Raman spectra of ferro-electric crystals Part IV. Lithium hydrazinium sulphate (LiN2H5SO4)

The Raman spectrum of lithium hydrazinium sulphate has been recorded both in the single crystal form and in aqueous solutions. The crystal exhibits thirty-eight Raman lines having the frequency shifts 52, 70, 104, 146, 174, 220, 260, 302, 350, 454, 470, 610, 630, 715, 977, 1094, 1115, 1132, 1177, 1191, 1260, 1444, 1493, 1577, 1630, 1670, 2205, 2484, 2553, 2655, 2734, 2848, 2894, 2939, 3028, 3132, 3290 and 3330 cm.−1 The aqueous solution gave rise to six Raman lines at 452, 980, 1050–1200, 1260, 1425 and 1570 cm.−1 apart from a maximum at 180 cm.−1 in the ‘wing’ accompanying the Rayleigh line. The observed Raman lines have been assigned as arising from the vibrations of the SO4 ion, N2H5+ ion, Li-O4 group, hydrogen bond and the lattice. The influence of the hydrogen bond on the N-H stretching vibrations has been pointed out. The various features of the observed spectrum strongly support the hypothesis that the NH3 group in the crystal is rotating around the N-N axis at room temperature.

Differential synthesis of proteins by T4 phage and its head protein amber mutant

There was no difference in the incorporation of S-35 label into proteins of T4 and amber B17 phage grown on Escherichia coli B. The head protein peak was absent in the polyacrylamide gel electrophoretic profile of the S-35 labeled proteins of amber B17 grown on non-permissive host, E.coli B. However, an increase of 15–70% in the synthesis of other phage proteins of amber B17 over that of T4 phage was observed. The lysozyme activity increased by two fold in amber B17 in comparison with that of T4 phage grown on E.coli B. These results imply that in the absence of head protein synthesis by amber mutant there was an increase in the synthesis of other phage proteins.

Electron-beam melting and centrifugal splat-quenching technique for rapid solidification of titanium alloys

An electron-beam melting and centrifugal splat-quenching technique for the production of microflakes of Ti-6A1-4V (wt%) alloy quenched at an average cooling rate of about 105 K sec–1 is described. The effect of substrate angle on the shape, size, microstructure and average cooling rate of the flakes of major sieve fractions is discussed. Morphologies of particles of minor sieve fractions are dealt with briefly.

Temporal associations in fig-wasp-ant interactions: diel and phenological patterns

In a complex multitrophic plant-animal interaction system in which there are direct and indirect interactions between species, comprehending the dynamics of these multiple partners is very important for an understanding of how the system is structured. We investigated the plant Ficus racemosa L. (Moraceae) and its community of obligatory mutualistic and parasitic fig wasps (Hymenoptera: Chalcidoidea) that develop within the fig inflorescence or syconium, as well as their interaction with opportunistic ants. We focused on temporal resource partitioning among members of the fig wasp community over the development cycle of the fig syconia during which wasp oviposition and development occur and we studied the activity rhythm of the ants associated with this community. We found that the seven members of the wasp community partitioned their oviposition across fig syconium development phenology and showed interspecific variation in activity across the day-night cycle. The wasps presented a distinct sequence in their arrival at fig syconia for oviposition, with the parasitoid wasps following the galling wasps. Although fig wasps are known to be largely diurnal, we documented night oviposition in several fig wasp species for the first time. Ant activity on the fig syconia was correlated with wasp activity and was dependent on whether the ants were predatory or trophobiont-tending species; only numbers of predatory ants increased during peak arrivals of the wasps.

