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2011

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Articles 9871 - 9900 of 10326

Full-Text Articles in Physical Sciences and Mathematics

Evaluating The Use Of Flow-Through Larval Culture For The Eastern Oyster, Crassostrea Virginica, Stephanie L. Reiner Jan 2011

Evaluating The Use Of Flow-Through Larval Culture For The Eastern Oyster, Crassostrea Virginica, Stephanie L. Reiner

Dissertations, Theses, and Masters Projects

One system used for bivalve mollusc culture is flowthrough larval culture, which provides a continuous flow of food and seawater to the tank. Flowthrough culture enables larvae to be reared at stocking densities up to 100 larvae/mL, a characteristic that should recommend it as the culture system of choice for the East coast; however, Eastern oyster larvae have never been tested in flowthrough culture, discouraging implementation of the system. The thesis objectives are designed to address questions regarding the survival, growth, competent period, cell consumption, growth efficiency, and cell selection of oyster larvae reared in flowthrough culture. The objectives are: …


Abiotic Release Of Low Molecular Weight Nitrogen From Effluent Organic Nitrogen, Carolina P. Funkey Jan 2011

Abiotic Release Of Low Molecular Weight Nitrogen From Effluent Organic Nitrogen, Carolina P. Funkey

Dissertations, Theses, and Masters Projects

No abstract provided.


A Numerical Modeling Study Of Storm Surge And Inundation In The Chesapeake Bay During The November 2009 Mid-Atlantic Nor'easter, Jie Gao Jan 2011

A Numerical Modeling Study Of Storm Surge And Inundation In The Chesapeake Bay During The November 2009 Mid-Atlantic Nor'easter, Jie Gao

Dissertations, Theses, and Masters Projects

No abstract provided.


Book Review Of "Networks, Crowds, And Markets: Reasoning About A Highly-Connected World; Easley, D. And Kleinberg, J.; 2010, George K. Thiruvathukal Jan 2011

Book Review Of "Networks, Crowds, And Markets: Reasoning About A Highly-Connected World; Easley, D. And Kleinberg, J.; 2010, George K. Thiruvathukal

Computer Science: Faculty Publications and Other Works

A book review I wrote for CISE about the excellent textbook, Networks, Crowds and Markets, which I used as an anchor textbook in Honors 204 at Loyola University Chicago (Science and Society).


Java Smell Detector, Nitin Mathur Jan 2011

Java Smell Detector, Nitin Mathur

Master's Projects

“Code Smell” or “Bad Smell”, at the very least, is an indicator of badly written code and is often indicative of deeper problems in software design. In layman terms, it signals flaws in the core foundation or architecture of the software that can cause any number of more serious problems – from usability and runtime performance to supportability and enhancement. These problems can mostly be prevented by the systematic refactoring of the code. Refactoring is the process (and according to some, an ‘art’) of making incremental changes to existing source code to improve its nonfunctional attributes, without modifying its external …


On The Nature Of The Extremely Fast Optical Rebrightening Of The Afterglow Of Grb 081029, M. Nardini, J. Greiner, T. Krühler, R. Filgas, S. Klose, P. Afonso, C. Clemens, A. N. Guelbenzu, F. Olivares E., A. Rau, A. Rossi, Adria Updike, A. Küpcü Yoldas, A. Yoldas, D. Burlon, J. Elliott, D. A. Kann Jan 2011

On The Nature Of The Extremely Fast Optical Rebrightening Of The Afterglow Of Grb 081029, M. Nardini, J. Greiner, T. Krühler, R. Filgas, S. Klose, P. Afonso, C. Clemens, A. N. Guelbenzu, F. Olivares E., A. Rau, A. Rossi, Adria Updike, A. Küpcü Yoldas, A. Yoldas, D. Burlon, J. Elliott, D. A. Kann

Arts & Sciences Faculty Publications

Context. After the launch of the Swift satellite, the gamma-ray burst (GRB) optical light-curve smoothness paradigm has been questioned thanks to the faster and better sampled optical follow-up, which has unveiled a very complex behaviour. This complexity is triggering the interest of the whole GRB community. The GROND multi-channel imager is used to study optical and near-infrared (NIR) afterglows of GRBs with unprecedented optical and near-infrared temporal and spectral resolution. The GRB 081029 has a very prominent optical rebrightening event and is an outstanding example of the application of the multi-channel imager to GRB afterglows. Aims. Here we exploit the …


