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Ionising radiation are detected via optically stimulated luminescence (OSL). In optically stimulated luminescence (OSL), a preirradiated sample is excited by light in the visible/infrared region, which results in the detachment of either the hole or the electron. Recombination then causes the emission of radiation with a shorter wavelength than the exciting radiation. The best options for OSL phosphors are those materials that emit light with a wavelength between 350 and 425 nm and have strong photo-ionization cross sections in the blue-green (450–550 nm) or infrared (650–800 nm) regions. Since most fluorides satisfy these requirements when doped with ions like Cu, Ag, or Eu, they have been researched for use in OSL dosimeter development. Various fluorides include Fluoride pervoskites, ABF3 (A;, Na,K: B-Mg,Ca) fluorides with Colquiriite structure (LiCaAlF6), alkali silico fluorides, alkali fluorides, alkaline earth fluorides, and fluoride pervoskites were explored. The OSL in various fluorides is reviewed in this work along with how it can be used in OSL dosimetry. [ABSTRACT FROM AUTHOR]

The best practices activities are followed in many industries and institutes. Best practices activity increases the competence among members. The paper focused on project-based learning activities implemented for best practices activity. Project based learning activity provides step by step time bounded best practices activity. This activity helps to increase the ownership of individual member involved in best practices activity. The project-based learning activity implemented for development of energy saving through design and development of low-cost sun tube through reflectors. The project-based learning activity help to design and develop the innovative low-cost Sun tube useful for rural area, many industrial applications and community development. In this paper the Project Based Learning activity provided the 360-degree approach for the development of Sun tube. The paper focused a PBL activity step by step approach in implementation of low-cost sun tube. In this paper the best practices steps i.e. quality circle steps had followed with project-based learning activity. [ABSTRACT FROM AUTHOR]

Several Aluminium coumarinolates doped with various amounts of quinoline were studied. Normally pure coumarin along with the chelates show weak luminescence and the emission is observed around 450 nm along with emission around 350nm. Therefore such chelates don’t find any practical applications. Adding quinoline in small amount affects the emission and excitation of Al-Coumarin significantly. In most of these coumarinolates the emission is observed in blue green region with the excitation shifted in blue region. Of the several samples, sample doped with 40% quinoline shows the most intense emission. Thus this phosphor having intense emission along with good overlap of excitation with the near UV to blue emission of GaN based LED will find application as white phosphor in PCLED applications. The results are discussed in this paper. [ABSTRACT FROM AUTHOR]

The research investigation, effect of Rice Husk Ash on Concrete performed on laboratory scale, in which the (OPC) cement has been replaced by RHA with in terms of percentage by weight such as 12.5% and 25% of cement for 0.45 water/cement ratio. The laboratory analysis proved the compressive strength at 12.5% replacement of cement with RHA. This is the minimum content of RHA gives the better results in this study. Many of the analysis tests were performed such as, Standard consistency test, setting time test, soundness test, workability test and compressive strength test. This test proves the similarity of results obtained with the same laboratory conditions with OPC. The results were compared to controlled sample and the viability of adding RHA to concrete was verified. The minimum RHA content has been used as a pozzolanic material in cement and concrete. RHA provides several advantages, such as strength and durability properties, and environmental benefits related to the disposal of waste materials and to reduced carbon dioxide emissions. The use of RHA cement concrete improved stability reduced the heat generation and shrinkage. It strengthens transition zone i.e modifying the pore structure in the hydrated cement paste. [ABSTRACT FROM AUTHOR]

Most of the metal quinolate have broad excitation spectra is in range 385nm to 410 nm with emission spectra in the blue green region and hence can be easily pumped by the UV and near UV LEDS. However the emission efficiency is significantly low to make them suitable for any practical applications. Blending quinolates with polymers not only make them highly emissive but the emission and excitation can be tailored according to the requirement. Moreover the properties changes with the way in which blend is prepared, which are labeled as In-situ blending and Exsitu blending. In In-situ blending the Mgq2 is prepared in the polymer solution itself whereas in Ex-situ blending the previously prepared Mgq2 powder is dissolved in suitable solvent and mixed with the polymer. In this paper we report photoluminescence properties of Mgq2 and its composite film with PVOH. Green Yellow emission in Mgq2 powder is observed when excited by 385 nm LED whereas intense green emission is observed when excited by 400 nm LED. An Intense emission is observed in Mgq2 Ex-situ composites and observed emission is 7 times more with respect to powder. The Ex-situ composite shows near white emission when excited by 385 nm LED whereas blue green emission is observed when excited by 400 nm LED. In In-situ composites near white emission is observed when excited by 385 nm whereas blue emission is observed when excited by 400 nm LED. Thus these blended polymers may find application as white light phosphor for PCLED applications using near UV LEDs [ABSTRACT FROM AUTHOR]

In this work CaSO4:Eu2+ phosphor was synthesized with various molar solutions as 0.01M,0.1M,1M by co-precipitation method and the particle size effect on OSL sensitivity for CaSO4: Eu2+ samples has been studied. Synthesized phosphor was characterized by XRD, SEM, TEM and OSL measurements. Average particle size for 0.1 M and 0.01 M is found to be in the range 100nm-500nm and 80-100nm respectively with hexagonal morphology. The sample prepared with 0.1M solution shows maximum sensitivity with a slow decay of about 60 s. As the particle size reduced to 80-100nm range sample shows low OSL sensitivity with fast decay curve. For sample prepared with 1M solution, 66% reduction in OSL sensitivity is observed under identical conditions. The observed OSL in 0.1M sample compared with sensitivity of α-Al2O3: C (Landuer) and found to be 18 % using area integration method. It may find applications in radiation dosimetry using OSL techniques. [ABSTRACT FROM AUTHOR]

A colloidal mixture of nano-sized (<100 nm) particles in a base liquid called Nanofluid, which is the new generation of heat transfer fluid for various heat transfer applications where thermo-physical characteristics are substantially higher than the base liquid. In the present study, the effects due to temperature and concentration on thermo-physical properties (thermal conductivity, viscosity and density) for hybrid Nano fluids are discussed.The present work focuses on thermal conductivity and viscosity measurement of fluid mixture. This however, has not been addressed properly so far. It shows that thermal conductivity increases with nanoparticles concentration as well as with the temperature.Whereas,viscosity and density decreases with temperature and increases with nanoparticles concentration. Still more research is necessary to understand the mechanism behind the augmentation of heat transfer with hybrid nanofluids and to make use of hybrid nanofluids in real life applications. [ABSTRACT FROM AUTHOR]

In this work PL enhancement of CaSO4:Eu2+ nanophosphor which was synthesized with 0.01M molarity by co-precipitation method is presented. Synthesized phosphor was characterized by XRD, SEM, TEM and PL measurements. Average particle size is found to be in the range 80-100nm with Hexagonal morphology and PL studies showed emission peaks at 380nm, when samples were excited by 254nm. The observed PL emission is characteristic emission of Eu2+ similar to that observed in bulk CaSO4:Eu2. However under identical condition it is observed that intensity of emission get enhanced for 0.01M size which is doubled to that of 0.1M with similar emission at 380nm. A phosphor with narrow emission band around 390 nm is desirable, since at this wavelength the transmission of standard glass, polarizing plastic, other coating and LCD material is at acceptable level. Strong Eu2+ emission is observed in CaSO4:Eu nanophosphor which finds applications for PLLCD (photoluminescent liquid crystal display). [ABSTRACT FROM AUTHOR]