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Nematic fluctuations occur in a wide range of physical systems from liquid crystals to biological molecules to solids such as exotic magnets, cuprates and iron-based high-$T_c$ superconductors. Nematic fluctuations are thought to be closely linked to the formation of Cooper-pairs in iron-based superconductors. It is unclear whether the anisotropy inherent in this nematicity arises from electronic spin or orbital degrees of freedom. We have studied the iron-based Mott insulators La$_{2}$O$_{2}$Fe$_{2}$O$M$$_{2}$ $M$ = (S, Se) which are structurally similar to the iron pnictide superconductors. They are also in close electronic phase diagram proximity to the iron pnictides. Nuclear magnetic resonance (NMR) revealed a critical slowing down of nematic fluctuations as observed by the spin-lattice relaxation rate ($1/T_1$). This is complemented by the observation of a change of electrical field gradient over a similar temperature range using M\"ossbauer spectroscopy. The neutron pair distribution function technique applied to the nuclear structure reveals the presence of local nematic $C_2$ fluctuations over a wide temperature range while neutron diffraction indicates that global $C_{4}$ symmetry is preserved. Theoretical modeling of a geometrically frustrated spin-$1$ Heisenberg model with biquadratic and single-ion anisotropic terms provides the interpretation of magnetic fluctuations in terms of hidden quadrupolar spin fluctuations. Nematicity is closely linked to geometrically frustrated magnetism, which emerges from orbital selectivity. The results highlight orbital order and spin fluctuations in the emergence of nematicity in Fe-based oxychalcogenides. The detection of nematic fluctuation within these Mott insulator expands the group of iron-based materials that show short-range symmetry-breaking.

The cubic double perovskite Ba$_2$YIrO$_6$ has been investigated by the local probe techniques nuclear magnetic resonance ($^{89}$Y NMR) and muon spin rotation (muSR). Both methods confirm the absence of magnetic long-range order in this compound but find evidence for diluted localized paramagnetic moments. NMR spin-lattice relaxation rate 1/T1 measurements suggest a slowing down of localized spin moments at low temperatures. An increase of the muSR spin-lattice relaxation rate lambda confirms the presence of weak magnetism in Ba$_2$YIrO$_6$ . However, these findings cannot be explained by the recently suggested excitonic type of magnetism. Instead, they point towards tiny amounts of localized paramagnetic spin centers leading to this magnetic response on the background of a simple nonmagnetic ground state of the 5d$^4$ ($J=0)$ electronic configuration of Ir$^{5+}$., Comment: 8 pages, 7 figures

We report the structural, magnetic, and thermodynamic properties of the double perovskite compound ${\mathrm{La}}_{2}{\mathrm{CuIrO}}_{6}$ from x-ray, neutron diffraction, neutron depolarization, $\mathit{dc}$ magnetization, $\mathit{ac}$ susceptibility, specific heat, muon-spin-relaxation $(\ensuremath{\mu}\mathrm{SR})$, electron-spin-resonance (ESR) and nuclear magnetic resonance (NMR) measurements. Below $\ensuremath{\sim}113$ K, short-range spin-spin correlations occur within the ${\mathrm{Cu}}^{2+}$ sublattice. With decreasing temperature, the ${\mathrm{Ir}}^{4+}$ sublattice is progressively involved in the correlation process. Below $T=74$ K, the magnetic sublattices of Cu (spin $\mathit{s}=\frac{1}{2}$) and Ir (pseudospin $\mathit{j}=\frac{1}{2}$) in ${\mathrm{La}}_{2}{\mathrm{CuIrO}}_{6}$ are strongly coupled and exhibit an antiferromagnetic phase transition into a noncollinear magnetic structure accompanied by a small uncompensated transverse moment. A weak anomaly in $\mathit{ac}$ susceptibility as well as in the NMR and $\ensuremath{\mu}\mathrm{SR}$ spin lattice relaxation rates at 54 K is interpreted as a cooperative ordering of the transverse moments which is influenced by the strong spin-orbit coupled $5\mathit{d}$ ion ${\mathrm{Ir}}^{4+}$. We argue that the rich magnetic behavior observed in ${\mathrm{La}}_{2}{\mathrm{CuIrO}}_{6}$ is related to complex magnetic interactions between the strongly correlated spin-only $3\mathit{d}$ ions with the strongly spin-orbit coupled $5\mathit{d}$ transition ions where a combination of the spin-orbit coupling and the low symmetry of the crystal lattice plays a special role for the spin structure in the magnetically ordered state.

A new general method for the synthesis of acridine-1,8-diones through CDC coupling of enamino-ketones followed by rearrangement has been developed. This is a Cu(i) catalyzed procedure, based on the cross dehydrogenative coupling of the Csp(3)-H bond with the Csp(2)-H bond of enamino-ketones followed by rearrangement to acridine-1,8-diones in the presence of PTSA under an aerobic atmosphere. The synthetic route has been broadly applicable to a wide range of enamino-ketone derivatives derived from different benzyl amines as well as primary aliphatic amines having Cα(sp(3))-H bonds with various cyclic, acyclic 1,3-diketones and also using DEAD.

The seismic behavior of pile groups is very complicated if piles are passing through liquefiable soil. In this paper, the effects of soil nonlinearity and liquefaction on seismic response of pile groups are investigated. A three-dimensional finite element soil-pile model was developed with Kelvin elements for simulating radiation conditions at infinity. The effect of soil nonlinearity was investigated considering work-hardening plastic cap model for the soil. The liquefaction of the soil medium was simulated using two parameter volume change model. Seismic responses of a single pile and pile groups were examined considering soil nonlinearity and liquefaction. The study was performed for range of frequency of excitation. Finally analysis is carried out for real time earthquake motion. A significant effect of soil nonlinearity and liquefaction of the soil medium on the seismic response of pile groups was observed and it was also noticed that this effect is very much dependent on peak ground...

