Biofuel Production from Waste Cooking Oils and its Physicochemical Properties in Comparison to Petrodiesel

Haphazard mining and consumption of fossil fuels have reduced petroleum reserves causing fossil fuel depletion and environmental degradation; thus, reflecting the need for the cheaper, renewable and eco-friendly alternative source of petroleum to meet the fuel demand. A million liters of edible oil used for cooking foods and date expired oils from oil manufacturers are discarded into sewage. This study primarily intends to study the feasibility of biodiesel production using such waste oils. In this work, biodiesel was prepared from waste cooking oils by a process called transesterification with NaOH as a catalyst. Our results showed that methyl ester (biodiesel) (92.67±0.90%), soap materials (1.33±0.224%), and glycerol (6±0.68%) were obtained after the transesterification of waste cooking oil. The physicochemical properties of biodiesel such as density, viscosity, volatility, surface tension, and flashpoint were analyzed, which were found to be 0.862±0.006 g/cm3, 2.23±0.021 cP, 0.327×10-3±4.5×10-6 g/s, 32.03±0.138 dyne/cm, 169.67±0.810°C, respectively. These properties were compared with that of commercial diesel as well as with the values specified by the American Society for Testing and Materials (ASTM) D6751. The density and the surface tension of the biodiesel were found similar to that of petrodiesel but its volatility was 3 times lower. Fourier-transform infrared spectroscopy (FTIR) spectra of the biodiesel showed methyl ester functional group at 1436 cm-1. Based on the cost of the materials used for production, the cost of biodiesel was estimated to be about 81 Nepalese rupees (0.67 USD) per liter. The properties of biodiesel also met the standard values of ASTM D6751. These findings indicate that waste oil is one of the feasible biodiesel sources and it can be used as a suitable alternative to petrodiesel

Variation in grain zinc and iron concentrations, grain yield and associated traits of biofortified bread wheat genotypes in Nepal

Wheat (Triticum aestivum L.) is one of the major staples in Nepal providing the bulk of food calories and at least 30% of Fe and Zn intake and 20% of dietary energy and protein consumption; thus, it is essential to improve its nutritional quality. To select high-yielding genotypes with elevated grain zinc and iron concentration, the sixth, seventh, eighth, and ninth HarvestPlus Yield Trials (HPYTs) were conducted across diverse locations in Nepal for four consecutive years: 2015–16, 2016–17, 2017–18, and 2018–19, using 47 biofortified and 3 non-biofortified CIMMYT-bred, bread wheat genotypes: Baj#1, Kachu#1, and WK1204 (local check). Genotypic and spatial variations were found in agro-morphological traits; grain yield and its components; and the grain zinc and iron concentration of tested genotypes. Grain zinc concentration was highest in Khumaltar and lowest in Kabre. Likewise, grain iron concentration was highest in Doti and lowest in Surkhet. Most of the biofortified genotypes were superior for grain yield and for grain zinc and iron concentration to the non-biofortified checks. Combined analyses across environments showed moderate to high heritability for both Zn (0.48–0.81) and Fe (0.46–0.79) except a low heritability for Fe observed for 7th HPYT (0.15). Grain yield was positively correlated with the number of tillers per m2, while negatively correlated with days to heading and maturity, grain iron, grain weight per spike, and thousand grain weight. The grain zinc and iron concentration were positively correlated, suggesting that the simultaneous improvement of both micronutrients is possible through wheat breeding. Extensive testing of CIMMYT derived high Zn wheat lines in Nepal led to the release of five biofortified wheat varieties in 2020 with superior yield, better disease resistance, and 30–40% increased grain Zn and adaptable to a range of wheat growing regions in the country – from the hotter lowland, or Terai, regions to the dry mid- and high-elevation areas

INVESTIGATIONS OF THE PHOTOPHYSICAL PROPERTIES OF FLUORESCENT PROTEINS AND THEIR IMPLICATIONS FOR ANALYSIS OF FÖRSTER RESONANCE ENERGY TRANSFER MEASUREMENTS

