Soft Character Research Articles

Yttrium-iron garnet and yttrium orthoferrite nanocrystals: Hydrothermal synthesis, magnetic property and phase transformation study

In this work, we present a new and fast method to obtain the single phase Y3Fe5O12 (YIG, cubic) and YFeO3 (YIP, orthorhombic) nanocrystals based on hydrothermal technique. The influence of initial Y/Fe mole ratio and calcination temperature on the nature, purity, phase structure, and morphology of the product was investigated by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive (EDX) X-ray spectroscopy, and field emission scanning electron microscopy (FESEM). The results show that the transformation of the as-synthesized YIG from amorphous to orthorhombic and finally to cubic phase occurs with the increase of annealing temperature. On this basis, the pure cubic phase YIG can be obtained by calcination (at 1100 °C) of the precursor which is prepared using the hydrothermal treatment of mole ratio of Y:Fe = 1:1.5 exposure to an ammonia atmosphere. Also, the initial Y/Fe mole ratio of 1:1 and calcination temperature of 1000 °C are the optimal conditions to form single-phase nanocrystalline YIP. Further, vibrating sample magnetometry (VSM) measurements illustrate the average magnetic saturation, coercivity and remanence of 2.73 and 15.00 emu/g, 42.74 and 40.02 Oe, and 1.65 and 4.30 emu/g for YIP and YIG nanocrystals, revealing their soft ferromagnetic character.

Enhanced Soft Character of Crystallographically Textured Mn-Doped Binary 0.675[Pb(Mg1/3Nb2/3)O3]–0.325[PbTiO3] Ceramics

Lead magnesium niobate (PMN)–lead titanate (PT) solid solution with composition 0.675 PMN–0.325PT has been obtained with manganese (Mn) doping in various ratios. The effect of Mn on the electrical properties was examined in detail using dry-pressed samples produced from PMN–PT powders synthesized by a solid-state calcination route. Based on the results, 0.7 mol.% was selected as the optimum Mn doping ratio to enhance the soft properties and figure of merit (FOM). Random and textured PMN–PT plates for use in energy harvesting applications were then prepared by a tape-casting method. Samples were textured using 1 vol.% plate-like barium titanate (BaTiO3, BT) template. The calculated FOM of random samples fabricated by tape-casting increased from 8469 × 10−15 m2/N to 11,273 × 10−15 m2/N with Mn doping, in parallel with observations in dry-pressed samples. The FOM of textured PMN–PT was found to be as high as ∼ 25,999 × 10−15 m2/N and increased to ∼ 31,720 × 10−15 m2/N for textured Mn-doped PMN–PT. The Curie temperature (Tc) of samples obtained by tape-casting was measured to be 160°C. The electromechanical properties of the samples were also studied in detail, and property matrices calculated using resonance methods are reported for all compositions.

New Results on Soft Spectral in Soft Banach Algebra

In this paper, concepts of soft character, soft division algebra, soft ideal, soft maximal ideals are introduced .Soft Spectral Radius Formula are introduced and proved, some properties of Soft gelfand algebra are proved.

Formulation and in vitro evaluation of magnetoliposomes as a potential nanotool in colorectal cancer therapy.

Magnetoliposomes (MLPs) offer many new possibilities in cancer therapy and diagnosis, including the transport of antitumor drugs, hyperthermia treatment, detection using imaging techniques, and even cell migration. However, high biocompatibility and functionality after cell internalization are essential to their successful application. We synthesized maghemite nanoparticles (γ-Fe2O3) by oxidizing magnetite cores (Fe3O4) and coating them with phosphatidylcholine (PC) liposomes, obtained using the thin film hydration method, to generate MLPs. The MLPs were tested in vitro, using human tumor and non-tumor colon cell lines, for cytotoxicity, cell uptake and cellular distribution, and magnetically-induced cell mobility. In addition, blood cells biocompatibility studies were performed. The mean size of the MLPs, with a core of γ-Fe2O3 completely surrounded by PC liposomes, was 90 ± 20 nm, showing a soft magnetic character and a great biocompatibility in all the cell lines assayed including blood cells. Prussian blue staining showed a high MLP cell uptake with maximum internalization at 24 h. TEM analysis showed the MLPs surrounded by the cell membrane and in the cell periphery, suggesting internalization by endocytosis and/or macropinocytosis. Interestingly, the mitochondria presented MLP accumulations, particularly in tumor cells. Finally, MLPs within colon cancer cells were able to induce cell migration when a magnetic field was applied in vitro, indicating the functionality of our nanoformulation. A promising biomedical application of these MLPs is anticipated based on their physical, chemical and biological properties.

