Heusler 4.0: Tunable Materials

Heusler compounds are a large family of binary, ternary and quaternary compounds that exhibit a wide range of properties of both fundamental and potential technological interest. The extensive tunability of the Heusler compounds through chemical substitutions and structural motifs makes the family especially interesting. In this article we highlight recent major developments in the field of Heusler compounds and put these in the historical context. The evolution of the Heusler compounds can be described by four major periods of research. In the latest period, Heusler 4.0 has led to the observation of a variety of properties derived from topology that includes: topological metals with Weyl and Dirac points; a variety of non-collinear spin textures including the very recent observation of skyrmions at room temperature; and giant anomalous Hall effects in antiferromagnetic Heuslers with triangular magnetic structures. Here we give a comprehensive overview of these major achievements and set research into Heusler materials within the context of recent emerging trends in condensed matter physics

Pressure induced magnetic and magnetocaloric properties in NiCoMnSb Heusler alloy

The effect of pressure on the magnetic and the magnetocaloric properties around the martensitic transformation temperature in NiCoMnSb Heusler alloy has been studied. The martensitic transition temperature has significantly shifted to higher temperatures with pressure, whereas the trend is opposite with the application of applied magnetic field. The maximum magnetic entropy change around the martensitic transition temperature for Ni45Co5Mn38Sb12 is 41.4 J/kg K at the ambient pressure, whereas it is 33 J/kg K at 8.5 kbar. We find that by adjusting the Co concentration and applying suitable pressure, NiCoMnSb system can be tuned to achieve giant magnetocaloric effect spread over a large temperature span around the room temperature, thereby making it a potential magnetic refrigerant material for applications.Comment: 16 pages, 5 figure

A common spatial mode for intra-seasonal and inter-annual variation and predictability of the Indian summer monsoon

How and to what extent the intra-seasonal oscillations (ISOs) of the Indian summer monsoon influence the seasonal mean and its inter-annual variability is investigated using long records of daily circulation data (1956-1997) and outgoing long wave radiation (OLR) data (1974-1997). The underlying spatial structure of a typical ISO cycle that is invariant from event to event and year to year is brought out. It is shown that the intra-seasonal and interannual variations are governed by a common mode of spatial variability. A higher frequency of occurrence of 'active' ('break') conditions within a monsoon season, therefore, could result in a 'strong' ('weak') summer monsoon. Two-dimensional probability density function estimates of the ISOs show that 'strong' ('weak') monsoon years are indeed associated with higher probability of occurrence of 'active' ('break') conditions. For the first time, these results show that the frequency of chaotic ISO regimes determine the seasonal mean monsoon, thereby setting a limit on monsoon predictability

Potential predictability of the Asian summer monsoon on monthly and seasonal time scales

The potential predictability of the monthly and seasonal means during the Northern Hemisphere summer and winter is studied by estimating the signal-to-noise ratio. Based on 33 years of daily low-level wind observations and 24 years of satellite observations of outgoing long wave radiation, the predictability of the Asian summer monsoon region is contrasted with that over other tropical regions. A method of separating the contributions from slowly varying boundary forcing and internal dynamics (e.g., intraseasonal oscillations) that determine the predictability of the monthly mean tropical climate is proposed. We show that the Indian monsoon climate is only marginally predictable in monthly time scales as the contribution of the boundary forcing in this region is relatively low and that of the internal dynamics is relatively large. It is shown that excluding the Indian monsoon region, the predictable region is larger and predictability is higher in the tropics during northern summer. Even though the boundary forced variance is large during northern winter, the predictable region is smaller as the internal variance is larger and covers a larger region during northern winter (due to stronger intraseasonal activity). Consistent with the estimates of predictability of monthly means, estimates of potential predictability on seasonal time scales also indicate that predictability of seasonal mean Indian monsoon is limited

Studies in Sulphonamides Part VII: Synthesis of 1,3 diary1 2 (substituted sulphonamidobenzeneazo) propane 1, 3 diones and evaluation of their antibacterial properties

Different 1, 3-diarylpropane-1, 3-diones, 1-(P-nitropheny1) 3-phenyI-, p-nitropheny1) 3-(p-methyI-pheny1)- 1,)p-nitropheny1-3-(p-methoxypheny1)-, and 1-(m-nitropheny)-3- (p-methyIpheny1) propane 1, 3-diones have synthesised and coupled with a number a diazotised sulphonamide bases to yield the respective 1,3-diaryI-2-(substituted sulphonamidozeneazo) propane. All these substituted sulphonamidobenzence propane-1,3- diones have been screened in vitro for their antibacterial properties using cup plate agar diffusion method and some of these have been found active

Studies in Sulphonamides Part X

The present paper describes the synthesis of four differently substituted dibenzoylmethanes, viz., 1(m-nitropheny1)-3-(p-chloropheny1)-, 1-(m-notropheny1)-3-(p-bromopheny1)-, 1,3-di(p-methoxypheny1) and 1-(p-ethoxypheny1)-3-pheny1 propane-1,3-diones and study of their coupling reactions with different diazotised sulphonamide bases. The resulting 2-sulphonamidobenzeneazo derivatives were subjected to biological assay in vitro against S. aureus and E. coli and some of these found to posses considerable activity

