The increasing world population is putting pressure on global food production. Agriculture must meet these growing demands by increasing crop yields. One phenomenon which prevents seedling emergence and damages crop yield is soil crusting. Understanding of soil crusting and the factors which influence it is fundamental to ensuring good crop production. An instrument which will test soil crust strength in a novel way, mimicking seedling growth, may lead to pre-emptive agricultural soil management which could increase crop production. This work details the process of design, construction and testing of an ascending penetrometer to measure soil crust strength. The full design process is discussed from concept generation and evaluation, using experimental methods and a multi-criteria decision making tool, through to final design configuration, specification, manufacture and testing. Traditionally, soil penetrometers measure soil strength by forcing a probe from the surface of the soil into the bulk soil below. To more accurately measure the direct impedance a seedling would experience a device should measure impedance from the bulk soil upwards and into the soil crust, mimicking what a growing seedling would experience. Results prove that the manufactured ascending penetrometer with a force resolution of 0.01N and displacement resolution of 0.0004mm is capable of detecting differences in soil crusts. At these resolutions and accuracy to 0.1N and 0.1mm excellent repeatability was achieved. The machine is therefore a useful and realistic tool for quantitatively comparing soil crusts in soil. It is hoped that being able to compare soil crust strength will lead to improved soil management techniques.

External sulphate attack on concrete can lead to cracking, expansion and sometimes loss of cohesiveness of hardened cement paste. Therefore, aside from using sulphate resistant cementitious binders, it is important to design concrete which can resist sulphate penetration. In this research, both ASTM C1202 and NT Build 492 electrical migration tests were modified such that sulphate rather than chloride penetration resistances were measured. Modifications included exposing concrete specimens to Na2SO4 rather than NaCl solutions and measuring the depth of sulphate penetration visually using BaCl2+KMnO4 rather than AgNO3 solution. Nine concrete mixtures of varying w/cm, slag replacement and cement types were tested in both original standard tests and modified tests to evaluate the influence of these material variables on test results and compare chloride to sulphate results. It was found that while migration coefficients and total charge passing were lower for sulphate, the influence of material variables were relatively similar.

External sulphate attack on concrete can lead to cracking, expansion and sometimes loss of cohesiveness of hardened cement paste. Therefore, aside from using sulphate resistant cementitious binders, it is important to design concrete which can resist sulphate penetration. In this research, both ASTM C1202 and NT Build 492 electrical migration tests were modified such that sulphate rather than chloride penetration resistances were measured. Modifications included exposing concrete specimens to Na2SO4 rather than NaCl solutions and measuring the depth of sulphate penetration visually using BaCl2+KMnO4 rather than AgNO3 solution. Nine concrete mixtures of varying w/cm, slag replacement and cement types were tested in both original standard tests and modified tests to evaluate the influence of these material variables on test results and compare chloride to sulphate results. It was found that while migration coefficients and total charge passing were lower for sulphate, the influence of material variables were relatively similar.

M. Tech. Engineering: Civil. / Discusses the objective of this study was to develop an equation to determine the penetrometer penetration rate (DN) of a pavement consisting of Bitumen Stabilised Material layers are constructed. The aim is to use laboratory results of Bitumen Stabilised Material and study the relations between the Indirect Tensile Strength and the Unconfined Compressive Strength. With the relations a penetrometer penetration rate (DN value in millimetre per blow) can be determined. This will enable the designer to apply the strength-balance concept on a pavement consisting of Bitumen Stabilised Materials. As indicated previously it was found during the design stages that only the Indirect Tensile Strength data on the Bitumen Stabilised Material was available. Developing an equation to convert the Indirect Tensile Strength data to a DN value will allow the designer to apply the strength-balance concept and adjust the design for improved performance life of a pavement.

Studies were conducted to determine if corn stalk strength had an effect on southwestern corn borer (Diatraea grandiosella Dyar) survival during different growth stages. In 2006 southwestern corn borer larvae were placed on corn during the tassel stage near the ear and base of the plant. Survival was higher near the ear than near the base of the plant. In 2007, five varieties of corn were planted at three locations in Mississippi. Plants were infested with five 3rd instar larvae at the ear zone during tassel, dough and dent development stages. After five days stalk strength and borer survival were measured. Survival decreased as the corn progressed from tassel to dent stage. Survival varied among corn varieties. The relationship between stalk strength and borer survival was not consistent, indicating that there are likely factors more directly limiting borer survival than physical stalk strength.

