Academic literature on the topic 'Escape Reaction'
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Journal articles on the topic "Escape Reaction"
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Zhou, Yanjun. "Applications of Kramers Escape Rate Theory With Power-Law Distributions." Revista Processos Químicos 9, no. 18 (July 1, 2015): 393–97. http://dx.doi.org/10.19142/rpq.v9i18.339.
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Kramers escape rate theory is the most important one of modern reaction rate theories. However, one key assumption of the theory that thermodynamic equilibrium must prevail throughout the entire system studied is farfetched for open complex systems. Thereby, Kramers escape rates are generalized to describe rates of reactions in nonequilibrium systems with power-law distributions. Kramers escape rates in the very low damping systems, in overdamped systems and in the low-to-intermediate damping (LID) systems are investigated and the corresponding escape rates are obtained respectively on the basis of nonextensive statistics. When apply to biological, physical and chemical systems in each damping systems, these generalized escape rates with power-law distribution show a better agreement with experimental rates as compared with the traditional Kramers escape rates. It is expected that the generalized result can lead to an insight into the research on reaction rate theory for nonequilibrium complex systems with power-law distributions.
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Kawai, Tadahiko, Shumei Murakami, Takashi Maeda, Mitsunobu Kishino, and Kayoko Amino. "Mucus escape reaction that involves the mandible." Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 83, no. 3 (March 1997): 408–15. http://dx.doi.org/10.1016/s1079-2104(97)90250-x.
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Davis, April D., Tina M. Weatherby, and Petra H. Lenz. "Speedy Plankton: Myelinated Axons In Calanoid Copepods (Crustacea)." Microscopy and Microanalysis 5, S2 (August 1999): 1308–9. http://dx.doi.org/10.1017/s1431927600019863.
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Copepods are an abundant and diverse group of crustaceans. One order of free living copepods, the calanoids, are usually < 3 mm in length, planktonic, and possess very rapid escape responses. These animals dominate planktonic communities and their escape reactions contribute to their success. Although all calanoids respond to hydrodynamic disturbances with an escape jump, minimum reaction times vary among species, ranging from 1.5 to 6 msec. To help us understand the physiological basis underlying the phenomenally short reaction times we initiated a comparative study of the internal structures by using transmission electron microscopy (TEM).Traditional chemical fixation was adequate for several species of copepods, and sensory structures were clearly shown. In these calanoids, minimum reaction times ranged from 3 msec to 6 msec and can be partially explained by giant axons, the most common way invertebrates increase the rate of conduction of nerve impulses. However, the internal structures of two copepod species, Euchaetarimana and Undinula vulgaris, were distorted (Fig. 1).
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Ye, Chen, and Yu Huan. "Studies on Electron Escape Condition in Semiconductor Nanomaterials via Photodeposition Reaction." Materials 15, no. 6 (March 13, 2022): 2116. http://dx.doi.org/10.3390/ma15062116.
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In semiconductor material-driven photocatalysis systems, the generation and migration of charge carriers are core research contents. Among these, the separation of electron-hole pairs and the transfer of electrons to a material’s surface played a crucial role. In this work, photodeposition, a photocatalysis reaction, was used as a “tool” to point out the electron escaping sites on a material’s surface. This “tool” could be used to visually indicate the active particles in photocatalyst materials. Photoproduced electrons need to be transferred to the surface, and they will only participate in reactions at the surface. By reacting with escaped electrons, metal ions could be reduced to nanoparticles immediately and deposited at electron come-out sites. Based on this, the electron escaping conditions of photocatalyst materials have been investigated and surveyed through the photodeposition of platinum. Our results indicate that, first, in monodispersed nanocrystal materials, platinum nanoparticles deposited randomly on a particle’s surface. This can be attributed to the abundant surface defects, which provide driving forces for electron escaping. Second, platinum nanoparticles were found to be deposited, preferentially, on one side in heterostructured nanocrystals. This is considered to be a combination result of work function difference and existence of heterojunction structure.
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Jakubas, Dariusz, Katarzyna Wojczulanis-Jakubas, Alexis Powers, Troy Frazier, Michael Bottomley, and Michał Kraszpulski. "Differences in a Cage Escape Behaviour between Two Migrating Warblers of Different Stop-Over Strategy." Animals 11, no. 3 (February 28, 2021): 639. http://dx.doi.org/10.3390/ani11030639.
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Cognitive abilities play an important role for migratory birds that are briefly visiting a variety of unfamiliar stop-over habitats. Here, we compared cognitive abilities-linked behaviour (escape from an experimental cage) between two long-distant migrants differing in stop-over ecology, Sedge Warbler (Acrocephalus schoenobaenus; not territorial, searching for locally superabundant food) and Reed Warbler (A. scirpaceus; territorial, foraging on a common prey) during the autumn migration. After two minutes of acclimatization in the cage, we remotely opened the cage door and recorded the bird’s reaction. We measured latency that individuals needed to escape from a cage. Sedge warblers were 1.61 times more likely to escape from the cage than Reed Warblers. Sedge warblers generally escaped earlier after the door was opened and were 1.79 times more likely to escape at any given time than Reed Warblers. We interpret the prevalence of non-escaped individuals as a general feature of migratory birds. In contrast to resident species, they are more likely to enter an unfamiliar environment, but they are less explorative. We attributed inter-species differences in escape latency to species-specific autumn stop-over refuelling strategies in the context of specialist-generalist foraging. Our study provides ecological insight into the cognitive abilities-linked behaviour of wild animals.
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Krasne, FB, and DL Glanzman. "Sensitization of the crayfish lateral giant escape reaction." Journal of Neuroscience 6, no. 4 (April 1, 1986): 1013–20. http://dx.doi.org/10.1523/jneurosci.06-04-01013.1986.
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DYBIEC, BARTŁOMIEJ, EWA GUDOWSKA-NOWAK, and PAWEŁ F. GÓRA. "IMPLICATION OF BARRIER FLUCTUATIONS ON THE RATE OF WEAKLY ADIABATIC ELECTRON TRANSFER." International Journal of Modern Physics C 13, no. 09 (November 2002): 1211–22. http://dx.doi.org/10.1142/s0129183102004078.
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The problem of escape of a Brownian particle in a cusp-shaped metastable potential is of special importance in nonadiabatic and weakly-adiabatic rate theory for electron transfer (ET) reactions. For the weakly-adiabatic reactions, the reaction follows an adiabaticity criterion in the presence of a sharp barrier. In contrast to the nonadiabatic case, the ET kinetics can be, however considerably influenced by the medium dynamics. In this paper, the problem of the escape time over a dichotomously fluctuating cusp barrier is discussed with its relevance to the high temperature ET reactions in condensed media.
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Heitler, W. J., K. Fraser, and E. A. Ferrero. "Escape behaviour in the stomatopod crustacean Squilla mantis, and the evolution of the caridoid escape reaction." Journal of Experimental Biology 203, no. 2 (January 15, 2000): 183–92. http://dx.doi.org/10.1242/jeb.203.2.183.
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The mantis shrimp Squilla mantis shows a graded series of avoidance/escape responses to visual and mechanical (vibration and touch) rostral stimuli. A low-threshold response is mediated by the simultaneous protraction of the thoracic walking legs and abdominal swimmerets and telson, producing a backwards ‘lurch’ or jump that can displace the animal by up to one-third of its body length, but leaves it facing in the same direction. A stronger response starts with similar limb protraction, but is followed by partial abdominal flexion. The maximal response also consists of limb protraction followed by abdominal flexion, but in this case the abdominal flexion is sufficiently vigorous to pull the animal into a tight vertical loop, which leaves it inverted and facing away from the stimulus. The animal then swims forward (away from the stimulus) and rights itself by executing a half-roll. A bilaterally paired, large-diameter, rapidly conducting axon in the dorsal region of the ventral nerve excites swimmeret protractor motoneurons in several ganglia and is likely to be the driver neuron for the limb-protraction response. The same neuron also excites unidentified abdominal trunk motoneurons, but less reliably. The escape response is a key feature of the malacostracan caridoid facies, and we provide the first detailed description of this response in a group that diverged early in malacostracan evolution. We show that the components of the escape response contrast strongly with those of the full caridoid reaction, and we provide physiological and behavioural evidence for the biological plausibility of a limb-before-tail thesis for the evolution of the escape response.
