182 results on '"HAMPEL, G"'
Search Results
2. Neutron velocity distribution from a superthermal solid 2H2 ultracold neutron source.
- Author
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Altarev, I., Daum, M., Frei, A., Gutsmiedl, E., Hampel, G., Hartmann, F., Heil, W., Knecht, A., Kratz, J., Lauer, T., Meier, M., Paul, S., Schmidt, U., Sobolev, Y., Wiehl, N., and Zsigmond, G.
- Subjects
NEUTRON sources ,NEUTRONS ,ULTRACOLD neutrons ,SPECTRUM analysis ,PARTICLES (Nuclear physics) - Abstract
We have determined for the first time the velocity distribution of neutrons from a solid
2 H2 ultracold neutron (UCN) source. The spectrum rises sharply above 4.5m/s and has a maximum around 7m/s after transport in an 8m long guide. The number of neutrons in the UCN velocity range (< 7m/s) may be increased by a factor of two by placing the experiment 1m above the UCN source level. [ABSTRACT FROM AUTHOR]- Published
- 2008
- Full Text
- View/download PDF
3. First production of ultracold neutrons with a solid deuterium source at the pulsed reactor TRIGA Mainz⋆.
- Author
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Frei, A., Sobolev, Yu., Altarev, I., Eberhardt, K., Gschrey, A., Gutsmiedl, E., Hackl, R., Hampel, G., Hartmann, F., Heil, W., Kratz, J., Lauer, Th., Liźon Aguilar, A., Müller, A., Paul, S., Pokotilovski, Yu., Schmid, W., Tassini, L., Tortorella, D., and Trautmann, N.
- Subjects
ULTRACOLD neutrons ,DEUTERIUM ,PULSED reactors ,THERMAL neutrons ,PARTICLES (Nuclear physics) - Abstract
The production rates of ultracold neutrons (UCN) with a solid deuterium converter have been measured at the pulsed reactor TRIGA Mainz. Exposed to a thermal neutron fluence of $\ensuremath \sim 1\cdot 10^{13}$ n·cm^-2·pulse^-1, the number of detected very cold and ultracold neutrons ranges up to 200 000 at 7mol of solid deuterium (sD
2 ) in combination with a pre-moderator (mesitylene). About 50% of the measured neutrons can be assigned to UCN with energies E of $\ensuremath V_{\rm F}({\rm sD}_2)\leq E \leq V_{\rm F}{\rm (guide)}$ where VF ( sD2 ) = 105 neV and VF ( guide) = 190 neV are the Fermi potentials of the sD2 converter and our stainless steel neutron guides, respectively. Thermal cycling of solid deuterium, which was frozen out from the gas phase, considerably improved the UCN yield, in particular at higher amounts of sD2 . [ABSTRACT FROM AUTHOR]- Published
- 2007
- Full Text
- View/download PDF
4. VCl und CrCl als Chloridionendonoren.
- Author
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Gutmann, V., Hampel, G., and Lux, W.
- Abstract
Copyright of Monatshefte Für Chemie Und Verwandte Teile Anderer Wissenschaften is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1965
- Full Text
- View/download PDF
5. Tetraalkylammoniumazide.
- Author
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Gutmann, V., Hampel, G., and Leitmann, O.
- Abstract
Copyright of Monatshefte Für Chemie Und Verwandte Teile Anderer Wissenschaften is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1964
- Full Text
- View/download PDF
6. Chloridionenübergänge in Trimethylphosphat, Acetonitril und Dimethylsulfoxid.
- Author
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Gutmann, V., Hampel, G., and Masaguer, J.
- Abstract
Copyright of Monatshefte Für Chemie Und Verwandte Teile Anderer Wissenschaften is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1963
- Full Text
- View/download PDF
7. Koordinationsformen des Eisen(III)-chlorids in Trimethylphosphat und Dimethylsulfoxid.
- Author
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Gutmann, V. and Hampel, G.
- Abstract
Copyright of Monatshefte Für Chemie Und Verwandte Teile Anderer Wissenschaften is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1963
- Full Text
- View/download PDF
8. Spektrophotometrische Untersuchungen über Chlorokomplexe von Co, Ni und Cu in acetonitril und Trimethylphosphat.
- Author
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Baaz, M., Gutmann, V., Hampel, G., and Masaguer, J.
- Abstract
Copyright of Monatshefte Für Chemie Und Verwandte Teile Anderer Wissenschaften is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1962
- Full Text
- View/download PDF
9. Das Solvosystem Benzoylchlorid, 4. Mitt.: Spektrophotometrische Untersuchungen.
- Author
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Gutmann, V. and Hampel, G.
- Abstract
Copyright of Monatshefte Für Chemie Und Verwandte Teile Anderer Wissenschaften is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1961
- Full Text
- View/download PDF
10. Bedeutung und mikroskopischer Nachweis von Tapiokawurzelmehl.
- Author
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Hampel, G.
- Abstract
Copyright of Zeitschrift für Lebensmittel-Untersuchung und -Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1958
- Full Text
- View/download PDF
11. Über die anatomischen Merkmale von Getreide-Unkrautsamen.
- Author
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Hampel, G.
- Published
- 1958
- Full Text
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12. Über die anatomischen Merkmale von Getreide-Unkrautsamen II. Mitteilung Acker-Schwarzkümmel und Acker-Wachtelweizcn.
- Author
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Hampel, G.
- Published
- 1957
- Full Text
- View/download PDF
13. Über die anatomischen Merkmale von Getreideunkrautsamen. I. Mitteilung Taumelloleh (Lolium temulentum L.).
- Author
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Hampel, G.
- Abstract
Copyright of Zeitschrift für Lebensmittel-Untersuchung und -Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1956
- Full Text
- View/download PDF
14. Eine neue Schnellmethode zur Rohfaserbestimmung.
- Author
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Hampel, G.
