Nitrogen dynamics in the intact grasses Poa trivialis and Panicum maximum receiving contrastaing suplies of nitrogen.

The C 3 grass Poa trivialis and the C 4 grass Panicum maximum were grown in sand culture and received a complete nutrient solution with nitrogen supplied as 1.5 mol m -3 NH 4NO 3. 15 N tracer techniques were used to quantify the relative use of root uptake and mobilization in supplying nitrogen to growing leaves in intact plants which either continued to receive nitrogen or which received the complete nutrient solution without nitrogen. The allocation of both 15 N-labelled nitrogen uptake and unlabelled mobilized nitrogen indicated that, under their conditions of growth, the sink strength of growing leaves was relatively greater in P. maximum than P. trivialis. The supply of nitrogen by mobilization to side tillers of P. trivialis was completely stopped as the external nitrogen supply was reduced, whilst in P. maximum some allocation of mobilized nitrogen to side tillers, roots and growing leaves was maintained. In both plant species receiving an uninterrupted supply of nitrogen the allocation pattern of mobilized nitrogen differed from that of nitrogen derived from root uptake. Differences exist in the degree to which P. trivialis and P. maximum utilized uptake and mobilization to supply nitrogen to the growing leaves. In P. trivialis roots were always a net sink of mobilized nitrogen, irrespective of the external nitrogen supply. In P. maximum, roots were a net sink of mobilized nitrogen when external nitrogen was withdrawn, but exhibited both source and sink behaviour when nitrogen supply was continued.Made available in DSpace on 2011-04-09T21:34:25Z (GMT). No. of bitstreams: 1 PROCIPMS2002.00088.PDF: 449187 bytes, checksum: e0414636039ff5d9a2120355d4b8a8fb (MD5) Previous issue date: 2002-12-0

Sealing farm ponds in Missouri

Missouri Agricultural Experiment Station and the United States Department of Agriculture cooperating.Digitized 2007 AES.Includes bibliographical references (page 28)

APECS’ Online Conference, Virtual Posters and Webinars to the World

The Association of Polar Early Career Scientists (APECS) is a multidisciplinary, international organization dedicated to maintaining a network of early career researchers (ECRs) and professionals (ECPs) to share ideas, develop collaborative research directions, provide opportunities for career development, and promote education and outreach as an integral component of Polar research. Science outreach is one of APECS’ key objectives and we have found that online media is a powerful tool for STEAM (Science, Technology, Engineering, Art, and Mathematics) knowledge transfer. We introduce the use of online presentations as a platform for communication, education, and networking. APECS’ Online Conference, virtual posters, and webinar series provide case studies to examine how online technology bridges geographic and disciplinary boundaries. APECS’ Online Conference allows ECRs and ECPs to present their research to an interactive, online room of viewers. The third iteration of this annual event (March 2017) appealed to science communicators with the theme: “Outside the Box: encouraging alternative solutions for undertaking and communicating polar research”. Virtual poster sessions have allowed members to share work on an array of topics, from whaling and tourism to showcasing studies affiliated with specific national research programs. Webinars have covered a variety of skills-based and scientific topics, with invited speakers addressing everything from writing grant proposals to eco-cultural communication. Each presentation is recorded and saved on APECS’ website as a free resource. ECRs, ECPs, and APECS mentors from around the world attend our events, promoting diversity in networking and helping steer the Arctic community in positive directions. We will provide examples of connections fostered by and benefits of online events, including easier dissemination of ideas across geographically distant regions and minimal cost. While this presentation focuses on APECS’ experiences, we will highlight how innovative communication promotes international cooperation and offer suggestions on how to incorporate similar elements into other outreach programs

Structural and electrical properties of CuAlMo thin films prepared by magnetron sputtering

The structural and electrical properties of a low resistivity CuAlMo thin film resistor material were investigated. The thin films were grown on Al2O3 and glass substrates by direct current (dc) magnetron sputtering. The key electrical properties of sheet resistance, temperature coefficient of resistance (TCR) and resistance stability were investigated as a function of sputtering pressure and post-deposition heat treatment time and temperature. A low sputtering pressure range of 0.13 to 0.40 Pa produced CuAlMo films with sheet resistance in the range 0.1 to 0.2 Ω/□ and resistance stability of 0.45 to 0.65% with a TCR of − 90 ppm/°C which could be shifted to zero following annealing in air at 425 °C. Films grown at higher sputtering pressures of 0.53 to 0.80 Pa had increased sheet resistance in the range 0.4 to 0.6 Ω/□ and inferior stability of 0.8 to 1.7% with a more negative TCR of − 110 to − 180 ppm/°C which could not be shifted to zero following annealing. The stability of the films grown at 0.13 and 0.40 Pa could be further improved to < 0.25% with heat treatment, due to the formation of a protective aluminium oxide layer. A minimum dwell time of 3 h at 425 °C was required to stabilise the films and set the electrical properties

Damage detections in nonlinear vibrating thermally loaded plates

In this work, geometrically nonlinear vibrations of fully clamped rectangular plates subjected to thermal changesare used to study the sensitivity of some vibration response parameters to the presence of damage and elevated temperature. The geometrically nonlinear version of the Mindlin plate theory is used to model the plate behaviour.Damage is represented as a stiffness reduction in a small area of the plate. The plates are subjected to harmonicloading leading to large amplitude vibrations and temperature changes. The plate vibration response is obtained by a pseudo-load mode superposition method. The main results are focussed on establishing the influence of damage on the vibration response of the heated and the unheated plates and the change in the time-history diagrams and the Poincaré maps caused by damage and elevated temperature. The damage criterion formulated earlier for nonheated plates, based on analyzing the points in the Poincaré sections of the damaged and healthy plate, is modified and tested for the case of plates additionally subjected to elevated temperatures. The importance of taking into account the actual temperature in the process of damage detection is shown