There are numerous examples in the literature of time-dependent changes in the proper-ties of sands, or aging effects. Most of these aging effects are of increases in the cone penetration resistance. Time-dependent increases in penetration resistance have been measured in hydraulically placed fills and freshly densified deposits, with the largest in-creases following the use of ground modification techniques such as vibrocompaction, dynamic compaction, and blast densification. It is not known what causes these increases in penetration resistance to occur. The objective of this research was to gain an understanding of the possible mechanisms responsible for aging effects in sands. Current hypotheses to explain what causes aging effects in sands include increased interlocking of particles, internal stress arching, and precipitation of silica or carbonate minerals at the contacts between grains. To date, no unambiguous evidence has been presented to support these hypotheses. A laboratory testing program was developed to study the influence of different variables on the pres-ence and magnitude of aging effects. Three different sands were tested in rigid wall cells and buckets. Samples were aged under different effective stresses, densities, tempera-tures, and pore fluids. In every rigid wall cell, three independent measurements were made to monitor property changes during the aging process: small strain shear modulus using bender elements, electrical conductivity, and mini-cone penetration resistance. At the end of each test, detailed mineralogical tests were performed to assess changes in the chemistry of the samples and pore fluids. A total of 22 tests in rigid wall cells were per-formed with periods of aging ranging from 30 to 118 days. Mini-cone penetration resis-tances were measured in the buckets before and at various times during the aging process. Increases in the small strain shear modulus were measured with time. It was found that sand type and pore fluid composition greatly influenced the amount of increase in small strain shear modulus. Density was also found to influence the amount of increase in small strain shear modulus. Temperature was found to have little influence on the in-crease in small strain shear modulus with time. Changes in the chemistry of the samples were also measured with time. The dissolution and precipitation of minerals in solution was monitored with electrical conductivity measurements. In most of the tests, there was continual dissolution of minerals with time. Mineralogical studies and conductivity measurements indicated precipitation of carbonates and silica in two of the tests; however, scanning electron micrographs showed no visible evidence of precipitation. Despite the measured increases in small strain shear modulus and evidence of mineral precipitation, there were no increases in the mini-cone penetration resistance with time. This finding is significant and suggests that small-scale laboratory experiments do not capture the mechanism(s) that are responsible for time-dependent increases in penetration resistance in the field. / Ph. D.

Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2019-03-01T16:32:39Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Marilaine Alves dos Santos.pdf: 2837056 bytes, checksum: d1d27f36680b82c616d26078c0272e32 (MD5) / Made available in DSpace on 2019-03-01T16:32:39Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Marilaine Alves dos Santos.pdf: 2837056 bytes, checksum: d1d27f36680b82c616d26078c0272e32 (MD5) Previous issue date: 2016-07-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A variabilidade nas condições físicas do solo ocorre devido uma série de fatores tanto climáticos, topográficos quanto em decorrência do uso e ocupação da terra. Esses fatores podem interferir no processo de infiltração de água no solo, gerando uma série de problemas, como a erosão do solo e as enchentes, muitas vezes advindos de um intenso escoamento superficial. Esta pesquisa teve como objetivo compreender a influência do uso e ocupação da terra na variabilidade sazonal da taxa de infiltração na bacia hidrográfica Rio Bonito em Irati, região Centro-sul do estado do Paraná. Mensurou-se a taxa de infiltração com um infiltrômetro de anel concêntrico, no período de junho de 2014 a julho de 2015, em quatro diferentes classes de uso: Cultura, Floresta, Pastagem e Áreas Urbanizadas. Foram realizadas também coletas de solos para análise de granulometria, densidade e porosidade, sendo abertas ao longo do perfil da vertente três trincheiras e coletados solos nas profundidades 0-5, 5-10, 1020, 20-30cm em cujos pontos foram realizadas coletas de umidade, compactação e infiltração. Foram constatados valores significativos de infiltração para as classes Cultura e Floresta e menores valores para Pastagem e Áreas Urbanizadas. A análise granulométrica revelou solos com altos teores de argila e silte. As maiores resistências a penetração foram encontradas na classe pastagem e a menor na floresta, a pastagem foi a classe que apresentou a maior densidade e a menor porosidade do solo, já a floresta a menor densidade e maior porosidade. A classe cultura embora tenha apresentado elevados valores de densidade e compactação registrou uma alta taxa de infiltração. A análise dos resultados de alguns atributos físicos do solo apresentou relação com a infiltração como resistência e densidade do solo, no entanto os valores mais significativos foram com a sazonalidade, que apresentou maiores valores de infiltração no inverno e na primavera. / The variability in the physical condition of the soil occurs because a series of climatic factors, as well as topographic due to use and occupancy of the land. These factors may interfere in the process of water infiltration into the soil, creating a series of problems such as soil erosion and flooding, often from a runoff. This research aimed to understand the influence of the use and occupation of land on seasonal variability of infiltration rate on watershed Rio Bonito in Irati, the Center-South region of the State of Paraná. Measure the rate of infiltration with a concentric ring infiltrômetro in the period of June 2014 to July 2015, in four different classes of use: Culture, forest, pasture and Urbanized Areas. Also soil samples were taken for analysis of particle size, density and porosity, being opened along the profile of three trenches and collected soil depths 0-5, 5-10, 10-20, 20-30 cm in whose collections were carried out points of moisture, compression and infiltration. Had been evidenced significant infiltration values for classes and Forest Culture and lower values for Pasture and Urbanized Areas. Particle size analysis revealed high levels of soil clay and silt. The greatest resistance to penetration was found in grassland and the lowest class in the forest, grazing was the class that presented the highest density and lowest porosity of the soil, the forest a lower density and higher porosity. The class culture although it has presented high values of density and compression registered a high rate of infiltration. The analysis of the results of some physical attributes of soil presented related to infiltration as resistance and soil density, however the most significant values were with seasonality, which presented higher values of infiltration in the winter and spring.

