Journal articles: 'SiC'

1

Verma, Ajay, J. Singh, V. Kumar, A. S. Kharab, and G. P. Singh. "Non parametric measures to estimate GxE interaction of dual purpose barley genotypes for grain yield under multi-location trials." Journal of Applied and Natural Science 9, no. 4 (December 1, 2017): 2332–37. http://dx.doi.org/10.31018/jans.v9i4.1532.

Full text

Abstract:

GxE interaction of seventeen dual purpose barley genotypes evaluated at ten major barley locations of the country by non parametric methods. Non parametric measures had been well established and expressed ad-vantages over their counter parts i.e. parametric measures. Simple descriptive measures based on the ranks of gen-otypes i.e. Mean of ranks (MR) pointed towards RD2925 and BH1008 and standard deviation of ranks (SD) for KB1401 and UPB1054 whereas Coefficient of variation (CV) for JB322 and RD2925 as stable genotypes. Nonpara-metric measures based on original values (Si1, Si2, Si3, Si4, Si5, Si6, Si7) indicated the stable performance of NDB1650, JB322 and UPB1054 while UPB1053, RD2715, RD2927 and RD2035 were observed of unstable nature. CSi1, CSi2, CSi3, CSi4, CSi5, CSi6 and CSi7 measures based on the ranks of corrected grain yield identified JB322, RD2552, RD2925 and NDB1650 as stable genotypes. Spearman’s rank correlation established highly significant positive correlation of yield with SD (0.67), Si1(0.65), Si2(0.59), Si5(0.68), Si7(0.67) whereas negative association observed for CMR (Mean of corrected ranks) (-0.62), CMed (Median of corrected ranks) (-0.60). NPi(2) expressed negative correlation with CV(-0.32), Si6 (-0.30), CMR(-0.34) and CMed(-0.48). More over NPi(3) maintained negative correlation with most of the measures though the magnitude was of low magnitude.

APA, Harvard, Vancouver, ISO, and other styles

2

Verma, Ajay, RPS Verma RPS Verma, J. Singh J Singh, Lokendra Kumar, and Gyanendra Pratap Singh. "Genotype X Environment Interactions of Fodder Barley Genotypes as Estimated by Ammi, Blup and Non Parametric Measures." Current Agriculture Research Journal 10, no. 2 (September 10, 2022): 46–54. http://dx.doi.org/10.12944/carj.10.2.02.

Full text

Abstract:

Field experiments were carried out at six locations in Northern Hill Zone to evaluate twenty three promising fodder barley genotypes in a randomized complete block design (RCBD) during 2020-21 cropping seasons . Using analytic methods Additive Main Effects and Multiplicative Interactions (AMMI), Best Linear Unbiased Predictor (BLUP) along with Non Parametric compared to decipher the GxE interactions under multi environment trials. Highly significant about 67.5% variations accounted by environments, 14.1% of GxE interactions and marginally 3.2% by the genotypes in the total sum square of variations for yield the present study. AMMI1 explained 53.7%, 32.1% by AMMI2, 6.9% for AMMI3, AMMI4 accounted for 4.8% respectivelyof a total variation. ASV and ASV1 measures considered 85.9% of the total variation identified G4, G5, G9 genotypes. MASV1 exploited 97.7% of interactions favoured for G18, G15, G8 genotypes. BLUP-based settled for G6, G11, G5 genotypes. Non parametric measures found G9, G8, G1 as suitable genotypes. Further non parametric composites measures selected G9, G4, G8 as suitable genotypes. Measures Si1, Si2, Si3, Si4, Si5,Si6 ,Si7, HMPRVG, ASV1, ASV, accounted more in first principal component whereas NPi (1), NPi (2), NPi (3), NPi (4), PRVG, Si1, GM, Mean, Average were major contributors in second principal component. Very tight positive relationships observed for IPC3, IPC1with BLUP based measures GM, HM, PRVG, HMPRVG, Average in one quadrant. CV closely related to Stdev, IPC2, IPC4 in opposite quadrant. ASV, ASV1 expressed very tight association with Si6,Si7 whereas NPi(1) , exhibited close affinity with Si1 , Si4, Si2 ,Si5 values. Methods utilized in study showed high to moderate degree of association among themselves, however non parametric measures would be recommended for multi environment trials.

APA, Harvard, Vancouver, ISO, and other styles

3

Verma, Ajay, and Gyanendra Pratap Singh. "Emulations of AMMI, BLUP and non-parametric measures to decipher GXE interaction of wheat genotypes evaluated in CZ." INTERNATIONAL JOURNAL OF AGRICULTURAL SCIENCES 18, no. 2 (June 15, 2022): 666–74. http://dx.doi.org/10.15740/has/ijas/18.2/666-674.

Full text

Abstract:

AMMI analysis observed highly significant variations due to environments, GxE interactions, and genotypes with,respective 63.2% 18.3% 5.5% towards the total sum square of variations. Absolute IPCA-1 scores pointed for G 2, G4, G7 as per IPCA-2, genotypes G8, G2 G7 would be of choice. ASV and ASV1 measures utilized 54.5% of interaction sum of squares recommended (G2, G7, G3). 96.9% of interaction effects utilized by MASV and MASV1 settled for G7, G2, G13 genotypes. BLUP-based HMGV RPGV HMRPGV measures pointed for G3, G13, G8 genotypes. Non parametric measures NPi(1) observed suitability of G13, G9 whereas NPi(2), NPi(3) NPi(4) identified G7, G10 wheat genotypes. First two significant principal components accounted for 68.5% of the total variation in the AMMI, BLUP and non-parametric measures in biplot analysis. Measures BLHM, MHPRVG, BLGM,PRVG, HM, Average, BLAvg accounted more of share in first component whereas NPi(2), NPi(3), NPi(4) Si1 ,Si2 BLStdev Si4 were major contributors for second component. Clustering analysis observed the group of average, GAI, HM and BLAvg, BLHM, BLGM, PRVG, MHPRVG measures along with second cluster of CV, BLCV, Stdev, BLStdev , IPC1 placed in one quadrant. AMMI based measures ASV, ASV1, MASV, MASV1 clustered with non-parametric measures NPi(1), Si1, Si2, Si3, Si4, Si5, Si6, Si7 in bigger cluster.

APA, Harvard, Vancouver, ISO, and other styles

4

Verma*, Ajay, Bhudev Singh Tyagi, and Gyanendra Singh. "Experimental and Biological Approaches for Genotype X Environment Interactions Estimation for Wheat Genotypes Evaluated Under Multi Locational Trials." Current Agriculture Research Journal 12, no. 1 (April 20, 2024): 242–52. http://dx.doi.org/10.12944/carj.12.1.20.

