Science.gov

Sample records for additional control experiments

  1. Carbamate deposit control additives

    SciTech Connect

    Honnen, L.R.; Lewis, R.A.

    1980-11-25

    Deposit control additives for internal combustion engines are provided which maintain cleanliness of intake systems without contributing to combustion chamber deposits. The additives are poly(oxyalkylene) carbamates comprising a hydrocarbyloxyterminated poly(Oxyalkylene) chain of 2-5 carbon oxyalkylene units bonded through an oxycarbonyl group to a nitrogen atom of ethylenediamine.

  2. Smog control fuel additives

    SciTech Connect

    Lundby, W.

    1993-06-29

    A method is described of controlling, reducing or eliminating, ozone and related smog resulting from photochemical reactions between ozone and automotive or industrial gases comprising the addition of iodine or compounds of iodine to hydrocarbon-base fuels prior to or during combustion in an amount of about 1 part iodine per 240 to 10,000,000 parts fuel, by weight, to be accomplished by: (a) the addition of these inhibitors during or after the refining or manufacturing process of liquid fuels; (b) the production of these inhibitors for addition into fuel tanks, such as automotive or industrial tanks; or (c) the addition of these inhibitors into combustion chambers of equipment utilizing solid fuels for the purpose of reducing ozone.

  3. Controlled challenge experiment demonstrates substantial additive genetic variation in resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is an etiologic agent of streptococcal disease in tilapia and is one of several Streptococcus spp. that negatively impact worldwide tilapia production. Methods for the prevention and control of S. iniae include vaccines, management strategies, and antibiotics. A complimentary pre...

  4. French and English Together: An "Additive" Experience

    ERIC Educational Resources Information Center

    Wiltshire, Jessica; Harbon, Lesley

    2010-01-01

    This paper examines the nature of the "additive" experience of a bilingual French-English curriculum at Killarney Heights Public School in New South Wales. Predictably, the well-supported "additive" nature of the languages program model elicited positive reactions regarding educational success. The paper also explores issues for administration,…

  5. Combined dispersant fluid loss control additives

    SciTech Connect

    Villa, J. L.; Zeiner, R. N.

    1985-12-31

    Water soluble polymer compositions containing polyacrylic acid and copolymer of itaconic acid and acrylamide are useful as combined dispersant and fluid loss control additives for aqueous drilling fluids, particularly fresh water, gypsum and seawater muds. An example is a polymer composition containing about 80% by weight polyacrylic acid and about 20% by weight copolymer of itaconic acid and acrylamide in its ammonium salt form.

  6. Flight control experiences

    NASA Technical Reports Server (NTRS)

    Musgrave, F. S.

    1977-01-01

    A multidisciplinary medical-management team at mission control provided Skylab crew support by monitoring health, retrieving and compiling experimental data, assisting in the development of flight plans, and by contributing to in-flight procedures and checklists. Real time computers assisted the flight crews in performing medical and other experiments.

  7. Laboratory tests of sludge-control additives

    SciTech Connect

    Tatnall, R.E.

    1996-07-01

    Laboratory {open_quotes}jar{close_quotes} tests compared eleven different fuel oil and diesel fuel sludge-control additives. Factors studied included (1) ability to disperse and prevent buildup of sludge deposits on surfaces, (2) ability to protect steel from corrosion, (3) ability to inhibit growth and proliferation of bacteria, and (4) ability to disperse water. Results varied greatly, and it was found that many commercial products do not do what they claim. It is concluded that fuel retailers should not believe manufacturers` claims for their additive products, but rather should test such products themselves to be sure that the benefits of treatment are real. A simplified form of the procedure used here is proposed as one way for dealers to do such testing.

  8. Fire extinct experiments with water mist by adding additives

    NASA Astrophysics Data System (ADS)

    Yang, Lijun; Zhao, Jianbo

    2011-12-01

    The effects of fire extinguishment with water mist by adding different additives were studied. Tens of chemical substances (including alkali metal salt, dilution agent and surface active agent) were selected as additives due to their different extinct mechanisms. At first the performance of fire extinguishment with single additive was studied, then the effects of the same kinds of chemical substances under the same mass fraction were compared to study their influences on the fire extinguishment factors, including extinct time, fire temperature and oxygen concentration from which the fire extinct mechanism with additives could be concluded. Based on this the experiments were conducted to study the cooperate effect of the complexity of different additives. It indicated the relations between different firefighting mechanisms and different additives were competitive. From a large number of experiments the extinct mechanism with water mist by adding additives was concluded and an optimal compounding additive was selected.

  9. Polymer Photooxidation: An Experiment to Demonstrate the Effect of Additives.

    ERIC Educational Resources Information Center

    Allen, Norman S.; McKellar, John F.

    1979-01-01

    This undergraduate experiment shows that the inclusion of an appropriate additive can have a very marked effect on the physical properties of a polymer. The polymer used is polypropylene and the additives are 2-hydroxy-4-octyloxy-benzophenone and benzophenone. (BB)

  10. Iron-control additives improve acidizing

    SciTech Connect

    Walker, M.; Dill, W. ); Besler, M. )

    1989-07-24

    Iron sulfide and sulfur precipitation in sour wells can be controlled with iron-sequestering agents and sulfide modifiers. Oil production has been routinely increased in sour wells where precipitation of iron sulfide and elemental sulfur has been brought under control. Production increases have been especially noteworthy on wells that had a history of rapid production decline after acid stimulation. Twenty-fold production increases have been recorded. Key to the production increase has been to increase permeability with: Iron chelating agents that control precipitation of iron sulfide. A sulfide modifier that reduces precipitation of solids in the presence of excessive amounts of hydrogen sulfide and prevents precipitation of elemental sulfur.

  11. Quantum Control in Foundational Experiments

    NASA Astrophysics Data System (ADS)

    Céleri, Lucas C.; Gomes, Rafael M.; Ionicioiu, Radu; Jennewein, Thomas; Mann, Robert B.; Terno, Daniel R.

    2014-05-01

    We describe a new class of experiments designed to probe the foundations of quantum mechanics. Using quantum controlling devices, we show how to attain a freedom in temporal ordering of the control and detection of various phenomena. We consider wave-particle duality in the context of quantum-controlled and the entanglement-assisted delayed-choice experiments. Then we discuss a quantum-controlled CHSH experiment and measurement of photon's transversal position and momentum in a single set-up.

  12. CONTROL ROD ALLOY CONTAINING NOBLE METAL ADDITIONS

    DOEpatents

    Anderson, W.K.; Ray, W.E.

    1960-05-01

    Silver-base alloys suitable for use in the fabrication of control rods for neutronic reactors are given. The alloy consists of from 0.5 wt.% to about 1.5 wt.% of a noble metal of platinum, ruthenium, rhodium, osmium, or palladium, up to 10 wt.% of cadmium, from 2 to 20 wt.% indium, the balance being silver.

  13. Silage Microbiology and Its Control through Additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ensiling is a method of preserving a moist crop. A moist crop can support the growth of a wide range of microorganisms, most of which will degrade the nutrient value to livestock. However, ensiling generally controls microbial activity by a combination of an anaerobic environment and a natural ferme...

  14. The TOYSAT structural control experiment

    NASA Technical Reports Server (NTRS)

    Breakwell, J. A.; Chambers, G. J.

    1983-01-01

    The Lockheed TOYSAT experiment is described. The experiment was designed to test hypothesis concerning the application of optimal control theory to flexible spacecraft. The theory is presented, and results described.

  15. Microstructural Control of Additively Manufactured Metallic Materials

    NASA Astrophysics Data System (ADS)

    Collins, P. C.; Brice, D. A.; Samimi, P.; Ghamarian, I.; Fraser, H. L.

    2016-07-01

    In additively manufactured (AM) metallic materials, the fundamental interrelationships that exist between composition, processing, and microstructure govern these materials’ properties and potential improvements or reductions in performance. For example, by using AM, it is possible to achieve highly desirable microstructural features (e.g., highly refined precipitates) that could not otherwise be achieved by using conventional approaches. Simultaneously, opportunities exist to manage macro-level microstructural characteristics such as residual stress, porosity, and texture, the last of which might be desirable. To predictably realize optimal microstructures, it is necessary to establish a framework that integrates processing variables, alloy composition, and the resulting microstructure. Although such a framework is largely lacking for AM metallic materials, the basic scientific components of the framework exist in literature. This review considers these key components and presents them in a manner that highlights key interdependencies that would form an integrated framework to engineer microstructures using AM.

  16. Thermal Control Surfaces Experiment

    NASA Technical Reports Server (NTRS)

    Wilkes, D. R.

    1999-01-01

    This report is the final experiment report for the TCSE and summarizes many years of hardware development and analyses. Also included are analyses presented in a number of TCSE papers that were prepared and given at scientific conferences including three LDEF Post-Retrieval Symposiums.

  17. Estimation of stream nutrient uptake from nutrient addition experiments

    SciTech Connect

    Payn, Robert

    2005-09-01

    Nutrient uptake in streams is often quantified by determining nutrient uptake length. However, current methods for measuring nutrient uptake length are often impractical, expensive, or demonstrably incorrect. We have developed a new method to estimate ambient nutrient uptake lengths using field experiments involving several levels of nutrient addition. Data analysis involves plotting nutrient addition uptake lengths versus added concentration and extrapolating to the negative ambient concentration. This method is relatively easy, inexpensive, and based on sound theoretical development. It is more accurate than the commonly used method involving a single nutrient addition. The utility of the method is supported by field studies directly comparing our new method with isotopic tracer methods for determining uptake lengths of phosphorus, ammonium, and nitrate. Our method also provides parameters for comparing potential nutrient limitation among streams.

  18. Poly(oxyalkylene) aminoether carbamates as deposit control additives

    SciTech Connect

    Plavac, F.

    1987-09-22

    This patent describes deposit control additives to maintain cleanliness in internal combustion engines which are provided. The additives are hydrocarbyl-terminated poly(oxyalkylene) aminohydrocarbyloxyhydrocarbyl carbamates, also referred to as polyether aminoether carbamates.

  19. Effects of an additional dimension in the Young experiment

    SciTech Connect

    Barros, Allan Kardec

    2015-09-15

    The results of the Young experiment can be analyzed either by classical or Quantum Physics. The later one though leads to a more complete interpretation, based on two different patterns that appear when one works either with single or double slits. Here we show that the two patterns can be derived from a single principle, in the context of General Relativity, if one assumes an additional spatial dimension to the four known today. The found equations yield the same results as those in Quantum Mechanics.

  20. One of two rotodip feeders used to control addition of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    One of two rotodip feeders used to control addition of alum solution into the water - Division Avenue Pumping Station & Filtration Plant, West 45th Street and Division Avenue, Cleveland, Cuyahoga County, OH

  1. Control of pyrite addition in coal liquefaction process

    DOEpatents

    Schmid, Bruce K.; Junkin, James E.

    1982-12-21

    Pyrite addition to a coal liquefaction process (22, 26) is controlled (118) in inverse proportion to the calcium content of the feed coal to maximize the C.sub.5 --900.degree. F. (482.degree. C.) liquid yield per unit weight of pyrite added (110). The pyrite addition is controlled in this manner so as to minimize the amount of pyrite used and thus reduce pyrite contribution to the slurry pumping load and disposal problems connected with pyrite produced slag.

  2. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  3. Substrate-controlled Michael additions of chiral ketones to enones.

    PubMed

    Fàbregas, Mireia; Gómez-Palomino, Alejandro; Pellicena, Miquel; Reina, Daniel F; Romea, Pedro; Urpí, Fèlix; Font-Bardia, Mercè

    2014-12-01

    Substrate-controlled Michael additions of the titanium(IV) enolate of lactate-derived ketone 1 to acyclic α,β-unsaturated ketones in the presence of a Lewis acid (TiCl4 or SnCl4) provide the corresponding 2,4-anti-4,5-anti dicarbonyl compounds in good yields and excellent diastereomeric ratios. Likely, the nucleophilic species involved in such additions are bimetallic enolates that may add to enones through cyclic transition states. Finally, further studies indicate that a structurally related β-benzyloxy chiral ketone can also participate in such stereocontrolled conjugate additions. PMID:25423031

  4. Ultrafast amplifier additive timing jitter characterization and control.

    PubMed

    Casanova, Alexis; D'Acremont, Quentin; Santarelli, Giorgio; Dilhaire, Stefan; Courjaud, Antoine

    2016-03-01

    We report on the characterization and long-term compensation of additive timing jitter introduced by a femtosecond ytterbium regenerative amplifier with a 100 kHz repetition rate. A balanced optical cross-correlation technique is used to generate a jitter error signal. This approach is well suited to characterize the additive timing jitter of Yb amplifiers seeded by narrow spectrum Yb oscillators. The balanced optical cross-correlator is in a noncollinear configuration allowing a background free coindence detection. This setup enables the measurement of additive timing jitter from the amplifier, with a noise floor of 300 as integrated from 10 Hz to 10 kHz. The measured additive timing jitter level is about 5 fs, integrated from 0.1 Hz to 10 kHz. The amplifier timing drift characterization and control are performed for more than an hour. PMID:26974074

  5. Software reliability: Additional investigations into modeling with replicated experiments

    NASA Technical Reports Server (NTRS)

    Nagel, P. M.; Schotz, F. M.; Skirvan, J. A.

    1984-01-01

    The effects of programmer experience level, different program usage distributions, and programming languages are explored. All these factors affect performance, and some tentative relational hypotheses are presented. An analytic framework for replicated and non-replicated (traditional) software experiments is presented. A method of obtaining an upper bound on the error rate of the next error is proposed. The method was validated empirically by comparing forecasts with actual data. In all 14 cases the bound exceeded the observed parameter, albeit somewhat conservatively. Two other forecasting methods are proposed and compared to observed results. Although demonstrated relative to this framework that stages are neither independent nor exponentially distributed, empirical estimates show that the exponential assumption is nearly valid for all but the extreme tails of the distribution. Except for the dependence in the stage probabilities, Cox's model approximates to a degree what is being observed.

  6. Emission control devices, fuel additive, and fuel composition changes.

    PubMed Central

    Piver, W T

    1977-01-01

    Emission control devices are installed to meet the exhaust standards of the Clean Air Act for carbon monoxide and hydrocarbons, and it is necessary to know, from a public health point of view, how exhaust emissions may be affected by changes in fuel additives and fuel composition. Since these topics are concerned with developing technologies, the available literature on exhaust emission characteristics and the limited information on health effects, is reviewed. PMID:71235

  7. Emission control devices, fuel additive, and fuel composition changes.

    PubMed

    Piver, W T

    1977-08-01

    Emission control devices are installed to meet the exhaust standards of the Clean Air Act for carbon monoxide and hydrocarbons, and it is necessary to know, from a public health point of view, how exhaust emissions may be affected by changes in fuel additives and fuel composition. Since these topics are concerned with developing technologies, the available literature on exhaust emission characteristics and the limited information on health effects, is reviewed. PMID:71235

  8. Proper use of sludge-control additives in residential heating oil systems

    SciTech Connect

    Tatnall, R.E.

    1995-04-01

    Discussed are various aspects of heating oil `sludge`: How it forms, typical problems it causes, how sludge-control additives work, what should be expected of them, and what happens in a contaminated system when such additives are used. Test results from laboratory and field experiments demonstrate that performance of commercially available additives varies greatly. The concept of `end-of-the-line` treatment is described and compared with bulk fuel treatment. A procedure is described whereby a retailer can test additives himself, and thus determine just what those additives will or will not do for his business. Finally, the economics of an effective treatment program are outlined.

  9. Cytochrome c oxidase: evolution of control via nuclear subunit addition.

    PubMed

    Pierron, Denis; Wildman, Derek E; Hüttemann, Maik; Markondapatnaikuni, Gopi Chand; Aras, Siddhesh; Grossman, Lawrence I

    2012-04-01

    According to theory, present eukaryotic cells originated from a beneficial association between two free-living cells. Due to this endosymbiotic event the pre-eukaryotic cell gained access to oxidative phosphorylation (OXPHOS), which produces more than 15 times as much ATP as glycolysis. Because cellular ATP needs fluctuate and OXPHOS both requires and produces entities that can be toxic for eukaryotic cells such as ROS or NADH, we propose that the success of endosymbiosis has largely depended on the regulation of endosymbiont OXPHOS. Several studies have presented cytochrome c oxidase as a key regulator of OXPHOS; for example, COX is the only complex of mammalian OXPHOS with known tissue-specific isoforms of nuclear encoded subunits. We here discuss current knowledge about the origin of nuclear encoded subunits and the appearance of different isozymes promoted by tissue and cellular environments such as hypoxia. We also review evidence for recent selective pressure acting on COX among vertebrates, particularly in primate lineages, and discuss the unique pattern of co-evolution between the nuclear and mitochondrial genomes. Finally, even though the addition of nuclear encoded subunits was a major event in eukaryotic COX evolution, this does not lead to emergence of a more efficient COX, as might be expected from an anthropocentric point of view, for the "higher" organism possessing large brains and muscles. The main function of these subunits appears to be "only" to control the activity of the mitochondrial subunits. We propose that this control function is an as yet under appreciated key point of evolution. Moreover, the importance of regulating energy supply may have caused the addition of subunits encoded by the nucleus in a process comparable to a "domestication scenario" such that the host tends to control more and more tightly the ancestral activity of COX performed by the mtDNA encoded subunits. PMID:21802404

  10. COMPUTER CONTROL OF BEHAVIORAL EXPERIMENTS.

    ERIC Educational Resources Information Center

    SIEGEL, LOUIS

    THE LINC COMPUTER PROVIDES A PARTICULAR SCHEDULE OF REINFORCEMENT FOR BEHAVIORAL EXPERIMENTS BY EXECUTING A SEQUENCE OF COMPUTER OPERATIONS IN CONJUNCTION WITH A SPECIALLY DESIGNED INTERFACE. THE INTERFACE IS THE MEANS OF COMMUNICATION BETWEEN THE EXPERIMENTAL CHAMBER AND THE COMPUTER. THE PROGRAM AND INTERFACE OF AN EXPERIMENT INVOLVING A PIGEON…

  11. Dynamic telerobotic control of crystallization experiments

    NASA Technical Reports Server (NTRS)

    Ward, K. B.; Zuk, W. M.; Perozzo, M. A.; Walker, M. A.; Birnbaum, G. I.; Kung, W.; Cavaliere, A.; Uffen, D. R.; Scholaert, H.

    1992-01-01

    A dynamically controlled system has been used to prepare crystals of lysozyme. The temperature of the crystallization chamber was adjusted based upon a scintillation signal used to detect the degree of nucleation and incipient crystal growth. Experiments conducted in one country were controlled and monitored by researchers in another, providing the first demonstration of telerobotic control of a protein crystallization experiment.

  12. [Critical of the additive model of the randomized controlled trial].

    PubMed

    Boussageon, Rémy; Gueyffier, François; Bejan-Angoulvant, Theodora; Felden-Dominiak, Géraldine

    2008-01-01

    Randomized, double-blind, placebo-controlled clinical trials are currently the best way to demonstrate the clinical effectiveness of drugs. Its methodology relies on the method of difference (John Stuart Mill), through which the observed difference between two groups (drug vs placebo) can be attributed to the pharmacological effect of the drug being tested. However, this additive model can be questioned in the event of statistical interactions between the pharmacological and the placebo effects. Evidence in different domains has shown that the placebo effect can influence the effect of the active principle. This article evaluates the methodological, clinical and epistemological consequences of this phenomenon. Topics treated include extrapolating results, accounting for heterogeneous results, demonstrating the existence of several factors in the placebo effect, the necessity to take these factors into account for given symptoms or pathologies, as well as the problem of the "specific" effect. PMID:18387273

  13. Characterization and Control of Powder Properties for Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Strondl, A.; Lyckfeldt, O.; Brodin, H.; Ackelid, U.

    2015-03-01

    Powder characterization and handling in powder metallurgy are important issues and the required powder properties will vary between different component manufacturing processes. By understanding and controlling these, the final material properties for different applications can be improved and become more reliable. In this study, the metal powders used in additive manufacturing (AM) in terms of electron beam melting and selective laser melting have been investigated regarding particle size and shape using dynamic image analysis. In parallel, powder flow characteristics have been evaluated with a powder rheometer. Correlations within the results have been found between particle shape and powder flow characteristics that could explain certain effects of the powder processing in the AM processes. The impact, however, in the processing performance as well as in ultimate material properties was found to be limited.

  14. Spinel dissolution via addition of glass forming chemicals. Results of preliminary experiments

    SciTech Connect

    Fox, K. M.; Johnson, F. C.

    2015-11-01

    Increased loading of high level waste in glass can lead to crystallization within the glass. Some crystalline species, such as spinel, have no practical impact on the chemical durability of the glass, and therefore may be acceptable from both a processing and a product performance standpoint. In order to operate a melter with a controlled amount of crystallization, options must be developed for remediating an unacceptable accumulation of crystals. This report describes preliminary experiments designed to evaluate the ability to dissolve spinel crystals in simulated waste glass melts via the addition of glass forming chemicals (GFCs).

  15. The Middeck Active Control Experiment (MACE)

    NASA Technical Reports Server (NTRS)

    Miller, David W.

    1992-01-01

    Viewgraphs on the Middeck Active Control Experiment (MACE) are presented. Topics covered include: program objectives; program features; flight experiment features; current activities; MACE development model lab testing; MACE test article deployed on STS middeck; and development model testing.

  16. The Middeck Active Control Experiment (MACE)

    NASA Astrophysics Data System (ADS)

    Miller, David W.

    Viewgraphs on the Middeck Active Control Experiment (MACE) are presented. Topics covered include: program objectives; program features; flight experiment features; current activities; MACE development model lab testing; MACE test article deployed on STS middeck; and development model testing.

  17. Stories from the trenches: Experiences of Alberta pharmacists in obtaining additional prescribing authority

    PubMed Central

    Charrois, Theresa; Rosenthal, Meagen; Tsuyuki, Ross T.

    2012-01-01

    Background: Pharmacists in Alberta can apply to the Alberta College of Pharmacists in order to obtain the designation of additional prescriber. This designation uniquely allows them to initiate therapy, in addition to other medication-related activities. Our objective was to examine specific experiences of pharmacists regarding the decision to apply and the application itself, and use this information to help inform other pharmacists who are considering additional prescribing. Methods: All pharmacists involved in a randomized, controlled trial being conducted in rural Alberta who had received their additional prescribing authorization (APA) were invited to participate. Pharmacists were contacted via e-mail and asked to respond to questions regarding their experiences in applying for APA. Responses were analyzed using content analysis and the identites of all respondents were kept anonymous. Results: Fourteen pharmacists were invited to participate. Review and examination of the responses revealed 3 main themes: motivation, hurdles and outcomes. Motivation can be understood as the reasons why they applied for their APA. Hurdles include any problems encountered of a personal, environmental or professional nature. Outcomes refer to how this designation has changed their practice. Discussion: Pharmacists had to address many factors that were unexpected during the application process; however, the eventual outcome of obtaining APA was deemed beneficial, both professionally and with regard to patient care. Conclusion: The information shared from these pharmacists will help other pharmacists, regardless of jurisdiction, overcome some of the challenges associated with obtaining advanced prescribing privileges. PMID:23509485

  18. Control of Microthrix parvicella by aluminium salts addition.

    PubMed

    Durban, N; Juzan, L; Krier, J; Gillot, S

    2016-01-01

    Aluminium and iron chloride were added to a biological nutrient removal pilot plant (1,500 population equivalent) treating urban wastewater to investigate the control of Microthrix parvicella bulking and foaming by metallic salts. Monitoring plant performance over two 6-month periods showed a slight impact on the removal efficiencies. Addition of metallic salts (Me; aluminium or aluminium + iron) at a concentration of 41 mmol Me(kg MLSS·d) (MLSS: mixed liquor suspended solids) over 70 days allowed a stabilization of the diluted sludge volume index (DSVI), whereas higher dosages (94 mmol Me(kg MLSS·d) over 35 days or 137 mmol Me(kg MLSS·d) over 14 days induced a significant improvement of the settling conditions. Microscopic observations showed a compaction of biological aggregates with an embedding of filamentous bacteria into the flocs that is not specific to M. parvicella as bacteria from phylum Chloroflexi are embedded too. The quantitative polymerase chain reaction targeting M. parvicella further indicated a possible growth limitation in addition to the flocculation impact at the high dosages of metallic salts investigated. DSVI appeared to be correlated with the relative abundance of M. parvicella. PMID:26819398

  19. Method for controlling a laser additive process using intrinsic illumination

    NASA Astrophysics Data System (ADS)

    Tait, Robert; Cai, Guoshuang; Azer, Magdi; Chen, Xiaobin; Liu, Yong; Harding, Kevin

    2015-05-01

    One form of additive manufacturing is to use a laser to generate a melt pool from powdered metal that is sprayed from a nozzle. The laser net-shape machining system builds the part a layer at a time by following a predetermined path. However, because the path may need to take many turns, maintaining a constant melt pool may not be easy. A straight section may require one speed and power while a sharp bend would over melt the metal at the same settings. This paper describes a process monitoring method that uses the intrinsic IR radiation from the melt pool along with a process model configured to establish target values for the parameters associated with the manufacture or repair. This model is based upon known properties of the metal being used as well as the properties of the laser beam. An adaptive control technique is then employed to control process parameters of the machining system based upon the real-time weld pool measurement. Since the system uses the heat radiant from the melt pool, other previously deposited metal does not confuse the system as only the melted material is seen by the camera.

  20. Field Experiments in Litter Control

    ERIC Educational Resources Information Center

    Finnie, William C.

    1973-01-01

    A series of urban and highway litter experiments in Richmond (Virginia), St. Louis, and Philadelphia indicated well-designed litter cans reduced littering about 15 percent along city streets and nearly 30 percent along highways. Also, the propensity to litter is critically affected by the characteristics of the individual and environmental…

  1. Climate Change: A Controlled Experiment

    SciTech Connect

    Wullschleger, Stan D; Strahl, Maya

    2010-01-01

    Researchers are altering temperature, carbon dioxide and precipitation levels across plots of forests, grasses and crops to see how plant life responds. Warmer temperatures and higher CO{sub 2} concentrations generally result in more leaf growth or crop yield, but these factors can also raise insect infestation and weaken plants ability to ward off pests and disease. Future field experiments that can manipulate all three conditions at once will lead to better models of how long-term climate changes will affect ecosystems worldwide.

  2. Limits of control: the effects of uncontrollability experiences on the efficiency of attentional control.

    PubMed

    Bukowski, Marcin; Asanowicz, Dariusz; Marzecová, Anna; Lupiáñez, Juan

    2015-01-01

    Two experiments were conducted to explore the effects of experiencing uncontrollability on the efficiency of attentional control. The experience of uncontrollability was induced either by unsolvable tasks (Experiment 1) or by tasks in which non-contingent feedback was provided (Experiment 2). A version of the Attentional Network Test-Interactions with an additional measure of vigilance (ANTI-V) was used to evaluate the efficiency of the attentional networks (i.e., alerting, orienting, and executive). Results of both experiments revealed a decreased efficiency of executive attention in participants who experienced stable control deprivation but no negative effects in participants who were able to restore their sense of previously deprived control. Additionally, when participants were asked to perform unsolvable tasks and did not receive feedback (Experiment 1), detrimental effects on the orienting network and vigilance were observed. The motivational and cognitive mechanisms underlying the effects of various uncontrollability experiences on conflict resolution and attentional control are discussed. PMID:25482404

  3. Responses of estuarine nematodes to an increase in nutrient supply: an in situ continuous addition experiment.

    PubMed

    Ferreira, R C; Nascimento-Junior, A B; Santos, P J P; Botter-Carvalho, M L; Pinto, T K

    2015-01-15

    An experiment was carried out on an estuarine mudflat to assess impacts of inorganic nutrients used to fertilize sugar-cane fields on the surrounding aquatic ecosystem, through changes in the nematode community structure. During 118 days, nine quadrats each 4m(2) were sampled six times after the beginning of fertilizer addition. The fertilizer was introduced weekly in six areas, at two different concentrations (low and high doses), and three areas were used as control. The introduction of nutrients modified key nematode community descriptors. In general, the nematodes were negatively affected over the study period. However, Comesa, Metachromadora, Metalinhomoeus, Spirinia and Terschellingia were considered tolerant, and other genera showed different degrees of sensitivity. Nutrient input also affect the availability and quality of food, changing the nematode trophic structure. The use of inorganic fertilizer should be evaluated with care because of the potential for damage to biological communities of coastal aquatic systems. PMID:25499965

  4. Modification of sandy soil hydrophysical environment through bagasse additive under laboratory experiment

    NASA Astrophysics Data System (ADS)

    Abd El-Halim, A. A.; Kumlung, Arunsiri

    2015-01-01

    Until now sandy soils can be considered as one roup having common hydrophysical problems. Therefore, a laboratory experiment was conducted to evaluate the influence of bagasse as an amendment to improve hydrophysical properties of sandy soil, through the determination of bulk density, aggregatesize distribution, total porosity, hydraulic conductivity, pore-space structure and water retention. To fulfil this objective, sandy soils were amended with bagasse at the rate of 0, 0.5, 1, 2, 3 and 4% on the dry weight basis. The study results demonstrated that the addition of bagasse to sandy soils in between 3 to 4% on the dry weight basis led to a significant decrease in bulk density, hydraulic conductivity, and rapid-drainable pores, and increase in the total porosity, water-holding pores, fine capillary pores, water retained at field capacity, wilting point, and soil available water as compared with the control treatment

  5. Additional experiments on flowability improvements of aviation fuels at low temperatures, volume 2

    NASA Technical Reports Server (NTRS)

    Stockemer, F. J.; Deane, R. L.

    1982-01-01

    An investigation was performed to study flow improver additives and scale-model fuel heating systems for use with aviation hydrocarbon fuel at low temperatures. Test were performed in a facility that simulated the heat transfer and temperature profiles anticipated in wing fuel tanks during flight of long-range commercial aircraft. The results are presented of experiments conducted in a test tank simulating a section of an outer wing integral fuel tank approximately full-scale in height, chilled through heat exchange panels bonded to the upper and lower horizontal surfaces. A separate system heated lubricating oil externally by a controllable electric heater, to transfer heat to fuel pumped from the test tank through an oil-to-fuel heat exchanger, and to recirculate the heated fuel back to the test tank.

  6. The Middeck Active Control Experiment (MACE)

    NASA Astrophysics Data System (ADS)

    Miller, David W.

    1991-07-01

    Viewgraphs on the Middeck Active Control Experiment (MACE) are presented. Topics covered include: science program objectives and rationale; science requirements; capturing the essential physics; science development approach; development model hardware; development model test plan; and flight hardware and operations.

  7. The Middeck Active Control Experiment (MACE)

    NASA Technical Reports Server (NTRS)

    Miller, David W.

    1991-01-01

    Viewgraphs on the Middeck Active Control Experiment (MACE) are presented. Topics covered include: science program objectives and rationale; science requirements; capturing the essential physics; science development approach; development model hardware; development model test plan; and flight hardware and operations.

  8. Thermal control surfaces experiment flight system performance

    NASA Technical Reports Server (NTRS)

    Wilkes, Donald R.; Hummer, Leigh L.; Zwiener, James M.

    1991-01-01

    The Thermal Control Surfaces Experiment (TCSE) is the most complex system, other than the LDEF, retrieved after long term space exposure. The TCSE is a microcosm of complex electro-optical payloads being developed and flow by NASA and the DoD including SDI. The objective of TCSE was to determine the effects of the near-Earth orbital environment and the LDEF induced environment on spacecraft thermal control surfaces. The TCSE was a comprehensive experiment that combined in-space measurements with extensive post flight analyses of thermal control surfaces to determine the effects of exposure to the low earth orbit space environment. The TCSE was the first space experiment to measure the optical properties of thermal control surfaces the way they are routinely measured in a lab. The performance of the TCSE confirms that low cost, complex experiment packages can be developed that perform well in space.

  9. MIT Middeck Active Control Experiment (MACE): noncollocated payload pointing control

    NASA Astrophysics Data System (ADS)

    MacMartin, Douglas G.; Miller, David W.

    1993-09-01

    The Middeck Active Control Experiment is a space shuttle flight experiment intended to demonstrate high authority active structural control in zero gravity conditions. The prediction of on-orbit closed-loop dynamics is based on analysis and ground testing. The MACE test article is representative of multiple payload platforms, and includes two 2-axis gimballing payloads connected by a flexible bus. The goal of active control is to maintain pointing accuracy of one payload, while the remaining payload is moving independently. Current control results on the ground test article are presented. Multiple input, multiple output controllers are designed based on high order measurement based models. Linear Quadratic Gaussian controllers yield reasonable performance. At high authority, however, these controllers destabilize the actual structure, due to parametric errors in the control design model. A robust control design procedure is required to yield high performance in the presence of these errors.

  10. The Middeck Active Control Experiment (MACE): Identification for robust control

    NASA Astrophysics Data System (ADS)

    Karlov, Valery I.

    Viewgraphs on identification for robust control for the Middeck Active Control Experiment (MACE) are presented. Topics covered include: identification for robust control; three levels of identification; basic elements of the approach; advantages of 'post-ID' model of uncertainty; advantages of optimization; and practical realization.

  11. The Middeck Active Control Experiment (MACE): Identification for robust control

    NASA Technical Reports Server (NTRS)

    Karlov, Valery I.

    1992-01-01

    Viewgraphs on identification for robust control for the Middeck Active Control Experiment (MACE) are presented. Topics covered include: identification for robust control; three levels of identification; basic elements of the approach; advantages of 'post-ID' model of uncertainty; advantages of optimization; and practical realization.

  12. Additives and method for controlling clathrate hydrates in fluid systems

    DOEpatents

    Sloan, E.D. Jr.; Christiansen, R.L.; Lederhos, J.P.; Long, J.P.; Panchalingam, V.; Du, Y.; Sum, A.K.W.

    1997-06-17

    Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hindrance and/or charge repulsion. Also, polymers having an amide on which a C{sub 1}-C{sub 4} group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness. Polymers having at least some repeating units representative of polymerizing at least one of an oxazoline, an N-substituted acrylamide and an N-vinyl alkyl amide are preferred.

  13. Additives and method for controlling clathrate hydrates in fluid systems

    DOEpatents

    Sloan, Jr., Earle Dendy; Christiansen, Richard Lee; Lederhos, Joseph P.; Long, Jin Ping; Panchalingam, Vaithilingam; Du, Yahe; Sum, Amadeu Kun Wan

    1997-01-01

    Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hinderance and/or charge repulsion. Also, polymers having an amide on which a C.sub.1 -C.sub.4 group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness. Polymers having at least some repeating units representative of polymerizing at least one of an oxazoline, an N-substituted acrylamide and an N-vinyl alkyl amide are preferred.

  14. Microstructure-controllable Laser Additive Manufacturing Process for Metal Products

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Chin; Chuang, Chuan-Sheng; Lin, Ching-Chih; Wu, Chih-Hsien; Lin, De-Yau; Liu, Sung-Ho; Tseng, Wen-Peng; Horng, Ji-Bin

    Controlling the cooling rate of alloy during solidification is the most commonly used method for varying the material microstructure. However, the cooling rate of selective laser melting (SLM) production is constrained by the optimal parameter settings for a dense product. This study proposes a method for forming metal products via the SLM process with electromagnetic vibrations. The electromagnetic vibrations change the solidification process for a given set of SLM parameters, allowing the microstructure to be varied via magnetic flux density. This proposed method can be used for creating microstructure-controllable bio-implant products with complex shapes.

  15. Thermal control surfaces experiment flight system performance

    NASA Technical Reports Server (NTRS)

    Wilkes, Donald R.; Hummer, Leigh L.; Zwiener, James M.

    1992-01-01

    The Thermal Control Surfaces Experiment (TCSE) is the most complex system retrieved after long term space exposure. The TCSE is a microcosm of complex electro-optical payloads being developed and flown. The objective of the TCSE on the LDEF was to determine the effects of the near-Earth orbital environment and the LDEF induced environment on spacecraft thermal control surfaces. The TCSE was a comprehensive experiment that combined in-space measurements with extensive post-flight analyses of thermal control surfaces to determine the effects of exposure to the low Earth orbit space environment. The TCSE was the first space experiment to measure the optical properties of thermal control surfaces the way they are routinely measured in the lab. The performance of the TCSE flight system on the LDEF was excellent.

  16. Fluid loss control additives for oil well cementing compositions

    SciTech Connect

    Crema, S.C.; Kucera, C.H.; Konrad, G.; Hartmann, H.

    1993-07-20

    A cementing composition is described useful in cementing oil, gas and water wells comprising: (a) water; (b) hydraulic cement; and (c) a fluid loss additive in an amount effective to reduce fluid loss, to below 100 cc/30 min said fluid loss additive comprised of a blend of (i) a copolymer of acrylamide and vinyl imidazole, in a weight percent ratio of from about 95:5 to 5:95, acryamide to vinyl imidazole said copolymer having a molecular weight range of from about 10,000 to 3,000,000, and (ii) a copolymer of vinyl pyrrolidone and sodium salt of sulfonate in a weight percent ratio of 80:20 to 20:80; the ratio of copolymer (i) to copolymer (ii) being in the range of 20:80 to 80:20.

  17. Direct laser additive fabrication system with image feedback control

    DOEpatents

    Griffith, Michelle L.; Hofmeister, William H.; Knorovsky, Gerald A.; MacCallum, Danny O.; Schlienger, M. Eric; Smugeresky, John E.

    2002-01-01

    A closed-loop, feedback-controlled direct laser fabrication system is disclosed. The feedback refers to the actual growth conditions obtained by real-time analysis of thermal radiation images. The resulting system can fabricate components with severalfold improvement in dimensional tolerances and surface finish.

  18. Gas Chromatographic Determination of Methyl Salicylate in Rubbing Alcohol: An Experiment Employing Standard Addition.

    ERIC Educational Resources Information Center

    Van Atta, Robert E.; Van Atta, R. Lewis

    1980-01-01

    Provides a gas chromatography experiment that exercises the quantitative technique of standard addition to the analysis for a minor component, methyl salicylate, in a commercial product, "wintergreen rubbing alcohol." (CS)

  19. Fouling control in seawater by on-line acid addition

    SciTech Connect

    Salvago, G.; Taccani, G.; Polimeni, R.; Fumagalli, G.; Picenoni, D.

    1996-11-01

    An experimental plant was set up containing once-through test lines supplied with seawater. The pH level of the seawater was maintained at 6.3 by the acids addition. Heat exchange monitoring equipment and channels exposing different metal specimens were installed on each of the lines. Observation by microscope and EDS analyses were carried out both on the specimen surfaces and on the cross section of the fouling after fracturing in liquid N{sub 2}. The results obtained show that: fouling must not be confused with its effects or simply with its biological components; acidifying seawater can prevent the resistance to heat exchange from increasing without impeding its biological activity. Observation by microscope of the fouling cross sections showed that in untreated seawater the foulings on stainless steel were composed of a continuous compact layer, covered by disorderly clusters. These compact layers were found to contain high quantities of corrosion products of the metals. Elements typical of corrosion products of ferrous materials (Fe, Mn) were also found on Pt, copper alloys and plastic materials. The addition of HCl or H{sub 2}SO{sub 4} to the seawater, to bring it to pH 6.3, reduces the amount of fouling adhering to the surfaces, prevents the development of the continuous layer containing iron and prevents significant increases in heat exchange resistance. The addition of CO{sub 2} can encourage the development of incoherent fibrous material with high Si content and low Fe content which is of little impediment to heat exchange. The addition of lactic acid can encourage both the abnormal development of biomass and the formation of several, separate, layers on stainless steel surfaces.

  20. Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control

    PubMed Central

    Slotwinski, John A; Garboczi, Edward J; Hebenstreit, Keith M

    2014-01-01

    Additive manufacturing techniques can produce complex, high-value metal parts, with potential applications as critical metal components such as those found in aerospace engines and as customized biomedical implants. Material porosity in these parts is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants - since surface-breaking pores allows for better integration with biological tissue. Changes in a part’s porosity during an additive manufacturing build may also be an indication of an undesired change in the build process. Here, we present efforts to develop an ultrasonic sensor for monitoring changes in the porosity in metal parts during fabrication on a metal powder bed fusion system. The development of well-characterized reference samples, measurements of the porosity of these samples with multiple techniques, and correlation of ultrasonic measurements with the degree of porosity are presented. A proposed sensor design, measurement strategy, and future experimental plans on a metal powder bed fusion system are also presented. PMID:26601041

  1. Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control.

    PubMed

    Slotwinski, John A; Garboczi, Edward J; Hebenstreit, Keith M

    2014-01-01

    Additive manufacturing techniques can produce complex, high-value metal parts, with potential applications as critical metal components such as those found in aerospace engines and as customized biomedical implants. Material porosity in these parts is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants - since surface-breaking pores allows for better integration with biological tissue. Changes in a part's porosity during an additive manufacturing build may also be an indication of an undesired change in the build process. Here, we present efforts to develop an ultrasonic sensor for monitoring changes in the porosity in metal parts during fabrication on a metal powder bed fusion system. The development of well-characterized reference samples, measurements of the porosity of these samples with multiple techniques, and correlation of ultrasonic measurements with the degree of porosity are presented. A proposed sensor design, measurement strategy, and future experimental plans on a metal powder bed fusion system are also presented. PMID:26601041

  2. Voices from the Classroom: Experiences of Teachers of Deaf Students with Additional Disabilities

    ERIC Educational Resources Information Center

    Musyoka, Millicent Malinda; Gentry, Mary Anne; Bartlett, James Joseph

    2016-01-01

    The purpose of this research is to investigate experiences of K-12 classroom teachers of deaf students with additional disabilities. Today, more deaf and hard of hearing students are identified as having additional disabilities (Bruce, DiNatale & Ford, 2008; Ewing, 2011; Gallaudet Research Institute, 2011; Jones, Jones & Ewing, 2006;…

  3. Part height control of laser metal additive manufacturing process

    NASA Astrophysics Data System (ADS)

    Pan, Yu-Herng

    Laser Metal Deposition (LMD) has been used to not only make but also repair damaged parts in a layer-by-layer fashion. Parts made in this manner may produce less waste than those made through conventional machining processes. However, a common issue of LMD involves controlling the deposition's layer thickness. Accuracy is important, and as it increases, both the time required to produce the part and the material wasted during the material removal process (e.g., milling, lathe) decrease. The deposition rate is affected by multiple parameters, such as the powder feed rate, laser input power, axis feed rate, material type, and part design, the values of each of which may change during the LMD process. Using a mathematical model to build a generic equation that predicts the deposition's layer thickness is difficult due to these complex parameters. In this thesis, we propose a simple method that utilizes a single device. This device uses a pyrometer to monitor the current build height, thereby allowing the layer thickness to be controlled during the LMD process. This method also helps the LMD system to build parts even with complex parameters and to increase material efficiency.

  4. Condensate kicks pose additional problems for deep well control

    SciTech Connect

    Szczepanski, R.; Edmonds, B.; Yerlett, T.K.; Brown, N.P.; Hamilton, T.A.P.

    1996-06-17

    Modeling condensate and gas kicks in a deep North Sea well helps drillers understand what to expect after prompt kick detection in a straight-forward kick circulation program with competent choke handling. Concerns have been raised in the industry that as a condensate kick is taken and subsequently circulated out of the well, unexpected surface indications may be present. Blowouts, resulting from uncontrolled kicks, could be particularly hazardous for condensate fields as these are often high-pressure, high-temperature operations. A deeper understanding of the differences, and similarities, between gas and condensate kicks has resulted from an investigation by Infochem Computer Services Ltd., funded by the UK Health and Safety Executive (HSE). This study has led to an assessment of the practical significance of any differences for the personnel involved in well control.

  5. Roles of additives and surface control in slurry atomization

    SciTech Connect

    Tsai, S.C.

    1992-01-01

    This project studies the rheology and airblast atomization of micronized coal slurries. Its major objectives are (1) to promote further understanding of the mechanisms and the roles of additives in airblast atomization of coal water slurry (CWS), and (2) to investigate the impacts of coal particle surface properties and interparticle forces on CWS rheology. We have found that the flow behavior index (n) of a suspension (or slurry) is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The interparticle attraction, measured by the Hamaker constant scaled to the thermal energy at 25[degrees]C (A/kT), causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior (n< 1). At a constant particle volume fraction and surface charge density (qualitatively measured by the zeta potential in deionized water), n decreases linearly as A/kT increases. The relative viscosity of the pseudoplastic suspension with respect to that of the suspending liquid is found to be independent of particle density and correlate well with the particle Peclet number which equals the particle diffusional relaxation time multiplied by shear rate. Specifically, the relative viscosities of the pseudoplastic glycerol/water coal slurry and the ethylene glycol/glycerol sand slurry, at same volume fractions as well as similar particle size distributions and liquid viscosities, as functions of the particle Peclet number fall along the same line.

  6. Response of non-added solutes during nutrient addition experiments in streams

    NASA Astrophysics Data System (ADS)

    Rodriguez-Cardona, B.; Wymore, A.; Koenig, L.; Coble, A. A.; McDowell, W. H.

    2015-12-01

    Nutrient addition experiments, such as Tracer Additions for Spiraling Curve Characterization (TASCC), have become widely popular as a means to study nutrient uptake dynamics in stream ecosystems. However, the impact of these additions on ambient concentrations of non-added solutes is often overlooked. TASCC addition experiments are ideal for assessing interactions among solutes because it allows for the characterization of multiple solute concentrations across a broad range of added nutrient concentrations. TASCC additions also require the addition of a conservative tracer (NaCl) to track changes in conductivity during the experimental manipulation. Despite its use as a conservative tracer, chloride (Cl) and its associated sodium (Na) might change the concentrations of other ions and non-added nutrients through ion exchange or other processes. Similarly, additions of biologically active solutes might change the concentrations of other non-added solutes. These methodological issues in nutrient addition experiments have been poorly addressed in the literature. Here we examine the response of non-added solutes to pulse additions (i.e. TASCC) of NaCl plus nitrate (NO3-), ammonium, and phosphate across biomes including temperate and tropical forests, and arctic taiga. Preliminary results demonstrate that non-added solutes respond to changes in the concentration of these added nutrients. For example, concentrations of dissolved organic nitrogen (DON) in suburban headwater streams of New Hampshire both increase and decrease in response to NO3- additions, apparently due to biotic processes. Similarly, cations such as potassium, magnesium, and calcium also increase during TASCC experiments, likely due to cation exchange processes associated with Na addition. The response of non-added solutes to short-term pulses of added nutrients and tracers needs to be carefully assessed to ensure that nutrient uptake metrics are accurate, and to detect biotic interactions that may

  7. Regiodivergent Addition of Phenols to Allylic Oxides: Control of 1,2 and 1,4-Additions for Cyclitol Synthesis**

    PubMed Central

    Moschitto, Matthew J.; Vaccarello, David N.; Lewis, Chad A.

    2015-01-01

    Control of 1,2- and 1,4-addition of substituted phenols to allylic oxides is achieved by intercepting palladium π-allyl complexes. The interconversion of palladium complexes results in the total synthesis of MK7607, cyathiformine B type, streptol, and a new cyclitol. PMID:25533617

  8. A concatenated coded modulation scheme for error control (addition 2)

    NASA Technical Reports Server (NTRS)

    Lin, Shu

    1988-01-01

    A concatenated coded modulation scheme for error control in data communications is described. The scheme is achieved by concatenating a Reed-Solomon outer code and a bandwidth efficient block inner code for M-ary PSK modulation. Error performance of the scheme is analyzed for an AWGN channel. It is shown that extremely high reliability can be attained by using a simple M-ary PSK modulation inner code and a relatively powerful Reed-Solomon outer code. Furthermore, if an inner code of high effective rate is used, the bandwidth expansion required by the scheme due to coding will be greatly reduced. The proposed scheme is particularly effective for high-speed satellite communications for large file transfer where high reliability is required. This paper also presents a simple method for constructing block codes for M-ary PSK modulation. Some short M-ary PSK codes with good minimum squared Euclidean distance are constructed. These codes have trellis structure and hence can be decoded with a soft-decision Viterbi decoding algorithm. Furthermore, some of these codes are phase invariant under multiples of 45 deg rotation.

  9. AFTI/F-16 digital flight control system experience

    NASA Technical Reports Server (NTRS)

    Mackall, D. A.

    1984-01-01

    The Advanced Flighter Technology Integration (AFTI) F-16 program is investigating the integration of emerging technologies into an advanced fighter aircraft. The three major technologies involved are the triplex digital flight control system; decoupled aircraft flight control; and integration of avionics, pilot displays, and flight control. In addition to investigating improvements in fighter performance, the AFTI/F-16 program provides a look at generic problems facing highly integrated, flight-crucial digital controls. An overview of the AFTI/F-16 systems is followed by a summary of flight test experience and recommendations.

  10. The control architecture of the D0 experiment

    SciTech Connect

    J. Fredrick Bartlett et al.

    2002-11-21

    From a controls viewpoint, contemporary high energy physics collider detectors are comparable in complexity to small to medium size accelerators: however, their controls requirements often differ significantly. D0, one of two collider experiments at Fermilab, has recently started a second, extended running period that will continue for the next five years. EPICS [1], an integrated set of software building blocks for implementing a distributed control system, has been adapted to satisfy the slow controls needs of the D0 detector by (1) extending the support for new device types and an additional field bus, (2) by the addition of a global event reporting system that augments the existing EPICS alarm support, and (3) by the addition of a centralized database with supporting tools for defining the configuration of the control system. This paper discusses the control architecture of the current D0 experiment, how the EPICS system was extended to meet the control requirements of a large, high-energy physics detector, and how a formal control system contributes to the management of detector operations.

  11. Sensitivity of Arctic Permafrost Carbon in the Mackenzie River Basin: A substrate addition and incubation experiment

    NASA Astrophysics Data System (ADS)

    Hedgpeth, A.; Beilman, D.; Crow, S. E.

    2014-12-01

    Arctic soil organic matter (SOM) mineralization processes are fundamental to the functioning of high latitude soils in relation to nutrients, stability, and feedbacks to atmospheric CO2 and climate. The arctic permafrost zone covers 25% of the northern hemisphere and contains 1672Pg of soil carbon (C). 88% of this C currently resides in frozen soils that are vulnerable to environmental change. For instance, arctic growing seasons may be lengthened, resulting in an increase in plant productivity and rate of below ground labile C inputs as root exudates. Understanding controls on Arctic SOM dynamics requires recognition that labile C inputs have the potential to significantly affect mineralization of previously stable SOM, also known as 'priming effects'. We conducted a substrate addition incubation experiment to quantify and compare respiration in highly organic (42-48 %C) permafrost soils along a north-south transect in western Canada. Near surface soils (10-20 cm) were collected from permafrost peatland sites in the Mackenzie River Basin from 69.2-62.6°N. The surface soils are fairly young (Δ14C values > -140.0) and can be assumed to contain relatively reactive soil carbon. To assess whether addition of labile substrate alters SOM decomposition dynamics, 4.77-11.75 g of permafrost soil were spiked with 0.5 mg D-glucose g-1 soil and incubated at 5°C. A mass balance approach was used to determin substrate-induced respiration and preliminary results suggest a potential for positive priming in these C-rich soils. Baseline respiration rates from the three sites were similar (0.067-0.263 mg CO2 g-1 soil C) yet show some site-specific trends. The rate at which added substrate was utilized within these soils suggests that other factors besides temperature and soil C content are controlling substrate consumption and its effect on SOM decomposition. Microbial activity can be stimulated by substrate addition to such an extent that SOM turnover is enhanced, suggesting that

  12. Work Experience and Control Orientation in Adolescence.

    ERIC Educational Resources Information Center

    Finch, Michael D.; And Others

    1991-01-01

    Longitudinal data in St. Paul (Minnesota) for 1,001 ninth graders and 962 of them as tenth graders show that part-time work experience and mastery orientation are reciprocally related for adolescents. Youth more internally oriented in grade 9 had less stressful jobs in grade 10. Extrinsic work conditions are sources of control orientation. (SLD)

  13. Distributed control network for optogenetic experiments

    NASA Astrophysics Data System (ADS)

    Kasprowicz, G.; Juszczyk, B.; Mankiewicz, L.

    2014-11-01

    Nowadays optogenetic experiments are constructed to examine social behavioural relations in groups of animals. A novel concept of implantable device with distributed control network and advanced positioning capabilities is proposed. It is based on wireless energy transfer technology, micro-power radio interface and advanced signal processing.

  14. Diffraction experiments with infrared remote controls

    NASA Astrophysics Data System (ADS)

    Kuhn, Jochen; Vogt, Patrik

    2012-02-01

    In this paper we describe an experiment in which radiation emitted by an infrared remote control is passed through a diffraction grating. An image of the diffraction pattern is captured using a cell phone camera and then used to determine the wavelength of the radiation.

  15. PAINT COATINGS: CONTROLLED FIELD AND CHAMBER EXPERIMENTS

    EPA Science Inventory

    To determine the impact of pollution levels on the weathering rates of coatings, laboratory chamber experiments and controlled field exposures at North Carolina and Ohio sites were conducted in such a manner to separate the contributions due to dry deposition, wet deposition, pre...

  16. Middeck Active Control Experiment (MACE), phase A

    NASA Technical Reports Server (NTRS)

    Crawley, Edward F.; Deluis, Javier; Miller, David W.

    1989-01-01

    A rationale to determine which structural experiments are sufficient to verify the design of structures employing Controlled Structures Technology was derived. A survey of proposed NASA missions was undertaken to identify candidate test articles for use in the Middeck Active Control Experiment (MACE). The survey revealed that potential test articles could be classified into one of three roles: development, demonstration, and qualification, depending on the maturity of the technology and the mission the structure must fulfill. A set of criteria was derived that allowed determination of which role a potential test article must fulfill. A review of the capabilities and limitations of the STS middeck was conducted. A reference design for the MACE test article was presented. Computing requirements for running typical closed-loop controllers was determined, and various computer configurations were studied. The various components required to manufacture the structure were identified. A management plan was established for the remainder of the program experiment development, flight and ground systems development, and integration to the carrier. Procedures for configuration control, fiscal control, and safety, reliabilty, and quality assurance were developed.

  17. The Middeck Active Control Experiment (MACE)

    NASA Technical Reports Server (NTRS)

    Miller, David W.; Sepe, Raymond B.; Rey, Daniel; Saarmaa, Erik; Crawley, Edward F.

    1993-01-01

    The Middeck Active Control Experiment (MACE) is a NASA In-Step and Control Structure Interaction (CSI) Office funded Shuttle middeck experiment. The objective is to investigate the extent to which closed-loop behavior of flexible spacecraft in zero-gravity (0-g) can be predicted. This prediction becomes particularly difficult when dynamic behavior during ground testing exhibits extensive suspension and direct gravity coupling. On-orbit system identification and control reconfiguration is investigated to improve performance which would otherwise be limited due to errors in prediction. The program is presently in its preliminary design phase with launch expected in the summer of 1994. The MACE test article consists of three attitude control torque wheels, a two axis gimballing payload, inertial sensors and a flexible support structure. With the acquisition of a second payload, this will represent a multiple payload platform with significant structural flexibility. This paper presents on-going work in the areas of modelling and control of the MACE test article in the zero and one-gravity environments. Finite element models, which include suspension and gravity effects, and measurement models, derived from experimental data, are used as the basis for Linear Quadratic Gaussian controller designs. Finite element based controllers are analytically used to study the differences in closed-loop performance as the test article transitions between the 0-g and 1-g environments. Measurement based controllers are experimentally applied to the MACE test article in the 1-g environment and achieve over an order of magnitude improvement in payload pointing accuracy when disturbed by a broadband torque disturbance. The various aspects of the flight portion of the experiment are also discussed.

  18. The Middeck Active Control Experiment (MACE)

    NASA Astrophysics Data System (ADS)

    Miller, David W.; Sepe, Raymond B.; Rey, Daniel; Saarmaa, Erik; Crawley, Edward F.

    1993-02-01

    The Middeck Active Control Experiment (MACE) is a NASA In-Step and Control Structure Interaction (CSI) Office funded Shuttle middeck experiment. The objective is to investigate the extent to which closed-loop behavior of flexible spacecraft in zero-gravity (0-g) can be predicted. This prediction becomes particularly difficult when dynamic behavior during ground testing exhibits extensive suspension and direct gravity coupling. On-orbit system identification and control reconfiguration is investigated to improve performance which would otherwise be limited due to errors in prediction. The program is presently in its preliminary design phase with launch expected in the summer of 1994. The MACE test article consists of three attitude control torque wheels, a two axis gimballing payload, inertial sensors and a flexible support structure. With the acquisition of a second payload, this will represent a multiple payload platform with significant structural flexibility. This paper presents on-going work in the areas of modelling and control of the MACE test article in the zero and one-gravity environments. Finite element models, which include suspension and gravity effects, and measurement models, derived from experimental data, are used as the basis for Linear Quadratic Gaussian controller designs. Finite element based controllers are analytically used to study the differences in closed-loop performance as the test article transitions between the 0-g and 1-g environments. Measurement based controllers are experimentally applied to the MACE test article in the 1-g environment and achieve over an order of magnitude improvement in payload pointing accuracy when disturbed by a broadband torque disturbance. The various aspects of the flight portion of the experiment are also discussed.

  19. Nitrate removal in stream ecosystems measured by 15N addition experiments: Total uptake

    SciTech Connect

    Mulholland, Patrick J; Hall, Robert; Tank, Jennifer; Sobota, Daniel; O'Brien, Jon; Webster, Jackson; Valett, H. Maurice; Dodds, Walter; Poole, Geoff; Peterson, Chris G.; Meyer, Judy; McDowell, William; Johnson, Sherri; Hamilton, Stephen; Gregory, Stanley; Grimm, Nancy; Dahm, Cliff; Cooper, Lee W; Ashkenas, Linda; Thomas, Suzanne; Sheibley, Rich; Potter, Jody; Niederlehner, Bobbie; Johnson, Laura; Helton, Ashley; Crenshaw, Chelsea; Burgin, Amy; Bernot, Melody; Beaulieu, Jake; Arango, Clay

    2009-01-01

    We measured uptake length of {sup 15}NO{sub 3}{sup -} in 72 streams in eight regions across the United States and Puerto Rico to develop quantitative predictive models on controls of NO{sub 3}{sup -} uptake length. As part of the Lotic Intersite Nitrogen Experiment II project, we chose nine streams in each region corresponding to natural (reference), suburban-urban, and agricultural land uses. Study streams spanned a range of human land use to maximize variation in NO{sub 3}{sup -} concentration, geomorphology, and metabolism. We tested a causal model predicting controls on NO{sub 3}{sup -} uptake length using structural equation modeling. The model included concomitant measurements of ecosystem metabolism, hydraulic parameters, and nitrogen concentration. We compared this structural equation model to multiple regression models which included additional biotic, catchment, and riparian variables. The structural equation model explained 79% of the variation in log uptake length (S{sub Wtot}). Uptake length increased with specific discharge (Q/w) and increasing NO{sub 3}{sup -} concentrations, showing a loss in removal efficiency in streams with high NO{sub 3}{sup -} concentration. Uptake lengths shortened with increasing gross primary production, suggesting autotrophic assimilation dominated NO{sub 3}{sup -} removal. The fraction of catchment area as agriculture and suburban-urban land use weakly predicted NO{sub 3}{sup -} uptake in bivariate regression, and did improve prediction in a set of multiple regression models. Adding land use to the structural equation model showed that land use indirectly affected NO{sub 3}{sup -} uptake lengths via directly increasing both gross primary production and NO{sub 3}{sup -} concentration. Gross primary production shortened S{sub Wtot}, while increasing NO{sub 3}{sup -} lengthened S{sub Wtot} resulting in no net effect of land use on NO{sub 3}{sup -} removal.

  20. Nitrate removal in stream ecosystems measured by 15N addition experiments: Total uptake

    USGS Publications Warehouse

    Hall, R.O., Jr.; Tank, J.L.; Sobota, D.J.; Mulholland, P.J.; O'Brien, J. M.; Dodds, W.K.; Webster, J.R.; Valett, H.M.; Poole, G.C.; Peterson, B.J.; Meyer, J.L.; McDowell, W.H.; Johnson, S.L.; Hamilton, S.K.; Grimm, N. B.; Gregory, S.V.; Dahm, Clifford N.; Cooper, L.W.; Ashkenas, L.R.; Thomas, S.M.; Sheibley, R.W.; Potter, J.D.; Niederlehner, B.R.; Johnson, L.T.; Helton, A.M.; Crenshaw, C.M.; Burgin, A.J.; Bernot, M.J.; Beaulieu, J.J.; Arangob, C.P.

    2009-01-01

    We measured uptake length of 15NO-3 in 72 streams in eight regions across the United States and Puerto Rico to develop quantitative predictive models on controls of NO-3 uptake length. As part of the Lotic Intersite Nitrogen eXperiment II project, we chose nine streams in each region corresponding to natural (reference), suburban-urban, and agricultural land uses. Study streams spanned a range of human land use to maximize variation in NO-3 concentration, geomorphology, and metabolism. We tested a causal model predicting controls on NO-3 uptake length using structural equation modeling. The model included concomitant measurements of ecosystem metabolism, hydraulic parameters, and nitrogen concentration. We compared this structural equation model to multiple regression models which included additional biotic, catchment, and riparian variables. The structural equation model explained 79% of the variation in log uptake length (S Wtot). Uptake length increased with specific discharge (Q/w) and increasing NO-3 concentrations, showing a loss in removal efficiency in streams with high NO-3 concentration. Uptake lengths shortened with increasing gross primary production, suggesting autotrophic assimilation dominated NO-3 removal. The fraction of catchment area as agriculture and suburban-urban land use weakly predicted NO-3 uptake in bivariate regression, and did improve prediction in a set of multiple regression models. Adding land use to the structural equation model showed that land use indirectly affected NO-3 uptake lengths via directly increasing both gross primary production and NO-3 concentration. Gross primary production shortened SWtot, while increasing NO-3 lengthened SWtot resulting in no net effect of land use on NO- 3 removal. ?? 2009.

