Current Search: engineering (x)
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- Title
- Factors Affecting Systems Engineering Rigor in Launch Vehicle Organizations.
- Creator
-
Gibson, Denton, Karwowski, Waldemar, Rabelo, Luis, Kotnour, Timothy, Kern, David, University of Central Florida
- Abstract / Description
-
Systems engineering is a methodical multi-disciplinary approach to design, build, and operate complex systems. Launch vehicles are considered by many extremely complex systems that have greatly impacted where the systems engineering industry is today. Launch vehicles are used to transport payloads from the ground to a location in space. Satellites launched by launch vehicles can range from commercial communications to national security payloads. Satellite costs can range from a few million...
Show moreSystems engineering is a methodical multi-disciplinary approach to design, build, and operate complex systems. Launch vehicles are considered by many extremely complex systems that have greatly impacted where the systems engineering industry is today. Launch vehicles are used to transport payloads from the ground to a location in space. Satellites launched by launch vehicles can range from commercial communications to national security payloads. Satellite costs can range from a few million dollars to billions of dollars. Prior research suggests that lack of systems engineering rigor as one of the leading contributors to launch vehicle failures. A launch vehicle failure could have economic, societal, scientific, and national security impacts. This is why it is critical to understand the factors that affect systems engineering rigor in U.S. launch vehicle organizations.The current research examined organizational factors that influence systems engineering rigor in launch vehicle organizations. This study examined the effects of the factors of systems engineering culture and systems engineering support on systems engineering rigor. Particularly, the effects of top management support, organizational commitment, systems engineering support, and value of systems engineering were examined. This research study also analyzed the mediating role of systems engineering support between top management support and systems engineering rigor, as well as between organizational commitment and systems engineering rigor. A quantitative approach was used for this. Data for the study was collected via survey instrument. A total of 203 people in various systems engineering roles in launch vehicle organizations throughout the United States voluntarily participated. Each latent construct of the study was validated using confirmatory factor analysis (CFA). Structural equation modeling (SEM) was used to examine the relationships between the variables of the study. The IBM SPSS Amos 25 software was used to analyze the CFA and SEM.
Show less - Date Issued
- 2019
- Identifier
- CFE0007806, ucf:52348
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007806
- Title
- USING AUGMENTED REALITY FOR STUDYING LEFT TURN MANEUVER AT UN-SIGNALIZED INTERSECTION AND HORIZONTAL VISIBILITY BLOCKAGE.
- Creator
-
Moussa, Ghada, Radwan, Essam, University of Central Florida
- Abstract / Description
-
Augmented reality "AR" is a promising paradigm that can provide users with real-time, high-quality visualization of a wide variety of information. In AR, virtual objects are added to the real-world view in a real time. Using the AR technology can offer a very realistic environment for driving enhancement as well as driving performance testing under different scenarios. This can be achieved by adding virtual objects (people, vehicles, hazards, and other objects) to the normal view while...
Show moreAugmented reality "AR" is a promising paradigm that can provide users with real-time, high-quality visualization of a wide variety of information. In AR, virtual objects are added to the real-world view in a real time. Using the AR technology can offer a very realistic environment for driving enhancement as well as driving performance testing under different scenarios. This can be achieved by adding virtual objects (people, vehicles, hazards, and other objects) to the normal view while driving in a safe controlled environment. In this dissertation, the feasibility of adapting the AR technology into traffic engineering was investigated. Two AR systems; AR Vehicle "ARV" system and Offline AR Simulator "OARSim" system were built. The systems' outcomes as well as the on-the-road driving under the AR were evaluated. In evaluating systems' outcomes, systems were successfully able to duplicate real scenes and generate new scenes without any visual inconsistency. In evaluating on-the-road driving under the AR, drivers' distance judgment, speed judgment, and level of comfort while driving were evaluated. In addition, our systems were used to conduct two traffic engineering studies; left-turn maneuver at un-signalized intersection, and horizontal visibility blockage when following a light truck vehicle. The results from this work supported the validity of our AR systems to be used as a surrogate to the field-testing for transportation research.
Show less - Date Issued
- 2006
- Identifier
- CFE0001430, ucf:47044
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001430
- Title
- VERSATILITY AND CUSTOMIZATION OF PORTABLE CMM IN REVERSE ENGINEERING APPLICATIONS.
- Creator
-
Thiraviam, Amar Raja, Hosni, Yasser, University of Central Florida
- Abstract / Description
-
Reverse engineering is the technique of gathering scientific knowledge about a part by physically examining it. In the computer aided manufacturing world this is referred to as Part to CAD conversion, where the geometry of physical objects are being captured as Digital 3-D CAD Data. This is vital not only to produce drawing of parts for which no CAD data exists, but also is frequently being used to produce better designs. The industry professionals to achieve this are frequently using...
Show moreReverse engineering is the technique of gathering scientific knowledge about a part by physically examining it. In the computer aided manufacturing world this is referred to as Part to CAD conversion, where the geometry of physical objects are being captured as Digital 3-D CAD Data. This is vital not only to produce drawing of parts for which no CAD data exists, but also is frequently being used to produce better designs. The industry professionals to achieve this are frequently using Coordinate Measuring Machine [CMM] among other tools. The purpose of this thesis is to demonstrate the versatility of portable CMM as a Reverse Engineering Tool through application experiments aimed at industrial and non-industrial solutions. The thesis also researches in to the feasibility of customization options through experimentations focused on reverse engineering. Focusing further on Reverse Engineering applications, some of the interesting digitizing and CAD techniques are demonstrated and compared.
Show less - Date Issued
- 2004
- Identifier
- CFE0000219, ucf:46248
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000219
- Title
- A PREDICTIVE MODEL FOR BENCHMARKING ACADEMIC PROGRAMS (PBAP)USING U.S. NEWS RANKING DATA FOR ENGINEERING COLLEGES OFFERING GRADUATE PROGRAMS.
