• Energy Research

This paper focuses on the estimation of the aircraft mass in ground-based applications. Mass is a key parameter for climb prediction. It is currently not available to groundbased trajectory predictors because it is considered a competitive parameter by many airlines. There is hope that the aircraft mass might become widely available someday, but in the meantime it is possible to estimate an equivalent mass from the data already available, assuming the thrust to be known (maximum or reduced climb thrust for example). In a previous paper, two mass estimation methods were compared using simulated data. In this paper, we compare these two mass estimation methods using Mode-C radar data. Both methods estimate the aircraft mass by fitting the modeled energy rate (i.e. the power of the forces acting on the aircraft) with the energy rate observed at several points of the past trajectory. The first method dynamically adjusts the weight parameter so as to fit the energy rate, using an adaptive sensitivity parameter to weight each observation. The second method, introduced in one of our previous publications, estimates the mass by minimizing the quadratic error on the observed energy rate, taking advantage of the polynomial expression of the modeled power when using the BADA model.The actual mass is unavailable in our radar data. However, we can use the estimated mass to compute a trajectory prediction. This prediction is then compared to the actual trajectory giving us some insight on the accuracy of the estimated mass. We have compared the obtained predictions with the ones obtained using the BADA reference mass. The root mean square error on the predicted altitude is reduced by 45 % using the least squares method. With the adaptive method this error is divided by two.

The particle bed reactor designed for 100 to 300 MW power output using hydrogen as a coolant is capable of specific impulses up to 1000 seconds as a nuclear rocket. A single space shuttle compatible vehicle can perform extensive missions from LEO to 3 times GEO and return with multi-ton payloads. The use of hydrogen to directly cool particulate reactor fuel results in a compact, lightweight rocket vehicle, whose duration of usefulness is dependent only upon hydrogen resupply availability. The LEO to GEO mission had a payload capability of 15.4 metric tons with 3.4 meters of shuttle bay. To increase the volume limitation of the shuttle bay, the use of ammonia in the initial boost phase from LEO is used to give greater payload volume with a small decrease in payload mass, 8.7 meters and 12.7 m-tons. 5 refs., 15 figs.

Reactors based on direct cooled HTGR type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out long the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBR's) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed. 12 figs.

Specific excess power (Ps) contours that can be obtained using the energy method; these are important contours that show the performance limits of the aircraft, allow the performance comparison of different aircraft, and help determine the trajectory corresponding to the minimum time to climb without the need for any mathematical operation. Due to the difficulties associated with obtaining Ps contours, there are not many studies on this subject. In order to overcome these difficulties, within the scope of this study, an estimation model was created that will easily predict the Ps contour depending only on flight altitude and Mach number. The data required for modeling are Ps contours obtained in a different study for B737-800 aircraft in 4 different flights. Although it is new, the cuckoo search algorithm (CSA) method, which has proven its success in many optimization problems, has been used for modeling and highly accurate results have been obtained. A different metaheuristic method, particle swarm optimization (PSO), was used to measure the accuracy of the model created. These models constitute the first attempt in the current literature; furthermore the datasets used include real Flight Data Recorder (FDR) values. © 2023 Elsevier Ltd

Owing to their professional activity, flight crews may receive a dose of some millisieverts within a year; airline passengers may also be concerned. The effective dose is to be estimated using various experimental and calculation tools. The European project DOSMAX (Dosimetry of Aircrew Exposure during Solar Maximum) was initiated in 2000 extending to 2004 to complete studies over the current solar cycle during the solar maximum phase. To compare various dosemeters in real conditions simultaneously in the same radiation field, an intercomparison was organised aboard a Paris-Tokyo round-trip flight. Both passive and active detectors were used. Good agreement was observed for instruments determining the different components of the radiation field; the mean ambient dose equivalent for the round trip was 129 +/- 10 microSv. The agreement of values obtained for the total dose obtained by measurements and by calculations is very satisfying.

This document provides Appendices A thru K of this report. The topics discussed respectively are: radiation induced embrittlement and annealing of reactor pressure vessel steels; loss of coolant accident blowdown analyses; LOCA blowdown response analyses; non-seismic structural response analyses; seismic analyses; S'' seal integrity; reactor transient analyses; fire protection; aircraft impacts; and boric acid induced corrosion. (FI).

The purpose of this report is to summarize the results of the US Department of Energy (DOE) Analysis Team's analyses of Soviet designed VVERs (Water-cooled, Water-moderated Energy Reactor). The principle objective of this undertaking is to provide a basis to better understand the safety related features of the Soviet designed VVERs to be better prepared to respond domestically in the event of an accident at such a unit. The USDOE Team's analyses are presented together with supporting and background information. The report is structured to allow the reader to develop an understanding of safety related features of Soviet designed VVERs (as well as the probable behavior of these units under a variety of off normal conditions), to understand the USDOE Team's analyses of Soviet designed VVERs, and to formulate informed opinions.

Abstract copyright UK Data Service and data collection copyright owner.The Opinions and Lifestyle Survey, formerly known as ONS Opinions Survey or Omnibus, is a regular, multi-purpose survey which was carried out in eight months of the year from 1990 until April 2005, when it began to run monthly. Following the 'Fit for Future' consultation carried out by ONS at the beginning of 2014, the decision was taken to revert to running the survey in eight months of the year only; therefore from April 2014 the survey does not run in March, June, September or December. The study was originally set up to meet the needs of government departments for a survey that used short and simple sets of questions, had greater statistical reliability than private sector omnibus surveys and a properly designed random sample. Now, however, an increasing number of academics are finding it a valuable research tool. The Opinions and Lifestyle Survey is used for a number of purposes, for example: to provide quick answers to questions of immediate interest to provide information on topics that do not require a full survey to develop and pilot questions for other surveys to sift for subgroups that can be followed up in another survey From April 2012 the ONS Opinions Survey changed its name to the Opinions and Lifestyle Survey following the merger of the non-EU-SILC questions from the General Lifestyle Survey. Secure Access Opinions and Lifestyle Survey data Some Opinions modules, covering disability, general lifestyle, religion, non-resident parental contact, contact after separation, cervical cancer screening, contraception, illness and activity limitation, are only available under Secure Access conditions. See Opinions and Lifestyle Survey: Secure Access for details. Main Topics:Each month's questionnaire consists of two elements: core questions, covering demographic information, are asked each month together with non-core questions that vary from month to month. The non-core questions for this month were: Tobacco consumption (Module 210): this module was asked on behalf of HM Revenue and Customs to help estimate the amount of tobacco consumed as cigarettes. Due to the potentially sensitive nature of the data within this module, cases for respondents aged under 18 have been removed. Disability monitoring (Module 363b): this module was asked on behalf of the Department for Work and Pensions (DWP) which is interested in information on disability and includes two questions that ask about awareness of the Disability Discrimination Act. The module aims to identify the scale of problems those with long-term illnesses or disabilities have accessing goods, facilities and services. The module has changed since the last time it was run and some questions have been removed. Climate change and transport (Module 377/377c): this module was asked on behalf of the Department for Transport and has been adapted from last year. The questions within Module 377 are repeated and deal with respondents' views about transport and climate change. M377c consists of new questions which relate to travel habits and respondents' attitudes to lowering CO2 emissions. Multi-stage stratified random sample Face-to-face interview