  1. Remote control of a DC discharge experiment

    NASA Astrophysics Data System (ADS)

    Dominguez, Arturo; Zwicker, A.; Wissel, S. A.; Ross, J.

    2013-10-01

    Glow discharges are an excellent tool to introduce plasmas to the general public, in part, because of their visual nature. In this poster, we present recent developments of the Remote DC Discharge Experiment. This experiment consists of a 36'' long × 3.5'' radius glass tube containing air held at pressures of approximately 30-200mTorr with a variable voltage between the ends which can be set between 0-2000V to create a glow discharge. Surrounding the tube, a set of Helmholtz coils can be controlled to demonstrate the effects of axial magnetic fields on the plasma. While the experiment is located at PPPL, a webcam displays the experiment online. The parameters (voltage, magnetic field and pressure) can be controlled remotely in real-time by opening a URL which shows the streaming video, as well as a set of Labview controls. The interface has been designed to attract users with a wide range of academic backgrounds by presenting different levels of interactivity, including the most advanced level which gives the user the possibility of empirically finding the breakdown voltage as a function of pressure and electrode separation.

  2. Computer controls for the WITCH experiment

    NASA Astrophysics Data System (ADS)

    Tandecki, M.; Beck, D.; Beck, M.; Brand, H.; Breitenfeldt, M.; De Leebeeck, V.; Friedag, P.; Herlert, A.; Kozlov, V.; Mader, J.; Roccia, S.; Soti, G.; Traykov, E.; Van Gorp, S.; Wauters, F.; Weinheimer, Ch.; Zákoucký, D.; Severijns, N.

    2011-02-01

    The WITCH experiment is a medium-scale experimental set-up located at ISOLDE/CERN. It combines a double Penning trap system with a retardation spectrometer for energy measurements of recoil ions from β decay. For a correct operation of such a set-up a whole range of different devices is required. Along with the installation and optimization of the set-up a computer control system was developed to control these devices. The CS-Framework that is developed and maintained at GSI, was chosen as a basis for this control system as it is perfectly suited to handle the distributed nature of a control system.We report here on the required hardware for WITCH, along with the basis of this CS-Framework and the add-ons that were implemented for WITCH.

  3. The impact of quality control in RNA-seq experiments

    NASA Astrophysics Data System (ADS)

    Merino, Gabriela A.; Fresno, Cristóbal; Netto, Frederico; Dias Netto, Emmanuel; Pratto, Laura; Fernández, Elmer A.

    2016-04-01

    High throughput mRNA sample sequencing, known as RNA-seq, is as a powerful approach to detect differentially expressed genes starting from millions of short sequence reads. Although several workflows have been proposed to analyze RNA-seq data, the experiment quality control as a whole is not usually considered, thus potentially biasing the results and/or causing information lost. Experiment quality control refers to the analysis of the experiment as a whole, prior to any analysis. It not only inspects the presence of technical effects, but also if general biological assumptions are fulfilled. In this sense, multivariate approaches are crucial for this task. Here, a multivariate approach for quality control in RNA-seq experiments is proposed. This approach uses simple and yet effective well-known statistical methodologies. In particular, Principal Component Analysis was successfully applied over real data to detect and remove outlier samples. In addition, traditional multivariate exploration tools were applied in order to asses several controls that can help to ensure the results quality. Based on differential expression and functional enrichment analysis, here is demonstrated that the information retrieval is significantly enhanced through experiment quality control. Results show that the proposed multivariate approach increases the information obtained from RNA-seq data after outlier samples removal.

  4. Chemical and biological consequences of using carbon dioxide versus acid additions in ocean acidification experiments

    USGS Publications Warehouse

    Yates, Kimberly K.; DuFore, Christopher M.; Robbins, Lisa L.

    2013-01-01

    Use of different approaches for manipulating seawater chemistry during ocean acidification experiments has confounded comparison of results from various experimental studies. Some of these discrepancies have been attributed to whether addition of acid (such as hydrochloric acid, HCl) or carbon dioxide (CO2) gas has been used to adjust carbonate system parameters. Experimental simulations of carbonate system parameter scenarios for the years 1766, 2007, and 2100 were performed using the carbonate speciation program CO2SYS to demonstrate the variation in seawater chemistry that can result from use of these approaches. Results showed that carbonate system parameters were 3 percent and 8 percent lower than target values in closed-system acid additions, and 1 percent and 5 percent higher in closed-system CO2 additions for the 2007 and 2100 simulations, respectively. Open-system simulations showed that carbonate system parameters can deviate by up to 52 percent to 70 percent from target values in both acid addition and CO2 addition experiments. Results from simulations for the year 2100 were applied to empirically derived equations that relate biogenic calcification to carbonate system parameters for calcifying marine organisms including coccolithophores, corals, and foraminifera. Calculated calcification rates for coccolithophores, corals, and foraminifera differed from rates at target conditions by 0.5 percent to 2.5 percent in closed-system CO2 gas additions, from 0.8 percent to 15 percent in the closed-system acid additions, from 4.8 percent to 94 percent in open-system acid additions, and from 7 percent to 142 percent in open-system CO2 additions.

  5. Additive Routes to Action Learning: Layering Experience Shapes Engagement of the Action Observation Network

    PubMed Central

    Kirsch, Louise P.; Cross, Emily S.

    2015-01-01

    The way in which we perceive others in action is biased by one's prior experience with an observed action. For example, we can have auditory, visual, or motor experience with actions we observe others perform. How action experience via 1, 2, or all 3 of these modalities shapes action perception remains unclear. Here, we combine pre- and post-training functional magnetic resonance imaging measures with a dance training manipulation to address how building experience (from auditory to audiovisual to audiovisual plus motor) with a complex action shapes subsequent action perception. Results indicate that layering experience across these 3 modalities activates a number of sensorimotor cortical regions associated with the action observation network (AON) in such a way that the more modalities through which one experiences an action, the greater the response is within these AON regions during action perception. Moreover, a correlation between left premotor activity and participants' scores for reproducing an action suggests that the better an observer can perform an observed action, the stronger the neural response is. The findings suggest that the number of modalities through which an observer experiences an action impacts AON activity additively, and that premotor cortical activity might serve as an index of embodiment during action observation. PMID:26209850

  6. An additional condition for Bell experiments for accepting local realistic theories

    NASA Astrophysics Data System (ADS)

    Nagata, Koji; Nakamura, Tadao

    2013-12-01

    We assume that one source of two uncorrelated spin-carrying particles emits them in a state, which can be described as a spin-1/2 bipartite pure uncorrelated state. We consider a Bell-Clauser-Horne-Shimony-Holt (Bell-CHSH) experiment with two-orthogonal-settings. We propose an additional condition for the state to be reproducible by the property of local realistic theories. We use the proposed measurement theory in order to construct the additional condition (Nagata and Nakamura in Int J Theor Phys 49:162, 2010). The condition is that local measurement outcome is . Otherwise, such an experiment does not allow for the existence of local realistic theories even in the situation that all Bell-CHSH inequalities hold. Also we derive new set of Bell inequalities when local measurement outcome is.

  7. Practicing Quality Control in a Bioanalytical Experiment

    NASA Astrophysics Data System (ADS)

    Marcos, Juliana; Ríos, Angel; Valcárcel, Miguel

    1995-10-01

    The quality of analytical results frequently requires assessment, which has fostered treatment of this subject in a host of chemical books for students. Accordingly, new experiments need to be devised in order to help students adapt to it. This paper presents a straightforward exercise to demonstrate how quality control and the analysis of variance technique are implemented in practice. The exercise also is attractive because the analyte (chlorophyl) is determined in real samples (plants) that students can collect by themselves. In this way, they can realize the significance of sampling and learn how to do it properly.

  8. Experiment D010: Ion sensing attitude control

    NASA Technical Reports Server (NTRS)

    Sagalyn, R. C.; Smiddy, M.

    1971-01-01

    The feasibility of an attitude control system that uses environmental positive ions and an electrostatic detection system to measure spacecraft pitch and yaw is studied. The secondary objective was to measure the spatial and temporal variations of ambient positively charged particles along the orbital path of the Gemini 10 and 12 spacecrafts. The results proved that the use of a horizon detector in conjunction with pitch and yaw sensors would facilitate complete description of the spacecraft position and attitude. Furthermore, with the addition of a servosystem, the unit could be used as a complete automatic attitude-control system that would be applicable from the lowest satellite altitudes up to at least 10 earth radii. Also, results established that the charge density along the trajectory of the satellite could be determined by transmission of output voltages from the individual electrometers.

  9. Additive Manufacturing, Design, Testing, and Fabrication: A Full Engineering Experience at JSC

    NASA Technical Reports Server (NTRS)

    Zusack, Steven

    2016-01-01

    I worked on several projects this term. While most projects involved additive manufacturing, I was also involved with two design projects, two testing projects, and a fabrication project. The primary mentor for these was Richard Hagen. Secondary mentors were Hai Nguyen, Khadijah Shariff, and fabrication training from James Brown. Overall, my experience at JSC has been successful and what I have learned will continue to help me in my engineering education and profession long after I leave. My 3D printing projects ranged from less than a 1 cubic centimeter to about 1 cubic foot and involved several printers using different printing technologies. It was exciting to become familiar with printing technologies such as industrial grade FDM (Fused Deposition Modeling), the relatively new SLA (Stereolithography), and PolyJet. My primary duty with the FDM printers was to model parts that came in from various sources to print effectively and efficiently. Using methods my mentor taught me and the Stratasys Insight software, I was able to minimize imperfections, hasten build time, improve strength for specific forces (tensile, shear, etc...), and reduce likelihood of a print-failure. Also using FDM, I learned how to repair a part after it was printed. This is done by using a special kind of glue that chemically melts the two faces of plastic parts together to form a fused interface. My first goal with SLA technology was to bring the printer back to operational readiness. In becoming familiar with the Pegasus SLA printer, I researched the leveling, laser settings, and different vats to hold liquid material. With this research, I was successfully able to bring the Pegasus back online and have successfully printed multiple sample parts as well as functional parts. My experience with PolyJet technology has been focused on an understanding of the abilities/limits, costs, and the maintenance for daily use. Still upcoming will be experience with using a composite printer that uses FDM

  10. Experiment-Based Teaching in Advanced Control Engineering

    ERIC Educational Resources Information Center

    Precup, R.-E.; Preitl, S.; Radac, M.-B.; Petriu, E. M.; Dragos, C.-A.; Tar, J. K.

    2011-01-01

    This paper discusses an experiment-based approach to teaching an advanced control engineering syllabus involving controlled plant analysis and modeling, control structures and algorithms, real-time laboratory experiments, and their assessment. These experiments are structured around the representative case of the longitudinal slip control of an…

  11. The Comparative Experiences of Women in Control

    PubMed Central

    Mako, Morgan; Sadikova, Ekaterina; Barnes, Linda; Stone, Abriella; Rosal, Milagros C.; Wiecha, John

    2014-01-01

    The purpose was to characterize participants’ experiences of a diabetes self-management (DSM) education program delivered via a virtual world (VW) versus a face-to-face (F2F) format. Participants included a randomly selected sample of participants who completed the Women in Control study. Four focus groups were conducted with 32 participants. Four researchers coded the data and conducted a qualitative thematic analysis. Four overarching themes were identified. Three domains apply to both VW and F2F formats, including (1) the value of DSM knowledge gained, (2) cultivating DSM attitudes and skills, and (3) the value of peer-derived social support. The fourth domain is labeled positive technological development for DSM (VW condition only). VW and F2F groups both reported mastery of DSM knowledge, attitudes, and skills, and there were no differences in peer-derived social support between groups. The technological aspects of VW participation afforded VW participants a unique sense of personal agency and diabetes self-efficacy not reported by F2F participants. DSM education in a VW is feasible and educational outcomes are similar to a F2F classroom experience. Furthermore, learning DSM skills in a VW offers unique advantages in supporting personal agency for health behavior change. Further research is warranted. PMID:25212580

  12. Additional experiments relative to the shelf life of Li(Si)/FeS2 thermal batteries

    NASA Astrophysics Data System (ADS)

    Searcy, J. Q.; Armijo, J. R.

    1985-02-01

    A continuing effort to develop a new thermal battery technology based on the Li(Si)/FeS2 electrochemical couple is reported. The results relate to the long shelf life requirement for thermal batteries designed by Sandia, and include topics relevant to leakage through the hermetic seal and accelerated aging experiments with materials new to the technology. Conclusions relevant to leakage through the hermetic seal are that the maximum leak rate must not exceed 1.8 x 10(-7) w, where w is the grams of Li(Si) contained by a battery, and that a bomb type leak test can be designed that is adequate for most Li(Si)/FeS2 batteries. Conclusions relevant to long term compatibility of new materials include the following: nickel is not compatible with the iron disulfide in the cathode; the CaSi2 additive used to suppress the initial voltage transient does not react or degrade during accelerated aging experiments, but the use of that material can lead to an increase in the variability of the activated lives, especially for long life batteries; Grafoil current collectors used with the cathode do not degrade in accelerated aging experiments.

  13. Enhanced Attitude Control Experiment for SSTI Lewis Spacecraft

    NASA Technical Reports Server (NTRS)

    Maghami, Peoman G.

    1997-01-01

    The enhanced attitude control system experiment is a technology demonstration experiment on the NASA's small spacecraft technology initiative program's Lewis spacecraft to evaluate advanced attitude control strategies. The purpose of the enhanced attitude control system experiment is to evaluate the feasibility of designing and implementing robust multi-input/multi-output attitude control strategies for enhanced pointing performance of spacecraft to improve the quality of the measurements of the science instruments. Different control design strategies based on modern and robust control theories are being considered for the enhanced attitude control system experiment. This paper describes the experiment as well as the design and synthesis of a mixed H(sub 2)/H(sub infinity) controller for attitude control. The control synthesis uses a nonlinear programming technique to tune the controller parameters and impose robustness and performance constraints. Simulations are carried out to demonstrate the feasibility of the proposed attitude control design strategy. Introduction

  14. Controlled Space Physics Experiments using Laboratory Magnetospheres

    NASA Astrophysics Data System (ADS)

    Mauel, M. E.; Kesner, J.; Garnier, D.

    2013-12-01

    Modern society's reliance on space-based platforms for a variety of economic and geopolitical purposes makes understanding the physics of the magnetosphere and "space weather'' one of the most important applications of plasma science. During the past decade, results from the CTX and LDX laboratory magnetospheres and from the RT-1 device at University of Tokyo, we have developed techniques to explore space physics using controlled experiments in laboratory magnetospheres. This presentation briefly reviews observations from the laboratory magnetospheres at Columbia University and MIT, including adiabatic drift-resonant transport, low-frequency MHD turbulence, and the formation of high-beta plasmas with profiles similar to Earth's inner magnetosphere. First principle validation of ``whole plasma'' space weather models have been completed in relevant magnetic geometry, including the spectrum and dynamics of turbulence successfully modeled with nonlinear bounce-averaged gyrokinetic simulations. Plans to explore Alfvénic dynamics and whistler wave trapping are discussed through the achievement of higher-density plasmas using radio-frequency heating. Photographs of the laboratory magnetospheres located at MIT (top) and Columbia University (bottom).

  15. Loophole-free Bell test using electron spins in diamond: second experiment and additional analysis.

    PubMed

    Hensen, B; Kalb, N; Blok, M S; Dréau, A E; Reiserer, A; Vermeulen, R F L; Schouten, R N; Markham, M; Twitchen, D J; Goodenough, K; Elkouss, D; Wehner, S; Taminiau, T H; Hanson, R

    2016-01-01

    The recently reported violation of a Bell inequality using entangled electronic spins in diamonds (Hensen et al., Nature 526, 682-686) provided the first loophole-free evidence against local-realist theories of nature. Here we report on data from a second Bell experiment using the same experimental setup with minor modifications. We find a violation of the CHSH-Bell inequality of 2.35 ± 0.18, in agreement with the first run, yielding an overall value of S = 2.38 ± 0.14. We calculate the resulting P-values of the second experiment and of the combined Bell tests. We provide an additional analysis of the distribution of settings choices recorded during the two tests, finding that the observed distributions are consistent with uniform settings for both tests. Finally, we analytically study the effect of particular models of random number generator (RNG) imperfection on our hypothesis test. We find that the winning probability per trial in the CHSH game can be bounded knowing only the mean of the RNG bias. This implies that our experimental result is robust for any model underlying the estimated average RNG bias, for random bits produced up to 690 ns too early by the random number generator. PMID:27509823

  16. Loophole-free Bell test using electron spins in diamond: second experiment and additional analysis

    PubMed Central

    Hensen, B.; Kalb, N.; Blok, M. S.; Dréau, A. E.; Reiserer, A.; Vermeulen, R. F. L.; Schouten, R. N.; Markham, M.; Twitchen, D. J.; Goodenough, K.; Elkouss, D.; Wehner, S.; Taminiau, T. H.; Hanson, R.

    2016-01-01

    The recently reported violation of a Bell inequality using entangled electronic spins in diamonds (Hensen et al., Nature 526, 682–686) provided the first loophole-free evidence against local-realist theories of nature. Here we report on data from a second Bell experiment using the same experimental setup with minor modifications. We find a violation of the CHSH-Bell inequality of 2.35 ± 0.18, in agreement with the first run, yielding an overall value of S = 2.38 ± 0.14. We calculate the resulting P-values of the second experiment and of the combined Bell tests. We provide an additional analysis of the distribution of settings choices recorded during the two tests, finding that the observed distributions are consistent with uniform settings for both tests. Finally, we analytically study the effect of particular models of random number generator (RNG) imperfection on our hypothesis test. We find that the winning probability per trial in the CHSH game can be bounded knowing only the mean of the RNG bias. This implies that our experimental result is robust for any model underlying the estimated average RNG bias, for random bits produced up to 690 ns too early by the random number generator. PMID:27509823

  17. An Experiment in Linguistic Synthesis with a Fuzzy Logic Controller

    ERIC Educational Resources Information Center

    Mamdani, E. H.; Assilian, S.

    1975-01-01

    This paper describes an experiment on the "linguistic" synthesis of a controller for a model industrial plant (a steam engine). Fuzzy logic is used to convert heuristic control rules stated by a human operator into an automatic control strategy. (Author)

  18. Augmenting a Waste Glass Mixture Experiment Study with Additional Glass Components and Experimental Runs

    SciTech Connect

    Piepel, Gregory F. ); Cooley, Scott K. ); Peeler, David K.; Vienna, John D. ); Edwards, Tommy B.

    2002-01-01

    A glass composition variation study (CVS) for high-level waste (HLW) stored in Idaho is being statistically designed and performed in phases over several years. The purpose of the CVS is to investigate and model how HLW-glass properties depend on glass composition. The resulting glass property-composition models will be used to develop desirable glass formulations and for other purposes. Phases 1 and 2 of the CVS have been completed and are briefly described. This paper focuses on the CVS Phase 3 experimental design, which was chosen to augment the Phase 1 and 2 data with additional data points, as well as to account for additional glass components not studied in Phases 1 and/or 2. In total, 16 glass components were varied in the Phase 3 experimental design. The paper describes how these Phase 3 experimental design augmentation challenges were addressed using the previous data, preliminary property-composition models, and statistical mixture experiment and optimal experimental design methods and software.

  19. The additive effect on suicidality of family history of suicidal behavior and early traumatic experiences.

    PubMed

    Lopez-Castroman, J; Guillaume, S; Olié, E; Jaussent, I; Baca-García, E; Courtet, P

    2015-01-01

    Family history of suicidal behavior and personal history of childhood abuse are reported risk factors for suicide attempts and suicide completion. We aim to quantify the additive effect of family history of suicidal behavior and different subtypes of childhood abuse on suicidal behavior. We examined a sample of 496 suicide attempters, comparing individuals with family history of suicidal behavior and personal history of childhood (physical or sexual) abuse, individuals with family history of suicidal behavior only, individuals with history of early traumatic experiences only, and individuals with none of these two risk factors with regards to suicidal features. An additive effect was found for the age at the first attempt in suicide attempters with both family history of suicidal behavior and either physical or sexual abuse. No significant interactions were found between family history of suicidal behavior and childhood trauma in relation to any characteristics of suicidal behavior. Subjects presenting family history of suicidal behavior and childhood abuse attempt suicide earlier in life than subjects with just one or none of them, particularly if they were sexually abused. Other suicidality indexes were only partially or not associated with this combination of risk factors. A careful assessment of patients with both family history of suicidal behavior and childhood abuse could help to prevent future suicide attempts, particularly in young people. PMID:25259671

  20. CMS Pixel Telescope Addition to T-980 Bent Crystal Collimation Experiment at the Tevatron

    SciTech Connect

    Rivera, Ryan; Annala, Jerry; Johnson, Todd; Kwan, Simon; Lundberg, Carl; Still, Dean; Prosser, Alan; Uplegger, Lorenzo; Zagel, Jim; Zvodaya, Viktoriya; /Fermilab

    2011-09-14

    An enhancement to the T-980 bent crystal collimation experiment at the Tevatron has been completed. The enhancement was the installation of a pixel telescope inside the vacuum-sealed beam pipe of the Tevatron. The telescope is comprised of six CMS PSI46 pixel plaquettes, arranged as three stations of horizontal and vertical planes, with the CAPTAN system for data acquisition and control. The purpose of the pixel telescope is to measure beam profiles produced by bent crystals under various conditions. The telescope electronics inside the beam pipe initially were not adequately shielded from the image current of the passing beams. A new shielding approach was devised and installed, which resolved the problem. The noise issues encountered and the mitigating techniques are presented herein, as well as some preliminary results from the telescope.

  1. Automated Microwave Frequency Control in Dynamic Nuclear Polarization Experiments

    NASA Astrophysics Data System (ADS)

    Scott, Ethan; Johnson, Ian; Keller, Dustin; Solid Polarized Target Group Team

    2016-03-01

    To achieve highest polarization levels in dynamic nuclear polarization (DNP) experiments, target materials must be subjected to microwave irradiation at a particular frequency determined by the difference in the nuclear Larmor and electron paramagnetic resonance (EPR) frequencies. However, this resonant frequency is variable; it drifts as a result of radiation damage. Manually adjusting the frequency to accommodate for this fluctuation can be difficult, and improper adjustments negatively impact the polarization. In response to this problem, a controller has been developed which automates the process of seeking and maintaining optimal frequency. The creation of such a controller has necessitated research into the correlation between microwave frequency and corresponding polarization growth or decay rates in DNP experiments. Knowledge gained from the research of this unique relationship has additionally lead to the development of a Monte-Carlo simulation which accurately models polarization as a function of frequency and a number of other parameters. The simulation and controller continue to be refined, however, recent DNP experimentation has confirmed the controller's effectiveness.

  2. Highly Diastereoselective Chelation-controlled Additions to α-Silyloxy Ketones

    PubMed Central

    Stanton, Gretchen R.; Koz, Gamze

    2011-01-01

    The polar Felkin-Anh, Cornforth, and Cram-chelation models predict that the addition of organometallic reagents to silyl–protected α–hydroxy ketones proceeds via a non-chelation pathway to give anti-diol addition products. This prediction has held true for the vast majority of additions reported in the literature and few methods for chelation-controlled additions of organometallic reagents to silyl–protected α–hydroxy ketones have been introduced. Herein, we present a general and highly diastereoselective method for the addition of dialkylzincs and (E)-di-, (E)-tri- and (Z)-disubstituted vinylzinc reagents to α-silyloxy ketones using alkyl zinc halide Lewis acids, RZnX, to give chelation-controlled products (dr ≥18:1). The compatibility of organozinc reagents with other functional groups makes this method potentially very useful in complex molecule synthesis. PMID:21534530

  3. Effects of biochar addition to soil on nitrogen fluxes in a winter wheat lysimeter experiment

    NASA Astrophysics Data System (ADS)

    Hüppi, Roman; Leifeld, Jens; Neftel, Albrecht; Conen, Franz; Six, Johan

    2014-05-01

    Biochar is a carbon-rich, porous residue from pyrolysis of biomass that potentially increases crop yields by reducing losses of nitrogen from soils and/or enhancing the uptake of applied fertiliser by the crops. Previous research is scarce about biochar's ability to increase wheat yields in temperate soils or how it changes nitrogen dynamics in the field. In a lysimeter system with two different soils (sandy/silt loam) nitrogen fluxes were traced by isotopic 15N enriched fertiliser to identify changes in nitrous oxide emissions, leaching and plant uptake after biochar addition. 20t/ha woodchip-waste biochar (pH=13) was applied to these soils in four lysimeters per soil type; the same number of lysimeters served as a control. The soils were cropped with winter wheat during the season 2012/2013. 170 kg-N/ha ammonium nitrate fertiliser with 10% 15N was applied in 3 events during the growing season and 15N concentrations where measured at different points in time in plant, soil, leachate and emitted nitrous oxide. After one year the lysimeter system showed no difference between biochar and control treatment in grain- and straw yield or nitrogen uptake. However biochar did reduce nitrous oxide emissions in the silt loam and losses of nitrate leaching in sandy loam. This study indicates potential reduction of nitrogen loss from cropland soil by biochar application but could not confirm increased yields in an intensive wheat production system.

  4. Physics experiments with Nintendo Wii controllers

    NASA Astrophysics Data System (ADS)

    Wheeler, Martyn D.

    2011-01-01

    This article provides a detailed description of the use of Nintendo Wii game controllers in physics demonstrations. The main features of the controller relevant to physics are outlined and the procedure for communicating with a PC is described. A piece of software written by the author is applied to gathering data from a controller suspended from a spring undergoing simple harmonic motion, a pair of controllers mounted on colliding gliders on a linear air track, and a person jumping from a balance board.

  5. Physics Experiments with Nintendo Wii Controllers

    ERIC Educational Resources Information Center

    Wheeler, Martyn D.

    2011-01-01

    This article provides a detailed description of the use of Nintendo Wii game controllers in physics demonstrations. The main features of the controller relevant to physics are outlined and the procedure for communicating with a PC is described. A piece of software written by the author is applied to gathering data from a controller suspended from…

  6. An experiment in software reliability: Additional analyses using data from automated replications

    NASA Technical Reports Server (NTRS)

    Dunham, Janet R.; Lauterbach, Linda A.

    1988-01-01

    A study undertaken to collect software error data of laboratory quality for use in the development of credible methods for predicting the reliability of software used in life-critical applications is summarized. The software error data reported were acquired through automated repetitive run testing of three independent implementations of a launch interceptor condition module of a radar tracking problem. The results are based on 100 test applications to accumulate a sufficient sample size for error rate estimation. The data collected is used to confirm the results of two Boeing studies reported in NASA-CR-165836 Software Reliability: Repetitive Run Experimentation and Modeling, and NASA-CR-172378 Software Reliability: Additional Investigations into Modeling With Replicated Experiments, respectively. That is, the results confirm the log-linear pattern of software error rates and reject the hypothesis of equal error rates per individual fault. This rejection casts doubt on the assumption that the program's failure rate is a constant multiple of the number of residual bugs; an assumption which underlies some of the current models of software reliability. data raises new questions concerning the phenomenon of interacting faults.

  7. Additions and Improvements to the FLASH Code for Simulating High Energy Density Physics Experiments

    NASA Astrophysics Data System (ADS)

    Lamb, D. Q.; Daley, C.; Dubey, A.; Fatenejad, M.; Flocke, N.; Graziani, C.; Lee, D.; Tzeferacos, P.; Weide, K.

    2015-11-01

    FLASH is an open source, finite-volume Eulerian, spatially adaptive radiation hydrodynamics and magnetohydrodynamics code that incorporates capabilities for a broad range of physical processes, performs well on a wide range of computer architectures, and has a broad user base. Extensive capabilities have been added to FLASH to make it an open toolset for the academic high energy density physics (HEDP) community. We summarize these capabilities, with particular emphasis on recent additions and improvements. These include advancements in the optical ray tracing laser package, with methods such as bi-cubic 2D and tri-cubic 3D interpolation of electron number density, adaptive stepping and 2nd-, 3rd-, and 4th-order Runge-Kutta integration methods. Moreover, we showcase the simulated magnetic field diagnostic capabilities of the code, including induction coils, Faraday rotation, and proton radiography. We also describe several collaborations with the National Laboratories and the academic community in which FLASH has been used to simulate HEDP experiments. This work was supported in part at the University of Chicago by the DOE NNSA ASC through the Argonne Institute for Computing in Science under field work proposal 57789; and the NSF under grant PHY-0903997.

  8. Experimenting from a distance—remotely controlled laboratory (RCL)

    NASA Astrophysics Data System (ADS)

    Gröber, Sebastian; Vetter, Martin; Eckert, Bodo; Jodl, Hans-Jörg

    2007-05-01

    The use of computers and multimedia, as well as the World Wide Web and new communication technologies, allows new forms of teaching and learning such as distance learning, blended learning, use of virtual libraries and many more. The herewith discussed remotely controlled laboratory (RCL) project shall offer an additional contribution. The basic idea is for a user to connect via the Internet with a computer from place A to a real experiment carried out in place B. An overview of our technical and didactical developments as well as an outlook on future plans is presented. Currently, about ten RCLs have been implemented. The essential characteristics of an RCL are the intuitive use and interactivity (operating the technical parameters), the possibility of different points of view of the ongoing experiment thanks to web cams and the quickest possible transfer of the data measured by the user. A reasonable use of sensibly chosen real experiments as remote labs allows a new form of homework and exercises, as well as project work and the execution of experiments, which usually would be a teacher's prerogative only.

  9. Nitrate removal in stream ecosystems measured by 15N addition experiments: 2. Denitrification

    SciTech Connect

    Mulholland, Patrick J; Hall, Robert; Sobota, Daniel; Dodds, Walter; Findlay, Stuart; Grimm, Nancy; Hamilton, Stephen; McDowell, William; O'Brien, Jon; Tank, Jennifer; Ashkenas, Linda; Cooper, Lee W; Dahm, Cliff; Gregory, Stanley; Johnson, Sherri; Meyer, Judy; Peterson, Bruce; Poole, Geoff; Valett, H. Maurice; Webster, Jackson; Arango, Clay; Beaulieu, Jake; Bernot, Melody; Burgin, Amy; Crenshaw, Chelsea; Helton, Ashley; Johnson, Laura; Niederlehner, Bobbie; Potter, Jody; Sheibley, Rich; Thomas, Suzanne

    2009-01-01

    We measured denitrification rates using a field {sup 15}N-NO{sub 3}{sup -} tracer-addition approach in a large, cross-site study of nitrate uptake in reference, agricultural, and suburban-urban streams. We measured denitrification rates in 49 of 72 streams studied. Uptake length due to denitrification (S{sub Wden}) ranged from 89 m to 184 km (median of 9050 m) and there were no significant differences among regions or land-use categories, likely because of the wide range of conditions within each region and land use. N{sub 2} production rates far exceeded N{sub 2}O production rates in all streams. The fraction of total NO{sub 3}{sup -} removal from water due to denitrification ranged from 0.5% to 100% among streams (median of 16%), and was related to NH{sub 4}{sup +} concentration and ecosystem respiration rate (ER). Multivariate approaches showed that the most important factors controlling S{sub Wden} were specific discharge (discharge/width) and NO{sub 3}{sup -} concentration (positive effects), and ER and transient storage zones (negative effects). The relationship between areal denitrification rate (U{sub den}) and NO{sub 3}{sup -} concentration indicated a partial saturation effect. A power function with an exponent of 0.5 described this relationship better than a Michaelis-Menten equation. Although U{sub den} increased with increasing NO{sub 3}{sup -} concentration, the efficiency of NO{sub 3}{sup -} removal from water via denitrification declined, resulting in a smaller proportion of streamwater NO{sub 3}{sup -} load removed over a given length of stream. Regional differences in stream denitrification rates were small relative to the proximate factors of NO{sub 3}{sup -} concentration and ecosystem respiration rate, and land use was an important but indirect control on denitrification in streams, primarily via its effect on NO{sub 3}{sup -} concentration.

  10. Nitrate removal in stream ecosystems measured by 15N addition experiments: Denitrification

    USGS Publications Warehouse

    Mulholland, P.J.; Hall, R.O., Jr.; Sobota, D.J.; Dodds, W.K.; Findlay, S.E.G.; Grimm, N. B.; Hamilton, S.K.; McDowell, W.H.; O'Brien, J. M.; Tank, J.L.; Ashkenas, L.R.; Cooper, L.W.; Dahm, Clifford N.; Gregory, S.V.; Johnson, S.L.; Meyer, J.L.; Peterson, B.J.; Poole, G.C.; Valett, H.M.; Webster, J.R.; Arango, C.P.; Beaulieu, J.J.; Bernot, M.J.; Burgin, A.J.; Crenshaw, C.L.; Helton, A.M.; Johnson, L.T.; Niederlehner, B.R.; Potter, J.D.; Sheibley, R.W.; Thomasn, S.M.

    2009-01-01

    We measured denitrification rates using a field 15N-NO- 3 tracer-addition approach in a large, cross-site study of nitrate uptake in reference, agricultural, and suburban-urban streams. We measured denitrification rates in 49 of 72 streams studied. Uptake length due to denitrification (SWden) ranged from 89 m to 184 km (median of 9050 m) and there were no significant differences among regions or land-use categories, likely because of the wide range of conditions within each region and land use. N2 production rates far exceeded N2O production rates in all streams. The fraction of total NO-3 removal from water due to denitrification ranged from 0.5% to 100% among streams (median of 16%), and was related to NHz 4 concentration and ecosystem respiration rate (ER). Multivariate approaches showed that the most important factors controlling SWden were specific discharge (discharge / width) and NO-3 concentration (positive effects), and ER and transient storage zones (negative effects). The relationship between areal denitrification rate (Uden) and NO- 3 concentration indicated a partial saturation effect. A power function with an exponent of 0.5 described this relationship better than a Michaelis-Menten equation. Although Uden increased with increasing NO- 3 concentration, the efficiency of NO-3 removal from water via denitrification declined, resulting in a smaller proportion of streamwater NO-3 load removed over a given length of stream. Regional differences in stream denitrification rates were small relative to the proximate factors of NO-3 concentration and ecosystem respiration rate, and land use was an important but indirect control on denitrification in streams, primarily via its effect on NO-3 concentration. ?? 2009.

  11. Fluorescence measurements of the thermal control experiments coatings on LDEF S0069 and A0114

    NASA Technical Reports Server (NTRS)

    Zwiener, J. M.; Mell, R. J.; Peters, P. N.; Gregory, J. C.; Wilkes, D. R.; Miller, E. R.

    1993-01-01

    Fluorescence measurements were made on the thermal control coatings from the Long Duration Experiment Facility (LDEF) S0069, Thermal Control Surfaces Experiment (TCSE); and the A0114, Interaction of Atomic Oxygen with Material Surfaces in Low Earth orbit. Fluorescence was observed in two types of thermal control coatings and is attributed to pigments or binders. In addition, fluorescence measurement on the silver Teflon from the front cover of TCSE led to confirmation of damage (cracking) to the metal layers during application.

  12. Antagonistic control of a dual-input mammalian gene switch by food additives

    PubMed Central

    Xie, Mingqi; Ye, Haifeng; Hamri, Ghislaine Charpin-El; Fussenegger, Martin

    2014-01-01

    Synthetic biology has significantly advanced the design of mammalian trigger-inducible transgene-control devices that are able to programme complex cellular behaviour. Fruit-based benzoate derivatives licensed as food additives, such as flavours (e.g. vanillate) and preservatives (e.g. benzoate), are a particularly attractive class of trigger compounds for orthogonal mammalian transgene control devices because of their innocuousness, physiological compatibility and simple oral administration. Capitalizing on the genetic componentry of the soil bacterium Comamonas testosteroni, which has evolved to catabolize a variety of aromatic compounds, we have designed different mammalian gene expression systems that could be induced and repressed by the food additives benzoate and vanillate. When implanting designer cells engineered for gene switch-driven expression of the human placental secreted alkaline phosphatase (SEAP) into mice, blood SEAP levels of treated animals directly correlated with a benzoate-enriched drinking programme. Additionally, the benzoate-/vanillate-responsive device was compatible with other transgene control systems and could be assembled into higher-order control networks providing expression dynamics reminiscent of a lap-timing stopwatch. Designer gene switches using licensed food additives as trigger compounds to achieve antagonistic dual-input expression profiles and provide novel control topologies and regulation dynamics may advance future gene- and cell-based therapies. PMID:25030908

  13. Automated microbial metabolism laboratory. [design of advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into test chambers

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The design and rationale of an advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into each of four test chambers are outlined. The feasibility for multiple addition tests was established and various details of the methodology were studied. The four chamber battery of tests include: (1) determination of the effect of various atmospheric gases and selection of that gas which produces an optimum response; (2) determination of the effect of incubation temperature and selection of the optimum temperature for performing Martian biochemical tests; (3) sterile soil is dosed with a battery of C-14 labeled substrates and subjected to experimental temperature range; and (4) determination of the possible inhibitory effects of water on Martian organisms is performed initially by dosing with 0.01 ml and 0.5 ml of medium, respectively. A series of specifically labeled substrates are then added to obtain patterns in metabolic 14CO2 (C-14)O2 evolution.

  14. Control of terahertz emission in photoconductive antennas through an additional optical continuous wave.

    PubMed

    Bockelt, A; Palací, J; Vidal, B

    2013-08-15

    The manipulation of the operating conditions of photoconductive antennas by means of an additional continuous wave (CW) is reported. It is used to control a fiber-based terahertz (THz) time-domain-spectroscopy system at telecom wavelengths. The injection of an optical CW into the transmitter allows the control of the THz amplitude without causing major degradation to the system performance. This, for instance, can be exploited to perform modulation of the THz signal. PMID:24104665

  15. Addition of Titanium Oxide Inclusions into Liquid Steel to Control Nonmetallic Inclusions

    NASA Astrophysics Data System (ADS)

    Kiviö, Miia; Holappa, Lauri

    2012-04-01

    Titanium oxide inclusions in steel are well known to inhibit grain growth and act as nucleation sites for acicular ferrite because of absorbing manganese from the surrounding steel resulting in a manganese depleted zone around the inclusion. In this article, the inclusions resulting from TiO2 additions to low-alloyed C-Mn-Cr steel were studied. Different types of TiO2 containing materials were added to liquid steel before or during casting to get small titanium-oxide-rich inclusions in steel. The main goals were to find out what happens to TiO2 in liquid steel after addition and during cooling and to study further what type of inclusions are formed in the steel as a result of the TiO2 addition. Based on the thermodynamic calculations and the results of scanning electron microscope (SEM)-energy dispersive spectroscope (EDS) and SEM-electron backscatter diffraction (EBSD) analysis, TiO2 is first reduced to Ti3O5 in liquid steel at high temperatures and then to Ti2O3 during cooling at around 1573 K (1300 °C). Both reactions liberate oxygen, which reacts with Ti, Mn, and Al forming complex Ti2O3-rich inclusions. The results also show that TiO2 additions result in more TiOx + MnO inclusions compared with experiments with Ti addition and that the absolute amount of manganese present in the inclusions is much higher in experiments with TiO2 addition than in experiments with Ti additions.

  16. Diesel engine experiments with oxygen enrichment, water addition and lower-grade fuel

    SciTech Connect

    Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J. ); Schaus, J.E. )

    1990-01-01

    The concept of oxygen enriched air applied to reciprocating engines is getting renewed attention in the context of the progress made in the enrichment methods and the tougher emissions regulations imposed on diesel and gasoline engines. An experimental project was completed in which a direct injection diesel engine was tested with intake oxygen levels of 21% -- 35%. Since an earlier study indicated that it is necessary to use a cheaper fuel to make the concept economically attractive, a less refined fuel was included in the test series. Since a major objection to the use of oxygen enriched combustion air had been the increase in NO{sub x} emissions, a method must be found to reduce NO{sub x}. Introduction of water into the engine combustion process was included in the tests for this purpose. Fuel emulsification with water was the means used here even though other methods could also be used. The teat data indicated a large increase in engine power density, slight improvement in thermal efficiency, significant reductions in smoke and particulate emissions and NO{sub x} emissions controllable with the addition of water. 15 refs., 10 figs., 2 tabs.

  17. Flexible manipulator control experiments and analysis

    NASA Technical Reports Server (NTRS)

    Yurkovich, S.; Ozguner, U.; Tzes, A.; Kotnik, P. T.

    1987-01-01

    Modeling and control design for flexible manipulators, both from an experimental and analytical viewpoint, are described. From the application perspective, an ongoing effort within the laboratory environment at the Ohio State University, where experimentation on a single link flexible arm is underway is described. Several unique features of this study are described here. First, the manipulator arm is slewed by a direct drive dc motor and has a rigid counterbalance appendage. Current experimentation is from two viewpoints: (1) rigid body slewing and vibration control via actuation with the hub motor, and (2) vibration suppression through the use of structure-mounted proof-mass actuation at the tip. Such an application to manipulator control is of interest particularly in design of space-based telerobotic control systems, but has received little attention to date. From an analytical viewpoint, parameter estimation techniques within the closed-loop for self-tuning adaptive control approaches are discussed. Also introduced is a control approach based on output feedback and frequency weighting to counteract effects of spillover in reduced-order model design. A model of the flexible manipulator based on experimental measurements is evaluated for such estimation and control approaches.

  18. VNEC - A Virtual Network Experiment Controller

    NASA Astrophysics Data System (ADS)

    Gagnon, François; Dej, Tomas; Esfandiari, Babak

    This paper presents VNEC, a tool to specify and execute network experiments in a virtual environment. The user first formulates the network topology and then provides the tasks that should be performed by the computers together with their execution. Next, VNEC initializes the environment by powering up and configuring the virtual machines to match the desired network topology. Finally, commands are dispatched to the right virtual machines in the specified order. VNEC provides an environment for several types of research experiments such as virus propagation patterns and reactions of different targets against a given attack.

  19. 40 CFR 52.1163 - Additional control measures for East Boston.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Boston. 52.1163 Section 52.1163 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Additional control measures for East Boston. (a) On or before December 31, 1975, the Governor, the Mayor of the City of Boston, the Chairman of the Massachusetts Bay Transportation Authority, the Chairman...

  20. 40 CFR 52.1163 - Additional control measures for East Boston.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Boston. 52.1163 Section 52.1163 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Additional control measures for East Boston. (a) On or before December 31, 1975, the Governor, the Mayor of the City of Boston, the Chairman of the Massachusetts Bay Transportation Authority, the Chairman...

  1. 40 CFR 52.1163 - Additional control measures for East Boston.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Boston. 52.1163 Section 52.1163 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Additional control measures for East Boston. (a) On or before December 31, 1975, the Governor, the Mayor of the City of Boston, the Chairman of the Massachusetts Bay Transportation Authority, the Chairman...

  2. 40 CFR 52.1163 - Additional control measures for East Boston.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Boston. 52.1163 Section 52.1163 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Additional control measures for East Boston. (a) On or before December 31, 1975, the Governor, the Mayor of the City of Boston, the Chairman of the Massachusetts Bay Transportation Authority, the Chairman...

  3. Chill water additive controls transfer of Salmonella and Campylobacter by improved chlorine efficacy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In earlier work, we showed that a proprietary additive (T-128) maintains chlorine activity in the presence of organic material such as broiler parts. T-128 improves the efficacy of chlorine to control transfer of Campylobacter and Salmonella from inoculated wings to un-inoculated wings during immer...

  4. Description of the Spacecraft Control Laboratory Experiment (SCOLE) facility

    NASA Technical Reports Server (NTRS)

    Williams, Jeffrey P.; Rallo, Rosemary A.

    1987-01-01

    A laboratory facility for the study of control laws for large flexible spacecraft is described. The facility fulfills the requirements of the Spacecraft Control Laboratory Experiment (SCOLE) design challenge for a laboratory experiment, which will allow slew maneuvers and pointing operations. The structural apparatus is described in detail sufficient for modelling purposes. The sensor and actuator types and characteristics are described so that identification and control algorithms may be designed. The control implementation computer and real-time subroutines are also described.

  5. Description of the Spacecraft Control Laboratory Experiment (SCOLE) facility

    NASA Technical Reports Server (NTRS)

    Williams, Jeffrey P.; Rallo, Rosemary A.

    1987-01-01

    A laboratory facility for the study of control laws for large flexible spacecraft is described. The facility fulfills the requirements of the Spacecraft Control Laboratory Experiment (SCOLE) design challenge for laboratory experiments, which will allow slew maneuvers and pointing operations. The structural apparatus is described in detail sufficient for modelling purposes. The sensor and actuator types and characteristics are described so that identification and control algorithms may be designed. The control implementation computer and real-time subroutines are also described.

  6. Executive Control and the Experience of Regret

    ERIC Educational Resources Information Center

    Burns, Patrick; Riggs, Kevin J.; Beck, Sarah R.

    2012-01-01

    The experience of regret rests on a counterfactual analysis of events. Previous research indicates that regret emerges at around 6 years of age, marginally later than the age at which children begin to answer counterfactual questions correctly. We hypothesized that the late emergence of regret relative to early counterfactual thinking is a result…

  7. Robust controllers for the Middeck Active Control Experiment using Popov controller synthesis

    NASA Technical Reports Server (NTRS)

    How, Jonathan P.; Hall, Steven R.

    1993-01-01

    Recent work in robust control with real parameter uncertainties has focused on absolute stability and its connections to real mu theory. In particular, the research has investigated the Popov stability criterion and its associated Lur'e-Postnikov Liapunov functions. State space representations of this Popov stability analysis tests are included in an H2 design formulation to provide a powerful technique for robust controller synthesis. This synthesis approach uses a state space optimization procedure to design controllers that minimize an overbound of an H2 cost functional and satisfy stability analysis tests based on the Popov multiplier. The controller and stability multiplier coefficients are optimized simultaneously, which avoids the iteration and curve-fitting procedures required by the D-K algorithm of mu synthesis. While previous work has demonstrated this synthesis approach on benchmark control problems, the purpose of this paper is to use Popov controller synthesis to design robust compensators for the Middeck Active Control Experiment (MACE).

  8. Skylab experiment performance evaluation manual. Appendix R: Experiment T020 foot controlled maneuvering unit (MSFC)

    NASA Technical Reports Server (NTRS)

    Tonetti, B. B.

    1972-01-01

    A series of analyses for experiment T020, foot controlled maneuvering unit (MSFC), to be used for evaluating the performance of the Skylab corollary experiments under preflight, inflight and post-flight conditions is reported. Experiment contingency plan procedure and malfunction analyses are presented in order to assist in making the experiment operationally successful.

  9. Dynamic nonprehensile manipulation: Controllability, planning, and experiments

    SciTech Connect

    Lynch, K.M.; Mason, M.T.

    1999-01-01

    The authors are interested in using low-degree-of-freedom robots to perform complex tasks by nonprehensile manipulation (manipulation without a form- or force-closure grasp). By not grasping, the robot can use gravitational, centrifugal, and Coriolis forces as virtual motors to control more degrees of freedom of the part. The part`s extra motion freedoms are exhibited as rolling, slipping, and free flight. This paper describes controllability, motion planning, and implementation of planar dynamic nonprehensile manipulation. The authors show that almost any planar object is controllable by point contact, and the controlling robot requires only two degrees of freedom (a point translating in the plane). They then focus on a one-joint manipulator (with a two-dimensional state space), and show that even this simplest of robots, by using slipping and rolling, can control a planar object to a full-dimensional subset of its six-0dimensional state space. The authors have developed a one-joint robot to perform a variety of dynamic tasks, including snatching an object from a table, rolling an object on the surface of the arm, and throwing and catching. Nonlinear optimization is used to plan robot trajectories that achieve the desired object motion via coupling forces through the nonprehensile contact.

  10. Dawn Spacecraft Reaction Control System Flight Experience

    NASA Technical Reports Server (NTRS)

    Mizukami, Masashi; Nakazono, Barry

    2014-01-01

    The NASA Dawn spacecraft mission is studying conditions and processes of the solar system's earliest epoch by investigating two protoplanets remaining intact since their formations, Ceres and Vesta. Launch was in 2007. Ion propulsion is used to fly to and enter orbit around Vesta, depart Vesta and fly to Ceres, and enter orbit around Ceres. A conventional blowdown hydrazine reaction control system (RCS) is used to provide external torques for attitude control. Reaction wheel assemblies were intended to provide attitude control in most cases. However, the spacecraft experienced one, then two apparent failures of reaction wheels. Also, similar thrusters experienced degradation in a long life application on another spacecraft. Those factors led to RCS being operated in ways completely different than anticipated prior to launch. Numerous mitigations and developments needed to be implemented. The Vesta mission was fully successful. Even with the compromises necessary due to those anomalies, the Ceres mission is also projected to be feasible.

  11. Circulation control lift generation experiment: Hardware development

    NASA Technical Reports Server (NTRS)

    Panontin, T. L.

    1985-01-01

    A circulation control airfoil and its accompanying hardware were developed to allow the investigation of lift generation that is independent of airfoil angle of attack and relative flow velocity. The test equipment, designed for use in a water tunnel, includes the blown airfoil, the support systems for both flow visualization and airfoil load measurement, and the fluid control system, which utilizes hydraulic technology. The primary design tasks, the selected solutions, and the unforseen problems involved in the development of these individual components of hardware are described.

  12. Reproducibility, Controllability, and Optimization of Lenr Experiments

    NASA Astrophysics Data System (ADS)

    Nagel, David J.

    2006-02-01

    Low-energy nuclear reaction (LENR) measurements are significantly and increasingly reproducible. Practical control of the production of energy or materials by LENR has yet to be demonstrated. Minimization of costly inputs and maximization of desired outputs of LENR remain for future developments.

  13. Experiments with a Magnetically Controlled Pendulum

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2007-01-01

    A magnetically controlled pendulum is used for observing free and forced oscillations, including nonlinear oscillations and chaotic motion. A data-acquisition system stores the data and displays time series of the oscillations and related phase plane plots, Poincare maps, Fourier spectra and histograms. The decay constant of the pendulum can be…

  14. ROCK: The readout controller for the KLOE experiment

    SciTech Connect

    Aloisio, A.; Cavaliere, S.; Cevenini, F.; Volpe, D. della; Merola, L. |; Fiore, D.J.; Parascandolo, P.

    1996-02-01

    A read-out controller (ROCK) has been developed for the Data Acquisition System of the KLOE High Energy Physics experiment, based in Frascati, Italy. The ROCK performs data acquisition in an event-driven fashion on the AUXbus, a custom high speed parallel bus. The AUXbus`s main features are data cycles labeled by event number, sparse data scan operations and an asynchronous protocol optimized to achieve data rates up to 15 MHz. On a standard VMEbus, the ROCK allows for data snooping and real-time performance monitoring, without additional overhead on data acquisition. ROCK boards can be linked together via a custom cable bus (Cbus) to build a complex DAQ subsystem. The ROCK board has been designed around three 4.2 K gate XILINX FPGAs. Dual port FIFO banks are used to decouple the asynchronous buses. A preliminary version of the board is presented and test results are briefly discussed.

  15. WebLab of a DC Motor Speed Control Didactical Experiment

    ERIC Educational Resources Information Center

    Bauer, Karine; Mendes, Luciano

    2012-01-01

    Purpose: Weblabs are an additional resource in the execution of experiments in control engineering education, making learning process more flexible both in time, by allowing extra class laboratory activities, and space, bringing the learning experience to remote locations where experimentation facilities would not be available. The purpose of this…

  16. 2. VIEW OF THE EXPERIMENT CONTROL PANEL IN 1970. THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF THE EXPERIMENT CONTROL PANEL IN 1970. THE NUCLEAR SAFETY GROUP CONDUCTED ABOUT 1,700 CRITICAL MASS EXPERIMENTS USING URANIUM AND PLUTONIUM IN SOLUTIONS (900 TESTS), COMPACTED POWDER (300), AND METALLIC FORMS (500). ALL 1,700 CRITICALITY ASSEMBLIES WERE CONTROLLED FROM THIS PANEL. - Rocky Flats Plant, Critical Mass Laboratory, Intersection of Central Avenue & 86 Drive, Golden, Jefferson County, CO

  17. The Additional-Mass Effect of Plates as Determined by Experiments

    NASA Technical Reports Server (NTRS)

    Gracey, William

    1941-01-01

    The apparent increase in the inertia properties of a body moving in a fluid medium has been called the additional-mass effect. This report presents a resume of test procedures and results of experimental determinations of the additional-mass effect of flat plates. In addition to data obtained from various foreign sources and from a NACA investigation in 1933, the results of tests recently conducted by the National Advisory Committee for Aeronautics are included.

  18. Modular Skeletal Evolution in Sticklebacks Is Controlled by Additive and Clustered Quantitative Trait Loci

    PubMed Central

    Miller, Craig T.; Glazer, Andrew M.; Summers, Brian R.; Blackman, Benjamin K.; Norman, Andrew R.; Shapiro, Michael D.; Cole, Bonnie L.; Peichel, Catherine L.; Schluter, Dolph; Kingsley, David M.

    2014-01-01

    Understanding the genetic architecture of evolutionary change remains a long-standing goal in biology. In vertebrates, skeletal evolution has contributed greatly to adaptation in body form and function in response to changing ecological variables like diet and predation. Here we use genome-wide linkage mapping in threespine stickleback fish to investigate the genetic architecture of evolved changes in many armor and trophic traits. We identify >100 quantitative trait loci (QTL) controlling the pattern of serially repeating skeletal elements, including gill rakers, teeth, branchial bones, jaws, median fin spines, and vertebrae. We use this large collection of QTL to address long-standing questions about the anatomical specificity, genetic dominance, and genomic clustering of loci controlling skeletal differences in evolving populations. We find that most QTL (76%) that influence serially repeating skeletal elements have anatomically regional effects. In addition, most QTL (71%) have at least partially additive effects, regardless of whether the QTL controls evolved loss or gain of skeletal elements. Finally, many QTL with high LOD scores cluster on chromosomes 4, 20, and 21. These results identify a modular system that can control highly specific aspects of skeletal form. Because of the general additivity and genomic clustering of major QTL, concerted changes in both protective armor and trophic traits may occur when sticklebacks inherit either marine or freshwater alleles at linked or possible “supergene” regions of the stickleback genome. Further study of these regions will help identify the molecular basis of both modular and coordinated changes in the vertebrate skeleton. PMID:24652999

  19. Modular skeletal evolution in sticklebacks is controlled by additive and clustered quantitative trait Loci.

    PubMed

    Miller, Craig T; Glazer, Andrew M; Summers, Brian R; Blackman, Benjamin K; Norman, Andrew R; Shapiro, Michael D; Cole, Bonnie L; Peichel, Catherine L; Schluter, Dolph; Kingsley, David M

    2014-05-01

    Understanding the genetic architecture of evolutionary change remains a long-standing goal in biology. In vertebrates, skeletal evolution has contributed greatly to adaptation in body form and function in response to changing ecological variables like diet and predation. Here we use genome-wide linkage mapping in threespine stickleback fish to investigate the genetic architecture of evolved changes in many armor and trophic traits. We identify >100 quantitative trait loci (QTL) controlling the pattern of serially repeating skeletal elements, including gill rakers, teeth, branchial bones, jaws, median fin spines, and vertebrae. We use this large collection of QTL to address long-standing questions about the anatomical specificity, genetic dominance, and genomic clustering of loci controlling skeletal differences in evolving populations. We find that most QTL (76%) that influence serially repeating skeletal elements have anatomically regional effects. In addition, most QTL (71%) have at least partially additive effects, regardless of whether the QTL controls evolved loss or gain of skeletal elements. Finally, many QTL with high LOD scores cluster on chromosomes 4, 20, and 21. These results identify a modular system that can control highly specific aspects of skeletal form. Because of the general additivity and genomic clustering of major QTL, concerted changes in both protective armor and trophic traits may occur when sticklebacks inherit either marine or freshwater alleles at linked or possible "supergene" regions of the stickleback genome. Further study of these regions will help identify the molecular basis of both modular and coordinated changes in the vertebrate skeleton. PMID:24652999

  20. A Simple and Inexpensive Device for Slow, Controlled Addition of a Solution to a Reaction Mixture

    NASA Astrophysics Data System (ADS)

    Osvath, Peter

    1995-07-01

    A number of reactions require the slow and controlled addition of a solution containing one reagent to another. Attempting to control the flow rate over a number of hours using a conventional constant pressure addition funnel is a frustrating exercise; commercially available constant volume addition funnels are expensive and must be adjusted by trial and error each time a reaction is carried out. The use of an (expensive) peristaltic pump or syringe pump overcomes these problems but can introduce other complications. We have recently had occasion to carry out the synthesis of thioether macrocycles and cages requiring the slow and controlled addition of DMF solutions of (offensively odoriferous) thiols or (air-sensitive) thiolates to a reactant solution under nitrogen(1), Although the use of a syringe pump was called for, there are obvious difficulties associated with purging the solution and assembling such an apparatus under nitrogen, and we report a simple and inexpensive solution. A Male Luer Lock tip (recovered from a broken syringe) was sweated onto the flattened tip of a pressure-equalizing addition funnel and a syringe needle was attached. Judicious selection of needle length, bore size, and reactant volume can be used to control the addition time simply and reproducibly. With a 250-mL funnel, the flow rate changes by <25% from the beginning to the end of the addition. (In fact, a reduction in the rate of addition may even be advantageous as the reaction proceeds, the reagent in the receiving flask is consumed, its concentration drops, and the rate of reaction will decrease). A piece of fine Teflon tubing of appropriate length attached to the needle can be used to reduce the flow rate even further, but this is only necessary for very slow rates of addition. For example, the time of addition of 200 mL, of an ethanolic solution could be varied from approximately 5 minutes (150mm/17 gauge) to approximately 5 h (200mm/22 gauge), and once the addition time for a

  1. Millikan's Oil-Drop Experiment as a Remotely Controlled Laboratory

    ERIC Educational Resources Information Center

    Eckert, Bodo; Grober, Sebastian; Vetter, Martin; Jodl, Hans-Jorg

    2012-01-01

    The Millikan oil-drop experiment, to determine the elementary electrical charge e and the quantization of charge Q = n [middle dot] e, is an essential experiment in physics teaching but it is hardly performed in class for several reasons. Therefore, we offer this experiment as a remotely controlled laboratory (RCL). We describe the interactivity…

  2. Aeroassist flight experiment guidance, navigation and control

    NASA Technical Reports Server (NTRS)

    Brand, Timothy J.; Engel, Albert G.

    1986-01-01

    The Aeroassist Flight Experiment scheduled for the early 1990's will demonstrate the use of a low L/D lifting brake using aerodynamic drag to return a spacecraft from a high energy to a low earth orbit. The experimental vehicle will be deployed and retrieved by the Shuttle Orbiter. This paper reviews some of the challenges, problems, and solutions encountered to date during guidance system development, with emphasis on technology advances which will benefit an operational Orbit Transfer Vehicle (OTV). Key factors to be discussed include guidance alternatives, aerodynamic modeling, navigation requirements, the impact of atmospheric uncertainties, and flight profile alternatives considered during initial planning.

  3. The run control and monitoring system of the CMS experiment

    SciTech Connect

    Bauer, Gerry; Boyer, Vincent; Branson, James; Brett, Angela; Cano, Eric; Carboni, Andrea; Ciganek, Marek; Cittolin, Sergio; O'Dell, Vivian; Erhan, Samim; Gigi, Dominique; /CERN /Kyungpook Natl. U. /MIT /UCLA /CERN /INFN, Legnaro

    2007-10-01

    The CMS experiment at the LHC at CERN will start taking data in 2008. To configure, control and monitor the experiment during data-taking the Run Control and Monitoring System (RCMS) was developed. This paper describes the architecture and the technology used to implement the RCMS, as well as the deployment and commissioning strategy of this important component of the online software for the CMS experiment.

  4. Flight experience with flight control redundancy management

    NASA Technical Reports Server (NTRS)

    Szalai, K. J.; Larson, R. R.; Glover, R. D.

    1980-01-01

    Flight experience with both current and advanced redundancy management schemes was gained in recent flight research programs using the F-8 digital fly by wire aircraft. The flight performance of fault detection, isolation, and reconfiguration (FDIR) methods for sensors, computers, and actuators is reviewed. Results of induced failures as well as of actual random failures are discussed. Deficiencies in modeling and implementation techniques are also discussed. The paper also presents comparison off multisensor tracking in smooth air, in turbulence, during large maneuvers, and during maneuvers typical of those of large commercial transport aircraft. The results of flight tests of an advanced analytic redundancy management algorithm are compared with the performance of a contemporary algorithm in terms of time to detection, false alarms, and missed alarms. The performance of computer redundancy management in both iron bird and flight tests is also presented.

  5. NASA experiments onboard the controlled impact demonstration

    NASA Technical Reports Server (NTRS)

    Hayduk, R. J.; Alfaro-Bou, E.; Fasanella, E. L.

    1985-01-01

    The structural crashworthiness tests conducted by NASA on the December 1, 1984 controlled impact demonstration are discussed. The components and locations of the data acquisition and photographic systems developed by NASA to evaluate impact loads throughout the aircraft structure and the transmission of loads into the dummies are described. The effectiveness of the NASA designed absorbing seats and the vertical, longitudinal, and transverse impact loads are measured. Data that is extremely applicable to crash dynamics structural research was obtained by the data acquisition system and very low load levels were measured for the NASA energy absorbing seats.