- Creator
-
Chuck, Lisa, Tubbs, LeVester, University of Central Florida
- Abstract / Description
-
Improving national ranking is an increasingly important issue for university administrators. While research has been conducted on performance measures in higher education, research designs have lacked a predictive quality. Studies on the U.S. News college rankings have provided insight into the methodology; however, none of them have provided a model to predict what change in variable values would likely cause an institution to improve its standing in the rankings. The purpose of this study...
Show moreImproving national ranking is an increasingly important issue for university administrators. While research has been conducted on performance measures in higher education, research designs have lacked a predictive quality. Studies on the U.S. News college rankings have provided insight into the methodology; however, none of them have provided a model to predict what change in variable values would likely cause an institution to improve its standing in the rankings. The purpose of this study was to develop a predictive model for benchmarking academic programs (pBAP) for engineering colleges. The 2005 U.S. News ranking data for graduate engineering programs were used to create a four-tier predictive model (pBAP). The pBAP model correctly classified 81.9% of the cases in their respective tier. To test the predictive accuracy of the pBAP model, the 2005 U.S .News data were entered into the pBAP variate developed using the 2004 U.S. News data. The model predicted that 88.9% of the institutions would remain in the same ranking tier in the 2005 U.S. News rankings (compared with 87.7% in the actual data), and 11.1% of the institutions would demonstrate tier movement (compared with an actual 12.3% movement in the actual data). The likelihood of improving an institution's standing in the rankings was greater when increasing the values of 3 of the 11 variables in the U.S. News model: peer assessment score, recruiter assessment score, and research expenditures.
Show less - Date Issued
- 2005
- Identifier
- CFE0000431, ucf:46377
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000431
- Title
- A COMPARATIVE ANALYSIS OF GREEN ROOF DESIGNS INCLUDING DEPTH OF MEDIA, DRAINAGE LAYER MATERIALS, AND POLLUTION CONTROL MEDIA.
- Creator
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Kelly, Matt, Cooper, C. David, University of Central Florida
- Abstract / Description
-
Population growth has lead to an increase in development and impervious areas in urban settings. Post-development conditions cause several problems for stormwater management such as limited space for stormwater storage systems and the conveyance of pollution picked up by runoff to near by water bodies. Green Roofs with cisterns have been shown to attenuate the peak flow of storm events and reduce the pollution load leaving a site and entering nearby water bodies. The purpose of this research...
Show morePopulation growth has lead to an increase in development and impervious areas in urban settings. Post-development conditions cause several problems for stormwater management such as limited space for stormwater storage systems and the conveyance of pollution picked up by runoff to near by water bodies. Green Roofs with cisterns have been shown to attenuate the peak flow of storm events and reduce the pollution load leaving a site and entering nearby water bodies. The purpose of this research is to expand the available research data on green roofs with cisterns by investigating the water quality and hydrology effects of different green roof designs including depth of media, an additional pollution control layer beneath the growth media, and different drainage layer materials. Furthermore, a comparison study is performed on the cistern water quality, direct filtrate water quality, and control roof filtrate water quality. Results show that phosphorus concentrations are lower when using a pollution control layer beneath the growing media, and that evapotransporation and filtrate factor values from the 4-inch media and the 8-inch media are approximately equal for one year. However, hydrograph results show that the 8-inch media design has a lower peak flow and longer attenuation when compared to the 4-inch media design for a single storm event. Furthermore, the drainage layer material has no significant effect on the water quality or hydrology of the green roof discharge. The data also emphasizes the importance and effectiveness of the incorporation of a cistern into a green roof system.
Show less - Date Issued
- 2008
- Identifier
- CFE0002107, ucf:47552
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002107
- Title
- TISSUE ENGINEERING THE MOTONEURON TO MUSCLE SEGMENT OF THE STRETCH REFLEX ARC CIRCUIT UTILIZING MICRO-FABRICATION, INTERFACE DESIGN AND DEFINED MEDIUM FORMULATION.
- Creator
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DAS, MAINAK, Hickman, James, University of Central Florida
- Abstract / Description
-
The stretch reflex circuit is one of the most primitive circuits of mammalian system and serves mainly to control the length of the muscle. It consists of four elements: the stretch sensor (muscle spindle/ intrafusal fiber lie parallel between extrafusal, contractile musculature), extrafusal muscle fiber, sensory neuron and motoneuron. The basic principle of the stretch reflex arc circuit is as follows: whenever there is a sudden stretch in a muscle, it needs to compensate back to its...
