Статті в журналах: "VHS steel"

1

Nabi, Junaid, and S. Elavenil. "Analytical study on innovative VHS-steel section stub CFT columns." Asian Journal of Civil Engineering 19, no. 5 (April 3, 2018): 527–34. http://dx.doi.org/10.1007/s42107-018-0039-y.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Jiao, H., and X. L. Zhao. "CFRP strengthened butt-welded very high strength (VHS) circular steel tubes." Thin-Walled Structures 42, no. 7 (July 2004): 963–78. http://dx.doi.org/10.1016/j.tws.2004.03.003.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Jiao, Hui, and Xiao-Ling Zhao. "Material ductility of very high strength (VHS) circular steel tubes in tension." Thin-Walled Structures 39, no. 11 (November 2001): 887–906. http://dx.doi.org/10.1016/s0263-8231(01)00039-8.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Jiao, Hui, and Xiao-Ling Zhao. "Tension Capacity of Very High Strength (VHS) Circular Steel Tubes after Welding." Advances in Structural Engineering 7, no. 4 (August 2004): 285–96. http://dx.doi.org/10.1260/1369433041653534.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Jiao, Hui, and Xiao-Ling Zhao. "Strengthening Tests of Butt-Welded Very High Strength (VHS) Circular Steel Tubes." IABSE Symposium Report 86, no. 4 (January 1, 2002): 49–56. http://dx.doi.org/10.2749/222137802796337323.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Mashiri, Fidelis R., Brian Uy, Zhong Tao, and Zhi-Bin Wang. "Concrete-filled VHS-to-steel fabricated section stub columns subjected to axial compression." Journal of Constructional Steel Research 95 (April 2014): 141–61. http://dx.doi.org/10.1016/j.jcsr.2013.11.022.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Heidarpour, Amin, Sanel Cevro, Qian-Yi Song, and Xiao-Ling Zhao. "Behaviour of stub columns utilising mild-steel plates and VHS tubes under fire." Journal of Constructional Steel Research 95 (April 2014): 220–29. http://dx.doi.org/10.1016/j.jcsr.2013.12.007.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Alatshan, F., and Fidelis R. Mashiri. "Finite Element Modeling of Concrete-Filled Steel Tubes: Review and Recent Developments." Applied Mechanics and Materials 330 (June 2013): 894–99. http://dx.doi.org/10.4028/www.scientific.net/amm.330.894.

Повний текст джерела

Анотація:

The paper reviews previous investigations in the area of finite-element modeling of concrete-filled steel tubes. The literature provides a summary of the main type of the elements that are most frequently used to simulate concrete, steel and the interaction between the steel and the concrete in the composite beam and column members. A summary of confined concrete models is presented. Finally, finite-element were developed for 12 triangular concrete filled fabricated VHS-plate stub column specimens tested and reported in previous research [1, 2]. The confined concrete models, reviewed in the literature, were employed in the simulation and comparison was made to find the most suitable model for this type of column.

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Kouichirou, Anno, and Takeshi Nishihata. "DEVELOPMENT ON OFFSHORE STRUCTURE." Coastal Engineering Proceedings 1, no. 32 (January 31, 2011): 50. http://dx.doi.org/10.9753/icce.v32.structures.50.

Повний текст джерела

Анотація:

Authors have developed the offshore structure for control of sea environment named S-VHS construction method, which is composed of the sloping top slit-type caisson and steel pipe piles. The sloping top form enables to realize the remarkable reduction of wave force exerted on the dike body compared with the conventional one. In this paper, hydraulic feature with wave dissipation ability and wave force reduction effect are verified through some hydraulic experiments. After the preliminary study for the valid structure form, reflection and transmission ability for the selected structure models were tested with the hydraulic experiment relevant to the ratio of caisson width and wave length. Finally, wave force experiment was executed and it revealed the performance of wave force reduction. Based on the results, we proposed specific design wave force formula for S-VHS construction method.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Jiao, H., and X. L. Zhao. "Imperfection, residual stress and yield slenderness limit of very high strength (VHS) circular steel tubes." Journal of Constructional Steel Research 59, no. 2 (February 2003): 233–49. http://dx.doi.org/10.1016/s0143-974x(02)00025-1.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Jiao, Hui, Fidelis Mashiri, and Xiao-Ling Zhao. "Fatigue behavior of very high strength (VHS) circular steel tube to plate T-joints under in-plane bending." Thin-Walled Structures 68 (July 2013): 106–12. http://dx.doi.org/10.1016/j.tws.2013.03.006.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Editor, IJoST. "PREFACE." Indonesian Journal of Science and Technology 1, no. 2 (September 9, 2016): 00. http://dx.doi.org/10.17509/ijost.v1i2.3828.

Повний текст джерела

Анотація:

PREFACEIndonesian Journal of Science and Technology (IJoST) is a peer-reviewed journal that aims to publish and disseminate innovative research articles on the latest developments in all fields of science and technology. The journal publishes original papers in English, which contribute to the understanding of science and improvement of the science and technology. Papers may be theoretical explanation (including computational), experimental observation and analysis, or combination from both theoretical and experimental analysis. The contribution should be unpublished before and not under consideration for publication in elsewhere. IJoST maintains a standard double-blind peer review process. The review process means that the identity with the author, and the reviewer are not known to each other. IJoST is an open-access journal, and in this issue IJoST does not charge for readers, authors, or their institutions for access to the journal articles. This journal was firstly published on April 30, 2016, and issued every April and September in each year, published by Tim Pengembang Jurnal at Universitas Pendidikan Indonesia.In this issue, we published nine papers, including seven original research articles and two review papers. In this issue, we received papers from remarkable researchers in several countries in the world, including Iran, Italy, Malaysia, South Korea, The Netherlands, and Indonesia. The first paper discussed about photodecomposition profile of organic material during the partial solar eclipse of 9 March 2016. The next paper presented about techno-economic assessment of coal to SNG power plant in Kalimantan. In the third paper, authors discussed about how to optimize and plan for Designing VHS Building Using Chronolux, in which this can be used for school building. In the fourth paper, authors discussed about project for offshore horizontal directional drilling (HDD) for pipeline crossing in Bukit Tua, Indonesia. The fifth article presented method for detecting mango tree varieties based on image processing. The next paper discussed on the relationship between social performance and corporate financial performance. The sixth paper described high temperature oxidation behavior of T91 steel in dry and humid condition. The seventh is a review article regarding early phase process evaluation, in which this evaluation based on industrial practices. The last paper is a review on module-scale simulation of forward osmosis module in the focus of Plate-and-Frame.We believe that this issue will give benefits for the improvement and the development of science and technology.Bandung, September 2016 Editor

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Henkes, H., P. Drepper, J. Speder, S. Felber, H. Monstadt, and D. Kühne. "Technical Note on VDS." Interventional Neuroradiology 8, no. 2 (June 2002): 197–200. http://dx.doi.org/10.1177/159101990200800212.

Повний текст джерела

Анотація:

A new system was deviced that allows the electrolytical detachment of platinum microcoils at variable lengths for the endovascular treatment of intracranial aneurysms. The detachment element consists of two short platinum coil segments, which are connected by a threat of stainless steel. The steel threat is interrupted by electrolysis, using a continuous current with 1–2 mA at a voltage of 4–8 Volt. The average detachment time in heparinized blood is about 30–40 sec. The detachment elements can be used to connect either an insertion wire with a platinum coil or to connect several segments of platinum coils with variable helices and lengths. If several detachment elements are integrated in a coil, electrolysis interrupts only the element, which is next beyond the distal tip of the catheter. The electrolytical process does not affect the detachment elements proximal and distal to the element adjacent to the tip of the catheter. Single or several coil segments can be pulled back into the microcatheter if necessary. The system is expected to allow a faster and more complete endovascular coil occlusion of intracranial aneurysms. The principles described in this paper are claimed by the German pending patent DE 100 10840 A1.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Da, Bo, Hongfa Yu, Haiyan Ma, Bo Yu, Zhangyu Wu, and Jianbo Guo. "Study on shear behavior of reinforced coral aggregate concrete beam." Advances in Structural Engineering 23, no. 11 (April 13, 2020): 2388–98. http://dx.doi.org/10.1177/1369433220915610.

