Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Granite Dust as a Sustainable Additive
The increase in infrastructure requirement drives people to use all types of soils, including poor soils. These poor soils, which are weak at construction, must be improved using different techniques. The extinction of natural resources and the increase in cost of available materials require us to think of alternate resources. The usage of industry by-products and related methods for improving the properties of different soils has been studied for several years. Granite dust is an industrial by-product originating from the primary crushing of aggregates. The production of huge quantities of granite dust in the industry causes severe problems from the handling to the disposal stage. Accordingly, in the civil engineering field, the massive utilization of granite dust has been proposed for various applications to resolve these issues. 
  • 1.7K
  • 21 Dec 2021
Topic Review
Terahertz Emitter Using Resonant-Tunneling Diode
The terahertz (THz) band, which has a frequency of about 0.1 to several THz, is expected to play key roles in various applications, such as imaging, chemical and bio-technological analyses, and communications. Compact solid-state THz sources are important devices for these applications and various kinds of such sources have been studied, comprising both optical and electronic devices, as the THz band is located between millimeter and light waves.
  • 1.7K
  • 08 Apr 2021
Topic Review
Relationship Between Rock Textural Characteristics and Mechanical Properties
The textural characteristics of rocks influence their petrophysical and mechanical properties. Such parameters largely control rock mass stability. The ability to evaluate both immediate and long-term rock behaviors based on the interaction between various parameters of rock texture, petrophysical and mechanical properties is therefore crucial to many geoengineering facilities. The mechanical properties of a rock largely depend on its petrographic or textural characteristics. Some quantitative associations between rock petrographic characteristics and mechanical properties have been found. Therefore, the effects of these relationships on the mechanical characteristics of rock, and their extents, must be well understood as a proper frame of reference if good rock cores are unavailable for reliable tests intended to characterize rock mass.
  • 1.7K
  • 19 May 2022
Topic Review
Intermediate Strain Rate Testing Devices
The existing experimental tests are mainly designed to study the mechanical response of materials at various strain rates. Many researchers performed the experimental test in tension, compression, and shear (with torsion test) over a wide range of strain rates. They found out that material exhibits an increase in yield stress as well as flows stress with an increase in strain rate. It illustrates that there is a need for experimental data to study the material behaviour over the full range of strain rates, from quasi-static to high strain rate test. Many special techniques have been developed to bridge the strain rate gap between quasi-static and high strain rate testing to provide a method for an intermediate strain rate test for engineering materials. Some researchers have tried to conduct intermediate strain rate tests with standard servo-hydraulic load frames. However, the results of such tests are not accurate. The problem is that during the experiment, the whole machine is not in static equilibrium. The inertial effect influences the experimental data. The records obtained from these machines are often noisy with large oscillation. therefore, the comprehensive review is given to describes the development and evolution of the existing intermediate strain rate testing devices which includes the working principles, some critical theories, technological innovation in load measurement techniques, components of the device, basic technical assumption, and measuring techniques. In addition, some research direction on future implementation and development of an intermediate strain rate apparatus is also discussed in detail.
  • 1.7K
  • 18 Apr 2021
Topic Review
North–South Commuter Railway
The North–South Commuter Railway (NSCR), also known as the Clark–Calamba Railway, is a 148 km (92 mi) urban rail transit line being constructed in Luzon. It will run from New Clark City in Capas, Tarlac to Calamba, Laguna with 36 stations, with historic stations to be restored. Originally planned in the 1990s, the project has been repetitively halted after disagreements on funding and allegations of overpricing. The first proposal was the 32 km (20 mi) "Manila–Clark rapid railway" with Spain, and during the 2000s, the NorthRail project with China that was discontinued in 2011. The present line is under the Duterte administration and is to be aided with Japanese financing. It was initially reported to have a total length of 180 km (110 mi), though it was reduced to 148 kilometers (92 mi) after a segment to Los Baños was scrapped. The railway system is expected to cost ₱777.55 billion (US$14.95 billion), making it one of the most expensive projects of the Build! Build! Build! Infrastructure Program. Partial operations will begin by 2021, and full operations is expected to begin by 2025. The NSCR will comprise two sections corresponding to the Philippine National Railways' old main lines; the 91 km (57 mi) fully-elevated NSCR North which is being built over the mostly-defunct North Main Line in northern Metro Manila and Central Luzon, and the 56 km (35 mi) NSCR South which will use the existing PNR Metro Commuter Line infrastructure between Tutuban and Calamba, which were historically parts of the South Main Line and will have elevated, at-grade and depressed sections. The project's construction is divided into three phases with the NSCR North being separated between the 38 km (24 mi) NSCR North 1 commuter line between Tutuban and Malolos, and the 53 kilometres (33 mi) NSCR North 2 regional line from Malolos to New Clark City. It will also be linked to existing and future railway lines such as Line 8, Line 9, the Calamba–Bicol South Main Line and Calamba–Batangas City Railway.
