Digital Commons Network^™

Location Based Services In Wireless Ad Hoc Networks, Neelanjana Dutta

Doctoral Dissertations

"In this dissertation, we investigate location based services in wireless ad hoc networks from four different aspects - i) location privacy in wireless sensor networks (privacy), ii) end-to-end secure communication in randomly deployed wireless sensor networks (security), iii) quality versus latency trade-off in content retrieval under ad hoc node mobility (performance) and iv) location clustering based Sybil attack detection in vehicular ad hoc networks (trust). The first contribution of this dissertation is in addressing location privacy in wireless sensor networks. We propose a non-cooperative sensor localization algorithm showing how an external entity can stealthily invade into the location privacy of …

Design, Development And Characterization Of A Novel Neutron And X-Ray Combined Computed Tomography System, Vaibhav Sinha

Doctoral Dissertations

"Visualizing the three dimensional structure of objects (e.g. nuclear fuel, nuclear materials, explosives and bio materials) and phenomena (e.g. particle tracking) can be very important in nondestructive testing applications. Computed tomography systems are indispensable tools for these types of applications because they provide a versatile non-destructive technique for analysis. A novel neutron and X-ray combined computed tomography (NXCT) system has been designed and developed at the Missouri University of Science & Technology. The neutron and X-ray combined computed tomography system holds much promise for non-destructive material detection and analysis where multiple materials having similar atomic number and differing thermal cross …

Polybenzoxazine Aerogels: Synthesis, Characterization, Conversion To Porous Carbons, And Energetic Composites, Shruti Mahadik-Khanolkar

Doctoral Dissertations

"Aerogels are nanoporous, low-density bulk objects, consisting of three-dimensional assemblies of nanoparticle. Structured similarly, polymeric aerogels are emerging as a mechanically strong alternative to traditional silica aerogels, which are fragile. Amongst polymeric aerogels, those based on polybenzoxazine (PBO - a type of phenolic resin), are extremely robust and comprise an economic alternative to resorcinol-formaldehyde aerogels, also a class of phenolic resins, as the main source of carbon aerogels. The drawback of the PBO chemistry has been the long (days) processing time at high-temperatures (>130 ºC). Herewith, we have developed an energy- and time-efficient process to PBO aerogels by inducing …

Common Mode Current Estimation For Cable Bundle Inside A Vehicle, Dazhao Liu

Doctoral Dissertations

"In the Section 1, it introduces a methodology to simulate the currents and fields during an air discharge ESD into a product by combining a linear description of the behavior of the DUT with a non-linear arc resistance equation. The most commonly used test standard IEC 61000-4-2 requires using contact mode discharges to metallic surfaces and air discharge mode to non-conducting surfaces. This paper proposes a method that combines the linear ESD generator full wave model and the non-linear arc model to simulate currents and fields in air discharge mode. In Section 2, when simulating surface and thin wire structures, …

Study Of Artificially Disordered Optical Fibers, Herath Mudiyanselage Sumudu Rasika Kumari Herath

Doctoral Dissertations

"Light transmission through photo-sensitive multi-mode fibers (MMF) with controlled volume disorder is investigated. Experiment shows that a segment of disordered MMF as short as 10 cm is sufficient to distribute power uniformly over all co-propagating modes and the intensity at the output surface of the fiber follows the Rayleigh negative exponential function. To explain the experimental findings, a comprehensive theoretical model is developed with three main results. First, statistical properties of all components of the dielectric tensor are obtained and analyzed in the framework a microscopical model of photo-sensitivity in a germano-silicate glasses. Secondly, it is shown that induced birefringence …

Observability-Enhanced Dual-Filter Design For Attitude Estimation With Minimum Observations, Jason D. Searcy

Doctoral Dissertations

"Determining spacecraft attitude in real time using only magnetometer data presents a challenging filtering problem. A flexible and computationally efficient method for solving the spacecraft attitude using only an inexpensive and reliable magnetometer would be a useful option for satellite missions, particularly those with modest budgets. The primary challenge is that magnetometers only instantaneously resolve two axes of the spacecraft attitude. Typically, magnetometers are used in conjunction with other sensors to resolve all three axes. However, by using a filter over an adequately long orbit arc, the magnetometer data can yield full attitude, and in near real time. The method …

Finite-Horizon Optimal Control Of Linear And A Class Of Nonlinear Systems, Qiming Zhao

Doctoral Dissertations

"Traditionally, optimal control of dynamical systems with known system dynamics is obtained in a backward-in-time and offline manner either by using Riccati or Hamilton-Jacobi-Bellman (HJB) equation. In contrast, in this dissertation, finite-horizon optimal regulation has been investigated for both linear and nonlinear systems in a forward-in-time manner when system dynamics are uncertain. Value and policy iterations are not used while the value function (or Q-function for linear systems) and control input are updated once a sampling interval consistent with standard adaptive control. First, the optimal adaptive control of linear discrete-time systems with unknown system dynamics is presented in Paper I …

