4,894 research outputs found
Assessment of sensor performance
There is an international commitment to develop a comprehensive, coordinated and sustained ocean observation system. However, a foundation for any observing, monitoring or research effort is effective and reliable in situ sensor technologies that accurately measure key environmental parameters. Ultimately, the data used for modelling efforts, management decisions and rapid responses to ocean hazards are only as good as the instruments that collect them. There is also a compelling need to develop and incorporate new or novel technologies to improve all aspects of existing observing systems and meet various emerging challenges.
Assessment of Sensor Performance was a cross-cutting issues session at the international OceanSensors08 workshop in Warnem├╝nde, Germany, which also has penetrated some of the papers published as a result of the workshop (Denuault, 2009; Kr├╢ger et al., 2009; Zielinski et al., 2009). The discussions were focused on how best to classify and validate the instruments required for effective and reliable ocean observations and research. The following is a summary of the discussions and conclusions drawn from this workshop, which specifically addresses the characterisation of sensor systems, technology readiness levels, verification of sensor performance and quality management of sensor systems
Determination of metabolic rates and quotients in fish
Before any growth can be,achieved by an organism
there must be sufficient energy in the food to provide for
the metabolic demands of maintenance and any activity associated
with food intake. In culture practices it is possible
to reduce these energy costs to a minimum and to optimize
food conversion. This can be done through an understanding
of the environmental and biological factors affecting metabolic
rate with a view to reduce the demands on the system
and hence increase the production. It is therefore desirable
to examine the broad picture of energy exchange within an
animal; then proceed to more specific considerations in fish.
Since it is the principles and prospects which are of major
interest here, no attempt is made to make this a major review
of the subject
Rapid Physical Models: A New Phase in Industrial Design
Rapid prototyping, especially in the form of 3D printing, has pervaded over key aspects of design engineering since the start of this millennium. Today, rapid physical model making has applications in engineering, architecture, design, and fine art. While 3D printing today is mostly about prototyping of design as a precursor to production, not many have studied the use of 3D for industrial design in detail. With core responsibilities for three important nodes of user experience, namely function, human factors (ergonomics) and the aesthetics and emotion, 3D printing has been playing a major role in the process of industrial design. This chapter elucidates this through examples leading the reader to think about the future practice of rapid physical model making in industrial design. The chapter concludes by mentioning future scenarios that industrial design may take with constant innovations in 3D printing
Transportation of live Finfishes and Shellfishes
Livefish trade, especially the live ornamental fish and live seafood trade, is
emerging as a major business venture in most of the tropical countries. Production
of livefish through aquaculture has also undergone vast changes during the past
20 years. In aquaculture, transport of broodstock from the wild to the hatchery or
seed from the hatchery to the growouts forms one of the basic requirements. The
demandfor livefiriflsh and shellfish is rapidly increasir^g and in most of the developed
countries, more and more livefish traders and restaurants are offering live fishery
products to their customers. Air liftiry of live se<^ood has also increased during the
last few years. The mcgor constraint to the development of live seafood export is
the lack of information on handling the aquatic organisms after they are caught,
right through the transport and sale to the customers. Necessary precautions have
to be taken while catching, packing and transporting the aquatic organisms. Apart
from careful handling, a thorough knowledge of the behaviour and physiology of the
animal is necessary to minimise the stress during storage and transportation
Some investigations on the activity of phenol oxidase in the isopod Cirolana fluviatilis
Phenol oxidase activity in the isopod Cirolana fluviatilis averaged 0.0015 w.units/mg protein/min in the larger isopod.samples (10-17 mg) and 0.00034 O.D. units/mg protein/min in the smaller samples (6-9 mg). The enzyme showed equal affinity for epinephrine and dopamine and >5O% affinity for DOPA
Significance of farm-made feeds in the Indian context
The bulk of shrimp production comes
from semi-intensive farming in the
brackish water systems. The nutritional requirements of shrimpalong
with their feeding in these systems is complex and poorly understood primarily due to the difficulties encountered
in quantifying the contribution of
naturally available food organisms
Status of feed management
Feed management is playing a vital role in aquaculture as half of the operational cost comes from feed. Great care must be taken unless the farmer will incur loss
The role of symmetry in driven propulsion at low Reynolds number
We theoretically and experimentally investigate low-Reynolds-number
propulsion of geometrically achiral planar objects that possess a dipole moment
and that are driven by a rotating magnetic field. Symmetry considerations
(involving parity, , and charge conjugation, )
establish correspondence between propulsive states depending on orientation of
the dipolar moment. Although basic symmetry arguments do not forbid individual
symmetric objects to efficiently propel due to spontaneous symmetry breaking,
they suggest that the average ensemble velocity vanishes. Some additional
arguments show, however, that highly symmetrical (-even) objects
exhibit no net propulsion while individual less symmetrical
(-even) propellers do propel. Particular magnetization
orientation, rendering the shape -odd, yields
unidirectional motion typically associated with chiral structures, such as
helices. If instead of a structure with a permanent dipole we consider a
polarizable object, some of the arguments have to be modified. For instance, we
demonstrate a truly achiral (- and -even)
planar shape with an induced electric dipole that can propel by
electro-rotation. We thereby show that chirality is not essential for
propulsion due to rotation-translation coupling at low Reynolds number.Comment: 5 pages, 5 figure
The Traded Water Footprint of Global Energy from 2010 to 2018
The energy-water nexus describes the requirement of water-for-energy and energy-for-water. The consumption of water in the production and generation of energy resources is also deemed virtual water. Pairing the virtual water estimates for energy with international trade data creates a virtual water trade network, facilitating analysis of global water resources management. In this database, we identify the virtual water footprints for the trade of eleven different energy commodities including fossil fuels, biomass, and electricity. Additionally, we provide the necessary scripts for downloading and pairing trade data with the virtual water footprints to create a virtual water trade network. The resulting database contains country-to-country virtual water trade from 2010тАУ2018, broken down by commodity. The purpose of this data descriptor is to provide detailed methods and validation of the dataset beyond the complementary research publication. The resulting database provides opportunities to understand global energy-related water demands and advance future global water resources research
An Integrated Assessment of the Global Virtual Water Trade Network of Energy
The global trade of energy allows for the distribution of the world\u27s collective energy resources and, therefore, an increase in energy access. However, this network of trade also generates a network of virtually traded resources that have been used to produce energy commodities. An integrated database of energy trade water footprints is necessary to capture interrelated energy and water concerns of a globalized economy,and is also motivated by current climate and population trends. Here, we quantify and present the virtual water embedded in energy trade across the globe from 2012 to 2018, building on previous water footprinting and energy virtual water trade studies to create an integrated database. We use data from the United Nations Comtrade database and combine several literature estimates of water consumption of energy commodities to generate the global virtual water trade network. Results include a comprehensive database of virtual water trade for energy at the country level, greatly expanding the literature availability on virtual water trade. The total volume of virtual water trade increased 35% from 157 km3 in 2012 to 211 km3 in 2018. The global trade of oil and fuelwood are consistent drivers of virtual water trade over time, whereas coal, hydrocarbons, and charcoal collectively contribute less than 4% of total virtual water trade between 2012 and 2018. Electricity, despite a less dense trade network constrained by infrastructure, contributes notably to virtual water trade, driven largely by water use for hydroelectricity. This study develops an integrated assessment of previous virtual water studies to estimate global virtual water trade of energy, creating a platform for future global studies
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