2 hours ago, mcstroom said:

I'am doing a Btec applied science course and this just the first assigmnt on organic chem  its unit 14 A 

 

Quote

BTEC APPLIED SCIENCE: UNIT 14 - Learning Aim A

Stuvia

https://www.stuvia.com › en-gb › doc › btec-applied-s...

 

 

 

21 Mar 2022 — Understand the structures, reactions and properties of functional group compounds

Please note what it says on the website.

https://www.google.co.uk/search?q=Btech+applied+science+unit+14A&sca_esv=594049696&source=hp&ei=eGqMZcbKCLnWhbIPrra4gAo&iflsig=AO6bgOgAAAAAZYx4iBjvsOtDmoB1KoM0zZkkk8SVAYP3&ved=0ahUKEwjG5t6cnbCDAxU5a0EAHS4bDqAQ4dUDCAw&uact=5&oq=Btech+applied+science+unit+14A&gs_lp=Egdnd3Mtd2l6Ih5CdGVjaCBhcHBsaWVkIHNjaWVuY2UgdW5pdCAxNEEyBxAhGKABGAoyBxAhGKABGApI10NQAFj6QHAAeACQAQCYAbYBoAGcGKoBBTE1LjE1uAEDyAEA-AEBwgIREC4YgAQYsQMYgwEYxwEY0QPCAhEQLhiABBiKBRixAxiDARjUAsICCxAAGIAEGLEDGIMBwgIOEC4YgAQYsQMYxwEY0QPCAggQABiABBixA8ICDRAAGIAEGLEDGIMBGArCAgoQABiABBixAxgKwgIFEAAYgATCAgsQLhiABBjHARivAcICBxAAGIAEGArCAg4QLhiABBjHARivARiOBcICBxAuGIAEGArCAgcQABiABBgNwgIIEAAYFhgeGArCAgYQABgWGB7CAgsQABiABBiKBRiGAw&sclient=gws-wiz#ip=1

 

This stuff is University level, definitely above A level, it was not even on my S level all those years ago.

 

So you have have quite a few prerequisites in Chemistry before attempting it.

As exchemist said you don't solve chemical equations they are nothing like mathematical ones.
And they don't have terms they have species  - reagents and products.

In fact they are more like a recipe in cookery.

Eggs + flour + water = egg noodles

Eggs + flour + water = bread

 

Should should we really be starting by finding out what the question you were asked really said, because it said nothing about solving ?

 

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For each of the following reactions name the organic product and write an equation.

 

Quote

I'am solving equations that have the following terms in their equation. What should I do

Show us that you have done some work on this before seeking help.

 

Do you understand what the substances are, can you write formulae for any of them ?

40 minutes ago, Spring Theory said:

What I'm proposing is that there must be some charge source for an electric field within the photon. The definition of an electric field is the physical field that surrounds electrically charged particles. You can't have one without the other. My model will deterministically describe charge as momentum.

I don't agree.

 

So an electric field is generayed by a charged particle, say an electron.

But once the field has left the electron what destroys it, or why can't it exist without the electron ?

 

What in Maxwell's or other equations prevents this ?

On 12/24/2023 at 5:52 PM, Fermer05 said:

According to the Static Tidal Theory, the Lunar tidal wave moves from east to west following the moon, at a speed of 1600 km / h, skirting the Earth in 24 hours, flooding only the eastern shores of the continents. But after centuries it was discovered.
1. That the Lunar tidal wave floods both the western and southern and northern coasts of the continents?
2. That the speed of a tidal wave of 1600 km / h is detrimental to both continents and marine fauna?
3. That not two tidal humps function simultaneously across the globe, but more than a hundred, regardless of the location of the Moon?
4. That abnormally high tides for some reason are formed in semi-closed bays, where there is no direct access to the tidal wave. And in the bays open to the tidal wave, there are no tides at all, or are they small?

Later, the Dynamic theory of tides was proposed, which was supposed to answer all the questions posed.
According to the dynamic theory of tides, the Lunar tidal wave moves from east to west at a speed of 800 to 1600 km / h.
Crashing into the continents, part of the wave is scattered in place, and the reflected part rotates around the ocean, thanks to the Coriolis effect. Like water that spins in a cup when you slide the cup back and forth.
The only link on the Internet that reveals the "essence" of the dynamic theory of tides. http://ffden-2.phys.uaf.edu/645fall2003_web.dir/Ellie_Boyce/dynamic.htm
 
But the dynamic theory of  tides does not answer all the questions posed.
1. What is the mechanism of tidal wave scattering in the region of collision of the tidal hump with the continent?
2. If the cup of water is moved back and forth, the water will splash out and not rotate.
3. How does the tidal current that travels along the coast create the ebb and flow?

