Glossary of technical terms for the use of metallurgical engineers Terms starting with alphabet ‘Q’
Glossary of technical terms for the use of metallurgical engineers
Terms starting with alphabet ‘Q’
Q-BOP process – It is also known as OBM process. Oxygen in this process is injected into the bath through tuyeres inserted in the bottom of the furnace. Each tuyere is made from two concentric tubes forming an inner nozzle and an outer annulus. Oxygen and powdered lime are injected through the central portion of the tuyeres, while a hydro-carbon gas, typically natural gas or propane, is injected through the annular section between the two concentric pipes. The endothermic decomposition of the hydro-carbon gas and the sensible heat needed to bring the products of the decomposition up to steelmaking temperatures result in localized cooling at the tip of the tuyere. The localized cooling is enough to chill the liquid metal and form a porous mushroom on the tip of the tuyere and part of the surrounding refractory. This mushroom reduces the burn back rate of the tuyere, and the wear of the surrounding refractory. The injected lime provides additional cooling to the tuyere, and results in better slag refining characteristics. Top lances in Q-BOP furnaces have also been adopted, mainly for the purposes of increasing the post-combustion of the off-gases within the furnace, and to control the build-up of slag and metal in the furnace cone area. Top lances used in Q-BOP furnaces are normally stationary, since they are not used for refining purposes. Tuyeres, located in the upper cone area of furnaces with a heat size larger than around 150 tons have also been used, but typically result in higher refractory wear. For this reason, their application has been limited to shops which need increased scrap melting capabilities (resulting in shorter lining lives), and with a heat size smaller than 150 tons.
Quadrature booster – It is a phase shifting transformer which can inject voltages that are time delayed with respect to the input voltage.
Quadrivariant equilibrium – It is a stable state among several conjugate phases equal to two less than the number of components, i.e., having four degrees of freedom.
Quadrupole mass spectrometer – It is also called quadrupole mass analyzer. It is a type of mass analyzer. As the name implies, it consists of four cylindrical rods, set parallel to each other. In a quadrupole mass spectrometer (QMS) the quadrupole is the mass analyzer which is the component of the instrument responsible for selecting sample ions based on their mass-to-charge ratio. Ions are separated in a quadrupole based on the stability of their trajectories in the oscillating electric fields which are applied to the rods. The quadrupole consists of four parallel metal rods. Each opposing rod pair is connected together electrically, and a radio frequency (RF) voltage with a direct current offset voltage is applied between one pair of rods and the other. Ions travel down the quadrupole between the rods. Only ions of a certain mass-to-charge ratio will reach the detector for a given ratio of voltages: other ions have unstable trajectories and will collide with the rods. This permits selection of an ion with a particular metal to charge or allows the operator to scan for a range of metal to charge values by continuously varying the applied voltage.
Qualification – It ensures fitness for intended purpose. It is the process of verifying that a piece of equipment or a particular item is fit for its intended purpose. It focuses on ensuring that all aspects of the equipment or facility meet regulatory and operational requirements. It ensures that the equipment, instruments, and software used in the plant are functioning properly and capable of producing consistent results. This process is directly linked to the equipment, rather than the overall process itself.
Qualification process – It is a comprehensive process applied to different elements within a manufacturing plant. It encompasses (i) ensures the correct functioning and performance of manufacturing equipment, (ii) validates the reliability of support systems integral to the manufacturing process, (iii) verifies the accuracy and precision of measurement instruments used in production, and (iv) qualifies utility systems such as water, air, and power to meet specified requirements.
Qualification trials – These trials constitute the testing needed for a new process adopted to make certain grades of steel with exacting end uses. In order for the process to become qualified, the steel made by the process must be tested.
Qualified expert – Qualified expert is an independent person with education, training, and relevant professional experience in a discipline pertinent to a Project, acting in compliance with the professional standards of competence and ethics established by his / her professional organization. This person is responsible for the standards and methodologies used for collecting, analyzing, and verifying information used in qualified assessments.
Qualitative analysis – It is an analysis in which some or all of the components of a sample are identified.
Qualitative measurement – Qualitative measurement is descriptive and cannot be expressed with a numeric value. It is based on qualitative variables which are described based on their observable features. This means that it cannot be measured with a scale, ruler, or numeric measurement. It cannot be measured in a traditional way. Qualitative measurement is taken by categorizing traits into identifiable descriptive terms. By this standard, a trait can be compared to a definition of categories to determine its measurement.
Qualitative scanning electron microscopy (SEM) examination – It is a descriptive observation method which is being used to study the structure, composition, and orientation of materials.
Qualitative study – It involves collecting and analyzing non-numerical data (e.g., text, video, or audio) to understand concepts, opinions, or experiences.
Qualitative variable – In statistics, it is one which falls into descriptive categories, things which are not measured. Colour, taste, smell, style, mood, and satisfaction are examples of qualitative variables. These variables are not measured with numbers but rather describe the quality of something. For example, height (2.1 meters) is not a qualitative variable but size (a person is tall) is. Qualitative variables are also called categorical variables.
Quality – It is the totality of features and characteristics of a product or service that bear on its ability to satisfy a given need (fitness-for-use concept of quality). It is the degree of excellence of a product or service (comparative concept). It is frequently determined subjectively by comparison against an ideal standard or against similar products or services available from other sources. It is a quantitative evaluation of the features and characteristics of a product or service (quantitative concept). Quality can be variously thought of as (i) conformance to the specification, (ii) fitness for purpose, (iii) meeting customers’ requirements, (iv) doing things right first time, and (v) the features and characteristics of a product which bear upon its ability to satisfy a stated need.
Quality advantage – It refers to a competitive edge or superior position gained by consistently delivering high-quality products or services, leading to increased customer satisfaction and potentially higher profits.
