scholarly journals Ex-Situ Synthesis and Study of Nanosized Mo-Containing Catalyst for Petroleum Residue Hydro-Conversion

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 649 ◽  
Author(s):  
Malkan Kh. Kadieva ◽  
Anton L. Maximov ◽  
Khusain M. Kadiev
Keyword(s):  
Elemental Sulfur ◽  
Petroleum Residue ◽  
Morphological Features ◽  
Water Soluble ◽  
Ex Situ ◽  
Coke Yield ◽  
Concentrated Suspensions ◽  
Synthesis Conditions ◽  
Single Pass ◽  
Mo Content

This study represents the results of ex-situ synthesis and research of the properties of concentrated suspensions with new catalysts for petroleum residue hydro-conversion. Suspensions were prepared and stabilized in a petroleum residue medium through reverse emulsions containing water-soluble Mo-precursor and S-containing agents (elemental sulfur, thiocarbamide) in the absence of a solid carrier. The resulting ex-situ catalyst dispersions had Mo content of 6–10 wt % and contained nanosized and submicron catalyst particles stabilized in a petroleum residue medium. The effects of S-containing agents on the properties of catalytic particles (sulfidation level, dispersity, structural and morphological features) were studied. The synthesis conditions for the optimal ex-situ catalyst providing the lowest coke yield (0.2 wt %) and the highest conversion (55.5 wt %) during petroleum residue hydro-conversion in a single pass mode have been determined.

Monoazo (Monohydrazone) pigments based on 2-naphthol and derivatives

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert Christie ◽  
Adrian Abel
Keyword(s):  
Metal Salt ◽  
Water Soluble ◽  
Anionic Dyes ◽  
Extensive Discussion ◽  
Synthesis Conditions ◽  
Organic Pigments ◽  
Amide Derivatives ◽  
The Individual ◽  
Coupling Components ◽  
Group 1

Abstract This chapter describes the range of industrial monoazo pigments based on the 2-naphthol (β-naphthol) ring system. This group includes some of the earliest organic pigments introduced commercially and is also numerically the largest group of products currently described in the Colour Index. Most of the pigments within this group are red (with a few oranges), thus complementing the azoacetoacetanilides, which are mostly yellows. Three groups of monoazonaphthol-based pigments may be identified categorized according to the chemical structure of the coupling components used in their synthesis. The first group contains products based on 2-naphthol itself, a second is based on amide derivatives of 3-hydroxy-2-naphthoic acid (naphtharylamides), and the third is a series of metal salt azo pigments. The historical development of these pigments, outlined in an early section of this chapter, originated in the late 19th century with pigments described as ‘lakes’, derived from water-soluble anionic dyes absorbed on to inert colorless substrates, which were the forerunners of products now referred to as metal salt pigments. The non-ionic 2-naphthol-based pigments were introduced soon after. In the early to mid-20th century, a series of monoazonaphtharylamide (Naphthol AS) pigments were developed and introduced commercially. The pigments of this type that are currently manufactured can be sub-divided into products containing a single amide group (group 1) and higher performance products containing more than one amide or sulfonamide groups. Several group 1 pigments have diminished in importance over the years, while some higher performing group 2 pigments have grown in importance. The molecular and crystal structures of the range of pigments are presented and discussed in relation to their performance characteristics. The manufacture of the pigments involves the reaction of a diazotized aromatic amine with the appropriate 2-naphthol-based coupling component, using synthesis conditions typical of phenolic coupling components, followed by conditioning aftertreatments that are typical for azo pigments in general. Finally, there is an extensive discussion of the wide-ranging applications in which the individual pigments are used. While the pigments are especially well-suited to printing ink applications, many products also find use in paints and a few in plastics.

scholarly journals K-paracelsian (KAlSi3O8·H2O) and identification of a simple building scheme of dense double-crankshaft zeolite topologies

IUCrJ ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Cristian-R. Boruntea ◽  
Peter N. R. Vennestrøm ◽  
Lars F. Lundegaard
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Space ◽  
Ex Situ ◽  
Zeolite Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Small Pore ◽  
Scanning Electron

During screening of the phase space using KOH and 1-methyl-4-aza-1-azoniabicyclo[2.2.2]octane hydroxide (1-methyl-DABCO) under hydrothermal zeolite synthesis conditions, K-paracelsian was synthesized. Scanning electron microscopy, energy dispersive X-ray spectroscopy and ex situ powder X-ray diffraction analysis revealed a material that is compositionally closely related to the mineral microcline and structurally closely related to the mineral paracelsian, both of which are feldspars. In contrast to the feldspars, K-paracelsian contains intrazeolitic water corresponding to one molecule per cage. In the case of K-paracelsian it might be useful to consider it a link between feldspars and zeolites. It was also shown that K-paracelsian can be described as the simplest endmember of a family of dense double-crankshaft zeolite topologies. By applying the identified building principle, a number of known zeolite topologies can be constructed. Furthermore, it facilitates the construction of a range of hypothetical small-pore structures that are crystallo-chemically healthy, but which have not yet been realized experimentally.

