"Spectrochimica Acta Part B" is a peer-reviewed scientific journal that publishes research articles and reviews in the field of spectroscopy. It is part of the larger "Spectrochimica Acta" series, which is known for focusing on various aspects of spectroscopic techniques and applications. Part B typically emphasizes specific areas such as molecular spectroscopy, photochemistry, and related topics that deal with the interactions between light and matter.

X-ray standing waves (XSW) refer to a phenomenon that occurs when X-rays are diffracted from a crystal or a periodic structure in such a way that they create standing wave patterns. This effect can be understood through the principles of wave interference, where two waves of the same frequency traveling in opposite directions combine to form a stationary wave pattern.

Serpens South is a molecular cloud in the constellation of Serpens, which is notable for being one of the few regions in the sky where star formation is actively taking place. It is part of a larger structure known as the Serpens constellation complex, which is characterized by dense, cold regions of gas and dust where new stars are being born. The cloud is particularly interesting to astronomers because it hosts a number of young stellar objects and protostars, offering insights into the processes of star formation.

The Storm Prediction Center (SPC) categorizes severe weather risk levels on a scale from 1 to 5, with Level 1 (Marginal) being the lowest risk and Level 5 (High) being the highest. Each level can be associated with specific severe weather events, such as tornadoes, severe thunderstorms, and flash flooding.

A "derecho" is a widespread and long-lived windstorm associated with a band of rapidly moving showers or thunderstorms. Derechos can produce straight-line winds that exceed 58 mph and can cause significant damage, similar to that of tornadoes. A list of derecho events typically includes significant occurrences of derechos throughout history, often highlighting the date, location, and the impacts caused by the storm.

The weather in 2021 was marked by a variety of significant events and trends around the world. Here are some key highlights: 1. **Extreme Heatwaves**: The summer of 2021 saw unprecedented heatwaves, particularly in the Pacific Northwest of the United States and Canada. Cities like Portland and Seattle experienced record-breaking temperatures.

As of my last knowledge update in October 2023, I cannot provide real-time weather information. However, I can inform you about significant weather events and patterns that were noted throughout 2023 up until that time. Throughout the year, the world experienced various weather phenomena, including: 1. **Heatwaves**: Many regions faced exceptionally high temperatures, with heatwaves impacting Europe, North America, and parts of Asia.

The Prairie and Arctic Storm Prediction Centre (PASPC) is a division of Environment and Climate Change Canada (ECCC) that is responsible for monitoring and forecasting weather conditions in the Prairie provinces (Alberta, Saskatchewan, and Manitoba) and the Arctic regions of Canada. The center focuses on severe weather events, including thunderstorms, tornadoes, winter storms, and other hazardous weather phenomena.

A valve audio amplifier, also known as a tube amplifier, is a type of audio amplification device that uses vacuum tubes (or valves) to increase the power of audio signals. These amplifiers were widely used before the advent of solid-state technology and still have a dedicated following among audiophiles and musicians today.

A choke valve is a type of valve used to regulate the flow of fluids, typically in applications involving oil and gas production, water treatment, or other industrial processes. It works by restricting the flow area, which allows operators to control the pressure and flow rate of the fluid passing through the system. Choke valves are often used to manage the extraction of hydrocarbons from reservoirs, particularly in wellhead control systems.

A needle valve is a type of valve used to precisely control the flow of fluids (liquids and gases) in a pipeline. It features a slender, tapered, needle-like plunger that fits into a seat, allowing for fine adjustments to the flow rate. Here are some key characteristics and functions of needle valves: 1. **Design**: Needle valves have a simple design, typically consisting of a body, a stem with a pointed tip, and a seat.

Rolamite is a mechanical device that functions as a low-friction bearing or linear motion guide. It was invented by the American engineer William M. McGowan in the early 1960s. The design features a unique combination of rolling and sliding elements that allows for smooth, controlled motion. The Rolamite mechanism consists of a pair of curved segments on which small rollers travel, enabling motion with minimal friction.

The LAPCAT A2 (Long-term Advanced Propulsion Concept for Air Transport) is a conceptual aerospace vehicle developed by Reaction Engines Limited. It is designed as a high-speed air transport system that seeks to combine the functionality of a subsonic airliner with the speed of a hypersonic vehicle. The LAPCAT A2 aims to achieve cruise speeds of around Mach 4, which is four times the speed of sound, enabling long-distance travel that could significantly reduce flight times.

A supersonic business jet (SSBJ) is an advanced type of business aircraft designed to travel faster than the speed of sound, typically exceeding Mach 1 (approximately 1,235 kilometers per hour or 767 miles per hour at sea level). These jets aim to significantly reduce flight times on long-distance travel, allowing business travelers to spend less time in transit and more time at their destinations.

Human-powered transport refers to modes of transportation that rely on human physical effort to operate, rather than engines or motors. Common examples include: 1. **Bicycles**: One of the most popular forms of human-powered transport, bicycles use pedaling to propel the rider. 2. **Walking**: The most basic form of human-powered transport, used for short distances. 3. **Running**: Similar to walking but at a faster pace, often used for recreational activities or short commutes.

A Basic Utility Vehicle (BUV) is a type of vehicle designed primarily for utility purposes, typically featuring a simple, rugged design that prioritizes functionality over luxury or aesthetics. BUVs are often characterized by their capability to perform a variety of tasks, particularly in rural or off-road environments. They may be used for transporting goods, people, or agricultural equipment.

Environmental design in rail transportation refers to the integration of environmental considerations into the planning, design, construction, and operation of rail systems. It aims to minimize the ecological footprint of rail infrastructure and operations while enhancing safety, efficiency, and user experience. Key aspects of environmental design in rail transportation include: 1. **Sustainable Materials**: Choosing eco-friendly materials for construction and maintenance that have a reduced environmental impact.

The Nidderdale Greenway is a scenic walking and cycling route located in North Yorkshire, England. It utilizes a former railway line that once connected Harrogate and Ripon, providing an accessible pathway through beautiful countryside. The greenway is approximately 13 miles long and is suitable for walkers, cyclists, and families, making it a popular destination for outdoor enthusiasts. The route offers a safe and traffic-free environment, featuring a mix of natural landscapes, wildlife, and various points of interest along the way.

The mode of transport refers to the various means or methods used to move people or goods from one location to another. Different modes of transport enable different speeds, costs, and efficiencies, and can be categorized into several main types: 1. **Land Transport**: This includes vehicles that travel on roads and tracks. Examples are: - **Road transport**: Cars, buses, trucks, motorcycles, bicycles. - **Rail transport**: Trains, subways, trams.

"Vehicles by period" typically refers to the classification or categorization of vehicles based on specific historical periods or eras. This classification can encompass a wide range of factors, including design styles, technological advancements, manufacturing techniques, and societal changes that influenced vehicle production and use. Here are some common periods in automotive history: 1. **Early Auto Era (Late 19th to Early 20th Century)**: - The advent of the automobile with vehicles powered by steam, electricity, and gasoline.