Thermal and electrical switching studies on Ge20Se80-xBix (1 <= x <= 13) ternary chalcogenide glassy system

Alternating Differential Scanning Calorimetric (ADSC) and electrical switching studies have been undertaken on Ge20Se80-xBix glasses (1 <= x <= 13), to understand the effect of topological thresholds on thermal properties and electrical switching behavior. It is found that the compositional dependence of glass transition temperature (Tg), crystallization temperature (T-c1) and thermal stability (AT) of Ge20Se80-xBix glasses show anomalies at a composition x= 5, the rigidity percolation/stiffness threshold of the system. Further, unusual variations are also observed in different thermal properties, such as T-g, T-c1, Delta T, Delta C-p and Delta H-NR, at the composition x= 10, which indicates the occurrence of chemical threshold in these glasses at this composition. Electrical switching studies indicate that Ge20Se8o_RBig glasses with 5 11 exhibit threshold switching behavior and those with x = 12 and 13 show memory switching. A sharp decrease has been noticed in the switching voltages with bismuth concentration, which is due to the more metallic nature of bismuth and the presence of Bi+ ions. Further, a saturation is seen in the decrease in V-T around x = 6, which is related to bismuth phase percolation at higher concentrations of Bi. (C) 2010 Elsevier B.V. All rights reserved.

"Musiikki merkitsee minulle paljon" : Asennetutkimus musiikin opiskelun merkityksellisyydestä peruskoulun 9. luokkalaisille

The main purpose of the Master Thesis was to find out what kind of attitudes the pupils in the 9th grade of Finnish comprehensive school have towards music as a school subject and compare it to the attitudes of the principals at a school level. The theoretical context of the research is based on the former studies of the significance of music education in the comprehensive school, the connection between learning and attitudes and the motivational factors towards the study motivation of music. In addition to this, I have analysed the role of the evaluation and the assessment from the point of view of developing the educational system and what is the role of management and leadership in relation to the pupils` behaviour and attitudes. The data of the research is the Finnish National Board of Education`s collected data of the assessment of the learning outcomes of arts education and it is nationally representative (N=5056 I phase and n=1570 II phase), both the Finnish-language and the Swedish-language pupil data. I have especially concentrated on the items of measuring the attitudes, the certain background variables and the questionnaire of the principals. The numerical data was analyzed using the multivariate statistical methods. The results of the research prove that in general the pupils and the principals think that music is quite significant as a school subject. The girls valued music on average more than the boys when comparing all the dimensions. The differences were systematic but the effect sizes were under 10 %. There were not statistically significant differences between the Finnish-language and the Swedish-language pupils. Comparing the grades of music in the 7th grade, the differences were growing linearly and the effect size was 15.7 %. There was a positive statistically significant correlation between the Significance of music and music as a hobby (Active interest in music, Informal interest in music, Taking part of music activities in the school) during free time. The strongest correlation were with the Active interest in music variable (r= 0.53, p= .000). Also the principals thought that music is important as a school subject considering the development of the pupil and the function of the school. The answers of the pupils were not clustering at a school level and there were no strong correlations between the attitudes of the pupils and the principals. A statistically nearly significant and a slight correlation (r= 0.21, p= .011) was found between the principals valuing the Significance of the music for school function and the pupils valuing the Benefits and hobbyism. The role of a well-motivated and active music teacher can be important from this point of view. The most important conclusion of the research was that the significance of music is a very personal individual level phenomenon. The results highlight also that in the pupils` opinion the most important thing about music lessons is to musical activity and learning as an experience.

A new quinone from Maesa indica (Roxb)A DC, (Myrsinaceae)

Isolation and structure elucidation of kiritiquinone, a new benzoquinone 2 5 dihydroxy-6-methyl 3 (hemeos 16-enyl)-1 4 benzoquinone from the frutis of Masca indica (Roxb) A DC is described

Thermodynamic properties of SmFeO3(S) and SM3R5O12(S)

