Engineering Commons^™

Influence Of The Temperature On Flow-Induced Crystallization Of Isotactic Polypropylene And Propylene–Ethylene Random Copolymer, Hugo Boitout

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

When flow is applied on a semi-crystalline polymer melt, it can greatly impact how it crystallizes its final properties. Therefore, it is crucial to understand the basic mechanism of flow induced crystallization (FIC). Only then will it be possible to predict final properties from the type of resin and processing conditions. Polypropylene is one of the most widely used polymers. Its processing generally involves subjecting the melt to intense flow fields, so FIC commonly occurs.

This study investigates the influence of temperature of shear and crystallization on the FIC behavior of isotactic polypropylene (iPP). Temperature is one of the main …

Design Of Gan-Based Low-Loss Y-Branch Power Splitter, Retno Wigajatri Purnamaningsih, Irma Saraswati, Nji Raden Poespawati, Elhadj Dogheche

Makara Journal of Technology

We present a Y-branch power splitter design with a multimode section using GaN on Sapphire at telecommunication wavelength. The GaN sample optical properties were also investigated, resulting in a refractive index for the GaN layers nTE=2.289±0.001 and nTM=2.324±0.00. Optimization of the structure parameters for this structure was conducted accurately using BPM methods. The results demonstrated the possibility of realizing a GaN-based Y-branch power splitter for various applications.

Ultra-Wideband Notched Characteristic Fed By Coplanar Waveguide, Rastanto Hadinegoro, Yuli Kurnia Ningsih, Indra Surjati

Makara Journal of Technology

In this paper, a novel Ultra-Wide Band (UWB) notch patch antenna with co-planar waveguide (CPW) fed is presented. This antenna only used one layer and the patch antenna is constructed on the first layer and back to back with CPW fed and bottom part is ground plane. The width notch is used to achieve the UWB characteristic. The results shown that the impedance bandwidth is 1130 MHz (1.662–2.792 GHz) or about 50.7% for VSWR <2.

Development Of The Soekarno–Hatta International Airport Rail Link Project Using The Value Engineering Method: Creating Value For Money, Mohammed Ali Berawi, Bambang Susantono, Suyono Dikun, Tommy Ilyas, Herawati Zetha Rahman, Abdur Rohim Boy Berawi, Teuku Yuri Zagloel, Perdana Miraj, Jade Sjafrecia Petroceany

Makara Journal of Technology

Soekarno–Hatta Airport is the main gateway for international flights to Greater Jakarta. Its accessibility depends on the inter-city and Sedyatmo toll roads, which causes congestion in peak hours, leading to uncertainty about travel times. The Soekarno–Hatta International Airport Rail Link (SHIARL) is proposed as an alternative mass transportation project, which is expected to provide accessibility and mobility for people and goods to and from the airport. Previously, the project was unattractive to private investors as it was technically and financially unfeasible. Therefore, this research aims to improve the feasibility of the Soekarno-Hatta International Airport Rail Link (SHIARL) by using a …

The Mechanical And Tribology Properties Of Sputtered Titanium Aluminum Nitride Coating On The Tungsten Carbide Insert Tool In The Dry Turning Of Tool Steel, Esmar Budi, Mohd. Razali Bin Muhamad, Md. Nizam Bin Abdul Rahman

Makara Journal of Technology

The effect of the sputtering parameters on the mechanical tribology properties of Titanium Aluminum Nitride coating on the tungsten cabide insert tool in the dry turning of tool steel has been investigated. The coating was deposited using a Direct Current magnetron sputtering system with various substrate biases (-79 to -221 V) and nitrogen flow rates (30 to 72 sccm). The dry turning test was carried out on a Computer Numeric Code machine using an optimum cutting parameter setting. The results show that the lowest flank wear (~0.4 mm) was achieved using a Titanium Aluminum Nitride-coated tool that was deposited at …

