Metal tube used as solar engine

Ends of metal tube are fastened to axles which are supported on bearings so tube can rotate about its long axis while subjected to invariant bending moment that stresses it along longitudinal axis of rotation. Heat absorbed leads to expansion of metal, which unbalances internal forces and generates rotational moment in tube

Solid medium thermal engine

A device is described which uses a single phase metallic working substance to convert thermal energy directly into mechanical energy. The device consists of a cylindrical metal tube which is free to rotate about its axis while being subjected to continuous bending moment stresses along the longitudinal axis of rotation. The stressing causes portions of the tube to be under compression while other parts are under tension which in turn causes the tube to rotate and provide mechanical energy

Electropneumatic rheostat regulates high current

Electropneumatic rheostat maintains a constant direct current in each of several high-power parallel loads, of variable resistance, across a single source. It provides current regulation at any preset value by dissipating the proper amount of energy thermally, and uses a column of mercury to vary the effective length of a resistance element

Effects of Condensed Corn Distillers Solubles on Steer Performance and Carcass Composition

Condensed corn distillers solubles (CCDS) have become a prevalent feed source in Iowa. In this study, we looked at the impact of CCDS in finishing steer rations and the influence CCDS had on steer performance as well as carcass composition. In the first year of the study, 112 steers were randomly sorted into four equal groups where each group contained four pens and 7 steers per pen. The second year of the study was a repeat of the first year however a fifth treatment was added in which 28 steers were placed on pasture and provided a finishing grain diet. The first of the four treatments consisted of the feedlot group (F), which was placed directly in to the feedlot and fed shelled corn, alfalfa hay, a protein, vitamin, and mineral supplement, and molasses. The second treatment was feedlot + CCDS (F+CCDS). This treatment group was placed directly into the feedlot and received shelled corn, alfalfa hay, a protein, vitamin and mineral supplement, and CCDS. The third treatment group was backgrounded on pasture for the duration of the summer (P), and then put into the feedlot where they received the same ration as the F group. The fourth treatment group was backgrounded on pasture for the duration of the summer, and while on pasture had access to free choice CCDS via a lick tank (P+CCDS). In the fall this group was placed into the feedlot and received the same ration as the F+CCDS group. In the second year, a fifth treatment was added, called the pasture finishing group (PF). The steers in this treatment received the same shelled corn, and protein, vitamin and mineral supplement, and CCDS as the cattle in the F+CCDS treatment, minus the alfalfa hay. Grass consumption for the PF cattle was estimated using the 2007 BRANDS program. Although the study is not yet completed, it appears as though CCDS can be implemented in feedlot rations successfully. The existing trends of the study would indicate that a feedlot ration containing CCDS will slightly increase steer ADG and improve F:G, without effecting QG

Progress Report: Effects of Condensed Corn Distillers Solubles on Steer Performance and Carcass Composition

This study looked at the use of condensed corn distillers solubles (CCDS) as a feed source for steers backgrounded on pasture as well as steers being fed in the feedlot. In addition, a treatment group was finished on pasture with CCDS as a part of their ration. The two feedlot rations were isocaloric and isonitrogenous. The pasture finishing steers were fed a ration based on the feedlot ration containing CCDS but were not fed any hay. The goal of this study was to establish the benefits, as well as the limitations, of feeding CCDS to feedlot and backgrounded steers

Analysis and Experimental Evaluation of Power Line Transmission Parameters for Power Line Communication

The article describes a way of evaluating the power line channel frequency response and input impedance by means of the linear time-invariant (LTI) power line generator. Two possible methods are introduced for the calculation of primary parameters: the first method depends on the physical realization and physical dimension of the cable, and the second method is derived from the data provided by typical electrical cable manufacturers. Based on these methods, a comparison of transfer functions was made. This is followed by measurement evaluation and numerical verification on a simple topology

Agroecology: promoting the transition towards sustainability

En este artículo se define agroecología como la aplicación de los conceptos y prinicipios ecológicos al diseño y manejo de los sistemas alimentarios sostenibles. Se presentan los argumentos principales que sostienen la validez, importancia y pertinencia del enfoque agroecológico, no solo para entender los procesos involucrados en la producción de alimentos, sino para proponer alternativas que conduzcan a esos procesos para operar en sistemas sostenibles. El concepto clave, que guía el razonamiento metodológico y epistemológico en este análisis, es el de sostenibilidad. Para alcanzar sostenibilidad la metodología agroecológica no solo se ancla en la Ecología, lo cual se describe en el trabajo, sino que percibe la producción de alimentos como un proceso que involucra a los productores y consumidores interactuando en forma dinámica.In this article agroecology is defined as the application of ecological concepts and principles to the design and management of sustainable food systems. The principal arguments are presented that support the validity, importance, and application of the agroecologial focus, not only in order to understand the processes involved in food production, but also to propose alternatives that help these processes to operate in sustainable systems. The key concept that guides the methodological and epitistemalogical rationale of this analysis is sustainability. In order to achieve sustainability the agroecological methodology not only links to Ecology, as is described in the text, but perceives food production as a process involving producers and consumers operating in a dynamic interaction

