Comparación de las dos metodologías de análisis y diseño más recientes de ASCE 7, para el análisis de su posible empleo en edificaciones con aislamiento sísmico de base en Colombia

Base seismic isolation is a seismic protection technique for buildings, successful and with great use worldwide. In Colombia there are currently some buildings that incorporate this technique, which have been designed under the requirements of American regulations in force at the time, such is the case of ASCE 7-10. Aforementioned regulation has been recently updated to its 2016 version, with important technical changes with respect to its predecessor. ASCE 7-16 incorporates the results of the most recent research in terms of seismic isolation, future buildings that use this technique and that are designed and built in the country should follow this document. For all the aforementioned, it is evident the necessity of make an analysis of the new design philosophy for buildings with base isolation and discus its applicability to the country.El aislamiento de base es una técnica de protección sismorresistente para edificaciones, con un uso exitoso y amplio a nivel mundial. En Colombia actualmente existen algunos edificios que incorporan esta técnica, los cuales fueron diseñados bajo los requisitos de normativas americanas vigentes en la época, como ASCE 7-10. Dicha normativa ha sido recientemente actualizada a su versión 2016, con importantes cambios técnicos respecto a su predecesora.ASCE 7-16 incorpora resultados de las investigaciones más recientes en cuanto a aislamiento sísmico se refiere, por ende las futuras edificaciones que emplean esta técnica y que sean diseñadas y construidas en el país deberían seguir dicho documento. Es por todo lo anterior que en el presente trabajo se evidencia la necesidad de hacer un análisis de la nueva filosofía de diseño para edificaciones con aislamiento de base y discutir su aplicabilidad en el país

Cardiovascular, respiratory, gastrointestinal and behavioral effects of intravenous lidocaine in healthy, conscious horses and evaluation of the relationship with lidocaine and monoethylglycinexylidide serum concentrations

This study aimed to evaluate the relationship between the serum concentrations of lidocaine/ monoethylglycinexylidide (MEGX) and their effects on several systems in horses. Five healthy, conscious horses received a two-hour placebo intravenous infusion followed by a two-hour lidocaine infusion (bolus of 1.3 mg/kg over ten minutes followed by a continuous rate infusion of 0.05 mg/kg/min). Lidocaine and MEGX serum concentrations were sampled every ten to fifteen minutes during the experiment, and the presence of muscle fasciculations and loss of balance as well as the respiratory, digestive and cardiovascular systems of the five horses were evaluated by means of different non-invasive methods. During the lidocaine infusion, the mean (f SD) lidocaine and MEGX concentrations were respectively 768.88 +/- 93.32ng/ml and 163.08 +/- 108.98 ng/ml. The infusion of lidocaine significantly influenced the presence of fasciculations, caused a statistically but non-clinically significant decrease of systolic and diastolic blood pressures, which were both correlated with lidocaine and MEGX serum concentrations, and it increased the duodenal contractions frequency, which was correlated with the serum lidocaine concentration. In this study, mild hypotensive and prokinetic effects of short-term lidocaine infusion were observed

Ferri- and ferro-magnetism in CaMnMReO6 double double perovskites of late transition metals M = Co and Ni

International audienceTwo new double double perovskites of ideal compositions CaMnMReO6 (M = Co, Ni) are reported. The M = Co material has refined composition CaMn0.7Co1.3ReO6 and orders ferrimagnetically below TC = 188 K with a relatively large saturated magnetisation of 4.5 μB. The M = Ni product, CaMn1.2Ni0.8ReO6, is a remarkable example of a ferromagnetic oxide with four distinct spin sublattices all collinearly ordered below TC = 152 K

Matrix converter for frequency changing power supply applications

The purpose of this work is to investigate the design and implementation of a 7.5kVA Matrix Converter-based power supply for aircraft applications (GPU Ground Power Unit). A Matlab/Simulink as well as SABER simulation analysis of the candidate Matrix Converter system is provided. The design and implementation of the Matrix Converter is described, with particular attention to the strict requirements of the given power supply application. This AC-AC system is proposed as an effective replacement for the conventional AC-DC-AC system which employs a two-step power conversion. The Matrix Converter is an attractive topology of power converter for power supply applications where factors such as the absence of electrolytic capacitors, the potentiality of increasing power density, reducing size and weight and good input power quality are fundamental. An improved control structure is proposed. This structure employs an ABC reference frame implementation comprising at the Repetitive Control strategy combined with a traditional tracking controller in order to attenuate or eliminate the unwanted harmonic distortion in the output voltage waveform of the Matrix Converter and to compensate for the steady-state error. The system with the proposed control was initially fully analyzed and verified by simulation. The analysis of the input and output waveforms identified the constraints that need to be satisfied to ensure successful operation of the converter. Finally, to demonstrate both the Matrix Converter concept and the control strategy proposed, a 7.5kVA prototype of the proposed system was constructed and tested in Nottingham PEMC laboratory. The experimental results obtained confirmed the expectations from the simulation study and the validity of the power converter and control design

Case Based Reasoning for Chemical Engineering Design

With current industrial environment (competition, lower profit margin, reduced time to market, decreased product life cycle, environmental constraints, sustainable development, reactivity, innovation…), we must decrease the time for design of new products or processes. While the design activity is marked out by several steps, this article proposed a decision support tool for the preliminary design step. This tool is based on the Case Based Reasoning (CBR) method. This method has demonstrated its effectiveness in other domains (medical, architecture…) and more recently in chemical engineering. This method, coming from Artificial Intelligence, is based on the reusing of earlier experiences to solve new problems. The goal of this article is to show the utility of such method for unit operation (for example) pre-design but also to propose several evolutions for CBR through a domain as complex as the chemical engineering is (because of its interactions, non linearity, intensification problems…). During the pre-design step, some parameters like operating conditions are not precisely known but we have an interval of possible values, worse we only have a partial description of the problem.. To take into account this imprecision in the problem description, the CBR method is coupled with the fuzzy sets theory. After a mere presentation of the CBR method, a practical implementation is described with the choice and the pre-design of packing for separation columns

Building C(sp(3)) Molecular Complexity on 2,2 '-Bipyridine and 1,10-Phenanthroline in Rhenium Tricarbonyl Complexes

The reactions of [Re(N-N)(CO)(3)(PMe3)]OTf (N-N=2,2 '-bipyridine, bipy; 1,10-phenanthroline, phen) compounds with tBuLi and with LiHBEt3 have been explored. Addition to the N-N chelate took place with different site-selectivity depending on both chelate and nucleophile. Thus, with tBuLi, an unprecedented addition to C5 of bipy, a regiochemistry not accessible for free bipy, was obtained, whereas coordinated phen underwent tBuLi addition to C2 and C4. Remarkably, when LiHBEt3 reacted with [Re(bipy)(CO)(3)(PMe3)]OTf, hydride addition to the 4 and 6 positions of bipy triggered an intermolecular cyclodimerization of two dearomatized pyridyl rings. In contrast, hydride addition to the phen analog resulted in partial reduction of one pyridine ring. The resulting neutral Re-I products showed a varied reactivity with HOTf and with MeOTf to yield cationic complexes. These strategies rendered access to Re-I complexes containing bipy- and phen-derived chelates with several C(sp(3)) centers