Shading Rate Research Articles

Açık Köklü Asma Fidanı Üretiminde Farklı Malç Materyalleri ve Gölgeleme Oranlarının Fidan Randımanı ve Kalitesine Etkileri

Bu çalışmada; arazi koşullarında farklı malç materyalleri (tekstil, beyaz ve siyah Mogul, üstü gri altı siyah malç, siyah plastik malç ve malçsız-kontrol) ve gölgeleme (Kontrol, %35, ve %55) oranlarının açık köklü asma fidan randıman ve kalitesine etkisini saptamak amaçlanmıştır. Çalışmada anaç olarak 1613 C ve çeşit olarak Sultani Çekirdeksiz kullanılmıştır. Çalışma sonucunda gölgeleme uygulamalarından sürgün gelişim düzeyi; malç uygulamalarından ise sürgün gelişim düzeyi, sürgün uzunluğu, I ve II. boy fidan randımanı ve toplam randıman etkilenmiştir. En fazla sürgün uzunluğu (110 cm) ve en fazla toplam fidan randımanı (%78) % 35 gölge altında siyah plastik malçtan elde edilmiştir.

An Embedded Reconfiguration for Reliability Enhancement of Photovoltaic Shaded Panels Against Hot Spots

The reliability of conventional photovoltaic (PV) structure in shaded situations can undergo different issues related to internal and external conditions. The internal condition accounts for the inhomogeneity of the properties of electrothermal cells, while the external conditions connote optimal power maximum tracking techniques and protection circuit limitations. This article proposes a new technique to improve the reliability of shaded panels, considering the internal and the external issues. Our study begins with an extensive analysis to assess the vulnerability of PV cells to second-quadrant thermal stress and operational limits of bypass diode protection against hot spot. Consequently, we proposed a new system that concurrently operates with the maximum power extraction process to assist bypass diodes with hot-spot protection. This proposition results in a reconfigured panel with both a local detection circuit that defines the conduction states of bypass diodes and additional mosfet s that switch shaded subgroups. In this article, an algorithm was developed that is capable of controlling the optimal maximum operation point tracking with an on-demand deployment of the protection mosfet s, using the signals provided by the local detection circuit. A set of experiments were carried out in order to demonstrate the capability of the proposed method to prevent hot-spot damages over all shading rates and operating points. The novelty of the proposed approach is its low cost of implementation as well as its simple and efficient design. Therefore, it has the potential to be easily integrated along side existing infrastructure and maximum power point tracking algorithms.

Effects of shading on chlorophyll content and photosynthetic characteristics in leaves of Phoebe bournei.

To explore the photosynthetic adaptation of Phoebe bournei to different light conditions, two-year-old P. bournei seedlings were grown under three light regimes (full light, shading rate 50% and 78% of full light). The chlorophyll contents, leaf gas exchange and chlorophyll fluorescence of P. bournei were measured after six-month treatment. The results showed that the contents of chlorophyll a, chlorophyll b, chlorophyll (a+b) and carotenoids in leaves were in a descending order of shading rate 78% > shading rate 50% > full light. There was no significant difference of chlorophyll a/b between natural and shade treatments. The shading treatment reduced light compensation point (LCP), but increased light saturation point (LSP) and apparent quantum yield (AQY), suggesting that plants could utilize both the weak light and the high light. Maximum net photosynthetic rate (Pn max), dark respiration rate (Rd), and maximum electron transfer rate (Jmax) increased under the shading treatment. There was significant difference between natural and shade treatment in net photosynthetic rate (Pn), stomatal conductance to CO2(gsc), intercellular CO2 concentration (Ci), and mesophyll conductance (gm). Pn and gm of different light regimes were sorted from the highest to the lowest as shading rate 78% > shading rate 50% > full light. gsc under shading rate 78% was higher than that under full light. Ci under shading rate 50% and 78% were lower than that under full light. Actual photochemical efficiency of PS2 (Fv'/Fm'), quantum yields of PS2 (ΦPS2), and electron transport rate (J) of P. bournei leaves were significantly higher under shading rate 78% than those under shading rate 50% and full light. In conclusion, P. bournei could increase Pn by increasing chlorophyll content, AQY, J, gsc, and gm under shade condition.

