To see the other types of publications on this topic, follow the link: Length of sunlight.
Journal articles on the topic 'Length of sunlight'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Length of sunlight.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Benedetti, Francesco, Cristina Colombo, Barbara Barbini, Euridice Campori, and Enrico Smeraldi. "Morning sunlight reduces length of hospitalization in bipolar depression." Journal of Affective Disorders 62, no. 3 (February 2001): 221–23. http://dx.doi.org/10.1016/s0165-0327(00)00149-x.
Full text
2
Lilabati, Laishram, and U. K. Sahoo. "Germination and Growth Behaviour of Seedlings of Emblica ofƒicinalis Gaertn under Different Light and Nutrient Regimes in Field Conditions." Science & Technology Journal 4, no. 2 (July 1, 2016): 98–104. http://dx.doi.org/10.22232/stj.2016.04.02.03.
Full textAbstract:
Emblica officinalis Gaertn. is an important non-timber forest product plant which is known in improving livelihood of the people of north-east India. This plant is widely used in the Indian system of medicines and believed to increase the body immunity against diseases. A trial was made to assess the initial growth performance of seedlings of E. officinalis under three light regimes viz. Open-100% ambient sunlight (FAL), partial-80% ambient sunlight (PAL) and deep shade-40% ambient sunlight (DAL) and four nutrient conditions (NPK, saw dust biochar, cowdung and untreated) during a 3-months period in the Department of Forestry Mizoram University, Mizoram India. After 12 weeks of exposure to different light regimes and nutrient conditions, initial growth parameters of the seedlings like number of leaves, shoot length, root length, biomass and vigour index measured in order to understand the best growth conditions for the plant. The results reveal that seed germination and other growth parameters were significantly (P<0.05) influenced by light regimes and nutrient treatments. The seedling height, number of leaves, shoot length, root length and biomass was significantly higher under FAL. All growth parameters including seed germination were poor under DAL.
3
Mo, Yan, Guangyong Li, Dan Wang, Jiandong Wang, Haidong Chai, and Xiuming Zou. "Mechanism of Sunlight Damage on Drip Tape by Pendant Droplets in Mulched Drip Irrigation." Transactions of the ASABE 61, no. 6 (2018): 1969–75. http://dx.doi.org/10.13031/trans.12979.
Full textAbstract:
Abstract. Drip irrigation under mulch has been applied in China for nearly 20 years, but sunlight damage from the lens effect through droplets beneath clear plastic mulch is always a problem that cannot be ignored. Droplet volume and mulch wettability affect the geometric parameters of the pendant droplets. Changes in geometric parameters were experimentally investigated by analyzing side-view images of droplets. Models were built to predict droplet focal length and light-gathering power based on the geometric parameters. A comparison between numerical and optical experimental results suggested that the focal length model was accurate and reliable. The effective incident area of the parallel light proposed in this study could also be used to represent the light-gathering power, which had a relationship with the drip tape burning rate. The increase in wettability of the clear mulch considerably increased the focal length of the pendant droplets, expanded the focal length range, enhanced the light-gathering power, and thus increased the risk of drip tape burning. In practice, pendant droplets with a wetting radius of 3 to 5 mm, with corresponding focal lengths of 5 to 12 mm, have a high probability of emergence. Therefore, the distance between the mulch and drip tape should be beyond this focal length range to reduce the risk of drip tape burning by pendant droplets. In addition, filming the mulch surface with hydrophobic materials to increase the contact angles of droplets can also protect the drip tape from sunlight damage. Keywords: Drip irrigation under mulch, Drip tape burning, Effective incident area of parallel light, Focal length, Pendant droplet.
4
Senthilnathan, Anoja, D. M. S. N. Dissanayake, G. T. D. Chandrakumara, M. M. M. G. P. G. Mantilaka, R. M. G. Rajapakse, H. M. T. G. A. Pitawala, and K. M. Nalin de Silva. "Akaganeite nanorices deposited muscovite mica surfaces as sunlight active green photocatalyst." Royal Society Open Science 6, no. 3 (March 2019): 182212. http://dx.doi.org/10.1098/rsos.182212.
Full textAbstract:
Thin films of akaganeite [FeO(OH)] nanorices deposited muscovite mica (ANPM) surfaces are synthesized using the facile urea assisted controlled self-assembly technique. The synthesized materials are characterized using scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy, atomic force microscopy, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). The prepared nanorices on mica surfaces show average particle length and width of 200 and 50 nm, respectively. Synthesized material acts as an efficient photocatalyst under UV and sunlight conditions as demonstrated by the degradation of standard methylene blue (MB) solution. The MB degradation efficiencies of the catalyst under exposure to 180 min sunlight and UV are 89% and 87.5%, respectively, which shows that the catalyst is more highly active under sunlight than under UV light. Therefore, the synthesized material is a potential green photocatalyst in efficient treatment of industrial dye effluents under direct sunlight.
5
Schluckebier, J. G., and C. A. Martin. "Effects of Above-Ground Pot-in-Pot (PIP) Placement and Humic Acid Extract on Growth of Crape Myrtle." Journal of Environmental Horticulture 15, no. 1 (March 1, 1997): 41–44. http://dx.doi.org/10.24266/0738-2898-15.1.41.
Full textAbstract:
Abstract Rooted cuttings of crape myrtle (Lagerstroemia indica L. × L. fauriei Koehne ‘Muskogee’) were potted into 3.8 liter (1 gal) black polyethylene containers and subjected for two months to one of three above-ground shielding treatments; containers placed pot-in-pot (PIP) for two months, containers exposed to direct sunlight for two months, or containers placed PIP for one month and then exposed to sunlight for one month (PIP/exposed). Mean daily maximum temperatures in rooting substrate of containers exposed to sunlight were as much as 16C (29F) higher than PIP containers. Plants in containers exposed to sunlight for two months had less total root and shoot length and higher concentrations of leaf nitrogen compared with the other two treatments. Plants were next transplanted into 27-liter (7-gal) polybags filled with a landscape substrate and fertigated with a humic acid extract at 0, 50, 150, or 300 μL/L for two additional months. The change in shoot and root length of plants previously placed PIP for two months responded in quadratic fashion to increased humic acid extract concentration levels; the most response occurred at about 50 μL/L while the highest concentrations inhibited post-transplant growth. Growth inhibition caused by heat stress as a result of exposure of container walls to insolation was still evident two months after transplanting.
6
Hawley, A. L., and H. J. Fallowfield. "Pond walls: inclined planes to improve pathogen removal in pond systems for wastewater treatment?" Water Science and Technology 78, no. 1 (June 14, 2018): 31–36. http://dx.doi.org/10.2166/wst.2018.269.
Full textAbstract:
Abstract Attenuation of sunlight in wastewater treatment ponds reduces the depth of the water exposed to disinfecting irradiances. Shallow pond depth with paddlewheel rotation increases exposure of pathogens to sunlight in high rate algal ponds. Generation of thin films, using pond walls as inclined planes, may increase inactivation of pathogens by increasing sunlight exposure. The performance of a laboratory based model system incorporating an inclined plane (IP) was evaluated. F-RNA bacteriophage, in tap water or wastewater, was exposed to sunlight only on the IP with the bulk water incubated in the dark. MS2 inactivation was significantly higher when the IP was present (P < 0.05) with a 63% increase observed. Prolonged exposure increased MS2 die-off irrespective of IP presence. Versatility of the IP was also demonstrated with faster inactivation observed in both optically clear tap water and wastewaters. IPs of different surface areas produced similar inactivation rates when operated at similar hydraulic loading rates regardless of slope length.
7
Marler, Thomas E., Bruce Schaffer, and Jonathan H. Crane. "Developmental Light Level Affects Growth, Morphology, and Leaf Physiology of Young Carambola Trees." Journal of the American Society for Horticultural Science 119, no. 4 (July 1994): 711–18. http://dx.doi.org/10.21273/jashs.119.4.711.
Full textAbstract:
Growth and leaf physiology responses of container-grown `Arkin' carambola (Averrhoa carambola L.) trees to long-term exposure of ≈25%, ≈50%, or 100% sunlight were studied in four experiments in Guam and Florida. Shading increased rachis length and leaflet area, and decreased leaflet thickness. Shaded trees also had a more horizontal branch orientation. Shading reduced dark respiration (Rd) and light compensation and saturation points but increased chlorophyll concentration and N-use efficiency. Light-saturated net CO2 assimilation (A) was not affected by developmental light level. Trees in full sun had smaller total leaf area, canopy diameter, and shoot: root ratio and exhibited leaflet movement to avoid direct solar radiation. Also, trees grown in 100% sunlight had a more vertical branch orientation and greater stomatal density than shaded trees. The ratio of variable to maximum fluorescence (Fv/Fm) declined during midday in 100% sunlight trees. This pattern was accompanied by a midday suppression of A in 100% sunlight-grown trees in Guam. `Arkin' carambola trees exposed to ≈25%, ≈50%, or 100% sunlight for up to 39 weeks exhibited physiological and morphological adaptations that resulted in similar growth. These results indicate that carambola efficiently adapts to different developmental light intensities.