scholarly journals Structures and Interactions of Transmembrane Targets in Native Nanodiscs

2019 ◽  
Vol 24 (10) ◽  
pp. 943-952 ◽  
Author(s):  
Michael Overduin ◽  
Mansoore Esmaili
Keyword(s):  
Posttranslational Modifications ◽  
Protein Complexes ◽  
Biological Membrane ◽  
Water Soluble ◽  
Ex Situ ◽  
Linear Polymers ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Biologically Relevant

Transmembrane proteins function within a continuous layer of biologically relevant lipid molecules that stabilizes their structures and modulates their activities. Structures and interactions of biological membrane–protein complexes or “memteins” can now be elucidated using native nanodiscs made by poly(styrene co-maleic anhydride) derivatives. These linear polymers contain a series of hydrophobic and polar subunits that gently fragment membranes into water-soluble discs with diameters of 5–50 nm known as styrene maleic acid lipid particles (SMALPs). High-resolution structures of memteins that include endogenous lipid ligands and posttranslational modifications can be resolved without resorting to synthetic detergents or artificial lipids. The resulting ex situ structures better recapitulate the in vivo situation and can be visualized by methods including cryo-electron microscopy (cryoEM), electron paramagnetic resonance (EPR), mass spectrometry (MS), nuclear magnetic resonance (NMR) spectroscopy, small angle x-ray scattering (SAXS), and x-ray diffraction (XRD). Recent progress including 3D structures of biological bilayers illustrates how polymers and native nanodiscs expose previously inaccessible membrane assemblies at atomic resolution and suggest ways in which the SMALP system could be exploited for drug discovery.

scholarly journals Acid-Modified and Unmodified Natural Clay Deposits for In Situ Immobilization and Reducing Phytoavailability of Molybdenum in a Sandy Loam Calcareous Soil

2020 ◽  
Vol 12 (19) ◽  
pp. 8203
Author(s):  
Saleh H. Alrashidi ◽  
Abdelazeem S. Sallam ◽  
Adel R. A. Usman
Keyword(s):  
Dry Matter ◽  
Sandy Loam ◽  
Calcareous Soils ◽  
Application Rate ◽  
Ammonium Bicarbonate ◽  
Water Soluble ◽  
Modified Clay ◽  
Clay Deposits ◽  
Reduction Effect ◽  
Mo Content

Molybdenum (Mo) in basic soils has high bioavailability and plant toxicity. This study aimed to investigate the effect of increasing Mo concentration on its availability and toxicity threshold in alfalfa plants grown in sandy loam calcareous soils, and the potential use of raw and acid- modified clay deposits as soil additives to immobilize Mo and reduce its phytoavailability. Raw clay deposits (RCD) were treated with H2SO4 to produce acid-modified clay deposits (AMCD). The first experiment was performed using soils treated with 0, 0.1, 1, 10, 50, and 100 mg Mo kg−1. The second experiment was conducted with soils treated with 10 or 50 mg Mo kg−1 and amended with RCD and AMCD at application rates of 0, 2.5, 5, and 10% (w/w). After harvesting, water-soluble Mo, ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA)-extractable Mo, and shoot Mo content as well as dry matter were measured. The results showed that water-soluble Mo, AB-DTPA-extractable Mo, and shoot Mo concentration increased at higher Mo soil addition. AMCD had a stronger influence on Mo immobilization and reduction effect on plant shoots compared to RCD, depending on soil Mo concentration and application rate. Applying AMCD decreased soil pH but increased salinity levels. The shoot dry matter significantly increased in soils amended with RCD and/or AMCD compared to control soils; with the highest improvement recorded for RCD at 10%. It was concluded that AMCD is an efficient immobilizing agent to reduce Mo mobility and its phytoavailability in calcareous soils. Additionally, both AMCD and especially RCD were able to create favorable conditions for plant growth.

Electron microscope investigation of aluminium-comprising nanoparticles

2014 ◽  
Vol 11 (3) ◽  
pp. 209-212 ◽  
Author(s):  
N. Antonova
Keyword(s):  
Electron Microscope ◽  
Morphological Features ◽  
Water Soluble ◽  
Sodium Carboxymethylcellulose ◽  
New Approach ◽  
Water Soluble Polymers ◽  
Electron Microscope Investigation ◽  
Soluble Polymers ◽  
Microscope Investigation ◽  
Heating Up

A new approach was suggested for creating nano-dimensional materials based on water-soluble polymers. Nano-seized Al-contained structures were synthesized; such structures were screened by a cover of sodium-carboxymethylcellulose by heating up to 70-80 degrees of Celsius of a sodium-carboxymethylcellulose's polymere with Al microparticles with dimension less than 20 mkm. Morphological features of created composites were researched. It was established that agglomerates of received particles were reached values of 300-600 nm and consisted of tubular types' structures with dimensions 80-100 nm.

