Search results for "Barium"

Inhibition of the precipitation of barium salts in sodium dodecyl sulfate/0.1 M HCl/n-pentanol microemulsions and liquid crystals

1989

Abstract The phase ternary diagram of the sodium dodecyl sulfate (SDS)/0.1 M HCl/n-pentanol system is studied. Three monophase regions were observed: water rich and n-pentanol rich microemulsions, and a liquid crystal. These media have a strong ability to control the rate of crystal growth of barium sulfate and barium dodecyl sulfate, the precipitation being totally inhibited in the liquid crystal region.

Reactivity and Structural Defects in Glaserite-Type Iron-Vanadates

2018

Spectrofluorimetric determination of emetine by flow injection using barium peroxide and UV derivatization

1993

Abstract The flow-injection spectrofluorimetric determination of emetine was carried out by photoderivatization in the presence of barium peroxide, in a flow-injection assembly in which the PTFE tubing in the injection valve is helically coiled around the lamp. The sample solution merges with a barium peroxidephosphoric acid solution and then the resulting mixture is irradiated; pure distilled water is used as a carrier stream. The calibration graph is linear over the range 0.05–50 μ g ml −1 of emetine dihydrochloride. The influence of foreign compounds was studied and the method was applied to the determination of emetine in injection and human urine samples.

An ultrasound-assisted digestion method for the determination of toxic element concentrations in ash samples by inductively coupled plasma optical em…

2007

Abstract A method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of toxic element concentrations (arsenic, barium, cobalt, copper, lead, nickel, strontium, vanadium and zinc) in ash samples was developed. All the measurements were performed in robust plasma conditions which were tested by measuring the Mg(II) 280.270 nm/Mg(I) 285.213 nm line intensity ratios. The highest line intensity ratios were observed when a nebulizer gas flow of 0.6 L min−1, auxiliary gas flow of 0.2 L min−1 and plasma power of 1400 W were used for radially viewed plasma. The analysis of SRM 1633b showed that the ultrasound-ass…

Is <i>Limonium cavanillesii</i> Erben (Plumbaginaceae) really an extant species?

1999

A new triploid apomictic species (Limonium perplexum) is described from a single coastal locality of E Spain. The new species has been previously confused with L cavanillesii Erben, which is only known from few herbarium specimens and it is believed to be extinct. Overall morphology, chromosome number, and the pollen/stigma combination suggest that L perplexum belongs to the L. duriusculum complex. Based on morphological grounds it is suggested that L. cavanillesii Erben could have been originated through a crossing between L perplexum and L dufourii .

The genusThymus(Lamiaceae) in Sicily

2015

An update on the taxonomy and geographic distribution of the genus Thymus in Sicily is given. This study is based on literature, herbarium and field investigations. In total, five taxa belonging to Thymus sect. Serpyllum (Th. richardii subsp. nitidus, Th. longicaulis and Th. praecox subsp. parvulus) and Th. sect. Hyphodromi (Th. spinulosus and Th. paronychioides) occur in Sicily. For each one, information about taxonomy, habitat, phenology, chromosome number and distribution are provided. Furthermore, the name Thymus pedicillatus Lojac. is here typified. Finally, an analytical key for the identification of the studied taxa is proposed.

Algebraic value of the electrooptic coefficients and nature of charge carriers in batio3single crystals

1989

Abstract Some monodomain pure and Fe doped barium titanate monocrystals are studied. The algebraic values of the electrooptic coefficients r 13 and r 33 are evaluated using an interferometric method. Then, from energy transfer results it is possible to conclude that majority carriers are positive charges in all the samples.

Verlaufskontrolle des Morbus Crohn: Kann die Hydro-MRT die fraktionierte Magen-Darm-Passage ersetzen?

1997

PURPOSE: To compare the value of hydro-MRI with follow-through examinations in the follow-up of Crohn's disease. METHOD: 22 patients known to be suffering from Crohn's disease were examined via 1.5 T-MR system; an oral contrast examination using 1000 ml of a 2.5% mannitol solution was performed in all patients. T2-weighted TSE sequences and T1-weighted SE sequences were performed before and after the intravenous injection of Gd-DTPA. To reduce movement artifacts caused by peristalsis of the gut, intravenous injection of 40 mg Buscopan was given. The findings of hydro-MRI were compared with the follow-through examinations. RESULTS: In the upper gastrointestinal tract, the follow-through exam…

First record of Tamarix meyeri (Tamaricaceae) for western Europe

2012

Abstract Field investigations and herbaria reference work carried out in Italy and Spain allowed us to identify wild and cultivated plants of Tamarix meyeri, a new species from western Europe. This small tree is characterized by tetramerous, rarely pentamerous flowers and a paralophic disk.

Type designation of the name of the conifer Araâr-tree Tetraclinis articulata (Cupressaceae)

2018

The typification of the name Tetraclinis articulata (Cupressaceae) is discussed. Previous type designation is considered ineffective. Original material conserved in the herbarium of the Natural History Museum of Denmark at C is designated as the lectotype.