F90
F90 may refer to: In science and technology:- [[Alacrite]]
- [[Beechcraft King Air F90]]
- [[Fortran 90]]
- F90 (ICD-10 code)
- [[F90 assault rifle]]
- [[HMS Brilliant (F90)]]
- [[BMW M5 (F90)]]
- [[F90 Gundam F90]]
Science and technology
Alacrite
Alacrite, also designated as F90 and conforming to ASTM F90 (UNS R30605), is a cobalt-based superalloy renowned for its exceptional high-temperature strength and resistance to corrosion, oxidation, and sulfidation. This wrought alloy, often referred to interchangeably with Haynes 25 or L-605, features a nominal chemical composition of approximately 51% cobalt (balance), 20% chromium, 15% tungsten, 10% nickel, up to 3% iron, 1.5% manganese, 0.4% silicon, and 0.1% carbon, along with trace elements such as phosphorus and sulfur.[1][2][3] Developed in the early 1950s by the Haynes Stellite Company, Alacrite was engineered specifically for extreme thermal environments in aerospace and industrial applications, building on advancements in cobalt-based metallurgy during the post-World War II era.[4] The alloy's formulation emphasizes solid-solution strengthening from tungsten and chromium, enabling robust performance without reliance on precipitation hardening, which distinguishes it from many contemporary superalloys.[5] Alacrite's unique properties include superior creep resistance and tensile strength at elevated temperatures, maintaining structural integrity up to 980°C for continuous service and short-term exposures to 1,100°C, alongside excellent oxidation resistance and fabricability.[1][6] Compared to nickel-based superalloys, it offers enhanced weldability and resistance to galling, making it particularly suitable for components subjected to thermal cycling and corrosive gases.[1] Due to its biocompatibility, Alacrite is also used in surgical implants, such as orthopedic components and prosthetic devices.[3] In practice, Alacrite finds primary use in turbine blades, vanes, and hot-section parts of jet engines and industrial gas turbines, where its ability to endure aggressive environments ensures reliability in propulsion systems.[7][5]Beechcraft King Air F90
The Beechcraft King Air F90 is a twin-engine turboprop aircraft developed as an advanced variant in the King Air 90 series, featuring a T-tail configuration borrowed from the King Air 200 for improved performance. The prototype first flew on January 16, 1978, with production commencing in 1979 and continuing until 1983, during which approximately 203 units were built; an additional 33 F90-1 variants followed until 1985, for a total of about 236 aircraft produced. Designed primarily for business and utility roles, the F90 combined the fuselage and wings of the earlier E90 model with enhancements for higher speed and efficiency, including a pressurized cabin accommodating 7 to 9 passengers in a comfortable, low-noise environment. The F90 is powered by two Pratt & Whitney Canada PT6A-135 turboprop engines, each rated at 750 shaft horsepower (shp), mounted on the low-wing structure with retractable tricycle landing gear. Key performance characteristics include a maximum cruise speed of 265 knots, a normal range of approximately 1,235 nautical miles with reserves, and a service ceiling of 31,000 feet, enabling operations above most weather conditions. These specifications position the F90 as a versatile light twin turboprop, offering short-field capabilities and reliable handling suitable for regional flights. A single variant, the F90-1, was introduced in 1983 to address hot-and-high performance limitations, incorporating upgraded PT6A-135A engines with redesigned cowlings, hydraulic landing gear, and a triple-fed electrical system for enhanced climb rates and overall efficiency. The F90 series has been employed in diverse roles, including corporate transport for executive travel, air ambulance services for medical evacuations, and military utility missions, such as the U.S. Army's C-90A for light cargo and personnel transport.Fortran 90
Fortran 90 represents a significant revision of the Fortran programming language, designed to modernize its capabilities for scientific and numerical computing while maintaining compatibility with prior standards. Published as the international standard ISO/IEC 1539:1991 by the International Organization for Standardization (ISO) in December 1991, it succeeded the Fortran 77 standard (ISO/IEC 1539:1978) and introduced features to address the evolving needs of computational science.[8] This revision was developed by the ISO/IEC JTC1/SC22/WG5 committee over more than a decade, incorporating input from the global Fortran community to enhance expressiveness, portability, and efficiency.[9] Among its key innovations, Fortran 90 introduced modules to promote better code organization, data hiding, and reusability by allowing related procedures and data to be encapsulated in named units that could be used across programs. Dynamic memory allocation was enabled through allocatable arrays, which permit arrays to be sized and allocated at runtime using theALLOCATE and DEALLOCATE statements, eliminating the need for fixed-size declarations common in earlier versions. Support for recursive subroutines and functions allowed procedures to call themselves, facilitating algorithms like tree traversals or divide-and-conquer methods. Additionally, array operations provided whole-array arithmetic, intrinsic functions for array manipulation (e.g., SUM, MAXVAL), and array sections, enabling concise vectorized computations that improve readability and performance on vector processors.[10][11]