Continuous Production Of Nanotubes And Carbon Clusters By Use Of The Revolver-Injection-Type Arc Jet Producer, Tetsu Mieno, Naoki Matsumoto, Takahashi Tomie, H. Inoue

Makara Journal of Technology

Efficient and continuous production of fullerenes, single-walled carbon nanotubes (SWNTs), and carbon nano-particles has been developed by the JxB arc jet method, where the Lorentz force of magnetic field jets out gaseous carbon particles to the JxB direction. In order to realize continuous mass production of these carbon clusters, the revolverinjection- type arc jet producer (RIT-AJP) has been developed. Production of fullerenes, endohedral metallo-fullerenes, SWNTs, metal-encapsulated carbon nano particles has been examined.

Analysis Of Vibration Generated By The Rubbing Of Flat Surfaces, Zahrul Fuadi

Makara Journal of Technology

Among the phenomena that occur as a result of contact between two surfaces is friction sound, in which surface roughness is of great importance. In this study, the parameter of contact stiffness is used to explain the frequency characteristic of vibration generated by the rubbing of flat surfaces under a small load. A 3-disk configuration rubbing method was used, which provides a unique characteristic of the system's frequency response function containing specific information about the rubbing vibrations. It is shown that the peak frequency of the rubbing vibration can be explained by using a two-degrees-of-freedom model incorporating the parameter of …

Modified Design Of Pin-On-Ring Tribometer For Hip Joint Prostheses Measurement; Case Study On Salat Activity, Muhammad Khafidh, Jamari Jamari, Sulardjaka Sulardjaka, Mohamad Tauviqirrahman, Emile Van Der Heide

Makara Journal of Technology

Total hip replacement (THR) is one of the most successful orthopedic surgical procedures for replacing a broken hip joint. In THR, wear may occur at the articulating surface of the acetabular cup and the femoral head. In Indonesia, the country with the largest Muslim population in the world, most of the inhabitants do salat (praying) every day. THR users are banned from doing salat for fear it will damage the hip joint prostheses. The previous wear calculation methods on the hip joint prostheses use the gravimetric, coordinate measuring machine (CMM), profiler, and geometric method. The disadvantages of the previous methods …

Endoscopic Application Of A Compact Compound-Eye Camera, Keiichiro Kagawa, Shoji Kawahito

Makara Journal of Technology

A multi-functional compound-eye endoscope enabling multi-spectral imaging and variable field-of-view is presented, which is based on a compact compound-eye camera called TOMBO (thin observation module by bound optics). Narrow-band filters attached to some lenses provide snap-shot multi-band images. Fixed and movable mirrors are introduced to control the field of view, which realizes several observation modes such as three-dimensional shape measurement, wide field-of-view, and close-up observation.

Lateral Load Resistance Of Laminated Veneer Lumber Sengonwooden Joints With Wooden Dowels, Niken Palaeowati, Ali Awaludin, Suprapto Siswosukarto

Makara Journal of Technology

Analytical models for wooden-doweled joints need to be developed. The objective of this research is to determine whether the strength of wooden-doweled joints can be well predicted by equations developed for steel-doweled joints. In this experiment, various connection parameters, such as dowel diameter, species of the wooden dowel, and angle of joints, are studied. The joint specimens are loaded in a quasi-static state with four replications each. A5% offset diameter method is used to determine the lateral load resistance of the tested joints, while the predictions are evaluated by equations given in Indonesian National Standard (SNI) 7973-2013 and the European …

Influence Of Hot-Dip Coatings On Mechanical And Corrosion Behaviors Of Steel Bolts, Thanit Kenhong, Gobboon Lothongkum, Yuttanant Boonyongmaneerat

Journal of Metals, Materials and Minerals

Steel is the main type of materials used in construction applications. Steel bolt, in particular, is used for fastening all the structural components together, and hence high durability in terms of the mechanical and corrosion resistance is inevitably critical. Carbon steel shows adequate mechanical strength, yet it is highly susceptible to corrosion. On the other hand, stainless steel is praised for its remarkable corrosion resistance, yet its relatively low yield stress exhibits a drawback. Hot-dip coating which provides Fe-Zn or Zn-Ni compounds in the coating interface could potentially mitigate the shortcomings of carbon steel and stainless steel by providing improved …

