scholarly journals Analysis of structure-forming role of phosphogypsum in the production of nonfired cementless building composites

2020 ◽  
Vol 315 ◽  
pp. 07001
Author(s):  
Olga Kukina ◽  
Andrey Eremin ◽  
Dmitriy Shuvaev
Keyword(s):  
Building Materials ◽  
Test System ◽  
Chemical Plant ◽  
Simultaneous Increase ◽  
Aggregative Stability ◽  
Scanning Calorimetry ◽  
Water Films ◽  
Structure Density ◽  
Monolithic Structure

The working hypothesis is the development of the theory of disperse system aggregative stability considering the condensation processes of structure-forming of nonfired cementless building materials on the basis of phosphogypsum. The results of phisicomechanical and physicochemical analyses of Uvarovo chemical plant phosphogypsum are presented. To define the properties of phosphogypsum and phosphogypsum-based composite modern methods of analysis were applied with the use of the following equipment: the universal electromechanical test system Instron, the automatic diffractometer PANalytical EMPYREAN, the device for synchronic thermal analysis. The results of the research showed that the first endoeffects of Uvarovo chemical plant phosphogypsum have the dehydration energy of more than 200 joule/g, and they do not get lost within the time; this proves of the cementing properties of phosphogypsum. Due to the analysis of the differential scanning calorimetry results of phosphogypsum, pressed at 5 Mpa, it was found out that at the models compression the dehydration energy increases, and the correlation between the changes of water films’ thickness and dehydration energy can be observed. With the decrease of water films’ thickness we can observe the increase of dehydration energy with the simultaneous increase of the structure density and its transformation into a monolithic structure.

scholarly journals THE RESEARCH OF THE STRUCTURE FORMATION PROCESSES OF DISPERSE MATERIALS AT THE OBTAINING OF THE COMPOSITE BUILDING MATERIALS WITH PREDETERMINED PROPERTIES

2017 ◽  
Vol 21 (5) ◽  
pp. 93-106
Author(s):  
S. N. Zolotuhin ◽  
O. B. Kukina ◽  
A. A. Abramenko ◽  
V. JA. Mishhenko ◽  
A. A. Gapeev ◽  
...  
Keyword(s):  
Structure Formation ◽  
Building Materials ◽  
Sandy Loam ◽  
Low Cost ◽  
Microscopic Analysis ◽  
Scanning Calorimetry ◽  
Thermal Methods ◽  
Water Films ◽  
Technological Methods ◽  
Automatic Diffractometer

The basic concepts of the developed theory of the structure formation of dispersed materials in the preparation of composite building materials (CBM) with predetermined properties are proposed in the article. It is shown that, in addition to laborious methods of mathematical planning, low-cost research methods, for example, thermal methods, can be used to predict the properties of CBM. The data of differential scanning calorimetry, microscopic analysis, confirming the hypothesis that the thicknesses of water films on the surface of particles of disperse systems affect the formation of nano- and microstructures of CBM are presented. On the basis of VSTU in the center of collective use of the name of Professor Yu.M. Borisov conducted a number of tests on instruments of various domestic and foreign manufacturers, such as the RAULIKD derivative, the automatic diffractometer PANalytical EMPYREAN, the X-ray diffractometer DRON-2 and others using laser diffraction, synchronous thermal analysis. On the basis of the conducted experiments, the following conclusions were made: the IPFM systems with a phosphogypsum dihydrate content of 50 ... 60%, 10% lime, sandy loam 40 ... 30% possess the best physical-mechanical properties, water absorption and softening coefficients; drying at temperatures of 60 ... 65 ° C of the obtained materials leads to a decrease in the thickness of the water films between the particles and promotes further strength growth; an understanding of the mechanism of the effect of the thickness of aqueous films on the processes of the formation of hydrate hydrophilic systems allows us to predict that various technological methods leading to a reduction in their thickness will lead to an increase in the strength and other indices of materials obtained from non-flammable technologies.

