A new LED-LED portable CO2 gas sensor based on an interchangeable membrane system for industrial applications

A new system for CO2 measurement (0-100%) by based on a paired emitter-detector diode arrangement as a colorimetric detection system is described. Two different configurations were tested: configuration 1 (an opposite side configuration) where a secondary inner-filter effect accounts for CO2 sensitivity. This configuration involves the absorption of the phosphorescence emitted from a CO2-insensitive luminophore by an acid-base indicator and configuration 2 wherein the membrane containing the luminophore is removed, simplifying the sensing membrane that now only contains the acid-base indicator. In addition, two different instrumental configurations have been studied, using a paired emitter-detector diode system, consisting of two LEDs wherein one is used as the light source (emitter) and the other is used in reverse bias mode as the light detector. The first configuration uses a green LED as emitter and a red LED as detector, whereas in the second case two identical red LEDs are used as emitter and detector. The system was characterised in terms of sensitivity, dynamic response, reproducibility, stability and temperature influence. We found that configuration 2 presented a better CO2 response in terms of sensitivity

Influencia del PET reciclado en las propiedades físico-mecánicas de adoquines elaborados con agregados de la cantera Río Bado de Huamachuco

La presente tesis trata sobre la influencia del PET reciclado en las propiedades físico – mecánicas de adoquines. Tomando como objetivo, determinar la influencia en las propiedades físico – mecánicas de adoquines elaborados con PET reciclado al 4% y 8%. Proponiendo este plástico como agregado. La metodología de la investigación es aplicada y experimental, mediante la cual se evaluó las propiedades físico – mecánicas, bajo las normativas de la norma técnica peruana NTP 399.611, el Manual de Ensayo de Materiales RD N° 18 – 2016 – MTC/14 y la Norma ACI 211. Referenciando las normas del Manual de ensayos de materiales, se realizó la caracterización de los agregados, donde se obtuvieron los valores de 0.31% de humedad natural en la piedra y 0.96% en arena; dando como 3/4"" el TNM y 2.40 el módulo de finura. También se realizó el peso unitario suelto y compactado para la piedra, siendo 1364 kg/m3 y 1665 kg/m3 , mientras que la arena 1522 kg/m3 y 1797 kg/m3 respectivamente; finalizando por el peso específico y porcentaje de absorción de la piedra, siendo de 2.46 y 1.04%, mientras que la arena 2.82 y 2.21%. Habiendo realizado la caracterización de agregados, se realizó el diseño de mezcla según el ACI 211 donde se obtuvo a/c = 0.45. Seleccionamos especímenes prismáticos de 20cmx10cmx6cm para la realización de todos los ensayos, resistencia a la compresión, según NTP 399.064; resistencia a la flexión, según la NTG 41087 y Ensayo de porcentaje de absorción, según ASTM C 140. Considerando que todos los adoquines superan f’c = 320 kg/cm2 , cumpliendo con lo estipulado en la NTP 399.611. Por último, evaluamos los resultados mediante tablas y gráficos comparativos de los valores a compresión, flexión y absorción de todos los especímenes (patrón, patrón + 4% y patrón + 8% de PET reciclado) ensayados a los 7, 14 y 28 días. Tomando como referencia el adoquín patrón para los ensayos de resistencia a la flexiónThis thesis deals with the influence of recycled PET on the physical mechanical properties of paving stones. Taking as objective to determine the influence on the physical-mechanical properties of pavers made with recycled PET at 4% and 8%. Proposing this plastic as an aggregate. The methodology of the research is applied and experimental, through which the physical-mechanical properties were evaluated, under the regulations of the Peruvian technical standard NTP 399.611, the Materials Testing Manual RD N° 18 – 2016 – MTC / 14 and the ACI 211 Standard. Referencing the standards of the Material Testing Manual, the characterization of the aggregates was carried out, where the values of 0.31% of natural humidity in the stone and 0.96% in sand were obtained; giving as 3/4"" the TNM and 2.40 the fineness modulus. The loose and compacted unit weight for the stone was also made, being 1364 kg / m3 and 1665 kg / m3, while the sand 1522 kg / m3 and 1797 kg / m3 respectively; ending by the specific weight and percentage of absorption of the stone, being 2.46 and 1.04%, while the sand 2.82 and 2.21%. Having performed the characterization of aggregates, the mixture design was carried out according to ACI 211 where a / c = 0.45 was obtained. We selected prismatic specimens of 20cmx10cmx6cm for the performance of all tests, compressive strength, according to NTP 399,064; flexural strength, according to NTG 41087 and Absorption percentage test, according to ASTM C 140. Considering that all pavers exceed f'c = 320 kg / cm2, complying with the provisions of NTP 399.611. Finally, we evaluated the results through comparative tables and graphs of the compression, bending and absorption values of all specimens (pattern, pattern + 4% and pattern + 8% recycled PET) tested at 7, 14 and 28 days. Taking as reference the standard paving stone for flexural strength testsTesi

