Extraction, optical properties, and aging studies of natural pigments of various flower plants

In this paper, we reported the extraction process of five different flowering plants utilizing different dye extraction methods and solvents (ethanol and water) to choose the best dye removal process. The FTIR spectra revealed the presence of several clear functional groups for all five natural dyes. The analytical studies such as UV spectroscopy, column chromatography, and vacuum evaporation were performed to isolate the dyes from their solutions. The UV-Vis studies on the pigments of flower extracts indicated broad absorption peaks in the visible region including clear bandgaps. Among the studied pigments, Alternanthera ficoidea showed the lowest direct bandgap of 1.69 eV and an Urbach energy value of 6.33 meV. The dye extraction yield rate improvement was extended from 11.7 to 24.7% (water solvent) and 11.3–32.4% (ethanol solvent). Throughout the studies, it was observed that ethanol produced a better extraction for organic dyes than water as a solvent. Aging studies revealed that all the dyes at the room temperature showed better stability with minor changes in the observed optical parameters in oxygen-rich conditions; however, these parameters have shown significant variations at a 60 °C temperature

GENETIC DIVERGENCE OF JESSO-BALAM RICE (Oryza sativa L.) OF BANGLADESH

In total 27 genotypes of Jesso-Balam pure line rice germplasm were studied for fourteen morpho-physiological and four physico-chemical characters at Bangladesh Rice Research Institute, during T. Aman 2009 and T. Aman 2011 seasons. According to principal component scores, the two-dimensional scatter diagram (Z1-Z2) has apparently distributed the genotypes into seven clusters. According to Mahalanobis’ D2 statistic for the studied characters, the genotypes were clubbed into seven groups. The highest number of genotypes (6) were included in clusters I and III and the lowest two (2) in cluster V and VII. It was also revealed that no duplicate was existed among the genotypes. The intra-cluster distance was maximum (0.77) in cluster III and minimum (0.28) in cluster VII, while the maximum intercluster distance (28.37) was observed between the clusters III and IV and the minimum (2.49) between the clusters I and VII. The cluster V has produced the highest means for plant height (148.18 cm), straw yield per hill (39.97 g), panicle length (28.14 cm) and protein content (9.61%). But, the cluster IV has showed the highest means for seedling height (69.5 cm), flag and penultimate leaf area (1059.5 cm2), culm diameter (5.8 cm), filled grain number per panicle (3.64), grain length (8.63 mm) and 1000-grain weight (21.78 g), while the cluster VII had the highest means for grain yield per hill (31.27 g) and effective tiller number per hill (13.5) and the lowest mean for days to maturity (144). Therefore, the genotypes of cluster V need to be crossed with the genotypes of cluster IV or cluster VII, for developing new Balam rice with maximum other good characters. Finally, it could be concluded that the studied Jesso-Balam pure lines germplasm is a good source of valuable genes

Effect of Community Based Organization microcredit on livelihood improvement

The study was conducted to examine the effects of Community Based Organization (CBO) micro-credit program of Concern Worldwide on the livelihood improvement of beneficiaries in a selected area of Mymensingh district. In the study, 50 respondents were purposively selected of which 30, 12 and 8 were engaged in small trading, saloon and rickshaw pulling respectively. Tabular and statistical analyses were applied for achieving the objectives. All of the factors to measure the socio-economic condition such as awareness, family income, assets, clothing, etc has been changed. It was also found that the women participation in the household decision making increases. Repayment performance of CBO micro-credit program was highly satisfactory. Respondent’s income and loan receipt amount were positively contributed to loan repayment, whereas respondent’s age, education, family size and forced saving negatively affected the same. Ninety four per cent of the respondents mainly repaid their loan on time with the hope of getting loan in future. Overall, the CBO micro-credit program was found to have significant positive effects on livelihood improvement

Impact of ionizing radiation doses on nanocrystalline TiO2 layer in DSSC’s photoanode film

