Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2008

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1801 - 1830 of 4190

Full-Text Articles in Engineering

Estimating The Subsonic Aerodynamic Center And Moment Components For Swept Wings, W. F. Phillips, Doug F. Hunsaker, R. J. Niewoehner Jun 2008

Estimating The Subsonic Aerodynamic Center And Moment Components For Swept Wings, W. F. Phillips, Doug F. Hunsaker, R. J. Niewoehner

Mechanical and Aerospace Engineering Faculty Publications

An improved method is presented for estimating the subsonic location of the semispan aerodynamic center of a swept wing and the aerodynamic moment components about that aerodynamic center. The method applies to wings with constant linear taper and constant quarter-chord sweep. The results of a computational fluid dynamics study for 236 wings show that the position of the semispan aerodynamic center of a wing depends primarily on aspect ratio, taper ratio, and quarter-chord sweep angle. Wing aspect ratio was varied from 4.0 to 20, taper ratios from 0.25 to 1.0 were investigated quarter-chord sweep angles were varied from 0 to …


Adaptive Quaternion Control Of A Miniature Tailsitter Uav, Nathan B. Knoebel, Timothy W. Mclain Jun 2008

Adaptive Quaternion Control Of A Miniature Tailsitter Uav, Nathan B. Knoebel, Timothy W. Mclain

Faculty Publications

The miniature tailsitter is a unique aircraft with inherent advantages over typical unmanned aerial vehicles. With the capabilities of both hover and level flight, these small, portable systems can produce efficient maneuvers for enhanced surveillance and autonomy with little threat to surroundings and the system itself. Such vehicles create control challenges due to the two different flight regimes. These challenges are addressed with a computationally efficient adaptive quaternion control algorithm. A backstepping method for model cancellation and consistent tracking of reference model attitude dynamics is derived. This is used in conjunction with a regularized data-weighting recursive least-squares algorithm for the …


Exploitation Of Surface Engineering Technology Research, David Kennedy Jun 2008

Exploitation Of Surface Engineering Technology Research, David Kennedy

Conference Papers

Surface engineering refers to a wide range of technologies that design and modify the surface properties and characteristics of components. The applications are very broad from macro to nano and from extremely hard materials to polymeric coatings. The uses are found in many engineering, energy, gas and oil, transport, medical, cosmetic, optical, chemical and sports industries. Research in this technology is ongoing and the benefits that can be derived are enormous. The design, wear and tribological properties of components for instance have been greatly enhanced by surface engineering and the economic benefits to industries far outweigh the cost and use …


Electric Elves: What Went Wrong And Why, Milind Tambe, Emma Bowring, Jonathan Pearce, Pradeep Reddy Varakantham, Paul Scerri, David V. Pynadath Jun 2008

Electric Elves: What Went Wrong And Why, Milind Tambe, Emma Bowring, Jonathan Pearce, Pradeep Reddy Varakantham, Paul Scerri, David V. Pynadath

Research Collection School Of Computing and Information Systems

Software personal assistants continue to be a topic of significant research interest. This article outlines some of the important lessons learned from a successfully-deployed team of personal assistant agents (Electric Elves) in an office environment. In the Electric Elves project, a team of almost a dozen personal assistant agents were continually active for seven months. Each elf (agent) represented one person and assisted in daily activities in an actual office environment. This project led to several important observations about privacy, adjustable autonomy, and social norms in office environments. In addition to outlining some of the key lessons learned we outline …


Bronchial Circulation Angiogenesis In The Rat Quantified With Spect And Micro-Ct, Christian Wieholt, David L. Roerig, John B. Gordon, Steven Thomas Haworth, Robert C. Molthen, Anne V. Clough Jun 2008

Bronchial Circulation Angiogenesis In The Rat Quantified With Spect And Micro-Ct, Christian Wieholt, David L. Roerig, John B. Gordon, Steven Thomas Haworth, Robert C. Molthen, Anne V. Clough

Biomedical Engineering Faculty Research and Publications

Introduction

As pulmonary artery obstruction results in proliferation of the bronchial circulation in a variety of species, we investigated this angiogenic response using single photon emission computed tomography (SPECT) and micro-CT.

