Convección natural asociada a pozas de enfriamiento por aspersión

Las pozas de enfriamiento por aspersión son intercambiadores de calor de tipo evaporativo de contacto directo agua-aire. Así, agua de proceso a alta temperatura se enfrla mediante la aspersión en pequeñas gotas, consiguiendo un aumento considerable del área de transferencia de calor y masa, resultando en una mayor cantidad de energía que las gotas entregan al aire debido al efecto convectivo y al calor latente de vaporización de la masa de agua que se evapora. Las transferencias que se producen alteran la temperatura y humedad del aire circundante, dando origen a fuerzas de empuje que inducen a una convección natural de aire en la poza de aspersión. En otro trabajo de los autores (10) se estudia este efecto, considerando que la convección natural inducida es conocida, con ello se consigue una considerable simplificación del problema planteado. En el presente trabajo no se considera esta simplificación, y el estudio se realiza acoplando numéricamente las ecuaciones de continuidad, transporte de momemtum y la ecuación de Poisson, para el campo dinámico y las ecuaciones de transporte de energfa y transporte de masa para los campos térmico y másico. Ambos campos están ligados principalmente a través de la fuerza de empuje del aire caliente y hlímedo que atraviesa la zona de aspersión, como también de las propiedades del aire. Se presenta el estudio, modelación y resolución numérica de tipo discreta de una poza cilíndrica, atendiendo las ventajas que este tipo de coordenadas presenta para el modelo. El sistema de ecuaciones álgebra diferencia/no lineal resultante, se resuelve por el método numérico de diferencias finitas

Compassion-based meditation quality practice and its impact on the positive attitudes toward others

Objectives: The authors report on the initial development and validation of the Compassion Practice Quality Scale (CPQS), a measure to assess the quality of compassion-based meditation (CBM). It is conceptualized and operationalized via two factors measuring mental imagery and somatic perception/response. Methods: The total sample was composed of 205 university students who underwent a CBM and completed pre-test/post-test assessment of compassion and related constructs. Results from a series of preliminary psychometric analyses of the CPQS were examined, including factor analysis, internal consistency, and convergent/discriminant validity. Results: The data supported a 12-item and 10-item (without reference to gestures and self-instructions) CPQS of which imagery and somatic perception emerged as two significant reliable subscales, with Cronbach’s alpha values of.90 and.88 respectively. Practice quality factors assessed by the CPQS correlated in expected ways with fear of compassion, imagery variables, and self-criticism, as well as predicted compassion outcome (i.e., feeling positive attitudes toward others). Conclusions: Our findings contribute to identifying two key components of high-quality meditation in CBM (i.e., mental imagery and somatic perception/response) for use in pedagogical development and further research and to offer a reliable self-report measure to assess them for the first time. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature

New Evidence on Regucalcin, Body Composition, and Walking Ability Adaptations to Multicomponent Exercise Training in Functionally Limited and Frail Older Adults

Background: Regucalcin, or senescence marker protein-30 (SMP30), is a Ca2+-binding protein with multiple functions reported in the literature. Physical exercise has been shown to improve aging markers; nevertheless, SMP30 in humans has not been extensively researched. Older adults experience a decline in functional capacity and body composition. The purpose of this study was to examine the effects of a multicomponent training (MCT) program on SMP30 and its regulation of walking ability and body composition in functionally limited, frail, and pre-frail older adults. Methods: A total of 34 older adults (aged 80.3 +/- 6.1 years) were divided into an intervention group (IG = 20) and control group (CG = 14). The IG performed a supervised MCT (strength, endurance, balance, coordination, and flexibility) program for 6 months, 3 days per week, whereas the CG continued their normal lives without any specific physical training. SMP30 was analyzed in plasma after 3 and 6 months of MCT, while some physical fitness variables (Timed Up and Go (TUG) and 6-min walk test (6MWT)) and body composition (fat mass and lean mass) were measured at baseline, as well as after 3 months and 6 months of MCT. Results: No significant changes were observed in SPM30 between the IG (877.5 a.u. to 940.5 a.u., respectively) and CG (790.4 a.u. to 763.8 a.u., respectively). Moreover, no SMP30 differences were found between groups after 3 and 6 months of MCT. The IG improved significantly in the 6MWT after 3 months (472.2 +/- 84.2 m) compared to baseline (411.2 +/- 75.2 m). The IG also significantly enhanced their TUG performance after 3 months (7.6 +/- 1.6 s) and 6 months (7.3 +/- 1.8 s) of training compared to baseline (9.3 +/- 3.2 s) (all, p < 0.001). There were no significant differences in body composition between the IG and CG through the 6 months of MCT. Conclusions: The present study suggests that MCT did not change SMP30 levels from 3 to 6 months, where there were changes in neither walking ability nor body composition; however, MCT was effective in improving 6MWT and TUG performance from baseline to 3 months

Amplified Spontaneous Emission in Pentathienoacene Dioxides by Direct Optical Pump and by Energy Transfer: Correlation with Photophysical Parameters

