Wälzkontaktermüdung bei Mischreibung

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2009

Lattice point inequalities and face numbers of polytopes in view of central symmetry

Magdeburg, Univ., Fak. für Mathematik, Diss., 2012

Estudos químico-agrícolas sôbre o enxofre

1. Analyses of soluble sulphates in 2 N ammonium chloride extracts of 24 samples of soils of the state of São Paulo, Brazil, S. A., showed a sulphur content varying from 0,0013 g per 100 g (found in the b layer of a genuine "terra roxa") to 0,007 g per 100 g of soil (b layer of a soil of depression without definite characteristics). (The results are expressed as elemental sulphur). Determinations of total sulphur in 56 samples of soils of the same state using the method of fusion with sodium carbonate and sodium nitrate revealed 0.007 g of elemental S per 100 g of soil as the lowest value (found in several soil types) and 0.096 g as the highest one (found in the b layer of an ar-quean soil). Apparently soluble sulphates accumulate in the upper layers and total sulphur does the opposite. It was found a strong correlation between total S and carbon content. 2. Under laboratory conditions, in a compost of fresh soil, powdered sulphur and apatite, it was verified after a three months period of incubation that the pH value lowered from 6.30 to 3.23; the citric acid solubility of apatite increased to 271.1 per cent of the original one. Lupinus sp. grown in soil manured with sulphur and apatite has showed fresh and dry weights higher than the plants in control pots; the results are significant at 5% level of probability; phosphorus content is also higher in the manured plants. It was observed a net influence of the apatite plus sulphur treatment on the weight of root nodosities that was four times greater than in the control plants. 3. Nearly five hundred determinations of S, N and P were carried out in 35 species of plants cultivated in the state of São Paulo. A great variation in the amounts of these elements was observed. As a general rule, the leaves contain more sulphur than the stems and roots show the lowest percentages. The conjunct roots and stem of guar (Cyamopsis psoraloides) revealed only 0.019 per cent sulphur; the leaves of kale showed the highest sulphur content, i. e., 2.114%. Apparently there is no correlation between the amounts of S, N and P. The ratio S/N increases from 0.006 (guar) to 0.485 (kale). The ratio S/P, always higher than the corresponding S/N, increases from 0.082 (guar) to 6.381 (older leaves of tomato plants). It is interesting to mention that several among the most important crops in the state of São Paulo namely, cotton, rice, coffee and sugar cane contain more sulphur than phosphorus. 4. Tomato plants cultivated in nutrient solution lacking sulphur showed the following visual symptons of deficiency : chlorosis first in the younger leaves and afterwards in all the leaves; anthocyanin pigments in the petioles and stems; absence of fruits; primary roots stunted and secondary ones longer than in the control plants; stems slender, hard, woody. The histological study of petioles suffering from sulphur deficiency revealed anthocyanin in the parenchyme layer instead of clo-rophyll pigments observed in normal petioles; in the chlorotic leaves the large chloroplasts present only the stroma but the small ones have a little amount of green pigments. Chemical analysis revealed in the abnormal plants : less sulphur and an increased proportion of phosphorus; older leaves contain more sulphur and less phosphorus than the younger ones probably due to physiological difficulties in translocation of sulphur bearing material; increased amount of total N attributed to accumulation of nitrates; marked decrease in ash, sugars and starch; increased proportion of crude fiber and dry material. In the plants suffering from sulphur deficiency photosyntetic rate decreased 34 per cent. 5. Tomato plants were succesfully cultivated in nutrient solution in absence of mineral sulphur but in presence of cysteine. The plants absorbed sulphur, under that form and were able to grow up quite well; the fruiting was normal. In this way rested cleary demonstrated the possibility of absorption of organic sulphur without previous mineralization and its utilization in the building up of protein molecules.