8
Mizell, R. F., D. E. Schiffhauer, and J. L. Taylor. "MORTALITY OF TETRANYCHUS URTICAE KOCH (ACARI: TETRANYCHIDAE) FROM ABAMECTIN RESIDUES: EFFECTS OF HOST PLANT, LIGHT, AND SURFACTANTS." Journal of Entomological Science 21, no. 4 (October 1, 1986): 329–37. http://dx.doi.org/10.18474/0749-8004-21.4.329.
Full textAbstract:
Residues of abamectin (avermectin, Avid), 15 ppm; abamectin + Leaf Act 80, 15 + 25 ppm; abamectin + Sunspray oil, 15 + 25 ppm, and a water control were evaluated for length of control of twospotted spider mite, Tetranychus urticae Koch, on 3 host species: azalea, Rhododendron × ‘Red Ruffle’; lima bean, Phaseolus limensis var. limenus L. H. Bailey cv. ‘Henderson’ bush; and peach, Prunus persica L. Batsch cv. ‘Nemaguard’; and under sunlight and fluorescent light regimes. Abamectin alone or in combination with the surfactants, 21 days post treatment, resulted in 42.6 – 91.8% and 88 – 93% mite mortality under sunlight and fluorescent light, respectively. No treatments on azalea or peach under sunlight caused > 37% mortality. Treatments caused similar mite mortality 1 day posttreatment under fluorescent light, but after day 1 treatments on peach caused < 62 % mortality while treatments on azalea caused < 46% mortality. The addition of oil increased mite mortality significantly on beans under sunlight at 14 days. At 21 days both Leaf Act 80 and oil increased mite mortality on bean compared to abamectin alone.
9
Hou, Lin Rui, and Chang Zhou Yuan. "Facile Fabrication of Taper-Like BiVO4 Nanorods with High Photocatalytic Property under Sunlight Irradiation." Advanced Materials Research 96 (January 2010): 87–92. http://dx.doi.org/10.4028/www.scientific.net/amr.96.87.
Full textAbstract:
We report the synthesis of the taper-like BiVO4 nanorods by employing a solid-state grinding synthetic strategy. The X-ray diffraction (XRD) indicates that the as-prepared BiVO4 nanorods were crystallized in a monoclinic system. The diameter and length of taper-like nanorods are confirmed by the scanning electron microscopy (SEM) technology. The diameter and length of the taper-like nanorods are 100 nm and 1 μm, respectively. And the photocatalytic activity of the taper-like BiVO4 nanorods was evaluated by measuring the degradation of methylene blue (MB) in water under sunlight irradiation. MB was degraded nearly to nothing under sunlight irradiation for 120 min at room temperature in air. These results indicate the as-prepared product is a good sun-driven photocatalyst. In addition, the degradation mechanism of methylene blue over BiVO4 nanorods was tentatively investigated.
10
Cornea-Cipcigan, Mihaiela, Doru Pamfil, Cristian Radu Sisea, and Rodica Mărgăoan. "Gibberellic Acid Can Improve Seed Germination and Ornamental Quality of Selected Cyclamen Species Grown Under Short and Long Days." Agronomy 10, no. 4 (April 3, 2020): 516. http://dx.doi.org/10.3390/agronomy10040516.
Full textAbstract:
Cyclamen species (swinebread spp.) are perennial herbaceous plants which belong to the Primulaceae family, widely used as medicinal or ornamental plants. Currently, gibberellic acid (GA3), an environmentally friendly bioregulator is widely used to enhance the productivity and phenotypic characteristics of multiple ornamental crops. A dual experiment was conducted to evaluate the influence of gibberellic acid (50, 100 or 150 mg/L), on germination earliness of seeds, along with growth and ornamental quality of selected Cyclamen species. Additionally, a greenhouse experiment with long and short sunlight photoperiod was conducted to evaluate its importance in the development of Cyclamen plants. Our results indicated that under short sunlight exposure, seeds germinated earlier than those kept in long sunlight photoperiod. Plants treated with foliar applications of GA3 exhibited higher plant height, leaf area, number of leaves, root length and tuber development. Significant differences were found in germination percentage (GP), mean germination time (MGT) and seedling vigor index (SVI), within different GA3 supplementation and greenhouse sunlight intensity (short and long days). In conclusion, our study suggests that seedling vigor and ornamental quality can be increased by GA3 application, an economic strategy for enhancing germination and growth of selected Cyclamen species.
11
Santos, Rafaelle Ferreira dos, Rogéria Lucio de Oliveira, Marina Gallottini, Rubens Caliento, and Dmitry José de Santana Sarmento. "Prevalence of and Factors Associated with Actinic Cheilitis in Extractive Mining Workers." Brazilian Dental Journal 29, no. 2 (March 2018): 214–21. http://dx.doi.org/10.1590/0103-6440201801605.
Full textAbstract:
Abstract The objective of the present study was to determine the prevalence of actinic cheilitis among extractive mining workers and factors associated with the condition, especially the relationship between clinical appearance and the length of occupational exposure to sunlight. A cross-sectional study was performed in Dona Inês, Paraíba, Brazil between 2014 and 2015. A clinical examination, clinical photography and a questionnaire were applied to 201 extractive mining workers. The T-student’s, ANOVA one-way, Fisher’s exact and Pearson chi-squared tests were performed and the significance level was set at 5%. A high prevalence of actinic cheilitis was observed (38.8%). Length of occupational exposure to sunlight in months (169.63±112.68, p=0.002) was associated with actinic cheilitis. Most workers were Caucasian (p<0.001) and aged 37.41±12.15 years (p=0.004). The time of occupational exposure to sunlight was significant in relation to the following clinical features: atrophy (225.75±97.31; p=0.024); blurred demarcation between the vermilion border of the lip and the skin (186.68±113.15; p=0.032); vertical fissures (210.09±123.07; p=0.046); white and red spotting (199.51±91.80; p=0.004); hard consistency of the lip (225.81±122.34; p=0.012). A high prevalence of actinic cheilitis was found. Age and ethnicity were associated with the presence of AC. Severe clinical presentations of actinic cheilitis were found among participants who had worked for at least 185 months (approximately 15 years) exposed to the sun.
12
Wang, Wei Liang, Chuan Xi Yang, Feng Zhang, Ping Li, and Guan Wei Cui. "Remarkable Sunlight Photocatalytic Activity due to Synergetic Effect of ZnO with Cu." Key Engineering Materials 727 (January 2017): 388–94. http://dx.doi.org/10.4028/www.scientific.net/kem.727.388.
Full textAbstract:
The ZnO nanorod was synthesized by the hydrothermal method, and Cu/ZnO nanorod was synthesized by modifying the prepared ZnO nanorod. The TEM was used to characterize the morphology and microstructure for ZnO and Cu/ZnO nanorod. The length of nanorod ZnO was about 700-800 nm, and the diameter about 40-50 nm. There was no change of ZnO in length and diameter when doped with Cu. The degradation of methylene blue (MB) in an aqueous solution under sunlight irradiation was carried out to evaluate the photocatalytic activity. The Cu/ZnO nanorod shows significantly higher photocatalytic activity (99.91%) than ZnO nanorod (89.66%) under sunlight irradiation. The degradation of MB accords with pseudo-first order kinetics, and the appear rate constants kapp of 7% Cu/ZnO nanorod was about 3 times higher than ZnO nanorod. The synergetic effect between ZnO nanorod and Cu on the photocatalytic degradation of MB exists clearly for all the nanorods, and the optimum synergetic effect was found at a weight ratio of 7 wt % (Cu/ZnO). It hoped our works could provide valuable information on the synthesis and application of ZnO-based heterogeneous photocatalysis.
13
Costa, Larissa Corrêa do Bomfim, José Eduardo Brasil Pereira Pinto, Evaristo Mauro de Castro, Eduardo Alves, Suzan Kelly Vilela Bertolucci, and Louise Ferreira Rosal. "Effects of coloured shade netting on the vegetative development and leaf structure of Ocimum selloi." Bragantia 69, no. 2 (2010): 349–59. http://dx.doi.org/10.1590/s0006-87052010000200012.
