Chemical Engineering Commons^™

Observation Of Photovoltaic Effect And Single-Photon Detection In Nanowire Silicon Pn-Junction, Arief Udhiarto, Sri Purwiyanti, Daniel Moraru, Takeshi Mizuno, Michiharu Tabe

Makara Journal of Technology

We study nanowire silicon pin and pn-junctions at room and low temperature. Photovoltaic effects are observed for both devices at room temperature. At low temperature, nanowire pn-junction devices show their ability to detect single photon. This ability was not been observed for pin devices. Phosphorus-boron dopant cluster in the depletion region is considered to have the main role for single-photon detection capability. Fundamental mechanism of dopant-based single-photon detection in nanowire pn-junction is described in details.

Improvement In Performance Of Zno Based Dsc Prepared By Spraying Method, Rangga Winantyo, Devinda Liyanage, Kenji Murakami

Makara Journal of Technology

This paper reports the effect of TiCl4 on the performance of ZnO based DSC. ZnO was used due to its stability against photo-corrosion and photochemical properties similar to TiO2. Thin films of nanocrystalline ZnO were deposited on transparent conducting oxide glass using spray method. The ZnO films were treated using TiCl4. The cell’s efficiency was found to be 2.5% with TiCl4 post-treatment and 1.9% without TiCl4 post-treatment.

Influences Of Surface Morphology Of Nanostructured Rutile Tio2 Nanorods/Nanoflowers As Photoelectrode On The Performance Of Dye-Sensitized Solar Cell, Mohd Khairul Bin Ahmad, Kenji Murakami

Makara Journal of Technology

Aligned Rutile TiO2 nanorods (r-TNRs) and TiO2 nanoflowers (r-TNFs) were successfully prepared by hydrothermal method. Using hydrochloric acid (HCl) as chelating agent and titanium butoxide (TBOT) as precursor, aligned r-TNRs with r-TNFs were successfully growth onto fluorine-doped tin oxide (FTO) with different morphologies. The influences of surface morphologies to the rutile based Dye-sensitized solar cell (DSC) efficiency are discussed. The highest lightto- electric energy conversion efficiency, 1.80% is achieved using different concentration under simulated solar light illumination of 100 mWcm-2 (1.5 AM).

Fatigue Life Prediction Of The Keel Structure Of A Tsunami Buoy Using Spectral Fatigue Analysis Method, Angga Yustiawan, Ketut Suastika, Wibowo Harso Nugroho

Makara Journal of Technology

One of the components of the Indonesia Tsunami Early Warning System (InaTEWS) is a surface buoy. The surface buoy is exposed to dynamic and random loadings while operating at sea, particularly due to waves. Because of the cyclic nature of the wave load, this may result in a fatigue damage of the keel structure, which connects the mooring line with the buoy hull. The operating location of the buoy is off the Java South Coast at the coordinate (10.3998 S, 108.3417 E). To determine the stress transfer function, model tests were performed, measuring the buoy motions and the stress at …

Production Optimization For Plan Of Gas Field Development Using Marginal Cost Analysis, Suprapto Soemardan, Widodo Wahyu Purwanto, Arsegianto Arsegianto

Makara Journal of Technology

Gas production rate is one of the most important variables affecting the feasibility plan of gas field development. It take into account reservoir characteristics, gas reserves, number of wells, production facilities, government take and market conditions. In this research, a mathematical model of gas production optimization has been developed using marginal cost analysis in determining the optimum gas production rate for economic profit, by employing the case study of Matindok Field. The results show that the optimum gas production rate is mainly affected by gas price duration and time of gas delivery. When the price of gas increases, the optimum …

Characterization Of Samples For Optimization Of Infrared Stray Light Coatings, Carey L. Baxter, Rebecca Salvemini, Zaheer A. Ali, Patrick Waddell, Greg Perryman, Bob Thompson

STAR Program Research Presentations

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) is a converted 747SP that houses a 2.5 m telescope that observes the sky through an opening in the side of the aircraft. Because it flies at altitudes up to 45,000 feet, SOFIA gets 99.99% transmission in the infrared. Multiple science instruments mount one at a time on the telescope to interpret infrared and visible light from target sources. Ball Infrared Black (BIRB) currently coats everything that the optics sees inside the telescope assembly (TA) cavity in order to eliminate noise from the glow of background sky, aircraft exhaust, and other sources. A …