Wissensbasierte Softwareumgebung im Konstruktionsprozess

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2014

Effects of foliar fertilization of common bean (Phaseolus vulgaris, L.) during the seed-filling stage

An experiment was carried out with common bean (Phaseolus vulgaris, L.) in a Red Yellow Latossol, sandy phase, in order to study the influence of foliar spraying of the Hanway nutrient solution (NPKS) at grain filling stage on: 1) grain yield; 2) the uptake of fertilizer and soil nitrogen by this crop through the root system and 3) the efficiency of utilization of the nitrogen in the foliar spray solution by the grain. The results of this experiment showed that the foliar application of the Hanway solution with ammonium nitrate at the pod filling period caused severe leaf burn and grain yield was inferior to that of the plants which received a soil application of this fertilizer at the same stage. These facts can be attributed to the presence of ammonium nitrate in the concentration used. The composition of final spray was: 114,28 Kg NH4NO3 + 43,11 Kg potassium poliphosphate + 12,44 Kg potassium sulphate per 500 litres. The uptake of nitrogen fertilizer through the root system and the efficiency of its utilization was greater than that through the leaves.

Spatio-temporal pattern formation in microemulsions under different physical and chemical conditions

Otto-von-Guericke-Universität Magdeburg, Fakultät für Naturwissenschaften, Dissertation, 2016

Problemas nematológicos em bananeiras (Musa spp.) no Brasil

Em levantamento nematológico realizado durante quatro anos (1977-1981), envolvendo 157 amostras de raízes e solo da rizosfera de bananeiras (Musa spp.) coletadas em diversos estados brasileiros, obtiveram-se as seguintes porcentagens, de amostras positivas e densidades populacionais em 10g de raízes, respectiva mente para as espécies de nematóides identificadas: Helicotylenchus dihystera (23,5%-272), Heliootylenchus multicinctus (80,2%-1770), Macroposthonia ornata (1,2%-122), Meloidogyne spp.(55,4%--725), Radopholus sinilis (43,3%-1326), Rotylenchulus reniformis (7,6%-225) e Tylenchus sp. (0,6%-114). H. multicinatus foi a espécie mais abundante e distribuída. R. similis foi encontrado somente em áreas cultivadas com bananeiras Cavendish, com elevadas populações associadas a marcantes sintomas de presença do parasito. Meloidogyne spp. e //. dihyslera foram espécies amplamente distribuídas e possivelmente causem danos econômicos. A ocorrência ainda restrita de R. similis sugere a adoção de enérgicas medidas de controle visando a impedir a sua disseminação no País e a proteção de outros cultivos eventuais hospedeiros.

Entomological news.

v. 114 2002

Crescimento e deficiência de macronutrientes, boro e zinco em plantas de guar

Plantas de guar (Cyamopsis tetragonoloba L. (Taub.)) cv. Brooks foram cultivadas em quartzo e irrigadas com solução nutritiva completa e com omissão de micronutrientes, boro e zinco. Foi obtido o quadro sintomatológico das carências e avaliado o efeito da omissão sobre a produção de matéria seca das plantas. Os autores concluíram que: - A omissão de qualquer um dos elementos reduz o peso da matéria seca das plantas; - Obtiveram a sintomatologia de todos os nutrientes estudados; - A deficiência em enxofre manifesta-se inicialmente nas folhas mais velhas; - Os níveis analíticos obtidos para plantas normais e com sintomas de deficiência foram: N% 1,83-1,62; P% 0,20-0,04; K% 3,85-1,64; Ca% 2,34-0,56; Mg% 0,74-0,22; S% 0,39-0,03; B ppm 114-71; Zn ppm 17-6.

Ocorrência de aflatoxinas em farelo de algodão (Gossypium hirsutum L.) na safra de 1986

A ocorrência e o nível de contaminação, com aflatoxinas, foram determinadas em 169 amostras de farelo de algodão. As amostras foram fornecidas por indústrias de óleo localizadas nas regiões de Araraquara, Campinas, Bauru, Paraguaçu Paulista, Guararapes, Londrina e Maringá, coletadas nos meses de abril a novembro da safra de 1986. A determinação das aflatoxinas foi feita por cromatografia em camada delgada. Dos resultados pôde-se concluir que: 1) 114 amostras estavam contaminadas com aflatoxina, representando 67,4 5% do total; 2) o nível de contaminação foi baixo, com valores variando de menos de 10 até 40 ¼g/kg (ppb) , sendo que as amostras com 4 0 ppb representaram apenas 12,3 0% do total contaminado; 3) houve diferença significativa (alfa = 0,05) entre as regiões estudadas, tendo a de Maringá apresentado a maior incidência e os teores mais elevados de aflatoxina B1; 4) as regiões de menor incidência e menor teor de aflatoxina B1 foram Araraquara, Campinas e Bauru; 5) não houve predominância da incidência de aflatoxina B1 em qualquer época de toda a safra; 6) em todas as amostras investigadas, a única aflatoxina encontrada foi a B1.

