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Sample records for stabilized highly odorous

  1. Odorants and malodors associated with land application of biosolids stabilized with lime and coal fly ash.

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    Laor, Yael; Naor, Moshe; Ravid, Uzi; Fine, Pinchas; Halachmi, Ilan; Chen, Yona; Baybikov, Rima

    2011-01-01

    Malodor emissions limit public acceptance of using municipal biosolids as natural organic resources in agricultural production. We aimed to identify major odorants and to evaluate odor concentrations associated with land application of anaerobically digested sewage sludges (Class B) and their alkaline (lime and coal fly ash)-stabilized products (Class A). These two types of biosolids were applied at 12.6 tonnes ha(-1) (dry weight) to microplots of very fine clayey Vertisol in the Jezreel Valley, northern Israel. The volatile organic compounds (VOCs) emitted from the biosolids before and during alkaline stabilization and after incorporation into the soil were analyzed by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry. Odor concentrations at the plots were evaluated on site with a Nasal Ranger field olfactometer that sniffed over a defined land surface area through a static chamber. The odors emitted by anaerobically digested sewage sludges from three activated sludge water treatment plants had one characteristic chemical fingerprint. Alkaline stabilization emitted substantial odors associated with high concentrations of ammonia and release of nitrogen-containing VOCs and did not effectively reduce the potential odor annoyance. Odorous VOCs could be generated within the soil after biosolids incorporation, presumably because of anaerobic conditions within soil-biosolids aggregates. We propose that dimethyl disulfide and dimethyl trisulfide, which seem to be most related to the odor concentrations of biosolids-treated soil, be used as potential chemical markers for the odor annoyance associated with incorporation of anaerobically digested sewage sludges. by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. Three dopamine pathways induce aversive odor memories with different stability.

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    Yoshinori Aso

    Full Text Available Animals acquire predictive values of sensory stimuli through reinforcement. In the brain of Drosophila melanogaster, activation of two types of dopamine neurons in the PAM and PPL1 clusters has been shown to induce aversive odor memory. Here, we identified the third cell type and characterized aversive memories induced by these dopamine neurons. These three dopamine pathways all project to the mushroom body but terminate in the spatially segregated subdomains. To understand the functional difference of these dopamine pathways in electric shock reinforcement, we blocked each one of them during memory acquisition. We found that all three pathways partially contribute to electric shock memory. Notably, the memories mediated by these neurons differed in temporal stability. Furthermore, combinatorial activation of two of these pathways revealed significant interaction of individual memory components rather than their simple summation. These results cast light on a cellular mechanism by which a noxious event induces different dopamine signals to a single brain structure to synthesize an aversive memory.

  3. Stability of odorants from pig production in sampling bags for olfactometry.

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    Hansen, Michael J; Adamsen, Anders P S; Feilberg, Anders; Jonassen, Kristoffer E N

    2011-01-01

    Odor from pig production facilities is typically measured with olfactometry, whereby odor samples are collected in sampling bags and assessed by human panelists within 30 h. In the present study, the storage stability of odorants in two types of sampling bags that are often used for olfactometry was investigated. The bags were made of Tedlar or Nalophan. In a field experiment, humid and dried air samples were collected from a pig production facility with growing-finishing pigs and analyzed with a gas chromatograph with an amperometric sulfur detector at 4, 8, 12, 28, 52, and 76 h after sampling. In a laboratory experiment, the bags were filled with a humid gas mixture containing carboxylic acids, phenols, indoles, and sulfur compounds and analyzed with proton-transfer-reaction mass spectrometry after 0, 4, 8, 12, and 24 h. The results demonstrated that the concentrations of carboxylic acids, phenols, and indoles decreased by 50 to >99% during the 24 h of storage in Tedlar and Nalophan bags. The concentration of hydrogen sulfide decreased by approximately 30% during the 24 h of storage in Nalophan bags, whereas in Tedlar bags the concentration of sulfur compounds decreased by bags, and the composition changes toward a higher relative presence of sulfur compounds. This can result in underestimation of odor emissions from pig production facilities and of the effect of odor reduction technologies. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  4. Odor memory stability after reinnervation of the olfactory bulb.

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    Eduardo Blanco-Hernández

    Full Text Available The olfactory system, particularly the olfactory epithelium, presents a unique opportunity to study the regenerative capabilities of the brain, because of its ability to recover after damage. In this study, we ablated olfactory sensory neurons with methimazole and followed the anatomical and functional recovery of circuits expressing genetic markers for I7 and M72 receptors (M72-IRES-tau-LacZ and I7-IRES-tau-GFP. Our results show that 45 days after methimazole-induced lesion, axonal projections to the bulb of M72 and I7 populations are largely reestablished. Furthermore, regenerated glomeruli are re-formed within the same areas as those of control, unexposed mice. This anatomical regeneration correlates with functional recovery of a previously learned odorant-discrimination task, dependent on the cognate ligands for M72 and I7. Following regeneration, mice also recover innate responsiveness to TMT and urine. Our findings show that regeneration of neuronal circuits in the olfactory system can be achieved with remarkable precision and underscore the importance of glomerular organization to evoke memory traces stored in the brain.

  5. No effect of odor-induced memory reactivation during REM sleep on declarative memory stability

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    Maren Jasmin Cordi

    2014-09-01

    Full Text Available Memory reactivations in hippocampal brain areas are critically involved in memory consolidation processes during sleep. In particular, specific firing patterns of hippocampal place cells observed during learning are replayed during subsequent sleep and rest in rodents. In humans, experimentally inducing hippocampal memory reactivations during slow-wave sleep (but not during wakefulness benefits consolidation and immediately stabilizes declarative memories against future interference. Importantly, spontaneous hippocampal replay activity can also be observed during rapid-eye movement (REM sleep and some authors have suggested that replay during REM sleep is related to processes of memory consolidation. However, the functional role of reactivations during REM sleep for memory stability is still unclear. Here, we reactivated memories during REM sleep and examined its consequences for the stability of declarative memories. After three hours of early, slow-wave sleep (SWS rich sleep, 16 healthy young adults learned a 2-D object location task in the presence of a contextual odor. During subsequent REM sleep, participants were either re-exposed to the odor or to an odorless vehicle, in a counterbalanced within subject design. Reactivation was followed by an interference learning task to probe memory stability after awakening. We show that odor-induced memory reactivation during REM sleep does not stabilize memories against future interference. We propose that the beneficial effect of reactivation during sleep on memory stability might be critically linked to processes characterizing SWS including, e.g., slow oscillatory activity, sleep spindles or low cholinergic tone, which are required for a successful redistribution of memories from medial temporal lobe regions to neocortical long-term stores.

  6. Effects of metal salt addition on odor and process stability during the anaerobic digestion of municipal waste sludge.

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    Abbott, Timothy; Eskicioglu, Cigdem

    2015-12-01

    Anaerobic digestion (AD) is an effective way to recover energy and nutrients from organic waste; however, several issues including the solubilization of bound nutrients and the production of corrosive, highly odorous and toxic volatile sulfur compounds (VSCs) in AD biogas can limit its wider adoption. This study explored the effects of adding two different doses of ferric chloride, aluminum sulfate and magnesium hydroxide directly to the feed of complete mix semi-continuously fed mesophilic ADs on eight of the most odorous VSCs in AD biogas at three different organic loading rates (OLR). Ferric chloride was shown to be extremely effective in reducing VSCs by up to 87%, aluminum sulfate had the opposite effect and increased VSC levels by up to 920%, while magnesium hydroxide was not shown to have any significant impact. Ferric chloride, aluminum sulfate and magnesium hydroxide were effective in reducing the concentration of orthophosphate in AD effluent although both levels of alum addition caused digester failure at elevated OLRs. Extensive foaming was observed within the magnesium hydroxide dosed digesters, particularly at higher doses and high OLRs. Certain metal salt additions may be a valuable tool in overcoming barriers to AD and to meet regulatory targets. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Pattern Recognition Algorithm for High-Sensitivity Odorant Detection in Unknown Environments

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    Duong, Tuan A.

    2012-01-01

    In a realistic odorant detection application environment, the collected sensory data is a mix of unknown chemicals with unknown concentrations and noise. The identification of the odorants among these mixtures is a challenge in data recognition. In addition, deriving their individual concentrations in the mix is also a challenge. A deterministic analytical model was developed to accurately identify odorants and calculate their concentrations in a mixture with noisy data.

  8. Comparison of storage stability of odorous VOCs in polyester aluminum and polyvinyl fluoride tedlar bags

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    Whole air sampling using containers such as flexible bags or rigid canisters is commonly used to collect samples of volatile organic compounds (VOC) in air. The objective of this study was to compare the stability of polyester aluminum (PEA) and polyvinyl fluoride (PVF, brand name Tedlar®) bags for ...

  9. Combining different analytical approaches to identify odor formation mechanisms in polyethylene and polypropylene.

    Science.gov (United States)

    Hopfer, Helene; Haar, Nina; Stockreiter, Wolfgang; Sauer, Christian; Leitner, Erich

    2012-01-01

    In a previous study, we identified carbonyls as highly odor-active compounds in both unprocessed and processed polypropylene (PP) with higher intensities after processing, indicating a temperature-driven forming mechanism. In the presented work, we studied whether (a) these carbonyls are the major odor drivers to the overall odor of polyolefins, (b) their formation is taking place already at moderate temperatures well below the typical processing temperatures, (c) conventional antioxidants in polyolefins can prevent or reduce their formation, and (d) whether reducing the amount of oxygen present can decrease the overall odor. One polyethylene (PE) and one PP were selected, and both stabilized and unstabilized polymer powder samples were exposed to conditions differing in oxygen concentration and aging time. The changes in the volatile fraction as well as the formation of odor-active compounds were monitored using a multidisciplinary approach by combining analytical methods based on gas chromatography (GC), multivariate data analysis, and sensory methods (GC-olfactometry and a sensory panel). Both investigated materials (PE and PP) showed similar degradation products (aldehydes, ketones, carboxylic acids, alcohols, and lactones) which increased dramatically with increasing aging time and the lack of stabilization. Oxidation products, mainly carbonyl compounds, were responsible for the odor of the investigated materials. The main odor drivers were unsaturated ketones and aldehydes with a chain length between six and nine C-atoms. Interestingly, similar odor patterns were found for both stabilized and unstabilized samples, indicating that similar formation processes take place independent of the stabilization.

  10. Does human body odor represent a significant and rewarding social signal to individuals high in social openness?

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    Lübke, Katrin T; Croy, Ilona; Hoenen, Matthias; Gerber, Johannes; Pause, Bettina M; Hummel, Thomas

    2014-01-01

    Across a wide variety of domains, experts differ from novices in their response to stimuli linked to their respective field of expertise. It is currently unknown whether similar patterns can be observed with regard to social expertise. The current study therefore focuses on social openness, a central social skill necessary to initiate social contact. Human body odors were used as social cues, as they inherently signal the presence of another human being. Using functional MRI, hemodynamic brain responses to body odors of women reporting a high (n = 14) or a low (n = 12) level of social openness were compared. Greater activation within the inferior frontal gyrus and the caudate nucleus was observed in high socially open individuals compared to individuals low in social openness. With the inferior frontal gyrus being a crucial part of the human mirror neuron system, and the caudate nucleus being implicated in social reward, it is discussed whether human body odor might constitute more of a significant and rewarding social signal to individuals high in social openness compared to individuals low in social openness process.

  11. Does human body odor represent a significant and rewarding social signal to individuals high in social openness?

    Directory of Open Access Journals (Sweden)

    Katrin T Lübke

    Full Text Available Across a wide variety of domains, experts differ from novices in their response to stimuli linked to their respective field of expertise. It is currently unknown whether similar patterns can be observed with regard to social expertise. The current study therefore focuses on social openness, a central social skill necessary to initiate social contact. Human body odors were used as social cues, as they inherently signal the presence of another human being. Using functional MRI, hemodynamic brain responses to body odors of women reporting a high (n = 14 or a low (n = 12 level of social openness were compared. Greater activation within the inferior frontal gyrus and the caudate nucleus was observed in high socially open individuals compared to individuals low in social openness. With the inferior frontal gyrus being a crucial part of the human mirror neuron system, and the caudate nucleus being implicated in social reward, it is discussed whether human body odor might constitute more of a significant and rewarding social signal to individuals high in social openness compared to individuals low in social openness process.

  12. Optimization of the Odor Microclimate

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    M. V. Jokl

    2002-01-01

    Full Text Available The odor microclimate is formed by gaseous airborne components perceived either as an unpleasant smell or as a pleasant smell. Smells enter the building interior partly from outdoors (exhaust fumes - flower fragrance and partly from indoors (building materials, smoking cigarettes - cosmetics, dishes. They affect the human organism through the olfactory center which is connected to the part of brain that is responsible for controlling people's emotions and sexual feelings: smells therefore participate to a high level in mood formation. Sweet smells have a positive impact on human feelings and on human performance. Criteria for odor microclimate appraisal are presented together with ways of improving the odor microclimate (by stopping odors from spreading within a building, ventilation, air filtration, odor removal by plants, deodorization, etc., including so-called AIR DESIGN.

  13. Odor mortis.

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    Vass, Arpad A

    2012-10-10

    This study, the third of a series on the odor signature of human decomposition, reports on the intermittent nature of chemical evolution from decomposing human remains, and focuses primarily on headspace analysis from soil associated with older human remains (10-60+ years) from different environments around the globe. Fifty grams of soil were collected in 40 mL glass vials with polypropylene sealed lids from soil above known or suspected graves and from subsurface chemical plumes associated with human decompositional events. One hundred eighty six separate samples were analyzed using gas chromatography-mass spectrometry (GC-MS). After comparison to relevant soil controls, approximately fifty volatile chemical compounds were identified as being associated with human remains. This manuscript reports these findings and identifies when and where they are most likely to be detected showing an overall decrease in cyclic and halogenated compounds and an increase in aldehydes and alkanes as time progresses. This research identifies the "odor signatures" unique to the decomposition of human remains with projected ramifications on cadaver dog training procedures and in the development of field portable analytical instruments which can be used to locate human remains in shallow burial sites. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  14. Odor Mortis

    Energy Technology Data Exchange (ETDEWEB)

    Vass, Arpad Alexander [ORNL

    2012-01-01

    This study, the third of a series on the odor signature of human decomposition, reports on the intermittent nature of chemical evolution from decomposing human remains, and focuses primarily on headspace analysis from soil associated with older human remains (10-60+ years) from different environments around the globe. Fifty grams of soil were collected in 40mL glass vials with polypropylene sealed lids from soil above known or suspected graves and from subsurface chemical plumes associated with human decompositional events. One hundred eighty six separate samples were analyzed using gas chromatography-mass spectrometry (GC-MS). After comparison to relevant soil controls, approximately fifty volatile chemical compounds were identified as being associated with human remains. This manuscript reports these findings and identifies when and where they are most likely to be detected showing an overall decrease in cyclic and halogenated compounds and an increase in aldehydes and alkanes as time progresses. This research identifies the 'odor signatures' unique to the decomposition of human remains with projected ramifications on cadaver dog training procedures and in the development of field portable analytical instruments which can be used to locate human remains in shallow burial sites.

  15. Role of Self-Generated Odor Cues in Contextual Representation

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    Aikath, Devdeep; Weible, Aldis P; Rowland, David C; Kentros, Clifford G

    2014-01-01

    As first demonstrated in the patient H.M., the hippocampus is critically involved in forming episodic memories, the recall of “what” happened “where” and “when.” In rodents, the clearest functional correlate of hippocampal primary neurons is the place field: a cell fires predominantly when the animal is in a specific part of the environment, typically defined relative to the available visuospatial cues. However, rodents have relatively poor visual acuity. Furthermore, they are highly adept at navigating in total darkness. This raises the question of how other sensory modalities might contribute to a hippocampal representation of an environment. Rodents have a highly developed olfactory system, suggesting that cues such as odor trails may be important. To test this, we familiarized mice to a visually cued environment over a number of days while maintaining odor cues. During familiarization, self-generated odor cues unique to each animal were collected by re-using absorbent paperboard flooring from one session to the next. Visual and odor cues were then put in conflict by counter-rotating the recording arena and the flooring. Perhaps surprisingly, place fields seemed to follow the visual cue rotation exclusively, raising the question of whether olfactory cues have any influence at all on a hippocampal spatial representation. However, subsequent removal of the familiar, self-generated odor cues severely disrupted both long-term stability and rotation to visual cues in a novel environment. Our data suggest that odor cues, in the absence of additional rule learning, do not provide a discriminative spatial signal that anchors place fields. Such cues do, however, become integral to the context over time and exert a powerful influence on the stability of its hippocampal representation. © 2014 The Authors. Hippocampus Published by Wiley Periodicals, Inc. PMID:24753119

  16. Detection of odor sources and high concentrations of pollutants in the Ore Mountains by modeling of air mass paths

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    Michael Jähn

    2013-04-01

    Full Text Available Since decades odor pollutions are a well-known problem in the Ore Mountains and Vogtland, especially areas close to the border to the Czech Republic. Many facilities in North Bohemia are considered as the main polluters. Most notably these contaminations occur during autumn and winter in conjunction with high pressure weather situations and inversions. In the last years the amount of registered complaints decreased gradually due to manufacturing and shutdown of factories. However, in 2011 there was an exceptional high amount of complaints by the inhabitants. This was connected with a long-lasting stable high pressure weather condition over Central Europe. Prescriptive limits of air pollutants were not exceeded in most cases, though. The used trajectory model TRAJEK can be run with high-resolution reanalysis data of the COSMO (Consortium for Small-Scale Modelling model by Deutscher Wetterdienst (DWD to simulate traces of air mass paths. Hereby backward trajectories of polluted areas and forward trajectories of assumed sources are computed. Moreover, the model system COSMO-MUSCAT (Multi-Scale Chemistry Aerosol Transport is used to simulate tracer propagation so that present flow structures and emitter plumes can be visualized. At reported accidents the source is doubtlessly detected by using trajectory and tracer analysis. A central result of the present study is the fact of the accumulation of air masses in the North Bohemian Basin, which occurs in most cases. Thus, many potential sources of odor problems can come into question. Those can be related to a larger industrial area at its best.

  17. Comparison of storage stability of odorous VOCs in polyester aluminum and polyvinyl fluoride Tedlar® bags.

    Science.gov (United States)

    Kim, Yong-Hyun; Kim, Ki-Hyun; Jo, Sang-Hee; Jeon, Eui-Chan; Sohn, Jong Ryeul; Parker, David B

    2012-01-27

    Whole air sampling using containers such as flexible bags or rigid canisters is commonly used to collect samples of volatile organic compounds (VOC) in air. The objective of this study was to compare the stability of polyester aluminum (PEA) and polyvinyl fluoride (PVF, brand name Tedlar(®)) bags for gaseous VOC sampling. Eight VOC standards (benzene, toluene, p-xylene, styrene, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, and isobutyl alcohol) were placed into each bag at storage times of 0, 2, and 3 days prior to analyses by gas chromatography/mass spectrometry (GC/MS). From each bag representing each storage day, samples of 3 different mass loadings were withdrawn and analyzed to derive response factors (RF) of each chemical between the slope of the GC response (y-axis) vs. loaded mass (x-axis). The relative recoveries (RR) of VOC, if derived by dividing RF value of a given storage day by that of 0 day, varied by time, bag type, and VOC type. If the RR values after three days are compared, those of methyl isobutyl ketone were the highest with 96 (PVF) and 99% (PEA); however, the results of isobutyl alcohol were highly contrasting between the two bags with 31 and 94%, respectively. Differences in RR values between the two bag types increased with storage time, such that RR of PEA bags (88±10%) were superior to those of PVF bags (73±22%) after three days, demonstrating that VOC in PEA bags were more stable than in PVF bags. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Artificial odor map and discrimination of odorants using the odor separating system

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    Imahashi, Masahiro; Miyagi, Kazuki; Takamizawa, Tadashi; Hayashi, Kenshi

    2011-09-01

    In this research, achievement of the odor discrimination was examined. At first, odor separating system was developed which imitates the odor receptive mechanism of biological olfaction. A rough detection of odor becomes possible with this device. Therefore, this device makes it possible to measure the molecular size and the polarity of odorant and discriminate the mixed odor. Then, measuring representative odor molecules belonging to biological glomeruli clusters, odor information is extracted from time course patterns obtained by the system. The extracted features could be used for odor mapping close to the odor map created in the odor receptive mechanism which can classify odor quality by their odor cluster attributes.

  19. High beta and second stability region transport and stability analysis

    International Nuclear Information System (INIS)

    1990-01-01

    This document summarizes progress made on the research of high beta and second region transport and stability. In the area second stability region studies we report on an investigation of the possibility of second region access in the center of TFTR ''supershots.'' The instabilities found may coincide with experimental observation. Significant progress has been made on the resistive stability properties of high beta poloidal ''supershot'' discharges. For these studies profiles were taken from the TRANSP transport analysis code which analyzes experimental data. Invoking flattening of the pressure profile on mode rational surfaces causes tearing modes to persist into the experimental range of interest. Further, the experimental observation of the modes seems to be consistent with the predictions of the MHD model. In addition, code development in several areas has proceeded

  20. Honeybees learn odour mixtures via a selection of key odorants.

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    Judith Reinhard

    2010-02-01

    Full Text Available The honeybee has to detect, process and learn numerous complex odours from her natural environment on a daily basis. Most of these odours are floral scents, which are mixtures of dozens of different odorants. To date, it is still unclear how the bee brain unravels the complex information contained in scent mixtures.This study investigates learning of complex odour mixtures in honeybees using a simple olfactory conditioning procedure, the Proboscis-Extension-Reflex (PER paradigm. Restrained honeybees were trained to three scent mixtures composed of 14 floral odorants each, and then tested with the individual odorants of each mixture. Bees did not respond to all odorants of a mixture equally: They responded well to a selection of key odorants, which were unique for each of the three scent mixtures. Bees showed less or very little response to the other odorants of the mixtures. The bees' response to mixtures composed of only the key odorants was as good as to the original mixtures of 14 odorants. A mixture composed of the other, non-key-odorants elicited a significantly lower response. Neither an odorant's volatility or molecular structure, nor learning efficiencies for individual odorants affected whether an odorant became a key odorant for a particular mixture. Odorant concentration had a positive effect, with odorants at high concentration likely to become key odorants.Our study suggests that the brain processes complex scent mixtures by predominantly learning information from selected key odorants. Our observations on key odorant learning lend significant support to previous work on olfactory learning and mixture processing in honeybees.

  1. Honeybees Learn Odour Mixtures via a Selection of Key Odorants

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    Reinhard, Judith; Sinclair, Michael; Srinivasan, Mandyam V.; Claudianos, Charles

    2010-01-01

    Background The honeybee has to detect, process and learn numerous complex odours from her natural environment on a daily basis. Most of these odours are floral scents, which are mixtures of dozens of different odorants. To date, it is still unclear how the bee brain unravels the complex information contained in scent mixtures. Methodology/Principal Findings This study investigates learning of complex odour mixtures in honeybees using a simple olfactory conditioning procedure, the Proboscis-Extension-Reflex (PER) paradigm. Restrained honeybees were trained to three scent mixtures composed of 14 floral odorants each, and then tested with the individual odorants of each mixture. Bees did not respond to all odorants of a mixture equally: They responded well to a selection of key odorants, which were unique for each of the three scent mixtures. Bees showed less or very little response to the other odorants of the mixtures. The bees' response to mixtures composed of only the key odorants was as good as to the original mixtures of 14 odorants. A mixture composed of the other, non-key-odorants elicited a significantly lower response. Neither an odorant's volatility or molecular structure, nor learning efficiencies for individual odorants affected whether an odorant became a key odorant for a particular mixture. Odorant concentration had a positive effect, with odorants at high concentration likely to become key odorants. Conclusions/Significance Our study suggests that the brain processes complex scent mixtures by predominantly learning information from selected key odorants. Our observations on key odorant learning lend significant support to previous work on olfactory learning and mixture processing in honeybees. PMID:20161714

  2. Nanoporous silica membranes with high hydrothermal stability

    DEFF Research Database (Denmark)

    Boffa, Vittorio; Magnacca, Giualiana; Yue, Yuanzheng

    Despite the use of sol-gel derived nanoporous silica membranes in substitution of traditional separation processes is expected leading to vast energy savings, their intrinsic poor steam-stability hampers their application at an industrial level. Transition metal ions can be used as dopant...... to improve the stability of nanoporous silica structure. This work is a quantitative study on the impact of type and concentration of transition metal ions on the microporous structure and stability of amorphous silica-based membranes, which provides information on how to design chemical compositions...... and synthetic paths for the fabrication of silica-based membranes with a well accessible and highly stabile nanoporous structure...

  3. High-Throughput Automatic Training System for Odor-Based Learned Behaviors in Head-Fixed Mice

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    Zhe Han

    2018-02-01

    Full Text Available Understanding neuronal mechanisms of learned behaviors requires efficient behavioral assays. We designed a high-throughput automatic training system (HATS for olfactory behaviors in head-fixed mice. The hardware and software were constructed to enable automatic training with minimal human intervention. The integrated system was composed of customized 3D-printing supporting components, an odor-delivery unit with fast response, Arduino based hardware-controlling and data-acquisition unit. Furthermore, the customized software was designed to enable automatic training in all training phases, including lick-teaching, shaping and learning. Using HATS, we trained mice to perform delayed non-match to sample (DNMS, delayed paired association (DPA, Go/No-go (GNG, and GNG reversal tasks. These tasks probed cognitive functions including sensory discrimination, working memory, decision making and cognitive flexibility. Mice reached stable levels of performance within several days in the tasks. HATS enabled an experimenter to train eight mice simultaneously, therefore greatly enhanced the experimental efficiency. Combined with causal perturbation and activity recording techniques, HATS can greatly facilitate our understanding of the neural-circuitry mechanisms underlying learned behaviors.

  4. Olfactory Imagination and Odor Processing: Three Same-Different Experiments

    NARCIS (Netherlands)

    Koster, E.P.; Stelt, van der O.; Nixdorf, R.R.; Linschoten, M.R.I.; Mojet, J.; Wijk, de R.A.

    2014-01-01

    Do people who claim to have olfactory imagination process odors more efficiently? In three same–different experiments, using all possible combinations of odors and odor names as primes and targets, selected high imagers (n¿=¿12) were faster (±230 ms; P¿

  5. Odor composition analysis and odor indicator selection during sewage sludge composting

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    Zhu, Yan-li; Zheng, Guo-di; Gao, Ding; Chen, Tong-bin; Wu, Fang-kun; Niu, Ming-jie; Zou, Ke-hua

    2016-01-01

    ABSTRACT On the basis of total temperature increase, normal dehydration, and maturity, the odor compositions of surface and internal piles in a well-run sewage sludge compost plant were analyzed using gas chromatography–mass spectrometry with a liquid nitrogen cooling system and a portable odor detector. Approximately 80 types of substances were detected, including 2 volatile inorganic compounds, 4 sulfur organic compounds, 16 benzenes, 27 alkanes, 15 alkenes, and 19 halogenated compounds. Most pollutants were mainly produced in the mesophilic and pre-thermophilic periods. The sulfur volatile organic compounds contributed significantly to odor and should be controlled primarily. Treatment strategies should be based on the properties of sulfur organic compounds. Hydrogen sulfide, methyl mercaptan, dimethyl disulfide, dimethyl sulfide, ammonia, and carbon disulfide were selected as core indicators. Ammonia, hydrogen sulfide, carbon disulfide, dimethyl disulfide, methyl mercaptan, dimethylbenzene, phenylpropane, and isopentane were designated as concentration indicators. Benzene, m-xylene, p-xylene, dimethylbenzene, dichloromethane, toluene, chlorobenzene, trichloromethane, carbon tetrachloride, and ethylbenzene were selected as health indicators. According to the principle of odor pollution indicator selection, dimethyl disulfide was selected as an odor pollution indicator of sewage sludge composting. Monitoring dimethyl disulfide provides a highly scientific method for modeling and evaluating odor pollution from sewage sludge composting facilities. Implications: Composting is one of the most important methods for sewage sludge treatment and improving the low organic matter content of many agricultural soils. However, odors are inevitably produced during the composting process. Understanding the production and emission patterns of odors is important for odor control and treatment. Core indicators, concentration indicators, and health indicators provide an index

  6. ODOR REMOVAL IN WASTEWATER TREATED BY ROOTS ZONE BED (WETLANDS

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    Waldir Nagel Schirmer

    2010-05-01

    Full Text Available The wetland is a system that uses the roots plants (macrophyte in the domestic wastewater treatment. The mechanisms (physical, chemical and biological ones of organic matter stabilization of effluent and odorous compounds (commonly found in anaerobic biological degradation involve soil, microorganisms and plants. This work uses olfactometry (technical of odors analysis as tool in the evaluation of the odor remotion of sewage treated by Root Zone Sewage Treatment Station (RZSTS in an rural community of Irati City (Brazil. For a better evaluation of the effectiveness of the odor remotion, the odors (rather and downstream treatment has been evaluated in the three olfactometric categories (intensity, character and hedonic tone, according to European standards. The results had pointed that wastewater treated still presented perceivable levels of odor even after significant reduction in intensity (the reduction in the category “very strong” was 89,3% between the entrance and outlet wastewater of the macrophyes station. Moreover, “offensive” category was cited by the jury in the two effluent (entrance and outlet one, with 91% and 40% of answers, respectively; however, in this same question, the wastewater treated presented less aggressive and unpleasant odors. In a general way, the station proposed revealed efficiency in odorous compounds stabilization by anaerobic biological degradation.

  7. Virtual Screening of Plant Volatile Compounds Reveals a High Affinity of Hylamorpha elegans (Coleoptera: Scarabaeidae) Odorant-Binding Proteins for Sesquiterpenes From Its Native Host

    Science.gov (United States)

    Palma-Millanao, Rubén; Yáñez, Osvaldo; Rojas, Maximiliano; Mutis, Ana; Venthur, Herbert; Quiroz, Andrés; Ramírez, Claudio C.

    2016-01-01

    Hylamorpha elegans (Burmeister) is a native Chilean scarab beetle considered to be a relevant agricultural pest to pasture and cereal and small fruit crops. Because of their cryptic habits, control with conventional methods is difficult; therefore, alternative and environmentally friendly control strategies are highly desirable. The study of proteins that participate in the recognition of odorants, such as odorant-binding proteins (OBPs), offers interesting opportunities to identify new compounds with the potential to modify pest behavior and computational screening of compounds, which is commonly used in drug discovery, may help to accelerate the discovery of new semiochemicals. Here, we report the discovery of four OBPs in H. elegans as well as six new volatiles released by its native host Nothofagus obliqua (Mirbel). Molecular docking performed between OBPs and new and previously reported volatiles from N. obliqua revealed the best binding energy values for sesquiterpenic compounds. Despite remarkable divergence at the amino acid level, three of the four OBPs evaluated exhibited the best interaction energy for the same ligands. Molecular dynamics investigation reinforced the importance of sesquiterpenes, showing that hydrophobic residues of the OBPs interacted most frequently with the tested ligands, and binding free energy calculations demonstrated van der Waals and hydrophobic interactions to be the most important. Altogether, the results suggest that sesquiterpenes are interesting candidates for in vitro and in vivo assays to assess their potential application in pest management strategies. PMID:27012867

  8. Evolution of potent odorants within the volatile metabolome of high-quality hazelnuts (Corylus avellana L.): evaluation by comprehensive two-dimensional gas chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Rosso, Marta Cialiè; Liberto, Erica; Spigolon, Nicola; Fontana, Mauro; Somenzi, Marco; Bicchi, Carlo; Cordero, Chiara

    2018-01-09

    Within the pattern of volatiles released by food products (volatilome), potent odorants are bio-active compounds that trigger aroma perception by activating a complex array of odor receptors (ORs) in the regio olfactoria. Their informative role is fundamental to select optimal post-harvest and storage conditions and preserve food sensory quality. This study addresses the volatile metabolome from high-quality hazelnuts (Corylus avellana L.) from the Ordu region (Turkey) and Tonda Romana from Italy, and investigates its evolution throughout the production chain (post-harvest, industrial storage, roasting) to find functional correlations between technological strategies and product quality. The volatile metabolome is analyzed by headspace solid-phase microextration combined with comprehensive two-dimensional gas chromatography and mass spectrometry. Dedicated pattern recognition, based on 2D data (targeted fingerprinting), is used to mine analytical outputs, while principal component analysis (PCA), Fisher ratio, hierarchical clustering, and analysis of variance are used to find decision makers among the most informative chemicals. Low-temperature drying (18-20 °C) has a decisive effect on quality; it correlates negatively with bacteria and mold metabolic activity, nut viability, and lipid oxidation products (2-methyl-1-propanol, 3-methyl-1-butanol, 2-ethyl-1-hexanol, 2-octanol, 1-octen-3-ol, hexanal, octanal and (E)-2-heptanal). Protective atmosphere storage (99% N 2 -1% O 2 ) effectively limits lipid oxidation for 9-12 months after nut harvest. The combination of optimal drying and storage preserves the aroma potential; after roasting at different shelf-lives, key odorants responsible for malty and buttery (2- and 3-methylbutanal, 2,3-butanedione and 2,3-pentanedione), earthy (methylpyrazine, 2-ethyl-5-methyl pyrazine and 3-ethyl-2,5-dimethyl pyrazine) and caramel-like and musty notes (2,5-dimethyl-4-hydroxy-3(2H)-furanone - furaneol and acetyl pyrrole) show no

  9. Psychology of fragrance use: perception of individual odor and perfume blends reveals a mechanism for idiosyncratic effects on fragrance choice.

    Science.gov (United States)

    Lenochová, Pavlína; Vohnoutová, Pavla; Roberts, S Craig; Oberzaucher, Elisabeth; Grammer, Karl; Havlíček, Jan

    2012-01-01

    Cross-culturally, fragrances are used to modulate body odor, but the psychology of fragrance choice has been largely overlooked. The prevalent view is that fragrances mask an individual's body odor and improve its pleasantness. In two experiments, we found positive effects of perfume on body odor perception. Importantly, however, this was modulated by significant interactions with individual odor donors. Fragrances thus appear to interact with body odor, creating an individually-specific odor mixture. In a third experiment, the odor mixture of an individual's body odor and their preferred perfume was perceived as more pleasant than a blend of the same body odor with a randomly-allocated perfume, even when there was no difference in pleasantness between the perfumes. This indicates that fragrance use extends beyond simple masking effects and that people choose perfumes that interact well with their own odor. Our results provide an explanation for the highly individual nature of perfume choice.

  10. Psychology of fragrance use: perception of individual odor and perfume blends reveals a mechanism for idiosyncratic effects on fragrance choice.

    Directory of Open Access Journals (Sweden)

    Pavlína Lenochová

    Full Text Available Cross-culturally, fragrances are used to modulate body odor, but the psychology of fragrance choice has been largely overlooked. The prevalent view is that fragrances mask an individual's body odor and improve its pleasantness. In two experiments, we found positive effects of perfume on body odor perception. Importantly, however, this was modulated by significant interactions with individual odor donors. Fragrances thus appear to interact with body odor, creating an individually-specific odor mixture. In a third experiment, the odor mixture of an individual's body odor and their preferred perfume was perceived as more pleasant than a blend of the same body odor with a randomly-allocated perfume, even when there was no difference in pleasantness between the perfumes. This indicates that fragrance use extends beyond simple masking effects and that people choose perfumes that interact well with their own odor. Our results provide an explanation for the highly individual nature of perfume choice.

  11. [Odor sensing system and olfactory display].

    Science.gov (United States)

    Nakamoto, Takamichi

    2014-01-01

    In this review, an odor sensing system and an olfactory display are introduced into people in pharmacy. An odor sensing system consists of an array of sensors with partially overlapping specificities and pattern recognition technique. One of examples of odor sensing systems is a halitosis sensor which quantifies the mixture composition of three volatile sulfide compounds. A halitosis sensor was realized using a preconcentrator to raise sensitivity and an electrochemical sensor array to suppress the influence of humidity. Partial least squares (PLS) method was used to quantify the mixture composition. The experiment reveals that the sufficient accuracy was obtained. Moreover, the olfactory display, which present scents to human noses, is explained. A multi-component olfactory display enables the presentation of a variety of smells. The two types of multi-component olfactory display are described. The first one uses many solenoid valves with high speed switching. The valve ON frequency determines the concentration of the corresponding odor component. The latter one consists of miniaturized liquid pumps and a surface acoustic wave (SAW) atomizer. It enables the wearable olfactory display without smell persistence. Finally, the application of the olfactory display is demonstrated. Virtual ice cream shop with scents was made as a content of interactive art. People can enjoy harmony among vision, audition and olfaction. In conclusion, both odor sensing system and olfactory display can contribute to the field of human health care.

  12. Human ovarian carcinomas detected by specific odor.

    Science.gov (United States)

    Horvath, György; Järverud, Gunvor Af Klinteberg; Järverud, Sven; Horváth, István

    2008-06-01

    The high mortality rate associated with ovarian carcinoma is mainly owing to late diagnosis. It is thus essential to develop inexpensive and simple methods for early diagnosis. Papers on canine scent detection of malignancies such as melanoma and bladder, lung, and breast cancer have recently been published in peer-reviewed journals, indicating a new diagnostic tool for malignancies. However, in these studies the dogs may have responded to odors associated with cancer, such as inflammation or metabolic products, rather than specifically to cancer itself. Therefore, it is important to ascertain whether or not human cancers are characterized by specific odors. We hypothesized that if ovarian carcinoma emits a specific odor, dogs may be trained to detect it. Using our training method, we taught a dog to distinguish different histopathological types and grades of ovarian carcinomas, including borderline tumors, from healthy control samples. Double-blind tests showed 100% sensitivity and 97.5% specificity. Moreover, the odor of ovarian carcinomas seems to differ from those of other gynecological malignances such cervical, endometrial, and vulvar carcinomas. Our study strongly suggests that the most common ovarian carcinomas are characterized by a single specific odor.

  13. A unique memory process modulated by emotion underpins successful odor recognition and episodic retrieval in humans

    Science.gov (United States)

    Saive, Anne-Lise; Royet, Jean-Pierre; Ravel, Nadine; Thévenet, Marc; Garcia, Samuel; Plailly, Jane

    2014-01-01

    We behaviorally explore the link between olfaction, emotion and memory by testing the hypothesis that the emotion carried by odors facilitates the memory of specific unique events. To investigate this idea, we used a novel behavioral approach inspired by a paradigm developed by our team to study episodic memory in a controlled and as ecological as possible way in humans. The participants freely explored three unique and rich laboratory episodes; each episode consisted of three unfamiliar odors (What) positioned at three specific locations (Where) within a visual context (Which context). During the retrieval test, which occurred 24–72 h after the encoding, odors were used to trigger the retrieval of the complex episodes. The participants were proficient in recognizing the target odors among distractors and retrieving the visuospatial context in which they were encountered. The episodic nature of the task generated high and stable memory performances, which were accompanied by faster responses and slower and deeper breathing. Successful odor recognition and episodic memory were not related to differences in odor investigation at encoding. However, memory performances were influenced by the emotional content of the odors, regardless of odor valence, with both pleasant and unpleasant odors generating higher recognition and episodic retrieval than neutral odors. Finally, the present study also suggested that when the binding between the odors and the spatio-contextual features of the episode was successful, the odor recognition and the episodic retrieval collapsed into a unique memory process that began as soon as the participants smelled the odors. PMID:24936176

  14. A unique memory process modulated by emotion underpins successful odor recognition and episodic retrieval in humans

    Directory of Open Access Journals (Sweden)

    Anne-Lise eSaive

    2014-06-01

    Full Text Available We behaviorally explore the link between olfaction, emotion and memory by testing the hypothesis that the emotion carried by odors facilitates the memory of specific unique events. To investigate this idea, we used a novel behavioral approach inspired by a paradigm developed by our team to study episodic memory in a controlled and as ecological as possible way in humans. The participants freely explored three unique and rich laboratory episodes; each episode consisted of three unfamiliar odors (What positioned at three specific locations (Where within a visual context (Which context. During the retrieval test, which occurred 24 to 72 hours after the encoding, odors were used to trigger the retrieval of the complex episodes. The participants were proficient in recognizing the target odors among distractors and retrieving the visuospatial context in which they were encountered. The episodic nature of the task generated high and stable memory performances, which were accompanied by faster responses and slower and deeper breathing. Successful odor recognition and episodic memory were not related to differences in odor investigation at encoding. However, memory performances were influenced by the emotional content of the odors, regardless of odor valence, with both pleasant and unpleasant odors generating higher recognition and episodic retrieval than neutral odors. Finally, the present study also suggested that when the binding between the odors and the spatio-contextual features of the episode was successful, the odor recognition and the episodic retrieval collapsed into a unique memory process that began as soon as the participants smelled the odors.

  15. The perception of odor objects in everyday life: a review on the processing of odor mixtures

    Science.gov (United States)

    Thomas-Danguin, Thierry; Sinding, Charlotte; Romagny, Sébastien; El Mountassir, Fouzia; Atanasova, Boriana; Le Berre, Elodie; Le Bon, Anne-Marie; Coureaud, Gérard

    2014-01-01

    Smelling monomolecular odors hardly ever occurs in everyday life, and the daily functioning of the sense of smell relies primarily on the processing of complex mixtures of volatiles that are present in the environment (e.g., emanating from food or conspecifics). Such processing allows for the instantaneous recognition and categorization of smells and also for the discrimination of odors among others to extract relevant information and to adapt efficiently in different contexts. The neurophysiological mechanisms underpinning this highly efficient analysis of complex mixtures of odorants is beginning to be unraveled and support the idea that olfaction, as vision and audition, relies on odor-objects encoding. This configural processing of odor mixtures, which is empirically subject to important applications in our societies (e.g., the art of perfumers, flavorists, and wine makers), has been scientifically studied only during the last decades. This processing depends on many individual factors, among which are the developmental stage, lifestyle, physiological and mood state, and cognitive skills; this processing also presents striking similarities between species. The present review gathers the recent findings, as observed in animals, healthy subjects, and/or individuals with affective disorders, supporting the perception of complex odor stimuli as odor objects. It also discusses peripheral to central processing, and cognitive and behavioral significance. Finally, this review highlights that the study of odor mixtures is an original window allowing for the investigation of daily olfaction and emphasizes the need for knowledge about the underlying biological processes, which appear to be crucial for our representation and adaptation to the chemical environment. PMID:24917831

  16. Sensory Preconditioning in Newborn Rabbits: From Common to Distinct Odor Memories

    Science.gov (United States)

    Coureaud, Gerard; Tourat, Audrey; Ferreira, Guillaume

    2013-01-01

    This study evaluated whether olfactory preconditioning is functional in newborn rabbits and based on joined or independent memory of odorants. First, after exposure to odorants A+B, the conditioning of A led to high responsiveness to odorant B. Second, responsiveness to B persisted after amnesia of A. Third, preconditioning was also functional…

  17. Olfaction and Hearing Based Mobile Robot Navigation for Odor/Sound Source Search

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2011-02-01

    Full Text Available Bionic technology provides a new elicitation for mobile robot navigation since it explores the way to imitate biological senses. In the present study, the challenging problem was how to fuse different biological senses and guide distributed robots to cooperate with each other for target searching. This paper integrates smell, hearing and touch to design an odor/sound tracking multi-robot system. The olfactory robot tracks the chemical odor plume step by step through information fusion from gas sensors and airflow sensors, while two hearing robots localize the sound source by time delay estimation (TDE and the geometrical position of microphone array. Furthermore, this paper presents a heading direction based mobile robot navigation algorithm, by which the robot can automatically and stably adjust its velocity and direction according to the deviation between the current heading direction measured by magnetoresistive sensor and the expected heading direction acquired through the odor/sound localization strategies. Simultaneously, one robot can communicate with the other robots via a wireless sensor network (WSN. Experimental results show that the olfactory robot can pinpoint the odor source within the distance of 2 m, while two hearing robots can quickly localize and track the olfactory robot in 2 min. The devised multi-robot system can achieve target search with a considerable success ratio and high stability.

  18. Health effects of indoor odorants.

    Science.gov (United States)

    Cone, J E; Shusterman, D

    1991-11-01

    People assess the quality of the air indoors primarily on the basis of its odors and on their perception of associated health risk. The major current contributors to indoor odorants are human occupant odors (body odor), environmental tobacco smoke, volatile building materials, bio-odorants (particularly mold and animal-derived materials), air fresheners, deodorants, and perfumes. These are most often present as complex mixtures, making measurement of the total odorant problem difficult. There is no current method of measuring human body odor, other than by human panel studies of expert judges of air quality. Human body odors have been quantitated in terms of the "olf" which is the amount of air pollution produced by the average person. Another quantitative unit of odorants is the "decipol," which is the perceived level of pollution produced by the average human ventilated by 10 L/sec of unpolluted air or its equivalent level of dissatisfaction from nonhuman air pollutants. The standard regulatory approach, focusing on individual constituents or chemicals, is not likely to be successful in adequately controlling odorants in indoor air. Besides the current approach of setting minimum ventilation standards to prevent health effects due to indoor air pollution, a standard based on the olf or decipol unit might be more efficacious as well as simpler to measure.

  19. Odors as triggering and worsening factors for migraine in men

    Directory of Open Access Journals (Sweden)

    A M Lima

    2011-01-01

    Full Text Available OBJECTIVE: To assess the role of odors in triggering or worsening migraine in men. METHOD: Ninety-eight male migraineurs from the general population were assessed individually through questionnaires. Environmental factors relating to their migraine were reported, with special focus on the role of odors. RESULTS: Odors were the second most frequent triggering factor for migraine attacks (48%, behind stressful situations (59%. Likewise, odors were the second most frequent worsening factor (73%, just behind excessive light (74%. Thirty-three individuals (33.4% stated that odors were both triggering and worsening factors for their migraine attacks. Perfume, cigarette smoke and cleaning products were the most frequent migraine-related odors reported by these male migraineurs. CONCLUSION: This was the first study to assess the role of odors in migraine exclusively in men. There was a high degree of odor-related migraine among these men, thus suggesting that patient education could alert such individuals to gender-related factors, since different triggering and worsening factors have been reported by males and females.

  20. Voltage stabilizers for high temperature furnace

    International Nuclear Information System (INIS)

    Huet, J.

    1966-10-01

    The stabilization of furnace temperatures in the range 1500-2500 C has been achieved by controlling the effective (rms) value of the supply voltage of the heating element. Temperature variations are less than, or equal to, one degree C in the whole working range of the furnace. Two types of set-ups have been developed: one is static, the other takes use of a servo-motor. (author) [fr

  1. Flavor, fragrance, and odor analysis

    National Research Council Canada - National Science Library

    Marsili, Ray

    2012-01-01

    ...)-olfactometry, and electronic-nose technology, this new edition discusses the significant advantage of these methods for flavor and odor studies in the food, cosmetic, and pharmaceutical industries...

  2. Highly concentrated emulsions. Physicochemical principles of the preparation and stability

    International Nuclear Information System (INIS)

    Babak, V G

    2008-01-01

    Theoretical and experimental studies on highly concentrated emulsions are critically analysed. The views on the relationship between the stability of surfactant-stabilised emulsions and the properties of microemulsion phases formed in surfactant-water-oil ternary systems are considered. The empirical criteria and rules that can be used to predict the type and stability of emulsions are presented. The physicochemical factors determining the rupture stability of emulsion films are discussed.

  3. Stabilization of Highway Expansive Soils with High Loss on Ignition ...

    African Journals Online (AJOL)

    This study was carried out to evaluate the effect of high loss on ignition content cement kiln dust on the stabilization of highway expansive soils. Laboratory tests were performed on the natural and stabilized soil samples in accordance with BS 1377 (1990) and BS 1924 (1990), respectively. The preliminary investigation ...

  4. Transcriptomic and Proteomic Profiling Revealed High Proportions of Odorant Binding and Antimicrobial Defense Proteins in Olfactory Tissues of the House Mouse

    Directory of Open Access Journals (Sweden)

    Barbora Kuntová

    2018-02-01

    Full Text Available Mammalian olfaction depends on chemosensory neurons of the main olfactory epithelia (MOE, and/or of the accessory olfactory epithelia in the vomeronasal organ (VNO. Thus, we have generated the VNO and MOE transcriptomes and the nasal cavity proteome of the house mouse, Mus musculus musculus. Both transcriptomes had low levels of sexual dimorphisms, while the soluble proteome of the nasal cavity revealed high levels of sexual dimorphism similar to that previously reported in tears and saliva. Due to low levels of sexual dimorphism in the olfactory receptors in MOE and VNO, the sex-specific sensing seems less likely to be dependent on receptor repertoires. However, olfaction may also depend on a continuous removal of background compounds from the sites of detection. Odorant binding proteins (OBPs are thought to be involved in this process and in our study Obp transcripts were most expressed along other lipocalins (e.g., Lcn13, Lcn14 and antimicrobial proteins. At the level of proteome, OBPs were highly abundant with only few being sexually dimorphic. We have, however, detected the major urinary proteins MUP4 and MUP5 in males and females and the male-biased central/group-B MUPs that were thought to be abundant mainly in the urine. The exocrine gland-secreted peptides ESP1 and ESP22 were male-biased but not male-specific in the nose. For the first time, we demonstrate that the expression of nasal lipocalins correlates with antimicrobial proteins thus suggesting that their individual variation may be linked to evolvable mechanisms that regulate natural microbiota and pathogens that regularly enter the body along the ‘eyes-nose-oral cavity’ axis.

  5. Differential Dynamics of Amino Acid Release in the Amygdala and Olfactory Cortex during Odor Fear Acquisition as Revealed with Simultaneous High Temporal Resolution Microdialysis

    Science.gov (United States)

    Hegoburu, Chloe; Sevelinges, Yannick; Thevenet, Marc; Gervais, Remi; Parrot, Sandrine; Mouly, Anne-Marie

    2009-01-01

    Although the amygdala seems to be essential to the formation and storage of fear memories, it might store only some aspects of the aversive event and facilitate the storage of more specific sensory aspects in cortical areas. We addressed the time course of amygdala and cortical activation in the context of odor fear conditioning in rats. Using…

  6. High temperature stability of materials and structures

    International Nuclear Information System (INIS)

    Solomin, N.V.

    1980-01-01

    The problems of high temperature resistance of materials under the effect of mechanic and thermomechanic stresses are considered as well as the resistance of elements of constructions to high temperature inelastic deformation under loading. New experimental data on material properties are presented, the original technique for calculating inelastic deformation of particular bodies is presented [ru

  7. Quantitative gas chromatography-olfactometry carried out at different dilutions of an extract. Key differences in the odor profiles of four high-quality Spanish aged red wines.

    Science.gov (United States)

    Ferreira, V; Aznar, M; López, R; Cacho, J

    2001-10-01

    Four Spanish aged red wines made in different wine-making areas have been extracted, and the extracts and their 1:5, 1:50, and 1:500 dilutions have been analyzed by a gas chromatography-olfactometry (GC-O) approach in which three judges evaluated odor intensity on a four-point scale. Sixty-nine different odor regions were detected in the GC-O profiles of wines, 63 of which could be identified. GC-O data have been processed to calculate averaged flavor dilution factors (FD). Different ANOVA strategies have been further applied on FD and on intensity data to check for significant differences among wines and to assess the effects of dilution and the judge. Data show that FD and the average intensity of the odorants are strongly correlated (r(2) = 0.892). However, the measurement of intensity represents a quantitative advantage in terms of detecting differences. For some odorants, dilution exerts a critical role in the detection of differences. Significant differences among wines have been found in 30 of the 69 odorants detected in the experiment. Most of these differences are introduced by grape compounds such as methyl benzoate and terpenols, by compounds released by the wood, such as furfural, (Z)-whiskey lactone, Furaneol, 4-propylguaiacol, eugenol, 4-ethylphenol, 2,6-dimethoxyphenol, isoeugenol, and ethyl vanillate, by compounds formed by lactic acid bacteria, such as 2,3-butanedione and acetoine, or by compounds formed during the oxidative storage of wines, such as methional, sotolon, o-aminoacetophenone, and phenylacetic acid. The most important differences from a quantitative point of view are due to 2-methyl-3-mercaptofuran, 4-propylguaiacol, 2,6-dimethoxyphenol, and isoeugenol.

  8. Mammalian odorant receptor tuning breadth persists across distinct odorant panels.

    Directory of Open Access Journals (Sweden)

    Devin Kepchia

    Full Text Available The molecular receptive range (MRR of a mammalian odorant receptor (OR is the set of odorant structures that activate the OR, while the distribution of these odorant structures across odor space is the tuning breadth of the OR. Variation in tuning breadth is thought to be an important property of ORs, with the MRRs of these receptors varying from narrowly to broadly tuned. However, defining the tuning breadth of an OR is a technical challenge. For practical reasons, a screening panel that broadly covers odor space must be limited to sparse coverage of the many potential structures in that space. When screened with such a panel, ORs with different odorant specificities, but equal tuning breadths, might appear to have different tuning breadths due to chance. We hypothesized that ORs would maintain their tuning breadths across distinct odorant panels. We constructed a new screening panel that was broadly distributed across an estimated odor space and contained compounds distinct from previous panels. We used this new screening panel to test several murine ORs that were previously characterized as having different tuning breadths. ORs were expressed in Xenopus laevis oocytes and assayed by two-electrode voltage clamp electrophysiology. MOR256-17, an OR previously characterized as broadly tuned, responded to nine novel compounds from our new screening panel that were structurally diverse and broadly dispersed across an estimated odor space. MOR256-22, an OR previously characterized as narrowly tuned, responded to a single novel compound that was structurally similar to a previously known ligand for this receptor. MOR174-9, a well-characterized receptor with a narrowly tuned MRR, did not respond to any novel compounds in our new panel. These results support the idea that variation in tuning breadth among these three ORs is not an artifact of the screening protocol, but is an intrinsic property of the receptors.

  9. A High Reliability Frequency Stabilized Semiconductor Laser Source Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA needs high stability laser source of 1W output power for Lidar applications. Princeton Optronics has developed ultra-stable, narrow linewidth diode pumped solid...

  10. Review of Power System Stability with High Wind Power Penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Chen, Zhe

    2015-01-01

    This paper presents an overview of researches on power system stability with high wind power penetration including analyzing methods and improvement approaches. Power system stability issues can be classified diversely according to different considerations. Each classified issue has special...... analyzing methods and stability improvement approaches. With increasing wind power penetration, system balancing and the reduced inertia may cause a big threaten for stable operation of power systems. To mitigate or eliminate the wind impacts for high wind penetration systems, although the practical...... and reliable choices currently are the strong outside connections or sufficient reserve capacity constructions, many novel theories and approaches are invented to investigate the stability issues, looking forward to an extra-high penetration or totally renewable resource based power systems. These analyzing...

  11. Understanding odor information segregation in the olfactory bulb by means of mitral and tufted cells.

    Directory of Open Access Journals (Sweden)

    Davide Polese

    Full Text Available Odor identification is one of the main tasks of the olfactory system. It is performed almost independently from the concentration of the odor providing a robust recognition. This capacity to ignore concentration information does not preclude the olfactory system from estimating concentration itself. Significant experimental evidence has indicated that the olfactory system is able to infer simultaneously odor identity and intensity. However, it is still unclear at what level or levels of the olfactory pathway this segregation of information occurs. In this work, we study whether this odor information segregation is performed at the input stage of the olfactory bulb: the glomerular layer. To this end, we built a detailed neural model of the glomerular layer based on its known anatomical connections and conducted two simulated odor experiments. In the first experiment, the model was exposed to an odor stimulus dataset composed of six different odorants, each one dosed at six different concentrations. In the second experiment, we conducted an odor morphing experiment where a sequence of binary mixtures going from one odor to another through intermediate mixtures was presented to the model. The results of the experiments were visualized using principal components analysis and analyzed with hierarchical clustering to unveil the structure of the high-dimensional output space. Additionally, Fisher's discriminant ratio and Pearson's correlation coefficient were used to quantify odor identity and odor concentration information respectively. Our results showed that the architecture of the glomerular layer was able to mediate the segregation of odor information obtaining output spiking sequences of the principal neurons, namely the mitral and external tufted cells, strongly correlated with odor identity and concentration, respectively. An important conclusion is also that the morphological difference between the principal neurons is not key to achieve odor

  12. High stability design for new centrifugal compressor

    Science.gov (United States)

    Kanki, H.; Katayama, K.; Morii, S.; Mouri, Y.; Umemura, S.; Ozawa, U.; Oda, T.

    1989-01-01

    It is essential that high-performance centrifugal compressors be free of subsynchronous vibrations. A new high-performance centrifugal compressor has been developed by applying the latest rotordynamics knowledge and design techniques: (1) To improve the system damping, a specially designed oil film seal was developed. This seal attained a damping ratio three times that of the conventional design. The oil film seal contains a special damper ring in the seal cartridge. (2) To reduce the destabilizing effect of the labyrinth seal, a special swirl canceler (anti-swirl nozzle) was applied to the balance piston seal. (3) To confirm the system damping margin, the dynamic simulation rotor model test and the full load test applied the vibration exciting test in actual load conditions.

  13. Structural stability of high entropy alloys under pressure and temperature

    DEFF Research Database (Denmark)

    Ahmad, Azkar S.; Su, Y.; Liu, S. Y.

    2017-01-01

    The stability of high-entropy alloys (HEAs) is a key issue before their selection for industrial applications. In this study, in-situ high-pressure and high-temperature synchrotron radiation X-ray diffraction experiments have been performed on three typical HEAs Ni20Co20Fe20Mn20Cr20, Hf25Nb25Zr25Ti...

  14. Temperature Stabilized Characterization of High Voltage Power Supplies

    CERN Document Server

    Krarup, Ole

    2017-01-01

    High precision measurements of the masses of nuclear ions in the ISOLTRAP experiment relies on an MR-ToF. A major source of noise and drift is the instability of the high voltage power supplies employed. Electrical noise and temperature changes can broaden peaks in time-of-flight spectra and shift the position of peaks between runs. In this report we investigate how the noise and drift of high-voltage power supplies can be characterized. Results indicate that analog power supplies generally have better relative stability than digitally controlled ones, and that the high temperature coefficients of all power supplies merit efforts to stabilize them.

  15. On the thermal stability length dependence of high TC superconductors

    International Nuclear Information System (INIS)

    Maytal, B.Z.; Yang, S.; Waldrop, J.; Pfotenhauer, J.M.

    1996-01-01

    The margin of stability for high T c superconductors may be characterized by the lowest thermal pulse that results in a quench. A numerical code, developed to investigate this stability margin, accounts for the temperature dependence of the thermal conductivity, electrical resistivity and heat capacity of the materials involved. The conductor is cooled solely by thermal conduction along its length, and its stability is studied as function of the length. It is found that the stability margin for a pure BSCCO 2212 conductor is independent of the length. However, the stability margin for a composite conductor obtained by adding 10 % (by volume) of silver to the BSCCO is found to be strongly length dependent. A transition length is identified, for which shorter lengths exhibit a dramatically higher stability margin. This feature results when the length dependent thermal diffusion time is shorter than the time required to determine the conductor's stability. This study confirms and explains the growing awareness that if normal zones appear in high T c coils, they will remain fairly localized

  16. Development of sulfur- and nitrogen- free hydrogen odorants - An important step toward a safe hydrogen society -

    International Nuclear Information System (INIS)

    Nakamura, N.; Oshikawa, K.; Hasegawa, H.; Le Lay, M.; Iwase, M.; Braun, N.A.; Eilers, J.; Walz, A.; Vogt, M.; Herr, M.

    2006-01-01

    We have developed four sulfur-free and nitrogen-free odorants, which can be effectively used to odorize hydrogen. The odors were described through an olfactory test as alarming, strange, and chemical, giving sense of danger to the person who smells the odor. The safety of the material has been assessed and has been shown to be safe for usage. Testing the stability of odorized hydrogen in 80 MPa pressurized state, it was shown for a period of 13 weeks that the odorant retained its warning odor. Using the odorized hydrogen, FC duration test at 0.2 A/cm 2 was carried out for over 900 h without significant decrease in performance or the detectable degradation of MEA. The outlet of the fuel cell had no warning odor, suggesting deodorization on the catalyst. Use of activated charcoal as an adsorbent showed that the deodorization could be effectively carried out, ensuring that normal operation conditions are not perceived as a hydrogen leakage. (authors)

  17. Stabilization of Mercury in High pH Tank Sludges

    Energy Technology Data Exchange (ETDEWEB)

    Spence, R.; Barton, J.

    2003-02-24

    DOE complex contains many tank sludges contaminated with mercury. The high pH of these tank sludges typically fails to stabilize the mercury, resulting in these radioactive wastes also being characteristically hazardous or mixed waste. The traditional treatment for soluble inorganic mercury species is precipitation as insoluble mercuric sulfide. Sulfide treatment and a commercial mercury-stabilizing product were tested on surrogate sludges at various alkaline pH values. Neither the sulfide nor the commercial product stabilized the mercury sufficiently at the high pH of the tank sludges to pass the Toxicity Characteristic Leach Procedure (TCLP) treatment standards of the Resource Conservation and Recovery Act (RCRA). The commercial product also failed to stabilize the mercury in samples of the actual tank sludges.

  18. Adaptation of urine source separation in tropical cities: Process optimization and odor mitigation.

    Science.gov (United States)

    Zhang, Jiefeng; Giannis, Apostolos; Chang, Victor W C; Ng, Bernard J H; Wang, Jing-Yuan

    2013-04-01

    Source-separating urine from other domestic wastewaters promotes a more sustainable municipal wastewater treatment system. This study investigated the feasibility and potential issues of applying a urine source-separation system in tropical urban settings. The results showed that source-separated urine underwent rapid urea-hydrolysis (ureolysis) at temperatures between 34-40 degrees C, stale/fresh urine ratios greater than 40%, and/or with slight fecal cross-contamination. Undiluted (or low-diluted) urine favored ureolysis; this can be monitored by measuring conductivity as a reliable and efficient indicator The optimized parameters demonstrated that an effective urine source-separation system is achievable in tropical urban areas. On the other hand, the initial release of CO2 and NH3 led to an elevated pressure in the headspace of the collection reservoir, which then dropped to a negative value, primarily due to oxygen depletion by the microbial activity in the gradually alkalized urine. Another potential odor source during the ureolysis process was derived from the high production of volatile fatty acids (VFA), which were mainly acetic, propanoic, and butyric acids. Health concerns related to odor issues might limit the application of source separation systems in urban areas; it is therefore vital to systematically monitor and control the odor emissions from a source separation system. As such, an enhanced ureolysis process can attenuate the odor emissions. Urine source separation is promising to improve the management of domestic wastewater in a more sustainable way. The work demonstrates the achievability of an effective urine source-separation system in tropical urban areas. The installation of urine-stabilization tanks beneath high-rise buildings lowers the risk of pipe clogging. Conductivity measurement can be utilized as a reliable process indicator for an automated system. However, urine hydrolysis raises a strong potential of odor emission (both inorganic

  19. Mesophase Formation Stabilizes High-purity Magic-sized Clusters

    KAUST Repository

    Nevers, Douglas R.

    2018-01-27

    Magic-sized clusters (MSCs) are renowned for their identical size and closed-shell stability that inhibit conventional nanoparticle (NP) growth processes. Though MSCs have been of increasing interest, understanding the reaction pathways toward their nucleation and stabilization is an outstanding issue. In this work, we demonstrate that high concentration synthesis (1000 mM) promotes a well-defined reaction pathway to form high-purity MSCs (>99.9%). The MSCs are resistant to typical growth and dissolution processes. Based on insights from in-situ X-ray scattering analysis, we attribute this stability to the accompanying production of a large, hexagonal organic-inorganic mesophase (>100 nm grain size) that arrests growth of the MSCs and prevents NP growth. At intermediate concentrations (500 mM), the MSC mesophase forms, but is unstable, resulting in NP growth at the expense of the assemblies. These results provide an alternate explanation for the high stability of MSCs. Whereas the conventional mantra has been that the stability of MSCs derives from the precise arrangement of the inorganic structures (i.e., closed-shell atomic packing), we demonstrate that anisotropic clusters can also be stabilized by self-forming fibrous mesophase assemblies. At lower concentration (<200 mM or >16 acid-to-metal), MSCs are further destabilized and NPs formation dominates that of MSCs. Overall, the high concentration approach intensifies and showcases inherent concentration-dependent surfactant phase behavior that is not accessible in conventional (i.e., dilute) conditions. This work provides not only a robust method to synthesize, stabilize, and study identical MSC products, but also uncovers an underappreciated stabilizing interaction between surfactants and clusters.

  20. Thermal stability of high temperature structural alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, C.E.; Rasefske, R.K.; Castagna, A. [Lockheed Martin Corp., Schenectady, NY (United States)

    1999-03-01

    High temperature structural alloys were evaluated for suitability for long term operation at elevated temperatures. The effect of elevated temperature exposure on the microstructure and mechanical properties of a number of alloys was characterized. Fe-based alloys (330 stainless steel, 800H, and mechanically alloyed MA 956), and Ni-based alloys (Hastelloy X, Haynes 230, Alloy 718, and mechanically alloyed MA 758) were evaluated for room temperature tensile and impact toughness properties after exposure at 750 C for 10,000 hours. Of the Fe-based alloys evaluated, 330 stainless steel and 800H showed secondary carbide (M{sub 23}C{sub 6}) precipitation and a corresponding reduction in ductility and toughness as compared to the as-received condition. Within the group of Ni-based alloys tested, Alloy 718 showed the most dramatic structure change as it formed delta phase during 10,000 hours of exposure at 750 C with significant reductions in strength, ductility, and toughness. Haynes 230 and Hastelloy X showed significant M{sub 23}C{sub 6} carbide precipitation and a resulting reduction in ductility and toughness. Haynes 230 was also evaluated after 10,000 hours of exposure at 850, 950, and 1050 C. For the 750--950 C exposures the M{sub 23}C{sub 6} carbides in Haynes 230 coarsened. This resulted in large reductions in impact strength and ductility for the 750, 850 and 950 C specimens. The 1050 C exposure specimens showed the resolution of M{sub 23}C{sub 6} secondary carbides, and mechanical properties similar to the as-received solution annealed condition.

  1. Flavor, fragrance, and odor analysis

    National Research Council Canada - National Science Library

    Marsili, Ray

    2012-01-01

    ... solid-phase micro extraction procedures. It also presents important updates on GC-olfactometry as a tool for studying flavor synergy effects"-- "Sample preparation techniques for isolating and concentrating flavor and odor-active chemicals...

  2. Characterization of volatiles and identification of odor-active compounds of rocket leaves.

    Science.gov (United States)

    Raffo, Antonio; Masci, Maurizio; Moneta, Elisabetta; Nicoli, Stefano; Sánchez Del Pulgar, José; Paoletti, Flavio

    2018-02-01

    The volatile profile of crushed rocket leaves (Eruca sativa and Diplotaxis tenuifolia) was investigated by applying Headspace Solid-Phase MicroExtraction (HS-SPME), combined with GC-MS, to an aqueous extract obtained by homogenization of rocket leaves, and stabilized by addition of CaCl 2 . A detailed picture of volatile products of the lipoxygenase pathway (mainly C6-aldehydes) and of glucosinolate hydrolysis (mainly isothiocyanates), and their dynamics of formation after tissue disruption was given. Odor-active compounds of leaves were characterized by GC-Olfactometry (GC-O) and Aroma Extract Dilution Analysis (AEDA): volatile isolates obtained by HS-SPME from an aqueous extract and by Stir-Bar Sorptive Extraction (SBSE) from an ethanolic extract were analyzed. The most potent odor-active compounds fully or tentatively identified were (Z)- and (E)-3-hexenal, (Z)-1,5-octadien-3-one, responsible for green olfactory notes, along with 4-mercaptobutyl and 4-(methylthio)butyl isothiocyanate, associated with typical rocket and radish aroma. Relatively high odor potency was observed for 1-octen-3-one, (E)-2-octenal and 1-penten-3-one. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Odorant Receptor Desensitization in Insects

    Directory of Open Access Journals (Sweden)

    Hao Guo

    2017-12-01

    Full Text Available Insects and other arthropods transmit devastating human diseases, and these vectors use chemical senses to target humans. Understanding how these animals detect, respond, and adapt to volatile odorants may lead to novel ways to disrupt host localization or mate recognition in these pests. The past decade has led to remarkable progress in understanding odorant detection in arthropods. Insects use odorant-gated ion channels, first discovered in Drosophila melanogaster , to detect volatile chemicals. In flies, 60 “tuning” receptor subunits combine with a common subunit, Orco ( o dorant r eceptor co receptor to form ligand-gated ion channels. The mechanisms underlying odorant receptor desensitization in insects are largely unknown. Recent work reveals that dephosphorylation of serine 289 on the shared Orco subunit is responsible for slow, odor-induced receptor desensitization. Dephosphorylation has no effect on the localization of the receptor protein, and activation of the olfactory neurons in the absence of odor is sufficient to induce dephosphorylation and desensitization. These findings reveal a major component of receptor modulation in this important group of disease vectors, and implicate a second messenger feedback mechanism in this process.

  4. Piezo-based miniature high resolution stabilized gimbal

    Science.gov (United States)

    Karasikov, Nir; Peled, Gal; Yasinov, Roman; Yetkariov, Rita

    2016-05-01

    Piezo motors are characterized by higher mechanical power density, fast response and direct drive. These features are beneficial for miniature gimbals. A gimbal based on such motors was developed. Diameter is 58 mm, weight is 190 grams. The gimbal carries two cameras: a Flir Quark and an HD day camera. The dynamic performance is as high as 3 rad/sec velocity and 100 rad/secΛ2 acceleration. A two axes stabilization algorithm was developed, yielding 80 micro radian stabilization. Further, a panoramic image capture, at a rate of six stabilized field of views per second, was developed. The manuscript reviews the gimbal structure and open architecture, allowing adaptation to other cameras (SWIR etc.), the control algorithm and presents experimental results of stabilization and of panoramic views taken on a vibration platform and on a UAV.

