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Process (engineering)
In engineering, a process is a series of interrelated tasks that, together, transform inputs into a given output.ANSI/EIA-632-1998 Processes for Engineering a System, Appendix A These tasks may be carried out by people, nature or machines using various resources; an engineering process must be considered in the context of the agents carrying out the tasks and the resource attributes involved. Systems engineering normative documents and those related to Maturity Models are typically based on processes, for example, systems engineering processes of the EIA-632 and processes involved in the Capability Maturity Model Integration (CMMI) institutionalization and improvement approach. Constraints imposed on the tasks and resources required to implement them are essential for executing the tasks mentioned. Semiconductor industry Semiconductor process engineers face the unique challenge of transforming raw materials into high-tech devices. Common semiconductor devices include Integrated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engineering
Engineering is the practice of using natural science, mathematics, and the engineering design process to Problem solving#Engineering, solve problems within technology, increase efficiency and productivity, and improve Systems engineering, systems. Modern engineering comprises many subfields which include designing and improving infrastructure, machinery, vehicles, electronics, Materials engineering, materials, and energy systems. The Academic discipline, discipline of engineering encompasses a broad range of more Academic specialization, specialized fields of engineering, each with a more specific emphasis for applications of applied mathematics, mathematics and applied science, science. See glossary of engineering. The word '':wikt:engineering, engineering'' is derived from the Latin . Definition The American Engineers' Council for Professional Development (the predecessor of the Accreditation Board for Engineering and Technology aka ABET) has defined "engineering" as: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopant
A dopant (also called a doping agent) is a small amount of a substance added to a material to alter its physical properties, such as electrical or optics, optical properties. The amount of dopant is typically very low compared to the material being doped. When doped into crystalline substances, the dopant's atoms get incorporated into the crystal lattice of the substance. The crystalline materials are frequently either crystals of a semiconductor such as silicon and germanium for use in solid-state electronics, or transparency and translucency, transparent crystals for use in the production of various laser types; however, in some cases of the latter, noncrystalline substances such as glass can also be doped with impurities. In solid-state electronics using the proper types and amounts of dopants in semiconductors is what produces the p-type semiconductors and n-type semiconductors that are essential for making transistors and diodes. Transparent crystals Lasing media The p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mnemonic
A mnemonic device ( ), memory trick or memory device is any learning technique that aids information retention or retrieval in the human memory, often by associating the information with something that is easier to remember. It makes use of elaborative encoding, retrieval cues and imagery as specific tools to encode information in a way that allows for efficient storage and retrieval. It aids original information in becoming associated with something more accessible or meaningful—which in turn provides better retention of the information. Commonly encountered mnemonics are often used for lists and in auditory system, auditory form such as Acrostic, short poems, acronyms, initialisms or memorable phrases. They can also be used for other types of information and in visual or kinesthetic forms. Their use is based on the observation that the human mind more easily remembers spatial, personal, surprising, physical, sexual, humorous and otherwise "relatable" information rather tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Process Simulation
Process simulation is used for the design, development, analysis, and optimization of technical process of simulation of processes such as: chemical plants, chemical processes, environmental systems, power stations, complex manufacturing operations, biological processes, and similar technical functions. Main principle Process simulation is a model-based representation of chemical, physical, biological, and other technical processes and unit operations in software. Basic prerequisites for the model are chemical and physical properties of pure components and mixtures, of reactions, and of mathematical models which, in combination, allow the calculation of process properties by the software. Process simulation software describes processes in flow diagrams where unit operations are positioned and connected by product or educt streams. The software solves the mass and energy balance to find a stable operating point on specified parameters. The goal of a process simulatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piping And Instrumentation Diagram
A Piping and Instrumentation Diagram (P&ID) is a detailed diagram in the process industry which shows process equipment together with the instrumentation and control devices. It is also called as mechanical flow diagram (MFD). Superordinate to the P&ID is the process flow diagram (PFD) which indicates the more general flow of plant processes and the relationship between major equipment of a plant facility. Contents and function A piping and instrumentation diagram (P&ID) is defined as follows: # A diagram which shows the interconnection of process equipment and the instrumentation used to control the process. In the process industry, a Symbolic language (engineering), standard set of symbols is used to prepare drawings of processes. The instrument symbols used in these drawings are generally based on International Society of Automation (ISA) Standard S5.1 # The primary schematic drawing used for laying out a process control installation. They usually contain the following inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Process Flow Diagram
