エピタキシャルPZT薄膜を用いた高性能圧電マイクロマシンド超音波トランスデューサのプロセス統合

要約のみTohoku University田中秀治課

Silvicultural Characteristics Of Dipterocarpus Rensus In Thai Nguyen Province, Vietnam

Dipterocarpus rensus, a long-exploited species in Thai Nguyen Province, Vietnam, is currently documented with only 244 individuals observed across scattered locations within strictly protected natural forests. This study aimed to elucidate the distribution and silvicultural characteristics of D. rensus in Thai Nguyen, providing essential insights for the conservation and sustainable development of its genetic resources. Our findings underscore a sparse population of D. rensus in Thai Nguyen, primarily concentrated within National Parks and Conservation Areas. The species composition formula for the natural distribution of D. rensus encompasses diverse tree species, including Broussonetia papyrifera, Allospondias lakonensis Pierre, Choerospondias axillaris, Fagus sylvatica, Machilus velutina Champ, Canarium album, Engelhardtia chrysolepis, Peltophorum dasyrhachis, Alangium chinense, Vatica odorata, Duabanga grandiflora, Sargentodoxa cuneata, Amesiodendron chinense, and Nephelium chryseum. The regenerative seedling composition is dominated by pioneer, fast-growing species such as Broussonetia papyrifera, Allospondias lakonensis Pierre, Fagus sylvatica, Machilus velutina Champ, Zenia insignis, Engelhardtia chrysolepis, Archidendron clypearia, Pterospermum acerifolium Willd, Bischofia javanica, Vatica odorata, Duabanga grandiflora, Sargentodoxa cuneata, Broussonetia papyrifera, Aesculus assamica, and Amesiodendron chinense. The study highlights the poor regeneration ability of D. rensus, emphasizing the necessity for research on cultivation techniques to effectively conserve and harness the genetic resources of this valuable species

The VATLY Radio Telescope

A small radio telescope (SRT) has been installed on the roof of the Hanoi astrophysics laboratory VATLY. It is equipped with a 2.6 m diameter mobile parabolic dish remotely controlled in elevation and azimuth and with super-heterodyne detection around the 21 cm hydrogen line. First results of observations of the Sun and of the centre of the Milky Way are presented. They demonstrate the high quality of the telescope performance and are used to evaluate lobe size, signal to noise ratios, anthropogenic interferences and measurement accuracies. Particular attention is given to the measurement of the pointing accuracy. The rich measurement programme that is now at hand is briefly sketched

Simulation of proton-induced and iron-induced extensive air showers at extreme energies

The development of extensive air showers at extreme energies is studied using a simulation model much simpler and cruder, but also more transparent and flexible, than existing sophisticated codes. Evidence for its satisfactory performance is presented. As an illustration, shower elongation rates are evaluated in the $10^{18}$ to $10^{20}$ eV region and compared with recently published data. Lateral distribution functions of both muons and electrons/photons are also briefly discussed. Reliable results are obtained in the comparison between proton-induced and iron-induced showers.Comment: 22 pages, Preprint submitted to Astroparticle Physic

ANALYSIS OF THE POPULARITY OF VOCABULARY USED WHEN PERFORMING SPEAKING ACTIVITIES IN THE CLASS OF FIRST-YEAR ENGLISH LANGUAGE STUDENTS IN THE DIRECTION OF DISCOURSE ANALYSIS

Vocabulary learning is extremely important when learning a foreign language. Fluency in a language depends on vocabulary and its use in specific situations. Speaking well is using vocabulary flexibly and speaking fluently. Researching the popularity of vocabulary is analyzing the prevalence of vocabulary used by linguistics students in communication from discourse analysis. This is a topic the research team is working on. This project will help the researchers learn about common vocabulary that students often use to communicate outside or in the classroom. Thereby understanding whether the vocabulary that students use is diverse, rich, and for the right purpose or not. This study will help students have a more comprehensive view of the ways to use words in communication. In addition, it also helps students improve their communication vocabulary, helps in exams and can be useful for later work. In this study, the research team will investigate the students' ability to use spoken vocabulary, i.e., frequency and extent of vocabulary usage.  Article visualizations

Response of Water Cherenkov Detectors to Small Signals: a Case Study

Detailed studies of the response of the VATLY water Cherenkovdetector, a replica of those used in the ground array of the PierreAuger Observatory, are presented with emphasis on the response to lowamplitude signals. The method used is to detect decay electrons frommuons stopping in the water volume. Results include properties of the detection process as well as of the atmospheric cosmic ray flux

Investigation on Air Pollution in Vietnam : Concentration of Water-soluble Ions in Suspended Particulate Matters

Joint Research on Environmental Science and Technology for the Eart

Extensive Air Showers and the LPM Effect

A very simple model of thelongitudinal development of electromagnetic showers is presented,allowing for easy calculations at the highest energies where usualsimulation codes become impracticable because of the enormousmultiplicity of secondary shower particles. Shower profiles aredescribed in terms of a few parameters having Gaussianfluctuations. The model is applied to the impact of theLandau-Pomeranchuk-Migdal effect on the shower development, whichis found negligible in practical cases