Diseño de edificios multifamiliares para mejorar el déficit de vivienda de los sectores poblacionales emergentes, distrito Ica - 2022

La investigación desarrollada tuvo como objetivo identificar los criterios para diseñar espacios de integración e infraestructura de una vivienda digna y acorde a las necesidades de expansión y planificación de la ciudad de Ica en el año 2022, así como encaminarse hacia un desarrollo urbano sostenible, cuyo proceso de investigación se justifica en el enfoque cualitativo y diseño de investigación fenomenológico. Se basó en fundamentos teóricos respectivamente por cada categoría, como Villa Verde por Aravena, que estipulaba que en la medida que pudiésemos desarrollar una tipología innovadora y competitiva estaríamos contribuyendo a ampliar el potencial dentro del ámbito de la contribución al problema actual de vivienda; Conjunto Residencial San Felipe por Ciriani, cuya obra arquitectónica de gran envergadura es considerada un proyecto insignia, que además de embellecer el urbanismo de la zona en donde está emplazado, plantea un fluido y mayor juego de formas, que crea un vínculo entre arte y ciudad, con intervenciones que brindan bienestar, Unidad Vecinal N°3 por Belaunde, que intento definir una urbe dominada por la alta densidad con el fin de abaratar costos en cuanto a servicios públicos invirtiendo menos, y a su vez planteaba el crecimiento planificado de la ciudad moderna concibiendo un barrio socialmente homogéneo, dotado de servicios sociales y con áreas verdes. Se utilizó como participantes equipamientos y especialista en el tema tratado, y la dimensión de la muestra fue por muestreo no probabilístico y por criterio de los investigadores. La validez del instrumento se consiguió a través de un juicio de expertos. La recopilación de datos se consiguió mediante la guía de entrevistas y ficha de observación entre 8 y 15 ítems correspondientes por cada categoría. El análisis de los datos fue interpretado de manera estructurada según la información expresada, llegando a identificar los criterios para diseñar espacios de integración e infraestructura de una vivienda digna y acorde a las necesidades de expansión y planificación de la ciudad de Ica en el año 2022, que son el aspecto económico y social que contribuyen a un correcto desarrollo de vivienda social

Liver Biomarkers and Lipid Profiles in Mexican and Mexican-American 10- to 14-Year-Old Adolescents at Risk for Type 2 Diabetes

Proyecto de investigación que describe la presencia de diversos factores de riesgo para desarrollar diabetes mellitus tipo 2 en adolescentes.Liver enzymes alanine aminotransferase (ALT) and gamma glutamyl transferase (GGT) are markers for type 2 diabetes mellitus (T2DM); alkaline phosphatase is a marker of liver disease. Mexican-American adolescents are disproportionately affected by T2DM, while in Mexico its prevalence is emerging. We assessed liver biomarkers and lipid profiles among Mexican and Mexican-American adolescents 10–14 years old with high/low risk of T2DM through a cross-sectional, descriptive study (Texas n = 144; Mexico n = 149). We included family medical histories, anthropometry, and blood pressure. Obesity was present in one-third of subjects in both sites. ALT (UL) was higher (p < 0 001) in high-risk adolescents (23.5 ± 19.5 versus 17.2 ± 13.4 for males, 19.7 ± 11.6 versus 15.1 ± 5.5 for females), in Toluca and in Texas (26.0 ± 14.7 versus 20.0 ± 13.2 for males, 18.2 ± 13.4 versus 14.6 ± 10.1 for females), as well as GGT (UL) (p < 0 001) (18.7 ± 11.1 versus 12.4 ± 2.3 for males, 13.6 ± 5.8 versus 11.5 ± 3.9 for Mexican females; 21.0 ± 6.8 versus 15.4 ± 5.5 for males, 14.3 ± 5.0 versus 13.8 ± 5.3 for females in Texas). We found no differences by sex or BMI. Total cholesterol and HDL were higher among Mexican-Americans (p < 0 001). In conclusion, multiple risk factors were present in the sample. We found differences by gender and between high and low risk for T2DM adolescents in all liver enzymes in both sites.Fondo Semilla UAEM-UNTHS

A new LED-LED portable CO2 gas sensor based on an interchangeable membrane system for industrial applications

