kenny1999

Spray it onto the surface of shoes for once after it is newly bought then it will last a lot longer right?

No any professional cleanser is needed for most sneakers right? I have been thinking about if they are really useful.

Some told me that sneakers shouldn't require any delicate cleaning because it is supposed to get dirty, inside and outside, washing with water may even wear it faster. Some said that with proper methods of cleaning which usually involves regular use of professional or special cleansers, life of sneakers will be largely extended. In fact, I think any shoe should be cleaned but I don't think that it is good to throw them into washing machines, at least, I have not and I will not risk doing this. Generally speaking, how to clean sneakers and how often should I clean them?

I think those water absorption values are not about the perfectness of the surface of the materials. It's like for the most inert compounds, there is no actual zero reaction rate, but the reaction is going to be extremely slow which makes it virtually unreactive.

Plenty of such information if you simply do a search on Google with keywords, "water absorption rate polypropylene". One example: https://omnexus.specialchem.com/polymer-properties/properties/water-absorption-24-hours#Values

Nope, I am not talking about cracks or imperfect surface, I mean scientifically there is also a very low absorption rate for kinds of impermeable materials e.g. polypropylene, glass, even if it's made and finished perfectly. How could that happen?

I understand, but for the material that we know that they are highly impermeable to water, e.g. plastic, glass, but they still have very low water absorption rate, how do those water molecules penetrate into the material?

Hi, I thought about starting a new thread but I think it's the best to continue my question and the discussion here because it's very much related. I just happen to know that everything, even if it's logically considered to be resistant to water, e.g. polypropylene, chances are it would absorb some water over time. In that case, suppose I have got some very dirty water (e.g. filled with all kinds of dirty stuff, rotted food, bacteria, or even urine etc) that stays in a polypropylene container for a very long time, would the container absorb some of those dirty water over time and make it less safe to use even if the container is later on thoroughly cleaned, washed and rinsed with kitchen detergent and water? The same question applies to other commonly used materials for dishware and cookware e.g. ceramic, stainless steel, etc.

It is kept in the original plastic bottle and it is most of the time closed with the lid, in that case, will the IPA last much longer than the stated expiry date (i.e. two years after manufactured)?

Then what could be the possible problem of expired pesticides that have broken down or oxidized? Just render useless or be bad to health?

I know that the "expiry date" or "best before" may not actually reflect that a product will actually expire after such date. In fact, how long will isopropyl for household disinfection and pesticide will usually expire to a certain extent that it is considered useless after its manufactured and put in the containers?

We often say time heals all wounds. In fact, what is the actual process and the change in our body that will make us feel so bad at a time, but after some time or a long time, we will not feel like that even if we still remember the incident that made us sad?

My clothes was obviously not dirty. If they are dirty and put into clean water, you would see the water turn pale brown after some time, but not black water. I just don't understand why after having washed the same black T-shirt for up to several tens of times, the black color still runs so greatly. Is it very common? Without any doubt, none of my clothes are really expensive so I would assume that none of them are of the highest quality. However, is it very common that the dyes on black clothes will still leave into water after the clothes having been worn and washed for many times?

I don't buy very expensive clothes but I also do not buy clothes of unknown brand or from unknown sources. My clothes are mostly bought in kinds of shops e.g. Uniqlo, Baleno, Adidas etc. I find that it happens almost always, when I put black clothes in a bowl of clean water for a few hours (before I wash them), the water will turn black to a very obvious extent, even if the clothes are not new and have been washed for many times. Why does it happen? Is it normal to black clothes made of any raw material of any kind? Or is it a sign that I am getting very low quality clothes? Or is it due to other reasons?

Without seeing a doctor, is there a general method to help with most, if not all, psychological diseases? I understand that it may not be official, I understand that it may not be clinically proved, I understand that it may not be a cure. However, I am pretty sure that I had some kinds of psychological diseases but I am not sure what it is, probably anxiety, probably obsession, probably depression, I don't know, but for all kinds of reasons, I am not able to see a doctor now. Even though that's the case, I strongly believe that I could overcome or manage by myself because I once managed, probably 15 years ago I had some kinds of psychological problems that were greatly affecting my life and living quality, which lasted for a few years, but it's finally gone, and gone for at least 10 years, and I was free and happy, without seeing a doctor or taking any medicine, but I cannot remember how I got to that point, probably it's just gone naturally, probably it just happened for no reason, I don't know. So, well, my question has been asked. Thanks for any information, ideas and comments.

How about fish oil tablets? Is it also a waste of money?

I had been coughing for three weeks, but I had no fever and no other symptom so I tried not to see a doctor or take a medicine, I avoided cold drink and fried food, I drank mostly warm or hot water, took some vitamin supplements and ate only good foods, but I wasn't able to stop the cough or relieve at all, until I took a medicine last night, bought in a nearby grocery store. I wouldn't say I have recovered totally but A LOT better, for the first time, over the last three weeks. Is it normal or does it imply that my immune system is weaker than other normal and healthy adults'? Does it also imply that vitamin supplements or good foods don't actually help one's health? As I said, I did not have fever or any other symptoms so I believed that it was not a serious illness

Thanks all above. Is it true that dishware or cookware made of wood is more likely to be unsafe after being left uncleaned, dirty (or even soaked in dirty water) for a very long time because they look like to be more porous than other materials?

There is a long story behind but since it is not related to either Chemistry or science so I am not going to explain it here. Fact is, I have a pile of dishware and cookware made of all kinds of materials commonly used for dishware/cookware e.g. ceramic, stainless steel, polypropylene, wood etc. but these dishware and cookware were dirty and had not been cleaned for at least 1 year. Some of them were soaked in dirty water and some of them were left dry but you can imagine that all kinds of bacteria and household insects should have stayed around these dishware and cookware for a long time. My question is - By common sense, I think it's still safe to use them after cleaning them up with kitchen detergent or boiling water thoroughly. But is it true? Could bacteria or dirty water or anything unwelcome be slowly absorbed into these materials because of the long time? Are these dishware and cookware still safe to use after they are cleaned? Thanks.

Wouldn't it be better to take fish oil tablets rather than wild-caught fish because many are advertised to have heavy metal removed or purified while wild-caught fish may contain some heavy metals.

Different brands, different packaging, different marketing terms, different prices, but are they more or less the same?

Yesterday, I visited a stationery section of a bookstore, for the first time after 20 years. I found that most pencils and erasers today have adverts or labels on their packaging suggesting that they are free of some kinds of chemicals (it starts with the letter P but I did not mark it down), or non-toxic, or other safety information, while 20 years ago, when I was in school, I think there was no pencil or eraser with such information. Is it because there are more regulations now or more competitions now? Or is it because some pencils and rubber are known to be hazardous? After all, since I erase a lot, and I just hate making a cross line to delete what I have written. I bought a pack of pencil and rubber by Faber-Castell. I think it is a famous brand, but surprisingly, its pencil and rubber are cheapest than many other brands that I did not even hear about.

I remember that in the past, I wrote with some ink/fountain pens that gave strange and disgusting smell, and it happened a couples of times. However, having no smell doesn't mean something is safe. Yes, life is really short. I hope I will be less obsessed for something not really important.

Yes, fountain pen. I am not actually speaking English. But I am sure the erasable pen I saw wasn't ballpoint style.

inkjet pen, pen fueled by ink. At least, not the ballpoint type. I don't know their compositions, that's why I asked. No regulation her for pens, no label on the pen. But what usually makes an inkjet pen erasable?