Phthalocyanine green pigments

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert Christie ◽  
Adrian Abel
Keyword(s):  
Elevated Temperatures ◽  
Eutectic Mixture ◽  
Green Product ◽  
Hydrogen Atoms ◽  
Technical Performance ◽  
Yellowish Green ◽  
Bluish Green ◽  
Copper Phthalocyanines ◽  
Green Pigments

Abstract The dominant organic green pigments are polyhalogenated copper phthalocyanines (CuPcs). These pigments exhibit similar excellent coloristic and technical performance to CuPc blue pigments and are produced worldwide in large quantities. The green pigments are halogenated CuPcs. There are two pigments with CI designations. CI Pigment Green 7 is a bluish green product, in which the 16 ring hydrogen atoms of the CuPc molecule are replaced virtually completely by chlorine. Products designated as CI Pigment Green 36 incorporate a range of bromo- and bromochlorocopper phthalocyanines and are yellowish-green pigments. CuPc green pigments are manufactured by direct exhaustive halogenation of crude CuPc blue with chlorine or bromine or an appropriate mixture of the two halogens, depending on the composition of the product required. The synthesis is carried out at elevated temperatures in a suitable solvent, commonly a molten AlCl3/NaCl eutectic mixture.

scholarly journals DIRECT SPECTROPHOTOMETRIC DETERMINATION OF ATENOLOL AND TIMOLOL ANTI-HYPERTENSIVE DRUGS

2017 ◽  
Vol 9 (3) ◽  
pp. 47 ◽  
Author(s):  
Akram M. El-didamony ◽  
Moftah A. Moustafa
Keyword(s):  
Alkaline Medium ◽  
Initial Rate ◽  
Fixed Time ◽  
Dosage Forms ◽  
Green Product ◽  
Bluish Green ◽  
Experimental Parameters ◽  
Calibration Equations ◽  
Sensitive Spectrophotometric Method

Objective: Direct and sensitive spectrophotometric method is described for the quantitative determination of some anti-hypertensive drugs such as atenolol (ATN) and timolol (TIM) in pure forms as well as in their dosage forms.Methods: The proposed method is based on the redox reaction between the selected drugs and KMnO4 in alkaline medium. The method involves treating the aqueous solution of the selected drugs with KMnO4 in alkaline medium and measuring the bluish-green product at 610 nm. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized.Results: The fixed-time method is adopted for constructing the calibration curves, which were found to be linear over the concentration ranges of 2.0–14 mg/ml and 2.0–28 mg/ml for ATN and TIM, respectively. The determination of the studied drugs by initial rate, variable time and rate constant method was workable with the calibration equations obtained but the fixed time method has been found to be more applicable.Conclusion: The applicability of the proposed method was demonstrated by the determination of the selected drugs in both pure and in commercial dosage forms and has met the validation requirements.

REACTION OF TOLUENE WITH HYDROGEN ATOMS AT ELEVATED TEMPERATURES

1972 ◽  
Vol 1 (10) ◽  
pp. 917-920 ◽  
Author(s):  
Akira Amano ◽  
Osamu Horie ◽  
Nguyen Hieu Hanh
Keyword(s):  
Elevated Temperatures ◽  
Hydrogen Atoms

Measurement of the diffusion coefficients of reactive species in dilute gases

1982 ◽  
Vol 380 (1779) ◽  
pp. 241-258 ◽  
Keyword(s):  
Gas Phase ◽  
Diffusion Coefficients ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Reactive Species ◽  
Resonance Fluorescence ◽  
Hydrogen Atoms ◽  
Chromatographic Effect ◽  
Diffusion Of Hydrogen

