Influence of CaCl2.2H2O Content on the Productive Process of Composites from Cotton Gin Waste

AbstractPrevious studies have shown the feasibility of production of masonry blocks and panels from agglomeration of cotton gin waste and calcium binders. Cotton gin waste is a serious problem for ginning plants, because in Argentina approximately 300,000 t of lignocellulosic wastes are produced annually without any final disposal destination. The accumulation of these residues is associated with pests and fire hazards. Since these composites are produced with simple equipment and a minimum energy requirement, their cost depends mainly on the binder (Portland cement) used and the process efficiency, since with a high productivity model, labor and equipment depreciation costs are significantly reduced. This paper analyzes the influence of CaCl2.2H2O (added as an accelerator for cement paste strength) on the minimum molding time required for composites manufacturing. A central composite experimental design was developed in order to study the interrelated variables. The influence of CaCl2.2H2O content on physical-mechanical cement paste properties and their relationship with composites stability are also evaluated. The results of this work show that CaCl2.2H2O content has significant influence on the efficiency of composites manufacturing as it reduces the molding time required

The effect of sintering temperature on the properties of the BiOCl films for potential application in DSSC

In this work, BiOCl films were obtained by tape casting using BiOCl powders synthesized by the co-precipitation method. The effect of the film's sintering temperature (300 °C–600 °C) on the morphology, chemical composition, crystalline phases and optical characteristics was studied. The obtained BiOCl powders showed a flake-like morphology, a tetragonal crystalline structure without secondary phases and a wide band gap of 3.53 eV. For BiOCl films, results indicated that as the sintering temperature increased the flake-like shaped particles changed to rectangular ones while the amount of chlorine in the films decreased. A phase transition from tetragonal BiOCl to monoclinic Bi24O31Cl10 was also observed as the sintering temperature increased. Consequently, optical studies revealed that the band gap of BiOCl films decreased from 3.03 eV to 2.82 eV. FTIR analysis demonstrated that the organic groups were removed from the films only for sintering temperatures above 400 °C. The Rhodamine B dye adsorption capacity of BiOCl films decreased with increasing sintering temperature. The results obtained allow us to conclude that BiOCl films are suitable for use in DSSC when the sintering temperature is in the range of 400–500 °C

Potencial Analítico de los Polímeros de Impronta Molecular (MIPs) como Elementos de Reconocimiento Biomimético

Los polímeros de impronta molecular (MIPs) son materiales sintéticos que presentan propiedades de reconocimiento molecular específico hacia determinados compuestos. Estos materiales con “memoria selectiva” presentan un elevado potencial analítico como sustitutos de elementos de reconocimiento de origen biológico para el desarrollo de sensores, como sorbentes en procesos de extracción en fase sólida (SPE) y como fases estacionarias para HPLC y CE. La síntesis de estos materiales se basa en la formación de una estructura polimérica, altamente entrecruzada, alrededor de una molécula que actúa como plantilla que se extrae después de la polimerización. De esta forma, el MIP contendrá sitios de unión que son complementarios a la molécula plantilla en forma, tamaño y distribución de grupos funcionales que permiten su reconocimiento posterior, de forma selectiva Los MIPs suelen presentar ventajas interesantes en comparación con los receptore

Effective Lagrangian Approach to the Theory of Eta Photoproduction in the N∗(1535)N^{*}(1535) Region

