Complete One-loop Renormalization-group Equations in the Seesaw Effective Field Theories

In this paper, we derive the complete set of one-loop renormalization-group equations (RGEs) for the operators up to dimension-six (dim-6) in the seesaw effective field theories (SEFTs). Two kinds of contributions to those RGEs are identified, one from double insertions of the dimension-five (dim-5) Weinberg operator and the other from single insertions of the tree-level dim-6 operators in the SEFTs. A number of new results are presented. First, as the dim-5 Weinberg operator is unique in the standard model effective field theory (SMEFT), its contributions to the RGEs for the SEFTs are equally applicable to the SMEFT. We find the full contributions from the Weinberg operator to one-loop RGEs in the SMEFT, correcting the results existing in previous works, and confirm that those from dim-6 operators are consistent with the results in the literature. Second, in the type-I SEFT, we give the explicit expressions of the RGEs of all the physical parameters involved in the charged- and neutral-current interactions of leptons. Third, the RGEs are numerically solved to illustrate the running behaviors of the non-unitary parameters, mixing angles and CP-violating phases in the non-unitary leptonic flavor mixing matrix. Together with the one-loop matching results of the dim-5 and dim-6 operators and their Wilson coefficients, the present work has established a self-consistent framework up to dim-6 to investigate low-energy phenomena of three types of seesaw models at the one-loop level.Comment: 54 pages, 14 figure

Invisible Neutrino Decays as Origin of TeV Gamma Rays from GRB221009A

Recently, the LHAASO collaboration has observed the gamma rays of energies up to ten TeV from the gamma-ray burst GRB221009A, which has stimulated the community of astronomy, particle physics and astrophysics to propose various possible interpretations. In this paper, we put forward a viable scenario that neutrinos are produced together with TeV photons in the gamma-ray burst and gradually decay into the axion-like particles, which are then converted into gamma rays in the galactic magnetic fields. In such a scenario, the tension between previous axion-like particle interpretations and the existing observational constraints on the relevant coupling constant and mass can be relaxed.Comment: 25 pages, 7 figures, more discussions and references added, version accepted by JCA

Investigation of the Free-Fall Dynamic Behavior of a Rectangular Wing with Variable Center of Mass Location and Variable Moment of Inertia

© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).In recent years, the air-drop launch technology of near-space UAVs has attracted much attention. Between downfall from the carrier and the flight control system’s initiation, the UAV presents free-fall movement. This free-fall process is very important for the control effect of the flight control system and is also crucial for the safety of the UAV and the carrier. Focus is required on two important dynamic parameters of the UAV: the moment of inertia and the center of mass position. In this paper, we used a quasi-steady model proposed by predecessors to address the flat-plate falling problem with modifications to describe the freely falling motion of the wing. Computational fluid dynamics (CFD) were used to simulate the free-fall movement of the wing with various parameters, and the wing release behavior was analyzed to check the quasi-steady model. Research shows that the movement characteristics of the falling wing are mostly reflected in the longitudinal plane, and the developed quasi-steady analytical model can more accurately describe the dynamic behavior of free-fall to some extent. By using CFD methods, we further investigated the aerodynamic performance of the free-fall wing. The results show that the wing mainly presents tumbling and fluttering motion. Changing the moment of inertia around the tumbling axis changes the tumbling frequency and the time point as the wing enters tumbling. In contrast, changing the position of the center of mass significantly changes the form of falling and makes the free-fall motion more complex. Therefore, it is necessary to carefully configure the center of mass in the UAV design process.Peer reviewe

Communication-Efficient Cluster Federated Learning in Large-scale Peer-to-Peer Networks