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Kugel, Jennifer F., and James A. Goodrich. "Promoter escape limits the rate of RNA polymerase II transcription and is enhanced by TFIIE, TFIIH, and ATP on negatively supercoiled DNA." Proceedings of the National Academy of Sciences 95, no. 16 (August 4, 1998): 9232–37. http://dx.doi.org/10.1073/pnas.95.16.9232.
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To measure rate constants for discrete steps of single-round transcription (preinitiation complex formation, promoter escape, and transcript elongation), kinetic studies were performed in a well defined human RNA polymerase II transcription system. These experiments revealed that promoter escape limits the rate of transcription from the adenovirus major late promoter (AdMLP) contained on negatively supercoiled DNA. TFIIE and TFIIH were found to significantly increase fractional template usage during a single round of transcription in an ATP-dependent reaction. The observed rate constant for promoter escape, however, was not greatly affected by TFIIE and TFIIH. Our results are explained by a model in which transcription branches into at least two pathways: one that results in functional promoter escape and full-length RNA synthesis, and another in which preinitiation complexes abort during promoter escape and do not produce full-length RNA transcripts. These results with negatively supercoiled templates agree with our earlier conclusion that TFIIE, TFIIH, and ATP direct promoter escape and support a model in which the TFIIH helicases stimulate promoter escape in an ATP-dependent reaction.
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Pathapati, Rama Mohan, Manchi Rajesh Kumar, B. L. Kudagi, and Madhavulu Buchineni. "Change from baseline as an outcome illustrates escape behaviour of rats in hot plate method." International Journal of Basic & Clinical Pharmacology 6, no. 10 (September 23, 2017): 2348. http://dx.doi.org/10.18203/2319-2003.ijbcp20174357.
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Background: The Hot Plate test is a thermal hyperalgesia model to assess the analgesic activity of many compounds. Traditional analysis compares reaction times with controls, reports only analgesic activity without considering escape reflex. Escape reflex to pain sensation also provides an indirect measure of analgesic activity. However, it requires repeated exposure of rats to hot plate. We explored the learning activities and escape behaviour of rats by calculating the change from baseline of reaction times.Methods: Male Wister strain albino rats, weighing between 150-200mg were used for assessment of hot-plate induced hyperalgesia. Author analysed the analgesic activity of aspirin (100mg/Kg) and compared with animals receiving saline. Aspirin and saline were administered 1hr orally before the commencement of the experiment. The reaction time was recorded at every 30 min up to 6hrs.Results: With traditional analysis, we can observe that the onset of action, peak action and duration of analgesic activity of aspirin was at 0.5, 2.0 and 5.0 hours respectively. Peak inhibition of reaction time was seen at 2 hours with a magnitude of 474%. When we applied a statistical procedure, absolute change from baseline statistics, we found that animals treated with aspirin also exhibited escape reflex after fading of drug response and animals treated with saline demonstrated early (0.5hr) escape behaviour from the hot plate and continued throughout the rest of the experiment.Conclusions: Change from baseline as an outcome illustrates escape behaviour of rats in hot plate method and it should be employed along with percentage inhibition during assessment of analgesic activity.
Dissertations / Theses on the topic "Escape Reaction"
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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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Arafiles, Jan Vincent Valenzuela. "Macropinocytosis-Inducing Peptides: Identification, Utility, and Mechanism-of-Action." Kyoto University, 2020. http://hdl.handle.net/2433/259021.
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Pirri, Jennifer K. "The Role of Ion Channels in Coordinating Neural Circuit Activity in Caenorhabditis elegans: A Dissertation." eScholarship@UMMS, 2013. http://escholarship.umassmed.edu/gsbs_diss/662.
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Despite the current understanding that sensorimotor circuits function through the action of transmitters and modulators, we have a limited understanding of how the nervous system directs the flow of information necessary to orchestrate complex behaviors. In this dissertation, I aimed to uncover how the nervous system coordinates these behaviors using the escape response of the soil nematode, Caenorhabditis elegans, as a paradigm. C. elegans exhibits a robust escape behavior in response to touch. The worm typically moves forward in a sinusoidal pattern, which is accompanied by exploratory head movements. During escape, the worm quickly retreats by moving backward from the point of stimulus while suppressing its head movements. It was previously shown that the biogenic amine tyramine played an important role in modulating the suppression of these head movmemetns in response to touch. We identified a novel tyramine-gated chloride channel, LGC-55, whose activation by tyramine coordinates motor programs essential for escape. Furthermore, we found that changing the electrical nature of a synapse within the neural circuit for escape behavior can reverse its behavioral output, indicating that the C. elegans connectome is established independent of the nature of synaptic activity or behavioral output. Finally, we characterized a unique mutant, zf35 , which is hyperactive in reversal behavior. This mutant was identified as a gain of function allele of the C. elegans P/Q/N-type voltage-gated calcium channel, UNC-2. Taken together, this work defines tyramine as a genuine neurotransmitter and completes the neural circuit that controls the initial phases of the C. elegans escape response. Additionally, this research further advances the understanding of how the interactions between transmitters and ion channels can precisely regulate neural circuit activity in the execution of a complex behavior.
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Donnelly, Jamie L. "Tyraminergic G Protein-Coupled Receptors Modulate Locomotion and Navigational Behavior In C. Elegans: A Dissertation." eScholarship@UMMS, 2011. https://escholarship.umassmed.edu/gsbs_diss/575.
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An animal’s ability to navigate through its natural environment is critical to its survival. Navigation can be slow and methodical such as an annual migration, or purely reactive such as an escape response. How sensory input is translated into a fast behavioral output to execute goal oriented locomotion remains elusive. In this dissertation, I aimed to investigate escape response behavior in the nematode C. elegans. It has been shown that the biogenic amine tyramine is essential for the escape response. A tyramine-gated chloride channel, LGC-55, has been revealed to modulate suppression of head oscillations and reversal behavior in response to touch. Here, I discovered key modulators of the tyraminergic signaling pathway through forward and reverse genetic screens using exogenous tyramine drug plates. ser-2, a tyramine activated G protein-coupled receptor mutant, was partially resistant to the paralytic effects of exogenous tyramine on body movements, indicating a role in locomotion behavior. Further analysis revealed that ser-2 is asymmetrically expressed in the VD GABAergic motor neurons, and that SER-2 inhibits neurotransmitter release along the ventral nerve cord. Although overall locomotion was normal in ser-2 mutants, they failed to execute omega turns by fully contracting the ventral musculature. Omega turns allow the animal to reverse and completely change directions away from a predator during the escape response. Furthermore, my studies developed an assay to investigate instantaneous velocity changes during the escape response using machine based vision. We sought to determine how an animal accelerates in response to a mechanical stimulus, and subsequently decelerates to a basal locomotion rate. Mutant analysis using this assay revealed roles for both dopamine and tyramine signaling. During my doctoral work, I have further established the importance for tyramine in the nematode, as I have demonstrated two additional roles for tyramine in modulating escape response behavior in C. elegans.
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Ibrahim, Karim Yaqub. "Escape transitório da viremia plasmática de HIV-1 e falência virológica em indivíduos sob terapêutica anti-retroviral: incidência e fatores associados." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/5/5134/tde-04112010-171645/.