  6. Experience with subsea well control systems

    SciTech Connect

    Coltharp, E.D.; Coffelt, D.E.

    1981-01-01

    Since 1969, Conoco Inc. has installed ten offshore wells and one land test of subsea completion systems. These wells consist of four single zone oil wells plus one water injection well with Thru Flowline (TFL) pumpdown capability and three single zone gas wells plus three dual zone gas wells utilizing the ''Plain Jane'' wellheads without TFL capability. The control systems for these wells have varied from an electro-hydraulic sequential system to a straight discrete hydraulic system. This paper deals with the design, installation, and operational problems encountered and the remedial procedures taken to solve the problems to date.

  7. Atmosphere control for plant growth flight experiments

    NASA Technical Reports Server (NTRS)

    Powell, Ferolyn T.; Sudar, Martin; Timm, Marc; Yost, Bruce

    1989-01-01

    An atmosphere exchange system (AES) has been designed to provide a conditioned atmosphere supply to plant specimens in flight without incurring the large weight and volume associated with bottled gases. The paper examines the atmosphere filter cartridge (AFC) designed to remove trace organic atmosphere contaminants from the Space Shuttle cabin and to condition the cabin atmosphere prior to exposure to plant specimens. The AES and AFC are described and illustrated. The AFC design requirements are discussed and results are presented from tests on the performance of the AFC. Also, consideration is given to the potential applications of the AFC and future design concepts for atmosphere control.

  8. Chemical additive to enhance antimicrobial efficacy of chlorine and control cross-contamination during immersion chill of broiler carcasses.

    PubMed

    Schambach, B T; Berrang, M E; Harrison, M A; Meinersmann, R J

    2014-09-01

    Immersion chilling of broiler carcasses can be a site for cross-contamination between the occasional highly contaminated carcass and those that are co-chilled. Chlorine is often used as an antimicrobial but can be overcome by organic material. A proprietary chlorine stabilizer (T-128) based on phosphoric acid-propylene glycol was tested as a chill tank additive in experiments simulating commercial broiler chilling. In bench-scale experiments, 0.5% T-128 was compared with plain water (control), 50 ppm of chlorine, and the combination of 0.5% T-128 with 50 ppm of chlorine to control transfer of Salmonella and Campylobacter from inoculated wing drummettes to co-chilled uninoculated drummettes. Both chlorine and T-128 lessened cross-contamination with Salmonella (P < 0.05); T-128 and T-128 with chlorine were significantly more effective (P < 0.05) than the control or plain chlorine for control of Campylobacter. T-128 treatments were noted to have a pH of less than 4.0; an additional experiment demonstrated that the antimicrobial effect of T-128 was not due merely to a lower pH. In commercial broiler chilling, a pH close to 6.0 is preferred to maximize chlorine effectiveness, while maintaining water-holding capacity of the meat. In a set of pilot-scale experiments with T-128, a near-ideal pH of 6.3 was achieved by using tap water instead of the distilled water used in bench-scale experiments. Pilot-scale chill tanks were used to compare the combination of 0.5% T-128 and 50 ppm of chlorine with 50 ppm of plain chlorine for control of cross-contamination between whole carcasses inoculated with Salmonella and Campylobacter and co-chilled uninoculated carcasses. The T-128 treatment resulted in significantly less crosscontamination by either direct contact or water transfer with both organisms compared with plain chlorine treatment. T-128 may have use in commercial broiler processing to enhance the effectiveness of chlorine in processing water. PMID:25198851

  9. Hierarchical tailoring of strut architecture to control permeability of additive manufactured titanium implants.

    PubMed

    Zhang, Z; Jones, D; Yue, S; Lee, P D; Jones, J R; Sutcliffe, C J; Jones, E

    2013-10-01

    Porous titanium implants are a common choice for bone augmentation. Implants for spinal fusion and repair of non-union fractures must encourage blood flow after implantation so that there is sufficient cell migration, nutrient and growth factor transport to stimulate bone ingrowth. Additive manufacturing techniques allow a large number of pore network designs. This study investigates how the design factors offered by selective laser melting technique can be used to alter the implant architecture on multiple length scales to control and even tailor the flow. Permeability is a convenient parameter that characterises flow, correlating to structure openness (interconnectivity and pore window size), tortuosity and hence flow shear rates. Using experimentally validated computational simulations, we demonstrate how additive manufacturing can be used to tailor implant properties by controlling surface roughness at a microstructual level (microns), and by altering the strut ordering and density at a mesoscopic level (millimetre). PMID:23910314

  10. Controlling a toxic shock of pentachlorophenol (PCP) to anaerobic digestion using activated carbon addition.

    PubMed

    Xiao, Yeyuan; De Araujo, Cecilia; Sze, Chun Chau; Stuckey, David C

    2015-04-01

    Several powdered and granular activated carbons (PACs and GACs) were tested for adsorption of pentachlorophenol (PCP) in bench-scale anaerobic digestion reactors to control the toxicity of PCP to acetoclastic methanogenesis. Results showed that the adsorption capacities of PAC were reduced by 21-54%, depending on the PAC addition time, in the presence of the methanogenic sludge compared to the controls without sludge. As a preventive measure, PAC at a low dose of 20% (mass ratio to the VSS) added 24 h prior to, or simultaneously with, the addition of PCP could completely eliminate the toxic effects of PCP. At the same dose, PAC also enabled methanogenesis to recover immediately after the sludge had been exposed to PCP for 24h. GAC was not effective in enabling the recovery of methanogenesis due to its slow adsorption kinetics; however, at a dose of 80% it could partially ameliorate the toxic shock of PCP. PMID:25665874

  11. [Our experience with outside laboratory quality control].

    PubMed

    Dochev, D; Arakasheva, V; Nashkov, A; Tsachev, K

    1979-01-01

    The results from the national outside laboratory qualitative control of the clinical diagnostic laboratory investigations for the period September 1975 -- May 1977 were described. The following interlaboratory discrepancy was found on base of a systematic analysis of the data from the last two ring-like check-ups, November 1976 and May 1977, exressed by the variation coefficient (V.C. %); total protein, sodium, potassium and chlorides -- under 10%; cholesterol, urea and total fats -- between 10 and 20%; calcium, phosphorus, iron and creatinine -- over 20%. The highest per cent of admissible results are found with total protein -- to 85%; cholesterol -- to 70.38%; glucosa -- to 73.17%, urea -- to 69.23%, potassium -- to 59.46%, chlorides -- to 57.9%. With sodium, phosphorus, calcium, iron creatinine and uric acid the "admissibility" fluctuates about or under 50 per cent. The values of the qualitative-control indices discussed are comparable with the values obtained from them in the interlaboratory comparisons of other countries. PMID:494628

  12. Low-boiling-point solvent additives can also enable morphological control in polymer solar cells

    SciTech Connect

    Mahadevapuram, Rakesh C.; Carr, John A.; Chen, Yuqing; Bose, Sayantan; Nalwa, Kanwar S.; Petrich, Jacob W.; Chaudhary, Sumit

    2013-11-02

    Processing organic photovoltaic (OPV) blend solutions with high-boiling-point solvent additives has recently been used for morphological control in bulk-heterojunction OPV cells. Here we show that even low-boiling-point solvents can be effective additives. When P3HT:PCBM OPV cells were processed with a low-boiling-point solvent tetrahydrafuran as an additive in parent solvent o-dichlorobenzene, charge extraction increased leading to fill factors as high as 69.5%, without low work-function cathodes, electrode buffer layers or thermal treatment. This was attributed to PCBM demixing from P3HT domains and better vertical phase separation, as indicated by photoluminescence lifetimes, hole mobilities, and shunt leakage currents. Dependence on solvent parameters and applicability beyond P3HT system was also investigated. (C) 2013 Elsevier B.V. All rights reserved.

  13. How to control the scaling of CaCO3: a "fingerprinting technique" to classify additives.

    PubMed

    Verch, Andreas; Gebauer, Denis; Antonietti, Markus; Cölfen, Helmut

    2011-10-01

    A titration set-up coupling ion selective electrodes with pH adjustment was used to analyze the effects of additives present during precipitation of calcium carbonate. Besides industrially well-established antiscalants (sodium triphosphate, citrate, polyacrylate and poly(aspartic acid)), also functional polymers being active in morphosynthesis (polystyrene sulfonate and poly(styrene-alt-maleic acid)) were analyzed. Interestingly each additive acts in its specific way, suggesting the notation "fingerprinting" for a complex interplay of up to five "solution modes" of influencing CaCO(3) precipitation and crystallisation. The results provide new insights into the modes of additive controlled crystallisation, and in the long run, the insights may facilitate the design of precipitation systems that yield complex and tailor-made crystals. PMID:21860865

  14. Flexible robot control: Modeling and experiments

    NASA Technical Reports Server (NTRS)

    Oppenheim, Irving J.; Shimoyama, Isao

    1989-01-01

    Described here is a model and its use in experimental studies of flexible manipulators. The analytical model uses the equivalent of Rayleigh's method to approximate the displaced shape of a flexible link as the static elastic displacement which would occur under end rotations as applied at the joints. The generalized coordinates are thereby expressly compatible with joint motions and rotations in serial link manipulators, because the amplitude variables are simply the end rotations between the flexible link and the chord connecting the end points. The equations for the system dynamics are quite simple and can readily be formulated for the multi-link, three-dimensional case. When the flexible links possess mass and (polar moment of) inertia which are small compared to the concentrated mass and inertia at the joints, the analytical model is exact and displays the additional advantage of reduction in system dimension for the governing equations. Four series of pilot tests have been completed. Studies on a planar single-link system were conducted at Carnegie-Mellon University, and tests conducted at Toshiba Corporation on a planar two-link system were then incorporated into the study. A single link system under three-dimensional motion, displaying biaxial flexure, was then tested at Carnegie-Mellon.

  15. Expectations and experience: Dissociable bases for cognitive control?

    PubMed

    Bugg, Julie M; Diede, Nathaniel T; Cohen-Shikora, Emily R; Selmeczy, Diana

    2015-09-01

    Classic theories emphasized the role of expectations in the intentional control of attention and action. However, recent theorizing has implicated experience-dependent, online adjustments as the primary basis for cognitive control--adjustments that appear to be implicit (Blais, Harris, Guerrero, & Bunge, 2012). The purpose of the current study was to evaluate whether explicit expectations play any role in cognitive control above and beyond experience. In a novel precued lists paradigm, participants were administered abbreviated lists of Stroop trials. For half of the lists, precues led participants to validly expect lists of varying proportion congruency (e.g., mostly congruent [MC], mostly incongruent [MI]; Experiments 1 to 4). The Stroop effect was greater in cued MC relative to uncued MC lists. By contrast, the Stroop effect was equivalent in cued MI and uncued MI lists. Only when preparation was encouraged via a speed manipulation (Experiment 3) or incentives (Experiment 4) did we find evidence of heightened control when an MI list was expected, in the form of a short-lived reduction in the Stroop effect on the first (experience-free) trial. These patterns suggest (a) expectations play a role in the relaxation of cognitive control, independent of experience (as also shown in Experiment 5, wherein expectations were varied while holding experience constant across lists), but (b) experience is the dominant basis for the sustained heightening of cognitive control (after the first trial). Theoretical implications of dissociating the contributions of expectations and experience to cognitive control are discussed, including interpretations of the list-wide proportion congruence effect. PMID:25689002

  16. Experiment pointing control during space shuttle sortie missions

    NASA Technical Reports Server (NTRS)

    Nicaise, P. D.

    1972-01-01

    The pointing and stability problems of the space shuttle sortie mission are examined from the standpoint of basic shuttle capability and the techniques that could be used for improving this capability to accommodate a maximum number of experiments. Augmentation of the basic shuttle control system is proposed to provide an acceptable pointing environment. A stabilized reference base is recommended as a general pointing instrument for certain earth observation and astronomy experiments. Simulation results are presented which were obtained by modeling the Skylab Experiment Pointing Control (EPC) system on a thruster controlled shuttle.

  17. Reproducible and controllable induction voltage adder for scaled beam experiments.

    PubMed

    Sakai, Yasuo; Nakajima, Mitsuo; Horioka, Kazuhiko

    2016-08-01

    A reproducible and controllable induction adder was developed using solid-state switching devices and Finemet cores for scaled beam compression experiments. A gate controlled MOSFET circuit was developed for the controllable voltage driver. The MOSFET circuit drove the induction adder at low magnetization levels of the cores which enabled us to form reproducible modulation voltages with jitter less than 0.3 ns. Preliminary beam compression experiments indicated that the induction adder can improve the reproducibility of modulation voltages and advance the beam physics experiments. PMID:27587112

  18. Evaluating vortex generator jet experiments for turbulent flow separation control

    NASA Astrophysics Data System (ADS)

    von Stillfried, F.; Kékesi, T.; Wallin, S.; Johansson, A. V.

    2011-12-01

    Separating turbulent boundary-layers can be energized by streamwise vortices from vortex generators (VG) that increase the near wall momentum as well as the overall mixing of the flow so that flow separation can be delayed or even prevented. In general, two different types of VGs exist: passive vane VGs (VVG) and active VG jets (VGJ). Even though VGs are already successfully used in engineering applications, it is still time-consuming and computationally expensive to include them in a numerical analysis. Fully resolved VGs in a computational mesh lead to a very high number of grid points and thus, computational costs. In addition, computational parameter studies for such flow control devices take much time to set-up. Therefore, much of the research work is still carried out experimentally. KTH Stockholm develops a novel VGJ model that makes it possible to only include the physical influence in terms of the additional stresses that originate from the VGJs without the need to locally refine the computational mesh. Such a modelling strategy enables fast VGJ parameter variations and optimization studies are easliy made possible. For that, VGJ experiments are evaluated in this contribution and results are used for developing a statistical VGJ model.

  19. Using Embryology Screencasts: A Useful Addition to the Student Learning Experience?

    ERIC Educational Resources Information Center

    Evans, Darrell J. R.

    2011-01-01

    Although podcasting has been a well used resource format in the last few years as a way of improving the student learning experience, the inclusion of enhanced audiovisual formats such as screencasts has been less used, despite the advantage that they work well for both visual and auditory learners. This study examines the use of and student…

  20. Designing Location-Based Learning Experiences for People with Intellectual Disabilities and Additional Sensory Impairments

    ERIC Educational Resources Information Center

    Brown, David J.; McHugh, David; Standen, Penny; Evett, Lindsay; Shopland, Nick; Battersby, Steven

    2011-01-01

    The research reported here is part of a larger project which seeks to combine serious games (or games-based learning) with location-based services to help people with intellectual disabilities and additional sensory impairments to develop work based skills. Specifically this paper reports on where these approaches are combined to scaffold the…

  1. A unified control system for the STAR experiment

    SciTech Connect

    Gross, J.; McShane, T.S.; Cherney, M. . Dept. of Physics)

    1994-02-01

    The control system for the STAR experiment at RHIC is presented. The VME-based architecture is described. Reasons for the hardware and software choices are discussed. A significant new application of a slow control system (EPICS) to a run control setting is discussed. Interfaces to the detector subsystems are described. The initial implementation of the control systems for the baseline STAR detector is summarized.

  2. Compliance and control characteristics of an additive manufactured-flexure stage

    SciTech Connect

    Lee, ChaBum; Tarbutton, Joshua A.

    2015-04-15

    This paper presents a compliance and positioning control characteristics of additive manufactured-nanopositioning system consisted of the flexure mechanism and voice coil motor (VCM). The double compound notch type flexure stage was designed to utilize the elastic deformation of two symmetrical four-bar mechanisms to provide a millimeter-level working range. Additive manufacturing (AM) process, stereolithography, was used to fabricate the flexure stage. The AM stage was inspected by using 3D X-ray computerized tomography scanner: air-voids and shape irregularity. The compliance, open-loop resonance peak, and damping ratio of the AM stage were measured 0.317 mm/N, 80 Hz, and 0.19, respectively. The AM stage was proportional-integral-derivative positioning feedback-controlled and the capacitive type sensor was used to measure the displacement. As a result, the AM flexure mechanism was successfully 25 nm positioning controlled within 500 μm range. The resonance peak was found approximately at 280 Hz in closed-loop. This research showed that the AM flexure mechanism and the VCM can provide millimeter range with high precision and can be a good alternative to an expensive metal-based flexure mechanism and piezoelectric transducer.

  3. Multiple small RNAs act additively to integrate sensory information and control quorum sensing in Vibrio harveyi

    PubMed Central

    Tu, Kimberly C.; Bassler, Bonnie L.

    2007-01-01

    Quorum sensing is a cell–cell communication mechanism that bacteria use to collectively regulate gene expression and, at a higher level, to coordinate group behavior. In the bioluminescent marine bacterium Vibrio harveyi, sensory information from three independent quorum-sensing systems converges on the shared response regulator LuxO. When LuxO is phosphorylated, it activates the expression of a putative repressor that destabilizes the mRNA encoding the master quorum-sensing transcriptional regulator LuxR. In the closely related species Vibrio cholerae, this repressor was revealed to be the RNA chaperone Hfq together with four small regulatory RNAs (sRNAs) called Qrr1–4 (quorum regulatory RNA). Here, we identify five Qrr sRNAs that control quorum sensing in V. harveyi. Mutational analysis reveals that only four of the five Qrrs are required for destabilization of the luxR mRNA. Surprisingly, unlike in V. cholerae where the sRNAs act redundantly, in V. harveyi, the Qrr sRNAs function additively to control quorum sensing. This latter mechanism produces a gradient of LuxR that, in turn, enables differential regulation of quorum-sensing target genes. Other regulators appear to be involved in control of V. harveyi qrr expression, allowing the integration of additional sensory information into the regulation of quorum-sensing gene expression. PMID:17234887

  4. Compliance and control characteristics of an additive manufactured-flexure stage.

    PubMed

    Lee, ChaBum; Tarbutton, Joshua A

    2015-04-01

    This paper presents a compliance and positioning control characteristics of additive manufactured-nanopositioning system consisted of the flexure mechanism and voice coil motor (VCM). The double compound notch type flexure stage was designed to utilize the elastic deformation of two symmetrical four-bar mechanisms to provide a millimeter-level working range. Additive manufacturing (AM) process, stereolithography, was used to fabricate the flexure stage. The AM stage was inspected by using 3D X-ray computerized tomography scanner: air-voids and shape irregularity. The compliance, open-loop resonance peak, and damping ratio of the AM stage were measured 0.317 mm/N, 80 Hz, and 0.19, respectively. The AM stage was proportional-integral-derivative positioning feedback-controlled and the capacitive type sensor was used to measure the displacement. As a result, the AM flexure mechanism was successfully 25 nm positioning controlled within 500 μm range. The resonance peak was found approximately at 280 Hz in closed-loop. This research showed that the AM flexure mechanism and the VCM can provide millimeter range with high precision and can be a good alternative to an expensive metal-based flexure mechanism and piezoelectric transducer. PMID:25933897

  5. Compliance and control characteristics of an additive manufactured-flexure stage

    NASA Astrophysics Data System (ADS)

    Lee, ChaBum; Tarbutton, Joshua A.

    2015-04-01

    This paper presents a compliance and positioning control characteristics of additive manufactured-nanopositioning system consisted of the flexure mechanism and voice coil motor (VCM). The double compound notch type flexure stage was designed to utilize the elastic deformation of two symmetrical four-bar mechanisms to provide a millimeter-level working range. Additive manufacturing (AM) process, stereolithography, was used to fabricate the flexure stage. The AM stage was inspected by using 3D X-ray computerized tomography scanner: air-voids and shape irregularity. The compliance, open-loop resonance peak, and damping ratio of the AM stage were measured 0.317 mm/N, 80 Hz, and 0.19, respectively. The AM stage was proportional-integral-derivative positioning feedback-controlled and the capacitive type sensor was used to measure the displacement. As a result, the AM flexure mechanism was successfully 25 nm positioning controlled within 500 μm range. The resonance peak was found approximately at 280 Hz in closed-loop. This research showed that the AM flexure mechanism and the VCM can provide millimeter range with high precision and can be a good alternative to an expensive metal-based flexure mechanism and piezoelectric transducer.

  6. Combustion Module-2 Preparations Completed for SPACEHAB Mission Including the Addition of a New Major Experiment

    NASA Technical Reports Server (NTRS)

    Over, Ann P.

    2001-01-01

    The Combustion Module-1 (CM-1) was a large, state-of-the-art space shuttle Spacelab facility that was designed, built, and operated on STS-83 and STS-94 by a team from the NASA Glenn Research Center composed of civil servants and local support contractors (Analex and Zin Technologies). CM-1 accomplished the incredible task of providing a safe environment to support flammable and toxic gases while providing a suite of diagnostics for science measurements more extensive than any prior shuttle experiment (or anything since). Finally, CM-1 proved that multiple science investigations can be accommodated in one facility, a crucial step for Glenn's Fluids and Combustion Facility developed for the International Space Station. However, the story does not end with CM-1. In 1998, CM-2 was authorized to take the CM-1 accomplishments a big step further by completing three major steps: Converting the entire experiment to operate in a SPACEHAB module. Conducting an extensive hardware refurbishment and upgrading diagnostics (e.g., cameras, gas chromatograph, and numerous sensors). Adding a new, completely different combustion experiment.

  7. Laser Additive Melting and Solidification of Inconel 718: Finite Element Simulation and Experiment

    NASA Astrophysics Data System (ADS)

    Romano, John; Ladani, Leila; Sadowski, Magda

    2016-03-01

    The field of powdered metal additive manufacturing is experiencing a surge in public interest finding uses in aerospace, defense, and biomedical industries. The relative youth of the technology coupled with public interest makes the field a vibrant research topic. The authors have expanded upon previously published finite element models used to analyze the processing of novel engineering materials through the use of laser- and electron beam-based additive manufacturing. In this work, the authors present a model for simulating fabrication of Inconel 718 using laser melting processes. Thermal transport phenomena and melt pool geometries are discussed and validation against experimental findings is presented. After comparing experimental and simulation results, the authors present two correction correlations to transform the modeling results into meaningful predictions of actual laser melting melt pool geometries in Inconel 718.

  8. Additional results on space environmental effects on polymer matrix composites: Experiment A0180

    NASA Technical Reports Server (NTRS)

    Tennyson, R. C.

    1992-01-01

    Additional experimental results on the atomic oxygen erosion of boron, Kevlar, and graphite fiber reinforced epoxy matrix composites are presented. Damage of composite laminates due to micrometeoroid/debris impacts is also examined with particular emphasis on the relationship between damage area and actual hole size due to particle penetration. Special attention is given to one micrometeoroid impact on an aluminum base plate which resulted in ejecta visible on an adjoining vertical flange structure.

  9. Multiplicative noise effects on electroconvection in controlling additive noise by a magnetic field

    NASA Astrophysics Data System (ADS)

    Huh, Jong-Hoon

    2015-12-01

    We report multiplicative noise-induced threshold shift of electroconvection (EC) in the presence of a magnetic field H . Controlling the thermal fluctuation (i.e., additive noise) of the rodlike molecules of nematic liquid crystals by H , the EC threshold is examined at various noise levels [characterized by their intensity and cutoff frequency (fc) ]. For a sufficiently strong H (i.e., ignorable additive noise), a modified noise sensitivity characterizing the shift problem is in good agreement with experimental results for colored as well as white noise (fc→∞ ) ; until now, there was a large deviation for (sufficiently) colored noises. The present study shows that H provides us with ideal conditions for studying the corresponding Carr-Helfrich theory considering pure multiplicative noise.

  10. Multiplicative noise effects on electroconvection in controlling additive noise by a magnetic field.

    PubMed

    Huh, Jong-Hoon

    2015-12-01

    We report multiplicative noise-induced threshold shift of electroconvection (EC) in the presence of a magnetic field H. Controlling the thermal fluctuation (i.e., additive noise) of the rodlike molecules of nematic liquid crystals by H, the EC threshold is examined at various noise levels [characterized by their intensity and cutoff frequency (f(c))]. For a sufficiently strong H (i.e., ignorable additive noise), a modified noise sensitivity characterizing the shift problem is in good agreement with experimental results for colored as well as white noise (f(c)→∞); until now, there was a large deviation for (sufficiently) colored noises. The present study shows that H provides us with ideal conditions for studying the corresponding Carr-Helfrich theory considering pure multiplicative noise. PMID:26764708

  11. A feasibility study of orbiter flight control experiments

    NASA Technical Reports Server (NTRS)

    Geissler, W. H.

    1978-01-01

    The results of a feasibility study of orbiter flight control experiments performed are summarized. Feasibility studies were performed on a group of 14 experiments selected from a candidate list of 35 submitted to the study contractor by the flight control community. Concepts and requirements were developed for the 14 selected experiments and they were ranked on a basis of technical value, feasibility, and cost. It was concluded that all the selected experiments can be considered as potential candidates for the Orbiter Experiment program, which is being formulated for the Orbiter Flight Tests and subsequent operational flights, regardless of the relative ranking established during the study. None of the selected experiments has significant safety implications and the cost of most was estimated to be less than $200K.

  12. Experiments to Populate and Validate a Processing Model for Polyurethane Foam: Additional Data for Structural Foams.

    SciTech Connect

    Rao, Rekha R.; Celina, Mathias C.; Giron, Nicholas Henry; Long, Kevin Nicholas; Russick, Edward M.

    2015-01-01

    We are developing computational models to help understand manufacturing processes, final properties and aging of structural foam, polyurethane PMDI. Th e resulting model predictions of density and cure gradients from the manufacturing process will be used as input to foam heat transfer and mechanical models. BKC 44306 PMDI-10 and BKC 44307 PMDI-18 are the most prevalent foams used in structural parts. Experiments needed to parameterize models of the reaction kinetics and the equations of motion during the foam blowing stages were described for BKC 44306 PMDI-10 in the first of this report series (Mondy et al. 2014). BKC 44307 PMDI-18 is a new foam that will be used to make relatively dense structural supports via over packing. It uses a different catalyst than those in the BKC 44306 family of foams; hence, we expect that the reaction kineti cs models must be modified. Here we detail the experiments needed to characteriz e the reaction kinetics of BKC 44307 PMDI-18 and suggest parameters for the model based on these experiments. In additi on, the second part of this report describes data taken to provide input to the preliminary nonlinear visco elastic structural response model developed for BKC 44306 PMDI-10 foam. We show that the standard cu re schedule used by KCP does not fully cure the material, and, upon temperature elevation above 150 o C, oxidation or decomposition reactions occur that alter the composition of the foam. These findings suggest that achieving a fully cured foam part with this formulation may be not be possible through therma l curing. As such, visco elastic characterization procedures developed for curing thermosets can provide only approximate material properties, since the state of the material continuously evolves during tests.

  13. Design and tuning of standard additive model based fuzzy PID controllers for multivariable process systems.

    PubMed

    Harinath, Eranda; Mann, George K I

    2008-06-01

    This paper describes a design and two-level tuning method for fuzzy proportional-integral derivative (FPID) controllers for a multivariable process where the fuzzy inference uses the inference of standard additive model. The proposed method can be used for any n x n multi-input-multi-output process and guarantees closed-loop stability. In the two-level tuning scheme, the tuning follows two steps: low-level tuning followed by high-level tuning. The low-level tuning adjusts apparent linear gains, whereas the high-level tuning changes the nonlinearity in the normalized fuzzy output. In this paper, two types of FPID configurations are considered, and their performances are evaluated by using a real-time multizone temperature control problem having a 3 x 3 process system. PMID:18558531

  14. In situ vitrification and the effects of soil additives; A mixture experiment case study

    SciTech Connect

    Piepel, G.F.; Shade, J.W. )

    1992-01-01

    This paper presents a case study involving in situ vitrification (ISV), a process for immobilizing chemical or nuclear wastes in soil by melting-dissolving the contaminated soil into a glass block. One goal of the study was to investigate how viscosity and electrical conductivity were affected by mixing CaO and Na{sub 2}O with soil. A three-component constrained-region mixture experiment design was generated and the viscosity and electrical conductivity data collected. Several second-order mixture models were considered, and the Box-Cox transformation technique was applied to select property transformations. The fitted models were used to produce contour and component effects plots.

  15. Experience of Control and Student Satisfaction with Higher Education Services

    ERIC Educational Resources Information Center

    Lee, Jungki; Anantharaman, Sekhar

    2013-01-01

    Although the delivery of satisfactory services is an important strategic goal in many colleges, students are known to face challenges and experience a significant amount of stress during their school life. This study proposes and tests students' experience of control over their college life as a promising factor that would enhance their…

  16. Additive manufacture (3d printing) of plasma diagnostic components and assemblies for fusion experiments

    NASA Astrophysics Data System (ADS)

    Sieck, Paul; Woodruff, Simon; Stuber, James; Romero-Talamas, Carlos; Rivera, William; You, Setthivoine; Card, Alexander

    2015-11-01

    Additive manufacturing (or 3D printing) is now becoming sufficiently accurate with a large range of materials for use in printing sensors needed universally in fusion energy research. Decreasing production cost and significantly lowering design time of energy subsystems would realize significant cost reduction for standard diagnostics commonly obtained through research grants. There is now a well-established set of plasma diagnostics, but these expensive since they are often highly complex and require customization, sometimes pace the project. Additive manufacturing (3D printing) is developing rapidly, including open source designs. Basic components can be printed for (in some cases) less than 1/100th costs of conventional manufacturing. We have examined the impact that AM can have on plasma diagnostic cost by taking 15 separate diagnostics through an engineering design using Conventional Manufacturing (CM) techniques to determine costs of components and labor costs associated with getting the diagnostic to work as intended. With that information in hand, we set about optimizing the design to exploit the benefits of AM. Work performed under DOE Contract DE-SC0011858.

  17. Experiences of clinical tutors with English as an additional language (EAL) students.

    PubMed

    Lu, Hongyan; Maithus, Caroline

    2012-11-01

    Clinical tutors, referred to in the international literature as clinical supervisors, facilitators, mentors or instructors, are responsible for providing and supervising workplace learning opportunities for groups of Bachelor of Nursing (BN) students. They also play a key role in assessing students. The role modeling and support provided by both clinical tutors and registered nurses (RN) or nurse preceptors helps students become familiar with the language in which nursing work is realised. As BN student cohorts in New Zealand have become more diverse in terms of cultures, ethnicities and language backgrounds, clinical tutors have to directly facilitate the development of context-specific and client-focused communication skills for students who speak English as an additional language. We undertook a study which looked at the perceptions of new nursing graduates with English as an additional language (EAL) on the development of spoken language skills for the clinical workplace. As well as interviewing graduates, we spoke to four clinical tutors in order to elicit their views on the language development of EAL students in previous cohorts. This article reports on the themes which emerged from the interviews with the tutors. These include goal setting for communication, integrating students into nursing work, making assessment less stressful, and endorsing independent learning strategies. Based on their observations and on other published research we make some suggestions about ways both clinical tutors and EAL students within their teaching groups could be supported in the development of communication skills for clinical practice. PMID:23421011

  18. Formulation and bioavailability of controlled release salbutamol sulphate tablets using natural additives.

    PubMed

    Nouh, A T; Abd El-Gawad, A H; Guda, T K

    2010-04-01

    Salbutamol sulphate granules and physical mixtures were prepared using mastic with various natural additives. The prepared granules and physical mixtures were examined using IR and DSC. The obtained results indicate that there is no interaction between salbutamol sulphate and the formulation ingredients used. The physical properties and release behavior of the formulated tablets prepared from granules and physical mixtures were evaluated and showed good physical properties. The rate of drug release from tablets prepared from granules was found to be lower than that prepared from physical mixtures at fixed mastic concentration and the same additive. The rate of drug release decreased with increased mastic concentration in formulated tablets. Pectin and sodium alginate allowed the best controlled release rate of the drug. On the basis of the results obtained from the controlled release studies, selected sulbutamol formulations were subjected to an in vivo comparison with commercial sulbutamol tablets. The pharmacokinetic parameters AUC(0-24), C(max), and T(max) of sulbutamol from the selected formulation were determined after administration of a single oral dose of 8 mg and compared statistically using an ANOVA test. There was no significant difference in the AUC(0-24). On the other hand, there was a significant difference in the C(max) and T(max) between the commercial and the formulated tablets. These results demonstrate that the formulated tablets extended the time of the drug effect. PMID:22491165

  19. Low fluid leakoff cementing compositions and filtration control additive for cement

    SciTech Connect

    Forrest, G.T.

    1993-07-20

    A cementing composition is described, for cementing oil or gas wells penetrating subterranean formations, capable of forming a fluid slurry when mixed with water comprising: dry hydraulic cement; and a filtration control additive of from about 0.2 to 5.0 percent by weight, based upon dry hydraulic cement, of finely ground peanut hulls, wherein 10 percent or more of the finely ground peanut hulls is in the particle size range of less than 20 standard sieve mesh and greater than 500 standard sieve mesh. In a process for cementing a casing in an oil or gas well penetrating a subterranean formation wherein a cement slurry, formed by mixing water and hydraulic cement, is pumped down the well to flow upwardly between the casing and the subterranean formation, the improvement is described comprising: utilizing as a filtration control additive of from about 0.2 to 5.0 percent by weight, based upon dry hydraulic cement, of finely ground peanut hulls, and utilizing finely ground peanut hulls wherein 10 percent or more of the finely ground peanut hulls is in the particle size range of less than 20 standard sieve mesh and greater than 500 standard sieve mesh.

  20. A Process Dynamics and Control Experiment for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Spencer, Jordan L.

    2009-01-01

    This paper describes a process control experiment. The apparatus includes a three-vessel glass flow system with a variable flow configuration, means for feeding dye solution controlled by a stepper-motor driven valve, and a flow spectrophotometer. Students use impulse response data and nonlinear regression to estimate three parameters of a model…

  1. Expectations and Experience: Dissociable Bases for Cognitive Control?

    ERIC Educational Resources Information Center

    Bugg, Julie M.; Diede, Nathaniel T.; Cohen-Shikora, Emily R.; Selmeczy, Diana

    2015-01-01

    Classic theories emphasized the role of expectations in the intentional control of attention and action. However, recent theorizing has implicated experience-dependent, online adjustments as the primary basis for cognitive control--adjustments that appear to be implicit (Blais, Harris, Guerrero, & Bunge, 2012). The purpose of the current study…

  2. Selection for increased desiccation resistance in Drosophila melanogaster: Additive genetic control and correlated responses for other stresses

    SciTech Connect

    Hoffmann, A.A.; Parsons, P.A. )

    1989-08-01

    Previously we found that Drosophila melanogaster lines selected for increased desiccation resistance have lowered metabolic rate and behavioral activity levels, and show correlated responses for resistance to starvation and a toxic ethanol level. These results were consistent with a prediction that increased resistance to many environmental stresses may be genetically correlated because of a reduction in metabolic energy expenditure. Here we present experiments on the genetic basis of the selection response and extend the study of correlated responses to other stresses. The response to selection was not sex-specific and involved X-linked and autosomal genes acting additively. Activity differences contributed little to differences in desiccation resistance between selected and control lines. Selected lines had lower metabolic rates than controls in darkness when activity was inhibited. Adults from selected lines showed increased resistance to a heat shock, {sup 60}Co-gamma-radiation, and acute ethanol and acetic acid stress. The desiccation, ethanol and starvation resistance of isofemale lines set up from the F2s of a cross between one of the selected and one of the control lines were correlated. Selected and control lines did not differ in ether-extractable lipid content or in resistance to acetone, ether or a cold shock.

  3. Summary and overview of the CYCLOPS P addition Lagrangian experiment in the Eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Krom, M. D.; Thingstad, T. F.; Brenner, S.; Carbo, P.; Drakopoulos, P.; Fileman, T. W.; Flaten, G. A. F.; Groom, S.; Herut, B.; Kitidis, V.; Kress, N.; Law, C. S.; Liddicoat, M. I.; Mantoura, R. F. C.; Pasternak, A.; Pitta, P.; Polychronaki, T.; Psarra, S.; Rassoulzadegan, F.; Skjoldal, E. F.; Spyres, G.; Tanaka, T.; Tselepides, A.; Wassmann, P.; Wexels Riser, C.; Woodward, E. M. S.; Zodiatis, G.; Zohary, T.

    2005-11-01

    CYCLOPS was a European Framework 5 program to further our understanding of phosphorus cycling in the Eastern Mediterranean. The core of CYCLOPS was a Lagrangian experiment in which buffered phosphoric acid was added to a <4×4 km patch of water together with SF 6 as the inert tracer. The patch was followed for nine days in total. Results obtained prior to the experiment showed that the system was typically ultra-oligotrophic and P-starved with DON:DOP, PON:POP and DIN:DIP all having ratios greatly in excess of 16:1 in surface waters. To our surprise, we found that although the added phosphate was rapidly taken up by the microbial biota, there was a small but significant decrease in chlorophyll a and no increase in primary production, together with an increase in heterotrophic bacterial activity, ciliate numbers and in the gut fullness and egg numbers in the zooplankton community. A microcosm experiment carried out using within-patch and out-of-patch water showed that the phytoplankton community were N and P co-limited while the bacteria and micrograzers were P-limited. Thus this system tends to N and P co-limitation of phytoplankton productivity in summer possibly caused by bioavailable DIN being converted into non-bioavailable forms of DON. On the basis of the data collected within the programme it was concluded that this behavior could be explained by three non-mutually exclusive processes described as (1) trophic by-pass in which the added phosphate gets directly to the grazing part of the predatory food chain from the heterotrophic bacteria bypassing the phytoplankton compartment phosphate, (2) trophic tunnelling in which phosphate is rapidly taken up by both phytoplankton and bacteria via rapid luxury consumption. This causes an immediate change in the phosphorus content but not the abundance of the prey organisms. The added P then "reappears" as responses at the predator level much more rapidly than expected, and (3) mixotrophic by-pass in which inorganic

  4. Controlled powder morphology experiments in megabar 304 stainless steel compaction

    SciTech Connect

    Staudhammer, K.P.; Johnson, K.A.

    1985-01-01

    Experiments with controlled morphology including shape, size, and size distribution were made on 304L stainless steel powders. These experiments involved not only the powder variables but pressure variables of 0.08 to 1.0 Mbar. Also included are measured container strain on the material ranging from 1.5% to 26%. Using a new strain controllable design it was possible to seperate and control, independently, strain and pressure. Results indicate that powder morphology, size distribution, packing density are among the pertinent parameters in predicting compaction of these powders.

  5. A Tuneable Switch for Controlling Environmental Degradation of Bioplastics: Addition of Isothiazolinone to Polyhydroxyalkanoates

    PubMed Central

    Woolnough, Catherine Anne; Yee, Lachlan Hartley; Charlton, Timothy Stuart; Foster, Leslie John Ray

    2013-01-01

    Controlling the environmental degradation of polyhydroxybutyrate (PHB) and polyhydroxyvalerate (P(HB-co-HV)) bioplastics would expand the range of their potential applications. Combining PHB and P(HB-co-HV) films with the anti-fouling agent 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOI, <10% w/w) restricted microbial colonisation in soil, but did not significantly affect melting temperature or the tensile strength of films. DCOI films showed reduced biofouling and postponed the onset of weight loss by up to 100 days, a 10-fold increase compared to unmodified films where the microbial coverage was significant. In addition, the rate of PHA-DCOI weight loss, post-onset, reduced by about 150%; in contrast a recorded weight loss of only 0.05% per day for P(HB-co-HV) with a 10% DCOI loading was observed. This is in stark contrast to the unmodified PHB film, where a recorded weight loss of only 0.75% per day was made. The ‘switch’ that initiates film weight loss, and its subsequent reduced rate, depended on the DCOI loading to control biofouling. The control of biofouling and environmental degradation for these DCOI modified bioplastics increases their potential use in biodegradable applications. PMID:24146779

  6. The food additive vanillic acid controls transgene expression in mammalian cells and mice

    PubMed Central

    Gitzinger, Marc; Kemmer, Christian; Fluri, David A.; Daoud El-Baba, Marie; Weber, Wilfried; Fussenegger, Martin

    2012-01-01

    Trigger-inducible transcription-control devices that reversibly fine-tune transgene expression in response to molecular cues have significantly advanced the rational reprogramming of mammalian cells. When designed for use in future gene- and cell-based therapies the trigger molecules have to be carefully chosen in order to provide maximum specificity, minimal side-effects and optimal pharmacokinetics in a mammalian organism. Capitalizing on control components that enable Caulobacter crescentus to metabolize vanillic acid originating from lignin degradation that occurs in its oligotrophic freshwater habitat, we have designed synthetic devices that specifically adjust transgene expression in mammalian cells when exposed to vanillic acid. Even in mice transgene expression was robust, precise and tunable in response to vanillic acid. As a licensed food additive that is regularly consumed by humans via flavoured convenience food and specific fresh vegetable and fruits, vanillic acid can be considered as a safe trigger molecule that could be used for diet-controlled transgene expression in future gene- and cell-based therapies. PMID:22187155

  7. Analytical optimal controls for the state constrained addition and removal of cryoprotective agents

    PubMed Central

    Chicone, Carmen C.; Critser, John K.

    2014-01-01

    Cryobiology is a field with enormous scientific, financial and even cultural impact. Successful cryopreservation of cells and tissues depends on the equilibration of these materials with high concentrations of permeating chemicals (CPAs) such as glycerol or 1,2 propylene glycol. Because cells and tissues are exposed to highly anisosmotic conditions, the resulting gradients cause large volume fluctuations that have been shown to damage cells and tissues. On the other hand, there is evidence that toxicity to these high levels of chemicals is time dependent, and therefore it is ideal to minimize exposure time as well. Because solute and solvent flux is governed by a system of ordinary differential equations, CPA addition and removal from cells is an ideal context for the application of optimal control theory. Recently, we presented a mathematical synthesis of the optimal controls for the ODE system commonly used in cryobiology in the absence of state constraints and showed that controls defined by this synthesis were optimal. Here we define the appropriate model, analytically extend the previous theory to one encompassing state constraints, and as an example apply this to the critical and clinically important cell type of human oocytes, where current methodologies are either difficult to implement or have very limited success rates. We show that an enormous increase in equilibration efficiency can be achieved under the new protocols when compared to classic protocols, potentially allowing a greatly increased survival rate for human oocytes, and pointing to a direction for the cryopreservation of many other cell types. PMID:22527943

  8. [Requirements for drug approval and additional benefits assessment: Regulatory aspects and experiences].

    PubMed

    Broich, K; Löbker, W; Schulte, A; Beinlich, P; Müller, T

    2016-04-01

    The early assessment of benefits of newly approved drugs with novel active substances or new applications, which came into force on 1 January 2011 still represents a challenge to all parties involved. This article highlights the definitions, regulatory requirements and interaction between drug marketing approval and early assessment of benefits in Germany. The constellation of an extensively harmonized European and even international drug authorization process with a predominantly national regulation of drug reimbursement situation inevitably causes friction, which could be markedly reduced through early joint advisory discussions during the planning phase for pivotal clinical trials. During the year 2015 the Federal Institute for Drugs and Medical Devices (BfArM) carried out 300 scientific advice procedures of which 34 were concerned with applications in the field of indications for the central nervous system (CNS). In comparison 98 advisory meetings were held by the Federal Joint Committee (G-BA) of which the BfArM provided advice in 12 instances and in 2 cases on CNS indications. Study design, endpoints and appropriate comparative therapies are the key issues in exchanges and discussions between the BfArM, the G‑BA and applicants. Under these aspects the BfArM and G‑BA promote an early and consistent involvement in early advice procedures regarding the prerequisites for drug approval and assessment of additional benefits. PMID:27003322

  9. In-space technology flight experiments: Middeck 0-gravity Dynamics Experiment (MODE) and Middeck Active Control Experiment (MACE)

    NASA Technical Reports Server (NTRS)

    Venneri, Samuel L.

    1991-01-01

    The topics addressed are covered in viewgraph form. The objective of the Middeck 0-gravity Dynamics Experiment (MODE) programs is to study gravity dependent nonlinearities associated with fluid slosh and truss structure dynamics. MODE provides a reusable facility for on-orbit dynamics testing of small scale test articles in the shirt sleeve environment on the Shuttle middeck. Flight program objective of Middeck Active Control Experiment (MACE) is to study gravity effects on the performance and stability of controlled structures.

  10. Silica nanoparticle addition to control the calcium-leaching in cement-based materials

    NASA Astrophysics Data System (ADS)

    Gaitero, J. J.; Sáez de Ibarra, Y.; Erkizia, E.; Campillo, I.

    2006-05-01

    The calcium leaching of the cement hydrated matrix is of vital importance for constructions like water containers, dams, bridges, etc which have to be in contact with water during their lifetime. The aim of this work is the study of the reduction of such a negative phenomenon by the addition of silica nanoparticles. Several characterisation techniques such as 29Si MAS NMR, X-ray diffraction, mercury intrusion porosimetry and EDX-microanalysis have been used to evaluate the effect of the nanoparticles in the cement matrix nanostructure and in their impact on the evolution of the Ca leaching throughout time. Subsequent analysis of the results indicates that silica nanoparticles can reduce the Ca-leaching both decreasing the amount of portlandite in the matrix and controlling the degradation rate of the C-S-H gel.

  11. Additive controlled synthesis of gold nanorods (GNRs) for two-photon luminescence imaging of cancer cells

    NASA Astrophysics Data System (ADS)

    Zhu, Jing; Yong, Ken-Tye; Roy, Indrajit; Hu, Rui; Ding, Hong; Zhao, Lingling; Swihart, Mark T.; He, Guang S.; Cui, Yiping; Prasad, Paras N.

    2010-07-01

    Gold nanorods (GNRs) with a longitudinal surface plasmon resonance peak that is tunable from 600 to 1100 nm have been fabricated in a cetyl trimethylammoniumbromide (CTAB) micellar medium using hydrochloric acid and silver nitrate as additives to control their shape and size. By manipulating the concentrations of silver nitrate and hydrochloric acid, the aspect ratio of the GNRs was reliably and reproducibly tuned from 2.5 to 8. The GNRs were first coated with polyelectrolyte multilayers and then bioconjugated to transferrin (Tf) to target pancreatic cancer cells. Two-photon imaging excited from the bioconjugated GNRs demonstrated receptor-mediated uptake of the bioconjugates into Panc-1 cells, overexpressing the transferrin receptor (TfR). The bioconjugated GNR formulation exhibited very low toxicity, suggesting that it is biocompatible and potentially suitable for targeted two-photon bioimaging.

  12. Controlling the corrosion and cathodic activation of magnesium via microalloying additions of Ge

    NASA Astrophysics Data System (ADS)

    Liu, R. L.; Hurley, M. F.; Kvryan, A.; Williams, G.; Scully, J. R.; Birbilis, N.

    2016-06-01

    The evolution of corrosion morphology and kinetics for magnesium (Mg) have been demonstrated to be influenced by cathodic activation, which implies that the rate of the cathodic partial reaction is enhanced as a result of anodic dissolution. This phenomenon was recently demonstrated to be moderated by the use of arsenic (As) alloying as a poison for the cathodic reaction, leading to significantly improved corrosion resistance. The pursuit of alternatives to toxic As is important as a means to imparting a technologically safe and effective corrosion control method for Mg (and its alloys). In this work, Mg was microalloyed with germanium (Ge), with the aim of improving corrosion resistance by retarding cathodic activation. Based on a combined analysis herein, we report that Ge is potent in supressing the cathodic hydrogen evolution reaction (reduction of water) upon Mg, improving corrosion resistance. With the addition of Ge, cathodic activation of Mg subject to cyclic polarisation was also hindered, with beneficial implications for future Mg electrodes.

  13. Quality control of laser- and powder bed-based Additive Manufacturing (AM) technologies

    NASA Astrophysics Data System (ADS)

    Berumen, Sebastian; Bechmann, Florian; Lindner, Stefan; Kruth, Jean-Pierre; Craeghs, Tom

    The quality of metal components manufactured by laser- and powder bed-based additive manufacturing technologies has continuously been improved over the last years. However, to establish this production technology in industries with very high quality standards the accessibility of prevalent quality management methods to all steps of the process chain needs still to be enhanced. This publication describes which tools are and will be available to fulfil those requirements from the perspective of a laser machine manufacturer. Generally five aspects of the part building process are covered by separate Quality Management (QM) modules: the powder quality, the temperature management, the process gas atmosphere, the melt pool behaviour and the documentation module. This paper sets the focus on melt pool analysis and control.

  14. Catalytic enantioselective addition of organoboron reagents to fluoroketones controlled by electrostatic interactions

    NASA Astrophysics Data System (ADS)

    Lee, Kyunga; Silverio, Daniel L.; Torker, Sebastian; Robbins, Daniel W.; Haeffner, Fredrik; van der Mei, Farid W.; Hoveyda, Amir H.

    2016-08-01

    Organofluorine compounds are central to modern chemistry, and broadly applicable transformations that generate them efficiently and enantioselectively are in much demand. Here we introduce efficient catalytic methods for the addition of allyl and allenyl organoboron reagents to fluorine-substituted ketones. These reactions are facilitated by readily and inexpensively available catalysts and deliver versatile and otherwise difficult-to-access tertiary homoallylic alcohols in up to 98% yield and >99:1 enantiomeric ratio. Utility is highlighted by a concise enantioselective approach to the synthesis of the antiparasitic drug fluralaner (Bravecto, presently sold as the racemate). Different forms of ammonium–organofluorine interactions play a key role in the control of enantioselectivity. The greater understanding of various non-bonding interactions afforded by these studies should facilitate the future development of transformations that involve fluoroorganic entities.

  15. Stereo- and Temporally Controlled Coordination Polymerization Triggered by Alternating Addition of a Lewis Acid and Base.

    PubMed

    Liu, Bo; Cui, Dongmei; Tang, Tao

    2016-09-19

    Significant progress has been made with regard to temporally controlled radical and ring-opening polymerizations, for example, by means of chemical reagents, light, and voltage, whereas quantitative switch coordination polymerization is still challenging. Herein, we report the temporally and stereocontrolled 3,4-polymerization of isoprene through allosterically regulating the active metal center by alternating addition of Lewis basic pyridine to "poison" the Lewis acidic active metal species through acid-base interactions and Lewis acidic Al(i) Bu3 to release the original active species through pyridine abstraction. This process is quick, quantitative, and can be repeated multiple times while maintaining high 3,4-selectivity. Moreover, this strategy is also effective for the switch copolymerization of isoprene and styrene with dual 3,4- and syndiotactic selectivity. Tuning the switch cycles and intervals enables the isolation of various copolymers with different distributions of 3,4-polyisoprene and syndiotactic polystyrene sequences. PMID:27539866

  16. Catalytic enantioselective addition of organoboron reagents to fluoroketones controlled by electrostatic interactions.

    PubMed

    Lee, KyungA; Silverio, Daniel L; Torker, Sebastian; Robbins, Daniel W; Haeffner, Fredrik; van der Mei, Farid W; Hoveyda, Amir H

    2016-08-01

    Organofluorine compounds are central to modern chemistry, and broadly applicable transformations that generate them efficiently and enantioselectively are in much demand. Here we introduce efficient catalytic methods for the addition of allyl and allenyl organoboron reagents to fluorine-substituted ketones. These reactions are facilitated by readily and inexpensively available catalysts and deliver versatile and otherwise difficult-to-access tertiary homoallylic alcohols in up to 98% yield and >99:1 enantiomeric ratio. Utility is highlighted by a concise enantioselective approach to the synthesis of the antiparasitic drug fluralaner (Bravecto, presently sold as the racemate). Different forms of ammonium-organofluorine interactions play a key role in the control of enantioselectivity. The greater understanding of various non-bonding interactions afforded by these studies should facilitate the future development of transformations that involve fluoroorganic entities. PMID:27442282

  17. Mathematical inference and control of molecular networks from perturbation experiments

    NASA Astrophysics Data System (ADS)

    Mohammed-Rasheed, Mohammed

    in order to affect the time evolution of molecular activity in a desirable manner. In this proposal, we address both the inference and control problems of GRNs. In the first part of the thesis, we consider the control problem. We assume that we are given a general topology network structure, whose dynamics follow a discrete-time Markov chain model. We subsequently develop a comprehensive framework for optimal perturbation control of the network. The aim of the perturbation is to drive the network away from undesirable steady-states and to force it to converge to a unique desirable steady-state. The proposed framework does not make any assumptions about the topology of the initial network (e.g., ergodicity, weak and strong connectivity), and is thus applicable to general topology networks. We define the optimal perturbation as the minimum-energy perturbation measured in terms of the Frobenius norm between the initial and perturbed networks. We subsequently demonstrate that there exists at most one optimal perturbation that forces the network into the desirable steady-state. In the event where the optimal perturbation does not exist, we construct a family of sub-optimal perturbations that approximate the optimal solution arbitrarily closely. In the second part of the thesis, we address the inference problem of GRNs from time series data. We model the dynamics of the molecules using a system of ordinary differential equations corrupted by additive white noise. For large-scale networks, we formulate the inference problem as a constrained maximum likelihood estimation problem. We derive the molecular interactions that maximize the likelihood function while constraining the network to be sparse. We further propose a procedure to recover weak interactions based on the Bayesian information criterion. For small-size networks, we investigated the inference of a globally stable 7-gene melanoma genetic regulatory network from genetic perturbation experiments. We considered five

  18. Low-Cost Undergraduate Control Systems Experiments Using Microcontroller-Based Control of a DC Motor

    ERIC Educational Resources Information Center

    Gunasekaran, M.; Potluri, R.

    2012-01-01

    This paper presents low-cost experiments for a control systems laboratory module that is worth one and a third credits. The experiments are organized around the microcontroller-based control of a permanent magnet dc motor. The experimental setups were built in-house. Except for the operating system, the software used is primarily freeware or free…

  19. Growth control of nonionic reverse micelles by surfactant and solvent molecular architecture and water addition.

    PubMed

    Shrestha, Lok Kumar; Shrestha, Rekha Goswami; Aramaki, Kenji

    2011-06-01

    This paper describes a facile route to the shape, size, and structure control of reversed micelles by surfactant and solvent molecular architecture and water addition. Nonionic reverse micellar size is found to increase with increase in hydrophilic headgroup size of surfactant, whose scheme is understood in terms of decrease in the critical packing parameter (cpp). On the other hand, an opposite trend is observed with increase in lipophilicity of the surfactant. This is caused by the repulsive excluded volume interactions, which increases with the volume of lipophilic moiety of surfactant; as a result, the micelle interface tends to become more curved and micelles shrink. Solvent molecular structure has played a crucial role; increasing hydrocarbon chain length of alkanes favored one dimensional micellar growth. We note that long chain oil has a poor penetration tendency to lipophilic tail of surfactant and decreases the cpp. Solvent polarity is also crucial; globular micelles are formed in short chain oil cyclohexane. We note that decreasing chain length of oil mimic the decrease in the headgroup size of surfactant; rod-to-sphere type transition in the micellar structure. Addition of trace water favors micellar growth; maximum dimension and micellar cross section increases with increase in water concentration. The sizes of the water incorporated reverse micelles (or w/o microemulsion) are much bigger than the empty micelles. Micellar structure was confirmed by small angle X-ray scattering (SAXS) and supported by rheology. PMID:21770115

  20. Tank Pressure Control Experiment/thermal Phenomena (TPCE/TP)

    NASA Technical Reports Server (NTRS)

    Hasan, M. M.; Knoll, R. H.

    1992-01-01

    The 'Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP)' is a reflight of the tank pressure control experiment (TPCE), flown on STS-43 in a standard Get-Away Special (GAS) container in August 1991. The TPCE obtained extensive video and digital data of the jet induced mixing process in a partially filled tank in low gravity environments. It also provided limited data on the thermal processes involved. The primary objective of the reflight of TPCE is to investigate experimentally the phenomena of liquid superheating and pool nucleate boiling at very low heat fluxes in a long duration low gravity environment. The findings of this experiment will be of direct relevance to space based subcritical cryogenic fluid system design and operation. Experiment hardware and results from the first TPCE are described in outline and graphic form.

  1. The CERN antiproton source: Controls aspects of the additional collector ring and fast sampling devices

    NASA Astrophysics Data System (ADS)

    Chohan, V.

    1990-08-01

    The upgrade of the CERN antiproton source, meant to gain an order of magnitude in antiproton flux, required the construction of an additional ring to complement the existing antiproton accumulator (AA) and an entire rebuild of the target zone. The AA also needed major modifications to handle the increased flux and perform purely as an accumulator, preceded by collection in the collector ring (AC). The upgrade, known as the ACOL (antiproton collector) project, was approved under strict time and budgetary constraints and the existing AA control system, based on the Proton Synchrotron (PS) Divisional norms of CAMAC and Norsk-Data computers, had to be extended in the light of this. The limited (9 months) installation period for the whole upgrade meant that substantial preparatory and planning activities had to be carried out during the normal running of the AA. Advantage was taken of the upgrade to improve and consolidate the AA. Some aspects of the control system related to this upgrade are discussed together with the integration of new applications and instrumentation. The overall machine installation and running-in was carried out within the defined milestones and the project has now achieved the physics design goals.

  2. Low-cost Active Structural Control Space Experiment (LASC)

    NASA Technical Reports Server (NTRS)

    Robinett, Rush; Bukley, Angelia P.

    1992-01-01

    The DOE Lab Director's Conference identified the need for the DOE National Laboratories to actively and aggressively pursue ways to apply DOE technology to problems of national need. Space structures are key elements of DOD and NASA space systems and a space technology area in which DOE can have a significant impact. LASC is a joint agency space technology experiment (DOD Phillips, NASA Marshall, and DOE Sandia). The topics are presented in viewgraph form and include the following: phase 4 investigator testbed; control of large flexible structures in orbit; INFLEX; Controls, Astrophysics; and structures experiments in space; SARSAT; and LASC mission objectives.

  3. Control system design for spacecraft formation flying: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Robertson, Andrew Dunbar

    Spacecraft formation flying is an enabling technology for many future space science missions, such as separated spacecraft interferometers (SSI). However the sensing, control and coordination of such instruments pose many new design challenges. SSI missions will require precise relative sensing and control, fuel-efficient, fuel-balanced operation to maximize mission life and group-level autonomy to reduce operations costs. Enabling these new formation flying capabilities requires precise relative sensing and estimation, enhanced control capabilities such as cooperative control (multiple independent spacecraft acting together), group-level formation management and informed design of a system architecture to manage distributed sensing and control-system resources. This research defines an end-to-end control system, including the key elements unique to the formation flying problem: cooperative control, relative sensing, coordination, and the control-system architecture. A new control-system design optimizes performance under typical spacecraft constraints (e.g., on-off actuators, finite fuel, limited computation power, limited contact with ground control, etc.). Standard control techniques have been extended, and new ones synthesized to meet these goals. In designing this control system, several contributions have been made to the field of spacecraft formation flying control including: an analytic two-vehicle fuel-time-optimal cooperative control algorithm, a fast numeric multi-vehicle, optimal cooperative control algorithm that can be used as a feedforward or a feedback controller, a fleet-level coordinator for autonomous fuel balancing, validation of GPS-based relative sensing for formation flying, and trade studies of the relative control and relative-estimation-architecture design problems. These research contributions are mapped to possible applications for three spacecraft formation flying missions currently in development. The lessons learned from this research

  4. Experiments in teleoperator and autonomous control of space robotic vehicles

    NASA Technical Reports Server (NTRS)

    Alexander, Harold L.

    1990-01-01

    A research program and strategy are described which include fundamental teleoperation issues and autonomous-control issues of sensing and navigation for satellite robots. The program consists of developing interfaces for visual operation and studying the consequences of interface designs as well as developing navigation and control technologies based on visual interaction. A space-robot-vehicle simulator is under development for use in virtual-environment teleoperation experiments and neutral-buoyancy investigations. These technologies can be utilized in a study of visual interfaces to address tradeoffs between head-tracking and manual remote cameras, panel-mounted and helmet-mounted displays, and stereoscopic and monoscopic display systems. The present program can provide significant data for the development of control experiments for autonomously controlled satellite robots.

  5. Experiment Study on Fuzzy Vibration Control of Solar Panel

    NASA Astrophysics Data System (ADS)

    Li, Dongxu X.; Xu, Rui; Jiang, Jiangjian P.

    Some flexible appendages of spacecraft are cantilever plate structures, such as solar panels. These structures usually have very low damping ratios, high dimensional order, low modal frequencies and parameter uncertainties in dynamics. Their unwanted vibrations will be caused unavoidably, and harmful to the spacecraft. To solve this problem, the dynamic equations of the solar panel with piezoelectric patches are derived, and an accelerometer based fuzzy controller is designed. In order to verify the effectiveness of the vibration control algorithms, experiment research was conducted on a piezoelectric adaptive composite honeycomb cantilever panel. The experiment results demonstrate that the accelerometer-based fuzzy vibration control method can suppress the vibration of the solar panel effectively, the first bending mode damping ratio of the controlled system increase to 1.64%, and that is 3.56 times of the uncontrolled system.

  6. Voyager Saturn encounter attitude and articulation control experience

    NASA Technical Reports Server (NTRS)

    Carlisle, G.; Hill, M.

    1981-01-01

    The Voyager attitude and articulation control system is designed for a three-axis stabilized spacecraft; it uses a biasable sun sensor and a Canopus Star Tracker (CST) for celestial control, as well as a dry inertial reference unit, comprised of three dual-axis dry gryos, for inertial control. A series of complex maneuvers was required during the first of two Voyager spacecraft encounters with Saturn (November 13, 1980); these maneuvers involved rotating the spacecraft simultaneously about two or three axes while maintaining accurate pointing of the scan platform. Titan and Saturn earth occulation experiments and a ring scattering experiment are described. Target motion compensation and the effects of celestial sensor interference are also considered. Failure of the CST, which required an extensive reevaluation of the star reference and attitude control mode strategy, is discussed. Results analyzed thus far show that the system performed with high accuracy, gathering data deeper into Saturn's atmosphere than on any previous planetary encounter.

