Technology and the built world

Membrane emulsification

Membrane emulsification is a technique that makes uniform emulsions by forcing a liquid through tiny membrane pores, so droplet size is set by pore size.

Membrane filtration

Membrane filtration is a separation process in which a semipermeable membrane, driven by a pressure difference, retains particles, solutes, or microorganisms while passing water or another fluid.

Membrane fouling

Membrane fouling is the deposition of particles, colloids, macromolecules, and microorganisms on a membrane during filtration, cutting flux and raising pressure in processes like reverse osmosis.

Membrane humidifier

A membrane humidifier is a heat and mass exchanger that humidifies the inlet air of proton exchange membrane fuel cells without moving parts or external water.

Membrane reforming is a hydrogen production technique that combines steam reforming of hydrocarbons with in situ hydrogen separation through a palladium membrane, allowing conversion at lower temperatures.

Membrane theory (structures)

Membrane theory is a simplified structural theory for thin shells in which loads are carried entirely by in-plane forces, with no bending moments; it is the standard first analysis for domes and pressure vessel heads.

Membrane-type LNG containment

Membrane-type LNG containment is a cryogenic cargo system in which thin metallic membranes supported by a ship's inner hull hold LNG at about -163 °C and atmospheric pressure.

Memcached

Memcached is a free and open source distributed memory object caching system that speeds up dynamic web applications by reducing database load, created by Brad Fitzpatrick for LiveJournal in 2003.

Memetic algorithm

A memetic algorithm is a population-based metaheuristic combining an evolutionary framework with local-search operators that refine individual solutions, introduced by Pablo Moscato in 1989 for hard optimization problems.

Memex

The memex is a hypothetical electromechanical personal information machine described by Vannevar Bush in his 1945 essay "As We May Think", never built, and regarded as the origin of hypertext.

MemGPT

MemGPT, introduced in a 2023 UC Berkeley paper, is an agent design in which a large language model pages information between its fixed context window and external storage.

Memoization

Memoization is an optimization technique in which a function stores results of previous calls and returns them instead of recomputing, as proposed by Donald Michie in 1967.

Memorization of training data in language models

Memorization of training data in language models is the phenomenon where a large language model reproduces text from its training corpus, sometimes verbatim, raising privacy, copyright, and benchmark-contamination concerns.

Memory address

A memory address is an integer identifying a byte position in a processor's address space, and the MMU translates virtual addresses to physical ones through page tables.

Memory bandwidth

Memory bandwidth is the rate at which a computer's memory can transfer data to or from a processor, measured in bytes per second and distinct from latency.

Memory barrier

A memory barrier, also called a memory fence, is a CPU instruction or compiler directive that constrains how load and store operations become visible to other cores and devices.

Memory card

A memory card, or flash memory card, is removable NAND flash storage used in cameras, phones, drones, and game consoles, dominated by the SD card family.

Memory controller

A memory controller is the digital logic mediating between a processor's last-level cache and DRAM chips, converting read and write requests into command sequences and refreshes; since Intel's 2008 Nehalem it sits on the processor die.

Memory disambiguation

Memory disambiguation is the problem of determining whether a load and a store refer to the same address, so processors can execute loads speculatively and compilers can reorder memory operations.

Memory hierarchy

The memory hierarchy, also called the storage hierarchy, is the layered arrangement of computer storage from fast registers and caches to slow main memory and disk.

Memory leak

A memory leak is memory a program has allocated but can no longer release or use, so consumption grows until performance degrades or the program fails.

Memory management

Memory management, also called dynamic storage allocation, is how operating systems and language runtimes allocate memory, translate program addresses, and reclaim memory through paging, manual allocation, or garbage collection.

Memory management unit

The memory management unit (MMU), or paged memory management unit, is a hardware component that translates virtual addresses into physical ones, enabling paged virtual memory and raising page faults.

Memory module

A memory module, also called a memory board, is a printed circuit board carrying DRAM chips that plugs into a motherboard to provide a computer's RAM.

Memory network (machine learning)

A memory network, or memory-augmented neural network, is a neural network architecture with an external memory the model reads and writes, introduced for question answering in 2014.

Memory ordering

Memory ordering is the set of rules, called a memory model, that determines the order in which loads and stores appear to execute in a multiprocessor.

Memory overcommitment

Memory overcommitment is an operating system and hypervisor policy that promises more virtual memory than physical RAM backs, shifting failures to first use by the OOM killer.

Memory protection unit

A memory protection unit (MPU) is a programmable hardware block in a processor that defines memory access permissions for physical address ranges, without virtual address translation.

Memory rank

A memory rank is a group of DRAM chips on a memory module accessed together to supply the full 64-bit width of the memory data bus.