All articles starting with S

Semen

Semen, or seminal fluid, is the whitish-gray ejaculate made of sperm from the testicles plus seminal vesicle and prostate secretions (65-75% vesicle fluid, 25-30% prostate, 1-5% sperm). WHO reference values and standardized semen analysis define its clinical use.

Semen analysis

Semen analysis, standardized by the WHO laboratory manual (6th edition, 2021), measures semen volume, sperm concentration, motility, and morphology; its 5th-centile reference limits from fertile men do not by themselves diagnose infertility.

Semen collection

Semen collection: veterinary techniques for obtaining sperm from male animals, chiefly artificial vagina, manual stimulation, and electroejaculation, plus epididymal recovery; method choice affects semen quality, repeatability, and animal welfare.

Sep 29, 2026

Semen cryopreservation

Semen cryopreservation is a clinical andrology method that mixes sperm with cryoprotectants such as glycerol and stores them in liquid nitrogen, mainly to preserve fertility before cancer treatment.

Semen Novikov

Semen Novikov (Semen Sergeevich Novikov) is a Ukrainian-born Greco-Roman wrestler, born 1997 in Kharkiv, competing at 87 kg for Bulgaria; 2024 Paris Olympic champion, 2023 world champion, 2020 European champion for Ukraine.

Semen Preservation

Semen preservation keeps semen viable outside the body by cooling, chemical agents, or freezing (cryopreservation, sperm banking). Key milestones: Spallanzani 1776, glycerol cryoprotection 1949, first human live birth 1953, liquid nitrogen storage 1963.

Semen quality

Semen quality describes measurable ejaculate parameters (volume, sperm concentration, motility, morphology) assessed by WHO manual semen analysis; sixth-edition lower limits include 16 million/mL concentration and 4% normal forms, but results cannot alone distinguish fertile from infertile men.

Sep 19, 2026

Semenkare

Semenkare, whose full titulary is Semenkare Nebnuni, was a poorly attested pharaoh of Egypt's Thirteenth Dynasty in the 18th century BC, known chiefly from king lists.

Semenogelin

Semenogelin (SgI/SEMG1, SgII/SEMG2): seminal vesicle gel-forming proteins forming the semen coagulum, cleaved by PSA/KLK3 to liquefy semen, bind zinc, inhibit sperm motility, and serve as forensic semen markers.

Sep 19, 2026

Semenre

Semenre, also rendered Semenenra, is a poorly attested king of Egypt's Second Intermediate Period, known only from one damaged entry in the Turin King List, dated around 1601–1600 BC.

Sep 19, 2026

Semerkhet

Semerkhet, also known as Horus Semerkhet or Semempses, was the seventh pharaoh of Egypt's First Dynasty, ruling around 2925–2916 BC and buried in Tomb U at Abydos.

Semester (eclipse cycle)

The semester is an eclipse cycle of about 173.31 days, half an eclipse year, the time the Sun takes to travel from one lunar node to the other.

Oct 22, 2026

Semetey

Semetey (Семетей) is the second part of the Kyrgyz Manas epic trilogy, whose hero, Manas's son, avenges his father, reunites the tribes, and loses power through betrayal.

SemEval

SemEval (International Workshop on Semantic Evaluation) is a natural language processing workshop series, begun in 1998 as SENSEVAL for word sense disambiguation, where teams compete on shared evaluation tasks.

Semey

Semey (Семей), formerly Semipalatinsk until 2007, is a city of about 314,000 in northeastern Kazakhstan on the Irtysh River, administrative center of Abay Region since 2022, founded 1718, near the Semipalatinsk nuclear test site.

Semeykin (Martian crater)

Semeykin, a 73.51 km crater on Mars at 41.51°N, 8.75°E in Arabia Terra, named 1982 for Soviet astronomer Boris Semeykin; studied as a modified impact structure and candidate volcanic collapse near the dichotomy boundary.

SEMI

SEMI, originally Semiconductor Equipment and Materials International, is a global semiconductor industry association founded in 1970, known for its SEMICON expositions and more than 1,000 technical standards.

Semi Ajayi

Semi Ajayi (Oluwasemilogo Adesewo Ibidapo Ajayi), Nigerian centre-back born 1993 in Crayford, England; ex-Charlton, Arsenal academy, Cardiff, Rotherham, West Brom; now Hull City; 33 Nigeria caps, AFCON 2023 silver medalist.

Semi Kunatani

Semi Kunatani (Semi Kunabuli Kunatani), Fijian flanker born 1990; Rio 2016 Olympic sevens gold medallist in Fiji's first ever Olympic medal, 10 Test caps, later Toulouse, Harlequins, Castres and MLR.

Semi Ojeleye

Semi Ojeleye (Jesusemilore Talodabijesu Ojeleye), born 1994, American forward from Kansas; Duke then SMU, AAC Player of the Year 2017; NBA 2017-22 with Celtics, Bucks, Clippers; now in Europe.

Semi Radradra

Semi Radradra is a Fijian rugby player, born in 1992, who played international league for Fiji and Australia and won Olympic sevens gold at Tokyo 2020.

Semi-acoustic guitar

The semi-acoustic guitar, also called a semi-hollow or hollow body electric guitar, is an electric guitar with a solid wood center block inside a partly hollow body.

Semi-active suspension

Semi-active suspension is a vehicle suspension in which an electronic controller continuously adjusts the shock absorbers' damping to road conditions and load, improving comfort while consuming little power.

Semi-arid climate

The semi-arid climate, or steppe climate (Köppen BS), is a dry climate intermediate between humid and arid, with aridity index 0.2 to 0.5, supporting grassland and scrub.

Semi-automatic firearm

A semi-automatic firearm, also called a semi-automatic gun, is a gun that reloads itself automatically after each shot but fires only one round with each pull of the trigger.

Semi-Automatic Ground Environment

The Semi-Automatic Ground Environment (SAGE) was a US continental air defense system in which radars fed track data to AN/FSQ-7 computers that directed interceptors, fully deployed in 1963.

Semi-automatic pistol

A semi-automatic pistol, also called a self-loading pistol, is a magazine-fed handgun firing one cartridge per trigger pull, distinguished from revolvers and fully automatic pistols.

Semi-automatic rifle

A semi-automatic rifle is a rifle that fires one shot per trigger pull, automatically chambering the next round; the first was built in 1885 by Ferdinand von Mannlicher.

Semi-automatic switchboard

A semi-automatic switchboard, also called a dial-system or semi-mechanical exchange, was telephone switching in which an operator keyed the wanted number and automatic machinery set up the connection.