I wonder if there is a language difficulty because you seem to be asking questions (which is good) rather than trying to preach.

But I would say that you are posting too much at once.

 

So I am going to start with the first part of your post and begin to answer these questions.

Then we can see how we go.

So the Moon orbits the Earthonce every 27.3 days which makes it angular speed of 2π / (27.3 x24)  radians per hour.

This is approximately 0.01 rads/hr.. (It will become clear why I am using these units)

 

The Earth also rotates at an angular speed of 2π/24  radians per hour

Which is approximately 0.26 rads/hr.

Since both rotations are in the same direction the net rotational difference is their difference or 0.26  -  0.01  = 0.25 rads/hr.

The radius of the Earth is 6731 kilometres.

So if a static bulge is to keep up with the moon is must travel at 6731 x 0.25  km per hour.

This agrees with your calculation.

A wave travelling at this speed is the basis of the simple dynamic theory.

But this theory is only applicable within the following constraints.

If the depth of the water is d in km then waves of wavelength L will propagate witha velocity of v =  √(gL/2π) for waves in deep water.

Where g is the acceleration due to gravity in km/hr² which is 127008 km/hr²

This makes the wavelength as (1600*1600*2π) / 127008

or 127 km.

However this formulae is only valid for d/L greater than 0.5.

Now the average depth of the ocean is around 3.6 km and tha max depth is only 11 km (NOAA)

So dl << 0.5 and the condition is not satisfied for the deep water formulae.

 

Which makes the ocean too shallow for a simple resonant system.

 

So instead we must use the shallow water which then includes the effect of the bottom and other topography.

The formula for such waves is given by

v = √(gd)

Which is good to around

(1600 * 1600) /127008 km

Which is approximately 20km.

 

This emans that the wave equation is no longer homogenous (equal to zero in this case)

There is now a forcing term involved as well and the theory is known as forcing.

 

 

Does this help and do you wish to continue ?

 

1 hour ago, mar_mar said:

Thank you. So, what is the nature of this property? I believe, speed is also property of an object, it describes how fast it moves. Mass describes how much matter in an object, in short.

What does describe energy as a property?

 

41 minutes ago, mar_mar said:

I try to find in the nature of property of energy ability to do work.

If you are prepared to listen to the explanation and to follow it as it is developed bit by bit then I am happy to discuss your request with you.

The above are very reasonable wish to explore in more detail the short statements you have already been offered.

 

So we should start with 2 matters.

Firstly the issue of 'work'.

Do you know what 'work' is. Without a good understanding of this you will not understand the answer.

 

Secondly I said there are several ways something can have energy so we should start with the simplest, which is also the easiest to relate to 'work'.

The simplest type of energy is called Potential Energy and is the energy of configuration.

For a simple system, for example when there are only two objects involved, the 'configuration' may be as simple as the distance between them.

When that configuration changes the distance between them changes and the potential energy changes.

That potential energy is equal to the work done in the change and how we get the statement

Energy is the capacity to do work.

 

 

There is only one sort of energy.

Material objects and fields may posses energy by a variety of different mechanisms.

All of energy theory springs from these two facts.

Much of that theory is about transferring the energy from one body or field to another; the energy transferred may end up in a different form (ie using a different mechanism).

Most of the terminology refers to these mechanisms by which the body or field possess or transfers the energy. Solar energy, electrical energy, nuclear energy etc etc.

So when you use such terminology you need to specify not only the energy but also the mechanisms involved.

It is quite difficult to compose a good opening post, to strike the right balance between not including enough information and including too much, whilst yet ensuring that all the significan stuff is there.

 

So is this a casual amateur enquiry, perhaps only a one off,  or is it by way of trade of large scale use over a long term period ?

Silicone lubricant comes in various formats. Various consistencies of tubs, tubes,  and sprays.

