Engineering Commons^™

Preparation And Characterization Of Pt-Ru Bimetallic Catalysts Using Electroless Deposition Methods And Mechanistic Study Of Re And Cs Promoters For Ag-Based, High Selectivity Ethylene Oxide Catalysts, Weijian Diao

Theses and Dissertations

Pt-Ru bimetallic catalysts are widely used for direct methanol fuel cells, biomass upgrading and hydrocarbon refining and offer unique properties compared to Pt or Ru monometallic catalysts due to ensemble effects, electronic effects, and/or bifunctional effects. To achieve better performance, strong metal-metal interactions and true bimetallic surface are needed. Electroless deposition (ED) methods are used in our laboratory to synthesize such bimetallic catalysts. In this study, two series of Ru@Pt/C (Pt deposited on Ru surfaces) and Pt@Ru/C (Ru deposited on Pt surfaces) catalysts have been synthesized. Characterization data from temperature programmed reduction (TPR), selective chemisorption, X-ray photoelectron spectroscopy (XPS), and …

Impact Of Formulation And Processing Parameters On Mechanical Properties Of Magadiite/Elastomer Composites, Yating Mao

Theses and Dissertations

This work seeks a better understanding of mechanical reinforcement and energy dissipation in elastomer composites containing the layered silicate magadiite (MGD, Na2Si14O29·nH2O). We characterized the elastomer’s accessibility into MGD interlayer spaces and studied the factors that influence the composite mechanical properties. We also compare the mechanical reinforcement of MGD with montmorillonite (MMT, a layered aluminosilicate clay mineral), which is widely used as filler in other kinds of nanocomposites. The study explores the grafting chemistry, vulcanization, and reinforcement mechanism in MGD/elastomer composites, which may help us to formulate the platelet/elastomer composites with superior mechanical properties and performance in the future. We …

Surface Modification Of Nanodiamond And Its Incorporation In Nanodiamond/Peek Nanocomposites, Zahidul Wahab

Theses and Dissertations

The continued miniaturization of electronic device components requires new lightweight polymers with high thermal stability, high thermal conductivity, low electrical conductivity, and low dielectric constant. Composites of nanodiamond (ND) and poly(ether ether ketone) (PEEK) are candidates for these applications due their unique combination of properties. The objectives of this research are to explore new routes for surface functionalization of nanodiamond (ND), develop methods for maximizing dispersion of ND as a nano-scale filler in PEEK, and characterize the effect of dispersed ND on the mechanical, thermal and dielectric properties of ND/PEEK composites. Initial attempts to disperse different kinds of commercially available, …

High Capacity Silicon Electrodes With Nafion As Binders For Lithium-Ion Batteries, Jiagang Xu, Qinglin Zhang, Yang-Tse Cheng

Chemical and Materials Engineering Faculty Publications

Silicon is capable of delivering a high theoretical specific capacity of 3579 mAh g⁻¹ which is about 10 times higher than that of the state-of-the-art graphite based negative electrodes for lithium-ion batteries. However, the poor cycle life of silicon electrodes, caused by the large volumetric strain during cycling, limits the commercialization of silicon electrodes. As one of the essential components, the polymeric binder is critical to the performance and durability of lithium-ion batteries as it keeps the integrity of electrodes, maintains conductive path and must be stable in the electrolyte. In this work, we demonstrate that electrodes consisting of …

Improving Renewable Energy Transition Acceptance: A Simulation Gaming Approach On A Multi Actor Setting In The Netherlands, Aziiz Sutrisno, Jac A. M. Vennix, Noor Syaifudin

Makara Journal of Technology

The Netherlands have tried very hard to increase their renewable energy sources (RES) shares to fulfill the European Union target in 2050. However, RES performance did not show the expected result as the performance declined in 2009 producing even wider gap compare to the target. The Dutch government’s tried to incorporate all interested stakeholders by forming the Dutch energy transition task force. Nevertheless, the task force’s result is also not showing a desirable trend. Key reasons behind the Dutch low RES performance are the lack of shared understanding and positive attitude toward RES development among interested actors. This research uses …

Dual-Band Singly-Fed Proximity-Coupled Tip-Truncated Triangular Patch Array For Land Vehicle Mobile System, Basari Basari, Josaphat Tetuko Sri Sumantyo

