Restricted and Unrestricted Syntactic Distribution of ar in Bangla

This approach examines the syntactic distribution of ar in Bangla language. Apparently, it seems to occur almost every plausible position across a clause. It may occur clause initially, internally and finally. In some extreme cases, it may occur with each word in a clause. This surface observation does not specify what its exact syntactic distribution is. So, its across clause distributional phenomenon is controversially disputed. In this paper, I shall argue that ar can be restrictedly and unrestrictedly distributed in their respective contexts, thus its apparent multiple syntactic position is a misconception. However, each syntactic distribution either restricted or unrestricted producing a distinct semantic interpretation has specific significance depending on its particular contextual circumstances. This investigation aims at enunciating how every plausible interpretation of ar can be determined based on its restricted and unrestricted syntactic distribution only which in turn reflects its forming of a constituent with the elements following it in a clause. It also shows that the distribution of ar in Bangla is both syntactically and semantically determined.

Corrosion Properties of Biodegradable AZ31 and ZK60 Magnesium Alloys: In Situ Study

Biodegradable magnesium alloys are promising materials for application in medicine. The corrosion rate and type of corrosion are among the most important properties for this kind of materials. The fine-grained biodegradable alloys AZ31 (hot-rolled) and ZK60 (extruded) were studied in the present work with the use of in situ methods including the hydrogen evolution corrosion rate measurement and real-time surface observation as well as ex situ methods such as the weight loss assessment and the post-mortem examination by confocal laser scanning microscopy. The experimental methods included immersion test in SBF (0.9% NaCl aqueous solution) during 120 h with 37 °C with recirculating corrosion media. The hydrogen evolution was measured with a burette with a constant time interval of 1 hour. The real-time surface observation was carried out with a high-resolution camera. The measurement of pH level was done twice a day. Corrosion rate curves, 3D morphology of corroded morphology and video recordings showing evolution of corrosion damage have been obtained. As a result, ZK60 was found to be less corrosion-resistant and addicted to pitting corrosion, whereas AZ31 showed pronounced susceptibility to filiform corrosion.

Analisis Tailwind Penyebab Go-Around pada 38 Bandara di Indonesia dalam Periode Januari-Februari 2020

Studi ini berfokus pada analisis tailwind penyebab go-around pada 38 bandara di Indonesia dalam periode Januari-Februari 2020. Dalam studi ini dilakukan perbandingan tailwind laporan pilot, tailwind observasi permukaan (10 m), dan tailwind pada ketinggian 1000 ft untuk mengetahui akurasi tailwind yang dilaporkan oleh pilot. Literatur menyebutkan bahwa angin kecepatan tinggi di troposfer bawah berkaitan dengan wind gust yang berasal dari awan cumulonimbus (Cb). Dengan dasar tersebut maka dilakukan analisis perbandingan laporan pilot terhadap keberadaan awan Cb sampai sejauh 40 km dari runway in use dengan menggunakan kombinasi kriteria brightness temperature difference (BTD) kanal IR1-IR2 dan brightness temperature (BT) kanal IR1 citra satelit Himawari-8. Hasil penelitian menunjukkan bahwa tailwind laporan pilot lebih besar daripada tailwind angin permukaan dan 1000 ft, serta kebanyakan tailwind laporan pilot tersebut berkaitan dengan potensi wind gust yang muncul dari awan Cb baik di sekitar atau di luar runway.Kata kunci: Cumulonimbus, go-around, tailwind, wind gust. AbstractAn Analysis of Go-Around-Causing Tailwind at 38 Airports in Indonesia in the Period of January-February 2020: This study focused on analyzing the tailwind that causing go-around at 38 airports in Indonesia in the period of January to February 2020. We made a tailwind comparison of the pilot report, surface observation (10 m), and observation of 1000 ft to determine the accuracy of the tailwind reported by the pilot. The literature stated that high-speed winds in the lower troposphere were related to wind gust coming from cumulonimbus (Cb) clouds, so we compared pilot report to the presence of Cb clouds as far as 40 km from the runway in use by using a combination of brightness temperature difference (BTD) IR1-IR2 channels and brightness temperature (BT) IR1 channel of Himawari-8 satellite imagery. The results showed that the tailwind of the pilot report was larger than the tailwind of surface and 1000 ft observations and most of the tailwind was related to the potential wind gust that emerged from the Cb clouds either around or outside the runway.Keywords: Cumulonimbus, go-around, tailwind, wind gust.

