Fuels are inevitable for industrial development and growth of any country. The life span of fossil fuel resources has always been terrifying. Biodiesel, a renewable source of energy seems to be an ...ideal solution for global energy demands including India as well. The current review is addressed to various aspects of biodiesel production. Latest literature has been critically reviewed and consulted.
Equilibrium and thermodynamic studies of the removal of cadmium by adsorption on an indigenous adsorbent, china clay, have been investigated. The results of effect of temperature and thermodynamic ...parameters confirm the process of removal to be exothermic in nature. The removal decreased from 80.3% to 51.3% by increasing the temperature from 30 to 50
°C at 5.10
×
10
−5
M initial concentration of cadmium, 1.0
×
10
−2
M NaClO
4 ionic strength, 6.5 pH, 100
μm particle size and 100
rpm. Rate was found in decreasing pattern with increasing temperature and value of rate constant of the reaction,
k
ad, was found to be 5.10
×
10
−2
min
−1 at 30
°C. Values of Langmuir's constants, ‘
Q
o’ and ‘
b’ were also determined. Thermodynamic parameters namely enthalpy of adsorption, isosteric heat of adsorption, change in standard free energy, Δ
G°, standard enthalpy, Δ
H°, and standard entropy, Δ
S° were determined.
An ever increasing demand of fuels has been a challenge for today’s scientific workers. The fossil fuel resources are dwindling day by day. Biodiesel seems to be a solution for future. Biodiesel is ...an environmentally viable fuel. Out of the four ways viz. direct use and blending, micro-emulsions, thermal cracking and transesterification, most commonly used method is transesterification of vegetable oils, fats, waste oils, etc. Latest aspects of development of biodiesel have been discussed in this work. Yield of biodiesel is affected by molar ratio, moisture and water content, reaction temperature, stirring, specific gravity, etc. Biodegradability, kinetics involved in the process of biodiesel production, and its stability have been critically reviewed. Emissions and performance of biodiesel has also been reported.
This paper reviews the effects of corrosion on the engine parts that come in contact with a newly developed biodiesel fuel and its petrodiesel blend. Copper, aluminum, copper alloys (bronze), and ...elastomers caused significant levels of corrosiveness in biodiesel and biodiesel blend as opposed to low corrosion with petrodiesel. Specimens of stainless steel showed significant resistance to corrosion in biodiesel samples as compared to copper, aluminum, and copper alloys, but the level of corrosion was still higher than that in petrodiesel. Common methods adopted for measurement of corrosion include weight loss through static emersion tests, and electrochemical techniques by electrochemical impedance spectroscopy or on Potentiostat/Galvanostat. The surfaces of the specific metal strips were analyzed by optical, scanning electron, and atomic force microscopy, revealing the nature and extent of corrosion. Fourier Transform Infrared Spectroscopy revealed formation of secondary product due to degradation, and X-ray diffractometer revealed formation of a new phase in the metal strips exposed to biodiesel and its blend with mineral diesel. Biodiesel seemed to degrade due to auto-oxidation and presence of moisture to secondary products that enhanced the corrosion rate. The problem related to the use of non-compatible materials as engine parts for biodiesel-run vehicles is dual in nature. The engine part in contact with the fuel is corroded as a result of fuel degradation, causing the fuel to go further off-specification.
ZnCo2O4 has been synthesized by the low‐temperature and cost‐effective urea combustion method. X‐ray diffraction (XRD), HR‐TEM and selected area electron diffraction (SAED) studies confirmed its ...formation in pure and nano‐phase form with particle size ∼ 15–20 nm. Galvanostatic cycling of nano‐ZnCo2O4 in the voltage range 0.005–3.0 V versus Li at 60 mA g–1 gave reversible capacities of 900 and 960 mA h g–1, when cycled at 25 °C and 55 °C, respectively. These values correspond to ∼ 8.3 and ∼ 8.8 mol of recyclable Li per mole of ZnCo2O4. Almost stable cycling performance was exhibited in the range 5–60 cycles at 60 mA g–1 and at 25 °C with ∼ 98 % coulombic efficiency. A similar cycling stability at 55 °C, and good rate‐capability both at 25 and 55 °C were found. The average discharge‐ and charge‐potentials were ∼ 1.2 V and ∼ 1.9 V, respectively. The ex‐situ‐XRD, ‐HRTEM, ‐SAED and galvanostatic cycling data are consistent with a reaction mechanism for Li‐recyclability involving both de‐alloying‐alloying of Zn and displacement reactions, viz., LiZn ↔ Zn ↔ ZnO and Co ↔ CoO ↔ Co3O4. For the first time we have shown that both Zn‐ and Co‐ions act as mutual beneficial matrices and reversible capacity contribution of Zn through both alloy formation and displacement reaction takes place to yield stable and high capacities. Thus, nano‐ZnCo2O4 ranks among the best oxide materials with regard to Li‐recyclability.
Nanophase ZnCo2O4 has been synthesized, characterized and tested for Li‐recyclability. It exhibited reversible capacities of 900 mAh/g (8.3 moles of Li) in the voltage range 0.005–3.0V vs Li at 60 mA/g up to 60 cycles with excellent rate capability.