Reaction Of Cycloheptatriene Derivatives With 1,3-Diketones In The Presence Of Mn(Oac)_3, Mahi̇r Burak Südemen, Mustafa Zengi̇n, Hayri̇ye Genç, Meti̇n Balci Jan 2011

Reaction Of Cycloheptatriene Derivatives With 1,3-Diketones In The Presence Of Mn(Oac)_3, Mahi̇r Burak Südemen, Mustafa Zengi̇n, Hayri̇ye Genç, Meti̇n Balci

Turkish Journal of Chemistry

The reactions of some 1,3-dicarbonyl compounds with cycloheptatriene derivatives in the presence of Mn(OAc)_3 were examined. Cycloheptatriene forms mainly [2+3] and [6+3] dihydrofuran addition products derived from cycloheptatriene. However, the reaction of acetylacetone with cycloheptatriene substituted with an electron withdrawing group exclusively gave products derived from the norcaradiene structure. The formation mechanism of the products as well as the role of the substituent attached to cycloheptatriene is discussed.


Synthesis Of Some 2,3,6,8-Tetraarylimidazo[1,2-A]Pyrazine Derivatives By Using Either Reflux Or Microwave Irradiation Method, And Investigation Their Anticancer Activities, İsmai̇l Kayaği̇l, Şeref Demi̇rayak Jan 2011

Synthesis Of Some 2,3,6,8-Tetraarylimidazo[1,2-A]Pyrazine Derivatives By Using Either Reflux Or Microwave Irradiation Method, And Investigation Their Anticancer Activities, İsmai̇l Kayaği̇l, Şeref Demi̇rayak

Turkish Journal of Chemistry

In this study, some 2,3,6,8-tetraarylimidazo[1,2-a]pyrazine derivatives were synthesized by reacting 1-(2-aryl-2-oxoethyl)-2-aryloyl-4,5-diarylimidazoles from 2-aryloyl-4,5-diarylimidazole and 2-bromoacetophenone derivatives with ammonium acetate in acetic acid by using the method that was previously developed and repeatedly tested in our studies. Structural elucidation of the compounds was performed by IR, ^1H-NMR, and MASS spectroscopic data and elemental analysis results. Anticancer activities of selected compounds were evaluated and the noticeable activity values were reported.


Effect Of Cmc And Hpc Mixture On The Photocatalytic Activity Of Nd-Tio_2/Sio_2 Film Under Visible Light Irradiation, Parviz Aberoomand, Shahram Moradi, Susan Samadi, Mohammad Saber Tehrani, Mohammad Hadi Givianrad Jan 2011

Effect Of Cmc And Hpc Mixture On The Photocatalytic Activity Of Nd-Tio_2/Sio_2 Film Under Visible Light Irradiation, Parviz Aberoomand, Shahram Moradi, Susan Samadi, Mohammad Saber Tehrani, Mohammad Hadi Givianrad

Turkish Journal of Chemistry

Neodymium-titania/silica films were prepared by the sol-gel method with the addition of various amounts of hydroxy propyl cellulose (HPC) and 5.09 \times 10^{-5} g g^{-1}_{solution} of carboxy methyl cellulose (CMC) in saturated conditions. The porous Nd-TiO_2/SiO_2 was obtained after heat treatment for 2 h at 500 °C, with the surface area up to 276 m^2 g^{-1}, which was measured using the Brunauer, Emmett, and Teller (BET) method. Scanning electron microscopy (SEM) showed that the particle size of Nd-TiO_2/SiO_2 decreased and the microstructure of the film became loose in suitable conditions with the addition of CMC to HPC. Subsequently, the photocatalytic …


Synthesis And Characterisation Of Tris(2,4-Dinitrophenoxo)Monooxovanadium(V) And Its Complex Salts, Neeraj Sharma, Reena Sharma, Meena Kumari, Subhash Chaudhry Jan 2011