The Diagnosis of Lupus Anticoagulants by the Activated Partial Thromboplastin Time - The Central Role of Phosphatidyl Serine

1984 ◽  
Vol 52 (02) ◽  
pp. 172-175 ◽  
Author(s):  
P R Kelsey ◽  
K J Stevenson ◽  
L Poller
Keyword(s):  
Screening Method ◽  
Coagulation Factors ◽  
Phosphatidyl Serine ◽  
Test System ◽  
Specific Factor ◽  
Marginal Effect ◽  
Constant Composition ◽  
Lupus Anticoagulants ◽  
Different Types

SummaryLiposomes of pure phospholipids were used in a modified APTT test system and the role of phosphatidyl serine (PS) in determining the sensitivity of the test system to the presence of lupus anticoagulants was assessed. Six consecutive patients with lupus anticoagulants and seven haemophiliacs with anticoagulants directed at specific coagulation factors, were studied. Increasing the concentration of phospholipid in the test system markedly reduced the sensitivity to lupus anticoagulants but had marginal effect on the specific factor inhibitors. The same effect was achieved when the content of PS alone was increased in a vehicle liposome of constant composition.The results suggest that the lupus anticoagulants can best be detected by a screening method using an APTT test with a reagent of low PS content. The use of a reagent rich in PS will largely abolish the lupus anticoagulant’s effect on the APTT. An approach using the two different types of reagent may facilitate differentiation of lupus inhibitors from other types of anticoagulant.

scholarly journals Effect of tungsten disulfide nanotubes on crystallization of polylactide under uniaxial deformation and annealing

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Fausta Loffredo ◽  
Loredana Tammaro ◽  
Tiziana Di Luccio ◽  
Carmela Borriello ◽  
Fulvia Villani ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Structural Evolution ◽  
Tungsten Disulfide ◽  
Fine Tuning ◽  
Nanocomposite Films ◽  
Uniaxial Deformation ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering

AbstractTungsten disulfide (WS2) nanotubes (NTs) are examined here as a filler for polylactide (PLA) for their ability to accelerate PLA crystallization and for their promising biocompatibility in relevant to biomedical applications of PLA-WS2 nanocomposites. In this work, we have studied the structural and thermal properties of PLA-WS2 nanocomposite films varying the concentration of WS2 NTs from 0 (neat PLA) to 0.6 wt%. The films were uniaxially drawn at 90 °C and annealed at the same temperature for 3 and 10 min. Using wide angle x-ray scattering, Raman spectroscopy and differential scanning calorimetry, we probed the effects of WS2 NT addition on the structure of the PLA films at various stages of processing (unstretched, stretching, annealing). We found that 0.6 wt% of WS2 induces the same level of crystallinity in as stretched PLA-WS2 as annealing in neat PLA for 10 min. These data provide useful insights into the role of WS2 NTs on the structural evolution of PLA-WS2 composites under uniaxial deformation, and extend their applicability to situations where fine tuning of PLA crystallinity is desirable.

INFLUENCE OF La2O3 ADDITIONS ON CHEMICAL DURABILITY AND DIELECTRIC PROPERTIES OF BOROALUMINOSILICATE GLASSES

2012 ◽  
Vol 19 (06) ◽  
pp. 1250062 ◽  
Author(s):  
X. H. ZHANG ◽  
Y. L. YUE ◽  
H. T. WU
Keyword(s):  
Dielectric Properties ◽  
Chemical Durability ◽  
Tangent Loss ◽  
Frequency Range ◽  
Scanning Calorimetry ◽  
Glass Transition Temperatures ◽  
Weight Losses ◽  
Quenching Method ◽  
Scanning Electron

Boroaluminosilicate glasses containing La2O3 were prepared by the normal quenching method. The glass transition temperatures (Tg) were measured by differential scanning calorimetry (DSC). The structural role of RO was investigated by nuclear magnetic resonance (NMR). Chemical durability was evaluated by weight losses of glass samples after immersion in HC1 solution. High resolution scanning electron microscopy (HR-SEM) was used to examine the surface micrographs of corroded glass samples. The dielectric constant and tangent loss were measured in the frequency range 10–106 Hz. The results revealed that chemical durability and dielectric properties increased with increasing La2O3 content.

