Impact of Anaerobic Biofilm Formation on Sorption Characteristics of Powdered Activated Carbon

Subsurface contamination by petroleum hydrocarbons (PHCs) results from the leakage of petroleum products during extraction, processing or transport. It has been documented that activated carbon (AC) can effectively sorb organic compounds present in water. As a result, the use of carbon-based injectates (CBI) has gained popularity for use to treat groundwater impacted with PHCs in situ. CBI relies on the dynamic equilibrium between sorption, desorption and biodegradation of contaminants, leading to long-term treatment. The aim of this study was to investigate the influence of biofilm formation on the sorption characteristics of PHCs to powdered activated carbon (PAC). Specifically, the sorption performance of PAC for toluene was evaluated before and after an anaerobic methanogenic toluene-degrading microbial biofilm was developed on the PAC. Batch microcosm experiments were used to grow a biofilm on PAC surfaces (bio-coated PAC). The microbial culture used in the microcosm experiments actively degraded toluene as demonstrated by toluene reduction and the methane production. Confocal microscopy was conducted for qualitative visualization and quantitative analysis of the biofilms. The biofilm continually developed on the PAC surfaces and increased its mass and thickness over the 180-day long experimental period. The sorption characteristics of PAC without biofilm formation (fresh PAC) were compared to PAC samples removed from microcosms at Day 80 and Day 180. The change of sorption characteristics of PAC was evaluated based on best fit Freundlich isotherm parameters (Kf and nf). The value of Kf was reduced from 79.8 for fresh PAC to 50.2 and 47.7 for Day 80 and Day 180 bio-coated PAC, respectively. An increase in nf from 0.35 for fresh PAC to 0.42 for bio-coated PAC at Day 80 and 180 was also observed. These results show that the sorption performance of PAC was reduced when a microbial biofilm was developed. Although the biofilm growth was significant between Day 80 and Day 180, and a slight decrease in Kf was obtained for the bio-coated PAC at Day 180 compared to Day 80, the observed growth did not yield a statistically significant difference in the loss of sorption capacity between both time points. A simulated PAC barrier was used to demonstrate the iv impact that biofilm formation could have on potential performance deterioration. The biocoated PAC barrier performance was evaluated based on the percent reduction of breakthrough time as a function of incoming contaminant concentration. The breakthrough performance was found to deteriorate with the biofilm formation, with a greater impact at lower incoming concentrations (e.g., 60% reduction in breakthrough time for a concentration of 10 μg/L). The results of this study revealed that the sorption performance of PAC could be hampered by biofilm formation leading to fouling the AC pores (by biomass production and/or sorption of microbial by-products) which may affect its long-term effectiveness

Aplicación del Ciclo Deming para optimizar el tiempo de atención en la Empresa Gestión e Ingeniería E&C Chimbote, 2022

En la presente investigación se tuvo como objetivo principal “Implementar el Ciclo Deming para optimizar el tiempo de atención en la Empresa Gestión e Ingeniería E&C Chimbote, 2022”, además de emplear una metodología cuantitativa, de tipo aplicada, de diseño pre experimental y transversal, conformada por una muestra de 60 órdenes de servicios y la totalidad de trabajadores de la empresa Gestión e Ingeniería E&C Chimbote, empleando como instrumento un cuestionario y la hoja de registro de tiempo, por ello, la investigación obtuvo como resultado que la aplicación del Ciclo Deming optimiza el tiempo de atención de las instalaciones a gas domiciliario con un nivel de significancia de p=0,038 menor a (α =.05), concluyendo en que se rechaza la Ho y se acepta la hipótesis Hi, que establece que, la aplicación del Ciclo Deming optimiza el tiempo de atención en la empresa Gestión e Ingeniería E&C Chimbote, 2022