  5. Equilibrium and stability properties of high-beta torsatrons

    Energy Technology Data Exchange (ETDEWEB)

    Carreras, B.A.; Hicks, H.R.; Holmes, J.A.; Lynch, V.E.; Garcia, L.; Harris, J.H.; Hender, T.C.; Masden, B.F.

    1983-08-01

    Equilibrium and stability properties of high-beta torsatrons have been investigated using numerical and semianalytical techniques based on the method of toroidal averaging. The averaged equilibria have been compared with those obtained using full three-dimensional codes. Good agreement is obtained, thus validating the averaged method approach. We have studied the stability of plamsas for configurations with different aspect ratios and numbers of field periods. The role of the vertical field has also been studied in detail. The main conclusion is that for moderate aspect ratio torsatrons (A/sub p/ less than or equal to 8), the self-stabilizing effect of the magnetic axis shift is large enough to open a direct path to the second stability region.

  6. Distributed representation of social odors indicates parallel processing in the antennal lobe of ants.

    Science.gov (United States)

    Brandstaetter, Andreas Simon; Kleineidam, Christoph Johannes

    2011-11-01

    In colonies of eusocial Hymenoptera cooperation is organized through social odors, and particularly ants rely on a sophisticated odor communication system. Neuronal information about odors is represented in spatial activity patterns in the primary olfactory neuropile of the insect brain, the antennal lobe (AL), which is analog to the vertebrate olfactory bulb. The olfactory system is characterized by neuroanatomical compartmentalization, yet the functional significance of this organization is unclear. Using two-photon calcium imaging, we investigated the neuronal representation of multicomponent colony odors, which the ants assess to discriminate friends (nestmates) from foes (nonnestmates). In the carpenter ant Camponotus floridanus, colony odors elicited spatial activity patterns distributed across different AL compartments. Activity patterns in response to nestmate and nonnestmate colony odors were overlapping. This was expected since both consist of the same components at differing ratios. Colony odors change over time and the nervous system has to constantly adjust for this (template reformation). Measured activity patterns were variable, and variability was higher in response to repeated nestmate than to repeated nonnestmate colony odor stimulation. Variable activity patterns may indicate neuronal plasticity within the olfactory system, which is necessary for template reformation. Our results indicate that information about colony odors is processed in parallel in different neuroanatomical compartments, using the computational power of the whole AL network. Parallel processing might be advantageous, allowing reliable discrimination of highly complex social odors.

  7. A computational study of odorant transport and deposition in the canine nasal cavity: implications for olfaction.

    Science.gov (United States)

    Lawson, M J; Craven, B A; Paterson, E G; Settles, G S

    2012-07-01

    Olfaction begins when an animal draws odorant-laden air into its nasal cavity by sniffing, thus transporting odorant molecules from the external environment to olfactory receptor neurons (ORNs) in the sensory region of the nose. In the dog and other macrosmatic mammals, ORNs are relegated to a recess in the rear of the nasal cavity that is comprised of a labyrinth of scroll-like airways. Evidence from recent studies suggests that nasal airflow patterns enhance olfactory sensitivity by efficiently delivering odorant molecules to the olfactory recess. Here, we simulate odorant transport and deposition during steady inspiration in an anatomically correct reconstructed model of the canine nasal cavity. Our simulations show that highly soluble odorants are deposited in the front of the olfactory recess along the dorsal meatus and nasal septum, whereas moderately soluble and insoluble odorants are more uniformly deposited throughout the entire olfactory recess. These results demonstrate that odorant deposition patterns correspond with the anatomical organization of ORNs in the olfactory recess. Specifically, ORNs that are sensitive to a particular class of odorants are located in regions where that class of odorants is deposited. The correlation of odorant deposition patterns with the anatomical organization of ORNs may partially explain macrosmia in the dog and other keen-scented species.

  8. A new thermocouple with high stability, high reliability and high radioresistance

    International Nuclear Information System (INIS)

    Jiang Xiangying

    1989-01-01

    A new developed NiCrSi/NiSiMg thermocouple alloys and its sheathed thermocouple have high stability, reliability and radio-resistance. Their properties are much better than conventional NiCr/NiAl (type K) thermocouple and some properties are also better than Nicrosil/Nisil (Type N) thermocouple. These new thermocouple alloys and its sheathed thermocouple can be used in scientific research field where high accuracy is need and in nuclear or non-nuclear industries requiring high reliability

  9. Investigation about Role of Algae in Kazeroon Sasan Spring Odor

    Directory of Open Access Journals (Sweden)

    A Hamzeian

    2016-05-01

    Full Text Available Introduction: As odor for potable water is unpleasant for costumers, it needs to do researches for finding the reasons of odorous water. Sasan spring that is located in, near kazeroon city, Fars, Iran, is potable water resource for Kazeroon and Booshehr city and many other villages. Water in Sasan spring has the odor problem. With regards to important   role of algae on ado r problems in this study the role of algae on   odor was investigated. Methods: After regular sampling, the TON (threshold odor number was indicated and algae species was distinguished and the number of total algae and any species  of algae was numbers by microscopic direct numbering method .as the algae mass  is related to nitrogen and phosphor concentration, results of concentration Of nitrogen and phosphor in this spring that was examined regularity by water company was investigated and compared to concentration of these component that are need for algae growing.   Results: results shows that TON was in range  of 4.477 to 6.2 that indicated  oderous limit . Regression and diagram between TON and number of total algae showed the linear relationship. The concentration of nitrogen and phosphor, showed adequate condition for algal grow. Result of determination of algae species showed high population of Oscilatoria and Microcystis species, which are known as essential case of mold odor in water resources. Investigation on geological maps in the region around the Sasan spring, show alluvium source and is effected by surface part of it’s around land. Conclusion: because of the algae was determined as the essential cause of odor   in the spring, and algal growth is related to nutrients, and because of the surface pollution can penetrate in the alluvium lands around the spring, and effect the water in spring, so nutrient control and management is the essential way for odor control in the spring.

  10. High current density aluminum stabilized conductor concepts for space applications

    International Nuclear Information System (INIS)

    Huang, X.; Eyssa, Y.M.; Hilal, M.A.

    1989-01-01

    Lightweight conductors are needed for space magnets to achieve values of E/M (energy stored per unit mass) comparable to the or higher than advanced batteries. High purity aluminum stabilized NbTi composite conductors cooled by 1.8 K helium can provide a winding current density up to 15 kA/cm/sup 2/ at fields up to 10 tesla. The conductors are edge cooled with enough surface area to provide recovery following a normalizing disturbance. The conductors are designed so that current diffusion time in the high purity aluminum is smaller than thermal diffusion time in helium. Conductor design, stability and current diffusion are considered in detail

  11. Stabilized High Power Laser for Advanced Gravitational Wave Detectors

    International Nuclear Information System (INIS)

    Willke, B; Danzmann, K; Fallnich, C; Frede, M; Heurs, M; King, P; Kracht, D; Kwee, P; Savage, R; Seifert, F; Wilhelm, R

    2006-01-01

    Second generation gravitational wave detectors require high power lasers with several 100W of output power and with very low temporal and spatial fluctuations. In this paper we discuss possible setups to achieve high laser power and describe a 200W prestabilized laser system (PSL). The PSL noise requirements for advanced gravitational wave detectors will be discussed in general and the stabilization scheme proposed for the Advanced LIGO PSL will be described. Special emphasis will be given to the most demanding power stabilization requirements and new results (RIN ≤ 4x10 -9 /√Hz) will be presented

  12. Categorical Dimensions of Human Odor Descriptor Space Revealed by Non-Negative Matrix Factorization

    Science.gov (United States)

    Castro, Jason B.; Ramanathan, Arvind; Chennubhotla, Chakra S.

    2013-01-01

    In contrast to most other sensory modalities, the basic perceptual dimensions of olfaction remain unclear. Here, we use non-negative matrix factorization (NMF) – a dimensionality reduction technique – to uncover structure in a panel of odor profiles, with each odor defined as a point in multi-dimensional descriptor space. The properties of NMF are favorable for the analysis of such lexical and perceptual data, and lead to a high-dimensional account of odor space. We further provide evidence that odor dimensions apply categorically. That is, odor space is not occupied homogenously, but rather in a discrete and intrinsically clustered manner. We discuss the potential implications of these results for the neural coding of odors, as well as for developing classifiers on larger datasets that may be useful for predicting perceptual qualities from chemical structures. PMID:24058466

  13. Categorical dimensions of human odor descriptor space revealed by non-negative matrix factorization

    Energy Technology Data Exchange (ETDEWEB)

    Chennubhotla, Chakra [University of Pittsburgh School of Medicine, Pittsburgh PA; Castro, Jason [Bates College

    2013-01-01

    In contrast to most other sensory modalities, the basic perceptual dimensions of olfaction remain un- clear. Here, we use non-negative matrix factorization (NMF) - a dimensionality reduction technique - to uncover structure in a panel of odor profiles, with each odor defined as a point in multi-dimensional descriptor space. The properties of NMF are favorable for the analysis of such lexical and perceptual data, and lead to a high-dimensional account of odor space. We further provide evidence that odor di- mensions apply categorically. That is, odor space is not occupied homogenously, but rather in a discrete and intrinsically clustered manner. We discuss the potential implications of these results for the neural coding of odors, as well as for developing classifiers on larger datasets that may be useful for predicting perceptual qualities from chemical structures.

  14. High beta tokamaks. [MHD equilibrium, stability, and transport calculations

    Energy Technology Data Exchange (ETDEWEB)

    Dory, R.A.; Berger, D.P.; Charlton, L.A.; Hogan, J.T.; Munro, J.K.; Nelson, D.B.; Peng, Y.K.M.; Sigmar, D.J.; Strickler, D.J.

    1978-01-01

    MHD equilibrium, stability, and transport calculations are made to study the accessibility and behavior of ''high beta'' tokamak plasmas in the range ..beta.. approximately 5 to 15 percent. For next generation devices, beta values of at least 8 percent appear to be accessible and stable if there is a conducting surface nearby.

  15. The stability of the High-Density Z-Pinch

    International Nuclear Information System (INIS)

    Glasser, A.H.; Nebel, R.A.

    1989-01-01

    Fiber-initiated High Density Z-Pinches at Los Alamos, NRL, and Karlsruhe have shown anomalously good stability. Kink modes are never seen, and sausage modes are at least delayed until late in the discharge. The success of these devices in reaching fusion conditions may depend on maintaining and understanding this anomalous stability. We have developed two numerical methods to study the stability in the regime where fluid theory is valid. While our methods are applicable to all modes, we will describe them only for the m = 0 sausage mode. The appearance of sausage modes late in the discharge and the total absence of kink modes suggest that an understanding of sausage modes is more urgent, and it is also simpler. 14 refs., 8 figs

  16. Identification of (E,E)-2,4-undecadienal from coriander (Coriandrum sativum L.) as a highly effective deodorant compound against the offensive odor of porcine large intestine.

    Science.gov (United States)

    Ikeura, Hiromi; Kohara, Kaori; Li, Xin-Xian; Kobayashi, Fumiyuki; Hayata, Yasuyoshi

    2010-10-27

    The leaves of coriander ( Coriandrum sativum L.) exhibited a strong deodorizing effect against porcine internal organs (large intestine). The effective deodorizing compounds of coriander were identified by separating the volatile component of coriander, testing the effectiveness of each fraction against the offensive odor of porcine large intestine, and then identifying the compounds by GC-MS. The volatile component of coriander was first separated into six fractions (A-F) by preparative gas chromatography, and the deodorizing activity of each of these fractions against the offensive odor was measured. Fraction D, which showed the strongest deodorizing effect, was then separated into 12 subfractions by preparative GC. The deodorant activity of each subfraction was evaluated, and the deodorant compounds were identified by GC-MS. It was discovered that (E,E)-2,4-undecadienal was the most effective deodorizing compound. The deodorizing activity of (E,E)-2,4-undecadienal on the porcine large intestine increased as with concentration, reaching almost complete deodorizing ability at 10 ppb.

  17. Odor Classification using Agent Technology

    Directory of Open Access Journals (Sweden)

    Sigeru OMATU

    2014-03-01

    Full Text Available In order to measure and classify odors, Quartz Crystal Microbalance (QCM can be used. In the present study, seven QCM sensors and three different odors are used. The system has been developed as a virtual organization of agents using an agent platform called PANGEA (Platform for Automatic coNstruction of orGanizations of intElligent Agents. This is a platform for developing open multi-agent systems, specifically those including organizational aspects. The main reason for the use of agents is the scalability of the platform, i.e. the way in which it models the services. The system models functionalities as services inside the agents, or as Service Oriented Approach (SOA architecture compliant services using Web Services. This way the adaptation of the odor classification systems with new algorithms, tools and classification techniques is allowed.

  18. Odors enhance visual attention to congruent objects.

    Science.gov (United States)

    Seo, Han-Seok; Roidl, Ernst; Müller, Friedrich; Negoias, Simona

    2010-06-01

    Although it is well known that visual stimuli affect olfactory performance, little is known about the reverse case: the influence of odor on visual performance. This study aimed to determine whether odors can enhance attention towards visually presented objects congruent with the odors. Sixty healthy participants were presented with four odors (orange, lavender, coffee, and liquorice) before and during the presentation of photographic slides containing one congruent and three incongruent objects with the presented odors. The participants' visual attention was assessed as the total number and time of eye fixations by using an eye tracking system. When the participants smelled an odor, they looked more frequently and longer at a corresponding object as compared to the odorless condition. In conclusion, our findings demonstrate for the first time an olfactory priming effect on visual selective attention: odor can increase attention towards a congruent visual object as compared to a non-odor condition. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. Ideal MHD stability of high poloidal beta equilibria in TFTR

    International Nuclear Information System (INIS)

    Sabbagh, S.A.; Mauel, M.E.; Navratil, G.A.; Bell, M.G.; Budny, R.V.; Chance, M.S.; Fredrickson, E.D.; Jardin, S.C.; Manickam, J.; McCune, D.C.; McGuire, K.M.; Wieland, R.M.; Zarnstorff, M.C.; Phillips, M.W.; Hughes, M.H.; Kesner, J.

    1991-01-01

    Recent experiments in TFTR have expanded the operating space of the device to include plasmas with values of var-epsilon β p dia ≡ 2μ 0 var-epsilon perpendicular >/ p >> 2 as large as 1.6, and Troyon normalized diamagnetic beta β N dia ≡ β t perpendicular aB t /10 -8 I p as large as 4.7. At values of var-epsilon β p dia ≥ 1.3, a separatrix was observed to enter the vacuum vessel, producing a naturally diverted discharge. Plasmas with large values of var-epsilon β p dia were created with both the plasma current, I p , held constant and with I p decreased, or ramped down, before the start of neutral beam injection. A convenient characterization of the change in I p using experimental parameters can be defined by the ratio of I p before the ramp down, to I p during the neutral beam heating phase, F I p . The ideal MHD stability of these equilibria is investigated to determine their location in stability space, and to study the role of plasma current and pressure profile modification in the creation of these high var-epsilon β p and β N plasmas. The evolution of these plasmas is modelled from experimental data using the TRANSP code. Two-dimensional equilibria are computed from the TRANSP results and used as input to both high and low-n stability codes including PEST. The high var-epsilon β p equilibria, which generally have an oblate cross-sectional shape, are in the first stability region to high-n ballooning modes. At constant I p , these equilibria generally have maximum pressure gradients near the magnetic axis and are stable to n=1 modes without a stabilizing conducting wall. The effect of the current profile shape on the stability of low-n kink/ballooning modes and the requirements for these plasmas to access the second stability region are examined. 6 refs

  20. Effects of odor generated from the glycine/glucose Maillard reaction on human mood and brainwaves.

    Science.gov (United States)

    Zhou, Lanxi; Ohata, Motoko; Arihara, Keizo

    2016-06-15

    Effects of the odor generated from the glycine/glucose Maillard reaction on human mood and brainwaves were investigated in the present study. Equimolar solutions of glucose and glycine were adjusted to pH 7 and pH 9 and heated at 90 °C for 30 min. The odor generated from the glycine/glucose Maillard reaction significantly decreased negative moods. Its effects on brainwaves differed according to pH; alpha brainwave distribution was increased after inhalation of the odor generated at pH 7, whereas it was decreased by the odor generated at pH 9. The effects on mood and brainwaves were also measured after inhalation of model solutions, which comprised of potent odorants determined by aroma extract dilution analysis (AEDA), and the results were similar to those obtained with the Maillard reaction samples. Therefore, odors constructed by potent odorants could influence human mood and brainwaves. Among all potent odorants, 2,3-dimethylpyrazine and 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) were identified as the strongest, and high pH values resulted in higher yields of these odorants. Furthermore, DMHF was identified as the putative agent responsible for the decrease in alpha brainwave distribution after smelling the pH-9 Maillard reaction sample since higher concentrations of DMHF resulted in a similar effect.

  1. Synthesis of biolubricants with high viscosity and high oxidation stability

    Directory of Open Access Journals (Sweden)

    Bondioli Paolo

    2003-03-01

    Full Text Available The synthetic procedure as well as the main properties of obtained products of a group of complex esters are reported here. Complex esters were prepared using low molecular weight saturated fatty acids, trimethylolpropane and a dicarboxylic acid as a feedstock. By means of this procedure it is possible to obtain products having high viscosity and very good lubricating, thermal and cold properties. Thanks to the absence of unsaturations into the ester also the oxidation property is good, opening several application perspective for these products which are partly prepared from renewable source.

  2. High gain proportional rf control stability at TESLA cavities

    Directory of Open Access Journals (Sweden)

    Elmar Vogel

    2007-05-01

    Full Text Available Fast proportional rf control is used as the basis for rf field regulation in actual linear accelerator projects like the international linear collider (ILC and the European x-ray free electron laser (XFEL based on TESLA technology. Additional control loops improve the field regulation by treating repetitive effects and compensating the beam loading. Nevertheless, the ability for high gain operation of the fast loops is desirable for the strong suppression of nonpredictive and nonrepetitive disturbances. TESLA cavities host nine fundamental modes (FMs where only one is used for beam acceleration. The unwanted FMs have a significant influence on the proportional rf control loop stability at high gains. Within this paper, the stability of proportional rf control loops taking the FMs and digitalization effects into account will be discussed in detail together with measures enabling a significant increase of the gain values.

  3. Impact of ambient odors on food intake, saliva production and appetite ratings.

    Science.gov (United States)

    Proserpio, Cristina; de Graaf, Cees; Laureati, Monica; Pagliarini, Ella; Boesveldt, Sanne

    2017-05-15

    The aim of this study was to investigate the effect of ambient odor exposure on appetite, salivation and food intake. 32 normal-weight young women (age: 21.4±5.3year; BMI: 21.7±1.9kg/m 2 ) attended five test sessions in a non-satiated state. Each participant was exposed to ambient odors (chocolate, beef, melon and cucumber), in a detectable but mild concentration, and to a control condition (no-odor exposure). During each condition, at different time points, participants rated appetite for 15 food products, and saliva was collected. After approximately 30min, ad libitum intake was measured providing a food (chocolate rice, high-energy dense product) that was congruent with one of the odors they were exposed to. A significant odor effect on food intake (p=0.034) and salivation (p=0.017) was found. Exposure to odors signaling high-energy dense products increased food intake (243.97±22.84g) compared to control condition (206.94±24.93g; p=0.03). Consistently, salivation was increased significantly during chocolate and beef exposure (mean: 0.494±0.050g) compared to control condition (0.417±0.05g; p=0.006). Even though odor exposure did not induce specific appetite for congruent products (p=0.634), appetite scores were significantly higher during odor exposure (p<0.0001) compared to the no-odor control condition and increased significantly over time (p=0.010). Exposure to food odors seems to drive behavioral and physiological responses involved in eating behavior, specifically for odors and foods that are high in energy density. This could have implications for steering food intake and ultimately influencing the nutritional status of people. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Stabilization void-fill encapsulation high-efficiency particulate filters

    International Nuclear Information System (INIS)

    Alexander, R.G.; Stewart, W.E.; Phillips, S.J.; Serkowski, M.M.; England, J.L.; Boynton, H.C.

    1994-05-01

    This report discusses high-efficiency particulate air (HEPA) filter systems that which are contaminated with radionuclides are part of the nuclear fuel processing systems conducted by the US Department of Energy (DOE) and require replacement and safe and efficient disposal for plant safety. Two K-3 HEPA filters were removed from service, placed burial boxes, buried, and safely and efficiently stabilized remotely which reduced radiation exposure to personnel and the environment

  5. High performance solid acid fuel cells through humidity stabilization

    OpenAIRE

    Boysen, Dane A.; Uda, Tetsuya; Chisholm, Calum R. I.; Haile, Sossina M.

    2004-01-01

    Although they hold the promise of clean energy, state-of-the-art fuel cells based on polymer electrolyte membrane fuel cells are inoperable above 100°C, require cumbersome humidification systems, and suffer from fuel permeation. These difficulties all arise from the hydrated nature of the electrolyte. In contrast, “solid acids” exhibit anhydrous proton transport and high-temperature stability. We demonstrate continuous, stable power generation for both H_2/O_2 and direct methanol fuel cells o...

  6. Internal Representation and Memory Formation of Odor Preference Based on Oscillatory Activities in a Terrestrial Slug

    Science.gov (United States)

    Sekiguchi, Tatsuhiko; Furudate, Hiroyuki; Kimura, Tetsuya

    2010-01-01

    The terrestrial slug "Limax" exhibits a highly developed ability to learn odors with a small nervous system. When a fluorescent dye, Lucifer Yellow (LY), is injected into the slug's body cavity after odor-taste associative conditioning, a group of neurons in the procerebral (PC) lobe, an olfactory center of the slug, is labeled by LY. We examined…

  7. Differential odor processing in two olfactory pathways in the honeybee

    Directory of Open Access Journals (Sweden)

    Nobuhiro Yamagata

    2009-12-01

    Full Text Available An important component in understanding central olfactory processing and coding in the insect brain relates to the characterization of the functional divisions between morphologically distinct types of projection neurons (PN. Using calcium imaging, we investigated how the identity, concentration and mixtures of odors are represented in axon terminals (boutons of two types of PNs - lPN and mPN. In lPN boutons we found less concentration dependence, narrow tuning profiles at a high concentration, which may be optimized for fine, concentration-invariant odor discrimination. In mPN boutons, however, we found clear rising concentration dependence, broader tuning profiles at a high concentration, which may be optimized for concentration coding. In addition, we found more mixture suppression in lPNs than in mPNs, indicating lPNs better adaptation for synthetic mixture processing. These results suggest a functional division of odor processing in both PN types.

  8. Process Design Concepts for Stabilization of High Level Waste Calcine

    Energy Technology Data Exchange (ETDEWEB)

    T. R. Thomas; A. K. Herbst

    2005-06-01

    The current baseline assumption is that packaging ¡§as is¡¨ and direct disposal of high level waste (HLW) calcine in a Monitored Geologic Repository will be allowed. The fall back position is to develop a stabilized waste form for the HLW calcine, that will meet repository waste acceptance criteria currently in place, in case regulatory initiatives are unsuccessful. A decision between direct disposal or a stabilization alternative is anticipated by June 2006. The purposes of this Engineering Design File (EDF) are to provide a pre-conceptual design on three low temperature processes under development for stabilization of high level waste calcine (i.e., the grout, hydroceramic grout, and iron phosphate ceramic processes) and to support a down selection among the three candidates. The key assumptions for the pre-conceptual design assessment are that a) a waste treatment plant would operate over eight years for 200 days a year, b) a design processing rate of 3.67 m3/day or 4670 kg/day of HLW calcine would be needed, and c) the performance of waste form would remove the HLW calcine from the hazardous waste category, and d) the waste form loadings would range from about 21-25 wt% calcine. The conclusions of this EDF study are that: (a) To date, the grout formulation appears to be the best candidate stabilizer among the three being tested for HLW calcine and appears to be the easiest to mix, pour, and cure. (b) Only minor differences would exist between the process steps of the grout and hydroceramic grout stabilization processes. If temperature control of the mixer at about 80„aC is required, it would add a major level of complexity to the iron phosphate stabilization process. (c) It is too early in the development program to determine which stabilizer will produce the minimum amount of stabilized waste form for the entire HLW inventory, but the volume is assumed to be within the range of 12,250 to 14,470 m3. (d) The stacked vessel height of the hot process vessels

  9. Novel active stabilization technology in highly crosslinked UHMWPEs for superior stability

    Science.gov (United States)

    Oral, Ebru; Neils, Andrew L.; Wannomae, Keith K.; Muratoglu, Orhun K.

    2014-12-01

    Radiation cross-linked ultrahigh molecular weight polyethylene (UHMWPE) is the bearing of choice in joint arthroplasty. The demands on the longevity of this polymer are likely to increase with the recently advancing deterioration of the performance of alternative metal-on-metal implants. Vitamin E-stabilized, cross-linked UHMWPEs are considered the next generation of improved UHMWPE bearing surfaces for improving the oxidation resistance of the polymer. It was recently discovered that in the absence of radiation-induced free radicals, lipids absorbed into UHMWPE from the synovial fluid can initiate oxidation and result in new free radical-mediated oxidation mechanisms. In the presence of radiation-induced free radicals, it is possible for the polymer to oxidize through both existing free radicals at the time of implantation and through newly formed free radicals in vivo. Thus, we showed that reducing the radiation-induced free radicals in vitamin E-stabilized UHMWPE would increase its oxidative stability and presumably lead to improved longevity. We describe mechanical annealing and warm irradiation of irradiated vitamin E blends as novel methods to eliminate 99% of radiation-induced free radicals without sacrificing crystallinity. These are significant improvements in the processing of highly cross-linked UHMWPE for joint implants with improved longevity.

  10. An extremely high stability cooling system for planet hunter

    Science.gov (United States)

    l’Allemand, J. L. Lizon a.; Becerril, S.; Mirabet, E.

    2017-12-01

    The detection of exoplanets is done by measuring very tiny periodical variations of the radial velocity of the parent star. Extremely stable spectrographs are required in order to enhance the wavelength variations of the spectral lines due to Doppler effect. CARMENES is the new high-resolution, high-stability spectrograph built for the 3.5 m telescope at the Calar Alto Observatory (CAHA, Almería, Spain) by a consortium formed by German and Spanish institutions. This instrument is composed of two separated spectrographs: VIS channel (550-1050 nm) and NIR channel (950-1700 nm). The NIR-channel spectrograph’s has been built under the responsibility of the Instituto de Astrofísica de Andalucía (IAA-CSIC). It has been manufactured, assembled, integrated and verified in the last two years, delivered in fall 2015 and commissioned in December 2015. Beside the various opto-mechanical challenges, the cooling system was one of the most demanding sub-systems of the NIR channel. Due to the highly demanding requirements applicable in terms of stability, this system arises as one of the core systems to provide outstanding stability to the channel at an operating temperature finally fixed at 140 K. Really at the edge of the state-of-the-art, the Cooling System is able to provide to the cold mass (∼1 Ton) better thermal stability than few hundredths of a degree over 24 hours (goal: 0.01K/day). The present paper describes the main technical approach, which has been taken in order to reach this very ambitious performance.

  11. Unexpected plant odor responses in a moth pheromone system

    Directory of Open Access Journals (Sweden)

    Angéla eRouyar

    2015-05-01

    Full Text Available Male moths rely on olfactory cues to find females for reproduction. Males also use volatile plant compounds (VPCs to find food sources and might use host-plant odor cues to identify the habitat of calling females. Both the sex pheromone released by conspecific females and VPCs trigger well-described oriented flight behavior towards the odor source. Whereas detection and central processing of pheromones and VPCs have been thought for a long time to be highly separated from each other, recent studies have shown that interactions of both types of odors occur already early at the periphery of the olfactory pathway. Here we show that detection and early processing of VPCs and pheromone can overlap between the two sub-systems. Using complementary approaches, i.e. single-sensillum recording of olfactory receptor neurons, in vivo calcium imaging in the antennal lobe, intracellular recordings of neurons in the macroglomerular complex (MGC and flight tracking in a wind tunnel, we show that some plant odorants alone, such as heptanal, activate the pheromone-specific pathway in male Agrotis ipsilon at peripheral and central levels. To our knowledge, this is the first report of a plant odorant with no chemical similarity to the molecular structure of the pheromone, acting as a partial agonist of a moth sex pheromone.

  12. Context odor presentation during sleep enhances memory in honeybees.

    Science.gov (United States)

    Zwaka, Hanna; Bartels, Ruth; Gora, Jacob; Franck, Vivien; Culo, Ana; Götsch, Moritz; Menzel, Randolf

    2015-11-02

    Sleep plays an important role in stabilizing new memory traces after learning [1-3]. Here we investigate whether sleep's role in memory processing is similar in evolutionarily distant species and demonstrate that a context trigger during deep-sleep phases improves memory in invertebrates, as it does in humans. We show that in honeybees (Apis mellifera), exposure to an odor during deep sleep that has been present during learning improves memory performance the following day. Presentation of the context odor during wake phases or novel odors during sleep does not enhance memory. In humans, memory consolidation can be triggered by presentation of a context odor during slow-wave sleep that had been present during learning [3-5]. Our results reveal that deep-sleep phases in honeybees have the potential to prompt memory consolidation, just as they do in humans. This study provides strong evidence for a conserved role of sleep-and how it affects memory processes-from insects to mammals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Simulation of silicon nanoparticles stabilized by hydrogen at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Galashev, Alexander Y., E-mail: galashev@ecko.uran.r [Russian Academy of Sciences, Ural Division, Institute of Industrial Ecology (Russian Federation)

    2010-10-15

    The stability of different silicon nanoparticles are investigated at a high temperature. The temperature dependence of the physicochemical properties of 60- and 73-atom silicon nanoparticles are investigated using the molecular dynamics method. The 73-atom particles have a crystal structure, a random atomic packing, and a packing formed by inserting a 13-atom icosahedron into a 60-atom fullerene. They are surrounded by a 'coat' from 60 atoms of hydrogen. The nanoassembled particle at the presence of a hydrogen 'coat' has the most stable number (close to four) of Si-Si bonds per atom. The structure and kinetic properties of a hollow single-layer fullerene-structured Si{sub 60} cluster are considered in the temperature range 10 K {<=} T {<=} 1760 K. Five series of calculations are conducted, with a simulation of several media inside and outside the Si{sub 60} cluster, specifically, the vacuum and interior spaces filled with 30 and 60 hydrogen atoms with and without the exterior hydrogen environment of 60 atoms. Fullerene surrounded by a hydrogen 'coat' and containing 60 hydrogen atoms in the interior space has a higher stability. Such cluster has smaller self-diffusion coefficients at high temperatures. The fullerene stabilized with hydrogen is stable to the formation of linear atomic chains up to the temperatures 270-280 K.

  14. Effects of extraneous odors on canine detection

    Science.gov (United States)

    Waggoner, L. Paul; Jones, Meredith H.; Williams, Marc; Johnston, J. M.; Edge, Cindy C.; Petrousky, James A.

    1998-12-01

    Dogs are often required to detect target substances under challenging conditions. One of these challenges is to detect contraband in the presence of extraneous odors, whether they are part of the ambient environment or placed there for the purpose of evading detection. This paper presents the results of two studies evaluating the ability of dogs to detect target substances in the presence of varying concentrations of extraneous odors. The studies were conducted under behavioral laboratory conditions, providing good control over vapor sources and a clear basis for evaluation of detection responses. Dogs were trained to sample an air stream consisting of the extraneous odor only or the extraneous odor plus the target odor and then press the appropriate lever to earn food. The results are described in terns of the ability of dogs to detect target odors in the presence of a wide range of concentrations of the extraneous odors.

  15. Production for high thermal stability NdFeB magnets

    Energy Technology Data Exchange (ETDEWEB)

    Yu, L.Q. [College of Physics Science and Technology, China University of Petroleum (East China), Dongying 257061, Shandong Province (China)], E-mail: iyy2000@163.com; Zhang, J.; Hu, S.Q.; Han, Z.D. [College of Physics Science and Technology, China University of Petroleum (East China), Dongying 257061, Shandong Province (China); Yan, M. [State Key Lab of Silicon Materials, Zhejiang University, Hangzhou 310027 (China)

    2008-04-15

    To improve sintered NdFeB magnets' thermal stability and magnetic properties, combined addition of elements Cu and Gd was investigated. It was found that with Gd addition increase to 1.0%, the temperature coefficient {alpha} improved from -0.15 to -0.05%/deg. C (maximum working temperature 120 deg. C), but the remanence and the maximum energy product linearly decreased. With addition of Cu in Gd-containing magnets the intrinsic coercivity increased greatly, and the remanence increased also because of their density improvement, and optimum Cu content was achieved at 0.2%. Microstructure analysis showed that most of the Cu distributed at grain boundaries and led to clear and smooth morphologies. Magnets with high thermal stability {alpha}=-0.05%/deg. C and magnetic properties were obtained with addition of Gd=0.8% and Cu=0.2%.

  16. Cementitious Stabilization of Mixed Wastes with High Salt Loadings

    Energy Technology Data Exchange (ETDEWEB)

    Spence, R.D.; Burgess, M.W.; Fedorov, V.V.; Downing, D.J.

    1999-04-01

    Salt loadings approaching 50 wt % were tolerated in cementitious waste forms that still met leach and strength criteria, addressing a Technology Deficiency of low salt loadings previously identified by the Mixed Waste Focus Area. A statistical design quantified the effect of different stabilizing ingredients and salt loading on performance at lower loadings, allowing selection of the more effective ingredients for studying the higher salt loadings. In general, the final waste form needed to consist of 25 wt % of the dry stabilizing ingredients to meet the criteria used and 25 wt % water to form a workable paste, leaving 50 wt % for waste solids. The salt loading depends on the salt content of the waste solids but could be as high as 50 wt % if all the waste solids are salt.

  17. Phase stability of high manganese austenitic steels for cryogenic applications

    CERN Document Server

    Couturier, K

    2000-01-01

    The aim of this work is to study the austenitic stability against a' martensitic transformation of three non-magnetic austenitic steels : a new stainless steel X2CrMnNiMoN 19-12-11-1 grade, a traditional X8CrMnNiN 19-11-6 grade and a high manganese X8MnCrNi 28-7-1 grade. Measurements of relative magnetic susceptibility at room temperature are performed on strained tensile specimens at 4.2 K. A special extensometer for high precision strain measurements at low temperature has been developed at CERN to test specimens up to various levels of plastic strain. Moreover, the high precision strain recording of the extensometer enables a detailed study of the serrated yield phenomena associated with 4.2 K tensile testing and their influence on the evolution of magnetic susceptibility. The results show that high Mn contents increase the stability of the austenitic structure against a' martensitic transformation, while keeping high strength at cryogenic temperature. Moreover, proper elaboration through primary and possi...

  18. Coincidence of pheromone and plant odor leads to sensory plasticity in the heliothine olfactory system.

    Directory of Open Access Journals (Sweden)

    Elena Ian

    Full Text Available Male moths possess a highly specialized olfactory system comprised of two segregated sub-arrangements dedicated to processing information about plant odors and pheromones, respectively. Communication between these two sub-systems has been described at the peripheral level, but relatively little is known about putative interactions at subsequent synaptic relays. The male moth faces the challenge of seeking out the conspecific female in a highly dynamic odor world. The female-produced pheromone blend, which is a limited resource serving as guidance for the male, will reach his antennae in intermittent pockets of odor filaments mixed with volatiles from various plants. In the present study we performed calcium imaging for measuring odor-evoked responses in the uni-glomerular antennal-lobe projection neurons (analog to mitral cells in the vertebrate olfactory bulb of Helicoverpa armigera. In order to investigate putative interactions between the two sub-systems tuned to plant volatiles and pheromones, respectively, we performed repeated stimulations with a selection of biologically relevant odors. We found that paired stimulation with a plant odor and the pheromone led to suppressed responses in both sub-systems as compared to those evoked during initial stimulation including application of each odor stimulus alone. The fact that the suppression persisted also after pairing, indicates the existence of a Hebbian-like plasticity in the primary olfactory center established by temporal pairing of the two odor stimulation categories.

  19. Phase Stability Diagrams for High Temperature Corrosion Processes

    Directory of Open Access Journals (Sweden)

    J. J. Ramos-Hernandez

    2013-01-01

    Full Text Available Corrosion phenomena of metals by fused salts depend on chemical composition of the melt and environmental conditions of the system. Detail knowledge of chemistry and thermodynamic of aggressive species formed during the corrosion process is essential for a better understanding of materials degradation exposed to high temperature. When there is a lack of kinetic data for the corrosion processes, an alternative to understand the thermodynamic behavior of chemical species is to utilize phase stability diagrams. Nowadays, there are several specialized software programs to calculate phase stability diagrams. These programs are based on thermodynamics of chemical reactions. Using a thermodynamic data base allows the calculation of different types of phase diagrams. However, sometimes it is difficult to have access to such data bases. In this work, an alternative way to calculate phase stability diagrams is presented. The work is exemplified in the Na-V-S-O and Al-Na-V-S-O systems. This system was chosen because vanadium salts is one of the more aggressive system for all engineering alloys, especially in those processes where fossil fuels are used.

  20. Elaborated Odor Test for Extended Exposure

    Science.gov (United States)

    Buchanan, Vanessa D.; Henry, Emily J.; Mast, Dion J.; Harper, Susana A.; Beeson, Harold D.; Tapia, Alma S.

    2016-01-01

    Concerns were raised when incidental exposure to a proprietary bonding material revealed the material had an irritating odor. The NASA-STD-6001B document describes a supplemental test method option for programs to evaluate materials with odor concerns (Test 6, Odor Assessment). In addition to the supplemental standard odor assessment with less than 10 seconds of exposure, the NASA White Sands Test Facility (WSTF) Materials Flight Acceptance Testing section was requested to perform an odor test with an extended duration to evaluate effects of an extended exposure and to more closely simulate realistic exposure scenarios. With approval from the NASA Johnson Space Center Industrial Hygienist, WSTF developed a 15-minute odor test method. WSTF performed this extended-duration odor test to evaluate the odor and physical effects of the bonding material configured between two aluminum plates, after the safety of the gas was verified via toxicity analysis per NASA-STD-6001B Test 7, Determination of Offgassed Products. During extended-duration testing, odor panel members were arranged near the test material in a small room with the air handlers and doors closed to minimize dilution. The odor panel members wafted gas toward themselves and recorded their individual assessments of odor and physical effects at various intervals during the 15-minute exposure and posttest. A posttest interview was conducted to obtain further information. Testing was effective in providing data for comparison and selection of an optimal offgassing and odor containment configuration. The developed test method for extended exposure is proposed as a useful tool for further evaluating materials with identified odors of concern if continued use of the material is anticipated.

  1. Influence of the chemical structure on odor qualities and odor thresholds of halogenated guaiacol-derived odorants

    Science.gov (United States)

    Juhlke, Florian; Lorber, Katja; Wagenstaller, Maria; Buettner, Andrea

    2017-12-01

    Chlorinated guaiacol derivatives are found in waste water of pulp mills using chlorine in the bleaching process of wood pulp. They can also be detected in fish tissue, possibly causing off-odors. To date, there is no systematic investigation on the odor properties of halogenated guaiacol derivatives. To close this gap, odor thresholds in air and odor qualities of 14 compounds were determined by gas chromatography-olfactometry. Overall, the investigated compounds elicited smells that are characteristic for guaiacol, namely smoky, sweet, vanilla-like, but also medicinal and plaster-like. Their odor thresholds in air were, however, very low, ranging from 0.00072 to 23 ng/Lair. The lowest thresholds were found for 5-chloro- and 5-bromoguaiacol, followed by 4,5-dichloro- and 6-chloroguaiacol. Moreover, some inter-individual differences in odor threshold values could be observed, with the highest variations having been recorded for the individual values of 5-iodo- and 4-bromoguaiacol.

  2. Dynamic Stability Analysis Using High-Order Interpolation

    Directory of Open Access Journals (Sweden)

    Juarez-Toledo C.

    2012-10-01

    Full Text Available A non-linear model with robust precision for transient stability analysis in multimachine power systems is proposed. The proposed formulation uses the interpolation of Lagrange and Newton's Divided Difference. The High-Order Interpolation technique developed can be used for evaluation of the critical conditions of the dynamic system.The technique is applied to a 5-area 45-machine model of the Mexican interconnected system. As a particular case, this paper shows the application of the High-Order procedure for identifying the slow-frequency mode for a critical contingency. Numerical examples illustrate the method and demonstrate the ability of the High-Order technique to isolate and extract temporal modal behavior.

  3. Stability analysis of the high performance light water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ortega Gomez, Tino

    2009-03-15

    In the Generation IV international advanced nuclear reactor development program, the High Performance Light Water Reactor (HPLWR) is one of the most promising candidates. Important features are its inherently high thermodynamic efficiency (of approximately 45 %) and the ability to use existing supercritical water technology which previously has been developed and deployed for fossil fired power plants. Within a HPLWR core, the fluid experiences a drastic change in thermal and transport properties such as density, dynamic viscosity, specific heat and thermal conductivity, as the supercritical water is heated from 280 C to 500 C. The density change substantially exceeds that in a Boiling Water Reactor (i.e., HPLWR: density changes from 780 kg/m{sup 3} to 90 kg/m{sup 3}; BWR: density changes from 750 kg/m{sup 3} to 198 kg/m3). Due to this density change, the HPLWR can be - under certain operation parameters - susceptible to various thermal-hydraulic flow instabilities, which have to be avoided. In this thesis a stability analysis for the HPLWR is presented. This analysis is based on analytical considerations and numerical results, which were obtained by a computer code developed by the author. The heat-up stages of the HPLWR three-pass core are identified in respect to the relevant flow instability phenomena. The modeling approach successfully used for BWR stability analysis is extended to supercritical pressure operation conditions. In particular, a one-dimensional equation set representing the coolant flow of HPLWR fuel assemblies has been implemented in a commercial software named COMSOL to perform steady-state, time-dependent, and modal analyses. An investigation of important static instabilities (i.e., Ledinegg instabilities, flow maldistribution) and Pressure Drop Oscillations (PDO) have been carried out and none were found under operation conditions of the HPLWR. Three types of Density Wave Oscillation (DWO) modes have been studied: the single channel DWO, the

  4. Perception of odors linked to precise timing in the olfactory system.

    Directory of Open Access Journals (Sweden)

    Michelle R Rebello

    2014-12-01

    Full Text Available While the timing of neuronal activity in the olfactory bulb (OB relative to sniffing has been the object of many studies, the behavioral relevance of timing information generated by patterned activation within the bulbar response has not been explored. Here we show, using sniff-triggered, dynamic, 2-D, optogenetic stimulation of mitral/tufted cells, that virtual odors that differ by as little as 13 ms are distinguishable by mice. Further, mice are capable of discriminating a virtual odor movie based on an optically imaged OB odor response versus the same virtual odor devoid of temporal dynamics-independently of the sniff-phase. Together with studies showing the behavioral relevance of graded glomerular responses and the response timing relative to odor sampling, these results imply that the mammalian olfactory system is capable of very high transient information transmission rates.

  5. How Far Does a Receptor Influence Vibrational Properties of an Odorant?

    Science.gov (United States)

    Reese, Anna; List, Nanna Holmgaard; Kongsted, Jacob; Solov'yov, Ilia A

    2016-01-01

    The biophysical mechanism of the sense of smell, or olfaction, is still highly debated. The mainstream explanation argues for a shape-based recognition of odorant molecules by olfactory receptors, while recent investigations suggest the primary olfactory event to be triggered by a vibrationally-assisted electron transfer reaction. We consider this controversy by studying the influence of a receptor on the vibrational properties of an odorant in atomistic details as the coupling between electronic degrees of freedom of the receptor and the vibrations of the odorant is the key parameter of the vibrationally-assisted electron transfer. Through molecular dynamics simulations we elucidate the binding specificity of a receptor towards acetophenone odorant. The vibrational properties of acetophenone inside the receptor are then studied by the polarizable embedding density functional theory approach, allowing to quantify protein-odorant interactions. Finally, we judge whether the effects of the protein provide any indications towards the existing theories of olfaction.

  6. High Volume Manufacturing and Field Stability of MEMS Products

    Science.gov (United States)

    Martin, Jack

    Low volume MEMS/NEMS production is practical when an attractive concept is implemented with business, manufacturing, packaging, and test support. Moving beyond this to high volume production adds requirements on design, process control, quality, product stability, market size, market maturity, capital investment, and business systems. In a broad sense, this chapter uses a case study approach: It describes and compares the silicon-based MEMS accelerometers, pressure sensors, image projection systems, and gyroscopes that are in high volume production. Although they serve several markets, these businesses have common characteristics. For example, the manufacturing lines use automated semiconductor equipment and standard material sets to make consistent products in large quantities. Standard, well controlled processes are sometimes modified for a MEMS product. However, novel processes that cannot run with standard equipment and material sets are avoided when possible. This reliance on semiconductor tools, as well as the organizational practices required to manufacture clean, particle-free products partially explains why the MEMS market leaders are integrated circuit manufacturers. There are other factors. MEMS and NEMS are enabling technologies, so it can take several years for high volume applications to develop. Indeed, market size is usually a strong function of price. This becomes a vicious circle, because low price requires low cost - a result that is normally achieved only after a product is in high volume production. During the early years, IC companies reduced cost and financial risk by using existing facilities for low volume MEMS production. As a result, product architectures are partially determined by capabilities developed for previous products. This chapter includes a discussion of MEMS product architecture with particular attention to the impact of electronic integration, packaging, and surfaces. Packaging and testing are critical, because they are

  7. Insect Repellents: Modulators of Mosquito Odorant Receptor Activity

    Science.gov (United States)

    2010-08-01

    herbivorous insects [8] and was shown to have mosquito repellent properties at high concentrations [9]. In 2007, 2-U was incorporated in the insect...KJ, Vosshall LB (2005) Functional conservation of an insect odorant receptor gene across 250 million years of evolution . Curr Biol 15: R119–121. 27

  8. The relationship between chemical concentration and odor activity value explains the inconsistency in making a comprehensive surrogate scent training tool representative of illicit drugs.

    Science.gov (United States)

    Rice, Somchai; Koziel, Jacek A

    2015-12-01

    This report highlights the importance of an individual chemical's odor impact in the olfactory identification of marijuana, cocaine, and heroin. There are small amounts of highly odorous compounds present in headspace of these drugs, with very low odor detection thresholds, that are more likely responsible for contributing to the overall odor of these drugs. Previous reports of the most abundant compounds in headspace can mislead researchers when dealing with whole odor of these drugs. Surrogate scent formulations, therefore, must match the odor impact of key compounds and not just the chemical abundance of compounds. The objective of this study was to compare odorous volatile organic compounds (VOCs) emitted from illicit drug samples of marijuana, cocaine, and heroin to surrogate smell formulations using simultaneous sensory (via human olfaction) and chemical analyses. Use of solid phase microextraction (SPME) allowed VOCs in drug headspace to be extracted and pre-concentrated on site, and analyzed by multidimensional gas chromatography-mass spectrometry-olfactometry (MDGC-MS-O). Use of MDGC-MS-O allowed for further separation of odorous compounds and simultaneous detection by the human nose of the separate odor parts that make up the total aroma of these drugs. The compounds most abundant in headspace were not the most odor impactful when ranked by odor activity values (OAVs) (defined as ratio of concentration to odor detection threshold, ODT). There were no apparent correlations between concentrations and OAVs. A 1g marijuana surrogate lacked in odor active acids, aldehydes, ethers, hydrocarbons, N-containing, and S-containing VOCs and was overabundant in odor active alcohols and aromatics compared with real marijuana. A 1g cocaine surrogate was overabundant in odor active alcohols, aldehydes, aromatics, esters, ethers, halogenates, hydrocarbons, ketones and N-containing compounds compared with real. A 1g heroin surrogate should contain less odor active acids

  9. Cross-cultural color-odor associations.

    Directory of Open Access Journals (Sweden)

    Carmel A Levitan

    Full Text Available Colors and odors are associated; for instance, people typically match the smell of strawberries to the color pink or red. These associations are forms of crossmodal correspondences. Recently, there has been discussion about the extent to which these correspondences arise for structural reasons (i.e., an inherent mapping between color and odor, statistical reasons (i.e., covariance in experience, and/or semantically-mediated reasons (i.e., stemming from language. The present study probed this question by testing color-odor correspondences in 6 different cultural groups (Dutch, Netherlands-residing-Chinese, German, Malay, Malaysian-Chinese, and US residents, using the same set of 14 odors and asking participants to make congruent and incongruent color choices for each odor. We found consistent patterns in color choices for each odor within each culture, showing that participants were making non-random color-odor matches. We used representational dissimilarity analysis to probe for variations in the patterns of color-odor associations across cultures; we found that US and German participants had the most similar patterns of associations, followed by German and Malay participants. The largest group differences were between Malay and Netherlands-resident Chinese participants and between Dutch and Malaysian-Chinese participants. We conclude that culture plays a role in color-odor crossmodal associations, which likely arise, at least in part, through experience.

  10. Enhancement of retronasal odors by taste.

    Science.gov (United States)

    Green, Barry G; Nachtigal, Danielle; Hammond, Samuel; Lim, Juyun

    2012-01-01

    Psychophysical studies of interactions between retronasal olfaction and taste have focused most often on the enhancement of tastes by odors, which has been attributed primarily to a response bias (i.e., halo dumping). Based upon preliminary evidence that retronasal odors could also be enhanced by taste, the present study measured both forms of enhancement using appropriate response categories. In the first experiment, subjects rated taste ("sweet," "sour," "salty," and "bitter") and odor ("other") intensity for aqueous samples of 3 tastants (sucrose, NaCl, and citric acid) and 3 odorants (vanillin, citral, and furaneol), both alone and in taste-odor mixtures. The results showed that sucrose, but not the other taste stimuli, significantly increased the perceived intensity of all 3 odors. Enhancement of tastes by odors was inconsistent and generally weaker than enhancement of odors by sucrose. A second experiment used a flavored beverage and a custard dessert to test whether the findings from the first experiment would hold for the perception of actual foods. Adding sucrose significantly enhanced the intensity of "cherry" and "vanilla" flavors, whereas adding vanillin did not significantly enhance the intensity of sweetness. It is proposed that enhancement of retronasal odors by a sweet stimulus results from an adaptive sensory mechanism that serves to increase the salience of the flavor of nutritive foods. © The Author 2011. Published by Oxford University Press. All rights reserved.

  11. Body odor similarity in noncohabiting twins.

    Science.gov (United States)

    Roberts, S Craig; Gosling, L Morris; Spector, Tim D; Miller, Paul; Penn, Dustin J; Petrie, Marion

    2005-10-01

    There is currently considerable interest in biometric approaches using human odor as a marker of disease or genetic individuality. Body odor is also thought to be used during mate choice to select genetically compatible mates. The idea that body odor reveals information about both genetic identity and genetic similarity is most readily tested by examining odor in twin pairs. However, although this idea can be traced back 130 years to Francis Galton in 1875, most studies using dogs fail to control for shared environmental effects associated with cohabitation. Here we show that odors of identical twins (but not dizygotic twins) can be matched by human sniffers at rates better than chance, even when the twins are living apart. In addition, matching frequencies for identical twin odors were not significantly different from those for duplicate odors from the same individual. These results indicate an important genetic influence on body odor and the potential for developing technologies for human odor printing in relation to underlying genotype.

  12. Odors: appetizing or satiating? Development of appetite during odor exposure over time

    NARCIS (Netherlands)

    Ramaekers, M.G.; Boesveldt, S.; Lakemond, C.M.M.; Boekel, van M.A.J.S.; Luning, P.A.

    2014-01-01

    Background: Exposure to palatable food odors influences appetite responses, either promoting or inhibiting food intake. Possibly, food odors are appetizing after a short exposure (of circa 1–3¿min), but become satiating over time (circa 10–20¿min). Objective: To investigate the effect of odor

  13. Use of a Modified Vector Model for Odor Intensity Prediction of Odorant Mixtures

    Directory of Open Access Journals (Sweden)

    Luchun Yan

    2015-03-01

    Full Text Available Odor intensity (OI indicates the perceived intensity of an odor by the human nose, and it is usually rated by specialized assessors. In order to avoid restrictions on assessor participation in OI evaluations, the Vector Model which calculates the OI of a mixture as the vector sum of its unmixed components’ odor intensities was modified. Based on a detected linear relation between the OI and the logarithm of odor activity value (OAV—a ratio between chemical concentration and odor threshold of individual odorants, OI of the unmixed component was replaced with its corresponding logarithm of OAV. The interaction coefficient (cosα which represented the degree of interaction between two constituents was also measured in a simplified way. Through a series of odor intensity matching tests for binary, ternary and quaternary odor mixtures, the modified Vector Model provided an effective way of relating the OI of an odor mixture with the lnOAV values of its constituents. Thus, OI of an odor mixture could be directly predicted by employing the modified Vector Model after usual quantitative analysis. Besides, it was considered that the modified Vector Model was applicable for odor mixtures which consisted of odorants with the same chemical functional groups and similar molecular structures.

  14. Synthesis and stability of hydrogen selenide compounds at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Pace, Edward J.; Binns, Jack; Alvarez, Miriam Pena; Dalladay-Simpson, Philip; Gregoryanz, Eugene; Howie, Ross T. (Edinburgh); (CHPSTAR- China)

    2017-11-14

    The observation of high-temperature superconductivity in hydride sulfide (H2S) at high pressures has generated considerable interest in compressed hydrogen-rich compounds. High-pressure hydrogen selenide (H2Se) has also been predicted to be superconducting at high temperatures; however, its behaviour and stability upon compression remains unknown. In this study, we synthesize H2Se in situ from elemental Se and molecular H2 at pressures of 0.4 GPa and temperatures of 473 K. On compression at 300 K, we observe the high-pressure solid phase sequence (I-I'-IV) of H2Se through Raman spectroscopy and x-ray diffraction measurements, before dissociation into its constituent elements. Through the compression of H2Se in H2 media, we also observe the formation of a host-guest structure, (H2Se)2H2, which is stable at the same conditions as H2Se, with respect to decomposition. These measurements show that the behaviour of H2Se is remarkably similar to that of H2S and provides further understanding of the hydrogen chalcogenides under pressure.

  15. Sniff adjustment in an odor discrimination task in the rat: analytical or synthetic strategy?

    Directory of Open Access Journals (Sweden)

    Emmanuelle eCourtiol

    2014-05-01

    Full Text Available A growing body of evidence suggests that sniffing is not only the mode of delivery for odorant molecules but also contributes to olfactory perception. However, the precise role of sniffing variations remains unknown. The zonation hypothesis suggests that animals use sniffing variations to optimize the deposition of odorant molecules on the most receptive areas of the olfactory epithelium. Sniffing would thus depend on the physicochemical properties of odorants, particularly their sorption. Rojas-Líbano and Kay (2012 tested this hypothesis and showed that rats used different sniff strategies when they had to target a high-sorption molecule or a low-sorption molecule in a binary mixture. Which sniffing strategy is used by rats when they are confronted to discrimination between two similarly sorbent odorants remains unanswered. Particularly, is sniffing adjusted independently for each odorant according to its sorption properties (analytical processing, or is sniffing adjusted based on the pairing context (synthetic processing? We tested these hypotheses on rats performing a two-alternative choice discrimination of odorants with similar sorption properties. We recorded sniffing in a non-invasive manner using whole-body plethysmography during the behavioral task. We found that sniffing variations were not only a matter of odorant sorption properties and that the same odorant was sniffed differently depending on the odor pair in which it was presented. These results suggest that rather than being adjusted analytically, sniffing is instead adjusted synthetically and depends on the pair of odorants presented during the discrimination task. Our results show that sniffing is a specific sensorimotor act that depends on complex synthetic processes.

  16. Facial EMG responses to odors in solitude and with an audience.

    Science.gov (United States)

    Jäncke, L; Kaufmann, N

    1994-04-01

    Two experiments were undertaken to examine whether facial responses to odors correlate with the hedonic odor evaluation. Experiment 1 examined whether subjects (n = 20) spontaneously generated facial movements associated with odor evaluation when they are tested in private. To measure facial responses, EMG was recorded over six muscle regions (M. corrugator supercilii, M. procerus, M. nasalis, M. levator, M. orbicularis oculi and M. zygomaticus major) using surface electrodes. In experiment 2 the experimental group (n = 10) smelled the odors while they were visually inspected by the experimenter sitting in front of the test subjects. The control group (n = 10) performed the same experimental condition as those subjects participating in experiment 1. Facial EMG over four mimetic muscle regions (M. nasalis, M. levator, M. zygomaticus major, M. orbicularis oculi) was measured while subjects smelled different odors. The main findings of this study may be summarized as follows: (i) there was no correlation between valence rating and facial EMG responses; (ii) pleasant odors did not evoke smiles when subjects smelled the odors in private; (iii) in solitude, highly concentrated malodors evoked facial EMG reactions of those mimetic muscles which are mainly involved in generating a facial display of disgust; (iv) those subjects confronted with an audience showed stronger facial reactions over the periocular and cheek region (indicative of a smile) during the smelling of pleasant odors than those who smelled these odors in private; (v) those subjects confronted with an audience showed stronger facial reactions over the M. nasalis region (indicative of a display of disgust) during the smelling of malodors than those who smelled the malodors in private. These results were taken as evidence for a more social communicative function of facial displays and strongly mitigates the reflexive-hedonic interpretation of facial displays to odors as supposed by Steiner.

  17. High energy density Z-pinch plasmas using flow stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Shumlak, U., E-mail: shumlak@uw.edu; Golingo, R. P., E-mail: shumlak@uw.edu; Nelson, B. A., E-mail: shumlak@uw.edu; Bowers, C. A., E-mail: shumlak@uw.edu; Doty, S. A., E-mail: shumlak@uw.edu; Forbes, E. G., E-mail: shumlak@uw.edu; Hughes, M. C., E-mail: shumlak@uw.edu; Kim, B., E-mail: shumlak@uw.edu; Knecht, S. D., E-mail: shumlak@uw.edu; Lambert, K. K., E-mail: shumlak@uw.edu; Lowrie, W., E-mail: shumlak@uw.edu; Ross, M. P., E-mail: shumlak@uw.edu; Weed, J. R., E-mail: shumlak@uw.edu [Aerospace and Energetics Research Program, University of Washington, Seattle, Washington, 98195-2250 (United States)

    2014-12-15

    The ZaP Flow Z-Pinch research project[1] at the University of Washington investigates the effect of sheared flows on MHD instabilities. Axially flowing Z-pinch plasmas are produced that are 100 cm long with a 1 cm radius. The plasma remains quiescent for many radial Alfvén times and axial flow times. The quiescent periods are characterized by low magnetic mode activity measured at several locations along the plasma column and by stationary visible plasma emission. Plasma evolution is modeled with high-resolution simulation codes – Mach2, WARPX, NIMROD, and HiFi. Plasma flow profiles are experimentally measured with a multi-chord ion Doppler spectrometer. A sheared flow profile is observed to be coincident with the quiescent period, and is consistent with classical plasma viscosity. Equilibrium is determined by diagnostic measurements: interferometry for density; spectroscopy for ion temperature, plasma flow, and density[2]; Thomson scattering for electron temperature; Zeeman splitting for internal magnetic field measurements[3]; and fast framing photography for global structure. Wall stabilization has been investigated computationally and experimentally by removing 70% of the surrounding conducting wall to demonstrate no change in stability behavior.[4] Experimental evidence suggests that the plasma lifetime is only limited by plasma supply and current waveform. The flow Z-pinch concept provides an approach to achieve high energy density plasmas,[5] which are large, easy to diagnose, and persist for extended durations. A new experiment, ZaP-HD, has been built to investigate this approach by separating the flow Z-pinch formation from the radial compression using a triaxial-electrode configuration. This innovation allows more detailed investigations of the sheared flow stabilizing effect, and it allows compression to much higher densities than previously achieved on ZaP by reducing the linear density and increasing the pinch current. Experimental results and

  18. Structure and stability of hydrous minerals at high pressure

    Science.gov (United States)

    Duffy, T. S.; Fei, Y.; Meade, C.; Hemley, R. J.; Mao, H. K.

    1994-01-01

    The presence of even small amounts of hydrogen in the Earth's deep interior may have profound effects on mantle melting, rheology, and electrical conductivity. The recent discovery of a large class of high-pressure H-bearing silicates further underscores the potentially important role for hydrous minerals in the Earth's mantle. Hydrogen may also be a significant component of the Earth's core, as has been recently documented by studies of iron hydride at high pressure. In this study, we explore the role of H in crystal structures at high pressure through detailed Raman spectroscopic and x ray diffraction studies of hydrous minerals compressed in diamond anvil cells. Brucite, Mg(OH)2, has a simple structure and serves as an analogue for the more complex hydrous silicates. Over the past five years, this material has been studied at high pressure using shock-compression, powder x ray diffraction, infrared spectroscopy, Raman spectroscopy, and neutron diffraction. In addition, we have recently carried out single-crystal synchrotron x-ray diffraction on Mg(OH)2 and Raman spectroscopy on Mg(OD)2 at elevated pressure. From all these studies, an interesting picture of the crystal chemical behavior of this material at high pressure is beginning to emerge. Some of the primary conclusions are as follows: First, hydrogen bonding is enhanced by the application of pressure. Second, layered minerals which are elastically anisotropic at low pressure may not be so at high pressure. Furthermore, the brucite data place constraints on the effect of hydrogen on seismic velocities and density at very high pressure. Third, the stability of hydrous minerals may be enhanced at high P by subtle structural rearrangements that are difficult to detect using traditional probes and require detailed spectroscopic analyses. Finally, brucite appears to be unique in that it undergoes pressure-induced disordering that is confined solely to the H-containing layers of the structure.

  19. Characterization and control of odorous gases at a landfill site: a case study in Hangzhou, China.

    Science.gov (United States)

    Ying, Ding; Chuanyu, Cai; Bin, Hu; Yueen, Xu; Xuejuan, Zheng; Yingxu, Chen; Weixiang, Wu

    2012-02-01

    Municipal solid waste (MSW) landfills are one of the major sources of offensive odors potentially creating annoyance in adjacent communities. At the end of May 2007, an odor pollution incident occurred at the Tianziling landfill site, Hangzhou, China, where the residents lodged complaints about the intense odor from the landfill, which drew a significant attention from the government. In this study, ambient air monitoring was conducted at the Tianziling landfill site. The main odor composition of the gas samples collected on June 1st 2007 and the reduction of various odorous gases from the samples collected on June 1st 2009 due to the applied odor control techniques were determined using gas chromatography-mass spectrometry (GC-MS). In addition, variations of primary odorous gaseous (NH(3) and H(2)S) concentrations at different locations in the landfill site from July 2007 to June 2009 were also investigated by using classical spectrophotometric methods. Results showed that a total of 68 volatile compounds were identified among which H(2)S (56.58-579.84 μg/m(3)) and NH(3) (520-4460 μg/m(3)) were the notable odor components contributing to 4.47-10.92% and 83.91-93.94% of total concentrations, respectively. Similar spatial and temporal shifts of H(2)S and NH(3) concentrations were observed and were significantly affected by environmental factors including temperature, air pressure and wind direction. Odor pollution was worse when high temperature, high humidity, low air pressure, and southeast, northeast or east wind appeared. Moreover, the environmental sampling points of the dumping area and the leachate treatment plant were found to be the main odor sources at the Tianziling landfill site. The odor control technologies used in this project had a good mitigating effect on the primary odorous compounds. This study provides long-term valuable information concerning the characteristics and control of odors at landfill sites in a long run. Copyright © 2011 Elsevier

  20. Cross-Cultural Administration of an Odor Discrimination Test.

    Science.gov (United States)

    Sorokowska, Agnieszka; Sorokowski, Piotr; Hummel, Thomas

    2014-01-01

    Olfactory sensitivity can be evaluated by various tests, with "Sniffin' Sticks" test (SST) being one of the most popular. SST consists of tests for odor threshold, discrimination, and identification. It seems relatively straightforward to administer threshold tests in different groups and societies and it has been shown that odor identification tests requires special adaptation before they can be administered to various populations. However, few studies have investigated the application of an odor discrimination task in various regions/cultures. In the present study, we compared the discrimination scores of 169 Polish people with the scores of 99 Tsimane', Bolivian Amerindians. The Tsimane' participants scored very low in the discrimination task, despite their general high olfactory sensitivity. This result suggests that when a discrimination task is chosen as the form of olfactory testing, some additional variables need to be controlled. We suggest three sources of low scores of our participants-their cognitive profile, the cultural background, i.e., little knowledge of the odors used in the discrimination test and problems associated with testing environment.

  1. Perceptual blending in odor mixtures depends on the nature of odorants and human olfactory expertise.

    Science.gov (United States)

    Barkat, S; Le Berre, E; Coureaud, G; Sicard, G; Thomas-Danguin, T

    2012-02-01

    Our olfactory system is confronted with complex mixtures of odorants, often recognized as single entities due to odor blending (e.g., coffee). In contrast, we are also able to discriminate odors from complex mixtures (e.g., off-odors). Therefore, the olfactory system is able to engage either configural or elemental processes when confronted with mixtures. However, the rules that govern the involvement of these processes during odor perception remain poorly understood. In our first experiment, we examined whether simple odorant mixtures (binary/ternary) could elicit configural perception. Twenty untrained subjects were asked to evaluate the odor typicality of mixtures and their constituents. The results revealed a significant increase in odor typicality in some but not all mixtures as compared with the single components, which suggest that perceptual odor blending can occur only in specific mixtures (configural processing). In our second experiment, we tested the hypothesis that general olfactory expertise can improve elemental perception of mixtures. Thirty-two trained subjects evaluated the odor typicality of the stimuli presented during the first experiment, and their responses were compared with those obtained from the untrained panelists. The results support the idea that general training with odors increases the elemental perception of binary and ternary blending mixtures.

  2. Odor Experience Facilitates Sparse Representations of New Odors in a Large-Scale Olfactory Bulb Model

    Science.gov (United States)

    Zhou, Shanglin; Migliore, Michele; Yu, Yuguo

    2016-01-01

    Prior odor experience has a profound effect on the coding of new odor inputs by animals. The olfactory bulb, the first relay of the olfactory pathway, can substantially shape the representations of odor inputs. How prior odor experience affects the representation of new odor inputs in olfactory bulb and its underlying network mechanism are still unclear. Here we carried out a series of simulations based on a large-scale realistic mitral-granule network model and found that prior odor experience not only accelerated formation of the network, but it also significantly strengthened sparse responses in the mitral cell network while decreasing sparse responses in the granule cell network. This modulation of sparse representations may be due to the increase of inhibitory synaptic weights. Correlations among mitral cells within the network and correlations between mitral network responses to different odors decreased gradually when the number of prior training odors was increased, resulting in a greater decorrelation of the bulb representations of input odors. Based on these findings, we conclude that the degree of prior odor experience facilitates degrees of sparse representations of new odors by the mitral cell network through experience-enhanced inhibition mechanism. PMID:26903819

  3. Positive relationship between odor identification and affective responses of negatively valenced odors

    Science.gov (United States)

    Martinec Nováková, Lenka; Plotěná, Dagmar; Roberts, S. Craig; Havlíček, Jan

    2015-01-01

    Hedonic ratings of odors and olfactory preferences are influenced by a number of modulating factors, such as prior experience and knowledge about an odor’s identity. The present study addresses the relationship between knowledge about an odor’s identity due to prior experience, assessed by means of a test of cued odor identification, and odor pleasantness ratings in children who exhibit ongoing olfactory learning. Ninety-one children aged 8–11 years rated the pleasantness of odors in the Sniffin’ Sticks test and, subsequently, took the odor identification test. A positive association between odor identification and pleasantness was found for two unpleasant food odors (garlic and fish): higher pleasantness ratings were exhibited by those participants who correctly identified these odors compared to those who failed to correctly identify them. However, we did not find a similar effect for any of the more pleasant odors. The results of this study suggest that pleasantness ratings of some odors may be modulated by the knowledge of their identity due to prior experience and that this relationship might be more evident in unpleasant odors. PMID:26029143

  4. Water Treatment Technology - Taste, Odor & Color.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on taste, odor, and color provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: taste and odor determination, control of…

  5. Microbial survival and odor in laundry

    DEFF Research Database (Denmark)

    Jepsen, Signe Munk; Johansen, Charlotte; Stahnke, Louise Heller

    2001-01-01

    , was formed during prolonged drying in cotton. The study demonstrates that microbial odor formation is a dominating factor determining the odor impression of laundered cotton and polyester textiles dried under slow drying conditions. The initial soiling with aromatic components has an additional impact...

  6. 46 CFR 58.16-25 - Odorization.

    Science.gov (United States)

    2010-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-25 Odorization. (a) All liquefied petroleum gases shall be effectively odorized by an agent of such character as to indicate...

  7. Effects of q and high beta on tokamak stability

    International Nuclear Information System (INIS)

    Brickhouse, N.S.; Callen, J.D.; Dexter, R.N.

