Reliability-based life-cycle cost seismic design optimization of coastal bridge piers with nonuniform corrosion using different materials

Reinforcement corrosion is the main cause of performance deterioration of reinforced concrete(RC)structures.Limited research has been performed to investigate the life-cycle cost(LCC)of coastal bridge piers with nonuniform corrosion using different materials.In this study,a reliability-based design optimization(RBDO)procedure is improved for the design of coastal bridge piers using six groups of commonly used materials,i.e.,normal performance concrete(NPC)with black steel(BS)rebar,high strength steel(HSS)rebar,epoxy coated(EC)rebar,and stainless steel(SS)rebar(named NPC-BS,NPC-HSS,NPC-EC,and NPC-SS,respectively),NPC with BS with silane soakage on the pier surface(named NPC-Silane),and high-performance concrete(HPC)with BS rebar(named HPC-BS).First,the RBDO procedure is improved for the design optimization of coastal bridge piers,and a bridge is selected to illustrate the procedure.Then,reliability analysis of the pier designed with each group of materials is carried out to obtain the time-dependent reliability in terms of the ultimate and serviceability performances.Next,the repair time of the pier is predicted based on the time-dependent reliability indices.Finally,the time-dependent LCCs for the pier are obtained for the selection of the optimal design.

Characterization and evaluation of brittleness of deep bedded sandstone from the perspective of the whole life-cycle evolution process

The quantitative determination and evaluation of rock brittleness are crucial for the estimation of excavation efficiency and the improvement of hydraulic fracturing efficiency.Therefore,a“three-stage”triaxial loading and unloading stress path is designed and proposed.Subsequently,six brittleness indices are selected.In addition,the evolution characteristics of the six brittleness indices selected are characterized based on the bedding effect and the effect of confining pressure.Then,the entropy weight method(EWM)is introduced to assign weight to the six brittleness indices,and the comprehensive brittleness index Bcis defined and evaluated.Next,the new brittleness classification standard is determined,and the brittleness differences between the two stress paths are quantified.Finally,compared with the previous evaluation methods,the rationality of the proposed comprehensive brittleness index Bcis also verified.These results indicate that the proposed brittleness index Bccan reflect the brittle characteristics of deep bedded sandstone from the perspective of the whole life-cycle evolution process.Accordingly,the method proposed seems to offer reliable evaluations of the brittleness of deep bedded sandstone in deep engineering practices,although further validation is necessary.

A Blockchain-Based Life-Cycle Environmental Management Framework for Hospitals in the COVID-19 Context

During the coronavirus disease 2019 (COVID-19) emergency, many hospitals were built or renovated around the world to meet the challenges posed by the rising number of infected cases. Environmental management in the hospital life cycle is vital in preventing nosocomial infection and includes many infection control procedures. In certain urgent situations, a hospital must be completed quickly, and work process approval and supervision must therefore be accelerated. Thus, many works cannot be checked in detail. This results in a lack of work liability control and increases the difficulty of ensuring the fulfillment of key infection prevention measures. This study investigates how blockchain technology can transform the work quality inspection workflow to assist in nosocomial infection control under a fast delivery requirement. A blockchain-based life-cycle environmental management framework is proposed to track the fulfillment of crucial infection control measures in the design, construction, and operation stages of hospitals. The proposed framework allows for work quality checking after the work is completed, when some work cannot be checked on time. Illustrative use cases are selected to demonstrate the capabilities of the developed solution. This study provides new insights into applying blockchain technology to address the challenge of environmental management brought by rapid delivery requirements.

