Assessment of the Content and Utilization of Antenatal Care Services in a Rural Community in Cameroon: A Cross-Sectional Study

Background: Pregnant women receive antenatal care (ANC) to ensure favorable pregnancy outcomes. Despite the high ANC coverage rate registered nationally in Cameroon;rural women, women with no formal education and those in the most deprived quintile still face difficulties in having access to quality ANC. The impact of the aforementioned factors on ANC use in the Muea Health Area (MHA) is unknown. The objective of this study was to determine the proportion of women attending ANC and the factors influencing ANC attendance in the MHA. Materials and Methods: This was a community based, analytical, cross sectional survey that involved pregnant women and women with children less than two years old who gave an informed consent or assent. Data were collected using a semi structured questionnaire. EPI info Version 7 and Stat Pac for Windows version 12??1998-2011 (Stat Pac Inc, Bloomington, USA) were used for data analysis. Associations were considered statistically significant for p values less than 0.05. Results: Two hundred and twenty women were interviewed. The mean age was 25 years (SD 5.28). Ninety-nine percent of women had at least one ANC visit meanwhile 84.8% had at least four ANC visits. Only 27.2% of women booked for ANC in the first trimester. Rural (Maumu) residence was associated with inappropriate ANC attendance (attending less than four times) (χ2?= 18.5;p = 0.001). Semi urban women (87%;95% C.I. = 85.10% - 89.0%) were more likely to attend four or more sessions than rural (Maumu) women (60.7%;95% C.I. = 44.2% - 77.3%) (p = 0.001). Participant’s educational level was a significant predictor of early booking for ANC (χ2?= 26.8;p = 0.0002). Semi urban wom- en (79.1%;95% C.I. = 76.0% - 82.2%) were significantly more likely to have a vaginal examination done than rural (Maumu) women (42.1%;95% C.I. = 17.5% - 68.2%) (p = 0.0001). Women who met a doctor during ANC (84.0%;95% C.I. = 80.8% - 87.0%) were more likely to have a vaginal examination done than women who only met a nurse or a midwife during ANC (65.0%;95% C.I. = 57.7% - 71.4%) (p = 0.002). One third of women did not have a vaginal examination performed?during ANC. 45.83% and 47.6% neither did a stool test nor received an insecticide treated net (ITN) respectively. Conclusion: Women in the MHA start their antenatal care late, so they should be encouraged to book early for antenatal surveillance. Furthermore, efforts should be made to increase the access of these women to quality ANC services and to adequately trained ANC providers.

Data-Driven Model for Risk Assessment of Cable Fire in Utility Tunnels Using Evidential Reasoning Approach

Cable fire is one of the most important events for operation and maintenance(O&M)safety in underground utility tunnels(UUTs).Since there are limited studies about cable fire risk assessment,a comprehensive assessment model is proposed to evaluate the cable fire risk in different UUT sections and improve O&M efficiency.Considering the uncertainties in the risk assessment,an evidential reasoning(ER)approach is used to combine quantitative sensor data and qualitative expert judgments.Meanwhile,a data transformation technique is contributed to transform continuous data into a five-grade distributed assessment.Then,a case study demonstrates how the model and the ER approach are established.The results show that in Shenzhen,China,the cable fire risk in District 8,B Road is the lowest,while more resources should be paid in District 3,C Road and District 25,C Road,which are selected as comparative roads.Based on the model,a data-driven O&M process is proposed to improve the O&M effectiveness,compared with traditional methods.This study contributes an effective ER-based cable fire evaluation model to improve the O&M efficiency of cable fire in UUTs.

New Model for Environmental Impact Assessment of Tunneling Projects

Designers of infrastructure are aware that the government, owners and users become more and more concerned about negative environmental impacts of tunnels, so environmental assessment of tunnels are becoming an issue in the process of tunnel design. In this study, to assess tunnels in construction and operation phases, the matrix method, through which the “Impacting Factors” and “Environmental Components” are determined, is also outlined. The affected environment was divided into thirteen components, such as Ecology, Surface water, Air quality, etc. In this paper, matrix method was applied to evaluate the impact of tunneling in three typical tunnels and compare them with standard diagrams of Environmental Components that were derived and introduced. These tunnels were: Urban Utility tunnel in Tehran, Eurasia tunnel in Istanbul and Tsuen Wan drainage tunnel in Hong Kong. Based on the acquired results, the present paper finally concluded that among three cases, Tsuen Wan drainage tunnel affects the environment in construction phase more than others, while Eurasia tunnel effects on air quality are more significant in operation phase.

