Development of stitching reinforcement for transport wing panels

The NASA Advanced Composites Technology (ACT) program has the objective of providing the technology required to obtain the full benefit of weight savings and performance improvements offered by composite primary aircraft structures. Achieving the objective is dependent upon developing composite materials and structures which are damage tolerant and economical to manufacture. Researchers are investigating stitching reinforcement combined with resin transfer molding to produce materials meeting the ACT program objective. Research is aimed at materials, processes, and structural concepts for application in both transport wings and fuselages, but the emphasis to date has been on wing panels. Empirical guidelines are being established for stitching reinforcement in structures designed for heavy loads. Results are presented from evaluation tests investigating stitching types, threads, and density (penetrations per square inch). Tension strength, compression strength, and compression after impact data are reported

Using pressure pulse seismology to examine basal criticality and the influence of sticky spots on glacial flow

Here we report results of water pressure pulse studies conducted at Storglaciären (Sweden) and West Washmawapta Glacier (British Columbia, Canada). Comparison of pressure pulse records with meteorological conditions at Storglaciären indicates that several periods of increased basal slip activity observed during a 10 day interval of summer 2008 were due to precipitation loading of the glacier surface, rather than to infiltration of surface water to the glacier bed; this indicates that the glacier bed was close to the failure strength for much of this interval. Pressure pulse magnitudes for the two glaciers were well-fit by power law distributions similar to those earlier observed at Trapridge Glacier (and similar in form to the Gutenberg-Richter relationship commonly used in seismology), suggesting that the mechanical processes that give rise to these distributions are robust features of soft-bedded glaciers. In contrast, interevent time distributions for both glaciers diverge from those observed at Trapridge Glacier for short recurrence intervals, suggesting that the factors that govern the rate at which these processes occur differ between glaciers. An examination of pressure pulse characteristics at West Washmawapta Glacier indicates that the establishment of a basal drainage system in summer 2008 resulted in increased stability and reduced sensitivity to meltwater input, suggesting that common assumptions about the relationship between meltwater production and ice flow are oversimplified. These results demonstrate that water pressure pulse observations can provide valuable insight into the dynamics of soft-bedded glaciers

Demonstration of membrane distillation on textile waste water: assessment of long term performance, membrane cleaning and waste heat integration

© 2017 The Royal Society of Chemistry. This work reports outcomes of a pilot trial and practical assessment of direct contact membrane distillation (DCMD) towards achieving zero liquid discharge at a textile manufacturing plant. Treatment of textile wastewater is difficult due primarily to the complexity of textile processing and the wastewater produced. Combined effluent from the site, either untreated or treated with the site\u27s existing flocculation and biological processes, were considered as the feeds to the MD testing. Initial bench scale studies found rapid membrane wetting appeared to be avoided by the novel use of foam fractionation on the untreated effluent, or by using the conventionally treated effluent. The trial was conducted on treated effluent using fractionation on a side stream within the MD process, and no wetting was observed over the entire 3 month trial duration. The flux of the 6.4 m2 membrane module started at 5 L m-2 h-1 and declined to 2 L m-2 h-1 after more than 65 days. Caustic cleaning effectively restored flux to 4 L m-2 h-1. A 41-fold increase in feed concentration was verified by sulphate measurements, increasing from 567 mg L-1 to 23 000 mg L-1. After concentrating in the hot cycle, all ammonia entering the DCMD plant from the feedwater was found to evolve into the permeate, but non-volatile sulphate rejection was >99.9%. Water recovery at the end of the trial was 91.6%. A plant integration assessment found that zero liquid discharge would be feasible if saline waste streams were isolated and reverse osmosis processes were coupled with MD harnessing waste heat. MD application to current and future treatment scenarios with waste heat integration to textile processing appears viable

State-by-State Report on Permanent Public Access to Electronic Government Information

The purpose of this study was to research what, if anything, state governments are doing to meet the enormous challenges of ensuring permanent public access to state electronic government information. A comprehensive survey was created and distributed to AALL authors in each of the fifty states, the District of Columbia and Puerto Rico. State authors completed the survey by December 2002 and, in addition, submitted a short executive summary based on their survey results. The survey reveals that only one state—Colorado—has enacted legislation that explicitly addresses permanent public access (effective August 15, 2003). No state, including Colorado, comprehensively addresses the challenges of permanent public access to and preservation of electronic government information. State records boards, state archives and state libraries are often aware of permanent public access issues and have often taken steps to preserve electronic information. They have sometimes taken steps to provide continuous public access or have developed guidelines for state agencies to provide such access. These efforts of state records boards, state archives and state libraries are often ineffective, however, because they lack a solid statutory foundation. Without comprehensive statutes supporting a system to coordinate and centralize permanent public access, state agencies thwart the positive efforts of state records boards, state archives and state libraries. The agencies fail to appreciate the need to ensure the full lifecycle of electronic government information, particularly Web-based publications and records. And any guidelines for permanent public access that target them do not solve the problem of agencies’ lack the expertise, personnel and funding. We envisioned that this project would be the first step in the advocacy process necessary to enact state laws that will prevent the loss of important state government information in electronic format. Toward this end, we sought to create a document that could be provided to legislators and other policymakers to educate them about the responsibility of state governments to ensure permanent public access to electronic information. An additional objective was to strengthen the GRC and WAO’s ties to AALL members at the local level, thereby forming a base of activists who could advocate for improved laws mandating permanent public access to state government information. Because AALL and other library organizations lack the manpower to tackle the problem of disappearing electronic government information in all states simultaneously, the Grant Team has identified key states to target for legislative activity

An integrated functional genomic study of acute phenobarbital exposure in the rat.

BACKGROUND: Non-genotoxic carcinogens are notoriously difficult to identify as they do not damage DNA directly and have diverse modes of action, necessitating long term in vivo studies. The early effects of the classic rodent non-genotoxic hepatocarcinogen phenobarbital have been investigated in the Fisher rat using a combination of metabolomics and transcriptomics, to investige early stage mechanistic changes that are predictive of longer term pathology. RESULTS: Liver and blood plasma were profiled across 14 days, and multivariate statistics used to identify perturbed pathways. Both metabolomics and transcriptomics detected changes in the liver which were dose dependent, even after one day of exposure. Integration of the two datasets associated perturbations with specific pathways. Hepatic glycogen was decreased due to a decrease in synthesis, and plasma triglycerides were decreased due to an increase in fatty acid uptake by the liver. Hepatic succinate was increased and this was associated with increased heme biosynthesis. Glutathione synthesis was also increased, presumably in response to oxidative stress. Liquid Chromatography Mass Spectrometry demonstrated a remodeling of lipid species, possibly resulting from proliferation of the smooth endoplasmic reticulum. CONCLUSIONS: The data fusion of metabolomic and transcriptomic changes proved to be a highly sensitive approach for monitoring early stage changes in altered hepatic metabolism, oxidative stress and cytochrome P450 induction simultaneously. This approach is particularly useful in interpreting changes in metabolites such as succinate which are hubs of metabolism.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Reversible suppression of an essential gene in adult mice using transgenic RNA interference

RNAi has revolutionized loss-of-function genetics by enabling sequence-specific suppression of virtually any gene. Furthermore, tetracycline response elements (TRE) can drive expression of short hairpin RNAs (shRNAs) for inducible and reversible target gene suppression. Here, we demonstrate the feasibility of transgenic inducible RNAi for suppression of essential genes. We set out to directly target cell proliferation by screening an RNAi library against DNA replication factors and identified multiple shRNAs against Replication Protein A, subunit 3 (RPA3). We generated transgenic mice with TRE-driven Rpa3 shRNAs whose expression enforced a reversible cell cycle arrest. In adult mice, the block in cell proliferation caused rapid atrophy of the intestinal epithelium which led to weight loss and lethality within 8-11 d of shRNA induction. Upon shRNA withdrawal, villus atrophy and weight loss were fully reversible. Thus, shRpa3 transgenic mice provide an interesting tool to study tissue maintenance and regeneration. Overall, we have established a robust system that serves the purpose of temperature-sensitive alleles in other model organisms, enabling inducible and reversible suppression of essential genes in a mammalian system

Comparison of Glucose Monitoring Methods during Steady-State Exercise in Women

Data from Continuous Glucose Monitoring (CGM) systems may help improve overall daily glycemia; however, the accuracy of CGM during exercise remains questionable. The objective of this single group experimental study was to compare CGM-estimated values to venous plasma glucose (VPG) and capillary plasma glucose (CPG) during steady-state exercise. Twelve recreationally active females without diabetes (aged 21.8 ± 2.4 years), from Central Washington University completed the study. CGM is used by individuals with diabetes, however the purpose of this study was to first validate the use of this device during exercise for anyone. Data were collected between November 2009 and April 2010. Participants performed two identical 45-min steady-state cycling trials (~60% Pmax) on non-consecutive days. Glucose concentrations (CGM-estimated, VPG, and CPG values) were measured every 5 min. Two carbohydrate gel supplements along with 360 mL of water were consumed 15 min into exercise. A product-moment correlation was used to assess the relationship and a Bland-Altman analysis determined error between the three glucose measurement methods. It was found that the CGM system overestimated mean VPG (mean absolute difference 17.4 mg/dL (0.97 mmol/L)) and mean CPG (mean absolute difference 15.5 mg/dL (0.86 mmol/L)). Bland-Altman analysis displayed wide limits of agreement (95% confidence interval) of 44.3 mg/dL (2.46 mmol/L) (VPG compared with CGM) and 41.2 mg/dL (2.29 mmol/L) (CPG compared with CGM). Results from the current study support that data from CGM did not meet accuracy standards from the 15197 International Organization for Standardization (ISO)

Strong laws of large numbers for sub-linear expectations

We investigate three kinds of strong laws of large numbers for capacities with a new notion of independently and identically distributed (IID) random variables for sub-linear expectations initiated by Peng. It turns out that these theorems are natural and fairly neat extensions of the classical Kolmogorov's strong law of large numbers to the case where probability measures are no longer additive. An important feature of these strong laws of large numbers is to provide a frequentist perspective on capacities.Comment: 10 page

A unified approach for the solution of the Fokker-Planck equation

This paper explores the use of a discrete singular convolution algorithm as a unified approach for numerical integration of the Fokker-Planck equation. The unified features of the discrete singular convolution algorithm are discussed. It is demonstrated that different implementations of the present algorithm, such as global, local, Galerkin, collocation, and finite difference, can be deduced from a single starting point. Three benchmark stochastic systems, the repulsive Wong process, the Black-Scholes equation and a genuine nonlinear model, are employed to illustrate the robustness and to test accuracy of the present approach for the solution of the Fokker-Planck equation via a time-dependent method. An additional example, the incompressible Euler equation, is used to further validate the present approach for more difficult problems. Numerical results indicate that the present unified approach is robust and accurate for solving the Fokker-Planck equation.Comment: 19 page