Determination of the behavior of pile groups under dynamic condition is a complex problem. The complexity becomes more intricate when the soil medium surrounding the piles behaves nonlinearly due to higher cyclic loading under dynamic condition. Further if the soil is saturated then the behavior of pile groups is also affected due to liquefaction. In this paper, nonlinear dynamic analyses of pile groups have been performed with and without generation of pore water pressure. A three-dimensional finite element soil-pile model has been developed with proper radiation boundary conditions. Frequency dependent Kelvin elements have been used for simulating radiation conditions at infinity. The numerical model and the process of computation have been verified with the established literature. For soil nonlinearity, work-hardening plastic cap model has been considered for further investigation. The pore pressure generation for liquefaction has been incorporated by two-parameter volume change model ...

Separation and sliding between soil and pile have a significant effect on the complex behavior of pile groups under dynamic condition. In addition to separation between soil and pile, the behavior of soil medium surrounding the piles is nonlinear during strong excitations. Therefore, soil is modeled using a nonlinear work-hardening plastic cap model. Because of shaking, there is an increase in pore water pressure. To simulate it, the pore-pressure generation capability is added in modeling the behavior of the soil medium. A full three-dimensional finite-element soil-pile model has been developed with approximate radiation condition at infinity simulated by frequency dependent Kelvin elements. The model and the process of computation have been verified with the established literature. The effects of separation on the dynamic stiffness and seismic response of single pile and pile groups have been examined considering work-hardening soil-plasticity without and with pore-pressure generation capability for a wide range of frequencies of excitation. Real-time earthquake motions are also applied and the effects of separation on the responses of pile groups are investigated. Significant effects of separation of the soil medium on the response of the soil-pile system have been observed and approximately quantified.

The liver stiffness measure (LSM) needs to be explored in ethnically and anthropometrically diverse healthy subjects (to derive an acceptable normal range) and also in patients with liver disease. In view of this objective, LSM was performed by transient elastography (TE) using FibroScan in 437 healthy subjects with normal alanine aminotransferase (ALT) levels, recruited from a free-living population of the Birbhum Population Project (BIRPOP; www.shds.in), a Health and Demographic Surveillance System (HDSS), and from 274 patients with liver disease attending the Hepatology Clinic of the School of Digestive and Liver Diseases (SDLD; Institute of Post Graduate Medical EducationResearch [IPGMER], Kolkata, India) including 188 with nonalcoholic fatty liver disease (NAFLD) and 86 with chronic hepatitis of viral and other etiologies. Liver biopsy was performed in 125 patients. The range of normal values for LSM, defined by 5th and 95th percentile values in healthy subjects, was 3.2 and 8.5 kPa, respectively. Healthy subjects with a lower body mass index (BMI;18.5 kg/m(2)) had a higher LSM compared with subjects who had a normal BMI; this LSM value was comparable to that of obese subjects (6.05 ± 1.78 versus 5.51 ± 1.59 and 6.60 ± 1.21, P = 0.016 and 0.349, respectively). Liver disease patients without histologic fibrosis had significantly higher LSM values compared with healthy subjects (7.52 ± 5.49 versus 5.63 ± 1.64, P0.001). Among the histologic variables, stage of fibrosis was the only predictor for LSM. LSM did not correlate with inflammatory activity and ALT in both NAFLD and chronic hepatitis groups.LSM varies between 3.2 and 8.5 kPa in healthy subjects of South Asian origin. Both lean and obese healthy subjects have higher LSM values compared with subjects with normal BMI. Liver stiffness begins to increase even before fibrosis appears in patients with liver disease.

Nonlinearity of the soil medium plays a very important role on the seismic behavior of soil-pile-structure interaction. The problem of soil-pile-structure interaction is further complicated when the piles are embedded in liquefiable soil medium. A finite-element code was developed in MATLAB to model three-dimensional soil-pile-structure systems. Frequency dependent Kelvin elements (spring and dashpots) were used to model the radiation boundary conditions. A work-hardening plastic cap model was used for constitutive modeling of the soil medium. The pore pressure generation for liquefaction was incorporated by a two-parameter volume change model reported in the literature. In this paper, a 2×2 pile group in liquefiable soil is considered and a parametric study is conducted to investigate its seismic behavior. The effects of loading intensity and stiffness of the soil on the seismic behaviour of the soil-pile system are investigated, considering nonlinearity and liquefaction of the soil medium for a wide ran...

The crystal electric field (CEF) scheme of YbNi4P2 is determined, based on experimental data from inelastic neutron scattering, heat capacity, susceptibility and NMR measurements. Despite the tetragonal crystal structure, 9 parameters are needed to describe the crystal field in YbNi4P2 due to the orthorhombic site symmetry of the Yb ion. A large basal plane anisotropy is detected by the local probe NMR. Our analysis yields CEF excitation energies of 8.5, 12.5 and roughly 30 meV and a ground state wave function that is dominated by the $5/2$ state. Furthermore, we present an analysis of the CEF scheme based on density functional theory calculations, which confirms the large basal plane anisotropy.

P 31 NMR in S = 1 2 linear cluster compound Sr 3 Cu 3 ( PO 4 ) 4 was investigated. At any temperature, the spectrum corresponds to a typical overlap of two powder patterns, consistent with two inequivalent phosporous sites, having different components of the shift parameters. Intra-trimer exchange ( J 1 = 110 ± 5 K ) and hyperfine field ( H hf ) were directly obtained from temperature dependence of K iso , considering S = 1 2 , Heisenberg linear trimer. The behavior of the H hf for the two sites are quite different and reflects the formation of trimers below 100 K. The relaxation rate, 1 / T 1 in the range 100–210 K, shows an activation ( Δ / k B = 43 K ) dependence of the spin excitation.

