Introduction Three basic components, resistors, capacitors, and inductors, are very important elements in electrical circuits as individual devices, or together. Resistors are used as loads, delays, and current limiting devices. Capacitors are used as dc blocking devices, in level shifting, integrating, differentiating, frequency determination, selection, and delay circuits. Inductors are used for frequency selection and ac blocking, in analog meter movements and relays, and are the basis for transformers and motors.
What’s Admixtures? Admixtures are anything other than portland cement, water, and aggregates that are added to a concrete mix to modify its properties. Included in this definition are chemical admixtures (ASTM C494 and C260), mineral admixtures such as fly ash (C618) and silica fume, corrosion inhibitors, colors, fibers, and miscellaneous (pumping aids, dampproofing, gas-forming, permeability-reducing agents).
Chemical and mineral admixtures Chemical admixtures used in concrete generally serve as water reducers, accelerators, set retarders, or a combination.
Introduction Bdmeter has developed this Occupational Health and Safety toolkit to support you to:
Understand what a robust occupational health and safety system means for your business; Make the case with factory management and other colleagues to invest in this area and support you; Assess the performance of your current health and safety system; Identify areas where you can improve and develop action plans to improve your health and safety system.
The Industrial Revolution stands as a turning point in human history, marking a radical shift from agrarian societies to industrialized nations. Spanning from the late 18th to the early 19th century, this transformative period brought about profound changes in technology, manufacturing, transportation, and society at large. In this 15,000-word blog, we will delve into the various facets of the Industrial Revolution, exploring its causes, impact, and lasting legacy.
I. Prelude to Change: The Factors Igniting the Industrial Revolution 1.
Construction cost of a building usually is a dominant design concern. One reason is that if construction cost exceeds the owner’s budget, the owner may cancel the project. Another reason is that costs, such as property taxes and insurance, that occur after completion of the building often are proportional to the initial cost. Hence, owners usually try to keep that cost low. Designing a building to minimize construction cost, however, may not be in the owner’s best interests.
An air-water mixture is found from the heat and mass balance to be at 60°C (333 K) and 0.025 kg/kg (25 g/kg) absolute humidity. Calculate the other main parameters for the mixture. Take atmospheric pressure as 101,325 Pa.
Method: Consult item (vi) in Table 12-5 for the calculation methodology.
From the initial terminology section, specific humidity YW = 0.02439 kg/kg, mole ratio z = 0.0402 kmol/kmol, mole fraction y = 0.
Smoke and Chemical Sensors: The detection of smoke, radiation, and chemicals is of great importance in industrial processing not only as it relates to the safety of humans and the control of environmental pollution both atmospheric and ground but is also used in process control applications to detect the presence, absence, or levels of impurities in processing chemicals.
Smoke detectors and heat sensors (automatic sprinklers) are now commonplace in the industry for the protection of people, and equipment, and for monitoring and control of chemical reactions.
Process Control In order to produce a product with consistently high quality, tight process control is necessary. A simple-to-understand example of process control would be the supply of water to a number of cleaning stations, where the water temperature needs to be kept constant in spite of the demand. A simple control block is shown in Fig. 1.1a, steam, and cold water are fed into a heat exchanger, where heat from the steam is used to bring the cold water to the required working temperature.
Portland cement, the most common of modern cement, is made by carefully blending selected raw materials to produce a finished material meeting the requirements of ASTM C150 for one of eight specific cement types. Four major compounds [lime (CaO), iron (Fe2O3), silica (SiO2), and alumina (Al2O3)] and two minor compounds [gypsum (CaSO4 2H2O) and magnesia (MgO)] constitute the raw materials. The calcareous (CaO) materials typically come from limestone, calcite, marl, or shale.
Cementitious materials include the many products that are mixed with either water or some other liquid or both to form a cementing paste that may be formed or molded while plastic but will set into a rigid shape. When sand is added to the paste, mortar is formed. A combination of coarse and fine aggregate (sand) added to the paste forms concrete.
Types of cementitious materials There are many varieties of cement and numerous ways of classification.
What is lightning or Thunder? Lightning, a high-voltage, high-current electrical discharge between clouds and the ground, may strike and destroy life and property anywhere thunderstorms have occurred in the past. Buildings and their occupants, however, can be protected against this hazard by the installation of a special electrical system. Because an incomplete or poor installation can cause worse damage or injuries than no protection at all, a lightning-protection system should be designed and installed by experts.