Engineering Commons^™

A 2.3/3.3-Ghz Dual Band Low Noise Amplifier Using Switchable Load Inductor In 0.18-Um Cmos Technology, Taufiq Alif Kurniawan, Hsiao-Chin Chen

Makara Journal of Technology

In this paper, the dual band low noise amplifier is designed in 0.18-μm CMOS technology. By combining the proposed switchable load inductor for gain controlling and the conventional inductive source degeneration topology, narrow band gain and good impedance matching are achieved at 2.3/3.3-GHz frequency bands. The new mathematical analysis of low noise amplifier design is derived to define the component parameters of the proposed circuits. The proposed low noise amplifier exhibits gain of 17.18 dB and 15.5 dB, and noise figure of 2.67 dB and 2.52 dB at the two frequency bands, respectively.

Ascorbic Acid Degradation In Cut Lemon Packaged Using Oxygen Scavenging Active Film During Storage, Kurniawan Yuniarto, Setyo Purwanto, Bruce Ari Welt, Anang Lastriyanto

Makara Journal of Technology

Oxygen scavenging active film can be used to prevent diffusion of free oxygen due to the action of permeation mechanism. In this study, biodegradable oxygen scavenging plastic film was designed by incorporating an antioxidant agent into plasticized polylactic acid or PLA-PEG (PPLA). Butylated hydroxytoluene (BHT) was added at different concentrations into the matrix of the PPLA film using a direct casting method to produce oxygen scavenging active film. The antiradical activity of the oxygen scavenging active film was observed, which could be applied for preventing vitamin C degradation in cut lemon during storage. The antiradical activity of the active film …

The Importance Of Usability Aspect In M-Commerce Application For Satisfaction And Continuance Intention, Yassierli Yassierli, Vinsensius Vinsensius, M. S. Syed Mohamed

Makara Journal of Technology

There has been a rapid growing of m-commerce application in recent years due to the development of mobile communication technology and e-commerce business. However, only about 30% of online users, who conduct online searching, make online purchases. The low conversion rate seems to be correlated with poor usability aspect of most m-commerce applications and poor satisfaction reported by users. Research has reported that satisfaction and continuance intention in using m-commerce applications have relationships with service quality and information quality. In this study, a new model of user satisfaction and continuance intention in the context of mobile application was proposed by …

Developing A Non-Cooperative Optimization Model For Water And Crop Area Allocation Based On Leader-Follower Game, Abbas Sedghamiz, Mohammad Reza Nikoo, Manouchehr Heidarpour, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

In this paper, a mathematical model for conflict resolution among a diverse set of agricultural water users in Golestan province, Iran, is developed. Given the bi-level nature of the distribution of power in the current problem, a combination of Leader–Follower game and Nash–Harsanyi bargaining solution method is employed to find optimal water and crop area allocations. The Golestan Regional Water Authority is the leader in this setting, controlling the total water allocations; and the agricultural sectors are the followers, competing over the allocated water. Two objectives for the leader are (i) maximizing profits, and (ii) maximizing share of green water …

A New Normal For Streamflow In California In A Warming Climate: Wetter Wet Seasons And Drier Dry Seasons, Iman Mallakpour, Mojtaba Sadegh, Amir Aghakouchak

Civil Engineering Faculty Publications and Presentations

In this study, we investigate changes in future streamflows in California using bias-corrected and routed streamflows derived from global climate model (GCM) simulations under representative concentration pathways (RCPs): RCP4.5 and RCP8.5. Unlike previous studies that have focused mainly on the mean streamflow, annual maxima or seasonality, we focus on projected changes across the distribution of streamflow and the underlying causes. We report opposing trends in the two tails of the future streamflow simulations: lower low flows and higher high flows with no change in the overall mean of future flows relative to the historical baseline (statistically significant at 0.05 level). …

Degradation Of 3-Nitro-1, 2, 4-Trizole-5-One (Nto) In Wastewater With Uv/H2o2 Oxidation, Amalia Terracciano, Christos Christodoulatos, Agamemnon Koutsospyros, Zhaoyu Zheng, Tsan-Liang Su, Benjamin Smolinski, Per Arienti, Xiaoguang Meng

