Pre-design Tool Research Articles

Do occupational therapy pre-discharge home visits affect the longer term outcomes of the discharge process?

Background: Pre-discharge occupational therapy home assessments are routinely performed with older adults in Europe, Australia, and North America. Their primary aim is to facilitate a timely and safe discharge. There has been remarkably little research on the impact of pre-discharge occupational therapy home visits upon the subsequent discharge outcomes. Aim: The purpose of this study was to determine whether pre-discharge home visits from an acute care National Health Service hospital enable an older person to remain at home, whether pre-discharge home visit prevents re-admission to hospital and whether occupational therapy recommendations made on the pre-discharge visit were still complied with two years after discharge. Method: Medical notes of 7 older adults were retrospectively analysed in May 2007 two years after their pre-discharge home visits carried out in 2005. A non-standardised pre-designed data collection tool was used in the medical note analysis. Results: The findings from this exploratory study suggest that occupational therapy pre-discharge home visits may have a positive effect in enabling frail older adults to remain living at home, that re-admissions following home visits in the current sample were for medical rather than functional reasons and that not all the recommendations made by occupational therapists were complied with. Conclusion: It is suggested that further research needs to be done to determine whether occupational therapists in acute care services have a wider role in the management of more frail older adults with long term and deteriorating conditions. There needs to be an acknowledgement that the compensatory approach used within pre-discharge home visits may be of benefit to many older clients.

Semi-Analytical Methods for Different Problems of Diffraction-Radiation by Vertical Circular Cylinders

As in the other fields of mechanics, analytical methods represent an important analysis tool in marine hydrodynamics. The analytical approach is interesting for different reasons : it gives reference results for numerical codes verification, it gives physical insight into some complicated problems, it can be used as a simplified predesign tool, etc. This approach is of course limited to some simplified geometries (cylinders, spheres, ...), and only the case of one or more cylinders, truncated or not, will be considered here. Presented methods are basically eigenfunction expansions whose complexity depends on the boundary conditions. The hydrodynamic boundary value problem (BVP) is formulated within the usual assumptions of potential flow and is additionally simplified by the perturbation method. By using this approach, the highly nonlinear problem decomposes into its linear part and the higher order (second, third, ...) corrections. Also, periodicity is assumed so that the time dependence can be factorized i.e. the frequency domain formulation is adopted. As far as free surface flows are concerned, only cases without or with small forward speed are sufficiently simple to be solved semi-analytically. The problem of the floating body advancing in waves with arbitrary forward speed is far more complicated. These remarks are also valid for the general numerical methods where the case of arbitrary forward speed, even linearized, is still too difficult from numerical point of view, and "it is fair to say that there exists at present no general practical numerical method for the wave resistance problem" [9], and even less for the general seakeeping problem. We note also that, in the case of bluff bodies like cylinders, the assumptions of the potential flow are justified only if the forward speed is less than the product of wave amplitude with wave frequency.

Exergoeconomic analysis of a central heating system from the generation stage to the building envelope

This paper deals with exergoeconomic analysis of a dormitory heated by a conventional boiler in a central heating system. The energy and exergy flows are examined from the generation stage to the envelope of the building. The energy and exergy flows between the stages are obtained using a predesign tool for an optimized building design. Exergetic and exergoeconomic analyses of some heating equipment are comprehensively evaluated. A conventional boiler and a water heater in the central heating system are considered in the analysis. Based on the analysis results obtained, the total exergy input rate is calculated to be 1455kW while the largest exergy loss rate is found to be 987.6kW. Exergetic efficiencies of the conventional boiler and the water heater are also obtained to be 15.6% and 20.4%, respectively.

Turbulent Wall Model for Immersed Boundary Methods

The paper describes the development of a wall model to extend the applicability of Immersed Boundary methods to high Reynolds number flows. A two-layer approach, based on a decomposition of the near-wall region, is adopted. An outer region is governed by the compressible RANS equations which are solved numerically by using a classical finite volume method. In the proximity of the wall, an inner zone is established and modelled by a simplified version of the thin-boundary-layer equations. The simulation platform is based on Cartesian meshes and an immersed boundary technique. It is able to solve the steady Euler/RANS equations in two- and three-dimensional coordinates. The robustness and the accuracy of the methodology are discussed. At present this work represents the last advance of a research activity whose final goal is a fast pre-design tool for aeronautical/industrial applications.

Development and application of a pre-design tool for aero-engine combustors

A software tool was developed to design aero-engine combustors on a preliminary level. Only a small set of input parameters is required to design conventional as well as lean combustors. During the design calculation the combustor contour, the geometry of the desired cooling concept and the air flow distribution within the combustor are optimized. Optimization targets are to minimize the cooling air consumption with respect to the material temperature limits and to reach homogeneous material temperatures as well as a stable combustion. In the case of a staged burner the burner air and fuel fractions are optimized regarding minimal NOx production (qualitative) for the design condition. Off-design calculations on the basis of designed combustors can be executed for engine conditions other than take-off to calculate the altered conditions within the combustor. This paper shows the design and off-design process of the combustor tool in detail. In a second part application examples are given. The presented results show the capabilities of the tool for the pre-design of lean combustors with respect to the trade-off between the reduction of NOx emissions and the reduction of the fuel consumption as well as the capabilities for identifying potential cooling issues.