Versatile cell for in-situ spectroelectrochemical and ex-situ nanomorphological characterization of both water soluble and insoluble phthalocyanine compounds

2016 ◽  
Vol 147 (8) ◽  
pp. 1393-1400 ◽  
Author(s):  
Věra Mansfeldová ◽  
Monika Klusáčková ◽  
Hana Tarábková ◽  
Pavel Janda ◽  
Karel Nesměrák
Keyword(s):  
Water Soluble ◽  
Ex Situ

High Temperature - FTIR Characterization of Gadolinia Doped Ceria

2010 ◽  
Vol 72 ◽  
pp. 249-254
Author(s):  
Aliye Arabaci ◽  
Nuri Solak
Keyword(s):  
High Temperature ◽  
Thermal Analyses ◽  
Water Soluble ◽  
Ex Situ ◽  
Doped Ceria ◽  
X Ray Diffraction ◽  
Ftir Characterization ◽  
Ft Ir ◽  
Xrd Techniques

Doped ceria-based (DC) materials have recently been considered as the most promising solid electrolytes for intermediate temperature solid oxide fuel cell (IT-SOFC) applications. Doped ceria is usually prepared via thermal decomposition of its water soluble salts, especially, acetates and nitrates. The properties of the obtained final product directly influenced by the starting material and the decomposition products. Therefore, it is crucial to understand the decomposition steps and intermediate products. Number of experimental work have been reported using various <em>in-situ</em> and <em>ex-situ</em> techniques such as thermogravimetry with mass spectrometry (TG/DTA-MS), X-ray diffraction with differential scanning calorimeter (XRD-DSC). However, the available literature data is limited and not reasonably in agreement with each other. High Temperature FT-IR spectroscopy, TG/DTA-MS, XRD, techniques were used and results are compared with literature. A good agreement between the thermal analyses and HT-FTIR results were obtained. Possible decomposition mechanism is discussed.

SYNTHESIS AND PHOTOLUMINESCENCE OF WATER-SOLUBLE ZnS:Mn2+/ZnS QUANTUM DOTS BY NUCLEATION DOPING STRATEGY

NANO ◽  
2011 ◽  
Vol 06 (01) ◽  
pp. 75-79 ◽  
Author(s):  
ZHANGSEN YU ◽  
XIYING MA
Keyword(s):  
Quantum Dots ◽  
Solution Structure ◽  
Thioglycolic Acid ◽  
Luminescent Properties ◽  
Fluorescent Labeling ◽  
Water Soluble ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions

We report the synthesis of luminescent-doped core/shell quantum dots (QDs) of water-soluble manganese-doped zinc sulfide (ZnS:Mn2+/ZnS) . QDs of ZnS:Mn2+/ZnS were prepared by nucleation doping strategy, with thioglycolic acid (TGA) as stabilizer in aqueous solution. Structure and optical properties of the ZnS:Mn2+/ZnS core/shell quantum dots were characterized by X-ray diffraction and photoluminescence emission spectroscopy. The influence of the synthesis conditions on the luminescent properties of ZnS:Mn2+/ZnS QDs is discussed. Different Mn2+ concentrations, ratios of the TGA/ (Zn+Mn) and thickness of the ZnS shell were used. Results showed that the ZnS:Mn2+/ZnS QDs are water-soluble and have improved fluorescence properties. Therefore, Mn2+ -doped ZnS quantum dots could be potential candidates as fluorescent labeling agents in biology.

Structure and functions of the digestive tract of Alvinella pompejana, a hydrothermal vent polychaete

1990 ◽  
Vol 68 (4) ◽  
pp. 722-732 ◽  
Author(s):  
C. Saulnier-Michel ◽  
F. Gaill ◽  
A. Hily ◽  
P. Alberic ◽  
M. A. Cosson-Mannevy
Keyword(s):  
Digestive Tract ◽  
Elemental Sulfur ◽  
Anterior Part ◽  
Water Soluble ◽  
High Concentration ◽  
Oesophageal Gland ◽  
Alvinella Pompejana ◽  
Deposit Feeding ◽  
Structure And Functions ◽  
Soluble State

The different parts of the digestive tract of Alvinella pompejana are described. The buccal apparatus presents a ventral pharyngeal organ, which is thought to be protrusible, and a dorsal anterior oesophageal gland. Unusual racks are observed in this part, a fact that confirms the deposit feeding behaviour of the worm which has been hypothetized. The serous cells of the oesophageal gland may be the origin of the proteolytic activity detected in the lumen. Intracellular enzymatic activities are detected in the stomach cells. These cells are characterized by numerous iron concretions and polyphagosomes. Comparative elemental analysis of these concretions lead us to think that this digestive segment is a homeostatic organ. The intestine is composed of an absorbant epithelium including enterocytic cells, myocytes, and cells containing zymogenic granules. As much as 90% of ingested protein matter occurs in a water-soluble state (half of it free amino acids, principally glycine) immediately on passing through the anterior part of the gut lumen. In the hindgut, solid faeces are mostly composed of elemental sulfur and are glycine depleted, making them good candidates to form the bulk of the suspended particles found in the waters closely surrounding the worm colonies. The whole gut content contains a high concentration of elemental sulfur. The digestive process of the worm is discussed.

Sign in / Sign up

Export Citation Format

Share Document