CCD Photometry of the Globular Cluster NGC 5897

We report CCD photometric observations of the globular cluster NGC 5897, in the Johnson system filters B, V , R, and I. With the values for these magnitudes we obtain various colour indices and produce several colour-magnitude diagrams. We present eight colour-magnitude diagrams: V vs B-V , B vs B-V , V vs V-I, I vs V-I, R vs R-I, I vs R-I, V vs V-R, and R vs V-R. In all of these diagrams we can clearly see the Giant Branch, the Horizontal Branch and the beginning of the Main Sequence. To the left of the Main Sequence turn-off point we detect a somewhat large number of Blue Straggler stars. We determine the mean value of the visual magnitude of the HB as $16.60 \pm 0.46$. This value is fainter than the value found by other authors.Comment: 28 pages, 7 figures, accepted for publication RevMexAA, vol. 60-1, April 2024. arXiv admin note: text overlap with arXiv:1606.0452

Production of Antioxidant Additives and High-quality Activated Biochar from Pyrolysis of Argan Shells

An integral valorization route based on a pyrolysis process has been proposed to find sustainable applications for argan shells focused on the simultaneous production of activated biochar and antioxidant additives from bio-oil. The bio-oil obtained in the pyrolysis process was furtherly upgraded (hydrothermal treatment and extraction process) to obtain antioxidant additives. On the other hand, the biochar obtained in the pyrolysis was used as a feedstock to produce high-quality activated biochar (by physical activation with CO2). The increase in the pyrolysis temperature (350–550 °C) hardly affected the pyrolysis products distribution (biochar yields of 28–34 wt.% and bio-oil yields between 51 and 55 wt.%), but it led to a slight decrease in the content of phenolic monomers extracted from bio-oil (from 63 wt.% at 350 °C to 53 wt.% at 550 °C). When these extracted fractions were blended with biodiesel (<1 wt.%), improvements of up to 300% in biodiesel oxidation stability were attained. The hydrothermal treatment of the bio-oil did not show noteworthy effects either on the production or antioxidant performance of the extracted fractions if compared with the fractions extracted from the raw bio-oil. Regarding the valorization of argan shells biochar, the activated biochar prepared from it showed considerable potential as an adsorbent material for CO2 (125 mg of CO2 per g of the activated biochar) or phenols (complete removal of 99.6% in 4 h of contact time). It was characterized by a high BET surface area (up to 1500 m2/g), a high carbon content (up to 95 wt.%), low ash content (around 2 wt.%), and a pH of around 8

Ideas alternativas sobre cambio climático, adelgazamiento de la capa de ozono y lluvia ácida de un grupo de alumnos de centros de enseñanza permanente de adultos

Es mucha la información que recibimos en torno al cambio climático, el adelgazamiento de la capa de ozono y la lluvia ácida, y en relación a ello se generan muchas opiniones e ideas no exentas de polémica y de falta de rigor científico que hacen confundir causas y consecuencias de unos y otros. Se plantea la necesidad de posicionarnos como ciudadanos responsables ante las consecuencias de tan graves problemas, por lo que consideramos clave conocer más sobre las ideas del alumnado y su posible origen. Se ha elaborado y analizado un cuestionario para detectar posibles ideas alternativas relacionadas con los principales problemas de contaminación atmosférica. La muestra está formada por un grupo de alumnos de Educación Permanente de Adultos (EPA)

Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide Versus Dolutegravir/Abacavir/Lamivudine in Antiretroviral-Naive Adults (SYMTRI): A Multicenter Randomized Open-Label Study (PReEC/RIS-57)