A process flow diagram (PFD) is a diagram commonly used in chemical and process engineering to indicate the general flow of plant processes and equipment. The PFD displays the relationship between ''major'' equipment of a plant facility and does not show minor details such as piping details and designations. Another commonly used term for a PFD is ''process'' ''flowsheet''. It is the key document in process design. Typical content of a process flow diagram Typically, process flow diagrams of a single unit process include the following: * Process piping * Major equipment items *Connections with other systems * Major bypass and recirculation (recycle) streams * Operational data (temperature, pressure, mass flow rate, density, etc.), often by stream references to a mass balance * Process stream names Process flow diagrams generally do not include: * Pipe classes or piping line numbers * Instrumentation details * Minor bypass lines * Instrumentation * Controllers like Level Con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Engineering
Chemical engineering is an engineering field which deals with the study of the operation and design of chemical plants as well as methods of improving production. Chemical engineers develop economical commercial processes to convert raw materials into useful products. Chemical engineering uses principles of chemistry, physics, mathematics, biology, and economics to efficiently use, produce, design, transport and transform energy and materials. The work of chemical engineers can range from the utilization of nanotechnology and nanomaterials in the laboratory to large-scale industrial processes that convert chemicals, raw materials, living cells, microorganisms, and energy into useful forms and products. Chemical engineers are involved in many aspects of plant design and operation, including safety and hazard assessments, process engineering, process design and analysis, modeling and simulation, modeling, control engineering, chemical reaction engineering, nuclear engineering, biologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unit Operation
In chemical engineering and related fields, a unit operation is a basic step in a process. Unit operations involve a physical change or chemical transformation such as separation, crystallization, evaporation, filtration, polymerization, isomerization, and other reactions. For example, in milk processing, the following unit operations are involved: homogenization, pasteurization, and packaging. These unit operations are connected to create the overall process. A process may require many unit operations to obtain the desired product from the starting materials, or feedstocks. History Historically, the different chemical industries were regarded as different industrial processes and with different principles. Arthur Dehon Little developed the concept of "unit operations" to explain industrial chemistry processes in 1916. In 1923, William H. Walker, Warren K. Lewis and William H. McAdams wrote the book ''The Principles of Chemical Engineering'' and explained that the variety of c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the redox, reduction of cations of that metal by means of a direct current, direct electric current. The part to be coated acts as the cathode (negative electrode) of an electrolytic cell; the electrolyte is a solution (chemistry), solution of a salt (chemistry), salt whose cation is the metal to be coated, and the anode (positive electrode) is usually either a block of that metal, or of some inert electrical conductor, conductive material. The current is provided by an external power supply. Electroplating is widely used in industry and decorative arts to improve the surface qualities of objects—such as resistance to abrasion (mechanical), abrasion and corrosion, lubrication, lubricity, reflectivity, electrical conductivity, or appearance. It is used to build up thickness on undersized or worn-out parts and to manufacture metal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ion Implantation
Ion implantation is a low-temperature process by which ions of one element are accelerated into a solid target, thereby changing the target's physical, chemical, or electrical properties. Ion implantation is used in semiconductor device fabrication and in metal finishing, as well as in materials science research. The ions can alter the elemental composition of the target (if the ions differ in composition from the target) if they stop and remain in the target. Ion implantation also causes chemical and physical changes when the ions impinge on the target at high energy. The crystal structure of the target can be damaged or even destroyed by the energetic collision cascades, and ions of sufficiently high energy (tens of MeV) can cause nuclear transmutation. General principle Ion implantation equipment typically consists of an ion source, where ions of the desired element are produced, an accelerator, where the ions are electrostatically accelerated to a high energy or usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systems Engineering
Systems engineering is an interdisciplinary field of engineering and engineering management that focuses on how to design, integrate, and manage complex systems over their Enterprise life cycle, life cycles. At its core, systems engineering utilizes systems thinking principles to organize this body of knowledge. The individual outcome of such efforts, an engineered system, can be defined as a combination of components that work in synergy to collectively perform a useful Function (engineering), function. Issues such as requirements engineering, Reliability engineering, reliability, logistics, coordination of different teams, testing and evaluation, maintainability, and many other Discipline (academia), disciplines, aka List of system quality attributes, "ilities", necessary for successful system design, development, implementation, and ultimate decommission become more difficult when dealing with large or complex projects. Systems engineering deals with work processes, optimizat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Etching (microfabrication)
Etching is used in microfabrication to chemically remove layers from the surface of a wafer (electronics), wafer during manufacturing. Etching is a critically important process module in fabrication, and every wafer undergoes many etching steps before it is complete. For many etch steps, part of the wafer is protected from the etchant by a "masking" material which resists etching. In some cases, the masking material is a photoresist which has been patterned using photolithography. Other situations require a more durable mask, such as silicon nitride. Etching media and technology The two fundamental types of etchants are liquid-phase ("wet") and plasma (physics), plasma-phase ("dry"). Each of these exists in several varieties. Wet etching The first etching processes used liquid-phase ("wet") etchants. This process is now largely outdated but was used up until the late 1980s when it was superseded by dry plasma etching. The wafer can be immersed in a bath of etchant, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