Thermodynamic analysis of a building using exergy analysis method

This study deals with exergetic assessment of an educational building heated by a conventional boiler in a heating center. The heating system is examined from the generation stage to the envelope of the building. In general the heat loss calculations are made using both energy and exergy analysis methods. The energy and exergy flows between the stages are obtained using a pre-design tool for an optimized building design. Energy and exergy losses are obtained to evaluate the performance of the system. A conventional boiler in the heating center and a fan coil unit in a room are considered in the analysis. Total exergy input rate is calculated to be 694.5 kW, while the largest exergy loss rate is obtained to be 333 kW. Exergetic efficiencies of the conventional boiler and the fan coil unit are also found to be 13.4% and 37.6%, respectively.

A simple realistic modeling of full-scale wet limestone FGD units

A model of wet limestone flue gas desulfurization (WLFGD) system has been developed based on the use of the number of transfer units (NTU) and height of transfer unit (HTU) focused to full-scale coal-fired power plants. The model describes the process occurring in the absorber as the most important step in the WLFGD system by establishing what increase in SO 2 removal can be achieved as the higher levels of nozzles come progressively into service when initially the first spray header is operating alone, and keeping the other operating conditions under control. This relative improvement of the SO 2 removal can be obtained from only one datum: the number of mass transfer units when only the first spray level is on service ( N 1). The model computes the gains in both the volumetric overall mass transfer coefficient and the number of transfer units. The model can be used to evaluate data or changes in an existing full-scale system as well as to evaluate proposed system designs and even as a pre-design tool in relation to the number of spray levels on service under controlled operating conditions. The model is tested on the basis of some data taken from a power plant and from the literature. The model results agree well with the real and published data.

A Domain Decomposition Approach for Efficient Electromagnetic Analysis of the Power Distribution Network of Packaged Electronic Systems

A versatile electromagnetic modeling methodology is presented that is most suitable for use in the computer-aided design of the power distribution network (PDN) of packaged electronics. The method is characterized by modeling flexibility and computational efficiency. These attributes stem from the adoption of a modular approach for the development of the model, where the fine-feature, geometric discontinuities in the network, such as pins, vias, and splits in metallization layers, are modeled separately from the solid planar ground and power metallization portions. In this manner, multiport network models of these discontinuities are developed, making possible their expedient insertion in a discrete electromagnetic model for the solid portions of the metallization. The latter is based on a 2-D integral equation model for the cylindrical transverse electromagnetic field behavior between the metallization planes, for which only electrically important features are preserved and modeled. The utilization of a systematic decomposition approach further enhances the modeling versatility of the proposed method and enables the development of a modeling methodology that is suitable for computer-aided iteration in the electromagnetic performance-aware design of multilayer PDNs. Validation studies are used to demonstrate the efficiency of the proposed methodology and assess its accuracy as a computer-aided tool for PDN predesign.

Effect of Midwing Vortex Generators on V-22 Aircraft Forward-Flight Aerodynamics

The effect of midwing vortex generatorson the V-22 aircraft forward-e ight (airplanemode )aerodynamics using computational e uid dynamics is investigated. The multizone Navier -Stokes method is applied to calculate the e ow over a V-22 wing -fuselage-nacelle cone guration in forward e ight with and without vortex generators. The calculations show that thevortex generatorsreduceseparation and producea favorableeffecton both lift and drag if they are properly designed and placed in the right position. The chordwise location and the incidence angle of the vortex generators are two important design variables in achieving the desired separation alleviation. development. 1i3 Acomprehensive reviewon the V-22 Osprey aero- dynamic development during the past 15 years is given by McVeigh et al. 4 The use of computational e uid dynamics (CFD) has been explored by the present author to analyze the complex aerodynam- ics of the V-22 aircraft. The overall e owe eld about the aircraft in hover 5 andforward-e ightmode 6i8 hasbeensimulatedand analyzed using a multizone, thin-layer Navier- Stokes solution. These anal- yses considered the clean aircraft cone guration, as well as the cone guration with external components. The V-22 employs vortex generators, strakes, and fences to en- hance aerodynamic performance. As a predesign tool, it would be desirable to use the CFD method to evaluate the effect of these de- vicesbefore thee nal evaluation on wind-tunnel or e ight tests. In the presentwork,theeffectofthemidwingfairing(alsocalledoverwing fairing) vortex generators (VGs) on the V-22 forward-e ight aerody- namicsisevaluated.TheuseofVGsisnotstraightforward,however. The effectiveness of VGs depends on how the trailing vortices are generated and used to energize the e ow inside the boundary layer. Theusermighthavetoperformalarge numberoftrial-and-errorex- periments to determine the optimum shape, incidence with respect to the oncoming e ow, and the location of the VGs before e nalizing the design applications. The use of the CFD techniques offers an excellent alternative to the required trial-and-error experiments. The present work is performed in the framework of the steady- state Navier- Stokes solution in a structured grid. A new gridding topology for embedding the VGs in an existing CFD model has been developed. The incorporation of the VGs is performed seam- lessly to allow the effect of VGs to be adequately evaluated. The VGs are not embedded using the chimera-type scheme 9 becauseof inaccuracies due to gridoverlapping and interpolations. The present work addresses the VGs installed on the midwing fairing only, and not the wing-mounted VGs nor the forebody strakes found on the engineering, manufacturing, development (EMD) cone guration of the V-22 aircraft.

