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Lewis County Resource Guide - Idaho
Get PDFCounty level and region-specific resource guides focused on mental health and substance use
RESIDUAL STRESS INVESTIGATIONS IN PROCESSED LAYERED METALLIC MATERIALS THROUGH SURFACE SENSITIVE CHARACTERIZATION METHODS
Get PDFResidual stresses are naturally induced in various material processes and can originate mechanically or thermally. They are internal and remain in the material even after processing or loading is removed. Their location, magnitude, and type (i.e., tensile or compressive) can either be beneficial or detrimental to the mechanical behavior of the material. Layered materials and dissimilar metals create complex microstructures and interfaces, complicating residual stress profiles and affecting mechanical properties. There are challenges, however, with measuring residual stresses since they are internal, require a stress-free reference, are inferred from strain, and their values may differ depending on the measurement technique used. This research completed three studies in which layered metallic specimens were produced through three different processing methods and residual stresses were measured with three different characterization techniques.The first study involves commercially pure titanium additively manufactured samples through the directed energy deposition process. Two scanning speeds (500, 1000 mm/min) and three scanning patterns (one cross-hatched and two unidirectional) were explored while laser power remained constant. The top, middle, and bottom of the specimens were characterized with electron backscatter diffraction (EBSD) to investigate microstructure, phase, and kernel average misorientation (KAM). A face centered cubic (FCC) phase was identified, as well as a Kurjumow-Sachs orientation relationship between this FCC phase and the parent beta phase, suggesting the material consisted of a complete beta structure at high temperatures and then transitioned to a combination of FCC and HCP during cooling. Energy dispersive spectroscopy was also used to investigate composition, where the FCC phase was presumed not to be a hydride or oxide. Small amounts of nitrogen were identified, though no clear relationship was found between nitrogen and the FCC phase. A larger amount of the FCC phase was found in unidirectional scanning patterns for the slower scanning speed specimens, while the cross-hatched pattern for both scanning speeds showed a lower amount of FCC, indicating that the scanning pattern could impact the formation of the FCC phase. Additionally, this FCC phase could be influenced or activated by the heating of the additive process, suggesting scanning speed could be a cause. The highest KAM averages belong to the FCC phase of the faster scanning speed specimens due to faster cooling in the additive process, causing more deformation in the material. Residual stresses were also investigated through a cross-correlation EBSD (CC-EBSD) software called ATEX. The general trend suggests that FCC regions contain higher stress while HCP regions contain lower stress, corresponding to KAM map trends. The FCC phase contains more local lattice curvature and higher GND density, relating to higher local plastic strain.The second study consists of metal sheets of alternating layers of aluminum alloys 1050 and 5052, manufactured through a severe plastic deformation method known as the friction assisted lateral extrusion process (FALEP). An additional shear force drives this process to produce homogenous ultrafine-grained structures in a single step. There were variations in the thicknesses of layers after the shearing process, which may be due to the differences in hardness between the two alloys and a reflection of how FALEP interacts with multi-material specimens. Residual stresses were measured across all layers for both longitudinal (σ11) and transverse (σ22) directions with X-ray diffraction using the cos(α) method. Flow stress values for stress calculations were determined through high-pressure compressive shearing. Microstructure was investigated with EBSD, and grain size distributions were determined. The average grain size for AA1050 was approximately 0.75 μm, while AA5052 showed a bimodal distribution for grain sizes slightly below and above 1 μm, with the average being approximately 1.14 μm. Pole figures were also created, showing a shear texture. Residual stress profiles displayed an oscillating pattern for both stress components. Layered specimens showed slight compressive stresses near interfaces for the σ11 component. The magnitude of longitudinal RS values (±40 MPa) are larger than that of the transverse component (±20 MPa), with an uncertainty of ±9 MPa.The third study involves titanium alloy Ti6Al4V diffusion bonded to vanadium. EBSD and EDS were performed to investigate microstructure and determine composition.Microstructures in the bulk of both materials show vanadium grains are approximately 