Pile foundation in alternate layered liquefiable and non-liquefiable soil deposits subjected to earthquake loading

Pile foundations are still the preferred foundation system for high-rise structures in earthquake-prone regions.Pile foundations have experienced failures in past earthquakes due to liquefaction.Research on pile foundations in liquefiable soils has primarily focused on the pile foundation behavior in two or three-layered soil profiles.However,in natural occurrence,it may occur in alternative layers of liquefiable and non-liquefiable soil.However,the experimental and/or numerical studies on the layered effect on pile foundations have not been widely addressed in the literature.Most of the design codes across the world do not explicitly mention the effect of sandwiched non-liquefiable soil layers on the pile response.In the present study,the behavior of an end-bearing pile in layered liquefiable and non-liquefiable soil deposit is studied numerically.This study found that the kinematic bending moment is higher and governs the design when the effect of the sandwiched non-liquefied layer is considered in the analysis as opposed to when its effect is ignored.Therefore,ignoring the effect of the sandwiched non-liquefied layer in a liquefiable soil deposit might be a nonconservative design approach.

The presence and partitioning behavior of flame retardants in waste,leachate,and air particles from Norwegian waste-handling facilities

Flame retardants in commercial products eventually make their way into the waste stream.Herein the presence of flame retardants in Norwegian landfills, incineration facilities and recycling sorting/defragmenting facilities is investigated. These facilities handled waste electrical and electronic equipment（WEEE）, vehicles, digestate, glass, combustibles, bottom ash and fly ash. The flame retardants considered included polybrominated diphenyl ethers（∑BDE-10） as well as dechlorane plus, polybrominated biphenyls, hexabromobenzene,pentabromotoluene and pentabromoethylbenzene（collectively referred to as ∑FR-7）. Plastic,WEEE and vehicles contained the largest amount of flame retardants（∑BDE-10： 45,000–210,000 μg/kg; ∑FR-7： 300–13,000 μg/kg）. It was hypothesized leachate and air concentrations from facilities that sort/defragment WEEE and vehicles would be the highest. This was supported for total air phase concentrations（∑BDE-10： 9000–195,000 pg/m^3 WEEE/vehicle facilities, 80–900 pg/m^3 in incineration/sorting and landfill sites）, but not for water leachate concentrations（e.g., ∑BDE-10： 15–3500 ng/L in WEEE/Vehicle facilities and 1–250 ng/L in landfill sites）. Landfill leachate exhibited similar concentrations as WEEE/vehicle sorting and defragmenting facility leachate. To better account for concentrations in leachates at the different facilities, waste-water partitioning coefficients, Kwastewere measured（for the first time to our knowledge for flame retardants）. WEEE and plastic waste had elevated Kwastecompared to other wastes, likely because flame retardants are directly added to these materials. The results of this study have implications for the development of strategies to reduce exposure and environmental emissions of flame retardants in waste and recycled products through improved waste management practices.

Distribution patterns of fire regime in the Pendjari Biosphere Reserve, West Africa

Pendjari Biosphere Reserve(PBR),a primary component of the W-Arly-Pendjari transboundary biosphere reserve,represents the largest intact wild ecosystem and pristine biodiversity spot in West Africa.This savannah ecosystem has long been affected by fire,which is the main ecological driver for the annual rhythm of life in the reserve.Understanding the fire distribution patterns will help to improve its management plan in the region.This study explores the fire regime in the PRB during 2001–2021 in terms of burned area,seasonality,fire frequency,and mean fire return interval(MFRI)by analysing moderate resolution imaging spectroradiometer(MODIS)burned area product.Results indicated that the fire season in the PBR extends from October to May with a peak in early dry season(November–December).The last two fire seasons(2019–2020 and 2020–2021)recorded the highest areas burned in the PBR out of the twenty fire seasons studied.During the twenty years period,8.2%of the reserve burned every 10–11 months and 11.5%burned annually.The largest part of the reserve burned every one to two years(63.1%),while 8.3%burned every two to four years,5.8%burned every four to ten years,and 1.9%burned every ten to twenty years.Only 1.3%of the entire area did not fire during the whole study period.Fire returned to a particular site every 1.39 a and the annual percentage of area burned in the PBR was 71.9%.The MFRI(MFRI<2.00 a)was low in grasslands,shrub savannah,tree savannah,woodland savannah,and rock vegetation.Fire regime must be maintained to preserve the integrity of the PBR.In this context,we suggest applying early fire in tree and woodland savannahs to lower grass height,and late dry season fires every two to three years in shrub savannah to limit the expansion of shrubs and bushes.We propose a laissez-faire system in areas in woodland savannah where the fire frequency is sufficient to allow tree growth.Our findings highlight the utility of remote sensing in defining the geographical and temporal patterns of fire in the PBR and could help to manage this important fire prone area.