- Abstract
Copyright of Zeitschrift für Lebensmittel-Untersuchung und -Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1950
- Full Text
- View/download PDF
15. Industrial Internet for intelligent manufacturing: past, present, and future.
- Author
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Xu, Chi, Yu, Haibin, Jin, Xi, Xia, Changqing, Li, Dong, and Zeng, Peng
- Abstract
Copyright of Frontiers of Information Technology & Electronic Engineering is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
16. Simultaneous removal of caesium and strontium using different removal mechanisms of probiotic bacteria.
- Author
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Endo, Rin, Karasawa, Satoshi, and Aoyagi, Hideki
- Subjects
NUCLEAR power plant accidents ,CESIUM ,RADIOACTIVE elements ,STRONTIUM ,PROBIOTICS ,ELECTRONIC probes ,BIOLOGICAL systems ,BIFIDOBACTERIUM - Abstract
When radioactive materials are released into the environment due to nuclear power plant accidents, they may enter into the body, and exposing it to internal radiation for long periods of time. Although several agents have been developed that help excrete radioactive elements from the digestive tract, only one type of radioactive element can be removed using a single agent. Therefore, we considered the simultaneous removal of caesium (Cs) and strontium (Sr) by utilising the multiple metal removal mechanisms of probiotic bacteria. In this study, the Cs and Sr removal capacities of lactobacilli and bifidobacteria were investigated. Observation using an electron probe micro analyser suggested that Cs was accumulated within the bacterial cells. Since Sr was removed non metabolically, it is likely that it was removed by a mechanism different from that of Cs. The amount of Cs and Sr that the cells could simultaneously retain decreased when compared to that for each element alone, but some strains showed only a slight reduction in removal. For example, Bifidobacterium adolescentis JCM1275 could simultaneously retain 55.7 mg-Cs/g-dry cell and 8.1 mg-Sr/g-dry cell. These results demonstrated the potentials of utilizing complex biological system in simultaneous removal of multiple metal species. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Cypermethrin adsorption by Lactiplantibacillus plantarum and its behavior in a simulated fecal fermentation model.
- Author
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Zhang, Mengmei, Chen, Yuan, Lai, Jinghui, Wang, Xingjie, Hu, Kaidi, Li, Jianlong, Li, Qin, He, Li, Chen, Shujuan, Liu, Aiping, Ao, Xiaolin, Yang, Yong, and Liu, Shuliang
- Subjects
CYPERMETHRIN ,DIFFUSION ,LACTIC acid bacteria ,SORPTION ,FERMENTATION - Abstract
The presence of cypermethrin in the environment and food poses a significant threat to human health. Lactic acid bacteria have shown promise as effective absorbents for xenobiotics and well behaved in wide range of applications. This study aimed to characterize the biosorption behavior of cypermethrin by Lactiplantibacillus plantarum RS60, focusing on cellular components, functional groups, kinetics, and isotherms. Results indicated that RS60 exopolysaccharides played a crucial role removing cypermethrin, with the cell wall and protoplast contributing 71.50% and 30.29% to the overall removal, respectively. Notably, peptidoglycans exhibited a high affinity for cypermethrin binding. The presence of various cellular surface groups including –OH, –NH, –CH
3 , –CH2 , –CH, –P = O, and –CO was responsible for the efficient removal of pollutants. Additionally, the biosorption process demonstrated a good fit with pseudo-second-order and Langmuir–Freundlich isotherm. The biosorption of cypermethrin by L. plantarum RS60 involved complex chemical and physical interactions, as well as intraparticle diffusion and film diffusion. RS60 also effectively reduced cypermethrin residues in a fecal fermentation model, highlighting its potential in mitigating cypermethrin exposure in humans and animals. These findings provided valuable insights into the mechanisms underlying cypermethrin biosorption by lactic acid bacteria and supported the advancement of their application in environmental and health-related contexts. Key points: • Cypermethrin adsorption by L. plantarum was clarified. • Cell wall and protoplast showed cypermethrin binding ability. • L. plantarum can reduce cypermethrin in a fecal fermentation model. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
18. RETRACTED ARTICLE: Enhancing low latency and high performance in clustered-based wireless sensor network routing using genetic algorithm for 5G networks.
- Author
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Banu, Firdouse, Udhayamoorthi, M., Nallagattla, Venkata Ramana Gupta, Maguluri, Lakshmana Phaneendra, Mahesh Kumar, N. B., and Jayachitra, S.
- Abstract
Wireless sensing networks (WSN) have gained widespread acceptance across numerous industries. They are seen as a crucial element of upcoming real-time systems like Big Data with the Internet of Things. Given the heterogeneous nature of the system, contemporary applications demand minimal latency and flexible actual-time data availability. Enable minimal latency actual time information accessibility requires additional energy from sensor devices. Using clustering techniques helped reduce energy usage and provide flexibility for sensing devices. However, it uses power overhead between the sensing unit nearer to the sink with the clustering head. This research presents an enhanced lower latency and energy-effective router dependent sink portability method with WSN. A sink mobility path is developed over the networking region once partitioned into the ideal number of groupings. The GA procedure chooses the best sink positions for every cluster’s path. The movable sink collects information from every node within the associated clusters when it stops at the ideal sink positions. When transmitting information, a good sink position uses the least amount of node power. The GA initializes the community of chromosomes to find the best sink position for groups. Additionally, a network-based energy usage framework is suggested that carries out the GA procedure’ fitness assessing operator. The collection of ideal sink positions on the path for each group is produced by the GA system that has been created. The findings show that, compared to other procedures, GA-based sinking movement increases network reliability. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
