Woda wapienna na biologię...

TL;DR:

Jeśli dziecko twierdzi, że potrzebuje do zadania domowego z biologii wodę wapienną - prawdopodobnie jest inne zadanie (zawaliło dziecko) albo nauczyciel zawalił.

Wstęp

Mój syn niedawno powiedział mi, że mają do wykonania zadanie domowe z biologii. I potrzebna jest woda wapienna.

Ja nigdy nic takiego nie miałem w szkole.
Książka to "Puls życia" 5, podręcznik do biologii dla klasy piątej szkoły podstawowej, wydawnictwo "nowa era". Zadanie na stronie 52.

O wodzie wapiennej... i innych

Woda wapienna to nasycony roztwór wodny wapnia. Albo dokładniej nasycony roztwór wodny wodorotlenku wapnia.

Wapń (Ca od łacińskiej nazwy calcium) to pierwiastek.

Wapno (CaO od łacińskich calcium oxygenium) to tlenek wapnia.

Wapno palone to właśnie CaO.

Wapno gaszone to Ca(OH)₂

Wodę wapienną otrzymamy z jednego z poniższych:

• Wapń (Ca)
• Wapno (CaO)

Niestety, te reakcje są dość niebezpieczne. Tak samo jak sama woda wapienna.

Wapno, wapń, woda wapienna - są żrące, niebezpieczne, drażniące, parzące.

Wody wapiennej raczej nie uzyskamy z wapna gaszonego.

O zadaniu domowym i dostępności produktów

Należy przeprowadzić reakcję i sprawdzić czy wydziela się dwutlenek węgla.

Do sprawdzenia należy użyć wody wapiennej.

Przygotowanie wody wapiennej jest niebezpieczne - wydziela się w tym procesie dużo ciepła i można się poparzyć.

Woda wapienna jest silnie żrąca i niebezpieczna. Dziecko nie powinno mieć do niej dostępu.

Wyjaśnienie

Po wizycie w kilku aptekach, nieudanych próbach i czytaniu... okazało się, że było inne zadanie domo9we

LOKMAT watch

Hello,

This will be a quick review of LOKMAT watch with bluetooth.
I will divide it into several parts:
- Design
- Hardware quality
- Software
- Firmware

Design
The watch looks nice on the first glance. A simple watch with bluetooth connectivity and "reversed LCD" (digits are light while background is dark).
It is not so simple to set it up - but there is an instruction (English only) attached.

Hardware
Pretty good - except the glass. I have broken mine quite easily.
Back plate is "stainless steel" according to the label. Once removed - it is very difficult to mount it back.
There are 4 buttons. One to turn on night light and turn on Bluetooth. One to show statistics (steps, etc.). Other are too complex to use.
The watch feels pretty large and heavy. I had larger and heavier watches... but this one just doesn't feel well on the hand.
Strap is some kind of rubber. It has two loops to keep the strap close - a good thing.
Inside there is a sticker saying that quality check has passed.
Bluetooth is 4.0 low energy. It is loosing connectivity often so you need to turn on the Bluetooth once in a while to connect it back. Bluetooth is loosing connectivity once disconnected for a while (it is good as it won't drain the battery but bad also as you won't re-connect automatically).
Button 1 (top left) will enable dimmed light and will enable/disable Bluetooth when pressed for some longer time.
Manufacturer promised 6 months of usage when Bluetooth is on. And waterproof case up to 50 meters of depth.

Software
Weakest part of the watch. Poor translation, not much functionality. And it looses all the statistics after watch restart.
It has nice backgrounds - if you like looking at pictures then it is nice. But if you prefer functionality over the look..... well... buy another one.
Application drains battery a bit. But only a bit.
After connected - it will set up the clock and date. Very nice thing.

Firmware
All the icons are "on" by default. If you expect to be informed about important events such as incoming SMS or a call... it is a bad choice.
You won't be able to use the watch for anything else than pre-defined features as the software is closed source and the communication protocols are "custom".

Summary
I liked the watch (until the glass broke). For the price ($15) I would expect a bit more - but the price is not that bad either.
I would imagine that the watch could be really nice if they would:
- release the firmware source
- release API documentation for the communication protocol
- improve the case back plate and glass

Android being overwhelming for me....

Today I tried to create a simple application for android. And I failed.

First a short introduction.
To create android applications you usually download a free copy of Android Studio. This is a free IDE (application that you code with) which is in fact an editor made by JetBrains and adjusted for google, then released for free.

To have the phone responsive, applications are separated into several layers.
User interface - is the part you play with by touching, clicking, dragging, etc. It does nothing on its own.
Resources - this is nowadays majority of the app.
Code itself.... should be easy to develop but I failed on that one. Let's call this a backend - although there is more than that.

What I expected:
I expected an easy way to bind objects on the interface and backend and to write logic behind that.

What I found:
Un-intuitive interface that requires me to jump through many layers of complex logic in order to create an app. Unknown terms such as activities (and main activity), fragments, panels, objects, many restrictions on those (enforced to keep the UI simple).

I wanted to create a simple app that has:
- A list. With items. Editable.
- A menu. To add dummy items.
The list is possible to add - but rendering, data management and all the other things are more complex. Menu gets inflated, items are difficult to get. I wanted to disable an UI item but failed to even get the item.
I wanted some hierarchical view on the list. But list is meant to kept simple and restricted to that.
And objects such as menus are fixed. And made as resources. Any extra objects are made up with some complex code.

I rarely do that but this time I will switch back to HTML 5 leaving android development behind. It is developing too quickly and getting too-over-complex-and-complicated-and-obfuscated-and-incompatible-with-every-version. Just another Internet Explorer where version 5.0 was not compatible with 5.5 (not mentioning newer ones).

Windows activation and being legal...

I love Linux. Free OS. And I hate Windows OS. Why? Some good arguments bellow.

I have over a dozen of original XP installation disks. Just imagine how much it costed.
There is no source available for Windows. Some people say that having "closed source" improves security - but it is like saying that precious crunchy porcelain covered with a blanket is more safe than without... It just hides the things from you and gives false feeling of being safe.
Recently Microsoft killed XP updates. Meaning that your computer has no more security updates and is now likely very vulnerable. And there is nothing you can do about it - as there is no source.
Windows can ask for re-activation from time to time (ex. When you upgrade some hardware). And you MUST reactivate to use it.
Microsoft shut down activation server for XP so you can no longer (re)activate your expensive genuine windows.
According to the licence you are not buying any operating system. You just pay a lot of money for the right to have it running on your computer (unless Microsoft says differently). Optionally with a compact disk. Optionally with ads.
Microsoft can change the license any time.
Again - you pay for something you don't own.
Microsoft can install anything on your computer at any time. Or uninstall. Or track you and send your data and passwords to anyone including US government, but other parties as well.
Some software might be running on windows. And only on windows as microsoft doesn't wish you to use other OS.
You might be forced by some parties to use windows.
On XBox if you have kinect... microsoft reserved itself rights to take naked pictures of you and share it over the internet. And more. Really. Have you read the license? I did.