Preparation of granular activated carbons from grape seeds by cycles of liquid phase oxidation and thermal desorption

Activation of grape seed char upon successive cycles of liquid phase oxidation followed by high temperature desorption permits a tailored development of porosity. In this work three different oxidants (HNO3, H 2O2, and (NH4)2S2O 8), have been tested and the desorption temperature has been varied within 850-950 C upon 10 activation cycles. A high increase of BET surface area was observed in the first five cycles with HNO3 as oxidizing agent giving rise to values higher than 1200 m2 g- 1 at around 50% burn-off. Activation with H2O2 and (NH 4)2S2O8 led to a significantly lower development of surface area, with 600 and 800 m2 g- 1 respectively at that burn-off. The analysis of the pore size distribution showed that porosity was generated through the creation of new micropores and widening of existing ones upon activation with HNO3 and (NH4) 2S2O8, whereas H2O2 mostly led to the widening of the narrow micropores already existing in the starting char. The activated carbons obtained are essentially microporous, with some small contribution of mesoporosity in the HNO3 series (V micro = 0.69 cm3 g- 1; Vmeso = 0.07 cm3 g- 1). SEM images showed that the activated carbons maintained the granular morphology of the seeds after 10 cycles showing a hollow core structure with a wall thickness of about 200 μmThe authors greatly appreciate the financial support from the Spanish Ministerio de Ciencia e Innovación (CTQ2009-09983

Granular mesoporous activated carbons from waste tires by cyclic oxygen chemisorption-desorption

This document is the accepted manuscript version of a published work that appeared in final form in Industrial and Engineering Chemistry Research, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/ie201499hActivation upon cyclic oxygen chemisorption-desorption has proved to be an efficient way to develop porosity at low burn off from waste tires char. In this work the influence of particle size, desorption temperature, and the number of cycles is studied. Highest values of burnoff and specific surface area (S BET) are obtained for the largest particle diameter (3 mm average) and at intermediate desorption temperature (650 °C). In these conditions S BET values around 500 m 2/g can be achieved at burn-offs of about 30%, and close to 600 m 2/g at around 45% burnoff, with a mean pore size of 10 nm and a micropore volume close to 0.08 cm 3/g. Although the surface area is moderate, the low burnoff and high S BET/burnoff ratio achieved make it possible to maintain initial granular morphology of the particles even after 20 cycles of activationWe greatly appreciate finantial support from the Spanish Ministerio de Educacion y Ciencia through the project CTQ2009-0998

Activation of waste tire char by cyclic liquid-phase oxidation

Activation of waste tire char was performed by successive cycles of liquid-phase oxidation followed by desorption in inert atmosphere at 650 °C. Significant differences in porosity development were found for the three oxidizing agents evaluated: nitric acid > hydrogen peroxide > ammonium persulfate. A linear increase of burn-off with the number of cycles was observed, reaching values between 63 and 90% after 15 activation cycles. Within the range tested, a higher concentration of the oxidizing agent (15 vs 30% v) led to higher burn-off, especially in the case of H2O2, however no differences were observed in terms of BET surface area (S BET) developed per unit of burn-off. SBET values around 750-400 m2/g were obtained by activation with HNO3 and H2O2, respectively. The activated carbons prepared by activation with HNO3 showed much higher mesopore volume (0.47-0.60 cm3/g) and some contribution of microporosity (0.03-15 cm 3/g). The mesopore size distribution in the samples activated with HNO3 (2-7 nm) was displaced to lower values than in the case of H2O2 (4-10 nm). The comparison with cyclic activation with air shows that liquid-phase oxidation provides higher porosity development, especially in the mesopore region but at the expense of higher burn-offThe authors greatly appreciate financial support from the Spanish Ministerio de Ciencia e Innovación (CTQ2009-09983) and the Ministerio de Economía y Competitividad (CTQ2012-32821

Ozone as oxidation agent in cyclic activation of biochar

Granular activated carbons were produced from grape seed biochar by cyclic activation with ozone. In each cycle, char was first oxidized by exposure to ozone and then subjected to high temperature in inert atmosphere to desorb oxygen groups formed. The study assessed the influence of operating conditions in the development of porosity, from a starting biochar with narrow microporosity (SBET: 47 m2 g− 1, SDA: 505 m2g− 1) prepared by flash pyrolysis of grape seed at 800 °C. The variables studied were the number of cycles applied and the oxidation and desorption temperatures (250–275 and 850–950 °C, respectively). High oxidation temperatures led to higher burn-off, which was also found to increase with the number of activation cycles. The burn-off needed to achieve a high surface area was lower than in conventional physical activation. After 7–9 activation cycles, activated carbons with SBET higher than 1200 m2 g− 1 and SDA above 1500 m2 g− 1 were obtained. The use of ozone resulted in mainly microporous activated carbons (0.37–0.52 cm3 g− 1) with very low contribution of mesopores (< 0.04–0.07 cm3 g− 1). The mean micropore size increased with the number of activation cycles due to pore widening, while mesopore mean size decreased along the cycles. The activated carbons showed a unique granular morphology with a hollow core and a porous shell, which is maintained even after 10 activation cyclesThe authors greatly appreciatefinancial support from the Spanish Ministerio de Ciencia e Innovación (CTQ2012-32821