Counting and Sizing of Single Vesicles/Liposomes by Electrochemical Events

AbstractThe analysis of single entities in a liquid phase by electrochemical events has received much attention in recent years due to innovations and advances in exciting electrochemical methods as well as precise manufacturing techniques. Vesicles, as a special type of entity, play an important role in biological systems. However, the soft character and complex surface chemistry of vesicles present inherent challenges for single‐vesicle analysis. This minireview mainly focuses on the theory and recent progress of single‐vesicle/liposome analysis based on electrochemical events. Three different analytical principles, namely, pore/channel translocation, microelectrode impact and nanopipette collision, are reviewed and expatiated. Not only the capabilities for size determination, vesicle/liposome counting and the electroactive quantification of the contents within vesicles/liposomes but also the specificities of vesicle/liposome or entity‐pore/electrode interactions reflected in translocation or collision events are discussed in detail. Moreover, the advantages and disadvantages of each method of single‐vesicle analysis are discussed in this minireview.

Magneto Optical Properties and Hyperfine Interactions of Cr3+ Ion Substituted Copper Ferrite Nanoparticles

Spinel CuCrxFe2−xO4 (0.0 ≤ y ≤ 1.0) nanoparticles were fabricated by co-precipitation. X-ray diffraction proved the pureness and cubic crystal assembly of products which have the crystallite sizes varying between 16 and 33 nm. The cubic morphology and expected chemical composition, spectral analyses of all sample were accomplished via Scanning electron microscopy along with Energy Dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy respectively. Magnetic and optical characterization of samples were done via Vibrating sample magnetometer, Mossbauer spectroscopy and Diffuse reflectance spectroscopy. Kubelka–Munk model was applied to UV–Vis data for calculating the optical Eg (band gap) values between minimum 1.20 and maximum 1.80 eV. Mossbauer analysis determined the consequence of Cr3+ substitution on isomer shift and quadrupole splitting of all products etc. The specific magnetization (σ-H) hysteresis curves have finite coercivity (in a range of 35–410 Oe) and retentivity (in a range of 0.33–3.84 emu/g) values and reveal the soft ferrimagnetic nature of spinel CuCryFe2−yO4 nanoparticles (NPs). The estimated saturation magnetization Ms value of 35.17 emu/g is maximum for pristine CuFe2O4 NPs and decreases to minimum value of 1.57 emu/g for CuCr0.4Fe1.6O4 NPs due to Cr3+ ion substitution. The calculated squareness ratios less than 0.5 assign the uniaxial anisotropy for all CuCryFe2−yO4 NPs. The magneto-crystalline anisotropy field (Ha) values less than 10.0 kOe except for the composition of CuCr0.2Fe1.8O4 NPs are other magnetic data to reveal the soft magnetic character of samples.

Reflection of Javanese Characters in Afifah Afra’s Novel Nun Pada Sebuah Cermin

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Correction to: Long- and Mid-Term Variations of the Soft X-ray Flare Character in Solar Cycles

Correction to: Solar Phys We found an important error in the text of our article. On page 6, the second sentence of Section 3.2 “We studied the variations in soft X-ray flare characteristics in more detail by averaging them within the running windows of ± one Carrington rotation with a step of two rotations.” should instead read “We studied the variations in soft X-ray flare characteristics in more detail by averaging them within the running windows of ± 2.5 Carrington rotations with a step of two rotations.” We regret the inconvenience. The online version of the original article can be found at https://doi.org/10.1007/s11207-017-1169-1

Consistent, high-quality two-nucleon potentials up to fifth order of the chiral expansion

We present N N potentials through five orders of chiral effective field theory ranging from leading order (LO) to next-to-next-to-next-to-next-to-leading order (N4LO). The construction may be perceived as consistent in the sense that the same power counting scheme as well as the same cutoff procedures are applied in all orders. Moreover, the long-range parts of these potentials are fixed by the very accurate πN low-energy constants (LECs) as determined in the Roy-Steiner equations analysis by Hoferichter, Ruiz de Elvira and coworkers. In fact, the uncertainties of these LECs are so small that a variation within the errors leads to effects that are essentially negligible, reducing the error budget of predictions considerably. The N N potentials are fit to the world N N data below pion-production threshold of the year of 2016. The potential of the highest order (N4LO) reproduces the world N N data with the outstanding χ2/datum of 1.15, which is the highest precision ever accomplished for any chiral N N potential to date. The N N potentials presented may serve as a solid basis for systematic ab initio calculations of nuclear structure and reactions that allow for a comprehensive error analysis. In particular, the consistent order by order development of the potentials will make possible a reliable determination of the truncation error at each order. Our family of potentials is non-local and, generally, of soft character. This feature is reflected in the fact that the predictions for the triton binding energy (from two-body forces only) converges to about 8.1 MeV at the highest orders. This leaves room for three-nucleon-force contributions of moderate size.

