Carbon fusion is important to understand the late stages in the evolution of a massive star. Astronomically interesting energy ranges for the 12C+12C reactions have been, however, poorly constrained by experiments. Theoretical studies on stellar evolution have relied on reaction rates that are extrapolated from those measured in higher energies. In this work, we update the carbon fusion reaction rates by fitting the astrophysical S-factor data obtained from direct measurements based on the Fowler, Caughlan, & Zimmerman (1975) formula. We examine the evolution of a 20M⊙ star with the updated 12C+12C reaction rates performing simulations with the MESA (Modules for Experiments for Stellar Astrophysics) code. Between 0.5 and 1 GK, the updated reaction rates are 0.35 to 0.5 times less than the rates suggested by Caughlan & Fowler (1988). The updated rates result in the increase of core temperature by about 7% and of the neutrino cooling by about a factor of three. Moreover, the carbon-burning lifetime is reduced by a factor of 2.7. The updated carbon fusion reaction rates lead to some changes in the details of the stellar evolution model, their impact seems relatively minor compared to other uncertain physical factors like convection, overshooting, rotation, and mass-loss history. The astrophysical S-factor measurements in lower energies have large errors below the Coulomb barrier. More precise measurements in lower energies for the carbon burning would be useful to improve our study and to understand the evolution of a massive star.
Background: Balance is the foundation of performing daily activities, and has been proven to be improved by various compression materials. As a new and never-before-seen means, the floss band improves joint range of motion, increases muscle flexibility, and affects balance. Several studies using the short-term application of a floss band to the ankle have been conducted. However, long-term effects of the floss band on the knee warrant further research. Objectives: This study aims to examine the long-term benefits of strength exercises with a floss band applied to the knee for static and dynamic balance. Design: Quasi-experimental design. Methods: A total of 28 participants (four men and 24 women, aged 20–60 years) with no orthopedic knee conditions were recruited and randomized into two groups, with 14 in the group using the strength exercises with floss bands applied to the knee (the floss band group), and 14 in the group using internal rotation of the tibia during mobilization with movements (MWM; the MWM group). A physical therapist with 10 years of clinical experience applied the intervention 10 times, measuring static and dynamic balance before and after the intervention using the Balance Trainer 4. Independent t-tests and paired t-tests were used for statistical analysis, with a significance level of ⍺=.05. Results: Statistically significant effects for static balance and dynamic balance were observed in the comparison from pre- to post-intervention between the floss band and MWM groups (P<.05). Additionally, a statistically significant effect for dynamic balance was noted in the pre- to post-intervention comparison in the floss band group (P<.05). Conclusion: The strength exercises with floss bands applied to the knee are expected to have a long-term effect on improving dynamic balance.
The raw material selected for this research was Brazil chestnut shells (BCs), which were utilized to gain porous carbon as a positive electrode for lithium–sulfur batteries (LSBs). The effects of N/S co-doped on the electrochemical properties of porous carbon materials were studied using thiourea as nitrogen and sulfur sources. The experimental results indicate that the N/S co-doped carbon materials have a higher mesopore ratio than the undoped porous carbon materials. The porous carbon material NSPC-2 has a lotus-like structure with uniform pore distribution. The N and S doping contents are 2.5% and 5.4%. The prepared N/S co-doped porous carbon materials were combined with S, respectively, and three kinds of sulfur carbon composites were obtained. Among them, the composite NSPC-2/S can achieve the initial specific discharge capacity of 1018.6 mAh g− 1 at 0.2 C rate. At 1 C rate, the initial discharge capacity of the material is 730.6 mAh g− 1, and the coulomb efficiency is 98.6% and the capacity retention rate is 71.5% after 400 charge–discharge cycles.
In this paper, iron ore tailings (IOT) were separated from the tailings field and used to prepare cement stabilized macadam (CSM) with porous basalt aggregate. First, the basic properties of the raw materials were studied. Porous basalt was replaced by IOT at ratios of 0, 20 %, 40 %, 60 %, 80 %, and 100 % as fine aggregate to prepare CSM, and the effects of different cement dosage (4 %, 5 %, 6 %) on CSM performance were also investigated. CSM’s durability and mechanical performance with ages of 7 d, 28 d, and 90 d were studied with the unconfined compression strength test, splitting tensile strength test, compressive modulus test and freeze-thaw test, respectively. The changes in Ca2+ content in CSM of different ages and different IOT ratios were analyzed by the ethylene diamine tetraacetic acid (EDTA) titration method, and the micro-morphology of CSM with different ages and different IOT replaced ratio were observed by scanning electron microscopy (SEM). It was found that with the same cement dosage, the strengths of the IOT-replaced CSM were weaker than that of the porous basalt aggregate at early stage, and the strength was highest at the replaced ratio of 60 %. With a cement dosage of 4 %, the unconfined compressive strength of CSM without IOT was increased by 6.78 % at ages from 28 d to 90 d, while the splitting tensile strength increased by 7.89 %. However, once the IOT replaced ratio reached 100 %, the values increased by about 76.24 % and 17.78 %, which was better than 0 % IOT. The CSM-IOT performed better than the porous basalt CSM at 90 d age. This means IOT can replace porous basalt fine aggregate as a pavement base.
In this work, we investigated the photo-degradation performance of MnO2-SiC fiber-TiO2 (MnO2-SiC-TiO2) ternary nanocomposite according to visible light excitation utilizing methylene blue (MB) and methyl orange (MO) as standard dyes. The photocatalytic physicochemical characteristics of this ternary nanocomposite were described by X-ray diffraction (XRD), scanning electron microscopy (SEM), tunneling electron microscopy (TEM), ultraviolet-visible (UV-vis), diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS), photocurrent and cyclic voltammogram (CV) test. Photolysis studies of the synthesized MnO2-SiC-TiO2 composite were conducted using standard dyes of MB and MO under UV light irradiation. The experiments revealed that the MnO2-SiC-TiO2 exhibits the greatest photocatalytic dye degradation performance of around 20 % with MB, and of around 10 % with MO, respectively, within 120 min. Furthermore, MnO2-SiC-TiO2 showed good stability against photocatalytic degradation. The photocatalytic efficiency of the nanocomposite was indicated by the adequate photocatalytic reaction process. These research results show the practical application potential of SiC fibers and the performance of a photocatalyst composite that combines these fibers with metal oxides.
Ischemic stroke is a high mortality disease that causes irreversible damage. Chlorogenic acid is a polyphenolic substance with neuroprotective properties. Bcl-2 family proteins perform a critical role in apoptosis process. Bcl-2 and Bcl-xL are anti-apoptotic proteins that prevent cell death, and Bax and Bad are pro-apoptotic proteins that promote apoptosis. We investigated whether chlorogenic acid modulates Bcl-2 family proteins during focal cerebral ischemia. We made a rat model of ischemic stroke by performing middle cerebral artery occlusion (MCAO). Chlorogenic acid (30 mg/kg) or phosphate-buffered saline was treated via intraperitoneal injection 2 hr before MCAO. Neurological behavioral tests were performed 24 hr after MCAO damage and cortical tissues were collected. Reverse transcription-PCR, Western blot, and immunofluorescence staining were performed to observe changes in Bcl-2 family proteins expression. MCAO-damage induced neurobehavioral disorders and chlorogenic acid alleviate these deficits. Bcl-2 and Bcl-xL expressions were decreased and Bax and Bad expressions were increased in MCAO animals. However, chlorogenic acid treatment attenuated the decrease of Bcl-2 and Bcl-xL and the increase of Bad and Bax due to MCAO surgery. Moreover, chlorogenic acid treatment attenuated MCAO-induced upregulation of caspase-3. These findings suggest that chlorogenic acid exerts neuroprotective effects against MCAO damage by regulating Bcl-2 family proteins including Bcl-2, Bcl-xL, Bax, and Bad.
Caprine cryptosporidiosis mainly occurs in young goats, with morbidity rates of 80%–100% and mortality over 50% in goat kids. However, limited research has been conducted on the impact of Cryptosporidium parvum, a diarrhea-causing pathogen, on the intestinal microbiota of goat kids. In this study, 16S rRNA-based metataxonomic analysis was performed to compare the microbial diversity and abundance of the gut microbiota between C. parvum-infected and uninfected goat kids. In total, 12 goat fecal samples were collected, including seven naturally C. parvum-infected and five uninfected goats from Chungcheongbuk-do, Korea. After amplification of the V3–V4 hypervariable region of the bacterial 16S rRNA, high-throughput sequencing was performed. The results showed differences in the microbial composition between C. parvum-infected and uninfected groups based on beta diversity. Firmicutes and Bacteroidetes were the most dominant phyla in both groups. However, no significant difference was observed in the Bacteroidetes/Firmicutes ratio between the two groups. Compared with the uninfected group, the C. parvum-infected group showed significantly higher abundances of Tyzzerella nexillis, Lactobacillus johnsonii, Butyricicoccus pullicaecorum, Enterococcus raffinosus, Enterococcus faecalis, and Negativicoccus massiliensis, and significantly reduced abundances of Aerococcus vaginalis, Faecalicoccus pleomorphus, Oribacterium parvum, and Coprococcus comes. These findings indicate that C. parvum infection, which is associated with diarrhea in neonatal goats, induces alterations in the caprine gut microbiota.
본 연구에서는 Text-to-3D 생성형 AI 기술을 활용하여 메타버스 방 꾸미기 게임의 프로토타 입을 설계하고 구현하고자 하였다. <Roblox>와 <Minecraft>와 같은 가상 현실 기반의 메타버 스 게임은 사용자를 단순한 플레이어에서 창작자인 크리에이터로 발전할 수 있게 하였고 이러 한 재미 요소는 대중적인 인기에 이바지하였다. 생성형 AI는 데이터와 패턴을 기반으로 다양 한 형태의 미디어 콘텐츠를 쉽게 생성할 수 있으며, 게임 개발에도 마찬가지로 유용하다. 이러 한 생성형 AI를 통한 콘텐츠 제작은 시간과 비용을 절약할 뿐만 아니라 결과적으로 콘텐츠의 품질을 높이고 다양성을 확보할 수 있다. 본 연구에서는 언리얼 엔진의 네트워크 프레임워크 를 활용한 리슨 서버(Listen-Server) 방식으로 방 꾸미기 게임을 설계 및 구현하였다. 이 게 임의 핵심 시스템은 메타버스에서 사용자가 쉽게 생성형 AI로 3D 모델을 생성하고, 자신의 방 에 배치할 수 있게 하는 것이다. 본 연구를 통해 코딩 기초 이해는 물론 좀 더 쉬운 방법으로 3D 오브젝트 생성을 통해 사용자가 원하는 메타버스 플랫폼 제작을 가능하게 하며 이러한 과 정은 사용자뿐만 아니라 동시에 창작자의 역할로 이용자의 주체성, 창의성, 의사소통 능력 등 을 향상할 가능성을 찾고자 한다. 그뿐만 아니라 기본적인 코딩 학습을 이해함으로써 사용자 의 창작 활동에 기회를 확장할 뿐만 아니라 메타버스 콘텐츠 개발에 이바지하고자 한다.
Forecasting port container throughput is crucial due to its impact on economic development. Socio-economic factors, which introduce uncertainty, are increasingly integrated into throughput forecasting. The complexity of common multivariate forecasting models significantly affects accuracy, yet few studies compare their performance on the same time series for throughput modeling. This study implements, evaluates, and compares the performance of eight multivariate forecasting models for port throughput within a proposed multiple-input single-output (MISO) system, chosen for their frequent use in container throughput research. It investigates two data preprocessing approaches: Random Forest Variable Importance Method (RF-VIM) and a Multi Lagged Value approach. The comparison uses six error metrics: normalized root mean squared error, mean absolute error, mean absolute percentage error, mean error, and root mean percentage error. Performances are discussed, and recommendations for adopting a suitable model are provided.
Meristem culture (MC) is a technique for producing virus-free garlic plants with high vigor and productivity. We assessed the changes in the agronomic traits of “Namdo” garlic over several generations after the cultivation of MC-induced bulbils. We examined the plant height, leaf sheath length and diameter, leaf number, bulb weight and diameter, clove number, and bulb size distribution. Compared with that of the control, bulb weights of the first-generation bulbils cultivated for three and two years and the second-generation bulbils cultivated for one year increased by 8.7–27.2, 13.9–30.4, and 36.6–46.9%, respectively. In three and two-year cultivation of the firstgeneration bulbils and one-year cultivation of the second-generation bulbils, the proportions of extra-large-sized bulb weight in meristem-cultured plants were 16.2–38.6, 24.0–35.8, and 27.1–51.1%, respectively, whereas that of the control was 7.6%. Thus, the first-generation bulbils can be cultivated for three years to renew the seed bulbs while maintaining productivity.