Effects of solar radiation on CH4 emission in paddy field

Decrease in solar radiation is one of the main components of climate change. Studies aimed at examining the effects of decreased solar radiation on CH4 emission and estimation of CH4 emission based on hyperspectral data in paddy fields are still scarce. A field simulation experiment was conducted to investigate the effects of shading intensity on CH4 emission in a paddy field and rice canopy hyperspectral properties. CH4 emission flux was estimated with rice canopy hyperspectral data. The shading intensities were set at three levels, i.e. control (CK, no shading), light shading (S1, 60% of shading rate), and heavy shading (S2, 84% of shading rate). The results showed that shading significantly reduced CH4 emission. However, CH4 emission under heavy shading (S2) was higher than that under light shading (S1). The reflectance of the near-infrared spectrum on rice canopy from the jointing stage to grain filling stage was in the sequence of CK>S2>S1. The spectral reflectance on rice canopy was significantly and positively correlated with CH4 flux in the near-infrared band (699-1349 nm), with a correlation coefficient of 0.64 (P<0.01). The six vegetation indices were significantly correlated with CH4 flux. The correlation coefficient between Ratio Vegetation Index (RVI) and CH4 flux was the largest, with R2=0.84 (P<0.01). The stepwise regression model with RVI, Normalized Difference Vegetation Index (NDVI), and 507 nm original reflectance (Ρ507) parameters was the best one (fitting model R2=0.86, prediction model R2=0.85) for estimating CH4 emission.

Visually Lossless Content and Motion Adaptive Shading in Games

We present a technique that adaptively adjusts the shading rate during rendering based on the scene content and motion. Our goal is to improve performance with no loss in perceived quality. We determine per-screen-tile shading rate by testing an error estimate against a perceptually-corrected just-noticeable difference threshold. Our design features an effective and efficient error estimate using spatial and frequency analysis of half and quarter rate shading. We also study the effect of motion in reducing perceived error, a consequence of display-persistence and/or motion blur effects. Our implementation uses the computed per-tile shading rate with variable rate shading (a recent GPU feature) to lower shading cost. We demonstrate the quality and performance of our technique on two high-end game engines and shipped games.

Effects of Different Shading Rates on the Photosynthesis and Corm Weight of Konjac Plant

To study the effects of shading level on the photosynthesis and corm weight of konjac plant, the chlorophyll fluorescence parameters, daily variation of relative electron transport rate (rETR), net photosynthetic rate (Pn), and corm weight of konjac plants under different treatments were measured and comparatively analyzed through covered cultivation of biennial seed corms with shade nets at different shading rates (0%, 50%, 70%, and 90%). The results showed that with the increase in shading rate, the maximum photochemical efficiency, potential activity, and non-photochemical quenching of photosystem Ⅱ (PSⅡ) of konjac leaves constantly increased, whereas the actual photosynthetic efficiency, rETR, and photochemical quenching of PSⅡ initially increased and then decreased. This result indicated that moderate shading could enhance the photosynthetic efficiency of konjac leaves. The daily variation of rETR in konjac plants under unshaded treatment showed a bimodal curve, whereas that under shaded treatment displayed a unimodal curve. The rETR of plants with 50% treatment and 70% treatment was gradually higher than that under unshaded treatment around noon. The moderate shading could increase the Pn of konjac leaves. The stomatal conductance and transpiration rate of the leaves under shaded treatment were significantly higher than those of the leaves under unshaded treatment. Shading could promote the growth of plants and increase corm weight. The comprehensive comparison shows that the konjac plants had strong photosynthetic capacity and high yield when the shading rate was 50%-70% for the area.&#x0D; &#x0D; *********&#x0D; In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue.&#x0D; *********

An experimental study on the improvement of indoor thermal environment of tents by shading in summer

Because of the simple structure and easy to carry, tents are widely used in military camps, rescue and disaster relief, site construction, tourism, nomadic people living and so on. However, the tent is very hot and humid in summer which seriously affects people’s rest and work. By the method of erecting a shading net on the top of the tent, the influence of solar radiation on the indoor thermal environment of tents in summer can be reduced. The indoor thermal environment of tents with different density shading nets was tested at a university campus of Tianjin, China. The experimental results showed that, comparing with the tent with no shading, the cooling effect of “six pins” net with shading rate of 96% is very good, the indoor temperature of the tent in summer can drop 8°C; while the indoor temperature of tent shaded by “three pins” net with shading rate of 75% can drop 5°C. The results also showed that: the internal surface temperature of the tent with shading nets can decrease about 12°C ∼17°C, the cooling effect is very obvious. The sun shading is conducive to improve the thermal environment of the tent.

