Embedded System for Real Color Composition in Experimental Physics

Software can be considered educational when properly contextualized in a relationship of teaching and learning. This paper describes an embedded system and an educational software developed and applied in experimental physics to real and virtual colors composition. The educational system developed allows student interaction by voice commands, which makes the assimilation process of red/green/blue (RGB) color formation concepts more didactic and playful. The application of educational software in experiments also allows to verify, in real time, the influence of programs change on the physical phenomena and stimulates the logical reasoning development and consequently the autonomy of the students, to the measure that can raise hypothesis, make modifications in the programming and take off conclusions from the practical results obtained

Compartimentos da matéria orgânica do solo sob sistemas de manejo em território Quilombola no Cerrado brasileiro

Objetivou-se, neste trabalho, avaliar os compartimentos da matéria orgânica do solo e o índice de manejo de carbono em áreas cultivadas de forma conservacionista e convencional por agricultores quilombolas, em Goiás. As áreas estudadas foram no Cerradão: Cerrado Nativo; Pastagem; Plantio Convencional de Grãos; Plantio Conservacionista de Cultura Perene; e no Cerrado sensu stricto: Cerrado Nativo; Pastagem Natural; Plantio Convencional de Grãos; Plantio Convencional de Cultura Perene. Amostras de solo foram coletadas totalizando cinco repetições em cada área. Foram determinados o carbono orgânico total, as frações das substâncias húmicas, o carbono lábil e o índice de manejo do carbono. A fitofisionomia cerradão apresentou os maiores valores de carbono orgânico total e das frações estáveis da matéria orgânica do solo. As áreas nativas apresentaram baixos teores de carbono lábil. O cultivo conservacionista foi o que apresentou os maiores acúmulos de carbono nos diferentes compartimentos da matéria orgânica e o maior índice de manejo de carbono.The aim of this study was to evaluate the stable and labile fractions of soil organic matter and carbon (C) management index in cultivated areas with conservation and conventional management used by Quilombola farmers in the Goiás state, Brazil. The management systems were studied in the areas of Cerradão: Native Cerrado; Pasture; Conventional grain cultivation; Conservation cultivation of perennial crop; and in the sensu stricto Cerrado: Native Cerrado; Natural pasture; Conventional grain cultivation; Conventional cultivation of perennial crop. The study was considered as observational, with five replicates. Total organic C, fractions of humic substances, labile C and C management index were determined. The Cerradão phytophysiognomy had the highest total organic C values and stable soil organic matter fractions. The native areas had low levels of labile C. The conservation cultivation of perennial crop showed the largest accumulation of total organic C in the different fractions of soil organic matter and the highest rates of C management index

Compartimentos da matéria orgânica do solo sob sistemas de manejo em território Quilombola no Cerrado brasileiro

Objetivou-se, neste trabalho, avaliar os compartimentos da matéria orgânica do solo e o índice de manejo de carbono em áreas cultivadas de forma conservacionista e convencional por agricultores quilombolas, em Goiás. As áreas estudadas foram no Cerradão: Cerrado Nativo; Pastagem; Plantio Convencional de Grãos; Plantio Conservacionista de Cultura Perene; e no Cerrado sensu stricto: Cerrado Nativo; Pastagem Natural; Plantio Convencional de Grãos; Plantio Convencional de Cultura Perene. Amostras de solo foram coletadas totalizando cinco repetições em cada área. Foram determinados o carbono orgânico total, as frações das substâncias húmicas, o carbono lábil e o índice de manejo do carbono. A fitofisionomia cerradão apresentou os maiores valores de carbono orgânico total e das frações estáveis da matéria orgânica do solo. As áreas nativas apresentaram baixos teores de carbono lábil. O cultivo conservacionista foi o que apresentou os maiores acúmulos de carbono nos diferentes compartimentos da matéria orgânica e o maior índice de manejo de carbono.The aim of this study was to evaluate the stable and labile fractions of soil organic matter and carbon (C) management index in cultivated areas with conservation and conventional management used by Quilombola farmers in the Goiás state, Brazil. The management systems were studied in the areas of Cerradão: Native Cerrado; Pasture; Conventional grain cultivation; Conservation cultivation of perennial crop; and in the sensu stricto Cerrado: Native Cerrado; Natural pasture; Conventional grain cultivation; Conventional cultivation of perennial crop. The study was considered as observational, with five replicates. Total organic C, fractions of humic substances, labile C and C management index were determined. The Cerradão phytophysiognomy had the highest total organic C values and stable soil organic matter fractions. The native areas had low levels of labile C. The conservation cultivation of perennial crop showed the largest accumulation of total organic C in the different fractions of soil organic matter and the highest rates of C management index

Inhibitory action of Lippia gracilis Schauer essential oil on pathogenic bacteria and its effects as a growth promoter on quail

