Why is a retracting mast preferable to a freestanding rig with, e.g. a roller furling main or a nonsuch style wishbone boom? Is there a physics reason or is this a pragmatic trade-off to fit under bridges and stay out of the way during loading?
Animals in general are only a tiny sliver of life on this planet. What most people think of as 'nature' i.e. large animals that a child can name are vastly outweighed each by worms, molluscs, bacteria, insects, and of course -- by a couple orders of magnitude -- plants.
>The report projected that the United States would have a cumulative total of 7.5 to 10 million metric tons of solar panel waste in 2050.
This compares to 292 million tons of total landfill waste in 2018 alone [1], putting solar panel waste on the order of 0.1% of total waste produced in the US between now and 2050.
I've been on the other side as a buyer. Although I work with 'main street' companies, not high tech, I think there's a lot of generalizable lessons. One thing to keep in mind is that some buyers have substantially all of their eggs in your basket and others will constantly have multiple deals in the pipeline. When you enter into the LOI phase with someone, you want them to be very motivated to close in order to make the time / disclosure / trade secrets risk worth it, so I would encourage sellers to attempt to enter LOI only with motivated buyers that have a high likelihood of closing the deal. A few hallmarks of motivated buyers per my experience:
- The buyer will also be the CEO: the more the buyer looks like he/she will package your business up and pass it along, the lower the likelihood that they close (and the worse your earn out is likely to perform)
- Good buyer / company fit: similar to point one, do not let people tell you they can run this company. Grill them just like you would if you were hiring a CEO to replace yourself. Buyer / company fit is huge and when they say 'the owner is too important to the company' what they often mean is 'I don't think I can run this well'. Someone who knows and is building a portfolio in your space will often be a better buyer than someone looking for 'diversification'.
- Avoid tire kickers: Background in your space is good, but being a competitor to you is bad. If they could potentially gain valuable insider information as part of diligence, be wary of moving forward.
- Small team size: smaller firms have less in the pipeline and more motivation to close on the deal in front of them. Remember that they have the same KPI (IRR primarily) and runway problems that startups have. For them, no company = no ROI.
- Ensure they're well funded: The caveat to the above is that small teams or solo buyers may not have the funds lined up, so be very sure that they actually have the investors / NW to buy the business before moving forward.
Plenty of electric scooters have no mechanical brakes and only electric braking on one hub. But since an extra couple feet of stopping power can be a life or death feature, you definitely want breaking on both tires. Even assuming no reliability issues with the electric breaks (hello sudden rain storm), mechanical is a cheap and weight efficient way of adding braking to the second hub.
Virtually everything besides Rolex, Patek, AP and Vacheron is in stock. For anyone on the wait-list or considering going grey market for a high demand model, I'd strongly recommend looking at comparable models from the wide variety of competing manufacturers. Not only will you get a lot more watch for your time and/or money, you'll support the breadth of artistry that makes the industry so vibrant.
One issue with solar is where we put it all. If it turns out that a meaningful portion of farmland has an excess of solar energy, that takes a big bite out of the problem. Powering the US entirely on solar might take a land mass equivalent to 2% of the country... Only a small portion of the 40% of US land area used as farmland.
I was confused at first by a lot of diagrams I found online, but the wiki is pretty good. Basically think of a two way radiator. Hot air flows through air channel blades on the way out, cold air flows around the blades on the way in, with filtering optional at this point. Some systems indicate that they literally mix the air, which is obviously not going to be optimal, the air needs to be fully separated with the energy exchanging through a metal layer.
I'm in SF. The tricky thing here is that outdoor humidity is often so high that a humidistat would only result in an 'always on' system. I think CO2 is an objectively better measure anyway. You can remove humidity and particulate with energy efficient machines. You can't (realistically) do that with CO2 / VOCs.
I think an ideal heat recovery system would probably sit mid-stream in a central air system with a built in CO2 trigger. Basically, the return air gets exhausted while heating the incoming/supply air when CO2 concentration > X. Obviously you run into the capex vs ongoing energy cost tradeoff in designing the system.
Strangely, I couldn't find a ventilator on market with a CO2 sensor, but there are plenty with humidity sensors. I think CO2 sensors are on the horizon though, here's a study featuring such a system: https://core.ac.uk/download/pdf/43245317.pdf
My current system is actually ductless however, so I will probably have to rely on natural diffusion... I do have an air quality monitor which indicates that diffusion is likely sufficient (for a one floor open plan condo), but you'll optimally need to sleep with the bedroom doors open.
Edit: I haven't looked too deeply at the standards. My little sensor indicates that if you keep CO2 in range, VOCs will also also be in range, which conforms with my intuition.
I recently retrofit a new HVAC system and as a result have also gone on a bit of a deep dive on indoor air quality. The big thing I learned is that most homes -- even old "leaky" builds -- have rather poor ventilation, meaning all sorts of compounds build up in the air... CO2, formaldehyde, VOCs, PFAS, etc. Air purifiers work for particulate, but don't really make a dent for chemicals. IIRC, You would need like a 50 gallon drum of activated carbon to do anything on the chemical front.
A quick solution is to crack the windows, or if you live in a non-temperate climate, install an energy recovery ventilating system.
Truly massive and sorrowful results if it holds up to review / replication. From the preprint:
>Across all measures, we found cognitive scores were significantly reduced during the pandemic by 27 to 37 points (or almost two full standard deviations), p values < 0.01
Standard advice in the nutrition community is to that most people should be substituting processed foods and meats in the diet with whole fruits, whole vegetables and whole grains (a "plant based" diet):
Healthy diets strongly correlate with both sufficient fiber and healthy BMIs. The point is that 95% of people don't have healthy diets. As long as diets remain so poor -- the phrase "standard American diet" purposely forms the acronym SAD -- there is no obesity mystery.
Thirteen thousand words and no discussion of the elephant in the room: 95% of Americans don't eat enough fiber. Fiber is the bulk that keeps you full between meals and that bulk -- quite literally -- helps prevent overeating. If 19/20 people aren't even getting their macronutrient balance right, perhaps we should start there.
Spring drive's are cool. I'll try my best fast explanation: it has an ordinary rotor and spring barrel, but replaces the escapement with a flywheel, an electromagnetic break (like you have on an ebike) and a quartz controller. The rotor winds the spring barrel, the spring barrel powers the flywheel, and the break generates electricity for the controller, which keeps track of the time and then in turn tells the break how fast to allow the flywheel to spin.
The fact that they sidestep the need for a battery (the spring barrel pretty much is the battery) is the clever part here. It's more efficient than using a rotor to charge a battery and run a stepper motor, and more accurate than a purely mechanical escapement. But it's still fundamentally a quartz watch, which turns some purists off.