Quality approach to management – It describes how quality is to be managed in the organization. This includes the specific processes, procedures, techniques, standards, and responsibilities to be applied. A template is normally provided by the organization which needs only minor changes during the implementation of the quality approach. This document is created at the initiation stage with the other approach documents and becomes part of the plant quality documentation. The quality approach to management also defines the different responsibilities for achieving the required quality levels, during the implementation of the quality approach. The quality approach to management answers several questions which include (i) which quality management system to use, i.e., from customer, supplier, or a mixture, (ii) what standards are to be used, (iii) what tools and techniques are to be used, (iv) how quality assurance is to be carried out, (v) who is responsible for documenting customer’s quality expectations and acceptance criteria, (vi) who is responsible for quality assurance, approving the quality approach to management, confirming acceptance of the organizational products, and (vii) records needed and timing of quality activities.
Quality assurance (QA) – It is the term used in both manufacturing and service industries to describe the systematic efforts taken to assure that the product(s) delivered to customer(s) meet with the contractual and other agreed upon performance, design, reliability, and maintainability expectations of that customer. The core purpose of quality assurance is to prevent mistakes and defects in the development and production of both manufactured products and delivered services. It is the process which ensures that standards are met during manufacturing of a product.
Quality audit – It is the process of systematic examination of a quality system carried out by an internal or external quality auditor or an audit team. It is an important part of an organization’s quality management system and is a key element in the ISO (International Organization for Standardization) quality system standard, ISO 9001.
Quality by design – It is a systematic approach to development which begins with predefined objectives and emphasizes product and process understanding and process control, based on sound science and quality risk management.
Quality characteristics – Quality characteristic refers to the attributes, measures, and methods attached to a process, product, or service that are used to define quality or acceptance criteria. These characteristics are defined based on how stakeholders and beneficiaries prioritize different attributes such as functionality, performance, reliability, relevance, timeliness, suitability, completeness, and consistency. These characteristics fall into two broad classes (i) variables, and (ii) attributes. Characteristics which are measurable and are expressed on a numerical scale are called variables. Examples of variables are the density of a liquid in grams per cubic centimeter and the processing speed of a computer. A quality characteristic is said to be an attribute if it is classified as either conforming or non-conforming to a stipulated specification. A quality characteristic which cannot be measured on a numerical scale is expressed as an attribute. For example, the colour of a product is either acceptable or is not. However, there are some variables which are treated as attributes because it is simpler to measure them this way or because it is difficult to obtain data on them. Examples in this category are several.
Quality circle – Quality circle considers employees as the greatest assets of the organization. This is since through the employees all other resources are converted into products. It is a people building concept which is based on the proposition that employees doing their jobs are experts in their field of activity and hence are in a better position to identify, analyze, and resolve the work-related issues through the innovative and unique ideas. In reality, it is a practical application of McGregor’s theory ‘Y’ which says that people enjoy and take pride in their work if they are given the right environment and the decision-making power. This in turn leads to enrichment of their work life. In simplest term, quality circle causes a situation where management backs and gives the employees the suitable training and the time to help solve the work-related problems. As the employees resolve problems, management gains a new respect for their capabilities, and as their suggestions are acted upon, the employees can see their influence on the work process, which gives a real basis for job satisfaction and new attitudes.
Quality control – It is a process for maintaining standards. Standards are maintained through a process of selection, measurement and correction of work, so that only those products or services emerge from the process which meets the standards. In simple terms, quality control prevents undesirable changes being present in the quality of the product or service being supplied. Quality control can be applied to particular products, to processes which produce the products, or to the output of the whole organization by measuring the overall quality performance of the organization. Quality control is a process by which entities review the quality of all factors involved in the production. Quality control is a part of quality management focused on fulfilling quality requirements. This approach places emphasis on three aspects namely (i) elements such as controls, job management, defined and well managed processes, performance and integrity criteria, and identification of records, (ii) competence, such as knowledge, skills, experience, and qualifications, and (iii) soft elements, such as personnel, integrity, confidence, organizational culture, motivation, team spirit, and quality relationships. Inspection is a major component of quality control, where physical product is examined visually (or the end results of a service are analyzed). Product inspectors are to be provided with lists and descriptions of unacceptable product defects such as cracks or surface blemishes etc.
Quality control tools and techniques – Majority of the tools and techniques to control quality are statistical techniques. Manufacturing organizations applies different quality control techniques to improve the quality of the process by reducing its variability. A range of techniques are available to control product or process quality. These include seven statistical process control (SPC) tools consisting of (i) cause-and-effect diagram (also called Ishikawa diagram or fishbone diagram), (ii) check sheet, (iii) control chart, (iv) histogram, (v) pareto chart, (vi) scatter diagram, and (vii) stratification. Besides SPC tools, other techniques which are available to control product or process quality are (i) acceptance sampling, (ii) quality function deployment (QFD), (iii) failure mode and effects analysis (FMEA), (iv) six sigma, and design of experiments (DoE).
Quality cost – It has three components namely defect prevention cost, testing cost, and defect cost. Defect cost can be in-house or external. Quality cost is also the cost of doing an activity and achieving the targeted results of the activity. It consists of two components namely necessary costs and avoidable costs. Necessary costs are needed to achieve and sustain a defined objective or standard of work. These are those costs which are needed to carry out an activity efficiently and to achieve and sustain a defined standard of work. These costs are required to be incurred. Any action to cut or reduce these costs has an adverse effect on the organizational performance. Necessary costs include prevention and inspection costs. Avoidable costs are normally incurred whenever wrong things are being done or things are being done in a wrong way in the organization. Organizational management is required to identify where such things are happening in the organization and take the required action to eliminate these things. Avoidable costs include some part of inspection costs and failure costs.
Quality design – It has strong engineering orientation and focus primary attention on the engineering design process, particularly the projection of a three-stage design process model of system design, parameter design, and tolerance design.