Show moreThe stretch reflex circuit is one of the most primitive circuits of mammalian system and serves mainly to control the length of the muscle. It consists of four elements: the stretch sensor (muscle spindle/ intrafusal fiber lie parallel between extrafusal, contractile musculature), extrafusal muscle fiber, sensory neuron and motoneuron. The basic principle of the stretch reflex arc circuit is as follows: whenever there is a sudden stretch in a muscle, it needs to compensate back to its original length so as to prevent any kind of injury. It performs this compensation process using a simple negative feed back circuit called the stretch reflex arc. Any form of stretch in a muscle activates the stretch sensors (muscle spindle/ intrafusal fiber) lying deep in each muscle. After the stretch sensors get activated, it sends a train of signals to the spinal cord through the sensory neurons. The sensory neurons relay this information to the motoneuron. The motoneuron performs the necessary information processing and sends the message to the extrafusal fibers so as to compensate for the sudden stretch action. The motoneuron conveys this message to the extrafusal fibers by communicating through the special synaptic junctions called neuromuscular junctions. Based on this information, the extrafusal fibers act accordingly so as to counter the effect of sudden stretch. This is also called the monosynaptic stretch reflex that involves a single synapse between a sensory neuron and a motoneuron. To date studying these stretch reflex circuits is only feasible in animal models. Almost no effort has been made to tissue engineer such circuits for a better understanding of the complex development and repair processes of the stretch reflex circuit formation. The long-term goal of this research is to tissue engineer a cellular prototype of the entire stretch reflex circuit. The specific theme of this dissertation research was to tissue engineer the motoneuron to muscle segment of the stretch reflex arc circuit utilizing micro-fabrication, interface design and defined medium formulations. In order to address this central theme, the following hypothesis has been proposed. The first part of the hypothesis is that microfabrication technology, interface design and defined medium formulations can be effectively combined to tissue engineer the motoneuron to muscle segment of the stretch reflex arc. The second part of the hypothesis is that different growth factors, hormones, nanoparticles, neurotransmitters and synthetic substrate can be optimally utilized to regenerate the adult mammalian spinal cord neurons so as to replace the embryonic motoneurons in the stretch reflex tissue engineered construct with adult motoneurons. In this body of work, the different tissue engineering strategies and technologies have been addressed to enable the recreation of a in vitro cellular prototype of the stretch reflex circuit with special emphasis on building the motoneuron to muscle segment of the circuit. In order to recreate the motoneuron to muscle segment of the stretch reflex arc, a successful methodology to tissue engineer skeletal muscle and motoneuron was essential. Hence the recreation of the motoneuron to muscle segment of the stretch reflex circuit was achieved in two parts. In the part 1 (Chapters 2-5), the challenges in skeletal muscle tissue engineering were examined. In part 2 (Chapters 6-7), apart from tissue engineering the motoneuron to muscle segment, the real time synaptic activity between motoneuron and muscle segment were studied using extensive video recordings. In part 3 (Chapters 8-10), an innovative attempt had been made to tissue engineer the adult mammalian spinal cord neurons so that in future this technology could utilized to replace the embryonic neurons used in the stretch reflex circuit with adult neurons. The advantage of using adult neurons is that it provides a powerful tool to study older neurons since these neurons are more prone to age related changes, neurodegenerative disorders and injuries. This study has successfully demonstrated the recreation of the motoneuron to muscle segment of the stretch reflex arc and further demonstrated the successful tissue engineering strategies to grow adult mammalian spinal cord neurons. The different cell culture technologies developed in these studies could be used as powerful tools in nerve-muscle tissue engineering, neuro-prosthetic devices and in regenerative medicine.
Show less - Date Issued
- 2008
- Identifier
- CFE0002501, ucf:47679
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002501
- Title
- A PREDICTIVE MODEL FOR BENCHMARKING ACADEMIC PROGRAMS (PBAP) USING U.S. NEWS RANKING DATA FOR ENGINEERING COLLEGES OFFERING GRADUATE PROGRAMS.
- Creator
-
Chuck, Lisa, Tubbs, LeVester, University of Central Florida
- Abstract / Description
-
Improving national ranking is an increasingly important issue for university administrators. While research has been conducted on performance measures in higher education, research designs have lacked a predictive quality. Studies on the U.S. News college rankings have provided insight into the methodology; however, none of them have provided a model to predict what change in variable values would likely cause an institution to improve its standing in the rankings. The purpose of this study...
Show moreImproving national ranking is an increasingly important issue for university administrators. While research has been conducted on performance measures in higher education, research designs have lacked a predictive quality. Studies on the U.S. News college rankings have provided insight into the methodology; however, none of them have provided a model to predict what change in variable values would likely cause an institution to improve its standing in the rankings. The purpose of this study was to develop a predictive model for benchmarking academic programs (pBAP) for engineering colleges. The 2005 U.S. News ranking data for graduate engineering programs were used to create a four-tier predictive model (pBAP). The pBAP model correctly classified 81.9% of the cases in their respective tier. To test the predictive accuracy of the pBAP model, the 2005 U.S .News data were entered into the pBAP variate developed using the 2004 U.S. News data. The model predicted that 88.9% of the institutions would remain in the same ranking tier in the 2005 U.S. News rankings (compared with 87.7% in the actual data), and 11.1% of the institutions would demonstrate tier movement (compared with an actual 12.3% movement in the actual data). The likelihood of improving an institution's standing in the rankings was greater when increasing the values of 3 of the 11 variables in the U.S. News model: peer assessment score, recruiter assessment score, and research expenditures.
Show less - Date Issued
- 2005
- Identifier
- CFE0000576, ucf:46422
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000576
- Title
- EXPRESSION OF GAL/GALNAC LECTIN OF ENTAMOEBA HISTOLYTICA IN TRANSGENIC CHLOROPLASTS TO DEVELOP A VACCINE FOR AMEBIASIS.
- Creator
-
Chebolu, Seethamahalakshmi, Daniell, Henry, University of Central Florida
- Abstract / Description
-
Amebiasis, also defined as invasive intestinal and extra intestinal amebiasis, is caused by Entameoba histolytica, an invasive protozoan parasite. World Health Organization (WHO) has reported that approximately 50 million people are infected each year causing an estimated 40 to 100 thousand deaths annually. Entameoba histolytica ranks only second to malaria as a protozoan cause of death. Amebiasis occurs world wide but people living in Central and South America, Africa and Asia are the...