Full textAbstract:
The objective of this work was to investigate the effects of shading on the growth and development of the medicinal plant Ocimum selloi after 90 days. Seedlings were maintained under three different light treatments, namely, full sunlight vs coloured shade treatments provided by red and blue ChromatiNet® 50% coloured netting. After 90 days of cultivation, height, stem diameter, petiole length, total leaf area (TLA), specific leaf area (SLA), leaf area ratio (LAR) and leaf weight ratio (LWR) of each plant hare measured. Microscopic examination of leaf sections were conducted in order to determine the leaf blade thicknesses, together with the size and density of the stomata, the number and area of chloroplasts, and chloroplast starch grains present in the palisade parenchyma cells. Although coloured shade-grown plants were taller in comparison with those grown in full sunlight, total dry biomass together with root, stem and leaf tissue biomasses were lower. Plants exhibited phenotypic plasticity, as demonstrated by the different TLA, SLA, LAR and LWR values that were recorded under the various light treatments. Stomatal density and leaf thickness was increased in plants maintained in full sunlight owing to the expansion of the abaxial epidermis and the spongy parenchyma. Chloroplasts were more numerous and larger in plants grown under shading, whilst the accumulation of chloroplastic starch grains was greater in plants grown under red shading or in full sunlight.
14
Gramig, Greta G., and David E. Stoltenberg. "Adaptive Responses of Field-Grown Common Lambsquarters (Chenopodium album) to Variable Light Quality and Quantity Environments." Weed Science 57, no. 3 (June 2009): 271–80. http://dx.doi.org/10.1614/ws-08-120.1.
Full textAbstract:
Field experiments were conducted to determine whether exposure to reduced red : far-red light ratios (R : FR) typical of crop–weed environments was associated with adaptive changes in morphology, productivity, and fecundity of common lambsquarters. Plants were grown in reduced or ambient R : FR environments (both in full sunlight) until initiation of flowering, after which plants were grown in full sunlight or partial shade. At initiation of flowering, plants that had been exposed to reduced R : FR exhibited greater specific leaf area, stem elongation, main stem leaf area, specific stem length, and main stem mass compared with plants exposed to ambient R : FR. However, biomass allocation to stems, leaves, and roots did not differ between vegetative-stage R : FR treatments. At the end of flowering, morphology and productivity of plants exposed to partial shade did not differ between vegetative-stage R : FR treatments. In contrast, plants exposed to full sunlight during flowering after exposure to reduced R : FR during the vegetative stage had less total plant mass, less total leaf area, greater stem elongation, greater specific stem length, and a greater ratio of main stem to total stem mass compared with plants exposed to ambient R : FR during the vegetative stage. At physiological maturity, plants exposed to reduced R : FR during the vegetative stage and to partial shade during the reproductive stage had less total seed mass and fewer seeds compared with plants exposed to ambient R : FR during the vegetative stage and to partial shade during the reproductive stage. Fecundity of plants exposed to full sunlight during the reproductive stage did not differ between vegetative-stage R : FR treatments. These results indicate that exposure of common lambsquarters to reduced R : FR during the vegetative stage was maladaptive at later stages of growth in competitive environments, and suggest that interactions of light quality and quantity are important determinants of common lambsquarters fecundity.
15
Omar, Fatin Saiha, Huang Nay Ming, Syed Muhamad Hafiz, and Lim Hong Ngee. "Microwave Synthesis of Zinc Oxide/Reduced Graphene Oxide Hybrid for Adsorption-Photocatalysis Application." International Journal of Photoenergy 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/176835.
Full textAbstract:
This work reports on synthesis of zinc oxide/reduced graphene oxide (ZnO/rGO) nanocomposites in the presence of diethylenetriamine (DETA) via a facile microwave method. The X-ray diffraction (XRD) patterns of the nanocomposites correspond to the ZnO hexagonal phase wurtzite structure. The high-resolution transmission electron microscopy (HRTEM) images revealed that the ZnO nanorods, with an average length : diameter ratio of 10, were successfully deposited on the rGO sheets. Under the irradiation of sunlight, the nanocomposites showed enhanced adsorption-photocatalysis by more than twofold and photocurrent response by sixfold compared to the ZnO. The excellent photoactivity performance of the nanocomposites is contributed by smaller ZnO nanorod and the presence of rGO that acts as a photosensitizer by transferring electrons to the conduction band of ZnO within the nanocomposite during sunlight illumination.
16
Lee, Gyeongjun, Jiyong Kim, Sungchul Kim, and Jungho Kim. "Effect of the Incoherent Encapsulation Layer and Oblique Sunlight Incidence on the Optical and Current-Voltage Characteristics of Surface-Textured Cu(In,Ga)Se2 Solar Cells Based on the Angle-Dependent Equispaced Thickness Averaging Method." Applied Sciences 11, no. 5 (February 27, 2021): 2121. http://dx.doi.org/10.3390/app11052121.
Full textAbstract:
In general, the optical and electrical characteristics of Cu(In,Ga)Se2 (CIGS) solar cells have been studied under the condition that sunlight is normally incident from the air to the CIGS solar cell having no thick front encapsulation layers. To obtain the calculation results in a realistic module application, we calculate the optical and current–voltage (J–V) characteristics of surface-textured CIGS solar cells by simultaneously considering the thick front encapsulation layers and oblique sunlight incidence. Using the proposed angle-dependent equispaced thickness averaging method (ADETAM), we incoherently model two successive front encapsulation layers of a cover glass layer and an ethylene vinyl acetate (EVA) layer, whose respective thicknesses are greater than the coherence length of sunlight (~0.6 μm). The angular dependences of reflectance spectrum and J–V curves are calculated and compared in a surface-textured CIGS solar cell with and without the inclusion of the two front encapsulation layers. We show that the optical absorption improvement of the surface-textured CIGS solar cell over the planar CIGS solar cell can be over-predicted when the thick front encapsulation layers are not considered in the optical modeling.
17
Qiu, Fanglv, Zi Wang, Hongjun Chen, Yue Ma, Hang Wu, Lu Yan, Lizhai Pei, and Chuangang Fan. "Sodium Dodecyl Benzene Sulfonate-assisted Synthesis and Natural Sunlight Photocatalytic Activity of La Bismuthate Nanorods." Current Nanoscience 16, no. 5 (October 5, 2020): 805–15. http://dx.doi.org/10.2174/1573413715666191212153902.
Full textAbstract:
Background: Removal of the organic pollutants using the photo-catalysts by the photocatalytic treatment process under natural sunlight irradiation has attracted great attention owing to the complete destruction of the organic pollutants. The La bismuthate nanorods possess good photocatalytic performance for the removal of the methylene orange (MO) under the sunlight irradiation. Objective: The aim is to synthesize La bismuthate nanorods by hydrothermal method and research the photocatalytic performance of the La bismuthate nanorods for MO degradation under sunlight irradiation. Methods: La bismuthate nanorods have been synthesized by a simple sodium dodecyl benzene sulfonate (SDBS)-assisted hydrothermal method using sodium bismuthate and La acetate as the starting materials. The obtained La bismuthate products were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy and solid UV-vis diffuse reflectance spectrum. Results: With different SDBS concentration, hydrothermal temperature and reaction time, different morphologies of the La bismuthate products were obtained. XRD analysis shows that the La bismuthate nanorods obtained from 180°C for 24 h with 5wt.% SDBS are composed of orthorhombic La1.08Bi0.92O3.03 phase. Electron microscopy observations show that the La bismuthate nanorods with flat tips have the length of longer than 10 μm and diameter of about 20-100 nm, respectively. The morphology and structure of the products are closely related to the SDBS concentration, hydrothermal temperature and reaction time. Solid UV-vis diffuse reflectance spectrum shows that the band gap of the La bismuthate nanorods is 2.37 eV. The La bismuthate nanorods show good photocatalytic performance for the degradation of MO under the sunlight irradiation. MO solution with the concentration of 10 mg.L-1 can be totally removed by 10 mg La bismuthate nanorods in 10 mL MO aqueous solution under sunlight irradiation for 6 h. Conclusion: The photocatalytic performance for the removal of MO is dependent on the sunlight irradiation time and dosage of the La bismuthate nanorods. The La bismuthate nanorods exhibit great potential for the removal of organic pollutants.
18
Chouchene, Bilel, Tahar Ben Chaabane, Lavinia Balan, Emilien Girot, Kevin Mozet, Ghouti Medjahdi, and Raphaël Schneider. "High performance Ce-doped ZnO nanorods for sunlight-driven photocatalysis." Beilstein Journal of Nanotechnology 7 (September 26, 2016): 1338–49. http://dx.doi.org/10.3762/bjnano.7.125.
Full textAbstract:
Ce-doped ZnO (ZnO:Ce) nanorods have been prepared through a solvothermal method and the effects of Ce-doping on the structural, optical and electronic properties of ZnO rods were studied. ZnO:Ce rods were characterized by XRD, SEM, TEM, XPS, BET, DRS and Raman spectroscopy. 5% Ce-doped ZnO rods with an average length of 130 nm and a diameter of 23 nm exhibit the highest photocatalytic activity for the degradation of the Orange II dye under solar light irradiation. The high photocatalytic activity is ascribed to the substantially enhanced light absorption in the visible region, to the high surface area of ZnO:Ce rods and to the effective electron–hole pair separation originating from Ce doping. The influence of various experimental parameters like the pH, the presence of salts and of organic compounds was investigated and no marked detrimental effect on the photocatalytic activity was observed. Finally, recyclability experiments demonstrate that ZnO:Ce rods are a stable solar-light photocatalyst.
