Food-related energy requirements

I have used data from input-output studies to determine the quantities of primary and electric energy consumed in the agricultural, processing, transportation, wholesale and retail trade, and household sectors for personal consumption of food. Before one draws conclusions from these results, it is important to note the assumptions and approximations used in this analysis. First, the economic input-output data published by the Department of Commerce are subject to a number of inaccuracies, including lack of complete coverage for an industry, restriction of data for proprietary reasons, and use of different time periods for different data. Second, aggregation can combine within the same sector industries whose energy intensities differ widely. For example, eating and drinking establishments probably consume more energy per dollar of sales (because of refrigerators, stoves, and freezers) than do department stores. However, both types of establishment are included in retail trade. Thus energy use for food-related retail trade may be underestimated because of aggregation. Third, the energy coefficients are subject to error. In particular, the coefficients for the agricultural and trade sectors are vulnerable because energy use within these sectors is not well documented. Finally, the scaling factor used to estimate food-related energy use for the 1960's is approximate, in that it neglects the possibility that these energy coefficients changed differently with time. Because of these limitations, which are described more fully by Herendeen (6), a number of important issues were not addressed here. such as relative energy requirements for fresh, frozen, and canned vegetables; and for soybeans as compared to beef. This analysis shows that the U.S. food cycle consumes a considerable amount of energy, about 12 percent of the total national energy budget. The residential sector, which accounts for 30 percent of the total, is the most energy-intensive sector in terms of energy consumed per dollar of food-related expenditure. This is because food-related expenditures in homes are primarily for fuel to operate kitchen appliances and automobiles. The electricity consumed in these activities constitutes 22 percent of the total amount used in the United States. More than half of the electricity is used in homes, and more than two-thirds in the trade and household sectors. Thus agriculture and processing consume little electricity relative to the total amount used. From past trends, it appears that the amount of energy used in food-related activities will continue to increase at a rate faster than the population, principally because of growing affluence, that is, the use of processed foods, purchase of meals away from home, and the use of kitchen appliances equipped with energy-intensive devices, such as refrigerators with automatic icemakers. However, fuel shortages, rapidly increasing fuel prices, the growing need to import oil, and a host of other problems related to our use of energy suggest that these past trends will not continue. Fortunately, there are many ways to reduce the amounts of energy used for food-related activities. In the home, for example, smaller refrigerators with thicker insulation would use less electricity than do present units. If closer attention were given to the use of ranges and ovens (for example, if oven doors were not opened so often) energy would be saved. Changes in eating habits could also result in energy savings. Greater reliance on vegetable and grain products, rather than meats, for protein would reduce fuel use. Similarly, a reduction in the amounts of heavily processcd foods consumed-TV dinners and frozen desserts-would save energy. Retailers could save energy by using closed freezers to store food and by reducing the amount of lighting they use. Processors could use heat recovery methods, more efficient processes, and less packaging. Shipping more food by train rather than by truck would also cut energy use. Farmers could reduce their fuel use by combining operations (for example, by harrowing, planting, and fertilizing in the same operation), by reducing tillage practices, by increasing thc use of diesel rather than gasoline engines, and by increasing labor inputs. A partial return to organic farming (that is, greater use of animal manure and crop rotation) would save energy because chemical fertilizers require large energy inputs for their production.     

