1,542 research outputs found
On the photosynthetic responses of crops to intracanopy lighting with light emitting diodes
Key words: Cucumis sativus, intracanopy lighting, light-emitting diodes (LEDs), light distribution, light interception, light quality, photosynthesis, photosynthetic acclimation Assimilation lighting is a production factor of increasing importance in Dutch greenhouse horticulture. Assimilation lighting increases production levels, improves product quality and opens possibilities for year round production. As a drawback, this use of assimilation lighting increases energy inputs and CO2-emission. Intracanopy lighting (with LEDs) is a technique to enhance the light use efficiency by changing the position of (a part of ) the lamps from above to within the canopy of greenhouse grown crops. Intracanopy lighting (IL) firstly reduces reflection and transmission losses of the supplemental lighting on crop level. These losses are high in traditional top-lighting systems, hence IL yields a higher light absorption on crop level. Secondly, IL creates a more homogenous vertical light distribution which can result in higher light use efficiencies. The aim of present study was to obtain insights in photosynthetic acclimation in response to irradiance level and spectrum in the framework of the applicability of LEDs as light source for intracanopy lighting in indeterminate growing vegetable crops. Intracanopy lighting may vary in (1) position within the crop, in (2) irradiance level and in (3) spectrum. Leaves deeper in the canopy are older. If leaf age negatively affects the photosynthetic capacity (Amax), then potential positions of IL-lamps reduce. By growing tomato plants horizontally so that irradiance was similar for all leaves from 0-70 days old, it is concluded that during the normal life-span of tomato leaves in cultivation, irradiance and not ageing is the most important factor affecting Amax. In winter, natural irradiances are low so that new developing leaves acclimate to low irradiances. Later on in their life time these leaves could be exposed to higher irradiances owing to IL. The question arose if cucumber leaves which develop under low irradiance can acclimate to a moderate irradiance. Acclimation of photosynthesis occurred within 7 days but photosynthesis at moderate irradiance and Amax did not reach to that of leaves developed under moderate irradiance. This reveals the importance of photosynthetic acclimation during the leaf developmental phase for crop productivity in scenarios with realistic, moderate fluctuations in irradiance that leaves can be exposed to. By growing plants under seven different combinations of red and blue light, blue light is shown to have both a qualitative and a quantitative effect on leaf development. Only leaves developed under red light (0% blue) displayed a dysfunctional photosynthetic operation (“red light syndrome”), which was largely alleviated by only 7% blue. Quantitatively, leaf responses to an increasing blue light percentage resembled responses associated with an increase in irradiance. Leaves developed under red light exposed to a mixture of red and blue (RB) completely recovered within 4 days after exposure to RB-light but remained limited in other leaf parameters, showing limitations in plasticity due to constraints arising from the prior leaf development. Leaves developed under RB also revealed the “red light syndrome” within 7 days of red illumination. Lastly, the effects of intracanopy lighting with LEDs on the production and development of a cucumber crop was investigated in winter. In the IL-treatment, LEDs supplied 38% of the supplemental irradiance within the canopy; the remaining 62% was supplied as top lighting by High-Pressure Sodium (HPS) lamps. The control was 100% top lighting (HPS lamps). Intracanopy lighting resulted in a greater Amax for leaves at deeper canopy layers but did not increase total biomass or fruit production. This was partly due to a reduced light interception caused by extreme leaf curling, which counteracted the expected higher light absorption by the crop, and partly to a lower dry matter partitioning to the fruits, and thus a greater dry matter partitioning to the leaves compared to the control. The effect of these factors on fruit yield was quantified using a explanatory crop model. Model calculations revealed a large negative effect on the fruit yield due to the greater partitioning to the leaves, whereas the negative effect of leaf curling was small. The effect of a greater Amax at deeper canopy layers was slightly positive. The last however might have indirectly caused the greater partitioning to the leaves as the greater Amax was associated with a preserved leaf mass per area. </p
Carboxylation of carbenes in low-temperature matrixes
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What Is It Like to Be a Bat-Author? Viktor Pelevin's Empire V
In this paper, Viktor Pelevin's novel Empire V (2006) is analysed, with its main concern with the status of language, in fiction as well as in contemporary Russian culture. The work is seen as a kind of sequel to Generation 17: whereas that novel predominantly focused on the problem of consciousness, its problematical relation with reality, but expressed this problem in language, in Empire V the problem of language as the form of consciousness is foregrounded; inevitably thus the status of the text we are reading and the relation it has to its author is problematized - as is the relation it has to its reader. It is a text that reflects on what language, its material, does. The possibility is suggested that this novel tries to rind a way out of postmodernism's anxieties about the conscious personality being an illusion, created by his own language.</p