Full text

Abstract:

Genotypes VL907, HS562, HPW484 were ranked as topped three in comparison to the other during the evaluation of nine wheat genotypes at major locations of the north hills zone of the country under rain fed conditions. The least values of AMMI stability measure (ASV) had expressed the desirability of HPW484, HS562, VL2041 genotypes whereas the genotypes HS562, HPW484, VL2041 had been identified by least values of Modified Ammi Stability Value (MASV). The minimum value of simultaneous selection index measure based on the MASV (ssiMASV) had selected HS562, HPW484, VL2041 wheat genotypes while values of ssiWAASB measure found the suitability of HPW484, HS562, HS691 wheat genotypes. The composite non parametric measure NPi (2) had favoured the VL892, HS562 genotypes and values of NPi (3) measure had settled for VL892, HS562 genotypes while VL892, HPW349 wheat genotypes had been pointed by the last composite measure NPi (4). The Ward’s method of Hierarchical Clustering had placed the VL907 genotype in a separate group as compared to others. The shorter rays of measures IPC2, IPC5, IPC3, SD had reflected the less contribution of the joint effects of genotypes and measures in the biplot analysis. Non parametric composite measure NPi (1) had expressed tight direct relation with Si1,Si3,Si4,Si5,Si6,Si7 values. The values of IPC6 & IPC4 had maintained the direct association with BLUP based analytic measures HMGV, RPGV, HMPRVG*Meanb, GAI, Meanb, RPGV*Meanb values. Moreover the values of CV measure had clustered with Si2, Si3, Si4,Si5, Si7 measures of this study.

APA, Harvard, Vancouver, ISO, and other styles

5

Meena, R. P., Ajay Verma, and S. C. Tripathi. "Wheat Yield and Important Traits Influenced by Interaction of Potassium and Irrigation Levels Evaluated at Number of Locations in the Country by AMMI Analysis and Non-Parametric Measures." Environment and Ecology 41, no. 3D (September 2023): 2089–98. http://dx.doi.org/10.60151/envec/pwpy1898.

Full text

Abstract:

AMMI analysis of treatments consisted of levels of potassium with irrigations observed highly significant effects of locations, treatments, and T×L interactions for wheat yield. About 53.4% of the total variations in yield values was due to locations followed by 26.3% and 10.8% by treatments and interactions effects. Further analysis found 59.7% contributed by AMMI1 while 17.2% and 9.4% by AMMI2 and AMMI3 components for thousands grain weight as total of first two components cumulative to 76.9% of the total variation. The sums of squares for G×E signal and noise were 56.7% and 43.3% of interaction effects for grains per spike as the sum of squares of T×L signal was 2.58 times of treatments effects and IPC1 alone was 3.54 times the treatments effects. Measures ASV and ASV1 recommended T6, T5, T4 for wheat yield while measures utilized 81.6% of interaction sum of squares whereas MASV and MASV1 measures based on 98.4% identified T3, T5, T8, T4 treatments. Maximum average for thousands grains weight; GAI selected T8, T9, T6 whereas as per HM values treatments T5, T2, T8 would be more desirable. Grains per spike found the measures RPGV and HMRPGV settled for T8, T9, T5 treatments. Non parametric measures for yield observed Si1 selected T3, T2, T5 as opposed to T6, T4, T1 by Si2 values. T6, T4, T1 genotypes considered by Si3 Si4 measure considered T6, T4, T1 next Si5 for T6, T3, T4 and Si6 pointed towards T6, T4, T8 genotypes while Si7 favored T6, T1, T4 genotypes. Composite measures for thousands grains weight found NPi(1) for T3,T4,T7 while as per NPi(2) for T4,T3,T7, NPi(3) T4,T3,T2, NPi (4) found T4, T5, T7 as suitable treatment combinations. Multivariate hierarchical clustering as per Ward’s method for wheat yield observed first irrigation level with three potassium levels formed a cluster and other irrigation levels with potassium application remained in other one. At the first node of demarcation for thousands grains weight IPC5 exhibited MASV with MASV1, ASV1, IPC4, ASV, Si1 Si2 Si3 Si4 Si5 Si6 Si7 NPi(1), CV in one side and mean, GAI, PRVG, IPC1, HM, IPC1, NPi(2) NPi(3) NPi (4) on other side. The performance of treatments based on AMMI and non-parametric measures would be more meaningful for identification of suitable irrigation and potassium levels for wheat sustainable production.

APA, Harvard, Vancouver, ISO, and other styles

6

Naghma, Rahla, and Bobby Antony. "Electron impact ionization cross-section of C2, C3, Si2, Si3, SiC, SiC2and Si2C." Molecular Physics 111, no. 2 (September 11, 2012): 269–75. http://dx.doi.org/10.1080/00268976.2012.718807.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Verma, Ajay, B. S. Tyagi, and Gyanendra Singh. "Analysis of the Phenotypic Adaptability and Stability of Wheat Genotypes through the Biplot Approach." International Journal of Bio-resource and Stress Management 15, Mar, 3 (March 26, 2024): 01–09. http://dx.doi.org/10.23910/1.2024.5042.

Full text

Abstract:

The present study was conducted during the cropping season during October to April in the year 2022–23. Highly significant effects of environments, genotypes×environments interactions and genotypes had been observed as per the AMMI analysis of twelve wheat genotypes evaluated under advanced varietal trials at eleven major locations and Environments effects had augmented about 49% of the total sum of squares. ASV measure had utilized the 51.7% of the interaction effects had pointed for DBW296, HI1654, PBW899 while MASV measure had exploited nearly 98% of total interaction effects had selected the DBW296, WH1311, UP3111 genotypes as Superiority index measure also the suitability of same genotypes. The simultaneous selection index based on yield and ASV had pointed towards the HI1653, HI1654, HD3369 and genotypes HI1653, DBW397, WH1311 were identified by ssi MASV and genotypes HI1654, HD3369, HI1653 genotypes settled by ssi WAASB measure. Non parametric Si1 had pointed for DBW296, HD3369, NIAW3170 and the values of Si2 and Si3 had pointed towards DBW296, WH1311, HD3369. Composite non parametric measures First measure NPi(1) had favoured the DBW296, HI1653, HD3369 while as per NPi(2) values the DBW296, NIAW3170, PBW899 would be suitable genotypes. Out of the five clusters in the biplot analysis the ASV & WAASB had clustered with NPi(1), Si2, Si3, Si4, Si5, Si6, Si7 non parametric measures as placed in the first quadrant.

APA, Harvard, Vancouver, ISO, and other styles

8

Umeda, T., Nguyen Tien Son, Junichi Isoya, Norio Morishita, Takeshi Ohshima, Hisayoshi Itoh, and Erik Janzén. "Electron Paramagnetic Resonance Study of the HEI4/SI5 Center in 4H-SiC." Materials Science Forum 527-529 (October 2006): 543–46. http://dx.doi.org/10.4028/www.scientific.net/msf.527-529.543.

Full text

Abstract:

We present new electron-paramagnetic-resonance (EPR) data on the HEI4/SI5 center in 4H-SiC. So far, the SI5 (SI-5) center has been observed only in as-grown SiC substrates; however, we found that it can be created by electron irradiation to commercial n-type 4H-SiC. The artificially created SI5 center, which we had preliminary called HEI4, was found to be identical with the SI5 center in as-grown SiC. A high-intensity HEI4/SI5 spectrum of irradiated SiC revealed clear hyperfine structures of 29Si and 13C, which enabled us to identify the origin of this center as a carbon antisite-vacancy pair in the negative charge state (CSi-VC –). We assessed its electronic levels using photo-EPR.

APA, Harvard, Vancouver, ISO, and other styles

9

Yu, Hyun-Woo, Kati Raju, Ji Yeon Park, and Dang-Hyok Yoon. "Effects of Al2O3-RE2O3Additive for the Sintering of SiC and the Fabrication of SiCf/SiC Composites." Journal of the Korean Ceramic Society 50, no. 6 (November 30, 2013): 364–71. http://dx.doi.org/10.4191/kcers.2013.50.6.364.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Wu, Suhui, Lijian Shi, Bin Zou, Tao Zeng, Zhaoqing Dong, and Dunwang Lu. "Daily Sea Ice Concentration Product over Polar Regions Based on Brightness Temperature Data from the HY-2B SMR Sensor." Remote Sensing 15, no. 6 (March 21, 2023): 1692. http://dx.doi.org/10.3390/rs15061692.

