Laser Modification of Leather and Fur Surface to Improve Its Quality when Conducting Finishing Operations

2020 ◽  
Vol 20 (4) ◽  
pp. 353-360
Author(s):  
Akmal Yusupovich TOSHEV ◽  
Mariya Ivanovna MARKEVICH ◽  
Tulkin Jumayevich KODIROV ◽  
Valentina Illarionovna ZHURAVLEVA

The article discusses the problems of activation of the surface of the leather tissue by laser exposure, changes in the morphology of the surface of the leather tissue during laser processing, and subsequent covering dyeing of the leather. It is shown that laser treatment changes the structure of the surface of the leather tissue, the bundles of collagen fibers are split, the structure becomes loose, which increases the diffusion of the coating dye reagents, and their reactivity increases without chemical modification. In the process of grinding leather fabric, it is finely cleaned which improves adhesion of the coating paint to the surface of the leather fabric, which improves the quality of leather fabric products. It was shown that laser exposure under the conditions found (pulses with an interval of 3 μs, a duration of 10 ns) does not cause destruction and configuration changes in collagen.

2021 ◽  
Vol 14 (1) ◽  
pp. 11-15
Author(s):  
Łukasz Hajac ◽  
Martyna Hajac ◽  
Adam Maciejczyk

Nausea and vomiting are one of most frequent side effects of chemotherapy and radiotherapy. Effective prevention and treatment of these symptoms is essential for better quality of life for patients undergoing oncological therapies. Nausea and vomiting can be acute, delayed or anticipatory. Leading mechanisms and methods of treatment are different for each of those. Most often used groups of drugs are: 5-HT3-antagonists, glucocorticosteroids, NK1-antagonists. Another important group are neuroleptics, which are therapy of choice for anticipatory vomiting. Modern antiemetic medications are in most cases safe and effective. But as every treatment it causes risks of adverse events which may be serious and difficult to manage. It applies in particular to long-acting drugs. Most common side effects are headache, constipation and sedation. But more severe or life-threatening symptoms may appear, like intestinal obstruction and serotonin syndrome. Some of the drugs also come with risk of interacting with other treatment. Changes in pharmacokinetics may lead to additional toxicities. In elderly, especially with cardiac disease, in risk of ileus or cachexia these drugs shall be used with caution.


1995 ◽  
Vol 10 (8) ◽  
pp. 1884-1888 ◽  
Author(s):  
S. Krishnan ◽  
M.I. Chaudhry ◽  
S.V. Babu

Amorphous silicon germanium (a-SiGe) films, deposited on silicon substrates at room temperature in a molecular beam epitaxy system, were transformed into a single-crystal film and doped with phosphorus by exposure to KrF laser pulses. Electron channeling patterns showed that laser exposure resulted in crystallization of the undoped a-SiGe films. The SiGe films were doped by laser irradiation, using a phosphorus spin-on-dopant. The sheet resistance of the doped films decreased with increasing numbers of pulses, reaching a value of about ∼ 5 × 104 ohms/□ after 15 pulses. I-V data from mesa-type n-SiGe/p-Si diode devices were used to determine the effect of laser processing on the quality of the SiGe films.


2021 ◽  
Vol 64 (2) ◽  
pp. 79-86
Author(s):  
Olga Macagonova ◽  
◽  
Doina Risnic ◽  
Adrian Cociug ◽  
Viorel Nacu ◽  
...  

Background: The extracellular matrix plays an important role in the promoting the tissue regeneration and repair. Decellularization or removal of the cells from the complex mixture of the structural and functional proteins that constitute the extracellular matrix (ECM) can be done by the physical (agitation, sonication, freeze and thaw), chemical (alkaline orchids, ionic detergents, nonionic, tri-n-butyl phosphate (TBP), hypotonic or hypertonic treatments, chelating agents), and enzymatic methods (trypsin or protease inhibitors). However, complications associated with the use of the decellularized skin have been reported, which are widespread and poorly understood. In this synthesis have been included publications, identified by the Google Search engine, National Bibliometric Tool (NBT), Pub Med databases, Web of Science, Springer, Elsevier, Wiley Online Library, Science Direct and Biosience, Biotechnology and Biochemistry. The results of the decellularization were reported in terms of the number of cells remaining in the collagen fibers depending on the duration of exposure to chemical agents. Conclusions: The natural matrix is more widely used than synthetic material, because it has the natural structure and composition of the ECM, it naturally stimulates cell development and allows the incorporation of the growth factors and other proteins increasing cell proliferation.The assessment of the quality of decellularization techniques is done by evaluating the necrosis of the extracellulare matrix, the depletion of the collagen fibers and the remaining amount of genetic material.


