SteamyTea

I think some 'unwind' the cable every now and again. Small ones often have a stop, so can only rotate 359⁰.

https://www.hedgesdirect.co.uk/acatalog/Pyracantha-hedge-plants.html Keeps out just about everything.

Did they charge you for that? I see they charge 3p/minute for telephone calls, even if placing an order.

This has been an ongoing debate in education. Some educationalists think that courses should be developed to a more specialised areas i.e. Forensic Science, Renewable Energy, while others think a more general education is better i.e. mathematics, Physics. This gets much harder with the arts and humanities i.e. painting or sculpting, early learning or phycology. As part of my post grad in education, I had to observe a lesson in the art department, it was in textiles. I pointed out that it was really engineering and technology, but the 4 students thought it as art and craft (incidentally I had 30 IT students when I was observed, and only 26 working PCs, that is a challenge, peer learning comes to ones rescue in that situation). My view is that with the sciences the first year should be the basics, second year students split off into interest groups i.e. chemistry, software, botany. Then the final year should be projects. Take my first degree, we had I think, 6 or 7 subjects (we turned down vehicle electronics, but it was over 40 years ago), second degree I think it was 18 subjects in all, including my favourite, environmental economics (I can put a price on nature, it is easy with proper surveys), and philosophy (which at the time I thought was nonsense, but looking back, was useful, should have been in the first year). Everyone should be taught Thermodynamics, Laws of Motion, the SI units, Laws of Indices and Algebra, along with English (or whatever language in your country). International Sign Language would be useful at primary school for a few years, it is the closest we have to a universal language (I am a BSL user, though out of practice now). There should be a 'how to deal with OFSTEAD inspectors' as part of the PGCE, it is all that college managers seem to care about. I have seen really good lecturers go to pieces and leave because of an over promoted, useless colleague, has been put in charge of internal inspections and totally missed the point of education.

Around 61 MPH gallon then. Sea is only a couple of miles from me. Tell that to the emmets in St. Ives.

Or go digital, for 11 quid. https://www.ebay.co.uk/itm/184762902220 Drive up hills at a constant speed, accelerating against gravity cost way too much.

Just goes to show that I did not totally waste my time studying automotive engineering.

Unless you can dig the floor up and add about 150mm of insulation, forget UFH. The temperature differences are to great. All you will be doing is warming up worms.

@joe90 knows a fair bit about warm roofs. Hopefully he will be along.

Along with the insulation (warm roof helps all over) have you considered integrated PV? It can help reduce temperatures in the summer as the energy is converted to electricity and does something useful.

I think Cornwall's CIL goes to pay for the pension deficit of £300m (ish). £400/m2 in Zone One down here. Wish I could charge builders to pay the deficit in my pension, with the threat that if they fail to pay I have their homes.

Welcome Non negotiables should be insulation and airtightness. This helps all the time. From my point of view kitchens, bathrooms and lighting are where money can easily be lost for little benefit.

Glad to hear it. What does that mean (as simple as you like) Diesels are lean burn engines. The power output is varied by making the mixture of air and fuel either fuel heavy (more power) or fuel light (less power). Petrol engines have the same air/fuel ratio across the whole power band (stoichiometric). You may have noticed that when some diesels pull away, or accelerate heavily, they smoke. This is unburnt (wasted) fuel. No extra power is produced at the smoke limit. There is a fine balance, for all combustion, on the air/fuel ratio to get maximum power at any given moment. This has got more complicated with the introduction of turbo charging. This has the same effect of putting in a larger normally aspetated engine i.e. you get more fuel to burn in more air. Turboing has the advantage that it is also scavenging energy that is usually wasted from the exhaust, and you can have a better bore and stroke ratio i.e. reducing the total surface area to reduce heat losses. The compression ratio has two functions. The higher it is, the more air is heated up, this aids combustion in a diesel. But go too far and you get pre ignition. This is when the compressed air is hot enough to ignite the fuel, before the piston has reached the top (TDC). Fuel in both types of engines is actually present before TDC, this is to allow for a few milliseconds that it takes for combustion to start. To get around this pre ignition problem, fuels have ignition retardants added, octane and cetane are the rating numbers for gasoline and diesel respectively. Low numbers burn faster. This is why old American cars had large engines, their fuel was at a lower octane rating (this does not mean lower energy density or quality), so lower compression and lower power. But also lower emissions of CO2 and NOX. It is the higher compression ratio of diesels that has caused the NOX problem that VW cheated on. By reducing turbo boost, and running the engine cooler while being tested, less NOX is produced, there is less power, but they does not show up during a static tests. Ideally an engines power is measured as Specific Brake Power. All this means is how much power comes out for the amount of fuel put in. It leads to some interesting numbers for large engines, which are generally more thermally efficient at part load. Tried now and it is getting dark, time to head home from the very end, almost, of the country.