Show moreAmebiasis, also defined as invasive intestinal and extra intestinal amebiasis, is caused by Entameoba histolytica, an invasive protozoan parasite. World Health Organization (WHO) has reported that approximately 50 million people are infected each year causing an estimated 40 to 100 thousand deaths annually. Entameoba histolytica ranks only second to malaria as a protozoan cause of death. Amebiasis occurs world wide but people living in Central and South America, Africa and Asia are the majority to suffer from morbidity and mortality. The enteric parasite has no zoonotic reservoirs and insect vectors for its transmission and infects humans and non-human primates. Therefore, anti-amebic vaccine could completely eradicate the disease. Entamoeba histolytica invades tissue and causes the disease in series of events. The disease is caused when the cyst form of the parasite is ingested with contaminated food or water. After excysting in the small intestine to form the trophozoite, the parasite adheres to the colonic mucus and epithelial cells through interaction of Gal/GalNAc lectin, an amebic surface adhesin with the host glycoconjugates. The parasite then secrets the proteolytic enzymes that disrupt the intestinal mucus and epithelial barrier facilitating tissue penetration. The trophozoite then kills the host epithelial and immune cells. Also, it resists the host's immune response causing the prolonged infection called the invasive amebiasis and causes colon or liver abscess. The symptoms include gradual onset of abdominal pain, diarrhea and bloody stools. Also, it can form cysts that are excreted with stools to start new cycle. The parasite recognition of the host glycoconjugates plays an important role in the pathogenesis. Therefore, the Gal/GalNAc lectin could be a possible vaccine candidate. The Gal/GalNAc lectin is composed of a 260-kDa heterodimer of disulfide-linked heavy (170 kDa) and light (35 kDa) subunits, which is non-covalently associated with an intermediate sub-unit of 150 kDa. The only recognized Carbohydrate recognition domain (CRD) was found in the heavy sub-unit. The CRD of the lectin is the potential target for colonization blocking vaccines and drugs. Preliminary studies have shown that the recombinant fragments of cysteine-rich region of LecA (lectin) containing the CRD (carbohydrate recognition domain) of the GalNAc lectin conferred protection against amebiasis. Therefore, production of LecA in plants using chloroplast genetic engineering would result in low cost vaccine because of high expression levels of vaccine antigens, and elimination of the cold-chain (low temperature, storage & transportation), hospitals and health professionals for their delivery. The LecA protein was expressed in transgenic chloroplasts of Nicotiana tabacum var. Petit havana by transforming the chloroplast genome using the LecA gene (1755 bp) by homologous recombination. The pLD-CtV has trnI and trnA genes that are used as flanking sequences for homologous recombination and the constitutive 16s rRNA promoter to regulate transcription. The aadA gene conferring spectinomycin resistance has been used for selection and gene10 regulatory sequence from T7 bacteriophage to enhance translation. The chloroplast integration of LecA was confirmed by PCR and Southern blot analysis. The expression of LecA protein in transgenic chloroplasts was analyzed by immunoblot analysis using anti-LecA antibodies. Maximum expression levels of LecA up to 6.3 % of the total soluble protein were observed in the old leaves. The evaluation of the immune response in animal model is underway. This is the first report of expression of LecA in a plant system.
Show less - Date Issued
- 2005
- Identifier
- CFE0000511, ucf:46467
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000511
- Title
- MULTIGENE METABOLIC ENGINEERING VIA THE CHLOROPLAST GENOME.
- Creator
-
Ruiz, Oscar Nemesio, Daniell PD, Henry h., University of Central Florida
- Abstract / Description
-
The vast majority of valuable agronomic traits are encoded polygenetically. Chloroplast genetic engineering offers an alternate approach to multigene engineering by allowing the insertion of entire pathways in a single transformation event, while being an environmentally friendly approach.Stable integration into the chloroplast genome and transcription of the phaA gene coding for b-ketothiolase was confirmed by Southern and northern blots. Coomassie-stained gel and western blots confirmed...
Show moreThe vast majority of valuable agronomic traits are encoded polygenetically. Chloroplast genetic engineering offers an alternate approach to multigene engineering by allowing the insertion of entire pathways in a single transformation event, while being an environmentally friendly approach.Stable integration into the chloroplast genome and transcription of the phaA gene coding for b-ketothiolase was confirmed by Southern and northern blots. Coomassie-stained gel and western blots confirmed hyperexpression of b-ketothiolase in leaves and anthers, with high enzyme activity. The transgenic lines were normal except for the male sterile phenotype, lacking pollen. Scanning electron microscopy revealed a collapsed morphology of the pollen grains. Transgenic lines followed an accelerated anther developmental pattern, affecting their development and maturation, resulting in aberrant tissue patterns. Abnormal thickening of the outer wall, enlarged endothecium and vacuolation, decreased the inner space of the locules, affecting pollen grain and resulted in the irregular shape and collapsed phenotype. Reversibility of the male sterility phenotype was achieved by exposing the plants to continuous illumination, producing viable pollen and copious amounts of seeds. This is the first report of engineered cytoplasmic male sterility and offers a new tool for transgene containment for both nuclear and organelle genomes.Detailed characterization of transcriptional, posttranscriptional and translational processes of heterologous operons expressed via the chloroplast genome is reported here. Northern blot analyses performed on chloroplast transgenic lines harboring seven different heterologous operons, revealed that in most cases, only polycistronic mRNA was produced or polycistrons were the most abundant form and that they were not processed into monocistrons. Despite such lack of processing, abundant foreign protein accumulation was detected in these transgenic lines. Interestingly, a stable secondary structure formed from a heterologous bacterial intergenic sequence was recognized and efficiently processed, indicating that the chloroplast posttranscriptional machinery can indeed recognize sequences that are not of chloroplast origin, retaining its prokaryotic ancestral features. Processed and unprocessed heterologous polycistrons were quite stable even in the absence of 3'UTRs and were efficiently translated. Unlike native 5' UTRs, heterologous secondary structures or 5'UTRs showed efficient translational enhancement independent of any cellular control. Finally, we observed abundant read-through transcription in the presence of chloroplast 3'UTRs. Such read-through transcripts were efficiently processed at introns present within native operons. Addressing questions about polycistrons, as well as the sequences required for their processing and transcript stability are essential for future approaches in metabolic engineering.Finally, we have shown phytoremediation of mercury by engineering the mer operon via the chloroplast genome under the regulation of chloroplast native and heterologous 5'UTRs. These transgenenic plants hyperexpress were able to translate MerA and MerB enzymes to levels detectable by coomassie stained gel. The knowledge acquired from these studies offer guidelines for engineering multigene pathways via the chloroplast genome.
