Engineering Commons^™

Mems Cantilever Sensor For Thz Photoacoustic Chemical Sensing And Spectroscopy, Nathan E. Glauvitz

Theses and Dissertations

Sensitive Microelectromechanical System (MEMS) cantilever designs were modeled, fabricated, and tested to measure the photoacoustic (PA) response of gasses to terahertz (THz) radiation. Surface and bulk micromachining technologies were employed to create the extremely sensitive devices that could detect very small changes in pressure. Fabricated devices were then tested in a custom made THz PA vacuum test chamber where the cantilever deflections caused by the photoacoustic effect were measured with a laser interferometer and iris beam clipped methods. The sensitive cantilever designs achieved a normalized noise equivalent absorption coefficient of 2.83x10^-10 cm^-1 W Hz^-1/2 using a 25 …

Physical Design Of A Smart Camera With Integrated Digital Pixel Sensors Using A 0.13Μm 8-Layer Metal Cmos Process, Mahir K. Gharzai

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The design of cameras has historically kept imagery and computational circuitry isolated in an attempt to maximize image quality by improving pixel pitch and routing density. Although this technique has worked in creating high density arrays of pixels for large resolution imagers, it has never been able to achieve high framerate computational operations.

A radical approach is introduced to solve this dilemma by creating compact, low- power pixel elements with built-in analog-to-digital converters that directly interface with digital logic. These pixels are capable of integrating alongside logic cells and to create an array of pixels inside the processor that can …

Semiconductor Thermal Neutron Detector, Toru Aoki, Aki Miyake, Takayuki Nakano, Akifumi Koike, Hisashi Morii, Hidenori Mimura

Makara Journal of Technology

The CdTe and GaN detector with a Gd converter have been developed and investigated as a neutron detector for neutron imaging. The fabricated Gd/CdTe detector with the 25 mm thick Gd was designed on the basis of simulation results of thermal neutron detection efficiency and spatial resolution. The Gd/CdTe detector shows the detection of neutron capture gamma ray emission in the 155Gd(n, g)156Gd, 157Gd(n, g)158Gd and 113Cd(n, g)114Cd reactions and characteristic X-ray emissions due to conversion-electrons generated inside the Gd film. The observed efficient thermal neutron detection with the Gd/CdTe detector shows its promise in neutron radiography application. Moreover, a …

The Effect Of Pressing Temperature And Time On The Quality Of Particle Board Made From Jatropha Fruit Hulls Treated In Acidic Condition, Apri Heri Iswanto, Fauzi Febrianto, Yusuf Sudo Hadi, Surdiding Ruhendi, Dede Hermawan

Makara Journal of Technology

The high of pH of jatropha fruit hulls causes the negative properties of particleboard made from this material. Adjusting the particle acidity and pressing conditions (temperature and time) is among the technical modifications available to improve this particleboard’s properties. Particle acidity has been adjusted in a previous research project, and immersing the particles in acetic acid was found to be the best treatment in this preliminary research. In order to improve the particleboard’s properties, an experiment was conducted to determine the best pressing temperature and time. The objective of the research was to evaluate the influence of pressing temperature and …

Radiation Characteristics Of A Planar Strip Dipole Antenna And A Slot Dipole Antenna For Thz Applications, Catur Apriono, Eko Tjipto Rahardjo

Makara Journal of Technology

The development of a THz system often requires a device that is used to radiate or detect THz waves. One way to fulfill this requirement is to use an antenna. Therefore, we need to consider the radiation characteristics of an antenna working in the THz region. In this paper, we present simulation study of two dipole antennas, i.e. a planar strip dipole antenna and a slot dipole antenna. The simulation results show that a planar strip dipole antenna has a better radiation efficiency (more than 95%) compared to the slot dipole. It also shows that an efficiency of more than …

Synthesis Of Tungsten Oxide Nanowires Onto Ito Glass Using T-Cvd, Tomy Abuzairi, Bohr-Ran Huang, Tzu-Ching Lin

Makara Journal of Technology

Tungsten oxide is an n-type semiconductor with interesting physical and chemical properties that make it suitable for various technological applications. Tungsten oxide nanowires were synthesized not only at low temperature but also without the use of any catalysts. The tungsten oxide nanowires were synthesized at 550 °C with tungsten layers onto the ITO glass using thermal chemical vapor deposition (T-CVD). The SEM image shows that the tungsten oxide nanowires are effectively grown with the 200 nm tungsten film. The Raman spectra shoulder at ~690 cm-1 proves the synthesized of tungsten oxide nanowires.