Evaluating regional emission estimates using the TRACE-P observations

Measurements obtained during the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) experiment are used in conjunction with regional modeling analysis to evaluate emission estimates for Asia. A comparison between the modeled values and the observations is one method to evaluate emissions. Based on such analysis it is concluded that the inventory performs well for the light alkanes, CO, ethyne, SO2, and NOₓ. Furthermore, based on model skill in predicting important photochemical species such as O₃, HCHO, OH, HO₂, and HNO₃, it is found that the emissions inventories are of sufficient quality to support preliminary studies of ozone production. These are important finding in light of the fact that emission estimates for many species (such as speciated NMHCs and BC) for this region have only recently been estimated and are highly uncertain. Using a classification of the measurements built upon trajectory analysis, we compare observed species distributions and ratios of species to those modeled and to ratios estimated from the emissions inventory. It is shown that this technique can reconstruct a spatial distribution of propane/benzene that looks remarkably similar to that calculated from the emissions inventory. A major discrepancy between modeled and observed behavior is found in the Yellow Sea, where modeled values are systematically underpredicted. The integrated analysis suggests that this may be related to an underestimation of emissions from the domestic sector. The emission is further tested by comparing observed and measured species ratios in identified megacity plumes. Many of the model derived ratios (e.g., BC/CO, SOₓ/C₂H₂) fall within ∼25% of those observed and all fall outside of a factor of 2.5. (See Article file for details of the abstract.)Department of Civil and Environmental EngineeringAuthor name used in this publication: Wang, T

APECS as an Arctic Stakeholder: Training Future Leadership of the Polar Research Community

The Association of Polar Early Career Scientists (APECS) is an international, interdisciplinary NGO for undergraduate and graduate students, postdoctoral researchers, early career professionals, educators, and others interested in polar regions and the wider cryosphere. The existence of APECS as a stakeholder is fundamental towards developing diverse future leadership in the Arctic community. Celebrating its 10th anniversary in 2017, APECS has grown from a small group established during the 2007/08 International Polar Year (IPY) to a global community of more than 2,300 actively-engaged early career researchers (ECRs) and professionals (ECPs) interested in the polar regions, from over 60 countries; within the last decade, more than 7,500 individuals joined our network during the early stages of their careers. APECS creates opportunities for innovative collaborations and information exchange amongst ECRs and established professionals, thereby helping to recruit, retain, increase cooperation amongst, and promote future polar experts. APECS works with polar organizations to enable skilled early career representatives to contribute to their goals and projects, including the International Arctic Science Committee (IASC) and the Arctic Council Working Groups ‘Arctic Monitoring and Assessment Programme’ (AMAP) and ‘Conservation of Arctic Flora and Fauna’ (CAFF). In these capacities, APECS members contribute to the scientific activities of the working groups, synthesizing research to identify and address areas of concern to Arctic ecosystems, communities, and Arctic residents. This presentation discusses how APECS contributes to training future leadership in the Arctic community and how members influence polar science and policy. We highlight how APECS updates activities to reflect scientific, policy, and environmental challenges in order to provide the most relevant resources to our members. Early engagement of ECRs and ECPs develops a workforce more adept to bridging the divide between scientific research and sustainable development in the Arctic and, therefore, is an investment in the future of the Arctic

Regional-scale chemical transport modeling in support of the analysis of observations obtained during the TRACE-P experiment

Data obtained during the TRACE-P experiment is used to evaluate how well the CFORS/STEM-2K1 regional-scale chemical transport model is able to represent the aircraft observations. Thirty-one calculated trace gas and aerosol parameters are presented and compared to the in situ data. The regional model is shown to accurately predict many of the important features observed. The mean values of all the model parameters in the lowest 1 km are predicted within ±30% of the observed values. The correlation coefficients (R) for the meteorological parameters are found to be higher than those for the trace species. For example, for temperature, R \u3e 0.98. Among the trace species, ethane, propane, and ozone show the highest values (0.8 \u3c R \u3c 0.9), followed by CO, SO2, and NOy, NO and NO2 had the lowest values (R \u3c 0.4). Analyses of pollutant transport into the Yellow Sea by frontal events are presented and illustrate the complex nature of outflow. Biomass burning from SE Asia is transported in the warm conveyor belt at altitudes above ∼2 km and at latitudes below 30N. Outflow of pollution emitted along the east coast of China in the postfrontal regions is typically confined to the lower ∼2 km and results in high concentrations with plume-like features in the Yellow Sea. During these situations the model underpredicts CO and black carbon (among other species). An analysis of ozone production in this region is also presented. In and around the highly industrialized regions of East Asia, where fossil fuel usage dominates, ozone is NMHC-limited. South of ∼30-35N, ozone production is NOx-limited, reflecting the high NMHC/NOx ratios due to the large contributions to the emissions from biomass burning, biogenics sources, and biofuel usage in central China and SE Asia. Copyright 2003 by the American Geophysical Union

Alien Registration- Thorton, Mary (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/24397/thumbnail.jp

The Black Belt Environmental Science and Arts Program

The goal of the Black Belt Environmental Science and Arts Program (BBSEAP) is to enhance classroom instruction in the environmental sciences for students in grades 5-8 of selected counties in Alabama\u27s Black Belt region. BBSEAP differs from traditional outreach activities in that public school students come to off-campus, outdoor sites for instruction. The Auburn University Environmental Institute (AUEI) administers the program with support from local Alabama Cooperative Extension System (ACES) representatives. Since 2005, more than 2,000 students have participated in the program. Funding for BBESAP comes from government and corporate grants