RustHorn: CHC-based Verification for Rust Programs (full version)

Reduction to the satisfiability problem for constrained Horn clauses (CHCs) is a widely studied approach to automated program verification. The current CHC-based methods for pointer-manipulating programs, however, are not very scalable. This paper proposes a novel translation of pointer-manipulating Rust programs into CHCs, which clears away pointers and memories by leveraging ownership. We formalize the translation for a simplified core of Rust and prove its correctness. We have implemented a prototype verifier for a subset of Rust and confirmed the effectiveness of our method.Comment: Full version of the same-titled paper in ESOP202

VOC in printers and its elimination by means of thermally activated oxide semiconductors (TASC)

VOCs (volatile organic compounds) arising from fusers in printers, solvent inks in inkjet printers, or wet POD systems cause environmental problems at present. Therefore, efficient elimination technologies are in high demand. In this paper, we will present our novel VOC elimination system based upon thermally activated semiconductors (TASC) characterized by compact, lightweight, and low costs. Because of these appealing features, this system can easily be integrated into office printers or wet POD systems. The TASC technology dates back to our accidental finding that the semiconductor exhibits significant oxidative effects when heated at 350-500°C ; whereas quite inactive at room temperature. The present phenomenon has been applied to the complete decomposition of VOCs. The destruction mechanism is composed of the following three steps : 1. oxidation, i.e. creation of radicals, 2. radical splitting, i. e. fragmentation of the giant molecule, and 3. reaction with oxygen, i. e. complete combustion into H2O and CO2.ArticleJournal of the Imaging Society of Japan. 53(1):28-34 (2014)journal articl

Effect of Co Impurities on Superconductivity of FeSe0.4Te0.6 single crystals

The effect of Co doping on supercoductivity of FeSe$_{0.4}$Te$_{0.6}$ single crystals is investigated. The superconducting transition temperature decreases linearly for Co doping with the rate -0.75 K/(Co %). On the other hand, the residual resistivity increase is less than 50 $/mu/Omega$cm for 4 % Co doping. These data are consistent with the sign changing interband scattering mechanism of superconductivity ($s_/pm$ symmetry).Comment: 10 pages, 6 figure

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Prediction of grain boundary chemistry in multicomponent alloys

Hillert’s grain-boundary-phase (GBP) model is employed for predicting grain boundary (GB) chemistry in multicomponent alloys. The GB is approximated as a thin layer of a homogeneous phase with a constant thickness and its own Gibbs energy. The GB composition is computed to minimize the Gibbs energy of the mixture of a grain phase and the GBP; the Gibbs energy of liquid phase is assigned to that of the GBP. The calculation of phase diagram (CALPHAD) databases are employed to calculate the Gibbs energy of a phase of interest as a function of composition and temperature. To verify the calculation results’ validity, the predicted GB chemistry was compared with experimental data from previous research for nickel-based superalloys, an austenitic stainless steel, and a high-entropy alloy. It is demonstrated that the method combining Hillert’s GBP model and CALPHAD databases is effective for predicting the equilibrium solute segregation to stationary random high-angle GBs in multicomponent alloys, enabling the advanced compositional design of materials for GB segregation engineering