  7. Possibilities of implanted control in stimulated light scattering experiments

    NASA Astrophysics Data System (ADS)

    Lazarenko, Anatoliy G.; Andreev, Alexandr N.; Kanaev, Andrey V.

    2004-09-01

    Some possibilities of simple and thus reliable schemes of experiment "self-control" exploiting intrinsic features of studied non-linear phenomena like wave front reversal under stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS) and coherent anti-Stokes Raman scattering (CARS) rather than outer sensors and controls are described. The schemes discussed provide input signal dynamic region broadening in stimulated scattering converters and angle of synchronism self-tuning while two frequency pumping.

  8. Slow control systems of the Reactor Experiment for Neutrino Oscillation

    NASA Astrophysics Data System (ADS)

    Choi, J. H.; Jang, H. I.; Choi, W. Q.; Choi, Y.; Jang, J. S.; Jeon, E. J.; Joo, K. K.; Kim, B. R.; Kim, H. S.; Kim, J. Y.; Kim, S. B.; Kim, S. Y.; Kim, W.; Kim, Y. D.; Ko, Y. J.; Lee, J. K.; Lim, I. T.; Pac, M. Y.; Park, I. G.; Park, J. S.; Park, R. G.; Seo, H. K.; Seo, S. H.; Shin, C. D.; Siyeon, K.; Yeo, I. S.; Yu, I.

    2016-02-01

    The RENO experiment has been in operation since August 2011 to measure reactor antineutrino disappearance using identical near and far detectors. For accurate measurements of neutrino mixing parameters and efficient data taking, it is crucial to monitor and control the detector in real time. Environmental conditions also need to be monitored for stable operation of detectors as well as for safety reasons. In this paper, we report the design, hardware, operation, and performance of the slow control system.

  9. Decentralized control experiments on the JPL flexible spacecraft

    NASA Technical Reports Server (NTRS)

    Ozguner, U.; Ossman, K.; Donne, J.; Boesch, M.; Ahmed, A.

    1990-01-01

    Decentralized control experiments were successfully demonstrated for the JPL/AFAL Flexible Structure. A simulation package using MATRIXx showed strong correlation between the simulations and experimental result, while providing a means for test and debug of the various control strategies. Implementation was simplified by a modular software design that was easily transported from the simulation environment to the experimental environment. Control designs worked well for suppression of the dominant modes of the structure. Static decentralized output feedback dampened the excited modes of the structure, but sometimes excited higher order modes upon startup of the controller. A second-order frequency shaping controller helped to eliminate excitation of the higher order modes by attenuating high frequencies in the control effort. However, it also resulted in slightly longer settling times.

  10. Experiments on Socio-Technical Systems: The Problem of Control.

    PubMed

    Kroes, Peter

    2016-06-01

    My aim is to question whether the introduction of new technologies in society may be considered to be genuine experiments. I will argue that they are not, at least not in the sense in which the notion of experiment is being used in the natural and social sciences. If the introduction of a new technology in society is interpreted as an experiment, then we are dealing with a notion of experiment that differs in an important respect from the notion of experiment as used in the natural and social sciences. This difference shows itself most prominently when the functioning of the new technological system is not only dependent on technological hardware but also on social 'software', that is, on social institutions such as appropriate laws, and actions of operators of the new technological system. In those cases we are not dealing with 'simply' the introduction of a new technology, but with the introduction of a new socio-technical system. I will argue that if the introduction of a new socio-technical system is considered to be an experiment, then the relation between the experimenter and the system on which the experiment is performed differs significantly from the relation in traditional experiments in the natural and social sciences. In the latter experiments it is assumed that the experimenter is not part of the experimental system and is able to intervene in and control the experimental system from the outside. With regard to the introduction of new socio-technical systems the idea that there is an experimenter outside the socio-technical system who intervenes in and controls that system becomes problematic. From that perspective we are dealing with a different kind of experiment. PMID:25702146

  11. Strike Point Control for the National Spherical Torus Experiment (NSTX)

    SciTech Connect

    Kolemen, E.; Gates, D. A.; Rowley, C. W.; Kasdin, N. J.; Kallman, J.; Gerhardt, S.; Soukhanovskii, V.; Mueller, D.

    2010-07-09

    This paper presents the first control algorithm for the inner and outer strike point position for a Spherical Torus (ST) fusion experiment and the performance analysis of the controller. A liquid lithium divertor (LLD) will be installed on NSTX which is believed to provide better pumping than lithium coatings on carbon PFCs. The shape of the plasma dictates the pumping rate of the lithium by channeling the plasma to LLD, where strike point location is the most important shape parameter. Simulations show that the density reduction depends on the proximity of strike point to LLD. Experiments were performed to study the dynamics of the strike point, design a new controller to change the location of the strike point to desired location and stabilize it. The most effective PF coils in changing inner and outer strike points were identified using equilibrium code. The PF coil inputs were changed in a step fashion between various set points and the step response of the strike point position was obtained. From the analysis of the step responses, PID controllers for the strike points were obtained and the controller was tuned experimentally for better performance. The strike controller was extended to include the outer-strike point on the inner plate to accommodate the desired low outer-strike points for the experiment with the aim of achieving "snowflake" divertor configuration in NSTX.

  12. Additional follow-up telephone counselling and initial smoking relapse: a longitudinal, controlled study

    PubMed Central

    Wu, Lei; He, Yao; Jiang, Bin; Zuo, Fang; Liu, Qinghui; Zhang, Li; Zhou, Changxi

    2016-01-01

    Objectives Smoking cessation services can help smokers to quit; however, many smoking relapse cases occur over time. Initial relapse prevention should play an important role in achieving the goal of long-term smoking cessation. Several studies have focused on the effect of extended telephone support in relapse prevention, but the conclusions remain conflicting. Design and setting From October 2008 to August 2013, a longitudinal, controlled study was performed in a large general hospital of Beijing. Participants The smokers who sought treatment at our smoking cessation clinic were non-randomised and divided into 2 groups: face-to-face individual counselling group (FC group), and face-to-face individual counselling plus telephone follow-up counselling group (FCF group). No pharmacotherapy was offered. Outcomes The timing of initial smoking relapse was compared between FC and FCF groups. Predictors of initial relapse were investigated during the first 180 days, using the Cox proportional hazards model. Results Of 547 eligible male smokers who volunteered to participate, 457 participants (117 in FC group and 340 in FCF group) achieved at least 24 h abstinence. The majority of the lapse episodes occurred during the first 2 weeks after the quit date. Smokers who did not receive the follow-up telephone counselling (FC group) tended to relapse to smoking earlier than those smokers who received the additional follow-up telephone counselling (FCF group), and the log-rank test was statistically significant (p=0.003). A Cox regression model showed that, in the FCF group, being married, and having a lower Fagerström test score, normal body mass index and doctor-diagnosed tobacco-related chronic diseases, were significantly independent protective predictors of smoking relapse. Conclusions Within the limitations of this study, it can be concluded that additional follow-up telephone counselling might be an effective strategy in preventing relapse. Further research is still

  13. Analysis of Time to Event Outcomes in Randomized Controlled Trials by Generalized Additive Models

    PubMed Central

    Argyropoulos, Christos; Unruh, Mark L.

    2015-01-01

    Background Randomized Controlled Trials almost invariably utilize the hazard ratio calculated with a Cox proportional hazard model as a treatment efficacy measure. Despite the widespread adoption of HRs, these provide a limited understanding of the treatment effect and may even provide a biased estimate when the assumption of proportional hazards in the Cox model is not verified by the trial data. Additional treatment effect measures on the survival probability or the time scale may be used to supplement HRs but a framework for the simultaneous generation of these measures is lacking. Methods By splitting follow-up time at the nodes of a Gauss Lobatto numerical quadrature rule, techniques for Poisson Generalized Additive Models (PGAM) can be adopted for flexible hazard modeling. Straightforward simulation post-estimation transforms PGAM estimates for the log hazard into estimates of the survival function. These in turn were used to calculate relative and absolute risks or even differences in restricted mean survival time between treatment arms. We illustrate our approach with extensive simulations and in two trials: IPASS (in which the proportionality of hazards was violated) and HEMO a long duration study conducted under evolving standards of care on a heterogeneous patient population. Findings PGAM can generate estimates of the survival function and the hazard ratio that are essentially identical to those obtained by Kaplan Meier curve analysis and the Cox model. PGAMs can simultaneously provide multiple measures of treatment efficacy after a single data pass. Furthermore, supported unadjusted (overall treatment effect) but also subgroup and adjusted analyses, while incorporating multiple time scales and accounting for non-proportional hazards in survival data. Conclusions By augmenting the HR conventionally reported, PGAMs have the potential to support the inferential goals of multiple stakeholders involved in the evaluation and appraisal of clinical trial

  14. Whole-lake nitrate addition for control of methylmercury in mercury-contaminated Onondaga Lake, NY.

    PubMed

    Matthews, David A; Babcock, David B; Nolan, John G; Prestigiacomo, Anthony R; Effler, Steven W; Driscoll, Charles T; Todorova, Svetoslava G; Kuhr, Kenneth M

    2013-08-01

    Methylmercury (MeHg) strongly bioaccumulates in aquatic food webs resulting in exposure to humans and wildlife through consumption of fish. Production of MeHg is promoted by anaerobic conditions and the supply of inorganic Hg (Hg(2+)), sulfate (SO4(2-)), and labile organic carbon. The anaerobic sediments of stratified lakes are particularly active zones for methylation of Hg(2+) and can be an important source of MeHg to the water column during summer anoxia and fall turnover. Nitrate (NO3(-)) addition has recently been proposed as a novel approach for the control of MeHg accumulation in the hypolimnia of Hg-contaminated lakes. In 2011, a whole-lake NO3(-) addition pilot test was conducted in Hg-contaminated Onondaga Lake, NY with the objective of limiting release of MeHg from the pelagic sediments to the hypolimnion through maintenance of NO3(-)-N concentrations >1mgN/L. A liquid calcium-nitrate solution was added to the hypolimnion as a neutrally buoyant plume approximately three times per week during the summer stratification interval. Maximum hypolimnetic concentrations of MeHg and soluble reactive phosphorus (SRP) decreased 94% and 95% from 2009 levels, suggesting increased sorption to Fe and Mn oxyhydroxides in surficial sediments as the regulating mechanism. Increased MeHg concentrations in the upper waters during fall turnover, which had been a generally recurring pattern, did not occur in 2011, resulting in decreased exposure of aquatic organisms to MeHg. Over the 1992-2011 interval, the hypolimnetic NO3(-) supply explained 85% and 95% of the interannual variations in hypolimnetic accumulations of SRP and MeHg, respectively. PMID:23683521

  15. Structural control research and experiments at NASA/LaRC

    NASA Technical Reports Server (NTRS)

    Montgomery, R. C.

    1983-01-01

    The advances made in the area of structural dynamics and control using the flexible beam facility at the NASA Langley Research Center are surveyed. Spectral attention is given to the progress in adaptive control and reliability improvements using advanced control concepts. Both theoretical and experimental results are given to delineate the nature of the work being undertaken. With regard to adaptive control, emphasis is placed on parameter and system identification and on comparisons between competing on-line algorithms. In addition, results are presented for on-line modal control laws that are interfaced to a parameter identification scheme. This gives an on-line distributed adaptive control system. With regard to reliability, a design process is outlined that incorporates reliability over the design mission life.

  16. Modifications to the Langley 8-foot transonic pressure tunnel for the laminar flow control experiment

    NASA Technical Reports Server (NTRS)

    Harris, Charles D.; Brooks, Cuyler W., Jr.

    1988-01-01

    Modifications to the NASA Langley 8 Foot Transonic Pressure Tunnel in support of the Lamina Flow Control (LFC) Experiment included the installation of a honeymoon and five screens in the settling chamber upstream of the test section 41-long test section liner that extended from the upstream end of the test section contraction region, through the best section, and into the diffuser. The honeycomb and screens were installed as permanent additions to the facility, and the liner was a temporary addition to be removed at the conclusion of the LFC Experiment. These modifications are briefly described.

  17. CONTROL OF MOTOR VEHICLE EMISSIONS - THE U.S. EXPERIENCE

    EPA Science Inventory

    An historical overview of the U.S. experience with controlling emissions from highway motor vehicles is presented. he evolution of new motor vehicle emissions certification practice, end-of-assembly-line inspection, in-use surveillance and recall, inspection and maintenance, and ...

  18. Equations of motion for control of the SCOLE laboratory experiment

    NASA Technical Reports Server (NTRS)

    Meirovitch, L.; Quinn, R. D.; Norris, M. A.

    1984-01-01

    The objectives of this study are listed as follows: (1) to develop Lagrange's equations of motion for the shuttle antenna configuration in orbit; (2) to modify equations using the Lagrange multiplier method to develop equations of motion for the laboratory experiment; and (3) to discuss methods for simulation and control. The equations are presented in graph form.

  19. SMOG CHAMBER EXPERIMENTS TO TEST OXIDANT RELATED CONTROL STRATEGY ISSUES

    EPA Science Inventory

    Outdoor smog chamber experiments were performed to address various issues relating to ozone (O3) production and oxidant control strategies. Temperature effects on single hydrocarbon-NOx systems were studied. Propylene-NOx systems were modeled with particular attention to peroxyni...

  20. Unconscious Modulation of the Conscious Experience of Voluntary Control

    ERIC Educational Resources Information Center

    Linser, Katrin; Goschke, Thomas

    2007-01-01

    How does the brain generate our experience of being in control over our actions and their effects? Here, we argue that the perception of events as self-caused emerges from a comparison between anticipated and actual action-effects: if the representation of an event that follows an action is activated before the action, the event is experienced as…

  1. Controls, astrophysics, and structures experiment in space ground test facility

    NASA Technical Reports Server (NTRS)

    Bukley, Angelia P.; Jones, Victoria L.

    1992-01-01

    This paper describes the initial configuration of the NASA Marshall Space Flight Center (MSFC) Controls/Structures Interaction Advanced Development Facility (CSI ADF), which is a ground test facility (GTF) for the proposed Controls, Astrophysics, and Structures Experiment in Space (CASES). The laboratory has been developed for the purpose of implementing, testing, and evaluating CSI modeling, control system design, failure analysis, and system identification techniques on a representative large space structure. The facility has been configured to represent as closely as possible an actual flight article.

  2. The SNS Cryogenic Control System: Experiences in Collaboration

    SciTech Connect

    W.H. Strong; P.A. Gurd; J.D. Creel; B.S. Bevins

    2001-11-01

    The cryogenic system for the Spallation Neutron Source (SNS) is designed by Jefferson Laboratory (JLab) personnel and is based on the existing JLab facility. Our task is to use the JLab control system design [2] as much as practical while remaining consistent with SNS control system standards. Some aspects of the systems are very similar, including equipment to be controlled, the need for PID loops and automatic sequences,and the use of EPICS. There are differences in device naming, system hardware, and software tools. The cryogenic system is the first SNS system to be developed using SNS standards. This paper reports on our experiences in integrating the new and the old.

  3. Controlling the corrosion and cathodic activation of magnesium via microalloying additions of Ge

    PubMed Central

    Liu, R. L.; Hurley, M. F.; Kvryan, A.; Williams, G.; Scully, J. R.; Birbilis, N.

    2016-01-01

    The evolution of corrosion morphology and kinetics for magnesium (Mg) have been demonstrated to be influenced by cathodic activation, which implies that the rate of the cathodic partial reaction is enhanced as a result of anodic dissolution. This phenomenon was recently demonstrated to be moderated by the use of arsenic (As) alloying as a poison for the cathodic reaction, leading to significantly improved corrosion resistance. The pursuit of alternatives to toxic As is important as a means to imparting a technologically safe and effective corrosion control method for Mg (and its alloys). In this work, Mg was microalloyed with germanium (Ge), with the aim of improving corrosion resistance by retarding cathodic activation. Based on a combined analysis herein, we report that Ge is potent in supressing the cathodic hydrogen evolution reaction (reduction of water) upon Mg, improving corrosion resistance. With the addition of Ge, cathodic activation of Mg subject to cyclic polarisation was also hindered, with beneficial implications for future Mg electrodes. PMID:27350286

  4. Controlling the corrosion and cathodic activation of magnesium via microalloying additions of Ge.

    PubMed

    Liu, R L; Hurley, M F; Kvryan, A; Williams, G; Scully, J R; Birbilis, N

    2016-01-01

    The evolution of corrosion morphology and kinetics for magnesium (Mg) have been demonstrated to be influenced by cathodic activation, which implies that the rate of the cathodic partial reaction is enhanced as a result of anodic dissolution. This phenomenon was recently demonstrated to be moderated by the use of arsenic (As) alloying as a poison for the cathodic reaction, leading to significantly improved corrosion resistance. The pursuit of alternatives to toxic As is important as a means to imparting a technologically safe and effective corrosion control method for Mg (and its alloys). In this work, Mg was microalloyed with germanium (Ge), with the aim of improving corrosion resistance by retarding cathodic activation. Based on a combined analysis herein, we report that Ge is potent in supressing the cathodic hydrogen evolution reaction (reduction of water) upon Mg, improving corrosion resistance. With the addition of Ge, cathodic activation of Mg subject to cyclic polarisation was also hindered, with beneficial implications for future Mg electrodes. PMID:27350286

  5. Performance of active vibration control technology: the ACTEX flight experiments

    NASA Astrophysics Data System (ADS)

    Nye, T. W.; Manning, R. A.; Qassim, K.

    1999-12-01

    This paper discusses the development and results of two intelligent structures space-flight experiments, each of which could affect architecture designs of future spacecraft. The first, the advanced controls technology experiment I (ACTEX I), is a variable stiffness tripod structure riding as a secondary payload on a classified spacecraft. It has been operating well past its expected life since becoming operational in 1996. Over 60 on-orbit experiments have been run on the ACTEX I flight experiment. These experiments form the basis for in-space controller design problems and for concluding lifetime/reliability data on the active control components. Transfer functions taken during the life of ACTEX I have shown consistent predictability and stability in structural behavior, including consistency with those measurements taken on the ground prior to a three year storage period and the launch event. ACTEX I can change its modal characteristics by employing its dynamic change mechanism that varies preloads in portions of its structure. Active control experiments have demonstrated maximum vibration reductions of 29 dB and 16 dB in the first two variable modes of the system, while operating over a remarkable on-orbit temperature range of -80 °C to 129 °C. The second experiment, ACTEX II, was successfully designed, ground-tested, and integrated on an experimental Department of Defense satellite prior to its loss during a launch vehicle failure in 1995. ACTEX II also had variable modal behavior by virtue of a two-axis gimbal and added challenges of structural flexibility by being a large deployable appendage. Although the loss of ACTEX II did not provide space environment experience, ground testing resulted in space qualifying the hardware and demonstrated 21 dB, 14 dB, and 8 dB reductions in amplitude of the first three primary structural modes. ACTEX II could use either active and/or passive techniques to affect vibration suppression. Both experiments trailblazed

  6. Skylab D024 thermal control coatings and polymeric films experiment

    NASA Technical Reports Server (NTRS)

    Lehn, William L.; Hurley, Charles J.

    1992-01-01

    The Skylab D024 Thermal Control Coatings and Polymeric Films Experiment was designed to determine the effects of the external Skylab space environment on the performance and properties of a wide variety of selected thermal control coatings and polymeric films. Three duplicate sets of thermal control coatings and polymeric films were exposed to the Skylab space environment for varying periods of time during the mission. The specimens were retrieved by the astronauts during extravehicular activities (EVA) and placed in hermetically sealed return containers, recovered, and returned to the Wright Laboratory/Materials Laboratory/WPAFB, Ohio for analysis and evaluation. Postflight analysis of the three sets of recovered thermal control coatings indicated that measured changes in specimen thermo-optical properties were due to a combination of excessive contamination and solar degradation of the contaminant layer. The degree of degradation experienced over-rode, obscured, and compromised the measurement of the degradation of the substrate coatings themselves. Results of the analysis of the effects of exposure on the polymeric films and the contamination observed are also presented. The D024 results were used in the design of the LDEF M0003-5 Thermal Control Materials Experiment. The results are presented here to call to the attention of the many other LDEF experimenters the wealth of directly related, low earth orbit, space environmental exposure data that is available from the ten or more separate experiments that were conducted during the Skylab mission. Results of these experiments offer data on the results of low altitude space exposure on materials recovered from space with exposure longer than typical STS experiments for comparison with the LDEF results.

  7. Slew maneuvers of Spacecraft Control Laboratory Experiment (SCOLE)

    NASA Technical Reports Server (NTRS)

    Kakad, Yogendra P.

    1992-01-01

    This is the final report on the dynamics and control of slew maneuvers of the Spacecraft Control Laboratory Experiment (SCOLE) test facility. The report documents the basic dynamical equation derivations for an arbitrary large angle slew maneuver as well as the basic decentralized slew maneuver control algorithm. The set of dynamical equations incorporate rigid body slew maneuver and three dimensional vibrations of the complete assembly comprising the rigid shuttle, the flexible beam, and the reflector with an offset mass. The analysis also includes kinematic nonlinearities of the entire assembly during the maneuver and the dynamics of the interactions between the rigid shuttle and the flexible appendage. The equations are simplified and evaluated numerically to include the first ten flexible modes to yield a model for designing control systems to perform slew maneuvers. The control problem incorporates the nonlinear dynamical equations and is expressed in terms of a two point boundary value problem.

  8. Apollo experience report: Lunar module environmental control subsystem

    NASA Technical Reports Server (NTRS)

    Gillen, R. J.; Brady, J. C.; Collier, F.

    1972-01-01

    A functional description of the environmental control subsystem is presented. Development, tests, checkout, and flight experiences of the subsystem are discussed; and the design fabrication, and operational difficulties associated with the various components and subassemblies are recorded. Detailed information is related concerning design changes made to, and problems encountered with, the various elements of the subsystem, such as the thermal control water sublimator, the carbon dioxide sensing and control units, and the water section. The problems associated with water sterilization, water/glycol formulation, and materials compatibility are discussed. The corrective actions taken are described with the expection that this information may be of value for future subsystems. Although the main experiences described are problem oriented, the subsystem has generally performed satisfactorily in flight.

  9. Space flight experience with the Shuttle Orbiter control system

    NASA Technical Reports Server (NTRS)

    Cox, K. J.; Daly, K. C.; Hattis, P. D.

    1983-01-01

    Experience gained through the Shuttle Orbital Flight Test program has matured the engineering understanding of the Shuttle on-orbit control system. The geneology of the control systems (called digital autopilots, or DAPs, and used by the Shuttle for on-orbit operations) is reviewed, the flight experience gained during the flight test program is examined within the context of preflight analysis and test results, and issues for the operational phase of the Shuttle, including constraints upon both operations and analysis still required to increase confidence in the Shuttle's ability to handle capabilities not experienced during the flight test program are addressed. Two orbital autopilots have resulted from computer memory and time constraints on a flight control system, with many different, flight phase unique requirements. The transition DAP, used for insertion and deorbit, has more active sensors and redundancy but a less complex data processing scheme excluding state estimation with fewer choices of operational mode.

  10. [Tobacco control: an intersectorial experience in Tunja (Colombia)].

    PubMed

    Panader-Torres, Adriana; Agudelo-Cely, Nancy Aurora; Bolívar-Suárez, Yolima; Cárdenas-Cárdenas, Luz Mery

    2014-01-01

    Tobacco control in Colombia is regulated by Law 1335 of 2009. The implementation and monitoring of the provisions of this law require strengthening of intersectorial work at the local level. This field note presents an intersectorial work experience that was carried out in the municipality of Tunja (Colombia) to improve tobacco control. The Respirarte Group was established. This group consists of an intersectorial team composed of 15 institutions. The Respirarte Group achieved the following political and community actions: signing of an agreement on tobacco control by government actors, expedition of a local decree to comply with Law 1335 in the municipality, provision of information and communication, and social mobilization and monitoring. This experience serves as a national and international reference and its lessons could be used in the approach to other public health problems. PMID:25087863

  11. Experimenting from a Distance--Remotely Controlled Laboratory (RCL)

    ERIC Educational Resources Information Center

    Grober, Sebastian; Vetter, Martin; Eckert, Bodo; Jodl, Hans-Jorg

    2007-01-01

    The use of computers and multimedia, as well as the World Wide Web and new communication technologies, allows new forms of teaching and learning such as distance learning, blended learning, use of virtual libraries and many more. The herewith discussed remotely controlled laboratory (RCL) project shall offer an additional contribution. The basic…

  12. Experience with synchronous and asynchronous digital control systems. [for flight

    NASA Technical Reports Server (NTRS)

    Regenie, Victoria A.; Chacon, Claude V.; Lock, Wilton P.

    1986-01-01

    Flight control systems have undergone a revolution since the days of simple mechanical linkages; presently the most advanced systems are full-authority, full-time digital systems controlling unstable aircraft. With the use of advanced control systems, the aerodynamic design can incorporate features that allow greater performance and fuel savings, as can be seen on the new Airbus design and advanced tactical fighter concepts. These advanced aircraft will be and are relying on the flight control system to provide the stability and handling qualities required for safe flight and to allow the pilot to control the aircraft. Various design philosophies have been proposed and followed to investigate system architectures for these advanced flight control systems. One major area of discussion is whether a multichannel digital control system should be synchronous or asynchronous. This paper addressed the flight experience at the Dryden Flight Research Facility of NASA's Ames Research Center with both synchronous and asynchronous digital flight control systems. Four different flight control systems are evaluated against criteria such as software reliability, cost increases, and schedule delays.

  13. Experience with synchronous and asynchronous digital control systems

    NASA Technical Reports Server (NTRS)

    Regenie, V. A.; Chacon, C. V.; Lock, W. P.

    1986-01-01

    Flight control systems have undergone a revolution since the days of simple mechanical linkages; presently the most advanced systems are full-authority, full-time digital systems controlling unstable aircraft. With the use of advanced control systems, the aerodynamic design can incorporate features that allow greater performance and fuel savings, as can be seen on the new Airbus design and advanced tactical fighter concepts. These advanced aircraft will be and are relying on the flight control system to provide the stability and handling qualities required for safe flight and to allow the pilot to control the aircraft. Various design philosophies have been proposed and followed to investigate system architectures for these advanced flight control systems. One major area of discussion is whether a multichannel digital control system should be synchronous or asynchronous. This paper addressed the flight experience at the Dryden Flight Research Facility of NASA's Ames Research Center with both synchronous and asynchronous digital flight control systems. Four different flight control systems are evaluated against criteria such as software reliability, cost increases, and schedule delays.

  14. A controlled experiment to evaluate the impact of summer research experiences on attitudes towards science in high school aged students

    NASA Astrophysics Data System (ADS)

    White, M. A.; Tcherednichenko, I.; Hamar, M.; Taylor, M. J.; Litizzette, L.

    2006-12-01

    United States funding agencies increasingly are supporting activities designed to increase the enrollment of United States high school students in science, math, or engineering careers. However, in many cases, the likely outcomes of educational activities are unknown. A common approach within the physical and natural sciences is to provide high school aged students with a summer research experience, with the expectation that such experiences will increase student interest in science, possibly as a career choice. With funding support from the National Aeronautics and Space Administration New Investigator Grant program, we conducted a controlled experiment to test this assumption. In collaboration with Mountain Crest High School in Logan, UT, we recruited 40 students currently enrolled in science courses, assessed attitudes towards science (with informed consent), and randomly assigned 20 students to a control group and 20 students to an experimental group. Students in the experimental group were paired with faculty and graduate students in a wide range of field and laboratory research groups in natural resources and biology. Students were employed in at least two different research groups for an average of 30-40 hours per week for eight weeks in the summer of 2006. Following the completion of the summer work experience, we again assessed attitudes towards science in both groups and gathered additional information from the experimental group on satisfaction with the work experience and reasons for participating. Results are presented and discussed.

  15. Enhancing schistosomiasis control strategy for zimbabwe: building on past experiences.

    PubMed

    Chimbari, Moses J

    2012-01-01

    Schistosoma haematobium and Schistosoma mansoni are prevalent in Zimbabwe to levels that make schistosomiasis a public health problem. Following three national surveys to map the disease prevalence, a national policy on control of schistosomiasis and soil transmitted helminths is being developed. This paper reviews the experiences that Zimbabwe has in the area of schistosomiasis control with a view to influence policy. A case study approach to highlight key experiences and outcomes was adopted. The benefits derived from intersectoral collaboration that led to the development of a model irrigation scheme that incorporates schistosomiasis control measures are highlighted. Similarly, the benefits of using plant molluscicides and fish and duck biological agents (Sargochromis codringtonii and Cairina moschata) are highlighted. Emphasis was also placed on the importance of utilizing locally developed water and sanitation technologies and the critical human resource base in the area of schistosomiasis developed over years. After synthesis of the case studies presented, it was concluded that while there is a need to follow the WHO recommended guidelines for schistosomiasis control it is important to develop a control strategy that is informed by work already done in the country. The importance of having a policy and local guidelines for schistosomiasis control is emphasized. PMID:22655171

  16. Applications of small computers for systems control on the Tandem Mirror Experiment-Upgrade

    SciTech Connect

    Bork, R.G.; Kane, R.J.; Moore, T.L.

    1983-11-29

    Desktop computers operating into a CAMAC-based interface are used to control and monitor the operation of the various subsystems on the Tandem Mirror Experiment-Upgrade (TMX-U) at Lawrence Livermore National Laboratory (LLNL). These systems include: shot sequencer/master timing, neutral beam control (four consoles), magnet power system control, ion-cyclotron resonant heating (ICRH) control, thermocouple monitoring, getter system control, gas fueling system control, and electron-cyclotron resonant heating (ECRH) monitoring. Two additional computers are used to control the TMX-U neutral beam test stand and provide computer-aided repair/test and development of CAMAC modules. These machines are usually programmed in BASIC, but some codes have been interpreted into assembly language to increase speed. Details of the computer interfaces and system complexity are described as well as the evolution of the systems to their present states.

  17. Control and monitoring of oxygen fugacity in piston cylinder experiments

    NASA Astrophysics Data System (ADS)

    Matjuschkin, Vladimir; Brooker, Richard A.; Tattitch, Brian; Blundy, Jon D.; Stamper, Charlotte C.

    2015-01-01

    We present a newly developed capsule design that resolves some common problems associated with the monitoring and control of oxygen fugacity ( fO2) in high-pressure piston cylinder experiments. The new fO2 control assembly consists of an AuPd outer capsule enclosing two inner capsules: one of AuPd capsule containing the experimental charge (including some water), and the other of Pt containing a solid oxygen buffer plus water. The inner capsules are separated by crushable alumina. The outer capsule is surrounded by a Pyrex sleeve to simultaneously minimise hydrogen loss from the cell and carbon infiltration from the graphite furnace. Controlled fO2 experiments using this cell design were carried out at 1.0 GPa and 1,000 °C. We used NiPd, CoPd and (Ni, Mg)O fO2 sensors, whose pressure sensitivity is well calibrated, to monitor the redox states achieved in experiments buffered by Re-ReO2, Ni-NiO and Co-CoO, respectively. Results for the fO2 sensors are in good agreement with the intended fO2 established by the buffer, demonstrating excellent control for durations of 24-48 h, with uncertainties less than ± 0.3 log bar units of fO2.

  18. Field experiments using SPEAR: a speech control system for UGVs

    NASA Astrophysics Data System (ADS)

    Chhatpar, Siddharth R.; Blanco, Chris; Czerniak, Jeffrey; Hoffman, Orin; Juneja, Amit; Pruthi, Tarun; Liu, Dongqing; Karlsen, Robert; Brown, Jonathan

    2009-05-01

    This paper reports on a Field Experiment carried out by the Human Research and Engineering Directorate at Ft. Benning to evaluate the efficacy of using speech to control an Unmanned Ground Vehicle (UGV) concurrently with a handcontroller. The SPEAR system, developed by Think-A-Move, provides speech-control of UGVs. The system picks up user-speech in the ear canal with an in-ear microphone. This property allows it to work efficiently in high-noise environments, where traditional speech systems, employing external microphones, fail. It has been integrated with an iRobot PackBot 510 with EOD kit. The integrated system allows the hand-controller to be supplemented with speech for concurrent control. At Ft. Benning, the integrated system was tested by soldiers from the Officer Candidate School. The Experiment had dual focus: 1) Quantitative measurement of the time taken to complete each station and the cognitive load on users; 2) Qualitative evaluation of ease-of-use and ergonomics through soldier-feedback. Also of significant benefit to Think-A-Move was soldier-feedback on the speech-command vocabulary employed: What spoken commands are intuitive, and how the commands should be executed, e.g., limited-motion vs. unlimited-motion commands. Overall results from the Experiment are reported in the paper.

  19. Instrument Control and Data Acquisition for NMR Experiments

    1999-03-29

    This is a software program which is intended to do some instrument control and data acquisition for NMR experiments. The basic purpose of the program is to allow a user of the NMR system to create a list of instructions which tells the program what steps should be done, the stat the data taking program and let the system run by itself (depending on the type of sample and the type of experiment being run,more » it can take from several minutes to many hours to do a data collection run).« less

  20. An active thermal control surfaces experiment. [spacecraft temperature determination

    NASA Technical Reports Server (NTRS)

    Wilkes, D. R.; Brown, M. J.

    1979-01-01

    An active flight experiment is described that has the objectives to determine the effects of the low earth natural environment and the Shuttle induced environment on selected thermal control and optical surfaces. The optical and thermal properties of test samples will be measured in-situ using an integrating sphere reflectrometer and using calorimetric methods. This experiment has been selected for the Long Duration Exposure Facility (LDEF) flight which will be carried to orbit by the NASA Space Shuttle. The LDEF will remain in orbit to be picked up by a later Shuttle mission and returned for postflight evaluation.

  1. EURECA mission control experience and messages for the future

    NASA Technical Reports Server (NTRS)

    Huebner, H.; Ferri, P.; Wimmer, W.

    1994-01-01

    EURECA is a retrievable space platform which can perform multi-disciplinary scientific and technological experiments in a Low Earth Orbit for a typical mission duration of six to twelve months. It is deployed and retrieved by the NASA Space Shuttle and is designed to support up to five flights. The first mission started at the end of July 1992 and was successfully completed with the retrieval in June 1993. The operations concept and the ground segment for the first EURECA mission are briefly introduced. The experiences in the preparation and the conduction of the mission from the flight control team point of view are described.

  2. A feasibility study regarding the addition of a fifth control to a rotorcraft in-flight simulator

    NASA Technical Reports Server (NTRS)

    Turner, Simon; Andrisani, Dominick, II

    1992-01-01

    The addition of a large movable horizontal tail surface to the control system of a rotorcraft in-flight simulator being developed from a Sikorsky UH-60A Black Hawk Helicopter is evaluated. The capabilities of the control surface as a trim control and as an active control are explored. The helicopter dynamics are modeled using the Generic Helicopter simulation program developed by Sikorsky Aircraft. The effect of the horizontal tail on the helicopter trim envelope is examined by plotting trim maps of the aircraft attitude and controls as a function of the flight speed and horizontal tail incidence. The control power of the tail surface relative to that of the other controls is examined by comparing control derivatives extracted from the simulation program over the flight speed envelope. The horizontal tail's contribution as an active control is evaluated using an explicit model following control synthesis involving a linear model of the helicopter in steady, level flight at a flight speed of eighty knots. The horizontal tail is found to provide additional control flexibility in the longitudinal axis. As a trim control, it provides effective control of the trim pitch attitude at mid to high forward speeds. As an active control, the horizontal tail provides useful pitching moment generating capabilities at mid to high forward speeds.

  3. Review and evaluation of literature on testing of chemical additives for scale control in geothermal fluids. Final report

    SciTech Connect

    Crane, C.H.; Kenkeremath, D.C.

    1981-01-01

    A selected group of reported tests of chemical additives in actual geothermal fluids are reviewed and evaluated to summarize the status of chemical scale-control testing and identify information and testing needs. The task distinguishes between scale control in the cooling system of a flash plant and elsewhere in the utilization system due to the essentially different operating environments involved. Additives for non-cooling geothermal fluids are discussed by scale type: silica, carbonate, and sulfide.

  4. Apollo experience report: Command and service module environmental control system

    NASA Technical Reports Server (NTRS)

    Samonski, F. H., Jr.; Tucker, E. M.

    1972-01-01

    A comprehensive review is presented of the design philosophy of the Apollo environmental control system together with the development history of the total system and of selected components within the system. In particular, discussions are presented relative to the development history and to the problems associated with the equipment cooling coldplates, the evaporator and its electronic control system, and the space radiator system used for rejection of the spacecraft thermal loads. Apollo flight experience and operational difficulties associated with the spacecraft water system and the waste management system are discussed in detail to provide definition of the problem and the corrective action taken when applicable.

  5. Experiments with a small behaviour controlled planetary rover

    NASA Technical Reports Server (NTRS)

    Miller, David P.; Desai, Rajiv S.; Gat, Erann; Ivlev, Robert; Loch, John

    1993-01-01

    A series of experiments that were performed on the Rocky 3 robot is described. Rocky 3 is a small autonomous rover capable of navigating through rough outdoor terrain to a predesignated area, searching that area for soft soil, acquiring a soil sample, and depositing the sample in a container at its home base. The robot is programmed according to a reactive behavior control paradigm using the ALFA programming language. This style of programming produces robust autonomous performance while requiring significantly less computational resources than more traditional mobile robot control systems. The code for Rocky 3 runs on an eight bit processor and uses about ten k of memory.

  6. Implementation of BN Control in the National Spherical Torus Experiment

    SciTech Connect

    Gerhardt, S; Bell, M G; Cropper, M; Gates, D A; Koleman, E; Lawson, J; Marsala, B; Menard, J E; Mueller, D

    2012-09-15

    We have designed and constructed a system for control of the normalized B in the National Spherical Torus Experiment [M. Ono, et al., Nuclear Fusion 40, 557 (2000)]. A PID operator is applied to the difference between the present value of B N (from realtime equilibrium reconstruction) and a time-dependent request, in order to calculate the required injected power. This injected power request is then turned into modulations of the neutral beams. The details of this algorithm are described, including the techniques used to develop the appropriate control gains. Example uses of the system are shown

  7. 40 CFR 82.18 - Availability of production in addition to baseline production allowances for class II controlled...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....20 in order to produce with the additional production allowances. (2) Trade from a Party—Information... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Availability of production in addition to baseline production allowances for class II controlled substances. 82.18 Section 82.18...

  8. The payload control unit - An advanced experiment control and data management system

    NASA Astrophysics Data System (ADS)

    Beretta, A.; di Tolle, F.; Ranieri, R.

    1988-10-01

    The development of the Payload Control Unit (PCU) as part of the In-Orbit Technology Demonstration Program is discussed. The PCU is an on-board computer designed to control experiments and support systems. The general architecture of the PCU and the development of software for the PCU are examined.

  9. Controlled ecological life support system higher plant flight experiments

    NASA Technical Reports Server (NTRS)

    Tibbitts, T. W.; Wheeler, R. M.

    1984-01-01

    Requirements for spaceflight experments which involve higher plants were determined. The plants are studied for use in controlled ecological life support systems (CELSS). Two categories of research requirements are discussed: (1) the physical needs which include nutrient, water and gas exchange requirements; (2) the biological and physiological functions which affect plants in zero gravity environments. Physical problems studies are given the priority since they affect all biological experiments.

  10. The JPL telerobot operator control station: Operational experiences

    NASA Technical Reports Server (NTRS)

    Kan, Edwin P.

    1990-01-01

    The Operator Control Station of the JPL/NASA Telerobot Demonstration System provides an efficient man-machine interface for the performance of telerobot tasks. Its hardware and software have been designed with high flexibility. It provides a feedback-rich interactive environment in which the Operator performs teleoperation tasks, robotic tasks, and telerobotic tasks with ease. The to-date operational experiences of this system, particularly related to the Object Designate Process and the Voice Input/Output Process are discussed.

  11. Dynamics and control simulation of the Spacelab Experiment Pointing Mount

    NASA Technical Reports Server (NTRS)

    Marsh, E. L.; Ward, R. S.

    1977-01-01

    Computer simulations were developed to evaluate the performance of four Experiment Pointing Mounts (EPM) being considered for Spacelab experiments in the 1980-1990 time frame. The system modeled compromises a multibody system consisting of the shuttle, a mechanical isolation device, the EPM, celestial and inertial sensors, bearings, gimbal torque motors and associated nonlinearities, the experiment payload, and control and estimator algorithms. Each mount was subjected to a common disturbance (shuttle vernier thruster firing and man push off) and command (stellar pointing or solar raster scan) input. The fundamental limitation common to all mounts was found to be sensor noise. System dynamics and hardware nonlinearities have secondary effects on pointing performance for sufficiently high bandwidth.

  12. IRIS Controlled Source Seismic Experiments: Continental Structure, Instrumentation, and Education

    NASA Astrophysics Data System (ADS)

    Mooney, W. D.; Keller, G. R.

    2004-12-01

    The controlled-source seismology program of IRIS/PASSCAL has made major contributions to the study of continental structure and evolution. It has also undergone major developments in seismic instrumentation. The first PASSCAL experiments (1984/85) targeted the Basin and Range Province and the Ouachita orogenic belt. The Basin and Range study provided remarkably clear images of this thin, highly-extended crust, while the Ouachita experiment tested competing hypotheses for the deep structure of this Paleozoic orogen. However, both of these projects were limited by a lack of seismic instruments. The situation improved in the late 1980's with the benefit of a mixed array of 600 seismic recorders from the USGS, Stanford, and the Geological Survey of Canada. The resolution achieved with these instruments was revolutionary. Results include the imaging of such remarkable features as crustal-scale duplexes in the Brooks Range compressional orogen of northern Alaska, and of crustal "core complexes" in the extended crust of southwest Arizona. The 3-channel PASSCAL Jr. instrument was developed, leading to experiments in which ˜1000 instruments were deployed, including three-component recording. This complex mix of instruments served the community well for several years, but required large, complex instrument centers and lots of technical support. With input from PASSCAL and the international community, a newly designed, compact instrument (the Texan) was finalized in the spring of 1998, and the first 200 instruments was delivered to the Univ. of Texas-El Paso in late 1998. The present instrument pool of Texans exceeds 1,400 and these have been used on such projects as the high-resolution imaging of the Los Angeles and San Fernando basins (LARSE I and II experiments), where active thrust faults have been imaged. Controlled-source seismic experiments are now very numerous. During calendar year 2004 alone, portable Texan instruments have traveled from Venezuela to Denmark

  13. Food Additives and Hyperkinesis: A Controlled Double-Blind Experiment. (Includes NIE Staff Critique).

    ERIC Educational Resources Information Center

    Conners, C. Keith; And Others

    Fifteen hyperkinetic children (6-12 years old) were involved in a pilot study to test B. Feingold's hypothesis that hyperkinesis may be caused by artificial flavors and colors in food. Prior to treatment, parents and teachers completed bi-weekly questionnaires regarding each Ss' behavior both on medication (pretreatment period) and when medication…

  14. Nest of Origin Predicts Adult Neuron Addition Rates in the Vocal Control System of the Zebra Finch

    PubMed Central

    Hurley, Patrick; Pytte, Carolyn; Kirn, John R.

    2008-01-01

    Neurogenesis and neuronal replacement in adulthood represent dramatic forms of plasticity that might serve as a substrate for behavioral flexibility. In songbirds, neurons are continually replaced in HVC (used as a proper name), a pre-motor region necessary for the production of learned vocalizations. There are large individual differences in HVC neuron addition. Some of this variation is probably due to individual differences in adult experience; however, it is also possible that heritability or experience early in development constrains the levels of adult neuron addition. As a step toward addressing the latter two possibilities, we explored the extent to which nest of origin predicts rates of HVC neuron addition in adult male zebra finches. One month after injections of [3H]-thymidine to mark dividing cells, neuron addition in HVC was found to co-vary among birds that had been nest mates, even when they were housed in different cages as adults. We also tested whether nest mate co-variation might be due to shared adult auditory experience by measuring neuron addition in nest mate pairs after one member was deafened. There were significant differences in neuron addition between hearing and deaf birds but nest mate relationships persisted. These results suggest that variation in genotype and/or early pre- or postnatal experience can account for a large fraction of adult variation in rates of neuron addition. These results also suggest that a major constraint on neurogenesis and the capacity to adjust rates of neuron addition in response to adult auditory experience is established early in development. PMID:18431053

  15. Development of electrical feedback controlled heat pipes and the advanced thermal control flight experiment

    NASA Technical Reports Server (NTRS)

    Bienert, W. B.

    1974-01-01

    The development and characteristics of electrical feedback controlled heat pipes (FCHP) are discussed. An analytical model was produced to describe the performance of the FCHP under steady state and transient conditions. An advanced thermal control flight experiment was designed to demonstrate the performance of the thermal control component in a space environment. The thermal control equipment was evaluated on the ATS-F satellite to provide performance data for the components and to act as a thermal control system which can be used to provide temperature stability of spacecraft components in future applications.

  16. Beam transport experiment with a new kicker control system on the HIRFL

    NASA Astrophysics Data System (ADS)

    Wang, Yan-Yu; Zhou, De-Tai; Luo, Jin-Fu; Zhang, Jian-Chuan; Zhou, Wen-Xiong; Ni, Fa-Fu; Yin, Jun; Yin, Jia; Yuan, You-Jin; Shang-Guan, Jing-Bin

    2016-04-01

    A kicker control system is used for beam extraction and injection between two cooling storage rings (CSRs) at the Heavy Ion Research Facility in Lanzhou (HIRFL). To meet the requirements of special physics experiments, the kicker controller has been upgraded, with a new controller designed based on ARM+DSP+FPGA technology and monolithic circuit architecture, which can achieve a precision time delay of 2.5 ns. In September 2014, the new kicker control system was installed in the kicker field, and the test experiment using the system was completed. In addition, a pre-trigger signal was provided by the controller, which was designed to synchronize the beam diagnostic system and physics experiments. Experimental results indicate that the phenomena of “missed kick” and “inefficient kick” were not observed, and the multichannel trigger signal delay could be adjusted individually for kick power supplies in digitization; thus, the beam transport efficiency was improved compared with that of the original system. The fast extraction and injection experiment was successfully completed based on the new kicker control systems for HIRFL. Supported by National Natural Science Foundation of China (U1232123)

  17. Middeck Active Control Experiment Reflight (MACE II): lessons learned and reflight status

    NASA Astrophysics Data System (ADS)

    Ninneman, Ronald R.; Denoyer, Keith K.

    2000-06-01

    The Air Force Research Laboratory (AFRL) is sponsoring the Middeck Active Control Experiment Reflight (MACE II) Program. MACE II is a manned space experiment that evaluates the capabilities of adaptive control of flexible structures in the zero-g environment of the space shuttle's Middeck. MACE II has grown out of lessons learned from the original MACE flight and from AFRL sponsored structural control experiments. Previous experiments required extensive testing and 'tuning' for their particular test environment to meet their performance expectations. Such a process is too inefficient to be seriously considered for operational systems, especially space-based systems where access is limited. MACE II takes the next logical step by evaluating the capability of adaptive structural control algorithms AFRL has assembled a team of five small businesses and universities to develop and evaluate several adaptive control methodologies. In addition, AFRL has recruited a second science team led by the Massachusetts Institute of Technology to evaluate control system for time-varying and geometrically nonlinear systems. This paper is an overview of the AFRL science team only.

  18. Role Based Access Control system in the ATLAS experiment

    NASA Astrophysics Data System (ADS)

    Valsan, M. L.; Dobson, M.; Lehmann Miotto, G.; Scannicchio, D. A.; Schlenker, S.; Filimonov, V.; Khomoutnikov, V.; Dumitru, I.; Zaytsev, A. S.; Korol, A. A.; Bogdantchikov, A.; Avolio, G.; Caramarcu, C.; Ballestrero, S.; Darlea, G. L.; Twomey, M.; Bujor, F.

    2011-12-01

    The complexity of the ATLAS experiment motivated the deployment of an integrated Access Control System in order to guarantee safe and optimal access for a large number of users to the various software and hardware resources. Such an integrated system was foreseen since the design of the infrastructure and is now central to the operations model. In order to cope with the ever growing needs of restricting access to all resources used within the experiment, the Roles Based Access Control (RBAC) previously developed has been extended and improved. The paper starts with a short presentation of the RBAC design, implementation and the changes made to the system to allow the management and usage of roles to control access to the vast and diverse set of resources. The RBAC implementation uses a directory service based on Lightweight Directory Access Protocol to store the users (~3000), roles (~320), groups (~80) and access policies. The information is kept in sync with various other databases and directory services: human resources, central CERN IT, CERN Active Directory and the Access Control Database used by DCS. The paper concludes with a detailed description of the integration across all areas of the system.

  19. Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Pilot-Scale Test Results

    SciTech Connect

    Gary M. Blythe

    2006-03-01

    This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, ''Field Testing of a Wet FGD Additive.'' The objective of the project is to demonstrate the use of a flue gas desulfurization (FGD) additive, Degussa Corporation's TMT-15, to prevent the reemissions of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate that the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine TMT salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project will conduct pilot and full-scale tests of the TMT-15 additive in wet FGD absorbers. The tests are intended to determine required additive dosage requirements to prevent Hg{sup 0} reemissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Power River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, TXU Generation Company LP, Southern Company, and Degussa Corporation. TXU Generation has provided the Texas lignite/PRB co-fired test site for pilot FGD tests, Monticello Steam Electric Station Unit 3. Southern Company is providing the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot and full-scale jet bubbling reactor (JBR) FGD systems to be tested. A third utility, to be named later, will provide the high-sulfur Eastern bituminous coal full-scale FGD test site. Degussa Corporation is providing the TMT-15 additive and technical support to the test program. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing in

  20. Tank Pressure Control Experiment - A low-g mixing investigation

    NASA Technical Reports Server (NTRS)

    Bentz, M. D.; Meserole, J. S.; Knoll, R. L.

    1990-01-01

    The Tank Pressure Control Experiment (TPCE) was conceived to meet the need for an aspect of cryogenic fluid management technology that is critical to several future national space missions: control of cryogenic storage tank pressures by active mixing. In-space testing is the only means of obtaining the fluid dynamic data necessary to develop and test predictive models of mixing. These models, when validated, will allow future cryogenic systems to be designed with more efficient and reliable pressure control systems. The objectives of the TPCE project are to characterize the fluid dynamics of jet-induced mixing in low gravity, evaluate the validity of empirical models and correlations, and provide data for use in developing and validating computational fluid dynamic models. This paper discusses prior studies of low-g mixing, the objectives and benefits of TPCE, the design and status of the payload, and preliminary results obtained from low-g aircraft testing.

  1. Control of the ST7 Disturbance Reduction System Flight Experiment

    NASA Technical Reports Server (NTRS)

    Maghami, P. G.; Hsu, O. C,; ODonnell, J. R., Jr.

    2007-01-01

    The Space Technology 7 (ST7) experiment will perform an on-orbit system-level validation of two specific Disturbance Reduction System technologies: colloidal micronewton thrusters and drag-free control. The ST7 Disturbance Reduction System (DRS) is designed to maintain the spacecraft s position with respect to a free-floating test mass while limiting the residual accelerations of that test mass over the frequency range of 1 to 30 mHz. This paper presents the overall design and analysis of the spacecraft drag-free and attitude controllers, with particular attention given to its primary mission mode. These controllers close the loop between the drag-free sensors and the colloidal micronewton thrusters.

  2. Control of Escherichia coli O157:H7 in contaminated alfalfa silage: Effects of silage additives.

    PubMed

    Ogunade, I M; Kim, D H; Jiang, Y; Weinberg, Z G; Jeong, K C; Adesogan, A T

    2016-06-01

    This study was conducted to examine if adding microbial inoculants or propionic acid to alfalfa silages contaminated with Escherichia coli O157:H7 would inhibit the growth of the pathogen during or after ensiling. Alfalfa forage was harvested at the early bloom stage, wilted to a dry matter concentration of 54%, chopped to 19-mm lengths, and ensiled after treatment with one of the following: (1) distilled water (control); (2) 1×10(5) cfu/g of E. coli O157:H7 (EC); (3) EC and 1×10(6) cfu/g of Lactobacillus plantarum (EC+LP); (4) EC and 1×10(6) cfu/g of Lactobacillus buchneri (EC+LB); and (5) EC and 2.2g/kg of propionic acid (EC+PA). Each treatment was ensiled in quadruplicate in laboratory silos for 0, 3, 7, 16, and 100d and analyzed for EC counts, pH, and organic acids. In addition, samples from d 100 were analyzed for chemical composition, ammonia-N, counts of yeasts and molds, and aerobic stability. Escherichia coli O157:H7 was detected in all silages until d 7, but by d 16 it was not detected in those treated with EC+LB and EC+LP, though it was still detected in EC and EC+PA silages. However, by d 100, the pathogen was not detected in any silage. The rate of pH decrease to 5.0 was fastest for the EC+LP silage (7d), followed by the EC+LB silage (16d). Nevertheless, all silages had attained a pH of or less than 5.0 by d 100. The rapid decrease in pH in EC+LP and EC+LB silages was observed due to higher lactate and acetate concentrations, respectively, relative to the other silages during the early fermentation phase (d 3-16). Propionic acid was only detected in the EC+PA silage. Yeast counts were lowest in EC+LB and EC+PA silages. Subsamples of all d-100 silages were reinoculated with 1×10(5) cfu/g of EC immediately after silo opening. When the pathogen was subsequently enumerated after 168h of aerobic exposure, it was not detected in silages treated with EC+PA, EC+LB, or EC+LP, which all had pH values less than 5.0. Whereas the EC silage had a pH value of 5

  3. Field Testing of a Wet FGD Additive for Enhanced Mercury Control

    SciTech Connect

    Gary Blythe; MariJon Owens

    2007-12-31

    This document is the final report for DOE-NETL Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project has been to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project was intended to demonstrate whether such additives can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project involved pilot- and full-scale tests of the additives in wet FGD absorbers. The tests were intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power provided the Texas lignite/PRB co-fired test site for pilot FGD tests and project cost sharing. Southern Company provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested, and project cost sharing. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation provided the TMT-15 additive, and the Nalco Company provided the Nalco 8034 additive. Both companies also supplied technical support to the test program as in-kind cost sharing. The project was conducted in six tasks. Of the six tasks, Task 1 involved project planning and Task 6 involved

  4. Control of hydrogen sulfide production in oil fields by managing microbial communities through nitrate or nitrite addition

    NASA Astrophysics Data System (ADS)

    Hubert, Casey R. J.

    Nitrate or nitrite injection into oil reservoirs during water flooding has the potential to control biological souring, the production of hydrogen sulfide (H2S) by sulfate-reducing bacteria (SRB). Souring control is essential because sulfide is toxic, sulfide precipitates can plug reservoir formations, souring lowers crude oil value, and SRB induce corrosion. Nitrate and nitrite can stimulate heterotrophic nitrate- or nitrite-reducing bacteria (hNRB) and nitrate- or nitrite-reducing, sulfide oxidizing bacteria (NRSOB). Nitrite also inhibits SRB activity by blocking the sulfate reduction pathway. Continuous up-flow packed-bed bioreactors were inoculated with produced water from the Coleville oil field to establish sulfide-producing biofilms similar to those found in sour reservoirs. Nitrate or nitrite addition to bioreactors indicated that the dose required for hNRB or NR-SOB to control souring depended on the concentration of oil organics. Either mechanism mediates the net removal of oil organics (lactate) with nitrate or nitrite, with lower doses of nitrate required due to its greater oxidative power. Microbial community analysis by reverse sample genome probing (RSGP) revealed that NR-SOB mediated sulfide removal at low nitrate or nitrite concentrations when lactate was still available to SRB and the redox potential was low. At high nitrate doses hNRB oxidized lactate directly, produced nitrite and maintained a high redox potential, thus excluding SRB activity. Facultatively chemolithotrophic Campylobacter sp. strains were isolated from the bioreactors and incorporated into RSGP analyses, revealing their dominance in both NR-SOB- and hNRB-containing communities. The metabolic flexibility of these strains may confer a competitive advantage over obligate chemolithotrophs like Thiomicrospira sp. strain CVO or hNRB that do not have NR-SOB activity like newly isolated Thauera sp. and Rhodobacter sp. strains. A single high dose of nitrite resulted in immediate

  5. Effects of biochar addition on greenhouse gas emissions and microbial responses in a short-term laboratory experiment.

    PubMed

    Yoo, Gayoung; Kang, Hojeong

    2012-01-01

    Biochar application to soil has drawn much attention as a strategy to sequester atmospheric carbon in soil ecosystems. The applicability of this strategy as a climate change mitigation option is limited by our understanding of the mechanisms responsible for the observed changes in greenhouse gas emissions from soils, microbial responses, and soil fertility changes. We conducted an 8-wk laboratory incubation using soils from PASTURE (silt loam) and RICE PADDY (silt loam) sites with and without two types of biochar (biochar from swine manure [CHAR-M] and from barley stover [CHAR-B]). Responses to addition of the different biochars varied with the soil source. Addition of CHAR-B did not change CO and CH evolution from the PASTURE or the RICE PADDY soils, but there was a decrease in NO emissions from the PASTURE soil. The effects of CHAR-M addition on greenhouse gas emissions were different for the soils. The most substantial change was an increase in NO emissions from the RICE PADDY soil. This result was attributed to a combination of abundant denitrifiers in this soil and increased net nitrogen mineralization. Soil phosphatase and N-acetylglucosaminidase activity in the CHAR-B-treated soils was enhanced compared with the controls for both soils. Fungal biomass was higher in the CHAR-B-treated RICE PADDY soil. From our results, we suggest CHAR-B to be an appropriate amendment for the PASTURE and RICE PADDY soils because it provides increased nitrogen availability and microbial activity with no net increase in greenhouse gas emissions. Application of CHAR-M to RICE PADDY soils could result in excess nitrogen availability, which may increase NO emissions and possible NO leaching problems. Thus, this study confirms that the ability of environmentally sound biochar additions to sequester carbon in soils depends on the characteristics of the receiving soil as well as the nature of the biochar. PMID:22751062

  6. Tank pressure control experiment on the space shuttle

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The tank pressure control experiment is a demonstration of NASA intent to develop new technology for low-gravity management of the cryogenic fluids that will be required for future space systems. The experiment will use freon as the test fluid to measure the effects of jet-induced fluid mixing on storage tank pressure and will produce data on low-gravity mixing processes critical to the design of on-orbit cryogenic storage and resupply systems. Basic data on fluid motion and thermodynamics in low gravity is limited, but such data is critical to the development of space transfer vehicles and spacecraft resupply facilities. An in-space experiment is needed to obtain reliable data on fluid mixing and pressure control because none of the available microgravity test facilities provide a low enough gravity level for a sufficient duration to duplicate in-space flow patterns and thermal processes. Normal gravity tests do not represent the fluid behavior properly; drop-tower tests are limited in length of time available; aircraft low-gravity tests cannot provide the steady near-zero gravity level and long duration needed to study the subtle processes expected in space.

  7. Control of asymmetry in the radical addition approach to chiral amine synthesis.

    PubMed

    Friestad, Gregory K

    2014-01-01

    The state-of-the-science in asymmetric free radical additions to imino compounds is presented, beginning with an overview of methods involving stereocontrol by various chiral auxiliary approaches. Chiral N-acylhydrazones are discussed with respect to their use as radical acceptors for Mn-mediated intermolecular additions, from design to scope surveys to applications to biologically active targets. A variety of aldehydes and ketones serve as viable precursors for the chiral hydrazones, and a variety of alkyl iodides may be employed as radical precursors, as discussed in a critical review of the functional group compatibility of the reaction. Applications to amino acid and alkaloid synthesis are presented to illustrate the synthetic potential of these versatile stereocontrolled carbon-carbon bond construction reactions. Asymmetric catalysis is discussed, from seminal work on the stereocontrol of radical addition to imino compounds by non-covalent interactions with stoichiometric amounts of catalysts, to more recent examples demonstrating catalyst turnover. PMID:24085561

  8. Control of Asymmetry in the Radical Addition Approach to Chiral Amine Synthesis

    PubMed Central

    Friestad, Gregory K.

    2014-01-01

    The state-of-the-science in asymmetric free radical additions to imino compounds is presented, beginning with an overview of methods involving stereocontrol by various chiral auxiliary approaches. Chiral N-acylhydrazones are discussed with respect to their use as radical acceptors for Mn-mediated intermolecular additions, from design to scope surveys to applications to biologically active targets. A variety of aldehydes and ketones serve as viable precursors for the chiral hydrazones, and a variety of alkyl iodides may be employed as radical precursors, as discussed in a critical review of the functional group compatibility of the reaction. Applications to amino acid and alkaloid synthesis are presented to illustrate the synthetic potential of these versatile stereocontrolled carbon–carbon bond construction reactions. Asymmetric catalysis is discussed, from seminal work on the stereocontrol of radical addition to imino compounds by non-covalent interactions with stoichiometric amounts of catalysts, to more recent examples demonstrating catalyst turnover. PMID:24085561

  9. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity

    NASA Technical Reports Server (NTRS)

    Hasan, Mohammad M.; Lin, Chin S.; Knoll, Richard H.; Bentz, Michael D.

