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21.
Validation of plant part measurements using a 3D reconstruction method suitable for high-throughput seedling phenotyping 总被引:2,自引:0,他引:2
Franck Golbach Gert Kootstra Sanja Damjanovic Gerwoud Otten Rick van de Zedde 《Machine Vision and Applications》2016,27(5):663-680
In plant phenotyping, there is a demand for high-throughput, non-destructive systems that can accurately analyse various plant traits by measuring features such as plant volume, leaf area, and stem length. Existing vision-based systems either focus on speed using 2D imaging, which is consequently inaccurate, or on accuracy using time-consuming 3D methods. In this paper, we present a computer-vision system for seedling phenotyping that combines best of both approaches by utilizing a fast three-dimensional (3D) reconstruction method. We developed image processing methods for the identification and segmentation of plant organs (stem and leaf) from the 3D plant model. Various measurements of plant features such as plant volume, leaf area, and stem length are estimated based on these plant segments. We evaluate the accuracy of our system by comparing the measurements of our methods with ground truth measurements obtained destructively by hand. The results indicate that the proposed system is very promising. 相似文献
22.
Gert A. Schultz 《国际水》2013,38(1):96-109
Abstract Presently a change of paradigm in the field of planning and operation of water management schemes can be observed. The introduction of the principle of sustainable development by the United Nations and the principle of integrated river basin management postulated by the European Union play a major role in this context. Introduction of these new principles requires development of new planning tools, which in turn require a much better data basis than available hitherto. This paper deals with new data types already partly available now, partly to be expected to be developed in the medium-range future. The present data situation is discussed, along with the obvious deficits of conventional data. New data types will not be limited to point measurements, but rather must comprise information covering large areas with a higher resolution in time and space than presently available. Remote sensing data will play a more important role in the future. Furthermore, digital maps, digital elevation models, etc. are also of growing importance and will be processed, together with remote sensing and other data, within Geographical Information Systems of future generations also exposing the potential for working with multi-temporal imagery. In the paper it is shown that in the future more accurate data will be available, not only in terms of data quality, but also resolution in time and space. It is shown how the new types of hydrometeorological data postulate new types of hydrological models. Here, distributed system models are of growing importance. Furthermore, it is shown how the combination of remote sensing with other information leads to new data types that allow integrated planning of water resources systems. The potential of real time data is highlighted, particularly in the context of real time operation of water resources systems, especially for flood control. The potential of large-scale data schemes in the context of regional and continental water management schemes is discussed. Global atmospheric models coupled to hydrological models are discussed, and their potential to consider long-distance effects of certain phenomena (e.g., El Niño) are mentioned. For sustainable development of water resources, the potential of long-term data prediction scenarios is evaluated, and an example of this principle for planning future water supply systems is presented. The paper ends with a vision of future developments in planning water management schemes on the basis of new data types 相似文献
23.
Nils von Preetzmann Philipp Eckmann Adriaan M. H. van der Veen Jianrong Li Markus Richter 《American Institute of Chemical Engineers》2021,67(4):e17128
Exact knowledge of natural gas composition is essential in custody transfer to determine the energy content of the delivery. However, for liquefied natural gas (LNG), a reliable composition determination is difficult. Here, we describe the design of a laboratory-scale reference liquefier that enables the validation and calibration of optical spectroscopy sensors by providing them with a sample of metrologically traceable composition. Hence, it is crucial to avoid fractionation of the sample during liquefaction. This is realized by supercritical liquefaction of a reference gas mixture in conjunction with a special vapor–liquid-equilibrium (VLE) cell. As this is a demanding high-pressure application, low-pressure condensation as liquefaction method was also assessed. Through experimental investigations and VLE calculations, preservation of the composition of the produced liquid sample during condensation was studied. We conclude that under optimized conditions, validation, and calibration measurements of optical sensors can be performed on condensed liquids, which, however, needs further confirmation. 相似文献
24.
Valéria Nagy Roland Tengölics Gert Schansker Gábor Rákhely Kornél L. Kovács Győző Garab Szilvia Z. Tóth 《International Journal of Hydrogen Energy》2012
The green alga Chlamydomonas reinhardtii is capable of photoproducing molecular hydrogen following sulphur deprivation, which results in anaerobiosis and a suppression of oxygen evolution and thus an alleviation of the inhibitory effect of oxygen on the hydrogenase. At the same time it transiently maintains a limited supply of electrons arising from photosystem II (PSII) to the hydrogenase (Melis and Happe Plant Physiol 2001; 127:740–748). In this work, using fast chl a fluorescence and P700 measurements, we show that ascorbate (Asc), a naturally occurring PSII alternative electron donor, is capable of donating electrons to PSII in heat-treated and sulphur-deprived cells and this can be significantly accelerated by supplementing the culture with 10 mM Asc. It also enhances, about three-fold, the photoproduction of hydrogen in cells subjected to sulphur deprivation as shown by gas chromatography. Similar stimulation was obtained in the presence of diphenylcarbazide (DPC), an artificial PSII electron donor. Asc and DPC also facilitated the anaerobiosis of cells, probably via super reducing the oxygen evolving complex while feeding electrons to PSII reaction centres and the linear electron transport chain, and ultimately to the hydrogenase – as shown by the significant DCMU-sensitivity of the light-induced Asc- and DPC-dependent re-reduction of P700+ and hydrogen evolution. 相似文献
25.
