Dissertations / Theses: 'Startle reaction'

1

Parker, Stephen David. "The effects of attention and stimulus onset asynchrony on the relationship between prepulse inhibition of the startle-eyeblink and prepulse-rating inhibition /." [St. Lucia, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16834.pdf.

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2

Smith, Cora. "Investigating the Role of the Primary Motor Cortex in the StartReact Effect Using Transcranial Magnetic Stimulation." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36638.

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It is well-established that the presentation of a startling acoustic stimulus (SAS) simultaneous with the go-signal in a simple reaction time (RT) task results in significant RT reductions, while leaving movement kinematics essentially unaltered. While this phenomenon, termed the StartReact effect, has been extensively studied, cortical involvement in the neural mechanism underlying the RT-facilitation effects of a SAS remains widely debated. Applying sub-threshold TMS to motor areas results in increased cortical excitability and reductions in control RT. When this technique was used in a startle paradigm no RT benefits were seen, providing evidence that the cortex may not be involved in the StartReact effect; however, these results may also have been due to a floor effect of startle RT. It has been shown that RT in response to a SAS is significantly slower for complex movements, providing a possible method of distinguishing between these hypotheses. As such, the purpose of the experiments in this thesis was to determine if the application of sub-threshold TMS following a SAS when preparing to react with a complex movement would facilitate startle RT. If so, it would provide evidence for cortical involvement in the RT-facilitation effects of startle. The first experiment revealed that the task employed did not lead to an increase in RT in startle conditions, limiting the ability to make conclusions regarding the StartReact effect. In the second experiment the timing complexity of the task was increased, with the goal of increasing startle RT; however, startle RT was again not significantly slower for the complex movement than the simple movement. Furthermore, there was again no effect of TMS stimulation condition on startle RT. These results suggest that either the cortex does not play a role in the StartReact effect, or a floor effect of RT was reached in startle conditions; thus, alternative methods of investigating the neural mechanism underlying the RT-facilitation effects of startle are warranted.

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3

Aitken, Christopher John. "Modulation of the startle reflex as a measure of cognitive bias in anxiety /." St. Lucia, Qld, 2000. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16465.pdf.

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4

Muthumani, Anburaj. "Study of startle/panic responses due to auditory and haptic warnings in roadway lane departure." Thesis, Montana State University, 2010. http://etd.lib.montana.edu/etd/2010/muthumani/MuthumaniA0510.pdf.

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Roadway lane departure accidents caused 25,082 fatalities which accounted for about 58 percent of all roadway fatalities in the United States this year (AASHTO, 2008). In order to reduce these fatalities different types of strategies were implemented such as providing shoulder and/or centerline rumble strips, enhancing delineation of sharp curves, removing or relocating objects, eliminating shoulder drop-offs and providing skid-resistant pavements. Of these strategies, the rumble strips strategy has been found to be more effective to warn drivers. But, the drawbacks of rumble strips have led to the introduction of in-vehicle warning systems. In-vehicle Lane Departure Warning Systems were machine vision-based that use algorithms to interpret video images to check the car's current position and time to lane crossing. However, it is not clear if the warnings themselves may be a potential hazard in terms of distracting or startling drivers. This distraction and startle might impede drivers from quickly and appropriately responding to the original traffic hazard. The present study is intended to better understand how human participants react to such sudden warnings given to them to warn in case of a possible hazard during roadway lane departure. Twelve participants (six male and six female) were asked to drive a simulated vehicle and they were alerted with auditory, haptic, combination of auditory & haptic and no-warning modalities during their lane departure. The responses of the participants were recorded using electromyography (EMG) from the deltoid, biceps brachii, pronator teres and tibialis anterior muscles. The results of the study determined that there is no significant difference in EMG activity between the warning modalities except for the deltoid muscle. The difference in EMG activity for the deltoid muscle for auditory condition is likely due to the greater maximum steering response. Moreover, there is no significant difference among warning modalities during the participant's first warning event. Also, there is no difference in EMG activity between genders due to warning modalities. Overall, findings suggest that there is no potential startle/panic response perceived by the participants due to warning systems in roadway lane departure.

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5

Poje, Albert Buddy Filion Diane L. "The effects of multiphasic prepulse stimuli on attentional modulation of prepulse inhibition of the acoustic startle eyeblink response." Diss., UMK access, 2007.

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Thesis (Ph. D.)--Dept. of Psychology. University of Missouri--Kansas City, 2007.
"A dissertation in psychology." Advisor: Diane L. Filion. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed July 16, 2008. Includes bibliographical references (leaves 109-118). Online version of the print edition.

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6

Hardwick, Sascha. "Startle modification during human fear conditioning : attention or emotion? /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19287.pdf.

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7

Howard, Samantha. "Identification facilitation from the attentional blink: a new paradigm for investigating the mechanisms that underlie repetition priming in word identification /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19242.pdf.

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8

Nelson, Jakob James Filion Diane L. "Startle eye-blink reflex as an index of emotion regulation in high and low monitors." Diss., UMK access, 2005.

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Thesis (Ph. D.)--Dept. of Psychology. University of Missouri--Kansas City, 2005.
"A dissertation in psychology." Advisor: Diane L. Filion. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed March 12, 2007. Includes bibliographical references (leaves 115-120). Online version of the print edition.

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9

Jones, Stephanie. "True or false? : associative priming in the attentional blink /." [St. Lucia, Qld.], 2006. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19777.pdf.

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10

Karnadewi, Fika. "Investigating the effect of meaning familiarity and ambiguity of words on the attentional blink /." [St. Lucia, Qld.], 2006. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19778.pdf.

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11

Miller, Kimberly M. "Diminished affective modulation of startle to threatening stimuli in parkinson's disease." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004851.

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Thesis (M.S.)--University of Florida, 2004.
Typescript. Title from title page of source document. Document formatted into pages; contains 65 pages. Includes Vita. Includes bibliographical references.

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12

Thompson, Alanda Katie. "Startle eyeblink modification : associations with Haloperidol, caffeine and nicotine in schizophrenia-spectrum and healthy individuals /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18998.pdf.

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13

Kędzior, Karina Karolina. "Chronic cannabis use and attention-modulated prepulse inhibition of the startle reflex in humans /." Connect to this title, 2004. http://theses.library.uwa.edu.au/adt-WU2004.0027.

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14

Lasher, Bonnie Ka Keele N. Bradley. "5,7-dihydroxytryptamine lesions of the rat amygdala increase learned fear behavior." Waco, Tex. : Baylor University, 2009. http://hdl.handle.net/2104/5302.

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15

Bonenfant, Marjolaine. "Escape and vocal responses of eastern chipmunks (Tamias striatus) to simulated aerial predator attack." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23989.

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The behaviours of eastern chipmunks (Tamias striatus) in response to aerial predators were studied in the field using trained kestrels (Falco sparverius) flying over a food patch where animals of known gender, age and burrow location categories were foraging. Their typical response was to flee toward a nearby refuge while producing a trill. After a few seconds, chipmunks usually emerged and started to produce long (but sometimes interrupted) series of chucks while facing the predator. Acoustical analysis showed that the trill consisted of a rapid series of usually high pitched and variable notes while most chucks consisted of two partially overlapping components differing mainly in frequency range. No differences were observed between individuals of different categories for most antipredator responses. Various observations suggest that the trill functions to startle the predator and that the chuck deters the predator from hunting in the area.

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O'steen, Jennifer Robin. "Prepulse Inhibition and the Acoustic Startle Response in Nine Inbred Mouse Strains." Scholar Commons, 2003. https://scholarcommons.usf.edu/etd/1443.

