Texas A&M University-Kingsville: AKM Digital Repository
Not a member yet
1689 research outputs found
Sort by
An investigation on the use of wind energy in the residential buildings in South Texas area
No full textToday, the increase in energy demand, the depletion of existing energy resources, and the environmental pollution resulting from fossil fuels make renewable energy sources mandatory. A large part of energy consumption from residential buildings has increased the need for renewable energy. In this study, wind energy was investigated as one of the renewable energy sources used in the residential buildings. The principles of active and passive utilization of wind energy in residential buildings were explained. Economic analysis was conducted by comparing the wind turbines with using AHP Method to the residential buildings. In Texas, the potential of wind energy available for use in residential buildings were analyzed since building wind energy does not reach the desired level, and wind energy application areas are predominantly in wind farms. The findings obtained in this study should be able to gain the attention from the residents who may be interested in using wind energy to substitute traditional energy supply. In this study, a guideline flowchart about how to use wind energy in residential areas was developed and discussed in details. Different scenarios were considered and compared when conducting the economic analysis, and the results show different payback period under different regions and with different types of wind turbines
Assessing the change in urban tree canopy cover, ecosystem services, streamflow and pollutants in Corpus Christi, Texas using I-tree applications
No full texti-Tree™ is an advanced peer-reviewed computing software suite developed by the USDA Forest Service, provides urban forestry analyses and ecosystem services and benefits assessments in urban and community areas. I used i-Tree Canopy™ and Hydro™, to produce a statistically validated estimate and assessment of the changes in stream flow runoff and pollutants based on changes of canopy cover of urban trees and changes of other land use types (shrubs, grasses, etc...) in Corpus Christi, Texas. i-Tree Canopy™ was used to examine
the changes in tree canopy cover and I found the tree cover increased from 9.12% to 9.93% (8.88% increased rate) from 2005 to 2014. The total ecosystem service benefits from tree canopy increased from 5.68 million for the same period. Using i-Tree Hydro TM, total stream flow runoff was found decreased from 506.66 million m3 to 210.47 million m3 as well as pollutants decreased from 72.75 million kg to 31.3 million kg. Based on the tree canopy and hydrology estimation of changes in past ten years, the objective was to predict the changes of total stream flow runoff and pollutants for the next ten years and to provide information to the city managers to assist urban green infrastructure decision making for city planning
Securing a network using dynamic guard deployment
No full textThis thesis analyzes the security of a network using the deployment of dynamic and distributed guards. A network in general consists of interconnected nodes. All the networks are found to fulfill certain key objectives that are vital to its members and the users. lt is important to provide suitable security to the network. There are a number of methods that have been developed to guard a network. But all these methods are computationally and economically expensive. All these methods propose to guard the network in a deterministic manner. This research proposes a probabilistic method to guard a particular network. The method proposed through this thesis is computationally and economically less expensive. Simulations for various combinations of guard and attacker have been carried out and an existence of a nash-equilibrium point has been proven to exist
An economic analysis of residential garbage collection operation: the case of the City of Kingsville, Texas
No full textThe collection of garbage requires a complicated logistic. In the earlier days garbage collection was carried out without understanding the demand and the route to pick up with a high cost. The purpose of this research is to find an efficient and effective way of garbage collection operations. This research, first, collected the data of current operation. The collected data were analyzed, and regression analysis was performed to check if the factors were related to garbage amount. This research proposed a new pattern of garbage collection operation. The purpose of this collection pattern was to assist in selecting work plan that minimizes the cost of operations, transportations, collection and disposals, subjects to various constraints. Finally, sensitivity analysis was performed to check possible ways of garbage collection operation. Result of this research show that the proposed method can save approximately 30% cost compared to current garbage collection operation
Synthesizing precompressed beams as bistable compliant mechanisms
No full textBistable mechanisms can be defined as mechanical systems which consist of two stable positions. The primary feature of this mechanism is that it does not need any external power to maintain the stable positions. Actuation is sufficient to shift the mechanism between the two stable positions. These stable positions do not need to be relative with the stored energy. Due to these features, they have many applications like switches, valves, self-closing gates, cabinet hinges, three ring binders, closures and clasps. The widely used flip-flop circuit is based on this principle. Compliant mechanisms transfer motion or energy. However, they gain some of their motion from
the movement of flexible members. Bistable compliant mechanisms achieve bistable behavior due to the elastic deflections of flexible elements instead of relative motions of kinematic joints in conventional rigid-body bistable mechanisms. In this thesis, a precompressed beam fixed at one end and joint at the other is used to develop a bistable compliant mechanism. This beam has two symmetric first mode buckled shapes. Torsional force provides the actuation for the beam to shift between the two buckled shapes. The two buckled shapes match the two stable equilibrium positions of bistable compliant mechanisms. The beam is modelled and analyzed in ANSYS for the aforementioned conditions. It is then manufactured as per the model and practical results are verified with the values obtained during the analysis of the beam
Pressure transient analysis in horizontal wells from traditional slug test
No full textConventionally. pressure transient analysis has been applied to vertical wells to obtain information about formation properties such as permeability, wellbore damage or stimulation, reservoir pressure and reservoir extent, and heterogeneities. Recently, horizontal wells began capturing an ever-increasing share of hydrocarbon production. They have been successfully used in reservoirs having natural vertical fractures, heavy oil, thin reservoirs, reservoirs present in inaccessible locations or in case of thick reservoirs having good vertical permeability. For this reason, this research is focused on extending the application of pressure transient analysis techniques successfully used for vertical wells to horizontal wells. The research illustrates application of Slug Test analysis techniques with type curves, traditionally used for vertical wells, for the case of horizontal wells. Formation properties such as permeability and skin factor have been computed and compared with the existing data on the wells to show that this proposed analysis technique can be successfully utilized for the case of horizontal wells.
