56016 research outputs found
Sort by
Optimal Binary Linear Complementary Pairs of Codes
No full textA pair of linear codes (C, D) of length n over F-q is called a linear complementary pair (LCP) if their direct sum yields the full space F-q(n). By a result of Carlet et al. (2019), the best security parameters of binary LCPs of codes are left open. Motivated by this, we study binary LCPs of codes. We describe a sufficient condition for binary LCPs of codes which are not optimal. We carry out an exhaustive search to determine the best security parameters for binary LCPs of codes up to length 18. We also obtain results on optimal binary LCPs of codes for infinitely many parameters. For any k >= 2 and length n congruent to 0 or 1 mod (2(k) - 1), we prove that binary [n, k] LCPs of codes are optimal. Binary LCPs of codes of dimensions 2, 3, and 4 are also optimal for all lengths except for two instances, when (n, k) = (4, 3) and (8, 4). We provide explicit constructions of these infinite families of optimal LCPs. Our results also indicate that many security parameters coming from binary LCPs of codes exceed those from binary LCD codes by 1 or 2
Genome-wide analyses of early-onset acute myocardial infarction identify 29 novel loci by whole genome sequencing
No full textEarly-onset acute myocardial infarction (AMI) may have a higher genetic predisposition than late-onset AMI. The present study aimed to identify and characterize germline variants that affect early-onset AMI using whole-genome sequencing (WGS). We performed a genome-wide association study based on the WGS of 1239 Koreans, including 596 early-onset AMI patients and 643 healthy individuals. Patients with AMI who underwent percutaneous coronary intervention (PCI) caused by atherothrombotic occlusive lesions were included in the study. A total of 29 novel loci were found to be associated with early-onset AMI. These loci are involved in thrombosis, fibrinolysis, inflammation, and lipid metabolism. One of the associated single nucleotide variants (SNVs), rs1614576, located upstream of PRKCB, is known to be associated with thrombus formation. Additionally, the results revealed a novel locus, rs78631167, located upstream of PLAUR which plays a critical role in regulating plasminogen activation and is related to fibrinolysis. The association between early-onset AMI and rs9357455, which is located upstream of PHACTR1 and regulates inflammation in AMI, was found. Moreover, we identified a lipid metabolism related genetic risk locus, rs5072, in the APOA1-AS gene. This study provides new evidence supporting the genetic association between early-onset AMI and thrombosis and fibrinolysis, as well as inflammation and lipid metabolism, by analyzing the whole-genome of 596 patients with early-onset AMI who have been treated with PCI. Our findings highlight potential genetic markers for the prediction and management of AMI, as well as for understanding the etiology of AMI
Phase Transformation of Colloidal Cs3Cu2Cl5 Nanocrystals to CsMCl (M = Zn, Bi, Cd) by Cation Exchange and Their Thermodynamic Study by Density Functional Theory Calculations
No full textWe present the phase transformation from colloidal Cs3Cu2Cl5 nanocrystals to CsMCl (M = Zn, Bi, Cd) by cation exchange reaction. Cs2ZnCl4, Cs3BiCl6, and CsCdCl3 were successfully synthesized, and the feasibility of phase transformations was demonstrated using density functional theory calculations, which revealed the high thermodynamic stability of the three structures. The results indicate that these structures can be synthetically prepared. The difference in reactivity between Zn, Bi, and Cd cations, which was verified by changing the reaction temperatures, was demonstrated using chemical softness calculations considering the interactions between Cl- and three cations. Additionally, for each cation exchange reaction, thermodynamic stability, estimated in terms of the formation energy, contributed to reactivity. The Cs2ZnCl4 structure required the mildest reaction condition (i.e., 110 degrees C). As a reverse reaction, Cu cations were added to solutions of Cs2ZnCl4, Cs3BiCl6, and CsCdCl3, and CsCu2Cl3 was obtained instead of Cs3Cu2Cl5. The mechanism was not cation exchange, and transmission electron microscopy data showed that nanoparticles were used as precursors for forming CsCu2Cl3 particles
Fabrication of THz corrugated wakefield structure and its high power test