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INTRODUÇÃO: Pacientes em terapia anti-retroviral podem apresentar escapes transitórios de viremia plasmática (blip), porém os preditores desse evento e seu impacto sobre a incidência de falência virológica são ainda controversos na literatura. Neste estudo de coorte estimou-se a incidência de blip e de falência virológica e investigaram-se possíveis preditores de tais desfechos. Blip foi definido como carga viral superior a 50 cópias/mL com subseqüente supressão da viremia plasmática e falência virológica como duas medidas consecutivas de carga viral plasmática superiores a 50 cópias/mL. Adicionalmente, pesquisou-se, por ocasião desses eventos, a presença de mutações genotípicas de HIV capazes de conferir resistência aos anti-retrovirais e as concentrações plasmáticas de inibidores não nucleosídicos da transcriptase reversa e inibidores da protease, comparando-as com o relato dos participantes sobre adesão à medicação. MÉTODOS: 350 participantes infectados pelo HIV (250 homens e 100 mulheres) foram selecionados no Serviço de Extensão ao Atendimento de Pacientes com HIV/Aids Casa da Aids do Hospital das Clínicas da FMUSP, São Paulo, Brasil. Na admissão ao estudo e trimestralmente, ao longo de 78 semanas, foram coletadas informações sobre dados sóciodemográficos, forma presumida de aquisição do vírus, uso de e adesão a medicações anti-retrovirais, ocorrência de outras comorbidades, bem como uso de álcool e de drogas ilícitas. Investigaram-se fatores potencialmente associados à incidência dos desfechos de interesse, tais como ocorrência de outras doenças, exposição a imunizações e falha na adesão a práticas de sexo mais seguro. Amostras de sangue periférico foram coletadas a cada visita para determinação de carga viral plasmática por RT-PCR ultrassensível, e contagem de linfócitos T CD4+ por citometria de fluxo. Nos indivíduos que apresentaram os desfechos de interesse do estudo, procedeu-se ao seqüenciamento dos genes da transcriptase reversa e da protease de HIV e à dosagem plasmática dos anti-retrovirais por método de Cromatografia Líquida de Alta Performance. As incidências de blip e falência virológica foram estimadas e os fatores associados a ambos investigados em modelo de regressão logística múltipla. RESULTADOS: As incidências de blip e falência virológica foram 9,4 e 4,2/100 pessoas-ano, respectivamente. Três indivíduos apresentaram falência virológica precedidos por blip. À análise multivariada, a não adesão às praticas de sexo mais seguro no mês precedente se mostrou independentemente associada à ocorrência de blip (OR 24,64, IC 95% 4,40 137,88, p<0,001) e de falência virológica (OR 24,69, IC 95% 4,20 145,18, p<0,001). Adicionalmente, observou-se que a exposição prévia a maior número de esquemas anti-retrovirais foi preditora dos eventos blip (OR 1,82, IC 95% 1,41 2,36, p<0,001) e falência virológica (OR 1,67, IC 95% 1,19 2,35, p=0,003). A ocorrência de blip não se associou ao desenvolvimento posterior de falência virológica. Um maior número de mutações conferidoras de resistência medicamentosa foi identificado no momento de falência virológica, quando comparado ao momento de blip, com predomínio de mutações no gene da transcriptase reversa, refletindo o maior uso desses fármacos. Das 122 concentrações plasmáticas de anti-retrovirais analisadas em 120 amostras, 84 estavam em níveis terapêuticos adequados. Porém, tais resultados apresentaram apenas 69% de concordância com a adesão auto-referida à medicação. Este estudo mostra que apresentar blip em uma medida isolada pode ser um evento benigno; por outro lado, falência virológica pode ser conseqüente a acúmulo de mutações conferidoras de resistência a pelo menos um dos anti-retrovirais em uso, podendo comprometer a eficácia do esquema terapêutico utilizado. Ambos os desfechos mostraram-se mais incidentes na população multiexperimentada à terapêutica, que, portanto, merece atenção particular. Uma importante contribuição deste estudo foi a avaliação da dosagem plasmática dos antiretrovirais, método simples e de baixo custo, que, implantado na rotina laboratorial, pode contribuir para o monitoramento da adesão aos antiretrovirais e reduzir a demanda por testes genotípicosBACKGROUND: HIV-1-infected patients under antiretroviral therapy may present intermittent viremia (blip); however, predictors of this outcome and its influence on the incidence of virologic failure remain controversial in the literature. The aim of this study is to estimate the incidence of blip and virologic failure in a cohort of patients under stable antiretroviral therapy and to investigate their associated factors. Blip was defined as a plasma HIVRNA load above 50 copies/mL followed by a subsequent value below 50 copies/mL. Virologic failure was defined as two consecutives measures of viral load above 50 copies/mL. Moreover, at time of occurrence of these outcomes, HIV genotyping assays were performed in search of drug resistance-associated mutations, and plasma concentrations of nonnucleoside reverse transcriptase and protease inhibitors assessed and compared with self-reported adhrence to therapy. METHODS: 350 subjects (250 male and 100 female) were enrolled at the HIV Clinic, School of Medicine, University of São Paulo, Brazil and followed for 78 weeks. At baseline and in 3-month interval follow-up visits we collected sociodemographic data and information on presumed mode of HIV acquisition, use of and adherence to antiretrovirals, comorbidities and use of alcohol and illicit drugs. Additionally, patients were questioned about potential predictors of the outcomes, including occurrence of other diseases, immunizations and risky sexual behavior. Blood samples were drawn for assessment of HIV plasma viral loads, using ultrasensitive RT-PCR, and T CD4+ cell counts by flow cytometry. Individuals who presented blip and/or virologic failure were submitted to HIV genotyping assays and assessment of antiretroviral plasma concentrations by high-performance liquid chromatography. Incidences of blip and virological failure were estimated and associated factors investigated, using a multiple logistic regression model. RESULTS: The incidence of blip and of virologic failure were 9.4/100 and 4.2/100 person-years, respectively. Three individuals presented virologic failure after blip episodes. On multivariate analysis, non-adherence to safer sex measures in the previous month was shown independently associated with the occurrence of blip (OR 24.64, 95%CI 4.40 137.88, p<0.001) and virologic failure (OR 24.69, 95%CI 4.20 145.18, p<0.001). In addition, history of multiple exposures to antiretroviral regimens was also a predictor of blip (OR 1.82, 95%CI 1.41 2.36, p<0.001) and virologic failure (OR 1.67, 95%CI 1.19 2.35, p<0.001). Blips were not predictive of virologic failure. A larger number of HIV mutations were identified at time of virologic failure, as compared to blip episodes, with mutations detected predominantly in the reverse transcriptase (RT) gene, probably due to larger exposure to RT inhibitors. Eighty-four out of 122 assessments of antiretroviral plasma concentrations analyzed in 120 samples resulted in the therapeutic range. However, these results were concordant with self-reported adherence to therapy in 69% of cases only. This study shows that a single blip episode may be considered benign, whereas virologic failure could result from accumulation of HIV drug resistance-associated mutations that may impair the efficacy of therapy. Both study outcomes occurred more frequently among patients with larger exposure to antiretrovirals, and therefore they should be monitored in this regard. An important contribution of this study concerns the assessment of antiretroviral plasma concentrations, a simple and low cost laboratory tool. Incorporated routinely in patient follow-up, it would help monitoring adherence to therapy and reduce the need for HIV genotyping assays
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Araujo, Thiago Lopes da Silva. "Desempenho de reator anaeróbio híbrido (leito fixo e manta de lodo) tratando esgoto sanitário em escala piloto." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-02102014-095241/.