Hydrogen: Its Future Role in the Nation's Energy Economy

In examining the potential role of hydrogen in the energy economy of the future, we take an optimistic view. All the technology required for implementation is feasible but a great deal of development and refinement is necessary. A pessimistic approach would obviously discourage further thinking about an important and perhaps the most reasonable alternative for the future. We have considered a limited number of alternative energy systems involving hydrogen and have shown that hydrogen could be a viable secondary source of energy derived from nuclear power; for the immediate future, hydrogen could be derived from coal. A hydrogen supply system could have greater flexibility and be competitive with a more conventional all-electric delivery system. Technological improvements could make hydrogen as an energy source an economic reality. The systems examined in this article show how hydrogen can serve as a general-purpose fuel for residential and automotive applications. Aside from being a source of heat and motive power, hydrogen could also supply the electrical needs of the household via fuel cells (19), turbines, or conventional "total energy systems." The total cost of energy to a residence supplied with hydrogen fuel depends on the ratio of the requirements for direct fuel use to the requirements for electrical use. A greater direct use of hydrogen as a fuel without conversion to electricity reduces the overall cost of energy supplied to the household because of the greater expense of electrical transmission and distribution. Hydrogen fuel is especially attractive for use in domestic residential applications where the bulk of the energy requirement is for thermal energy. Although a considerable amount of research is required before any hydrogen energy delivery system can be implemented, the necessary developments are within the capability of present-day technology and the system could be made attractive economically .Techniques for producing hydrogen from water by electrolysis, from coal, and directly from thermal energy could be found that are less expensive than those now available; inexpensive fuel cells could be developed, and high-temperature turbines could be used for the efficient conversion of hydrogen (and oxygen) to electricity. The use of hydrogen as an automotive fuel would be a key factor in the development of a hydrogen energy economy, and safe storage techniques for carrying sufficient quantities of hydrogen in automotive systems can certainly be developed. The use of hydrogen in automobiles would significantly reduce urban pollution because the dispersed fossil fuel emissions would be replaced by radioactive wastes generated at large central stations. The conversion of internal or external combustion engines for combustion of hydrogen fuel would probably have less economic impact on the automotive industry than the mass introduction of electric automobiles. However, this is a subject that requires more detailed study. All of the safety aspects of hydrogen utilization will have to be examined, especially the problems of safety in the domestic use and the long distance transport of hydrogen in pipelines at high pressures. It is our opinion that the various energy planning agencies should now begin to outline the mode of implementing hydrogen energy delivery systems in the energy economy. The initial transition to hydrogen energy derived from available fossil fuels such as coal should be considered together with the long range view of all the hydrogen being derived eventually from nuclear energy. By the year 1985 when petroleum imports may be in excess of the domestic supply, these plans could set the stage for the transition period from fossil to a predominantly nuclear energy economy able to supply abundant synthetic fuels such as hydrogen. Synthetic fuels will obviously be more expensive than fuels now derived from petroleum; however, there may be no other viable choice. Thus, it is essential that the analysis and technological feasibility of a hydrogen energy system be considered now. It is of vital importance to the nation to develop some general-purpose fuel that can be Produced from a variety of domestic energy sources and reduce our dependence on imported oil.     

国际投资法自由化与我国外资立法对策

国际投资法已呈现出前所未有的自由化趋势, 从而促使国际投资法律调整的结构框架和内容体系发生重要的变化, 也促使各国利用外资及发展经济的政策和立法做出重要的变化。各国, 尤其是发展中国家纷纷加快投资自由化的步伐, 但盲目追逐只会对自身经济发展带来负面影响。因此, 我国应正确对待国际投资法自由化的发展, 并顺应这一形势的发展。本文从我国国民经济发展和国际竞争力提高战略角度, 提出完善我国外资立法的一些对策     

Energy conservation

We can no longer afford to ignore the serious potential consequences of our lavish use of energy. Continuation of the present rate of increase, particularly with the trend to imported fuels, will lead in short order to a level of dependency on imports which is disturbing for both the national security and the balance of payments. The inevitable rise in the price of energy will presumably lead to some increases in the domestic energy supply. But our reserves, particularly in the preferred forms of petroleum, gas, and even low-sulfur coal, are finite. Thus, the energy problem must also be attacked from the standpoint of energy conservation. The forthcoming rise in fuel prices will, of course, make more attractive some forms of conservation which at present are economically marginal. Nevertheless, consumers, industry, and government will have to make difficult choices in the years ahead: between greater convenience and lower energy bills, between the high capital costs of energy conservation measures and the long-term dollar savings from increased energy efficiency, and between environmental protection and the availability of needed energy supplies. Existing capabilities and technology, on which short- and midterm improvements must be based, appear to offer substantial possibilities for reducing U.S. energy consumption within the next decade (11). Long-term solutions to the energy problem, however, will depend to a considerable extent on the continuing appearance of new technological capabilities for increased efficiency of energy utilization and increased integration of energy applications. The capacity for continuing technological advances is, of course, dependent in turn on a strong relevant scientific base. A word of caution is necessary. Recent experience has shown that technological advances alone will not solve the problem. The problem spans not only the traditional physical and engineering sciences but also those sciences which deal with human attitudes and actions, that is, the social sciences, and includes a more fundamental understanding of underlying economic principles. The challenge to all sectors of American science should be clear.     