    1984-08-01

    In the Columbia University Torus II tokamak plasmas have been studied with volume averaged toroidal beta values as high as 15%. Experimental equilibria have been compared with a 2D free boundary MHD equilibrium code PSEC. The stability of these equilibria has been computed using PEST, the predictions of which are compatible with an observed instability in Torus II which may be characterized as a high toroidal mode number ballooning fluctuation. In the University of Wisconsin Tokapole II tokamak disruptive instability behavior is investigated, with plasma able to be confined on closed magnetic surfaces in the scrape-off region, as the cylindrical edge safety factor is varied from q approx. 3 to q approx. 0.5. It is observed that at q/sub a/ approx. 3 major disruption activity occurs without current terminations, at q/sub a/ less than or equal to 2 well-confined plasmas are obtained without major disruption, and at q/sub a/ approx. 0.5 only partial reconnection accompanies minor disruptions

  8. Asymptotic Stability of High-dimensional Zakharov-Kuznetsov Solitons

    Science.gov (United States)

    Côte, Raphaël; Muñoz, Claudio; Pilod, Didier; Simpson, Gideon

    2016-05-01

    We prove that solitons (or solitary waves) of the Zakharov-Kuznetsov (ZK) equation, a physically relevant high dimensional generalization of the Korteweg-de Vries (KdV) equation appearing in Plasma Physics, and having mixed KdV and nonlinear Schrödinger (NLS) dynamics, are strongly asymptotically stable in the energy space. We also prove that the sum of well-arranged solitons is stable in the same space. Orbital stability of ZK solitons is well-known since the work of de Bouard [Proc R Soc Edinburgh 126:89-112, 1996]. Our proofs follow the ideas of Martel [SIAM J Math Anal 157:759-781, 2006] and Martel and Merle [Math Ann 341:391-427, 2008], applied for generalized KdV equations in one dimension. In particular, we extend to the high dimensional case several monotonicity properties for suitable half-portions of mass and energy; we also prove a new Liouville type property that characterizes ZK solitons, and a key Virial identity for the linear and nonlinear part of the ZK dynamics, obtained independently of the mixed KdV-NLS dynamics. This last Virial identity relies on a simple sign condition which is numerically tested for the two and three dimensional cases with no additional spectral assumptions required. Possible extensions to higher dimensions and different nonlinearities could be obtained after a suitable local well-posedness theory in the energy space, and the verification of a corresponding sign condition.

  9. Study of odor recorder using Mass Spectrometry

    Science.gov (United States)

    Miura, Tomohiro; Nakamoto, Takamichi; Moriizumi, Toyosaka

    It is necessary to determine the recipe of a target odor with sufficient accuracy to realize an odor recorder for recording and reproducing it. We studied the recipe measurement method of a target odor using a mass spectrometry. It was confirmed that the linear superposition was valid when the binary mixture of the apple-flavor components such as isobutyric acid and ethyl valerate was measured. The superposition of a mass spectrum pattern may enable the recipe determination of a multi-component odor easily. In this research, we succeeded in the recipe determinations of orange flavor made up of 14 component odors when its typical recipe, the equalized, the citral-enhanced and the citronellol-enhanced ones were measured.

  10. High speed machining of aluminium gear box without temperature stabilization

    Directory of Open Access Journals (Sweden)

    Abilio P. SILVA

    2010-01-01

    Full Text Available At the present time both clutch and mechanism housings, which are the main components from automotive gear boxes, are made of special aluminium alloys. These alloys are extremely light when compared with steel, making them a perfect choice to mitigate the cars weight and machining costs. Nonetheless they possess a high thermal expansion coefficient, which can be considered a major disadvantage since it makes necessary to pay extraordinary attention to dimensional variations during the production cycle due to temperature deviations. High speed machining of precision components made of aluminium requests thus their temperature to become previously stable. This procedure is the only way to force dimensions to stay inside its tolerance intervals. The main purpose of the present work was to assess the possibility to avoid the use of special ovens to make the clutch housing temperature become stable prior to machining. The dimensional stabilization of 40 sample parts, pre-heated at three temperature levels, was accomplished through the use of this system. The achieved results were made possible by analysing the part’s temperature at the machine’s entrance, the machine’s interior temperature, 35 measured dimensions and their tolerance intervals as well as the average temperature deviations of each of the five considered batches. By analysing the obtained results in detail it was possible to determine which dimensions show high sensitiveness to temperature (high correlation between dimension’s variation and temperature. Among these dimensions we can point out the ones related with depth, since they display the highest deviations due to temperature. Being a work with practical application it was possible to confirm the benefit of using this methodology by achieving significant enhancements on production efficiency, energy savings and reduction on maintenance costs, through the application of small adjustments to the machining sequence and by

  11. Recovery of Odorants from an Olfactometer Measured by Proton-Transfer-Reaction Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Anders Feilberg

    2013-06-01

    Full Text Available The aim of the present study was to examine the recovery of odorants during the dilution in an olfactometer designed according to the European standard for dynamic olfactometry. Nine odorants in the ppmv-range were examined including hydrogen sulfide, methanethiol, dimethyl sulfide, acetic acid, propanoic acid, butanoic acid, trimethylamine, 3-methylphenol and n-butanol. Each odorant was diluted in six dilution steps in descending order from 4,096 to 128 times dilutions. The final recovery of dimethyl sulfide and n-butanol after a 60-second pulse was only slightly affected by the dilution, whereas the recoveries of the other odorants were significantly affected by the dilution. The final recoveries of carboxylic acids, trimethylamine and 3-methylphenol were affected by the pulse duration and the signals did not reach stable levels within the 60-second pulse, while sulfur compounds and n-butanol reach a stable signal within a few seconds. In conclusion, the dilution of odorants in an olfactometer has a high impact on the recovery of odorants and when olfactometry is used to estimate the odor concentration, the recoveries have to be taken into consideration for correct measurements.

  12. Study of odor inside cars; Kuruma no nioi ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, S.; Ito, H.; Sakakibara, K.; Kaitani, K.; Hamada, C. [Toyota Central Research and Development Labs., Inc., Aichi (Japan); Matsuo, M. [Toyota Motor Corp., Aichi (Japan)

    1998-05-01

    This paper describes odor in automotive cabin. Odor of new cars is rapidly disappeared during the use. This is greatly due to the adaptation of olfaction. The generation of odor is also decreased. It was found that aliphatic and aromatic hydrocarbons were rapidly disappeared. Decrements of oxygen containing and sulfur compounds were low. For amines, high boiling amines increased after three months. The odor component from crews was derived from the exhalation. Trimethylamine, methyl sulfide as well as iso-prene were detected. They could be derived from tobacco smoke, perfume and hair conditioner. Exhaust gas of diesel vehicle going ahead is one of unpleasant odors from the running atmosphere. A correlation coefficient 0.77 was obtained between the stimulation and aldehyde/ketone. A correlation equation was deduced using stimulation, discomfort degree and odor characteristics as object variables and using logarithms of trace analysis values as explanation variables. There are still a lot of unknown issues concerning combined odors. 9 refs., 9 figs., 1 tab.

  13. The human brain representation of odor identification.

    Science.gov (United States)

    Kjelvik, Grete; Evensmoen, Hallvard R; Brezova, Veronika; Håberg, Asta K

    2012-07-01

    Odor identification (OI) tests are increasingly used clinically as biomarkers for Alzheimer's disease and schizophrenia. The aim of this study was to directly compare the neuronal correlates to identified odors vs. nonidentified odors. Seventeen females with normal olfactory function underwent a functional magnetic resonance imaging (fMRI) experiment with postscanning assessment of spontaneous uncued OI. An event-related analysis was performed to compare within-subject activity to spontaneously identified vs. nonidentified odors at the whole brain level, and in anatomic and functional regions of interest (ROIs) in the medial temporal lobe (MTL). Parameter estimate values and blood oxygenated level-dependent (BOLD) signal curves for correctly identified and nonidentified odors were derived from functional ROIs in hippocampus, entorhinal, piriform, and orbitofrontal cortices. Number of activated voxels and max parameter estimate values were obtained from anatomic ROIs in the hippocampus and the entorhinal cortex. At the whole brain level the correct OI gave rise to increased activity in the left entorhinal cortex and secondary olfactory structures, including the orbitofrontal cortex. Increased activation was also observed in fusiform, primary visual, and auditory cortices, inferior frontal plus inferior temporal gyri. The anatomic MTL ROI analysis showed increased activation in the left entorhinal cortex, right hippocampus, and posterior parahippocampal gyri in correct OI. In the entorhinal cortex and hippocampus the BOLD signal increased specifically in response to identified odors and decreased for nonidentified odors. In orbitofrontal and piriform cortices both identified and nonidentified odors gave rise to an increased BOLD signal, but the response to identified odors was significantly greater than that for nonidentified odors. These results support a specific role for entorhinal cortex and hippocampus in OI, whereas piriform and orbitofrontal cortices are

  14. Stability of monoclonal antibodies at high-concentration

    DEFF Research Database (Denmark)

    Neergaard, Martin S; Nielsen, Anders D; Parshad, Henrik

    2014-01-01

    . The stability of our mAb molecules is clearly affected by the IgG framework, and this study suggests that subclass switching may alter aggregation propensity and aggregation pathway and thus potentially improve the overall formulation stability while retaining antigen specificity.......Few studies have so far directly compared the impact of antibody subclass on protein stability. This case study investigates two mAbs (one IgG1 and one IgG4 ) with identical variable region. Investigations of mAbs that recognize similar epitopes are necessary to identify possible differences...... between the IgG subclasses. Both physical and chemical stability were evaluated by applying a range of methods to measure formation of protein aggregates [size-exclusion chromatography (SEC)-HPLC and UV340 nm], structural integrity (circular dichroism and FTIR), thermodynamic stability (differential...

  15. Nonlinear stability and control study of highly maneuverable high performance aircraft, phase 2

    Science.gov (United States)

    Mohler, R. R.

    1992-01-01

    This research should lead to the development of new nonlinear methodologies for the adaptive control and stability analysis of high angle-of-attack aircraft such as the F18 (HARV). The emphasis has been on nonlinear adaptive control, but associated model development, system identification, stability analysis and simulation is performed in some detail as well. Various models under investigation for different purposes are summarized in tabular form. Models and simulation for the longitudinal dynamics have been developed for all types except the nonlinear ordinary differential equation model. Briefly, studies completed indicate that nonlinear adaptive control can outperform linear adaptive control for rapid maneuvers with large changes in alpha. The transient responses are compared where the desired alpha varies from 5 degrees to 60 degrees to 30 degrees and back to 5 degrees in all about 16 sec. Here, the horizontal stabilator is the only control used with an assumed first-order linear actuator with a 1/30 sec time constant.

  16. Organic transistors with high thermal stability for medical applications.

    Science.gov (United States)

    Kuribara, Kazunori; Wang, He; Uchiyama, Naoya; Fukuda, Kenjiro; Yokota, Tomoyuki; Zschieschang, Ute; Jaye, Cherno; Fischer, Daniel; Klauk, Hagen; Yamamoto, Tatsuya; Takimiya, Kazuo; Ikeda, Masaaki; Kuwabara, Hirokazu; Sekitani, Tsuyoshi; Loo, Yueh-Lin; Someya, Takao

    2012-03-06

    The excellent mechanical flexibility of organic electronic devices is expected to open up a range of new application opportunities in electronics, such as flexible displays, robotic sensors, and biological and medical electronic applications. However, one of the major remaining issues for organic devices is their instability, especially their thermal instability, because low melting temperatures and large thermal expansion coefficients of organic materials cause thermal degradation. Here we demonstrate the fabrication of flexible thin-film transistors with excellent thermal stability and their viability for biomedical sterilization processes. The organic thin-film transistors comprise a high-mobility organic semiconductor, dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene, and thin gate dielectrics comprising a 2-nm-thick self-assembled monolayer and a 4-nm-thick aluminium oxide layer. The transistors exhibit a mobility of 1.2 cm(2) V(-1)s(-1) within a 2 V operation and are stable even after exposure to conditions typically used for medical sterilization.

  17. Comparison of Breastmilk Odor and Vanilla Odor on Mitigating Premature Infants' Response to Pain During and After Venipuncture.

    Science.gov (United States)

    Jebreili, Mahnaz; Neshat, Hanieh; Seyyedrasouli, Aleheh; Ghojazade, Morteza; Hosseini, Mohammad Bagher; Hamishehkar, Hamed

    2015-09-01

    The main purpose of this study was to investigate the calming effects of breastmilk odor and vanilla odor on preterm infants during and after venipuncture. One hundred thirty-five preterm infants were randomly selected and divided into three groups: control, vanilla odor, and breastmilk odor. Infants in the breastmilk group were exposed to breastmilk odor, and infants in the vanilla group were exposed to vanilla odor from 5 minutes before the start of sampling until 30 seconds after sampling. The Premature Infant Pain Profile was used for calculating quality of pain in infants during and after sampling. Statistical analyses showed that both vanilla and breastmilk odors had calming effects on premature infants during sampling, but just breastmilk odor had calming effects on infants after the end of sampling. Compared with vanilla odor, breastmilk odor has more calming effects on premature infants. Breastmilk odor can be used for calming premature infants during and after venipuncture.

  18. Highly Organic Soil Stabilization by Using Sugarcane Bagasse Ash (SCBA

    Directory of Open Access Journals (Sweden)

    Abu Talib Mohd Khaidir

    2017-01-01

    Full Text Available The study objective is to develop alternative binders that are environment friendly by utilizing sugarcane bagasse ash (SCBA in the organic soil stabilization. Together with SCBA, Ordinary Portland Cement (OPC, calcium chloride (CaCl2 and silica sand (K7 were used as additives to stabilize the peat. In obtaining the optimal mix design, specimens of stabilized peat were tested in unconfined compression. It was found that stabilized peat comprising 20% and 5% (PCB1-20 and PCB2-5 partial replacement of OPC with SCBA 1 and SCBA 2 attain the maximum unconfined compressive strength (UCS and discovered greater than UCS of peat-cement (PC specimen. At the optimal mix design, the UCS of the stabilized peat specimens increased with increasing of curing time, preloading rate, OPC and K7 dosage. For PCB1-20 mixture, inclusion of a minimum OPC of 300kg/m3 and K7 of 500kg/m3 along with curing under 20kPa pressure is recommendable for the peat stabilization to be effective. However for PCB2-5, it suggested to use more OPC and K7 dosage or alternatively increase the preloading during curing to 40kPa in order to achieve target UCS. It can be concluded that SCBA 1 has better quality than SCBA 2 in peat stabilization especially the contribution made by its fine particle size.

  19. Combinations of two odorants of smell identification test for screening of olfactory impairment.

    Science.gov (United States)

    Shiga, Hideaki; Yamamoto, Junpei; Kitamura, Miwa; Nakagawa, Hideaki; Matsubasa, Tomoko; Seo, Atsuko; Miwa, Takaki

    2014-12-01

    To determine whether combinations of two odorants of the Open Essence smell identification test can be used to screen for olfactory impairment in Japanese people. A total of 243 Japanese subjects (142 males, 101 females; mean age, 37.5 years; age range, 20-62 years) were enrolled in the study. The main outcome measures were the results of olfactory testing by using the full 12 odorants (condensed milk, cooking gas, curry, cypress wood (Japanese cypress, hinoki), India ink, Japanese orange (mikan), menthol, perfume, roasted garlic, rose, sweaty-smelling clothes, and wood) of the Open Essence test as well as combinations of two odorants of the Open Essence test, and the results of self-reported questionnaires addressing awareness of a smell disorder, history of sinunasal disease, self-reported nasal obstruction, and history of smoking. In screening with combinations of two odorants, the highest positive likelihood ratio (19.1) was obtained with the cypress wood and India ink odorants. All subjects correctly identified the curry odorant. Combinations of other odorants also had high positive likelihood ratios (India ink and sweaty-smelling clothes, 17.6; perfume and sweaty-smelling clothes, 14.7; cypress wood and roasted garlic, 14.1; cypress wood and rose, 13.2; cypress wood and perfume, 11.0; cypress wood and wood, 10.7). The combination of cypress wood and India ink odorants may be useful for detecting individuals with olfactory impairment among subjects who can correctly identify the curry odorant. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Segregation of odor identity and intensity during odor discrimination in Drosophila mushroom body.

    Directory of Open Access Journals (Sweden)

    Shouzhen Xia

    2007-10-01

    Full Text Available Molecular and cellular studies have begun to unravel a neurobiological basis of olfactory processing, which appears conserved among vertebrate and invertebrate species. Studies have shown clearly that experience-dependent coding of odor identity occurs in "associative" olfactory centers (the piriform cortex in mammals and the mushroom body [MB] in insects. What remains unclear, however, is whether associative centers also mediate innate (spontaneous odor discrimination and how ongoing experience modifies odor discrimination. Here we show in naïve flies that Galphaq-mediated signaling in MB modulates spontaneous discrimination of odor identity but not odor intensity (concentration. In contrast, experience-dependent modification (conditioning of both odor identity and intensity occurs in MB exclusively via Galphas-mediated signaling. Our data suggest that spontaneous responses to odor identity and odor intensity discrimination are segregated at the MB level, and neural activity from MB further modulates olfactory processing by experience-independent Galphaq-dependent encoding of odor identity and by experience-induced Galphas-dependent encoding of odor intensity and identity.

  1. Segregation of odor identity and intensity during odor discrimination in Drosophila mushroom body.

    Science.gov (United States)

    Xia, Shouzhen; Tully, Tim

    2007-10-02

    Molecular and cellular studies have begun to unravel a neurobiological basis of olfactory processing, which appears conserved among vertebrate and invertebrate species. Studies have shown clearly that experience-dependent coding of odor identity occurs in "associative" olfactory centers (the piriform cortex in mammals and the mushroom body [MB] in insects). What remains unclear, however, is whether associative centers also mediate innate (spontaneous) odor discrimination and how ongoing experience modifies odor discrimination. Here we show in naïve flies that Galphaq-mediated signaling in MB modulates spontaneous discrimination of odor identity but not odor intensity (concentration). In contrast, experience-dependent modification (conditioning) of both odor identity and intensity occurs in MB exclusively via Galphas-mediated signaling. Our data suggest that spontaneous responses to odor identity and odor intensity discrimination are segregated at the MB level, and neural activity from MB further modulates olfactory processing by experience-independent Galphaq-dependent encoding of odor identity and by experience-induced Galphas-dependent encoding of odor intensity and identity.

  2. An odor interaction model of binary odorant mixtures by a partial differential equation method.

    Science.gov (United States)

    Yan, Luchun; Liu, Jiemin; Wang, Guihua; Wu, Chuandong

    2014-07-09

    A novel odor interaction model was proposed for binary mixtures of benzene and substituted benzenes by a partial differential equation (PDE) method. Based on the measurement method (tangent-intercept method) of partial molar volume, original parameters of corresponding formulas were reasonably displaced by perceptual measures. By these substitutions, it was possible to relate a mixture's odor intensity to the individual odorant's relative odor activity value (OAV). Several binary mixtures of benzene and substituted benzenes were respectively tested to establish the PDE models. The obtained results showed that the PDE model provided an easily interpretable method relating individual components to their joint odor intensity. Besides, both predictive performance and feasibility of the PDE model were proved well through a series of odor intensity matching tests. If combining the PDE model with portable gas detectors or on-line monitoring systems, olfactory evaluation of odor intensity will be achieved by instruments instead of odor assessors. Many disadvantages (e.g., expense on a fixed number of odor assessors) also will be successfully avoided. Thus, the PDE model is predicted to be helpful to the monitoring and management of odor pollutions.

  3. Stabilization

    Directory of Open Access Journals (Sweden)

    Muhammad H. Al-Malack

    2016-07-01

    Full Text Available Fuel oil flyash (FFA produced in power and water desalination plants firing crude oils in the Kingdom of Saudi Arabia is being disposed in landfills, which increases the burden on the environment, therefore, FFA utilization must be encouraged. In the current research, the effect of adding FFA on the engineering properties of two indigenous soils, namely sand and marl, was investigated. FFA was added at concentrations of 5%, 10% and 15% to both soils with and without the addition of Portland cement. Mixtures of the stabilized soils were thoroughly evaluated using compaction, California Bearing Ratio (CBR, unconfined compressive strength (USC and durability tests. Results of these tests indicated that stabilized sand mixtures could not attain the ACI strength requirements. However, marl was found to satisfy the ACI strength requirement when only 5% of FFA was added together with 5% of cement. When the FFA was increased to 10% and 15%, the mixture’s strength was found to decrease to values below the ACI requirements. Results of the Toxicity Characteristics Leaching Procedure (TCLP, which was performed on samples that passed the ACI requirements, indicated that FFA must be cautiously used in soil stabilization.

  4. High early failure rate of the Columbus posterior stabilized high-flexion knee prosthesis.

    Science.gov (United States)

    Jung, Woon-Hwa; Jeong, Jae-Heon; Ha, Yong-Chan; Lee, Young-Kyun; Koo, Kyung-Hoi

    2012-05-01

    Most studies report high survivorship rates for TKAs, however, we observed higher than anticipated rates of dislocation and femoral component loosening after implanting a Columbus posterior stabilized prosthesis. We therefore determined (1) the incidence of dislocation and aseptic loosening that occurred after implantation of posterior stabilized high-flexion prostheses in TKAs, (2) the causative factors of dislocation and aseptic femoral component loosening when comparing two designs of prostheses, and (3) the mechanisms of dislocation. We retrospectively reviewed 319 patients who underwent 384 TKAs from May 2007 to July 2008. These patients had been assigned alternately to receive a Scorpio posterior stabilized knee prosthesis (Group I, 158 patients, 187 knees) or a Columbus posterior stabilized knee prosthesis (Group II, 161 patients, 197 knees). We followed the patients with clinical and radiographic evaluations for a minimum of 24 months (mean, 26 months; range, 24-38 months). Ten retrieved prostheses were examined visually. Ten dislocations (5.1%; 10 of 197 knees) and seven aseptic loosenings of femoral components (3.6%; seven of 197 knees) occurred in Group II at a mean of 10.9 months postoperatively. However, no dislocation or loosening occurred in patients in Group I. Most dislocations were associated with varus flexion or flexion rotation movements during normal daily activities. The cam jump distance at 90º flexion for the Columbus prosthesis was lower than for the Scorpio prosthesis. We observed a high rate of early failure during short-term followup after implantation of a Columbus posterior stabilized prosthesis. It appears that early failures of the Columbus design were related to a different cam-post design attributable to a low jump distance during knee flexion. We no longer recommend using this device. Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

  5. Neural coding of binary mixtures in a structurally related odorant pair

    Science.gov (United States)

    Cruz, Georgina; Lowe, Graeme

    2013-01-01

    The encoding of odorant mixtures by olfactory sensory neurons depends on molecular interactions at peripheral receptors. However, the pharmacological basis of these interactions is not well defined. Both competitive and noncompetitive mechanisms of receptor binding and activation, or suppression, could contribute to coding. We studied this by analyzing responses of olfactory bulb glomeruli evoked by a pair of structurally related odorants, eugenol (EG) and methyl isoeugenol (MIEG). Fluorescence imaging in synaptopHluorin (spH) mice revealed that EG and MIEG evoked highly overlapped glomerular inputs, increasing the likelihood of mixture interactions. Glomerular responses to binary mixtures of EG and MIEG mostly showed hypoadditive interactions at intermediate and high odorant concentrations, with a few near threshold responses showing hyperadditivity. Dose-response profiles were well fitted by a model of two odorants competitively binding and activating a shared receptor linked to a non-linear transduction cascade. We saw no evidence of non-competitive mechanisms. PMID:23386975

  6. Effects of Odor on Emotion, with Implications

    Directory of Open Access Journals (Sweden)

    Mikiko eKadohisa

    2013-10-01

    Full Text Available The sense of smell is found widely in the animal kingdom. Human and animal studies show that odor perception is modulated by experience and/or physiological state (such as hunger, and that some odors can arouse emotion, and can lead to the recall of emotional memories. Further, odors can influence psychological and physiological states. Individual odorants are mapped via gene-specified receptors to corresponding glomeruli in the olfactory bulb, which directly projects to the piriform cortex and the amygdala without a thalamic relay. The odors to which a glomerulus responds reflect the chemical structure of the odorant. The piriform cortex and the amygdala both project to the orbitofrontal cortex which with the amygdala is involved in emotion and associative learning, and to the entorhinal/hippocampal system which is involved in long-term memory including episodic memory. Evidence that some odors can modulate emotion and cognition is described, and the possible implications for the treatment of psychological problems, for example in reducing the effects of stress, are considered.

  7. Positive implicit attitudes toward odor words.

    Science.gov (United States)

    Bulsing, Patricia J; Smeets, Monique A M; van den Hout, Marcel A

    2007-07-01

    Associations between certain odors and for instance health effects may lead to positive or negative attitudes toward these odors. However, in experiments we conducted using the Implicit Association Test (IAT), we encountered attitudes even to odor "words." The IAT is based on the principle that reaction times measuring the association between words from a target dimension (in this case, odor vs. a neutral reference category) and an attribute dimension (i.e., positive or negative words) reflect the attitude to the target, where attitude-congruent associations between target and attribute are reflected by shorter reaction times. In a first experiment, we found distinctly positive attitudes to the concept odor in a student sample, which was replicated in a second experiment. In the main experiment, subjects in the aromatherapy group, who prefer using scented consumer products for relaxation purposes, showed a significantly more positive attitude toward odor words in the IAT than a control group, who did not have such a preference. The fact that results from the implicit test were not always associated with explicitly stated attitudes toward the odor words attests to the fact that the IAT measures the attitude of interest in a different way. As such, the IAT has added value in circumstances where explicit tests can be biased.

  8. Stability Of Rubble Mound Breakwaters Using High Density Rock

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Beck, J. B.

    2000-01-01

    The present paper discusses the effect of mass density on stability of rubble mound breakwaters. A short literature review of existing knowledge is give to establish a background for the ongoing research. Furthermore, several model tests are described in which the stability of rubble mound...... breakwaters with armour stones of different densities are investigated. The results from the model test are discussed with respect to application and further research....

  9. Unpleasant odors increase aversion to monetary losses.

    Science.gov (United States)

    Stancak, Andrej; Xie, Yuxin; Fallon, Nicholas; Bulsing, Patricia; Giesbrecht, Timo; Thomas, Anna; Pantelous, Athanasios A

    2015-04-01

    Loss aversion is the tendency to prefer avoiding losses over acquiring gains of equal nominal values. Unpleasant odors not only influence affective state but have also been shown to activate brain regions similar to those mediating loss aversion. Therefore, we hypothesized a stronger loss aversion in a monetary gamble task if gambles were associated with an unpleasant as opposed to pleasant odor. In thirty human subjects, unpleasant (methylmercaptan), pleasant (jasmine), and neutral (clean air) odors were presented for 4 s. At the same time, uncertain gambles offering an equal chance of gain or loss of a variable amount of money, or a prospect of an assured win were displayed. One hundred different gambles were presented three times, each time paired with a different odor. Loss aversion, risk aversion, and logit sensitivity were evaluated using non-linear fitting of individual gamble decisions. Loss aversion was larger when prospects were displayed in the presence of methylmercaptan compared to jasmine or clean air. Moreover, individual differences in changes in loss aversion to the unpleasant as compared to pleasant odor correlated with odor pleasantness but not with odor intensity. Skin conductance responses to losses during the outcome period were larger when gambles were associated with methylmercaptan compared to jasmine. Increased loss aversion while perceiving an unpleasant odor suggests a dynamic adjustment of loss aversion toward greater sensitivity to losses. Given that odors are biological signals of hazards, such adjustment of loss aversion may have adaptive value in situations entailing threat or danger. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Enhancement of Retronasal Odors by Taste

    OpenAIRE

    Green, Barry G.; Nachtigal, Danielle; Hammond, Samuel; Lim, Juyun

    2011-01-01

    Psychophysical studies of interactions between retronasal olfaction and taste have focused most often on the enhancement of tastes by odors, which has been attributed primarily to a response bias (i.e., halo dumping). Based upon preliminary evidence that retronasal odors could also be enhanced by taste, the present study measured both forms of enhancement using appropriate response categories. In the first experiment, subjects rated taste (“sweet,” “sour,” “salty,” and “bitter”) and odor (“ot...

  11. Characterizing the Smell of Marijuana by Odor Impact of Volatile Compounds: An Application of Simultaneous Chemical and Sensory Analysis.

    Directory of Open Access Journals (Sweden)

    Somchai Rice

    Full Text Available Recent U.S. legislation permitting recreational use of marijuana in certain states brings the use of marijuana odor as probable cause for search and seizure to the forefront of forensic science, once again. This study showed the use of solid-phase microextraction with multidimensional gas chromatography--mass spectrometry and simultaneous human olfaction to characterize the total aroma of marijuana. The application of odor activity analysis offers an explanation as to why high volatile chemical concentration does not equate to most potent odor impact of a certain compound. This suggests that more attention should be focused on highly odorous compounds typically present in low concentrations, such as nonanal, decanol, o-cymene, benzaldehyde, which have more potent odor impact than previously reported marijuana headspace volatiles.

  12. Odor and odorous chemical emissions from animal buildings: part 1 - project overview, collection methods, and quality control

    Science.gov (United States)

    Livestock facilities have historically generated public concerns due to their emissions of odorous air and various chemical pollutants. Odor emission factors and identification of principal odorous chemicals are needed to better understand the problem. Applications of odor emission factors include i...

  13. The HSOB GAIA: a cryogenic high stability cesic optical bench for missions requiring sub-nanometric optical stability

    Science.gov (United States)

    Courteau, Pascal; Poupinet, Anne; Kroedel, Mathias; Sarri, Giuseppe

    2017-11-01

    Global astrometry, very demanding in term of stability, requires extremely stable material for optical bench. CeSiC developed by ECM and Alcatel Alenia Space for mirrors and high stability structures, offers the best compromise in term of structural strength, stability and very high lightweight capability, with characteristics leading to be insensitive to thermo-elastic at cryogenic T°. The HSOB GAIA study realised by Alcatel Alenia Space under ESA contract aimed to design, develop and test a full scale representative High Stability Optical Bench in CeSiC. The bench has been equipped with SAGEIS-CSO laser metrology system MOUSE1, Michelson interferometer composed of integrated optics with a nm resolution. The HSOB bench has been submitted to an homogeneous T° step under vacuum to characterise the homothetic behaviour of its two arms. The quite negligible inter-arms differential measured with a nm range reproducibility, demonstrates that a complete 3D structure in CeSiC has the same CTE homogeneity as characterisation samples, fully in line with the GAIA need (1pm at 120K). This participates to the demonstration that CeSiC properties at cryogenic T° is fully appropriate to the manufacturing of complex highly stable optical structures. This successful study confirms ECM and Alcatel Alenia Space ability to define and manufacture monolithic lightweight highly stable optical structures, based on inner cells triangular design made only possible by the unique CeSiC manufacturing process.

  14. Influence of the Chemical Structure on Odor Qualities and Odor Thresholds of Halogenated Guaiacol-Derived Odorants

    Directory of Open Access Journals (Sweden)

    Florian Juhlke

    2017-12-01

    Full Text Available Chlorinated guaiacol derivatives are found in waste water of pulp mills using chlorine in the bleaching process of wood pulp. They can also be detected in fish tissue, possibly causing off-odors. To date, there is no systematic investigation on the odor properties of halogenated guaiacol derivatives. To close this gap, odor thresholds in air and odor qualities of 14 compounds were determined by gas chromatography-olfactometry. Overall, the investigated compounds elicited smells that are characteristic for guaiacol, namely smoky, sweet, vanilla-like, but also medicinal and plaster-like. Their odor thresholds in air were, however, very low, ranging from 0.00072 to 23 ng/Lair. The lowest thresholds were found for 5-chloro- and 5-bromoguaiacol, followed by 4,5-dichloro- and 6-chloroguaiacol. Moreover, some inter-individual differences in odor threshold values could be observed, with the highest variations having been recorded for the individual values of 5-iodo- and 4-bromoguaiacol.

  15. How Far Does a Receptor Influence Vibrational Properties of an Odorant?

    DEFF Research Database (Denmark)

    Reese, Anna; List, Nanna Holmgaard; Kongsted, Jacob

    2016-01-01

    -assisted electron transfer reaction. We consider this controversy by studying the influence of a receptor on the vibrational properties of an odorant in atomistic details as the coupling between electronic degrees of freedom of the receptor and the vibrations of the odorant is the key parameter of the vibrationally......The biophysical mechanism of the sense of smell, or olfaction, is still highly debated. The mainstream explanation argues for a shape-based recognition of odorant molecules by olfactory receptors, while recent investigations suggest the primary olfactory event to be triggered by a vibrationally......-assisted electron transfer. Through molecular dynamics simulations we elucidate the binding specificity of a receptor towards acetophenone odorant. The vibrational properties of acetophenone inside the receptor are then studied by the polarizable embedding density functional theory approach, allowing to quantify...

  16. High stability lasers for lidar and remote sensing

    Science.gov (United States)

    Heine, Frank; Lange, Robert; Seel, Stefan; Smutny, Berry

    2017-11-01

    Tesat-Spacecom is currently building a set flight models of frequency stabilized lasers for the ESA Missions AEOLUS and LTP. Lasers with low intensity noise in the kHz region and analogue tuning capabilities for frequency and output power are developed for the on board metrology of the LTP project, the precursor mission for LISA. This type of laser is internally stabilized by precise temperature control, approaching an ALLAN variance of 10-9 for 100 sec. It can be easily locked to external frequency references with LIDAR) is used as the master frequency reference and is stabilized internally by a optical cavity. It shows a 3* 10-11 Allan variance from time intervals 1 sec - 1000 sec. Furthermore it is step-tunable for calibration of the receiver instrument with a speed of GHz / sec by a digital command interface. Performance and environmental test results will be presented.

  17. An Odor Interaction Model of Binary Odorant Mixtures by a Partial Differential Equation Method

    Directory of Open Access Journals (Sweden)

    Luchun Yan

    2014-07-01

    Full Text Available A novel odor interaction model was proposed for binary mixtures of benzene and substituted benzenes by a partial differential equation (PDE method. Based on the measurement method (tangent-intercept method of partial molar volume, original parameters of corresponding formulas were reasonably displaced by perceptual measures. By these substitutions, it was possible to relate a mixture’s odor intensity to the individual odorant’s relative odor activity value (OAV. Several binary mixtures of benzene and substituted benzenes were respectively tested to establish the PDE models. The obtained results showed that the PDE model provided an easily interpretable method relating individual components to their joint odor intensity. Besides, both predictive performance and feasibility of the PDE model were proved well through a series of odor intensity matching tests. If combining the PDE model with portable gas detectors or on-line monitoring systems, olfactory evaluation of odor intensity will be achieved by instruments instead of odor assessors. Many disadvantages (e.g., expense on a fixed number of odor assessors also will be successfully avoided. Thus, the PDE model is predicted to be helpful to the monitoring and management of odor pollutions.

  18. Odor Perception by Dogs: Evaluating Two Training Approaches for Odor Learning of Sniffer Dogs.

    Science.gov (United States)

    Fischer-Tenhagen, Carola; Johnen, Dorothea; Heuwieser, Wolfgang; Becker, Roland; Schallschmidt, Kristin; Nehls, Irene

    2017-06-01

    In this study, a standardized experimental set-up with various combinations of herbs as odor sources was designed. Two training approaches for sniffer dogs were compared; first, training with a pure reference odor, and second, training with a variety of odor mixtures with the target odor as a common denominator. The ability of the dogs to identify the target odor in a new context was tested. Six different herbs (basil, St. John's wort, dandelion, marjoram, parsley, ribwort) were chosen to produce reference materials in various mixtures with (positive) and without (negative) chamomile as the target odor source. The dogs were trained to show 1 of 2 different behaviors, 1 for the positive, and 1 for the negative sample as a yes/no task. Tests were double blind with one sample presented at a time. In both training approaches, dogs were able to detect chamomile as the target odor in any presented mixture with an average sensitivity of 72% and a specificity of 84%. Dogs trained with odor mixture containing the target odor had more correct indications in the transfer task. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. High-temperature stability of yttria-stabilized zirconia thermal barrier ...

    Indian Academy of Sciences (India)

    Abstract. Thermal barrier coatings (TBCs) of yttria-stabilized zirconia (YSZ) of different thicknesses with an intermediate bond coat were deposited on C-103 Nb alloy using the air plasma spraying technique. The coatings were subjected to rapid infra-red (IR) heating (∼25◦C s−1) up to ∼1250◦C and exposed up to 100 s at ...

  20. High beta and second stability region transport and stability analysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, M.H.; Phillips, M.W.

    1996-01-01

    This report describes MHD equilibrium and stability studies carried out at Northrop Grumman`s Advanced Technology and Development Center during the period March 1 to December 31, 1995. Significant progress is reported in both ideal and resistive MHD modeling of TFTR plasmas. Specifically, attention is concentrated on analysis of Advanced Tokamak experiments at TFTR involving plasmas in which the q-profiles were non-monotonic.

  1. Nonlinear stability and control study of highly maneuverable high performance aircraft

    Science.gov (United States)

    Mohler, R. R.

    1993-01-01

    This project is intended to research and develop new nonlinear methodologies for the control and stability analysis of high-performance, high angle-of-attack aircraft such as HARV (F18). Past research (reported in our Phase 1, 2, and 3 progress reports) is summarized and more details of final Phase 3 research is provided. While research emphasis is on nonlinear control, other tasks such as associated model development, system identification, stability analysis, and simulation are performed in some detail as well. An overview of various models that were investigated for different purposes such as an approximate model reference for control adaptation, as well as another model for accurate rigid-body longitudinal motion is provided. Only a very cursory analysis was made relative to type 8 (flexible body dynamics). Standard nonlinear longitudinal airframe dynamics (type 7) with the available modified F18 stability derivatives, thrust vectoring, actuator dynamics, and control constraints are utilized for simulated flight evaluation of derived controller performance in all cases studied.

  2. Significant step in ultra-high stability quartz crystal oscillators

    Czech Academy of Sciences Publication Activity Database

    Salzenstein, P.; Kuna, Alexander; Šojdr, Ludvík; Chauvin, J.

    2010-01-01

    Roč. 46, č. 21 (2010), s. 1433-1434 ISSN 0013-5194 Institutional research plan: CEZ:AV0Z20670512 Keywords : ultrahigh stability quartz crystal oscillators * flicker frequency modulation floor * frequency 5 MHz Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.001, year: 2010

  3. Computational Approaches for Decoding Select Odorant-Olfactory Receptor Interactions Using Mini-Virtual Screening.

    Science.gov (United States)

    Harini, K; Sowdhamini, Ramanathan

    2015-01-01

    Olfactory receptors (ORs) belong to the class A G-Protein Coupled Receptor superfamily of proteins. Unlike G-Protein Coupled Receptors, ORs exhibit a combinatorial response to odors/ligands. ORs display an affinity towards a range of odor molecules rather than binding to a specific set of ligands and conversely a single odorant molecule may bind to a number of olfactory receptors with varying affinities. The diversity in odor recognition is linked to the highly variable transmembrane domains of these receptors. The purpose of this study is to decode the odor-olfactory receptor interactions using in silico docking studies. In this study, a ligand (odor molecules) dataset of 125 molecules was used to carry out in silico docking using the GLIDE docking tool (SCHRODINGER Inc Pvt LTD). Previous studies, with smaller datasets of ligands, have shown that orthologous olfactory receptors respond to similarly-tuned ligands, but are dramatically different in their efficacy and potency. Ligand docking results were applied on homologous pairs (with varying sequence identity) of ORs from human and mouse genomes and ligand binding residues and the ligand profile differed among such related olfactory receptor sequences. This study revealed that homologous sequences with high sequence identity need not bind to the same/ similar ligand with a given affinity. A ligand profile has been obtained for each of the 20 receptors in this analysis which will be useful for expression and mutation studies on these receptors.

  4. Ontogeny of Odor-LiCl vs. Odor-Shock Learning: Similar Behaviors but Divergent Ages of Functional Amygdala Emergence

    Science.gov (United States)

    Raineki, Charlis; Shionoya, Kiseko; Sander, Kristin; Sullivan, Regina M.

    2009-01-01

    Both odor-preference and odor-aversion learning occur in perinatal pups before the maturation of brain structures that support this learning in adults. To characterize the development of odor learning, we compared three learning paradigms: (1) odor-LiCl (0.3M; 1% body weight, ip) and (2) odor-1.2-mA shock (hindlimb, 1sec)--both of which…

  5. Canine detection odor signatures for explosives

    Science.gov (United States)

    Williams, Marc; Johnston, J. M.; Cicoria, Matt; Paletz, E.; Waggoner, L. Paul; Edge, Cindy C.; Hallowell, Susan F.

    1998-12-01

    Dogs are capable of detecting and discriminating a number of compounds constituting a complex odor. However, they use only a few of these to recognize a substance. The focus of this research is to determine the compounds dogs learn to use in recognizing explosives. This is accomplished by training dogs under behavioral laboratory conditions to respond differentially on separate levers to 1) blank air, 2) a target odor, such as an explosive, and 3) all other odors (non-target odors). Vapor samples are generated by a serial dilution vapor generator whose operation and output is characterized by GC/MS. Once dogs learn this three-lever discrimination, testing sessions are conducted containing a number of probe trials in which vapor from constituent compounds of the target is presented. Which lever the dogs respond to on these probe trials indicates whether they can smell the compound at all (blank lever) or whether it smells like toe target odor (e.g., the explosive) or like something else. This method was conducted using TNT, C-4, and commercial dynamite. The data show the dogs' reactions to each of the constituent compounds tested for each explosive. Analysis of these data reveal the canine detection odor signature for these explosives.

  6. Exploration of hydrogen odorants for fuel cell vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, Daichi; Akai, Motoaki; Watanabe, Shogo [Japan Automobile Research Institute, 2530 Karima, Tsukuba, Ibaraki 305-0822 (Japan)

    2005-12-01

    The suitability of sulfur compounds (e.g., mercaptan and sulfide) and various sulfur-free smelling compounds for hydrogen odorants were evaluated. The influence of each smelling compound on fuel cell performance was evaluated through the measurement of I-V curves and voltage decline under constant current density, and their condensation properties under high-pressure condition were evaluated by measuring their vapor pressures. The results indicated that all the sulfur compounds evaluated in this study were not suitable as hydrogen odorants since their addition to the hydrogen caused serious degradation of fuel cell performance. Among the sulfur-free compounds, however, some oxygen-containing compounds (2,3-butanedione, ethyl isobutyrate and ethyl sugar lactone) and an unsaturated hydrocarbon (5-ethylidene-2-norbornene) proved to be promising candidates since their adverse effects on the fuel cell performance were minimal and their vapor pressures were adequate. (author)

  7. Exploration of hydrogen odorants for fuel cell vehicles

    Science.gov (United States)

    Imamura, Daichi; Akai, Motoaki; Watanabe, Shogo

    The suitability of sulfur compounds (e.g., mercaptan and sulfide) and various sulfur-free smelling compounds for hydrogen odorants were evaluated. The influence of each smelling compound on fuel cell performance was evaluated through the measurement of I- V curves and voltage decline under constant current density, and their condensation properties under high-pressure condition were evaluated by measuring their vapor pressures. The results indicated that all the sulfur compounds evaluated in this study were not suitable as hydrogen odorants since their addition to the hydrogen caused serious degradation of fuel cell performance. Among the sulfur-free compounds, however, some oxygen-containing compounds (2,3-butanedione, ethyl isobutyrate and ethyl sugar lactone) and an unsaturated hydrocarbon (5-ethylidene-2-norbornene) proved to be promising candidates since their adverse effects on the fuel cell performance were minimal and their vapor pressures were adequate.

  8. Stress and odor sensitivity in persons with noise sensitivity.

    Science.gov (United States)

    Nordin, Steven; Ljungberg, Jessica Korning; Claeson, Anna-Sara; Neely, Gregory

    2013-01-01

    Previous research has indicated that sensory sensitivity/intolerance to a specific modality may be part of a more general environmental hypersensitivity, and possibly mediated by stress. This study investigated the relationship between noise sensitivity, perceived stress, and odor sensitivity in a group of men. A quasi-experimental design was used. One-hundred and thirty-four male undergraduate students completed Weinstein's noise sensitivity scale from which a low-sensitivity group (n = 16) and a high-sensitivity (n = 16) group were formed. These two groups were screened for loss in auditory and olfactory detection sensitivity, and completed the perceived stress questionnaire (PSQ) and the chemical sensitivity scale (CSS). One-way analysis of variance and Spearman correlational analyses were performed. Significantly higher scores on the PSQ (P noise-sensitivity group compared to the low noise-sensitivity group. These findings raise the question of whether the relation between noise and odor sensitivity reflects a general environmental sensitivity.

  9. INVESTIGATION WITH MODAL ANALYSIS OF EFFECTS OF HIGH PV PENETRATION ON POWER SYSTEM VOLTAGE STABILITY

    OpenAIRE

    YILDIRIM, Burak

    2017-01-01

    This paper shows the effects of high PVintegration on the power system voltage stability. PV power plant was appliedto the IEEE 30 bus test system. Modal analysis method is used to show theeffect of PV integration on power system voltage stability. The power rate ofsynchronous generator in the IEEE 30 bus system is increased to show the powersystem stability effect of high PV penetration and then the PV generation withthe same power rate is connected appropriate bus in power system. The modal...

  10. TRPM5-expressing solitary chemosensory cells respond to odorous irritants.

    Science.gov (United States)

    Lin, Weihong; Ogura, Tatsuya; Margolskee, Robert F; Finger, Thomas E; Restrepo, Diego

    2008-03-01

    Inhaled airborne irritants elicit sensory responses in trigeminal nerves innervating the nasal epithelium, leading to protective reflexes. The sensory mechanisms involved in the detection of odorous irritants are poorly understood. We identified a large population of solitary chemosensory cells expressing the transient receptor potential channel M5 (TRPM5) using transgenic mice where the promoter of TRPM5 drives the expression of green fluorescent protein (GFP). Most of these solitary chemosensory cells lie in the anterior nasal cavity. These GFP-labeled solitary chemosensory cells exhibited immunoreactivity for synaptobrevin-2, a vesicle-associated membrane protein important for synaptic transmission. Concomitantly, we found trigeminal nerve fibers apposed closely to the solitary chemosensory cells, indicating potential transmission of sensory information to trigeminal fibers. In addition, stimulation of the nasal cavity with high concentrations (0.5-5 mM) of a variety of odorants elicited event-related potentials (ERPs) in areas rich in TRPM5-expressing solitary chemosensory cells. Furthermore, odorous chemicals and trigeminal stimuli induced changes in intracellular Ca(2+) levels in isolated TRPM5-expressing solitary chemosensory cells in a concentration-dependent manner. Together, our data show that the TRPM5-expressing cells respond to a variety of chemicals at high exposure levels typical of irritants and are positioned in the nasal cavity appropriately to monitor inhaled air quality.

  11. Surprisingly high stability of barley lipid transfer protein, LTP1, towards denaturant, heat and proteases

    DEFF Research Database (Denmark)

    Lindorff-Larsen, Kresten; Winther, J R

    2001-01-01

    have been suggested as transporters of monomers for cutin synthesis. We have analysed the stability of LTP1 towards denaturant, heat and proteases and found it to be a highly stable protein, which apparently does not denature at temperatures up to 100 degrees C. This high stability may be important...

  12. Narcolepsy and odor: preliminary report.

    Science.gov (United States)

    Dominguez-Ortega, L; Díaz-Gállego, E; Pozo, F; Cabrera García-Armenter, S; Serrano Comino, M; Dominguez-Sanchez, E

    2013-10-01

    This study has been carried out to test the clinical hypothesis of personal smell as a hint to the diagnosis of narcoleptic patients. Sweat samples from narcoleptic and healthy controls were tested independently by two trained dogs and their positive or negative detection compared to the gold standard diagnosis for narcolepsy. Neither trainer nor dog knew the source of the sample selected or its placement in the search device. Twelve narcoleptic patients, both sexes and various ages, recruited from April 2011 to June 2012 and diagnosed according to standard criteria, through their clinical records and nocturnal polysomnography plus multiple sleep latency test, made up the patient group. The control group was made up of 22 healthy volunteer without sleep disorders, both sexes and various ages. Sweat samples from both patients and controls were collected following the same protocol to avoid contamination, and tested independently by two trained dogs. Eleven narcoleptic were detected positive by the dogs while only three controls. It seems that narcoleptic patients have a distinct typical odor that trained dogs can detect. The development of olfactory test could be a useful method in the screening of narcolepsy while opens a new research area. Copyright © 2013 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  13. Utilization of Bagasse Fly Ash to Remove the Unpleasant Odor of Stevia Extract and Soy Milk

    Science.gov (United States)

    Ashadi; Masykuri, M.; Haryono

    2017-04-01

    Stevia is a safe natural sweetener that, but has a slightly unpleasant odor. Soy milk is undoubtedly high nutritional value, soy milk slightly unpleasant odor. Bagasse Fly Ash (BFA) is a sugar factory waste which is abundant, not widely used yet, and allowed to accumulate around the sugar factory. BFA can be activated with a solution of NaOH become adsorbent. Utilization of activated BFA to remove the odor of stevia extract and soy milk means the utilization of a waste to reduce other waste. Deodorizing done by batch system. Before being used as adsorbent, BFA characterized using SEM, XRD, FTIR, and AAS. Odor and color analysis conducted by organoleptic. The results shown activation increases the cavity, BFA containing SiO2 and Al2O3, does not contain Pb, Cr, Cd. The results shown that the BFA can reduce odor of stevia from a scale of 4 to 2, the color becomes more clear, unpleasant odor of soy milk is also reduced.

  14. Reshaping of bulbar odor response by nasal flow rate in the rat.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Courtiol

    2011-01-01

    Full Text Available The impact of respiratory dynamics on odor response has been poorly studied at the olfactory bulb level. However, it has been shown that sniffing in the behaving rodent is highly dynamic and varies both in frequency and flow rate. Bulbar odor response could vary with these sniffing parameter variations. Consequently, it is necessary to understand how nasal airflow can modify and shape odor response at the olfactory bulb level.To assess this question, we used a double cannulation and simulated nasal airflow protocol on anesthetized rats to uncouple nasal airflow from animal respiration. Both mitral/tufted cell extracellular unit activity and local field potentials (LFPs were recorded. We found that airflow changes in the normal range were sufficient to substantially reorganize the response of the olfactory bulb. In particular, cellular odor-evoked activities, LFP oscillations and spike phase-locking to LFPs were strongly modified by nasal flow rate.Our results indicate the importance of reconsidering the notion of odor coding as odor response at the bulbar level is ceaselessly modified by respiratory dynamics.

  15. The olfactory tubercle encodes odor valence in behaving mice.

    Science.gov (United States)

    Gadziola, Marie A; Tylicki, Kate A; Christian, Diana L; Wesson, Daniel W

    2015-03-18

    Sensory information acquires meaning to adaptively guide behaviors. Despite odors mediating a number of vital behaviors, the components of the olfactory system responsible for assigning meaning to odors remain unclear. The olfactory tubercle (OT), a ventral striatum structure that receives monosynaptic input from the olfactory bulb, is uniquely positioned to transform odor information into behaviorally relevant neural codes. No information is available, however, on the coding of odors among OT neurons in behaving animals. In recordings from mice engaged in an odor discrimination task, we report that the firing rate of OT neurons robustly and flexibly encodes the valence of conditioned odors over identity, with rewarded odors evoking greater firing rates. This coding of rewarded odors occurs before behavioral decisions and represents subsequent behavioral responses. We predict that the OT is an essential region whereby odor valence is encoded in the mammalian brain to guide goal-directed behaviors. Copyright © 2015 the authors 0270-6474/15/354515-13$15.00/0.

  16. Recovery of agricultural odors and odorous compounds from polyvinyl fluoride film bags

    Science.gov (United States)

    Accurate sampling methods are necessary when quantifying odor and volatile organic compound emissions at agricultural facilities. The commonly accepted methodology in the U.S. has been to collect odor samples in polyvinyl fluoride bags (PVF, brand name Tedlar®) and, subsequently, analyze with human ...

  17. Design of a high-resolution high-stability positioning mechanism for crystal optics

    International Nuclear Information System (INIS)

    Shu, D.; Toellner, T. S.; Alp, E. E.

    1999-01-01

    The authors present a novel miniature multi-axis driving structure that will allow positioning of two crystals with better than 50-nrad angular resolution and nanometer linear driving sensitivity.The precision and stability of this structure allow the user to align or adjust an assembly of crystals to achieve the same performance as does a single channel-cut crystal, so they call it an artificial channel-cut crystal. In this paper, the particular designs and specifications, as well as the test results,for a two-axis driving structure for a high-energy-resolution artificial channel-cut crystal monochromator are presented

  18. Stabilized high-power laser system for the gravitational wave detector advanced LIGO.

    Science.gov (United States)

    Kwee, P; Bogan, C; Danzmann, K; Frede, M; Kim, H; King, P; Pöld, J; Puncken, O; Savage, R L; Seifert, F; Wessels, P; Winkelmann, L; Willke, B

    2012-05-07

    An ultra-stable, high-power cw Nd:YAG laser system, developed for the ground-based gravitational wave detector Advanced LIGO (Laser Interferometer Gravitational-Wave Observatory), was comprehensively characterized. Laser power, frequency, beam pointing and beam quality were simultaneously stabilized using different active and passive schemes. The output beam, the performance of the stabilization, and the cross-coupling between different stabilization feedback control loops were characterized and found to fulfill most design requirements. The employed stabilization schemes and the achieved performance are of relevance to many high-precision optical experiments.

  19. Tracking fluid-borne odors in diverse and dynamic environments using multiple sensory mechanisms

    Science.gov (United States)

    Taylor, Brian Kyle

    The ability to locate odor sources in different types of environments (i.e. diverse) and environments that change radically during the mission (i.e., dynamic) is essential. While many engineered odor tracking systems have been developed, they appear to be designed for a particular environment (e.g., strong or low flow). In field conditions, agents may encounter both. Insect olfactory orientation studies show that several animals can locate odor sources in both high and low flow environments, and environments where the wind vanishes during tracking behavior. Furthermore, animals use multi-modal sensing, including olfaction, vision and touch to localize a source. This work uses simulated and hardware environments to explore how engineered systems can maintain wind-driven tracking behavior in diverse and dynamic environments. The simulation uses olfaction, vision and tactile attributes to track and localize a source in the following environments: high flow, low flow, and transition from high to low flow (i.e., Wind Stop). The hardware platform tests two disparate tracking strategies (including the simulated strategy) in an environment that transitions from strong to low flow. Results indicate that using a remembered wind direction post wind-shutoff is a viable way to maintain wind-driven tracking behavior in a wind stop environment, which can help bridge the gap between high flow and low flow strategies. Also, multi-modal sensing with tactile attributes, vision and olfaction helps a vehicle to localize a source. In addition to engineered systems, the moth Manduca sexta is challenged to track in the following environments: Wind and Odor, Wind Stop, Odor and No Wind, No Odor and No Wind to gain a better understanding of animal behavior in these environments. Results show that contrary to previous studies of different moth species, M. sexta does not generally maintain its wind-driven tracking behavior post-wind shutoff, but instead executes a stereotyped sequence of

  20. Calmodulin affects sensitization of Drosophila melanogaster odorant receptors

    Directory of Open Access Journals (Sweden)

    Latha eMukunda

    2016-02-01

    Full Text Available Flying insects have developed a remarkably sensitive olfactory system to detect faint and turbulent odor traces. This ability is linked to the olfactory receptors class of odorant receptors (ORs, occurring exclusively in winged insects. ORs form heteromeric complexes of an odorant specific receptor protein (OrX and a highly conserved co-receptor protein (Orco. The ORs form ligand gated ion channels that are tuned by intracellular signaling systems. Repetitive subthreshold odor stimulation of olfactory sensory neurons sensitizes insect ORs. This OR sensitization process requires Orco activity. In the present study we first asked whether OR sensitization can be monitored with heterologously expressed OR proteins. Using electrophysiological and calcium imaging methods we demonstrate that D. melanogaster OR proteins expressed in CHO cells show sensitization upon repeated weak stimulation. This was found for OR channels formed by Orco as well as by Or22a or Or56a and Orco. Moreover, we show that inhibition of calmodulin (CaM action on OR proteins, expressed in CHO cells, abolishes any sensitization. Finally, we investigated the sensitization phenomenon using an ex vivo preparation of olfactory sensory neurons (OSNs expressing Or22a inside the fly’s antenna. Using calcium imaging, we observed sensitization in the dendrites as well as in the soma. Inhibition of calmodulin with W7 disrupted the sensitization within the outer dendritic shaft, whereas the sensitization remained in the other OSN compartments. Taken together, our results suggest that CaM action is involved in sensitizing the OR complex and that this mechanisms accounts for the sensitization in the outer dendrites, whereas further mechanisms contribute to the sensitization observed in the other OSN compartments. The use of heterologously expressed OR proteins appears to be suitable for further investigations on the mechanistic basis of OR sensitization, while investigations on native

  1. Odor-taste learning assays in Drosophila larvae.

    Science.gov (United States)

    Gerber, Bertram; Biernacki, Roland; Thum, Jeannette

    2013-03-01

    The Drosophila larva is an emerging model for studies in behavioral neurogenetics because of its simplicity in terms of cell number. Despite this simplicity, basic features of neuronal organization and key behavior faculties are shared with adult flies and with mammals. Here, we describe a pavlovian-type learning assay in fruit fly larvae. A group of larvae is sequentially exposed to specific odors in the presence or the absence of sugar, and then tested to determine whether they prefer the odor previously experienced with the reward. The protocol uses a two-group, reciprocal training design: One group of Drosophila larvae is exposed to n-amyl acetate (AM) with a sugar reward (+), then subsequently exposed to 1-octanol (OCT) with no reward (denoted AM+/OCT). The other group receives the reciprocal training (AM/OCT+). The two groups of larvae are then tested for their choices between AM and OCT. Relatively higher preferences for AM after AM+/OCT training than after AM/OCT+ training reflect associative learning and are quantified by the learning index (LI). This method offers a robust, simple, cheap, and reasonably quick test for learning ability (an aversive version is available as well, using either high-concentration salt or quinine as punishment). With the concerted efforts of the Drosophila research community, we anticipate it will allow us to unravel the full circuitry underlying odor-taste learning on a single-cell level.

  2. A regulatory code for neuron-specific odor receptor expression.

    Directory of Open Access Journals (Sweden)

    Anandasankar Ray

    2008-05-01

    Full Text Available Olfactory receptor neurons (ORNs must select-from a large repertoire-which odor receptors to express. In Drosophila, most ORNs express one of 60 Or genes, and most Or genes are expressed in a single ORN class in a process that produces a stereotyped receptor-to-neuron map. The construction of this map poses a problem of receptor gene regulation that is remarkable in its dimension and about which little is known. By using a phylogenetic approach and the genome sequences of 12 Drosophila species, we systematically identified regulatory elements that are evolutionarily conserved and specific for individual Or genes of the maxillary palp. Genetic analysis of these elements supports a model in which each receptor gene contains a zip code, consisting of elements that act positively to promote expression in a subset of ORN classes, and elements that restrict expression to a single ORN class. We identified a transcription factor, Scalloped, that mediates repression. Some elements are used in other chemosensory organs, and some are conserved upstream of axon-guidance genes. Surprisingly, the odor response spectra and organization of maxillary palp ORNs have been extremely well-conserved for tens of millions of years, even though the amino acid sequences of the receptors are not highly conserved. These results, taken together, define the logic by which individual ORNs in the maxillary palp select which odor receptors to express.

  3. High pressure tokamaks. [Review of equilibrium and stability problems

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, G.

    1978-05-01

    The successful development of the neutral beam injection method of heating tokamaks has opened up a new range of theoretically predicted phenomena to be explored. This article, intended for the nonspecialist, reviews the existing experimental observations and theoretical understanding of tokamak equilibrium and large scale stability. Then a survey is presented of the new phenomena, such as flux conserving sequences of equilibria and pressure-driven ballooning modes, that are expected to accompany the significantly enhanced plasma pressure to be produced in tokamaks now under construction.

  4. Assessment of odor activity value coefficient and odor contribution based on binary interaction effects in waste disposal plant

    Science.gov (United States)

    Wu, Chuandong; Liu, Jiemin; Yan, Luchun; Chen, Haiying; Shao, Huiqi; Meng, Tian

    2015-02-01

    Odor activity value (OAV) has been widely used for the assessment of odor pollution from various sources. However, little attention has been paid to the extreme OAV variation and potential inaccuracies of odor contribution assessment caused by odor interaction effects. The objective of this study is to assess the odor interaction effect for precise assessment of odor contribution. In this paper, samples were collected from a food waste disposal plant, and analyzed by instrumental and olfactory method to conclude odorants' occurrence and OAV. Then odor activity value coefficient (γ) was first proposed to evaluate the type and the level of binary interaction effects based on determination of OAV variation. By multiplying OAV and γ, odor activity factor (OAF) was used to reflect the real OAV. Correlation between the sum of OAF and odor concentration reached 80.0 ± 5.7%, which was 10 times higher than the sum of OAV used before. Results showed that hydrogen sulfide contributed most (annual average 66.4 ± 15.8%) to odor pollution in the waste disposal plant. However, as odor intensity of samples in summer rising, odor contribution of trimethylamine increased to 48.3 ± 3.7% by the strong synergistic interaction effect, while odor contribution of phenol decreased to 0.1 ± 0.02% for the increasing antagonistic interaction effect.

  5. Preparation of [In-111]-labeled-DTPA-bombesin conjugates at high specific activity and stability: Evaluation of labeling parameters and potential stabilizers

    Energy Technology Data Exchange (ETDEWEB)

    Pujatti, P.B., E-mail: pujatti.pb@gmail.com [Directory of Radiopharmacy, Nuclear and Energy Research Institute (IPEN/CNEN), Av. Prof. Lineu Prestes, 2242 - Cidade Universitaria da USP - Butanta, Sao Paulo - SP - Brazil - CEP: 05508-000 (Brazil); Massicano, A.V.F.; Mengatti, J.; Araujo, E.B. de [Directory of Radiopharmacy, Nuclear and Energy Research Institute (IPEN/CNEN), Av. Prof. Lineu Prestes, 2242 - Cidade Universitaria da USP - Butanta, Sao Paulo - SP - Brazil - CEP: 05508-000 (Brazil)

    2012-05-15

    The aim of the present work was to obtain stabilized high specific activity (HSA) {sup 111}In-labeled bombesin conjugates for preclinical evaluations. Parameters influencing the kinetics of labeling were investigated and the effect of stabilizers on HSA radiopeptides stability at room temperature were systematically categorized applying chromatography techniques. A SA of 174 GBq/{mu}mol was achieved with high radiochemical purity, but the labeled compounds exhibited low stability. The addition of stabilizers avoided their radiolysis and significantly increased their stability. - Highlights: Black-Right-Pointing-Pointer We aimed to obtain stabilized high specific activity (SA) {sup 111}In-labeled bombesin conjugates. Black-Right-Pointing-Pointer The effect of stabilizers on high SA radiopeptides stability were investigated. Black-Right-Pointing-Pointer A maximum specific activity of 174 GBq/{mu}mol was achieved. Black-Right-Pointing-Pointer The studied stabilizers significantly increased the stability of high SA radiopeptides. Black-Right-Pointing-Pointer These stabilized bombesin conjugates will be applied in preclinical studies.

  6. High-temperature stability of yttria-stabilized zirconia thermal barrier ...

    Indian Academy of Sciences (India)

    or an internal combustion engine. For such kind of appli- cations, high heat flux is required for short time duration. Since, Nb alloys are being used for these applications, TBC with a prior bond coat is essential for better performance of components made by these alloys. Further, Nb alloys suffer from high temperature ...

  7. Identifying and tracking key odorants from cattle feedlots

    Science.gov (United States)

    Trabue, Steven; Scoggin, Kenwood; McConnell, Laura; Maghirang, Ronaldo; Razote, Edna; Hatfield, Jerry

    2011-08-01

    Odors from cattle feedlots can negatively affect air quality in local communities. Our objectives were the following: 1) identify key odor-causing compounds using odor activity values (OAVs) and gas chromatography-olfactometry (GC-O) techniques; 2) compare odor threshold values from published databases; and 3) track the movement of odors from a cattle feedlot to receptor community. Odorous compounds emitted from a cattle feedlot were sampled on-site, 250 m downwind and 3.2 km downwind using both sorbent tubes and denuders. Sorbent tubes were analyzed by both GC-MS and GC-MS-O and key odorants determined using both OAV and GC-Surface Nasal Impact Frequency (SNIF) analysis, while denuders were analyzed by ion chromatography. Odorant concentrations had a diurnal pattern with peak concentrations during early morning and late evening periods. Volatile fatty acids (VFAs) were the most abundant of the major odorants. Odorants with concentrations above their odor threshold values at the feedlot included amines, VFAs, phenol compounds, and indole compounds. Key odorants at the feedlot were VFAs and phenol compounds, but their relative importance diminished with downwind distance. Indole compounds, while not the key odorants at the feedlot, increased in relative importance downwind of the feedlot. In general, the odorous compounds identified by GC-SNIF and OAV as having fecal/manure nature were similar. GC-SNIF was the more sensitive analytical technique; it identified several compounds that may have contributed to the unpleasantness of the cattle feedlot odor, but its throughput was extremely low thereby limiting its usefulness. There is a need to improve field sampling devices and odor threshold databases to enhance understanding and confidence in evaluating odors.

  8. High stability space frame for a large fusion laser

    International Nuclear Information System (INIS)

    Hurley, C.A.; Myall, J.O.

    1975-01-01

    The Shiva laser system is a large neodymium glass laser target irradiation facility being constructed at LLL to perform laser fusion experiments. A frame is being constructed to support the large number of laser components that make up the Shiva system. Twenty laser chains composed of amplifiers, spatial filters, polarizers, rotators, and mirrors will be arranged in an optimum geometry so that each beam arrives at the target simultaneously and within alignment tolerances. This frame is capable of supporting approximately 600 individual component assemblies and maintaining a tolerance of +-4-μrad rotation between any two points over a period of 100 s. Consideration has been given to the positional stability and support of the components, the geometrical array of stacked beams with respect to the oscillator and target, the flow of utilities (e.g., power cables and cooling gas pipes), good accessibility for operation and maintenance, and adaptability for change and growth

  9. Comparison of Thermal Stability of Dry High-strength Concrete and Wet High-strength Concrete

    Directory of Open Access Journals (Sweden)

    Musorina Tatiana

    2018-01-01

    Full Text Available High-strength concrete is a modern material, which occupies it`s own niche on the construction material market. It is applicable in a large-scale high-rise construction, particularly an underground construction is a frequently used solution for a space saving. Usually underground structure is related to a wet usage environment. Though not all properties of the high-strength concrete are investigated to the full extent. Under adverse climatic conditions of the Russian Federation one of the most important properties for constructional materials is a thermal capacity. Therefore, the main purpose of the paper is to compare a thermal capacity of the high-strength concrete in humid conditions and a thermal capacity of the high-strength concrete in dry operational condition. During the study dependency between thermal capacity and design wall thickness and ambient humidity has to be proven with two experiments. As a result the theoretical relation between thermal capacity characteristic – thermal inertia and wall thickness and ambient humidity was confirmed by the experimental data. The thermal capacity of a building is in direct ratio to the construction thickness. It follows from the experiments and calculations that wet high-strength concrete has less thermal stability.

  10. Comparison of Thermal Stability of Dry High-strength Concrete and Wet High-strength Concrete

    Science.gov (United States)

    Musorina, Tatiana; Katcay, Aleksandr; Selezneva, Anna; Kamskov, Victor

    2018-03-01

    High-strength concrete is a modern material, which occupies it`s own niche on the construction material market. It is applicable in a large-scale high-rise construction, particularly an underground construction is a frequently used solution for a space saving. Usually underground structure is related to a wet usage environment. Though not all properties of the high-strength concrete are investigated to the full extent. Under adverse climatic conditions of the Russian Federation one of the most important properties for constructional materials is a thermal capacity. Therefore, the main purpose of the paper is to compare a thermal capacity of the high-strength concrete in humid conditions and a thermal capacity of the high-strength concrete in dry operational condition. During the study dependency between thermal capacity and design wall thickness and ambient humidity has to be proven with two experiments. As a result the theoretical relation between thermal capacity characteristic - thermal inertia and wall thickness and ambient humidity was confirmed by the experimental data. The thermal capacity of a building is in direct ratio to the construction thickness. It follows from the experiments and calculations that wet high-strength concrete has less thermal stability.

  11. ACADEMIC ACHIEVEMENT OF HIGH SCHOOL STUDENTS IN RELATION TO THEIR EMOTIONAL STABILITY

    Directory of Open Access Journals (Sweden)

    Sima Kalita

    2016-10-01

    Full Text Available In the present study an attempt was made to know the relationship between personality factor emotional stability and academic achievement of the high school students of South Kamrup district of Assam, India. Students were randomly selected from different high schools of the selected area. A sample of 400(both boys and girls students was selected and Cattell’s Jr. High School Personality Questionnaire (HSPQ was administered to them and record of academic achievement was collected from the school record. Subsequently the data were subjected to statistical analysis with the help of percentage analysis and x2. Results indicated a significant relationship between emotional stability and academic achievement of high school students of South kamrup district, Assam, India. The study also depicted that high level of emotional stability leads to high academic achievement and low emotional stability leads to low level of academic achievement.

