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Neutron ◽  
2022 ◽  
Vol 21 (2) ◽  
pp. 97-104
Author(s):  
Maria Siwi Tiarasari ◽  
Irriene Indah Susanti

The development of the construction world in terms of innovation has become one of the methods of supporting success to gain advantages in terms of cost and time, one of which is the outer wall which can generally categorize into cast-in-situ and precast methods. (1) Comparison of the cost of implementing precast kumkang materials, precast concrete facades, and curtain wall facades. The precast kumkang method is 24% cheaper than the precast concrete method, the precast kumkang method is 87% cheaper than the curtain wall method, and the precast concrete method is 52% cheaper than the curtain wall method. Sorted from the cheapest to the most expensive are precast kumkang facades, precast concrete facades, and curtain wall facades. (2) Comparison of the working time of precast kumkang materials, precast concrete facades, and curtain wall facades with the results, namely curtain wall facades for 31 weeks, kumkang material precast facades for 53 weeks, and precast concrete facades for 55 weeks. Sorted from the fastest to longest, namely curtain wall facades, precast kumkang material facades, and then precast concrete facades.  


Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1488
Author(s):  
Emil J. Broemmelsiek ◽  
Joshua L. Rovey ◽  
Steven P. Berg

Hydroxylammonium nitrate (HAN) is an energetic salt used in flight-proven green monopropellants such as ASCENT (formerly AF-M315E), flown in NASA’s 2019 Green Propellant Infusion Mission, and SHP163, flown in JAXA’s Rapid Innovative Satellite Technology Demonstration-1. The decomposition of HAN is catalyzed by metals commonly found in storage tanks, a factor limiting its use. This work investigates the ability of metal-sequestering chelating agents to inhibit the decomposition of HAN. Isothermal and dynamic thermogravimetric analysis (TGA) were used to find isothermal decomposition rates, decomposition onset temperatures, and first-order Arrhenius reaction rate parameters. In the present research, 2,2′-bipyridine (Bipy), triethanolamine (TEA), and ethylenediaminetetraacetic acid (EDTA) were studied as 0.05, 0.1, 0.5, 1, and 5% by weight additives in 90% aqueous HAN. An isothermal decomposition rate of 0.137%/h at 348 K was observed for HAN. The addition of 1% Bipy and 1% TEA reduced the isothermal decomposition rate by 20.4% to 0.109%/h, and by 3.65% to 0.132%/h, respectively, showing that Bipy can inhibit decomposition. The addition of 1% EDTA increased the isothermal decomposition rate by 12.4% to 0.154%/h. Bipy was found to increase the decomposition onset temperature from 454.8 K to 461.8 K, while the results for TEA and EDTA were inconclusive. First order reaction rates calculated by the Ozawa-Flynn-Wall method were found to be insufficient to capture the effects of the tested additives. Bipy was found to inhibit the decomposition of HAN, while TEA and EDTA produced little or negative effect, a result believed to be due to poor metal complex stability at low pH and high acidity, respectively. Spectrophotometry, used for colorimetric analysis of Bipy+iron complexes, showed that Bipy forms chelate complexes with trace iron impurities when added to HAN solutions.


2021 ◽  
Vol 20 (6) ◽  
pp. 482-486
Author(s):  
V. A. Ivanov ◽  
V. V. Krasovskii ◽  
V. F. Gremenok ◽  
L. I. Postnova

Alloys of lead and tin telluride (PbxSn1–xTe) are materials with good thermoelectric properties, as well as semiconductors that can be used as long-wave infrared detectors. Polycrystalline telluride of PbxSn1–xTe (0.05 £ x £ 0.80) alloys has been synthesized by direct fusion technique. Thin films of these materials have been obtained by the hot wall method depositing Сorning 7059 on glass substrates at Tsub = (200–350) oC and vacuum of about 10–5 Torr. The microstructure of the films has been investigated by XRD, SEM and EDX methods. The X-ray spectra of thin films have been in satisfactorily agreement with the spectra of the powder target and indicated the absence of binary phases. The films have shown a natural cubic crystalline structure. While increasing the lead content, the unit cell parameter of the crystal also increases. The established linear relationship between the unit cell parameter and the elemental composition corresponds to Vegard's law. The SEM analysis has shown that the films are polycrystalline, have a columnar structure, are tightly packed and have good mechanical adhesion. The grain size depends on the chemical composition and temperature of the substrate. The electrical measurements have shown that the grown films are non-degenerate semiconductors of p-type conductivity. The conductivity of the films was in the range of σ = (3 × 101)–(1 × 104) Ω–1×cm–1. An increase of lead concentration leads to a decrease in electrical conductivity. Hall mobility in the grown thin films increases in the range of changes in the lead content from ~10 to ~23 at. %, and decreases with a further increase to ~33 at. %. At the same time, the strongest dependence of the decrease in mobility on an increase in temperature increase is observed for films with a high lead content and is explained by the predominant scattering of charge carriers by vibrations of the crystal lattice. For a sample with an average lead concentration, an alternative effect of two scattering mechanisms is observed in the temperature dependence of the mobility: by impurity ions and by phonons.


