22 research outputs found
COMPARACIÓN DE POTENCIAL ENERGÉTICO DE MEZCLAS B5 Y B10 DE BIODIESEL OBTENIDO DE LA MACROALGA C. GLOMERATA CON DIESEL FÒSIL COMERCIAL
Cladophora glomerata es una macroalga muy abundante que crece en los ríos
de la región Arequipa. Presenta en sus células diferentes compuestos bio
activos como ácidos grasos, saturados, insaturados, esteroles, terpenos y
otros, que lo convierten en materia prima de gran utilidad para aplicaciones
alimenticias, farmacéuticas y puede ser explotado como biocombustible.
En la presente investigación se realizó el cultivo de Cladophora glomerata
encontrada en los pozos y canales de la central de generación eléctrica de
Arequipa (EGASA) para la obtención de biodiesel así como su comparación
energética en un motor diésel. Para el cultivo del alga Cladophora glomerata se
implementó y construyo un sistema de cultivo de flujo continuo a condiciones
ambientales (temperatura, pH y solidos totales, monitoreados semanalmente),
durante 4 semanas alcanzando una biomasa seca total de 2261,92g obtenido
de 37600 g de peso fresco, una productividad de 13,304.23 g.m-2 por semana y
una tasa de crecimiento a la cuarta semana de 112,5894 %/semana.
La extracción del aceite se realizó mediante el método de Soxhlet usando como
solventes cloroformo–metanol (2:1). El aceite total obtenido del alga
Cladophora glomerata fue 1900 ml que corresponde al 84% de la biomasa seca
total, presentando propiedades fisicoquímicas como el índice de yodo de 31,73
mol/gr, índice de refracción de 1,3705nD, índice de saponificación de 25,24,
aptas para la elaboración de biodiesel. Se implementó un sistema de reactor
para la tranesterificaciòn del aceite obtenido a biodiesel. El biodiesel total
obtenido de la biomasa de Cladophora glomerata durante un mes de cultivo fue
de 1580ml con una productividad de 83,16%.
El biodiesel obtenido de Cladophora glomerata presenta valores como
densidad de 0,8328 g/ml, punto de inflamación de 70,04ºC, cifra cetànica de
54,44. Acorde a la norma ASTM que regula la calidad de este tipo de
biocombustible.
En los ensayos que se realizaron en un motor petrolero de 4 cilindros con
cámara de combustión, el rendimiento del motor con las mezclas del Diésel con
Biodiesel al 5% (B5) y 10% (B10) tuvieron un menor gasto de combustible de
12,6551 Kg/hr y demostraron una diferencia mínima del 2% en la fuerza/torque
alcanzada para llegar a la misma velocidad (2200RPM), a diferencia del diésel
fósil convencional que obtuvo mayor gasto de combustible y una mayor fuerza.