A technique has been developed for measuring the diffusion coefficients of atoms and other reactive species in gases below atmospheric pressure. The technique consists of measuring the rate of dispersion of a pulse of reactive species in a stream of gas flowing rapidly ( ca . 10 m s -1 ) down a quartz tube. The reactive species are observed and the profile of the pulses measured by using resonance fluorescence. The technique has been used at room temperature, but in principle measurements could be made at elevated temperatures. Measurements have been made of the rates of diffusion of hydrogen atoms in argon and nitrogen, and values for the diffusion coefficients of 1.61 ± 0.04 and 1.35 ± 0.03 cm 2 s -1 respectively, at 1 atmosphere ( ca . 10 5 Pa) and 294 K, have been obtained. Incidentally to the primary purpose of the experiment, it was observed that the hydrogen atoms spend a small fraction of their time of passage along the tube reversibly adsorbed on its walls. From the measurements, both the partition coefficient, giving the ratio of hydrogen atoms on the walls to those in the gas phase, and the rates of adsorption and desorp­tion can be obtained. This appears to be the first observation of a chromatographic effect for a highly reactive species.

Hedysarum kulikovii, new name in new rank (Fabaceae)

2018 ◽  
pp. 106-111
Author(s):  
M. S. Knyazev
Keyword(s):  
Related Species ◽  
Identification Key ◽  
Mountain Range ◽  
Ural Mountain ◽  
New Name ◽  
Green Leaves ◽  
Yellowish Green ◽  
Bluish Green ◽  
Southern Extremity

A new name in the rank of species, Hedysarum kulikovii Knjaz., is published for H. tscherkassovae Knjaz. var. intermedium Knjaz. The species occurs in mountain steppe near the southern extremity of the Ural mountain range between 50° and 52°30′ N, 56°30′ and 58°30′ E. It is characterized by evenly purple flowers (vs. bicolour with pink standard and white keel in H. tscherkassovae s. str. and H. razoumowianum Helm et Fisch. ex DC.), smooth and zigzag-curved legumes (vs. smooth and flat in H. tscherkassovae s. str., or rouleau-like folded and thorned in H. razoumowianum), bluish-green leaves remaining its colour when dry (vs. green, brown-green when dry in H. tscherkassovae s. str., or green, yellowish-green when dry in H. razoumowianum), densely hairy with appressed hairs, whitish calyx (vs. greenish, purple-tinged, thinner hairy). An identification key and map of distribution of H. kulikovii and some related species of Hedysarum sect. Multicaulia are presented.

Enhanced Sensitivity of Pt/NiO Gate Based AlGaN/GaN C-HEMT Hydrogen Sensor

2014 ◽  
Vol 605 ◽  
pp. 491-494
Author(s):  
Ivan Rýger ◽  
Gabriel Vanko ◽  
Tibor Lalinský ◽  
Jaroslav Dzuba ◽  
Martin Vallo ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Detection Efficiency ◽  
Volume Ratio ◽  
Nanocrystalline Structure ◽  
High Sensitivity ◽  
Diffusion Path ◽  
Hydrogen Gas ◽  
Semiconductor Surface ◽  
Hydrogen Atoms ◽  
Regeneration Time

In this article we demonstrate the high sensitivity AlGaN/GaN circular HEMT (C-HEMT) hydrogen gas sensor with new gate interfacial Pt/NiO layer. The wide band-gap III-nitride semiconductor heterostructure allows the sensor operation at elevated temperatures. Likewise, the C-HEMT sensing device is easy to prepare because the MESA insulation step can be omitted. Moreover, the I-V characteristics of ring gate diodes with a dominant thermionic emission of electrons can be easly achieved by elimination of tunneling currents induced on the MESA-etched edges. The Pt/NiO stacked gate absorption layer has nanocrystalline structure, what increases the surface-to-volume ratio. Consequently, the hydrogen gas is more efficiently dissociated at low temperature. Comparing to reference Pt/AlGaN/GaN diode sensor, the optimum operation temperature decreases from 250 oC towards 50oC and the hydrogen detection efficiency is enhanced about 10 times. This is desirable for battery-powered sensors with low current consumption. On the other hand, the fabricated sensor shows longer reaction and regeneration time constants. This is due to longer diffusion path that hydrogen atoms must overcome to reach the AlGaN semiconductor surface.

scholarly journals P and N type copper phthalocyanines as effective semiconductors in organic thin-film transistor based DNA biosensors at elevated temperatures