The Zwicky Transient Facility (ZTF) is performing a three-day cadence survey of the visible northern sky (∼3π) with newly found transient candidates announced via public alerts. The ZTF Bright ...Transient Survey (BTS) is a large spectroscopic campaign to complement the photometric survey. BTS endeavors to spectroscopically classify all extragalactic transients with mpeak ≤ 18.5 mag in either the gZTF or rZTF filters, and publicly announce said classifications. BTS discoveries are predominantly supernovae (SNe), making this the largest flux-limited SN survey to date. Here we present a catalog of 761 SNe, classified during the first nine months of ZTF (2018 April 1-2018 December 31). We report BTS SN redshifts from SN template matching and spectroscopic host-galaxy redshifts when available. We analyze the redshift completeness of local galaxy catalogs, the redshift completeness fraction (RCF; the ratio of SN host galaxies with known spectroscopic redshift prior to SN discovery to the total number of SN hosts). Of the 512 host galaxies with SNe Ia, 227 had previously known spectroscopic redshifts, yielding an RCF estimate of 44% 4%. The RCF decreases with increasing distance and decreasing galaxy luminosity (for z < 0.05, or ∼200 Mpc, RCF 0.6). Prospects for dramatically increasing the RCF are limited to new multifiber spectroscopic instruments or wide-field narrowband surveys. Existing galaxy redshift catalogs are only ∼50% complete at r 16.9 mag. Pushing this limit several magnitudes deeper will pay huge dividends when searching for electromagnetic counterparts to gravitational wave events or sources of ultra-high-energy cosmic rays or neutrinos.
► Extensive kinetic studies of synthesis of biodiesel. ► Synthesis of catalyst from a waste bioresource. ► Application of a waste-feedstock: waste frying oil. ► Optimization of important reaction ...parameters. ► A high yield and conversion of the feedstock to biodiesel.
Waste frying oil was used to produce biodiesel using calcined snail shell as a heterogeneous base catalyst. Trans esterification reactions were carried out and the yield and conversion of the product were optimized by varying the methanol to oil molar ratio, catalyst amount, reaction temperature, and time. A biodiesel conversion of 99.58% was obtained with a yield of 87.28%. The reaction followed first order kinetics. The activation energy (
E
A) was 79
kJ/mol and the frequency factor (
A) was 2.98
×
10
10
min
−1. The fuel properties of the biodiesel were measured according to ASTM D 6751 and found to be within the specifications. Snail shell is a novel source for the production of heterogeneous base catalyst that can be successfully utilized for synthesis of biodiesel of high purity.
Development of biodiesel from karanja tree, mainly found in rural India has been investigated. The biodiesel was developed from oil expelled from the seeds of the tree. Molecular weight of the oil ...was determined and found to be 892.7. Both the acid as well as alkaline esterification were subsequently performed to get the final product. NaOH was found to be a better catalyst than KOH in terms of yield. Maximum yield of 89.5% was achieved at 8:1 molar ratio for acid esterification and 9:1 molar ratio for alkaline esterification, 0.5
wt.% catalyst (NaOH/KOH) using mechanical stirrer.
Abstract The use of novel active ingredients for the functional modification of chitosan nanoformulations has attracted global attention. In this study, chitosan has been functionalized via histidine ...to craft novel chitosan–histidine nanoformulation (C–H NF) using ionic gelation method. C–H NF exhibited elite physico-biochemical properties, influencing physiological and biochemical dynamics in Tomato. These elite properties include homogenous-sized nanoparticles (314.4 nm), lower PDI (0.218), viscosity (1.43 Cps), higher zeta potential (11.2 mV), nanoparticle concentration/ml (3.53 × 10 8 ), conductivity (0.046 mS/cm), encapsulation efficiency (53%), loading capacity (24%) and yield (32.17%). FTIR spectroscopy revealed histidine interaction with C–H NF, while SEM and TEM exposed its porous structure. Application of C–H NF to Tomato seedling and potted plants through seed treatment and foliar spray positively impacts growth parameters, antioxidant-defense enzyme activities, reactive oxygen species (ROS) content, and chlorophyll and nitrogen content. We claim that the histidine-functionalized chitosan nanoformulation enhances physico-biochemical properties, highlighting its potential to elevate biochemical and physiological processes of Tomato plant.
Spectroscopic detection of narrow emission lines traces the presence of circumstellar mass distributions around massive stars exploding as core-collapse supernovae. Transient emission lines ...disappearing shortly after the supernova explosion suggest that the material spatial extent is compact and implies an increased mass loss shortly prior to explosion. Here, we present a systematic survey for such transient emission lines (Flash Spectroscopy) among Type II supernovae detected in the first year of the Zwicky Transient Facility survey. We find that at least six out of ten events for which a spectrum was obtained within two days of the estimated explosion time show evidence for such transient flash lines. Our measured flash event fraction (>30% at 95% confidence level) indicates that elevated mass loss is a common process occurring in massive stars that are about to explode as supernovae.
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