2021 ◽  
Vol 871 ◽  
pp. 277-283
Author(s):  
Chun Yan Yang ◽  
Yun Hao ◽  
Bozhe Wang ◽  
Hai Yuan ◽  
Liu Hui Li

A picosecond laser in spin-cutting mode was used to drill 500μm diameter microholes on 150μm thick aluminium nitride ceramic. The effects of laser processing parameters such as the laser power, scanning speed, and defocus amount on the microhole quality were studied. The results show that as the laser power increases, the inlet and outlet diameters of the holes increase, the taper decreases slightly, and the thickness of the recast layer decreases evidently. The scanning speed has no obvious effect on the diameter and taper of the hole; however, the hole can not be drilled through when the speed is too large. Positive defocus can effectively reduce the taper of the hole. Under 28.5W laser power, 400Hz frequency, 200mm/s scanning speed, and zero defocus amount conditions, high-quality microholes with a taper of 0.85° were obtained.


2009 ◽  
Vol 12 (1) ◽  
pp. 7-9 ◽  
Author(s):  
Ali Maziar ◽  
Nader Farsi ◽  
Manijeh Mandegarfard ◽  
Shahab Babakoohi ◽  
Farzam Gorouhi ◽  
...  

Author(s):  
Anna Meynköhn ◽  
Sebastian Fischer ◽  
Clara Neuss ◽  
Lina Marie Willkomm ◽  
Ulrich Kneser ◽  
...  

2016 ◽  
Vol 703 ◽  
pp. 27-33
Author(s):  
Liang Wang ◽  
Nai Fei Ren ◽  
Yun Long Wang ◽  
Lin Zhong Zhu

Both superalloy GH2135 and stainless steel 420J1 were used as test materials to be processed by LASERTEC 80 PowerDrill three-dimensional solid laser processing center. The microstructure of the hole was investigated by super depth of field microscope and laser scanning microscope. The front and back orifice diameter, orifice deposits and thermal effect of accumulation zone were studied. The single factor test method was used to study the influence of pulse energy, pulse width and repetition frequency on the quality of micro holes. The results showed that the front and back diameter of the holes all increase with the increase of pulse energy from 0.4J-3.9J. And the front and back aperture are increase with the increase of pulse width from 0.9ms-1.9ms. Meanwhile, the variation of the aperture and pore taper is more noticeable with the repetition frequency changed from 10Hz-60Hz. The results revealed that pulse energy is one of the biggest influence factors, large pulse energy can lead to small hole taper within a certain range, and short pulse width can reduce orifice debris and splash. Both the recast layer and microcrack were existed in the two kinds of metal materials. The quality of holes drilling in GH2135 is better than 420J1.


2011 ◽  
Vol 15 (9) ◽  
pp. 966-972 ◽  
Author(s):  
Andreza S. Costa ◽  
Luis C. Nogueira ◽  
Venézio F. dos Santos ◽  
Terezinha R. Camara ◽  
Vivian Loges ◽  
...  

The postharvest conservation of cut Heliconia flowers is an important factor to the success of commercialization, especially with regard to exportation. In the present study, the maximal storage time of cut inflorescences of Heliconia bihai cv. Lobster Claw at two different temperatures (12 and 19 °C) was evaluated and compared to laboratory conditions (25 °C, control treatment). Changes in visual quality, fresh weight and bract color (L*, a* and b*) were determined. The visual quality of the inflorescences and fresh weight decreased with time in all treatments. Symptoms of chilling injury were observed on the inflorescences stored at 12 °C for six and eight days. Bract color was not affected by temperature, storage time or the senescence process. The results indicate that a temperature of 12 °C is not recommended for a storage time longer than four days, whereas 19 °C can be used for a storage time of up to eight days for cut inflorescences of H. bihai cv. Lobster Claw.


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