Interacting Stress Concentration Factors And Their Effect On Fatigue Of Metallic Aerostructures, David Warren Whitley

Doctoral Dissertations

"During fabrication of certain aerostructure components, a situation can arise where a hole is mislocated so that it interferes with a radius, chem-mill step, machined step, or some other similar detail. The interaction of stress concentration effects between a hole and step are not well understood and the resulting impact on fatigue performance is difficult to predict. There exists a need for fatigue data that can be used to determine the analysis methods for evaluation of the interaction of machined steps and fastener holes. In this dissertation, the effect of stress concentrations placed in close proximity to each other and …

Regional Geomorphic Analysis And Gis Susceptibility Mapping Of Landslides In The Blue Nile And The Tekeze River Basins Of Ethiopia, Elamin Hassan Dai Ismail

Doctoral Dissertations

"The Plateau region of Ethiopia lies within a seismically active continental extensional regime, which is being rapidly incised by the Blue Nile and the Tekeze Rivers. Extremely large landslides pose serious hazards in this highly populated region (>27 million), which is in the process of developing its hydrologic resources. This research sought to develop cost-effective methods to compile regional landslide inventory and landslide susceptibility maps, using geomorphic tools and GIS technologies. This work also sought to evaluate the relationships between landslide dams and knickpoints, caused by channel bed incision from those caused by slope failures, by utilizing identified knickpoints …

Numerical Analyses Of Long Carbon Fiber Reinforced Concrete Panels Exposed To Dynamic Loading, Zahra Sadat Tabatabaei

Doctoral Dissertations

"The purpose of this research was to evaluate impact and blast performance of long carbon fiber reinforced concrete experimentally and numerically. Experimental tests were conducted on plain concrete (PC), reinforced concrete, and four different types of long carbon fiber reinforced concrete (LCFRC). The results from each test were then compared to one another. This comparison indicates that adding long carbon fibers to concrete both increases the post-cracking behavior of concrete and decreases the spalls in either an impact or blast test. Among all of the fibers tested, Fiber Type B3 outperformed the other fibers, absorbing more energy during impact. Numerical …

Privacy-Preserving Friend Recommendations In Online Social Networks, Bharath Kumar Samanthula

Doctoral Dissertations

"Online social networks, such as Facebook and Google+, have been emerging as a new communication service for users to stay in touch and share information with family members and friends over the Internet. Since the users are generating huge amounts of data on social network sites, an interesting question is how to mine this enormous amount of data to retrieve useful information. Along this direction, social network analysis has emerged as an important tool for many business intelligence applications such as identifying potential customers and promoting items based on their interests. In particular, since users are often interested to make …

Advances In Blind Source Separation, Christopher Osterwise

Doctoral Dissertations

"Blind Source Separation (BSS) is a classic problem that attempts to separate unknown sources from observed mixtures. A common framework of this is the Cocktail Party problem, where multiple individuals speaking in a noisy room are recorded by a configuration of microphones, with the challenge being to split the observed signals into individual conversations. This dissertation covers the evaluation of an existing algorithm known as Cascaded ICA with Intervention Alignment (CICAIA), the establishment of a new parameter for characterizing blind mixtures, and three new algorithms, of which two are capable of separating any number of sources given more microphones than …

Development Of An Integrative Commissioning Methodology For New-Building Construction, William L. Gillis Iii

Doctoral Dissertations

"Commissioning (Cx) is a quality process for building construction used to verify that the owner's project requirements (OPR) are being met by the final design, construction, and operations and maintenance. The goal is to confirm that each phase of the project is linked back to the OPR through quality assurance methods. Leadership in Energy and Environmental Design (LEED) certification is an OPR which contributes to difficulties within the design and construction (D&C) process. Though LEED certification is only part of the OPR, too often the design drifts from the OPR and simply focuses on meeting the LEED certification.

Quality function …

Effect Of Dense Heat Exchanging Internals On The Hydrodynamics Of Bubble Column Reactors Using Non-Invasive Measurement Techniques, Mohammed Khloofh Al Mesfer

Doctoral Dissertations

"Given their efficiency and capital cost reduction, bubble/slurry bubble column reactors are the reactors of choice for Fischer-Tropsch (FT) synthesis, offering clean alternative fuels and chemicals. FT synthesis is an exothermic process that requires many heat exchanging tubes in order to remove heat efficiently and maintain the desired temperature and isothermal operating condition. The impact of the heat exchanging tubes (internals) on the hydrodynamics is not fully understood. Reliably designing and scaling up bubble column reactors requires proper understanding of hydrodynamics, as well as heat and mass transfer parameters.

