Chemical Engineering Commons^™

Corrosion Rate Of Carbon Steel For Flowline And Pipeline As Transmission Pipe In Natural Gas Production With Co2 Content, Andi Rustandi, Muhammad Adyutatama, Enriko Fadly, Norman Subekti

Makara Journal of Technology

The purpose of this research is to investigate the corrosion rate of carbon steel as flowline and pipeline in natural gas production with CO2 content. The influence of variety of conditions that represent the actual conditions in practice such as CO2 partial pressure and solution composition, particularly NaCl percentage were performed. Research conducted by polarization test and simulation methods using PREDICTTM software. The result of this research is used to illustrate the level of corrosion rate of typical carbon steel i.e. API 5L X-52 occurred in natural gas pipelines due to the effect of dissolved CO2. From the experiments obtained …

Airlift Column Photobioreactors For Porphyridium Sp. Culturing: Part I. Effects Of Hydrodynamics And Reactor Geometry, Hu Ping Luo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Photosynthetic Microorganisms Have Been Attracting World Attention for their Great Potential as Renewable Energy Sources in Recent Years. Cost Effective Production in Large Scale, However, remains a Major Challenge to overcome. It is Known to the Field that Turbulence Could Help Improving the Performance of Photobioreactors Due to the So-Called Flashing Light Effects. Better Understanding of the Multiphase Fluid Dynamics and the Irradiance Distribution Inside the Reactor that Cause the Flashing Light Effects, as Well as Quantifying their Impacts on the Reactor Performance, Thus, Are Crucial for Successful Design and Scale-Up of Photobioreactors. in This Study, a Species of Red …

Modification Of Flow Structure Over A Van Model By Suction Flow Control To Reduce Aerodynamics Drag, Harinaldi Harinaldi, Budiarso Budiarso, Warjito Warjito, Engkos Achmad Kosasih, Rustan Tarakka, Sabar Pangihutan Simanungkalit, I Gusti Made Fredy Lay Teryanto

Makara Journal of Technology

Automobile aerodynamic studies are typically undertaken to improve safety and increase fuel efficiency as well as to find new innovation in automobile technology to deal with the problem of energy crisis and global warming. Some car companies have the objective to develop control solutions that enable to reduce the aerodynamic drag of vehicle and significant modification progress is still possible by reducing the mass, rolling friction or aerodynamic drag. Some flow control method provides the possibility to modify the flow separation to reduce the development of the swirling structures around the vehicle. In this study, a family van is modeled …

Age, Gender, And Muscle Strength: A Study Based On Indonesian Samples, Henny Henny, Hardianto Iridiastadi, Iftikar Zahedi Sutalaksana

Makara Journal of Technology

Age and gender have been commonly used as a main criterion in accepting a job aplicant, but it is usually not clear how these affect job performance. While a number of recent studies have been done that describe the relationships between age, gender, and participants capacity (e.g., muscle strength), the results have been inconclusive. In Indonesia, in particular, such issues have been rarely investigated, and it is still important to study the issue since the relationships between these factors are population-specific. This study aimed at describing the relationships between age and muscle strength among workers for both genders. Ninety-six male …

Circularly Polarized Microstrip Array Antenna For Ground Segment In Quasi-Zenith Satellite System, Fitri Yuli Zulkifli, Eko Tjipto Rahardjo

Makara Journal of Technology

In satellite communication system, antenna plays an important role. Therefore, the antenna must meet some requirements, such as high gain, circular polarization, and good directivity. In this paper, a four element linear array triangular patch microstrip antenna with cross slot is designed to be used for Quasi-Zenith satellite system. A simulation study as well as experimental study was carried out. The simulation showed that the 3 dB axial ratio bandwidth of 87 MHz (2.569-2.656 GHz) is achieved while the measured results showed 96 MHz (2.556-2.652 GHz). The linear array of 4 element antenna has a gain of 13.73 dB and …

Electrochemical Deposition Of Ag-Sn Nanoparticles For Photovoltaic Current Collection Efficiency, Rebecca Wilson

Honors Theses and Capstones

Photovoltaic cells utilize a semiconductor to harness the sun's energy, then conduct the energy by silver current collector lines to an energy storage device. To make photovoltaic cells less expensive and more energy efficient, silver-tin nanoparticles were researched to incorporate into the silver polymer paste that makes up current collector lines. The Ag-Sn alloy was synthesized by electrochemical deposition, and was then characterized by it's melting point and crystal structure.