Microgrid Development Using A Grid Tie Inverter, Hartono Budi Santoso, Budiyanto Budiyanto

Makara Journal of Technology

The use of renewable energy sources (RES), especially photovoltaic (PV), to meet the demand of electrical energy has been getting a great deal of attention as an alternative solution to electrical energy deficit problems. RES are being applied in power systems in a variety of configurations including microgrid systems. One of the characteristics of a microgrid is capability to supplying power to grid when there is an excess power to supply local load. This research examines the chances of saving power consumption from grid using power converters grid tie inverter (GTI) in a microgrid configuration. The test is done by …

Recycling Roof Tile Waste Material For Wall Cover Tiles, Ambar Mulyono, Silfia Mona Aryani, Joko Lulut

Makara Journal of Technology

Prior research on roof tile waste treatment has attempted to find the appropriate technology to reuse old roof tile waste by create wall cladding materials from it. Through exploration and experimentation, a treatment method has been discovered to transform the tile fragments into artificial stone that resembles the shape of coral. This baked clay artificial stone material is then processed as a decorative element for vertical surfaces that are not load-bearing, such as on the interior and exterior walls of a building. Before applying the fragments as wall tiles, several steps must be taken: 1) Blunting, which changes the look …

Surface Treatment Of Fly Ash For Improving The Tensile Strength Of Fly Ash/Unsaturated Polyester Composites, Sugiman Sugiman, Paryanto Dwi Setyawan

Makara Journal of Technology

The paper presents the surface treatment of fly ashes using acid and alkali solution on the tensile strength of the fly ash/unsaturated polyester (UP) composites. Sulfuric acid (H2SO4), hydrofluoric acid (HF) and sodium hydroxide (NaOH) solution with concentration of 0%, 5%, 10%, 15%, and 20% (by weight) were used for surface treatment of fly ashes. Generally, the tensile strength of the treated fly-ash/UP composites shows a significant increase compared to the untreated fly ash. Of all surface treatments studied, the optimum tensile strength was obtained at a concentration of 10%. At this concentration, at a fly ash content of 30% …

Steady-State Voltage Security Assessment Using Symmetric Eigenvalue Analysis For Weak Area Identification In Large Power Transmission Network, Yagnaramasubramanian Somayajulu

Theses and Dissertations

The central focus of this thesis is on long-term static voltage stability analysis of large power transmission grid. This thesis work is a product of an attempt to comprehend the numerous researches that has been done over the years on voltage security assessment. Voltage stability is one of the essential components influencing the reliability of a power network. There are several Transmission planning and operation compliance standards pertaining to voltage criterion from NERC and Independent System Operators (ISO) directed toward the utilities to operate their grid within tight voltage limits. This requires the utility to perform comprehensive planning studies of …

Finding The Maximum And Minimum Magnitude Responses (Gains) Of Third-Order Filters Without Calculus, Kenneth V. Cartwright, Patrick Russell, Edit J. Kaminsky

Electrical Engineering Faculty Publications

The maximum and minimum gains (with respect to frequency) of third-order low-pass and high-pass filters are derived without using calculus. Our method uses the little known fact that extrema of cubic functions can easily be found by purely algebraic means. PSpice simulations are provided that verify the theoretical results.

