scholarly journals Mechanistic Approach to Thermal Production of New Materials from Asphaltenes of Castilla Crude Oil

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1644
Author(s):  
Natalia Afanasjeva ◽  
Andrea González-Córdoba ◽  
Manuel Palencia
Keyword(s):  
Crude Oil ◽  
Structural Changes ◽  
Gas Chromatography Mass Spectrometry ◽  
New Materials ◽  
Gaseous Products ◽  
Chemical Structures ◽  
Mechanistic Approach ◽  
Before And After ◽  
Liquid Products ◽  
Average Size

Asphaltenes are compounds present in crude oils that influence their rheology, raising problems related to the extraction, transport, and refining. This work centered on the chemical and structural changes of the asphaltenes from the heavy Colombian Castilla crude oil during pyrolysis between 330 and 450 °C. Also, the development of new strategies to apply these macromolecules, and the possible use of the cracking products as a source of new materials were analyzed. The obtained products (coke, liquid, and gas) were collected and evaluated through the techniques of proton and carbon-13 nuclear magnetic resonance (1H and 13C NMR), elemental composition, Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), saturates, aromatics, resins, and asphaltenes (SARA) analysis, and gas chromatography–mass spectrometry (GC-MS). A comparison of the applied methods showed that the asphaltene molecules increased the average size of their aromatic sheets, lost their aliphatic chains, condensed their aromatic groups, and increased their degree of unsaturation during pyrolysis. In the liquid products were identified alkylbenzenes, n-alkanes C9–C30, and n-alkenes. Moreover, the gaseous products included methane, ethane, propane, and pentane. An approach of the structural chain reaction was used to define the possible asphaltenes chemical structures before and after pyrolysis. In conclusion, this type of thermal process can be used as an easy route to attain new materials associated with specific structural units from the asphaltenes.

scholarly journals Competition in a Wholesale Fuel Market—The Impact of the Structural Changes Caused by COVID-19

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4211
Author(s):  
Sylwester Bejger
Keyword(s):  
Crude Oil ◽  
Structural Changes ◽  
Consumer Surplus ◽  
Global Market ◽  
Liquid Fuels ◽  
Wholesale Market ◽  
Potential Market ◽  
Before And After ◽  
Energy Products ◽  
The Impact

Liquid fuels obtained in refining crude oil are one of the most important energies in economic activity. The domestic wholesale market for liquid fuels is of decisive importance for price formation in the national economy. The noncompetitive behavior of the market players at this level of the distribution chain can significantly affect all downstream price levels and the producer–consumer surplus balance. Therefore, the competitiveness of this market should be screened and assessed regularly, especially when significant external factors change. This article attempts to evaluate the impact of structural changes on the global market of crude oil and energy products after the outbreak of the COVID-19 pandemic on the competitiveness of the wholesale fuel market in Poland. Using asymmetry of the reaction of product prices to changes in the prices of inputs as a marker of noncompetitive behavior and the NARDL model as a test specification, the price paths of market players before and after the occurrence of structural changes in the inputs’ processes were examined. Significant changes in the competitive behavior of players were revealed after the occurrence of structural changes at the beginning of the pandemic period in the year 2020. These changes may indicate enhanced competition and mitigation of potential market power abuse.

scholarly journals Pyrolysis of Table Sugar

2013 ◽  
Vol 2013 ◽  
pp. 1-3
Author(s):  
Adnan Bulut ◽  
Selhan Karagöz
Keyword(s):  
Pyrolysis Temperature ◽  
Relative Concentration ◽  
Fixed Bed ◽  
Liquid Product ◽  
Fixed Bed Reactor ◽  
Gas Chromatography Mass Spectrometry ◽  
Gaseous Products ◽  
Hydroxymethyl Furfural ◽  
Liquid Products ◽  
Different Temperatures

Table sugars were pyrolyzed at different temperatures (300, 400, and 500°C) in a fixed-bed reactor. The effect of pyrolysis temperature on yields of liquid, solid, and gaseous products was investigated. As expected the yield of liquid products gradually increased and the yield of solid products gradually decreased when the pyrolysis temperature was raised. The yield of liquid products was greatest (52 wt%) at 500°C. The composition of bio-oils extracted with diethyl ether was identified by means of gas chromatography mass spectrometry (GC-MS), nuclear magnetic resonance (1H-NMR), and Fourier transform infrared spectroscopy (FTIR). The following compounds were observed in bio-oils produced from the pyrolysis of table sugar at 500°C: 1,4:3,6-dianhydro-α-d-glucopyranose, 5-(hydroxymethyl) furfural, 5-acetoxymethyl-2-furaldehyde, and cyclotetradecane liquid product. The relative concentration of 5-(hydroxymethyl) furfural was the highest in bio-oils obtained from pyrolysis of table sugars at 500°C.