Assessment and exploitation of the waterfront resources in the middle and lower reaches of the Yangtze River

Waterfront resources are important and special kind of natural resources in the marginal area between land and wat er. The Yangtze River, the longest river in China, is not only rich in waterfront resources, but also has favorable development conditions with gr eat potentiality. Aided by large-scale underwater topographic map, the maj or factors of the waterfront resources in the middle and lower reache s of the Yangtze River, such as the stability, the water depth and the natural conditions for port construction, are assessed in this pap er respectively on the basis of the overall investigations. The result s show that: (1) the waterfront resources are abundant in the middle and lower reaches of the Yangtze River, but lack of perfectly combined high grade waterfront; (2) there exists an obvious regional difference in the natural quality of the waterfront along the Yangtze; (3) the fore-bank water depth and waterfront stability are the main natural fa ctors related to the waterfront quality in the middle and lower reach es of the Yangtze River; (4) the waterfronts along the Yangtze are mainl y used for port, warehouse and industrial purposes; and (5) the waterfronts near important cities are highly used, especially the high-quality waterfronts. In addition, some suggestions for the development and utilization of the waterfron t resources are presented in this paper.

Rangeland Condition and Herbage Utilization by Herbivores of the Kafue Flats North Bank: A Historical Perspective before the Construction of the Itezhi-Tezhi Dam, Zambia

This study was carried out in Blue Lagoon National Park and the North Bank portion of the Kafue Flats Game Management Area along the Kafue River in Zambia. The aim of the study was to determine rangeland condition and utilization by wildlife as well as livestock grazing in Kafue Flats, to establish the baseline data for monitoring after the construction of the Itezhi-Tezhi dam.? Line intercept method and enclosure plots were used to sample in all recognized vegetation types and basal cover and frequency measurements were taken using line intercept method while enclosure plots were used to determine rangeland utilization. Data obtained from records showed that the area had annual mean rainfall of 535 mm at Itezhi-Tezhi, but the lowest rainfall recorded was 214 mm in the 1978-1979 rainy season and the highest was 1, 184 mm in the 1975-1976 season. With regard to range condition, bare ground was highest in the Termitaria vegetation at Nakenda-Critchley (62%), Bowa (57.6%) and Muwezwa (48.45%) while basal cover was relatively high in the flood plain at Namunyona (47.8%). Litter had an almost even distribution in all vegetation types and percent standing crop biomass was relatively high in all sample plots. Rangeland utilization was relatively high around Nakenda-Chitanda (43.54%) in the flood plain and Bowa (31.42%) in the Termitaria vegetation. It was concluded that Termitaria vegetation was largely at high risk of degradation due to overgrazing. While the impact of dams, environmental flows and flood pulse are discussed, detailed research and monitoring should be introduced in addition to the promotion of management of pastures in this rangeland.

Acute aortic dissection:utilizing imaging modalities to improve detection

Acute aortic dissection is a serious condition in elderly patients and may become fatal rapidly if left undiagnosed and untreated. As pointed out by Welch et al1chest radiography is a screening test for this condition by detecting these signs such as widening mediastinum,blurring of the aortic knob, left apical cap, etc.

Lifecycle carbon footprint and cost assessment for coal-to-liquid coupled with carbon capture,storage,and utilization technology in China

Thecoal-to-liquidcoupledwithcarbon capture,utilization,and storage technology has the potential to reduce CO_(2)emissions,but its carbon footprint and cost assessment are still insufficient.In this paper,coal mining to oil production is taken as a life cycle to evaluate the carbon footprint and levelized costs of direct-coal-toliquid and indirect-coal-to-liquid coupled with the carbon capture utilization and storage technology under three scenarios:non capture,process capture,process and public capture throughout the life cycle.The results show that,first,the coupling carbon capture utilization and storage technology can reduce CO_(2)footprint by 28%-57%from 5.91 t CO_(2)/t:oil of direct-coal-to-liquid and 24%-49%from 7.10 t CO_(2)/t:oil of indirect-coal-to-liquid.Next,the levelized cost of direct-coal-to-liquid is 648-1027$/t of oil,whereas that of indirect-coal-to-liquid is 653-1065$/t of oil.When coupled with the carbon capture utilization and storage technology,the levelized cost of direct-coalto-liquid is 285-1364$/t of oil,compared to 1101-9793/t of oil for indirect-coal-to-liquid.Finally,sensitivity analysis shows that CO_(2)transportation distance has the greatest impact on carbon footprint,while coal price and initial investment cost significantly affect the levelized cost ofcoal-to-liquid.