Finding The Minimum Input Impedance Of A Second-Order Unity-Gain Sallen-Key Low-Pass Filter Without Calculus, Kenneth V. Cartwright, Edit J. Kaminsky

Electrical Engineering Faculty Publications

We derive an expression for the input complex impedance of a Sallen-Key second-order low-pass filter of unity gain as a function of the natural frequency , o  quality factor Q and the ratio of the resistors of the filter. From this expression, it is shown that the filter behaves like a single capacitor for low frequencies and as a single resistor at high frequencies. Furthermore, the minimum input impedance magnitude is found without using calculus. We discovered that the minimum input impedance magnitude is inversely proportional to Q and can be substantially less than its highfrequency value. Approximations to …

Angiography And Monitoring Of Hemodynamic Signals In The Brain Via Optical Coherence Tomography, Alana Mauluidy Soehartono

Theses and Dissertations

The brain is a complex network of interconnected neurons with each cell functioning as a nonlinear processing unit. Neural responses to stimulus can be described by activity in neurons. While blood flow changes have been associated with neural activity and are critical to brain function, this neurovascular coupling is not well understood. This work presents a technique for neurovascular interrogation, combining optogenetics and optical coherence tomography.

Optogenetics is a recently developed neuromodulation technique to control activity in the brain using light with precise spatial neuronal control and high temporal resolution. Using this method, cells act as light-gated ion channels and …

Investigation Of The Effects Of Rapid Thermal Annealing On Mbe Grown Gaasbi/Gaas Heterostructures For Optoelectronic Devices, Perry C. Grant

Graduate Theses and Dissertations

High efficiency optoelectronic devices rely on high quality materials making up the device structure. The scope of this thesis investigates the effectiveness of rapid thermal annealing (RTA) at improving the material quality of GaAsBi/GaAs heterostructures. During the fabrication of a device, the contacts of the device had the rapid thermal annealing process accomplished to produce ohmic contacts and this research explored if this annealing treatment degraded the quantum wells that made up the active region of a device. To investigate these effects, a system to measure the photoluminescence of the material system was constructed utilizing Fourier Transform Infrared Spectroscopy. The …

Portable Nano-Hydro Power Generator For The Dc House Project, Andrew Aw, James Biggs

Electrical Engineering

This senior project report explains the construction and design of a small, portable water generator that converts kinetic energy flowing in small creeks to electrical energy as a renewable source of energy for the DC House. The DC House, in short, is a project to build a self-sustainable house for Third World countries that utilizes only DC electricity. The system consists of two converters and a charge controller for a 12V lead-acid battery. The first converter converts the hydro generator voltage output to 15 Volts for safe and proper charging of the lead-acid battery by the charge controller. The second …

A Reconfigurable Digital-To-Analog Converter With Supply Invariant Linearity, Nicholas J. Chiolino

Graduate Theses and Dissertations

A novel reconfigurable digital-to-analog converter (DAC) with supply independent linearity is presented. The process agnostic converter achieves wide supply range operation and re-configurability by being charge based. This converter consists of a 7-bit parallel digital input control core and an analog "summing" core utilizing charging capacitors with an operational transconductance amplifier in a voltage-follower configuration. This topology is highly configurable to allow for optimization across process voltages, step sizes and low power operation. The specification of the DAC is (1) supply independence (2) low power operation (3) operation up to 200 kHz and (4) conversion control through a DAC enable …

A Wide Bandgap Silicon Carbide (Sic) Gate Driver For High Temperature, High Voltage, And High Frequency Applications, Ranjan Raj Lamichhane

Graduate Theses and Dissertations

The potential of silicon carbide (SiC) for modern power electronics applications is revolutionary because of its superior material properties including substantially better breakdown voltage, power density, device leakage, thermal conductivity, and switching speed. Integration of gate driver circuitry on the same chip, or in the same package, as the power device would significantly reduce the parasitic inductance, require far less thermal management paraphernalia, reduce cost and size of the system, and result in more efficient and reliable electrical and thermal performance of the system.

The design of a gate driver circuit with good performance parameters in this completely new under-development …

Microfluidics Guided By Redox-Magnetohydrodynamics (Mhd) For Lab-On-A-Chip Applications, Vishal Sahore

Graduate Theses and Dissertations

Unique microfluidic control actuated by simply turning off and on microfabricated electrodes in a small-volume system was investigated for lab-on-a-chip applications. This was accomplished using a relatively new pumping technique of redox-magnetohydrodynamics (MHD), which as shown in this dissertation generated the important microfluidic features of flat flow profile and fluid circulation. MHD is driven by the body force, FB = j × B, which is the magnetic part of the Lorentz force equation, and its direction is given by the right hand rule. The ionic current density, j, was generated in an equimolar solution of potassium ferri/ferro cyanide by applying …

