Determination of fluorine in solids down to 120 μg/g by wavelength dispersive X-ray fluorescence spectrometry

An X-ray fluorescence spectrometric method is described for the determination of fluorine from percent level down to 120 g/g in fluoropolymers and in fluoride samples. The method is based on the measurement of the intensity of first order line for 30 seconds using a flow proportional counter and a multilayer AXO6 crystal (2d=5.52 nm). The calibration curves of first degree base polynomials are linear over the concentration range of 8000–120 g/g and of 48.92–76% measured. The precision and accuracy obtained for polymer samples in percent level of fluorine are up to ±0.5 and within ±1%, respectively. However, the precision () for trace concentrations is in the range from 8 to 20%. In most cases the accuracy is up to ±7%, ±5% and ±4% in the concentration range of 120–8000 g/g, 801–8000 g/g and of 120–400 g/g, respectively. The time needed to analyze one sample including calibration and regression analysis is about 8 minutes.     

Study of the occupation site for the ancient iron smelters at Samaru-west, Nigeria, using neutron activation analysis

Summary Instrumental neutron activation analysis (INAA) has been employed to investigate the relationship between three ancient occupation sites — Samaru-west, Pantaki and Tsauni in Kaduna State, Nigeria, based on the analysis of cultural deposits at the sites. Samaru-west was found to be related with Pantaki site but not so with the Tsauni site. Elemental profiles for the pottery excavated from each site have been established.     

Entropy analysis of Powell–Eyring hybrid nanofluid including effect of linear thermal radiation and viscous dissipation

Journal of Thermal Analysis and Calorimetry - Hybrid nanofluids are introduced as heat transfer fluids with greater surface stability, diffusion and dispersion capabilities compared to traditional...     

Syntheses,Spectral Studies and Bioanalyses of Some Triorganotin（IV） Complexes of Cephlaxine

Five novel triorganotin（IV） complexes have been synthesized by refluxing trimethyl, triethyl, tributyl, triphenyl and tribenzyltin chloride with Cephlaxine. These compounds were characterized by spectroscopic （IR, IH, 13C, 119Sn NMR） techniques and elemental analysis. The results obtained through these techniques are in full agreement with the proposed 1：1 stoichiometry. The synthesized compounds were than tested against various microorganisms and fungi. The results of new products obtained showed that the triphenyltin（IV） complex displayed promising activity against all types of bacteria and fungi used while all other compounds showed significant antibacterial and antifungal activity.     

Exploring the Potential of Multinuclear Solid-State 1H, 13C,and 35Cl Magnetic Resonance To Characterize Static and Dynamic Disorder in Pharmaceutical Hydrochlorides

Crystallographic disorder, whether static or dynamic, can be detrimental to the physical and chemical stability, ease of crystallization and dissolution rate of an active pharmaceutical ingredient. Disorder can result in a loss of manufacturing control leading to batch-to-batch variability and can lengthen the process of structural characterization. The range of NMR active nuclei makes solid-state NMR a unique technique for gaining nucleus-specific information about crystallographic disorder. Here, we explore the use of high-field ³⁵Cl solid-state NMR at 23.5 T to characterize both static and dynamic crystallographic disorder: specifically, dynamic disorder occurring in duloxetine hydrochloride ( 1 ), static disorder in promethazine hydrochloride ( 2 ), and trifluoperazine dihydrochloride ( 3 ). In all structures, the presence of crystallographic disorder was confirmed by ¹³C cross-polarization magic-angle spinning (CPMAS) NMR and supported by GIPAW-DFT calculations, and in the case of 3 , ¹H solid-state NMR provided additional confirmation. Applying ³⁵Cl solid-state NMR to these compounds, we show that higher magnetic fields are beneficial for resolving the crystallographic disorder in 1 and 3 , while broad spectral features were observed in 2 even at higher fields. Combining the data obtained from ¹H, ¹³C, and ³⁵Cl NMR, we show that 3 exhibits a unique case of disorder involving the ⁺N−H hydrogen positions of the piperazinium ring, driving the chloride anions to occupy three distinct sites.     

