Engineering Commons^™

Cztsse Thin Film Solar Cells : Surface Treatments, Chinmay S. Joglekar

Open Access Theses

Chalcopyrite semiconducting materials, specifically CZTS, are a promising alternative to traditional silicon solar cell technology. Because of the high absorption coefficient; films of the order of 1 micrometer thickness are sufficient for the fabrication of solar cells. Liquid based synthesis methods are advantageous because they are easily scalable using the roll to roll manufacturing techniques.

Various treatments are explored in this study to enhance the performance of the selenized CZTS film based solar cells. Thiourea can be used as a sulfur source and can be used to tune band gap of CZTSSe. Bromine etching can be used to manipulate the …

Mechanistic Study Of The Hydrothermal Reduction Of Palladium On The Tobacco Mosaic Virus, Oluwamayowa Oluwarotimi Adigun

Open Access Theses

Synthesis of nanorods and nanowires is becoming more and more important due to interest in them in a wide range of disciplines. The genetically engineered tobacco mosaic virus (TMV1Cys) provides a template for synthesis of uniform metal nanorods at mild operating conditions and without the use of any expensive technology compared to conventional synthetic methods. The discovery of the hydrothermal synthetic scheme has allowed the production of higher quality nanorods on the TMV template. However, the mechanism for reduction and growth in this process is still not understood. In this paper, the mechanism of synthesis for producing uniform, controllable palladium …

Dynamic Characteristic Identification Of Seismic-Excited Multi-Story Buildings Through Response-Only Technique, Agung Budipriyanto, Priyo Suprobo

Makara Journal of Technology

Identifying dynamic characteristics of civil engineering structures is still a challenging task. It intends to assess behavior of the structures under time-dependent loads. This paper discusses a methodology suitable for identifying the characteristics of multi-story buildings using only their measured response under earthquake ground excitations. Appropriateness of technique used for structural identification was corroborated through coherence of the structure’s responses. The methodology was applied for identifying the characteristics of 14-story and 20-story office buildings located in a high seismic region. Responses of these two buildings recorded during three different seismic ground motions were investigated. The buildings’ response spectral densities and …

Synthesis And Characterization Of Soy-Based Polyurethane Foam With Utilization Of Ethylene Glycol In Polyol, Flora Elvistia Firdaus

Makara Journal of Technology

The use of vegetable oils on replacing petroleum has attracted attention of many researchers. The chemical structure of vegetable oils are different from petrochemicals, so the structure of soybean oil has to be chemically modified through its unsaturated fatty acid chain in triglyceride. A two step process was conducted for the preparation of soy-polyol in designated temperatures; 50 °C, 60 °C, and 70 °C. Ethylene glycol (EG) as co-reagent was taking part in soy-polyol synthesis, and the soy-polyol was used as a sole polyol for polyurethane synthesis. Referred to the previous study, the existence of EG in polyurethane synthesis can …

Performances Of Free-Space Optical Communication System Over Strong Turbulence, Ucuk Darusalam, Purnomo Sidi Priambodo, Harry Sudibyo, Eko Tjipto Rahardjo

Makara Journal of Technology

We report an experimental of free-space optical communication (FSOC) system that use tube propagation simulator (TPS) as the turbulence medium. The FSOC system use wavelength of 1550 nm at the rate transmission of 1000 Mbps and amplified with EDFA at the output of +23 dBm. Index structure of 10-15–10-13 as the representation of atmosphere index turbulences are used for simulation of intensity distribution model or scintillation. The simulation use gammagamma and K model as well. The beam wave propagation models used in simulation are plane wave, spherical wave and Gaussian wave. Spherical wave achieves highest performance via gamma-gamma in strong …

Preparations Of Nanostructured Silicide Bundles And Oxide Arrays, Hirokazu Tatsuoka, Wen Li, Erchao Meng, Daisuke Ishikwa, Kaito Nakane, Shingo Oda, Tomoji Matsushita, Natsuki Kurebayashi