We investigate eta photoproduction in the $N^{*}(1535)$ resonance region within the effective Lagrangian approach (ELA), wherein leading contributions to the amplitude at the tree level are taken into account. These include the nucleon Born terms and the leading $t$-channel vector meson exchanges as the non-resonant pieces. In addition, we consider five resonance contributions in the $s$- and $u$- channel; besides the dominant $N^{*}(1535)$, these are: $N^{*}(1440),N^{*}(1520),N^{*}(1650)$ and $N^{*}(1710)$. The amplitudes for the $\pi^\circ$ and the $\eta$ photoproduction near threshold have significant differences, even as they share common contributions, such as those of the nucleon Born terms. Among these differences, the contribution to the $\eta$ photoproduction of the $s$-channel excitation of the $N^{*}(1535)$ is the most significant. We find the off-shell properties of the spin-3/2 resonances to be important in determining the background contributions. Fitting our effective amplitude to the available data base allows us to extract the quantity $\sqrt{\chi \Gamma_\eta} A_{1/2}/\Gamma_T$, characteristic of the photoexcitation of the $N^{*}(1535)$ resonance and its decay into the $\eta$-nucleon channel, of interest to precise tests of hadron models. At the photon point, we determine it to be $(2.2\pm 0.2)\times 10^{-1} GeV^{-1}$ from the old data base, and $(2.2\pm 0.1) \times 10^{-1} GeV^{-1}$ from a combination of old data base and new Bates data. We obtain the helicity amplitude for $N^{*}(1535)\rightarrow \gamma p$ to be $A_{1/2}=(97\pm 7)\times 10^{-3} GeV^{-1/2}$ from the old data base, and $A_{1/2}=(97\pm 6)\times 10^{-3} GeV^{-1/2}$ from the combination of the old data base and new Bates data, compared with the results of the analysis of pion photoproduction yielding $74\pm 11$, in the same units.Comment: 43 pages, RevTeX, 9 figures available upon request, to appear in Phys. Rev.

Single-cultivar extra virgin olive oil classification using a potentiometric electronic tongue

Label authentication of monovarietal extra virgin olive oils is of great importance. A novel approach based on a potentiometric electronic tongue is proposed to classify oils obtained from single olive cultivars (Portuguese cvs. Cobrançosa, Madural, Verdeal Transmontana; Spanish cvs. Arbequina, Hojiblanca, Picual). A meta-heuristic simulated annealing algorithm was applied to select the most informative sets of sensors to establish predictive linear discriminant models. Olive oils were correctly classified according to olive cultivar (sensitivities greater than 97%) and each Spanish olive oil was satisfactorily discriminated from the Portuguese ones with the exception of cv. Arbequina (sensitivities from 61% to 98%). Also, the discriminant ability was related to the polar compounds contents of olive oils and so, indirectly, with organoleptic properties like bitterness, astringency or pungency. Therefore the proposed E-tongue can be foreseen as a useful auxiliary tool for trained sensory panels for the classification of monovarietal extra virgin olive oils.This work was co-financed by FCT and FEDER under Program COMPETE (Project PEst-C/EQB/LA0020/2013)

Cognitive disorders in patients with chronic kidney disease: Approaches to prevention and treatment

Background: Cognitive impairment is common in patients with chronic kidney disease (CKD), and early intervention may prevent the progression of this condition. Methods: Here, we review interventions for the complications of CKD (anemia, secondary hyperparathyroidism, metabolic acidosis, harmful effects of dialysis, the accumulation of uremic toxins) and for prevention of vascular events, interventions that may potentially be protective against cognitive impairment. Furthermore, we discuss nonpharmacological and pharmacological methods to prevent cognitive impairment and/or minimize the latter's impact on CKD patients' daily lives. Results: A particular attention on kidney function assessment is suggested during work-up for cognitive impairment. Different approaches are promising to reduce cognitive burden in patients with CKD but the availabe dedicated data are scarce. Conclusions: There is a need for studies assessing the effect of interventions on the cognitive function of patients with CKD

The XMM Cluster Survey: Exploring scaling relations and completeness of the Dark Energy Survey Year 3 redMaPPer cluster catalogue