Structural Characterization Of Iron Oxides And Hydroxides In The Clay Fraction Of Soil From The Inca Civilization Moray Terraces, Maria Luisa Ceron Loayza, Jorge Aurelio Bravo Cabrejos, Felipe Americo Reyes Navarro, Rosio Ascuna Arcondo

Journal of Metals, Materials and Minerals

We introduce the structural characterization of the iron oxides and hydroxides in the clay fraction from soil collected in Moray terraces, Peru. It is important since these terraces are considered as a major technological advancement in agriculture in Inca Civilization times. We utilized the following: techniques of selective dissolution by dithionite-citrate-bicarbonate (DCB) and sodium hydroxide (NaOH); analytical techniques of X-ray diffractometry (XRD); and transmission Msbauer spectroscopy (TMS). XRD of the untreated samples showed that all the terraces contain quartz and calcite. After a treatment with NaOH and DCB, the peaks from quartz kept defined; XRD analysis shows a well-crystallized Fe3+ …

Study And Manipulation Of Electron Tunneling Through Quantum Dots, Pradeep Krishna Bhadrachalam

Material Science and Engineering Dissertations - Archive

Fermi-Dirac distribution is the fundamental property which governs the electron energy distribution in solids. At finite temperatures, Fermi-Dirac thermal smearing of electron energies limits the operation of many electronic, opto-electronic and spintronic devices. Examples include single electron transistors, quantum dot resonant tunnel diodes for single photon detection, and single electron turnstile devices. To overcome this intrinsic limitation of Fermi-Dirac thermal smearing, these devices have typically been operated at cryogenic temperatures. Room temperature operation of these devices could be realized, however, if the thermal smearing of electron energies could be suppressed. Until now, studies in the fields of electron-tunneling refrigerators and …

Temperature-Dependence Of Stress-Related Phenomena, Rahmat Saptono

Material Science and Engineering Dissertations - Archive

Efforts have been made to develop a simple but physically sound model. The model was specifically proposed to capture, explain, and estimate the temperature sensitivity and strengthening mechanism phenomena in small volume material with particular reference to the roles grain boundary and surface. Model-inspired phenomenology approach was applied to reveal the key mechanisms and find directions for a more complete constitutive model. The model was developed in the limited space where diffusion is insignificant. It was assumed that the plastic flow was predominantly governed by the thermally-activated process of dislocation glide overcoming barriers. Simple mathematical functions were formulated and evaluated …

Experimental And Numerical Study Of Phase Transition Of Lifepo₄ Material In Lithium Ion Batteries, Md Noor E Alam Siddique

Material Science and Engineering Dissertations - Archive

Phase transition behavior of LiFePO4 material has been studied in this work. During electrochemical charge/discharge processes, LiFePO4 transforms into FePO4 and this electrochemically driven phase transition of the two-phase system results in a potential plateau in a battery discharge curve. Besides, battery performance, especially under high rates, depends critically on this two-phase transition. However, this phase transition mechanism in the LiFePO4 crystal structure has yet not been understood in details. Developing better understanding is essential for designing high performing, safe and stable batteries.Currently available phase transition models for LiFePO4, such as the classical `core-shrinking model' and recently the `domino cascade …

Early-Age Hydration Studies Of Portland Cement, Fengjuan Liu

Electronic Theses and Dissertations

Our current knowledge on cement hydration during setting is based on the discrete observation of hydrated paste. An advanced micro/nano-level technique which can perform the in-situ observation on the continuous hydration of cement paste is demanded. In this study, Raman spectroscopy (RS) was chosen as such a method to continuously investigate wet pastes. The objective of this research is to explore the hydration process and microstructural development of fresh pastes with this technique. This research was conducted in three phases. First, the RS analysis was used to continuously observe the cement hydration from 20 minutes after mixing to 9 hours. …

