Characteristic Growth Features and Etching of InBi Single Crystals

The characteristic growth features observed on the top free surface of InBi single crystals grown by the zone-melting method are reported. These features are analysed by stereographic technique and a possible mechanism responsible for the appearance of the characteristic growth features is discussed. A new etchant capable of revealing dislocations inclined to the cleavage plane is also reported.     

Thermophysical properties of iridium at finite temperature

The bulk properties of materials in an extreme environment such as high temperature and high pressure can be understood by studying anharmonic effects due to the vibration of lattice ions and thermally excited electrons.In this spirit,in the present paper,anharmonic effects are studied by using the recently proposed mean-field potential(MFP) approach and Mermin functional which arise due to the vibration of lattice ions and thermally excited electrons,respectively.The MFP experienced by a wanderer atom in the presence of surrounding atoms is constructed in terms of cold energy using the local form of the pseudopotential.We have calculated the temperature variation of several thermophysical properties in an extreme environment up to melting temperature.The results of our calculations are in excellent agreement with the experimental findings as well as the theoretical results obtained by using first principle methods.We conclude that presently used conjunction scheme(MFP+pseudo potential) is simple computationally,transparent physically,and accurate in the sense that the results generated are comparable and sometimes better than the results obtained by first principle methods.Local pseudopotential used is transferable to extreme environment without adjusting its parameters.     

Dark-Field Microscopic Study of Cellular Uptake of Carbon Nanodots: Nuclear Penetrability

Carbon nanodots are fascinating candidates for the field of biomedicine, in applications such as bioimaging and drug delivery. However, the nuclear penetrability and process are rarely studied and lack understanding, which limits their applications for drug carriers, single-molecule detection and live cell imaging. In this study, we attempt to examine the uptake of CNDs in cells with a focus on the potential nuclear penetrability using enhanced dark-field microscopy (EDFM) associated with hyperspectral imaging (HSI) to quantitatively determine the light scattering signals of CNDs in the cells. The effects of both CND incubation time and concentration are investigated, and plausible nuclear penetration involving the nuclear pore complex (NPC) is discussed. The experimental results and an analytical model demonstrate that the CNDs’ uptake proceeds by a concentration-dependent three-stage behavior and saturates at a CND incubation concentration larger than 750 µg/mL, with a half-saturated concentration of 479 μg/mL. These findings would potentially help the development of CNDs’ utilization in drug carriers, live cell imaging and other biomedical applications.     

Some Properties of Si,Ge, and α-Sn Using Pseudopotential Theory

The pseudopotential theory beyond second order with our well establishedsingle parametric model potential is employed to compute total crystalenergy, static bulk modulus, energy band gap at the point X on theJones-zone face and pressure-volume relation (equation of state underpressure) of Si, Ge and α-Sn using Nagy's static local field correction function. The results are compared with those obtained using few other local field correction functions. The present results of total energy are in good agreement with the experimental data. Bulk modulus calculated byNagy's screening function is perfectly matching with the experimentalresults for Ge and α-Sn. Some deviation is found in the value of energy band gap.     

Chain-growth polycondensation via the substituent effect: Investigation in to the role of initiator and base on the synthesis of poly(N-octyl benzamide)

A detailed investigation into the role of initiator structure, the presence of an initiator, and basicity of the non-nucleophilic base in the chain-growth condensation (CGC) synthesis of poly(N-octyl benzamide) was conducted. A series of phenyl ester dimethyl amide initiators with different leaving groups were synthesized and used in the CGC preparation of poly(N-octyl benzamide). Additional polymerizations were conducted without the presence of an initiator and with different non-nucleophilic bases. Kinetic studies, along with nuclear magnetic resonance spectroscopy and gel-permeation chromatography, were used to determine progress of the reaction, molecular weights, and molecular weight distributions. The experimental and computational results demonstrated that initiators containing electron-withdrawing substituent phenyl esters, such as the p-nitrophenyl ester, and electron-withdrawing carbonyl character on the parent benzoate produce polymers with controllable molecular weights and narrow molecular weight distributions. Whereas, initiating species that contain electron-donating character on the benzoate backbone, such as dimethylamino and methyl ester groups, produce polymers that resemble the results from reactions involving no initiators at all, indicating poor polymerization control.     

Growth and etching of anhydrous diglycine sulfate single crystals

Single crystals of anhydrous diglycine sulfate are grown at constant temperature by evaporation method. The crystals are grown at various temperatures and their growth rate is determined. A chemical etchant for dislocation studies is reported. The perfection of the crystals grown at various temperatures has been studied using etching technique. It is found that the crystals contained inclusions of the mother liquid. The crystals grown below 28° are almost free of inclusions and the dislocation density is also low.     

Growth and Morphological Studies of Anhydrous Diglycine Sulfate Single Crystals

Diglycine sulfate single crystals are grown from aqueous solution by evaporation method. The effect of growth conditions are studied with respect to the perfection and morphology of the crystals. The seed history, growth temperature and pH of the solution are found to bear pronounced effects. The results are reported in the present paper.     

A simple isocratic LC method for quantification of trace-level inorganic degradation impurities (ferricyanide,ferrocyanide, nitrite,and nitrate) in sodium nitroprusside injection and robustness by quality using design approach

This study developed and validated a trace-level quantification inorganic impurities method using reversed-phase HPLC and performed the robustness check using quality-by-design approach by varying the multiple factors simultaneously. This method is economical and simple and exhibits its stability-indicating nature [for the determination of ferrocyanide ([Fe(CN)₆]^4–), ferricyanide ([Fe(CN)₆]³⁻), nitrate (NO₃^–), and nitrite (NO₂^–)] in sodium nitroprusside (SNP) drug substance and liquid dosage form. Chromatographic separation was achieved using a USP L43 column (ACE PFP, 150 × 4.6 mm, 3 μm) with a simple isocratic elution. The buffer consists of potassium dihydrogen phosphate (50 mM), tetrabutylammonium hydrogen sulfate (9 mM), and tetrabutylammonium hydroxide (25 mM). The buffer pH was adjusted to 7.2 with tetrabutylammonium hydroxide. The mobile phase was mixed with the buffer and acetonitrile (68:32 v/v). The flow rate was 0.8 mL/min, column temperature was maintained at 30°C, and injection volume was 5.0 μL. The SNP impurities were monitored at 225 nm using a UV detector. Further, the method was validated per the International Council for Harmonisation (ICH) guidelines, and forced degradation studies were carried out under different stress conditions. The detector responses were plotted against concentrations, and correlation was linear (r > 0.999) over the range of 0.8–7.5 μg/mL for ferricyanide; 1.0–37.5 μg/mL for SNP; and 0.2–7.5 μg/mL for ferrocyanide, nitrite, and nitrate. The method repeatability was established for all the impurities with relative standard deviation (%), and the results were found to be less than 2.0.     

The study of anharmonic properties and s-p-d hybridization in barium at extreme environment

Theory of pseudopotential has been used in the present study to carry out computation of various thermodynamic parameters of barium. The role of anharmonic effect due to vibrations of lattice ions has been accounted by coupling local pseudopotential with mean field potential which has been computed using second-order perturbation theory. Contribution due to thermally excited electrons has been accounted by Mermin functional. The excellent agreement of presently computed pressure with experimental result has also been observed at which body centered cubic to hexagonal close packed structure phase transition occurs. Such success leads to conclude that the s-p-d hybridization and anharmonic effects are included properly in the presently used conjunction scheme with additional advantage of its computational simplicity.