Academic literature on the topic 'Thiele modulus'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Thiele modulus.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Thiele modulus"

1

Kennedy, K. J., and R. L. Droste. "Diffusional limitations of anaerobic biofilms." Canadian Journal of Civil Engineering 14, no. 5 (October 1, 1987): 631–37. http://dx.doi.org/10.1139/l87-093.

Full text
Abstract:
Using an empirical determination of apparent kinetic parameters in the bulk mixed liquor, the intrinsic kinetic parameters of anaerobic biofilms developed at 35 °C during start-up and steady-state downflow stationary fixed film reactor operation were estimated. The apparent kinetic parameters of anaerobic biofilms are not significantly influenced by internal diffusion limitations. The apparent kinetic parameters of mature biofilms showed no significant trends with increased biofilm thickness up to 2.6 mm and increased apparent Thiele modulus up to 3.1. Key words: anaerobic, biofilm kinetics, Thiele modulus, wastewater, filter.
APA, Harvard, Vancouver, ISO, and other styles
2

Hartmann, Martin, Albert Gonche Machoke, and Wilhelm Schwieger. "Catalytic test reactions for the evaluation of hierarchical zeolites." Chemical Society Reviews 45, no. 12 (2016): 3313–30. http://dx.doi.org/10.1039/c5cs00935a.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Markoš, Jozef, and Alena Brunovská. "Optimal catalyst activity distribution in fixed-bed reactor with catalyst deactivation." Collection of Czechoslovak Chemical Communications 54, no. 2 (1989): 375–87. http://dx.doi.org/10.1135/cccc19890375.

Full text
Abstract:
In this paper the influence of the active catalyst location in a pellet on fixed-bed catalytic reactor performance is described. The optimal activity distribution as a function of an economic parameter (ratio of product and catalyst costs), Thiele modulus and Damkohler number is estimated.
APA, Harvard, Vancouver, ISO, and other styles
4

Zhokh, Alexey, and Peter Strizhak. "Thiele modulus having regard to the anomalous diffusion in a catalyst pellet." Chaos, Solitons & Fractals 109 (April 2018): 58–63. http://dx.doi.org/10.1016/j.chaos.2018.02.016.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Sharma, Kritika, Shrihari Sankarasubramanian, Javier Parrondo, and Vijay Ramani. "Electrochemical implications of modulating the solvation shell around redox active organic species in aqueous organic redox flow batteries." Proceedings of the National Academy of Sciences 118, no. 34 (August 20, 2021): e2105889118. http://dx.doi.org/10.1073/pnas.2105889118.

Full text
Abstract:
Organic and organometallic reactants in aqueous electrolytes, being composed of earth-abundant elements, are promising redox active candidates for cost-effective organic redox flow batteries (ORFBs). Various compounds of ferrocene and methyl viologen have been examined as promising redox actives for this application. Herein, we examined the influence of the electrolyte pH and the salt anion on model redox active organic cations, bis((3-trimethylammonio) propyl)- ferrocene dichloride (BTMAP-Fc) and bis(3-trimethylammonio) propyl viologen tetrachloride (BTMAP-Vi), which have exhibited excellent cycling stability and capacity retention at ≥1.00 M concentration [E. S. Beh, et al. ACS Energy Lett. 2, 639–644 (2017)]. We examined the solvation shell around BTMAP-Fc and BTMAP-Vi at acidic and neutral pH with SO42-, Cl−, and CH3SO3− counterions and elucidated their impact on cation diffusion coefficient, first electron transfer rate constant, and thereby the electrochemical Thiele modulus. The electrochemical Thiele modulus was found to be exponentially correlated with the solvent reorganizational energy (λ) in both neutral and acidic pH. Thus, λ is proposed as a universal descriptor and selection criteria for organic redox flow battery electrolyte compositions. In the specific case of the BTMAP-Fc/BTMAP-Vi ORFB, low pH electrolytes with methanesulfonate or chloride counterions were identified as offering the best balance of transport and kinetic requirements.
APA, Harvard, Vancouver, ISO, and other styles
6

Zeynali, Mohammad Ebrahim, and S. Hakim. "Diffusion Processes Affecting the Performance of Heterogeneous Catalysts: Part 1." Defect and Diffusion Forum 319-320 (October 2011): 107–15. http://dx.doi.org/10.4028/www.scientific.net/ddf.319-320.107.