Materials and methods

After surgical ligation of the left pulmonary artery of rats, they were imaged at 10, 20, or 40 days post-ligation. Before imaging, technetium-labeled macroaggregated albumin (99mTc MAA) was injected into the aortic arch (IA) labeling the systemic circulation. SPECT/micro-CT imaging was performed, the image volumes were registered, and activity in the left lung via the bronchial circulation was used as a marker of bronchial …


Theory, Simulation, Fabrication And Testing Of Double Negative And Epsilon Near Zero Metamaterials For Microwave Applications, Neil Patel Jun 2008

Theory, Simulation, Fabrication And Testing Of Double Negative And Epsilon Near Zero Metamaterials For Microwave Applications, Neil Patel

Master's Theses

Natural structures exhibiting simultaneous negative bulk permittivity and permeability have not yet been discovered. However, research interest over the past five years has grown with the proposition that artificial structures exhibiting these properties are realizable using specially-designed metallic inclusions embedded in host dielectric bodies. A periodic structure of metallic inclusions much smaller than the guided wavelength and embedded in a host dielectric medium is known in the physics and microwave communities as a "metamaterial". Such frequency-dependent effectively homogeneous materials may be designed to exhibit negative permeability and permittivity at certain frequencies. As predicted by electromagnetic theory, such negative index or …


Cfd As Applied To The Design Of Short Takeoff And Landing Vehicles Using Circulation Control, Tyler M. Ball Jun 2008

Cfd As Applied To The Design Of Short Takeoff And Landing Vehicles Using Circulation Control, Tyler M. Ball

Master's Theses

The ability to predict the distance required for an aircraft to takeoff is an essential component of aircraft design. It involves aspects related to each of the major aircraft systems: aerodynamics, propulsion, configuration, structures, and stability and control. For an aircraft designed for short takeoffs and landings (STOL), designing the aircraft to provide a short takeoff distance, or more precisely the balanced field length (BFL), often leads to the use of a powered lift technique such as circulation control (CC). Although CC has been around for many years, it has never been used on a production aircraft. This is in …


Development Of A Cell Depositing System Using Inkjet Technology, Jason Robert Ozaeta Jun 2008

Development Of A Cell Depositing System Using Inkjet Technology, Jason Robert Ozaeta

Master's Theses

In the past decade, advances in tissue engineering have allowed researchers to fabricate simple tissues. However, the process of creating these native tissues is a time consuming and inefficient process. A scaffold must first be fabricated then exposed to a sea of cells in the hopes of seeding. Furthermore, even though cells may have attached, more time must be spent in order to allow the cells to migrate to their ideal locations. To deal with this problem, researchers have investigated whether rapid prototyping principals could be adapted to facilitate the cell seeding process by placing cells in their respective locations …


Biomechanical And Radiographic Evaluation Of An Ovine Model For The Human Lumbar Spine, Nina E. Easley, M. Wang, Linda M. Mcgrady, Jeffrey M. Toth Jun 2008

Biomechanical And Radiographic Evaluation Of An Ovine Model For The Human Lumbar Spine, Nina E. Easley, M. Wang, Linda M. Mcgrady, Jeffrey M. Toth

Biomedical Engineering Faculty Research and Publications

While various species of animal models have been used in preclinical investigations of spinal implant devices to assess their biological adaptation and biomechanical performance, few studies have made comprehensive comparisons to validate their suitability of modelling the human spine. The purpose of this study was to assess essential biomechanical behaviours and disc morphology of the ovine lumbar model. Flexibility testing was conducted on the spines (L3—L4 and L4—L5) of nine skeletally matured sheep. Segmental rotation and intradiscal pressure were measured and load sharing between the intervertebral disc and posterior elements were calculated on the basis of a simplified parallel spring …


The Effect Of Substrate Properties On Print Attributes For Gravure Printing - From Proof To Press, Yu Ju Wu Jun 2008

The Effect Of Substrate Properties On Print Attributes For Gravure Printing - From Proof To Press, Yu Ju Wu