The enthalpy increments and the standard molar Gibbs energy (G) of formation of SmFeO3(S) and SM3Fe5O12(s) have been measured using a Calvet micro-calorimeter and a solid oxide galvanic cell, respectively. A X-type transition, related to magnetic order-disorder transformation (antiferromagnetic to paramagnetic), is apparent from the heat capacity data at similar to673 K for SmFeO3(s) and at similar to560 K for Sm3Fe5O12(S). Enthalpy increment data for SmFeO3(s) and SM3Fe5O12(s), except in the vicinity of X-transition, can be represented by the following polynomial expressions: {H-m(0)(T) - H-m(0)(298.15 K){/J mol-(1)(+/-1.2%) = -54 532.8 + 147.4 . (T/K) + 1.2 . 10(-4) . (T/K)(2) +3.154 . 10(6) . (T/K)(-1); (298.15 less than or equal to T/K less than or equal to 1000) for SmFeO3(s), and {H-m(0)(T) - H-m(0)(298.15 K)}/J mol(-1) (+/-1.4%) = -192 763 + 554.7 . (T/K) + 2.0 . 10(-6) . (T/K)(2) + 8.161 . 10(6) - (T/K)(-1); (298.15 less than or equal to T/K less than or equal to 1000) for Sm3Fe5O12(s). The reversible emf of the solid-state electrochemical cells, (-)Pt/{SmFeO3(s) + Sm2O3(S) + Fe(s)) // YDT / CSZ // {Fe(s) + Fe0.95O(s)} / Pt(+) and (-)Pt/{Fe(s) + Fe0.95O(S)} // CSZ // {SmFeO3(s) + Sm3Fe5O12(s) + Fe3O4(s) / Pt(+), were measured in the temperature ranges of 1005-1259 K and 1030-1252 K, respectively. The standard molar G of formation of solid SmFeO3 and Sm3Fe5O12 calculated by the least squares regression analysis of the data obtained in the current study, and data for Fe0.95O and Sm2O3 from the literature, are given by: Delta(f)G(m)(0)(SmFeO3, s)/kj . mol(-1)(+/-2.0) = -1355.2 + 0.2643 . ; (1005 less than or equal to T/K less than or equal to 1570) and Delta(f)G(m)(0)(Sm3Fe5O12, s)/kj . mol(-1) (+/- 3.1) = -4891.0 + 1.0312 . (T/K); (1030 less than or equal to T/K less than or equal to 1252) The uncertainty estimates for Delta(f)G(m)(0) include the standard deviation in the emf and uncertainty in the data taken from the literature. Based on these thermodynamic data, the oxygen potential diagram for the system Sm-Fe-O was constructed at 1250 K.

End-bearing capacity of driven piles in sand using the stress characteristics method: analysis and implementation

The method of stress characteristics has been employed to compute the end-bearing capacity of driven piles. The dependency of the soil internal friction angle on the stress level has been incorporated to achieve more realistic predictions for the end-bearing capacity of piles. The validity of the assumption of the superposition principle while using the bearing capacity equation based on soil plasticity concepts, when applied to deep foundations, has been examined. Fourteen pile case histories were compiled with cone penetration tests (CPT) performed in the vicinity of different pile locations. The end-bearing capacity of the piles was computed using different methods, namely, static analysis, effective stress approach, direct CPT, and the proposed approach. The comparison between predictions made by different methods and measured records shows that the stress-level-based method of stress characteristics compares better with experimental data. Finally, the end-bearing capacity of driven piles in sand was expressed in terms of a general expression with the addition of a new factor that accounts for different factors contributing to the bearing capacity. The influence of the soil nonassociative flow rule has also been included to achieve more realistic results.

Antimicrobial Properties of Nanostructured TiO2 Plus Fe Additive Thin Films Synthesized by a Cost-Effective Sol-Gel Process