No full textWe present overall process for developing terahertz (THz) corrugated structure and its beam-based measurement results. 0.2-THz corrugated structures were fabricated by die stamping method as the first step demonstration towards GW THz radiation source and GV/m THz wakefield accelerator. 150-?? m thick disks were produced from an OFHC (C10100) foil by stamping. Two types of disks were stacked alternately to form 46 mm structure with ??? 170 corrugations. Custom assembly was designed to provide diffusion bonding with a high precision alignment of disks. The compliance of the fabricated structure have been verified through beam-based wakefield measurement at Argonne Wakefield Accelerator Facility. Both measured longitudinal and transverse wakefield showed good agreement with simulated wakefields. Measured peak gradients, 9.4 MV/m/nC for a long single bunch and 35.4 MV/m/nC for a four bunch trains, showed good agreement with the simulation
Capturing the hole states of oxygen
No full textOxygen redox provides an opportunity to realize the high-energy potential of battery cathodes, but the formation of molecular O2 from the oxidation of oxide ions significantly reduces the cycling stability. Now, the nature of electron-holes on oxide ions is reported, providing insights into realizing a truly reversible oxygen???redox cathode
The role of transient plasma photonic structures in plasma-based amplifiers
No full textHigh power short pulse lasers are technologically reaching a limit in term of amplification due to the material damage threshold of amplifying media. The authors conduct experiments and numerical simulations to show the possibility of benefiting from transient plasma structures generated from counter propagating pump and seed pulses to amplify high power lasers. High power lasers have become useful scientific tools, but their large size is determined by their low damage-threshold optical media. A more robust and compact medium for amplifying and manipulating intense laser pulses is plasma. Here we demonstrate, experimentally and through simulations, that few-millijoule, ultra-short seed pulses interacting with 3.5-J counter-propagating pump pulses in plasma, stimulate back-scattering of nearly 100 mJ pump energy with high intrinsic efficiency, when detuned from Raman resonance. This is due to scattering off a plasma Bragg grating formed by ballistically evolving ions. Electrons are bunched by the ponderomotive force of the beat-wave, which produces space-charge fields that impart phase correlated momenta to ions. They inertially evolve into a volume Bragg grating that backscatters a segment of the pump pulse. This, ultra-compact, two-step, inertial bunching mechanism can be used to manipulate and compress intense laser pulses. We also observe stimulated Compton (kinetic) and Raman backscattering
Revealing the Enhanced Thermoelectric Properties of Controllably Doped Donor-Acceptor Copolymer: The Impact of Regioregularity
No full textAlbeit considerable attention to the fast-developing organic thermoelectric (OTE) materials due to their flexibility and non-toxic features, it is still challenging to design an OTE polymer with superior thermoelectric properties. In this work, two "isomorphic" donor-acceptor (D-A) conjugated polymers are studied as the semiconductor in OTE devices, revealing for the first time the internal mechanism of regioregularity on thermoelectric performances in D-A type polymers. A higher molecular structure regularity can lead to higher crystalline order and mobility, higher doping efficiency, order of energy state, and thermoelectric (TE) performance. As a result, the regioregular P2F exhibits a maximum power factor (PF) of up to 113.27 mu W m(-1) K-2, more than three times that of the regiorandom PRF (35.35 mu W m(-1) K-2). However, the regular backbone also implies lower miscibility with a dopant, negatively affecting TE performance. Therefore, the trade-off between doping efficiency and miscibility plays a vital role in OTE materials, and this work sheds light on the molecular design strategy of OTE polymers with state-of-the-art performances
Growth of Boron Nitride Nanotube Over Al-Based Active Catalyst and its Application in Thermal Management