Dissertations

Gravure is the major printing process used for publication printing. In gravure printing processes, color proofing is for the purpose of checking the color to ensure that it is as desired. There is no doubt that paper properties have significant effects on the image reproduction for either printing or proofing processes. In order to achieve uniformity of printing and obtain good color reproduction performance, it is important that the all paper properties are well defined and controlled. This study investigates the correlations between paper properties and print quality/color reproduction for gravure publication printing and ink jet printing used in digital …


Density Relaxation Of Granular Matter Through Monte Carlo And Granular Dynamics Simulations, Oleksandr M. Dybenko May 2008

Density Relaxation Of Granular Matter Through Monte Carlo And Granular Dynamics Simulations, Oleksandr M. Dybenko

Dissertations

Granular materials are the principal ingredients of the industrial complex involved with the handling and processing of bulk solids including pharmaceuticals, chemicals, agricultural and mining materials. Despite the enormous importance of these materials in society, their behavior is not well-understood; in fact, there is no known model available that is capable of predicting the wide range of phenomenon that have been observed. One of the most important of these is known as density relaxation. Here, a granular material undergoes an increase in solids fraction as a result of the application of discrete taps or continuous vibrations.

In this dissertation, the …


Production Of Nanocrystalline Rdx By Ress : Development And Material Characterization, Victor Stepanov May 2008

Production Of Nanocrystalline Rdx By Ress : Development And Material Characterization, Victor Stepanov

Dissertations

The aim of the present work was to address the hazardous vulnerability of energetic materials to accidental initiation. An improved form of the explosive RDX with a significantly reduced sensitivity to stimuli including shock and impact was sought. The direction of this research was to investigate the effect of RDX crystal size reduction down to nano-scale dimensions on the sensitivity characteristics. Although size reduction of energetic crystals has been demonstrated often to result in a sensitivity reduction, the effect at the nano-scale particle size has not been investigated.

To generate nanocrystalline RDX a recrystallization process was developed based on rapid …


Optimal Allocation Of Blood Products, Godson A. Tetteh May 2008

Optimal Allocation Of Blood Products, Godson A. Tetteh

Dissertations

The high cost of collection and the short shelf life of apheresis platelets demand efficient inventory management to reduce outdates and shortages. Apheresis platelets are licensed for seven days, and blood centers are keen on knowing the consequences of various product collection and distribution strategies. To reduce outdates, inventory managers typically distribute the older units first, thereby following first-in first-out (FIFO) policy; however, hospital blood banks would prefer that the blood center issues out the freshest units first, equivalent to a last-in first-out (LIFO) policy. This study addresses the optimal distribution policy to achieve a desired outdate, shortage and average …


Optical Properties And Carrier Transport In Si/ Si1-Xgex Nanostructures, Eun Kyu Lee May 2008

Optical Properties And Carrier Transport In Si/ Si1-Xgex Nanostructures, Eun Kyu Lee

Dissertations

Defect-free epitaxial growth of Ge on a ~4 % lattice-mismatched single-crystal Si substrate is achieved using reduced dimension nanoscale heterostructures, where efficient structural relaxation might occur due to an enhanced adatom migrations and high surface-to-volume ratio. For development of novel electronic or optical devices based on these novel structures, understanding of their electrical and optical properties is crucial. This study explores the optical properties and carrier transport in two different types of Si/Si 1-xGe xnanostructures: Ge nanowires (NWs) forming nanoscale heterojunctions with Si substrates and multilayers of SiGe clusters embedded into a Si matrix.

Micron-long Ge nanowires grown …


Micro, Meso And Macro Materials Processing Using High-Speed Liquid Projectiles, Veljko Samardzic May 2008

Micro, Meso And Macro Materials Processing Using High-Speed Liquid Projectiles, Veljko Samardzic

Dissertations

The objective of this research is developmentof aknowledge base of materials processing by the impact of high-speed liquid projectiles. The work involved experimental study of generation and applications of high-speed liquid projectiles. The projectiles were generated by the launchers, which used gunpowder as an energy source. The experiments were carried out at the low (O.35g of the powder), middle (1.2g) and high (10g to 70g) levels of energy consumptions and at several different launchers modification.