Makara Journal of Technology

A variety of nanostructured silicide bundles and oxide nanowire arrays with abundant, non-toxic materials we are prepared. The CrSi2 nanowire and Mg2Si/MgO composite nanowire bundles were synthesized using a Si substrate and a SiOx nanofiber bundle, respectively. The hexagonal MoSi2 nanosheet bundles were also synthesized using a MoS2 layered material as a template. In addition, ZnO, CuO/Cu2O and a-Fe2O3 nanowire arrays were prepared on semiconductor or metallic substrates. The growth phenomena and the structural properties of the nanostructured materials awere investigated. In addition, the preparations of axial and radial nanowire structures weare examined.

Bioethanol Production From Iles-Iles And Sorghum Starch As Raw Materials (Effect Of Cacl 2 Addition And Saccharification Time), Kusmiyati Kusmiyati, Ali Mahmudi

Makara Journal of Technology

Bioethanol produced from agricultural sources is one alternative energy that has been developed to substitute for petroleum. However, the use of food sources such as corn and cassava to produce bioethanol still face obstacles that lead to the scarcity of food and an increase in food prices. The aim of this study was to produce bioethanol from sorghum and iles-iles, which are not used by humans as food, especially in Indonesia. For both materials, the variables studied were saccharification time (4, 8, 24, and 48 h) and concentration of CaCl2 added to the liquefaction slurry (0, 100, 200, 300, and …

The Effect Of Zephyr Layer Orientation On Zephyrboard Made From Oil Palm Petiole, Lusita Wardani, Muhamad Yusram Massijaya, Yusuf Sudo Hadi, I Wayan Darmawan

Makara Journal of Technology

It is very important to utilize oil palm petiole for the production of zephyr boards. This study aimed to analyze the effect of layer orientation on zephyr board quality. Zephyr boards were made with three coating patterns (A = cross perpendicular, B= combine A and C, and C= paralell) and five zephyr layers using urea formaldehyde adhesive. They were pressed for 20 min at a pressure of 25 kgf/cm² and a temperature 120 ºC, to a target density of 0.80 g/cm³ and a size of 300 mm X 300 mm X 12 mm. Our results showed that the physical and …

Performance Evaluation Of An Optimized Floating Breakwater In Oblique Waves With A Higher-Order Boundary Element Method, Faisal Mahmuddin, Masashi Kashiwagi

Makara Journal of Technology

In the previous study, the optimal performance of a two-dimensional (2D) floating breakwater shape was obtained. The performance of this shape was also confirmed with a model experiment in a towing tank. Moreover, the shape’s performance in three dimensions (3D) was investigated in a subsequent study. However, to predict the shape’s performance in a real application more accurately, the shape’s characteristics in oblique waves must also be evaluated. In this study, the performance and characteristics of the model (hydrodynamic forces, body motions, wave elevations, and drift forces) are computed using a higher-order boundary element method (HOBEM). The HOBEM, which is …

Recruitment Of The Adaptor Protein Grb2 To Egfr Tetramers, Noga Kozer, Dipak Barua, Christine Henderson, Eduoard C. Nice, Antony W. Burgess, William S. Hlavacek, Andrew H. A. Clayton

Chemical and Biochemical Engineering Faculty Research & Creative Works

Adaptor protein Grb2 binds phosphotyrosines in the epidermal growth factor (EGF) receptor (EGFR) and thereby links receptor activation to intracellular signaling cascades. Here, we investigated how recruitment of Grb2 to EGFR is affected by the spatial organization and quaternary state of activated EGFR. We used the techniques of image correlation spectroscopy (ICS) and lifetime-detected Förster resonance energy transfer (also known as FLIM-based FRET or FLIM-FRET) to measure ligand-induced receptor clustering and Grb2 binding to activated EGFR in BaF/3 cells. BaF/3 cells were stably transfected with fluorescently labeled forms of Grb2 (Grb2-mRFP) and EGFR (EGFR-eGFP). Following stimulation of the cells with …