19
Yue, Chunlei, Jie Chang, Kuihong Wang, and Yinmei Zhu. "Response of clonal growth in Phyllostachys praecox f. prevernalis to changing light intensity." Australian Journal of Botany 52, no. 2 (2004): 171. http://dx.doi.org/10.1071/bt02028.
Full textAbstract:
The morphological plasticity and biomass allocation pattern of clones of Phyllostachys praecox f. prevernalis were studied at four light intensities of 100, 70, 50 and 30% of sunlight. The results showed that ramet number and total biomass of clones were positively linearly correlated with light intensity. Under different light intensities, total rhizome length of clones and length of spacers were significantly different, indicating that rhizome and spacer both had considerable morphological plasticity. Internode length and branching angle did not differ significantly among different treatments. Under the lowest light intensity, the clone invested more biomass to aerial shoot production. The adaptation strategy of clone in P. praecox f. prevernalis for light is also discussed.
20
Wullandari, Putri, Arif Rahman Hakim, and Widiarto Sarwono. "Performance Test of Solar-Powered Ice Maker: Case Study in South Lampung." E3S Web of Conferences 43 (2018): 01018. http://dx.doi.org/10.1051/e3sconf/20184301018.
Full textAbstract:
The performance test of solar powered ice maker is being held at the fish auction spot of Kramat, South Lampung for 6 hours. The spesification of ice maker are: having the production capacity of 105 – 120 kg/ day, producing flakes ice with 2 x 3 x 3 mm dimension. The spesification of solar panel are: having maximum power of 200 W, 1,32 m length, 0,992 m width, and 1,3094 m2 area. In this test, we used 9 solar panel with the total area of 11,7846 m2. During the performance test, the intensity of sunlight, battery voltage, battery capacity, power input from solar panel, battery discharge current, maximum power consumption of ice maker, and total ice production are being measured. The sunlight-intensity value (lumen / m2) and the power input of the solar panel (watts) was plotted into a graph. Once the graph is created then add the trendline and create the equation. In a sunny-yet-cloudy weather conditions (at 24-33°C temperature and 65-95% humidity) in South Lampung, the relationship between the sunlight intensity with the power input of the solar panel is linear with the equation y = 0,008x + 143.6. Where the maximum intensity of sunlight is 121600 lm / m2 with the maximum power input of the solar panel (9 x 200Wp) is 1253 W. Total ice production for 6 hours is 28.42 kg or 4.74 kg per hour. This production resulted from a 760 W ice maker with a starting current of 4.6 A with a total power of 3.94 kWh.
21
Kashimada, Koji, Naoyuki Kamiko, Kazuo Yamamoto, and Shinichiro Ohgaki. "Assessment of photoreactivation following ultraviolet light disinfection." Water Science and Technology 33, no. 10-11 (May 1, 1996): 261–69. http://dx.doi.org/10.2166/wst.1996.0683.
Full textAbstract:
Photoreactivation of microorganisms following UV disinfection is one of the research topics of interest in assessing the performance of UV disinfection, because there is little consensus on how the visible light intensity relates to the photoreactivation rate and the maximum survival in wastewater treatment processes. Apparent photoreactivation by a fluorescent lamp was observed in case of indicator bacteria (heterotrophic bacteria, coliform bacteria, fecal coliforms) in raw sewage, but not E. coli B and E. coli K12 A/λ(F+). Inactivation of fecal coliform was observed simultaneously during photoreactivation process by sunlight. Dose rate at 360 nm wave length as visible light intensity showed that it was a useful indicator for assessing the photoreactivation rate and the maximum survival when photoreactivation took place by both fluorescent lamp and sunlight. The model for photoreactivation was developed. The photoreactivation rate increased with increasing visible light intensity at 360 nm. However, the maximum survival value may not be affected by visible light intensity.
22
Beghin, Laurent, Jérémy Vanhelst, Elodie Drumez, Jairo Migueles, Yannis Manios, Luis A. Moreno, Stefaan De Henauw, and Frederic Gottrand. "Influence of meteorological conditions on physical activity in adolescents." Journal of Epidemiology and Community Health 74, no. 4 (January 15, 2020): 395–400. http://dx.doi.org/10.1136/jech-2019-212459.
Full textAbstract:
BackgroundIt has been shown that meteorological conditions and season affect physical activity (PA) during adolescence. Today, meteorological conditions have never been combined to study their influence on PA level in a single sample of a large adolescent multicountries population. The aim of this study was to explore the influence of meteorological conditions on PA in adolescents from several European countries.MethodsThe study included 2024 healthy adolescents aged 12.5–17.4 years who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional study. Participants wore a uniaxial accelerometer for 7 consecutive days to measure total PA and moderate to vigorous physical activity (MVPA) in a one-off measurement manner. Comparison of PA according to meteorological conditions was done using linear mixed models.ResultsThe highest difference of MVPA was observed in boys on free days when comparing the best meteorological conditions versus the worse (ie, +39% with highest temperature, +29% without rainfall, +39% with highest sunlight duration and +21% with highest length of day) and in girls on free days (ie, +26% with highest sunlight duration). This increase in MVPA contributed to a simultaneous increase in total PA when considering the same meteorological condition parameters.ConclusionsMeteorological conditions act as a determinant of PA differentially between boys and girls. PA and MVPA in boys are mainly modified by meteorological conditions on free days whereas PA and MVPA in girls are modified by sunlight duration.
23
Liu, Bo, Qingqing Liu, Stefani Daryanto, Xiangqing Ma, Si Guo, Lixin Wang, and Zhengning Wang. "Seedling emergence and early growth of Chinese fir under different light levels and seed positions: implications for natural regeneration." Canadian Journal of Forest Research 48, no. 9 (September 2018): 1034–41. http://dx.doi.org/10.1139/cjfr-2017-0412.
Full textAbstract:
Chinese fir, Cunninghamia lanceolata (Lamb.) Hook. (Taxodiaceae), is an evergreen conifer primarily distributed in southern China. This species exhibits very poor natural regeneration, possibly due to low light and a thick litter layer. To improve the understanding of the natural regeneration capacity of Chinese fir, in this study, we conducted a shade house experiment to determine the optimum light requirements and seed positions for seedling emergence and early growth. The experiment involved five light levels (100%, 60%, 40%, 15%, 5% of full sunlight) and four seed positions (1 cm beneath the soil surface without litter, on the soil surface without soil–seed contact, on the soil surface and covered with litter, and 1 cm beneath the soil surface and covered with litter). Seedling emergence was highest at 5%–15% sunlight, whereas seedling height, root length, root mass, stem mass, leaf mass, and total mass were highest at 60% sunlight. For each light level, seed position significantly affected emergence and growth. The above-litter position inhibited seedling emergence and survival, while the below-litter position favored seedling emergence and early growth, particularly under high light levels. Based on these results, to enhance natural regeneration of Chinese fir, we recommend periodical thinning to increase light into the understory after successful seedling emergence. We also recommend sowing seeds deeper into the litter to improve soil contact and moisture conditions.
24
Mao, Qianjun, Liya Zhang, and Hongjun Wu. "Study on Concentrating Characteristics of a Solar Parabolic Dish Concentrator within High Radiation Flux." International Journal of Photoenergy 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/787280.
Full textAbstract:
Concentrating characteristics of the sunlight have an important effect on the optical-thermal conversion efficiency of solar concentrator and the application of the receiver. In this paper, radiation flux in the focal plane and the receiver with three focal lengths has been investigated based on Monte Carlo ray-tracing method. At the same time, based on the equal area-height and equal area-diameter methods to design four different shape receivers and numerical simulation of radiation flux distribution characteristics have also been investigated. The results show that the radiation flux in the focal plane increases with decreasing of the focal length and the diameter of the light spot increases with increasing of the focal length. The function of the position with a maximum of radiation flux has been obtained according to the numerical results. The results also show that the radiation flux distribution of cylindrical receiver has the best performance in all four receivers. The results can provide a reference for future design and application of concentrating solar power.
25
TURCOTTE, GILLES, and ANDRÉ GOSSELIN. "INFLUENCE DU MODE DE DISTRIBUTION D’UN ÉCLAIRAGE D’APPOINT (HPS) ET DE LA PHOTOPÉRIODE SUR LA CROISSANCE ET LES RENDEMENTS DU CONCOMBRE DE SERRE." Canadian Journal of Plant Science 68, no. 2 (April 1, 1988): 535–42. http://dx.doi.org/10.4141/cjps88-065.
