What is the solar photovoltaic power generation system?

Système D’électricité solaire is usually divided into grid connected power generation and off grid power generation. Grid connected power generation is to convert the received solar radiation energy into high-voltage DC through photovoltaic modules, output AC after inverter and incorporated into the national power grid; Off grid power generation is for self-use, local consumption and flexible application.
Photovoltaic power generation system is usually divided into grid connected power generation and off grid power generation. Grid-connected power generation is to convert the received solar radiation energy into high-voltage DC through photovoltaic modules, output AC after inverter and incorporated into the national power grid; Off grid power generation is for self use, local consumption and flexible application.
In fact, in real life, because the off grid photovoltaic power generation system is not limited by region and has a wide range of applications, it can be installed and used as long as there is sunlight. Therefore, it is very common, such as lampe de rue solaire, traffic signal lights, agricultural pest control lights, etc., especially suitable for some remote areas without power grid, isolated islands, fishing boats, outdoor breeding bases, etc, It can also be used as emergency power generation equipment in areas with frequent power outages.

There are many ways to produce carbon dioxide in the atmosphere, but one of the main ways is to heat it by burning trees or fossil fuels. As one of the devices of lampe de rue solaire aits, solar panels do not emit carbon dioxide. When we replace traditional energy sources, such as wood or fossil fuels with solar panels, the amount of carbon dioxide we introduce into the atmosphere will be reduced.
The preliminary procurement and installation cost of typical household solar panels is currently equivalent to the cost of traditional energy appliances, such as radiators, water heaters, and so on. But the latest advances in solar panel technology not only make their products cheaper but also increase their kilowatt output efficiency. This means that even if the initial early investment cost may be higher than that of solar panels, the long-term return on investment in energy conservation will be more obvious and effective than ever before. If you want to take yourself from soaring oil and gas costs, now is likely to be the perfect time for solar technology to take a new look in your city and country.
In general, the solar panels of solar street lamps have fewer moving parts than traditional energy-saving appliances, so there are few problems. Usually, once a year, you will do an inspection, but in most cases, suppose you buy quality plates. Once the solar panels are in place, you don’t do much to maintain them. It is estimated that the range is less than 20 hours a year.

The price of solar street lamps is relatively low, energy saving and environmental protection, and the installation procedures are simpler than the traditional ones. At the same time, there is no need to lay very complex circuits. The composition of solar price mainly includes four parts: Lampe de Route LED, street lamp pole, batterie panel and solar street lamp controller.

Neuman boundary conditions for system of PDE in 2D

The system of equations for three variables: n(x,y,t), b(x,y,t) and a(x,y,t) System

The rest of letters are coefficients. System is defined over a square region with the lower left corner at the origin.

Boundary conditions: Boundary

Bold n is the normal vector to the boundary (Neuman condition).

