Framework stabilization of Si-rich LTA zeolite prepared in organic-free media

2015 ◽  
Vol 51 (2) ◽  
pp. 269-272 ◽  
Author(s):  
Marlon T. Conato ◽  
Matthew D. Oleksiak ◽  
B. Peter McGrail ◽  
Radha K. Motkuri ◽  
Jeffrey D. Rimer
Keyword(s):  
Silica Content ◽  
Lta Zeolite ◽  
Free Media

Zeolite HOU-2 (LTA type) is prepared with the highest silica content (Si/Al = 2.1) reported for organic-free syntheses.

Effect of furnace atmosphere and silica content on the consolidation behaviour of magnesia partially stabilised zirconia

1990 ◽  
Vol 48 (4) ◽  
pp. 1056-1057
Author(s):  
J. Drennan ◽  
R.H.J. Hannink ◽  
D.R. Clarke ◽  
T.M. Shaw
Keyword(s):  
Liquid Phase ◽  
Silica Content ◽  
Liquid Phase Sintering ◽  
Furnace Atmosphere ◽  
Boundary Phase ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Series Of Experiments ◽  
Compositional Gradients ◽  
Mobile Liquid

Magnesia partially stabilised zirconia (Mg-PSZ) ceramics are renowned for their excellent nechanical properties. These are effected by processing conditions and purity of starting materials. It has been previously shown that small additions of strontia (SrO) have the effect of removing the major contaminant, silica (SiO2).The mechanism by which this occurs is not fully understood but the strontia appears to form a very mobile liquid phase at the grain boundaries. As the sintering reaches the final stages the liquid phase is expelled to the surface of the ceramic. A series of experiments, to examine the behaviour of the liquid grain boundary phase, were designed to produce compositional gradients across the ceramic bodies. To achieve this, changes in both silica content and furnace atmosphere were implemented. Analytical electron microscope techniques were used to monitor the form and composition of the phases developed. This paper describes the results of our investigation and the presentation will discuss the work with reference to liquid phase sintering of ceramics in general.

Release, Aggregation and Lysis of Human Platelets by Antilymphocyte Globulin and Antiplatelet Serum

1976 ◽  
Vol 36 (02) ◽  
pp. 411-423 ◽  
Author(s):  
Nicholas Lekas ◽  
J. C Rosenberg
Keyword(s):  
Platelet Aggregation ◽  
Gamma Globulin ◽  
Human Platelets ◽  
Plasma Medium ◽  
Release Reaction ◽  
Clinical Events ◽  
Thrombotic Complications ◽  
Platelet Release ◽  
Free Media

SummaryHuman platelets labeled with 51Cr were used to determine the contribution made by platelet lysis to the platelet release reaction and platelet aggregation induced by rabbit antihuman platelet serum (APS) and equine antihuman thymocyte globulin (ATG). Platelets were tested in both plasma (PRP) and non-plasma containing media. Antibodies directed against platelets, either as APS or ATG, induced significant amounts of platelet release and aggregation, as well as some degree of lysis, in the absence of complement. The presence of complement increased platelet lysis and aggregation, but not the release reaction. Non-immune horse gamma globulin produced different responses depending upon whether platelets were investigated in PRP or non-plasma containing media. Aggregation was seen in the latter but not the former. These differences can be explained by the presence of plasma components which prevent non-specific immune complexes from causing platelet aggregation. Since platelets in vivo are always in a plasma medium, one must be wary of utilizing data from platelet studies in synthetic plasma-free media as the basis of explaining clinical events. These observations demonstrate at least two, and possibly three, different mechanisms whereby ATG could activate platelets causing thrombotic complications and thrombocytopenia, i.e., via 1) specific and, 2) non-specific non-lytic pathways and 3) a lytic pathway.

