Density Functional Calculations On First-Row Transition Metals

The excitation energies and ionization potentials of the atoms in the first transition series are notoriously difficult to compute accurately. Errors in calculated excitation energies can range from 1--4 eV at the Hartree-Fock level, and errors as high as 1.5eV are encountered for ionization energies. In the current work we present and discuss the results of a systematic study of the first transition series using a spin-restricted Kohn-Sham density-functional method with the gradient-corrected functionals of Becke and Lee, Yang and Parr. Ionization energies are observed to be in good agreement with experiment, with a mean absolute error of approximately 0.15eV; these results are comparable to the most accurate calculations to date, the Quadratic Configuration Interaction (QCISD(T)) calculations of Raghavachari and Trucks. Excitation energies are calculated with a mean error of approximately 0.5eV, compared with \sim 1\mbox{eV} for the local density approximation and 0.1eV for QCISD(T). These gradient-corrected functionals appear to offer an attractive compromise between accuracy and computational effort.Comment: Journal of Chemical Physics, 29, LA-UR-93-425

SISTEM INFORMASI EKSEKUTIF BIDANG PRODUKSI PADA CV. MITRA PALEMBANG

This thesis basically discusses the executive information system sector production at CV. Mitra Palembang. The purpose to be achieved from this thesis is help leaders in determining long-term strategic planning for producing furniture according to the availability of raw materials and the public interest. New design system that will help to accelerate and facilitate the activities of the company for now and the future. This thesis use FAST method (Framework for The Application of System Thinking). This method is a combination of best practices that find in many references methodology and commercial. In other word FAST method is intelligent framework that is flexible enough to provide various types of projects and strategies. This writing is done by comparing the execution of the old system with a theory book that the author learned in writing thesis. There are steps being taken by the author, include : analyze the problem, make feasibility study, implementation and maintenance and evaluation. With this expected to help companies streamline and minimize labo

Expanding field education: Hope Trust Community Garden

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Efeito da irrigação no estabelecimento de plântulas de Manduvi transplantadas Em pastagens cultivadas.

O esforço para a conservação da arara-azul no Pantanal deve enfocar a manutenção de populações viáveis de Manduvi. Caso seja diagnosticado que o recrutamento populacional de Manduvi desta árvore no Pantanal é insatisfatório para a reposição de adultos, torna-se urgente o desenvolvimento de um programa de manejo e conservação de populações de Manduvi. Neste sentido, este trabalho investigou o estabelecimento de plântulas de Manduvi, com 60 dias de semeadura, transplantadas em pastagens cultivadas, que substituíram a vegetação original na área da fazenda Nhumirim. The effort to conserve hyacinth macaws in the Pantanal should focus on the maintenance of viable populations of Manduvi. If it is diagnosed that the recruitment of this tree population in the Pantanal is unsatisfactory for the replacement of adults, it becomes urgent to develop a program management and conservation of populations of Manduvi. Thus, this study investigated the establishment of seedlings of Manduvi, with 60 days of sowing, transplanting in cultivated pastures, which replaced the original vegetation in the area of the Nhumirim Farm

Cholinergic modulation of Up–Down states in the mouse medial entorhinal cortex in vitro

Cholinergic tone is high during wake and rapid eye movement sleep and lower during slow wave sleep (SWS). Nevertheless, the low tone of acetylcholine during SWS modulates sharp wave ripple incidence in the hippocampus and slow wave activity in the neocortex. Linking the hippocampus and neocortex, the medial entorhinal cortex (mEC) regulates the coupling between these structures during SWS, alternating between silent Down states and active Up states, which outlast neocortical ones. Here, we investigated how low physiological concentrations of acetylcholine (ACh; 100‐500 nM) modulate Up and Down states in a mEC slice preparation. We find that ACh has a dual effect on mEC activity: it prolongs apparent Up state duration as recorded in individual cells and decreases the total synaptic charge transfer, without affecting the duration of detectable synaptic activity. The overall outcome of ACh application is excitatory and we show that ACh increases Up state incidence via muscarinic receptor activation. The mean firing rate of principal neurons increased in around half of the cells while the other half showed a decrease in firing rate. Using two‐photon calcium imaging of population activity, we found that population‐wide network events are more frequent and rhythmic during ACh and confirmed that ACh modulates cell participation in these network events, consistent with a role for cholinergic modulation in regulating information flow between the hippocampus and neocortex during SWS

Application of Gradient-Corrected Density Functional Theory to the Structures and Thermochemistries of \mbox{ScF}_3, \mbox{TiF}_4, \mbox{VF}_5, and \mbox{CrF}_6

Density functional theory(DFT) and Hartree-Fock(HF) calculations are reported for the family of transition metal fluorides \mbox{ScF}_3, \mbox{TiF}_4, \mbox{VF}_5, and \mbox{CrF}_6. Both HF and the local-density-aproximation (LDA) yield excellent agreement with experimental bond lengths, while the B-LYP gradient-corrected density functional gives bond lengths $0.04-0.05$ \AA\ too long. An investigation of various combinations of exchange and correlation functionals shows that, for this series, the origin of this behavior lies in the Becke exchange functional. Much improved bond distances are found using the hybrid HF/DFT functional advocated by Becke. This approximation also leads to much improved thermochemistries. The LDA overestimates average bond energies in this series by $30-40$ kcal/mol, whereas the B-LYP functional overbinds by only $\sim8-12$ kcal/mol, and the hybrid HF/DFT method overbinds by only $\sim 2$ kcal/mol. The hybrid method predicts the octahedral isomer of \mbox{CrF}_6 to be more stable than the trigonal prismatic form by $14$ kcal/mol. Comparison of theoretical vibrational frequencies with experiment supports the assignment of an octahedral geometry.Comment: 18 pages, latex, 1 figure, Submitted to Journal of Chemical Physic