481 research outputs found
Wald Confidence Intervals for a Single Poisson Parameter and Binomial Misclassification Parameter When the Data is Subject to Misclassification
This thesis is based on a Poisson model that uses both error-free data and error-prone data subject to misclassification in the form of false-negative and false-positive counts. We present maximum likelihood estimators (MLEs), Fisher\u27s Information, and Wald statistics for Poisson rate parameter and the two misclassification parameters. Next, we invert the Wald statistics to get asymptotic confidence intervals for Poisson rate parameter and false-negative rate parameter. The coverage and width properties for various sample size and parameter configurations are studied via a simulation study. Finally, we apply the MLEs and confidence intervals to one real data set and another realistic data set
Chemoselective Formation of Unsymmetrically Substituted Ethers from Catalytic Reductive Coupling of Aldehydes and Ketones with Alcohols in Aqueous Solution
A well-defined cationic Ru–H complex catalyzes reductive etherification of aldehydes and ketones with alcohols. The catalytic method employs environmentally benign water as the solvent and cheaply available molecular hydrogen as the reducing agent to afford unsymmetrical ethers in a highly chemoselective manner
Scope and Mechanistic Analysis for Chemoselective Hydrogenolysis of Carbonyl Compounds Catalyzed by a Cationic Ruthenium Hydride Complex with a Tunable Phenol Ligand
A cationic ruthenium hydride complex, [(C6H6)(PCy3)(CO)RuH]+BF4– (1), with a phenol ligand was found to exhibit high catalytic activity for the hydrogenolysis of carbonyl compounds to yield the corresponding aliphatic products. The catalytic method showed exceptionally high chemoselectivity toward the carbonyl reduction over alkene hydrogenation. Kinetic and spectroscopic studies revealed a strong electronic influence of the phenol ligand on the catalyst activity. The Hammett plot of the hydrogenolysis of 4-methoxyacetophenone displayed two opposite linear slopes for the catalytic system 1/p-X-C6H4OH (ρ = −3.3 for X = OMe, t-Bu, Et, and Me; ρ = +1.5 for X = F, Cl, and CF3). A normal deuterium isotope effect was observed for the hydrogenolysis reaction catalyzed by 1/p-X-C6H4OH with an electron-releasing group (kH/kD = 1.7–2.5; X = OMe, Et), whereas an inverse isotope effect was measured for 1/p-X-C6H4OH with an electron-withdrawing group (kH/kD = 0.6–0.7; X = Cl, CF3). The empirical rate law was determined from the hydrogenolysis of 4-methoxyacetophenone: rate = kobsd[Ru][ketone][H2]−1 for the reaction catalyzed by 1/p-OMe-C6H4OH, and rate = kobsd[Ru][ketone][H2]0 for the reaction catalyzed by 1/p-CF3-C6H4OH. Catalytically relevant dinuclear ruthenium hydride and hydroxo complexes were synthesized, and their structures were established by X-ray crystallography. Two distinct mechanistic pathways are presented for the hydrogenolysis reaction on the basis of these kinetic and spectroscopic data
Convergence within a polyhedron: controller design for time-delay systems with bounded disturbances
Becoming an Entrepreneur after Retirement: Entrepreneurial Intention of Technically and Vocationally Trained Military Personnel in Sri Lanka
This study was conducted to study the entrepreneurial intention of military personnel who are getting ready for their retirement and identify the key determents of entrepreneurial intention. They were undergoing a Technical Vocational Education and Training (TVET) organized by the military authorities for supporting their second career. Data were collected from 70 solders via questionnaire and Step wise regression analysis was used to evaluate the effects of variables. Self-efficacy, perceived environmental support and vocational education and training are significant predictors of entrepreneurial intention. This study presents detailed and solid results on entrepreneurial intentions which are positioned in the career literature. Keywords: Entrepreneurial intention, Military personnel, Subjective Norm, Technical Vocational Education and Training (TVET
Antagonistic Effect of Eight Sri Lankan Isolates of Pseudomonas fluorescens on, Meloidogyne incognita in Tomato, Lycopersicon esculentum
The study was conducted to determine the efficacy of Pseudomonas fluorescens isolates collected from eight locations in the Central Province of Sri Lanka against Meloidogyne incognita in tomato. Isolates were tested under laboratory conditions to determine the efficacy on egg hatchability and mortality of second stage juveniles. A planthouse experiment was conducted using potted tomato plants to determine the potential of P. fluorescens isolates and effective application technique. All tested isolates have significantly inhibited egg hatchability and increased the juvenile mortality after 72 hours. P. fluorescens isolate from Kangkung field in Pallekelle (PK) and tomato field in Udispattuwa (UT I) recorded 95% and 95.5% inhibition of egg hatchability after 72 hours. P. fluorescens isolates collected from tomato fields in Bopane (BT II) and Udispattuwa (UT II) and from Kangkung field in Pallekelle recorded the higher mortality of second stage juveniles 93%, 87% and 83.3% respectively. The highest reduction in the root knots (96.8%, 96.3%), egg masses (98.5%, 98.2%) and lower root galling index (1 and 1) were recorded in tomato plants treated as soil drench with UT II and PK isolates respectively.The root dipping technique gave higher reduction in the number of root knots (47.4%), egg masses (44.9%) and lower root galling index (3.75) were recorded from BT II, UT II and tomato fields in Nugethenna (NT) isolates respectively. UT II and PK found to be the most effective isolates and most effective application technique determined as soil drenching ten days after transplanting under plant house conditions
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