Determination of replacement of some inorganic elements in pulvinus of bean (Phaseolus vulgaris cv. Gina 2004) at chilling temperature by the WDXRF spectroscopic technique

In this study, bean seedlings (Phaseolus vulgaris cv. Gina 2004) were exposed to chilling temperatures until leaves are wrinkled (9 day), that is, showed nyctinastic movement. Pulvinus were subsequently were cut from the leaves. Concentrations of inorganic elements (P, S, Cl, K, Ca, Cu) in the pulvinus were measured by wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry. Results indicated that concentration change (%) was not significant for Ca (0.82) but it was significant for K, P, Cl, S, and especially Cu concentrations (5.4%, 12.8%, 40.2%, 43.7%, 365%, respectively) in pulvinus of plants exposed to chilling temperature compared with control group.We hypothesize here the presence of association between nyctinasti movement brought about by pulvinus at chilling temperature in bean and changes of K, P, Cl, S and especially Cu concentrations measured by WDXRF analysis method.     

Hermite hyperbolic/sinusoidal Gaussian beams in ABCD systems

For a Hermite hyperbolic/sinusoidal Gaussian beam with focusing properties, passing through an arbitrarily shaped rectangular aperture on the source plane and an on-axis x–y asymmetric ABCD system, the receiver plane expression is derived using the Collins integral. The specific example of a single thin lens placed on the propagation path is examined at selected source, propagation and optical element parameters. Viewing the progress of the beam in propagation, we find that subjecting the source beam to an aperture will give rise to excessive spreading during propagation. The lens setup will act to concentrate the energy of the beam around its focal point as expected, while in some circumstances it will also execute beam profile changes. By adjusting the aperture opening in the shape of a narrow slit, the beam will become aligned in the opposite direction after propagating after having traveled sufficiently. The results are presented as intensity graphs in the form of contour plots and 3D illustrations.     

Effect of Grinding Media Shapes on Breakage Parameters

In the present study, the effect of grinding media shape on breakage parameters was investigated. Balls and cylpebs were used as the grinding media. It was observed that the grinding of quartz obeyed first‐order breakage kinetics in the case of balls and cylpebs. Higher breakage rates were noted with cylpebs than with balls. Furthermore, it was found that the primary breakage distribution function is dependent on the feed size (i.e., non‐normalizable), but independent of the grinding media shape. The effect of grinding time on the product size distribution has also been investigated. Following four and ten minute grindings, cylpebs produced a relatively finer product compared to balls.     

The synthesis and characterization of 22-membered diazapentathia macrocycles and investigation of their ion extraction capability from aqueous media

Two new macrocyclic ligands, (5) and (6), containing nitrogen–sulfur donor atoms were designed and synthesized in a multi-step reaction sequence. Ion extraction capability of macrocycles (5) and (6) were investigated involving solvent extraction of metal picrates such as Ag⁺, Hg²⁺, Cd²⁺, Zn²⁺, Cu²⁺, Ni²⁺, Mn²⁺, Co²⁺ and Pb²⁺ from aqueous phase to the organic phase. The metal picrate extractions were carried out at 25 ± 0.1 °C and extractions were measured by u.v.–visible spectrometry. The extractability and selectivity of the mentioned metal picrates were evaluated depending on the organic solvents used for extraction. The extraction constant (log K_ex) and the complex composition of each metal complex were determined using spectroscopic methods.     

Antibacterial, Antiurease, and Antioxidant Activities of Some Arylidene Barbiturates

Some series of arylidene barbiturates and thiobarbiturates were evaluated for their antibacterial, antioxidant, and urease inhibition activities. The arylidene barbiturates and thiobarbiturates were tested for antimicrobial activity using the agar well diffusion technique against 13 bacteria. The synthesized compounds (1a–g) were screened for antiurease and antioxidant activities. The results showed that the synthesized compounds (1a–g) had effective antiurease, antioxidant, and antibacterial activities.     

A Kinetic Study of Acid-Catalyzed Hydrolysis of Some Arylsulfonyl Phthalimides

The acid-catalyzed hydrolysis of arylsulfonyl phthalimides was studied in aqueous solutions of sulfuric, perchloric, and hydrochloric acid at 35.0 ± 0.1°C. Analysis of the data by the excess acidity method and activation parameters, as well as substituent and solvent isotope effects, indicate hydrolysis by an A-2 mechanism at low acidity. At higher acidities, a changeover to an A-1 mechanism is observed.     

The Synthesis and Substituent Effect of the Acid Catalyzed Hydrolysis of Amidosulfites

The acid-catalyzed hydrolysis of 2-oxo-3-(p-substituted)-phenyl-5-methyl-1,2,3-oxathiazolidines (1) have been studied in 60% (v/v) 1,4 dioxane-aqueous solutions of perchloric and hydrochloric acids at 10.0 ± 0.05°C. The analysis of the kinetic data by the order of the catalytic effects of the acids, activation parameters, kinetic solvent isotope effect, and substituent effect are all in agreement with an A-2 mechanism in the studied range.     

Microwave-Assisted Synthesis of Disulfides

Abstract

A new microwave-assisted synthesis methodology for the preparation of substituted disulfide derivatives is presented. 4-Substituted sulfenimides were reacted with 4-substituted thiols under neat (to right doughy consistency) conditions in chloroform, with both microwave heating and conventional methods. The resulting 4-substituted disulfide derivatives were obtained at higher yields and in shorter reaction times with microwave heating. Their chemistry was confirmed by ¹H-NMR, ¹³C-NMR, infrared (IR), and elemental analysis.

GRAPHICAL ABSTRACT     

Synthesis and Characterization of Polyindole/Poly(vinyl acetate) Conducting Composites

Composites of a polyindole (PIN) and poly(vinyl acetate) (PVAc) were prepared chemically using FeCl₃ as an oxidant agent in anhydrous media. The composite compositions were altered by varying the indole monomer during preparation. The composites were characterized by FTIR and UV‐visible spectroscopies, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), stress‐strain experiments and conductivity measurements. Moreover, the film of PVAc and PIN/PVAc composites were prepared by casting on glass Petri dishes to examine their stress‐strain properties. PIN/PVAc composites are thermally more stable than PIN. It was found that the conductivities of PIN/PVAc composites depend on the indole content in the composites.     

Evolution of magnetic and structural properties of TiO2 with Co-doping

This paper presents the phase formations and magnetic properties of Co-doped TiO₂ synthesized by the colloidal and ammonium nitrate melt techniques (ANMT). The phase formations and ferromagnetic properties were studied with XRD and SQUID magnetometry. Crystallization of the TiO₂ rutile lattice was completed at 1000 °C and that was preserved during annealing up to 1300 °C. For the samples annealed at 1200 °C, elemental analysis has shown that the colloidal technique leads to a single-phase rutile with cobalt concentration of almost nothing even in the initially 0.5 mol Co-added samples. Further increase of annealing temperature results in the appearance of other Ti-phases in addition to the rutile. On the other hand, it is quite interesting that these samples show ferromagnetic behavior. The samples synthesized by the ANMT method contain larger amounts of Co compared to the colloidal technique.