19. Measurement of an evaporation coefficient in tissue sections as a correction factor for 10B determination.
- Author
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Espector, Natalia, Portu, Agustina Mariana, Espain, María Sol, Leyva, Gabriela, and Saint Martin, Gisela
- Subjects
EVAPORATION (Meteorology) ,BORON ,NUCLEAR track detectors ,BORON-neutron capture therapy ,CORRECTION factors ,THERMAL neutrons - Abstract
Boron neutron capture therapy (BNCT) is a cancer treatment option that combines preferential uptake of a boron compound in tumors and irradiation with thermal neutrons. For treatment planning, the boron concentration in different tissues must be considered. Neutron autoradiography using nuclear track detectors (NTD) can be applied to study both the concentration and microdistribution of boron in tissue samples. Histological sections are obtained from frozen tissue by cryosectioning. When the samples reach room temperature, they undergo an evaporation process, which leads to an increase in the boron concentration. To take this effect into account, certain correction factors (evaporation coefficients, CEv) must be applied. With this aim, a protocol was established to register and analyze mass variation of tissue sections, measured with a semimicro scale. Values of ambient temperature, pressure, and humidity were simultaneously recorded. Reproducible results of evaporation curves and CEv values were obtained for different tissue samples, which allowed the systematization of the procedure. This study could contribute to a more precise determination of boron concentration in tissue samples through the neutron autoradiography technique, which is of great relevance to make dosimetric calculations in BNCT. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
20. Die einzelnen Lebensmittel (Chemie, Technologie, Analytik).
- Author
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Coduro, E., Matt, F., Voelter, H., Baumgart, J., Lehmann, G., Hampel, G., Heimann, W., Schwerdtfeger, E., Reiners, W., Wilhelm, C., Maier, H., Dultz, G., Radler, F., Thier, H., Schuerdtfeger, E., Philippi, K., Nagy, M., and Hanh, H.
- Published
- 1972
- Full Text
- View/download PDF
21. Die einzelnen Lebensmittel (Chemie, Technologie, Analytik).
- Author
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Pfeiffer, G., Reichenbach-Klinke, H., Guthy, Kl., Acker, L., Hampel, G., Hanssen, E., Rehm, H., Wildbrett, G., Benk, E., Kittner, P., Thier, H., Schwerdtfeger, E., Hohlfeld, W., Wolfseder, H., Feldhein, W., and Luck, E.
- Published
- 1970
- Full Text
- View/download PDF
22. Die einzelnen Lebensmittel (Chemie, Technologie, Analytik).
- Author
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Hampel, G., Rohrlich, M., Adler, G., Lohmann, R., Kuchinke, E., Lechner, E., Maier, H., Herrmann, S., and Wiesner, H.
- Published
- 1969
- Full Text
- View/download PDF
23. Die einzelnen Lebensmittel (Chemie, Technologie, Analytik).
- Author
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Nernst, Ch., Lindner, A., Möhler, Kl., Terplan, G., Zaadhof, K., Karg, H., Rauch, W., Hampel, G., Acker, L., Hohlfeld, W., Baumgart, J., Drawert, F., Kuchinke, E., Lindemann, B., v. Ammon, Bucksteeg, W., and Quentin, K.
- Published
- 1968
- Full Text
- View/download PDF
24. Die einzelnen Lebensmittel (Chemie, Technologie, Analytik).
- Author
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Lott, G., Dietrich, R., Hampel, G., Plaut, M., Liebster, G., Karnatz, Kohn, R., Kuchinke, K., Wassermann, L., Quentin, K., Eichelsdörfer, D., Krämer, B., Lück, E., Bär, F., and Acker, L.
- Published
- 1964
- Full Text
- View/download PDF
25. Rovibrational Transition Properties of System X1Σ+–A1Π of CO.
- Author
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Sun, S., Gao, Y., and Zhu, Z.
- Abstract
The potential energy curves of the X
1 Σ+ and A1 Π states and the transition dipole moments between them were calculated using the internally contracted multireference configuration interaction (icMRCI) approach. To calculate the accurate rovibrational transition properties of the A1 Π–X1 Σ+ system, we employed the experimental Te of the A1 Π state and the Re of the two states to improve the reliability of the ab initio results. The transition energies, Einstein A coefficients, oscillator strengths, vibrational transition dipole moment matrix elements, and Franck–Condon factors of the rovibrational transitions of the A1 Π–X1 Σ+ system were calculated at the rotational quantum number J ≤ 150 for the lower vibrational levels. The Einstein A coefficients of certain rovibrational transitions are large, suggesting that these transitions are strong and therefore, can be readily measured through spectroscopy. Comparison of the rovibrational transition properties calculated herein with the experimental results indicated an acceptable agreement, suggesting that the obtained results are accurate. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
26. Transition Properties of A3Σ+, B3Π, and C3Δ states of NS+.
- Author
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Sun, S., Gao, Y., and Zhu, Z.
- Abstract
The potential energy curves of the X
1 Σ+ , a3 Σ+ , b3 Π, and c3 Δ states of NS+ and the properties of the transitions between them are reported, which were calculated using the complete active space self–consistent field method, followed by the internally contracted multireference configuration interaction approach with Davidson correction. The radiative lifetimes of the first 16 vibrational levels were 11.3–68.3 μs and 0.18–530.7 ms for the b3 Π and c3 Δ states, respectively; those were 40.9–47.4 ms for the a3 state; those were 22.3–130.5, 11.7–63.5, 22.2–131.7, and 23.8–143.6 μs for the b3 Π2 , b3 Π1 , b3 Π0+ , and b3 Π0– states, respectively; those were 0.1–350.3, 0.2–964.5, and 0.4–2247.1 ms for the c3 Δ1 , c3 Δ2 , and c3 Δ3 states, respectively. The radiative lifetime of the a3 state was extremely long. The spectroscopic parameters and vibrational levels were evaluated and compared with the available experimental and theoretical results. The Franck–Condon factors, band origins, and Einstein A coefficients of all these spontaneous emissions were determined. The b3 Π–a3 Σ+ transition was strong and hence easy to be detected. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
27. Spectroscopic Parameters of 15 Low-Lying Doublet and Quartet Λ-S States as Well as 36 Ω States of VO.
- Author
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Sun, S., Zhou, M., and Zhu, Z.