Performance Evaluation Of Multiple Antenna Systems, M-Adib El Effendi

Theses and Dissertations

Wireless traffic is in a continuous increase and there are growing demands for wireless systems that support higher interference suppression and noise mitigation for mobile and cellular communications. Single antenna systems use frequency or time diversity to overcome the multipath fading effect as it represents a major problem that results in sever performance degradation. However, frequency diversity is inefficient in terms of bandwidth requirements and time diversity needs slow time varying channels. Space diversity has been proposed as an alternative to the former schemes where more antennas are added to the transmitter and/or receiver. Nevertheless, when multiple antennas are used; …

An On-Chip Transformer-Based Digital Isolator System, Cory Lynn Fandrich

Masters Theses

An on-chip transformer-based digital isolator has been designed, fabricated, and tested. This isolation technique is designed to function between a low voltage microcontroller and a potentially high-voltage power control system. The isolator’s isolation capability is determined by two factors, the RMS blocking voltage strength and common-mode transient immunity. The integrated circuit solution is designed in a high-temperature capable SOI process.

The on-chip transformer size is minimized by utilizing high frequency voltage pulses. A small transformer and overall small chip footprint of the design are favorable for integration into a larger system. The isolator is a two chip solution, an isolated …

Design Of A Low Power Cargo Security Device Using A Micropower Ultra-Wideband Impulse Radar, Brian M. Wihl

Master's Theses

Each year, thousands of cargo containers are broken into during shipping, costing billions of dollars in lost and damaged goods. In addition to removing its contents, intruders can also add unwanted and dangerous materials to a container, posing a threat to National Security. The possibilities of cargo container break-ins require that the containers go through check points at which they are physically searched. These searches often require the opening of the container, unloading and inspecting all cargo, and then loading the container and resealing it. This is a long and costly process.

Because of the high costs of break-ins and …

High Voltage Pulse Measurement System, Angelo J. Ballungay

Master's Theses

Using isolation and noise immunity techniques, this thesis designs and constructs a low cost measurement system to safely and accurately measure high voltage, high frequency pulses in harsh EM environments. High voltage pulses apply to medical, plasma, and food industries. The difficulty of accurately measuring high voltage pulses continues to pose an issue. Measuring high voltage systems can cause damage to the system, the measurement system, and the user. High voltage and high frequency pulses create a harsh environment of electromagnetic fields that can disrupt the circuitry of the measurement system and harm the user. Implementing isolation from the high …

A Sige Bicmos Lvds Driver For Space-Borne Applications, Matthew Ian Laurence

Masters Theses

When designing an integrated circuit for use during an interstellar mission, certain precautions must be made. The electronics on any off-earth mission will be exposed to wide temperature swings and harmful radiation due to being outside of the Earth’s protective ionosphere. It is crucial that any data path present be immune to these detrimental effects.

The introduction of galactic radiation can not only cause the onboard electronics to fail due to device degradation and single event latchup but can also lead to background radiation being coupled into the signal path as unwanted noise, degrading the signal to noise ratio. Unwanted …

Fea Estimation And Experimental Validation Of Solid Rotor And Magnet Eddy Current Loss In Single-Sided Axial Flux Permanent Magnet Machines, Xu Yang

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The rotor and magnet loss in single-sided axial ux permanent magnet (AFPM) machines with non-overlapped windings is studied in this dissertation. Finite element analysis (FEA) estimations of the loss are carried out using both 2D and 3D modeling. The rotor and magnet losses are determined separately for stator slot passing and MMF space harmonics from currents in the stator. The segregation of loss between the solid rotor plate and the magnet is addressed. The eddy current loss reduction by magnet segmentation is discussed as well. Two prototype 24 slot/22 pole single-sided AFPMs, fabricated with both single layer (SL) and double …

Limiting And Transient Performances Of A Low Loss Pin-Schottky Limiter, Chin-Leong Lim

