Improvement in flowability of thermo-chemical storage material by using nanostructured additives

Thermal energy storage is an advancing technology for storing energy that encourages clean energy systems without adversely affecting the environment. This technology allows us to use energy at different times by storing it temporarily. For example in a non-conventional energy source like solar thermal power plant, all its energy is produced during broad day light. The excess energy produced during a sunny day is usually stored in the thermal storage materials, which can later be used in the night to generate electricity. One such advantageous way of storing energy is through thermo-chemical storage. In a space craving society, high storage capability makes it an efficient way to store energy. However at present thermo-chemical storage is in its elementary stage, where in its limited to only one pilot scale system. Considering the thermodynamics and kinetics it has been shown that CaO/Ca(OH)2 reaction system is a potential gas/solid thermochemical heat storage system. However the behavior in a lab sized non-moving bed reactor was mainly dominated by heat and mass transfer limitations arising due to small particle size and changes in bulk properties. This was overcome to a certain level using a moving bed reactor but due to the change in the reactor type the flowability factor dominated adversely. Nevertheless during the recent studies at DLR it was found out that small amount of industrial grade SiO2 (Aerosil®) nanoparticles would enhance the flowability of Ca(OH)2 in a considerable way. But in contrast it effects the heat development leading to low thermal efficiency due to the formation of inert side products. In this study it is found out that small amount of nanostructured Al2O3 (Aeroxide®) not only plays a significant role in stabilizing cyclability and bulk properties but also contributes to the overall heat development

Automated background subtraction technique for electron energy-loss spectroscopy and application to semiconductor heterostructures

Electron energy-loss spectroscopy (EELS) has become a stan-dard tool for identification and sometimes also quantificationof elements in materials science. This is important for un-derstanding the chemical and/or structural composition ofprocessed materials. In EELS, the background is often mod-elled using an inverse power-law function. Core-loss ioniza-tion edges are superimposed on top of the dominating back-ground, making it difficult to quantify their intensities. Theinverse power-law has to be modelled for each pre-edge regionof the ionization edges in the spectrum individually ratherthan for the entire spectrum. To achieve this, the prerequisiteis that one knows all core losses possibly present. The aim ofthis study is to automatically detect core-loss edges, model thebackground and extract quantitative elemental maps and pro-files of EELS, based on several EELS spectrum images (EELS SI)without any prior knowledge of the material. The algorithmprovides elemental maps and concentration profiles by makingsmart decisions in selecting pre-edge regions and integrationranges. The results of the quantification for a semiconduc-tor thin film heterostructure show high chemical sensitivity,reasonable group III/V intensity ratios but also quantificationissues when narrow integration windows are used withoutdeconvolution

Effect of Sm3+ substitution on structural and magnetic investigation of nano sized Mn-​Sm-​Zn ferrites

Nano size Mn0.4Zn0.6SmxFe2-​xO4 (x = 0.00, 0.01, 0.02, 0.03, 0.04, and 0.05) ferrites were prepd. by soln. combustion method. The structural and magnetic properties of samples were characterised by X-​ray diffractometer, Fourier transform IR spectrometer, transmission electron micrographs and magnetic properties at room temp. The X-​ray diffraction patterns and two prominent absorption bands in the frequency range 375-​589 cm-​1 confirmed the single phase with spinel cubic structure. The av. nano crystallite sizes were in best agreements with transmission electron microscope images. Magnetic studies revealed the narrow hysteresis loops of ferrimagnetic nature at room temp. The values of satn. magnetization (Ms)​, remanence magnetization (Mr)​, coercivity (Hc)​, remanence ratio (Mr/Ms)​, magneton no., anisotropy const. and Yaffet-​Kittle angle decreased with the increase in Sm3+ ion concn. was attributed to relative no. of ferric ions on the tetrahedral sites diminished and reduced the Sm-​Fe interaction

Effect of Sm3+-Gd3+ on structural, electrical and magnetic properties of Mn-Zn ferrites synthesized via combustion route

