21 research outputs found
Formation of triphenylmethyl cation during the photolysis of phenylazotriphenyl methane a laser flash photolysis study
A kinetic study of atom transfer radical polymerization of styrene with bis(2-pyridyl)ethylenedimethanimine derivative ligands
Atom transfer radical polymerization (ATRP) of styrene was carried out with multidentate nitrogenbased ligands, namely N,N'-bis[phenyl(pyrid-2-yl) methylene] ethane-1,2-diamine (BPDA) and N,N'-bis[methyl(pyrid- 2-yl)methylene] ethane-1,2-diamine (BMDA), and catalyst systems at catalyst/ligand molar ratios of 1/0.33, 1/0.5, 1/1, and 1/1.5 by using 2 different initiators, (1-bromoethyl)benzene (BEB) and ethyl-2-bromopropionate (EBP). Linear first-order kinetic plots were observed for ATRP of styrene upon using BPDA as a ligand with both initiators. Even though the linear slopes indicate that radical concentration remains constant during reactions, high molecular weights were obtained at low conversion and showed a linear relation thereafter. To investigate the molecular weight effect, reactions were also performed in the presence of (1-bromoethyl)benzene initiator in dimethylformamide (DMF) for BPDA and in toluene for BMDA using a catalyst/ligand ratio of 1/1.© TÜBITAK
Studies on the copolymerization of cyclic disulfide lipoamide with styrene. II. Laser flash photolysis investigation
Accuracy of two different voxel sizes for presurgical evaluation of mandibular osteotomy
The aim of this study was to compare the accuracy of two different voxel resolutions for the preoperative assessment of mandibular osteotomies. The study was conducted on 37 dry adult human mandibles. To obtain measurement standardization, heated gutta-percha cones were placed on the dry mandibles to mark 20 anatomical points. These cones were used for all measurement groups. Cone beam computerized tomography (CBCT) scans of the mandibles were made using 0.200 mm(3) and 0.400 mm(3) voxel sizes (Planmeca Promex-3D Helsinki, Finland). The results obtained from these two groups were compared with physical measurements obtained using a digital calliper, in order to analyze their predictive value. In the study, one voxel size did not have supremacy over the other in terms of accuracy. For mandibular osteotomies, 0.400 mm(3) voxel size can be preferred because of lower radiation dose. (C) 2019 Published by Elsevier Masson SAS
Improvement of Peat Using Portland Cement and Electrokinetic Injection Technique
Peat is often referred as problematic soil due to its high compressibility, low shear strength, and high water content. However, high surface electrical charge and high cationic exchange capacity of peat makes it a good source for transporting and/or exchange with cations. In this study, a series of batch test is performed to find out the effect of strength improvement of portland cement mixed with the peat. Then, the feasibility of injecting cement electrokinetically into peaty soil environment has been assessed. The microstructure of the treated peat was also investigated by scanning electron microscopy and energy-dispersive X-ray spectrometer analysis. The results showed that the undrained shear strength, pH, and water content of treated peat are affected after electrokinetic treatment. Because of the electrokinetic process, the undrained shear strength was improved to maximum of 308 % and minimum of 30 % in the normalized distance of 0.1 and 0.9 from anode, respectively. The pH was also increased to the maximum of 8 in the normalized distance of 0.1 and 0.9 from the anode. However, the water content was reduced after 7 days of electrokinetic processing
In vitro comparative activity of meropenem with 15 other antimicrobial agents against 1798 Pseudomonas aeruginosa isolates in a French multicenter study
Síndrome ascítica em frangos de corte: uma revisão sobre a fisiologia, avaliação e perspectivas Ascitic syndrome in broiler chickens: a review about physiology, evaluation and perspectives
Os programas de melhoramento genético de frangos de corte que buscam máxima velocidade de ganho de peso, alta eficiência alimentar, alta viabilidade, maior rendimento de carcaça e menor deposição de gordura podem desencadear algumas síndromes fisiológicas, dentre as quais destacam-se o estresse calórico, a morte súbita e a ascite. A ascite se enquadra no conceito das síndromes multifatoriais, uma vez que sua manifestação ocorre quando certos fatores genéticos e ambientais atuam em conjunto determinando o processo. As limitações anatômica e fisiológica da circulação sanguínea nos pulmões provocam a síndrome de hipertensão pulmonar (PHS); esta pode provocar grande acúmulo de fluido na cavidade abdominal, quadro este denominado de ascite. Ocorre redução da eficiência da circulação sangüínea, levando as aves à morte por hipóxia, predominantemente no período entre 30 e 40 dias de idade. Uma vez desencadeado o processo ascítico, a ave dificilmente é aproveitada no abate já que a mesma restringe o consumo de alimento, ganhando menos peso. Adicionalmente, a carcaça apresenta aumento do volume da cavidade abdominal e conseqüente congestão dos órgãos internos. A descrição da fisiologia, medidas de avaliação e perspectivas são apresentadas neste trabalho.<br>Poultry genetic breeding programs which look for maximum weight gain, improved feed conversion, high viability, high carcass yield and low fat deposition may cause some physiologic syndromes, for example caloric stress, sudden death and ascites. Ascites is framed in concept of the multifactorial syndromes, once its manifestation happens when certain genetic and environment factors act together, determining the process. Anatomical and physiological limitations in blood circulation in the lungs give rise to pulmonary hypertension syndrome (PHS), producing great fluid accumulation in abdominal cavity, which is denominated ascites. Ascites causes reduction of blood circulation efficiency, leading broilers to death due to hypoxia, mainly between 30 and 40 days of age. Ascitic broilers have reduced body weight gain as a consequence of feed restriction. Additionally, there is increased abdominal cavity volume and internal organ congestion. Ascites is discussed through this manuscript based on physiological description, evaluation measures and perspectives
Dyna: Extending Datalog For Modern AI ⋆
Abstract. Modern statistical AI systems are quite large and complex; this interferes with research, development, and education. We point out that most of the computation involves database-like queries and updates on complex views of the data. Specifically, recursive queries look up and aggregate relevant or potentially relevant values. If the results of these queries are memoized for reuse, the memos may need to be updated through change propagation. We propose a declarative language, which generalizes Datalog, to support this work in a generic way. Through examples, we show that a broad spectrum of AIalgorithms can be concisely captured by writing down systems of equations in our notation. Many strategies could be used to actually solve those systems. Our examples motivatecertainextensionstoDatalog, whichareconnectedtofunctional and object-oriented programming paradigms. 1 Why a New Data-Oriented Language for AI? Modern AI systems are frustratingly big, making them time-consuming to enginee