Energy resource demands of food production

Historically food has been produced by using solar energy, natural fertilizer and manual labor. However, as populations have increased food products had to be increased proportionately so it has become necessary to use industrial equipment instead of manual labor and artificial fertilizer in place of manure. Thus, in modern agriculture, fuel energy has largely replaced animate energy. This has made the food delivery system one of the most energy intensive industries. It is apparent that this demand for energy will increase because the world population is expected to double by the end of the century and hence will require rapid increases in food production.This paper sets forth the energy supply and demand situation as it concerns food production. Also, considered are externalities such as climate and population. Finally, an agenda for future research in the energy-food sector is presented.     

Flame Retardant Cable?Analysis and Recommendations

An overview of the flame resistance capabilities of electric wire and cable used in industrial and utility installations is given, along with current and proposed flame tests and their intended purposes, recommended compounds, constructions, and installation practices for cable tray installations.     

An Automatic Zeroing Circuit

A circuit to remove an offset from a signal is described. The circuit uses a simple digital memory to store the offset, and the output is the difference between this stored offset and the input signal. The drift is small, the bandwidth wide, and the input voltage may be obtained in digital form.     

Estimating the Number of Items on Life Test

If n items are on life test where n is unknown, and failures are observed either until time T has elapsed or until r failures have occurred, then an estimate of n can be obtained. Both maximum likelihood and Bayes estimates are obtained and both known and unknown failure distributions are considered.     

Parallel compilation: A design and its application to SIMULA 67

A design for a separate compilation facility for the SIMULA 67 programming language is presented. The paper explores the problems with existing separate compilation schemes, and proposes a new scheme that allows top-down, bottom-up, or even parallel development and integration of program modules. An evaluation of the proposal and a discussion of its applicability to other languages are then given.     

Self-Balancing System for Medical and Physiological Instrumentation

There is a need in medical and physiological instrumentation for a system that can automatically correct baseline shifts. Some cases where this need arises are discussed. A self-balancing system that can be used as a general-purpose unit has been developed and is described. It consists of a binary counter, a digital to analog converter, and logic circuits. The described system automatically balances dc shifts in signals with a range of 6 V. Balancing time is less than 15 ms. The system is designed to work with tape or chart recorders with input range of ± 1 to ± 3 V. Some design parameters of this system are discussed briefly.     

Approximation programming of chemical processes—2: computational difficulties

Part 1 of this series presents successful results in implementing quadratic approximation programming for optimization of processes modelled with Monsanto's FLOWTRAN®³ system. Detailed analysis of the computations indicates that the optimization of the approximate quadratic models provides one of the main computational problems. This paper describes some of these problems and our solutions, and indicates further improvements which should be investigated.     

Three-dimensional finite-element analysis of laminated composites

A three-dimensional finite-element analysis treating the mechanical response of thick laminated composite plates in bending is presented. An isoparametric solid element with a cubic displacement expansion in planform and a linear variation through the thickness is used to model each layer of the laminate. The degrees-of-freedom of the element are retained at its boundaries so that interconnections between lamina with different fiber orientations can be made at their interfaces. An incore version of the conjugate gradient technique, which does not have bandwidth restrictions, is used to minimize the total potential energy of the system with the number of iterations to convergence being about one-fifth the total global degrees-of-freedom. Because a three-dimensional analysis is used, the effects of thickness-stretching, transverse shear, extension, and bending deformations are obtained. Comparisons with three-dimensional elasticity solutions are in excellent agreement and show the necessity of having individual elements for each layer when they have different fiber orientations and when the plates are thick.     

Effect of pictorial integration on children's incidental learning.

Conducted 2 experiments to examine 192 8-, 11-, and 14-yr-old children's incidental learning with the central and incidental pictorial elements in each stimulus (a) presented as separate entities (standard condition), (b) depicted together in an action relation (2 types-weak action and strong action), or (c) depicted together in a static relation. Following a learning task in which attention to a single element in each stimulus was required, incidental learning was measured by having the S indicate the incidental feature associated with each central component. Results show that incidental learning was higher with the action than the standard materials, but the developmental trend in these scores was little affected by pictorial integration. While extending the generality of previous incidental learning results, these data contrast with evidence showing an increase with age in the effects of action portrayal on intentional learning of pictorial associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)