Full text

Abstract:

Polar sea ice profoundly affects atmospheric and oceanic circulation and plays a significant role in climate change. Sea ice concentration (SIC) is a key geophysical parameter used to quantify these changes. In this study, we determined SIC products for the Arctic and Antarctic from 2019 to 2021 using data from the Chinese marine satellite Haiyang 2B (HY-2B) with an improved bootstrap algorithm. Then the results were compared with similar operational SIC products and ship-based data. Our findings demonstrate the effectiveness of the improved algorithm for accurately determining SIC in polar regions. Additionally, the results of the study demonstrate that the SIC product obtained through the improved bootstrap algorithm has a high correlation with other similar SIC products. The daily average SIC of the different products showed similar inter-annual trends for both the Arctic and Antarctic regions. Comparison of the different SIC products showed that the Arctic BT-SMR SIC was slightly lower than the BT-SSMIS and BT-AMSR2 SIC products, while the difference between Antarctic SIC products was more pronounced. The lowest MAE was between the BT-SSMIS SIC and BT-SMR SIC in both regions, while the largest MAE was between the NT-SMR and BT-SMR in the Arctic, and between the NT-SSMIS and BT-SMR in the Antarctic. The SIE and SIA time series showed consistent trends, with a greater difference in SIA than SIC and a slight difference in SIA between the BT-AMSR2 and BT-SMR in the Arctic. Evaluation of the different SIC products using ship-based observation data showed a high correlation between the BT-SMR SIC and the ship-based SIC of approximately 0.85 in the Arctic and 0.88 in the Antarctic. The time series of dynamic tie-points better reflected the seasonal variation in sea ice radiation characteristics. This study lays the foundation for the release of long-term SIC product series from the Chinese autonomous HY-2B satellite, which will ensure the continuity of polar sea ice records over the past 40 years despite potential interruptions.

APA, Harvard, Vancouver, ISO, and other styles

11

Yamaguchi, Hiroki, Yukinori Sakiyama, Emi Makino, Shoichi Onda, and Yoichiro Matsumoto. "Ab Initio Studies of the Surface Reaction of Si₂C and SiC₂ with Si on the 4H-SiC (000-1) Surface." Materials Science Forum 527-529 (October 2006): 235–38. http://dx.doi.org/10.4028/www.scientific.net/msf.527-529.235.

Full text

Abstract:

The origin of the polytypes of SiC has been investigated from the viewpoint of surface reactions by the density functional theory (DFT) within the Projector Augmented Wave-Generalized Gradient Approximation. Three radicals were considered here as the major species in the crystal growth process: Si, Si2C and SiC2. We supposed that these radicals contribute to the crystal growth directly through the adsorption on the 4H-SiC (000-1) C-face surface. The DFT calculations showed that the Si2C, which relatively has a similar structure with the SiC crystal, had no activation barrier to be adsorbed chemically to the 4H-SiC C-face surface. On the other hand, SiC2 with Si showed an activation barrier of 0.79eV to form the 4H-SiC crystal. In order to investigate the arrangements to decide polytypism in SiC, we compared the adsorption energies between the different sites, which correspond to the 4H-SiC crystal and a disordered arrangement. The activation energies had almost no difference. Our calculations indicated that these radicals do not contribute to the origin of the polytypes of SiC.

APA, Harvard, Vancouver, ISO, and other styles

12

Pandya, C. V. "Total ionization cross-sections for Si2, SiC, SiC2and Si2C molecules." Journal of Physics: Conference Series 488, no. 5 (April 10, 2014): 052001. http://dx.doi.org/10.1088/1742-6596/488/5/052001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Liu, R. J., L. M. Porter, M. J. Kim, R. W. Carpenter, and R. F. Davis. "Microstructure of Cr-B Ohmic and Rectifying Contacts on (0001) 6H Sic." Microscopy and Microanalysis 3, S2 (August 1997): 641–42. http://dx.doi.org/10.1017/s1431927600038484.

Full text

Abstract:

6H-SiC is a wide band-gap semiconductor. In recent years, a variety of high-power, -temperature, -speed and opto-electronic devices have been produced in 6H-SiC films. The future development of SiC device technology depends on the ability to form good ohmic and Schottky contacts. Plots of the current-voltage (I-V) characteristics of Cr-B contacts on (0001) 6H-SiC revealed that they became the most ohmic-like after annealing at 1000 °C for 240 sec. and rectifying after annealing for 300 sec, therefore TEM analysis of the microstructures of as-deposited and annealed Cr-B films should help in understanding what causes both the ohmic-like and rectifying behaviors.In this research, CrxBy film was deposited on vicinal (0001) 6H-SiC substrates by electron beam evaporation at room temperature. The intended phase was CrB2. Fig.l shows the microstructure of the as-deposited specimen. 6H-SiC appears to be a perfect crystal, but the Cr-B film had columnar polycrystalline microstructure.

APA, Harvard, Vancouver, ISO, and other styles

14

Liu, R. J., L. M. Porter, M. J. Kim, R. W. Carpenter, and R. F. Davis. "Microstructure of Cr-B Ohmic and Rectifying Contacts on (0001) 6H Sic." Microscopy and Microanalysis 3, S2 (August 1997): 641–42. http://dx.doi.org/10.1017/s1431927600010096.

Full text

Abstract:

6H-SiC is a wide band-gap semiconductor. In recent years, a variety of high-power, -temperature, -speed and opto-electronic devices have been produced in 6H-SiC films. The future development of SiC device technology depends on the ability to form good ohmic and Schottky contacts. Plots of the current-voltage (I-V) characteristics of Cr-B contacts on (0001) 6H-SiC revealed that they became the most ohmic-like after annealing at 1000 °C for 240 sec. and rectifying after annealing for 300 sec, therefore TEM analysis of the microstructures of as-deposited and annealed Cr-B films should help in understanding what causes both the ohmic-like and rectifying behaviors.In this research, CrxBy film was deposited on vicinal (0001) 6H-SiC substrates by electron beam evaporation at room temperature. The intended phase was CrB2. Fig.l shows the microstructure of the as-deposited specimen. 6H-SiC appears to be a perfect crystal, but the Cr-B film had columnar polycrystalline microstructure.

APA, Harvard, Vancouver, ISO, and other styles

15

Song, Jong Seob, Seyoung Kim, Kyeong Ho Baik, Sangkuk Woo, and Soo-hyun Kim. "Liquid Silicon Infiltrated SiCf/SiC Composites with Various Types of SiC Fiber." Composites Research 30, no. 2 (April 30, 2017): 77–83. http://dx.doi.org/10.7234/composres.2017.30.2.077.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Massalkhi, Sarah, M. Agúndez, J. Cernicharo, J. P. Fonfría, and M. Santander-García. "The Abundance of SiC2 in Carbon Star Envelopes." Proceedings of the International Astronomical Union 13, S332 (March 2017): 261–69. http://dx.doi.org/10.1017/s1743921317007566.