Background. Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) is the reference for combination therapy based on protease inhibitors due to its efficacy, tolerability, and convenience. Head-to-head randomized comparisons between D/C/F/TAF and combination therapy based on integrase inhibitors in antiretroviral-naive patients are lacking. Methods. Adult (>18 years old) human immunodeficiency virus-infected antiretroviral-naive patients (HLA-B∗5701 negative and hepatitis B virus negative), with viral load (VL) ≥500 c/mL, were centrally randomized to initiate D/C/F/TAF or dolutegravir/ abacavir/lamivudine (DTG/3TC/ABC) after stratifying by VL and CD4 count. Clinical and analytical assessments were performed at weeks 0, 4, 12, 24, and 48. The primary endpoint was VL <50 c/mL at week 48 in the intention-to-treat (ITT)-exposed population (US Food and Drug Administration snapshot analysis, 10% noninferiority margin). Results. Between September 2018 and 2019, 316 patients were randomized and 306 patients were included in the ITT-exposed analysis (151 D/C/F/TAF and 155 DTG/3TC/ABC). Almost all (94%) participants were male and their median age was 35 years. Forty percent had a baseline VL >100 000 copies/mL, and 13% had <200 CD4 cells/μL. Median weight was 73 kg and median body mass index was 24 kg/m2 . At 48 weeks, 79% (D/C/F/TAF) versus 82% (DTG/3TC/ABC) had VL <50 c/mL (difference, −2.4%; 95% confidence interval [CI], −11.3 to 6.6). Eight percent versus four percent experienced virologic failure but no resistance-associated mutations emerged. Four percent versus six percent had drug discontinuation due to adverse events. In the per-protocol analysis, 94% versus 96% of patients had VL <50 c/mL (difference, −2%; 95% CI, −8.1 to 3.5). There were no differences in CD4 cell count or weight changes. Conclusions. We could not demonstrate the noninferiority of D/C/F/TAF relative to DTG/ABC/3TC as initial antiretroviral therapy, although both regimens were similarly well tolerated

Preparación, caracterización y estudio morfológico de fibras de carbón activado

Utilizando fibras de kenaf larga, se ha llevado a cabo la preparación, caracterización y estudio morfológico de las fibras de carbón activado (ACFs). La caracterización era realizada mediante las isotermas de adsorción de N2 a -196 C, porosimetría de Hg y microscopia electrónica de barrido. La activación a 700 ºC con CO2 durante 2h (FBC4A72) y 4 h (FBC4A74) de la muestra carbonizada a 400 ºC durante 0.5 h en N2 (FBC4), mostraban un incremento en el tamaño del poro, como se observa en las microscopías electrónica de barrido. Esto es probablemente debido a la interconexión de los poros como consecuencia del incremento del tiempo de tratamiento de 2 a 4h. Estos resultados abren un amplio campo de aplicación para las fibras de kenaf.Using kenaf as starting material, a study about the preparation and characterization of activated carbon fibers (ACFs) from long fibers was carried out. The carbonization products of kenaf fibers and ACFs were texturally characterized by N2 adsorption at -196 ºC, mercury porosimetry, and scanning electron microscopy. The activation of the raw material of Kenaf by its carbonization at 400 ºC for 0.5 h in a N2 atmosphere increase the porosity of the samples, particularly the activation at 700 ºC with carbon dioxide. It should be noted the porous development shown by the scanning electron micrographs of samples FBC4A72 and FBC4A74. It is observed that the variation of treatment time from 2 to 4 hours leads to an important development of the porous structure in samples FBC4A74, which is probably a consequence of an interconnection between pores. These results open a wide field of applications of these fibers.peerReviewe

Corrosion resistance of protective coatings against molten nitrate salts for thermal energy storage and their environmental impact in CSP technology

Sol-gel ZrO2–3%molY2O3 coating deposited by means of a dip-coating application on P91 steel was statically tested at 500 °C in contact with Solar Salt (60% wt.% NaNO3/40 wt.% of KNO3) for 1000 h. This work assessed the behaviour of the coated P91 steel both from a technical and environmental point of view. Both studies were compared to those obtained with AISI 304 steel, which is currently used in commercial CSP plants. In terms of corrosion evaluation, the behaviour of the coated P91 was directly comparable to that of the uncoated AISI 304, SEM micrographs revealing the better behaviour of coated samples and the maintenance of a compact coating layer, with a thickness ranging between 1 and 1.4 μm. Furthermore, environmental analyses revealed the environmental benefits obtained by using lower Cr-Ni content steel coated with ZrO2–Y2O3 compared to AISI 304 alloy, since this coating had a negligible environmental impact (its influence is below 0.03%). Thus, the proposed scenario seems to be workable in CSP high-temperature applications both from technical and environmental points of view. The linked technical-environmental quantification provided in this paper highlights the importance of considering the whole assessment when conducting material selection for CSP applications.Publicad

