Abstract The objective of this work was to produce activated carbon from the agricultural waste known as pineapple stubble and to test its effectiveness in the removal of methylene blue and surfactants. Activated carbon was prepared using ZnCl2 and H3PO4 as activating agents and impregnation ratios of 2: 1 and 4:1 between the agent (mL) and the precursor (g) were evaluated. It was also investigated the need or not of a drying stage prior to carbonization. The produced activated carbon was characterized through FT-IR spectroscopy, X-ray fluorescence, N2 physisorption analysis, elemental analysis, and electron microscopy. Methylene blue adsorption tests were performed to determine the adsorption effectiveness of the different activated carbons produced. For such evaluation, a 23 factorial design was used, and statistical analysis determined that the activated carbon with the highest adsorption of methylene is produced under the following conditions: ZnCl2 as an activating agent, an impregnation ratio of 4:1, and with no drying step prior to carbonization. This produced activated carbon is also effective in the adsorption of the surfactant sodium dodecyl sulfate and for the surfactants present in the gray water obtained after washing clothes with commercial detergent. In these cases, removal efficiencies above 98 % were achieved. Concerning the characteristics of this activated carbon, it was observed a surface area of 685.5 m2/g, a total pore volume of 0.53 cm3/g, and an average pore diameter of 3.1 nm. Results achieved in the present study demonstrate that is possible to produce effective activated carbon for the removal of methylene blue and surfactants from agricultural waste such as pineapple stubble.

RESUMEN Introducción: Uno de los parámetros más importantes asociados a la producción de leche y su transformación es contar con condiciones higiénico-sanitarias adecuadas que permitan mejorar las condiciones del productor y empresas transformadoras y, por ende, garantizar inocuidad alimentaria al consumidor garantizando su bienestar y salud. Objetivo: Se evaluaron características composicionales, microbiológicas y sanitarias de leche cruda durante el segundo tercio de lactancia en vacas lecheras. Materiales y métodos: Se tomaron muestras de leche por duplicado cada 10 días a siete vacas lecheras durante su segundo tercio de lactancia. Posteriormente, se realizaron las siguientes pruebas: análisis composicional, adulterantes, presencia de antibióticos, recuento de células somáticas (RCS/ ml), identificación de Staphylococcus aureus y antibiograma por el método de Kirby-Bauer. Resultados: Se detectó la presencia de Staphylococcus aureus en el 66,2% de las muestras y 4,6% resultaron positivas para Listeria sp. No hubo presencia de antibióticos, peróxidos y almidones. Se evidenciaron muestras positivas para cloruros y neutralizantes, además se determinó que por cada kilogramo de leche se obtiene 30, 25 y 84 g de proteína, caseína y sólidos no grasos (SNG), respectivamente; donde la caseína representó el 83% de la proteína. Para el caso del RCS/ml se encontraron valores superiores a un millón de RCS/ml. Conclusiones: Para el caso estudiado la calidad composicional, sanitaria y microbiológica de la leche cruda en el segundo tercio de lactancia en vacas lecheras no es adecuada debido a que se obtuvieron valores que sobrepasan algunos lineamientos de la Norma Técnica Colombiana (NTC) 399 de 2002, en la cual se establece un conteo de mesófilos y de células somáticas (RCS/ml) máximo de 700.000/ml de leche cruda, a partir del cual se debe descartar el consumo de leche o su transformación.

