Phase and Amplitude Interferometry Based Radio Frequency Direction Finder

Direction finding (DF) systems have been around for decades, preceding WWII. The main function of these systems is to calculate the direction of arrival of an electromagnetic wave. There are many real-world applications which utilize direction finders and direction-finding techniques, from recreational “fox hunts” to military geolocation systems. The following approach for implementing a direction finding system revolves around the phase and amplitude of a signal that is being radiated at an unlicensed frequency of 2.45Ghz by an RF source. The system is comprised of an antenna array of 4 antennas which can be used receive the radiated signal. By comparing the amplitudes of the signal received by each antenna relative to each other, the quadrant from which the RF source is located in can be identified. By comparing the phase difference, 0° to +/- 180°, of the signal received by each antenna relative to each other, four possible directions can be calculated, one in each quadrant. Using the information discovered from comparing the phase and the amplitudes of the received signal at each antenna, the direction of the RF source can be found. The system runs the direction finding algorithm when the user commands it to from the graphical user interface (GUI), iterates it hundreds of times per second, and averages the found direction to reduce the effects of noise. The direction is then displayed on the GUI

Evaluation Of Hygroscopic Soil Amendments And Natural Freeze-Thaw Cycling To Accelerate The Mechanical Breakdown Of Artifacts In Demolition Site Soils

Many cities worldwide have areas of vacant land produced by building demolition. This open space has attracted great interest as a potential resource for green infrastructure, urban agriculture, and other purposes related to urban renewal. Unfortunately, rock-like artifacts (e.g. brick, mortar, concrete) are often present in great abundance in demolition site soils. These artifacts make the soil difficult to till, create obstacles for root penetration, and limit the soil’s water-holding capacity, infiltration and aeration. As an alternative to physical removal, this study was carried out to test the feasibility of using hygroscopic compounds as soil amendments to accelerate the mechanical disintegration of these artifacts in situ using natural freeze-thaw/wet-dry processes. Bench-scale tests were carried out to simulate 5 to 8 years of freeze-thaw/wet-dry cycling using dilute (3%) solutions of deicing salts (NaCl, CaCl2, salt mixture), fertilizer salts (MgSO4, Al2(SO4)2, (NH4)2SO4), and organic compounds (CH4N2O, C12H22O11, humate), which were added to a commercial topsoil containing clay bricks, concrete and sand-lime brick (simulating mortar). In the absence of visible disintegration, the effectiveness of each treatment was evaluated by uniaxial compression testing, and petrographic analysis of microporosity. Sand-lime brick showed visible disintegration by all treatments except CaCl2. The clay and concrete bricks generally lacked visible signs of deterioration, but showed a consistent decrease in compressive strength with all treatments. The greatest loss in strength (30%) occurred with the use of urea, sugar and the salt-mixture; however humate and all three sulfate compounds produced an average loss in strength of 20% or more. Petrographic analysis of concrete and clay bricks treated with NaCl and sugar showed an increase in microporosity which is inferred to be the cause of strength loss. Microporosity in the concrete was due to dislodging of calcite grains in the limestone aggregate, whereas that in clay bricks resulted from dislodging of silt-sized quartz temper. The treatments had no significant effect on pH, and electrical conductivity measurements showed that the salinities of all soils (except treated with the salt-mixture) were below a level detrimental to plant growth. These results support the hypothesis tested that hygroscopic compounds can be added as amendments to demolition site soils to accelerate and effect the mechanical breakdown of artifacts on a time scale (\u3c 10 years) short enough to be useful in the near future

Biochar Research and a Case Study in Kansas

As planet Earth's sustainability has become a foremost issue, different methods of prolonging sustainability have become prevalent in society, most prominently are alternative forms of energy and ways to help reduce the human impact on the environment. Another alternative that has become popular, mostly in the last decade, stems from decades of research conducted on ancient soils of the world, predominantly in the Amazon basin, soils of incredible fertility and mysterious properties that leave soil scientists wondering. The factor of greatest importance to these soils has been identified and termed biochar, the carbon remains of partially burned organic material. Biochar is now believed to have the potential not only help provide sustainability through fertile soils but also by providing relief from of the greatest threats to life on earth. This thesis will provide an outline of why biochar research is important, discuss all viable potentials for biochar and include the details and results of a case study in Kansas

The Effects of Rating Source, Rating Target, and Job Position on Ratings of Perceived Training Needs