A comparative study of the magnetic properties of a few members of the Ln {sub 0.5}Sr{sub 0.5}CoO{sub 3} family with different radii of the A-site cations, , in the range 1.19-1.40 A has been carried out. The apparent T {sub c} (where the magnetization undergoes an abrupt increase) decreases markedly with as well as the size-disorder arising from the mismatch in the size of the A-site cations. The value of the magnetization at low temperatures decreases markedly with decrease in or increase in size-disorder, suggesting that the relative proportion of the ferromagnetic (FM) species decreases relative to that of the paramagnetic (PM) species. Such a variation of the FM/PM ratio with composition and temperature is evidenced from the Moessbauer spectra of La{sub 0.5}Sr{sub 0.5}CoO{sub 3} as well. The variation of the FM/PM ratio with and size-disorder, as well as a local-probe study using {sup 59}Co Nuclear magnetic resonance spectroscopy suggest that electronic phase separation is an inherent feature of the Ln {sub 0.5}Sr{sub 0.5}CoO{sub 3} type cobaltates, with the nature of the different magnetic species in the phase-separated system varying with and size disorder. - Graphicalmore » abstract: Variation of (a) T {sub c} and (b) FC magnetization at 1000 Oe with at 120 K in Ln {sub 0.5}Sr{sub 0.5}CoO{sub 3} and Dy{sub 0.34}Nd{sub 0.16}Sr{sub 0.40}Ca{sub 0.10}CoO{sub 3}.« less

Singer based classification of song data is important in the applications like, organized archival and indexing of music data, music retrieval. In a song, singing voice is mixed with accompanying instrument signal. To extract the vocal characteristics of the singer, the effect of non-voiced part is to be minimized. In this work a simple methodology is proposed to remove the non-voiced segments and to reduce the impression of instruments from the voice-dominating signal. To extract the vocal signature, proposed features extract the variation pattern of zero crossing rate and short term energy. In broad sense, the features try to capture the range of pitch and energy over which a singer mostly operates. This is motivated by the way a human being tries to identify a singer. Finally, singer based classification is done using multi-layer perceptron network. Experiment is carried out with artist20 dataset and 63% classification accuracy is achieved. Comparison with reported works on the same dataset shows that the performance of the proposed simple methodology is better than the majority and very close to others.

We present a detailed investigation of the magnetic and superconducting properties of ${\mathrm{Ca}}_{1\ensuremath{-}x}{\mathrm{Na}}_{x}{\mathrm{Fe}}_{2}{\mathrm{As}}_{2}$ single crystals with $x=0.00$, 0.35, 0.50, and 0.67 by means of the local probe techniques M\"ossbauer spectroscopy and muon spin relaxation experiments. With increasing Na-substitution level, the magnetic order parameter is suppressed. For $x=0.50$ we find a microscopic coexistence of magnetic and superconducting phases accompanied by a reduction of the magnetic order parameter below the superconducting transition temperature ${T}_{c}$. A systematic comparison with other 122 pnictides reveals a square-root correlation between the reduction of the magnetic order parameter and the ratio of the transition temperatures ${T}_{c}/{T}_{N}$, which can be understood in the framework of a Landau theory. In the optimally doped sample with ${T}_{c}\ensuremath{\approx}34$ K, diluted magnetism is found and the temperature dependence of the penetration depth and superfluid density are obtained, proving the presence of two superconducting $s$-wave gaps.

A simple protocol is developed for the synthesis of oxazoles from 1,2-diketones and primary amines via Ag(I)-mediated Cα(sp3)—H activation of the amines followed by oxidative C—O cross coupling and cyclization.

A new silver(I)-mediated Cα(sp3)–H bond functionalization of primary amines and subsequent oxidative C–N cross-coupling reaction has been demonstrated. This protocol provides a simple, highly efficient, and straightforward approach to form significantly diverse 1,2,4,5-tetrasubstituted imidazoles. In this course of the reaction, a stoichiometric amount of Ag2CO3 was employed. Upon completion of reaction, the silver species was successfully recycled and reused without any loss of activity. Good to excellent yields of the products were readily achieved by using this selective oxidative C–N coupling, which was promoted by a crucial silver(I) salt.

Using a combination of muon-spin relaxation $(\ensuremath{\mu}\mathrm{SR})$, inelastic neutron scattering (INS), and nuclear magnetic resonance (NMR), we investigated the novel iron-based superconductor with a triclinic crystal structure ${({\mathrm{CaFe}}_{1\ensuremath{-}x}{\mathrm{Pt}}_{x}\mathrm{As})}_{10}{\mathrm{Pt}}_{3}{\mathrm{As}}_{8}$ (${T}_{\text{c}}=13$ K), containing platinum-arsenide intermediary layers. The temperature dependence of the superfluid density obtained from the $\ensuremath{\mu}\mathrm{SR}$ relaxation-rate measurements indicates the presence of two superconducting gaps, ${\ensuremath{\Delta}}_{\text{1}}\ensuremath{\gg}{\ensuremath{\Delta}}_{\text{2}}$. According to our INS measurements, commensurate spin fluctuations are centered at the $(\ensuremath{\pi},\phantom{\rule{0.16em}{0ex}}0)$ wave vector, like in most other iron arsenides. Their intensity remains unchanged across ${T}_{\text{c}}$, indicating the absence of a spin resonance typical for many Fe-based superconductors. Instead, we observed a peak in the spin-excitation spectrum around $\ensuremath{\hbar}{\ensuremath{\omega}}_{0}=7$ meV at the same wave vector, which persists above ${T}_{\text{c}}$ and is characterized by the ratio $\ensuremath{\hbar}{\ensuremath{\omega}}_{0}/{k}_{\text{B}}{T}_{\text{c}}\ensuremath{\approx}6.2$, which is significantly higher than typical values for the magnetic resonant modes in iron pnictides $(\ensuremath{\sim}4.3)$. The temperature dependence of magnetic intensity at 7 meV revealed an anomaly around ${T}^{*}=45$ K related to the disappearance of this new mode. A suppression of the spin-lattice relaxation rate, $1/{T}_{1}T$, observed by NMR immediately below ${T}^{*}$ without any notable subsequent anomaly at ${T}_{\mathrm{c}}$, indicates that ${T}^{*}$ could mark the onset of a pseudogap in ${({\mathrm{CaFe}}_{1\ensuremath{-}x}{\mathrm{Pt}}_{x}\mathrm{As})}_{10}{\mathrm{Pt}}_{3}{\mathrm{As}}_{8}$, which is likely associated with the emergence of preformed Cooper pairs.

(Li0.795Fe0.205)OH (Fe0.915Li0.085)Se is hydrothermally prepared from a mixture of iron metal, selenourea, and LiOH in H2O (autoclave, 150 °C, 8 d) and characterized by powder and single crystal XRD, SEM, 57Fe-Moessbauer spectroscopy, and DFT electronic structure calculations.

