Preparation and Properties of Tourmaline/Chitosan Composite Powder

Chitosan has good biocompatibility and physiological activity, tourmaline possesses characteristics of generation of anion, reduction of water molecular beam and emission of far infrared radiation, so the two composite materials will hopefully possesses the two excellent properties, thus show good application prospect in the biomedical and cosmetic field. Experiment utilized chitosan as wrapped base material, adopt method of suspension solution compound precipitation to manufacture chitosan/tourmaline compound powder, using XRD, SEM, IR and other means to represent powders prepared, and the experimental results show that the synthetic compound powder with irregular granular, chitosan wrapped tourmaline well, the composite of tourmaline and chitosan is physical composite, with the increment of tourmaline , the degree of crystallization of chitosan in compound powder weaken, the composite powder has good absorptive and preservative liquid ability.

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Collagen-Chitosan Composite Powder as a Novel Biomaterial for Chronic Wounds in Hansen Disease-A Clinical Study

Journal of Pharmaceutical Research International ◽

10.9734/jpri/2021/v33i49b33352 ◽

2021 ◽

pp. 154-165

Author(s):

Pombala Suresh Babu ◽

Harini Srinivasan ◽

B. Sai Dhandapani ◽

C. Rose

Keyword(s):

Wound Repair ◽

Composite Powder ◽

Chronic Wounds ◽

Waste Product ◽

Wound Dressings ◽

Meat Industry ◽

Before And After ◽

Hematoxylin And Eosin ◽

Chitosan Composite

Aims: Natural biomaterials are more suitable than synthetic biomaterials for in vivo applications for treating damaged tissues. Collagen and chitosan are abundantly available natural biomaterials for wound dressings for tissue/wound repair. In this context, collagen-chitosan composite powder has been used to treat chronic wounds in Hansen disease (HD) patients. Place and Duration of Study: CSIR Central Leather Research Institute, Sardar Patel Road, Adyar, Chennai 600021, Southern Railway Headquarters Hospital, Constable Road, Ayanavaram, Chennai 600023, and Gremaltes Hospital, India between June 2013 and July 2020. Methodology: Collagen extracted from bovine rumen, a waste product of meat industry, and a commercially available chitosan were prepared as a composite powder (COL/CS) and applied to chronic wounds in HD patients after debridement and the wound contours were measured by planimetry. Biochemical parameters in blood samples were periodically assessed. Histopathology of wound tissue with Hematoxylin and Eosin and Masson’s Trichrome staining was studied. Matrix Metalloproteinase-9 (MMP9) levels before and after treatment were estimated. Results: Wound healing of 64.2% was obtained with COL/CS treatment and formation of granulation cells was observed early. Hemogram studies have been reported in a regression model with 95% confidence intervals. Histopathology revealed dense collagen fibres and continuity of sub-epithelial layer on 8th day. MMP-9 levels showed collagen integrity after treatment. Conclusion: The novel biocompatible, biodegradable COL/CS wound dressing is a promising biomaterial for management of chronic wounds in Hansen disease patients.

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Cracking Behavior of Two Kinds of Plasma Cladding Layers by Precursor Carbonization-Composition Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.2046 ◽

2013 ◽

Vol 690-693 ◽

pp. 2046-2050

Author(s):

Jun Bo Liu

Keyword(s):

Composite Powder ◽

Raw Materials ◽

Base Material ◽

Fiber Direction ◽

X Ray Diffraction ◽

Cracking Behavior ◽

Plasma Cladding ◽

Reactive Plasma ◽

Composition Process ◽

Cladding Layers

In-situ synthesized two kinds of Fe-Cr-C and Fe-Cr-C-Ti layers were fabricated on the base of Q235 steel by reactive plasma cladding process using composite powder prepared by precursor carbonization-composition process as raw materials. The composite powder is composed of ferrotitanium, chromium, iron and precursor sucrose. Microstructure of the layer was observed by scanning electron microscope (SEM). The phases in the layer were determined by X-ray diffraction (XRD). Results indicate that the Fe-Cr-C layer consists of primary (Cr,Fe)7C3 carbide, chrysanthemum-shaped eutectic (Cr,Fe)7C3 carbide and eutectic austenite. The cracks in Fe-Cr-C layer might originate at the interface of the layer and the base material as well as at the pores or edges of the layer. These cracks expand along primary (Cr,Fe)7C3 grain boundaries in a crystalline form. Because the grains of primary (Cr,Fe)7C3 are fiber-shaped and the fiber direction are perpendicular to the surface of the layer, so the cracks expand perpendicularly throughout of the Fe-Cr-C layer. The Ti addition into Fe-Cr-C plays an important role in synthesizing TiC and austenite, reducing primary (Cr,Fe)7C3 and improving the microstructure of eutectic (Cr,Fe)7C3. Therefore, Fe-Cr-C-Ti has good performance in toughness and crack-resistance.