Slow Strain Rate Testing And Stress Corrosion Cracking Of Ultra-Fine Grained And Conventional Al–Mg Alloy, Mala M. Sharma, Josh D. Tomedi, Timothy J. Weigley

Faculty Journal Articles

Stress corrosion cracking susceptibility was investigated for an ultra-fine grained (UFG) Al–7.5Mg alloy and a conventional 5083 H111 alloy in natural seawater using slow strain rate testing (SSRT) at very slow strain rates between 1E⁻⁵ s⁻¹, 1E⁻⁶ s⁻¹ and 1E⁻⁷ s⁻¹. The UFG Al–7.5Mg alloy was produced by cryomilling, while the 5083 H111 alloy is considered as a wrought manufactured product. The response of tensile properties to strain rate was analyzed and compared. Negative strain rate sensitivity was observed for both materials in terms of the elongation to failure. However, the UFG …

Performance Analysis Of A Hybrid Raman Optical Parametric Amplifier In The O- And E-Bands For Cwdm Pons, Sasanthi Peiris, Nicolas Madamopoulos, Neophytos A. Antoniades, Dwight Richards, Roger Dorsinville

Publications and Research

We describe a hybrid Raman-optical parametric amplifier (HROPA) operating at the O- and E-bands and designed for coarse wavelength division multiplexed (CWDM) passive optical networks (PONs). We present the mathematical model and simulation results for the optimization of this HROPA design. Our analysis shows that separating the two amplification processes allows for optimization of each one separately, e.g., proper selection of pump optical powers and wavelengths to achieve maximum gain bandwidth and low gain ripple. Furthermore, we show that the proper design of optical filters incorporated in the HROPA architecture can suppress idlers generated during the OPA process, as well …

Corrosion Behaviour Of High Phosphorus Containing Cu-Cr Weather Resistant Steel, Gadadhar Sahoo, Anjana Deva, Balbir Singh, Atul Sexena

Journal of Metals, Materials and Minerals

Three steels viz., G22(Fe-0.072C-0.028 Si-0.20Mn-0.19P-0.38Cr-0.24Cu-0.17Ni), G32(Fe-0.072C-0.061 Si-0.23 Mn-0.19P-0.64Cr-0.14Cu) and SCOR (Fe-0.09C-0.37Si-0.42Mn-0.15P-0.37Cr-0.35Cu-0.31Ni) were made through ingot metallurgy route and hot rolled to 3 mm thick sheets. For other steels, similar corrosion rates were observed from the Tafel extrapolation study of freshly ground samples in 3.5% NaCl solution. Other technique employed to evaluate the effect of phosphorus on the formation of protective rust layer was electrochemical impedance spectroscopy (EIS) test after exposing the samples in an atmospheric exposure rack for four months on the roof top of a fourth floored building. Results revealed that the polarization resistance or rust resistance of G22 …

Effects Of Poly(Butylene Succinate) And Calcium Carbonate On The Physical Properties Of Plasticized Poly(Vinyl Chloride), Saowaroj Chuayjuljit, Phasawat Chaiwutthinan, Sitthipong Samutthong, Onusa Saravari, Anyaporn Boonmahitthisud

Journal of Metals, Materials and Minerals

In this studypoly(butylene succinate) (PBS) , a polymeric plasticizer, was partially replaced a conventional plasticizer, diisononyl phthalate (DINP) to avoid the plasticizer loss from poly(vinyl chloride) (PVC) overtime for various service conditions and to obtain a long-term plasticizer retention in the flexible PVC products. The plasticized PVC samples were prepared by melt mixing on a two roll mill, followed by compression molding. The mechanical properties (tensile properties, tear strength and hardness), thermal stability and morphology of the 20/20 phr (parts by weight per hundred parts of resin) DINP/PBS-plasticized PVC were evaluated and compared with those of the 40 phr DINP-plasticized …

