Biomass Compositional Analysis for Energy Applications

Author(s):  
Bonnie R. Hames
Author(s):  
A. Olsen ◽  
J.C.H. Spence ◽  
P. Petroff

Since the point resolution of the JEOL 200CX electron microscope is up = 2.6Å it is not possible to obtain a true structure image of any of the III-V or elemental semiconductors with this machine. Since the information resolution limit set by electronic instability (1) u0 = (2/πλΔ)½ = 1.4Å for Δ = 50Å, it is however possible to obtain, by choice of focus and thickness, clear lattice images both resembling (see figure 2(b)), and not resembling, the true crystal structure (see (2) for an example of a Fourier image which is structurally incorrect). The crucial difficulty in using the information between Up and u0 is the fractional accuracy with which Af and Cs must be determined, and these accuracies Δff/4Δf = (2λu2Δf)-1 and ΔCS/CS = (λ3u4Cs)-1 (for a π/4 phase change, Δff the Fourier image period) are strongly dependent on spatial frequency u. Note that ΔCs(up)/Cs ≈ 10%, independent of CS and λ. Note also that the number n of identical high contrast spurious Fourier images within the depth of field Δz = (αu)-1 (α beam divergence) decreases with increasing high voltage, since n = 2Δz/Δff = θ/α = λu/α (θ the scattering angle). Thus image matching becomes easier in semiconductors at higher voltage because there are fewer high contrast identical images in any focal series.


Author(s):  
John B. Vander Sande ◽  
Thomas F. Kelly ◽  
Douglas Imeson

In the scanning transmission electron microscope (STEM) a fine probe of electrons is scanned across the thin specimen, or the probe is stationarily placed on a volume of interest, and various products of the electron-specimen interaction are then collected and used for image formation or microanalysis. The microanalysis modes usually employed in STEM include, but are not restricted to, energy dispersive X-ray analysis, electron energy loss spectroscopy, and microdiffraction.


2015 ◽  
Vol 7 (1) ◽  
pp. 271-276
Author(s):  
MA Zubair ◽  
MA Haque ◽  
MM Sultana ◽  
S Akter

16th February 2015. Due to a number of missing tables and figures, this article (DOI: http://dx.doi.org/10.3329/jesnr.v7i1.22182) was withdrawn from Vol.7(1) and has been republished with corrections in Vol.7(2) pp.185-190 (DOI: http://dx.doi.org/10.3329/jesnr.v7i2.22230). The Editor  


Author(s):  
B. Khadambari ◽  
S. S. Bhattacharya

Solar has become one of the fastest growing renewable energy sources. With the push towards sustainability it is an excellent solution to resolve the issue of our diminishing finite resources. Alternative photovoltaic systems are of much importance to utilize solar energy efficiently. The Cu-chalcopyrite compounds CuInS2 and CuInSe2 and their alloys provide absorber material of high absorption coefficients of the order of 105 cm-1. Cu2ZnSnS4 (CZTS) is more promising material for photovoltaic applications as Zn and Sn are abundant materials of earth’s crust. Further, the preparation of CZTS-ink facilitates the production of flexible solar cells. The device can be designed with Al doped ZnO as the front contact, n-type window layer (e.g. intrinsic ZnO); an n-type thin film buffer layer (e.g. CdS) and a p-type CZTS absorber layer with Molybdenum (Mo) substrate as back contact. In this study, CZTS films were synthesized by a non-vaccum solvent based process technique from a molecular-ink using a non toxic eco-friendly solvent dimethyl sulfoxide (DMSO). The deposited CZTS films were optimized and characterized by XRD, UV-visible spectroscopy and SEM.


Author(s):  
Dmitri Vinnikov ◽  
Oleksandr Husev ◽  
Indrek Roasto

Lossless Dynamic Models of the Quasi-Z-Source Converter FamilyThis paper is devoted to the quasi-Z-source (qZS) converter family. Recently, the qZS-converters have attracted attention because of their specific properties of voltage boost and buck functions with a single switching stage, which could be especially beneficial in renewable energy applications. As main representatives of the qZS-converter family, the traditional quasi-Z-source inverter as well as two novel extended boost quasi-Z-source inverters are discussed. Lossless dynamic models of these topologies are presented and analyzed.


2020 ◽  
Author(s):  
KJ Nunan ◽  
Ian Sims ◽  
A Bacic ◽  
SP Robinson ◽  
GB Fincher

Cell walls have been isolated from the mesocarp of mature grape (Vitis vinifera L.) berries. Tissue homogenates were suspended in 80% (v/v) ethanol to minimise the loss of water-soluble wall components and wet-sieved on nylon mesh to remove cytoplasmic material. The cell wall fragments retained on the sieve were subsequently treated with buffered phenol at pH 7.0, to inactivate any wall-bound enzymes and to dislodge small amounts of cytoplasmic proteins that adhered to the walls. Finally, the wall preparation was washed with chloroform/methanol (1:1, v/v) to remove lipids and dried by solvent exchange. Scanning electron microscopy showed that the wall preparation was essentially free of vascular tissue and adventitious protein of cytoplasmic origin. Compositional analysis showed that the walls consisted of approximately 90% by weight of polysaccharide and less than 10% protein. The protein component of the walls was shown to be rich in arginine and hydroxyproline residues. Cellulose and polygalacturonans were the major constituents, and each accounted for 30-40% by weight of the polysaccharide component of the walls. Substantial varietal differences were observed in the relative abundance of these two polysaccharides. Xyloglucans constituted approximately 10% of the polysaccharide fraction and the remainder was made up of smaller amounts of mannans, heteroxylans, arabinans and galactans.


1999 ◽  
Vol 16 (4) ◽  
pp. 175-180 ◽  
Author(s):  
Virginie M. Vaubert ◽  
Mark A. Janney ◽  
David P. Stinton

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