Full textAbstract:
Eight light treatments were compared to determine the distribution and duration of supplementary lighting (HPS) that are best suited for the production of cucumber (Cucumis sativus L.) in winter. Seven groups of plants were exposed to supplementary lighting in two ways: with day length prolonged without interruption or with nights interrupted, producing photoperiods of 14, 16, 18, or 20 h. A control group was exposed only to sunlight. For a given duration of lighting, the type of light distribution affected neither the vegetative growth nor the early yield of the greenhouse cucumber. Plants exposed to long day lengths showed the best rate of growth and the highest yields: 20 h > 18 h > 16 h or 14 h > control.Key words: Cucumber, supplementary lighting (HPS), photoperiod, greenhouse, Cucumis sativus L.
26
Nugrahani, Elita Fidiya, Reza Arraffi Birahmatika, Epri Wahyu Pratiwi, and Sekartedjo K. "Design of Solar Transmission System using Fiber Optic for Indoor Lighting." KnE Energy 2, no. 2 (December 1, 2015): 59. http://dx.doi.org/10.18502/ken.v2i2.358.
Full textAbstract:
<p>Transmission of fiber solar lighting system is a lighting system using sunlight as a source. The system consists of two main components, there are: solar collectors and optical fiber. Solar collector is used to collect and focus sunlight into the focal point. Sunlight that received by collector is transmitted by optical fiber into the room, primarily through efficiency of the collector system. In this final project, we designed the transmission systems via optical fiber for lighting on the Photonics Laboratory ITS. Transmission of solar lighting systems used parabolic collector as a major collector and end glow plastic optical fiber as the transmission with length of 50m. There are four types of collector systems were designed, i.e. parabolic, parabolic with flat mirrors, parabolic with pyramid and parabolic with a cone. Characterization system consists of measuring reflectance values, the output intensity of the optical fiber, and the intensity light distribution in the room. The results of measurements of the reflectance (R) collector surface with paint gray and silver are 0.225 and 0.475, respectively. In the measurement light output intensity of the optical fiber with variation types of collector systems, it is obtained that the highest value from the combination of parabolic collector with a cone. Distribution of light output from the optical fiber in the room was also calculated and measured. </p><p><strong>Keywords</strong>: collector; optical fiber; solar lighting</p>
27
Trenkenshu, Rudolf P., Alexander S. Lelekov, and Anatoliy A. Chekushkin. "Application of linear splines to simulate daily changes in insolation." Issues of modern algology (Вопросы современной альгологии), no. 3(24) (2020): 42–49. http://dx.doi.org/10.33624/2311-0147-2020-3(24)-42-49.
Full textAbstract:
The paper shows the possibility of using linear splines in modeling the daily change in solar radiation. The calculations were based on the generally accepted cosine expression used for modeling insolation changes on the surface of lakes and the ocean. The equation parameters are set for the conditions of Sevastopol (44°35'N, 33°30' E): the maximum height of the sun above the horizon is about 68 degrees, the day length is 15 hours. The model curve was divided into three sections. For the early morning hours and late evening, the sunlight intensity is low and is below the “compensation point” of photosynthesis. So these areas were not considered during modeling. Three sites: the increase in irradiation from 6 to 12 hours, the maximum irradiation from 12 to 14 hours, and the decrease in irradiation from 14 to 20 hours are described by linear equations. It is shown that the deviations in the description of the data of the dependence of the sunlight intensity on the time of day by linear splines from the generally accepted formula in the form of a cosine do not exceed 5%. An example of experimental data of linear growth of productivity of A. platensis culture is given. Based on the assumption that the growth rate of microalgae culture is proportional to the amount of energy absorbed, the linear increase in productivity can be explained by a linear increase in the intensity of sunlight.
28
Herrera, Esteban A., and Jesus Arreola. "247 Sunlight Penetration Before and After Pecan Orchard Thinning: Its Influence on Shoot Growth, Nut Production and Quality." HortScience 34, no. 3 (June 1999): 484F—485. http://dx.doi.org/10.21273/hortsci.34.3.484f.
Full textAbstract:
This study was performed during 1995, 1996, and 1997 seasons in a mature pecan orchard thinned 25% in 1993, 1994, or 1995. In the orchard section thinned in 1994, more trees were removed in 1995 to reach 50% thinning. Shoot length in eight sides of the canopy periphery was measured in each growing season. Shoot growth was increased in thinned orchard sections compared with the unthinned orchard areas. Shoot growth during 1995 and 1996 was higher for trees sections thinned 25% in 1993 and 1994. Regardless of thinning years, shoot length was lower in the north side than in other canopy sides. A trend for nut yield increment was observed in thinned orchard blocks, especially where 50% tree removal was performed. Nut quality expressed in kernel percent was more related with crop load than to thinning percent or thinning year.
29
Dang, Q. L., V. J. Lieffers, and R. L. Rothwell. "Effects of summer frosts and subsequent shade on foliage gas exchange in peatland tamarack and black spruce." Canadian Journal of Forest Research 22, no. 7 (July 1, 1992): 973–79. http://dx.doi.org/10.1139/x92-130.
Full textAbstract:
In this study, we examined the effect of summer frost on light-saturated net photosynthesis (Pnet) and related parameters in 20-year-old black spruce (Piceamariana (Mill.) B.S.P.) and tamarack (Larixlaricina (Du Roi) K. Koch) at a peatland site in central Alberta. Summer frosts were simulated in the field using a self-contained freezing chamber. Some trees were shaded from direct sunlight after freezing. Shaded trees received about 20% of full sunlight at midday. We found that the response of photosynthesis consisted of two phases: a depression phase, where photosynthesis declined progressively, and a recovery phase, where photosynthesis recovered gradually. The length of the depression phase varied with species but not with the degree of freezing. For both species, depression in Pnet was primarily related to decreased mesophyll conductance to CO2, and a full recovery of Pnet took more than 11 days. Post-frost shade enhanced recovery in Pnet after a −3.5 °C frost in tamarack, but had no detectable effect after a −6 °C frost in tamarack or a −3 °C frost in black spruce.
30
Lee, David W. "Simulating forest shade to study the developmental ecology of tropical plants: juvenile growth in three vines in India." Journal of Tropical Ecology 4, no. 3 (August 1988): 281–92. http://dx.doi.org/10.1017/s0266467400002844.
Full textAbstract:
ABSTRACTBoth light quantity and quality affect the development and autoecology of plants under shade conditions, as in the understorey of tropical forests. However, little research has been directed towards the relative contributions of lowered photosynthetic photon flux density (PPFD) versus altered spectral distributions (as indicated by quantum ratios of 660 to 730 nm, or R:FR) of radiation underneath vegetation canopies. A method for constructing shade enclosures to study the contribution of these two variables is described. Three tropical leguminous vine species (Abrus precatonus L., Caesalpinia bondicela Fleming and Mucuna prunens (L.) DC) were grown in two shade enclosures with 3–4% of solar PPFD with either the R:FR of sunlight (1.10) or foliage shade (0.33), and compared to plants grown in sunlight. Most species treated with low R:FR differed from those treated with high R:FR in (1) percent allocation to dry leaf weight, (2) internode length, (3) dry stem weight/length, (4) specific leaf weight, (5) leaf size, and (6) chlorophyll a/b ratios. However, these plants did not differ in chlorophyll content per leaf dry weight or area. In most cases the effects of low R:FR and PPFD were additional to those of high R:FR and low PPFD. Growth patterns varied among the three species, but both low PPFD and diminished R:FR were important cues in their developmental responses to light environments. This shadehouse system should be useful in studying the effects of light on the developmental ecology of other tropical forest plants.
31
Paschoal, LRP, DP Andrade, and G. Darrigran. "How the fluctuations of water levels affect populations of invasive bivalve Corbicula fluminea (Müller, 1774) in a Neotropical reservoir?" Brazilian Journal of Biology 75, no. 1 (March 2015): 135–43. http://dx.doi.org/10.1590/1519-6984.09113.
Full textAbstract:
Corbicula fluminea is an invasive bivalve responsible for several environmental and financial problems around the globe. Despite the invasive potential of this species, it suffers certain restrictions in lentic environments due to natural phenomena that significantly affect its population structure (e.g. water column fluctuation and sunlight exposure). The present study addresses how temporal decline of the water level in a Neotropical reservoir and exposure to sunlight affect the population structure of C. fluminea. Samplings were carried out twice in the reservoir of Furnas Hydroelectric Power Station (HPS) (Minas Gerais, Brazil), in 2011 and 2012. Population density, spatial distribution and mean shell length of C. fluminea were estimated for each year after sampling in 51 quadrats (0.0625m2) placed on three transects at different distances along the reservoir margins (0, 10 and 20 m from a fixed-point). We observed a predominance of C. fluminea in both years, with a simultaneous gradual decrease in density and richness of native species in the sampling area. Significant differences in density of C. fluminea were registered at different distances from the margin, and are related to the temporal variability of physical conditions of the sediment and water in these environments. We also registered a trend toward an increase in the density and aggregation of C. fluminea as we moved away from the margin, due to the greater stability of these areas (>10 m). The mean shell length of C. fluminea showed significant difference between the distinct distances from the margin and during the years, as well as the interaction of these factors (Distances vs.Years). These results were associated with the reproductive and invasive capacity of this species. This study reveals that these temporal events (especially water column fluctuation) may cause alterations in density, spatial distribution and mean shell length of C. fluminea and the composition of the native malacofauna in Neotropical lentic environments.