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O presente trabalho estudou o aumento de capacidade de tratamento de um reator UASB (Upflow Anaerobic Sludge Blanket) por meio da adição de material suporte para adesão celular (Biobob®), avaliando-se as eficiências de remoção de matéria orgânica (expressa como DQO demanda química de oxigênio) e sólidos em suspensão (expressos como SST sólidos em suspensão totais). O reator híbrido, no qual a biomassa está presente em suspensão e imobilizada no material suporte, foi submetido a baixos tempos de detenção hidráulica (TDH) e altas velocidades ascensionais (vs). A operação do reator anaeróbio, de volume útil igual a 12,5 m³, foi conduzida em duas etapas. Na primeira o sistema foi operado como um reator de manta de lodo e escoamento ascendente (UASB), com TDH de 8,8 h e velocidade ascensional de 0,63 m.h-1. Na segunda etapa, introduziu-se 5,0 m³ de material suporte Biobob® no leito reacional do reator, transformando-o em reator anaeróbio híbrido (HAnR). Nessa condição, variou-se a vazão de alimentação, tendo o TDH variado entre 7,4 h (vs de 0,66 m.h-1) a 3,9 h (vs de 1,25 m.h-1). Para ambas as etapas o sistema foi alimentado com esgoto sanitário à temperatura ambiente, após tratamento preliminar (gradeamento e caixa de areia). Para condições de operação similares, o reator anaeróbio híbrido (HAnR) apresentou melhor desempenho na remoção de DQO e SST que o reator UASB, acrescendo em até 18% e 30% a eficiência de remoção, respectivamente. Para a velocidade ascensional de 1,25±0,02 m.h-1 e TDH de 3,9±0,1 h, o HAnR apresentou concentrações médias no efluente tratado de 205±46 mg DQOt.L-1 e 73±30 mg SST.L-1 e eficiências de remoção de 55±9% DQOt e 63±14% SST.The increase of the treatability capacity of a UASB (Upflow Anaerobic Sludge Blanket) reactor by introducing an innovative packing material (Biobob®) in its reaction zone was evaluated. The hybrid anaerobic reactor (HAnR) containing suspended and immobilized biomass was evaluated regarding its efficiency of removing organic matter (expressed as COD chemical oxygen demand) and suspended solids (expressed as TSS total suspended solids) under lower hydraulic detention time (HDT) and higher upflow velocities (v s). The anaerobic reactor operation, with 12.5 m³ of working volume, was conducted in two phases. In the first phase, the system was operated as a conventional UASB reactor with HRT of 8.8 h and vs of 0.63 m.h -1 . In the second phase, 5.0 m³ of packing material Biobob® was introduced inside the reaction bed, changing the reactor configuration from suspended growth to hybrid growth. In this condition, the hybrid anaerobic reactor (HAnR) was subjected to decreasing flowrates with HDT ranging from 7.4 h (vs of 0.66 m.h-1) to 3.9 h (vs of 1.25 m.h-1). For both phases, the feed was domestic wastewater (after screens and grit chambers) at ambient temperature. Under similar operation conditions, the HAnR performed better than the UASB reactor increasing at 18% and 30% the COD and TSS removal efficiencies, respectively. For vs of 1.25±0.02 m.h-1 and HDT of 3.9±1.0 h, the HAnR produced a very high quality effluent, with average COD and TSS concentration of 205±46 mg DQOt.L-1 and 73±30 mg SST.L-1 and removal efficiencies of 55±9% and 63±14% for CODt and SST, respectively.
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Gaudencio, Bruno Orlando. "Reator anaeróbio híbrido (leito fixo e manta de lodo) em escala plena tratando esgoto sanitário: avaliação da nova configuração." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-29032017-114253/.
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O presente trabalho teve como objetivo avaliar a viabilidade da aplicação de um reator anaeróbio híbrido (RAnH) em escala plena para tratamento de esgoto sanitário, contendo Biobob ® como meio suporte para imobilização celular. O reator possui volume útil igual a 2.495 m3 e foi resultado de uma adaptação de um reator UASB por meio da introdução de 1.000 m3 de material suporte Biobob® em parte do volume reacional do reator, transformando-o em um reator anaeróbio híbrido com leito fixo e manta de lodo. O reator foi monitorado por 480 dias consecutivos, sendo avaliado seu desempenho frente ao aumento gradativo da vazão média e às vazões decorrentes de horários de pico e períodos com elevada pluviosidade. O reator apresentou bom desempenho durante todo o período operacional, mantendo a qualidade do efluente tratado (DQO efluente média de 178 ± 30mg.L-1 e SST de 54 ± 25 mg.L-1) mesmo quando submetido à elevadas cargas hidráulicas proporcionadas por períodos de alta pluviosidade, mostrando-se como uma excelente alternativa para aumento da capacidade de tratamento de reatores UASB sem a necessidade de ampliações físicas no reator. Para um TDH médio de 5,8 h, que corresponde a um período em que houve vários picos de vazão, o reator manteve-se estável durante todo o período, com valores no efluente de DQO e SST de 169 ± 24 mg.L-1 e 47 ± 17 mg.L-1, respectivamente. Aproximadamente 70% do total da biomassa presente no reator encontra-se em suspensão no leito de lodo e 30% encontra-se aderida aos meios suportes, sendo ambas as frações fundamentais para o bom desempenho e estabilidade do tratamento. O rendimento da produção de biomassa observada (Yobs) foi de 0,182 g SSV.g-1 DQOremovida. Considerando-se a carga orgânica removida por meio da DQO bruta afluente e da DQO filtrada efluente, o Y\'obs foi de 0,143 g SSV. g-1 DQOremovida. A produção de lodo (considerando somente o descarte de sólidos pela via convencional ) foi de 0,073 g ST.g-1 DQO aplicada. Ambas as frações de biomassa (suspensa e aderida) apresentaram potencial metanogênico similar para condições com carga orgânica aplicada de 0,57 g DQO. g-1 SVT. A produção de energia elétrica estimada com o reaproveitamento do biogás gerado no RAnH, para a vazão média do período de 7.170 m3.d-1, foi de 31.798 kW.h.mês-1, o equivalente a 10 % do consumo energético mensal atual da ETE. O aproveitamento dessa energia acarretaria em uma economia mensal de R$ 17.170,73.This study aimed to assess the feasibility of implementing a hybrid anaerobic reactor (HAnR) at full scale for treating wastewater containing Biobob® as a packing material for cell immobilization. The reactor volume is 2,495 m3 and was the result of an adaptation of a UASB reactor by introducing 1,000 m3 of packing material Biobob® in the reaction volume of the reactor, turning it into a hybrid anaerobic reactor with fixed bed and sludge blanket. The reactor was monitored for 480 consecutive days and evaluated their performance with the gradual increase of the average flow and the flow resulting from peak hours and periods of high rainfall. The reactor showed good performance throughout the operational period, maintaining the quality of treated efluente (COD effluent of 178 ± 30 mg. L-1 and TSS 54 ± 25 mg. L-1) even when subjected to high hydraulic loads provided by rainy periods, showing up as an excellent alternative to increase the UASB treatment capacity without the need for expansion physical the reactor. For an average HRT of 5.8 h, which corresponds to a period in which there were several peaks flow, the reactor remained stable throughout the period, with values in the effluent COD and TSS of 169 ± 24 mg.L-1 and 47 ± 17 mg.L-1, respectively. Approximately 70% of the total biomass present in the reactor was in suspension in the sludge bed and 30% adhered to the support material, and both fractions fundamental to the performance and stability of the treatment. The observed yield of biomass production (Yobs) was 0.182 g CODr.VSS.g-1. Considering the organic load removed by the total COD of influent and effluent COD filtered, the Y\'obs was 0.143 g CODr.VSS.g-1. The sludge production (considering only the disposal of solid by conventional means) was 0.073 g COD.TS.g-1 .Both biomass fractions (suspended and attached) have similar potential to methanogenic conditions with organic load of 0.57 g COD.g-1 SVT. The production of electricity estimated to reuse biogas generated in HAnR, for the average flow of the period 7,170 m3.d-1, was 31,798 kW.h.mês-1, equivalent to 10% of the current monthly energy consumption in the sewage treatment plant. The use of this energy would result in a monthly savings of R$ 17,170.73.