Experimental investigation of effect of gun powder mass on energy of projectile was conducted for ductile and brittle targets. An array of experimental …


Removal And Recovery Of Fermentation-Produced Volatile Organic Compounds By A Novel Liquid Membrane-Based Pervaporation Technique, Atsawin Thongsukmak May 2008

Removal And Recovery Of Fermentation-Produced Volatile Organic Compounds By A Novel Liquid Membrane-Based Pervaporation Technique, Atsawin Thongsukmak

Dissertations

Pervaporation is an energy -- efficient alternative to distillation for removing volatile organic compounds (VOCs) from water especially solvents from their dilute solutions in a fermentation broth. Liquid membranes have high selectivities for removing solvents from aqueous solutions compared with polymeric membranes or ceramic membranes; however liquid membranes have stability problems due to various losses. The loss of liquid membrane (LM) to the feed solution leads to toxicity for the organisms in a fermentation broth. A new liquid membrane based pervaporation technique has been developed to achieve high selectivity, ensure stability and prevent contamination of the fermentation broth. Trioctylamine (TOA) …


Modeling Inventory And Responsiveness Costs In A Supply Chain, Robert Nearier May 2008

Modeling Inventory And Responsiveness Costs In A Supply Chain, Robert Nearier

Dissertations

Evaluation of supply chain performance is often complicated by the various interrelationships that exist within the network of suppliers. Currently many supply chain metrics cannot be analytically determined. Instead, metrics are derived from monitoring historical data, which is commonly referred to as Supply Chain Analytics. With these analytics it is possible to answer questions such as: What is the inventory cost distribution across the chain? What is the actual inventory turnover ratio? What is the cost of demand changes to individual suppliers? However, this approach requires a significant amount of historical data which must be continuously extracted from the associated …


Vector Support For Multicore Processors With Major Emphasis On Configurable Multiprocessors, Hongyan Yang May 2008

Vector Support For Multicore Processors With Major Emphasis On Configurable Multiprocessors, Hongyan Yang

Dissertations

It recently became increasingly difficult to build higher speed uniprocessor chips because of performance degradation and high power consumption. The quadratically increasing circuit complexity forbade the exploration of more instruction-level parallelism (JLP). To continue raising the performance, processor designers then focused on thread-level parallelism (TLP) to realize a new architecture design paradigm. Multicore processor design is the result of this trend. It has proven quite capable in performance increase and provides new opportunities in power management and system scalability. But current multicore processors do not provide powerful vector architecture support which could yield significant speedups for array operations while maintaining …


Derivation Of The Respiratory Rate Signal From A Single Lead Ecg, Murtaza M. Lakdawala May 2008

Derivation Of The Respiratory Rate Signal From A Single Lead Ecg, Murtaza M. Lakdawala

Theses

It has been long established that respiration has an influence on heart rate, and this effect is called respiratory sinus arrhythmia. As a result, two inferences can be postulated: first respiration information can be derived from cardiac activity, and second this effect offers the potential of removing the respiration effect that suppresses cardiac information which is of clinical significance. As a result of research performed at NJIT, there is a significant amount of data on exercise and heart rate recovery, but not the associated respiration signal. The motivation of this research was to compare and implement an optimal ECG derived …


Raman Scattering In Free Standing Porous Si Films, Thenappan Chidambaram May 2008

Raman Scattering In Free Standing Porous Si Films, Thenappan Chidambaram

Theses

In this thesis, Raman Scattering of free standing porous silicon on sapphire samples of controllably varying porosity is studied. The free standing, fully crystalline porous silicon films were prepared by electrochemical etching and the porous structure were lifted-off by a procedure based on electro-polishing. During Raman scattering measurements, the samples are exposed to relatively high intensity laser radiation. Free-standing porous Si sample temperature and thermal conductivity are calculated by comparing intensities of Stokes and anti-Stokes Raman peaks. Compared to crystalline Si, we find strong decrease in thermal conductivity accompanied by a change in the phonon spectra. Also, comparing Stokes and …


Experimental Investigation Of The Fluid Velocity Distribution In Stirred Tank Reactors Equipped With Retreat-Blade Impellers Using Laser Doppler Velocimetry, Deepak Rajesh Madhrani May 2008