A very good question. An ICE is a spark ignition engine. Fuel/air goes in, gets compressed, and at the right time, ignited by the spark. Now the fun starts. The temperature rises extremely fast, closely followed by the pressure, THEN the piston starts to move. There is a slight bit of combustion happening as the piston moves down the bore (flame front and all that, why Wankles are hopeless on fuel economy), but basically the temperature and pressure rises at the very start of the stroke, then rapidly decreases. Diesels on the other hand, limit the initial amount of fuel that is injected, this is ignited purely by the temperature of the compressed air. As the piston moved down the stroke, more fuel is injected, keeping the flame front alive, this keeps the temperature and pressure high for a greater amount of time. It also means that when the crank is 30° either side of 90° from TDC, on the ignition cycle, combustion is still happening, this is the crank position that allows most dynamic torque to be produced. Diesels are often referred to as 3 stage combustion. There are also differences in air delivery pressure and temperature, bore/stroke ratio, gearing etc. Gasoline engine Diesel Engine

Well known that the C connector is a quantum device. Try and plug it in, it will not fit, turn 180°, still does not fit, turn 180° again, still does not fit, again, no, finally after 720° of turn, it fits. Well known and understood quantum spin characteristic.

Is this what you are after?

Kinetic energy at the molecular level. Confused by liquid water's surface tension, and capillary action. Add to that the dynamics of temperature, pressure, humidity differentials, latent and sensible heat, and then some uncertainty, it is a miracle that all roofs keep the water out and stay up. Thankfully we have solutions to partial differential equations to help, but I prefer to call them partial solutions to equations. You get marks for showing your workings.

I think it is confused by practicalities as you mention here. Really just forces and motion once you reduce the units to their most basic.

As it is a cold roof, ventilation should be there. Or convert it to a warm roof. A lot depends on how it is used i.e. permanently heated, or spasmodically heated. That will change where the VCL goes, but down here, on the inside is probably best.

It is easy. Force at a Distance, hence Nm. Remember that acceleration is a change in speed or direction. Another way to look at is is as a change in power. Taking an automotive analogy, for any given amount of power, on a dead level road, with constant weather conditions, you may find that when the motor delivers 20 kW, the car will do say 40 km/h, at 30 kW, 50 km/h and at 40 kW, 55 km/h. Torque is the motors ability to accelerate the car. The reason it can seem confusing is because we tend to use RPM, when we really need to use Radians/second as that is a natural ratio. https://www.engineeringtoolbox.com/work-torque-d_1377.html Or just use the below fudge, it is good enough. Torque (N.m) = 9.5488 x Power (kW) / Speed (RPM) Power (kW) = Torque (N.m) x Speed (RPM) / 9.5488

Get 75 years of advice in 45 minutes https://www.bbc.co.uk/programmes/m001638f

That was lucky. Wave machines have proved to be failures so far, but it was seeing Dr Salter's Ducks, back in 83, that got me interested in the whole RE field.

https://en.wikipedia.org/wiki/Enthalpy_of_vaporization Says 2257 J/g. So yes, think I did get it wrong. So ten times less as you said.

Am and Hegg then. I read in spoonerism monthly that I am this year's shining wit.

Just having Horlicks for mine, after a hot shower, just hope I don't have horrible dreams, but will wake up at home, so no harm done.