Las 5 eses y satisfacción laboral en el Colegio Cristiano Elliot Trujilo-2022

La investigación tuvo como objetivo determinar la relación de las 5 eses y la satisfacción laboral del Colegio Cristiano Elliot Trujillo-2022. Se empleó el programa de SPSS V21 para su procesamiento. La investigación es de tipo aplicada, de diseño no experimental, de corte trasversal y descriptiva. La población estuvo constituida por todos los colaboradores del Colegio. La técnica que se utilizo fue la encuesta, el cuestionario tuvo 19 preguntas. Para la segunda variable se utilizó un cuestionario de 9 preguntas. Esta variable fue medida desde la perspectiva de los colaboradores. Luego del análisis de la primera variable el resultado tiene un nivel regular debido a que los colaboradores consideran que a los materiales y equipos solamente se utilizan en ocasiones particulares. La correlación de Rho de Spearman, con el valor de 0.528, indica que existe una correlación positiva regular entre la variable 5 eses y Satisfacción Laboral. El valor de ρ > 0.05; lo que permite afirmar que la relación es significativa, es por ello que la hipótesis es aceptada

Effect of Na and the back contact on Cu2Zn(Sn,Ge)Se4 thin-film solar cells : towards semi-transparent solar cells

Cu2ZnSn1-xGexSe4 (CZTGSe) thin films have been grown onto Mo/SLG and Mo/V2O5/FTO/SLG substrates using thermal co-evaporation followed by a subsequent thermal annealing. A NaF precursor layer was evaporated prior to the deposition of the kesterite absorber layer. In the samples grown on Mo/SLG, it has been found that Na promotes Ge incorporation into the Cu2ZnSnSe4 lattice. The high concentration of incorporated Ge leads to the segregation of Sn-Se secondar y phases as we l l as to an accumulation of Sn next to the Mo layer. The use of 12 and 16 nm NaF thick precursor layers prior to the CZTGSe deposition leads to absorber band gaps of 1.30 and 1.34 eV, and to device performances of 4.7 and 4.0%, respectively. A higher Na content, furthermore, caused the formation of bigger grains, a higher charge carrier concentration and a shorter depletion width. A 12 nm NaF precursor layer was used for the devices grown on FTO-based substrates, producing an optimal back contact that allows achieving efficiencies of 5.6% and transmittance of 30% in the near infrared range. This enhanced performance can be associated with the absence of secondary phases and Ge distribution through the absorber layer. The formation of a MoSe2 layer at the back interface in al l the investigated devices seems to play a crucial role to improve the solar cell efficiency

Experience with tocilizumab in severe COVID-19 pneumonia after 80 days of follow-up: A retrospective cohort study

Objectives: To describe the clinical characteristics and predictors of major outcomes in patients treated with tocilizumab (TCZ) for severe COVID-19 pneumonia.Patients and methods: Case series of all sequential patients with severe COVID-19 pneumonia treated with TCZ at an Academic Spanish hospital (March 12 - May 2, 2020). Clinical outcomes: death, length of hospital stay. An early clinical response to TCZ (48-72 h after the administration) was assessed by variations in respiratory function markers, Brescia COVID Respiratory Severity Scale (BCRSS), inflammatory parameters, and patients' and physicians' opinion. Associations were tested by multiple logistic regression.Results: From a cohort of 236 patients, 77 patients treated with TCZ were included (median age 62 years (IQR 53.0-72.0), 64.9% were males), 42.9% had Charlson index ≥3; hypertension (41.6%), obesity (34.7%), and diabetes (20.8%). Median follow-up was 83.0 days (78.0-86.5), no patient was readmitted. ICU admission was required for 42 (54.5%), invasive mechanical ventilation in 38 (49.4%) and 10 patients died (12.9% global, 23.8% at ICU admitted). After multivariate adjustment, TCZ response by BCRSS (OR 0.03 (0.01-0.68), p = 0.028), and Charlson index (OR 3.54 (1.20-10.44), p = 0.022) has been identified as independent factors associated with mortality. Median of hospital stay was 16.0 days (11.0-23.0); BCRSS, physician subjective and D-dimer response were associated with shorter hospitalization stay.Conclusions: In a Mediterranean cohort, use of tocilizumab for severe COVID-19 show 12.9% of mortality. Early TCZ-response by BCRSS and low comorbidity were associated with increased survival. Early TCZ-response was related to shorter median hospital stay