NILAI-NILAI KEARIFAN LOKAL DALAM PANDANGAN HIDUP MASYARAKAT ADAT KAMPUNG KUTA

This study aims to explore that the values of local wisdom based on indigenous people. In addition, to develops the character of civic disposition in Kuta Village and its implementation in the level of schooling. The research methodology uses a qualitative approach with case study method. The data was collected by the study of literature, interview, observation and documentation. The results showed that two part of main data. First of all, the values of the character within the indigenous village of Kuta is reflected in the art, the adage (proverb Sunda ), and outlook of life, which consists of a soft character, orderly, efficiency, and discipline. Moreover, mutual love, mutual maintain, teach each other, sincere, obedient or submissive, visionary (thinking ahead), responsible, dedicated, loyalty, sympathy, empathy, compassion, tolerance, sacrifice, devotion, faith and piety, simple, humble, appreciative health, thoughtful, and constructive thinking. Secondly, the implementation of the values of local wisdom in the level of schooling can be through the subject of Civic education, integration in every subject, habituation (habit) of the school and in extra-curricular integration.

Proposal of Gravity Offset Type A Biped Walking Soft Robot Using Character Balloon

Proposal of Gravity Offset Type A Biped Walking Soft Robot Using Character Balloon

Do Capacitance Measurements Reveal Light-Induced Bulk Dielectric Changes in Photovoltaic Perovskites?

Several studies have identified complex interactions between photogenerated carriers and the crystal lattice in perovskite materials for photovoltaics, which are regarded to have an inherently soft character. Light is known to induce phase segregation in mixed halide perovskites, enhance piezoelectricity, and change dipole moments of the unit cell. Therefore, it is appealing to consider photogenerated variations in the bulk polarizability and dielectric properties. Light-induced bulk polarization changes should be observable by capacitance measurements, preferentially at intermediate frequencies where the geometrical capacitance dominates. However, capacitance spectra are influenced by several capacitive and resistive mechanisms, which are also modulated by light. Capacitances may arise from dielectric bulk polarization, space-charge depletion zones, chemical electronic bulk storage, and interfacial accumulation mechanisms. This variety of capacitive mechanisms may induce wrong interpretations and produce...

Effect of rare-earth substitution on the electrical properties and Raman spectroscopy of BCTZ ceramics

A-site deficient rare-earth (Nd, Gd, and Y) doped (Ba0.99Ca0.01)(Zr0.2Ti0.8)O3 ceramics (noted BCTZ) were obtained by the conventional solid-state reaction method. X-ray powder diffraction experiments combined with first-order Raman scattering analysis were performed to provide detailed description of the structures with different ferroelectric/non-ferroelectric phases. Raman spectra investigations give evidence of compositional disorder as well as a significant change of polar order with the incorporation of rare-earth ions on the A-site of BCTZ lattice. The dielectric and ferroelectric properties of the (Ba1-xLn2x/3)0.99Ca0.01)(Zr0.2Ti0.8)O3 ceramics (x = 0 and x = 0.015, Ln = Nd, Gd and Y) were thoroughly investigated as a function of frequency and temperature.This work highlights and demonstrates that the diffuseness of the phase transition increases and that the relaxor behavior is intensifies with rare-earth substitution. Moreover, the transition temperature is remarkably shifted to lower temperature for doped BCTZ ceramics. In the low temperature region, slim ferroelectric hysteresis loops with a low coercive field were observed for all compositions emphasizing their soft character.