What Is It Like to Be a Bat-Author? Viktor Pelevin's Empire V
In this paper, Viktor Pelevin's novel Empire V (2006) is analysed, with its main concern with the status of language, in fiction as well as in contemporary Russian culture. The work is seen as a kind of sequel to Generation 17: whereas that novel predominantly focused on the problem of consciousness, its problematical relation with reality, but expressed this problem in language, in Empire V the problem of language as the form of consciousness is foregrounded; inevitably thus the status of the text we are reading and the relation it has to its author is problematized - as is the relation it has to its reader. It is a text that reflects on what language, its material, does. The possibility is suggested that this novel tries to rind a way out of postmodernism's anxieties about the conscious personality being an illusion, created by his own language.</p
Experimental validation of nonlinear Fourier transform-based Kerr-nonlinearity identification over a 1600km SSMF link
Recently, a nonlinear Fourier transform-based Kerr-nonlinearity identification algorithm was demonstrated for a 1000 km NZDSF link with accuracy of 75%. Here, we demonstrate an accuracy of 99% over 1600 km SSMF. Reasons for improved accuracy are discussed.Accepted Author ManuscriptTeam Sander Wahl
What Is It Like to Be a Bat-Author? Viktor Pelevin's Empire V
In this paper, Viktor Pelevin's novel Empire V (2006) is analysed, with its main concern with the status of language, in fiction as well as in contemporary Russian culture. The work is seen as a kind of sequel to Generation 17: whereas that novel predominantly focused on the problem of consciousness, its problematical relation with reality, but expressed this problem in language, in Empire V the problem of language as the form of consciousness is foregrounded; inevitably thus the status of the text we are reading and the relation it has to its author is problematized - as is the relation it has to its reader. It is a text that reflects on what language, its material, does. The possibility is suggested that this novel tries to rind a way out of postmodernism's anxieties about the conscious personality being an illusion, created by his own language.</p
From Sander to Schiavo: Morality, Partisan Politics, and America’s Culture War over Euthanasia, 1950–2010
The article discusses cultural conflicts and social policies regarding euthanasia in the United states from 1950 to 2010. The author highlights high-profile legal cases related to euthanasia including, the trial of Dr. Herman Sander, the first U.S. physician to stand trial for euthanasia, the case surrounding the termination of coma-patient Terri Schiavo's life support, and the trial of physician Jack Kevorkian. Other topics discussed include the impact of moral activism on politics, U.S. President Ronald Reagan's views on euthanasia, and the U.S. Supreme Court's rulings in euthanasia cases
Desain Rangka Mesin Bandsaw Dan Belt Sander
Progress in the increasingly developing field of technology is an aspect of knowledge and technology that requires higher education to be able to increase their ability to master technology. The purpose of converting energy to machines is to help make human work easier. Plywood/wood cutting machine saw from manual becomes a useful machine for Bengkalis State Polytechnic students. The objectives are 1. To make it easier for the user when cutting plywood, 2. To find out the design process for the bandsaw machine frame and belt sander, 3. To know the planning procedures for the bandsaw machine frame design and belt sander. Study literature used by the author by looking for references related to design to create a project.
In this process, the authors designed a bandsaw and belt sander frame design where the design will be designed in such a way and function as a reference in the process of making the tool, this tool uses an unp iron frame 80 x 45 x 5 mm and hollow iron 30 x 30 x 1.8 mm by using a 1-phase electric motor and also using 2 wheels. This bandsaw saw machine is for cutting plywood and wood of small and large sizes. Belt sander for the sanding process after cutting which is a design with a scale of 1:100.
Keywords: Design Bandsaw And Belt Sander Desig
sj-pdf-1-jcb-10.1177_0271678X231179413 - Supplemental material for Cerebrovascular glycocalyx damage and microcirculation impairment in patients with temporal lobe epilepsy
Supplemental material, sj-pdf-1-jcb-10.1177_0271678X231179413 for Cerebrovascular glycocalyx damage and microcirculation impairment in patients with temporal lobe epilepsy by Rick HGJ van Lanen, Roel HL Haeren, Julie Staals, Jim TA Dings, Olaf EMG Schijns, Govert Hoogland, Sander MJ van Kuijk, Dimitris Kapsokalyvas, Marc AMJ van Zandvoort, Hans Vink and Kim Rijkers in Journal of Cerebral Blood Flow & Metabolism</p
Single-channel 1.61 Tb/s optical coherent transmission enabled by neural network-based digital pre-distortion
We propose a novel digital pre-distortion (DPD) based on neural networks for high-baudrate optical coherent transmitters. We demonstrate experimentally that it outperforms an optimized linear DPD giving a 1.2 dB SNR gain in a 128GBaud PCS-256QAM single-channel transmission over 80km of standard single-mode fiber resulting in a record 1.61 Tb/s net data rate.Accepted Author ManuscriptTeam Sander Wahl
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