An updated inventory of marine opisthobranch(Mollusca,Gastropoda)from the territorial waters of the Republic of Mauritius

Island ecosystems support diverse aquatic invertebrate communities comprising endemic taxa.Documentation of existing species is important for conservation.In this study,a checklist of marine opisthobranch from the Republic of Mauritius is presented.A combination of benthic surveys(50 m×5 m in triplicates),rover diving techniques and photo documentation were used over two years(2018–2020)within 35 sheltered and unsheltered lagoons.Morphological and molecular analysis were used for identification.Species composition within sheltered and unsheltered areas in Mauritius was estimated using the Bray-Curtis similarity.The checklist featured 117 species belonging to 61 genera and 28families,of which 13 are new records.The findings increased the knowledge of opisthobranch diversity from the Mauritius by 15.4%.Among the listed species,the distribution range of Cyerce nigra,Actinocyclus papillatus,and Phyllidia picta extended from the Western Pacific to the South Western Indian Ocean.Molecular analysis of the undescribed Gymnodoris sp.showed it resembled Gymnodoris sp.from Hawaii and were different by a genetic distance value of 10.6%.The species richness and evenness were higher within the sheltered regions of Mauritius which harboured the food resource of opisthobranch.These areas as compared to unsheltered regions were heavily populated,suggesting the probable influence of wave actions on opisthobranch diversity and abundance.The order Nudibranchia was reported as most speciose,with 86 species.The Sacoglossa and Nudibranchia were observed only on macroalgae and sponges respectively.High abundance was also recorded on shipwrecks which are the most common form of artificial reefs.With the inclusion of observations from previous studies,201species belonging to 94 genera and 36 families are now known from the Mauritius.

Intelligent Decision-Making in Warehouse Management: How AI Automation Improves Inventory Tracking, Order Fulfillment, and Logistics Efficiency Compared to Drone Technology

This paper analyzes how artificial intelligence (AI) automation can improve warehouse management compared to emerging technologies like drone usage. Specifically, we evaluate AI’s impact on crucial warehouse functions—inventory tracking, order fulfillment, and logistics efficiency. Our findings indicate AI automation enables real-time inventory visibility, optimized picking routes, and dynamic delivery scheduling, which drones cannot match. AI better leverages data insights for intelligent decision-making across warehouse operations, supporting improved productivity and lower operating costs.

A Note on an Order Level Inventory Model with Varying Two-Phased Demand and Time-Proportional Deterioration

The main purpose of this paper is to generalize the effect of two-phased demand and variable deterioration within the EOQ (Economic Order Quantity) framework. The rate of deterioration is a linear function of time. The two-phased demand function states the constant function for a certain period and the quadratic function of time for the rest part of the cycle time. No shortages as well as partial backlogging are allowed to occur. The mathematical expressions are derived for determining the optimal cycle time, order quantity and total cost function. An easy-to-use working procedure is provided to calculate the above quantities. A couple of numerical examples are cited to explain the theoretical results and sensitivity analysis of some selected examples is carried out.

Life-cycle failure probability analysis of deteriorated RC bridges under multiple hazards of earthquakes and strong winds

Engineering structures may be exposed to one or more extreme hazards during their life-cycles.Current structural design specifications usually treat multiple hazards separately in designing structures and there is a limited probabilistic basis on extreme load combinations.Additionally,the performance of engineering structures will be deteriorated by the aggressive environments during their service periods,such as chloride attack,concrete carbonation,and wind-induced fatigue.This study presents a probabilistic methodology to assess the time-dependent failure probability of RC bridges with chloride-induced corrosion under the multiple hazards of earthquakes and strong winds.The loss of cross-section area of reinforcements and the reduction in strength of reinforcing steel and concrete cover induced by the chloride attack are considered.Moreover,the Poisson model is employed to obtain the occurrence probabilities of the individual and concurrent earthquake and strong wind events.The convolution integral is used to determine the joint probability distribution of combined load effects under simultaneous earthquakes and strong winds.Numerical results indicate that the structural failure probability under multiple hazards increases significantly during the bridge′s life-cycle due to the chloride corrosion effect.The contribution of each hazard event on the total structural failure probability varies with time.Thus,neglecting the combined influences of multiple hazards and chloride-induced corrosion may bring erroneous predictions in failure probability estimates of RC bridges.