Повний текст джерела

Анотація:

Reinforced coral aggregate concrete beam and reinforced ordinary aggregate concrete beam with different concrete type, concrete strength, and steel type were designed in this study to investigate their shear behavior. The shear behavior of reinforced coral aggregate concrete beam was tested, the failure mode and deflection behavior were studied, and the calculating model for the ultimate shear capacity ( Vcs) of reinforced coral aggregate concrete beam was proposed. Results showed that the failure mode of reinforced ordinary aggregate concrete beam and reinforced coral aggregate concrete beam were basically the same. As the concrete strength increases, the normal section cracking load ( Vcr), inclined section Vcr, and Vcs of reinforced coral aggregate concrete beam increased gradually. Furthermore, Vcr and Vcs of reinforced coral aggregate concrete beam were as follows: 316 stainless steel > common steel > zinc-chromium coated steel > new organic coated steel. For the coral aggregate concrete structure in ocean engineering, in order to prolong its service life, the use of new organic coated steel was suggested. At the same time, the influence of high-strength coral aggregate concrete and stirrup corrosion was comprehensively considered and the calculation model for the Vcs of reinforced coral aggregate concrete beam was presented and was then verified.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

IWASAWA, Tomoya, Naoya MIYAUCHI, Shoji TAKAGI, Yoshiharu MURASE, Yoichi YAMADA, Akiko ITAKURA, and Masahiro SASAKI. "Observation of Behavior of Deuterium Permeated Through Stainless Steel." Vacuum and Surface Science 62, no. 10 (October 10, 2019): 635–40. http://dx.doi.org/10.1380/vss.62.635.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

16

AOYAGI, Satoka, Tomomi AKIYAMA, Natsumi SUZUKI, Naoya MIYAUCHI, and Akiko N. ITAKURA. "Multimodal Data Analysis for Evaluating Hydrogen Diffusion in Steel." Vacuum and Surface Science 64, no. 10 (October 10, 2021): 472–75. http://dx.doi.org/10.1380/vss.64.472.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

17

ITAKURA, A. N., M. TOSA, T. YAKABE, N. MIYAUCHI, A. KASAHARA, T. MIYATA, and T. SHINDO. "Low Outgas Surface Treatment of Stainless Steel 316L Using Segregated Chromium Oxide Layer." Vacuum and Surface Science 61, no. 10 (October 10, 2018): 675–80. http://dx.doi.org/10.1380/vss.61.675.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

18

IRIE, Norihiro. "The Factory Tour of Cooperation Committee. JFE Steel Corporation East Japan Works Chiba." Vacuum and Surface Science 61, no. 11 (November 10, 2018): 741–42. http://dx.doi.org/10.1380/vss.61.741.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Lu, Hao, Ling Yang, Bin Hou, Meng Zhang, Mei Wu, Xiao-Hua Ma, and Yue Hao. "AlN/GaN/InGaN coupling-channel HEMTs with steep subthreshold swing of sub-60 mV/decade." Applied Physics Letters 120, no. 17 (April 25, 2022): 173502. http://dx.doi.org/10.1063/5.0088585.

Повний текст джерела

Анотація:

This work reports an AlN/GaN/InGaN high electron mobility transistor (HEMT) with a steep subthreshold swing (SS) of sub-60 mV/dec utilizing a coupling-channel architecture. The fabricated transistors show a negligible hysteresis, a SS of 39 mV/dec, a large gate voltage swing of >4.2 V, and achieving an excellent quality factor Q = gm/SS of 6.3 μS-dec/ μm-mV. The negative differential resistance effect was found in the subthreshold region in the gate current–voltage ( Ig– VGS) curve. The hot carrier transfer mechanism that occurred in the turn-on/pinch-off progress of the CC-HEMT under the dual-directional sweep, proved by the VDS- and Lg-dependent bi-directional transfer I–V characteristics, can be responsible for these excellent device performances. This work is believed to encourage further study of the AlN/GaN platform to power the future group III-nitrides CMOS technology.

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Lu, Hao, Ling Yang, Bin Hou, Meng Zhang, Mei Wu, Xiao-Hua Ma, and Yue Hao. "AlN/GaN/InGaN coupling-channel HEMTs with steep subthreshold swing of sub-60 mV/decade." Applied Physics Letters 120, no. 17 (April 25, 2022): 173502. http://dx.doi.org/10.1063/5.0088585.

Повний текст джерела

Анотація:

This work reports an AlN/GaN/InGaN high electron mobility transistor (HEMT) with a steep subthreshold swing (SS) of sub-60 mV/dec utilizing a coupling-channel architecture. The fabricated transistors show a negligible hysteresis, a SS of 39 mV/dec, a large gate voltage swing of >4.2 V, and achieving an excellent quality factor Q = gm/SS of 6.3 μS-dec/ μm-mV. The negative differential resistance effect was found in the subthreshold region in the gate current–voltage ( Ig– VGS) curve. The hot carrier transfer mechanism that occurred in the turn-on/pinch-off progress of the CC-HEMT under the dual-directional sweep, proved by the VDS- and Lg-dependent bi-directional transfer I–V characteristics, can be responsible for these excellent device performances. This work is believed to encourage further study of the AlN/GaN platform to power the future group III-nitrides CMOS technology.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Scribante, Andrea, Maria Francesca Sfondrini, Simona Broggini, Marina D'Allocco, and Paola Gandini. "Efficacy of Esthetic Retainers: Clinical Comparison between Multistranded Wires and Direct-Bond Glass Fiber-Reinforced Composite Splints." International Journal of Dentistry 2011 (2011): 1–5. http://dx.doi.org/10.1155/2011/548356.

Повний текст джерела

Анотація:

The purpose of this longitudinal prospective randomized study was to evaluate the reliability of two different types of orthodontic retainers in clinical use: a multistrand stainless steel wire and a polyethylene ribbon-reinforced resin composite. Moreover the level of satisfaction of the patient about the esthetic result was also analyzed by means of a Visual Analogue Scale (VAS). 34 patients (9 boys and 25 girls, mean age 14.3), in the finishing phase of orthodontic treatment, were selected for the study. Since splints were applied the number, cause, and date of splint failures were recorded for each single tooth over 12 months. Statistical analysis was performed using a paired -test, Kaplan Meier survival estimates, and the log-rank test. Kruskal Wallis test was performed to analyze VAS recordings. Differences between the bond failure rates were not statistically significant. Esthetic result of VAS was significantly higher for polyethylene ribbon-reinforced resin retainers than for stainless steel wires.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

KUBO, Takashi, and Keijiro NAKASA. "Field Emission Properties of Protrusions Fabricated by Sputter Etching of SUS420J2 Steel, Oxygen Free Copper and Ni Plates." Vacuum and Surface Science 63, no. 10 (October 10, 2020): 542–47. http://dx.doi.org/10.1380/vss.63.542.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Lindfors, Elina. "Very high energy gamma-rays from flat spectrum radio quasars." Proceedings of the International Astronomical Union 10, S313 (September 2014): 27–32. http://dx.doi.org/10.1017/s1743921315001817.

