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The kinetics of aluminum corrosion product release was examined in solutions representative of post-LOCA sump water for both pressurized water and pressurized heavy-water reactors. Coupons of AA 6061 T6 were exposed to solutions in the pH 7–11 range at 40, 60, 90 and 130 °C. Solution samples were analyzed by inductively coupled plasma atomic emission spectroscopy, and coupon samples were analyzed by secondary ion mass spectrometry. The results show a distinct “boron effect” on the release kinetics, expected to be caused by an increase in the solubility of the aluminum corrosion products. New models were developed to describe both sets of data as functions of temperature, time, and pH (where applicable). [ABSTRACT FROM AUTHOR]

Presents a number of ideas and scientific definitions as reported by 9-12-year-olds in class discussions, essays or examination papers at the Ballwin Elementary School in Ballwin, Missouri. Living body; Gastral and other tracts; Metabolism and energy; Audition and vision; Skeletal design and locomotion; Heart; Respiratory ailments and their prevention; Neuroscience trends; Concepts of genetics; Basic microbiology.

The article presents a study which analyzed tobacco smoke using thermal desorption (TD) and two-dimensional gas chromatography (GCxGC) with time-of-light mass spectrometry aided by tandem ionisation for simultaneous acquisition of hard and soft electron ionisation (EI) data. Using the technique, smoke constituents were sampled, separated and identified. Experimental procedure is described in detail.

White Island volcano, New Zealand, produced two periods (January–February and July 2013) of episodic and persistent eruptions through a viscous shallow mud/sulphur pool. The eruptions included an initial hemispherical bubble burst, which was intermittently followed by an up-channel gas jet, and finally a late stage heaving of a mud/sulphur/water suspension. The late stage heave was systematically directed south-eastward as far as 30–40 m from the vent. The associated infrasound time-series included harmonic tremor on permanent stations WIZ and WSRZ. Detailed inspection showed that the tremor was composed of numerous discrete double pulse events without a strong periodic event repetition. The first pulse had highly similar waveforms event-to-event and a notable distortion of the waveform period between the two infrasound stations located on opposites sides from the directed eruption source. The second pulse occurred about 1.5–2.5 s later and was weakly observed on station WSRZ. Where the video can be rigorously linked to the double pulse infrasound signals we interpret aspects of the distinctive eruptive regimes. For this case, the regime dynamics are driven by the propagation of numerous discrete gas slugs though the shallow viscous muddy crater lake, each generating a distinct bubble burst with subsequent eruption heave and associated double pulse infrasound events. The double pulse events are the source of the persistent harmonic tremor having fundamental and overtone spectral frequencies but are not interpreted as related to cavity resonance or a repetitious comb function. Instead the activity is produced by a single event producing a specific two pulse source time function. The observed distortion in the first pulse wave period at WIZ and WSRZ may be ascribed to a Doppler shift associated with the directivity observed in the initial jet/heave eruption process. We surmise that double pulse source dynamics and directivity effects may be generically extended to some examples of subsurface seismic tremor or for tremor associated with geyser eruptions, mud volcano eruptions, fire fountains from lava lakes and strombolian eruptions. [ABSTRACT FROM AUTHOR]

The changing global climate is having profound effects on coastal marine ecosystems around the world. Structure, functioning, and resilience, however, can vary geographically, depending on species composition, local oceanographic forcing, and other pressures from human activities and use. Understanding ecological responses to environmental change and predicting changes in the structure and functioning of whole ecosystems require large‐scale, long‐term studies, yet most studies trade spatial extent for temporal duration. We address this shortfall by integrating multiple long‐term kelp forest monitoring datasets to evaluate biogeographic patterns and rates of change of key functional groups (FG) along the west coast of North America. Analysis of data from 469 sites spanning Alaska, USA, to Baja California, Mexico, and 373 species (assigned to 18 FG) reveals regional variation in responses to both long‐term (2006–2016) change and a recent marine heatwave (2014–2016) associated with two atmospheric and oceanographic anomalies, the "Blob" and extreme El Niño Southern Oscillation (ENSO). Canopy‐forming kelps appeared most sensitive to warming throughout their range. Other FGs varied in their responses among trophic levels, ecoregions, and in their sensitivity to heatwaves. Changes in community structure were most evident within the southern and northern California ecoregions, while communities in the center of the range were more resilient. We report a poleward shift in abundance of some key FGs. These results reveal major, ongoing region‐wide changes in productive coastal marine ecosystems in response to large‐scale climate variability, and the potential loss of foundation species. In particular, our results suggest that coastal communities that are dependent on kelp forests will be more impacted in the southern portion of the California Current region, highlighting the urgency of implementing adaptive strategies to sustain livelihoods and ensure food security. The results also highlight the value of multiregional integration and coordination of monitoring programs for improving our understanding of marine ecosystems, with the goal of informing policy and resource management in the future. [ABSTRACT FROM AUTHOR]

