Zinc substituted manganese ferrites Mn1-xZnxFe2O4 (x = 0.1, 0.2, 0.3, 0.4 & 0.5 mol %) were successfully prepared by usual double ceramic route from high purity metal oxides and studied by means of X-ray diffraction and magnetization measurements. The formation of mixed spinel phase has been confirmed by X-ray diffractograms. The unit cell parameter 'a' decreases linearly with the substitution of zinc content and is due to the small ionic radius of zinc. The saturation magnetization of all the samples were determined at 300K by Vibrating Sample Magnetometer (VSM) and found to decrease linearly with increasing zinc content (x). The cation distribution of the present ferrite system has been calculated from X-ray intensity calculations and magnetization measurements. The variation of saturation magnetic moment per formula unit decreases with increasing zinc concentration (x), suggesting the existence of collinear magnetic structure. The collinear magnetic structure in the present ferrite system is also verified by Neel's two-sublattice model.

Learning to program could possibly be analogous to acquiring expertise in abstract mathematics, which may be boring or dull for a majority of students. Thus, among the countless options to approach learning coding [1-14], acquiring concepts through game creation could possibly be the most enriching experience for students. Consequently, it is important to select a lucid and familiar game for students. Then, the following step is to choose a language that introduces the basic concepts of object-oriented programming really well. For this paper, we chose the game of Tic-Tac-Toe, which is straight-forward for most people. The programming language chosen here is C++.

Increasing chromium substitution in Co-Cd ferrites, synthesized via sol-gel auto-combustion method, remarkably influences their structural, magnetic and electrical properties. As the Cr3+ concentration is increased, various interesting changes in the values of structural parameters like X-ray density, bulk density and porosity have been observed. The value of lattice constant, is found to be similar to 8.38 angstrom with an average crystallite size of similar to 50 nm. The porosity in the entire ferrite samples is low (5.3%-6.9%). The magnetic properties, like saturation magnetization and coercivity, show a decrease trend with increase in Cr3+ concentration. The proposed cation distribution is further substantiated by the electrical properties. It is observed that the d.c. resistivity increases with Cr3+ concentration, suggesting occupancy of Cr3+ ions in the B-sites which leads to the dilution of Fe2+-Fe3+ conduction. The activation energy calculated from the d.c. resistivity vs temperature curves is found to be similar to 0.25 eV. (C) 2013 Elsevier B.V. All rights reserved.

Traditional medicinal knowledge has gained much attention recently due to rejuvenation of faith in traditional system of medicines. The Indian Himalaya is a source of plant based indigenous medicinal knowledge based on local plant diversity. Surveys were conducted in Rudraprayag district of Uttarakhand, India to collect indigenous information on primary health care. 29 formulations using 159 plant species were recorded treating 119 ailments in 13 broad therapeutic classes. Results have been compared with traditional knowledge from other parts of India.

Synthesis of non-collinear (spin canted) ferrites having the formula, CoCd x Fe 2 − x O 4 ( x = 0·0, 0·2, 0·4, 0·6, 0·8 and 1·0), has been carried out using the sol–gel auto combustion method. The ferrite samples show an interesting magnetic transition from Neel to Yafet–Kittel configuration, as the Cd 2 + concentration is increased beyond x = 0·4. The FT–IR spectra confirm the formation of the metal oxide bond as they exhibit two frequency bands in the range of ~595 cm − 1 and ~450 cm − 1 , corresponding to the tetrahedral and the octahedral stretching vibrations of the metal oxide, respectively. The structural evolutions of the nanophase investigated using powder X-ray diffraction (XRD) technique show that the average crystallite size is ~ 35 nm. The magnetic studies reveal that the saturation magnetization, M s , increases up to x = 0·4 and decreases when the value of x is >0·4. It is proposed that the incorporation of Cd 2 + ion takes place into the tetrahedral sites and up to x = 0·4, Neel’s model is followed. But for x > 0·4, canting of spins occurs, as explained by Yafet–Kittel (Y–K) model. The d.c. resistivity decreases as a function of temperature, indicating semiconducting nature of the ferrites and the positive value of Seebeck coefficient establishes p -type conduction behaviour for all the ferrite samples.