scholarly journals Study on Microstructure Characteristics of Clay Rock of Xigeda Formation in Xichang City Based on Softening Test and Image Recognition

2021 ◽  
Author(s):  
Zheng Yang ◽  
Ning Guo ◽  
Heng Zhang
Keyword(s):  
Image Recognition ◽  
Structural Changes ◽  
Water Saturation ◽  
Clay Rock ◽  
Water Softening ◽  
Before And After ◽  
Fine Clay ◽  
Size Of Particles ◽  
Average Size ◽  
Aggregate Particles

Based on the Xigeda clay rock exposed in the back mountain of Nanshan Villa in Xichang City, the microstructure changes of Xigeda clay rock before and after water softening were studied by scanning electron microscope and image recognition of PCAS software. The results show that: (1) the clay rock of Xigeda group has flake and layered micro structural characteristics, and the surface of aggregates in natural state has honeycomb characteristics. After water softening, the aggregate particles decompose, the average size of particles becomes smaller, the honeycomb characteristics disappear, and the surface contours of particles become smooth and round. (2) With the increase of water saturation time, the number of aggregate particles and pores increases, the porosity decreases in advance and increases in the later stage. (3) Micro structural changes of the clay rock in Xigeda formation have two stages, in the first stage, the aggregates decompose and the produced fine granular clays fill the original pores, resulting in the decrease of porosity.In the second stage, the fine clay particles further soften, decompose and lose in the water, the porosity increases suddenly.

scholarly journals Hydrogenolysis of lignin in ZnCl2 and KCl as an inorganic molten salt medium

Holzforschung ◽  
2015 ◽  
Vol 69 (5) ◽  
pp. 523-529
Author(s):  
Jörn Appelt ◽  
Anne Gohrbandt ◽  
Jana Peters ◽  
Martina Bremer ◽  
Steffen Fischer
Keyword(s):  
Molten Salt ◽  
Residence Time ◽  
Reaction Temperature ◽  
Eutectic Mixture ◽  
Gas Chromatography Mass Spectrometry ◽  
Lignin Concentration ◽  
Gaseous Products ◽  
Organosolv Lignin ◽  
Liquid Products ◽  
Secondary Reactions

Abstract Lignin can be converted into monomeric products with the aid of molten salt media. Molten zinc chloride (ZnCl2)/potassium chloride (KCl) mixtures are suitable for this purpose. The application of an eutectic mixture with low melting points leads to similar main products as are obtained by pyrolysis. The hydrogenolysis of an organosolv lignin in molten salts of ZnCl2/KCl was investigated as a function of reaction temperature, residence time, and lignin concentration, and the composition of liquid products and monophenols was analyzed by gas chromatography-mass spectrometry (GC-MS). The yields can be optimized by the proper selection of the reaction temperature. A longer residence time and higher lignin concentrations lead to increased formation of solid residues and gaseous products. The liquid products mainly consist of substituted phenols derived from lignins. Polymeric products are the result of condensation reactions (i.e., the formation of new C-C linkages in the course of secondary reactions).

An Empirical Investigation of Factors Affecting Stock Prices in Vietnam

2014 ◽  
pp. 74-89 ◽  
Author(s):  
Vinh Vo Xuan
Keyword(s):  
Exchange Rates ◽  
Crude Oil ◽  
Foreign Exchange ◽  
Stock Prices ◽  
Global Financial Crisis ◽  
Oil Prices ◽  
Foreign Exchange Rates ◽  
Factors Affecting ◽  
Crude Oil Prices ◽  
Before And After

This paper investigates factors affecting Vietnam’s stock prices including US stock prices, foreign exchange rates, gold prices and crude oil prices. Using the daily data from 2005 to 2012, the results indicate that Vietnam’s stock prices are influenced by crude oil prices. In addition, Vietnam’s stock prices are also affected significantly by US stock prices, and foreign exchange rates over the period before the 2008 Global Financial Crisis. There is evidence that Vietnam’s stock prices are highly correlated with US stock prices, foreign exchange rates and gold prices for the same period. Furthermore, Vietnam’s stock prices were cointegrated with US stock prices both before and after the crisis, and with foreign exchange rates, gold prices and crude oil prices only during and after the crisis.