DIVERSITY AND DISTRIBUTION OF ORIBATID MITE FAUNA(ACARI: ORIBATIDA) IN THE FOREST FLOOR OF SATKOSIA BASIPALLY WILD LIFE SANCTUARY, ODISHA, INDIA

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
SHELLEY ACHARYA ◽  
ADITI DUTTA
Keyword(s):  
Forest Floor ◽  
Dominant Species ◽  
Oribatid Mite ◽  
Soil Condition ◽  
Silica Content ◽  
Soil Mites ◽  
The Core ◽  
Humid Condition ◽  
Core Areas ◽  
Wild Life

The studies were mostly concentrated in Nine forest ranges of the WLS including the core areas. The soil of this region mostly is dry, red and with iron and silica content. Though the soil mites are prevalent in moist humid condition, we got a diversed population of 20 different species under 14 genera which is less than average probably due to the soil condition. Protoribates magnus is the dominant species in this study. The species with larger ranges were Scheloribates curvialatus.

Synthesis of ZnO/ZnFe2O4 nanocomposites in organic-free media and their photocatalytic activity under natural sunlight

2020 ◽  
Vol 14 (2) ◽  
pp. 6801-6810
Author(s):  
Rahmayeni Rahmayeni ◽  
Zulhadjri Zulhadjri ◽  
Yeni Stiadi ◽  
Agusnar Harry ◽  
Syukri Arief
Keyword(s):  
Electron Microscopy ◽  
Hexagonal Wurtzite Structure ◽  
Rice Grain ◽  
X Ray Diffraction ◽  
Homogeneous Sphere ◽  
Natural Sunlight ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Free Media ◽  
Photocatalytic Applications

Nanocomposite ZnO/ZnFe2O4 photocatalysts with different proportions of ZnFe2O4 were synthesized in organic-free media using metal nitric as precursors. The ZnO phase with hexagonal wurtzite structure and low crystallinity of ZnFe2O4 was confirmed using XRD (X-Ray diffraction). Different morphologies of the nanocomposites were obtained ranging from rice grain-like with a porous surface to homogeneous sphere-like nanoparticles as shown in Scanning Electron Microscopy (SEM) and TEM Transmission Electron Microscopy (TEM) studies. Magnetic properties measured by Visible Sampler Magnetometer (VSM) showed diamagnetic and paramagnetic behavior for the nanocomposites. Analysis with Diffuse Reflectance Spectrophotometer (DRS) UV-vis showed an increase the composition of ferrite in composites increasing its ability to absorb visible light. Photocatalytic activities of ZnO/ZnFe2O4 nanocomposites on the degradation of Rhodamine B dye reached 95.6% after 3 h under natural sunlight suggesting their suitability for sunlight driven photocatalytic applications. 

CONTRIBUTION TO THE EXISTENCE OF REGULATORY MECHANISMS AT THE ADRENAL LEVEL

1972 ◽  
Vol 70 (4) ◽  
pp. 741-757
Author(s):  
Otto Linèt
Keyword(s):  
Orotic Acid ◽  
Adrenal Glands ◽  
Actinomycin D ◽  
Delay Period ◽  
Regulatory Mechanisms ◽  
Leucine Incorporation ◽  
Total Period ◽  
Free Media

ABSTRACT Rat adrenal glands atrophied by the administration of cortisol acetate in vivo were used as a model for the study of early metabolic processes occurring in vitro. Atrophied adrenals incubated in the presence of 14C-leucine incorporated subnormal quantities of this amino acid per mg of protein for the first 120 min. When the incubation lasted for a total period of 180 or 240 min a supranormal rise in the 14C-leucine incorporation was observed. Similar changes occurred with some delay with regard to corticosterone production as expressed per 100 mg of tissue. No differences in 14C-leucine incorporation were observed between the control and atrophied adrenals in vivo. Homogenates from atrophied glands incorporated 14C-leucine to a greater extent than the control homogenates. The in vitro incorporation of 14C-orotic acid into the RNA was also higher in atrophied adrenals. The in vitro use of actinomycin D, cycloheximide and amphenone indicated that corticosterone production depended on the incorporation of 14C-leucine. The addition of cortisol to the incubation media markedly decreased the enhancement of 14C-lysine incorporation into the protein of atrophied adrenals. These, as well as additional results suggest rebound phenomena: once atrophic adrenals are transferred to cortisol-free media, reparative processes begin after a delay period. Such phenomena seem to be mediated by regulatory mechanisms at the adrenal level.

