MORPHOLOGY AND COMPOSITION OF THE INTERFACE BOUNDARY OF SODIUM CHLORIDE SINGLE CRYSTALS WITH LEAD

Методами электронной микроскопии и рентгеноспектрального анализа исследована межфазная граница раздела жидкого свинца с хлоридом натрия после охлаждения и разрыва контакта. На поверхностях разрыва образцов обнаружено накопление поверхностно-активных примесей, содержащихся как объеме свинца, так и в хлориде натрия. Как показывают результаты рентгеноспектрального анализа, содержание примесей на поверхности подложки хлорида натрия превышает объемное содержание на несколько порядков. На поверхности свинца также наблюдается значительное накопление примесей кремния и индия. В исследованных образцах наблюдается анизотропия растекания жидкого свинца по поверхности монокристаллов хлорида натрия. Линия разрыва, затвердевшей капли свинца с монокристаллической поверхностью хлорида натрия ориентации (110), заметно отклоняются от круга. Кроме того, на электронно-микроскопическом изображении межфазной поверхности свинца после отрыва от подложки хлорида натрия ориентации (100), наблюдаются участки в виде «сигары», в которых обнаружено накопление примесей. Данные участки имеют ориентации, совпадающие с кристаллографическим направлением подложки. The interface between liquid lead and sodium chloride after cooling and breaking the contact was investigated by the electron microscopy and X-ray spectral analysis. Accumulation of surface-active impurities, contained both in the bulk of lead and in sodium chloride was found on the fracture surface of the samples. As shown by the results of the X-ray diffraction analysis, the content of impurities on the surface of the sodium chloride substrate exceeds the bulk content by several orders of magnitude. A significant accumulation of silicon and indium impurities is also observed on the lead surface. Anisotropy of spreading of liquid lead over the surface of sodium chloride monocrystals is observed in the studied samples. The separation line of a solidified lead droplet on the surface of sodium chloride with orientation (110) deviates noticeably from a circle. In addition, on the electron microscopic image of the lead interface after detachment from the substrate of sodium chloride of orientation (110), there are areas in the form of a «cigar», in which the accumulation of impurities was detected. The orientation of these regions coincides with the crystallographic direction of the substrate.

Synthesis, spectral and sol-gel behavior of mixed ligand complexes of titanium(IV) with oxygen, nitrogen and sulfur donor ligands

A new route to synthesize nano-sized Ti(IV) mixed ligand complexes have been investigated by the reaction of titanium(IV) chloride with ammonium salts of dithiophosphate and 3(2'-hydroxyphenyl)-5-(4-substituted phenyl) pyrazolines. The resultant complex is then treated with H2S gas to get sulfur bridged dimer of Ti(IV) complex, a precursor of TiS2. The morphology of the complexes was studied by employing XRD which shows that all the complexes are amorphous solid. Molecular weight measurements, elemental analysis in conjugation with spectroscopic (IR, 1H NMR, 13C NMR and 31P NMR) studies revealed the dimeric nature of the complexes in which pyrazoline and dithiophosphate are bidentate. Scanning electron microscopic image and XRD indicate that the particles are in the nano range (50 nm). Putting all the facts together, coordination number six is proposed for titanium with octahedral geometry. KEY WORDS: Titanium(IV), Dithiophosphate, Pyrazoline, Nano-sized, Sol-gel, Mixed ligand complexes Bull. Chem. Soc. Ethiop. 2021, 35(1), 61-76. DOI: https://dx.doi.org/10.4314/bcse.v35i1.5

Microscopy images segmentation algorithm based on shearlet neural network

Microscopic images are becoming important and need to be studied to know the details and how-to quantitatively evaluate decellularization. Most of the existing research focuses on deep learning-based techniques that lack simplification for decellularization. A new computational method for the segmentation microscopy images based on the shearlet neural network (SNN) has been introduced. The proposal is to link the concept of shearlets transform and neural networks into a single unit. The method contains a feed-forward neural network and uses a single hidden layer. The activation functions are depending on the standard shearlet transform. The proposed SNN is a powerful technology for segmenting an electron microscopic image that is trained without relying on the pre-information of the data. The shearlet neural networks capture the features of full accuracy and contextual information, respectively. The expected value for specific inputs is estimated by learning the functional configuration of a network for the sequence of observed value. Experimental results on the segmentation of two-dimensional microscopy images are promising and confirm the benefits of the proposed approach. Lastly, we investigate on a challenging datasets ISBI 2012 that our method (SNN) achieves superior outcomes when compared to classical and deep learning-based methods.