Synthesis And Characterisation Of Tris(2,4-Dinitrophenoxo)Monooxovanadium(V) And Its Complex Salts, Neeraj Sharma, Reena Sharma, Meena Kumari, Subhash Chaudhry

Turkish Journal of Chemistry

The monooxovanadium(V) complex of composition [VO(OC_6H_3(NO_2)_2-2,4)_3] (I) was synthesized by the reaction of VOCl_3 with Me_3SiOC_6H_3(NO_2)_2-2,4 in toluene and characterised by elemental analyses, molar conductance, and IR, ^1H- and ^{13}C-NMR, and mass spectral studies. The reactions of (I) with alkali metal 2,4-dinitrophenoxides [MOC_6H_3(NO_2)_2-2,4] (M = Li, Na, K) yield complex salts of composition M[VO(OC_6H_3(NO_2)_2-2,4]_4 authenticated by physicochemical and IR spectral studies. Thermal behaviour of complexes was studied by TG and DTA techniques. The molecular modelling calculations of the parent complex and its complex salts were performed to visualise the probable geometry around vanadium metal, which, coupled with spectroscopic evidence, suggests …


Reaction Dynamics Of Br + Hd: Quantum Wave Packet On Three Potential Energy Surfaces, Qing Song, Wei-Long Quan, Tian-Jun Feng Jan 2011

Reaction Dynamics Of Br + Hd: Quantum Wave Packet On Three Potential Energy Surfaces, Qing Song, Wei-Long Quan, Tian-Jun Feng

Turkish Journal of Chemistry

The initial state-resolved reaction probabilities, reaction cross-sections, and rate constants of the reaction Br + HD are computed on 3 potential energy surfaces (denoted as e-LEPS, MB2, and MB3, respectively) by carrying out quantum time-dependent wave packet calculations. The results show that the reactivity of Br + HD on MB3 is much stronger than that on e-LEPS and somewhat weaker than that on MB2. Both of the vibrational and the rotational excitation of reagent HD enhance the reaction, which depends on the PESs and the strongest enhancement effects are on e-LEPS.


Simultaneous Determination Of Trace Sn(Ii) And Sn(Iv) Using Differential Pulse Polarography And Application, Güler Somer, Ülkü Ünal Jan 2011

Simultaneous Determination Of Trace Sn(Ii) And Sn(Iv) Using Differential Pulse Polarography And Application, Güler Somer, Ülkü Ünal

Turkish Journal of Chemistry

A new method was established for the simultaneous determination of Sn(II) and Sn(IV) using differential pulse polarography (DPP). Among several electrolytes, 0.1 M NaOH in the presence of 0.1 M KNO_3 was found to be the most suitable one. In this medium, Sn(II) had 2 peaks, at -0.74 and -1.17 V, which were sharp and very sensitive. Sn(IV), on the other hand, had a very small peak at -0.92 V when its concentration was higher than 4.0 \times 10^{-4} M. Thus, it was decided to determine Sn(IV) after reduction into Sn(II). In the presence of both Sn(II) and Sn(IV), Sn(II) …


Azocalixarenes.7: Synthesis And Study Of The Absorption Properties Of Novel Mono-Azo Substituted Chromogenic Calix[4]Arenes, Hasaletti̇n Deli̇göz, Özlem Özen Karakuş Jan 2011

Azocalixarenes.7: Synthesis And Study Of The Absorption Properties Of Novel Mono-Azo Substituted Chromogenic Calix[4]Arenes, Hasaletti̇n Deli̇göz, Özlem Özen Karakuş

Turkish Journal of Chemistry

Eight new mono-azo substituted chromogenic calix[4]arenes (1-8) were synthesized by diazo-coupling reactions in which 25,26,27-tribenzoyloxy-28-hydroxy-5,11,17-tri-(tert-butyl)calix[4]arene and diazonium salts (2-, 3-, and 4-nitroaniline; 4-phenyl azoaniline; 3- and 4-chloroaniline; or 2- and 4-methylaniline) formed the corresponding mono-azo substituted derivatives in high yields. The mono-azo substituted calix[4]arenes were characterized by UV-Vis, FT-IR, and ^1H-NMR spectroscopic techniques. Elemental analysis was also carried out. In addition, the effects of varying pH levels and solvents upon the absorption ability of azocalix[4]arenes substituted with electron-donating and electron-withdrawing groups at their o-, m-, and p- positions were studied. The results proved that the absorption maxima of the prepared …