Viologen Oxidation Properties, Adam Read, Dr. William Pitt

Journal of Undergraduate Research

The world always stands in need of a more efficient and low cost energy sources. Fuel cells present an environmentally friendly source of energy that could potentially replace the current fossil fuels that are now used. In addition fuel cells are normally light weight and have the ability to work in isolated regions where power is not easily accessible. Fuel cells have shown great potential but as of yet are not an economically favorable energy source due to high cost. One of the main reasons for this is the high cost of platinum which is commonly used as a catalyst. …

Encapsulating Liposomes For Stabilized Drug Delivery, Corbin Jacobs, Dr. William Pitt

Journal of Undergraduate Research

Liposomes are tiny vesicles composed of materials similar to a cell membrane’s bilayer and “are useful for delivering anticancer agents to tumors and reducing the severe side effects of the agents.”1 Following synthesis, liposomes containing drug are administered intravenously. Fortunately, tumors have hyperpermeable vasculature which facilitates liposomal accumulation by their leaking out of the capillaries surrounding the tumor.2 Once near the tumor, individual cells will endocytose or engulf the vesicles as long as they are between 10 nm and 1000 nm.3

Field Application Of Accelerated Mineral Carbonation, Brandon Reynolds, K. J. Reddy, Morris D. Argyle

Faculty Publications

Globally, coal-fired power plants are the largest industrial source of carbon dioxide (CO₂). CO₂ emissions from flue gas have potential for direct mineralization with electrostatic precipitator fly ash particles in the field. Demonstration scale accelerated mineral carbonation (AMC) studies were conducted at the Jim Bridger Power Plant, a large coal fired power plant located in Wyoming, USA. AMC produces kinetically rapid conditions for increased rates of mineralization of CO₂, sulfur dioxide (SO₂) and mercury (Hg) on fly ash particles. Control and AMC reacted fly ash particles were investigated for: change in carbon (expressed …

A2 Protein Incorporation Into The Qβ Virus-Like Particle, Derek Bush, Dr. Band Bundy

Journal of Undergraduate Research

Virus-like Particles (VLPs) are noninfectious synthetic copies of the outer protein shell of viruses. They are highly symmetrical nanostructures that self-assemble from approximately 200 copies of a single “coat” protein. This symmetry makes attachment of singular foreign entities to the VLPs difficult, which limits their current uses in medical and engineering applications. In this research project we have worked to demonstrate the insertion of a single copy of the “A2” protein into the VLP from the Qβ bacteriophage to serve as a possible location for future site-specific VLP modification. Ultimately we believe that this work will lead to the development …

Cfd Black Liquor Bed Simulation, Benjamin Ohran, Dr. Larry Baxter

Journal of Undergraduate Research

The objective of this project was to further the understanding of the bed region of a black liquor recovery boiler. The net output of carbon dioxide from burning black liquor (a paper pulping by-product) is zero, making it a desirable alternative fuel source; however, there are other problems associated with burning black liquor such as boiler fouling, and emissions of pollutants. With the understanding gained from this project it will be possible to further improve the efficiency and emissions of black liquor boilers, making it a more viable fuel alternative.

Co2 Recycling Using Microalgae For The Production Of Fuels, Michael H. Wilson, John Groppo, Andrew Placido, S. Graham, S. A. Morton Iii, Eduardo Santillan-Jimenez, Aubrey Shea, Mark Crocker, Czarena Crofcheck, Rodney Andrews

Center for Applied Energy Research Faculty and Staff Publications

CO₂ capture and recycle using microalgae was demonstrated at a coal-fired power plant (Duke Energy’s East Bend Station, Kentucky). Using an in-house designed closed loop, vertical tube photobioreactor, Scenedesmus acutus was cultured using flue gas as the CO₂ source. Algae productivity of 39 g/(m² day) in June–July was achieved at significant scale (18,000 L), while average daily productivity slightly in excess of 10 g/(m² day) was demonstrated in the month of December. A protocol for low-cost algae harvesting and dewatering was developed, and the conversion of algal lipids—extracted from the harvested biomass—to diesel-range hydrocarbons via catalytic …

