Fabrication and characterization of composite MoS2-TiO2 coating material

2021 ◽  
pp. 095440622110157
Author(s):  
Avinash V Borgaonkar ◽  
Ismail Syed ◽  
Shirish H Sonawane
Keyword(s):  
Bond Strength ◽  
Treatment Method ◽  
Optical Microscope ◽  
Scratch Resistance ◽  
Substrate Material ◽  
Coating Film ◽  
Tribological Behaviour ◽  
Molybdenum Disulphide ◽  
Before And After ◽  
Pre Treatment

Molybdenum disulphide (MoS2) is a popularly used solid lubricant in various applications due to its superior tribological behaviour. However, it possesses poor wear resistance which requires further improvement. In the present study efforts have been made to enhance the tribological properties of pure MoS2 coating film by doping TiO2 nanoparticles as a reinforcement material. The Manganese phosphating is selected as a pre-treatment method to improve the bond strength between coating and substrate. The coating is bonded with the substrate material employing sodium silicate as a binder. The effects of wt. % of TiO2 onto the mechanical properties of composite MoS2-TiO2 coating such as hardness and bond strength have been studied. In addition coating microstructure before and after experimental test was studied using optical microscope and scanning electron microscope. It was also found that with increase in wt. % addition of TiO2 upto 15% into MoS2 base matrix, the hardness of coating increases proportionally. Beyond 15 wt. % addition of TiO2, the coating becomes brittle in nature. This leads to reduction in the scratch resistance.

A New Pre-Treatment with Phosphoric Acid and Hydrofluoric Acid of Electroless Ni-P Plating on Mg Alloy

2015 ◽  
Vol 729 ◽  
pp. 21-26
Author(s):  
Zhi Hui Xie ◽  
Jun Li Zhou ◽  
Shu Rong Xiang ◽  
Fang Chen
Keyword(s):  
Corrosion Current ◽  
Treatment Method ◽  
Mg Alloy ◽  
Cross Sectional ◽  
Plating Bath ◽  
Pickling Solution ◽  
Before And After ◽  
The Matrix ◽  
Pre Treatment ◽  
Electroless Ni

In order to develop a chromium-free pre-treatment method for electroless Ni-P (ENP) plating on magnesium alloy from an acidic plating bath, several various pickling and activation processes were studied in the present work. The surface morphologies of the matrix before and after etching or activation as well as the surface and cross sectional appearance of the Ni-P coatings were observed by scanning electronic microscope (SEM), while the elemental compositions were detected by energy dispersive X-ray spectroscopy (EDS). Those surface characterizations along with the scribe and grid testing results showed that the coatings obtained from etching only in H3PO4 solution display poor adhesion due to the existance of an interlayer between the matrix and the coatings. When fluoride was added into the pickling solution, the adhesion of the Ni-P coatings was also unsatisfactory because of the bad mechanical interlocking. By comparison, the Ni-P coatings obtained from pickling in 400 cm3·dm−3 H3PO4 solution followed by 10 cm3·dm−3 HF activation exhibit good characteristics in both adhesion and anti corrosion. The polarization test in 3.5wt.% NaCl aqueous solution showed that the corrosion potential (Ecorr) and corrosion current density (Icorr) of the new achieved coatings increases positively from −1.65 V to −0.87 V and decreases remarkably from 2.09 mA⋅cm−2 to 3.58 μA⋅cm−2, respectively (both compared with the bare Mg alloy).

scholarly journals Potential Risk Related To The Reuse of Faecal Sludge In Agriculture: Proposal For An Ecological Treatment Method Based On Active Charcoal

2021 ◽  
Author(s):  
Arnold Landy Fotseu Kouam ◽  
Ajeagah Aghaindum Gideon ◽  
Isaac Dennis Amoah ◽  
Tsomene Namekong Pierre ◽  
Okoa Amougou Thérèse Nadège
Keyword(s):  
Treatment Method ◽  
Optical Microscope ◽  
Active Charcoal ◽  
Physico Chemical ◽  
Absorption Potential ◽  
Before And After ◽  
Ecological Treatment ◽  
Staining Techniques ◽  
Faecal Sludge

