Patulous Eustachian tube (PET) is a condition in which the Eustachian tube, which connects the middle ear to the back of the throat, remains abnormally open. The Eustachian tube plays a vital role in equalizing air pressure in the middle ear and draining fluids. In a healthy state, the tube opens and closes as needed, such as when swallowing or yawning.

In the context of medicine, "recruitment" can refer to several concepts, depending on the specific area of focus: 1. **Clinical Trials**: Recruitment often pertains to the process of enrolling participants in clinical studies. This involves identifying and selecting eligible candidates who meet certain criteria for the study. Effective recruitment is crucial for ensuring that clinical trials have sufficient participants to produce reliable and valid results.

Ella Havelka is an Australian dancer, actress, and choreographer, recognized for her work in various dance styles and performances. She gained notable attention for being a part of the Australian dance scene and has also made contributions to film and television. Havelka is celebrated for her skill and creativity, often exploring themes related to culture and identity in her work.

Headphones are a pair of small speakers that are worn on or over the ears, designed to provide audio output directly to the listener. They allow individuals to listen to music, podcasts, audio books, or any other sound sources without disturbing others nearby. Headphones come in various designs and types, including: 1. **Over-ear headphones**: These have large earcups that enclose the ears, providing good sound isolation and comfort for long listening sessions.

Models of deafness refer to the various frameworks and theories that describe and interpret the experience of deafness, its implications, and how society perceives and interacts with individuals who are deaf or hard of hearing. Different models reflect varying attitudes towards deafness, leading to distinct approaches in education, communication, and social integration.

The term "risk quotient" generally refers to a numerical expression that quantifies the level of risk associated with a particular exposure or activity in relation to a reference point. It often expresses the ratio of exposure to a benchmark that is considered safe or acceptable.

The Scheimpflug principle is an important optical principle that relates to the alignment of the lens plane, the image plane, and the object's plane in a photographic or imaging system. It is named after the German ophthalmologist Theodor Scheimpflug. The key concept of the Scheimpflug principle is that when the plane of focus (image plane) is tilted relative to the lens axis, the full depth of field can still be maintained effectively.

A Schoenberg hexachord is a concept introduced by the composer Arnold Schoenberg, which plays a key role in his twelve-tone technique and theory of music. Specifically, it refers to a collection of six pitches that form a set, serving as one of the building blocks for melodies and harmonies in his compositions.

The Second Principal Meridian is one of the principal meridians used in the Public Land Survey System (PLSS) in the United States. Principal meridians are the key reference lines used in the surveying and division of land. Each meridian serves as a baseline for establishing townships and ranges, which help in the systematic parceling of land primarily in the western United States. The Second Principal Meridian, established in 1815, runs through a specific location in the U.S.

Sebastian Elbaum is a computer scientist known for his contributions in areas such as software engineering, software testing, and program analysis. He has published research on topics like automated program repair, software quality, and the integration of testing and debugging tools.

Sébastien Candel is a notable French physicist known for his work in the field of laser physics and optics. He has made significant contributions to the study of light-matter interactions, laser technologies, and related applications. Candel has been involved in various research projects and has published numerous scientific papers throughout his career.

Secondary flow refers to the flow patterns that occur in a fluid dynamics context, particularly in situations where the primary flow direction is established by external forces or conditions, such as pressure gradients or gravity. This concept is commonly discussed in the contexts of: 1. **Turbulence**: Secondary flows often arise in turbulent conditions, where the fluid exhibits complex and chaotic motion. These flows can include vortices and other rotational motions that are perpendicular to the main flow direction.

Laser-Heated Pedestal Growth (LHPG) is a crystal growth technique primarily used for the synthesis of high-quality single crystals of materials, particularly semiconductors and other advanced materials. The technique utilizes a focused laser beam to create a localized heating zone at the interface between a solid crystal and a liquid melt, known as the pedestal.

Lightweighting refers to the process of reducing the weight of a product, structure, or component while maintaining or enhancing its performance, safety, and structural integrity. This practice is particularly relevant in various industries, including automotive, aerospace, construction, and consumer goods. The key objectives of lightweighting include: 1. **Fuel Efficiency**: In the automotive and aerospace industries, lighter vehicles consume less fuel, leading to reduced operational costs and lower greenhouse gas emissions.

MEMS (Micro-Electro-Mechanical Systems) thermal actuators are tiny devices that convert thermal energy into mechanical motion at the micro scale. These actuators leverage the principle of thermal expansion, where materials expand or contract in response to temperature changes, to produce movement.

Necking in engineering refers to a phenomenon that occurs during the deformation of materials, particularly in ductile materials like metals, under tensile stress. When a material is stretched beyond its yield strength, it begins to deform plastically. As the material is pulled, it may eventually reach a point where localized deformation occurs, leading to a reduction in cross-sectional area in a specific region. This localized thinning is known as necking.

Puncture resistance refers to the ability of a material or product to withstand puncturing forces without being penetrated or damaged. This property is particularly important in various applications, including: 1. **Footwear**: Safety shoes often feature puncture-resistant soles to protect the wearer's feet from sharp objects such as nails or shards of glass. 2. **Gloves**: Puncture-resistant gloves are used in industries where workers handle sharp tools or materials, providing protection against cuts and punctures.

Reflectance Difference Spectroscopy (RDS) is an optical technique used to analyze the electronic and optical properties of materials, particularly thin films and surfaces. The method involves measuring the difference in reflectance of light polarized in different directions when it is incident on a sample. ### Key Features of Reflectance Difference Spectroscopy: 1. **Polarization Sensitivity**: RDS relies on the fact that the reflectance of a surface can vary depending on the polarization of the incident light.

Rigid unit modes (RUMs) are a concept primarily found in the study of frameworks like zeolites, metal-organic frameworks (MOFs), and certain types of crystalline materials. They refer to the vibrational modes of these structures that involve the movement of entire rigid units (such as tetrahedral or octahedral clusters) without changing the overall connectivity or arrangement of the material's framework.

Stopping power in the context of particle radiation refers to the ability of a material to reduce the energy of charged particles—such as electrons, protons, or alpha particles—passing through it. It is defined as the rate at which the kinetic energy of the particles is lost per unit distance traveled in the material. Stopping power is an important concept in radiation physics, medical physics, and radiation protection.