The Use of Hydrogen as a Fuel for Inland Waterway Units

Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.

（Dis）Economies of Scale in Business Software Systems Development and Enhancement Projects

In the software engineering literature, it is commonly believed that economies of scale do not occur in case of software Development and Enhancement Projects （D＆EP）. Their per-unit cost does not decrease but increase with the growth of such projects product size. Thus this is diseconomies of scale that occur in them. The significance of this phenomenon results from the fact that it is commonly considered to be one of the fundamental objective causes of their low effectiveness. This is of particular significance with regard to Business Software Systems （BSS） D＆EP characterized by exceptionally low effectiveness comparing to other software D＆EP. Thus the paper aims at answering the following two questions： （1） Do economies of scale really not occur in BSS D＆EP？ （2） If economies of scale may occur in BSS D＆EP, what factors are then promoting them？ These issues classify into economics problems of software engineering research and practice.

Modeling of a Demethanizer Tower Using Statistical Tools

Monitoring of industrial plant performance and detection on flaws is important to the successful operation on industrial production units. Malfunctioning equipment can greatly impact plant performance by reducing the efficiency and increasing the production cost. Phenomenological equations cannot properly describe industrial processes. Thus, it is necessary to develop new equations for model industrial operations. The purpose of this study is to develop an empirical model for industrial demethanizer tower which is malfunctioning due to an error in the design in one of its plates. A nonlinear statistical model was designed to predict the pressure variation in the column, and consequently, the flooding conditions. This model was validated using industrial data to predict the maximum loads in the column.

Linear Programs in Cost Accounting： A Linear Cost Model

This paper aims to find unit cost of a product for firms. It establishes a linear cost model to find unit cost. Linear goal programs assume a direct relationship between independent variable and dependent variable. Dependent variable of linear model is unit cost. Independent variables are cost accounting variables. They are supply cost, labor cost, and administration cost. This study assumes a direct relationship between supply-labor-administration costs and unit cost. Therefore, it establishes a linear cost model. The major research question of this study is to apply linear goal programming to cost accounting. The goal of this linear program is to find unit cost of product. This study uses quantitative method and human capital method. The main research result is linear costing model itself.

Learning by Doing Effect in North South Trade under the Global Value Chains： An Empirical Analysis of Various Industries in the U.S.

This paper studies the division of labor and economic development under global value chains in North South trade by mainly investigating the changes of production hours and cost per unit along with more and more output and increasing trade value in several industries in the U.S., because the U. S. is at the leading position in the division of labor by global value chains. The empirical evidence reveals that more international outsourcing, there will be more detailed division of labor, and the industry unit production time and production cost will show more declining trend year by year. This is consistent with that the global value chains and the outsourcing play more and more important roles in the international division of labor and economic growth in both developed and developing countries, and helps explain the integration of workforce across countries in the global value chains.

Kit of Self-Moving Units for Automatic Inspection of Marine Structures and Plants： Low Cost Unit for Inspection of Holds

All vessels and offshore units require regular inspections to prevent structural or functional damages. Periodical inspections are based on classification society＇s requirements and include both visual surveys and non-destructive test interventions, to look for structural damage, pitting, corrosion, thickness measurement, usually documented by measurements or images. Different approaches of inspection can be proposed for underwater and for dry areas, using unmanned vehicles or service robots able to improve traditional inspection methods. Several excellent proposals are today available： nevertheless, reasons of costs, operation complexity and impossibility to cover all types of inspection with a unique autonomous unit limit and conditions the applicability of automatic inspection systems. The paper is the first of a series describing the main results of a wide research activity carried out at DREAMS Lab （Laboratory of Drives and Experimental Automation for Marine Systems） of the University of Genoa. The studies are oriented to the realization of a kit of low cost and unsophisticated self-moving units, devoted to support some recursive inspections in dry areas of ships and on offshore plants as bulkheads, holds, double bottoms and ducts. The paper describes the design and prototyping of a pneumatronic unit oriented to inspection and maintenance of ship holds. Conceived to realize a portable and user-friendly tool which could take part of an ＂inspection kit＂ for the use of inspectors, able to simplify and speed up the inspection visits with and automatic generation of survey reports.