ABSTRACT Introduction: One of the most important parameters associated with the production of milk and its transformation, is to have adequate hygienic-sanitary conditions in terms of milk quality that allow improving the conditions of the producer and processing companies, and therefore to provide food safety to the consumers, guaranteeing their well-being and health. Objetive: Compositional, microbiological and sanitary characteristics of raw milk were evaluated during the second third of lactation in dairy cows. Materials and methods: Two milk samples were taken every 10 days from 7 dairy cows during their second third of lactation. Then the following tests were carried out: compositional analysis, adulterants, presence of antibiotics, somatic cell count (SCC/mL), identification of Staphylococcus aureus and antibiogram by the Kirby-Bauer method. Results: Staphylococcus aureus was evidenced in 66.2% of the samples, and 4.6% of them gave positive for Listeria sp. No traces of antibiotics, peroxides and starches were found. Positive samples were found for chlorides and neutralizers, and it was determined that for each kilogram of milk, 30, 25 and 84 grams of protein, casein and non-fatty solids (NFS) were obtained, with 83% of the protein formed by casein. In the case of SCC/mL, values higher than one million SCC/mL were found. Conclusions: The compositional, sanitary and microbiological quality of the studied raw milk in the second third of lactation in dairy cows was not adequate, because values found lied above the Colombian technical standard 399 of 2002, which establishes a maximum of mesophile and somatic cell count (SCC/ mL) of 700000/ml in raw milk, therefore not allowing its consumption and transformation.

El acceso a imágenes fuera del espectro visible ha abierto grandes posibilidades para la caracterización de procesos y materiales en muchas áreas de la actividad humana; particularmente, las termografías son notablemente útiles en el estudio del comportamiento de los fenómenos de propagación del calor; en este caso, los análisis se han limitado a verificar distribuciones de calor en un momento dado y solo estáticamente. El enlace temporal de las isotermas y de los centros de generación del calor permite obtener información de carácter dinámico y realizar análisis más completos sobre el comportamiento de los equipos o materiales bajo estudio. En este trabajo se presentan los resultados de aplicar técnicas de análisis de secuencias de imágenes a termografías de diferentes procesos; se demuestra que con ellas se logra un entendimiento más preciso del comportamiento del calor al circular por los objetos, de cómo sus fuentes y sumideros asimilan diferentes condiciones y de la evolución general de flujos constantes o variables de perfiles de temperatura.

Access to images out of visible spectrum range has opened a wide field of possibilities for processes and material characterization in many areas of human activity. Thermography is particularly useful in analyzing the behavior of heat propagation phenomena. In this case, the analysis has been limited to verify the heat distribution at a given time, it means, the static aspect of the phenomena. The temporary connection of isotherms and heat generation areas can yield dynamic information that enables a more comprehensive analysis of equipment or materials behavior of interest. This paper presents the results obtained from the application of analytical techniques in different processes of some image sequences. The results show that it achieves a more precise understanding of the heat behavior circulation through the objects, it also reveals how sources and sinks assimilate the different conditions and the temperature profiles trends of constant or variable flow's general evolution.

Dental caries and periodontal disease are associated with oral pathogens. Several plant derivatives have been evaluated with respect to their antimicrobial effects against such pathogenic microorganisms. Lippia sidoides Cham (Verbenaceae), popularly known as "Alecrim-pimenta" is a typical shrub commonly found in the Northeast of Brazil. Many plant species belonging to the genus Lippia yield very fragrant essential oils of potential economic value which are used by the industry for the commercial production of perfumes, creams, lotions, and deodorants. Since the leaves of L. sidoides are also extensively used in popular medicine for the treatment of skin wounds and cuts, the objective of the present study was to evaluate the composition and antimicrobial activity of L. sidoides essential oil. The essential oil was obtained by hydro-distillation and analyzed by GC-MS. Twelve compounds were characterized, having as major constituents thymol (56.7%) and carvacrol (16.7%). The antimicrobial activity of the oil and the major components was tested against cariogenic bacterial species of the genus Streptococcus as well as Candida albicans using the broth dilution and disk diffusion assays. The essential oil and its major components thymol and carvacrol exhibited potent antimicrobial activity against the organisms tested with minimum inhibitory concentrations ranging from 0.625 to 10.0 mg/mL. The most sensitive microorganisms were C. albicans and Streptococcus mutans. The essential oil of L. sidoides and its major components exert promising antimicrobial effects against oral pathogens and suggest its likely usefulness to combat oral microbial growth.