Synthesis and Characterisation of Addition Compounds of Pyridine Carboxylic Acid Hydrazides with Tin (IV) Halides, Organotin (IV) Halides and Thicyanates*

Addition compounds of the compositions SnX/sub 4/.xL and R/sub n/SnX/sub 4-n/.xL where X=Cl/sup -/, Br/sup -/, I/sup -/, or (NCS)/sup -/, R=phenyl or n-butyl, L = picolinic acid hydrazide (PH), nicotinic acid hydrazide (NH) or isonicotinic acide hydrazide (INH), x=1 or 2 and n= 1,2 or 3 have been prepared and characterised with the help of elemental analysis, molar conductance, UV and IR spectral studies. All the adducts are nonionic as evidenced from their low molar conductances in DMF. UV and IR spectral studies show that NH and INH coordiante through carbonyl oxygen and terminal nitrogen; and (PH) through carbonyl oxygen and ring nitrogen in monoadducts. All the three isometric pyridine carboxylic acid hydrazides are coordinated through pyridine nitrogen alone in the di-adducts. Octahedral geometry has been proposed for mono-as well as di-adducts

Modelo de negocio y estrategia editorial: el caso del wsj.com

La investigación sobre modelos de negocios en la industria de la comunicación se ha caracterizado por un elevado grado de experimentación y la ausencia de respuestas unívocas al problema de la rentabilidad de los contenidos digitales. En este escenario, The Wall Street Journal suele ser mencionado como un referente del modelo de suscripción. Este artículo demuestra empíricamente que el modelo del diario económico más prestigioso del mundo ofrece un modelo híbrido en el que los contenidos gratuitos representan el 73% del total publicado en la portada del wsj.com y analiza cuáles son las características comunes que suelen compartir aquellos contenidos de pago frente a las compartidas por los contenidos gratuitos

An experimental evaluation of the understanding of safety compliance needs with models

Proceedings of: 36th International Conference on Conceptual Modeling, ER 2017, Valencia, Spain, November 6–9, 2017Context: Most safety-critical systems have to fulfil compliance needs specified in safety standards. These needs can be difficult to understand from the text of the standards, and the use of conceptual models has been proposed as a solution. Goal: We aim to evaluate the understanding of safety compliance needs with models. Method: We have conducted an experiment to study the effectiveness, efficiency, and perceived benefits in understanding these needs, with text of safety standards and with UML object diagrams. Results: Sixteen Bachelor students participated in the experiment. Their average effectiveness in understanding compliance needs and their average efficiency were higher with models (17% and 15%, respectively). However, the difference is not statistically significant. The students found benefits in using models, but on average they are undecided about their ease of understanding. Conclusions: Although the results are not conclusive enough, they suggest that the use of models could improve the understanding of safety compliance needs.The research leading to this paper has received funding from the AMASS project (H2020-ECSEL grant agreement no 692474; Spain’s MINECO ref. PCIN-2015-262) and the AMoDDI project (Ref. 11130583). We also thank the subjects that participated in the experiment

Traumatic Clivus Epidural Hematoma: Case Report and Review of the Literature

BACKGROUND: Traumatic clival epidural hematoma is an extremely rare reported entity. CASE DESCRIPTION: We describe the case of a 26-year-old woman involved in a car accident who presented with a Glasgow Coma Scale score of 13, bilateral abducens palsy, bilateral numbness on the mandibular territory of the trigeminal nerve, and left hypoglossal palsy. Radiological examinations revealed a clival epidural hematoma. The patient was managed conservatively, with clinical improvement of her neurological condition. This is the first traumatic clival epidural hematoma reported in an adult. From a review of the literature, we found only 8 cases. CONCLUSION: The pathophysiology of these hematomas is still a subject of debate; occipitoatlantoaxial ligamentous instability may play a role in it. In one third of the cases, bilateral cranial nerve palsies were associated. Apparently, they have a benign outcome

The surface diffusion of gold atoms on gold electrodes in acid solution and its dependence on the presence of foreign adsorbates

The surface diffusion coefficient (Ds) of Au atoms in 0.5 M H2SO4 at 298 K has been determined from the time dependence of the surface roughness factor of electrodispersed Au electrodes in 0.5 M H2SO4. The value of Ds for 0.5 M H2SO4 is 5 × 10−14 cm2 s−1, a figure which depends considerably on the presence of adsorbable species in solution. Thus, the adsorption of pyridine produces a remarkable decrease of Ds, whereas the adsorption of Cl− ion results in the opposite effect. The corresponding values of Ds are 1.2 × 10−14 cm2 s−1 for 0.5 M H2SO4 + 0.1 M pyridine, and 2.5 × 10−13 cm2 s−1 for 0.5 M H2SO4 + 5 × 10−4 M KCl. These results are interpreted through the influence of the adsorbate on the Au surface atom diffusion mechanism.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)Facultad de Ciencias Exacta

The surface diffusion of gold atoms on gold electrodes in acid solution and its dependence on the presence of foreign adsorbates

The surface diffusion coefficient (Ds) of Au atoms in 0.5 M H2SO4 at 298 K has been determined from the time dependence of the surface roughness factor of electrodispersed Au electrodes in 0.5 M H2SO4. The value of Ds for 0.5 M H2SO4 is 5 × 10−14 cm2 s−1, a figure which depends considerably on the presence of adsorbable species in solution. Thus, the adsorption of pyridine produces a remarkable decrease of Ds, whereas the adsorption of Cl− ion results in the opposite effect. The corresponding values of Ds are 1.2 × 10−14 cm2 s−1 for 0.5 M H2SO4 + 0.1 M pyridine, and 2.5 × 10−13 cm2 s−1 for 0.5 M H2SO4 + 5 × 10−4 M KCl. These results are interpreted through the influence of the adsorbate on the Au surface atom diffusion mechanism.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)Facultad de Ciencias Exacta

Moving Bullet Syndrome

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