Elucidating the Role of the Metal Catalyst and Oxide Support in the Ru/CeO2-Catalyzed CO2 Methanation Mechanism.

This study addresses the yet unresolved CO2 methanation mechanism on a Ru/CeO2 catalyst by means of near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) complemented with periodic density functional theory (DFT) calculations. NAP-XPS results show that the switch from H2 to CO2 + H2 mixture oxidizes both the Ru and CeO2 phases at low temperatures, which is explained by the CO2 adsorption modes assessed by means of DFT on each representative surface. CO2 adsorption on Ru is dissociative and moderately endergonic, leading to polybonded Ru-carbonyl groups whose hydrogenation is the rate-determining step in the overall process. Unlike on Ru metal, CO2 can be strongly adsorbed as carbonates on ceria surface oxygen sites or on the reduced ceria at oxygen vacancies as carboxylates (CO2 -δ), resulting in the reoxidation of ceria. Carboxylates can then evolve as CO, which is released either via direct splitting at relatively low temperatures or through stable formate species at higher temperatures. DRIFTS confirm the great stability of formates, whose depletion relates with CO2 conversion in the reaction cell, while carbonates remain on the surface up to higher temperatures. CO generation on ceria serves as an additional reservoir of Ru-carbonyls, cooperating to the overall CO2 methanation process. Altogether, this study highlights the noninnocent role of the ceria support in the performance of Ru/CeO2 toward CO2 methanation.

Mineral Manganese Oxides as Oxidation Catalysts: Capabilities in the CO-PROX Reaction.

Cryptomelane is an abundant mineral manganese oxide with unique physicochemical features. This work investigates the real capabilities of cryptomelane as an oxidation catalyst. In particular, the preferential CO oxidation (CO-PROX), has been studied as a simple reaction model. When doped with copper, the cryptomelane-based material has revealed a great potential, displaying a comparable activity to the high-performance CuO/CeO2. Despite stability concerns that compromise the primary catalyst reusability, CuO/cryptomelane is particularly robust in the presence of CO2 and H2O, typical components of realistic CO-PROX streams. The CO-PROX reaction mechanism has been assessed by means of isotopic oxygen pulse experiments. Altogether, CuO/CeO2 shows a greater oxygen lability, which facilitates lattice oxygen enrolment in the CO-PROX mechanism. In the case of CuO/cryptomelane, in spite of its lower oxygen mobility, the intrinsic structural water co-assists as active oxygen species involved in CO-PROX. Thus, the presence of moisture in the reaction stream turns out to be beneficial for the stability of the cryptomelane structure, besides aiding into the active oxygen restitution in the catalyst. Overall, this study proves that CuO/cryptomelane is a promising competitor to CuO/CeO2 in CO-PROX technology, whose implementation can bring the CO-PROX technology and H2 purification processes a more sustainable nature.

Divulgación de la experiencia de un modelo de utilidad de transferencia, apropiación y adopción tecnológica de siembra bajo invernadero en productores rurales caso: El Edén de Cris del corregimiento de La Elvira del municipio de Cali / Dissemination of the experience of a utility model of transfer, appropriation and technological adoption of seeding under greenhouse in rural producers: Case El Eden de Cris del corregimiento de La Elvira del municipio de Cali / Divulgação da experiência de um modelo de utilidade de transferência, apropriação e adoção tecnológica de plantio sob estufa em produtores rurais: Caso O Éden de Cris do correção de La Elvira do município de Cali