Full text
Abstract:
The diffusion processes taking place in heterogeneous catalytic systems have been discussed. Various diffusion mechanisms such as Knudsen diffusion, molecular diffusion, configurational diffusion and surface diffusion sensitivity in catalytic systems were investigated. The concentration gradients inside the catalyst pellet were obtained for various Thiele modulus. The Knudsen number was calculated and discussed for large and small pores. The transitional diffusion coefficient was determined for diethylbenzene. The experimental pore size distribution carves for an industrial and synthesized catalyst was obtained and the effect of pore size distribution on diffusion coefficient was discussed.
APA, Harvard, Vancouver, ISO, and other styles
7

UshaRani, Ramu, Lakshmanan Rajendran, and Marwan Abukhaled. "Approximations for the Concentration and Effectiveness Factor in Porous Catalysts of Arbitrary Shape: Taylor Series and Akbari-Ganji’s Methods." Mathematical Modelling of Engineering Problems 8, no. 4 (August 31, 2021): 527–37. http://dx.doi.org/10.18280/mmep.080405.

Full text
Abstract:
A mathematical model of reaction-diffusion problem with Michaelis-Menten kinetics in catalyst particles of arbitrary shape is investigated. Analytical expressions of the concentration of substrates are derived as functions of the Thiele modulus, the modified Sherwood number, and the Michaelis constant. A Taylor series approach and the Akbari-Ganji's method are utilized to determine the substrate concentration and the effectiveness factor. The effects of the shape factor on the concentration profiles and the effectiveness factor are discussed. In addition to their simple implementations, the proposed analytical approaches are reliable and highly accurate, as it will be shown when compared with numerical simulations.
APA, Harvard, Vancouver, ISO, and other styles
8

Driessen, Rick T., Sascha R. A. Kersten, and Derk W. F. Brilman. "A Thiele Modulus Approach for Nonequilibrium Adsorption Processes and Its Application to CO2 Capture." Industrial & Engineering Chemistry Research 59, no. 15 (January 17, 2020): 6874–85. http://dx.doi.org/10.1021/acs.iecr.9b05503.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Sharratt, P. N., and R. Mann. "Some observations on the variation of tortuosity with Thiele modulus and pore size distribution." Chemical Engineering Science 42, no. 7 (1987): 1565–76. http://dx.doi.org/10.1016/0009-2509(87)80161-6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Yang, Wei, Schalk Cloete, John Morud, and Shahriar Amini. "An Effective Reaction Rate Model for Gas-Solid Reactions with High Intra-Particle Diffusion Resistance." International Journal of Chemical Reactor Engineering 14, no. 1 (February 1, 2016): 331–42. http://dx.doi.org/10.1515/ijcre-2015-0127.

Full text
Abstract:
AbstractAn approximate analytical expression for estimating the effectiveness factors of non-catalytic gas-solid reactions is proposed. The new expression is derived from the analytical solution for simple first order reactions (Ishida and Wen 1968. Comparison of kinetic and diffusional models for solid-gas reactions. AIChE Journal 14, 311–317. http://dx.doi.org/10.1002/aic.690140218). The scaled Thiele modulus concept is introduced to account for the variations of the reaction rate form that differs from the first order. The validity of the new expression is demonstrated for the reactions of different orders and of different forms via comparisons against a complete particle-reactor model using the collocation method for solving heat and mass fluxes inside the particles. In addition, the proposed approach is applied to redox reactions of ferric oxide where non-isothermal condition, net consumption of gaseous reactant, and parallel reactions are encountered. The results show that the effectiveness factor method compared well with the orthogonal collocation method over a wide range of Thiele moduli, reaction orders and reaction forms. Therefore, the proposed expression can serve as a generic replacement for more complex and computationally expensive combined particle-reactor modelling which is often employed in reactor systems with significant intra-particle diffusion resistances.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Thiele modulus"

1

Morgado, Prates Ana Rita. "Hollow Beta zeolites : synthesis and impact of the hollow morphology on diffusion and catalysis." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1155/document.