- Abstract
A large number of experimental transitions between Ω states of VO have been observed. However, almost no theoretical calculations are currently available in the literature, in which the spin-orbit coupling effect on the spectroscopic parameters of VO was computed. In this work, the PECs of X
4 Σ– , A′4 Φ, A4 Π, B4 Π, C4 Σ– , D4 Δ, a2 Σ– , b2 г, c2 Δ, d2 Σ+ , e2 Φ, f2 Π, g2 Π, 22 Φ, and 32 Π states as well as their 36 Ω states were computed through internally contracted multireference configuration interaction approach with Davidson modification. To improve the accuracy of spectroscopic parameters, scalar relativistic and core-valence correlation correlations were included by aug-cc-pwCV5Z-DK and aug-cc-pCV5Z-DK basis sets for V and O, respectively. The spectroscopic parameters of 15 Λ-S and 36 Ω states were evaluated. The c2 Δ, f2 Π, g2 Π, and 32 Π states were found to be inverted with the spin-orbit coupling effect taken into account. The splitting energies between the two neighboring Ω states from the A4 Π–1/2 to A4 Π5/2 states were 34.89, 40.61, and 46.52 cm–1 ; those from the B4 Π–1/2 to B4 Π5/2 states were 61.23, 62.11, and 64.75 cm–1 ; those from the D4 Δ1/2 to D4 Δ7/2 states were 88.16, 104.20, and 107.95 cm–1 , and those from the A′4 Φ3/2 to A′4 Φ9/2 were 192.73, 175.80, and 168.43 cm–1 , which compared well with the available experimental results, indicating that these results achieved high quality. It is expected that these spectroscopic parameters would provide some useful guidelines for future studies. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
28. Testing non-standard neutrino interactions in (anti)-electron neutrino disappearance experiments.
- Author
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Chaves, M. E., de Holanda, P. C., and Peres, O. L. G.
- Subjects
NEUTRINO interactions ,CP violation ,NEUTRINOS ,NEUTRINO oscillation - Abstract
We search for scalar and tensor non-standard interactions using (anti)-electron neutrino disappearance in oscillation data. We found a slight preference for non-zero CP violation, coming from both tensor and scalar interactions. The preference for CP violation is led by Daya Bay low-energy data with a significance that reaches ~ 1.7σ in the global analysis (and ~ 2.1σ when considering only medium baseline reactors data) compared to the standard neutrino oscillation scenario. In some cases, our results indicate that the atmospheric mass squared difference falls outside the range allowed by accelerator long baseline experiments. This suggests the need for further investigation in future work. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. A critical evaluation, challenges, and future perspectives of using artificial intelligence and emerging technologies in smart classrooms.
- Author
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Dimitriadou, Eleni and Lanitis, Andreas
- Subjects
TECHNOLOGICAL innovations ,ARTIFICIAL intelligence ,CLASSROOM environment ,CLASSROOMS ,TECHNOLOGY assessment ,INTELLIGENT tutoring systems - Abstract
The term "Smart Classroom" has evolved over time and nowadays reflects the technological advancements incorporated in educational spaces. The rapid advances in technology, and the need to create more efficient and creative classes that support both in-class and remote activities, have led to the integration of Artificial Intelligence and smart technologies in smart classes. In this paper we discuss the concept of Artificial Intelligence in Education and present a literature review related to smart classroom technology, with an emphasis on emerging technologies such as AI-related technologies. As part of this survey key technologies related to smart classes used for effective class management that enhance the convenience of classroom environments, the use of different types of smart teaching aids during the educational process and the use of automated performance assessment technologies are presented. Apart from discussing a variety of technological accomplishments in each of the aforementioned areas, the role of AI is discussed, allowing the readers to comprehend the importance of AI in key technologies related to smart classes. Furthermore, through a SWOT analysis, the Strengths, Weaknesses, Opportunities, and Threats of adopting AI in smart classes are presented, while the future perspectives and challenges in utilizing AI-based techniques in smart classes are discussed. This survey targets educators and AI professionals so that the former get informed about the potential, and limitations of AI in education, while the latter can get inspiration from the challenges and peculiarities of educational AI-based systems. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
30. Sterile neutrinos: propagation in matter and sensitivity to sterile mass ordering.
- Author
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Chattopadhyay, Dibya S., Devi, Moon Moon, Dighe, Amol, Dutta, Debajyoti, Pramanik, Dipyaman, and Raut, Sushant K.
- Abstract
We analytically calculate the neutrino conversion probability P
μe in the presence of sterile neutrinos, with exact dependence on ∆ m 41 2 and with matter effects explicitly included. Using perturbative expansion in small parameters, the terms involving the small mixing angles θ24 and θ34 can be separated out, with θ34 dependence only arising due to matter effects. We express Pμe in terms of the quantities of the form sin(x)/x, which helps in elucidating its dependence on matter effects and a wide range of ∆ m 41 2 values. Our analytic expressions allow us to predict the effects of the sign of ∆ m 41 2 at a long baseline experiment like DUNE. We numerically calculate the sensitivity of DUNE to the sterile mass ordering and find that this sensitivity can be significant in the range ∣ Δ m 41 2 ∣ ∼ 10 − 4 − 10 − 2 eV2 , for either mass ordering of active neutrinos. The dependence of this sensitivity on the value of ∆ m 41 2 for all mass ordering combinations can be explained by investigating the resonance-like terms appearing due to the interplay between the sterile sector and matter effects. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
31. On optimization of cooperative MIMO for underlaid secrecy Industrial Internet of Things.
- Author
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Wang, Xinyao, Bao, Xuyan, Huang, Yuzhen, Zheng, Zhong, and Fei, Zesong
- Abstract
Copyright of Frontiers of Information Technology & Electronic Engineering is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
