Relation between gas absorptivities and emissivities

N/

Biofouling Effects on the Response of a Wave Measurement Buoy in Deep Water

AbstractThe effects of biofouling on a wave measurement buoy are examined using concurrent data collected with two Datawell Waveriders at Ocean Station P: one heavily biofouled at the end of a 26-month deployment, the other newly deployed and clean. The effects are limited to the high-frequency response of the buoy and are correctly diagnosed with the spectral “check factors” that compare horizontal and vertical displacements. A simple prediction for the progressive change in frequency response during biofouling reproduces the check factors over time. The bulk statistical parameters of significant wave height, peak period, average period, and peak direction are only slightly affected by the biofouling because the contaminated frequencies have very low energy throughout the comparison dataset.</jats:p

Sixteen years of bathymetry and waves at San Diego beaches.

Sustained, quantitative observations of nearshore waves and sand levels are essential for testing beach evolution models, but comprehensive datasets are relatively rare. We document beach profiles and concurrent waves monitored at three southern California beaches during 2001-2016. The beaches include offshore reefs, lagoon mouths, hard substrates, and cobble and sandy (medium-grained) sediments. The data span two energetic El Niño winters and four beach nourishments. Quarterly surveys of 165 total cross-shore transects (all sites) at 100 m alongshore spacing were made from the backbeach to 8 m depth. Monthly surveys of the subaerial beach were obtained at alongshore-oriented transects. The resulting dataset consists of (1) raw sand elevation data, (2) gridded elevations, (3) interpolated elevation maps with error estimates, (4) beach widths, subaerial and total sand volumes, (5) locations of hard substrate and beach nourishments, (6) water levels from a NOAA tide gauge (7) wave conditions from a buoy-driven regional wave model, and (8) time periods and reaches with alongshore uniform bathymetry, suitable for testing 1-dimensional beach profile change models

California cooperative oceanic fisheries investigations. Reports volume 37, January 1--December 31, 1995

Scientists from the California Department of Fish and Game (CDFG), the Southwest Fisheries Science Center of the National Marine Fisheries Service (NMFS), and the Scripps Institution of Oceanography, University of California, San Diego (UCSD), have collaborated for 46 years in the longest-running large-scale study ever undertaken in the ocean. This study was begun in order to understand the causes of changes in population, over time, of commercially important fishes in California`s coastal waters. When the study began, the Pacific sardine was by far the most significant species of economic concern to the State of California. Because its population changes were thought to be caused by a diversity of atmospheric, oceanic, and biological variables, a wide array of measurements in the California Current region were begun and have been continued to this day. This long time series of data allows not only a better understanding of the flux of fish populations, but also lays the foundation for understanding interdecadal and secular change in the seas. This document contains papers from symposium of the 1995 CalCOFI Conference related to interdecadal changes in the ecology of the California current

Advancing CCU Technologies Pursuant to the SDGs: A Challenge for Policy Making

The implementation of the United Nations Sustainable Development Goals (SDGs) is indispensable for building a sustainable and just future for all humans and our planet. The SDGs are global goals. However, their implementation equally calls for action by a variety of actors in government, business, and civil society. Thus, policy making as well as industrial innovation efforts need to be designed to facilitate rather than hinder the implementation of the SDGs. Consequently, it is necessary to ensure that the possible environmental, economic, and societal impacts of technological innovations aiming for public support and funding in research, development, and market implementation are aligned with the respective objectives of the SDGs. Carbon capture and utilization (CCU) applications are an example of such innovations. By capturing and utilizing CO2, they are intended to have positive impacts on economy, society, and environment. Next to industries’ own efforts to advance such technologies, CCU is currently funded by governments in several countries, and such funding is likely to increase. Therefore, an assessment of the compatibility of CCU technologies with the SDGs is as much necessary as it is overdue. Hence, this paper elucidates on how CCU might contribute to or hinder the delivery of the SDGs. By comparing CCUs against the SDGs, it can be concluded that, under certain conditions, they might deliver contributions to several SDGs. The main contributions are expected within the context of energy transition processes, and in societal advancements that are linked to technological progress. For eight out of the seventeen SDGs, positive and indirect negative effects can be predicted. Therefore, the development and implementation of CCU aligned with the SDGs poses a challenge for policy makers when designing frameworks and funding schemes. Specific risks need to be monitored and considered in policy making. This paper therefore argues that the SDGs should be used as a framework for assessing potential societal effects of CCU technologies. The findings demonstrate that such an approach is necessary in order to identify and enhance the positive (and avoid indirect negative) effects that CCU technologies might have on people, prosperity and planet

Different stress-related phenotypes of BALB/c mice from in-house or vendor: alterations of the sympathetic and HPA axis responsiveness