3X larger than Ti6Al4V grains, and pole figures show both materials have a rolling texture. There were four microstructural regions of interest across the interface: primary α-Ti, α-Ti transformation, β-Ti, and V. It was found that this β-Ti phase had formed along the interface due to V acting as a beta stabilizer. Parent grain reconstruction shows that the α-Ti transformation structure originates from β-Ti grains rather than primary α-Ti grains. EDS results show a change in composition across the β-Ti region, making it difficult to obtain an accurate reference specimen for stress calculations from nanoindentation. There are clear differences in hardness for primary α-Ti, β-Ti, and V regions, and this hardness decreases moving across the interface from primary α-Ti to V. Residual stresses were measured using nanoindentation, CC-EBSD with ATEX software, and XRD using the sin2Ψ method. The general residual stress trend between indentation and CC-EBSD results consists of compressive stress in the primary α-Ti region and tensile stress in β-Ti and V regions, with β-Ti having a slightly larger magnitude of stress than V. Residual stress occurs from the mismatch in microstructures (BCC to HCP), interstitials from diffusion bonding, pile up of dislocations at the interface, and differences in properties between materials (i.e. coefficients of thermal expansion). Further analyses are necessary to understand trends associated with XRD measurements
Biodiversity of Bees (Hymenoptera: Anthophila) and Macromoths (Lepidoptera) on Fairchild Air Force Base
Get PDFInsects are critical to the functioning of terrestrial ecosystems around the globe and their importance cannot be overstated. Many aspects of the modern day are impacting the overall survival of insect fauna; climate change and habitat loss being chiefly among those. Of all the insects, pollinators are a particularly important group because the act of pollination is a keystone ecosystem service that contributes heavily to biological diversity. Bees and moths are two of the largest pollinator taxa among insects. Because of their contribution as pollinators, these two taxa are also important indicators of ecosystem health. Many bees are specialists on the pollen of particular plants and the presence of different species can help us understand the diversity of angiosperms in a given area and availability of floral resources for other pollinators. Moths are often host-plant specific as larvae and can similarly inform plant biodiversity in a given area. These animals were used as focal groups during our survey of Fairchild Air Force Base (FAFB), just west of Spokane, Washington. Military Training Areas (MTAs), like the one surveyed at FAFB, are known to harbor a disproportionate number of endangered and imperiled species compared to land owned by other U.S. government agencies and may also play a role in conserving biological diversity in general. Our findings in this study support this idea. We spent two field seasons performing regular surveys of FAFB that utilized both active and passive collecting methods. We found an unexpectedly high biodiversity of bees on our study site, including several undescribed species and many new records for Spokane county and one for the state. Our assessments of moths, too, showed a high biodiversity and reflected what is typical of an eastern Washington dry grassland and sagebrush shrub-steppe habitat. Surveys are critical to documenting biological diversity and change through time and ours will create a baseline for future assessments of FAFB's insect fauna. The proportionally high biological diversity of critical groups like bees and moths found during this study reinforces the importance of the role that military land plays in conservation, and how critical it is to perform surveys like this
Evaluation of chlorine and peroxyacetic acid for Listeria monocytogenes control in apple dump tank practice
Get PDFRecent outbreaks and recalls of fresh apples due to Listeria monocytogenes contamination highlight the need for effective foodborne pathogen control on fresh apples. During post-harvest packing, apples are first washed in sanitizer-treated dump tank water, which accumulates organic matter over time, potentially reducing sanitizer efficacy. However, the effectiveness of this process remains scientifically underexplored. This dissertation comprehensively evaluated the effectiveness of two commonly used sanitizers, chlorine and peroxyacetic acid (PAA), in controlling L. monocytogenes during apple dump tank practice at both bench and pilot scales and further developed mathematical models to predict the anti-Listeria efficacy of chlorine under various conditions. Laboratory-scale experiments using simulated dump tank water (SDTW) in a hand-agitation system demonstrated that both chlorine and PAA exhibited concentration-dependent efficacy against L. monocytogenes on inoculated apples. The anti-Listeria efficacy of chlorine at initial 25 - 100 