Study of the Kinetics of Thermal Destruction of Crossed Polyethylene

2019 ◽  
Vol 5 (12) ◽  
pp. 37-46
Author(s):  
K. Chalov ◽  
Yu. Lugovoy ◽  
Yu. Kosivtsov ◽  
E. Sulman
Keyword(s):  
Total Yield ◽  
Calorific Value ◽  
High Heat ◽  
Process Temperature ◽  
Optimum Process ◽  
Quantitative Composition ◽  
Pyrolysis Gas ◽  
Gaseous Products ◽  
Liquid Products ◽  
Kinetics Of

This paper presents a study of the process of thermal degradation of crosslinked polyethylene. The kinetics of polymer decomposition was studied by thermogravimetry. Crosslinked polyethylene showed high heat resistance to temperatures of 400 °C. The temperature range of 430–500 °C was determined for the loss of the bulk of the sample. According to thermogravimetric data, the decomposition process proceeds in a single stage and includes a large number of fracture, cyclization, dehydrogenation, and other reactions. The process of pyrolysis of a crosslinked polymer in a stationary-bed metal reactor was investigated. The influence of the process temperature on the yield of solid, liquid, and gaseous pyrolysis products was investigated. The optimum process temperature was 500 °C. At this temperature, the yield of liquid and gaseous products was 85.0 and 12.5% (mass.), Respectively. Samples of crosslinked polyester decomposed almost completely. The amount of carbon–containing residue was 3.5% by weight of the feedstock. With increasing temperature, the yield of liquid products decreased slightly and the yield of gaseous products increased, but their total yield did not increase. For gaseous products, a qualitative and quantitative composition was determined. The main components of the pyrolysis gas were hydrocarbons C1–C4. The calorific value of pyrolysis gas obtained at a temperature of 500 °C was 17 MJ/m3. Thus, the pyrolysis process can be used to process crosslinked polyethylene wastes to produce liquid hydrocarbons and combustible gases.

Dynamic Relationship between Crude Oil and Stock Prices in India: Before And After the Subprime Financial Crisis 2008

GIS Business ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. 96-104
Author(s):  
P. Sakthivel ◽  
S. Rajaswaminathan ◽  
R. Renuka ◽  
N. R.Vembu
Keyword(s):  
Financial Crisis ◽  
Crude Oil ◽  
Stock Prices ◽  
Oil Prices ◽  
Energy Index ◽  
Data Set ◽  
Dynamic Relationship ◽  
Crude Oil Prices ◽  
Long Run ◽  
Before And After

This paper empirically discovered the inter-linkages between stock and crude oil prices before and after the subprime financial crisis 2008 by using Johansan co-integration and Granger causality techniques to explore both long and short- run relationships.  The whole data set of Nifty index, Nifty energy index, BSE Sensex, BSE energy index and oil prices are divided into two periods; before crisis (from February 15, 2005 to December31, 2007) and after crisis (from January 1, 2008 to December 31, 2018) are collected and analyzed. The results discovered that there is one-way causal relationship from crude oil prices to Nifty index, Nifty energy index, BSE Sensex and BSE energy index but not other way around in both periods. However, a bidirectional causality relationship between BSE Energy index and crude oil prices during post subprime financial crisis 2008. The co-integration results suggested that the absence of long run relationship between crude oil prices and market indices of BSE Sensex, BSE energy index, Nifty index and Nifty energy index before and after subprime financial crisis 2008.

A pilot study on the effect of ulipristal acetate on myoma angiogenesis, measured by 2D ultrasound and VEGF serum levels

2020 ◽  
pp. 19-29
Author(s):  
Patricia Diaz Ortega ◽  
Manuel García Manero
Keyword(s):  
Pilot Study ◽  
Power Doppler ◽  
Uterine Fibroids ◽  
Premenopausal Women ◽  
Serum Levels ◽  
Ulipristal Acetate ◽  
Before And After ◽  
Angiogenesis Process ◽  
2D Ultrasound ◽  
Average Size

