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  • Autos: transfer case

    With a 4WD vehicle, one might hear about the transfer case. What is a transfer case, and what does it do?

    The following is by my understanding.

    A couple of lifetimes ago, I took a heavy-duty pre-app course, ten months. Until then, I’d spent my life in the academic world. I learned a great deal in that heavy-duty pre-app program.

    Yet, from any course one takes, there might be leftovers – things one didn’t quite catch, but partially recalls. For me, one topic from the heavy-duty pre-app course was transfer cases.

    A transfer case conveys power to the end of the vehicle where it’s optional. Therefore, a typical 2WD vehicle wouldn’t have a transfer case, but just an engine, transmission, then differential.

    With a 4WD, the transfer case contains what one might call a pressure plate that turns with the output shaft to the permanent driving axle. The optional driving axle, via a clutch (that’s what I’d call it), can be shifted into contact with said pressure plate. Then, 4WD mode is accomplished.

    The fact that it’s a clutch-type connection that actuates 4WD explains to me why, on the vehicles I’m familiar with, one can launch into 4WD while already driving.

    Source:

    YouTube: Engineering Explained (May 2, 2012). “Transfer Case – Explained.” https://www.youtube.com/watch?v=K1qj8dHTmP4&t=1s

    -js

  • Windows: virus scan looping

    Sometimes a virus scan might loop over a section of files and stop making progress.

    A few days back someone brought me a computer that had started as Windows 10, then updated to Windows 11. Now, after perhaps five years, it was very slow, they claimed. I powered it on for examination.

    Their computer wasn’t as slow as some I’ve seen, that’s for sure. Yet, apparently it had been much faster in the past.

    Asking them about programs they use or not, I uninstalled a lot. It seemed this computer had been with them through various periods while they had pursued diverse projects. The device showed one or two behaviours which seemed a little dodgy, but its antivirus suite, which was still in force, seemed content enough.

    After I’d done enough to hopefully improve the computer’s performance, I started a full virus scan. Yet, awhile later it started looping: it would mention files it was examining, then a minute later mention the same ones.

    I had looked earlier at the temporary files, but there didn’t seem enough to cause much issue. I wondered, now, if they contained problem files that were causing the loop. I decided to clear them out.

    Yet, when I tried to remove the temporary files, the same looping idea seemed to happen again: the computer seemed frozen at a certain point. I restarted it, then resumed the same operation.

    This time, the computer was able to purge the temporary files. Afterwards, I ran a full system scan which worked briskly.

    This wasn’t the first time I’d encountered a problem in the middle of removing some temporary files, so had to restart the computer and then the removal process.

    I think it’s probably good to remove temporary files (that one doesn’t need anymore) at least twice a year from a Windows PC. Moreover, the Windows computers I use, I do a fresh install of them every two years or so.

    After I returned the computer, its owner told me it was much faster, so I guess it worked out all right:)

    -js

  • Military: armoured vehicle purchase

    When it comes to defence spending, a price tag can catch attention.

    The following is by my understanding.

    I read recently the article “Carney announces made-in-Canada armoured vehicle deal worth nearly $2B.” (July 16, 2025, Canadian Press.)

    The article seems to suggest purchase of 190 vehicles for “nearly $2B.”

    Let’s imagine, just for round figures, the deal is two billion for two hundred vehicles. Well, two billion has nine zeros, while two hundred has two. So, the price per vehicle is 1 followed by seven zeros, or ten million.

    Perhaps I’ve missed something, but as I see it, ten million seems perhaps a lot for an armoured vehicle.

    Interesting, eh?

    -js

  • Biotech: what is an agonist?

    Sometimes one hears about agonist drugs. What are they, and how do they work?

    The following is by my understanding.

    In biology, an agonist is a molecule that mimics another one the the cell is expecting. The agonist, when it lands at the receptor site it’s designed for, will cause the cell hosting that site to react in some predictable way.

    GLP-1 agonists include Ozempic, for instance. In this case, GLP-1 refers to the hormone the agonist is mimicking. GLP-1 is made by the body and stimulates insulin release. It also slows the pace of food through the digestive system, so digestion takes longer. Moreover, it causes the person to feel full as a result of eating.