Porous structure and morphology of granular chars from flash and conventional pyrolysis of grape seeds

This work studies the influence of the operating conditions used in the pyrolysis of grape seeds on the morphology and textural properties of the chars resulting. Flash and conventional (283Kmin-1 heating rate) pyrolysis have been used within a wide range of temperature (300-1000°C). The effect of a pretreatment for oil extraction has also been studied. The porous structure of the chars was characterized by adsorption of N2 at 77K, Ar at 77K and 87K, and CO2 at 273K and mercury intrusion porosimetry. The morphology was analyzed by scanning electron microscopy. All the materials prepared revealed an essentially microporous structure, with a poor or even negligible contribution of mesopores. Increasing pyrolysis temperature led to higher specific surface areas and lower pore size. The highest specific surface area values occurred within 700-800°C, reaching up to 500m2g-1 with pore sizes in the 0.4-1.1nm range. No significant morphological changes were observed upon carbonization so that the resulting chars were granular materials of similar size than the starting grape seeds. The hollow core structure of the chars, with most of the material allocated at the periphery of the granules can help to overcome the mass transfer limitations of most common (solid or massive) granular activated carbons. The chars showed a good mechanical strength during attrition tests. These chars can be potential candidates for the preparation of granular carbons molecular sieve or activated carbons raw materialsThe authors greatly appreciate financial support from the Spanish Ministerio de Ciencia e Innovación (CTQ2009-09983

Intrauterine infusion of platelet-rich plasma for severe Asherman syndrome: a cutting-edge approach

Asherman syndrome (AS) consists of intrauterine adhesions development as a consequence of trauma, radiation, or infection in the endometrium. Clinical symptoms include menstrual alterations, infertility, and pregnancy complications, such as recurrent pregnancy loss or abnormal placentation. In this article, we performed a narrative review of the literature, searching electronic databases (i.e., Medline, Pubmed, and Google Scholar) to summarize the available pieces of evidence about epidemiology, pathophysiology, diagnosis, and treatment of AS. Hysteroscopy is essential for diagnosis and treatment, although adhesions may recur. Different postoperative therapies have been proposed to prevent recurrence and restore impaired endometrial function and promote endometrial regeneration, although these effects are usually temporary. We report a case of AS with adhesion recurrence and endometrial atrophy who was successfully treated with intrauterine autologous platelet–rich plasma (PRP) infusion. This therapy allowed endometrial tissue regeneration, leading to increased vascularity and endometrium thickness, and restoration of endometrial function that led to a successful pregnancy. Though there is limited experience supporting the use of PRP to improve endometrial function, it has been safely used in other fields of medicine; besides, it is easy to obtain, not expensive, and harmless being an autologous source. Future studies are encouraged to further assess this approach to treat AS

Finite-element-model updating of civil engineering structures using a hybrid UKF-HS algorithm

This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this recordFinite-element-model updating allows reducing the discrepancies between the numerical and the experimental dynamic behaviour of civil engineering structures. Among the different methods to tackle the updating problem, the maximum likelihood method has been widely used for practical engineering applications. In this method, the updating problem is transformed into an optimization problem where the relative differences between the numerical and experimental modal properties of the structure are reduced via the modification of the most relevant physical parameters of the model. However, this method often presents the drawback of requiring high simulation times in order to perform the updating process when dealing with complex structures. To overcome this limitation, in this paper a novel hybrid Unscented Kalman Filter – Harmony Search (UKF-HS) algorithm is proposed and its implementation details are discussed. In order to validate such hybrid algorithm and further illustrate its performance, the finite-element-model updating of a benchmark footbridge is performed using two different approaches (single-objective and multi-objective) and three different computational algorithms, namely: (i) genetic algorithms; (ii) harmony search; and (iii) the novel UKF-HS hybrid algorithm. The obtained results reveal that the proposed hybrid algorithm may be considered as an adequate alternative tool to efficiently perform the finite-element-mMinisterio de Economía y Competitividad of SpainEuropean Regional Development Fund (ERDF)Universidad de Sevill

