Application Of Microwave Techniques Research Articles

Fabrication of Cellulosic Nonwoven-Based Wound Dressings Coated with CTAB-Loaded Double Network PAMPS/PNaA Hydrogels

ABSTRACT Novel approaches have been implemented to fabricate wound dressings including electrospinning of hydrogels, and coating-based nonwoven hydrogels. In this study, only the coating technique was studied in order to fabricate wound dressing. For this purpose, nonwoven cotton fabrics were coated with layer-by-layer PNaA (poly sodium acrylate) and poly 2-Acrylamido-2-methylpropane sulfonic acid (PAMPS). Microwave techniques were then implemented to create an antibacterial activity using cetyltrimethylammonium bromide (CTAB). For the characterization, the physical, mechanical and antibacterial properties of the different samples and to determine potential wound dressing candidates, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), swelling, and water vapor permeability (WVP) tests as well as contact angle measurements with water were performed. The application of microwave techniques using CTAB on the fabricated nonwoven-based wound dressings showed potential results of creating an efficient antibacterial activity with high fibroblast cell viability. The in vitro aspirin release experiment confirmed that the release amount depended on the number of hydrogel layers. The results of physical and mechanical tests showed that coated nonwoven with layers of hydrogels had the desired strength along breathability, flexibility, and wettability. These cumulative results indicate that the fabricated structures in this work are good potential candidates for wound dressing applications.

The Riveting Chemistry of Poly‐aza‐heterocycles Employing Microwave Technique: A Decade Review

AbstractThe application of microwave technique in chemical laboratory rooted back in 1986 and found advantageous over conventional approaches. On the other side, poly‐aza‐heterocycles are influencing organic frameworks with a fascinating chemistry and well explored by employing microwave‐assisted organic reactions. In the present review, we have thoroughly updated rousing literatures of microwave‐assisted synthesis and reactions of various poly‐aza‐heterocycles viz., triazole, tetrazole, triazine, and tetrazine from the past decade (2010–2020). The expedient chemistry and enabling role of microwave heating for adequate chemical transformations of such heterocycles, which were more challenging using classical approaches, are appropriately elucidated. This review also highlights the potential applications of these heterocyclic scaffolds and their derivatives in different scientific domains. Remarkably, such chemical architects possess wide applications as crucial building blocks in synthesis of biologically relevant compounds, agrochemicals, and compounds of interest in material science.

Microwave Roasting Pyrite for Removal of the Sulfur and Arsenic

The application of microwave technique in the roasting pyrite which contained little arsenic was described. The characteristics of microwave absorption of pyrite were investigated. The results indicated that pyrite was a good absorbent of microwave and heated rapidly to high temperature by microwave flied in a short time, causing decomposition and oxidization to removal the sulfur and arsenic. The effects of microwave irradiation time and sample mass on the removal efficiencies of sulfur and arsenic with microwave power of 4 kW and 6 kW were investigated. The big microwave power could shorten the time for removal of sulfur and arsenic. Finally iron concentrate contained 64.52% Fe, S<0.1%, As<0.094% were obtained.

Microwave Technology Based Polymer Process

In this paper the author summarizes the application of microwave techniques in the bulk polymerization, solution polymerization, emulsion polymerization and functional polymer. It is pointed out that the microwave technology can reduce the time and energy consumptions of the polymerization reaction, and improve the properties of polymeric reaction rate, yield and selectivity, which will play an important role in the green chemistry synthesis of polymers.