CO2 monitoring is important for many areas of high economic relevance, like environmental monitoring, control of biotechnological processes in bio-pharmaceutical industries, and the food industry, particularly controlled atmosphere storage rooms and modified atmosphere packaging [ ]. CO2 sensing is not a trivial area of research, as is testified by the increasing numbers of publications regarding this topic over the past decade. The main reason is that CO2 chemically is relatively unreactive, and therefore finding a mechanism for signal generation is difficult. Most publications are based on its well-known acidic properties. In this communication, we present a portable optical sensor for gaseous CO2 detection based on the phosphorescence intensity variation of a platinum octaethylporphyrin (PtOEP) complex trapped in oxygen-insensitive poly(vinylidene chloride-co-vinyl chloride) (PVCD) membranes. The sensing mechanism arises from the increasing displacement of the α-naphtholphthalein acid–base equilibrium with rising CO2 concentrations [ ]. The low-power LED-based optical sensing instrumentation for monitoring CO2 is based on a pair of light emitting diodes (LEDs) arranged to face each other, wherein one LED functions as the light source and the other LED is reverse biased to function as a light detector [ ]. A transparent polymer substrate coated on both sides with the CO2 sensitive membrane placed between the two LEDs serves as a chemically responsive filter between the light source and the detector

Compreendendo a Importância das Competências Docentes na Educação a Distância: um olhar sobre um Curso Superior de Tecnologia

Este artigo analisa o grau das competências necessárias para a atuação docente na modalidade educacional a distância e aponta quais podem ser aprimoradas para o seu exercício laboral, em uma instituição de ensino superior ofertante de cursos na modalidade. A pesquisa envolve a participação de atores envolvidos com a modalidade que possuem interação com os docentes atuantes. A pesquisa define-se como de natureza descritiva com caráter de estudo de caso. Os instrumentos de coleta são questionários com questões de múltipla escolha, documentos, observação direta e bibliografias. O método de investigação possui delineamento quali-quantitativo e as análises de dados foram realizadas abordando: análise interpretativa e análise estatística de dados. Os resultados indicam que os resultados apresentados podem ser potencializados com aprimoramentos dos docentes acerca das competências técnicas, relacionadas ao domínio pedagógico e domínio comunicativo, e das competências comportamentais, relacionadas ao domínio técnico e domínio pedagógico

Standardised inventories of spiders (Arachnida, Araneae) on touristic trails of the native forests of the Azores (Portugal)

Background The sharp increase in tourist visitation of the Azores Archipelago from 2015 onwards raised concerns about the impacts of recreational tourism on native habitats. In response, a project was financed by the Azorean Government to investigate the drivers of biodiversity erosion associated with recreational tourism. Here, we present the data on spider biodiversity found on trails located within the native Azorean forests as they are home to several endemic species of great conservation value. We applied an optimised and standardised sampling protocol (COBRA) in twenty-three plots located in five trails on Terceira and Sao Miguel Islands and assessed diversity and abundance of spider species at different distances from the trail head and the trail itself. New information Of the 45 species (12435 specimens) collected, 13 were endemic to the Azores (9690 specimens), 10 native non-endemic (2047 specimens) and 22 introduced (698 specimens). This database will be the baseline of a long-term monitoring project for the assessment of touristic impacts on native forest trails. This methodology can also be used on other habitats and biogeograhical regions.Peer reviewe

Safety and efficacy of bentonite as a feed additive for all animal species

The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) received a request from the European Commission to assess the safety and efficacy of bentonite when used as a technological feed additive (substances for reduction of the contamination of feed by mycotoxins) for all animal species. The applicant, EUBA aisbl (European Bentonite Association) representing six companies, submitted to EFSA a technical dossier to support the application. The applicant proposes to use bentonite at the maximum level of 20,000 mg/kg complete feed. The additive apparently interferes with the analysis of aflatoxin B1 in feed. The safety of the additive was already evaluated by the Panel in an opinion delivered in 2012. Bentonites are safe for all animal species, the consumers and the environment when used at a maximum level of 20,000 mg/kg complete feed. The results of a new genotoxicity study reinforced the previous conclusion that smectites are non-genotoxic. Bentonites are not skin irritants but might be mildly irritant to the eye; based on a new study submitted, the additive is not a skin sensitiser. Owing to its silica content, the additive is a hazard by inhalation for the users. The in vitro study showed that the di- and tri-octahedral smectites tested can adsorb aflatoxin B1 at different concentrations and at pH 5; however, no adequate in vivo studies were available. Therefore, the Panel cannot draw conclusions on the additive\u2019s efficacy. The Panel further considers the safety and efficacy conclusions to apply equally to the di- and tri-octahedral smectites under assessment. The FEEDAP Panel posted some recommendations regarding the maximum content of other minerals in the additive and the incompatibilities of the additive with other medicinal substances. The Panel also drew a remark concerning the denomination of the additive and the current regulatory definition of Bentonite