Detection of Nutrition and Toxic Elements in Dry Milk Powders Available in Pakistan Using Laser Induced Breakdown Spectroscopy

Plasma Chemistry and Plasma Processing - In this work, qualitative as well as the quantitative study of nutritional and trace toxic metals in various dry milk powders (local and branded) available...     

Zn(II) Complexes with Quinoline Supported Amidate Ligands: Synthesis,Fluorescence, and Catalytic Activity

Zn(II) complexes of N-(quinolin-8-yl)picolinamide (HL¹) (1) and N²,N⁶-di(quinolin-8-yl)pyridine-2,6-dicarboxamide (H₂L²) (2) have been synthesized by deprotonation of the ligands and characterized by IR, NMR, and Single crystal X-ray crystallography. The mononuclear [Zn(L¹)₂] (3) and homodinuclear [Zn₂(L²)₂] (4) complexes are characterized by distorted octahedral geometries stabilized by hydrogen bonding and weak π···π interaction. The complexes demonstrate intense fluorescence bands in comparison with their corresponding ligands with well-distinguished intensity. The complexes act as efficient catalysts in various transesterification reactions. Among those, the best results have been achieved with complex 3 in conversion of 4-nitrophenylacetate into methyl acetate within 3 h.

     

Reporting effective extraction methodology and chemical characterization of bioactive components of under explored Platycladus orientalis (L.) Franco from semi-arid climate

The bioactive ingredients of many essential oils are complex and difficult to reproduce synthetically. In the present study, the influence of extraction method on relative extraction of bioactive compounds of essential oil of Platycladus orientalis (L.) Franco (Thuja orientalis L. is a synonym of it) leaves gathered from semi-arid climate was studied. A higher yield of essential oil was obtained by hydrodistillation (0.1%) as compared to steam distillation (0.07%) under newly optimized conditions. Initial analysis of these oils by TLC showed the presence of different polarity groups ranging from non-polar terpene hydrocarbons to polar terpenoid alcohols. GC-MS analysis revealed that major component of hydrodistilled essential oil of Platycladus orientalis (L.) Franco leaves was α-pinene (17.83%) and steam distilled essential oil contained α-cedrol (12.44%). The results obtained in the present study emphasize that suitable extraction technique should be used to obtain particular component of interest.     

Dust ion‐acoustic solitons with trapped q‐non‐extensive electrons,dissipative processes,and streaming ions

The characteristics of dust ion‐acoustic waves (DIAWs) that are excited because of streaming ions and hot q‐non‐extensive electrons obeying a vortex‐like distribution are investigated. By exploiting a pseudo‐potential technique, we have derived an energy integral equation. The presence of non‐extensive q‐distributed hot trapped electrons and a streaming ion beam has been shown to influence soliton structure quite significantly. The evolution of the soliton‐like perturbations in complex plasmas, taking into account the dissipation processes, are also investigated, obtained by numerically solving the modified Schamel, equation whose widths are dependant on electron trapping efficiency β. Our illustrations indicate that compressive DIAWs develop in this plasma. As the plasmas in reality have a relative flow, such an analysis can be used to understand the DIA solitary structures observed in the mesospheric noctilucent clouds.     

Analysis of Spectral Temperature of Participant Protons in p + 12C Interactions at 4.2 GeV/c Using UrQMD Model

The transverse momentum spectra of protons participated in the collision processes calculated using UrQMD model simulations have been compared with the p_T spectra of participant protons, obtained experimentally in interactions of protons beam with carbon nuclei at momenta of 4.2 GeV/c. Spectral temperatures of participant protons obtained in the experimental and UrQMD model simulated interactions of protons beam with carbon nuclei have been calculated by fitting both spectra with four different fitting functions i.e. Hagedorn Thermodynamic, Boltzmann distribution, Gaussian and exponential functions. These functions are used commonly for describing the hadrons spectra and their spectral temperatures. The most suitable fitting functions among these four functions have also been recommended.