Повний текст джерела

Анотація:

AbstractThe detection of Flat Spectrum Radio Quasars (FSRQs) in the Very High Energy (VHE, E>100 GeV) range is challenging, mainly because of their steep soft spectra and distance. Nevertheless four FSRQs are now known to be VHE emitters. The detection of the VHE γ-rays has challenged the emission models of these sources. The sources are also found to exhibit very different behavior. I will give an overview of what is known about the VHE emission of these sources and about the multiwavelength signatures that are connected to the VHE gamma-ray emission.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Jamil, Sara, Rizwan Jouhar, Dinaz Gandhi, Tayyaba Tahira, and Jamshed Shaikh. "Comparison between the mean postoperative pain score with two different file systems in patients with irreversible pulpitis-a clinical study in Altamash Institute of Dental Medicine." Professional Medical Journal 26, no. 08 (August 10, 2019): 1359–64. http://dx.doi.org/10.29309/tpmj/2019.26.08.89.

Повний текст джерела

Анотація:

Endodontic Pain if occurs after few hours or days after the treatment indicates a poor pathosis and a bad prognosis in long term, due to this a newer generation of instruments for canal treatment has been introduced from Ni-Ti alloy which has even better ability to shape narrow and curved root canals, without causing aberration. To compare the mean postoperative pain score after manual SS (stainless steel) K-files and mechanical Ni-Ti rotary path files in patients with irreversible pulpitis. Study Design: Randomized controlled trial. Setting: Department of Operative Dentistry, Altamash Institute of Dental Medicine, Karachi. Period: 6 months from 01-10-2017 to 30-03-2018. Materials and Methods: Total 60 patients of irreversible pulpitis with moderate pain score ≥5 were included and divided equally in manual stainless-steel k-files and mechanical Ni-Ti rotary path files groups. Treatment was started with local anesthesia. Patients were recalled after 24 hours and the level of postoperative pain was examined. T-test was applied to compare the outcome in both groups. Stratification was done using t-test and P value ≤0.05 was significantly considered. Results: The mean pre-treatment VAS in group-A and group-B was 7.16±1.44 and 7.86±1.38 respectively. Mean post-treatment VAS in group-A and group-B was 2.33±1.02 and 1.10±0.66 respectively. A significant difference between the pre and post op pain was noted between the two groups, when compared after 24hours by using VAS. Conclusion: Mean post-operative pain score was significantly less with NiTi rotary path files as compare to manual stainless steel K-files.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Nanda, P. K., B. Ghose, and T. N. Swain. "Parallel genetic algorithm based unsupervised scheme for extraction of power frequency signals in the steel industry." IEE Proceedings - Vision, Image, and Signal Processing 149, no. 4 (2002): 204. http://dx.doi.org/10.1049/ip-vis:20020501.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Filippatos, Angelos, Tino Wollmann, Minh Nguyen, Pawel Kostka, Martin Dannemann, Albert Langkamp, Loic Salles, and Maik Gude. "Design and Testing of a Co-Rotating Vibration Excitation System." Sensors 19, no. 1 (December 28, 2018): 92. http://dx.doi.org/10.3390/s19010092.

Повний текст джерела

Анотація:

A vibration excitation system (VES) in a form of an active coupling is proposed, designed and manufactured. The system is equipped with a set of piezoelectric stack actuators uniformly distributed around the rotor axis and positioned parallel to each other. The actuator arrangement allows an axial displacement of the coupling halves as well as their rotation about any transverse axis. Through the application of the VES an aimed vibration excitation is realised in a co-rotating coordinate system, which enables a non-invasive and precise modal analysis of rotating components. As an example, the VES is applied for the characterisation of the structural dynamic behaviour of a generic steel rotor at different rotational speeds. The first results are promising for both stationary and rotating conditions.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Winsley, R. J., N. R. Smart, and C. Padovani. "Experimental study to evaluate the effect of polymeric encapsulants on the corrosion resistance of intermediate-level radioactive waste packages." Mineralogical Magazine 76, no. 8 (December 2012): 2957–67. http://dx.doi.org/10.1180/minmag.2012.076.8.11.

Повний текст джерела

Анотація:

AbstractIntermediate-level radioactive waste is normally encapsulated in cementitious grout. However, for some wastes, grout may not be suitable and polymeric encapsulants are being considered as an alternative. One concern with such encapsulants is their long-term chemical stability and the possibility that release of aggressive degradation products could cause corrosion.This paper evaluates the potential for three polymeric encapsulants: two epoxy resins (the APS polymer system, (APS) and Alchemix 4760 (ALC)) and a vinyl-ester styrene (VES); to cause internal corrosion of stainless steel waste containers. The corrosion behaviour of stainless steel 316L in contact with each encapsulant was studied in saturated Ca(OH)2 solutions and deionized (DI) water, at 80°C, under non-irradiated and γ-irradiated conditions.In aerated, alkaline conditions, 316L was resistant to corrosion in all the conditions tested. However, in DI water, the pH fell to values as low as three due to release of acidic species from the polymers. The two epoxy materials (particularly APS) also released significant levels of chloride; VES did not. Chloride release appeared to be increased by γ-irradiation. As a result of the low pH chloride-containing environment created by the APS encapsulant, 316L experienced localized corrosion, whereas coupons in Alchemix 4760 and VES did not. Weight loss measurements correlated with visual observations. γ-irradiation appeared to increase the degree of corrosion.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Liu, Yongwei, Hongxu Jiang, Yalin Li, and Dejiang Shang. "Suppression of the Hydrodynamic Noise Induced by the Horseshoe Vortex through Mechanical Vortex Generators." Applied Sciences 9, no. 4 (February 20, 2019): 737. http://dx.doi.org/10.3390/app9040737.

Повний текст джерела

Анотація:

The hydrodynamic noise from the horseshoe vortex can greatly destroy the acoustic stealth of underwater vehicles at low frequency. We investigated the flow-induced noise suppression mechanism by mechanical vortex generators (VGs) on a SUBOFF model. Based on the numerical simulation, we calculated the flow field and the sound field of the three shapes of mechanical VGs: triangular, semi-circular, and trapezoidal. The triangular VGs with an angle of 30° to the flow direction achieved a better noise reduction. The optimum noise suppression is 8.93 dB, when the distance from the triangular VGs to the sail hull’s leading edge is 0.1c, where c is the chord length. The noise reduction mechanism is such that the mechanical VGs can destroy the formation of the horseshoe vortex at the origin and produce counter-rotation vortices to weaken its intensity. We created two steel models according to the simulation, and the experimental measurement was carried out in a gravity water tunnel. The measured results showed that the formation of the horseshoe vortex could be effectively inhibited by the triangular VGs. The results in our study can provide a new method for hydrodynamic noise suppression by flow control.

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Mrdak, Mihailo, Časlav Lačnjevac, Marko Rakin, Đorđe Janaćković, and Darko Veljić. "Characterization of vacuum plasma spray VPS - W coating deposited on stainless steel substrates." Zastita materijala 62, no. 2 (2021): 106–12. http://dx.doi.org/10.5937/zasmat2102106m.

Повний текст джерела

Анотація:

In this paper, studied was the melting of W powder particles in plasma, their behavior at oxidation as well as the mechanism of hardening on the surface of the substrate. Tungsten coating layers were deposited with vacuum plasma spray technology (VPS) on the test specimens of steel Č.4171 (X15Cr13 EN10027). VPS technology has advantages over the APS technology due to decreased oxidation of melted powder particles, by producing a coating with a controlled proportion of micro pores and greater uniformity of the deposited layers. Evaluation of mechanical characteristics of the layers was done by examining the microhardness using the HV0.3 method and tensile bond strength by tensile testing. The microstructures of the deposited layers were analyzed by means of optical microscopy (OM) and scanning electron microscopy (SEM). The results obtained showed that the tungsten coating consisted of well melted particles that interconnected and were overlapping, which shows a typical lamellar microstructure. Present in the microstructure are micro pores in very small proportion at the inter-lamellar boundaries. Tests have shown that layers of W coating deposited by plasma spray in inert gas shielding at low pressure have good mechanical properties and microstructure, which in the fully enables its use in exploitation.