Evidence synthesis as the basis for decision analysis: a method of selecting the best agricultural practices for multiple ecosystem services

Agricultural management practices have impacts not only on crops and livestock, but also on soil, water, wildlife, and ecosystem services. Agricultural research provides evidence about these impacts, but it is unclear how this evidence should be used to make decisions. Two methods are widely used in decision making: evidence synthesis and decision analysis. However, a system of evidence-based decision making that integrates these two methods has not yet been established. Moreover, the standard methods of evidence synthesis have a narrow focus (e.g., the effects of one management practice), but the standard methods of decision analysis have a wide focus (e.g., the comparative effectiveness of multiple management practices). Thus, there is a mismatch between the outputs from evidence synthesis and the inputs that are needed for decision analysis. We show how evidence for a wide range of agricultural practices can be reviewed and summarized simultaneously (“subject-wide evidence synthesis”), and how this evidence can be assessed by experts and used for decision making (“multiple-criteria decision analysis”). We show how these methods could be used by The Nature Conservancy (TNC) in California to select the best management practices for multiple ecosystem services in Mediterranean-type farmland and rangeland, based on a subject-wide evidence synthesis that was published by Conservation Evidence (www.conservationevidence.com). This method of “evidence-based decision analysis” could be used at different scales, from the local scale (farmers deciding which practices to adopt) to the national or international scale (policy makers deciding which practices to support through agricultural subsidies or other payments for ecosystem services). We discuss the strengths and weaknesses of this method, and we suggest some general principles for improving evidence synthesis as the basis for multi-criteria decision analysis

The Current Status and Work of Three Rs Centres and Platforms in Europe*

The adoption of Directive 2010/63/EU on the protection of animals used for scientific purposes has given a major push to the formation of Three Rs initiatives in the form of centres and platforms. These centres and platforms are dedicated to the so-called Three Rs, which are the Replacement, Reduction and Refinement of animal use in experiments. ATLA's 50th Anniversary year has seen the publication of two articles on European Three Rs centres and platforms. The first of these was about the progressive rise in their numbers and about their founding history; this second part focuses on their current status and activities. This article takes a closer look at their financial and organisational structures, describes their Three Rs focus and core activities (dissemination, education, implementation, scientific quality/translatability, ethics), and presents their areas of responsibility and projects in detail. This overview of the work and diverse structures of the Three Rs centres and platforms is not only intended to bring them closer to the reader, but also to provide role models and show examples of how such Three Rs centres and platforms could be made sustainable. The Three Rs centres and platforms are very important focal points and play an immense role as facilitators of Directive 2010/63/EU 'on the ground' in their respective countries. They are also invaluable for the wide dissemination of information and for promoting the implementation of the Three Rs in general

The Rise of Three Rs Centres and Platforms in Europe*

Public awareness and discussion about animal experiments and replacement methods has greatly increased in recent years. The term 'the Three Rs', which stands for the Replacement, Reduction and Refinement of animal experiments, is inseparably linked in this context. A common goal within the Three Rs scientific community is to develop predictive non-animal models and to better integrate all available data from in vitro, in silico and omics technologies into regulatory decision-making processes regarding, for example, the toxicity of chemicals, drugs or food ingredients. In addition, it is a general concern to implement (human) non-animal methods in basic research. Toward these efforts, there has been an ever-increasing number of Three Rs centres and platforms established over recent years - not only to develop novel methods, but also to disseminate knowledge and help to implement the Three Rs principles in policies and education. The adoption of Directive 2010/63/EU on the protection of animals used for scientific purposes gave a strong impetus to the creation of Three Rs initiatives, in the form of centres and platforms. As the first of a series of papers, this article gives an overview of the European Three Rs centres and platforms, and their historical development. The subsequent articles, to be published over the course of ATLA's 50th Anniversary year, will summarise the current focus and tasks as well as the future and the plans of the Three Rs centres and platforms. The Three Rs centres and platforms are very important points of contact and play an immense role in their respective countries as 'on the ground' facilitators of Directive 2010/63/EU. They are also invaluable for the widespread dissemination of information and for promoting implementation of the Three Rs in general