scholarly journals Purity and structural composition of lignin isolated from Miscanthus x giganteus by sub-critical water extraction with associated modifiers

2020 ◽  
Vol 1 (1) ◽  
pp. 1-12 ◽  
Keyword(s):  
Paper Industry ◽  
Chemical Properties ◽  
Value Added ◽  
Hydroxyl Groups ◽  
Physical And Chemical Properties ◽  
Miscanthus X Giganteus ◽  
Lignin Recovery ◽  
Physical And Chemical ◽  
The Impact ◽  
And Chemical Properties

Lignin is an industrial by-product produced from the pulping and paper industry, where the process generates lignin in the form of lignosulphonates. While there are many applications for lignin, there are all low value and attempts to add value to lignin are hindered by its complex physicochemical nature and the presence of sulphur. Adopting the biorefining concept, the study evaluates the impact of direct (DE) and sequential extraction (SE) of Miscanthus x giganteus using sub-critical water with associated modifiers; ethanol and carbon dioxide on the physical and chemical properties of the extracted lignin. Isolated lignins were characterised by a Fourier Transform Infrared Spectroscopy (FTIR). Although higher delignification was achieved by DE and SE about 81.5% and 58.0%, respectively, the lignin recovered from the SE process showed remarkably higher purity with 91.5%. Lignin recovery did not differ considerably for either processing method. FTIR revealed a qualitative reduction in the intensity of bonds corresponding to hydroxyl groups for the lignin derived from DE rather than SE processing routes. These indicated that the lignin derived from SE had potential for subsequent preparation in lignin value-added bio-based materials.

scholarly journals The Interstellar Medium of Dwarf Galaxies

Galaxies ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Christian Henkel ◽  
Leslie K. Hunt ◽  
Yuri I. Izotov
Keyword(s):  
Interstellar Medium ◽  
Dwarf Galaxies ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Ionized Gas ◽  
Green Pea ◽  
Physical And Chemical ◽  
The Impact ◽  
The Universe ◽  
And Chemical Properties

Dwarf galaxies are by far the most numerous galaxies in the Universe, showing properties that are quite different from those of their larger and more luminous cousins. This review focuses on the physical and chemical properties of the interstellar medium of those dwarfs that are known to host significant amounts of gas and dust. The neutral and ionized gas components and the impact of the dust will be discussed, as well as first indications for the existence of active nuclei in these sources. Cosmological implications are also addressed, considering the primordial helium abundance and the similarity of local Green Pea galaxies with young, sometimes protogalactic sources in the early Universe.

scholarly journals An Overview of Dynamic Heterogeneous Oxidations in the Troposphere

Environments ◽  
2018 ◽  
Vol 5 (9) ◽  
pp. 104 ◽  
Author(s):  
Elizabeth Pillar-Little ◽  
Marcelo Guzman
Keyword(s):  
Atmospheric Aerosols ◽  
Atmospheric Transport ◽  
Cloud Condensation Nuclei ◽  
Complex Mixture ◽  
Organic Aerosols ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
The Impact ◽  
And Chemical Properties

Due to the adverse effect of atmospheric aerosols on public health and their ability to affect climate, extensive research has been undertaken in recent decades to understand their sources and sinks, as well as to study their physical and chemical properties. Atmospheric aerosols are important players in the Earth’s radiative budget, affecting incoming and outgoing solar radiation through absorption and scattering by direct and indirect means. While the cooling properties of pure inorganic aerosols are relatively well understood, the impact of organic aerosols on the radiative budget is unclear. Additionally, organic aerosols are transformed through chemical reactions during atmospheric transport. The resulting complex mixture of organic aerosol has variable physical and chemical properties that contribute further to the uncertainty of these species modifying the radiative budget. Correlations between oxidative processing and increased absorptivity, hygroscopicity, and cloud condensation nuclei activity have been observed, but the mechanisms behind these phenomena have remained unexplored. Herein, we review environmentally relevant heterogeneous mechanisms occurring on interfaces that contribute to the processing of aerosols. Recent laboratory studies exploring processes at the aerosol–air interface are highlighted as capable of generating the complexity observed in the environment. Furthermore, a variety of laboratory methods developed specifically to study these processes under environmentally relevant conditions are introduced. Remarkably, the heterogeneous mechanisms presented might neither be feasible in the gas phase nor in the bulk particle phase of aerosols at the fast rates enabled on interfaces. In conclusion, these surface mechanisms are important to better understand how organic aerosols are transformed in the atmosphere affecting the environment.

scholarly journals MgO Refractory Doped with ZrO2 Nanoparticles: Influence of Cold Isostatic and Uniaxial Pressing and Sintering Temperature in the Physical and Chemical Properties

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1297 ◽  
Author(s):  
Cristian Gómez-Rodríguez ◽  
Daniel Fernández-González ◽  
Linda Viviana García-Quiñonez ◽  
Guadalupe Alan Castillo-Rodríguez ◽  
Josué Amilcar Aguilar-Martínez ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Cold Isostatic Pressing ◽  
Zro2 Nanoparticles ◽  
Furnace Lining ◽  
Physical And Chemical Properties ◽  
X Ray ◽  
Isostatic Pressing ◽  
Physical And Chemical ◽  
The Impact ◽  
And Chemical Properties