Organizational investments in employee training and development have steadily increased over the past decade, with a recent estimate of $160 billion dollars annually. An important component of any training program is the subsequent training needs assessment (TNA), which provides critical information regarding who and what needs trained. Unfortunately, TNA research is severely limited compared to other aspects of the training process. The primary aim of the current study was to examine two important variables that can potentially influence TNA ratings beyond an actual need for training, the source and target of TNA ratings. Based on the assumptions of attribution theory, it was hypothesized that employees will generally underrate their own need for training in comparison to the TNA ratings that others ascribe to them (source effect), and the TNA ratings that they ascribe to others (target effect). The secondary aim of the current study was to content validate the TNA ratings obtained via a TNA, based on an employee’s job position as a supervisor or non-supervisor. Using extant competency models, it was hypothesized that supervisors will rate a greater need for training than non-supervisors in areas relevant to their role as a supervisor. To achieve these aims, the current study analyzed archival data from a needs assessment project of a municipality on the East Coast. A total of 1,271 participants provided data regarding their own training needs and the training needs of their supervisor/subordinates. Results indicated mix support for the effect of rating source and rating target on TNA ratings, and partial support for the differentiation of TNA ratings based on job position. Taken together, findings from this study provide insight into the effect of a self-serving bias in the context of TNA ratings, and provides practitioners with evidence based information regarding the measurement of training needs, such as who should provide TNA ratings (source) and if the TNA rating source(s) should rate themselves, someone else, or both (target). Additional evidence is presented regarding the validity of inferences made from TNA ratings obtained via a TNA based on differences in self-ascribed TNA ratings between supervisors and non-supervisors

Computational analysis of the sir mathematical model for the dengue fever

Dengue fever is a disease affecting people in more than 100 countries. Here we consider a host and vector model for the transmission of dengue fever. This SIR model consists of three compartments of susceptible, infective and removed for host (human) and two compartments of susceptible and infective for vector (dengue mosquitos). These five compartments yield five coupled nonlinear ordinary differential equations (ODEs). After non-dimensionalization, we have a system of three nonlinear ODEs. Reproductive number and two equilibrium points are calculated for various cases. Simulation is carried out for susceptible, infective and removed and the results are presented in graphical forms for various scenarios

A Scalable Unsegmented Multiport Memory for FPGA-Based Systems

On-chip multiport memory cores are crucial primitives for many modern high-performance reconfigurable architectures and multicore systems. Previous approaches for scaling memory cores come at the cost of operating frequency, communication overhead, and logic resources without increasing the storage capacity of the memory. In this paper, we present two approaches for designing multiport memory cores that are suitable for reconfigurable accelerators with substantial on-chip memory or complex communication. Our design approaches tackle these challenges by banking RAM blocks and utilizing interconnect networks which allows scaling without sacrificing logic resources. With banking, memory congestion is unavoidable and we evaluate our multiport memory cores under different memory access patterns to gain insights about different design trade-offs. We demonstrate our implementation with up to 256 memory ports using a Xilinx Virtex-7 FPGA. Our experimental results report high throughput memories with resource usage that scales with the number of ports

Investigating the removal of some pharmaceutical compounds in hospital wastewater treatment plants operating in Saudi Arabia

The concentrations of 12 pharmaceutical compounds (atenolol, erythromycin, cyclophosphamide, paracetamol, bezafibrate, carbamazepine, ciprofloxacin, caffeine, clarithromycin, lidocaine, sulfamethoxazole and Nacetylsulfamethoxazol (NACS)) were investigated in the influents and effluents of two hospital wastewater treatment plants (HWWTPs) in Saudi Arabia. The majority of the target analytes were detected in the influent samples apart from bezafibrate, cyclophosphamide, and erythromycin. Caffeine and paracetamol were detected in the influent at particularly high concentrations up to 75 and 12 ug/L, respectively. High removal efficiencies of the pharmaceutical compounds were observed in both HWWTPs, with greater than 90 % removal on average. Paracetamol, sulfamethoxazole, NACS, ciprofloxacin, and caffeine were eliminated by between >95 and >99 % on average. Atenolol, carbamazepine, and clarithromycin were eliminated by >86 % on average. Of particular interest were the high removal efficiencies of carbamazepine and antibiotics that were achieved by the HWWTPs; these compounds have been reported to be relatively recalcitrant to biological treatment and are generally only partially removed. Elevated temperatures and high levels of sunlight were considered to be the main factors that enhanced the removal of these compounds