Chemical Engineering Commons^™

Hydrogen Absorption In Weldments Of Overlaid Claded Pressure Vessel, Ronnie Higuchi Rusli

Makara Journal of Technology

Cracks was found in type 347 stainless steel internal attachment welds of a reactor for a high temperature, and high pressure hydrogen service. One of the possible causes of cracking is low cycle fatigue cracking induced by repetition of thermal stress to embrittled weld metal. Type 347 weld metal loses its ductility by presence of sigma phase and hydrogen.

Spectral Response Surfaces And The Ringing Response Of Offshore Structures, I Ketut Suastika

Makara Journal of Technology

A method, called spectral response surface method, is proposed for the study of the ringing phenomenon of offshore structures. Newman’s results for diffraction force on a column were reformulated in terms of the frequency components of the ocean surface and their Hilbert transforms. Using a first-order reliability method together with a dynamic model for the structural response, it is straightforward to calculate the ocean surface history most likely to generate an extreme ringing response and the ringing response history.

Optimum Non Hydrocarbon Gas Injection Development Process And Ultimate Recovery Maximization., Abdulla A.F. Abed

Theses

A multi layered heterogeneous reservoir was selected for this study. The integrated reservoir characterization model and the pertinent transformed reservoir simulation history matched model were quality assured and quality checked.

The development scheme was identified and selected where the pattern and completion of the wells were defined to fit the heterogeneity of the reservoir characterization model. Lateral and maximum block contact holes were investigated.

The development processes studied were mainly hydrogen sulphide, carbon dioxide, nitrogen and rich hydrocarbon gas. The Water Alternating Gas/ Simultaneous Water Alternating Gas (WAG/SWAG) processes were also assured. In addition to the main gas and WAG/SWAG …

Effect Of Operating Pressure On The Extent Of Hysteresis In A Trickle Bed Reactor, Zeljko V. Kuzeljevic, Werner Van Der Merwe, Muthanna H. Al-Dahhan, Milorad P. Dudukovic, Willie Nicol

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Dependence of Hydrodynamic Parameters, Such as Pressure Drop, on the Flow History of the Bed is Called Hysteresis. This Phenomenon is Most Commonly Associated with Changes of Flow Distribution and Flow Patterns with the Flow History. Many Studies Have Shown that Increased Operating Pressure Will Affect Flow Distribution and Wetting Efficiency; However, There Seems to Be No Study of the Effect of the Elevated Operating Pressure on the Extent of Hysteresis. in This Study, an Experimental Investigation of the Hysteresis in a High-Pressure Trickle Bed Has Been Performed. a Hysteresis Factor Has Been Introduced to Quantify the Extent of …

Ala Spotlight Series V.2, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

No abstract provided.

Effect Of Intermittent Applications Of Continuous Ultrasound Signal On The Morphology And Cytoskeletal Organization In Chondrocytes, Anuradha Subramanian, Sandra Noriega, Gulnara Hasanova

Anuradha Subramanian Publications

The cellular component of the articular cartilage, chondrocytes, have long been recognized as strain-sensitive cells, and have the ability to sense mechanical stimulation through surface receptors and intracellular signaling pathways. In the present study, a continuous ultrasound wave for predetermined time intervals was employed, as opposed to pulsed-ultrasound used in previous studies, to stimulate chondrocytes seeded in 3D scaffolds. Chondrocytes seeded in 3D scaffolds (n = 6) were subjected to stimulation by US as follows: 1.5 MHz for 161 s, 5.0 MHz for 51 s and 8.5 MHz for 24 s and the US signal was applied twice in a …

Control On Platelet Adhesion And Activation Events By Selective And Specific Binding Of Plasma Protein On Peptide-Coupled Surface, Anuradha Subramanian, Sanjukta Guha-Thankruta

Anuradha Subramanian Publications

Implantable material surfaces suffer from unavoidable major events of blood–biomaterial interactions leading to thrombus formation and finally foreign material rejection. An albuminated surface can minimize the platelet adhesion and activation that reduces the chance of thrombus formation. The main objective of our work was to design surfaces having maximum human serum albumin (HSA) binding capacity over other plasma proteins in blood by covalently grafting custom made peptides having selectivity and specificity towards HSA. First, silicon wafer surfaces were chemically treated to generate –NH2 terminated self-assembled monolayer (SAM). SAMs were then covalently coupled with (a) peptides using 1- ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride and …