32
Boehm, Alexandria B., Cherrie Soetjipto, and Dan Wang. "Solar inactivation of four Salmonella serovars in fresh and marine waters." Journal of Water and Health 10, no. 4 (October 11, 2012): 504–10. http://dx.doi.org/10.2166/wh.2012.084.
Full textAbstract:
Sunlight-mediated disinfection of water is of interest to both the drinking and recreational water quality community of researchers due to its potential to reduce microbial contamination and waterborne illness. Photo-inactivation of enteric bacteria has primarily been investigated using Escherichia coli and laboratory strains of model bacteria. The present study sought to document the photo-inactivation of environmental isolates of Salmonella in filter-sterilized natural seawater and freshwater and to test the hypothesis that diverse Salmonella serovars decay at similar rates both within and between water matrices. The inactivation of Salmonella enterica Typhimurium LT2, Typhimurium ST19, Heidelberg, and Mbandaka was examined in sunlit and dark microcosms. First order decay was observed in sunlit microcosms; the time until 90% inactivation was of the order of 10 min. A significant shoulder, of the order of 1 hr in length, was observed in the freshwater microcosms during which concentrations were stable. Serovar Mdandaka decayed more slowly than other serovars in both seawater and freshwater. The serovars were extremely stable in the dark microcosms showing little to no decay over 53 days. The results document intra-species variation in photo-inactivation, likely owing to differences in intracellular concentrations of photo-sensitizing molecules or molecules that quench reactive species.
33
Nurdianna, Daru, Retno Bandriyati Arni Putri, and Dwi Harjoko. "Penggunaan Beberapa Komposisi Spektrum Led Pada Potensi Dan Hasil Hidroponik Indoor Selada Keriting Hijau." Agrosains: Jurnal Penelitian Agronomi 20, no. 1 (September 27, 2018): 1. http://dx.doi.org/10.20961/agsjpa.v20i1.26310.
Full textAbstract:
This study aims to determine the differences in the growth response of green curly lettuce to the differentiation treatment of LED lighting with different spectrum in indoor hydroponics. The research was conducted from October to November 2017. The experimental design used was experimental with 1 lighting factor with 5 levels, there are sunlight (P0), LED 20% blue: 80% red (P1), LED 80% blue: 20% red (P2), 50% blue LED: 50 % red (P3), and 100% white daylight (P4). Observational variables included plant height, leaf number, leaf area, leaf color, total wet weight, leaf wet weight, wet root weight and dry weight of the plant. The result of this experiment showed that LED irradiation have affect the treatment are plant height, leaf number, leaf area, chlorophyll content, fresh weight of harvest, root length, and dry weight of brackets. While those that have no significant effect are the wet weight of the roots. The results showed that between LED irradiation treatment L1, L2, L3, and L4 showed that treatment L2 with 80% blue spectrum composition: 20% red showed better growth based on: high plant, chlorophyll content, and root length. Treatment with L4 with white LED showed better growth based on the number of leaves, leaf area, fresh weight of harvest, root wet weight, and dry weight of total biomass. The results below the sunlight better than the LED irradiation treatment, because the intensity of LED far low and lack of controlled environmental conditions technology and management for growing lettuce. In all of LED treatment still looked etiolation because light intensity was not optimal yet.
34
Siniarska, A., and S. Kozieł. "Association of birth weight and length with air temperature, sunlight, humidity and rainfall in the city of Warsaw, Poland." HOMO 61, no. 5 (October 2010): 373–80. http://dx.doi.org/10.1016/j.jchb.2010.07.001.
Full text
35
Vitt, Simon, Janina E. Zierul, Theo C. M. Bakker, and Ingolf P. Rick. "Long-term UVB exposure promotes predator-inspection behaviour in a fish." Biology Letters 13, no. 12 (December 2017): 20170497. http://dx.doi.org/10.1098/rsbl.2017.0497.
Full textAbstract:
Ultraviolet-B radiation (UVB) reaching the earth's surface has increased due to human-caused stratospheric ozone depletion. Whereas the harmful effects of UVB on aquatic organisms are well studied at the molecular and cellular level, recent studies have also begun to address behavioural changes caused by sublethal amounts of UVB. However, the behavioural consequences of long-term exposure to ecologically relevant UVB levels over several life stages are virtually unknown, particularly with regard to predator–prey behaviour. We found increased predator-inspection behaviour together with a smaller body length in three-spined sticklebacks ( Gasterosteus aculeatus ) after fish were exposed for about seven months to natural sunlight conditions with enhanced UVB, compared with full siblings exposed to natural sunlight only. The observed change in antipredator behaviour may reflect a direct behavioural response mediated through UVB-induced oxidative stress during development. Alternatively, the smaller body size in UVB-exposed fish may result in an increased inspection effort allowing them to spend more time foraging. Our findings suggest that, within the scope of environmental change, UVB radiation constitutes an important stress factor by eliciting behavioural responses that influence crucial ecological processes, such as predator–prey interactions.
36
Masrufa, Sadia, Anisur Rahman, Md Hasanuzzaman, Taufika Islam Anee, Md Hazrat Ali, and Mirza Hasanuzzaman. "Pre-Planting Hardening-Induced Variability in Yield Attributes and Yield of Inbreed and Hybrid Rice." Bangladesh Agronomy Journal 19, no. 1 (October 9, 2016): 87–97. http://dx.doi.org/10.3329/baj.v19i1.29875.
Full textAbstract:
Short term hardening before transplanting may enhance the defence mechanism of rice seedlings against any stress during their establishment and contribute d to enhanced growth and yield. Thus, this study was conducted involving one local inbred (Pajam), one popular high yielding (BRRI dhan53) and one hybrid (BRRI hybrid dhan4) rice variety. The experiment was laid out in randomized complete block design with two factors. Seedlings were transplanted directly to the main field as a control treatment and/or subjected to four different hardenings like seedlings storage in shade, open field under sunlight, float in water and cold air in refrigerator before transplantation. Hybrid variety out yielded both the local and inbred varieties due to their highest effective tillers, longer panicle length and 1000-grain weight. Pre-hardening of seedlings in open field under sunlight conditions enhanced the yield attributes and ultimate yield of rice compare to others. The best combination was pre-hardening seedlings in open field conditions with hybrid cultivar regarding to the yield attributes and final yields. It is suggested that hybrid variety and prehardening of seedlings before transplantation to the main field could be increase the rice yield productionsBangladesh Agron. J. 2016, 19(1): 87-97
37
Xu, Tian Yue, Yu Zhang, Ke Bi, and Tie Qiang Zhang. "Simulation and Size Optimization of PbSe Quantum Dots Luminescent Solar Concentrator." Advanced Materials Research 900 (February 2014): 213–16. http://dx.doi.org/10.4028/www.scientific.net/amr.900.213.
Full textAbstract:
PbSe quantum dots have a relavively narrow absorption spectrum and they can radiate quasi monochromatic light after absorbing sunlight. Also, the emission peak can be located in the range of the strongest spectral response of monocrystal silicon solar cell by adjusting particles sizes. In this paper we apply PbSe quantum dots into luminescent solar concentrator, analyse its physical process, establish mathematical model and optimize its size with C++. The simulation results show that its photoelectric conversion efficiency is size depended, when the length and width are 200cm and 150cm, respectively, its photoelectric transformation efficiency can reach 6.1%.
38
Sousa, Geocleber G. de, Sinara B. Sousa, Ana C. da S. Pereira, Virna B. Marques, Maria L. G. da Silva, and Jayrla da S. Lopes. "Effect of saline water and shading on dragon fruit (‘pitaya’) seedling growth." Revista Brasileira de Engenharia Agrícola e Ambiental 25, no. 8 (August 2021): 547–52. http://dx.doi.org/10.1590/1807-1929/agriambi.v25n8p547-552.
Full textAbstract:
ABSTRACT ‘Pitaya’ (Hylocereus undatus) is a fruit-bearing, climbing cactus with great food potential for the semiarid region. This study aimed to evaluate the production of ‘pitaya’ seedlings irrigated with low and high salinity water and grown in different light intensities. The experiment was conducted in a completely randomized design, in a 2 × 2 factorial arrangement, with two electrical conductivities of irrigation water: S1 - 0.3 dS m-1 (low salinity) and S2 - 5.0 dS m-1 (moderate salinity) in two environments: A1 - black net with 50% shading, and A2 - full sun, with ten replicates. The variables evaluated were plant height, main cladode diameter, above-ground biomass, root biomass, total plant biomass, number of secondary cladodes, root length, and length of secondary cladodes. The 50% shading (black net) promoted higher plant height, number of secondary shoots, and root length of the ‘pitaya’ plants. The irrigation with moderate saline water (5.0 dS m-1) reduced the number of secondary cladodes, length of root, and length of secondary cladodes. The ‘pitaya’ seedlings grown under 50% shading (black net) showed greater root dry biomass when irrigated with low-salinity water. Greater values of diameter of the primary cladode, above-ground dry biomass, and total dry biomass were observed under full sunlight and elevated saline stress.