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83% by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/sq m). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 C, respectively. The boiling process during the entire heating period, as well as the jet-induced mixing process for the first 2 min of the mixing period, was also recorded on video. The unique features of the experimental results are the sustainability of high liquid superheats for long periods and the occurrence of explosive boiling at low heat fluxes (0.86 to 1.1 kW/sq m). For a heat flux of 0.97 kW/sq m, a wall superheat of 17.9 C was attained in 10 min of heating. This superheat was followed by an explosive boiling accompanied by a pressure spike of about 38% of the tank pressure at the inception of boiling. However, at this heat flux the vapor blanketing the heating surface could not be sustained. Steady nucleate boiling continued after the explosive boiling. The jet-induced fluid mixing results were obtained for jet Reynolds numbers of 1900 to 8000 and Weber numbers of 0.2 to 6.5. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments

  10. C-SIDE: The control-structure interaction demonstration experiment

    NASA Technical Reports Server (NTRS)

    Mohl, James B.; Davis, Hugh W.

    1993-01-01

    The Control-Structure Interaction Demonstration Experiment (C-SIDE) is sponsored by the Electro-Optics and Cryogenics Division of Ball Aerospace Systems Group. Our objective is to demonstrate methods of solution to structure control problems utilizing currently available hardware in a system that is an extension of our corporate experience. The larger space structures with which Ball has been associated are the SEASAT radar antenna, Shuttle Imaging Radar (SIR) -A, -B and -C antennas and the Radarsat spacecraft. The motivation for the C-SIDE configuration is to show that integration of active figure control in the radar's system-level design can relieve antenna mechanical design constraints. This presentation is primarily an introduction to the C-SIDE testbed. Its physical and functional layouts, and major components are described. The sensor is of special interest as it enables direct surface figure measurements from a remote location. The Remote Attitude Measurement System (RAMS) makes high-rate, unobtrusive measurements of many locations, several of which may be collocated easily with actuators. The control processor is a 386/25 executing a reduced order model-based algorithm with provision for residual mode filters to compensate for structure interaction. The actuators for the ground demonstration are non-contacting, linear force devices. Results presented illustrate some basic characteristics of control-structure interaction with this hardware. The testbed will be used for evaluation of current technologies and for research in several areas. A brief indication of the evolution of the C-SIDE is given at the conclusion.

  11. Theileriosis control modelling (experiences from Southern Province, Zambia).

    PubMed

    Penne, K; D'Haese, L

    1999-09-01

    Effects of different tick-borne disease control strategies on cattle productivity are simulated based on a 30-year herd projection, calculated by a modified Markov Chain model. Input data can be grouped in technical, economic and epidemiological parameters. The output is a set of economic parameters such as benefit/cost ratio (BCR), net present value (NPV) of the profit, internal rate of return (IRR), total economic cost (TEC) as well as graphs showing animal production over time. Shadow prices are obtained for input and output in kind. Throughout the calculations a distinction is made between transactions in cash and transactions in kind. A case study was run for Southern Province, Zambia, to illustrate the model. Either vector control or treatment, or a combination of these, controls theileriosis at farm level after natural infection. Preventive immunization against the parasite is also possible. Although the calculations are based on a mixture of data obtained from literature, field experience, expert opinion and assumptions, the importance of theileriosis control is clearly indicated. Immunization gives better economic results than chemotherapy. Vector control can only be used as a last resort. PMID:10540313

  12. Integrated Power/Attitude Control System (IPACS) technology experiment

    NASA Technical Reports Server (NTRS)

    Keckler, C. R.

    1984-01-01

    An experiment is proposed that will perform the tasks associated with the control and energy storage/power generation functions attendant to space operations. It was shown in past studies that the integration of these functions into one system can result in significant weight, volume, and cost savings. The Integrated Power/Attitude Control System (IPACS) concept is discussed. During orbit day, power is derived from the solar cell arrays and, after appropriate conditioning, is used to operate the spacecraft subsystems, including the control system. In conventional approaches, a part of the collected solar energy is stored in a bank of batteries to permit operation of the vehicle's systems during orbit night. In the IPACS concept, the solar energy is stored in the spinning flywheels of the control system in the form of kinetic energy. During orbit night, the wheels are despun and, through the use of a wheel-shaft mounted generator, power is generated for the onboard subsystems. Operating these flywheels over a 50-percent speed variation permits the extraction of 75 percent of the stored energy while at the same time preserving 50 percent of the momentum capacity for control of the vehicle. Batteries can therefore be eliminated and significant weight and volume savings realized.

  13. LONG-TERM DEMONSTRATION OF SORBENT ENHANCEMENT ADDITIVE TECHNOLOGY FOR MERCURY CONTROL

    SciTech Connect

    Jason D. Laumb; Dennis L. Laudal; Grant E. Dunham; John P. Kay; Christopher L. Martin; Jeffrey S. Thompson; Nicholas B. Lentz; Alexander Azenkeng; Kevin C. Galbreath; Lucinda L. Hamre

    2011-05-27

    Long-term demonstration tests of advanced sorbent enhancement additive (SEA) technologies have been completed at five coal-fired power plants. The targeted removal rate was 90% from baseline conditions at all five stations. The plants included Hawthorn Unit 5, Mill Creek Unit 4, San Miguel Unit 1, Centralia Unit 2, and Hoot Lake Unit 2. The materials tested included powdered activated carbon, treated carbon, scrubber additives, and SEAs. In only one case (San Miguel) was >90% removal not attainable. The reemission of mercury from the scrubber at this facility prevented >90% capture.

  14. The MODE family of on-orbit experiments: The Middeck Active Control Experiment (MACE)

    NASA Technical Reports Server (NTRS)

    Crawley, Edward F.; Miller, David W.; Deluis, Javier; Waldman, Mel; Bicos, Andy

    1990-01-01

    A flight experiment entitled the Middeck Active Control Experiment (MACE), proposed by the Space Engineering Research Center (SERC) at the Massachusetts Institute of Technology, is described. This is the second in a family of flight experiments being developed at MIT. The first is the Middeck 0-Gravity Dynamics Experiment (MODE) which investigates the nonlinear behavior of contained fluids and truss structures in zero gravity. The objective of the MACE program is to investigate and validate the modeling of the dynamics of an actively controlled flexible, articulating, multibody platform free floating in zero gravity. A rationale and experimental approach for the program are presented. The rationale shows that on-orbit testing, coupled with ground testing and a strong analytical program, is necessary in order to fully understand both how flexibility of the platform affects the pointing problem, as well as how gravity perturbs this structural flexibility causing deviations between 1- and 0-gravity behavior. The experimental approach captures the essential physics of multibody platforms, by identifying the appropriate attributes, tests, and performance metrics of the test article and defines the tests required to successfully validate the analytical framework.

  15. The MODE family of on-orbit experiments: The Middeck Active Control Experiment (MACE)

    NASA Astrophysics Data System (ADS)

    Crawley, Edward F.; Miller, David W.; Deluis, Javier; Waldman, Mel; Bicos, Andy

    1990-12-01

    A flight experiment entitled the Middeck Active Control Experiment (MACE), proposed by the Space Engineering Research Center (SERC) at the Massachusetts Institute of Technology, is described. This is the second in a family of flight experiments being developed at MIT. The first is the Middeck 0-Gravity Dynamics Experiment (MODE) which investigates the nonlinear behavior of contained fluids and truss structures in zero gravity. The objective of the MACE program is to investigate and validate the modeling of the dynamics of an actively controlled flexible, articulating, multibody platform free floating in zero gravity. A rationale and experimental approach for the program are presented. The rationale shows that on-orbit testing, coupled with ground testing and a strong analytical program, is necessary in order to fully understand both how flexibility of the platform affects the pointing problem, as well as how gravity perturbs this structural flexibility causing deviations between 1- and 0-gravity behavior. The experimental approach captures the essential physics of multibody platforms, by identifying the appropriate attributes, tests, and performance metrics of the test article and defines the tests required to successfully validate the analytical framework.

  16. MISSE Thermal Control Materials with Comparison to Previous Flight Experiments

    NASA Technical Reports Server (NTRS)

    Finckenor, Miria; Pippin, H. Gary; Frey, George

    2008-01-01

    Many different passive thermal control materials were flown as part of the Materials on International Space Station Experiment (MISSE), including inorganic coatings, anodized aluminum, and multi-layer insulation materials. These and other material samples were exposed to the low Earth orbital environment of atomic oxygen, ultraviolet radiation, thermal cycling, and hard vacuum, though atomic oxygen exposure was limited for some samples. Materials flown on MISSE-1 and MISSE-2 were exposed to the space environment for nearly four years. Materials flown on MISSE-3, MISSE-4, and MISSE-5 were exposed to the space environment for one year. Solar absorptance, infrared emittance, and mass measurements indicate the durability of these materials to withstand the space environment. Effects of short duration versus long duration exposure on ISS are explored, as well as comparable data from previous flight experiments, such as the Passive Optical Sample Assembly (POSA), Optical Properties Monitor (OPM), and Long Duration Exposure Facility (LDEF).

  17. How Life Experience Shapes Cognitive Control Strategies: The Case of Air Traffic Control Training.

    PubMed

    Arbula, Sandra; Capizzi, Mariagrazia; Lombardo, Nicoletta; Vallesi, Antonino

    2016-01-01

    Although human flexible behavior relies on cognitive control, it would be implausible to assume that there is only one, general mode of cognitive control strategy adopted by all individuals. For instance, different reliance on proactive versus reactive control strategies could explain inter-individual variability. In particular, specific life experiences, like a highly demanding training for future Air Traffic Controllers (ATCs), could modulate cognitive control functions. A group of ATC trainees and a matched group of university students were tested longitudinally on task-switching and Stroop paradigms that allowed us to measure indices of cognitive control. The results showed that the ATCs, with respect to the control group, had substantially smaller mixing costs during long cue-target intervals (CTI) and a reduced Stroop interference effect. However, this advantage was present also prior to the training phase. Being more capable in managing multiple task sets and less distracted by interfering events suggests a more efficient selection and maintenance of task relevant information as an inherent characteristic of the ATC group, associated with proactive control. Critically, the training that the ATCs underwent improved their accuracy in general and reduced response time switching costs during short CTIs only. These results indicate a training-induced change in reactive control, which is described as a transient process in charge of stimulus-driven task detection and resolution. This experience-based enhancement of reactive control strategy denotes how cognitive control and executive functions in general can be shaped by real-life training and underlines the importance of experience in explaining inter-individual variability in cognitive functioning. PMID:27311017

  18. How Life Experience Shapes Cognitive Control Strategies: The Case of Air Traffic Control Training

    PubMed Central

    Arbula, Sandra; Capizzi, Mariagrazia; Lombardo, Nicoletta; Vallesi, Antonino

    2016-01-01

    Although human flexible behavior relies on cognitive control, it would be implausible to assume that there is only one, general mode of cognitive control strategy adopted by all individuals. For instance, different reliance on proactive versus reactive control strategies could explain inter-individual variability. In particular, specific life experiences, like a highly demanding training for future Air Traffic Controllers (ATCs), could modulate cognitive control functions. A group of ATC trainees and a matched group of university students were tested longitudinally on task-switching and Stroop paradigms that allowed us to measure indices of cognitive control. The results showed that the ATCs, with respect to the control group, had substantially smaller mixing costs during long cue-target intervals (CTI) and a reduced Stroop interference effect. However, this advantage was present also prior to the training phase. Being more capable in managing multiple task sets and less distracted by interfering events suggests a more efficient selection and maintenance of task relevant information as an inherent characteristic of the ATC group, associated with proactive control. Critically, the training that the ATCs underwent improved their accuracy in general and reduced response time switching costs during short CTIs only. These results indicate a training-induced change in reactive control, which is described as a transient process in charge of stimulus-driven task detection and resolution. This experience-based enhancement of reactive control strategy denotes how cognitive control and executive functions in general can be shaped by real-life training and underlines the importance of experience in explaining inter-individual variability in cognitive functioning. PMID:27311017

  19. Low-g fluid mixing - Further results from the Tank Pressure Control Experiment

    NASA Technical Reports Server (NTRS)

    Bentz, M. D.; Knoll, R. H.; Hasan, M. M.; Lin, C. S.

    1993-01-01

    The Tank Pressure Control Experiment (TPCE) made its first space flight on STS-43 in 1991. Its objective was to test the effectiveness of low-energy axial jet mixing at controlling pressures in low gravity. The experiment used refrigerant 113 at near-saturation conditions, at an 83 percent fill level, to simulate the fluid dynamics and thermodynamics of cryogenic fluids in future space applications. Results from this flight were reported previously. TPCE was again flown in space on STS-52 in 1992, this time primarily to study boiling and related thermal phenomena which will be reported elsewhere. However additional mixing and pressure control data were obtained from the reflight that supplement the data from the first flight.

  20. Decompression experiments identify kinetic controls on explosive silicic eruptions

    USGS Publications Warehouse

    Mangan, M.T.; Sisson, T.W.; Hankins, W.B.

    2004-01-01

    Eruption intensity is largely controlled by decompression-induced release of water-rich gas dissolved in magma. It is not simply the amount of gas that dictates how forcefully magma is propelled upwards during an eruption, but also the rate of degassing, which is partly a function of the supersaturation pressure (??Pcritical) triggering gas bubble nucleation. High temperature and pressure decompression experiments using rhyolite and dacite melt reveal compositionally-dependent differences in the ??Pcritical of degassing that may explain why rhyolites have fueled some of the most explosive eruptions on record.

  1. DASHBOARDS & CONTROL CHARTS EXPERIENCES IN IMPROVING SAFETY AT HANFORD WASHINGTON

    SciTech Connect

    PREVETTE, S.S.

    2006-02-27

    The aim of this paper is to demonstrate the integration of safety methodology, quality tools, leadership, and teamwork at Hanford and their significant positive impact on safe performance of work. Dashboards, Leading Indicators, Control charts, Pareto Charts, Dr. W. Edward Deming's Red Bead Experiment, and Dr. Deming's System of Profound Knowledge have been the principal tools and theory of an integrated management system. Coupled with involved leadership and teamwork, they have led to significant improvements in worker safety and protection, and environmental restoration at one of the nation's largest nuclear cleanup sites.

  2. Experiments in teleoperator and autonomous control of space robotic vehicles

    NASA Technical Reports Server (NTRS)

    Alexander, Harold L.

    1991-01-01

    A program of research embracing teleoperator and automatic navigational control of freely flying satellite robots is presented. Current research goals include: (1) developing visual operator interfaces for improved vehicle teleoperation; (2) determining the effects of different visual interface system designs on operator performance; and (3) achieving autonomous vision-based vehicle navigation and control. This research program combines virtual-environment teleoperation studies and neutral-buoyancy experiments using a space-robot simulator vehicle currently under development. Visual-interface design options under investigation include monoscopic versus stereoscopic displays and cameras, helmet-mounted versus panel-mounted display monitors, head-tracking versus fixed or manually steerable remote cameras, and the provision of vehicle-fixed visual cues, or markers, in the remote scene for improved sensing of vehicle position, orientation, and motion.

  3. Thermal control surfaces experiment (SOO69) flight systems performance

    NASA Technical Reports Server (NTRS)

    Wilkes, Donald R.; Hummer, Leigh L.

    1991-01-01

    The thermal control surfaces experiment (TCSE) was the most complex hardware system aboard the Long Duration Exposure Facility (LDEF). The TCSE system consists of a scanning spectroreflectometer that measured test samples mounted on a rotatable carousel assembly. A microprocessor based data system controlled all aspects of TCSE system operation. Power was provided by four primary batteries. Flight measurement and housekeeping data were stored on a tape recorder for postflight analysis. The TCSE is a microcosm of complex electro-optical payloads being developed by NASA, DoD, and the aerospace community. The TCSE provides valuable data on the performance of these systems in space. The TCSE flight system and its excellent performance on the LDEF mission are described. A few operational anomalies were encountered and are discussed. Initial post-flight tests show that the TCSE system remains functional although some degradation in the optical measurements were observed. The results of these tests are also presented.

  4. Operator experiences on working in screen-based control rooms

    SciTech Connect

    Salo, L.; Laarni, J.; Savioja, P.

    2006-07-01

    This paper introduces the results of two interview studies carried out in Finland in four conventional power plants and one nuclear power plant. The aim of the studies was to gather data on user experiences on the effects of control room modernization and digital control room technology on operator work Since the number of completed digitalization projects in nuclear power plants is small supplementary information was gathered by interviewing operators in conventional power plants. Our results suggest that even though the modernization processes have been success stories, they have created new challenges for operator personnel. Examples of these challenges are increased requirements for competence and collaboration, problems in trust calibration and development of awareness of the process state. Some major differences in the digitalization of human-system interfaces between conventional and nuclear power plants were discussed. (authors)

  5. Metal-ceramic microstructures in the Fe-Mn-O system -- Morphology control by impurity addition

    SciTech Connect

    Subramanian, R.; Uestuendag, E.; Sass, S.L.; Dieckmann, R.

    1995-10-01

    The influence of the addition of impurities and changes in the oxygen partial pressure on the formation of metal-ceramic microstructures by partial reduction of ternary or higher ceramic oxides was experimentally investigated in the model system Fe-Mn-O at constant temperature and total pressure. Electron microscopy studies were performed for microstructural characterization, phase identification and chemical analysis. It was observed that the addition of dopants such as BaO, CaO, MgO, SrO, Al{sub 2}O{sub 3}, Cr{sub 2}O{sub 3} or ZrO{sub 2} to the initial, polycrystalline oxide solid solution (Fe{sub 1{minus}x}Mn{sub x}){sub 1{minus}{Delta}}O strongly influences the location and rate of metal precipitation during reduction. Experimental observations are discussed based on solubility limits and the segregation of dopants.

  6. Controlled laboratory challenge demonstrates substantial additive genetic variation in resistance to Streptococcus iniae in Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is an etiologic agent of streptococcal disease in tilapia and is one of several Streptococcus spp. that negatively impact worldwide tilapia production. Methods for the prevention and control of S. iniae include vaccines, management strategies, and antibiotics. An alternative and ...

  7. PCB bioavailability control in Lumbriculus variegatus through different modes of activated carbon addition to sediments

    SciTech Connect

    Xueli Sun; Upal Ghosh

    2007-07-01

    PCB bioavailability to a freshwater oligochaete (Lumbriculus variegatus) was studied using sediments from a PCB-impacted river that was treated with different modes of granular activated carbon (GAC) addition. The GAC used was bituminous coal-based type TOP. For sediment treated with 2.6% GAC and mixed for 2 min prior to L. variegatus addition, the reduction in total PCB biouptake was 70% for 75-300 {mu}m size carbon, and 92% for the 45-180 {mu}m size carbon. For the case where the GAC was placed as a thin layer on top of the sediments without mixing, the reduction in total PCB uptake was 70%. PCB biouptake kinetics study using treated and untreated sediment showed that the maximum PCB uptake in tissue was achieved at 28 days and decreased after that time. Although the absolute uptake of PCB changed over time, the percent reduction in total PCB uptake upon GAC amendment remained constant after the first few days. Our results indicated that PCB bioavailability was reduced upon the addition and little or no mixing of GAC into sediments. PCB aqueous equilibrium concentration and desorption rates were greatly reduced after GAC amendment, indicating reductions in the two primary mechanisms of PCB bioavailability in sediments: chemical activity and chemical accessibility. 29 refs., 5 figs., 1 tab.

  8. Using epidemiology to regulate food additives: saccharin case-control studies.

    PubMed

    Cordle, F; Miller, S A

    1984-01-01

    The increasing use of nonnutritive sweeteners and the widely publicized 1969 ban on cyclamate led to additional investigations in rodents of the carcinogenic potential of saccharin. Preliminary results of a long-term feeding study indicated formation of bladder tumors in rodents, and collective experimental evidence has demonstrated that high doses of the synthetic sweetener saccharin can cause bladder cancer in rodents. Based on the results of that and other rodent studies indicating an increased risk of bladder cancer associated with saccharin, the Commissioner of the Food and Drug Administration announced the agency's intention to propose a ban on saccharin. This intention was made known in April 1977 under the Delaney Clause of the Food, Drug, and Cosmetic Act. The clause essentially states that no additive shall be deemed safe if it is found to induce cancer in man or animals, or if it is found, after tests appropriate for the evaluation of the safety of food additives, to induce cancer in man or animals. Also in 1977, a group of epidemiologists began to assess the available epidemiologic information to determine the potential human risk. This report describes the assessment of several human epidemiologic studies available then and the results of more recent epidemiologic studies. PMID:6431484

  9. Additive manufacturing of scaffolds with dexamethasone controlled release for enhanced bone regeneration.

    PubMed

    Costa, Pedro F; Puga, Ana M; Díaz-Gomez, Luis; Concheiro, Angel; Busch, Dirk H; Alvarez-Lorenzo, Carmen

    2015-12-30

    The adoption of additive manufacturing in tissue engineering and regenerative medicine (TERM) strategies greatly relies on the development of novel 3D printable materials with advanced properties. In this work we have developed a material for bone TERM applications with tunable bioerosion rate and dexamethasone release profile which can be further employed in fused deposition modelling (the most common and accessible 3D printing technology in the market). The developed material consisted of a blend of poly-ϵ-caprolactone (PCL) and poloxamine (Tetronic®) and was processed into a ready-to-use filament form by means of a simplified melt-based methodology, therefore eliminating the utilization of solvents. 3D scaffolds composed of various blend formulations were additively manufactured and analyzed revealing blend ratio-specific degradation rates and dexamethasone release profiles. Furthermore, in vitro culture studies revealed a similar blend ratio-specific trend concerning the osteoinductive activity of the fabricated scaffolds when these were seeded and cultured with human mesenchymal stem cells. The developed material enables to specifically address different regenerative requirements found in various tissue defects. The versatility of such strategy is further increased by the ability of additive manufacturing to accurately fabricate implants matching any given defect geometry. PMID:26520408

  10. Experience in control of avian influenza in the Americas.

    PubMed

    Villarreal, C

    2007-01-01

    The outbreaks of highly pathogenic avian influenza (HPAI) in Canada in 1966, the USA in 1984 and Mexico in 1994 led to a clear increase in biosecurity measures and improved intensive poultry production systems. In the past 12 years (1994-2006), there have been four outbreaks of HPAI on the American continent: in Mexico in 1994 (H5N2), in Chile in 2002 (H7N3), in the USA in 2004 (H5N2) and in Canada in 2004 (H7N3). In all cases, the control and eradication measures were based on prompt detection, depopulation of infected farms and epidemiological contacts, increased biosecurity measures and control of the movement of live poultry and their products, by-products and infected material. In Mexico, in addition to the aforementioned measures, the use of massive vaccination allowed eradication of HPAI in a relatively short time in two affected areas of high-density commercial poultry. PMID:18416017

  11. Propulsion control experience used in the Highly Integrated Digital Electronic Control (HIDEC) program

    NASA Technical Reports Server (NTRS)

    Myers, L. P.; Burcham, F. W., Jr.

    1984-01-01

    The highly integrated digital electronic control (HIDEC) program will integrate the propulsion and flight control systems on an F-15 airplane at NASA Ames Research Center's Dryden Flight Research Facility. Ames-Dryden has conducted several propulsion control programs that have contributed to the HIDEC program. The digital electronic engine control (DEEC) flight evaluation investigated the performance and operability of the F100 engine equipped with a full-authority digital electronic control system. Investigations of nozzle instability, fault detection and accommodation, and augmentor transient capability provided important information for the HIDEC program. The F100 engine model derivative (EMD) was also flown in the F-15 airplane, and airplane performance was significantly improved. A throttle response problem was found and solved with a software fix to the control logic. For the HIDEC program, the F100 EMD engines equipped with DEEC controls will be integrated with the digital flight control system. The control modes to be implemented are an integrated flightpath management mode and an integrated adaptive engine control system mode. The engine control experience that will be used in the HIDEC program is discussed.

  12. Determination of Unknown Concentrations of Sodium Acetate Using the Method of Standard Addition and Proton NMR: An Experiment for the Undergraduate Analytical Chemistry Laboratory

    ERIC Educational Resources Information Center

    Rajabzadeh, Massy

    2012-01-01

    In this experiment, students learn how to find the unknown concentration of sodium acetate using both the graphical treatment of standard addition and the standard addition equation. In the graphical treatment of standard addition, the peak area of the methyl peak in each of the sodium acetate standard solutions is found by integration using…

  13. EXCON: a graphics-based experiment-control manager

    NASA Astrophysics Data System (ADS)

    Khan, Mumit; Anderson, Paul D.; Cerrina, Franco

    1991-08-01

    EXCON is a software package developed to control and define the modeling of experiments. In this case, EXCON is used to integrate various individual modeling systems, in a user- definable manner, to simulate the semiconductor manufacturing process. These numerous systems model specific aspects of the integrated circuit fabrication process. Each can be a large complex software program requiring many system resources to reliably emulate the physical processes, in many cases at the atomic level, in an analytical manner. There are many different program data formats and user interfaces within the modeling systems used. EXCON addresses the automatic insertion of configuration and process data, the conversion of data formats between modeling systems, and the sequence of model execution. EXCON also has a mechanism to re-run the sequence of models with variations in one or several configuration or data parameters, thereby creating an environment to do controlled experiments. EXCON assists in the visualization of the data in the experimental data sequence. EXCON allows for coarse-grained parallelism by connecting processes with an interprocess and inter-machine communication mechanism, thereby allowing for concurrent execution of processes on multiple machines. System performance enhancement is done with a incremental directed graph analysis technique. EXCON will, when appropriate, transparently convert file formats between modeling systems.

  14. Experience in control of avian influenza in Asia.

    PubMed

    Sims, L D

    2007-01-01

    Highly pathogenic H5N1 avian influenza viruses have been circulating in Asia for over ten years, providing considerable experience on which to base appropriate long-term strategies for their control. Experience in Hong Kong SAR demonstrates that existing production and marketing practices should be changed and a range of parallel measures used. It also shows the extent of surveillance required to ensure continuing freedom from infection. Certain high-risk practices should be changed or otherwise overcome in order to control and prevent disease, including intensive rearing of large numbers of poultry in premises without biosecurity commensurate with the level of risk for exposure; complex market chains involving many smallholders selling poultry through large numbers of transporters and middlemen in poorly regulated live poultry markets; and rearing of large numbers of ducks outdoors. These high-risk practices are compounded by weak veterinary services and poor reporting systems. In many parts of Asia, these methods of rearing and marketing are an integral way of life, support the poorest members of the community or cannot be changed quickly without severe socioeconomic consequences. The gains made so far will be ephemeral unless there is a shift from an emergency focus to one of consolidation in which these high-risk practices are identified and sustainable measures implemented to minimize the risks they pose, taking account of the socioeconomic effects of interventions. Vaccination will play a key role, as it currently does in China and Viet Nam. PMID:18411934

  15. Statistical physics of human beings in games: Controlled experiments

    NASA Astrophysics Data System (ADS)

    Liang, Yuan; Huang, Ji-Ping

    2014-07-01

    It is important to know whether the laws or phenomena in statistical physics for natural systems with non-adaptive agents still hold for social human systems with adaptive agents, because this implies whether it is possible to study or understand social human systems by using statistical physics originating from natural systems. For this purpose, we review the role of human adaptability in four kinds of specific human behaviors, namely, normal behavior, herd behavior, contrarian behavior, and hedge behavior. The approach is based on controlled experiments in the framework of market-directed resource-allocation games. The role of the controlled experiments could be at least two-fold: adopting the real human decision-making process so that the system under consideration could reflect the performance of genuine human beings; making it possible to obtain macroscopic physical properties of a human system by tuning a particular factor of the system, thus directly revealing cause and effect. As a result, both computer simulations and theoretical analyses help to show a few counterparts of some laws or phenomena in statistical physics for social human systems: two-phase phenomena or phase transitions, entropy-related phenomena, and a non-equilibrium steady state. This review highlights the role of human adaptability in these counterparts, and makes it possible to study or understand some particular social human systems by means of statistical physics coming from natural systems.

  16. ALMA test interferometer control system: past experiences and future developments

    NASA Astrophysics Data System (ADS)

    Marson, Ralph G.; Pokorny, Martin; Kern, Jeff; Stauffer, Fritz; Perrigouard, Alain; Gustafsson, Birger; Ramey, Ken

    2004-09-01

    The Atacama Large Millimeter Array (ALMA) will, when it is completed in 2012, be the world's largest millimeter & sub-millimeter radio telescope. It will consist of 64 antennas, each one 12 meters in diameter, connected as an interferometer. The ALMA Test Interferometer Control System (TICS) was developed as a prototype for the ALMA control system. Its initial task was to provide sufficient functionality for the evaluation of the prototype antennas. The main antenna evaluation tasks include surface measurements via holography and pointing accuracy, measured at both optical and millimeter wavelengths. In this paper we will present the design of TICS, which is a distributed computing environment. In the test facility there are four computers: three real-time computers running VxWorks (one on each antenna and a central one) and a master computer running Linux. These computers communicate via Ethernet, and each of the real-time computers is connected to the hardware devices via an extension of the CAN bus. We will also discuss our experience with this system and outline changes we are making in light of our experiences.

  17. Carbon monoxide exposures from propane-powered floor burnishers following addition of emissions controls

    SciTech Connect

    Demer, F.R.

    1998-11-01

    Previous published work by this author suggests that propane-powered floor burnisher use represents a potentially serious health hazard from carbon monoxide exposures, particularly for susceptible individuals. This earlier study was repeated using burnishers retrofitted with emission controls consisting of self-aspirating catalytic mufflers and computerized air/fuel monitors and alarms. Real-time carbon monoxide detectors with data-logging capabilities were placed on the burnishers in the breathing zones of operators during burnisher use. Carbon monoxide levels were recorded every 30 seconds. Ventilation and physical characteristics of the spaces of burnisher use were characterized, as were burnisher maintenance practices. Thirteen burnishing events were monitored under conditions comparable to previously published monitoring. All carbon monoxide exposures were well below even the most conservative recommended limits from the American Conference of Governmental Industrial Hygienists. Potential failures of the emission controls were also identified and included air filter blockage, spark plug malfunction, and faulty alarm function design.

  18. Experiences of baby-led weaning: trust, control and renegotiation.

    PubMed

    Arden, Madelynne A; Abbott, Rachel L

    2015-10-01

    Baby-led weaning (BLW) is an approach to introducing solid foods that relies on the presence of self-feeding skills and is increasing in popularity in the UK and New Zealand. This study aimed to investigate the reported experiences and feelings of mothers using a BLW approach in order to better understand the experiences of the mother and infant, the benefits and challenges of the approach, and the beliefs that underpin these experiences. Fifteen UK mothers were interviewed over the course of a series of five emails using a semi-structured approach. The email transcripts were anonymised and analysed using thematic analysis. There were four main themes identified from the analysis: (1) trusting the child; (2) parental control and responsibility; (3) precious milk; and (4) renegotiating BLW. The themes identified reflect a range of ideals and pressures that this group of mothers tried to negotiate in order to provide their infants with a positive and healthy introduction to solid foods. One of the key issues of potential concern is the timing at which some of the children ingested complementary foods. Although complementary foods were made available to the infants at 6 months of age, in many cases they were not ingested until much later. These findings have potentially important implications for mother's decision-making, health professional policy and practice, and future research. PMID:24521206

  19. Doing C2 (Command Control) experiments using war games

    NASA Astrophysics Data System (ADS)

    Lawson, J. S., Jr.

    1983-12-01

    In the last few years considerable progress has been made in the development of an analytic theory of military Command Control (C2), both as a process and as a large-scale system. There are now models of C2 organizations which permit the examination of the effects of various changes in a C2 system and which can predict some of the behavior of such a system in a gross sense. And, due to the increased attention being given the field, with the attendant increase in papers, workshops, etcetera, there is slowly developing a common vocabulary for use in the emerging C2 Theory. What is still lacking, however, is a body of experimental data which can be used as a touchstone to guide further theoretical developments, and against which theoretical predictions can be tested. This paper reports the results of a very rudimentary experiment which was conducted at the Naval Postgraduate School at Monterey, California, during the 1983 Winter Quarter to test two specific hypotheses. As is often the case, it was found necessary to modify or restate the hypotheses during the conduct of the experiment in order to accommodate certain real world constraints. The results, however, are both interesting in their own right and reassuring for the prospect of being able to do further experiments in the C2 arena.

  20. The LHC Compact Muon Solenoid experiment Detector Control System

    NASA Astrophysics Data System (ADS)

    Bauer, G.; Beccati, B.; Behrens, U.; Biery, K.; Bouffet, O.; Branson, J.; Bukowiec, S.; Cano, E.; Cheung, H.; Ciganek, M.; Cittolin, S.; Coarasa, J. A.; Deldicque, C.; Dupont, A.; Erhan, S.; Gigi, D.; Glege, F.; Gomez-Reino, R.; Hatton, D.; Holzner, A.; Hwong, Y. L.; Masetti, L.; Meijers, F.; Meschi, E.; Mommsen, R. K.; Moser, R.; O'Dell, V.; Orsini, L.; Paus, C.; Petrucci, A.; Pieri, M.; Racz, A.; Raginel, O.; Sakulin, H.; Sani, M.; Schieferdecker, P.; Schwick, C.; Shpakov, D.; Simon, M.; Sumorok, K.

    2011-12-01

    The Compact Muon Solenoid (CMS) experiment at CERN is a multi-purpose experiment designed to exploit the physics of proton-proton collisions at the Large Hadron Collider collision energy (14TeV at centre of mass) over the full range of expected luminosities (up to 1034cm-2s-1). The CMS detector control system (DCS) ensures a safe, correct and efficient operation of the detector so that high quality physics data can be recorded. The system is also required to operate the detector with a small crew of experts who can take care of the maintenance of its software and hardware infrastructure. The subsystems size sum up to more than a million parameters that need to be supervised by the DCS. A cluster of roughly 100 servers is used to provide the required processing resources. A scalable approach has been chosen factorizing the DCS system as much as possible. CMS DCS has made clear a division between its computing resources and functionality by creating a computing framework allowing plugging in of functional components. DCS components are developed by the subsystems expert groups while the computing infrastructure is developed centrally. To ensure the correct operation of the detector, DCS organizes the communication between the accelerator and the experiment systems making sure that the detector is in a safe state during hazardous situations and is fully operational when stable conditions are present. This paper describes the current status of the CMS DCS focusing on operational aspects and the role of DCS in this communication.

  1. Control of Cr6+ emissions from gas metal arc welding using a silica precursor as a shielding gas additive.

    PubMed

    Topham, Nathan; Wang, Jun; Kalivoda, Mark; Huang, Joyce; Yu, Kuei-Min; Hsu, Yu-Mei; Wu, Chang-Yu; Oh, Sewon; Cho, Kuk; Paulson, Kathleen

    2012-03-01

    Hexavalent chromium (Cr(6+)) emitted from welding poses serious health risks to workers exposed to welding fumes. In this study, tetramethylsilane (TMS) was added to shielding gas to control hazardous air pollutants produced during stainless steel welding. The silica precursor acted as an oxidation inhibitor when it decomposed in the high-temperature welding arc, limiting Cr(6+) formation. Additionally, a film of amorphous SiO(2) was deposited on fume particles to insulate them from oxidation. Experiments were conducted following the American Welding Society (AWS) method for fume generation and sampling in an AWS fume hood. The results showed that total shielding gas flow rate impacted the effectiveness of the TMS process. Increasing shielding gas flow rate led to increased reductions in Cr(6+) concentration when TMS was used. When 4.2% of a 30-lpm shielding gas flow was used as TMS carrier gas, Cr(6+) concentration in gas metal arc welding (GMAW) fumes was reduced to below the 2006 Occupational Safety and Health Administration standard (5 μg m(-3)) and the efficiency was >90%. The process also increased fume particle size from a mode size of 20 nm under baseline conditions to 180-300 nm when TMS was added in all shielding gas flow rates tested. SiO(2) particles formed in the process scavenged nanosized fume particles through intercoagulation. Transmission electron microscopy imagery provided visual evidence of an amorphous film of SiO(2) on some fume particles along with the presence of amorphous SiO(2) agglomerates. These results demonstrate the ability of vapor phase silica precursors to increase welding fume particle size and minimize chromium oxidation, thereby preventing the formation of hexavalent chromium. PMID:22104317

  2. From lab to industrial: PZT nanoparticles synthesis and process control for application in additive manufacturing

    NASA Astrophysics Data System (ADS)

    Huang, Hsien-Lin

    Lead Zirconate Titanate (PZT) nanoparticles hold many promising current and future applications, such as PZT ink for 3-D printing or seeds for PZT thick films. One common method is hydrothermal growth, in which temperature, duration time, or mineralizer concentrations are optimized to produce PZT nanoparticles with desired morphology, controlled size and size distribution. A modified hydrothermal process is used to fabricate PZT nanoparticles. The novelty is to employ a high ramping rate (e.g., 20 deg C/min) to generate abrupt supersaturation so as to promote burst nucleation of PZT nanoparticles as well as a fast cooling rate (e.g., 5 deg C/min) with a controlled termination of crystal growth. As a result, PZT nanoparticles with a size distribution ranging from 200 nm to 800 nm are obtained with cubic morphology and good crystallinity. The identification of nanoparticles is confirmed through use of X-ray diffractometer (XRD). XRD patterns are used to compare sample variations in their microstructures such as lattice parameter. A cubic morphology and particle size are also examined via SEM images. The hydrothermal process is further modified with excess lead (from 20% wt. to 80% wt.) to significantly reduce amorphous phase and agglomeration of the PZT nanoparticles. With a modified process, the particle size still remains within the 200 nm to 800 nm. Also, the crystal structures (microstructure) of the samples show little variations. Finally, a semi-continuous hydrothermal manufacturing process was developed to substantially reduce the fabrication time and maintained the same high quality as the nanoparticles prepared in an earlier stage. In this semi-continuous process, a furnace is maintained at the process temperature (200 deg C), whereas autoclaves containing PZT sol are placed in and out of the furnace to control the ramp-up and cooling rates. This setup eliminates an extremely time-consuming step of cooling down the furnace, thus saving tremendous amount of

  3. Formalin treatments pass new tests. Additional notes on the control of ecto-parasitic protozoa

    USGS Publications Warehouse

    1940-01-01

    After the completion of the eхреriments reported recently, in which the efficacy of formalin in controlling infections of Gostia mecatrix was demonstrated, the author was afforded an opportunity to test the value of formalin solutions in combatting established mixed infections of (Gyrodactylus, Tricbodina, Cyclochaeta) and a stalked protozoan on rainbow trout fingerlings. This opportunity was provided through the courtesy and cooperation of Clarence F. Pautzke, Chief Biologist for the Washington State Game Department, and Lee Walters, Superintendent of the Washington State Hatchery at Seward Park, Seattle.

  4. Mental health problems in adolescents with cochlear implants: peer problems persist after controlling for additional handicaps

    PubMed Central

    Huber, Maria; Burger, Thorsten; Illg, Angelika; Kunze, Silke; Giourgas, Alexandros; Braun, Ludwig; Kröger, Stefanie; Nickisch, Andreas; Rasp, Gerhard; Becker, Andreas; Keilmann, Annerose

    2015-01-01

    The aims of the present multi-center study were to investigate the extent of mental health problems in adolescents with a hearing loss and cochlear implants (CIs) in comparison to normal hearing (NH) peers and to investigate possible relations between the extent of mental health problems of young CI users and hearing variables, such as age at implantation, or functional gain of CI. The survey included 140 adolescents with CI (mean age = 14.7, SD = 1.5 years) and 140 NH adolescents (mean age = 14.8, SD = 1.4 years), their parents and teachers. Participants were matched by age, gender and social background. Within the CI group, 35 adolescents were identified as “risk cases” due to possible and manifest additional handicaps, and 11 adolescents were non-classifiable. Mental health problems were assessed with the Strengths and Difficulties Questionnaire (SDQ) in the versions “Self,” “Parent,” and “Teacher.” The CI group showed significantly more “Peer Problems” than the NH group. When the CI group was split into a “risk-group” (35 “risk cases” and 11 non-classifiable persons) and a “non-risk group” (n = 94), increased peer problems were perceived in both CI subgroups by adolescents themselves. However, no further differences between the CI non-risk group and the NH group were observed in any rater. The CI risk-group showed significantly more hyperactivity compared to the NH group and more hyperactivity and conduct problems compared to the CI non-risk group. Cluster analyses confirmed that there were significantly more adolescents with high problems in the CI risk-group compared to the CI non-risk group and the NH group. Adolescents with CI, who were able to understand speech in noise had significantly less difficulties compared to constricted CI users. Parents, teachers, and clinicians should be aware that CI users with additionally special needs may have mental health problems. However, peer problems were also experienced by CI

  5. Sodium Bicarbonate Prevents Contrast-Induced Nephropathy in Addition to Theophylline: A Randomized Controlled Trial.

    PubMed

    Huber, Wolfgang; Huber, Toni; Baum, Stephan; Franzen, Michael; Schmidt, Christian; Stadlbauer, Thomas; Beitz, Analena; Schmid, Roland M; Schmid, Sebastian

    2016-05-01

    In this study, we investigated whether hydration with sodium bicarbonate is superior to hydration with saline in addition to theophylline (both groups) in the prophylaxis of contrast-induced nephropathy (CIN). It was a prospective, randomized, double-blinded study in a university hospital on 2 general intensive care units (63% of investigations) and normal wards.After approval of the local ethics committee and informed consent 152 patients with screening serum creatinine ≥1.1 mg/dL and/or at least 1 additional risk factor for CIN undergoing intravascular contrast media (CM) exposure were randomized to receive a total of 9 mL/kg bicarbonate 154 mmol/L (group B; n = 74) or saline 0.9% (group S; n = 78) hydration within 7 h in addition to intravenous application of 200 mg theophylline. Serum creatinine was determined immediately before, 24 and 48 h after CM exposure. As primary endpoint we investigated the incidence of CIN (increase of serum creatinine ≥0.5 mg/dL and/or ≥25% within 48 h of CM).Both groups were comparable regarding baseline characteristics. Incidence of CIN was significantly less frequent with bicarbonate compared to sodium hydration (1/74 [1.4%] vs 7/78 [9.0%]; P = 0.035). Time course of serum creatinine was more favorable in group B with decreases in serum creatinine after 24 h (-0.084 mg/dL [95% confidence interval: -0.035 to -0.133 mg/dL]; P = 0.008) and 48 h (-0.093 mg/dL (-0.025 to -0.161 mg/dL); P = 0.007) compared to baseline which were not observed in group S.In patients at increased risk of CIN receiving prophylactic theophylline, hydration with sodium bicarbonate reduces contrast-induced renal impairment compared to hydration with saline. PMID:27227933

  6. Designing a Hybrid Laminar-Flow Control Experiment: The CFD-Experiment Connection

    NASA Technical Reports Server (NTRS)

    Streett, C. L.

    2003-01-01

    The NASA/Boeing hybrid laminar flow control (HLFC) experiment, designed during 1993-1994 and conducted in the NASA LaRC 8-foot Transonic Pressure Tunnel in 1995, utilized computational fluid dynamics and numerical simulation of complex fluid mechanics to an unprecedented extent for the design of the test article and measurement equipment. CFD was used in: the design of the test wing, which was carried from definition of desired disturbance growth characteristics, through to the final airfoil shape that would produce those growth characteristics; the design of the suction-surface perforation pattern that produced enhanced crossflow-disturbance growth: and in the design of the hot-wire traverse system that produced minimal influence on measured disturbance growth. These and other aspects of the design of the test are discussed, after the historical and technical context of the experiment is described.

  7. Dynamics of spacecraft control laboratory experiment (SCOLE) slew maneuvers

    NASA Technical Reports Server (NTRS)

    Kakad, Y. P.

    1987-01-01

    This is the first of two reports on the dynamics and control of slewing maneuvers of the NASA Spacecraft Control Laboratory Experiment (SCOLE). In this report, the dynamics of slewing maneuvers of SCOLE are developed in terms of an arbitrary maneuver about any given axis. The set of dynamical equations incorporate rigid-body slew maneuver and three-dimensional vibrations of the complete assembly comprising the rigid shuttle, the flexible beam, and the reflector with an offset mass. The analysis also includes kinematic nonlinearities of the entire assembly during the maneuver and the dynamics of the interaction between the rigid shuttle and the flexible appendage. The final set of dynamical equations obtained for slewing maneuvers is highly nonlinear and coupled in terms of the flexible modes and the rigid-body modes. The equations are further simplified and evaluated numerically to include the first ten flexible modes and the SCOLE data to yield a model for designing control systems to perform slew maneuvers.

  8. Control strategies against Campylobacter at the poultry production level: biosecurity measures, feed additives and vaccination.

    PubMed

    Meunier, M; Guyard-Nicodème, M; Dory, D; Chemaly, M

    2016-05-01

    Campylobacteriosis is the most prevalent bacterial foodborne gastroenteritis affecting humans in the European Union, and ranks second in the United States only behind salmonellosis. In Europe, there are about nine million cases of campylobacteriosis every year, making the disease a major public health issue. Human cases are mainly caused by the zoonotic pathogen Campylobacter jejuni. The main source of contamination is handling or consumption of poultry meat. Poultry constitutes the main reservoir of Campylobacter, substantial quantities of which are found in the intestines following rapid, intense colonization. Reducing Campylobacter levels in the poultry chain would decrease the incidence of human campylobacteriosis. As primary production is a crucial step in Campylobacter poultry contamination, controlling the infection at this level could impact the following links along the food chain (slaughter, retail and consumption). This review describes the control strategies implemented during the past few decades in primary poultry production, including the most recent studies. In fact, the implementation of biosecurity and hygiene measures is described, as well as the immune strategy with passive immunization and vaccination trials and the nutritional strategy with the administration of organic and fatty acids, essential oil and plant-derived compound, probiotics, bacteriocins and bacteriophages. PMID:26541243

  9. 40 CFR 82.18 - Availability of production in addition to baseline production allowances for class II controlled...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Availability of production in addition to baseline production allowances for class II controlled substances. 82.18 Section 82.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production and...

  10. 40 CFR 82.18 - Availability of production in addition to baseline production allowances for class II controlled...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Availability of production in addition to baseline production allowances for class II controlled substances. 82.18 Section 82.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production and...

  11. 78 FR 74218 - Imposition of Additional Sanctions on Syria Under the Chemical and Biological Weapons Control and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... Imposition of Additional Sanctions on Syria Under the Chemical and Biological Weapons Control and Warfare.... ACTION: Notice. SUMMARY: On August 2, 2013, a determination was made that the Government of Syria used... Notice 8460. That determination resulted in sanctions against the Government of Syria. Section 307(b)...

  12. Powder Layer Preparation Using Vibration-controlled Capillary Steel Nozzles for Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Stichel, Thomas; Laumer, Tobias; Baumüller, Tobias; Amend, Philipp; Roth, Stephan

    In this report, the dry delivery of polyamide 12 powders by vibrating capillary steel nozzles is investigated and discussed regarding its potential for powder layer preparation in Laser Beam Melting. Therefore, a setup including a steel nozzle assembled on a piezoelectric actuator is presented, which enables the precise control over very small powder quantities by vibration excitation. An analysis reveals that the mass flow through the nozzle can be adjusted by the vibration modes in a certain range depending on the nozzle's specifications, whereas the vibration modes themselves show a complicated behaviour. Using a positioning system in combination with the vibrating nozzle, single-layer patterns consisting of polyamide 12 are produced and characterized regarding surface homogeneity and selectivity using a laser stripe sensor.

  13. Summary of Previous Chamber or Controlled Anthrax Studies and Recommendations for Possible Additional Studies

    SciTech Connect

    Piepel, Gregory F.; Amidan, Brett G.; Morrow, Jayne B.

    2010-12-29

    This report and an associated Excel file(a) summarizes the investigations and results of previous chamber and controlled studies(b) to characterize the performance of methods for collecting, storing and/or transporting, extracting, and analyzing samples from surfaces contaminated by Bacillus anthracis (BA) or related simulants. This report and the Excel are the joint work of the Pacific Northwest National Laboratory (PNNL) and the National Institute of Standards and Technology (NIST) for the Department of Homeland Security, Science and Technology Directorate. The report was originally released as PNNL-SA-69338, Rev. 0 in November 2009 with limited distribution, but was subsequently cleared for release with unlimited distribution in this Rev. 1. Only minor changes were made to Rev. 0 to yield Rev. 1. A more substantial update (including summarizing data from other studies and more condensed summary tables of data) is underway

  14. The effect of additional design parameters on the LQR based design of a control/structural system

    NASA Technical Reports Server (NTRS)

    Bainum, Peter M.; Xu, Jianke

    1990-01-01

    A multiobjective cost function that includes a form of the standard LQR regulator cost and its partial variation with respect to the additional design parameters is presented in connection with the design of an orbiting control/structural system. Simple models of uniform solid and tubular beams are demonstrated with two typical additional payload masses, i.e., symmetrically distributed and asymmetrically distributed, with respect to the center of the beam. By regarding the transient response of pitch angle and free-free beam deformations in the orbital plane, the optimal outer diameter of the beam and all feedback control can be determined by numerical analysis with this multicriterial approach. It is concluded that the multicriteria design approach should give better results from both the structural designer's and the control designer's standpoints.

  15. Sulfosuccinate and Sulfocarballylate Surfactants As Charge Control Additives in Nonpolar Solvents.

    PubMed

    Smith, Gregory N; Kemp, Roger; Pegg, Jonathan C; Rogers, Sarah E; Eastoe, Julian

    2015-12-29

    A series of eight sodium sulfonic acid surfactants with differently branched tails (four double-chain sulfosuccinates and four triple-chain sulfocarballylates) were studied as charging agents for sterically stabilized poly(methyl methacrylate) (PMMA) latexes in dodecane. Tail branching was found to have no significant effect on the electrophoretic mobility of the latexes, but the number of tails was found to influence the electrophoretic mobility. Triple-chain, sulfocarballylate surfactants were found to be more effective. Several possible origins of this observation were explored by comparing sodium dioctylsulfosuccinate (AOT1) and sodium trioctylsulfocarballylate (TC1) using identical approaches: the inverse micelle size, the propensity for ion dissociation, the electrical conductivity, the electrokinetic or ζ potential, and contrast-variation small-angle neutron scattering. The most likely origin of the increased ability of TC1 to charge PMMA latexes is a larger number of inverse micelles. These experiments demonstrate a small molecular variation that can be made to influence the ability of surfactants to charge particles in nonpolar solvents, and modifying molecular structure is a promising approach to developing more effective charging agents. PMID:26609708

  16. Additional Analgesia for Central Venous Catheter Insertion: A Placebo Controlled Randomized Trial of Dexmedetomidine and Fentanyl

    PubMed Central

    Samantaray, Aloka; Hanumantha Rao, Mangu; Sahu, Chitta Ranjan

    2016-01-01

    We aimed to show that a single preprocedural dose of either dexmedetomidine or fentanyl reduces procedural pain and discomfort and provides clinically acceptable sedation. In this prospective, double-blind study, sixty patients scheduled for elective surgery and requiring planned central venous catheter insertion were randomized to receive dexmedetomidine (1 μg/kg), fentanyl (1 μg/kg), or 0.9% normal saline intravenously over ten minutes followed by local anesthetic field infiltration before attempting central venous catheterization. The primary outcome measures are assessment and analysis of pain, discomfort, and sedation level before, during, and after the central venous catheter insertion at five time points. The median (IQR) pain score is worst for normal saline group at local anaesthetic injection [6 (4–6.7)] which was significantly attenuated by addition of fentanyl [3 (2–4)] and dexmedetomidine [4 (3–5)] in the immediate postprocedural period (P = 0.001). However, the procedure related discomfort was significantly lower in dexmedetomidine group compared to fentanyl group in the first 10 min of procedure after local anaesthetic Injection (P = 0.001). Fentanyl is more analgesically efficient for central venous catheter insertion along with local anaesthetic injection. However, dexmedetomidine has the potential to be superior to fentanyl and placebo in terms of providing comfort to the patients during the procedure. PMID:27200187

  17. Additional Analgesia for Central Venous Catheter Insertion: A Placebo Controlled Randomized Trial of Dexmedetomidine and Fentanyl.

    PubMed

    Samantaray, Aloka; Hanumantha Rao, Mangu; Sahu, Chitta Ranjan

    2016-01-01

    We aimed to show that a single preprocedural dose of either dexmedetomidine or fentanyl reduces procedural pain and discomfort and provides clinically acceptable sedation. In this prospective, double-blind study, sixty patients scheduled for elective surgery and requiring planned central venous catheter insertion were randomized to receive dexmedetomidine (1 μg/kg), fentanyl (1 μg/kg), or 0.9% normal saline intravenously over ten minutes followed by local anesthetic field infiltration before attempting central venous catheterization. The primary outcome measures are assessment and analysis of pain, discomfort, and sedation level before, during, and after the central venous catheter insertion at five time points. The median (IQR) pain score is worst for normal saline group at local anaesthetic injection [6 (4-6.7)] which was significantly attenuated by addition of fentanyl [3 (2-4)] and dexmedetomidine [4 (3-5)] in the immediate postprocedural period (P = 0.001). However, the procedure related discomfort was significantly lower in dexmedetomidine group compared to fentanyl group in the first 10 min of procedure after local anaesthetic Injection (P = 0.001). Fentanyl is more analgesically efficient for central venous catheter insertion along with local anaesthetic injection. However, dexmedetomidine has the potential to be superior to fentanyl and placebo in terms of providing comfort to the patients during the procedure. PMID:27200187

  18. Foreword: Additive Manufacturing: Interrelationships of Fabrication, Constitutive Relationships Targeting Performance, and Feedback to Process Control

    DOE PAGESBeta

    Carpenter, John S.; Beese, Allison M.; Bourell, David L.; Hamilton, Reginald F.; Mishra, Rajiv; Sears, James

    2015-06-26

    Additive manufacturing (AM) offers distinct advantages over conventional manufacturing processes including the capability to both build and repair complex part shapes; to integrate and consolidate parts and thus overcome joining concerns; and to locally tailor material compositions as well as properties. Moreover, a variety of fields such as aerospace, military, automotive, and biomedical are employing this manufacturing technique as a way to decrease costs, increase manufacturing agility, and explore novel geometry/functionalities. In order to increase acceptance of AM as a viable processing method, pathways for qualifying both the material and the process need to be developed and, perhaps, standardized. Thismore » symposium was designed to serve as a venue for the international AM community—including government, academia, and industry—to define the fundamental interrelationships between feedstock, processing, microstructure, shape, mechanical behavior/materials properties, and function/performance. Eventually, insight into the connections between processing, microstructure, property, and performance will be achieved through experimental observations, theoretical advances, and computational modeling of physical processes. Finally, once this insight matures, AM will be able to move from the realm of making parts to making qualified materials that are certified for use with minimal need for post-fabrication characterization.« less

  19. Roles of additives and surface control in slurry atomization. Final project report

    SciTech Connect

    Tsai, S.C.

    1992-12-31

    This project studies the rheology and airblast atomization of micronized coal slurries. Its major objectives are (1) to promote further understanding of the mechanisms and the roles of additives in airblast atomization of coal water slurry (CWS), and (2) to investigate the impacts of coal particle surface properties and interparticle forces on CWS rheology. We have found that the flow behavior index (n) of a suspension (or slurry) is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The interparticle attraction, measured by the Hamaker constant scaled to the thermal energy at 25{degrees}C (A/kT), causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior (n< 1). At a constant particle volume fraction and surface charge density (qualitatively measured by the zeta potential in deionized water), n decreases linearly as A/kT increases. The relative viscosity of the pseudoplastic suspension with respect to that of the suspending liquid is found to be independent of particle density and correlate well with the particle Peclet number which equals the particle diffusional relaxation time multiplied by shear rate. Specifically, the relative viscosities of the pseudoplastic glycerol/water coal slurry and the ethylene glycol/glycerol sand slurry, at same volume fractions as well as similar particle size distributions and liquid viscosities, as functions of the particle Peclet number fall along the same line.

  20. Foreword: Additive Manufacturing: Interrelationships of Fabrication, Constitutive Relationships Targeting Performance, and Feedback to Process Control

    SciTech Connect

    Carpenter, John S.; Beese, Allison M.; Bourell, David L.; Hamilton, Reginald F.; Mishra, Rajiv; Sears, James

    2015-06-26

    Additive manufacturing (AM) offers distinct advantages over conventional manufacturing processes including the capability to both build and repair complex part shapes; to integrate and consolidate parts and thus overcome joining concerns; and to locally tailor material compositions as well as properties. Moreover, a variety of fields such as aerospace, military, automotive, and biomedical are employing this manufacturing technique as a way to decrease costs, increase manufacturing agility, and explore novel geometry/functionalities. In order to increase acceptance of AM as a viable processing method, pathways for qualifying both the material and the process need to be developed and, perhaps, standardized. This symposium was designed to serve as a venue for the international AM community—including government, academia, and industry—to define the fundamental interrelationships between feedstock, processing, microstructure, shape, mechanical behavior/materials properties, and function/performance. Eventually, insight into the connections between processing, microstructure, property, and performance will be achieved through experimental observations, theoretical advances, and computational modeling of physical processes. Finally, once this insight matures, AM will be able to move from the realm of making parts to making qualified materials that are certified for use with minimal need for post-fabrication characterization.

  1. Synthetic clay-magnetite aggregates designed for controlled deposition experiments

    NASA Astrophysics Data System (ADS)

    Feinberg, J. M.; Galindo-Gonzalez, C.; Kasama, T.; Cervera, L.; Posfai, M.; Harrison, R. J.; Dunin-Borkowski, R. E.

    2007-12-01

    The behavior of magnetic particles in fluid environments is key to the acquisition of detrital remanence magnetization and is essential to a multitude of industrial applications. This study introduces a series of synthetic clay-magnetite aggregates whose physical attributes can be tailored for controlled depositional experiments. We describe the mineralogical structure and magnetic behavior of montmorillonite platelets coated with nanometer-scale magnetite crystals using both electron microscopy and rock magnetism techniques. Selected area electron diffraction of the magnetite and the montmorillonite host shows no evidence of preferred orientation or oriented aggregation. Grain size distributions of magnetite in three different clay-magnetite assemblages were directly measured using conventional bright-field transmission electron microscopy. The spacing of the magnetite grains and their three-dimensional distribution around individual clay platelets was imaged using a tomographic reconstruction generated from high-angle annular dark-field (HAADF) images. The grain size distributions determined from the bright-field images and the tomographic reconstruction agree within error with estimates derived from magnetic granulometry techniques based on magnetic hysteresis and low-field susceptibility measurements. All three samples behave superparamagnetically at room temperature, and display increasing levels of single domain behavior as the samples are cooled to liquid nitrogen temperatures (- 195°C). Off-axis electron holography images show that superparamagnetic grains are also stabilized into flux closure structures at -195°C. The average spacing between adjacent magnetite crystals and the overall platelet shape of the aggregates creates an anisotropy of magnetic susceptibility that allows assemblages to align with external magnetic fields at room temperature. By adjusting the dimensions and concentrations of the magnetite grains in these aggregates, we can create

  2. Controlling Phase Separation of Tough Interpenetrating Polymer Networks via Addition of Amphiphilic Block Copolymers

    NASA Astrophysics Data System (ADS)

    Rohde, Brian; Krishnamoorti, Ramanan; Robertson, Megan

    Interpenetrating polymer networks (IPNs) offer a unique way to combine the mechanical properties of two thermoset systems. Often used to create a material that possesses both high toughness and tensile properties, here we use polydicyclopentadiene, cured via ring opening metathesis polymerization, to contribute high toughness and diglycidyl ether of bisphenol A cured via anhydride chemistry to contribute high tensile strength and modulus. As the uncompatibilized system reacts in the presence of one another, mesoscopic phase separation occurs and dictates the overall efficacy of combining mechanical properties. To control phase separation and drive the system towards more mechanically robust nanostructed IPNs, amphiphilic block copolymers of polybutadiene- b-polyethylene oxide, where one block possesses strong affinity to polyDCPD and the other the DGEBA, were added to the system. Here we present a systematic study of the influence of block copolymer composition in the overall blend on degree of phase separation and morphology using a combination of small-angle x-ray scattering (SAXS) and scanning electron microscopy (SEM) techniques. The resultant mechanical properties are then explored in an effort to link mechanical properties to blend morphology.

  3. Controlling Phase Separation of Interpenetrating Polymer Networks by Addition of Block Copolymers

    NASA Astrophysics Data System (ADS)

    Rohde, Brian; Krishnamoorti, Ramanan; Robertson, Megan

    2015-03-01

    Interpenetrating polymer networks (IPNs) offer a unique way to produce mechanically superior thermoset blends relative to the neat components. In this study, IPNs were prepared consisting of polydicyclopentadiene (polyDCPD), contributing high fracture toughness, and an epoxy resin (the diglycidyl ether of bisphenol A cured with nadic methyl anhydride), contributing high tensile strength and modulus. In the absence of compatibilization, the simultaneous curing of the networks leads to a macroscopically phase separated blend that exhibits poor mechanical behavior. To control phase separation and drive the system towards more mechanically robust nanostructured IPNs, block copolymers were designed to compatibilize this system, where one block possesses affinity to polyDCPD (polynorbornene in this study) and the other block possesses affinity to DGEBA (poly(ɛ-caprolactone) in this study). The influence of the block copolymer composition on the degree of phase separation and interfacial adhesion in the IPN was studied using a combination of small-angle scattering and imaging techniques. The resultant mechanical properties were explored and structure-property relationships were developed in this blend system.

  4. A General Purpose Experiment Controller for low cost Space Application

    NASA Astrophysics Data System (ADS)

    Guzman-Garcia, D.; Rowland, D. E.; Uribe, P.; Nieves-Chinchilla, T.