Experimental Investigation Of The Fluid Velocity Distribution In Stirred Tank Reactors Equipped With Retreat-Blade Impellers Using Laser Doppler Velocimetry, Deepak Rajesh Madhrani

Theses

Stirred tank reactors are commonly used in the pharmaceutical industry for synthesis of Active Pharmaceutical Ingredients (API's) and their intermediates. Typically, these vessels are glass-lined and are provided with a single retreat-blade glass-lined impeller and a single baffle. Despite their ubiquitous utilization in the pharmaceutical industry for at least the past 40 years, the mixing characteristics of these systems have not been studied to any great extent, making it difficult to predict mixing performance in any given operation.

In this work, the velocity distribution inside the typical glass-lined vessel/impeller system was experimentally quantified using Laser Doppler Velocimetry (LDV), which is …


Interactions Between Adult Human Mesenchymal Stem Cells And Nanofibrous Scaffolds Of Different Compositions, Lisamarie Moore May 2008

Interactions Between Adult Human Mesenchymal Stem Cells And Nanofibrous Scaffolds Of Different Compositions, Lisamarie Moore

Theses

Stem cells have become increasingly important in the biomedical field because they have the potential to invade and regenerate damaged tissue. In particular, the bone marrow contains meesenchymal stem cells (MSCs) that have the capacity to differentiate into many cell lineages. The incorporation of MSCs within a multidimensional biomaterial provides a delivery vehicle to areas of injury. Natural and synthetic biomaterials can be made into scaffolds to represent different types of tissues. The ratio of synthetic to natural biomaterials in the scaffold influences the interaction with MSCs. This thesis created two different nanofibrous scaffolds by a process of electrospinning. The …


A Comparative Study Of Common Crosslinking Agents For Electrospun Collagen Scaffolds, Pallavi Masih May 2008

A Comparative Study Of Common Crosslinking Agents For Electrospun Collagen Scaffolds, Pallavi Masih

Theses

Cartilage injury is one of the leading causes of knee pain in the world. Over two million Americans suffer from cartilage injury every year, resulting in swelling, pain or joint impairment, causing it difficult to maintain an active life style. Synthetic grafts are used extensively to restore tissue functions. The major drawback limiting successful incorporation of synthetic grafts in body is their lower ability to integrate to natural tissue, poor biocompatibility which often results in triggering immunogenic responses, causing graft rejection. Collagen is thus studied and used excessively as a successful implantable material. The reason being that it is natural …


Process-Structure-Property Relationships Of Resorbable Desamino Tyrosine Derived Polymers : Effect Of Backbone Chemistry And Assembly On Drug Delivery, Pinar Nebol May 2008

Process-Structure-Property Relationships Of Resorbable Desamino Tyrosine Derived Polymers : Effect Of Backbone Chemistry And Assembly On Drug Delivery, Pinar Nebol

Theses

The selection the correct biomaterial for a specific medical application plays an important role for the success of both application and the device. Since different applications require different properties, investigation and improvement of biomaterials with different properties are very important. L-tyrosine derived polymers enable the manipulation of the properties of the material by changing backbone or pendent chain structure. L-tyrosine derived polyarylate is one of the class of these materials.

This study investigates the behavior of the tyrosine derived polyarylates under in vitro conditions. The change of structure caused by incubation in phosphate buffer solution and the effect on the …


Design And Construction Of A Novel Transpalpebral Ophthalmic Tonometer, Philippe R. Moinot May 2008

Design And Construction Of A Novel Transpalpebral Ophthalmic Tonometer, Philippe R. Moinot

Theses

Glaucoma -- a degeneration of the optic nerve- is a leading cause of blindness which is primarily caused by large fluctuations in intraocular pressure (lOP) known as diurnal variations. Because these peak in the early morning dropping off rapidly, a self administrable and inexpensive lOP home testing procedure is highly desirable. The approach contained herein -- unlike traditional Goldman applanation tonometry which requires the use of ophthalmic anesthetics and complex diagnostic equipment- describes a novel lOP measurement method consisting of concavation of the cornea or sclera through the palpebra superior by the spherical tip of an optoelectronic photodetector suspended in …


A Virtual Training Environment For Wheelchair Mounted Robot, Elizabeth Leichtnam May 2008

A Virtual Training Environment For Wheelchair Mounted Robot, Elizabeth Leichtnam

Theses

A model of a robotic manipulator designed to respond to different inputs from users with different skills or conditions is presented. This model can be adapted to different input variables and converted into joint angles which relate to movement in space of the manipulator's links. The algorithm allows for real time response and the features of the virtual environments (i.e., 3D design, stereoscopic vision) gives the designers the opportunity to use this model for training and usability evaluation according to the skills and different conditions that users could present.