Microwave-Assisted Synthesis and Pharmacological Activity of Pyrazolyl Benzofuran Deravatives

Microwave-assisted Organic Reaction Enhancement (MORE) has emerged as a new ‘lead’ in organic synthesis. During the studies we observed that microwave –assisted organic synthesis requires 2-4 min. of time whereas the conventional ones takes 4-6 hrs and often with poor yields. Hence, with an objective of reducing the reaction time, application of microwave technique has proved to be advantageous in case of synthesis of new benzofuran derivatives. The structures of synthesized derivatives emerged is confirmed by their IR, NMR and Mass spectra. The representative compounds synthesized with this route is further screened for anti-bacterial, analgesic, anti-inflammatory and ulcerogenic studies. In this study we have observed that the benzofuran derivatives are less ulcerogenic compared to phenyl butazone. The structural comparisons have revealed that the chloro substitution will increase the ulcerogenic toxicity.

Application of Microwave Technique into Etherification of 10-Hydroxycamptothecin

Application of Microwave Technique into Etherification of 10-Hydroxycamptothecin

Leaching of nickel laterite ore assisted by microwave technique

The application of microwave technique in the hydrometallurgy of nickel laterite ores was described. The mixture of nickel laterite ores and sulfuric acid was pre-treated by microwave irradiation. The dissolving of nickel was conducted in hot water at the atmospheric pressure. The effects of factors, such as microwave power, microwave irradiation time, and sulfuric acid dosage, were investigated. In microwave field, the migration of ionic species and/or rotation of dipolar species promote the liquid–solid reaction process due to the increased contact area of reactants and leaching reaction rate constant. Thanks to the strengthening action of microwave, the microwave-assisted leaching process has its advantages, such as higher extracting rate than conventional atmospheric leaching, and no need for high-pressure operation as high pressure acid leaching (HPAL). The ferric iron in leaching solution could be effectively removed by sodium jarosite process with a little loss of nickel in the jarosite precipitate.

A Review: Application of Microwave Techniques for Environmental Analytical Chemistry

The acceptance of microwave digestion technique is based on procedures successfully carried out for mist different kinds of samples. The goals of this paper are to gather all information concerning applications of microwave digestion methods to analytical chemistry. Some applications of microwave techniques to sample digestion, solvent extraction, sample drying, the measurements of moisture, analyte desorption and adsorption, sample clean up, chromomeric reaction, speciation, and nebulization of analytical samples are presented.

Novel Applications of Microwave Techniques in the Food and Environmental Industries

During the microwave processing, despite the conventional heating, the material heats consistently inside. This property of microwave is utilized by drying and dehydration processes. The thermal sensitivity of raw materials of food industry requires development of gentle, fast and controllable technologies, which is realizable by means of combination of conventional and microwave techniques. The other important application area of the microwave technique is food industrial practice is enhancing the microbial safety of products, mainly by pasteurization processes. In recent time the strict environmental regulation necessitate developing more effective treatment of wastes, waste waters and sewage sludge. Because a part of these techniques are heat and power demanded, the microwave technique may be an alternative process in execution of sludge conditioning, drying or gasification and pyrolysis.

Microwave‐Assisted Synthesis and Diels—Alder Reactions of 1,3‐Azaphospholo[5,1‐a]isoquinolines.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Microwave‐assisted synthesis and diels–alder reactions of 1,3‐azaphospholo[5,1‐a]isoquinolines

AbstractThe application of microwave technique has been extended successfully for the first time to the synthesis of a representative class of azaphospholes, viz. 1,3‐bis(alkoxycarbonyl)‐1,3‐azaphospholo[5,1‐a]isoquinolines (2), which occurs rapidly giving higher yields. Stereoselectivity is observed in the reaction with 2,3‐dimethyl‐1,3‐butadiene, and isoprene reacts regioselectively as well. 1‐Methyl‐3‐ethoxycarbonyl‐1,3‐azaphospholo[1,5‐a]pyridine (4) remains inert toward [2+4] cycloaddition. The nonoccurrence of the Diels–Alder reaction in the latter case has been supported by semiempirical PM3 calculations. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:560–563, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10193

The application of microwave techniques in multiple immunostaining and in situ hybridization