A traditional federated learning (FL) allows clients to collaboratively train a global model under the coordination of a central server, which sparks great interests in exploiting the private data distributed on clients. However, once the central server suffers from a single point of failure, it will lead to system crash. In addition, FL usually involves a large number of clients, which requires expensive communication costs. These challenges inspire a communication-efficient design of decentralized FL. In this paper, we propose an efficient and privacy-preserving global model training protocol in the context of FL in large-scale peer-to-peer networks, CFL. The proposed CFL protocol aggregates local contributions hierarchically by a cluster-based aggregation mode, as well as a leverged authenticated encryption scheme to ensure the security communication, whose key is distributed by a modified secure communication key establishment protocol. Theoretical analyses show that CFL guarantees the privacy of local model update parameters, as well as integrity and authenticity under the widespread internal semi-honest and external malicious threat models. In particular, the proposed key revocation based on public voting can effectively defense against external adversaries hijacking honest participants to ensure the confidentiality of the communication keys. Moreover, the modified secure communication key establishment protocol indeed achieves high network connectivity probability to ensure transmission security of the system

Facile synthesis of CdS nanocrystals using thioglycolic acid as a sulfur source and stabilizer in aqueous solution

A novel method has been developed for the synthesis of CdS nanocrystals (NCs) using thioglycolic acid (TGA) as a sulfur source and stabilizer with the presence of hydrogen peroxide in an aqueous medium. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The results indicate that the product was of zinc-blend crystal structure in a sphere-like shape. The room-temperature luminescence spectra revealed that the emission peak of CdS NCs prepared in relatively short refluxing times (10-120 min) could be tuned from 518 nm to 610 nm, and the photoluminescence quantum yield of the as-prepared CdS NCs could reach as high as 12.6%. In addition, the mechanism of the CdS nanocrystals formation was preliminarily discussed.KEY WORDS: Chemical synthesis, CdS, Nanostructures, Optical properties, Photoluminescence spectroscopy Bull. Chem. Soc. Ethiop. 2011, 25(3), 393-398

Numerical Analysis of Reinforced Concrete Piles under Blast Loads

Pile foundations are commonly used as foundation systems for high-rise buildings and bridges. This paper uses a fully coupled three dimensional numerical modelling procedure to study the performance of pile foundations subjected to ground shocks induced by surface explosions. The comprehensive numerical model includes the pile, surrounding soil, air and the explosive. Appropriate material models are incorporated and dynamic non-linear analysis is carried out using finite element techniques.  The soil in which the pile is buried could influence the blast performance of the pile. A parametric study is hence carried out to evaluate the effects of soil properties of density, friction angle, cohesion and Poisson’s ratio on the blast performance of the pile. It is found that density and cohesion of soil have significant effects on the deflection of the pile under blast loading. Poisson’s ratio has some effect, but effect of the soil friction angle is not very significant. The findings of this study will serve as a benchmark reference for future analysis and design of pile foundations to blast loading

Microencapsulation of paraffin with poly (urea methacrylate) shell for solar water heater

Previous research has demonstred that microencapsulated phase change materials (MEPCMs) could significantly increase the energy storage density of solar thermal energy storage (TES) systems. Compared with traditional phase change materials (PCMs), MEPCMs have many advantages since they can limit their exposure to the surrounding environment, enlarge the heat transfer area, and maintain the volume as the phase change occurs. In this study, a new MEPCM for solar TES systems is developed by encapsulation of paraffin wax with poly (urea formaldehyde) (PUF). The experimental results revealed that agglomeration of MEPCM particles occurred during the encapsulation process which affected the uniformity of the particle size distribution profile when sodium dodecyl sulfate was used as an emulsifier. The differential scanning calorimetric (DSC) analysis results showed that the melting temperatures were slightly increased by 0.14-0.72 ◦C after encapsulation. A thermogravimetric (TG) test showed that the sample weight decreased while the weight loss starting temperature was slightly increased after encapsulation. Overall, the sample UF-2, fabricated with the binary emulsifiers of Brij 35 and Brij 30 and 5% nucleating agent, resulted in good particle dispersion and shell integrity, higher core material content and encapsulation efficiency, as well as improved thermal stability