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Kawamura, Kazuyuki. "Myelin-reactive type B T cells and T cells specific for low-affinity MHC-binding myelin peptides escape tolerance in HLA-DR transgenic mice." Kyoto University, 2009. http://hdl.handle.net/2433/124346.
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Orozco, López Yasna. "Estudio del Efecto del tipo y concentración de espumante en la selectividad del proceso de flotación a escala laboratorio." Tesis, Universidad de Chile, 2012. http://www.repositorio.uchile.cl/handle/2250/111986.
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Ingeniera Civil QuímicaLa flotación de minerales es una técnica de separación selectiva de partículas en base a su hidrofobicidad. En ella se utiliza una serie de reactivos, entre los que se encuentran los espumantes, cuya función principal es la de contribuir a la formación de burbujas de tamaño pequeño y una fase de espuma estable. En este trabajo se estudia el efecto que tienen los espumantes sobre la relación entre recuperación de agua y recuperación por arrastre de partículas hidrofílicas en una celda de flotación a escala laboratorio. Para estudiar este efecto se realizaron pruebas con espumantes de distinta estructura molecular (alcoholes y polietilenglicoles), primero en ausencia de partículas, para caracterizar el sistema, y posteriormente en presencia de partículas hidrofílicas de cuarzo. Los resultados muestran diferencias de comportamiento entre alcoholes y polietilenglicoles. Para la recuperación de agua, los polietilenglicoles estudiados (PEG400, PEG300 y PEG200) llevan más agua al concentrado que los alcoholes. En el caso de la recuperación por arrastre, son los alcoholes (octanol, heptanol, MIBC y hexanol) los que arrastran más partículas de sólido al concentrado. Los factores de arrastre (ENT) muestran menor valor para polietilenglicoles que para alcoholes, es decir, a igual recuperación de agua, estos últimos arrastran mayor cantidad de partículas, lo que se podría traducir en un efecto diferenciado sobre la selectividad del proceso de flotación. Esto puede deberse a que alcoholes y polietilenglicoles generan distintas estructuras de espuma, las que a su vez afectan tanto recuperación de agua como recuperación por arrastre. Se observa que tanto para alcoholes como para polietilenglicoles el factor ENT aumenta con el peso molecular de los espumantes. Para corroborar si existe un efecto sobre la selectividad del proceso de flotación, se realizaron pruebas de flotación con polietilenglicol (PEG300) y octanol con un mineral preparado de cuarzo más calcopirita, obteniéndose una mayor ley acumulada de cobre en el caso de PEG300, lo cual es consistente con la diferencia observada en factores de arrastre. Se observó también una gran diferencia en las constantes cinéticas de flotación (0,414 [min-1] para PEG300 y 0,184 [min-1] para octanol) que podría estar relacionada con un aumento en el espesor de película de líquido asociado a la superficie de burbuja.
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Allendes, Arcos Hans Mauro. "Diseño y estudio de un reactor a escala banco para la biooxidación de azufre elemental." Tesis, Universidad de Chile, 2014. http://repositorio.uchile.cl/handle/2250/116796.
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Ingeniero Civil QuímicoIngeniero Civil en Biotecnología
El presente trabajo reporta el estudio realizado en un reactor a escala banco para la oxidación biológica de perlas de azufre elemental, en el cual se genera ácido sulfúrico que será utilizado más adelante en la producción sustentable de fosfatos desde una roca fosfórica. Para lo anterior, se utilizó como punto de partida el cultivo de la arquea Sulfolobus metallicus en matraces agitados a 67°C, crecidas sobre perlas de azufre elemental. A partir de esta manipulación, se implementaron fases de escalamiento que contemplaron un reactor agitado tipo batch y su símil en modo continuo, ambos con condiciones de operación derivadas directamente de los matraces. En modo batch se monitorearon periódicamente el pH, acidez del medio, concentración de sulfato en solución y conteo de células planctónicas. Los resultados obtenidos indicaron un buen escalamiento desde los matraces, con valores similares a trabajos previos que utilizaron aquel sistema de reacción. Además, a partir de lo registrado en el conteo celular, se obtuvo una tasa específica de crecimiento celular (µ) en batch igual a 0,056 [h-1], desde la cual se propusieron 4 flujos de operación para el modo continuo, los cuales fueron de 0,9 1,8 2,7 y 3,6 [mL/min]. Con ellos en operación, se registraron las mismas variables evaluadas en batch, además de determinar el tiempo requerido para estabilizar el pH, medida usada en la detección de cada estado estacionario. Los registros variaron al aumentar el flujo, observando que las cantidades de ácido, sulfato y células disminuyeron, aumentando el pH en el biorreactor. Por su parte, el tiempo transiente necesario para alcanzar cada estacionario se situó en un rango entre 24 y 40 [horas]. A partir de los resultados de producción de ácido sulfúrico y sulfato en solución, se generó un modelo similar a los utilizados en fermentadores continuos, asumiendo la existencia de dos tipos de células: las adheridas al azufre y las suspendidas en el medio de reacción (planctónicas). El modelo se trabajó ignorando el crecimiento de las arqueas en suspensión, y siguiendo dos casos de estudio: suponer una tasa µ constante para todos los flujos versus un caso de µ variable por flujo. El modelo entregó valores para la tasa específica de crecimiento (el mejor de 0,022 [h-1]), además del rendimiento de producción por arquea (alrededor de 10-10 [g producto/arquea]). Este último resultado fue similar al utilizar ácido sulfúrico o sulfato indistintamente como medidas de producto. Además, un estudio de la aireación reveló que el sistema poseía un nivel de oxígeno adecuado para la operación, estimando una producción máxima posible de 0,0014 [g/min] de ácido sulfúrico. En conclusión, el sistema implementado resultó ser un exitoso primer acercamiento a la tecnología de reactores utilizando Sulfolobus metallicus creciendo sobre azufre elemental a 67°C, y debe someterse a un estudio de ingeniería más acabado, tal que permita realizar una biooxidación de azufre compatible con la necesidad de una lixiviación sostenible de fosfatos.
Books on the topic "Escape Reaction"
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1936-, Taylor Laurie, ed. Escape attempts: The theory and practice of resistance to everyday life. London: Routledge, 2002.
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Hinton, David A. Relative merits of reactive and forward-look detection for wind-shear encounters during landing approach for various microburst escape strategies. [Washington, DC]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Division, 1990.
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Escape Attempts: The Theory and Practice of Resistance in Everyday Life. Taylor & Francis Group, 2003.
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Escape Attempts: The Theory and Practice of Resistance in Everyday Life. Taylor & Francis Group, 2003.
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Escape Attempts: The Theory and Practice of Resistance in Everyday Life. Taylor & Francis Group, 2003.
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(Editor), W. Scott McGraw, Klaus Zuberbühler (Editor), and Ronald Noë (Editor), eds. Monkeys of the Taï Forest: An African Primate Community (Cambridge Studies in Biological and Evolutionary Anthropology). Cambridge University Press, 2008.
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Chapman, Mark. Political Transformations. Edited by Joel D. S. Rasmussen, Judith Wolfe, and Johannes Zachhuber. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780198718406.013.3.
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Beginning with the French Revolution and the Enlightenment and their effects on the political life and systems of Europe, this chapter discusses the broader impact of the collapse of the political systems in Germany, the modernization of the regimes, as well as the attempts at restoration after the defeat of Napoleon. The author examines conservative and neo-confessional movements, as well as the increasing secularization of societies in Western Europe. Following the increasing success of nationalism in the Austrian, Russian, and Turkish Empires and in the Italian peninsula, the chapter traces its impact on the development of ultramontanism. Responses by Christian thinkers to political transformations are grouped under the three headings of accommodation, reaction, and escape. The chapter concludes by suggesting that the growing autonomy of both the political and ecclesial systems provided the background for the increasing irrelevance of the churches in the twentieth century.