Studies in Heterocyclic Compounds -Part VIII

Different azo compounds, 1-(m-nitrophenyl)-3-(p-bromophenyl)-and 1-(m-nitrophenyl) 3-(p-chlorophenyl)-2-(substituted sulphonamidobenzeneazo) propane-1,3-dinoes on condensation with hydrazine hydrate (100%), phenylhydrazine, p-nitrophenyllhydrazine and benzoylhydrazine yield the corresponding 1-simple/substituted-3-(m-nitrophenyl)-5-(p-bromo chlorophenyl)-4-(substituted sulphonamidobenzeneazo) pyrazoles. The homogeneity and purity of these was confirmed by TLC and these on screening in vitro against S. aureus and E. coli were found to exhibit antibacterial activity

Performance of Garden Pea Genotypes in Eastern Hills of Nepal

Garden pea (Pisum sativum L) is an important winter legume used as fresh vegetables and other drier food products. Despite of its importance as cash crop in many parts of Nepal, much study on various aspects for enhancing production and productivity has yet to be done. Therefore, to evaluate the production performance different genotypes of garden pea in eastern hills agro-ecological conditions present experiments were carried out consecutively for two years (2015 and 2016) at Agricultural Research Station, Pakhribas. The experiment comprised of 11 different genotypes of garden pea including a check variety Arkel. The production performance was evaluated in a completely randomized block design with three replications. The seeds were sown at 50 × 10 cm spacing during first week of October for two years. The result showed that DGP-05 genotype had earliest 104 days after sowing. The DGP-08 genotype showed 13 which were the maximum numbers of pods per plant (13), while DGP-01 showed 8 numbers of seeds as the maximum per pod. The DGP-03 genotype had the longest pod of 9.78 cm among others. The highest fresh pod yield of 18.14 t/ha was achieved from genotype DGP-09 followed by Arkel with (16.32 t/ha).Journal of Nepal Agricultural Research Council Vol.3 2017: 15-1

Estimate of monthly mean predictability in the tropics form observations

A method of separating the contributions from slowly varying boundary forcing and internal dynamics (e.g. intraseasonal oscillations) that determine the predictability of the monthly mean tropical climate is presented. Based on 33 years of daily low level wind observations and 24 years of satellite observations of outgoing long wave radiation, we show that the Indian monsoon climate is only marginally predictable, as the contribution of the boundary forcing in this region is relatively low and that of the internal dynamics is relatively large. It is also shown that excluding the Indian monsoon region, the predictable region is larger and predictability is higher in the tropics during northern summer. Even though the boundary forced variance is large during northern winter, the predictable region is smaller as the internal variance is larger and covers a larger region during that period (due to stronger intraseasonal activity)

Methionine-functionalized graphene oxide/sodium alginate bio-polymer nanocomposite hydrogel beads: Synthesis, isotherm and kinetic studies for an adsorptive removal of fluoroquinolone antibiotics

This work was supported by Pt. Ravishankar Research Fellowship Scheme, Raipur, Chhattisgarh, India (grant number V.R. No. 3114/4/Fin./Sch.//2018). This work was also supported by national funds through FCT-Fundacao para a Ciencia e a Tecnologia, I.P., under the Scientific Employment Stimulus-Institutional Call (CEECINST/00102/2018) and by the Associate Laboratory for Green Chemistry-LAQV, financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020).In spite of the growing demand for new antibiotics, in the recent years, the occurrence of fluoroquinolone antibiotics (as a curative agent for urinary tract disorders and respiratory problems) in wastewater have drawn immense attention. Traces of antibiotic left-overs are present in the water system, causing noxious impact on human health and ecological environments, being a global concern. Our present work aims at tackling the major challenge of toxicity caused by antibiotics. This study deals with the efficient adsorption of two commonly used fluoroquinolone (FQ) antibiotics, i.e., Ofloxacin (OFX) and Moxifloxacin (MOX) on spherical hydrogel beads generated from methionine‒functionalized graphene oxide/ sodium alginate polymer (abbreviated Met-GO/SA) from aqueous solutions. The composition, morphology and crystal phase of prepared adsorbents were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HR-TEM) and thermogravimetric analysis/differential thermogravimetry (TGA/DTG). Batch adsorption tests are followed to optimize the conditions required for adsorption process. Both functionalized and non-functionalized adsorbents were compared to understand the influence of several experimental parameters, such as, the solution pH, contact time, adsorbent dosage, temperature and initial concentration of OFX and MOX on adsorption. The obtained results indicated that the functionalized adsorbent (Met-GO/SA) showed a better adsorption efficiency when compared to non-functionalized (GO/SA) adsorbent. Further, the Langmuir isotherm was validated as the best fitting model to describe adsorption equilibrium and pseudo second-order-kinetic model fitted well for both types of adsorbate. The maximum adsorption capacities of Met-GO/SA were 4.11 mg/g for MOX and 3.43 mg/g for OFX. Thermodynamic parameters, i.e., ∆G°, ∆H° and ∆S° were also calculated. It was shown that the overall adsorption process was thermodynamically favorable, spontaneous and exothermic in nature. The adsorbents were successfully regenerated up to four cycles with 0.005 M NaCl solutions. Overall, our work showed that the novel Met-GO/SA nanocomposite could better contribute to the removal of MOX and OFX from the liquid media. The gel beads prepared have adequate features, such as simple handling, eco-friendliness and easy recovery. Hence, polymer gel beads are promising candidates as adsorbents for large-scale water remediation.publishersversionpublishe