Adsorption of selected azo dyes from an aqueous solution by activated carbon derived from Monotheca buxifolia waste seeds

In this study, activated carbon derived from Monotheca buxifolia waste seeds was used for the adsorptive removal of a number of selected azo dyes such as Eriochrome Black T (EBT), Remazol brilliant blue (RBB), Remazol yellow (RY) and Remazol brilliant orange (RBO) from an aqueous solution by changing the initial dye concentration, adsorbent dosage, solution pH, contact time and temperature. A Fourier transform infrared spectroscopic analysis of the activated carbon showed the existence of hydroxyls, methyl, methylene, carbonyls, alkane and alkenes groups while the scanning electron microscopic image displayed the gradual formation of cavities and open pores on the surface. The results showed that as the amount of the adsorbent and the shaking time were increased, the removal percentage of the dye increased accordingly. Higher adsorption percentages were observed at a lower dye concentration and temperature in an acidic media at a pH range (1–5). The investigated data were evaluated with the Langmuir and Freundlich adsorption models. The maximum adsorption capacities obtained from the Langmuir model were 112.36, 96.34, 97.65 and 90.91 mg/g for EBT, RBB, RY and RBO, respectively. The results indicated that the electrostatic interaction was the main cause of the adsorption of these anionic azo dyes on the surface of the activated carbon.

The Neural Basis for a Persistent Internal State in Drosophila Females

Sustained changes in mood or action require persistent changes in neural activity, but it has been difficult to identify and characterize the neural circuit mechanisms that underlie persistent activity and contribute to long-lasting changes in behavior. Here, we focus on changes in the behavioral state of Drosophila females that persist for minutes following optogenetic activation of a single class of central brain neurons termed pC1. We find that female pC1 neurons drive a variety of persistent behaviors in the presence of males, including increased receptivity, shoving, and chasing. By reconstructing cells in a volume electron microscopic image of the female brain, we classify 7 different pC1 cell types and, using cell type specific driver lines, determine that one of these, pC1-Alpha, is responsible for driving persistent female shoving and chasing. Using calcium imaging, we locate sites of minutes-long persistent neural activity in the brain, which include pC1 neurons themselves. Finally, we exhaustively reconstruct all synaptic partners of a single pC1-Alpha neuron, and find recurrent connectivity that could support the persistent neural activity. Our work thus links minutes-long persistent changes in behavior with persistent neural activity and recurrent circuit architecture in the female brain.

Nanotone spatial dissipative structures with rotational curving of the grid around three mutually perpendicular directions

Transmission electron microscopy and microdiffraction have been used to investigate nanothin spatial dissipative structures (SDS) obtained by thermogradient processing of an amorphous selenium film by one-sided heating of its lower surface at T = 413 K. It has been established that the obtained nanothin SDS of hexagonal selenium possess a specific curved habit and a nonlinear fan-shaped system of bending contours in their electron-microscopic image; the lattice of nanothin SDS undergoes an elastic-plastic rotational curvature around three mutually perpendicular directions; the lattice rotation angles of nanothin SDS hexagonal selenium reach: around [001], 25, around the direction perpendicular to [001] and lying in the plane of the amorphous film 32, around the direction perpendicular to the first two and not lying in the plane of the amorphous film 35.

Modified coconut coir to remove hexavalent chromium from aqueous solution

Hexavalent chromium (Cr(VI)) was removed from aqueous solution by adsorption using chemically modified lignin-rich low-cost coconut coir. The equilibrium time, adsorption isotherm and adsorption kinetics at certain conditions such as pH, particle size and the initial concentration of adsorbate were investigated. The coconut coir was modified by sodium chlorite for adsorption studies. The scanning electron microscopic image depicted the morphology of SCM-CC of different particle sizes whereas the elemental composition of this sort of bioadsorbent was determined by using energy dispersive spectroscopic data. Fourier transform infrared (FTIR) spectrometry analysis indicated that the carbonyl (C=O) groups and hydroxy (O–H) groups from the lignin structure in coconut coir may be involved in the mechanism of Cr(VI) adsorption. The maximum Cr(VI) adsorption capacity of sodium chlorite modified coconut coir (SCM-CC) was found to be 28.03 mg Cr(VI) g-1 SCM-CC at pH 2.00 for the particle size of 75-100 μm with the dose of 7.5 g/L. The equilibrium was established within three hours resulting in the maximum removal (99.92%) of chromium. Freundlich isotherm was better fitted than Langmuir isotherm at pH 2.00 on the basis of the regression coefficient (R2). The kinetic data well-fitted with Ho’s pseudo second order kinetics. The SCM-CC can be treated as an excellent adsorbent for the remediation of chromium toxicity. Bangladesh J. Sci. Ind. Res.54(1), 89-98, 2019

An Efficient Adaptive Algorithm for Electron Microscopic Image Enhancement and Feature Extraction

In this article, a block-based adaptive contrast enhancement algorithm has been proposed, which uses a modified sigmoid function for the enhancement and features extraction of electron microscopic images. The algorithm is based on a modified sigmoid function that adapts according to the input microscopic image statistics. For feature extraction, the contrast of the image is very important and authentic property by which this article enhances the visual quality of the image. In this work, for better contrast enhancement of image, a block based on input value, combined with a modified sigmoid function that is used as contrast enhancer provides better EMF values for a smaller block size. It provides localized contrast enhancement effects adaptively which is not possible using other existing techniques. Simulation and experimental results demonstrate that the proposed technique gives better results compared to other existing techniques when applied to electron microscopic images. After the enhancement of microscopic images of actinomycetes, various important features are shown, like coil or spiral, long filament, spore and rod shape structures. The proposed algorithm works efficiently for different dark and bright microscopic images.