Extending The Shelf Life Of Solid Rocket Motors Through Mechanical Activation Of, Emilio J. Cantu, Hope Klukovich, Timothy Haddad

STAR Program Research Presentations

A great deal of interest has been given to extending the life of our fleet of solid rocket motors. Once poured, these motors are essentially stored, unused, and are therefore subject to various environmental conditions. Cycling between high and low temperatures causes thermal expansion and contraction of motor materials. This will eventually lead to cracks forming and propagating in the rocket motor, rendering it unreliable and thus must be re-poured at great expense. A common binder material used in these motors is hydroxy-terminated polybutadiene (HTPB), which when cured with a diisocyanate, creates the solid matrix to house the energetic materials …

Sustainable Operations For Distillation Columns, Yaşar Demirel

Yaşar Demirel Publications

Distillation process consumes about 40% of the total energy used to operate the plants in petrochemical and chemical process industries in North America. Therefore, sustainable distillation column operation requires responsible use of energy and reduction of harmful emission such as CO₂. The Aspen Plus ‘Column Targeting Tool’ (CTT) options in a simulation environment can help reduce the use of energy and hence CO₂ emission. The Aspen plus ‘Carbon Tracking’ (CT) together with the ‘Global Warming Potential’ options can quantify the reduction in CO₂ emission. The CTT is based on the practical near-minimum thermodynamic condition approximation and …

Improved Deinkability Of Lep (Liquid Electrophotography) Digital Prints, Zheng Wei

Masters Theses

Digital printing plays a very important role in the life of modern society. With the development of digital printing technologies, and the increasing market share of digital printing, the amount of digital prints in waste paper is rapidly increasing. Under “green” manufacturing and environmental sustainability, deinking of digital print inks is an urgent problem that needs to be solved. Indigo is a typical series of HP (Hewlett-Packard) digital presses that use a liquid ink named ElectroInk (Liquid Electrophotography or LEP). The particle size of HP ElectroInk is very small, 1-2 microns, which is smaller than dry toners. But, during flotation, …

Controlling Bacterial Persister Cells And Biofilms By Synthetic Brominated Furanones, Jiachuan Pan

Biomedical and Chemical Engineering - Dissertations

Bacteria are well known to obtain tolerance to antibiotics by forming multicellular structures, known as biofilms, and by entering dormancy and forming persister cells. Both mechanisms allow bacteria to tolerate antibiotics at concentrations hundreds to thousands of times higher than the lethal dose for regular planktonic cells of the same genotype. Persister formation increases in biofilms; thus, effective control of persister cells, especially those in biofilms is critically important to infection control. Over the past decades, a bacterial signaling system based on cell density, named quorum sensing (QS), has been found to regulate biofilm formation and, in Pseudomonas aeruginosa, the …

New Approaches On Deinking Evaluations, Roland Gong

Dissertations

Paper recycling in the U.S. is the most successful program of environmental sustainability. Approximately two thirds of consumed paper products were recycled, according to the EPA and AF&PA. However, domestic mills only applied one third of recycled fibers into new products, which is much lower than reported in China (67%). The domestic recycle mills claimed that outdated facilities, poor recycled fiber quality and high manufacturing cost are the major issues. They also said that these recycle mills have been put in a “no-win” position, which threatens the whole recycling loop eventually. A case study about Chinese recycle mills has been …

An Intrinsic Model For Graphite Oxidation And The Effects Of Microstructural Features On Apparent Rate, Joshua J. Kane

Boise State University Theses and Dissertations

The very high temperature reactor (VHTR) is the latest generation of high-temperature gas-cooled reactors (HTGR). The VHTR has higher outlet temperatures than a traditional HTGR with outlet temperatures up to 1000 °C. This high outlet temperature permits emissions-free process heat in the form of high-quality steam for high temperature industrial applications. Moreover, the high temperatures of the reactor could potentially be used for hydrogen production from water or high efficiency electrical power production (~50% efficiency of thermal to electrical power conversion).