Show less - Date Issued
- 2004
- Identifier
- CFE0000115, ucf:46206
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000115
- Title
- DEVELOPMENT OF THERMALLY PROCESSED NANOCOMPOSITES WITH CONTROLLED SURFACES.
- Creator
-
Georgieva, Petya, Seal, Sudipta, University of Central Florida
- Abstract / Description
-
The ever increasing need for technology development requires the integration of inexpensive, light weight and high strength materials which are able to meet the high standards and specifications for various engineering applications. The intention of this work is to show that the suitable material selection and the utilization of plasma spray processing can be of potential interest to a large number of industrial, biomedical and everyday life applications. This research demonstrates also that...
Show moreThe ever increasing need for technology development requires the integration of inexpensive, light weight and high strength materials which are able to meet the high standards and specifications for various engineering applications. The intention of this work is to show that the suitable material selection and the utilization of plasma spray processing can be of potential interest to a large number of industrial, biomedical and everyday life applications. This research demonstrates also that plasma processing is a promising engineering tool for multifunctional coatings and near-net-shape manufacturing. Further, the theoretical and experimental results are combined in order to explain the mechanisms behind nanostructure retention and enhanced properties. Proper design of experiments, an appropriate material selection and experimental methodology are discussed herein. The experimental conditions were optimized in order to achieve the best materials properties according to their explicit properties and functions. Specific materials were consolidated according to their prospective performance and applications: 1) Plasma spraying of nano-Ceria-stabilized Zirconia free form part for stem cells scaffolds, 2) Plasma spraying of FeCrAlY on Ti-alloy plate, additionally coated with nano-size Hydroxyapatite for bone tissue engineering, 3) Wire-arc spraying of nano-based steel wires for aerospace and automotive applications. The performance and characteristics of all of the developed coatings and free-form-parts are evaluated using state-of-the art characterization techniques.
Show less - Date Issued
- 2006
- Identifier
- CFE0001153, ucf:46871
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001153
- Title
- EFFECTS OF BINARY SOLVENT SYSTEM ON MORPHOLOGY OF PARTICLES.
- Creator
-
Besana, Patrick, Deng, Weiwei, University of Central Florida
- Abstract / Description
-
Recent advancements in cancer research has led to the synthesis of a new drug known as docetaxel. Meant to replace paclitaxel, its more natural counterpart whose ingredients are difficult to obtain, the drug is known to effectively treat a wide array of cancers, including breast cancer, ovarian cancer, and prostate cancer. The establishment of a synthetic alternative to paclitaxel has increased its bioavailability, thereby lowering the cost needed to utilize the drug. Still, the limiting...
Show moreRecent advancements in cancer research has led to the synthesis of a new drug known as docetaxel. Meant to replace paclitaxel, its more natural counterpart whose ingredients are difficult to obtain, the drug is known to effectively treat a wide array of cancers, including breast cancer, ovarian cancer, and prostate cancer. The establishment of a synthetic alternative to paclitaxel has increased its bioavailability, thereby lowering the cost needed to utilize the drug. Still, the limiting factor in minimizing costs is the method in which the drug is processed. Current methods in drug processing have their limitations, which include the introduction of impurities and a low effective yield due to poor powder geometry. Thus, the goal of this study looks to explore a new way to process the drug in a more efficient manner. In this study, a new method for processing docetaxel is explored on in great detail. A more direct method of using electrospray deposition is utilized for the creation of monodisperse nanoparticles, with the main intention of increasing the efficiency at which the drug is processed and prepared for drug delivery to the patient by means of injection. A key feature in electrospray deposition is its ability to produce droplets that are sized homogenously. These droplets eventually evaporate at homogenous rates. These two concepts have been exploited to consistently produce nanoparticles of the cancer drug, which is made possible by the fact that the minimal variation in droplet sizes has easily translated to minimal variation in dry particle sizes. Compared to other methods of drug processing, one other benefit that electrospray deposition conveys is that through evaporation, virtually all impurities and unwanted foreign material are eliminated. Moreover, a binary solvent system is investigated in more detail in this study, so as to determine its effects on both the evaporation of the solvent and the diffusion of the drug into nanoparticles. From there, material and geometric properties of the electrospray nozzle were explored upon in great detail, with the main goal of being able to produce a cone jet that consistently dissociates into monodisperse droplets. At the same time, controllable properties of the electrospray atomizer were investigated and continuously modified. Modifications in both the components of the solution and the operating temperature were also considered to enhance both the electrospray deposition process and the geometry of the particles. Scanning electron microscopy (SEM) characterization is continuously utilized to determine suitability of results obtained in experiments. Ultimately, the goal of this study is to determine the ideal conditions (solvent ratios, flow rate, operating temperature, electrospray atomizer nozzle configurations, etc.) in which spherical docetaxel particles sized at 100-200 nm can be produced.
Show less - Date Issued
- 2015
- Identifier
- CFH0004872, ucf:45412
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004872
- Title
- ARE BUILDING DESIGN RATING SYSTEMS EFFECTIVE TOWARDS THE GOAL OF SUSTAINABILITY IN THE DESIGN AND CONSTRUCTION OF PUBLIC AND PRIVATE BUILDINGS AND HOW WILL NEW ENERGY PERFORMANCE AND SUSTAINABLE DESIGN REQUIREMENTS AFFECT THE PROFESSIONAL LIABILITY OF BUILDING DESIGN PROFESSIONALS?.
