Higher Net Energy Research Articles

New Advances and Concepts in Amputee Management After Treatment for Bone and Soft-Tissue Sarcomas

Amputation is still necessary to achieve disease-free margins in some patients with osteogenic sarcoma. Improving the quality of life for this largely young patient population has become increasingly important considering the dramatic increase in their survival rate. A multidisciplinary approach should include prosthetic devices that are comfortable and lightweight, and produce an energy-efficient gait, an aggressive postoperative rehabilitation, and an objective evaluation of progress. This approach will help improve the high net energy expenditure of ambulation and the asymmetrical stance time experienced by this group of individuals and allow them to gain equal status in society.

The use of partly-hydrolyzed and untreated straw meal in the feeding of breeding sows. 5. Concentration, production and absorption of volatile fatty acids in the large intestine

In 2 experiments with a total of 28 breeding sows of the country species studies were made of the fermentation, production and absorption of volatile fatty acids (VFA) in the large intestine after feeding variously treated straw materials in concentrate--straw meal mixtures. Experiment 1 ascertained that supplements of untreated (I), HCl treated (II) and partly hydrolysed straw meal (III, treatment with subsequent steaming) caused a decrease of the VFA concentration as well as considerable molar changes of the VFA in the caecal and colonal digesta in comparison of the sole feeding with concentrate (IV). The straw fibre integration increased the molar acetate quota at the expense decreased propionate and butyrate fermentation. Considering the straw meal variants this effects was least distinct after the feeding of partly hydrolysed straw meal (III). In experiment 2, which comprised the simultaneous ascertainment of VFA production in the feeding variants I and III and which was based on a representative number of animals per test group (n = 10), there were significant differences between the production quotas (I = 992; III = 1,300 mmol/animal.d) and in the absorption quotas of VFA (I = 63; II = 78%). The digestible energy from the VFA in the large intestine amounted to 711 kJ/d (I) and 1,183 kJ/d (III). The derived higher net energy gain from the hydrolysed straw product (III) was calculated at 590 kJ (40EFUpig/kg DM) and discussed together with results of feed value increase from the digestibility experiments.

Biomass chemicals: Improvement in quality and quantity with physiological regulators

The search for alternative biomass energy forms has centered on two approaches: (1) production of cellulose fiber in biomass of low net energy value per unit weight, such as wood and bagasse, and (2) hydrocarbons of high net energy value per unit weight for use as chemical feedstocks and substitutes for petroleum. Major plant chemical products include oleoresin from pine ( Pinus elliottii Engelm., P. palustris Mill.), rubber from the rubber tree ( Hevea brasiliensis Muell.), and guayule shrub ( Parthenium argentatum Gray) and sugar from sugarcane ( Saccharum spp.). Genetic selections with lower natural yields tend to respond the most to bioregulators, and yields after treatment may equal those of the best selections also receiving the treatment. Ethylene may be a unifying natural bioregulator that can increase deposition of biomass chemicals in all four of these systems. The underlying success of the bioregulators is that assimilates are partitioned into extractives and sugar instead of vegetative growth. Examples include the use of paraquat, diquat, and 2-chloroethylphosphonic acid (CEPA) for stimulating the synthesis of oleoresin, CEPA for prolonging the flow of rubber and increasing rubber synthesis in the rubber tree, and triethylamines of chlorinated phenoxy compounds for stimulating rubber production in guayule. In sugarcane, gibberellic acid (GA 3) increases internodal elongation. Glyphosate, CEPA and other regulators increase the deposition of sucrose, diquat and CEPA inhibit flowering, and paraquat desiccates leaves just prior to harvest to facilitate leaf removal or burning just prior to harvest. The cellular compartmentalization for the synthesis of these plant chemicals is unique for each species, and dictates cultural and harvest techniques. Oleoresin is produced in the epithelial cells of resin canals and parenchyma of rays. Hevea rubber is produced in articulated laticifers. Hevea rubber and pine oleoresin are obtained by stripping away bark at various intervals during the year. The main source of guayule rubber is bark parenchyma and it is obtained by grinding the shrub, and coagulating and extracting the rubber. Sucrose is synthesized in the cytosol, stored in plastids and obtained by harvesting the cane and crushing it. The mode of action and pathways for the success of these physiological regulators are discussed.

Net energy production history of the Geysers geothermal project

Geothermal projects at the Geysers, California, have relatively high net energy ratios for electricity-production facilities. Comparison of the net cumulative electrical energy generated at the Geysers with the cumulative thermal energy invested for constrction and operation of the facility indicates a favorable energy return, even during periods of rapid systems expansion.