Quality factor – In a resonant circuit, it is the ratio of stored energy to energy dissipated on each cycle of oscillation.
Quality function deployment (QFD) – It is a focused methodology for carefully listening to the voice of the customer and then effectively responding to those needs and expectations. In quality function deployment, quality is a measure of customer satisfaction with a product or a service. Quality function deployment is a structured method which uses the seven management and planning tools to identify and prioritize customers’ expectations quickly and effectively. Beginning with the initial matrix, normally termed the House of Quality, the quality function deployment methodology focuses on the most important product or service attributes or qualities. These are composed of customer wows, wants, and musts. Once one has prioritized the attributes and qualities, quality function deployment deploys them to the appropriate organizational function for action. Hence, quality function deployment is the deployment of customer-driven qualities to the responsible functions of an organization.
Quality gap – It refers to the difference between a desired or expected level of quality and the actual level achieved. It can manifest in different areas, including customer service, and product development, highlighting areas where improvements are needed.
Quality index – It is a one-dimension synthetical information on quality, possibly calculated as a weighted mean of all available quality indicators.
Quality life-cycle management (QLM) – It is an organization-wide, cross-functional solution for ensuring product performance, reliability, and safety are aligned with the requirements set for them over the course of a product’s life. Quality life-cycle management is used to build quality, reliability, and risk planning into every part of the product lifecycle by aligning functional needs with product requirements, ensuring these requirements are met by specific characteristics, and tracking these characteristics systematically throughout development, testing, manufacture, fielded use, and service to ensure the product requirements are met at every lifecycle stage. It provides a formalized, systematic solution to manage all aspects of product quality, reliability, and risk using methods that are fully integrated into the product development life-cycle and highly visible to all personnel with a stake in product quality.
Quality loss function – It is an approach to evaluating quality in which quality is measured by the money loss because of some quality characteristic deviating from the target value. Mathematically, the loss function is a quadratic function of the deviation from the target value.
Quality management – It is the process of overseeing the activities of an organization to maintain a high standard of quality. It involves setting quality policies, creating plans, and implementing quality assurance and control. It ensures that an organization, product, or service consistently functions as intended. It has four main components namely quality planning, quality assurance, quality control, and quality improvement. Customers recognize that quality is an important attribute when choosing and purchasing products and services. Suppliers can recognize that quality is an important differentiator of their offerings and endeavor to compete on the quality of their products and the service they offer. Hence, quality management is focused both on product and service quality, as well as the means to achieve them both.
Quality management standards – These consist of ISO 9000 series of standards. This series consists of a family of quality management systems (QMS) standards created by the International Organization for Standardization (ISO). There are 26 standards under this family. The ISO 9000 quality management system standards are not specific to products or services, but apply to the processes which create them. The standards are generic in nature so that they can be used by manufacturing and service industries anywhere in the world. The ISO 9000 family of quality management standards and guidelines has earned a global recognition as a basis for establishing effective and efficient quality management system. In developing quality management system in the organization, the fundamental concepts and principles given in ISO 9000 can provide valuable guidance.
Quality management system – It is a dynamic system which evolves over a period of time through improvement. It is a management technique used to communicate to the employees what is needed to produce the desired quality of products and services and to influence employees’ actions to complete tasks according to the quality specifications. It is a structured collection of written policies, processes, documented procedures and records and their associated responsibilities. The purpose of a quality management system includes (i) to establish a vision for the employees, (ii) to set standards for the employees, (iii) to build motivation within the organization, (iv) to sets goals for the employees, (v) to help fight the resistance to change within organization, and (vi) to help direct the corporate culture. Quality management system is necessary to determine activities which already exist and their suitability within the context of the organization. It provides opportunities (i) to review and help the organization in becoming more competitive, (ii) to improve communication within the organization, (ii) to structure approaches in correcting defects, mistakes, or deviations, (iii) to take process of corrective and preventing actions for ensuring higher risk problems and issues are promptly and properly dealt with, (iv) to ensure that corrective and preventing actions are consistently undertaken based on priority and risk, and (v) to improve complaint handling which results into better customer satisfaction. Quality management system enables the organization to run more efficiently and profitably. It provides a way to organize people, resources, and processes to achieve organizational goals, regardless of the size of the organization.
Quality management system principles – Quality management system is based on eight quality management principles. These principles are used as a guide for the organization to improve its performance. These eight principles provide the basis for the performance improvement and namely are (i) customer focus, (ii) leadership, (iii) involvement of employees, (iv) process approach, (v) system approach to management, (vi) continual improvement, (vii) factual approach to decision making, and (viii) mutually beneficial supplier relationship.
Quality of conformance – It is a quality management term which measures how well a product or service meets its specifications and design requirements. It is a key aspect of quality which is focused on the operations side of things. It refers to the degree to which the design and operating characteristics of the product meet established standards or specifications. In simpler terms, it is about how well a product or service aligns with its intended design or requirement specifications.
Quality of life (QOL) – It is defined by the World Health Organization as ‘people perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns’. Standard indicators of the quality of life include wealth, employment, the environment, physical and mental health, education, recreation and leisure time, social belonging, religious beliefs, safety, security, and freedom.
Quality of steam – It is the representation of dryness fraction in percentage.
Quality planning – It is the ability to identify all functional needs of the product ahead of time and incorporate this information into each stage in the product development life-cycle which is key to ensuring product quality. With all functional requirements of the product identified from every potential source (including customer feedback) all product characteristics which are necessary to support these requirements can be identified and tracked across product development for ensuring that they are being fulfilled.
Quality policy – It is a brief statement which aligns with the organization’s purpose and strategic direction, and provides a framework for quality objectives. Quality policy is a formal document which defines the organization’s commitment to quality standards and its vision. It guides employees, meets stakeholder expectations, and ensures consistent product and service delivery. Its purpose includes (i) to define the organization’s vision and commitment to quality standards, (ii) to guide employees, (iii) to meet stakeholder expectations, and (iv) to ensure consistent product and service delivery.