We prepared thin films composed of pure TiO2 or TiO2 with an Fe additive (at concentrations of 0.2-0.8 wt%) via a simple and cost effective sol gel process, and tested their antifungal properties (against Candida albicans (MTCC-1637), Candida tropicalis (MTCC-184), Candida parapsilosis (MTCC-2509), and Candida glabrata (MTCC-3019) and antibacterial properties (against Staphylococcus faecalis (NCIM-2604) Staphylococcus epidermidis (NCIM-2493), Staphylococcus aureus (NCIL-2122), and Bacillus subtilis (NCIM-2549)). The films were deposited on glass and Si substrates and subjected to annealing at 400 degrees C for 3 h in ambient air. The film structural and morphological properties were investigated by X-ray photoelectron spectroscopy profilometry and scanning electron microscopy, respectively. Antifungal and antibacterial tests were conducted using the drop test method. Among the species examined, Candida albicans (MTCC-1637), and Staphylococcus aureus (NCIL-2122) showed complete colony formation inhibition after exposure for 4 h for the TiO2 loaded with 0.8 wt% Fe thin films. These results indicate that increasing the Fe concentration increased the antimicrobial activity, with complete inhibition of colony formation after 4 h exposure.

Estimation of vapour pressure and partial pressure of subliming compounds by low-pressure thermogravimetry

A method for the estimation of vapour pressure and partial pressure of subliming compounds under reduced pressure, using rising temperature thermogravimetry, is described in this paper. The method is based on our recently developed procedure to estimate the vapour pressure from ambient pressure thermogravimetric data using Langmuir equation. Using benzoic acid as the calibration standard, vapour pressure temperature curves are calculated at 80, 160 and 1000 mbar for salicylic acid and vanadyl bis-2,4-pentanedionate, a precursor used for chemical vapour deposition of vanadium oxides. Using a modification of the Langmuir equation, the partial pressure of these materials at different total pressures is also determined as a function of temperature. Such data can be useful for the deposition of multi-metal oxide thin films or doped thin films by chemical vapour deposition (CVD).

On the mechanism and the length scales involved in the ductile fracture of a bulk metallic glass

Some bulk metallic glasses (BMGs) exhibit high crack initiation toughness due to shear band mediated plastic flow at the crack tip and yet do not display additional resistance to crack growth due to the lack of a microstructure. Thus, at crack initiation, the fracture behavior of BMGs transits from that of ductile alloys to that of brittle ceramics. In this paper, we attempt to understand the physics behind the characteristic length from the notch root at which this transition occurs, through testing of four-point bend specimens made of a nominally ductile Zr-based BMG in three different structural states. In the as-cast state, both symmetric (mode I) and asymmetric (mixed mode) bend specimens are tested. The process of shear band mediated plastic flow followed by crack initiation at the notch root was monitored through in situ imaging. Results show that stable crack growth occurs inside a dominant shear band through a distance of, similar to 60 mu m, irrespective of the structural state and mode mixity, before attaining criticality. Detailed finite element simulations show that this length corresponds to the distance from the notch root over which a positive hydrostatic stress gradient prevails. The mean ridge heights on fractured surfaces are found to correlate with the toughness of the BMG. The Argon and Salama model, which is based on the meniscus instability phenomenon at the notch root, is modified to explain the experimentally observed physics of fracture in ductile BMGs. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Yanai waves in the western equatorial Indian Ocean

Observations and models have shown the presence of intraseasonal fluctuations in 20-30-day and 10-20-day bands in the equatorial Indian Ocean west of 60 degrees E (WEIO). Their spatial and temporal structures characterize them as Yanai waves, which we label low-frequency (LFYW) and high-frequency (HFYW) Yanai waves, respectively. We explore the dynamics of these intraseasonal signals, using an ocean general circulation model (Modular Ocean Model) and a linear, continuously stratified model. Yanai waves are forced by the meridional wind tau(y) everywhere in the WEIO most strongly during the monsoon seasons. They are forced both directly in the interior ocean and by reflection of the interior response from the western boundary; interference between the interior and boundary responses results in a complex surface pattern that propagates eastward and has nodes. Yanai waves are also forced by instabilities primarily during June/July in a region offshore from the western boundary (52-55 degrees E). At that time, eddies, generated by barotropic instability of the Southern Gyre, are advected southward to the equator. There, they generate a westward-propagating, cross-equatorial flow field, v(eq), with a wave number/frequency spectrum that fits the dispersion relation of a number of Yanai waves, and these waves are efficiently excited. Typically, Yanai waves associated with several baroclinic modes are excited by both wind and eddy forcing; and typically, they superpose to create beams that carry energy vertically and eastward along ray paths. The same processes generate LFYWs and HFYWs, and hence, their responses are similar; differences are traceable to the property that HFYWs have longer wavelengths than LFYWs for each baroclinic mode.