The ferromagnetic (FM) quantum critical system YbNi4P2 has been investigated by means of 31P-NMR. This is a newly discovered heavy fermion system which shows a FM transition at a very low TC = 170 mK. The present reported result is the extension of our previous work published in Ref. 11. 31P NMR results suggest the validity of the Korringa law in the presence of strong FM correlations. 31P NMR spectra have shown the anisotropic nature. The local magnetization derived from our NMR spectra is presented as a function of field at selected temperatures. The obtained spin-lattice relaxation rate 31(1/T1T) follows a weak power-law as T−0.75 in a wide field range down to T = 1.8 K. Possible scenarios for this unusual power-law behavior are discussed. Additionally, 31(1/T1T) is nicely scaled with the observed (C/T)2 ∼ T−0.8 power law in the temperature range 1.8–10 K within the framework of renormalized Landau Fermi Liquid theory.

Tall chimneys play pivotal role in proper functioning of many industrial facilities like thermal, nuclear power plants, petrochemical and steel industry. Because of the non-uniformity of the diameter along the height of the chimney and also the variation of dead weights at different levels, seismic analyses of chimney have become critical and the design values need to be recommended with caution. In this paper, a RCC multi-flue chimney of 275 m height has been considered for study. Design forces in the chimney were obtained in accordance with the stipulated recommendations of IS 1893 (Part 4) 2005 for based on equivalent static lateral force method. Then dynamic response spectrum modal analyses were carried out for calculating the seismic forces developed in the chimney. The results from the response spectrum method were compared with the values obtained from the codal procedures for different base conditions viz. fixed base, circular raft resting on soil and annular raft resting on piles. Next, spectrum compatible time history for the particular project site has been considered and detailed dynamic analyses using time history were carried out for the chimney structure. The variations in the design force values as compared to the simplified methods are discussed and the importance of the proper dynamic analyses in designing of multi-flue RCC chimney is highlighted.

We report detailed $^{75}\mathrm{As}$ nuclear quadrupole resonance investigations of the locally noncentrosymmetric superconductor SrPtAs. The spin-lattice relaxation studies prove weakly coupled multigap superconductivity. A retardation of the decay in $1/{T}_{1}T$ evidences a nodeless (fully gapped) superconducting state on the complex multipocket Fermi surface, which is consistent with an anisotropic $s$-wave order parameter and with proposed unconventional $f$-wave and chiral $d$-wave symmetries. A quantitative analysis of these models favors the unconventional $f$-wave state.

We present a detailed local probe study of the magnetic order in the oxychalcogenide La2O2Fe2OSe2 utilizing 57Fe Moessbauer, 139La NMR, and muon spin relaxation spectroscopy. This system can be regarded as an insulating reference system of the Fe arsenide and chalcogenide superconductors. From the combination of the local probe techniques we identify a non-collinear magnetic structure similar to Sr2F2Fe2OS2. The analysis of the magnetic order parameter yields an ordering temperature TN = 90.1 K and a critical exponent of beta = 0.133, which is close to the 2D Ising universality class as reported in the related oxychalcogenide family.

N-substituted-2-pyridone derivatives have many pharmaceutical properties. In our research, we have developed an efficient, green, and multicomponent protocol to synthesize such new fused N-substituted-2-pyridone derivatives. Optimum reaction condition was obtained by employing l -proline as an organocatalyst in aqueous SDS solution at 100 °C. Various 1,3-diketones, including indane 1,3-dione with a range of aromatic and aliphatic amines were utilized to synthesize fused 2-pyridone derivatives. The isolation of a reaction intermediate confirmed our proposed mechanism. Water as a reaction medium improved the scope of the reaction methodology to a large extent.

Superconducting [(Li1-x Fex )OH](Fe1-y Liy )Se (x≈0.2, y≈0.08) was synthesized by hydrothermal methods and characterized by single-crystal and powder X-ray diffraction. The structure contains alternating layers of anti-PbO type (Fe1-y Liy )Se and (Li1-x Fex )OH. Electrical resistivity and magnetic susceptibility measurements reveal superconductivity at 43 K. An anomaly in the diamagnetic shielding indicates ferromagnetic ordering near 10 K while superconductivity is retained. The ferromagnetism is from the iron atoms in the (Li1-x Fex )OH layer. Isothermal magnetization measurements confirm the superposition of ferromagnetic and superconducting hysteresis. The internal ferromagnetic field is larger than the lower, but smaller than the upper critical field of the superconductor. The formation of a spontaneous vortex phase where both orders coexist is supported by (57) Fe-Mössbauer spectra, (7) Li-NMR spectra, and μSR experiments.

We present our results of a local probe study on EuFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ single crystals with $x$=0.13, 0.19 and 0.28 by means of muon spin rotation and ${}^{57}$Fe M\"ossbauer spectroscopy. We focus our discussion on the sample with $x$=0.19 viz. at the optimal substitution level, where bulk superconductivity ($T_{\text{SC}}=28$ K) sets in above static europium order ($T^{\text{Eu}}=20$K) but well below the onset of the iron antiferromagnetic (AFM) transition ($\sim$100 K). We find enhanced spin dynamics in the Fe sublattice closely above $T_{\text{SC}}$ and propose that these are related to enhanced Eu fluctuations due to the evident coupling of both sublattices observed in our experiments., Comment: Contribution to the 13th International Conference on Muon Spin Rotation, Relaxation and Resonance (MuSR2014)

The new Ge-based skutterudites MPt 4 Ge 12 are investigated by 195 Pt NMR . They form with M = Ba, Sr, La, Ce, Pr, Nd, Sm, Eu, Th and U and in contrast to some pnictide skutterudites they remain metallic independent of the filler ion. Here we show that, consistent with the Korringa theory, the residual shift 195 K(T → 0) scales with the density of states N(E F ) and with the electronic specific heat coefficient γ. For the heavy filler ions La and Th an unusual 195 K(T) dependence was found which might be associated to the effect of dynamic disorder (rattling). For paramagnetic CePt 4 Ge 12 a Curie-Weiss-like behaviour in both the shift 195 K(T) and the bulk susceptibility χ(T) confirms the Ce 3+ -4f 1 -state at high temperatures. At low temperatures 195 K(T) passes through a maximum at around 60 K and saturates below 10 K. This is interpreted being due to an unstable Ce valence, like, e.g. in CeSn 3 . Further evidence comes from the spin-lattice relaxation where 195 (1/T 1 ) starts to deviate from its low-temperature linear Korringa-type of behaviour at around 60 K. We discuss our findings in the context of a dense Kondo system with valence fluctuations. For the van-Vleck para-magnet SmPt 4 Ge1 2 at low-temperatures, surprisingly, the shift is of the same order as for CePt 4 Ge 12 . It also passes through a maximum but at much lower temperatures (~6 K).