The language also advanced syntax flexibility with the introduction of free-form source code, where statements are not bound to specific columns (unlike the fixed-form of Fortran 77), allowing continuations with & and improving code maintainability. DO loops gained support for non-integer control variables, such as real numbers, though integer indices remain preferred for precision. Derived types (structures) enabled user-defined composite data types, combining scalars, arrays, and other derived types into a single entity. For instance, a simple derived type for a 2D point might be defined and used as follows:
This construct supports operations on components and is foundational for modeling complex entities in simulations.[12][13] Fortran 90's adoption transformed high-performance computing, becoming the de facto standard for numerical simulations in fields like fluid dynamics, climate modeling, and quantum chemistry due to its optimized array handling and interoperability with libraries. Source files written in Fortran 90 conventionally use thefortrantype :: point real :: x, y end type point type(point) :: origin origin%x = 0.0 origin%y = 0.0type :: point real :: x, y end type point type(point) :: origin origin%x = 0.0 origin%y = 0.0
.f90 extension to indicate the standard and enable compiler-specific processing.[13] Its legacy endures in supercomputing environments, where it underpins legacy codes and new developments. As the foundation for future evolution, Fortran 90 informed the Fortran 95 standard (ISO/IEC 1539-1:1997), which added features like the FORALL construct and pure procedures while ensuring full backward compatibility with Fortran 77 and Fortran 90 code.[14] This compatibility has allowed seamless migration of decades-old applications to modern hardware and compilers.[15]
F90 (ICD-10 code)
In the International Classification of Diseases, 10th Revision (ICD-10), developed by the World Health Organization (WHO), Chapter V (F01-F99) encompasses mental and behavioral disorders, with the F90 category specifically designating hyperkinetic disorders, which correspond to attention-deficit hyperactivity disorder (ADHD) in clinical practice.[16] These disorders are defined by early onset—typically before age 6 or 7—marked by pervasive overactivity, inattention, impulsiveness, and impaired self-control that are inconsistent with the individual's developmental level and occur across multiple settings, such as home and school.[16] The condition requires significant impairment in social, academic, or occupational functioning and is not attributable to other causes like organic brain disease, pervasive developmental disorders, or substance use.[16] The ICD-10 outlines specific subcodes under F90 to differentiate presentations:- F90.0: Disturbance of activity and attention, the core form involving inattention and overactivity without prominent conduct issues, often accompanied by learning difficulties.
- F90.1: Hyperkinetic conduct disorder, where hyperkinetic symptoms co-occur with significant aggressive or rule-breaking behaviors.
- F90.2: Other hyperkinetic disorders, for cases not fitting the above but meeting general criteria.
- F90.8: Other specified hyperkinetic disorders.
- F90.9: Hyperkinetic disorder, unspecified, used when details are incomplete.[16][17]
Military
F90 assault rifle
The F90 assault rifle, developed by Thales Australia (now Lithgow Arms), represents an evolutionary upgrade to the F88 Austeyr, a licensed variant of the Steyr AUG bullpup rifle previously in service with the Australian Defence Force (ADF).[21][22] Development began in the early 2010s under the ADF's Land 125 Phase 3C program to enhance ergonomics, modularity, and reliability for modern combat needs, with the rifle first publicly displayed at Eurosatory 2012.[21][22] Low-rate initial production commenced in 2014, followed by a A$100 million contract in August 2015 for 30,000 units, and an additional order in July 2020 for 8,500 more rifles.[21][23] This led to its adoption by the ADF in 2016 under the designation Enhanced F88 (EF88) for domestic service, while the F90 name is retained for export versions.[21][24] The F90 maintains the compact bullpup configuration of its predecessor, chambered in 5.56×45mm NATO ammunition, with a cold hammer-forged, chrome-lined barrel typically measuring 508 mm for the standard model to optimize muzzle velocity and accuracy.[25][22] Constructed primarily from impact-resistant polymer with a modular receiver, it features an integrated Picatinny rail system along the top for optics and accessories, ambidextrous controls including a folding cocking handle and enlarged trigger guard, and compatibility with suppressors and underbarrel grenade launchers.[21][25] Key specifications include:| Feature | Specification |
|---|---|
| Weight (unloaded, standard barrel) | 3.39 kg |
| Overall length (standard barrel) | 802 mm |
| Barrel length | 508 mm (standard), 407 mm (carbine), 360 mm (CQB) |
| Effective range | 500 m |
| Cyclic rate of fire | 740–850 rounds per minute |
| Magazine capacity | 30 rounds (polymer, translucent) |