  12. Hybrid AC-High Voltage DC Grid Stability and Controls

    Science.gov (United States)

    Yu, Jicheng

    The growth of energy demands in recent years has been increasing faster than the expansion of transmission facility construction. This tendency cooperating with the continuous investing on the renewable energy resources drives the research, development, and construction of HVDC projects to create a more reliable, affordable, and environmentally friendly power grid. Constructing the hybrid AC-HVDC grid is a significant move in the development of the HVDC techniques; the form of dc system is evolving from the point-to-point stand-alone dc links to the embedded HVDC system and the multi-terminal HVDC (MTDC) system. The MTDC is a solution for the renewable energy interconnections, and the MTDC grids can improve the power system reliability, flexibility in economic dispatches, and converter/cable utilizing efficiencies. The dissertation reviews the HVDC technologies, discusses the stability issues regarding the ac and HVDC connections, proposes a novel power oscillation control strategy to improve system stability, and develops a nonlinear voltage droop control strategy for the MTDC grid. To verify the effectiveness the proposed power oscillation control strategy, a long distance paralleled AC-HVDC transmission test system is employed. Based on the PSCAD/EMTDC platform simulation results, the proposed power oscillation control strategy can improve the system dynamic performance and attenuate the power oscillations effectively. To validate the nonlinear voltage droop control strategy, three droop controls schemes are designed according to the proposed nonlinear voltage droop control design procedures. These control schemes are tested in a hybrid AC-MTDC system. The hybrid AC-MTDC system, which is first proposed in this dissertation, consists of two ac grids, two wind farms and a five-terminal HVDC grid connecting them. Simulation studies are performed in the PSCAD/EMTDC platform. According to the simulation results, all the three design schemes have their unique salient

  13. A High Reliability Frequency Stabilized Semiconductor Laser Source, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Ultrastable, narrow linewidth, high reliability MOPA sources are needed for high performance LIDARs in NASA for, wind speed measurement, surface topography and earth...

  14. High-pressure structural stability of the ductile intermetallic ...

    Indian Academy of Sciences (India)

    Keywords. Intermetallics; X-ray diffraction; high pressure; synchrotron radiation. Abstract. High-pressure angle dispersive ... Author Affiliations. S Meenakshi1. High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. Dates. Manuscript received: 10 July 2013 ...

  15. Global kink and ballooning modes in high-beta systems and stability of toroidal drift modes

    International Nuclear Information System (INIS)

    Galvao, R.M.O.; Goedbloed, J.P.; Rem, J.; Sakanaka, P.H.; Schep, T.J.; Venema, M.

    1983-01-01

    A numerical code (HBT) has been developed which solves for the equilibrium, global stability and high-n stability of plasmas with arbitrary cross-section. Various plasmas are analysed for their stability to these modes in the high-beta limit. Screw-pinch equilibria are stable to high-n ballooning modes up to betas of 18%. The eigenmode equation for drift waves is analysed numerically. The toroidal branch is shown to be destabilized by the non-adiabatic response of trapped and circulating particles. (author)

  16. Toxicity bioassays for water from black-odor rivers in Wenzhou, China.

    Science.gov (United States)

    DeFu, He; RuiRui, Chen; EnHui, Zhu; Na, Chen; Bo, Yang; HuaHong, Shi; MinSheng, Huang

    2015-02-01

    Following urbanization, a large number of urban rivers were contaminated and turned to black-odor rivers. The traditional approach for detecting water quality is based on chemical or physical analysis. However, biological toxicity of black-odor water has been less addressed. As two typical black-odor rivers, Jiushanwai River (JS) and Shanxia River (SX) are tributaries of Wen-Rui Tang River in Wenzhou (south of China). The eco-safety of the urban rivers was evaluated by bioassay for water toxicity in this study. Ten and 5 sampling sites were respectively set along JS and SX. Water samples were collected monthly from October 2010 to October 2011. The general physical and chemical parameters of river water were monitored. In order to investigate the ecotoxicological effects of black-odor water, the following bioassays were used: (1) Fish acute toxicity test (Danio rerio, comprehensive toxicity), (2) luminescent bacteria bioassay (Qinghaiensis vibrio, toxicity to bacteria), and (3) tropical claw embryo assay (Xenopus tropicalis, embryo toxicity). Biotoxicity of black-odor rivers water was demonstrated by D. rerio, Q. vibrio, and X. tropicalis embryos. Toxicological effects of black-odor water were respectively shown by mortality of zebrafish, and by the relative inhibitory light rate of luminescent bacteria. However, luminescent bacteria were more sensitive to inspect biotoxicity than zebrafish. In X. tropicalis embryos test, toxicological effects of black-odor water were mostly shown by embryos' survival rate and teratogenic rate. Bioassay results showed that toxicity of SX water was higher than that of JS water, especially in summer. Statistical analysis of luminescent bacteria toxicity test showed that biotoxicity of SX and JS was high in summer, but low in winter and spring. The seasonal changes of water toxicity of the black-odor river were positively correlative with changes of water temperature (p water. Typical black-odor river water displays different

  17. The typical MSW odorants identification and the spatial odorants distribution in a large-scale transfer station.

    Science.gov (United States)

    Sun, Zhongtao; Cheng, Zhaowen; Wang, Luochun; Lou, Ziyang; Zhu, Nanwen; Zhou, Xuejun; Feng, Lili

    2017-03-01

    Odorants from municipal solid waste (MSW) were complex variable, and the screening of key offensive odorants was the prerequisite for odor control process. In this study, spatial odor emissions and environmental impacts were investigated based on a large-scale working waste transfer station (LSWTS) using waste container system, and a comprehensive odor characterization method was developed and applied in terms of the odor concentration (OC), theory odor concentration (TOC), total chemical concentration (TCC), and electric nose (EN). The detected odor concentration ranged from 14 to 28 (dimensionless), and MSW container showed the highest OC value of 28, EN of 78, and TCC of 35 (ppm) due to the accumulation of leachate and residual MSW. Ninety-two species odorants were identified, and H 2 S, NH 3 , benzene, styrene, ethyl acetate, and dichloromethane were the main contributors in the container, while benzene, m,p,x-xylene, butanone, acetone, isopropanol, and ethyl acetate were predominant in the compression surface (CS) and compression plant (CP). Side of roads (SR) and unload hall (UH) showed low odorous impact. Based on this odor list, 20 species of odor substances were screened for the priority control through the synthetic evaluation method, considering the odorants concentrations, toxicity, threshold values, detection frequency, saturated vapor pressure, and appeared frequency. Graphical abstract.

  18. Odor mixture alters neural resources during symbolic problem solving.

    Science.gov (United States)

    Lorig, Tyler S; Malin, Emily L; Horwitz, Julie E

    2005-05-01

    The smell of a cup of coffee is produced by many different odor chemicals combined in a mixture, yet the perception of that odor is of a single unified whole. Recent evidence has demonstrated that mixtures of odors share some of the same spatiotemporal features of speech sounds and may use similar brain resources in associating those features with the symbols they represent. This experiment investigated the hypothesis that an odor mixture would interfere with a math task that requires symbolic but not spatial processing. Results indicated the pattern of brain electrical activity was similar for the single odors and the mixture during spatial processing. During solution of the task requiring symbolic processing, the odor mixture produced a pattern of brain electrical activity different from the single odorants. These data suggest that the perception of odor mixtures may use some of the same resources associated with symbolic processing.

  19. High-temperature stability of yttria-stabilized zirconia thermal barrier ...

    Indian Academy of Sciences (India)

    The coatings before and after IR heating were investigated by scanning electron microscopy, X-ray diffraction, electron probe microanalysis, microhardness and residual stress measurements in order to understand the effect of thermal shock on the properties of the TBC. On account of these high-temperature properties, ...

  20. High-stability quartz-crystal microbalance for investigations in surface science

    International Nuclear Information System (INIS)

    Bouzidi, L.; Narine, S.S.; Stefanov, K.G.; Slavin, A.J.

    2003-01-01

    This article describes a high-stability quartz-crystal microbalance (QCM) and the methodology for measuring the change in mass during thin-film growth in deposition and sputter processes. Much lower noise and higher-frequency stability have been achieved than with conventional QCMs. A stability of ±0.1 Hz at 6 MHz has been obtained over 4 h, with a rms stability of 0.03 Hz. The adsorption of one atomic monolayer of oxygen produces a frequency shift of about 5 Hz, so this stability enables the QCM to be used to determine the stoichiometry of submonolayer oxide films, as well as for high-accuracy measurements of adsorbate sticking probability and ion-milling rate

  1. Odor-Active Compounds in the Special Flavor Hops Huell Melon and Polaris.

    Science.gov (United States)

    Neiens, Silva D; Steinhaus, Martin

    2018-02-14

    The volatiles isolated from samples of the special flavor hop varieties, Huell Melon and Polaris, and from the aroma hop variety, Hallertau Tradition, by solvent extraction and solvent-assisted flavor evaporation (SAFE) were subjected to a comparative aroma extract dilution analysis (cAEDA), which resulted in 46 odor-active compounds in the flavor dilution (FD) factor range of 16 to 2048. On the basis of high FD factors, myrcene, (3R)-linalool, and 2- and 3-methylbutanoic acid were confirmed as important variety-independent hop odorants. (1R,4S)-Calamenene was identified for the first time as an odor-active compound in hops. Clear differences in the FD factors and their subsequent objectification by stable isotope dilution quantitation suggested that high concentrations of the esters ethyl 2-methylbutanoate, ethyl 2-methylpropanoate, and propyl 2-methylbutanoate cause the characteristic fruity, cantaloupe-like odor note in Huell Melon hops, whereas the fruity and minty odor notes in Polaris are associated with high amounts of 3-methylbutyl acetate and 1,8-cineole.

  2. Effects of Negative Affectivity and Odor Valence on Chemosensory and Symptom Perception and Perceived Ability to Focus on a Cognitive Task.

    Science.gov (United States)

    Nordin, Steven; Aldrin, Lina; Claeson, Anna-Sara; Andersson, Linus

    2017-01-01

    The aim was to gain understanding for the impact of negative affectivity (NA) and odor valance on perceptual aspects during low-level odorous exposure. Fifty-five young adults who were either relatively low or high in NA (anxiety, depression, and somatization) were randomized for exposure to either limonene (pleasant odor) or pyridine (unpleasant odor). In an exposure chamber, they took part in baseline, blank and stable exposure sessions, during which they rated odor intensity, impact on ability to focus on an imagined cognitive task, and intensity of symptoms. The results showed higher ratings of negative impact on ability to focus during exposure to the unpleasant odor compared with the pleasant odor, and an association between NA and symptom intensity, with 18% of the variance in symptom intensity explained by somatization. The association between NA and symptom intensity was found to be driven by the factor sex. These results imply (a) that prior findings of odorous exposure that interfere negatively with work performance may be due to impact of an unpleasant odor on ability to focus on cognitive tasks and (b) that there are associations between NA, sex, and symptoms that may partly be referred to attentiveness to and interpretation of bodily sensations.

  3. Odor recognition memory is not idepentently impaired in Parkinson's disease

    NARCIS (Netherlands)

    Boesveldt, S.; Muinck Keizer, de R.J.O.; Wolters, E.C.H.; Berendse, H.W.

    2009-01-01

    The results of previous studies in small groups of Parkinson's disease (PD) patients are inconclusive with regard to the presence of an odor recognition memory impairment in PD. The aim of the present study was to investigate odor recognition memory in PD in a larger group of patients. Odor

  4. Molecular determinants of odorant receptor function in insects

    Indian Academy of Sciences (India)

    2014-07-20

    Jul 20, 2014 ... foundation for investigating functional domains within odorant receptors that can lead to a molecular understanding of odor detection. .... TRAINING SET 1. Sequences of D. melanogaster. Methyl Phenol (MP) responsive. Odor Receptors expressed in adult. (Or10a,46aA,49b,71a,85b) and their orthologs ...

  5. Space-Qualifiable High Reliability Frequency-Stabilized CW Laser Source Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the SBIR Phase II effort to develop and space-qualify a 1.06 micron high reliability frequency-stabilized CW laser source that fully satisfies the...

  6. Equilibrium and stability of high-β plasmas in W7-AS

    International Nuclear Information System (INIS)

    Geiger, J.; Weller, A.; Nuehrenberg, C.; Werner, A.; Zarnstorff, M.; Kolesnichenko, Ya.I.

    2003-01-01

    In this paper the optimization of equilibrium and stability of high-β plasmas by means of the reduction of the Pfirsch-Schlueter currents is described. Furthermore the Alfven modes driven by neutral-beam injection are considered. (HSI)

  7. Space-Qualifiable High Reliability Frequency-Stabilized CW Laser Source Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the development and space qualification of a high reliability frequency-stabilized CW laser source at 1064 nm wavelength region to satisfy the...

  8. The impact of odor-reward memory on chemotaxis in larval Drosophila.

    Science.gov (United States)

    Schleyer, Michael; Reid, Samuel F; Pamir, Evren; Saumweber, Timo; Paisios, Emmanouil; Davies, Alexander; Gerber, Bertram; Louis, Matthieu

    2015-05-01

    How do animals adaptively integrate innate with learned behavioral tendencies? We tackle this question using chemotaxis as a paradigm. Chemotaxis in the Drosophila larva largely results from a sequence of runs and oriented turns. Thus, the larvae minimally need to determine (i) how fast to run, (ii) when to initiate a turn, and (iii) where to direct a turn. We first report how odor-source intensities modulate these decisions to bring about higher levels of chemotactic performance for higher odor-source intensities during innate chemotaxis. We then examine whether the same modulations are responsible for alterations of chemotactic performance by learned odor "valence" (understood throughout as level of attractiveness). We find that run speed (i) is neither modulated by the innate nor by the learned valence of an odor. Turn rate (ii), however, is modulated by both: the higher the innate or learned valence of the odor, the less often larvae turn whenever heading toward the odor source, and the more often they turn when heading away. Likewise, turning direction (iii) is modulated concordantly by innate and learned valence: turning is biased more strongly toward the odor source when either innate or learned valence is high. Using numerical simulations, we show that a modulation of both turn rate and of turning direction is sufficient to account for the empirically found differences in preference scores across experimental conditions. Our results suggest that innate and learned valence organize adaptive olfactory search behavior by their summed effects on turn rate and turning direction, but not on run speed. This work should aid studies into the neural mechanisms by which memory impacts specific aspects of behavior. © 2015 Schleyer et al.; Published by Cold Spring Harbor Laboratory Press.

  9. Behavioral responses to mammalian blood odor and a blood odor component in four species of large carnivores.

    Directory of Open Access Journals (Sweden)

    Sara Nilsson

    Full Text Available Only little is known about whether single volatile compounds are as efficient in eliciting behavioral responses in animals as the whole complex mixture of a behaviorally relevant odor. Recent studies analysing the composition of volatiles in mammalian blood, an important prey-associated odor stimulus for predators, found the odorant trans-4,5-epoxy-(E-2-decenal to evoke a typical "metallic, blood-like" odor quality in humans. We therefore assessed the behavior of captive Asian wild dogs (Cuon alpinus, African wild dogs (Lycaon pictus, South American bush dogs (Speothos venaticus, and Siberian tigers (Panthera tigris altaica when presented with wooden logs that were impregnated either with mammalian blood or with the blood odor component trans-4,5-epoxy-(E-2-decenal, and compared it to their behavior towards a fruity odor (iso-pentyl acetate and a near-odorless solvent (diethyl phthalate as control. We found that all four species displayed significantly more interactions with the odorized wooden logs such as sniffing, licking, biting, pawing, and toying, when they were impregnated with the two prey-associated odors compared to the two non-prey-associated odors. Most importantly, no significant differences were found in the number of interactions with the wooden logs impregnated with mammalian blood and the blood odor component in any of the four species. Only one of the four species, the South American bush dogs, displayed a significant decrease in the number of interactions with the odorized logs across the five sessions performed per odor stimulus. Taken together, the results demonstrate that a single blood odor component can be as efficient in eliciting behavioral responses in large carnivores as the odor of real blood, suggesting that trans-4,5-epoxy-(E-2-decenal may be perceived by predators as a "character impact compound" of mammalian blood odor. Further, the results suggest that odorized wooden logs are a suitable manner of environmental

  10. Behavioral responses to mammalian blood odor and a blood odor component in four species of large carnivores.

    Science.gov (United States)

    Nilsson, Sara; Sjöberg, Johanna; Amundin, Mats; Hartmann, Constanze; Buettner, Andrea; Laska, Matthias

    2014-01-01

    Only little is known about whether single volatile compounds are as efficient in eliciting behavioral responses in animals as the whole complex mixture of a behaviorally relevant odor. Recent studies analysing the composition of volatiles in mammalian blood, an important prey-associated odor stimulus for predators, found the odorant trans-4,5-epoxy-(E)-2-decenal to evoke a typical "metallic, blood-like" odor quality in humans. We therefore assessed the behavior of captive Asian wild dogs (Cuon alpinus), African wild dogs (Lycaon pictus), South American bush dogs (Speothos venaticus), and Siberian tigers (Panthera tigris altaica) when presented with wooden logs that were impregnated either with mammalian blood or with the blood odor component trans-4,5-epoxy-(E)-2-decenal, and compared it to their behavior towards a fruity odor (iso-pentyl acetate) and a near-odorless solvent (diethyl phthalate) as control. We found that all four species displayed significantly more interactions with the odorized wooden logs such as sniffing, licking, biting, pawing, and toying, when they were impregnated with the two prey-associated odors compared to the two non-prey-associated odors. Most importantly, no significant differences were found in the number of interactions with the wooden logs impregnated with mammalian blood and the blood odor component in any of the four species. Only one of the four species, the South American bush dogs, displayed a significant decrease in the number of interactions with the odorized logs across the five sessions performed per odor stimulus. Taken together, the results demonstrate that a single blood odor component can be as efficient in eliciting behavioral responses in large carnivores as the odor of real blood, suggesting that trans-4,5-epoxy-(E)-2-decenal may be perceived by predators as a "character impact compound" of mammalian blood odor. Further, the results suggest that odorized wooden logs are a suitable manner of environmental enrichment

  11. 10-Hydroxycamptothecin (HCPT) nanosuspensions stabilized by mPEG1000-HCPT conjugate: high stabilizing efficiency and improved antitumor efficacy.

    Science.gov (United States)

    Yang, Linjie; Hong, Jingyi; Di, Jing; Guo, Yifei; Han, Meihua; Liu, Meifeng; Wang, Xiangtao

    2017-01-01

    In this study, polyethylene glycol (PEG)ylated 10-hydroxycamptothecin (mPEG 1000 -HCPT) was synthesized and used as a stabilizer to prepare 10-hydroxycamptothecin (HCPT) nanosuspensions for their in vitro and in vivo antitumor investigation. The resultant HCPT nanosuspensions (HCPT-NSps) had a very high drug payload of 94.90% (w/w) and a mean particle size of 92.90±0.20 nm with narrow size distribution (polydispersity index of 0.16±0.01). HCPT-NSps could be lyophilized without the need of the addition of any cryoprotectant and then be reconstituted into nanosuspensions of a similar size by direct resuspension in water. HCPT was in crystalline form in HCPT-NSps. Using mPEG 1000 -HCPT as stabilizer, insoluble camptothecin and 7-ethyl-10-hydroxycamptothecin could also be easily made into nanosuspensions with similar features such as high drug payload, small particle size, and cryoprotectant-free freeze drying. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay indicated that the HCPT-NSps had a significantly higher cytotoxicity than HCPT injections, with 3.77 times lower IC 50 value against HepG2 cells and 14.1 times lower IC 50 value against MCF-7 cells. An in vivo study in H22 tumor-bearing mice after intravenous injection of HCPT-NSps demonstrated that HCPT-NSps significantly improved the antitumor efficacy compared to the commercially available HCPT injections (86.38% vs 34.97%) at the same dose of 5 mg/kg. Even at 1/4 of the dose, HCPT-NSps could also achieve a similar antitumor efficacy to that of HCPT injections. mPEG 1000 -HCPT may be a highly efficient stabilizer able to provide camptothecin-based drugs, and probably other antitumor agents containing aromatic structure, with unique nanosuspensions or nanocrystals for improved in vivo therapeutic efficacy.

  12. Identification and quantification of nuisance odors at a trash transfer station.

    Science.gov (United States)

    Curren, Jane; Hallis, Samantha A; Snyder, Cherie Cher L; Suffet, Irwin Mel H

    2016-12-01

    The objective of this study was to evaluate the effectiveness of a modified Odor Profile Method (OPM) at a trash transfer station (TTS). An updated Landfill Odor Wheel was used to define odor character and distinguish among odor sources. The Flavor Profile Analysis (FPA) intensity scale was used to rank the relative intensity of the various odor characters defined by the odor wheel and to understand how each odor profile changed off site. Finally, the odor wheel was used to select the appropriate chemical analysis to identify the odorants causing the odors identified by the human panelists. The OPM was demonstrated as an effective tool for characterizing and distinguishing odor sources at a TTS. Municipal solid waste (MSW) odors were characterized as rancid, sulfur, and fragrant; rancid odors were dominant in the odor profile on-site, while sulfur odors dominated off-site. Targeted chemical analysis was used to identify odorants potentially responsible for odors at the site. Methyl mercaptan (rotten vegetable) and hydrogen sulfide (rotten egg) were identified as the odorants most likely to be responsible for the sulfur odors at the site. Acetaldehyde (sweet, fruity), acetic acid (vinegar), and butyric acid (rancid) were identified as the odorants mostly likely to be causing the rancid and sour odors. Terpenes/pine odors were observed near the greenwaste pile. Results confirm that the OPM, together with properly selected chemical analyses, can be a useful tool for identifying and quantifying the sources of odors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Odor management in petroleum refining units; Gerenciamento de odores em refinaria de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Gutierres, Ricardo; Evangelho, Mauro Rocha; Moreira, Andrea Cristina de Castro Araujo [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). P e D de Energia e Desenvolvimento Sustentavel (PDEDS)

    2004-07-01

    Odor emissions can cause serious annoyance in the neighbourhood of the emissions sources related to industrial processes and effluent and wastewater treatments. Jointly with the industrial control for reducing the odor, the emissions monitoring becomes convenient for identification and quantification of compounds responsible for the odors. To reach this objective, they are proposed analytical and olfactometric methodologies. The analytical procedures are based on the application of methods of sampling and analysis in gas chromatography-mass spectrometry, accepted for environmental agencies. The olfactometric methodology is based on the use of procedures that consider the subjective manner with that the odors are felt and evaluated by the people. This work describes as these methodologies can be applied in petroleum refining units. (author)

  14. Triaxial fluxgate gradiometer of high stability and linearity

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Brauer, Peter; Primdahl, Fritz

    2005-01-01

    A novel highly stable magnetic fluxgate vector gradiometer is presented in this paper. It is based on two triaxial fluxgate sensors with the Compact Spherical Coil (CSC) feedback to demonstrate the feasibility of such instrument (the full gradient instrument will consist of at least four triaxial...... sensors for measuring all the components of the gradient tensor). The sensors have been designed and constructed for the geopotential German satellite CHAMP, and are based on the instrument flying on the Danish satellite Orsted dedicated to measure the Earth's magnetic field with very high precision...

  15. Diffusion Concept in Phase Stability of High Temperature Composites

    National Research Council Canada - National Science Library

    Zhao, Ji-Cheng

    2003-01-01

    A high-efficiency "diffusion multiple" approach was employed to determine the phase diagrams of nine ternary systems Nb-Ti-Si, Nb-Cr- Si, Nb-Cr-Ti, Ti-Cr-Si, Nb-Si-Al, Nb-Cr-Al, Nb-Ti-Al, Ti-Si-Al, and Ti-Cr-Al...

  16. High efficiency regeneration and genetic stability analysis of somatic ...

    African Journals Online (AJOL)

    Administrator

    2011-09-07

    Sep 7, 2011 ... G. bicolor contains relatively high levels of vitamin C, crude protein and ... Effects of different combinations and concentrations of plant growth regulators on callus and adventitious shoot formation in G. bicolor. Growth regulator. (mg/l) ..... induction and plantlet formation from mature embryos of Aleppo pine.

  17. Recovery of Agricultural Odors and Odorous Compounds from Polyvinyl Fluoride Film Bags

    Science.gov (United States)

    Parker, David B.; Perschbacher-Buser, Zena L.; Cole, N. Andy; Koziel, Jacek A.

    2010-01-01

    Accurate sampling methods are necessary when quantifying odor and volatile organic compound emissions at agricultural facilities. The commonly accepted methodology in the U.S. has been to collect odor samples in polyvinyl fluoride bags (PVF, brand name Tedlar®) and, subsequently, analyze with human panelists using dynamic triangular forced-choice olfactometry. The purpose of this research was to simultaneously quantify and compare recoveries of odor and odorous compounds from both commercial and homemade PVF sampling bags. A standard gas mixture consisting of p-cresol (40 μg m−3) and seven volatile fatty acids: acetic (2,311 μg m−3), propionic (15,800 μg m−3), isobutyric (1,686 μg m−3), butyric (1,049 μg m−3), isovaleric (1,236 μg m−3), valeric (643 μg m−3), and hexanoic (2,158 μg m−3) was placed in the PVF bags at times of 1 h, 1 d, 2 d, 3 d, and 7 d prior to compound and odor concentration analyses. Compound concentrations were quantified using sorbent tubes and gas chromatography/mass spectrometry. Odor concentration, intensity, and hedonic tone were measured using a panel of trained human subjects. Compound recoveries ranged from 2 to 40% after 1 h and 0 to 14% after 7 d. Between 1 h and 7 d, odor concentrations increased by 45% in commercial bags, and decreased by 39% in homemade bags. Minimal changes were observed in intensity and hedonic tone over the same time period. These results suggest that PVF bags can bias individual compound concentrations and odor as measured by dynamic triangular forced-choice olfactometry. PMID:22163671

  18. Effect of odor preexposure on acquisition of an odor discrimination in dogs.

    Science.gov (United States)

    Hall, Nathaniel J; Smith, David W; Wynne, Clive D L

    2014-06-01

    In two experiments, we investigated the impact of odor preexposure treatments on the acquisition of an olfactory discrimination in dogs. In the first experiment, four groups of dogs were each given five days' odor-exposure treatment prior to discrimination training. Dogs in the exposure group were exposed to anise extract (S+) for 30 min daily. Dogs in the Pavlovian-relevant pairing group received six daily delayed-conditioning trials to the same S+. The Pavlovian-irrelevant pairing group received conditioning trials to almond extract (S'). Dogs in the control group received no pretreatment. All of the dogs were then trained to detect S+ from a background pine odor (an AX-vs.-X discrimination). The Pavlovian-relevant pairing group acquired the odor discrimination significantly faster than all of the other exposure and control groups, and the remaining groups acquired the discrimination at the same rate as the no-exposure control group. In a second experiment, we extended these results to a within-subjects design using an AX-versus-BX discrimination. Six dogs were simultaneously trained on two different odor discriminations, one discrimination in which the S+ was previously Pavlovian conditioned, and one discrimination in which the S+ was novel. All of the dogs learned the odor discrimination with the previously conditioned S+ faster than they learned the novel odor discrimination, replicating the results of Experiment 1, and demonstrating that familiarity in the form of Pavlovian conditioning enhances odor-discrimination training. The potential mechanisms of the facilitated transfer of a Pavlovian conditioned stimulus to discrimination training are discussed.

  19. [Primary trimethylaminuria: the fish odor syndrome

    NARCIS (Netherlands)

    Montoya Alvarez, T.; Guardiola, P.; Roldan, J.O.; Elviro, R.; Wevers, R.A.; Guijarro, G.

    2009-01-01

    Primary trimethylaminuria, or fish odor syndrome, is a congenital metabolic disorder characterized by a failure in the hepatic trimethylamine (TMA) oxidation route to trimethylamine N-oxide (TMANO). TMA is mostly derived from dietary precursors such as choline, carnitine and TMANO. The presence of

  20. Cross-cultural color-odor associations

    NARCIS (Netherlands)

    Levitan, C.A.; Ren, J.; Boesveldt, S.; Chan, J.; McKenzie, K.J.; Levin, J.A.; Leong, C.X.; Bosch, van den J.F.

    2014-01-01

    Colors and odors are associated; for instance, people typically match the smell of strawberries to the color pink or red. These associations are forms of crossmodal correspondences. Recently, there has been discussion about the extent to which these correspondences arise for structural reasons

  1. Identification of Glossina morsitans morsitans odorant binding ...

    African Journals Online (AJOL)

    Tsetse flies are vectors of trypanosome parasites, causative agents of Trypanosomiasis in humans and animals. Odorant Binding Proteins (OBPs) are critical in insect olfaction as they bind volatile odours from the environment and transport them to receptors within olfactory receptor neurons for processing providing critical ...

  2. High stability of few layer graphene nanoplatelets in various solvents

    KAUST Repository

    Xu, X

    2017-04-25

    Dispersion of few-layer graphene nanoplatelets (GNPs) in liquid media is a crucial step for various applications. Here, we highlight a simple, nondestructive method for preparing stable aqueous colloidal solutions with GNP powder quickly dispersed in 5 wt.% sodium–hypochlorite- (NaClO) and sodium-bromide- (NaBr) salted solvent by bath sonication. This method makes it possible to easily prepare a highly concentrated colloidal solution (1 mgcenterdotml−1) of GNPs that can easily be re-dispersed in water (treated GNPs). The aqueous suspension we prepared remained stable for longer than a few weeks. We made similar tests with various solvents and dispersibility appeared to decrease with decreasing polarity. High-concentration suspensions using our facile dispersion method could be of particular interest to the large community using graphene for a diversity of applications.

  3. Thermal stability of nano structured fly ash synthesized by high ...

    African Journals Online (AJOL)

    In this paper, an attempt has been made to modify the micro sized fly ash into nano structured fly ash using High Energy Ball Mill. The smooth, glassy and an inert surface of the fly ash can be altered to a rough and more reactive state by this technique. Ball milling was carried out for the total duration of 30 hours. The sample ...

  4. Proposal of Odor Nuisance Index as Urban Planning Tool.

    Science.gov (United States)

    Invernizzi, Marzio; Capelli, Laura; Sironi, Selena

    2017-02-01

    This article analyzes the state of the art of the methods and models used for the characterization of odor annoyance and it preliminary advances some proposals for the evaluation of the olfactory nuisance. The use of a sensorial technique, such as dynamic olfactometry, is proposed for the analysis of odor concentrations, odor emission rates, and odor dispersions. A simple model for the quantification of environmental odor nuisance, based on the use of FIDOL factors, that are, frequency, intensity, duration, hedonic tone, and location, is proposed. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Method for enhancing stability of high explosives, for purposes of transport or storage, and the stabilized high explosives

    International Nuclear Information System (INIS)

    Nutt, G.L.

    1991-01-01

    This papent describes a method for suppressing the tendency of a porous solid high explosive to ignite and detonate. It comprises: filling substantially all the press of the solid high explosive material with a predetermined pore radius of at least 10μm with a relatively inert, stable, pore filling material in liquid form, the pore filling being selected from gallium, rubidium-potassium eutectic, and Wood's metal; and solidifying the pore filling material in the pores of the explosive material

  6. Austenite stability in the high strength metastable stainless steels

    OpenAIRE

    S.J. Pawlak

    2007-01-01

    Purpose: The aim of the present paper was to study the peculiarities of the austenite to martensite phase transformation (A-M), which is an essential step in the production technology of the high strength metastable stainless steels.Design/methodology/approach: The desired control over A-M transformation have been achieved by proper design of the steel chemistry, cold working and heat treatment.Findings: For a range of steel compositions, it was shown that severe cold working leads to fully m...

  7. Autonomous Micro-Air-Vehicle Control Based on Visual Sensing for Odor Source Localization

    Directory of Open Access Journals (Sweden)

    Kenzo Kurotsuchi

    2017-07-01

    Full Text Available In this paper, we propose a novel control method for autonomous-odor-source localization using visual and odor sensing by micro air vehicles (MAVs. Our method is based on biomimetics, which enable highly autonomous localization. Our method does not need any instruction signals, including even global positioning system (GPS signals. An experimenter simply blows a whistle, and the MAV will then start to hover, to seek an odor source, and to keep hovering near the source. The GPS-signal-free control based on visual sense enables indoor/underground use. Moreover, the MAV is light-weight (85 grams and does not cause harm to others even if it accidentally falls. Experiments conducted in the real world were successful in enabling odor source localization using the MAV with a bio-inspired searching method. The distance error of the localization was 63 cm, more accurate than the target distance of 120 cm for individual identification. Our odor source localization is the first step to a proof of concept for a danger warning system. These localization experiments were the first step to a proof of concept for a danger warning system to enable a safer and more secure society.

  8. Sensitivity of physiological emotional measures to odors depends on the product and the pleasantness ranges used

    Directory of Open Access Journals (Sweden)

    Aline Marie Pichon

    2015-12-01

    Full Text Available Emotions are characterized by synchronized changes in several components of an organism. Among them, physiological variations provide energy support for the expression of approach/avoid action tendencies induced by relevant stimuli, while self-reported subjective pleasantness feelings integrate all other emotional components and are plastic.Consequently, emotional responses evoked by odors should be highly differentiated when they are linked to different functions of olfaction (e.g., avoiding environmental hazards. As this differentiation has been observed for contrasted odors (very pleasant or unpleasant, we questioned whether subjective and physiological emotional response indicators could still disentangle subtle affective variations when no clear functional distinction is made (mildly pleasant or unpleasant fragrances. Here, we compared the sensitivity of behavioral and physiological (respiration, skin conductance, facial electromyography (EMG, and heart rate indicators in differentiating odor-elicited emotions in two situations: when a wide range of odor families was presented (e.g., fruity, animal, covering different functional meanings; or in response to a restricted range of products in one particular family (fragrances. Results show clear differences in physiological indicators to odors that display a wide range of reported pleasantness, but these differences almost entirely vanish when fragrances are used even though their subjective pleasantness still differed. Taken together, these results provide valuable information concerning the ability of classic verbal and psychophysiological measures to investigate subtle differences in emotional reactions to a restricted range of similar olfactory stimuli.

  9. Earwigs ( Labidura riparia) mimic rotting-flesh odor to deceive vertebrate predators

    Science.gov (United States)

    Byers, John A.

    2015-08-01

    Many insects repel predators with caustic chemicals, while insects mimicking odors of wastes/dead insects to fool predators have not been documented. We found that the shore earwig, Labidura riparia (Dermaptera: Labiduridae) when bitten by anole lizards, Anolis carolinenesus, spits a rotting-flesh odor that deceives these insectivores into rejecting prey. Once a lizard attacked and rejected an earwig, the lizard did not attack another earwig during several weeks despite consuming other prey, indicating associative learning after one trial. The fetid odor was found in the head-prothorax containing salivary glands of both male and female earwigs and was comprised of ˜100 ng dimethyl disulfide and ˜600 ng dimethyl trisulfide. Nymphs had earwig's forceps. Sulfides released by the earwig are similar to odors of carrion/feces, which may be innately repulsive to some vertebrate predators. The mean initial discharge percentage (IDP) of sulfides from a cohort of earwigs was 62 %; however, IDPs of individuals were highly variable (3-99 %; mean 57 %). The discharge refill time (DRT) to refill 50 % of the earwig's allomone reservoir was estimated at 13 h. A positive relationship in sulfide amounts with body weight was found only in females in 2009, suggesting metabolic cost tradeoffs were revealed when sulfide content was half that in 2010. This is the first report of insects releasing sulfur-containing compounds that may mimic carrion-fecal odors as a deceptive defense against vertebrate predators.

  10. High-mode-number ballooning modes in a heliotron/torsatron system: 2, Stability

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, N.

    1996-05-01

    In heliotron/torsantron systems that have a large Shafranov shift, the local magnetic shear is found to have no stabilizing effect on high-mode-number ballooning modes at the outer side of the torus, even in the region where the global shear is stellarator-like in nature. The disappearance of this stabilization, in combination with the compression of the flux surfaces at the outer side of the torus, leads at relatively low values of the plasma pressure to significant modifications of the stabilizing effect due to magnetic field-line bending on high-mode-number ballooning modes-specifically, that the field-line bending stabilization can be remarkably suppressed or enhanced. In an equilibrium that is slightly Mercier-unstable or completely Mercier-stable due to peaked pressure profiles, such as those used in standaxd stability calculations or observed in experiments on the Compact Helical System, high-mode-number ballooning modes are destabilized due to these modified stability effects, with their eigenfunctions highly localized along the field line. Highly localized mode structures such as these cause the ballooning mode eigenvalues {omega} {sup 2} to have a strong field line dependence through the strong dependence of the local magnetic curvature, such that the level surfaces of {omega} {sup 2} ({psi}, {theta} {sub k}, {alpha}), (<0) become spheroids in ({theta} {sub k}, {alpha}) space, where {psi} labels flux surfaces and {theta} {sub k} is the radial wavenumber. Because the spheroidal level surfaces for unstable eigenvalues are surrounded by level surfaces for stable eigenvalues of high-mode-number toroidal Alfven eigenmodes, those high-mode-number ballooning modes never lead to low-mode-number modes. In configuration space, these high- mode-number modes are localized in a single toroidal pitch of the helical coils, and hence they may experience substantial stabilization due to finite Larmor radius effects.

  11. Synthesis of high-temperature viscosity stabilizer used in drilling fluid

    Science.gov (United States)

    Zhang, Yanna; Luo, Huaidong; Shi, Libao; Huang, Hongjun

    2018-02-01

    Abstract For a well performance drilling fluid, when it operates in deep wells under high temperature, the most important property required is the thermal stability. The drilling fluid properties under high temperature can be controlled by proper selection of viscosity stabilizer, which can capture oxygen to protect polymer agent in the drilling fluid. In this paper a viscosity stabilizer PB-854 is described, which was synthesized by 4-phenoxybutyl bromide, paraformaldehyde, and phloroglucinol using etherification method and condensation reaction. We studied the effect of catalyst dosage, temperature, time, and stirring rate on the synthetic yield. Under this condition: molar ratio of 2-tert-Butylphenol, paraformaldehyde and phloroglucinol of 2:1:2.5, reacting temperature of 100 °C, stirring rate of 100 r min‑1, and mass content of catalyst of 15 %, char yield of 5-bromine-3-tert-butyl salicylaldehyde reached 86 %. Under this condition: molar ratio of 5-bromine-3-tert-butyl salicylaldehyde and phloroglucinol of 4, reacting temperature of 60 °C, reacting time of 30 min, volume content of sulphuric acid of 80 %, char yield of the target product viscosity stabilizer PB-854 is 86%. Finally, in this paper, infrared spectroscopy is adopted to analyse the structure of the synthetic product PB-854.The improvement in the stability of drilling fluid was further shown after adding the viscosity stabilizer in the common polymer drilling fluid under high temperature conditions of 120 °C ∼ 180 °C. The results show significant change in terms of fluid stability in the presence of this new stabilizer as it provides better stability.

  12. Nurse odor perception in various Japanese hospital settings

    Directory of Open Access Journals (Sweden)

    Masami Horiguchi

    2015-12-01

    Full Text Available Because unpleasant hospital odors affect the nursing environment, we investigated nurses' perceptions of the odors of various hospital settings: hospital rooms, nurse stations, and human waste disposal rooms to discard the urine, stools and diapers. A questionnaire based on the Japanese Ministry of the Environment's guidelines on odor index regulation was used to assess nurses' perceptions of odor intensity, comfort, tolerability, and description in the aforementioned settings. Questionnaires were distributed to nursing department directors at three Japanese hospitals, who then disseminated the questionnaires to nursing staff. Of the 1,151 questionnaires distributed, 496 nurses participated. Human waste disposal rooms had greater odor intensity and were perceived as more uncomfortable than the other settings. Unpleasant odors in disposal rooms, hospital rooms, and nurse stations were rated as slightly intolerable in comparison. Hospital and disposal rooms were mainly described as having a “pungent odor such as of urine and stool.” In contrast, nurse stations were described as having other unpleasant odors, such as chemical, human-body-related, or sewage-like odors. Given that nurses spend much of their time in hospital rooms and nurse stations, odor management in these two settings would likely improve nurses' working conditions at hospitals. Improving odors at nurse stations is feasible. Such improvements could have indirect effects on nurse turnover and burnout.

  13. Does odor and taste identification change during hyperemesis gravidarum?

    Science.gov (United States)

    Yasar, Mehmet; Sagit, Mustafa; Zeki Uludag, Semih; Ozcan, Ibrahim

    2016-02-01

    To investigate a difference in odor and taste identification among pregnant women with hyperemesis gravidarum, those with healthy pregnancy and non-pregnant women. This prospective, controlled study included 33 pregnant women with hyperemesis gravidarum, 33 healthy pregnant and 26 non-pregnant women. For all participants, rhinological examinations were performed. Odor and taste identification were performed by holding Sniffin' Sticks test battery (Burghart, Wedel, Germany) in all participants. There was a statistically significant difference in results of odor identification tests among the groups (p=0.031). Rose odor was selected as the most pleasant odor by the hyperemesis gravidarum group, 32 (96.9%). Orange odor was selected as the most pleasant odor by the healthy pregnant women, 33 (100%) whereas the banana odor was selected as the most pleasant odor by the healthy non-pregnant women, 10 (38.4%). In taste identification tests, there was a significant difference in total taste scores among the groups (p=0.003). It is obvious that there is a need to evaluate odor thresholds and other parameters by detailed studies on odor perception in the context of hyperemesis gravidarum. Copyright© by the Medical Assotiation of Zenica-Doboj Canton.

  14. Does odor and taste identification change during hyperemesis gravidarum?

    Directory of Open Access Journals (Sweden)

    Mehmet Yasar

    2016-02-01

    Full Text Available Aim To investigate a difference in odor and taste identification among pregnant women with hyperemesis gravidarum, those with healthy pregnancy and non-pregnant women. Methods This prospective, controlled study included 33 pregnant women with hyperemesis gravidarum, 33 healthy pregnant and 26 non-pregnant women. For all participants, rhinological examinations were performed. Odor and taste identification were performed by holding Sniffin Sticks test battery (Burghart, Wedel, Germany in all participants. Results There was a statistically significant difference in results of odor identification tests among the groups (p=0.031. Rose odor was selected as the most pleasant odor by the hyperemesis gravidarum group, 32 (96.9%. Orange odor was selected as the most pleasant odor by the healthy pregnant women, 33 (100% whereas the banana odor was selected as the most pleasant odor by the healthy non-pregnant women, 10 (38.4%. In taste identification tests, there was a significant difference in total taste scores among the groups (p=0.003. Conclusion It is obvious that there is a need to evaluate odor thresholds and other parameters by detailed studies on odor perception in the context of hyperemesis gravidarum.

  15. The insular taste cortex contributes to odor quality coding

    Directory of Open Access Journals (Sweden)

    Maria G Veldhuizen

    2010-07-01

    Full Text Available Despite distinct peripheral and central pathways, stimulation of both the olfactory and the gustatory systems may give rise to the sensation of sweetness. Whether there is a common central mechanism producing sweet quality sensations or two discrete mechanisms associated independently with gustatory and olfactory stimuli is currently unknown. Here we used fMRI to determine whether odor sweetness is represented in the piriform olfactory cortex, which is thought to code odor quality, or in the insular taste cortex, which is thought to code taste quality. Fifteen participants sampled two concentrations of a pure sweet taste (sucrose, two sweet food odors (chocolate and strawberry, and two sweet floral odors (lilac and rose. Replicating prior work we found that olfactory stimulation activated the piriform, orbitofrontal and insular cortices. Of these regions, only the insula also responded to sweet taste. More importantly, the magnitude of the response to the food odors, but not to the non-food odors, in this region of insula was positively correlated with odor sweetness rating. These findings demonstrate that insular taste cortex contributes to odor quality coding by representing the taste-like aspects of food odors. Since the effect was specific to the food odors, and only food odors are experienced with taste, we suggest this common central mechanism develops as a function of experiencing flavors.

  16. Unforeseen high temperature and humidity stability of FeCl3 intercalated few layer graphene

    DEFF Research Database (Denmark)

    Wehenkel, Dominique Joseph; Bointon, Thomas Hardisty; Booth, Tim

    2015-01-01

    microscopy and Raman spectroscopy conclusively demonstrate the unforseen stability of this transparent conductor to a relative humidity up to 100% at room temperature for 25 days, to a temperature up to 150 degrees C in atmosphere and to a temperature as high as 620 degrees C in vacuum, that is more than......We present the first systematic study of the stability of the structure and electrical properties of FeCl3 intercalated few-layer graphene to high levels of humidity and high temperature. Complementary experimental techniques such as electrical transport, high resolution transmission electron...

  17. Stability of uranium silicides during high energy ion irradiation

    International Nuclear Information System (INIS)

    Birtcher, R.C; Wang, L.M.

    1991-11-01

    Changes induced by 1.5 MeV Kr ion irradiation of both U 3 Si and U 3 Si 2 have been followed by in situ transmission electron microscopy. When irradiated at sufficiently low temperatures, both alloys transform from the crystalline to the amorphous state. When irradiated at temperatures above the temperature limit for ion beam amorphization, both compounds disorder with the Martensite twin structure in U 3 Si disappearing from view in TEM. Prolonged irradiation of the disordered crystalline phases results in nucleation of small crystallites within the initially large crystal grains. The new crystallites increase in number during continued irradiation until a fine grain structure is formed. Electron diffraction yields a powder-like diffraction pattern that indicates a random alignment of the small crystallites. During a second irradiation at lower temperatures, the small crystallizes retard amorphization. After 2 dpa at high temperatures, the amorphization dose is increased by over twenty times compared to that of initially unirradiated material

  18. Aspect Ratio Scaling of Ideal No-wall Stability Limits in High Bootstrap Fraction Tokamak Plasmas

    International Nuclear Information System (INIS)

    Menard, J.E.; Bell, M.G.; Bell, R.E.; Gates, D.A.; Kaye, S.M.; LeBlanc, B.P.; Maingi, R.; Sabbagh, S.A.; Soukhanovskii, V.; Stutman, D.

    2003-01-01

    Recent experiments in the low aspect ratio National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40 (2000) 557] have achieved normalized beta values twice the conventional tokamak limit at low internal inductance and with significant bootstrap current. These experimental results have motivated a computational re-examination of the plasma aspect ratio dependence of ideal no-wall magnetohydrodynamic stability limits. These calculations find that the profile-optimized no-wall stability limit in high bootstrap fraction regimes is well described by a nearly aspect ratio invariant normalized beta parameter utilizing the total magnetic field energy density inside the plasma. However, the scaling of normalized beta with internal inductance is found to be strongly aspect ratio dependent at sufficiently low aspect ratio. These calculations and detailed stability analyses of experimental equilibria indicate that the nonrotating plasma no-wall stability limit has been exceeded by as much as 30% in NSTX in a high bootstrap fraction regime

  19. Structural stability of the smectite-doped lanthanum under high pressures and high temperatures

    International Nuclear Information System (INIS)

    Stefani, Vicente Fiorini

    2012-01-01

    Smectites are phyllosilicates that have a tetrahedron: octahedron structure ratio of 2:1, with high cation exchange capacity (CEC) in the interlayers. For these and other features, smectites have been used in many parts of the world as secondary barriers with the goal of containing a possible leak of radioactive elements in final disposal facilities for radioactive waste through cation exchange. Our aim in this work is to reach the cation exchange in calcium montmorillonite (smectite dioctahedral) by lanthanum to simulate trivalent radionuclides and to study the stability of this structure under high pressure and high temperature. To achieve high pressure it was used two different technique: DAC (Diamond Anvil Cell), achieving pressures up to 12GPa at room temperature and hydraulic press with a toroidal chamber profile to achieve pressures up to 7,7GPa and temperatures up to 900 degree C. The heating is achieved simultaneously by an electric system coupled in the hydraulic press. The outcomes show that the smectite structure doped with lanthanum remains stable under 12GPa at room temperature and 2.5GPa at 200 degree C. However, above 300 degree C at 2.5GPa the structure becomes a new phase of muscovite-like, rich of La, where it loses its interlayer water and turns out to be irreversible. Furthermore, it is important to point out that the higher temperature the better ordered is the structure and it is still stable under 7.7GPa and 900 degree C. Moreover, after all experiments the structure continues being dioctahedral. The new phase of muscovite-like, rich of La, in contact with a calcium solution remains partially unchanged, whereas the other part returns to the original structure (montmorillonite-Ca). The following analyses were performed: X-ray diffraction (XRD) for evaluating the spatial structure; Fourier transform infrared spectroscopy (FTIR) for getting information about the vibrational modes; scanning electron microscopy with dispersive Xray spectroscopy

  20. Effect of fragrance use on discrimination of individual body odor

    Science.gov (United States)

    Allen, Caroline; Havlíček, Jan; Roberts, S. Craig

    2015-01-01

    Previous research suggests that artificial fragrances may be chosen to complement or enhance an individual’s body odor, rather than simply masking it, and that this may create an odor blend with an emergent quality that is perceptually distinguishable from body odor or fragrance alone. From this, it can be predicted that a new emergent odor might be more easily identified than an individual’s body odor in isolation. We used a triangle test paradigm to assess whether fragrance affects people’s ability to distinguish between individual odors. Six male and six female donors provided axillary odor samples in three conditions (without fragrance, wearing their own fragrance, and wearing an assigned fragrance). In total, 296 female and 131 male participants selected the odd one from three odor samples (two from one donor, one from another; both of the same sex). We found that participants could discriminate between the odors at above chance levels in all three odor conditions. Olfactory identification ability (measured using Sniffin’ Sticks) positively predicted discrimination performance, and sex differences in performance were also observed, with female raters being correct more often than men. Success rates were also higher for odors of male donors. Additionally, while performance was above chance in all conditions, individual odor discrimination varied across the three conditions. Discrimination rate was significantly higher in the “no fragrance” condition than either of the fragranced conditions. Importantly, however, discrimination rate was also significantly higher in the “own fragrance” condition than the “assigned fragrance” condition, suggesting that naturally occurring variance in body odor is more preserved when blended with fragrances that people choose for themselves, compared with other fragrances. Our data are consistent with the idea that fragrance choices are influenced by fragrance interactions with an individual’s own body odor

  1. Enzyme-polymer composites with high biocatalytic activity and stability

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jungbae; Kosto, Timothy J.; Manimala, Joseph C.; Nauman, E B.; Dordick, Jonathan S.

    2004-08-22

    We have applied vacuum-spraying and electrospinning to incorporate an enzyme into a polymer matrix, creating a novel and highly active biocatalytic composite. As a unique technical approach, enzymes were co-dissolved in toluene with polymers, and the solvent was then rapidly removed by injecting the mixture into a vacuum chamber or by electrospinning. Subsequent crosslinking of the enzyme with glutaraldehyde resulted in stable entrapped enzyme within the polymeric matrices. For example, an amorphous composite of alpha-chymotrypsin and polyethylene showed no significant loss of enzymatic activity in aqueous buffer for one month. Nanofibers of alpha-chymotrypsin and polystyrene also showed no decrease in activity for more than two weeks. The normalized activity of amorphous composite in organic solvents was 3-13 times higher than that of native alpha-chymotrypsin. The activity of nanofibers was 5-7 times higher than that of amorphous composite in aqueous buffer solution. The composites of alpha-chymotrypsin and polymers demonstrate the feasibility of obtaining a wide variety of active and stable biocatalytic materials with many combinations of enzymes and polymers.

  2. Stability control for high speed tracked unmanned vehicles

    Science.gov (United States)

    Pape, Olivier; Morillon, Joel G.; Houbloup, Philippe; Leveque, Stephane; Fialaire, Cecile; Gauthier, Thierry; Ropars, Patrice

    2005-05-01

    The French Military Robotic Study Program (introduced in Aerosense 2003), sponsored by the French Defense Procurement Agency and managed by Thales as the prime contractor, focuses on about 15 robotic themes which can provide an immediate "operational add-on value". The paper details the "automatic speed adjustment" behavior (named SYR4), developed by Giat Industries Company, which main goal is to secure the teleoperated mobility of high speed tracked vehicles on rough grounds; more precisely, the validated low level behavior continuously adjusts the vehicle speed taking into account the teleperator wish AND the maximum speed that the vehicle can manage safely according to the commanded radius of curvature. The algorithm is based on a realistic physical model of the ground-tracks relation, taking into account many vehicle and ground parameters (such as ground adherence and dynamic specificities of tracked vehicles). It also deals with the teleoperator-machine interface, providing a balanced strategy between both extreme behaviors: a) maximum speed reduction before initiating the commanded curve; b) executing the minimum possible radius without decreasing the commanded speed. The paper presents the results got from the military acceptance tests performed on tracked SYRANO vehicle (French Operational Demonstrator).

  3. Small-angle stability analysis of a linear control system for a high power communication satellite

    Science.gov (United States)

    Omalley, T. A.

    1972-01-01

    A small angle stability analysis is presented for one particular configuration of a high power communication satellite having a linear control system. Both the central body and the solar array are treated as rigid bodies. The control system studied consists of three-axis control of the central body and one-axis control of the solar array rotation relative to the central body. The results yield preliminary indications of the relation of stability to satellite inertias and control gains.

  4. MHD stability calculations of high-β quasi-axisymmetric stellarators

    International Nuclear Information System (INIS)

    Fu, G.Y.; Ku, L.P.; Pomphrey, N.; Redi, M.; Kessel, C.; Monticello, D.; Reiman, A.; Hughes, M.; Cooper, W.A.; Nuehrenberg, C.

    2001-01-01

    The MHD stability of quasi-axisymmetric compact stellarators is investigated. It is shown that bootstrap current driven external kink modes can be stabilized by a combination of edge magnetic shear and appropriate 3D plasma boundary shaping while maintaining good quasi-axisymmetry. The results demonstrate that there exists a new class of stellarators with quasi-axisymmetry, large bootstrap current, high MHD beta limit, and compact size. (author)

  5. MHD Stability Calculations of High-Beta Quasi-Axisymmetric Stellarators

    International Nuclear Information System (INIS)

    Kessel, C.; Fu, G.Y.; Ku, L.P.; Redi, M.H.; Pomphrey, N.

    1999-01-01

    The MHD stability of quasi-axisymmetric compact stellarators is investigated. It is shown that bootstrap current driven external kink modes can be stabilized by a combination of edge magnetic shear and appropriate 3D plasma boundary shaping while maintaining good quasi-axisymmetry. The results demonstrate that there exists a new class of stellarators with quasi-axisymmetry, large bootstrap current, high MHD beta limit, and compact size

  6. MHD stability calculations of high-β quasi-axisymmetric stellarators

    International Nuclear Information System (INIS)

    Fu, G.Y.; Ku, L.P.; Pomphrey, N.; Redi, M.H.; Kessel, C.; Monticello, D.A.; Reiman, A.; Hughes, M.; Cooper, W.A.; Nuehrenberg, C.

    1999-01-01

    The MHD stability of quasi-axisymmetric compact stellarators is investigated. It is shown that bootstrap current driven external kink modes can be stabilized by a combination of edge magnetic shear and appropriate 3D plasma boundary shaping while maintaining good quasi-axisymmetry. The results demonstrate that there exists a new class of stellarators with quasi-axisymmetry, large bootstrap current, high MHD beta limit, and compact size. (author)

  7. Geometrical improvements of rotational stabilization of high-n ballooning modes in tokamaks

    International Nuclear Information System (INIS)

    Furukawa, Masaru; Tokuda, S.

    2003-01-01

    We have found numerically that damping phases appear in the time evolution of the perturbation energy of high-n ballooning modes in the presence of toroidal shear flows. The damping dominates exponential growth which occurs in the bad curvature region, resulting in stabilization of ballooning modes. D-shaping of plasma cross-section, reduction of aspect ratio, and arrangement of X-point at inner side of the torus enhance the stabilization effect of the toroidal flow through this mechanism. (author)

  8. Ilmenite Nanotubes for High Stability and High Rate Sodium-Ion Battery Anodes.

    Science.gov (United States)

    Yu, Litao; Liu, Jun; Xu, Xijun; Zhang, Liguo; Hu, Renzong; Liu, Jiangwen; Ouyang, Liuzhang; Yang, Lichun; Zhu, Min

    2017-05-23

    To solve the problem of large volume change and low electronic conductivity of earth-abundant ilmenite used in rechargeable Na-ion batteries (SIBs), an anode of tiny ilmenite FeTiO 3 nanoparticle embedded carbon nanotubes (FTO⊂CNTs) has been successfully proposed. By introducing a TiO 2 shell on metal-organic framework (Fe-MOF) nanorods by sol-gel deposition and subsequent solid-state annealing treatment of these core-shell Fe-MOF@TiO 2 , such well-defined FTO⊂CNTs are obtained. The achieved FTO⊂CNT electrode has several distinct advantages including a hollow interior in the hybrid nanostructure, fully encapsulated ultrasmall electroactive units, flexible conductive carbon matrix, and stable solid electrolyte interface (SEI) of FTO in cycles. FTO⊂CNT electrodes present an excellent cycle stability (358.8 mA h g -1 after 200 cycles at 100 mA g -1 ) and remarkable rate capability (201.8 mA h g -1 at 5000 mA g -1 ) with a high Coulombic efficiency of approximately 99%. In addition, combined with the typical Na 3 V 2 (PO 4 ) 3 cathode to constitute full SIBs, the assembled FTO⊂CNT//Na 3 V 2 (PO 4 ) 3 batteries are also demonstrated with superior rate capability and a long cycle life.

  9. Exciplex-Forming Cohost for High Efficiency and High Stability Phosphorescent Organic Light-Emitting Diodes.

    Science.gov (United States)

    Shih, Chun-Jen; Lee, Chih-Chien; Chen, Ying-Hao; Biring, Sajal; Kumar, Gautham; Yeh, Tzu-Hung; Sen, Somaditya; Liu, Shun-Wei; Wong, Ken-Tsung

    2018-01-17

    An exciplex forming cohost system is employed to achieve a highly efficient organic light-emitting diode (OLED) with good electroluminescent lifetime. The exciplex is formed at the interfacial contact of a conventional star-shaped carbazole hole-transporting material, 4,4',4″-tris(N-carbazolyl)-triphenylamine (TCTA), and a triazine electron-transporting material, 2,4,6-tris[3-(1H-pyrazol-1-yl)phenyl]-1,3,5-triazine (3P-T2T). The excellent combination of TCTA and 3P-T2T is applied as the cohost of a common green phosphorescent emitter with almost zero energy loss. When Ir(ppy) 2 (acac) is dispersed in such exciplex cohost system, OLED device with maximum external quantum efficiency of 29.6%, the ultrahigh power efficiency of 147.3 lm/W, and current efficiency of 107 cd/A were successfully achieved. More importantly, the OLED device showed a low-efficiency roll-off and an operational lifetime (τ 80 ) of ∼1020 min with the initial brightness of 2000 cd/m 2 , which is 56 times longer than the reference device. The significant difference of device stability was attributed to the degradation of exciplex system for energy transfer process, which was investigated by the photoluminescence aging measurement at room temperature and 100 K, respectively.

  10. Indirect high-bandwidth stabilization of carrier-envelope phase of a high-energy, low-repetition-rate laser.

    Science.gov (United States)

    Fu, Yuxi; Takahashi, Eiji J; Midorikawa, Katsumi

    2016-06-13

    We demonstrate a method of stabilizing the carrier-envelope phase (CEP) of low-repetition-rate, high-energy femtosecond laser systems such as TW-PW class lasers. A relatively weak high-repetition-rate (~1 kHz) reference pulse copropagates with a low-repetition-rate (10 Hz) high-energy pulse, which are s- and p-polarized, respectively. Using a Brewster angle window, the reference pulse is separated after the power amplifier and used for feedback to stabilize its CEP. The single-shot CEP of the high-energy pulse is indirectly stabilized to 550 mrad RMS, which is the highest CEP stability ever reported for a low-repetition-rate (10-Hz) high-energy laser system. In this novel method, the feedback frequency of the reference pulse from the front-end preamplifier can be almost preserved. Thus, higher CEP stability can be realized than for lower frequencies. Of course, a reference pulse with an even higher repetition rate (e.g., 10 kHz) can be easily employed to sample and feed back CEP jitter over a broader frequency bandwidth.

  11. Responsivity to two odorants, androstenone and amyl acetate, and the affective impact of odors on interpersonal relationships.

    Science.gov (United States)

    Pierce, John D; Cohen, Adam B; Ulrich, Patricia M

    2004-03-01

    Substantial variation exists in the importance of olfaction in influencing individuals' preferences, yet the sources of this variation remain elusive. The authors explored responsivity to 2 odorants as 1 potential source. Participants (N = 258) completed the Affective Impact of Odor Scale and were assessed for responsivity to the putative human pheromone androstenone and amyl acetate. Results showed a significant relationship between odorant responsivity and self-reports of the influence of odors. People able to smell androstenone more commonly reported odors as having a negative effect on interpersonal relationships than did people anosmic to androstenone, whereas responsivity to amyl acetate was associated with positive effects of odors on relationships. Responsivity to certain odorants may be an important factor affecting human social interactions. ((c) 2004 APA, all rights reserved)

  12. Characterization of odorous contaminants in post-consumer plastic packaging waste using multidimensional gas chromatographic separation coupled with olfactometric resolution.

    Science.gov (United States)

    Strangl, Miriam; Fell, Tanja; Schlummer, Martin; Maeurer, Andreas; Buettner, Andrea

    2017-04-01

    The increasing world population with their growing consumption of goods escalates the issue of sustainability concepts with increasing demands in recycling technologies. Recovery of post-consumer packaging waste is a major topic in this respect. However, contamination with odorous constituents currently curtails the production of recycling products that meet the high expectations of both consumers and industry. To guarantee odor-free recyclates, the main prerequisite is to characterize the molecular composition of the causative odorants in post-consumer plastic packaging waste. However, targeted characterization of odorous trace contaminants among an abundance of volatiles is a major challenge and requires specialized and high-resolution analytical approaches. For this aim, post-consumer packaging waste was characterized by sensory analysis and two-dimensional high resolution gas chromatography coupled with mass spectrometry and olfactometry. The 33 identified odorants represent various structural classes as well as a great diversity of smell impressions with some of the compounds being identified in plastics for the first time. Substances unraveled within this study provide insights into sources of odorous contamination that will require specific attention in the future in terms of screening and prevention in recycling products. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. High temperature stability of onion-like carbon vs highly oriented pyrolytic graphite.

    Directory of Open Access Journals (Sweden)

    Alessandro Latini

    Full Text Available The thermodynamic stability of onion-like carbon (OLC nanostructures with respect to highly oriented pyrolytic graphite (HOPG was determined in the interval 765-1030 K by the electromotive force (emf measurements of solid electrolyte galvanic cell: (Low Pt|Cr3C2,CrF2,OLC|CaF2s.c.|Cr3C2,CrF2,HOPG|Pt (High. The free energy change of transformation HOPG = OLC was found positive below 920.6 K crossing the zero value at this temperature. Its trend with temperature was well described by a 3rd degree polynomial. The unexpected too high values of [Formula: see text] jointly to the HR-TEM, STEM and EELS evidences that showed OLC completely embedded in rigid cages made of a Cr3C2/CrF2 matrix, suggested that carbon in the electrodes experienced different internal pressures. This was confirmed by the evaluation under constant volume of [dP/dT by the α/κ ratio for OLC (0.5 MPa K(-1 and HOPG (8 Pa K(-1 where α and κ are the isobaric thermal expansion and isothermal compressibility coefficients, respectively. The temperature dependency of the pressure was derived and utilized to calculate the enthalpy and entropy changes as function of temperature and pressure. The highest value of the internal pressure experienced by OLC was calculated to be about 7 GPa at the highest temperature. At 920.6 K, ΔrH and ΔrS values are 95.8 kJ mol(-1 and 104.1 JK(-1 mol(-1, respectively. The surface contributions to the energetic of the system were evaluated and they were found negligible compared with the bulk terms. As a consequence of the high internal pressure, the values of the enthalpy and entropy changes were mainly attributed to the formation of carbon defects in OLC considered as multishell fullerenes. The change of the carbon defect fraction is reported as a function of temperature.

  14. Orbital Stability of Multi-Planet Systems: Behavior at High Masses

    Science.gov (United States)

    Morrison, Sarah J.; Kratter, Kaitlin M.

    2015-12-01

    We explore the relationships between planet separation, mass, and stability timescale in high mass multi-planet systems containing planet masses and multiplicities relevant for planetary systems detectable via direct imaging. Extrapolating empirically derived relationships between planet mass, separation, and stability timescale derived from lower mass planetary systems misestimate the stability timescales for higher mass planetary systems by more than an order of magnitude at close separations near the two body Hill stability limit. We also find that characterizing critical separations in terms of period ratio produces a linear relationship between log-timescale and separation with the same slope for planet-star mass ratios comparable to or exceeding Jupiter’s, but this slope steepens for lower mass planetary systems. We discuss possible mechanisms for instability that result in this behavior including perturbing adjacent planet pairs into an overlap regime between 1st and sometimes 2nd order mean motion resonances.

  15. Effect of fragrance use on discrimination of individual body odor

    Directory of Open Access Journals (Sweden)

    Caroline eAllen

    2015-08-01

    Full Text Available Previous research suggests that artificial fragrances may be chosen to complement or enhance an individual’s body odor, rather than simply masking it, and that this may create an odor blend with an emergent quality that is perceptually distinguishable from body odor or fragrance alone. From this, it can be predicted that a new emergent odor might be more easily identified than an individual’s body odor in isolation. We used a triangle test paradigm to assess whether fragrance affects people’s ability to distinguish between individual odors. Six male and six female donors provided axillary odor samples in three conditions (without fragrance, wearing their own fragrance, and wearing an assigned fragrance. In total, 296 female and 131 male participants selected the odd one out from three odor samples (two from one donor, one from another; both of the same sex. We found that participants could discriminate between the odors at above chance levels in all three odour conditions. Olfactory identification ability (measured using Sniffin’ Sticks positively predicted discrimination performance, and sex differences in performance were also observed, with female raters being correct more often than men. Success rates were also higher for odors of male donors. Additionally, while performance was above chance in all conditions, individual odor discrimination varied across the three conditions. Discrimination rate was significantly higher in the ‘no fragrance’ condition than either of the fragranced conditions. Importantly, however, discrimination rate was also significantly higher in the ‘own fragrance’ condition than the ‘assigned fragrance’ condition, suggesting that naturally occurring variance in body odor is more preserved when blended with fragrances that people choose for themselves, compared with other fragrances. Our data are consistent with the idea that fragrance choices are influenced by fragrance interactions with an

  16. Body odor based personality judgments: The effect of fragranced cosmetics

    Directory of Open Access Journals (Sweden)

    Agnieszka eSorokowska

    2016-04-01

    Full Text Available People can accurately assess various personality traits of others based on body odor alone. Previous studies have shown that correlations between odor ratings and self-assessed personality dimensions are evident for assessments of neuroticism and dominance. Here, we tested differences between assessments based on natural body odor alone, without the use of cosmetics and assessments based on the body odor of people who were allowed to use cosmetics following their daily routine. Sixty-seven female observers assessed samples of odors from 113 odor donors (each odor donor provided two samples – one with and one without cosmetic use; the donors provided their personality ratings, and the raters judged personality characteristics of the donors based on the provided odor samples. Correlations between observers’ ratings and self-rated neuroticism were stronger when raters assessed body odor in the natural body odor condition (natural BO condition; rs = .20 than in the cosmetics use condition (BO+cosmetics condition; rs = .15. Ratings of dominance significantly predicted self-assessed dominance in both conditions (rs = .34 for natural BO and rs = .21 for BO+cosmetics, whereas ratings of extraversion did not predict self-assessed extraversion in either condition. In addition, ratings of body odor attractiveness and pleasantness were significantly lower in natural BO condition than in BO+cosmetics condition, although the intensity of donors’ body odors was similar under both conditions. Our findings suggest that although olfaction seems to contribute to accurate first impression judgments of certain personality traits, cosmetic use can affect assessments of others based on body odor.

  17. Colorimetric sensor for bad odor detection using automated color correction

    Science.gov (United States)

    Schmitt, K.; Tarantik, K.; Pannek, C.; Benito-Altamirano, I.; Casals, O.; Fàbrega, C.; Romano-Rodríguez, A.; Wöllenstein, J.; Prades, J. D.

    2017-06-01

    Colorimetric sensors based on color-changing dyes offer a convenient approach for the quantitative measurement of gases. An integrated, mobile colorimetric sensor can be particularly helpful for occasional gas measurements, such as informal air quality checks for bad odors. In these situations, the main requirement is high availability, easy usage, and high specificity towards one single chemical compound, combined with cost-efficient production. In this contribution, we show how a well stablished colorimetric method can be adapted for easy operation and readout, making it suitable for the untrained end user. As an example, we present the use of pH indicators for the selective and reversible detection of NH3 in air (one relevant gas contributing to bad odors) using gas-sensitive layers dip coated on glass substrates. Our results show that the method can be adapted to detect NH3 concentrations lower than 1 ppm, with measure-to-result times in the range of a few minutes. We demonstrate that the color measurements can be carried out with the optical signals of RGB sensors, without losing quantitative performance.

  18. Sensitivity of boundary-layer stability to base-state distortions at high Mach numbers

    Science.gov (United States)

    Park, Junho; Zaki, Tamer

    2017-11-01

    The stability diagram of high-speed boundary layers has been established by evaluating the linear instability modes of the similarity profile, over wide ranges of Reynolds and Mach numbers. In real flows, however, the base state can deviate from the similarity profile. Both the base velocity and temperature can be distorted, for example due to roughness and thermal wall treatments. We review the stability problem of high-speed boundary layer, and derive a new formulation of the sensitivity to base-state distortion using forward and adjoint parabolized stability equations. The new formulation provides qualitative and quantitative interpretations on change in growth rate due to modifications of mean-flow and mean-temperature in heated high-speed boundary layers, and establishes the foundation for future control strategies. This work has been funded by the Air Force Office of Scientific Research (AFOSR) Grant: FA9550-16-1-0103.

  19. Optimal swarm formation for odor plume finding.

    Science.gov (United States)

    Marjovi, Ali; Marques, Lino

    2014-12-01

    This paper presents an analytical approach to the problem of odor plume finding by a network of swarm robotic gas sensors, and finds an optimal configuration for them, given a set of assumptions. Considering cross-wind movement for the swarm, we found that the best spatial formation of robots in finding odor plumes is diagonal line configuration with equal distance between each pair of neighboring robots. We show that the distance between neighboring pairs in the line topology depends mainly on the wind speed and the environmental conditions, whereas, the number of robots and the swarm's crosswind movement distance do not show significant impact on optimal configurations. These solutions were analyzed and verified by simulations and experimentally validated in a reduced scale realistic environment using a set of mobile robots.