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Newton, Hannah. ‘Pluck’t from the Pit’. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198779025.003.0006.
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Recovery was often experienced as a narrow escape from death. ‘I was snatch’d out of the very Jaws of Death!’, exclaimed Thomas Steward from Suffolk in 1699. While historians have examined emotional responses to the prospect of death, little has been said about reactions to not dying; this new angle sheds fresh light on attitudes to both life and death. Patients usually expressed great joy, and gave three reasons for doing so: the relief of the body and soul not to have to part; the desire to remain in the ‘land of the living’; and the opportunity to ‘improve’ one’s salvation. Occasionally, however, owing to beliefs in the superiority of heaven over earth, patients felt disappointed not to die! This chapter also discusses families’ reactions, showing that their feelings varied according to their relationship with the patient, and the timing and means through which they heard of the survival.
Book chapters on the topic "Escape Reaction"
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Krasne, Franklin B. "Crayfish, Escape Reaction, Lateral Giant Neuron-Mediated." In Comparative Neuroscience and Neurobiology, 26–27. Boston, MA: Birkhäuser Boston, 1988. http://dx.doi.org/10.1007/978-1-4899-6776-3_10.
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Van Den Broeck, C., and J. M. R. Parrondo. "First Passage Time Renormalization and Escape from an Imperfect Trap." In New Trends in Kramers’ Reaction Rate Theory, 177–88. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0465-4_8.
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Reimann, Peter, and Peter Talkner. "Invariant Densities and Escape Rates for Maps with Weak Gaussian Noise." In New Trends in Kramers’ Reaction Rate Theory, 143–75. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0465-4_7.
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Krasne, Franklin B., Eric T. Vu, and Sunhee C. Lee. "The Excitability of the Crayfish Lateral Giant Escape Reaction: Inhibitory Control of the Lateral Giant Dendrites." In Frontiers in Crustacean Neurobiology, 316–22. Basel: Birkhäuser Basel, 1990. http://dx.doi.org/10.1007/978-3-0348-5689-8_37.
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Holcman, David, and Zeev Schuss. "Markov Models for Stochastic Chemical Reactions." In Stochastic Narrow Escape in Molecular and Cellular Biology, 143–68. New York, NY: Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4939-3103-3_6.
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Vini, Ravindran, Sreeja Sreekumar, Juberiya M. Azeez, and Sreeja Sreeharshan. "Pomegranate Extract Protects Endothelial Cells from TNF-α Associated Damage." In Proceedings of the Conference BioSangam 2022: Emerging Trends in Biotechnology (BIOSANGAM 2022), 276–89. Dordrecht: Atlantis Press International BV, 2022. http://dx.doi.org/10.2991/978-94-6463-020-6_27.
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AbstractPomegranates are known for being rich in polyphenols and are considered to have immense therapeutic potential. The present study investigates the hypothesis that the Methanolic Extract of Pomegranate (PME), a rich source of antioxidants, may reverse the adverse effects of TNF-α in endothelial cells. This was done by pre-treating the endothelial cells EA.hy926 with PME (80 µg/ml) before subjecting them to apoptotic stimuli, which was TNF-α in combination with cyclohexamide. PME was found to rescue a population of cells from apoptosis induced by TNF-α modulating the levels of BCL2 and BAX involved in intrinsic apoptotic pathway. PME was found to increase the BCL-2/BAX ratio and reverse the elevated levels of effector caspase and thus assist cells to escape from apoptotic stimuli. Also, the extract was found to attenuate oxidative stress by reducing the levels of Reactive Oxygen Species (ROS). Supplementing its anti-atherosclerotic potential, PME pre-treatment diminished the elevated levels of adhesion molecules like VCAM upon TNF-α treatment. PME may therefore have therapeutic implications in protecting the endothelium from TNF-α triggered atherosclerosis.
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"A CHEMICAL REACTION." In Escape from Dannemora, 24–35. University Press of New England, 2017. http://dx.doi.org/10.2307/j.ctv1xx9b3d.6.
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Harrison, Dr Mark. "Inflammatory response." In Revision Notes for MCEM Part A, 489–93. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199583836.003.0054.
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1.1 Normal vs. abnormal, 492 1.2 Inflammatory markers, 496 • Initial reaction of tissue to ‘injury’ ▪ Vascular phase: Dilatation and increased permeability ▪ Exudative phase: Fluid and cells escape from the permeable vessels ▪ Ends with: Resolution, suppuration, organization, progression to chronic inflammation...
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Atkins, Peter. "Irritating Atmospheres: Atmospheric Photochemistry." In Reactions. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199695126.003.0030.
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The problem of photochemically generated smog begins inside internal combustion engines, where at the high temperatures within the combustion cylinders and the hot exhaust manifold nitrogen molecules and oxygen molecule combine to form nitric oxide, NO. Almost as soon as it is formed, and when the exhaust gases mingle with the atmosphere, some NO is oxidized to the pungent and chemically pugnacious brown gas nitrogen dioxide, NO2, 1. We need to watch what happens when one of these NO2 molecules is exposed to the energetic ultraviolet photons in sunlight. We see a photon strike the molecule and cause a convulsive tremor of its electron cloud. In the brief instant that the electron cloud has swarmed away from one of the bonding regions, an O atom makes its escape, leaving behind an NO molecule. We now continue to watch the liberated O atom. We see it collide with an oxygen molecule, O2, and stick to it to form ozone, O3, 2. This ozone is formed near ground level and is an irritant; ozone at stratospheric levels is a benign ultraviolet shield. Now keep your eye on the ozone molecule. In one instance we see it collide with an NO molecule, which plucks off one of ozone’s O atoms, forming NO2 and letting O3 revert to O2. Another fate awaiting NO2 is for it to react with oxygen and any unburned hydrocarbon fuel and its fragments that have escaped into the atmosphere. We can watch that happening too where the air includes surviving fragments of hydrocarbon fuel molecules. A lot of little steps are involved, and they occur at a wide range of rates. Let’s suppose that some unburned fuel escapes as ethane molecules, CH3CH3, 3. Although ethane is not present in gasoline, a CH3CH2· radical (Reaction 12) would have been formed in its combustion and then combined with an H atom in the tumult of reactions going on there. You already know that vicious little O atoms are lurking in the sunlit NO2-ridden air. We catch sight of one of their venomous acts: in a collision with an H2O molecule they extract an H atom, so forming two ·OH radicals.
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Henley, David, Thomas Upton, and Stafford L. Lightman. "The Endocrine Response to Stress." In Oxford Textbook of Endocrinology and Diabetes 3e, edited by John A. H. Wass, Wiebke Arlt, and Robert K. Semple, 1687–93. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780198870197.003.0203.
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Reaction to stress is characterized by a series of interlinked, dynamic, and organized responses that function to restore homeostasis. Rapid activation of the sympathoadrenomedullary and hypothalamic–pituitary–adrenal (HPA) axes occurs following acute stress exposure in order to appropriately respond to, adapt, or escape the threat. The dynamic, pulsatile nature of the HPA axis is crucial to the function of glucocorticoids which modulate many of the complex neurocognitive and physiological changes that occur in acute and chronic stress states. Maladaptive long-term activation of the stress response is associated with numerous pathological states including mood and sleep disorders, obesity, and metabolic syndrome. The altered stress dynamics that occur in critical illness remain poorly understood.
Conference papers on the topic "Escape Reaction"
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de Boeij, Wim P., Maxim S. Pshenichnikov, Koos Duppen, and Douwe A. Wiersma. "Femtosecond Photon Echo Study of Solution Dynamics Using a Cavity-Dumped Ti:sapphire Laser." In International Conference on Ultrafast Phenomena. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/up.1994.me.2.
