The Enemy of my Enemy is my Friend… The Dynamics of Self Defense Forces in Irregular War: The Case of the Sons of Iraq

This paper assesses the effect that leveraging civilian defense force militias has on the dynamics of violence in civil war. We argue that the delegation of security and combat roles to local civilians shifts the primary targets of insurgent violence towards civilians, in an attempt to deter future defections, and re-establish control over the local population. This argument is assessed through an analysis of the Sunni Awakening and ancillary Sons of Iraq paramilitary program. The results suggest that at least in the Al-Anbar province of Iraq, the utilisation of the civilian population in counterinsurgent roles had significant implications for the targets of insurgent violence

Modeling of Circulation Zone and Shear Layers in Coaxial Injectors

Gaseous/gaseous hydrogen oxygen shear coaxial injectors were modeled to investigate grid parameters affecting solution and to determine if a steady state solution might exist if only one circulation zone was present. The General Equation Mesh Solver (GEMS), which implements the Reynolds Averaged Navier-Stokes equations with the k-ω turbulence model, was used to conduct the study. The Gambit grid generator was used to construct computational grids. Different grids were compared in a search for the optimum configuration while residual levels were monitored in search of a steady state solution

Denitrification kinetics in biological nitrogen and phosphorus removal activated sludge systems

In order to size the anoxic reactors in nutrient (N and P) removal activated sludge plants, it is essential to know the denitrification kinetics that are operative in such systems. To date, denitrification kinetics have been accurately defined only for systems that remove N alone; little research has been performed on denitrification in N and P removal plants

Impression Rating via Speed-Dating: How A Single Communication Event Can Alter Perceptions of Another Individual

The central purpose of this experiment is to scientifically test whether interpersonal communication influences individual perceptions in a dating environment. This study uses interaction appearance theory (IAT) as an empirical foundation for understanding the relationship between communicative outcomes and personal opinions. According to IAT, cognitive impressions of aesthetic appearance are highly fluid and vulnerable to the results of multiple social interactions (Albada, Knapp, & Theune, 2002). While most empirical investigations have provided additional support for this theory, no studies have tested whether IAT applies to various other social constructs. As such, this investigation was designed to address this gap in the literature as it explores the variables of physical attractiveness, intelligence, attitudinal similarity, and background similarity within an attraction-relevant atmosphere. A total of 104 undergraduate students at a large southeastern university engaged in speed-dating in order to ascertain if individual perceptions changed from pre-test to post-test. Study participants were recruited via numerous channels that included but were not limited to campus advertisements, class visits, and the student newspaper. Upon arrival, participants completed a 19-item blended scale that was created by the principal investigator. Next, study participants socially interacted with multiple opposite-sex speed-daters for a time period of three minutes per person. Before departure, the same 19-item blended scale was re-administered to all study participants. The collected data was then subjected to a series of statistical tests that included reliability analyses and 2 x 2 x 2 mixed factorial ANOVAs. Four central conclusions were drawn based on the evidence that emerged from the proposed hypotheses and research questions. First, interpersonal communication can be strategically used by females to increase their level of physical attractiveness. Second, a positive social interaction can make another person appear more intelligent. Third, perceptions of attitudinal similarity are influenced by a mere 180 seconds of communicative behavior. Fourth, the interaction appearance theory of communication can be applied to a single social interaction as well as to multiple other dependent and independent variables. When taken together, these results advance our practical understanding of both interpersonal attraction as well as cognitive processes

Biology and Control of Rice False Smut Caused by Ustilaginoidea virens (Teleomorph Villosiclava virens)

Rice false smut (FS), a disease caused by Ustilaginoidea virens (Cke.) Takahashi (1896), was first reported in northeastern Arkansas counties in 1997. The first objective of this research was to establish a collection of U. virens isolates from geographically diverse regions of Arkansas. Three U. virens isolates and chlamydospores from `Templeton\u27 and `Clearfield-151\u27 rice cultivars were used to determine the effects of temperature and pH on mycelial growth and germination. A nested-PCR protocol and histological methods were used to determine if U. virens infects and colonizes rice seedlings and spikelets on panicles. The sensitivity of three U. virens isolates was tested to analyze the inhibition of mycelial growth in vitro and to establish inhibitory concentrations to six technical and five analytical grade fungicides. Field and greenhouse tests were conducted to determine if fungicide seed treatments using technical grade fungicides could effectively reduce the incidence of U. virens rDNA in seedlings as measured by nested-PCR. Finally, field tests were conducted using fungicide seed treatments to control FS at two locations and disease was assessed by a visual disease assessment. We have an established collection of 190 isolates obtained from nine cultivars in seven counties of Arkansas, USA. Mycelial growth and germination of chlamydospores occurred between pH levels from 5.5 to 8.0. Mycelial growth and germination of chlamydospores occurred at temperatures from 18° to 34°C and from 18 to 26°C, respectively. Nested-PCR tests indicate the protocol is specific and sensitive for detecting U. virens in rice. Ribosomal DNA of U. virens was detected using nested-PCR from seedlings within three days after emergence from the soil and in 27.5 to 75% of spikelets in booted panicles before exsertion. Selected isolates of U. virens were sensitive to fungicides in-vitro but results from using nested-PCR in the greenhouse and field to screen seedlings for U. virens rDNA indicated a significant reduction in the incidence of U. virens in some seed treatments compared to controls. Seed treatments did not significantly reduce FS disease compared to controls in the field plots when measured by visual disease assessments