Resumen El artículo muestra los resultados del estudio cuyo propósito es divulgar la experiencia de la transferencia y apropiación tecnológica del modelo de utilidad en la siembra bajo invernadero mediante la aplicación de la metodología investigación social, caso El Edén de Cris, corregimiento de La Elvira, período 2012 - 2016. Los resultados revelan que al aplicar la metodología en el proyecto, se logró la transferencia tecnológica, la apropiación y adopción de siembra bajo invernadero por medio de un modelo de utilidad; sin embargo, la continuidad del proyecto involucrando más productores agrícolas generaría un impacto socioeconómico en la localidad. El modelo de utilidad permitió aplicar nuevas formas de producción agrícola a través de las Unidades Productivas Agrícolas Sostenibles, la réplica a más productores podría contribuir a disminuir las brechas de exclusión social e inequidad existentes en la localidad de la Elvira, reconfigurar el territorio a partir del diseño de un micro-circuito productivo sostenible con el agroecosistema, mediante la construcción social de relaciones productivas en redes de productores rurales. Clasificación JEL: F18, J43, L83, 013, Q57

Abstract This article shows the results of the study whose purpose is to disseminate the experience of the transfer and technological appropriation of the utility model in greenhouse sowing through the application of the social research methodology. El Edén de Cris case, corregimiento of the Elvira, period 2012 - 2016. The results revealsthat when applying the methodology in the project, the technological tranfer appropriation and adoption of sowing under greenhouse was achieved through a utility model; however the continuity of the project involving more agricultural producers would generate a socioeconomic impact in the town.The utility model allowed the application of new forms of agricultural production through the Sustainable Agricultural Productive Units, the replication of more producers could contribute to reducing the gaps of social exclusion and inequality existing in the town of Elvira, reconfiguring the territory from design of a sustainable productive micro-circuit with agroecosystems, through the social construction of forms of productive relations in networks of rural producers. JEL Classification: F18, J43, L83, 013, Q57

Resumo O artigo apresenta os resultados do estudo, cujo objetivo é disseminar a experiência da transferência e apropriação tecnológica do modelo de utilidade na semeadura em estufa através da aplicação da metodologia de pesquisa social, caso El Edén de Cris, corregimiento (é usado na Colômbia para definir um tipo de subdivisão da área rural dos diferentes municípios do país) de La Elvira, período de 2012 - 2016. Os resultados revelam que, ao aplicar a metodologia no projeto, a transferência tecnológica, a apropriação e a adoção da semeadura em casa de vegetação foram realizadas por meio de um modelo de utilidade; no entanto, a continuidade do projeto envolvendo mais produtores agrícolas geraria um impacto socioeconómico na localidade. O modelo de utilidade permitiu a aplicação de novas formas de produção agrícola por meio das Unidades Produtivas Agrícolas Sustentáveis, a replicação de mais produtores poderia contribuir para reduzir as lacunas de exclusão social e desigualdade existentes no corregimiento de La Elvira, reconfigurando o território de projeto de um microcircuito produtivo sustentável com agroecossistemas, através da construção social de relações Produtivas Em Redes De Produtores Rurais. Classificações JEL: F18, J43, L83, 013, Q57

Resultados de las 100 primeras colecistectomías por puerto único en un hospital de segundo nivel / Results of the first 100 single port laparoscopic cholecystectomies in a secondary care hospital

INTRODUCCIÓN: Aunque los resultados de la colecistectomía laparoscópica estándar son excelentes, se continúa intentando minimizar el número de puertos con el objeto de disminuir el dolor postoperatorio, conseguir una recuperación más temprana y mejorar el resultado estético del paciente. El objetivo de este estudio es presentar los resultados de los primeros 100 casos de colecistectomía por puerto único practicados en un hospital de segundo nivel. MATERIAL Y MÉTODOS: Estudio prospectivo, observacional, unicéntrico. Se intervino a 100 pacientes entre enero de 2010 y abril de 2012. CRITERIOS DE INCLUSIÓN: pacientes mayores de 16 años con colelitiasis sintomática operados por colecistectomía simple mediante incisión umbilical única. Criterios de exclusión: antecedentes de colecistitis aguda, colangiopancreatografía retrógrada endoscópica, pancreatitis o sospecha de coledocolitiasis, IMC > 35 y laparotomías previas. Se estudiaron distintas variables epidemiológicas, quirúrgicas y de seguridad. RESULTADOS: La edad media de los pacientes fue de 39,89 ± 11,5 años. El tiempo quirúrgico medio fue de 67,94 ± 25,5 min. Presentaron complicaciones postoperatorias 2 pacientes: seroma y fuga biliar. En 2 casos fue necesaria la utilización de trocar accesorio. La estancia media fue de 1,13 ± 0,8 días. El 35% de los pacientes fueron tratados en régimen de cirugía mayor ambulatoria. Todos los pacientes se mostraron muy satisfechos con el resultado estético. CONCLUSIONES: La colecistectomía mediante incisión umbilical única es una buena técnica cuando se utiliza en casos seleccionados y por cirujanos expertos. Puede facilitar la práctica de la colecistectomía en régimen ambulatorio. No se han presentado complicaciones graves. El índice de satisfacción estética es muy elevado