Full text
Abstract:
De par leur morphologie, les cristaux creux de zéolithe permettent d’étudier les phénomènes de limitations diffusionnelles en catalyse et également d’encapsuler des particules métalliques ; les nano-réacteurs ainsi obtenus ont montré des activités catalytiques originales. Leur synthèse, qui nécessite des caractéristiques structurales particulières, a longtemps été limitée aux zéolithes de structure MFI. Le but de cette thèse était d’étudier différentes voies de synthèse pour préparer des cristaux creux de zéolithe Beta, une des zéolithes les plus utilisées dans l’industrie. Deux voies ont été suivies : l’utilisation d’un zincosilicate de même structure que la zéolithe Beta comme gabarit sacrificiel et une méthode plus classique de désilication sélective. L’encapsulation de nanoparticules de platine dans les cristaux obtenus selon la première voie a été confirmée par l’hydrogénation d’aromatiques substitués. L’’influence de la morphologie sur la diffusion de différentes molécules a été étudiée par ZLC : le temps caractéristique de diffusion a été réduit de 30 à 83 % par rapport à des cristaux conventionnels. Malgré cela, la présence d’une cavité dans les cristaux de zéolithe Beta n’a pas d’effets sur l’activité catalytique dans les réactions d’hydro-isomérisation du nC16 et du craquage du cyclohexane. La thèse discute de la présence/absence de limitations diffusionnelles
Hollow zeolite single crystals have received particular interest in catalysis. The presence of a large cavity in these model zeolites enables the study of diffusional limitation in Catalysis. The cavity also enables the encapsulation of metal nanoparticles. However, their synthesis requires specific structural characteristics and it has been limited for long to zeolites with the MFI structure. The objective of this PhD work was to investigate the synthesis of hollow Beta zeolites (*BEA framework type) and study the impact of the hollow morphology on molecular diffusion and catalysis. Two different strategies have been envisaged: a dissolution/recrystallization approach using CIT-6, a zincosilicate with the same *BEA topology and a selective desilication route. Pt nanoparticles encapsulated in hollow crystals obtained from CIT-6 showed remarkable size-selectivity in the hydrogenation of aromatics. The effect of the hollow morphology in molecular diffusion was studied using the ZLC technique; the characteristic diffusion time of the hollow morphology was reduced by 30-83% compared to the corresponding bulk zeolite. Despite that, the hollow structure had no influence on the catalytic activities for the hydroisomerization of n-C16 and for the cracking of cyclohexane. The presence/absence of diffusional limitation is discussed
APA, Harvard, Vancouver, ISO, and other styles
2

Godongwana, Buntu. "Effect of nutrient momentum and mass transport on membrane gradostat reactor efficiency." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2149.

