysis of the Impact of Technical Trade Barriers on the Export of Toys-Based on Analysis of Zhejiang,China
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作者 LIU Ningning CHEN Xiaoxi 《Chinese Business Review》 2024年第1期37-46,共10页
Technical barriers to trade,as a non-tariff barrier,have an increasing impact on the international market.As a major province in toy exports,Zhejiang Province’s toy export trade is therefore greatly hindered.This art... Technical barriers to trade,as a non-tariff barrier,have an increasing impact on the international market.As a major province in toy exports,Zhejiang Province’s toy export trade is therefore greatly hindered.This article aims to explore the impact of technical trade barriers on toy exports in Zhejiang Province and analyze countermeasures.Through literature review and some empirical analysis,it is found that technical trade barriers have greatly promoted the development of Zhejiang’s toy industry;however,they have also subjected it to impacts and pressures such as cost and technology.In response to the impact of technical trade barriers on toy exports,this article proposes corresponding countermeasures to avoid such barriers:firstly,establish a quality management system that complies with export product regulations to ensure that the products produced can meet international requirements and standards;secondly,reduce dependence on overseas markets;then enhance one’s own technology,and strengthen product innovation,in order to enhance the international competitiveness of the product and oneself;in addition,we should also explore diversified markets and expand the sales channels and coverage of our products. 展开更多
关键词 technical trade barriers Zhejiang Province export of toys countermeasure analysis
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