Hazen Research (United States)

Abstract Bacterial cellulose (BC) has unique properties such as high tensile strength, high crystallinity, and high purity. Fiber length of BC causes different attributes. Therefore, degradation of BC has been studied deeply. In this study, fibers of BC were rearranged via DMAc-LiCl solvent and BC was degraded in wet state. Two different degradation methods, milling with liquid nitrogen and autoclave treatment, were applied. Degraded BCs were characterized by FTIR, TEM, AFM, TGA, and XRD. The solvent helps to align the fibers, making it more crystalline. Degraded BCs had lower crystalline ratio than BC, because of increasing hydrogen bonding during degradation in wet state. Degradation with autoclave made two different degraded BCs as nanofibrils and spherical nanocrystals with no pretreatment and solvent pretreatment, respectively. The nanofibril lengths were between 312 – 700 nm depending on applied method and spherical nanocrystal size was 56 nm. The rearrangement via solvent causes an important difference in degradation of BC. Nanofibrils and nanocrystals can be obtained, depending on the rearrangement of fibers before degradation process.

Significant academic research and moderate commercial process innovation on rare-earth element (REE) processing have been underway for decades. The last several years have seen exponential growth in research due to growth in demand of REE that is threatened by supply risks and environmental obstacles. The REE industry appears to be at the intersection of strong, but conflicting forces, including public and political support for a Green Revolution and sustainability, as well as the need for a clean, reliable, and socially responsible supply chain. REE recoveries from ore are limited by current technology and plant practice to 50–80 percent. Increasing demand can be partially satisfied by recycling, but reliable and continuous increases in supply will also require new mineral resources, improved process efficiency, and lower production costs. This article reviews and summarizes the past and current REE processing technologies, commonly employed REE separation routes and methods, and suggests ways to increase efficiency in future REE processing.Graphical abstractExample of a bastnäsite from the Mountain Pass Mine, CA, and (b) monazite concentrate from the Manchester Mine, NJ.

The geological mapping carried out by William Smith, which resulted in the publication of his famous map in 1815, was remarkable in many respects, not least because it relied on him being able to make consistent and accurate observations on the rock types he encountered during his fieldwork. This ability, gained from his many years studying rocks, allowed him to observe features with his own eyes (or at the very least, with the aid of a simple magnifying device) that others could not. We take a new look at William Smith's original stratigraphical sequences, and with samples collected from his classic field areas (many of which are around the city of Bath, Somerset, UK), demonstrate how spatial mineralogy mapping can be incorporated into the modern age of digital mapping.

Schoharie Reservoir is part of the Catskill System, and one of three systems that supply water to the city of New York. Approximately 35% of the city’s average daily demand is provided by the Catskill System, of which about 25% is supplied by the Schoharie Reservoir. The construction of Gilboa Dam was completed in 1926 and is comprised of a 700-ft-long earth embankment with a concrete core wall, and a 1,324-ft-long cyclopean concrete spillway with a maximum height of 160 ft. Like many reservoirs in the northeast, the capacity of the release works became restricted due to the age of the mechanical equipment, silting at outlet locations, and changes in release needs since the time of original reservoir construction. The final design of the low level outlet (LLO) was completed in June of 2014 and the project was bid in late fall of 2014 followed by award to SRJV and notice to proceed for construction in June of 2015. The project is scheduled to be completed in June of 2020 and when completed will represent one of the largest microtunnel boring machine project installations with wet retrieval ever accomplished in the United States. The 2100 linear feet of 108-in diameter Permalok steel casing will be installed in the tunnel while maintaining normal operating conditions of the Schoharie Reservoir at all times. This paper places particular emphasis on the practical applications from the view point of the owner, engineer, and manufacturer. Areas of interest include planning and design of the tunnel, the selection of tunnel lining materials, the Permalok steel casing manufacturing process, and key tunnel planning, design, and construction elements.

Rationale: Trimethylamine N-oxide (TMAO), a metabolite formed in the metabolism of dietary phosphatidylcholine, is elevated in the circulation of patients at increased risk for heart attack and adverse prognosis during heart failure. Objective: We investigated the effects of dietary choline and TMAO on the severity of heart failure following transverse aortic constriction (TAC). Methods and Results: Male C57Blk/6J mice were fed either control diet, a diet containing choline (1.2%) or a diet containing TMAO (0.12%) at 3 weeks prior to surgical TAC and were studied for 12 weeks. Left ventricular (LV) structure and function were monitored at 3 week intervals and myocardial tissue was collected at 12 weeks. Plasma TMAO levels were significantly (p < 0.01) increased in the choline (28.64 ± 2.30 μM) and TMAO (28.18 ± 4.27 μM) compared to the control group (1.87 ± 0.26 μM). Left ventricular ejection fraction (LVEF) was significantly (p < 0.05) worse in mice fed TMAO compared to control diet. LV end-diastolic and end-systolic diameters were significantly (p < 0.05) increased in the TMAO group compared to control diet. Myocardial fibrosis as measured with Picrosirius Red staining was also significantly greater (p < 0.01) in the TMAO and choline groups. Circulating BNP levels were significantly (p < 0.05) increased in the TMAO and choline groups. Conclusions: These data demonstrate that heart failure severity is significantly enhanced in mice fed diets containing either TMAO or choline. Our results suggest that consumption of food high in dietary nutrients that increase TMAO levels such as phosphatidylcholine may increase heart failure severity.

This chapter contains sections titled: Introduction Experimental Plan Results and Discussion Conclusions