- Creator
-
Transue, Samuel, Milon, Abby, University of Central Florida
- Abstract / Description
-
The following paper will explore the future of sustainable building practices as it relates to building design rating systems and whether building design rating systems are effective in conserving energy and resources in the construction of new buildings. This paper will begin by highlighting some of the general principles behind sustainable design practices, and the challenges of determining if building design rating systems are utilized effectively towards the goal of sustainability. In...
Show moreThe following paper will explore the future of sustainable building practices as it relates to building design rating systems and whether building design rating systems are effective in conserving energy and resources in the construction of new buildings. This paper will begin by highlighting some of the general principles behind sustainable design practices, and the challenges of determining if building design rating systems are utilized effectively towards the goal of sustainability. In addition, the paper will highlight issues specific to ongoing litigation in Gifford v. U.S. Green Building Council and allegations made within the lawsuit that question the methodology and efficacy of building design rating systems. How political and ideological influences have propelled sustainability practices into the mainstream, and to what extent government is and should be involved in regulating building design rating systems will also be explored. Lastly, how will new energy performance and sustainable design methodologies, which are now being required in the law, affect the professional liability of building design professionals in the future?
Show less - Date Issued
- 2011
- Identifier
- CFH0004066, ucf:44788
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004066
- Title
- INFLUENCE MAP METHODOLOGY FOR EVALUATING SYSTEMIC SAFETY ISSUES.
- Creator
-
Barth, Timothy, Pet-Armacost, Julia, University of Central Florida
- Abstract / Description
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"Raising the bar" in safety performance is a critical challenge for many organizations. Contributing factor taxonomies organize information on why accidents occur. Therefore, they are essential elements of accident investigations and safety reporting systems. Organizations must balance efforts to identify causes of specific accidents with efforts to evaluate systemic safety issues in order to become more proactive about improving safety. This research successfully addressed two problems: (1)...
Show more"Raising the bar" in safety performance is a critical challenge for many organizations. Contributing factor taxonomies organize information on why accidents occur. Therefore, they are essential elements of accident investigations and safety reporting systems. Organizations must balance efforts to identify causes of specific accidents with efforts to evaluate systemic safety issues in order to become more proactive about improving safety. This research successfully addressed two problems: (1) limited methods and metrics exist to support the design of effective taxonomies, and (2) influence relationships between contributing factors are not explicitly modeled within a taxonomy. The primary result of the taxonomic relationship modeling efforts was an innovative "dual role" contributing factor taxonomy with significant improvements in comprehensiveness and diagnosticity over existing taxonomies. The influence map methodology was the result of a unique graphical and analytical combination of the dual role taxonomy and influence relationship models. Influence maps were developed for several safety incidents at Kennedy Space Center. An independent assessment was conducted by a team of experts using the new dual role taxonomy and influence chain methodology to evaluate the accuracy and completeness of contributing factors identified during the formal incident investigations. One hundred and sixteen contributing factors were identified using the influence map methodology. Only 16% of these contributing factors were accurately identified with traditional tools, and over half of the 116 contributing factors were completely unaddressed by the findings and recommendations of the formal incident reports. The new methodology is being applied to improve spaceport operations and enhance designs of future NASA launch systems.
Show less - Date Issued
- 2006
- Identifier
- CFE0001274, ucf:46928
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001274
- Title
- THE THERMODYNAMICS OF PLANETARY ENGINEERING ON THE PLANET MARS.
- Creator
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Barsoum, Christopher, Lin, Kuo-Chi, University of Central Florida
- Abstract / Description
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Mars is a potentially habitable planet given the appropriate planetary engineering efforts. In order to create a habitable environment, the planet must be terraformed, creating quasi-Earth conditions. Benchmarks for minimum acceptable survivable human conditions were set by observing atmospheric pressures and temperatures here on Earth that humans are known to exist in. By observing a positive feedback reaction, it is shown how the sublimation of the volatile southern polar ice cap on Mars...
Show moreMars is a potentially habitable planet given the appropriate planetary engineering efforts. In order to create a habitable environment, the planet must be terraformed, creating quasi-Earth conditions. Benchmarks for minimum acceptable survivable human conditions were set by observing atmospheric pressures and temperatures here on Earth that humans are known to exist in. By observing a positive feedback reaction, it is shown how the sublimation of the volatile southern polar ice cap on Mars can increase global temperatures and pressures to the benchmarks set for minimum acceptable survivable human conditions. Given the degree of uncertainty, utilization of pressure scale heights and the Martin extreme terrain were used to show how less than desirable conditions can still produce results where these benchmarks can be met. Methods for obtaining enough energy to sublimate the southern polar ice cap were reviewed in detail. A new method of using dark, carbonaceous Martian moon material to alter the overall average albedo of the polar ice cap is proposed. Such a method would increase Martian energy efficiency. It is shown that by covering roughly 10% of the Martian polar ice cap with dark carbonaceous material, this required energy can be obtained. Overall contributions include utilization of pressure scale heights at various suggested settlement sites, as well as polar albedo altering as a method of planetary engineering. This project serves as a foundational work for long term solar system exploration and settlement.
Show less - Date Issued
- 2014
- Identifier
- CFH0004540, ucf:45225
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004540
- Title
- Seismic Response of Moment Resisting Frames Coupled with Rocking Walls.
- Creator
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Aghagholizadeh, Mehrdad, Makris, Nicos, Catbas, Necati, Mackie, Kevin, Kauffman, Jeffrey L., University of Central Florida
- Abstract / Description
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This study investigates the inelastic response of yielding structures coupled with rocking walls. This topic is of major significance in the design of tall moment-resisting buildings, since during recent major earthquakes several tall, moment-resisting frames that had been designed in an accordance to the existing seismic code provisions, exhibited a weak-story failure. Utilization of this structural system can help reducing maximum story drifts, prevents weak story failure and minimize...
