Residues of organochlorine pesticides in surface soils from college school yards in Beijing, China

Organochlorine pesticides (OCPs) have been a major environmental issue, attracting much scientific concern because of their nature of toxicity, persistence, and endocrine disrupting effects. Soil samples were collected from ten college school yards in Beijing in 2006 and analyzed to determine fifteen OCPs. Dichlorodiphenyltrichloroethanes (DDTs) were found to be the main pollutants, accounting for 93.70% of total OCPs, followed by hexachlorohexanes (HCHs) (2.25%) and hexachlorobenzene (HCB) (1.82%). Content...

An automated water dispensing system for controlling fires in coal yards

In spite of recent moves to wean the world of fossil fuels,coal remains the main source of power in many countries.Coal yards are prone to spontaneous ignition,a problem faced in every country that stores or transports coal.Depending on the environment-temperature,ventilation,and the rank of the coal-heating and self-ignition can be a longer or shorter process,but the possibility can never be entirely dismissed.A plethora of studies have modelled this oxidation behavior and proposed countermeasures.Most often,human intervention is necessary,which is both slow and dangerous for the frefghters involved.In this study,we propose to build a complete frefghting solution which is mounted on a number of towers sufcient to cover the area of an open coal yard,complete with redundancy.Each tower includes an inexpensive infrared detector,a water dispenser and a controller programmed to identify areas of elevated temperature,and actuate the dispenser.The heat direction algorithm calculates the parameters to position the water dispenser so that it covers the area.A prototype has been built from inexpensive components to demonstrate the efectiveness at detecting and extinguishing arising fres,and a solution has been costed for the coal yard in the case study.This work has been conducted in collaboration with the managers of the coal yard of a power plant.

Statistical Model of Path Loss for Railway 5G Marshalling Yard Scenario

The railway mobile communication system is undergoing a smooth transition from the Global System for Mobile Communications-Railway(GSM-R)to the Railway 5G.In this paper,an empirical path loss model based on a large amount of measured data is established to predict the path loss in the Railway 5G marshalling yard scenario.According to the different characteristics of base station directional antennas,the antenna gain is verified.Then we propose the position of the breakpoint in the antenna propagation area,and based on the breakpoint segmentation,a large-scale statistical model for marshalling yards is established.

明清至民国时期广东大亚湾区盐业社会--基于文献与田野调查的研究

大亚湾是广东众多海湾之一,位于今广东省惠州市惠东县、惠阳区和深圳市宝安区之间,“东靠红海湾,西邻大鹏湾”,“该湾由三面山岭环抱,北枕铁炉嶂山脉,东倚平海半岛,西依大鹏半岛”①。据《中国海域地名志》,大亚湾位于N22°30′~22°50′,E114°29′~114°49′,湾内岛屿众多,岸线曲折,大湾套小湾,有百岛湾之称。

Assessment of Radiological Contamination of Soils Due to Shipbreaking Using HPGe Digital Gamma-Ray Spectrometry System

A systematic study of the distribution of the Naturally Occurring Radioactive Materials as well as the anthropogenic radionuclide in the working environment of the Shipbreaking yards of Sitakunda, Chittagong, Bangladesh, has been carried out with an objective of establishing reliable base line data on the radiation level and hence to measure the radiation dose expose to the workers and to the inhabitants of the studied area. Fifteen Soil samples have been col-lected from five different Shipbreaking yards. Three sampling spots in each yard have been selected for having repre-sentative samples for the assessment of radioactivity releasing from 226Ra (238U), 232Th and their daughters and 40K us-ing the Digital Gamma-ray Spectrometry system coupled with a High Purity Germanium (HPGe;Canberra, 40% rela-tive efficiency, 1.8 keV resolution at 1332 keV of 60Co) detector and PC based Multichannel Analyzer (MCA, upto 16k channel). The software Genie 2000 (Canberra) and Hypermet PC have been used for data acquisition and gamma peak analysis, respectively. Each of fifteen soils (~200g) and two standards (IAEA-Soil-6 and 800Bq liquid 226Ra sprayed in Al2O3) were counted in cylindrical plastic pot using gamma spectrometry system for 20000 sec for the determination of activity concentrations of the radionuclides. The samples and standards were kept in air tied condition at least for 4 weeks before gamma counting to attain the radioactive equilibrium between daughters and parents of 226Ra (238U) and 232Th decay series. The Al2O3 based 226Ra standard was used for the construction of efficiency curve covering the wide gamma energy range. The IAEA-Soil-6 was used for quality control (QC) of the analysis. The homogeneity test and density corrections of Al2O3 based 226Ra standard were performed and implemented for the analysis. The results of ac-tivity concentrations have been used to assess the radium equivalent activities (Raeq) and the representative level index (Iγr) values in the experimental soil samples. The results have been compared with other global radioactivity measure-ments and evaluations.