离子聚合物-金属复合材料(IPMC)的电极界面研究进展

离子聚合物-金属复合材料(Ionic polymer-metal composites,IPMC)是一种新型的智能材料,由于其具有良好的机电转换能力且本体柔软,可以制作成多种驱动器和传感器,因而在各个领域中展示出巨大的应用潜力。这种材料的机电性能受多种因素影响,其电极界面是重要影响因素之一。文章回顾了近几年来国内外针对IPMC材料的界面电极特性所做的研究工作,归纳了优化电极界面的主要措施,并提出一种有效提高IPMC材料电极界面的制备工艺设计思路。

各级打叶风分单元分离片烟的尺寸分布变化规律

利用五打十一分打叶机组对上部烟配打模块进行梗叶分离,研究了打叶去梗工序中各级打叶风分后片烟的尺寸分布变化规律。结果表明:各级打叶风分单元分离出的片烟尺寸在各面积区间内的比例变化趋势基本一致;其中第一、二级打叶单元内各风分口的大中片比例均>94%,较为稳定,且片烟特征尺寸及超大片比例均随风分级数的增加呈上升趋势,第三、四/五级打叶单元内片烟特征尺寸及超大片比例显著降低,小片率明显升高;各级打叶单元汇总片烟的特征尺寸及均匀性随打叶级数增加逐渐降低。

机场自动旅客输送系统规划技术及其应用

介绍了机场自动旅客输送系统的一般规划技术。规划技术涉及交通规划、运输组织、线路设计、车站布局以及辅助设施规划等内容。该技术方法已应用于上海浦东国际机场自动旅客输送系统的前期规划阶段。本项研究有助于今后国内机场自动旅客输送系统实施建设。

新型人工浮岛强化降解污染物机理及应用研究

分别构建了传统人工浮岛和新型人工浮岛2组系统,对比考察了对主要污染物的去除效果,分析了对污染物降解的机理,比较了植株高度、根系生长及填料降解情况。结果表明,2组人工浮岛对去除COD、TN、NO3^--N、NH4^+-N等4个水质指标的差异明显(p<0.05),新型人工浮岛系统对TP的去除率为94.55%,且对TN、NO3^--N的去除效果要显著高于传统人工浮岛,其去除率分别达到了83.39%和81.50%。丝瓜络、玉米芯的添加和降解增大了污水的可生化性,强化了新型人工浮岛的脱氮除磷效果;种植了千屈菜的新型人工浮岛植株生长高度为传统人工浮岛的2.36倍。

蓝宝石的光致变色效应

针对近年来困扰市场的蓝宝石褪色、变色问题,以无优化处理天然蓝宝石、热处理天然蓝宝石以及合成蓝宝石作为研究对象,开展了多种光源的照射试验以及紫外-可见光谱、荧光光谱、电子顺磁共振谱和红外光谱测试分析,探究蓝宝石光致变色效应的行为与机制。测试结果表明,部分蓝宝石经长波紫外线、短波紫外线或X射线照射后,诱生出缺陷色心,形成以蓝区至绿区为中心、从紫外区延伸至红区约750nm处的宽大吸收带,赋予蓝宝石褐(橙)色调,并降低蓝宝石明度;白光照射可使该吸收带缓慢漂白,从而使蓝宝石褪色。在此基础上,提出了蓝宝石光致变色效应的基本模型,指出蓝宝石所处光环境中白光与紫外线成分的比例决定了蓝宝石的颜色表现,地理位置改变和室内存放展示往往导致蓝宝石颜色发生变化。通过对几种光致变色光源进行对比分析,厘清了天然致色与人工辐照致色的划分界限,指出了天然致色的鉴别指征。此外,在合成蓝宝石中发现了罕见的红外波段"光致变色"现象。

Dyslipidemia and cardiovascular disease risk factors in patients with type 1 diabetes:A single-center experience