Show moreThis study investigates the inelastic response of yielding structures coupled with rocking walls. This topic is of major significance in the design of tall moment-resisting buildings, since during recent major earthquakes several tall, moment-resisting frames that had been designed in an accordance to the existing seismic code provisions, exhibited a weak-story failure. Utilization of this structural system can help reducing maximum story drifts, prevents weak story failure and minimize residual deformation of the structure. This study first examines different configurations of both stepping rocking walls and pinned rocking walls that have been reported in the literature.Next, effect of additional vertical tendons or vertical damping devices in maximum response of the system is investigated. This research first derives the nonlinear equations of motion of a yieldingoscillator coupled with a rocking wall and the dependability of the one-degree of freedom idealization is validated against the nonlinear time-history response analysis of a 9-story moment-resisting frame coupled with a rocking wall. This research finally concludes that, stepping wall suppresses peak and permanent displacements, with the heavier wall being most effective. In contrast, the pinned rocking wall increases in general the peak inelastic displacements and the permanent displacements. While, the coupling of weak building frames with rocking walls is an efficient strategy that controls inelastic deformations by enforcing a uniform interstory-drift distribution, therefore, avoiding mid-story failures, the study shows that even for medium-rise buildings the effect of vertical tendons on the inelastic structural response is marginal, except for increasing the vertical reactions at the pivoting points of the rocking wall. Additionally, The SDOF idealization presented in this study compares satisfactory with finite-element analysis of a 9-story steel SAC building coupled with a stepping rocking wall; therefore, the SDOF idealization can be used with confidence for preliminary analysis and design.
Show less - Date Issued
- 2018
- Identifier
- CFE0007301, ucf:52157
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007301
- Title
- On the design and performance of cognitive packets over wired networks and mobile ad hoc networks.
- Creator
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Lent, Marino Ricardo, Gelenbe, Erol, Engineering and Computer Science
- Abstract / Description
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University of Central Florida College of Engineering Thesis; This dissertation studied cognitive packet networks (CPN) which build networked learning systems that support adaptive, quality of service-driven routing of packets in wired networks and in wireless, mobile ad hoc networks.
- Date Issued
- 2003
- Identifier
- CFR0001374, ucf:52931
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0001374
- Title
- Development of a Functional In Vitro 3D Model of the Peripheral Nerve.
- Creator
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Anderson, Wesley, Lambert, Stephen, Hickman, James, Fernandez-Valle, Cristina, Willenberg, Bradley, University of Central Florida
- Abstract / Description
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Peripheral neuropathies, affect approximately 20 million people in the United States and are often a complication of conditions such as diabetes that can result in amputation of affected areas such as the feet and toes. In vitro methodologies to facilitate the understanding and treatment of these disorders often lack the cellular and functional complexity required to accurately model peripheral neuropathies. In particular, they are often 2-D and functional readouts, such as electrical...
Show morePeripheral neuropathies, affect approximately 20 million people in the United States and are often a complication of conditions such as diabetes that can result in amputation of affected areas such as the feet and toes. In vitro methodologies to facilitate the understanding and treatment of these disorders often lack the cellular and functional complexity required to accurately model peripheral neuropathies. In particular, they are often 2-D and functional readouts, such as electrical activity, are limited to cell bodies thereby limiting the understanding of axonopathy which often characterizes these disorders. We have developed a functional 3-D model of peripheral nerves using a capillary alginate gel (Capgel(TM)), as a scaffold. We hypothesize that: 1) The unique microcapillary structure of Capgel(TM) allows for the modeling of the 3-D microstructure of the peripheral nerve, and 2) That axon bundling in the capillary allows for the detection of axonal electrical activity. In our initial studies, we demonstrate that culturing embryonic dorsal root ganglia (DRG) within the Capgel(TM) environment allows for the separation of cell bodies from axons and recreates many of the features of an in vivo peripheral nerve fascicle including myelinated axons and the formation of a rudimentary perineurium. To develop functionality for this model we have integrated the DRG Capgel(TM) culture with a microelectrode array to examine spontaneous activity in axon bundles, which we find demonstrates superiority to other widely used 2-D models of the same tissue. Furthermore, by analyzing the activity on individual electrodes, we were able to record action potentials from multiple axons within the same bundle indicating a functional complexity comparable to that observed in fascicles in vivo. This 3D model of the peripheral nerve can be used to study the functional complexities of peripheral neuropathies and nerve regeneration as well as being utilized in the development of novel therapeutics.
Show less - Date Issued
- 2018
- Identifier
- CFE0007150, ucf:52303
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007150
- Title
- INCREMENTAL LIFECYCLE VALIDATION OF KNOWLEDGE-BASED SYSTEMS THROUGH COMMONKADS.
- Creator
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Batarseh, Feras, Gonzalez, Avelino, University of Central Florida
- Abstract / Description
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This dissertation introduces a novel validation method for knowledge-based systems (KBS).Validation is an essential phase in the development lifecycle of knowledge-based systems. Validation ensures that the system is valid, reliable and that it reflects the knowledge of the expert and meets the specifications. Although many validation methods have been introduced for knowledge-based systems, there is still a need for an incremental validation method based on a lifecycle model. Lifecycle...