ppm free chlorine (FC) was significantly impacted by organic load, especially at 25 ppm FC in SDTW with 1000 ppm chemical oxygen demand (COD). PAA’s efficacy was similarly affected at initial 10 ppm but remained stable at 20 - 80 ppm. To further assess these findings under commercial conditions, a 102-L pilot-scale dump tank system was employed. Chlorine and PAA significantly reduced the Listeria innocua cross-contamination between apples and water but did not eliminate it. A 0.5 - 10 min wash using 25 - 100 ppm FC resulted in reductions of 0.4 - 1.1 log CFU/apple on inoculated apples and 3.5 - 5.4 log CFU/ml in inoculated SDTW, leading to transfers of 0.4 - 3.5 log CFU/apple to uninoculated apples. PAA at 20 - 80 ppm achieved reductions of 0.5 - 1.5 log CFU/apple on inoculated apples and 0.7 - 4.3 log CFU/ml in inoculated SDTW, with transfer levels of 3.5 - 4.2 log CFU/apple to uninoculated apples. Elevating the organic load in SDTW from 1000 to 4000 ppm COD further reduced chlorine’s efficacy against L. innocua and PAA’s effectiveness in water.To quantify and predict chlorine’s efficacy, response surface methodology (RSM) models were developed using the pilot-scale dump tank system. These models incorporated key parameters including FC level, Listeria contamination level, and COD level, to predict the anti-Listeria efficacy of chlorine in apple dump tank processing. The RSM models demonstrated strong predictive accuracy (R2 = 0.91 - 0.98) and were validated using commercial apple dump tank water, showing high agreement between the predicted and observed responses. The findings provided valuable insights into the practical efficacy of sanitizer-treated apple dump tank processing and developed a reliable tool for assessing the anti-Listeria efficacy of chlorine, in compliance with federal regulations and ensuring the microbial safety of fresh apples
NUMERICAL STUDY ON OSCILLATING HYDROFOILS FOR ENERGY EXTRACTION
Get PDFThe global pursuit of clean and renewable energy has driven interest in unconventional technologies capable of operating efficiently in variable aquatic environments. Among these, flapping hydrofoils have emerged as a bioinspired solution for sustainable hydrokinetic energy harvesting. Using flapping hydrofoils is a promising approach to capturing hydrokinetic energy from river and tidal flows. Unlike traditional rotational mechanisms, flapping hydrokinetic devices offer several advantages, including simpler foil geometries, reduced structural demands, improved hydrodynamic performance, suitability for shallow waters, and lower impacts on aquatic ecosystems. While previous numerical studies have mainly focused on hydrofoils with fully prescribed motions, this study investigates the energy harvesting performance of an oscillating hydrofoil using a semi-passive model strategy. The pitching motion is prescribed while the heaving response is driven purely by unsteady hydrodynamic forces. A fully prescribed configuration is also simulated under matching flow and motion conditions to enable direct performance comparison. Simulations are performed using a 2-D unsteady Reynolds-Averaged Navier–Stokes (URANS) framework implemented via overset mesh around a NACA0012 hydrofoil in ANSYS Fluent. The numerical model is set at a Reynolds number of 3.6×105, representative of practical deployment in riverine environments.A series of simulations are first conducted to identify optimal operating parameters for the fully prescribed hydrofoil. A reduced frequency f ∗ = 0.1443, pitching amplitude of 70◦, and sinusoidal motion profiles were found to deliver the highest energy conversion efficiency. These parameters are subsequently applied to the semi-passive configuration, enabling the hydrofoil to respond freely in the vertical direction while maintaining a pitch input.Simulation results reveal that the fully prescribed system achieves a total efficiency of 38.6%, with heaving motion accounting for a heaving efficiency of 57.55% and a total average power output of 139.53 W. In contrast, the semi-passive model generates significant unsteady vertical motion—approximately three times larger in displacement—yet fails to convert this motion into usable power due to a lack of phase alignment between the hydrodynamic forces and the heaving response. This leads to negative net power generation (-446.61 W) and an overall efficiency of -31.87%. The unsteady heaving response exhibits irregularity across cycles, with sharp peaks in velocity and force magnitudes.These results indicate that while passive vertical motion in oscillating hydrofoils can induce large displacements, it does not inherently result in effective energy harvesting unless additional damping or synchronization mechanisms are introduced. The study highlights the need for further investigation into hybrid or semi-active strategies that can extract usable power from passive motion while preserving mechanical simplicity and adaptability to unsteady flow conditions