Submitted by DEISE CRISTINA SANTOS NOGUEIRA null (deise17nogueira@hotmail.com) on 2017-03-08T13:15:38Z No. of bitstreams: 1 Dissertação.pdf: 858288 bytes, checksum: 84d43bc8161733904a29be8fd6a0e023 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-03-13T13:13:26Z (GMT) No. of bitstreams: 1 nogueira_dcs_me_jabo.pdf: 858288 bytes, checksum: 84d43bc8161733904a29be8fd6a0e023 (MD5) / Made available in DSpace on 2017-03-13T13:13:26Z (GMT). No. of bitstreams: 1 nogueira_dcs_me_jabo.pdf: 858288 bytes, checksum: 84d43bc8161733904a29be8fd6a0e023 (MD5) Previous issue date: 2017-02-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Nos solos brasileiros, a caulinita, os óxidos de ferro e os hidróxidos de alumínio são alguns dos minerais encontrados na fração argila influenciando o comportamento dos atributos físicos do solo. O objetivo do presente trabalho foi avaliar a influência dos minerais da fração argila nos atributos físicos de um Argissolo Amarelo, submetido a dois tipos de preparo e cultivado com cana-de-açúcar. As amostras deformadas e indeformadas de solo foram coletadas após oito meses do plantio da cana-de-açúcar, em quatro camadas (0,00-0,10, 0,10-0,20, 0,20-0,40 e 0,40-0,60 m) na linha e entrelinha de plantio nas áreas submetidas à escarificação em área total e escarificação na linha da cultura. Através das amostras deformadas determinou-se a textura do solo, ferro extraído por ditionito-citrato-bicarbonato (FeDCB), ferro extraído por oxalato ácido de amônio (FeOAA) e razão caulinita/(caulinita+gibbsita) [(Ct/(Ct+Gb)]. Com as amostras indeformadas determinou-se a densidade do solo (Ds) e a resistência do solo à penetração (RP). Os resultados apresentados pela estatística descritiva demostraram que houve uma separação das áreas de estudo devido à diferença mineralógica encontrada nessas áreas, sendo a primeira área caracterizada pela maior razão Ct/(Ct+Gb) e a segunda área caracterizada pelos maiores teores de ferro extraído por ditionito-citrato-bicarbonato (FeDCB). Pela análise de componentes principais foi possível observar que o FeDCB apresentou correlação inversa com a Ds e a RP, a razão Ct/(Ct+Gb) apresentou correlação direta com os atributos físicos Ds e RP. A mineralogia influenciou o comportamento da densidade do solo e resistência do solo à penetração. A área com maior razão caulinita apresentou maiores valores de densidade do solo e de resistência do solo à penetração e a área com maiores teores de óxidos de ferro apresentou menores valores de densidade do solo e de resistência do solo á penetração. O preparo do solo não influenciou o comportamento da densidade do solo e da resistência do solo à penetração. / In Brazilian soils, kaolinite, iron oxides and aluminium hydroxides are some of the minerals found in the clay fraction influencing the behavior of the soil physical attributes. The objective of the present work was to evaluate the influence of minerals of the clay fraction on the physical attributes of a yellow Ultisol under two tillage and sugar cane cultivation. The disturbed and undisturbed samples of soil were collected in the row and interrow in the areas with chiselling in the total area and chiselling in the planting row in four layers (0,00-0,10, 010-0,20, 0,20-0,40, 0,40-0,60 m) eight months later the sugar cane cultivation. The soil texture, citrate/bicarbonate/dithionite extractable Fe, oxalate/acid/ammonium extractable Fe (FeOAA) and Ct / (Ct+ Gb) ratio were evaluated from disturbed samples and bulk density (Bd) and soil penetration resistance (SPR) were evaluated from undisturbed samples. The results presented by the descriptive statistics showed that there was a separation of the study areas due to the mineralogical difference found in these areas, being the first area characterized by the higher ratio Ct / (Ct + Gb) and the second area characterized by the higher citrate/bicarbonate/dithionite extractable Fe (FeDCB). In the principal component analysis, it was observed that the FeDCB showed an inverse correlation between Bd and SPR. It was also observed that the Ct / (Ct + Gb) ratio showed a direct correlation with the physical attributes Bd and SRP. The mineralogy influenced the behavior of the Bd and SPR. The area with higher Ct/ (Ct+Gb) ratio, showed higher values of Bd and SRP and The area with higher content of iron oxides had lower values of Bd and SRP. The soil tillage didn’t influence the behavior of Bd and SPR. / FAPESP: 2014/14490-2