    2012-12-01

    Space activities are very expensive and include a high degree of risk. Nowadays, CubeSat missions represent a fast and inexpensive way to conduct scientific space research. These platforms are less expensive to develop and build than conventional satellites. There are ample demonstration that these platforms are well suited for a wide range of science missions in different fields, such as astrobiology, astronomy, atmospheric science, space weather and biology. This paper presents a hybrid "processor in an Field Programmable Gate Array (FPGA)" experiment/spacecraft controller for Cubesat missions. The system has two objectives, first is to obtain a multipurpose and easily customizable system aimed at processing the data from the widest kind of instruments and second, to provide the system with the highest processing capabilities in order to be able to perform complex onboard algorithms. Due to the versatility of the system and its reduced dimensions, it can be employed in different space platforms. The system is envisioned to be employed for the first time as the smart radio receiver for the upcoming NASA FireStation instrument. It is one of four experiments manifested to fly on an experiment pallet the U.S Department of Defense plans to deploy on the International Space Station in 2013. FireStation will continue analyzing the link between the Lightning and the Terrestrial Gamma Rays initiated by the FireFly Cubesat. The system is responsible for the management of a set of small Heliophysics instrumentats, including a photometer, magnetometer, and electric and magnetic field antennas. A description of the system architecture and its main features are presented. The main functional and performance tests during the integration and calibration phase of the instruments are also discussed.

  5. Remote Control and Monitoring of VLBI Experiments by Smartphones

    NASA Astrophysics Data System (ADS)

    Ruztort, C. H.; Hase, H.; Zapata, O.; Pedreros, F.

    2012-12-01

    For the remote control and monitoring of VLBI operations, we developed a software optimized for smartphones. This is a new tool based on a client-server architecture with a Web interface optimized for smartphone screens and cellphone networks. The server uses variables of the Field System and its station specific parameters stored in the shared memory. The client running on the smartphone by a Web interface analyzes and visualizes the current status of the radio telescope, receiver, schedule, and recorder. In addition, it allows commands to be sent remotely to the Field System computer and displays the log entries. The user has full access to the entire operation process, which is important in emergency cases. The software also integrates a webcam interface.

  6. Stratospheric controlled perturbation experiment: a small-scale experiment to improve understanding of the risks of solar geoengineering.

    PubMed

    Dykema, John A; Keith, David W; Anderson, James G; Weisenstein, Debra

    2014-12-28

    Although solar radiation management (SRM) through stratospheric aerosol methods has the potential to mitigate impacts of climate change, our current knowledge of stratospheric processes suggests that these methods may entail significant risks. In addition to the risks associated with current knowledge, the possibility of 'unknown unknowns' exists that could significantly alter the risk assessment relative to our current understanding. While laboratory experimentation can improve the current state of knowledge and atmospheric models can assess large-scale climate response, they cannot capture possible unknown chemistry or represent the full range of interactive atmospheric chemical physics. Small-scale, in situ experimentation under well-regulated circumstances can begin to remove some of these uncertainties. This experiment-provisionally titled the stratospheric controlled perturbation experiment-is under development and will only proceed with transparent and predominantly governmental funding and independent risk assessment. We describe the scientific and technical foundation for performing, under external oversight, small-scale experiments to quantify the risks posed by SRM to activation of halogen species and subsequent erosion of stratospheric ozone. The paper's scope includes selection of the measurement platform, relevant aspects of stratospheric meteorology, operational considerations and instrument design and engineering. PMID:25404681

  7. Addition of Lidocaine Injection Immediately before Physiotherapy for Frozen Shoulder: A Randomized Controlled Trial

    PubMed Central

    Hsu, Wei-Chun; Wang, Tao-Liang; Lin, Yi-Jia; Hsieh, Lin-Fen; Tsai, Chun-Mei; Huang, Kuang-Hui

    2015-01-01

    The intraarticular injection of lidocaine immediately before a physiotherapy session may relieve pain during the stretching and mobilization of the affected joint in patients with a frozen shoulder, thus enhancing the treatment effect. To compare the effects of intraarticular injection of lidocaine plus physiotherapy to that of physiotherapy alone in the treatment of a frozen shoulder, a prospective randomized controlled trial was conducted in the rehabilitation department of a private teaching hospital. Patients with a frozen shoulder were randomized into the physiotherapy group or the lidocaine injection plus physiotherapy (INJPT) group. The subjects in the INJPT group underwent injection of 3 ml of 1% lidocaine into the affected shoulder 10 to 20 minutes before each physiotherapy session. In each group, the treatment lasted 3 months. The primary outcome measures were the active and passive range of motion of the affected shoulder. The secondary outcome measures were the results of the Shoulder Disability Questionnaire, the Shoulder Pain and Disability Index, and the 36-item Short-Form Health Survey (SF-36). The outcome measures were evaluated before treatment and 1, 2, 3, 4, and 6 months after the start of treatment. The group comparisons showed significantly greater improvement in the INJPT group, mainly in active and passive shoulder range of motion in flexion and external rotation and improvements in pain and disability (P < 0.05); however, no significant group difference was seen in the SF-36 results. The intraarticular injection of lidocaine immediately before a physiotherapy session might be superior to physiotherapy alone in the treatment of a frozen shoulder. Trial Registration ClinicalTrials.gov NCT01817348 PMID:25714415

  8. Precise control of polymer coated nanopores by nanoparticle additives: Insights from computational modeling

    NASA Astrophysics Data System (ADS)

    Eskandari Nasrabad, Afshin; Jasnow, David; Zilman, Anton; Coalson, Rob D.

    2016-08-01

    Polymer-nanoparticle composites are a promising new class of materials for creation of controllable nano-patterned surfaces and nanopores. We use coarse-grained molecular dynamics simulations augmented with analytical theory to study the structural transitions of surface grafted polymer layers (brushes) induced by infiltration of nanoparticles that are attracted to the polymers in the layer. We systematically compare two different polymer brush geometries: one where the polymer chains are grafted to a planar surface and the other where the chains are grafted to the inside of a cylindrical nanochannel. We perform a comprehensive study of the effects of the material parameters such as the polymer chain length, chain grafting density, nanoparticle size, strength of attraction between nanoparticles and polymer monomers, and, in the case of the cylindrically grafted brush, the radius of the cylinder. We find a very general behavioral motif for all geometries and parameter values: the height of the polymer brush is non-monotonic in the nanoparticle concentration in solution. As the nanoparticle concentration increases, the brush height first decreases and after passing through a minimum value begins to increase, resulting in the swelling of the nanoparticle infused brush. These morphological features may be useful for devising tunable "smart" nano-devices whose effective dimensions can be reversibly and precisely adjusted by changing the nanoparticle concentration in solution. The results of approximate Self-Consistent Field Theory (SCFT) calculations, applicable in the regime of strong brush stretching, are compared to the simulation results. The SCFT calculations are found to be qualitatively, even semi-quantitatively, accurate when applied within their intended regime of validity, and provide a useful and efficient tool for modeling such materials.

  9. Ring Walking/Oxidative Addition Reactions for the Controlled Synthesis of Conjugated Polymers

    SciTech Connect

    Bazan, Guillermo C

    2012-04-03

    Power conversion efficiencies of plastic solar cells depend strongly on the molecular weight characteristics of the semiconducting polymers used for their fabrication. The synthesis of these materials typically relies on transition metal mediated catalytic reactions. In many instances, the ideal structures cannot be attained because of deficiencies in these reactions, particularly when it comes to being able to achieve high number average molecular weights and narrow molecular weight distributions. Another important conjugated polymer structure of interest is one in which a single functional group is attached at the end group of the chain. Such systems would be ideal for modifying surface properties at interfaces and for labeling biomolecular probes used in fluorescent biosensors. To respond to the challenges above, our efforts have centered on the design of homogenous transition metal complexes that are easy to prepare and effective in carrying out living, or quasi-living, condensative chain polymerization reactions. The key mechanistic challenge for the success of this reaction is to force the insertion of one monomer unit at a time via a process that involves migration of the transition metal-containing fragment to one terminus of the polymer chain. Chain growth characteristics are therefore favored when the metal does not dissociate from the newly formed reductive elimination product. We have proposed that dissociation is disfavored by the formation of a -complex, in which the metal can sample various locations of the electronically delocalized framework, a process that we term ring-walking , and find the functionality where oxidative addition takes place. Success has been achieved in the nickel-mediated cross coupling reaction of Grignard reagents with aromatic halides by using bromo[1,2-bis(diphenylphosphino)ethane]phenylnickel. This reagent can yield poly(thiophene)s (one of the most widely used type of polymer in plastic solar cells) with excellent

  10. The 5th Annual NASA Spacecraft Control Laboratory Experiment (SCOLE) Workshop, part 2

    NASA Technical Reports Server (NTRS)

    Taylor, Lawrence W., Jr. (Compiler)

    1990-01-01

    A collection of papers from the workshop are presented. The topics addressed include: the modeling, systems identification, and control synthesis for the Spacecraft Control Laboratory Experiment (SCOLE) configuration.

  11. AMO EXPRESS: A Command and Control Experiment for Crew Autonomy

    NASA Technical Reports Server (NTRS)

    Stetson, Howard K.; Frank, Jeremy; Cornelius, Randy; Haddock, Angie; Wang, Lui; Garner, Larry

    2015-01-01

    NASA is investigating a range of future human spaceflight missions, including both Mars-distance and Near Earth Object (NEO) targets. Of significant importance for these missions is the balance between crew autonomy and vehicle automation. As distance from Earth results in increasing communication delays, future crews need both the capability and authority to independently make decisions. However, small crews cannot take on all functions performed by ground today, and so vehicles must be more automated to reduce the crew workload for such missions. NASA's Advanced Exploration Systems Program funded Autonomous Mission Operations (AMO) project conducted an autonomous command and control demonstration of intelligent procedures to automatically initialize a rack onboard the International Space Station (ISS) with power and thermal interfaces, and involving core and payload command and telemetry processing, without support from ground controllers. This autonomous operations capability is enabling in scenarios such as a crew medical emergency, and representative of other spacecraft autonomy challenges. The experiment was conducted using the Expedite the Processing of Experiments for Space Station (EXPRESS) rack 7, which was located in the Port 2 location within the U.S Laboratory onboard the International Space Station (ISS). Activation and deactivation of this facility is time consuming and operationally intensive, requiring coordination of three flight control positions, 47 nominal steps, 57 commands, 276 telemetry checks, and coordination of multiple ISS systems (both core and payload). The autonomous operations concept includes a reduction of the amount of data a crew operator is required to verify during activation or de-activation, as well as integration of procedure execution status and relevant data in a single integrated display. During execution, the auto-procedures provide a step-by-step messaging paradigm and a high level status upon termination. This

  12. Effect of pore size on bone ingrowth into porous titanium implants fabricated by additive manufacturing: An in vivo experiment.

    PubMed

    Taniguchi, Naoya; Fujibayashi, Shunsuke; Takemoto, Mitsuru; Sasaki, Kiyoyuki; Otsuki, Bungo; Nakamura, Takashi; Matsushita, Tomiharu; Kokubo, Tadashi; Matsuda, Shuichi

    2016-02-01

    Selective laser melting (SLM) is an additive manufacturing technique with the ability to produce metallic scaffolds with accurately controlled pore size, porosity, and interconnectivity for orthopedic applications. However, the optimal pore structure of porous titanium manufactured by SLM remains unclear. In this study, we evaluated the effect of pore size with constant porosity on in vivo bone ingrowth in rabbits into porous titanium implants manufactured by SLM. Three porous titanium implants (with an intended porosity of 65% and pore sizes of 300, 600, and 900μm, designated the P300, P600, and P900 implants, respectively) were manufactured by SLM. A diamond lattice was adapted as the basic structure. Their porous structures were evaluated and verified using microfocus X-ray computed tomography. Their bone-implant fixation ability was evaluated by their implantation as porous-surfaced titanium plates into the cortical bone of the rabbit tibia. Bone ingrowth was evaluated by their implantation as cylindrical porous titanium implants into the cancellous bone of the rabbit femur for 2, 4, and 8weeks. The average pore sizes of the P300, P600, and P900 implants were 309, 632, and 956μm, respectively. The P600 implant demonstrated a significantly higher fixation ability at 2weeks than the other implants. After 4weeks, all models had sufficiently high fixation ability in a detaching test. Bone ingrowth into the P300 implant was lower than into the other implants at 4weeks. Because of its appropriate mechanical strength, high fixation ability, and rapid bone ingrowth, our results indicate that the pore structure of the P600 implant is a suitable porous structure for orthopedic implants manufactured by SLM. PMID:26652423

  13. Dynamics and control of multipayload platforms - The Middeck Active Control Experiment (MACE)

    NASA Technical Reports Server (NTRS)

    Miller, David W.; Crawley, Edward F.; De Luis, Javier

    1990-01-01

    A flight experiment entitled the Middeck Active Control Experiment (MACE) proposed by the Space Engineering Research Center (SERC) at the Massachusetts Institute of Technology is described. The objective of this program is to investigate and validate the modeling of the dynamics of an actively controlled flexible, articulating, multibody platform free floating in zero gravity. A rationale and experimental approach for the program are presented. The rationale shows that on-orbit testing, coupled with ground testing and a strong analytical program, is necessary in order to fully understand both how flexibility of the platform affects the pointing problem, as well as how gravity perturbs this structural flexibility causing deviations between 1-and 0-gravity behavior. The experimental approach captures the essential physics of multibody platforms, by identifying the appropriate attributes, tests, and performance metrics of the test article, and defines the tests required to successfully validate the analytical framework.

  14. Dynamics and control of multipayload platforms. The middeck active control experiment (MACE)

    NASA Astrophysics Data System (ADS)

    Miller, David W.; de Luis, Javier; Crawley, Edward F.

    A flight experiment entitled the Middeck Active Control Experiment (MACE) proposed by the Space Engineering Research Center (SERC) at the Massachusetts Institute of Technology is described. The objective of this program is to investigate and validate the modeling of the dynamics of an actively controlled flexible, articulating, multibody platform free floating in zero gravity. A rationale and experimental approach for the program are presented. The rationale shows that on-orbit testing, coupled with ground testing and a strong analytical program, is necessary in order to fully understand both how flexibility of the platform affects the pointing problem, as well as how gravity perturbs this structural flexibility causing deviations between 1-and 0-gravity behavior. The experimental approach captures the essential physics of multibody platforms, by identifying the appropriate attributes, tests, and performance metrics of the test article, and defines the tests required to successfully validate the analytical framework.

  15. Simultaneous control of acid gases and PAHs using a spray dryer combined with a fabric filter using different additives.

    PubMed

    Liu, Zhen Shu; Wey, Ming Yen; Lin, Chiou Liang

    2002-04-26

    The purpose of this research was to simultaneously evaluate the removal efficiency of acid gases and PAHs from the flue gas emitted by a laboratory incinerator. This flue gas contained dust, acid gases, organics and heavy metals. A spray dryer combined with a fabric filter was used as the air pollution control device (APCD) in this study. The operating conditions investigated included different feedstock additives (polyvinyl chloride (PVC) and NaCl) and spray dryer additives (SiO2, CaCl2 and NaHCO3). The removal efficiency for SO2 could be enhanced by adding inorganic additives, such as SiO2, CaCl2 and NaHCO3. The presence of PVC in the incinerator feedstock also increased the removal efficiency of SO2in the spray dryer. The improved removal of PAHs could be attributed to the addition of feedstock additives (PVC and NaCl) and spray dryer additives (SiO2, CaCl2 and NaHCO3). PMID:11900910

  16. MxCuBE: a synchrotron beamline control environment customized for macromolecular crystallography experiments

    PubMed Central

    Gabadinho, José; Beteva, Antonia; Guijarro, Matias; Rey-Bakaikoa, Vicente; Spruce, Darren; Bowler, Matthew W.; Brockhauser, Sandor; Flot, David; Gordon, Elspeth J.; Hall, David R.; Lavault, Bernard; McCarthy, Andrew A.; McCarthy, Joanne; Mitchell, Edward; Monaco, Stéphanie; Mueller-Dieckmann, Christoph; Nurizzo, Didier; Ravelli, Raimond B. G.; Thibault, Xavier; Walsh, Martin A.; Leonard, Gordon A.; McSweeney, Sean M.

    2010-01-01

    The design and features of a beamline control software system for macromolecular crystallography (MX) experiments developed at the European Synchrotron Radiation Facility (ESRF) are described. This system, MxCuBE, allows users to easily and simply interact with beamline hardware components and provides automated routines for common tasks in the operation of a synchrotron beamline dedicated to experiments in MX. Additional functionality is provided through intuitive interfaces that enable the assessment of the diffraction characteristics of samples, experiment planning, automatic data collection and the on-line collection and analysis of X-ray emission spectra. The software can be run in a tandem client-server mode that allows for remote control and relevant experimental parameters and results are automatically logged in a relational database, ISPyB. MxCuBE is modular, flexible and extensible and is currently deployed on eight macromolecular crystallography beamlines at the ESRF. Additionally, the software is installed at MAX-lab beamline I911-3 and at BESSY beamline BL14.1. PMID:20724792

  17. Spliced synthetic genes as internal controls in RNA sequencing experiments.

    PubMed

    Hardwick, Simon A; Chen, Wendy Y; Wong, Ted; Deveson, Ira W; Blackburn, James; Andersen, Stacey B; Nielsen, Lars K; Mattick, John S; Mercer, Tim R

    2016-09-01

    RNA sequencing (RNA-seq) can be used to assemble spliced isoforms, quantify expressed genes and provide a global profile of the transcriptome. However, the size and diversity of the transcriptome, the wide dynamic range in gene expression and inherent technical biases confound RNA-seq analysis. We have developed a set of spike-in RNA standards, termed 'sequins' (sequencing spike-ins), that represent full-length spliced mRNA isoforms. Sequins have an entirely artificial sequence with no homology to natural reference genomes, but they align to gene loci encoded on an artificial in silico chromosome. The combination of multiple sequins across a range of concentrations emulates alternative splicing and differential gene expression, and it provides scaling factors for normalization between samples. We demonstrate the use of sequins in RNA-seq experiments to measure sample-specific biases and determine the limits of reliable transcript assembly and quantification in accompanying human RNA samples. In addition, we have designed a complementary set of sequins that represent fusion genes arising from rearrangements of the in silico chromosome to aid in cancer diagnosis. RNA sequins provide a qualitative and quantitative reference with which to navigate the complexity of the human transcriptome. PMID:27502218

  18. Wood smoke in a controlled exposure experiment with human volunteers.

    PubMed

    Riddervold, I S; Bønløkke, J H; Mølhave, L; Massling, A; Jensen, B; Grønborg, T K; Bossi, R; Forchhammer, L; Kjærgaard, S K; Sigsgaard, T

    2011-04-01

    Exposure to wood smoke in the general population is increasing and concurrently, also our awareness. This article describes a wood-smoke generating system for studying human exposure to wood smoke and symptoms related to this exposure. Twenty nonsmoking atopic human participants with normal lung function and normal bronchial reactivity were randomly exposed for 3 h at three different exposure conditions; clean filtered air (control exposure) and wood smoke with a characteristic particulate matter (PM) concentration of 200 µg/m³ (low) and 400 µg/m³ (high) under controlled environmental conditions. The range for PM₂.₅ load observed for single experiments was 165-303 µg/m³ for the low exposure and 205-662 µg/m³ for the high exposure, whereas particle loads during clean air exposure most often were below the detection limit (< 20 µg/m³). Health effects were evaluated in relation to rated changes in symptoms and environmental perception using a computerized questionnaire and a potentiometer. Subjective symptoms were generally weak, but when combining the effect of each of the symptoms into categorical symptom indices, significant effects were found for "environmental perception" (p = 0.0007), "irritative body perceptions" (p = 0.0127), "psychological/neurological effects" (p = 0.0075) and "weak inflammatory responses" (p = 0.0003). Furthermore, significant effects (p = 0.0192) on self-reported general mucosa irritation were found. In conclusion, exposure to wood smoke affected symptom rating and caused irritated mucosas in humans. The knowledge gained in this study on subjective-rated symptoms may be important for understanding human response to wood-smoke exposure. PMID:21506878

  19. Ground control system for the midcourse space experiment UTC clock

    NASA Technical Reports Server (NTRS)

    Dragonette, Richard

    1994-01-01

    One goal of the Midcourse Space Experiment (MSX) spacecraft Operations Planning Center is to maintain the onboard satellite UTC clock (UTC(MSX)) to within 1 millisecond of UTC(APL) (the program requirement is 10 msec). The UTC(MSX) clock employs as its time base an APL built 5 MHz quartz oscillator, which is expected to have frequency instabilities (aging rate + drift rate + frequency offset) that will cause the clock to drift approximately two to ten milliseconds per day. The UTC(MSX) clock can be advanced or retarded by the APL MSX satellite ground control center by integer multiples of 1 millisecond. The MSX Operations Planning Center is developing software which records the drift of UTC(MSX) relative to UTC(APL) and which schedules the time of day and magnitude of UTC(MSX) clock updates up to 48 hours in advance. Because of the manner in which MSX spacecraft activities are scheduled, MSX clock updates are planned 24 to 48 hours in advance, and stored in the satellite's computer controller for later execution. Data will be collected on the drift of UTC(MSX) relative to UTC(APL) over a three to five day period. Approximately six times per day, the time offset between UTC(MSX) and UTC(APL) will be measured by APL with a resolution of less than 100 microseconds. From this data a second order analytical model of the clock's drift will be derived. This model will be used to extrapolate the offset of the MSX clock in time from the present to 48 hours in the future. MSX clock updates will be placed on the spacecraft's daily schedule whenever the predicted clock offset exceeds 0.5 milliseconds. The paper includes a discussion of how the empirical model of the MSX clock is derived from satellite telemetry data, as well as the algorithm used to schedule MSX clock updates based on the model.

  20. The Space Technology-7 Disturbance Reduction System Precision Control Flight Validation Experiment Control System Design

    NASA Technical Reports Server (NTRS)

    O'Donnell, James R.; Hsu, Oscar C.; Maghami, Peirman G.; Markley, F. Landis

    2006-01-01

    As originally proposed, the Space Technology-7 Disturbance Reduction System (DRS) project, managed out of the Jet Propulsion Laboratory, was designed to validate technologies required for future missions such as the Laser Interferometer Space Antenna (LISA). The two technologies to be demonstrated by DRS were Gravitational Reference Sensors (GRSs) and Colloidal MicroNewton Thrusters (CMNTs). Control algorithms being designed by the Dynamic Control System (DCS) team at the Goddard Space Flight Center would control the spacecraft so that it flew about a freely-floating GRS test mass, keeping it centered within its housing. For programmatic reasons, the GRSs were descoped from DRS. The primary goals of the new mission are to validate the performance of the CMNTs and to demonstrate precise spacecraft position control. DRS will fly as a part of the European Space Agency (ESA) LISA Pathfinder (LPF) spacecraft along with a similar ESA experiment, the LISA Technology Package (LTP). With no GRS, the DCS attitude and drag-free control systems make use of the sensor being developed by ESA as a part of the LTP. The control system is designed to maintain the spacecraft s position with respect to the test mass, to within 10 nm/the square root of Hz over the DRS science frequency band of 1 to 30 mHz.

  1. Particle Control in the Sustained Spheromak Physics Experiment

    SciTech Connect

    Wood, R.D.; Hill, D.N.; Hooper, E.B.; Buchenauer, D.; McLean, H.; Wang, Z.; Woodruff, S.; Wurden, G.

    2000-05-01

    In this paper we report on density and impurity measurements in the Sustained Spheromak Physics Experiment (SSPX) which has recently started operation. The SSPX spheromak plasma is sustained by coaxial helicity injection for a duration of 2msec with peak toroidal currents of up to 0.5MA. The plasma-facing components consist of tungsten-coated copper to minimize sputtering. The surfaces are conditioned by a combination of baking at 150 C, glow discharge cleaning, Titanium gettering, and pulse-discharge cleaning with helium plasmas. In this way we can achieve density control so that the plasma density ({approx} 1-4 x 10{sup 20}m{sup -3}) matches the gas input. Low-density operation is presently limited by breakdown requirements, but we hope that new gas valves with supersonic nozzles will allow for a further reduction in density. We find that the conditioning reduces the impurity radiation to the point where it is no longer important to the energy balance, and long-lived spheromak plasmas are obtained (decay times of 1.5msec).

  2. Oxygen fugacity control in piston-cylinder experiments

    NASA Astrophysics Data System (ADS)

    Jakobsson, Sigurdur

    2012-09-01

    The main goal of this study was to develop and test a capsule assembly for use in piston-cylinder experiments where oxygen fugacity could be controlled in the vicinity of the QFM buffer without H2O loss or carbon contamination of the sample material. The assembly consists of an outer Pt-capsule containing a solid buffer (Ni-NiO or Co-CoO) plus H2O and an inner AuPd-capsule, containing the sample, H2O and a Pt-wire. No H2O loss is observed from the sample, even after 48 h, but a slight increase in H2O content is found in longer runs due to oxygen and hydrogen diffusion into the AuPd-capsule. Oxygen fugacity of runs in equilibrium with the Ni-NiO (NNO) and Co-CoO (CoCO) buffers was measured by analyzing Fe dissolved in the Pt-wire and in the AuPd-capsule. The second method gives values that are in good agreement with established buffer values, whereas results from the first method are one half to one log units higher than the established values.

  3. Complete photoionization experiments via ultrafast coherent control with polarization multiplexing.

    PubMed

    Hockett, P; Wollenhaupt, M; Lux, C; Baumert, T

    2014-06-01

    Photoelectron angular distributions (PADs) obtained from ionization of potassium atoms using moderately intense femtosecond IR fields (∼10^{12}  W cm^{-2}) of various polarization states are shown to provide a route to "complete" photoionization experiments. Ionization occurs by a net three-photon absorption process, driven via the 4s→4p resonance at the one-photon level. A theoretical treatment incorporating the intrapulse electronic dynamics allows for a full set of ionization matrix elements to be extracted from 2D imaging data. 3D PADs generated from the extracted matrix elements are also compared to experimental, tomographically reconstructed, 3D photoelectron distributions, providing a sensitive test of their validity. Finally, application of the determined matrix elements to ionization via more complex, polarization-shaped, pulses is demonstrated, illustrating the utility of this methodology towards detailed understanding of complex ionization control schemes and suggesting the utility of such "multiplexed" intrapulse processes as powerful tools for measurement. PMID:24949763

  4. A Controllable Earthquake Rupture Experiment on the Homestake Fault

    NASA Astrophysics Data System (ADS)

    Germanovich, L. N.; Murdoch, L. C.; Garagash, D.; Reches, Z.; Martel, S. J.; Gwaba, D.; Elsworth, D.; Lowell, R. P.; Onstott, T. C.

    2010-12-01

    Fault-slip is typically simulated in the laboratory at the cm-to-dm scale. Laboratory results are then up-scaled by orders of magnitude to understand faulting and earthquakes processes. We suggest an experimental approach to reactivate faults in-situ at scales ~10-100 m using thermal techniques and fluid injection to modify in situ stresses and the fault strength to the point where the rock fails. Mines where the modified in-situ stresses are sufficient to drive faulting, present an opportunity to conduct such experiments. During our recent field work in the former Homestake gold mine in the northern Black Hills, South Dakota, we found a large fault present on multiple mine levels. The fault is subparallel to the local foliation in the Poorman formation, a Proterozoic metamorphic rock deformed into regional-scale folds with axes plunging ~40° to the SSE. The fault extends at least 1.5 km along strike and dip, with a center ~1.5 km deep. It strikes ~320-340° N, dips ~45-70° NE, and is recognized by a ~0.3-0.5 m thick distinct gouge that contains crushed host rock and black material that appears to be graphite. Although we could not find clear evidence for fault displacement, secondary features suggest that it is a normal fault. The size and distinct structure of this fault make it a promising target for in-situ experimentation of fault strength, hydrological properties, and slip nucleation processes. Most earthquakes are thought to be the result of unstable slip on existing faults, Activation of the Homestake fault in response to the controlled fluid injection and thermally changing background stresses is likely to be localized on a crack-like patch. Slow patch propagation, moderated by the injection rate and the rate of change of the background stresses, may become unstable, leading to the nucleation of a small earthquake (dynamic) rupture. This controlled instability is intimately related to the dependence of the fault strength on the slip process and has been

  5. Support and control system of the Waste Isolation Pilot Plant gas generation experiment glovebox

    SciTech Connect

    Benjamin, W.W.; Knight, C.J.; Michelbacher, J.A.; Rosenberg, K.E.

    1997-09-01

    A glovebox was designed and fabricated to house test containers loaded with contact handled transuranic (CH-TRU) waste. The test containers were designed to simulate the environmental characteristics of the caverns at the Waste Isolation Pilot Plant (WIPP). The support and control systems used to operate and maintain the Gas Generation Experiment (GGE) include the following: glovebox atmosphere and pressure control, test container support, glovebox operation support, and gas supply and exhaust systems. The glovebox atmosphere and pressure control systems consist of various components used to control both the pressure and quality of the argon atmosphere inside the glovebox. The glovebox pressure is maintained by three separate pressure control systems. The primary pressure control system is designed to maintain the glovebox at a negative pressure with the other two control systems serving as redundant safety backups. The quality of the argon atmosphere is controlled using a purifying bed system that removes oxygen and moisture. Glovebox atmosphere contaminants that are monitored on a continuous or periodic basis include moisture, oxygen, and nitrogen. The gas generation experiment requires the test containers to be filled with brine, leak tested, maintained at a constant temperature, and the gas head space of the test container sampled on a periodic basis. Test container support systems consisting of a brine addition system, leak test system, heating system, and gas sampling system were designed and implemented. A rupture disk system was constructed to provide pressure relief to the test containers. Operational requirements stipulated that test container temperature and pressure be monitored and collected on a continuous basis. A data acquisition system (DAS) was specifically designed to meet these requirements.

  6. The Deep Impact Network Experiment Operations Center Monitor and Control System

    NASA Technical Reports Server (NTRS)

    Wang, Shin-Ywan (Cindy); Torgerson, J. Leigh; Schoolcraft, Joshua; Brenman, Yan

    2009-01-01

    The Interplanetary Overlay Network (ION) software at JPL is an implementation of Delay/Disruption Tolerant Networking (DTN) which has been proposed as an interplanetary protocol to support space communication. The JPL Deep Impact Network (DINET) is a technology development experiment intended to increase the technical readiness of the JPL implemented ION suite. The DINET Experiment Operations Center (EOC) developed by JPL's Protocol Technology Lab (PTL) was critical in accomplishing the experiment. EOC, containing all end nodes of simulated spaces and one administrative node, exercised publish and subscribe functions for payload data among all end nodes to verify the effectiveness of data exchange over ION protocol stacks. A Monitor and Control System was created and installed on the administrative node as a multi-tiered internet-based Web application to support the Deep Impact Network Experiment by allowing monitoring and analysis of the data delivery and statistics from ION. This Monitor and Control System includes the capability of receiving protocol status messages, classifying and storing status messages into a database from the ION simulation network, and providing web interfaces for viewing the live results in addition to interactive database queries.

  7. Adaptation of the pore diffusion model to describe multi-addition batch uptake high-throughput screening experiments.

    PubMed

    Traylor, Steven J; Xu, Xuankuo; Li, Yi; Jin, Mi; Li, Zheng Jian

    2014-11-14

    Equilibrium isotherm and kinetic mass transfer measurements are critical to mechanistic modeling of binding and elution behavior within a chromatographic column. However, traditional methods of measuring these parameters are impractically time- and labor-intensive. While advances in high-throughput robotic liquid handling systems have created time and labor-saving methods of performing kinetic and equilibrium measurements of proteins on chromatographic resins in a 96-well plate format, these techniques continue to be limited by physical constraints on protein addition, incubation and separation times; the available concentration of protein stocks and process pools; and practical constraints on resin and fluid volumes in the 96-well format. In this study, a novel technique for measuring protein uptake kinetics (multi-addition batch uptake) has been developed to address some of these limitations during high-throughput batch uptake kinetic measurements. This technique uses sequential additions of protein stock to chromatographic resin in a 96-well plate and the subsequent removal of each addition by centrifugation or vacuum separation. The pore diffusion model was adapted here to model multi-addition batch uptake and was tested and compared with traditional batch uptake measurements of uptake of an Fc-fusion protein on an anion exchange resin. Acceptable agreement between the two techniques is achieved for the two solution conditions investigated here. In addition, a sensitivity analysis of the model to the physical inputs is presented and the advantages and limitations of the multi-addition batch uptake technique are explored. PMID:25311484

  8. Addition of trim coils to the Tandem Mirror Experiment Upgrade (TMX-U) magnet system to improve the magnetic field mapping

    SciTech Connect

    Wong, R.L.; Pedrotti, L.R.; Baldwin, D.E.; Hibbs, S.M.; Hill, D.N.; Hornady, R.H.; Jackson, M.C.

    1985-11-14

    The mapping of the magnetic flux bundle from the center cell to the Plasma Potential Control plates (PPC) on the end fan of the Tandem Mirror Experiment Upgrade (TMX-U), was improved by the addition of trim coils (12,000 amp-turns) on each side of each end fan next to the pump beam magnetic shields. The coils' axes are oriented perpendicular to the machine centerline. These coils made the necessary corrections to the field-line mapping, while keeping the field in the nearby pump beam magnetic shield below the saturation threshold. This paper briefly describes the problem, discusses the design as it evolved, and presents the results of the field testing. The disturbance to the field mapping and the appropriate corrections were determined using the code GFUN (a three dimensional electromagnetic field analysis code that includes the presence of permeable materials). The racetrack-shaped coils have dimensions of 1.5 feet by 3 feet and are powered by a renovated 600 kW Bart-Messing power supply controlled by the machine's magnet control system. The magnets were fabricated from polyimide-coated magnet wire. They are rated to 200/sup 0/C, although in pulsed operation they rise only a few degrees centigrade. The coils are placed outside of the vacuum system, and thus are considerably simpler than the other machine magnets. The restraints are designed to withstand a force of 1000 pounds per coil and a turning moment of 1000 foot pounds. The calculated field strengths were verified on the machine by inserting a Hall probe along the axis. The perturbations to the neutral beam magnetic shields were also measured. A brief description of the improvement in the machine performance is also included.

  9. Volcanic Monitoring Techniques Applied to Controlled Fragmentation Experiments

    NASA Astrophysics Data System (ADS)

    Kueppers, U.; Alatorre-Ibarguengoitia, M. A.; Hort, M. K.; Kremers, S.; Meier, K.; Scharff, L.; Scheu, B.; Taddeucci, J.; Dingwell, D. B.

    2010-12-01

    Volcanic eruptions are an inevitable natural threat. The range of eruptive styles is large and short term fluctuations of explosivity or vent position pose a large risk that is not necessarily confined to the immediate vicinity of a volcano. Explosive eruptions rather may also affect aviation, infrastructure and climate, regionally as well as globally. Multiparameter monitoring networks are deployed on many active volcanoes to record signs of magmatic processes and help elucidate the secrets of volcanic phenomena. However, our mechanistic understanding of many processes hiding in recorded signals is still poor. As a direct consequence, a solid interpretation of the state of a volcano is still a challenge. In an attempt to bridge this gap, we combined volcanic monitoring and experimental volcanology. We performed 15 well-monitored, field-based, experiments and fragmented natural rock samples from Colima volcano (Mexico) by rapid decompression. We used cylindrical samples of 60 mm height and 25 mm and 60 mm diameter, respectively, and 25 and 35 vol.% open porosity. The applied pressure range was from 4 to 18 MPa. Using different experimental set-ups, the pressurised volume above the samples ranged from 60 - 170 cm3. The experiments were performed at ambient conditions and at controlled sample porosity and size, confinement geometry, and applied pressure. The experiments have been thoroughly monitored with 1) Doppler Radar (DR), 2) high-speed and high-definition cameras, 3) acoustic and infrasound sensors, 4) pressure transducers, and 5) electrically conducting wires. Our aim was to check for common results achieved by the different approaches and, if so, calibrate state-of-the-art monitoring tools. We present how the velocity of the ejected pyroclasts was measured by and evaluated for the different approaches and how it was affected by the experimental conditions and sample characteristics. We show that all deployed instruments successfully measured the pyroclast

  10. Classical oscillators in the control of quantum tunneling: Numerical experiments

    NASA Astrophysics Data System (ADS)

    Kar, Susmita; Bhattacharyya, S. P.

    2016-06-01

    The dynamics of a classical anharmonic oscillator is exploited to control the tunneling dynamics of a quantum particle to which the classical oscillator is coupled. The mixed quantum classical problem is investigated at a mean-field like level. The anharmonic strength (λ) , particle mass (Mc) and harmonic stiffness (ωc) of the classical controller are explored as possible control parameters for the tunneling dynamics. The strength, the type of coupling between the quantum system and classical controller and the effective frequency of the controller emerge as crucial factors in shaping the nature and extent of the control. A whole spectrum of possibilities starting from enhancement, suppression to complete destruction of tunneling emerge depending on values assigned to the control parameters, the type of coupling and the control configuration used. When classical controller is replaced by a quantum controller, the control landscape becomes much simpler.

  11. The dynamics and control of the orbiting spacecraft control laboratory experiment (SCOLE) during station keeping

    NASA Technical Reports Server (NTRS)

    Bainum, Peter M.; Diarra, Cheick M.

    1988-01-01

    A mathematical model is developed to predict the dynamics of the proposed orbiting Spacecraft Control Laboratory Experiment during the station keeping phase. The Shuttle as well as the reflector are assumed to be rigid, the mast is flexible and is assumed to undergo elastic displacements very small as compared with its length. The equations of motion are derived using a Newton-Euler formulation. The model includes the effects of gravity, flexibility, and orbital dynamics. The control is assumed to be provided to the system through the Shuttle's three torquers, and through six actuators located by pairs at two points on the mast and at the mass center of the reflector. At each of the locations, an actuator acts parallel to the roll axis while the other one acts parallel to the pitch axis. It is seen that, in the presence of gravity-gradient torques in the system dynamics, the system assumes a new equilibrium position about which the equations must be linearized, primarily due to the offset in the mast attachment point to the reflector. The linear regulator theory is used to derive control laws for the linear model of the SCOLE including the first four flexible modes. Numerical results confirm the robustness of this control strategy for station keeping with maximum control efforts significantly below saturation levels.

  12. Heat treatment and the use of additives to improve the stability of paralytic shellfish poisoning toxins in shellfish tissue reference materials for internal quality control and proficiency testing.

    PubMed

    Burrell, Stephen; Clion, Valentin; Auroy, Virginie; Foley, Barry; Turner, Andrew D

    2015-06-01

    The need for homogenous reference materials stable for paralytic shellfish toxins is vital for the monitoring and quality assurance of these potent neurotoxins in shellfish. Two stabilisation techniques were investigated, heat treatment through autoclaving and the addition of preserving additives into the tissue matrix. Short and long-term stability experiments as well as homogeneity determination were conducted on materials prepared by both techniques in comparison with an untreated control using two LC-FLD methods. Both techniques improved the stability of the matrix and the PSP toxins present compared to the controls. A material was prepared using the combined techniques of heat treatment followed by spiking with additives and data is presented from this optimised reference material as used over a two year period in the Irish national monitoring program and in a development exercise as part of a proficiency testing scheme operated by QUASIMEME (Quality Assurance of Information for Marine Environmental Monitoring in Europe) since 2011. The results were indicative of the long-term stability of the material as evidenced through consistent assigned values in the case of the proficiency testing scheme and a low relative standard deviation of 10.5% for total toxicity data generated over 24 months. PMID:25816999

  13. An Additional Approach to Model Current Followers and Amplifiers with Electronically Controllable Parameters from Commercially Available ICs

    NASA Astrophysics Data System (ADS)

    Sotner, R.; Kartci, A.; Jerabek, J.; Herencsar, N.; Dostal, T.; Vrba, K.

    2012-12-01

    Several behavioral models of current active elements for experimental purposes are introduced in this paper. These models are based on commercially available devices. They are suitable for experimental tests of current- and mixed-mode filters, oscillators, and other circuits (employing current-mode active elements) frequently used in analog signal processing without necessity of onchip fabrication of proper active element. Several methods of electronic control of intrinsic resistance in the proposed behavioral models are discussed. All predictions and theoretical assumptions are supported by simulations and experiments. This contribution helps to find a cheaper and more effective way to preliminary laboratory tests without expensive on-chip fabrication of special active elements.

  14. Impact of solvent additive on exciton dissociation in P3HT : EP-PDI blend film via controlling morphology

    NASA Astrophysics Data System (ADS)

    Yang, Xiao-Yu; Xu, Wei-Long; Zheng, Fei; Liu, Jian-Qiang; Hao, Xiao-Tao

    2016-06-01

    Suitable solvent additives provide an effective means to control the morphology of polymer blend films. In this work, we systematically investigate the impact of the solvent additive chloronaphthalene (CN) on the morphology of P3HT : EP-PDI blends. The optimum volume fraction of solvent additive CN was found to be 0.5 vol% by atom force microscopy and transmission electron microscopy. UV–visible absorption spectroscopy and grazing incidence x-ray diffraction indicate that the crystallinity of both the P3HT and EP-PDI domains significantly decreased in the blends with 0.5 vol% CN. Grazing incidence small-angle x-ray scattering results show that the size of the small EP-PDI aggregation decreases from 44–22 nm with the addition of CN. Time-resolved photoluminescence measurement reveals that the decreased EP-PDI domains give rise to increased donor–acceptor interfacial areas, which not only facilitate the exciton dissociation, but suppresses the formation of the EP-PDI intermolecular state.

  15. The White Pine Mine explosively induced, controlled collapse experiment

    SciTech Connect

    Pearson, D.C.; Stump, B.W.; Phillips, W.S.

    1996-09-01

    On September 3, 1995, the White Pine Mine, which is owned by Copper Range Company, conducted the first of a planned series of explosive removal of existing pillars in their underground mining operations. The purpose of this operation is to evaluate the effectiveness of pillar rubbilization and roof collapse for planned in-situ leaching of the copper ore from the rock mass. This type of seismic source is unique in that a large, delay fired, explosive source was expected to be followed by collapse of the rock immediately above the explosion into the void created. Characterization of this type of mining source is of interest to the Comprehensive Test Ban Treaty (CTBT) R&D Seismic Program due to its unique properties. These include the controlled nature of the source in time, location, and magnitude, the fact that the source is located in an active region of underground mining, and that natural collapse of large portions of this mine have occurred in the recent past. The Mine operator is concerned with the characterization of the vibration induced by both the explosive and implosive components of the procedure and determination of the depth to which chimneying of the roof proceeded. This report will document: The reasons for conducting both the explosively induced collapse and the Los Alamos National Laboratory CTBT R&D Experimental Field Program experiment; The local and regional seismic, acoustic, and videographic data acquired; Analysis of the explosion/collapse seismic signal generated; Analysis and location of the aftershocks associated with the collapse; and Conclusions made concerning this type of mining explosion in relation to verification of a Comprehensive Test Ban Treaty.

  16. Stability of ZnO quantum dots tuned by controlled addition of ethylene glycol during their growth

    NASA Astrophysics Data System (ADS)

    Zimmermann, Lizandra M.; Baldissera, Paulo V.; Bechtold, Ivan H.

    2016-07-01

    ZnO quantum dots were prepared via a sol–gel route from zinc acetate and sodium hydroxide. The influence of ethylene glycol addition during the first stages of reaction (1–5 min) as a stabilizer, as well as the influence of its concentration in 2-propanol were investigated. The optimization led to particles with enough stability and homogeneity around 3.7 nm of diameter to allow for quantum confinement effect. Spectroscopic UV–vis absorption measurements allowed to explore the underlying mechanism of nucleation and growth and to have the control of it. The emission of the ZnO nanoparticles was explored under experimental perturbations with addition of small amounts of water to investigate the interplay between surface defects and the excitonic effect. The results suggest that the water interferes directly on the defects first and later on the excitonic recombination. Their morphology was determined with transmission electron microscopy.

  17. The influence of deposit control additives on nitrogen oxides emissions from spark ignition engines (case study: Tehran).

    PubMed

    Bidhendi, Gholamreza Nabi; Zand, Ali Daryabeigi; Tabrizi, Alireza Mikaeili; Pezeshk, Hamid; Baghvand, Akbar

    2007-04-15

    In the present research, the influence of a deposit control additive on NOx emissions from two types of gasoline engine vehicles i.e., Peykan (base on Hillman) and Pride (South Korea Kia motors) was studied. Exhaust NOx emissions were measured in to stages, before decarbonization process and after that. Statistical analysis was conducted on the measurement results. Results showed that NOx emissions from Peykans increased 0.28% and NOx emissions from Pride automobiles decreased 6.18% on average, due to the elimination of engine deposits. The observed variations were not statistically and practically significant. The results indicated that making use of detergent additives is not an effective way to reduce the exhaust NOx emissions from gasoline engine vehicles. PMID:19069943

  18. Preliminary structural control results from the Middeck Active Control Experiment (MACE)

    NASA Technical Reports Server (NTRS)

    Miller, David W.; Saarmaa, Erik; Jacques, Robert N.

    1992-01-01

    Results are presented of on-going closed-loop ground experiments on the MACE test article, the objective of which is to investigate the extent to which closed-loop behavior of flexible spacecraft in zero gravity can be predicted, as well as to examine orbit system identification and control reconfiguration. The MACE hardware consists of three torque wheels, a two-axis gimballing payload, inertial sensors, and a flexible support structure. With the acquisition of a second payload, this is to represent a multiple payload platform with significant structural flexibility. When linear quadratic Gaussian control is used, payload pointing accuracy is improved by an order of magnitude when disturbed by a broadband torque disturbance. The successes and failures of the design and implementation process are discussed.

  19. Structural control sensors for CASES. [Control, Astrophysics and Structures Experiment in Space

    NASA Technical Reports Server (NTRS)

    Davis, Hugh W.; Sharkey, John P.; Carrington, Connie K.

    1990-01-01

    The Remote Attitude Measurement Sensor (RAMS) is currently baselined to meet two important sensor needs for CASES (Control, Astrophysics and Structures Experiment in Space). First, as a tip displacement sensor, RAMS is designed to provide accurate knowledge of the position and orientation of the boom tip assembly. Secondly, as a boom motion tracker, it is designed to monitor 43 reflective targets which are distributed along the length of the boom and provide displacment information for post facto processing. The design and operation of RAMS as these two types of sesnors are described, and attention is given to how RAMS interfaces with the CASES closed-loop control system and how systems identification is accommodated.

  20. Effect of kaolin addition on the performance of controlled low-strength material using industrial waste incineration bottom ash.

    PubMed

    Naganathan, Sivakumar; Razak, Hashim Abdul; Hamid, Siti Nadzriah Abdul

    2010-09-01

    Incineration of industrial waste produces large quantities of bottom ash which are normally sent to secured landfill, but is not a sustainable solution. Use of bottom ash in engineering applications will contribute to sustainability and generate revenue. One way of using the industrial waste incineration bottom ash is in controlled low-strength material (CLSM). Use of bottom ash in CLSM has problems related to bleeding and excessive strength development and so an additive has to be used to control bleeding and strength development. The main objective of this research is to study the effect of kaolin addition on the performance of CLSM made using industrial waste incineration bottom ash. CLSM mixes were made with bottom ash, cement, and refined kaolin. Various tests were performed on the CLSM in fresh and hardened states including compressive strength, water absorption, California bearing ratio (CBR) and the tests for concentration of leachable substances on the bleed and leachate. The compressive strength of CLSM tested ranged from 0.11 to 9.86 MPa. CBR values ranged from 6 to 46, and water absorption values from 12 to 36%. It was shown that the addition of kaolin delayed the initial setting time of CLSM mixtures, reduced bleeding, lowered the compressive strength, and increased the values of water absorption, sorption, and initial surface absorption. The CLSM tested did not have corrosivity. It was shown that the hardened CLSM was non hazardous, and the addition of kaolin increased the concentration of heavy metals and salts in the bleed and leachate. PMID:20852000

  1. Reflections on Doctoral Supervision: Drawing from the Experiences of Students with Additional Learning Needs in Two Universities

    ERIC Educational Resources Information Center

    Collins, Bethan

    2015-01-01

    Supervision is an essential part of doctoral study, consisting of relationship and process aspects, underpinned by a range of values. To date there has been limited research specifically about disabled doctoral students' experiences of supervision. This paper draws on qualitative, narrative interviews about doctoral supervision with disabled…

  2. Examining the Influence of Additional Field-Based Experiences on Pre-Service Teachers and Their Perceived Ability to Teach

    ERIC Educational Resources Information Center

    Clark, Sarah K.

    2012-01-01

    In an attempt to analyse more closely the training experiences of pre-service teachers, the author conducted an exploratory quasi-experimental study at a university located in the Rocky Mountain region of the USA. All students who were enrolled in the same reading methods course (but enrolled in different sections) were invited to participate in…

  3. Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized using polyol method

    NASA Astrophysics Data System (ADS)

    Junaidi, Yunus, Muhammad; Triyana, Kuwat; Harsojo, Suharyadi, Edi

    2016-04-01

    We report our investigation on the effect of chloride ions on controlling the shapes and properties of silver nanorods (AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as a salt precursor and performed at the oil bath temperature of 140°C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorods were characterized using SEM and XRD. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline of silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorods decreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

  4. International Co-Operation in Control Engineering Education Using Online Experiments

    ERIC Educational Resources Information Center

    Henry, Jim; Schaedel, Herbert M.

    2005-01-01

    This paper describes the international co-operation experience in teaching control engineering with laboratories being conducted remotely by students via the Internet. This paper describes how the students ran the experiments and their personal experiences with the laboratory. A tool for process identification and controller tuning based on…

  5. Control and Stabilization: Making Millikan's Oil Drop Experiment Work

    ERIC Educational Resources Information Center

    Muller-Hill, Christoph; Heering, Peter

    2011-01-01

    Educational versions of Millikan's oil-drop experiment have frequently been criticized; suggestions for improvement either focus on technical innovations of the setup or on replacing the experiment by other approaches of familiarization, such as computer simulations. In our approach, we have analysed experimental procedures. In doing so, we were…

  6. Feelings of Control: Contingency Determines Experience of Action

    ERIC Educational Resources Information Center

    Moore, James W.; Lagnado, David; Deal, Darvany C.; Haggard, Patrick

    2009-01-01

    The experience of causation is a pervasive product of the human mind. Moreover, the experience of causing an event alters subjective time: actions are perceived as temporally shifted towards their effects [Haggard, P., Clark, S., & Kalogeras, J. (2002). Voluntary action and conscious awareness. "Nature Neuroscience," 5(4), 382-385]. This temporal…

  7. Adaptive-Control Experiments On A Large Flexible Structure

    NASA Technical Reports Server (NTRS)

    Ih, Che-Hang C.; Bayard, David S.; Wang, Shyh J.; Eldred, Daniel B.

    1990-01-01

    Antennalike flexible structure built for research in advanced technology including suppression of vibrations and control of initial deflections. Structure instrumented with sensors and actuators connected to digital electronic control system, programmed with control algorithms to be tested. Particular attention in this research focused on direct model-reference adaptive-control algorithm based on command generator tracker theory. Built to exhibit multiple vibrational modes, low modal frequencies, and low structural damping. Made three-dimensional so complicated interactions among components of structure and control system investigated.

  8. Maintaining and improving the control and safety systems for the Electromagnetic Calorimeter of the CMS experiment

    NASA Astrophysics Data System (ADS)

    Di Calafiori, D.; Adzic, P.; Dissertori, G.; Holme, O.; Jovanovic, D.; Lustermann, W.; Zelepoukine, S.

    2012-12-01

    This paper presents the current architecture of the control and safety systems designed and implemented for the Electromagnetic Calorimeter (ECAL) of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). An evaluation of system performance during all CMS physics data taking periods is reported, with emphasis on how software and hardware solutions are used to overcome limitations, whilst maintaining and improving reliability and robustness. The outcomes of the CMS ECAL Detector Control System (DCS) Software Analysis Project were a fundamental step towards the integration of all control system applications and the consequent piece-by-piece software improvements allowed a smooth transition to the latest revision of the system. The ongoing task of keeping the system in-line with new hardware technologies and software platforms specified by the CMS DCS Group is discussed. The structure of the comprehensive support service with detailed incident logging is presented in addition to a complete test setup for reproducing failures and for testing solutions prior to deployment into production. A correlation between the acquired experience, the development of new software tools and a reduction in the DCS support load is highlighted.

  9. Adaptive independent joint control of manipulators - Theory and experiment

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1988-01-01

    The author presents a simple decentralized adaptive control scheme for multijoint robot manipulators based on the independent joint control concept. The proposed control scheme for each joint consists of a PID (proportional integral and differential) feedback controller and a position-velocity-acceleration feedforward controller, both with adjustable gains. The static and dynamic couplings that exist between the joint motions are compensated by the adaptive independent joint controllers while ensuring trajectory tracking. The proposed scheme is implemented on a MicroVAX II computer for motion control of the first three joints of a PUMA 560 arm. Experimental results are presented to demonstrate that trajectory tracking is achieved despite strongly coupled, highly nonlinear joint dynamics. The results confirm that the proposed decentralized adaptive control of manipulators is feasible, in spite of strong interactions between joint motions. The control scheme presented is computationally very fast and is amenable to parallel processing implementation within a distributed computing architecture, where each joint is controlled independently by a simple algorithm on a dedicated microprocessor.

  10. Shuttle Payload Ground Command and Control: An Experiment Implementation Combustion Module-2 Software Development, STS-107

    NASA Technical Reports Server (NTRS)

    Carek, David Andrew

    2003-01-01

    This presentation covers the design of a command and control architecture developed by the author for the Combustion Module-2 microgravity experiment, which flew aboard the STS-107 Shuttle mission, The design was implemented to satisfy a hybrid network that utilized TCP/IP for both the onboard segment and ground segment, with an intermediary unreliable transport for the space to ground segment. With the infusion of Internet networking technologies into Space Shuttle, Space Station, and spacecraft avionics systems, comes the need for robust methodologies for ground command and control. Considerations of high bit error links, and unreliable transport over intermittent links must be considered in such systems. Internet protocols applied to these systems, coupled with the appropriate application layer protections, can provide adequate communication architectures for command and control. However, there are inherent limitations and additional complexities added by the use of Internet protocols that must be considered during the design. This presentation will discuss the rationale for the: framework and protocol algorithms developed by the author. A summary of design considerations, implantation issues, and learned lessons will be will be presented. A summary of mission results using this communications architecture will be presented. Additionally, areas of further needed investigation will be identified.

  11. Structural control research and experiments at NASA/LaRC

    NASA Technical Reports Server (NTRS)

    Montgomery, R. C.

    1983-01-01

    Research progress in the area of structural dynamics and control using the flexible beam facility at the NASA Langley Research Center is reviewed. Particular attention is placed on the progress in adaptive control and reliability improvements using advanced control concepts. Both theoretical and experimental results are given to indicate the nature of the work being undertaken. In the adaptive control area, emphasis is placed on parameter and system identification and in comparison of competing on-line algorithms. Also, results are presented for on-line modal control laws that are interfaced to a parameter identification scheme. This provides an on-line distributed adaptive control system. In the reliability area, a design process is outlined that incorporates reliability over the design mission life.

  12. Experiments in identification and control of flexible-link manipulators

    NASA Technical Reports Server (NTRS)

    Yurkovich, Stephen; Tzes, Anthony P.

    1990-01-01

    A report is presented on an ongoing effort for end-point position control of flexible-link manipulators under realistic conditions in laboratory setups consisting of one- and two-link manipulators. The authors treat modeling, identification, and control of flexible-link manipulators that are required to carry payloads, possibly unknown and varying, while undergoing disturbance effects from the environments and the workspace. The various identification and control techniques being investigated are summarized, with emphasis on the ability of the controller to adjust to changes in dynamics, payload, and working environment. It is found that time-domain methods offer identified model structures that are readily available for control design, whereas frequency-domain methods, particularly the time-varying transfer function estimation approach developed for this application, are more desirable when rapid controller tuning is required.

  13. Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized by polyol method

    NASA Astrophysics Data System (ADS)

    Junaidi, Triyana, Kuwat; Harsojo, Suharyadi, Edi

    2016-04-01

    We report our investigation on the effect of chloride ions oncontrolling the shapes and properties of silver nanorods(AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as asalt precursor and performed at the oilbath temperature of 140 °C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorodswere characterized using UV-VIS, XRD, SEM and TEM. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorodsdecreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

  14. The addition of upper cervical manipulative therapy in the treatment of patients with fibromyalgia: a randomized controlled trial.

    PubMed

    Moustafa, Ibrahim M; Diab, Aliaa A

    2015-07-01

    The aim of this study was to investigate the immediate and long-term effects of a one-year multimodal program, with the addition of upper cervical manipulative therapy, on fibromyalgia management outcomes in addition to three-dimensional (3D) postural measures. This randomized clinical trial with one-year follow-up was completed at the research laboratory of our university. A total of 120 (52 female) patients with fibromyalgia syndrome (FMS) and definite C1-2 joint dysfunction were randomly assigned to the control or an experimental group. Both groups received a multimodal program; additionally, the experimental group received upper cervical manipulative therapy. Primary outcomes were the Fibromyalgia Impact Questionnaire (FIQ), whereas secondary outcomes included Pain Catastrophizing Scale (PCS), algometric score, Pittsburgh Sleep Quality Index (PSQI), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), and 3D postural measures. Measures were assessed at three time intervals: baseline, 12 weeks, and 1 year after the 12-week follow-up. The general linear model with repeated measures indicated a significant group × time effect in favor of the experimental group on the measures of 3D postural parameters (P < .0005), FIQ (P < .0005), PCS (P < .0005), algometric score (F = P < .0005), PSQI (P < .0005), BAI (P < .0005), and BDI (P < .0005). The addition of the upper cervical manipulative therapy to a multimodal program is beneficial in treating patients with FMS. PMID:25782585

  15. Active control of space structures: Proof of concept experiment

    NASA Technical Reports Server (NTRS)

    Breakwell, J. A.

    1982-01-01

    Modern control theory easily works with multiple input/multiple output systems. Two types of systems which fall into this category are flexible systems, where many measurements and several actuators are necessary to provide control over bending behavior, and articulated systems which consist of several rigid bodies connected together by pivoting connections. In this latter case, multiple controls are implemented as torquers at the joints.

  16. Active control of space structures: Proof of concept experiment

    NASA Astrophysics Data System (ADS)

    Breakwell, J. A.

    1982-03-01

    Modern control theory easily works with multiple input/multiple output systems. Two types of systems which fall into this category are flexible systems, where many measurements and several actuators are necessary to provide control over bending behavior, and articulated systems which consist of several rigid bodies connected together by pivoting connections. In this latter case, multiple controls are implemented as torquers at the joints.

  17. Expert system to control a fusion energy experiment

    SciTech Connect

    Johnson, R.R.; Canales, T.; Lager, D.

    1986-01-01

    This paper describes a system that automates neutral beam source conditioning. The system achieves this with artificial intelligence techniques by encoding the behavior of several experts as a set of if-then rules in an expert system. One of the functions of the expert system is to control an adaptive controller that, in turn, controls the neutral beam source. The architecture of the system is presented followed by a description of its performance.

  18. Flight experience with manually controlled unconventional aircraft motions

    NASA Technical Reports Server (NTRS)

    Barfield, A. F.

    1978-01-01

    A modified YF-16 aircraft was used to flight demonstrate decoupled modes under the USAF Fighter Control Configured Vehicle (CCV) Program. The direct force capabilities were used to implement seven manually controlled unconventional modes on the aircraft, allowing flat turns, decoupled normal acceleration control, independent longitudinal and lateral translations, uncoupled elevation and azimuth aiming, and blended direct lift. This paper describes the design, development, and flight testing of these control modes. The need for task-tailored mode authorities, gain-scheduling and selected closed-loop design is discussed.

  19. Some experiences with active control of aeroelastic response

    NASA Technical Reports Server (NTRS)

    Newsom, J. R.; Abel, I.

    1981-01-01

    Flight and wind tunnel tests were conducted and multidiscipline computer programs were developed as part of investigations of active control technology conducted at the NASA Langley Research Center. Unsteady aerodynamics approximation, optimal control theory, optimal controller design, and the Delta wing and DC-10 models are described. The drones for aerodynamics and structural testing (DAST program) for evaluating procedures for aerodynamic loads prediction and the design of active control systems on wings with significant aeroelastic effects is described as well as the DAST model used in the wind tunnel tests.

  20. Out-reach in-space technology experiments program: Control of flexible robot manipulators in zero gravity, experiment definition phase

    NASA Technical Reports Server (NTRS)

    Phillips, Warren F.

    1989-01-01

    The results obtained show that it is possible to control light-weight robots with flexible links in a manner that produces good response time and does not induce unacceptable link vibrations. However, deflections induced by gravity cause large static position errors with such a control system. For this reason, it is not possible to use this control system for controlling motion in the direction of gravity. The control system does, on the other hand, have potential for use in space. However, in-space experiments will be needed to verify its applicability to robots moving in three dimensions.

  1. AFECS. multi-agent framework for experiment control systems

    NASA Astrophysics Data System (ADS)

    Gyurjyan, V.; Abbott, D.; Heyes, G.; Jastrzembski, E.; Timmer, C.; Wolin, E.

    2008-07-01

    AFECS is a pure Java based software framework for designing and implementing distributed control systems. AFECS creates a control system environment as a collection of software agents behaving as finite state machines. These agents can represent real entities, such as hardware devices, software tasks, or control subsystems. A special control oriented ontology language (COOL), based on RDFS (Resource Definition Framework Schema) is provided for control system description as well as for agent communication. AFECS agents can be distributed over a variety of platforms. Agents communicate with their associated physical components using range of communication protocols, including tcl-DP, cMsg (publish-subscribe communication system developed at Jefferson Lab), SNMP (simple network management protocol), EPICS channel access protocol and JDBC.