Lowering the temperature of solid oxide fuel cells

Fuel cells are uniquely capable of overcoming combustion efficiency limitations (e.g., the Carnot cycle). However, the linking of fuel cells (an energy conversion device) and hydrogen (an energy carrier) has emphasized investment in proton-exchange membrane fuel cells as part of a larger hydrogen economy and thus relegated fuel cells to a future technology. In contrast, solid oxide fuel cells are capable of operating on conventional fuels (as well as hydrogen) today. The main issue for solid oxide fuel cells is high operating temperature (about 800°C) and the resulting materials and cost limitations and operating complexities (e.g., thermal cycling). Recent solid oxide fuel cells results have demonstrated extremely high power densities of about 2 watts per square centimeter at 650°C along with flexible fueling, thus enabling higher efficiency within the current fuel infrastructure. Newly developed, high-conductivity electrolytes and nanostructured electrode designs provide a path for further performance improvement at much lower temperatures, down to ~350°C, thus providing opportunity to transform the way we convert and store energy.     

Biofuels and food security

The major source of energy comes from fossil fuels.The current situation in the fi eld of fuel and energy is becoming more problematic as world population continues to grow because of the limitation of fossil fuels reserve and its pressure on environment.This review aims to fi nd economic,reliable,renewable and non-polluting energy sources to reduce high energy tariffs in Russian Federation.Biofuel is fuel derived directly from plants,or indirectly from agricultural,commercial,domestic,and/or industrial wastes.Other alternative energy sources including solar energy and electric power generation are also discussed.Over 100 Mt of biomass available for energy purposes is produced every year in Russian.One of the downsides of biomass energy is its potential threatens to food security and forage industries.An innovative approach proved that multicomponent fuel(80%diesel oil content for motor and 64%for in stove fuel)can remarkably reduce the costs.This paper proposed that the most promising energy model for future is based on direct solar energy conversion and transcontinental terawatt power transmission with the use of resonant wave-guide technology.     

Effects of federal residential energy conservation programs

We used a detailed engineering-economic simulation model of residential energy use to evaluate the effects of nine different residential energy-use "futures." These "futures" are described in terms of annual and cumulative energy use from 1977 through 2000 by fuel, end use, and in aggregate. Outputs from the model also include economic information on the costs to households of fuels, equipment, and thermal improvements to new and existing structures. The major outputs from these nine cases are shown in Tables 1 and 2 and Figs. 6 and 7.     

信阳市外商直接投资与经济增长的关系——基于VAR模型的实证分析

利用信阳市2000～2012年外商直接投资与地区生产总值的时间序列数据,建立VAR动态时间序列模型,分析信阳市外商直接投资与经济增长的长期均衡及动态关系.实证结果显示：信阳市外商直接投资与经济增长具有长期稳定的关系,增加外商直接投资能促进经济增长.基于实证分析,提出了充分利用本市的资源禀赋,开辟经济发展新途径;积极尝试招商引资新方式,扩大外商直接投资规模;优化外商直接投资结构,增强对经济的带动作用等政策建议.     