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It has long been recognized that a better grasp of solution dynamics is essential to our understanding of chemical reactions in the liquid phase. A prime example of reaction dynamics is the so-called "cage" effect, where products of a fragmentation reaction cannot escape from one another because of collisions with solvent molecules. A more profound understanding of this phenomenon and other solvent dynamics, like solvation, remains a formidable challenge and is at the heart of physical chemistry.
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Wang, Xiaolin, Suraj C. Zunjarrao, Hui Zhang, and Raman P. Singh. "Advanced Process Model for Polymer Pyrolysis and Uranium Ceramic Material Processing." In 14th International Conference on Nuclear Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/icone14-89099.
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Silicon carbide (SiC) based uranium ceramic material can be fabricated as hosts for ultra high temperature applications, such as gas-cooled fast reactor fuels and in-core materials. A pyrolysis-based material processing technique allows for the fabrication of SiC based uranium ceramic materials at a lower temperature compared to sintering route. Modeling of the process is considered important for optimizing the fabrication and producing material with high uniformity. This study presents a process model describing polymer pyrolysis and uranium ceramic material processing, including heat transfer, polymer pyrolysis, SiC crystallization, chemical reactions, and species transport of a porous uranium oxide mixed polymer. Three key reactions for polymer pyrolysis and one key reaction for uranium oxide polymer interaction are established for the processing. Included in the model formulation are the effects of transport processes such as heat-up, polymer decomposition, and volatiles escape. The model is capable of accurately predicting the polymer pyrolysis and chemical reactions of the source material. Processing of a sample with certain geometry is simulated. The effects of heating rate, particle size and volume ratio of uranium oxide and polymer on porosity evolution, species uniformity, reaction rate are investigated.
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Meyer, Terrence R., Sukesh Roy, Sivaram P. Gogineni, Vincent M. Belovich, Edwin Corporan, and James R. Gord. "OH PLIF and Soot Volume Fraction Imaging in the Reaction Zone of a Liquid-Fueled Model Gas-Turbine Combustor." In ASME Turbo Expo 2004: Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-54318.
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Simultaneous measurements of OH planar laser-induced fluorescence (PLIF) and laser-induced incandescence (LII) are used to characterize the flame structure and soot formation process in the reaction zone of a swirl-stabilized, JP-8-fueled model gas-turbine combustor. Studies are performed at atmospheric pressure with heated inlet air and primary-zone equivalence ratios from 0.55 to 1.3. At low equivalence ratios (φ < 0.9), large-scale structures entrain rich pockets of fuel and air deep into the flame layer; at higher equivalence ratios, these pockets grow in size and prominence, escape the OH-oxidation zone, and serve as sites for soot inception. Data are used to visualize soot development as well as to qualitatively track changes in overall soot volume fraction as a function of fuel-air ratio and fuel composition. The utility of the OH-PLIF and LII measurement system for test rig diagnostics is further demonstrated for the study of soot-mitigating additives.
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Scott, T. W., and S. N. Liu. "Picosecond cage recombination measurements of polyatomic free radical pairs." In International Laser Science Conference. Washington, D.C.: Optica Publishing Group, 1986. http://dx.doi.org/10.1364/ils.1986.thl51.
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Geminate free radical recombination is an important testing ground for current theories of chemical reaction dynamics in liquids. The work described here deals with the recombination of phenyl thiyl radicals in liquid hydrocarbons. Photolysis of diphenyl disulfides using near-ultraviolet light generates thiyl radicals which are detected by picosecond transient absorption spectroscopy. We find that the rate and extent of cage recombination is controlled by solvent viscosity and by the dipole-dipole reorientation energy of a polar radical pair. In moderately viscous liquids such as decalin, for example, cage recombination occurs with a 50% yield and with a half-life of ~150 ps. The influence of both temperature and solvent composition on recombination can be explained by a simple hydrodynamic model of diffusion controlled reactions, using a radiation boundary condition that mimics the reorientation barrier. In polar liquids, cage escape is enhanced by solvation of the radical pair. Based on the interpretation of these experiments it appears that the use of chemical substituents to alter the dipole movement of the radical can be used to study the recombination dynamics in more detail.
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Stanoevska-Slabeva, Katarina, and Bozena Mierzejewska. "Can Escapist Use of Facebook be Triggered by Facebook Push Notification?" In Digital Restructuring and Human (Re)action. University of Maribor Press, 2022. http://dx.doi.org/10.18690/um.fov.4.2022.11.
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In this paper, the unplanned and spontaneous use of Facebook (FB) triggered by FB push notification (FPN) is explored. The concept of triggered FB use was introduced as a new type of FB use that is provoked intentionally by FB via personalized FPN. The results presented in the paper show that FPN are powerful instruments to get users back to FB. Even though FPN typically trigger users with one specific announcement, most users that react on them get immersed by the broad and persuasive offerings of FB and stay longer on the platform than it is necessary to act upon the activities promoted by the FPN. These longer stays often show escapist characteristics. Thus, FPN provide users an opportunity to escape spontaneously from the current activities and psychological states when FPN arrive. Positive gratification resulting from such spontaneous visits lays the ground for future positive reaction on FPN as users try to repeat the rewarding experience.
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White, David J., and Richard T. LeCren. "Deposition From a Coal-Water Slurry Fueled Gas Turbine Combustor." In 1985 Joint Power Generation Conference: GT Papers. American Society of Mechanical Engineers, 1985. http://dx.doi.org/10.1115/85-jpgc-gt-15.
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A two-stage coal-water slurry fueled high-pressure gas turbine combustion system employing a primary zone with a hot refractory wall and an internal slag removal system has been designed, built and tested. The molten ash or slag is largely removed internally by aerodynamic means using a form of jet impaction. Some small amount of the mineral matter in the coal, however, does escape the primary zone and exits the combustor. The overall combustion system is extremely flexible and can be readily configured to operate either with a lean or a rich reaction (primary) zone. In most cases a rich primary zone and a lean secondary zone is used. Results showing the emission signatures of a number of coal-water slurry fuels operating with the combustor arranged in a rich primary zone configuration have been presented in a previous paper (1). NOx emissions were obtained that meet EPA regulations for stationary gas turbines. Deposition on a rig simulation of a turbine nozzle guide vane has been measured. The deposition appears to be a strong function of coal type and ash composition.
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Guo, Hang, Yue Ping Chen, Yan Qing Xue, Fang Ye, and Chong Fang Ma. "Three-Dimensional Numerical Simulation of Mass Transfer in Cathode Side of a Passive Direct Methanol Fuel Cell." In ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2012 6th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fuelcell2012-91524.
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A three-dimensional, two-phase, multiple-component, unsteady model for mass transport at the cathode side of a passive direct methanol fuel cell was developed. We assumed that the cathode was full of dry air at the beginning. The air diffuses through the cathode diffusion layer to the cathode catalyst layer where electrochemical reaction occurred. The liquid water which generated in the cathode catalyst layer is gradually moved out of the cathode catalyst layer by diffusion and gas carrying. The numerical results indicate that at the constant current density of 100 mA/cm2, the quantity of liquid water increases firstly and then keeps in a constant in both cathode diffusion layer and cathode catalyst layer while that continually rises in the air cavity. This phenomenon is caused by the gravitational effect. Under normal gravity, the liquid water flows down in the cathode catalyst layer and accumulates at the bottom. When the gravitational effect is greater than the viscous forces, the liquid water droplets escape from the cathode diffusion layer and then fall into air cavity. The distributions of species concentration and velocities along different directions are also presented.
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Nguyen, Khe C., Sinh T. Do, and Thong V. De. "Novel Proton Exchange Membrane Utilizing Nano Composite for Fuel Cell Application." In ASME 2006 Multifunctional Nanocomposites International Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/mn2006-17013.