Full text
Abstract:
Thesis submitted in fulfilment of the requirements for the degree Doctor technologiae (engineering: chemical) In the faculty of engineering at the cape peninsula university of technology
Since the first uses of hollow-fiber membrane bioreactors (MBR’s) to immobilize whole cells were reported in the early 1970’s, this technology has been used in as wide ranging applications as enzyme production to bone tissue engineering. The potential of these devices in industrial applications is often diminished by the large diffusional resistances of the membranes. Currently, there are no analytical studies on the performance of the MBR which account for both convective and diffusive transport. The purpose of this study was to quantify the efficiency of a biocatalytic membrane reactor used for the production of enzymes. This was done by developing exact solutions of the concentration and velocity profiles in the different regions of the membrane bioreactor (MBR). The emphasis of this study was on the influence of radial convective flows, which have generally been neglected in previous analytical studies. The efficiency of the MBR was measured by means of the effectiveness factor. An analytical model for substrate concentration profiles in the lumen of the MBR was developed. The model was based on the solution of the Navier-Stokes equations and Darcy’s law for velocity profiles, and the convective-diffusion equation for the solute concentration profiles. The model allowed for the evaluation of the influence of both hydrodynamic and mass transfer operating parameters on the performance of the MBR. These parameters include the fraction retentate, the transmembrane pressure, the membrane hydraulic permeability, the Reynolds number, the axial and radial Peclet numbers, and the dimensions of the MBR. The significant findings on the hydrodynamic studies were on the influence of the fraction retentate. In the dead-end mode it was found that there was increased radial convective flow, and hence more solute contact with the enzymes/biofilm immobilised on the surface of the membrane. The improved solute-biofilm contact however was only limited to the entrance half of the MBR. In the closed shell mode there was uniform distribution of solute, however, radial convective flows were significantly reduced. The developed model therefore allowed for the evaluation of an optimum fraction retentate value, where both the distribution of solutes and radial convective flows could be maximised.
APA, Harvard, Vancouver, ISO, and other styles
3

Greene, Tanja L. "Modular crosslinking of gelatin based thiol-norbornene hydrogels for in vitro 3D culture of hepatic cells." Thesis, ACS Biomaterials Science and Engineering, 2015. http://hdl.handle.net/1805/9929.

Full text
Abstract:
Indiana University-Purdue University Indianapolis (IUPUI)
As liver disease becomes more prevalent, the development of an in vitro culture system to study disease progression and its repair mechanisms is essential. Typically, 2D cultures are used to investigate liver cell (e.g., hepatocyte) function in vitro; however, hepatocytes lose function rapidly when they were isolated from the liver. This has promoted researchers to develop 3D scaffolds to recreate the natural microenvironment of hepatic cells. For example, gelatin-based hydrogels have been increasingly used to promote cell fate processes in 3D. Most gelatin-based systems require the use of physical gelation or non-specific chemical crosslinking. Both of these methods yield gelatin hydrogels with highly interdependent material properties (e.g., bioactivity and matrix stiffness). The purpose of this thesis research was to prepare modularly crosslinked gelatin-based hydrogels for studying the influence of independent matrix properties on hepatic cell fate in 3D. The first objective was to establish tunable gelatin-based thiol-norbornene hydrogels and to demonstrate that the mechanical and biological properties of gelatin hydrogels can be independently adjusted. Furthermore, norbornene and heparin dual-functionalized gelatin (i.e., GelNB-Hep) was prepared and used to sequester and slowly release hepatocyte growth factor (HGF). The second objective was to investigate the viability and functions of hepatocytes encapsulated in gelatin-based hydrogels. Hepatocellular carcinoma cells, Huh7, were used as a model cell type to demonstrate the cytocompatibility of the system. The properties of GelNB hydrogels were modularly tuned to systematically evaluate the effects of matrix properties on cell viability and functions, including CYP3A4 activity and urea secretion. The last objective was to examine the effect of heparin immobilization on hepatocyte viability and functions. The conjugation of heparin onto GelNB led to suppressed Huh7 cell metabolic activity and improved hepatocellular functions. This hybrid hydrogel system should provide a promising 3D cell culture platform for studying cell fate processes.
APA, Harvard, Vancouver, ISO, and other styles
4

Schönrock, Michael [Verfasser], Bodo [Akademischer Betreuer] Laube, and Gerhard [Akademischer Betreuer] Thiel. "Modular design of ionotropic glutamate receptors: Coupling of a viral K+-channel with a glutamate-binding domain / Michael Schönrock ; Bodo Laube, Gerhard Thiel." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2019. http://d-nb.info/1182537499/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Davis, Linda. "'N Kriminologiese ondersoek na motorvoertuigkaping met spesifieke verwysing na slagoffervatbaarheid, slagofferaandadigheid en die modus operandi van die oortreder." Thesis, Pretoria : [s.n.], 1999. http://upetd.up.ac.za/thesis/available/etd-03242004-103416/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Morodi, Lebogang Richard. "Juvenile perceptions of shop theft in the Mabopane area." Diss., 2004. http://hdl.handle.net/10500/1396.