Civil Engineering Faculty Publications

Insensitive Munition (IM) formulations contain 3-nitro-1,2,4-trizole-5-one (NTO), an energetic compound with the highest aqueous solubility (16 g L⁻¹) among all IM explosives, including 2,4-dinitroanisole (DNAN) and 1-nitroguanidine (NQ); as a result wastewater streams from IM processing facilities can be highly contaminated and potentially toxic. The removal of energetic compounds from wastewater streams prior to their discharge in the environment is imperative, and new technology must be developed to efficiently treat high levels of NTO and other IM compounds in these streams. In this study, the treatment of NTO wastewater by a UV/H₂O₂ oxidation process under …

Young’S Modulus As A Measurement To Estimate Damage Related With Alkali-Silica Reaction In Concrete., Anazaria J. Ortega Gonzalez

Civil Engineering Undergraduate Honors Theses

The main purpose of this research is to compare two nondestructive methods to assess Alkali-Silica reaction (ASR) in concrete. Fifteen concrete prisms were cast using aggregates with different Alkali-Silica reactivity such as Jobe sand and Van Buren sand. The change in strain, shear wave velocity and Young’s modulus were determined according to ASTM C129 and ASTM C215, respectively. This data was collected by Dillon K Self, who determined that the shear wave velocity and strain are inversely proportional. However, when single cracking in the concrete specimen transition to map cracking, the shear wave velocity dropped significantly, whereas the strain value …

Understanding Track Substructure Behavior: Field Instrumentation Data Analysis And Development Of Numerical Models, Huseyin Boler, Debakanta Mishra, Wenting Hou, Erol Tutumluer

Civil Engineering Faculty Publications and Presentations

Numerous studies have targeted using numerical modeling, field instrumentation, or combinations of both to gain insight into track substructure behavior under loading. In-depth understanding of track substructure behavior serving both passenger and freight trains is critical to developing suitable design and maintenance/rehabilitation methods to ensure adequate performance under loading. This manuscript presents findings from a recently completed study involving advanced instrumentation and numerical modeling to investigate track substructure-related issues at several problematic railroad bridge approaches in the United States. Multi-Depth Deflectometers (MDDs) were installed to measure transient as well as plastic deformations experienced by track substructure layers under loading. Strain …

Development Of Anti-Icing Airfield Heated Pavement Systems Using Solar Energy, Joseph Daniels

Graduate Theses and Dissertations

This dissertation analyzes developing and assessing the viability of an anti-icing airfield heated pavement system using solar energy. This study includes two components, a field experimentation component and a numerical analysis component. Field experimentation investigates two systems: (1) an electrical heated pavement system with a photovoltaic energy system as its power source, and (2) a hydronic heated pavement system with a solar water-heating system as its heating source. The systems operate under an automated thermostat heating sequence for operation optimization and energy conservation. Study results found the solar systems capable of supplying enough energy to maintain pavement surface temperature above …

Utilizing The Hvsr Second Peak For Surface Wave Inversions In The Mississippi Embayment, Ashraf Kamal Himel

Graduate Theses and Dissertations

Ambient noise data from 24 sites within the Mississippi Embayment were analyzed to estimate the fundamental frequency using the horizontal to vertical spectral ratio (HVSR) method. The fundamental frequency ranged from 0.17 to 3.43 Hz for the tested sites. At seventeen of the sites, a second higher frequency HVSR peak, which ranged from 0.617 Hz to 2.154 Hz, was observed in addition to the fundamental HVSR peak. The second peak frequency in the HVSR curve has been attributed by previous researchers as either an odd harmonic of the fundamental peak or a shallow impedance contrast from the Memphis sand layer …

Early Life Flexural Performance And Behavior Of Reinforced Bcsa Concrete Beams, Gabriel Cook

Graduate Theses and Dissertations

Belitic calcium sulfoaluminate cement (BCSA) is a hydraulic, rapid setting alternative to ordinary portland cement (OPC) with reduced energy demands and CO2 emissions. BCSA cement has numerous current and potential applications including transportation repair and precast manufacturing. Currently, limited research exists regarding the structural performance of CSA cements, restricting its potential implementation. Thus, the purpose of this research is to provide insight into the flexural performance and behavior of reinforced BCSA concrete beams. Overall, BCSA concrete had similar cracking and loading behavior to the OPC beams, with increased moment capacity for compression controlled specimens. Furthermore, BCSA concrete showed increased tensile …

Examining The Use Of Idealized Granular Material In Validated Dem Simulations, Anjana Thoroppady Kittu

Graduate Theses and Dissertations

Discrete element method (DEM) modeling, is becoming widely used for understanding the micro-mechanical behavior of granular materials at the particle level. This dissertation presents important considerations regarding the experimental boundary conditions and idealized granular materials used in DEM validations.