An open-accessed inventory of landslides triggered by the M_(S)6.8 Luding earthquake,China on September 5,2022

This study constructs a preliminary inventory of landslides triggered by the M_(S) 6.8 Luding earthquake based on field investigation and human-computer interaction visual interpretation on optical satellite images.The results show that this earthquake triggered at least 5007 landslides,with a total landslide area of 17.36 km^(2),of which the smallest landslide area is 65 m^(2)and the largest landslide area reaches 120747 m^(2),with an average landslide area of about 3500 m^(2).The obtained landslides are concentrated in the IX intensity zone and the northeast side of the seismogenic fault,and the area density and point density of landslides are 13.8%,and 35.73 km^(-2) peaks with 2 km as the search radius.It should be noted that the number of landslides obtained in this paper will be lower than the actual situation because some areas are covered by clouds and there are no available post-earthquake remote sensing images.Based on the available post-earthquake remote sensing images,the number of landslides triggered by this earthquake is roughly estimated to be up to 10000.This study can be used to support further research on the distribution pattern and risk evaluation of the coseismic landslides in the region,and the prevention and control of landslide hazards in the seismic area.

Life-cycle CO_2 Emissions and Their Driving Factors in Construction Sector in China

As the construction sector is a major energy consumer and thus a significant contributor of CO_2 emissions in China,it is important to consider carbon reduction in this industry.This study analyzed six life-cycle stages and calculated the life-cycle CO_2 emissions of the construction sector in 30 Chinese provincial jurisdictions to understand the disparity among them.Results show that building materials production was the key stage for carbon reduction in the construction sector,followed by the building operation stage.External variables,e.g.,economic growth,industrial structure,urbanization,price fluctuation,and marketization,were significantly correlated with the emission intensity of the construction sector.Specifically,economic growth exhibited an inverted U-shaped relation with CO_2 emissions per capita and per area during the period examined.Secondary industry and land urbanization were negatively correlated with CO_2 emission intensity indicators from the construction sector,whereas tertiary industry and urbanization were positively correlated.Price indices and marketization had negative effects on CO_2 emission intensity.The policy implications of our findings are that cleaner technologies should be encouraged for cement providers,and green purchasing rules for the construction sector should also be established.Pricing tools(e.g.,resource taxes)could help to adjust the demand for raw materials and energy.

Spatial distribution and inventory of natural gas hydrate in the Qiongdongnan Basin,northern South China Sea

Natural gas hydrate is a potential clean energy source and is related to submarine geohazard,climate change,and global carbon cycle.Multidisciplinary investigations have revealed the occurrence of hydrate in the Qiongdongnan Basin,northern South China Sea.However,the spatial distribution,controlling factors,and favorable areas are not well defined.Here we use the available high-resolution seismic lines,well logging,and heat flow data to explore the issues by calculating the thickness of gas hydrate stability zone(GHSZ)and estimating the inventory.Results show that the GHSZ thickness ranges between mostly~200 and 400 m at water depths>500 m.The gas hydrate inventory is~6.5×109-t carbon over an area of~6×104 km2.Three areas including the lower uplift to the south of the Lingshui sub-basin,the Songnan and Baodao sub-basins,and the Changchang sub-basin have a thick GHSZ of~250-310 m,250-330 m,and 350-400 m,respectively,where water depths are~1000-1600 m,1000-2000 m,and2400-3000 m,respectively.In these deep waters,bottom water temperatures vary slightly from~4 to 2℃.However,heat flow increases significantly with water depth and reaches the highest value of~80-100 mW/m2 in the deepest water area of Changchang sub-basin.High heat flow tends to reduce GHSZ thickness,but the thickest GHSZ still occurs in the Changchang sub-basin,highlighting the role of water depth in controlling GHSZ.The lower uplift to the south of the Lingshui sub-basin has high deposition rate(~270-830 m/Ma in 1.8-0 Ma);the thick Cenozoic sediment,rich biogenic and thermogenic gas supplies,and excellent transport systems(faults,diapirs,and gas chimneys)enables it a promising area of hydrate accumulation,from which hydrate-related bottom simulating reflectors,gas chimneys,and active cold seeps were widely revealed.