Full text
Abstract:
This research is a exploratory and descriptive study based on juvenile's perceptions with regard to shop theft. Secondary data sources were consulted to supplement the empirical data collected by means of a comprehensive questionnaire. Five hundred learners from grades 10, 11 and 12 in Mabopane were selected for the completion of the questionnaires. Shop theft was further elucidated by the application of criminological theories to explain research findings by highlighting their relationship with shop theft. Main research findings established that there are significant statistical differences with regard to the learner gender, age and grade as far as their views on shop theft were concerned. Recommendations based on the findings include teaching Criminology at secondary schools, the development of an anti shop theft youth oriented crime prevention program, shop theft educational and awareness programmes, and shoplifter offender prevention programs.
Criminology
M.A. (Criminology)
APA, Harvard, Vancouver, ISO, and other styles
7

Liebenberg, Andre Sarel. "An evaluation of the impact of the Non-ferrous Metals Crime Combating Committee on copper cable theft." Thesis, 2020. http://hdl.handle.net/10500/27467.

Full text
Abstract:
English, Zulu and Northern Sotho summaries
This study aims to evaluate the Non-Ferrous Metals Crime Combating Committee's impact on combating copper cable theft in South Africa. Data was collected via in-depth interviews with awaiting trial detainees charged with copper cable theft at the Pollsmoor Correctional Centre in the Western Cape; members of the Mpumalanga and Gauteng Provincial Non-Ferrous Metals Crime Combating Committee; members of Business Against Crime South Africa; and investigators attached to Combined Private Investigations who investigate copper theft nationally. The in-depth interviews provided a comprehensive understanding of participant experiences relating to the impact of the Non-Ferrous Metals Crime Combating Committee on the combating of copper cable theft in South Africa. Moreover, the researcher performed a thorough literature study of the phenomenon locally and internationally. Research findings indicate shortcomings in the Non-Ferrous Metals Crime Combating Committee's effectiveness, limiting its impact on preventing copper cable theft. Based on these findings, the study recommends that the Non-Ferrous Metals Crime Combating Committee be replaced with a specialised South African Police Service Non-Ferrous Metals Theft Unit. Consequently, this study puts forward a set of recommendations proposing a systematic pro-active plan to address and minimise copper cable theft in South Africa. The proposed plan convincingly presents practical solutions to minimise copper cable theft and contributes to the current body of scholarship on copper cable theft in South Africa.
Inhloso yalolu cwaningo ukuhlola umthelela wohlelo lwe-Non-Ferrous Metals Crime Combating Committee mayelana nokuqedwa kokutshontshwa kwentambo yogesi (copper cable). Idatha iqoqwe ngokusebenzisa izinhlolovo ezijulile ezenziwa ngokusebenzisa iziboshwa eziboshelwe izintambo zikagesi ezisamele ukugwetshwa ejele lase Pollsmoor Correctional Centre ngaseNtshonalanga Kapa, amalunga eMpumalanga and Gauteng Provincial Non-Ferrous Metals Crime Combating Committee, amalunga eBusiness Against Crime South Africa kanye nabaphenyi abahambisana nophiko lweCombined Private Investigations oluphenya ukutshontshwa kwezintambo zikagesi ezweni lonke. Lezi zinhlolovo ezijulile zinikeze ulwazi olubanzi lwabadlalindima olumayelana