Full text

Abstract:

AbstractSilicon carbide dust grains are ubiquitous in circumstellar envelopes around C-rich AGB stars. However, the main gas-phase precursors leading to the formation of SiC dust have not yet been identified. To date, only three molecules containing an Si–C bond have been identified to have significant abundances in C-rich AGB stars: SiC2, SiC, and Si2C. The ring molecule SiC2 has been observed in a handful of evolved stars, while SiC and Si2C have only been detected in the C-star envelope IRC +10216. We aim to study how widespread and abundant SiC2, SiC, and Si2C are in envelopes around C-rich AGB stars and whether or not these species play an active role as gas-phase precursors of silicon carbide dust in the ejecta of carbon stars.

APA, Harvard, Vancouver, ISO, and other styles

17

Liang, Shuang, Jiangyuan Zeng, Zhen Li, Dejing Qiao, Ping Zhang, and Haiyun Bi. "Consistent Comparison of Remotely Sensed Sea Ice Concentration Products with ERA-Interim Reanalysis Data in Polar Regions." Remote Sensing 12, no. 18 (September 5, 2020): 2880. http://dx.doi.org/10.3390/rs12182880.

Full text

Abstract:

Sea ice concentration (SIC) plays a significant role in climate change research and ship’s navigation in polar regions. Satellite-based SIC products have become increasingly abundant in recent years; however, the uncertainty of these products still exists and needs to be further investigated. To comprehensively evaluate the consistency of the SIC derived from different SIC algorithms in long time series and the whole polar regions, we compared four passive microwave (PM) satellite SIC products with the ERA-Interim sea ice fraction dataset during the period of 2015–2018. The PM SIC products include the SSMIS/ASI, AMSR2/BT, the Chinese FY3B/NT2, and FY3C/NT2. The results show that the remotely sensed SIC products derived from different SIC algorithms are generally in good consistency. The spatial and temporal distribution of discrepancy among satellite SIC products for both Arctic and Antarctic regions are also observed. The most noticeable difference for all the four SIC products mostly occurs in summer and at the marginal ice zone, indicating that large uncertainties exist in satellite SIC products in such period and areas. The SSMIS/ASI and AMSR2/BT show relatively better consistency with ERA-Interim in the Arctic and Antarctic, respectively, but they exhibit opposite bias (dry/wet) relative to the ERA-Interim data. The sea ice extent (SIE) and sea ice area (SIA) derived from PM and ERA-Interim SIC were also compared. It is found that the difference of PM SIE and SIA varies seasonally, which is in line with that of PM SIC, and the discrepancy between PM and ERA-Interim data is larger in Arctic than in Antarctic. We also noticed that different algorithms have different performances in different regions and periods; therefore, the hybrid of multiple algorithms is a promising way to improve the accuracy of SIC retrievals. It is expected that our findings can contribute to improving the satellite SIC algorithms and thus promote the application of these useful products in global climate change studies.

APA, Harvard, Vancouver, ISO, and other styles

18

Massalkhi, S., M. Agúndez, J. Cernicharo, L. Velilla Prieto, J. R. Goicoechea, G. Quintana-Lacaci, J. P. Fonfría, J. Alcolea, and V. Bujarrabal. "Abundance of SiC2 in carbon star envelopes." Astronomy & Astrophysics 611 (March 2018): A29. http://dx.doi.org/10.1051/0004-6361/201732038.

Full text

Abstract:

Context. Silicon carbide dust is ubiquitous in circumstellar envelopes around C-rich asymptotic giant branch (AGB) stars. However, the main gas-phase precursors leading to the formation of SiC dust have not yet been identified. The most obvious candidates among the molecules containing an Si–C bond detected in C-rich AGB stars are SiC2, SiC, and Si2C. To date, the ring molecule SiC2 has been observed in a handful of evolved stars, while SiC and Si2C have only been detected in the C-star envelope IRC +10216.Aim. We aim to study how widespread and abundant SiC2, SiC, and Si2C are in envelopes around C-rich AGB stars, and whether or not these species play an active role as gas-phase precursors of silicon carbide dust in the ejecta of carbon stars.Methods. We carried out sensitive observations with the IRAM 30 m telescope of a sample of 25 C-rich AGB stars to search for emission lines of SiC2, SiC, and Si2C in the λ 2 mm band. We performed non-LTE excitation and radiative transfer calculations based on the LVG method to model the observed lines of SiC2 and to derive SiC2 fractional abundances in the observed envelopes.Results. We detect SiC2 in most of the sources, SiC in about half of them, and do not detect Si2C in any source except IRC +10216. Most of these detections are reported for the first time in this work. We find a positive correlation between the SiC and SiC2 line emission, which suggests that both species are chemically linked; the SiC radical is probably the photodissociation product of SiC2 in the external layer of the envelope. We find a clear trend where the denser the envelope, the less abundant SiC2 is. The observed trend is interpreted as evidence of efficient incorporation of SiC2 onto dust grains, a process that is favored at high densities owing to the higher rate at which collisions between particles take place.Conclusions. The observed behavior of a decline in the SiC2 abundance with increasing density strongly suggests that SiC2 is an important gas-phase precursor of SiC dust in envelopes around carbon stars.

APA, Harvard, Vancouver, ISO, and other styles

19

Hijikata, Yasuto, Hiroyuki Yaguchi, Sadafumi Yoshida, Y. Takata, K. Kobayashi, S. Shin, H. Nohira, and Takeshi Hattori. "Characterization of Oxide Films on SiC Epitaxial (000-1) Faces by Angle-Resolved Photoemission Spectroscopy Measurements Using Synchrotron Radiation." Materials Science Forum 483-485 (May 2005): 585–88. http://dx.doi.org/10.4028/www.scientific.net/msf.483-485.585.

Full text

Abstract:

Thermal oxide films on SiC epitaxial (000-1) C-faces have been characterized by angle-resolved photoemission spectroscopy (AR-PES). The structure of wet oxide/SiC C-face interface was compared with that of dry oxide/SiC C-face, as well as that of dry oxide/SiC Si-face, in order to clarify why a MOS device of SiC C-face achieved good electrical properties. The improvement in electrical properties was confirmed by AR-PES measurements, evidencing differences in binding energy between SiC and the Si4+ components in Si2p and valence band region, and in binding energy between SiC and the CHx components in C1s. The reason for the improvement in electrical property of MOS devices by use of SiC C-face are discussed in terms of depth profiles of oxide films calculated from the AR-PES results.

APA, Harvard, Vancouver, ISO, and other styles

20

Yamakawa, Kazuma, Jumpei Yoshimura, Takashi Ito, Mineji Hayakawa, Toshimitsu Hamasaki, and Satoshi Fujimi. "External Validation of the Two Newly Proposed Criteria for Assessing Coagulopathy in Sepsis." Thrombosis and Haemostasis 119, no. 02 (December 28, 2018): 203–12. http://dx.doi.org/10.1055/s-0038-1676610.