In dye-sensitized solar cell (DSSC) properties of nanocrystalline oxide layer of photoanode may changes when exposed to ionization radiation environment which may leads to change the cell performance. In this study, 10 µm thick TiO2 (Degussa-P25) was deposited as a photoanode film on microscopic glass slide with the doctor-blade coating. The deposited film was subjected to different gamma (γ) radiation doses (0–20 kGy) to study the effect of ionizing radiation on morphological, structural, optical and compositional characteristics of the film. At 10 kGy dose, dislocation density (DD), strain, crystallites per unit surface area (CPSA), specific surface area (SSA) of anatase phase (1 0 1) of the film were decreased abruptly, conversely, crystal size and morphology index (MI) were increased at the same radiation dose slowly. UV-Vis-NIR spectroscopy results showed that in irradiated photoanode film the light transmittance and absorption depth were decreased, whereas, absorption and absorption coefficient were increased beyond the visible wavelength. The optical band gap of the irradiated film was increased by 12.5% when the gamma radiation dose increased from 0 kGy to 20 kGy. Thus, the irradiation induced changes in physio-chemical properties of nanocrystalline photoanode film may affect the DSSC cell performance. Keywords: Effect of ionizing radiation, Structural properties, Optical properties, DSSC photoanode film, Nanocrystalline TiO2, Dye-sensitized solar cel

Inter-operative Trajectory Registration for Endoluminal Video Synchronization: Application to Biopsy Site Re-localization

International audienceThe screening of oesophageal adenocarcinoma involves obtaining biopsies at different regions along the oesophagus. The localization and tracking of these biopsy sites inter-operatively poses a significant challenge for providing targeted treatments. This paper presents a novel framework for providing a guided navigation to the gastro-intestinal specialist for accurate re-positioning of the endoscope at previously targeted sites. Firstly, we explain our approach for the application of electromagnetic tracking in acheiving this objective. Then, we show on three in-vivo porcine interventions that our system can provide accurate guidance information, which was qualitatively evaluated by five experts

A holistic approach to optical characterizations of vacuum deposited Cu2ZnSnS4 thin film coatings for solar absorbing layers

This article aimed at making a good absorber layer of Cu2ZnSnS4 thin film coatings deposited onto glass substrates via spin coating technique with different rotational speeds. Three sets of Cu2ZnSnS4 thin film coatings were prepared at rotations of 3000, 3500, and 4000/min. The thickness of the thin film coatings was measured using a surface profilometer, and the coating thickness shows good rpm dependence i.e., the thickness of the coatings decreased with increasing rpm. The thicknesses of the coatings were in the nanometer (nm) range for all samples. The structural, morphological, and optical properties of the as coated thin films were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and ultraviolet–visible (UV–Vis) absorption spectroscopy. The XRD pattern confirmed the body-centered tetragonal lattice structure with Kesterite Cu2ZnSnS4 phase having good crystallinity. The average crystallite size increases while lattice strain, dislocation density, and crystallite number are decreased with increasing thicknesses of the Cu2ZnSnS4 coatings. SEM micrographs represent the homogeneous, agglomerated surface without any cracks and pores. The average optical band-gap of the coatings was found to be 1.5 eV. Dielectric parameters such as refractive index, high-frequency dielectric constant, and static dielectric constant were declined with increasing thickness of Cu2ZnSnS4 thin film coatings. These characteristics would allow the Cu2ZnSnS4 thin film coatings to be suitable for an absorber layer used in photovoltaic devices

Magnetic, dielectric and electrical properties of lithium-magnesium ferrites

A series of polycrystalline spinel type ferrites with composition Li x Mg0.5Ni0.5– 2 x Fe2+ x O4, where x = 0.00 to 0.25 in steps of 0.05, have been prepared by standard double sintering method sintered at temperature 1200 °C in air for 6 hours. In this work, investigations have been carried out by the measurements of X-ray diffraction (XRD), Curie temperature, permeability, loss tangent, Q-factor, dielectric constant and ac electrical resistivity of the samples. Some measurements have been done at room temperature while other measurements have been done as a function of temperature and as a function of frequency in the range from 1 kHz to 500 kHz. Curie temperature, the real part of initial permeability (μ i ), the loss tangent (tan δ), and the Q-factor have been found to be decreased with the increase of Ni-content of Li x Mg0.5Ni0.5– 2 x Fe2+ x O4 ferrites. The frequency characteristic of dielectric constant and AC resistivity decreases with the increase in frequency and increases with the increase in Ni-content