<p>Abstract</p> <p>Background</p> <p>Laboratory routine procedures such as handling, injection, gavage or transportation are stressful events which may influence physiological parameters of laboratory animals and may interfere with the interpretation of the experimental results. Here, we investigated if female BALB/c mice derived from in-house breeding and BALB/c mice from a vendor which were shipped during their juvenile life differ in their HPA axis activity and stress responsiveness in adulthood.</p> <p>Results</p> <p>We show that already transferring the home cage to another room is a stressful event which causes an increased HPA axis activation for at least 24 hours as well as a loss of circulating lymphocytes which normalizes during a few days after transportation. However and important for the interpretation of experimental data, commercially available strain-, age- and gender-matched animals that were shipped over-night showed elevated glucocorticoid levels for up to three weeks after shipment, indicating a heightened HPA axis activation and they gained less body weight during adolescence. Four weeks after shipment, these vendor-derived mice showed increased corticosterone levels at 45-min after intraperitoneal ACTH challenge but, unexpectedly, no acute stress-induced glucocorticoid release. Surprisingly, activation of monoaminergic pathways were identified to inhibit the central nervous HPA axis activation in the vendor-derived, shipped animals since depletion of monoamines by reserpine treatment could restore the stress-induced HPA axis response during acute stress.</p> <p>Conclusions</p> <p>In-house bred and vendor-derived BALB/c mice show a different stress-induced HPA axis response in adulthood which seems to be associated with different central monoaminergic pathway activity. The stress of shipment itself and/or differences in raising conditions, therefore, can cause the development of different stress response phenotypes which needs to be taken into account when interpreting experimental data.</p

The Social Acceptance of Carbon Dioxide Utilisation: A Review and Research Agenda

CO2 utilisation technologies—also called carbon dioxide utilisation (CDU) and carbon capture and utilisation (CCU)—convert CO2 via physical, chemical, or biological processes into carbon-based products. CO2 utilisation technologies are viewed as a means of helping to address climate change and broadening the raw material base for commodities that can be sold to generate economic revenue. However, while technical research and development into the feasibility of CO2 utilisation options are accelerating rapidly; at present, there has been limited research into the social acceptance of the technology and CO2-derived products. This review article outlines and explores three key dimensions of social acceptance (i.e., socio-political, market, and community acceptance) pertaining to innovation within CO2 utilisation. The article highlights the importance of considering issues of social acceptance as an aspect of the research, development, demonstration, and deployment process for CO2 utilisation and explores how key stakeholders operating on each dimension might affect the innovation pathways, investment, and siting decisions relating to CO2 utilisation facilities and CO2-derived products. Beyond providing a state-of-the-art review of current research into the social acceptance of CO2 utilisation, this article also outlines an agenda for future research in the field

Experimental and modelling study of fatigue crack initiation in an aluminium beam with a hole under 4-point bending

Slip band formation and crack initiation during cyclic fatigue were investigated by in-situ experiments and non-local CPFEM simulations systematically. Experimental techniques including EBSD, digital image correlation (DIC) and SEM have been used to obtain consistent grain orientations, local strains, as well as the locations where slip bands and micro-cracks form on the sample surface. The realistic microstructure based on the EBSD map has been generated and used for finite element modelling. An advanced non-local crystal plasticity model, which considers the isotropic and kinematic hardening of the plastic strain gradient, has been adopted. The simulation results match well the corresponding experimental results. It was found that total strain and averaged slip on all slip systems, combined with accumulated slip on specific slip planes help predict the location and orientation of slip bands and micro-crack initiation correctly. Furthermore, a fatigue indicating parameter based on competition between maximum slip and the total slip has been proposed to reproduce the experimental observations

Attitude control research with educational nanosatellites

This paper introduces the three-axis attitude control of the ESAT platform. ESAT is a modular nanosatellite that implements the popular 10x10x10 cm CubeSat standard, designed for hands-on learning at different educational levels as well as professional training. ESAT features the full set of characteristic spacecraft subsystems (power, on-board data handling, attitude control, communications, and payload). The satellite can be disassembled to focus on each subsystem, one at a time, or used all together, and features a flexible ground segment. Courses using the ESAT platform are imparted in our university, as part of the last year of the master’s degree in Aerospace engineering, and in other institutions like the ESA Academy. They cover aspects ranging from subsystems design to testing and spacecraft operations. In addition, the platform is used in master’s thesis and research activities. Although the version that is currently being used in the courses allows only one-axis attitude control, the ESAT is in continuous development and two prototypes of the satellite have already been developed that allow three-axis control based on reaction wheels and/or magnetorquers, which is essential for the testing and verification of attitude determination and control algorithms. For this purpose, the ground support equipment has also been updated to be able to carry out the turns in three axes, with the development of new testbeds and a complete magnetic field simulator. The present work aims to show the new three-axis platform designs and its main functionalitie