The VHTR is designed to employ helium as its coolant and uses graphite for its neutron moderator and as …

A Localized Controlled Delivery System Utilizing A Block Copolymer To Improve The Current Paradigm Of Chemotherapy, Jason Olbrich

All Dissertations

The goal of the field of Bioengineering has always been to bring about a better standard of care for patients. As a field encompassing a broad array of researchers and talents, such improvements often are brought about through the integration of different fields. This work advances the integration of controlled delivery and chemotherapy. The use of cytotoxic chemotherapy has become and will continue to be a powerful tool for the treatment of solid malignancies. Conventional dose scheduling of cytotoxic agents and newer biological response modifiers are investigated under a clinical paradigm initially designed to identify a drug dose that elicits …

Perfluorocyclobutyl Polymer Thin-Film Composite Membrane Fabrication, Plasticization And Physical Aging, Jinxiang Zhou

All Dissertations

Membrane technologies have been used widely in industrial practices such as waste water treatment, sea water desalination, gas separations, pharmaceutical separations, and food and beverage processing to name a few. Among the features that make them attractive are that they are cost effective, highly efficient, scalable, and environmentally benign. The focus of this dissertation is to contribute to the understanding and use of polymeric membranes for carbon dioxide separations.
Currently, the largest carbon capture demand lies in the natural gas industry. However, since global warming has become a severe concern for human existence, flue gas cleaning is potentially another very …

A Computational Approach For The Rational Design Of Bimetallic Clusters For Ethanol Formation From Syn-Gas, Ming He

All Dissertations

There is currently a growing interest in the catalytic synthesis of ethanol from syn-gas (2CO + 4H2 --> C2H5OH + H2O). A major challenge associated with this direct route is an inability to find a low-cost catalyst that promotes the proper combination of CO dissociation and CO insertion steps, so as to yield ethanol as the primary reaction product. Bimetallic catalysts, in which one metal promotes hydrocarbon production and the other oxygenate production, may exhibit a synergistic effect that can facilitate the formation of ethanol. Given the complexity of this reaction system, a simple trial-and-error approach to catalyst design is …

Advanced Biomaterials From Renewable Resources: An Investigation On Cellulose Nanocrystal Composites And Co2 Extraction Of Rendered Materials, Jose Orellana

All Dissertations

The annual global consumption of petroleum-based plastics is approximately 280 million tons and is impacting the sustainability of our planet and prosperity of future generations. One solution is the development of bio-based polymer materials with advanced properties for commercial applications. Therefore, the ultimate goal of this dissertation is to investigate the properties of new bio-based materials for broader applications. This dissertation includes two research areas: cellulose nanocomposites, and CO₂ extractions of rendered fat. In the first half, cellulose nanocrystals (CNCs), which exhibit excellent mechanical and optical properties, were investigated for the reinforcement of a biodegradable polymer. The properties of …

Novel Ceria-Zirconia-Yttria Mesostructures: Synthesis, Characterization, Diffusional Studies And The Effects Of Morphology On Their Properties, Alma Cordova Morales

All Dissertations

Ceria-zirconia-yttria (CZY) mixed oxides are used as catalyst supports for three-way catalysts for automotive exhaust emission control and in solid oxide fuel cells. By improving the morphology of CZY mesopores it is possible to reduce the sintering of supported noble metals and enhance overall catalyst lifetime and performance. However, limited studies have been published on the synthetic control of the morphology of CZY materials and the effects that CZY pore geometry has on catalyst operation.
To create optimized CZY catalyst supports, novel mesoporous CZY oxides were synthesized via classical sol-gel and evaporation induced self-assembly (EISA) methods, obtaining mesostructures that exhibited …

Algae To Propellants: Biosynthesis Of 1,2-Propanediol From Algal Derived Sugars, Lauren Rachelle Merriman

Graduate Theses and Dissertations

Propylene glycol dinitrate (PGDN) is an important component used in the formulation of energetic materials. A renewable, environmentally-friendly and effective production technique for the production of 1,2-propanediol, an important precursor to PGDN, is desired. While fermentation of 1,2-propanediol has been achieved, it suffers from major limitations such as expensive feed sugars and relatively low yields. It is hypothesized that algae sugars could serve as a feedstock for the microbial synthesis of 1,2-propanediol, thereby reducing production costs and enhancing sustainability.