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Elevated Temperature Characteristics of Carbon-Doped GaInP/GaAs Heterojunction Bipolar Transistor Grown by Solid Source Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-799-z5.13 ◽

2003 ◽

Vol 799 ◽

Author(s):

Zhang Rong ◽

Yoon Soon Fatt ◽

Tan Kianhua ◽

Sun Zhongzhe ◽

Huang Qingfeng

Keyword(s):

Activation Energy ◽

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Base Material ◽

Bipolar Transistor ◽

Heterojunction Bipolar Transistor ◽

Collector Current ◽

Carbon Doped ◽

Base Current ◽

Recombination Current

ABSTRACTThis paper reports the characteristics of GaInP/GaAs heterojunction bipolar transistor (HBT) with carbon-doped GaAs base layer grown by solid source molecular beam epitaxy (SSMBE) using carbon tetrabromide (CBr4) as p-type dopant precursor. Hydrofluoric acid (HF) was used to passivate the GaInP/GaAs HBTs. At base bias voltages below 0.8V in the Gummel plot, the base current of large-area devices after HF treatment was greatly reduced. This indicates that the extrinsic base surface recombination current was greatly reduced. After HF treatment, detailed DC characterization of the device performance from 300K to 380K was carried out and the carrier transport properties were investigated. The base current and collector current ideality factors at 300K were 1.12 and 1.01, respectively. This indicates that the space- charge region recombination current in the base is insignificant. From the temperature- dependent Gummel plot, the activation energies of collector current and base current were obtained. For the collector current, the activation energy is 1.4eV, which is close to the bandgap of the GaAs base. This indicates that the collector current is determined by the drift-diffusion process, in which an energy barrier of the same magnitude as the base bandgap is to be overcome by electrons before they reach the collector. For the base current, the activation energy is also 1.4eV, which is close to the bandgap of GaAs, indicating that band-to-band recombination plays a dominant role in the base current. No trap-related recombination was observed for the base and collector currents, which further indicates the high quality carbon-doped GaAs base material for the HBT structures.

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Far-infrared transmission in GaN, AlN, and AlGaN thin films grown by molecular beam epitaxy

Journal of Applied Physics ◽

10.1063/1.2968242 ◽

2008 ◽

Vol 104 (3) ◽

pp. 033544 ◽

Cited By ~ 32

Author(s):

J. Ibáñez ◽

S. Hernández ◽

E. Alarcón-Lladó ◽

R. Cuscó ◽

L. Artús ◽

...

Keyword(s):

Thin Films ◽

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Far Infrared ◽

Infrared Transmission

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Far-infrared spectroscopy using a tunable light source and a molecular beam

Technical Digest. CLEO/Pacific Rim'95. The Pacific Rim Conference on Lasers and Electro-Optics ◽

10.1109/cleopr.1995.527233 ◽

2005 ◽

Author(s):

F. Matsushima ◽

H. Odashima ◽

H. Nagase ◽

S. Tsunekawa ◽

K. Takagi

Keyword(s):

Infrared Spectroscopy ◽

Light Source ◽

Molecular Beam ◽

Far Infrared ◽

Far Infrared Spectroscopy

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Far-Infrared Optically Detected Cyclotron Resonance in GaAs Layer Grown by Molecular Beam Epitaxy

Japanese Journal of Applied Physics ◽

10.1143/jjap.36.l209 ◽

1997 ◽

Vol 36 (Part 2, No. 2B) ◽

pp. L209-L212 ◽

Cited By ~ 1

Author(s):

Hiroyasu Nakata ◽

Tatsuki Iwao ◽

Tyuzi Ohyama

Keyword(s):

Molecular Beam Epitaxy ◽

Cyclotron Resonance ◽

Molecular Beam ◽

Far Infrared ◽

Gaas Layer ◽

Optically Detected

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Realization of the Kohn’s Theorem in Ge/Si Quantum Dots with Hole Gas: Theory and Experiment

Nanomaterials ◽

10.3390/nano9010056 ◽

2019 ◽

Vol 9 (1) ◽

pp. 56 ◽

Cited By ~ 7

Author(s):

Hayk A. Sarkisyan ◽

David B. Hayrapetyan ◽

Lyudvig S. Petrosyan ◽

Eduard M. Kazaryan ◽

Anton N. Sofronov ◽

...

Keyword(s):

Quantum Dots ◽

Quantum Dot ◽

Molecular Beam ◽

Far Infrared ◽

Resonant Absorption ◽

Experimental Results ◽

Quantum Transitions ◽

Si Quantum Dots ◽

Specific Quantum ◽

Good Agreement

This article discusses specific quantum transitions in a few-particle hole gas, localized in a strongly oblate lens-shaped quantum dot. Based on the adiabatic method, the possibility of realizing the generalized Kohn theorem in such a system is shown. The criteria for the implementation of this theorem in a lens-shaped quantum dot, fulfilled in the experiment, is presented. An analytical expression is obtained for the frequencies of resonant absorption of far-infrared radiation by a gas of heavy holes, which depends on the geometric parameters of the quantum dot. The results of experiments on far-infrared absorption in the arrays of p-doped Ge/Si quantum dots grown by molecular beam epitaxy (MBE) with gradually increasing average number of holes in dot are presented. Experimental results show that the Coulomb interaction between the holes does not affect the resonant frequency of the transitions. A good agreement between the theoretical and experimental results is shown.

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