BACKGROUND Type 1 diabetes(T1D)contributes to altered lipid profiles and increases the risk of cardiovascular disease(CVD).Youth with T1D may have additional CVD risk factors within the first decade of diagnosis.AIM To examine risk factors for dyslipidemia in young subjects with T1D.METHODS Longitudinal and cross-sectional retrospective study of 170 young subjects with T1D(86 males;baseline mean age 12.2±5.6 years and hemoglobin A1c 8.4%±1.4%)were followed in a single tertiary diabetes center for a median duration of 15 years.Predictors for outcomes of lipid profiles at last visit(total cholesterol[TC],triglycerides[TGs],low-density lipoprotein-cholesterol[LDL-c],and highdensity lipoprotein-cholesterol[HDL-c])were analyzed by stepwise linear regression models.RESULTS At baseline,79.5%of the patients had at least one additional CVD risk factor(borderline dyslipidemia/dyslipidemia[37.5%],pre-hypertension/hypertension[27.6%],and overweight/obesity[16.5%])and 41.6%had multiple(≥2)CVD risk factors.A positive family history of at least one CVD risk factor in a first-degree relative was reported in 54.1%of the cohort.Predictors of elevated TC:family history of CVD(β[SE]=23.1[8.3],P=0.006);of elevated LDL-c:baseline diastolic blood pressure(DBP)(β[SE]=11.4[4.7],P=0.003)and family history of CVD(β[SE]=20.7[6.8],P=0.017);of elevated TGs:baseline DBP(β[SE]=23.8[9.1],P=0.010)and family history of CVD(β[SE]=31.0[13.1],P=0.020);and of low HDL-c levels:baseline DBP(β[SE]=4.8[2.1],P=0.022]).CONCLUSION Our findings suggest that elevated lipid profiles are associated with DBP and a positive family history of CVD.It is of utmost importance to prevent and control modifiable risk factors such as these,as early as childhood,given that inadequate glycemic control and elevation in blood pressure intensify the risk of dyslipidemia.

碱面条松散装置方案设计及仿真分析

设计了一种适用于碱面条自动化生产的碱面条松散装置,对其总体方案进行了研究,并对其内壁带有多个搅拌杆的滚筒、滚轮及支架、传动带等进行了结构设计。利用Adams软件对碱面条松散装置进行建模,通过运动学仿真从滚筒转速和角加速度2个方面验证了设计的合理性;通过动力学仿真测试了传动带的接触力及滚轮接触力,为碱面条松散装置的优化设计及构建碱面条的自动化生产线提供了参考依据。

Improving the Thermal Comfort of a Building by Adding a Layer of Straw over the High Floor

This document deals with the thermal characterization of a building with a layer of straw above the high floor. In the current environmental context, in Senegal, buildings are the biggest consumers of energy. This is due to the construction materials used. Almost of buildings in Senegal used concrete (cement + aggregates) as based material construction. Due to this, the buildings require air conditioning or artificial ventilation to ensure minimum comfort. In face of this situation, it becomes useful to propose methods for reducing this high energy consumption. In this work, we propose to add a layer of straw above the high floor of a building in Matam city (North Senegal). In this case, we designed and modeled one building of single room in which the walls are in briks and a concrete slab. A bale of straw is layered on this slab in order to determine its influence on the energy consumption of the building. This study shows that the straw has a strong influence on the energy consumption of a building and the slab + straw building is more energy efficient than the bare slab building.

Comparison of SCS-CN Determination Methodologies in a Heterogeneous Catchment

The aim of this study was to assess the runoff amount from a catchment characterized by diverse land uses by using the Soil Conservation Service Curve Number(SCS-CN) method based on Curve Number(CN) defined for dominant homogeneous elementary sub-regions.The calculations employed the SCS-CN method,involving the division of the catchment in two homogeneous parts and determining the runoff amount.The obtained results were compared with the results provided by three other CN determination methods,i.e.the Hawkins function,the kinetics equation,and a complementary error function peak.The catchment is located in a mountain dominated by forest land cover.Empirical CN-Precipitation(CN_(emp)-P) data pairs were analyzed using the mentioned methods,and the highest quality score was achieved from model 1.The results suggest that dividing a catchment into two homogeneous areas and determining their separate CN parameters,used later on to calculate the runoff by means of the presented approach,could be an alternative to the standard methods.The described method is relatively easy,and as it does not require an adoption of numerous parameters,and it can be employed for designing hydraulic facilities.

Theoretical and Experimental Study of a Double Air-Pass Solar Thermal Collector with an Insulating Rod of Millet

In this article, we present the study of a double-pass air insulated by crushed millet stem mixed with gum arabic. The study is carried out based on mathematical models obtained by writing energy conservation laws in the various components of the system, which made it possible to determine the evolution of the air temperature as a function of the length of the absorber and to make a comparison with the experimental results. After comparing the results obtained with those found in the literature, the influence of some physical and geometrical parameters on the performance of the solar thermal collector is presented.

