Topic Review
Alternative General-Relativity-related experiments and Particle Physics
The use of quantum optical systems for investigation in General Relativity ad related theories, of which General Relativity is the weak-field limit is exposed; the analyses are based on the comparison of the properties of Astrophysical systems inferred form the quantum-optics techniques, which can compare Planck-scale physics.
  • 243
  • 12 Nov 2024
Topic Review
Assembly Theory
Assembly theory is a framework for quantifying selection, evolution, and complexity. It, therefore, spans various scientific disciplines, including physics, chemistry, biology, and information theory. Assembly theory is rooted in the assembly of an object from a set of basic building units, forming an initial assembly pool and from subunits that entered the assembly pool in previous assembly steps. Hence, the object is defined not as a set of point particles but by the history of its assembly, where the assembly index is the smallest number of steps required to assemble the object.
  • 180
  • 11 Nov 2024
Topic Review
The Kottler-Schwarzschild-Kiselev Spacetimes
The Kottler-Schwarzschild-Kiselev blackhole spacetimes are analytically studied. The instances of the gtt components of the metric tensor are considered, where it contains a linear term, a cosmological constant, and both a linear term and a cosmological constant, in the deSitter determination and in the anti-deSitter one. The Birkhoff theorem is proven to be obeyed. The infinite-redshift surfaces are written. The parameter space of the models which constrain the blackhole mass are analytically spelled out. The coordinate-singularity-avoiding coordinates transformations are newly found. The possibility to obtain a scheme geometrically-mimicking quintessence is ruled out. The weak-field limit is studied from the appropriate Christoffel symbol. The quantum regime is envisaged.
  • 236
  • 11 Nov 2024
Topic Review
American Education
The landscape of education in the United States is in a state of flux, marked by ongoing debates about how best to reform the system to meet the needs of a diverse and changing society.
  • 115
  • 31 Oct 2024
Topic Review Peer Reviewed
The 1H HR-NMR Methods for the Evaluation of the Stability, Quality, Authenticity, and Shelf Life of Foods
1H High-Resolution Nuclear Magnetic Resonance (1H HR-NMR) spectroscopy is a powerful analytical methodology used in various fields, including food science. In the food science field, NMR combined with the principles of metabolomics can provide detailed information about a food’s molecular composition, structure, dynamics, and interactions within food matrices, making it invaluable for assessing changes during storage, processing, and shelf life. This entry aims to list the main applications of one-dimensional 1H HR-NMR methods in the field of food science, such as their use in the assessment of the stability, quality, authenticity, and shelf life of food samples. Several kinds of foods are taken into consideration to give a huge overview of the potentiality of the methods.
  • 104
  • 30 Oct 2024
Topic Review
Transparent Solar Windows
Many modern glass and window products are based on metal-dielectric coatings, which can control properties such as thermal emissivity, heat gain, colour, and transparency. These can also enable solar energy harvesting through PV integration, if the glazing structure is purpose-designed, to include luminescent materials and special microstructures. Recently, significant progress has been demonstrated in building integrated transparent solar windows, which are expected to add momentum towards the development of smart cities. These window systems are, at present in 2019, the only type of transparent and clear construction materials capable of providing significant energy savings in buildings, simultaneously with renewable energy generation.
  • 3.4K
  • 09 Oct 2024
Topic Review Peer Reviewed
On the Origins of Hamilton’s Principle(s)
This entry first provides an overview of the historical, cultural and epistemological background that is key for Hamilton’s positions on mechanics. We consider the investigations on geometrical optics in the 17th and 18th centuries, Euler’s and Lagrange’s foundations of variational calculus in the 18th century to find extrema of physical quantities expressed as infinite sums of infinitesimals (today, we would say ‘definite integrals’), and Lagrange’s introduction of a revolutionary analytical mechanics, all of which are all fertile grounds for Hamilton’s steps—first, in what we could call analytical optics, then in an advanced form of analytical mechanics. Having provided such an overview, we run through some of Hamilton’s original papers to highlight how he posed his principle(s) in the wake of his forerunners and how his principles are linked with the search for a unitary view of physics.
  • 148
  • 29 Sep 2024
Topic Review
Oscillatory Spinning Drop Interfacial Rheology
The oscillatory spinning drop method has been proven recently to be an accurate technique to measure dilational interfacial rheological properties. It is the only available equipment for measuring dilational moduli in low interfacial tension systems, as is the case in applications dealing with surfactant-oil-water three-phase behavior like enhanced oil recovery, crude oil dehydration, or extreme microemulsion solubilization. Different systems can be studied with this method with the lower density phase as the spinning drop, i.e, oil-in-water, microemulsion-in-water, oil-in-microemulsion, including systems with the presence of complex natural surfactants like asphaltene aggregates or particles. The technique allows studying the characteristics and properties of water/oil interfaces, particularly when the oil contains asphaltenes and when surfactants are present. We have found that using the oscillating spinning drop method to measure interfacial rheology properties can help make precise measurements in a reasonable amount of time. This is of significance when systems with long equilibration times, e.g., asphaltene or high molecular weight surfactant-containing systems are measured, or with systems formulated with a demulsifier which is generally associated with optimum formulation and a low interfacial tension.
  • 1.9K
  • 08 Sep 2024
Topic Review
Excess Conductivity Analysis of an YBCO Foam Strut
Magneto-resistance data R(T, B) obtained at temperatures in the range 4.2 K ≤ T ≤ 150 K (applied magnetic fields ranging from 0 to 7 T) were analyzed in the framework of the fluctuation-induced conductivity (FIC) approach using the models of Aslamazov-Larkin (AL) and Lawrence-Doniach (LD). From the R(T, B) curves we determine in a first instance the residual resistivity ρ0, the normal-state resistivity ρn(T), the mean-field transition temperature TcMF (here due to the appearance of two peaks in dρ/dT called Tc1mid and Tc2mid), the temperature T* (the deviation from the linear resistance behavior), and the characteristic temperatures Tconset and Tcoffset. The data of 10% ρn yield information on the irreversibility line (Hirr(T)), and the data of 90% ρn give information on the upper critical field, Hc2(T). This material then serves to obtain the fluctuation induced conductivity (FIC) or excess conductivity. The resulting FIC curves for each applied magnetic field reveal the presence of five distinct fluctuation regimes above the temperature Tcmid, namely, the short-wave (SWF), one-dimensional (1D), two-dimensional (2D), three-dimensional (3D), and critical (CR) fluctuation domains. The analysis of the FIC data enable the coherence length in the direction of the c-axis at zero-temperature (ξc(0)), the lower and upper critical magnetic fields (Bc1, Bc2), the critical current density at T = 0 K (Jc(0)) and several other parameters describing the the material’s superconducting properties to be determined. A proper knowledge of the microstructure of the YBCO foam sample contributes to the understanding of the present data. It is revealed that the minuscule Y-211 particles found along the YBCO grain boundaries alter the excess conductivity and the fluctuation behavior as compared to conventional YBCO samples, leading to a quite high value for Jc(0) for a sample with a non-optimized pinning landscape.
  • 215
  • 28 Aug 2024
Topic Review
The Resonance Structure Units
The construction of structural units is crucial in developing acoustic metasurfaces. These units must fulfill the necessary requirements, including the 2π phase change and being as small as possible. The resonant structure unit that controls large wavelengths with a small size precisely meets this requirement.
  • 169
  • 27 Aug 2024
  • Page
  • of
  • 120
ScholarVision Creations