Summary: We describe simple, rapid, reliable and sensitive microwave‐based methods for both multiple immunostaining and in situ hybridization. This technique involves treating sections with a 10 min period of microwave oven heating. the ability of microwave oven heating to retrieve cytoplasmic and nuclear antigens, block antibody cross‐reactivity and inactivate peroxidase and alkaline phosphatase enzymes has resulted in the development of a simple and generally applicable method of multiple immunostaining in which two or more antigens can be detected within the same section using primary antibodies raised in the same species combined with a sensitive three layer staining protocol involving peroxidase anti‐peroxidase (PAP) and alkaline phosphatase anti‐alkaline phosphatase (APAAP) complexes. the application of microwave oven heating as a pretreatment of cryostat sections prior to in situ hybridization using digoxigenin‐labelled cRNA and cDNA probes resulted in improved probe access to target nucleic acid sequences, stronger hybridization signals, reduced hybridization times, maintenance of excellent tissue morphology and outstanding reliability. Thus, the application of microwave oven heating has overcome many of the difficulties associated with current protocols used in these two techniques. These new methodologies have general applicability and will be of significant benefit to both research scientists and clinical pathologists alike.

Microwave stimulated cell marker analysis. Possibilities for more rapid immune diagnosis

We describe a successful rapid APAAP-complex technique using innovative application of microwave irradiation (MIWI) on Ficoll separated peripheral blood mononuclear cell smears of healthy donors. The typing with several monoclonal antibodies (MoAbs) against different cell surface antigens is compared with the conventional APAAP procedure. The commercial domestic microwave oven was operated at 2.45 GHz. Fifteen second irradiation at 350 W during all incubation steps, e.g. primary antibody, bridging antibody and APAAP-complexes produced excellent color reactions with Fast Red TR, Fast Blue BB, New Fuchsin or NBT similar with the conventional immunoenzyme procedure. The routinely usage of a Silicon-Chamber-System developed by us is applicable without limitation under microwave conditions. The results till now have shown that the application of microwave-technique (MIWI) eliminated the need for much longer incubation periods without lost of sensitivity. All immunological markers could be detected in the same degree as observed with the conventional method. We could demonstrate that an immunological diagnosis is possible within 30 minutes using air dried smears in an microwave oven.

The application of microwave techniques in lightwave systems

Microwave techniques have a significant role in advancing the state-of-the-art of lightwave systems. Applications include the analysis and design of structures to support lightwave propagation, the development of devices and circuits to modulate, demodulate, and process microwaves bandwidth signals on lightwave carriers, and the development of circuits to process microwave bandwidth baseband signals. The merging of microwave and lightwave technologies will open new opportunities in system design.

Application of microwave techniques to high-energy physics experiments at Argonne national laboratory

High-energy physics research as conducted at Argonne National Laboratory is characterized by transport of beams of highly relativistic charged particles, and detection and analysis of the interaction of these particles with one another. Microwave systems find application in both areas. In beam transport RF separators are frequently used to physically separate particles of different quantum mass. Microwave discharge chambers are used for particle detection and polarized proton targets are used to analyze the scattering of particles.

Microwave techniques in the study of semiconductors

Application of microwave techniques to the study of semiconductors is steadily gaining importance for various reasons. This paper describes some microwave methods for the measurement of semiconductor parameters developed at the Institute of Radio Physics and Electronics, University of Calcutta, India. The theory of conduction in semiconductors at microwave frequencies is first reviewed briefly. A SWR method is then outlined and its application to the study of temperature variation of conductivity and dielectric constant is discussed. An experimental arrangement for the measurement of surface conductance utilizing the above method is also described. A technique for the measurement of infrared absorption coefficient of a semiconductor is then presented and the experimental results obtained with a p-type silicon sample are given. The paper concludes with a description of two different methods developed for measuring the minority carrier lifetime. The possibility of utilizing one of these methods for obtaining the diffusion length, diffusion constant and surface recombination velocity in addition to lifetime, is also indicated.