Made available in DSpace on 2017-07-10T17:36:54Z (GMT). No. of bitstreams: 1 2014_Diss_Poliana_Ferreira_Costa.pdf: 1338360 bytes, checksum: 1c523ddb26369e2486b4cb15ce0647dc (MD5) Previous issue date: 2014-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The study was conducted to evaluate different management of winter cultures in a no-till system, assessing their influence on soil physical properties, dynamics of weeds, content and and nutrient accumulation on soybean in summer crop in Marechal Cândido Rondon - Paraná. The study was conducted in the experimental area of the State University of West Paraná - Campus Rondon in EUTRUSTOX (LVe). The experimental design was randomized blocks in band layout with three replications. The treatments consisted of four different winter crops (oats IPR 126, wheat BRS Tarumãt crambe FMS Bright and forage turnip cultivar common) and two management (chemical and mechanical). With respect to soil physical properties (macroporosity, microporosity, total porosity and density), it was found that only the macroporosity was altered due to interaction between the winter crops and systems of management that occurred in the 0 - 10 cm in the assessment after the harvest of soybean crop. As to the values obtained for the penetration resistance of the soil, it was found that the oat (0.91 MPa) and crambe (1.43 MPa) provided significant differences in the 0 - 5 cm depth. Sixteen weed species were identified in the area, distributed in eleven plant families, especially the families Poaceae and Asteraceae. The presence of weeds in chemical handlings was lower when compared to mechanical handling. In relation to nutrient content were no significant differences for the quantities of N, C and C / N ratio of the materials. As for the accumulation of nutrients wheat BRS showed higher for Mg absorption with 9,15 kg ha-1 / O estudo foi conduzido com o objetivo de avaliar diferentes manejos de culturas de inverno em um sistema de plantio direto, verificando a sua influência sobre as propriedades físicas do solo, dinâmica de plantas daninhas, teor e acúmulo de nutrientes e sobre a cultura da soja no cultivo de verão, em Marechal Cândido Rondon - Paraná. O trabalho foi desenvolvido em área experimental da Universidade Estadual do Oeste Paraná - Campus Marechal Cândido Rondon, em LATOSSOLO VERMELHO Eutrófico (LVe). O delineamento experimental utilizado foi o de blocos casualizados em esquema de faixas, com três repetições. Os tratamentos foram constituídos de quatro diferentes culturas de inverno (aveia IPR 126, crambe FMS Brilhante, Nabo forrageiro cultivar comum e trigo BRS Tarumã) e por dois manejos (químico e mecânico). Com relação às propriedades físicas do solo (macroporosidade, microporosidade, porosidade total e densidade), constatou-se que apenas a macroporosidade sofreu alterações, devido a interação entre as culturas de inverno e os sistemas de manejo empregados, ocorrido na camada de 0 10 cm na avaliação após a colheita da cultura da soja. Quanto aos valores obtidos para a resistência à penetração do solo, verificou-se que a aveia (0,91 Mpa) e o crambe (1,43 Mpa) ofereceram diferenças significativas, na camada de 0 5 cm de profundidade. Foram identificadas dezesseis espécies de plantas daninhas na área, distribuídas em onze famílias botânicas, destacando-se as famílias Poaceae e Asteraceae. A presença de plantas daninhas nos manejos químicos foi menor quando comparada ao manejo mecânico. Em relação aos teores de nutrientes houve diferenças significativas para as quantidades de N, C e relação C/N dos materiais. Já para o acúmulo de nutrientes o trigo BRS apresentou maior acúmulo para o Mg com 9,15 kg ha-1