The Microstructural Annealing Response of Cold Gas Dynamically Sprayed Al 6061

The Cold-Gas Dynamic-Spray process also known as Cold Spray (CS) has been researched for three decades. The CS process is a solid-state deposition technique via supersonic velocity of powder particles at a temperature significantly below the melting point of the spray material. This thesis presents background on the overall CS process parameters, and additional information on the microstructural and mechanical properties of typical Cold Sprayed materials.This Thesis primarily presents a study on the microstructural annealing response of CS Al 6061. It should be noted that for this study, the term “annealing” is used in the sense of the classical metallurgical definition of annealing, and not a specific temper designation for the 6061 alloy. Cross sections of CS Al 6061 were imaged with a scanning electron microscope (SEM) in secondary electron (SE), backscatter electron (BSE), and electron backscatter diffraction (EBSD) imaging mode for quantitative and qualitative information on the grain size and orientation of the CS microstructure. The detailed SE, BSE and EBSD mode images present the grain size and grain orientation of the original powder, as received (AR) state and after heat treating at 200°C for 1 hour, 10 hours, and 100 hours. Three different regions, characterized with distinctly differing microstructures, are labeled as low, medium, and high deformation regions, and their microstructures, and evolving features are discussed. Vickers microhardness testing are performed to examine the differences in hardness values between different heat treatments, and for correlation with the level of deformation and grain refinement in the microstructure. SEM imaging was used in BSE mode to correlate microhardness variation to the different regions within the CS microstructure

A two-stage stochastic inventory management model for an intermodal trucking company

Master of ScienceDepartment of Industrial & Manufacturing Systems EngineeringAshesh SinhaIntermodal transportation faces several challenges due to uncertainty in rail schedules and customer demand. However, this uncertainty is rarely considered for determining asset management at the Intermodal rail yards. Typically, each Intermodal rail yard requires certain inventory of chassis to serve the demand for either empty containers or loaded containers. It is crucial for any transportation firm to optimally allocate and move chassis between rail ramps to overcome random demand. This thesis develops a two stage stochastic optimization model to determine the optimal allocation and repositioning decisions for chassis and empty boxes across the rail yards to minimize costs and meet service levels. The first stage formulation contains the initial chassis allocation decisions which are independent from random parameters in the following time periods. The second stage formulation determines the empty boxes and chassis repositining decisions for subsequent time periods when the random demand is realized. This thesis applies the L-Shaped Method to efficiently solve this problem. Using numerical experiments, this thesis analyzes the impact of system parameters on the run time performance. The thesis also analyzes the impact of initial chassis inventory and demand patterns on the optimal decisions. We observe that the higher initial inventory or demand at one location than the other results in an increase in the required repositioning moves and expected cost. Conversely, the model is fairly robust to how inventory and demand values are distributed between resource types

A feasibility study towards ultra-thin PV solar cell devices by MOCDV based on a p-i-n structure incorporating pyrite

FeSx layers were deposited onto aluminosilicate glass substrates over a temperature range of 180°C to 500°C using a horizontal AP-MOCVD reactor. Fe(CO)5 was used as the Fe source in combination with t-Bu2S2 or t-BuSH as S precursor to control the rate of reaction and film stoichiometry. The Fe and S partial pressures were kept at 7.5 x 103 and 3.0 mbar, giving a gas phase S/Fe ratio of 400. Reactions followed a non-Arrhenius relationship at higher temperatures. XRD revealed mixed FeSx phases in the layers, which consisted mainly of FeS and Fe1-xS. Post growth annealing of the FeSx films using S powder in a static argon atmosphere and temperatures ranging from 250°C to 400°C was carried out using a 30 minute soak time. Characterisation by XRD confirmed a transitional phase change to FeS2 for the S anneal at 400°C. These films were highly absorbing in the visible region of the solar spectrum, which extended into the NIR. Devices with a p-i-n structure were produced using either a sulphurised or non-sulphurised FeSx i-layer, and compared to p-n devices without an i-layer. A non-sulphurised p-i-n device had the best I-V results, which was attributed to reduced lateral inhomogeneity across the device relative to the thinner p-n device structures. Devices with sulphurised FeSx i-layers performed least efficiently which is suspected to be due to a less defined FeSx/CdS junction caused by severe conditions during the S annealing process