Show moreThis dissertation introduces a novel validation method for knowledge-based systems (KBS).Validation is an essential phase in the development lifecycle of knowledge-based systems. Validation ensures that the system is valid, reliable and that it reflects the knowledge of the expert and meets the specifications. Although many validation methods have been introduced for knowledge-based systems, there is still a need for an incremental validation method based on a lifecycle model. Lifecycle models provide a general framework for the developer and a mapping technique from the system into the validation process. They support reusability, modularity and offer guidelines for knowledge engineers to achieve high quality systems. CommonKADS is a set of models that helps to represent and analyze knowledge-based systems. It offers a de facto standard for building knowledge-based systems. Additionally, CommonKADS is a knowledge representation-independent model. It has powerful models that can represent many domains. Defining an incremental validation method based on a conceptual lifecycle model (such as CommonKADS) has a number of advantages such as reducing time and effort, ease of implementation when having a template to follow, well-structured design, and better tracking of errors when they occur. Moreover, the validation method introduced in this dissertation is based on case testing and selecting an appropriate set of test cases to validate the system. The validation method defined makes use of results of prior test cases in an incremental validation procedure. This facilitates defining a minimal set of test cases that provides complete and effective system coverage. CommonKADS doesn't define validation, verification or testing in any of its models. This research seeks to establish a direct relation between validation and lifecycle models, and introduces a validation method for KBS embedded into CommonKADS.
Show less - Date Issued
- 2011
- Identifier
- CFE0003621, ucf:48879
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003621
- Title
- OPTIMIZED MARKET INTRODUCTION OF LARGE CAPITAL PRODUCTS WITH LONG DEVELOPMENT AND LEARNING CYCLES.
- Creator
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Lembcke, Antje, Malone, Linda, University of Central Florida
- Abstract / Description
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Any product sold is expected to be reliable and available when the customer wants to operate it. Companies that produce large capital products (LCP), such as rockets, satellites, or large gas turbines to generate electrical energy, tend to shy away from extending their testing and validation method above the requirements by law, mainly due to the very high costs of each additional test and the uncertain return on investment. This research shows that todayÃÂ's state of...
Show moreAny product sold is expected to be reliable and available when the customer wants to operate it. Companies that produce large capital products (LCP), such as rockets, satellites, or large gas turbines to generate electrical energy, tend to shy away from extending their testing and validation method above the requirements by law, mainly due to the very high costs of each additional test and the uncertain return on investment. This research shows that todayÃÂ's state of the art validation methods for LCP, required by law, or suggested in literature, and adapted by these industries, are not capable of capturing all significant failure modes (or even enough failure modes), with the consequence that the subsequently sold commercial products will still experience failures with significant effects on product reliability, and subsequently on the companiesÃÂ' bottom line earnings projections. The research determines the type of data (significant variables) necessary to correlate a companyÃÂ's validation policy to product failures after commercialization, and predicts the financial impact of the current validation policy on the companyÃÂ's profitability. A systems dynamics model to assess a company's testing policy is developed and an optimized product validation plan is suggested, and its impact on a companyÃÂ's profitability is demonstrated through simulation. A generic methodology is derived and its viability is illustrated using a specific product and a dynamic model developed with data available to the researcher. The generic method can be applied by any company to develop its own model for optimizing product reliability prior to market introduction.
Show less - Date Issued
- 2010
- Identifier
- CFE0003413, ucf:48404
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003413
- Title
- CONTRIBUTIONS BY INDIVIDUAL AND GROUP STRATEGIES FOR ORGANIZATIONAL LEARNING IN ARCHITECTURAL, ENGINEERING, AND CONSTRUCTION FIRMS.
- Creator
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Beaver, Robert, Kotnour, Timothy, University of Central Florida
- Abstract / Description
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Organizations with multiple operating requirements require support functions to assist in execution of strategic goals. This effort, in turn, requires management of engineering activities in control of projects and in sustaining facilities. High level strategies include employing engineering support that consists of a project management function encompassing technical and managerial disciplines. The architecture/engineering, and construction office (AEC) is the subject of this research....
Show moreOrganizations with multiple operating requirements require support functions to assist in execution of strategic goals. This effort, in turn, requires management of engineering activities in control of projects and in sustaining facilities. High level strategies include employing engineering support that consists of a project management function encompassing technical and managerial disciplines. The architecture/engineering, and construction office (AEC) is the subject of this research. Engineering and construction oriented organizations have experienced challenges to their abilities to learn and grow. This has potential detrimental implications for these organizations if support functions cannot keep pace with changing objectives and strategy. The competitive nature and low industry margins as well as uniqueness of projects as challenges facing engineering and construction. The differentiated nature of projects tasks also creates a need for temporary and dedicated modes of operation and thereby tends to promote highly dispersed management practices that do not dovetail very well with other organizational processes. Organizational learning is a means to enhance and support knowledge management for improving performance. The problem addressed through this research is the gap between desired and achieved individual and group learning by members of the AEC, and the members' abilities to distinguish between the need for adaptive learning or innovation. This research addresses learning by individuals and groups, and the strategies employed through an empirical study (survey). A conceptual model for organizational learning contributions by individuals and groups is presented and tested for confirmation of exploitive or explorative learning strategies for individuals, and directions composed of depth and breadth of learning. Strategies for groups are tested for internal or external search orientations and directions toward the single or multi-discipline unit. The survey is analyzed by method of principal components extraction and further interpreted to reveal factors that are correlated by Pearson product moment coefficients and tested for significance for potential relationships to factors for outcomes. Correlation across dependent variables prevented interpretation of the most significant factors for group learning strategies. However, results provide possible support for direction in supporting processes that promote networking among individuals and group structures that recognize the dual nature of knowledge - that required for technical competency and that required for success in the organization. Recommendations for practitioners include adjustments to knowledge acquisition direction, promoting external collaboration among firms, and provision of dual succession pathways through technical expertise or organizational processes for senior staff.
Show less - Date Issued
- 2009
- Identifier
- CFE0002682, ucf:48194
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002682