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This study examined the effects of genetic background on the acoustic startle response (ASR) and its modulation by prepulse inhibition (PPI) by comparing nine inbred strains of mice. The ASR, a jerk-like motor reflex, is elicited by bursts of noise or tones with sound pressure levels of 80-90 dB and greater. PPI is a type of modulation of the ASR, requires no training, and results in observable response in both mice and humans. Data were obtained from nine inbred mouse strains, sixteen per strain, which were shipped at approximately 3-5 weeks old from The Jackson Laboratory. In general, ASRs were generally smaller when the startle stimulus was less intense. PPI was relatively weak for the 4 kHz prepulse, and stronger with prepulses of 12 kHz and 20 kHz. However, means varied widely across strains for both ASR and PPI, suggesting a strong influence of genetic background on these behaviors. In addition to genetic influences, peripheral hearing loss and central auditory processing factors must be taken into consideration.

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17

Dalvald, Momo. "Korrelerar startlereaktion med reaktionstid?" Thesis, University of Gävle, Department of Education and Psychology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-321.

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Bilder av potentiella hot upptäcks snabbt och leder till en snabbare reaktionstid än bilder av icke-potentiella hot. Potentiella hot stjäl också fokus och kognitiva resurser, med en långsammare reaktionstid som följd. Rädsla, som kan mätas genom startlereflexen, leder till antingen ökad handlingsberedskap (snabbare reaktionstid) eller kognitiv distraktion (långsammare reaktionstid). Fem försöksdeltagare fick reagera på en visuell probe som lades ovanpå djurbilder, både potentiella hot och icke-potentiella hot i ett kombinerat reaktionstids- och startleprobeexperiment, där ljudstötar utdelades i hörlurar. Startlereaktion, hjärtfrekvens och reaktionstid mättes, varefter korrelationskoefficienter räknades ut. Resultatet visade på en svag negativ korrelation mellan reaktionstid och startlepotentiering på gruppnivå, men inga signifikanta samband påvisades på individnivå. Resultatet på gruppnivå kan bero på att de individuella resultaten tenderar samlas i kluster och därför skapar ett skensamband. Även en positiv korrelation mellan hjärtfrekvensförändring och startlereaktion påvisades, men ingen korrelation mellan hjärtfrekvens och reaktionstid.

Pictures of fear relevant animals are detected fast and lead to shorter reaction time, compared to pictures of fear irrelevant animals. Fear relevant animals also capture attention and steals focus, which leads to slower reaction time. Fear leads to either preparedness for action (faster reaction time) or cognitive distraction (slower reaction time). In a combined startle probe and reaction time experiment, five participants were requested to react to a visual probe, superimposed on pictures of animals, both relevant and irrelevant to fear. Startle probes were given as noise bursts in headphones. Startle reaction, heart rate and reaction time were measured. A negative correlation between reaction time and startle potentiation was found on group level, whereas no significant correlations were found on the individual level. However, the individual results tend to gather in clusters, which might give a significant result on group level even if there is none.

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18

Kedzior, Karina Karolina. "Chronic cannabis use and attention-modulated prepulse inhibition of the startle reflex in humans." University of Western Australia. School of Medicine and Pharmacology, 2004. http://theses.library.uwa.edu.au/adt-WU2004.0027.

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Background. Various studies show that cannabis use alters attention and cognitive functioning in healthy humans and may contribute to development of schizophrenia or worsening of pre-existing psychosis. However, the impact of cannabis use on brain function in humans is not well understood. Schizophrenia is associated with a deficit in prepulse inhibition (PPI), the normal inhibition of the startle reflex by a non-startling stimulus (prepulse), presented before the startle stimulus at short time intervals (lead-time intervals). Such PPI deficit is thought to reflect a sensorimotor gating dysfunction in schizophrenia. PPI is also modulated by attention and PPI reduction in schizophrenia is observed when patients are asked to attend to, not ignore, the stimuli producing PPI. The aim of the current study was to investigate the association between self-reported chronic cannabis use and attentional modulation of PPI in healthy controls and in patients with schizophrenia. Furthermore, the association between cannabis use and other startle reflex modulators, including prepulse facilitation (PPF) of the startle reflex magnitude at long lead-time intervals, prepulse facilitation of the startle reflex onset latency and habituation of the startle reflex magnitude, were examined. Method. Auditory-evoked electromyographic signals were recorded from orbicularis oculi muscles in chronic cannabis users (29 healthy controls and 5 schizophrenia patients) and non-users (22 controls and 14 patients). The data for 36 participants (12 non-user controls, 16 healthy cannabis users, and eight non-user patients) were used in the final analyses and the patient data were used as a pilot study, because relatively few participants met the rigorous exclusionary criteria. Participants were instructed to attend to or to ignore either the startle stimuli alone (70 100 dB) or prepulse (70 dB) and startle stimuli (100 dB) separated by short lead-time intervals (20 200 ms) and long lead-time intervals (1600 ms). In order to ignore the auditory stimuli the participants played a visually guided hand-held computer game. A pilot study showed that the response component of playing the game had no effects on attentional modulation of the startle reflex magnitude and onset latency. Results. Relative to controls, cannabis use in healthy humans was associated with a reduction in PPI similar to that observed in schizophrenia while attending to stimuli, and with an attention-dependent dysfunction in the startle reflex magnitude habituation. While ignoring the stimuli there were no statistical differences in PPI between cannabis users and controls, although PPI in cannabis users tended to differ from that of the patients. The reduction in PPI in cannabis users was correlated with the increased duration of cannabis use, in years, but not with the concentration of cannabinoid metabolites in urine or with the recency of cannabis use in the preceding 24 hours. Furthermore, cannabis use was not associated with any differences in PPF, onset latency facilitation, and startle reflex magnitude in the absence of prepulses. The accuracy of self-reports of substance use was also investigated in this study and was found to be excellent. In addition, the study examined the validity of the substance use module of the diagnostic interview, CIDI-Auto 2.1, which was found to be acceptable for cannabis misuse diagnoses (abuse and/or dependence). Finally, cannabis dependence was found to be associated with more diagnoses of mental illness other than schizophrenia (mainly depression). Conclusions. The results of the current study suggest that chronic cannabis use is associated with schizophrenia-like deficit in PPI in otherwise healthy humans. This PPI reduction is associated with attentional impairment rather than a global sensorimotor gating deficit in healthy cannabis users.

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19

Huntington, Lee. "The relation of spontaneous startles to cardiac and respiratory activity in newborn infants." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/53880.

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Previous studies have reported that spontaneous startles occur most frequently in the quiet sleep states, and have posited an energy release model in which spontaneous startles occur to release energy which would otherwise wake the infant. An alternative suggestion is that startles serve a homeostatic function by increasing the activity of the infant during periods of low arousal. The purpose of the current study was to examine the function of spontaneous startles using the ongoing cardiac and respiratory activity as indices of arousal. Twenty-six newborn infants were assigned to two groups. The first group was exposed to auditory stimulation which previously had been shown to decrease heart rate and respiratory rate for the first half of the one hour observation period. To the extent that spontaneous startles are related to periods of low arousal, decreasing the ongoing activity via the auditory intervention was expected to increase the rate of startles. The second group received no auditory stimulation. The occurrence of spontaneous startles was preceded by periods of lower than average heart rate and decreasing respiratory rate. Startles were followed by periods of increasing heart rate and further decreasing respiratory rate. In addition, the auditory intervention group reliably showed both a lower heart rate and an increased number of startles while exposed to the auditory stimulation, while the nonintervention group showed comparable rates of startles and heart rates in both halves of the observation period. Further, regardless of group status, most infants had their higher rate of startles in the period in which they had their lower heart rate. Finding lower heart rate and decreasing respiratory rate preceding startles, and lower heart rate and increased number of startles when exposed to the auditory stimulation, suggests that spontaneous startles modulate periods of low arousal in newborn infants.
Ph. D.