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Ricci, Anthony J., Stephen L. Cochran, Katherine J. Rennie, and Manning J. Correia. "Vestibular Type I and Type II Hair Cells. 2: Morphometric Comparisons of Dissociated Pigeon Hair Cells." Journal of Vestibular Research 7, no. 5 (October 1, 1997): 407–20. http://dx.doi.org/10.3233/ves-1997-7504.

Повний текст джерела

Анотація:

Morphometric properties of solitary hair cells dissociated from the semicircular canals (SCC), utricles (UTR), and lagenas (LAG) of adult white king pigeons, Columba livia, were compared. Measurements were made of the cell body, cuticular plate and hair bundle. Cells were divided into two groups: type 1 (group 1) was predominantly type I hair cells, and type 2 (group 3) was primarily type II hair cells. Comparisons are made initially between end organs for each group. A subpopulation of short otolith hair cells was identified. Quantitative comparisons between isolated type 1 and type 2 hair cells demonstrated that type 1 hair cells were more homogeneous both within and between vestibular end organs; while they had shorter, thinner neck regions, narrower apical surfaces, with longer and thinner bodies than did type 2 hair cells. Generally, for both type 1 and type 2 hair cells, two different hair bundle shapes were present, those (unimodal) with a single sharp taper from longest to shortest stereocilia, and those (bimodal) with an initial steep tape-followed by a less steep taper. An additional subtype of type 1 hair cells with short hair bundles was identified. SCC hair cells have fewer hair bundles with bimodal tapers across all cell groups when compared to UTR or LAG. All cell subtypes identified for dissociated hair cells were corroborated using histologic sections.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Hansu, Osman, and Esra Mete Güneyisi. "Comparison of Novel Seismic Protection Devices to Attenuate the Earthquake Induced Energy." Actuators 10, no. 4 (April 7, 2021): 73. http://dx.doi.org/10.3390/act10040073.

Повний текст джерела

Анотація:

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as innovative seismic protection devices. For this purpose, 4-, 8- and 12-story steel bare frames were designed with 6.5 m equal span length and 4 m story height. Thereafter, they were seismically improved by mounting the VDs and BRBs in three patterns, namely outer bays, inner bays, and all bays over the frame heights. The structures were modeled using SAP 2000 software and evaluated by the nonlinear time history analyses subjected to the six natural ground motions. The seismic responses of the structures were investigated for the lateral displacement, interstory drift, absolute acceleration, maximum base shear, and time history of roof displacement. The results clearly indicated that the VDs and BRBs reduced seismic demands significantly compared to the bare frame. Moreover, the all-bay pattern performed better than the others.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Farrell, S. P., K. J. Avery, and L. W. MacGregor. "Determination of X-Ray Elastic Constants for Q1N Submarine Pressure Hull Steel." Applied Mechanics and Materials 70 (August 2011): 285–90. http://dx.doi.org/10.4028/www.scientific.net/amm.70.285.

Повний текст джерела

Анотація:

The Canadian Navy has a requirement to conduct on-site accurate residual stress investigations to improve the efficacy of risk assessment and damage tolerance analysis of critical structures. This paper describes the techniques for qualification of the portable miniature X-ray diffractometer (mXRD) for residual stress analysis on Canadian VICTORIA Class submarine (VCS) pressure hulls. The effect that thermomechanical processing has on the X-ray elastic constant (XREC) and resultant stress analysis is discussed. The approach for calibration of the mXRD equipment and calculation of residual stress values from strain measurements is explained. A new methodology for determination of the XREC, based on the ‘multiple angle method’, is presented discussed and applied to describe the stress-strain relation for tempered Q1N steel. This method, which expands on the ASTM standard, examines the change in lattice strain at multiple y angles (∂dfy/∂sin2y) and provides improved statistical error over the ASTM standard. An XREC of 195 ±6 GPa was experimentally determined for Q1N steel using the {211} crystallographic planes of bcc Fe (using Cr Kα radiation) using the multiple angle method.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Khalid, Perveiz, Shahzada Khurram, Zia Ud Din, Syed Atif Ali, and Alabjah Bahija. "Integrated Study of Geotechnical and Geophysical Methods to Assess the Soil Corrosion Potential for Construction Site." International Journal of Economic and Environmental Geology 11, no. 3 (December 4, 2020): 79–85. http://dx.doi.org/10.46660/ijeeg.vol11.iss3.2020.480.

Повний текст джерела

Анотація:

Corrosion of subsurface steel structures is very critical issue especially in moisture subsoil. The use ofphysiochemical properties such as pH, salts concentration, electrical resistivity is very common to quantify corrosivenature of subsoil. However, the laboratory measurements of these parameters are quite difficult due to time and budgetconstraints. In this work soil corrosion potential of a power plant site was evaluated using geophysical and geotechnicalinvestigations. Soil samples were collected from 15 boreholes drilled up-to 50 m depth for laboratory testing whereas 3probes of four electrodes vertical electrical sounding (VES) using Wenner configuration were also performed tomeasure the electrical resistivity of the subsurface soil up to 50 m depth. According to the USCS soil system silty clay(CL-ML) was interpreted as dominant material in all boreholes as shallow depth. Poorly graded sand (SP) including silt(SM) was found of variable depth in almost each borehole. The true resistivity values at the depth of 30 meters liesbetween the 19.9 ohm- meters to 59.8 ohm meters. All observation points of electrical resistivity survey VES-I, VES-IIand VES-III near-surface material show moderate soil corrosion potential which is favorable for design of earthing. Upto depth of 4 m, the values of resistivity 52.6 to 59.8 ohm-meters shows adequate estimation of corrosion. According tothe International standard these curves belong to bell type or K type curve of resistivity model. Their resistivity valueswith respect to depth show low to moderate corrosion potential which is satisfactory for construction at this depth afterapplying the nominal cathodic protections. Thus, electric pipe lines may be installed at this depth.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Fromherz, Aymeric, Aseem Rastogi, Nikhil Swamy, Sydney Gibson, Guido Martínez, Denis Merigoux, and Tahina Ramananandro. "Steel: proof-oriented programming in a dependently typed concurrent separation logic." Proceedings of the ACM on Programming Languages 5, ICFP (August 22, 2021): 1–30. http://dx.doi.org/10.1145/3473590.

Повний текст джерела

Анотація:

Steel is a language for developing and proving concurrent programs embedded in F ⋆ , a dependently typed programming language and proof assistant. Based on SteelCore, a concurrent separation logic (CSL) formalized in F ⋆ , our work focuses on exposing the proof rules of the logic in a form that enables programs and proofs to be effectively co-developed. Our main contributions include a new formulation of a Hoare logic of quintuples involving both separation logic and first-order logic, enabling efficient verification condition (VC) generation and proof discharge using a combination of tactics and SMT solving. We relate the VCs produced by our quintuple system to solving a system of associativity-commutativity (AC) unification constraints and develop tactics to (partially) solve these constraints using AC-matching modulo SMT-dischargeable equations. Our system is fully mechanized and implemented in F ⋆ . We evaluate it by developing several verified programs and libraries, including various sequential and concurrent linked data structures, proof libraries, and a library for 2-party session types. Our experience leads us to conclude that our system enables a mixture of automated and interactive proof, making it productive to build programs foundationally verified against a highly expressive, state-of-the-art CSL.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Jotić, Ana, Katarina Savić Vujović, Jovica Milovanović, Aleksandar Vujović, Zorana Radin, Nataša Milić, Sonja Vučković, Branislava Medić, and Milica Prostran. "Pain Management After Surgical Tonsillectomy: Is There a Favorable Analgesic?" Ear, Nose & Throat Journal 98, no. 6 (May 9, 2019): 356–61. http://dx.doi.org/10.1177/0145561319846065.