32. Characterization of keystone taxa and microbial metabolic potentials in copper tailing soils.
- Author
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Fan, Qiao, Chen, Yeqiang, Xu, Rui, and Guo, Zhaohui
- Subjects
COPPER in soils ,METAL content of soils ,MICROBIAL contamination ,SOIL microbiology ,CARBON fixation ,SOILS ,COPPER - Abstract
Copper mining has caused serious soil contamination and threaten the balance of underground ecosystem. Effects of metal contamination on the soil microbial community assembly and their multifunctionality are still unclear. In this study, the keystone taxa and microbial metabolic potential of soil microorganisms surrounding a typical copper tailing were investigated. Results showed that pH and metal contents of adjacent soil in copper tailing increased, which largely reduced soil microbial communities' diversity. Metal contaminated soils enriched a group of keystone taxa with metal-tolerance such as Bacteroidota (20–54%) and Firmicutes (24–48%), which were distinct from the uncontaminated background soils that dominated by Proteobacteria (19–24%) and Actinobacteria (13–24%). In the contaminated soils, these keystone taxa were identified as Alistipes, Bacteroides, and Faecalibacterium, suggesting their adaptation to the metal-rich environment. Co-occurrence network analysis showed that the microbial community was loosely connected in the metal contaminated soils with a lower number of nodes and links. Co-occurrence networks further revealed that the dynamics of keystone taxa significantly correlated with copper content. Functional gene analysis of soil microorganisms indicated that metal contamination might inhibit important microbial metabolic potentials, such as secondary metabolites biosynthesis, carbon fixation, and nitrogen fixation. Results also found the flexible adaptation strategies of soil microbial communities to metal-rich environments with metal-resistance or bio-transformation, such as efflux (CusB/CusF/CzsB and pcoB/copB) and oxidation (aoxAB). These findings provide insight into the interaction between keystone taxa and soil environment, which is helpful to reveal the microbial metabolic potential and physiological characteristics in tailing contaminated soils. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Radiosensitizing effect of paclitaxel in vivo in a xenotransplanted human squamous cell carcinoma.
- Author
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Hampel, G., Rübe, Ch., and Willich, N.
- Published
- 1995
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- View/download PDF
34. Prebiopsy bpMRI and hematological parameter-based risk scoring model for predicting outcomes in biopsy-naive men with PSA 4–20 ng/mL.
- Author
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Zheng, Yuxin, Li, Wang, Zhang, Yang, Zhang, Chi, Wang, Junqi, and Ge, Peng
- Subjects
DISEASE risk factors ,NOMOGRAPHY (Mathematics) ,PROSTATE-specific antigen ,MACHINE learning ,PROSTATE biopsy ,RECEIVER operating characteristic curves - Abstract
Excessive prostate biopsy is a common problem for clinicians. Although some hematological and bi-parametric magnetic resonance imaging (bpMRI) parameters might help increase the rate of positive prostate biopsies, there is a lack of studies on whether their combination can further improve clinical detection efficiency. We retrospectively enrolled 394 patients with PSA levels of 4–20 ng/mL who underwent prebiopsy bpMRI during 2010–2021. Based on bpMRI and hematological indicators, six models and a nomogram were constructed to predict the outcomes of biopsy. Furthermore, we constructed and evaluated a risk scoring model based on the nomogram. Age, prostate-specific antigen (PSA) density (PSAD), systemic immune-inflammation index, cystatin C level, and the Prostate Imaging Reporting and Data System (PI-RADS) v2.1 score were significant predictors of prostate cancer (PCa) on multivariable logistic regression analyses (P < 0.05) and the five parameters were used to construct the XYFY nomogram. The area under the receiver operating characteristic (ROC) curve (AUC) of the nomogram was 0.916. Based on the nomogram, a risk scoring model (XYFY risk model) was constructed and then we divided the patients into low-(XYFY score: < 95), medium-(XYFY score: 95–150), and, high-risk (XYFY score: > 150) groups. The predictive values for diagnosis of PCa and clinically-significant PCa among the three risk groups were 3.0%(6/201), 41.8%(51/122), 91.5%(65/71); 0.5%(1/201), 19.7%(24/122), 60.6%(43/71), respectively. In conclusion, in this study, we used hematological and bpMRI parameters to establish and internally validate a XYFY risk scoring model for predicting the biopsy outcomes for patients with PSA levels of 4–20 ng/mL and this risk model would support clinical decision-making and reduce excessive biopsies. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. The impact of neutrino-nucleus interaction modeling on new physics searches.
- Author
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Coyle, Nina M., Li, Shirley Weishi, and Machado, Pedro A. N.
- Abstract
Accurate neutrino-nucleus interaction modeling is an essential requirement for the success of the accelerator-based neutrino program. As no satisfactory description of cross sections exists, experiments tune neutrino-nucleus interactions to data to mitigate mis-modeling. In this work, we study how the interplay between near detector tuning and cross section mis-modeling affects new physics searches. We perform a realistic simulation of neutrino events and closely follow NOvA’s tuning, the first published of such procedures in a neutrino experiment. We analyze two illustrative new physics scenarios, sterile neutrinos and light neutrinophilic scalars, presenting the relevant experimental signatures and the sensitivity regions with and without tuning. While the tuning does not wash out sterile neutrino oscillation patterns, cross section mis-modeling can bias the experimental sensitivity. In the case of light neutrinophilic scalars, variations in cross section models completely dominate the sensitivity regardless of any tuning. Our findings reveal the critical need to improve our theoretical understanding of neutrino-nucleus interactions, and to estimate the impact of tuning on new physics searches. We urge neutrino experiments to follow NOvA’s example and publish the details of their tuning procedure, and to develop strategies to more robustly account for cross section uncertainties, which will expand the scope of their physics program. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
36. Damping of neutrino oscillations, decoherence and the lengths of neutrino wave packets.
- Author
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Akhmedov, Evgeny and Smirnov, Alexei Y.
