Role of powder metallurgical processing and TiB reinforcement on mechanical response of Ti-TiB composites

In this work, titanium–titanium boride (Ti–TiB) composites were synthesized by three different powder metallurgical techniques, namely, spark plasma sintering (SPS), hot iso-static pressing (HIP) and vacuum sintering (VS). The mechanical properties of the composites were determined using the nanoindentation technique. The role of the material processing route and TiB reinforcement employed on the mechanical properties of the composites was investigated. The results revealed that the composites processed by SPS possessed improved mechanical properties relative to those of the composites prepared by the HIP and VS techniques. Furthermore, reinforcement of the composites with TiB enhanced the hardness, elastic modulus and contact stiffness, whereas it reduced the fracture toughness and indentation creep

Fly Ash Particle Reinforced And Mechanical Properties Of AL6061 Graphite B4C Composites

Fly ash particle reinforced with aluminium alloy composite materials used for various industrial applications like automobile, aerospace, aircrafts, substrate in electronics, turbine blades, brake pads, golf clubs and it is also used in home products. Metal matrix composites (MMCs) are increased mechanical properties like strength, yield strength, hardness, impact strength and to improve fracture toughness when compared to unreinforced alloys. The main aim is to fabrication of Al6061/Fly ash, Boron carbide, Graphite, and also Magnesium metal matrix composite by using stir casting process and also study the mechanical properties of the fabricated composite material. Fly ashes with aluminium, composite materials are good mechanical and physical properties for very high temperature, resistant to wear and lowest weight applications. Aluminium composite preparing from liquid phase reaction present a unique microstructure. The each phase is a continuous network penetrated by the network of the other constituent. It is an increased composites containing lowest cost expensive and lowest density reinforcements. The fly is very less expensive and very low density reinforced in solid waste by the product during combustion of coal in thermal power plants. Hence, fly ashes with aluminium composites reinforcement are to overcome the cost expensive for wide applications in automotive ancillaries, aircrafts, turbine blades and also engine applications. In future we add the graphite, boron carbide and magnesium with Al6061 & Fly ash to produce other metal matrix composites.Keywords- Fly ash; Wear resistant; Metal–matrix composites (MMCs); Casting; Particle-reinforcement

Design and Analysis of Turbocharger Impeller in Diesel Engine

The main goal of this research is to be design the turbine and compressor impeller of a turbocharger for a diesel engine. It is to increase power and efficiency of a turbocharger. It is to usage of new material is required for an investigation. The existing work turbine and compressor impeller has been designed with different materials. The investigation has been done by using ANSYS and CATIA software. The turbine and compressor impeller modeling has been done by using CATIA software. The variation of stresses, strains and deformation profile of the turbine and compressor impeller has been determined by using ANSYS software. The identifying the accurate or exactdesign features, the extended service life and long term stability has been assured. A structural analysis is used to investigate the stresses, strains and displacements of the turbine and compressor impeller. A modal analysis is used to investigate the frequency and deflection of the turbine and compressor impeller. A thermal analysis is used to investigate the total heat flux and direction heat flux. The turbine and compressor impeller of a turbocharger will be recommend based on the better material results

Studies on diurnal variations in the occurrence of grey mullet seed at Mandapam

In order to study the diurnal variations in the occurrence of mullet seed, collections were made With a drag net once in a fortnight 3 to 6 days after the full moon and new moon days from august 1978 to July 1979 and also 2-3 days before full and new moon days from August 1979 to October 1979 in addition to the regular collections made on other days, at Theedai near Mandapam along the Palk bay

Preliminary experiments on the culture of grey mullets at Mandapam

The paper deals with experiments on the culture of grey mullets Valamugil seheli, Liza vaigiensis and Liza macrolepis in monoculture and polyculture systems in seawater ponds and a pen erected in coastal waters at Mandapam

Differential item functioning for items in Berger's HIV Stigma Scale: an analysis of cohorts from the Indian, Swedish, and US contexts