Any manufacturer wanting specific use certification has to pay a significant cost to obtain that certification.
So they will weigh up those costs agains likely sales for that use.
They will also probably have a discalimer to the effect that as they do not control the conditions of use or application they can only take responsibility for that certified.

Safety sheets, are meant for the safety of the user applying the substance, not necessarily a person down the line.

My personal issue with grease is that in a plumber's situation there is considerable danger of the grease becoming contaminated with other material, in particular gritty material.
This gritty material may not matter in a thread locking situation, but could destroy the sealing capacity of an O ring.

I know you are having to translate this from the Russian, but you would perhaps be taken  more seriously if you didn't mix up established English terms.

Tidal movements rarely crash into anything.

The 'wave' analysis of tidal phenomena is not about a tidal wave, which is an entirely different phenomenon.

Yes vertical water movements due to tides must be accompanied by horizontal water movements.
But these are termed tidal streams. They are not ocean currents, which have a different origin and coexist with tidal activity.

Actual water movements are always the sum of all influencing factors, wind, topography, river discharge, ocean currents, turbidity curents, occasional earth movements, seasonal distances of the Moon and Sun, to name the principal factors.

Safe, yes but should you be using grease on a sealing O ring ?

A dash of washing up liquid will help it on, and then wash awat leaving no interfering residue.

O rings are designed to seal under the pressure of the liquid or gas.

I presume this is not David Lapoint the baseball player, but David Allen Lapoint the man who has an application US Patent for a Controlled Fusion Reactor  !

 

https://www.sumobrain.com/patents/wipo/Controlled-fusion-reactor/WO2023172373A2.html

21 minutes ago, joigus said:

The vocal cords are vibrating when you pronounce "rather" while they're not when you pronounce "with" resulting in two very different sounds. Try it, and you'll see.

So, in answer to your question: Since the moment you pronounce them. Exactly as in "them" and "bath" (different).

I don't care what funny words any linguist uses to describe them. I've done an experiment, and in my book that is sacred.

A better example would be lather (voiced) and lath (unvoiced) and lathe (voiced)

26 minutes ago, Cap'n Refsmmat said:

I just had some fun writing a SQL query of the forum database, and it appears you have a PM conversation from February 2021 titled "C-19", and the system thinks it has unread posts. Why it's notifying you about them now I have no idea, but it's a real conversation.

This link should take you to it:  https://www.scienceforums.net/messenger/70769/

For my future reference, here's the query:

SELECT msg_author_id, msg_topic_id, from_unixtime(msg_date), map_has_unread, msg_post, mt_title 
FROM `core_message_posts` 
LEFT JOIN `core_message_topics` ON msg_topic_id = mt_id 
LEFT JOIN `core_message_topic_user_map` ON mt_id = map_topic_id 
WHERE map_user_id = 74263 
ORDER BY msg_date DESC; 

 

Many Thanks.

 

You have a PM about it.

14 minutes ago, Phi for All said:

We'll get an Admin to look at this activity. 

Thanks, please let me know if I can provide any further useful info.

I am not a linguist but it will certainly be interesting to hear the views of others on this as I support the notion of widening the scope of the English Language.

I am going to answer in note form so that my post will not be as long as yours. So if details are missing please ask for more.

 

1) English is not, and never has made any pretence to be phonetic.  There are several obstacles to phoneticising.

2) Unlike French and Chinese there is no controlling body for the language.  Interestingly English was made the official language of China in the 1950s.

3) When we talk seriously about English we should specify which English ?

 

I agree that @joigus' example is incorrect however how would you describe the following statement

The bath ?

The first th is pronounced differently from the second and the letter a is pronounced differently depending upon your dialect.

If you are going to extend the english alphabet I would suggest that the letter a is a more worthy candidate the the digraph 'th'.

The starange message appeared again just now as I logged in tonight.

 

I really would appreciate a reply from a moderator or administrator as to whethere thi notice could be generated by the site software.

2 hours ago, TheVat said:

The study of alignments of random points in a plane seeks to discover subsets of points that occupy an approximately straight line within a larger set of points that are randomly placed in a planar region. Studies have shown that such near-alignments occur by chance with greater frequency than one might intuitively expect....

https://en.wikipedia.org/wiki/Alignments_of_random_points

 

 

+1

Or you can do my sheet of paper an peperpot (ink sander) experiment.