No full textThe effective identification of the active catalytic phase is essential to elucidate the growth mechanism of boron nitride nanotubes (BNNTs) and realize their controllable and scalable synthesis. However, owing to the complexity of chemical reactions during BNNT growth via chemical vapor deposition (CVD) and the lack of techniques for in situ characterization at high temperatures (1100-1300 degrees C), identifying the true catalyst during BNNT growth is challenging. Herein, an aluminum (Al)-based active catalyst for BNNT growth via CVD is investigated. The initial Al2O3 nanoparticle catalyst precursor is transformed into an Al-B phase prior to BNNT growth. Based on our density functional theory-based molecular dynamic simulations of BNNT nucleation, AlBx (x = 1.5 to 2) shows catalytic activity for the formation of BN chains and BN six-membered rings. Confirmatory experiments demonstrate that AlB2 is the active Al-based catalyst during BNNT growth. A nanocomposite is prepared from cellulose nanocrystal, and purified BNNTs exhibited a high in-plane thermal conductivity of 13.33 W m(-1) K-1 at 20 wt% BNNTs. A further application for light-emitting diode chip cooling demonstrates excellent heat-dissipation performance of the nanocomposite film. Thus, this study can guide the controllable synthesis of high-quality BNNTs and facilitate their use in thermal interface materials
Boosting Algorithm to handle Unbalanced Classification of PM2.5 Concentration Levels by Observing Meteorological Parameters in Jakarta-Indonesia using AdaBoost, XGBoost, CatBoost, and LightGBM
No full textAir quality conditions are now more severe in the Jakarta area that is among the world???s top eight worst cities according to the 2022 Air Quality Index (AQI) report. In particular, the data from the Meteorological, Climatological, and Geophysical Agency (BMKG) of the Republic of Indonesia, the latest outcomes in air quality conditions in Jakarta and surrounding areas, says that PM2.5 concentrations have increased and peaked at 148 ??g/m3 in 2022. While a classification system for this pollution is necessary and critical, the observation of PM2.5 concentrations measured through the BMKG Kemayoran station, Jakarta, turns out to be identified as an unbalanced data class. Thus, in this work, we perform boosting algorithm supervised learning to handle such an unbalanced classification toward PM2.5 concentration levels by observing meteorological patterns in Jakarta during 1 January 2015 to 7 July 2022. The boosting algorithms considered in this research include Adaptive Boosting (AdaBoost), Extreme Gradient Boosting (XGBoost), Categorical Boosting (CatBoost), and Light Gradient Boosting Machine (LightGBM). Our simulations have proven that boosting classification can significantly reduce bias in combination with variance reduction with unbalanced within-class coefficients, with the classification of PM2.5 class values: good 62%, moderate 34%, and unhealthy 59%, respectively
3D Printable Self-Adhesive and Self-Healing Ionotronic Hydrogels for Wearable Healthcare Devices
No full textIonotronic hydrogels have attracted significant attention in emerging fields such as wearable devices, flexible electronics, and energy devices. To date, the design of multifunctional ionotronic hydrogels with strong processability, and high conductivity are key requirements for future wearable devices. Herein, we report the rational design and facile synthesis of 3D printable, self-adhesive, self-healing, and conductive ionotronic hydrogels based on the synergistic dual reversible interactions of poly(vinyl alcohol), borax, pectin, and tannic acid. Multifunctional ionotronic hydrogels exhibit strong adhesion to various substrates with different roughness and chemical components, including porcine skin, glass, nitrile gloves, and plastics (normal adhesion strength of 55 kPa on the skin). In addition, the ionotronic hydrogels exhibit intrinsic ionic conductivity imparting strainsensing properties with a gauge factor of 2.5 up to a wide detection range of approximately 2000%, as well as improved self-healing behavior. Based on these multifunctional properties, we further demonstrate the use of ionotronic hydrogels in the 3D printing process for implementing complex patterns as wearable strain sensors for human motion detection. This study is expected to provide a new avenue for the design of multifunctional ionotronic hydrogels, enabling their potential applications in wearable healthcare devices