Introduction: Symptomatic uterine fibroids can cause symptoms that can be disabling. There are many treatments, including ulipristal acetate, whose role in reducing symptoms and decreasing the size of the fibroid is well known. With this preliminary study, we also try to evaluate the correlation between myoma vascularization measured by ultrasound (Power Doppler 2D) and serum VEGF levels, before and after treatment with ulipristal acetate; in patients diagnosed with symptomatic uterine fibroids. Materials and Methods: A preliminary, prospective observational pilot study was designed. Twenty-four premenopausal women, diagnosed with symptomatic uterine fibroids, were included and all of them completed the study. Four cycles of ulipristal acetate were administered according to the dose and indications specified in the data sheet. In order to assess the influence of this treatment on the angiogenesis process of the fibroids, measurements of VEGF serum levels were made and their vascularization was assessed by means of 2D power doppler ultrasound; at the beginning and the end of treatment. In addition, several determinations of the same parameters were made throughout the successive visits. Endpoints were defined as the decrease in VEGF levels from previous levels, the decrease in myoma vascularization on ultrasound, and the reduction in myoma size. Result: 24 patients who met the inclusion criteria were enrolled (n=24). The average size of myomas was reduced from 45,08 ? 24,02mm to 29?16,96mm after treatment. The average VEGF serum level significantly decreased after the first treatment cycle (from 147,17 ? 153,51 pg/ml to 102,04 ? 186,08pg/ml). Vascularization of myomas after treatment with ulipristal acetate was analyzed, and a significantly decrease was achieved in 83,3% of cases. Conclusion: There is a correlation between myoma vascularization and treatment with Ulipristal acetate. SPRMs may provide effective treatment for women with symptomatic fibroids by two ways: supports selective progesterone receptor modulators and reduced angiogenesis. Keywords: Angiogenesis; Ulipristal Acetate; Uterine fibroids; VEGF

Short Review and opinion: New matter properties and applications based on Hybrids Graphene based Metamaterials

2020 ◽  
Vol 04 ◽  
Author(s):  
A. Guillermo Bracamonte
Keyword(s):  
Short Review ◽  
New Materials ◽  
Design And Synthesis ◽  
Chemical Structures ◽  
Current State ◽  
Potential Applications ◽  
Fundamental Research ◽  
Miniaturized Instrumentation ◽  
And Control ◽  
Conductive Properties

: Graphene as Organic material showed special attention due to their electronic and conductive properties. Moreover, its highly conjugated chemical structures and relative easy modification permitted varied design and control of targeted properties and applications. In addition, this Nanomaterial accompanied with pseudo Electromagnetic fields permitted photonics, electronics and Quantum interactions with their surrounding that generated new materials properties. In this context, this short Review, intends to discuss many of these studies related with new materials based on graphene for light and electronic interactions, conductions, and new modes of non-classical light generation. It should be highlighted that these new materials and metamaterials are currently in progress. For this reason it was showed and discussed some representative examples from Fundamental Research with Potential Applications as well as for their incorporations to real Advanced devices and miniaturized instrumentation. In this way, it was proposed this Special issue entitled “Design and synthesis of Hybrids Graphene based Metamaterials”, in order to open and share the knowledge of the Current State of the Art in this Multidisciplinary field.

scholarly journals Holospiniferoside: A New Antitumor Cerebroside from The Red Sea Cucumber Holothuria spinifera: In Vitro and In Silico Studies

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1555
Author(s):  
Enas E. Eltamany ◽  
Usama Ramadan Abdelmohsen ◽  
Dina M. Hal ◽  
Amany K. Ibrahim ◽  
Hashim A. Hassanean ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Red Sea ◽  
Active Site ◽  
Sea Cucumber ◽  
Gas Chromatography Mass Spectrometry ◽  
Spectrometric Analysis ◽  
Chemical Structures ◽  
In Silico Studies ◽  
Red Sea Cucumber

Chemical investigation of the methanolic extract of the Red Sea cucumber Holothuria spinifera led to the isolation of a new cerebroside, holospiniferoside (1), together with thymidine (2), methyl-α-d-glucopyranoside (3), a new triacylglycerol (4), and cholesterol (5). Their chemical structures were established by NMR and mass spectrometric analysis, including gas chromatography–mass spectrometry (GC–MS) and high-resolution mass spectrometry (HRMS). All the isolated compounds are reported in this species for the first time. Moreover, compound 1 exhibited promising in vitro antiproliferative effect on the human breast cancer cell line (MCF-7) with IC50 of 20.6 µM compared to the IC50 of 15.3 µM for the drug cisplatin. To predict the possible mechanism underlying the cytotoxicity of compound 1, a docking study was performed to elucidate its binding interactions with the active site of the protein Mdm2–p53. Compound 1 displayed an apoptotic activity via strong interaction with the active site of the target protein. This study highlights the importance of marine natural products in the design of new anticancer agents.

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