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In the present report, we conducted the study of chemical top down process which seems to provide better efficiency and better cost saving than the physical top down in the fabrication of nano scale, especially, when applying to carbon materials. It is found that the chemical top down performs effectively with multiple attachments of electrolytic groups onto the surface of the carbon powder by diazo coupling reaction. As a result, we are able to isolate the nano scale of carbon particles with strong polar solvents such as water and believe that it is due to electrostatic repulsive force between same sign charges existing in the polarized electrolytic groups... The cleavage of azo bond in a naked carbon product can occur above 110oC in ambient condition but can also escape by a nano composite structure using specific emulsion polymer as binder matrix. Electrolytic groups carry charge from ionization are proven to reduce electron transport but enhance proton transport capability of carbon material, have successfully demonstrated a proton exchange membrane (PEM) which exhibits better heat resistance and higher current density than the commercial Nafion product in the PEM fuel cell application. The diazo coupling product of carbon exhibits a core-shell structure composed of a nano scale hydrophobic core and electrolytic shell, showing apparent “solubility” and named as “liquid” nano carbon (LNC).
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Lee, Shuo-Jen, and Jian-Jang Lai. "Evaluation of Electrode Agitation Effects on Electropolishing Process." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60152.
Full textAbstract:
Electropolishing(EP) is a surface treatment process which improves the surface roughness and enhances the surface quality by electrochemical reactions. The system is composed of an anode, a cathode, a power supply and viscous electrolyte. From the electrochemical reactions, the anodic metallic dissolution will leave off the surface and formed a viscous layer to enhance the surface quality, especially in stainless steels. It improves for the chrome to iron ratio and reduces the surface activity to avoid the surface corrosion from environment. From the anodic dissolution, the water may also be electrolyzed to form the hydrogen and oxygen bubbles on the anode and cathode plates. The viscous electrolyte causes the bubbles hard to escape from the gap between electrodes resulting ineffective natural convection and no idea about where and when of the viscous layer would be destroyed. So it is hard to predict the EP effects under natural convection during the EP process. It decreases the process stability as well as specimen surface quality. In this study, two methods of electrolyte agitation were employed to study their effects on electropolishing. The first method was by mechanical electrode movement. The second method was by ultrasonic agitation. The forced convection, generated by electrode movement and ultrasound, will accelerate the speed of bubbles leaving, breaking up from the surface and refreshing the electrolyte between electrodes. Thus, it may accomplish the goal of maintaining the stability of reaction environment during the EP process. The materials of both anode and cathode were SS316L stainless steel. The compositions and temperature of the electrolyte remained the same in each experiment. The control variables of experiments were electrode gap, rotational speed, amplitude of electrode movement and polishing time in mechanical agitation experiments. Frequency and amplitude of ultrasound were the control variables in the ultrasound experiment. The surface quality indicators were surface roughness and qualitative microscopic evaluation of surface morphology. According to the variations of surface quality indicators, the parametric effects on EP process will be analyzed. And the effectiveness of electrolytic agitation method on the surface quality and process stability were evaluated.
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Arkin, Ronald C., and William M. Carter. "Active avoidance: escape and dodging behaviors for reactive control." In Aerospace Sensing, edited by Kevin W. Bowyer. SPIE, 1992. http://dx.doi.org/10.1117/12.58611.
Full textReports on the topic "Escape Reaction"
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Bull, Benedicte. A Social compromise for the Anthropocene? Elite reactions to the Escazú Agreement and the prospects for a Latin American transformative green state. Fundación Carolina, October 2022. http://dx.doi.org/10.33960/issn-e.1885-9119.dtfo07en.
Full textAbstract:
The world is urgently facing the need for a “green transformation”, involving not only a transition towards the use renewable energy and reduction of biodiversity loss, but a deep social change towards social justice and sustainability. Such action requires social compromises between elites and popular sectors that allow the building of strong institutions to implement changes. Latin America is faced with huge tasks to increase equality, justice and sustainability, but it also plays a pivotal role in the global green transformation. The region is further characterized by both strong elites, strong socio-environmental movements and deep environmental conflicts making social compromises difficult. This Working Paper discusses elite reactions to the most advanced regional agreement on environmental regulation and conflict resolution, the Escazù Agreement. In many countries, elites opposed it vehemently referring to national sovereignty, but particularly rejecting the institutional implications of the agreement involving a stronger compromise to allow popular participation. This was opposed by economic elites in democratic countries (Chile, Colombia, Costa Rica and Peru) as well as governmental elites in authoritarian countries (El Salvador and Venezuela). However, in various cases, elite opposition was overcome after popular mobilization and dialogue. The paper discusses what we can learn from elite reactions to the Escazú Agreement of importance for future social compromises as a basis for the emergence for transformative states in Latin America.
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Brophy, Kenny, and Alison Sheridan, eds. Neolithic Scotland: ScARF Panel Report. Society of Antiquaries of Scotland, June 2012. http://dx.doi.org/10.9750/scarf.06.2012.196.
Full textAbstract:
The main recommendations of the Panel report can be summarised as follows: The Overall Picture: more needs to be understood about the process of acculturation of indigenous communities; about the Atlantic, Breton strand of Neolithisation; about the ‘how and why’ of the spread of Grooved Ware use and its associated practices and traditions; and about reactions to Continental Beaker novelties which appeared from the 25th century. The Detailed Picture: Our understanding of developments in different parts of Scotland is very uneven, with Shetland and the north-west mainland being in particular need of targeted research. Also, here and elsewhere in Scotland, the chronology of developments needs to be clarified, especially as regards developments in the Hebrides. Lifeways and Lifestyles: Research needs to be directed towards filling the substantial gaps in our understanding of: i) subsistence strategies; ii) landscape use (including issues of population size and distribution); iii) environmental change and its consequences – and in particular issues of sea level rise, peat formation and woodland regeneration; and iv) the nature and organisation of the places where people lived; and to track changes over time in all of these. Material Culture and Use of Resources: In addition to fine-tuning our characterisation of material culture and resource use (and its changes over the course of the Neolithic), we need to apply a wider range of analytical approaches in order to discover more about manufacture and use.Some basic questions still need to be addressed (e.g. the chronology of felsite use in Shetland; what kind of pottery was in use, c 3000–2500, in areas where Grooved Ware was not used, etc.) and are outlined in the relevant section of the document. Our knowledge of organic artefacts is very limited, so research in waterlogged contexts is desirable. Identity, Society, Belief Systems: Basic questions about the organisation of society need to be addressed: are we dealing with communities that started out as egalitarian, but (in some regions) became socially differentiated? Can we identify acculturated indigenous people? How much mobility, and what kind of mobility, was there at different times during the Neolithic? And our chronology of certain monument types and key sites (including the Ring of Brodgar, despite its recent excavation) requires to be clarified, especially since we now know that certain types of monument (including Clava cairns) were not built during the Neolithic. The way in which certain types of site (e.g. large palisaded enclosures) were used remains to be clarified. Research and methodological issues: There is still much ignorance of the results of past and current research, so more effective means of dissemination are required. Basic inventory information (e.g. the Scottish Human Remains Database) needs to be compiled, and Canmore and museum database information needs to be updated and expanded – and, where not already available online, placed online, preferably with a Scottish Neolithic e-hub that directs the enquirer to all the available sources of information. The Historic Scotland on-line radiocarbon date inventory needs to be resurrected and kept up to date. Under-used resources, including the rich aerial photography archive in the NMRS, need to have their potential fully exploited. Multi-disciplinary, collaborative research (and the application of GIS modelling to spatial data in order to process the results) is vital if we are to escape from the current ‘silo’ approach and address key research questions from a range of perspectives; and awareness of relevant research outside Scotland is essential if we are to avoid reinventing the wheel. Our perspective needs to encompass multi-scale approaches, so that ScARF Neolithic Panel Report iv developments within Scotland can be understood at a local, regional and wider level. Most importantly, the right questions need to be framed, and the right research strategies need to be developed, in order to extract the maximum amount of information about the Scottish Neolithic.