The effect o f K-picrate-18-crown-6 (crown) on the photoelectron transport activity o f beet spinach thylakoid membranes was investigated. Addition o f micromolar concentration o f crown to thylakoid preparation inhibited p-benzoquinone, chloride-indophenol, methyl viologen supported Hill activities maximally by 75 per cent in a concentration dependent manner. However, the photosystem I catalyz...

The pH-profiles of the extraction of Cs(+) into four conventional (1-butyl-3-methylimidazolium hexafluorophosphate and bis[trifluoromethyl)sulphonyl]imides of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-(2-ethylhexyl)-3- methylimidazolium) and two novel (trioctylmethylammonium salicylate and tetrahexylammonium dihexylsulfosuccinate) room temperature ionic liquids have been d...

crown ethers 12-crown-4 (12c4), benzo-15-crown-5 (b15c5), 18-crown-6 (18c6), nitrobenzo-18-crown-6 (nb18c6) dibenzo-18-crown-6 (db18c6) and dicyclohexyl-18-crown-6 (dc18c6), dissolved in dichloromethane, are able to form oxonium-ion complexes in contact with aqueous sulfuric and hydrochloric acid solutions. this ability allows the transfer of cr(vi) oxanions from the acid media, through an orga...

In this paper, the laser bending process of a circular tube made of mild steel has been investigated experimentally. For this purpose, the effects of the irradiating length and the number of irradiating passes on the main bending angle of a laser bent tube are studied. In addition, the main defects of the laser tube bending process such as lateral bending angle, ovality and thickness variation ...

Stem diameter at breast height (DBH) and tree height (H) are commonly used measures of tree growth. We examined patterns of height growth and diameter growth along a stem using a 20-year record of an even-aged hinoki cypress (Chamaecyparis obtusa (Siebold & Zucc.) Endl.) stand. In the region of the stem below the crown (except for the butt swell), diameter growth rates (ΔD) at different heights...

Two procedures for the synthesis of benzo-21-crown-7 have been explored. The [1+1] macrocyclization with KBF₄ as the template was found to be more efficient than the intramolecular macrocyclization without template. Pseudorotaxanes form with secondary ammonium ions bearing at least one alkyl chain narrow enough to slip into the crown ether. Substitution on benzo-21-crown-7 or on the secondary a...

scape bending disorder is the most important factor affecting postharvest loss of gerbera cut flowers. one of the ultimate reasons for gerbera stem bending is lignin, with deformation structural functions and defensive mechanisms. this postharvest experiment was conducted to evaluate the role of phenylalanine ammonia lyase (pal) and peroxidase (pod) enzymes activity in stem bending of two gerbe...

Four-roll bending process is usually used for manufacturing of seamed thick-walled and thin-walled cylinders. Due to complexity of this process, the analytical solution of plate bending in this process has not been developed completely. The existence of friction and multi-step processing makes it more difficult. Investigation of four-roll bending process using analytical and numerical methods i...

Today, the use of high-density polyethylene (HDPE) transfer lines is increasing day by for drinking water, wastewater, sewerage networks, rainwater drainage lines, water transport structures, and natural energy sources, etc. In this study, flexible HDPE pipes were embedded in a trench to expose them variable relative density different thermal conditions so that resulting deformation behavior co...