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20

Knox, Aaron James. "The GART gene of purine biosynthesis : assessment of functional sites through mutagenesis in CHO cells and analysis of behavioral phenotypes in transgenic mice /." Connect to full text via ProQuest. Limited to UCD Anschutz Medical Campus, 2007.

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Thesis (Ph.D. in Human Medical Genetics) -- University of Colorado Denver, 2007.
Typescript. Includes bibliographical references (leaves 141-157). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;

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21

Alsrhani, Abdullah Falleh. "Studies in Trypsin as an Alarm Substance in Zebrafish." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1248500/.

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Previous studies have shown that fish release alarming substances into the water to alert their kin to escape from danger. In our laboratory, we found that zebrafish produce trypsin and release it from their gills into the environment when they are under stress. By placing the zebrafish larvae in the middle of a small tank and then placing trypsin at one end of the tank, we observed that the larvae moved away from the trypsin zone and almost to the opposite end of the tank. This escape response was significant and did not occur in response to the control substances, bovine serum albumin (BSA), Russell's viper venom (RVV), and collagen. Also, previously, we had shown that the trypsin could act via a protease-activated receptor-2 (PAR2) on the surface of the cells. Therefore, we hypothesized that trypsin would induce a change in neuronal activity in the brain via PAR2-mediated signaling in cells on the surface of the fish body. To investigate whether the trypsin-responsive cells were surface cells, we generated a primary cell culture of zebrafish keratinocytes, confirmed these cells' identity by specific marker expression, and then incubated these cells with the calcium indicator Fluo-4 and exposed them to trypsin. By using calcium flux assay in a flow-cytometer, we found that trypsin-treated keratinocytes showed an increase in intracellular calcium release. To test whether PAR2 mediates the escape response to trypsin, we treated larvae with a PAR2 antagonist and showed that the trypsin-initiated escape response was abrogated. Furthermore, par2a mutants with knockdown of par2a by the piggyback knockdown method failed to respond to trypsin. Trypsin treatment of adult fish led to an approximately 2-fold increase in brain c-fos mRNA levels 45 mins after trypsin treatment, suggesting that trypsin signals may have reached the brain, probably via a spinothalamic pathway. Taken together, our results reveal a novel trypsin-initiated escape response in fish. These studies should enhance our understanding of fish communication in general and alarm behavior in particular. Furthermore, since pain receptors in other animals are also PAR2, our finding may be useful in exploring pathways of pain reception.

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Manion, Sean T. "Amygdala, anxiety & alpha-1 adrenoreceptors : investigations utilizing a rodent model of traumatic stress /." Download the thesis in PDF, 2006. http://www.lrc.usuhs.mil/dissertations/pdf/Manion2006.pdf.

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23

Tidwell, Kyle Scott. "Quantifying the Impacts of a Novel Predator: the Distinctive Case of the Oregon Spotted Frog (Rana pretiosa) and the Invasive American Bullfrog (Rana (Aquarana) catesbeiana)." Thesis, Portland State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10259428.

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The decline of the Oregon Spotted Frog (Rana pretiosa), a Pacific Northwest endemic now federally listed as threatened, has been attributed to several aspects of ecosystem alteration, primarily habitat degradation and loss. The introduced American Bullfrog (Rana (Aquarana) catesbeiana ) has been widely implicated in those declines, but the basis of that contention has been difficult to characterize. The bullfrog occurring at every site of recent Oregon Spotted Frog extirpation has focused concern about its impact.

Here, I present a suite of interconnected studies that examine the behavioral ecology of both species to better understand the potential for bullfrog-mediated Oregon Spotted Frog extirpation. I quantified Oregon Spotted Frog anti-predator behavior from the only known population successfully co-occurring with bullfrogs (Conboy Lake) and a population devoid of bullfrog impact (Big Marsh), and compared these behaviors to the predatory traits of the bullfrog. The initial study revealed that captive-reared individuals from the Oregon Spotted Frog population that has successfully co-occurred with bullfrogs respond faster to a predatory stimulus (measured as latency to response) than Oregon Spotted Frogs from a population not to exposed to bullfrogs. Subsequent field investigations of the approach distance allowed by a predator stimulus before taking evasive action (termed the flight initiation distance: FID) conducted with the Oregon Spotted Frog population co-occurring with bullfrogs first demonstrated that FID of recently metamorphosed bullfrogs is consistently greater than that of recently metamorphosed Oregon Spotted Frogs. Further, examination of FID across all post-metamorphic age classes of Oregon Spotted Frogs revealed that older frogs do not allow as close approach as recently metamorphosed Oregon Spotted Frogs. This age class shift in FID did not occur in the Oregon Spotted Frog population not exposed to bullfrogs. In the latter population, FID did not differ among age classes.

Since the bullfrog might be driving this age-based change in anti-predator behavior, I explored the variation in strike distance of bullfrogs from the site of co-occurrence in both the field and laboratory to determine the extent of overlap with Oregon Spotted Frog FID. I found that the bullfrog strike distance significantly overlaps the FID of all ages of Oregon Spotted Frogs from the bullfrog-free site but only that of youngest (recently metamorphosed) frogs at the site of co-occurrence. Older Oregon Spotted Frogs from the site of co-occurrence generally escaped at distances greater than the strike distance of bullfrogs.

I also collected > 880 bullfrogs from the site of co-occurrence and analyzed the stomach contents to assess their dietary trends. I found that bullfrogs consume Oregon Spotted Frogs at the site, but do not eat the larger (older) frogs. Moreover, the body size ratio between Oregon Spotted Frogs as prey and bullfrogs as predators suggests that nearly all of the adult size distribution of bullfrogs at Conboy would be incapable of preying on adult Oregon Spotted Frogs.

Collectively, these studies strongly suggest that bullfrogs have altered the escape behavior of Oregon Spotted Frogs at Conboy Lake and that most adult Oregon Spotted Frogs at Conboy may have a size-based release from predation by bullfrogs. Implicit in this finding is that bullfrogs may pose a real threat via predation to other Oregon Spotted Frog populations with which they might come into contact where the distribution of bullfrog body sizes differ substantially from that at Conboy Lake.

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Phillips, Jennifer M. "Effects of clozapine and alprazolam on cognitive deficits and anxiety-like behaviors in a ketamine-induced rat model of schizophrenia /." Download the dissertation in PDF, 2005. http://www.lrc.usuhs.mil/dissertations/pdf/Phillips2005.pdf/.

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Astrin, Cal D. "Startup control of the TOPAZ-II space nuclear reactor." Thesis, Monterey, California. Naval Postgraduate School, 1996. http://hdl.handle.net/10945/9006.

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Approved for public release; distribution isunlimited.
The Russian designed and manufactured TOPAZ-II Thermionic Nuclear Space Reactor has been supplied to the Ballistic Missile Defense Organization for study as part of the TOPAZ International Program. A Preliminary Nuclear Safety Assessment investigated the readiness to use the TOPAZ-II in support of a Nuclear Electric Propulsion Space Test Mission (NEPSTP). Among the anticipated system modifications required for launching the TOPAZ-II system within safety goals is for a U.S. designed Automatic Control System. The requirements and desired features of such a control system are developed based upon U.S. safety standards. System theory and design are presented in order to establish the basis for development of a hybrid control model from available simulations. The model is verified and then used in exploration of various control schemes and casualty analysis providing groundwork for future Automatic Control System design.

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SAUER, MARIA E. L. J. "Analise dos procedimentos de partida do reator IEA-R1: uma aplicacao da tecnica HazOp." reponame:Repositório Institucional do IPEN, 2000. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10793.

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Made available in DSpace on 2014-10-09T12:44:05Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T13:56:59Z (GMT). No. of bitstreams: 1 06869.pdf: 6244553 bytes, checksum: e1b373e9de3f0d1846ccc32627f81959 (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Tenorio, Doris Ortilla. "Enhancing start-up of a UASB reactor with centrifuged sludge." Thesis, Tenorio, Doris Ortilla (1995) Enhancing start-up of a UASB reactor with centrifuged sludge. PhD thesis, Murdoch University, 1995. https://researchrepository.murdoch.edu.au/id/eprint/52414/.

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Start-up is one major problem that has been identified in the operation of UASB and other high rate anaerobic systems. This is related to the availability of seed material and the time required to develop the required high bacterial biomass. At present it is difficult to obtain a large amount of seed material to start-up a full scale UASB reactor because full scale operational reactors are located in only a limited number of places. Therefore the use of other seed materials is essential. In this thesis start-up of UASB reactors using abattoir wastewater stabilisation pond sludge was examined. Enhancing the rate of start-up with non-granular sludge is consequently a problem, because the dispersed nature of non-granular sludge limits its amount within a reactor making it easier to washout. This can result in a long period of start-up because the organic loading is highly dependent on the amount of sludge in the reactor. The use of centrifuged sludge may overcome this problem. It was hypothesised that the solids particles would be agglomerated and this would improve sludge retention, resulting in a greater number of the right type of microorganisms retained in the reactor. A study was carried out to examine the feasibility of using centrifuged sludge in the start-up of UASB reactors to test the above hypothesis and to follow the development of the sludge during start-up. Three sets of experiments were carried out. The first set of experiments was employed to determine if the methanogenic activity of abattoir wastewater stabilisation pond sludge deteriorated due to centrifugation. Initially the sludge from different ponds in the treatment facilities was tested for methanogenic activity. The results show that the best source of sludge was the third pond in a series of 3. The amount of methane producing bacteria was estimated and found to constitute around 13% of volatile suspended solids. The sludge from pond 3 was then subjected to centrifugation and tested for methanogenic activity. The results show that the methanogenic activity of centrifuged sludge was similar to non-centrifuged sludge. The results clearly indicate that centrifugation did not affect the activity of the microbial population. The effect of non-centrifuged and centrifuged sludge on UASB start-up was tested in the second set of experiments. The overall results show that centrifuged sludge was better than non-centrifuged sludge in the start-up of UASB reactor. The performance of centrifuged sludge was more consistent when compared to non-centrifuged sludge. The average COD removal obtained at the end of these experiments was 80% ± 10% for centrifuged sludge and 56% ± 32% for non-centrifuged sludge. The difference in performance was related to the better retention of centrifuged sludge in the reactor, because it occupied less space and the agglomerated particles were not easily dispersed at the onset of operation. The retention of centrifuged sludge consequently resulted in a high number of bacteria in the reactor. Estimation of bacterial numbers in the sludge was carried out using several methods, with scanning electron microscopy (SEM) found to be the more appropriate. The SEM micrograph also revealed that the microbial population in the seed material influenced the selection and predominant growth of bacteria in the reactor during start-up. The sludge developed was mainly composed of filamentous type of bacteria (probably Methanothnx) which was initially present in the seed material. Although the sludge developed in the reactor was not granulated, its settleability was high. In the third set of experiments the parameters affecting the use of centrifuged sludge in the start-up of UASB reactors were studied. The results established that the rate of start-up was enhanced by using a high initial sludge concentration but was limited to 30 g VSS/L of reactor, mainly because of excessive solids washout in the reactor configuration employed. A COD loading of 15 g/L of reactor-day was attained within a period of 3 weeks with 79% COD reduction. Start-up did not appear to be greatly affected by starting with either high HRT (24 hr and high strength feed) or low HRT (6 hr and low strength feed). The results also showed that the growth of predominant bacteria was affected by the initial amount of sludge used in start-up as well as organic loading. The predominant growth of bacteria (morphologically of the Methanosarcina type) was observed in reactors initially containing 10 g VSS/L of reactor. A mixture of bacteria (morphologically of the Methanosarcina and Methanothrix type) was observed in reactors containing 30 to 60 g VSS/L of reactor. The present study indicates that non-granular sludge can be concentrated by centrifugation without affecting the activity of the microbial population, and the use of centrifuged sludge is an option to enhance the rate of UASB start-up. A high number of bacteria are retained in the reactor and this allows a high loading condition in a short period of time. The strategy for start-up is to inoculate a UASB reactor with 30 g VSS/L of reactor of centrifuged sludge, and then to operate starting from a low HRT (12 hr) and decreasing it stepwise down to 4 hr with a low strength feed.

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Shizas, Ioannis. "Start-up of a laboratory-scale anaerobic sequencing batch reactor treating glucose." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0015/MQ49734.pdf.

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Liedström, Kvelland Max. "Designing Towards a Unique Value Proposition : Iterating Using the Directed Product Reaction Method: A Case Study." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-95454.

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Lean Startup lacks a method specifically designed to evaluate whether a HCI-design is fulfilling the promises delivered by the unique value proposition (UVP). At the time of writing, concurrent think aloud protocols during usability testing and interviews are used to that end. There are, however, a couple of issues bundled with the use of such methods. Using a case study conducted on two iterations of high-fidelity prototypes of a meal planning website currently in development, a method called Directed Product Reaction (DPR) is proposed. DPR is a result of the adaptation of Product Reaction Cards, and the addressing of issues uncovered during case study iterations. DPR aspires to be that specifically designed method needed for assessment of user experience in relation to UVP in Lean Startup, and while the resulting method proposed has far from achieved that goal, it serves as a foundation moving forward.

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Gros, Emilien B. "Liquid-Salt-Cooled Reactor start-up with natural circulation under Loss-of-Offsite-Power (LOOP) conditions." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43745.

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The Liquid-Salt-Cooled Very High-Temperature Reactor (LS-VHTR) was modeled using the neutronics analysis code SCALE6.0 and the thermal-hydraulics and kinetics modeling code RELAP5-3D with objective to devise, analyze, and evaluate the feasibility and stability of a start-up procedure for this reactor using natural circulation of the coolant and under the Loss Of Offsite Power (LOOP) conditions. This Generation IV reactor design has been studied by research facilities worldwide for almost a decade. While neutronics and thermal-hydraulics analyses have been previously performed to show the performance of the reactor during normal operation and for shutdown scenarios, no study has heretofore been published to examine the active or passive start-up of the reactor. The fuel temperature (Doppler) and coolant density coefficient of reactivity of the LS-VHTR were examined using the CSAS6 module of the SCALE6.0 code. Negative Doppler and coolant density feedback coefficients were calculated. Two initial RELAP5 simulations were run to obtain the steady-state conditions of the model and to predict the changes of the thermal-hydraulic parameters during the shutdown of the reactor. Next, a series of step reactivity additions to the core were simulated to determine how much reactivity can be inserted without jeopardizing safety and the stability of the core. Finally, a start-up procedure was developed, and the restart of the reactor with natural convection of the coolant was simulated. The results of the simulations demonstrated the potential of a passive start-up of the LS-VHTR.

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Parra, S. A. (Santiago Ariel). "Simulating light-water-reactor start-up transients using a point-kinetics model with a precalculated reactivity-table." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/35951.

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32

King, Kristen A. "Primary caregivers' reactions to their Head Start preschoolers' negative emotions predicting emotion competence and social competence in a low-income, ethnic minority sample /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 0.51 Mb., 74 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:1435915.

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Nery, Valéria Del. "Utilização de lodo anaeróbio imobilizado em gel no estudo de partida de reatores de fluxo ascendente com manta de lodo." Universidade de São Paulo, 1987. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-05122016-090836/.