RSC Advances ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 2133-2142 ◽  
Author(s):  
Nicholas T. Boileau ◽  
Owen A. Melville ◽  
Brendan Mirka ◽  
Rosemary Cranston ◽  
Benoît H. Lessard
Keyword(s):  
Thin Film ◽  
Elevated Temperatures ◽  
Thin Film Transistor ◽  
Organic Thin Film ◽  
Dna Sensors ◽  
Dna Sensing ◽  
Organic Thin Film Transistor ◽  
Dna Biosensors ◽  
Type Semiconductor ◽  
Copper Phthalocyanines

This study illustrates the use of an N-type semiconductor, in both temperature and DNA sensors and further elucidates the mechanism of DNA sensing in OTFTs.

scholarly journals Detection of fast neutrons from D–T nuclear reaction using a 4H–SiC radiation detector

2016 ◽  
Vol 44 ◽  
pp. 1660235 ◽  
Author(s):  
Bohumir Zatko ◽  
Andrea Sagatova ◽  
Katarina Sedlackova ◽  
Vladimir Necas ◽  
Frantisek Dubecky ◽  
...  
Keyword(s):  
Nuclear Reaction ◽  
Epitaxial Layer ◽  
Elevated Temperatures ◽  
Detection Efficiency ◽  
Radiation Detector ◽  
Schottky Contact ◽  
Wide Band ◽  
Fast Neutrons ◽  
Hydrogen Atoms ◽  
Detector Material

The particle detector based on a high purity epitaxial layer of 4H–SiC exhibits promising properties in detection of various types of ionizing radiation. Due to the wide band gap of 4H–SiC semiconductor material, the detector can reliably operate at room and also elevated temperatures. In this work we focused on detection of fast neutrons generated the by D–T (deuterium–tritium) nuclear reaction. The epitaxial layer with a thickness of 105 [Formula: see text]m was used as a detection part. A circular Schottky contact of a Au/Ni double layer was evaporated on both sides of the detector material. The detector structure was characterized by current-voltage and capacitance-voltage measurements, at first. The results show very low current density (<0.1 nA/cm[Formula: see text] at room temperature and good homogeneity of free carrier concentration in the investigated depth. The fabricated detectors were tested for detection of fast neutrons generated by the D–T reaction. The energies of detected fast neutrons varied from 16.0 MeV to 18.3 MeV according to the acceleration potential of deuterons, which increased from 600 kV up to 2 MV. Detection of fast neutrons in the SiC detector is caused by the elastic and inelastic scattering on the silicon or carbide component of the detector material. Another possibility that increases the detection efficiency is the use of a conversion layer. In our measurements, we glued a HDPE (high density polyethylene) conversion layer on the detector Schottky contact to transform fast neutrons to protons. Hydrogen atoms contained in the conversion layer have a high probability of interaction with neutrons through elastic scattering. Secondary generated protons flying to the detector can be easily detected. The detection properties of detectors with and without the HDPE conversion layer were compared.

A new species of tree frog, genus Dendropsophus (Anura: Hylidae), from the Amazon of northern Bolivia

Zootaxa ◽  
2006 ◽  
Vol 1327 (1) ◽  
pp. 23 ◽  
Author(s):  
JIŘÍ MORAVEC ◽  
JAMES APARICIO ◽  
JÖRN KÖHLER
Keyword(s):  
New Species ◽  
Species Group ◽  
Advertisement Call ◽  
Tree Frog ◽  
Dorsal Skin ◽  
Yellowish Green ◽  
Bluish Green ◽  
A New Species ◽  
Lowland Amazonia

We describe a new species of small Dendropsophus from lowland Amazonia of the Departamento Pando, northern Bolivia. The new species is mainly characterized by smooth dorsal skin, indistinct tympanic annulus, lack of tarsal folds, yellowish-tan to reddish-brown dorsum with obscure dark brown markings, colouration of loreal-tympanic region and flanks sharply outlined and contrasting against dorsum and yellowish-green to bluish-green vocal sac in life. The advertisement call consists of a series of very short pulsed notes, with note repetion rate being the highest known within the species group. Regarding the morphological similarities of adults, the new species is tentatively grouped with species placed in the Dendropsophus microcephalus group.

Sign in / Sign up

Export Citation Format

Share Document