Real-time monitoring of the transesterification reaction in biodiesel production

Studio del cambiamento della viscosità, on-line, durante una reazione di trans-esterificazione per la produzione di biodiesel. Conseguente analisi di campioni prelevati durante la reazione attraverso HPLC con lo scopo di confermare il collegamento tra viscosità ed effettiva produzione di biodiesel (Esteri metilici di acidi grassi).ope

Anharmonic Assignment of the Water Octamer Spectrum in the OH Stretch Region

We interface thequasi-classical trajectory approachwith an ab initio potential energy surface for waterto assign thevibrational spectroscopical features of the OH stretch region of thewater octamer cluster, which is considered to be a precursor of ice.An attempt by Li et al. to assign their recent reference experimentinvolved lower-level calculations based on an ad hoc scaled harmonic approach. Differently from the conclusions of thisprevious assignment, which invoked the contribution of 5 conformersand a solvated form of the water heptamer in the spectrum, we findout that the spectroscopic features can be related to the 4 conformersof the octamer lying lower in energy

Dynamics and interaction of vortex lines in an elongated Bose-Einstein condensate

We study the real-time dynamics of vortex lines in a large elongated Bose-Einstein condensate (BEC) of sodium atoms using a stroboscopic technique. Vortices are spontaneously produced via the Kibble-Zurek mechanism in a quench across the BEC transition and then they slowly precess keeping their orientation perpendicular to the long axis of the trap as expected for solitonic vortices in a highly anisotropic condensate. Good agreement with theoretical predictions is found for the precession period as a function of the orbit amplitude and the number of condensed atoms. In configurations with two or more vortex lines, we see signatures of vortex-vortex interaction in the shape and visibility of the orbits. In addition, when more than two vortices are present, their decay is faster than the thermal decay observed for one or two vortices. The possible role of vortex reconnection processes is discussed.Comment: 4 pages, 4 figure

MODELAGEM UTILIZANDO DINÂMICA DE SISTEMAS: o caso de uma suinocultura no município de Sapezal-MT

A cadeia de suprimento consiste em um conjunto de empresas que, de forma sistêmica, transforma matérias-primas em produtos acabados. Neste artigo, foi feito um estudo de caso sobre uma suinocultura no estado de Mato Grosso. Baseado nos conceitos de estrutura de governança, estratégias empresariais, práticas sustentáveis e através de uma entrevista com o administrador, foi possível mapear o planejamento adotado pela empresa, evidenciando-se as inter-relações entre os agentes da cadeia de suprimento, a forma de comercialização entre eles e o fluxo de materiais e informações pela cadeia. Tais observações resultaram em uma descrição do sistema sob o enfoque da engenharia de produção. Além disso, com o suporte do software stella, foi apresentado o diagrama de estoque e fluxo do sistema, constituindo-se em uma forma visual para analisar o problema

Enteral versus intravenous approach for the sedation of critically ill patients: a randomized and controlled trial

Background. ICU patients must be kept conscious, calm, and cooperative even during the critical phases of illness. Enteral administration of sedative drugs might avoid oversedation, and would be as adequate as intravenous for awake patients, with fewer side effects and lower costs. This study compares two sedation strategies, in order to early reach and maintain the light sedation target. Methods. Multicenter, single-blind randomized and controlled trial carried out in 12 Italian ICUs, involving patients with expected mechanical ventilation duration >72 hours at ICU admission and predicted mortality >12% (Simplified Acute Physiology Score II >32 points) during the first 24 ICU hours. Patients were randomly assigned to receive intravenous (midazolam, propofol) or enteral (hydroxyzine, lorazepam, and melatonin) sedation. Primary outcome: percentage of work shifts with an observed Richmond Agitation-Sedation Scale (RASS) = target RASS \ub1 1. Secondary outcomes: protocol feasibility, delirium- and coma-free days, costs of drugs, length of ICU and hospital stay, ICU, hospital, and one-year mortality. Results. 348 patients were enrolled. There were no differences in the primary outcome: enteral 89.8 [74.1-100], intravenous 94.4 [78-100]%, p=0.20. Enteral-treated patients had more protocol violations: 81 (46.6%) vs 7 (4.2%), p<0.01, more self-extubations: 4 (2.4%) vs 14 (8.1%), p=0.03, a lighter sedative target (RASS = 0): 93 [71-100] vs 83 [61-100]%, p<0.01, and lower total costs for drugs: 2.39 [0.75- 9.78] vs 4.15 [1.20 -20.19] \u20ac/day with mechanical ventilation (p=0.01). Conclusions. Although enteral sedation of critically ill patients is cheaper and permits a lighter sedation target, it is not superior to intravenous sedation for reaching the RASS target. Trial registration. ClinicalTrials.gov, Clinical Trial #NCT01360346, registered 25 March 2011, https://clinicaltrials.gov/ct2/show/NCT01360346. Registered on 25 March 2011

Real-time monitoring of the transesterification reaction in biodiesel production

Studio del cambiamento della viscosità, on-line, durante una reazione di trans-esterificazione per la produzione di biodiesel. Conseguente analisi di campioni prelevati durante la reazione attraverso HPLC con lo scopo di confermare il collegamento tra viscosità ed effettiva produzione di biodiesel (Esteri metilici di acidi grassi)

Comparison of Cortisol, Androstenedione and Metanephrines to Assess Selectivity and Lateralization of Adrenal Vein Sampling in Primary Aldosteronism

Success of adrenal vein sampling (AVS) is verified by the selectivity index (SI), i.e., by a step-up of cortisol levels between the adrenal vein and the infrarenal inferior vena cava samples, beyond a given cut-off. We tested the hypothesis that androstenedione, metanephrine, and normetanephrine, which have higher gradients than cortisol, could increase the rate of AVS studies judged to be bilaterally successful and usable for the clinical decision making. We prospectively compared within-patient, head-to-head, the selectivity index of androstenedione (SIA), metanephrine (SIM), and normetanephrine (SINM), and cortisol (SIC) in consecutive hypertensive patients with primary aldosteronism submitted to AVS. Main outcome measures were rate of bilateral success, SI values, and identification of unilateral PA. We recruited 136 patients (55 + 10 years, 35% women). Compared to the SIC, the SIA values were 3.5-fold higher bilaterally, and the SIM values were 7-fold and 4.4-fold higher on the right and the left side, respectively. With the SIA and the SIM the rate of bilaterally successful AVS increased by 14% and 15%, respectively without impairing the identification of unilateral PA. We concluded that androstenedione and metanephrine outperformed cortisol for ascertaining AVS success, thus increasing the AVS studies useable for the clinical decision making