27Al Knight shift (K) in grain aligned PrNi 2 Al 5 has been measured, in the temperature range 3.5–320 K, for two crystallographic non-equivalent Al sites. K becomes independent of temperature below 25 K in each case. χ f ( T ) for a Pr 3 + ion in the orthorhombic crystal-field has been calculated to estimate the crystalline-electric-field (CEF) coefficients using K. The over-all crystal-field splitting ( Δ ) is 660 K and CEF energy from the ground state to the first excited state is 45 K .

We report bulk superconductivity (SC) in Ca$_3$Ir$_4$Sn$_{13}$ by means of $^{119}$Sn nuclear magnetic resonance (NMR) experiments. Two classical signatures of BCS superconductivity in spin-lattice relaxation rate ($1/T_1$), namely the Hebel-Slichter coherence peak just below the $T_c$ and the exponential decay in the superconducting phase, are evident. The noticeable decrease of $^{119}$Sn Knight shift below $T_c$ indicates spin-singlet superconductivity. The temperature dependence of the spin-lattice relaxation rate ($1/T_1$) is convincingly described by the multigap isotropic superconducting gap. Present NMR experiments do not witness any sign of enhanced spin fluctuations in the normal state.

Detailed $^{195}$Pt- and $^{171}$Yb nuclear magnetic resonance (NMR) studies on the heterogeneous mixed valence system YbPtGe$_2$ are reported. The temperature dependence of the $^{195}$Pt-NMR shift $^{195}K(T)$ indicates the opening of an unusual magnetic gap below 200\,K. $^{195}K(T)$ was analyzed by a thermal activation model which yields an isotropic gap $\Delta/k_B \approx 200$\,K. In contrast, the spin-lattice relaxation rate $^{195}$($1/T_1$) does not provide evidence for the gap. Therefore, an intermediate-valence picture is proposed while a Kondo-insulator scenario can be excluded. Moreover, $^{195}$($1/T_1$) follows a simple metallic behavior, similar to the reference compound YPtGe$_2$. A well resolved NMR line with small shift is assigned to divalent $^{171}$Yb. This finding supports the proposed model with two sub-sets of Yb species (di- and trivalent) located on the Yb2 and Yb1 site of the YbPtGe$_2$ lattice.

TiO2 nanoparticles efficiently catalyze the three component condensation of aromatic aldehydes, primary amines and acetylenedicarboxylate under admicellar conditions to yield 3-hydroxy-2-pyrrolidinones in good yields.

Lands around the coasts are often reclaimed, contain fill materials/loose fills and therefore potentially liquefiable under moderate to strong shaking. Collapse and/or severe damage to pile-supported structures are still observed in liquefiable soils after most major earthquakes e.g. the 2011 Japan earthquake, 2010 Chile earthquake, the 2008 Wenchuan earthquake, the 2004 Sumatra earthquake, the 2001 Bhuj earthquake, the 1995 Kobe earthquake. Poor performance of pile foundations remains a great concern to the earthquake engineering community. A comprehensive overview of pile damages observed in the recent earthquakes is presented in this paper. This paper also critically reviews all the established pile failure theories. Deficiencies of the existing pile failure theories are highlighted. Various analyses procedures for piles in liquefiable soils are discussed.

We aimed to analyse the pregnancy outcome of women with extrahepatic portal vein obstruction.This was a retrospective observational analysis conducted at the Institute of Postgraduate Medical Education and Research, Kolkata, India, between January 2007 and September 2009. A total of 41 pregnancies in 24 women were evaluated.All women conceived spontaneously (maternal age 20-35 years). 17 women had moderate-to-severe anaemia, and five women had pancytopenia. Variceal bleeding occurred in ten women during pregnancy, which was managed successfully with endoscopic sclerotherapy in eight women and endoscopic variceal ligation in two women. Preterm labour (14.63%), postpartum haemorrhage (7.31%), abortion (4.87%) and pregnancy-induced hypertension (4.87%) were observed in the 41 pregnancies. There were 39 live births and almost all mothers delivered vaginally, except for four who underwent Caesarean section for obstetric indications. Prematurity (15.38%), low birth weight (10.25%), admission to the neonatal intensive care unit (12.82%), stillbirth (2.56%) and neonatal death (2.56%) were noted in the newborns.Variceal bleeding during pregnancy coincided with unfavourable outcomes. Although endoscopic obliteration of varices is a safe and effective method for antenatal management of varices in women, prenatal obliteration results in less morbidity. On rare occasions, obliterated varices can bleed in subsequent pregnancies. Therefore, preconception evaluation of the state of varices prior to each pregnancy and their ligation are important aspects of counselling. A successful foetomaternal outcome is achievable with multidisciplinary backup in a tertiary care centre.