Porous Nanocomposites With Integrated Internal Domains: Application To Separation Membranes, Wenle Li, John Y. Walz

Chemical and Materials Engineering Faculty Publications

Asymmetric membranes with layered structure have made significant achievements due to their balanced properties and multi-functionalities that come from a combination of multiple layers. However, issues such as delamination and substructure resistance are generated by the intrinsic layered structure. Here, we present a strategy to integrate the traditional layered structure into an asymmetric but continuous porous network. Through infiltrations of microparticles and nanoparticles to targeted regions, active domains are created inside the porous scaffold versus having them applied externally. The fabricated internal active domains are highly adjustable in terms of its dimensions, pore size, and materials. We demonstrate that it …

Investigation Of Tio2 And Invo4-Tio2 Semiconductors For The Photocatalytic Degradation Of Aqueous Organics, Sandra L. Pettit

USF Tampa Graduate Theses and Dissertations

Water is a vital natural resource. To develop more sustainable water systems, we must focus efforts on the removal of persistent contaminants. Aqueous organic contaminants include azo dyes, halogenated organics (e.g. pesticides), and algal and bacterial metabolites. The latter are common to surface waters and freshwater aquaculture systems and can cause taste and odor problems. Two of the principal organoleptic compounds are geosmin and 2-methylisoborneol (MIB). Traditional oxidation treatment methods, utilizing chlorine, hydrogen peroxide, and potassium permanganate, have been employed with varying levels of efficacy for removal of these and other organic contaminants. Advanced Oxidation Processes (AOPs) have greater potential …

Influence Of Reduction Promoters On Stability Of Cobalt/Γ-Alumina Fischer-Tropsch Synthesis Catalysts, Gary Jacobs, Wenping Ma, Burtron H. Davis

Center for Applied Energy Research Faculty and Staff Publications

This focused review article underscores how metal reduction promoters can impact deactivation phenomena associated with cobalt Fischer-Tropsch synthesis catalysts. Promoters can exacerbate sintering if the additional cobalt metal clusters, formed as a result of the promoting effect, are in close proximity at the nanoscale to other cobalt particles on the surface. Recent efforts have shown that when promoters are used to facilitate the reduction of small crystallites with the aim of increasing surface Co⁰ site densities (e.g., in research catalysts), ultra-small crystallites (e.g., < 2–4.4 nm) formed are more susceptible to oxidation at high conversion relative to larger ones. The choice of promoter is important, as certain metals (e.g., Au) that promote cobalt oxide reduction can separate from cobalt during oxidation-reduction (regeneration) cycles. Finally, some elements have been identified to promote reduction but either poison the surface of Co⁰ (e.g., Cu), or produce excessive light gas selectivity (e.g., Cu and Pd, or Au at …

A Reactor Model For Hydrogen Generation From Sodium Borohydride And Water Vapor, Lin Yu, Michael A. Matthews

Faculty Publications

This paper reports new data on the production of hydrogen from water vapor plus NaBH4, or NaBH4 þ 10% CoCl2. Data were collected with the aid of an isothermal semi-batch reactor with in-situ H2 rate measurement. The reaction of NaBH4 to generate H2 proceeds via three steps: deliquescence, dissolution and reaction. The deliquescence regime of NaBH4 in the presence of 10 weight percent CoCl2 is defined. The H2 yield is quantified at various reaction conditions (reaction temperature 70-120 C, relative humidity 31-69%). CoCl2 significantly accelerates the rate of H2 production compared to deliquescence + reaction of pure NaBH4. It is …

2014 Chemical And Biomolecular Graduate Research Symposium Program, Clemson University

Chemical and Biomolecular Graduate Research Symposium

Program for the 2014 Graduate Research Symposium in Holmes Ballroom - Clemson House.