Self-assessed health and its aspects in the case of Mongolia

Self health assessment is a simple indicator that is widely used for measuring an individual’s perception of his or her overall health. Many studies have been conducted by way of showing which particular aspects should be included in health self assessment, especially in developed world. In the developing world, however, very few studies have examined self health assessment. The aim of this study was to identify particular aspects and associations in self health assessment and differences between subgroups in Ulaanbaatar, Mongolia. The area sampling approach and Kish tables were used for selecting respondents. Total 500 respondents were surveyed by paper-based questionnaires. Spearman’s analysis and multiple logistic regression analysis were used to show relations between variables. Sociodemographic status, such as age and gender, proved to be important in self health assessment. Other factors affecting self health assessment included the number of family members, daily life and lifestyles, social environment, community motivation, and utilization of health services. Women, the elderly, or people with less-than- normal access to information suffer from poor self-assessed health. People who are socially inactive and who have poor living conditions are less likely to use health care services and are likely to assess their health as “poor.” In order to reduce the poor self-assessed health status it is important to address disparities in socioeconomic factors, such as age, gender, employment, and residential area. In addition, more attention should be paid to community and health services, as well as to health promotion and empowerment activities, including income-generation activities. Further research is also needed, however, for better understanding of about the local people and their health-related issues.

基于故障树和贝叶斯网络的管廊运维风险评估

城市地下综合管廊在运维过程中事故时有发生,为了量化管廊运维风险并分析关键风险因素,提出一种基于故障树和模糊贝叶斯网络的城市地下综合管廊运维风险评估方法。在综合考虑管廊风险因素的基础上构建故障树模型,将其映射为贝叶斯网络。基于ALARP准则划分风险因素状态等级,根据模糊数和模糊子集计算底事件的发生概率,利用最大似然估计法求解中间事件的条件概率,构建管廊运维风险贝叶斯网络模型,精准评估城市地下综合管廊运维风险。结果表明:所评估的管廊运维过程风险等级为High的概率为28%,接近30%的风险阈值,因此需要及时对管廊风险进行管控。该方法能够科学、合理地评价风险水平并确定关键因素,可为管廊运维安全保障和管理提供参考。

玢岩型铁矿床尾矿中磷、稀土战略性矿产资源调查与综合利用研究:以安徽凹山矿田为例

玢岩型铁矿床是铁矿石的重要来源,其除了赋存巨量铁矿资源外,还以产出大量磷灰石为特征,伴生大量的磷、稀土、钒等资源。20世纪,矿业开发大多只回收主要矿种铁,对伴生资源的评价和综合利用较少。文章以凹山玢岩型铁矿田尾矿库为研究对象,开展伴生资源调查评价和综合利用示范研究。通过系统钻探采样、矿物组合分析、元素赋存状态和综合利用实验等研究,文章揭示出尾矿库中经济矿物为磷灰石,可综合利用资源为磷和稀土,并估算尾矿库中磷储量超过115万t、稀土5万t,社会和经济效益巨大,可作为范例进一步研究并推广应用。

鸽粪农业利用潜力及其重金属风险评价

为了解鸽粪组分及其农业利用过程中重金属的潜在生态风险,本研究采集了广东省肉鸽养殖基地的鸽粪样品,检测分析了鸽粪中Cu、Zn、Cd、Cr、Ni、Pb、Hg、As 8种重金属含量以及全氮、全磷、全钾含量,采用单因子污染指数法与综合污染指数法评价了鸽粪重金属污染程度,同时,根据水稻所需全氮含量分析鸽粪安全农用年限,并通过Hakanson潜在生态污染评价法进行验算。结果表明:对比德国腐熟肥料标准,鸽粪中Cu、Zn含量超标,样品超标率分别为18.18%和36.36%,总超标率为45.45%。单因子污染指数表明鸽粪重金属Zn、Cu、Ni分别有36.36%、18.18%、18.18%的样品处于污染水平,其余重金属含量均在《有机肥料》(NY/T525-2021)的限量范围内。内梅罗综合污染指数表明,处于警示及以上污染水平的点位主要受Cu、Zn污染。在不考虑重金属流失情况下,广东省水稻种植中连续施用鸽粪10 a无重金属污染风险,而在水田旱作系统中,以作物所需全磷量为施肥指标的情况下,鸽粪安全农用年限可达50 a。研究表明,鸽粪农用过程中会使重金属在农田土壤中累积,引起重金属污染,应加强鸽粪无害化处理及安全利用等技术研究。