We present a complete characterization of the ferromagnetic system CeIr${}_{2}$B${}_{2}$ using powder x-ray diffraction (XRD), magnetic susceptibility $\ensuremath{\chi}(T)$, isothermal magnetization $M(H)$, specific heat $C(T)$, electrical resistivity $\ensuremath{\rho}(T,H)$, and thermoelectric power $S(T)$ measurements. Furthermore, ${}^{11}$B NMR study was performed to probe the magnetism on a microscopic scale. Rietveld refinement of powder XRD data confirms that CeIr${}_{2}$B${}_{2}$ crystallizes in CaRh${}_{2}$B${}_{2}$-type orthorhombic structure (space group fddd). The $\ensuremath{\chi}(T)$, $C(T)$, and $\ensuremath{\rho}$(T) data confirm bulk ferromagnetic ordering with ${T}_{c}=5.1$ K. Ce ions in CeIr${}_{2}$B${}_{2}$ are in a stable trivalent state. Our low-temperature $C(T)$ data measured down to 0.4 K yield a Sommerfeld coefficient $\ensuremath{\gamma}$ = 73(4) mJ/mol K${}^{2}$, which is much smaller than the previously reported value of $\ensuremath{\gamma}$ = 180 mJ/mol K${}^{2}$ deduced from the specific heat measurement down to 2.5 K. For LaIr${}_{2}$B${}_{2}$, $\ensuremath{\gamma}$ = 6(1) mJ/mol K${}^{2}$, which implies the density of states at the Fermi level $\mathcal{D}({E}_{F})=2.54$ states/(eV f.u.) for both spin directions. The renormalization factor for quasiparticle density of states and hence for quasiparticle mass due to $4\phantom{\rule{-0.16em}{0ex}}f$ correlations in CeIr${}_{2}$B${}_{2}$ is $\ensuremath{\approx}$12. The Kondo temperature ${T}_{\mathrm{K}}\ensuremath{\sim}4$ K is estimated from the jump in specific heat of CeIr${}_{2}$B${}_{2}$ at ${T}_{c}$. Both $C(T)$ and $\ensuremath{\rho}(T)$ data exhibit a gapped-magnon behavior in the magnetically ordered state with an energy gap ${E}_{g}\ensuremath{\sim}3.5$ K. The $\ensuremath{\rho}$ data as a function of magnetic field $H$ indicate a large negative magnetoresistance (MR) which is highest for $T=5$ K. While at 5 K the negative MR keeps on increasing up to 10 T, at 2 K an upturn is observed near $H=3.5$ T. On the other hand, the thermoelectric power data have small absolute values ($S\ensuremath{\sim}7\ensuremath{\mu}$V/K), indicating a weak Kondo interaction. A shoulder in $S(T)$ at about 30 K, followed by a minimum at $\ensuremath{\sim}$10 K, is attributed to crystal electric field effects and the onset of magnetic ordering. ${}^{11}$B NMR line broadening provides strong evidence of ferromagnetic correlations below 40 K.

We studied the heavy-fermion system YbNi${}_{4}$P${}_{2}$, which presents strong ferromagnetic correlations, using the local ${}^{31}\phantom{\rule{-0.16em}{0ex}}$P NMR probe over a wide field (0.2--8.6 T) and temperature (1.8--200 K) range. The ${}^{31}\phantom{\rule{-0.16em}{0ex}}$P NMR Knight shift provides the static spin susceptibility which tracks the bulk susceptibility whereas the spin-lattice relaxation rate ${}^{31}(1/{T}_{1}$) provides information about the fluctuations of the Yb $4f$ moment. The Korringa law is valid over a wide range of temperature and field. The Korringa product ${}^{31}(1/{T}_{1}T{K}^{2}{S}_{0})\ensuremath{\ll}1$ gives evidence for the presence of strong ferromagnetic correlations. A ${}^{31}(1/{T}_{1}T)\ensuremath{\sim}{T}^{\ensuremath{-}3/4}$ behavior was found over two decades in temperature.

With the advent of image and video representation of visual scenes in digital computer, subsequent necessity of vision-substitution representation of a given image is felt. The medium for non-visual representation of an image is chosen to be sound due to well developed auditory sensing ability of human beings and wide availability of cheap audio hardware. Visionary information of an image can be conveyed to blind and partially sighted persons through auditory representation of the image within some of the known limitations of human hearing system. The research regarding image sonification has mostly evolved through last three decades. The paper also discusses in brief about the reverse mapping, termed as sound visualization. This survey approaches to summarize the methodologies and issues of the implemented and unimplemented experimental systems developed for subjective sonification of image scenes and let researchers accumulate knowledge about the previous direction of researches in this domain.

We report bulk superconductivity (SC) in Eu$_{0.2}$Sr$_{0.8}$(Fe$_{0.86}$Co$_{0.14}$)$_{2}$As$_{2}$ single crystals by means of electrical resistivity, magnetic susceptibility, and specific heat measurements with $T$$_{\mathrm{c}}$ $\simeq$ 20 K with an antiferromagnetic (AFM) ordering of Eu$^{2+}$ moments at $T$$_{\mathrm{N}}$ $\simeq$ 2.0 K in zero field. $^{75}$As NMR experiments have been performed in the two external field directions (H$\|ab$) and (H$\|c$). $^{75}$As-NMR spectra are analyzed in terms of first order quadrupolar interaction. Spin-lattice relaxation rates (1/$T_{1}$) follow a $T^{3}$ law in the temperature range 4.2-15 K. There is no signature of Hebel-Slichter coherence peak just below the SC transition indicating a non s-wave or s$_{\pm}$ type of superconductivity. The increase of 1/$T_{1}T$ with lowering the temperature in the range 160-18 K following $\frac{C}{T+\theta}$ law reflecting 2D AFM spin fluctuations.

Physical review / B 86, 235138 (2012). doi:10.1103/PhysRevB.86.235138, Published by APS, College Park, Md.

We report (11)B and (195)Pt NMR Knight shift K and spin-lattice relaxation rate 1/T(1) in CePt(2)B(2)C in the range 4-315 K. The quadrupolar coupling constant, ν(Q) for boron nuclei is 790 ± 10 kHz. The change of hyperfine field, H(hf), is observed below 30 K in the K versus susceptibility, χ, plot. The calculated value of H(hf) at the (11)B ((195)Pt) is 0.156 (6.86) kOe/μ(B) in the range 30-300 K and ∼0 (0.22) kOe/μ(B) below 30 K. The 1/T(1) versus T curve shows some exotic behavior. The Ce 4f spin contribution to the nuclear relaxation rate (1/T(1f)) in each case is obtained by subtracting the T(1K)(-1) estimated from its La analog, i.e. LaPt(2)B(2)C. In the case of (11)B resonance, in the temperature range of 300-100 K, (1/T(1f)) is independent of T, suggesting a Curie-Weiss behavior of the imaginary part of the dynamic susceptibility. It then shows a slow but continuous increment in the range 100-70 K, indicating a signature of the development of short-range magnetic correlation among the Ce 4f spins. Below 70 K, this enhancement of 1/T(1f) is completely suppressed and it decreases sharply, indicating a suppression of the effect of magnetic correlation, due to the dominance of the Kondo effect over the RKKY interaction. 1/T(1f), follows ∼T(α), with an exponent α∼0.7 in the range 4-30 K for (195)Pt and in the range 8-30 K for (11)B resonance. This is a characteristics of a non-Fermi-liquid like behavior. However, in the case of (11)B, there is again a clear change in the slope of the 1/T(1f) versus T curve below 8 K, with the value of α = 1.0, as if the behavior of the conduction electrons approaches towards a Fermi liquid, when probed near the (11)B site.

