Light transmission in window-leaved plants

1980 ◽  
Vol 58 (14) ◽  
pp. 1591-1600 ◽  
Author(s):  
Gerald A. Krulik
Keyword(s):  
Light Transmission ◽  
Incident Light ◽  
Water Storage ◽  
Soil Surface ◽  
Scanning Electron Micrographs ◽  
Light Penetration ◽  
Storage Tissue ◽  
Desert Regions ◽  
Succulent Plants ◽  
Highly Evolved

Window-leaved plants are succulent plants which possess areas of clear epidermis on their leaves. The underlying water storage tissue is transparent to allow light penetration to the internal chlorenchyma. The most highly evolved window-leaved plants with the most transparent tissue grow completely underground in desert regions. Only the rounded leaf tips are level with the soil surface and directly exposed to incident light. Light transmission curves were measured using live windows of five species of plants from three families (Liliaceae, Piperaceae, Mesembryanthemaceae). These results suggest that subterranean window leaves may be limited to a relatively short effective maximum length because of light absorption by the tissues involved. Scanning electron micrographs (SEM) of these plants show considerable differences in surface structure which may help to modulate incident light. Comparisons with related Mesembryanthemaceae illustrate that a complex series of adaptations have been developed to allow underground growth.

scholarly journals Evaporation and Soil Surface Resistance of the Water Storage Pit Irrigation Trees in the Loess Plateau

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 648 ◽  
Author(s):  
Wei Meng ◽  
Xihuan Sun ◽  
Juanjuan Ma ◽  
Xianghong Guo ◽  
Lijian Zheng
Keyword(s):  
Surface Resistance ◽  
Water Storage ◽  
Growth Period ◽  
Soil Surface ◽  
Soil Evaporation ◽  
Utilization Efficiency ◽  
The Loess Plateau ◽  
Surface Evaporation ◽  
Orchard Soil ◽  
Quantitative Calculations

As an important step for formulating a water-saving agricultural strategy, it is essential to make quantitative calculations for orchard soil evaporation and confirm its inner mechanism, so as to reduce ineffective water consumption and improve the utilization efficiency of water resources. To reveal the effect of water storage pits under water storage pit irrigation conditions in orchard soil evaporation, micro-lysimeters were used to measure the soil evaporation in two different forms (soil surface evaporation and pit wall evaporation) under diverse irrigation systems using water storage pit irrigation in the apple growth period of 2018. To calculate the orchard soil evaporation of water storage pit irrigation, the pit irrigation coefficient was introduced and a model was constructed. To illustrate the inner mechanism of orchard soil evaporation, the soil surface resistance under water storage pit irrigation conditions was analyzed and calculated quantitatively. The results show that: (1) introducing the pit irrigation coefficient can boost the calculation precision of the orchard soil evaporation under water storage pit irrigation conditions; (2) when applying the soil evaporation of the water storage pit irrigation model for calculation of the orchard soil evaporation, R 2 can reach 0.92; and (3) the mechanisms of the two orchard soil evaporation forms under water storage pit irrigation are very different. When soil surface evaporation and pit wall evaporation were calculated by the soil surface resistance of water storage pit irrigation model, R 2 values were 0.95 and 0.96, respectively.

Water Storage and Controlled-Release Film(WSCF) Materials Used in Tree Planting in Desert Regions

2011 ◽  
Vol 356-360 ◽  
pp. 467-470
Author(s):  
Gui Quan Han ◽  
Zhao Xiang Han ◽  
Dong En Zhang ◽  
Zeng Zhi Zhang
Keyword(s):  
Controlled Release ◽  
Polymer Composite ◽  
Environmental Conditions ◽  
Water Storage ◽  
Tree Planting ◽  
Desert Regions ◽  
Materials Used

Water Storage and Controlled-release Film (WSCF) is a new kind of polymer composite with the function of releasing water slowly in a given period. This paper resumptively introduces the importance of water storage and controlled-release film (WSCF) material for tree planning in desertified regions. Microstructures of WSCF were studied and experiments were also carried out successively in various environmental conditions.

scholarly journals Localized Surface Plasmons Enhanced Light Transmission into c-Silicon Solar Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Y. Premkumar Singh ◽  
Amit Jain ◽  
Avinashi Kapoor
Keyword(s):  
Solar Cells ◽  
Metallic Nanoparticles ◽  
Large Scale ◽  
Light Transmission ◽  
Low Cost ◽  
Incident Light ◽  
Solar Spectrum ◽  
Localized Surface Plasmon ◽  
Plasmonic Nanostructures ◽  
Al Nanoparticles

The paper investigates the light incoupling into c-Si solar cells due to the excitation of localized surface plasmon resonances in periodic metallic nanoparticles by finite-difference time-domain (FDTD) technique. A significant enhancement of AM1.5G solar radiation transmission has been demonstrated by depositing nanoparticles of various metals on the upper surface of a semi-infinite Si substrate. Plasmonic nanostructures located close to the cell surface can scatter incident light efficiently into the cell. Al nanoparticles were found to be superior to Ag, Cu, and Au nanoparticles due to the improved transmission of light over almost the entire solar spectrum and, thus, can be a potential low-cost plasmonic metal for large-scale implementation of solar cells.