Microstructural Development Of Galvanized Steels Prepared With Ni-P Electroless Deposited Pre-Coatings, Chulaluk Somphotch, Suparoek Henpraserttae, Ekasit Nisarattanaporn, Yuttanant Boonyongmaneerat

Journal of Metals, Materials and Minerals

An electroless pre-coating process is investigated as a possible method to prevent the sandelin effect, whereby steels containing silicon reacts rapidly with zinc during galvanization. From the microstructural and kinetics analysis, it is found that nickel-phosphorus electroless pre-coatings effectively serve as barriers to the reaction between Fe and Zn during galvanization, regardless of the silicon content in the steel substrates. Correspondingly, the coating thickness of the galvanized steels can be well-controlled.

Synthesis Of Porous Silica By Co-Micelle Emulsion Ternplating Technique Using Peg/Acrylamide And 2-(Acryloyloxy)-N,N,N-Trimethylethanaminium Chloride/Acrylamide As Templates, Iman Abdullah, Widyastuti Samadi, Arvinda Widyana, David Chandra Pandapotan, Ridla Bakri

Journal of Metals, Materials and Minerals

Co-micelle emulsion templating (co-MET) technique is a new method to synthesize uniform and ordered porous silica from tetraethylortosilicate precursor using double polymer as templates. In this study, co-MET technique was conducted by varying template type (namely PEG/acrylamide and 2(acryloyloxy)N,N,Ntrimethylethanaminium chloride/acrylamide) and percentage of polymer (2.5%, 5%, 10%, 15% and 20% for PEG and 0.5%, 1%, 2.5%, 5%, 10% for 2(acryloyloxy)N,N,Ntrimethylethanaminium chloride). The resulting porous silica were then characterized by SEM-EDS, BET and XRD to investigates the pore character and structure of silica. Based on SEM-EDS and BET analysis, it is shown that the amount and the type of polymer gave …

Mechanical Properties Of Poly(Lactic Acid) Composites Reinforced With Microfibrillated Cellulose Prepared Using High Speed Blending, Supachok Tanpichai, Jatuphorn Wootthikanokkhan

Journal of Metals, Materials and Minerals

Bamboo fibers, as a raw cellulose source, were used to prepare microfibrillated cellulose (MFC) using a high speed blender at 20,000 rpm for 60 min. Nanofibers with the width of less than 100 nm were disintegrated from the fibers. MFC networks were then prepared, and embedded in poly(lactic acid) resin using a compression molding at temperature of 180 C and a pressure of 10 MPa. Mechanical properties of poly(lactic acid) composites reinforced with MFC were investigated. The interaction between MFC fibrils and PLA resin was observed. As a result, Youngs modulus and tensile strength of the composites increased to 3.1 …

Printing Functional Electronic Circuits And Components, Ahmed Tausif Aijazi

Dissertations

The purpose of this study was to investigate the challenges in printing reliable multilayer flexible circuits, devices and components. Gravure was used as the primary printing process for this work, but due to some limitations of gravure, other printing methods were also investigated. At first a systematic study was done to determine the optimum parameters for the gravure printing of sub 50 micron lines. Commercially available silver nanoparticle inks were printed on a lab scale gravure printer, Accupress®. The highest resolution line that was electrically conductive was 36μm wide. The 9μm, 18μm and 27μm lines were printed but were not …

Investigation Of Fatigue Life And Fracture Mechanics Of Unconstrained Ni-Mn-Ga Single Crystals, Theodore Bryson Lawrence

Boise State University Theses and Dissertations

Ni-Mn-Ga is a magnetic shape memory alloy (MSMA) that exhibits large recoverable strains. The magnetic field induced strain (MFIS) occurs through twin boundary motion resulting in reorientation of the crystal structure, which is coupled to the magnetic moment of the material. The shape memory capabilities of the material make it promising for applications including microactuators, sensors, microfluid pumps, refrigeration, energy harvesting, and data storage.