39
Messier, Christian, and Pasi Puttonen. "Growth, allocation, and morphological responses of Betulapubescens and Betulapendula to shade in developing Scots pine stands." Canadian Journal of Forest Research 25, no. 4 (April 1, 1995): 629–37. http://dx.doi.org/10.1139/x95-070.
Full textAbstract:
The growth, biomass allocation, crown architecture, and leaf morphology of 50 to 200 cm tall Betulapubescens Ehrh. and Betulapendula Roth seedlings growing under eight Scots pine (Pinussylvestris L.) stands varying in age from 7 to 105 years were studied in southern Finland. The main objective of the study was to assess the degree of morphological plasticity of birch in response to understory conditions in stands of varying structure. In each of these stands, the light, water, and nutrient availability were measured. No clear trend in nutrient and water availability was found from the 7- to 105-year-old stands. Light availability decreased from the 7-year-old stands (45% and 82% of full sunlight in nongap and gap locations, respectively) to the 20-year-old stands (5% and 12% of full sunlight), and then increased to the mature stands (21% and 26% of full sunlight). Relative branch growth rate and height increment decreased with increasing shade. The ratios of leaf area to branch length and to branch weight did not vary significantly among the eight stands. The ratios of height to diameter and fine-root biomass to leaf biomass were the highest under the most shaded stands (20-year-old). Increase in shading decreased leaf thickness and increased specific leaf weight. No major differences were found in any of the growth parameters measured between the two birch species, indicating that they do not differ in their juvenile stage. These results indicate that these two birch species have relatively little morphological plasticity in response to shade. They appear to be able to persist in shade by minimizing carbon demand for growth and by modifying leaf morphology to presumably optimize photosynthesis.
40
PRASTIWI, DYAH ISNAINI, DEDI SOEDHARMA, and BEGINER SUBHAN. "Growth of transplanted soft corals Lobophytum strictum on recirculation system with different light conditions." Bonorowo Wetlands 2, no. 1 (June 4, 2012): 31–39. http://dx.doi.org/10.13057/bonorowo/w020104.
Full textAbstract:
Prastiwi DI, Soedharma D, Subhan B. 2012. Growth of transplanted soft corals Lobophytum strictum on recirculation system with different light conditions. Bonorowo Wetlands 2: 31-39. The study was conducted from August 2010 to January 2011 at the Laboratory of the Marine Science Research Center, Bogor Agricultural University, Ancol, North Jakarta using different lighting treatment at the observation pond. The first pond opened and the second pond closed using a tarpaulin. The total data of soft coral Lobophytum strictum growth was analyzed using Completely Randomized Design method. Measurements of soft coral include absolute growth, growth rate, and survival rates. In open ponds, survival rates of soft coral reached 100% until the end of the study, whereas in closed ponds (without light) only survived for 8 weeks. The average growth rate of soft coral ranged from 5.95 ± 0.31cm to 10.04 ± 0.6 cm. At the start of the study, the average width of soft coral fragments in open ponds was 5.27 ± 0.51 cm and by the end of 12 weeks, the study increased to 6.84 ± 0.72 cm. The average growth of the length and width of the soft corals in closed pond decreases every week. At the end of the study, the soft coral length was reduced by 3.55 cm, while the width was reduced by 4.28 cm. Sunlight plays an important role in the life of soft corals; this is due to the presence of zooxanthellae microsimulation that requires sunlight to photosynthesize. The results show that the survival rate of soft corals in open ponds is better than closed ponds. Analysis of variance shows that the growth of soft corals is significantly affected by light.
41
Li, Jing, and Yu Liu. "Study on Design Strategies for Improving Outdoor Thermal Comfort in the Cold Regions of China." Advanced Materials Research 250-253 (May 2011): 3798–801. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.3798.
Full textAbstract:
Along with the improvement of dwelling quality, the length of time and frequency of outdoor activities in winter greatly increase in the north China area, although the outdoor thermal environments are still unsatisfactory. It is necessary for both planners and architects to improve outdoor thermal environments in the cold regions of north China. This paper firstly introduces the general winter climate features in some north China cities. Then, it takes Xi'an city as an example to show the shortage of uncomfortable outdoor environment. Thirdly, the design strategies to improve outdoors thermal comfort include wind and snow protection, sunlight usage, environmental zones and recreational facilities, etc. are discussed.
42
Slabejová, Gabriela, and Zuzana Vidholdová. "Photostability of Transparent Surface Coatings of Wood." Materials Science Forum 818 (May 2015): 198–201. http://dx.doi.org/10.4028/www.scientific.net/msf.818.198.
Full textAbstract:
The paper deals with the evaluation of photostability of six selected transparent surface coatings applied on veneered furniture parts. It also estimates the influence factors such as exposure to natural sunlight in the interior, the length of exposure, wood species of used veneers and type of transparent coatings. The changing colour of surface treatment was evaluated on samples stored in the interior and being exposed to natural light behind the window glass for 6 months. Significant changes were occurred on surfaces treated with transparent coatings without UV absorber. During the first three months of exposure were arisen the most colour changes in transparent coatings of veneers.
43
Binti Haji Yassin, Siti Nur'ain, Nur Afifah Haniyyah Halidi, Soong Leong Sim, Ye Ru Liu, and James Robert Jennings. "Electron Diffusion Length and Charge Separation Efficiency in Nanostructured Ternary Metal Vanadate Photoelectrodes." Materials Science Forum 941 (December 2018): 2121–27. http://dx.doi.org/10.4028/www.scientific.net/msf.941.2121.
Full textAbstract:
Ternary metal vanadates have recently emerged as promising photoelectrode materials for sunlight-driven water splitting. Here, we show that highly active nanostructured BiVO4films can be deposited onto fluorine-doped tin oxide (FTO) substrates by a facile sequential dipping method known as successive ionic layer adsorption and reaction (SILAR). After annealing and deposition of a cobalt phosphate (Co-Pi) co-catalyst, the photoelectrodes produce anodic photocurrents (under 100 mW cm-2broadband illumination, 1.23 Vvs. RHE) in pH 7 phosphate buffer that are on par with the highest reported in the literature for similar materials. To gain insight into the reason for the good performance of the deposited films, and to identify factors limiting their performance, incident photon-to-electron conversion efficiency spectra have been analyzed using a simple diffusion–reaction model to quantify the electron diffusion length (Ln; the average distance travelled before recombination) and charge separation efficiency (ηsep) in the films. The results indicate thatηsepapproaches unity at sufficiently positive applied potential but the photocurrent is limited by significant charge collection losses due to a shortLnrelative to the film thickness. The Co-Pi catalyst is found to improveηsepat low potentials as well as increaseLnat all potentials studied. These findings help to clarify the role of the Co-Pi co-catalyst and show that there could be room for improvement of BiVO4photoanodes deposited by SILAR ifLncan be increased.
44
Rosli, Siti Azlina, Nurhaswani Alias, Nurulhuda Bashirom, Syahriza Ismail, Wai Kian Tan, Go Kawamura, Atsunori Matsuda, and Zainovia Lockman. "Hexavalent Chromium Removal via Photoreduction by Sunlight on Titanium–Dioxide Nanotubes Formed by Anodization with a Fluorinated Glycerol–Water Electrolyte." Catalysts 11, no. 3 (March 13, 2021): 376. http://dx.doi.org/10.3390/catal11030376.
Full textAbstract:
In this paper, titanium–dioxide (TiO2) nanotubes (TNTs) are formed by anodic oxidation with a fluorinated glycerol–water (85% and 15%, respectively) electrolyte to examine the effect of fluoride ion concentration, time, and applied voltage on TNT morphologies and dimensions. For fluoride ion concentration, the surface etching increases when the amount of ammonium fluoride added to the electrolyte solution increases, forming nanotube arrays with a clear pore structure. At a constant voltage of 20 V, TNTs with an average length of ~2 µm are obtained after anodization for 180 min. A prolonged anodization time only results in a marginal length increment. The TNT diameter is voltage dependent and increases from approximately 30 nm at 10 V to 310 nm at 60 V. At 80 V, the structure is destroyed. TNTs formed at 20 V for 180 min are annealed to induce the TiO2 anatase phase in either air or nitrogen. When ethylenediaminetetraacetic acid is added as a hole scavenger, 100% hexavalent chromium removal is obtained after 120 min of sunlight exposure for nitrogen-annealed TNTs.
