A Chemical Analysis of Apatite and Zircon Composition From Four Minnesotan Ordovician K-Bentonite Deposits

We analyzed the geochemical composition of zircon and apatite crystals found in samples of volcanic tuff collected from four distinct Ordovician volcanic eruptions (Deicke, Dickeyville, Elkport and Millbrig) of the North American Midcontinent, to better understand the compositional relationships between minerals from the same magmas and their use for distinguishing the products of volcanic eruptions. Crystals were imaged using cathodoluminescence (CL) on a scanning electron microscopy (SEM) prior to in situ analysis of 22 trace elements via laser ablation inductively coupled plasma mass spectrometry (ICP-MS). Data were compared with previously published studies on other samples of these deposits. Line scans (12x75x6 μm) were ablated from candidate grains parallel to the c-axis at both core and rim locations on \u3e30 crystals to assess compositional differences within and between grains. Common elements between apatite and zircon were compared to determine if trends observed in both minerals were consistent within and between deposits. Additional anomalies were explored, such as the correlation with CL response, and inference of inherited cores encased in younger rims in both minerals. Preliminary analysis indicates similar zircon compositions across the tuffs, compared with distinct compositional differences for exchangeable cations in apatite

Influence of pyrolyzed grape-seeds/sewage sludge blends on the availability of P, Fe, Cu, As and Cd to maize

Current intensive agricultural practices, although highly successful in terms of production, have been found to be environmentally unsustainable. One of the crucial approaches to increase agricultural sustainability is the recycling of organic wastes, since these materials often contain many beneficial nutrients for soil and agriculture. Recently, pyrolytic conversion of biodegradable waste into charred material has gained global attention as an amendment to recycle nutrients while improving soil health. Increasing interest in the beneficial applications of pyrolyzed biomass has expanded multidisciplinary areas for science and engineering. The fertilizers used in this study were prepared by pyrolyzing mixtures of two abundant residues in Mediterranean areas: grape seeds and sewage sludge, in different proportions (100% GS, 75% GS-25% SS, 50% GS-50% SS, 25% GS-75% SS, 100% SS). In addition, fresh sludge was mixed with pyrolyzed grape seeds and included as an additional treatment. In this study, the positives and negatives of the application of biochars on agronomic potential and environmental risk have been addressed, taking into account P, Zn, Cu, Fe, As and Cd. In order to choose the best mixture, it is necessary to find a compromise between maximizing the beneficial elements that are translocated to the plant crop, as well as reducing the elements that are leached. Results of a 6-week greenhouse study indicated that the unpyrolyzed sludge mixture contained the largest amount of available nutrients Fe, Cu and P. In agreement, this treatment mixed with a Chromic Luvisol soil (40 ton/ha) increased the uptake of these elements in corn (Zea mays L.—LG ambitious). The yield also increased by 60% in this treatment. However, this mixture also contained more contaminants (As, Cd) which were extracted with Ammonium Bicarbonate-DTPA. According to our results, the treatments where grape seeds and sewage sludge were mixed at 50% and then pyrolyzed exhibited the optimal compromise between efficiency (nutrients uptake) and tolerable levels of potentially toxic elements in leachates.Part of this research was funded by Project UAM-Santander 2017/ASIA/0

Low-loss, submicron chalcogenide integrated photonics with chlorine plasma etching

A chlorine plasma etching-based method for the fabrication of high-performance chalcogenide-based integrated photonics on silicon substrates is presented. By optimizing the etching conditions, chlorine plasma is employed to produce extremely low-roughness etched sidewalls on waveguides with minimal penalty to propagation loss. Using this fabrication method, microring resonators with record-high intrinsic Q-factors as high as 450 000 and a corresponding propagation loss as low as 0.42 dB/cm are demonstrated in submicron chalcogenide waveguides. Furthermore, the developed chlorine plasma etching process is utilized to demonstrate fiber-to-waveguide grating couplers in chalcogenide photonics with high power coupling efficiency of 37% for transverse-electric polarized modes

Cardiovascular disease in late survivors of tetralogy of Fallot: A tertiary care center experience

