scholarly journals Corrosion Resistance of Ti-6Al-4V Machined Surfaces Improved by Thermal Oxidation

2020 ◽  
Vol 24 (5) ◽  
pp. 185-193
Author(s):  
Carolina Aurélia Ribeiro Maestro ◽  
Marina Cristina Ferreira ◽  
Alysson Helton Santos Bueno ◽  
Artur Mariano de Sousa Malafaia
Keyword(s):  
Corrosion Resistance ◽  
Thermal Oxidation ◽  
Body Fluid ◽  
Vickers Microhardness ◽  
The Other ◽  
Machining Parameters ◽  
Before And After ◽  
Economical Process ◽  
Better Than ◽  
Machined Surfaces

Ti-6A-l4V alloy is widely used in implants and prosthesis applications. Although machining is a fast and economical process, the roughness generated can compromise corrosion resistance. Thus, the goal of this study was to overcome this limitation using thermal oxidation in machined surfaces. Samples with polished surfaces were used for comparison purposes. Two sets of machining parameters were used to generate different roughness, property evaluated in polished and machined samples before and after thermal oxidation. Vickers microhardness and polarization tests using simulated body fluid (SBF) were also performed. Thermal oxidation generated similar microhardness for polished and machined samples, higher than for polished and non-oxidized condition. On the other hand, oxidation increased the roughness only for polished condition. The corrosion resistance was improved in all oxidized samples, and the best result was found to the intermediate roughness (Ra = 0.76 um), in a machined sample. The results demonstrated that thermal oxidation can be used to overcome machining limitations regarding corrosion resistance, achieving behavior even better than polished samples.

Evaluation of the Bioactivity Behavior of a 48 Wt %SiO2 Bioglass through Experiments in Simulated Body Fluid

2012 ◽  
Vol 727-728 ◽  
pp. 1238-1242 ◽  
Author(s):  
Roger Borges ◽  
Antônio Carlos da Silva ◽  
Juliana Marchi
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Glass Network ◽  
In Vitro Experiments ◽  
High Corrosion Resistance ◽  
Before And After ◽  
O 19

Among bioceramics materials, bioglasses which exhibits either a bioactive or resorbable behavior has been studied for many applications, such as bone substitutive and regeneration. When in contact with body fluid, the bioglasses can induce the formation of a hydroxyapatite surface layer. In this paper, we studied the bioactivity of a bioglass containing 48 wt %SiO2, 27 wt% Na2O, 19 wt % CaO and 6 wt %P2O5. After fusion and annealing, the samples were immersed in SBF for different periods, up to 14 days. The samples were characterized through XRD, DRIFT and SEM before and after bioactivity experiments. The overall results suggest the formation of a surface layer of consisting of hydroxyapatite, which was crystallized within seven days after in vitro experiments, leading to a suitable bioactivity. Moreover, the samples showed a glass network with high cohesion due to calcium addition, leading to materials with high corrosion resistance.

Effect of Annealing on the Properties of Surface Nanocrystallized CP-Ti

2011 ◽  
Vol 695 ◽  
pp. 162-165
Author(s):  
Cong Hui Zhang ◽  
Xiao Mei He ◽  
Xin Zhe Lan ◽  
Xi Cheng Zhao
Keyword(s):  
Corrosion Resistance ◽  
Polarization Curve ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Optical Microscope ◽  
Nanostructured Surface ◽  
Before And After ◽  
Different Temperatures ◽  
Cp Ti ◽  
Better Than

Vacuum annealing was carried out for the SMAT treated CP-Ti sample at different temperatures. The structure and the properties of the SMAT sample before and after the annealing were analyzed by means of the optical microscope, hardness and polarization curve testing. The results show that, when the annealing temperature of surface nanocrystallized CP-Ti treated CP-Ti (SMAT) was below 350°C, the microstructure and hardness of nanostructured surface was stability, and its corrosion resistance was improved compared to non-annealing one. In particular, the corrosion resistance at 150°C was better than that of the original CP-Ti.

scholarly journals Testing the effectiveness of disinfectant protocols for soiled footwear

2008 ◽  
Vol 61 ◽  
pp. 384-384
Author(s):  
S.D. Young ◽  
M.R. McNeill ◽  
D.J. Saville
Keyword(s):  
New Zealand ◽  
The Other ◽  
Polysorbate 80 ◽  
Culturable Bacteria ◽  
Running Shoes ◽  
Different Types ◽  
Before And After ◽  
Bacteria And Fungi ◽  
Better Than