We have investigated the ground-state properties of polycrystalline CeCoAsO by means of magnetization, specific heat, and solid-state NMR. Susceptibility and specific-heat measurements suggest a ferromagnetic order at about, ${T}_{C}=75\text{ }\text{K}$. No further transitions are found down to 0.5 K. At 6.5 K a complex Schottky type of anomaly shows up in the specific-heat results. The interplay between $\text{Ce}\text{ }4f$ and $\text{Co}\text{ }3d$ magnetism being responsible for that anomaly is discussed. Furthermore $^{75}\text{A}\text{s}$-NMR investigations have been performed to probe the magnetism on a microscopic scale. As-NMR spectra are analyzed in terms of first and second-order quadrupolar interaction. The anisotropic shift component ${K}_{\text{ab}}$ and ${K}_{\text{c}}$ could be derived from the $^{75}\text{A}\text{s}$ powder spectra. Towards lower temperature a strong shift anisotropy was found. Nonetheless ${K}_{\text{iso}}$ tracks the bulk susceptibility down to $T=50\text{ }\text{K}$ very well. Furthermore the presence of weak correlations among the Ce ions in the ferromagnetic state is discussed. The observed increase in $C/T$ towards lower temperatures supports this interpretation.

Background Innovative but costly small-bowel enteroscopies, capsule endoscopy (CE), and double-balloon endoscopy (DBE) have revolutionized the management of obscure GI bleeding (OGIB). Objective To measure the impact of these procedures on outcomes of OGIB in a resource-poor setting. Design Prospective cohort study and comparison with a historical cohort. Setting Tertiary-care center in India. Patients Fifty-three patients with OGIB, diagnosed by American Gastroenterological Association criteria. Interventions DBE and/or CE were performed. Patients were then offered specific treatment and/or hematinics. Main Outcome Measurements The etiology of OGIB in a tropical country and yield of DBE and/or CE. The number of investigations required, follow-up hemoglobin, rebleeds, and interventions/transfusions needed were compared between the present and historical cohort. Results Mean age was 46.4 years with hemoglobin (mean ± standard deviation) of 8.3 ± 2.3 g/dL at evaluation. OGIB was overt in 33 and occult in 20. They underwent 173 investigations before referral. DBE and/or CE localized the source of bleeding in 43 (yield 81%). Angiodysplasias, tumors, Crohn's disease, intestinal tuberculosis, and hookworm infestation were predominant etiologies. Compared with the historical cohort, DBE and/or CE have reduced the number of investigations per patient, increased the yield of mid intestinal source of OGIB, and reduced the number of surgeries, especially emergency laparotomies. There was no significant alteration in the overall yield, mortality, and rebleeding rates. Limitation Small cohort without economic analysis. Conclusions The demographic profile and etiological spectrum of OGIB in the tropics is different. DBE and/or CE have made a favorable impact on management.

NMR studies of $^{51}\mathrm{V}$ in $\mathrm{Sr}{\mathrm{Ni}}_{2}{\mathrm{V}}_{2}{\mathrm{O}}_{8}$, a $S=1$ quasi-one-dimensional antiferromagnet, reveal no magnetic long-range order down to $3.75\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, in contradiction to the prediction from the inelastic neutron scattering data. The temperature dependence of the NMR frequency shift leads to spin gap, $\ensuremath{\Delta}\ensuremath{\sim}25\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, in the low energy excitations. The spin-lattice relaxation rates suggest a temperature dependence of a spin gap with $\ensuremath{\Delta}\ensuremath{\sim}38\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ in $80KlTl15K$ and are dominated by the spin diffusion term below $10\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. Thus the ground state of $\mathrm{Sr}{\mathrm{Ni}}_{2}{\mathrm{V}}_{2}{\mathrm{O}}_{8}$ is more correctly described as a disordered ``spin liquid'' Haldane state as in isomorphous $\mathrm{Pb}{\mathrm{Ni}}_{2}{\mathrm{V}}_{2}{\mathrm{O}}_{8}$.

$^{51}\mathrm{V}$ nuclear magnetic resonance (NMR) studies in polycrystalline sample of ${\mathrm{BaCu}}_{2}{\mathrm{V}}_{2}{\mathrm{O}}_{8}$ reveal the existence of nonzero spin densities, with unequal magnitudes, at the two vanadium sites, viz., ${\mathrm{V}}_{1}$ and ${\mathrm{V}}_{2}$ and hence the participation of ${\mathrm{VO}}_{4}$ tetrahedra to the intrachain and interchain exchange interaction. The behavior of ${K}_{\mathrm{iso}}$ below 200 K provide a clear signature of the reduction of ${\mathrm{Cu}}^{2+}$ spin susceptibility within the chain. Furthermore, there exist unique hyperfine coupling constants for ${\mathrm{V}}_{1}$ and ${\mathrm{V}}_{2}$ sites. This data also confirms the existence of only one spin component and the ground state corresponds to a nonmagnetic spin singlet. The $T$ dependence of ${K}_{\mathrm{iso}}$ above 120 K follows the nature of ${\ensuremath{\chi}}_{\text{spin}}(T)$ proposed by Hatfield for alternating chain model. While below 80 K, it follows the expression for ${\ensuremath{\chi}}_{\mathrm{spin}}$ of a one-dimensional chain with a spin gap $\ensuremath{\Delta}$. From the ${K}_{\mathrm{iso}}$ data we have obtained $\ensuremath{\Delta}=215\ifmmode\pm\else\textpm\fi{}5\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, which is smaller than that determined from the magnetic susceptibility $(\ensuremath{\Delta}=230\phantom{\rule{0.3em}{0ex}}\mathrm{K})$ data. The hyperfine field for ${\mathrm{V}}_{1}$ and ${\mathrm{V}}_{2}$ sites are 24.6 and $14.4\ifmmode\pm\else\textpm\fi{}1.0\phantom{\rule{0.3em}{0ex}}\mathrm{kOe}∕{\ensuremath{\mu}}_{B}$, respectively, with a ratio of 1.7 between them. Thus the exchange path $\mathrm{Cu}\ensuremath{-}\mathrm{O}\ensuremath{-}{\mathrm{V}}_{2}\ensuremath{-}\mathrm{O}\ensuremath{-}\mathrm{Cu}$ in ${\mathrm{BaCu}}_{2}{\mathrm{V}}_{2}{\mathrm{O}}_{8}$ is not negligible. The spin-lattice relaxation time, ${T}_{1}$, for both the sites are identical in the range 300--40 K and vary from 3 ms to 10 s. $1∕{T}_{1}$ follows an activated behavior and provides a gap parameter $\ensuremath{\Delta}=380\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, which is much higher than that obtained from shift data. Moreover, the magnitude of $1∕{T}_{1}T$ decreases more rapidly than that of ${K}_{\mathrm{iso}}$ below 75 K.