Patients with tetralogy of Fallot can survive to late adulthood; however, there are few data on cardiovascular outcomes in this population. We conducted a single-center retrospective analysis of cardiovascular outcomes and risk factors in 208 patients with tetralogy of Fallot to better evaluate the burden of cardiovascular disease in this group. Descriptive statistics were used to determine the prevalence of relevant cardiovascular risk factors and outcomes, including a composite analysis of cardiovascular disease. Rates and mean values from the American Heart Association 2011 Heart Disease and Stroke Statistics Update were used as population estimates for comparison. In tetralogy of Fallot patients, cardiovascular disease prevalence was not different from that found in the general population (40% vs 36%, P=0.3). However, there was significantly more cardiovascular disease in tetralogy of Fallot men aged 20 to 39 years (30% vs 14%, P < 0.05) and in tetralogy of Fallot men aged 40 to 59 years (63% vs 29%, P < 0.0001). This was due to higher prevalence of coronary disease (12% vs 7%, P < 0.05) and heart failure (16% vs 2%, P < 0.0001). In particular, the increased prevalence of heart failure (regardless of pulmonary valve disease) accounts for the frequency of cardiovascular disease in tetralogy of Fallot men aged 20 to 59 years. These data support the need to routinely screen young adult male survivors of tetralogy of Fallot for asymptomatic heart failure. Further studies are needed to determine the incidence, severity, and long-term effects of cardiovascular disease in the adult congenital heart disease population

BFORE: The B-mode Foreground Experiment

The B-mode Foreground Experiment (BFORE) is a proposed NASA balloon project designed to make optimal use of the sub-orbital platform by concentrating on three dust foreground bands (270, 350, and 600 GHz) that complement ground-based cosmic microwave background (CMB) programs. BFORE will survey ~1/4 of the sky with 1.7 - 3.7 arcminute resolution, enabling precise characterization of the Galactic dust that now limits constraints on inflation from CMB B-mode polarization measurements. In addition, BFORE's combination of frequency coverage, large survey area, and angular resolution enables science far beyond the critical goal of measuring foregrounds. BFORE will constrain the velocities of thousands of galaxy clusters, provide a new window on the cosmic infrared background, and probe magnetic fields in the interstellar medium. We review the BFORE science case, timeline, and instrument design, which is based on a compact off-axis telescope coupled to >10,000 superconducting detectors.Comment: 7 pages, 4 figures, conference proceedings published in Journal of Low Temperature Physic

Influence of Corn Stover Harvest on Soil Quality Assessments at Multiple Locations Across the U.S.

Corn (Zea mays L.) stover has been identified as a biofuel feedstock due to its abundance and a perception that the residues are unused trash material. However, corn stover and other plant residues play a role in maintaining soil quality (health) and enhancing productivity, thus use of this abundant material as feedstock must be balanced with the need to protect the vital soil resource. Plant residues provide physical protection against erosion by wind and water, contribute to soil structure, nutrient cycling, and help sustain the soil microbiota. Replicated plots were established on productive soils at several locations (IA, IN, MN, NE, PA, SD, and SC) and a multi-year study was carried out to determine the amount of corn stover that can be removed while maintaining the current level of soil quality for each soil. These sites represented a range of soil types and climatic conditions, and have been ongoing for and least five years with some much longer studies. All sites had at least three levels of stover harvest: grain only (control), maximum removal (90-100%) and a mid-range removal rate (~50%). Data from 4 sites are presented (IA, IN, MN, and NE). The Soil Management Assessment Framework (SMAF) was used to score and assess changes in selected soil quality indicators. Data shows that removal at the highest rates resulted in some loss in soil quality with respect to soil organic carbon and bulk density. These sites were converted to no-till when the experiments were initiated, thus SOC accrual because of the shift in tillage management appeared to balance any losses due to feedstock harvest

Overview of the MEDLI Project

The Mars Science Laboratory Entry, Descent, and Landing Instrumentation (MEDLI) Project s objectives are to measure aerothermal environments, sub-surface heatshield material response, vehicle orientation, and atmospheric density for the atmospheric entry and descent phases of the Mars Science Laboratory (MSL) entry vehicle. The flight science objectives of MEDLI directly address the largest uncertainties in the ability to design and validate a robust Mars entry system, including aerothermal, aerodynamic and atmosphere models, and thermal protection system (TPS) design. The instrumentation suite will be installed in the heatshield of the MSL entry vehicle. The acquired data will support future Mars entry and aerocapture missions by providing measured atmospheric data to validate Mars atmosphere models and clarify the design margins for future Mars missions. MEDLI thermocouple and recession sensor data will significantly improve the understanding of aeroheating and TPS performance uncertainties for future missions. MEDLI pressure data will permit more accurate trajectory reconstruction, as well as separation of aerodynamic and atmospheric uncertainties in the hypersonic and supersonic regimes. This paper provides an overview of the project including the instrumentation design, system architecture, and expected measurement response