Importance Of Annealing Times In The Pcr Amplification Of Gc-Rich Genes, Anuradha Subramanian, Tarlan Mamedov, Elsje Pinnear, Hendrik J. Viljoen

Anuradha Subramanian Publications

This combined theoretical and experimental study conclusively demonstrates that annealing times play a crucial role in the PCR amplification of GC-rich templates. To assist with the DNA amplification of GC-rich targets, a theory has been developed that evaluates the fraction of annealed primer/polymerase complex at the correct binding site as a function of annealing temperature and annealing period. Optimum annealing times lie in the range of 3 to 6 s, and annealing times greater than 10 s yield smeared PCR amplified products. The theory has been applied to the PCR amplification of the following human cDNA templates: ARX gene (78.2%, …

Link Foundation Fellowship Report, Elisabeth A. Gilmore

Link Foundation Energy Fellowship Reports

Peak hour electricity demand is associated with wholesale electricity prices that are sometimes more than 10 times higher than in off-peak periods. During these high-demand periods congested transmission lines and insufficient generation capacity can lead to brownouts and blackouts. This problem can be especially acute in urban centers. One way to alleviate this problem is to build new peaking plants. We investigated the costs and benefits, including expenditures and adverse health effects, of using existing backup generators and battery based electrical storage facilities to meet peak load demands rather than investing in a new power plant. Using small-scale generation located …

Mechanistic Investigation Of Ash Deposition In Pulverized-Coal And Biomass Combustion, Shrinivas Sadashiv Lokare

Theses and Dissertations

This investigation details the effects of fuel constituents on ash deposition through systematic experimental and theoretical analyses of fundamental particle experiments and a suite of fuels with widely varying inorganic contents and compositions. The experiments were carried out in the Multifuel Flow Reactor (MFR) at Brigham Young University. Fuels included several biomass fuels (straw, sawdust and mixtures of straw-sawdust with other additives such as Al(OH)3, CaCO3, etc.) and four commercially-used coals (Illinois#6, Powder River Basin – Caballo and Cordero, Blind Canyon, and Lignite – Beulah Zap). The data from the series of experiments quantitatively illustrate the effects of fuel properties, …

A-Priori Analysis Of Conditional Moment Closure Modeling Of A Temporal Ethylene Jet Flame With Soot Formation Using Direct Numerical Simulation, David O. Lignell, John C. Hewson, Jacqueline H. Chen

Faculty Publications

Modeling soot formation in turbulent nonpremixed combustion is a difficult problem. Unlike most gaseous combustion species, soot lacks a strong state relationship with the mixture fraction due to unsteady formation rates which overlap transport timescales, and strong differential diffusion between gaseous species and soot. The conditional moment closure model (CMC) has recently been applied to the problem of turbulent soot formation. A challenge in CMC modeling is the treatment of differential diffusion. Three-dimensional direct numerical simulation (DNS) of a nonpremixed ethylene jet flame with soot formation has been performed using a 19 species reduced ethylene mechanism and a four-step, three-moment, …

Enhancing Water Removal From Whole Stillage By Enzyme Addition During Fermentation, Ana Beatriz Henriques, David B. Johnston, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Removal of Water from Coproducts in the Fuel Ethanol Process Requires a Significant Energy Input. in This Study, the Addition of Commercially Available Cell-Wall-Degrading Enzymes Was Investigated to Determine Whether or Not the Enzymes Could Reduce the Amount of Water Bound within the Wet Grains. This Would Have the Effect of Allowing More Water to Be Removed during Centrifugation, Reducing the Time and Energy Needed during the Drying Process. the Experiment Screened 15 Cell-Wall-Degrading Enzyme Preparations. a Significant Reduction in Water-Binding Capacity Was Found for a Number of Enzymes Tested in the Initial Screening. the Experiment Was Repeated and …

Novel Polypropylene Based Microporous Membranes Via Spherulitic Deformation, Kuan-Yin Lin

Dissertations

A novel method for creating a microporous polypropylene membrane via spherulitic deformation is described. The microporous structure was generated by the combination of intra-spherulitic and inter-spherulitic deformations. Polypropylene was selected due to its unique cross-hatched lamellar morphology facilitating inter-spherulitic deformation. A precursor film with a spherulitic structure was made under low-stress melt processing condition. A tangential lamellae-rich spherulite was created and identified with a positive birefringence sign. A sequential annealing process improved the crystalline structure, and in particular the thickness of the tangential lamellae. The annealing process proved to be critical for initiating the inter-spherulitic deformation. The post-extrusion process conditions …

Degradation Of Polylactic Acid In The Presence Of Microsize And Nanosize Fillers, Quyuan Zhou

Dissertations

Polylactide (PLA)-cationic (montmorillonite, MMT) and anionic (hydrotalcite, HT) clay micro- or nanocomposites based on semicrystalline and amorphous polymers and unmodified and organomodified as well as calcined or non-calcined clays at 5wt% concentration are produced by melt mixing. Depending on the clay type, presence of organomodifiers and calcination, micro- or nanocomposites are produced, as confirmed by XRD and SEM analysis.