The Environmental Impacts and Economic Benefits on Comprehensively Promoting Alternative Fuel Buses in China: Life-Cycle and Scenario Analysis Based on LEAP Model

With the continuous development of urban public transportation, the harmful GHG emissions and pollutants generated by itself and the consequent issues such as the losses of residents’ health, economic value and residents’ welfare have become the focus of social attention. In order to study the impacts of promoting new energy vehicles on public transportation pollution mitigation and residents’ health benefits, this paper adopts the LEAP model to build some scenarios that fulfill different development needs to quantitatively analyze the ownership of new energy buses, the reduction of pollutants and the losses of residents’ health welfare. It is concluded that promoting new energy buses comprehensively can significantly reduce the emissions of atmospheric pollutants and the economic losses of residents’ health, but cannot fully realize the targets of greenhouse gas reduction under Life Cycle Analysis.

Inventory of Host Plants and Parasitoids of the Fall Armyworm (FAW), Spodoptera frugiperda (JE Smith), in the Southern Agricultural Zone of Niger

The fall armyworm, Spodoptera frugiperda (JE Smith), is a polyphagous pest reported in sub-Saharan Africa since 2016 and has expanded rapidly in almost Africa. In Niger, Spodoptera frugiperda (JE Smith) is considered like a major pest of maize, to which it causes significant damage, in a context where proven control methods against this moth remain almost non-existent. The objective of the present study was to determine the economic importance of FAW through the damage caused to the different host plants and to identify the parasitoids of this caterpillar. The study was conducted in the southern agricultural zone of Niger, specifically in the regions of Dosso, Maradi, Tahoua and Zinder. FAW eggs and caterpillars were collected from six villages in each region and then incubated and reared in the entomology laboratory of INRAN in Maradi. The rate of infestation of the different crops by FAW was determined as well as the observation of the beneficiaries. The results obtained indicate the presence of FAW on millet with an attack rate varying from 45.7% to 68%, sorghum with 47.2% to 62.25% and sesame with 9.7%. This work also revealed an oophagous parasitoid, Telenomus remus with 138 ± 23 and larval parasitoids, Cotesia sp with 16 ± 1 maximum number of individuals emerged from the collected material. Also, it was identified the parasitoid Cotesia icipe with a rate of parasitism from 4.6% to 5.75%;the Charops ater whose rate of parasitism varies from 4.5% and 12.25% but for Chelonus insularis with 17.25% and Tachnidae with 53%. These very interesting results will constitute a basis for the development of biological control and a component of an agroecological management strategy of caterpillar.

Screening Tree Species for Carbon Storage Potential through Urban Tree Inventory in Planted Vegetation

Urban tree inventory is a great tool for gathering data that can be used by different end users. This study attempted to chart the species diversity in planted areas and measure their tree diameter at breast height to screen them for the carbon storage potential. A total of 2860 trees belonging to 36 species were recorded in the planted vegetation in parks and avenue plantation. The dominant species were Azadirachta indicia (25.5%), Conocarpus erectus (19.2%), Ficus spp. (15.5%), Tabebuia rosea (9.2%), Peitophorum pterocarpum (9.0%) and the remaining represents (21.6%) of the tree identified in this study. It was found that the highest contribution of carbon sequestration (CO2 equivalent) is dominated by the Ficus spp. (30.3%) with a total of 3399.3 tCO2eq, followed by Azadirachta indicia (25.4%) with a total of 2845.2 tCO2eq and Conocarpus erectus (20.4%) with a total of 2286 tCO2eq. The entire area has the capability to sequester around 11,213.3 tCO2eq and on average of 3.9 ± 0.1 tCO2eq. In accordance with the findings, it is imperative for the preservation of a sustainable environment to have vegetation that has the capacity to store carbon. The study suggests, there is potential to increase carbon sequestration in urban cities through plantation programs on existing and new land uses and along roads.