Effects of Illumination Intensity on Ornamental Characteristics of &lt;i&gt;Neoregelia&lt;/i&gt;

Neoregelia has high ornamental value, which is tolerant to shade and drought. In addition, the daily maintenance and management of it is easy and convenient, so it is very popular with consumers. However, illumination intensity has great impact on its blade color. The four seasons in the south of Yangtze River are distinct, and cooling and shading in summer are contradictory, resulting in difficulty in production. This study introduced the morphological characteristics and growth habit of Neoregelia . Through a series of experiments in both plain and mountain sites, we confirmed that the optimum illumination intensity for most varieties of Neoregelia was 50~55 klx. During production procedure, 50% shading rate could ensure illumination intensity under 55 klx, but some green blade varieties need weaker illumination intensity. The shading rate should be kept under 70% to maintain regular blade color. 70 klx illumination intensity could burn the blade of Neoregelia . This study could provide guidance for production and daily management of Neoregelia .

Tile Pair-Based Adaptive Multi-Rate Stereo Shading.

This work proposes a new stereo shading architecture that enables adaptive shading rates and automatic shading reuse among triangles and between two views. The proposed pipeline presents several novel features. First, the present sort-middle/bin shading is extended to tile pair-based shading to rasterize and shade pixels at two views simultaneously. A new rasterization algorithm utilizing epipolar geometry is then proposed to schedule tile pairs and perform rasterization at stereo views efficiently. Second, this work presents an adaptive multi-rate shading framework to compute shading on pixels at different rates. A novel tile-based screen space cache and a new cache reuse shader are proposed to perform such multi-rate shading across triangles and views. The results show that the newly proposed method outperforms the standard sort-middle shading and the state-of-the-art multi-rate shading by achieving considerably lower shading cost and memory bandwidth.

Detection and Assessment of Partial Shading Scenarios on Photovoltaic Strings

There has been growing interest in using photovoltaic (PV) energy harvesting technology to reduce reliance on mineral-based energy. Partial shading scenarios (PSS) significantly affect the electrical characteristics of a PV generator. However, a few studies have devoted to the detection and assessment of the PSS. In this paper, shading rate and shading strength are used to characterize the PSS. A shading pattern detection algorithm is proposed to estimate the number of shaded modules in a PV string and distinguish the PSS from uniform irradiation scenarios. A multiple-output support vector regression is applied to estimate the shading strength. In addition, the maximum power point voltage of the applied PV generation system can be predicted from measured data. Simulation and experimental validation show the feasibility of the proposed method in the face of various environmental conditions. It could be used as a preliminary step toward automatic supervision and monitoring PV generation system.

Effects of shading on leaf physiology and morphology in the ‘Yinhong’ grape plants

Abstract Shading is a practical measure to reduce the heat stress to grape trees in the summer. However, inappropriate shading will cause the reduction in leaf photosynthesis and consequently the retardation of growth for the plants or the loss of fruit yield and quality for the mature grape trees. In this study we have used 1-year-old ‘YinHong’ grape plants growing under different levels of shading, ranging from full sunlight 0% to 80% reduction, to investigate their growth, physiological and biochemical responses. The results show that shading rate =45% did not significantly affect grape growth. Shading over 45% reduction of the full sunlight, the growth of the grape plants were started to be inhibited. In addition, soluble protein content, the activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD), chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate (Tr), PSII photochemical efficiency (Fv/Fm), PSII potential activity1(Fv/Fo) and photochemical quenching (qP) were decreased, whereas free proline, malondialdehyde (MDA) content, the non-photochemical quenching coefficient (qN) and the ratio of the palisade/spongy tissue were gradually increased. In particular, significant changes in plant growth, photosynthetic and the other physiological and biochemical characteristics were observed under a strong shading.

Optimization Design of a Multibusbar Structure: The Using of a Conductive Belt

An interconnect electrode called conductive belt was applied to modules instead of interconnection ribbons. The conductive belt has multiple wires and can achieve a multibusbar structure by forming ohmic contacts with the cell electrodes. The following problems were studied with innovative approaches to optimize the multibusbar modules: the shading rate and the contact resistance of the conductive belts, the relationship between the finger series resistance and the wire number, and the influence of the series resistance variation on the maximum power output. Furthermore, the wire number and diameter were optimized according to the following conditions: the cell sizes were full, half, and one-third, and the finger wet weights of a full cell were 80 mg, 40 mg, and 20 mg. The result showed that multibusbar and half-cell structures could achieve the maximum power output, the wire number was 16 and the wire diameter was 200 μm, and the finger wet weight was reduced to 20 mg. Finally, the reliability of the modules made with conductive belts was tested and was qualified according to International Electrotechnical Commission standards.