Quality, product – Product quality refers to the characteristics, features, and attributes of a product which determine its ability to meet customer expectations and perform its intended function. Quality encompasses different aspects, such as reliability, durability, performance, safety, and conformance to specifications.
Quality specification – It is a set of conditions and requirements, of specific and limited application, that provide a detailed description of the procedure, process, material, product, or service for use primarily in procurement and manufacturing (standards can be referenced or included in a specification). Quality specification is a document which defines the requirements for a product or service. It can also refer to the process of establishing quality standards for a product or service. Quality specifications define the characteristics, measurements, and attributes required for a product to be acceptable to consumers and regulatory bodies.
Quality standard – It is a prescribed set of conditions and requirements, of general or broad application, established by authority or agreement, to be satisfied by a material, product, process, procedure, convention, test method, and / or the physical, functional, performance or conformance characteristic thereof, and a physical embodiment of a unit of measurement (for example, an object such as the standard kilogram or an apparatus such as the cesium beam clock). Acceptable bounds on individual quality characteristics (e.g., +/- 0.1 millimeters for the inside diameter) are normally known as specification limits, whereas the document which addresses the requirements of all the quality characteristics is labeled as the standard. Standards are the documents which provide requirements, specifications, guidelines, or characteristics which can be used consistently to ensure that materials, products, processes, and services are fit for their purpose. The standards provide organizations with the shared vision, understanding, procedures, and vocabulary needed to meet the expectations of their stakeholders. Since standards present precise descriptions and terminology, they offer an objective and authoritative basis for organizations and consumers to communicate and conduct business. Quality standards are also sets of good management practices to foster consistent production and product condition. These standards are good management practices, methods, systems, requirements and specifications established by industry advisory groups to help manufacturers achieve and demonstrate consistent production and product quality. Some quality standards are applicable to a broad spectrum of manufacturing and service organizations, while others are industry specific.
Quantification – It is the act of counting and measuring which maps human sense, observations, and experiences into quantities. Quantification in this sense is fundamental to the scientific method.
Quantitative analysis – It is a measurement in which the quantity of one or more components of a sample is determined. It is the determination of the absolute or relative abundance (frequently expressed as a concentration) of one, several or all particular substances present in a sample, it relates to the determination of percentage of constituents in any given sample.
Quantitative electronic microscopy – It consists of quantitative microscopy using scanning electron microscopy-based automatic measurement methods and data-processing techniques which provide broad ranges of applications. It is very popular in the mining industry. These systems determine the quantities and micro-textures of the ore-samples and metallurgical products to guide process development and troubleshoot processing problems.
Quantitative evaluation – It refers to the systematic assessment of data using numerical measurements and statistical methods to determine the effectiveness, efficiency, and outcomes of a policy. This type of evaluation relies on objective metrics, such as surveys, tests, or existing datasets, to provide concrete evidence about the impact of policies and programs. By employing rigorous statistical analysis, quantitative evaluation helps policymakers understand what works, what does not, and informs future decisions.
Quantitative fractography – The principal objective of quantitative fractography is to express the characteristics of the features in the fracture surface in quantitative terms, such as the true area, length, size, spacing, orientation, and location, as well as distributions of these, as needed. The more prominent techniques for studying the fracture surface are based on the projected images (the picture obtained with the scanning electron microscope), stereoscopic viewing (using stereophotogrammetry), and sectioning (to generate profiles). The use of an automatic image analysis system with a digitizing tablet is extremely helpful, although manual methods offer efficient alternatives in some cases. Treatment of the basic data includes the choice of triangulation methods, stereo-photo-grammetry, or the angular distribution of elements along the fracture profile. Although these procedures allow the fracture surface area to be estimated, they are essentially only approximations of the complex and irregular fracture surfaces found in metals.
Quantitative image analysis – It refers to the use of computer algorithms to conduct accurate measurements, quantify stain intensity, and provide precise measurements.
Quantitative image analyzer – It is a computer-controlled device which uses television cameras for directly analysis within an optical microscope. Analysis of photomicrographs also can be accomplished. A quantitative image analyzer can be connected directly to a scanning electron microscope to control the scanning system. Particles can be counted according to their maximum horizontal chords, vertical chords, perimeters, or areas.
Quantitative measurements – These are those measurements which are counted and expressed by a numeric value. These are more accurate than qualitative measurements and can be compared or ranked. Quantitative measurements are measured to run statistical analyses. While analyses between all variable types can be made, the possibility of multiple statistical approaches to compare numeric values is an advantage of this variable type.
Quantitative metallography – It deals with the quantitative relationships between measurements made on the two-dimensional plane of polish and the magnitudes of the microstructural features in the three-dimensional metal or alloy. As material specifications become stricter and performance limits are narrowed, it becomes necessary to specify and control microstructure quantitatively. Quantitative metallography is determination of specific characteristics of a micro-structure by quantitative measurements on micrographs or metallographic images. Quantities so measured include volume concentration of phases, grain size, particle size, mean free path between like particles or secondary phases, and surface-area-to-volume ratio of microconstituents, particles, or grains.
Quantitative microscopy – It consists of the study of the microstructure of metals. It is used to quantify structural gradients, volume fraction, grain size and distribution, and other features of interest. It consists of methods to show how the different various features appear, how they are measured, and how the resulting data are converted into usable form.
Quantitative non-destructive evaluation (QNDE) – It provides techniques to assess deterioration of a material or a structure, and to detect and characterize discrete flaws. It plays, hence, an important role in the prevention of failure. Quantitative non-destructive evaluation technique is used in processing, manufacturing and for in-service inspection. Quantitative non-destructive evaluation is particularly important for the in-service inspection of high-cost and critical load-bearing structures whose failure can have tragic consequences.