Synthesis And Biological Activity Of 5-Substituted-2-Amino-1,3,4-Oxadiazole Derivatives, Sanjeev Kumar Jan 2011

Synthesis And Biological Activity Of 5-Substituted-2-Amino-1,3,4-Oxadiazole Derivatives, Sanjeev Kumar

Turkish Journal of Chemistry

Electrical energy offers numerous benefits for performing synthesis, including increased reaction rates, enhanced yields, and cleaner chemistries. 5-Substituted-2-amino-1,3,4-oxadiazoles were synthesized directly from the semicarbazone at a platinum electrode under controlled potential electrolysis in an undivided cell assembly in acetonitrile. The compounds were screened for antibacterial and antifungal activity against Staphylococcus aureus, Klebsiella pneumoniae, Pellicularia salmonicolor, and Macrophomina phaseolina.


A Study Of Behavior Of Some 5-Substituted- 4-Phenyl-1,2,4-Triazoline-3-Thiones In Sulfuric Acid Solution Using Characteristic Vector Analysis, Vesna Dimova Jan 2011

A Study Of Behavior Of Some 5-Substituted- 4-Phenyl-1,2,4-Triazoline-3-Thiones In Sulfuric Acid Solution Using Characteristic Vector Analysis, Vesna Dimova

Turkish Journal of Chemistry

The protonation process of 1,2,4-triazoline-3-thiones (T3T) was studied in aqueous sulfuric acid using the UV method. Characteristic vector analysis (CVA) was used to reconstruct the experimentally obtained UV spectra, to overcome difficulties in calculating the protonation constants of T3T, and to separate the effect of protonation from the generalized medium effect. pK_{TH}+ values were calculated using the Hammett acidity function method, the Bunnett and Olsen method, and the excess acidity function method. The obtained values for m, \phi and m* were close to those characteristic for similar thio compounds, indicating that the protonation site in the molecule of T3T is …


Synthesis And Evaluation Of The Analgesic Activity Of Some New Isoxazolo[4,5-D]Pyridazin-4(5h)-One Derivatives, Oya Ünsal Tan, Keri̇man Özadali, Özgür Yeşi̇lyurt, Hakan Kayir, İsmai̇l Tayfun Uzbay, Ayla Balkan Jan 2011

Synthesis And Evaluation Of The Analgesic Activity Of Some New Isoxazolo[4,5-D]Pyridazin-4(5h)-One Derivatives, Oya Ünsal Tan, Keri̇man Özadali, Özgür Yeşi̇lyurt, Hakan Kayir, İsmai̇l Tayfun Uzbay, Ayla Balkan

Turkish Journal of Chemistry

Some isoxazolo[4,5-d]pyridazin4(5H)-one derivatives were synthesized and tested for their analgesic activity. The analgesic activities of the compounds were determined by hot-plate and acetic acid writhing tests using morphine and diclofenac as references. Compounds 4a, 4f, 4g, and 4i (25 mg/kg) showed analgesic profiles similar to that of morphine (5 mg/kg).


Synthesis And Antiinflammatory Activity Of Novel 2,5-Disubstituted Thiophene Derivatives, Sahar Badr Jan 2011

Synthesis And Antiinflammatory Activity Of Novel 2,5-Disubstituted Thiophene Derivatives, Sahar Badr