Ship Maintenance and Repair Services in the Tema Drydock and Shipbuilding Yard in Ghana: Some Challenges, Opportunities and Prospects

This article explored existing policies (if any) and current management structure which govern operations within the yard, examine some major challenges facing the ship maintenance and repair services in Tema Drydock and Shipbuilding Yard, Ghana, identified few drivers that impact positively on the ship repair market with particular reference to the Tema Shipyard. It concludes by proposing sustainable management and maintenance strategies for improved repair services of the yard as well as analyzing the findings obtained in the data presentation and discussion sections during the research project. The main finding is that the PSC Tema Shipyard’s ship maintenance and repair services are really overwhelmed with major challenges, representing 55% after summing up four (4) out of the seven (7) captured in the study and are threatening its sustainability, if not properly researched and addressed once and for all. As already stated, carefully analysed conclusions were drawn to effectively address these challenges, followed by suggestions for future research to forestall its cascading effects on the Ghanaian economy as a whole.

A method for optimization of time intervals between rolling cuts on sorting humps

Sorting humps are the main technical means providing the breaking- and making-up of freight trains. Automation of sorting process by implementing microprocessor control systems is the main direction ofincreasing hump yard capacity, enhancement of safety in trains breaking-up, improvement of working conditions on hump yards. However, for wider introduction of such systems at the humps, it is necessary to reduce their cost. One of the main tasks of hump control systems is the determination of the optimal cars exit speeds from the retarders. Its solution is significantly complicated because of the uncertainty of cars rolling resistance coefficient, wind velocity and direction, retarder control errors. The paper is aimed at solving the problem of searching for such cars exit speeds from the retarders that provide the longest time intervals between them at the switches. Implementation of this method will make it possible to improve the quality of sorting process as a whole by improving the software of microprocessor control systems for automatic humping, rather than by increasing their technical facilities, which as a result will reduce the cost of their construction and operation. The research results, when solving the problem of searching for cars exit speeds from the retarders, allow us to move from searching for the maximum of a nonlinear non-smooth function of two variables to solution of an equation with one variable, which significantlyaccelerates and simplifies the solution to the problem.

STUDY ON THE LOG PRODUCTION LINE IN LOG YARD

The article deals with the prduction lines in log yard by investigating the utilizationof machines in forest areas,presents the methods and rules of differentiating the log productionlines and also summarizes the formation and development of three kinds of log production lines innortbeast forest areas of China.It gives different combination types of log production lines andtheir applications, so it is significant for us to evaluate and standardize the log Production lines.

Length optimization of straight line connecting turnout on main line in high-speed railway station yard

Taking the development of high-speed railway in China as background, and referring to the dynamic theory and wheel-rail contact mode, dynamic analysis model was established, considering the setting position of straight lines and running conditions of train in high-speed railway station yard. Using the established model, and choosing vehicle lateral acceleration and wheel suspension as the evaluation indexes, dynamic characteristic of vehicle traveling in turnout and adjacent area on main line was analyzed, and effects on travelling safety and stability of train aroused by length variation of straight lines were calculated based on analyzing the damping rules of vibration. The results show that, a certain length of straight lines can alleviate the vibration aroused in turnout and curve(turnout), length of straight lines connecting turnouts in different sections on main line was proposed to meet the demand of traveling stability, and shortening or cancelation of straight line for the scale limitation of station yard has less influence on operation safety of train.

Evaluation of Wheat Varietal Performance under Different Nitrogen Sources

Nitrogen fertilization plays a very important role for crop productivity. New developed wheat varieties need proper fertilization for improved crop productivity. The present study was carried out to quantify, the effects of nitrogen derived from urea and FYM on the four newly developed wheat varieties i.e. Siran-2009, Ata Habib, Janbaz-2009 and Pirsabak-2008 for yield improvement, quality and soil fertility status. The N treatments were control, 100% of the recommended nitrogen from urea as well as FYM, and 50% from each source. The experiment was carried out at New Developmental Farm, Khyber Pakhtunkhwa Agricultural University Peshawar Pakistan, during Rabi 2011-2012. Results of the data showed that Janbaz-2009 was more responsive to biological yield (11,011 kg·ha-1), grain yield (4339 kg·ha-1), and nitrogen use efficiency (14.8%), whereas Siran-2010 performed better for grain N contents (2.31%). Plots having both urea and FYM had improved biological yield (11,958 kg·ha-1), and grain yield (4901 kg·ha-1). Urea application had improved straw N contents (0.92%) in addition to Mix application of urea and FYM (0.93%). Mix application of both sources and sole FYM had higher grains N content (2.25%), whereas control plots in addition to mix application had improved nitrogen use efficiency (14.8%). Siran-2010 and Janbaz-2009 performed better in FYM and mix FYM and urea plots for most of the parameters. It was concluded from the experiment that Janbaz-2009 had improved yield and yield components, whereas Siran-2010 had improved the grain N content. Similarly, Mix application of FYM and urea had improved crop productivity, soil fertility and grains as well as straw N content. Thus wheat varieties Janbaz-2009 sown in mix FYM and urea is recommended for general cultivation in agro-climatic condition of Peshawar.