Identifikasi Kesesuaian Genotipe Kedelai untuk Tumpang Sari dengan Ubi Kayu

Intercropping is a modification of crop arrangements that can provide significant improvements in yields, with minimal labor investment. Increased productivity in soybean intercropping with cassava can be achieved through the use of suitable soybean genotypes for intercropping, as each genotype shows different responses to intercropping. The research aimed to identify the suitability of soybean genotypes for intercropping with cassava based on yield and land productivity assessed by the land equivalent ratio (LER). The research in 2016 was conducted at Kendalpayak Station Research, Malang, using a split plot design, repeated three times. The main plot is fifty-five soybean genotypes (50 promising lines and five control varieties, namely: Argopuro, Panderman, Dena 1, Dena 2, and Grobogan), and the sub plot is cropping systems (monoculture and intercropping). The results showed that intercropping of soybean with cassava caused soybean plants to experience shade stress, with shade rate of 62-90, 43-77, and 0-40% respectively for first, second and third-row positions. There are six soybean genotypes suitable for intercropping with cassava, Grob/Argom313-2, Grob/Pander395-3, Grob/Pander405-3, Grob/Pander428-1, Grob/Pander429-2, and Grob/IAC439-2, with an LER value of ≥1.8 which is a 10% selection limit to LER. Four combinations of them (Grob/Pander395-3, Grob/Pander405-3, Grob/Pander428-1, and Grob IAC439-2) provide an increase in cassava yields between 7.7-19.7% and reduction of soybean yields between 21.4-38.5%. While the two combinations other (Grob/Argom313-2 and Grob/Pander429-2) provide a reduction of cassava yields by 1.4 and 8.5% and reduction of soybean yield by 23.5 and 7.1%.

An experimental validation of the effect of partial shade on the I-V characteristic of PV panel

Solar panels are gaining importance as the main alternative source of energy in the current conditions of non-renewable energy depletion. Solar panels are increasingly used in large- and small-scale installations. Partial shade is one of the problems that are faced in terrestrial applications of solar photovoltaic. The partial shading reduces the power output of a solar PV panel. This paper presents an experimental study carried out to illustrate the influence of partial shading on the electrical characteristics of a solar PV panel. Three different cases of shading as one cell, one branch, and one horizontal line are studied. Results showed that the power loss occurred as 74.42, 79.54, and 98.97% for a 100% shading rate of one cell, one branch, and one horizontal line, respectively.

Outdoor study of partial shading effects on different PV modules technologies

Total or partial shading conditions have a significant impact rate on the capability of delivering energy, in addition to the on-site environmental condition which effects the PV module output production. Generally, the shading effect is caused by the PV generator inter-row configurations, cloudy perturbations, the buildings and trees. In this paper, an investigation study has been carried out by testing different PV module types (mono-crystalline, polycrystalline) under different shading rates. The obtained I-V characteristics have been treated through the Bishop model where the power losses occurred on the PV module output, have been evaluated. The measured and estimated I-V characteristic plots illustrated a good agreement and the used model provides an accurate power losses prediction caused by different shading effects, even in desert areas.

Effects of partial shading on energy and exergy efficiencies for photovoltaic panels

Photovoltaic (PV) technology becomes very popular with development of material science among the indispensable of solar energy in recent years. In this paper is investigated the electrical performance and thermodynamics analysis under the shading shapes and shading ratios of photovoltaics panels which have in 75 W power. The operating and electrical parameters of a photovoltaic panel are including cell temperature, overall heat loss coefficient, fill factor, etc. With this aim, an experimental set-up was constructed and serial experiments were done for different parameters such as shading ratio and positions. Three different cases of shading effects as cell, horizontal and vertical shading at different percentage. The results showed that the values of fill factor are also determined for the systems and effect of fill factor on the efficiencies is also evaluated. The shading makes important effect on energy and exergy efficiencies of the system and the most important effect is formed in case of horizontal shading. The maximum power loss was occurred at the shading rate 100% as 69.92% in cellular, 66.93% in vertical, 99.98% in horizontal shading.