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A utilização de reatores anaeróbios de fluxo ascendente com manta de lodo no tratamento de águas residuárias tem tido grande aceitação dos projetistas e pesquisadores pelas vantagens que esse sistema apresenta sobre os demais (aeróbios e anaeróbios). Uma das principais limitações do processo relaciona-se com o período de partida, normalmente lento e de difícil controle. Esse trabalho apresenta os resultados de pesquisas em laboratório sobre a partida de dois reatores de manta de lodo, um deles inoculado com lodo anaeróbio imobilizado em matrizes de gel agar e o outro com lodo livre. A imobilização de microrganismos em gel surge como uma nova possibilidade de retenção da população microbiana no reator e consequentemente, esse trabalho objetiva também verificar a viabilidade do uso de lodo imobilizado em qel agar no estudo sobre fatores que afetam o desempenho de reatores com manta de lodo. Os dois reatores anaeróbios utilizados neste trabalho eram idênticos e possuiam volume de 10 L cada um. Utilizou-se substrato sintético para que se obtivesse alimento com características estáveis durante a maior parte do tempo necessário à partida dos reatores, preparados de maneira a se obter DQO de aproximadamente 2000 mg/L. Os reatores estiveram em operação durante 179 dias e foram submetidos a cargas orgânicas volumétricas que variaram de 0,47 a 12,83 KgDQO.m-3.d-1 e a cargas hidráulicas volumétricas que variaram de 0,23 a 6,0 m3.m-3.d-1. As principais análises realizadas foram DQO, alcalinidade, ácidos voláteis, pH, temperatura e altura do leito de lodo. A eficiência de remoção de DQO esteve em geral entre 70 e 80%. Em vista dos resultados obtidos, conclue-se que a utilização de lodo anaeróbio imobilizado em matrizes de gel agar pode ser útil no estudo de partida de reatores anaeróbios com manta de lodo. Sugere-se a continuidade dos estudos, utilizando-se as técnicas descritas no trabalho, na ampliação do conhecimento dos processos anaeróbios neste tipo de reator.
The use of Upflow Anaerobic Sludge Blanket (UASB) Reactor for wastewater treatment has been well accepted by designers and researchers due to the advantages shown over athers reactors (aerobic and anaerobic). The reactor start-up remains as one of the most important limitations of the process. It is usualy slow and is difficult to control. This thesis shows the results of a laboratory research on the start-up of two UASB reactors. One of them was seeded with anaerobic sludge immobilized in gel agar and the other with free anaerobic sludge. The immobilization of microorganisms in gel represents a new possibility of biomass retention within the reactors. Consequently this research also aims to check the viability of using immobilized sludge in gel agar in the study of factors affecting UASB reactors performance. Both the UASB reactors used in this research were exatly alike and had a volume 10 L each. Synthetic substrate was used to provide, consistent feed during the most of the start-up period. The substrate was prepared to contain about 2000 mg/L COD. The reactors were aperated for 179 days and were submitted to organic loading rates which varied from 0,47 to 12,83 KgCOD.m-3.d-1 and to hydraulic loading rates which varied from 0,23 to 6,0 m3.m-3.d-1. The main physical-chemical parameters measured were COD, alkalinity, volatite fatly acids, pH, temperature and sludge bed height. The COD removal efficiency was between 70 and 80%. This research comproved the feasibility of sludge immobilized in gel agar for UASB reactor start-up. It is suggested to continue the studies to achieve the best conditions for the use of this technique.

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Kwon, Saerom. "Study on tritium production property by D-T and D-D neutrons of LiPb blanket for fusion reactor." Kyoto University, 2014. http://hdl.handle.net/2433/188826.

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Godoy, Thais Gorga de. "Biofiltro aerado submerso aplicado ao pós-tratamento de efluente de reator UASB, sob condições hidráulicas desfavoráveis: estudo em escala real." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-06112007-095312/.

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Esta pesquisa avaliou a eficiência do biofiltro aerado submerso empregado no pós-tratamento do efluente do reator anaeróbio de manta de lodo (UASB), em escala real, localizado na ETE Água Vermelha em São Carlos, SP, sob condições hidráulicas desfavoráveis. Estudou-se a remoção de matéria orgânica e de sólidos, a possibilidade de remoção de nitrogênio e fósforo e também as características da biomassa aderida ao meio suporte. O estudo foi desenvolvido em duas fases, uma sem a adição de inóculo (fase I) e outra com inoculação (fase II). Na fase I foi aplicada vazão de 380 m³/dia, cargas orgânicas volumétricas (COV) de 3kgDQO/m³.dia com carga hidráulica (CH) de 8 m³/m².dia e tempo de detenção hidráulica (TDH) de 170 minutos. Nesta fase o biofiltro alcançou eficiências médias de 40% na remoção de matéria orgânica (DQO) e de 35% para os SST. Na segunda fase foram aplicadas vazões de 500 m³/dia, COV de 4 kg DQO/ m³.dia com CH de 11 m³/ m².dia e TDH de 130 minutos. O BAS apresentou eficiências médias de remoção de DQO, \'COT IND.F\' e SST de 36%, 60% e 30%, respectivamente, para a fase II. A conversão de nitrito a nitrato foi considerada desprezível, podendo ser atribuída ao alto valor de DQO afluente ao BAS, à ocorrência de nitrificação e desnitrificação no mesmo biofilme e à distribuição ineficiente de ar no interior do reator. O biofiltro não apresentou bons resultados quanto à remoção de fósforo durante a pesquisa. O estudo permitiu concluir que o BAS apresentou um desempenho satisfatório como unidade de pós-tratamento de reator UASB na fase de partida, mesmo sendo submetido a altas cargas hidráulicas e orgânicas. Constatou-se, portanto, que o emprego do biofiltro aerado submerso apresenta-se como uma alternativa vantajosa para o pós-tratamento do efluente de reatores anaeróbios, produzindo um efluente de excelente qualidade.
This research evaluated the efficiency of a full scale submerged aerated biofilter (SAB) used for post-treatment of the effluent of an upflow anaerobic sludge blanket (UASB) reactor, located in the wastewater treatment plant Água Vermelha (São Carlos, SP, Brazil), under unfavorable hydraulic conditions. The removal of organic matter and solids, the possibility of removal of nitrogen and phosphorus and also the characterization of biomass attached to the packing media were studied. This study vas developed in two phases, one without reactor seeding (phase I), and another when the reactor was seeded (phase II). At phase I, a flow rate of 380 m³/d and a volumetric loading rate of 3 kgCOD/m³.d with hydraulic load (HL) of 8 m³/m².d were applied, with 170 minutes of hydraulic retention time (HRT). In this phase the biofilter reached average efficiencies of 40% in organic matter removal (COD) and 35% for TSS. Already in phase II, a flow rate of 500 m³/d, a volumetric loading rate of 4kgCOD/m³.d with HL of 11 m³/ m².dia were applied, with 130 minutes of HRT. The SAB allowed average removal efficiencies of COD, \'TOC IND.F\' and TSS of 36%, 60% and 30%, respectively, for phase II. The conversion of nitrite to nitrate was considered worthless, likely attributed to the high value of affluent COD to the SAB, the occurrence of nitrification and denitrification in the same biofilm and the inefficient air distribution in the interior of the reactor. The biofilter did not present good results in phosphorus removal. This study allowed to conclude that the aerated submerged biological filter presented a satisfactory performance as a post-treatment unit of an UASB reactor during the start-up phase, being submitted to high hydraulic and organic loads. It was found that the employment of the submerged aerated biofilter is an advantageous alternative as anaerobic effluent post-treatment, producing excellent quality effluent.

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Carlsen, Anthony Nigel. "Auditory startle response and reaction time." 2003. http://www.oregonpdf.org.

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Carlsen, Anthony Nigel. "Auditory startle reponse and reaction time." Thesis, 2003. http://hdl.handle.net/2429/14075.

