Interactive experimenters' planning procedures and mission control

The computerized mission control and planning system routinely generates a 24-hour schedule in one hour of operator time by including time dimensions into experimental planning procedures. Planning is validated interactively as it is being generated segment by segment in the frame of specific event times. The planner simply points a light pen at the time mark of interest on the time line for entering specific event times into the schedule

Misalignment estimation software system

A system of computer software, spacecraft, and ground system activity is described that enables spacecraft startrackers and inertial assemblies to be aligned and calibrated from the ground after the spacecraft has achieved orbit. The system generates in the uplink flow an exercise designed to render misalignments visible, and sends the exercise to the spacecraft where the spacecraft inserts the misalignment into the information in the form of attitude sensor error. The information is downlinked for processing into misalignment estimates to be used for correcting spacecraft model at data base

Payload operations control center network (POCCNET) systems definition phase study report

The results of the studies performed during the systems definition phase of POCCNET are presented. The concept of POCCNET as a system of standard POCCs is described and an analysis of system requirements is also included. Alternative systems concepts were evaluated as well as various methods for development of reliable reusable software. A number of POCC application areas, such as command management, on board computer support, and simulation were also studied. Other areas of investigation included the operation of POCCNET systems, the facility requirements and usage

Next Generation Internet Overview

Various issues associated with next generation Internet are presented in viewgraph form. Specific topics include: 1) Internet architecture; 2) NASA's advanced networking; 3) Internet capability, capacity and applications; and 4) Systems engineering

Dissecting the Workforce and Workplace for Clinical Endocrinology, and the Work of Endocrinologists Early in Their Careers

[Excerpt] No national mechanism is in place for an informed, penetrating, and systematic assessment of the physician workforce such as that achieved by the National Science Foundation (NSF) for the periodic evaluation of the nation’s scientists and engineers. Likewise, knowledge of the workforce for clinical research is enigmatic and fragmentary despite the serial recommendations of “blue-ribbon” panels to establish a protocol for the recurrent assessment of clinical investigators early in their careers. Failure to adopt a national system for producing timely, high-quality data on the professional activities of physicians limits the application of improvement tools for advancing clinical investigation and ultimately improving clinical practice. The present study was designed as a pilot project to test the feasibility of using Web-based surveys to estimate the administrative, clinical, didactic, and research work of subspecialty physicians employed in academic, clinical, federal, and pharmaceutical workplaces. Physician members of The Endocrine Society (TES) were used as surrogate prototypes of a subspecialty workforce because of their manageable number and investigative tradition. The results establish that Web-based surveys provide a tool to assess the activities of a decentralized workforce employed in disparate workplaces and underscore the value of focusing on physician work within the context of particular workplaces within a subspecialty. Our report also provides a new and timely snapshot of the amount and types of research performed by clinically trained endocrinologists and offers an evidenced-based framework for improving the investigative workforce in this medical subspecialty

Évolution de la qualité de l'eau dans le réseau de distribution de la ville de Montréal