Los resultados muestran a Cladophora glomerata como una macroalga
promisoria para la producción de biodiesel
Nueva metodología para el diseño rápido de sistemas de potabilización de agua en la enseñanza universitaria en Ingeniería ambiental
Globally, day-to-day sources of surface water resources endowed with qualities suitable for human consumption decrease resulting in conditions affecting communities dependent on these sources of this precious resource. Given the current situation, the most viable option to favor isolated or remote communities is through the construction of small potable water treatment plants (PTAP's) with fast and systematized design modules that allow obtaining the specifications for their construction and operation in a safe and sustainable way over time complying with SDG 6 (Agenda 2030, UN). Within this context, the design of systems for obtaining potable water becomes a valuable tool that allows the rapid configuration of this type of infrastructure to build efficient and completely sustainable systems in communities with low water resources. Currently, the teaching of this type of concepts and fundamentals are part of the curricula of programs and professional high schools education that teach the specialization in environmental engineering with a low level of computer science and systematization, declining its application due to its traditional management with tedious and slow calculations in obtaining results. Therefore, in this study a new learning dynamic is proposed using the 3D modeling software application for the study of real cases with practical application and immediate resolution allowing the full development of the critical capacity in the group of students who will use itA nivel mundial día a día las fuentes de recurso hídrico superficial dotadas con cualidades aptas para consumo humano disminuyen resultando en afecciones a comunidades dependientes de dichas fuentes de este preciado recurso. Dada la situación actual, la opción más viable para favorecer a comunidades aisladas o alejadas es mediante la construcción de pequeñas plantas de tratamiento de agua potable (PTAP´s) con módulos de diseño rápido y sistematizado que permita obtener las especificaciones para su construcción y operación en forma segura y sostenible con el tiempo cumpliendo con el ODS 6 (Agenda 2030, ONU). Dentro de este contexto, el diseño de sistemas para la obtención de agua potable se convierte en una herramienta valiosa que permite la configuración rápida de este tipo de infraestructura para levantar sistemas eficientes y completamente sostenibles en comunidades con escaso recurso hídrico. Actualmente, la enseñanza de este tipo de conceptos y fundamentos se encuadran en las curriculas de programas y escuelas profesionales a nivel universitario que imparten la especialización en ingeniería ambiental con escaso nivel informático y sistematizado decayendo en su aplicación por su manejo tradicional con cálculos tediosos y lentos en la obtención de resultados. Por ello en este estudio se propone una nueva dinámica de aprendizaje utilizando la aplicación de software de modelado 3D para el estudio de casos reales con aplicación práctica y resolución inmediata permitiendo el pleno desarrollo de la capacidad crítica en el grupo de alumnos que la utilizarán
Unpacking occupational health data in the service sector: From Bayesian networking and spatial clustering to policy-making
The health status of the service sector workforce is a significant unknown in the field of medical geography. While spatial epidemiology has made progress in predicting the relationship between human health and the environment, there are still important challenges that remain unsolved. The main issue lies in the inability to statistically determine and visually represent all spatial concepts, as there is a need to cover a wide range of service activities while also considering the impact of numerous traditional medical variables and emerging risk factors, such as those related to socioeconomic and bioclimatic factors. This study aims to address the needs of health professionals by defining, prioritizing, and visualizing multiple occupational health risk factors that contribute to the well-being of workers. To achieve this, a methodological approach based on the synergy of Bayesian machine learning and geostatistics is proposed. Extensive data from occupational health surveillance tests were collected in Spain, along with socioeconomic and bioclimatic covariates, to assess potential social and climate impacts on health. This integrated approach enabled the identification of relevant patterns related to risk factors. A three-step geostatistical modeling process, including variography, ordinary kriging, and G clustering, was used to generate national distribution maps for various factors such as annual mean temperature, annual rainfall, spine health, limb health, cholesterol, age, and sleep quality. These maps considered four target activities—administration, finances, education, and hospitality. Remarkably, bioclimatic variables were found to contribute approximately 9% to the overall health status of workersFundação para a Ciência e a Tecnologia | Ref. UIDB/00681/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/04683/2020Universidade de Vig
Growth and yield models in Spain: Historical overview, Contemporary Examples and perspectives
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Emulsion Polymerization of Isoprene: Mathematical Model for Long Chain Branching
For a batch emulsion polymerization of isoprene at 10 °C in the presence of a chain transfer agent, a previous mathematical model [Minari et al., J. Appl. Polym. Sci. 2010, 116, 590] was extended for predicting the molecular weight distributions of all the generated long-branched molecular topologies; with each topology characterized by the number of tri- and tetra-functional branches per molecule. At the reaction end, and according to the new model predictions, the linear topology remains as the most abundant (with approximate 50% of the total mass), followed by the single trifunctionally-branched topology (with approximate 20% of the total mass). The model can be useful for developing strategies for controlling the distribution of branches/molec., for estimating melt viscosities, etc.Fil: Rodriguez, Virginia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); ArgentinaFil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); ArgentinaFil: Estenoz, Diana Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); ArgentinaFil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); ArgentinaFil: Meira, Gregorio Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentin