Publications by authors named "Byungkyu Ahn"

Quantum secure direct communication (QSDC) can guarantee security using the characteristics of quantum mechanics even when a message is directly transmitted through a quantum channel without using a secret key. However, the transmission rate of the QSDC is limited by the dead time of a single photon detector (SPD) as well as channel loss over the distance. To overcome this limited transmission rate, we propose a high-dimensional single photon-based QSDC protocol that applies two optical degrees of freedom: time and phase state.

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The implementation of vehicle electrification and autonomous driving technologies has recently emphasized the importance of abrasion resistance and fuel efficiency of truck bus radial (TBR) tire treads that undergo high loads and long driving times. In this study, a functionalized liquid butadiene rubber (F-LqBR) was introduced to replace the treated distillate aromatic extracted (TDAE) oil as a way to improve abrasion resistance and fuel efficiency in the TBR tire tread compound and to solve the oil migration. First, radical polymerization was used to synthesize nonfunctionalized LqBR (N-LqBR) and amino-LqBR with an amine group at the chain ends.

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Recently, research conducted on tread compounds with liquid butadiene rubber (LqBR) have been conducted in the tire industry. In particular, the introduction of functional groups into LqBRs is expected to lower hysteresis loss caused by the free chain ends of LqBR. To study this, LqBRs with functional groups at different positions were synthesized.

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The demand for truck-bus radial (TBR) tires with enhanced fuel efficiency has grown in recent years. Many studies have investigated silica-filled natural rubber (NR) compounds to address these needs. However, silica-filled compounds offer inferior abrasion resistance compared to carbon black-filled compounds.

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Liquid butadiene rubber (LqBR) which used as a processing aid play a vital role in the manufacturing of high-performance tire tread compounds. However, the studies on the effect of molecular weight, microstructure, and functionalization of LqBR on the properties of compounds are still insufficient. In this study, non-functionalized and center-functionalized liquid butadiene rubbers (N-LqBR and C-LqBR modified with ethoxysilyl group, respectively) were synthesized with low vinyl content and different molecular weights using anionic polymerization.

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It is believed that the generation of odorous materials in manure-slurry pits during the storage can be reduced by recirculating aerobically treated liquid fertilizer (ATLF) to a manure-pit recharge system (PRS). However, the biological mechanisms for reduction of those problematic compounds remain poorly understood. In this study, the links between microbial evolution and changes in chemical composition and odorous compounds were analyzed where swine-manure slurry was stored in a full-scale PRS.

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The tire industry has shown an increasing demand for the reduction in rolling resistance. Efforts have been made to improve the viscoelastic properties of tire compounds and reduce the weight of tires through optimization of the vulcanizate structure, which has become extremely complex. In this study, vulcanizates using carbon black and silica as binary fillers were prepared at various curing temperatures.

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When designing rubber compounds for high-performance tires, increasing the silica content can improve the wet traction performance but decreases the fuel efficiency. This trade-off relation makes it difficult to improve the two factors simultaneously. One approach is the development of silica wet masterbatch (WMB) technology for producing compounds containing a high silica content with good dispersion.

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Background/aims: Bronchiectasis is aggravated by gastroesophageal reflux disease (GERD) owing to micro aspiration. Some researchers note the effect of antireflux surgery in bronchiectasis with GERD. However, few have investigated the effects of medical antireflux therapy.

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Background/aims: Eosinophilic esophagitis (EoE) is a chronic, immune/antigen-mediated esophageal disease, with eosinophilic infiltration limited to the esophagus. A minority of EoE patients respond well to proton pump inhibitor (PPI) therapy alone, and that condition is labelled PPI-responsive esophageal eosinophilia (PPI-REE). The prevalence of PPI-REE among EoE cases is unknown.

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