Studies on induction hardening of powder-metallurgy-processed Fe-Cr/Mo alloys

Induction hardening of dense Fe-Cr/Mo alloys processed via the powder-metallurgy route was studied. The Fe-3Cr-0.5Mo, Fe-1.5Cr-0.2Mo, and Fe-0.85Mo pre-alloyed powders were mixed with 0.4wt%, 0.6wt%, and 0.8wt% C and compacted at 500, 600, and 700 MPa, respectively. The compacts were sintered at 1473 K for 1 h and then cooled at 6 K/min. Ferrite with pearlite was mostly observed in the sintered alloys with 0.4wt% C, whereas a carbide network was also present in the alloys with 0.8wt% C. Graphite at prior particle boundaries led to deterioration of the mechanical properties of alloys with 0.8wt% C, whereas no significant induction hardening was achieved in alloys with 0.4wt% C. Among the investigated samples, alloys with 0.6wt% C exhibited the highest strength and ductility and were found to be suitable for induction hardening. The hardening was carried out at a frequency of 2.0 kHz for 2-3 s. A case depth of 2.5 mm was achieved while maintaining the bulk (interior) hardness of approximately HV 230. A martensitic structure was observed on the outer periphery of the samples. The hardness varied from HV 600 to HV 375 from the sample surface to the interior of the case hardened region. The best combination of properties and hardening depth was achieved in case of the Fe-1.5Cr-0.2Mo alloy with 0.6wt% C.     

Lettuce seedling growth: Antagonism between gibberellic acid and Niacin

Zusammenfassung Gibberellin und Niacin sind Antagonisten, Niacin hemmt das Wurzelwachstum vonLactuca sativa, während Gibberellin diese Wirkung teilweise aufhob.     

The distribution of nutrients in the seed parts of bengal gram

Zusammenfassung Die bengalische «Gram»-Pflanze (Cicer arietinum L.) ist in Samenschale, Cotyledonen und Restteile des Embryos zerlegt worden. In diesen Fragmenten wurde die Verteilung von Protein, Extraktstoffen, Asche, Faseranteilen sowie Calzium, Phosphor und Eisen näher untersucht. In den relativ massiven Samenschalen fand sich auffallend viel Calcium, während die übrigen untersuchten Stoffe in den andern Pflanzenteilen (mit Ausnahme vom Faseranteil) nur geringfügig vorhanden waren. Die Cotyledonen, die mehr als 85% dieses Getreides ausmachen, zeigen chemisch ausgeglichene Verhältnisse.     

Magnetic and flotation studies of banded hematite quartzite (BHQ) ore for the production of pellet grade concentrate

To identify and establish beneficiation techniques for banded hematite quartzite (BHQ) iron ore, a comprehensive research on BHQ ore treatment was carried out. The BHQ ore was assayed as 38.9wt% Fe, 42.5wt% SiO₂, and 1.0wt% Al₂O₃. In this ore, hematite and quartz are present as the major mineral phases where goethite, martite, and magnetite are present in small amounts. The liberation of hematite particles can be enhanced to about 82% by reducing the particle size to below 63 μm. The rejection of silica particles can be obtained by magnetic and flotation separation techniques. Overall, the BHQ ore can be enriched to 65.3wt% Fe at 61.9% iron recovery. A flowsheet has been suggested for the commercial exploitation of the BHQ ore.     

Do IMF fiscal forecasts add value?

We used a panel of 29 advanced and emerging market countries to investigate whether the IMF's World Economic Outlook (WEO) fiscal forecasts add value in terms of forecast accuracy and information content, relative to private sector forecasts (from Consensus Economics). We find that: (i) WEO forecasts are not significantly less accurate than Consensus forecasts; (ii) WEO and Consensus forecasts tend to mutually encompass one another; and (iii) each source of forecasts appears to contain some information that is not embedded in the other source.     

Yeast RAD14 and human xeroderma pigmentosum group A DNA-repair genes encode homologous proteins.

Xeroderma pigmentosum (XP), a human autosomal recessive disorder, is characterized by extreme sensitivity to sunlight and high incidence of skin cancers. XP cells are defective in the incision step of excision repair of DNA damaged by ultraviolet light. Cell fusion studies have defined seven XP complementation groups, XP-A to XP-G. Similar genetic complexity of excision repair is observed in the yeast Saccharomyces cerevisiae. Mutations in any one of five yeast genes, RAD1, RAD2, RAD3, RAD4, and RAD10, cause a total defect in incision and an extreme sensitivity to ultraviolet light. Here we report the characterization of the yeast RAD14 gene. The available rad14 point mutant is only moderately ultraviolet-sensitive, and it performs a substantial amount of incision of damaged DNA. Our studies with the rad14 deletion (delta) mutation indicate an absolute requirement of RAD14 in incision. RAD14 encodes a highly hydrophilic protein of 247 amino acids containing zinc-finger motifs, and it is similar to the protein encoded by the human XPAC gene that complements XP group A cell lines.     

Carotenogenesis: Possible mechanism of action of trisporic acid in Blakeslea trispora

Summary Stimulatory effect of trisporic acid and -ionone on carotenogenesis seems to be of a competitive nature in the minus strain of Blakeslea trispora, which suggests the same site of action. Trisporic acid may be derepressing the enzyme(s) involved in the conversion of 5-phosphomevalonate to dimethyl allyl pyrophosphate.Acknowledgment. The investigation was supported by a PL-480/FG-IN-509 grant from the Agricultural Research Service of the United States Department of Agriculture.     

Carbon Nanotube-Conducting Polymer Composites Based Solar Cells

1 Results Combination of carbon nanotubes (CN) with polymers is important for application towards value added composites,solar cells,fuel cells etc.Especially interesting is the combination of CN with π-conjugated polymers because of the potential interaction between the highly delocalized π-electrons of the CN and the π-electrons correlated with the lattice of polymer skeleton.Efficient exciton dissociation due to electron transfer from the photoexcited polymer to CN is of interest for photovoltaic app...