Made available in DSpace on 2017-07-10T17:36:57Z (GMT). No. of bitstreams: 1 2014_Diss_Jeferson_Tiago_Piano.pdf: 1013753 bytes, checksum: d7a290e824e835fc82cc2e6dc888c48f (MD5) Previous issue date: 2014-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The study aimed and was conducted to evaluate the effects of different managements of cereals grown and subjected to grazing on soil physical properties, quantity and nutrient content of winter crop residues, besides the incidence of weeds. The study was conducted in the experimental area of the State University of West Paraná - Campus Marechal Cândido Rondon in Dystrophic Oxisol. The experimental design was randomized blocks in split-plot, with four replications. The treatments consisted of three different winter cereals (oats IPR 126, wheat and triticale BRS Tarumã IPR 111) in bands A and managements in B bands: ungrazed , one grazing and two grazing. With respect to soil physical properties (macroporosity, microporosity, total porosity and density), determined by collecting soil core, it was found that they suffered minor influences, with the exception of soil density due to treatments, evaluations after harvest of winter cereals and soybeans. The resistance to penetration, determined with an impact penetrometer, was influenced by the crop after harvest of winter cereals and by management after the soybean harvest in 20-25 cm layer and 25-30 cm depth. The different winter cereals used influenced the amount of remaining organic waste, the levels of C and P in the C:N. The largest amount of crop residues was found that the management was not performed grazing. Through the inventory square method, were identified 11 families and 16 species of weeds in the area, highlighting the Poaceae and Asteraceae families / O estudo foi conduzido com o objetivo de avaliar os efeitos de diferentes manejos de cereais de inverno cultivados e submetidos ao pastejo, sobre as propriedades físicas do solo, a quantidade e os teores de nutrientes dos resíduos culturais, além da incidência de plantas daninhas. O trabalho foi desenvolvido em área experimental da Universidade Estadual do Oeste Paraná - Campus Marechal Cândido Rondon, em LATOSSOLO VERMELHO Distroférrico (LVdf). O delineamento experimental utilizado foi o de blocos casualizados em esquema de faixas, com quatro repetições. Os tratamentos foram constituídos de três diferentes cereais de inverno (aveia IPR 126, trigo BRS Tarumã e triticale IPR 111) nas faixas A e os manejos nas faixas B: sem pastejo, um pastejo e dois pastejos. Com relação às propriedades físicas do solo (macroporosidade, microporosidade, porosidade total e densidade), determinadas com anéis volumétricos, constatou-se que estas sofreram pequenas influencias, com exceção da densidade do solo, devido aos tratamentos empregados, nas avaliações após a colheita dos cereais de inverno e da cultura da soja. A resistência do solo à penetração, determinada com penetrometro de impacto, foi influenciada pela cultura, após a colheita dos cereais de inverno e, pelo manejo após a colheita da soja, na camada de 20 a 25 cm e de 25 a 30 cm de profundidade. Os diferentes cereais de inverno utilizados influenciaram na quantidade de resíduos orgânicos remanescente, nos teores de C, P e na relação C:N. A maior quantidade de resíduos culturais foi encontrada no manejo em que não foi realizado pastejo. Através do método do quadrado inventário, foram identificadas 11 famílias e 16 espécies, de plantas daninhas na área, destacando-se as famílias Poaceae e Asteraceae