Crystal structures and physical chemical properties of nedocromil zinc heptahydrate and nedocromil magnesium pentahydrate

1996 ◽  
Vol 26 (3) ◽  
pp. 167-178 ◽  
Author(s):  
William H. Ojala ◽  
Rajendra K. Khankari ◽  
David J. W. Grant ◽  
William B. Gleason
Keyword(s):  
Crystal Structures ◽  
Chemical Properties ◽  
Physical Chemical

Usability evaluation of 3-D visualisations augmented by cartoons for teaching solids and crystal structures in chemical engineering

2018 ◽  
Vol 5 (4) ◽  
pp. 83-89
Author(s):  
Konstadina Dalacosta ◽  
Evangelia. A. Pavlatou
Keyword(s):  
Crystal Structures ◽  
Undergraduate Students ◽  
Conceptual Understanding ◽  
Chemical Engineering ◽  
Chemical Properties ◽  
Main Idea ◽  
Zinc Sulphide ◽  
Freedom Of Movement ◽  
Physical Chemical ◽  
Digital Material

In chemical engineering, undergraduate students often have to face the highly demanding process of understanding concepts from the microscopic level (e.g., ionic crystals such as zinc sulphide or covalent lattice crystals diamond, graphite, graphene etc.) and then explain with certain physical–chemical properties their macroscopic behaviour. Therefore, the main idea was to construct a specifically designed educational material that focusses on the benefits of viewing visualisations to enhance students’ conceptual understanding of solids and crystal structures augmented by cartoons, and evaluate its usability. The interactive ‘cartoons’ agents were developed from scratch, giving them freedom of movement and realism at the same time. A research was conducted in the School of Chemical Engineering in Greece (National Technical University of Athens), evaluated the usability of the digital material and the contribution of the 3-D visualisations and the cartoons agents in the understanding of such high-cognitive load concepts.Keywords: Cartoons, 3-D visualisations, crystal structures, chemical engineering.

scholarly journals Structural Characterization of Albendazole with the Use of X-Ray Diffraction

2014 ◽  
Vol 70 (a1) ◽  
pp. C1808-C1808 ◽  
Author(s):  
Kelly Lixandrão ◽  
Fabio Ferreira
Keyword(s):  
Crystal Structures ◽  
Structural Characterization ◽  
Rietveld Method ◽  
Low Cost ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Physical Chemical

Drugs may present polycrystalline polymorphism (property of a substance to crystallize in more than one form or crystal structure). These variations can cause changes in physical-chemical properties and differences between the polymorphs as shape, solubility, density, melting range, among other consequences, leading to formulations that are not effective, although the chemical formula is the same [1]. Drugs such as albendazole (C12H15N3O2S, which is one of the most effective anthelmintics, [2] showing activity against nematodes, trematodes and cestodes, reasons that added to its safety and low cost have made it a drug widely used in human medicine and veterinary), has more than two different crystal structures, and only two of them are known. The X-ray powder diffraction is a powerful technique used in the structural characterization of drugs, and coupled with the Rietveld method [4], the quantification of the active phases, through the knowledge of their crystal structures, becomes possible. In this paper we discuss results on the differences between the polymorphs of albendazole, with data obtained by means of X-ray diffraction, thermal analysis (differential scanning calorimetry and thermogravimetric analysis), Fourier transform infrared spectroscopy and scanning electron microscopy.

BiCuSeO oxyselenides: new promising thermoelectric materials

2014 ◽  
Vol 7 (9) ◽  
pp. 2900-2924 ◽  
Author(s):  
Li-Dong Zhao ◽  
Jiaqing He ◽  
David Berardan ◽  
Yuanhua Lin ◽  
Jing-Feng Li ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Thermoelectric Materials ◽  
Electronic Structures ◽  
Chemical Properties ◽  
Thermoelectric Performance ◽  
Physical Chemical ◽  
System P

This review summarizes the crystal structures, microstructures, electronic structures, physical/chemical properties, and effective methods to enhance the thermoelectric performance of the BiCuSeO system.

Chlorinated Organics in Nearshore Waters and Tributaries of the St. Clair River

1986 ◽  
Vol 21 (3) ◽  
pp. 344-350 ◽  
Author(s):  
Barry G. Oliver ◽  
Klaus L.E. Kaiser
Keyword(s):  
United States ◽  
Suspended Sediment ◽  
Waste Disposal ◽  
Large Volume ◽  
Water Samples ◽  
Chemical Properties ◽  
Low Level ◽  
Chemical Company ◽  
Physical Chemical ◽  
The Individual

Abstract The concent rat ions of hexachloroethane (HCE), hexachlorobutadiene (HCBD), pentachlorobenzene (QCB), hexachlorobenzene (HCB) and octachlorostyrene (OCS) in large volume water samples show that the major sources of these chemicals to the St. Clair River are Dow Chemical Company effluents and, to a lesser degree, Sarnia’s Township ditch which drains one of Dow’s waste disposal sites. Tributaries entering the river on both sides of the Canada/United States border contain measurable concentrations of these chemicals indicating low level contamination throughout the area. The degree of water/suspended sediment partitioning of the chemicals (Kp) was studied. Kp values for the individual chemicals changed in a manner consistent with changes in their physical-chemical properties.