A common issue in DEM validation studies for direct shear and direct simple shear is selecting top and bottom cap boundary conditions that allow for shear transmission while also being efficiently modeled in the DEM simulations. While the traditional grid boundary types used in the laboratory can be replicated in the numerical models, researchers have also used fixed-particle boundaries, sawtooth boundaries, …

Fatigue Performance And Shear Demand Distributions Of Clustered Shear Connectors In Composite Bridge Girders, Brian David Hillhouse

Graduate Theses and Dissertations

The current American Association of State Highway and Transportation Officials (AASHTO) Bridge Specifications assumes uniform shear flow demands at the steel-concrete interface of composite bridge girders. As stud pitch increases to beyond 24 in or as studs become clustered to account for pre-cast concrete decks, this assumed shear demand distribution may be unrepresentative. Understanding shear transfer and resulting demands on headed studs in composite beams are important for ensuring adequate composite design. This study investigates stud demands in composite bridge girders using large-scale fatigue testing and direct pressure measurements for stud force calculations. In this study, two large-scale composite beam …

Accumulation Of Lead By Biofilms In Drinking Water Distribution Systems, Kaleb Oren Belcher

Graduate Theses and Dissertations

Recent crises, such as the one in Flint, MI, indicate that lead exposure from drinking water is a major health concern in the United States. Over six million lead service lines are still in use in the United States, and a universal protocol to safely remove these lead service lines from drinking water distribution systems has not yet been established. This paper calls to attention the potential hazard that biofilms pose as a source of lead in distribution systems, even after the removal of lead pipes. This study used a simulated water distribution system containing a lead source pipe and …

Developing Computer Codes For Analyzing Bridge Response Due To Wim Data Truck Loading, Kenneth Patrick Pasley

Graduate Theses and Dissertations

Despite actual truck demographics evolving over the past 30 years, the Arkansas legal loads for bridge posting have not been updated. Custom computer codes were developed.to facilitate comparison between the current Arkansas legal loads for bridge posting and the actual Arkansas truck traffic to ensure that actual reactions are enveloped by the state'. The program, WIMFluence, calculates shear and moment influence lines for a bridge and the resulting shear and moment reactions based on weigh-in-motion data. With supporting scripts, the reactions due to actual Arkansas truck traffic were compared to those due to the current Arkansas legal loads for bridge …

On The Development Of 8,000 Psi Geopolymer Mortar For Practical Use In Field Applications, Remington Gabriel Reed

Graduate Theses and Dissertations

Although there are several perceived benefits from the use of geopolymer binder as an alternative to ordinary portland cement in concrete materials, it is not widely used in field applications. Geopolymer materials have no set guidelines for mixture design and often require heat curing to facilitate strength gain. Additionally, many geopolymers are created using carefully controlled and high quality materials and activator chemicals. These factors greatly affect the practicality of the material. The goal of this research was to create a geopolymer material capable of achieving high compressive strengths at 28 days without heat curing, and using only readily available …

Developing Ultra-High Performance Concrete (Uhpc) With Locally Available Materials, Ali Alsalman

Graduate Theses and Dissertations

Ultra-High Performance Concrete (UHPC) can enhance the durability and resilience of concrete structures. The use of local materials is a fundamental step to save energy and reduce the cost of concrete. The main focus of this research was to develop a UHPC with compressive strength of 150 MPa using locally sources materials. In this study, the effect of fine materials, binder type and content, type of mixer, steel fibers and curing regimes on concrete’s compressive strength were investigated. The relationship between compressive strength and elastic modulus was also studied. This study synthesizes all relevant experimental data in the literature to …

Effect Of Continuity Plate Eccentricity On The Performance Of Welded Beam-To-Column Connections, Jason Thomas Norwood

