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Topic Review
Biography
Topic Review
Physical Sensing and Multimode Optical Waveguides
The research asks for meta-changes. As an example, a paradigm change in the use of the plasmonic phenomena produces innovative sensors. In particular, the sensor systems based on this innovative sensing approach were designed, fabricated, and investigated to assess their ability to measure various physical features, such as magnetic field, temperature, force, and volume. In a similar way, highly sensitive chemical sensors can be realized.
322
20 Jun 2023
Topic Review
Paramagnetic Meissner Effect (PME)
When cooling a superconductor in a magnetic field below the transition temperature, Tc, the material characteristically tries to expel the magnetic flux due to the induced shielding currents (often also called Meissner currents). When measuring the magnetic moment, m(T), in this situation a diamagnetic signal (m = negative) appears. This so-called Meissner-Ochsenfeld effect is one of the two hallmarks of superconductivity besides the zero resistance and represents the strongest proof if a material is a true superconductor. However, in the literature there are also superconducting materials which show an appearing paramagnetic (positive m) signal below Tc when measuring m(T) in small applied magnetic fields. This so-called Paramagnetic Meissner Effect (PME) or Wohlleben effect was first observed in bulk, Bi2Sr2CaCu2O8 high- Tc superconducting (HTSc) materials, and subsequently as big surprise also in conventional Nb superconductors. Since then, PME was found in many more metallic and HTSc materials, having various shapes (bulks, crystals, thin films), and various aspect ratios and compositions, including multilayers and doped materials.
386
20 Jun 2023
Topic Review
Quantum Light Source Based on Semiconductor Quantum Dots
Quantum light sources that generate single photons and entangled photons have important applications in the fields of secure quantum communication and linear optical quantum computing. Self-assembled semiconductor quantum dots, also known as “artificial atoms”, have discrete energy-level structures due to electronic confinement in all three spatial dimensions. It has the advantages of high stability, high brightness, deterministic, and tunable emission wavelength, and is easy to integrate into an optical microcavity with a high-quality factor, which can realize a high-performance quantum light source.
368
20 Jun 2023
Topic Review
Halide Perovskites Films for Ionizing Radiation Detection
Halide perovskites are a novel class of semiconductors that have attracted great interest due to their peculiar properties of interest for optoelectronics. In fact, their use ranges from the field of sensors and light emitters to ionizing radiation detectors. Since 2015, ionizing radiation detectors exploiting perovskite films as active media have been developed.
280
15 Jun 2023
Topic Review
Magnetic Properties and Magnetocaloric Effect of Pr
2
Co
7
Compound
The Pr2Co7 compound has interesting magnetic properties, such as a high Curie temperature TC and uniaxial magnetocrystalline anisotropy. It crystallizes in a hexagonal structure (2:7 H) of the Ce2Ni7 type and is stable at relatively low temperatures (Ta ≤ 1023 K), or it has a rhombohedral structure (2:7 R) of the Gd2Co7 type and is stable at high temperatures (Ta ≥ 1223 K). Studies of the magnetocaloric properties of the nanocrystalline Pr2Co7 compound have shown the existence of a large reversible magnetic entropy change (ΔSM) with a second-order magnetic transition.
564
15 Jun 2023
Topic Review
Types of Liquid Crystals
The liquid-crystalline state of matter (mesomorphic state, or mesophase) is intermediate between the crystalline and liquid states, simultaneously showing some of the anisotropic properties of solids and the fluidity of liquids. In this state, materials demonstrate a tendency to flow like liquids and have some properties similar to solids. LCs may be divided into two main classes, named thermotropics and lyotropics. The importance of liquid crystals, alongside with their technical applications, lies in their role as carriers of life. In fact, fully ordered solids are a dead matter, and fully disordered liquids are also dead. But liquid crystals, as partially ordered soft matter systems, bear all qualities that had been necessary for the emergence of life. Practically all biological structures show some features pf liquid crystalline ordering.
628
15 Jun 2023
Topic Review
High-Precision Trace Hydrogen Sensing
Despite its growing importance in the energy generation and storage industry, the detection of hydrogen in trace concentrations remains challenging, as established optical absorption methods are ineffective in probing homonuclear diatomics. Besides indirect detection approaches using, e.g., chemically sensitized microdevices, Raman scattering has shown promise as an alternative direct method of unambiguous hydrogen chemical fingerprinting.
491
13 Jun 2023
Topic Review
Mechanisms of Co-Evolution of Wheat and Rust Pathogens
Wheat (Triticum spp.) is a cereal crop domesticated >8000 years ago and the second-most-consumed food crop nowadays. Ever since mankind has written records, cereal rust diseases have been a painful awareness in antiquity documented in the Old Testament (about 750 B.C.). The pathogen causing the wheat stem rust disease is among the first identified plant pathogens in the 1700s, suggesting that wheat and rust pathogens have co-existed for thousands of years. With advanced molecular technologies, wheat and rust genomes have been sequenced, and interactions between the host and the rust pathogens have been extensively studied at molecular levels.
324
08 Jun 2023
Topic Review
Atom Chips for Absolute Gravity Sensors
As a powerful tool in scientific research and industrial technologies, the cold atom absolute gravity sensor (CAGS) based on cold atom interferometry has been proven to be the most promising new generation high-precision absolute gravity sensor. However, large size, heavy weight, and high–power consumption are still the main restriction factors of CAGS being applied for practical applications on mobile platforms. Combined with cold atom chips, it is possible to drastically reduce the complexity, weight, and size of CAGS.
265
07 Jun 2023
Topic Review
Proximal Sensing
Proximal sensing techniques denote several non-invasive technologies in which the target objects—in the present context, cultural heritage manufacts—are placed within a short distance of the sensor, detector or camera lens collecting the data. Depending on the technology employed and the study purpose, the sensors/detectors work in different portions of the electromagnetic spectrum, from X-ray to ultraviolet (UV), from visible (VIS) to infrared (IR) and, further, from microwave to radio.
625
02 Jun 2023
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