Abstract This study is aimed at highlighting the risks associated with the reuse of faecal sludge and proposed a sustainable treatment method. The sampling consisted of collecting samples of faecal sludge in 5L of sterilized containers and then transporting to the laboratory in a refrigerated chamber for the determination of helminth eggs using standard protocols. The experimental device consisted of two replicates, one test and one control. The test samples received active charcoal at different concentrations (C1, C2, C3, C4, C5, C6). The physico-chemical parameters were measured before and after treatment. The samples were then observed under the optical microscope at the 40X objective for morphological identifications. Molecular analysis was carried out using the Polymerase Chain Reaction technique. The viability of the eggs were determined using incubation and staining techniques. Analyses showed that the sludge used for irrigation contained eggs and larvae of 6 helminth species (S. stercoralis, A. duodenale, N. americanus, T. trichiuria, H. nana and Ascaris spp.) with viability percentages ranging from 57.72% to 74.46%. Treatment with active charcoal allowed significant adsorption of these parasites with yields ranging from 95 to 100%. In addition, the carbon used has favoured the alkaline stabilisation of the medium, which increases its absorption potential. It can therefore be used in the treatment of sludge because, unlike other chemical disinfectants, it does not present any toxic effects.

EELS characterization of “Smut” layer films on steel surface prepared for chrome plating by anodic etching

1995 ◽  
Vol 53 ◽  
pp. 538-539
Author(s):  
E Y. Wang ◽  
J. T. Cherian ◽  
A. Madsen ◽  
R. M. Fisher
Keyword(s):  
Steel Surface ◽  
Surface Preparation ◽  
Treatment Method ◽  
Chrome Plating ◽  
Transmission Electron ◽  
Alloy Steels ◽  
Pre Treatment ◽  
Hard Chrome ◽  
Electron Energy Loss

Many steel parts are electro-plated with chromium to protect them against corrosion and to improve their wear-resistance. Good adhesion of the chrome plate to the steel surface, which is essential for long term durability of the part, is extremely dependent on surface preparation prior to plating. Recently, McDonnell Douglas developed a new pre-treatment method for chrome plating in which the steel is anodically etched in a sulfuric acid and hydrofluoric acid solution. On carbon steel surfaces, this anodic pre-treatment produces a dark, loosely adhering material that is commonly called the “smut” layer. On stainless steels and nickel alloys, the surface is only darkened by the anodic pre-treatment and little residue is produced. Anodic pre-treatment prior to hard chrome plating results in much better adherence to both carbon and alloy steels.We have characterized the anodic pre-treated steel surface and the resulting “smut” layer using various techniques including electron spectroscopy for chemical analysis (ESCA) on bulk samples and transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) on stripped films.

Cytoprotective Effect of Tocotrienol-Rich Fraction and α-Tocopherol Vitamin E Isoforms Against Glutamate-Induced Cell Death in Neuronal Cells

2014 ◽  
Vol 84 (3-4) ◽  
pp. 0140-0151 ◽  
Author(s):  
Thilaga Rati Selvaraju ◽  
Huzwah Khaza’ai ◽  
Sharmili Vidyadaran ◽  
Mohd Sokhini Abd Mutalib ◽  
Vasudevan Ramachandran ◽  
...  
Keyword(s):  
Vitamin E ◽  
Cell Viability ◽  
Neuronal Cells ◽  
Positive Control ◽  
Post Treatment ◽  
Mitochondrial Activity ◽  
Before And After ◽  
Pre Treatment ◽  
Tocotrienol Rich Fraction ◽  
Major Mediator

Glutamate is the major mediator of excitatory signals in the mammalian central nervous system. Extreme amounts of glutamate in the extracellular spaces can lead to numerous neurodegenerative diseases. We aimed to clarify the potential of the following vitamin E isomers, tocotrienol-rich fraction (TRF) and α-tocopherol (α-TCP), as potent neuroprotective agents against glutamate-induced injury in neuronal SK-N-SH cells. Cells were treated before and after glutamate injury (pre- and post-treatment, respectively) with 100 - 300 ng/ml TRF/α-TCP. Exposure to 120 mM glutamate significantly reduced cell viability to 76 % and 79 % in the pre- and post-treatment studies, respectively; however, pre- and post-treatment with TRF/α-TCP attenuated the cytotoxic effect of glutamate. Compared to the positive control (glutamate-injured cells not treated with TRF/α-TCP), pre-treatment with 100, 200, and 300 ng/ml TRF significantly improved cell viability following glutamate injury to 95.2 %, 95.0 %, and 95.6 %, respectively (p < 0.05).The isomers not only conferred neuroprotection by enhancing mitochondrial activity and depleting free radical production, but also increased cell viability and recovery upon glutamate insult. Our results suggest that vitamin E has potent antioxidant potential for protecting against glutamate injury and recovering glutamate-injured neuronal cells. Our findings also indicate that both TRF and α-TCP could play key roles as anti-apoptotic agents with neuroprotective properties.