  20. Odor concentration invariance by chemical ratio coding

    Directory of Open Access Journals (Sweden)

    Naoshige Uchida

    2008-08-01

    Full Text Available Many animal species rely on chemical signals to extract ecologically important information from the environment. Yet in natural conditions chemical signals will frequently undergo concentration changes that produce differences in both level and pattern of activation of olfactory receptor neurons. Thus, a central problem in olfactory processing is how the system is able to recognize the same stimulus across different concentrations. To signal species identity for mate recognition, some insects use the ratio of two components in a binary chemical mixture to produce a code that is invariant to dilution. Here, using psychophysical methods, we show that rats also classify binary odor mixtures according to the molar ratios of their components, spontaneously generalizing over at least a tenfold concentration range. These results indicate that extracting chemical ratio information is not restricted to pheromone signaling and suggest a general solution for concentration-invariant odor recognition by the mammalian olfactory system.

  1. Selectivity of Odorant Receptors in Insects

    Science.gov (United States)

    2012-07-13

    shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1...mosquito Culex pipiens quin- quefasciatus sensitive to oviposition attractants. PLoS ONE 5, e10090. doi: 10.1371/journal.pone.0010090 Sato, K...Insect Biochem. Mol. Biol. 38, 770–780. Syed, Z., and Leal, W. S. (2007). Max- illary palps are broad spectrum odorant detectors in Culex quinque

  2. Structural stability of binary CdCa quasicrystal under high pressure

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Gerward, Leif; Olsen, J. S.

    2001-01-01

    The structural stability of a binary CdCa quasicrystal with a primitive icosahedral structure has been investigated by in situ high-pressure x-ray powder diffraction at an ambient temperature using synchrotron radiation. It is demonstrated that the icosahedral quasicrystalline structure of the sa......The structural stability of a binary CdCa quasicrystal with a primitive icosahedral structure has been investigated by in situ high-pressure x-ray powder diffraction at an ambient temperature using synchrotron radiation. It is demonstrated that the icosahedral quasicrystalline structure...... elasticity in the stable binary icosahedral CdCa quasicrystals....

  3. BWR stability: analysis of cladding temperature for high amplitude oscillations - 146

    International Nuclear Information System (INIS)

    Pohl, P.; Wehle, F.

    2010-01-01

    Power oscillations associated with density waves in boiling water reactors (BWRs) have been studied widely. Industrial research in this area is active since the invention of the first BWR. Stability measurements have been performed in various plants during commissioning phase but especially the magnitude and divergent nature of the oscillations during the LaSalle Unit 2 nuclear power plant event on March 9, 1988, renewed concern about the state of knowledge on BWR instabilities and possible consequences to fuel rod integrity. The objective of this paper is to present a simplified stability tool, applicable for stability analysis in the non-linear regime, which extends to high amplitude oscillations where inlet reverse flow occurs. In case of high amplitude oscillations a cyclical dryout and rewetting process at the fuel rod may take place, which leads in turn to rapid changes of the heat transfer from the fuel rod to the coolant. The application of this stability tool allows for a conservative determination of the fuel rod cladding temperature in case of high amplitude oscillations during the dryout / re-wet phase. Moreover, it reveals in good agreement to experimental findings the stabilizing effect of the reverse bundle inlet flow, which might be obtained for large oscillation amplitudes. (authors)

  4. Biopolymer-stabilized Pt nanoparticles colloid: a highly active and recyclable catalyst for biphasic catalysis

    International Nuclear Information System (INIS)

    Wang, Yujia; Shen, Yueyue; Qiu, Yunfei; Zhang, Ting; Liao, Yang; Zhao, Shilin; Ma, Jun; Mao, Hui

    2016-01-01

    Noble metal nanoparticles are promising candidates to replace conventional bulk counterparts owing to their high activity and selectivity. To enable catalyst recovery, noble metal nanoparticles are often supported onto solid matrices to prepare heterogeneous catalyst. Although recycle of noble metal nanoparticles is realized by heterogenization, a loss of activity is usually encountered. In the present investigation, Pt nanoparticles with tunable particle size (1.85–2.80 nm) were facilely prepared by using polyphenols as amphiphilic stabilizers. The as-prepared Pt nanoparticles colloid solution could be used as highly active catalyst in aqueous–organic biphasic catalysis. The phenolic hydroxyls of polyphenols could constrain Pt nanoparticles in aqueous phase, and simultaneously, the aromatic scaffold of polyphenols ensured effective interactions between substrates and Pt nanoparticles. As a consequence, the obtained polyphenols-stabilized Pt nanoparticles exhibited high activity and cycling stability in biphasic hydrogenation of a series of unsaturated compounds. Compared with conventional heterogeneous Pt-C and Pt-Al 2 O 3 catalysts, polyphenols-stabilized Pt nanoparticles showed obvious advantage both in activity and cycling stability.

  5. Quantitative method to determine the regional drinking water odorant regulation goals based on odor sensitivity distribution: illustrated using 2-MIB.

    Science.gov (United States)

    Yu, Jianwei; An, Wei; Cao, Nan; Yang, Min; Gu, Junong; Zhang, Dong; Lu, Ning

    2014-07-01

    Taste and odor (T/O) in drinking water often cause consumer complaints and are thus regulated in many countries. However, people in different regions may exhibit different sensitivities toward T/O. This study proposed a method to determine the regional drinking water odorant regulation goals (ORGs) based on the odor sensitivity distribution of the local population. The distribution of odor sensitivity to 2-methylisoborneol (2-MIB) by the local population in Beijing, China was revealed by using a normal distribution function/model to describe the odor complaint response to a 2-MIB episode in 2005, and a 2-MIB concentration of 12.9 ng/L and FPA (flavor profile analysis) intensity of 2.5 was found to be the critical point to cause odor complaints. Thus the Beijing ORG for 2-MIB was determined to be 12.9 ng/L. Based on the assumption that the local FPA panel can represent the local population in terms of sensitivity to odor, and that the critical FPA intensity causing odor complaints was 2.5, this study tried to determine the ORGs for seven other cities of China by performing FPA tests using an FPA panel from the corresponding city. ORG values between 12.9 and 31.6 ng/L were determined, showing that a unified ORG may not be suitable for drinking water odor regulations. This study presents a novel approach for setting drinking water odor regulations. Copyright © 2014. Published by Elsevier B.V.

  6. SMELL-S and SMELL-R: Olfactory tests not influenced by odor-specific insensitivity or prior olfactory experience.

    Science.gov (United States)

    Hsieh, Julien W; Keller, Andreas; Wong, Michele; Jiang, Rong-San; Vosshall, Leslie B

    2017-10-24

    Smell dysfunction is a common and underdiagnosed medical condition that can have serious consequences. It is also an early biomarker of neurodegenerative diseases, including Alzheimer's disease, where olfactory deficits precede detectable memory loss. Clinical tests that evaluate the sense of smell face two major challenges. First, human sensitivity to individual odorants varies significantly, so test results may be unreliable in people with low sensitivity to a test odorant but an otherwise normal sense of smell. Second, prior familiarity with odor stimuli can bias smell test performance. We have developed nonsemantic tests for olfactory sensitivity (SMELL-S) and olfactory resolution (SMELL-R) that use mixtures of odorants that have unfamiliar smells. The tests can be self-administered by healthy individuals with minimal training and show high test-retest reliability. Because SMELL-S uses odor mixtures rather than a single molecule, odor-specific insensitivity is averaged out, and the test accurately distinguished people with normal and dysfunctional smell. SMELL-R is a discrimination test in which the difference between two stimulus mixtures can be altered stepwise. This is an advance over current discrimination tests, which ask subjects to discriminate monomolecular odorants whose difference in odor cannot be quantified. SMELL-R showed significantly less bias in scores between North American and Taiwanese subjects than conventional semantically based smell tests that need to be adapted to different languages and cultures. Based on these proof-of-principle results in healthy individuals, we predict that SMELL-S and SMELL-R will be broadly effective in diagnosing smell dysfunction. Published under the PNAS license.

  7. Measures of odor and lateralization thresholds of acrolein, crotonaldehyde, and hexanal using a novel vapor delivery technique.

    Science.gov (United States)

    Ernstgård, Lena; Dwivedi, Aishwarya M; Lundström, Johan N; Johanson, Gunnar

    2017-01-01

    Humans are exposed to aldehydes in a variety of environmental situations. Aldehydes generally have a strong odor and are highly irritating to the mucous membranes. Knowledge about odor perception and especially irritation potency in humans is thus essential in risk assessment and regulation, e.g. setting occupational exposure limits. However, data on odor and irritation are lacking or limited for several aldehydes. The aim of the study was to determine the odor and lateralization thresholds of some commonly occurring aldehydes. Acrolein and crotonaldehyde where chosen as they are formed when organic material is heated or burned, e.g. during cigarette smoking. n-Hexanal was also included as it is emitted from wood pellets and fibreboard. To study odor and lateralization thresholds of these aldehydes, a novel, inexpensive olfactometer was designed to enable delivery of reliable and stable test concentrations and thus valid measures of thresholds. The delivery system consists of seven syringe pumps, each connected to a Tedlar bag containing a predefined concentration of the tested aldehyde vapor. To validate the threshold measures, a test-retest was performed with a separate method, namely odor delivery via amber bottles. Twenty healthy naïve individuals were tested. The median odor thresholds of acrolein, crotonaldehyde and hexanal were 17, 0.8, and 97 ppb, respectively. No lateralization threshold could be identified for acrolein (highest tested concentration was 2 940 ppb in 5 subjects), whereas the medians were 3 and 390 ppb for the latter two. In addition, odor thresholds for n-hexanal were also determined using two methods where similar results were obtained, suggesting that the olfactometer presentation method is valid. We found olfactory detection and lateralization thresholds (except for acrolein) in alliance with, or lower than, previously reported in naïve subjects. The new olfactometer allows better control of presentations timing and vapor concentration.

  8. Resolving the chemical structures of off-odorants and potentially harmful substances in toys-example of children's swords.

    Science.gov (United States)

    Denk, Philipp; Velasco-Schön, Cristina; Buettner, Andrea

    2017-09-01

    Most children's toys on the market are primarily made out of plastic and other complex composite materials. Consumer complaints about offensive odors or irritating effects associated with toy products have increased in recent years. One example is the strongly perceivable negative odor reported for a particular series of toy swords. Characterizing the presence of contaminants, including those that have the potential to be deleterious to health, in such products is a significant analytical challenge due to the high baseline abundance of chemical constituents of the materials used in the products. In the present study, the nature of offensive odorants associated with toy sword products was examined by gas chromatography (GC). After initial sensory evaluations, the volatile compounds from the toy products were recovered using solvent extraction and solvent-assisted flavor evaporation. The extracts were analyzed using GC-olfactometry (GC-O) and two-dimensional GC-O coupled with mass spectrometry (GC-GC-MS/O). A total of 26 odor-active compounds, including aromatic hydrocarbons and phenols, were identified among numerous non-odorous volatile by-products. These substances also included polycyclic aromatic hydrocarbons, which were analyzed by GC-MS. Representative substances were naphthalene and 1,2-dihydronaphthalene that exhibited moldy, mothball-like odor impressions, and phenol derivatives with leather-like, phenolic, horse-stable-like smells. The odorants detected correlated with the assigned attributes from the sensory analyses. This study clearly shows that the detection and identification of such odorous contaminants can provide key indications of potentially harmful yet unknown substances in everyday products such as toys. Graphical abstract ᅟ.

  9. Using odor cues to elicit a behavioral and hormonal response in zoo-housed African wild dogs.

    Science.gov (United States)

    Rafacz, Michelle L; Santymire, Rachel M

    2014-01-01

    Olfactory enrichment, like odor cues, can positively affect behavior, reproductive success, and stress physiology in zoo-housed species. Our goal was to determine if odor cues were enriching to the African wild dog (AWD; Lycaon pictus), a species with a complex social structure and a highly developed sense of smell. Our objectives were to: (1) examine changes in activity levels and stress hormone physiology in response to fecal odor cues from natural competitor and natural/unnatural prey species; and (2) determine whether these odor cues could function as effective enrichment for zoo-housed AWDs. Over a 6-month period, fecal samples were collected from two males (AWD 1: dominant, AWD 2: subordinate), fecal glucocorticoid metabolites (FGMs) were validated using an ACTH-challenge, and hormones were analyzed for FGMs by enzyme immunoassay. Behavioral observations were conducted using scan-sampling, and contact and proximity were recorded. AWDs were presented with three fecal odor cues: LION (competitor), CATTLE (unnatural prey), and GAZELLE (natural prey). Only the GAZELLE cue elicited an increase in activity (10.6%) in both individuals and increased positive social behaviors with higher frequencies of affiliative, submissive, and dominant behavior. AWD 1 demonstrated lower (P odor cues, and FGMs decreased (P = 0.08) in AWD 2 after all cues. We conclude that exposure to natural prey odor cues may be used as effective enrichment for AWDs, and that changes in stress hormone physiology in response to odor cues may be dependent on social rank in this species. © 2013 Wiley Periodicals, Inc.

  10. Microbial Odor Profile of Polyester and Cotton Clothes after a Fitness Session

    NARCIS (Netherlands)

    Callewaert, C.; De Maeseneire, E.; Kerckhof, F.M.; Verliefde, A.; Van de Wiele, T.; Boon, N.

    2014-01-01

    Clothing textiles protect our human body against external factors. These textiles are not sterile and can harbor high bacterial counts as sweat and bacteria are transmitted from the skin. We investigated the microbial growth and odor development in cotton and synthetic clothing fabrics. T-shirts

  11. Optimization of a pressure control valve for high power automatic transmission considering stability

    Science.gov (United States)

    Jian, Hongchao; Wei, Wei; Li, Hongcai; Yan, Qingdong

    2018-02-01

    The pilot-operated electrohydraulic clutch-actuator system is widely utilized by high power automatic transmission because of the demand of large flowrate and the excellent pressure regulating capability. However, a self-excited vibration induced by the inherent non-linear characteristics of valve spool motion coupled with the fluid dynamics can be generated during the working state of hydraulic systems due to inappropriate system parameters, which causes sustaining instability in the system and leads to unexpected performance deterioration and hardware damage. To ensure a stable and fast response performance of the clutch actuator system, an optimal design method for the pressure control valve considering stability is proposed in this paper. A non-linear dynamic model of the clutch actuator system is established based on the motion of the valve spool and coupling fluid dynamics in the system. The stability boundary in the parameter space is obtained by numerical stability analysis. Sensitivity of the stability boundary and output pressure response time corresponding to the valve parameters are identified using design of experiment (DOE) approach. The pressure control valve is optimized using particle swarm optimization (PSO) algorithm with the stability boundary as constraint. The simulation and experimental results reveal that the optimization method proposed in this paper helps in improving the response characteristics while ensuring the stability of the clutch actuator system during the entire gear shift process.

  12. A specialized odor memory buffer in primary olfactory cortex.

    Science.gov (United States)

    Zelano, Christina; Montag, Jessica; Khan, Rehan; Sobel, Noam

    2009-01-01

    The neural substrates of olfactory working memory are unknown. We addressed the questions of whether olfactory working memory involves a verbal representation of the odor, or a sensory image of the odor, or both, and the location of the neural substrates of these processes. We used functional magnetic resonance imaging to measure activity in the brains of subjects who were remembering either nameable or unnameable odorants. We found a double dissociation whereby remembering nameable odorants was reflected in sustained activity in prefrontal language areas, and remembering unnameable odorants was reflected in sustained activity in primary olfactory cortex. These findings suggest a novel dedicated mechanism in primary olfactory cortex, where odor information is maintained in temporary storage to subserve ongoing tasks.

  13. Assessment and remediation of odor emissions from a complex industrial facility (Ambient air odor regulations in Canada and the United States)

    International Nuclear Information System (INIS)

    Boose, T.; Reusing, G.

    2002-01-01

    This paper describes the findings of a review and presents examples of ambient air odor regulations in Canada and the United States. State and provincial odor regulations were reviewed and other metropolitan cities or counties (regions) that have separate odor regulations were also included. The key topics addressed in this paper include an assessment of the methods used for odor regulation and the methods used to evaluate the odor impact to determine compliance with the regulation. Three types of ambient air odor regulations were identified: 1. 28 States, Provinces and regions (jurisdictions) have specific odor regulations. These regulations generally define what constitutes an odor impact and typically provide requirements for remedial measures; 2. 25 jurisdictions regulate odors by a general prohibition regulation. These regulations define odor in ambient air as a condition of air pollution, nuisance or objectionable odor that would typically prevent persons from the enjoyment of life and property; and 3. 13 jurisdictions do not have specific or general prohibition regulations regarding odors. For the jurisdictions that have specific or general prohibition odor regulations, there are a number of different techniques used to define what constitutes an odor impact. Odor impacts are typically defined in a regulation by one (or more) of the following techniques: dilution to threshold, or odor unit limit; determination of odor emission rates; odor concentration limits for selected chemicals (ppm); comparison with the n-butanol intensity scale (1 to 8); and investigation by an agency investigator. Compliance with odor regulations is typically determined using one (or more) of the following field methods: odor stack testing and dispersion modelling; odor panel analysis of stack or ambient air samples; chemical monitoring (ppm); odor school certified / agency investigator; and scentometer. (author)

  14. Engineering a highly active thermophilic ?-glucosidase to enhance its pH stability and saccharification performance

    OpenAIRE

    Xia, Wei; Xu, Xinxin; Qian, Lichun; Shi, Pengjun; Bai, Yingguo; Luo, Huiying; Ma, Rui; Yao, Bin

    2016-01-01

    Background ?-Glucosidase is an important member of the biomass-degrading enzyme system, and plays vital roles in enzymatic saccharification for biofuels production. Candidates with high activity and great stability over high temperature and varied pHs are always preferred in industrial practice. To achieve cost-effective biomass conversion, exploring natural enzymes, developing high level expression systems and engineering superior mutants are effective approaches commonly used. Results A new...

  15. Influence of dispersing additives and blend composition on stability of marine high-viscosity fuels

    Directory of Open Access Journals (Sweden)

    Т. Н. Митусова

    2017-12-01

    Full Text Available The article offers a definition of the stability of marine high-viscosity fuel from the point of view of the colloid-chemical concept of oil dispersed systems. The necessity and importance of the inclusion in the current regulatory requirements of this quality parameter of high-viscosity marine fuel is indicated. The objects of the research are high-viscosity marine fuels, the basic components of which are heavy oil residues: fuel oil that is the atmospheric residue of oil refining and viscosity breaking residue that is the product of light thermal cracking of fuel oil. As a thinning agent or distillate component, a light gas oil was taken from the catalytic cracking unit. The stability of the obtained samples was determined through the xylene equivalent index, which characterizes the stability of marine high-viscosity fuel to lamination during storage, transportation and operation processes. To improve performance, the resulting base compositions of high-viscosity marine fuels were modified by introducing small concentrations (0.05 % by weight of stabilizing additives based on oxyethylated amines of domestic origin and alkyl naphthalenes of foreign origin.

  16. Rapid encoding and perception of novel odors in the rat.

    Directory of Open Access Journals (Sweden)

    Daniel W Wesson

    2008-04-01

    Full Text Available To gain insight into which parameters of neural activity are important in shaping the perception of odors, we combined a behavioral measure of odor perception with optical imaging of odor representations at the level of receptor neuron input to the rat olfactory bulb. Instead of the typical test of an animal's ability to discriminate two familiar odorants by exhibiting an operant response, we used a spontaneously expressed response to a novel odorant-exploratory sniffing-as a measure of odor perception. This assay allowed us to measure the speed with which rats perform spontaneous odor discriminations. With this paradigm, rats discriminated and began responding to a novel odorant in as little as 140 ms. This time is comparable to that measured in earlier studies using operant behavioral readouts after extensive training. In a subset of these trials, we simultaneously imaged receptor neuron input to the dorsal olfactory bulb with near-millisecond temporal resolution as the animal sampled and then responded to the novel odorant. The imaging data revealed that the bulk of the discrimination time can be attributed to the peripheral events underlying odorant detection: receptor input arrives at the olfactory bulb 100-150 ms after inhalation begins, leaving only 50-100 ms for central processing and response initiation. In most trials, odor discrimination had occurred even before the initial barrage of receptor neuron firing had ceased and before spatial maps of activity across glomeruli had fully developed. These results suggest a coding strategy in which the earliest-activated glomeruli play a major role in the initial perception of odor quality, and place constraints on coding and processing schemes based on simple changes in spike rate.

  17. Olfactory systems and neural circuits that modulate predator odor fear

    Directory of Open Access Journals (Sweden)

    Lorey K. Takahashi

    2014-03-01

    Full Text Available When prey animals detect the odor of a predator a constellation of fear-related autonomic, endocrine, and behavioral responses rapidly occur to facilitate survival. How olfactory sensory systems process predator odor and channel that information to specific brain circuits is a fundamental issue that is not clearly understood. However, research in the last 15 years has begun to identify some of the essential features of the sensory detection systems and brain structures that underlie predator odor fear. For instance, the main (MOS and accessory olfactory systems (AOS detect predator odors and different types of predator odors are sensed by specific receptors located in either the MOS or AOS. However, complex predator chemosignals may be processed by both the MOS and AOS, which complicate our understanding of the specific neural circuits connected directly and indirectly from the MOS and AOS to activate the physiological and behavioral components of unconditioned and conditioned fear. Studies indicate that brain structures including the dorsal periaqueductal gray, paraventricular nucleus of the hypothalamus, and the medial amygdala appear to be broadly involved in predator odor induced autonomic activity and hypothalamic-pituitary-adrenal stress hormone secretion. The medial amygdala also plays a key role in predator odor unconditioned fear behavior and retrieval of contextual fear memory associated with prior predator odor experiences. Other neural structures including the bed nucleus of the stria terminalis and the ventral hippocampus appear prominently involve in predator odor fear behavior. The basolateral amygdala, medial hypothalamic nuclei, and medial prefrontal cortex are also activated by some but not all predator odors. Future research that characterizes how distinct predator odors are uniquely processed in olfactory systems and neural circuits will provide significant insights into the differences of how diverse predator odors activate

  18. Hazardous Odor Recognition by CMAC Based Neural Networks

    OpenAIRE

    Bucak, İhsan Ömür; Karlık, Bekir

    2009-01-01

    Electronic noses are being developed as systems for the automated detection and classification of odors, vapors, and gases. Artificial neural networks (ANNs) have been used to analyze complex data and to recognize patterns, and have shown promising results in recognition of volatile compounds and odors in electronic nose applications. When an ANN is combined with a sensor array, the number of detectable chemicals is generally greater than the number of unique sensor types. The odor sensing sy...

  19. Olfactory systems and neural circuits that modulate predator odor fear.

    Science.gov (United States)

    Takahashi, Lorey K

    2014-01-01

    When prey animals detect the odor of a predator a constellation of fear-related autonomic, endocrine, and behavioral responses rapidly occur to facilitate survival. How olfactory sensory systems process predator odor and channel that information to specific brain circuits is a fundamental issue that is not clearly understood. However, research in the last 15 years has begun to identify some of the essential features of the sensory detection systems and brain structures that underlie predator odor fear. For instance, the main (MOS) and accessory olfactory systems (AOS) detect predator odors and different types of predator odors are sensed by specific receptors located in either the MOS or AOS. However, complex predator chemosignals may be processed by both the MOS and AOS, which complicate our understanding of the specific neural circuits connected directly and indirectly from the MOS and AOS to activate the physiological and behavioral components of unconditioned and conditioned fear. Studies indicate that brain structures including the dorsal periaqueductal gray (DPAG), paraventricular nucleus (PVN) of the hypothalamus, and the medial amygdala (MeA) appear to be broadly involved in predator odor induced autonomic activity and hypothalamic-pituitary-adrenal (HPA) stress hormone secretion. The MeA also plays a key role in predator odor unconditioned fear behavior and retrieval of contextual fear memory associated with prior predator odor experiences. Other neural structures including the bed nucleus of the stria terminalis and the ventral hippocampus (VHC) appear prominently involved in predator odor fear behavior. The basolateral amygdala (BLA), medial hypothalamic nuclei, and medial prefrontal cortex (mPFC) are also activated by some but not all predator odors. Future research that characterizes how distinct predator odors are uniquely processed in olfactory systems and neural circuits will provide significant insights into the differences of how diverse predator

  20. Avian influenza infection alters fecal odor in mallards.

    Directory of Open Access Journals (Sweden)

    Bruce A Kimball

    Full Text Available Changes in body odor are known to be a consequence of many diseases. Much of the published work on disease-related and body odor changes has involved parasites and certain cancers. Much less studied have been viral diseases, possibly due to an absence of good animal model systems. Here we studied possible alteration of fecal odors in animals infected with avian influenza viruses (AIV. In a behavioral study, inbred C57BL/6 mice were trained in a standard Y-maze to discriminate odors emanating from feces collected from mallard ducks (Anas platyrhynchos infected with low-pathogenic avian influenza virus compared to fecal odors from non-infected controls. Mice could discriminate odors from non-infected compared to infected individual ducks on the basis of fecal odors when feces from post-infection periods were paired with feces from pre-infection periods. Prompted by this indication of odor change, fecal samples were subjected to dynamic headspace and solvent extraction analyses employing gas chromatography/mass spectrometry to identify chemical markers indicative of AIV infection. Chemical analyses indicated that AIV infection was associated with a marked increase of acetoin (3-hydroxy-2-butanone in feces. These experiments demonstrate that information regarding viral infection exists via volatile metabolites present in feces. Further, they suggest that odor changes following virus infection could play a role in regulating behavior of conspecifics exposed to infected individuals.

  1. Impairment of odor hedonics in men with schizophrenia.

    Science.gov (United States)

    Moberg, Paul J; Arnold, Steven E; Doty, Richard L; Kohler, Christian; Kanes, Stephen; Seigel, Steven; Gur, Raquel E; Turetsky, Bruce I

    2003-10-01

    Olfactory deficits in patients with schizophrenia, including those of odor identification, detection threshold sensitivity, discrimination, and memory, have been well described. Deficits in emotional perception, processing, and experience have also been reported, with anhedonia being one of the core features. While anatomical connections testify to the relationship between olfaction and emotion, there has been little investigation of the hedonic properties of odors in schizophrenia. This study examined intensity and hedonic judgments in patients with schizophrenia to determine whether these functions were differentially impaired. Suprathreshold scaling of odor intensity and pleasantness was acquired by using the Suprathreshold Amyl Acetate Odor Intensity and Odor Pleasantness Rating Test given to 30 patients (15 men and 15 women) with a DSM-IV diagnosis of schizophrenia and 30 age- and sex-matched healthy comparison subjects. Despite virtually identical ratings of odor intensity, male patients were impaired in the assignment of odor pleasantness to amyl acetate. This gender-specific diagnostic group difference was not explained by variability in symptom severity or negative/positive symptoms. The impact of smoking status and general cognitive impairment on this deficit was also insignificant. Findings reveal a gender-specific disruption in the ability to attribute appropriate hedonic valence to odors in male patients with schizophrenia. This difficulty in identifying the hedonic valence of odors, despite intact intensity ratings, is consistent with clinical observations of anhedonia and points to a neural substrate that might contribute to the emotional disturbances seen in patients with schizophrenia.

  2. Present of offensive odor problems. Shuki mondaino genjo

    Energy Technology Data Exchange (ETDEWEB)

    Ishiguro, T.

    1991-06-01

    As of 1991, full 20 years have elapsed since the Offensive Odor Control Law was promulgated in June, 1971 at the opportunity of public offensive odor nuisance raised as an issue from fish meat bone feather blood mills. Past livestock breeding agriculture and industrial factory type claim started changing to urban life and livelihood type claim around FY 1980, and which also started increasing the production of odor-destroyer and deodorant, then added with microbiological deodorant, to form an industry of Yen 100 billions, as so called at present. 'Odor boom'is said to have started coming around 1985 when utilization started being positively tried of effect given by the odor. The rule to execute the present Offensive Odor Control Law is said to have its most important defect that the stipulated time be only five minutes to collect odor, which has its mere average of concentration felt. As problematic in dispersed data of measurement and detecting sensitivity, it is of a very difficult condition. Initiation has been also made of propagating propulsion of preventive measures from offensive odor, study of countermeasures against urban type offensive odor sources, etc. 2 refs., 5 figs., 2 tabs.

  3. Heteromeric Anopheline odorant receptors exhibit distinct channel properties.

    Directory of Open Access Journals (Sweden)

    Gregory M Pask

    Full Text Available Insect odorant receptors (ORs function as odorant-gated ion channels consisting of a conventional, odorant-binding OR and the Orco coreceptor. While Orco can function as a homomeric ion channel, the role(s of the conventional OR in heteromeric OR complexes has largely focused only on odorant recognition.To investigate other roles of odorant-binding ORs, we have employed patch clamp electrophysiology to investigate the properties of the channel pore of several OR complexes formed by a range of different odorant-specific Anopheles gambiae ORs (AgOrs each paired with AgOrco. These studies reveal significant differences in cation permeability and ruthenium red susceptibility among different AgOr complexes.With observable differences in channel function, the data support a model in which the odorant-binding OR also affects the channel pore. The variable effect contributed by the conventional OR on the conductive properties of odorant-gated sensory channels adds additional complexity to insect olfactory signaling, with differences in odor coding beginning with ORs on the periphery of the olfactory system.

  4. High-temperature stability of thermoelectric Ca3Co4O9 thin films

    DEFF Research Database (Denmark)

    Brinks, P.; Van Nong, Ngo; Pryds, Nini

    2015-01-01

    An enhanced thermal stability in thermoelectric Ca3Co4O9 thin films up to 550 °C in an oxygen rich environment was demonstrated by high-temperature electrical and X-ray diffraction measurements. In contrast to generally performed heating in helium gas, it is shown that an oxygen/helium mixture...

  5. Effects of high hydrostatic pressure or hydrophobic modification on thermal stability of xanthine oxidase.

    Science.gov (United States)

    Halalipour, Ali; Duff, Michael R; Howell, Elizabeth E; Reyes-De-Corcuera, José I

    2017-08-01

    The effect of high hydrostatic pressure (HHP) on the kinetics of thermal inactivation of xanthine oxidase (XOx) from bovine milk was studied. Inactivation of XOx followed pseudo-first-order kinetics at 0.1-300MPa and 55.0-70.0°C. High pressure up to at least 300MPa stabilized XOx at all the studied temperatures. The highest stabilization effect of HHP on XOx was at 200-300MPa at 55.0 and 58.6°C, and at 250-300MPa at 62.3-70.0°C. The stability of XOx increased 9.5 times at 300MPa and 70.0°C compared to atmospheric pressure at the same temperature. The activation energy of inactivation of XOx decreased with pressure and was 1.9 times less at 300MPa (97.0±8.2kJmol -1 ) than at 0.1MPa (181.7±12.1kJmol -1 ). High pressure decreased the dependence of the rate constant of inactivation to temperature effects compared to atmospheric pressure. The stabilizing effect of HHP on XOx was highest at 70.0°C where the activation volume of inactivation of XOx was 28.9±2.9cm 3 mol -1 . A second approach to try to increase XOx stability involved hydrophobic modification using aniline or benzoate. However, the thermal stability of XOx remained unaffected after 8-14 modifications of carboxyl side groups per XOx monomer with aniline, or 12-17 modifications of amino side groups per XOx monomer with benzoate. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Robust method for long-term energy and pointing stabilization of high energy, high average power solid state lasers.

    Science.gov (United States)

    Boge, Robert; Horáček, Jakub; Mazůrek, Petr; Naylon, Jack A; Green, Jonathan T; Hubka, Zbyněk; Šobr, Václav; Novák, Jakub; Batysta, František; Antipenkov, Roman; Bakule, Pavel; Rus, Bedřich

    2018-02-01

    A robust and simple method is presented for ensuring constant energy and pointing of a high average power solid state laser on a target. In addition to providing long-term stability, this scheme also eliminates any drifts in energy or pointing resulting from the initial warm-up after a cold start. This is achieved using two separate feedback loops: one loop stabilizes the pointing of the beam external to the amplifier cavity and the other locks the cavity mode to have optimum overlap with the pump spot on the active medium. The key idea of the cavity mode stabilization is to monitor the overlap of the cavity mode and the gain medium with a camera and control it with an actively controlled, intra-cavity mirror. While this method is demonstrated on a thin-disk regenerative amplifier, it can also be applied to a wide variety of solid state laser amplifiers.

  7. Robust method for long-term energy and pointing stabilization of high energy, high average power solid state lasers

    Science.gov (United States)

    Boge, Robert; Horáček, Jakub; Mazůrek, Petr; Naylon, Jack A.; Green, Jonathan T.; Hubka, Zbyněk; Šobr, Václav; Novák, Jakub; Batysta, František; Antipenkov, Roman; Bakule, Pavel; Rus, Bedřich

    2018-02-01

    A robust and simple method is presented for ensuring constant energy and pointing of a high average power solid state laser on a target. In addition to providing long-term stability, this scheme also eliminates any drifts in energy or pointing resulting from the initial warm-up after a cold start. This is achieved using two separate feedback loops: one loop stabilizes the pointing of the beam external to the amplifier cavity and the other locks the cavity mode to have optimum overlap with the pump spot on the active medium. The key idea of the cavity mode stabilization is to monitor the overlap of the cavity mode and the gain medium with a camera and control it with an actively controlled, intra-cavity mirror. While this method is demonstrated on a thin-disk regenerative amplifier, it can also be applied to a wide variety of solid state laser amplifiers.

  8. Ionization of water clusters by fast Highly Charged Ions: Stability, fragmentation, energetics and charge mobility

    International Nuclear Information System (INIS)

    Legendre, S; Maisonny, R; Capron, M; Bernigaud, V; Cassimi, A; Gervais, B; Grandin, J-P; Huber, B A; Manil, B; Rousseau, P; Tarisien, M; Adoui, L; Lopez-Tarifa, P; AlcamI, M; MartIn, F; Politis, M-F; Penhoat, M A Herve du; Vuilleumier, R; Gaigeot, M-P; Tavernelli, I

    2009-01-01

    We study dissociative ionization of water clusters by impact of fast Ni ions. Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) is used to obtain information about stability, energetics and charge mobility of the ionized clusters. An unusual stability of the (H 2 O) 4 H ''+ ion is observed, which could be the signature of the so called ''Eigen'' structure in gas phase water clusters. High charge mobility, responsible for the formation of protonated water clusters that dominate the mass spectrum, is evidenced. These results are supported by CPMD and TDDFT simulations, which also reveal the mechanisms of such mobility.

  9. Stability of high-beta tokamaks with respect to pellet injection

    International Nuclear Information System (INIS)

    Tetley, W.C.

    1983-01-01

    During the course of a long pulse or steady state operation, the fuel in a plasma becomes depleted. This necessitates the refueling of the reactor. Several methods have been proposed. In this thesis the use of pellet injection in a high toroidal beta tokamak is explored. Specifically the effect on stability is studied. Limits on the beta are found with respect to the size of the pellet injected. The device studied is the proposed upgrade of the Doublet III. The principal conclusion is that the stable beta is dependent on the shape of the current profile, and that by flattening the profile the plasma stability is increased

  10. Twin stability in highly nanotwinned Cu under compression, torsion and tension

    DEFF Research Database (Denmark)

    Hodge, A.M.; Furnish, T.A.; Shute, C.J.

    2012-01-01

    Twin stability under four distinct mechanical loading states has been investigated for highly nanotwinned Cu containing parallel nanotwins 40 nm thick. Observed deformation-induced microstructural changes under tension, compression, tension–tension fatigue and torsion are qualitatively compared...... in order to assess twin stability as a function of the loading direction and stress. It is observed that the twins are very stable although small microstructural changes vary with deformation mode. Shear bands, deformation-induced grain growth and detwinning are also discussed. © 2012 Acta Materialia Inc...

  11. Clay facial masks: physicochemical stability at different storage temperatures.

    Science.gov (United States)

    Zague, Vivian; de Almeida Silva, Diego; Baby, André Rolim; Kaneko, Telma Mary; Velasco, Maria Valéria Robles

    2007-01-01

    Clay facial masks--formulations that contain a high percentage of solids dispersed in a liquid vehicle--have become of special interest due to specific properties presented by clays, such as particle size, cooling index, high adsorption capacity, and plasticity. Although most of the physicochemical properties of clay dispersions have been studied, specific aspects concerning the physicochemical stability of clay mask products remain unclear. This work aimed at investigating the accelerated physicochemical stability of clay mask formulations stored at different temperatures. Formulations were subjected to centrifuge testing and to thermal treatment for 15 days, during which temperature was varied from -5.0 degrees to 45.0 degrees C. The apparent viscosity and visual aspect (homogeneity) of all formulations were affected by temperature variation, whereas color, odor, and pH value remained unaltered. These results, besides the estimation of physicochemical stability under aging, can be useful in determining the best storage conditions for clay-based formulations.

  12. Altered olfactory processing of stress-related body odors and artificial odors in patients with panic disorder.

    Directory of Open Access Journals (Sweden)

    Gloria-Beatrice Wintermann

    Full Text Available Patients with Panic Disorder (PD direct their attention towards potential threat, followed by panic attacks, and increased sweat production. Onés own anxiety sweat odor influences the attentional focus, and discrimination of threat or non-threat. Since olfactory projection areas overlap with neuronal areas of a panic-specific fear network, the present study investigated the neuronal processing of odors in general and of stress-related sweat odors in particular in patients with PD.A sample of 13 patients with PD with/ without agoraphobia and 13 age- and gender-matched healthy controls underwent an fMRI investigation during olfactory stimulation with their stress-related sweat odors (TSST, ergometry as well as artificial odors (peach, artificial sweat as non-fearful non-body odors.The two groups did not differ with respect to their olfactory identification ability. Independent of the kind of odor, the patients with PD showed activations in fronto-cortical areas in contrast to the healthy controls who showed activations in olfaction-related areas such as the amygdalae and the hippocampus. For artificial odors, the patients with PD showed a decreased neuronal activation of the thalamus, the posterior cingulate cortex and the anterior cingulate cortex. Under the presentation of sweat odor caused by ergometric exercise, the patients with PD showed an increased activation in the superior temporal gyrus, the supramarginal gyrus, and the cingulate cortex which was positively correlated with the severity of the psychopathology. For the sweat odor from the anxiety condition, the patients with PD showed an increased activation in the gyrus frontalis inferior, which was positively correlated with the severity of the psychopathology.The results suggest altered neuronal processing of olfactory stimuli in PD. Both artificial odors and stress-related body odors activate specific parts of a fear-network which is associated with an increased severity of the

  13. A novel high pressure, high temperature vessel used to conduct long-term stability measurements of silicon MEMS pressure transducers

    Science.gov (United States)

    Wisniewiski, David

    2014-03-01

    The need to quantify and to improve long-term stability of pressure transducers is a persistent requirement from the aerospace sector. Specifically, the incorporation of real-time pressure monitoring in aircraft landing gear, as exemplified in Tire Pressure Monitoring Systems (TPMS), has placed greater demand on the pressure transducer for improved performance and increased reliability which is manifested in low lifecycle cost and minimal maintenance downtime through fuel savings and increased life of the tire. Piezoresistive (PR) silicon MEMS pressure transducers are the primary choice as a transduction method for this measurement owing to their ability to be designed for the harsh environment seen in aircraft landing gear. However, these pressure transducers are only as valuable as the long-term stability they possess to ensure reliable, real-time monitoring over tens of years. The "heart" of the pressure transducer is the silicon MEMS element, and it is at this basic level where the long-term stability is established and needs to be quantified. A novel High Pressure, High Temperature (HPHT) vessel has been designed and constructed to facilitate this critical measurement of the silicon MEMS element directly through a process of mechanically "floating" the silicon MEMS element while being subjected to the extreme environments of pressure and temperature, simultaneously. Furthermore, the HPHT vessel is scalable to permit up to fifty specimens to be tested at one time to provide a statistically significant data population on which to draw reasonable conclusions on long-term stability. With the knowledge gained on the silicon MEMS element, higher level assembly to the pressure transducer envelope package can also be quantified as to the build-effects contribution to long-term stability in the same HPHT vessel due to its accommodating size. Accordingly, a HPHT vessel offering multiple levels of configurability and robustness in data measurement is presented, along

  14. Odor aversion and pathogen-removal efficiency in grooming behavior of the termite Coptotermes formosanus.

    Directory of Open Access Journals (Sweden)

    Aya Yanagawa

    Full Text Available The results of biocontrol with entomopathogens in termites have been discouraging because of the strong social hygiene behavior for removing pathogens from termite colonies. However, the mechanism of pathogen detection is still unclear. For the successful application of biopesticides to termites in nature, it would be beneficial to identify substances that could disrupt the termite's ability to perceive pathogens. We hypothesized that termites can perceive pathogens and this ability plays an important role in effective hygiene behavior. In this study, pathogen-detection in the subterranean termite Coptotermes formosanus was investigated. We performed quantitative assays on conidia removal by grooming behavior using epifluoresence microscopy and Y-maze tests to examine the perception of fungal odor by termites. Three species each of high- and low-virulence entomopathogenic fungi were used in each test. The results demonstrated that termites removed conidia more effectively from a nestmate's cuticle if its odor elicited stronger aversion. Highly virulent pathogens showed higher attachment rates to termite surfaces and their odors were more strongly avoided than those of low-virulence isolates in the same species. Moreover, termites appeared to groom each other more persistently when they had more conidia on their bodies. In brief, insect perception of pathogen-related odor seems to play a role in the mechanism of their hygiene behavior.

  15. Improving the Output Power Stability of a High Concentration Photovoltaic System with Supercapacitors: A Preliminary Evaluation

    Directory of Open Access Journals (Sweden)

    Yu-Pei Huang

    2015-01-01

    Full Text Available The output power of a high concentration photovoltaic (HCPV system is very sensitive to fluctuating tracking errors and weather patterns. To help compensate this shortcoming, supercapacitors have been successfully incorporated into photovoltaic systems to improve their output power stability. This study examined the output power stability improvement of an HCPV module with a supercapacitor integrated into its circuit. Furthermore, the equivalent model of the experimental circuit is presented and analyzed. Experimental results suggest that integrating a supercapacitor into an HCPV module could improve its output power stability and further extend its acceptance angle. This paper provides preliminary data of the improvement and its evaluation method, which could be utilized for further improvements to an HCPV system.

  16. High-throughput Procedure for the Peat Soil Reference Sample Stabilization Using Microwave Radiation

    Directory of Open Access Journals (Sweden)

    Keiti Oliveira Alessio

    2017-12-01

    Full Text Available Reference materials used in quality control laboratories need to maintain homogeneity and stability that can be affected by temperature, humidity and microbial activity. This research aimed to investigate a rapid, cheap and high-throughput procedure, using microwave radiation for the inhibition of microbial growth in peat reference sample, in order to increase its stability. Different exposure times (60, 120 and 180 seconds of the material to radiation were evaluated, and the microbiological tests were conducted to assess the percentage reduction in CFUs for fungi and bacteria. The results showed 100% and >90% of reduction in growth for bacterial and fungi, respectively, over 90 days of monitoring the material, using 120 to 180 seconds of microwave radiation exposure times. The results demonstrate that this method is economical and efficient at stabilizing peat reference materials. DOI: http://dx.doi.org/10.17807/orbital.v9i5.942

  17. Assessing the Impact of Charge Variants on Stability and Viscosity of a High Concentration Antibody Formulation.

    Science.gov (United States)

    Sule, Shantanu V; Fernandez, Jason E; Mecozzi, Vincent J; Kravets, Yana; Yang, William C; Feng, Pamela; Liu, Suli; Zang, Li; Capili, Allan D; Estey, Tia B; Gupta, Kapil

    2017-12-01

    Characterizing molecular charge variants or isoforms is essential for understanding safety, potency, and bioavailability of antibody therapeutics. However, there is little information on how they influence stability and viscosity-properties governing immunogenicity and delivery. To bridge this gap, we studied antibody stability as a function of charge variant content generated via bioreactor process. We were able to systematically vary acidic variant levels as a function of bioreactor harvest time. Importantly, we do not observe any impact on aggregation behavior of a formulated antibody at high protein concentration as a function of acidic variant level. Furthermore, we confirm that acidic variants enriched using fractionation do not influence viscosity, colloidal or conformational stability. Interestingly, variants with the most acidic isoelectric points contribute disproportionately to formulation color. We discuss our findings in context of antibody manufacturing processes that may yield increased charge variant content. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  18. Structure, electrical characteristics, and high-temperature stability of aerosol jet printed silver nanoparticle films

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Md Taibur; McCloy, John; Panat, Rahul, E-mail: rahul.panat@wsu.edu, E-mail: rvchintalapalle@utep.edu [School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99163 (United States); Ramana, C. V., E-mail: rahul.panat@wsu.edu, E-mail: rvchintalapalle@utep.edu [Department of Mechanical Engineering, University of Texas at El Paso, El Paso, Texas 79968 (United States)

    2016-08-21

    Printed electronics has emerged as a versatile eco-friendly fabrication technique to create sintered nanoparticle (NP) films on arbitrary surfaces with an excellent control over the film microstructure. While applicability of such films for high-temperature applications is not explored previously, herein we report the high-temperature electrical stability of silver (Ag) metal NP films fabricated using an Aerosol Jet based printing technique and demonstrate that this behavior is dictated by changes in the film microstructure. In-situ high temperature (24–500 °C) impedance spectroscopy measurements show that the real part of the impedance increases with increasing temperature up to 150 °C, at which point a decreasing trend prevails until 300 °C, followed again by an increase in impedance. The electrical behavior is correlated with the in-situ grain growth of the Ag NP films, as observed afterwards by scanning electron microscopy and X-ray diffraction (XRD), and could be tailored by controlling the initial microstructure through sintering conditions. Using combined diffraction and spectroscopic analytical methods, it is demonstrated the Aerosol Jet printed Ag NP films exhibit enhanced thermal stability and oxidation resistance. In addition to establishing the conditions for stability of Ag NP films, the results provide a fundamental understanding of the effect of grain growth and reduction in grain boundary area on the electrical stability of sintered NP films.

  19. Thermal and shape stability of high-index-faceted rhodium nanoparticles: a molecular dynamics investigation.

    Science.gov (United States)

    Zeng, Xiang-Ming; Huang, Rao; Wen, Yu-Hua; Sun, Shi-Gang

    2015-02-28

    Nanosized noble metallic particles enclosed by high-index facets exhibit superior catalytic activity because of their high density of low-coordinated step atoms at the surface, and thus have attracted growing interest over the past decade. In this article, we employed molecular dynamics simulations to investigate the thermodynamic evolution of tetrahexahedral Rh nanoparticles respectively covered by {210}, {310}, and {830} facets during the heating process. Our results reveal that the {210} faceted nanoparticle exhibits better thermal and shape stability than the {310} and {830} faceted ones. Meanwhile, because the {830} facet consists of {210} and {310} subfacets, the stability of the {830} faceted Rh nanoparticle is dominated by the {310} subfacet, which possesses a relatively poor stability. Furthermore, the shape transformation of these nanoparticles occurs much earlier than their melting. Further analyses indicate that surface atoms with higher coordination numbers display lower surface diffusivity, and are thus more helpful for stabilizing the particle shape. This study offers an atomistic understanding of the thermodynamic behaviors of high-index-faceted Rh nanoparticles.

  20. Stability constant determinations for technetium (IV) complexation with selected amino carboxylate ligands in high nitrate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Omoto, Trevor; Wall, Nathalie A. [Washington State Univ., Pullman, WA (United States). Dept. of Chemistry

    2017-10-01

    The stability constants for Tc(IV) complexation with the ligands IDA, NTA, HEDTA, and DTPA were determined in varied nitrate concentrations using liquid-liquid extraction methods. The determined log β{sub 101} stability constants at 0.5 M NaNO{sub 3} were found to be 9.2±0.3, 10.3±0.3, and 15.3±0.3 for IDA, NTA, and HEDTA, respectively. The log β{sub 111} stability constant for DTPA was determined to be 22.0±0.6. These determined stability constants show a slight decrease in magnitude as a function of increasing NaNO{sub 3} concentration. These stability constants were used to model the total dissolution of Tc(IV) in acidic aqueous solutions in the presence of each ligand. The results of these predictive models indicate that amino carboxylic ligands have a high potential for increasing the aqueous dissolution of Tc(IV); at pH 2.3, 0.01 M ligand yield dissolved Tc(IV) concentrations of 1.42.10{sup -5} M, 1.33.10{sup -5} M, 6.07.10{sup -6} M, 9.65.10{sup -7} M, for DTPA, HEDTA, NTA, and IDA, respectively.

  1. Transport and stability analyses supporting disruption prediction in high beta KSTAR plasmas

    Science.gov (United States)

    Ahn, J.-H.; Sabbagh, S. A.; Park, Y. S.; Berkery, J. W.; Jiang, Y.; Riquezes, J.; Lee, H. H.; Terzolo, L.; Scott, S. D.; Wang, Z.; Glasser, A. H.

    2017-10-01

    KSTAR plasmas have reached high stability parameters in dedicated experiments, with normalized beta βN exceeding 4.3 at relatively low plasma internal inductance li (βN/li>6). Transport and stability analyses have begun on these plasmas to best understand a disruption-free path toward the design target of βN = 5 while aiming to maximize the non-inductive fraction of these plasmas. Initial analysis using the TRANSP code indicates that the non-inductive current fraction in these plasmas has exceeded 50 percent. The advent of KSTAR kinetic equilibrium reconstructions now allows more accurate computation of the MHD stability of these plasmas. Attention is placed on code validation of mode stability using the PEST-3 and resistive DCON codes. Initial evaluation of these analyses for disruption prediction is made using the disruption event characterization and forecasting (DECAF) code. The present global mode kinetic stability model in DECAF developed for low aspect ratio plasmas is evaluated to determine modifications required for successful disruption prediction of KSTAR plasmas. Work supported by U.S. DoE under contract DE-SC0016614.

  2. The link between odors and illness : how health cognitions affect odor perception

    NARCIS (Netherlands)

    Bulsing, P.J.

    2009-01-01

    Some people report health effects after exposure to relatively low levels of odorous chemicals, levels which are often well tolerated by the majority of the population. The research in this thesis was aimed at investigating the role of cognitive influences in this phenomenon. Could it be possible

  3. Change of odor characteristics of fuel gas

    International Nuclear Information System (INIS)

    Stoll, J.-M.

    2006-01-01

    For safety reasons, very small amounts of tetrahydrothiophene (THT) are added to the natural gas distributed through pipelines in Switzerland. The aim is to give the naturally odorless gas a strong smell of mineral coal gas so that inhabitants will be warned of gas leaks. However, experts suspected that this typical smell would be lost when natural gas flows through soils that are polluted with mineral oils and that the nauseous odor would be replaced by a pleasant one. This suspicion was confirmed by flow tests carried out with different types of soil (organic substances' share: 6.6 - 11.4%; various pollutants). (author)

  4. Light-weight analyzer for odor recognition

    Energy Technology Data Exchange (ETDEWEB)

    Vass, Arpad A; Wise, Marcus B

    2014-05-20

    The invention provides a light weight analyzer, e.g., detector, capable of locating clandestine graves. The detector utilizes the very specific and unique chemicals identified in the database of human decompositional odor. This detector, based on specific chemical compounds found relevant to human decomposition, is the next step forward in clandestine grave detection and will take the guess-work out of current methods using canines and ground-penetrating radar, which have historically been unreliable. The detector is self contained, portable and built for field use. Both visual and auditory cues are provided to the operator.

  5. Linear stability theory as an early warning sign for transitions in high dimensional complex systems

    International Nuclear Information System (INIS)

    We analyse in detail a new approach to the monitoring and forecasting of the onset of transitions in high dimensional complex systems by application to the Tangled Nature model of evolutionary ecology and high dimensional replicator systems with a stochastic element. A high dimensional stability matrix is derived in the mean field approximation to the stochastic dynamics. This allows us to determine the stability spectrum about the observed quasi-stable configurations. From overlap of the instantaneous configuration vector of the full stochastic system with the eigenvectors of the unstable directions of the deterministic mean field approximation, we are able to construct a good early-warning indicator of the transitions occurring intermittently. (paper)

  6. Development of a High Temperature Heater using an Yttria Stabilized Zirconia Cored Brick Matrix

    Science.gov (United States)

    Smith, K. W.; Decoursin, D. G.

    1971-01-01

    The Ames pilot heater is a ceramic regenerative heater that provides high temperature air for aerodynamic and combustion experiments. The development of this heater to provide a heat storage bed with temperature capability of about 4600 R is described. A bed was designed and installed having cored brick elements of yttria-stabilized zirconia. The bed dimensions were 14 inches in diameter by 10 feet high. The thermal stress limitations of the bed were studied and maximum air flow rates based upon these limits were established. A combustion reheat system was designed and installed to provide the necessary control over the bed temperature distribution. The revised heater system was successfully operated at a maximum bed temperature of 4600 R. The successful operation demonstrated that yttria-stabilized zirconia cored brick can satisfy the high temperature-long duration requirement for storage heater applications.

  7. Stabilized super-thermite colloids: A new generation of advanced highly energetic materials

    Science.gov (United States)

    Elbasuney, Sherif; Gaber Zaky, M.; Radwan, Mostafa; Mostafa, Sherif F.

    2017-10-01

    One of the great impetus of nanotechnology on energetic materials is the achievement of nanothermites (metal-oxide/metal) which are characterized by massive heat output. Yet, full exploitation of super-thermites in highly energetic systems has not been achieved. This manuscript reports on the sustainable fabrication of colloidal Fe2O3 and CuO nanoparticles for thermite applications. TEM micrographs demonstrated mono-dispersed Fe2O3 and CuO with an average particle size of 3 and 15 nm respectively. XRD diffractograms demonstrated highly crystalline materials. SEM micrographs demonstrated a great tendency of the developed oxides to aggregate over drying process. The effective integration and dispersion of mono-dispersed colloidal thermite particles into energetic systems are vital for enhanced performance. Aluminum is of interest as highly energetic metal fuel. In this paper, synthesized Fe2O3 and CuO nanoparticles were re-dispersed in isopropyl alcohol (IPA) with aluminum nanoparticles using ultrasonic prope homogenizer. The colloidal thermite peraticles can be intgegrated into highly energetic system for subsequent nanocomposite development. Thanks to stabilization of colloidal CuO nanoparticles in IPA which could offer intimate mixing between oxidizer and metal fuel. The stabilization mechanism of CuO in IPA was correlated to steric stabilization with solvent molecules. This approach eliminated nanoparticle drying and the re-dispersion of dry aggregates into energetic materials. This manuscript shaded the light on the real development of colloidal thermite mixtures and their integration into highly energetic systems.

  8. ORBITAL STABILITY OF MULTI-PLANET SYSTEMS: BEHAVIOR AT HIGH MASSES

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, Sarah J. [Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Kratter, Kaitlin M., E-mail: morrison@lpl.arizona.edu, E-mail: kkratter@email.arizona.edu [Steward Observatory, The University of Arizona, Tucson, AZ 85721 (United States)

    2016-06-01

    In the coming years, high-contrast imaging surveys are expected to reveal the characteristics of the population of wide-orbit, massive, exoplanets. To date, a handful of wide planetary mass companions are known, but only one such multi-planet system has been discovered: HR 8799. For low mass planetary systems, multi-planet interactions play an important role in setting system architecture. In this paper, we explore the stability of these high mass, multi-planet systems. While empirical relationships exist that predict how system stability scales with planet spacing at low masses, we show that extrapolating to super-Jupiter masses can lead to up to an order of magnitude overestimate of stability for massive, tightly packed systems. We show that at both low and high planet masses, overlapping mean-motion resonances trigger chaotic orbital evolution, which leads to system instability. We attribute some of the difference in behavior as a function of mass to the increasing importance of second order resonances at high planet–star mass ratios. We use our tailored high mass planet results to estimate the maximum number of planets that might reside in double component debris disk systems, whose gaps may indicate the presence of massive bodies.

  9. Thermal Stability-Enhanced and High-Efficiency Planar Perovskite Solar Cells with Interface Passivation.

    Science.gov (United States)

    Zhang, Weihai; Xiong, Juan; Jiang, Li; Wang, Jianying; Mei, Tao; Wang, Xianbao; Gu, Haoshuang; Daoud, Walid A; Li, Jinhua

    2017-11-08

    As the electron transport layer (ETL) of perovskite solar cells, oxide semiconductor zinc oxide (ZnO) has been attracting great attention due to its relatively high mobility, optical transparency, low-temperature fabrication, and good environment stability. However, the nature of ZnO will react with the patron on methylamine, which would deteriorate the performance of cells. Although many methods, including high-temperature annealing, doping, and surface modification, have been studied to improve the efficiency and stability of perovskite solar cells with ZnO ETL, devices remain relatively low in efficiency and stability. Herein, we adopted a novel multistep annealing method to deposit a porous PbI 2 film and improved the quality and uniformity of perovskite films. The cells with ZnO ETL were fabricated at the temperature of perovskite film. Interestingly, the PCE of PCBM-passivated cells could reach nearly 19.1%. To our best knowledge, this is the highest PCE value of ZnO-based perovskite solar cells until now. More importantly, PCBM modification could effectively suppress the decomposition of MAPbI 3 and improve the thermal stability of cells. Therefore, the ZnO is a promising candidate of electron transport material for perovskite solar cells in future applications.

  10. Improving the oxidative stability of a high redox potential fungal peroxidase by rational design.

    Directory of Open Access Journals (Sweden)

    Verónica Sáez-Jiménez

    Full Text Available Ligninolytic peroxidases are enzymes of biotechnological interest due to their ability to oxidize high redox potential aromatic compounds, including the recalcitrant lignin polymer. However, different obstacles prevent their use in industrial and environmental applications, including low stability towards their natural oxidizing-substrate H2O2. In this work, versatile peroxidase was taken as a model ligninolytic peroxidase, its oxidative inactivation by H2O2 was studied and different strategies were evaluated with the aim of improving H2O2 stability. Oxidation of the methionine residues was produced during enzyme inactivation by H2O2 excess. Substitution of these residues, located near the heme cofactor and the catalytic tryptophan, rendered a variant with a 7.8-fold decreased oxidative inactivation rate. A second strategy consisted in mutating two residues (Thr45 and Ile103 near the catalytic distal histidine with the aim of modifying the reactivity of the enzyme with H2O2. The T45A/I103T variant showed a 2.9-fold slower reaction rate with H2O2 and 2.8-fold enhanced oxidative stability. Finally, both strategies were combined in the T45A/I103T/M152F/M262F/M265L variant, whose stability in the presence of H2O2 was improved 11.7-fold. This variant showed an increased half-life, over 30 min compared with 3.4 min of the native enzyme, under an excess of 2000 equivalents of H2O2. Interestingly, the stability improvement achieved was related with slower formation, subsequent stabilization and slower bleaching of the enzyme Compound III, a peroxidase intermediate that is not part of the catalytic cycle and leads to the inactivation of the enzyme.

  11. Psychological and physiological responses to odor-evoked autobiographic memory.

    Science.gov (United States)

    Matsunaga, Masahiro; Isowa, Tokiko; Yamakawa, Kaori; Kawanishi, Yoko; Tsuboi, Hirohito; Kaneko, Hiroshi; Sadato, Norihiro; Oshida, Akiko; Katayama, Atsushi; Kashiwagi, Mitsuyoshi; Ohira, Hideki

    2011-01-01

    The "Proust phenomenon" occurs when a certain smell evokes a specific memory. Recent studies have demonstrated that odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli because of the direct neural communication between the olfactory system and the amygdala. The amygdala is known to regulate various physiological activities including the endocrine and immune systems; therefore, odor-evoked autobiographic memory may trigger various psychological and physiological responses; however, the responses elicited by this memory remains obscure. In this study, we aimed to investigate the psychological and physiological responses accompanying odor-evoked autobiographic memory. We recruited healthy male and female volunteers and investigated changes in their mood states and autonomic nervous, endocrine, and immune activities when autobiographic memory was evoked in the participants by asking them to smell an odor(s) that was nostalgic to them. The autobiographic memories associated with positive emotion resulted in increased positive mood states, such as comfort and happiness, and decreased negative mood states, such as anxiety. Furthermore, heart rate was decreased, skin-conductance level was increased, and peripheral interleukin-2 level was decreased after smelling the nostalgic odor. These psychological and physiological responses were significantly correlated. The present study suggests that odor-evoked autobiographic memory along with a positive feeling induce various physiological responses, including the autonomic nervous and immune activities. To the best of our knowledge, the present study is the first to observe an interaction between odor-evoked autobiographic memories and immune function.

  12. Odor from pig production: its relation to diet

    NARCIS (Netherlands)

    Dinh Phung, Le P.D.

    2006-01-01

    Keywords.Odor, Pigs, Diet, Manure, Protein, Amino Acids, Fermentable carbohydratesOdor from pig manure creates a serious nuisance for people

  13. 49 CFR 192.625 - Odorization of gas.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Odorization of gas. 192.625 Section 192.625... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Operations § 192.625 Odorization of gas. (a) A...

  14. Odor control in swine buildings: recycle flush vs. automated scraper

    Science.gov (United States)

    A research project was conducted to compare odor concentrations in exhaust of traditional flush barns and barns equipped with automated scrapers. The study was conducted at commercial tunnel-ventilated swine barns in northwest Missouri. Odor samples were collected from the barn exhaust in polyvinyl ...

  15. 77 FR 22381 - Odorant Fade in Railroad Tank Cars

    Science.gov (United States)

    2012-04-13

    ... as olfactory fatigue, sinus congestion, allergies, head colds, smoking, or the recent use of alcohol... of the odorant from the calibration scale that is marked on the tube. The gas chromatography test... DEPARTMENT OF TRANSPORTATION Federal Railroad Administration [Safety Advisory 2012-01] Odorant...

  16. Effect of thermal and high pressure processing on stability of betalain extracted from red beet stalks.

    Science.gov (United States)

    Dos Santos, Cláudia Destro; Ismail, Marliya; Cassini, Aline Schilling; Marczak, Ligia Damasceno Ferreira; Tessaro, Isabel Cristina; Farid, Mohammed

    2018-02-01

    Red beet stalks are a potential source of betalain, but their pigments are not widely used because of their instability. In the present work, the applicability of high pressure processing (HPP) and high temperature short time (HTST) thermal treatment was investigated to improve betalain stability in extracts with low and high concentrations. The HPP was applied at 6000 bar for 10, 20 and 30 min and HTST treatment was applied at 75.7 °C for 80 s, 81.1 °C for 100 s and 85.7 °C for 120 s, HPP treatment did not show any improvement in the betalain stability. In turn, the degradation rate of the control and the HTST thermal treatment at 85.7 °C for 120 s of the sample with high initial betalain concentration were 1.2 and 0.4 mg of betanin/100 ml of extract per day respectively. Among the treatments studied, HTST was considered the most suitable to maintain betalain stability from red beet stalks.

  17. Addition of hydrogen peroxide for the simultaneous control of bromate and odor during advanced drinking water treatment using ozone.

    Science.gov (United States)

    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. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  18. Nuisance Odors: Is there a Concern - 12340

    Energy Technology Data Exchange (ETDEWEB)

    Brounstein, Robert A. [TerranearPMC, Los Alamos New Mexico 87544 (United States)

    2012-07-01

    Nuisance odors are generally thought of as just being annoying or unpleasant and not causing any physiological harm to our internal organs or other biologic systems. Yet during an excavation of buried animal remains, field workers experienced a multitude of symptoms that are associated with exposures to toxic materials. An examination of the decomposition process revealed that there is a potential off-gassing of a number of common, yet harmful chemicals including ammonia, mercaptans, hydrogen sulfide, butyric acid and phenol. In addition, other compounds, that have limited information such as established health data and occupational exposure limits, were also potential contaminants-of-concern. While a variety of monitoring and sampling techniques were used to assess worker exposures, all results indicated non-detectable airborne concentrations. Nevertheless, workers were experiencing such symptoms as nausea and headaches. As such, protective measures were necessary for field personnel to continue work while having confidence that the project was instituting sincere steps to ensure their health and safety. Researching the possible reasons for the causes of workers exhibiting adverse health effects from nuisance odors revealed that such exposures initiate electrochemical pathways, starting from the olfactory bulb to the brain, followed by a transfer of information to such biologic systems as the hypothalamus and pituitary gland. These systems, in turn, secrete hormones that cause a number of involuntary reactions; many of which are observed as typical adverse health effects, when in fact, they are merely reactions caused by the brain's memory; most likely created from previous experiences to unpleasant odors. The concern then focuses of how the Occupational Safety and Health community shall respond to such workplace exposures. Future work in this area may need to focus on the viability of current occupational exposure limits and the possibility of revising these

  19. The odorant receptor repertoire of teleost fish

    Directory of Open Access Journals (Sweden)

    Alioto Tyler S

    2005-12-01

    Full Text Available Abstract Background Vertebrate odorant receptors comprise three types of G protein-coupled receptors: the OR, V1R and V2R receptors. The OR superfamily contains over 1,000 genes in some mammalian species, representing the largest gene superfamily in the mammalian genome. Results To facilitate an informed analysis of OR gene phylogeny, we identified the complete set of 143 OR genes in the zebrafish genome, as well as the OR repertoires in two pufferfish species, fugu (44 genes and tetraodon (42 genes. Although the genomes analyzed here contain fewer genes than in mammalian species, the teleost OR genes can be grouped into a larger number of major clades, representing greater overall OR diversity in the fish. Conclusion Based on the phylogeny of fish and mammalian repertoires, we propose a model for OR gene evolution in which different ancestral OR genes or gene families were selectively lost or expanded in different vertebrate lineages. In addition, our calculations of the ratios of non-synonymous to synonymous codon substitutions among more recently expanding OR subgroups in zebrafish implicate residues that may be involved in odorant binding.

  20. The unexpected stability of multiwall nanotubes under high pressure and shear deformation

    Energy Technology Data Exchange (ETDEWEB)

    Pashkin, E. Y.; Pankov, A. M.; Kulnitskiy, B. A.; Mordkovich, V. Z. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Moscow Institute of Physics and Technology, 9 Institutsky Lane, Dolgoprudny 141700 (Russian Federation); Perezhogin, I. A. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Lomonosov Moscow State University, Leninskie Gory, Moscow 119991 (Russian Federation); Karaeva, A. R. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Popov, M. Y.; Sorokin, P. B.; Blank, V. D. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Moscow Institute of Physics and Technology, 9 Institutsky Lane, Dolgoprudny 141700 (Russian Federation); National University of Science and Technology MISiS, 4 Leninskiy Prospekt, Moscow 119049 (Russian Federation)

    2016-08-22

    The behavior of multiwall carbon nanotubes under a high pressure (up to 55 GPa) combined with shear deformation was studied by experimental and theoretical methods. The unexpectedly high stability of the nanotubes' structure under high stresses was observed. After the pressure was released, we observed that the nanotubes had restored their shapes. Atomistic simulations show that the hydrostatic and shear stresses affect the nanotubes' structure in a different way. It was found that the shear stress load in the multiwall nanotubes' outer walls can induce their connection and formation of an amorphized sp{sup 3}-hybridized region but internal core keeps the tubular structure.

  1. Extended Stability of HPGe Spectrometer with Environmental Control at the High Flux Isotope Reactor

    Science.gov (United States)

    Heim, Jordan; Nistor, Jonathan; Koltick, David

    A High Purity Germanium (HPGe) spectrometer has been designed and constructed for making precision measurements over extended time periods at the High Flux Isotope Reactor (HFIR) located at Oak Ridge National Lab (ORNL). Toward the effort of achieving long-term system stability and high spectral resolution, local environment control is utilized as part of the system design. Further, the remote operation of the spectrometer is aided by live-streaming system conditions and automatic out-of-range alert messaging. System performance over the 7-month Phase I period is presented.

  2. Precipitation Effect on Mechanical Properties and Phase Stability of High Manganese Steel

    Science.gov (United States)

    Bae, Cheoljun; Kim, Rosa; Lee, Un-Hae; Kim, Jongryoul

    2017-09-01

    High manganese (Mn) steels are attractive for automotive applications due to their excellent tensile strength and superior elongation. However, the relatively low yield strength of Mn steels compared to other advanced high-strength steels is a critical problem limiting their use in structural parts. In order to increase the yield strength, the precipitation hardening effect of Mn steels was investigated by the addition of carbide-forming elements. Changes in the austenite phase stability were also evaluated in terms of stacking fault energy (SFE). As a result, fine V(C,N) precipitates were found to increase the yield strength effectively but to lower the SFE by the consumption of matrix carbons. For achieving precipitation hardening without sacrificing austenite stability, the soluble carbon content was discussed.

  3. Shot-to-shot intensity and wavefront stability of high-harmonic generation.

    Science.gov (United States)

    Künzel, S; Williams, G O; Boutu, W; Galtier, E; Barbrel, B; Lee, H J; Nagler, B; Zastrau, U; Dovillaire, G; Lee, R W; Merdji, H; Zeitoun, Ph; Fajardo, M

    2015-05-20

    We report on the shot-to-shot stability of intensity and spatial phase of high-harmonic generation (HHG). The intensity stability is measured for each high-harmonic (HH) order with a spectrometer. Additionally, the spatial phase is measured with an XUV wavefront sensor for a single HH order measured in a single shot, which according to our knowledge was not reported before with a Hartmann wavefront sensor. Furthermore, we compare the single-shot measurement of the spatial phase with time-integrated measurements and we show that the XUV wavefront sensor is a useful tool to simultaneously optimize the spatial phase and intensity of HHG within the available HHG parameter range used in this study.