- Abstract
Spatial separation of the wave packets (WPs) of neutrino mass eigenstates leads to decoherence and damping of neutrino oscillations. Damping can also be caused by finite energy resolution of neutrino detectors or, in the case of experiments with radioactive neutrino sources, by finite width of the emitted neutrino line. We study in detail these two types of damping effects using reactor neutrino experiments and experiments with radioactive
51 Cr source as examples. We demonstrate that the effects of decoherence by WP separation can always be incorporated into a modification of the energy resolution function of the detector and so are intimately entangled with it. We estimate for the first time the lengths σx of WPs of reactor neutrinos and neutrinos from a radioactive51 Cr source. The obtained values, σx = (2 × 10−5 − 1.4 × 10−4 ) cm, are at least six orders of magnitude larger than the currently available experimental lower bounds. We conclude that effects of decoherence by WP separation cannot be probed in reactor and radioactive source experiments. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
37. Software Defined 5G and 6G Networks: a Survey.
- Author
-
Long, Qingyue, Chen, Yanliang, Zhang, Haijun, and Lei, Xianfu
- Subjects
SOFTWARE-defined networking ,COMPUTER software security ,COMPUTER software ,WIRELESS channels ,ENERGY consumption ,SCALABILITY - Abstract
The current mobile communications could not satisfy the explosive data requirement of users. This paper reviews the frontier technology of software definition networks (SDN) of 5G and 6G, including system architecture, resource management, mobility management, interference management, challenges, and open issues. First of all, the system architectures of 5G and 6G mobile networks are introduced based on SDN technologies. Then typical SDN-5G/6G application scenarios and key issues are discussed. We also focus on mobility management approaches in mobile networks. Besides, three types of mobility management mechanism in software defined 5G/6G are described and compared. We then summarize the current interference management techniques in wireless cellular networks. Next, we provide a brief survey of interference management method in SDN-5G/6G. Additionally, considering the challenges, we discuss mm-Wave spectrum, un-availability of popular channel model, massive MIMO, low latency and QoE, energy efficiency, scalability, mobility and routing, inter operability, standardization and security for software defined 5G/6G networks. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
38. Matter effects of sterile neutrino in light of renormalization-group equations.
- Author
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Zeng, Shuge and Xu, Fanrong
- Subjects
STERILE neutrinos ,SOLAR neutrinos ,NEUTRINOS ,DIFFERENTIAL equations ,EQUATIONS - Abstract
The renormalization-group equation (RGE) approach to neutrino matter effects is further developed in this work. We derive a complete set of differential equations for effective mixing elements, masses and Jarlskog-like invariants in presence of a light sterile neutrino. The evolutions of mixing elements as well as Jarlskog-like invariants are obtained by numerically solving these differential equations. We calculate terrestrial matter effects in long-baseline (LBL) experiments, taking NOvA, T2K and DUNE as examples. In both three-flavor and four-flavor frameworks, electron-neutrino survival probabilities as well as the day-night asymmetry of solar neutrino are also evaluated as a further examination of the RGE approach. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
39. First-principles study of the electronic and optical properties of HoW impurities in single-layer tungsten disulfide.
- Author
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Khan, M. A. and Leuenberger, Michael N.
- Subjects
OPTICAL properties ,OPTICAL resonance ,TUNGSTEN ,DENSITY functional theory ,SPIN-orbit interactions ,OPTICAL spectra - Abstract
The electronic and optical properties of single-layer (SL) tungsten disulfide (WS 2 ) in the presence of substitutional Holmium impurities (Ho W ) are studied. Although Ho is much larger than W, density functional theory (DFT) including spin-orbit coupling is used to show that Ho:SL WS 2 is stable. The magnetic moment of the Ho impurity is found to be 4.75 μ B using spin-dependent DFT. The optical selection rules identified in the optical spectrum match exactly the optical selection rules derived by means of group theory. The presence of neutral Ho W impurities gives rise to localized impurity states (LIS) with f-orbital character in the band structure. Using the Kubo-Greenwood formula and Kohn-Sham orbitals we obtain atom-like sharp transitions in the in-plane and out-of-plane components of the susceptibility tensor, Im χ ‖ and Im χ ⊥ . The optical resonances are in good agreement with experimental data. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
40. Ultracold neutron storage and transport at the PSI UCN source.
- Author
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Bison, G., Daum, M., Kirch, K., Lauss, B., Ries, D., Schmidt-Wellenburg, P., and Zsigmond, G.
- Subjects
ULTRACOLD neutrons ,MONTE Carlo method ,ULTRACOLD molecules ,PHYSICS experiments ,NEUTRONS ,STORAGE - Abstract
Efficient neutron transport is a key ingredient to the performance of ultracold neutron (UCN) sources, important to meeting the challenges placed by high precision fundamental physics experiments. At the Paul Scherrer Institute's UCN source we have been continuously improving our understanding of the UCN source parameters by performing a series of studies to characterize neutron production and moderation, and UCN production, extraction, and transport efficiency to the beamport. The present study on the absolute UCN transport efficiency completes our previous publications. We report on complementary measurements, namely one on the height-dependent UCN density and a second on the transmission of a calibrated quantity of UCN over a ∼ 16 m long UCN guide section connecting one beamport via the source storage vessel to another beamport. These allow us quantifying and optimizing the performance of the guide system based on extensive Monte Carlo simulations. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
41. Searches for short-baseline electron-neutrino oscillations in the SAGE and BOREXINO experiments involving artificial neutrino sources.
- Author
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Gorbachev, V., Veretenkin, E., Gavrin, V., Dan'shin, S., Ibragimova, T., Kalikhov, A., and Knodel, T.