Повний текст джерела

Анотація:

The aim of this study was to examine how ibuprofen and paracetamol prevent pain after cold-steel extracapsular tonsillectomy in children. Also, we examined the relation between age, gender, nausea, postoperative bleeding, antibiotic use, type of diet, and postoperative pain intensity and the type of administered analgesic. A prospective study was conducted on 147 children (95 males and 52 females, aged 7-17 years) who underwent tonsillectomy in the Clinical-Hospital Center “Dragiša Mišović” from January 1 to June 30, 2016. The degree of pain was measured using a visual analog scale (VAS). We did not observe any significant differences in postoperative nausea, hospitalization rate postoperative bleeding, and antibiotic use between the paracetamol and ibuprofen groups. A test of within-patient effects showed that VAS scores changed significantly during the postoperative follow-up period ( P = .00), but there were no significant differences between the groups ( P = .778). After 12 hours, 29.3% of the patients on paracetamol and 21.8% on ibuprofen were transferred to a soft diet; after 24 hours, 84.8% of the paracetamol group and 85.5% of the ibuprofen group were on a soft diet (χ2test, P < .05). There was a statistically significant correlation between VAS scores measured 4 hours after the surgery and the time of transference to the soft diet (Spearman ρ test, P < .001). The transfer to soft and normal diets was not significantly different between the 2 groups as assessed by the VAS scores (Pearson χ2test, P = .565).There is still no consensus on the most effective postoperative pain-control regiment after tonsillectomy. This study showed that satisfactory pain management was achieved equally with both paracetamol and ibuprofen.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Khakimova, Evelina, H. Celik Ozyildirim, and Devin K. Harris. "Investigation of Properties of High-Performance Fiber-Reinforced Concrete: Very Early Strength, Toughness, Permeability, and Fiber Distribution." Transportation Research Record: Journal of the Transportation Research Board 2629, no. 1 (January 2017): 73–82. http://dx.doi.org/10.3141/2629-10.

Повний текст джерела

Анотація:

Concrete cracking, high permeability, and leaking joints allow harmful solutions to intrude into concrete, resulting in concrete deterioration and corrosion of reinforcement. The development of durable concrete with limited cracking is a potential solution for extending the service life of concrete structures. Optimal design of very early strength (VES) durable materials will facilitate rapid and effective repairs and thus reduce traffic interruptions and maintenance work. The purpose of this study was to develop low-cracking durable materials that could achieve a very early compressive strength of 3,000 pounds per square inch within 10 h. Various proportions of silica fume, fly ash, steel fibers, and polypropylene fibers were used to evaluate concrete durability and postcracking performance. In addition, toughness, residual strength, permeability of cracked concrete, and fiber distribution were examined. VES durable concretes could be achieved with proper attention to mixture components (amounts of portland cement and accelerating admixtures), proportions (water–cementitious material ratio), and fresh concrete and curing temperatures. Permeability values indicated that minor increases in crack width, greater than 0.1 mm, greatly increased infiltration of solutions. Adding fibers could facilitate control of crack width. An investigation of fiber distribution showed preferential alignment and some clumping of fibers in the specimens and highlighted the need for sufficient mixing and proper sequencing of the addition of concrete ingredients into the mixer to ensure a uniform random fiber distribution. Results indicated that VES and durable fiber-reinforced concrete materials could be developed to improve the condition of existing and new structures and facilitate rapid, effective repairs and construction.

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Smirnov, Alekseiy A., Sergeiy A. Silkin, Sergeiy A. Kusmanov, Pavel N. Belkin, Ilya G. Dyakov, and Varvara S. Sevostyanova. "IMPROVEMENT OF CORROSION AND WEAR RESISTANCE OF 45 STEEL WITH ANODE PLASMA ELECTROLYTE NITRIDING." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 60, no. 1 (March 1, 2017): 81. http://dx.doi.org/10.6060/tcct.2017601.5417.

Повний текст джерела

Анотація:

For citation:Smirnov A.A., Silkin S.A., Belkin P.N., Dyakov I.G., Sevostyanova V.S., Kusmanov S.A. Improvement of corrosion and wear resistance of 45 steel with anode plasma electrolyte nitriding. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 1. P. 81-86.The wear and corrosion resistance was studied after anode plasma electrolytic nitriding (PEN) the carbon steel in electrolyte containing ammonium chloride and ammonia or ammonium nitrate. Tribological properties of nitrided samples were evaluated using a pin-on-disk and ball-on-disk tribometers under lubricated testing conditions and dry sliding. The effect of processing temperature on corrosion resistance of the PEN samples was examined by means of potentiodynamic polarization in a solution of sodium sulfate (0.1 N). The anode PEN at 750 °C during 5 min in electrolyte containing ammonium chloride (15%) and ammonium nitrate (5%) results in a decrease in a corrosion current density by a factor of 16. The anode PEN at 750 °C during 10 min in electrolyte containing ammonium chloride (10%) and ammonia (5%) results in the decrease in a corrosion current density by a factor of 6. Improving the corrosion resistance of steel takes place due to the formation of the surface oxide layer and the nitride-martensite zone. Results of wear tests under lubricated testing conditions with the speed of 0.49 m/s and load of 208.6 N against hardened steel (50 HRC) diskshow that friction coefficient of nitrided samples decreases at all PEN temperatures. The anode PEN at 750 °C during 10 min in electrolyte containing ammonium chloride and ammonia results in the decrease in wear rate more than 9 times and friction coefficient from 0.17 to 0.12. Nitriding in electrolyte with ammonium chloride and nitrate also results in minimum of the wear rate after the PEN at 750 °C during 10 min but it gives lesser result due to the lower hardness of the nitride-martensite sublayer. Wear tests during dry sliding with the speed of 0.2 m/s and load of 5 N against bearing steel ballshow that friction coefficient of nitrided samples decreases from 0.41 to 0.28. The increasing the load reduces the friction coefficient that means saving mode of elastic contact and a good running-in ability of oxide layer in the studied range. Linear wear decreases from 35 to 21 mm at load of 10 N and sliding speed of 0.4 m/s.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Hamushan, Musha, Weijie Cai, Yubo Zhang, Tengfei Lou, Shaoxiang Zhang, Xiaonong Zhang, Pengfei Cheng, Changli Zhao та Pei Han. "High-purity magnesium pin enhances bone consolidation in distraction osteogenesis model through activation of the VHL/HIF-1α/VEGF signaling". Journal of Biomaterials Applications 35, № 2 (28 травня 2020): 224–36. http://dx.doi.org/10.1177/0885328220928550.

Повний текст джерела

Анотація:

Distraction osteogenesis has widespread clinical use in the treatment of large bone defects. Nonetheless, the prolonged consolidation period carries the risk of complications. Magnesium-based materials have been shown to promote bone regeneration in fracture healing both in vitro and in vivo. Here, we investigated whether high-purity magnesium could enhance bone formation in distraction osteogenesis. High-purity magnesium pins were placed into the medullary cavity in the rat distraction osteogenesis model. Results showed that the bone volume/total tissue volume, bone mineral density, and mechanical properties of new callus were significantly higher in the high-purity magnesium group compared to stainless steel and control group (p < 0.01). Histological analyses confirmed improved bone consolidation and vascularization in high-purity magnesium group. Further, polymerase chain reaction-array investigation, Western blot, and immunohistochemical results found that vascular endothelial growth factor and hypoxia inducible factor-1α were highly expressed in the high-purity magnesium group, while Von Hippel–Lindau protein was the opposite (p < 0.01). In conclusion, high-purity magnesium implants have the potential to enhance angiogenesis and bone consolidation in the distraction osteogenesis application, and this process might be via the regulation of Von Hippel–Lindau/hypoxia inducible factor-1α/vascular endothelial growth factor signaling.

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Yang, Tianye, Paolo M. Calvi, and Richard Wiebe. "Numerical implementation of variable friction sliding base isolators and preliminary experimental results." Earthquake Spectra 36, no. 2 (February 20, 2020): 767–87. http://dx.doi.org/10.1177/8755293019891721.