Algal biomass produced from an Algal Turf Scrubber® has proven to have significant potential as a source of fermentable materials. However, …

Aspen Plus Simulation Of Biomass Gasification In A Steam Blown Dual Fluidised Bed, Wayne Doherty, Anthony Reynolds, David Kennedy

Book/Book Chapters

The efficient utilisation of biomass resources is of utmost importance. Biomass gasification offers much higher efficiencies than combustion. Gasification is a process in which a fuel is converted to a combustible gas (syngas). A dual fluidised bed gasifier known as the fast internally circulating fluidised bed (FICFB) was selected. It has been demonstrated at industrial scale and data is readily available for model validation. An Aspen Plus model was developed to simulate the FICFB gasifier. The model is based on Gibbs free energy minimisation and the restricted equilibrium method was used to calibrate it. The model has been validated and …

Erratum: A Mechanistic Model Of Early Fcεri Signaling: Lipid Rafts And The Question Of Protection From Dephosphorylation (Plos One (2013) 8 (8)), Dipak Barua, Byron Goldstein

Chemical and Biochemical Engineering Faculty Research & Creative Works

A funding organization and grant were incorrectly omitted from the Funding Statement. The Funding Statement should read: "Research reported in this publication was supported by the National Institute of General Medical Sciences of the National Institutes of Health under award number R37-GM035556, The SpatioTemporal Modeling Center at the University of New Mexico under award number P50:GM065794 and the Department of Energy through contract DE-AC52-06NA25396. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript."

Characterization And Quantification Of Monomers, Oligomers, And By-Products From Switchgrass Hemicelluloses During Biomass Pretreatment, Kris Allan Bunnell

Graduate Theses and Dissertations

Production of fuels and chemicals from biomass is contingent upon economical release of carbohydrates from biomass. Carbohydrates can then be used for production of bio-based products using a biochemical conversion process. Pretreatment, the first step of the biochemical conversion process, has been suggested to be the most costly step of the conversion process. Thus, better understanding the behavior of biomass during pretreatment is imperative for an economically viable production of biofuels and chemicals. Elucidating the physicochemical properties of biomass and developing an understanding the depolymerization patterns of biomass during pretreatment will help progress towards this goal.

In this study, July- …

Development Of Surface Based Platforms For Biomolecular Recognition And Protease Assays, Jose Cornejo

Chemical and Biological Engineering ETDs

The discovery of analytical tools for biomolecular recognition in the area of diagnostics is a research trend rich in innovative methods. Some of the main drivers found in this area are the constant need for low cost devices and biosensors, simplicity in design and operation, and time efficiency. In this thesis we present novel approaches for the development of protease activity assays. Our focus of study is the protease assay development process on two types of characterized platforms: microspheres and self-assembled monolayers (SAMs) on flat surfaces. The surface preparation and conjugation process with biological components of interest is presented along …

Experimental Characterization And Modeling Of Aspect-Rario-Dependent Diffusion Of Nanocrystals In Nanochannels, Louis Tribby

Chemical and Biological Engineering ETDs

The investigation of aspect-ratio-dependent diffusion and equilibrium partitioning of semiconductor nanocrystals in rectangular nanochannels has been undertaken. The nanocrystals are terminated with hydrocarbon ligands and suspended in toluene, considered an aprotic solvent. Time-dependent concentration profiles are measured as a function of distance from the channel entrance by the calibrated fluorescence intensity of the nanocrystals. Both the forward diffusion of the nanocrystals and their reverse diffusion are characterized. Nanocrystals are first allowed to diffuse forward from a reservoir into the nanochannels over a long period (\u2265 3 days) until the inlet concentration reaches a steady state. Subsequently, these nanocrystals are allowed …

Cryogenic Carbon Capture Using A Desublimating Spray Tower, Bradley J. Nielson

Theses and Dissertations

Global warming is becoming ever increasing concern in our society. As such the likelihood of a carbon tax in the US is becoming increasingly likely. A carbon tax will be expensive enough that coal-based power plants will either have to install carbon capture technology or close. The two front runner technologies for carbon capture are amine scrubbing, and oxyfuel combustion. The downside is that both of these technologies increase power generation cost in a new plant by about 80% and have up to a 30% parasitic load, which reduces the cycle efficiency, that is, the power production per unit fuel …

Aqueous Henry's Law Constants, Infinite Dilution Activity Coefficients, And Water Solubility: Critically Evaluated Database, Experimental Analysis, And Prediction Methods, Sarah Ann Brockbank