Turkish Journal of Chemistry

New series of 2,5-disubstituted thiophenes were synthesized. Thiosemicarbazones 1a-b were reacted with various reagents, such as diethyl-2-bromomalonate, ethyl-2-chloroacetoacetate, thioglycolic acid, 4-substituted phenacyl bromides, and acetic anhydride, to afford heterocyclic substituted thiophene derivatives 2a-b, 3a-b, 4a-b, 5a-b, 6a-b, and 7a-b, respectively. Moreover, cyclization of the key intermediate 1b with chloroacetic acid yielded thiazolidine 9, which on reaction with appropriate aromatic aldehydes afforded the corresponding arylidene derivatives 10a-f. Finally, reaction of N^\-arylidene cyanoacetohydrazide 11 with sulfur and phenylisothiocyanate yielded thiazoline derivative 12, which on treatment with triethylorthoformate and acetic anhydride afforded thiazolo[4,5-d]pyrimidinone derivative 13. Some of the newly synthesized compounds showed promising …


A Simple And Rapid Spectrophotometric Determination Of Trace Level Simple And Rapid Spectrophotometric Determination Of Trace Level Chromium Using Bis (Salicylaldehyde) Orthophenylenediamine In Nonionic Micellar Media, Rubina Soomro, Jamaluddin Ahmed, Najma Memon Jan 2011

A Simple And Rapid Spectrophotometric Determination Of Trace Level Simple And Rapid Spectrophotometric Determination Of Trace Level Chromium Using Bis (Salicylaldehyde) Orthophenylenediamine In Nonionic Micellar Media, Rubina Soomro, Jamaluddin Ahmed, Najma Memon

Turkish Journal of Chemistry

Bis(salicylaldehyde)orthophenylenediamine (BSOPD) has been proposed as new analytical reagent for the direct spectrophotometric determination of chromium. It reacts with chromium(VI) in slightly acidic (0.1 -- 0.3 M H_2SO_4) micellar medium to form a yellow - orange chelate with a molar ratio 2:3. The most remarkable point of this method is that the molar absorptivities of the Cr^{VI} -- BSOPD complex formed in the presence of nonionic TritonX -- 100 surfactant are almost 10 times higher than the value observed in aqueous solution. This results in enhancing the sensitivity and selectivity of the method. The reaction is instantaneous and the maximum …


Seasonal Ice Mass-Balance Buoys: Adapting Tools To The Changing Arctic, Chris Polashenski, Don Perovich, Jackie Richter-Menge, Bruce Elder Jan 2011

Seasonal Ice Mass-Balance Buoys: Adapting Tools To The Changing Arctic, Chris Polashenski, Don Perovich, Jackie Richter-Menge, Bruce Elder

Dartmouth Scholarship

Monitoring the local mass balance of Arctic sea ice provides opportunities to attribute the observed changes in a particular floe’s mass balance to specific forcing phenomena. A shift from multi- year to seasonal ice in large portions of the Arctic presents a challenge for the existing Lagrangian array of autonomous ice mass-balance buoys, which were designed with a perennial ice cover in mind. This work identifies the anticipated challenges of operation in seasonal ice and presents a new autonomous buoy designed to monitor ice mass balance in the seasonal ice zone. The new design presented incorporates features which allow the …


Arctic Sea-Ice Melt In 2008 And The Role Of Solar Heating, Donald K. Perovich, Jacqueline A. Richter-Menge, Kathleen F. Jones, Bonnie Light Jan 2011

Arctic Sea-Ice Melt In 2008 And The Role Of Solar Heating, Donald K. Perovich, Jacqueline A. Richter-Menge, Kathleen F. Jones, Bonnie Light

Dartmouth Scholarship

There has been a marked decline in the summer extent of Arctic sea ice over the past few decades. Data from autonomous ice mass-balance buoys can enhance our understanding of this decline. These buoys monitor changes in snow deposition and ablation, ice growth, and ice surface and bottom melt. Results from the summer of 2008 showed considerable large-scale spatial variability in the amount of surface and bottom melt. Small amounts of melting were observed north of Greenland, while melting in the southern Beaufort Sea was quite large. Comparison of net solar heat input to the ice and heat required for …


Bismuth-Based Oxide Semiconductors: Mild Synthesis And Practical Applications, Hari Krishna Timmaji Jan 2011

Bismuth-Based Oxide Semiconductors: Mild Synthesis And Practical Applications, Hari Krishna Timmaji