Keywords: Pressure Transient Analysis, Horizontal wells, Slug Testin
Modelling and controls of a hexacopter
No full textMulticopters also known as drones, are becoming a common platform for the Unmanned Aerial Vehicles (UAVs). These devices are usually powered and propelled by multiple rotors placed in a geometric arrangement around the drone to allow control of the drone during flight. The main purpose of this research is to present the basic mathematical model for a Hexacopter, which is a special type of drone and to design a control scheme for the safe operation of the Hexacopter. In a hexacopter, three pairs of counter-rotating fixed blades are placed around the hexacopter. A Hexacopter is not as popular as a quadcopter but has several advantages over the quadcopter including vertical landing and takeoff, hovering, the capability of performing more complex operations over other aircraft. The hexacopter is controlled by adjusting the angular velocities of the rotors which are further controlled by a flight controller.
In this thesis, a mathematical model of a hexacopter is formulated to study the dynamic behavior of the Hexacopter. A suitable control is built for improving the hovering conditions and to control the attitude (Roll, Pitch, and Yaw) of the hexacopter. The multirotor is assumed as a rigid body, so the differential equations can be derived by Newton-Euler or the Euler-Lagrange equations. The mathematical model is designed by considering the Newton-Euler parametrization
Design and anaylsis of a pipe inspection robots
No full textIn-pipe inspection robots (IPIR) have been introduced to perform accurate and improved automated inspection of pipes. Several designs of IPIRs have been proposed in the literature to overcome issues related to inspection of complicated internal geometries. Tasks assigned to these robots have the added complexity of pipes changing shape and size, obstacle avoidance and steering, and safe operation with guaranteed retrieval of the robot. Although many types of the robot have been proposed and used, their drawbacks continue to include the inability to make turns and move in varied diameter sized pipe. This applied research proposes an improved design of an autonomous IPIR that can move through pipes of different orientations relative to gravity and of changing sizes and geometries to perform inspection tasks. The results expected from this work is to provide a platform for an IPIR that can be developed further to perform other complex and demanding tasks
Restoration of non-native grasslands and woody canopy selection by scaled quail
No full textNorthern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) have been declining for several decades. This decline has mostly been attributed to habitat loss and fragmentation. One avenue of habitat loss and fragmentation is the invasion of non-native grasses. In particular, buffelgrass (Pennisetum ciliare) and Old-World bluestems (Dichanthium annulatum) are of conservation concern in South Texas. These non-native grasses tend to form dense monotypic stands which reduce several aspects of quail habitat including forb abundance, insect abundance, and herbaceous species diversity. Restoration in areas dominated by these grasses has been attempted by other researchers but attempts have either been on a small scale (< 25 ha), unsuccessful, or short lived. The aim of this study was to assess the effectiveness of quail habitat restoration through repeated discing and herbicide application to remove non-natives and their seed, and the subsequent planting of ecotypic natives on a large scale (120 ha). I was successful in establishing native forbs and grasses and increased herbaceous species richness and diversity, which are important features of bobwhite habitat.
In addition to bobwhite habitat loss through non-native grass invasion, there is other threats to South Texas quail populations. A potential threat to scaled quail is brush management. Many researchers have designated scaled quail as a grassland bird based on research on a different subspecies and this may be misguiding management. I aimed to determine the appropriate scale and focal extent for resource selection for woody canopy cover by chestnut-bellied scaled quail and to identify selection bounds for metrics describing woody canopy cover using continuous selection functions. My results display that it was critical to use multiple focal extents and scales to describe resource selection for scaled quail, as selection varied by focal extent and scale. Scaled quail selected areas with woody canopy cover between around 40–85% on the second and third order, with medium amount of edge where patches were close together on the third order. My results suggest that brush management would not be beneficial to chestnut-bellied scaled quail in most cases and instead would add to the population decline
Nanomedicine for the treatment of pancreatic cancer
No full textNanotechnology has provided the possibility of delivering drugs to specific cells using nanoparticles. This helped in the synthesis of cancer targeted nanoparticles with a combination of two or more anti-cancer drugs and this targeted delivery is intended to reduce the side effects of the drugs with concomitant decreases in consumption and treatment expenses. Paclitaxel has been demonstrated with potent antitumor activity in many solid tumors. It is used to treat ovarian, breast, lung, pancreatic, non-small-cell lung cancer, head, neck and kidney cancer. The mechanism of action of paclitaxel involves interference with a normal depolymerization of microtubules during cell division. Vismodegib is also an anticancer drug and acts by inhibiting the hedgehog signaling pathway. In this project, human serum albumin (HSA) encapsulated with paclitaxel and vismodegib was developed. This platform offered new opportunity for developing anti-cancer nanomedicines that have different mechanism of action. The multi-components nanomedicine likely enhanced the efficacy and targeting specificity towards cancer cells. In this project, Paclitaxel and Vismodegib loaded Human serum albumin nanoparticles were synthesized using high sheer microfluidization technique. The drug-loading efficiency was increased by involving the anhydrous ethanol in the formulation process of paclitaxelvismodegib loaded albumin nanoparticles and drug release profile was determined by HPLC (high performance liquid chromatography) analysis. The prepared paclitaxel vismodegib loaded albumin nanoparticles were tested on the BxPC-3 and MiaPaCa-2 human pancreatic cancer cell lines using MTT assay and they showed a potent inhibition on these pancreatic cancer cell lines. The prepared nanoparticles provided a potential approach for the treatment of pancreatic cancer