Makara Journal of Technology

This paper proposes a dual-band left-handed circularly polarized triangular-patch array that is developed for land vehicle mobile system aimed at mobile satellite communications. The array consists of six tip-truncated triangular patches, which the first three patches are used for reception and the second three patches are used for transmission purpose. Each of three-patches has a beam pattern that can be switched in three different 120°-coverage beam in azimuth-cut plane at a minimum targeted gain at a desired elevation angle. The targeted minimum gain of the array is 5 dBic, in order for data communications with a large geostationary satellite can …

Improvement Of Quality Of Carica Papaya L. With Clove Oil As Preservative In Edible Coating Technology, Eny Kusrini, Anwar Usman, Chrispine Deksita Wisakanti, Rita Arbianti, Dedy Alharis Nasution

Makara Journal of Technology

We have studied utilization of essential clove oil, extracted from clove buds by hydrodistillation, as preservative in edible packaging technology. Preservative of essential clove oil was applied on chopped papaya fruits by using two methods, namely spray and brush. The effects of concentration of clove oil from 0.05 to 0.20% on the preservation of papaya fruits (Carica papaya L.) at room temperature (25 °C) were also evaluated. Physicochemical and in vitro microbiological activities on the papaya fruits that were stored at 25 oC and 85-90% relative humidity were investigated in details. The results indicate that the clove oil at concentration …

Calibration Of Numerical Model For Shoreline Change Prediction Using Satellite Imagery Data, Sigit Sutikno, Keisuke Murakami, Dwi Puspo Handoyo, Manyuk Fauzi

Makara Journal of Technology

This paper presents a method for calibration of numerical model for shoreline change prediction using satellite imagery data in muddy beach. Tanjung Motong beach, a muddy beach that is suffered high abrasion in Rangsang Island, Riau province, Indonesia was picked as study area. The primary numerical modeling tool used in this research was GENESIS (GENEralized Model for Simulating Shoreline change), which has been successfully applied in many case studies of shoreline change phenomena on a sandy beach.The model was calibrated using two extracted coastlines satellite imagery data, such as Landsat-5 TM and Landsat-8 OLI/TIRS. The extracted coastline data were analyzed …

Oxidation Process Of H 2 O /Uv For Cod Reduction Of Wastewater From Soybean Tofu Production, Komala Pontas, Abrar Muslim

Makara Journal of Technology

Chemical Oxygen Demand (COD) reduction of wastewater from soybean tofu production was studied by conducting advanced oxidation process (AOP) using hydrogen peroxide with UV radiation catalysts in a closed cylindrical glass reactor. The hydroxyl radical (*OH) concentration from H2O2 decomposition was modeled, and exponential trends were found for the *OH concentration over radiation time and operation temperature. As a result, it was found that the maximal *OH concentration was 0.209 mol L-1 at 240 minutes and 50 °C. The *OH concentration exponentially increased following rise in operation temperature. The H2O2/UV AOP application reduced COD concentration to approximately 42.41% from 10,545 …

Uplift Of Shoreline Regions On Pagai Island Due To The September 12, 2007 Mw 8.4 Earthquake Captured By Sar Image, Ashar Muda Lubis

Makara Journal of Technology

At least 25 people were killed by the September 12, 2007 Mw 8.4 Bengkulu earthquake, and many buildings were destroyed in Bengkulu and West Sumatra provinces. It is very important to estimate the earth surface deformation due to the earthquake to understand the rupture size and its process. The aim of this research is to estimate the shoreline change and vertical displacement on Pagai Island associated with the September 12, 2007 Mw 8.4 Bengkulu earthquake. The intensity of ALOS-PALSAR satellite images is used to access the pattern of displacement. The result shows that Pagai Island demonstrated huge uplift due to …

Effect Of Fly Ash Fortification In The Manufacture Process Of Making Concrete Towards Characteristics Of Concrete In Sulfuric Acid Solution, Asep Handaya Saputra, Muhammad Shohibi, Masatoshi Kubouchi

Makara Journal of Technology

Fly ash is a silica or alumino silica material that can be used as a constituent of cement in the concrete manufacturing process. Utilization of fly ash aims to improve durability and minimize the reduction of concrete’s compressive strength exposed to an acidic environment, which can be achieved through the pozzolanic reaction of fly ash with Ca(OH)2 within concrete. The reduced content of Ca(OH)2 through pozzolanic reaction will minimize the tendency of ettringite formation (compounds that cause deterioration and decrease the compressive strength of concrete). In order to determine the relation between fly ash replenishment into concrete with concrete’s characteristics …