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Recent experiments involving the use of a startling acoustic stimulus during a simple reaction time (RT) task have shown that premotor RT (PMT) can be significantly reduced when participants are startled (Valls-Sole et al., 1999; Carlsen et al., in press). This effect is not produced by an early startle reflex adding on to a later voluntary response, as EMG profiles remain largely unmodified. Further, the lack of an effect of the startle on final position and aiming accuracy suggests that the response produced is indeed the prepared response. These findings suggest that a startle stimulus may act to trigger a prepared movement earlier in comparison to voluntary initiation (Carlsen et al., 2000). It has been shown that individuals habituate to a startling stimulus at different rates depending on the required activity level of the participant in the task (Brown et al., 1991a; Siegmund et al., 2001). The aim of the first study of this thesis was to determine the rate at which participants habituate to a startle during the completion of a RT task. Participants performed a targeted wrist extension in a Simple RT task. An auditory startle stimulus (124 dB) replaced the imperative stimulus in some of the trials. For the duration of the experiment, startle response electromyographic (EMG) activity continued to be produced, but not on every startle trial, indicting habituation was not complete after 20 startle trials. PMT in the startle (ST) condition was significantly shorter than control PMT however, within the ST condition, when a measurable EMG burst in the SCM was present, PMT was significantly shorter than when no SCM burst was present. It has been suggested that a startling stimulus activates structures in the lower CNS that are common to both the startle and voluntary response pathways, acting trigger a preprogrammed movement (Valls-Sole et al. 1999). In a Choice RT paradigm, however, it is thought that cortical processing must occur before a response can be prepared, since the appropriate response is not known in advance (Schluter et al., 1998 Schluter et al., 2001). The second experiment of the thesis addressed the issue of response preparation through the use of a Choice RT paradigm. Participants performed targeted wrist flexion / extension movements involving 1, 2, or 4 Stimulus-response (S-R) alternatives. Results showed that while in the Simple RT situation PMT was significantly shorter when participants were startled, that no difference in PMT was observed when participants were startled in the Choice RT situations. Furthermore, more errors occurred when participants were startled during the Choice RT conditions suggesting that the startle may actually interfere with ongoing cortical processes. These results support the hypothesis that a startle acts to trigger a prepared response, rather than only increasing systemic activation.

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Holmqvist, Mats Harald. "Visually evoked escape of flies : a behavioral and electrophysiological analysis." Phd thesis, 1993. http://hdl.handle.net/1885/143995.

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39

Jennings, Marilyn Elizabeth Kline John Patrick. "Emotion regulation in borderline personality disorder a psychophysiological examination of emotional responding and recovery in BPD /." 2003. http://etd.lib.fsu.edu/theses/available/etd-09012003-013813/.

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Thesis (Ph. D.)--Florida State University, 2003.
Advisor: Dr. John Patrick Kline, Florida State University, College of Arts and Sciences, School of Psychology. Title and description from dissertation home page (viewed Oct. 6, 2003). Includes bibliographical references.

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40

Příplatová, Lenka. "Vliv toxoplasmosy na reakční časy a prepulsní inhibici úlekových reakcí u člověka." Doctoral thesis, 2019. http://www.nusl.cz/ntk/nusl-411951.

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Effects of Toxoplasmosis on Reaction Times and Prepulse Inhibition of Startle Reaction in Humans vi Abstract Toxoplasma gondii, a single-cell coccidia from almost exclusively parasitic phylum Apicomplexa, does not typically cause acute health issues in humans with most exceptions among immunodeficient individuals and pregnant mothers or, more precisely, their offspring. In the latent phase, the bradyzoites in tissue cysts placed most often in neural and muscle tissues can evolve pressure on the host's body both as a collateral effect of the presence of the parasitic organism in host's tissues and as a consequence of adaptive evolution leading to increase in probability of trophic transmission to the final host, a felid. In humans, this can result in slight changes in personality profiles, deterioration of psychomotor and cognitive functions, and development of serious mental disorders. The thesis focuses predominantly on one of the aspects of the changes, namely the effect of latent toxoplasmosis on the processing of startle signals themselves and when modified by a preceding low-intensity signal; this processing may be connected with the development of schizophrenia in predisposed individuals. Studies conducted within the project framework found changes int the speed of signal processing in...

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Příplatová, Lenka. "Úleková reakce u osob s latentní toxoplasmosou." Master's thesis, 2011. http://www.nusl.cz/ntk/nusl-312746.

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Possible connection between latent toxoplasmosis and schizophrenia is a very interesting and medically important topic. In this thesis I tried to map current state of knowledge in the interdisciplinary research of schizophrenia and Toxoplasma gondii and their possible connections as well as to show differences in responses between Toxoplasma-positive and Toxoplasma-negative subjects using simple computer-administered tests of prepulse inhibition of startle reaction (PPI). Such differences would suggest another similarity between schizophrenia patients and subjects with latent toxoplasmosis as the sensorimotor gating responsible for PPI was found to be disrupted in schizophrenia patients. Side goal of the study was to test newly developed PC software for testing PPI and to determine its applicability in further research. Subjects for the tests were recruited among adepts of professional military service; 409 subjects completed the test of acoustic PPI and 276 subjects completed the test of visual PPI. All the subjects were tested on presence of specific anti-Toxoplasma IgG in their blood serum. Both tests revealed significant (p<0.001) differences between responses on prepulse-preceded stimuli and plain stimuli without prepulse, no significant results were, however, gained for the effects of latent...

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Matthews, Christopher. "Analysis of the antineutrino rate during CANDU reactor startup." Thesis, 2012. http://hdl.handle.net/1957/27973.

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Detection systems used to monitor reactor operations are of significant interest as tools for verification of operator declarations. Current reactor site safeguards are limited to visual inspections and intrusive monitoring systems. The recent development of antineutrino detectors may soon allow real-time monitoring from an unobtrusive location. Antineutrinos are produced through beta decay of fission products in the core. The lack of charge and small mass of the antineutrino ensures an extremely low interaction probability with all matter, effectively making the particle impossible to shield. As the fuel isotopic composition changes with burn-up, the primary fission source changes from ²³⁵U to ²³⁹Pu. Since differing antineutrino energy spectra are produced by each fissionable isotope, the antineutrino flux will also change as a function of burn-up. Supported by reactor simulations from nuclear codes, antineutrino detectors may provide a window into the reactor core and provide inspectors with tools to verify legitimate operations. This thesis is focused on the antineutrino rate produced by CANadian Deuterium Uranium reactors (CANDU) during startup. A CANDU fuel bundle model was created with the TRITON module from the SCALE6.1 code to calculate isotopic antineutrino rates for a single bundle. A full core CANDU model that incorporates refueling was also created for the first 155 days of operation after startup by using a Python 2.6 script to handle pre- and post-calculations. All simulations were calculated using operational data from Point Lepreau Generating Station produced by proprietary codes for the forthcoming fresh core startup. Dependence of the antineutrino rate on power and bundle replacement was analyzed, with a ±10% change in power causing a ±10% change in antineutrino rate, and the CANDU detector effectively measuring a 10% decrease in power within 9 hours of collection time. Bundle refueling was shown to only slightly modify the antineutrino rate, requiring a target volume more than 20 times larger than the present detector to effectively identify the change due to the bundles refueled over a one week period. Diversion of 15% or more of the total amount of bundles can be effectively measured by the CANDU detector within a one month counting period.
Graduation date: 2012

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Hung, Yu-Shin, and 洪有信. "Optimal Startup Policies of Reactive Distillation Processes: Methyl Acetate v.s. Butyl Acetate." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/84745114191108242994.