We report $^{27}\mathrm{Al}$ NMR studies of ${\mathrm{CeNi}}_{2}{\mathrm{Al}}_{5}$ and ${\mathrm{LaNi}}_{2}{\mathrm{Al}}_{5}$ in $7\phantom{\rule{0.3em}{0ex}}\text{T}$ and in the range $3.5\char21{}300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. ${\mathrm{CeNi}}_{2}{\mathrm{Al}}_{5}$ is dense Kondo compound that orders antiferromagnetically at $2.6\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. For two inequivalent $\mathrm{Al}$ sites for the $\mathrm{Ce}$ compound, the nuclear quadrupolar splitting frequency, ${\ensuremath{\nu}}_{\mathrm{Q}}$ is 0.98 and $2.52\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$, respectively. Knight shifts for both the sites are almost equal in magnitude and follow a linear relation with molar susceptibility in the range $30\char21{}300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The transferred hyperfine coupling constant, ${H}_{\mathrm{hf}}=1.84\phantom{\rule{0.3em}{0ex}}\mathrm{kOe}∕{\ensuremath{\mu}}_{\mathrm{B}}$, is small compared to those in other $\mathrm{Ce}$ compounds. The behavior of $1∕{T}_{1f}$ for the two $\mathrm{Al}$ sites is widely different. For the $\mathrm{Al}(1)$ site, with one nearest-neighbor $\mathrm{Ce}$ ion, the $4f$-electron spin-fluctuation process dominates over the Korringa contribution. In particular, the $\mathrm{Ce}\text{\ensuremath{-}}4f$ spin correlation nearest to $\mathrm{Al}(1)$ starts to develop below $150\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. Finally near $12\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, the fluctuation frequency of the $4f$ spin becomes comparable to the $^{27}\mathrm{Al}$ NMR frequency, resulting in the reduction of $1∕{T}_{1f}$ with further lowering of temperature. For the $\mathrm{Al}(2)$ site, which sits in between two $\mathrm{Ce}$ near neighbors, the relaxation process is dominated by the Korringa contribution in the range $12\char21{}300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. It could, however, sense the effect of $4f$ spin correlations below $12\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The widely different $^{27}\mathrm{Al}$ nuclear relaxation mechanisms for two inequivalent $\mathrm{Al}$ sites in the unit cell of ${\mathrm{CeNi}}_{2}{\mathrm{Al}}_{5}$ indicate that the effect of the spin fluctuation due to the Kondo effect overcomes that due to the Rudderman-Kittel-Kasuya-Yosida interaction for the $\mathrm{Al}(2)$ site in the range $12\text{\char21{}}300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. On the other hand, the behavior of $1∕{T}_{1f}$ for the $\mathrm{Al}(1)$ site resembles that of ${\mathrm{CeAl}}_{2}$.

Background: Benign as well as malignant lesions can present as lymphadenopathy in the head and neck region. Fine-needle aspiration cytology (FNAC) is the least expensive and a well-established method for diagnosing palpable neck nodes. Aim: This was a baseline study done to evaluate the different cytomorphological patterns of metastatic neck nodes, the age and sex distribution of the same, and to study the patterns of lymph node involvement. Materials and Methods: This was a 5-year retrospective study carried out at the Department of Pathology, Regional Institute of Medical Sciences, Imphal, Manipur for the period between September 2005 and August 2010. The FNAC results were reviewed and the morphology of the individual cells and their patterns were studied in detail. All hematolymphoid neoplasms were excluded. Result: A total of 380 cases with metastasis to the head and neck nodes were encountered. Three hundred and twenty-six (90.2%) of the cases were seen in patients above 40 years of age. Males [248 (65.3%)] were affected more than females [132 (34.7%)], with a male-to-female ratio of 1.8:1. Metastatic squamous cell carcinoma [126 (31.3%)] was the most common tumor type. Single-lymph node involvement was noted in 360 (94.7%) cases and cervical lymph nodes were the most frequently involved in 241 (63.4%). Conclusion: An early diagnosis of metastatic neck node can be made by FNAC. Squamous cell carcinoma was the predominant cell type in our study, and undifferentiated carcinoma accounts for a significant proportion. Increasing age and male sex is associated with higher chances of developing metastasis.

An 8-year-old child ingested a metallic screw 3 months prior to admission. At laparotomy, the foreign body was found to be lodged inside the vermiform appendix, and was removed by appendicectomy.

Due to its anticuprate Ti2O layer and its fascinating phase diagram with a large coexistence area of superconductivity and a density wave phase, the new class of titanium based superconductors attracts great scientific interest. In this paper we report μSR investigation on powder samples of Ba1-xNaxTi2Sb2O (x = 0, 0.15, 0.25). Our results exhibit both the presence of a charge density wave and superconductivity in Ba1-xNaxTi2Sb2O. The superconducting order parameter, extracted from a vortex state analysis using the numeric Ginzburg-Landau model, is compatible with a s-wave symmetry. In the universal Uemura classification of superconductors this compound is at the verge of unconventional superconductivity.