Automated design and STEP-NC machining of impellers

This paper presents the four stage approach followed for automated design and STEP-NC based machining of impellers. In the first stage, the design calculations are performed to construct the 'Meridional representation' of the radial impeller. Then 3D curves are projected from the 'Meridional representation' and 3D model is generated using UG-NX software. In the second stage, the process planning activities including tooling & setup plan are completed. Here, ball end mill cutters with suitable diameter and length are selected and appropriate process parameters as suited to 5 axis milling are considered. In the third stage, the tool path data based on contour area milling is generated and verified in the UG NX software. Finally, in the fourth stage, the model with the complete data is imported to STEP-NC software and the AP-238 format is generated. In this article the design procedure adopted for construction of 'Meridional Section' of a radial turbine is discussed with the general methdology to automate the process planning and tool path generation. A test case of radial impeller is presented with the results obtained by adopting STEP-NC format

Structural Microstructural and Electrical Transport Studies of Ba(Fe0.25Eu0.25Nb0.5)O3

The complex multifunctional ceramic Ba(Fe0.25Eu0.25Nb0.5)O3 (BFEN) has been synthesized. The structural studies show two iso-structured phases related with BFN and BEN co-exists in the compound. The high dielectric constant and low dielectric loss of the compound below 575 K promises industrial applications. The activation energies obtained from the Arrhenius analysis of dc conductivity supports possible ferroelectric transition at elevated temperatures. Thus the desirable properties of two different compounds viz. multiferroic properties of BFN and high quality factor of BEN are successfully incorporated in a single compound. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3101

LIBS-Based Detection of Antioxidant Elements in Seeds of Emblica officinalis

The aim of the study was to determine the effect of the elements of the extract of seed from Emblica officinalis on antioxidant enzymes and osmotic fragility of erythrocytes membrane in normal as well as streptozotocin-induced severely diabetic albino Wister rats. The results revealed that the untreated diabetic rats exhibited increase in oxidative stress as indicated by significantly diminished activities of free radical scavenging enzymes such as catalase (CAT) and superoxide dismutase (SOD) by 37.5% (p

Utilisation of High Energy Propellant Waste in Manufacturing of Fired Clay Bricks to Enhance the Acoustic Properties

The disposal and waste management of solid high energy propellant (HEP) is a considerate conservational problem. HEP waste is currently disposed in open or confined burning which may cause environmental hazards. In this paper, we examined and discussed results on recycling of HEP waste into fired clay bricks baked in different orientation. HEP modified bricks with 1.5%, 3% and 5 wt. % HEP waste content were manufactured and tested, and then compared against virgin clay bricks without HEP content. The effect of directional orientation of bricks baked with varying HEP content on acoustic properties were experimented and discussed. The sound transmission loss decreases with increase in HEP waste due to formation of independently closed directional pores. The transmission loss of horizontally baked during firing of bricks is nearly 5dB lower than vertically baked bricks. Results of the experimental studies indicate that HEP waste can be utilised in fired clay bricks and different orientation baking further enhances the acoustic properties

Structural, optical, and dielectric properties of A[(Mg0.32Co0.02) Nb0.66]O3 semiconductor, where (A = Ba, Sr or Ca)

Structural optical and dielectric properties of single phase A[(Mg0.32Co0.02) Nb0.66]O3, where A = Ba, Sr, or Ca, compounds were studied in the temperature range from room temperature (293 K) to 458 K. The X-ray diffraction revealed that the Ba[(Mg0.32Co0.02)Nb0.66]O3 [BMCN] compounds exhibit hexagonal symmetry whereas Sr[(Mg0.32Co0.02)Nb0.66]O3 [SMCN] and Ca[(Mg0.32Co0.02)Nb0.66]O3 [CMCN] compounds exhibit monoclinic symmetry. The replacement of Barium (r = 1.61 Å) by smaller ions like Strontium (r = 1.44 Å) or Calcium (r = 1.34 Å) in the polar dielectric Ba[(Mg0.32Co0.02) Nb0.66]O3 introduces the relaxation phenomenon and a gradual increase in the transition temperature maximum (Tm). The ac conductivity, as determined from the dielectric data, as a function of temperature and frequency, reveals the crossover from small polaron tunneling (SPT) to correlated barrier hopping (CBH) type conduction at » 370 K. The activation energy of the non-Debye type process evaluated both from the electric modulus and the conductivity data are nearly identical suggesting similarity in the hopping mechanism. The band gap of these materials lies in the range of narrow to wide band semi conductors. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2206

Effect of Rapid Thermal Annealing of CIGS Thin Film as an Absorber Layer

The influence of rapid post-deposition thermal annealing (500 °C for 2 minutes) on the CIGS thin films of different thicknesses (0.4 to 1.0 m) has been investigated. The deposition of CIGS is carried out using the flash evaporation at the substrate temperature of 250 °C. The as-grown and annealed CIGS is characterized by XRD, SEM, EDS, TEM, optical transmission, reflection, and electrical measurements. Lowering the thickness of CIGS absorber shows the remarkable influence on crystal structure, surface morphology, and composition of the overall film. Further improvement was observed by the rapid annealing process. Cu-rich composition was observed for annealed CIGS thin film having a thickness below 0.6 μm, while for 1.0 m thickness the composition is slightly Cu-poor and the compactly packed faceted grains observed. Optical band gap near to 1.05 eV and the electrical resistivity in the order of 104 Ωcm shows its future use as an absorber layer for CIGS solar cell. Furthermore, an attempt of making CIGS / CdS hetero-structure shows ideal behavior of the Schottky hetero-structure with the ideality factor of 1.5. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3100

Study on High Energy Propellant Waste in the Processing of Fired Clay Bricks

Utilisation of propellant waste in fabrication of bricks is not only used as efficient waste disposal method but also to get better functional properties. In the present study, high energy propellant (HEP) waste additive mixed with soil and fly ash in different proportions during manufacturing of bricks has been investigated experimentally. X-ray diffraction (XRD) studies were carried out to confirm the brick formation and the effect of HEP waste. Ceramic bricks were fabricated with HEP waste additive in proper proportions i.e. 0.5 wt %, 1.0 wt %, 1.5 wt %, 2.0 wt %, 2.5 wt %, 3 wt %, 3.5 wt %, and 4 wt % and then evaluated for water absorption capability and compressive strength. Compressive strength of 6.7 N/mm2, and Water absorption of 22 % have been observed from modified fired bricks impregnated with HEM waste additive. Scanning electron microscopy (SEM) studies were carried out to analyze the effect of HEP waste additive on pore formation and distribution in the bricks. Further, the heat resulting from decomposition of propellants can cause a decrease in the energy required of baking process. The process of manufacturing of bricks with HEP waste additive is first of its kind till date

Irradiation Effects on Microstructure and Dielectric Properties of Ba[(Mg0.32Co0.02)Nb0.66]O3 [BMCN] Thin Films

Ba[(Mg0.32Co0.02)Nb0.66]O3 [BMCN] thin films prepared on Pt-Si, MgO, Silicon and ITO coated glass substrates by Pulsed Laser Deposition Technique are investigated. Relative growth parameters suggest that ITO coated glass substrate has good potential for growing films with near Nano size columnar grains. In comparison to bulk, dielectric constant and dielectric loss increases in BMCN films. This undesirable rise in dielectric loss can be drastically reduced by a factor of more than 1/100th times through Ag15+ ion irradiation at 1 × 1012 ions/cm2 dose. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3025