The chemical environment and the internal conditions of the furnaces and ladles are extremely aggressive for the refractories, so metallurgical industries demand refractory linings with greater durability and resistance to avoid unforeseen stoppages and to reduce the changes of the furnace lining. Therefore, the current work aims to evaluate the impact of the additions of ZrO2-nanoparticles (1, 3, and 5 wt. %) in magnesia-based bricks. A comparative study of the physical and chemical properties in bricks obtained using two cold pressing techniques (uniaxial and isostatic pressing) and two sintering temperatures (1550 and 1650 °C) was carried out. The microstructure and crystalline phase characteristics obtained after the heat treatments and the slag corrosion test was studied using scanning electron microscopy/electron dispersive X-ray spectroscopy (SEM/EDX) and X-ray diffraction (XRD). The results reveal that the sample with 5 wt. % of ZrO2 nanoparticles (obtained by cold isostatic pressing and sintering at 1650 °C) has the lowest porosity and greatest resistance to penetration of blast furnace slag.

scholarly journals The kinetic parameters of aerosols formed during combustion of modified wood

2018 ◽  
Vol 251 ◽  
pp. 02023
Author(s):  
Feodor Portnov
Keyword(s):  
Grain Size ◽  
Surface Layer ◽  
Chemical Properties ◽  
Quantitative Composition ◽  
Kinetic Properties ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
The Impact ◽  
And Chemical Properties ◽  
Modified Wood

The paper studies kinetic properties of aerosols formed in thermal degradation of wood. The impact of modifying agents in wood surface layer on the quantitative composition of smoke aerosol solids was analyzed. For this purpose, grain-size of aerosol solids was analyzed, and the physical and chemical properties of source and modified wood were assessed.

Status of the utilization of jack pine (Pinusbanksiana) in the pulp and paper industry

1994 ◽  
Vol 24 (10) ◽  
pp. 2078-2084 ◽  
Author(s):  
Kwei-Nam Law ◽  
Jacques L. Valade
Keyword(s):  
Paper Industry ◽  
Chemical Properties ◽  
Pulp And Paper Industry ◽  
Jack Pine ◽  
Chemical Processes ◽  
Future Research ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
Potential Use ◽  
And Chemical Properties

Although jack pine (Pinusbanksiana Lamb.), which represents 20% of the total softwood volume, is one of the most abundant commercial softwood species in Canada, its rate of utilization in pulping is surprisingly low. This paper reviews the literature concerning the physical and chemical properties as well as the pulping characteristics of this species by mechanical, thermomechanical, chemithermomechanical, chemimechanical, and chemical processes to better understand its potential use in papermaking. The objective is to identify the problems related to the use of jack pine so that solutions might be sought to promote its usage. Some recommendations are put forth concerning future research.

scholarly journals ANALYSİS OF THE İMPACT OF PHYSİCAL AND CHEMİCAL FEATURES OF THE NATURAL GAS TO THE PARAMETERS OF THE GAS TRANSPORT SYSTEM

2021 ◽  
Vol 11 (07) ◽  
pp. 22-28
Author(s):  
H.R.Gurbanov H.R.Gurbanov ◽  
A.N. Baghirov A.N. Baghirov
Keyword(s):  
Natural Gas ◽  
Chemical Properties ◽  
Specific Weight ◽  
Transportation System ◽  
Physical And Chemical Properties ◽  
Compressor Station ◽  
Associated Gas ◽  
Physical And Chemical ◽  
The Impact ◽  
And Chemical Properties

Definition of the technological regimes of the natural gas transportation system is co-related with the physical and chemical features of the gas. The results of the chemical analyses of gas in the gas turbine compressor station are laid out in the article: various levels of changes of the composition of gas at various points are described. Technological losses of gas are determined, as the result of change in its specific weight in the process of compression, cooling down and separation at the compressor station. Gas losses in the sub water main gas pipelines are analyzed. Changes of the content of the gas carbonate in the composition of the gas are analyzed, its degradation alongside the pipeline and existence of the CO2 in the composition of the low-pressure oil associated gas is described in comparison with the high-pressure natural gas, which is 3,8 times more. The problems, caused by the presence of the gas carbonate in the composition of the natural gas, are highlighted. The physical properties of natural gas are characterized by its specific gravity, temperature, pressure, volume and other parameters, and chemical properties by its composition, stability of gas-forming components. It should be noted that the physical and chemical properties of gas vary within certain limits, depending on the time, both on the reservoir and on the same reservoir. Therefore, in order to regulate the parameters of the gas transportation system, it is necessary to periodically examine and take into account the physical and chemical properties of the gas. Keywords: Natural gas, carbon dioxide,compressor station, gas pipeline, gas well.

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