Unfilled polymers and their composites are subjected to isothermal degradation in air at 180°C and 200°C. Degradation rate constants are calculated from novel equations incorporating IV. Results show that the thermal degradation rate constants of the amorphous PLA and its composites …

Experimental Investigation Of The Effect Of Sonication On The Precipitation Of Grieseofluvin By Impinging Jets, Ankit H. Patel

Theses

Almost 80% of drugs on the market are manufactured as solid dosage forms, such as tablets. Drug bioavailability increases as the particle size decreases and the surface area per unit volume of drug increases. Therefore, there is a keen interest by the pharmaceutical industry to develop techniques that can be used to manufacture particles of active pharmaceutical ingredients (API) in the nano/micro particle range. Impinging jets is one of the most promising techniques to do so.

In this work, a submerged impinging jet system coupled with an ultrasonic probe (sonicator) was used to precipitate Griseofulvin, a common, poorly water-soluble antifungal …

Precipitation Of Ultrafine Particles Using Liquid Antisolvent With Concentric Ultrasonic Nozzle And Subcritical Co2, Satya Chaitanya Kunchala

Theses

Nanotechnology has become more relevant in the pharmaceutical industry. Almost 40% of the drugs developed by pharmaceutical industries are poorly soluble in water which limits the bioavailability of these drugs in body fluids. Hence, it is necessary to reduce the particle size, which increases the interfacial surface area. This work focuses on micronization of class ii drug Griseofulvin which is poorly water soluble. Two processes namely, liquid antisolvent precipitation using ultrasonic nozzle and other process using subcritical CO₂ have been used to produce ultrafine particles of this drug.

In liquid antisolvent precipitation, a combination of ultrasound, polymer and surfactant …

Electrocatalytic Oxidation Of Salicylic Acid At Novel Gold Nanoparticle-Modified Glassy Carbon Electrode, Yan-Ping Cui, Chang-Zhu Yang, Jian Huang, Wen-Hong Pu, Jing-Dong Zhang

Journal of Electrochemistry

A gold nano-particles modified glassy carbon electrode(GNP/GCE) was prepared by the"seed-mediated gold nano-particles growth method".Field emission scanning electron microscopy,ultraviolet-visible(UV-vis) spectroscopy analysis and electroalaylsis were employed to study the morphology and electrochemical performances.The resulting electrode showed excellent electro-catalytic activity toward the oxidation of salicylic acid and the response sensitivity was 1.8 fold than that obtained on GCE.Good linear relationship was obtained between response current and salicylic acid concentration in the range of 5.0 × 10^-7 ~8.0 × 10^-5 mol/L,which could be used in the detection of trace salicylic acid.

The Effect Of Ru: Sn On Properties Of Ru-Ir-Sn Oxide Anode Coatings, Lei Ji, Jun-Tao Wang, Wen-Bin Liu, Li-Kun Xu, Gui-Lin Xue

Journal of Electrochemistry

The anode coatings of Ru-Ir-Sn oxide with different Ru/Sn ratios were prepared by sol-gel method.The influences of Ru/Sn ratio on properties of anode coatings were studied by scanning electron microscope(SEM),energy dispersive X-ray detector(EDX),X-ray diffraction(XRD).The potential of chlorine evolution,current efficiency,accelerated life,cyclic vohammetry and electrochemical impedance spectroscopy(EIS) tests were carried out.The results showed that there was an obvious effect of Ru/Sn ratio on the morphology of the coatings.The cyclic voltammogram,double layer capacitances and accelerated life of anode coatings had a tendency to fall down firstly then increased as the Ru% increased,the current effency and potential of chlorine evolution had a tendency to …

Design And Fabrication Of The High Efficient Platinum-Nanoporous Gold Catalysts, Zhao-Na Liu, Jin-Tao Zhang, Fang Tian, Peng-Peng Liu, Hou-Yi Ma, Yi Ding

Journal of Electrochemistry

The nanoporous gold(NPG) electrodes with uniform pore sizes and ligaments were prepared by using a simple dealloying method.The as-prepared NPG showed high catalytic activity towards the oxidation of formic acid and formaldehyde.After tiny amount of platinum was deposited onto the NPG substrate,not only the structure stability of NPG was greatly improved,but also the Pt-Au bimetallic catalysts displayed the better catalytic activity and the stronger poison resistance towards the electrooxidation of small organic molecules than the bulk platinum due to synergistic effect between Au and Pt compositions.