COPPER-ADDED STAINLESS STEEL AND TITANIUM ALLOYS FOR BACTERIAL RESISTANCE IN BIOMEDICAL DEVICES
Get PDFIn response to the growing demand for advanced materials with inherent infection resistance, this research investigates the material properties of 316L stainless steel and Ti6Al4V (Ti64) alloys with copper addition, produced through laser-directed energy deposition additive manufacturing. This study focuses on three stainless steel compositions (316L, 316L-3Cu, and 316L-5Cu) and four titanium compositions (Ti64, Ti32-10Ta-3Cu, Ti32-10Ta-5Cu, and Ti32-10Ta-7Cu). Compressive strength measurements and Vickers hardness tests were conducted to assess mechanical properties, while microstructural characterization and X-ray diffraction analysis provided insights into the material’s physical properties. Copper showed minimal effect on strength and hardness in 316L but significantly increased mechanical properties of Ti-Ta-Cu alloys, increasing yield strength by 22% and hardness by 13% when compared to Ti64. This research extends beyond mechanical and physical properties by exploring the on-contact antibacterial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa for up to 72 hours. Copper addition resulted in significant bacterial resistance against both strains, with 316L-Cu alloys displaying up to 88% efficacy against S. aureus and 97% against P. aeruginosa. In comparison, Ti-Ta-Cu alloys exhibited up to 98% and 93% at the maximum time points. The findings of this investigation have the potential to benefit biomedical devices, contributing to both the structural and biofunctional properties of materials
FIGHTING AT THE MESO-LEVEL? AN ORGANIZATIONAL APPROACH TO ENVIRONMENTAL INEQUALITY AND JUSTICE
Get PDFFollowing the 1982 Warren County, North Carolina waste siting dispute, research has overwhelmingly demonstrated that environmental harms (e.g., pollution, hazardous facilities, extractive industries) and environmental benefits (e.g., green spaces, stocked grocery stores, green infrastructure) are distributed unequally along racial, class, gender, and geographic lines: a key assertion by environmental justice (EJ) activists and scholars. While scholars have made great strides in identifying individual and state-level barriers and solutions to the remediation of environmental injustice, the meso-level and the entities within it remain undertheorized in the generation, preservation, and interruption of environmental inequality and injustice. This dissertation offers a novel approach to understanding environmental inequality and justice (EIJ) by focusing on the meso-level and integrating insights from environmental sociology, organizational sociology, and the sociology of race and ethnicity. It presents a series of theoretical frameworks for a body of EIJ scholarship that wholly considers the meso-level, one that examines interconnected meso-level dynamics, rather than just individual meso-level actors. Additionally, this dissertation introduces environmental movement organizations (EMOs), specifically environmental nonprofits, as a critical meso-level case to elucidate mechanisms that shape environmental inequalities. I provide empirical assessments of this case, first using longitudinal qualitative content analysis of a leading organization materials. This assessment reveals minimal and inconsistent adoption of EJ principles, influenced by the organization's historical focus on wilderness conservation and an underlying white organizational logic. I follow this qualitative examination with a survey experiment to investigate whether environmental social movement organizations face financial penalties for implementing racially targeted programs. The findings suggest that while organizations may not face financial penalties in overall donation levels, they are likely to experience a change in their supporter base, highlighting the significant influence of color-blind racial ideology on donor behavior. To conclude, I offer directions for future research and organizational practices aimed at disrupting the institutionalization of environmental inequality, emphasizing the potential of the meso-level to be both inequality-generating and inequality-eliminating
FIRST-YEAR UNIVERSITY STUDENTS' SCIENTIFIC LITERACY AND ENGAGEMENT WITH SOCIOSCIENTIFIC ISSUES
