Studying Optical Characteristics of Diffused Light Reflecting from Naturally Senescing Leaves of Deciduous Trees

2020 ◽  
pp. 72-82
Author(s):  
Yu.V. Mamelin ◽  
G.F. Kopytov ◽  
V.Yu. Buzko
Keyword(s):  
Narrow Band ◽  
Spectral Characteristics ◽  
Vegetation Indices ◽  
Optical Characteristics ◽  
Light Reflection ◽  
Deciduous Trees ◽  
Biological Objects ◽  
Light Reflectance ◽  
Diffused Light ◽  
First Time

Study object included leaves of deciduous trees in the Krasnodar Territory at different stages of senescing visually manifested in their color alteration. Study subject was the optical characteristics of light diffused reflection from green, yellow-green and yellow leaves of deciduous trees in the Krasnodar Territory during the autumn season. Work objective lies in identifying the possibility to establish differences between green leaves of deciduous trees, and yellow-green and yellow leaves of deciduous trees using the terrain multispectral and hyperspectral sounding methods, as well as collecting information on spectral characteristics of the diffused light being reflected from various biological objects. Results of quantitative and qualitative analysis of data obtained through the diffused light reflectance spectroscopy from leaves of deciduous trees are presented. Narrow-band vegetation indices mNDVI705, mSR705, CRI1, SIPI and PSRI were used in quantitative analysis of data on the diffused light reflection spectra obtained from green, yellow-green and yellow leaves of deciduous trees. It was revealed that the use of narrow-band vegetation indices in the remote sensing algorithms using multi- and hyperspectral cameras makes it possible to rather accurately distinguish leaves at different stages of senescing. Optical characteristics of diffused light reflection from green, yellow-green and yellow leaves of deciduous trees, which are typical species of trees in urban and rural plantings in the Krasnodar Territory, are described for the first time

scholarly journals Дискриминация хвойных и лиственных листьев деревьев и кустарников от декоративно-искусственных материалов методом оптической спектроскопии диффузного отражения света

2020 ◽  
Vol 128 (2) ◽  
pp. 290
Author(s):  
Ю.В. Мамелин ◽  
Г.Ф. Копытов ◽  
В.Ю. Бузько
Keyword(s):  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Vegetation Indices ◽  
Reflectance Spectroscopy ◽  
Light Reflection ◽  
Diffuse Light ◽  
Artificial Materials ◽  
Krasnodar Region ◽  
First Time ◽  
Trees And Shrubs

The article was the first time investigation the spectra of diffuse light reflection from coniferous and deciduous green leaves of trees and shrubs that growing in the Krasnodar region territory. The obtained spectral data were compared with the spectra of diffuse light reflection from green synthetic decorative and artificial leaves and various camouflage materials. The use of vegetation indices of "greenness" to discriminate coniferous and deciduous leaves of trees and shrubs from decorative and artificial materials by optical diffuse reflectance spectroscopy was proposed.

scholarly journals Estimating and Monitoring Land Surface Phenology in Rangelands: A Review of Progress and Challenges

2021 ◽  
Vol 13 (11) ◽  
pp. 2060
Author(s):  
Trylee Nyasha Matongera ◽  
Onisimo Mutanga ◽  
Mbulisi Sibanda ◽  
John Odindi
Keyword(s):  
Land Surface ◽  
Vegetation Index ◽  
Critical Role ◽  
Spectral Characteristics ◽  
Vegetation Indices ◽  
Machine Learning Algorithms ◽  
Special Focus ◽  
Land Surface Phenology ◽  
Spectral Vegetation Indices ◽  
Satellite Sensors