- Subjects
ELECTRONS ,NEUTRINO oscillation ,NUCLEAR physics experiments ,CHROMIUM ,PARAMETER estimation ,NUCLEAR research - Abstract
The potential of the SAGE and BOREXINO experiments with Cr artificial neutrino sources for searches for and determination of parameters of short-baseline oscillations. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
42. Statistical significance of the sterile-neutrino hypothesis in the context of reactor and gallium data.
- Author
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Berryman, Jeffrey M., Coloma, Pilar, Huber, Patrick, Schwetz, Thomas, and Zhou, Albert
- Subjects
SOLAR neutrinos ,GALLIUM ,STATISTICAL significance ,NEUTRINOS ,MONTE Carlo method ,HYPOTHESIS - Abstract
We evaluate the statistical significance of the 3+1 sterile-neutrino hypothesis using ν
e and ν ¯e disappearance data from reactor, solar and gallium radioactive source experiments. Concerning the latter, we investigate the implications of the recent BEST results. For reactor data we focus on relative measurements independent of flux predictions. For the problem at hand, the usual χ2 -approximation to hypothesis testing based on Wilks' theorem has been shown in the literature to be inaccurate. We therefore present results based on Monte Carlo simulations, and find that this typically reduces the significance by roughly 1 σ with respect to the naïve expectation. We find no significant indication in favor of sterile-neutrino oscillations from reactor data. On the other hand, gallium data (dominated by the BEST result) show more than 5 σ of evidence supporting the sterile-neutrino hypothesis, favoring oscillation parameters in agreement with constraints from reactor data. This explanation is, however, in significant tension (∼ 3 σ) with solar neutrino experiments. In order to assess the robustness of the signal for gallium experiments we present a discussion of the impact of cross-section uncertainties on the results. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
43. A chiral model for sterile neutrino.
- Author
-
Liu, Chun and Reyimuaji, Yakefu
- Abstract
A model, which extends the standard model with a new chiral U(1)′ gauge symmetry sector, for the eV-mass sterile neutrino is constructed. It is basically fixed by anomaly free conditions. The lightness of the sterile neutrino has a natural explanation. As a by product, this model provides a WIMP-like dark matter candidate. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
44. Omeprazole suppresses endothelial calcium response and eNOS Ser1177 phosphorylation in porcine aortic endothelial cells.
- Author
-
Kamiya, Chiaki, Odagiri, Keiichi, Hakamata, Akio, Sakurada, Ryugo, Inui, Naoki, and Watanabe, Hiroshi
- Abstract
Background: Although high doses of proton pump inhibitors can elicit an anticancer effect, this strategy may impair vascular biology. In particular, their effects on endothelial Ca
2+ signaling and production of endothelium-derived relaxing factor (EDRF) are unknown. To this end, we investigated the effects of high dosages of omeprazole on endothelial Ca2+ responses and EDRF production in primary cultured porcine aortic endothelial cells. Methods and results: Omeprazole (10–1000 μM) suppressed both bradykinin (BK)- and thapsigargin-induced endothelial Ca2+ response in a dose-dependent manner. Furthermore, omeprazole slightly attenuated Ca2+ mobilization from the endoplasmic reticulum, whereas no inhibitory effects on endoplasmic reticulum Ca2+ -ATPase were observed. Omeprazole decreased BK-induced phosphorylation of endothelial nitric oxide synthase (eNOS) at Ser1177 and tended to decrease BK-induced nitric oxide production. Production of prostaglandin I2 metabolites, especially 6-keto-prostaglandin 1α, also tended to be reduced by omeprazole. Conclusion: Our results are the first to indicate that high doses of omeprazole may suppress both store-operated Ca2+ channels and partially the G protein-coupled receptor/phospholipase C/inositol 1,4,5-triphosphate pathway, and decreased BK-induced, Ca2+ -dependent phosphorylation of eNOS(Ser1177). Thus, high dosages of omeprazole impaired EDRF production by attenuating intracellular Ca2+ signaling. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
45. Status report on the GALLEX experiment.
- Author
-
Anselmann, P., Hampel, W., Heusser, G., Kiko, J., Kirsten, T., Pernicka, E., Plaga, R., Rönn, U., Sann, M., Schlosser, C., Wink, R., Wojcik, M., Ammon, R., Ebert, K., Fritsch, T., Hellriegel, K., Henrich, E., Stieglitz, L., Weyrich, F., and Balata, M.
- Abstract
The GALLEX collaboration is performing an experiment for the detection of neutrinos coming principally from the p-p fusion reaction in the Sun, via the reaction v +Ga →Ge + e. The experiment is running in the Gran Sasso Underground Laboratory of INFN, using as a target 30.3 tons of gallium in the form of 8.13 molar aqueous GaCl solution. A report is given of the status of GALLEX after the end of the operations devoted to the removal from the solution of the cosmogenically formed Ge isotopes, completed in the middle of 1991. The experiment is now collecting data on solar neutrinos and the data analysis is in progress. Preliminary results concerning the first year of measurement are presented. [ABSTRACT FROM AUTHOR]
- Published
- 1992
- Full Text
- View/download PDF
46. Challenge to anomalous phenomena in solar neutrino.
- Author
-
Ahn, Y. H.
- Subjects
SOLAR neutrinos ,STERILE neutrinos ,NEUTRINOS ,ANTINEUTRINOS - Abstract
We suggest a would-be solution to the solar neutrino tension why solar neutrinos appear to mix differently from reactor antineutrinos, in theoretical respect. To do that, based on an extended theory with light sterile neutrinos added we derive a general transition probability of neutrinos born with one flavor tuning into a different flavor. Three new mass-squared differences are augmented in the extended theory: Δ m ABL 2 ≲ O 10 − 11 eV
2 optimized at astronomical-scale baseline (ABL) oscillation experiments and one Δ m SBL 2 ≲ O 1 eV2 optimized at reactor short-baseline (SBL) oscillation experiments. With a so-called composite matter effect that causes a neutrino flavor change via the effects of sinusoidal oscillation including the Mikheyev-Smirnov-Wolfenstein matter effect, we find that the value of ∆m2 measured from reactor antineutrino experiments can be fitted with that from the8 B solar neutrino experiments for roughly Δ m 1 2 ≲ 10 − 13 eV2 and Δ m 2 2 ≃ O 10 − 11 eV2 . Nonetheless, we find that the current data (solar neutrino alone) is not precise enough to test the proposed scenario. Future precise measurements of8 B and pep solar neutrinos may confirm and/or improve the value of Δ m 2 2 . [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