    Therefore, if one takes a GLP-1 agonist such as Ozempic, the intention is that one will experience increased insulin release, slower digestion, and a greater feeling of fullness after eating. The idea behind such a prescription is that the body isn’t releasing as much GLP-1 as would be optimal, so the agonist tops up the effective supply in order to achieve the same results as if the body simply produced more GLP-1 on it own.

    Source:

    drugsandalcohol.ie/glossary/info/agonist

    my.clevelandclinic.org

    -js

  • Autos: 10w30

    10w30 motor oil was common when I was a kid. Why does it seem not so anymore?

    The following is by my understanding.

    When I was a kid I had a Honda 50 minibike. My understanding was that it took 10w40 motor oil. I knew some people who interpreted the manual a different way, so used 10w30 with theirs. “That means it acts like 10 weight when it’s cold, but 30 weight when it’s hot,” somebody said. Even at age 11, with no hands-on experience with engines, it made sense to me.

    Decades later, I drove a (used) sedan that took 10w30 oil. I recall hearing 10w30 mentioned a lot by car people, in connection with their used 70s and 80s cars.

    Nowadays, the lawn mower I use takes 10w30, but the vehicles we drive, both from the 20-teens, take 5w20. Sometimes I wonder what happened to 10w30, vehicle-wise.

    I have realized for awhile that thinner oils go along with smaller tolerances, so the oil can get into the smaller spaces.

    Yet, another idea I wasn’t thinking of is that a thicker oil is harder for the engine to circulate. Therefore, another reason manufacturers are going to thinner oil is to ease its motion throughout the engine.

    Interesting, eh?

    Source:

    classichonda50saustralia.com.au

    Jiffy lube of Indiana (Feb 15, 2021). “The Evolution of Motor Oil: Why 10W30 Is No Longer the Most Popular Choice.” https://jiffylubeindiana.com/vehicle-maintenance/the-evolution-of-motor-oil-why-10w30-is-no-longer-the-most-popular-choice

    -js

  • Windows: what is the Windows Registry?

    Sometimes a person using Windows might be presented the idea of a Registry issue. What is the Windows Registry?

    The following is by my understanding.

    The Windows Registry is a database that contains each user’s preferences as well as privileges. Therefore, when one wants to open a certain file, the Windows operating system may check the Registry to see if said user even has access to that file. If they do, the Registry might indicate which program to use to open it. The Registry may also contain the default path where said program will store files created while using it. That’s to my mind, what the Windows Registry contains: preferences, privileges, and defaults.

    The Windows Registry is mainly a legacy fixture from the home user’s point of view. Moreover, it seems to me that “broken” or otherwise imperfect entries in the registry don’t necessarily affect computer performance. The registry may contain leftovers from uninstalled programs, for instance. Said entries may never be visited again, but that won’t matter to the user.

    Information I’m noticing on the Internet suggests the home user should leave the registry alone. If, eventually, a Windows computer gets slow, one can just do a fresh re-install of Windows. I’ve done it, and was very happy with the result. On the other hand, I can’t recall editing the Windows Registry.

    Source:

    learn.microsoft.com: Windows registry information for advanced users

    YouTube: Windows, computers, and Technology. “Stop worrying about cleaning the Windows registry just leave it alone.” (Dec 21, 2021).

    YouTube: Ask Leo! “Why Doesn’t Microsoft Dump the Registry?” (July 20, 2024).

    -js

  • Energy, hardware, household technology: how long can a lead-acid car battery last unused?

    This article’s focus is lead-acid car batteries: “battery”, “car battery”, or “lead-acid battery”, herein, means lead-acid car battery.

    The following is by my understanding.

    One might hear of a person taking a car for a drive to top up its battery, or that car batteries go dead sitting on the shop floor.

    A lead-acid battery should always be charged to full before being stored. In such a case, it can sit idle for perhaps 90 days before it needs to be checked and potentially recharged. Permanent loss of capacity may happen if left longer.

    In the case of a new battery, nine months seems to be the latest one can wait before putting it to regular use. The less fresh it is, the less storage a lead-acid battery can endure. Lead-acid batteries constantly lose capacity during storage.