Fe as Hydrogen/Halogen Bond Acceptor in Square Pyramidal Fe(CO)(5)

Hydrogen bonded complexes formed between the square pyramidal Fe(CO)(5) with HX (X = F, Cl, Br), showing X-H center dot center dot center dot Fe interactions, have been investigated theoretically using density functional theory (DFT) including dispersion correction. Geometry, interaction energy, and large red shift of about 400 cm(-1) in the FIX stretching frequency confirm X-H center dot center dot center dot Fe hydrogen bond formation. In the (CO)(5)Fe center dot center dot center dot HBr complex, following the significant red shift, the HBr stretching mode is coupled with the carbonyl stretching modes. This clearly affects the correlation between frequency shift and binding energy, which is a hallmark of hydrogen bonds. Atoms in Molecule (AIM) theoretical analyses show the presence of a bond critical point between the iron and the hydrogen of FIX and significant mutual penetration. These X-H center dot center dot center dot Fe hydrogen bonds follow most but not all of the eight criteria proposed by Koch and Popelier (J. Phys. Chem. 1995, 99, 9747) based on their investigations on C-H center dot center dot center dot O hydrogen bonds. Natural bond orbital (NBO) analysis indicates charge transfer from the organometallic system to the hydrogen bond donor. However, there is no correlation between the extent of charge transfer and interaction,energy, contrary to what is proposed in the recent IUPAC recommendation (Pure Appl.. Chem. 2011, 83, 1637). The ``hydrogen bond radius'' for iron has been determined to be 1.60 +/- 0.02 angstrom, and not surprisingly it is between the covalent (127 angstrom) and van der Waals (2.0) radii of Fe. DFT and AIM theoretical studies reveal that Fe in square pyramidal Fe(CO)(5) can also form halogen bond with CIF and ClH as ``halogen bond donor''. Both these complexes show mutual penetration as well, though the Fe center dot center dot center dot Cl distance is closer to the sum of van der Waals radii of Fe and Cl in (CO)5Fe center dot center dot center dot ClH, and it is about 1 angstrom less in (CO)(5)Fe center dot center dot center dot ClF.

Dynamics of the chemical bond: inter- and intra-molecular hydrogen bond

In this discussion, we show that a static definition of a `bond' is not viable by looking at a few examples for both inter-and intra-molecular hydrogen bonding. This follows from our earlier work (Goswami and Arunan, Phys. Chem. Chem. Phys. 2009, 11, 8974) which showed a practical way to differentiate `hydrogen bonding' from `van der Waals interaction'. We report results from ab initio and atoms in molecules theoretical calculations for a series of Rg center dot center dot center dot HX complexes (Rg = He/Ne/Ar and X = F/Cl/Br) and ethane-1,2-diol. Results for the Rg center dot center dot center dot HX/DX complexes show that Rg center dot center dot center dot DX could have a `deuterium bond' even when Rg center dot center dot center dot HX is not `hydrogen bonded', according to the practical criterion given by Goswami and Arunan. Results for ethane-1,2-diol show that an `intra-molecular hydrogen bond' can appear during a normal mode vibration which is dominated by the O center dot center dot center dot O stretching, though a `bond' is not found in the equilibrium structure. This dynamical `bond' formation may nevertheless be important in ensuring the continuity of electron density across a molecule. In the former case, a vibration `breaks' an existing bond and in the later case, a vibration leads to `bond' formation. In both cases, the molecule/complex stays bound irrespective of what happens to this `hydrogen bond'. Both these cases push the borders on the recent IUPAC recommendation on hydrogen bonding (Arunan et al. Pure. Appl. Chem. 2011, 83 1637) and justify the inclusive nature of the definition.