Inventory of the Thermo-Physiological Behavior of Fabrics—A Review

A comprehensive literature review was performed to create an inventory of thermal-physiological quantities for fabrics from different fiber materials, material blends, and fabric structures. The goal was to derive over-arching concepts that cannot be seen by the individual studies alone. Equations of best fits suggest non-linear changes for fabric thickness, thermal and water-vapor resistance with changes in material blend ratio. Air permeability decreases with increasing fabric density and fabric weight wherein the degree of decrease differs among fabric materials, blend ratio, and fabric structure. Water-vapor transmission rates strongly depend on fabric thickness, material, and blend, but marginally depend on fabric structure as long as the fabric and material thickness remain the same.

考虑资源稀缺性的路面养护措施综合效益全寿命周期费用评估

为提高道路工程中不可再生资源利用的合理性,建立养护措施综合效益的全寿命周期费用评价方法,推动交通运输基础设施的可持续发展,基于全寿命周期费用评价(life-cycle cost assessment,LCCA)理论,引入了资源稀缺性的评价指标,并基于存量稀缺、进口稀缺和技术稀缺3个评价维度,建立了适用于路用材料的项目级资源稀缺性评价体系,同时,将该指标量化为货币当量计入成本清单中。依托江苏省路面养护管理系统数据,将资源稀缺性、经济效益、性能发展3个维度统一,定量分析了再生类、铣刨重铺类和罩面类共3类、12个常见养护措施的综合效益。研究结果表明:考虑资源稀缺性,再生类养护措施旧料利用率较高,具有极佳的资源合理性;EC A-10薄层罩面处治厚度薄、耗材量小,与普通罩面相比能节省50%左右的资源;铣刨料直接废弃、石料来源选择不当将导致额外支出10%~20%的当量成本。考虑综合效益,各养护方案与施工特性(如施工工期、施工水平、工艺先进性等)相关的成本效益接近60%,其中用户间接的经济损失占比超过30%,直接由施工工期决定。因此,建议谨慎选择材料来源及去向以减少不可再生资源浪费,优化养护施工流程以降低用户的间接经济损失,提高施工水平以降低用户的直接油耗开支,开展科学养护决策以降低政府投入成本。

城市存量土地更新的动力机制研究

随着城市化的加速发展,城市面临着空间资源有限、环境压力不断加大的问题。城市存量土地更新成为优化城市发展格局、提高资源利用效率的重要手段。论文阐述了城市存量土地的内涵,分析了城市存量土地类型与基本特征,构建了“权力—资本—民生”三大驱动力交互作用影响的更新动力分析框架,重点分析讨论了居住类存量土地的“政府+社会”协作更新机制、产业类存量土地的“政府+市场”协作更新机制、公共设施类存量土地的政府主导更新机制、公共空间类存量土地的政府主导更新机制以及历史文化类存量土地的多方协作更新机制等五种更新驱动作用机制,以期为城市存量土地更新制度设计与治理优化路径制定提供依据,更好地推动城市更新的协同、健康与可持续发展。