Single-Seed Casting Large-Size Monocrystalline Silicon for High-Efflciency and Low-Cost Solar Cells

To grow high-quality and large-size monocrystalline silicon at low cost, we proposed a single-seed casting technique. To realize this technique, two challenges—polycrystalline nucleation on the crucible wall and dislocation multiplication inside the crystal—needed to be addressed. Numerical analysis was used to develop solutions for these challenges. Based on an optimized furnace structure and operating conditions from numerical analysis, experiments were performed to grow monocrystalline silicon using the single-seed casting technique. The results revealed that this technique is highly superior to the popular high-performance multicrystalline and multiseed casting mono-like techniques.

Development of an Anaerobic Digestion Unit for Biogas Production from Cow Dung Substrate

An anaerobic digestion unit for producing biogas from cow dung in the rural communities was designed, fabricated and tested for performance, durability and throughput. The major components of the digester included the substrate holding tank, tank cover, agitator, debris collector, inlet and outlet pipes, gas reception tank, hose and heat source. The digester is a vertical cylindrical tank with an inlet pipe for the introduction of substrate and an outlet pipe to collect the digested substrate. An agitator is incorporated inside the digester to break scum on the substrate and create uniform temperature profile in the digester while a pressure gauge was fitted to the gas outlet valve to measure the gas pressure in the tank. The agitator shaft is extended outside to be driven by an electric motor through belt and pulley system. The criteria considered in the design of the digester included air tightness of the system, mesophilic and thermophilic temperature, nature and type of substrate used, substrate retention period, number of crank turns per minute and volumetric capacity of the digestion tank. Other considerations included the desire to make the digestion tank and gas reception tank of galvanized steel to ensure good quality of the product and the need for a strong structural support to ensure structural stability of the system. After construction and assembly, the biogas digestion unit was tested with 40 kg of cow dung diluted with 80 kg of water and subjected to a retention period to make a substrate （slurry） of 10 % total solid （TS）. Daily gas yield was determined; gas pressure in the tank was measured by the pressure gauge, while the ambient temperature was taken at five hours interval. Results showed that a cumulative gas yield of 0.415 litres after 22 d retention period at average substrate temperature and pH of 29 ℃ and 6.2, respectively. The digester has a substrate holding capacity of 330.8 litres and a production cost of $375 with all the construction materials being available locally.

Cost of Production at Business Unit in Aquaculture Industry： Study at Aquafarm Nusantara Company

Types of industry are manifold, patterns used in the determination of the cost of production can also vary. Elements of the cost of production are raw materials, direct labor, and factory overhead. Value of raw materials used in aquaculture industry in particular needs to calculate the cost of feed consumed by fish, thus greatly affect the price of fish feed cost of production. The calculation of the value of raw materials in fish production cost element to consider is the calculation of the value of raw material components, namely, （1） biomass of harvestable fish as the basic multiplication cost of production per kilogram or per fish harvested fish; （2） the ratio of fish feed intake by the amount of fish produced or often called the Feed Conversion Ratio （FCR）; and （3） the average purchase price of feed on fish harvest period is used as the basis for calculating the cost of production as well. This research is applied research that uses data archive aquaculture companies. The results in the observed period, the value FCR is 0.80, which means to fish have been consumed as much as 0.80 kg of fish feed. Biomass of fish that are harvested at 47,399.95 kg or 1,869,647 individuals. The average purchase price of fish feed on the observation period amounted to IDR 4,855.79. So the price of raw materials contained in harvested fish in the observation period calculates the value of multiplying all the components of raw materials （i.e., IDR 184,131,362.57）. Method of calculating the cost of production companies is process method and charging method used is the full costing method.

季节性蓄热太阳能—土壤源热泵系统热经济学分析

本文建立了基于实际示范工程的季节性蓄热太阳能—土壤源热泵系统的热经济学模型,动态模拟了系统的运行。计算结果表明:系统的年度化成本为10 062元,单位能量成本为65.89元/GJ,单位成本为678.72元/GJ;全年供热供冷总的能效率为55.71%、效率为16.71%、能效比为5.68、效比为0.55,可知该系统经济且节能。另外,能效比和效比相对能效率和效率更具有实际操作意义;分析法能得出更加科学合理的结果,热经济学分析可作为系统优化和多方案经济性比较的依据。