RESONANT LIGHT TRANSMISSION IN METALLIC PHOTONIC CRYSTAL SLABS

2002 ◽  
Vol 01 (05n06) ◽  
pp. 657-661 ◽  
Author(s):  
XIANGANG LUO ◽  
TERUYA ISHIHARA
Keyword(s):  
Photonic Crystal ◽  
Light Transmission ◽  
Visible Region ◽  
Metal Structure ◽  
Light Penetration ◽  
Metallic System ◽  
Photonic Crystal Slabs ◽  
Wide Range ◽  
Resonant Emission ◽  
Metallic Photonic Crystal

Light transmission through an opaque nanoscale metallic photonic crystal slabs (MPCS) are investigated. The experimental results show that it is possible to get the extraordinary transmission in visible region even without the presence of holes, which is different from the perforated nanoholes or nanoslits in metallic system. The observed phenomenon can be understood in terms of surface plasmon-enhanced resonant emission of light through a metal structure with a nanoscale corrugation rather than light penetration through tiny holes. It is the periodicity of the interface corrugation that is important for the plasmon as a radiative channel rather than loss. The study suggests that a wide range of photonic applications is possible for such system.

scholarly journals The anatomy of the foveola reinvestigated

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4482 ◽  
Author(s):  
Alexander V. Tschulakow ◽  
Theo Oltrup ◽  
Thomas Bende ◽  
Sebastian Schmelzle ◽  
Ulrich Schraermeyer
Keyword(s):  
Light Beam ◽  
Focused Ion Beam ◽  
Light Transmission ◽  
Ion Beam ◽  
Incident Light ◽  
3D Structure ◽  
Müller Cells ◽  
Bright Spot ◽  
Muller Cells ◽  
Outer Segments

Objective In the foveola of the eye, photoreceptors and Müller cells with a unique morphology have been described, but little is known about their 3D structure and orientation. Considering that there is an angle-dependent change in the foveolar photoreceptor response for the same light beam, known as the Stiles Crawford Effect of the first kind (SCE I), which is still not fully understood, a detailed analysis of the anatomy of the foveolar cells might help to clarify this phenomenon. Methods Serial semithin and ultrathin sections, and focused ion beam (FIB) tomography were prepared from 32 foveolae from monkeys (Macaca fascicularis) and humans. Foveolae were also analyzed under the electron microscope. Serial sections and FIB analysis were then used to construct 3D models of central Müller and photoreceptor cells. In addition, we measured the transmission of collimated light under the light microscope at different angles after it had passed through human foveae from flat mounted isolated retinae. Results In monkeys, outer segments of central foveolar cones are twice as long as those from parafoveal cones and do not run completely parallel to the incident light. Unique Müller cells are present in the central foveolae (area of 200 µm in diameter) of humans and monkeys. Light entering the fovea center, which is composed only of cones and Müller cells, at an angle of 0° causes a very bright spot after passing through this area. However, when the angle of the light beam is changed to 10°, less light is measured after transpasssing through the retina, the foveolar center becomes darker and the SCE-like phenomenon is directly visible. Measurements of the intensities of light transmission through the central foveola for the incident angles 0 and 10° resemble the relative luminance efficiency for narrow light bundles as a function of the location where the beam enters the pupil as reported by Stiles and Crawford. The effect persisted after carefully brushing away the outer segments. Conclusion We show that unique cones and Müller cells with light fibre-like properties are present in the center of the fovea. These unique Müller cells cause an angle dependent, SCE-like drop in the intensity of light guided through the foveola. Outer segments from the foveolar cones of monkeys are not straight.

scholarly journals Is Pteropyrum a pathway to C4 evolution in Polygonaceae? An integrative approach to the taxonomy and anatomy of Pteropyrum (C3), an immediate relative of Calligonum (C4)

2019 ◽  
Vol 192 (2) ◽  
pp. 369-400 ◽  
Author(s):  
Moslem Doostmohammadi ◽  
Maryam Malekmohammadi ◽  
Morteza Djamali ◽  
Hossein Akhani
Keyword(s):  
Pollen Morphology ◽  
Water Storage ◽  
Integrative Approach ◽  
Herbarium Specimens ◽  
Similar Species ◽  
High Plasticity ◽  
Storage Tissue ◽  
Mesophyll Cells ◽  
Distribution Maps ◽  
Mesophyll Tissue