  4. Dynamic Rocker-Bogie: A Stability Enhancement for High-Speed Traversal

    Directory of Open Access Journals (Sweden)

    Hong-an Yang

    2014-05-01

    Full Text Available The rocker-bogie suspension mechanism it’s currently NASA’s favored design for wheeled mobile robots, mainly because it has robust capabilities to deal with obstacles and because it uniformly distributes the payload over its 6 wheels at all times. Even though it has many advantages when dealing with obstacles, there is one major shortcoming which is its low average speed of operation, making the rocker-bogie system not suitable for situations where high-speed traversal over hard-flat surfaces is needed to cover large areas in short periods of time, mainly due to stability problems. This paper proposes to increase the stability of the rocker-bogie system by expanding its support polygon, making it more stable and adaptable while moving at high speed, but keeping its original robustness against obstacles: One rocker-bogie system, two modes of operation.

  5. Core-shell structured titanium-nitrogen alloys with high strength, high thermal stability and good plasticity.

    Science.gov (United States)

    Zhang, Y S; Zhao, Y H; Zhang, W; Lu, J W; Hu, J J; Huo, W T; Zhang, P X

    2017-01-06

    Multifunctional materials with more than two good properties are widely required in modern industries. However, some properties are often trade-off with each other by single microstructural designation. For example, nanostructured materials have high strength, but low ductility and thermal stability. Here by means of spark plasma sintering (SPS) of nitrided Ti particles, we synthesized bulk core-shell structured Ti alloys with isolated soft coarse-grained Ti cores and hard Ti-N solid solution shells. The core-shell Ti alloys exhibit a high yield strength (~1.4 GPa) comparable to that of nanostructured states and high thermal stability (over 1100 °C, 0.71 of melting temperature), contributed by the hard Ti-N shells, as well as a good plasticity (fracture plasticity of 12%) due to the soft Ti cores. Our results demonstrate that this core-shell structure offers a design pathway towards an advanced material with enhancing strength-plasticity-thermal stability synergy.

  6. Hypochlorite solution for root canal irrigation that lacks a chlorinated odor.

    Science.gov (United States)

    Vajrabhaya, La-Ongthong; Sangalungkarn, Vanida; Srisatjaluk, Ratchapin; Korsuwannawong, Suwanna; Phruksaniyom, Chareerut

    2017-01-01

    This is an in vitro study to develop a formulation of a hypochlorite solution for root canal irrigation that lacks a chlorinated odor. The antibacterial effect, tissue dissolution efficacy, and the cytotoxicity of the solution were assessed in cell culture and were compared with those of commercial sodium hypochlorite (NaOCl) solutions. Trichloroisocyanuric acid (TCA) was used as the source of hypochlorite ions in solution. All required properties of the NaOCl irrigant were evaluated and compared with those of original 2.5% NaOCl solutions currently in use. Our results revealed that a TCA 3.5% + 1/6 Buffer-1 solution passed the short-term stability test. Moreover, no odor of chlorine gas was detected by three independent observers. The hypochlorite ion content and pH were stable over an incubation period of 4 weeks. The new solution did not differ from commercial products in terms of the dissolution property on bovine pulpal tissue ( P > 0.05). Moreover, the antibacterial effect of this solution on Enterococcus faecalis did not differ from that of the commercial products ( P > 0.05). In addition, our biocompatibility analysis demonstrated no difference among the tested solutions ( P > 0.05). According to the results of all properties tested, TCA 3.5% + 1/6 Buffer-1 could be considered an option for NaOCl irrigation with the benefit of no detectable chlorine odor.

  7. Improvement of enalapril maleate chemical stability by high shear melting granulation.

    Science.gov (United States)

    de Oliveira, Ana Paula Montandon; Cunha, Talita Amorim; Serpa, Raphael Caixeta; Taveira, Stephânia Fleury; Lima, Eliana Martins; Almeida Diniz, Danielle Guimarães; de Freitas, Luis Alexandre Pedro; Marreto, Ricardo Neves

    2014-09-18

    Abstract Enalapril maleate is a widely used drug, which is chemically unstable when mixed with excipients resulting in enalaprilat and diketopiperazine as the main degradation products. The preparation of enalapril sodium salt has been used to improve drug stability in solid dosage forms; however, product rejection is observed when the chemical reaction for obtaining the sodium salt is not completely finished before packaging. In this study, granules were prepared by melting granulation using stearic acid or glyceryl monostearate, with a view to developing more stable enalapril maleate solid dosage forms. The granules were prepared in a laboratory-scale high shear mixer and compressed in a rotary machine. Size distribution, flow properties, in vitro drug release and enalapril maleate chemical stability were evaluated and compared with data obtained from tablets prepared without hydrophobic binders. All formulations showed good physical properties and immediate drug release. The greatest improvement in the enalapril maleate stability was observed in formulations containing stearic acid. This study showed that hot melting granulation could be successfully used to prepare enalapril maleate granules which could substitute the in situ formation of enalapril sodium salt, since they provided better enalapril stability in solid dosage forms.

  8. Serial position effects in recognition memory for odors: a reexamination.

    Science.gov (United States)

    Miles, Christopher; Hodder, Kathryn

    2005-10-01

    Seven experiments examined recognition memory for sequentially presented odors. Following Reed (2000), participants were presented with a sequence of odors and then required to identify an odor from the sequence in a test probe comprising 2 odors. The pattern of results obtained by Reed (2000, although statistically marginal) demonstrated enhanced recognition for odors presented at the start (primacy) and end (recency) of the sequence: a result that we failed to replicate in any of the experiments reported here. Experiments 1 and 3 were designed to replicate Reed (2000), employing five-item and seven-item sequences, respectively, and each demonstrated significant recency, with evidence of primacy in Experiment 3 only. Experiment 2 replicated Experiment 1, with reduced interstimulus intervals, and produced a null effect of serial position. The ease with which the odors could be verbally labeled was manipulated in Experiments 4 and 5. Nameable odors produced a null effect of serial position (Experiment 4), and hard-to-name odors produced a pronounced recency effect (Experiment 5); nevertheless, overall rates of recognition were remarkably similar for the two experiments at around 70%. Articulatory suppression reduced recognition accuracy (Experiment 6), but recency was again present in the absence of primacy. Odor recognition performance was immune to the effects of an interleaved odor (Experiment 7), and, again, both primacy and recency effects were absent. There was no evidence of olfactory fatigue: Recognition accuracy improved across trials (Experiment 1). It is argued that the results of the experiments reported here are generally consistent with that body of work employing hard-to-name visual stimuli, where recency is obtained in the absence of primacy when the retention interval is short.

  9. Transducer-based fiber Bragg grating high-temperature sensor with enhanced range and stability

    Science.gov (United States)

    Mamidi, Venkata Reddy; Kamineni, Srimannarayana; Ravinuthala, Lakshmi Narayana Sai Prasad; Tumu, Venkatappa Rao

    2017-09-01

    Fiber Bragg grating (FBG)-based high-temperature sensor with enhanced-temperature range and stability has been developed and tested. The sensor consists of an FBG and a mechanical transducer, which furnishes a linear temperature-dependent tensile strain on FBG by means of differential linear thermal expansion of two different ceramic materials. The designed sensor is tested over a range: 20°C to 1160°C and is expected to measure up to 1500°C.

  10. Selection for wide adaptability and high phenotypic stability of Brazilian soybean genotypes.

    Science.gov (United States)

    Oliveira, V M; Hamawaki, O T; Nogueira, A O; Sousa, L B; Santos, F M; Hamawaki, R L

    2016-03-31

    Advances in genetic enhancement techniques have led to an increase in soybean production. Thus, soybean is currently one the most economically important cultured species worldwide. The objectives of the present study were to study the interaction of soybean genotypes per environment in terms of grain productivity and to evaluate their phenotypic adaptability and stability, with the final aim of selecting lineages with high productivity, wide adaptability, and high stability. Seven soybean genotypes, consisting of five lineages developed by the soybean genetic enhancement program of the Universidade Federal de Uberlândia (Brazil) and two controls, were evaluated during several annual cycles in seven different environments. A randomized complete block design (RCBD) with three replicates was adopted in each site. This study followed the methodology proposed by Eberhart and Russel and Lin and Binns, with modifications by Carneiro, and the AMMI (additive main effects and multiplicative interaction model) analysis. The average productivity of soybean cultivars in the trials was 2739.26 kg/ha. The L01V13 genotype and the UFUS Guarani cultivar had wide adaptation according to the methodology proposed by Eberhart and Russel and Lin and Binns, with modifications by Carneiro. When analyzed with the AMMI model, the UFUS Guarani cultivar showed high stability. In general, the methodologies studied are complementary and, when used together, increase the reliability of the classification, providing support for the use of specific soybean cultivars in different environments.

  11. High-rate synthesis of phosphine-stabilized undecagold nanoclusters using a multilayered micromixer

    International Nuclear Information System (INIS)

    Jin, Hyung Dae; Chang, Chih-Hung; Garrison, Anna; Tseng, T; Paul, Brian K

    2010-01-01

    Growth in the potential applications of nanomaterials has led to a focus on the development of new manufacturing approaches for these materials. In particular, an increased demand due to the unique properties of nanomaterials requires a substantial yield of high-performance materials and a simultaneous reduction in the environmental impact of these processes. In this paper, a high-rate production of phosphine-stabilized undecagold nanoclusters was achieved using a layer-up strategy which involves the use of microlamination architectures; the patterning and bonding of thin layers of material (laminae) to create a multilayered micromixer in the range of 25-250 μm thick was used to step up the production of phosphine-stabilized undecagold nanoclusters. The continuous production of highly monodispersed phosphine-stabilized undecagold nanoclusters at a rate of about 11.8 (mg s -1 ) was achieved using a microreactor with a size of 1.687 cm 3 . This result is about 500 times over conventional batch syntheses based on the production rate per reactor volume.

  12. Stability of an Extemporaneously Compounded Oral Suspension of Bosentan.

    Science.gov (United States)

    Malik, Alina; Gorman, Gregory; Coward, Lori; Arnold, John J

    2016-05-01

    To assess the stability of an extemporaneously compounded oral suspension of bosentan from commercially available tablets for a period of 1 month. A 6.25 mg/mL oral suspension of bosentan monohydrate was prepared from Tracleer tablets. The bosentan suspension was then evenly divided between 2 light-resistant prescription bottles and stored in the dark either under refrigeration (4-8°C) or at controlled room temperature (21-26°C). The suspensions were assessed for physical changes (ease of resuspendability, change in color, change in odor), and samples were drawn immediately after preparation and on days 0, 1, 3, 7, 10, 14, 21, 28, and 31. Samples were analyzed at each time point by high-performance liquid chromatography (HPLC) utilizing a reversed-phase column with chemical stability defined as the retention of at least 90% of the initial intact bosentan concentration measured. No change in suspendability, color, or odor of the compounded bosentan suspensions was noted throughout the storage period. Furthermore, regardless of storage conditions, the oral suspension of bosentan retained at least 94% of the active pharmaceutical ingredient for 31 days after preparation. The results of our study indicate that a 6.25 mg/mL bosentan oral suspension stored in the dark under refrigeration and at room temperature maintains physical and chemical stability for 1 month.

  13. Identification of odor-processing genes in the emerald ash borer, Agrilus planipennis.

    Science.gov (United States)

    Mamidala, Praveen; Wijeratne, Asela J; Wijeratne, Saranga; Poland, Therese; Qazi, Sohail S; Doucet, Daniel; Cusson, Michel; Beliveau, Catherine; Mittapalli, Omprakash

    2013-01-01

    Insects rely on olfaction to locate food, mates, and suitable oviposition sites for successful completion of their life cycle. Agrilus planipennis Fairmaire (emerald ash borer) is a serious invasive insect pest that has killed tens of millions of North American ash (Fraxinus spp) trees and threatens the very existence of the genus Fraxinus. Adult A. planipennis are attracted to host volatiles and conspecifics; however, to date no molecular knowledge exists on olfaction in A. planipennis. Hence, we undertook an antennae-specific transcriptomic study to identify the repertoire of odor processing genes involved in A. planipennis olfaction. We acquired 139,085 Roche/454 GS FLX transcriptomic reads that were assembled into 30,615 high quality expressed sequence tags (ESTs), including 3,249 isotigs and 27,366 non-isotigs (contigs and singletons). Intriguingly, the majority of the A. planipennis antennal transcripts (59.72%) did not show similarity with sequences deposited in the non-redundant database of GenBank, potentially representing novel genes. Functional annotation and KEGG analysis revealed pathways associated with signaling and detoxification. Several odor processing genes (9 odorant binding proteins, 2 odorant receptors, 1 sensory neuron membrane protein and 134 odorant/xenobiotic degradation enzymes, including cytochrome P450s, glutathione-S-transferases; esterases, etc.) putatively involved in olfaction processes were identified. Quantitative PCR of candidate genes in male and female A. planipennis in different developmental stages revealed developmental- and sex-biased expression patterns. The antennal ESTs derived from A. planipennis constitute a rich molecular resource for the identification of genes potentially involved in the olfaction process of A. planipennis. These findings should help in understanding the processing of antennally-active compounds (e.g. 7-epi-sesquithujene) previously identified in this serious invasive pest.

  14. Use of n-butanol as an odorant to standardize the organoleptic scale of breath odour judges.

    Science.gov (United States)

    Saad, S; Greenman, J; Duffield, J; Sudlow, K

    2005-01-01

    The alcohol n-butanol has been recommended for use as a standard odorant by various groups for the training or standardization of breath odour judges and sensory evaluation panels. The objective of this study is to assess the use of n-butanol as a suitable odorant for organoleptic training of breath judges. One judge with full smell acuity was trained in the method of organoleptic assessment using odorant solutions of main chemical classes (acids, amines, indole and sulphides) with the exception of alcohols. The subject was proficient in scoring odorant solutions, standard gas mixtures and human breath using the Rosenberg 0-5 organoleptic scale. A wide range of n-butanol solutions were prepared from 0 to 90 000 ppm and dispensed as replicate 12-ml volumes in Universal bottles (24 ml) leaving a headspace of 12 ml. Sets of odorants were prepared, labelled by code, randomized and presented to the judge in a completely blind fashion. The judge scored each concentration. This process was repeated on 32 occasions over a period of 12 weeks. Mean values of data for each determination for each concentration series were plotted against the log concentrations of odorant. Linear regression slope analysis was used to measure slope, the 95% CI of slope and the scatter of points (R2 value). Headspace concentrations of odorant were determined using gas chromatography (GC) analysis. The n-butanol regression slope gave a high R(2) value (0.971) and low scatter. However, the data did not correspond to other published work using an ASTM method where the range of recommended butanol concentrations was insufficient at both the high and low ends to determine the top and threshold. Moreover, headspace analysis using GC confirmed the published gas concentrations to be in error by a factor of 100. It was also observed that high concentrations of odorants were irritant causing desensitization if used for prolonged periods. The published method had erroneous headspace calculations listed and

  15. Mechanisms of Loss of Agricultural Odorous Compounds in Sample Bags of Nalophan, Tedlar, and PTFE.

    Science.gov (United States)

    Kasper, Pernille Lund; Oxbøl, Arne; Hansen, Michael Jørgen; Feilberg, Anders

    2018-03-01

    Alteration of the chemical composition of odor samples during storage in polymer sample bags can significantly impair the accuracy of subsequent odor evaluations. To overcome or minimize this effect, the mechanisms determining compound loss must be more thoroughly understood. The present study examines the storage stability of a selection of key odorants from livestock production in polymer sample bags of Nalophan, Tedlar, and polytetrafluoroethylene (PTFE). The compounds included are acetic acid, butanoic acid, propanoic acid, 3-methylbutanoic acid, hydrogen sulfide, methanethiol, dimethyl sulfide, trimethylamine, and 4-methylphenol. The fate of the unrecovered compound fractions is clarified by means of thermal desorption and concentric double bags, allowing estimation of the magnitude of losses due to adsorption and diffusion, respectively. The degree of recovery was found to be PTFE > Tedlar > Nalophan, and smaller ratios of bag surface area to sample volume improved the recovery significantly. Furthermore, PTFE bags were found far superior for maintaining the original sample humidity and for storing 4-methylphenol. Analysis of sample humidity, partitioning coefficients, and thermal desorption suggested that the loss in PTFE bags was mainly controlled by adsorption, whereas for Nalophan and Tedlar, compound loss is a combined effect of adsorption and diffusion. It is suggested to heat the bags when evacuating the sample for analysis, as this was found to improve the recovery significantly. For a 5-L PTFE bag, all odorants could be found at concentration levels between 71.6 and 98.8% even after 48 h of storage when heated to 57°C prior to analysis. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. The Chilean Recluse Spider (Araneae: Sicariidae) Displays Behavioral Responses to Conspecific Odors, but Not to Several General Odorants.

    Science.gov (United States)

    Calbiague, Victor Manuel; Olivares, Jesus; Olivares, Erick; Schmachtenberg, Oliver

    2017-09-01

    Spiders of the family Sicariidae pose a serious threat to affected populations, and Loxosceles laeta (Nicolet) is considered the most venomous species. Development of nontoxic olfaction-based spider repellents or traps is hindered by a current lack of knowledge regarding olfactory system function in arachnids. In the present study, general plant odorants and conspecific odors were tested for behavioral responses in L. laeta. Although general odorants triggered neither attraction nor aversion, conspecific odor of the opposite sex caused aversion in females, and attraction in males. These results support the presence of a specific olfactory system for the detection of conspecifics in L. laeta, but suggest the absence of a broadly tuned system for general odorant detection in this species. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. The Effect of High Pressure Techniques on the Stability of Anthocyanins in Fruit and Vegetables

    Directory of Open Access Journals (Sweden)

    Krystian Marszałek

    2017-01-01

    Full Text Available Anthocyanins are a group of phenolic compounds responsible for red, blue and violet colouration of many fruits, vegetables and flowers. The high content of these pigments is important as it influences directly their health promoting properties as well as the sensory quality of the product; however they are prone to degradation by, inter alia, elevated temperature and tissue enzymes. The traditional thermal methods of food preservation cause significant losses of these pigments. Thus, novel non-thermal techniques such as high pressure processing, high pressure carbon dioxide and high pressure homogenization are under consideration. In this review, the authors attempted to summarize the current knowledge of the impact of high pressure techniques on the stability of anthocyanins during processing and storage of fruit and vegetable products. Furthermore, the effect of the activity of enzymes involved in the degradation of these compounds has been described. The conclusions including comparisons of pressure-based methods with high temperature preservation techniques were presented.

  18. Rheological properties and physical stability of ecological emulsions stabilized by a surfactant derived from cocoa oil and high pressure homogenization

    Directory of Open Access Journals (Sweden)

    Trujillo-Cayado, L. A.

    2015-09-01

    Full Text Available The goal of this work was to investigate the influence of the emulsification method on the rheological properties, droplet size distribution and physical stability of O/W green emulsions formulated with an eco-friendly surfactant derived from cocoa oil. The methodology used can be applied to other emulsions. Polyoxyethylene glycerol esters are non-ionic surfactants obtained from a renewable source which fulfill the environmental and toxicological requirements to be used as eco-friendly emulsifying agents. In the same way, N,NDimethyloctanamide and α-Pinene (solvents used as oil phase could be considered green solvents. Emulsions with submicron mean diameters and slight shear thinning behavior were obtained regardless of the homogenizer, pressure or number of passes used. All emulsions exhibited destabilization by creaming and a further coalescence process which was applied to the coarse emulsion prepared with a rotor-stator homogenizer. The emulsion obtained with high pressure at 15000 psi and 1-pass was the most stable.El objetivo de este trabajo fue estudiar la influencia del método de emulsificación sobre las propiedades reológicas, la distribución de tamaños de gota y la estabilidad física de emulsiones verdes O/W formuladas con un tensioactivo derivado del aceite de coco respetuoso con el medioambiente. La metodología empleada puede ser aplicada a cualquier otro tipo de emulsiones. Los ésteres polietoxilados de glicerina son tensioactivos no iónicos obtenidos de fuentes renovables que cumplen requisitos medioambientales y toxicológicos para ser usados como agentes emulsionantes ecológicos. Del mismo modo, la N,N-dimetil octanamida y el α-Pineno (disolventes usados como fase oleosa pueden ser considerados como disolventes verdes. Se han obtenido emulsiones con diámetros medio submicrónicos y comportamiento ligeramente pseudoplástico independientemente del equipo, la presión o el número de pasadas empleados. Todas las

  19. Highly Stretchable and Transparent Supercapacitor by Ag-Au Core-Shell Nanowire Network with High Electrochemical Stability.

    Science.gov (United States)

    Lee, Habeom; Hong, Sukjoon; Lee, Jinhwan; Suh, Young Duk; Kwon, Jinhyeong; Moon, Hyunjin; Kim, Hyeonseok; Yeo, Junyeob; Ko, Seung Hwan

    2016-06-22

    Stretchable and transparent electronics have steadily attracted huge attention in wearable devices. Although Ag nanowire is the one of the most promising candidates for transparent and stretchable electronics, its electrochemical instability has forbidden its application to the development of electrochemical energy devices such as supercapacitors. Here, we introduce a highly stretchable and transparent supercapacitor based on electrochemically stable Ag-Au core-shell nanowire percolation network electrode. We developed a simple solution process to synthesize the Ag-Au core-shell nanowire with excellent electrical conductivity as well as greatly enhanced chemical and electrochemical stabilities compared to pristine Ag nanowire. The proposed core-shell nanowire-based supercapacitor still possesses fine optical transmittance and outstanding mechanical stability up to 60% strain. The Ag-Au core-shell nanowire can be a strong candidate for future wearable electrochemical energy devices.

  20. Picosecond stability of injection of parallel high-current pulsed electron beams

    Science.gov (United States)

    Yalandin, M. I.; Reutova, A. G.; Ul'Maskulov, M. R.; Sharypov, K. A.; Shpak, V. G.; Shunailov, S. A.; Klimov, A. I.; Rostov, V. V.; Mesyats, G. A.

    2009-09-01

    The stability of operation of parallel explosive-emission cathodes driven by a split high-voltage pulse with a subnanosecond leading front has been studied. It is established that, upon the training of graphite cathodes in vacuum with up to ˜104 pulses, the current pulse fronts of injected high-current electron beams exhibit a mutual temporal dispersion not exceeding ten picoseconds. The dynamics of this parameter during the training stage, the variation of the absolute spread, and the growth of a relative delay of the moments of beam injection have been investigated.

  1. Antioxidant-Based Phase-Change Thermal Interface Materials with High Thermal Stability

    Science.gov (United States)

    Aoyagi, Yasuhiro; Chung, D. D. L.

    2008-04-01

    This work provides phase-change thermal interface materials (TIMs) with high thermal stability and high heat of fusion. They are based on antioxidants mainly in the form of hydrocarbons with linear segments. The thermal stability is superior to paraffin wax and four commercial phase-change materials (PCMs). The use of 98.0 wt.% thiopropionate antioxidant (SUMILIZER TP-D) with 2.0 wt.% sterically half-hindered phenolic antioxidant (GA80) as the matrix and the use of 16 vol.% boron nitride particles as the solid component give a PCM with a 100°C lifetime indicator of 5.3 years, in contrast to 0.95 year or less for the commercial PCMs. The heat of fusion is much higher than those of commercial PCMs; the values for antioxidants with nonbranched molecular structures exceed that of wax; the value for one with a branched structure is slightly below that of wax. The phase-change properties are degraded by heating at 150°C much less than those of the commercial PCMs. The stability of the heat of fusion upon phase-change cycling is also superior. The viscosity is essentially unaffected by heating at 150°C. Commercial PCMs give slightly lower values of the thermal contact conductance for the case of rough (12 μm) mating surfaces, in spite of the lower values of the bond-line thickness.

  2. Scalable high-affinity stabilization of magnetic iron oxide nanostructures by a biocompatible antifouling homopolymer

    KAUST Repository

    Luongo, Giovanni

    2017-10-12

    Iron oxide nanostructures have been widely developed for biomedical applications, due to their magnetic properties and biocompatibility. In clinical application, the stabilization of these nanostructures against aggregation and non-specific interactions is typically achieved using weakly anchored polysaccharides, with better-defined and more strongly anchored synthetic polymers not commercially adopted due to complexity of synthesis and use. Here, we show for the first time stabilization and biocompatibilization of iron oxide nanoparticles by a synthetic homopolymer with strong surface anchoring and a history of clinical use in other applications, poly(2-methacryloyloxyethy phosphorylcholine) (poly(MPC)). For the commercially important case of spherical particles, binding of poly(MPC) to iron oxide surfaces and highly effective individualization of magnetite nanoparticles (20 nm) are demonstrated. Next-generation high-aspect ratio nanowires (both magnetite/maghemite and core-shell iron/iron oxide) are furthermore stabilized by poly(MPC)-coating, with nanowire cytotoxicity at large concentrations significantly reduced. The synthesis approach is exploited to incorporate functionality into the poly(MPC) chain is demonstrated by random copolymerization with an alkyne-containing monomer for click-chemistry. Taking these results together, poly(MPC) homopolymers and random copolymers offer a significant improvement over current iron oxide nanoformulations, combining straightforward synthesis, strong surface-anchoring and well-defined molecular weight.

  3. Network structure and thermal stability study of high temperature seal glass

    Science.gov (United States)

    Lu, K.; Mahapatra, M. K.

    2008-10-01

    High temperature seal glass has stringent requirement on glass thermal stability, which is dictated by glass network structures. In this study, a SrO-La2O3-Al2O3-B2O3-SiO2 based glass system was studied using nuclear magnetic resonance, Raman spectroscopy, and x-ray diffraction for solid oxide cell application purpose. Glass structural unit neighboring environment and local ordering were evaluated. Glass network connectivity as well as silicon and boron glass former coordination were calculated for different B2O3:SiO2 ratios. Thermal stability of the borosilicate glasses was studied after thermal treatment at 850 °C. The study shows that high B2O3 content induces BO4 and SiO4 structural unit ordering, increases glass localized inhomogeneity, decreases glass network connectivity, and causes devitrification. Glass modifiers interact with either silicon- or boron-containing structural units and form different devitrified phases at different B2O3:SiO2 ratios. B2O3-free glass shows the best thermal stability among the studied compositions, remaining stable after thermal treatment for 200 h at 850 °C.

  4. On the optical stability of high-resolution transmission electron microscopes

    International Nuclear Information System (INIS)

    Barthel, J.; Thust, A.

    2013-01-01

    In the recent two decades the technique of high-resolution transmission electron microscopy experienced an unprecedented progress through the introduction of hardware aberration correctors and by the improvement of the achievable resolution to the sub-Ångström level. The important aspect that aberration correction at a given resolution requires also a well defined amount of optical stability has received little attention so far. Therefore we investigate the qualification of a variety of high-resolution electron microscopes to maintain an aberration corrected optical state in terms of an optical lifetime. We develop a comprehensive statistical framework for the estimation of the optical lifetime and find remarkably low values between tens of seconds and a couple of minutes. Probability curves are introduced, which inform the operator about the chance to work still in the fully aberration corrected state. - Highlights: • We investigate the temporal stability of optical aberrations in HRTEM. • We develop a statistical framework for the estimation of optical lifetimes. • We introduce plots showing the success probability for aberration-free work. • Optical lifetimes in sub-Ångström electron microscopy are surprisingly low. • The success of aberration correction depends strongly on the optical stability

  5. Constraints on very-high-β, edge-stabilized tandem-mirror reactors

    Science.gov (United States)

    Potok, R. E.

    1985-08-01

    There are several tandem-mirror schemes which propose a very high β and edge stabilization for the center-cell plasma ( β being the ratio of the plasma pressure to the vacuum magnetic-field pressure). While the exact criteria for the edge stabilization are uncertain, it is possible to analyze the option space in which a very-high- β mirror reactor would operate. The primary physics constraints on such a reactor are the energy balance at ignition, the buildup of He4 ash and the hot α-particle β( β {α/hot}), and the need for adiabatic conservation of the hot α-particle gyro-orbits in the axial field gradients at the center-cell ends. There are also engineering constraints on the allowable wall loading and plant size. In this paper, a wall-stabilized tandem-mirror reactor is analyzed and is found to be an attractive device requiring low center-cell vacuum fields (of the order of 2 to 3 tesla). A primary requirement is that the plasma edge have a thermal conductivity near classical values.

  6. Experimental investigation on ballistic stability of high-speed projectile in sand

    Science.gov (United States)

    Zhang, Wei; Qi, Yafei; Huang, Wei; Li, Dacheng; Hypervelocity Impact Research Center Team

    2015-06-01

    The investigation on ballistic stability of high-speed projectile in granular materials is important to the study of the earth penetrating weapon(EPW). Laboratory-scaled sand entry experiments for the trajectory in the sand have been performed with four different nosed projectiles at a range of velocities from 20 m/s to 250 m/s. The slender projectiles were designed into flat, ogival, hemi-sperical, truncated-ogival nose shapes to make comparisons on the trajectory when those projectiles were launched at vertical and oblique impact angles (0° ~ 25°) along a view window. A high-speed camera placed at the side of the window was employed to capture the entire process of projectiles' penetration. Basing on the comparison of different tests, theoretical analysis is carried out on the relationships between ballistic stability and associated conditions. It can be obtained that projectile with flat nose has the best ballistic stability, followed by truncated-ogival nose, and ogival nose is the least at the same velocity. Additionally, a semi-empirical model based on a corrected drag coefficient is established to predict the depth of penetration. National Natural Science Foundation of China (NO.: 11372088)

  7. Polyethylene Glycol Based Graphene Aerogel Confined Phase Change Materials with High Thermal Stability.

    Science.gov (United States)

    Fu, Yang; Xiong, Weilai; Wang, Jianying; Li, Jinghua; Mei, Tao; Wang, Xianbao

    2018-05-01

    Polyethylene glycol (PEG) based graphene aerogel (GA) confined shaped-stabilized phase change materials (PCMs) are simply prepared by a one-step hydrothermal method. Three-dimensional GA inserted by PEG molecule chains, as a supporting material, obtained by reducing graphene oxide sheets, is used to keep their stabilized shape during a phase change process. The volume of GA is obviously expended after adding PEG, and only 9.8 wt% of GA make the composite achieve high energy efficiency without leakage during their phase change because of hydrogen bonding widely existing in the GA/PEG composites (GA-PCMs). The heat storage energy of GA-PCMs is 164.9 J/g, which is 90.2% of the phase change enthalpy of pure PEG. In addition, this composite inherits the natural thermal properties of graphene and thus shows enhanced thermal conductivity compared with pure PEG. This novel study provides an efficient way to fabricate shape-stabilized PCMs with a high content of PEG for thermal energy storage.

  8. Ceramic stabilization of hazardous wastes: a high performance room temperature process

    International Nuclear Information System (INIS)

    Maloney, M.D.

    1996-01-01

    ANL has developed a room-temperature process for converting hazardous materials to a ceramic structure. It is similar to vitrification but is achieved at low cost, similar to conventional cement stabilization. The waste constituents are both chemically stabilized and physically encapsulated, producing very low leaching levels and the potential for delisting. The process, which is pH-insensitive, is ideal for inorganic sludges and liquids, as well as mixed chemical-radioactive wastes, but can also handle significant percentages of salts and even halogenated organics. High waste loadings are possible and densification occurs,so that volumes are only slightly increased and in some cases (eg, incinerator ash) are reduced. The ceramic product has strength and weathering properties far superior to cement products

  9. Thermal Stability and Rheological Behaviors of High-Density Polyethylene/Fullerene Nanocomposites

    Directory of Open Access Journals (Sweden)

    Liping Zhao

    2012-01-01

    Full Text Available High-density polyethylene/fullerene (HDPE/C60 nanocomposites with the C60 loading that varied from 0.5 to 5.0% by weight were prepared via melt compounding. Thermogravimetric analysis (TGA and differential scanning calorimetry (DSC results showed that the presence of C60 could remarkably enhance the thermal properties of HDPE. A very low C60 loading (0.5 wt% increased the onset degradation temperature from 389∘C to 459∘C and decreased the heat release from 3176 J/g to 1490 J/g. The larger the loading level of C60, the better the thermal stability of HDPE/C60 nanocomposites. Rheological investigation results showed that the free radical trapping effect of C60 was responsible for the improved thermal stability of HDPE.

  10. Stability of uranium(VI) doped CSH phases in high saline water

    Energy Technology Data Exchange (ETDEWEB)

    Wolter, Jan-Martin; Schmeide, Katja [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes

    2017-06-01

    To evaluate the long-term stability of U(VI) doped calcium silicate hydrate (CSH) phases at high saline conditions, leaching experiments with NaCl, NaCl/Na{sub 2}SO{sub 4} and NaCl/NaHCO{sub 3} containing solutions were performed. Time-resolved laser-induced fluorescence spectroscopy (TRLFS), infrared spectroscopy (IR) and X-ray powder diffraction (XRD) were applied to study the U(VI) binding onto the CSH phases and to get a deeper understanding of structural changes due to leaching. Results indicate that neither NaCl nor Na{sub 2}SO{sub 4} affect the structural stability of CSH phases and their retention potential for U(VI). However, carbonate containing solutions lead to a decomposition of CSH phases and thus, to a release of incorporated uranium.

  11. High passive-stability diode-laser design for use in atomic-physics experiments

    Science.gov (United States)

    Cook, Eryn C.; Martin, Paul J.; Brown-Heft, Tobias L.; Garman, Jeffrey C.; Steck, Daniel A.

    2012-04-01

    We present the design and performance characterization of an external-cavity diode-laser system optimized for high stability, low passive spectral linewidth, low cost, and ease of in-house assembly. The main cavity body is machined from a single aluminum block for robustness to temperature changes and mechanical vibrations, and features a stiff and light diffraction-grating arm to suppress low-frequency mechanical resonances. The cavity is vacuum sealed, and a custom-molded silicone external housing further isolates the system from acoustic noise and temperature fluctuations. Beam shaping, optical isolation, and fiber coupling are integrated, and the design is easily adapted to many commonly used wavelengths. Resonance data, passive-linewidth data, and passive stability characterization of the new design demonstrate that its performance exceeds published specifications for commercial precision diode-laser systems. The design is fully documented and freely available.

  12. Stability analysis of the high temperature thermal pebble bed nuclear reactor concept

    International Nuclear Information System (INIS)

    Vondy, D.R.

    1981-02-01

    A study was made of the stability of the high temperature gas-cooled pebble bed core against xenon-driven oscillation. This generic study indicated that a core as large as 3000 MW(t) could be stable. Several aspects present a challenge to analysis including the void space above the pebble bed, the effects of possible control rod configurations, and the temperature feedback contribution. Special methods of analysis were developed in this effort. Of considerable utility was the scheme of including an azimuthal buckling loss term in the neturon balance equations admitting direct solution of the first azimuthal harmonic for a core having azimuthal symmetry. This technique allows the linear stability analysis to be done solving two-dimensional (RZ) problems instead of three-dimensional problems. A scheme for removing the fundamental source contribution was also implemented to allow direct iteration toward the dominant harmonic solution, treating up to three dimensions with diffusion theory

  13. Predicting Odor Pleasantness from Odorant Structure: Pleasantness as a Reflection of the Physical World

    Science.gov (United States)

    2009-11-01

    evolutionary mechanism. To automatically reject food that smells fermented is generally a safe bet. However, if through experience one learns that...exceptions exist, and for example fermented fish can be both tasty and healthy, than its pleasantness representation may shift. This is what allows...dimentional space made of the first and second PCs. The 9 odorants used in Experiment 1(acetophenone, amyl acetate, diphenyl oxide, ethyl butyrate , eugenol

  14. High stability of self-assembled peptide nanowires against thermal, chemical, and proteolytic attacks.

    Science.gov (United States)

    Ryu, Jungki; Park, Chan Beum

    2010-02-01

    Understanding the self-assembly of peptides into ordered nanostructures is recently getting much attention since it can provide an alternative route for fabricating novel bio-inspired materials. In order to realize the potential of the peptide-based nanofabrication technology, however, more information is needed regarding the integrity or stability of peptide nanostructures under the process conditions encountered in their applications. In this study, we investigated the stability of self-assembled peptide nanowires (PNWs) and nanotubes (PNTs) against thermal, chemical, proteolytic attacks, and their conformational changes upon heat treatment. PNWs and PNTs were grown by the self-assembly of diphenylalanine (Phe-Phe), a peptide building block, on solid substrates at different chemical atmospheres and temperatures. The incubation of diphenylalanine under aniline vapor at 150 degrees C led to the formation of PNWs, while its incubation with water vapor at 25 degrees C produced PNTs. We analyzed the stability of peptide nanostructures using multiple tools, such as electron microscopy, thermal analysis tools, circular dichroism, and Fourier-transform infrared spectroscopy. Our results show that PNWs are highly stable up to 200 degrees C and remain unchanged when incubated in aqueous solutions (from pH 1 to 14) or in various chemical solvents (from polar to non-polar). In contrast, PNTs started to disintegrate even at 100 degrees C and underwent a conformational change at an elevated temperature. When we further studied their resistance to a proteolytic environment, we discovered that PNWs kept their initial structure while PNTs fully disintegrated. We found that the high stability of PNWs originates from their predominant beta-sheet conformation and the conformational change of diphenylalanine nanostructures. Our study suggests that self-assembled PNWs are suitable for future nano-scale applications requiring harsh processing conditions. 2009 Wiley Periodicals, Inc.

  15. Phase inversion of ionomer-stabilized emulsions to form high internal phase emulsions (HIPEs).

    Science.gov (United States)

    Zhang, Tao; Xu, Zhiguang; Cai, Zengxiao; Guo, Qipeng

    2015-06-28

    Herein, we report the phase inversion of ionomer-stabilized emulsions to form high internal phase emulsions (HIPEs) induced by salt concentration and pH changes. The ionomers are sulfonated polystyrenes (SPSs) with different sulfonation degrees. The emulsion types were determined by conductivity measurements, confocal microscopy and optical microscopy, and the formation of HIPE organogels was verified by the tube-inversion method and rheological measurements. SPSs with high sulfonation degrees (water-soluble) and low sulfonation degrees (water-insoluble) can stabilize oil-in-water emulsions; these emulsions were transformed into water-in-oil HIPEs by varying salt concentrations and/or changing the pH. SPS, with a sulfonation degree of 11.6%, is the most efficient, and as low as 0.2 (w/v)% of the organic phase is enough to stabilize the HIPEs. Phase inversion of the oil-in-water emulsions occurred to form water-in-oil HIPEs by increasing the salt concentration in the aqueous phase. Two phase inversion points from oil-in-water emulsions to water-in-oil HIPEs were observed at pH 1 and 13. Moreover, synergetic effects between the salt concentration and pH changes occurred upon the inversion of the emulsion type. The organic phase can be a variety of organic solvents, including toluene, xylene, chloroform, dichloroethane, dichloromethane and anisole, as well as monomers such as styrene, butyl acrylate, methyl methacrylate and ethylene glycol dimethacrylate. Poly(HIPEs) were successfully prepared by the polymerization of monomers as the continuous phase in the ionomer-stabilized HIPEs.

  16. Effects of visual priming on taste-odor interaction.

    Directory of Open Access Journals (Sweden)

    Marije van Beilen

    Full Text Available Little is known about the influence of visual characteristics other than colour on flavor perception, and the complex interactions between more than two sensory modalities. This study focused on the effects of recognizability of visual (texture information on flavor perception of odorized sweet beverages. Participants rated the perceived sweetness of odorized sucrose solutions in the presence or absence of either a congruent or incongruent visual context. Odors were qualitatively reminiscent of sweet foods (strawberry and caramel or not (savoury. Visual context was either an image of the same sweet foods (figurative context or a visual texture derived from this product (non-figurative context. Textures were created using a texture synthesis method that preserved perceived food qualities while removing object information. Odor-taste combinations were rated sweeter within a figurative than a non-figurative context. This behaviour was exhibited for all odor-taste combinations, even in trials without images, indicating sustained priming by figurative visual context. A non-figurative context showed a transient sweetening effect. Sweetness was generally enhanced most by the strawberry odor. We conclude that the degree of recognizability of visual information (figurative versus non-figurative, influences flavor perception differently. Our results suggest that this visual context priming is mediated by separate sustained and transient processes that are differently evoked by figurative and non-figurative visual contexts. These components operate independent of the congruency of the image-odor-taste combinations.

  17. Predator odor fear conditioning: Current perspectives and new directions

    Science.gov (United States)

    Takahashi, Lorey K.; Chan, Megan M.; Pilar, Mark L.

    2008-01-01

    Predator odor fear conditioning involves the use of a natural unconditioned stimulus, as opposed to aversive electric foot-shock, to obtain novel information on the neural circuitry associated with emotional learning and memory. Researchers are beginning to identify brain sites associated with conditioned contextual fear such as the ventral anterior olfactory nucleus, dorsal premammillary nucleus, ventrolateral periaqueductal gray, cuneiform nucleus, and locus coeruleus. In addition, a few studies have reported an involvement of the basolateral and medial nucleus of the amygdala and hippocampus in fear conditioning. However, several important issues concerning the effectiveness of different predator odor unconditioned stimuli to produce fear conditioning, the precise role of brain nuclei in fear conditioning, and the general relation between the current predator odor and the traditional electric foot-shock fear conditioning procedures remain to be satisfactorily addressed. This review discusses the major behavioral results in the current predator odor fear conditioning literature and introduces two novel contextual and auditory fear conditioning models using cat odor. The new models provide critical information on the acquisition of conditioned fear behavior during training and the expression of conditioned responses in the retention test. Future studies adopting fear conditioning procedures that incorporate measures of both unconditioned and conditioned responses during training may lead to broad insights into predator odor fear conditioning and identify specific brain nuclei mediating conditioned stimulus – predator odor unconditioned stimulus associations. PMID:18577397

  18. Odors eliciting fear: a conditioning approach to Idiopathic Environmental Intolerances.

    Science.gov (United States)

    Leer, Arne; Smeets, Monique A M; Bulsing, Patricia J; van den Hout, Marcel A

    2011-06-01

    Patients suffering from Idiopathic Environmental Intolerances (IEI) report health symptoms, referable to multiple organ systems, which are triggered by harmless odors and therefore medically unexplainable. In line with previous research that predominantly points towards psychological explanations, the present study tests the hypothesis that IEI symptoms result from learning via classical conditioning of odors to fear. A differential conditioning paradigm was employed. Hedonically different odors were compared on ease of fear acquisition. Conditioned stimuli (CSs) were Dimethyl Sulfide (unpleasant) and peach (pleasant). The unconditioned stimulus (US) was an electrical shock. During acquisition one odor (CS+) was followed by shock, while the other odor (CS-) was not. Next, fear extinction was tested by presenting both CS+ and CS- without US. Electrodermal response, odor evaluation, and sniffing behavior were monitored. Results showed successful fear conditioning irrespective of hedonic character as evidenced by electrodermal response. Acquired fear did not extinguish. There was no evidence of evaluative conditioning taking place, as CS evaluation did not change during fear acquisition. Early avoidance of the CS+, as deduced from odor inhalation measures, was demonstrated, but did not sustain during the entire acquisition phase. This study suggests that a fear conditioning account of IEI is only partially satisfactory. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Numerical simulation of airway dimension effects on airflow patterns and odorant deposition patterns in the rat nasal cavity.

    Directory of Open Access Journals (Sweden)

    Zehong Wei

    Full Text Available The sense of smell is largely dependent on the airflow and odorant transport in the nasal cavity, which in turn depends on the anatomical structure of the nose. In order to evaluate the effect of airway dimension on rat nasal airflow patterns and odorant deposition patterns, we constructed two 3-dimensional, anatomically accurate models of the left nasal cavity of a Sprague-Dawley rat: one was based on high-resolution MRI images with relatively narrow airways and the other was based on artificially-widening airways of the MRI images by referencing the section images with relatively wide airways. Airflow and odorant transport, in the two models, were determined using the method of computational fluid dynamics with finite volume method. The results demonstrated that an increase of 34 µm in nasal airway dimension significantly decreased the average velocity in the whole nasal cavity by about 10% and in the olfactory region by about 12% and increased the volumetric flow into the olfactory region by about 3%. Odorant deposition was affected to a larger extent, especially in the olfactory region, where the maximum odorant deposition difference reached one order of magnitude. The results suggest that a more accurate nasal cavity model is necessary in order to more precisely study the olfactory function of the nose when using the rat.

  20. Identification of predominant odorants in thai desserts flavored by smoking with "Tian Op", a traditional Thai scented candle.

    Science.gov (United States)

    Watcharananun, Wanwarang; Cadwallader, Keith R; Huangrak, Kittiphong; Kim, Hun; Lorjaroenphon, Yaowapa

    2009-02-11

    "Tian Op", a traditional Thai scented candle, is used for the smoking and flavoring of sweets, cakes, and other desserts for the purpose of adding a unique aroma to the final product. Gas chromatography-olfactometry, aroma extract dilution analysis, and GC-MS were applied to identify the potent odorants in two types of traditional Thai desserts ("num dok mai" and "gleep lum duan") prepared using a Tian Op smoking process. On the basis of the results of AEDA and calculated odor-activity values, the predominant odorants in the Tian Op flavored desserts were vinyl ketones (C(5)-C(9)), n-aldehydes (C(5)-C(11)), (E)-2-unsaturated aldehydes (C(8)-C(11)), and omega-1-unsaturated aldehydes (C(8) and C(9)). Sensory studies of model mixtures confirmed the importance of n-aldehydes, omega-1-unsaturated aldehydes, and guaiacol as predominant odorants; however, the results showed that vinyl ketones and (E)-2-unsaturated aldehydes, despite having high odor-activity values, may be of only minor importance in the typical aroma profiles of traditional Tian Op smoked desserts.

  1. Comparison between low doses of TMT and cat odor exposure in anxiety- and fear-related behaviors in mice.

    Science.gov (United States)

    Hacquemand, R; Choffat, N; Jacquot, L; Brand, G

    2013-02-01

    Few comparisons were made between cat odor and synthetic fox odor (TMT) to study fear and anxiety in rodents. TMT is frequently used are at high concentration while the stimulus should be as possible closer to natural conditions. The aim of this work was to compare behavioral responses of mice exposed to cat odor and low doses of TMT (i.e. 10 μl of a solution containing 1%, 0.1% or 0.01% TMT). Behavioral parameters were recorded in elevated plus-maze and in open field. Results showed that 1% TMT and 0.1% TMT induced similar responses to cat odor, contrary to water and 0.01% TMT which failed to elicit fear or anxiety-related behaviors. Additionally, behavioral changes were more marked in EPM - e.g. time spent in open arms - than in open field - e.g. freezing. These findings are discussed in terms of a possible continuum of mild anxiety-like behaviors to strong fear-like behaviors linked to predator odor intensity. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Olfactory bulb glomerular NMDA receptors mediate olfactory nerve potentiation and odor preference learning in the neonate rat.

    Directory of Open Access Journals (Sweden)

    Rebecca Lethbridge

    Full Text Available Rat pup odor preference learning follows pairing of bulbar beta-adrenoceptor activation with olfactory input. We hypothesize that NMDA receptor (NMDAR-mediated olfactory input to mitral cells is enhanced during training, such that increased calcium facilitates and shapes the critical cAMP pattern. Here, we demonstrate, in vitro, that olfactory nerve stimulation, at sniffing frequencies, paired with beta-adrenoceptor activation, potentiates olfactory nerve-evoked mitral cell firing. This potentiation is blocked by a NMDAR antagonist and by increased inhibition. Glomerular disinhibition also induces NMDAR-sensitive potentiation. In vivo, in parallel, behavioral learning is prevented by glomerular infusion of an NMDAR antagonist or a GABA(A receptor agonist. A glomerular GABA(A receptor antagonist paired with odor can induce NMDAR-dependent learning. The NMDA GluN1 subunit is phosphorylated in odor-specific glomeruli within 5 min of training suggesting early activation, and enhanced calcium entry, during acquisition. The GluN1 subunit is down-regulated 3 h after learning; and at 24 h post-training the GluN2B subunit is down-regulated. These events may assist memory stability. Ex vivo experiments using bulbs from trained rat pups reveal an increase in the AMPA/NMDA EPSC ratio post-training, consistent with an increase in AMPA receptor insertion and/or the decrease in NMDAR subunits. These results support a model of a cAMP/NMDA interaction in generating rat pup odor preference learning.

  3. Rheological properties and physical stability of ecological emulsions stabilized by a surfactant derived from cocoa oil and high pressure homogenization

    OpenAIRE

    Trujillo-Cayado, L. A.; Natera, A.; García, M. C.; Muñoz, J.; Alfaro, M. C.

    2015-01-01

    The goal of this work was to investigate the influence of the emulsification method on the rheological properties, droplet size distribution and physical stability of O/W green emulsions formulated with an eco-friendly surfactant derived from cocoa oil. The methodology used can be applied to other emulsions. Polyoxyethylene glycerol esters are non-ionic surfactants obtained from a renewable source which fulfill the environmental and toxicological requirements to be used as eco-fri...

  4. Emissions of odorous aldehydes from alkyd paint

    Science.gov (United States)

    Chang, John C. S.; Guo, Zhishi

    Aldehyde emissions are widely held responsible for the acrid after-odor of drying alkyd-based paint films. The aldehyde emissions from three different alkyd paints were measured in small environ-mental chambers. It was found that, for each gram of alkyd paint applied, more than 2 mg of aldehydes (mainly hexanal) were emitted during the curing (drying) period. Since no measurable hexanal was found in the original paint, it is suspected that the aldehydes emitted were produced by autoxidation of the unsaturated fatty acid esters in the alkyd resins. The hexanal emission rate was simulated by a model assuming that the autoxidation process was controlled by a consecutive first-order reaction mechanism. Using the emission rate model, indoor air quality simulation indicated that the hexanal emissions can result in prolonged (several days) exposure risk to occupants. The occupant exposure to aldehydes emitted from alkyd paint also could cause sensory irritation and other health concerns.

  5. Atomistic Origins of High Capacity and High Structural Stability of Polymer-Derived SiOC Anode Materials.

    Science.gov (United States)

    Sun, Hong; Zhao, Kejie

    2017-10-11

    Capacity and structural stability are often mutually exclusive properties of electrodes in Li-ion batteries (LIBs): a gain in capacity is usually accompanied by the undesired large volumetric change of the host material upon lithiation. Polymer-derived ceramics, such as silicon oxycarbide (SiOC) of hybrid Si-O-C bonds, show an exceptional combination of high capacity and superior structural stability. We investigate the atomistic origins of the unique chemomechanical performance of carbon-rich SiOC using the first-principles theoretical approach. The atomic model of SiOC is composed of continuous Si-O-C units caged by a graphene-like cellular network and percolated nanovoids. The segregated sp 2 carbon network serves as the backbone to maintain the structural stability of the lattice. Li insertion is first absorbed at the nanovoid sites, and then it is accommodated by the SiOC tetrahedral units, excess C atoms, and topological defects at the edge of or within the segregated carbon network. SiOC expands up to 22% in volumetric strain at the fully lithiated capacity of 1230 mA h/g. We examine in great detail the evolution of the microscopic features of the SiOC molecule in the course of Li reactions. The first-principles modeling provides a fundamental understanding of the physicochemical properties of Si-based glass ceramics for their application in LIBs.

  6. Stability of the high-order finite elements for acoustic or elastic wave propagation with high-order time stepping

    KAUST Repository

    De Basabe, Jonás D.

    2010-04-01

    We investigate the stability of some high-order finite element methods, namely the spectral element method and the interior-penalty discontinuous Galerkin method (IP-DGM), for acoustic or elastic wave propagation that have become increasingly popular in the recent past. We consider the Lax-Wendroff method (LWM) for time stepping and show that it allows for a larger time step than the classical leap-frog finite difference method, with higher-order accuracy. In particular the fourth-order LWM allows for a time step 73 per cent larger than that of the leap-frog method; the computational cost is approximately double per time step, but the larger time step partially compensates for this additional cost. Necessary, but not sufficient, stability conditions are given for the mentioned methods for orders up to 10 in space and time. The stability conditions for IP-DGM are approximately 20 and 60 per cent more restrictive than those for SEM in the acoustic and elastic cases, respectively. © 2010 The Authors Journal compilation © 2010 RAS.

  7. Functional evolution of mammalian odorant receptors.

    Directory of Open Access Journals (Sweden)

    Kaylin A Adipietro

    Full Text Available The mammalian odorant receptor (OR repertoire is an attractive model to study evolution, because ORs have been subjected to rapid evolution between species, presumably caused by changes of the olfactory system to adapt to the environment. However, functional assessment of ORs in related species remains largely untested. Here we investigated the functional properties of primate and rodent ORs to determine how well evolutionary distance predicts functional characteristics. Using human and mouse ORs with previously identified ligands, we cloned 18 OR orthologs from chimpanzee and rhesus macaque and 17 mouse-rat orthologous pairs that are broadly representative of the OR repertoire. We functionally characterized the in vitro responses of ORs to a wide panel of odors and found similar ligand selectivity but dramatic differences in response magnitude. 87% of human-primate orthologs and 94% of mouse-rat orthologs showed differences in receptor potency (EC50 and/or efficacy (dynamic range to an individual ligand. Notably dN/dS ratio, an indication of selective pressure during evolution, does not predict functional similarities between orthologs. Additionally, we found that orthologs responded to a common ligand 82% of the time, while human OR paralogs of the same subfamily responded to the common ligand only 33% of the time. Our results suggest that, while OR orthologs tend to show conserved ligand selectivity, their potency and/or efficacy dynamically change during evolution, even in closely related species. These functional changes in orthologs provide a platform for examining how the evolution of ORs can meet species-specific demands.

  8. Aversive olfactory associative memory loses odor specificity over time.

    Science.gov (United States)

    König, Christian; Antwi-Adjei, Emmanuel; Ganesan, Mathangi; Kilonzo, Kasyoka; Viswanathan, Vignesh; Durairaja, Archana; Voigt, Anne; Yarali, Ayse

    2017-05-01

    Avoiding associatively learned predictors of danger is crucial for survival. Aversive memories can, however, become counter-adaptive when they are overly generalized to harmless cues and contexts. In a fruit fly odor-electric shock associative memory paradigm, we found that learned avoidance lost its specificity for the trained odor and became general to novel odors within a day of training. We discuss the possible neural circuit mechanisms of this effect and highlight the parallelism to over-generalization of learned fear behavior after an incubation period in rodents and humans, with due relevance for post-traumatic stress disorder. © 2017. Published by The Company of Biologists Ltd.

  9. Highly stabilized partially premixed flames of propane in a concentric flow conical nozzle burner with coflow

    KAUST Repository

    Elbaz, Ayman M.

    2018-01-11

    Partially premixed turbulent flames with non-homogeneous jet of propane were generated in a concentric flow conical nozzle burner in order to investigate the effect of the coflow on the stability and flame structure. The flame stability is first mapped and then high-speed stereoscopic particle image velocimetry, SPIV, plus OH planar laser-induced fluorescence, OH-PLIF, measurements were conducted on a subset of four flames. The jet equivalence ratio Φ = 2, Jet exit Reynolds number Re = 10,000, and degree of premixing are kept constant for the selected flames, while the coflow velocity, Uc, is progressively changed from 0 to 15 m/s. The results showed that the flame is stable between two extinction limits of mixture inhomogeneity, and the optimum stability is obtained at certain degree of mixture inhomogeneity. Increasing Φ, increases the span between these two extinction limits, while these limits converge to a single point (corresponding to optimum mixture inhomogeneity) with increasing Re. Regardless the value of Φ, increasing the coflow velocity improves the flame stability. The correlation between recessed distance of the burner tubes and the fluctuation of the mixture fraction, Δξ, shows that at Δξ around 40% of the flammability limits leads to optimum flame stability. The time averaged SPIV results show that the coflow induces a big annular recirculation zone surrounds the jet flames. The size and the location of this zone is seen to be sensitive to Uc. However, the instantaneous images show the existence of a small vortical structure close to the shear layer, where the flame resides there in the case of no-coflow. These small vertical structures are seen playing a vital role in the flame structure, and increasing the flame corrugation close to the nozzle exit. Increasing the coflow velocity expands the central jet at the expense of the jet velocity, and drags the flame in the early flame regions towards the recirculation zone, where the flame tracks

  10. Effect of aging on hedonic appreciation of pleasant and unpleasant odors.

    Directory of Open Access Journals (Sweden)

    Pauline Joussain

    Full Text Available Does hedonic appreciation evolve differently for pleasant odors and unpleasant odors during normal aging? To answer this question we combined psychophysics and electro-encephalographic recordings in young and old adults. A first study showed that pleasant odorants (but not unpleasant ones were rated as less pleasant by old adults. A second study validated this decrease in hedonic appreciation for agreeable odors and further showed that smelling these odorants decreased beta event-related synchronization in aged participants. In conclusion, the study offers new insights into the evolution of odor hedonic perception during normal aging, highlighting for the first time a change in processing pleasant odors.

  11. Polyacrylonitrile Separator for High-Performance Aluminum Batteries with Improved Interface Stability.

    Science.gov (United States)

    Elia, Giuseppe Antonio; Ducros, Jean-Baptiste; Sotta, Dane; Delhorbe, Virginie; Brun, Agnès; Marquardt, Krystan; Hahn, Robert

    2017-11-08

    Herein we report, for the first time, an overall evaluation of commercially available battery separators to be used for aluminum batteries, revealing that most of them are not stable in the highly reactive 1-ethyl-3-methylimidazolium chloride:aluminum trichloride (EMIMCl:AlCl 3 ) electrolyte conventionally employed in rechargeable aluminum batteries. Subsequently, a novel highly stable polyacrylonitrile (PAN) separator obtained by the electrospinning technique for application in high-performance aluminum batteries has been prepared. The developed PAN separator has been fully characterized in terms of morphology, thermal stability, and air permeability, revealing its suitability as a separator for battery applications. Furthermore, extremely good compatibility and improved aluminum interface stability in the highly reactive EMIMCl:AlCl 3 electrolyte were discovered. The use of the PAN separator strongly affects the aluminum dissolution/deposition process, leading to a quite homogeneous deposition compared to that of a glass fiber separator. Finally, the applicability of the PAN separator has been demonstrated in aluminum/graphite cells. The electrochemical tests evidence the full compatibility of the PAN separator in aluminum cells. Furthermore, the aluminum/graphite cells employing the PAN separator are characterized by a slightly higher delivered capacity compared to those employing glass fiber separators, confirming the superior characteristics of the PAN separator as a more reliable separator for the emerging aluminum battery technology.

  12. High-strength and high-RRR Al-Ni alloy for aluminum-stabilized superconductor

    CERN Document Server

    Wada, K; Sakamoto, H; Yamamoto, A; Makida, Y

    2000-01-01

    The precipitation type aluminum alloys have excellent performance as the increasing rate in electric resistivity with additives in the precipitation state is considerably low, compared to that of the aluminum alloy with additives in the solid-solution state. It is possible to enhance the mechanical strength without remarkable degradation in residual resistivity ratio (RRR) by increasing content of selected additive elements. Nickel is the suitable additive element because it has very low solubility in aluminum and low increasing rate in electric resistivity, and furthermore, nickel and aluminum form intermetallic compounds which effectively resist the motion of dislocations. First, Al-0.1wt%Ni alloy was developed for the ATLAS thin superconducting solenoid. This alloy achieved high yield strength of 79 MPa (R.T.) and 117 MPa (4.2 K) with high RRR of 490 after cold working of 21% in area reduction. These highly balanced properties could not be achieved with previously developed solid-solution aluminum alloys. ...

  13. The effect of high pressures on the yoghurt from milk with the stabilizer

    International Nuclear Information System (INIS)

    Reps, A; Jankowska, A; Wisniewska, K

    2008-01-01

    The effect of high pressures on the microbiological and physio-chemical properties of yoghurt was investigated. The best results were obtained when the yoghurt was manufactured from milk with the addition of MYO 752 stabilizer (starch, gelatin, pectin) selected from 10 stabilizers. Yoghurt manufactured with the addition of 0, 6% MYO 752 stabilizer was processed at the pressure of 400-600 MPa/15 min. in the range of 50 MPa. Pressurization caused a total reduction of number of Lactobacillus delbrueckii ssp. Bulgaricus and reduced the number of Streptococcus thermophilus by 1-2 orders of magnitude. Pressurized and non-pressurized yoghurts characterized of a homogenous consistency and typical plain yoghurt taste. The decrease of the number of living bacteria was observed in yoghurts during the storage. The acidity of pressurized yoghurts remained on the some level at the temperature of 4 0 C and 20 0 C. The more intensive antibacterial activity of microflora was observed in yoghurts storaged at 20 0 C in comparison with yoghurts storaged at 4 0 C. Disadvantageous changes of the pressurized yoghurts consistency were not found. The taste and aroma of yoghurts remained without any changes

  14. Long term stability of paraoxonase-1 and high-density lipoprotein in human serum

    Directory of Open Access Journals (Sweden)

    Beekhof Piet K

    2012-05-01

    Full Text Available Abstract Background Paraoxonase-1 (PON1 is an enzyme with numerous functions and receives an increasing interest in clinical and epidemiological studies. Sometimes samples are stored for longer periods at a certain temperature. Therefore the stability of PON1 activity must be checked and retained upon storage for longer periods. Results In this study the stability of PON1 activity has been tested in human serum samples during storage up to 12 months at 3 commonly used temperatures, -20°C, -70°C and −196°C. It was found that the stability of the PON1 activity is constant during 12 months of storage at −70°C and −196°C. Storage at −20°C resulted in a small but statistically significant decrease after 6 months to about 94% of its original value. Nonetheless, the rank order between the samples at T = 0 and 12 months remained the same. The same temperature dependence was found for the associated high-density lipoprotein. Conclusions It can be concluded that −70°C is the right temperature for storage to maintain the PON1 activity for at least one year. Storage at a lower temperature in liquid nitrogen (−196°C is not necessary.

  15. The effect of high pressures on the yoghurt from milk with the stabilizer

    Science.gov (United States)

    Reps, A.; Jankowska, A.; Wiśniewska, K.

    2008-07-01

    The effect of high pressures on the microbiological and physio-chemical properties of yoghurt was investigated. The best results were obtained when the yoghurt was manufactured from milk with the addition of MYO 752 stabilizer (starch, gelatin, pectin) selected from 10 stabilizers. Yoghurt manufactured with the addition of 0, 6% MYO 752 stabilizer was processed at the pressure of 400-600 MPa/15 min. in the range of 50 MPa. Pressurization caused a total reduction of number of Lactobacillus delbrueckii ssp. Bulgaricus and reduced the number of Streptococcus thermophilus by 1-2 orders of magnitude. Pressurized and non-pressurized yoghurts characterized of a homogenous consistency and typical plain yoghurt taste. The decrease of the number of living bacteria was observed in yoghurts during the storage. The acidity of pressurized yoghurts remained on the some level at the temperature of 4°C and 20°C. The more intensive antibacterial activity of microflora was observed in yoghurts storaged at 20°C in comparison with yoghurts storaged at 4°C. Disadvantageous changes of the pressurized yoghurts consistency were not found. The taste and aroma of yoghurts remained without any changes.

  16. The effect of high pressures on the yoghurt from milk with the stabilizer

    Energy Technology Data Exchange (ETDEWEB)

    Reps, A; Jankowska, A; Wisniewska, K [Chair of Food Biotechnology, University of Warmia and Mazury, Heweliusza str 1., 10-724 Olsztyn (Poland)], E-mail: arnold.reps@uwm.edu.pl

    2008-07-15

    The effect of high pressures on the microbiological and physio-chemical properties of yoghurt was investigated. The best results were obtained when the yoghurt was manufactured from milk with the addition of MYO 752 stabilizer (starch, gelatin, pectin) selected from 10 stabilizers. Yoghurt manufactured with the addition of 0, 6% MYO 752 stabilizer was processed at the pressure of 400-600 MPa/15 min. in the range of 50 MPa. Pressurization caused a total reduction of number of Lactobacillus delbrueckii ssp. Bulgaricus and reduced the number of Streptococcus thermophilus by 1-2 orders of magnitude. Pressurized and non-pressurized yoghurts characterized of a homogenous consistency and typical plain yoghurt taste. The decrease of the number of living bacteria was observed in yoghurts during the storage. The acidity of pressurized yoghurts remained on the some level at the temperature of 4{sup 0}C and 20{sup 0}C. The more intensive antibacterial activity of microflora was observed in yoghurts storaged at 20{sup 0}C in comparison with yoghurts storaged at 4{sup 0}C. Disadvantageous changes of the pressurized yoghurts consistency were not found. The taste and aroma of yoghurts remained without any changes.

  17. Initial mechanical stability of cementless highly-porous titanium tibial components

    Energy Technology Data Exchange (ETDEWEB)

    Stone, Timothy Brandon [Los Alamos National Laboratory; Amer, Luke D [Los Alamos National Laboratory; Warren, Christopher P [Los Alamos National Laboratory; Cornwell, Phillip [Los Alamos National Laboratory; Meneghini, R Michael [UNIV OF CONNECTICUT HEALTH CENTER

    2008-01-01

    Cementless fixation in total knee replacement has seen limited use since reports of early failure surfaced in the late 80s and early 90s. However the emergence of improved biomaterials, particularly porous titanium and tantalum, has led to a renewed interest in developing a cementless tibial component to enhance long-term survivorship of the implants. Cement is commonly employed to minimize micromotion in new implants but represents a weak interface between the implant and bone. The elimination of cement and application of these new biomaterials, which theoretically provide improved stability and ultimate osseointegration, would likely result in greater knee replacement success. Additionally, the removal of cement from the procedure would help minimize surgical durations and get rid of the time needed for curing, thereby the chance of infection. The purpose of this biomechanical study was twofold. The first goal was to assess whether vibration analysis techniques can be used to evaluate and characterize initial mechanical stability of cementless implants more accurately than the traditional method of micromotion determination, which employs linear variable differential transducers (LVDTs). Second, an evaluative study was performed to determine the comparative mechanical stability of five designs of cementless tibial components under mechanical loading designed to simulate in vivo forces. The test groups will include a cemented Triathlon Keeled baseplate control group, three different 2-peg cementless baseplates with smooth, mid, and high roughnesses and a 4-peg cement/ess baseplate with mid-roughness.

  18. Mixed models for selection of Jatropha progenies with high adaptability and yield stability in Brazilian regions.

    Science.gov (United States)

    Teodoro, P E; Bhering, L L; Costa, R D; Rocha, R B; Laviola, B G

    2016-08-19

    The aim of this study was to estimate genetic parameters via mixed models and simultaneously to select Jatropha progenies grown in three regions of Brazil that meet high adaptability and stability. From a previous phenotypic selection, three progeny tests were installed in 2008 in the municipalities of Planaltina-DF (Midwest), Nova Porteirinha-MG (Southeast), and Pelotas-RS (South). We evaluated 18 families of half-sib in a randomized block design with three replications. Genetic parameters were estimated using restricted maximum likelihood/best linear unbiased prediction. Selection was based on the harmonic mean of the relative performance of genetic values method in three strategies considering: 1) performance in each environment (with interaction effect); 2) performance in each environment (with interaction effect); and 3) simultaneous selection for grain yield, stability and adaptability. Accuracy obtained (91%) reveals excellent experimental quality and consequently safety and credibility in the selection of superior progenies for grain yield. The gain with the selection of the best five progenies was more than 20%, regardless of the selection strategy. Thus, based on the three selection strategies used in this study, the progenies 4, 11, and 3 (selected in all environments and the mean environment and by adaptability and phenotypic stability methods) are the most suitable for growing in the three regions evaluated.

