Modeling of Chemical Oxygen Demand and Total Suspended Solids Removal Using the Fenton Process

Predictive mathematical models were developed for removing Chemical Oxygen Demand (COD) and Total Suspended Solids (TSS) and optimizing the main operating parameters of the Fenton process, applied to effluents from a fish canning industry. The maximum removals obtained for COD and TSS were 89.2 % and 76.1 %, respectively. The optimum doses for COD removal were: 200 mg/L FeSO4 7H2O and 1,000 mg/L H2O2 at pH 2.5. While for TSS removal the optimum parameters were 1 200 mg/L H2O2, 300 mg/L FeSO4 7H2O, and pH 3. The adjusted R2 values of the COD and TSS removal models were 70.64 % and 98.01 %, respectively, indicating that the models obtained are acceptable in the prediction of both parameters

Factors Associated with Mortality in Patients with COVID-19 from a Hospital in Northern Peru

We aimed to identify the factors associated with mortality in patients with COVID-19 from the hospitalization service of the Cayetano Heredia Hospital, Piura, Peru, from May to June 2020. A prospective study was conducted in hospitalized patients with a confirmed diagnosis of COVID-19 through serological and/or molecular reactive testing. The dependent variable was death due to COVID-19, and the independent variables were the epidemiological, clinical and laboratory characteristics of the patient. The chi-square test and the non-parametric Mann–Whitney U test were used, with a significance level of 5%. Of 301 patients with COVID-19, the majority of them were male (66.1%), and the mean age was 58.63 years. Of the patients analyzed, 41.3% of them died, 40.2% of them were obese and 59.8% of them had hepatic steatosis. The three most frequent signs/symptoms were dyspnea (90.03%), fatigue (90.03%) and a cough (84.72%). Being an older adult (p = 0.011), being hospitalized in the ICU (p = 0.001), overweight (p = 0.016), obese (p = 0.021) and having compromised consciousness (p = 0.039) and thrombocytopenia (p = 0.024) were associated with mortality due to COVID-19. Overall, the mortality rate due to COVID-19 was 41.3%. Having an older age, being hospitalized in the ICU, overweight, obese and having compromised consciousness and thrombocytopenia were positively associated with mortality in patients with COVID-19. These findings highlight the need to establish an adequate system of surveillance and epidemiological education in hospitals and communities in the event of new outbreaks, especially in rural and northern Peru

The bacterial community structure in an alkaline saline soil spiked with anthracene

Background: The application of polycyclic aromatic hydrocarbons (PAHs) will affect the bacterial community structure as some groups will be favoured and others not. An alkaline saline soil with electrolytic conductivity (EC) 56 dS m-1 was spiked with anthracene and acetone while their effect on bacterial community structure was investigated. Results: The percentages of Acidobacteria and Actinobacteria decreased over time, while the percentage of Proteobacteria, mostly Xanthomonadales, increased. The percentage of the phylotypes belonging to the Nocardioides , Rhodococcus and Streptomyces , known degraders of PAHs, was larger in the anthracene-amended soil than in the acetone-amended and unamended soil at day 14. The phylotypes belonging to the genera Sphingomonas , also a known degrader of PAHs, however, was lower. Weighted and unweighted PCoA with UniFrac indicated that phylotypes were similar in the different treatments at day 0, but changed at day 1. After 14 days, phylotypes in the unamended and acetone-amended soil were similar, but different from those in the anthracene-spiked soil. Conclusions: It was found that incubating the soil and contaminating it with anthracene changed the bacterial community structure, but spiking the soil with acetone had little or no effect on the bacterial community structure compared to the unamended soil

Genetic Programming Approach for the Detection of Mistletoe Based on UAV Multispectral Imagery in the Conservation Area of Mexico City

The mistletoe Phoradendron velutinum (P. velutinum) is a pest that spreads rapidly and uncontrollably in Mexican forests, becoming a serious problem since it is a cause of the decline of 23.3 million hectares of conifers and broadleaves in the country. The lack of adequate phytosanitary control has negative social, economic, and environmental impacts. However, pest management is a challenging task due to the difficulty of early detection for proper control of mistletoe infestations. Automating the detection of this pest is important due to its rapid spread and the high costs of field identification tasks. This paper presents a Genetic Programming (GP) approach for the automatic design of an algorithm to detect mistletoe using multispectral aerial images. Our study area is located in a conservation area of Mexico City, in the San Bartolo Ameyalco community. Images of 148 hectares were acquired by means of an Unmanned Aerial Vehicle (UAV) carrying a sensor sensitive to the R, G, B, red edge, and near-infrared bands, and with an average spatial resolution of less than 10 cm per pixel. As a result, it was possible to obtain an algorithm capable of classifying mistletoe P. velutinum at its flowering stage for the specific case of the study area in conservation area with an Overall Accuracy (OA) of 96% and a value of fitness function based on weighted Cohen’s Kappa (kw) equal to 0.45 in the test data set. Additionally, our method’s performance was compared with two traditional image classification methods; in the first, a classical spectral index, named Intensive Pigment Index of Structure 2 (SIPI2), was considered for the detection of P. velutinum. The second method considers the well-known Support Vector Machine classification algorithm (SVM). We also compare the accuracy of the best GP individual with two additional indices obtained during the solution analysis. According to our experimental results, our GP-based algorithm outperforms the results obtained by the aforementioned methods for the identification of P. velutinum