Earth & Environmental Sciences Dissertations

In this dissertation study, bismuth based oxide semiconductors were prepared using 'mild' synthesis techniques - electrodepostion and solution combustion synthesis. Potential environmental remediation and solar energy applications of the prepared oxides were evaluated. Bismuth vanadate (BiVO₄) was prepared by electrodeposition and solution combustion synthesis. A two step electrosynthesis strategy was developed and demonstrated for the first time. In the first step, a Bi film was first electrodeposited on a Pt substrate from an acidic BiCl₃ medium. Then, this film was anodically stripped in a medium containing hydrolyzed vanadium precursor, to generate Bi3+, and subsequent BiVO₄ formation by in situ precipitation. …


A Unit Test Approach For Database Schema Evolution, Katarina Grolinger, Miriam A M Capretz Jan 2011

A Unit Test Approach For Database Schema Evolution, Katarina Grolinger, Miriam A M Capretz

Electrical and Computer Engineering Publications

Context: The constant changes in today’s business requirements demand continuous database revisions. Hence, database structures, not unlike software applications, deteriorate during their lifespan and thus require refactoring in order to achieve a longer life span. Although unit tests support changes to application programs and refactoring, there is currently a lack of testing strategies for database schema evolution.

Objective: This work examines the challenges for database schema evolution and explores the possibility of using various testing strategies to assist with schema evolution. Specifically, the work proposes a novel unit test approach for the application code that accesses databases with the objective …


Some Problems Of Integral Geometry In Advanced Imaging, Rim Gouia Jan 2011

Some Problems Of Integral Geometry In Advanced Imaging, Rim Gouia

Mathematics Dissertations

During the past decade, our society has become dependent on advanced mathematics for many of our daily needs. Mathematics is at the heart of the 21st century technologies and more specifically the emerging imaging technologies from thermoacoustic tomography (TAT) and ultrasound computed tomography (UCT) to non-destructive testing (NDT). All of these applications reconstruct the internal structure of an object from external measurements without damaging the entity under investigation. The basic mathematical idea common to such reconstruction problems is often based upon Radon integral transform.The Radon integral transform Rf puts into correspondence to agiven function f its integrals over certain subsets. …


On The Existence Of Totally Reflexive Modules, Kristen Ann Beck Jan 2011

On The Existence Of Totally Reflexive Modules, Kristen Ann Beck

Mathematics Dissertations

In this manuscript, we investigate the existence of non-free totally reflexive modules over two classes of commutative local (Noetherian) rings.First, we demonstrate existence over a class of local rings which are defined by a Gorenstein homomorphism. Among the corollaries to this result, we recover a theorem of Avramov, Gasharov, and Peeva (1997) concerning the existence of non-free totally reflexive modules over local rings with embedded deformations. We also give a general construction for a class of local rings which satisfy the hypotheses of our theorem, and we show it is able to produce rings without embedded deformations.The second focus of …


High Order Compact Scheme For Discontinuous Differential Equations, James Louis Thompson Jan 2011

High Order Compact Scheme For Discontinuous Differential Equations, James Louis Thompson

Mathematics Dissertations

A high order implicit second derivative compact method is given which is similar the Adams-Moulton method, but requiring only two steps for sixth order. This method is used in both predictor-corrector and Newton's method formulations, and although the compact scheme is not A-stable or stiffly stable, it's region of stability is over six times greater than the Sixth order Adams-Moulton method. This compact method has a small truncation error coefficient, and is more accurate than Enright's method within the region of stability. Fourth and sixth order explicit compact methods are derived as well, and the three step sixth order explicit …


Assessing Measurement Invariance In The Presence Of Testlets, Luis Andres Alvarado Jan 2011

Assessing Measurement Invariance In The Presence Of Testlets, Luis Andres Alvarado

Open Access Theses & Dissertations

Dealing with measurement invariance has been an issue of concern in confirmatory factor analysis for many years. It is important to establish measurement invariance across groups so that instruments may be validly used in multiple groups for comparison of the mean or summative scores. Throughout the years, many studies have considered testing for measurement invariance in factor models. However, there have been no studies that assess measurement invariance when so-called testlets should be modeled in the factor analytic model. Testlets add nuisance covariation to the model which can interfere when trying to detect measurement invariance. In the past, models have …