Anti-fouling nano-Ag/SiO2 ormosil treatments for building materials: The role of cell-surface interactions on toxicity and bioreceptivity

2021 ◽  
Vol 153 ◽  
pp. 106120
Author(s):  
Marcia Domínguez ◽  
Rafael Zarzuela ◽  
Ignacio Moreno-Garrido ◽  
María Carbú ◽  
Jesús M. Cantoral ◽  
...  
Keyword(s):  
Cell Surface ◽  
Building Materials ◽  
Surface Interactions ◽  
Cell Surface Interactions

scholarly journals Role of Surfactants in the Properties of Poly(Ethylene Terephthalate)/Purified Clay Nanocomposites

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1397 ◽  
Author(s):  
Elaine dos Santos ◽  
Marcus Fook ◽  
Oscar Malta ◽  
Suédina de Lima Silva ◽  
Itamara Leite
Keyword(s):  
Clay Nanocomposites ◽  
Phosphonium Salts ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Alkyl Ammonium ◽  
Pet Crystallization

Purified clay was modified with different amounts of alkyl ammonium and phosphonium salts and used as filler in the preparation of PET nanocomposites via melt intercalation. The effect of this type of filler on morphology and thermal and mechanical properties of PET nanocomposites was investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analyses (TG), tensile properties, and transmission electron microscopy (TEM). The results showed that the mixture of alkyl ammonium and phosphonium salts favored the production of PET nanocomposites with intercalated and partially exfoliated morphologies with slight improvement in thermal stability. In addition, the incorporation of these organoclays tended to inhibit PET crystallization behavior, which is profitable in the production of transparent bottles.

scholarly journals Analysis of Strengthening the Application of External Wall Insulation Materials in Green Building Energy Saving Project

2020 ◽  
Vol 3 (2) ◽  
pp. 32
Author(s):  
Wenxin Luo
Keyword(s):  
Energy Saving ◽  
Construction Industry ◽  
Urban Areas ◽  
Building Materials ◽  
Green Building ◽  
Green Buildings ◽  
Exterior Wall ◽  
Insulation Materials ◽  
Environment Quality

<p>For the development and progress direction of contemporary construction industry, greening has always been one of the most important topics, which is basically consistent with China’s guidelines on environmental protection and resource conservation, with emphasis on whether it can effectively improve the ecological environment quality in urban areas, control various hazards caused by pollution, and build a healthy urban environment for people. Nowadays, the building materials market has also developed in an all-round way, and the types of materials for exterior wall insulation are also increasing. Relatively, the practical application difficulty of various technologies in the construction industry also shows an increasing trend. In order to better highlight the important role of insulation materials for green buildings, this paper will explore the application of exterior wall insulation materials with strong energy saving in green buildings.</p>

Bulk Breakdown in AlGaN/GaN HFETs

1998 ◽  
Vol 512 ◽  
Author(s):  
G. Gradinaru ◽  
N. C. Kao ◽  
R. Gaska ◽  
J. Yang ◽  
Q. Chen ◽  
...  
Keyword(s):  
Light Emission ◽  
Large Range ◽  
Simultaneous Increase ◽  
Gate Current ◽  
Emission Signal ◽  
Multiplication Process ◽  
Breakdown Mechanism ◽  
Carrier Multiplication ◽  
Source Current

ABSTRACTA significant source current generated by a carrier multiplication process is observed at large drain voltages in the subthreshold regime, along with simultaneous increase of the gate current and light emission signal. Provided no on-surface premature breakdown takes place, a bulk channel avalanche breakdown process is proposed as the dominant breakdown mechanism for a large range of gate-to-source dc voltages. This process in the GaN channel is responsible for the excess source and drain currents, light emission, and excess gate current beyond its normal value measured in a gate-to-drain diode configuration. The role of the gate bias in controlling the channel vs. the gate breakdown mechanisms is described.

Sign in / Sign up

Export Citation Format

Share Document