And initial conditions: Initial

My code for solution is the following

(*region*) \[CapitalOmega] = Rectangle[{0, 0}, {1, 1}];  (*constants*) \[Mu]n = 0.001; \[Mu]b = 0.001; \[Chi] = 0.1; bHat = 1.5; \[Lambda]0 = 100; \[Lambda]1 = 100; \[Lambda]2 = 10; \[Lambda]4 = 100; \[Lambda]5 = 10; nHat = 1; \[Lambda]7 = 10; \[Delta] = 0.01; \[Alpha] = 2.5;  aNeuman =    NeumannValue[\[Lambda]7*bHat*a[t, x, y], {x, y} \[Element]RegionBoundary[\[CapitalOmega]]];  (*equations*) eq = {-D[n[t, x, y], t] + \[Mu]n*Laplacian[n[t, x, y], {x, y}] - \[Chi] *       Div[n[t, x, y]*Grad[a[t, x, y], {x, y}], {x, y}] + \[Lambda]1*       a[t, x, y]*b[t, x, y] - \[Lambda]2*n[t, x, y] - \[Lambda]0*(n[t, x, y])^2 == 0,       -D[a[t, x, y], t] + Laplacian[a[t, x, y], {x, y}] +        \[Lambda]4 /2*(1 + Tanh[(1 - b[t, x, y])/\[Delta]]) - (\[Lambda]4 + b[t, x, y])*a[t, x, y] == aNeuman,        -D[b[t, x, y], t] + \[Mu]b*Div[n[t, x, y]*Grad[b[t, x, y], {x, y}], {x, y}] -       Norm[\[Mu]n*Grad[n[t, x, y], {x, y}] - \[Chi] *n[t, x, y]*Grad[a[t, x, y], {x, y}]] == 0};  (*initial conditions*) incs = {n[0, x, y] == If[x == 0 || y == 0 || x == 1 || y == 1, nHat, 0],         a[0, x, y] == 0,         b[0, x, y] == If[x == 0 || y == 0 || x == 1 || y == 1, bHat, 0]};  (*boundary conditions*) bcs = {DirichletCondition[n[t, x, y] == nHat*E^(-\[Alpha]*t), True],        DirichletCondition[b[t, x, y] == bHat, True]};  (*solution*) {nfun, afun, bfun} = NDSolveValue[Join[eq, bcs, incs], {n, a, b}, {t, 0, 2}, {x, y} \[Element] \[CapitalOmega]]; 

This code gives the error (apparently because of the wrong way of adding Neumann condition)

LinearSolve::parpiv: Zero pivot was detected during the numerical factorization  or there was a problem in the iterative refinement process.  It is possible that the matrix is ill-conditioned or singular. 

I actually have two questions.

  1. How to properly implement the boundary condition for a(x,y,t)?

  2. When I replace this Neuman condition with the Dirichlet one (which is wrong, but for testing puprposes), the solver starts to work, but then I get another error:

    NDSolveValue::ndsz: At t == 1.8768713852597982`, step size is effectively zero; singularity or stiff system suspected.

This error goes away when I set all coeffitienst of the equations equal to 1. But could you, please, help me with solving the system with original coeffitients?

P.S. My Mathematica version is 12.1

P.P.S. Sorry for that Greek letters. I tried make them consistent with the original equations. If they really distract you, please, tell, I will rename.

how to solve a system of equations with inexact coefficients

I going to ask my question in another way, and excuse me for my English. My question is

  H1[x_, y_]=(d x + w y) + 2(c x - a y)/d + y^2 a^2 

I need to chose values for those five parameters for some reason, then, for example, I choose them like

S1 = {b -> -1.2, c -> 0.1, d -> 4, a -> - 0.8, w -> 2} 

When I try to search for the intersection values of H1 with the y axis

Solve[(H1[0, y] /. S1) == -0.5, y]  (*{{y -> -3.52859}, {y -> -0.221405}}*)  y1 = -3.5285945694153686; y2 = -0.22140543058463089; Solve[(H1[0, y] /. S1) == -1, y] (*{{y -> -3.27254}, {y -> -0.477458}}*)   y3 = -3.272542485937368;  y4 = -0.4774575140626314; 

now I have

H2[x_, y_] = (-1 + 4 (c1 + b1 y)^2 - 2 (1 + x α1 + γ1)^3 + a1 x + y β1)/(c1 + b1 y)^3 

another function with six new parameters, i need to find these parameters by solving the system

eq1 = Numerator[Factor[H2[0, y1] - H2[0, y2]]] eq2 = Numerator[Factor[H2[0, y3] - H2[0, y4]]] 

This system is with inexact parameters

Sol = Solve[({eq1, eq2} /. {b1 -> 1, γ1 -> 0.5}) == 0, {β1, c1}, Reals] 

When i use Solve, it’s giving me a solution of the same system but with inexact coefficients. My problem is when I try to solve this system

e1=H1[0, y]-H1[0, Y] e2=H2[0, y]-H2[0, Y] 

I need to find the same results of y1, y2, y3 and y4, but since Solve uses exact parameters, I don’t find the same results. I need a solution, please, thank you.