Повний текст джерела

Анотація:

The development of variable friction base isolation systems (VFSs) is the object of an ongoing international research project that involves extensive numerical and experimental activities. This article presents some of the recent numerical developments carried out as part of this project. More specifically, a three-dimensional (3D) variable friction (VF) element is formulated and implemented into OpenSees, providing the foundation for studying structural response in the context of nonlinear time history (NLTH) analysis. The element implementation captures the bearing bidirectional horizontal response along with horizontal–vertical coupling effects. Response predictions obtained using this newly implemented element are compared with the experimental results obtained from testing a full-scale VFS prototype, showing promising results. Finally, a demonstrative numerical study is carried out in which a steel moment resisting frame (MRF) structure, isolated using VFSs, is analyzed via NLTH analyses.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Николаев, В. И., Ю. Г. Пастернак, В. А. Пендюрин, and С. М. Фёдоров. "MULTIPATH ANTENNA SYSTEM OF THE VHF BAND BASED ON A LENS MADE OF GRANITE RUBBLE." ВЕСТНИК ВОРОНЕЖСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА, no. 6 (January 14, 2022): 100–106. http://dx.doi.org/10.36622/vstu.2021.17.6.014.

Повний текст джерела

Анотація:

Предложена конструкция приземной многолучевой антенной решетки на основе линзы из гранитного щебня, позволяющая одновременно формировать до нескольких десятков лучей в длинноволновой области УКВ-диапазона волн. Эффективная диэлектрическая проницаемость гранитного щебня оценивалась с помощью формулы Лихтенекера для мелкодисперсных смесей; ее величина приблизительно равна 3. Для оценки величины замедления поверхностных волн в линзе использовалась методика анализа дисперсионных характеристик зеркального диэлектрического волновода; при высоте линзы 1.8 метра эффективная диэлектрическая проницаемость эквивалентного зеркального диэлектрического волновода равна 2.1. В качестве облучателей линзы - несимметричные электрические вибраторы, расположенные на окружности по периметру линзы, диаметр которой составляет 30 метров; диаметр подстилающей стальной поверхности составляет 40 метров. Предложенная антенная система характеризуется потерями в щебне около 3 дБ при диаметре линзы около 3,8 длин волн; показано, что коэффициент направленного действия у каждого луча может составлять около 15,5 дБ, при ширине главного лепестка в азимутальной плоскости по уровню половинной мощности около 10 градусов We propose a design of a surface multi-beam antenna array based on a lens of crushed granite, which makes it possible to simultaneously form up to several tens of beams in the long-wave region of the VHF wave range. We estimated the effective dielectric constant of crushed granite using the Lichtenecker formula for fine mixtures; its value is approximately equal to 3. To estimate the magnitude of the deceleration of surface waves in the lens, we used a technique to analyze the dispersion characteristics of a mirror dielectric waveguide; at a lens height of 1.8 meters, the effective dielectric constant of the equivalent mirror dielectric waveguide is 2.1. As irradiators of the lens - asymmetric electric vibrators located on a circle around the perimeter of the lens, the diameter of which is 30 meters; the diameter of the underlying steel surface is 40 meters. The proposed antenna system is characterized by a loss in rubble of about 3 dB with a lens diameter of about 3.8 wavelengths; the directivity of each beam can be about 15.5 dB, with the width of the main lobe in the azimuthal plane at half power level of about 10 degrees

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Inoue, Motohiro, Hiroshi Kitakoji, Naoto Ishizaki, Munenori Tawa, Tadashi Yano, Yasukazu Katsumi, and Kenji Kawakita. "Relief of Low Back Pain Immediately after Acupuncture Treatment – a Randomised, Placebo Controlled Trial." Acupuncture in Medicine 24, no. 3 (September 2006): 103–8. http://dx.doi.org/10.1136/aim.24.3.103.

Повний текст джерела

Анотація:

Background The purpose of this study was to examine the immediate effect of single acupuncture stimulation to the most painful point in patients with low back pain. Method A randomised, evaluator-blinded, sham controlled clinical trial was conducted in which 31 patients with low back pain were randomly allocated to either an acupuncture group (n=15) or a sham acupuncture group (n=16). Both acupuncture and sham acupuncture were performed at the most painful point on the lower back of the subjects. For the acupuncture group, a stainless steel needle was inserted to a depth of 20mm and manually stimulated (sparrow pecking method) for 20 seconds, while for the sham treatment a guide tube without a needle was placed at the point and tapped on the skin. Changes in low back pain were evaluated with a visual analogue scale (VAS) and the Schober test. Participants were also asked if they felt the needling sensation or not. The therapy and the evaluation were independently performed by two different acupuncturists. Results VAS score and the Schober test score showed significant improvement after treatment as compared with the sham group (P=0.02, 0.001, respectively). There were no significant differences in the needling sensation between the acupuncture and sham group. Conclusion These results suggest that acupuncture at the most painful point gives immediate relief of low back pain.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Juhaina Alghdir and Ahmad Falah, Juhaina Alghdir and Ahmad Falah. "Preparation of Poly(aniline-co-phenol) and Study Its Properties and Its Polymerization Kinetics Using Two Methods: UV-Vis and HPLC." Journal of the chemical society of pakistan 43, no. 5 (2021): 505. http://dx.doi.org/10.52568/000602/jcsp/43.05.2021.

Повний текст джерела

Анотація:

The co-polymerization of polyaniline is one of the most important methods used to improve the electrical activity and thermal stability of polyaniline. Previously, electrochemical co-polymerization of phenol and aniline was performed on 304 stainless steel anodes. In this study, we present the co-polymerization of aniline and phenol chemically at laboratory temperature in an acidic medium with ammonium pyrosulfate as an oxidant. The Scanning Electron Microscopy (SEM) analysis of poly(aniline-co-phenol) sample shows a rough (non-smooth) surface with crystalline particles with microscopic diameters. We characterized the prepared polymer with DSC, DTA, and thermos gravimetric analysis (TGA). We found that the thermal decomposition of poly(aniline-co-phenol) was on six steps. The glass transition temperature of the co-polymer (Tg) was found at 863.89 and#176;C and the melting transition temperature was observed at 877.80 and#176;C. We studied the kinetics of Poly(aniline-co-phenol) using two methods: UV-Vis, HPLC. Then we determined the reaction order. It was found that the reaction was the zero-order reaction (n=0) in both previous two methods.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Juhaina Alghdir and Ahmad Falah, Juhaina Alghdir and Ahmad Falah. "Preparation of Poly(aniline-co-phenol) and Study Its Properties and Its Polymerization Kinetics Using Two Methods: UV-Vis and HPLC." Journal of the chemical society of pakistan 43, no. 5 (2021): 505. http://dx.doi.org/10.52568/000602.

Повний текст джерела

Анотація:

The co-polymerization of polyaniline is one of the most important methods used to improve the electrical activity and thermal stability of polyaniline. Previously, electrochemical co-polymerization of phenol and aniline was performed on 304 stainless steel anodes. In this study, we present the co-polymerization of aniline and phenol chemically at laboratory temperature in an acidic medium with ammonium pyrosulfate as an oxidant. The Scanning Electron Microscopy (SEM) analysis of poly(aniline-co-phenol) sample shows a rough (non-smooth) surface with crystalline particles with microscopic diameters. We characterized the prepared polymer with DSC, DTA, and thermos gravimetric analysis (TGA). We found that the thermal decomposition of poly(aniline-co-phenol) was on six steps. The glass transition temperature of the co-polymer (Tg) was found at 863.89 and#176;C and the melting transition temperature was observed at 877.80 and#176;C. We studied the kinetics of Poly(aniline-co-phenol) using two methods: UV-Vis, HPLC. Then we determined the reaction order. It was found that the reaction was the zero-order reaction (n=0) in both previous two methods.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Saffari, Shaya, and Farshad Akhlaghi. "New Semisolid Casting of an Al-25Wt.% Mg₂Si Composite Using Vibrating Cooling Slope." Solid State Phenomena 217-218 (September 2014): 389–96. http://dx.doi.org/10.4028/www.scientific.net/ssp.217-218.389.