Supercritical Co2 Extraction Of Oil From Henna Flower: Experimental, Mathematical Modeling, And Antioxidant Activity, Bushra Saeed Mohammed Dohai

Theses

Henna is a plant that has been used traditionally for coloring nail, skin, and hair, and as medicinal plant. The supercritical fluid technology offers a considerable promise as extraction media due to its advantages over other conventional extraction techniques. The extraction of volatile components from flowers of henna was studied using supercritical carbon dioxide at temperatures and pressures ranging from 35 to 55°C and 80 to 120 bar, respectively. A maximum extraction yield of 31 % from 2g of henna flowers was obtained at 45 °C and 120 bar. The composition of the extracts was investigated by gas chromatography technique. …

Concurrent Engineering Of Tolerance Synthesis And Process Selection For Products With Multiple Quality Characteristcs Considering Process Capability, Mohamad Imron Mustajib

Makara Journal of Technology

The existences of variances that are very difficult to be removed from manufacturing processes provide significance of tolerance to the product quality characteristics target of customer functional requirement. Furthermore, quality loss incurred due to deviation of quality characteristics of the target with a specified tolerance. This article discusses the development of concurrent engineering optimization model of tolerance design and manufacturing process selection on product with multiple quality characteristics by minimizing total costs in the system, namely total manufacturing cost and quality loss cost as functions of tolerance, also rework and scrap costs. The considered multiple quality characteristics have interrelated tolerance …

Pineapple Liquid Waste As Nata De Pina Raw Material, Agus Sutanto

Makara Journal of Technology

This research aims to study the quantity, quality, ecological and economic feasibility of nata de pina production (NP) from pineapple liquid waste (PLW). The design of the study employs complete random design (CRD) with three treatments: PLW without nutrients addition (A), PLW nutrients addition (B), and PLW stored for six months with nutrients addition (C). The nata de pina’s production factors measured were weight, thickness, fiber content, color, brightness, and residual waste. The highest weight was reached in treatment B (899 grams), followed by treatment A (616.4 grams), and C (477.8 grams). The thickness of NP of the height and …

Modeling Of A New Structure Of Precision Air Conditioning System Using Secondary Condenser For Rh Regulation, Aries Subiantoro, Nasruddin Nasruddin, Feri Yusivar, Muhammad Idrus Al-Hamid, Bagio Budiardjo

Makara Journal of Technology

A dynamic mathematical model for a new structure of precision air conditioning (PAC) has been developed. The proposed PAC uses an additional secondary condenser for relative humidity regulation compared to a basic refrigeration system. The work mechanism for this system and a vapour-compression cycle process of the system are illustrated using psychrometric chart and pressure-enthalpy diagram. A non-linear system model is derived based on the conservation of mass and energy balance principles and then linearized at steady state operating point for developing a 8th-order state space model suited for multivariable controller design. The quality of linearized model is analyzed in …

Optimizing Fermentation Medium To Produce Cyclosporin A Using Response Surface Methodology, Rofiq Sunaryanto

Makara Journal of Technology

Response surface methodology (RSM) is a three factorial model which illustrates the relationship between one or more independent variables. RSM can be used to optimize the fermentation medium for the production of Cyclosporin A from the isolate Tolypocladium inflatum. The optimal point of the response surface area is predicted by using a seconddegree polynomial model and applying the statistic model obtained from the central composite design (CCD). The results of optimizing the fermentation medium for Cyclopsorin using the three independent variables of glucose, casein, and KH2PO4 show that all three of the independent variables affect the production of Cyclosporin A. …

Investigation And Synthesis Of Novel Graphene-Based Nanocomposites For Hydrogen Storage, Anthony Joseph D'Angelo

USF Tampa Graduate Theses and Dissertations

It is of great interest to develop and utilize a high surface area material with optimized hydrogen sorption properties. The need for a renewable energy source to replace automobile gasoline has become more critical in the past decade. Hydrogen is a viable fuel source for automobile usage; however, the question of how hydrogen will be safely and efficiently stored still remains. Critical factors for optimum hydrogen storage include ambient conditions and low activation temperature for adsorption and desorption phenomena. In order for optimum hydrogen adsorption to be achieved, the properties of (1) high surface area, (2) optimum hydrogen adsorption energy, …

Temperature Dependent Droplet Impact Dynamics On Flat And Textured Surfaces, Azar Alizadeh, Vaibhav Bahadur, Sheng Zhong, Wen Shang, Ri Li, James Ruud, Masako Yamada, Liehui Ge, Ali Dhinojwala, Manohar Sohal

College of Polymer Science and Polymer Engineering

Droplet impact dynamics determines the performance of surfaces used in many applications such as anti-icing, condensation, boiling, and heat transfer. We study impact dynamics of water droplets on surfaces with chemistry/texture ranging from hydrophilic to superhydrophobic and across a temperature range spanning below freezing to near boiling conditions. Droplet retraction shows very strong temperature dependence especially on hydrophilic surfaces; it is seen that lower substrate temperatures lead to lesser retraction. Physics-based analyses show that the increased viscosity associated with lower temperatures combined with an increased work of adhesion can explain the decreased retraction. The present findings serve as a starting …

Effect Of Platinum Particle Size On The Sulfur Deactivation Of Hydrogenation, Lyndsey Michelle Baldyga

USF Tampa Graduate Theses and Dissertations

A large concern of the fossil fuel and renewable energy industries is the sulfur poisoning of catalysts. In the case of noble metals, such as platinum, it is seen that there is a size trend associated with the level of activity in the presence of sulfur. Smaller nanoparticles could be more tolerant due to sulfur surface vacancies. On the other hand, larger particles could have less deactivation because the sulfur is more attracted to the smaller particles and the sulfur molecules bind stronger to these smaller particles.