Cation-Exchanged Zeolitic Chalcogenides for CO2 Adsorption

We report here the intrinsic advantages of a special family of porous chalcogenides for CO2 adsorption in terms of high selectivity of CO2/N2, large uptake capacity, and robust structure due to their first-ever unique integration of the chalcogen-soft surface, high porosity, all-inorganic crystalline framework, and the tunable charge-to-volume ratio of exchangeable cations. Although tuning the CO2 adsorption properties via the type of exchangeable cations has been well-studied in oxides and MOFs, little is known about the effects of inorganic exchangeable cations in porous chalcogenides, in part because ion exchange in chalcogenides can be very sluggish and incomplete due to their soft character. We have demonstrated that, through a methodological change to progressively tune the host-guest interactions, both facile and nearly complete ion exchange can be accomplished. Herein, a series of cation-exchanged zeolitic chalcogenides (denoted as M@RWY) were studied for the first time for CO2 adsorption. Samples were prepared through a sequential ion-exchange strategy, and Cs+-, Rb+-, and K+-exchanged samples demonstrated excellent CO2 adsorption performance. Particularly, K@RWY has the superior CO2/N2 selectivity with the N2 adsorption even undetected at either 298 or 273 K. It also has the large uptake of 6.3 mmol/g (141 cm3/g) at 273 K and 1 atm with an isosteric heat of 35-41 kJ mol-1, the best among known porous chalcogenides. Moreover, it permits a facile regeneration and exhibits an excellent recyclability, as shown by the multicycling adsorption experiments. Notably, K@RWY also demonstrates a strong tolerance toward water.

Mapping of magnetic and mechanical properties of Fe-W alloys electrodeposited from Fe(III)-based glycolate-citrate bath

Electrodeposition of Fe-W coatings has been carried out from an environmentally friendly Fe(III)-based glycolate-citrate bath. Samples with tungsten content from 6 to 25at.% were electrodeposited in a controlled way by changing electrodeposition parameters: current density, pH, and temperature. X-ray diffraction analysis showed that the structure of Fe-W coatings transforms from nanocrystalline to amorphous-like as the W content increases and the crystallite size reduces below 10nm. However, the peculiarities of the structural transitions are linked not only with the W content. Deposition temperature plays a crucial role, due to the different activation energy of crystallization. Following the direct Hall–Petch relation, a maximum hardness of ~10GPa was found for the alloy with the highest W content, making it comparable to that of electrolytic chromium. The Fe2W intermetallic compound forms at higher W concentration as proven by Mössbauer spectroscopy, and contributes to the increased hardness of these alloys. The alloys retain a soft magnetic character within a wide compositional range, although increasing the W content leads to a reduction of the saturation magnetization. Fe-12at.% W coatings show an optimum combination of mechanical and magnetic properties, thus making these newly developed coatings appealing environmentally-friendly alternative materials for multi-scale technologies.

High-quality two-nucleon potentials up to fifth order of the chiral expansion

We present NN potentials through five orders of chiral effective field theory ranging from leading order (LO) to next-to-next-to-next-to-next-to-leading order (N4LO). The construction may be perceived as consistent in the sense that the same power counting scheme as well as the same cutoff procedures are applied in all orders. Moreover, the long-range parts of these potentials are fixed by the very accurate pi-N LECs as determined in the Roy-Steiner equations analysis by Hoferichter, Ruiz de Elvira and coworkers. In fact, the uncertainties of these LECs are so small that a variation within the errors leads to effects that are essentially negligible, reducing the error budget of predictions considerably. The NN potentials are fit to the world NN data below pion-production threshold of the year of 2016. The potential of the highest order (N4LO) reproduces the world NN data with the outstanding chi^2/datum of 1.15, which is the highest precision ever accomplished for any chiral NN potential to date. The NN potentials presented may serve as a solid basis for systematic ab initio calculations of nuclear structure and reactions that allow for a comprehensive error analysis. In particular, the consistent order by order development of the potentials will make possible a reliable determination of the truncation error at each order. Our family of potentials is non-local and, generally, of soft character. This feature is reflected in the fact that the predictions for the triton binding energy (from two-body forces only) converges to about 8.1 MeV at the highest orders. This leaves room for three-nucleon-force contributions of moderate size.

Pushing Chemical Boundaries with N-Heterocyclic Olefins (NHOs): From Catalysis to Main Group Element Chemistry.

