Perovskite refers to a specific class of materials that have a characteristic crystal structure named after the mineral perovskite (CaTiO3), which was first discovered in the Ural Mountains in Russia. The general formula for perovskite-structured materials can be expressed as ABX3, where: - A is a cation (a positively charged ion) that occupies the larger dodecahedral sites.

The Urbach tail refers to a particular feature of the optical absorption edge in disordered or amorphous semiconductor materials and insulators. It describes the exponential tail of the absorption spectrum that appears just below the bandgap energy of a material. In ideal crystalline semiconductors, the absorption edge is typically sharp and well-defined due to the periodic lattice structure. However, in disordered materials, defects, impurities, and localized states within the bandgap can lead to a broadening of the absorption spectrum.

The Sodium Fusion Test, also known as the Lassaigne's Test, is a qualitative analytical technique used primarily in organic chemistry to detect the presence of certain elements in organic compounds, specifically nitrogen, sulfur, and halogens (such as chlorine, bromine, and iodine). ### Procedure: 1. **Fusion with Sodium**: A small amount of the organic compound is mixed with an excess of metallic sodium in a dry test tube and heated strongly.

"Dye-and-pry" commonly refers to a technique used in the field of chemistry and materials science, particularly in the study of polymers. However, the term can also be associated with methods in biology, such as gene expression analysis. In the context of polymers, dye-and-pry typically involves labeling or tagging a polymer with a fluorescent dye to study its properties. This method can help in understanding the interactions of polymers, their stability, or their behavior under various conditions.

A flat-panel detector (FPD) is a type of imaging device primarily used in medical radiography and fluoroscopy, as well as in industrial applications. It serves as an electronic sensor that converts x-ray photons into a digital image, allowing for high-quality images to be captured quickly and efficiently. ### Key Characteristics: 1. **Structure**: Flat-panel detectors typically consist of a rectangular flat panel that houses an array of sensors, most commonly made of either amorphous silicon or selenium.

Hydrogen leak testing is a method used to detect and locate leaks in systems or components that contain hydrogen gas, which is often used in various industrial and research applications, including hydrogen fuel cells, electrolyzers, and storage tanks. Due to the small molecular size of hydrogen, it can easily escape through small openings and defects, making leak detection critical for safety, efficiency, and environmental protection.

Thermal acoustic imaging is a hybrid imaging technique that combines principles from both thermal imaging and acoustics to analyze and visualize the thermal and material properties of an object or medium. The underlying principle of this technique generally involves the detection of temperature variations in a material, which can be caused by internal defects, stress, or other changes in the material's properties.

Time-of-flight ultrasonic determination of 3D elastic constants is an experimental technique used to measure the elastic properties of materials, particularly in three dimensions (3D). This method utilizes ultrasonic waves to assess how a material responds to stress and strain, allowing for the calculation of its elastic constants, which are fundamental parameters that describe the material's mechanical behavior.

Tubular NDT (Non-Destructive Testing) refers to a set of testing techniques specifically designed to evaluate the integrity and properties of tubular structures, such as pipes, tubes, and casing in various industries, including oil and gas, construction, and manufacturing. Non-destructive testing methods allow for the assessment of materials and components without causing damage, which is crucial for maintaining safety and reliability.

Pig iron is a raw material produced from the smelting of iron ore in a blast furnace. It typically contains around 3-4% carbon, along with varying amounts of other elements such as manganese, silicon, sulfur, and phosphorus. The name "pig iron" is derived from the traditional method of casting iron into molds that resemble a sow and her piglets. Pig iron is an intermediate product in the production of wrought iron and steel.

A leak-down tester is a diagnostic tool primarily used in automotive mechanics to assess the condition of an internal combustion engine. It measures the ability of an engine’s piston rings, valves, and head gaskets to hold pressure, helping to identify potential leaks or issues within the engine’s cylinders. ### How It Works: 1. **Setup**: The engine is usually brought to a specific position (usually top dead center) for the cylinder being tested.

Rigid body mechanics is a branch of classical mechanics that deals with the motion and behavior of rigid bodies. A rigid body is an idealized solid object that does not deform under the action of forces; the distances between any two points in the body remain constant regardless of external forces or moments applied to it. The main aspects of rigid body mechanics include: 1. **Kinematics**: The study of the motion of rigid bodies without considering the forces that cause the motion.

Terotechnology is a branch of engineering and management that focuses on the lifecycle management of physical assets. This concept encompasses the processes of acquisition, operation, maintenance, and disposal of assets, with the aim of maximizing their performance, reliability, and safety while minimizing costs over their lifespan. The field of terotechnology integrates various disciplines, including engineering, economics, and management, to ensure that assets such as machinery, equipment, and infrastructure are effectively managed throughout their entire lifecycle.

The Dick Volz Award is an accolade presented to honor outstanding achievement in the field of electrical and computer engineering and is typically associated with the University of Idaho. Named after Dick Volz, a long-serving faculty member in the university's electrical and computer engineering department, the award recognizes individuals for their professional contributions, service, and impact on the engineering community or their respective fields.

The Timoshenko Medal is an award established to recognize outstanding contributions in the field of mechanical engineering, particularly in applied mechanics. It is named after the renowned Russian-American engineer and educator, Stephen Timoshenko, who is often referred to as the "father of modern engineering mechanics." The medal is awarded by the American Society of Mechanical Engineers (ASME) and is intended to honor individuals who have made significant achievements in the areas of theory, research, or education in applied mechanics.

Red Bull Flugtag is an entertainment event organized by Red Bull in which participants construct homemade flying machines and attempt to launch them off a platform into a body of water. The event combines creativity, engineering, and a sense of fun, as teams often design their aircraft to fit a particular theme or concept. Competitors are judged on various criteria, including the creativity and design of their crafts, the distance they achieve when launched, and the overall spectacle of their flight.

Sandra Aguebor is a notable Nigerian figure recognized for her work in the automotive industry. She is particularly celebrated for being one of the first female mechanics in Nigeria and for her efforts to break gender stereotypes in a traditionally male-dominated field. Aguebor is the founder of the Lady Mechanic Initiative, an organization aimed at training women and girls in automotive skills, thereby empowering them economically and promoting gender equality in the workforce.

Engineering for Change (E4C) is a nonprofit organization that focuses on promoting engineering solutions to address global challenges, particularly in underserved communities. It aims to harness the skills and creativity of engineers and technologists to create sustainable and impactful solutions that improve the quality of life for people in need.

SAWE stands for the Society of Allied Weight Engineers. It is a professional organization dedicated to promoting the discipline of weight engineering within various industries, particularly in aerospace, automotive, and defense. The society provides resources for weight engineers, including education, training, standards, and networking opportunities. SAWE also focuses on advancing the practice of weight engineering to improve design processes, enhance product performance, and support cost-effective and efficient project management.

A barrel nut is a type of fastener that is often used in conjunction with a bolt to secure two or more components together. It is typically a cylindrical piece of metal with internal threads that allow a bolt to be screwed into it. Barrel nuts are commonly found in furniture assembly, especially in items like flat-pack furniture, where they provide a secure connection between panels without requiring access to the other side of the joint.