退役磷酸铁锂电池梯次利用生命周期评价与碳减排情景分析

以磷酸铁锂电池为研究对象,综合考虑梯次利用比例、使用周期及电池容量等因素,设定不同梯次利用场景,采用生命周期评价方法量化退役动力电池在梯次利用及后续报废处置阶段的环境影响,并对不同梯次利用率情景下的碳减排量进行分析.结果表明,与直接再生利用相比,储能、通信基站、低速电源三种梯次利用场景均表现为环境效益.其中,储能场景环境效益最大,其在气候变化、化石能源消耗、人体毒性-非致癌、陆地生态毒性指标等环境影响指标上均表现出相对优势.基于电池退役量和梯次利用去向,进一步计算出2023年全年磷酸铁锂电池梯次利用的碳减排量为1.05×10^(8) kg CO_(2)eq.当梯次利用率保持当前水平或以10%增长时,至2030年其全年碳减排量可达1.55×10^(9)kg CO_(2)eq.和5.98×10^(9)kg CO_(2)eq.,梯次利用具有良好的减污降碳环境表现.

文化遗产影响评估(CHIAs)保护利用协同目标及其嵌入机制

从保护利用协同目标入手,对国外的文化遗产影响评估实践进行剖析,总结了广州市文评实践的主要特点,针对文化遗产影响评估工作面临的3大难点——与保护管理系统结合方式复杂、自我完善程度不足、其他力量支撑与保障不足,提出由文化遗产影响评估先予机制、触发机制与保障机制共同构成的本土化文化遗产影响评估嵌入机制。

CO_(2)转化技术的环境和经济效益评价及未来发展趋势

2022年全球CO_(2)排放量约为360.7亿t,仅2.3亿t CO_(2)被捕获并利用,占比仅为0.64%。为了实现2060年的碳中和目标,CO_(2)排放量需降至50亿t,CO_(2)利用总量需达到12亿t,其利用占比将增至24%,提高CO_(2)利用水平迫在眉睫。碳捕集、利用与封存(CCUS)技术已经成为减少CO_(2)排放、应对全球气候问题最具潜力的技术选择之一,通过不同的技术路径将捕集的CO_(2)转化为具有高附加值的工业产品一直是学术界和工程界的研究重点和热点,但不同的转化技术对于CO_(2)减排的潜在贡献仍存在不确定性。对近年来CO_(2)转化技术的发展现状进行了系统的综述,聚焦于3种具有代表性的CO_(2)转化路径和产品,并结合工业应用案例,对不同技术路径和不同产品的环境影响和技术经济性进行了比较分析。CO_(2)的碳酸化、利用CO_(2)生产聚合物产品等路径具有较高的碳负排放潜力,对于减少总体CO_(2)排放具有重要意义。

厨余垃圾厌氧消化过程的生命周期评价:以湖南省娄底市为例

选取湖南省娄底市厨余垃圾处置过程为研究对象,基于生命周期评价方法分析处置过程各个环节对环境和能源的影响,解析各功能单元的环境影响贡献,并结合经济性分析提出优化方案。结果表明,厨余垃圾处置过程对环境酸化潜值、人体毒性和水生生态毒性、富营养化和陆地生态毒性等方面具有一定程度的负面影响,主要是由于污水净化阶段带来的负面效应,处置过程中的非生物资源消耗主要源于污水净化过程中所使用的碱性物质和运输转运过程中的化石能源消耗,而沼气利用过程所产生的收益则可在一定程度上抵消对环境产生的负面影响。与沼渣焚烧工艺相对比,沼渣堆肥工艺的碳排放降低了54%,其他废气排放降低了76%,同时可增加11 827 t有机肥,具有明显的环境优势和副产物优势。结合经济性分析,可从减少能耗、增加沼气产气率、回收粗油和沼渣等副产品方面着手,尽可能提高厨余垃圾处置过程的环境效益和经济效益。