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碩士
國立臺灣科技大學
化學工程系
104
The startup of a distillation column involves the control of complex heat and mass transfer operations, and a wide range of operating conditions, represents one of the most complicated dynamic operations in the chemical industry. The startup procedure is time and energy consuming and the process is unproductive during this transient period before the steady state. It is desirable to reduce the transient period and consequently the startup time. This work proposes the optimization of startup for two kinds of reactive distillation (RD) processes: methyl acetate and butyl acetate. With these two processes, different startup procedures and optimal initial charge policies have been investigated in this research. Unlike the startup of a conventional distillation, two reactants will feed into the RD column. Furthermore, reaction will take place in the reactive zone. Therefore, the initial charge policy will be an important operation to shorten the startup period. In this research, there are four to five initial charge policies would be considered to find the shortest startup period by using simulated annealing approach for each processes. Results show that combination of simulated annealing approach (SA) and dynamic simulation, the best initial charge policy of methyl acetate process is methyl acetate charging into reflux drum and feed both reactants into sump first. Because top of the column earlier reach steady state. Furthermore, the optimal startup time period can be shortened 8.91 h than the case we feed both reactants into column in the same time. And the total energy requirement is 11.5 GJ. The result of butyl acetate process quite similar even it contains additional decanter. The best initial charge policy of this process is water charging into reflux drum and feed both reactants into sump first. Although its startup time increase approximately 0.48 hours, total energy requirement increase approximately 1.8 %, but entire startup process can be improved significantly by using SA to find the optimal reboiler duty increase path.

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cheng, Lin min, and 林明正. "Start-up and Operation of Anerobic Hydrogen Production continuous Flow Stirred Tank Reactor (CSTR) Reactor." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/91756119041248745453.

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碩士
逢甲大學
土木及水利工程研究所
88
the isolation pH 3. Hydrogen gas was not detected at cultivation pH 5. In acid isolation experiment, the optimum hydrogen production efficiency was at cultivation pH 7. In base isolation experiment, the highest hydrogen production efficiency was occurred at cultivation pH 6. These results indicate that, the initial cultivation medium pH of hydrogen production ranged from 6 to 7. The carbon source was sucrose in the continuous experiments. Three continuous stirred tank reactors were seperatedly inoculated with Bean sludge, Limin sludge and Nato sludge. Hydrogen production rate in the pH control process was better than that of pH uncontrol. In the pH control process, pH was controlled at 6.7. Hydrogen production rates of hydraulic retenion time at 8 hrs were the highest. The specific hydrogen production rates were Bean sludge 334 ml-H2/g VSS/hr, Limin sludge 524 ml-H2/g VSS/hr and Nato sludge 536 ml-H2/g VSS/hr.

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Mudunge, Reginald. "Comparison of an anaerobic baffled reactor and a completely mixed reactor : start-up and organic loading tests." Thesis, 2000. http://hdl.handle.net/10413/5584.

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The aim of the investigation was to compare the performance of an anaerobic baffled reactor (ABR) with a completely mixed anaerobic reactor (CMAR). The ABR was operated with a hydraulic retention time (HRT) of 20 h while the CMAR was operated at 20 d. A control experiment was conducted with a CMAR operated at a constant hydraulic retention time and substrate feed concentration. During the first phase, the start-up performance of the ABR and CMAR were compared. In the second phase of the study the steady state COD removals were compared. The laboratory completely mixed anaerobic reactor was a 20L glass vessel with a stirrer coming in through the neck. A second type of reactor, anaerobic baffled reactor (ABR) was also operated. The ABR was a rectangular perspex box with internal vertical baffles alternately hanging and standing. The baffles divide the reactor into eight compartments with a total working volume of 7.5 L. Each baffle is angled at about 45Q to distribute the flow towards the centre of the upcomer. The reactors were seeded with raw sewage and allowed to stand for 3 days after which a continous feed of sucrose and basal salts was commenced. The initial HRT for the ABR and the CMAR were 60 h and 30 days respectively. When the reactors reached steady state (pH, gas production, gas composition and alkalinity), the HRT was reduced in a stepwise fashion (ABR 60 h to 35 h to 20 h and CMAR 35 d to 30 d to 20 d). At the final HRT the COD removals were similar (67 %). The ABR took 120 d to attain final steady state while the CMAR took 200 d. The organic loading tests were undertaken with a stepwise increase (doubling) in the influent substrate concentration. The feeding commenced at an organic loading rate (OLR) of 4.8 kg/m(3).d for the ABR. The flow rate (HRT) into both reactors and other parameters were kept constant (HRT of 20 h and 20 d for ABR and CMAR respectively). The substrate concentration was increased from 4 gCOD/L (4.8 kg/m(3).d) to 64 gCOD/L (76.8 kg/m(3).d) for the ABR. For the CMAR it was increased from 4 gCOD/L (0.25 kg/m(3).d) to 32 gCOD/L (2 kg/m(3).d). The method used was to increase the organic loading rate until the reactors failed. Since the two reactors had different operating HRTs, the tests began when both had the same COD removal rate of about 60 % COD reduction. The same parameters as in the start-up period were monitored for both reactors. The CMAR had a COD removal efficiency ca. 70 %, which did not fluctuate when OLR was increased. The ABR reached a maximum COD removal of 80 %. An increase in the OLR led to an initial decrease in the COD removal until the biomass recovered and the high COD (80 %) removal rates resumed. The ABR reached a maximum OLR of 76.8 kg/m(3).d whilst the CMAR reached a maximum OLR of 2.0 kg/m(3).d. The investigations showed that the ABR could be operated at higher organic loads than the CMAR and give the same organic removal rate. This verified the importance of increasing the SRT/HRT ratio in anaerobic reactors. The CMAR, however, proved to be stable to changes in the influent feed strength, as there was no immediate noticeable changes in the gas production.
Thesis (M.Sc.Eng.)-University of Natal, Durban, 2000.

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Jiang, Li-Fan, and 蔣禮帆. "The Effects of Reaction Time of Vertical Jump and Lower ExtremityPower on the Performance of Swimming Start." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/51545744412604249740.

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碩士
國立體育學院
教練研究所
91
The purpose of the study was to investigate the reaction time of vertical jump and lower extremity power on the performance of swimming starts. The subjects were twenty-one elite competitive swimmers from Taipei Physical Education College. They were divided into two groups, one group performed flat start, the other performed pike start. A digital camera (Sharp/VL-WD450U) and the Kistler force plate were used to collect images of starts and kinetic variables. Images were analyzed in kinematical variables by the software of Ariel Performance Analysis System (APAS). The SPSS software was adopted to calculate the values of the parameters and independent T-test was used to test the difference between the two starts. The method of Pearson’s correlation was used to test the correlation among parameters of the two starts. The significance level was set at 0.05. After treating the data, the results were obtained. The correlation between the reaction time of vertical jump and reaction time of start was significant (p＜0.05). Significant differences were found between the flat start and pike start in the aspects of peak force, impulse, take-off angle, flight distance(p＜0.05). With the way of flat start, the correlations between kinematical variables and kinetic variables was significant except the relationship between rate of force developed and flight distance as well as that between impulse and initial velocity (p＜0.05). With the pike start, the correlations between kinematical variables and kinetic variables were significant（p＜0.05）except the relationship between average power and take-off velocity as well as that between impulse and take-off velocity. As the effect of power of lower extremity on performance, the lower extremity has greater influence on the kinematical variables and kinetic variables of pike start than flat start.

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47

Feng-YuWu and 吳?宇. "Analyses of the Start-up and Steady Reactions of Methanol Reforming Employing an Air-blast Atomizer." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/30514842681952147908.

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碩士
國立成功大學
航空太空工程學系專班
98
The start-up process, methanol conversion and hydrogen production of the auto-thermal reformer (ATR) have been investigated by numerical simulation in the present study. The employed catalyst is Pt/CeO2-ZrO2. For the start-up process of the investigated ATR, the sparking plug is employed to ignite methanol, providing thermal energy and heating up the catalyst. As the catalyst meets the self-sustained condition, the sparking plug is shut down and the reforming reaction proceeds to the stable condition. The simulation results show that the start-up process of ATR takes less than 2 minutes when the methanol atomizer is employed. Under steady operation, increasing the air-inlet temperature has no effect on the conversion rate while it slightly reduces the hydrogen production. The results of simulation indicate that employing the atomizer leads to shorter start-up time than that of the case by gaseous feeding. The feasibility of heating the catalyst by spark ignition has been observed. The technique of spark ignition has significant benefit on the reduction of energy loss for the start-up process of the methanol reformer.