A Study Of Pd-Ir On Nickel Foam Cathode For Aluminum-Hydrogen Peroxide Semi-Fuel Cells, Ding-Wang Zhu, Dan-Dan Chen, Bi-Jin Li, Gui-Ling Wang, Dian-Xue Cao

Journal of Electrochemistry

The Pd-Ir/Ni electrodes were prepared by electrodeposition of Pd and Ir on the porous nickel foam surface.The structure,composition and state of the Pd-Ir catalyst were analyzed using SEM and XPS.The catalytic performance of Pd-Ir/Ni for H₂O₂ electroveduction at different concentrations of H₂O₂ were investigated.A limiting current density of 318 mA/cm² was obtained with 0.4 mol/L H₂O₂.The aluminum-hydrogen peroxide semi-fuel cells using different aluminum alloys as anode and Pd-Ir/Ni as cathode were assembled and tested.It was found that the fuel cell with aluminum-manganese alloy anode demonstrated a maximum power density …

Electrochemical Synthesis, Characterization And Fluorescence Property Of Nano Na2Sif6, Guo-Xu Qin, Xin-Jun Wan, Xi-Mei Yuan, Dao-Bao Chu

Journal of Electrochemistry

The nano TiO₂ film was prepared by sol-gel process and characterized with X-ray diffraction(XRD) and scanning electron microscope(SEM).It was found that the average size of pore diameter was about 80 nm for the nano TiO₂ film.The Nano Na₂SiF₆ was synthesized by electrochemical deposition on the nanoporous film electrode and characterized with XRD and transmission electron microscope(TEM).The result showed that the average size of nanoparticle was 20 nm for the nano Na₂SiF₆.The fluorescence property of nano Na₂SiF₆ was also studied briefly.The result indicated that the nano Na₂SiF …

Electricity Generation In Microbial Fuel Cells Catalyzed By Mixed Culture And Pure Culture, Chen-Dong Shuang, En-Ren Zhang, Guo-Wang Diao, Fang-Fang Fan, Jie Yuan

Journal of Electrochemistry

Microbial fuel cells(MFCs) were constructed by inoculating fresh sedimentary microorganisms.Effect of phenol on performance of MFCs was investigated.The results showed that the generation of electrical current was induced by bacteria attached on the surface of the anode.Presence of phenol reduced the rate of glucose consumption and extended the duration of electricity generation with the same addition of glucose.In addition,the electricity generation by a single strain(belonging to pseudomonas species) separated from the sedimentary MFC was also investigated.The experimental results indicated that the presence of metabolic intermediates which exhibited electrochemical activity was necessary for the electricity production.Analysis of GC-MS showed that the …

Electrocatalytic Performance Of Carbon Supported Au-Ir Catalyst As Cathodic Catalyst In Direct Formic Acid Fuel Cell, Wei Chen, Ya-Wen Tang, Tain-Hong Lu

Journal of Electrochemistry

In this paper,it is reported for the first time that the electrocatalytic activities of the carbon supported Au(Au/C),carbon supported Ir(Ir/C) and the carbon supported Au-Ir(Au-Ir/C) catalysts prepared in the aqueous solution with tetrahydrofuran(THF) for the oxidation of formic acid and for the oxygen reduction were compared.It was found that all three catalysts showed no electrocatalytic activity for the oxidation of formic acid,but the electrocatalytic activity of the Au-Ir/C catalyst for oxygen reduction was much better than those of Au/C and Ir/C.Thus,the Au-Ir/C catalyst is suitable to be used as the cathodic catalyst in Direct formic acid fuel cell(DFAFC).