心理痛苦温度计在血液病患儿中的临床实用性研究

目的基于临床效用多维模型,从可及性、适宜性、可行性和可接受性4个方面探讨心理痛苦温度计在血液病患儿中的临床实用性,为临床评估血液病患儿心理痛苦提供可用工具。方法便利抽样法选取125例血液病患儿,采用一般情况调查表、中文版心理痛苦温度计和儿童抑郁量表进行调查。结果问卷有效回收率为92.59%;患儿对心理痛苦温度计理解程度和作用评价均分均>2.3分;以儿童抑郁量表为金标准,心理痛苦温度计得分3.5分时,灵敏度和特异度分别为0.905、0.635。结论心理痛苦温度计在血液病患儿中具有较好的临床实用性,可作为该群体心理痛苦的有效评估工具。

综合能源生产单元的全生命周期碳足迹评价与技术经济性评估

综合能源生产单元(integrated energy production unit,IEPU)通过耦合可再生能源制氢与火电碳捕集技术,制备易于储运的绿色燃料,在协调解决可再生能源消纳、碳利用及氢能储运等问题方面具有良好的应用前景。为定量评价IEPU的技术经济性与降碳潜力,该文通过构建IEPU工艺流程的仿真模型,模拟风电制氢、甲醇合成及压缩提纯等关键过程,建立多能流与物料流数据的全生命周期清单,进行碳足迹评价,并指出进一步碳减排的可行路径;通过对能量效率、电流密度等技术参数及风电价格、碳税等经济参数进行灵敏度分析,开展不同技术经济性背景下的经济性评估,探究IEPU的盈利条件。碳足迹评价表明,年产39万t绿色甲醇IEPU的全生命周期净碳减排量达5.88万t。技术经济性评估表明,在良好的技术经济性背景下,当风电售价降低至0.21元/(kW×h),基于IEPU生产的绿色甲醇成本可与传统甲醇生产工艺相当。

建筑垃圾资源化利用及其生命周期评价的研究进展

从中国知网(CNKI)与Web of Science数据库中检索国内外关于建筑垃圾资源化利用及其生命周期评价(LCA)的相关文献,系统归纳了国内外建筑垃圾分类和资源化利用技术现状,并对LCA方法及相关模型在建筑垃圾资源化利用中的研究进展及应用情况进行了综述。结果表明,LCA方法是量化建筑垃圾管理体系环境效应的重要方法之一,能够科学评估建筑垃圾资源化利用的能源消耗、环境排放以及再生循环产品效益等,是建筑垃圾可持续管理和“无废城市”建设的重要基础。中国在建筑垃圾资源化利用、LCA模型开发及与其他研究方法集成方面还需继续探索,在建筑垃圾源头减量和建筑垃圾回收体系建立等方面仍面临巨大挑战。

综合管廊电力舱电缆火灾研究进展

综合管廊的电力运营输送安全是韧性城市的重要保证措施之一。在分析电力舱火灾成因、火灾特点及消防安全特殊性的基础上,归纳了综合管廊电力舱电缆火灾的关键科学问题。从电缆火灾的燃烧动力学机理、风险评估以及预警防护3个方面,综述了管廊电力舱火灾安全的研究成果和总体进展。结果表明:在电力舱电缆火灾的基础理论和实践应用上已经取得了较为系统的研究成果,但关于复杂廊体结构因素对火灾的影响研究还缺乏深入的探讨。结合管廊行业实际工程的发展,指出长通风区间电力舱电缆火灾的蔓延及联动防治是未来综合管廊消防系统研究的一个重要方向。

基于文献回顾的有色金属冶炼废渣的特征、资源化途径及其安全利用评价

冶炼废渣作为冶炼过程中产生的工业副产物,由于其缺乏安全、合理的防护和管理措施可能导致环境问题。通过全面分析近年来发表的相关文献,本文对有色金属冶炼废渣的特性、资源化利用途径及安全利用评价等方面的最新研究进展进行了介绍。研究结果表明,不同的原生精矿、冶炼条件和冶炼类型决定了冶炼废渣的化学和矿物学特征。此外,冶炼废渣在各种资源化利用中表现出极高的灵活性,不仅可以用于金属回收和建筑材料,还可以作为农业肥料和修复剂。同时,本文强调了在各种利用情景下对废渣进行安全性评估的重要性,以降低其潜在环境风险。此外,本文还强调了未来的研究方向,包括建立一种综合且量化的土渣混合体中重金属环境风险评价方法,以及探索更多创新的冶炼废渣资源化利用方法。综上所述,本文对于推动冶炼废渣在环境保护和资源可持续利用方面的研究有重要意义。