nomthelela weNon-Ferrous Metals Crime Combating Committee mayelana nokuqedwa kokutshontshwa kwezintambo zikagesi. Ngaphezu kwalokho, umcwaningi wenze ucwaningo olunzulu lombhalo wobuciko mayelana nokutshontshwa kwezintambo zikagesi lapha ekhaya kanye nasemhlabeni wonke jikelele. Ulwazi olutholakele lukhombisa iziqi ezikhinyabeza ukusebenza kahle kweKomithi mayelana nokuvimbela umthelela walo mayelana nokutshontshwa kwezintambo zikagesi. Ngezizathu ezisuselwa phezu kwalolu lwazi, lolu cwaningo lubeka phambili isethi lezincomo ezinganceda iKomiti ekuqiniseni umthintela walo ngokuhlongoza uhlelo olugqugquzelayo lokunciphisa izinga lokutshontshwa kwezintambo zikagesi eNingizimu Afrika. Lolu hlelo oluhlongoziwe ngaphandle kokungabaza lwethula izixazululo ezenzeka empilweni yangempela ukunciphisa ukwetshiwa kwezintambo zikagesi kanti lokhu kunegalelo kwiziko lamanje futhi luqhubekisa iziko lamanje lwezifundo esimayelana nokwetshiwa kwezintambo zikagesi.
Maikemisetso a thutelo ye ke go lekola khuetso ya Komiti ya Twantsho ya Bosenyi bja Dimetale tse di Sego tsa Tshipi ka ga go lwantsha kutso ya megala ya koporo. Datha e kgobokeditswe ka mokgwa wa ditherisano tse di tseneletsego tseo di sepeditswego le mahodu a megala ya koporo ao a golegilwego ao a letetsego go sekiswa Senthareng ya Tshokollo ya Pollsmoor go la Kapa Bodikela, maloko a Diprofense tsa Mpumalanga le Gauteng a Komiti ya Twantsho ya Bosenyi bja Dimetale tse di sego tsa Tshipi, maloko a Dikgwebo tsa Kgahlanong le Bosenyi tsa Afrika Borwa le banyakisisi bao ba dirisanago le Dinyakisiso tsa Praebete tse Kopantswego tseo di nyakisisago kutso ya koporo kemong ya bosetshaba. Ditherisano tse di tseneletsego tse di file kwesiso ka botlalo ya maitemogelo a batseakarolo ye e sepelelanago le khuetso ya Komiti ya Twantsho ya Bosenyi bja Dimetale tse di sego tsa Tshipi ka ga go lwantsha kutso ya megala ya koporo. Gape, monyakisisi o dirile thutelo ya dingwalo ka botebo ya kutso ya megala ya koporo tikologong ya leagong le kemong ya boditshabatshaba. Dikhwetso tsa dinyakisiso di supa mafokodi ao a lebanego bokgoni bja Komiti tshitisong ya khuetso ya yona go kutso ya megala ya koporo. Go ya ka dikhwetso tse, thutelo ye e hlagisa sehlopha sa dikeletso tseo di ka thusago Komiti go tswetsa khuetso ya yona pele ka go sisinya leano la go itokisetsa seemo se ka diregago ka mokgwa wo o beakantswego go fokotsa kutso ya megala ya koporo ka Afrika Borwa. Leano leo le sisintswego le hlagisa ka mo go kgodisago ditharollo tse di ka phethagatswago go fokotsa kutso ya megala ya koporo ka gona la ba la seabe go le go tswetsa pele popego ya bjale ya borutegi ka ga kutso ya megala ya koporo.
Criminology and Security Science
Ph. D. (Criminal Justice)
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Thiele modulus"

1

Didier, Dorian, Felix Reiners, and Andreas N. Baumann. "Thietanes and Thietes: Monocyclic." In Reference Module in Chemistry, Molecular Sciences and Chemical Engineering. Elsevier, 2021. http://dx.doi.org/10.1016/b978-0-12-818655-8.00139-6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Xu, Jiaxi. "Thietanes and Thietes: Fused and Spiro-Ring Derivatives." In Reference Module in Chemistry, Molecular Sciences and Chemical Engineering. Elsevier, 2021. http://dx.doi.org/10.1016/b978-0-12-818655-8.00151-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Thiele modulus"

1

Zimmerman, William B. "Modelling Transport Limited Heterogeneous Chemistry in Microchannel Reactors." In ASME 7th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2004. http://dx.doi.org/10.1115/esda2004-58441.