Quantitative study – It is the process of collecting and analyzing numerical data to describe, predict, or control variables of interest. Quantitative methods emphasize objective measurements and the statistical, mathematical, or numerical analysis of data.
Quantitative variable – It measures a quantity. A quantitative variable can be discrete, where only certain values over a range are allowed. Quantitative variables can be measured and given a number value. Height, weight, diameter, angle measure are examples of quantitative variables.
Quantity – It is a property that can exist as a multitude or magnitude, which show discontinuity and continuity. Quantities can be compared in terms of ‘more’, ‘less’, or ‘equal’, or by assigning a numerical value multiple of a unit of measurement. Mass, time, distance, heat, and angle are among the familiar examples of quantitative properties. Quantity is among the basic classes of things along with quality, substance, change, and relation. Some quantities are such by their inner nature (as number), while others function as states (properties, dimensions, attributes) of things such as heavy and light, long and short, broad and narrow, small and great, or much and little. Along with analyzing its nature and classification, the issues of quantity involve such closely related topics as dimensionality, equality, proportion, the measurements of quantities, the units of measurements, number and numbering systems, the types of numbers and their relations to each other as numerical ratios.
Quantization – It is analog to digital conversion, changing a continuously varying analog signal to discrete digital numbers. In physics, quantization is the process of transitioning from classical mechanics to quantum mechanics. It is a way of constructing quantum mechanics from classical mechanics.
Quantum – It is the minimum quantity of any physical entity (physical property) involved in an interaction. Quantum is a discrete quantity of energy proportional in magnitude to the frequency of the radiation it represents.
Quantum mechanics – It is the study of how atoms, molecules, subatomic particles, etc. behave and are structured. It is the modern theory of matter, of electro-magnetic radiation, and of the interaction between matter and radiation. It is also, the mechanics of phenomena to which this theory can be applied. Quantum mechanics is also termed wave mechanics, generalizes and supersedes the older classical mechanics and Maxwell’s electromagnetic theory.
Quantum number – It is one of the quantities, normally discrete with integer or half-integer values, needed to characterize a quantum state of a physical system.
Quantum theory – It is a fundamental theory which describes the behaviour of nature at and below the scale of atoms. It is the foundation of all quantum physics, which includes quantum chemistry, quantum field theory, quantum technology, and quantum information science.
Quark – It is an elementary particle and a fundamental constituent of matter.
Quarry – It is a type of open-pit mine in which dimension stone, rock, construction aggregate, sand, gravel, or slate etc. is excavated from the ground. The operation of quarries is regulated in some jurisdictions to manage their safety risks and reduce their environmental impact.
Quarter buckle – It is a rare defect where the steel grains are elongated in the quarter regions (the portion of the strip between the centre and the edge). This is normally because of the use of excessive roll bending force since the bending force may not compensate for the roll deflection across the entire length of the roll.
Quarter hard – It is a temper of non-ferrous alloys and some ferrous alloys characterized by tensile strength about midway between that of dead soft and half hard tempers.
Quartering – It is a method of sampling a powder by dividing a cone shaped heap into four parts, selecting one of them randomly, dividing this again into four parts, and repeating the procedure until the sample is small enough for analysis.
Quartering and coning method – It is a method for the reduction in size of a granular or powdered sample by forming a conical heap which is spread out into a circular, flat cake. The cake is divided radially into quarters and two opposite quarters are combined. The other two quarters are discarded. The process is repeated as many times as necessary to obtain the quantity desired for some final use (e.g. as the laboratory sample or as the test sample). If the process is performed only once, coning and quartering is no more efficient than taking alternate portions and discarding the others.
Quarterly report – It is the progress report of an activity which is made once in quarter (3 months).
Quarter turn – It means a rotation of 90-degree, which is one-fourth of a full rotation or circle.
Quarter-wave plate – It consists of a carefully adjusted thickness of a birefringent material such that the light associated with the larger index of refraction is retarded by 90-degree in phase (a quarter wave-length) with respect to that associated with the smaller index. The material is cut so that the optic axis is parallel to the front and back plates of the plate. Any linearly polarized light which strikes the plate is to be divided into two components with different indices of refraction. One of the useful applications of this device is to convert linearly polarized light to circularly polarized light and vice versa. This is done by adjusting the plane of the incident light so that it makes 45-degree angle with the optic axis. This gives equal amplitude o-waves and e-waves. When the o-wave is slower, as in calcite, the o-wave falls behind by 90-degree in phase, producing circularly polarized light.
Quartile – In statistics, quartiles are values which divide a dataset into four equal parts, with the first quartile (Q1) representing the 25th percentile, the second quartile (Q2) being the median (50th percentile), and the third quartile (Q3) representing the 75th percentile.
Quartz – It is the common rock-forming mineral consisting of silicon and oxygen.
Quartz dilatometer – It is a device which measures how much a material’s length changes when its temperature changes. The dilatometer is used to measure changes in linear dimensions and to determine the coefficients of linear thermal expansion of solids. The principle of operation of a dilatometer is to measure the change in the size of the sample when the temperature changes.
Quartzite – It is a metamorphic rock which is formed by the transformation of a sand-stone by heat and pressure. It is the ore which is very rich in silica and is added in blast furnace as additive.
Quartzite, ganister – For refractories, it is a rock consisting predominantly of the mineral quartz suitable for the manufacture of silica brick and characterized by a high silica (SiO2) content and a low percentage of impurities.
Quartz thermometer – It is a high-precision, high accuracy temperature sensor. It measures temperature by measuring the frequency of a quartz crystal oscillator. The oscillator contains a specially cut crystal that results in a linear temperature coefficient of frequency, so the measurement of the temperature is essentially reduced to measurement of the oscillator frequency. Resolutions of 0.0001 deg C, and accuracy of 0.02 deg C from 0 deg G to 100 deg C, are achievable. The high linearity makes it possible to achieve high accuracy over an important temperature range which contains only one convenient temperature reference point for calibration, the triple point of water.