Effect of ornidazole on fertility of male rats: inhibition of a glycolysis-related motility pattern and zona binding required for fertilization in vitro

Reproduction ◽  
2000 ◽  
pp. 127-135 ◽  
Author(s):  
W Bone ◽  
NG Jones ◽  
G Kamp ◽  
CH Yeung ◽  
TG Cooper
Keyword(s):  
Zona Pellucida ◽  
Glucose Utilization ◽  
Cumulus Cells ◽  
Glycolytic Enzyme ◽  
Male Rats ◽  
Fertilization In Vitro ◽  
Swimming Pattern ◽  
Principal Piece ◽  
Free Media

The effects of the male antifertility agent ornidazole on glycolysis as a prerequisite for fertilization were investigated in rats. Antifertility doses of ornidazole inhibited glycolysis within mature spermatozoa as determined from the lack of glucose utilization, reduced acidosis under anaerobic conditions and reduced glycolytic enzyme activity. As a consequence, cauda epididymidal spermatozoa from ornidazole-fed rats were unable to fertilize rat oocytes in vitro, with or without cumulus cells, which was not due to transfer of an inhibitor in epididymal fluid with the spermatozoa. Under IVF conditions, binding to the zona pellucida was reduced in spermatozoa from ornidazole-fed males and the spermatozoa did not undergo a change in swimming pattern, which was observed in controls. The block to fertilization could be explained by the disruption of glycolysis-dependent events, since reduced binding to the zona pellucida and a lack of kinematic changes were demonstrated by control spermatozoa in glucose-free media in the presence of respiratory substrates. The importance of glycolysis for binding to, and penetration of, the zona pellucida, and hyperactivation in rats is discussed in relation to the glycolytic production of ATP in the principal piece in which local deprivation of energy may explain the reduced force of spermatozoa from ornidazole-fed males.

Processing of granite quarry solid waste into industrial high silica materials using leaching process with HCl concentration variation

2020 ◽  
Vol 11 (2) ◽  
pp. 43-50
Author(s):  
Yusup Hendronursito ◽  
Muhammad Amin ◽  
Slamet Sumardi ◽  
Roniyus Marjunus ◽  
Frista Clarasati ◽  
...  
Keyword(s):  
Particle Size ◽  
Rotational Speed ◽  
Inductively Coupled Plasma ◽  
Chemical Elements ◽  
Silica Content ◽  
X Ray ◽  
Concentration Variation ◽  
Leaching Process ◽  
Hcl Concentration ◽  
Granite Powder

This study was aimed to increase granite's silica content using the leaching process with HCl concentration variation. The granite used in this study came from Lematang, South Lampung. This study aims to determine the effect of variations in HCl concentration, particle size, and rotational speed on the crystalline phase and chemical elements formed in the silica product produced from granite. The HCl concentration variations were 6.0 M, 7.2 M, 8.4 M, and 9.6 M, the variation in particle size used was 270 and 400 mesh. Variations in rotational speed during leaching were 500 and 750 rpm. Granite powder was calcined at 1000 ºC for 2 hours. Characterization was performed using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP- OES). The results showed that the silica content increased with increasing HCl concentration, the finer the particle size, and the higher the rotational speed. XRF analysis showed that the silica with the highest purity was leached with 9.6 HCl with a particle size of 400 mesh and a rotational speed of of 750 rpm, which was 73.49%. Based on the results above, by leaching using HCl, the Si content can increase from before. The XRD diffractogram showed that the granite powder formed the Quartz phase.

IN-VITRO BEHAVIOUR OF BIPHASIC CALCIUM PHOSPHATE WITH DIFFERENT RATIO OF SILICA CONTENT IN SIMULATED BODY FLUID

2015 ◽  
Vol 23 (1) ◽  
pp. 1-14
Author(s):  
Sudirman Sahid ◽  
◽  
Nor Shahida Kader Bashah ◽  
Salina Sabudin ◽  
◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Biphasic Calcium Phosphate ◽  
Silica Content
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