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48

Pinto, José Filipe Carvalho. "Effects of various compounds on the biological performance of the THIOPAQ® reactor and start-up and stabilization of an ANAMMOX® lab-scale reactor." Master's thesis, 2018. http://hdl.handle.net/1822/72528.

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Dissertação de mestrado em Tecnologia e Ciência Alimentar
Sulphur is the tenth most abundant element in the universe. It is a key element to sustain life on Earth being present in all living tissues as it is a constituent of many biologically active compounds and therefore involved in many biochemical reactions. It is also a critical plant nutrient in agriculture, an ingredient in sustainable urban development and an essential input in efforts to slow the loss of productive farm land due to soil degradation and its depletion. However, the biological and geological sulphur cycles have been significantly perturbed by human activities mainly because of sulphur dioxide (SO2) emissions to the atmosphere which contributes to several environment problems. Most of these anthropogenic sources are attributed to the combustion of fossil fuels. Acid rain, health problems, odor irritation and corrosion of steel are well known adverse effects of sulphur pollution. Considering these negative effects, there is a growing need of set up emission control strategies to protect the public health and the environment. THIOPAQ® is a gas desulphurisation technology for the removal of hydroxide sulphide (H2S) from gas streams. The H2S is absorbed in a scrubber under alkaline conditions and then goes into a bioreactor where, once in contact with sulphur-oxidizing microorganisms it is converted in elemental sulphur (S0) under aerobic conditions, which later is separated by a settler. The elemental sulphur, produced by the THIOPAQ® can be then used as a high-quality fertiliser. The goal of this project is to study the effects of various organic compounds on the bioreactor performance, such as microorganism activity, foam formation and properties of the produced sulphur. The experiments are conducted in the Water Application Centre (WAC) in Leeuwarden, the Netherlands, with two different experimental setups: a lab-scale THIOPAQ® bioreactor and a Biological Oxygen Monitoring setup for biomass activity monitoring and acute toxicity tests. This work also covers the maintenance of an ANAMMOX® reactor, an innovative technology that aims to remove nitrogen from wastewater in order to reduce its impact on the environment. This project also took place in the WAC installations.

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49

Han-LinLin and 林翰璘. "Advances in understanding start-up and implementation of anammox reactor: a case study by scaling up a granular sludge reactor treating tertiary effluent of coking wastewater." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/adb8yz.

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博士
國立成功大學
環境工程學系
104
This study is mainly conducted to develop a nitration-anammox reactor system that can be use to remove nitrogen from industrial wastewater with a low hydraulic retention time (HRT) below 0.2 day. In this study, continuous-flow experiments using lab-scale nitritation-anammox reactor systems, including a two-stage aerobic and anoxic fixed-bed reactor system (30 L×2), an one-stage hybrid biofilm-carrier reactor system (10 L) and a granular- sludge reactor (20 L) were first undertaken to explore their capability for removing nitrogen from synthetic wastewater and actual industrial wastewaters. Also, the performance of two-stage and one-stage reactor system, as well as of different type of reactors was discussed. After the afore-said lab-scale experiments had been completed, a pilot-scale two-stage reactor system was designed and used to evaluate the performance treating tertiary effluent of coking wastewater. Meanwhile, the methano- genic granules were selected as the seed to start up the anammox reactor in order to directly obtain anammox granules. The results of lab-scale experiments indicated that a volumetric conversion rate (0.2–0.3 kg N m−3 d−1) of one-stage system was apparently lower than that of two- reactor system (nitritation: 0.6–1.4 kg N m−3 d−1; anammox: 0.4–0.8 kg N m−3 d−1). This is mainly because the volumetric conversion rate was governed by a complex bio-kinetics of two-layer structure biofilm in the one-stage reactor system. In reactor choice, although the volumetric loading rate of the fixed-bed reactor could increase from 0.1 kg N m−3 d−1 to 0.4–0.5 kg N m−3 d−1 within first 3 months [extending solid retention time (SRT) by using non-woven carriers with high specific surface], after that the volumetric loading rate of the fixed-bed reactor could not improve anymore and only kept at 0.5–0.6 kg N m−3 d−1. A possible explanation is that the fixed carriers resulted in a stagnating effect, leading a weak shear stress to detach biofilm (higher diffusion resistance occurs in a thicker biofilm and limits the increase of the volumetric loading rate); In contrast, although the formation of granular sludge in the granular-sludge reactor generally required to spend at least one year increasing the volumetric conversion rate above 1.0 kg N m−3 d−1, with favorable operating conditions (bulk NO2−-N concentration below 50 mg L−1, HRT 〈 0.2 d), the volumetric conversion rate of granular-sludge reactor could be gradually increased to above 2.0 kg N m−3 d−1. It is indicated that granular sludge reactor possesses not only a sufficient SRT, but also a better mixing rather than the fixed-bed reactor. Thus, the granular-sludge reactor can be a promising alternative to be employed in industrial wastewaters (high nitrogen loading rate, low HRT and insufficiently available footprint). In pilot evaluation, a two-stage process of nitritation (3-m3) and anammox (1-m3) was undertaken to explore its capability for removing nitrogen from tertiary effluent of coking wastewater. Moreover, methanogenic granules were selected as the seed to start up the anammox reactor in order to directly obtain anammox granules (to avoid a long period for granulation and start-up). Results showed that the anammox reactor was successfully started up with volumetric loading rate of 1.0 kg N m−3 d−1 and nitrogen removal efficiency of 89%, respectively. According to the analysis of size diameter and distribution, average granule size of 0.77–0.98 mm at day 218 grew to 1.83–1.9 mm at day 513. The nuclei of a large proportion of anammox granules retained part of the original seed biomass. Anammox biofilm attached to the surfaces of methanogenic granule and turned red, meanwhile new anammox granules were formed (smaller, not smooth and rounded). The findings of this study are expected to develop strategies of shorter start-up and more stable operation of anammox reactor.

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Chen, Yi-Chian, and 陳毅謙. "Simultaneous partial Nitrification, Anammox and Denitrification (SNAD) Process in Sequencing Batch Reactor: Fast Start-up and Effects of Zinc." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/61402804201767393492.

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碩士
國立交通大學
環境工程系所
102
Anammox has been regarded as the most cost effective and efficient nitrogen removal process. However, its real world applications are limited due to long start-up time. Moreover, heavy metals such as zinc are common in several wastewater streams and can affect the anammox process. Therefore, in this study novel carriers were used to retain biomass for fast start-up of the simultaneous partial nitrification, anammox and denitrification (SNAD) process in a sequencing batch reactor (SBR) and the short- and long-term effects of the zinc on the SNAD process were investigated. The SNAD process was started up in 51 days and within one month the biomass attached to the carriers in the form of biofilm. Nitrogen and COD removal efficiencies were over 90% when the NLR and OLR increased to 360 and 180 g/m3-d, respectively. The short-term effect of zinc on the anammox activity was evaluated using batch tests. The IC50 of zinc at 24 h exposure time was 6.9 mg/L. The long-term effect of zinc on the SNAD process was examined in SBR. The NH4+-N, TN and COD removal efficiencies at 100 mg/L zinc concentration were 98, 97, and 86%, respectively. These results suggested that carrier used are efficent in biomass retention inside the reactor and it is feasible to treat zinc containing nitrogen rich wastewater by SNAD process.

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