Sol–gel method is used to prepare BaAlFe11O19 hexaferrites, and the morphology of the samples has been changed by mixing the as obtained samples with inorganic template agents (KCl, KBr, and KI) during the annealing process. Fourier transform infrared spectroscopy (FTIR) frequency bands in the range 564–588 cm−1 and 425–442 cm−1 are corresponding to the formation of tetrahedral and octahedral clusters of metal oxides respectively. X-ray powder studies do not show any peak for the as obtained sample, however, regular X-ray diffraction (XRD) peaks were obtained for the samples annealed at 1000°C. Magnetic measurement shows that the saturation magnetization (Ms) of BaAlFe11O19/KI is maximum (24.32 emu/g) and of BaAlFe11O19/KCl is minimum (9.47 emu/g). The coercivity (Hc) values of the sample with KCl is maximum (3237 Oe) and of the sample with KI is minimum (700 Oe).

The structural, magnetic, electrical and optical properties of chromium substituted cobalt ferrites (CoCrxFe2−xO4, x=0.2, 0.4, 0.6, 0.8 and 1.0), have been investigated and on the basis of the saturation magnetization values, the cation distribution in the ferrite samples has been proposed. It is suggested that both Co2+ ions as well as Cr3+ ions seek to the octahedral sites of the ferrite sub-lattice. However, a small amount of Co2+ ions are also incorporated in the tetrahedral sites of the ferrite sub-lattice. This causes a decrease in the saturation magnetization (Ms) values with increasing Cr3+ concentration. The increase in Cr3+ ion composition in the ferrite sample decreases the value of saturation magnetization from 77emu/g to 13emu/g, indicative of the fact that the lesser magnetic Cr3+ ions substitute Fe3+ ions in the octahedral sub-lattice of the ferrites. A significant decrease in the saturation magnetization is observed in CoCrFeO4, attributing to the weakening of the A–B interaction as iron enters into the A site. The magnetic moments calculated from the proposed cation distribution (using Neel’s two sub-lattice model) are in conformity with those obtained from Ms values. The effect of annealing temperature on structural, magnetic, electrical and optical properties has also been investigated.

Due to the recent popularity of mobile devices from Apple and Microsoft, there is a surge in interest to develop applications for the latest version of iOS in Objective-C and Windows Phone in C#. It is the perfect time for the academic community to offer expertise in mobile software development to prepare their students for a highly-competitive, global workplace. It is well-known that Objective-C has a steep learning curve as it is based on C and Smalltalk. On the other hand, C# is a hybrid of C++ and Java. With this in mind, a comparison of Objective-C and C# is presented in this paper. After gaining familiarity with the syntax of C#, one can easily transfer that expertise to develop in Objective-C from existing C# code, and vice versa.

Suborder Auchenorrhyncha includes short-horned bugs, having antennae usually small and inconspicuous; when long, they appear slender and filamentous or two segmented. Present study reports 53 species belonging to 37 genera and 8 families of suborder Auchenorrhyncha from Madhya Pradesh and Chhattisgarh. Of these, Infraorder Cicadomorpha represents 44 species, including 10 species belonging to 7 genera of family Cicadidae, 4 species belonging to 4 genera of Superfamily Cercopoidea, 30 species belonging to 20 genera of family Cicadellidae, while Infraorder Fulgoromorpha represents 9 species belonging to 6 genera of Superfamily Fulgoroidea. Present paper also includes 9 new records from Madhya Pradesh and 10 new records from Chhattisgarh.

This paper defines how similarity assessment to the scene level extends. Geographic scene matching problems (GSMP) present several variations depending on the types of the scene query and the underlying database .virtually irrelevant for simpler levels of representation is how to associate parts of one scene with corresponding parts of another scene. Therefore, it is important to recognize what those parts are under a geographic setting, and what the principles are that should guide the correspondences amongst them. Aspects of geographic domain knowledge are also implicit in the form in which a spatial query is expressed, since different forms of input may suggest alternative distributions of significance to the various components, thereby affecting similarity.

Nano-sized Cd-doped lithium ferrite LiCdxFe5−xO8 (0.0⩽x⩽1.0) powders were prepared using the sol–gel method. Thermal analysis showed the formation of LiFe5O8 ferrite around 440°C and the Cd-doped lithium ferrites have been found to have better thermal stability due to the delta phase evolution. The evolution of δ-LiFe5O8 as a secondary phase has been confirmed by XRD, for all the samples above Cd content x⩾0.3, with formation of pure δ-LiFe5O8 for the composition x=0.5 only. The decrease of DC resistivity with temperature can be attributed to the semiconducting nature for all the samples. The DC resistivity also increased with Cd-content, attributing to the decrease in polaron hopping between Fe3+ and Fe2+ ions. The drift mobility showed an increasing trend with temperature, because of the hopping of charge carriers from one site to another with increasing temperature. Pure LiFe5O8 has saturation magnetization (Ms) equal to 59.55Am2/kg, which on doping with Cd, first increases and then shows a decreasing trend. Conversely, coercivity (Hc) first decreases and then increases with Cd doping.