Quasi-binary section on a ternary phase diagram – It refers to a line or plane sliced through the ternary diagram which essentially acts like a binary phase diagram, focusing on the relationship between two components while treating a third component as essentially fixed at a specific concentration, allowing for analysis of the system as if there is only two components involved. This is frequently used when a ternary system contains a stable intermediate compound which forms a near-binary relationship with one of the pure components.
Quasi-binary system – In a ternary or higher-order system, it is a linear composition series between two substances each of which shows congruent melting, wherein all equilibria, at all temperatures or pressures, involve only phases having compositions occurring in the linear series, so that the series can be represented as a binary on a phase diagram.
Quasi-cleavage fracture – It is a term which is used to refer to a fracture mode which combines the characteristics of cleavage fracture and dimpled fracture or tear ridges. The term is used to describe a micro-scale fracture appearance in steels which tends to result from (i) sudden or impact loading, (ii) low temperature, (iii) high levels of constraint (ambient temperature), or (iv) in heavily cold worked parts (ambient temperature). The preferred term is cleavage with ductile tear ridges. Quasi-cleavage fracture is an intermediate type of fracture which is found in certain high-strength metals.
Quasi-crystal – It is a structure which is ordered but not periodic. A quasi-crystalline pattern can continuously fill all available space, but it lacks translational symmetry. Quasi-crystals are stable phases of condensed matter which show crystalline features such as symmetry and repeating patterns of unit cells. While crystals, as per the classical crystallographic restriction theorem, can possess only two-fold, three-fold, four-fold and six-fold rotational symmetries, the Bragg diffraction pattern of quasi-crystals shows sharp peaks with other symmetry orders, e.g., five-fold.
Quasi-flake graphite – It is a type of degenerated graphite that can occur in cast iron. It is normally the result of insufficient magnesium additions to produce the fully spheroidal form.
Quasi-isotropic – It refers to material in which statistical uniformity exists, such as poly-crystalline metals.
Quasi-isotropic laminate – It is a laminate approximating isotropy by orientation of plies in several or more directions.
Quaternary system – It is the complete series of compositions produced by mixing four components in all proportions. It is a system which has four components, e.g., molybdenum-silicon-boron-titanium quarternary system. The quaternary system of aluminum-copper-magnesium-zinc is one of the key systems of high-strength aluminium alloys extensively used in aircraft construction and in other high-strength applications. Another example is the quaternary system of CaO-Al2O3-Fe2O3-SiO2. This system is of most relevance to cements, with more than 95 % of the composition of Portland and aluminous cements coming from compounds containing calcium, aluminium, silicon and iron oxides. A reliable thermodynamic description of a quaternary system can be obtained in several cases from those of its constituent lower systems, that is, binaries and ternaries. The exceptions are when a new quaternary phase occurs or the range of homogeneity of a lower order phase extends significantly into the quaternary compositional space.
Quaternary system phase diagram – This is a phase diagram which represents a quarternary system. This phase diagram is a graphical representation which depicts the different phases of a system containing four components under varying conditions like temperature and pressure, visualized as a 3D tetrahedron where each corner represents one of the four components. Essentially, it shows which phases are present in a system with four different substances depending on their relative compositions. In order to visualize the phase diagram of a quaternary system under constant temperature and pressure, one needs three dimensions. Representation of the quaternary system in two dimensions presents certain difficulties owing to its complexity and the unavoidable superimposition of phase fields.
Quays – Quays are the ship handling areas beside the ship berths within each terminal, complete with shore equipment to handle cargo, sheds, cargo storage areas, cargo discharge areas. A quay basically refers to the land area surrounding a ship berth. It is a structure on the shore of a harbour or on the bank of a river or canal where ships can dock to load and unload cargo or passengers.
Quebec metal powder process – It involves conversion of smelted liquid metal to create high-purity, high-compressibility metal powders. The process steps involved includes holding the metal in induction furnace, granulation, drying, ball grinding, decarburization / annealing, grinding, blending, and packaging.
Queen post – It is a tension member in a truss which can span longer openings than a king post truss. A king post uses one central supporting post, whereas the queen post truss uses two. Even though it is a tension member, rather than a compression member, they are commonly still called a post. A queen post is frequently confused with a queen strut, one of two compression members in roof framing which do not form a truss in the engineering sense.
Queen strut – A queen strut is a pair of struts which fit between a tie beam and a collar beam in a roof truss. Queen struts are used in a variety of roof constructions, including box-frame construction, closed trusses, and kerb principal.
Quench-age embrittlement – It is the embrittlement of low-carbon steels resulting from precipitation of solute carbon at existing dislocations and from precipitation hardening of the steel caused by differences in the solid solubility of carbon in ferrite at different temperatures. Quench-age embrittlement normally is caused by rapid cooling of the steel from temperatures slightly below Ac1 temperature (the temperature at which austenite begins to form), and can be minimized by quenching from lower temperatures.
Quench aging – It is aging induced by rapid cooling after solution heat treatment. It is a change in properties which can occur gradually at atmospheric temperature and more rapidly at higher temperature following rapid cooling (precipitation hardening).
Quench annealing – It consists of annealing of an austenitic ferrous alloy by solution heat treatment followed by rapid quenching.
