Performance, emission and combustion characteristics of a semi-adiabatic diesel engine using cotton seed and neem kernel oil methyl esters

AbstractThe performance, emission and combustion characteristics of a diesel engine are investigated using two methyl esters: One obtained from cotton seed oil and other from neem kernel oil. These two oils are transesterified using methanol and alkaline catalyst to produce the cotton seed oil methyl ester (CSOME) and neem kernel oil methyl ester (NKOME) respectively. These biodiesels are used as alternative fuels in low heat rejection engine (LHR), in which the combustion chamber temperature is increased by thermal barrier coating on piston face. Experimental investigations are conducted with CSOME and NKOME in a single cylinder, four stroke, direct injection LHR engine. It is found that, at peak load the brake thermal efficiency is lower by 5.91% and 7.07% and BSFC is higher by 28.57% and 10.71% for CSOME and NKOME in LHR engine, respectively when compared with conventional diesel fuel used in normal engine. It is also seen that there is an increase in NOx emission in LHR engine along with slight increase in CO, smoke and HC emissions. From the combustion characteristics, it is found that the values of cylinder pressure for CSOME and NKOME in LHR engine are near to the diesel fuel in normal engine

Formation constants of binary & ternary chelates of Ln(III) with maltol & kojic acid in presence of amino carboxylic acids

174-175The formation constants of binary and ternary systems involving 3-hydroxy-2-methyl-4-pyrone (HMP) (maltol) and 5-hydroxy-2-hydroxymethyl-4-pyrone (HOMP) (kojic acid), with lanthanide metal ions [La(III), Pr(II), Nd(III), Gd(III), Dy(III) and Y(III)] in the presence of iminodiacetic acid (IMDA), hydroxyethyliminodiacetic acid (HIMDA) and nitrilotriacetic acid (NTA) have been determined in aqueous medium at 30°C and μ = 0.1 M (NaClO4). The order of stabilities of ternary systems is: HMP > HOMP and IMDA > HIMDA > NTA. These are explained in the light of the basi-cities of the Iigands and charge neutralisation

Physical Layer Security in Vehicular Communication Networks in the Presence of Interference

This paper studies the physical layer security of a vehicular communication network in the presence of interference constraints by analysing its secrecy capacity. The system considers a legitimate receiver node and an eavesdropper node, within a shared network, both under the effect of interference from other users. The double-Rayleigh fading channel is used to capture the effects of the wireless communication channel for the vehicular network. We present the standard logarithmic expression for the system capacity in an alternate form, to facilitate analysis in terms of the joint moment generating functions (MGF) of the random variables representing the channel fading and interference. Closed-form expressions for the MGFs are obtained and Monte-Carlo simulations are provided throughout to validate the results. The results show that performance of the system in terms of the secrecy capacity is affected by the number of interferers and their distances. The results further demonstrate the effect of the uncertainty in eavesdropper location on the analysis

Formation Constants of Binary Complexes of Lanthanides with 2-Hydroxymethylbenzimidazole

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Formation of Binary & Ternary Chelates of Calmagite with Lanthanides in Presence of Some Amino Polycarboxylic Acids

172-173The formation constants of 1:1 and 1:2 binary Ln(III)-calmagite (CLM) and 1:1:1 ternary [Ln(III)-CLM-A] chelates [where Ln(III)=La, Pr, Nd, Gd, Dy and Y; A= iminodiacetic acid (IMDA), hydroxyethyliminodiacetic acid (HIMDA) and nitrilotriacetic acid (NTA)] have been determined pH-metrically in 50% (v/v) aq. methanol medium at 30°C and I= 0.1 M (NaClO4). The ligand calmagite coordinates as a secondary ligand in presence of IMDA, HIMDA and NTA with all the metal ions. The order of formation constants of binary as well as ternary chelates is found to be: La Y

Evolution of orbital phases with particle size in nanoscale stoichiometric LaMnO3

The thermodynamically stable long-range orbital order in bulk LaMnO3 becomes metastable at nanoscale around a critical particle size d_C~20 nm. The orbital order-disorder transition switches from reversible to irreversible at d_C while the resistance in the orbital ordered state decays by 2-4% over a time scale of ~3000s. At well below d_C, of course, a stable orbital disordered phase emerges. The orthorhombic distortion of the underlying crystallographic structure (space group Pbnm) decreases systematically with the decrease in particle size and at far below d_C (e.g., at ~10 nm), the structure becomes cubic (space group Pm-3m). Using the crystallographic and electrical resistance data, a phase diagram has been constructed showing the evolution of different orbital phases as a function of particle size across ~10 nm to bulk for stoichiometric LaMnO3.Comment: revised following referees' comments, accepted for publicaton in J. Appl. Phy