Cobalt-substituted nickel chromium ferrites (FeO 4 , ) have been synthesized using sol-gel autocombustion method and annealed at 400 °C, 600 °C, 800 °C, and 1000 °C. All the ferrite samples have been characterized using UV-VIS spectrophotometery, FT-IR spectroscopy, Transmission Electron Microscopy, powder X-Ray Diffraction, and magnetic measurements. Typical FT-IR spectra of the samples annealed at 400°C, 600°C, 800°C, and 1000°C exhibit two frequency bands in the range of ~ 480 cm −1 and ~ 590 cm −1 corresponding to the formation of octahedral and tetrahedral clusters of metal oxide, respectively. TEM images reveal that crystallite size increases from ~ 10 nm to ~ 45 nm as the annealing temperature is increased from 400°C to 1000°C. The unit cell parameter “a” is found to increase on increasing the cobalt concentration due to larger ionic radius of cobalt. Also, as the cobalt concentration increases, the saturation magnetization increases from 4.32 to 19.85 emu/g. This is due to the fact that cobalt ion replaces the less magnetic nickel ions. However, the coercivity decreases with increase in cobalt concentration due to the decrease in anisotropy field. The band gap has been calculated using UV-VIS spectrophotometry and has been found to decrease with the increase of particle size.

Cobalt-substituted nickel chromium ferrites (CrCo𝑥Ni1−𝑥FeO4, 𝑥=0,0.2,0.4,0.6,0.8,1.0) have been synthesized using sol-gel autocombustion method and annealed at 400 °C, 600 °C, 800 °C, and 1000 °C. All the ferrite samples have been characterized using UV-VIS spectrophotometery, FT-IR spectroscopy, Transmission Electron Microscopy, powder X-Ray Diffraction, and magnetic measurements. Typical FT-IR spectra of the samples annealed at 400°C, 600°C, 800°C, and 1000°C exhibit two frequency bands in the range of ~480 cm−1 and ~590 cm−1 corresponding to the formation of octahedral and tetrahedral clusters of metal oxide, respectively. TEM images reveal that crystallite size increases from ~10 nm to ~45 nm as the annealing temperature is increased from 400°C to 1000°C. The unit cell parameter “a” is found to increase on increasing the cobalt concentration due to larger ionic radius of cobalt. Also, as the cobalt concentration increases, the saturation magnetization increases from 4.32 to 19.85 emu/g. This is due to the fact that cobalt ion replaces the less magnetic nickel ions. However, the coercivity decreases with increase in cobalt concentration due to the decrease in anisotropy field. The band gap has been calculated using UV-VIS spectrophotometry and has been found to decrease with the increase of particle size.

Chromium substituted strontium ferrites SrCrxFe12−xO19 (x=0.5, 1.0, 1.5, 2.0 and 2.5) have been synthesized via sol gel method and the dry gels obtained have been annealed with various inorganic template agents (KCl, KBr and KI). The powder X ray diffraction studies reveal a crystallite size of ~40–45nm. The use of KCl as inorganic template agent leads to an increase in the crystallite size. This may be attributed to the fact that the coordination ability of Cl− is maximum due to its larger charge to size ratio, which promotes crystal growth in one dimension leading to needle-like morphology. On the other hand, KI undergoes sublimation to form I2 which gets entrapped in the strontium ferrite crystal leading to a bubble-like morphology. A systematic change in the lattice constants, a and c, is not observed because the radius of Cr3+ ion (0.63Å) is similar to that of Fe3+ ion (0.64Å). The saturation magnetization decreases with increase in the chromium concentration from 43.03emu/g to 17.40emu/g due to the substitution of Fe3+ ions by less magnetic Cr3+ ions in 2a and 12k sites of the lattice. The coercivity decreases with increase in the chromium concentration due to decrease in magnetocrystalline anisotropy. In the presence of KCl and KBr, both saturation magnetization and coercivity increase and the saturation magnetization has the maximum value in case of samples annealed with KBr. However, with KI, the values of both saturation magnetization and coercivity decrease sharply which may be due to lower crystallinity due to bubble-like morphology because of the decomposition of KI to I2. The energy band gap for all the ferrite compositions is found to be ~2.2eV and its value increases in the samples annealed with KI.