45
Barua, Saumen, and Ujjwal Kumar Deb. "Hydrodynamics of Microalgae and CO2 flow in a Tubular Photobioreactor and consequent effects on Microalgae growth." Rajshahi University Journal of Science and Engineering 44 (November 19, 2016): 75–83. http://dx.doi.org/10.3329/rujse.v44i0.30390.
Full textAbstract:
In biofuel technology from microalgae, the main optimal factors for microalgae cultivations are light, CO2 and temperature. As microalgae are photosynthetic microorganisms thus they convert sunlight, water and CO2 to algal biomass. We consider a two phase flow for CO2 and Microalgae suspension to understand fluid dynamics phenomena after injecting CO2 gas inside a tubular Photobioreactor (PBR).The growth rate of the microalgae cell is taken as a function of available sun light at Chittagong University of Engineering & Technology (CUET) in our study. A 20.94m long and 0.025m tubular PBR is considered for the simulation. To observe the microalgae cell growth, we selected the 21st June for a bright sunny and the longest day of a year. From the simulation after day seven we observed a very slow growth for the microalgae culture. It is noted that the growth related to concentration of microalgae is increased by day length with respect to continuous sunlight. A small fluctuation of shear rate around Uloop area is also found in our simulation which may be caused to reduce the volumetric production due to cell fragility. From the velocity profile we found that, the velocity is generally higher in the middle of the tube gives a parabolic shape of the suspension flow.
46
Cavalcante, Fábio, Geocleber Gomes de Sousa, Márcio Henrique da Costa Freire, Elizeu Matos da Cruz Filho, Rute Maria Rocha Ribeiro, and Kelly Nascimento Leite. "Radish production under different shading screens and mulching." Comunicata Scientiae 11 (July 13, 2020): e3401. http://dx.doi.org/10.14295/cs.v11i0.3401.
Full textAbstract:
Shading Screens and mulching may provide a favorable environment for radish growing in regions of adverse climates. This work aimed to evaluate the radish productivity under the influence of different shading screens associated with the presence and absence of mulch in two different years. The experiment was carried out in two different seasons (2017 dry season and 2018 rainy season), in the vegetable garden of Liberdade campus, at the University of International Integration of Afro-Brazilian Lusophony (Unilab), municipality of Redenção-CE. The experimental design was in randomized blocks in a split-plot arrangement, with four repetitions, in which the plots consisted of growing with and without mulching and in the subplots, five shading screens: 50% Black Shading Screen (50% BSS), 50% Red Shading Screen (50% RSS), 30% White Shading Screen (30% WSS), 70% Black Shading Screen (70% BSS) ), and full sunlight (FS). The red shading screens 50% and white 30%, in addition to cultivation under full sunlight, provide higher performance in terms of the number of leaves, tuberous root diameter, tuberous root matter, and the radish crop productivity, regardless of the evaluated period. The applied mulch does not influence the productivity of the rabante, influencing only the gain of dry mass of the aerial part, soluble solids and length of the tuberous root.
47
Peavey, Madeleine, Ian Goodwin, Lexie McClymont, and Subhash Chandra. "Effect of Shading on Red Colour and Fruit Quality in Blush Pears “ANP-0118” and “ANP-0131”." Plants 9, no. 2 (February 6, 2020): 206. http://dx.doi.org/10.3390/plants9020206.
Full textAbstract:
Some cultivars of Pyrus communis develop mature fruit with a distinctive red blush. Investigating the patterns of pear colour development in response to sunlight has implications for orchard management of these pears. The objectives of these experiments are to study the seasonal patterns of colour development and investigate the influence of shade and sunlight exposure on the red colour and harvest quality of blush pears “ANP-0118” and “ANP-0131”. Several long, medium and short shading treatments were applied at different stages of fruit development from 28 (“ANP-0131”) and 29 (“ANP-0118”) days after full bloom (DAFB) until harvests at 119 DAFB (“ANP-0118”) and 175 DAFB (“ANP-0131”). Fruits were measured every three weeks for colour parameters (a*, hue angle, chroma) and at harvest for quality parameters (fresh weight, visual assessments of percentage blush coverage and blush intensity, flesh firmness and soluble solids concentration). In the unshaded control, red colour increased during the growing season (increase in a* value and decrease in hue angle), as well as increasing in chroma value. Periods of shading during the season negatively affected red colour in both cultivars, as evidenced by significant decreases in a* value and increases in hue angle. Shaded fruits that were subsequently re-exposed to sunlight reacted with a dynamic increase in a* value and decrease in hue angle. Fruit shaded for the length of the experiment or prior to harvest had significantly lower a* values than the control at harvest. Visual assessment at harvest of percentage blush coverage and blush intensity were significantly affected by shading in both cultivars. Shading treatments applied early in the experiment had a negative effect on the fresh fruit weight of “ANP-0118”.
48
Durigon, Angelica, Jochem Evers, Klaas Metselaar, and Quirijn de Jong van Lier. "Water Stress Permanently Alters Shoot Architecture in Common Bean Plants." Agronomy 9, no. 3 (March 26, 2019): 160. http://dx.doi.org/10.3390/agronomy9030160.
Full textAbstract:
The effects of water stress on crop yield through modifications of plant architecture are vital to crop performance such as common bean plants. To assess the extent of this effect, an outdoor experiment was conducted in which common bean plants received five treatments: fully irrigated, and irrigation deficits of 30% and 50% applied in flowering or pod formation stages onwards. Evapotranspiration, number and length of pods, shoot biomass, grain yield and harvest index were assessed, and architectural traits (length and thickness of internodes, length of petioles and petiolules, length and width of leaflet blades and angles) were recorded and analyzed using regression models. The highest irrigation deficit in the flowering stage had the most pronounced effect on plant architecture. Stressed plants were shorter, leaves were smaller and pointing downward, indicating that plants permanently altered their exposure to sunlight. The combined effect of irrigation deficit and less exposure to light lead to shorter pods, less shoot biomass and lower grain yield. Fitted empirical models between water deficit and plant architecture can be included in architectural simulation models to quantify plant light interception under water stress, which, in turn, can supply crop models adding a second order of water stress effects on crop yield simulation.
49
Hönninger, G., C. von Friedeburg, and U. Platt. "Multi axis differential optical absorption spectroscopy (MAX-DOAS)." Atmospheric Chemistry and Physics 4, no. 1 (February 9, 2004): 231–54. http://dx.doi.org/10.5194/acp-4-231-2004.
Full textAbstract:
Abstract. Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) in the atmosphere is a novel measurement technique that represents a significant advance on the well-established zenith scattered sunlight DOAS instruments which are mainly sensitive to stratospheric absorbers. MAX-DOAS utilizes scattered sunlight received from multiple viewing directions. The spatial distribution of various trace gases close to the instrument can be derived by combining several viewing directions. Ground based MAX-DOAS is highly sensitive to absorbers in the lowest few kilometres of the atmosphere and vertical profile information can be retrieved by combining the measurements with Radiative Transfer Model (RTM) calculations. The potential of the technique for a wide variety of studies of tropospheric trace species and its (few) limitations are discussed. A Monte Carlo RTM is applied to calculate Airmass Factors (AMF) for the various viewing geometries of MAX-DOAS. Airmass Factors can be used to quantify the light path length within the absorber layers. The airmass factor dependencies on the viewing direction and the influence of several parameters (trace gas profile, ground albedo, aerosol profile and type, solar zenith and azimuth angles) are investigated. In addition we give a brief description of the instrumental MAX-DOAS systems realised and deployed so far. The results of the RTM studies are compared to several examples of recent MAX-DOAS field experiments and an outlook for future possible applications is given.
50
Hönninger, G., C. von Friedeburg, and U. Platt. "Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS)." Atmospheric Chemistry and Physics Discussions 3, no. 6 (November 11, 2003): 5595–658. http://dx.doi.org/10.5194/acpd-3-5595-2003.
Full textAbstract:
Abstract. Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) is a novel measurement technique that represents a significant advance on the well-established zenith scattered sunlight DOAS instruments which are mainly sensitive to stratospheric absorbers. MAX-DOAS utilizes scattered sunlight received from multiple viewing directions. The spatial distribution of various trace gases close to the instrument can be derived by combining several viewing directions. Ground based MAX-DOAS is highly sensitive to absorbers in the lowest few kilometres of the atmosphere and vertical profile information can be retrieved by combining the measurements with Radiative Transfer Model (RTM) calculations. The potential of the technique for a wide variety of studies of tropospheric trace species and its (few) limitations are discussed. A Monte Carlo RTM is applied to calculate Airmass Factors (AMF) for the various viewing geometries of MAX-DOAS. Airmass Factors can be used to quantify the light path length within the absorber layers. The airmass factor dependencies on the viewing direction and the influence of several parameters (trace gas profile, ground albedo, aerosol profile and type, solar zenith and azimuth angles) are investigated. In addition we give a brief description of the instrumental MAX-DOAS systems realised and deployed so far. The results of the RTM studies are compared to several examples of recent MAX-DOAS field experiments and an outlook for future possible applications is given.