Get PDFThis dissertation explores scientific literacy among first-year university students through analysis of their engagement with and perceptions of socioscientific issues. The research was conducted at a regional campus of a public land-grant institution in the American Pacific Northwest, where the impacts of climate change, the aftermath of the COVID-19 pandemic, and rapidly accelerating energy demands have brought socioscientific issues into the public discourse. Undergraduates, who are joining the electorate and preparing to enter the workforce, must develop the competencies to make informed decisions about these issues impacting their personal lives, their communities, and the region. To investigate students’ scientific literacy, their use and trust of sources of scientific information, and their perceptions and behaviors related to socioscientific issues, a survey with both closed and open-ended items was developed, piloted, and administered to a representative sample of 110 first-year students. This yielded a combination of descriptive and statistical data that were analyzed and integrated to reveal comprehensive answers to the research questions. Findings demonstrated significant variations in students’ use and trust in sources of scientific information, with digital media and artificial intelligence applications emerging as popular yet polarizing sources. Statistical analysis revealed variation in scientific literacy across demographic groups and correlations between students’ self-perceived and measured scientific literacy. The results of the research challenge previous findings by demonstrating that greater levels of scientific literacy predict greater concern for socioscientific issues, regardless of political ideology. Implications for undergraduate science education include integrating contemporary and locally relevant socioscientific issues into introductory science courses, which may foster scientific literacy among first-year university students by allowing them to connect concepts learned in the classroom to their own lived experiences
Emotion Suppression, Help-Seeking, and Culture
Get PDFThere is large evidence suggesting a strong link between emotion suppression and poor mental health outcomes. However, how emotion suppression relates to one’s likelihood of seeking professional psychological help requires further exploration. Additionally, there are cultural variations on how emotion suppression is perceived and utilized. The current study sought to explore the role of emotion suppression on help-seeking and examine its cultural variations. Constructs related to emotion suppression were examined in this study, including self-disclosure and help-seeking attitudes and intentions. Self-construal was employed as a measure of cultural orientation and three types of self-construal (i.e., independent, interdependent, relational) were explored in this study. The proposed study had two specific aims: (1) determine whether emotion suppression and self-disclosure predict help-seeking attitudes and intentions, and (2) explore the role of culture, as measured by self-construal, on the above framework. A sample of 419 undergraduate college students were recruited from the Washington State University Psychology Human Subject Pool. Latent path modeling was conducted to test nine hypotheses. The results indicated that: (1) help-seeking attitudes mediated the relationship between emotion suppression or self-disclosure and help-seeking intentions; (2) self-construal predicted emotion suppression and self-disclosure; and (3) relational self-construal slightly moderated the relationship between self-disclosure and help-seeking attitudes. Implications for clinical practice and future research on emotion suppression and help-seeking are discussed
Compact Wideband Circularly Polarized MIMO Antennas for IoT Applications Flexible and Rigid Designs
Get PDFThe rapid increase of Internet of Things (IoT) devices has intensified the demand for compact, flexible, and high-performance antenna systems capable of reliable operation across diverse and dynamic environments. This thesis focuses on the development of circularly polarized (CP) multiple-input multiple-output (MIMO) antennas tailored for IoT applications, emphasizing wide bandwidth, high isolation, and mechanical flexibility. A single-element CP antenna is first designed using a C-shaped coplanar waveguide (CPW)-fed structure on a flexible polyethylene terephthalate (PET) substrate, fabricated via inkjet printing. This antenna achieves a wide 3-dB axial ratio bandwidth (ARBW) of 5.66 GHz (79.94%) from 4.25 GHz to 9.91 GHz, along with a 10-dB impedance bandwidth (IBW) of 7.67 GHz (99.55%) from 3.87 GHz to 11.54 GHz, making it highly suitable for wearable and conformal IoT devices. Building on this, a two-element CP MIMO configuration is developed with a diamond-shaped decoupling structure, achieving over 20 dB isolation and a remarkable ARBW of 6 GHz (4.7–10.7 GHz). The mirrored arrangement of antenna elements enhances polarization diversity and ensures stable performance under bending—critical for integration into flexible and body-worn IoT systems. For fixed IoT installations requiring robust and compact solutions, a four-element CP MIMO antenna is proposed on a Rogers TMM4 substrate. Featuring a plus-shaped decoupling structure (PSDS), the design achieves an ARBW of 3.29 GHz (5.02–8.31 GHz) and over 25 dB isolation, without increasing the antenna footprint. The proposed antenna systems demonstrate significant advancements in bandwidth, isolation, and mechanical adaptability, offering versatile solutions for next-generation IoT communication platforms