Nanocrystalline Mn0.4 Zn0.6 SmxGdyFe2-(x+y)O4 (x = y = 0.01, 0.02, 0.03, 0.04 and 0.05) were synthesized by combustion route. The detailed structural studies were carried out through X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM). The results confirms the formation of mixed spine phase with cubic structure due to the distortion created with co-dopants substitution at Fe site in Mn-Zn ferrite lattice. Further, the crystallite size increases with an increase of Sm3+-Gd3+ ions concentration while lattice parameter and lattice strain decreases. Furthermore, the effect of Sm-Gd co-doping in Mn-Zn ferrite on the room temperature electrical (dielectric studies) studies were carried out in the wide frequency range 1 GHz-5 GHz. The magnetic studies were carried out using vibrating sample magnetometer (VSM) under applied magnetic field of 1.5T and also room temperature electron paramagnetic resonance (EPR) spectra's were recorded. From the results of dielectric studies, it shows that the real and imaginary part of permittivities are increasing with variation of Gd3+ and Sm3+ concentration. The magnetic studies reveal the decrease of remnant, saturation magnetization and coercivity with increasing of Sm3+-Gd3+ ion concentration. The g-value, peak-to-peak line width and spin concentration evaluated from EPR spectra correlated with cations occupancy. The electromagnetic properties clearly indicate that these materials are the good candidates which are useful at L and C band frequency. © 2015 Elsevier B.V

Structural and Magnetic Properties of Manganese Zinc Ferrite Nanoparticles Prepared by Solution Combustion Method Using Mixture of Fuels

The structural analysis and magnetic investigation Mn1−xZnxFe2O4 with stoichiometry (x=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) were synthesized by solution combustion method using mixture of fuel this is first of its kind. As synthesized Mn–Zn nanoferrites were characterized by X-ray Diffractometer (XRD), Transmission electron microscopy (TEM) at room temperature. The magnetic domain relaxation was investigated by inductance spectroscopy (IS) and the observed magnetic domain relaxation frequency (fr) was increased with the increase in grain size. The Room temperature magnetic properties were studied using vibrating sample magnetometer (VSM). It was observed that the real and imaginary part of permeability (µ' and µ?), saturation magnetization (Ms), remanance magnetization (Mr) and magneton number (Mr/Ms) were decreases gradually with increasing Zn2+ concentration. The decrease in the saturation magnetization may be explained as, the Zn2+ concentration increases the relative number of ferric ions on the A sites diminishes and this reduces the A–B interaction. Hence synthesized materials are good for high frequency applications

Attitudes of general dental practitioners towards biopsy procedures

Objectives: A dentist is required to detect and recognise oral lesions and inform the patient accordingly by providing a diagnosis and adequate treatment plan. Biopsy serves as an important aid in achieving this goal; however, its use is not so widespread in general dental practice. The objective of the present study was to explore the attitudes of general dental practitioners in Belgaum city towards biopsy for diagnosis of oral lesions. Material and methods: A self designed questionnaire was administered to 74 general dental practitioners in Belgaum city, in the southern region of India, consisting of several items addressing the socio-demographic and professional aspects and their attitudes towards oral biopsy procedures. Results: The response rate was exceptionally high i.e. 90.54%. All the dentists felt that biopsy was an important tool in diagnosis of oral lesions but many still did not venture to undertake it on their own and preferred referring it to a specialist or higher care centre. This was mainly due to lack of experience and patient factors. There were also conflicting results regarding referral diagnostic pathology services and preservation of the biopsy specimens. Conclusion: This emphasizes the need for higher levels of importance to be placed on this aspect in undergraduate and postgraduate dental curriculum. Organisation of specific training or continuing dental education programmes to enhance their practical skills could aid in increasing the utility of this important tool in diagnosis of oral lesion

Low temperature Mössbauer spectroscopic studies on Sm3+ doped Zn-Mn ferrites

For the first time, we report on the low temperature Mössbauer spectroscopic study of Zn2+ 0.5Mn2+ 0.5Sm3+ xFe3+ 2�xO4 (where x = 0.01�0.05) prepared by the modified solution combustion method using a mixture of urea and glucose as a fuel. The Mössbauer spectroscopy at room and low temperatures was applied to understand the magnetic properties of the samples. The room temperature Mössbauer spectroscopy results suggest that the occupation of the octahedral sites by Sm3+ ions leads to the distortion enhancement of 57Fe nuclei environments, which leads to an increase in quadrupole splitting � values of D2 and D3 doublets. The low temperature Mössbauer spectroscopy results indicate that the presence of Sm3+ ions in the octahedron sites causes the decrease in the number of Fe�O�Fe chains. The transformation of Mössbauer spectra doublets into Zeeman sextets is accompanied by a significant decrease in the magnitude IM of Mössbauer spectra intensity within the 0�1.2 mm/s velocity range normalized to its value at 300 K. This drop in the temperature dependence of IM allows one to obtain the magnetic phase transition temperature TM from the Mössbauer experiment. © 2017 Elsevier B.V