Land surface phenology (LSP) has been extensively explored from global archives of satellite observations to track and monitor the seasonality of rangeland ecosystems in response to climate change. Long term monitoring of LSP provides large potential for the evaluation of interactions and feedbacks between climate and vegetation. With a special focus on the rangeland ecosystems, the paper reviews the progress, challenges and emerging opportunities in LSP while identifying possible gaps that could be explored in future. Specifically, the paper traces the evolution of satellite sensors and interrogates their properties as well as the associated indices and algorithms in estimating and monitoring LSP in productive rangelands. Findings from the literature revealed that the spectral characteristics of the early satellite sensors such as Landsat, AVHRR and MODIS played a critical role in the development of spectral vegetation indices that have been widely used in LSP applications. The normalized difference vegetation index (NDVI) pioneered LSP investigations, and most other spectral vegetation indices were primarily developed to address the weaknesses and shortcomings of the NDVI. New indices continue to be developed based on recent sensors such as Sentinel-2 that are characterized by unique spectral signatures and fine spatial resolutions, and their successful usage is catalyzed with the development of cutting-edge algorithms for modeling the LSP profiles. In this regard, the paper has documented several LSP algorithms that are designed to provide data smoothing, gap filling and LSP metrics retrieval methods in a single environment. In the future, the development of machine learning algorithms that can effectively model and characterize the phenological cycles of vegetation would help to unlock the value of LSP information in the rangeland monitoring and management process. Precisely, deep learning presents an opportunity to further develop robust software packages such as the decomposition and analysis of time series (DATimeS) with the abundance of data processing tools and techniques that can be used to better characterize the phenological cycles of vegetation in rangeland ecosystems.

scholarly journals Statistical assessment of ecological invariants of plant cover and the possibility of estimating invariants in the taxonomy of plants

2021 ◽  
Vol 20 (1) ◽  
pp. 401-403
Author(s):  
B. I. Semkin ◽  
L. I. Varchenko
Keyword(s):  
Statistical Methods ◽  
Plant Cover ◽  
Leningrad Region ◽  
Statistical Assessment ◽  
Biological Objects ◽  
First Time

In this work, for the first time, ecological invariants for the dry polydominant cereal-forb meadow of theKarelian Isthmus of the Leningrad region and taxonomic invariants of three species of Heracleum L. are determined. It isproposed to use the developed statistical methods for evaluating invariants to differentiate biological objects at all levels ofbiota: molecular, subcellular, cellular, organismic, population, coenotic and ecological.

scholarly journals DISTORTIONLESS SIGNALS TRANSFER THROUGH A WIRE MEDIA METASTRUCTURE

2018 ◽  
Vol 8 (1) ◽  
pp. 44-47 ◽  
Author(s):  
Dmytro Vovchuk ◽  
Serhii Haliuk ◽  
Leonid Politanskyy
Keyword(s):  
Electromagnetic Waves ◽  
Spectral Characteristics ◽  
Wide Frequency Range ◽  
Power Transfer ◽  
Fabry Perot ◽  
Signal Distortions ◽  
Metallic Wires ◽  
The Wire ◽  
Wire Media ◽  
First Time

In the paper the development of the components of communication means is considered based on the wire metastructures. This approach is novel and quite promising due to the metamaterials provides new opportunities for the radio engineering devices such as antennas, absorbers etc. First of all it makes possible decreasing of the dimensions of devices while the characteristics stay the same or better. Here the artificially created metastructure that consists of parallel metallic wires and characterizes by a negative electric permittivity was investigated. The possibility of broadband power transfer of electromagnetic waves was demonstrated. Also, at first time, the investigation of possible signal distortions due to wave propagation through the wire medium (WM) slab was performed via analyzing of spectral characteristics. The obtained results allow applying of WM to power transfer in wide frequency range (not only at frequencies of Fabry-Perot resonant) and enhancement of weak source propagation as well as to antennas constructions due to the absence of signal distortions. One of the promising applications of such structures is the possibility of realizing of flexible screens with nanometer thickness and high resolution.

Micromorphological studies of leaf epidermal features in populations of maples (Acer L.) from Iran

Phytotaxa ◽  
2017 ◽  
Vol 299 (1) ◽  
pp. 36
Author(s):  
MOJGANSADAT MOHTASHAMIAN ◽  
FARIDEH ATTAR ◽  
KAVEH KAVOUSI ◽  
ALI MASOUDI-NEJAD
Keyword(s):  
Native Species ◽  
Deciduous Trees ◽  
Epicuticular Waxes ◽  
Abaxial Surface ◽  
Sem Images ◽  
Qualitative Variables ◽  
Epidermal Features ◽  
Parametric Analyses ◽  
First Time

As the largest genus of broad leaved deciduous trees, Acer L. contains about 126 species distributed in the temperate regions of the Northern Hemisphere. With eight native species in Iran, maples are among the most important tree species in the country. Micromorphological traits of 39 populations of Iranian native species indicated the value of leaf epidermal characteristics in identification and classification of maples. A number of epidermal morphological features of the abaxial surface were investigated using LM and SEM images. The occurrence of stomata in clusters is reported for the first time in Acer. The shape of the epidermal cells, anticlinal cell wall patterns, type of indumentum, and epicuticular waxes were the most significant variables in this study. The ability of quantitative and qualitative variables in segregating the studied taxa was evaluated by statistical methods, including PCA, MCA and Non-parametric analyses.