47. Ultra-reliable and low-latency communications: applications, opportunities and challenges.
- Author
-
Feng, Daquan, Lai, Lifeng, Luo, Jingjing, Zhong, Yi, Zheng, Canjian, and Ying, Kai
- Abstract
In the upcoming 5G and beyond systems, ultra-reliable and low latency communication (URLLC) has been considered as the key enabler to support diverse mission-critical services, such as industrial automation, remote healthcare, and intelligent transportation. However, the two stringent requirements of URLLC: extremely low latency and ultra-strict reliability have posed great challenges in system designing. In this article, the basic concepts and the potential applications of URLLC are first introduced. Then, the state-of-the-art research of URLLC in the physical layer, link layer and the network layer are overviewed. In addition, some potential research topics and challenges are also identified. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
48. 2020 global reassessment of the neutrino oscillation picture.
- Author
-
de Salas, P. F., Forero, D. V., Gariazzo, S., Martínez-Miravé, P., Mena, O., Ternes, C. A., Tórtola, M., and Valle, J. W. F.
- Abstract
We present an updated global fit of neutrino oscillation data in the simplest three-neutrino framework. In the present study we include up-to-date analyses from a number of experiments. Concerning the atmospheric and solar sectors, besides the data considered previously, we give updated analyses of IceCube DeepCore and Sudbury Neutrino Observatory data, respectively. We have also included the latest electron antineutrino data collected by the Daya Bay and RENO reactor experiments, and the long-baseline T2K and NOνA measurements, as reported in the Neutrino 2020 conference. All in all, these new analyses result in more accurate measurements of θ
13 , θ12 , Δ m 21 2 and Δ m 31 2 . The best fit value for the atmospheric angle θ23 lies in the second octant, but first octant solutions remain allowed at ∼ 2.4σ. Regarding CP violation measurements, the preferred value of δ we obtain is 1.08π (1.58π) for normal (inverted) neutrino mass ordering. The global analysis still prefers normal neutrino mass ordering with 2.5σ statistical significance. This preference is milder than the one found in previous global analyses. These new results should be regarded as robust due to the agreement found between our Bayesian and frequentist approaches. Taking into account only oscillation data, there is a weak/moderate preference for the normal neutrino mass ordering of 2.00σ. While adding neutrinoless double beta decay from the latest Gerda, CUORE and KamLAND-Zen results barely modifies this picture, cosmological measurements raise the preference to 2.68σ within a conservative approach. A more aggressive data set combination of cosmological observations leads to a similar preference for normal with respect to inverted mass ordering, namely 2.70σ. This very same cosmological data set provides 2σ upper limits on the total neutrino mass corresponding to Σmν < 0.12 (0.15) eV in the normal (inverted) neutrino mass ordering scenario. The bounds on the neutrino mixing parameters and masses presented in this up-to-date global fit analysis include all currently available neutrino physics inputs. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
49. Qualitative analysis of zolpidem and its metabolites M-1 to M-4 in human blood and urine using liquid chromatography–tandem mass spectrometry.
- Author
-
Yamaguchi, Koji, Miyaguchi, Hajime, Hirakawa, Keiko, Ohno, Youkichi, and Kanawaku, Yoshimasa
- Abstract
Purpose: The aim of this study was to develop the method for the qualitative analysis of zolpidem and its metabolites M-1 to M-4 using liquid chromatography–tandem mass spectrometry (LC–MS/MS) in human blood and urine. Methods: To obtain analytical standards, a method for synthesizing zolpidem metabolites M-1 to M-4 was developed. A combination of a copper-catalyzed three-component coupling reaction and pyrrolidine-catalyzed imine formation was adopted to synthesize the methyl esters of M-1 (M-1-Me) and M-2 (M-2-Me), which were hydrolyzed to afford M-1 and M-2, respectively. M-3 and M-4 were also synthesized. The LC–MS/MS conditions were optimized using authentic standards. M-1 to M-4 were analyzed in human blood and urine. Results: M-1 to M-4 were successfully synthesized. The mass spectra of M-1 and M-2 were almost identical, but their peaks were chromatographically separated using a octadecyl silica column. Likewise, mass spectra of M-3 and M-4 were similar, but their peaks were chromatographically separated. The peak intensities of the metabolites in human blood and urine were M-1 > M-2, and M-4 > M-3; M-3 was detected only in urine. The presence of other hydroxyzolpidems was also revealed. Conclusions: Chromatographic separation of M-1 and M-2 and that of M-4 and other hydroxyzolpidems is necessary to analyze zolpidem metabolites in biological matrices because their mass spectra are quite similar. This study is the first to analyze zolpidem and M-1 to M-4 simultaneously using LC–MS/MS, which can provide more compelling evidence of zolpidem intake. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
50. A self-organizing base station sleeping and user association strategy for dense cellular networks.
- Author
-
Post, Bart, Borst, Sem, and van den Berg, Hans
- Subjects
ENERGY consumption ,INFORMATION needs - Abstract
Due to the rising concerns of energy consumption in wireless networks, base station (BS) sleeping strategies were introduced to save energy in low traffic scenarios. In this paper we analyse a weighted trade-off between energy consumption and user-perceived performance in dense cellular networks. We present an optimization problem representing this trade-off and derive properties of its optimal solutions. Using these properties we design a self-organizing strategy that dynamically (online) makes load-aware user association and BS operation decisions. Our strategy is self-organizing in the sense that it does not need any information or optimization beforehand, it simply relies on real-time load measurements at the BSs and user-reported SINR values. We furthermore present extensive simulation results, demonstrating the effectiveness of our self-organizing strategy and the impact of increased energy consumption on the user-perceived performance. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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