Full text

Abstract:

Background Two different criteria for evaluating coagulopathy in sepsis were recently released: sepsis-induced coagulopathy (SIC) and sepsis-associated coagulopathy (SAC). Although both use universal haemostatic markers of platelet count and pro-thrombin time, significance and usefulness of these criteria remain unclear. Objective This article validates and evaluates the significance of SIC and SAC criteria compared with the International Society on Thrombosis and Haemostasis (ISTH) overt disseminated intravascular coagulation (DIC) and Japanese Association for Acute Medicine (JAAM) DIC criteria. Methods Clinical characteristics of patients from a nationwide Japanese cohort were classified by SIC, SAC or DIC status and relations between criteria were examined. We evaluated associations between in-hospital mortality and anticoagulant therapy according to the SIC, SAC or DIC status to clarify the significance of criteria for introducing anticoagulants. Intervention effects were analysed by Cox regression analysis adjusted by propensity scoring. Results Incidences of coagulopathy diagnosed by SIC and JAAM DIC were similar, whereas those of SAC and ISTH overt DIC were about half of the former two (61.4%, 60.8% vs. 45.3%, 29.3%). Severity and mortality of all criteria were almost comparable. For validating initiation of anticoagulation, favourable effects of anticoagulant therapy were observed only in sub-sets with, and not without, coagulopathy diagnosed by all four criteria. Slight non-significant differences between anticoagulant groupings were found in ISTH overt DIC- and SAC-negative populations, suggesting that some patients even ‘without’ these criteria may benefit from anticoagulant therapy. Conclusion Newly developed SIC diagnostic criteria for coagulopathy may be valuable in detecting appropriate candidates for anticoagulant therapy in sepsis and a useful alternative to conventional DIC scoring systems.

APA, Harvard, Vancouver, ISO, and other styles

21

Park, Ji Yeon, Daejong Kim, and Weon-Ju Kim. "Fabrication of SiCf/SiC Composite by Chemical Vapor Infiltration." Composites Research 30, no. 2 (April 30, 2017): 108–15. http://dx.doi.org/10.7234/composres.2017.30.2.108.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Xu, Jian Guang, Hou An Zhang, Guo Jian Jiang, and Wen Lan Li. "Synthesis of SiC_W/(Mo,W)Si₂ Composite by the "Chemical Oven" Self-Propagating Combustion Method." Key Engineering Materials 368-372 (February 2008): 951–54. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.951.

Full text

Abstract:

SiC whisker reinforced (Mo,W)Si2 composite powder has been successfully synthesized by a novel process, named as chemical oven self-propagating high temperature synthesis (COSHS). The mixtures of Si and Ti powders were ignited as chemical oven. XRD result shows that the combustion product is mainly composed of (Mo,W)Si2 solid solution and SiC phases. SEM photo and EDS result show that SiC whisker is formed during this process. The as-prepared SiCW/(Mo,W)Si2 composite powder has been pressureless sintered. The microstructure and mechanical properties of the composite were investigated. Relative densities of the monolithic material and composite are 91.2% and 92.2%, respectively. The composite containing SiC whisker and (Mo,W)Si2 solid solution has higher Vickers hardness than monolithic MoSi2. Especially the room-temperature flexural strength of the composite is higher than that of monolithic MoSi2, from 135.5MPa for MoSi2 to 235.6MPa for composites with 10 vol.% WSi2 and 15 vol.% SiC, increased by 73.9%. The morphology of fractured surface of composite reveals the mechanism to improve flexural strength of MoSi2. The results of this work show that in situ SiCW/(Mo,W)Si2 composite powder prepared by COSHS technique could be successfully sintered via pressureless sintering process and significant improvement of room temperature flexural strength could be achieved. It could be a cost-effective process for industry in future applications.

APA, Harvard, Vancouver, ISO, and other styles

23

Piluso, Nicolo’, Massimo Camarda, Ruggero Anzalone, Andrea Severino, Silvia Scalese, and Francesco La Via. "Analysis on 3C-SiC Layer Grown on Pseudomorphic-Si/Si_1-xGe_x/Si(001) Heterostructures." Materials Science Forum 806 (October 2014): 21–25. http://dx.doi.org/10.4028/www.scientific.net/msf.806.21.

Full text

Abstract:

Micro Raman characterization has been used to determine the stress status of 3C-SiC epilayer grown on pseudomorphic-Si thin layer on Si1-xGex/Si(001). The strain conditions of the Si1-xGexfilms grown on Si(001) have been determined by the analysis of additional Silicon Raman peaks, which Raman shifts are related to the lattice parameter. Through the analysis of the Raman spectra, the correlation between the Si1-xGexfilm, the crystal quality and the stress relaxation of the 3C-SiC as a function of the Germanium fraction (x), have been evaluated. The increase of Germanium fraction determines the reduction of the voids density located at the 3C-SiC/Si interface and the relaxation of the stress within the epilayer. Moreover, the 3C-SiC crystal quality, monitored by the Full Width at Half Maximum of the TO Raman mode, remains unchanged for any Germanium fraction values.

APA, Harvard, Vancouver, ISO, and other styles

24

Weih, Petia, Henry Romanus, Thomas Stauden, Lothar Spieß, Oliver Ambacher, and Jörg Pezoldt. "Growth of 3C-(Si_1-xC_1-y)Ge_x+y Layers on 4H-SiC by Molecular Beam Epitaxy." Materials Science Forum 483-485 (May 2005): 173–76. http://dx.doi.org/10.4028/www.scientific.net/msf.483-485.173.

Full text

Abstract:

In the present work cubic 3C-(Si1-xC1-y)Gex+y solid solutions were grown at different^temperatures by molecular beam epitaxy on on-axis 4H-SiC (0001) substrates. Two different growth methods are compared in order to explore the optimal growth conditions for the incorporation of Ge into the SiC lattice during the low temperature epitaxy. For this reason simultaneous growth and migration enhanced epitaxy were used. The chemical composition of the grown layers were analyzed by energy dispersive x-ray methods during transmission electron microscopy investigations. It was found that the migration enhanced epitaxy is a more suitable technique for the formation of high quality (Si1-xC1-y)Gex+y solid solutions. Additionally, polytypes transition from 4H-SiC to 3C-SiC occurs during the growth independent of the applied growth technique.

APA, Harvard, Vancouver, ISO, and other styles

25

Takaba, Hiromitsu, Ai Sagawa, Miki Sato, Seika Ouchi, Yuko Yoshida, Yukie Hayashi, Emi Sato, et al. "Multi-Level Simulation Study of Crystal Growth and Defect Formation Processes in SiC." Materials Science Forum 600-603 (September 2008): 131–34. http://dx.doi.org/10.4028/www.scientific.net/msf.600-603.131.

Full text

Abstract:

The mechanism of layer growth as well as defect formation in the SiC crystal is fundamentally important to derive its appropriate performance. The purpose of the present study is to investigate competitive adsorption properties of growth species on the various 4H-SiC polytype surfaces. Adsorption structure and binding energy of growth species in the experimentally condition on various SiC surfaces were investigated by density functional theory. For the SiC(000-1) and SiC(0001) surfaces, the adsorption energy by DFT follows the orders C > H > Si > SiC2 > Si2C > C2H2. Furthermore, based on the DFT results, amount of adsorption of each species in the experimental pressure condition were evaluated by grand canonical Monte Carlo method. H and Si are main adsorbed species on SiC(0001) and SiC(000-1) surfaces, respectively. The ratio of amount of adsorption of Si to H was depending on the surface structure that might explain different growth rate of the surfaces.

APA, Harvard, Vancouver, ISO, and other styles

26

Arayawut, Onsuda, Teerakiat Kerdcharoen, and Chatchawal Wongchoosuk. "Structures, Electronic Properties, and Gas Permeability of 3D Pillared Silicon Carbide Nanostructures." Nanomaterials 12, no. 11 (May 30, 2022): 1869. http://dx.doi.org/10.3390/nano12111869.