Container Terminal Land-Utilisation Efficiency in Ghana

Land-use efficiency is essential in ports, in particular those that are constrained for space and experiencing congestion. In such situations, ports have been noted to invest in off-dock container yards. This study analysed land use efficiency of four off-dock yards located near the Port of Tema, Ghana’s largest seaport responsible for 85 percent of its trade. The study found that the terminals utilised 0.13 to 0.52 hectares of land, largely influenced by the dwell time and stacking height of containers. It was recommended that regulatory agencies need to coordinate better to reduce the time spent on cargo inspection and validation. In addition, terminals may need to incentivise customers to clear their import containers within shorter periods.

Assessment cultivated period and farm yard manure addition on some soil properties, nutrient content and wheat yield under sprinkler irrigation system

This study examined changes in some soil hydrophysical, chemical properties and wheat yield (grain;straw yield, N, P, K, Protein and carbohydrates contents) as trends under two cultivated period 10 and 25 year and Farm Yard manure (FYM) addition under sprinkler irrigation system on a newly reclaimed soils, Nubaria, Beheira Governorate, Egypt. Obtained results noticed that cultivation period has more pronounced effect than FYM addition on soil water content at field capacity, wilting point and available water with increase percent 15.1%, 9.3%;19.0% and 25.7%, 19.5% and 30.0% for FYM and cultivation period comparing with control one. Hydraulic conductivity values were strongly affected by cultivation period and FYM addition and significantly decreased values by about 18.9% and 12.1% in same sequences. Wheat straw content from protein had a superior effect under 25 than 10 years cultivated periods with values 61.9 and 6.7 comparing with control, respectively as affected by FYM addition, while FYM alone improved protein content in straw by about 31.9% comparing with untreated one. Slightly increase in straw protein content was attained relative to the increase of cultivated period by about 7.8%. Nutrients content in grain is more than FYM, where the increase percentage were 5.2%, 13.5%;3.8% and 26.5, 21.3;22.6 comparing cultivated periods 25 with 10 years and FYM addition with control, respectively. FYM individually under two studied cultivated periods is more effective under 10 years (28.0%, 25.2%;15.1%) than the 2nd one (25.1%, 25.2%;15.1%) comparing with untreated FYM plots. While N, P and K content in wheat straw had unclear trend and the increase were 6.8, 23.23;56.5% and 62.9, 6.0;29.8 as a result of FYM addition under 10 and 25 years cultivated periods, respectively. The highest values of protein and carbohydrates content in wheat grains as affected by studied factors were 12.86% and 67.43%) were obtained under cultivated period 25 years after FYM addition. Cultivated periods had a highly significant effect on the field water use efficiency values of grain more than the effect of FYM. The highest values of grain and straw yield were recorded at 10 years cultivated periods + treated FYM (2966.8 kg/fed) and 25 years cultivated periods treated with FYM (3835.6 kg/fed). Cultivated periods increased grain and straw yield of wheat crop by about 57.6% and 8.3%. Whereas, FYM increased grain and straw yield by about 39.8% and 58.8% relative to the control, respectively.

Application of 3D CAD Modeling in Designing 330 kV Outdoor Switch Yard Layout

The Development of 3D CAD technology presents a new effective tool in designing outdoor switch yard for power plant. A new layout pattern of 330 kV switch yard (SWYD) of aligned type was studied with this method. Some issues about computerized 3D modes applied in SWYD design are also discussed in this paper.