Dans la présente étude, nous montrons l'évolution de l'eau dans un réseau de distribution. Ce réseau a été construit dans les années 70 à l'aide de conduites d'acier ou de fonte ductile munies d'un revêtement intérieur de ciment. Il est alimenté par des eaux de très bonne qualité qui circulent d'abord dans une suite de conduites maîtresses (de 2 700 mm à 900 mm) jusqu'à un secteur de petites conduites maillées (200 et 300 mm). Des échantillons d'eau ont été prélevés à 14 reprises durant une année, le long de la conduite maîtresse (le temps de séjour y varie de 0 h à 13,6 h) et dans le secteur de petites conduites (de 13,6 h à 18,4 h). Nous avons mesuré la température, le pH, plusieurs sous-produits de désinfection dont les trihalométhanes et les aldéhydes, le carbone organique total et biodégradable ainsi que les concentrations de bactéries hétérotrophes aérobies et anaérobies facultatives (BHA) et les comptes directs totaux mesurés en épifluorescence. Le réseau a très peu d'effet sur l'évolution des sous-produits de désinfection. En effet, les résultats obtenus à partir des échantillons témoins (eaux traitées conservées dans un flacon propre à la même température que dans le réseau) sont semblables à ceux obtenus à partir des eaux prélevées dans le réseau de distribution.Les concentrations de bactéries ainsi que les concentrations de CODB sont assez stables dans le réseau. Il est intéressant de noter qu'il y a de 0,2 à 0,45 mg/l de CODB, ce qui est supérieur à la concentration minimale de 0,15 mg/l requise pour la croissance des bactéries. Par contre, le chlore résiduel libre est toujours supérieur à 0,20 mg/l. Une seule exception, le 11 juillet 1994, dans le secteur de petites conduites, le chlore résiduel a baissé jusqu'à 0,16 mg/l. Durant cette journée, nous avons observé une légère augmentation des comptes directs totaux mesurés en épifluorescence.Studies were performed to follow the changes in water quality along a distribution system. The distribution system under study is divided into two parts: main pipes starting from the plant (from 2 700 mm to 900 mm diameter) feeding a small pipes sector (200 mm and 300 mm diameter). Residence times range from 0 to 13.6 hours in main pipes and from 13.6 h to 18.4 h in small pipes. All pipes are made of steel or ductile iron and their interior is lined with concrete; there is therefore little corrosion. Since the raw water is of such high quality, the treatment plant is very simple: a direct filtration on sand followed by ozonation and chlorine disinfection. Samples were taken on 14 occasions, during a full year period, in the distribution system and in the treatment plant after chlorination. These last samples were incubated in clean flasks at the network temperature. Measurements of temperature, pH, disinfection by-products (trihalomethanes, aldehydes, haloacetonitriles, haloacetones and chloropicrine), total organic carbon (TOC), biodegradable dissolved organic carbon (BDOC) and number of bacteria (heterotrophic plate count and total direct count by epifluorescence) were completed.The distribution network seems to have very little effect on chlorine demand and disinfection by-products. Results from water incubated in flasks are similar to those from distribution network. After more than 18 hours contact time, the chlorine residual is still higher than 0.2 mg/l in most of the samples taken in the distribution network and in the flask. It should be noted that the initial chlorine concentrations range from 0.65 mg/l (cold water) to 1.00 mg/l (warm water). Chlorine demand and trihalomethane (THM) curves are typical, a rapid increase with time followed by a relatively stable level. THM concentrations in the distribution network are low: a typical value of 14 µg/l after 13.6 hours contact time is detected. The maximum concentration of 43 µg/l of total THM was measured in a dead end. In this latter sample, 42 % of the THM was present as bromodichloromethane and 39 % as chloroform. Other by-products such as haloacetonitrile, haloacetone and chloropicrine were always detected in very small concentrations.Aldehyde concentrations in treated water were low, between 21 and 42 µg/l. These concentrations were stable throughout the distribution system. Fixed and free biomass seems to have very little effect on these biodegradable compounds. These results were confirmed by BDOC results. BDOC in treated water ranges from 0.2 to 0.45 mg/l and remains stable in the distribution system. These low BDOC concentrations and the chlorine residual of approximately 0.2 mg/l seem to be sufficient to prevent regrowth in the distribution system. Total direct counts by epifluorescence showed almost no increase of bacterial density except for the July 11th sample. This is the only day where the free chlorine residual dropped below 0.2 mg/l, with values of free chlorine residual dropping as low as 0.16 mg/l

Dynamic Characterisation of Fibre-Optic Temperature Sensors for Physiological Monitoring

Fast, miniature temperature sensors are required for various biomedical applications. Fibre-optics are particularly suited to minimally invasive procedures, and many types of fibre-optic temperature sensors have been demonstrated. In applications where rapidly varying temperatures are present, a fast and well-known response time is important; however, in many cases, the dynamic behaviour of the sensor is not well-known. In this article, we investigate the dynamic response of a polymer-based interferometric temperature sensor, using both an experimental technique employing optical heating with a pulsed laser, and a computational heat transfer model based on the finite element method. Our results show that the sensor has a time constant on the order of milliseconds and a −6 dB bandwidth of up to 178 Hz, indicating its suitability for applications such as flow measurement by thermal techniques, photothermal spectroscopy, and monitoring of thermal treatments