Hydrolysis Of Sodium Borohydride By Ru-Ni Foam Catalyst, Jie Cheng, Feng Ye, Tong-Tao Wang, Jing-Jing Li, Yong-Liang Wang, Xin-Dong Wang

Journal of Electrochemistry

This paper presented a method of hydrogen generation from sodium borohydride solution for fuel cells.The Ru-Ni foam catalyst which was prepared by chemical plating showed strong activity and stability.The pretreatment of Ni foam before chemical plating was very important for the catalyst's strong activity and stability.This easy-to-prepared catalyst exhibited a good activity after being used several times.The effects of NaBH₄ concentration,temperature and used times on the hydrogen generation rate were investigated.The results showed that the rate was remarkablely increased with the temperature rising and the rate increased more than ten times when the temperature of reaction rised from 15 …

Study On Electrocatalytic Oxidation Of Salbutamol At Carbon Nanotubes Modified Electrode, Ying-Liang Wei, Lu-Ping Zhang, Chen Shao, Hui Feng, Xian-Li Li

Journal of Electrochemistry

The multi-wall carbon nanotubes(MWNT) were dispersed successfully into water in the presence of dihexadecyl hydrogen phosphate(DHP) and a stable well-distributed suspension.A was formed sensor based on the multi-carbon nanotubes film coated glassy carbon electrode was developed.The electrochemical response of salbutamol was studied by square wave voltammetry.The oxidation peak potential of salbutamol at the modified electrode was observed at 0.604 V,which shifted about 40 mV negatively.The peak current increased 4.5 folds,in contrast to that at a bare electrode.Under optimal measurement conditions,there was a good linear relationship between the peak current(Ipa) and salbutamol concentration(C) in the range from 8.3 × 1 0 …

Thermally Activated Switching In The Presence Of Non-Gaussian Noise, Lora Billings, Mark Dykman, Ira Schwartz

Department of Mathematics Faculty Scholarship and Creative Works

We study the effect of a non-Gaussian noise on interstate switching activated primarily by Gaussian noise. Even weak non-Gaussian noise can strongly change the switching rate. The effect is determined by all moments of the noise distribution. It is expressed in a closed form in terms of the noise characteristic functional. The analytical results are compared with the results of simulations for an overdamped system driven by white Gaussian noise and a Poisson noise. Switching induced by a purely Poisson noise is also discussed.

Kinetics Of Preferential Adsorption And Equilibrium Properties Of Interfacial Layers Formed From Polymer Chains That Tether By Multiple Ends, Jose Alonzo Calderon

All Dissertations

Due to their ability to straddle phase boundaries, polymer brushes represent a model system for studies of polymer-modified surfaces. The research presented in this dissertation focuses on understanding a special type of polymer brushes formed at the solid-fluid interface by self-assembly of block copolymer chains that have the ability to tether by multiple ends, thus creating loops on the surface. Specifically, I study the self-assembly of a series of poly(2-vinylpyridine)-polystyrene-poly(2-vinylpyridine) (PVP-b-PS-b-PVP) triblock copolymers and PVP-b-PS star block copolymers adsorbed from the selective solvent toluene onto silicon and mica surfaces. The triblock and star copolymers have different molecular weights and PS/PVP …

Partial Crystallinity In Alkyl Side Chain Polymers Dictates Surface Freezing, Shishir Prasad, Zhang Jiang, Sunil K. Sinha, Ali Dhinojwala

College of Polymer Science and Polymer Engineering

We have studied the structure of a novel crystalline surface monolayer on top of a disordered melt of the same material [poly(n-alkyl acrylate)s] using grazing incidence x-ray diffraction. The grazing incidence x-ray diffraction, surface tension, and bulk latent heat results show that side chains crystallize except the nine methylene units of the alkyl side chains closest to the polymer backbone. The partial crystallinity along with a thicker surface layer, due to the additional length of the linker group, explains why the difference between the surface order-to-disorder transition temperature and bulk melting temperature increases with a decrease in the length of …

Steady State Measurements In Stress Plateau Region Of Entangled Polymer Solutions: Controlled-Rate And Controlled-Stress Modes, Sham Ravindranath, Shi-Qing Wang

College of Polymer Science and Polymer Engineering

Despite decades of efforts, reliable measurements of nonlinear flow behavior of well-entangled polymers in continuous shear have been challenging to obtain. The present work attempts to accomplish three important tasks: (A) overcome this challenge by adopting a strategy of decoupling theological measurements from the outer meniscus region in a cone-partitioned plate (C/PP) setup; (B) determine whether well-entangled solutions indeed undergo a flow transformation under creep that can be taken to phenomenologically define an entanglement-disentanglement transition (EDT); (C) provide the velocity profiles of such solutions undergoing either controlled-stress or controlled-rate shear by carrying out in situ particle-tracking velocimetric (PTV) measurements. Upon …

Labevolution: What's The Next Mutation?, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

No abstract provided.