Simulation Tools for the Design of Industrial-Scale Membrane Reactors

In this work, two mathematical models of different level of complexity are proposed as tools for design and optimization of the operation of industrial-scale gas separation membrane reactors. First, a simple model is developed, which provides quick predictions and preliminary performance values for the design of the full-scale membrane reactor. This model is a useful tool for process design studies and membrane reactor pre-design. In the second approach, the reactor operation is simulated by detailed membrane reactor modelling, using computational fluid dynamics techniques and taking into account transfer processes that take place in membrane reactors. Results from the application of both models to the design of a membrane reactor operating with highly selective membranes, as used in an Integrated Gasification Combined Cycle plant for better energy efficiency and control of CO2 emissions, are presented and discussed. On the basis of these results, a better insight can be achieved into the factors determining the membrane reactor performance.

Summer cooling with night ventilation for office buildings in moderate climates

The suitability of night ventilation for cooling offices in moderate climates such as that of the UK is first assessed by presenting plots of summer weather data on the bioclimatic chart for three locations within the country. These indicate that most of the external weather conditions lie within the thermal mass and ventilation effectiveness areas of the charts. To confirm this, thermal simulations of a typical office module under a variety of internal conditions and summer weather data were performed. Predictions have shown that internal temperatures can be maintained below the external values for solar and internal gains of up to about 50 W/m 2 of conditioned floor area. Field measurements in a refurbished office have confirmed that temperatures in night-ventilated spaces are generally lower during the following day, especially during the early hours of the working day. Finally, the development of a pre-design tool in the context of IEA Annex 28 on ‘Low-Energy Cooling Systems’ is discussed. The main aim of the tool is to increase the awareness of designers for the energy benefits and the range of parameters for the application of night ventilation as the first means of cooling, so that the need for artificial cooling is minimised or avoided altogether.

PASCOOL ELECTRONIC METAHANDBOOK, PEM☆

In the PASCOOL research program, which is part of the European research project Joule II, one task was dedicated to the development of an interactive software that would summarise the result of the Pascool research program and show the applicability of passive cooling in Mediterranean countries. The aim was to encourage designers to make use of passive cooling strategies in existing and new buildings. Therefore, a software called PEM, Pascool Electronic Metahandbook was created. A selection of buildings from the southern European countries are presented in this software. These buildings had been previously monitored and simulated as a separate task within the Pascool program. In addition, the software contains a climate database and simple predesign tools for dimensioning insulation and solar protection. Version 1.2 of this software was completed in October 1995 and is available on CD-ROM.

Computer assistance for the pre-design of optical instruments

Currently designers use detailed numerical simulation tools for designing charged particle optical instruments. However, these detailed numerical simulation tools are not adequate for the pre-design stage, as they focus on the detailed design of components of the instrument while the pre-design stage deals with the design of the complete instrument. In this article the role of the pre-design stage is analyzed, resulting in a list of requirements for computer assistance at the pre-design stage. These requirements are derived using a model for the process of design. The results of this study are being used by us to develop a pre-design tool.

Comparison of analytical and numerical modeling approaches for sizing of seasonal storage solar heating systems

Analytical and numerical approaches for the predesign of central solar heating plants with seasonal storage (CSHPSS) systems are compared. The results indicate that the analytical approach employed in SOLCHIPS predesign tool is significantly faster and more powerful than the traditional numerical methods for predesign of high solar fraction seasonal storage solar heating systems.

A pre-design tool for a class of parallel processing systems

A properly designed parallel multi-microprocessor system can have significant speed advantage over single-microprocessor system for specific problem domains. There are several types of multi-processor systems architecture which are of interest to us. These are: 1. a. SIMD: Single Instruction Multiple Data machine (e.g., Illiac IV[1].) 2. b. MIMD: Multiple Instruction Multiple Data machine (e.g., C.mmp[2]). 3. c. MSIMD: Multiple SIMD (e.g., MAP[3]) 4. d. PASM: Partitionable SIMD/MIMD machine[4] There are a few questions to be answered for the design of such systems. How good can a multimicroprocessor system be in terms of speed and ‘best’ processing element designed for local processing? How can we re-evaluate the performance of the multi-processor system which employs different types of processing element? The question on speed has been explored by the designers though, to day, such systems, are basically particular processor oriented. The questions on local processor design and over-all evaluation are inter-related. In order to answer such questions for a multi-processor system, a simulator to evaluate the performance of the system is necessary. Simulation of a MC68000 based PASM system has been carried out at Purdue University[5]. While MC68000 is a very powerful machine, there are cases where such systems would be too powerful to be used. Also, this simulator is limited in use in the sense that it is not general purpose and only accepts MC68000 based processors as its processing element.