We cross-match and compare characteristics of galaxy clusters identified in observations from two sky surveys using two completely different techniques. One sample is optically selected from the analysis of three years of Dark Energy Survey observations using the redMaPPer cluster detection algorithm. The second is X-ray selected from XMM observations analysed by the XMM Cluster Survey. The samples comprise a total area of 57.4 deg$^2$, bounded by the area of 4 contiguous XMM survey regions that overlap the DES footprint. We find that the X-ray selected sample is fully matched with entries in the redMaPPer catalogue, above $\lambda>$20 and within 0.1$< z <$0.9. Conversely, only 38\% of the redMaPPer catalogue is matched to an X-ray extended source. Next, using 120 optically clusters and 184 X-ray selected clusters, we investigate the form of the X-ray luminosity-temperature ($L_{X}-T_{X}$), luminosity-richness ($L_{X}-\lambda$) and temperature-richness ($T_{X}-\lambda$) scaling relations. We find that the fitted forms of the $L_{X}-T_{X}$ relations are consistent between the two selection methods and also with other studies in the literature. However, we find tentative evidence for a steepening of the slope of the relation for low richness systems in the X-ray selected sample. When considering the scaling of richness with X-ray properties, we again find consistency in the relations (i.e., $L_{X}-\lambda$ and $T_{X}-\lambda$) between the optical and X-ray selected samples. This is contrary to previous similar works that find a significant increase in the scatter of the luminosity scaling relation for X-ray selected samples compared to optically selected samples.Comment: Accepted for publication to MNRA

Investigating the role of customers’ perceptions of employee effort and justice in service recovery

Purpose: The purpose of this paper is, first, to identify the relationship, if any, between customers’ perceptions of justice (functional element) and employee effort (symbolic element) and their effects on satisfaction and loyalty in the context of service recovery and, second, to determine the impact of cross-cultural differences on these relationships. Design/methodology/approach: Survey data from actual customers were gathered in three countries (n = 414) and analyzed using structural equation modeling to test the proposed hypotheses. Findings: The results demonstrate the role of the constructs of perceived employee effort and perceived justice in influencing post-recovery satisfaction and loyalty across cultures. While perceived justice is valued across cultures, customers from feminine (masculine) cultures require more (less) employee effort to influence post-recovery satisfaction positively. Customers from low (high) uncertainty cultures are more (less) willing to give the provider another chance after a service recovery. Research limitations/implications: The study shows that both functional and symbolic elements of service recovery are important determinants of customer satisfaction and loyalty and that their influence can be significant in a cross-cultural context. Practical implications: International service managers must consider the nature of cultural differences in their markets to develop and implement tailored recovery strategies that can result in satisfied customers. Originality/value: This study is the first to integrate the functional and symbolic elements of service recovery, their impact on customers’ behavioral responses and the influence of cultural variations

Evolution of the use of corticosteroids for the treatment of hospitalised COVID-19 patients in Spain between March and November 2020: SEMI-COVID national registry

Objectives: Since the results of the RECOVERY trial, WHO recommendations about the use of corticosteroids (CTs) in COVID-19 have changed. The aim of the study is to analyse the evolutive use of CTs in Spain during the pandemic to assess the potential influence of new recommendations. Material and methods: A retrospective, descriptive, and observational study was conducted on adults hospitalised due to COVID-19 in Spain who were included in the SEMI-COVID- 19 Registry from March to November 2020. Results: CTs were used in 6053 (36.21%) of the included patients. The patients were older (mean (SD)) (69.6 (14.6) vs. 66.0 (16.8) years; p < 0.001), with hypertension (57.0% vs. 47.7%; p < 0.001), obesity (26.4% vs. 19.3%; p < 0.0001), and multimorbidity prevalence (20.6% vs. 16.1%; p < 0.001). These patients had higher values (mean (95% CI)) of C-reactive protein (CRP) (86 (32.7-160) vs. 49.3 (16-109) mg/dL; p < 0.001), ferritin (791 (393-1534) vs. 470 (236- 996) µg/dL; p < 0.001), D dimer (750 (430-1400) vs. 617 (345-1180) µg/dL; p < 0.001), and lower Sp02/Fi02 (266 (91.1) vs. 301 (101); p < 0.001). Since June 2020, there was an increment in the use of CTs (March vs. September; p < 0.001). Overall, 20% did not receive steroids, and 40% received less than 200 mg accumulated prednisone equivalent dose (APED). Severe patients are treated with higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%. Conclusions: Patients with greater comorbidity, severity, and inflammatory markers were those treated with CTs. In severe patients, there is a trend towards the use of higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%