RESUMO: As condições físicas do solo são diretamente relacionadas com as práticas de manejo e o formato do relevo. A falta de manejo adequado pode levar os solos a processos erosivos e consequentemente degradação dessas áreas. Atualmente, estudos de variabilidade espacial permitem obter uma melhor análise para tomada de decisões e resoluções das referidas problemáticas. Pensando nisso, o presente estudo teve como objetivo avaliar a variabilidade espacial da infiltração de água no solo, densidade do solo e textura em área de encosta sobre processo de degradação. A pesquisa foi realizada em área de encosta com cultivo de pastagem, localizada entre os municípios de Areia (PB) e Remígio (PB). O solo foi amostrado em grade com malha regular (20 x 20m) entre pontos amostrais, perfazendo um total de 49 pontos em duas profundidades (0-10 cm; 10-20 cm), totalizando 98 amostras. Para a análise da variabilidade espacial foi utilizado a geoestatística, por meio da análise semivariográfica, interpolação dos dados por krigagem e construção de mapas de isolinhas. Todos os atributos físicos analisados apresentaram dependência espacial, uma vez que nenhum deles mostrou efeito pepita puro. Pôde-se verificar através dos mapas que houve uma relação muito clara entre a infiltração e os demais atributos físicos do solo, observando essa correlação principalmente na parte superior sudoeste da encosta.

In the state of Paraíba, one of the activities of great economic importance is that of the kaolin processing industry. This type of processing generates large amounts of waste that are displayed randomly in the environment, which has attracted attention, because the environmental impact caused by it and the lack of established process of recycling. The University Federal o Paraíba has been developing several research to explore the potential for recycling of industrial waste from Paraíba, mainly waste of kaolin. This research have pointed to the feasibility of using waste as aggregate and pozzolan in the development of mortars use multiple. These wastes have different size fractions, depending on the stage of processing: a sandy (termed in this study of RGC) containing mainly quartz, mica and calcite; and other clay (termed in this study of RFC) is thinner, containing higher amounts of kaolinite. This study aims to evaluate the potential of alkaline activation from waste kaolin (RGC and RFC) by comparing the activation using sodium silicate and hidroxide of calcium. With the objective of studying the potential of waste as a material pozzolanic, it was processing through grinding at 80.000, 60.000, 40.000, 20.000 and 10.000 rotations and with the purpose of evaluating the reactivity of materials, these wastes were calcined at 750°C/2h. For the mechanical characterization was using an equipment universal testing of Shimadzu Servopulser, where it was observed that only RFC, when calcined, developed strength in both activations, and the activated with silicate sodium with higher strength. The RGC, both in the state in natura and calcined did not show satisfactory mechanical strength to the test under the conditions of synthesis used in this research. Thus, the waste RFC's studied in this work has the potential to be used as constituent materials for building blocks in terms of its mechanical properties.

Avaliação da eficiência do uso da fita métrica para estimativa do peso corporal em bovinos Curraleiro Pé-Duro Efficiency evaluation of the metric tape use to estimate the body weight in Curraleiro Pé-Duro cattle

This study aimed to evaluate the gas exchanges in genotypes of Nopalea cochenillifera Salm-Dyck in different seasons and times of the day. The experiment was conducted with the varieties Miúda and Baiana at the Experimental Station Prof. Ignacio Salcedo, belonging to the National Semi-Arid Institute (INSA), in the municipality of Campina Grande, State of Paraíba, Brazil. The treatments were distributed in a 24 × 2 factorial arrangement, corresponding to gas exchange evaluations performed every hour for 24 hours in the rainy season (June) and in the drought season (December). Analyzed were stomatal conductance, transpiration rate, CO2 uptake, and internal CO2 concentration, besides instantaneous water-use efficiency, intrinsic water-use efficiency, and instantaneous carboxylation efficiency. In both drought and rainy seasons, variety Baiana presented higher gas exchange intensity than the variety Miúda. In the rainy season, gas exchanges are potentialized in both varieties evaluated. In this period, the peak of CO2 uptake occurs from 1:00 a.m. to 3:00 a.m. for the verity Baiana, and from11:00 p.m. to 2:00 a.m. for the variety Miúda, whereas, in the drought season, it occurs from 11:00 p.m. to 2:00 a.m. for both varieties, with these constituting the ideal intervals for measuring gas exchanges in the field.

The University Federal of Paraíba has developed various researches to explore the potential for recycling of industrial waste of Paraíba. Among them, the potential of use in the waste generated by processing of kaolin, which is one of the activities of great economic importance to the State of Paraíba and municipalities producers, because it causes a great environmental impact due to lack of an established recycling process. The kaolin processing generates large amounts of waste, one of fractions, a sandy (called in this study of RGC) containing quartz, mica and calcite; and other clay (called in this study of RFC) containing higher amounts of kaolinite. This objective of study is the characterization physical, chemical and mineralogical of waste kaolin (RFC and RGC) in order to evaluate the potential use of these wastes in the alkaline activation using silicates sodium and potassium. The characterizations physics, chemistry and mineralogy were by XRF, XRD, Unit Mass, Specific Mass and Specific Area. With the objective of studying the potential of waste as a material pozzolanic, it was processing through grinding at 10.000, 20.000, 40.000, 60.000 and 80.000 rpm and with the purpose of evaluating the reactivity of materials, these wastes were calcined at 750°C/2h.The wastes RFC and RGC had different properties according to the processing. Thus, the waste RFChas the potential pozzolanic to use in alkaline activation.