Methyl Proton NMR Shifts of Coordinated Methanol in a Series of Co(CH,0H),X2+ Compounds

The isotropic contact NMR shifts of the coordinated cis and tram methanol methyl proton resonances of a series of Co(CH30H)5X2+ complexes were measured, where the ligand X was pyridine, /I- and a-picoline, DMF, DMSO, acetonitrile, and water. The question of how to separate the observed shifts into their respective Fermi contact and dipolar (pseudocontact) contributions was examined in detail with the result that a new procedure for carrying out the separation was proposed. The dipolar shifts for these complexes were found to vary widely, with the acetonitrile complex exhibiting the largest dipolar shift. For the DMSO and water complexes the sign of the dipolar shift was reversed relative to the others. Qualitatively this sign reversal may be related to the difference in ligand field strengths of methanol and X relative to the spin orbit soupling constant for cobalt (II). It was also concluded that the Fermi contact shift varied between complexes

THE RATE OF REDUCTION OF ACETATOPENTAMMINOCOBALT (III) PERFLUOROMETHANE SULFONATE BY CHROMOUS ION FROM 0 TO 120 DEGREES C

Abstract not availabl

Rapid Automatic Lighting Control of a Mixed Light Source for Image Acquisition using Derivative Optimum Search Methods

Automatic lighting (auto-lighting) is a function that maximizes the image quality of a vision inspection system by adjusting the light intensity and color.In most inspection systems, a single color light source is used, and an equal step search is employed to determine the maximum image quality. However, when a mixed light source is used, the number of iterations becomes large, and therefore, a rapid search method must be applied to reduce their number. Derivative optimum search methods follow the tangential direction of a function and are usually faster than other methods. In this study, multi-dimensional forms of derivative optimum search methods are applied to obtain the maximum image quality considering a mixed-light source. The auto-lighting algorithms were derived from the steepest descent and conjugate gradient methods, which have N-size inputs of driving voltage and one output of image quality. Experiments in which the proposed algorithm was applied to semiconductor patterns showed that a reduced number of iterations is required to determine the locally maximized image quality

Early childhood development when second-trimester ultrasound dating disagrees with last menstrual period: a prospective cohort study

<p>Abstract</p> <p>Background</p> <p>When an ultrasound-based estimate of gestational age (GA) is less (greater) than an estimate based on a definite last menstrual period, the fetus may grow slower (faster) than average. While the association between these discrepancies in GA estimates and adverse perinatal outcomes has been examined extensively, there is scant evidence about long-term effects, such as child neurodevelopment.</p> <p>Methods</p> <p>Using data from a prospective cohort study titled, NICHD Study of Successive Small-for-Gestational Age Births, we examined if GA discrepancies in early second trimester of pregnancy (17 weeks’ gestation) are associated with: (1) impaired motor and mental function at 13 months (measured using Bayley Scales of Infant Development (Bayley)), and (2) impaired cognitive development at five years (assessed by Wechsler Preschool and Primary Scale of Intelligence – Revised Intelligence Quotient (WPPSI-R)) in the infant. The study population consisted of 572 (30% of the overall sample of 1,945) women who presented for prenatal care in Norway and Sweden between 1986 and 1988.</p> <p>Results</p> <p>Our results showed that GA discrepancies in early second trimester are significantly associated with birthweight. We found no significant relationship, however, with the Bayley development scores at 13 months and with the WPPSI-R IQ measures at five years.</p> <p>Conclusions</p> <p>GA discrepancies at 17 weeks’ gestation are not associated child neurodevelopment. These discrepancies do, however, relate to birthweights, providing a basis for detecting fetal growth patterns early in the second trimester of pregnancy. Our study, however, was unable to evaluate the impact of first-trimester discrepancies on impaired neurodevelopment in the infant.</p