Structural optimization approach for specially shaped composite tank in spacecrafts

This study proposes an optimized approach of designing in which a model specially shaped composite tank for spacecrafts is built by applying finite element analysis. The composite layers are preliminarily designed by combining quasi-network design method with numerical simulation, which determines the ratio between the angle and the thickness of layers as the initial value of the optimized design. By adopting an adaptive simulated annealing algorithm, the angles and the numbers of layers at each angle are optimized to minimize the weight of structure. Based on this, the stacking sequence of composite layers is formulated according to the number of layers in the optimized structure by applying the enumeration method and combining the general design parameters. Numerical simulation is finally adopted to calculate the buckling limit of tanks in different designing methods. This study takes a composite tank with a cone-shaped cylinder body as example, in which ellipsoid head section and outer wall plate are selected as the object to validate this method. The result shows that the quasi-network design method can improve the design quality of composite material layer in tanks with complex preliminarily loading conditions. The adaptive simulated annealing algorithm can reduce the initial design weight by 30%, which effectively probes the global optimal solution and optimizes the weight of structure. It can be therefore proved that, this optimization method is capable of designing and optimizing specially shaped composite tanks with complex loading conditions.

Synthetic and physicochemical studies of uranium complexes with semicarbazone and hydrazone

Uranyl complexes of two Schiff bases, semicarbazone and hydrazone containing OON donor atoms have been synthesized and characterized on the basis of NMR, IR and electronic spectral studies, conductance, magnetic susceptibility and thermogravimetric data. The 1H NMR spectrum of the semicarbazone complex shows low field signals due to OH, NH and ---CH=N groups at 10.23, 9.31 and 8.17 ppm, respectively. The aromatic protons appear in the range 7.74–7.40 ppm. On complexation with U(VI) the signals due to OH and NH disappear evidently due to their participation in coordination. The coordination number of the o-vanillin semicarbazone (oVSC) complex is 6 whereas, that of the o-vanillin isonicotinic acid hydrazone (oVINAH) complex is 8, in addition to the two oxygen atoms already bonded to U(VI) in each species. The thermograms show the presence of 3 and 2 water molecules in these complexes, respectively and the IR spectral data also support the above conclusion. Suitable structures have been assigned.

The effect of spirulina (fresh and dry) on some biological factors in Penaeus semisulcatus larvae

Spirulina is a filamentous cyanobacteria with many applications in food and drug industries, as a food in human, aquaculture, vet and poultry industries… . Semi and mass culture of Spirulina carries out in different countries. This study was carried out in five phases in order to produce this microalga in Iran. The first phase, Spirulina pure stock was imported from Indonesia. After identification of species, it was cultured in laboratory until we took 20 liters of biomass. The semi-mass culture was carried out in green house. Cell concentration and size of Spirulina were recorded during culture daily and their growth rates were calculated. After two weeks, when the size of Spirulina was suitable, biomass of Spirulina was harvested then accumulated Spirulina weighted and dried in 24 hours in laboratory. In order to microbiological study, the samples of Spirulina (dry and fresh) were cultured on blood agar medium and coliforms were counted. The chemical composition of produced Spirulina was measured by standard methods. Fatty acid and amino acid profiles were acquired by GC and HPLC instruments, respectively. The amount of chlorophyll in Spirulina was determined by spectroscopy method. Also astaxanthin pigment as an important carotenoid was measured by HPLC in Spirulina and Penaeus semisulcatus larvae fed on Spirulina. At final phase of this project, larva fed on produced Spirulina (biomass and dry powder) was compared to Z plus, microencapsulated Spirulina (M.C.F) and Chaetoceros algae as control. This experiment was carried from zoa to early post larvae stage then survival and growth rate of larvae were recorded. The growth rate of larvae was evaluated with ANOVA test and survival rate of treatments was assessed by Log Rank (Mantel –Cox) test. Also during larvae stage, two parameters of water such as nitrate and nitrite were measured in zoa, mysis and post larvae stages. The results of this study were shown that colifom counts were 1.85×106 and 92.3×105 coliform per ml in fresh and dry spirulina, respectively. Protein percent of dry spirulina was 50.93 % (dry weight) and the amount of astaxanthin in spirulina and larvae fed on spirulina were 0.21 and 0.01 mg/kg, respectively. The most survival rate of larvae were observed in zoa III (88.8%) with Z plus supplement treatment, in mysis III (76.5%) combination of Z plus and dry spirulina in comparative between treatments. Larvae growth (4.5mm) of control in early post larvae was the best.

Aula Activa de la Naturaleza. Espinosa de los Monteros (Burgos)

Estudio de la zona de Espinosa de los Monteros (Burgos) sobre los aspectos que configuran el medio humano y natural (relieve, suelos, clima, flora, fauna, pasado hist??rico, manifestaciones art??sticas, poblaci??n, recursos, usos del territorio, ecolog??a humana) con el objetivo de servir de gu??a did??ctica y documental para el desarrollo del programa de Aulas Activas de Educaci??n ambiental llevado a cabo por la Consejer??a de Educaci??n y Cultura de la Junta de Castilla y Le??n con alumnos de los Centros no Universitarios de esta Comunidad Aut??noma.