Theoretical Framework For Multiple-Polymorph Particle Precipitation In Highly Supersaturated Systems, B. B. Schroeder, D. D. Harris, S. T. Smith, D. O. Lignell

Faculty Publications

An overarching mathematical framework is proposed to describe entire mineral particle precipitation processes, including multiple polymorphic forms and ranges of temperatures. While existing models portray individual physical phenomena, the presented approach incorporates a diverse set of the physical phenomena simultaneously within a single mathematical description. The liquid and solid phase dynamics interact through coupling an aqueous ionic equilibrium-chemistry model with a set of population balance equations and a mixing model. Including the particle physical phenomena, nucleation, growth, dissolution, and aggregation together within a single framework allows for the exploration of nonintuitive and nontrivial coupling effects. To validate the proposed framework, …

Phase Transitions Of Perfluorocarbon Nanoemulsion Induced With Ultrasound: A Mathematical Model, William G. Pitt, Ram N. Singh, Krystian X. Perez, Ghaleb A. Husseini, Daniel R. Jack

Faculty Publications

While ultrasound has been used in many medical and industrial applications, only recently has research been done on phase transformations induced by ultrasound. This paper presents a numerical model and the predicted results of the phase transformation of a spherical nanosized droplet of perfluorocarbon in water. Such a model has applications in acoustic droplet vaporization, the generation of gas bubbles for medical imaging, therapeutic delivery and other biomedical applications. The formation of a gas phase and the subsequent bubble dynamics were studied as a function of acoustic parameters, such as frequency and amplitude, and of the physical aspects of the …

Porous Titania Microspheres With Uniform Wall Thickness And High Photoactivity, Xinhua Liang, Rajankumar L. Patel

Chemical and Biochemical Engineering Faculty Research & Creative Works

Highly porous titania particles were prepared by depositing thin films of titania, using alternating reactions of TiCl4 and hydrogen peroxide, on poly(styrene-divinylbenzene) (PS-DVB) template particles via atomic layer deposition (ALD) at 77 C. The composition of the titania films was verified by XPS analysis, and the titania films were directly observed by TEM. TGA/DSC was used to study the thermal decomposition of the polymer template. Porous titania particles with uniform wall thicknesses were successfully obtained after the template PS-DVB was removed by oxidation in air at 400 C for 24 h. Verification of the resulting porous structure of the titania …

Pulse Electrodeposition Of Pd-Ni Alloy Nanoparticles For Electrocatalytic Oxidation Of Formic Acid, Fang-Zu Yang, Jun-Pei Yue, Zhong-Qun Tian, Shao-Min Zhou

Journal of Electrochemistry

The Pd-Ni alloy nanoparticles with nickel atomic contents of 12.0%, 16.4% and 22.6% were successfully electrodeposited from a Pd-Ni alloy electrolyte by square wave pulse plating. The alloy nanoparticles were in the spherical shape with a diameter of 50 ~ 80 nm. As the growth potential of the alloy was negatively shifted, the nickel content of the alloy was increased, and the size of the nanoparticles was almost the same, whereas the number, the degree of crosslinking and the real active area of the nanoparticles were increased. As the nickel content of the alloy nanoparticles increased, the peak current for …

Synthesis And Electrochemical Properties Of Lico1-XMgXMno4 And Lico1-XAlXMno4 (X= 0, 0.02, 0.05, 0.1) As Positive Materials For Lithium-Ion Batteries, Mei-Ling You, Qing-Song Tong, Xiu-Hua Li, Min Lin, Xing-Kang Huang, Yong Yang

Journal of Electrochemistry

The Al-doped and Mg-doped LiCoMnO₄ materials were synthesized through solid-state reaction. The effects of doping amounts of Mg and Al on the initial capacities, discharge plateaus, and cycle performances were investigated. The morphologies and structures of the as-prepared materials were studied by scanning electron microscopy and powder X-ray diffraction. The results indicate that the as-prepared samples were composed of uniform, well-crystallized particles. The pristine LiCoMnO₄ possessed an initial capacity of 87.0 mAh·g^-1, while LiCo_0.98Mg_0.02MnO₄ and LiCo_0.98Al_0.02MnO₄ delivered 91.3 and 93.6 mAh·g^-1, respectively. The proper …