Le Traitement des Eaux de Consommation : La Nécessité d'une Recherche en Chimie de l'Eau

L'objectif principal de cet article est de montrer que les travaux de recherche en chimie de l'eau sont absolument nécessaires à la compréhension des phénomènes régissant la qualité des eaux de consommation produites et distribuées, ainsi qu'au développement de technologies innovantes dans le domaine du traitement de ces eaux. Pour l'atteindre, il a été choisi de présenter trois exemples des recherches menées à l'Université de Poitiers et à l'École Polytechnique de Montréal : deux exemples de recherche fondamentale, sur les matières organiques naturelles et sur les mécanismes d'oxydation par les radicaux hydroxyle et un exemple de la recherche d'application, sur l'évolution de la qualité de l'eau lors de son traitement biologique par ozonation couplée à la filtration sur charbon actif en grains.The main purpose of this paper is to demonstrate that a better understanding of chemical reactions and a better technologies development for the drinking water treatment absolutly needs research in water chemistry. In order to reach this objective, two examples of recent fundamental research works in water chemistry and one example of research applied to drinking water treatment have been selected.The first one concerns a fundamental research on characterization and analysis of natural organic matter. Nowadays, the main analytical tools used for quantification of NOM are DOC (BDOC for the biodegradable fraction) and UV-absorbance. However, a better knowledge of NOM would be useful to predict water quality and determination of doses of some treatment chemicals, such as coagulants and oxidants. This paper presents some data about (i) NOM fractionning by XAD macroporous resins and relationship between UV-absorbance and 13C-NMR, and (ii) study of chlorination of the isolated fractions. Based on these results, one can suppose that aquatic NOM could be soon easily fractionnated and characterized by simples analytical tools. However, many research works are still necessary, particularly on the field of relationships between data of "heavy" analytical tools (13C-NMR, pyrolysis/GC/MS, etc.) and more simple others (UVA/DOC, BDOC, fluorescence etc.).The second paragraph of the paper relates oxidation mechanisms by hydroxyl radicals. In ozonation of drinking water, currently applied in the drinking water treatment, OH radicals production is a necessary consequence, considered as the main action of ozone by some authors. So, disinfection quality, bromate production, BDOC formation, pesticides removal will never be entirely understood as long as hydroxyl radicals participation in ozonation processes will not be really cleared up. To illustrate this purpose, the example of ozonation of a free aminoacid (glycine) by molecular ozone and by OH radicals is shown. Oxidation by "pure" OH radicals, produced by radiolysis, as compared to oxidation by molecular ozone, (at acidic pH in the presence of radical scavengers) shows that two mechanisms are really different. So, some works published some years ago, mixed up the two pathways. Such mechanisms on aminoacids oxidation should allow to understand some more descriptive data on water disinfection and pesticides oxidation.The third example concerns the changes of water quality during ozone/GAC treatment. It is well known that ozonation of naturel waters leads to an enhancement of water biodegradability, in terms of BDOC increase. So, if this BDOC is not removed in the plant, it can be the origin of bacteria regrowth in distribution system. The solutions are either to include, after ozonation step, a biological treatment step on activated carbon (BAC), or to increase chlorination doses applied in final disinfection. The effects of BAC treatment on BDOC and ozonation by-products removals, in the case of the drinking water treatment plant of Sainte-Rose (City of Laval, Quebec, Canada), are described. Finally, taking into account the cost of such a process, the last paragraph of this paper gives some recommandations for conception on BAC treatment.As for general conclusion, some new research topics in water chemistry for the drinking water treatment are enumerated and some ideas about organization and development of applied and fundamental researches in water chermistry for the drinking water treatment, are given