Full text

Abstract:

Silicon carbide (SiC) is recognized as excellent material for high power/temperature applications with a wide-band gap semiconductor. With different structures at the nanosize scale, SiC nanomaterials offer outstanding mechanical, physical, and chemical properties leading to a variety of applications. In this work, new 3D pillared SiC nanostructures have been designed and investigated based on self-consistent charge density functional tight-binding (SCC-DFTB) including Van der Waals dispersion corrections. The structural and electronic properties of 3D pillared SiC nanostructures with effects of diameters and pillar lengths have been studied and compared with 3D pillared graphene nanostructures. The permeability of small gas molecules including H2O, CO2, N2, NO, O2, and NO2 have been demonstrated with different orientations into the 3D pillared SiC nanostructures. The promising candidate of 3D pillared SiC nanostructures for gas molecule separation application at room temperature is highlighted.

APA, Harvard, Vancouver, ISO, and other styles

27

Ahmmad, B., Y. Kitamura, Y. Kusumoto, H. Yang, and M. Abdulla-Al-Mamun. "A New Type of Solid State Solar Cell Based on Fe₂O₃, SiC and Crystal Growth Inhibitors." Journal of Scientific Research 2, no. 1 (December 25, 2009): 1–8. http://dx.doi.org/10.3329/jsr.v2i1.2660.

Full text

Abstract:

A new type of solid state solar cell is produced by using Fe2O3 (working electrode) and SiC as a hole collector (counter electrode). Two molten salts, 1-ethyl-3-methylimidazolium chloride (EMICl) and 1-butyl-3-methylimidazolium iodide (BMII) were used as crystal growth inhibitors with a SiC film. It was found that BMII shows about 10 times higher efficiency compared to an EMICI-based SiC film solar cell. Keywords: Fe2O3; SiC; Solid state solar cell; Molten salt. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v2i1.2660 J. Sci. Res. 2 (1), 1-8 (2009)

APA, Harvard, Vancouver, ISO, and other styles

28

Kim, Kang San, and Gwiy Sang Chung. "Characteristics of Porous 3C-SiC Thin Films Formed with Nitrogen Doping Concentrations." Materials Science Forum 645-648 (April 2010): 391–94. http://dx.doi.org/10.4028/www.scientific.net/msf.645-648.391.

Full text

Abstract:

This paper describes the characteristics of porous 3C-SiC with in-situ N-doping concentrations. Polycrystalline (poly) 3C-SiC thin films were deposited on p-type Si (100) substrates by APCVD using hexamethyildisilane (HMDS: Si2(CH3)6). The porous 3C-SiC (pSiC) was achieved by anodized with 380 nm UV-LED. The characteristics of the N2 doped pSiC were evaluated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and photo luminescence (PL). Average pore diameter is about 50 nm and etched area was increased with N2 doping rate. These results are attributed to decrease the crystallinity by N2 doping. The band gaps of poly 3C-SiC films and porous 3C-SiC films were 2.5 eV and 2.7 eV, respectively.

APA, Harvard, Vancouver, ISO, and other styles

29

Bauschlicher, Charles W., and Stephen R. Langhoff. "Abinitiocalculations on C2, Si2, and SiC." Journal of Chemical Physics 87, no. 5 (September 1987): 2919–24. http://dx.doi.org/10.1063/1.453080.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Schmoeckel, Julian, Ruth M. Santamaría, Roger Basner, Elisabeth Schüler, and Christian H. Splieth. "Introducing a Specific Term to Present Caries Experience in Populations with Low Caries Prevalence: Specific Affected Caries Index (SaC)." Caries Research 53, no. 5 (2019): 527–31. http://dx.doi.org/10.1159/000496932.

Full text

Abstract:

Up to now, indices like the mean dmft/DMFT and the SiC (Significant Caries Index) have been used to depict caries experience in populations with high prevalence. With the caries decline, particularly for populations with low caries levels, these indices reach their statistical limits. This paper aims to introduce a specific term, the Specific affected Caries Index (SaC) for the risk groups in populations with low caries prevalence and to illustrate its use based on the consecutive German National Oral Health Survey (GNOHS) in children. In groups with a caries prevalence less than one-third of the population, many caries-free children (DMFT = 0) are included in the SiC (risk group), which calls for a new way of illustration. Mean caries experience (DMFT), caries prevalence, the SiC and SaC were portrayed for 12-year-olds in the GNOHS from 1994/95 to 2016. The SaC describes the mean caries experience (DMFT) in the group presenting caries experience (DMFT > 0). In 12-year-old 6th graders in Germany, the mean caries experience decreased from 2.4 (1994/95) to 0.4 DMFT (2016), with a recent prevalence of 21.2% (DMFT > 0, 2016). In 2016, the mean number of affected teeth in children with DMFT > 0 (SaC) was 2.1, while the SiC including 12% DMFT-free children in the risk group was 1.3. The SiC fails to reflect the caries severity in children in a population with low caries prevalence. Therefore, the newly introduced term Specific affected Caries Index (SaC) may be used to describe accurately caries experience in caries risk children in populations presenting low caries prevalence.

APA, Harvard, Vancouver, ISO, and other styles

31

Nie, Yafei, Chengkun Li, Martin Vancoppenolle, Bin Cheng, Fabio Boeira Dias, Xianqing Lv, and Petteri Uotila. "Sensitivity of NEMO4.0-SI³ model parameters on sea ice budgets in the Southern Ocean." Geoscientific Model Development 16, no. 4 (March 2, 2023): 1395–425. http://dx.doi.org/10.5194/gmd-16-1395-2023.

Full text

Abstract:

Abstract. The seasonally dependent Antarctic sea ice concentration (SIC) budget is well observed and synthesizes many important air–sea–ice interaction processes. However, it is rarely well simulated in Earth system models, and means to tune the former are not well understood. In this study, we investigate the sensitivity of 18 key NEMO4.0-SI3 (Nucleus for European Modelling of the Ocean coupled with the Sea Ice Modelling Integrated Initiative) model parameters on modelled SIC and sea ice volume (SIV) budgets in the Southern Ocean based on a total of 449 model runs and two global sensitivity analysis methods. We found that the simulated SIC and SIV budgets are sensitive to ice strength, the thermal conductivity of snow, the number of ice categories, two parameters related to lateral melting, ice–ocean drag coefficient and air–ice drag coefficient. An optimized ice–ocean drag coefficient and air–ice drag coefficient can reduce the root-mean-square error between simulated and observed SIC budgets by about 10 %. This implies that a more accurate calculation of ice velocity is the key to optimizing the SIC budget simulation, which is unlikely to be achieved perfectly by simply tuning the model parameters in the presence of biased atmospheric forcing. Nevertheless, 10 combinations of NEMO4.0-SI3 model parameters were recommended, as they could yield better sea ice extent and SIC budgets than when using the standard values.

APA, Harvard, Vancouver, ISO, and other styles

32

Yoon, Han-Ki, Young-Ju Lee, and Yi-Hyun Park. "Application and Technology on Development of High Temperature Structure SiCf/SiC Composite Materials." Transactions of the Korean Society of Mechanical Engineers A 32, no. 11 (November 1, 2008): 1016–21. http://dx.doi.org/10.3795/ksme-a.2008.32.11.1016.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Wernecke, Andreas, Dirk Notz, Stefan Kern, and Thomas Lavergne. "Estimating the uncertainty of sea-ice area and sea-ice extent from satellite retrievals." Cryosphere 18, no. 5 (May 17, 2024): 2473–86. http://dx.doi.org/10.5194/tc-18-2473-2024.

