Current Trends In Production Research Articles

Comparison of Continuous Strip Casting with Conventional Technology

Increased competition and the need to decrease steel product prices has combined with other factors such as growing salaries, increasing cost for electricity and raw materials to apply pressure to both mini and integrated mills. To compete in the future market and to maintain market share, both mills will need to use new efficient technologies capable of supplying steel strip products of high quality at low cost. Large investments in the development of strip casting process by the main world steel produces and plantmakers have already occurred due to its huge potential to substantially reduce the investment cost of steel strip production. Open literature on the continuous casting has been reviewed, with emphasis on strip casting of steel as new generation of continuous casting technology and has covered the following topics: current trends in production of steel strip; advantages of strip produced direct from the melt; strip casting process; strip quality; commercial strip casters and expenditure on research and development of the strip casting process.

Nutritional control of amino acid supply to the mammary gland during lactation in the pig.

The paucity of data relating to lactation physiology of the sow has frustrated researchers in estimating nutrient needs for production and mammary maintenance functions. The nutritional control of amino acid supply for milk synthesis is influenced by factors that have yet to be measured, such as blood flow and amino acid contribution from the body protein pool. The interaction or role of hormones such as insulin, glucagon or prolactin in amino acid dynamics and inter-organ exchange during lactation in the sow, are not well understood. The discrepancy existing between milk and mammary amino acid uptake profiles relative to lysine may be indicative of mammary metabolism and possibly maintenance requirements for specific amino acids. Hence, amino acid metabolism in the mammary gland, regardless of arterial blood substrate supply, may play an important role in a factorial approach to determining requirements. Mammary amino acid uptake ratios rather than milk amino acid ratios should provide a better tool to estimate amino acid requirements relative to lysine. Although lysine has typically been limiting in maize-soyabean-meal-based diets fed to lactating sows, current production trends are bringing a new dimension to the formulation of lactating-sow diets. Other amino acids may become limiting if dietary crystalline lysine is added without concern for the whole essential amino acid profile. Formulations based on an ideal amino acid profile for the lactating sow will, therefore, become critical.

Technology for conversion of lignocellulosic biomass to ethanol

Current trends in production of fuel ethanol from lignocellulosic materials are reviewed. Particular emphasis has been laid on the microbial synthesis of cellulases, enzymatic hydrolysis, pretreatment of lignocellulosics, and their simultaneous saccharification and fermentation to ethyl alcohol. Some pilot-scale plants producing alcohol from biomass are also presented.

Energy and American society: a reference handbook

Review: Energy and American Society: A Reference Handbook By E. Willard Miller and Ruby M. Miller Reviewed by Haipeng Li Oberlin College Miller, E. Willard and Ruby M. Miller. ENERGY AND AMERICAN SOCIETY: A REFERENCE HANDBOOK (Contemporary World Issues Series) Santa Barbara, CA: ABC-CLIO, Inc. 1993. 418 pp. US $39.50 hardcover ISBN: 0-87436- 689-5. Recycled, acid-free paper. No one can deny the importance energy has played in shaping modern American culture and America's position in the industrial world. Yet only in recent years has it become evident that the nation's energy resources are not inexhaustible and must be used with greater efficiency. As part of ABC-CLIO's award-winning Contemporary World Issues series, ENERGY AND AMERICAN SOCIETY discusses energy issues in American society. Authors Miller and Miller have compiled a listing of various energy resources, such as petroleum and bituminous coal, and described each in detail in regards to their major production areas and current production trends. The book also contains current information on statistical data and hard- to-obtain information on organizations. This is helpful to the lay person and the professional alike. Typically, the authors provide general as well as detailed information and data on specific resources. For example, one might be surprised to find out that in 1990, United States energy production was 67,600 trillion Btu, while energy consumption was 81,500 Btu. The authors also supply a list of energy laws and regulations, including descriptions and complete citations. For additional information, the bibliography details a wide range of sources (some nicely annotated) including books, articles, films and videocassettes . A descriptive directory of organizations dealing with energy issues, both domestic and international, is also provided. A single index grants easy access to the book's contents. ENERGY AND AMERICAN SOCIETY: A REFERENCE HANDBOOK is an important reference work that provides solid and useful information on the current status of energy resources in the United States. It is a invaluable tool for both the general public and researchers in the area of