In order for Ni-Mn-Ga to become a viable option for use in commercial applications the performance and reliability must be on par with industry standards. Ni‑Mn-Ga has been shown to achieve high cycles at low strains, …

Fatigue Damage Prognosis Of Internal Delamination In Composite Plates Under Cyclic Compression Loadings Using Affine Arithmetic As Uncertainty Propagation Tool, Audrey J-M Gbaguidi

Doctoral Dissertations and Master's Theses

Structural health monitoring (SHM) has become indispensable for reducing maintenance costs and increasing the in-service capacity of a structure. The increased use of lightweight composite materials in aircraft structures drastically increased the effects of fatigue induced damage on their critical structural components and thus the necessity to predict the remaining life of those components. Damage prognosis, one of the least investigated fields in SHM, uses the current damage state of the system to forecast its future performance by estimating the expected loading environments. A successful damage prediction model requires the integration of technologies in areas like measurements, materials science, mechanics …

Composite Films With Magnetic Nanorods: Fundamentals, Processing And Applications, Yu Gu

All Dissertations

This Dissertation is centered on studying the composite films with magnetic nanorods. In recent years, one-dimensional magnetic nanostructures, such as magnetic nanorods, chains of magnetic nanoparticles, and nanotubes filled with magnetic nanoparticles have caught great attentions due to the breadth of applications. Their unique magnetic and geometrical features open new avenues of studies in medicine, sensors, optofluidics, magnetic swimming, and microrheology. In particular, they offered great opportunities for design of multifunctional devices and for manufacturing of anisotropic nano- and microstructures with unprecedented magnetic and mechanical properties. However, the strategy for nanorod alignment in both Newtonian and complex fluids has not …

Earth Abundant Thin Film Technology For Next Generation Photovoltaic Modules, Githin Alapatt

All Dissertations

With a cumulative generation capacity of over 100 GW, Photovoltaics (PV) technology is uniquely poised to become increasingly popular in the coming decades. Although, several breakthroughs have propelled PV technology, it accounts for only less than 1% of the energy produced worldwide. This aspect of the PV technology is primarily due to the somewhat high cost per watt, which is dependent on the efficiency of the PV cells as well as the cost of manufacturing and installing them. Currently, the efficiency of the PV conversion process is limited to about 25% for commercial terrestrial cells; improving this efficiency can increase …

Synthesis And Characterization Of Chemically Functionalized Shape Memory Nanofoams For Unattended Sensing Applications, Anna Paola Soliani

All Dissertations

The work in this dissertation is devoted to the synthesis and characterization of novel materials for off-line unattended sensing: shape-memory grafted nanofoams. The fabrication process and characterization of highly efficient, polymeric nanosensor element with the ability to selectively detect analytes and retain memory of specific exposure events is reported. These shape memory nanofoams could potentially act as efficient and highly sensitive coatings for evanescent waveguide-based optical monitoring systems. On exposure to specific analytes, the polymeric coatings locally change their internal structure irreversibly at the nanolevel, affecting the local optical properties such as refractive index. Currently, enrichment polymer layers (EPLs) are …

Effect Of Styrene-Methyl Methacrylate/Styrene-Butadiene Rubber On Properties Of Poly(Vinyl Chloride), Buranin Saengiet, Fuangfa Unob, Kawee Srikulkit

Journal of Metals, Materials and Minerals

Generally, poly(vinyl chloride) (PVC) without the addition of plasticizer or impact modifiers is rigid and brittle. The aim of this research was to improve the mechanical properties of PVC using styrene-methyl methacrylate/styrene-butadiene compound (SMMA/SBR rubber) as an impact modifier. The compound was obtained commercially. PVC containing SMMA/SBR rubber having SMMA/SBR phrs of 2.5, 5, 7.5 and 10 were prepared using two-roll mill set the conditions as follows: 170 oC and 5 min. Then, compression molding was carried out to prepare testing samples. FTIR analysis of SMMA/SBR rubber containing PVC samples showed the absorption band at 1732 cm-1 (C=O stretching), 3025 …