Chin-Leong Lim

The main cause of loss in the PIN-Schottky limiter is the diodes’ parasitic capacitances. Techniques to counter the parasitic capacitances include using bare chip, air cavity packaging, diode stacking, mesa construction, isolating the Schottky diode from the signal path and connecting the diodes to a low impedance node. But the aforementioned techniques either sacrifice cost, manufacturability, size, performances or thermal ruggedness. To reduce loss in the PIN-Schottky limiter, we re-configured its parasitics into a low pass ladder network. This paper reports on the new configuration’s changed large signal and transient performances. We observed improved isolation at 0.9 and 2.4 GHz, …

Vehicular Motion Sensor: Developing A Wide-Range Motion Sensing Alarm System, Joshua Isaacson

Senior Honors Theses

Vehicular safety has become a serious concern in recent years. Many drivers have difficulty backing out of parking spaces, especially when large trucks and sport utility vehicles block the peripheral view from smaller vehicles. This can lead to accidents and pedestrian injuries when drivers are unable to see or do not pay careful attention to their surroundings.

Vehicular motion sensor systems can alert drivers of approaching obstacles when attempting to back out of parking spaces with limited visibility. This thesis aims to explain the limitations of current systems and the research conducted by the author to develop a prototype for …

Design Concepts Of Terahertz Quantum Cascade Lasers: Proposal For Terahertz Laser Efficiency Improvements, Tillmann Kubis, Saumitra Raj Mehrotra, Gerhard Klimeck

Gerhard Klimeck

Conceptual disadvantages of typical resonant phonon terahertz quantum cascade lasers 􏰎THz-QCLs􏰍 are analyzed. Alternative designs and their combination within a concrete device proposal are discussed to improve the QCL performance. The improvements are 􏰎1􏰍 indirect pumping of the upper laser level, 􏰎2􏰍 diagonal optical transitions, 􏰎3􏰍 complete electron thermalization, and 􏰎4􏰍 materials with low effective electron masses. The nonequilibrium Green’s function method is applied to predict stationary electron transport and optical gain. The proposed THz-QCL shows a higher optical gain, a lower threshold current, and a higher operation temperature. Alloy disorder scattering can worsen the QCL performance.

Digital Control Board For Phased Array Antenna Beam Steering In Adaptive Communication Applications, Mayur Bansal

Master's Theses

The application of adaptive communication techniques for mobile communications has attracted considerable interest in the last decade. One example of these techniques is spatial filtering through planar antenna array beam forming.

This thesis describes the development of a digital system that adaptively controls a phased array antenna. The radiating structure of the phased antenna array is tetrahedral-shaped and contains four antenna elements on each of its three faces. The overall system comprises of a digital control board with an external computer interface, an RF control board, and the phased antenna array. The RF controls the main lobe direction on the …

A Clamped Dual-Ridged Waveguide Measurement System For The Broadband, Nondestructive Characterization Of Sheet Materials, Milo W. Hyde Iv, Michael J. Havrilla

Faculty Publications

A novel two-port probe which uses dual-ridged waveguides for the nondestructive, broadband characterization of sheet materials is presented. The new probe is shown to possess approximately 2 to 3 times the bandwidth of traditional coaxial and rectangular/circular waveguide probe systems while maintaining the structural robustness characteristic of rectangular/circular waveguide probe systems. The theoretical development of the probe is presented, namely, by applying Love’s equivalence theorem and enforcing the continuity of transverse fields at the dual-ridged waveguide apertures, a system of coupled magnetic field integral equations is derived. The system of coupled magnetic field integral equations is solved using the method …

Silver Oxide-Graphene Sensor For Hydrogen Peroxide, Austin D. Scherbarth, L Stanciu

The Summer Undergraduate Research Fellowship (SURF) Symposium

A nonenzymatic, amperometric sensor for Hydrogen Peroxide (H₂O₂) was designed by drop coating glassy carbon electrodes (GCEs) with Silver Oxide (Ag₂O). Combining Ag₂O with Graphene Oxide and a polymer, PEDOT, was also attempted in order to increase stability and electrochemical properties. Using metal oxides along with Graphene Oxide for sensors has been done quite a bit, but Ag₂O itself has not been research extensively. So, in order to produce the best H₂O₂ sensor, the configuration of all components had to be optimized. Three different Ag₂O …