New open-framework layered tin(II ) phosphates intercalated with amines

Two new Sn(II) phosphate materials, I and II, have been synthesized hydrothermally using 1,3-diaminopropane and 1,3-diamino-2-hydroxypropane as structure-directing organic amines. The solids I and II have layered architectures and are isostructural. The structures consist of vertex sharing trigonal-pyramidal SnO and tetrahedral PO moieties forming infinite layers possessing 4- and 8-membered apertures. The interlamellar space is occupied by the protonated amine molecules which interact with the framework through hydrogen bonding. Crystal data for compound I: [NH(CH)NH]2[SnPO], M=501.9, monoclinic, space group C2/c, a=18.097(1), b=7.889(1), c=9.151(1)Å, β=111.84(1)°, V=1212.6(2)Å, Z=4, R=0.033 and R=0.061 [791 observed reflections with I=2σ(I )]; compound II [NH(CHCHOHCH)NH] 2[SnPO], M=517.9, monoclinic, space group C2/c, a=18.133(1), b=7.858(1), c=9.344(1)Å, β=111.3(1)°, V=1240.5(2)Å, Z=4, R=0.040 and R=0.11 [867 observed reflections with I=2σ(I)]

Unusual dual role of the organic amine in an open-framework structure

The hydrothermal synthesis and single crystal structure determination of a new open-framework zinc phosphate, [NH3(CH2)3NH3]2[NH3(CH2)3NH2]2[Zn12(OH2)2(PO4)10]·H2O, is reported. Crystal data: monoclinic, space group Pn (no. 7), a=13.092(2), b=14.272(2), c=14.220(1) Å, β= 90.3(2)°, V=2656.9(1) Å3, Z=2, M=1927.6, R=0.04. The structure is made up of tetrahedral linkages between ZnO4, ZnO3N and PO4 moieties forming distinct channels. The structure-directing amine is present in two distinct forms, in the free state and as a ligand to zinc, the two species occurring in distinct channels

A SCIENTOMETRIC ANALYSIS OF LITERATURE GROWTH IN ANTHRAX

Anthrax is an infectious disease which occurs regularly in southern Europe. It is also used as a weapon by a number of countries. This study is an attempt to investigate and analyze about the literature output on Anthrax. The aim of the present study was to identify literature growth over the period, literature distribution and authorship pattern. The data was obtained from PubMed using the keywords Anthrax”. It was found that a total of 1,955 published literatures for the period 2011-2018 in the field of Anthrax were contributed by 8,185 unique authors in 11 languages in 694 journals in 12 publication types. Ten and above authorship pattern contributed a higher percentage of literature while comparing with other authorship patterns and the total degree of collaboration was 0.94. First authors from USA have contributed around 44.6% of the total literature. Most of the literatures published in these years have citation count between 1-10. The literature published in the year 2011 have the highest citation counts. “Humans” was the more popular MeSH/keyword

Quantitative analysis of the residual stress and dislocation density distributions around indentations in alumina and zirconia toughened alumina (ZTA) ceramics

This is an Open Access Article. It is published by Elsevier under the Creative Commons Attribution 3.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/Alumina, 10% and 20% ZTA with 1.5mol% yttria stabiliser were subjected to Vickers indentation testing with loads from 1 to 20kg. Cr fluorescence and Raman spectroscopy were applied to the indent centre and around the indentation in order to investigate the origin of the signal, the effect of indentation loads and zirconia phase transformation on the residual stress and plastic deformation in the plastic zone. The results suggested that with very strong laser scattering, the depth resolution of ZTA materials was very poor, which lead to a very significant amount of the signal being collected from the subsurface regions below the plastic zone. It was also found that zirconia phase transformation reduced the compressive residual stress in the alumina matrix within the plastic zone, except at the indentation centre, due to the tensile residual microstress generated by the zirconia phase transformation. In addition, the dislocation density on the indent surface of the ZTA samples was significantly reduced due to the restriction of crack propagation and energy absorption during the phase transformation process. At the indent centre, the zirconia phase transformation was suppressed by the high compressive stress, therefore, no significant difference between alumina and ZTA in terms of their residual stress and dislocation density were observed. Using TEM observation, it was found that the plastic zone microstructure of pure alumina is different from that of ZTA, which is consistent with the Cr fluorescence results