Aim of the study: To examine the in vitro sensitivity of Salmonella sp. and Escherichia coli strains to the microbial activity of Lippia gracilis Schauer essential oil (LGSEO) and to determine the optimal level of LGSEO as a growth promoter in diets for Japanese quail up to 35 days of age.Area of study: São Cristovão, Sergipe, Brazil.Material and methods: A total of 504 female Japanese quails (Coturnix coturnix japonica) at an initial average body weights of 6.80±0.10 g was allotted to one of six treatments (0, 100, 200, 300, 400 mg/kg of LGSEO and a diet containing 500 mg/kg of bacitracin methylene disalicylate) in 7 replicates, using 12 birds per experimental unit.Main results: In the age period of 21 to 35 days, feed intake declined linearly (p=0.04) and feed efficiency improved (p<0.01), whereas no changes were observed in production performance (p>0.05). The estimated (p=0.01) maximum relative weights of proventriculus and pancreas were obtained at the LGSEO inclusion levels of 196.5 and 251 mg/kg, respectively. Inclusion of 100 to 300 mg/kg of LGSEO in the diet reduced the total Salmonella sp. bacterial count.Research highlights: The use of 196.5 mg/kg of LGSEO in the diet of Japanese quail improved production performance and organ development and demonstrated potential antimicrobial capacity against Salmonella sp. bacteria. Due its pharmacological composition, LGSEO can potentially substitute to antimicrobials, because contains thymol and carvacrol as main active constituents

Microwave-Driven Hexagonal-to-Monoclinic Transition in BiPO4: An In-Depth Experimental Investigation and First-Principles Study

Present theoretical and experimental work provides an in-depth understanding of the morphological, structural, electronic, and optical properties of hexagonal and monoclinic polymorphs of bismuth phosphate (BiPO4). Herein, we demonstrate how microwave irradiation induces the transformation of a hexagonal phase to a monoclinic phase in a short period of time and, thus, the photocatalytic performance of BiPO4. To complement and rationalize the experimental results, first-principles calculations have been performed within the framework of density functional theory. This was aimed at obtaining the geometric, energetic, and structural parameters as well as vibrational frequencies; further, the electronic properties (band structure diagram and density of states) of the bulk and corresponding surfaces of both the hexagonal and monoclinic phases of BiPO4 were also acquired. A detailed characterization of the low vibrational modes of both the hexagonal and monoclinic polymorphs is key to explaining the irreversible phase transformation from hexagonal to monoclinic. On the basis of the calculated values of the surface energies, a map of the available morphologies of both phases was obtained by using Wulff construction and compared to the observed scanning electron microscopy images. The BiPO4 crystals obtained after 16–32 min of microwave irradiation provided excellent photodegradation of Rhodamine B under visible-light irradiation. This enhancement was found to be related to the surface energy and the types of clusters formed on the exposed surfaces of the morphology. These findings provide details of the hexagonal-to-monoclinic phase transition in BiPO4 during microwave irradiation; further, the results will assist in the design of electronic devices with higher efficiency and reliability

Valor nutritivo de pastagens de capim-elefante manejadas sob sistema convencional e agroecológico.

O capim-elefante é utilizado, na sua grande maioria, em sistemas convencionais de produção animal. O objetivo deste trabalho foi comparar o valor nutritivo do capimelefante em sistemas de manejo agroecológico e convencional, quanto a proteína bruta (PB), fibra em detergente neutro (FDN) e digestibilidade in vitro da matéria seca (DIVMS). Foram usados quatro piquetes, com 0,12ha cada um. No sistema convencional, o capim-elefante foi estabelecido singularmente. No sistema agroecológico, o plantio foi feito em linhas afastadas de 3m. Nas entrelinhas, estabeleceu-se a aveia e o azevém no período hibernal, enquanto que no período estival permitiu-se o desenvolvimento de espécies espontâneas. A adubação foi feita com fertilizantes orgânicos (150kg ha-1 de N). No sistema agroecológico, foram conduzidos sete pastejos, de 24/04/2004 a 05/05/2005. Na pastagem convencional, usouse a mesma quantidade de N (uréia), sendo conduzidos quatro ciclos de pastejo, de 06/10/2004 a 05/05/2005. Para ambos os sistemas foram utilizadas vacas da raça Holandês, recebendo complementação alimentar de 3,5kg dia-1 de concentrado com 20% de proteína bruta, constituindo-se nos animais experimentais. Nas avaliações, considerou-se a massa de forragem inicial com base na matéria seca (MS), os componentes botânicos da pastagem e estruturais do capimelefante. As análises de qualidade foram feitas em amostras de pastejo simulado. O delineamento experimental foi o inteiramente casualizado com dois tratamentos, convencional e agroecológico, duas repetições (piquetes) e em parcelas incompletas subdivididas no tempo (pastejos). Houve interação (P<0,05) entre tratamentos e pastejos em todas as variáveis. Na pastagem agroecológica, o modelo que melhor se ajustou foi o cúbico para todas as variáveis, em função do tempo de pastejo. Na pastagem convencional, a PB e a DIVMS ajustaram-se melhor ao modelo linear, com taxa positiva de crescimento, sendo observado comportamento inverso para FDN, com o decorrer dos pastejos. Tanto na pastagem convencional quanto na agroecológica encontraram-se associações negativas entre lâmina foliar do capim-elefante com PB e DIVMS e positiva com FDN. Ambos os sistemas apresentaram teores qualitativos elevados das pastagens, considerando-se a adubação, o manejo e o tempo de utilização