Climatic control on the Holocene hydrology of a playa-lake system in the western Mediterranean

Evaporitic lakes such as playa-lakes are characteristic of many arid regions and are unique environments with respect to fauna and flora, while being very vulnerable to climate and environmental fluctuations and threatened by the current global change scenario. Water balance oscillations in these systems can trigger the precipitation or dissolution of different evaporitic minerals, negatively impacting local biodiversity and economic activities. Here, we study the sedimentary record of a small saline pond from a playa-lake complex in southwestern Iberia in order to reconstruct the paleohydrological evolution of this area and assess potential anthropogenic disturbances. The different proxies studied in the-11.9 ky old sedimentary record of the Laguna de la Ballestera suggest that the greatest lake extension and the highest water levels occurred during the Early Holocene, pointing to the wettest period of the record. Climate transitioned towards more arid conditions during the Middle Holocene, and even more dramatically during the Late Holocene. In this last stage the wetland surface and the water level largely diminished and gypsum precipitation gradually increased pointing towards a negative precipitation/ evapotranspiration balance and lowest water levels. Summer desiccation likely occurred under this scenario, especially after-1.0-0.9 cal ky BP coeval with the Medieval Climate Anomaly, when gypsum content started to rise abruptly. However, this significant gypsum precipitation was only associated with a massive drop in the siliciclastic content and scarce carbonates (dolomite and calcite) during the last-400 years. This evidence suggests a shift from a (semi) permanent to a temporal/seasonal hydrological regime. The environmental evolution of this wetland responded to the general climatic evolution of the western Mediterranean during the Holocene, being mostly controlled by changes in insolation. Our data also show that the environmental response of the studied wetland to natural climate variations was only significantly disturbed by human activities since the 20th century, especially in the second half of the century, deduced by abrupt fluctuations in the siliciclastic, gypsum and organic content in the sediments, as well as by the enhanced sedimentary accumulation rates, probably as a response to changes in the hydroperiod of the lake and in the catchment land use.Peer reviewe

Role of light chain clearance in the recovery of renal function in multiple myeloma: another point of view

Lay Summary This is a retrospective multicenter study that evaluated the effectiveness of intensive haemodialysis (IHD) vs standards dialysis on renal recovery in patients with acute kidney injury (AKI) associated with myeloma multiple (MM). In this paper, we demonstrated that IHD for early light chain reduction was associated with a better renal prognosis. Another finding is the importance of maintenance diuresis as a marker of good prognosis of renal function. To our knowledge few studies have been focused in the comparison between IHD vs standard dialysis in MM patients with AKI. We consider that if we manage to recover the renal function, we achieve a great clinical impact since the patient with chronic kidney disease and especially in hemodialysis, an increased risk of mortality as well as poorer quality of life. Background Acute kidney injury (AKI) in patients with multiple myeloma (MM) requiring renal replacement treatment (RRT) is associated with high morbidity and mortality. Early reduction of serum free light chains (FLC) using both targeted therapy against MM and intensive hemodialysis (IHD) may improve renal outcomes. We evaluated the effectiveness of two different RRT techniques on renal recovery in an MM patient population: standard dialysis procedure vs IHD with either polymethylmethacrylate (PMMA) or hemodiafiltration with endogenous reinfusion (HFR). Methods This was a multicentric retrospective study with severe AKI related to MM, between 2011 and 2018. Twenty-five consecutive patients with AKI secondary to MM requiring RRT were included. Patients that underwent IHD received six dialysis sessions per week during the first 14 days (PMMA vs HFR). All patients were diagnosed with de novo MM or first relapsed MM. Primary outcome was renal recovery defined as dialysis-free at 6 months follow-up. Results A total of 25 patients were included. Seventeen patients received IHD and eight standard dialysis. All patients were treated with targeted therapy, 84% bortezomib-based. Of the 25 patients included, 14 (56%) became dialysis independent. We observed a higher proportion of patients who received IHD in the group who recovered kidney function compared with those who remained in HD (92.9% vs 36.4%, P = .007). In our study, the use of IHD to remove FLC had a statistically significant association with renal recovery compared with the standard dialysis group (P = .024). Conclusion Early reduction of FLC with IHD as an adjuvant treatment along with MM-targeted therapy may exert a positive impact on renal recovery