Microwave assisted large scale sintering of multilayer electroceramic devices

The feasibility of employing the microwave methodology for the processing of integrated passive devices (IPDs), nanocrystalline ZnO radials and nano multilayer varistor (MLVs) devices was explored. Methodical microwave sintering experiments were carried out using a multimode, 2.45 GHz microwave applicator. Effect of various experimental parameters such as heating rate, cooling rate, soaking time, sintering temperature etc. on the processing of these device components was investigated in detail. The resultant products were characterized for microstructure, composition and electrical performance. The various stages involved in taking the laboratory research to industrial scale-up production were also examined. The use of microwaves for the processing of MLVs was found to genuinely improve the electrical properties in both small scale (~200 devices/ batch) and large scale (~12000 devices/batch) sintering situations. For a stand alone microwave heating process a back-toback cascading /conveyer belt arrangement is recommended for continuous large scale production. However hybrid heating methodology was found to provide the capability of stacking operations and could be helpful in avoiding the use of ‘casketing’, besides providing the possibility of achieving uniform temperature across a large volume. The technique seems to be attractive in terms of its simplicity, rapidity, economic viability and the superior product performance achieved in all the cases augers well for its general applicability

Imparting gas selective and pressure dependent porosity into a non-porous solid: Via coordination flexibility

Using a simple hard-soft acid-base concept we have deliberately designed gas-specific and pressure dependent porosity into a non-porous solid via coordination flexibility. This creates distinct gate-openings wherein the CO2 molecule opens-up the framework pores by rotating the ligand about the weaker hard-soft bonds (hard-soft gate control). For this, we have studied the CO2 gating behaviour of M(4-PyC)2 (M = Mg, Mn and Cu), which represent metals of varying hardness. A combination of quantum chemical calculations, molecular dynamics and Grand canonical Monte Carlo simulations were performed to examine the gate opening of the isonicotinate ligands in Mg(4-PyC)2. The simulations show that interaction of the CO2 molecules with the isonicotinate ligands at different CO2 loadings can result in pressure-dependent gate opening. Furthermore, the simulated CO2 uptake values calculated using the partially gate-opened structures at different loadings showed good agreement with the experimental uptake values. This provides an effective strategy for designing highly-stable dynamic porous solids employing rigid frameworks

Novel Dishwasher with Thermal Storage and Thermoelectric Heat Recovery

Residential dishwashers typically consume domestic hot water, heat it further with electric resistance heating elements, and drain the soiled heated water before each subsequent water fill. During the final rinse, the water is heated to a temperature of approximately 54.5–57.2°C (130–135°F) to heat the load and promote passive drying after the final drain event. In this work, the energy consumption, water consumption, and drying performance of a conventional dishwasher were measured under test conditions similar to U.S. energy efficiency test standards but with an unsoiled load. These measurements were considered baseline performance metrics. The dishwasher was then experimentally modified to recover heat from the drain water utilizing thermoelectric (TE) heat pump modules and a thermal storage component. The TEs were also used during the drying phase to improve the drying of the load. The novel dishwasher was operated in the laboratory under the same conditions as the baseline unit, and its energy consumption, water consumption, and drying performance were measured. The results demonstrated a 14.5% reduction in energy consumption, with the same amount of water consumption, and improved drying by 60% compared to the baseline

Anomalous Critical Field Dependence of Cr-Nb-Cr Trilayers on Niobium Thickness

198-203Cr-Nb-Cr trilayer thin films were deposited using DC/RF sputtering with Cr layer thickness maintained at 7.5 nm and Nb thickness varying from 30 nm to 229 nm, in order to study the interplay of antiferromagnetism and superconductivity. Various viewpoints have been expressed in the literature with respect to analyzing the anomalous properties that have been identified in superconductor/magnetic thin films. The study of Cr-Nb-Cr thin films were taken up to identify the existence of similar anomalous superconducting properties on account of antiferromagnetic-superconductor interfaces. X-ray reflectivity measurements showed high quality of thin film structure with minimum surface and interface roughness. Transport measurements down to 2K were carried out in the presence of magnetic fields up to 2 T applied perpendicular to the trilayers to deduce Tc. The suppression of Tc due to Cr layer is larger than proximity effect of similar metal films. It could be explained by proximity effect using antiferromagnetic Cr layer. Upper critical field measurements show a distinct non monotonic dependence of upper critical magnetic field and the slope on Nb layer thickness. The analysis due to WHH theory to deduce upper critical fields for the trilayer thin films studied did not match with experimental values. Although studies performed on Cr-Nb-Cr trilayers did not show any anomaly in Tc, it clearly showed a depression of Tc much larger than proximity effect, non monotonic behavior in Bc2(0) and dBc2/dTc behavior with Nb layer thickness

Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing

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