Comparative Analysis of Quagi and Yagi-Uda Antenna using 4NEC2 Tool

A Yagi-Uda antenna is one of the most widely used antenna in communication. Quagi antenna is a variation on vulnerable Yagi-Uda. Both the antennas are designed using 4NEC2 tool. Comparative analysis is being done on both 8-element Yagi-Uda antenna and 8-element Quagi antenna at 432 MHz frequency. A Quagi antenna is merely one of the most interesting amateur antenna designs to come down the pike in recent years. The need for low cost, high gain antenna for Moon bounce Communication, where moon is used as Passive communication satellite, inspired the development of Quagi antenna. Since Quagi is easy and non critical construction, cheap as well as simple, matching of feed line to the driven element, makes Quagi an attractive alternate to both Quad and Yagi-Uda antennas. At 432 MHz both Quagi and Yagi-Uda give almost same efficiency and gain, but Quad loop make an excellent driven element and reflectors, rods seem to be superior directors. So doing comparative analysis on both these antennas at 432 MHz would make sense and this made me to take up this topic

Role of Epidermal growth factor receptor in odontogenic epithelium and development of odontogenic lesions

Growth is a highly coordinated process which is sustained by several growth factors and apoptotic factors. Any disturbance in this delicate balance leads to pathologies and genes that have such potential to produce tumors when mutated are known as oncogenes. EGFR an important growth factor that is involved in several physiological processes is presently one of the most common genes in targeted cancer therapies. Though, its potential as an oncogene target in head and neck epithelial tumors like squamous cell carcinoma is gaining importance and opening doors to revolutionizing cancer treatment modalities, its role in other head and neck epithelia like odontogenic epithelia remains vague and needs attention. The present article highlights some of the key findings in our research evaluating the role of EGFR in physiologic odontogenic epithelium that is comprised within pericoronal follicles. The research involved study of immunohistochemical examination of 35 pericoronal follicles removed from patients with asymptomatic impacted tooth extractions. The follicles were assessed for intensity, percentage of staining and location of the EGFR stain. The follicles predominantly showed intense staining pattern and location of EGFR positivity in most epithelium and rests were combined both cytoplasmic and membrane positivity. These findings reemphasize the inherent proliferative potential present in follicles and their role in formation of odontogenic tumors like ameloblastomas in long term impacted teeth. The potential of EGFR as a treatment target in odontogenic tumors also remains plausible

A Study on Socio-Economic Factors Affecting Utilization of Maternal Health Care Services in Urban Community

Background: Even though the MMR dropped from 212 deaths per 100,000 live births in 2007-09 to 178 in 2010-12, India is behind the target of 103 deaths per live births to be achieved by 2015 under the United Nations-mandated Millennium Development Goals (MDGs).As per WHO, Three crucial factors understanding maternal deaths. Firstly lack of access and utilization of essential obstetric care. Secondly low social status of women in developing countries. Thirdly too much physical work together with poor diet also contributes to poor maternal outcomes. Out of these three factors, access and utilization of health care is the most crucial factor which is capable of reducing maternal morbidity and mortality. The present study was carried out to evaluate socio demographic correlates and barriers of maternal health care utilization in the urban community.    Objective:   To know the factors influencing the utilization of maternal health care services. METERIAL &METHODS; Study design: Cross sectional study. Area of study:   UHTC Kalal galli. Bijapur   (Urban field practice area)Participants: All married woman in the age group of 15-45 years who were either pregnant at the time of interview or delivered within last one year were included in the study.  Study period: January to March 2015Sample size: 134 mother Methods: Interview technique using pre tested   Proforma.   Statistical analysis: Percentage and chi-square test. Result: Utilization of maternal health services was found more among literate (70%) mothers compared to illiterate mothers. Utilization of maternal health services increased with increase in economic status. Major reasons for non-utilization of maternal service were not having a delivery complication in the past. (57%) Conclusion: The result reveals that educational level of women, exposure to mass media, birth order and wealth index are significant predictors in explaining the use of maternal health care services. There is a need of motivation and enhancing IEC activities for bringing desirable changes in the health care practice of the mother