Independency Of Elasticity On Residual Stress Of Room Temperature Rolled Stainless Steel 304 Plates For Structure Materials, Parikin Parikin, David Allen

Makara Journal of Technology

Mechanical strengths of materials are widely expected in general constructions of any building. These properties depend on its formation (cold/hot forming) during fabrication. This research was carried out on cold-rolled stainless steel (SS) 304 plates, which were deformed to 0, 34, 84, and 152% reduction in thickness. The tests were conducted using Vickers method. Ultra micro indentation system (UMIS) 2000 was used to determine the mechanical properties of the material, i.e.: hardness, modulus elasticity, and residual stresses. The microstructures showed lengthening outcropping due to stress corrosion cracking for all specimens. It was found that the tensile residual stress in a …

Strategies For The Production Of Cell Wall-Deconstructing Enzymes In Lignocellulosic Biomass And Their Utilization For Biofuel Production, Sang-Hyuck Park, Rebecca Garlock Ong, Mariam Sticklen

Department of Chemical Engineering Publications

Microbial cell wall-deconstructing enzymes are widely used in the food, wine, pulp and paper, textile, and detergent industries and will be heavily utilized by cellulosic biorefineries in the production of fuels and chemicals. Due to their ability to use freely available solar energy, genetically engineered bioenergy crops provide an attractive alternative to microbial bioreactors for the production of cell wall-deconstructing enzymes. This review article summarizes the efforts made within the last decade on the production of cell wall-deconstructing enzymes in planta for use in the deconstruction of lignocellulosic biomass. A number of strategies have been employed to increase enzyme yields …

Sustainability Assessment For Energy Systems And Chemical Process Industries, Michael J. Matzen

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Sustainability has become an important factor in the chemical process and energy industries with a strong drive for process improvements towards more environmentally conscious solutions. However, there are many ways of defining sustainability and even more ways of trying to determine how sustainable a process is. This work looks into applying a conjunction of tools including; process simulation, multi-criteria decision matrices and life-cycle assessment to more quantitatively determine sustainability metrics. We have applied these tools for the production of electricity, methanol and dimethyl ether. A novel method of electricity production, in chemical looping combustion (CLC), was used that inherently involves …

New Visible Light Absorber For Solar Fuels : Ga(Sbx)N1-X Alloys., Swathi Sunkara

Electronic Theses and Dissertations

Solar energy conversion to fuels via photoelectrochemical water splitting is one of the most important technological directions toward meeting the global energy and environmental challenge. However, till date, there are no suitable semiconductor materials available that can absorb visible light, possess right kind of band edge energetics and are stable in aqueous environments. In this work, a new III-V alloy material Ga(Sbx)N1-x with dilute antimony concentration is proposed and developed for photoelectrochemical water splitting. Experimental studies were conducted first to synthesize the proposed alloy materials to understand structure-property relationships and compare them to those obtained using first principles computations. Finally, …

Simulation Of Lateral Migration And Sedimentation Of A Flexible Fiber In A Vertical Weak Shear Flow, Ali Ibrahim Neamah Neamah

Masters Theses

This research is a thorough numerical investigation and critical analysis of lateral migration of a deformable particle settling in a vertical weak shear flow. Under the vertical weak shear fluid, the deformable particle may move either to the coagulation area, or the dispersion area, depending on Reynolds numbers, shear Reynolds number, fiber flexibility, and aspect ratio. In this study, a lattice Boltzmann equation is used to solve Navier-Stokes equation and a flexible particle method is employed to attack the problem of motion of a flexible fiber. A bounce-back rule is used to deal with moving boundaries interacting with fluids. Several …

Targeted Products From Fast-Hydropyrolysis And Hydrodeoxygenation Of Biomass, Ian Tad Smith

Open Access Theses

Previously, the H2Bioil process was proposed as a possible way to convert sustainably available intact biomass into liquid fuels. The optimization of this process and possible synergies with other biomass conversion processes are presented in this thesis.