Amplified spontaneous emission (ASE) is observed, under optical pump, in polystyrene films doped with two pentathienoacene derivatives functionalised with thienyl-S,S-dioxide groups (compounds 2 and 3). The effect of the dioxide groups on the ASE properties is analysed by comparing the performance with that of its corresponding non-oxidized analogue (1). Films containing either 2 or 3 show ASE at 511 and 574 nm, respectively, when excited directly (at 435 nm) on their absorption bands, showing thresholds and linewidths larger than those obtained from films doped with 1, pumped at 355 nm. ASE is also observed under excitation at 355 nm, in samples containing 1 (host) and either 2 or 3 (guests), due to energy transfer from host to guest. For the blends with 3, the ASE threshold is lower than that obtained when the films are excited directly. Results are interpreted in terms of the photophysical parameters such as absorption capacity, fluorescence efficiency, singlet-to-triplet intersystem crossing leading to triplet-triplet re-absorptions, bimolecular energy-transfer efficiency, efficiency of internal conversion process, etc. State-of-the-art quantum chemical calculations are used in the interpretation of the experimental results.Authors from the University of Alicante acknowledge support from the Spanish Government (MINECO) and the European Community (FEDER) through grants MAT2008–06648-C02–01 and MAT2011–28167-C02–01. The work at the University of Málaga is supported by the MEC projects CTQ2012–33733 and by the PO9–4708 project by the Junta de Andalucía. Raquel Rondão acknowledges FCT for a PhD grant (SFRH/BD/38882/2007). D.A.S.F. gratefully acknowledges the financial support from the Brazilian Research Councils: CAPES, CNPq (grant 303084/2010–3) and FAP-DF (Fundação de Apoio à Pesquisa do Distrito Federal)

Improvements in Chilean patients with obesity following a 5-month multidisciplinary exercise program: A feasibility study

Background: The aim of this study was to determine the effects of a multidisciplinary exercise program on physical fitness, metabolic profile and nutritional status of obese patients. Methods: Seventeen women and four men (N.=21, age 18 to 60 years), with severe obesity (BMI=35-40 kg/m2, N.=7), morbid obesity (BMI=40-50 kg/m2, N.=9), and super obesity (BMI>50 kg/m2, N.=5), took part in a physical exercise program with nutritional and psychological support. The intermittent physical exercise program was applied three times per week (1 hour/session), with 4-8 exercises with weights. Three series were carried out for 60 s each, with increasing intensity leading to exhaustion at the end of the period and with 1-2 min recovery between series. Outcomes include the BMI, waist contour, blood pressure, cardiorespiratory fitness, exercise capacity, maximum dynamic strength, hand grip strength, basal glucose and lipid profiles. Results: The patients decreased in weight and BMI (P<0.05). Morbid (N.=9) and super obese (N.=5) improved their cardiorespiratory fitness (P=0.005 and 0.040) and lowered their triglycerides (-25.70% and -15.38%; P=0.008). Hand grip strength improved in the super obese (P<0.001). Descriptively, patients with super obesity had the largest improvements. Conclusions: Multi-modal lifestyle and exercise interventions improve the condition especially in super obese patients. The improved health status may improve the outcome of secondary steps in weight loss, such as bariatric surgery. The program was feasible to be executed and patients compliant to the intervention

Combined Raman spectroscopic and Rietveld analyses as a useful and nondestructive approach to studying flint raw materials at prehistoric archaeological sites

Artículo sobre análisis de espectroscopía

Fibre-optic SPR sensor with a FBG interrogation scheme for readout enhancement

In this work a new configuration of a refractometric sensor for aqueous solutions based on the combination of surface plasmon resonance (SPR) with fibre Bragg gratings (FBG) is presented. Two FBGs are selected having reflection maxima in each side of the plasmon resonance peak. These FBGs enable a different processing scheme for the information provided by the SPR transducer. This improved interrogation method increases the sensitivity and resolution of the sensor compared with those obtained with the usual method of tracking the spectral transmittance minimum and makes the system performance independent of optical source power fluctuations. The experimental results obtained with a double-layer uniform-waist tapered fibre show the feasibility of this approach and its applicability in SPR-based biosensors that must face very exigent measuring conditions

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Performance and Operation of the CMS Electromagnetic Calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

Structural Conformers of (1,3-Dithiol-2-ylidene)ethanethioamides: The Balance Between Thioamide Rotation and Preservation of Classical Sulfur-Sulfur Hypervalent Bonds

The reaction of N-(2-phthalimidoethyl)-N-alkylisopropylamines and S2Cl2 gave 4-N-(2-phthalimidoethyl)-N-alkylamino-5-chloro-1,2-dithiol-3-thiones that quantitatively cycloadded to dimethyl or diethyl acetylenedicarboxylate to give stable thioacid chlorides, which in turn reacted with one equivalent of aniline or a thiole to give thioanilides or a dithioester. Several compounds of this series showed atropisomers that were studied by a combination of dynamic NMR, simulation of the signals, conformational analysis by DFT methods, and single crystal X-ray diffraction, showing a good correlation between the theoretical calculations, the experimental values of energies, and the preferred conformations in the solid state. The steric hindering of the crowded substitution at the central amine group was found to be the reason for the presence of permanent atropisomers in this series of compounds and the cause of a unique disposition of the thioxo group at close-to-right angles with respect to the plane defined by the 1,3-dithiole ring in the dithiafulvene derivatives, thus breaking the sulfur–sulfur hypervalent bond that is always found in this kind of compounds.Ministerio de Economıá y Competitividad, Spain (Project CTQ2012- 31611), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Project BU246A12-1), and the European Commission, Seventh Framework Programme (Project SNIFFER FP7-SEC-2012-312411