  • 1.7K
  • 09 Oct 2022
Topic Review
Room Temperature Sodium Sulfur Batteries
Lithium metal batteries have achieved large-scale application, but still have limitations such as poor safety performance and high cost, and limited lithium resources limit the production of lithium batteries. The construction of these devices is also hampered by limited lithium supplies. Therefore, it is particularly important to find alternative metals for lithium replacement. Sodium has the properties of rich in content, low cost and ability to provide high voltage, which makes it an ideal substitute for lithium. Sulfur-based materials have attributes of high energy density, high theoretical specific capacity and are easily oxidized. They may be used as cathodes matched with sodium anodes to form a sodium-sulfur battery. Traditional sodium-sulfur batteries are used at a temperature of about 300 °C. In order to solve problems associated with flammability, explosiveness and energy loss caused by high-temperature use conditions, most research is now focused on the development of room temperature sodium-sulfur batteries. Regardless of safety performance or energy storage performance, room temperature sodium-sulfur batteries have great potential as next-generation secondary batteries. This article summarizes the working principle and existing problems for room temperature sodium-sulfur battery, and summarizes the methods necessary to solve key scientific problems to improve the comprehensive energy storage performance of sodium-sulfur battery from four aspects: cathode, anode, electrolyte and separator.
  • 1.7K
  • 06 Apr 2021
Topic Review
Electricity Demand Forecasting
With the globally increasing electricity demand, its related uncertainties are on the rise as well. Therefore, a deeper insight into load forecasting techniques for projecting future electricity demands becomes imperative for business entities and policymakers. The electricity demand is governed by a set of different variables or “electricity demand determinants”. These demand determinants depend on forecasting horizons (long term, medium term, and short term), the load aggregation level, climate, and socio-economic activities. In this paper, a review of different electricity demand forecasting methodologies is provided in the context of a group of low and middle-income countries. The article presents a comprehensive literature review by tabulating the di fferent demand determinants used in di fferent countries and forecasting the trends and techniques used in these countries. A comparative review of these forecasting methodologies over di fferent time horizons reveal that the time series modeling approach has been extensively used while forecasting for long and medium terms. For short term forecasts, artificial intelligence-based techniques remain prevalent in the literature. Furthermore, a comparative analysis of the demand determinants in these countries indicates frequent use of determinants like the population, GDP, weather, and load data over di fferent time horizons.
  • 1.7K
  • 05 Aug 2020
Topic Review Peer Reviewed
Energy Storage Flywheel Rotors – Mechanical Design
Definition: Energy storage flywheel systems are mechanical devices that typically utilize an electrical machine (motor/generator unit) to convert electrical energy in mechanical energy and vice versa. Energy is stored in a fast-rotating mass known as the flywheel rotor. The rotor is subject to high centripetal forces requiring careful design, analysis, and fabrication to ensure the safe operation of the storage device.
  • 1.6K
  • 13 Apr 2022
Topic Review
Side Lobe
In antenna engineering, side lobes or sidelobes are the lobes (local maxima) of the far field radiation pattern of an antenna or other radiation source, that are not the main lobe. The radiation pattern of most antennas shows a pattern of "lobes" at various angles, directions where the radiated signal strength reaches a maximum, separated by "nulls", angles at which the radiated signal strength falls to zero. This can be viewed as the diffraction pattern of the antenna. In a directional antenna in which the objective is to emit the radio waves in one direction, the lobe in that direction is designed to have a larger field strength than the others; this is the "main lobe". The other lobes are called "side lobes", and usually represent unwanted radiation in undesired directions. The side lobe directly behind the main lobe is called the back lobe. The longer the antenna relative to the radio wavelength, the more lobes its radiation pattern has. In transmitting antennas, excessive side lobe radiation wastes energy and may cause interference to other equipment. Another disadvantage is that confidential information may be picked up by unintended receivers. In receiving antennas, side lobes may pick up interfering signals, and increase the noise level in the receiver. The power density in the side lobes is generally much less than that in the main beam. It is generally desirable to minimize the sidelobe level (SLL), which is measured in decibels relative to the peak of the main beam. The main lobe and side lobes occur for both transmitting and receiving. The concepts of main and side lobes, radiation pattern, aperture shapes, and aperture weighting, apply to optics (another branch of electromagnetics) and in acoustics fields such as loudspeaker and sonar design, as well as antenna design. Because an antenna's far field radiation pattern is a Fourier Transform of its aperture distribution, most antennas will generally have sidelobes, unless the aperture distribution is a Gaussian, or if the antenna is so small as to have no sidelobes in the visible space. Larger antennas have narrower main beams, as well as narrower sidelobes. Hence, larger antennas have more sidelobes in the visible space (as the antenna size is increased, sidelobes move from the evanescent space to the visible space).
  • 1.7K
  • 28 Nov 2022
Topic Review
DNA-Based Biosensors
Due to superior biocompatibility, thermal stability, and alternative functionalization, deoxyribonucleic acid (DNA) is becoming a fascinating biological material used for biosensing. It is widely acknowledged that DNA and its assembly structure can be applied for detecting specific targets, including nucleic acids, proteins, metal ions, and small biological molecules. With the development of DNA nanotechnology, dynamic networks based on DNA hybridization can be used to amplify the signals of biosensors.
  • 1.7K
  • 07 Apr 2022
  • Page
  • of
  • 650
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
ScholarVision Creations
Feedback