Durvalumab plus tremelimumab for the treatment of advanced neuroendocrine neoplasms of gastroenteropancreatic and lung origin

Single immune checkpoint blockade has shown limited activity in patients with neuroendocrine neoplasms (NENs). Here the authors report the results of a phase II clinical trial of durvalumab (anti-PD-L1) and tremelimumab (anti CTLA-4) in patients with advanced NENs of gastroenteropancreatic and lung origin. Single immune checkpoint blockade in advanced neuroendocrine neoplasms (NENs) shows limited efficacy; dual checkpoint blockade may improve treatment activity. Dune (NCT03095274) is a non-randomized controlled multicohort phase II clinical trial evaluating durvalumab plus tremelimumab activity and safety in advanced NENs. This study included 123 patients presenting between 2017 and 2019 with typical/atypical lung carcinoids (Cohort 1), G1/2 gastrointestinal (Cohort 2), G1/2 pancreatic (Cohort 3) and G3 gastroenteropancreatic (GEP) (Cohort 4) NENs; who progressed to standard therapies. Patients received 1500 mg durvalumab and 75 mg tremelimumab for up to 13 and 4 cycles (every 4 weeks), respectively. The primary objective was the 9-month clinical benefit rate (CBR) for cohorts 1-3 and 9-month overall survival (OS) rate for Cohort 4. Secondary endpoints included objective response rate, duration of response, progression-free survival according to irRECIST, overall survival, and safety. Correlation of PD-L1 expression with efficacy was exploratory. The 9-month CBR was 25.9%/35.5%/25% for Cohorts 1, 2, and 3 respectively. The 9-month OS rate for Cohort 4 was 36.1%, surpassing the futility threshold. Benefit in Cohort 4 was observed regardless of differentiation and Ki67 levels. PD-L1 combined scores did not correlate with treatment activity. Safety profile was consistent with that of prior studies. In conclusion, durvalumab plus tremelimumab is safe in NENs and shows modest survival benefit in G3 GEP-NENs; with one-third of these patients experiencing a prolonged OS

Instituto Internacional de Investigaci ́on e Innovaci ́on del Envejecimiento

El Instituto Internacional de Investigaci on e Innovaci on del Envejecimiento es un proyecto transfronterizo y multidisciplinar centrado en la mejora de la calidad de vida de los ancianos mediante el uso de la tecnolog a. En este proyecto colaboran la Universidad de Evora, el Instituto Polit ecnico de Porto Alegre, el Instituto Polit ecnico de Beja, la Administraci on Regional de Salud de Alentejo y la Universidad de Extremadura. Los objetivos del proyecto se centran en comprender los aspectos biom edicos, funcionales y psicol ogicos del envejecimiento; generar nuevos modelos y procesos de cuidado a ancianos y desarrollar soluciones tecnol ogicas que contribuyan a la salud y calidad de vida de los ancianos y a la sostenibilidad de los servicios

Biomass-Derived Microporous Carbon Materials with an Open Structure of Cross-Linked Sub-microfibers with Enhanced Adsorption Characteristics

This document is the accepted manuscript version of a published work that appeared in final form in Energy and Fuels, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/abs/10.1021/acs.energyfuels.6b02112Moringa oleifera seed shells exhibit a unique structure of cross-linked sub-microfibers (0.5-1.5 μm diameter) with a well-connected macroporous network. Controlled pyrolysis (500-800 °C) and cyclic activation of the precursor provided a porous carbon material with a structure that minimizes mass-transfer constraints. Under both slow (10 °C/min-1) and flash pyrolysis, the structure was preserved, while a significant microporosity was developed. By flash pyrolysis (700-800 °C), a material with enhanced characteristics for potential application as a molecular sieve (SDA = 450-470 m2 g-1, and SBET = 5 m2 g-1) was obtained. Cyclic activation of carbonized shells, consisting of an oxygen chemisorption stage (180 °C) followed by a desorption stage in an inert atmosphere (450-900 °C), resulted in a controlled development of microporosity upon successive activation cycles. After 10 activation cycles, respective SDA and SBET values of 1172 and 761 m2 g-1 were obtained. Higher development of the surface area and a wider distribution of micropores was observed when the desorption stage was carried out at 900 °C. The development of the surface area was achieved at low burnoff (22-33%), thus preserving the structure of the material. Thanks to its unique structure, the material obtained exhibited enhanced characteristics for gas sorption as a result of diminished mass-transfer limitations, assessed through the kinetics of carbon dioxide adsorption runs at ambient conditionsThe authors greatly appreciate financial support from the Spanish Ministerio de Economía y Competitividad (CTQ2012-32821