EVALUATION OF TRIBOTECHNICAL PROPERTIES OF THE COATING OBTAINED BY ELECTRIC SPARK HARDENING

2020 ◽  
Vol 4 (141) ◽  
pp. 157-163
Author(s):  
IL’YA ROMANOV ◽  
◽  
ROMAN ZADOROZHNIY
Keyword(s):  
Wear Resistance ◽  
Reference Sample ◽  
Optical Microscope ◽  
Research Purpose ◽  
Tribotechnical Properties ◽  
Uncoated Surface ◽  
Before And After ◽  
Materials Used ◽  
Friction Track

When applying coatings using various methods on the surfaces of moving parts that work in joints, it is important to make sure that the coatings are strong and wear-resistant in order to return them to their original resource. All existing hardening technologies and materials used to perform coatings have their own characteristics, therefore, the quality of the resulting coatings can be judged only after specific tests. (Research purpose) The research purpose is in evaluating the properties of the coating obtained by the method of electric spark hardening, and its ability to resist friction and mechanical wear. (Materials and methods) Authors conducted tests on the basis of the "Nano-Center" center for collective use. A coating was applied on the BIG-4M unit with a VK-8 hard alloy electrode, tribological properties were evaluated on a CSM Instruments TRB-S-DE-0000 tribometer, the width of the friction track was measured after the test using an inverted OLYMPUS gx51 optical microscope, and samples were weighed before and after the test on a VLR-200 analytical balance. Conducted research in accordance with GOST 23.224-86 and RD 50-662-88 guidelines. (Results and discussion) The article presents performed tests on the run-in and wear resistance of the coating. The samples were worked on with a step-by-step increase in the load. During the tests, the friction force was drawed on the diagram. Authors compared the results with the reference sample, an uncoated surface. (Conclusions) The resulting coating has better run-in and wear resistance compared to the standard, and the increase in wear resistance in dry friction conditions is very significant.

scholarly journals Recent advances in characterizing the “bee” structures and asphaltene particles in asphalt binders

2020 ◽  
Vol 13 (6) ◽  
pp. 697-706
Author(s):  
Yuhong Wang ◽  
Kecheng Zhao ◽  
Fangjin Li ◽  
Qi Gao ◽  
King Wai Chiu Lai
Keyword(s):  
Near Field ◽  
Asphalt Binder ◽  
Optical Microscope ◽  
Asphalt Binders ◽  
Zero Shear Viscosity ◽  
Surface Features ◽  
Asphaltene Content ◽  
Scanning Transmission ◽  
Before And After ◽  
Binder Aging

AbstractThe microscopic surface features of asphalt binders are extensively reported in existing literature, but relatively fewer studies are performed on the morphology of asphaltene microstructures and cross-examination between the surface features and asphaltenes. This paper reports the findings of investigating six types of asphalt binders at the nanoscale, assisted with atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM). The surface features of the asphalt binders were examined by using AFM before and after being repetitively peeled by a tape. Variations in infrared (IR) absorbance at the wavenumber around 1700 cm−1, which corresponds to ketones, were examined by using an infrared s-SNOM instrument (scattering-type scanning near-field optical microscope). Thin films of asphalt binders were examined by using STEM, and separate asphaltene particles were cross-examined by using both STEM and AFM. In addition, connections between the microstructures and binder’s physicochemical properties were evaluated. The use of both microscopy techniques provide comprehensive and complementary information on the microscopic nature of asphalt binders. It was found that the dynamic viscosities of asphalt binders are predominantly determined by the zero shear viscosity of the corresponding maltenes and asphaltene content. Limited samples also suggest that the unique bee structures are likely related to the growth of asphaltene content during asphalt binder aging process, but more asphalt binders from different crude sources are needed to verify this finding.

Evaluation of Changes in Depression Levels of Bruxism Patients Treated With Botulinum Toxin-A

2021 ◽  
pp. 232020682110065
Author(s):  
Deniz Erdil ◽  
Nilsun Bagis ◽  
Hakan Eren ◽  
Melike Camgoz ◽  
Kaan Orhan
Keyword(s):  
Botulinum Toxin ◽  
Botulinum Toxin A ◽  
Age Groups ◽  
Treatment Method ◽  
Definitive Treatment ◽  
Toxin A ◽  
Physiological Factors ◽  
Before And After ◽  
The Mean ◽  
Post Hoc

Aim: Bruxism is defined as the involuntary recurrent masticatory muscle activity characterized by gnashing, grinding, clenching of teeth, and/or pushing the mandible. Factors creating its etiology are peripheral (morphological) or central (physiopathological and physiological), and exogenous. Recently, among physiological factors, depression and bruxism were considered to be related. A definitive treatment method does not exist for bruxism; however, botulinum toxin-A (BT-A) application is an up-to-date and effective way of treatment. The present study is aimed to evaluate the levels of depression in bruxism patients treated with BT-A application. Materials and Methods: A total of 25 individuals (23 females and 2 males) who were diagnosed as bruxism patients were included in the study. 25 U of BT-A for each masseter muscle was injected into the patients. Patients were prospectively observed for a possible change in depression levels by using Beck’s Depression Inventory. The inventory was implemented before and six months after the BT-A application. Depression levels before and six months after the injection were compared. A paired t-test was used to compare “before” and “after” treatment values. One-way analysis of variance and post-hoc Tukey tests were used to evaluate the change in Beck’s Depression Inventory scores according to age groups. Results: The mean total score was 7.80 ± 8.10 before the treatment and 7.16 ± 6.52 six months after the treatment. The decrease in the mean score was not statistically significant ( P > .05). Conclusion: In conclusion, despite the decrease in the mean Beck’s Depression Inventory scores, a statistically significant decrease in the depression levels of patients was not observed.

scholarly journals Transcriptomic analysis identifies differences in gene expression in actinic keratoses after treatment with imiquimod and between responders and non responders

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Megan H. Trager ◽  
Emanuelle Rizk ◽  
Sharon Rose ◽  
Kuixi Zhu ◽  
Branden Lau ◽  
...  
Keyword(s):  
Gene Expression ◽  
Squamous Cell Carcinoma ◽  
Distinct Pattern ◽  
Study Endpoint ◽  
Inflammatory Gene Expression ◽  
Immune Modulators ◽  
Actinic Keratoses ◽  
Before And After ◽  
Pre Treatment

AbstractThe presence of actinic keratoses (AKs) increases a patient’s risk of developing squamous cell carcinoma by greater than six-fold. We evaluated the effect of topical treatment with imiquimod on the tumor microenvironment by measuring transcriptomic differences in AKs before and after treatment with imiquimod 3.75%. Biopsies were collected prospectively from 21 patients and examined histologically. RNA was extracted and transcriptomic analyses of 788 genes were performed using the nanoString assay. Imiquimod decreased number of AKs by study endpoint at week 14 (p < 0.0001). Post-imiquimod therapy, levels of CDK1, CXCL13, IL1B, GADPH, TTK, ILF3, EWSR1, BIRC5, PLAUR, ISG20, and C1QBP were significantly lower (adjusted p < 0.05). Complete responders (CR) exhibited a distinct pattern of inflammatory gene expression pre-treatment relative to incomplete responders (IR), with alterations in 15 inflammatory pathways (p < 0.05) reflecting differential expression of 103 genes (p < 0.05). Presence of adverse effects was associated with improved treatment response. Differences in gene expression were found between pre-treatment samples in CR versus IR, suggesting that higher levels of inflammation pre-treament may play a part in regression of AKs. Further characterization of the immune micro-environment in AKs may help develop biomarkers predictive of response to topical immune modulators and may guide therapy.

scholarly journals The effect of drying temperature on the properties of gelatin from carps (Cyprinus carpio) skin

2019 ◽  
Vol 37 (No. 4) ◽  
pp. 246-251 ◽  
Author(s):  
Joanna Tkaczewska ◽  
Maciej Wielgosz ◽  
Piotr Kulawik ◽  
Marzena Zajac
Keyword(s):  
Cyprinus Carpio ◽  
Freeze Drying ◽  
Treatment Method ◽  
Thermal Hydrolysis ◽  
Gel Properties ◽  
Drying Temperature ◽  
Freeze Dried ◽  
Different Temperatures ◽  
Pre Treatment ◽  
Hydrolysis Of

The influence of drying temperature on the characteristics and gel properties of gelatine from Cyprinus carpio L. skin was studied. Gelatine was extracted from the carp skin using NaOH and ethanol pre-treatment method, extracted in water in 45°C and then dried in 4 different temperatures: 50, 70, 80°C and freeze-dried. The  electrophoresis and functional properties of gelatines were investigated. Freeze drying allowed to obtain a high gelling force, and all other methods did not give satisfactory results. The proteins in gelatines dried at higher temperatures separated by electrophoresis gave severely blurred bands. It may be explained by thermal hydrolysis of collagen fibrils. Freeze drying is the only effective method for drying this product, which can be used in industry.

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