我国垃圾填埋碳排放核算标准的编制建议

填埋作为我国主要的垃圾处理方式之一,是碳排放的重要来源;编制我国垃圾填埋碳排放核算标准,将支持碳排放统计核算体系建设,推进碳达峰、碳中和目标进程。本文梳理了国内外垃圾填埋碳排放核算的相关标准和指南研制进展,分析了我国垃圾填埋碳排放核算标准编制面临的挑战,在深入讨论相关标准的基准方法、编制重点任务的基础上提出了有关发展建议。研究认为,国际上已有的标准和指南以及提供的缺省值不完全适用于我国垃圾填埋碳排放核算的实际情况,目前我国缺少规范统一的垃圾填埋碳排放核算方法,也缺乏可靠的核算清单数据。为此,针对我国填埋垃圾特征和技术现状,提出了我国垃圾填埋碳排放核算方法、核算范围和清单的建议内容;明晰了我国垃圾填埋碳排放核算标准编制的重点任务,提供了适合我国垃圾填埋场景的清单数据获取方式。后续,可充分考虑地区因素,采用我国特征性数据,以获得更贴合实际情况的垃圾填埋碳排放核算结果,据此开展我国垃圾填埋碳排放核算标准的编制工作。

老年抑郁问卷在心力衰竭患者中的应用性评估

目的:评估老年抑郁问卷(geriatric depression inventory,GDI)在老年心力衰竭患者中进行抑郁障碍筛查的价值,确定最佳划界分。方法:采用方便抽样法,选取2017年9月至2018年12月期间,在北京市三家综合医院就诊的老年心力衰竭患者,共195例接受了GDI评估。以中文版简明国际神经精神访谈(mini-international neuropsychiatric interview,M.I.N.I.)为“金标准”。结果:根据M.I.N.I.结果,受试者被分为抑郁障碍组(共90例,其中包括52例重性抑郁障碍,30例轻性抑郁障碍,8例心境恶劣)和非抑郁障碍组(105例)。GDI的ROC曲线下面积为0.98(SE=0.01,95%CI:0.97~1.00,P<0.01)。最佳划界分为5分,此时灵敏度和特异度均为93.3%,阳性预测值和阴性预测值分别为94.5%和94.2%。结论:GDI在老年心力衰竭人群进行抑郁障碍筛查时筛查价值高,可在该人群中进行推广,最佳划界分为5分。

人工耳蜗植入对成人语后聋患者植入侧耳鸣的影响

目的 探究成人语后聋患者人工耳蜗植入术后植入侧耳鸣的变化,并分析其影响因素。方法 2017年1月~2021年12月于郑州大学第一附属医院耳科进行单侧人工耳蜗植入的47例成人语后聋伴耳鸣患者,分别于术前和术后开机6个月进行耳鸣问卷评估,评估材料为耳鸣障碍量表(tinnitus handicap inventory,THI)和视觉模拟量表(visual analogue scale,VAS),比较人工耳蜗植入术后患者耳鸣的变化,并分析其可能的影响因素。结果 47例患者人工耳蜗植入术前、术后开机6个月时THI评分别为36.94±13.337、14.48±12.726分,VAS评分分别为5.13±1.676、2.34±1.903分,术后评分均较术前降低,差异均有统计学意义(P<0.05);其中18例患者耳鸣完全消失,13例患者耳鸣减轻,14例患者耳鸣无变化,2例患者耳鸣加重,总体耳鸣有效率为66.0%(31/47);术前耳鸣病程与耳鸣严重程度对术后耳鸣预后有影响(P<0.05),术前耳鸣病程≤5年、中度及以上耳鸣组耳鸣有效率分别高于耳鸣病程>5年(P<0.05)、轻微及轻度耳鸣组(P<0.001)。结论 人工耳蜗植入对成年语后聋患者植入侧耳鸣具有抑制作用;术前耳鸣病程短、耳鸣程度重的患者术后耳鸣改善的可能性更大。

基于EOQ模型传统涉外制造企业物料库存管理研究

库存成本管理水平高低对企业经营成本有着直接影响,提高库存管理水平,有助于降低库存成本和经营成本。文章基于EOQ模型,以传统涉外制造企业DJ公司为例,选取物料面浆作为研究对象,通过对EOQ模型使用前后库存成本对比分析,发现采用EOQ模型后,面浆的库存量和库存总成本比原来有所降低。研究表明,科学合理采用EOQ模型有助于实现订货成本与维持成本最小化,降低企业经营成本,促进企业可持续发展。