Повний текст джерела

Анотація:

Al-Mg2Si composites have gained considerable attention because of their attractive properties such as low density, improved wear resistance and good castability. However, when in-situ routes are used for processing of these composites, the formation of coarse Mg2Si particles with sharp cornersis inevitable and is detrimental for the composite properties. This problem is intensified when a hypereutectic composition such as Al-25wt.% Mg2Si alloy is processed. In the present study, an innovative semisolid technique termed as the Vibrating Cooling Slope (VCS) has been applied to produce a sample of in-situ Al-25wt.% Mg2Si composite.This technique combines the conventional cooling slope and vibration casting methods into an integrated one for producing fine and globular structures in the as-cast condition. An inclined plate was prepared from a 10mm thickness copper plate and was coated by boron nitride. This platecould vibrate mechanically in the vertical direction at a predetermined frequency by the aid of four springs and an electric motor. The molten Al-16.5wt.%Mg-9.4%Sialloy with 100oC superheat was poured on the surface of this cooling slope (set at 45° inclined angle)while it was vibrating at the frequency of 40 Hzandamplitude of 400 μm.The semisolid alloy travelled the length of 40 cm on the slope before being poured into a steel mold (60 mm internal diameter and 35 mm in height). Also for the purpose of comparison, gravity casting (GC) and conventionally still cooling slope casting (CS)were carried outboth using the same mold and with the same superheat.The samples were sectioned, polished and subjected to metallographicstudies,porosity and hardness measurements. It was concluded that CS and VCS techniques resulted in a decrease in the size of Mg2Si particles by about 50%and 70% respectively when compared with the gravity casting. However, the increased shape factor of Mg2Si particles in the VCS and CS processed samples was insignificant as compared with GC. Although in comparison with GC, the VCS processed sample showed a higher porosity level, it exhibited a higher hardness value. These results were attributed to the finer and modified microstructure obtained via this newly developed technique.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Su, Tining, Baojie Yan, Laura Sivec, Guozhen Yue, Jessica Owens-Mawson, Jeffrey Yang, and Subhendu Guha. "Nanostructured Silicon Oxide Dual-Function Layer in Amorphous Silicon Based Solar Cells." MRS Proceedings 1426 (2012): 69–74. http://dx.doi.org/10.1557/opl.2012.1015.

Повний текст джерела

Анотація:

ABSTRACTWe report the results of using n-type hydrogenated nanocrystalline silicon oxide alloy (nc-SiOx:H) in hydrogenated nanocrystalline silicon (nc-Si:H) and amorphous silicon germanium alloy (a-SiGe:H) single-junction solar cells. We used VHF glow discharge to deposit nc-SiOx:H layers on various substrates for material characterizations. We also used VHF glow discharge to deposit the intrinsic layer in nc-Si:H solar cells. RF glow discharge was used for the deposition of the doped layers and the intrinsic layer in a-SiGe:H solar cells. Various substrates such as stainless steel (SS), Ag coated SS, and ZnO/Ag coated SS were used for different cell structures. We found that by using nc-SiOx:H to replace the ZnO and the a-Si:H n-layer in nc-Si:H solar cells, the cell structure is greatly simplified, while the cell performances remain nearly identical to those made using the conventional n-i-p structure on standard ZnO/Ag BR’s. Solar cells with nc-SiOx:H as the n layer directly deposited on textured Ag show similar quantum efficiency (QE) as the n-i-p cells on ZnO/Ag BRs. In both cases, QE is higher than that in the n-i-p cells made directly on Ag coated SS. This effect is probably caused by the shift of surface plasmon-polariton resonance frequency due to the difference in index of refraction of ZnO, nc-SiOx:H, and Si.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Ao, Shengxiang, Junlong Wu, Yu Tang, Chao Zhang, Jie Li, Wenjie Zheng, and Yue Zhou. "Percutaneous Endoscopic Lumbar Discectomy Assisted by O-Arm-Based Navigation Improves the Learning Curve." BioMed Research International 2019 (January 10, 2019): 1–9. http://dx.doi.org/10.1155/2019/6509409.

Повний текст джерела

Анотація:

Objective. There is a steep learning curve with traditional percutaneous endoscopic lumbar discectomy (PELD). The aim of this study is to assess the safety and efficacy of PELD assisted by O-arm-based navigation for treating lumbar disc herniation (LDH).Methods. From September of 2017 to January of 2018, 118 patients with symptomatic LDH were enrolled in the prospective cohort study. The patients undergoing PELD with O-arm-based navigation technique were defined as group A (58 cases), and those undergoing traditional X-ray fluoroscopy method were defined as group B (60 cases). We recorded the operation time, cannula placement time, radiation exposure time, visual analog scale (VAS), Oswestry Disability Index (ODI), and Macnab criteria score of the 2 groups.Results. The average operation time (95.21 ± 19.05 mins) and the cannula placement time (36.38 ± 14.67 mins) in group A were significantly reduced compared with group B (operation time, 113.83 ± 22.01 mins, P<0.001; cannula placement time, 52.63 ± 17.94 mins, P<0.001). The learning curve of PELD in group A was steeper than that in group B and was lower in the relatively flat region of the end. There were significant differences of the clinical parameters at different time points (VAS of low back, P < 0.001; VAS of leg, P < 0.001; and ODI, P < 0.001). The VAS scores for low back pain and leg pain improved significantly in both groups after surgery and gradually improved as time went by. No serious complication was observed in any patients in either group.Conclusion. The study indicated that PELD assisted by O-arm navigation is safe, accurate, and efficient for the treatment of lumbar intervertebral disc herniation. It reshaped the learning curve of PELD, reduced the difficulty of surgery, and minimized radiation exposure to surgeons. This study was registered at Chinese Clinical Trail Registry (Registration Number:ChiCTR1800019586).

Стилі APA, Harvard, Vancouver, ISO та ін.

47

BÖTTCHER, M. "THE WEBT CAMPAIGN ON 3C279 IN 2006." International Journal of Modern Physics D 17, no. 09 (September 2008): 1503–13. http://dx.doi.org/10.1142/s021827180801308x.

Повний текст джерела

Анотація:

The quasar 3C 279 was the target of an extensive multiwavelength monitoring campaign from January through April 2006, including an optical-IR-radio Whole Earth Blazar Telescope (WEBT) campaign and Target of Opportunity X-ray and soft γ-ray observations with Chandra and INTEGRAL in mid-January 2006, with additional X-ray coverage by RXTE and Swift XRT as well as independent very-high-energy (VHE) γ-ray observations by MAGIC, which led to the first-ever reported tentative detection of a quasar at VHE γ-rays. In this paper we summarize the results of the WEBT campaign. The source exhibited substantial variability of optical flux and spectral shape, with a characteristic time scale of a few days. The variability patterns throughout the optical BVRI bands were very closely correlated with each other, while there was no obvious correlation between the optical and radio variability. In intriguing contrast to other (in particular, BL Lac type) blazars, we find a lag of shorter-wavelength behind longer-wavelength variability throughout the RVB wavelength ranges, with a time delay increasing with increasing frequency. Spectral hardening during flares appears delayed with respect to a rising optical flux. This, in combination with the very steep IR-optical continuum spectral index of αo ~ 1.5 – 2.0, may indicate a highly oblique magnetic field configuration near the base of the jet, leading to inefficient particle acceleration and a very steep electron injection spectrum. An alternative explanation through a slow (time scale of several days) acceleration mechanism would require an unusually low magnetic field of B < 0.2 G , about an order of magnitude lower than inferred from previous analyses of simultaneous SEDs of 3C 279 and other FSRQs with similar properties.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Eicker, Sven O., Sascha Rhee, Hans-Jakob Steiger, Jörg Herdmann, and Frank W. Floeth. "Transtubular microsurgical approach to treating extraforaminal lumbar disc herniations." Neurosurgical Focus 35, no. 2 (August 2013): E1. http://dx.doi.org/10.3171/2013.4.focus13126.

