A web-based Computer algebra system

A Computer Algebra System (CAS) is a software program or system designed to perform symbolic mathematical computations. Unlike numerical computing, where values are represented and manipulated in a numerical form, CAS deals with mathematical expressions in symbolic form. This means that CAS can manipulate algebraic expressions, equations, and mathematical objects symbolically, allowing for operations like … Read more

Physical constants and functions in Comsol.

COMSOL Multiphysics is a software platform used for modeling and simulating physics-based systems. It is particularly popular for its capabilities in multiphysics simulation, which means it can handle simulations involving multiple physical phenomena simultaneously. This includes, but is not limited to, heat transfer, fluid dynamics, electromagnetics, structural mechanics, and chemical reactions.Users can create models in … Read more

Enrichment Process for Separating Deuterium from Water

Deuterium, often referred to as “heavy hydrogen,” is an isotope of hydrogen with one proton and one neutron in its nucleus. Separating deuterium from water, which contains both regular hydrogen (H) and deuterium (D), is known as isotopic separation or enrichment. One widely used method for this separation is hydrogen distillation, a multi-stage process leveraging … Read more

How to find the IPs to cloudflare?

There are many IP addresses that serve as reverse proxies to Cloudflare. Cloudflare is a popular content delivery network (CDN) and security service provider that offers protection and performance enhancements to websites. When a website uses Cloudflare’s services, incoming traffic is often routed through Cloudflare’s reverse proxy servers before reaching the website’s origin server. This … Read more

404 Error for apt update on Debian 9

If you’re encountering 404 errors when running apt update on Debian 9, it’s likely due to the fact that Debian 9 (code-named “Stretch”) reached its end of life on July 18, 2020. When a Debian version reaches its end of life, the repositories are typically archived and no longer receive updates. As a result, running … Read more

Linux server security for SSH

Anyone only needs to know these four elements to access your Linux server: IP address, port, username, and password. Clearly, the security of these four components is the baseline we need to protect. Let’s analyze them one by one: IP Address: Malicious scripts can randomly attempt and scan IP ranges, so it can be considered … Read more

Every polynomial equation with complex coefficients has at least one root in the complex number field

Every polynomial equation with complex coefficients has at least one root in the complex number field. This fundamental result is known as the Fundamental Theorem of Algebra. It states that every non-constant polynomial equation of degree greater than or equal to 1 has at least one complex root. The complex number field, denoted as ℂ, … Read more

Clipboard in Javascript

To get the content from the clipboard in JavaScript, you can use the Clipboard API, which provides a way to interact with the clipboard. Here’s how you can do it: javascriptCopy code Here’s a breakdown of the code: Keep in mind that clipboard access in browsers is subject to user permissions and security considerations. In … Read more

IPv6 on IPv4

An IPv6 tunnel broker is a service or organization that provides a way for users to access the IPv6 internet when their internet service provider (ISP) does not offer native IPv6 connectivity. This is typically done by encapsulating IPv6 packets within IPv4 packets and routing them through a tunnel to a remote server that has … Read more