  19. Insights into the structural stability of Bax from molecular dynamics simulations at high temperatures

    Science.gov (United States)

    Rosas-Trigueros, Jorge Luis; Correa-Basurto, José; Guadalupe Benítez-Cardoza, Claudia; Zamorano-Carrillo, Absalom

    2011-01-01

    Bax is a member of the Bcl-2 protein family that participates in mitochondrion-mediated apoptosis. In the early stages of the apoptotic pathway, this protein migrates from the cytosol to the outer mitochondrial membrane, where it is inserted and usually oligomerizes, making cytochrome c-compatible pores. Although several cellular and structural studies have been reported, a description of the stability of Bax at the molecular level remains elusive. This article reports molecular dynamics simulations of monomeric Bax at 300, 400, and 500 K, focusing on the most relevant structural changes and relating them to biological experimental results. Bax gradually loses its α-helices when it is submitted to high temperatures, yet it maintains its globular conformation. The resistance of Bax to adopt an extended conformation could be due to several interactions that were found to be responsible for maintaining the structural stability of this protein. Among these interactions, we found salt bridges, hydrophobic interactions, and hydrogen bonds. Remarkably, salt bridges were the most relevant to prevent the elongation of the structure. In addition, the analysis of our results suggests which conformational movements are implicated in the activation/oligomerization of Bax. This atomistic description might have important implications for understanding the functionality and stability of Bax in vitro as well as within the cellular environment. PMID:21936009

  20. Thermo chemical stability of cadmium sulfide nanoparticles under intense pulsed light irradiation and high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Colorado, H.A., E-mail: hcoloradolopera@ucla.edu [Materials Science and Engineering Department, University of California, Los Angeles, CA 90095 (United States); Universidad de Antioquia, Mechanical Engineering, Medellin (Colombia); Dhage, S.R. [International Advanced Research Center for Powder Metallurgy and New Materials (ARCI), Hyderabad 500005 (India); Hahn, H.T. [Materials Science and Engineering Department, University of California, Los Angeles, CA 90095 (United States); Mechanical and Aerospace Engineering Department, University of California, Los Angeles (United States)

    2011-09-15

    Highlights: > In this paper is about the thermochemical stability of CdS nanoparticles under Intense Pulsed Light (IPL) irradiation. > After few irradiation shots over the nano-particles, CdS pillars appeared without phase transformation. > No oxidation was observed during the treatment process. > CdS nanoparticles are thermally stable until around 400 deg. C and 600 deg. C for air and argon atmospheres respectively. > It has been studied and demonstrated the stability of CdS nanoparticles under intense pulsed light and under high temperature conditions. - Abstract: Thermo chemical stability of CdS nanoparticles under an Intense Pulsed Light from a xenon flash lamp and high temperature X-ray Diffraction (XRD) were investigated. The CdS nanoparticles were obtained with a chemical bath method. The CdSO{sub 4} (0.16 M) solution was added to an NH{sub 3} (7.5 M) solution under constant stirring. Afterwards, a thiourea (0.6 M) solution was added. The bath temperature and pH were maintained at 65 deg. C and 10, respectively and the mixture was stirred constantly until a solid precipitate of yellow CdS was produced. Its microstructure was investigated with Scanning Electron Microscopy, and its electronic properties were determined by UV-visible and Photo luminescence Spectroscopy. The microstructure of the sintered CdS nanoparticles, obtained the high temperature XRD, was investigated with EDAX and X-ray micro Tomography. In addition, high temperature XRD and Themogravimetric Analysis tests were conducted over the samples. The CdS nanoparticles' crystallinity increased with the irradiation exposure and they were thermally stable until 600 deg. C in argon atmosphere. However new phases start to appear after annealing at 400 deg. C for 30 min in air atmosphere. The main contribution of this paper was to investigate the stability of CdS nanoparticles under intense light and high temperature conditions. It was found that the number of irradiation shots conducted with the

  1. Aggregate stability by the "high energy moisture characteristic" method in an oxisol under differentiated management

    Directory of Open Access Journals (Sweden)

    Érika Andressa da Silva

    2014-10-01

    Full Text Available Studies testing the High Energy Moisture Characteristic (HEMC technique in tropical soils are still incipient. By this method, the effects of different management systems can be evaluated. This study investigated the aggregation state of an Oxisol under coffee with Brachiaria between crop rows and surface-applied gypsum rates using HEMC. Soil in an experimental area in the Upper São Francisco region, Minas Gerais, was studied at depths of 0.05 and 0.20 m in coffee rows. The treatments consisted of 0, 7, and 28 Mg ha-1 of agricultural gypsum rates distributed on the soil surface of the coffee rows, between which Brachiaria was grown and periodically cut, and compared with a treatment without Brachiaria between coffee rows and no gypsum application. To determine the aggregation state using the HEMC method, soil aggregates were placed in a Büchner funnel (500 mL and wetted using a peristaltic pump with a volumetric syringe. The wetting was applied increasingly at two pre-set speeds: slow (2 mm h-1 and fast (100 mm h-1. Once saturated, the aggregates were exposed to a gradually increasing tension by the displacement of a water column (varying from 0 to 30 cm to obtain the moisture retention curve [M = f (Ψ ], underlying the calculation of the stability parameters: modal suction, volume of drainable pores (VDP, stability index (slow and fast, VDP ratio, and stability ratio. The HEMC method conferred sensitivity in quantifying the aggregate stability parameters, and independent of whether gypsum was used, the soil managed with Brachiaria between the coffee rows, with regular cuts discharged in the crop row direction, exhibited a decreased susceptibility to disaggregation.

  2. AMisfit Theory of Spontaneous Conscious Odor Perception (MITSCOP: reflections on the role and function of odor memory in everyday life.

    Directory of Open Access Journals (Sweden)

    Egon P Köster

    2014-02-01

    Full Text Available Our senses have developed as an answer to the world we live in (Gibson, 1966 and so have the forms of memory that accompany them. All senses serve different purposes and do so in different ways. In vision, where orientation and object recognition are important, memory is strongly linked to identification. In olfaction, the guardian of vital functions such as breathing and food ingestion, perhaps the most important (and least noticed and researched role of odor memory is to help us not to notice the well-known odors or flavors in our everyday surroundings, but to react immediately to the unexpected ones. At the same time it provides us with a feeling of safety when our expectancies are met. All this happens without any smelling intention or conscious knowledge of our expectations. Identification by odor naming is not involved in this and people are notoriously bad at it. Odors are usually best identified via the episodic memory of the situation in which they once occurred. Spontaneous conscious odor perception normally only occurs in situations where attention is demanded, either because the inhaled air or the food smell is particularly good or particularly bad and people search for its source or because people want to actively enjoy the healthiness and pleasantness of their surroundings or food. Odor memory is concerned with novelty detection rather than with recollection of odors. In this paper, these points are illustrated with experimental results and their consequences for doing ecologically valid odor memory research are drawn. Furthermore, suggestions for ecologically valid research on everyday odor memory and some illustrative examples are given.

  3. Odor tracking in sharks is reduced under future ocean acidification conditions.

    Science.gov (United States)

    Dixson, Danielle L; Jennings, Ashley R; Atema, Jelle; Munday, Philip L

    2015-04-01

    Recent studies show that ocean acidification impairs sensory functions and alters the behavior of teleost fishes. If sharks and other elasmobranchs are similarly affected, this could have significant consequences for marine ecosystems globally. Here, we show that projected future CO2 levels impair odor tracking behavior of the smooth dogfish (Mustelus canis). Adult M. canis were held for 5 days in a current-day control (405 ± 26 μatm) and mid (741 ± 22 μatm) or high CO2 (1064 ± 17 μatm) treatments consistent with the projections for the year 2100 on a 'business as usual' scenario. Both control and mid CO2 -treated individuals maintained normal odor tracking behavior, whereas high CO2 -treated sharks significantly avoided the odor cues indicative of food. Control sharks spent >60% of their time in the water stream containing the food stimulus, but this value fell below 15% in high CO2 -treated sharks. In addition, sharks treated under mid and high CO2 conditions reduced attack behavior compared to the control individuals. Our findings show that shark feeding could be affected by changes in seawater chemistry projected for the end of this century. Understanding the effects of ocean acidification on critical behaviors, such as prey tracking in large predators, can help determine the potential impacts of future ocean acidification on ecosystem function. © 2014 John Wiley & Sons Ltd.

  4. Edge-emitting lasers based on coupled large optical cavity with high beam stability

    Science.gov (United States)

    Serin, A.; Gordeev, N.; Payusov, A.; Shernyakov, Y.; Kalyuzhnyy, y.; Mintairov, S.; Maximov, M.

    2017-11-01

    In this paper we present a study on temperature and current stability of far-field patterns of lasers based on the coupled large optical cavity (CLOC) concept. Previously it has been shown that the CLOC structures allows effective suppressing of high-order mode lasing in broadened waveguides. For the first time we report on transverse single-mode emission from the CLOC lasers with 4.8 μm thick waveguide. Using broadened waveguide allowed us to reduce the divergence of the far-field patterns down to 14° in continuous-wave (CW) regime. Far-field patterns proved to be insensitive to current and temperature changes.

  5. High level model predictive control for plug-and-play process control with stability guaranty

    DEFF Research Database (Denmark)

    Michelsen, Axel Gottlieb; Stoustrup, Jakob

    2010-01-01

    In this paper a method for designing a stabilizing high level model predictive controller for a hierarchical plug- and-play process is presented. This is achieved by abstracting the lower layers of the controller structure as low order models with uncertainty and by using a robust model predictive...... controller for generating the references for these. A simulation example, in which the actuators in a process control system are changed, is reported to show the potential of this approach for plug and play process control....

  6. Stability of fluxon motion in long Josephson junctions at high bias

    DEFF Research Database (Denmark)

    Pagano, S.; Sørensen, Mads Peter; Christiansen, Peter Leth

    1988-01-01

    In long Josephson junctions the motion of fluxons is revealed by the existence of current steps, zero-field steps, in the current-voltage characteristics. In this paper we investigate the stability of the fluxon motion when high values of the current bias are involved. The investigation is carried...... dissipations and of the junction length on the switching-current value is investigated. A simple boundary model is able to describe, for junctions of overlap geometry, the qualitative dependence of the switching current on the system parameters....

  7. Research for High Stability frequency Oscillator to improve phase noise of Superconducting Acceleratory

    International Nuclear Information System (INIS)

    Na, G. H.; Ko, Y. W.; Hong, S. P.; Park, J. H.; Kim, K. Y.; Lee, T. G.; Lee, J. H.

    2010-04-01

    In this study, a UHF oscillator is High Stability frequency Oscillator to improve phase noise of Superconducting Acceleratory. The main blocks of PLL have been designed including voltage controlled oscillator, phase frequency detector, and charge pump. The LC VCO has been used for a better noise property and low-power design. The source and drain junctions of PMOS transistors are used as the varactor diodes. The Analog Device has been used for the external pre-scaler and N-divider to divide VCO frequency and a third order RC filter is designed for the loop filter. The contents are internal and external study, methodology and results, achievement and contribution and others

  8. High-Throughput Screening of the Asymmetric Decarboxylative Alkylation Reaction of Enolate-Stabilized Enol Carbonates

    KAUST Repository

    Stoltz, Brian

    2010-06-14

    The use of high-throughput screening allowed for the optimization of reaction conditions for the palladium-catalyzed asymmetric decarboxylative alkylation reaction of enolate-stabilized enol carbonates. Changing to a non-polar reaction solvent and to an electron-deficient PHOX derivative as ligand from our standard reaction conditions improved the enantioselectivity for the alkylation of a ketal-protected,1,3-diketone-derived enol carbonate from 28% ee to 84% ee. Similar improvements in enantioselectivity were seen for a β-keto-ester derived- and an α-phenyl cyclohexanone-derived enol carbonate.

  9. Ultrathin MoO2 nanosheets with good thermal stability and high conductivity

    Directory of Open Access Journals (Sweden)

    Enqiang Pu

    2017-02-01

    Full Text Available Exploration and development of new two-dimensional (2D materials with good stability and remarkable physical properties have become the research hotspots. We report for the first time the monodispersity of ultrathin MoO2 nanosheets have been synthesized through an improved chemical vapor deposition (CVD method using only molybdenum trioxide as precursor. The grown MoO2 nanosheets have an average thickness of ∼ 5 to 10 nm and exhibit good crystal-quality. Temperature-dependent Raman spectra show that the ultrathin MoO2 nanosheets have high thermal stability up to 503 K. In addition, the first order temperature coefficients of the MoO2 characteristic Raman modes O1–Mo and O2–Mo were firstly found to be -1.91×10-2 and -3.94×10-2 cm−1/K, respectively. Two-probe electrical measurements show that the as-fabricated ultrathin MoO2 nanosheets devices preserve a high electrical conductivity in ambient conditions, reaching up to 200 - 475 S/cm. The exceptionally high conductivity of individual MoO2 nanosheet is ascribed to the unique crystal structure. Our results demonstrate that the ultrathin MoO2 nanosheets show great potential applications in constructing new integrated electronic devices and systems.

  10. Facile Synthesis Polyethylene Glycol Coated Magnetite Nanoparticles for High Colloidal Stability

    Directory of Open Access Journals (Sweden)

    Mun Foong Tai

    2016-01-01

    Full Text Available Polyethylene glycol (PEG is one of the most frequently used synthetic polymers for surface modifications of magnetite nanoparticles (MNPs to provide a new opportunity for constructing high colloidal stability. Herein, a facile in situ coprecipitation technique is described for the synthesis of PEG coated MNPs using ammonium hydroxide as the precipitating agent. The structure and morphology of the prepared PEG coated MNPs samples were characterized by Fourier transform infrared (FTIR spectroscopy, X-ray spectroscopy, thermogravimetric analysis (TGA, and the high resolution transmission electron microscopy (HRTEM. In this study, all samples demonstrated hydrodynamic size in the range of 32 to 43 nm with narrow size distribution. In addition, the magnetic properties of resultant samples were investigated using a vibrating sample magnetometer (VSM to reveal the superparamagnetic behaviour with saturation magnetization. The saturation magnetization of PEG coated MNPs samples was in the range of 63 to 66 emu/g at 300 K. Interestingly, it was found that 1.0 g of PEG coated MNPs exhibited high colloidal stability in a basic solution (pH = 10 and nitrile (NBR latex up to 21 days as compared to the unmodified MNPs during the sedimentation test.

  11. Data on blueberry peroxidase kinetic characterization and stability towards thermal and high pressure processing

    Directory of Open Access Journals (Sweden)

    Netsanet Shiferaw Terefe

    2017-08-01

    Full Text Available The data presented in this article are related to a research article entitled ‘Thermal and high pressure inactivation kinetics of blueberry peroxidase’ (Terefe et al., 2017 [1]. In this article, we report original data on the activity of partially purified blueberry peroxidase at different concentrations of hydrogen peroxide and phenlylenediamine as substrates and the effects of thermal and high pressure processing on the activity of the enzyme. Data on the stability of the enzyme during thermal (at temperatures ranging from 40 to 80 °C and combined thermal-high pressure processing (100–690 MPa, 30–90 °C are included in this report. The data are presented in this format in order to facilitate comparison with data from other researchers and allow statistical analyses and modeling by others in the field.

  12. The Next Generation of High-Speed Dynamic Stability Wind Tunnel Testing (Invited)

    Science.gov (United States)

    Tomek, Deborah M.; Sewall, William G.; Mason, Stan E.; Szchur, Bill W. A.

    2006-01-01

    Throughout industry, accurate measurement and modeling of dynamic derivative data at high-speed conditions has been an ongoing challenge. The expansion of flight envelopes and non-conventional vehicle design has greatly increased the demand for accurate prediction and modeling of vehicle dynamic behavior. With these issues in mind, NASA Langley Research Center (LaRC) embarked on the development and shakedown of a high-speed dynamic stability test technique that addresses the longstanding problem of accurately measuring dynamic derivatives outside the low-speed regime. The new test technique was built upon legacy technology, replacing an antiquated forced oscillation system, and greatly expanding the capabilities beyond classic forced oscillation testing at both low and high speeds. The modern system is capable of providing a snapshot of dynamic behavior over a periodic cycle for varying frequencies, not just a damping derivative term at a single frequency.

  13. Evaluation of γ-radiation on green tea odor volatiles

    International Nuclear Information System (INIS)

    Fanaro, G.B.; Duarte, R.C.; Araujo, M.M.; Purgatto, E.; Villavicencio, A.L.C.H.

    2011-01-01

    The aim of this study was to evaluate the gamma radiation effects on green tea odor volatiles in green tea at doses of 0, 5, 10, 15 and 20 kGy. The volatile organic compounds were extracted by hydrodistillation and analyzed by GC/MS. The green tea had a large influence on radiation effects, increasing the identified volatiles in relation to control samples. The dose of 10 kGy was responsible to form the majority of new odor compounds following by 5 and 20 kGy. However, the dose of 5 kGy was the dose that degraded the majority of volatiles in non-irradiated samples, following by 20 kGy. The dose of 15 kGy showed has no effect on odor volatiles. The gamma radiation, at dose up to 20 kGy, showed statistically no difference between irradiated and non irradiated green tea on odors compounds.

  14. Evaluation of {gamma}-radiation on green tea odor volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, G.B., E-mail: gbfanaro@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Duarte, R.C., E-mail: renatocduarte@yahoo.com.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Araujo, M.M., E-mail: mmozeika@yahoo.co [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Purgatto, E., E-mail: epurgatt@usp.b [Universidade de Sao Paulo-Faculdade de Ciencias Farmaceuticas, FCF/USP, Departamento de Alimentos e Nutricao Experimental, Av. Prof. Lineu Prestes, 580 Bloco 14, 05508-900, Sao Paulo, SP (Brazil); Villavicencio, A.L.C.H., E-mail: villavic@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil)

    2011-01-15

    The aim of this study was to evaluate the gamma radiation effects on green tea odor volatiles in green tea at doses of 0, 5, 10, 15 and 20 kGy. The volatile organic compounds were extracted by hydrodistillation and analyzed by GC/MS. The green tea had a large influence on radiation effects, increasing the identified volatiles in relation to control samples. The dose of 10 kGy was responsible to form the majority of new odor compounds following by 5 and 20 kGy. However, the dose of 5 kGy was the dose that degraded the majority of volatiles in non-irradiated samples, following by 20 kGy. The dose of 15 kGy showed has no effect on odor volatiles. The gamma radiation, at dose up to 20 kGy, showed statistically no difference between irradiated and non irradiated green tea on odors compounds.

  15. Hazardous Odor Recognition by CMAC Based Neural Networks

    Directory of Open Access Journals (Sweden)

    Bekir Karlık

    2009-09-01

    Full Text Available Electronic noses are being developed as systems for the automated detection and classification of odors, vapors, and gases. Artificial neural networks (ANNs have been used to analyze complex data and to recognize patterns, and have shown promising results in recognition of volatile compounds and odors in electronic nose applications. When an ANN is combined with a sensor array, the number of detectable chemicals is generally greater than the number of unique sensor types. The odor sensing system should be extended to new areas since its standard style where the output pattern from multiple sensors with partially overlapped specificity is recognized by a neural network or multivariate analysis. This paper describes the design, implementation and performance evaluations of the application developed for hazardous odor recognition using Cerebellar Model Articulation Controller (CMAC based neural networks.

  16. Molecular determinants of odorant receptor function in insects

    Indian Academy of Sciences (India)

    Supplementary figure 1. Locations of motifs in the 11 Drosophila phenol odor receptors. Phenol-specific motifs are indicated in green, and family-wide motifs are indicated in red. Transmembrane domains are indicated as bars on top of sequence.

  17. Origin, Analytical Characterization, and Use of Human Odor in Forensics.

    Science.gov (United States)

    Cuzuel, Vincent; Cognon, Guillaume; Rivals, Isabelle; Sauleau, Charles; Heulard, François; Thiébaut, Didier; Vial, Jérôme

    2017-03-01

    Developing a strategy to characterize the odor prints of individuals should be relevant to support identification obtained using dogs in courts of justice. This article proposes an overview of the techniques used for the forensic profiling of human odor. After reviewing the origin of human odor-both genetic and physiological-the different analytical steps from sample collection to statistical data processing are presented. The first challenge is the collection of odor, whether by direct sampling with polymer patches, cotton gauze, etc., or indirect sampling with devices like Scent Transfer Unit. Then, analytical techniques are presented. Analyses are commonly performed with gas chromatography coupled with mass spectrometry. As they yield large amounts of data, advanced statistical tools are needed to provide efficient and reliable data processing, which is essential to give more probative value to information. © 2017 American Academy of Forensic Sciences.

  18. Highly-stabilized power supply for synchrotron accelerators. High speed, low ripple power supply

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kenji [Osaka Univ., Ibaraki (Japan). Research Center for Nuclear Physics; Kumada, Masayuki; Fukami, Kenji; Koseki, Shoichiro; Kubo, Hiroshi; Kanazawa, Toru

    1997-02-01

    In synchrotron accelerators, in order to utilize high energy beam effectively, those are operated by repeating acceleration and taking-out at short period. In order to accelerate by maintaining beam track stable, the tracking performance with the error less than 10{sup -3} in the follow-up of current is required for the power supply. Further, in order to maintain the intensity and uniformity of beam when it is taken out, very low ripple is required for output current. The power supply having such characteristics has been developed, and applied to the HIMAC and the SPring-8. As the examples of the application of synchrotrons, the accelerators for medical treatment and the generation of synchrotron radiation are described. As to the power supply for the deflection magnets and quadrupole magnets of synchrotron accelerators, the specifications of the main power supply, the method of reducing ripple, the method of improving tracking, and active filter control are reported. As to the test results, the measurement of current ripple and tracking error is shown. The lowering of ripple was enabled by common mode filter and the symmetrical connection of electromagnets, and high speed response was realized by the compensation for delay with active filter. (K.I.)

  19. Development of high-strength and high-RRR aluminum-stabilized superconductor for the ATLAS thin solenoid

    CERN Document Server

    Wada, K; Sakamoto, H; Shimada, T; Nagasu, Y; Inoue, I H; Tsunoda, K; Endo, S; Yamamoto, A; Makida, Y; Tanaka, K; Doi, Y; Kondo, T

    2000-01-01

    The ATLAS central solenoid magnet is being constructed to provide a magnetic field of 2 Tesla in the central tracking part of the ATLAS detector at the LHC. Since the solenoid coil is placed in front of the liquid-argon electromagnetic calorimeter, the solenoid coil must be as thin (and transparent) as possible. The high-strength and high- RRR aluminum-stabilized superconductor is a key technology for the solenoid to be thinnest while keeping its stability. This has been developed with an alloy of 0.1 wt% nickel addition to 5N pure aluminum and with the subsequent mechanical cold working of 21% in area reduction. A yield strength of 110 MPa at 4.2 K has been realized keeping a residual resistivity ratio (RRR) of 590, after a heat treatment corresponding to coil curing at 130 degrees C for 15 hrs. This paper describes the optimization of the fabrication process and characteristics of the developed conductor. (8 refs).

  20. Geometrical Nonlinear Aeroelastic Stability Analysis of a Composite High-Aspect-Ratio Wing

    Directory of Open Access Journals (Sweden)

    Chang Chuan Xie

    2008-01-01

    Full Text Available A composite high-aspect-ratio wing of a high-altitude long-endurance (HALE aircraft was modeled with FEM by MSC/NASTRAN, and the nonlinear static equilibrium state is calculated under design load with follower force effect, but without load redistribution. Assuming the little vibration amplitude of the wing around the static equilibrium state, the system is linearized and the natural frequencies and mode shapes of the deformed structure are obtained. Planar doublet lattice method is used to calculate unsteady aerodynamics in frequency domain ignoring the bending effect of the deflected wing. And then, the aeroelastic stability analysis of the system under a given load condition is successively carried out. Comparing with the linear results, the nonlinear displacement of the wing tip is higher. The results indicate that the critical nonlinear flutter is of the flap/chordwise bending type because of the chordwise bending having quite a large torsion component, with low critical speed and slowly growing damping, which dose not appear in the linear analysis. Furthermore, it is shown that the variation of the nonlinear flutter speed depends on the scale of the load and on the chordwise bending frequency. The research work indicates that, for the very flexible HALE aircraft, the nonlinear aeroelastic stability is very important, and should be considered in the design progress. Using present FEM software as the structure solver (e.g. MSC/NASTRAN, and the unsteady aerodynamic code, the nonlinear aeroelastic stability margin of a complex system other than a simple beam model can be determined.

  1. Analysis of the structural stability of the smectite submitted to high pressures and temperatures

    International Nuclear Information System (INIS)

    Alabarse, Frederico Gil

    2009-10-01

    The thermal stability of bentonite is of particular interest for containment barrier in nuclear waste disposal facilities. However, very little is known about the stability of smectite (principal component of bentonite) under high-pressure and high-temperature conditions (HPHT). The objective of this work was to investigate the stability of the smectite structure under HP-HT conditions. The HP-HT experiments were performed on toroidal chambers (TC) with pressure up 7.7 GPa and temperatures of 1000 deg C. The samples were characterized by X-ray diffraction after the HP-HT processing. Furthermore, one sample from the original material was analyzed using Fourier transformed infra-red (FTIR) in situ measurements on a diamond anvil cell (DAC) in experiments up to 12 GPa. The original sample of bentonite, calcium dioctahedral montmorillonite with small fraction of quartz, was characterized by FTIR, XRD, X-ray fluorescence (XRF), scanning electron microscopy (SEM), surface area, thermogravimetric analysis (TGA) and differential thermal analysis (DTA). In the experiment performed using the DAC up to 12 GPa, the FTIR in situ measurements analysis showed that the smectite structure is stable with a reversible deformation in the Si-O bond and that the smectite did not loose water. Experiments performed in TC at 7.7 GPa of pressure and 250 deg C of temperature, during 3.5 h showed, after analysis by XRD and FTIR, that the smectite structure is stable and did not loose water. Experiments performed in TC at 7.7 GPa of pressure and 1000 deg C of temperature, during 3.5 h showed, after analysis by XRD and SEM, the transformation of bentonite to the mineral assemblage: Coesite, Quartz, Kyanite and Pyrope. (author)

  2. MIB-producing cyanobacteria (Planktothrix sp.) in a drinking water reservoir: distribution and odor producing potential.

    Science.gov (United States)

    Su, Ming; Yu, Jianwei; Zhang, Junzhi; Chen, Hui; An, Wei; Vogt, Rolf D; Andersen, Tom; Jia, Dongmin; Wang, Jingshi; Yang, Min

    2015-01-01

    The production of odorant 2-methylisoborneol (MIB) in water bodies by Planktothrix sp. have not been understood very well. Through a four-year investigation in Miyun Reservoir, a huge mesotrophic drinking water reservoir known to have the MIB episodes, we found that the Planktothrix sp. bloomed during September and October causing the high levels of MIB in the reservoir. The concentration of MIB and the biomass of MIB-producing cyanobacteria Planktothrix were measured (n = 887) at different sites and depths during different seasons. The results indicated that the shallow region of the reservoir is the major habitat for Planktothrix sp. due to that the light is able to penetrate down to the relatively high concentrations of nutrients close to the sediments. Quantile regression analysis between Planktothrix biomass and MIB concentration shows that the risk of MIB exceeding the odor threshold (15 ng L⁻¹) in water was as high as 90% when the Planktothrix density was more than 4.0 × 10⁵ cells L⁻¹, while the risk was reduced to 10% when the Planktothrix density remained below 1.6 × 10⁴ cells L⁻¹. This study will improve the understanding of the environmental behaviors of Planktothrix sp., and can provide useful information for better management of drinking water lakes/reservoirs experiencing the taste and odor (T&O) problems caused by deep living cyanobacterial species.

  3. The use of dispersion modeling to determine the feasibility of vegetative environmental buffers (VEBS) at controlling odor dispersion

    Science.gov (United States)

    Weber, Eric E.

    decreased downwind concentrations from a control scenario. This shows that VEBs have the potential to act as an odor control option for CAFOs. This study also found that a forecast method that integrated numerical weather prediction into dispersion models could be developed to forecast areas of high concentration. Model-forecasted dispersion trends had a high spatial correlation with collected concentrations for days when the facility was emitting. This shows that dispersion models can accurately predict high concentration areas using forecasted weather data. The information provided by this study may ultimately prove useful for this particular facility and others and may help to lower tensions with surrounding residents.

  4. Brain-immune interaction accompanying odor-evoked autobiographic memory.

    Science.gov (United States)

    Matsunaga, Masahiro; Bai, Yu; Yamakawa, Kaori; Toyama, Asako; Kashiwagi, Mitsuyoshi; Fukuda, Kazuyuki; Oshida, Akiko; Sanada, Kazue; Fukuyama, Seisuke; Shinoda, Jun; Yamada, Jitsuhiro; Sadato, Norihiro; Ohira, Hideki

    2013-01-01

    The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET) recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC) and precuneus/posterior cingulate cortex (PCC) were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions.

  5. Brain–Immune Interaction Accompanying Odor-Evoked Autobiographic Memory

    Science.gov (United States)

    Matsunaga, Masahiro; Bai, Yu; Yamakawa, Kaori; Toyama, Asako; Kashiwagi, Mitsuyoshi; Fukuda, Kazuyuki; Oshida, Akiko; Sanada, Kazue; Fukuyama, Seisuke; Shinoda, Jun; Yamada, Jitsuhiro; Sadato, Norihiro; Ohira, Hideki

    2013-01-01

    The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET) recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC) and precuneus/posterior cingulate cortex (PCC) were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions. PMID:23977312

  6. Brain-immune interaction accompanying odor-evoked autobiographic memory.

    Directory of Open Access Journals (Sweden)

    Masahiro Matsunaga

    Full Text Available The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α and interferon-γ (IFN-γ, were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC and precuneus/posterior cingulate cortex (PCC were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions.

  7. Simultaneous removal of multiple odorants from source water suffering from septic and musty odors: Verification in a full-scale water treatment plant with ozonation.

    Science.gov (United States)

    Guo, Qingyuan; Yang, Kai; Yu, Jianwei; Wang, Chunmiao; Wen, Xiaodong; Zhang, Liping; Yang, Min; Xia, Ping; Zhang, Dong

    2016-09-01

    Ozonation is known to be very effective in the removal of odorants from source water. However, it is not known if ozonation is effective in the removal of multiple odorants causing different types of odors. In this study, the removal performance for odors and odorants were evaluated in a Water Treatment Plant (WTP), which was equipped with coagulation, sedimentation, ozonation, biological activated carbon (BAC) filtration, sand filtration, and chlorination in succession and located in the downstream of the Huangpu (HP) River, over the period from April, 2014 to April, 2015. Flavor profile analysis (FPA) results showed that the source water was constantly associated with septic and musty odors. Geosmin and 2-MIB, with an average OAV of 4.54 and 1.38, respectively, were the major odorants for musty odor, while bis(2-chloroisopropyl) ether, DEDS and DMDS with an average OAV of 2.35, 1.65 and 0.78, respectively, might be responsible for the septic odor. While the musty odor could be removed effectively through the combination of ozonation and BAC, the septic odor and associated odorants required further treatment with sand filtration and chlorination for complete removal. It is clear that the advanced treatment process was effective for the treatment of source water containing complicated odorants. It should be noted that the sedimentation process needs careful management because release of odorants may occur during the treatment. The result of this study will be helpful for the mitigation of odors in WTP using source waters suffering from complicated odor problems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. High-stability 48-core bendable and movable optical cable for FAST telescope optical transmission system

    Science.gov (United States)

    Liu, Hongfei; Pan, Gaofeng; Lin, Zhong; Liu, Cheng; Zhu, Wenbai; Nan, Rendong; Li, Chunsheng; Gao, Guanjun; Luo, Wenyong; Jin, Chengjin; Song, Jinyou

    2017-11-01

    The construction of FAST telescope was completed in Guizhou province of China in September 2016, and a kind of novel high-stability 48-core bendable and movable optical cable was developed and applied in analog data optical transmission system of FAST. Novel structure and selective material of this optical cable ensure high stability of optical power in the process of cables round-trip motion when telescope is tracking a radio source. The 105 times bend and stretch accelerated experiment for this optical cable was implemented, and real-time optical and RF signal power fluctuation were measured. The physical structure of optical cables after 105 times round-trip motion is in good condition; the real-time optical power attenuation fluctuation is smaller than 0.044 dB; the real-time RF power fluctuation is smaller than 0.12 dB. The optical cable developed in this letter meets the requirement of FAST and has been applied in FAST telescope.

  9. Magnetism and high magnetic-field-induced stability of alloy carbides in Fe-based materials.

    Science.gov (United States)

    Hou, T P; Wu, K M; Liu, W M; Peet, M J; Hulme-Smith, C N; Guo, L; Zhuang, L

    2018-02-14

    Understanding the nature of the magnetic-field-induced precipitation behaviors represents a major step forward towards unravelling the real nature of interesting phenomena in Fe-based alloys and especially towards solving the key materials problem for the development of fusion energy. Experimental results indicate that the applied high magnetic field effectively promotes the precipitation of M 23 C 6 carbides. We build an integrated method, which breaks through the limitations of zero temperature and zero external field, to concentrate on the dependence of the stability induced by the magnetic effect, excluding the thermal effect. We investigate the intimate relationship between the external field and the origins of various magnetics structural characteristics, which are derived from the interactions among the various Wyckoff sites of iron atoms, antiparallel spin of chromium and Fe-C bond distances. The high-magnetic-field-induced exchange coupling increases with the strength of the external field, which then causes an increase in the parallel magnetic moment. The stability of the alloy carbide M 23 C 6 is more dependent on external field effects than thermal effects, whereas that of M 2 C, M 3 C and M 7 C 3 is mainly determined by thermal effects.

  10. An Improved Methodology for Multidimensional High-Throughput Preformulation Characterization of Protein Conformational Stability

    Science.gov (United States)

    Maddux, Nathaniel R.; Rosen, Ilan T.; Hu, Lei; Olsen, Christopher M.; Volkin, David B.; Middaugh, C. Russell

    2013-01-01

    The Empirical Phase Diagram (EPD) technique is a vector-based multidimensional analysis method for summarizing large data sets from a variety of biophysical techniques. It can be used to provide comprehensive preformulation characterization of a macromolecule’s higher-order structural integrity and conformational stability. In its most common mode, it represents a type of stimulus-response diagram using environmental variables such as temperature, pH, and ionic strength as the stimulus, with alterations in macromolecular structure being the response. Until now EPD analysis has not been available in a high throughput mode because of the large number of experimental techniques and environmental stressor/stabilizer variables typically employed. A new instrument has been developed that combines circular dichroism, UV-absorbance, fluorescence spectroscopy and light scattering in a single unit with a 6-position temperature controlled cuvette turret. Using this multifunctional instrument and a new software system we have generated EPDs for four model proteins. Results confirm the reproducibility of the apparent phase boundaries and protein behavior within the boundaries. This new approach permits two EPDs to be generated per day using only 0.5 mg of protein per EPD. Thus, the new methodology generates reproducible EPDs in high-throughput mode, and represents the next step in making such determinations more routine. PMID:22447621

  11. An improved methodology for multidimensional high-throughput preformulation characterization of protein conformational stability.

    Science.gov (United States)

    Maddux, Nathaniel R; Rosen, Ilan T; Hu, Lei; Olsen, Christopher M; Volkin, David B; Middaugh, C Russell

    2012-06-01

    The empirical phase diagram (EPD) technique is a vector-based multidimensional analysis method for summarizing large data sets from a variety of biophysical techniques. It can be used to provide comprehensive preformulation characterization of a macromolecule's higher-order structural integrity and conformational stability. In its most common mode, it represents a type of stimulus-response diagram using environmental variables such as temperature, pH, and ionic strength as the stimulus, with alterations in macromolecular structure being the response. Until now, EPD analysis has not been available in a high-throughput mode because of the large number of experimental techniques and environmental stressor/stabilizer variables typically employed. A new instrument has been developed that combines circular dichroism, ultraviolet absorbance, fluorescence spectroscopy, and light scattering in a single unit with a six-position, temperature-controlled cuvette turret. Using this multifunctional instrument and a new software system, we have generated EPDs for four model proteins. Results confirm the reproducibility of the apparent phase boundaries and protein behavior within the boundaries. This new approach permits two EPDs to be generated per day using only 0.5 mg of protein per EPD. Thus, the new methodology generates reproducible EPDs in high-throughput mode and represents the next step in making such determinations more routine. Copyright © 2012 Wiley Periodicals, Inc.

  12. High vacuum synthesis and ambient stability of bottom-up graphene nanoribbons.

    Science.gov (United States)

    Fairbrother, Andrew; Sanchez-Valencia, Juan-Ramon; Lauber, Beat; Shorubalko, Ivan; Ruffieux, Pascal; Hintermann, Tobias; Fasel, Roman

    2017-02-23

    Carbon-based nanomaterials such as graphene are at a crucial point in application development, and their promising potential, which has been demonstrated at the laboratory scale, must be translated to an industrial setting for commercialization. Graphene nanoribbons in particular overcome one limitation of graphene in some electronic applications because they exhibit a sizeable bandgap. However, synthesis of bottom-up graphene nanoribbons is most commonly performed under ultra-high vacuum conditions, which are costly and difficult to maintain in a manufacturing environment. Additionally, little is known about the stability of graphene nanoribbons under ambient conditions or during transfer to technologically relevant substrates and subsequent device processing. This work addresses some of these challenges, first by synthesizing bottom-up graphene nanoribbons under easily obtained high vacuum conditions and identifying water and oxygen as the residual gases responsible for interfering with proper coupling during the polymerization step. And second, by using Raman spectroscopy to probe the stability of nanoribbons during storage under ambient conditions, after transfer to arbitrary substrates, and after fabrication of field-effect transistor devices, which shows structurally intact nanoribbons even several months after synthesis. These findings demonstrate the potential of graphene nanoribbon technologies by addressing some limitations which might arise in their commercialization.

  13. On the sensitivity of dimensional stability of high density polyethylene on heating rate

    Directory of Open Access Journals (Sweden)

    2007-02-01

    Full Text Available Although high density polyethylene (HDPE is one of the most widely used industrial polymers, its application compared to its potential has been limited because of its low dimensional stability particularly at high temperature. Dilatometry test is considered as a method for examining thermal dimensional stability (TDS of the material. In spite of the importance of simulation of TDS of HDPE during dilatometry test it has not been paid attention by other investigators. Thus the main goal of this research is concentrated on simulation of TDS of HDPE. Also it has been tried to validate the simulation results and practical experiments. For this purpose the standard dilatometry test was done on the HDPE speci­mens. Secant coefficient of linear thermal expansion was computed from the test. Then by considering boundary conditions and material properties, dilatometry test has been simulated at different heating rates and the thermal strain versus temper­ature was calculated. The results showed that the simulation results and practical experiments were very close together.

  14. Thermocyclic stability of candidate Seebeck coefficient standard reference materials at high temperature

    Science.gov (United States)

    Martin, Joshua; Wong-Ng, Winnie; Caillat, Thierry; Yonenaga, I.; Green, Martin L.

    2014-05-01

    The Seebeck coefficient is the most widely measured property specific to thermoelectric materials. There is currently no consensus on measurement protocols, and researchers employ a variety of techniques to measure the Seebeck coefficient. The implementation of standardized measurement protocols and the use of reliable Seebeck Coefficient Standard Reference Materials (SRMs®) will allow the accurate interlaboratory comparison and validation of materials data, thereby accelerating the development and commercialization of more efficient thermoelectric materials and devices. To enable members of the thermoelectric materials community the means to calibrate Seebeck coefficient measurement equipment, NIST certified SRM® 3451 "Low Temperature Seebeck Coefficient Standard (10 K to 390 K)". Due to different practical requirements in instrumentation, sample contact methodology, and thermal stability, a complementary SRM® is required for the high temperature regime (300 K to 900 K). The principal requirement of a SRM® for the Seebeck coefficient at high temperature is thermocyclic stability. We therefore characterized the thermocyclic behavior of the Seebeck coefficient for a series of candidate materials: constantan, p-type single crystal SiGe, and p-type polycrystalline SiGe, by measuring the temperature dependence of the Seebeck coefficient as a function of 10 sequential thermal cycles, between 300 K and 900 K. We employed multiple regression analysis to interpolate and analyze the thermocyclic variability in the measurement curves.

  15. High stabilized power sources for bending and quadrupole magnets of TRISTAN project

    International Nuclear Information System (INIS)

    Kumagai, Noritaka; Ogawa, Shin-ichi; Koseki, Shoichiro; Nagasaka, Saburo.

    1984-01-01

    In the power source exciting the electro-magnets for the electron ring of TRISTAN project being advanced in the National Laboratory for High Energy Physics, the performance as strict as 10 -4 is required for its long hour stability and pulsating rate of DC output current in order to maintain beam stably. For satisfying such specification, the structure of power source using a high accuracy current detector, an active filter and so on was adopted. In order to verify the performance of this power source, the trial manufacture was carried out independently, and the test combining with actual magnets was performed. As the results, it was confirmed that the power source had the sufficient performance about its output stability, pulsating rate, current-following property and so on. At present, the manufacture of 80 actual power sources is in progress. In this paper, the power source system and the results of performance test of the power source made for trial are reported. The power sources are divide into B power sources for exciting deflecting electro-magnets and Q power sources for exciting quadrupole electro-magnets. (Kako, I.)

  16. Long term stability of Li-S batteries using high concentration lithium nitrate electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Brian D.; Carino, Emily V.; Connell, Justin G.; Han, Kee Sung; Cao, Ruiguo; Chen, Junzheng; Zheng, Jianming; Li, Qiuyan; Mueller, Karl T.; Henderson, Wesley A.; Zhang, Ji-Guang

    2017-10-01

    The lithium-sulfur (Li-S) battery is a very promising candidate for the next generation of energy storage systems required for electrical vehicles and grid energy storage applications due to its very high theoretical specific energy (2500 W h kg(-1)). However, low Coulombic efficiency (CE) during repeated Li metal plating/stripping has severely limited the practical application of rechargeable Li-S batteries. In this work, a new electrolyte system based on a high concentration of LiNO3 in diglyme (G2) solvent is developed which enables an exceptionally high CE for Li metal plating/stripping and thus high stability of the Li anode in the sulfur-containing electrolyte. The tailoring of electrolyte properties for the Li anode has proven to be a highly successful strategy for improving the capacity retention and cycle life of Li-S batteries. This electrolyte provides a CE of greater than 99% for over 200 cycles of Li plating/stripping. In contrast, the Li anode cycles for less than 35 cycles (with a high CE) in the state-of-the-art 1 M LiTFSI + 0.3 M LiNO3 in 1,3-dioxolane: 1,2-dimethoxyethane (DOL:DME) electrolyte under the same conditions. The stable Li anode enabled by the new electrolyte may accelerate the applications of high energy density Li-S batteries in both electrical vehicles and large-scale grid energy storage markets.

  17. High current 66 kV tests on high stability PFN discharge capacitors for CERN LHC

    CERN Document Server

    Barnes, M J

    1999-01-01

    The European Laboratory for Particle Physics (CERN) is constructing a Large Hadron Collider (LHC) to be installed in an existing 27 km circumference tunnel. The LHC will be equipped with fast pulsed magnet systems for injecting two counter-rotating hadron beams. Two pulsed systems, of 4 magnets and 4 pulse forming networks (PFNs) each, are required for this purpose. TRIUMF will build and test 5 resonant charging power supplies (RCPS) and nine PFNs and the associated thyratron switch units as part of the Canadian contribution to CERN LHC. Failures in the PFN capacitors may lead to incorrect beam deflections that may in turn damage LHC components. For this reason the reliability of the capacitors must be exceptionally high. Hence sample PFN capacitors were purchased and tested. The test procedure included discharging the PFN capacitors from 66 kV, into a 10.1 Ohm resistance, for 500,000 cycles, at a frequency of approximately 1 Hz. Subsequently the PFN capacitors were discharged from 66 kV into a 2.7 Ohm resist...

  18. Regulation of tentacle length in snails by odor concentration.

    Science.gov (United States)

    Nikitin, E S; Zakharov, I S; Balaban, P M

    2006-01-01

    The upper tentacle of the snail, bearing the olfactory organ, produces complex movements when the snail explores a new environment. Tentacle trajectories were reconstructed in the presence and absence of odors using two simultaneous video recordings. Reconstructions showed that in the absence of odor, snails constantly scanned the surrounding space with the extended tentacles. Presentation of an odor elicited rapid flexion, independent of the odor concentration, accompanied by concentration-dependent tentacle contractions. Activation of identified motoneuron MtC3 is known to elicit tentacle contraction. Recordings made in semi-intact preparations showed that the dynamics and duration of the spike activity of MtC3 produced in response to odors correlated with the degree of tentacle contraction in response to odors. These data suggest that the central motoneuron MtC3, which triggers tentacle contraction, is involved in controlling the margins of the scanning field. Slow contraction or extension of the tentacle, associated with the level of MtC3 activity, may operate to tune the snail's investigative behavior to the conditions of the sensory environment.

  19. Variable selection based cotton bollworm odor spectroscopic detection

    Science.gov (United States)

    Lü, Chengxu; Gai, Shasha; Luo, Min; Zhao, Bo

    2016-10-01

    Aiming at rapid automatic pest detection based efficient and targeting pesticide application and shooting the trouble of reflectance spectral signal covered and attenuated by the solid plant, the possibility of near infrared spectroscopy (NIRS) detection on cotton bollworm odor is studied. Three cotton bollworm odor samples and 3 blank air gas samples were prepared. Different concentrations of cotton bollworm odor were prepared by mixing the above gas samples, resulting a calibration group of 62 samples and a validation group of 31 samples. Spectral collection system includes light source, optical fiber, sample chamber, spectrometer. Spectra were pretreated by baseline correction, modeled with partial least squares (PLS), and optimized by genetic algorithm (GA) and competitive adaptive reweighted sampling (CARS). Minor counts differences are found among spectra of different cotton bollworm odor concentrations. PLS model of all the variables was built presenting RMSEV of 14 and RV2 of 0.89, its theory basis is insect volatilizes specific odor, including pheromone and allelochemics, which are used for intra-specific and inter-specific communication and could be detected by NIR spectroscopy. 28 sensitive variables are selected by GA, presenting the model performance of RMSEV of 14 and RV2 of 0.90. Comparably, 8 sensitive variables are selected by CARS, presenting the model performance of RMSEV of 13 and RV2 of 0.92. CARS model employs only 1.5% variables presenting smaller error than that of all variable. Odor gas based NIR technique shows the potential for cotton bollworm detection.

  20. Giant pandas use odor cues to discriminate kin from nonkin.

    Science.gov (United States)

    Gilad, Oranit; Swaisgood, Ronald R; Owen, Megan A; Zhou, Xiaoping

    2016-08-01

    Sociality is an important factor in both the mechanism and function of kin recognition, yet it is little explored in solitary species. While there may be future opportunities for nepotistic functions of kin discrimination among solitary species, the ability to discriminate kin from nonkin may still have important roles in social regulation. The solitary giant panda Ailuropoda melanoleuca offers a good model system to explore kin discrimination in a solitary mammal. As kin discrimination in many other mammals is olfactorily mediated, we investigated whether giant pandas are able to discriminate odor cues from daughters even after months and years of separation. Our results indicate that giant pandas are capable of discriminating between kin and nonkin using odor cues available in urine and body odor. Daughters preferentially investigated the odors of unrelated adult female pandas over the odors of their mothers, and mothers spent more time investigating the odors of unrelated age-matched female pandas over those from their daughters. Because these studies were conducted months or years after the mother-daughter period of dependency ended, it is still unclear what mechanism is used for recognition. Long-term olfactory memories and phenotype matching should both be considered, and further studies are required for such determination.

  1. Canine detection odor signatures for mine-related explosives

    Science.gov (United States)

    Johnston, James M.; Williams, Marc; Waggoner, L. Paul; Edge, Cindy C.; Dugan, Regina E.; Hallowell, Susan F.

    1998-09-01

    Dogs are capable of detecting and discriminating a number of compounds constituting a complex odor. However, they use only a few of these to recognize a substance. The focus of this research is to determine the compounds dogs learn to use in recognizing explosives used in land mines. This is accomplished by training dogs under behavioral laboratory conditions to respond differentially on separate levers to (1) blank air, (2) a target odor such as an explosive, and (3) all other odors (non-target odors). Vapor samples are generated by a serial dilution vapor generator whose operation and output is characterized by GC/MS. Once dogs learn this three-lever discrimination, testing sessions are conducted containing a number of probe trials in which vapor from constituent compounds is presented. Which lever the dogs respond to on these probe trials indicates whether they can smell the compound at all (blank lever) or whether it smells like the target odor (e.g., the explosive) or like something else. This method was conducted using TNT and C-4. The data show the dogs' reactions to each of the constituent compounds tested for each explosive. Analysis of these data reveal the canine detection odor signature for these explosives.

  2. PLASMA THERMAL BARRIER COATINGS BASED ON ZIRCONIUM DIOXIDE WITH HIGH THERMAL STABILITY

    Directory of Open Access Journals (Sweden)

    O. G. Devoino

    2015-01-01

    Full Text Available The paper presents optimization of  processes for obtaining maximum content of tetragonal phase in the initial material and thermal barrier coatings (TBC based on zirconium dioxide and hafnium oxide.  Results of the investigations on phase composition of oxide HfO2 – ZrO2 – Y2O3  system have been given in the paper. The system represents  a microstructure which is similar to  zirconia dioxide and  transformed for its application at 1300 °C. The paper explains a mechanism of hafnium oxide influence on formation of the given microstructure. The research methodology has been based on complex metallography, X – ray diffraction and electron microscopic investigations of  structural elements of the composite plasma coating HfO2 – ZrO2 – Y2O system.In order to stabilize zirconium dioxide  dopant oxide should not only have an appropriate size of  metal ion, but also form a solid solution with the zirconia. This condition severely limits the number of possible stabilizers. In fact, such stabilization is possible only with the help of rare earth oxides (Y2O3, Yb2O3, CeO2, HfO2. Chemical purity of the applied materials plays a significant role for obtaining high-quality thermal barrier coatings. Hafnium oxide has been selected as powder for thermal barrier coatings instead of zirconium dioxide due to their similarities in structural modification, grating, chemical and physical properties and its high temperature structural transformations. It has been established that plasma thermal barrier HfO2 – ZrO2 – Y2O3 coatings consist of  one tetragonal phase. This phase is equivalent to a non-equilibrium tetragonal t' phase in the “zirconium dioxide stabilized with yttrium oxide” system. Affinity of  Hf+4 and Zr+4 cations leads to the formation of identical metastable phases during rapid quenching.

  3. High-power microwave generation from a frequency-stabilized virtual cathode source

    International Nuclear Information System (INIS)

    Fazio, M.V.; Hoeberling, R.F.; Kinross-Wright, J.

    1988-01-01

    The evolution of virtual cathode based high-power microwave-source technology has been directed primarily toward achieving higher peak-power levels. As peak powers in excess of 10 GW have been reported, attention has begun to focus on techniques for producing a more frequency- and phase-stable virtual cathode source. Free-running virtual cathode microwave sources characteristically exhibit bandwidths in a single pulse of tens of percent, which makes them unsuitable for many applications such as power sources for phased array antennas and microwave linear accelerators. Presented here are results of an experimental approach utilizing a high-Q, resonant cavity surrounding the oscillating virtual cathode to achieve frequency stabilization and repeatable narrow-band operation. A cylindrical cavity resonator is used with the microwave power being extracted radially through circumferential slot apertures into L-band waveguide

  4. Strontium Zirconate TBC Sprayed by a High Feed-Rate Water-Stabilized Plasma Torch

    Science.gov (United States)

    Ctibor, P.; Nevrla, B.; Cizek, J.; Lukac, F.

    2017-12-01

    A novel thermal barrier coating (TBC) material, strontium zirconate SrZrO3, was sprayed by a high feed-rate water-stabilized plasma torch WSP 500. Stainless steel coupons were used as substrates. Coatings with a thickness of about 1.2 mm were produced, whereas the substrates were preheated over 450 °C. The torch worked at 150 kW power and was able to spray SrZrO3 with a high spray rate over 10 kg per hour. Microstructure and microhardness, phase composition, adhesion, thermal conductivity and thermal expansion were evaluated. The coating has low thermal conductivity under 1 W/m K in the interval from room temperature up to 1200 °C. Its crystallite size is slightly over 400 nm and thermal expansion 12.3 µm K-1 in the similar temperature range.

  5. On the optical stability of high-resolution transmission electron microscopes.

    Science.gov (United States)

    Barthel, J; Thust, A

    2013-11-01

    In the recent two decades the technique of high-resolution transmission electron microscopy experienced an unprecedented progress through the introduction of hardware aberration correctors and by the improvement of the achievable resolution to the sub-Ångström level. The important aspect that aberration correction at a given resolution requires also a well defined amount of optical stability has received little attention so far. Therefore we investigate the qualification of a variety of high-resolution electron microscopes to maintain an aberration corrected optical state in terms of an optical lifetime. We develop a comprehensive statistical framework for the estimation of the optical lifetime and find remarkably low values between tens of seconds and a couple of minutes. Probability curves are introduced, which inform the operator about the chance to work still in the fully aberration corrected state. © 2013 Elsevier B.V. All rights reserved.

  6. Graded-Index Polymer Optical Fiber with High Thermal Stability of Bandwidth

    Science.gov (United States)

    Ishigure, Takaaki; Sato, Masataka; Nihei, Eisuke; Koike, Yasuhiro

    1998-07-01

    The development of the perfluorinated (PF) polymer based graded-index polymer optical fiber (GI POF) for high-speed data communication is described. It was experimentally confirmed that gigabit data transmission for 500 1000 m at 1.3 µm wavelength was achieved by the low-loss PF polymer based GI POF. The thermal stability of poly (methyl methacrylate) PMMA based GI POF is discussed. We selected several kinds of dopants that can maintain a high glass transition temperature (Tg) of the GI POF core. By using the newly selected dopants, we succeeded in maintaining the parabolic refractive index profile of GI POF with no degradation even at 85 to 90°C for more than 5000 h.

  7. High-stability polymerized liposomes composed of diene-containing phosphatidylcholine

    International Nuclear Information System (INIS)

    Anikin, A.V.; Chupin, V.V.; Anikin, M.V.; Serebrennikova, G.A.; Evstigneeva, R.P.

    1991-01-01

    A new able to polymerization phospholipid 1,2-di(tetsadeca-11,13 dienoyl)-sn-glycero-3-phosphocholine (DTDPC) was suggested. Easiness of DTDPC polymerization in liposomes content was coused by concentration of conjugated diene groups in biolayer centre thus decreasing probability of chain rupture and resulting in formation of high-molecular polymer. High stability of polymer liposomes was provided by extensive polymer chains, occurrence of branched network at the expense of two polymerizing groups in one lipid molecule and probable links between monolayers. DTDPC polymerization was shown to pass under mild conditions and resulted in formation of extremely stable membranes. Conformation-dynamic parameters of hydrophilic biolayer were preserved. The mentioned phosphatidylcholin can be applied in research and developments

  8. Thermal Stability of Hexamethyldisiloxane (MM for High-Temperature Organic Rankine Cycle (ORC

    Directory of Open Access Journals (Sweden)

    Markus Preißinger

    2016-03-01

    Full Text Available The design of efficient Organic Rankine Cycle (ORC units for the usage of industrial waste heat at high temperatures requires direct contact evaporators without intermediate thermal oil circuits. Therefore, the thermal stability of high-temperature working fluids gains importance. In this study, the thermal degradation of hexamethyldisiloxane (MM is investigated in an electrically heated tube. Qualitative results concerning remarks on degradation products as well as quantitative results like the annual degradation rate are presented. It is shown that MM is stable up to a temperature of 300 °C with annual degradation rates of less than 3.5%. Furthermore, the break of a silicon–carbon bond can be a main chemical reaction that influences the thermal degradation. Finally, it is discussed how the results may impact the future design of ORC units.

  9. Fabrication and characterization of poly (bisphenol A borate) with high thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shujuan [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Wang, Xiao [Department of Chemical Engineering, School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Jia, Beibei [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Jing, Xinli, E-mail: xljing@mail.xjtu.edu.cn [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi’an, 710049 (China)

    2017-01-15

    Highlights: • PBAB with excellent thermal resistance and high char yield was synthesized. • The chemical reaction of BPA with BA, and chemical structure of PBAB were studied. • PBAB show excellent thermal resistance in N{sub 2} and air atmospheres. • The thermal stability of PBAB is greatly influenced by boron content. • Boron oxide and boron carbide are formed during the pyrolysis of PBAB. - Abstract: In this work, poly (bisphenol A borate) (PBAB), which has excellent thermal resistance and a high char yield, was synthesized via a convenient A{sub 2} + B{sub 3} strategy by using bisphenol A (BPA) and boric acid (BA). The chemical reaction between BPA and BA and the chemical structure of PBAB were investigated. The results demonstrate that PBAB consists of aromatic, Ph–O–B and B–O–B structures, as well as a small number of boron hydroxyl groups and phenolic hydroxyl groups. The thermal properties of PBAB were studied by DMA and TGA. The results indicate that the glass transition temperature and char yield are gradually enhanced by increasing the boron content, where the char yield of PBAB at 800 °C in nitrogen (N{sub 2}) reaches up to 71.3%. It is of particular importance that PBAB show excellent thermal resistance in N{sub 2} and air atmospheres. By analysing the pyrolysis of PBAB, the high char yield of PBAB can be attributed to the formation of boron oxide and boron carbide at high temperatures, which reduced the release of volatile carbon dioxide and improved the thermal stability of the carbonization products. This study provides a new perspective on the design of novel boron-containing polymers and possesses significant potential for the improvement of the comprehensive performance of thermosetting resins to broaden their applicability in the field of advanced composites.

  10. Stability of norfloxacin in an extemporaneously prepared oral liquid.

    Science.gov (United States)

    Johnson, C E; Price, J; Hession, J M

    2001-04-01

    The stability of norfloxacin in an extemporaneously prepared suspension stored at room temperature and under refrigeration was studied over 56 days. A 20-mg/mL suspension was prepared from commercially available 400-mg norfloxacin tablets and equal amounts of Ora-Plus and strawberry syrup to make a final volume of 60 mL. Six identical samples of the suspension were prepared in amber plastic prescription bottles. Three were stored at room temperature (23-25 degrees C) and three under refrigeration (3-5 degrees C). Immediately after preparation and at 7, 14, 28, and 56 days, the samples were assayed in duplicate by stability-indicating high performance liquid chromatography. The samples were also inspected for color and odor changes and the pH of each sample was determined. At least 93% of the initial norfloxacin concentration remained throughout the 56-day study period. The color, odor, and pH of all of the samples did not change appreciably. An extemporaneously prepared suspension of norfloxacin 20 mg/mL was stable for at least 56 days when stored at either 23-25 or 3-5 degrees C.

  11. A General Odorant Background Affects the Coding of Pheromone Stimulus Intermittency in Specialist Olfactory Receptor Neurones

    Science.gov (United States)

    Rouyar, Angela; Party, Virginie; Prešern, Janez; Blejec, Andrej; Renou, Michel

    2011-01-01

    In nature the aerial trace of pheromone used by male moths to find a female appears as a train of discontinuous pulses separated by gaps among a complex odorant background constituted of plant volatiles. We investigated the effect of such background odor on behavior and coding of temporal parameters of pheromone pulse trains in the pheromone olfactory receptor neurons of Spodoptera littoralis. Effects of linalool background were tested by measuring walking behavior towards a source of pheromone. While velocity and orientation index did drop when linalool was turned on, both parameters recovered back to pre-background values after 40 s with linalool still present. Photo-ionization detector was used to characterize pulse delivery by our stimulator. The photo-ionization detector signal reached 71% of maximum amplitude at 50 ms pulses and followed the stimulus period at repetition rates up to 10 pulses/s. However, at high pulse rates the concentration of the odorant did not return to base level during inter-pulse intervals. Linalool decreased the intensity and shortened the response of receptor neurons to pulses. High contrast (>10 dB) in firing rate between pulses and inter-pulse intervals was observed for 1 and 4 pulses/s, both with and without background. Significantly more neurons followed the 4 pulses/s pattern when delivered over linalool; at the same time the information content was preserved almost to the control values. Rapid recovery of behavior shows that change of perceived intensity is more important than absolute stimulus intensity. While decreasing the response intensity, background odor preserved the temporal parameters of the specific signal. PMID:22028879

  12. Long term stability of Li-S batteries using high concentration lithium nitrate electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Brian DG; Carino, Emily V.; Connell, Justin G.; Han, Kee Sung; Cao, Ruiguo; Chen, Junzheng; Zheng, Jianming; Li, Qiuyan; Mueller, Karl T.; Henderson, Wesley A.; Zhang, Jiguang

    2017-10-01

    Lithium-sulfur (Li-S) battery is a very promising candidate for the next generation of energy storage systems required for electrical vehicles and grid energy storage applications due to its very high theoretical specific energy (2500 W h kg-1). However, the low coulombic efficiency (CE) during repeated Li plating/stripping of these processes have limited practical application of rechargeable Li-S batteries. In this work, a new electrolyte system based on high concentration of LiNO3 in diglyme solvent is developed which enables high CE of Li metal plating/stripping and high stability of Li anode in the sulfur containing electrolyte. Tailoring of electrolyte properties for the Li negative electrode has proven to be a successful strategy for improving the capacity retention and cycle life of Li-S batteries. This electrolyte provides a CE for Li plating/stripping of greater than 99% for over 200 cycles. In contrast, Li metal cycles for only less than 35 cycles at high CE in the standard 1 M LiTFSI + 2wt% LiNO3 in DOL:DME electrolyte under the same conditions. The stable Li metal anode enabled by the new electrolyte may accelerate the applications of high energy density Li-S batteries in both electrical vehicles and large-scale grid energy storage markets.

  13. Preservation of Essential Odor-Guided Behaviors and Odor-Based Reversal Learning after Targeting Adult Brain Serotonin Synthesis.

    Science.gov (United States)

    Carlson, Kaitlin S; Whitney, Meredith S; Gadziola, Marie A; Deneris, Evan S; Wesson, Daniel W

    2016-01-01

    The neurotransmitter serotonin (5-HT) is considered a powerful modulator of sensory system organization and function in a wide range of animals. The olfactory system is innervated by midbrain 5-HT neurons into both its primary and secondary odor-processing stages. Facilitated by this circuitry, 5-HT and its receptors modulate olfactory system function, including odor information input to the olfactory bulb. It is unknown, however, whether the olfactory system requires 5-HT for even its most basic behavioral functions. To address this question, we established a conditional genetic approach to specifically target adult brain tryptophan hydroxylase 2 ( Tph2 ), encoding the rate-limiting enzyme in brain 5-HT synthesis, and nearly eliminate 5-HT from the mouse forebrain. Using this novel model, we investigated the behavior of 5-HT-depleted mice during performance in an olfactory go/no-go task. Surprisingly, the near elimination of 5-HT from the forebrain, including the olfactory bulbs, had no detectable effect on the ability of mice to perform the odor-based task. Tph2 -targeted mice not only were able to learn the task, but also had levels of odor acuity similar to those of control mice when performing coarse odor discrimination. Both groups of mice spent similar amounts of time sampling odors during decision-making. Furthermore, odor reversal learning was identical between 5-HT-depleted and control mice. These results suggest that 5-HT neurotransmission is not necessary for the most essential aspects of olfaction, including odor learning, discrimination, and certain forms of cognitive flexibility.

  14. Direct NMR Monitoring of Phase Separation Behavior of Highly Supersaturated Nifedipine Solution Stabilized with Hypromellose Derivatives.

    Science.gov (United States)

    Ueda, Keisuke; Higashi, Kenjirou; Moribe, Kunikazu

    2017-07-03

    We investigated the phase separation behavior and maintenance mechanism of the supersaturated state of poorly water-soluble nifedipine (NIF) in hypromellose (HPMC) derivative solutions. Highly supersaturated NIF formed NIF-rich nanodroplets through phase separation from aqueous solution containing HPMC derivative. Dissolvable NIF concentration in the bulk water phase was limited by the phase separation of NIF from the aqueous solution. HPMC derivatives stabilized the NIF-rich nanodroplets and maintained the NIF supersaturation with phase-separated NIF for several hours. The size of the NIF-rich phase was different depending on the HPMC derivatives dissolved in aqueous solution, although the droplet size had no correlation with the time for which NIF supersaturation was maintained without NIF crystallization. HPMC acetate and HPMC acetate succinate (HPMC-AS) effectively maintained the NIF supersaturation containing phase-separated NIF compared with HPMC. Furthermore, HPMC-AS stabilized NIF supersaturation more effectively in acidic conditions. Solution 1 H NMR measurements of NIF-supersaturated solution revealed that HPMC derivatives distributed into the NIF-rich phase during the phase separation of NIF from the aqueous solution. The hydrophobicity of HPMC derivative strongly affected its distribution into the NIF-rich phase. Moreover, the distribution of HPMC-AS into the NIF-rich phase was promoted at lower pH due to the lower aqueous solubility of HPMC-AS. The distribution of a large amount of HPMC derivatives into NIF-rich phase induced the strong inhibition of NIF crystallization from the NIF-rich phase. Polymer distribution into the drug-rich phase directly monitored by solution NMR technique can be a useful index for the stabilization efficiency of drug-supersaturated solution containing a drug-rich phase.

  15. The role of equilibrium volume and magnetism on the stability of iron phases at high pressures.

    Science.gov (United States)

    Alnemrat, S; Hooper, J P; Vasiliev, I; Kiefer, B

    2014-01-29

    The present study provides new insights into the pressure dependence of magnetism by tracking the hybridization between crystal orbitals for pressures up to 600 GPa in the known hcp, bcc and fcc iron. The Birch-Murnaghan equation of state parameters are; bcc: V0 = 11.759 A(3)/atom, K0 = 177.72 GPa; hcp: V0 = 10.525 A(3)/atom, K0 = 295.16 GPa; and fcc: V0 = 10.682 A(3)/atom, K0 = 274.57 GPa. These parameters compare favorably with previous studies. Consistent with previous studies we find that the close-packed hcp and fcc phases are non-magnetic at pressures above 50 GPa and 60 GPa, respectively. The principal features of magnetism in iron are predicted to be invariant, at least up to ∼6% overextension of the equilibrium volume. Our results predict that magnetism for overextended fcc iron disappears via an intermediate spin state. This feature suggests that overextended lattices can be used to stabilize particular magnetic states. The analysis of the orbital hybridization shows that the magnetic bcc structure at high pressures is stabilized by splitting the majority and minority spin bands. The bcc phase is found to be magnetic at least up to 600 GPa; however, magnetism is insufficient to stabilize the bcc phase itself, at least at low temperatures. Finally, the analysis of the orbital contributions to the total energy provides evidence that non-magnetic hcp and fcc phases are likely more stable than bcc at core earth pressures.

  16. Viscosity and stability of ultra-high internal phase CO2-in-water foams stabilized with surfactants and nanoparticles with or without polyelectrolytes.

    Science.gov (United States)

    Xue, Zheng; Worthen, Andrew; Qajar, Ali; Robert, Isaiah; Bryant, Steven L; Huh, Chun; Prodanović, Maša; Johnston, Keith P

    2016-01-01

    To date, relatively few examples of ultra-high internal phase supercritical CO2-in-water foams (also referred to as macroemulsions) have been observed, despite interest in applications including "waterless" hydraulic fracturing in energy production. The viscosities and stabilities of foams up to 0.98 CO2 volume fraction were investigated in terms of foam bubble size, interfacial tension, and bulk and surface viscosity. The foams were stabilized with laurylamidopropyl betaine (LAPB) surfactant and silica nanoparticles (NPs), with and without partially hydrolyzed polyacrylamide (HPAM). For foams stabilized with mixture of LAPB and NPs, fine ∼70 μm bubbles and high viscosities on the order of 100 cP at>0.90 internal phase fraction were stabilized for hours to days. The surfactant reduces interfacial tension, and thus facilitates bubble generation and decreases the capillary pressure to reduce the drainage rate of the lamella. The LAPB, which is in the cationic protonated form, also attracts anionic NPs (and anionic HPAM in systems containing polymer) to the interface. The adsorbed NPs at the interface are shown to slow down Ostwald ripening (with or without polymer added) and increase foam stability. In systems with added HPAM, the increase in the bulk and surface viscosity of the aqueous phase further decreases the lamella drainage rate and inhibits coalescence of foams. Thus, the added polymer increases the foam viscosity by threefold. Scaling law analysis shows the viscosity of 0.90 volume fraction foams is inversely proportional to the bubble size. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. A new rapid high-throughput method for prediction of beer colloidal stability

    Czech Academy of Sciences Publication Activity Database

    Gabriel, P.; Sladký, P.; Sigler, Karel

    2016-01-01

    Roč. 122, č. 2 (2016), s. 304-309 ISSN 0046-9750 Institutional support: RVO:61388971 Keywords : colloidal stability * beer stabilization * forced aging test Subject RIV: GM - Food Processing Impact factor: 0.859, year: 2016

  18. Packing material formulation for odorous emission biofiltration.

    Science.gov (United States)

    Gaudin, François; Andres, Yves; Le Cloirec, Pierre

    2008-01-01

    In biological gas treatment, like biofiltration of volatile organic compounds or odorous substances, the microbial nutritional needs could be a key factor of the process. The aim of this work is to propose a new packing material able to provide the lacking nutrients. In the first part of this study, two kinds of material composed of calcium carbonate, an organic binder and two different nitrogen sources, ammonium phosphate and urea phosphate (UP), were compared. The new supports present bulk densities between 0.88 and 1.15g cm(-3), moisture retention capacities close to 50% and 70%, and water cohesion capacities greater than six months for the material with 20% binder. In the second part, oxygen consumption measurements in liquid experiments show that these packing materials could enhance bacterial growth compared to pine bark or pozzolan and have no inhibitory effect. The biodegradation of different substrates (sodium sulfide and ammonia) and the support colonization by the biomass were evaluated. Finally, UP 20 was chosen and tested in a hydrogen sulfide or ammoniac biofiltration process. This showed that, for H2S concentrations greater than 100mg m(-3), UP 20 has a real advantage over pine bark or pozzolan.

  19. Microbial survival and odor in laundry

    DEFF Research Database (Denmark)

    Jepsen, Signe Munk; Johansen, Charlotte; Stahnke, Louise Heller

    2001-01-01

    The survival and distribution of microflora during laundering at 30 or 40 degreesC in commercial U.S. and European Union (E.U.) detergents were determined in laboratory wash experiments. Four test strains-Staphylococcus epidermidis, S. aureus, Escherichia coli, and Pseudomonas aeruginosa-were eva......The survival and distribution of microflora during laundering at 30 or 40 degreesC in commercial U.S. and European Union (E.U.) detergents were determined in laboratory wash experiments. Four test strains-Staphylococcus epidermidis, S. aureus, Escherichia coli, and Pseudomonas aeruginosa......-were evaluated on cotton textile. A significant survival and transfer between textiles were found for all four test strains washed in E.U. and U.S. color detergents (without bleach), whereas no survival was observed in bleach-containing detergents. Gram-negative strains generally survived in greater numbers than...... Gram-positive strains. A greater survival was observed in U.S. detergents at U.S. conditions (30 degreesC, 12 min) than in E.U. detergents at E.U. conditions (40 degreesC, 30 min). The adhesion of odorants to cotton and polyester textiles during washing and drying was studied using six previously...