The main objective of this work is to advance the understanding …

Spatial Variation Of Amd Related Co₂ Emissions On Reclaimed Mine Spoil, Moagabo Mathiba

Doctoral Dissertations

"Carbon dioxide (CO₂) from acid mine drainage (AMD)-carbonate neutralization reactions in reclaimed mine spoils, can intermittently invade homes and structures constructed on or adjacent to these spoils in hazardous and even lethal concentrations (>15%) and rendering them uninhabitable. This phenomenon is beginning to be recognized as an emerging environmental, safety and health threat with potential environmental and financial liability for mine operators, developers and owners.

Like in natural soils, soil temperature and moisture, and possibly elevation are likely to influence CO₂ emissions from reclaimed mine spoils. However, mine spoil soils are heterogeneous and have significant convective transport due to …

Sediment Impact On The Formation Of Hypoxic Waters In The Northern Gulf Of Mexico: A Synthesis Of Sediment Texture, Composition, Erodibility And Transport, Rangley Claude Mickey

Electronic Theses and Dissertations

Annual hypoxic events have been found to occur over the past several decades in the northern Gulf of Mexico (nGOM) and have prompted researchers to begin studying the mechanisms that control hypoxia formation so they may advise policy makers on the appropriate mitigating responses. This has led to the development of 3-dimensional modeling systems that incorporate marine physical, biological, geological, and chemical processes that may impact the formation and duration of hypoxic regimes in the nGOM. This study used field, laboratory, and modeling techniques to examine how sediment may be eroded from the seabed and where/how it is transported across …

Evaluation Of Single Electron Transfer Reduction Products Of 3-Oxoindoles As Antibacterial Agents, Debasish Bandyopadhyay, Irani Biswas, Subrata Laskar, Bidyut Basak

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Objective: The objective of the present study is to assess the antibacterial properties of six indole derivatives viz, 3-(Naphth-1-y - methyl) –indole (II), 3-(1-Naphthylcarbonyl – indole (III), 3,3' –diformyl-2,2' –bis indole (IV), 1,4- (3,3' –di indolyl) – 1,4-dioxobutane (V), 3-benzoyl indole (VI) and 1,1 – bis – (3-indolyl)- ethane (VII) synthesized by single electron transfer reduction of 3-formylindole (I) against two Gram +ve and two Gram –ve bacteria which usually cause human infections.

Methods: Synthesis of 3-formyl indole from which the indole derivatives were prepared were further characterized by IR and NMR analysis. The six synthesized compounds were screened for …

The Organizational Commitment Of Chief Housing Officers, Curtis Erwin, Brenda L.H. Marina

Journal of Higher Education & Student Affairs

The purposes of this study was to ( 1) examine the extent that locus of control influences the organizational commitment of Chief Housing Officers and (2) review background factors such as gender, salary range, and institutional type Chief Housing Officers and any relationships related to level of locus of control and organizational commitment. The role of Chief Housing Officers requires a wide array of skills, which include a multitude of daily job stressors. How a Chief Housing Officer manages these stressors has an impact on the success, and longevity of his or her career within the role. When organizational commitment …

An Examination Of Middle School Counselors' Comfort With Technology, Patricia Christina Roddy

Theses and Dissertations

The purpose of the current study was to investigate the differences in comfort with technology in middle school counselors in South Carolina. The researcher’s goal was to determine the effects of years of experience, technology training, gender, and age on middle school counselors’ comfort with technology.

After a review of literature, it was determined that this study was warranted to determine middle school counselors’ comfort with technology. As technology progresses, it is critical that school counselors are appropriately trained to utilize technology in their work. Their comfort levels with technology should be as strong as their ability to use a …

Professional Conversations About Race, Culture And Language In Early Childhood Literacy Education: An Administrator's Journey, Sabina Maria Mosso-Taylor

Theses and Dissertations

Year after year, children of Color, speakers of languages other than English, and children of poverty are served less well in public schools then their White, middle-class peers. The lives of children from White, middle-class homes are regularly normalized as they are described by teachers, administrators, policy makers, and educational programs as those with the most worth and knowledge. In all too many settings, cultures and languages outside this narrowly-defined norm are perceived from deficit perspectives. This hierarchy perpetuates a status quo that privileges and therefore supports the success of some, while devaluing and contributing to the failure of others. …

Statistical Optimization Of Mesalamine Pulsatile Release Ph Dependent Coated Pellets For Possible Ileo-Cecal Targeting, Hemant H. Gangurde, Mayur A., S. Tamizharasi, T. Sivakumar

The Thai Journal of Pharmaceutical Sciences

No abstract provided.