N-Heterocyclic olefins (NHOs) have gone from the topic of a few scattered (but important) reports in the early 1990s to very recently being a ligand/reagent of choice in the far-reaching research fields of organocatalysis, olefin and heterocycle polymerization, and low oxidation state main group element chemistry. NHOs are formally derived by appending an alkylidene (CR2) unit onto an N-heterocyclic carbene (NHC), and their pronounced ylidic character leads to high nucleophilicity and soft Lewis basic character at the ligating carbon atom. These olefinic donors can also be structurally derived from imidazole, triazole, and thiazole-based heterocyclic carbenes and, as a result, have highly tunable electronic and steric properties. In this Account, we will focus on various synthetic routes to imidazole-2-ylidene derived NHOs (sometimes referred to as deoxy-Breslow intermediates) followed by a discussion of the electron-donor ability of this structurally tunable ligand group. It should be mentioned that NHOs have a close structural analogy with Breslow-type intermediates, N-heterocyclic ketene aminals, and β-azolium ylides; while these latter species play important roles in advancing synthetic organic chemistry, discussion in this Account will be confined mostly to imidazole-2-ylidene derived NHOs. In addition, we will cover selected examples from the literature where NHOs and their anionic counterparts, N-heterocyclic vinylenes, are used to access reactive main group species not attainable using traditional ligands. Added motivation for these studies comes from the emerging number of low coordinate main group element based compounds that display reactivity once reserved for precious metal complexes (such as H-H and C-H bond activation). Moreover, NHOs are versatile precursors to new mixed element (P/C and N/C), and potentially bidentate, ligand constructs of great potential in catalysis, where various metal oxidation states and coordination environments need to be stabilized during a catalytic cycle. The most active area of recent growth for NHOs is their use as nucleophiles to promote efficient organocatalytic transformations, including transesterification, carbonyl reduction, and the conversion of CO2 into value added products. Polyesters have also been generated through the NHO-promoted ring-opening polymerization of lactones, and the highly tunable nature of NHO organocatalysts allows for the rapid screening and enhancement of catalytic performance. Therefore, the growing utility of NHOs in the realm of organic and polymer chemistry can be viewed as evidence of the widespread impact of N-heterocyclic olefins on the chemical community. It is hoped that through this Account others will join this flourishing research domain and that the rapid recent growth of NHO chemistry is sustained for the foreseeable future.

Structural motifs in heteroleptic copper and cadmium selenites

Cu(II) cations in the presence of diamine ligands such as tetramethylethylendiamine (TMEDA) react with Na2SeO3 to produce the heteroleptic selenite copper compound of formula [Cu3(TMEDA)3(SeO3)2(H2O)4](NO3)2. In the cationic moiety two copper atoms are linked by two selenite anions through the O–Se–O bridge. One of the two bridging selenite anion coordinates to a third copper atom through the third oxygen atom. Reaction of Cd(CH3COO)2·2H2O with Na2SeO3 in the presence of ligand with softer character such as thiourea [(NH2)2CS; tu] or selenourea [(NH2)2CSe; tu] in aqueous solution afforded the complex [{Cd(tu)2SeO3}2], whose structure has been elucidated by X-ray diffraction analysis. It is the first reported example of a molecular cadmium selenite complex. Two cadmium cations stabilized by the coordination of four ancillary thiourea soft ligands, are linked together by two bridging selenite ions through O and O–Se–O bridges. A comparison between the coordination mode of the selenite ion in those cadmium and copper complexes and in inorganic extended CdSeO3 and hydrated CuSeO3 phases is also reported.

Killing of bacteria by copper, cadmium, and silver surfaces reveals relevant physicochemical parameters

The killing of bacteria on metallic copper surfaces in minutes to hours is referred to as contact killing. Why copper possesses such strong antimicrobial activity has remained enigmatic. Based on the physicochemical properties of metals, it was recently predicted that cadmium should also be active in contact killing [Hans et al., Biointerphases 11, 018902 (2010)]. Here, the authors show that cadmium is indeed antimicrobial. It kills three logs of bacteria in 9 h, compared to copper which kills eight logs of bacteria. Metallic silver kills less than one log of bacteria in 9 h. These findings support the novel concept whereby oxide formation, metal ion dissolution, and a Pearson soft character are the key factors for a metal to be antibacterial. Based on these parameters, copper and cadmium are expected to be the two most antibacterial metals.

Correlation between crystallographic texture, microstructure and magnetic properties of pulse electrodeposited nanocrystalline Nickel–Cobalt alloys

This paper reports the evolution of microstructure and texture in Nickel–Cobalt electrodeposits fabricated by pulse electrodeposition (PED) technique and the correlation of these attributes with the magnetic properties. The structural and microstructural investigation using X-ray diffraction and transmission electron microscopic studies indicate the presence of nanocrystalline grains and nano-twins in the electrodeposits. Convoluted Multiple Whole profile fitting reveals an increase in dislocation density and twin density with increasing cobalt content in the as-deposited samples. Strengthening of <111> fibre texture and weakening of <200> fibre texture with increasing cobalt concentration has been observed with X-ray texture analysis. A corresponding significant increase in the saturation magnetization and coercivity observed with increasing cobalt content. A significant improvement in the soft magnetic character in the electrodeposits in terms of increase in saturation magnetization and decrease in coercivity has been observed with thermal annealing.