Graduate Theses and Dissertations

Beam-to-column connections in structural steel buildings may have varying degrees of rotational restraint and varying degrees of moment transfer. In fully restrained moment connections, shear is typically transferred through the beam web, while the moment is mostly transferred through the beam flanges which create tension/compression force couples. Column sections that are incapable of resisting these flange forces are often retrofitted with continuity plates within the connection region to improve capacity. In cases of unequal beam depths on either side of the column, an eccentricity between the framed-in beam flange and continuity plate may be required; however, limited research exists to …

Effect Of Cement Content On Concrete Performance, Caleb Joshua Lebow

Graduate Theses and Dissertations

Of all the traditional concrete materials, portland cement has the greatest impact on mixture cost and the environment. Cement is in many ways the glue holding concrete together (Weiss, 1999), and as such, it plays a major role in fresh and hardened concrete properties. Without the proper range of cement in the mixture, low strength development or excessive shrinkage may occur leading to premature deterioration. The Arkansas Department of Transportation (ARDOT) recognizes two types of concrete for use in bridge construction, Class S and Class S(AE). This paper focuses on the findings from testing of Class S(AE) concrete, short for …

Utilizing 3d Printed Analogue Soils To Investigate Specimen Size Effects In Triaxial Testing, Claire Louise Stewart

Graduate Theses and Dissertations

Triaxial testing is one of the fundamental laboratory tests used in geotechnical engineering to determine strength parameters, such as shear strength and friction angle. Investigating the minimum representative elementary volume (REV) can verify the independence of size effects on strength parameters and ensure that the scaled laboratory tests results are consistent, repeatable, and representative of field conditions. Although, REV has been studied for many applications, there is disagreement within geotechnical engineering of a minimum particle diameter to specimen diameter to minimize the size effects related to the REV in consolidated drained (CD) triaxial tests. This research study compared the strength …

Laboratory And Field Study Of A Liquid Ionic Soil Stabilizer, Sandesh Gautam

Civil Engineering Theses - Archive

Chemical stabilization of expansive soil has been practiced for quite a time now. The use of lime/cement stabilization as a traditional method has been well acknowledged, understood and standard guidelines for practice have been developed. However, owing to certain demerits like high production and application cost, environmental impact, durability issues and most importantly incompatibility with high-sulfate soil leading to excessive heaving and swell, there is need to develop alternatives to these stabilizers. Non-traditional stabilizers like ionic soil stabilizer have been used by manufacturers in the past and claimed to effectively reduce the swell-shrink behavior of expansive soil. Undocumented results, the …

Structural Safety Of Bridge Decks With Variable Rebar Cover, Prem Egade

Civil Engineering Theses - Archive

Construction defects are common and are difficult to avoid completely. This arises due to improper workmanship, inspection, drawing and specification. On bridge decks, achieving the desired cover is necessary since inadequacy can cause accelerated corrosion in steel and for the most part spalling and delamination which ultimately led to failure. Tolerance provided by different standards and specification also restrict the amount of rebar. So, construction is more focused on increasing cover undermining the loss of strength as consequence. The objective of this research is to check the safety of decks by analyzing bridges for reduction in capacity due to cover …

Controlling Relative Humidity Using Glycerin, Juan Martinez

Civil Engineering Undergraduate Honors Theses

A series of tests were conducted to control relative humidity (RH) using a bubbler system that contained a series of glass jars and glass vials filled with different concentrations of glycerin. The relative humidity within the glass jars was measured. The total time interval for each laboratory test was 48 hours. During the first 24 hours a pump was used to bubble air through the glycerin solution. During the second 24 hours, the pump was turned off, and the RH within the system was monitored within the closed system. Target RH measurements from 100% to a 0% were obtained. The …

Methane Oxidation Potential Of Uncomposted Yard Waste As A Landfill Biocover, Gomathy Radhakrishna Iyer

Civil Engineering Dissertations - Archive

Biocovers are widely used in landfills to oxidize emissions of the greenhouse gas methane. Biocovers used till date are fully or partially made of composts. Compost takes time and effort to create, and costs about $10 per cubic yard on an average. Even more importantly, however, production of compost, although theoretically an aerobic process, actually generates methane, from 3.2 to 362 kg CO2-equivalents per ton of wet waste composted, depending on the type of waste, whether open or enclosed composting technology is used, and other factors. To reduce the net greenhouse gas emissions from biocovers, this research explores the potential …

Hpfrc And Rc Slab-Beam-Column Connections Under Extreme Earthquake Loading And Further Improvement Of Novel Double-Beam-Coupling Beams, Youngjae Choi