Footwear carried by international air travellers arriving in New Zealand is subject to inspection and if necessary cleaning and disinfecting by MAFBNZ quarantine inspectors A study to evaluate the effectiveness of disinfectant treatment was carried out on three different types of footwear (running shoes gumboots and tramping boots) cleaned following observed MAFBNZ procedure (dip) and following a 10 minute soak Two disinfectant treatments (VirkonTM and TriGene AdvanceTM) were compared with a surfactant (polysorbate 80) and water only Soles were swabbed for microbes before and after washing and culturable bacteria and fungi per cm2 were enumerated Disinfectant treatments reduced bacteria numbers by 99 compared with 98 for both water and surfactant treatments VirkonTM was the best treatment for bacteria both with the standard dip and the 10 minute soak but it was not significantly better than the other treatments Soaking also reduced bacterial numbers compared to the dip treatment but not significantly For fungi the two disinfectants surfactant and water yielded similar reductions (97) Soaking reduced fungal numbers compared to the dip treatment but this was not quite significant (P0051)

Biodegradable Behaviors in Simulated Body Fluid of Mg-Gd-Y-Zr Alloy with Micro-Arc Oxide Coating

2013 ◽  
Vol 747-748 ◽  
pp. 295-300
Author(s):  
Kai Yang Yin ◽  
Tian Feng Lu ◽  
Qing Dong ◽  
Bing Yi Sun ◽  
Bin Chen
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Oxide Coating ◽  
Volume Measurement ◽  
Before And After ◽  
Micro Arc Oxidation ◽  
Weight Loss Method ◽  
Loss Method

The effects of micro-arc oxidation (MAO) on corrosion resistance of Mg-Gd-Y-Zr magnesium alloy have been studied. The Mg-Gd-Y-Zr with thicker oxide coating presented higher corrosion resistance in simulated body fluid (SBF). The corrosion rates were measured by several methods including hydrogen evolution volume measurement, weight-loss method and determination of pH as an auxiliary reference. The surfaces of specimens were observed by SEM and white light confocal microscopy before and after the corrosion. Besides the effects of MAO, the pitting resulted from breakage of oxide coating played a notable role as well. This provided a new direction towards the enhancement of corrosion resistance of magnesium alloy.

Experimental Study on the Properties of Modified PSA Fiber after Corrosion

2011 ◽  
Vol 183-185 ◽  
pp. 1631-1634
Author(s):  
Xin Yan Yuan ◽  
Heng Gen Shen ◽  
Zhen Hua Wang
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
High Humidity ◽  
Corrosive Environment ◽  
Corrosion Condition ◽  
Optimal Value ◽  
Before And After ◽  
Proportional Relationship ◽  
Better Than ◽  
Made In

In order to improve the reliability of PSA in industrial furnaces corrosion condition, tests are made in different concentration of PTFE emulsion to modify PSA fiber, and experiments are conducted on the comparison of corrosion resistance before and after modification. The results show that: the mechanics properties of PSA fiber decline after the modification with PTFE emulsion, but the corrosion resistance is obviously improved. There will be rising phenomenon of the mechanical properties of the fiber after corrosion treatment by 15% PTFE emulsion initially. The improvement of corrosion resistance of modified PSA fiber has certain relationship with the concentration of PTFE emulsion. In alkaline corrosive environment, the corrosion resistance of modified PSA fiber has a certain proportional relationship to the concentration of PTFE emulsion. In acid corrosive environment, there exists a optimal value of the concentration of PTFE emulsion. The modified effect of the concentration of 5% and 10% PTFE emulsion is better than that of 15%. This shows that the PSA must be dealt against corrosion when used in industrial furnaces with high temperature, high humidity and the corrosion condition. Dipping with PTFE emulsion is a very effective method.

scholarly journals Research on the Ergonomic Design of Pet Dog Toothbrush Neck

2021 ◽  
Vol 275 ◽  
pp. 03038
Author(s):  
Yu Shu Huang ◽  
Cheng Qi Xue
Keyword(s):  
Oral Health ◽  
Random Sequence ◽  
Water Soluble ◽  
Experimental Results ◽  
The Other ◽  
Lower Section ◽  
Cleaning Efficiency ◽  
Tilting Angle ◽  
Before And After ◽  
Better Than

Using a toothbrush to clean the teeth for a pet dog is the best way to maintain the pet’s oral health. Meanwhile, the angle of a toothbrush neck can influence the posture and brushing strength of the pet caretaker, thereby affecting the cleaning efficiency. In order to compare the cleaning efficiency of pet dog toothbrushes with varied neck types, 20 volunteers with dog caring experience were selected. A medium-sized dog tooth model coated with water soluble pigment was provided to each volunteer, and then she/he was asked to brush the model for three minutes, using a specific type of pet dog toothbrush. Such process was repeated for each of 5 toothbrushes with varied neck types (all other elements remained the same), while different neck types were provided to each volunteer in random sequence. The pigment areas of the incisors, canines, and molars before and after tooth brushing were measured and calculated to speculate the cleaning efficiency of the toothbrush. At the end of the experiment, each subject was asked to evaluate five toothbrushes with respect to operating comfortability. The experimental results showed that the toothbrushes with backward tilting angle at the upper section of their brush necks performed significantly better than the other four groups of toothbrushes in cleaning molar and canine teeth, while the toothbrushes with backward tilting angle at the lower section, and with the upper section parallel to the brush handle were more comfortable in operation.

Comparative Study on the Mn2+ Removing Performance of Several Filters

2011 ◽  
Vol 415-417 ◽  
pp. 100-105
Author(s):  
Ji Ku Zhang ◽  
Yang Jiang ◽  
Yi Xing Yuan
Keyword(s):  
Activated Carbon ◽  
Comparative Study ◽  
Surface Characteristics ◽  
The Other ◽  
Before And After ◽  
Long Time ◽  
Ideal Filter ◽  
Better Than

The Mn2+ removing effect from groundwater by four kinds of filters——Zeolites ,Activated Carbon ,Manganese Sand and a new filter ANJ.SiC, were comparatively studied and analyzed respectively .The results show that, the Mn2+ removing effect of ANJ.SiC is significantly better than the other three .It is an ideal filter in Mn2+ removing ,which can be reused for a long time .These filters’ surface characteristics before and after saturation were compared through their SEM figures ,and the Mn2+ removing mechanism were further studied.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Kepuasan Masyarakat Terhadap Pelayanan Kelurahan Setelah Pemekaran Di Tangerang Selatan

Liquidity ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 151-159
Author(s):  
Pitri Yandri
Keyword(s):  
Public Perception ◽  
Service Personnel ◽  
Urban Services ◽  
Hospitality Workers ◽  
Care Workers ◽  
Before And After ◽  
Cartesian Diagram ◽  
Better Than

The purpose of this study is (1) to analyze public perception on urban services before and after the expansion of the region, (2) analyze the level of people's satisfaction with urban services, and (3) analyze the determinants of the variables that determine what level of people's satisfaction urban services. This study concluded that first, after the expansion, the quality of urban services in South Tangerang City is better than before. Secondly, however, public satisfaction with the services only reached 48.53% (poor scale). Third, by using a Cartesian Diagram, the second priority that must be addressed are: (1) clarity of service personnel, (2) the discipline of service personnel, (3) responsibility for care workers; (4) the speed of service, (5) the ability of officers services, (6) obtain justice services, and (7) the courtesy and hospitality workers.

MUNDANE MIRACLES IN AWADH. ENCOUNTERS WITH THE REVEALED AND THE HIDDEN

2020 ◽  
pp. 130-140
Author(s):  
Maxim B. Demchenko ◽  
Keyword(s):  
The Other ◽  
Local People ◽  
Natural Phenomena ◽  
Mughal Empire ◽  
The Public ◽  
British Raj ◽  
The Subject ◽  
Other World ◽  
Better Than

The sphere of the unknown, supernatural and miraculous is one of the most popular subjects for everyday discussions in Ayodhya – the last of the provinces of the Mughal Empire, which entered the British Raj in 1859, and in the distant past – the space of many legendary and mythological events. Mostly they concern encounters with inhabitants of the “other world” – spirits, ghosts, jinns as well as miraculous healings following magic rituals or meetings with the so-called saints of different religions (Hindu sadhus, Sufi dervishes),with incomprehensible and frightening natural phenomena. According to the author’s observations ideas of the unknown in Avadh are codified and structured in Avadh better than in other parts of India. Local people can clearly define if they witness a bhut or a jinn and whether the disease is caused by some witchcraft or other reasons. Perhaps that is due to the presence in the holy town of a persistent tradition of katha, the public presentation of plots from the Ramayana epic in both the narrative and poetic as well as performative forms. But are the events and phenomena in question a miracle for the Avadhvasis, residents of Ayodhya and its environs, or are they so commonplace that they do not surprise or fascinate? That exactly is the subject of the essay, written on the basis of materials collected by the author in Ayodhya during the period of 2010 – 2019. The author would like to express his appreciation to Mr. Alok Sharma (Faizabad) for his advice and cooperation.

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