The Benefits and Drawbacks of an Air Suspension System

What Is an Air Suspension System?
An air suspension system is a style of vehicle suspension that’s powered by an electric pump or compressor that pumps air into flexible bellows that are typically made out of a textile-reinforced type of rubber. Additionally, Pro Car Mechanics describes air suspension as a replacement to the leaf suspension or coil spring system with airbags composed of polyurethane and rubber. A compressor inflates the bags to a certain pressure in order to behave like springs. Air suspension also differs from hydropneumatic suspension because it uses pressurized air instead of pressurized liquid.
What’s the Purpose of an Air Suspension System?
In most cases, air suspension is used to achieve a smooth and constant driving quality, but in some instances, sports suspensions feature an air suspensionsystem too. Similarly, air suspension replaces a conventional steel spring suspension in heavier vehicle applications, like trucks, tractor-trailers, passenger buses, and even passenger trains. Air suspension has also become popular in low-riding trucks like this gorgeous 1982 Dodge D200 Camper Special.
What Is Electronically Controlled Air Suspension?
According to the company now known as Dunlop Systems and Components, at the start of the 1990s, Dunlop developed and installed the Electronic Controlled Air Suspension (ECAS) system on the 1993 Range Rover Classic and again on the Range Rover P38A. The United Kingdom-based company developed the ECAS to include several key features:

  • Vulcanized, heavy-duty rubber air springs at each of the vehicle’s wheels
  • An air compressor in the vehicle’s trunk or under the hood of the vehicle
  • A storage tank for compressed air, which allows you to store air at around an average of 150 PSI
  • Valve blocks which direct air to the four springs from the storage reservoir through a set of solenoids, valves, and o-rings
  • ECAS computer that communicates between the vehicle’s main computer to calculate where to direct air pressure
  • Air pipes connecting from the storage tank to the air springs that channel the flow of air throughout the rear air suspensions system
  • A desiccant-filled drier canister to keep the internal recesses of the system dry

The electronically controlled air suspension also features height sensors that are based on sensing resistance in contact with the terrain on all four of the vehicle’s corners to provide height reference for all corners. Additionally, further advancements are beginning to feature some Electronic Control Units (ECUs) that are able to fit under the vehicle’s floorboard, making air suspension more widely featured in everyday driving.
The Benefits and Drawbacks of Air Suspension Systems
According to Future Marketing Insights, the total value of the air suspension market at the end of 2017 was around $4.3 million. So whether it’s a manual or electronic air suspension system, the benefits can greatly improve the ride of the vehicle. Take a look of some of the benefits of front air suspenions:

  • More driver comfort due to the reduction in noise, harshness, and vibration on the road that can cause driver discomfort and fatigue
  • Less wear and tear on the suspension system due to reduced harshness and vibration of heavy-duty driving
  • Trailers last longer with air suspension because the system components don’t take on as much vibration
  • Air suspension reduces the tendency of short wheelbase trucks to bounce over rougher roads and terrain when the vehicle is empty
  • Air suspension improves the ride height based on the load weight and a vehicle’s speed
  • Higher corner speeds due to air suspension being better suited to the surface of the road

Air suspension increases the transport capabilities of trucks and trailers by providing a better grip that levels the entire suspension. An air suspension system can also be adjusted for feel, so drivers can choose between a softer feel for highway cruising or a harder ride for improved handling on more demanding roads.
In the case of hauling heavy loads, air suspension offers more consistency and keeps all wheels even. The air suspension system keeps trucks level from side to side, especially in cases where cargo is difficult to level. This results in reduced body roll when turning corners and curves.
Even with the benefits of an air suspension system, Driving Tests New Zealand suggests several drawbacks. Some of these disadvantages that so and so reports include:

  • The initial costs of purchasing and installing an air suspension system — air suspension can also sometimes reach three times the cost in repairs as a leaf suspension system over 10 years’ time
  • Fuel overheads for running air compressor for occasionally pumping air to the correct pressure
  • Fuel efficiency can suffer from the heavier weight of air suspension over the weight of leaf suspension
  • An air suspension system’s vulnerability to air leaks can result in malfunctions

Some of the drawbacks of air suspension systems are because of some of the mechanical issues they can be vulnerable to. Several of the common issues with air suspension systems that can require repair include:

  • Rust or moisture damage from the inside that can lead to the air struts or bags to malfunction
  • Failure of the air suspension tubing connecting the air struts or bags to the air system
  • Air fitting failure resulting from initial fitting or infrequent use
  • Compressor burn out due to air leaks in the springs or air struts from the compressor constantly engaging to maintain the proper air pressure

Even with these common mechanical problems, the benefits can far outweigh the drawbacks.