Abstract Pteropyrum is a small genus of Polygonaceae with four species from the arid regions of Iran and adjacent countries. Pteropyrum spp. are not precisely delimitated and are difficult to identify because of their high plasticity in morphological characters. Pteropyrum (C3) has a close affinity to Calligonum (C4) and is therefore a suitable case for C4 evolutionary studies. We investigated the morphology and micromorphology (including pollen morphology) of Pteropyrum and elucidated the phylogenetic relationships with Atraphaxis and Calligonum using nuclear ITS sequences. Characteristics of the photosynthetic tissues such as volume and number of layers of primary carbon assimilation tissues (PCA) and photosynthetic carbon reduction tissue (PCR) were studied. In addition, the leaf and cotyledon anatomical characters of Pteropyrum (C3), Atraphaxis (C3) and Calligonum (C4), and their δ 13C values were compared to look for evolutionary changes in assimilating organs. The molecular phylogenetic tree identifies two strongly supported clades in Pteropyrum and its close relationship with Calligonum, confirming previous studies. Some morphologically similar species belong to different clades, which is probably due to convergent evolution and homoplasy. Leaf anatomical studies show that Atraphaxis has a multilayered mesophyll tissue, whereas Calligonum has one-layered mesophyll cells. The volume and layer number of mesophyll tissue cells decreases, whereas water storage tissue area significantly increases from Atraphaxis to Pteropyrum and Calligonum. This phenomenon confirms previous studies in other lineages with C4 salsoloid anatomy that have evolved through increasing of water storage tissue and succulence of assimilating organs. In the taxonomic part of the paper, a key to identification of accepted taxa of Pteropyrum, description of species and distribution maps are presented based on numerous herbarium specimens and our own rich collections from the field. Four new species are described based on a combination of morphology of seedlings and mature plants, pollen morphology and molecular data. A subspecific classification is suggested to show morpho-geographical variation of Pteropyrum aucheri s.l.

Analytical Technique for Measuring Transmission of Light Through Milk Carton Materials

1983 ◽  
Vol 46 (4) ◽  
pp. 309-314 ◽  
Author(s):  
KURT H. NELSON ◽  
WILLIAM M. CATHCART
Keyword(s):  
Wall Thickness ◽  
Light Transmission ◽  
Incident Light ◽  
Visible Region ◽  
Analytical Technique ◽  
Yellow Orange

Light transmissions through milk carton paperboards, milk cartons, and blow-molded polyethylene containers were measured in the 350 to 800 nm region using a Cary 17D spectrophotometer equipped with a scattered transmission accessory. The paperboards had S-shaped transmission curves and were nearly opaque to wavelengths below 400 nm. Transmission at 800 nm averaged 5-3/4, 5-1/2, 4-1/2, 3, and 3% for the Eco Pak™, half-pint, quart, half-gallon, and gallon carton paperboards, respectively. Depending on wall thickness and wavelength of incident light, polyethylene containers had from 50 to 70% transmission. The effectiveness of different colored inks in reducing light transmission was compared using printed and unprinted areas of the paperboard cartons. Yellow, orange, gold, red, brown, and black inks opacified half-gallon cartons to wavelengths below 500 nm. Light transmission was reduced throughout the visible region by black, brown, and blue inks.

scholarly journals Spatial variability and temporal stability of water storage in a cultivated tropical soil

Bragantia ◽  
2010 ◽  
Vol 69 (suppl) ◽  
pp. 153-162 ◽  
Author(s):  
Antonio Carlos Andrade Gonçalves ◽  
Marcos Antonio Trintinalha ◽  
Marcos Vinicius Folegatti ◽  
Roberto Rezende ◽  
Cássio Antonio Tormena
Keyword(s):  
Water Content ◽  
Soil Water ◽  
High Efficiency ◽  
Temporal Stability ◽  
Water Storage ◽  
Soil Surface ◽  
Soil Water Storage ◽  
Soil Conditions ◽  
Content Uniformity ◽  
Water Application

Irrigated agricultural fields usually show variable crop water demand. If water application is done to match this spatially variable demand, the water use efficiency can be substantially improved. Soil water management by irrigation has been one of the most important factors to increase crop yield. To look for the economic viability of the process, the use of several inputs, particularly water, should be done with high efficiency levels. Historically, irrigation uniformity has been evaluated above the soil surface, in which applied water was the only factor to be taken into account. However, the crop will respond to soil water content uniformity, which can differ from the uniformity of water application. To evaluate temporal stability of spatial pattern of soil water storage (SWS), this work was done on a Brazilian clayed soil. Volumetric water content from soil surface to 0,30m depth, was measured by TDR in 80 points regularly spaced (3 x 3 m) on an experimental area cultivated with bean crop, irrigated by conventional sprinkling. The evaluations were done immediately before and after a water application by irrigation. Experimental semivariograms made from values obtained in the field showed that SWS distribution was spatially structured and strongly stable in time, being regulated mainly by intrinsic factors of the soil. In addition, obtained results showed that water application uniformity did not influence the spatial distribution pattern of SWS in these soil conditions.

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