The selectivity of the PtMo hydrodeoxygenation catalyst was tuned using two different hydrogen partial pressures: 25 bar, and 2.5 bar. This effect was studied on cellulose and intact biomass samples to determine the effect that hydrogen has upon the retention of aromatic compounds found in intact biomass. These experiments show that it is possible for the hydrogenation activity of the PtMo catalyst to …

Field Amplified Sample Stacking On Amyloid Beta (1-42) Oligomers Using Capillary Electrophoresis, Sadia Ali Paracha

Graduate Theses and Dissertations

According to recent literature, it is believed that the oligomeric form of amyloid beta (Aβ) is the leading cause of Alzheimer’s disease (1; 8; 10; 12-18). Additionally, recent studies have eluded to the impact of Alzheimer’s disease (AD) both economically and Socially in today’s society where an increase of about 71% of AD related deaths were recorded between 2000 and 2013 (7). Since the oligomeric forms of Aβ vary in size, shape and some believe conformation, it is vital to utilize a separation technique, such as capilllary electrophoresis (CE) to further understand Aβ aggregation. By understanding Aβ aggregation, treatment of …

Effects Of Magnetically Induced Micro-Mixing On Nanofiltration Performance, Guanghui Song

Graduate Theses and Dissertations

Nanofiltration (NF) is a relatively new membrane separation process mainly used for removing low molecular weight species from aqueous and non-aqueous solutions. NF membranes suffer from concentration polarization leading to membrane fouling thus compromised membrane performance. Magnetically responsive nanofiltration (NF) membranes functionalized with superparamagnetic nanoparticles (SPNs) attached to the chain ends of grafted polymer nanolayers have been shown to be effective in breaking concentration polarization at the membrane-liquid interface under an appropriate external oscillating magnetic field. Under an oscillating magnetic field, the movement of the polymer chains acts as micro-mixer leading to the suppression of concentration polarization and improved filtration …

Heat Transfer Mechanisms In Water-Based Nanofluids., Masoudeh Ahmadi

Electronic Theses and Dissertations

Nanofluids are a class of heat transport fluids created by suspending nano-scaled metallic or nonmetallic particles into a base fluid. Some experimental investigations have revealed that the nanofluids have remarkably higher thermal conductivities than those of conventional pure fluids and are more suited for practical application than the existing techniques of heat transfer enhancement using millimeter and/or micrometer-sized particles in fluids. Use of nanoparticles reduces pressure drop, system wear, and overall mass of the system leading to a reduction in costs over existing enhancement techniques. In this work, the heat transfer coefficient is determined experimentally using copper oxide (CuO) based …

Plasma Catalysis Using Low Melting Point Metals., Maria Carreon

Electronic Theses and Dissertations

Plasma catalysis is emerging as one of the most promising alternatives to carry out several reactions of great environmental importance, from the synthesis of nanomaterials to chemicals of great interest. However, the combined effect of a catalyst and plasma is not clear. For the particular case of 1-D nanomaterials growth, the low temperatures synthesis is still a challenge to overcome for its scalable manufacturing on flexible substrates and thin metal foils. Herein, the use of low-melting-point metal clusters under plasma excitation was investigated to determine the effectiveness in their ability to catalyze the growth of 1-D nanomaterials. Specifically, plasma catalysis …

Formulation And Evaluation Of Soy Polymer Based, Gravure Printed Resistive Inks For Applications In Printed Electronics, Bhushan Hiralal Patil

Masters Theses

Today, the majority of the commercially available conductive inks are formulated using expensive metallic particles, such as silver and gold. Most of the inks use volatile solvents in the formulation, which are hazardous to the environment as emission of VOCs is the major concern. In the case of water-based inks, usually petroleum-based acrylic polymers are used. Apart from being nonrenewable raw materials, acrylic polymers are carcinogenic in nature. Also, acrylic polymers are used in a variety of applications, such as the automotive, medical device, paint, and adhesive industries. Often times, the ink industry has to compete with other industries for …

Evapoporometry: An Effective Analytical Technique For Membrane Pore Size Characterization Of Hollow Fiber Membranes, Alex J. Moix

Chemical Engineering Undergraduate Honors Theses

A new analytical technique called evapoporometry has shown to be an effective and inexpensive method for membrane pore size characterization. This technique is based on the correlation between vapor pressure and pore size as described by the Kelvin equation. Evapoporometry has many advantages over tradition pore size characterization techniques. This technique allows for large sample sizes, uses minimal equipment, is capable of analyzing membranes within a wide range of pore sizes, and provides a highly descriptive representation of the pore distribution. This research looks at the application of evapoporometry as a technique for characterization of hollow fiber membranes. Using the …

