Home Water Testing

Routine testing for a few of the most common contaminants is highly recommended. Even if you currently have a safe, pure water supply, regular testing can be valuable because it establishes a record of water quality. This record can be helpful in solving any future problems and in obtaining compensation if someone damages your water supply. Testing needs to be performed by certified testing laboratory using USEPA methods of collection, storage and testing. Unbiased testing needs to be established and has more validity in court proceedings to establish responsibility

Session B2: An Overview of the Ice Harbor Turbine Replacement Project

Abstract: In March of 2010 the US Army Corps of Engineers’ (USACE) awarded a contract to Voith Hydro to design and supply new turbine runners for installation at the Ice Harbor Lock and Dam located on the Lower Snake River within the State of Washington, USA. The contract included design and supply of both a fixed and an adjustable blade turbine runner for replacement of two failing units within the six unit powerhouse. The new turbine runners were to be designed for “safer” fish passage as a primary goal, and increased efficiency as a secondary goal. The hydraulic design of both runner types was a collaborative effort by the USACE’s Walla Walla District (NWW), Engineer Research and Development Center (ERDC), Hydroelectric Design Center (HDC), National Marine Fisheries Service (NMFS) and Voith Hydro. The design criteria and the design evaluation process were developed by the USACE over years of both field and laboratory research through the Turbine Survival Program. The two runner types were designed through an iterative process of Computational Fluid Dynamic Model analysis, performance model testing for power, efficiency and cavitation, and physical hydraulic model testing for evaluation of the turbine passage environment. This presentation provides a broad overview of the research, design criteria and guidelines, the design and evaluation process, and future biological field testing efforts supporting the Ice Harbor turbine runner replacement project

Correlations of behavioral deficits with brain pathology assessed through longitudinal MRI and histopathology in the HdhQ150/Q150 mouse model of huntington's disease

A variety of mouse models have been developed that express mutant huntingtin (mHTT) leading to aggregates and inclusions that model the molecular pathology observed in Huntington's disease. Here we show that although homozygous HdhQ150 knock-in mice developed motor impairments (rotarod, locomotor activity, grip strength) by 36 weeks of age, cognitive dysfunction (swimming T maze, fear conditioning, odor discrimination, social interaction) was not evident by 94 weeks. Concomitant to behavioral assessments, T2-weighted MRI volume measurements indicated a slower striatal growth with a significant difference between wild type (WT) and HdhQ150 mice being present even at 15 weeks. Indeed, MRI indicated significant volumetric changes prior to the emergence of the "clinical horizon" of motor impairments at 36 weeks of age. A striatal decrease of 27% was observed over 94 weeks with cortex (12%) and hippocampus (21%) also indicating significant atrophy. A hypothesis-free analysis using tensor-based morphometry highlighted further regions undergoing atrophy by contrasting brain growth and regional neurodegeneration. Histology revealed the widespread presence of mHTT aggregates and cellular inclusions. However, there was little evidence of correlations between these outcome measures, potentially indicating that other factors are important in the causal cascade linking the molecular pathology to the emergence of behavioral impairments. In conclusion, the HdhQ150 mouse model replicates many aspects of the human condition, including an extended pre-manifest period prior to the emergence of motor impairments

Sonoluminescence and sonochemiluminescence from a microreactor

Micromachined pits on a substrate can be used to nucleate and stabilize microbubbles in a liquid exposed to an ultrasonic field. Under suitable conditions, the collapse of these bubbles can result in light emission (sonoluminescence, SL). Hydroxyl radicals (OH*) generated during bubble collapse can react with luminol to produce light (sonochemiluminescence, SCL). SL and SCL intensities were recorded for several regimes related to the pressure amplitude (low and high acoustic power levels) at a given ultrasonic frequency (200 kHz) for pure water, and aqueous luminol and propanol solutions. Various arrangements of pits were studied, with the number of pits ranging from no pits (comparable to a classic ultrasound reactor), to three-pits. Where there was more than one pit present, in the high pressure regime the ejected microbubbles combined into linear (two-pits) or triangular (three-pits) bubble clouds (streamers). In all situations where a pit was present on the substrate, the SL was intensified and increased with the number of pits at both low and high power levels. For imaging SL emitting regions, Argon (Ar) saturated water was used under similar conditions. SL emission from aqueous propanol solution (50 mM) provided evidence of transient bubble cavitation. Solutions containing 0.1 mM luminol were also used to demonstrate the radical production by attaining the SCL emission regions.Comment: http://www.sciencedirect.com/science/article/pii/S1350417712000855; ISSN 1350-417