Quenchant – It is a liquid or a gas used to rapidly cool a material during heat treatment. One of the most important functions of a quenchant is mediation of heat transfer and facilitation of uniform heat transfer throughout the quenching process. The selection of a quenchant medium depends on the hardenability of the particular alloy, the section thickness and shape involved, and the cooling rates needed to achieve the desired microstructure. The liquid quenchants normally used include (i) oil which can contain a variety of additives, (ii) water, (iii) aqueous polymer solutions, or (iv) water which can contain salt or caustic additives. The most common gaseous quenchants are inert gases including helium, argon, and nitrogen. These quenchants are sometimes used after austenitizing in a vacuum. The ability of a quenchant to harden steel depends on the cooling characteristics of the quenching medium. Quenching effectiveness is dependent on the steel composition, type of quenchant, or the quenchant use conditions.
Quench crack – It is a crack which is formed as a result of stresses created by thermal gradients and volumetric changes because of the phase transformations (e.g., austenite to martensite transformation).
Quench cracking – It is the fracture of a metal which takes place during quenching from high temperature. It is very frequently observed in hardened carbon steel, alloy steel, or tool steel parts of high hardness and low toughness. Cracks frequently emanate from fillets, holes, corners, or other stress raisers and result from high stresses because of the volume changes accompanying transformation to martensite.
Quenched and tempered reinforcement bars – These are also known as thermo-mechanically treated (TMT) reinforcement bars (rebars). These bars are produced by the application of the technology of quenching and tempering of the bars during its production in the rolling mill. The reinforcement bars produced by this technology are basically made from plain low carbon steels and are specified for yield strength, ductility, carbon or carbon equivalent and yield to tensile ratio. The maximum and minimum specified carbon content intends to ensure weldability and hardenability. The production process of these reinforcement bars is based on the thermo-mechanical processing. Thermo-mechanical process is a metallurgical process which combines plastic deformation process with the thermal processes such as the heat-treatment, water quenching, heating, and cooling at different rates into a single process. The process imparts high strength to the reinforcement bars by the technique of thermo mechanical treatment as against mechanical working by cold twisting which is used for the manufacture of Torsteel reinforcement bars. The strength of the reinforcement bar is because of the tempered martensite layer while the ductility of the reinforcement bar is because of the ferrite- pearlite layer. The thermo mechanical treatment converts the reinforcement bar surface to a hardened structure (martensite) and subsequently the phase evolves by cooling at ambient temperature to allow the hot core to temper the surface through thermal exchange. This results in a unique composite microstructure comprised of tempered martensite in the peripheral zone / case, transition zone of pearlite and bainite just after the martensite periphery and a fine grain ferrite-pearlite at the central zone / core.
Quench embrittlement – It is a potential consequence of the quenching process, which involves rapidly cooling a metal after heating it to a high temperature. It associates with intergranular brittle fracture and takes place in steels with carbon content higher than 0.5 % in both the as-quenched and low-temperature tempered conditions.
Quench factor – It is a parameter which measures the rate of precipitation during quenching, and is used to predict the properties of materials. It can be used to predict the hardness and strength of aluminum alloys. Quench factor is defined as ‘t’, where ‘t’ is the time (sec), and Ct is the critical time. The collection of the ‘Ct’ points, also known as the C-curve, is like the time-temperature-transformation curve for continuous cooling.
Quench factor analysis – It is a method which uses a single number to reflect the overall hardening process. It is based on the principle that steel hardening can be predicted by segmenting a cooling curve into discrete temperature-time increments. The quench factor is calculated from digital time-temperature (cooling curve) data.
Quench hardening – It is the hardening of suitable-alloys (very frequently certain copper to titanium alloys) by solution treating and quenching to develop a martensitic-like structure. In ferrous alloys, it is the hardening by austenitizing and then cooling at a rate such that a substantial quantity of austenite transforms to martensite.
Quenching – It is the rapid cooling of metals (frequently steels) from a suitable high temperature. This is normally accomplished by immersion in water, oil, polymer solution, or salt, although forced air is sometimes used. Types of quenching include brine quenching, caustic quenching, direct quenching, fog quenching, forced-air quenching, hot quenching, intense quenching, interrupted quenching, oil-quenching, press quenching, selective quenching, spray quenching, time quenching, and water quenching. In case of galvanizing, quenching is rapid cooling by dipping galvanized steel in a tank filled with a liquid solution which is normally water or a dilute chromate or phosphate solution.
Quenching and tempering – It is a heat treatment process which used to improve the mechanical properties of metals and alloys. The process involves heating the material to a high temperature, then cooling it rapidly (quenching), followed by reheating it to a lower temperature (tempering). This combination of heating, cooling, and reheating produces significant changes in the micro-structure and properties of the material.
Quenching crack – It is the crack which is formed in a metal as a result of thermal stresses produced by rapid cooling from a high temperature.
Quenching media – It refers to the material which absorbs heat from the metals during the quenching process. There are several quenching mediums which can be chosen from. Each medium offers its unique advantages and limitations. The type of quenching medium selected depends upon factors such as the desired cooling rate, material properties, cost, reusability, and environmental impact. Different quenching media are water, oils, brine (salt water), inert gases, air and polymers.
Quench modification – It is a technique which is used for the modification in the micro-structure of the metals and alloys. The modification takes place because of the rapid cooling during quench treatment.
Quench modified eutectic – It is the eutectic micro-structure which has been modified because of the rapid cooling. This eutectic has improved properties.
Quenching of coke, dry – It is an energy saving process used during the production of coke in the coke oven battery. In this process, the red-hot coke is cooled by gas circulating in an enclosed system, hence preventing the release of airborne coke dust. The thermal energy of the red-hot coke, which is lost in the conventional coke wet quenching process, is collected and reused as steam in the coke dry quenching system. This technology helps in reduction in the consumption of less fossil fuel and results in lower carbon di-oxide emissions, hence contributing to the prevention of global warming.