Data retention and leakage current are among the major area of concern in today's CMOS technology. In this paper 6T SRAM cell has been analyzed on the basis of read noise margin (RNM), write noise margin (WNM), read delay, write delay, and data retention voltage (DRV). Implementation and simulation is carried out using VHDL. The word static indicates that the memory retains its contents as long as power remains applied. SRAM indicates that locations in the memory can be accessed, i.e. written or since it is volatile memory and preserves data only while power is continuously applied. Each bit in SRAM is stored in four transistors that form two cross-coupled inverters. This storage cell has two stable states which are used to denote '0' and '1'. Two additional access transistors serve to control the access to a storage cell during read and write operations. It thus typically takes six MOSFETs to store one memory bit. The data retention voltage for 6T SRAM cell comes to be 252.3mV. The higher read delay is attributed to the fact that dual threshold voltage technology has been in it in the order to reduce the leakage current. Write delay has found to be 8.57 ps. Keywords- 6T SRAM cell; VHDL; Data retention voltage; Read noise margin; Write noise margin; Intrinsic parameter fluctuation.

M-type nano hexaferrites MFe12O19 and MAlFe11O19 (M=Sr, Ba and Pb) have been prepared by the sol–gel method to investigate the shielding effect of inorganic ions KCl, KBr and KI on the phase growth of ferrites. FTIR frequency bands in the range 560–580cm−1 and 430–470cm−1corresponds to the formation of tetrahedral and octahedral clusters of metal oxides in ferrites, respectively. X-ray powder diffractographs do not show any peaks for the as obtained samples showing the amorphous nature of the samples, however regular peaks for M-type structure have been obtained for all the annealed samples. There is negligible small change in the lattice parameters ‘a’ and ‘c’ with substitution of the hexagonal ferrites with aluminium. Magnetic measurements showed that the coercivity (Hc) values of all the samples with KCl and KBr enhance due to KCl and KBr to act as deactivators. However, the coercivity value decreases with KI as it oxidise to I2 during annealing. The saturation magnetization of the hexaferrites decreases with Al3+ ion substitution for Fe3+ ion due to preferential occupancy of aluminium in octahedral sites.

Zinc substituted cobalt ferrite nanoparticles (CoxZn1-xFe2O4, with x = 0.0, 0.2, 0.4, 0.8 and 1.0) were prepared via sol-gel route and the effect of zinc concentration on saturation magnetization and lattice parameter were investigated. The particle sizes of the as obtained samples were found to be ~10 nm which increases upto ~92 nm on annealing at 1000oC. The frequency bands near 564-588 cm-1 and 425-442 cm-1 are assigned to the tetrahedral and octahedral clusters which confirm the presence of M-O stretching band in ferrites. The unit cell parameter 'a' increases linearly with increasing concentration of zinc due to larger ionic radii of Zn2+ ion . It was found that this substitution allows tunable changes in the magnetic properties of cobalt ferrite. Interestingly, saturation magnetization first increases upto x = 0.4 and then decreases for higher Zn substitution, thus tunable changes in magnetic properties of cobalt ferrite are possible. Source of such behaviour could be the variation of exchange interaction between the tetrahedral and the octahedral sites.

Nano size lithium ferrite was prepared through aerosol route and characterized using TEM, XRD, magnetic measurements and Mössbauer spectroscopy. The particle size of as obtained samples were found to be ~10 nm through TEM, that increases upto ~80 nm on annealing at 1200 oC. The unit cell parameter ‘a’ calculated using XRD, confirms the formation of ?-LiFe5O8. Room temperature Mössbauer spectra of as obtained sample of all the ferrites exhibited broad doublet suggesting super paramagnetic nature. This doublet further resolved into two doublets and assigned to the surface region atoms and internal region atoms of the particles. The annealed samples (1200 oC) show broad sextets, which were fitted with two sextets indicating different local environment of both tetrahedrally and octahedrally coordinated Fe-cation. Cation distribution obtained from the X-ray, magnetic and Mössbauer data confirms that the three fifth of the iron atom goes in to the octahedral site.

Nano size composite of x(NiFe2O4)+(1−x)(SrFe12O19) were prepared using sol gel and aerosol route. The percentage of the components of NiFe2O4 and SrFe12O19 calculated from X-ray diffraction pattern using Rietveld analysis. The hysteresis loop for the as obtained samples exhibits no hysteresis, which may be attributed to super paramagnetic relaxation. The saturation magnetization do not show a significant change with the increase of strontium ferrites, however, the coercivity increased from 115 to 6,000 Oe. The Mössbauer spectra of these nano composites were discussed along with the magnetic moment and X-ray results.