Full text

Abstract:

Abstract. The net Arctic sea-ice area (SIA) can be estimated from the sea-ice concentration (SIC) by passive microwave measurements from satellites. To be a truly useful metric, for example of the sensitivity of the Arctic sea-ice cover to global warming, we need, however, reliable estimates of its uncertainty. Here we retrieve this uncertainty by taking into account the spatial and temporal error correlations of the underlying local sea-ice concentration products. As 1 example year, we find that in 2015 the average observational uncertainties of the SIA are 306 000 km2 for daily estimates, 275 000 km2 for weekly estimates, and 164 000 km2 for monthly estimates. The sea-ice extent (SIE) uncertainty for that year is slightly smaller, with 296 000 km2 for daily estimates, 261 000 km2 for weekly estimates, and 156 000 km2 for monthly estimates. These daily uncertainties correspond to about 7 % of the 2015 sea-ice minimum and are about half of the spread in estimated SIA and SIE from different passive microwave SIC products. This shows that random SIC errors play a role in SIA uncertainties comparable to inter-SIC-product biases. We further show that the September SIA, which is traditionally the month with the least amount of Arctic sea ice, declined by 105 000±9000 km2 a−1 for the period from 2002 to 2017. This is the first estimate of a SIA trend with an explicit representation of temporal error correlations.

APA, Harvard, Vancouver, ISO, and other styles

34

Lykken, David T. ""… In a Tumor in the Brain" [Sic! Sic! Sic!]." Contemporary Psychology: A Journal of Reviews 30, no. 11 (November 1985): 880–81. http://dx.doi.org/10.1037/023327.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Kohyama, Akira, Joon-Soo Park, and Hun-Chea Jung. "Advanced SiC fibers and SiC/SiC composites toward industrialization." Journal of Nuclear Materials 417, no. 1-3 (October 2011): 340–43. http://dx.doi.org/10.1016/j.jnucmat.2010.12.086.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Colston, Gerard, Maksym Myronov, Stephen Rhead, Vishal A. Shah, Yogesh Sharma, Phil A. Mawby, and David Leadley. "Si_1-xC_x/Si(001) Heterostructures for Use in Schottky Diode Rectifiers Demonstrating High Breakdown Voltage and Negligible Leakage Current." Materials Science Forum 821-823 (June 2015): 571–74. http://dx.doi.org/10.4028/www.scientific.net/msf.821-823.571.

Full text

Abstract:

Vertical Schottky diodes have been fabricated on low C content Si1-xCxand 3C-SiC epilayers epitaxially grown on Si(001) substrates. Significant leakage current was observed in 3C-SiC diodes under reverse bias, masking any rectifying behavior. This issue is far less pronounced in Si1-xCxbased Schottky diodes which demonstrate a clear critical breakdown. Leakage current is shown to be greater in relaxed Si1-xCxlayers. While crystalline Si1-xCxis not currently a viable material for high power electronics it is useful for assessing the impact lattice mismatch and crystalline quality has on the behavior of rectifiers.

APA, Harvard, Vancouver, ISO, and other styles

37

Tanaka, Shun Ichiro, and Chihiro Iwamoto. "Reactive Wetting Dynamics on 6H-SiC Surface with Oxide Layer." Advanced Materials Research 11-12 (February 2006): 571–74. http://dx.doi.org/10.4028/www.scientific.net/amr.11-12.571.

Full text

Abstract:

Nanoscale singularity at the reactive wetting front on the 6H-SiC (0006) surface with amorphous oxide layer was studied using video recorded in situ to clarify the dynamic atomistic behaviors of the brazing and the molten tip spreading on a high-temperature stage of a high-resolution transmission electron microscope. A 0.5-nm-thick precursor film spreading ahead of the main molten alloy on SiC (0006) at 1073 K and continuous spreading of the molten alloy were clearly observed on the SiC (0006) surface with a less than 1-nm-thick amorphous layer. Molten Ti and TiC nanolayers preceded the Ti5Si3 nanolayer at the tip and they traveled continuously at a velocity of 14 nm/sec on the plane perpendicular to SiC (0006). Since Ti atoms in the molten alloy diffuse sufficiently rapidly on the SiC surface to the tip, the formation of these layers may be the rate-determining step of spreading. Discontinuous spreading of the precursor tip on SiC (0006) with a thick amorphous film was observed in contrast to the continuous spreading on SiC with a thin film. This suggests that the spreading of the Ti molten alloy on SiC is also controlled by the dissolution of the amorphous layer.

APA, Harvard, Vancouver, ISO, and other styles

38

Sakurai, Akira, Charuni A. Gunaratne, and Paul S. Katz. "Two interconnected kernels of reciprocally inhibitory interneurons underlie alternating left-right swim motor pattern generation in the mollusk Melibe leonina." Journal of Neurophysiology 112, no. 6 (September 15, 2014): 1317–28. http://dx.doi.org/10.1152/jn.00261.2014.

Full text

Abstract:

The central pattern generator (CPG) underlying the rhythmic swimming behavior of the nudibranch Melibe leonina (Mollusca, Gastropoda, Heterobranchia) has been described as a simple half-center oscillator consisting of two reciprocally inhibitory pairs of interneurons called swim interneuron 1 (Si1) and swim interneuron 2 (Si2). In this study, we identified two additional pairs of interneurons that are part of the swim CPG: swim interneuron 3 (Si3) and swim interneuron 4 (Si4). The somata of Si3 and Si4 were both located in the pedal ganglion, near that of Si2, and both had axons that projected through the pedal commissure to the contralateral pedal ganglion. These neurons fulfilled the criteria for inclusion as members of the swim CPG: 1) they fired at a fixed phase in relation to Si1 and Si2, 2) brief changes in their activity reset the motor pattern, 3) prolonged changes in their activity altered the periodicity of the motor pattern, 4) they had monosynaptic connections with each other and with Si1 and Si2, and 5) their synaptic actions helped explain the phasing of the motor pattern. The results of this study show that the motor pattern has more complex internal dynamics than a simple left/right alternation of firing; the CPG circuit appears to be composed of two kernels of reciprocally inhibitory neurons, one consisting of Si1, Si2, and the contralateral Si4 and the other consisting of Si3. These two kernels interact with each other to produce a stable rhythmic motor pattern.

APA, Harvard, Vancouver, ISO, and other styles

39

Rugg, Kevin L., Richard E. Tressler, Charles E. Bakis, and Jacques Lamon. "Creep of SiC–SiC microcomposites." Journal of the European Ceramic Society 19, no. 13-14 (October 1999): 2285–96. http://dx.doi.org/10.1016/s0955-2219(99)00118-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Kryukov, Yakov V., Dmitry A. Pokamestov, Andrey A. Brovkin, and Evgeny V. Rogozhnikov. "Performance comparison of decoders of non-orthogonal multiple access signals considering modulation and coding schemes from LTE networks." Radioelectronics. Nanosystems. Information Technologies. 14, no. 4 (December 29, 2022): 463–72. http://dx.doi.org/10.17725/rensit.2022.14.463.

Full text

Abstract:

A comparative analysis of the performance of SL-SIC (Symbol Level - Serial Interference Cancellation) and CWL-SIC (Codeword Level-SIC) decoders of PD-NOMA (Power Doman - Non-Orthogonal Multiple Access) baseband signals in a system with two users is presented. Real signal code constructs (SCC) from the 3GPP LTE (Long Term Evolution of 3rd Generation Partnership Project) communication standard are used. The performance of CWL-SIC achievable in practice in real systems for all possible designs of a group PD-NOMA signal consisting of different pair combinations of noise-immune SCCs has been obtained. With the help of mathematical modeling, weighting power coefficients are obtained that provide the maximum average performance of the group signal for two user channels. The high efficiency of the CWL-SIC and the expediency of its use in real systems, especially in conditions of low signal-to-noise ratio, are shown.