Повний текст джерела

Анотація:

Object Approaches to treating extraforaminal lumbar disc herniations can be challenging due to the unique anatomy and the need to prevent spinal instability. Numerous approaches, including conventional midline, paramedian, minimally invasive, and full endoscopic approaches, have been described. The purposes of this study were to point out the outcome and clinical advantages of a transtubular microsurgical approach and to describe and illustrate this technique. Methods Between 2009 and 2012, a series of 51 patients underwent a minimally invasive dilative transtubular microsurgical approach for the treatment of extraforaminal lumbar disc herniations. All patients were clinically evaluated using the visual analog scale (VAS) and Oswestry Disability Index preoperatively and 6 months postoperatively. Results Both pain scores and functional status showed significant improvement after surgery (p < 0.001): radicular pain decreased from VAS score of 7.9 to one of 1.3, lower back pain from VAS score of 2.4 to 1.4, and the Oswestry Disability Index from 42.0 to 12.3. Subgroup analyses revealed no differences in outcome regarding obesity or timing of surgery (early vs late intervention). Highly significant was the correlation between preoperative radicular pain activity and timing of surgical intervention (p < 0.001). Conclusions The dilative transtubular microsurgical approach combines the advantages of the conventional open muscle-splitting approach and the endoscopic approach. The technique is easy to use with a steep learning curve. Less muscle trauma and the absence of bony resection prevent facet pain and instability, thereby contributing to a rapid recovery. Patients in this series improved excellently in the short-term follow-up.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Yoshii, I. "POS0439 THE INFLUENCE OF ESCALATED PGA SCORE ON DISEASE ACTIVITY, DAILY ACTIVITY, AND QUALITY OF LIFE, AND SOLUTION FOR OPTIMAL PGA LEVEL THAT DESERVES CLINICAL REMISSION IN PATIENT WITH RHEUMATOID ARTHRITIS." Annals of the Rheumatic Diseases 80, Suppl 1 (May 19, 2021): 448.2–448. http://dx.doi.org/10.1136/annrheumdis-2021-eular.285.

Повний текст джерела

Анотація:

Background:Patient’s global assessment (PGA) is one most difficult component as a part of disease activity index for treatment of rheumatoid arthritis (RA), that often causes an obstacle to attaining clinical remission. Moreover, PGA level affects activities in daily living.Objectives:The influence of escalated PGA score on disease activity, daily activity, and quality of life for patient with RA was investigated., and the optimal PGA level for both disease activity and daily activities was investigated from real world data.Methods:A total of 24,075 times of monitoring for RA was performed in the institute. Monitored items included TJC, SJC, PGA, EGA, CRP, and calculated values of DAS28, CDAI, SDAI, composite index of Boolean evaluation (Boolean), pain score with visual analog scale (PS-VAS), Health Assessment Questionnaire Disability Index (HAQ-DI), and quality of life score (QOLS) calculated from Euro-QOL questionnaire with 5th dimensions. Each measured item was calculated as mean value according to the PGA score, which was measured at the same time. The PGA score was classified by one increment from zero to ten. The mean values of DAS28, CDAI, SDAI, remission rate of these indices and Boolean remission rate, and mean values of PS-VAS, HAQ-DI, and QOLS were statistically evaluated.HAQ-DI below 0.5 was determined as remission (HAQ remission). Sensitivity and specificity regarding attaining HAQ remission according to each level of PGA score were calculated, and cutoff index (COI) was determined with receiver operating characteristic (ROC) curve. For PS-VAS, sensitivity and specificity of Boolean remission regarding each level of PS-VAS after classification divided by one increment was calculated, and comparable level (PS-VAS remission) was determined with reference of the curve. ROC was performed according to PGA level, and COI was determined with a same manner.Results:Number of measures counted 10428, 3099, 3110, 2346, 998, 1773, 751, 703, 655, 139, and 73 for each PGA level. PGA level from 3 to 5, and 5 to 10 were put together for number adjusting.Mean DAS28, CDAI, and SDAI demonstrated significant increase as PGA level increased, and remission rate of the all indices including Boolean demonstrated significant decrease as PGA level increases (p<0.01%). Boolean remission rate demonstrated zero percent from two, and CDAI and SDAI remission rate demonstrated zero from five, whereas DAS remission rate showed gradual decrease then zero percent was not shown in any level. Mean value of PS-VAS and HAQ-DI score demonstrated also significant decrease as PGA level increases, and QOLS demonstrated significant decrease as PGA level increases (p<0.01%). Increase of HAQ-DI score and decline of QOLS demonstrated more steep from PGA level 3, whereas no significant difference demonstrated from zero to one.HAQ remission counted 15,703, whereas no HAQ remission counted 8,335. Using ROC, COI of the PGA level was 2.0, whereas sensitivity and specificity were 63.4% and 66.3%, respectively. The estimated PS-VAS remission level was 10mm. Optimal PGA level for PS-VAS remission was set as 1.0, and sensitivity and specificity regarding PS-VAS remission were 87.1% and 71.3%, respectively.Conclusion:Increase of PGA affects daily activities and quality of life. The evident level that increases deterioration risk significantly was supposed to be from 3. Optimal level of PGA score for attaining the PS-VAS remission was 1.0, whereas the optimal PGA level for HAQ-DI remission is 1.0, despite sensitivity and specificity for the HAQ remission were lower than these for the PS-VAS remission.Disclosure of Interests:None declared

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Shibaev, Boris A., Valeriya S. Belova, and Anatoly V. Balmasov. "INFLUENCE OF ELECTROLYSIS CONDITIONS ON PARAMETERS OF PROCESS OF ELECTROCHEMICAL POLISHING OF ALLOY STEELS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 61, no. 4-5 (April 17, 2018): 64. http://dx.doi.org/10.6060/tcct.20186104-05.5665.

Повний текст джерела

Анотація:

The anodic behavior of structural alloyed steels St25Х3М3НБЦА and St30ХН2МФА in electrolytes of electrochemical polishing based on phosphoric and sulfuric acids with various additives was studied by the potentiodynamic polarization curves on a rotating disc electrode apparatus at different rotational speeds. It was established that the transpasive dissolution of steels begins at a potential more positive than the separation of oxygen, and therefore both processes proceed in parallel. The introduction of an organic additive - triethanolamine into the electrolyte composition results in a 2-fold increase in the area of transpasive dissolution compared to a solution containing chrome anhydride. The influence of processing conditions on the smoothing of the surface microrelief during electrochemical polishing is investigated. It has been established that the intensification of the hydrodynamic regime contributes to a limited growth of microroughness, but the relative smoothing of the microrelief remains insignificant. The process of anodic dissolution of the investigated steels at a moderate temperature does not ensure the achievement of the polishing effect. This is due to the high propensity to study chronology, nickel, molybdenum, vanadium. Increasing the temperature of the solution to 65-70 °C promotes the dissolution of passivation layers, Ra = 0.16 μm when using an electrolyte containing chromic anhydride and 0.08 μm in the case of a solution with triethanolamine. Thus, the addition of an organic additive to the electrolyte provides an improvement in the smoothing efficiency of the surface microrelief and a reduction in the energy input to the process, since the polishing effect is achieved with a lower current density and temperature. In addition, the replacement of chromium anhydride with triethanolamine makes the technology of surface treatment of steels more environmentally safe.Forcitation:Shibaev B.A., Belova V.S., Balmasov A.V. Influence of electrolysis conditions on parameters of process of electrochemical polishing of alloy steels. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 4-5. P. 64-71

Стилі APA, Harvard, Vancouver, ISO та ін.

Статті в журналах з теми "VHS steel"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями