Environmental exposure effects on composite materials for commercial aircraft

A study was conducted to determine the effects of long term flight and ground exposure on three commercially available graphite-epoxy material systems: T300/5208, T300/5209, and T300/934. Sets of specimens were exposed on commercial aircraft and ground racks for 1, 2, 3, 5, and 10 years. Inflight specimen sites included both the interior and exterior of aircraft based in Hawaii, Texas, and New Zealand. Ground racks were located at NASA-Dryden and the above mentioned states. Similar specimens were exposed to controlled lab conditions for up to 2 years. After each exposure, specimens were tested for residual strength and a dryout procedure was used to measure moisture content. Both room and high temperature residual strengths were measured and expressed as a pct. of the unexposed strength. Lab exposures included the effects of time alone, moisture, time on moist specimens, weatherometer, and simulated ground-air-ground cycling. Residual strengths of the long term specimens were compared with residual strengths of the lab specimens. Strength retention depended on the exposure condition and the material system. Results showed that composite materials can be successfully used on commercial aircraft if environmental effects are considered

Pyrolysis of Wastewater Biosolids Significantly Reduces Estrogenicity

Most wastewater treatment processes are not specifically designed to remove micropollutants. Many micropollutants are hydrophobic so they remain in the biosolids and are discharged to the environment through land-application of biosolids. Micropollutants encompass a broad range of organic chemicals, including estrogenic compounds (natural and synthetic) that reside in the environment, a.k.a. environmental estrogens. Public concern over land application of biosolids stemming from the occurrence of micropollutants hampers the value of biosolids which are important to wastewater treatment plants as a valuable by-product. This research evaluated pyrolysis, the partial decomposition of organic material in an oxygen-deprived system under high temperatures, as a biosolids treatment process that could remove estrogenic compounds from solids while producing a less hormonally active biochar for soil amendment. The estrogenicity, measured in estradiol equivalents (EEQ) by the yeast estrogen screen (YES) assay, of pyrolyzed biosolids was compared to primary and anaerobically digested biosolids. The estrogenic responses from primary solids and anaerobically digested solids were not statistically significantly different, but pyrolysis of anaerobically digested solids resulted in a significant reduction in EEQ; increasing pyrolysis temperature from 100 °C to 500 °C increased the removal of EEQ with greater than 95% removal occurring at or above 400 °C. This research demonstrates that biosolids treatment with pyrolysis would substantially decrease (removal \u3e 95%) the estrogens associated with this biosolids product. Thus, pyrolysis of biosolids can be used to produce a valuable soil amendment product, biochar, that minimizes discharge of estrogens to the environment

Evaluating Net Groundwater Use from Remotely Sensed Evapotranspiration and Water Delivery Information

A detailed, comprehensive, and accurate identification of groundwater aquifer properties will likely never be fully achieved because of the high degree of variability and costs that testing involves. Furthermore, accurate estimates of boundary conditions are essential for groundwater modeling so that investigations of improved management scenarios can be conducted. The lack of key input values at the ground surface boundary limits the ability to accurately assess aquifer dynamics. Of major importance is actual evapotranspiration (water consumption or the loss of water to the atmosphere through transpiration and evaporation). The Irrigation Training and Research Center (ITRC) modified remotely sensed satellite imagery for spatial computation of actual evapotranspiration at high resolution, and integrated it into groundwater models. This paper focuses on an additional tool to assist in the calibration of groundwater models, which results in the NET contribution to or extraction from groundwater (NTFGW). By comparing surface water deliveries, precipitation, runoff, and evapotranspiration, the NTFGW can be computed spatially throughout a region. This provides a critical set of known information, in addition to historic groundwater elevation data, that can be used in model calibration

DEVELOPMENTAL ORIGINS OF METABOLIC DISEASES

Almost 2 billion adults in the world are overweight, and more than half of them are classified as obese, while nearly one-third of children globally experience poor growth and development. Given the vast amount of knowledge that has been gleaned from decades of research on growth and development, a number of questions remain as to why the world is now in the midst of a global epidemic of obesity accompanied by the “double burden of malnutrition,” where overweight coexists with underweight and micronutrient deficiencies. This challenge to the human condition can be attributed to nutritional and environmental exposures during pregnancy that may program a fetus to have a higher risk of chronic diseases in adulthood. To explore this concept, frequently called the developmental origins of health and disease (DOHaD), this review considers a host of factors and physiological mechanisms that drive a fetus or child toward a higher risk of obesity, fatty liver disease, hypertension, and/or type 2 diabetes (T2D). To that end, this review explores the epidemiology of DOHaD with discussions focused on adaptations to human energetics, placental development, dysmetabolism, and key environmental exposures that act to promote chronic diseases in adulthood. These areas are complementary and additive in understanding how providing the best conditions for optimal growth can create the best possible conditions for lifelong health. Moreover, understanding both physiological as well as epigenetic and molecular mechanisms for DOHaD is vital to most fully address the global issues of obesity and other chronic diseases

The Thiol-Rich Interlayer in the Shell/Core Architecture of Mussel Byssal Threads.

The mussel byssus thread is an extremely tough core-shelled fiber that dissipates substantial amounts of energy during tensile loading. The mechanical performance of the shell is critically reliant on 3,4-dihydroxyphenylalanine's (Dopa) ability to form reversible iron-catecholate complexes at pH 8. However, the formation of these coordinate cross-links is undercut by Dopa's oxidation to Dopa-quinone, a spontaneous process at seawater conditions. The large mechanical mismatch between the cuticle and the core lends itself to further complications. Despite these challenges, the mussel byssus thread performs its tethering function over long periods of time. Here, we address these two major questions: (1) how does the mussel slow/prevent oxidation in the cuticle, and (2) how is the mechanical mismatch at the core/shell interface mitigated? By combining a number of microscopy and spectroscopy techniques we have discerned a previously undescribed layer. Our results indicate this interlayer is thiol rich and thus will be called the thiol-rich interlayer (TRL). We propose the TRL serves as a long-lasting redox reservoir as well as a mechanical barrier

Use of the Plate-Waste Method to Measure Food Intake in Children

Childhood overweight is increasing in the U.S. and is often associated with excess food intake. Because children consume at least one meal in school approximately half the days each year, it is important to develop accurate and cost-effective methods to measure food intake in schools. We compared the aggregated plate waste method with actual weighed food measurements. The aggregated plate waste measurements were similar to the energy and macronutrient intake determined by weighed food measurements. The plate waste methodology is a simple and accurate method that can be implemented by Extension professionals and teachers to assess children\u27s energy intake

Entangling Spins in Double Quantum Dots and Majorana Bound States

We study the coupling between a singlet-triplet qubit realized in a double quantum dot to a topological qubit realized by spatially well-separated Majorana bound states. We demonstrate that the singlet-triplet qubit can be leveraged for readout of the topological qubit and for supplementing the gate operations that cannot be performed by braiding of Majorana bound states. Furthermore, we extend our setup to a network of singlet-triplet and topological hybrid qubits that paves the way to scalable fault-tolerant quantum computing

Analog Sensing Front-End System for Harmonic Signal Classification

This paper presents the design of an Analog-to- Information spectral decomposition scheme suitable for parallel low-power analog and mixed-signal VLSI implementation. The novel scheme extracts sufficient information to achieve good back end signal detection and classification performance while using less power than purely digital spectral techniques such as FFT. Simulations of a prototype system in a mixed-signal 130nm CMOS process show a feasible solution space given an on-line self-calibrating system