Investigation of smooth specimen scc test procedures; variations in environment, specimen size, stressing frame, and stress state

The variables studied in the stress-corrosion cracking performance of high strength aluminum alloys were: (1) corrosiveness of the environment, (2) specimen size and stiffness of the stressing system, (3) interpretation of transgranular cracking, and (4) interaction of the state of stress and specimen orientation in a product with an anisotropic grain structure. It was shown that the probability of failure and time to fracture for a specimen loaded in direct tension are influenced by corrosion pattern, the stressing assembly stiffness, and the notch tensile strength of the alloy. Results demonstrate that the combination of a normal tension stress and a shear stress acting on the plane of maximum susceptibility in a product with a highly directional grain cause the greatest tendency for stress-corrosion cracking

FRANKLIN COUNTY, IOWA'S PROGRAM IN PUBLIC AFFAIRS

Public Economics,

Neglect, Physical and Sexual Abuse: A Look at Posttraumatic Stress Disorder in Children and Adolescents

This article focuses on Posttraumatic Stress Disorder that is largely overlooked in the counseling field and literature, specifically in children and adolescents. Etiology, treatment options, and the course in which the disorder manifests itself holds great importance in understanding the grave effects these traumatic events have on youth. This article is the beginning attempt to begin to understand how children exhibits symptoms of PTSD in order to work collaboratively with those involved in the child’s life before it develops into a chronic maladaptive state

Within-canopy experimental leaf warming induces photosynthetic decline instead of acclimation in two northern hardwood species

Northern hardwood forests are experiencing higher temperatures and more extreme heat waves, potentially altering plant physiological processes. We implemented in-situ leaf-level warming along a vertical gradient within a mature forest canopy to investigate photosynthetic acclimation potential of two northern hardwood species, Acer saccharum and Tilia americana. After 7 days of +3°C warming, photosynthetic acclimation was assessed by measuring differences between heated and control photosynthetic rates (Aopt) at leaf optimum temperatures (Topt). We also measured the effects of warming and height on maximum rates of Rubisco carboxylation, stomatal conductance, transpiration, and leaf traits: leaf area, leaf mass per area, leaf nitrogen, and leaf water content. We found no evidence of photosynthetic acclimation for either species, but rather Aopt declined with warming overall. We found slight shifts in LMA and Narea, leaf traits associated with photosynthetic capacity, after 1 week of experimental warming. T. americana LMA and Narea was lower in the upper canopy heated leaves than in the control leaves, contributing a shift in Narea height distribution in the heated leaves. T. americana showed evidence of greater resiliency to warming, with greater thermoregulation, physiological plasticity, and evapotranspiration. As expected, Aopt of A. saccharum increased with height, but Aopt of T. americana was highest in the sub canopy, possibly due to constraints on leaf water balance and photosynthetic capacity in the upper canopy. Thus, models relying on canopy height or light environment may incorrectly estimate vertical variation of photosynthetic capacity. If these species are not able to acclimate to warmer temperatures, we could see alteration of plant carbon balance of these two key northern hardwood species

Equivalence-based Security for Querying Encrypted Databases: Theory and Application to Privacy Policy Audits

Motivated by the problem of simultaneously preserving confidentiality and usability of data outsourced to third-party clouds, we present two different database encryption schemes that largely hide data but reveal enough information to support a wide-range of relational queries. We provide a security definition for database encryption that captures confidentiality based on a notion of equivalence of databases from the adversary's perspective. As a specific application, we adapt an existing algorithm for finding violations of privacy policies to run on logs encrypted under our schemes and observe low to moderate overheads.Comment: CCS 2015 paper technical report, in progres

Effect of polymer coatings on fatigue strength of aluminum alloy 2024 box beams

Previous investigators have shown that polymer coatings raise the fatigue strength of metals tested in air to about the same level as that of uncoated specimens tested in vacuum. The results are given of tests to determine if a polymer coating would improve the fatigue strength of built-up aluminum alloy members simulating aircraft construction. Aluminum alloy 2024-T4 riveted box beams were subjected to constant amplitude fatigue tests in air as well as in salt water fog. The coating did not improve the fatigue strength of beams tested in either environment. This is believed to result from the fact that most failures originated at rivet holes, which were isolated from both the coating and the environment

Using Single Molecule mRNA Fluorescent \u3ci\u3ein Situ\u3c/i\u3e Hybridization (RNA-FISH) to Quantify mRNAs in Individual Murine Oocytes and Embryos

Changes in abundance of mRNAs during oocyte growth and maturation and during pre-implantation embryo development have been documented using quantitative real-time RT-PCR (qPCR), microarray analyses, and whole genome sequencing. However, these techniques require amplification of mRNAs, normalization using housekeeping genes, can be biased for abundant transcripts, and/or require large numbers of oocytes and embryos which can be difficult to acquire from mammalian species. We optimized a single molecule RNA fluorescence in situ hybridization (RNA-FISH) protocol, which amplifies fluorescence signal to detect candidate transcripts, for use with individual oocytes and embryos. Quantification using the software Localize showed patterns of Gdf9 and Pou5f1 mRNA expression in oocytes and embryos that were consistent with previously published data. Interestingly, low levels of Nanog mRNA were also accurately and reproducibly measured in oocytes and one- and two-cell embryos suggesting that RNA-FISH could be used to detect and quantify low abundance transcripts. Unlike other techniques, RNA-FISH is also able to detect changes in the localization patterns of mRNAs which may be used to monitor post-transcriptional regulation of a transcript. Thus, RNA-FISH represents an important technique to investigate potential mechanisms associated with the synthesis and stability of candidate mRNAs in mammalian oocytes and embryos