Cinemachine camera not working in Photon multiplayer system in Unity

I am fairly new to the whole multiplayer game mechanics, but I made a simple car controller and added cinemachine camera as a child to the car and then made it into a prefab, and I instantiate the car prefab in the game…..but every time I do that, the camera shifts to the other car…..

I’ve added all the important stuff like photon view and transform. I’ve also changed the script to check ‘if.mine’,

but still the camera shifts to the other second player while I control the first….

Can someone please help me to find a solution……

2D Armor/Weapon System (Paperdolling)

I´m currently working on a 2D RPG where you should be able to compose your character from diffrent armor/weapon parts. For example the character can wear a "wooden helmet" and a "chain armor".

One technique I discovered is the so called "paperdolling" where you split every component (helmet, body armor, legs, weapon …) into its own spritesheet and draw it on top of a naked base sprite.

However im not really sure how I can handle the following requirement: I want to be able to use the same weapon sprite for diffrent poses / attacks. First I thought of some kind of "mount system" where I use a specific color to mark my "anchor points" on the sprites and generate some sort of metadata file which I can load into my game (maybe its similar to bone animations?). With this approach I know the anchor point(s) for every sprite and to which sprite they belong.

  1. Do you think this is a sensible approach ?
  2. Are there other techniques I could use to get the same results ?

Funny Viral Video Site Like Youtube with Internal Ads System LMAO Video!

If you have a social following, you could make a lot of money with this site. Accepted by Adsense and includes internal ads system for users to buy ads. Everyone loves funny videos, upload and share!


Amazing domain name and website offering funny videos that both admin and visitors can upload to populate the site. Admin panel full of features to help you build a massive collection of funny videos that people will share on social…

Funny Viral Video Site Like Youtube with Internal Ads System LMAO Video!

Can I register domain names with a unique extension in Ethereum Name System once and never pay for renewal?

Several months ago in an interview with Vitalik Buterin I heard that you can register a domain name in Ethereum Name System (ENS) once and hold it as long as you want without being dependent on a registrar. I then searched the ENS site a bit and found that they were offering .zil and .crypto domain registration for 25$ . Now they seem to offer only the registration of .eth domains which will be required to renew.

Can I register domain names with a unique extension (not .eth) in Ethereum Name System once and hold them as long as I want without paying for renewal? The extension is unique and not present in any extension lists offered by other traditional registrars.

Can I connect a domain name registered in Ethereum Name System to any hosting rather than uploading the website to IPFS? As in ENS it is required to "upload your website to IPFS" which is a "peer-to-peer network for storing and sharing data in a distributed file system" and the advantages of a distributed website storage and serving over centralized storage are unclear.

WordPress hack from “system” post?

Our WordPress site (maintained by a third party) was hacked recently with the pharma redirects from Google searches.

We were not sure how they got in, but there were lots of login attempts on an "admin" account and some other name based accounts (e.g. "bob"). The third party company added the Sucuri Security plugin so we could see this after the first hack.

So we removed that account, and also added an IP whitelist to the .htaccess file for wp-login.php so that vulnerability scanners could not access it.

I also checked we had upgraded to the latest WordPress (version 5.7.2) and PHP (7.4). We also changed all the passwords on existing accounts.

This morning we had an error as the mo.php file had been incorrectly edited and the site was down.

I checked and we found more files in /wp-admin had been added, but there were no user logins to WordPress. There were these two "system" entries from a malicious IP: hack details

I am wondering if there is another weak route they have found. There is no user on our site called ‘security’.

Anything else I need to fix?