The Clymene dolphin ( Stenella clymene) is endemic to warm Atlantic Ocean waters and is one of the least known delphinids. We reviewed existing published data (primarily strandings, captures, and bycatch) and unpublished sightings to examine the distribution, habitat, group size, seasonality, and pigmentation patterns of Clymene dolphins within the eastern tropical Atlantic (ETA). Following photographic verification, 84 confirmed and 8 probable at-sea sightings of ETA Clymene dolphins were analyzed. The documented records ranged from ∼19°N in central Mauritania to 14°26′S in southern Angola, confirming 14 ETA range states. At-sea sightings occurred in water depths of 437-5,000 m and at distances from shore of 21-937 km, corresponding with a continental slope and oceanic habitat. Sightings within the wider ETA region had year-round occurrence. Group size ranged from 3-1,000 animals, with 60.9% of groups comprising ≤ 50 animals. Photographic examination revealed a complex and variable pigmentation pattern in ETA Clymene dolphins, which contrasts with the simple tripartite pattern often described for this species. In particular, most ETA animals had a dark gray lateral stripe extending diagonally along the flank from the beak to the genital area and a conspicuous dark gray eye-flipper stripe of varying intensity and thickness. The at-sea sightings documented here significantly extend current knowledge of the distribution, ecology, and appearance of the Clymene dolphin. [ABSTRACT FROM AUTHOR]

Latitudinal gradients in species abundance and diversity have been postulated for nearshore taxa but few analyses have been done over sufficiently broad geographic scales incorporating various nearshore depth strata to empirically test these gradients. Typically, gradients are based on literature reviews and species lists and have focused on alpha diversity across the entire nearshore zone. No studies have used a standardized protocol in the field to examine species density among sites across a large spatial scale while also focusing on particular depth strata. The present research used field collected samples in the northern hemisphere to explore the relationships between macroalgal species density and biomass along intertidal heights and subtidal depths and latitude. Results indicated no overall correlations between either estimates of species density or biomass with latitude, although the highest numbers of both were found at mid-latitudes. However, when strata were examined separately, significant positive correlations were found for both species numbers and biomass at particular strata, namely the intertidal ones. While the data presented in this paper have some limitations, we show that latitudinal macroalgal trends in species density and biomass do exist for some strata in the northern hemisphere with more taxa and biomass at higher latitudes. [ABSTRACT FROM AUTHOR]

Italian ryegrass is a major weed problem in wheat (Triticum aestivum L.) production worldwide. Two separate studies were conducted in Stoneville, Mississippi to evaluate: (1) the efficacy of herbicides available to Mississippi producers for controlling glyphosate-resistant (GR) Italian ryegrass (control study), and (2) fall burndown herbicide seed suppression study. Results of the control study showed that flufenacet/metribuzin EPOST followed by (fb) pinoxaden LPOST (standard treatment) provided 93% control of GR Italian ryegrass. Some other treatments provided comparable Italian ryegrass control (92% to 97%) as the standard treatment in 2017. Italian ryegrass control in the seed suppression study was 100%, 100%, 67.5%, 97%, and 99.5% from the application of the following treatments: (1) S-metolachlor + flumioxazin + paraquat in October–November fb glyphosate + clethodim in January–February fb gramoxone as needed (weed-free check); (2) S-metolachlor + flumioxazin + paraquat in October–November; (3) field cultivator (disk) in October–November; (4) glyphosate + clethodim in January–February; and (5) field cultivator in October–November fb glyphosate + clethodim in January–February, respectively. The remaining Italian ryegrass from the application of treatments 3, 4, and 5 produced 65,700; 1008; and 9 seeds m−2, respectively. Seed suppression study highlights the importance of 100% control that is required to manage GR Italian grass. [ABSTRACT FROM AUTHOR]