Understanding the photophysical properties of fluorescent proteins (FPs), such as emission and absorption spectra, molecular brightness, photostability, and photoswitching, is critical to the development of criteria for their selection as tags for fluorescence-based biological applications. My overall goal has been to study the photophysical properties of FPs under various excitation conditions, quantify the contributions that photophysical effects make to Förster resonance energy transfer (FRET) measurements, and provide appropriate experimental guidelines for FRET studies.Over the past two decades, we have witnessed a mounting interest in the study of protein localization and interactions using two-photon excitation (TPE) of fluorescently labeled proteins. While there is a plethora of information available regarding the photophysical and photochemical properties of commonly used fluorescent proteins when subjected to single-photon excitation, unfortunately, there is still very limited information regarding these properties under TPE. Therefore, I started my research by investigating the photophysical properties of several widely used fluorescent proteins using two-photon microscopy with spectral resolution in both excitation and emission. The results provided in the first part of this dissertation indicate that a number of properties, including the excitation and emission spectra, the relative brightness, and the extent of photobleaching and photoswitching, are markedly different under TPE when compared to single-photon excitation. The second part of this dissertation describes a detailed study of the nature and degree of the contributions to FRET of the photophysical effects exhibited by FPs used as fluorescent tags for the proteins of interest. FRET is a widely used technique to study the quaternary structure of protein complexes (i.e., intermolecular distances and binding interfaces) in living cells. Critical to the interpretation of the results of such studies is the theoretical treatment of oligomers comprised of more than one donor and one acceptor that may exchange electronic excitations via FRET. The question has been theoretically addressed by developing the kinetic theory of FRET. However, there is no detailed analysis how FRET and the kinetic theory of FRET respond to photophysical effects such as photobleaching of the donor and acceptor tags. Herein, we have presented a comparative analysis of different protocols for calculation of the FRET efficiency. We studied the effects of changing the laser excitation power on FRET measurements by quantifying the deviations from the kinetic theory of FRET, which does not include photobleaching currently. We also used a simple but effective numerical method to estimate the degree to which photobleaching of donors and acceptors was responsible for the observed discrepancies between the two sets of FRET efficiencies. We found that under low excitation power, and with carefully selected excitation wavelengths, the FRET efficiency of an obligate trimeric construct, made by fusing one FRET donor and two FRET acceptors to one another, is in agreement within less than 2% with the FRET efficiency predicted by the kinetic theory of FRET. However, at higher excitation powers, the FRET efficiencies changed significantly, due to the photobleaching of both the donor, through direct excitation, and the acceptor, mostly through FRET-induced excitation. If ignored, these effects could cause systematic and random errors as large as 15% or more in the FRET efficiency values obtained from experiments, which would cause significant uncertainties regarding the quaternary structure to be determined. This study therefore provides critical information for selecting appropriate fluorescent proteins and experimental conditions for reliable FRET measurements in oligomeric complexes of associating molecules in living cells.2024-11-2

Biofuel Production from Waste Cooking Oils and its Physicochemical Properties in Comparison to Petrodiesel

Haphazard mining and consumption of fossil fuels have reduced petroleum reserves causing fossil fuel depletion and environmental degradation; thus, reflecting the need of the cheaper, renewable and eco-friendly alternative source of petroleum to meet the fuel demand. Million liters of edible oil used for cooking foods and date expired oils from oil manufacturers are discarded into sewage. This study primarily intends to study the feasibility of biodiesel production using such waste oils. In this work, biodiesel was prepared from waste cooking oils by a process called transesterification with NaOH as a catalyst. Our results showed that methyl ester (biodiesel) (92.67±0.90%), soap materials (1.33±0.224%) and glycerol (6±0.68%) were obtained after the transesterification of waste cooking oil. The physicochemical properties of biodiesel such as density, viscosity, volatility, surface tension and flashpoint were analyzed, which were found to be 0.862±0.006 g/cm3, 2.23±0.021 cP, 0.327×10-3±4.5×10-6 g/s, 32.03±0.138 dyne/cm, 169.67±0.810°C, respectively. These properties were compared with that of commercial diesel as well as with the values specified by the American Society for Testing and Materials (ASTM) D6751. The density and the surface tension of the biodiesel were found similar to that of petrodiesel but its volatility was 3 times lower. Fourier-transform infrared spectroscopy (FTIR) spectra of the biodiesel showed methyl ester functional group at 1436 cm-1. Based on the cost of the materials used for production, the cost of biodiesel was estimated to be about 81 Nepalese rupees (0.67 USD) per liter. The properties of biodiesel also met the standard values of ASTM D6751. These findings indicate that waste oil is one of the feasible biodiesel sources and it can be used as a suitable alternative to petrodiesel.</jats:p

Status of Sickle Cell Disease Among Tharu Population In Banke District of Nepal.