Collaborative Optimization of Berth Allocation and Yard Storage in Container Terminals

Considering the interaction between the berth and the yard,this paper studies the collaborative optimization problem of berth allocation and yard storage from the point of the ships over a certain planning period.This collaborative optimization problem is formulated as the integer programming,which aims at minimizing the total truck travel distance.And decision variables are the berthing positions for visiting ships and the storage positions for export containers.Meanwhile,this paper demonstrates the complexity of the problem in theory.And the hybrid tabu genetic algorithm is designed to solve the problem to obtain the optimal berth allocation position and export container storage position.For this algorithm,the rule is applied to generate the initial feasible solutions,and the crossover and mutation operation are simultaneously applied to optimize the initial solutions.Finally,this paper discusses two different scenes:the same berth scene and the same ship scene.The influence of two different scenes on truck travel distance is analyzed by different numerical examples.Numerical examples’results show that the collaborative optimization of berth allocation and yard storage can effectively shorten the truck travel distance and improve the efficiency of terminal operation,which provides the decision support for terminal operators.

The Conception of Modern Chinese Space in “Courtyard·Yard”:Analysis on Two Plans for the Reconstruction and Expansion of Zhang Kaiji in His Later Years

By introducing two famous works of Mr.Zhang Kaiji in his later years,the reconstruction plan of Beijing Planetarium and the Museum of Chinese Revolution and the Museum of Chinese History,the paper analyzes the "courtyard·yard" space he once imagined in the modern city and large public buildings,and expounds the value and significance of his conception.The author believes that the expansion and transformation of important works should be based on historical research and centered on the spirit of space,and the intangible space outside of tangible entities should be carefully treated,so as to better complete the transmission of modern Chinese space experience.

Site Selection of Waste Slag Yard and Design of Protective Measures in Water Supply Project of Drawing from the Songhua River in Central Cities of Jilin

Water supply project of drawing from the Songhua River in central cities of Jilin is taken as research object.On the basis of analyzing project characteristics and natural conditions of the project area,site selection of waste slag yard of water diversion project and design of water and soil conservation measures are discussed.Rationality of site selection of waste slag yard and pertinence of prevention and control measures of water and soil loss in waste slag yard are analyzed,and comprehensive utilization of waste slag in large-scale production and construction projects is explored.

Opportunities,Challenges and Countermeasures proposed for the new retail industry in The COVID-19

It has been four years since the concept of“new retail”was proposed,and the layout of“new retail”of several major domestic enterprises has been intensified,which has a“unique landscape”compared to the foreign retail landscape.The trend,however,the sudden outbreak and continued spread of the COVID-19 has dealt a serious blow to the global economic development,from the domestic point of view,the epidemic caused by the decline in GDP,leading to a negative year-on-year growth in the total retail sales of consumer goods,the new retail industry is still in the development stage suffered a blow.On the other hand,however,the sinking of the new retail market driven by the consumer economy,the surge of private domain traffic on platforms and the rise of the“house economy”prompted the new retail industry to create new development opportunities during the epidemic,clarifying the development of the new retail industry in the post-epidemic era and pointing out the direction.

Simulation and Optimization Techniques for Sawmill Yard Operations——A Literature Review

Increasing costs and competitive business strategies are pushing sawmill enterprises to make an effort for optimization of their process management. Organizational decisions mainly concentrate on performance and reduction of operational costs in order to maintain profit margins. Although many efforts have been made, effective utilization of resources, optimal planning and maximum productivity in sawmill are still challenging to sawmill industries. Many researchers proposed the simulation models in combination with optimization techniques to address problems of integrated logistics optimization. The combination of simulation and optimization technique identifies the optimal strategy by simulating all complex behaviours of the system under consideration including objectives and constraints. During the past decade, an enormous number of studies were conducted to simulate operational inefficiencies in order to find optimal solutions. This paper gives a review on recent developments and challenges associated with simulation and optimization techniques. It was believed that the review would provide a perfect ground to the authors in pursuing further work in optimizing sawmill yard operations.

Simulation Model Using Meta Heuristic Algorithms for Achieving Optimal Arrangement of Storage Bins in a Sawmill Yard

Bin planning (arrangements) is a key factor in the timber industry. Improper planning of the storage bins may lead to inefficient transportation of resources, which threaten the overall efficiency and thereby limit the profit margins of sawmills. To address this challenge, a simulation model has been developed. However, as numerous alternatives are available for arranging bins, simulating all possibilities will take an enormous amount of time and it is computationally infeasible. A discrete-event simulation model incorporating meta-heuristic algorithms has therefore been investigated in this study. Preliminary investigations indicate that the results achieved by GA based simulation model are promising and better than the other meta-heuristic algorithm. Further, a sensitivity analysis has been done on the GA based optimal arrangement which contributes to gaining insights and knowledge about the real system that ultimately leads to improved and enhanced efficiency in sawmill yards. It is expected that the results achieved in the work will support timber industries in making optimal decisions with respect to arrangement of storage bins in a sawmill yard.