Dr. techn. Dr. tekn. h.c. Prof. Emeritus J?rgen Bach Andersen M.Sc. Ph.D. Prof. Gert Fr?lund Pedersen 《e & i Elektrotechnik und Informationstechnik》2012,129(6):383-386
In future mobile communications many antennas will coexist on the device. This creates a number of problems related to bandwidth, efficiency, and correlation. Remedies are discussed in the paper, and attention is called to the promising area of adaptive matching, which also can solve problems related to the user. 相似文献
26.
Glycoalkaloids in potato-derived products result in bitter taste and potentially toxic effects at high intakes. Generally, extraction of glycoalkaloids prior to HPLC analysis is carried out by dilute acetic acid. For most potato-derived extracts including heat-coagulated potato proteins, this extraction method is sufficient to achieve satisfying tri-glycoalkaloid (TGA) recoveries. Soluble potato proteins obtained by non-denaturing processes show different requirements for glycoalkaloid extraction. TGA extraction was optimized for two commercially available native potato protein isolates and compared to heat-coagulated potato protein. The highest TGA levels were determined in the extract when extraction was carried out at 40 °C by at least 5 % acetic or propionic acid supplemented with 20 mM Na-1-heptanesulfonate (HSA). Addition of HSA results in substantially improved TGA extraction and induces precipitation of soluble protein which enhanced sample cleanup. On the contrary, extraction of TGA from coagulated potato protein in the presence of HSA showed a reduced TGA extraction efficiency. This improved TGA extraction procedure for soluble non-denatured potato protein isolates results in reliable quantification of bitter tasting and toxic glycoalkaloid levels. This contributes to a non-bitter and safe use of the nutritional and functional benefits of this plant protein in food applications. 相似文献
27.
28.
Chongxin Yuan N.Bert Roozen Otto Bergsma Adriaan Beukers 《Engineering Analysis with Boundary Elements》2013,37(2):250-259
The aircraft fuselage is idealized as a composite cylinder, its vibroacoustic properties are studied both experimentally and numerically, and a minimization of the inner pressure of a composite cylinder is conducted with the genetic algorithm (GA). In the optimization, the Acoustic Transfer Vector (ATV), which comes from the boundary element method, builds the relationship between the structural surface velocity and the sound pressure at the specific filed points. Results show that the noise reduction obtained by the experimental and numerical methods have a good agreement; the optimization method which combines GA and ATV show high efficiency and robustness; increase of the bending stiffness of the cylinder can improve the noise reduction at low frequencies; both the reduction of weight and the increase of noise insulation can be achieved by the optimization of the layup at different regions of the cylinder individually. 相似文献
29.
Controlling micro‐ and nanofibrillar morphology of polymer blends in low‐speed melt spinning process. Part II: Influences of extrusion rate on morphological changes of a PLA/PVA blend through a capillary die 下载免费PDF全文
Nguyen Hoai An Tran Harald Brünig Maria Auf der Landwehr Roland Vogel Jürgen Pionteck Gert Heinrich 《应用聚合物科学杂志》2016,133(47)
The effects of the extrusion rate on the morphological changes of poly(lactic acid) (PLA)/poly(vinyl alcohol) (PVA) blend through a capillary die were investigated. In this study, the extrusion rate or mass flow rate is altered from 0.5 g min?1 to 2 g min?1 with an increment of 0.5 g min?1. The PLA/PVA blend with a composition of 30/70 (wt %) exhibits a particle matrix morphology with dispersed PLA droplets within the PVA matrix. It is found that, the spherical or ellipsoidal dispersed PLA droplets are elongated and coalesced into rod‐like or longer ellipsoidal droplets when they pass through the capillary die. When the extrusion rate increases, the coalescence between the large PLA droplets occurs more intense. However, the changes of the extrusion rate have no strong effect on the coalescence of small droplets having diameter less than about 150 nm. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44257. 相似文献
30.
Melt spun matrix fibers of toughened polypropylene copolymers modified by high energy electrons 下载免费PDF全文
Binary blends of polypropylene (PP) and ethylene‐octene copolymer (EOC) are prepared by continuous electron‐induced reactive processing at various mass ratios of the blend components and various doses without adding of any grafting agents. The influence of mass ratio and dose is investigated in order to get the optimum processing behavior of toughened PP as well as optimum properties of resulting fibers. It is found that toughened PP with a PP/EOC blend ratio of 97.5–2.5 mass % can be used advantageously as a matrix component for the process of online spinning of glass fiber/toughened PP hybrid yarns. Such hybrid yarns belong to one of the most advanced production methods for the manufacturing of fiber reinforced thermoplastic composites with an increased mechanical performance. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44011. 相似文献