  2. AFECS. Multi-Agent Framework for Experiment Control Systems

    SciTech Connect

    Vardan Gyurjyan; David Abbott; William Heyes; Edward Jastrzembski; Carl Timmer; Elliott Wolin

    2008-01-23

    AFECS is a pure Java based software framework for designing and implementing distributed control systems. AFECS creates a control system environment as a collection of software agents behaving as finite state machines. These agents can represent real entities, such as hardware devices, software tasks, or control subsystems. A special control oriented ontology language (COOL), based on RDFS (Resource Definition Framework Schema) is provided for control system description as well as for agent communication. AFECS agents can be distributed over a variety of platforms. Agents communicate with their associated physical components using range of communication protocols, including tcl-DP, cMsg (publish-subscribe communication system developed at Jefferson Lab), SNMP (simple network management protocol), EPICS channel access protocol and JDBC.

  3. A mathematical problem and a Spacecraft Control Laboratory Experiment (SCOLE) used to evaluate control laws for flexible spacecraft. NASA/IEEE design challenge

    NASA Technical Reports Server (NTRS)

    Taylor, Lawrence W., Jr.; Balakrishnan, A. V.

    1988-01-01

    The problen of controlling large, flexible space systems has been evaluated using computer simulation. In several cases, ground experiments have also been used to validate system performance under more realistic conditions. There remains a need, however, to test additional control laws for flexible spacecraft and to directly compare competing design techniques. A program is discussed which has been initiated to make direct comparisons of control laws for, first, a mathematical problem, then and experimental test article being assembled under the cognizance of the Spacecraft Control Branch at the NASA Langley Research Center with the advice and counsel of the IEEE Subcommittee on Large Space Structures. The physical apparatus will consist of a softly supported dynamic model of an antenna attached to the Shuttle by a flexible beam. The control objective will include the task of directing the line-of-sight of the Shuttle antenna configuration toward a fixed target, under conditions of noisy data, control authority and random disturbances.

  4. Randomised Controlled Feasibility Trial of an Evidence-Informed Behavioural Intervention for Obese Adults with Additional Risk Factors

    PubMed Central

    Sniehotta, Falko F.; Dombrowski, Stephan U.; Avenell, Alison; Johnston, Marie; McDonald, Suzanne; Murchie, Peter; Ramsay, Craig R.; Robertson, Kim; Araujo-Soares, Vera

    2011-01-01

    Background Interventions for dietary and physical activity changes in obese adults may be less effective for participants with additional obesity-related risk factors and co-morbidities than for otherwise healthy individuals. This study aimed to test the feasibility and acceptability of the recruitment, allocation, measurement, retention and intervention procedures of a randomised controlled trial of an intervention to improve physical activity and dietary practices amongst obese adults with additional obesity related risk factors. Method Pilot single centre open-labelled outcome assessor-blinded randomised controlled trial of obese (Body Mass Index (BMI)≥30 kg/m2) adults (age≥18 y) with obesity related co-morbidities such as type 2 diabetes, impaired glucose tolerance or hypertension. Participants were randomly allocated to a manual-based group intervention or a leaflet control condition in accordance to a 2∶1 allocation ratio. Primary outcome was acceptability and feasibility of trial procedures, secondary outcomes included measures of body composition, physical activity, food intake and psychological process measures. Results Out of 806 potentially eligible individuals identified through list searches in two primary care general medical practices N = 81 participants (63% female; mean-age = 56.56(11.44); mean-BMI = 36.73(6.06)) with 2.35(1.47) co-morbidities were randomised. Scottish Index of Multiple Deprivation (SIMD) was the only significant predictor of providing consent to take part in the study (higher chances of consent for invitees with lower levels of deprivation). Participant flowcharts, qualitative and quantitative feedback suggested good acceptance and feasibility of intervention procedures but 34.6% of randomised participants were lost to follow-up due to overly high measurement burden and sub-optimal retention procedures. Participants in the intervention group showed positive trends for most psychological, behavioural and body

  5. Stochastic sampled-data control for synchronization of complex dynamical networks with control packet loss and additive time-varying delays.

    PubMed

    Rakkiyappan, R; Sakthivel, N; Cao, Jinde

    2015-06-01

    This study examines the exponential synchronization of complex dynamical networks with control packet loss and additive time-varying delays. Additionally, sampled-data controller with time-varying sampling period is considered and is assumed to switch between m different values in a random way with given probability. Then, a novel Lyapunov-Krasovskii functional (LKF) with triple integral terms is constructed and by using Jensen's inequality and reciprocally convex approach, sufficient conditions under which the dynamical network is exponentially mean-square stable are derived. When applying Jensen's inequality to partition double integral terms in the derivation of linear matrix inequality (LMI) conditions, a new kind of linear combination of positive functions weighted by the inverses of squared convex parameters appears. In order to handle such a combination, an effective method is introduced by extending the lower bound lemma. To design the sampled-data controller, the synchronization error system is represented as a switched system. Based on the derived LMI conditions and average dwell-time method, sufficient conditions for the synchronization of switched error system are derived in terms of LMIs. Finally, numerical example is employed to show the effectiveness of the proposed methods. PMID:25797504

  6. Stratospheric controlled perturbation experiment: a small-scale experiment to improve understanding of the risks of solar geoengineering

    PubMed Central

    Dykema, John A.; Keith, David W.; Anderson, James G.; Weisenstein, Debra

    2014-01-01

    Although solar radiation management (SRM) through stratospheric aerosol methods has the potential to mitigate impacts of climate change, our current knowledge of stratospheric processes suggests that these methods may entail significant risks. In addition to the risks associated with current knowledge, the possibility of ‘unknown unknowns’ exists that could significantly alter the risk assessment relative to our current understanding. While laboratory experimentation can improve the current state of knowledge and atmospheric models can assess large-scale climate response, they cannot capture possible unknown chemistry or represent the full range of interactive atmospheric chemical physics. Small-scale, in situ experimentation under well-regulated circumstances can begin to remove some of these uncertainties. This experiment—provisionally titled the stratospheric controlled perturbation experiment—is under development and will only proceed with transparent and predominantly governmental funding and independent risk assessment. We describe the scientific and technical foundation for performing, under external oversight, small-scale experiments to quantify the risks posed by SRM to activation of halogen species and subsequent erosion of stratospheric ozone. The paper's scope includes selection of the measurement platform, relevant aspects of stratospheric meteorology, operational considerations and instrument design and engineering. PMID:25404681

  7. Investigation of SO2, HCl and NOx, control from waste incinerators using a novel additive in a pilot scale reactor.

    PubMed

    Williams, P T; Nimmo, W; Patsias, A; Hall, W

    2006-05-01

    A pilot scale experimental investigation of the use of a novel additive, calcium magnesium acetate, for the simultaneous control of SO2, HCl and NOx has been carried out. The pilot scale reactor simulated the furnace and flue gas conditions of a typical large scale waste incinerator and was a vertical 4m high reactor operated at 80 kW. The calcium magnesium acetate was added as a wet spray to the reactor at temperatures above 750 degrees C. The influence of the calcium magnesium acetate dose rate was investigated on the simultaneous removal of SO2, HCl and NOx. Maximum reductions were achieved at a Ca/S ratio (or Ca/Cl ratio) of 2.5 and were, 70% for SO2, 45% for HCl and 18% for NOx for each of the pollutant gases respectively. PMID:16749624

  8. Numerical experiments on the stability of controlled boundary layers

    NASA Technical Reports Server (NTRS)

    Zang, Thomas A.; Hussaini, M. Y.

    1988-01-01

    Nonlinear simulations are presented for instability and transition in parallel water boundary layers subjected to pressure gradient, suction, or heating control. In the nonlinear regime, finite amplitude, 2-D Tollmein-Schlichting waves grow faster than is predicted by linear theory. Moreover, this discrepancy is greatest in the case of heating control. Likewise, heating control is found to be the least effective in delaying secondary instabilities of both the fundamental and subharmonic type. Flow field details (including temperature profiles) are presented for both the uncontrolled boundary layer and the heated boundary layer.

  9. Active Noise Control Experiments using Sound Energy Flu

    NASA Astrophysics Data System (ADS)

    Krause, Uli

    2015-03-01

    This paper reports on the latest results concerning the active noise control approach using net flow of acoustic energy. The test set-up consists of two loudspeakers simulating the engine noise and two smaller loudspeakers which belong to the active noise system. The system is completed by two acceleration sensors and one microphone per loudspeaker. The microphones are located in the near sound field of the loudspeakers. The control algorithm including the update equation of the feed-forward controller is introduced. Numerical simulations are performed with a comparison to a state of the art method minimising the radiated sound power. The proposed approach is experimentally validated.

  10. Experiments on the active control of transitional boundary layers

    NASA Astrophysics Data System (ADS)

    Nelson, P. A.; Rioual, J.-L.; Fisher, M. J.

    Experimental results are presented which demonstrate that the streamwise position of the transition region of a flat plate boundary layer can be actively controlled. The means of control is through the application of suction through the surface of the plate, a progressive increase in suction rate being capable of producing transition at progressively larger distances downstream from the plate leading edge. A simple digital feedback regulator based on an integral control law is shown to be most effective in regulating the position of transition, an error signal being derived from measurements of pressure fluctuations on the surface of the plate.

  11. Addition of hydrogen peroxide for the simultaneous control of bromate and odor during advanced drinking water treatment using ozone.

    PubMed

    Wang, Yongjing; Yu, Jianwei; Zhang, Dong; Yang, Min

    2014-03-01

    Complete removal of the characteristic septic/swampy odor from Huangpu River source water could only be achieved under an ozone dose as high as 4.0 mg/L in an ozone-biological activated carbon (O3-BAC) process, which would lead to the production of high concentrations of carcinogenic bromate due to the high bromide content. This study investigated the possibility of simultaneous control of bromate and the septic/swampy odor by adding H2O2 prior to the O3-BAC process for the treatment of Huangpu River water. H2O2 addition could reduce the bromate concentration effectively at an H2O2/O3 (g/g) ratio of 0.5 or higher. At the same time, the septic/swampy odor removal was enhanced by the addition of H2O2, although optimization of the H2O2/O3 ratio was required for each ozone dose. At an ozone dose of 2.0 mg/L, the odor was removed completely at an H2O2/O3 ratio of 0.5. The results indicated that H2O2 application at a suitable dose could enhance the removal of the septic/swampy odor while suppressing the formation of bromate during ozonation of Huangpu River source water. PMID:25079267

  12. From the N-Heterocyclic Carbene-Catalyzed Conjugate Addition of Alcohols to the Controlled Polymerization of (Meth)acrylates.

    PubMed

    Ottou, Winnie Nzahou; Bourichon, Damien; Vignolle, Joan; Wirotius, Anne-Laure; Robert, Fredéric; Landais, Yannick; Sotiropoulos, Jean-Marc; Miqueu, Karinne; Taton, Daniel

    2015-06-22

    Among various N-heterocyclic carbenes (NHCs) tested, only 1,3-bis(tert-butyl)imidazol-2-ylidene (NHC(tBu) ) proved to selectively promote the catalytic conjugate addition of alcohols onto (meth)acrylate substrates. This rather rare example of NHC-catalyzed 1,4-addition of alcohols was investigated as a simple means to trigger the polymerization of both methyl methacrylate and methyl acrylate (MMA and MA, respectively). Well-defined α-alkoxy poly(methyl (meth)acrylate) (PM(M)A) chains, the molar masses of which could be controlled by the initial [(meth)acrylate]0/[ROH]0 molar ratio, were ultimately obtained in N,N-dimethylformamide at 25 °C. A hydroxyl-terminated poly(ethylene oxide) (PEO-OH) macro-initiator was also employed to directly access PEO-b-PMMA amphiphilic block copolymers. Investigations into the reaction mechanism by DFT calculations revealed the occurrence of two competitive concerted pathways, involving either the activation of the alcohol or that of the monomer by NHC(tBu) . PMID:26013759

  13. Controlling crystallization process and thermal stability of a binary Cu-Zr bulk metallic glass via minor element addition

    NASA Astrophysics Data System (ADS)

    Zhang, S. T.; Wang, Q.; Liu, T. T.; Liu, J. J.

    2015-09-01

    In this paper, the effect of minor element addition on the initial structural evolution during crystallization in a simple binary Cu-Zr bulk metallic glass (BMG) forming liquid has been investigated by using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Despite no changes in the completely crystallized products, the remarkable opposite impacts on the supercooled liquid region (SLR) and crystallization reaction rate constant Kcr are observed as a result of minor selective additions of an affine element, i.e., Sn and an immiscible element, i.e., Nb into the Cu-Zr BMG alloy, respectively. Furthermore, it is demonstrated that the primary devitrification pathway and crystalline phases are simultaneously modified, which leads to significant changes in kinetics of atomic rearrangement and thus thermal stability of this material. Such a finding offers a promising way to control the type of primary crystalline phases of BMG-forming metallic supercooled liquids to synthesize novel BMGs or BMG matrix composites for structural or functional applications.

  14. Experimental investigations of the swirling flow in the conical diffuser using flow-feedback control technique with additional energy source

    NASA Astrophysics Data System (ADS)

    Tǎnasǎ, C.; Bosioc, A. I.; Susan-Resiga, R. F.; Muntean, S.

    2012-11-01

    The previous experimental and numerical investigations of decelerated swirling flows in conical diffusers have demonstrated that water injection along to the axis mitigates the pressure fluctuations associated to the precessing vortex rope [1]. However, for swirling flows similar to Francis turbines operated at partial discharge, the water jet becomes effective when the jet discharge is larger than 10% from the turbine discharge, leading to large volumetric losses when the jet is supplied from upstream the runner. As a result, it was introduced a new approach for supplying the jet by using a fraction of the discharge collected downstream the conical diffuser [2]. This is called flow-feedback control technique (FFCT) and it was investigated experimentally in order to assess its capability [3]. The FFCT approach not requires additional energy to supply the jet. Consequently, the turbine efficiency is not diminished due to the volumetric losses injected even if around 10% of the main flow is used. However, the equivalent amplitude of the pressure pulsations associated to the vortex rope decreases with 30% if 10% jet discharge is applied [3]. Using 12% water jet discharge from upstream then the equivalent amplitude of the pressure pulsations is mitigated with 70% according to Bosioc et al. [4]. In our case, an extra 2% jet discharge is required in order to obtain similar results with FFCT. This extra discharge is provided using an additional energy source. Therefore, the paper presents experimental investigation performed with FFCT with additional energy source. The experimental results obtained with this technique are compared against FFCT and the swirling flow with vortex rope, respectively.

  15. A single-axis testbed for slewing control experiments

    NASA Technical Reports Server (NTRS)

    Hamilton, Jonathan; Lee, Gordon K. F.; Juang, Jer-Nan

    1990-01-01

    A simple single-axis testbed is described, and initial experimental results are presented to illustrate collocated and noncollocated control for this structure. The testbed is made up of a pair of single-axis flexible beams attached to a DC servo motor. An optical encoder and strain gauges provide hub and beam position information, respectively. The system is driven by an IBM PC system; with a motor controller, a programmable digital filter processes position error information through user-selected gains and pole-zero configurations. A 25-kHz data acquisition system provides the necessary interface between processor and motor. The control approaches currently being investigated include collocated PD control and noncollocated phase compensation.

  16. Study of thermal control systems for orbiting power systems. Materials experiment carrier thermal control system study

    NASA Technical Reports Server (NTRS)

    Fleming, M. L.

    1980-01-01

    Four possible arrangements of the materials experiment carrier (MEC) and power system (PS) thermal control loops were defined which would provide one kW of heat rejection for each kW of power to the MEC payload. These arrangements were compared to the baseline reference concept which provides only 16 kW heat rejection to show the cost of obtaining symmetry in terms of dollars, weight, complexity, growth potential, ease of integration, technology and total launch weight. The results of these comparisons was that the concept which splits the PS thermal control loop into two systems, one to reject PS waste heat and one payload waste heat, appeared favorable. The fluid selection study resulted in recommendation of FC72 as the MEC heat transport fluid based on the thermal and physical characteristics. The coatings reviewed indicated anodized and alodine treated aluminum surfaces or silver teflon are the best choices for the MEC vehicle where durability is an important factor. For high temperature radiators silver teflon or zinc orthotitanate are recommended choices.

  17. Infection control policies and guidelines--Scandinavian experience.

    PubMed

    Nyström, B

    1991-06-01

    In the Scandinavian countries few regulations govern hospital infection control. In Sweden a common procedure manual is used nationwide, consisting of guidelines covering a wide range of nursing and medical procedures performed by the nursing staff. It is revised every fifth year. A recent enquiry to over 150 wards in some 100 hospitals demonstrated that the manual is widely accepted and used. In the other Scandinavian countries, guidelines and policies on a variety of infection control topics have been published. PMID:1679772

  18. Addition of home-based cognitive retraining to treatment as usual in first episode schizophrenia patients: A randomized controlled study

    PubMed Central

    Hegde, Shantala; Rao, Shobini L.; Raguram, Ahalya; Gangadhar, Bangalore N.

    2012-01-01

    Objective: We examined the effectiveness of a 2-month-long home-based cognitive retraining program together with treatment as usual (TAU; psychoeducation and drug therapy) on neuropsychological functions, psychopathology, and global functioning in patients with first episode schizophrenia (FES) as well as on psychological health and perception of level of family distress in their caregivers. Materials and Methods: Forty-five FES patients were randomly assigned to either treatment group receiving home-based cognitive retraining along with TAU (n=22) or to control group receiving TAU alone (n=23). Patients and caregivers received psychoeducation. Patients and one of their caregivers were assessed for the above parameters at baseline, post-assessment (2 months) and at 6-months follow-up assessment. Results: Of the 45 patients recruited, 12 in the treatment group and 11 in the control group completed post-intervention and follow-up assessments. Addition of home-based cognitive retraining along with TAU led to significant improvement in neuropsychological functions of divided attention, concept formation and set-shifting ability, and planning. Effect sizes were large, although the sample size was small. Conclusions: Home-based cognitive retraining program has shown promise. However, further studies examining this program on a larger cohort with rigorous design involving independent raters are suggested. PMID:22556432

  19. A Nonlinear, Multiinput, Multioutput Process Control Laboratory Experiment

    ERIC Educational Resources Information Center

    Young, Brent R.; van der Lee, James H.; Svrcek, William Y.

    2006-01-01

    Experience in using a user-friendly software, Mathcad, in the undergraduate chemical reaction engineering course is discussed. Example problems considered for illustration deal with simultaneous solution of linear algebraic equations (kinetic parameter estimation), nonlinear algebraic equations (equilibrium calculations for multiple reactions and…

  20. A Controlled Drug-Delivery Experiment Using Alginate Beads

    ERIC Educational Resources Information Center

    Farrell, Stephanie; Vernengo, Jennifer

    2012-01-01

    This paper describes a simple, cost-effective experiment which introduces students to drug delivery and modeling using alginate beads. Students produce calcium alginate beads loaded with drug and measure the rate of release from the beads for systems having different stir rates, geometries, extents of cross-linking, and drug molecular weight.…

  1. Inventory Control. Easily Made Electronic Device for Conductivity Experiments.

    ERIC Educational Resources Information Center

    Gadek, Frank J.

    1987-01-01

    Describes how to construct an electronic device to be used in conductivity experiments using a 35 millimeter film canister, nine volt battery replacement snaps, a 200-300 ohm resistor, and a light-emitting diode. Provides a diagram and photographs of the device. (TW)

  2. Additional Saturday rehabilitation improves functional independence and quality of life and reduces length of stay: a randomized controlled trial

    PubMed Central

    2013-01-01

    Background Many inpatients receive little or no rehabilitation on weekends. Our aim was to determine what effect providing additional Saturday rehabilitation during inpatient rehabilitation had on functional independence, quality of life and length of stay compared to 5 days per week of rehabilitation. Methods This was a multicenter, single-blind (assessors) randomized controlled trial with concealed allocation and 12-month follow-up conducted in two publically funded metropolitan inpatient rehabilitation facilities in Melbourne, Australia. Patients were eligible if they were adults (aged ≥18 years) admitted for rehabilitation for any orthopedic, neurological or other disabling conditions excluding those admitted for slow stream rehabilitation/geriatric evaluation and management. Participants were randomly allocated to usual care Monday to Friday rehabilitation (control) or to Monday to Saturday rehabilitation (intervention). The additional Saturday rehabilitation comprised physiotherapy and occupational therapy. The primary outcomes were functional independence (functional independence measure (FIM); measured on an 18 to 126 point scale), health-related quality of life (EQ-5D utility index; measured on a 0 to 1 scale, and EQ-5D visual analog scale; measured on a 0 to 100 scale), and patient length of stay. Outcome measures were assessed on admission, discharge (primary endpoint), and at 6 and 12 months post discharge. Results We randomly assigned 996 adults (mean (SD) age 74 (13) years) to Monday to Saturday rehabilitation (n = 496) or usual care Monday to Friday rehabilitation (n = 500). Relative to admission scores, intervention group participants had higher functional independence (mean difference (MD) 2.3, 95% confidence interval (CI) 0.5 to 4.1, P = 0.01) and health-related quality of life (MD 0.04, 95% CI 0.01 to 0.07, P = 0.009) on discharge and may have had a shorter length of stay by 2 days (95% CI 0 to 4, P = 0.1) when compared to

  3. Experiments in identification and control of flexible-link manipulators

    NASA Technical Reports Server (NTRS)

    Yurkovich, Stephen; Tzes, Anthony P.; Pacheco, Fernando E.

    1989-01-01

    Interest in the study of flexible-link manipulators for space-based applications has risen strongly in recent years. Moreover, numerous experimental results have appeared for the various problems in the modeling, identification and control of such systems. Nevertheless, relatively little literature has appeared involving laboratory verification of tuning controllers for certain types of realistic flexible-link manipulators. Specifically flexible-link manipulators which are required to maintain endpoint accuracy while manipulating loads that are possibly unknown and varying as they undergo disturbance effects from the environment and workspace. Endpoint position control of flexible-link manipulators in these areas are discussed, with laboratory setups consisting of one and two-link manipulators.

  4. Methods for building an inexpensive computer-controlled olfactometer for temporally precise experiments

    PubMed Central

    Lundström, Johan N.; Gordon, Amy R.; Alden, Eva C.; Boesveldt, Sanne; Albrecht, Jessica

    2010-01-01

    Many human olfactory experiments call for fast and stable stimulus-rise times as well as exact and stable stimulus-onset times. Due to these temporal demands, an olfactometer is often needed. However, an olfactometer is a piece of equipment that either comes with a high price tag or requires a high degree of technical expertise to build and/or to run. Here, we detail the construction of an olfactometer that is constructed almost exclusively with “off-the-shelf” parts, requires little technical knowledge to build, has relatively low price tags, and is controlled by E-Prime, a turnkey-ready and easily-programmable software commonly used in psychological experiments. The olfactometer can present either solid or liquid odor sources, and it exhibits a fast stimulus-rise time and a fast and stable stimulus-onset time. We provide a detailed description of the olfactometer construction, a list of its individual parts and prices, as well as potential modifications to the design. In addition, we present odor onset and concentration curves as measured with a photoionization detector, together with corresponding GC/MS analyses of signal-intensity drop (5.9%) over a longer period of use. Finally, we present data from behavioral and psychophysiological recordings demonstrating that the olfactometer is suitable for use during event-related EEG experiments. PMID:20688109

  5. Exposure of Polymer Film Thermal Control Materials on the Materials International Space Station Experiment (MISSE)

    NASA Technical Reports Server (NTRS)

    Dever, Joyce; Miller, Sharon; Messer, Russell; Sechkar, Edward; Tollis, Greg

    2002-01-01

    Seventy-nine samples of polymer film thermal control (PFTC) materials have been provided by the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) for exposure to the low Earth orbit environment on the exterior of the International Space Station (ISS) as part of the Materials International Space Station Experiment (MISSE). MISSE is a materials flight experiment sponsored by the Air Force Research Lab/Materials Lab and NASA. This paper will describe background, objectives, and configurations for the GRC PFTC samples for MISSE. These samples include polyimides, fluorinated polyimides, and Teflon fluorinated ethylene propylene (FEP) with and without second-surface metallizing layers and/or surface coatings. Also included are polyphenylene benzobisoxazole (PBO) and a polyarylene ether benzimidazole (TOR-LM). On August 16, 2001, astronauts installed passive experiment carriers (PECs) on the exterior of the ISS in which were located twenty-eight of the GRC PFTC samples for 1-year space exposure. MISSE PECs for 3-year exposure, which will contain fifty-one GRC PFTC samples, will be installed on the ISS at a later date. Once returned from the ISS, MISSE GRC PFTC samples will be examined for changes in optical and mechanical properties and atomic oxygen (AO) erosion. Additional sapphire witness samples located on the AO exposed trays will be examined for deposition of contaminants.

  6. Radiopurity control in the NEXT-100 double beta decay experiment

    SciTech Connect

    Álvarez, V.; Cárcel, S.; Cervera, A.; Díaz, J.; Ferrario, P.; Gil, A.; Gómez-Cadenas, J. J.; Laing, A.; Liubarsky, I.; Lorca, D.; Martín-Albo, J.; Martínez, A.; Monrabal, F.; Muñoz Vidal, J.; Nebot-Guinot, M.; Rodríguez, J.; Serra, L.; Simón, A.; Sofka, C.; Sorel, M.; and others

    2013-08-08

    An extensive material screening and selection process is underway in the construction of the 'Neutrino Experiment with a Xenon TPC' (NEXT), intended to investigate neutrinoless double beta decay using a high-pressure xenon gas TPC filled with 100 kg of Xe enriched in {sup 136}Xe. Determination of the radiopurity levels of the materials is based on gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterráneo de Canfranc (Spain) and also on Glow Discharge Mass Spectrometry. Materials to be used in the shielding, pressure vessel, electroluminescence and high voltage components and energy and tracking readout planes have been already taken into consideration. The measurements carried out are presented, describing the techniques and equipment used, and the results obtained are shown, discussing their implications for the NEXT experiment.

  7. Experience with ISO quality control in assisted reproductive technology.

    PubMed

    Alper, Michael M

    2013-12-01

    Assisted reproductive technology (ART) programs are complex organizations requiring the integration of multiple disciplines. ISO 9001:2008 is a quality management system that is readily adaptable to an ART program. The value that ISO brings to the entire organization includes control of documents, clear delineation of responsibilities of staff members, documentation of the numerous processes and procedures, improvement in tracking and reducing errors, and overall better control of systems. A quality ART program sets quality objectives and monitors their progress. ISO provides a sense of transparency within the organization and clearer understanding of how service is provided to patients. Most importantly, ISO provides the framework to allow for continual improvement. PMID:24112531

  8. [Internal quality control for antimicrobial susceptibility test: an experience feedback].

    PubMed

    Vedy, Serge

    2012-01-01

    Internal quality control (IQC) position in antimicrobial susceptibility testing must be evaluated attentively before using. Ours S. aureus ATCC 25923 use during year 2011 has given precious information that can be useful for other laboratories. First, IQC should never be used before checking that all the realisation process steps are controlled. It will then appear that reagents are the most susceptible to give false results. That's what happens in 2.74% of antimicrobial susceptibility test. IQC is then useful to limit their clinical's impact. However, IQC use also shows that quality improvement will be difficult without industrial producer's involvement. PMID:22826843

  9. Spread of arbitrary conventions among chimpanzees: a controlled experiment.

    PubMed

    Bonnie, Kristin E; Horner, Victoria; Whiten, Andrew; de Waal, Frans B M

    2007-02-01

    Wild chimpanzees (Pan troglodytes) have a rich cultural repertoire--traditions common in some communities are not present in others. The majority of reports describe functional, material traditions, such as tool use. Arbitrary conventions have received far less attention. In the same way that observations of material culture in wild apes led to experiments to confirm social transmission and identify underlying learning mechanisms, experiments investigating how arbitrary habits or conventions arise and spread within a group are also required. The few relevant experimental studies reported thus far have relied on cross-species (i.e. human-ape) interaction offering limited ecological validity, and no study has successfully generated a tradition not involving tool use in an established group. We seeded one of two rewarded alternative endpoints to a complex sequence of behaviour in each of two chimpanzee groups. Each sequence spread in the group in which it was seeded, with many individuals unambiguously adopting the sequence demonstrated by a group member. In one group, the alternative sequence was discovered by a low ranking female, but was not learned by others. Since the action-sequences lacked meaning before the experiment and had no logical connection with reward, chimpanzees must have extracted both the form and benefits of these sequences through observation of others. PMID:17164200

  10. Aerodynamics of ski jumping flight and its control: I. Experiments

    NASA Astrophysics Data System (ADS)

    Jung, Daehan; Bang, Kyeongtae; Kim, Heesu; Ahn, Eunhye; Choi, Haecheon

    2015-11-01

    In a ski jumping competition, it is essential to analyze the effect of various posture parameters of a ski jumper to achieve a longer flight distance. For this purpose, we construct a model of a ski jumper by using three-dimensional surface data obtained by scanning a ski jumper's body (Mr. Chil-Ku Kang, member of the Korean national team). An experiment on this model is conducted in a wind tunnel. We consider four posture parameters (forward leaning angle, ski opening angle, ski rolling angle, and ski spacing) and measure the drag and lift forces for various flight postures at various angles of attack (α = 0° - 40°) and Reynolds numbers (Re = 5.4 × 105 - 1.6 × 106) based on the length of the jump ski. Then, we derive optimum values of posture parameters for maximum lift-to-drag ratio using a response surface method. We also conduct a full-scale wind tunnel experiment with members of the Korean national team and confirm the results obtained from the experiment on the model. Supported by the NRF program (2014M3C1B1033848).

  11. Experiments on rotamak plasma equilibrium and shape control

    SciTech Connect

    Petrov, Yuri; Yang Xiaokang; Wang Yonghui; Huang, T.-S.

    2010-01-15

    A set of magnetic shaping coils and copper rings is installed in cylindrical chamber rotamak to allow for an active equilibrium control in 40 ms plasma discharges. The coils, which are powered by programmable current source, are used to control both the plasma shape and the boundary poloidal magnetic flux. Without the active equilibrium control, the boundary flux drops from its vacuum value of 0.3 mWb to zero after the plasma current is generated. If the coils are activated, the boundary magnetic flux can be sustained within the 0.2-0.3 mWb range, thus keeping the separatrix away from chamber wall during whole period of the shot. The passive copper rings help in eliminating the fast variations of the boundary magnetic flux. The response of rotamak plasma to the active equilibrium control is drastically different in regimes with or without external toroidal field. A model is presented that describes the change in plasma shape, plasma current, and pressure under the effect of active equilibrium coils.

  12. Dimensions of Locus of Control: Impact of Early Educational Experiences.

    ERIC Educational Resources Information Center

    Stephens, Mark W.

    A study was conducted to: (1) assess the equivalence of the Nowicki Strickland Locus of Control Scale for Children, the Stephens-Delys Reinforcement Contingency Interview, and the Gruen-Korte-Stephens test and the construct validity of each; and (2) investigate the impact on IE of the open classroom Follow Through program sponsored by the…

  13. Experiments in structural dynamics and control using a grid

    NASA Technical Reports Server (NTRS)

    Montgomery, R. C.

    1985-01-01

    Future spacecraft are being conceived that are highly flexible and of extreme size. The two features of flexibility and size pose new problems in control system design. Since large scale structures are not testable in ground based facilities, the decision on component placement must be made prior to full-scale tests on the spacecraft. Control law research is directed at solving problems of inadequate modelling knowledge prior to operation required to achieve peak performance. Another crucial problem addressed is accommodating failures in systems with smart components that are physically distributed on highly flexible structures. Parameter adaptive control is a method of promise that provides on-orbit tuning of the control system to improve performance by upgrading the mathematical model of the spacecraft during operation. Two specific questions are answered in this work. They are: What limits does on-line parameter identification with realistic sensors and actuators place on the ultimate achievable performance of a system in the highly flexible environment? Also, how well must the mathematical model used in on-board analytic redundancy be known and what are the reasonable expectations for advanced redundancy management schemes in the highly flexible and distributed component environment?

  14. Second Careers: The Air Traffic Controller Experience and Beyond.

    ERIC Educational Resources Information Center

    Batten, Michael D.

    1978-01-01

    Second careers are examined from an organizational viewpoint, and new directions for education-work policy, suggested by a unique second career program of the Federal Aviation Administration for air traffic controllers, are explored. Focus is on age, organizational and training factors, and community involvement. (Author/JMD)

  15. Apollo experience report: Lunar module display and control subsystem

    NASA Technical Reports Server (NTRS)

    Farkas, A. J.

    1972-01-01

    The lunar module display and control subsystem equipment is described with emphasis on major problems and their solutions. Included in the discussion of each item is a description of what the item does and how the item is constructed. The development, hardware history, and testing for each item are also presented.

  16. PID Controller Settings Based on a Transient Response Experiment

    ERIC Educational Resources Information Center

    Silva, Carlos M.; Lito, Patricia F.; Neves, Patricia S.; Da Silva, Francisco A.

    2008-01-01

    An experimental work on controller tuning for chemical engineering undergraduate students is proposed using a small heat exchange unit. Based upon process reaction curves in open-loop configuration, system gain and time constant are determined for first order model with time delay with excellent accuracy. Afterwards students calculate PID…

  17. Construction of vanes for helical pitch flow control in the Madison Dynamo Experiment

    NASA Astrophysics Data System (ADS)

    Clark, M. M.; Taylor, N. Z.; Kaplan, E. J.; Rasmus, A. M.; Rahbarnia, K.; Nornberg, M. D.; Wallace, J. P.; Forest, C. B.

    2011-10-01

    The Madison Dynamo Experiment (MDE) comprises a 1 m diameter spherical chamber that contains liquid sodium flowing under the influence of two counter rotating impellers and vanes close to the vessel wall. MDE seeks to observe a magnetic field grow at the expense of kinetic energy in the liquid sodium flow. The most recent upgrade has been the addition of three vanes symmetrically located around each impeller to control the helical pitch of the flow and thus minimize the critical velocity at which the dynamo onset occurs. Each of the new vane/shaft assemblies can be rotated anywhere in a full circle about the shaft axis and then fixed to the desired position. The design and construction of the so called rotatable vanes will be discussed and illustrated today. This work is supported by the NSF/DOE partnership in plasma physics.

  18. Controlled Experiment Replication in Evaluation of E-Learning System's Educational Influence

    ERIC Educational Resources Information Center

    Grubisic, Ani; Stankov, Slavomir; Rosic, Marko; Zitko, Branko

    2009-01-01

    We believe that every effectiveness evaluation should be replicated at least in order to verify the original results and to indicate evaluated e-learning system's advantages or disadvantages. This paper presents the methodology for conducting controlled experiment replication, as well as, results of a controlled experiment and an internal…

  19. 75 FR 24748 - Johnson Controls, Inc., Automotive Experience Division, Including Workers Whose Unemployment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-05

    ... of Johnson Controls, Inc., Automotive Experience Division, Greenfield, Ohio. The notice was published in the Federal Register on December 11, 2009 (74 FR 65798). At the request of the state, the... Employment and Training Administration Johnson Controls, Inc., Automotive Experience Division,...

  20. Engineering of an MBR supernatant fouling layer by fine particles addition: a possible way to control cake compressibility.

    PubMed

    Teychene, Benoît; Guigui, Christelle; Cabassud, Corinne

    2011-02-01

    For membrane bioreactors (MBR) applied to wastewater treatment membrane fouling is still the prevalent issue. The main limiting phenomena related to fouling is a sudden jump of the transmembrane pressure (TMP) often attributed to the collapse of the fouling layer. Among existing techniques to avoid or to delay this collapse, the addition of active particles membrane fouling reducers (polymer, resins, powdered activated carbon (PAC), zeolithe...) showed promising results. Thus the main objective of this work is to determine if fouling can be reduced by inclusion of inert particles (500 nm and inert compared to other fouling reducers) and which is the impact on filtration performances of the structuring of the fouling. Those particles were chosen for their different surface properties and their capability to form well structured layer. Results, obtained at constant pressure in dead end mode, show that the presence of particles changes foulant deposition and induces non-compressible fouling (in the range of 0.5-1 bar) and higher rejection values compared to filtration done on supernatant alone. Indeed dead end filtration tests show that whatever interactions between biofluid and particles, the addition of particles leads to better filtration performances (in terms of rejection, and fouling layer compressibility). Moreover results confirm the important role played by macromolecular compounds, during supernatant filtration, creating highly compressible and reversible fouling. In conclusion, this study done at lab-scale suggests the potential benefit to engineer fouling structure to control or to delay the collapse of the fouling layer. Finally this study offers the opportunities to enlarge the choice of membrane fouling reducers by taking into consideration their ability to form more consistent fouling (i.e. rigid, structured fouling). PMID:21232780

  1. The additional value of a night splint to eccentric exercises in chronic midportion Achilles tendinopathy: a randomised controlled trial

    PubMed Central

    de Vos, R J; Weir, A; Visser, R J A; de Winter, ThC; Tol, J L

    2007-01-01

    Aim To assess whether the use of a night splint is of added benefit on functional outcome in treating chronic midportion Achilles tendinopathy. Methods This was a single‐blind, prospective, single centre, randomised controlled trial set in the Sports Medical Department, The Hague Medical Centre, The Netherlands. Inclusion criteria were: age 18–70 years, active participation in sports, and tendon pain localised at 2–7 cm from distal insertion. Exclusion criteria were: insertional disorders, partial or complete ruptures, or systemic illness. 70 tendons were included and randomised into one of two treatment groups: eccentric exercises with a night splint (night splint group, n = 36) or eccentric exercises only (eccentric group, n = 34). Interventions Both groups completed a 12‐week heavy‐load eccentric training programme. One group received a night splint in addition to eccentric exercises. At baseline and follow‐up at 12 weeks, patient satisfaction, Victorian Institute of Sport Assessment–Achilles questionnaire (VISA‐A) score and reported compliance were recorded by a single‐blind trained researcher who was blinded to the treatment. Results After 12 weeks, patient satisfaction in the eccentric group was 63% compared with 48% in the night splint group. The VISA‐A score significantly improved in both groups; in the eccentric group from 50.1 to 68.8 (p = 0.001) and in the night splint group from 49.4 to 67.0 (p<0.001). There was no significant difference between the two groups in VISA‐A score (p = 0.815) and patient satisfaction (p = 0.261). Conclusion A night splint is not beneficial in addition to eccentric exercises in the treatment of chronic midportion Achilles tendinopathy. PMID:17178774

  2. Neural Correlates of Task Cost for Stance Control with an Additional Motor Task: Phase-Locked Electroencephalogram Responses

    PubMed Central

    Hwang, Ing-Shiou; Huang, Cheng-Ya

    2016-01-01

    With appropriate reallocation of central resources, the ability to maintain an erect posture is not necessarily degraded by a concurrent motor task. This study investigated the neural control of a particular postural-suprapostural procedure involving brain mechanisms to solve crosstalk between posture and motor subtasks. Participants completed a single posture task and a dual-task while concurrently conducting force-matching and maintaining a tilted stabilometer stance at a target angle. Stabilometer movements and event-related potentials (ERPs) were recorded. The added force-matching task increased the irregularity of postural response rather than the size of postural response prior to force-matching. In addition, the added force-matching task during stabilometer stance led to marked topographic ERP modulation, with greater P2 positivity in the frontal and sensorimotor-parietal areas of the N1-P2 transitional phase and in the sensorimotor-parietal area of the late P2 phase. The time-frequency distribution of the ERP primary principal component revealed that the dual-task condition manifested more pronounced delta (1–4 Hz) and beta (13–35 Hz) synchronizations but suppressed theta activity (4–8 Hz) before force-matching. The dual-task condition also manifested coherent fronto-parietal delta activity in the P2 period. In addition to a decrease in postural regularity, this study reveals spatio-temporal and temporal-spectral reorganizations of ERPs in the fronto-sensorimotor-parietal network due to the added suprapostural motor task. For a particular set of postural-suprapostural task, the behavior and neural data suggest a facilitatory role of autonomous postural response and central resource expansion with increasing interregional interactions for task-shift and planning the motor-suprapostural task. PMID:27010634

  3. A Serious Videogame as an Additional Therapy Tool for Training Emotional Regulation and Impulsivity Control in Severe Gambling Disorder

    PubMed Central

    Tárrega, Salomé; Castro-Carreras, Laia; Fernández-Aranda, Fernando; Granero, Roser; Giner-Bartolomé, Cristina; Aymamí, Neus; Gómez-Peña, Mónica; Santamaría, Juan J.; Forcano, Laura; Steward, Trevor; Menchón, José M.; Jiménez-Murcia, Susana

    2015-01-01

    Background: Gambling disorder (GD) is characterized by a significant lack of self-control and is associated with impulsivity-related personality traits. It is also linked to deficits in emotional regulation and frequently co-occurs with anxiety and depression symptoms. There is also evidence that emotional dysregulation may play a mediatory role between GD and psychopathological symptomatology. Few studies have reported the outcomes of psychological interventions that specifically address these underlying processes. Objectives: To assess the utility of the Playmancer platform, a serious video game, as an additional therapy tool in a CBT intervention for GD, and to estimate pre-post changes in measures of impulsivity, anger expression and psychopathological symptomatology. Method: The sample comprised a single group of 16 male treatment-seeking individuals with severe GD diagnosis. Therapy intervention consisted of 16 group weekly CBT sessions and, concurrently, 10 additional weekly sessions of a serious video game. Pre-post treatment scores on South Oaks Gambling Screen (SOGS), Barratt Impulsiveness Scale (BIS-11), I7 Impulsiveness Questionnaire (I7), State-Trait Anger Expression Inventory 2 (STAXI-2), Symptom Checklist-Revised (SCL-90-R), State-Trait Anxiety Inventory (STAI-S-T), and Novelty Seeking from the Temperament and Character Inventory-Revised (TCI-R) were compared. Results: After the intervention, significant changes were observed in several measures of impulsivity, anger expression and other psychopathological symptoms. Dropout and relapse rates during treatment were similar to those described in the literature for CBT. Conclusion: Complementing CBT interventions for GD with a specific therapy approach like a serious video game might be helpful in addressing certain underlying factors which are usually difficult to change, including impulsivity and anger expression. PMID:26617550

  4. Neural Correlates of Task Cost for Stance Control with an Additional Motor Task: Phase-Locked Electroencephalogram Responses.

    PubMed

    Hwang, Ing-Shiou; Huang, Cheng-Ya

    2016-01-01

    With appropriate reallocation of central resources, the ability to maintain an erect posture is not necessarily degraded by a concurrent motor task. This study investigated the neural control of a particular postural-suprapostural procedure involving brain mechanisms to solve crosstalk between posture and motor subtasks. Participants completed a single posture task and a dual-task while concurrently conducting force-matching and maintaining a tilted stabilometer stance at a target angle. Stabilometer movements and event-related potentials (ERPs) were recorded. The added force-matching task increased the irregularity of postural response rather than the size of postural response prior to force-matching. In addition, the added force-matching task during stabilometer stance led to marked topographic ERP modulation, with greater P2 positivity in the frontal and sensorimotor-parietal areas of the N1-P2 transitional phase and in the sensorimotor-parietal area of the late P2 phase. The time-frequency distribution of the ERP primary principal component revealed that the dual-task condition manifested more pronounced delta (1-4 Hz) and beta (13-35 Hz) synchronizations but suppressed theta activity (4-8 Hz) before force-matching. The dual-task condition also manifested coherent fronto-parietal delta activity in the P2 period. In addition to a decrease in postural regularity, this study reveals spatio-temporal and temporal-spectral reorganizations of ERPs in the fronto-sensorimotor-parietal network due to the added suprapostural motor task. For a particular set of postural-suprapostural task, the behavior and neural data suggest a facilitatory role of autonomous postural response and central resource expansion with increasing interregional interactions for task-shift and planning the motor-suprapostural task. PMID:27010634

  5. Using Controlled Landslide Initiation Experiments to Test Limit-Equilibrium Analyses of Slope Stability

    NASA Astrophysics Data System (ADS)

    Reid, M. E.; Iverson, R. M.; Brien, D. L.; Iverson, N. R.; Lahusen, R. G.; Logan, M.

    2004-12-01

    Most studies of landslide initiation employ limit equilibrium analyses of slope stability. Owing to a lack of detailed data, however, few studies have tested limit-equilibrium predictions against physical measurements of slope failure. We have conducted a series of field-scale, highly controlled landslide initiation experiments at the USGS debris-flow flume in Oregon; these experiments provide exceptional data to test limit equilibrium methods. In each of seven experiments, we attempted to induce failure in a 0.65m thick, 2m wide, 6m3 prism of loamy sand placed behind a retaining wall in the 31° sloping flume. We systematically investigated triggering of sliding by groundwater injection, by prolonged moderate-intensity sprinkling, and by bursts of high intensity sprinkling. We also used vibratory compaction to control soil porosity and thereby investigate differences in failure behavior of dense and loose soils. About 50 sensors were monitored at 20 Hz during the experiments, including nests of tiltmeters buried at 7 cm spacing to define subsurface failure geometry, and nests of tensiometers and pore-pressure sensors to define evolving pore-pressure fields. In addition, we performed ancillary laboratory tests to measure soil porosity, shear strength, hydraulic conductivity, and compressibility. In loose soils (porosity of 0.52 to 0.55), abrupt failure typically occurred along the flume bed after substantial soil deformation. In denser soils (porosity of 0.41 to 0.44), gradual failure occurred within the soil prism. All failure surfaces had a maximum length to depth ratio of about 7. In even denser soil (porosity of 0.39), we could not induce failure by sprinkling. The internal friction angle of the soils varied from 28° to 40° with decreasing porosity. We analyzed stability at failure, given the observed pore-pressure conditions just prior to large movement, using a 1-D infinite-slope method and a more complete 2-D Janbu method. Each method provides a static

  6. Citrus Quality Control: An NMR/MRI Problem-Based Experiment

    ERIC Educational Resources Information Center

    Erhart, Sarah E.; McCarrick, Robert M.; Lorigan, Gary A.; Yezierski, Ellen J.

    2016-01-01

    An experiment seated in an industrial context can provide an engaging framework and unique learning opportunity for an upper-division physical chemistry laboratory. An experiment that teaches NMR/MRI through a problem-based quality control of citrus products was developed. In this experiment, using a problem-based learning (PBL) approach, students…

  7. Coherent operation of detector systems and their readout electronics in a complex experiment control environment

    NASA Astrophysics Data System (ADS)

    Koestner, Stefan

    2009-09-01

    With the increasing size and degree of complexity of today's experiments in high energy physics the required amount of work and complexity to integrate a complete subdetector into an experiment control system is often underestimated. We report here on the layered software structure and protocols used by the LHCb experiment to control its detectors and readout boards. The experiment control system of LHCb is based on the commercial SCADA system PVSS II. Readout boards which are outside the radiation area are accessed via embedded credit card sized PCs which are connected to a large local area network. The SPECS protocol is used for control of the front end electronics. Finite state machines are introduced to facilitate the control of a large number of electronic devices and to model the whole experiment at the level of an expert system.

  8. Remote Manipulator System (RMS)-based Controls-Structures Interaction (CSI) flight experiment feasibility study

    NASA Technical Reports Server (NTRS)

    Demeo, Martha E.

    1990-01-01

    The feasibility of an experiment which will provide an on-orbit validation of Controls-Structures Interaction (CSI) technology, was investigated. The experiment will demonstrate the on-orbit characterization and flexible-body control of large flexible structure dynamics using the shuttle Remote Manipulator System (RMS) with an attached payload as a test article. By utilizing existing hardware as well as establishing integration, operation and safety algorithms, techniques and procedures, the experiment will minimize the costs and risks of implementing a flight experiment. The experiment will also offer spin-off enhancement to both the Shuttle RMS (SRMS) and the Space Station RMS (SSRMS).

  9. VCSELs with optically controlled current confinement: experiments and analysis

    NASA Astrophysics Data System (ADS)

    Bader, Sven; Gerlach, Philipp; Michalzik, Rainer

    2016-04-01

    We have devised a novel oxide-free and regrowth-free approach for optically controlled current confinement in vertical-cavity surface-emitting lasers (VCSELs). This is realized with a monolithically integrated phototransistor (PT), which is configured as an optical switch and embedded between the two Bragg reflectors. We have fabricated functional PT-VCSELs by one-step epitaxial growth plus metal deposition with different top contact sizes. We present light-current-voltage characteristics of the lasers as well as a simple theoretical model explaining the occurrence of a distinct turn-on point and clarify epitaxial design requirements to reach strong optically controlled current confinement.

  10. Active Thermal Control Experiments for LISA Ground Verification Testing

    NASA Astrophysics Data System (ADS)

    Higuchi, Sei; DeBra, Daniel B.

    2006-11-01

    The primary mission goal of LISA is detecting gravitational waves. LISA uses laser metrology to measure the distance between proof masses in three identical spacecrafts. The total acceleration disturbance to each proof mass is required to be below 3 × 10-15 m/s2√Hz . Optical path length variations on each optical bench must be kept below 40 pm/√Hz over 1 Hz to 0.1 mHz. Thermal variations due to, for example, solar radiation or temperature gradients across the proof mass housing will distort the spacecraft causing changes in the mass attraction and sensor location. We have developed a thermal control system developed for the LISA gravitational reference sensor (GRS) ground verification testing which provides thermal stability better than 1 mK/√Hz to f < 1 mHz and which by extension is suitable for in-flight thermal control for the LISA spacecraft to compensate solar irradiation. Thermally stable environment is very demanded for LISA performance verification. In a lab environment specifications can be met with considerable amount of insulation and thermal mass. For spacecraft, the very limited thermal mass calls for an active control system which can meet disturbance rejection and stability requirements simultaneously in the presence of long time delay. A simple proportional plus integral control law presently provides approximately 1 mK/√Hz of thermal stability for over 80 hours. Continuing development of a model predictive feed-forward algorithm will extend performance to below 1 mK/√Hz at f < 1 mHz and lower.

  11. Active spacecraft potential control: An ion emitter experiment. [Cluster mission

    NASA Technical Reports Server (NTRS)

    Riedler, W.; Goldstein, R.; Hamelin, M.; Maehlum, B. N.; Troim, J.; Olsen, R. C.; Pedersen, A.; Grard, R. J. L.; Schmidt, R.; Rudenauer, F.

    1988-01-01

    The cluster spacecraft are instrumented with ion emitters for charge neutralization. The emitters produce indium ions at 6 keV. The ion current is adjusted in a feedback loop with instruments measuring the spacecraft potential. The system is based on the evaporation of indium in the apex field of a needle. The design of the active spacecraft potential control instruments, and the ion emitters is presented.

  12. Experiments on anthelmintic control of Fasciola hepatica in Brazil.

    PubMed

    Echevarria, F A; Correa, M B; Wehrle, R D; Correa, I F

    1992-07-01

    Two separate field trials involving naturally infected cattle were carried out on two farms known to have a history of Fasciola hepatica infection. On the first farm, 15 animals per group were allocated as follows: G1, triclabendazole (TCBZ) four times a year; G2, TCBZ twice a year (May and September); G3, untreated control. All groups grazed together and after 3.5 years the animals were slaughtered and their livers examined by federal meat inspectors who condemned 100% of livers in G3 and 8.3% in G2 owing to the presence of lesions of fasciolosis. In G1 no livers were condemned. Significant differences in weight gains were not detected and fluke counts remained at low levels in the treated groups. Also, in the control group, egg counts started to decrease when animals were 2 years old. On the second farm, groups of 20 animals were treated as follows: G1, TCBZ three times a year (May, September and December); G2, TCBZ twice a year (May and September); G3, nitroxynil twice a year (May and September); G4, rafoxanide twice a year (May and September); G5, untreated controls. All animals were weighed and faecal samples examined at approximately 28-day intervals. During the period of the study, larger weight gains were detected in the TCBZ treated groups than in the others. TCBZ treatment kept F. hepatica egg counts at a lower level for longer periods than the other drugs and significant differences in weight gains were only obtained between the group receiving TCBZ three times a year and the control group. PMID:1413453

  13. Technology innovations and experience curves for nitrogen oxides control technologies.

    PubMed

    Yeh, Sonia; Rubin, Edward S; Taylor, Margaret R; Hounshell, David A

    2005-12-01

    This paper reviews the regulatory history for nitrogen oxides (NOx) pollutant emissions from stationary sources, primarily in coal-fired power plants. Nitrogen dioxide (NO2) is one of the six criteria pollutants regulated by the 1970 Clean Air Act where National Ambient Air Quality Standards were established to protect public health and welfare. We use patent data to show that in the cases of Japan, Germany, and the United States, innovations in NOx control technologies did not occur until stringent government regulations were in place, thus "forcing" innovation. We also demonstrate that reductions in the capital and operation and maintenance (O&M) costs of new generations of high-efficiency NOx control technologies, selective catalytic reduction (SCR), are consistently associated with the increasing adoption of the control technology: the so-called learning-by-doing phenomena. The results show that as cumulative world coal-fired SCR capacity doubles, capital costs decline to approximately 86% and O&M costs to 58% of their original values. The observed changes in SCR technology reflect the impact of technological advance as well as other factors, such as market competition and economies of scale. PMID:16408687

  14. A survey of experiments and experimental facilities for active control of flexible structures

    NASA Technical Reports Server (NTRS)

    Sparks, Dean W., Jr.; Horner, Garnett C.; Juang, Jer-Nan; Klose, Gerhard

    1989-01-01

    A brief survey of large space structure control related experiments and facilities was presented. This survey covered experiments performed before and up to 1982, and those of the present period (1982-...). Finally, the future planned experiments and facilities in support of the control-structure interaction (CSI) program were reported. It was stated that new, improved ground test facilities are needed to verify the new CSI design techniques that will allow future space structures to perform planned NASA missions.

  15. Digital Fly-By-Wire Flight Control Validation Experience

    NASA Technical Reports Server (NTRS)

    Szalai, K. J.; Jarvis, C. R.; Krier, G. E.; Megna, V. A.; Brock, L. D.; Odonnell, R. N.

    1978-01-01

    The experience gained in digital fly-by-wire technology through a flight test program being conducted by the NASA Dryden Flight Research Center in an F-8C aircraft is described. The system requirements are outlined, along with the requirements for flight qualification. The system is described, including the hardware components, the aircraft installation, and the system operation. The flight qualification experience is emphasized. The qualification process included the theoretical validation of the basic design, laboratory testing of the hardware and software elements, systems level testing, and flight testing. The most productive testing was performed on an iron bird aircraft, which used the actual electronic and hydraulic hardware and a simulation of the F-8 characteristics to provide the flight environment. The iron bird was used for sensor and system redundancy management testing, failure modes and effects testing, and stress testing in many cases with the pilot in the loop. The flight test program confirmed the quality of the validation process by achieving 50 flights without a known undetected failure and with no false alarms.

  16. Data Quality Control and Maintenance for the Qweak Experiment

    NASA Astrophysics Data System (ADS)

    Heiner, Nicholas; Spayde, Damon

    2014-03-01

    The Qweak collaboration seeks to quantify the weak charge of a proton through the analysis of the parity-violating electron asymmetry in elastic electron-proton scattering. The asymmetry is calculated by measuring how many electrons deflect from a hydrogen target at the chosen scattering angle for aligned and anti-aligned electron spins, then evaluating the difference between the numbers of deflections that occurred for both polarization states. The weak charge can then be extracted from this data. Knowing the weak charge will allow us to calculate the electroweak mixing angle for the particular Q2 value of the chosen electrons, which the Standard Model makes a firm prediction for. Any significant deviation from this prediction would be a prime indicator of the existence of physics beyond what the Standard Model describes. After the experiment was conducted at Jefferson Lab, collected data was stored within a MySQL database for further analysis. I will present an overview of the database and its functions as well as a demonstration of the quality checks and maintenance performed on the data itself. These checks include an analysis of errors occurring throughout the experiment, specifically data acquisition errors within the main detector array, and an analysis of data cuts.

  17. Solid film lubricants and thermal control coatings flown aboard the EOIM-3 MDA sub-experiment

    NASA Technical Reports Server (NTRS)

    Murphy, Taylor J.; David, Kaia E.; Babel, Hank W.

    1995-01-01

    Additional experimental data were desired to support the selection of candidate thermal control coatings and solid film lubricants for the McDonnell Douglas Aerospace (MDA) Space Station hardware. The third Evaluation of Oxygen Interactions With Materials Mission (EOIM-3) flight experiment presented an opportunity to study the effects of the low Earth orbit environment on thermal control coatings and solid film lubricants. MDA provided five solid film lubricants and two anodic thermal control coatings for EOIM-3. The lubricant sample set consisted of three solid film lubricants with organic binders one solid film lubricant with an inorganic binder, and one solid film lubricant with no binder. The anodize coating sample set consisted of undyed sulfuric acid anodize and cobalt sulfide dyed sulfuric acid anodize, each on two different substrate aluminum alloys. The organic and inorganic binders in the solid film lubricants experienced erosion, and the lubricating pigments experienced oxidation. MDA is continuing to assess the effect of exposure to the low Earth orbit environment on the life and friction properties of the lubricants. Results to date support the design practice of shielding solid film lubricants from the low Earth orbit environment. Post-flight optical property analysis of the anodized specimens indicated that there were limited contamination effects and some atomic oxygen and ultraviolet radiation effects. These effects appeared to be within the values predicted by simulated ground testing and analysis of these materials, and they were different for each coating and substrate.

  18. Solid film lubricants and thermal control coatings flown aboard the EOIM-3 MDA sub-experiment

    SciTech Connect

    Murphy, T.J.; David, K.E.; Babel, H.W.

    1995-02-01

    Additional experimental data were desired to support the selection of candidate thermal control coatings and solid film lubricants for the McDonnell Douglas Aerospace (MDA) Space Station hardware. The third Evaluation of Oxygen Interactions With Materials Mission (EOIM-3) flight experiment presented an opportunity to study the effects of the low Earth orbit environment on thermal control coatings and solid film lubricants. MDA provided five solid film lubricants and two anodic thermal control coatings for EOIM-3. The lubricant sample set consisted of three solid film lubricants with organic binders one solid film lubricant with an inorganic binder, and one solid film lubricant with no binder. The anodize coating sample set consisted of undyed sulfuric acid anodize and cobalt sulfide dyed sulfuric acid anodize, each on two different substrate aluminum alloys. The organic and inorganic binders in the solid film lubricants experienced erosion, and the lubricating pigments experienced oxidation. MDA is continuing to assess the effect of exposure to the low Earth orbit environment on the life and friction properties of the lubricants. Results to date support the design practice of shielding solid film lubricants from the low Earth orbit environment. Post-flight optical property analysis of the anodized specimens indicated that there were limited contamination effects and some atomic oxygen and ultraviolet radiation effects. These effects appeared to be within the values predicted by simulated ground testing and analysis of these materials, and they were different for each coating and substrate.

  19. Single-Amino Acid Modifications Reveal Additional Controls on the Proton Pathway of [FeFe]-Hydrogenase.

    PubMed

    Cornish, Adam J; Ginovska, Bojana; Thelen, Adam; da Silva, Julio C S; Soares, Thereza A; Raugei, Simone; Dupuis, Michel; Shaw, Wendy J; Hegg, Eric L

    2016-06-01

    The proton pathway of [FeFe]-hydrogenase is essential for enzymatic H2 production and oxidation and is composed of four residues and a water molecule. A computational analysis of this pathway in the [FeFe]-hydrogenase from Clostridium pasteurianum revealed that the solvent-exposed residue of the pathway (Glu282) forms hydrogen bonds to two residues outside of the pathway (Arg286 and Ser320), implying that these residues could function in regulating proton transfer. In this study, we show that substituting Arg286 with leucine eliminates hydrogen bonding with Glu282 and results in an ∼3-fold enhancement of H2 production activity when methyl viologen is used as an electron donor, suggesting that Arg286 may help control the rate of proton delivery. In contrast, substitution of Ser320 with alanine reduces the rate ∼5-fold, implying that it either acts as a member of the pathway or influences Glu282 to permit proton transfer. Interestingly, quantum mechanics/molecular mechanics and molecular dynamics calculations indicate that Ser320 does not play a structural role or indirectly influence the barrier for proton movement at the entrance of the channel. Rather, it may act as an additional proton acceptor for the pathway or serve in a regulatory role. While further studies are needed to elucidate the role of Ser320, collectively these data provide insights into the complex proton transport process. PMID:27186945

  20. Thermoelectric Converter for Loop Heat Pipe Temperature Control: Experience and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Ottenstein, Laura

    2010-01-01

    This paper describes the theoretical background and implementation methodology of using a thermoelectric converter (TEC) for operating temperature control of a loop heat pipe (LHP). In particular, experimental results from ambient and thermal vacuum tests of an LHP are presented for illustrations. The most commonly used state-of-the-art method to control the LHP operating temperature is to cold bias its compensation chamber (CC) and use an electrical heater to maintain the CC at the desired set point temperature. Although effective, this approach has its shortcomings in that the electrical heater can only provide heating to the CC, and the required power can be large under certain conditions. An alternative method is to use a TEC, which is capable of providing both heating and cooling to the CC. In this method, one side of the TEC is attached to the CC, and the other side is connected to the evaporator via a thermal strap. Using a bipolar power supply and a control algorithm, a TEC can function as a heater or a cooler, depending on the direction of the current flow. Extensive ground tests of several LHPs have demonstrated that a TEC can provide very tight temperature control for the CC. It also offers several additional advantages: (1) The LHP can operate at temperatures below its natural operating temperature at low heat loads; (2) The required heater power for a TEC is much less than that for an electrical heater; and (3) It enhances the LHP start-up success. Although the concept of using a TEC for LHP temperature control is simple, there are many factors to be considered in its implementation for space applications because the TEC is susceptible to the shear stress and yet has to sustain the dynamic load under the spacecraft launch environment. The added features that help the TEC to withstand the dynamic load will inevitably affect the TEC thermal performance. Some experiences and lessons learned are addressed in this paper.