Expanding CubeSat Capabilities with a Low Cost Transceiver

CubeSats have developed rapidly over the past decade with the advent of a containerized deployer system and ever increasing launch opportunities. These satellites have moved from an educational tool to teach students about engineering challenges associated with satellite design, to systems that are conducting cutting edge earth, space and solar science. Early variants of the CubeSat had limited functionality and lacked sophisticated attitude control, deployable solar arrays and propulsion. This is no longer the case and as CubeSats mature, such systems are becoming commercially available. The result is a small satellite with sufficient power and pointing capabilities to support a high rate communication system. Communications systems have matured along with other CubeSat subsystems. Originally developed from amateur radio systems, CubeSats have generally operated in the VHF and UHF bands at data rates below 10 kbps (kilobits per second). More recently higher rate UHF systems have been developed, however these systems require a large collecting area on the ground to close the communications link at 3 Mbps (megabits per second). Efforts to develop systems that operate with similar throughput at S-Band (2-4 GHz (gigaherz)) and C-Band (4-8 GHz (gigaherz)) have also recently evolved. In this paper we outline an effort to develop a high rate CubeSat communication system that is compatible with the NASA Near Earth Network and can be accommodated by a CubeSat. The system will include a 200 kbps (kilobits per second) S-Band receiver and a 12.5 Mbps (megabits per second).X-Band transmitter. This paper will focus on our design approach and initial results associated with the 12.5 Mbps (megabits per second) X-band transmitter

SpaceCube v3.0 NASA Next-Generation High-Performance Processor for Science Applications

Electronics for space systems must address several considerable challenges including achieving operational resiliency within the hazardous space environment and also meeting application performance needs while simultaneously managing size, weight, and power requirements. To drive the future revolution in space processing, onboard systems need to be more flexible, affordable, and robust. In order to provide a robust solution to a variety of missions and instruments, the Science Data Processing Branch at NASA Goddard Space Flight Center (GSFC)has pioneered a hybrid-processing approach that combines radiation-hardened and commercial components while emphasizing a novel architecture harmonizing the best capabilities of CPUs, DSPs, and FPGAs. This hybrid approach is realized through the SpaceCube family of processor cards that have extensive flight heritage on a variety of mission classes. The latest addition to the SpaceCube family, SpaceCube v3.0, will function as the next evolutionary step for upcoming missions, allow for prototyping of designs and software, and provide a flexible, mature architecture that is also ready to adopt the radiation-hardened High-Performance Spaceflight Computing (HPSC) chiplet when it is released. The research showcased in this paper describes the design methodology, analysis, and capabilities of the SpaceCube v3.0 SpaceVPX Lite (VITA 78.1) 3U-220mm form-factor processor card

Electron tomographic analysis of synaptic ultrastructure

Synaptic function depends on interactions among sets of proteins that assemble into complex supramolecular machines. Molecular biology, electrophysiology, and live-cell imaging studies have provided tantalizing glimpses into the inner workings of the synapse, but fundamental questions remain regarding the functional organization of these “nano-machines.” Electron tomography reveals the internal structure of synapses in three dimensions with exceptional spatial resolution. Here we report results from an electron tomographic study of axospinous synapses in neocortex and hippocampus of the adult rat, based on aldehyde-fixed material stabilized with tannic acid in lieu of postfixation with osmium tetroxide. Our results provide a new window into the structural basis of excitatory synaptic processing in the mammalian brain