Surface Observation of Plasma Electrolytic Oxidation-Treated Ti–6Al–4V Alloy After 2-Step Nano-Mesh Formation

The purpose of this study was to investigate the surface observation of PEO-treated Ti–6Al–4V alloy after 2-step nano-mesh formation was investigated by FE-SEM, EDS, and XRD. Anodic oxidation treatment was performed on the electrolyte containing 0.8 wt.% Na/F and 1M H3PO4 to form a nanotube structure on the Ti–6Al–4V alloy. After removing the nanotube layer, PEO-treatment was performed on the electrolyte containing Mg and Zn ions. After forming the nanotubes, the nanomesh surface was obtained by removing the layer, and the surface roughness increased with cycle number of nanotube formation. Also, as the number of nanotubes increased, the anatase peak increased.

Vertical structure of the transport fluxes of aerosol and its precursors on the southwest transport pathway in the Beijing-Tianjin-Hebei region

<p>Haze pollution caused by atmospheric aerosols has become one of the most severe environmental problems in China, especially in the Beijing-Tianjin-Hebei (BTH) region. Air pollution is not caused by local emission and secondary formation of air pollutants, but also affected by transport from its surrounding areas. A number of studies with respect to the regional transport of air pollutants in the BTH region have been conducted based on surface observation. However, owing to the inhomogeneous vertical distribution of air pollutants and meteorological conditions, the vertical profiles of transport fluxes should be considered for a comprehensive understanding of regional transport. In this study, the vertical profiles of aerosol and its precursor indicators HCHO, NO<sub>2</sub> and SO<sub>2</sub> were observed by ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) at the Nancheng (NC) site in suburban Beijing on the southwest transport pathway. The profiles of the pollutants varied with seasons with more aerosols concentrated at the surface in the winter. Through potential source contribution function (PSCF) analysis, southwest transport pathway was determined as the main transport source region, particularly for air pollutants in the middle and upper boundary layer. The transport fluxes of air pollutants at each vertical layer on the southwest-northeast direction were estimated combining with wind field simulated by WRF-Chem modeling. The average fluxes of the measured pollutants from June 2018 to May 2019 during the southwest transport (from southwest to northeast) were all higher than those during the northeast transport (from northeast to southwest), indicating net input of pollutants to urban Beijing from southwest transport pathway. Except for northwest transport of aerosols, the other maximum transport fluxes occurred at high altitudes instead of at the surface. The proportions of surface flux in the column flux for all the species during southwest transport were higher than those during northeast transport. Surface observation would overestimate the relative contribution from urban Beijing to southwest pathway and underestimate the contribution from southwest pathway to urban Beijing. Southwest transport played an important role on the developing stage of aerosol pollution in urban Beijing in the autumn and winter, and this transport mainly occurred in the middle boundary layer.</p>

Valorisation du stérile d’exploitation des phosphates au Maroc dans la fabrication de carreaux céramiques

L’objectif de ce travail est d’étudier une voie de valorisation du stérile d’exploitation des phosphates comme matière première alternative dans l’industrie céramique. Cinq formulations sont étudiées pour produire par pressage à sec des carreaux céramiques. Ces formulations sont réalisées en mélangeant le stérile avec des argiles locales abondantes selon des pourcentages qui varient de 0 à 100 %. Les carreaux céramiques produits sont caractérisés par leurs propriétés physiques (absorption d’eau, retrait de cuisson), mécaniques (résistance à la flexion) et de surface (observation en microscopie électronique à balayage). Les résultats de cette étude montrent que l’intégration du stérile des mines de phosphates permet d’améliorer les propriétés mécaniques des carreaux céramiques. Une utilisation industrielle de ce déchet minier entre 20 et 50 % dans des formules à base d’argile pourrait donc être envisageable pour concevoir des produits de faïence, conformes aux exigences mécaniques et techniques applicables. Cette voie de valorisation permet de gérer les grandes quantités des rejets miniers et donc leur impact environnemental ainsi que de préserver les ressources naturelles non renouvelables.