Civil Engineering Dissertations - Archive

The work presented in this dissertation is divided into two parts. Each part has drawn its own results. Reinforced concrete (RC) buildings resist a strong earthquake through structural foundations, diaphragms, and vertical elements. Moment-resisting frames and shear walls are primary-used vertical elements in RC buildings. The moment-resisting frames consist of columns, beams that frame into the column and beam column joints where the columns and beams meet. A key point of designing the moment-resisting frames against a strong earthquake is to ensure beam-column connections to dissipate as much energy possible. The shear wall often becomes two separate slender cantilever walls …

Novel Infrastructure Monitoring Using Multifaceted Unmanned Aerial Vehicle Systems - Close Range Photogrammetry (Uav - Crp) Data Analysis, Surya Sarat Chandra Congress

Civil Engineering Dissertations - Archive

Remote sensing is a method of collecting data without making any physical contact with the object under inspection. Modern day remote sensing kicked off with the invention of the camera and continued on to the invention of advanced satellite mounted sensors. Photogrammetry is defined as a science that measures distances using one or more images captured remotely. Remote collection of images within a range of 1000 ft is termed close-range photogrammetry (CRP). Unmanned aerial vehicle systems (UAV or UAS) have become a popular means of remotely gathering information and assessing infrastructure conditions due to their versatile nature. Multirotor and fixed-wing …

Utilization Of Geocell-Reinforced Rap Material Base Layer In Flexible Pavements: Experimental And Numerical Studies, Anu Muthumala George

Civil Engineering Dissertations - Archive

Reclaimed asphalt pavement (RAP) materials have been considered as one of the most sustainable and cost-effective options in the pavement industry. The use of RAP materials in pavement construction reduces natural resources depletion and the volume of construction debris discarded into the landfills. However, the low shear strength and high permanent deformation (PD) of RAP materials often limit their application in road bases. Utilization of mechanical stabilizers, such as geocell, for stabilizing RAP bases, have found to be effective in improving the pavement performance. The main objective of this study is to assess the efficacy of high-density polyethylene (HDPE) geocell …

Development Of The Urban Passenger Transportation Life Cycle Inventory For Comparison Across Modes Model (Transportlifecamm), Alma Angelica Hernandez Ruiz

Civil Engineering Dissertations - Archive

Against the backdrop of the increasingly complex urban passenger transportation challenges associated with megacities during the 21st century, and the effort to find the most sustainable modes of transportation for them, the spreadsheet-based model TransportLifeCAMM was developed. This model allows users in the US and Mexico to compare life cycle environmental impacts from automobile, bus, and/or subway. While other models to estimate environmental burdens from transportation exist, few of them consider emissions or energy consumption over the entire life cycle of the vehicle and the fuel (including vehicle manufacture, fuel production, maintenance, and end-of-life disposal). Furthermore, even fewer of the …

Post-Disaster Construction Labor Cost Fluctuations: Measurement And Modeling, Navid Ahmadi Esfahani

Civil Engineering Dissertations - Archive

The United States has been one of the top five countries most frequently hit by natural disasters. The post-disaster survival of cities and communities depend on their capabilities to reconstruct and repair damages to buildings and other infrastructure systems. The significant increase in the repair costs following large-scale natural disasters, also called “demand surge,” slows down the repair process that impacts many lives touched by large-scale natural disasters. Previous studies showed that post-disaster construction labor cost escalation drives the total post-disaster construction cost escalation in the U.S. The ultimate goal of this research is to (1) measure post-disaster construction labor …

Integrated Health Monitoring And Reinforcement Of Transportation Structures With Optimized Low-Cost Multifunctional Braided Cables, Ibrahim Karaman, Darren Hartl

Publications

The objective of this research study is to design, fabricate, and characterize multifunctional high strength and self-sensing braided cables and structures using novel Fe-based shape memory alloys (SMAs). The system exploits unique properties of recently developed low-cost super-elastic FeMnAlNi SMAs, which enables excellent super-elastic properties, high strength, and self-sensing in structural health monitoring (SHM) systems. This novel material technology can be coupled with modeling efforts that allow for accurate prediction of both the materials and structural response during sensing. At the conclusion of the project, we have demonstrated that with careful design of processing parameters, it is possible to control …