Grain coarsening behaviour of solution annealed Alloy 625 between 600–800°C

As with all alloys, the grain structure of the nickel-base superalloy 625 has a significant impact on its mechanical properties. Predictability of the grain structure evolution in this material is particularly pertinent because it is prone to inter-metallic precipitate formation both during manufacture and long term or high temperature service. To this end, analysis has been performed on the grain structure of Alloy 625 aged isothermally at temperatures between 600 and 800 °C for times up to 3000 h. Fits made according to the classical Arrhenius equation describing normal grain growth yield an average value for the activation energy of a somewhat inhomogeneous grain structure above 700 °C of 108.3±6.6 kJ mol−1 and 46.6±12.2 kJ mol−1 below 650 °C. Linear extrapolation between 650 and 700 °C produces a significantly higher value of 527.7±23.1 kJ mol−1. This result is ultimately a consequence of a high driving force, solute-impeded grain boundary migration process operating within the alloy. Comparison of the high and low temperature values with the activation energy for volume self-diffusion and grain boundary diffusion identifies the latter as the principle governing mechanism for grain growth in both instances. A decrease in the value of the time exponent (n) at higher temperatures despite a reduction in solute drag is attributable to the Zener pinning imposed by grain boundary M6C and M23C6 particles identified from Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectroscopy (EDXS) analysis. Vickers hardness results show the dominance of intermetallic intragranular precipitates in the governance of the mechanical properties of the material with grain coarsening being accompanied by a significant increase in hardness. Furthermore, the lack of any correlation with grain growth behaviour indicates these phases have no significant effect on the grain evolution of the material

Correlations of behavioral deficits with brain pathology assessed through longitudinal MRI and histopathology in the R6/1 mouse model of huntington's disease

Huntington's disease (HD) is caused by the expansion of a CAG repeat in the huntingtin (HTT) gene. The R6 mouse models of HD express a mutant version of exon 1 HTT and typically develop motor and cognitive impairments, a widespread huntingtin (HTT) aggregate pathology and brain atrophy. Unlike the more commonly used R6/2 mouse line, R6/1 mice have fewer CAG repeats and, subsequently, a less rapid pathological decline. Compared to the R6/2 line, fewer descriptions of the progressive pathologies exhibited by R6/1 mice exist. The association between the molecular and cellular neuropathology with brain atrophy, and with the development of behavioral phenotypes remains poorly understood in many models of HD. In attempt to link these factors in the R6/1 mouse line, we have performed detailed assessments of behavior and of regional brain abnormalities determined through longitudinal, in vivo magnetic resonance imaging (MRI), as well as an end-stage, ex vivo MRI study and histological assessment. We found progressive decline in both motor and non-motor related behavioral tasks in R6/1 mice, first evident at 11 weeks of age. Regional brain volumes were generally unaffected at 9 weeks, but by 17 weeks there was significant grey matter atrophy. This age-related brain volume loss was validated using a more precise, semi-automated Tensor Based morphometry assessment. As well as these clear progressive phenotypes, mutant HTT (mHTT) protein, the hallmark of HD molecular pathology, was widely distributed throughout the R6/1 brain and was accompanied by neuronal loss. Despite these seemingly concomitant, robust pathological phenotypes, there appeared to be little correlation between the three main outcome measures: behavioral performance, MRI-detected brain atrophy and histopathology. In conclusion, R6/1 mice exhibit many features of HD, but the underlying mechanisms driving these clear behavioral disturbances and the brain volume loss, still remain unclear. © 2013 Rattray et al

Stuttering, alcohol consumption and smoking

Purpose: Limited research has been published regarding the association between stuttering and substance use. An earlier study provided no evidence for such an association, but the authors called for further research to be conducted using a community sample. The present study used data from a community sample to investigate whether an association between stuttering and alcohol consumption or regular smoking exists in late adolescence and adulthood. Methods: Regression analyses were carried out on data from a birth cohort study, the National Child Development Study (NCDS), whose initial cohort included 18,558 participants who have since been followed up until age 55. In the analyses, the main predictor variable was parent-reported stuttering at age 16. Parental socio-economic group, cohort member’s sex and childhood behavioural problems were also included. The outcome variables related to alcohol consumption and smoking habits at ages 16, 23, 33, 41, 46, 50 and 55. Results: No significant association was found between stuttering and alcohol consumption or stuttering and smoking at any of the ages. It was speculated that the absence of significant associations might be due to avoidance of social situations on the part of many of the participants who stutter, or adoption of alternative coping strategies. Conclusion: Because of the association between anxiety and substance use, individuals who stutter and are anxious might be found to drink or smoke excessively, but as a group, people who stutter are not more likely than those who do not to have high levels of consumption of alcohol or nicotine