scholarly journals New Poly(Propylene Imine) Dendrimer Modified with Acridine and Its Cu(II) Complex: Synthesis, Characterization and Antimicrobial Activity

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3020 ◽  
Author(s):  
Paula Bosch ◽  
Desislava Staneva ◽  
Evgenia Vasileva-Tonkova ◽  
Petar Grozdanov ◽  
Ivanka Nikolova ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Copper Ions ◽  
Spectral Characteristics ◽  
Dilution Method ◽  
Pathogenic Microorganisms ◽  
Paramagnetic Resonance ◽  
Poly Propylene ◽  
New Compounds ◽  
First Time

A second-generation poly(propylene imine) dendrimer modified with acridine and its Cu(II) complex have been synthesized for the first time. It has been found that two copper ions form complexes with the nitrogen atoms of the dendrimeric core by coordinate bonds. The new compounds have been characterized by nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), fourier-transform infrared spectroscopy (FTIR) and fluorescence spectroscopy. The spectral characteristics of the modified dendrimer have been measured in different organic solvents, and a negative fluorescence solvatochromism has been observed. The antimicrobial activity of the dendrimers has been tested against model pathogenic microorganisms in agar and by broth dilution method. The cotton fabric treated with both dendrimers has been evaluated towards pathogenic microorganisms. The obtained modified cotton fabrics have been shown to hamper bacterial growth and to prevent biofilm formation. Dendrimer cytotoxicity has been investigated in vitro in the model HEp-2 cell line.

Narrow band imaging in the diagnosis of bladder schistosomiasis

2020 ◽  
Vol 13 (4) ◽  
pp. e233929
Author(s):  
Joachim Jimie ◽  
Margaret Lyttle
Keyword(s):  
White Light ◽  
Narrow Band ◽  
Narrow Band Imaging ◽  
Urinary Schistosomiasis ◽  
Detailed Evaluation ◽  
Characteristic Features ◽  
First Time ◽  
Urine Microscopy ◽  
White Light Imaging ◽  
Multiple Episodes

A 23-year-old man presented to us with multiple episodes of visible haematuria associated with dysuria, but no other symptoms suggestive of infection. His physical examination was completely unremarkable. On detailed evaluation of history, it was noted that he was treated for urinary schistosomiasis as a child in Sudan. A diagnostic flexible cystoscopy, with both white light and narrow band imaging (NBI), was done among other tests as a further diagnostic tool to investigate possible causes. This revealed the characteristic features of bladder schistosomiasis. Urine microscopy for Schistosoma haematobium eggs was negative, and this could have caused the diagnosis to be missed. He was treated with praziquantel for chronic bladder schistosomiasis. This is the first time that the use of NBI as an adjunct to white light imaging in the diagnosis of bladder schistosomiasis has been reported.

scholarly journals Channeling and radiation experiments at SLAC

2019 ◽  
Vol 34 (34) ◽  
pp. 1943006
Author(s):  
U. Wienands ◽  
S. Gessner ◽  
M. J. Hogan ◽  
T. Markiewicz ◽  
T. Smith ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Beam Energy ◽  
Narrow Band ◽  
Test Facility ◽  
Test Beam ◽  
High Beam ◽  
Silicon Crystals ◽  
Volume Reflection ◽  
Series Of Experiments ◽  
First Time

Since 2014, a SLAC-Aarhus-Ferrara-CalPoly collaboration augmented by members of ANL and MIT has performed electron and positron channeling experiments using bent silicon crystals at the SLAC End Station A Test Beam as well as the FACET accelerator test facility. These experiments have revealed a remarkable channeling efficiency of about 24% under our conditions. Volume reflection is even more efficient with almost the whole beam taking part in the reflection process. A positron experiment demonstrated quasi-channeling oscillations for the first time at high beam energy. In our most recent experiment we measured the spectrum of gamma radiation for crystal orientations covering channeling and volume reflection. This series of experiments supports the development of more advanced crystalline devices capable e.g. of producing narrow-band gamma rays with electron beams or studying the interaction of the electrons with the wakefields generated in the crystal at high beam intensity.

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