Three stage rocket vehicle with parallel staging

A three stage rocket vehicle has a large forward propellant tank and a small aft propellant tank axially aligned. Secured to the rear end of the aft propellant tank is an engine mount structure carrying rocket engines. Offset and secured to the propellant tanks is a payload structure. The propellants from the large forward tank are fed into the aft propellant tank. This arrangement enables the vehicle to parallel stage its use of engines and components and results in significant payload capability. The design and components fully utilize existing space shuttle elements and tooling

SARDSRN: A NEURAL NETWORK SHIFT-REDUCE PARSER

Simple Recurrent Networks (SRNs) have been widely used in natural language tasks. SARDSRN extends the SRN by explicitly representing the input sequence in a SARDNET self-organizing map. The distributed SRN component leads to good generalization and robust cognitive properties, whereas the SARDNET map provides exact representations of the sentence constituents. This combination allows SARDSRN to learn to parse sentences with more complicated structure than can the SRN alone, and suggests that the approach could scale up to realistic natural language

Measuring sustainability along the food supply chain: further development of a tool for measuring environmental impact of a food business

The sustainability of the food industry with respect to its environmental impact and use of resources is one of the key challenges it faces. Tools and systems are available to measure these but require specialist knowledge in order to apply them. A simple tool for measuring environmental impact was recently published (Salvá et al., 2013) that quantifies various aspects of a food business and gives an overview of its sustainability. This poster describes the further development of this tool so that the parameters can be measured in a more objective and systematic way, using principles from sensory science. The parameters were scaled by defining higher and lower anchors and intermediate points along otherwise-unstructured line scales. A number of food businesses were invited to complete the questionnaire. Scoring was done by marking the point along each scale at which the business believed it lay. By setting up the questionnaire in a spreadsheet, e.g. Excel, the results were produced rapidly, with minimum effort. Data were analysed by presenting the scores on a spider diagram. Differences between businesses were compared statistically in a separate analysis. The study demonstrated that the tool was easy to use and provided both industry, their suppliers and their customers with easily-interpretable results. The tool could be used for longer-term planning and for showing how a business was developing its sustainability

A study of methods to predict and measure the transmission of sound through the walls of light aircraft. A survey of techniques for visualization of noise fields

A survey of the most widely used methods for visualizing acoustic phenomena is presented. Emphasis is placed on acoustic processes in the audible frequencies. Many visual problems are analyzed on computer graphic systems. A brief description of the current technology in computer graphics is included. The visualization technique survey will serve as basis for recommending an optimum scheme for displaying acoustic fields on computer graphic systems

United States Nuclear Export Controls

This article will explore the U.S. nuclear export controls regime. It will initially discuss controls affecting the export of nuclear material, facilities, and specially designed components of nuclear facilities. This section will specifically consider export licensing procedures and requirements, agreements for nuclear cooperation, the specific export criteria for major nuclear cooperation, as well as the necessary policy determination. Then the Article will discuss the procedures and requirements for obtaining a license to export dual-use equipment, the authorization necessary for the export of nuclear technology and the subsequent arrangement process, which further aids in the implementation of U.S. non-proliferation policies

Measurement of interface pressure in interference fits

When components such as bearings or gears are pressed onto a shaft, the resulting interference induces a pressure at the interface. The size of this pressure is important as many components fail because fatigue initiates from press-fit stress concentrations. The aim of the present work was to develop ultrasound as a tool for non-destructive determination of press-fit contact pressures. An interference fit interface behaves like a spring. If the pressure is high, there are few air gaps, so it is very stiff and allows transmission of an ultrasonic wave. If the pressure is low, then interface stiffness is lower and most ultrasound is reflected. A spring model was used to determine maps of contact stiffness from interference-fit ultrasonic reflection data. A calibration procedure was then used to determine the pressure. The interface contact pressure has been determined for a number of different press- and shrink-fit cases. The results show a central region of approximately uniform pressure with edge stress at the contact sides. The magnitude of the pressure in the central region agrees well with the elastic Lamé analysis. In the more severe press-fit cases, the surfaces scuffed which led to anomalies in the reflected ultrasound. These anomalies were associated with regions of surface damage at the interface. The average contact pressure in a shrink-fit and press-fit joint were similar. However, in the shrink-fit joint more uneven contact pressure was observed with regions of poor conformity. This could be because the action of pressing on a sleeve plastically smooths out long wavelength roughness, leading to a more conforming surface

The potential scale of aeolian structures on Venus

Simulations of the Venusian aeolian environment with the Venus Wind Tunnel have shown that microdunes are formed during the entrainment of sand-sized material. These structures are several tens of centimeters long (2-3 cm high) and combine the morphological and behavioral characteristics of both full-scale terrestrial dunes and current ripples formed in subaqueous environments. Their similarity to both reflects the fact that the Venusian atmosphere has a density intermediate between air and water. Although the development of microdunes in the wind tunnel experiments was limited by tunnel dimensions, it is possible to make some predictions about their potential size on Venus, and the potential size of related aeolian structures. Microdunes are fluid-filled structures (as are dunes and current ripples) and as such have no theoretical upper limit to their size from a fluid dynamics viewpoint. Limitations to size observed in subaqueous structures are set by, for example, water depth; limitations to the size of dunes are set by, for example, sand supply. It is therefore reasonable to suppose that the microdunes on Venus could evolve into much larger features than those observed in experiments. In addition, the researchers note that current ripples (which are closely related to microdunes) are often found in association with giant ripples that have dimensions similar to aeolian dunes. Thus, it may be reasonable to assume that analogous large scale structures occur on Venus. Both (terrestrial) aeolian and subaqueous environments generate structures in excess of one hundred meters in wavelength. Such dimensions may therefore be applicable to Venusian bedforms. Analysis of Magellan data may resolve the issue