Qualitative Assessment of Table Salt Production Techniques in Southern Benin Republic, and Related Mangrove Destruction and Health Issues

This research was conducted in the framework of the feasibility study related to FOCUSED-Benin project, the 5th work package of the YES-PV NIG BEN project financed by the German Government through its Ministry of Research and High Education (BMBF). The FOCUSED Benin project’s major objective is to protect the environment through the utilization of solar energy for drying agricultural products and table salt harvesting. Salt is important in human daily life. It is used for conservation of food, softening water, industrial processes, road de-icing, food seasoning, etc. Seawater evaporation, salt mining, and salt brine are the major sources of salt production worldwide. However, in West Africa, particularly in Benin Republic, table salt is produced using methods that negatively impact the ecology of the mangrove. This study aimed at investigating the current status of salt production in Benin Republic, its impact on the mangrove and its related health issues. Field visits, meeting with associations of women salt producers in the coastal region of the country, allowed to quantify the number of women associations dealing with salt production, their difficulties, and the impacts on the mangrove. Salt is a seasonal activity and is produced from January to May. One kilogram salt production, along with health issues reported by salt producers, requires approximately 1 kg of firewood obtained by cutting down mangrove. Salt price varies from 250CFA (€0.38) to 400FCFA (€0.61) per kg depending on the season. The women salt producers are not aware of the ecological consequences of mangrove destruction. Sources of firewood are becoming increasingly scarce and prices prohibitive. Sensitization is not efficient. An alternative method of harvesting salt by solar drying and new ideas for implementing this activity in a participatory approach was discussed with the different associations of salt producers.

Constraints, and Implications of Organic Farming in Bananas and Plantains Production Sustainability in Benin

Bananas and plantains production is an important income source for millions of small farmers. The increased demand for bananas and plantains on national and international market would justify its value chain development. However, its value chain faces several constraints, of which production and marketing turn out to be the most important. This study aimed at determining and analyzing the constraints related to Bananas and Plantains value chain and showing the gaps between agroecological and agricultural practices used by farmers in southern Benin. Characterization was carried out on the seed production systems, agricultural practices, bananas and plantains production, fruit availability and commercialization constraints with farmers using individual and focus groups surveys. Bananas and plantains seedlings production and acquisition varied according to production areas. Their seedlings self-production was widespread in production areas and 26 cultivars have been identified as major. The availability of these cultivars varied across time and production areas. There were significant negative effects of agricultural practices on major banana pest’s presence. Bananas and plantains production was limited by 12 factors, from which banana plants fall related to the wind, lack of financial support to irrigate banana fields, climate changes, no availability of cultivable lands and low rainfall are revealed to be the most important. Regarding commercialization constraints, low sale prices and difficult access to markets were the most important. Better knowledge of bananas and plantains production systems would help to develop sustainable organic farming strategies to reduce the constraints identified.

Z型禀议决策的潜在困境及突破策略研究

Z型禀议决策是Z型企业集体决策制度的核心,也是Z理论的重要组成部分。本文从剖析Z型禀议决策产生的社会历史背景和得以存续的前提假设入手,借助外部性理论,对其潜在的,诸如决策集体问责制阙如、集体决策能力不稳定、反集体利益维护趋势等困境作出了较为详细的剖析。随后又从完善多维度决策问责制度、加强周期性集体决策训练与打造高成本信任契约网络等三个方面分别提出了应对之策,从而为Z型禀议决策理论研究的完善提供了一得之见。

Evaluation of Solar Potential at Niamey: Study Data of Insolation from 2015 and 2016

Solar energy is a very abundant renewable energy source during the day. The solar energy received in a given point of the Earth is function of the time, the season and the latitude of the point. It has been proven that the solar energy received in one day by our planet is thirty times higher than the annual global energy consumption. Africa is one of the sunniest continents of the world. Nowadays, solar energy is attracting particular attention in the implementation of the energy policies. This renewable source is a key solution to world energy problems, especially in the context of global warming. Niger is identified as among the sunniest zones of the World. Knowledge of solar potential is one of the crucial parameters to master for energy applications. In this study, continuous measurements (at intervals of 5 minutes over 24 hours) of solar radiation have been carried out on the site of the National Center of Solar Energy of Niamey. These measurements were taken using the pyranometers, allowed us to collect the values of the daily global sunshine on a horizontal plane and on an inclined plane of the years 2015 and 2016. The treatment and the exploitation of these data allowed us to determine the daily and monthly duration of sunshine, then the impact of the clouds and dust on the solar radiation, to evaluate the solar potential of the site and determine the variations of this solar potential as a function of time. The results showed that the solar potential was very favorable for many solar applications.