Fabrication And Impedance Performance Of Gradient Lani0.6Fe0.4O3-δ-Gd0.2Ce0.8O2 Composite Cathodes For Intermediate Temperature Solid Oxide Fuel Cell, Yang Li, Bo Huang, Meng Yuan, Zhi-Qiu Zhang, Zong-Yao Liu, Xu-Chen Tang, Xin-Jian Zhu

Journal of Electrochemistry

A LNF-GDC composite cathode with a gradual change in the composition between ScSZ electrolyte and LNF cathode was fabricated to reduce the cathode polarization resistance (R_p). The gradual change in composition between ScSZ electrolyte and LNF cathode shows the decreases in the charge transfer resistance (R_ct) and gas phase diffusion resistance (R_d). The results revealed that the Rp value, measuring 0.452 Ω·cm² at 750 °C, was the lowest for LNF-GDC composite cathodes with three layers and gradient changes in composition between ScSZ and LNF (Cathode C),, whereas the Rp value of 70%LNF-30%GDC composite …

Study On Carbon Supported Pd Catalysts Modified By Phosphomolybdic Acid For H2O2 Electrocatalytic Reduction, Li-Mei Sun, Cheng Zhang, Ying-Rong Bao, Hong-Xia Li

Journal of Electrochemistry

The Pd/C catalyst was prepared with the chemical reduction method, and phosphomolybdic acid (PMA) was modified on the Pd/C catalyst using the dipping method. The compositions and structures of the Pd/C and Pd/C modified by phosphomolybdic acid (PMA-Pd/C) catalysts were characterized with X-ray diffraction and Fourier Transform infrared spectroscopy analyses. The electrocatalytic activity and stability of the catalysts for the reduction of hydrogen peroxide (H₂O₂) were studied using cyclic voltammetry and chronoamperometry. The results showed that the phosphomolybdic acid was tightly fixed on the surface of Pd/C catalyst through the chemical interaction. The eletrocatalytic activity of …

Preparation Of Pd/Tio2/C Catalyst And Its Electrocatalytic Performance In Basic Solution For Ethanol Oxidation, Qiao-Xia Li, Yi-Chao Yang, Ming-Shuang Liu, Hong-Min Mao, Qun-Jie Xu

Journal of Electrochemistry

Nanoparticles TiO₂ were prepared by hydrothermal method using precursor tetrabutyl titanate. The Pd/TiO₂/C catalyst was synthesized by liquid phase reducing method supported on nano TiO₂ and Vulcan carbon XC-72. The Pd/TiO₂/C catalyst was characterized by XRD, TEM, cyclic voltammetry, and chronopotentiometry. XRD confirmed the face-centered cubic structure of Pd particles, and TEM indicated that Pd particles (size 3 ~ 4 nm) dispersed uniformly on TiO₂ and carbon XC-72. The results from cyclic voltammogram and chronopotentiogram showed the higher ethanol oxidation activity and stability of Pd/TiO₂/C catalyst (20% Pd) as compared with …

Electrochemical Oxidation Of Ammonium Nitrite In Absorption Solution Of Flue Gas, Yong-Hong Lu, Xiao-Bo Dong, Li-Sha Wang, Yan Liu, Chen-Jian Zhu, Hai-Bo Xu

Journal of Electrochemistry

In order to make full uses of ammonium nitrite in absorption solution from flue gas simultaneous desulfurization, denitrification and demercurization processes, here the electrochemical oxidation method was used to transform ammonium nitrite into ammonium nitrate. By using polarization curve, cyclic voltammogram and galvanostatic methods, suitable electrode materials were evaluated and chosen. The influence of electrolyte composition was discussed and the appropriate process parameters were obtained. Finally, the effect of electrochemical oxidation was confirmed by chemical analysis method. In 0.05 mol·L^-1 NaNO₂ + 0.05 mol·L^-1 (NH₄)₂SO₄ simulated absorption solution (5 L, pH = …