Methanol as a gasoline extender: a critique

The tests conducted with the three vehicles at different emission control levels suggest that, in the area of fuel economy and emissions, potential benefits with methanol blends are related to carburetion and are only significant in the case of the rich-operating cars built before emission control standards were imposed. Theoretical considerations related to methanol's leaning effect on carburetion support this conclusion. Potential advantages for methanol in these areas are therefore continuously diminishing as the older cars leave the roads. At present, these older cars use only about one-fourth of the totalc motor gasoline consumed and, before methanol could be used on a large scale, this fraction would be much smaller. The use of methanol in gasoline would almost certainly create severe product quality problems. Water contamination could lead to phase separation in the distribution system and possibly in the car tank as well, and this would require additional investment in fuel handling and blending equipment. Excess fuel volatility in hot weather may also have adverse effects on car performance if the methanol blends include typical concentrations of butanes and pentanes. Removal of these light hydrocarbon components would detract from methanol's role as a gasoline extender and if current fuel volatility specifications were maintained, its use could lead to a net loss in the total available energy for use in motor fuels. Car performance problems associated with excessively lean operation would also be expected in the case of a significant proportion of late-model cars which are adjusted to operate on lean fuel-air mixtures. If methanol does become available in large quantities, these factors suggest that it would be more practical to use it for purposes other than those related to the extending of motor gasoline, such as for gas turbines used for electric power generation. In this case, the "pure" methanol would act as a cleanburning fuel, having none of the potentially severe product quality problems associated with its use in motor gasoline, while the fuel oil or natural gas cLirrently burned in these tuLrbines CotLild be diverted to other ulses.     

Energy sources: a realistic outlook

Projections to the middle of the next century indicate that unabated historical global energy trends would lead to an annual global energy demand about four times present levels, primarily due to population and economic growth. But extensive global conservation and energy-efficient systems might reduce this value by half. The cumulative effect of the coming half century's use may strain the world's low-cost resources, particularly oil. The future fuel mix is further complicated by the environmental thrust to reduce the global use of carbon-based fuels. The interaction of the principal factors influencing future energy resource and technology options are projected.     

投资项目净现值法的改进与应用

在分析现行农业机械化投资项目经济分析中存在问题的基础上，探讨了确定型，风险型和不确定型投资项目基准收益率的取值问题，最后，结合实例给出了风险型和不确定型投资项目的净现值分析法。     

木质纤维素类生物质转化生物乙醇预处理B2B工艺的发展研究

在能源问题日益紧张的时局下,寻求可再生的清洁能源成为目前亟待解决的关键问题,而乙醇燃料无疑是化石类能源的最佳替代能源。生物质转化为生物乙醇（简称B2B）工艺无论是从可行性、清洁性抑或是经济性来看都具有可大规模工业化应用的前景。基于木质纤维素物质来源广、成本低等特点,这类原料制备生物乙醇的研究取得了很大的进展。详细综述了木质纤维素类生物质转化生物乙醇中的预处理工艺进展和发展方向,并对各种预处理工艺的优缺点进行了论述,此外,对于双螺杆挤出爆破工艺也进行了详细阐释。     

新时期农业经济管理的分析与研究

农业经济是我国重要的经济支柱,加强对农业经济的管理,对保证我国的国民经济利 益具有重要的作用。基于此,本文就主要研究新时期的农业经济管理,对开展农业经济管理的 意义进行讨论,并找出管理中存在的问题,然后提出一系列的优化措施和问题解决措施。     

长期施肥条件下稻田肥料的表观经济效益研究

[目的]研究水稻种植经济效益最高的施肥方式。[方法]以水稻长期定位试验数据为基础,采用Saleque等介绍的方法对各种施肥制度的表观经济收益以及收益率进行评价。[结果]2NPK、NPK以及NP处理所获得的收益明显高于其他处理(P0.05);从投资收益率来说,NP处理由肥料投资所获得的收益率最高,其次为NPK处理,2NPK处理投资收益率较低,仅为NPK处理50%左右。因此,从经济角度讲,现行的推荐施肥方式具有最好的经济回报。[结论]该研究可为生产上水稻施肥提供指导。     

人力资本对农业经济发展影响的实证研究

农业是国民经济的基础产业,农业经济发展与人力资本的投资密切相关。采用时间序列数据,以河南省为例,运用柯布一道格拉斯生产函数分析了人力资本水平对农业经济发展的影响。结果表明,人力资本投资中的教育投资对农业经济发展有着显著的推动作用。据此。提出了促进农村人力资本形成的几点建议。     