  20. The novel support structure design of high stability for space borne primary reflector

    Science.gov (United States)

    Yu, Fei; Ding, Lin; Tan, Ting; Pei, Jing-yang.; Zhao, Xue-min; Bai, Shao-jun

    2018-01-01

    The novel support structure design of high stability for space borne primary mirror is presented. The structure is supported by a ball head support rod, for statically determinate support of reflector. The ball head assembly includes the supporting rod, nesting, bushing and other important parts. The liner bushing of the resistant material is used to fit for ball head approximated with the reflector material, and then the bad impact of thermal mismatch could be minimized to minimum. In order to ensure that the structure of the support will not be damaged, the glue spots for limitation is added around the reflector, for position stability of reflector. Through analysis and calculation, it can be seen that the novel support structure would not transfer the external stresses to the reflector, and the external stresses usually result from thermal mismatch and assembly misalignment. The novel method is useful for solving the problem of the bad influence form thermal stress and assembly force. In this paper, the supporting structure is introduced and analyzed in detail. The simulation results show that the ball head support reflector works more stably.

  1. Ant Colony Optimization Analysis on Overall Stability of High Arch Dam Basis of Field Monitoring

    Directory of Open Access Journals (Sweden)

    Peng Lin

    2014-01-01

    Full Text Available A dam ant colony optimization (D-ACO analysis of the overall stability of high arch dams on complicated foundations is presented in this paper. A modified ant colony optimization (ACO model is proposed for obtaining dam concrete and rock mechanical parameters. A typical dam parameter feedback problem is proposed for nonlinear back-analysis numerical model based on field monitoring deformation and ACO. The basic principle of the proposed model is the establishment of the objective function of optimizing real concrete and rock mechanical parameter. The feedback analysis is then implemented with a modified ant colony algorithm. The algorithm performance is satisfactory, and the accuracy is verified. The m groups of feedback parameters, used to run a nonlinear FEM code, and the displacement and stress distribution are discussed. A feedback analysis of the deformation of the Lijiaxia arch dam and based on the modified ant colony optimization method is also conducted. By considering various material parameters obtained using different analysis methods, comparative analyses were conducted on dam displacements, stress distribution characteristics, and overall dam stability. The comparison results show that the proposal model can effectively solve for feedback multiple parameters of dam concrete and rock material and basically satisfy assessment requirements for geotechnical structural engineering discipline.

  2. High catalytic performance and stability of Pt/C using acetic acid functionalized carbon

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Jilei; Zhou, Yi; Gu, Jun; Yu, Tao [Eco-materials and Renewable Energy Research Center, Department of Physics and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Liu, Jianguo; Zou, Zhigang [Eco-materials and Renewable Energy Research Center, Department of Physics and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 (China)

    2009-12-01

    Carbon (Vulcan XC-72, Cobat Corp.) is pretreated using acetic acid (HAC) before the Pt deposition by microwave assisted glycol method. TEM and XRD results indicate that 3 nm Pt nano-particles are uniformly dispersed on the surface of modified XC-72. In order to examine the interaction between Pt nano-particles and carbon, Pt/C-HAC and commercial Pt/C (Johnson Matthey Corp.) are calcined at 500 C for 2 h under nitrogen atmosphere. The average Pt particle size of Pt/C-HAC after calcination is only 10-12 nm in diameter while commercial Pt particles grow up to 25-35 nm with a broad size distribution. Meanwhile, electrochemical studies of Pt/C-HAC reveal higher activity and stability for both methanol oxidation and oxygen reduction than that of Pt/C-JM. The pore structure and surface composition are investigated by BET and XPS, which implies that much microporous structure and carbonyl functional groups on carbon surface are obtained after HAC treatment. The high catalytic performance and stability might mainly be due to the strong interaction between Pt nano-particles and carbon by carbonyl functional groups. Therefore, HAC treatment is proved to be a facile and effective method for carbon as the support for Pt as fuel cell catalyst. (author)

  3. Stability limits of superhydrophobic longitudinal microgrooves in high Reynolds number turbulent flows

    Science.gov (United States)

    Rastegari, Amirreza; Akhavan, Rayhaneh

    2017-11-01

    The stability of the liquid/gas interfaces on SuperHydrophobic (SH) Longitudinal MicroGrooves (LMGs) in high Reynolds number turbulent flows of practical interest is investigated by analytical extrapolation of DNS results in turbulent channel flow at Reτ0 222 and 442 with SH LMGs at protrusion angle of θ = -30o . Given that the magnitude of pressure fluctuations in turbulent channel flow scales as prms+ √{ ln(Reτ) } , it is found that the stability limits of SH LMGs diminishes by factors of 4 when the Reynolds number of the base flow increases from Reτ0 200 of DNS to Reτ0 105 -106 of practical applications. For SH LMGs operating at Weber numbers of We+0 ≡ μuτ0 / σ 3 ×10-3 - 1.5 ×10-2 , corresponding to friction velocities of uτ0 0.2 - 1 m/s, this limits the size of stable LMGs to g+0 5 - 30 at Reτ0 105 and g+0 4 - 20 at Reτ0 106 , and the maximum drag reductions to DRmax 20 - 30 % at Reτ0 105 and DRmax 10 - 20 % at Reτ0 106 .

  4. Induced Unbalance as a Method for Improving the Dynamic Stability of High-Speed Turbochargers

    KAUST Repository

    Gordon Kirk, R.

    2011-01-01

    The high-speed diesel engine turbocharger is known to have subsynchronous vibrations for a wide speed range. The bearing fluid-film instability is the main source of the vibration. The nonlinear forces inside the bearings are causing the rotor to whirl in a limit cycle. This study presents a new method for improving the dynamic stability by inducing the turbocharger rotor unbalance in order to suppress the subsynchronous vibration. The finite-element model of the turbocharger with floating-ring bearings is numerically solved for the nonlinear time-transient response. Both compressor and turbine added unbalance are induced and the dynamic stability is computed. The turbocharger model with linearized floating-ring bearings is also solved for eigenvalues to predict the modes of instability. The linear analysis demonstrates that the forward whirling mode of the floating-ring at the compressor end also becomes unstable at the higher turbocharger speeds, in addition to the unstable forward conical and cylindrical modes. The numerical predictions are also compared to the former experimental results of a similar turbocharger. The results of the study show that the subsynchronous frequency amplitude of the dominant first mode is reduced when inducing either the compressor or the turbine unbalance at a certain level. © 2011 R. Gordon Kirk and Ali A. Alsaeed.

  5. Stability of high current diode under 100-nanosecond-pulse voltage

    International Nuclear Information System (INIS)

    Lai Dingguo; Qiu Aici; Zhang Yongmin; Huang Jianjun; Ren Shuqing; Yang Li

    2012-01-01

    Stability of high current diode under pulse voltage with 80 ns and 34 ns rise time was studied on the flash Ⅱ accelerator. Influence of rise time of diode voltage on startup time and cathode emission uniformity and repeatability of diode impedance was analyzed by comparing the experimental results with numerically simulated results, and the influence mechanism was discussed. The startup time of diode increases with the increasing of rise time of voltage, and the repeatability of diode impedance decreases. Discal plane cathode is prone to emit rays intensely in the center area, the time that plasma covers the surface of the cathode increases and the shielding effect has more impact on cathode emission according to the increase of rise time. Local intense emission on the cathode increases expansion speed of plasma and reduces the effective emission area. The stability of characteristic impedance of diode under a pulse voltage with slow rise time is decreased by the combined action of expansion speed of plasma and the effective emission area. (authors)

  6. Environmental stability of high-mobility indium-oxide based transparent electrodes

    Directory of Open Access Journals (Sweden)

    Thanaporn Tohsophon

    2015-11-01

    Full Text Available Large-scale deployment of a wide range of optoelectronic devices, including solar cells, critically depends on the long-term stability of their front electrodes. Here, we investigate the performance of Sn-doped In2O3 (ITO, H-doped In2O3 (IO:H, and Zn-doped In2O3 (IZO electrodes under damp heat (DH conditions (85 °C, 85% relative humidity. ITO, IO:H capped with ITO, and IZO show high stability with only 3%, 9%, and 13% sheet resistance (Rs degradation after 1000 h of DH, respectively. For uncapped IO:H, we find a 75% Rs degradation, due to losses in electron Hall mobility (μHall. We propose that this degradation results from chemisorbed OH- or H2O-related species in the film, which is confirmed by thermal desorption spectroscopy and x-ray photoelectron spectroscopy. While μHall strongly degrades during DH, the optical mobility (μoptical remains unchanged, indicating that the degradation mainly occurs at grain boundaries.

  7. Does Increased Coefficient of Friction of Highly Porous Metal Increase Initial Stability at the Acetabular Interface?

    Science.gov (United States)

    Goldman, Ashton H; Armstrong, Lucas C; Owen, John R; Wayne, Jennifer S; Jiranek, William A

    2016-03-01

    Highly porous metal acetabular components illustrate a decreased rate of aseptic loosening in short-term follow-up compared with previous registry data. This study compared the effect of component surface roughness at the bone-implant interface and the quality of the bone on initial pressfit stability. The null hypothesis is that a standard porous coated acetabular cup would show no difference in initial stability as compared with a highly porous acetabular cup when subjected to a bending moment. Second, would bone mineral density (BMD) be a significant variable under these test conditions. In a cadaveric model, acetabular cup micromotion was measured during a 1-time cantilever bending moment applied to 2 generations of pressfit acetabular components. BMD data were also obtained from the femoral necks available for associated specimen. The mean bending moment at 150 μm was not found to be significantly different for Gription (24.6 ± 14.0 N m) cups vs Porocoat (25 ± 10.2 N m; P > .84). The peak bending moment tolerated by Gription cups (33.9 ± 20.3 N m) was not found to be significantly different from Porocoat (33.5 ± 12.2 N m; P > .92). No correlation between BMD and bending moment at 150 μm of displacement could be identified. The coefficient of friction provided by highly porous metal acetabular shells used in this study did not provide better resistance to migration under bending load when compared with a standard porous coated component. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Enhancing the resonance stability of a high-Q micro/nanoresonator by an optical means

    Science.gov (United States)

    Sun, Xuan; Luo, Rui; Zhang, Xi-Cheng; Lin, Qiang

    2016-02-01

    High-quality optical resonators underlie many important applications ranging from optical frequency metrology, precision measurement, nonlinear/quantum photonics, to diverse sensing such as detecting single biomolecule, electromagnetic field, mechanical acceleration/rotation, among many others. All these applications rely essentially on the stability of optical resonances, which, however, is ultimately limited by the fundamental thermal fluctuations of the devices. The resulting thermo-refractive and thermo-elastic noises have been widely accepted for nearly two decades as the fundamental thermodynamic limit of an optical resonator, limiting its resonance uncertainty to a magnitude 10-12 at room temperature. Here we report a novel approach that is able to significantly improve the resonance stability of an optical resonator. We show that, in contrast to the common belief, the fundamental temperature fluctuations of a high-Q micro/nanoresonator can be suppressed remarkably by pure optical means without cooling the device temperature, which we term as temperature squeezing. An optical wave with only a fairly moderate power launched into the device is able to produce strong photothermal backaction that dramatically suppresses the spectral intensity of temperature fluctuations by five orders of magnitudes and squeezes the overall level (root-mean-square value) of temperature fluctuations by two orders of magnitude. The proposed approach is universally applicable to various micro/nanoresonator platforms and the optimal temperature squeezing can be achieved with an optical Q around 106-107 that is readily available in various current devices. The proposed photothermal temperature squeezing is expected to have profound impact on broad applications of high-Q cavities in sensing, metrology, and integrated nonlinear/quantum photonics.

  9. Stability of buffer-free freeze-dried formulations: A feasibility study of a monoclonal antibody at high protein concentrations.

    Science.gov (United States)

    Garidel, Patrick; Pevestorf, Benjamin; Bahrenburg, Sven

    2015-11-01

    We studied the stability of freeze-dried therapeutic protein formulations over a range of initial concentrations (from 40 to 160 mg/mL) and employed a variety of formulation strategies (including buffer-free freeze dried formulations, or BF-FDF). Highly concentrated, buffer-free liquid formulations of therapeutic monoclonal antibodies (mAbs) have been shown to be a viable alternative to conventionally buffered preparations. We considered whether it is feasible to use the buffer-free strategy in freeze-dried formulations, as an answer to some of the known drawbacks of conventional buffers. We therefore conducted an accelerated stability study (24 weeks at 40 °C) to assess the feasibility of stabilizing freeze-dried formulations without "classical" buffer components. Factors monitored included pH stability, protein integrity, and protein aggregation. Because the protein solutions are inherently self-buffering, and the system's buffer capacity scales with protein concentration, we included highly concentrated buffer-free freeze-dried formulations in the study. The tested formulations ranged from "fully formulated" (containing both conventional buffer and disaccharide stabilizers) to "buffer-free" (including formulations with only disaccharide lyoprotectant stabilizers) to "excipient-free" (with neither added buffers nor stabilizers). We evaluated the impacts of varying concentrations, buffering schemes, pHs, and lyoprotectant additives. At the end of 24 weeks, no change in pH was observed in any of the buffer-free formulations. Unbuffered formulations were found to have shorter reconstitution times and lower opalescence than buffered formulations. Protein stability was assessed by visual inspection, sub-visible particle analysis, protein monomer content, charge variants analysis, and hydrophobic interaction chromatography. All of these measures found the stability of buffer-free formulations that included a disaccharide stabilizer comparable to buffer

  10. Effectiveness of silica based sol-gel microencapsulation method for odorants and flavors leading to sustainable environment.

    Science.gov (United States)

    Ashraf, Muhammad Aqeel; Khan, Aysha Masood; Ahmad, Mushtaq; Sarfraz, Maliha

    2015-01-01

    Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol-gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol-gel SiO2 is non-toxic and safe, whereas the sol-gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped active agents, thereby broadening the practical utilization of chemically unstable essential oils (EOs). Reviewing progress in the fabrication of diverse odorant and flavored sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits.

  11. Effectiveness of silica based Sol-gel microencapsulation Method for odorants and flavours leading to sustainable Environment

    Directory of Open Access Journals (Sweden)

    Muhammad Aqeel eAshraf

    2015-08-01

    Full Text Available Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol–gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol–gel SiO2 is non-toxic and safe, whereas the sol–gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped actives, thereby broadening the practical utilization of chemically unstable essential oils. Reviewing progress in the fabrication of diverse odorant and flavoured sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits.

  12. Effectiveness of silica based sol-gel microencapsulation method for odorants and flavors leading to sustainable environment

    Science.gov (United States)

    Ashraf, Muhammad Aqeel; Khan, Aysha Masood; Ahmad, Mushtaq; Sarfraz, Maliha

    2015-01-01

    Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol-gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol-gel SiO2 is non-toxic and safe, whereas the sol-gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped active agents, thereby broadening the practical utilization of chemically unstable essential oils (EOs). Reviewing progress in the fabrication of diverse odorant and flavored sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits. PMID:26322304

  13. Characterization of an antennal carboxylesterase from the pest moth Spodoptera littoralis degrading a host plant odorant.

    Directory of Open Access Journals (Sweden)

    Nicolas Durand

    2010-11-01

    Full Text Available Carboxyl/cholinesterases (CCEs are highly diversified in insects. These enzymes have a broad range of proposed functions, in neuro/developmental processes, dietary detoxification, insecticide resistance or hormone/pheromone degradation. As few functional data are available on purified or recombinant CCEs, the physiological role of most of these enzymes is unknown. Concerning their role in olfaction, only two CCEs able to metabolize sex pheromones have been functionally characterized in insects. These enzymes are only expressed in the male antennae, and secreted into the lumen of the pheromone-sensitive sensilla. CCEs able to hydrolyze other odorants than sex pheromones, such as plant volatiles, have not been identified.In Spodoptera littoralis, a major crop pest, a diversity of antennal CCEs has been previously identified. We have employed here a combination of molecular biology, biochemistry and electrophysiology approaches to functionally characterize an intracellular CCE, SlCXE10, whose predominant expression in the olfactory sensilla suggested a role in olfaction. A recombinant protein was produced using the baculovirus system and we tested its catabolic properties towards a plant volatile and the sex pheromone components.We showed that SlCXE10 could efficiently hydrolyze a green leaf volatile and to a lesser extent the sex pheromone components. The transcript level in male antennae was also strongly induced by exposure to this plant odorant. In antennae, SlCXE10 expression was associated with sensilla responding to the sex pheromones and to plant odours. These results suggest that a CCE-based intracellular metabolism of odorants could occur in insect antennae, in addition to the extracellular metabolism occurring within the sensillar lumen. This is the first functional characterization of an Odorant-Degrading Enzyme active towards a host plant volatile.

  14. Characterization of Odorant Compounds from Mechanical Aerated Pile Composting and Static Aerated Pile Composting

    Directory of Open Access Journals (Sweden)

    Priyanka Kumari

    2016-04-01

    Full Text Available We studied airborne contaminants (airborne particulates and odorous compounds emitted from compost facilities in South Korea. There are primarily two different types of composting systems operating in Korean farms, namely mechanical aerated pile composting (MAPC and aerated static pile composting (SAPC. In this study, we analyzed various particulate matters (PM10, PM7, PM2.5, PM1, and total suspended particles, volatile organic compounds and ammonia, and correlated these airborne contaminants with microclimatic parameters, i.e., temperature and relative humidity. Most of the analyzed airborne particulates (PM7, PM2.5, and PM1 were detected in high concentration at SAPC facilities compered to MAPC; however these differences were statistically non-significant. Similarly, most of the odorants did not vary significantly between MAPC and SAPC facilities, except for dimethyl sulfide (DMS and skatole. DMS concentrations were significantly higher in MAPC facilities, whereas skatole concentrations were significantly higher in SAPC facilities. The microclimate variables also did not vary significantly between MAPC and SAPC facilities, and did not correlate significantly with most of the airborne particles and odorous compounds, suggesting that microclimate variables did not influence their emission from compost facilities. These findings provide insight into the airborne contaminants that are emitted from compost facilities and the two different types of composting agitation systems.

  15. Characterization of Odorant Compounds from Mechanical Aerated Pile Composting and Static Aerated Pile Composting.

    Science.gov (United States)

    Kumari, Priyanka; Lee, Joonhee; Choi, Hong-Lim

    2016-04-01

    We studied airborne contaminants (airborne particulates and odorous compounds) emitted from compost facilities in South Korea. There are primarily two different types of composting systems operating in Korean farms, namely mechanical aerated pile composting (MAPC) and aerated static pile composting (SAPC). In this study, we analyzed various particulate matters (PM10, PM7, PM2.5, PM1, and total suspended particles), volatile organic compounds and ammonia, and correlated these airborne contaminants with microclimatic parameters, i.e., temperature and relative humidity. Most of the analyzed airborne particulates (PM7, PM2.5, and PM1) were detected in high concentration at SAPC facilities compered to MAPC; however these differences were statistically non-significant. Similarly, most of the odorants did not vary significantly between MAPC and SAPC facilities, except for dimethyl sulfide (DMS) and skatole. DMS concentrations were significantly higher in MAPC facilities, whereas skatole concentrations were significantly higher in SAPC facilities. The microclimate variables also did not vary significantly between MAPC and SAPC facilities, and did not correlate significantly with most of the airborne particles and odorous compounds, suggesting that microclimate variables did not influence their emission from compost facilities. These findings provide insight into the airborne contaminants that are emitted from compost facilities and the two different types of composting agitation systems.

  16. Analysis on the formation condition of the algae-induced odorous black water agglomerate

    Science.gov (United States)

    Wang, Guofang; Li, Xianning; Fang, Yang; Huang, Rui

    2014-01-01

    The algae-induced odorous black water agglomerate (OBWA) is a phenomenon in which water turns black and emits odorous gas. It is an ecological and environmental problem that has occurred several times in Taihu, a large eutrophic shallow lake in China. In this study, the collected eutrophic water with different algae densities was used to simulate OBWA. The results revealed that the massive accumulation and death of algae was the substrate source for OBWA. When the algae density reached 1.0 × 108 cells/L in the static and dark condition, at a constant high temperature (30 ± 2 °C), OBWA happened. There was a time difference between the water stinking and blackening with the stinking first. When the oxidation–reduction potential (ORP) value was between −250 and −50 mV, Dimethyl trisulfide (DMTS), the main contributor to the water stinking at the initial stage, and other odorous organics were produced. Water blackening was closely related to the increases of sulfide and dissolved Fe2+ concentration. When the ORP value was between −350 and −300 mV, heavy metal containing sulfides such as FeS formed. Therefore, the condition when the water ORP value decreased to about −300 mV was considered the precursor for OBWA formation. PMID:25473369

  17. Impedance spectroscopy analysis of human odorant binding proteins immobilized on nanopore arrays for biochemical detection.

    Science.gov (United States)

    Lu, Yanli; Zhang, Diming; Zhang, Qian; Huang, Yixuan; Luo, Senbiao; Yao, Yao; Li, Shuang; Liu, Qingjun

    2016-05-15

    Human odorant-binding proteins (hOBPs) not only can bind and transport odorants in the surrounding environment for sensing smells, but also play important roles in transmitting lots of biomolecules in different organs. Utilizing the properties of hOBPs, an electrochemical biosensor with nanopore array was developed to detect specific biomolecular ligands, such as aldehydes and fatty acids. The highly ordered nanopores of anodic aluminum oxide with diameter of 20-40 nm were fabricated with two-step oxidation. Through 2-carboxyethyl phosphonic acid, hOBPs were self-assembled on nanopores as the sensing membrane. With nanopore arrays, the impedance spectra showed quite different electron transfer processes in the frequency spectra, which could be characterized by the electron transfer resistance and electrical resistance of the porous membrane. Under stimulation of biomolecular ligands, series resistance of nanopores and hOBPs increased and showed a concentration-dependence feature, while the electron transfer resistance hardly changed. The nanopore based biosensor could sensitively detect biological ligands of benzaldehyde, docosahexaenoic acid, and lauric acid, which were closely related to or were potential biomarkers for cancers and other serious diseases. Equipped with hOBPs, the sensor exhibited promising potentials both in odorant and biomolecule detection for olfactory biosensing and in disease diagnosis and evaluation for biochemical detection. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Analysis on the formation condition of the algae-induced odorous black water agglomerate.

    Science.gov (United States)

    Wang, Guofang; Li, Xianning; Fang, Yang; Huang, Rui

    2014-12-01

    The algae-induced odorous black water agglomerate (OBWA) is a phenomenon in which water turns black and emits odorous gas. It is an ecological and environmental problem that has occurred several times in Taihu, a large eutrophic shallow lake in China. In this study, the collected eutrophic water with different algae densities was used to simulate OBWA. The results revealed that the massive accumulation and death of algae was the substrate source for OBWA. When the algae density reached 1.0 × 10(8) cells/L in the static and dark condition, at a constant high temperature (30 ± 2 °C), OBWA happened. There was a time difference between the water stinking and blackening with the stinking first. When the oxidation-reduction potential (ORP) value was between -250 and -50 mV, Dimethyl trisulfide (DMTS), the main contributor to the water stinking at the initial stage, and other odorous organics were produced. Water blackening was closely related to the increases of sulfide and dissolved Fe(2+) concentration. When the ORP value was between -350 and -300 mV, heavy metal containing sulfides such as FeS formed. Therefore, the condition when the water ORP value decreased to about -300 mV was considered the precursor for OBWA formation.

  19. Scent marking behavior as an odorant communication in mice

    Science.gov (United States)

    Arakawa, Hiroyuki; Blanchard, D. Caroline; Arakawa, Keiko; Dunlap, Christopher; Blanchard, Robert J.

    2008-01-01

    In rodents, where chemical signals play a particularly important role in determining intraspecies interactions including social dominance and intersexual relationships, various studies have shown that behavior is sensitive to conspecific odor cues. Mice use urinary scent marks for communication with individual conspecifics in many social contexts. Urinary scent involves genetic information about individuals such as species, sex, and individual identity as well as metabolic information such as social dominance, and reproductive and health status, which are mediated by chemical proteins in scent marks including the major histocompatibility complex and the major urinary proteins. The odor of the predator which can be considered to be a threatening signal for the prey also modulate mouse behavior in which scent marking is suppressed in response to the cat odor exposure in mice. These odorant chemicals are detected and recognized through two olfactory bulbs, the role of which in detection of chemosignals with biological relevant appears to be differential, but partly overlapped. Mice deposit scent marks toward conspecifics to maintain their social relationships, and inhibit scent marking in a context where natural predator, cat odor is contained. This suppression of scent marking is long-lasting (for at least 7 days) and context-dependent, while the odorant signaling to conspecifics tends to appear frequently (over 24 hrs but less than 7 days intervals) depending on the familiarity of each signal-recipient. It has been discussed that scent marking is a communicative behavior associated with territoriality toward conspecifics, indicating that the social signaling within species are sensitive to predator odor cues in terms of vulnerability to predation risk. PMID:18565582

  20. Odors bias time perception in visual and auditory modalities

    Directory of Open Access Journals (Sweden)

    Zhenzhu eYue

    2016-04-01

    Full Text Available Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 ms or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor. The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a

  1. Odors Bias Time Perception in Visual and Auditory Modalities.

    Science.gov (United States)

    Yue, Zhenzhu; Gao, Tianyu; Chen, Lihan; Wu, Jiashuang

    2016-01-01

    Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal) were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor). The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a framework of

  2. Synthesis and high temperature stability of amorphous Si(B)CN-MWCNT composite nanowires

    Science.gov (United States)

    Bhandavat, Romil; Singh, Gurpreet

    2012-02-01

    We demonstrate synthesis of a hybrid nanowire structure consisting of an amorphous polymer-derived silicon boron-carbonitride (Si-B-C-N) shell with a multiwalled carbon nanotube core. This was achieved through a novel process involving preparation of a boron-modified liquid polymeric precursor through a reaction of trimethyl borate and polyureasilazane under atmospheric conditions; followed by conversion of polymer to glass-ceramic on carbon nanotube surfaces through controlled heating. Chemical structure of the polymer was studied by liquid-NMR while evolution of various ceramic phases was studied by Raman spectroscopy, solid-NMR, Fourier transform infrared and X-ray photoelectron spectroscopy. Electron microscopy and X-ray diffraction confirms presence of amorphous Si(B)CN coating on individual nanotubes for all specimen processed below 1400 degree C. Thermogravimetric analysis, followed by TEM revealed high temperature stability of the carbon nanotube core in flowing air up to 1300 degree C.

  3. Controlled synthesis of porous anhydrous cobalt oxalate nanorods with high reversible capacity and excellent cycling stability

    International Nuclear Information System (INIS)

    Xu, Junmin; He, Lei; Liu, Hui; Han, Tao; Wang, Yongjian; Zhang, Changjin; Zhang, Yuheng

    2015-01-01

    Graphical abstract: Display Omitted -- Abstract: One-dimensional porous anhydrous cobalt oxalate nanorods are prepared via a facile water-controlled coprecipitate method followed by thermal annealing treatment under N 2 at 300 °C. The nanorods are characterized by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. When evaluated as an anode material for lithium ion batteries, the nanorods exhibit high reversible specific capacity and excellent cycling stability (924 mA h g −1 at 50 mA g −1 after 100 cycles and 709 mA h g −1 at 200 mA g −1 after 220 cycles). This remarkable electrochemical performance is attributed to the one-dimensional porous nanostructure that can provide large electrode/electrolyte contact area and short lithium-ion diffusion pathway, meanwhile reduce the volume expansion during the repeated discharge/charge process

  4. Mechanical stability of bentonite buffer system for high level nuclear waste

    International Nuclear Information System (INIS)

    Lempinen, A.

    1998-05-01

    According to present plans, high level nuclear waste in Finland is going to be disposed of in bedrock at a depth of several hundred metres. The spent fuel containers will be placed in boreholes drilled in the floors of deposition tunnels with engineered clay buffer, which is made of bentonite blocks. The tunnels will be filled with a mixture of bentonite and crushed rock. For stability calculations a thermomechanical model for compressed bentonite is needed. In the study a thermomechanically consistent model for reversible processes for swelling clays is presented. Preliminary calculations were performed and they show that uncertainty in material parameter values causes significantly different results. Therefore, measurements that are consistent with the model are needed

  5. A simple hydrothermal route to bimodal mesoporous nanorod {gamma}-alumina with high thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiang; Han, Dezhi; Xue, Hongxia; Liu, Xinmei; Yan, Zifeng [China Univ. of Petroleum, Qingdao (China). State Key Lab. of Heavy Oil Processing

    2011-12-15

    In the presence of polyethylene glycol, bimodal mesoporous nanorod {gamma}-alumina was successfully synthesized via the thermal decomposition of ammonium aluminium carbonate hydroxide precursor which was prepared via hydrothermal processing with inorganic aluminium salt. The alumina exhibits high surface area (494 m{sup 2}g{sup -1}), large porosity (1.1 m{sup 3}g{sup -1}) and a particular double-pore structure after calcination at 500 C. The smaller pore diameter is concentrated on about 3 nm and the larger one is exhibited in the range of 10 - 38 nm. The scaffold-like aggregation of {gamma}-alumina nanorods endows this novel material with excellent thermal stability. A possible formation mechanism of bimodal mesoporous structure is also proposed in this study. (orig.)

  6. Flexion and anterior knee pain after high flexion posterior stabilized or cruciate retaining knee replacement.

    Science.gov (United States)

    van de Groes, Sebastiaan; van der Ven, Paul; Kremers-van de Hei, Keetie; Koëter, Sander; Verdonschot, Nico

    2015-12-01

    Special high-flexion prosthetic designs show a small increase in postoperative flexion compared to standard designs and some papers show increased anterior knee pain with these prosthesis. A prospective double blind randomized controlled trial investigates the difference in flexion and anterior knee pain between standard and high-flexion total knee arthroplasty. In total 47 patients were randomly allocated to a standard cruciate retaining fixed bearing design (CR) in 23 patients and to a high-flexion posterior stabilized mobile bearing design (HF-PS) in 24 patients. The HF-PS did show a significantly higher passive postoperative flexion; 120.8° (SD 10.3°) vs. 112.0° (SD 9.5°) for the CR group (p = 0.004). The active postoperative flexion, VAS-pain score and Feller score did not show significant differences between both groups. Sub analysis with the HF-PS group showed a higher VAS-pain for the patients achieving ≥130° of flexion; 30.5 (SD 32.2) vs. 12.2 (SD 12.5) (p = 0.16). The present study showed a significant higher passive flexion in the high-flexion prosthesis compared to the standard prosthesis. However this difference disappeared when comparing active flexion. No difference in anterior knee pain was found between both groups.

  7. Stability of very-high pressure arc discharges against perturbations of the electron temperature

    Energy Technology Data Exchange (ETDEWEB)

    Benilov, M. S. [Departamento de Fisica, Ciencias Exactas e Engenharia, Universidade da Madeira, Largo do Municipio, Funchal 9000 (Portugal); Hechtfischer, U. [Philips Lighting, BU Automotive Lamps, Technology, Philipsstrasse 8, Aachen 52068 (Germany)

    2012-04-01

    We study the stability of the energy balance of the electron gas in very high-pressure plasmas against longitudinal perturbations, using a local dispersion analysis. After deriving a dispersion equation, we apply the model to a very high-pressure (100 bar) xenon plasma and find instability for electron temperatures, T{sub e}, in a window between 2400 K and 5500-7000 K x 10{sup 3} K, depending on the current density (10{sup 6}-10{sup 8} A/m{sup 2}). The instability can be traced back to the Joule heating of the electron gas being a growing function of T{sub e}, which is due to a rising dependence of the electron-atom collision frequency on T{sub e}. We then analyze the T{sub e} range occurring in very high-pressure xenon lamps and conclude that only the near-anode region exhibits T{sub e} sufficiently low for this instability to occur. Indeed, previous experiments have revealed that such lamps develop, under certain conditions, voltage oscillations accompanied by electromagnetic interference, and this instability has been pinned down to the plasma-anode interaction. A relation between the mechanisms of the considered instability and multiple anodic attachments of high-pressure arcs is discussed.

  8. Stabilization of red fruit-based smoothies by high-pressure processing. Part A. Effects on microbial growth, enzyme activity, antioxidant capacity and physical stability.

    Science.gov (United States)

    Hurtado, Adriana; Guàrdia, Maria Dolors; Picouet, Pierre; Jofré, Anna; Ros, José María; Bañón, Sancho

    2017-02-01

    Non-thermal pasteurization by high-pressure processing (HPP) is increasingly replacing thermal processing (TP) to maintain the properties of fresh fruit products. However, most of the research on HPP-fruit products only partially addresses fruit-pressure interaction, which limits its practical interest. The objective of this study was to assess the use of a mild HPP treatment to stabilize red fruit-based smoothies (microbial, enzymatic, oxidative and physical stability). HPP (350 MPa/10 °C/5 min) was slightly less effective than TP (85 °C/7 min) in inactivating microbes (mesophilic and psychrophilic bacteria, coliforms, yeasts and moulds) in smoothies kept at 4 °C for up to 28 days. The main limitation of using HPP was its low efficacy in inactivating oxidative (polyphenol oxidase and peroxidase) and hydrolytic (pectin methyl esterase) enzymes. Data on antioxidant status, colour parameters, browning index, transmittance, turbidity and viscosity confirmed that the HPP-smoothies have a greater tendency towards oxidation and clarification, which might lead to undesirable sensory and nutritional changes (see Part B). The microbial quality of smoothies was adequately controlled by mild HPP treatment without affecting their physical-chemical characteristics; however, oxidative and hydrolytic enzymes are highly pressure-resistant, which suggests that additional strategies should be used to stabilize smoothies. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  9. High-Efficiency and High-Operational-Stability Top-Emitting Organic Light-Emitting Diodes Using Antioxidant Buffer Layer

    Science.gov (United States)

    Murakami, Hajime; Shimizu, Masao; Aratani, Sukekazu; Tanaka, Masahiro

    2009-08-01

    We have succeeded in developing top-emitting organic light-emitting diodes (OLEDs) with high efficiency and high operational stability using an antioxidant buffer layer. V2O5 was selected as the antioxidant buffer layer to suppress the degradation of the organic materials of OLEDs caused by active oxygen during buffer layer deposition and the damage caused by the bombardment of high-energy particles during transparent electrode sputtering. The top-emitting device with a V2O5 buffer layer had the same current density-voltage (J-V) characteristics as the bottom-emitting device with the same material system. The quantum efficiency of the top-emitting device was about 5%, the same as that of the bottom-emitting device. The time required for luminance to drop to 90% of the initial value of the top-emitting device was over 700 h, which is longer than that of the bottom-emitting device (300 h). From X-ray photoelectron spectroscopy (XPS) analysis of the interface between organic materials and V2O5, it was determined that there was no degradation of organic materials under V2O5.

  10. Stability of phases at high temperatures in CoRe based alloys being developed for ultra-high temperature applications

    Science.gov (United States)

    Gilles, R.; Strunz, P.; Mukherji, D.; Hofmann, M.; Hoelzel, M.; Roesler, J.

    2012-02-01

    In the development of new high-temperature alloys for gas turbine applications various candidates are under consideration. This contribution deals with a CoRe based alloy strengthened by Cr23C6 type carbide and Cr2Re3 type σ phase precipitations (here designated as CoRe-1 alloy). High-temperature cycling experiments show how the influence of heating, cooling and the hcpfcc phase transformation of the Co-matrix on the stability of these phases. Neutron diffraction experiments with high-temperature vacuum furnace show that Cr23C6 carbides starts to dissolve around 1100°C and above 1250°C are almost completely dissolved. On the other hand σ phase is still present at 1300°C. This contribution describes the evolution of the different phases during the heating and cooling cycles which are repeated two times. Further, the influence of boron addition to CoRe-1 alloy was studied for samples in the first heating/cooling cycle. A newly developed tensile rig was also tested up to 980°C to combine in situ loading and heating for the neutron diffraction measurements.

  11. High operational and environmental stability of high-mobility conjugated polymer field-effect transistors through the use of molecular additives

    KAUST Repository

    Nikolka, Mark

    2016-12-12

    Due to their low-temperature processing properties and inherent mechanical flexibility, conjugated polymer field-effect transistors (FETs) are promising candidates for enabling flexible electronic circuits and displays. Much progress has been made on materials performance; however, there remain significant concerns about operational and environmental stability, particularly in the context of applications that require a very high level of threshold voltage stability, such as active-matrix addressing of organic light-emitting diode displays. Here, we investigate the physical mechanisms behind operational and environmental degradation of high-mobility, p-type polymer FETs and demonstrate an effective route to improve device stability. We show that water incorporated in nanometre-sized voids within the polymer microstructure is the key factor in charge trapping and device degradation. By inserting molecular additives that displace water from these voids, it is possible to increase the stability as well as uniformity to a high level sufficient for demanding industrial applications.

  12. Odor identity influences tracking of temporally patterned plumes in Drosophila

    Directory of Open Access Journals (Sweden)

    Frye Mark A

    2011-06-01

    Full Text Available Abstract Background Turbulent fluid landscapes impose temporal patterning upon chemical signals, and the dynamical neuronal responses to patterned input vary across the olfactory receptor repertoire in flies, moths, and locusts. Sensory transformations exhibit low pass filtering that ultimately results in perceptual fusion of temporally transient sensory signals. For example, humans perceive a sufficiently fast flickering light as continuous, but the frequency threshold at which this fusion occurs varies with wavelength. Although the summed frequency sensitivity of the fly antenna has been examined to a considerable extent, it is unknown how intermittent odor signals are integrated to influence plume tracking behavior independent of wind cues, and whether temporal fusion for behavioral tracking might vary according to the odor encountered. Results Here we have adopted a virtual reality flight simulator to study the dynamics of plume tracking under different experimental conditions. Flies tethered in a magnetic field actively track continuous (non-intermittent plumes of vinegar, banana, or ethyl butyrate with equal precision. However, pulsing these plumes at varying frequency reveals that the threshold rate, above which flies track the plume as if it were continuous, is unique for each odorant tested. Thus, the capability of a fly to navigate an intermittent plume depends on the particular odorant being tracked during flight. Finally, we measured antennal field potential responses to an intermittent plume, found that receptor dynamics track the temporal pattern of the odor stimulus and therefore do not limit the observed behavioral temporal fusion limits. Conclusions This study explores the flies' ability to track odor plumes that are temporally intermittent. We were surprised to find that the perceptual critical fusion limit, determined behaviorally, is strongly dependent on odor identity. Antennal field potential recordings indicate that

  13. Anomalous perovskite PbRuO3 stabilized under high pressure

    Science.gov (United States)

    Cheng, J.-G.; Kweon, K. E.; Zhou, J.-S.; Alonso, J. A.; Kong, P.-P.; Liu, Y.; Jin, Changqing; Wu, Junjie; Lin, Jung-Fu; Larregola, S. A.; Yang, Wenge; Shen, Guoyin; MacDonald, A. H.; Manthiram, Arumugam; Hwang, G. S.; Goodenough, John B.

    2013-01-01

    Perovskite oxides ABO3 are important materials used as components in electronic devices. The highly compact crystal structure consists of a framework of corner-shared BO6 octahedra enclosing the A-site cations. Because of these structural features, forming a strong bond between A and B cations is highly unlikely and has not been reported in the literature. Here we report a pressure-induced first-order transition in PbRuO3 from a common orthorhombic phase (Pbnm) to an orthorhombic phase (Pbn21) at 32 GPa by using synchrotron X-ray diffraction. This transition has been further verified with resistivity measurements and Raman spectra under high pressure. In contrast to most well-studied perovskites under high pressure, the Pbn21 phase of PbRuO3 stabilized at high pressure is a polar perovskite. More interestingly, the Pbn21 phase has the most distorted octahedra and a shortest Pb—Ru bond length relative to the average Pb—Ru bond length that has ever been reported in a perovskite structure. We have also simulated the behavior of the PbRuO3 perovskite under high pressure by first principles calculations. The calculated critical pressure for the phase transition and evolution of lattice parameters under pressure match the experimental results quantitatively. Our calculations also reveal that the hybridization between a Ru:t2g orbital and an sp hybrid on Pb increases dramatically in the Pbnm phase under pressure. This pressure-induced change destabilizes the Pbnm phase to give a phase transition to the Pbn21 phase where electrons in the overlapping orbitals form bonding and antibonding states along the shortest Ru—Pb direction at P > Pc. PMID:24277807

  14. Deformation Monitoring of Geomechanical Model Test and Its Application in Overall Stability Analysis of a High Arch Dam

    Directory of Open Access Journals (Sweden)

    Baoquan Yang

    2015-01-01

    Full Text Available Geomechanical model testing is an important method for studying the overall stability of high arch dams. The main task of a geomechanical model test is deformation monitoring. Currently, many types of deformation instruments are used for deformation monitoring of dam models, which provide valuable information on the deformation characteristics of the prototype dams. However, further investigation is required for assessing the overall stability of high arch dams through analyzing deformation monitoring data. First, a relationship for assessing the stability of dams is established based on the comprehensive model test method. Second, a stability evaluation system is presented based on the deformation monitoring data, together with the relationships between the deformation and overloading coefficient. Finally, the comprehensive model test method is applied to study the overall stability of the Jinping-I high arch dam. A three-dimensional destructive test of the geomechanical model dam is conducted under reinforced foundation conditions. The deformation characteristics and failure mechanisms of the dam abutments and foundation were investigated. The test results indicate that the stability safety factors of the dam abutments and foundation range from 5.2 to 6.0. These research results provide an important scientific insight into the design, construction, and operation stages of this project.

  15. High stability of the immunomodulatory GK-1 synthetic peptide measured by a reversed phase high-performance liquid chromatography method.

    Science.gov (United States)

    Cervantes-Torres, Jacquelynne; Segura-Velázquez, René; Padilla, Patricia; Sciutto, Edda; Fragoso, Gladis

    2017-08-15

    The 18-mer anionic peptide GK-1 has been successfully employed to improve the immunogenicity and protective response induced by the influenza vaccine and exhibited some degree of protection against experimental murine melanoma. In this study, a sensitive and quantitative reversed-phase HPLC method was developed to study GK-1 stability under different pH, temperature and storage time. The analysis was carried out on a Sunfire C18 column with mobile phase of acetonitrile-water containing 0.02% TFA. The detection was performed on an UV/Vis Detector at 220nm. The method was validated with respect to linearity, limits of detection and quantification, precision and selectivity. The linear calibration curves were obtained in the concentration range of 0.015-0.24mg/mL (r 2 =0.99) with lower limits of detection (LOD) and quantification (LOQ) of 0.001 and 0.018mg/mL, respectively. The intra- and inter-day precision (relative standard deviation, R.S.D.) values were below 3% at all quality control levels. Forced degradation studies were conducted by introducing a sample of GK-1 peptide standard solution to different conditions of pH (from 2 to 8), temperature (4, 25 and 40°C) and storage time (10days to 6 months). The peptide GK-1 showed to be stable under different ranges of pH and temperature; however it was susceptible to prolonged storage at room temperature. Results shown in this study sustain the high stability of the GK-1 peptide using a reliable new selective and precise method suitable for its analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Simplified seismic stability evaluation of gravity dams subjected to high frequency eastern North American ground motions

    Energy Technology Data Exchange (ETDEWEB)

    Leger, P.; Ftima, M.B. [Ecole Polytechnique, Montreal, PQ (Canada)

    2004-09-01

    This study examined the use of simplified seismic analysis procedures to evaluate the dynamic stability of concrete dams subjected to high frequencies that are typical of eastern North America (ENA) earthquake ground motions. A typical 60 meter high concrete gravity dam was used to illustrate that dams subjected to severe high frequency ground motions are likely to experience cracking and sliding in the upper section where dynamic amplification is critical. In particular, this study examined the possibility of computing in-structure response spectra (ISRS) at the base of a sliding block to define suitable spectra compatible accelerograms. Analyzing the cracked component requires a definition of seismic input motions at the base of the block while considering dynamic amplification. It was concluded that it is not conservative to use accelerograms compatible with the linear, uncracked dam ISRS to perform transient rigid body sliding response analyses. It was noted that dynamic properties depend on dam base and upper joint cracking. Therefore, the intensity and frequency of seismic motions are modified as they propagate across the height of the dam. A nonlinear ISRS computed from cracked beam models is recommended for obtaining a conservative estimate of the residual sliding displacement of the upper block. 12 refs., 3 tabs., 8 figs.

  17. High-quality crystalline yttria-stabilized-zirconia thin layer for photonic applications

    Science.gov (United States)

    Marcaud, Guillaume; Matzen, Sylvia; Alonso-Ramos, Carlos; Le Roux, Xavier; Berciano, Mathias; Maroutian, Thomas; Agnus, Guillaume; Aubert, Pascal; Largeau, Ludovic; Pillard, Valérie; Serna, Samuel; Benedikovic, Daniel; Pendenque, Christopher; Cassan, Eric; Marris-Morini, Delphine; Lecoeur, Philippe; Vivien, Laurent

    2018-03-01

    Functional oxides are considered as promising materials for photonic applications due to their extraordinary and various optical properties. Especially, yttria-stabilized zirconia (YSZ) has a high refractive index (˜2.15), leading to a good confinement of the optical mode in waveguides. Furthermore, YSZ can also be used as a buffer layer to expand toward a large family of oxides-based thin-films heterostructures. In this paper, we report a complete study of the structural properties of YSZ for the development of integrated optical devices on sapphire in telecom wavelength range. The substrate preparation and the epitaxial growth using pulsed-laser deposition technique have been studied and optimized. High-quality YSZ thin films with remarkably sharp x-ray diffraction rocking curve peaks in 10-3∘ range have then been grown on sapphire (0001). It was demonstrated that a thermal annealing of sapphire substrate before the YSZ growth allowed controlling the out-of-plane orientation of the YSZ thin film. Single-mode waveguides were finally designed, fabricated, and characterized for two different main orientations of high-quality YSZ (001) and (111). Propagation loss as low as 2 dB/cm at a wavelength of 1380 nm has been demonstrated for both orientations. These results pave the way for the development of a functional oxides-based photonics platform for numerous applications including on-chip optical communications and sensing.

  18. New route toward building active ruthenium nanoparticles on ordered mesoporous carbons with extremely high stability

    Science.gov (United States)

    Yang, Ying; Sun, Chengjun; Ren, Yang; Hao, Shijie; Jiang, Daqiang

    2014-04-01

    Creating highly active and stable metal catalysts is a persistent goal in the field of heterogeneous catalysis. However, a real catalyst can rarely achieve both of these qualities simultaneously due to limitations in the design of the active site and support. One method to circumvent this problem is to fabricate firmly attached metal species onto the voids of a mesoporous support formed simultaneously. In this study, we developed a new type of ruthenium catalyst that was firmly confined by ordered mesoporous carbons through the fabrication of a cubic Ia3d chitosan-ruthenium-silica mesophase before pyrolysis and silica removal. This facile method generates fine ruthenium nanoparticles (ca. 1.7 nm) that are homogeneously dispersed on a mesoporous carbonaceous framework. This ruthenium catalyst can be recycled 22 times without any loss of reactivity, showing the highest stability of any metal catalysts; this catalyst displays a high activity (23.3 molLAh-1gmetal-1) during the catalytic hydrogenation of levulinic acid (LA) when the metal loading is 6.1 wt%. Even at an ultralow loading (0.3 wt%), this catalyst still outperforms the most active known Ru/C catalyst. This work reveals new possibilities for designing and fabricating highly stable and active metal catalysts by creating metal sites and mesoporous supports simultaneously.

  19. A high-stability non-contact dilatometer for low-amplitude temperature-modulated measurements

    Energy Technology Data Exchange (ETDEWEB)

    Luckabauer, Martin; Sprengel, Wolfgang; Würschum, Roland [Institute of Materials Physics, Graz University of Technology, A-8010 Graz (Austria)

    2016-07-15

    Temperature modulated thermophysical measurements can deliver valuable insights into the phase transformation behavior of many different materials. While especially for non-metallic systems at low temperatures numerous powerful methods exist, no high-temperature device suitable for modulated measurements of bulk metallic alloy samples is available for routine use. In this work a dilatometer for temperature modulated isothermal and non-isothermal measurements in the temperature range from room temperature to 1300 K is presented. The length measuring system is based on a two-beam Michelson laser interferometer with an incremental resolution of 20 pm. The non-contact measurement principle allows for resolving sinusoidal length change signals with amplitudes in the sub-500 nm range and physically decouples the length measuring system from the temperature modulation and heating control. To demonstrate the low-amplitude capabilities, results for the thermal expansion of nickel for two different modulation frequencies are presented. These results prove that the novel method can be used to routinely resolve length-change signals of metallic samples with temperature amplitudes well below 1 K. This high resolution in combination with the non-contact measurement principle significantly extends the application range of modulated dilatometry towards high-stability phase transformation measurements on complex alloys.

  20. Investigation on the Stability of Derivative Melam from Melamine Pyrolysis under High Pressure

    Directory of Open Access Journals (Sweden)

    Xiaohong Yuan

    2018-03-01

    Full Text Available Although various kinds of carbon nitride precursors have been proposed, s-triazine-based structures are hardly reported because of their unfavorable energy, higher than that of heptazine-based ones. In this study, we investigate the thermal stability of s-triazine-based melam processed at a high pressure of 5 GPa and a temperature of 400–700 °C and complete the analyses of the composition and structure of the treated samples through X-ray diffraction (XRD, Fourier-transform infrared spectroscopy (FTIR, and elemental analyses (EA. Results show that melam can stably exist up to 600 °C at 5 GPa. XRD and FTIR analyses reveal that residual melamine can be pyrolyzed into melam as temperature increases from 400 °C to 600 °C at a high pressure, suggesting that melam may be purified through high-pressure pyrolysis. Further melam polymerization at a higher pressure is a promising strategy for the preparation of s-triazine-based carbon nitride precursors used for bulk carbon nitride synthesis.

  1. Investigation on the Stability of Derivative Melam from Melamine Pyrolysis under High Pressure.

    Science.gov (United States)

    Yuan, Xiaohong; Luo, Kun; Wu, Yingju; He, Julong; Zhao, Zhisheng; Yu, Dongli

    2018-03-18

    Although various kinds of carbon nitride precursors have been proposed, s-triazine-based structures are hardly reported because of their unfavorable energy, higher than that of heptazine-based ones. In this study, we investigate the thermal stability of s-triazine-based melam processed at a high pressure of 5 GPa and a temperature of 400-700 °C and complete the analyses of the composition and structure of the treated samples through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and elemental analyses (EA). Results show that melam can stably exist up to 600 °C at 5 GPa. XRD and FTIR analyses reveal that residual melamine can be pyrolyzed into melam as temperature increases from 400 °C to 600 °C at a high pressure, suggesting that melam may be purified through high-pressure pyrolysis. Further melam polymerization at a higher pressure is a promising strategy for the preparation of s-triazine-based carbon nitride precursors used for bulk carbon nitride synthesis.

  2. Taste and odor recognition memory: the emotional flavor of life.

    Science.gov (United States)

    Miranda, Maria Isabel

    2012-01-01

    In recent years, our knowledge of the neurobiology of taste and smell has greatly increased; by using several learning models, we now have a better understanding of the behavioral and neurochemical basis of memory recognition. Studies have provided new evidence of some processes that depend on prior experience with the specific combination of sensory stimuli. This review contains recent research related to taste and odor recognition memory, and the goal is to highlight the role of two prominent brain structures, the insular cortex and the amygdala. These structures have an important function during learning and memory and have been associated with the differences in learning induced by the diverse degrees of emotion during taste/odor memory formation, either aversive or appetitive or when taste and odor are combined and/or potentiated.Therefore, this review includes information about certain neurochemical transmitters and their interactions during appetitive or aversive taste memory formation,taste-potentiated odor aversion memory, and conditioned odor aversion, which might be able to maintain the complex processes necessary for flavor recognition memory.

  3. Floral odor learning within the hive affects honeybees' foraging decisions

    Science.gov (United States)

    Arenas, Andrés; Fernández, Vanesa M.; Farina, Walter M.

    2007-03-01

    Honeybees learn odor cues quickly and efficiently when visiting rewarding flowers. Memorization of these cues facilitates the localization and recognition of food sources during foraging flights. Bees can also use information gained inside the hive during social interactions with successful foragers. An important information cue that can be learned during these interactions is food odor. However, little is known about how floral odors learned in the hive affect later decisions of foragers in the field. We studied the effect of food scent on foraging preferences when this learning is acquired directly inside the hive. By using in-hive feeders that were removed 24 h before the test, we showed that foragers use the odor information acquired during a 3-day stimulation period with a scented solution during a food-choice situation outside the nest. This bias in food preference is maintained even 24 h after the replacement of all the hive combs. Thus, without being previously collected outside by foragers, food odors learned within the hive can be used during short-range foraging flights. Moreover, correct landings at a dual-choice device after replacing the storing combs suggests that long-term memories formed within the colony can be retrieved while bees search for food in the field.

  4. Olfactory learning in the rat immediately after birth: unique salience of first odors

    Science.gov (United States)

    Miller, Stacie S.; Spear, Norman E.

    2011-01-01

    An infant rat’s chance of survival is increased when it remains close to the nest. Early olfactory learning supports such adaptive behavior. Previous experiments indicated that non-associative odor exposure immediately after birth promoted later attachment to a similarly scented artificial nipple. The goal of the current experiments was to extend these findings on olfactory learning in the hours after birth by: exposing pups to more than one odor exposure (Exp. 1), dissecting the role of timing versus order of odor exposure (Exp. 2), testing the odor specificity of these effects (Exp. 3 and 4), and evaluating associative odor conditioning soon after birth (Exp. 5). Without explicit prior odor experience, pups only hours old do not respond much to a novel odor. Prior non-associative odor experience increases later motor activity to that same odor and to novel odors. Furthermore, these findings may be specific to certain amodal dimensions of the (in our case) lemon odor exposure. Single odor non-associative and associative conditioning was equally effective immediately after birth and during the third postnatal hour. Nevertheless, pups given two mere odor exposures responded to the first one more than the second at test, regardless of whether the exposures began immediately or two hours after birth. Possible mechanisms for these findings concerning early olfactory learning are discussed. PMID:19582793

  5. Survey of needs and capabilities for wind tunnel testing of dynamic stability of aircraft at high angles of attack

    Science.gov (United States)

    Orlik-Ruckemann, K. J.

    1973-01-01

    A survey was conducted relative to future requirements for dynamic stability information for such aerospace vehicles as the space shuttle and advanced high performance military aircraft. High-angle-of-attack and high-Reynolds number conditions were emphasized. A review was made of the wind-tunnel capabilities in North America for measuring dynamic stability derivatives, revealing an almost total lack of capabilities that could satisfy these requirements. Recommendations are made regarding equipment that should be constructed to remedy this situation. A description is given of some of the more advanced existing capabilities, which can be used to at least partly satisfy immediate demands.

  6. Combination of sodium caseinate and succinylated alginate improved stability of high fat fish oil-in-water emulsions.

    Science.gov (United States)

    Yesiltas, Betül; Sørensen, Ann-Dorit Moltke; García-Moreno, Pedro J; Anankanbil, Sampson; Guo, Zheng; Jacobsen, Charlotte

    2018-07-30

    Sodium caseinate (CAS) and commercial sodium alginate (CA), long chain modified alginate (LCMA) or short chain modified alginate (SCMA) were used in combination for emulsifying and stabilizing high fat (50-70%) fish oil-in-water emulsions. Physical (creaming, droplet size, viscosity and protein determination) and oxidative (primary and secondary oxidation products) stabilities of the emulsions were studied during 12 days of storage. Creaming stability was higher for emulsions produced with alginates and CAS compared to emulsions prepared with only CAS. Combined use of CAS + LCMA performed better in terms of physical stability compared to emulsions produced with only CAS. However, the oxidative stability of this emulsion was inferior probably due to the presence of an unsaturated carbon chain in LCMA structure. CAS + SCMA emulsions not only showed better physical stability such as smaller droplet size, lower creaming and higher viscosity, but also had an improved oxidative stability than emulsions produced with only CAS. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Accelerated Metastable Solid-liquid Interdiffusion Bonding with High Thermal Stability and Power Handling

    Science.gov (United States)

    Huang, Ting-Chia; Smet, Vanessa; Kawamoto, Satomi; Pulugurtha, Markondeya R.; Tummala, Rao R.

    2018-01-01

    Emerging high-performance systems are driving the need for advanced packaging solutions such as 3-D integrated circuits (ICs) and 2.5-D system integration with increasing performance and reliability requirements for off-chip interconnections. Solid-liquid interdiffusion (SLID) bonding resulting in all-intermetallic joints has been proposed to extend the applicability of solders, but faces fundamental and manufacturing challenges hindering its wide adoption. This paper introduces a Cu-Sn SLID interconnection technology, aiming at stabilization of the microstructure in the Cu6Sn5 metastable phase rather than the usual stable Cu3Sn phase. This enables formation of a void-free interface yielding higher mechanical strength than standard SLID bonding, as well as significantly reducing the transition time. The metastable SLID technology retains the benefits of standard SLID with superior I/O pitch scalability, thermal stability and current handling capability, while advancing assembly manufacturability. In the proposed concept, the interfacial reaction is controlled by introducing Ni(P) diffusion barrier layers, designed to effectively isolate the metastable Cu6Sn5 phase preventing any further transformation. Theoretical diffusion and kinetic models were applied to design the Ni-Cu-Sn interconnection stack to achieve the targeted joint composition. A daisy chain test vehicle was used to demonstrate this technology as a first proof of concept. Full transition to Cu6Sn5 was successfully achieved within a minute at 260°C as confirmed by scanning electron microscope (SEM) and x-ray energy dispersive spectroscopy (XEDS) analysis. The joint composition was stable through 10× reflow, with outstanding bond strength averaging 90 MPa. The metastable SLID interconnections also showed excellent electromigration performance, surviving 500 h of current stressing at 105 A/cm2 at 150°C.

  8. Stability of the tungsten diselenide and silicon carbide heterostructure against high energy proton exposure

    Science.gov (United States)

    Walker, Roger C.; Shi, Tan; Jariwala, Bhakti; Jovanovic, Igor; Robinson, Joshua A.

    2017-10-01

    Single layers of tungsten diselenide (WSe2) can be used to construct ultra-thin, high-performance electronics. Additionally, there has been considerable progress in controlled and direct growth of single layers on various substrates. Based on these results, high-quality WSe2-based devices that approach the limit of physical thickness are now possible. Such devices could be useful for space applications, but understanding how high-energy radiation impacts the properties of WSe2 and the WSe2/substrate interface has been lacking. In this work, we compare the stability against high energy proton radiation of WSe2 and silicon carbide (SiC) heterostructures generated by mechanical exfoliation of WSe2 flakes and by direct growth of WSe2 via metal-organic chemical vapor deposition (MOCVD). These two techniques produce WSe2/SiC heterostructures with distinct differences due to interface states generated during the MOCVD growth process. This difference carries over to differences in band alignment from interface states and the ultra-thin nature of the MOCVD-grown material. Both heterostructures are not susceptible to proton-induced charging up to a dose of 1016 protons/cm2, as measured via shifts in the binding energy of core shell electrons and a decrease in the valence band offset. Furthermore, the MOCVD-grown material is less affected by the proton exposure due to its ultra-thin nature and a greater interaction with the substrate. These combined effects show that the directly grown material is suitable for multi-year use in space, provided that high quality devices can be fabricated from it.

  9. MoSbTe for high-speed and high-thermal-stability phase-change memory applications

    Science.gov (United States)

    Liu, Wanliang; Wu, Liangcai; Li, Tao; Song, Zhitang; Shi, Jianjun; Zhang, Jing; Feng, Songlin

    2018-04-01

    Mo-doped Sb1.8Te materials and electrical devices were investigated for high-thermal-stability and high-speed phase-change memory applications. The crystallization temperature (t c = 185 °C) and 10-year data retention (t 10-year = 112 °C) were greatly enhanced compared with those of Ge2Sb2Te5 (t c = 150 °C, t 10-year = 85 °C) and pure Sb1.8Te (t c = 166 °C, t 10-year = 74 °C). X-ray diffraction and transmission electron microscopy results show that the Mo dopant suppresses crystallization, reducing the crystalline grain size. Mo2.0(Sb1.8Te)98.0-based devices were fabricated to evaluate the reversible phase transition properties. SET/RESET with a large operation window can be realized using a 10 ns pulse, which is considerably better than that required for Ge2Sb2Te5 (∼50 ns). Furthermore, ∼1 × 106 switching cycles were achieved.

  10. Walking a high beam: the balance between employment stability, workplace flexibility, and nonresident father involvement.

    Science.gov (United States)

    Castillo, Jason T; Welch, Greg W; Sarver, Christian M

    2012-03-01

    Compared with resident fathers, nonresident fathers are more likely to be unemployed or underemployed and less likely, when they are employed, to have access to flexible work arrangements. Although lack of employment stability is associated with lower levels of father involvement, some research shows that increased stability at work without increased flexibility is negatively related to involvement. Using data from the Fragile Families and Child Wellbeing Study (N = 895), the authors examined the relationship between nonresident fathers' employment stability, workplace flexibility, and father involvement. Results indicate that workplace flexibility, but not employment stability, is associated with higher levels of involvement. Policy and practice implications are discussed.

  11. Yb-doped aluminophosphosilicate ternary fiber with high efficiency and excellent laser stability

    Science.gov (United States)

    Li, Yuwei; Peng, Kun; Zhan, Huan; Liu, Shuang; Ni, Li; Wang, Yuying; Yu, Juan; Wang, Xiaolong; Wang, Jianjun; Jing, Feng; Lin, Aoxiang

    2018-03-01

    By using chelate precursor doping technique and traditional modified chemical vapor deposition system, we fabricated Yb-doped aluminophosphosilicate (Al2O3-P2O5-SiO2, ternary Yb-APS) large-mode-area fiber and reported on its laser performance. The fiber preform was doped with Al, P and Yb with concentration of ∼8000 ppm, ∼1700 ppm and ∼400 ppm in molar percent, respectively. Tested with master oscillator power amplifier system, the home-made Yb-APS fiber was found to present 1.02 kW at 1061.1 nm with a high slope efficiency of 81.2% and excellent laser stability with power fluctuation less than ±1.1% for over 10 h. Compared with Yb-doped aluminosilicate (Al2O3-SiO2, binary Yb-AS) fiber, the introduction of P2O5 effectively suppressed photodarkening effect even the P/Al ratio is much less than 1, indicating that Yb-APS fiber is a better candidate for high power fiber lasers.

  12. High thermal stability of core-shell structures dominated by negative interface energy.

    Science.gov (United States)

    Zhu, Yong-Fu; Zhao, Ning; Jin, Bo; Zhao, Ming; Jiang, Qing

    2017-03-29

    Nanoscale core/shell structures are of interest in catalysis due to their superior catalytic properties. Here we investigated the thermal stability of the coherent core-shell structures in a thermodynamic way by considering the impact from the core with the bulk melting point T m (∞) lower or higher than the shell. When a low-T m (∞) core is adopted, core-shell melting induced by the melting depression of the core does not occur upon heating because of the superheating, although the melting depression of the core can be triggered ultimately by the preferential melting of the high-T m (∞) shell for small cores. The superheating of the core is contributed by the negative solid-solid interface energy, while the depression is originated from the positive solid-liquid interface energy. Owing to the presence of the negative interface energy, moreover, the low-T m (∞)-core structure possesses a low difference in thermal expansion between the core and the shell, high activation energy of outward atomic diffusion from the core to shell, and low heat capacity. This result is beneficial for the core-shell structure design for its application in catalysis.

  13. Chemical stability of a cold-active cellulase with high tolerance toward surfactants and chaotropic agent

    Directory of Open Access Journals (Sweden)

    Thaís V. Souza

    2016-03-01

    Full Text Available CelE1 is a cold-active endo-acting glucanase with high activity at a broad temperature range and under alkaline conditions. Here, we examined the effects of pH on the secondary and tertiary structures, net charge, and activity of CelE1. Although variation in pH showed a small effect in the enzyme structure, the activity was highly influenced at acidic conditions, while reached the optimum activity at pH 8. Furthermore, to estimate whether CelE1 could be used as detergent additives, CelE1 activity was evaluated in the presence of surfactants. Ionic and nonionic surfactants were not able to reduce CelE1 activity significantly. Therefore, CelE1 was found to be promising candidate for use as detergent additives. Finally, we reported a thermodynamic analysis based on the structural stability and the chemical unfolding/refolding process of CelE1. The results indicated that the chemical unfolding proceeds as a reversible two-state process. These data can be useful for biotechnological applications.

  14. Development of high stability hot mix asphalt concrete with hybrid binder

    Directory of Open Access Journals (Sweden)

    Toshiaki Hirato

    2014-12-01

    Full Text Available Cost reduction of public works projects has been desired due to severe financial circumstances. Therefore, asphalt pavement has been requested to extend its life. Semi-flexible pavement or epoxy asphalt pavement, which has high rutting resistance and oil resistance, may be applied to the place where these performances ae demanded. However, special technique is required in manufacturing and construction. In addition, these materials have also raised a problem that they cannot be recycled. Meanwhile, conventional asphalt pavement has several drawbacks. It is vulnerable to rutting caused by traffic load and damage caused by petroleum oils such as gasoline or motor oil. The materials used in asphalt mixtures were studied for improving the durability of asphalt mixture. A high stability asphalt concrete was developed which has equal or superior performance to semi-flexible pavement and epoxy asphalt pavement. In this paper, the process of selecting the substance and the characteristics evaluation of the developed mixtures ae described. Furthermore, an inspection result as well as follow-up survey of the performance of the developed mixtures obtained from trial and actual construction is shown.

  15. Understanding the High Ionic Conductivity in Nanostructured Ytterbium Stabilized Zirconia Thin Films

    Directory of Open Access Journals (Sweden)

    A. Benítez-Rico

    2015-01-01

    Full Text Available Recently, high ionic conduction has been reported in nanostructured materials. This increase in conductivity can be important in technological applications, including micro-Solid Oxide Fuel Cells, so the understanding of this phenomenon is essential. In this work, XRD, Raman spectroscopy, SEM, EDS maps, and UV-Visible spectroscopy measurements are used to have an insight into the relationship between structural and electrical properties in nanostructured ytterbium stabilized zirconia (YbSZ thin films prepared by ultrasonic spray pyrolysis. Raman measurements allowed the identification of a mixture of tetragonal and cubic phases at 4% of Yb doping, which cannot be detected by XRD, while the compositional maps suggest that Yb can be located preferentially in the grain boundaries. Changes in the activation energy values in bulk and grain boundaries are related to the small grain sizes (≤10 nm. UV measurements support the ionic nature of the charge transport. These results indicate that the high conductivity is a consequence of different physical parameters in the films such as stress in the materials, different crystalline phases, impurities diffusion to the grain boundaries, and the presence or absence of electronic conduction. A model that explains the increase of conductivity in nanostructured materials must include all these aspects.

  16. Edge-emitting InGaAs/GaAs laser with high temperature stability of wavelength and threshold current

    International Nuclear Information System (INIS)

    Gordeev, N Yu; Novikov, I I; Chunareva, A V; Il'inskaya, N D; Shernyakov, Yu M; Maximov, M V; Kalyuzhnyy, N A; Mintairov, S A; Lantratov, V M; Payusov, A S; Shchukin, V A; Ledentsov, N N

    2010-01-01

    We have investigated an edge-emitting tilted wave laser (TWL) with the active region based on GaInAs/GaAs quantum wells. In the TWL the wavelength stabilization is based on the coupling of the laser active waveguide cavity to a specially introduced thick epitaxial layer and the emission wavelength is defined by the combined cavity mode preferably by a single dominating mode. The TWL wafer has been grown by metal-organic chemical vapour deposition. Laser parameters have been investigated both in pulsed and CW mode in the temperature range of 15–60 °C. In the temperature window of 20–50 °C under CW excitation the lasers have shown high wavelength temperature stability with the temperature shift of 0.05 nm K −1 and threshold current stability with the characteristic temperature of 500 K. The data obtained prove the concept of thermal stability in tilted wave lasers

  17. Recruits of the stingless bee Scaptotrigona pectoralis learn food odors from the nest atmosphere

    Science.gov (United States)

    Reichle, Christian; Jarau, Stefan; Aguilar, Ingrid; Ayasse, Manfred

    2010-05-01

    The ability to learn food odors inside the nest and to associate them with food sources in the field is of essential importance for the recruitment of nestmates in social bees. We investigated odor learning by workers within the hive and the influence of these odors on their food choice in the field in the stingless bee Scaptotrigona pectoralis. During the experiments, recruited bees had to choose between two feeders, one with an odor that was present inside the nest during the recruitment process, and one with an unknown odor. In all experiments with different odor combinations (linalool/phenylacetaldehyde, geraniol/eugenol) a significant majority of bees visited the feeder with the odor they had experienced in their nest ( χ 2-tests; p food source during the recruitment process from the nest atmosphere and that their subsequent food search in the field is influenced by the learned odor.

  18. Odor impact of volatiles emitted from marijuana, cocaine, heroin and their surrogate scents

    Directory of Open Access Journals (Sweden)

    Somchai Rice

    2015-12-01

    Full Text Available Volatile compounds emitted into headspace from illicit street drugs have been identified, but until now odor impact of these compounds have not been reported. Data in support of identification of these compounds and their odor impact to human nose are presented. In addition, data is reported on odor detection thresholds for canines highlighting differences with human ODTs and needs to address gaps in knowledge. New data presented here include: (1 compound identification, (2 gas chromatography (GC column retention times, (3 mass spectral data, (4 odor descriptors from 2 databases, (5 human odor detection thresholds from 2 databases, (6 calculated odor activity values, and (7 subsequent ranking of compounds by concentration and ranking of compounds by odor impact (reported as calculated odor activity values. For further interpretation and discussion, see Rice and Koziel [1] and Rice [2].

  19. Multi-Sensor Integration to Map Odor Distribution for the Detection of Chemical Sources

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    2016-07-01

    Full Text Available This paper addresses the problem of mapping odor distribution derived from a chemical source using multi-sensor integration and reasoning system design. Odor localization is the problem of finding the source of an odor or other volatile chemical. Most localization methods require a mobile vehicle to follow an odor plume along its entire path, which is