Deposition of spray droplets by four spray nozzles and two working pressures

The deposition of spray droplets on the target can be influenced by the type spray nozzle used, as well as the employed working pressure. Thus, with the commercial availability of new spray nozzles, performance studies with the new models become necessary. This study was carried out to evaluate ground deposition of spray droplets by four models of spray nozzles, at two working pressures. The experiment was conducted in Dourados/MS, in September 2020, with strip design and 4x2 factorial scheme, with five repetitions. Four spray nozzles were used (single flat fan, ST-IA 02 model; angle flat fan MUG 02; hollow cone MGA 02; and double flat fan ST-IA/D 02), working at 30 and 50 psi pressures. The distance between each nozzle was 50 cm, 60 cm above the ground. Water-sensitive paper was used and, immediately after application, the paper was scanned using the DropScan® tool. Subsequently, the number of droplets, coverage, amplitude, dispersion,      Volume Median Diameter (VMD), Number Median Diameter (NMD), DV09, and DV01 were evaluated. The hollow cone spray nozzle provided a higher number of droplets and greater coverage compared to the other nozzles for the studied weather conditions

Duccio Bonavia Berber y la Arqueología Peruana

En los comienzos del siglo xx, la Arqueología se definía como una disciplina humanista, ubicada dentro de la Antropología y las Ciencias Sociales. A la Arqueología le correspondía el estudio de la cultura material de los pueblos antiguos, un poco para parafrasear el título del libro de Melville Herskovits (1974) “El Hombre y sus Obras”, uno de los primeros alumnos de Franz Boas. En la Arqueología Andina, además de esta ya tradicional perspectiva, se observa la influencia de la corriente histó..

Evaluación del impacto del Programa de Capacitación de Educación Preventiva del uso indebido de sustancias psicoactivas en las actitudes de docentes de educación secundaria de menores

En: Revista de Psicología, Vol. 2, No.1En una muestra de 860 profesores de Educación Secundaria de Menores de las diversas especialidades, a nivel nacional, se realizó un estudio de la efectividad del programa de capacitación de educación preventiva del uso indebido de drogas en términos del cambio de actitudes, considerando las variables tiempo de participación en el programa, lugar geográfico, sexo, edad y tiempo de servicios. Se elaboraron dos instrumentos: una ficha de datos generales y una escala de actitudes hacia la docencia y las drogas, desarrollada en base a la revisión de la Escala de Actitudes de Minnessota. Se hallaron diferencias significativas en función al tiempo de participación en el programa y región geográfica como variables principales. El sexo sólo influyó como variable aislada y la edad, al combinarse con tiempo de capacitación. Los años de experiencia docente no constituyeron una variable relevante

The missing link of Rodinia breakup in western South America: A petrographical, geochemical, and zircon Pb-Hf isotope study of the volcanosedimentary Chilla beds (Altiplano, Bolivia)

The assembly of Rodinia involved the collision of eastern Laurentia with southwestern Amazonia at ca. 1 Ga. The tectonostratigraphic record of the central Andes records a gap of ∼300 m.y. between 1000 Ma and 700 Ma, i.e., from the beginning of the Neoproterozoic Era to the youngest part of the Cryogenian Period. This gap encompasses the time of final assembly and breakup of the Rodinia supercontinent in this region. We present new petrographic and whole-rock geochemical data and U-Pb ages combined with Hf isotope data of detrital zircons from the volcanosedimentary Chilla beds exposed on the Altiplano southwest of La Paz, Bolivia. The presence of basalt to andesite lavas and tuffs of continental tholeiitic affinity provides evidence of a rift setting for the volcanics and, by implication, the associated sedimentary rocks. U-Pb ages of detrital zircons (n = 124) from immature, quartz-intermediate sandstones have a limited range between 1737 and 925 Ma. A youngest age cluster (n = 3) defines the maximum depositional age of 925 ± 12 Ma. This is considered to coincide with the age of deposition because Cryogenian and younger ages so typical of Phanerozoic units of this region are absent from the data. The zircon age distribution shows maxima between 1300 and 1200 Ma (37% of all ages), the time of the Rondônia–San Ignacio and early Sunsás (Grenville) orogenies in southwestern Amazonia. A provenance mixing model considering the Chilla beds, Paleozoic Andean units, and data from eastern Laurentia Grenville sources shows that >90% of the clastic input was likely derived from Amazonia. This is also borne out by multidimensional scaling (MDS) analysis of the data. We also applied MDS analysis to combinations of U-Pb age and Hf isotope data, namely εHf(t) and 176Hf/177Hf values, and demonstrate again a very close affinity of the Chilla beds detritus to Amazonian sources. We conclude that the Chilla beds represent the first and hitherto only evidence of Rodinia breakup in Tonian time in Andean South America