The Influence Of Pressure Relaxation On The Structure Of An Axial Vortex, Robert L. Ash, Irfan Zardadkhan, Allan J. Zuckerwar Jan 2011

The Influence Of Pressure Relaxation On The Structure Of An Axial Vortex, Robert L. Ash, Irfan Zardadkhan, Allan J. Zuckerwar

Mechanical & Aerospace Engineering Faculty Publications

Governing equations including the effects of pressure relaxation have been utilized to study an incompressible, steady-state viscous axial vortex with specified far-field circulation. When sound generation is attributed to a velocity gradient tensor-pressure gradient product, the modified conservation of momentum equations that result yield an exact solution for a steady, incompressible axial vortex. The vortex velocity profile has been shown to closely approximate experimental vortex measurements in air and water over a wide range of circulation-based Reynolds numbers. The influence of temperature and humidity on the pressure relaxation coefficient in air has been examined using theoretical and empirical approaches, and …


A Cell Electrofusion Microfluidic Device Integrated With 3d Thin-Film Microelectrode Arrays, Ning Hu, Jun Yang, Shizhi Qian, Sang W. Joo, Xiaolin Zheng Jan 2011

A Cell Electrofusion Microfluidic Device Integrated With 3d Thin-Film Microelectrode Arrays, Ning Hu, Jun Yang, Shizhi Qian, Sang W. Joo, Xiaolin Zheng

Mechanical & Aerospace Engineering Faculty Publications

A microfluidic device integrated with 3D thin film microelectrode arrays wrapped around serpentine-shaped microchannel walls has been designed, fabricated and tested for cell electrofusion. Each microelectrode array has 1015 discrete microelectrodes patterned on each side wall, and the adjacent microelectrodes are separated by coplanar dielectric channel wall. The device was tested to electrofuse K562 cells under a relatively low voltage. Under an AC electric field applied between the pair of the microelectrode arrays, cells are paired at the edge of each discrete microelectrode due to the induced positive dielectrophoresis. Subsequently, electric pulse signals are sequentially applied between the microelectrode arrays …


Parametric Study On Instabilities In A Two-Layer Electromagnetohydrodynamic Channel Flow Confined Between Two Parallel Electrodes, P. Dinesh Sankar Reddy, Dipankar Bandyopadhyay, Sang Woo Joo, Ashutosh Sharma, Shizhi Qian Jan 2011

Parametric Study On Instabilities In A Two-Layer Electromagnetohydrodynamic Channel Flow Confined Between Two Parallel Electrodes, P. Dinesh Sankar Reddy, Dipankar Bandyopadhyay, Sang Woo Joo, Ashutosh Sharma, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

Instabilities in a two-phase electromagnetohydrodynamic (EMHD) flow between a pair of parallel electrodes are explored. A linear stability analysis has been performed based on a coupled Orr-Sommerfeld system generated from the conservation laws. The study shows the presence of a finite-wave-number EMHD mode of instability in addition to the two commonly observed instability modes in the pressure-driven two-layer flows, namely, the long-wave interfacial mode arising from the viscosity or density stratification and the finite-wave-number shear flow mode engendered by the Reynolds stresses. This extra EMHD mode originates from the additional stresses generated by the Lorenz force acting at the liquid …


Drag Reduction Of A Modern Straight Truck, Drew Landman, Matthew Cragun, Mike Mccormick, Richard Wood Jan 2011

Drag Reduction Of A Modern Straight Truck, Drew Landman, Matthew Cragun, Mike Mccormick, Richard Wood

Mechanical & Aerospace Engineering Faculty Publications

A wind tunnel test program was conducted at the Langley Full Scale Tunnel (LFST) to evaluate the performance of five passive drag reduction configurations on a modern straight truck at full scale. Configurations were tested in a build-up fashion with results representing a cumulative effect. Tested configurations include a front valance, a front box fairing, a boat-tail, an ideal side-skirt, and a practical side-skirt. Configurations were evaluated over a nominal 9 degree yaw sweep to establish wind averaged drag coefficients using SAE J1252. Genuine replicate yaw sweeps were used in an uncertainty analysis. Results show up to 28% improvement in …