Sickle cell disease (SCD) is prevalent in malaria-endemic areas because the gene for sickle cell provides its carrier with resistance against malaria. In Nepal, malaria is prevalent in Terai, hence the susceptibility of SCD is high in this region. Being indigenous to the Terai, thousands of people in the Tharu communities of the Banke districting Nepal are believed to have suffered from sickle cell disease. The objective of this study was to find out the status of sickle cell disease among the Tharu population  of  Banke  district,  Nepal.  A  cross-sectional,  experimental  study  was  performed  among  systematically  randomly selected 275 samples from 3 Village Development Committee (VDCs). All the samples were first screened for the presence of sickle hemoglobin using the sickle solubility test method in Bheri Zonal Hospital. Then all sickle solubility positive samples were further processed for alkaline hemoglobin electrophoresis by using Interlab GenioS electrophoresis instrument. Out of a total 275 samples, 33 (12.0%) samples were confirmed as sickle solubility test positive. Among which, sickle cell trait was the most common disorder found grossing to 81.8%, followed by homozygous sickle cell disease; (15.2 %). One case (3.0%) of compound heterozygous sickle beta-thalassemia was also found.The Males were found to be more affected than females with   ratio of 1.4:1.1. The highest frequency of SCD was found to be in 11-20 age groups comprising about 36.4%. Dangaura Tharu (51.5%) was the most common ethnic group with this disorder. The findings of this study indicate SCD is prevalent among the Tharu population in Banke district of Province-5, Nepal.</jats:p

Variation in Grain Zinc and Iron Concentrations, Grain Yield and Associated Traits of Biofortified Bread Wheat Genotypes in Nepal

Wheat (Triticum aestivum L.) is one of the major staples in Nepal providing the bulk of food calories and at least 30% of Fe and Zn intake and 20% of dietary energy and protein consumption; thus, it is essential to improve its nutritional quality. To select high-yielding genotypes with elevated grain zinc and iron concentration, the sixth, seventh, eighth, and ninth HarvestPlus Yield Trials (HPYTs) were conducted across diverse locations in Nepal for four consecutive years: 2015–16, 2016–17, 2017–18, and 2018–19, using 47 biofortified and 3 non-biofortified CIMMYT-bred, bread wheat genotypes: Baj#1, Kachu#1, and WK1204 (local check). Genotypic and spatial variations were found in agro-morphological traits; grain yield and its components; and the grain zinc and iron concentration of tested genotypes. Grain zinc concentration was highest in Khumaltar and lowest in Kabre. Likewise, grain iron concentration was highest in Doti and lowest in Surkhet. Most of the biofortified genotypes were superior for grain yield and for grain zinc and iron concentration to the non-biofortified checks. Combined analyses across environments showed moderate to high heritability for both Zn (0.48–0.81) and Fe (0.46–0.79) except a low heritability for Fe observed for 7th HPYT (0.15). Grain yield was positively correlated with the number of tillers per m2, while negatively correlated with days to heading and maturity, grain iron, grain weight per spike, and thousand grain weight. The grain zinc and iron concentration were positively correlated, suggesting that the simultaneous improvement of both micronutrients is possible through wheat breeding. Extensive testing of CIMMYT derived high Zn wheat lines in Nepal led to the release of five biofortified wheat varieties in 2020 with superior yield, better disease resistance, and 30–40% increased grain Zn and adaptable to a range of wheat growing regions in the country – from the hotter lowland, or Terai, regions to the dry mid- and high-elevation areas.</jats:p