Quenching of coke, wet – In this process, the red-hot coke which is pushed from the coke oven is cooled by spraying water on the hot coke. The water used for cooling is vapourized and released into the atmosphere. An issue with this conventional process is the energy loss which occurs when the thermal energy of the red-hot coke is converted into the steam which is vapourized and released in the environment unused. Another drawback is that this process also produces airborne coke dust, and hence, the process is associated with high carbon di-oxide emissions and thermal energy loss. Further, during the cooling of the run of oven coke, sensible heat of the hot coke is dissipated into the atmosphere and is lost. In addition, there are air borne emissions (0.5 ton of steam per ton of coke, which is laden with phenol, cyanide, sulphide and dust) and a large quantity of water (around 0.6 cubic meter per ton of coke) is needed for wet quenching. The contaminants in water are also discharged in the environment.
Quenching oil – It is the oil used for quenching metals during a heat-treating operation. Majority of the quenching oils are derived from petroleum oil base-stocks, and the hydro-carbon fractions are classified as paraffinic, naphthenic, and aromatic. The ratio of these hydro-carbon components in the petroleum base-stock used to formulate a quenching oil determines the viscosity, viscosity-temperature, surface wetting, sludging, staining, and fire-resistant properties. Quenching oils are selected on the basis of their ability to mediate heat transfer during quenching. Quenching oils are normally classified on the basis of their quenching speed and application temperature as (i) conventional (non-accelerated) oils or cold oils, (ii) accelerated oils, and (iii) marquenching oils or hot oils. Although there are other classifications such as fast, superfast, and water emulsifiable, the above three classifications are the most commonly encountered.
Quench press – It is a machine which uses concentrated forces to hold an object as it is quenched. These types of quench facilities are used to quench large gears and other circular parts so that they remain circular. They are also used to quench saw blades and other flat or plate-shaped objects so that they remain flat. Quench presses are able to quench the part while it is being held because of the unique structure of the clamps holding the part. Clamps are slotted so that oil or water can flow through each slot and cool the part and the ribs of the clamps can hold the part in place.
Quench severity – it is expressed by the Grossmann H-value (or number). It is the ability of a quenching medium to extract heat from a hot work-piece. It is the rate at which a quenching medium removes heat from a hot metal part. It is a measure of how quickly a quenching medium can harden a metal.
Quench severity index – It is represented by Grossmann number (H), which is a ratio describing the ability of a quenching medium to extract heat from a hot steel-work-piece in comparison to still water. It is defined by the equation H = h/2k, where ‘h’ is the heat transfer coefficient and ‘k’ is the conductivity of the metal.
Quench uniformity – It refers to the consistency of cooling rates across a metal part during quenching. Both the cooling rate and uniformity are important factors in determining the best quenching media for a part.
Quick opening valves – In this type of valves, a small quantity of valve travel produces a large valve stroke.
Quick plastic forming (QPF) process – It is a hot blow forming process developed for the automotive industry to rapidly mass manufacture aluminum alloy and magnesium alloy automotive panels in large volumes at 3 minutes to 6 minutes forming times. The process utilizes dry lubricants, tool surface coatings, rapid preheating of the blanks, self-heated tools, fast automated robotic assisted material handling systems, pressure tight seal at the tool blank interface, and pre-programed pressure time curve. Quick plastic forming enabled manufacturing of a single integrated automotive vehicle panel in aluminum or magnesium alloy which is more geometrically complex than those attainable with multiple stamped pieces of steel. Quick plastic forming process today is used to manufacture light weight automotive components from aluminum and magnesium such as doors, fenders, decklids, liftgates, roofs and bodyside panels.
Quick-release belt fastener – It is a belt fastening system which allows for easy and rapid removal and replacement of conveyor belts. Regular checks are necessary to ensure the secure fastening and integrity of the conveyor belt.
Quick-release chain link – It is a chain link design which enables swift and convenient removal and replacement of conveyor chains. Periodic inspections are necessary to assess wear, alignment, and overall chain condition.
Quick setting cement – As the name indicates this type of cement sets quickly. This property is brought out by reducing the gypsum content at the time of the clinker grinding. This cement is required to mix, to place and to compact very easily. This cement is normally used for the underwater construction.
Quinary system phase diagram – It is a graphical representation which depicts the different phases (solid, liquid, and gas) that can exist in a system composed of five different components, showing how these phases change with varying conditions like temperature and pressure, and how the composition of each phase varies depending on the relative quantities of the five components present.
Quincunx – In statistics, a quincunx is a machine or arrangement of pins that demonstrates probability distributions. It’s also known as a bean machine.
Quincunx pattern – In numerical analysis, the quincunx pattern describes the two-dimensional five-point stencil, which is a sampling pattern used to derive finite difference approximations to derivatives. The five points of the five-point stencil are arranged directly above, below, and to the two sides of the centre point, rather than (as in quincunx sampling) diagonally with respect to it.
Quotation – It is a document that a seller provides to a buyer to offer goods or services at a stated price, under specified conditions. It is also known as quotes, sales quotes or sales quotations. Quotations are used to let a potential buyer know how much goods or services are going to cost before they commit to the purchase. Quotations are normally not legally binding unless they are part of an official contract. However, it is normally accepted that a customer has committed to a sale, and a specific price, if they accept the quote.
Quotas – Emissions trading in international systems is known as quotas.
Quotient – It is a quantity produced by the division of two numbers. The quotient has widespread use throughout mathematics. It has two definitions, either the integer part of a division (in the case of Euclidean division) or a fraction or ratio (in the case of a general division). In metrology (International System of Quantities and the International System of Units), ‘quotient’ refers to the general case with respect to the units of measurement of physical quantities. Ratios is the special case for dimensionless quotients of two quantities of the same kind. Quotients with a non-trivial dimension and compound units, especially when the divisor is a duration (e.g., ‘per seconds’), are known as rates.
Q-value -It is a quality factor of a magnetic material. It is also called energy factor or coil magnification factor. It represents the ratio of the reactance of a coil to its series resistance. Its specific change with the frequency is a function of the type and composition of the magnetic powder used for the core.
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