INTRODUCTION: Despite the excellent results obtained with standard laparoscopic cholecystectomy, the efforts for minimizing the ports needed to reduce postoperative pain, for a quicker recovery and to improve the patient's cosmetics continue. The aim of this study is to report the results of the first 100 cases of single port laparoscopic cholecystectomy performed in a secondary care hospital. MATERIAL AND METHODS: Prospective, observational and unicentric study including 100 patients between January 2010 and April 2012. Inclusion criteria: symptomatic cholelythiasis patients over 16 years of age on whom a single port laparoscopic cholecystectomy was performed. Exclusion criteria: history of acute cholecystitis, pancreatitis or suspected choledocholithiasis, Endoscopic retrograde cholangiopancreatography, BMI > 35 and previous laparotomies. We studied epidemiological, surgical and safety variables. RESULTS: The mean patient age was 39.89 ± 11.5 years. The mean time of the surgical procedure was 67.94 ± 25.5 min. There were 2 cases of postoperative complications: a non-infected seroma and a biliar leak. In 2 cases the use of an accessory trocar was needed. The mean hospital stay was 1.13 ± 0.8 days. A total of 35% patients were included in the major ambulatory surgery program. The overall patient satisfaction survey rating showed a high level of cosmetic satisfaction in 100% of patients. CONCLUSIONS: Single port laparoscopic cholecystectomy is a good technique when performed in selected cases by expert surgeons. It is feasible to include the single port laparoscopic cholecystectomy in a major ambulatory surgery program. We have not had serious complications. There is a high cosmetic satisfaction index with this technique

Results of the first 100 single port laparoscopic cholecystectomies in a secondary care hospital.

INTRODUCTION: Despite the excellent results obtained with standard laparoscopic cholecystectomy, the efforts for minimizing the ports needed to reduce postoperative pain, for a quicker recovery and to improve the patient's cosmetics continue. The aim of this study is to report the results of the first 100 cases of single port laparoscopic cholecystectomy performed in a secondary care hospital. MATERIAL AND METHODS: Prospective, observational and unicentric study including 100 patients between January 2010 and April 2012. INCLUSION CRITERIA: symptomatic cholelythiasis patients over 16-years of age on whom a single port laparoscopic cholecystectomy was performed. EXCLUSION CRITERIA: history of acute cholecystitis, pancreatitis or suspected choledocholithiasis, Endoscopic retrograde cholangiopancreatography, BMI>35 and previous laparotomies. We studied epidemiological, surgical and safety variables. RESULTS: The mean patient age was 39,89 ± 11,5 years. The mean time of the surgical procedure was 67,94 ± 25,5 min. There were 2 cases of postoperative complications. A non-infected seroma and a biliar leak. In 2 cases the use of an accessory trocar was needed. The mean hospital stay was 1,13 ± 0,8 days. A total of 35% patients were included in the major ambulatory surgery programme.The overall patient satisfaction survey rating showed a high level of cosmetic satisfaction in 100% of patients. CONCLUSIONS: Single port laparoscopic cholecystectomy is a good technique when performed in selected cases by expert surgeons. It is feasible to include the single port laparoscopic cholecystectomy in a major ambulatory surgery programme. We have not had serious complications. There is a high cosmetic satisfaction index with this technique.