 

Another variation to play with is Buffons needle.

https://en.wikipedia.org/wiki/Buffon's_needle_problem

I'm sure we've had this thread, been there got the teashirt before.

4 hours ago, pzkpfw said:

Is there a way to uniquely pair elements from A and B 1-to-1 ?

I'm sure you actually meant something else.

 

On 9/14/2023 at 11:56 PM, GrahamF said:

Stuff like pictures of a chip under a microscope and such, stuff that shows the physical damage. I know that general consensus is that electronics will be destroyed by an AMP, but I'd like to look up at what point or conditions would a device just need to be rebooted or if it will be unaffected. I'm wondering if work over the years to protect electronics from electrostatic shock would add some form of resistance to them?

 

17 minutes ago, swansont said:

You should be aware that a voltage spike is one manifestation of an EMP. Any electronics damaged by not having a surge protector could be an example. Protection from EMP can range from disturbances at a few hertz out to a GHz, through the air or through the wiring.

 

Campfire electric generators and EMP questions.

 

Are you a survivalist preparing for a nuclear war ?

 

I remember discussion after TSR2 was cancelled, because it was thought that the russian military electronic hardware was still way behind the West and all driven on valve technology, as was that of TSR2.

Because of this it was thought that they would survive an EMP much more than the West which was going wholesale semiconductor.

 

Swansont's point about voltage spike is the relevant parameter because semiconductors have quite low thresholds of overvoltage.
I have seen significant damage cause to semiconductor equipment by lightning strikes, which produce more localised EMPs.
There is no protection from this because it is atmouspherically borne.

Also protection devices are nearly all 'one-shot', which means that they are sacrificially damaged/destroyed in preference to the protected equipment and should be replaced after every active operation.

So one EMP or many ?

3 hours ago, GrahamF said:

Would it be possible to make a very compact and lightweight steam engine powering an electric generator that can be taken back country camping and used to keep lights and other devices charged the entire time just by looping it into the campfire? And could it be expanded to being hooked into the wood stove of a cabin to keep the lights and other devices running as long as there is a fire in the stove? How cheaply could such a generator be made while still producing an acceptable amount of power, such as charging a smartphone at full speed in the small camping version and possibly running a full cabin's lighting and a computer and Starlink internet connection in a larger version?

Very interesting proposition and well worth discussing.  +1

Compact  ?  

Efficient  ?

Simple  ?

You missed one  -  Safe ?

 

I don't think steam is the way to go but it is certainly possible.

 

Let us say that your power requirements are up to a couple of hundred watts and work with that.

This is available from Hero's steam engine in Ancient Greece a couple of thousand years ago.
Modern estimates, base on available model engineering place the efficiency as between less than 0.1% and up to 1%.

But there are many practical and safety drawbacks to steam since you loose the working fluid by expansion and have to keep topping up the water supply.

Speed regulation would also be required as the output would otherwise vary over a very wide range, as the device spin speed is heavily temperature dependant and a camp fire is not a steady temperature.
From a safety point of view, the exhaust steam would need safe dissipation.
Topping up the water is not only  a chore, but also a safety matter since any boiler could explode with too little water.

So  a closed system should be devised.

 

By using hot water rather than steam this could be achieved.

Any electric moter can be run as a generator so thinking about central heating pumps, with come in a 20 to 200 watt range their technology could be employed.
Such pumps are available with an impellor rotor sealed in a chamber and driven magnetically by the mains supply.
Reversing the idea could produce wattage in the desired range,
So a sealed chamber heater with some tubing could provide a ciculating system which drives a gravity hot water flow, safely and more controllably than with steam.

 

However other modern technology, as described by exchemist (+1) also fall within this wattage range.

Quote

https://www.intechopen.com/chapters/65239

A single TEG generates power from 1 to 125 W. The use of more TEGs in a modular connection may increase the power up to 5 kW and Δ T _max could be bigger than 70°C. Heat source , for example, a heat pipe system (the TEG devices and the heat pipe system can be used together in waste heat recovery systems).

In this case the device would be indirectly heated by the campfire to keep within its operating temperature range.

 

So these are practical points for thought and discussion.

Quote

Wikipedia

Today Old Norse has developed into the modern North Germanic languages Icelandic, Faroese, Norwegian, Danish, Swedish, and other North Germanic varieties of which Norwegian, Danish and Swedish retain considerable mutual intelligibility while Icelandic remains the closest to Old Norse.