IFML-based Model-Driven Front-End Modernization

Since late 90’s the use of web application frameworks has been the default choice to develop software applications inside the web domain. In parallel, Model Driven Web Engineering approaches have been defined and successfully applied to reduce the effort of web application development and reuse, fostering the independence of the implementation technology. A direct result of the success of these approaches is the elaboration of the Interaction Flow Modeling Language (IFML) as an Object Management Group (OMG) standard. However, the real fact is that there is a huge amount of legacy web systems that were developed before MDWE approaches were mainstream. The work presented herein tries to leverage IFML to modernize the front-ends of framework-based legacy web applications. In concrete, a systematic model driven reverse engineering process to generate an IFML representation from such applications is presented

Impact of an enhanced screening program on the detection of non-AIDS neoplasias in patients with human immunodeficiency virus infection

Background The incidence of non-AIDS defining cancer (NADC) is higher in people living with HIV (PLWH) than in the general population, and it is already one of the leading causes of death in the HIV-infected population. It is estimated that the situation will be aggravated by the progressive aging of PLWH. Early diagnosis through intensive cancer screening may improve the ability for therapeutic interventions and could be critical in reducing mortality, but it might also increase expenditure and harms associated with adverse events. The aim of this study is to evaluate an enhanced screening program for early diagnosis of cancer in PLWH compared to standard practice. The specific objectives are (1) to compare the frequency of cancer diagnosed at an early stage, (2) to analyze safety of the enhanced program: adverse events and unnecessary interventions, (3) to analyze the cost-utility of the program, and (4) to estimate the overall and site-specific incidence of NADC in PLWH. Methods We will conduct a multicenter, non-blinded, randomized, controlled trial, comparing two parallel arms: conventional vs enhanced screening. Data will be recorded in an electronic data collection notebook. Conventional intervention group will follow the standard of care screening in the participating centers, according to the European AIDS Clinical Society recommendations, and the enhanced intervention group will follow an expanded screening aimed to early detection of lung, liver, anal, cervical, breast, prostate, colorectal, and skin cancer. The trial will be conducted within the framework of the Spanish AIDS Research Network Cohort (CoRIS). Discussion The trial will evaluate the efficacy, safety, and efficiency of an enhanced screening program for the early diagnosis of cancer in HIV patients compared to standard of care practice. The information provided will be relevant since there are currently no studies on expanded cancer screening strategies in patients with HIV, and available data estimating cost effectiveness or cost-utility of such as programs are scarce. An enhanced program for NADC screening in patients with HIV could lead to early diagnosis and improve the prognosis of these patients, with an acceptable rate of unnecessary interventions, but it is critical to demonstrate that the benefits clearly outweigh the harms, before the strategy could be implemented

El modelo Z2-Score de Altman como base para la discriminación del fracaso de los franquiciadores

En esta investigación se propone un método que permite a los potenciales franquiciados conocer si la probabilidad de fracaso del franquiciador es elevada o reducida. El objetivo principal de este estudio es obtener segmentos/clusters mediante la técnica de regresión de clases latentes, donde se analiza la relación entre las variables típicas de la franquicia y la solvencia de la empresa franquiciadora medida a través de la Z2-Score de Altman. Con el fin de identificar con claridad los segmentos y analizar las características que los definen, hemos utilizado como covariables: el sector, la facturación media y el personal de la empresa. Se han identificado ocho segmentos, de los cuales nos encontramos con cinco segmentos en los que las enseñas que lo componen son solventes, dos que están en zona gris y uno que es insolvente.This paper proposes a method that allows potential franchisees to know if the probability of failure of the franchisor is high or low. The main objective of this study is to obtain segments/clusters using the technique of latent class regression. Therefore, we analyze the relationship between the typical variables of the franchise and the solvency of the franchisor, measured by means of the Altman´s Z2-Score. In order to clearly identify segments and to analyze the characteristics that define them, we have used as covariates: the sector, the average turnover and the business employees. Eight segments have been identified: five of them show signs that make them solvent, two of them are in the grey area and one segment is insolvent