    Although it’s always worth checking before giving up on a stored lead-acid battery, I’d say that if it wasn’t fully charged when put into storage, one can’t count on it starting a car after three months.

    Source:

    dxiang (Apr 26, 2022). “How to Properly Store Vehicle Batteries.” https://www.midtronics.com/blog/how-to-properly-store-automotive-batteries/

    -js

  • Computer constructs: what is a virtual machine?

    One often hears about virtual machines. What are they, and why would one need one?

    The following is by my understanding.

    A virtual machine acts like a computer inside another computer. It has its own operating system, which can be different from that of the computer it’s running on. For instance, on a virtual machine, one can run Linux on a Windows PC. Or, one can run Windows XP on a Windows 11 PC.

    The reason for the versatility of virtual machines is that one first loads the software to run virtual machines in general. In many cases, said software is open source. Then, once said software is loaded, one can pick from a list the operating system one wants, and even how much ram, CPU power, and disk space for it. One has to download an image of the operating system desired, but in my understanding many are available, including proprietary, older ones such as Windows XP.

    I’ve created virtual machines to run Linux on a Windows PC, but not the other way around – yet. However, I do have an old scanner compatible with Windows XP. It seems possible I could install virtual machine software on this Linux PC, then download an XP iso file and install XP to a virtual machine. I haven’t gotten around to it yet, but it’s on the list. Otherwise, the scanner will need to be recycled.

    Source:

    Buchanan, Ian (2026). “Containers vs Virtual Machines.” Atlassian.com. https://www.atlassian.com/microservices/cloud-computing/containers-vs-vms

    azure.microsoft.com: “What is a Virtual Machine?

    docs.oracle.com

    -js

  • Household technology: Alien Tape

    Alien Tape is a beloved product to me. Here is one use I found for it.

    Many years ago we bought Alien Tape at an “As Seen on TV” store. Its potential was instantly recognizable. We brought it home, then set it aside. The kids were young then, so life was busy. I forgot about the Alien Tape.

    Years later, I stumbled upon the Alien Tape when I was looking for something else. I couldn’t recall buying it, but knew it would come in handy. This time I put it in a place where I would keep noticing it.

    Nearly fifteen years ago we got a new roof installed: a metal one. I didn’t know until afterwards that it’s very slippery to walk on, compared with an asphalt shingle one. While the roof is great, doing maintenance that I once did easily standing on the asphalt shingles has become much more difficult – perhaps until yesterday.

    I had to wash some second-floor windows that are in a gable, so not easily reached from a ladder. They are convenient to reach from the first-storey roof in front of them, but once again that’s the metal roof which is slippery, even when dry. I know that might sound hard to believe, but it’s true. I’ve been in dry clothes on the dry roof, and started sliding down. Walking on it, as-is, is hazardous.

    So, I had to wash these second-storey windows from the first-storey roof, but how? Yesterday I found a solution: Alien Tape, which is two-sided. I used it to fasten down some rubber mats on the roof. The mats were various kinds; I made a patchwork walkway of them by taping them to the roof with Alien Tape. I think my neighbours thought it was crazy, but I’m sure it just confirmed their ideas about me.

    I was able to wash the windows, and here I am, still in one piece – thanks to Alien Tape.

    PS: Presently, I don’t get any endorsements on this site; when I mention a product it’s because I like it:)

    Source:

    alientape.ca

    -js

  • Networks: modem vs router vs gateway

    Typically, internet service in a home comes through a box. What do modem, router, and gateway mean?

    The following is by my understanding.

    A modem connects your home network to the Internet and handles the signal conversion between the two. A single PC, just by itself, could connect to the Internet with just a modem.

    A router is needed when more than one device needs access to the same Internet service. So, in a home network, if there are wireless devices (with perhaps some others wired in as well) that are all using the Internet, that’s facilitated by a router. The router manages the traffic, making sure each device behind it gets the signals relevant to its own conversation.

    A gateway is a combination of a modem and router.

    If a firewall is operating between the Internet and the home devices, said firewall is operated by the router, since it can see which traffic is heading from where and to where.

    Source:

    Knerl, Linsey (May 28, 2024). “Modem vs. Router: What is the Difference?” hp.com

    -js