Permaganometric Determination Of Sumatriptan Succinate In Pure Drug And Pharmaceutical Formulation, K.N. Prashanth, K. Basavaiah, M.S. Riaghu

The Thai Journal of Pharmaceutical Sciences

Based on the reduction of permanganate by sumatriptan succinate (STS) in acidic medium, two simple, sensitive and cost-effective methods were described for the determination of STS in bulk drug and in formulation. In titrimetry (method A), STS was oxidized by a known excess of potassium permanganate (KMnO₄) in H₂SO₄ medium followed by determination of unreacted permanganate by titration with ferrous ammonium sulphate. In spectrophotometry (method B), STS was treated with a measured excess of permanganate in acid medium and the unreacted oxidant was measured at 545 nm. The molar combining ratio in titrimetry and the optimum assay conditions were studied. …

Antibacterial Activitry Of Crude Extracts From Edible Mushrooms Pleurotus Citrinopileatus And Tricholoma Crassum Berk, Prontep Chomcheon, Bancha Kheawkum, Pornsinee Sriwiset, Suphak Dulsamphan, Chalernkieat Dulsamphan

The Thai Journal of Pharmaceutical Sciences

The purpose of this research was to study antibacterial activity of crude extracts derived from the culture broths of two edible mushrooms, Pleurotus citrinopileatus and Tricholoma crassum Berk, cultivated in submerged fermentation. Potato dextrose broth (PDB) and yeast extract sucrose broth (YES) were used as culture media. Each culture filtrate was extracted and evaporated to yield a crude extract. Antibacterial activities against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923 were determined by paper disc diffusion assay. Crude extract (1 mg) of P. citrinopileatus culturing PDB showed the widest inhibition zones against E. coli ATCC 25922 (34.47 ± 0.50 …

In Vitro Stimulatory Effect Of Grandiflorenic Acid Isolated From Wedelia Trilobata (L.) Leaves On L929 Fibroblast Cells, Neelam Balekar, Titpawan Nakpheng, Teerapol Srichana

The Thai Journal of Pharmaceutical Sciences

Wedelia trilobata (L.) has been used in traditional medicine in the Caribbean and Central America for stubborn wounds, sores, swelling and arthritic painful joints. The aim of the study was to evaluate the activity of grandiflorenic acid obtained from le...

Evaluation Of The Wound Healing Potential Of Albizzia Lebbeck (L.) Bark, Neelam Balekar, Dinesh Kumar, Rajesh Kumar Upadhyay

The Thai Journal of Pharmaceutical Sciences

The present study was performed to substantiate the traditional claim of the wound healing activity of stem bark of Albizzia lebbeck Linn. in rats. The effects of aqueous and ethanolic extracts of stem bark of A. lebbeck (5% and 10% w/v topically and 250...

Development And Validation Of Hptlc Densitometric Method For Simultaneous Determination Of Antazoline Hydrochloride And Tetryzoline Hydrochloride In Eye Drop And Its Application As Stability Indicator, Anbessa Bekele Ariaya Hymete, Adnan A. Bekhit

The Thai Journal of Pharmaceutical Sciences

A sensitive, selective, precise, accurate and stability indicating high-performance thin layer chromatographic (HPTLC)-densitometric method for analysis of antazoline hydrochloride and tetryzoline hydrochloride was developed. The method employed HPTLC al...

Association Of Abcb1 Polymorphism With Lamotrigine-Resistant Epilepsy In Thais, Korakot Buathet, Yotin Chinvarun, Somchai Towanabut, Pornpimol Kijsanayotin

The Thai Journal of Pharmaceutical Sciences

Along with clinical and environmental factors, genetic variability in P-glycoprotein (P-gp) encoded by the ATP-binding cassette (ABC)B1 gene may influence inter-individual variability in antiepileptic drug response by limiting drug absorption and brain a...

Eudragit Rs 100 Nanosuspensions For The Controlled Ophthalmic Delivery Of Diclofenac Sodium, Swamy N.G.N., Zaheer Abbas, Santosh Kumar I.H.

The Thai Journal of Pharmaceutical Sciences

The aim of this study was to prepare and characterize diclofenac sodium-loaded Eudragit RS 100-based nanosuspensions for controlled ophthalmic delivery in the management of ocular inflammatory conditions with an intention to provide long-term extraocular...

Author Index, Keyword Index, N/A

The Thai Journal of Pharmaceutical Sciences

No abstract provided.

Antioxidant Activities And Phytochemicals Of Edible Flowers, Jeerawat Sawatpipat., Vatin Phunsawat, Piyanuch Rojsanga, Pongtip Sithisarn

The Thai Journal of Pharmaceutical Sciences

No abstract provided.