Laboratory Hyperspectral Image Acquisition System Setup and Validation

Hyperspectral Imaging (HSI) techniques have demonstrated potential to provide useful information in a broad set of applications in different domains, from precision agriculture to environmental science. A first step in the preparation of the algorithms to be employed outdoors starts at a laboratory level, capturing a high amount of samples to be analysed and processed in order to extract the necessary information about the spectral characteristics of the studied samples in the most precise way. In this article, a custom-made scanning system for hyperspectral image acquisition is described. Commercially available components have been carefully selected in order to be integrated into a flexible infrastructure able to obtain data from any Generic Interface for Cameras (GenICam) compliant devices using the gigabyte Ethernet interface. The entire setup has been tested using the Specim FX hyperspectral series (FX10 and FX17) and a Graphical User Interface (GUI) has been developed in order to control the individual components and visualise data. Morphological analysis, spectral response and optical aberration of these pushbroom-type hyperspectral cameras have been evaluated prior to the validation of the whole system with different plastic samples for which spectral signatures are extracted and compared with well-known spectral libraries.Laboratory Hyperspectral Image Acquisition System Setup and ValidationpublishedVersio

Methodologies for Housing Justice Resource Guide

This Resource Guide is the outcome of a Summer Institute on Methodologies for Housing Justice convened by the Institute on Inequality and Democracy at UCLA Luskin as part of the Housing Justice in Unequal Cities Network, which is supported by the National Science Foundation (BCS 1758774). Held in Los Angeles in August 2019, the Summer Institute brought together participants from cities around the world. As is the case with the overall scope and purpose of the Housing Justice in Unequal Cities Network, it created a shared terrain of scholarship for movement-based and university-based scholars. Dissatisfied with the canonical methods that are in use in housing studies and guided by housing justice movements that are active research communities, the Summer Institute was premised on the assertion that methodology is political. Methodology is rooted in arguments about the world and involves relations of power and knowledge. The method itself – be it countermapping or people’s diaries – does not ensure an ethics of solidarity and a purpose of justice. Such goals require methodologies for liberation. Thus, as is evident in this Resource Guide, our endeavor foregrounds innovative methods that are being used by researchers across academia and activism and explicitly situates such methods in an orientation towards housing justice

Challenges associated with biomarker-based classification systems for Alzheimer's disease

Altres ajuts: This work was also supported by research grants from the Carlos III Institute of Health, Spain and the CIBERNED program (Program 1, Alzheimer Disease to Alberto Lleó and SIGNAL study, www.signalstudy.es), partly funded by Fondo Europeo de Desarrollo Regional (FEDER), Unión Europea, "Una manera de hacer Europa". This work has also been supported by a "Marató TV3" grant (20141210 to Juan Fortea and 044412 to Rafael Blesa) and by Generalitat de Catalunya and a grant from the Fundació Bancaria La Caixa to Rafael Blesa. I. Illán-Gala is supported by the i-PFIS grant from the FIS, Instituto de Salud Carlos III and the Rio Hortega grant (CM17/00074) from "Acción estratégica en Salud 2013-2016" and the European Social Fund. USPHS NIH grants awarded to M.J.d.L. include: AG13616, AG022374, AG12101, and AG057570.We aimed to evaluate the consistency of the A/T/N classification system. We included healthy controls, mild cognitive impairment, and dementia patients from Alzheimer's disease Neuroimaging Initiative. We assessed subject classification consistency with different biomarker combinations and the agreement and correlation between biomarkers. Subject classification discordance ranged from 12.2% to 44.5% in the whole sample; 17.3%-46.4% in healthy controls; 11.9%-46.5% in mild cognitive impairment, and 1%-35.7% in dementia patients. Amyloid, but not neurodegeneration biomarkers, showed good agreement both in the whole sample and in the clinical subgroups. Amyloid biomarkers were correlated in the whole sample, but not along the Alzheimer's disease continuum (as defined by a positive amyloid positron emission tomography). Neurodegeneration biomarkers were poorly correlated both in the whole sample and along the Alzheimer's disease continuum. The relationship between biomarkers was stage-dependent. Our findings suggest that the current A/T/N classification system does not achieve the required consistency to be used in the clinical setting