安徽省能源经济的可持续发展探析

近年来安徽省能源经济形势发生较大变化,能源的生产消费与经济发展相互联系更加紧密.在此通过对2000 ～ 2012年安徽省能源经济数据的对比分析,研究安徽省的能源生产消费量变化情况及相关年份安徽省能源强度、能源消费弹性系数等指标的变化趋势,探讨该省能源发展的现状问题及解决方式.结果表明,安徽省能源生产消费量及GDP在不断增长的同时,增幅有所浮动,能源消费结构不断优化,能源产业投资及经济效益在增长,能源利用效率也在提高;安徽省能源可持续发展中仍存在的问题主要表现在煤炭能源储备不足、能源耗费大、能源体制适应性不够等方面.基于此提出可能的解决方法及建议,以求在坚持可持续发展的原则下,通过创新能源的利用方式、节约能源降低消耗、调整产业结构、优化资源配置、改变经济的增长方式等途径,有效促进安徽省能源与经济的健康协调发展.     

对土地利用基本特性的新认识

建国以来，一切在计划经济的原则下，片面强调了土地作为资源——生产资料的一方面，而忽略了经济特性的一方面。随着市场经济的发展，必须强调土地的自然和经济的双重性。本文用动态的观点，从土地利用的各个方面论述了土地在利用过程中表现出来的主要特性，较为全面地继承和发展了土地利用特性的认识观，提出了：土地地理位置的固定性与相对位置的可变性的相对统一、土地利用的永续性与土地利用的可退化性的相对统一、土地物质投入产出报酬的递减性与科技投入产出报酬的递增性的相对统一以及土地利用适应市场价格变动的缓慢性等六个土地利用的基本特性。我们认为，这一观点将对我国土地利用管理理论和制度的发展产生积极作用。     

Socioeconomic impact of widespread adoption of precision farming and controlled traffic systems in Denmark

In this study we assess the economic profitability of implementing various precision farming (PF) technologies and controlled traffic farming (CTF) on 4 main crops in Denmark. The study provides insight into technological requirements, and identifies related costs and benefits to farmers and the Danish society as a whole. At the farm level, the findings from the study indicate that an implementation of CTF systems may have a significant impact on fuel savings due to a reduced overlap with auto guidance systems and easier movement with tractors and tools in the field. The PF site-specific weed management approach may facilitate large savings in the use of herbicides. At the national level, the results clearly show that the benefits to the Danish economy of adopting this new technology is positive with increased income to farmers and a reduction in fuel consumption and pesticides/herbicides use. The obtained results reflect the long term economic effect of implementing new production methods in Denmark where soil fertility increases over time due to reduced traffic increasing yields. Over all, the Danish GDP is estimated to increase by 34?million?? due to the implementation of PF and CTF on larger farms in Denmark. The results also clearly show that adoption of PF and CTF farming systems will benefit the environment. The agricultural sectors input of environmental harmful inputs are reduced in all scenarios presented in this paper. The adoption of PF and CTF systems should thus be of interest to politicians since it clearly facilitates aims of environmental policies currently under implementation by the Danish government.     

基于混沌模糊神经网络方法的短期负荷预测

文章通过研究我国科技投入与经济增长之间的依存关系,建立了相关的计量经济学模型,利用模型测算出我国科技投入对经济增长的拉动效应,并在此基础上提出相应的政策建议.     

江苏能源消耗的碳排放估算及趋势检验

在文献综述及现状分析的基础上,对江苏经济发展中的能源消耗碳排放量进行了估算,并对江苏省经济增长与碳排放量之间的关系进行了实证研究。研究结果表明:江苏省经济增长与能源消耗碳排放量之间的关系呈现弱"N"型变化趋势,说明随着江苏经济的快速增长,环境治理投资存在明显不足。需要进一步增加环境污染治理投资,制定长期的环境治理投入计划,重点控制大型污染源,利用新的技术与工艺提高环境治理效果,最大限度地减少能源消耗中的碳排放量,促进江苏经济增长与能源消耗碳排放量之间的关系向倒"U"型转化。