Stochastic Simulation Of Lagrangian Particle Transport In Turbulent Flows, Guangyuan Sun

Theses and Dissertations

This dissertation presents the development and validation of the One Dimensional Turbulence (ODT) multiphase model in the Lagrangian reference frame. ODT is a stochastic model that captures the full range of length and time scales and provides statistical information on fine-scale turbulent-particle mixing and transport at low computational cost. The flow evolution is governed by a deterministic solution of the viscous processes and a stochastic representation of advection through stochastic domain mapping processes. The three algorithms for Lagrangian particle transport are presented within the context of the ODT approach. The Type-I and -C models consider the particle-eddy interaction as instantaneous …

Design And Synthesis Of Polymer, Carbon And Composite Electrodes For High Energy And High Power Supercapacitors, Margarita Arcila-Velez

All Dissertations

Supercapacitors (SCs) are promising energy storage devices because they deliver energy faster than Li-ion batteries and store larger amounts of charge compared to dielectric capacitors. SCs are classified in electrical double layer capacitors (EDLCs) and pseudocapacitors, based on their charge storage mechanism. EDLCs store charge electrostatically, i.e. by physical charge separation. This mechanism limits the storable amount of energy to the available surface area of the electrode, typically made of carbon materials, but grants good cycling stability of the SC device. Pseudocapacitor electrodes, commonly made of conducting polymers or metal oxides, store charge faradaically, i.e. through redox reactions throughout the …

Separation Of Oil From A Brackish Water Stream, Kayli A. Quinton

Chemical Engineering Undergraduate Honors Theses

In the past 40 years, a variety of enhanced oil recovery (EOR) methods have been developed and applied to mature and mostly depleted oil reservoirs. Chemical and sonic stimulation are two enhanced oil recovery methods in which emulsions are created either as a primary or secondary effect. The resulting emulsion viscosity is considerably lower than that of dry crude thus increasing permeability of and recovery from pay zones. During Chemical enhanced oil recovery, caustic or preformed surfactants are injected into oil reservoirs, which results in flooding and periodic breakthrough of stable oil-water emulsions. The emulsions from chemical enhanced oil recovery …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

Optimization Of Pyrochlore Catalysts For The Dry Reforming Of Methane, Felipe Polo Garzon

All Dissertations

The conversion of methane into syngas (a mixture of CO and H2), which can be further converted into a variety of chemicals and particularly liquid fuels, is of growing importance given recent increases in methane production world-wide. Furthermore, since using CO2 as the co-feed offers many environmental advantages, dry reforming of methane (DRM, CH4 + CO2 ⇌ 2CO + 2H2) has received renewed attention. In recent years, experimentalists have shown that the Rh-substituted lanthanum zirconate pyrochlore (LRhZ) material is catalytically active for DRM, exhibits long-term thermal stability and resists deactivation; however, previous to this doctoral work, a detailed understanding of …

Galvanic Corrosion Of Magnesium Coupled To Steel At High Cathode-To-Anode Area Ratios, Dila Ram Banjade

Theses and Dissertations

In this study, the impact of galvanic coupling of magnesium to steel on the corrosion rate, surface morphology, and surface film formation was investigated. In particular, the role of self-corrosion was quantified as previous studies showed discrepancies between model predictions and experimental results that were likely due to significant self-corrosion. This experimental study examined the corrosion of Mg coupled to steel in 5 wt% NaCl at cathode-to-anode area ratios that ranged from 5 to 27. Results showed that self-corrosion was significant and accounted for, on average, one-third of total corrosion. Moreover, self-corrosion varied with time and cathode size, and was …

Modified Polysulfone Nanofiltration Membrane Synthesis For Hydraulic Fracturing Water Recycle, Blake Alexander Johnson

Graduate Theses and Dissertations

The use of hydraulic fracturing has resulted in significant increases in the yield of oil and natural gas, as water pumped into wells at high pressure cracks the formations and releases the hydrocarbons that are locked in the rocks. This process has created large volumes of brackish water that is very difficult to process and is often disposed of into injection wells. Suspended solids and some dissolved solids are more readily removed, but the multivalent ions found in certain salts can precipitate in a well and complicate the reuse of flowback in future hydraulic fracturing operations.

Nanofiltration, a membrane separation …