Two types of virtual environments were created aiming to be used …


Radiation-Induced Osteoporosis: Bone Quantity, Architecture, And Increased Resorption Following Exposure To Ionizing Radiation, Jeffrey Willey May 2008

Radiation-Induced Osteoporosis: Bone Quantity, Architecture, And Increased Resorption Following Exposure To Ionizing Radiation, Jeffrey Willey

All Dissertations

Skeletal complications from radiation therapy have been described for breast, brain, pelvic, and blood cancers. These problems include atrophy, fractures, and osteoradionecrosis. Improved survivorship rates of cancer patients receiving radiotherapy increases the importance of understanding the causal mechanisms and long-term effects of radiation-induced bone loss. One such long-term effect is bone fractures following radiation therapy for cancer treatment. The incidence of hip fractures is significantly increased following targeted radiotherapy for cancer. This decline in bone health can have a severe impact on the patient's functional capabilities. This damage to bone following irradiation is thought to involve damage to both osteoblasts …


The Synergistic Effect Of Pulsed Electromagnetic Fields And Demineralized Bone Matrix On The Osteogenic Differentiation Of Mesenchymal Stem Cells, John Manocchio May 2008

The Synergistic Effect Of Pulsed Electromagnetic Fields And Demineralized Bone Matrix On The Osteogenic Differentiation Of Mesenchymal Stem Cells, John Manocchio

Theses

Orthopaedic bone grafting continues to be a mainstay in the treatment of non unions and other difficult to heal bone defects. Tissue engineering strategies have focused on providing bone graft materials that are osteoconductive, osteoinductive and osteogenic in order to achieve optimal bone healing. Furthermore, electrical stimulation technologies such as pulsed electromagnetic fields (PEMF) have been used to enhance the effectiveness of bone graft materials. PEMP has been shown to have a synergistic effect with BMP-2 and it was hypothesized that PEMF would have the same effect with demineralized bone matrix (DBM). In the present study human mesenchymal stem cells …


Altered Brain Activity In Autistic Children Versus Healthy Controls While Performing Simple Tasks Using Fmri, Donald Martin Adams Jr. May 2008

Altered Brain Activity In Autistic Children Versus Healthy Controls While Performing Simple Tasks Using Fmri, Donald Martin Adams Jr.

Theses

Functional magnetic resonance imaging (fMRI) studies dealing with Autistic children have primarily been concerned with cognitive facial recognition. Recent studies have demonstrated that Autistic children, when compared to healthy matched controls, exhibit higher neuronal activity when identifying patterns or objects, but lower levels of activity in regards to facial recognition.

The objective of this study was to examine both facial and object recognition and compare them to simple sensorimotor tasks. All subjects were administered 5 stimuli each lasting 320 seconds. Subjects were instructed to use a button press box to identify between a Person/Object and an Arrow/Object. They were then …


Automated Multi-Well Neural Injury Device, Linda Y. Chen May 2008

Automated Multi-Well Neural Injury Device, Linda Y. Chen

Theses

Traumatic Brain Injury (TBI) is a wide spread pathological problem occurring in 1.4 million individuals every year according to the National Institute of Neurological Disorders and Stroke. There are several types of TBI and the most prominent ones are concussion, contusion, hematoma, coup-contrecoup injury and diffuse axonal injury (DAI). The most severe type and the one that is the hardest to diagnose is DAI. DAI occurs mostly due to accidents relating to automobile, motorcycles and in some cases fall and assault, resulting in a "shearing" phenomenon of the brain. Patients with DAI can range from being, mildly injured, severely disabled …