Estudio de nivel de aceptación de un producto lácteo tipo mantequilla enriquecido con algarrobina

El consumo de mantequilla se asocia a un elevado contenido de grasa saturada y reducido en aporte en vitaminas. El objetivo del presente estudio fue formular un producto lácteo tipo mantequilla enriquecida con algarrobina y evaluar su nivel de aceptación por parte de los consumidores, así como sus características fisicoquímicas y microbiológicas. Se empleó un diseño con tres tratamientos (concentración de 11%, 13% y 15% de algarrobina) y se sometió a evaluación sensorial aplicando una prueba hedónica para conocer el nivel de aceptación. Participaron en el estudio 60 panelistas consumidores habituales de mantequilla. Se realizó el análisis fisicoquímico para conocer su composición de acuerdo a las normas establecidas por la A.O.C (2005) así como el análisis microbiológico empleando la técnica del número más probable. Se observaron que las muestras que contienen el 15% de algarrobina fueron más aceptados con respecto al color, olor, sabor y textura que las muestras que contienen 11% y 13 de sustitución de este dulce. Se concluye que a mayor adición de algarrobina en un producto lácteo del tipo de mantequilla sin superar el 15% de sustitución, goza de la aceptación por parte del consumidor

Estudio de nivel de aceptación de un producto lácteo tipo mantequilla enriquecido con algarrobina

El consumo de mantequilla se asocia a un elevado contenido de grasa saturada y reducido en aporte en vitaminas. El objetivo del presente estudio fue formular un producto lácteo tipo mantequilla enriquecida con algarrobina y evaluar su nivel de aceptación por parte de los consumidores, así como sus características fisicoquímicas y microbiológicas. Se empleó un diseño con tres tratamientos (concentración de 11%, 13% y 15% de algarrobina) y se sometió a evaluación sensorial aplicando una prueba hedónica para conocer el nivel de aceptación. Participaron en el estudio 60 panelistas consumidores habituales de mantequilla. Se realizó el análisis fisicoquímico para conocer su composición de acuerdo a las normas establecidas por la A.O.C (2005) así como el análisis microbiológico empleando la técnica del número más probable. Se observaron que las muestras que contienen el 15% de algarrobina fueron más aceptados con respecto al color, olor, sabor y textura que las muestras que contienen 11% y 13 de sustitución de este dulce. Se concluye que a mayor adición de algarrobina en un producto lácteo del tipo de mantequilla sin superar el 15% de sustitución, goza de la aceptación por parte del consumidor

Multi-level numerical modelling and analysis of tile vaults

The complex structural behaviour of masonry, with its brittle response in tension, frictional response in shear, and anisotropy, makes it challenging to model accurately. Tile vaults, with their unique features such as different binders and bricks placed flat, have distinctive structural performance, and determining the most suitable assessment method is still a subject of debate in both academic and professional circles. This paper presents a study on the structural analysis of tile vaults, aiming at evaluating different numerical approaches for this type of structure. The examination of these approaches and their effectiveness in capturing the structural behaviour of tile vaults intends to offer valuable insights to researchers and professionals in this field. Experimental research was initially carried out in order to provide data for the calibration of the structural models. Two full-scale vaults were tested. Furthermore, several material characterization tests were also performed. The numerical assessment was carried out through limit analysis and non-linear static analysis with numerical models based on the Finite Element Method (FEM). Two FEM models were prepared using different modelling approaches for masonry, namely the macro-modelling and the simplified micro-modelling approaches. The results of the limit analysis presented a load capacity significantly lower than the ultimate load obtained from the experimental tests. The calibrated FEM models presented good results in comparison to the experimental results, namely in terms of damage pattern and load capacity.This research, together with the APC, were funded by the Swiss National Science Foundation (“Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung”), grant number P2EZP2_181591. This work was supported by the FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020, and under the Associate Laboratory Advanced Production and Intelligent Systems ARISE under reference LA/P/0112/2020