最低总成本模式下最佳货币资金持有量的确定

目的　研究最佳货币资金持有量 .方法通过对企业持有货币资金三种成本的分析 ,求得总成本最低的状况下企业应持有的最佳货币资金量 .结果与结论　在特定的前提下 ,利用最低总成本模式可直接确定企业应持有的货币资金量     

浅析CDMA山区及交通干线覆盖方案

文章结合不同的用户分布和山区丘陵地形的特点进行站址选择和设备选型的分析,通过系统仿真来比较高山站与平地站的覆盖范围,综合考虑覆盖目标、建设成本和投资收益对二者进行取舍。直放站和射频拉远(RRU)是山区交通干线优化时的主力军,着重分析直放站对施主基站低噪抬升的影响。     

Vorkalkulation chemischer Anlagen

The economic analysis of processes allows a market orientation and prioritization of development projects. First of all, a preliminary costing takes place by estimating the investment costs. Basis for calculation is a complete process flow diagram with mass and energy balances for a layout of the process steps, performed in the standard material AISI 316Ti. Costs of other materials can be calculated with factors from a table, that of the other sizes and capacities by degression exponents. The preliminary costing is exemplified. The investment is the basis for the subsequent calculation of production costs.     

数字化网络监控系统在焊接领域中的应用

数字化网络监控系统可以对数台电焊机发送的焊接信息进行数据管理、品质管理、维护管理、生产管理、成本管理等五方面的管理.可对焊接电流、焊接电压、焊接时间、气体及焊丝的消耗量等进行管理.为焊接管理人员提供品质管理数据、焊机维修保养依据、以及根据报表了解成本因素等.采用焊机数字化网络监控系统,打造网络化、集约化、智能化的焊接工厂,有利于提升焊接质量和效率,降低焊接成本.通过焊接网络监控系统,控制焊接热输入量,可获得最优化的、一致性好的焊接接头组织与性能;通过焊接网络监控系统为精益化焊接生产、节能降耗提供依据.     

二期工业用蒸汽冷凝水回收方案

冷凝水由于其热焓值高、含氧量低、水质好．因此对蒸汽凝结水的合理回收利用,不仅可以提高锅炉除氧器的起始温度、降低锅炉煤耗,而且可以减少除盐水的制水耗费。     

Studies on the response of ‘Tifblue’ and ‘Woodard’ rabbiteye blueberries to fertilizers

A field study was conducted to investigate the effects of three fertilizer placement methods and 11 fertilizer formulations on plant survival, economics of replanting, yield, and fruit size of two rabbiteye blueberry (Vaccinium ashei Reade) cultivars Tifblue and Woodard. Fertilizer rates were either mixed with the soil under plants (before planting), sidedressed, or half-rate was placed under plants with the other half sidedressed. Fertilizers at planting caused a total of 34% Woodard and 12% Tifblue plants to die as compared to 6% for Woodard and none for Tifblue when no fertilizer was applied. Fertilizer formulas 2-1-1 and 5-10-10 oxide ratios placed under Woodard plants caused 100% mortality whereas Tifblue fertilized with oxide ratios 2-2-2 and 5-10-10 under plants reached the maximum 50% mortality. Splitting fertilizer placement under the side of the plants resulted in less Woodard plant mortality (30%) than placing all the fertilizer under plants (54%). However, plant mortality for the side/under group was not different than sidedressing all fertilizer (23%). A planted hectare in this experiment consisted of 1852 Tifblue and 926 Woodard plants, providing one Woodard plant to pollinate two Tifblue plants. Based on the results obtained, the 5-10-10 fertilizer placed under plants would be expected to cause half the Tifblue (926 plants) and all the Woodard (926 plants) to be replanted. Plant costs alone was estimated to be $2315 with additional replanting costs of $93 for Tifblue and much higher for Woodard. Sidedressing 5-10-10 fertilizer eight weeks after planting would have prevented plant mortality. Placement of various fertilizers under Woodard or Tifblue plants resulted in a significant increase in plant mortality as compared to side placement of fertilizers. Yield loss due to plant mortality increased linearly with the N level of the fertilizers (ranging from 0 to 2) for both cultivars. Woodard fruit size was not affected by fertilizer placement but placing fertilizers under Tifblue plants produced smaller yields with larger fruit than sidedressed plants. Blueberry plants in a virgin acidic soil may experience no reduction in yield if fertilization is completely eliminated.     

Cost analysis of seawater desalination with reverse osmosis in Turkey

Economically usable water resources per capita are decreasing due to excessive population increase each year in Turkey. For this reason, new water resources should be found in the near future. The potential water resources are seawater or well water both of which need removal of salinity. The most promising treatment method for salinity is reverse osmosis. While reverse osmosis becomes widespread, the cost of the process will decrease. There is no detailed information about cost of seawater desalination in Turkey. In this study, a cost analysis of seawater desalination in Turkey was performed for reverse osmosis systems. The basic parameters of cost analysis such as capacity, recovery, membrane life, energy, chemical costs and flux were evaluated based on the effects on capital, operating and total production costs.     

Monitoring and analysis of the energy cost of an MBR

Certain regions in the south of Europe are suffering an acute lack of water. One way to solve this hydric deficit is to use membrane bioreactors (MBR) to reuse the treated wastewater in tasks where drinking water is not required, e.g. irrigation. The aim of this research was to monitor physical-chemical (COD, BOD, and TN) and microbiological (EF, TC, and FC) parameters, as well as the energy costs in a Kubota MBR pilot plant located in Southeast Spain for one year, as well as to check the feasibility of the MBR process. The system showed a high robustness providing a fairly constant effluent with a large reduction of the entry pollutants and thus providing a highly reliable operation. High TSS, COD, BOD, NH⁺₄ and TN removal efficiencies up to 97, 94, 95, 98 and 81% respectively where achieved. The removal of the different microbials was quite high, with values in the permeate below 10 colony forming units (CFUs) most of the time. Some problems like blackouts, high temperatures and cleaning processes altered the normal operation lowering the retention of the different compounds and microorganisms. Regarding the energy consumption, two fluxes, 19 and 25 LMH were tested. Assuming a price for the electric supply of 0.0806 €/kW, the prices of the treated water for the two fluxes were 0.49 and 0.39 €/m3 and the total consumptions were 6.06 and 4.88 kWh/m³ for 19 and 25 LMH respectively. Aeration comprised almost 50% of the total energy requirements.     

三用型水源热泵方案和常规风冷冷水机组加燃油热水锅炉方案的比较

以大连长兴岛高尔夫球场会所为例，根据全年空调负荷、采暖负荷和生活热水负荷，选择了三用型水源热泵方案和风冷冷水机组加燃油热水锅炉方案，并对这两个方案的初投资和运行费用进行了计算；经比较，三用型水源热泵的方案初投资少，运行费用低，是较节能的方案，在地下水源充足的地区应大力推广。     

议建筑施工企业成本管理

从工程全过程的动态管理角度论述了自合同形成、履行至结束过程中施工企业成本管理的方法和应注意的问题,阐述了成本管理应＂合理预测,静态控制,动态管理＂,以期提高企业的成本管理水平,获得更加良好的经济效益。