Oil Recovery in a Low-Permeability, Wave-Dominated, Cretaceous, Deltaic Reservoir, Big Wells (San Miguel) Field, South Texas

The Upper Cretaceous Big Wells (San Miguel) reservoir in Dimmit and Zavala Counties, south Texas, produces from a broadly lenticular, wave-dominated deltaic sandstone encased in prodelta and shelf mudstones. An updip porosity pinch-out coincides with a gentle undulation on a uniformly gulfward-dipping monocline and forms a structurally modified stratigraphic trap. The reservoir is relatively tight and has an average porosity of 21% and average permeability of 6 md; wells require fracturing to stimulate production. Ultimate recovery, based on current production trends and technology, is projected to be 57 million bbl, or 29% of the 198 million bbl field. The reservoir is subdivided into an upper, nonproductive, transgressive shelf sandstone and a lower, productive, but intensely bioturbated, deltaic sandstone. The tight, nonproductive upper sandstone seals the reservoir, which consists of four major internal facies. A dip-oriented distributary system carried sediment into the basin. Sediment was then transported along strike (dominantly to the southwest) by longshore drift. Wave action reworked the sands into a beach-ridge plain. The resultant distributary and beach-ridge plain complex exhibits an asymmetric cuspate geometry elongated to the southwest. Landward of the delta system lay a muddy coastal plain. Prodelta and lower shoreface silts and shelf muds were deposited seaward of the deltaic and shore-zone system. The northward transition from thicker and cleaner sandstones of the beach-ridge plain to argillaceous sandstones within and adjacent to the distributary system strongly affects oil recovery from the field. Reservoir permeability and induced-fracture half-lengths (the distance from the well bore to the fracture terminus or half the total length of induced fracture, calculated from pressure transient analysis) decrease dramatically to the north. Consequently, well performance peaks in the beach-plain sediments and decreases northward and updip and downdip into adjacent muddier sediments. Recovery efficiencies of the original oil in place average 50% in the southern half of the pool and drop to 20-30% in the north. However, recovery of movable (nonresidual) oil is highly efficient. About 88% of the nonresidual oil in the pool will be produced. Wave-dominated deltaic reservoirs are characterized by minimal well-to-well variability, excellent internal continuity, and, consequently, maximum efficiency of mobile-oil recovery.

Toward an Agenda for Small Farm Research

Ever since the days of Thomas Jefferson, the expressed intent of the nation's agricultural policy has been to support family farms, particularly small, land-owning farms. Despite expressions of concern and support by both agriculturalists and statesmen, often the effect (if not the intent) of public policy has been to undermine the economic and political support structures of a system of agriculture and rural communities based on land-owning family farms. Recently a widening array of interested groups of citizens have begun to express alarm over the discrepancy between the avowed intent and the ultimate effect of public policythat is, the failure of public policy to achieve the goal of supporting family-owned and operated farms. Increased attention to the changing structure of agriculture has illumined the economic, political, sociological, and ecological ramifications of the trend toward fewer but larger farms (especially highly technical and capitalintensive farms) to policy makers, the private sector, philanthropic organizations, and the public. This increased awareness has created a climate in which the value of small-scale family farms is being reassessed and reaffirmed. Advocates for smaller-scale family farms cite a wide range of adverse social and ecological consequences of current trends in production and marketing and in changes in the structure of agriculture as a rationale for more strenuous political and economic support of smallerscale family farms. In general, these concerns are characterized by a striving to understand the interrelationships between and among production practices, marketing systems, the structure of agriculture, and their impact on ecological and human well-being. For example:

Current trends in production engineering education

Current trends in production engineering education