The size effect of sulfur deactivation was investigated by testing four sizes of …

Biomedical Properties And Preparation Of Iron Oxide-Dextran Nanostructures By Maple Technique, Carmen Steluta Ciobanu, Simona Liliana Iconaru, Eniko Gyorgy, Mihaela Radu, Marieta Costache, Anca Dinischiotu, Philippe Le Coustumer, Khalid Lafdi, Daniela Predoi

Chemical and Materials Engineering Faculty Publications

Background: In this work the chemical structure of dextran-iron oxide thin films was reported. The films were obtained by MAPLE technique from composite targets containing 10 wt. % dextran with 1 and 5 wt.% iron oxide nanoparticles (IONPs). The IONPs were synthesized by co-precipitation method. A KrF* excimer laser source (λ = 248 nm, τFWHM≅25 ns, ν = 10 Hz) was used for the growth of the hybrid, iron oxide NPs-dextran thin films.

Results: Dextran coated iron oxide nanoparticles thin films were indexed into the spinel cubic lattice with a lattice parameter of 8.36 Å. The particle sized calculated was …

A Streamlined Strategy For Biohydrogen Production With Halanaerobium Hydrogeniformans, An Alkaliphilic Bacterium, Matthew B. Begemann, Melanie R. Mormile, Oliver C. Sitton, Judy D. Wall, Dwayne A. Elias

Biological Sciences Faculty Research & Creative Works

Biofuels are anticipated to enable a shift from fossil fuels for renewable transportation and manufacturing fuels, with biohydrogen considered attractive since it could offer the largest reduction of global carbon budgets. Currently, lignocellulosic biohydrogen production remains inefficient with pretreatments that are heavily fossil fuel-dependent. However, bacteria using alkali-treated biomass could streamline biofuel production while reducing costs and fossil fuel needs. An alkaliphilic bacterium, Halanaerobium hydrogeniformans, is described that is capable of biohydrogen production at levels rivaling neutrophilic strains, but at pH 11 and hypersaline conditions. H. hydrogeniformans ferments a variety of 5-and 6-carbon sugars derived from hemicellulose and cellulose …

Effects Of Adding Acid Plant Sulfur On Heap Leaching, Jibin George

Masters Theses and Doctoral Dissertations

Mining industry is heavily invested in mining various precious metals from their natural ore deposits. Copper ore deposits are found across the world and heap leaching of copper has been implemented effectively for years. The ore is broken down to copper ions and elemental sulfur in the heap. Acid plants are used in mines to replenish the raffinate leaching the heaps which consists of sulfuric acid. Molten sulfur carried in rail cars to the acid plant is often accidentally spilled on the ground. The contaminated sulfur cannot be added to the acid plant and has been disposed of as hazardous …

Synthesis And Electrochemical Performance Of Xlifepo4·Yli3V2(Po4)3 Composites, Ping-Ping Ma, Zhi-Jian Liu, Jian-Hua Xia, Yu Chen, Pu Hu, Zhi-Chao Lu, Ding-Guo Xia

Journal of Electrochemistry

A series of xLiFePO₄·yLi₃V₂(PO₄)₃ composites were systematically synthesized through solid state reactions by variations in the proportions of LiFePO₄ and Li₃V₂(PO₄)₃. The properties of the prepared compounds were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurements. The capacity of 162.7 mAh/g at 0.2 C rate was obtained with the relatively good cycle stability and good conductivity for 0.95LiFePO₄·0.05Li₃V₂(PO₄)₃ due to more uniformed distributed and smaller particle sizes.

Electrocatalytic Study Of Pseudomonas Aeruginosa Bte-1 Strain, Ping Zhou, En-Ren Zhang, Li Zhou, Guo-Wang Diao, Jun-Le Niu

Journal of Electrochemistry

The aim of the present study is to investigate the electrocatalytic activity of electricity-producing Pseudomonas aeruginosa BTE-1 strain under anaerobic conditions. Pseudomonas aeruginosa BTE-1 was inoculated into anaerobic three-electrode electrochemical cells, and the electrocatalytic activity was measured at poised potentials. HPLC and cyclic voltammetry were used to detect potential electron mediators in solutions. Experimental results showed that no detectable pyocyanine was excreted by P. aeruginosa BTE-1 strain in the anaerobic electrochemcial cells, and P. aeruginosa BTE-1 exhibited direct electrocatalytic activity through the formation of biofilm on the electrode surface which was induced by the electron transfer from the cells of …

Progress And Perspective Of Fuel Cell Technology, Ming Hou, Bao-Lian Yi

Journal of Electrochemistry

Fuel cell, a clean and high-efficiency electrochemical power source, has being paid much attention worldwide recent years. In this paper, the progress and perspective of fuel cell technology are elucidated in detail. Fuel cells have been applied in some special fields such as spacecraft, shuttle and submarines. However, in the areas of transportation, stationary station and portable power source, fuel cells are still under demonstration due to the durability and cost problems. The reliability and surrounding survivability of fuel cells should be enhanced in the special application. Meanwhile, the durability and cost of fuel cells are the main issues to …