  1. Monitoring hyporheic exchanges during a dam controlled experiment

    NASA Astrophysics Data System (ADS)

    Houzé, Clémence; Varnède, Lucie; Durand, Véronique; Pessel, Marc

    2016-04-01

    Precise understanding of the hyporheic exchanges response to stream flow fluctuations remains a great challenge for many environmental and hydrological problems. Multiplication of natural stream restoration programs and anthropic structures removal highlight that a better understanding of the hydrodynamic and ecological functioning of hyporheic exchanges is critical . The objective of this field experiment was to monitor the dynamic exchanges within the hyporheic zone due to an artificial stream head variation. Various types of measurements were performed, using natural tracers and electrical resistivity tomography (ERT). The dam downstream the studied river reach was successively lowered during two days, and raised during three days, implying river heads variations of about 15cm. The studied area was equipped with CTD probes (measuring the head and the conductivity) within the river, 2 multi-depths water sampling tubes inserted up to one meter depth within the riverbed deposits and 3 ERT profiles with various electrode spacing (20 cm, 25 cm, 50 cm). During the 5 days experiment, water sampling and ERT profiles were done regularly. Estimations of the sediments hydraulic conductivity were obtained by several slug tests in plastic tubes at different depths within the streambed. First results showed that stream fluctuation leads to a rapid hyporheic response according to chloride variations between stream and riverbed sediments. Similar results between geochemical and geophysical tools were found. A decrease in stream head leads to reduce the depth of the mixing zone, as the river gaining conditions intensify. On the contrary, we observed that an increased river head tends to deepen the hyporheic exchange zone.

  2. The LHCb Online Framework for Experiment Protection, and Global Operational Control and Monitoring

    NASA Astrophysics Data System (ADS)

    Alessio, F.; Jacobsson, R.; Schleich, S.

    2011-12-01

    The complexity and extreme parameters of the LHC, such as the stored energy, the collision frequency, the high risk of adverse background conditions and potentially damaging beam losses have demanded an unprecedented connectivity between the operation of the accelerator and the experiments at both hardware and software level. LHCb has been at the forefront of developing a software framework and hardware which connects to all of the LHC communication interfaces for timing, control and monitoring of the machine and beam parameters, in addition to its own local systems for beam and background monitoring. The framework also includes failsafe connectivity with the beam interlock system. The framework drives the global operation of the detector and is integrated into the readout control. It provides the shifters with the tools needed to take fast and well-guided decisions to run the LHCb experiment safely and efficiently. In particular, it has allowed the detector to be operated with only two shifters already at the LHC pilot run. The requirements include reliability and clarity for the shifters, and the possibility to retrieve the past conditions for offline analysis. All essential parameters are archived and an interactive analysis tool has been developed which provides overviews of the experimental performance and which allows post-analysis of any anomaly in the operation. This paper describes the architecture and the many functions, including the basis of the automation of the LHCb operational procedure and detector controls, and the information exchange between LHCb and the LHC, and finally the shifter and expert tools for monitoring the experimental conditions.

  3. Using genetics to control cattle parasites-the Rockhampton experience.

    PubMed

    Frisch, J E; O'Neill, C J; Kelly, M J

    2000-03-01

    Ever since their accidental introduction, cattle ticks, gastrointestinal nematodes and buffalo flies have been major parasites of cattle in northern Australia. Enormous effort and resources have been directed at chemical control of these parasites but the problem persists in undiminished form. The principal control measure remains the use of breeds that have some degree of parasite resistance. No breed is completely resistant and all are at times adversely affected by parasites. Complete resistance is the ultimate solution but has been generally ignored as a commercial reality. Studies at Rockhampton have demonstrated that completely resistant lines can be developed by genetic means within a commercially acceptable timeframe from even the most parasite-susceptible breeds. Genetic changes in tick and worm resistance over 15 years in response to selection for increased tick resistance in the Belmont Adaptaur (Bos taurus) line are reported. Costs and benefits of achieving increased tick resistance are examined and the applicability of the results to other breeds is discussed. Breed differences in resistance to buffalo flies and their effects on live weight are also reported and the possibility of selecting for increased buffalo fly resistance is explored. PMID:10719118

  4. In-step Two-phase Flow (TPF) Thermal Control Experiment

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Two-Phase Flow Thermal Control Experiment is part of the NASA/OAST In-Space Technology Experiments (In-STEP) Program. The experiment is configured for the Hitchhiker Shuttle payload system and consists of a capillary pumped loop, heatpipe radiator, and two-phase flow heat exchanger. The flight experiment design approach, test plan, payload design, and test components are described in outline and graphic form.

  5. Automated Testing Experience of the Linear Aerospike SR-71 Experiment (LASRE) Controller

    NASA Technical Reports Server (NTRS)

    Larson, Richard R.

    1999-01-01

    System controllers must be fail-safe, low cost, flexible to software changes, able to output health and status words, and permit rapid retest qualification. The system controller designed and tested for the aerospike engine program was an attempt to meet these requirements. This paper describes (1) the aerospike controller design, (2) the automated simulation testing techniques, and (3) the real time monitoring data visualization structure. Controller cost was minimized by design of a single-string system that used an off-the-shelf 486 central processing unit (CPU). A linked-list architecture, with states (nodes) defined in a user-friendly state table, accomplished software changes to the controller. Proven to be fail-safe, this system reported the abort cause and automatically reverted to a safe condition for any first failure. A real time simulation and test system automated the software checkout and retest requirements. A program requirement to decode all abort causes in real time during all ground and flight tests assured the safety of flight decisions and the proper execution of mission rules. The design also included health and status words, and provided a real time analysis interpretation for all health and status data.

  6. Transmission electron microscope in situ fatigue experiments: a computer-control approach.

    PubMed

    Vecchio, K S; Hunt, J A; Williams, D B

    1991-03-01

    A computer-control procedure was developed to facilitate in situ fatigue experiments within an intermediate voltage transmission electron microscope using a goniometer-type straining holder. The procedure was designed to allow sine-wave tension-tension cyclic loading of a microfatigue specimen similar in geometry to a center-crack panel fatigue specimen. Computer control allows greater freedom for the operator to control the experiments while providing better reproducibility from one test to another. Further development of this procedure is possible by coupling this computer-control technique with computer-controlled stage motion and digitized TV imaging. PMID:2045966

  7. Shaping frequency response of a vibrating plate for passive and active control applications by simultaneous optimization of arrangement of additional masses and ribs. Part II: Optimization

    NASA Astrophysics Data System (ADS)

    Wrona, Stanislaw; Pawelczyk, Marek

    2016-03-01

    It was shown in Part I that an ability to shape frequency response of a vibrating plate according to precisely defined demands has a very high practical potential. It can be used to improve acoustic radiation of the plate for required frequencies or enhance acoustic isolation of noise barriers and device casings. It can be used for both passive and active control. The proposed method is based on mounting several additional ribs and masses (passive and/or active) to the plate surface at locations followed from an optimisation process. In Part I a relevant model of such structure, as a function of arrangement of the additional elements was derived and validated. The model allows calculating natural frequencies and mode-shapes of the whole structure. The aim of this companion paper, Part II, is to present the second stage of the method. This is an optimization process that results in arrangement of the elements guaranteeing desired plate frequency response, and enhancement of controllability and observability measures. For that purpose appropriate cost functions, and constraints followed from technological feasibility are defined. Then, a memetic algorithm is employed to obtain a numerical solution with parameters of the arrangement. The optimization results are initially presented for simple cases to validate the method. Then, more complex scenarios are analysed with very special demands concerning the frequency response to present the full potential of the method. Subsequently, a laboratory experiment is presented and discussed. Finally, other areas of applications of the proposed method are shown and conclusions for future research are drawn.

  8. First Experiences Using XACML for Access Control in Distributed Systems

    NASA Technical Reports Server (NTRS)

    Lorch, Marcus; Proctor, Seth; Lepro, Rebekah; Kafura, Dennis; Shah, Sumit

    2003-01-01

    Authorization systems today are increasingly complex. They span domains of administration, rely on many different authentication sources, and manage permissions that can be as complex as the system itself. Worse still, while there are many standards that define authentication mechanisms, the standards that address authorization are less well defined and tend to work only within homogeneous systems. This paper presents XACML, a standard access control language, as one component of a distributed and inter-operable authorization framework. Several emerging systems which incorporate XACML are discussed. These discussions illustrate how authorization can be deployed in distributed, decentralized systems. Finally, some new and future topics are presented to show where this work is heading and how it will help connect the general components of an authorization system.

  9. Space simulation experiments on reaction control system thruster plumes

    NASA Technical Reports Server (NTRS)

    Cassidy, J. F.

    1972-01-01

    A space simulation procedure was developed for studying rocket plume contamination effects using a 5-pound bipropellant reaction control system thruster. Vacuum chamber pressures of 3 x 10 to the minus 5 torr (70 miles altitude) were achieved with the thruster firing in pulse trains consisting of eight pulses (50 msec on, 100 msec off, and seven minutes between pulse trains). The final vacuum was achieved by cooling all vacuum chamber surfaces to liquid helium temperature and by introducing a continuous argon leak of 48 std. cc/sec into the test chamber. An effort was made to simulate propellant system flow dynamics corresponding to actual spacecraft mission use. Fast time response liquid flow rate measurements showed that large variations occurred in the ratio of oxidizer to fuel flow for pulse-on times up to 120 msec. These variations could lead to poor combustion efficiency and the production of contamination.

  10. Radiative Transfer Theory Verified by Controlled Laboratory Experiments

    NASA Technical Reports Server (NTRS)

    Mishchenko, Michael I.; Goldstein, Dennis H.; Chowdhary, Jacek; Lompado, Arthur

    2013-01-01

    We report the results of high-accuracy controlled laboratory measurements of the Stokes reflection matrix for suspensions of submicrometer-sized latex particles in water and compare them with the results of a numerically exact computer solution of the vector radiative transfer equation (VRTE). The quantitative performance of the VRTE is monitored by increasing the volume packing density of the latex particles from 2 to 10. Our results indicate that the VRTE can be applied safely to random particulate media with packing densities up to 2. VRTE results for packing densities of the order of 5 should be taken with caution, whereas the polarized bidirectional reflectivity of suspensions with larger packing densities cannot be accurately predicted. We demonstrate that a simple modification of the phase matrix entering the VRTE based on the so-called static structure factor can be a promising remedy that deserves further examination.

  11. Radiative transfer theory verified by controlled laboratory experiments.

    PubMed

    Mishchenko, Michael I; Goldstein, Dennis H; Chowdhary, Jacek; Lompado, Arthur

    2013-09-15

    We report the results of high-accuracy controlled laboratory measurements of the Stokes reflection matrix for suspensions of submicrometer-sized latex particles in water and compare them with the results of a numerically exact computer solution of the vector radiative transfer equation (VRTE). The quantitative performance of the VRTE is monitored by increasing the volume packing density of the latex particles from 2% to 10%. Our results indicate that the VRTE can be applied safely to random particulate media with packing densities up to ∼2%. VRTE results for packing densities of the order of 5% should be taken with caution, whereas the polarized bidirectional reflectivity of suspensions with larger packing densities cannot be accurately predicted. We demonstrate that a simple modification of the phase matrix entering the VRTE based on the so-called static structure factor can be a promising remedy that deserves further examination. PMID:24104804

  12. Control of malaria: a successful experience from Viet Nam.

    PubMed Central

    Hung, Le Q.; Vries, Peter J. de; Giao, Phan T.; Nam, Nguyen V.; Binh, Tran Q.; Chong, M. T.; Quoc, N. T. T. A.; Thanh, T. N.; Hung, L. N.; Kager, P. A.

    2002-01-01

    OBJECTIVE: To follow malaria prospectively in an ethnic minority commune in the south of Viet Nam with high malaria transmission and seasonal fluctuation, during malaria control interventions using insecticide-treated bednets (ITBNs) and early diagnosis and treatment (EDT) of symptomatic patients. METHODS: From 1994 onwards the following interventions were used: distribution of ITBNs to all households with biannual reimpregnation; construction of a health post and appointment of staff trained in microscopic diagnosis and treatment of malaria; regular supply of materials and drugs; annual cross-sectional malaria surveys with treatment of all parasitaemic subjects, and a programme of community involvement and health education. Surveys were held yearly at the end of the rainy season. During the surveys, demographic data were updated. Diagnosis and treatment of malaria were free of charge. Plasmodium falciparum infection was treated with artesunate and P. vivax infection with chloroquine plus primaquine. FINDINGS: The baseline survey in 1994 recorded 716 inhabitants. Of the children under 2 years of age, 37% were parasitaemic; 56% of children aged 2-10 years, and 35% of the remaining population were parasitaemic. P. falciparum accounted for 73-79% of these infections. The respective splenomegaly rates for the above-mentioned age groups were 20%, 56%, and 32%. In 1999, the proportion of parasitaemic subjects was 4%, 7% and 1%, respectively, of which P.falciparum contributed 56%. The splenomegaly rate was 0%, 5% and 2%, respectively. CONCLUSIONS: A combination of ITBNs and EDT, provided free of charge, complemented by annual diagnosis and treatment during malaria surveys and community involvement with health education successfully brought malaria under control. This approach could be applied to other regions in the south of Viet Nam and provides a sound basis for further studies in other areas with different epidemiological patterns of malaria. PMID:12219158

  13. Effect of volcano ash additions on nutrient concentrations, bloom dynamics and community metabolism in a short-term experiment in the NW Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Weinbauer, Markus

    2016-04-01

    Volcano ash deposition is now considered as an important source of inorganic bioavailable iron which can relieve Fe-limitation in the ocean. As volcano ash also releases PO4, a experiment was performed in the NW Mediterranean Sea to test whether volcano ash deposition can affect nutrient dynamics and bloom development in a P-limited system. In a 54h experiment, it was shown that the development of a phytoplankton bloom was not enhanced or even repressed by ash additions of 2 and 20 mg l-1, whereas higher ash concentrations (200 mg l-1) induced a phytoplankton bloom as indicated by elevated Chlorophyll-a levels. Concurrently, net community production (NCP) and gross primary production (GPP) were enhanced at T24h at the highest ash additions. The metabolic balance was roughly neutral at low or no ash additions, but shifted towards phototrophy at the highest ash additions. The data on inorganic nutrient development and release estimates from ash material assays suggest relieving of P-limitation concomitant with NO3 and silicate use from ash. The concentration of TEP increased with increasing ash levels. The abundances of the heterotrophic compartment (bacteria, viruses and ciliates) also indicated dose-dependent responses. Our data suggest that heterotrophs won the competition for inorganic nutrients at ash levels of 2 and 20 mg l-1, whereas phytoplankton won at levels of 200 mg l-1. Overall, our experiments point to a strong potential of volcano ash deposition as forcing factor for nutrient dynamics and the activity of microbial plankton in a P-limited system.

  14. Guidelines to use tomato in experiments with a controlled environment.

    PubMed

    Schwarz, Dietmar; Thompson, Andrew J; Kläring, Hans-Peter

    2014-01-01

    Domesticated tomato (Solanum lycopersicum) is the most important horticultural crop worldwide. Low polymorphism at the DNA level conflicts with the wealth of morphological variation. Fruits vary widely in size, shape, and color. In contrast, genetic variation between the 16 wild relatives is tremendous. Several large seed banks provide tomato germplasm for both domesticated and wild accessions of tomato. Recently, the genomes of the inbred cultivar "Heinz 1706" (≈900 Mb), and S. pimpinellifolium (739 Mb) were sequenced. Genomic markers and genome re-sequencing data are available for >150 cultivars and accessions. Transformation of tomato is relatively easy and T-DNA insertion line collections are available. Tomato is widely used as a model crop for fruit development but also for diverse physiological, cellular, biochemical, molecular, and genetic studies. It can be easily grown in greenhouses or growth chambers. Plants grow, flower, and develop fruits well at daily light lengths between 8 and 16 h. The required daily light integral of an experiment depends on growth stage and temperature investigated. Temperature must be 10-35°C, relative humidity 30-90%, and, CO2 concentration 200-1500 μmol mol(-1). Temperature determines the speed of the phenological development while daily light integral and CO2 concentration affect photosynthesis and biomass production. Seed to seed cultivation takes 100 days at 20°C and can be shortened or delayed by temperature. Tomato may be cultivated in soil, substrates, or aeroponically without any substrate. Root volume, and water uptake requirements are primarily determined by transpiration demands of the plants. Many nutrient supply recipes and strategies are available to ensure sufficient supply as well as specific nutrient deficits/surplus. Using appropriate cultivation techniques makes tomato a convenient model plant for researchers, even for beginners. PMID:25477888

  15. Guidelines to use tomato in experiments with a controlled environment

    PubMed Central

    Schwarz, Dietmar; Thompson, Andrew J.; Kläring, Hans-Peter

    2014-01-01

    Domesticated tomato (Solanum lycopersicum) is the most important horticultural crop worldwide. Low polymorphism at the DNA level conflicts with the wealth of morphological variation. Fruits vary widely in size, shape, and color. In contrast, genetic variation between the 16 wild relatives is tremendous. Several large seed banks provide tomato germplasm for both domesticated and wild accessions of tomato. Recently, the genomes of the inbred cultivar “Heinz 1706” (≈900 Mb), and S. pimpinellifolium (739 Mb) were sequenced. Genomic markers and genome re-sequencing data are available for >150 cultivars and accessions. Transformation of tomato is relatively easy and T-DNA insertion line collections are available. Tomato is widely used as a model crop for fruit development but also for diverse physiological, cellular, biochemical, molecular, and genetic studies. It can be easily grown in greenhouses or growth chambers. Plants grow, flower, and develop fruits well at daily light lengths between 8 and 16 h. The required daily light integral of an experiment depends on growth stage and temperature investigated. Temperature must be 10–35°C, relative humidity 30–90%, and, CO2 concentration 200–1500 μmol mol−1. Temperature determines the speed of the phenological development while daily light integral and CO2 concentration affect photosynthesis and biomass production. Seed to seed cultivation takes 100 days at 20°C and can be shortened or delayed by temperature. Tomato may be cultivated in soil, substrates, or aeroponically without any substrate. Root volume, and water uptake requirements are primarily determined by transpiration demands of the plants. Many nutrient supply recipes and strategies are available to ensure sufficient supply as well as specific nutrient deficits/surplus. Using appropriate cultivation techniques makes tomato a convenient model plant for researchers, even for beginners. PMID:25477888

  16. The Navstar GPS master control station's Kalman filter experience

    NASA Technical Reports Server (NTRS)

    Scardera, Michael P.

    1990-01-01

    The Navstar Global Positioning System (GPS) is a highly accurate space based navigation system providing all weather, 24 hour a day service to both military and civilian users. The system provides a Gaussian position solution with four satellites, each providing its ephemeris and clock offset with respect to GPS time. The GPS Master Clock Station (MCS) is charged with tracking each Navstar spacecraft and precisely defining the ephemeris and clock parameters for upload into the vehicle's navigation message. Briefly described here are the Navstar system and the Kalman filter estimation process used by MCS to determine, predict, and ensure quality control for each of the satellite's ephemeris and clock states. Routine performance is shown. Kalman filter reaction and response is discussed for anomalous clock behavior and trajectory perturbations. Particular attention is given to MCS efforts to improve orbital adjust modeling. The satellite out of service time due to orbital maneuvering has been reduced in the past year from four days to under twelve hours. The planning, reference trajectory model, and Kalman filter management improvements are explained.

  17. A robot in space as a large space structures control experiment

    NASA Technical Reports Server (NTRS)

    Gran, R.

    1983-01-01

    The control systems design issues for large space structures can be addressed by a robotics experiment which defines a teleoperator or a robot or uses the RMS. The robotics control demonstration brings the large space structures control technology to an effective state of readiness and provides a useful robot when the experiment is finished. Three major options in such an experiment are the RMS, a flexible arm that is going to be put on the Shuttle for other reasons, or a dexetrous manipulator or teleoperator.

  18. Changes in water, carbon, and nitrogen fluxes with the addition of biochar to soils: lessons learned from laboratory and greenhouse experiments

    NASA Astrophysics Data System (ADS)

    Barnes, R. T.; Gallagher, M. E.; Masiello, C. A.; Liu, Z.; Dugan, B.; Rudgers, J. A.

    2011-12-01

    The addition of biochar to agricultural soils has the potential to provide a number of ecosystem services, ranging from carbon (C) sequestration to increased soil fertility and crop production. It is estimated that 0.5 to 0.9 Pg of C yr-1 can be sequestered through the addition of biochar to soils, significantly increasing the charcoal flux to the biosphere over natural inputs from fire (0.05 to 0.20 Pg C yr-1). There remain large uncertainties about biochar mobility within the environment, making it a challenge to assess the ecosystem residence time of biochar. We conducted laboratory and greenhouse experiments to understand how soil amendment with laboratory-produced biochar changes water, C, and nitrogen (N) fluxes from soils. We used column experiments to assess how biochar amendment to three types of soils (sand, organic, clay-rich) affected hydraulic conductivity and dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) fluxes. Results varied with soil type; biochar significantly decreased the hydraulic conductivity of the sand and organic soils by a factor of 10.6 and 2.7, respectively. While not statistically significant, biochar addition increased the hydraulic conductivity of the clay-rich soil by 50% on average. The addition of biochar significantly increased the DOC fluxes from the C-poor sand and clay soils while it significantly decreased the DOC flux from the organic-rich soil. In contrast, TDN fluxes decreased with biochar additions from all soil types, though the results were not statistically significant from the clay-rich soil. These laboratory experiments suggest that changes in the hydraulic conductivity of soil due to biochar amendments could play a significant role in understanding how biochar additions to agricultural fields will change watershed C and N dynamics. We additionally conducted a 28-day greenhouse experiment with sorghum plants using a three-way factorial treatment (water availability x biochar x mycorrhizae) to

  19. Numerical controlled polishing, continued force wear and part correction experiments

    SciTech Connect

    Hannah, P.R.; Day, R.D.; Hatch, D.J.; McClure, E.R.

    1994-09-01

    This abstract reports the near completion of the first phase of this program. It is the aim of this program to provide the operator of a N/C diamond turning machine or N/C grinding machine (jig grinder) with the wear characteristics necessary to achieve uniform material removal. The second phase of this program addresses a different problem, although solving this problem is highly dependent on the results of the first phase. Diamond turned, or any lathe turned surface, exhibits regular tool marks due to the tool passing over the surface being cut. Changes in depth of cut, feed rate and work rpm will change the character of these groves, but will not eliminate them. Optical surfaces produced by this process exhibit increased scattering as the light wavelength decreases limiting their use; at least for optical purposes, to IR and some visible applications. Utilizing wear information gathered in the first part of this program we will attempt to reduce these residual tool marks by polishing. The polishing of diamond turned surfaces is not new. Diamond turned metal surfaces, especially in electroless nickel and high phosphorus nickel electroplate have been polished to improve their scatter characteristics. What we believe is unique is the use of a spherical wheel, rotating on axis and being moved over the part in a prescribed manner by numerical control. Over the past year we have made some major changes in our polishing methods and procedures. We have listed below these changes, as a refresher for the reader as to our previous procedures. These changes will be addressed in the body of the text.

  20. Overview of CFD Validation Experiments for Circulation Control Applications at NASA

    NASA Technical Reports Server (NTRS)

    Jones, G. S.; Lin, J. C.; Allan, B. G.; Milholen, W. E.; Rumsey, C. L.; Swanson, R. C.

    2008-01-01

    Circulation control is a viable active flow control approach that can be used to meet the NASA Subsonic Fixed Wing project s Cruise Efficient Short Take Off and Landing goals. Currently, circulation control systems are primarily designed using empirical methods. However, large uncertainty in our ability to predict circulation control performance has led to the development of advanced CFD methods. This paper provides an overview of a systematic approach to developing CFD tools for basic and advanced circulation control applications. This four-step approach includes "Unit", "Benchmar", "Subsystem", and "Complete System" experiments. The paper emphasizes the ongoing and planned 2-D and 3-D physics orientated experiments with corresponding CFD efforts. Sample data are used to highlight the challenges involved in conducting circulation control computations and experiments.

  1. The Aqua-Planet Experiment (APE): CONTROL SST Simulation

    NASA Technical Reports Server (NTRS)

    Blackburn, Michael; Williamson, David L.; Nakajima, Kensuke; Ohfuchi, Wataru; Takahashi, Yoshiyuki O.; Hayashi, Yoshi-Yuki; Nakamura, Hisashi; Ishiwatari, Masaki; Mcgregor, John L.; Borth, Hartmut; Wirth, Volkmar; Frank, Helmut; Bechtold, Peter; Wedi, Nils P.; Tomita, Hirofumi; Satoh, Masaki; Zhao, Ming; Held, Isaac M.; Suarez, Max J.; Lee, Myong-In; Watanabe, Masahiro; Kimoto, Masahide; Liu, Yimin; Wang, Zaizhi; Molod, Andrea M.; Rajendran, Kavirajan; Kotoh, Akio; Stratton, Rachel

    2013-01-01

    experimental hierarchy used to evaluate AGCMs. This comparison does suggest that the range of model behaviour could be better understood and reduced in conjunction with Earth climate simulations. Controlled experimentation is required to explore individual model behavior and investigate convergence of the aqua-planet climate with increasing resolution.

  2. Controlling balance during quiet standing: proportional and derivative controller generates preceding motor command to body sway position observed in experiments.

    PubMed

    Masani, Kei; Vette, Albert H; Popovic, Milos R

    2006-02-01

    To compensate for significant time delays in the control of human bipedal stance, it was suggested that a feed-forward control mechanism is needed to generate a preceding motor command to the body sway position observed in quiet standing. In this article, we present evidence that a feedback proportional-derivative (PD) controller can effectively generate a desired preceding motor command. We also discuss the following characteristics of the proposed PD controller: (1) the level of robustness of the controller with respect to neurological time delays and (2) how well the controller replicates the system's dynamics observed in experiments with able bodied subjects, i.e. how well the controller generates the observed preceding motor command. Human quiet stance was simulated using an inverted pendulum model regulated by a PD controller. The simulations were used to calculate the center of mass (COM) position and velocity data, and the motor command (ankle joint torque) data as a function of time. These data and the data obtained in the experiments were compared using cross-correlation functions (CCFs). The results presented herein imply that a PD feedback controller is capable of ensuring balance during human bipedal quiet stance, even if the neurological time delays are considerable. The proposed feedback controller can generate the preceding motor command that was observed in the experiments. Therefore, we conclude that a feed-forward mechanism is not necessary to compensate for the long closed-loop time delay in human bipedal stance as suggested in recent literature, and that the PD controller is a good approximation of the control strategy applied by able bodied subjects during quiet stance. PMID:16399512

  3. Assessing traumatic experiences in screening for PTSD in substance use disorder patients: what is the gain in addition to PTSD symptoms?

    PubMed

    Kok, Tim; de Haan, Hein; van der Meer, Margreet; Najavits, Lisa; de Jong, Cor

    2015-03-30

    Traumatic experiences have been linked with substance use disorders (SUD) and may be an important factor in the perpetuation of SUD, even in the absence of posttraumatic stress disorder (PTSD) symptoms. The purpose of the current study was to examine the relationship between childhood trauma and substance use severity in 192 SUD inpatients. Childhood trauma was assessed using the Traumatic Experiences Checklist (TEC). With variables derived from this measure in addition to PTSD symptoms, two regression models were created with alcohol use or drug use severity as dependent variables. Alcohol severity was explained by PTSD symptoms as well as the age of trauma. Drug severity was explained solely by PTSD symptoms. The clinical value of assessing childhood trauma in determining the addiction severity appears to be limited in comparison with PTSD symptoms. PMID:25687377

  4. Active structural control design and experiment for the Mini-Mast

    NASA Technical Reports Server (NTRS)

    Wie, Bong; Horta, Lucas; Sulla, Jeff

    1990-01-01

    Control system design and closed-loop test results for the Mini-Mast truss structure located at the NASA Langley Research Center are presented. The simplicity and effectiveness of a classical control approach to the active structural control design are demonstrated by ground experiments. The concepts of robust nonminimum phase compensation and periodic disturbance rejection are also experimentally validated. The practicality of a sensor output decoupling approach is demonstrated for the inherent, multivariable control problem of the Mini-Mast.

  5. Canopy Level Solar Induced Fluorescence for Vegetation in Controlled Experiments

    NASA Technical Reports Server (NTRS)

    Middleton, E. M.; Corp, L. A.; Campbell, P. K. Entcheva

    2007-01-01

    Solar induced chlorophyll fluorescence (SIF) was retrieved from high resolution reflectance spectra acquired one meter above saplings of three deciduous tree species during springtime (three weeks after leaf flush) and in late summer when foliage was mature. SIF was determined by application of the Fraunhofer Line Depth (FLD) Principal to above-canopy spectra acquired with an Analytical Spectral Devices (ASD) Fieldspec spectroradiometer (3.2 nm resolution with 1.2 nm sampling interval). SIF retrievals were made at the two atmospheric oxygen (O2) absorption features that occur in the chlorophyll fluorescence (ChlF) region (660 -780 nm). These telluric features are 02V, the broader and deeper feature centered at 760 nm, but located on the shoulder of the far-red ChlF peak at 740 nm; and 023, a narrow feature centered at 688 nm that is positioned near the red ChlF peak at 685 nm. Supporting, coincident leaf level fluorescence, reflectance, photochemical and other measurements were also made. At the leaf level, these measurements included in situ photosynthetic capacity (Pmax) and light adapted total chlorophyll fluorescence (Fs') collected at steady state under high light and controlled chamber conditions (e.g., temperature, PAR, humidity, and COz); optical properties (reflectance, transmittance, absorptance); chlorophyll and carotenoid content; specific leaf mass; carbon (C) and nitrogen (N) content; fluorescence emission spectra at multiple excitation wavelengths; the ChlF contribution to red (R) and far-red (FR) reflectance; fluorescence imagery; and fluorescence excitation-emission matrices (EEMs). The tree species examined were tulip poplar (Liriodendron tulipifera L.), red maple (Acer rubrum L.), and sweetgum (Liquidambar styraczflua L.), and each had been provided four levels of N augmentation (0, 19, 37, and 75 kg Nhectare seasonally) to simulate atmospheric deposition from air pollution. Whole-plant SIF measurements of these species were compared with SIF

  6. Response of aboveground biomass and diversity to nitrogen addition – a five-year experiment in semi-arid grassland of Inner Mongolia, China

    PubMed Central

    He, Kejian; Qi, Yu; Huang, Yongmei; Chen, Huiying; Sheng, Zhilu; Xu, Xia; Duan, Lei

    2016-01-01

    Understanding the response of the plant community to increasing nitrogen (N) deposition is helpful for improving pasture management in semi-arid areas. We implemented a 5-year N addition experiment in a Stipa krylovii steppe of Inner Mongolia, northern China. The aboveground biomass (AGB) and species richness were measured annually. Along with the N addition levels, the species richness declined significantly, and the species composition changed noticeably. However, the total AGB did not exhibit a noticeable increase. We found that compensatory effects of the AGB occurred not only between the grasses and the forbs but also among Gramineae species. The plant responses to N addition, from the community to species level, lessened in dry years compared to wet or normal years. The N addition intensified the reduction of community productivity in dry years. Our study indicated that the compensatory effects of the AGB among the species sustained the stability of grassland productivity. However, biodiversity loss resulting from increasing N deposition might lead the semi-arid grassland ecosystem to be unsustainable, especially in dry years. PMID:27573360

  7. Response of aboveground biomass and diversity to nitrogen addition - a five-year experiment in semi-arid grassland of Inner Mongolia, China.

    PubMed

    He, Kejian; Qi, Yu; Huang, Yongmei; Chen, Huiying; Sheng, Zhilu; Xu, Xia; Duan, Lei

    2016-01-01

    Understanding the response of the plant community to increasing nitrogen (N) deposition is helpful for improving pasture management in semi-arid areas. We implemented a 5-year N addition experiment in a Stipa krylovii steppe of Inner Mongolia, northern China. The aboveground biomass (AGB) and species richness were measured annually. Along with the N addition levels, the species richness declined significantly, and the species composition changed noticeably. However, the total AGB did not exhibit a noticeable increase. We found that compensatory effects of the AGB occurred not only between the grasses and the forbs but also among Gramineae species. The plant responses to N addition, from the community to species level, lessened in dry years compared to wet or normal years. The N addition intensified the reduction of community productivity in dry years. Our study indicated that the compensatory effects of the AGB among the species sustained the stability of grassland productivity. However, biodiversity loss resulting from increasing N deposition might lead the semi-arid grassland ecosystem to be unsustainable, especially in dry years. PMID:27573360

  8. A negative association between video game experience and proactive cognitive control.

    PubMed

    Bailey, Kira; West, Robert; Anderson, Craig A

    2010-01-01

    Some evidence demonstrates that video game experience has a beneficial effect on visuospatial cognition. In contrast, other evidence indicates that video game experience may be negatively related to cognitive control. In this study we examined the specificity of the influence of video game experience on cognitive control. Participants with high and low video game experience performed the Stroop task while event-related brain potentials were recorded. The behavioral data revealed no difference between high and low gamers for the Stroop interference effect and a reduction in the conflict adaptation effect in high gamers. The amplitude of the medial frontal negativity and a frontal slow wave was attenuated in high gamers, and there was no effect of gaming status on the conflict slow potential. These data lead to the suggestion that video game experience has a negative influence on proactive, but not reactive, cognitive control. PMID:19818048

  9. Resist Profile Control Obtained Through A Desirability Function And Statistically Designed Experiments

    NASA Astrophysics Data System (ADS)

    Bell, Kenneth L.; Christensen, Lorna D.

    1989-07-01

    This paper describes a technique used to determine an optimized microlithographic process using statistical methods which included a statistically designed experiment (SDE); a desirability function, d(θ*) and a rigorous daily statistical process control program, (SPC).

  10. Effects of a Structured Camp Experience on Locus of Control Orientation

    ERIC Educational Resources Information Center

    Nowicki, Stephen, Jr.; Barnes, Jarvis

    1973-01-01

    Inner-city teenagers experienced a structured camp program for a week. It was predicted and found that this experience led to a change toward internality, in the locus of control orientation of these youngsters. (Authors)

  11. User's Guide for ERB 7 Matrix. Volume 1: Experiment Description and Quality Control Report for Year 1

    NASA Technical Reports Server (NTRS)

    Tighe, R. J.; Shen, M. Y. H.

    1984-01-01

    The Nimbus 7 ERB MATRIX Tape is a computer program in which radiances and irradiances are converted into fluxes which are used to compute the basic scientific output parameters, emitted flux, albedo, and net radiation. They are spatially averaged and presented as time averages over one-day, six-day, and monthly periods. MATRIX data for the period November 16, 1978 through October 31, 1979 are presented. Described are the Earth Radiation Budget experiment, the Science Quality Control Report, Items checked by the MATRIX Science Quality Control Program, and Science Quality Control Data Analysis Report. Additional material from the detailed scientific quality control of the tapes which may be very useful to a user of the MATRIX tapes is included. Known errors and data problems and some suggestions on how to use the data for further climatologic and atmospheric physics studies are also discussed.

  12. An application of the IMC software to controller design for the JPL LSCL Experiment Facility

    NASA Technical Reports Server (NTRS)

    Zhu, Guoming; Skelton, Robert E.

    1993-01-01

    A software package which Integrates Model reduction and Controller design (The IMC software) is applied to design controllers for the JPL Large Spacecraft Control Laboratory Experiment Facility. Modal Cost Analysis is used for the model reduction, and various Output Covariance Constraints are guaranteed by the controller design. The main motivation is to find the controller with the 'best' performance with respect to output variances. Indeed it is shown that by iterating on the reduced order design model, the controller designed does have better performance than that obtained with the first model reduction.

  13. The human operator in manual preview tracking /an experiment and its modeling via optimal control/

    NASA Technical Reports Server (NTRS)

    Tomizuka, M.; Whitney, D. E.

    1976-01-01

    A manual preview tracking experiment and its results are presented. The preview drastically improves the tracking performance compared to zero-preview tracking. Optimal discrete finite preview control is applied to determine the structure of a mathematical model of the manual preview tracking experiment. Variable parameters in the model are adjusted to values which are consistent to the published data in manual control. The model with the adjusted parameters is found to be well correlated to the experimental results.

  14. Development and Evaluation of Sequential Control Educational Materials with Module Structure for Engineering Experiments

    NASA Astrophysics Data System (ADS)

    Inamori, Sakae; Chida, Kazunori; Noguchi, Takafumi; Arai, Makoto; Koshimizu, Makoto

    We have developed educational materials to learn about sequential control technology for engineering students. The educational materials have use-friendly characteristics and high-visibility. The characteristics are based on Keller's ARCS model of motivation. At the end of experiments, a questionnaire about these educational materials was administered to the students. The analysis of the questionnaire showed that most students achieved a good understanding and were very interested in experiments of sequential control.

  15. F-16XL-2 Supersonic Laminar Flow Control Flight Test Experiment

    NASA Technical Reports Server (NTRS)

    Anders, Scott G.; Fischer, Michael C.

    1999-01-01

    The F-16XL-2 Supersonic Laminar Flow Control Flight Test Experiment was part of the NASA High-Speed Research Program. The goal of the experiment was to demonstrate extensive laminar flow, to validate computational fluid dynamics (CFD) codes and design methodology, and to establish laminar flow control design criteria. Topics include the flight test hardware and design, airplane modification, the pressure and suction distributions achieved, the laminar flow achieved, and the data analysis and code correlation.

  16. Elemental and Isotopic Incorporation into the Aragonitic Shells of Arctica Islandica: Insights from Temperature Controlled Experiments

    NASA Astrophysics Data System (ADS)

    Wanamaker, A. D.; Gillikin, D. P.

    2014-12-01

    The long-lived ocean quahog, Arctica islandica, is a fairly well developed and tested marine proxy archive, however, the utility of elemental ratios in A. islandica shell material as environmental proxies remains questionable. To further evaluate the influence of seawater temperature on elemental and isotopic incorporation during biomineralization, A. islandica shells were grown at constant temperatures under two regimes during a 16-week period from March 27 to July 21, 2011. Seawater from the Darling Marine Center in Walpole, Maine was pumped into temperature and flow controlled tanks that were exposed to ambient food and salinity conditions. A total of 20 individual juvenile clams with an average shell height of 36 mm were stained with calcein (a commonly used biomarker) and cultured at 10.3 ± 0.3 °C for six weeks. After this, shell heights were measured and the clams were again stained with calcein and cultured at 15.0 ± 0.4 °C for an additional 9.5 weeks. The average shell growth during the first phase of the experiment was 2.4 mm with a linear extension rate of 0.40 mm/week. The average shell growth during the second phase of the experiment was 3.2 mm with an extension rate of 0.34 mm/week. Average salinity values were 30.2 ± 0.7 and 30.7 ±0.7 in the first and second phases of the experiment, respectively. Oxygen isotopes from the cultured seawater were collected throughout the experiment and provide the basis for establishing if shells grew in oxygen isotopic equilibrium. Elemental ratios (primarily Ba/Ca, Mg/Ca, Sr/Ca) in the aragonitic shells were determined via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), while stable oxygen and carbon isotope ratios were measured using continuous flow isotope ratio mass spectrometry. Continuous sampling within and across the temperature conditions (from 10 °C to 15 °C) coupled with the calcein markings provides the ability to place each sample into a precise temporal framework. The

  17. Viewing Artworks: Contributions of Cognitive Control and Perceptual Facilitation to Aesthetic Experience

    ERIC Educational Resources Information Center

    Cupchik, Gerald C.; Vartanian, Oshin; Crawley, Adrian; Mikulis, David J.

    2009-01-01

    When we view visual images in everyday life, our perception is oriented toward object identification. In contrast, when viewing visual images "as artworks", we also tend to experience subjective reactions to their stylistic and structural properties. This experiment sought to determine how cognitive control and perceptual facilitation contribute…

  18. Development of Skylab experiment T020 employing a foot controlled maneuvering unit

    NASA Technical Reports Server (NTRS)

    Hewes, D. E.; Glover, K. E.

    1972-01-01

    A review of the plans and preparations is presented for Skylab experiment T020, entitled Foot-Controlled Maneuvering Unit (FCMU). The FCMU is an experimental system intended to explore the use of simple astronaut maneuvering devices in the zero-gravity environment of space. This review also includes discussions of the FCMU concept and experiment hardware systems, as well as supporting experiment definition and development research studies conducted with the aid of zero-gravity simulators.

  19. Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 3 Full-scale Test Results

    SciTech Connect

    Gary Blythe

    2007-05-01

    This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of a flue gas desulfurization (FGD) additive, Degussa Corporation's TMT-15, to prevent the reemission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine TMT salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project is conducting pilot- and full-scale tests of the TMT-15 additive in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} reemissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Power River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, TXU Generation Company LP, Southern Company, and Degussa Corporation. TXU Generation has provided the Texas lignite/PRB cofired test site for pilot FGD tests, Monticello Steam Electric Station Unit 3. Southern Company is providing the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems to be tested. IPL, an AES company, provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Degussa Corporation is providing the TMT-15 additive and technical support to the test program as cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing

  20. Previous experience with behavioral control over stress blocks the behavioral and dorsal raphe nucleus activating effects of later uncontrollable stress: role of the ventral medial prefrontal cortex.

    PubMed

    Amat, José; Paul, Evan; Zarza, Christina; Watkins, Linda R; Maier, Steven F

    2006-12-20

    Previous experience with stressors over which the subject has behavioral control blocks the typical behavioral consequences of subsequent exposure to stressors over which the organism has no behavioral control. The present experiments explored the involvement of the ventral medial prefrontal cortex (mPFCv) in mediating this "immunizing" or resilience producing effect of an initial experience with control. Behavioral immunization was blocked by inactivation of the mPFCv with muscimol at the time of the initial experience with control, as well as at the time of the later exposure to uncontrollable stress. Inhibition of protein synthesis within the mPFCv by anisomycin also blocked immunization when administered at the time of the initial controllable stress but had no effect when administered at the time of the later uncontrollable stress. Additional experiments found that the initial experience with control blocks the intense activation of serotonergic cells in the dorsal raphe nucleus that would normally be produced by uncontrollable stress, providing a mechanism for behavioral immunization. Furthermore, mPFCv activity during the initial controllable stressor was required for this effect to occur. These results suggest that the mPFCv is needed both to process information about the controllability of stressors and to utilize such information to regulate responses to subsequent stressors. Moreover, the mPFCv may be a site of storage or plasticity concerning controllability information. These results are consistent with recent research in other domains that explore the functions of the mPFCv. PMID:17182776

  1. Further Characterization of 394-GHz Gyrotron FU CW GII with Additional PID Control System for 600-MHz DNP-SSNMR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ueda, Keisuke; Matsuki, Yoh; Fujiwara, Toshimichi; Tatematsu, Yoshinori; Ogawa, Isamu; Idehara, Toshitaka

    2016-09-01

    A 394-GHz gyrotron, FU CW GII, has been designed at the University of Fukui, Japan, for dynamic nuclear polarization (DNP)-enhanced solid-state nuclear magnetic resonance (SSNMR) experiments at 600-MHz 1H resonant frequency. After installation at the Institute for Protein Research (IPR), Osaka University, Japan, a PID feedback control system was equipped to regulate the electron gun heater current for stabilization of the electron beam current, which ultimately achieved stabilization of output power when operating in continuous wave (CW) mode. During exploration to further optimize operating conditions, a continuous tuning bandwidth of approximately 1 GHz was observed by varying the operating voltage at a fixed magnetic field. In the frequency range required for positive DNP enhancement, the output power was improved by increasing the magnetic field and the operating voltage from their initial operational settings. In addition, fine tuning of output frequency by varying the cavity cooling water temperature was demonstrated. These operating conditions and ancillary enhancements are expected to contribute to further enhancement of SSNMR signal.

  2. Further Characterization of 394-GHz Gyrotron FU CW GII with Additional PID Control System for 600-MHz DNP-SSNMR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ueda, Keisuke; Matsuki, Yoh; Fujiwara, Toshimichi; Tatematsu, Yoshinori; Ogawa, Isamu; Idehara, Toshitaka

    2016-04-01

    A 394-GHz gyrotron, FU CW GII, has been designed at the University of Fukui, Japan, for dynamic nuclear polarization (DNP)-enhanced solid-state nuclear magnetic resonance (SSNMR) experiments at 600-MHz 1H resonant frequency. After installation at the Institute for Protein Research (IPR), Osaka University, Japan, a PID feedback control system was equipped to regulate the electron gun heater current for stabilization of the electron beam current, which ultimately achieved stabilization of output power when operating in continuous wave (CW) mode. During exploration to further optimize operating conditions, a continuous tuning bandwidth of approximately 1 GHz was observed by varying the operating voltage at a fixed magnetic field. In the frequency range required for positive DNP enhancement, the output power was improved by increasing the magnetic field and the operating voltage from their initial operational settings. In addition, fine tuning of output frequency by varying the cavity cooling water temperature was demonstrated. These operating conditions and ancillary enhancements are expected to contribute to further enhancement of SSNMR signal.

  3. Quality control and assurance program for duplex stainless steels, field experience

    SciTech Connect

    Mekhjian, M.; Richard, D.; Nemzer, A.

    1994-12-31

    Duplex stainless steels have proven to be cost effective alternatives to more highly alloyed materials in chloride environments in which conventional 300 series austenitic stainless steels suffer from stress corrosion cracking. However, improper welding of these alloys can cause significant reduction in their corrosion resistance. Close monitoring of welding during fabrication and tight quality control is necessary to ensure that sound weld metal microstructure is obtained with optimum corrosion resistance. One of FMC`s primary applications for duplex stainless steels has been in large scrubbers units in chemical processing plants. In the fabrication of these scrubbers, training of the fabricators and welders was necessary as a part of the total quality control and assurance program. Corrosion testing was performed on coupons removed from each welding procedure qualification test plate and from run-off tabs removed from production welds. The corrosion tests were performed in ferric chloride. Although ferric chloride is not a realistic service environment for these alloys, it has been widely used for screening purposes and successfully indicates the presence of undesirable microstructures. Two deposited weld microstructures were identified as being most susceptible to pitting in the samples examined. These were areas with high ferrite containing precipitates and reheated areas of multiple pass welds with a high secondary austenite content. Field experience showed that relying only on monitoring and controlling the welding heat input, preheat and interpass temperatures, may not be sufficient for ensuring the corrosion resistance of the finished weldment and additional corrosion testing should be done. The materials tested were weldments of alloy 2205 (UNS S31803) and alloy 255 (LTNS S32550).

  4. Child Effortful Control, Teacher-Student Relationships, and Achievement in Academically At-Risk Children: Additive and Interactive Effects

    ERIC Educational Resources Information Center

    Liew, Jeffrey; Chen, Qi; Hughes, Jan N.

    2010-01-01

    The joint contributions of child effortful control (using inhibitory control and task accuracy as behavioral indices) and positive teacher-student relationships at first grade on reading and mathematics achievement at second grade were examined in 761 children who were predominantly from low-income and ethnic minority backgrounds and assessed to…

  5. Cancer Control Research Training for Native Researchers: A Model for Development of Additional Native Researcher Training Programs

    ERIC Educational Resources Information Center

    Becker, Thomas M.; Dunn, Esther; Tom-Orme, Lillian; Joe, Jennie

    2005-01-01

    Several social and biological scientists who have Native status are engaged in productive research careers, but the encouragement that has been offered to Native students to formulate career goals devoted to cancer etiology or cancer control in Native peoples has had limited success. Hence, the Native Researchers' Cancer Control Training Program…

  6. Integrated Autopilot/Autothrottle Based on a Total Energy Control Concept: Design and Evaluation of Additional Autopilot Modes

    NASA Technical Reports Server (NTRS)

    Bruce, Kevin R.

    1988-01-01

    An integrated autopilot/autothrottle system was designed using a total energy control design philosophy. This design ensures that the system can differentiate between maneuvers requiring a change in thrust to accomplish a net energy change, and those maneuvers which only require elevator control to redistribute energy. The system design, the development of the system, and a summary of simulation results are defined.

  7. Preservice Students' Attitudes toward Pupil Control as They Develop throughout the Field Experiences.

    ERIC Educational Resources Information Center

    Killian, Joyce E.; McIntyre, D. John

    This study used repeated measures of the Pupil Control Ideology (PCI) instrument to examine the change in student teacher orientation toward pupil control ideology occurring during a three semester field experience. The instrument was given to elementary and secondary education majors at Southern Illinois University at Carbondale five different…

  8. Action-Control Beliefs and School Experiences of Tanzanian Primary School Students.

    ERIC Educational Resources Information Center

    Malmberg, Lars-Erik; Wanner, Brigitte; Sumra, Suleman; Little, Todd D.

    2001-01-01

    Investigated urban and rural Tanzanian elementary students' experiences and action-control beliefs about school performance using the revised Control, Agency, and Means-End Interview. Student surveys indicated that the Tanzanian educational system and teaching format were reflected in low performance-belief relationships. High achievers were more…

  9. Student Experiments for Investigations of Physical Controls on Viscosity and the Implications for Volcanic Hazards

    NASA Astrophysics Data System (ADS)

    Edwards, B. R.; Teasdale, R.; Myers, J.

    2003-12-01

    Interactive laboratory investigations and demonstrations using analog materials can be used to introduce students to the rheologic properties of magmas and lavas. Using such an approach, students investigate the physical, compositional, and thermodynamic controls on viscosity through observations, experimental investigations, calculations, and computer simulations. During lab exercises, which are typically preceded by a reading assignment and brief introduction, students use analog materials (e.g. corn syrup) to experiment with parameters controlling viscosity. They prepare a set of syrup solutions at 3 (or more) temperatures, another set of syrup solutions with varying proportions of particles (e.g. sand), and a final set of syrup solutions mixed with water. A fourth experiment, which produces somewhat more complex results, can be prepared by using a hand mixer to make syrup with varying proportions of bubbles. Students make qualitative observations of the relative force required to blow bubbles into the syrup solutions with a straw as an analog for comparing the effects of viscosity on the formation and bursting behavior of gas bubbles in magma. During class, students observe syrup "lava flows" flowing on a slope. Measured flow characteristics are used to calculate viscosities for each "lava" using a dynamic visual equation (DVE) of the Jeffries equation. The DVE, which was created in Flash MX, allows students to explore interactively and visually how changing various parameters in the Jeffries equation affects fluid viscosity. Before each experiment, a critical set of questions lead students to make predictions and hone their observational skills. The questions also help students generate graphs and sketches and write brief reports to synthesize their observations. Additional activities incorporating volcanic hazards associated with low versus high viscosity flows and highly viscous explosive eruptions bring students back to very real applications of the

  10. Flexible structure control experiments using a real-time workstation for computer-aided control engineering

    NASA Technical Reports Server (NTRS)

    Stieber, Michael E.

    1989-01-01

    A Real-Time Workstation for Computer-Aided Control Engineering has been developed jointly by the Communications Research Centre (CRC) and Ruhr-Universitaet Bochum (RUB), West Germany. The system is presently used for the development and experimental verification of control techniques for large space systems with significant structural flexibility. The Real-Time Workstation essentially is an implementation of RUB's extensive Computer-Aided Control Engineering package KEDDC on an INTEL micro-computer running under the RMS real-time operating system. The portable system supports system identification, analysis, control design and simulation, as well as the immediate implementation and test of control systems. The Real-Time Workstation is currently being used by CRC to study control/structure interaction on a ground-based structure called DAISY, whose design was inspired by a reflector antenna. DAISY emulates the dynamics of a large flexible spacecraft with the following characteristics: rigid body modes, many clustered vibration modes with low frequencies and extremely low damping. The Real-Time Workstation was found to be a very powerful tool for experimental studies, supporting control design and simulation, and conducting and evaluating tests withn one integrated environment.

  11. Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 5 Full-Scale Test Results

    SciTech Connect

    Gary Blythe; MariJon Owens

    2007-12-01

    This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project is conducting pilot- and full-scale tests of the additives in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power has provided the Texas lignite/PRB co-fired test site for pilot FGD tests and cost sharing. Southern Company has provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation is providing the TMT-15 additive, and the Nalco Company is providing the Nalco 8034 additive. Both companies are also supplying technical support to the test program as in-kind cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management

  12. Saccharomyces cerevisiae Thg1 Uses 5′-Pyrophosphate Removal To Control Addition of Nucleotides to tRNAHis

    PubMed Central

    2015-01-01

    In eukaryotes, the tRNAHis guanylyltransferase (Thg1) catalyzes 3′–5′ addition of a single guanosine residue to the −1 position (G–1) of tRNAHis, across from a highly conserved adenosine at position 73 (A73). After addition of G–1, Thg1 removes pyrophosphate from the tRNA 5′-end, generating 5′-monophosphorylated G–1-containing tRNA. The presence of the 5′-monophosphorylated G–1 residue is important for recognition of tRNAHis by its cognate histidyl-tRNA synthetase. In addition to the single-G–1 addition reaction, Thg1 polymerizes multiple G residues to the 5′-end of tRNAHis variants. For 3′–5′ polymerization, Thg1 uses the 3′-end of the tRNAHis acceptor stem as a template. The mechanism of reverse polymerization is presumed to involve nucleophilic attack of the 3′-OH from each incoming NTP on the intact 5′-triphosphate created by the preceding nucleotide addition. The potential exists for competition between 5′-pyrophosphate removal and 3′–5′ polymerase reactions that could define the outcome of Thg1-catalyzed addition, yet the interplay between these competing reactions has not been investigated for any Thg1 enzyme. Here we establish transient kinetic assays to characterize the pyrophosphate removal versus nucleotide addition activities of yeast Thg1 with a set of tRNAHis substrates in which the identity of the N–1:N73 base pair was varied to mimic various products of the N–1 addition reaction catalyzed by Thg1. We demonstrate that retention of the 5′-triphosphate is correlated with efficient 3′–5′ reverse polymerization. A kinetic partitioning mechanism that acts to prevent addition of nucleotides beyond the −1 position with wild-type tRNAHis is proposed. PMID:24548272

  13. Design rules for rational control of polymer glass formation behavior and mechanical properties with small molecular additives

    NASA Astrophysics Data System (ADS)

    Mangalara, Jayachandra Hari; Simmons, David

    Small molecule additives have long been employed to tune polymers' glass formation, mechanical and transport properties. For example, plasticizers are commonly employed to suppress polymer Tg and soften the glassy state, while antiplasticizers, which stiffen the glassy state of a polymer while suppressing its Tg, are employed to enhance protein and tissue preservation in sugar glasses. Recent literature indicates that additives can have a wide range of possible effects, but all of these have not been clearly understood and well appreciated. Here we employ molecular dynamics simulations to establish design rules for the selection of small molecule additives with size, molecular stiffness, and interaction energy chosen to achieve targeted effects on polymer properties. We furthermore find that a given additive's effect on a polymer's Tg can be predicted from its Debye-Waller factor via a function previously found to describe nanoconfinement effects on the glass transition. These results emphasize the potential for a new generation of targeted molecular additives to contribute to more targeted rational design of polymers. We acknowledge the Keck Foundation and the Ohio Supercomputing Center for financial and computational support of this effort, respectively.

  14. 40 CFR 82.18 - Availability of production in addition to baseline production allowances for class II controlled...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... permitted under the Montreal Protocol or to receive from the person for the current control period some... production quantities: (A) The maximum production that the nation is allowed under the Protocol minus...

  15. Birth control sabotage and forced sex: experiences reported by women in domestic violence shelters.

    PubMed

    Thiel de Bocanegra, Heike; Rostovtseva, Daria P; Khera, Satin; Godhwani, Nita

    2010-05-01

    Women who experience intimate partner violence often experience birth control sabotage, forced sex, and partner's unwillingness to use condoms. We interviewed 53 women at four domestic violence shelters. Participants reported that their abusive partners frequently refused to use condoms, impeded them from accessing health care, and subjected them to birth control sabotage, infidelity, and forced sex. However, women also reported strategies to counteract these actions, particularly against birth control sabotage and attempts to force them to abort or continue a pregnancy. Domestic violence counselors can focus on these successful strategies to validate coping skills and build self-esteem. PMID:20388933

  16. Geo-engineering experiments in two urban ponds to control eutrophication.

    PubMed

    Waajen, Guido; van Oosterhout, Frank; Douglas, Grant; Lürling, Miquel

    2016-06-15

    Many urban ponds experience detrimental algal blooms as the result of eutrophication. During a two year field experiment, the efficacy of five in situ treatments to mitigate eutrophication effects in urban ponds was studied. The treatments targeted the sediment phosphorus release and were intended to switch the ponds from a turbid phytoplankton-dominated state to a clear-water state with a low phytoplankton biomass. Two eutrophic urban ponds were each divided into six compartments (300-400 m(2); 210-700 m(3)). In each pond the following treatments were tested: dredging in combination with biomanipulation (involving fish biomass control and the introduction of macrophytes) with and without the addition of the flocculant polyaluminiumchloride, interception and reduction of sediment phosphorus release with lanthanum-modified bentonite (Phoslock(®)) in combination with biomanipulation with and without polyaluminiumchloride; biomanipulation alone; and a control. Trial results support the hypothesis that the combination of biomanipulation and measures targeting the sediment phosphorus release can be effective in reducing the phytoplankton biomass and establishing and maintaining a clear-water state, provided the external phosphorus loading is limited. During the experimental period dredging combined with biomanipulation showed mean chlorophyll-a concentrations of 5.3 and 6.2 μg L(-1), compared to 268.9 and 52.4 μg L(-1) in the control compartments. Lanthanum-modified bentonite can be an effective alternative to dredging and in combination with biomanipulation it showed mean chlorophyll-a concentrations of 5.9 and 7.6 μg L(-1). Biomanipulation alone did not establish a clear-water state or only during a limited period. As the two experimental sites differed in their reaction to the treatments, it is important to choose the most promising treatment depending on site specific characteristics. In recovering the water quality status of urban ponds, continuing

  17. CSM digital autopilot testing in support of ASTP experiments control requirements

    NASA Technical Reports Server (NTRS)

    Rue, D. L.

    1975-01-01

    Results are presented of CSM digital autopilot (DAP) testing. The testing was performed to demonstrate and evaluate control modes which are currently planned or could be considered for use in support of experiments on the ASTP mission. The testing was performed on the Lockheed Guidance, Navigation, and Control System Functional Simulator (GNCFS). This simulator, which was designed to test the Apollo and Skylab DAP control system, has been used extensively and is a proven tool for CSM DAP analysis.

  18. Apollo experience report: Guidance and control systems: Automated control system for unmanned mission AS-201

    NASA Technical Reports Server (NTRS)

    Holloway, G. F.

    1975-01-01

    The Apollo command module heat shield and Apollo command and service module/Saturn launch vehicle structural integrity were evaluated in an unmanned test flight. An automated control system was developed to provide the mission event sequencing, the real-time ground control interface, and the backup attitude reference system for the unmanned flight. The required mission events, the design logic, the redundancy concept, and the ground-support-equipment concept are described and some development problem areas are discussed. The mission event time line and the real-time ground command list are included to provide an outline of the control system capabilities and requirements. The mission was accomplished with the automated control system, which functioned without flight anomalies.

  19. Construction of AC Motor Controllers for NOvA Experiment Upgrades

    SciTech Connect

    Cooley, Patrick; /Fermilab

    2011-08-04

    I have been constructing Alternating Current (AC) motor controllers for manipulation of particle beam detectors. The capability and reliability of these motor controllers are essential to the Laboratory's mission of accurate analysis of the particle beam's position. The device is moved in and out of the beam's path by the motor controller followed by the Neutrinos at the Main Injector Off-Axis {nu}{sub e} Appearance (NOvA) Experiment further down the beam pipe. In total, I built and tested ten ac motor controllers for new beam operations in the NOvA experiment. These units will prove to be durable and provide extremely accurate beam placement for NOvA Experiment far into the future.

  20. Effects of eye movement desensitization and reprocessing (EMDR) on non-specific chronic back pain: a randomized controlled trial with additional exploration of the underlying mechanisms

    PubMed Central

    2013-01-01

    Background Non-specific chronic back pain (CBP) is often accompanied by psychological trauma, but treatment for this associated condition is often insufficient. Nevertheless, despite the common co-occurrence of pain and psychological trauma, a specific trauma-focused approach for treating CBP has been neglected to date. Accordingly, eye movement desensitization and reprocessing (EMDR), originally developed as a treatment approach for posttraumatic stress disorders, is a promising approach for treating CBP in patients who have experienced psychological trauma. Thus, the aim of this study is to determine whether a standardized, short-term EMDR intervention added to treatment as usual (TAU) reduces pain intensity in CBP patients with psychological trauma vs. TAU alone. Methods/design The study will recruit 40 non-specific CBP patients who have experienced psychological trauma. After a baseline assessment, the patients will be randomized to either an intervention group (n = 20) or a control group (n = 20). Individuals in the EMDR group will receive ten 90-minute sessions of EMDR fortnightly in addition to TAU. The control group will receive TAU alone. The post-treatment assessments will take place two weeks after the last EMDR session and six months later. The primary outcome will be the change in the intensity of CBP within the last four weeks (numeric rating scale 0–10) from the pre-treatment assessment to the post-treatment assessment two weeks after the completion of treatment. In addition, the patients will undergo a thorough assessment of the change in the experience of pain, disability, trauma-associated distress, mental co-morbidities, resilience, and quality of life to explore distinct treatment effects. To explore the mechanisms of action that are involved, changes in pain perception and pain processing (quantitative sensory testing, conditioned pain modulation) will also be assessed. The statistical analysis of the primary outcome will be performed