Theses and Dissertations

A database containing Henry's law constants, infinite dilution activity coefficients and solubility data of industrially important chemicals in aqueous systems has been compiled. These properties are important in predicting the fate and transport of chemicals in the environment. The structure of this database is compatible with the existing DIPPR® 801 database and DIADEM interface, and the compounds included are a subset of the compounds found in the DIPPR® 801 database. Thermodynamic relationships, chemical family trends, and predicted values were carefully considered when designating recommended values. Henry's law constants and infinite dilution activity coefficients were measured for toluene, 1-butanol, anisole, 1,2-difluorobenzene, …

The Effect Of Carbon Additives On The Microstructure And Performance Of Alkaline Battery Cathodes, Douglas Robert Nevers

Theses and Dissertations

This thesis describes research to understand the relationships between materials, microstructure, transport processes, and battery performance for primary alkaline battery cathodes. Specifically, the effect of various carbon additives, with different physical properties, on electronic transport or conductivity within battery cathodes was investigated. Generally, the electronic conductivity increases with carbon additives that have higher aspect ratios, smaller particle diameters, higher surface areas, and lower bulk densities. Other favorable carbon aspects include more aggregated and elongated carbon domains which permit good particleto-particle contacts. Of the various carbon additives investigated, graphene nanopowder was the best performer. This graphene nanopowder had the smallest particle …

Method And Apparatus For Measurement Of Fluid Properties, Feredoon Behroozi

Patents (University of Northern Iowa)

A method and apparatus for determining the contact angle and/or surface tension of a liquid on a solid surface is described. The method involves placing a fluid drop on a solid surface, and gradually increasing its volume by adding more fluid, while continuing to determine the corresponding increase in fluid height, until the drop attains maximum height beyond which additional fluid only increases the drop footprint and not height, and determining the equilibrium height and in turn the contact angle by means of an equation that correlates contact angle with depth below the fluid surface, together with the fluid surface …

Metal-Based Nanoparticle Interactions With The Nervous System: The Challenge Of Brain Entry And The Risk Of Retention In The Organism, Robert A. Yokel, Eric A. Grulke, Robert C. Macphail

Pharmaceutical Sciences Faculty Publications

This review of metal-based nanoparticles focuses on factors influencing their distribution into the nervous system, evidence they enter brain parenchyma, and nervous system responses. Gold is emphasized as a model metal-based nanoparticle and for risk assessment in the companion review. The anatomy and physiology of the nervous system, basics of colloid chemistry, and environmental factors that influence what cells see are reviewed to provide background on the biological, physical–chemical, and internal milieu factors that influence nervous system nanoparticle uptake. The results of literature searches reveal little nanoparticle research included the nervous system, which about equally involved in vitro and in …

Kinetics Of Tomato Peroxidase Inactivation By Atmospheric Pressure Cold Plasma Based On Dielectric Barrier Discharge, Patrick J. Cullen, Shashi Pankaj, N. Misra

Articles

Atmospheric pressure cold plasma technology is an emerging nonthermal food technology for microbiological decontamination of food and bio-materials. This study demonstrates the applicability of in-package cold plasma technology as a novel means to inactivation of enzymes. The kinetics of inactivation of tomato peroxidase as a model enzyme was studied at 30, 40 and 50kV, for up to 5’ of atmospheric air dielectric barrier discharge plasma treatments. The enzyme activity was found to decrease with both treatment time and voltage, the former variable exhibiting a more pronounced effect. Kinetic models viz. first-order, Weibull and logistic models were fitted to the experimentally …

Decoupling The Stationary Navier-Stokes-Darcy System With The Beavers-Joseph-Saffman Interface Condition, Yong Cao, Yuchuan Chu, Xiaoming He, Mingzhen Wei

Mathematics and Statistics Faculty Research & Creative Works

This paper proposes a domain decomposition method for the coupled stationary Navier-Stokes and Darcy equations with the Beavers-Joseph-Saffman interface condition in order to improve the efficiency of the finite element method. The physical interface conditions are directly utilized to construct the boundary conditions on the interface and then decouple the Navier-Stokes and Darcy equations. Newton iteration will be used to deal with the nonlinear systems. Numerical results are presented to illustrate the features of the proposed method.