Effects of shading in summer and autumn on physiological and biochemical characteristics of 'Huangjinya' in Shandong Province, China

In order to ensure the suitable shade model for 'Huangjinya' tea plant in Shandong Province, black or blue shading net at 55%, 70% or 85% shading rates was selected to recover tea garden in summer and autumn, then micro-climate of tea garden, leaf color, chlorophyll fluorescence parameters, growth status and biochemical composition of tea shoots were investigated.The results showed that compared with the control, light intensity and air temperature in tea garden, leaf temperature of tea plants in different shading treatments significantly decreased, while air humidity in tea garden increased. The contents of chlorophyll in the tea leaves were obviously increased with increasing the shading rate, which resulted in the leaf color becoming green. The yellowing characteristics and biochemical quality of 'Huangjinya' tea plants could be well kept in 55% shading treatments. In 70% shading treatments, 'Huangjinya' tea plants had better growth situation and higher yield with no photo-inhibition. Compared with the blue shading treatments, black shading treatments could obviously promote the growth of 'Huangjinya' tea plants, keep yellowing characteristics, and improve the quality. Therefore, the 70% black shading treatment (daily PAR values of 1.2-3.5 ten thousand lx) was appropriate for promoting the growth of 'Huangjinya' tea plants at the seedling stage. For mature tea plants, the 55% black shading treatment (daily PAR values of 1.8-5.5 ten thousand lx) could be used to keep the yellowing characteristics and to improve biochemical quality effectively, so as to give full play to its variety characteristics, to achieve goal of high quality and high yield.

Study on Characteristics of Light Transmission Device with Automatic Adjusting Brightness and Heat Flux

This study presents a light transmission device with automatic adjusting brightness and heat flux. This device uses bimetallic strip as an important component of automatic brightness in the device, using bimetallic strip when heated bending angle changes the nature of the implementation according to the intensity of solar radiation and the outdoor temperature through or the function of keep out sunshine, to achieve the purpose of increase or decrease into the interior of the sun’s radiation, reducing the glare and energy consumption of air conditioning in summer. The adjustment performance of the light transmission device was analyzed by setting up the experimental room and the contrast room. The influence of the angle between the sun’s light and the bottom of the experiment room and the length to width ratio of the room was analyzed. It can be seen from the experimental analysis, the light transmission device at noon sun illumination the strongest shading rate of 2.56% ~ 6.47%.

Aggregate G-Buffer Anti-Aliasing -Extended Version.

We present Aggregate G-Buffer Anti-Aliasing (AGAA), a new technique for efficient anti-aliased deferred rendering of complex geometry using modern graphics hardware. In geometrically complex situations where many surfaces intersect a pixel, current rendering systems shade each contributing surface at least once per pixel. As the sample density and geometric complexity increase, the shading cost becomes prohibitive for real-time rendering. Under deferred shading, so does the required framebuffer memory. Our goal is to make high per-pixel sampling rates practical for real-time applications by substantially reducing shading costs and per-pixel storage compared to traditional deferred shading. AGAA uses the rasterization pipeline to generate a compact, pre-filtered geometric representation inside each pixel. We shade this representation at a fixed rate, independent of geometric complexity. By decoupling shading rate from geometric sampling rate, the algorithm reduces the storage and bandwidth costs of a geometry buffer, and allows scaling to high visibility sampling rates for anti-aliasing. AGAA with two aggregates per-pixel generates results comparable to 32 × MSAA, but requires 54 percent less memory and is up to 2.6 × faster ( -30 percent memory and 1.7 × faster for 8 × MSAA).

Effect of rain shelter and shading on plantlets growth and antioxidant contents in strawberry

In the present experiment, a susceptible strawberry Benihoppe was employed to note the effect of rain shelter and shading on plantlets growth and antioxidant system. In the shading treatments, the temperature (1:00 pm) inside the greenhouse was reduced compared to the control. The plastic house covered with 60 and 70% shading nets could decrease the temperature by less than 1°C compared with 80 and 90% shading nets, which could decrease it by 1.2 and 1.3°C, respectively. Even in the cloudy dawn and dusk, shading net with 80% can maintain a light intensity of more than 10,000 lux and plantlets could grow healthy. The plantlets under shading environment grew longer than the control. The plantlets under 90% shading rate had the maximum height, i.e. 14.35% higher than the control. The anthracnose incidence and disease index were reduced under shade nets, while the average plantlet numbers per square metre increased. The maximum numbers were under those of 80 and 90% shading rate treatments. The disease incidence was minimum under 80% shading treatment. The shading treatment, altered the content of Chl and MDA, while SOD and POD activities, significantly in order to adapt to the low light environment. The 80% shading net was the most suitable shading measure.