Polymer-Graphene Nanoassemblies and their Applications in Cancer Theranostics

2020 ◽  
Vol 20 (11) ◽  
pp. 1340-1351 ◽  
Author(s):  
Ponnurengam M. Sivakumar ◽  
Matin Islami ◽  
Ali Zarrabi ◽  
Arezoo Khosravi ◽  
Shohreh Peimanfard
Keyword(s):  
Mechanical Stability ◽  
Chemical Properties ◽  
The Other ◽  
Hydrophilic Polymer ◽  
Two Dimensional ◽  
Normal Tissues ◽  
Physical Chemical ◽  
Anti Cancer ◽  
Good Biocompatibility ◽  
Cancer Theranostics

Background and objective: Graphene-based nanomaterials have received increasing attention due to their unique physical-chemical properties including two-dimensional planar structure, large surface area, chemical and mechanical stability, superconductivity and good biocompatibility. On the other hand, graphene-based nanomaterials have been explored as theranostics agents, the combination of therapeutics and diagnostics. In recent years, grafting hydrophilic polymer moieties have been introduced as an efficient approach to improve the properties of graphene-based nanomaterials and obtain new nanoassemblies for cancer therapy. Methods and results: This review would illustrate biodistribution, cellular uptake and toxicity of polymergraphene nanoassemblies and summarize part of successes achieved in cancer treatment using such nanoassemblies. Conclusion: The observations showed successful targeting functionality of the polymer-GO conjugations and demonstrated a reduction of the side effects of anti-cancer drugs for normal tissues.

scholarly journals Shellfish Chitosan Potential in Wine Clarification

2021 ◽  
Vol 11 (10) ◽  
pp. 4417
Author(s):  
Veronica Vendramin ◽  
Gaia Spinato ◽  
Simone Vincenzi
Keyword(s):  
Molecular Structure ◽  
Chemical Properties ◽  
Allergic Reactions ◽  
Chitin Content ◽  
Deacetylation Degree ◽  
Physical Chemical ◽  
Similar Chemical ◽  
Fungal Chitosan ◽  
Significant Difference ◽  
Fish Industry

Chitosan is a chitin-derived fiber, extracted from the shellfish shells, a by-product of the fish industry, or from fungi grown in bioreactors. In oenology, it is used for the control of Brettanomyces spp., for the prevention of ferric, copper, and protein casse and for clarification. The International Organisation of Vine and Wine established the exclusive utilization of fungal chitosan to avoid the eventuality of allergic reactions. This work focuses on the differences between two chitosan categories, fungal and animal chitosan, characterizing several samples in terms of chitin content and degree of deacetylation. In addition, different acids were used to dissolve chitosans, and their effect on viscosity and on the efficacy in wine clarification were observed. The results demonstrated that even if fungal and animal chitosans shared similar chemical properties (deacetylation degree and chitin content), they showed different viscosity depending on their molecular weight but also on the acid used to dissolve them. A significant difference was discovered on their fining properties, as animal chitosans showed a faster and greater sedimentation compared to the fungal ones, independently from the acid used for their dissolution. This suggests that physical–chemical differences in the molecular structure occur between the two chitosan categories and that this significantly affects their technologic (oenological) properties.

scholarly journals Electrospinning: A promising technique for drug delivery systems

2020 ◽  
Vol 59 (1) ◽  
pp. 441-454
Author(s):  
Carlos A. Martínez-Pérez
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Chemical Properties ◽  
Delivery Systems ◽  
Extrinsic Factor ◽  
Promising Technique ◽  
Physical Chemical ◽  
Set Up ◽  
Final System ◽  
Intense Research

AbstractIn the last years, electrospinning has become a technique of intense research to design and fabricate drug delivery systems (DDS), during this time a vast variety of DDS with mainly electrospun polymers and many different active ingredient(s) have been developed, many intrinsic and extrinsic factor have influence in the final system, there are those that can be attributed to the equipment set up and that to the physical-chemical properties of the used materials in the fabrication of DDS. After all, this intense research has generated a great amount of DDS loaded with one or more drugs. In this manuscript a review with the highlights of different kind of systems for drug delivery systems is presented, it includes the basic concepts of electrospinning, types of equipment set up, polymer/drug systems, limitations and challenges that need to be overcome for clinical applications.

Variability in soil physical–chemical properties along the root-explored profile in deep Oxisols of commercial eucalypt plantations

2021 ◽  
Vol 494 ◽  
pp. 119334
Author(s):  
Vinicius Evangelista Silva ◽  
Thiago Assis Rodrigues Nogueira ◽  
Cassio Hamilton Abreu-Junior ◽  
Arun Dilipkumar Jani ◽  
Salatier Buzetti ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Physical Chemical ◽  
Eucalypt Plantations
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