Análise comparativa da estrutura populacional do ermitão endêmico do Atlântico Ocidental Loxopagurus loxochelis (Decapoda, Anomura) em duas regiões do estado de São Paulo, Brasil

A estrutura populacional do ermitão Loxopagurus loxochelis (Moreira, 1901) foi analisada por meio da distribuição de freqüência dos animais em classes de tamanho e da razão sexual. Espécimes foram coletados mensalmente no período de um ano (julho de 2002 a junho de 2003), em sete transectos (5 aos 35 m de profundidade), usando barco equipado com duas redes do tipo double-rig, nas enseadas de Caraguatatuba e de Ubatuba (Estado de São Paulo, Brasil). Em Caraguatatuba foram coletados 366 animais, sendo 222 machos (60,65%), 114 fêmeas não-ovígeras (31,15%) e 30 fêmeas ovígeras (8,20%) e, em Ubatuba, 126 ermitões, dos quais 81 machos (64,28%), 38 fêmeas não-ovígeras (30,16%) e sete fêmeas ovígeras (5,56%). Em Caraguatatuba, a alta incidência de fêmeas ovígeras ocorreu durante o inverno (julho de 2002), enquanto em Ubatuba, o número foi incipiente. O comprimento do escudo cefalotorácico variou de 2,0 a 7,9mm (5,29 ± 0,96mm) em Caraguatatuba, e em Ubatuba, de 2,7 a 7,5 mm (5,32 ± 0,95mm). A média de tamanho dos machos foi significativamente maior do que das fêmeas em ambas as áreas. A razão sexual total foi favorável aos machos (1,54:1 em Caraguatatuba e 1,9:1 em Ubatuba). Houve maior freqüência de machos nas últimas classes de tamanho, acompanhando os padrões observados em decápodes e evidenciando a existência de dimorfismo sexual em L. loxochelis. A distribuição de freqüência total foi unimodal para ambos os sexos, nas duas áreas. A presença de um número maior de machos em relação a fêmeas pode ser indício de que existam diferentes taxas de crescimento e de mortalidade entre os sexos, além de distribuição espacial diferencial entre estes. Apesar das diferentes características geomorfológicas entre as regiões de Caraguatatuba e Ubatuba, foi observada uma dinâmica de desenvolvimento similar para ambas as populações.

Bird community in an Araucaria forest fragment in relation to changes in the surrounding landscape in Southern Brazil

The dynamics of the bird community in a small forest fragment was evaluated along seven years in relation to changes in the surrounding landscape. The study area is an Araucaria forest fragment in Southern Brazil (state of Paraná). The sampling period covered the years 1988 through 1994 and the mark-release-recapture method was utilized. The landscape analysis was based on Landsat TM images, and changes in exotic tree plantations, native forest, open areas (agriculture, pasture, bare soil, and abandoned field), and "capoeira"(native vegetation < 2 m) were quantified. The relationship between landscape changes and changes in abundance diversity of forest birds, open-area birds, forest-edge birds, and bamboo specialists was evaluated. Richness estimates were run for each year studied. The richness recorded in the study area comprised 96 species. The richness estimates were 114, 118 and 110 species for Chao 1, Jackknife 1 and Bootstrap, respectively. The bird community varied in species richness, abundance and diversity from year to year. As for species diversity, 1991, 1993 and 1994 were significantly different from the other years. Changes in the landscape contributed to the increase in abundance and richness for the groups of forest, open-area and bamboo-specialist species. An important factor discussed was the effect of the flowering of "taquara" (Poaceae), which contributed significantly to increasing richness of bamboo seed eaters, mainly in 1992 and 1993. In general, the results showed that landscape changes affected the dynamics and structure of the bird community of this forest fragment over time, and proved to have an important role in conservation of the avian community in areas of intensive forestry and agricultural activities.

Botanisches Zentralblatt; referierendes Organ für das Gesamtgebiet der Botanik.

jahrg. 31, bd. 114 (1910)

Occasional papers of the California Academy of Sciences.

no. 114 (1975)