By collecting more data at a higher resolution and by creating the capacity to implement detailed crop management, autonomous crop equipment has the potential to revolutionise precision agriculture (PA), but unless farmers find autonomous equipment profitable it is unlikely to be widely adopted. The objective of this study was to identify the potential economic implications of autonomous crop equipment for arable agriculture using a grain-oilseed farm in the United Kingdom as an example. The study is possible because the Hands Free Hectare (HFH) demonstration project at Harper Adams University has produced grain with autonomous equipment since 2017. That practical experience showed the technical feasibility of autonomous grain production and provides parameters for farm-level linear programming (LP) to estimate farm management opportunities when autonomous equipment is available. The study shows that arable crop production with autonomous equipment is technically and economically feasible, allowing medium size farms to approach minimum per unit production cost levels. The ability to achieve minimum production costs at relatively modest farm size means that the pressure to “get big or get out” will diminish. Costs of production that are internationally competitive will mean reduced need for government subsidies and greater independence for farmers. The ability of autonomous equipment to achieve minimum production costs even on small, irregularly shaped fields will improve environmental performance of crop agriculture by reducing pressure to remove hedges, fell infield trees and enlarge fields.
Chemical sensors based on individual single-walled carbon nanotubes (SWNTs) are demonstrated. Upon exposure to gaseous molecules such as NO(2) or NH(3), the electrical resistance of a semiconducting SWNT is found to dramatically increase or decrease. This serves as the basis for nanotube molecular sensors. The nanotube sensors exhibit a fast response and a substantially higher sensitivity than that of existing solid-state sensors at room temperature. Sensor reversibility is achieved by slow recovery under ambient conditions or by heating to high temperatures. The interactions between molecular species and SWNTs and the mechanisms of molecular sensing with nanotube molecular wires are investigated. 相似文献
In situ atomic force microscope observations were made of the adsorption of anions (1- or 2-) of the organic diacid 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid from aqueous solution onto the (0001) surface of hydrotalcite (HT), a layered clay. This adsorption process is believed to mimic the ion-exchange reactions that occur within the layers of HT and other layered clays. Atomic force microscope images of the (0001) surfaces of HT, acquired in aqueous solutions, reveal an ordered structure with respect to magnesium and aluminum atoms. In the presence of the anions, atomic force microscopy indicates pH-dependent adsorption onto the formally cationic HT surface. The anion coverage is governed by electroneutrality and steric interactions between the bulky anions within the adsorbed layer, whereas the orientation of the anions with respect to the HT surface is dictated by coulombic interactions and hydrogen bonding between the anion's sulfonate moiety and clay hydroxyl triads. These observations reveal that the reversible adsorption of molecular species can be examined directly by in situ atomic force microscopy, providing details of surface stoichiometry and adlayer symmetry on the local, molecular level. 相似文献
The objective of these studies was to find alternative Rapid Visco Analyser (RVA) viscoelastic parameters that are predictable by near‐infrared spectroscopy (NIRS). Currently, RVA instruments are widely used in assessing cooking and processing characteristics in rice. The ability to predict RVA parameters by NIRS would be useful in rapidly determining rice pasting qualities, but NIRS does not correlate with the traditional parameters (peak viscosity, final viscosity, breakdown, consistency, and setback). Alternative RVA parameters were sought by collecting RVA and NIRS data for a total of 86 short, medium, and long grain rice cultivars. The amylose contents were 0.41–24.90% (w/w) and protein concentrations were 8.47–11.35% (w/w). Partial least squares (PLS) regression models generated for the entire NIR spectrum against the RVA curve showed viscosity at 212–228 sec (80°C ± 1) varied linearly with NIR spectra (1,100 to ‐2,500 nm). Regression coefficient values were R = 0.961 for 212 sec and R = 0.903 for 228 sec. The PLS correlation coefficient for the prediction of amylose at 212–228 sec decreases along with the NIRS correlation to the same time frame. An opposite trend was observed for the correlation with protein at 212–228 sec. This comparison suggests the importance of amylose and protein in water absorption during this time frame. 相似文献
Interdisciplinary data fuel fisheries oceanography research and the ecosystem-based approaches to management and sustainable development it informs. Underlying this is a distributed ocean observing framework that is integrated, interoperable, interactive, and accessible. In recognition of the 30th anniversary of Fisheries Oceanography the journal, this paper reviews the evolution of observing instruments and platforms used in contemporary fisheries oceanography the science. Illustrated with personal anecdotes, past efforts to create or adopt observing technologies, and examples of their use in research, this highlights the spectrum of instruments, systems, and programs used to survey and monitor ocean ecosystems. Modern ocean observing systems are complex and varied, reflecting the range and diversity of data required by fisheries oceanographers. These systems require a large and ongoing investment and an interdisciplinary community of scientists, engineers, and technicians to design, build, install, operate, and maintain them. Common themes emerge from a review of past successful instrument R&D and deployments. It is a highly collaborative, integrative, and iterative process. Most systems are the result of vision, planning, and perseverance, backed by careful calibration and intercomparison. Long-term support is essential; public–private partnerships that leverage funding, technology, and infrastructure are critical. Sustaining long time series for monitoring population and ecosystem change and to support fisheries oceanography research is a priority. Future areas of focus include continuously innovating and updating technologies, implementing a backbone of core observations, and maintaining a nimble infrastructure and R&D capacity to seize new opportunities and address emerging challenges. 相似文献