PURPOSE: To examine whether items in Berger's HIV Stigma Scale function differently with persons of different age, gender, and cultural backgrounds. METHODS: Secondary data from cohorts, collected in South India (n = 250), Sweden (n = 193), and the US (n = 603) were reanalyzed to evaluate DIF within, between, and across these cohorts. All participants had answered the revised version of the HIV stigma scale consisting of 32 items forming the subscales Personalized stigma, Disclosure concerns, Concerns about public attitudes, and Negative self-image. Differential Item Functioning (DIF) for these items was assessed using hybrid ordinal regression-IRT technique. When DIF was detected, the cumulative impact of DIF on individual subscale scores was evaluated. RESULTS: DIF was detected for 9 items within, between, or across cohorts, but the DIF was negligible in general. Detected DIF between the Swedish and Indian cohorts had a cumulative salient impact on individual scores for the subscale Disclosure Concerns; Disclosure concerns were overestimated in the Swedish cohort and both over- and underestimated in the Indian cohort. CONCLUSIONS: The items in the 32-item version of the HIV stigma scale did not seem to be particularly prone to present DIF. The DIF between the Indian and Swedish cohort for items in the subscale Disclosure Concerns could, however, result in both type I and type II errors if scores should be compared between the Indian and Swedish cohort

Differential item functioning for items in Berger's HIV Stigma Scale: an analysis of cohorts from the Indian, Swedish, and US contexts

PURPOSE: To examine whether items in Berger's HIV Stigma Scale function differently with persons of different age, gender, and cultural backgrounds. METHODS: Secondary data from cohorts, collected in South India (n = 250), Sweden (n = 193), and the US (n = 603) were reanalyzed to evaluate DIF within, between, and across these cohorts. All participants had answered the revised version of the HIV stigma scale consisting of 32 items forming the subscales Personalized stigma, Disclosure concerns, Concerns about public attitudes, and Negative self-image. Differential Item Functioning (DIF) for these items was assessed using hybrid ordinal regression-IRT technique. When DIF was detected, the cumulative impact of DIF on individual subscale scores was evaluated. RESULTS: DIF was detected for 9 items within, between, or across cohorts, but the DIF was negligible in general. Detected DIF between the Swedish and Indian cohorts had a cumulative salient impact on individual scores for the subscale Disclosure Concerns; Disclosure concerns were overestimated in the Swedish cohort and both over- and underestimated in the Indian cohort. CONCLUSIONS: The items in the 32-item version of the HIV stigma scale did not seem to be particularly prone to present DIF. The DIF between the Indian and Swedish cohort for items in the subscale Disclosure Concerns could, however, result in both type I and type II errors if scores should be compared between the Indian and Swedish cohort

Orange IV stabilizes silk fibroin microemulsions

Silk fibroin (SF) is a natural biopolymer that has been extensively studied in various applications due to its impressive mechanical properties and biocompatibility. Recently, SF-based particles have been proposed as controlled drug delivery systems. A new and efficient method to prepare SF microemulsions (SF-MEs) was developed by oil-in-water emulsions using high-pressure homogenization to promote emulsification. During SF-ME production, the secondary structure of SF changed to a more stable conformation (from random coil to -sheets), thus allowing the formation of small and stable (140.7 ± 1.9 nm; polydispersity index, 0.25) SF microparticles (SF-MPs). The efficiency of SF-MP formation was 60%. Orange IV was used as a model compound for incorporation and release studies, although its incorporation into the SF-MEs significantly improved particle size and size distribution over at least 4 wk compared to traditional stabilizers (e.g., poloxamer 407, transcutol, Tween 80, and SDS). This should be a call of attention when using dyes as model compounds since they can influence particle properties and lead to misinterpretation of the results. Orange IV showed an incorporation efficiency of 91% and a controlled release over time. Stable SF-MP formulations, further enhanced by orange IV incorporation, provide an innovative method with potential application in pharmaceutical development due to its associated high biocompatibility and release profile.The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project "BioHealth - Biotechnology and Bioengineering Approaches to Improve Health Quality," Ref. NORTE-07-0124-FEDER-000027, cofunded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER. We would also like to acknowledge CRA - Unita di Ricerca di Apicoltura and Bachicoltura Padova (Italy) for the supply of B. mori silkworm cocoons, and Andreia Vasconcelos for technical support