 

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Quora

The Old Norse language, spoken by the Norse people, was a North Germanic language, while Old English, spoken by the Anglo-Saxons, was a West Germanic language. Although there were some similarities due to their shared Germanic roots, the languages had distinct grammar, vocabulary, and pronunciation.

 

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Scholar Commons

Could Old English and Old Norse understand each other?

 

 

In the past, it was the general agreement of historians that there existed little or no amount of mutual intelligibility between the English and Norse peoples of this time.

 

English is descended from AngloSaxon not Old Norse.

Out of interest I borrowed my wifes's copy of Sweet's AnglosSaxon Reader, 5th Ed,  1895.

When she was at Londondon university all students of English were required to be competent in Old English.

The interesting thing is that I could not find your letters in Sweet, although there is some similarity.

 

 

Modern English please, because it may be that you have something interesting and worthwhile to discuss.

 

Ed I have just corrected my spelling mistakes.
I think that is more than enough to lay onto other members, without adding alphabetic ones as well.

18 hours ago, phyti said:

'Infinity' is not a number, It's a state/property of not having a boundary, thus can't be measured (counted). There are no degrees of infinite. A thing has a boundary or it doesn't.

 

1 hour ago, KJW said:

Although I agree about infinity being unbounded, are you sure that is the only property of infinity?

 

An Infinity can be bounded below or bounded above yet unbounded in the other.

2 hours ago, Luc Turpin said:

Will gladly go back to school and will be reviewing our discussion about linear mathematics.

Please do because that thread introduced several utterly fundamental ideas in Mathematics, some of them so simple that people tend to pass over them too quickly.

 

In the mathematical world we have abstract idealisations.

These are often models of the material world.

We can pretend that the material world follows our mathematical model for some limited extent of the mathematical model.

(just like with the linear model of the curve)

So in that thread I introduced 'the world of shapes'

These are idealisations or perfect implementations of a mathematical idea for instance of a square.

The material world cannot match squares (or any other shape) perfectly at all scales.

If we make the square small enough the gaps between the atoms stop the square being complete.

But we can get pretty good squares from a block of concrete.

So nothing in the material world is truly scale invariant. It is a good match just for a range of scales.

 

So we come to self similarity.

Two figures  in mathematics are called 'similar' if their shape are the same, except for a scale factor.

For instance a triangle with angles 45, 45, 90 is similar to any other and all other triangles with these three angles.

But when we look at squares there is a difficulty.

For a square, not only do all the angles have to be 90, but all the sides have to be the same length for a figure to be a square !

We have just introduced a second parameter  -- Length, which was not needed for the triangle.

 

There is a no problem if we scale the side lengths by the same factor. So a square with all sides twice as long as another square is similar to the other square.

But now the area of the figure is scaled by a different factor as the larger square has four times the area of the smaller.

 

But since the two squares are still similar we observe that the similarity property can involve more than one scale factor being applied appropriately.

So when we talk about self similarity between two shapes we need to specify what property is being scaled and therefore self similar.

 

It gets yet more complicated as we could apply different scales along two or more of the coordinate axes.

This will change the spae of the similarity so it is not called a similarity but an affinity.

 

Fractals can also be made from self affinities.

Fractals that have nothing to do with shape in the material world can also be made by

Self organisation, though not all such organisation leads to fractal geometry.

Self replication

probabilistic trees,  though not all such trees are fractal.

 

Fractals are so named because their apparent 'dimension' is not a whole number.

Our material world is firmly 3 dimensional plus time so nothing material can actually be fractal.

So when we say that a coastline length is fractal, we are saying that there is a fractal abstract model which is self similar down to infinitesimal sizes that matches the given coastline to some finite limiting size.
Coastlines are interesting because this limiting size of self similar is actually very large.

Yes there are smaller and smaller bays and inlets and peninsulas, but the smaller ones are not an exact shape copy of the larger ones.

This is the difference between a material world fractal and a mathematical world one like the Koch snowflake, where every reduction of scale brings an exact copy of shape.

Merry Christmas to all members.

 

39 minutes ago, Genady said:

Curvature is encoded in second derivatives of metric. So, any tensor that depends on second derivatives of metric, describes curvature in some way. Einstein tensor describes curvature in a way that can be related to the spacetime's physical contents.

+1