2021 ◽  
Vol 11 (12) ◽  
pp. 2435-2440
Author(s):  
Hui Xie ◽  
Zhe Xu ◽  
Binbin Cai ◽  
Jie Weng ◽  
Yanhong Qi

Our study aims to assess the role of BMSCs (MSCs) transplantation in combination with miR-36b in the repair of septic lung injury. MSCs were cultured by the paste-wall method and characterized. MSCs combined with miR-36b medium were added to lung-injured cells for 14 days followed by analysis of cell viability by CCK-8 assay, GLUT3 expression and apoptosis by western blot. After 1 and 3 days of growth of MSCs progeny under electron microscopy, the MSCs showed long shuttle-shaped morphology. MSCs in combination with miR-36b resulted in enhanced proliferative capacity of lung-injured cells and enhanced protein expression of GLUT3. CCK-8 assay showed increased viability of lung-injured cells and elevated protein and mRNA expression of GLUT3. Meanwhile, the expression of apoptosis-related proteins was significantly down-regulated. In conclusion, MSCs in combination with miR-36b therapy may ameliorate lung injury by promoting lung cell proliferation through inhibition of apoptotic pathway.


Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1143
Author(s):  
Yuliya Mikhailovna Spivak ◽  
Irina Evgen’evna Kononova ◽  
Pavel Vasil’evich Kononov ◽  
Vyacheslav Alexeyevich Moshnikov ◽  
Sergey Anatol’evich Ignat’ev

A model is developed for the formation of porous intragranular architectonics of nanostructured polycrystalline layers of lead chalcogenides for photodetectors and IR emitters. The layers are obtained under the conditions of thermal evaporation in a quasi-closed volume by the “hot wall” method followed by sensitizing heat treatment in an iodine-containing atmosphere. Model concepts are developed considering the experimental results of studying the intragranular structure of lead chalcogenides through original combined AFM methods over the cross-section of porous grains (cores) encapsulated by an oxide shell (lateral force microscopy and local tunneling I–V spectroscopy).


2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.


Agriculture ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 503
Author(s):  
Roman Kemper ◽  
Tábata A. Bublitz ◽  
Phillip Müller ◽  
Timo Kautz ◽  
Thomas F. Döring ◽  
...  

Many benefits of cover crops such as prevention of nitrate leaching, erosion reduction, soil organic carbon enhancement and improvement of soil structure are associated with roots. However, including root characteristics as a criterion for cover crop selection requires more knowledge on their root growth dynamics. Seven cover crop species (crimson clover, winter rye, bristle oats, blue lupin, oil radish, winter turnip rape and phacelia) were grown in a two-year organically managed field experiment in Germany to screen them for root intensity and vertical root distribution. Root length density (RLD) and proportion of root length in large-sized biopores were determined before and after winter with the profile wall method. RLD and cumulative root length were analysed using a three-parameter logistic function, and a logistic dose-response function, respectively. Fibrous rooted winter rye and crimson clover showed high RLD in topsoil and had a shallow cumulative root distribution. Their RLD increased further during winter in topsoil and subsoil. The crops with the highest RLD in the subsoil were taprooted oil radish, winter turnip rape and phacelia. Bristle oat had intermediate features. Blue lupin had low RLD in topsoil and subsoil. Phacelia, oil radish, winter turnip rape and bristle oat showed the highest share of root length in biopores. These complementary root characteristics suggest that combining cover crops of different root types in intercropping may be used to enhance overall RLD for maximizing cover crop benefits.


2020 ◽  
Vol 99 ◽  
pp. 103382 ◽  
Author(s):  
Hui Wang ◽  
Cheng Jiang ◽  
Pengqiang Zheng ◽  
Wenjuan Zhao ◽  
Nan Li

2020 ◽  
Vol 99 ◽  
pp. 103385
Author(s):  
Peng Jiang ◽  
Qing-song Zhang ◽  
Ren-tai Liu ◽  
Adam Bezuijen ◽  
Yan-kai Liu ◽  
...  

Author(s):  
Hanifah Nur Azizah

Application of the word wall  method is one of alternative to improve students Arabic vocabulary. A problem for student of class III A in MI Al-Ba’ats is the low of Arabic vocabulary which has an impact on the students learning outcomes. The aim of this skills research are to improve of students Arabic vocabulary skills by using  word wall media. This research used the Classroom Action Research (CAR) with fourth cycles. Each cycles concisted of six phases, which: identification of problems, need assessment, idea, implication, and decision making. The subject of the research are 21 students of the class III A MI Al-Ba’ats. The data sources of the research are the research and students. Data collection techniques are used an observation, an interview, tests and documentation. If the individual completeness reaches ≥ 65 and if value of the whole completeness reaches 75% of the students more than ≥ 65, then it could he said as a complete learning outcomes. The average value of learning outcomes in the pre-action is 62 and the value of the whole completeness is 33.3%. The average value of learning outcomes in the first cycle 69 and the value of the whole completeness is 66.7%. The average value of learning outcomes in the second cycle is 73 and the value of the whole completeness is 85.7%. The average value of learning outcomes in the third cycle is 80 and the value of the whole completeness is 95.2%. The average value of learning outcomes in the fourth cycle is 80.1 and the value of the whole completeness is 95.2%. The conclution of this research is by using word wall media, it can improve students Arabic vocabulary skills at class III A of MI Al-Ba’ats.


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