Full text
Abstract:
Enchancing radial mixing in microchannel processing of two phase flows for is important so that this feature can be exploited to simplify the design of heterogeneous reaction schemes in microchannel processing. The asymptotic analysis here extends the concept of the Thiele modulus to be the controlling variable in non-uniform systems. We argue that a generalization of a Thiele modulus is the ratio of the time scale for the limiting transport step to the time scale for surface reaction. If the intrinsic kinetics are fast and the reaction nearly irreversible, the latter is actually controlled by mass transfer to the reacting phase. Our analysis methodology naturally identifies the Thiele moduli and reduces the order of the system so that analytic, closed form estimates of the reaction dynamics are found. For parametric optimization, such a form is a good guide. The applicability of this general methodology is argued for microchannel processing and supported by several published studies and experiments.
APA, Harvard, Vancouver, ISO, and other styles
2

Nagy, Endre. "Mass Transport Through Biocatalytic Membrane Reactors." In ASME 2008 9th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2008. http://dx.doi.org/10.1115/esda2008-59403.

Full text
Abstract:
A mathematical model and its solution were developed to calculate the mass transport through catalytic membrane layer by means of explicit, closed expressions even in the case of the nonlinear Michaelis-Menten reaction kinetics and/or of variable mass transport — diffusion coefficient, convective velocity — parameters. Some typical examples on the Thiele modulus, applying the Michaelis-Menten kinetics and its limiting cases, namely the first-order kinetic (KM≫cm) and zero-order kinetic (cm≫KM) are shown for the prediction of the concentration distribution and the mass transfer rates as a function of the reaction modulus, namely first-order- and the zero-order reactions. It was shown the significant differences of the results obtained by the three different reaction orders.
APA, Harvard, Vancouver, ISO, and other styles
3

Song, Shaozhen, Joyce Joy, Ruikang K. Wang, and Zhihong Huang. "Mapping tissue shear modulus on Thiel soft-embalmed mouse skin with shear wave optical coherence elastography." In SPIE BiOS, edited by Kirill V. Larin and David D. Sampson. SPIE, 2015. http://dx.doi.org/10.1117/12.2078289.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Sarlo, Rodrigo, and Donald Leo. "Airflow Sensing With Arrays of Hydrogel Supported Artificial Hair Cells." In ASME 2015 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/smasis2015-9014.

Full text
Abstract:
The hair cell is a biological sensor that uses microscopic hair-like structures to detect delicate motions of surrounding fluid. Inspired by this principle, we have created an artificial hair cell (AHC) sensory method based on biomolecular transduction for sensing spatial variations in air flow. The key feature of this method is the use of one-dimensional arrays built from modular AHC units which measure local velocity at different points in a flow profile. Each of the AHC units uses thinly extruded glass fibers as mechanical receptors of air velocity. Hair vibrations are converted to current via hydrogel-supported lipid bilayer membranes through their mechanocapacitive properties. Preliminary tests with linear arrays of three AHC units attempt to measure the air source profile with varying position and intensity. Each unit was fabricated with a hair of different length, giving it a unique vibrational response. This technique was inspired by how organisms use hair cells with tuned responses to mechanically process flow stimuli. A significant challenge in processing the sensors’ output was the limitation of one input channel on the current measurement unit, thus each sensor output had to be sent over the same channel. When several AHC units are excited simultaneously by an airflow, the resulting signal is a superposition of each sensor’s individual response. To separate the signals back into their individual measurements, the Hair Frequency Response Decomposition method is developed, which maps the spectral content of a combined output to the location of excitation in the array. This method takes advantage of the AHC’s high signal-to-noise ratio (compared to other membrane-based AHCs) and linear output response to flow velocity. Results show that the bilayers’ consistent spectral responses allow for an accurate localization of sensor excitation within the array. However, temporal variations in bilayer size affect sensitivity properties and make accurate flow velocity estimation difficult. Nevertheless, under stable bilayer conditions the measured velocity profiles matched closely with theoretical predictions. The implementation of the array sensing method demonstrates the sensory capability of bilayer-based AHC arrays, but highlights the difficulties of achieving consistent performance with bio-molecular materials.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography