Wear - Science topic

Hello Malcolm Nobre .

Thank you for your effort and help. You gave me a lot of great tips that I will put into consideration and practice.

Thanks, Douaa Arrouk . I really appreciate! If I run into trouble when it comes trying these analyses in R, could I send you a message for help? I plan to start these projects sometime next summer.

Thanks again!

Regards,

Miguel

I'm very interested!

To find the sliding distance in Abaqus for the Archard wear law:

To analytically calculate wear and service life of polymer-polymer sliding pairs: Use Archard's wear equation as a base, incorporating the wear coefficient, load, and material properties. Account for factors like contact pressure, PV factor, temperature effects, and environmental conditions. Calculate expected wear over time and compare it to the maximum allowable wear to determine service life.

Looks like it.

Singh B, Mulik R, Harsha S. Dynamic response analysis of functionally graded gears. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications. 2023;237(1):52-69. doi:10.1177/14644207221101694

Hello Viviane, thank you for your message. I'll contact you via email to discuss further.

I am looking for a place to buy used eye tracker glasses or screen-based eye tracker, any ideas?

The size of coronavirus particles, specifically those of SARS-CoV-2 which causes COVID-19, is typically in the range of approximately 60 to 140 nanometers (nm) in diameter. To understand how masks can be effective against these tiny particles, it's important to consider the nature of both the virus and the masks.

In summary, masks are effective in reducing the spread of COVID-19 because they are designed to filter out respiratory droplets, which are much larger than individual virus particles and are the primary vehicle for virus transmission. They allow for the passage of oxygen and carbon dioxide, ensuring that wearing a mask does not impede normal breathing.

l Reviewing the protocols listed here may offer further guidance in addressing this issue.

Paresh Chandra Ghosh do you have any references to this direct correlation that rubber boots reduces performance as compared to lace up work boots?

no

Over 50 uses is pretty good to be honest! I believe the way it works is when you deposit the silane on the Si wafer, you deposit a thin layer that is covalently bound to the wafer and all the layers that deposit on top of that are just loosely deposited. When you pour PDMS on it the PDMS is able to set and come-off easily since it is touching the loose silane layer and not the covalently bound layer. As you consume the loose layers by molding more and more PDMS you eventually reach the covalently bound layer and at this point the PDMS is able to permeate the layer and also form a stronger adhesion to the wafer surface. (This is my educated guess and not something I tested)

I recommend that you try increasing the deposition time of the silane to achieve higher thickness of that loose layer and perhaps that will give you increased number of PDMS molding cycles. Let me know if you try it! :)

Dear Poh King, Salman Khan's "The One World Schoolhouse: Education Reimagined" and Gatto's "Weapons of Mass Instruction: A Schoolteacher's Journey Through the Dark World of Compulsive Schooling" books will answer your questions on this subject.

o calculate the wear volume using white-light interferometer data, you can follow these steps:

Here's a simplified formula for the wear rate (WR):

WR=WearVolume/WearTime​

Where:

It's essential to ensure that the interferometer data is accurately calibrated, and the measurement uncertainty is accounted for in your calculations. Additionally, the quality of the data processing and integration will significantly impact the accuracy of your wear volume and wear rate calculations. It's a good practice to repeat measurements and verify your results to ensure consistency and reliability in your wear analysis.

OK, but answer to my questions about the content of my abstract: "Here are the title and abstract. What do you think? Any comments?"

In a friction couple, the hardness of components is one of the most important influencing factors. The increase in temperature can decrease the hardness of one or both of the contacting surfaces, which can cause increased wear. In addition, when the temperature increases, the wear mechanism can change from abrasive to adhesive wear, which can lead to a sudden increase in wear. Another factor affecting wear and friction is surface oxidation. The higher the temperature, the more the contacting metallic surfaces oxidize and the thicker the oxide layers. Depending on the alloy composition, oxidation can have different effects on friction.

Tool wear affects surface roughness and dimensional accuracy in high-speed machining of titanium alloys because wear leads to tool wear flutes, which is when the tool’s cutting edge becomes dull and rounded. This reduces the cutting efficiency and leads to an increase in surface roughness. In addition, tool wear also leads to a decrease in dimensional accuracy due to the inability of the tool to cut as precisely as it once did.

I’m surprised that acupuncture didn’t help. Keep in mind that this is not a treatment recommendation but just a comment from personal 20-year-long professional experience as an acupuncturist. Here is what I do with patients with “neuropathy”: first, carefully examine what causes the symptoms. Oftentimes, the diagnosis is established purely from tests and, fortunately, does not reflect the reality. If the patient doesn’t have wounds that don’t heal on his or her toes, the toes are not red and/or red and/or swollen, has no sensation in toes, the toes are much darker than the proximal to them skin, and the main complaint is periodic tingling and/or numbness, then look over the feet. You should be able to notice any even slight difference in color or swelling. Then gently palpate the boundaries of the swelling—and I mean very slight swelling. You should be able to feel with your fingertips tightness along those boundaries. Acupuncture needles can be used, but so can be acupressure/tui na. Using your fingertips, you can massage proximally (in the direction of the patient’s heart) across those boundaries in soft tissues. Your goal is to gently stretch the soft tissues that form that tightness in the boundaries after which the circulation and nerve signal transmission is impaired. After a few minutes, the patient usually reports warms extending to his or her toes—this means that you found the cause of the symptoms. This treatment, if it works, would need to be repeated once every day for three days, then every other day for the next three days, then two and then one time a week, until the symptoms stop returning. I hope this helps.

It is not recommended to try to increase body temperature through the thyroid pathway by increasing iodine uptake or any other means, especially without proper medical supervision. While the thyroid gland does play a role in regulating body temperature, it is just one of many factors that influence thermoregulation. Additionally, the thyroid gland is a very sensitive organ and can be easily disrupted by changes in iodine intake or other factors.

In situations where fuel is not available and individuals need to stay warm, it is important to focus on other methods of staying warm such as wearing thick clothing, using blankets, staying active to generate body heat, and using other heating sources if available. It is also important to be aware of the risks of hypothermia and take steps to prevent it, such as staying dry and avoiding prolonged exposure to cold temperatures. In extreme situations, seeking medical assistance or relocating to a warmer environment may be necessary.

Ideas coming to mind:

You can use some of the packages Wolfram Mathematica, MatLab, Maple.

Kindly refer this article and cite.

Kindly refer this paper.

Yes, you should include your control group when doing any analysis because you will want to know if there is a difference between the control group and the experimental conditions. For example, you would have no way of knowing if having a bare hand is different than wearing an oversized glove. By including your control group it allows you to statistically determine if there is (or is not) a difference.

You could still use a two-way ANOVA with your questions, though. Here is what I would do (use your judgment for your own research)

1). Glove fit + surgeon status as predictor of sensitivity

This will give you a comparison of is a surgeon with no gloves has different sensitivity compare to non-surgeons who have over-fitted gloves, etc.

2). Will be taken care of in the above analysis. When you run your two-way ANOVA, be sure your analysis will report interaction effects and multiple comparisons.

3). This will also be taken care of in the first analysis.

A two-way ANOVA with interaction effects and multiple comparisons will report if there is a difference between surgeons and non-surgeons' sensitivity while wearing gloves of different thicknesses.

I hope this helps.

No, the pin of the indenter was not broken.

A single indenter was used.

What would be the answer if hard particles were embedded in the matrix?

Thanks for clarifying the question. Thus, we are talking about an aggressive gas mixture (flue gases?) containing abrasive particles (dust?). If you mean waste incinerators and products of combustion of fluorine- and chlorine-containing plastics, then the issue of corrosion is solved by spraying quicklime in the furnace, which binds HF and HCl into low-aggressive fluoride and calcium chloride. In addition, ammonia is sprayed into the cold part of the incineration plant, which binds acid residues into the ammonium salts. If it were not for the chemical neutralization of chlorine and hydrogen fluoride, then no material would have withstood such an aggressive gas environment.

The materials of the furnace and pipe walls themselves do not differ in particular corrosion resistance to the above gas mixture and break down rather quickly, which is one of the main problems of waste incineration. This problem does not currently have a good enough solution. To increase the corrosion resistance of the refractory walls of the furnace, silicon carbide is added to the refractory cement, and a layer of Inconel 625 nickel alloy is welded onto the steel pipes of the walls and the heat exchanger. The nickel alloy layer significantly increases the service life of steel pipes, but this layer is also gradually destroyed.

To date, the best solution for protecting steel pipes of waste incinerators from corrosion and abrasive wear is a coating of self-fluxing NiCrBSi alloy, which is applied to them by thermal spraying followed by fusion.

For civil engineering applications, researchers have used them as a partial replacements for fine or coarse aggregate in the concrete mix. It is called rubberized concrete for those including rubber in the mix. the latest review can be found here:

Also, it has already been used with asphalt for road pavement.

Hello Sophie,

If the aim is to classify an individual, then the result is either that the person's posture either meets or does not meet the recommended standard, based on the collected observation data. It's a classification, not a statistical test per se.

If the aim is to make a statement about the "typical individual," and your data set is the resultant classification of many such persons,

then you can test hypotheses such as:

Ho: At least 60% of persons will meet the recommended standard (the estimated proportion, combined with the confidence interval, from the binomial distribution, would serve as relevant statistical evaluation).

or

Ho: In the population, 70% of persons will meet the recommended standard. (An exact test, using the binomial distribution, would allow one to evaluate this proposition vs. the alternative that the true percent is below or above 70%).

If you've something else in mind, perhaps you could elaborate your query.

Good luck with your work.

@mohamadou Diew Thank yo so much for the explanations. A manual calculation by adding all set points of mm3 and dividing by total distance covered.

I have 2 load 10 and 40 newton. Same sliding speed for alls amples. Should i quoute specific wear rate or just wear rate

Pin on disc wear test is a comparison test. This means that this test is only useful for comparison with other (well-known) reference materials. For example, you compare your new material to a non-alloy mild steel or to a hardened carbon steel and so on. It is only important that the future application of your new material must be similar to the application of reference material. In order to compare correctly, you need the same test specimens (discs or pins) and the same test parameters for both pin on disc wear tests. The counter-body (pins or discs) must also be the same in both cases. For example, you test disc from your material and disc from a mild steel and in both cases you use hardened carbon steel pins.

As a result of the tests, you can record two quantitative characteristics: mass loss and track width/depth. Both of these features characterize the wear and tear and material with less mass loss and smaller track wins the comparison. You can also record and compare the coefficients of friction for both cases.

Check this Dataset, could be useful:

The following study suggests that prolonged use of face mask induces difficulty in breathing on exertion and excessive sweating around the mouth to the healthcare workers which results in poorer adherence and increased risk of susceptibility to infection.

The following link is also very useful: https://www.coating.co.uk/solar-panel-coating/

Dear Marilla,

If the measurement is a continuous variable, then you could use a paired (Student's) t-test.

https://en.wikipedia.org/wiki/Student%27s_t-test#Paired_samples.

Best regards,

Carl Ribaudo

Hello Alexandre,

I can recommend my article to you as an example:

Effect of Exothermic Addition (CuO - Al) on the Structure, Mechanical Properties and Abrasive Wear Resistance of the Deposited Metal During Self-Shielded Flux-Cored Arc Welding.

hello, you can find more information from Abaqus documentation. There are two practical simulations of wear.

Dear cardoso Alsamawi

Thank you so much for your response

Dear Gitesh,

the four balls form a sphere packing. Based on this you can calculate the layer thickness h = Position of the contact points. (See: http://swetzel.ch/geomgeb/kugelpack/kugelpack.html Fig 9 and 10) h/2=sqrt(2)/sqrt(3)*r

Knowing h you can calculate the circumference of the spherical cap, which ist the sliding distance for one revolution (see: https://en.wikipedia.org/wiki/Spherical_cap) U = 2Pi*a = 2Pi * sqrt(2rh-h^2).

The sliding distance of your experiment ist than resulting with known shaft speed and test time.

(please double check the formulas)

Best regards

Max

Idir Abdelhek

Thank you, sir. But I don't understand your language.

Dear Kiran, in general, there is no established relation between friction-coefficient and wear rate, but reduction in friction-coefficient means lesser resistant to relatively moving surface and as a result lesser wear rate.

The coefficient of friction and wear of the material are in no way related to each other. The fact that the wear of a material increases with an increase in the coefficient of friction does not mean at all that, at a certain coefficient of friction, all materials should wear out in the same way.

The falsity of this idea becomes obvious when considering any pair of friction from two different materials: in such a pair of friction there is a certain coefficient of friction, but the wear of the two materials occurs at different rates.

Wearing face masks is one of the essential means to prevent the transmission of certain diseases such as COVID-19. Surgical mask-wearing in Japan is has been routine practice against a range of health threats. Their usage and associated meanings are explored in Tokyo with both mask wearers and non-mask wearers. Although acceptance of COVID-19 masks is increasing globally, many people feel that social interaction is affected by wearing a mask. In addition, there are individual perceptions of infection risk, personal interpretations of responsibility and solidarity, cultural traditions and religious imprinting, and the need to express self-identity. Therefore, the significance of an in-depth understanding of the cultural and sociopolitical considerations around the personal and social meaning of mask-wearing in different contexts as a prerequisite for assessing the effectiveness of face masks as a public health measure is critical. Furthermore, improving the personal and collective understanding of citizens' behaviors and attitudes appears crucial for developing more effective health contacts about the COVID-19 or similar hereafter.

Dear Jinfeng

Watch this video, it may help you

In fact It is very frequent to think that equality means identity. But equality us about rights, not about being different in our identities. Being a man or being a woman means different identities with equal rights. So It is not a problem at all to wear different uniforms, if the curricula and the treatment are equal for both, girls and boys.

I am not sure but may I suggest that plowing may cause a burr to form on the edge of the wear scar. This displaced material is the product of wear and contributes to the wear volume measurements but since it remains attached to the test specimen, it doesn't affect weight loss.

Dear Abigail Lucas,

Yes. This is a serious problem and little is said about in the popular news media. This is an excellent research topic that could be tackled now. The impact of protective masks made of plastics on the state of contamination of the natural environment with microplastics can be large. In addition, it happens that what is specified by the manufacturer of protective masks as a single-use product after applying an appropriate cleaning technique, washing may turn out to be a reusable product. In addition, normative rules for waste segregation should be introduced, taking into account materials, including masks used to increase the level of anti-pandemic safety. This is important because the pollution of the terrestrial, marine and air environment with microplastic particles has been growing rapidly in recent years.

Best wishes,

Dariusz Prokopowicz

Recomendaciones sobre la mascarilla

Yes, they can still contract the virus and spread it

If the denture is incorrectly constructed, then it may lead to premature contacts or incorrect vertical dimension. This can affect the measurements in the CBCT or cephalogram if it recorded with the faulty denture. The following reference may be useful

John GP, Joy TE, Mathew J, Kumar VR. Applications of cone beam computed tomography for a prosthodontist. J Indian Prosthodont Soc. 2016;16(1):3-7. doi:10.4103/0972-4052.161574

I am in accordance with Piotr Kowalewski , further the hardness of pairs of similar materials may not be sufficient to determine wear in terms of material loss. It should be obvious to consider the same test conditions (speed, contact pressure, roughness, time, temperature, environment, etc.). However, it could be observed, material transfer, change of surface topographies, without loss of material, then the method of measuring wear by weight measurement would be inadequate.

Calculate the volume loss according to the geometry of the sample. If the sample is cylindrical then use this linear loss as length (pi*r2*l ). Once wear volume is calculated then wear rate and specific wear rate can be found out easily.

I am not sure if you should remove it. It could be wear debris adhered as well. It is known that wear debris can get adhered forming a glazed surface during wear tests. I think you can rather think about why it is forming the bump and then write accordingly in your manuscript.

In my opinion, it is necessary to carry out a broad explanatory work among the population, to explain the tragic consequences of not wearing a mask. Sometimes a strict punishment or reward is also beneficial.

sorry for typo '"h."

Dear Boon Peng Chang.

The wear rate is preferred because takes into account the conditions of the abrasive wear test. We can say that this indicator is preferable for comparing the results obtained with the results of other researchers. This means it is more informative.

This might be helpful. https://www.mm.bme.hu/~gyebro/files/ans_help_v182/ans_elem/Hlp_E_CONTA173.html

Serge V. Shil’ko is the degradation also related with to materials used in the welder of ultrasonic machine? I've tried to propose to my boss to start doing the study of material used in fabric face mask with fabric area density and tensile strength. But he has claimed there is issue with material used in welder part.

Thanks Richard, but I am more looking for a practical example on the number of options to compare wear across materials/tests.

Very dubious hypothesis, likely to vary from country to country to a very great extent. Not all countries associate Red and Blue as do many western countries.

Dear Ranjeetkumar S. Gupta ;

The dry sliding tests can be used to determine the wear resistance of your samples using a pin-on-disc wear tester by varying the load and speed. More details in the following reference;

It should be analyzed according to specific materials. Some materials have self-lubricating properties. When the load is increased, physical and chemical reactions will occur on the friction surface to generate solid lubrication film and reduce the friction coefficient.

Read this article:

How to choose the right statistical test?

By : Barun K Nayak and Avijit Hazra

De nada, estimada Prof. Nancy Ann Watanabe.

Se le aprecia.

It's clearly explained in the manuscript itself. Here, the necessity for hardness evaluation was grain refinement. Also, I explained at the end of the manuscript that, even though hardness increased by grain refinement, it's not influenced to the reduction in wear rate because of the delamination wear mechanism.

Thank you.

Der Dr. Neeraj Kumar Bhoi ,

I suggest you to follow the regulation ASTM G 31 – 72 (Reapproved 1999) - Standard Practice forLaboratory Immersion Corrosion Testing of Metals.

You can have a look at the following web-site: https://www.google.it/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjzncv4t6XuAhXQPsAKHYYFCuQQFjAAegQIBRAC&url=https%3A%2F%2Fwww.researchgate.net%2Fprofile%2FMohammed_Hussein_J_H_Alatia%2Fpost%2FWhat_are_the_proper_volume_and_time_period_or_intervals_for_weight_loss_measurements_for_mild_steel_corrosion_test%2Fattachment%2F5adaca994cde260d15da0e1f%2FAS%253A617723440660480%25401524288153812%2Fdownload%2FG31.pdf&usg=AOvVaw15XywHLXiXWoCULqI2Qj1y

Following the standard according to my needs (e.g. ambient temperature of a static fluid) I used, for exposure in free corrosion at different exposure times, on samples of Al alloys smaller than yours, simple beakers where I suspended the sample, inserted with an edge in a small rubber ring (minimizing the contact surface to reduce crevice corrosion phenomena) in turn tied to a fishing line held on the top of the beaker by a glass rod ...

If you need special details, let me know.

My best regards, Pierluigi Traverso.

I'm not exactly sure what of steel wire you want to investigate and what you exactl mean by wear. Maybe you should specify.

E.g. for high strength structural steel which is used to produce strands and locked cables severeal machanical parameters are usualy asssessed in the course of QA and System Quaification. First of all this is the ultimate tensile strength with verification of a minimm elongation and constriction at break in order to assure ductile behavior. Than fatigie strength at different medium load levels with subsequent tensile test. Also relaxation may be important. Another parameter which might be associated with wear resistance is the deflected tensile test.

A good starting point for might be the fib bulletin 89 (esp. table 5-2) This guideline presents also tests for final products in order to check chemical resistance or e.g. a salt fog test.

Not sure is if this is helpful for you.

Thanks, Ian Williams Goddard .

Dear Tareq Abdhilkadhim Naser Alasadi,

Yes, thanks to the SARS-CoV-2 (Covid-19) Coronavirus (Covid-19) coronavirus vaccination programs for citizens currently starting in many countries, the current wave 2 and possibly the third wave of the pandemic will expire or decrease significantly by mid-2021 at the latest. But only then remains to be seen what to do next. To what extent vaccines will help society acquire collective, social immunity. Then, only at the end of 2021, we will find out whether new, more infectious variants of the Coronavirus have not been developed and whether pharmaceutical companies will need to create new versions of the vaccine. By mid-2021, in many economies the level of economic growth will significantly increase and the expenses incurred from the state finance system will decrease in order to finance anti-crisis interventionist programs of socio-economic policies. In the next few months, much will improve, there will be a partial return to the so-called "normality", currently remotely online processes of remote work, e-learning, internet videoconferences, etc. will be changed into hybrid forms, ie partly internet and partly traditional, stationary. Services that are currently locked down will be unlocked. A lot will get better, but on the other hand, there are still many question marks that we don't know the answer to. It is hoped that in a year's time there will be answers to the many questions now being formulated. In addition, by then, there should be improvements to the anti-pandemic risk management and crisis management systems operated by central public institutions, public safety and health care institutions. In terms of this improvement, priority should be given to the public safety and health of citizens, followed by the activation of economic growth, and finally by politics, not the other way around. Anti-crisis policy within economic anti-crisis programs should not be used for the possible strengthening of state intervention and power. Even if at present the costs and financial burdens of the state finance system of these anti-crisis policies, the instruments of their additional financing (e.g. by the direct purchase of state treasury bonds by the central bank) are not fully transparently communicated to the public, and so earlier) the costs of servicing the growing public debt will increase and these costs will be passed on to society. Therefore, it is necessary to improve the anti-pandemic risk management systems and crisis management in strategic terms, i.e. in the context of long-term (long-term) planning, and not only taking into account the current, operational, short-term policy. Hopefully, this will also improve a lot in 2021.

Best regards,

Happy New Year 2021

Dariusz Prokopowicz

Much costly and slow process

Please see the link below.

In the operation and maintenance aspect, you are supposed to replace total seals. otherwise load bearing will vary from seal to seal and leads to unsatisfactory performance during operation. Some times static leak test may pass through, but this may not be true in normal operation conditions.

Contact your local distributor.

Products:

Wearing contact lenses puts you at risk of several serious conditions including eye infections and corneal ulcers. These conditions can develop very quickly and can be very serious. In rare cases, these conditions can cause blindness.

Dear Sam,

At first glance, the differences between the wear performance of two nitrided surfaces could be attributed to their phase structure (i.e. presence and size of CrN precipitates). Coarser CrN precipitates could play a crucial role in spalling. But, you should provide much more details about the second nitriding process, and also more information about the structure of two nitrided surfaces should be given.

Regards,