APA, Harvard, Vancouver, ISO, and other styles

41

Yang, X. Y., G. Y. Shi, X. M. Meng, H. L. Huang, and Y. K. Wu. "Identification of a new trace 114R SiC by HREM." Acta Crystallographica Section B Structural Science 55, no. 2 (April 1, 1999): 255–57. http://dx.doi.org/10.1107/s0108768198011987.

Full text

Abstract:

Using electron diffraction patterns and high-resolution electron microscopy (HREM), a trace 114R SiC in commercial α-SiC powder (mainly 6H SiC according to X-ray diffraction) has been discovered. In a hexagonal unit cell its stacking sequence is [(33)4(34)2]3, the periodicity along the c axis is 286.14 Å and a = b = 3.073 Å. 114R belongs to the structure series of (33) n34(33) m34 predicted theoretically by Pandey & Krishna [Mater. Sci. Eng. (1975), 20, 243–249] on the basis of the faulted matrix model.

APA, Harvard, Vancouver, ISO, and other styles

42

Xue, Yanan, Jiaqian Qin, Xinyu Zhang, Mingzhen Ma, Duanwei He, and Riping Liu. "In situ high pressure synthesis of cBN-based composites." Functional Materials Letters 07, no. 04 (August 2014): 1450040. http://dx.doi.org/10.1142/s1793604714500404.

Full text

Abstract:

Vickers hardness, phase combination, elastic modulus and cutting performance of the cubic boron nitride (cBN) based composites with different cBN weight ratios sintered at high pressure and high temperature were investigated. During high-pressure sintering, reactions occurred between cBN and Ti 3 SiC 2, then new compounds, TiB 2, C 0.7 N 0.3 Ti , SiC and SiB 4 were formed, and no hBN phase was observed. Bulk modulus and hardness of the cBN composites decreased with increasing Ti 3 SiC 2 contents in raw mixture, and the highest hardness of 35.9 GPa was achieved for 95 wt.% cBN–5 wt.% Ti 3 SiC 2 composition specimen sintered at 1600°C. In addition, the present cBN-based composites exhibited good cutting performance.

APA, Harvard, Vancouver, ISO, and other styles

43

Pezoldt, Jörg, Charbel Zgheib, Thomas Stauden, Gernot Ecke, Thomas Kups, Heiko O. Jacobs, and Petia Weih. "Germanium Incorporation in Silicon Carbide Epitaxial Layers Using Molecular Beam Epitaxy on 4H-SiC Substrates." Materials Science Forum 963 (July 2019): 127–30. http://dx.doi.org/10.4028/www.scientific.net/msf.963.127.

Full text

Abstract:

Ternary (Si1-xCy)Gex+y solid solutions were grown on Si-face 4H-SiC applying atomic layer molecular beam epitaxy at low temperatures. The grown layers consist of twinned 3C-SiC revealed by cross section electron microscopy. The germanium was incorporated on silicon lattice sites as revealed by atomic location by channeling enhanced microanalysis transmission electron microscopy studies. The Ge concentration of the grown 3C-(Si1-xCy)Gex+y heteroepitaxial layers decreases with increasing growth temperatures, but exceeds the solid solubility limit.

APA, Harvard, Vancouver, ISO, and other styles

44

Tanaka, Shun Ichiro, and Chihiro Iwamoto. "Nanoscale Dynamics at Reactive Wetting Front on SiC." Materials Science Forum 502 (December 2005): 269–74. http://dx.doi.org/10.4028/www.scientific.net/msf.502.269.

Full text

Abstract:

Nanoscale singularity at the reactive wetting front on SiC (0006) was studied using video recorded in situ to clarify the dynamic atomistic behaviours of the brazing and the molten tip spreading on a high-temperature stage of a high-resolution transmission electron microscope. An atomistic process controls the wetting at the front of the spreading film where the classical macroscopic phenomenon never holds true and the singularities are observed in a precursor film. A 0.5-nm-thick precursor film spreading ahead of the main molten alloy on SiC (0006) at 1073 K and continuous spreading of the molten alloy were clearly observed on the SiC (0006) surface with a less than 1-nm-thick amorphous layer. Molten Ti and TiC nanolayers preceded the Ti5Si3 nanolayer at the tip and they traveled continuously at a velocity of 14 nm/sec on the plane perpendicular to SiC (0006). Since Ti atoms in the molten alloy diffuse sufficiently rapidly on the SiC surface to the tip, the formation of these layers may be the rate-determining step of spreading. Discontinuous spreading of the precursor tip on SiC (0006) with a thick amorphous film was observed in contrast to the continuous spreading on SiC with a thin film. This suggests that the spreading of the Ti molten alloy on SiC is also controlled by the dissolution of the amorphous layer.

APA, Harvard, Vancouver, ISO, and other styles

45

Diot, C., and V. Arnault. "Orientation Anisotropy in SiC Matrix of Unidirectional SiC/SiC Composite." Textures and Microstructures 14 (1991): 389–95. http://dx.doi.org/10.1155/tsm.14-18.389.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Snead, L. L., M. C. Osborne, R. A. Lowden, J. Strizak, R. J. Shinavski, K. L. More, W. S. Eatherly, J. Bailey, and A. M. Williams. "Low dose irradiation performance of SiC interphase SiC/SiC composites." Journal of Nuclear Materials 253, no. 1-3 (March 1998): 20–30. http://dx.doi.org/10.1016/s0022-3115(97)00321-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Liu, Zaidong, Yalei Wang, Xiang Xiong, Zhiyong Ye, Quanyuan Long, Jinming Wang, Tongqi Li, and Congcong Liu. "Microstructure and Ablation Behavior of C/C-SiC-(ZrxHf1−x)C Composites Prepared by Reactive Melt Infiltration Method." Materials 16, no. 5 (March 6, 2023): 2120. http://dx.doi.org/10.3390/ma16052120.

Full text

Abstract:

C/C-SiC-(ZrxHf1−x)C composites were prepared by the reactive melt infiltration method. The microstructure of the porous C/C skeleton and the C/C-SiC-(ZrxHf1−x)C composites, as well as the structural evolution and ablation behavior of the C/C-SiC-(ZrxHf1−x)C composites, were systematically investigated. The results show that the C/C-SiC-(ZrxHf1−x)C composites were mainly composed of carbon fiber, carbon matrix, SiC ceramic, (ZrxHf1−x)C and (ZrxHf1−x)Si2 solid solutions. The refinement of the pore structure is beneficial to promote the formation of (ZrxHf1−x)C ceramic. The C/C-SiC-(ZrxHf1−x)C composites exhibited outstanding ablation resistance under an air–plasma environment at around 2000 °C. After ablation for 60 s, CMC-1 appeared to possess the minimum mass and linear ablation rates of only 2.696 mg/s and −0.814 µm/s, respectively, which are lower than those of CMC-2 and CMC-3. During the ablation process, a Bi-liquid phase and a liquid–solid two-phase structure were formed on the ablation surface which could act as an oxygen diffusion barrier to retard further ablation, which is responsible for the excellent ablation resistance of the C/C-SiC-(ZrxHf1−x)C composites.

APA, Harvard, Vancouver, ISO, and other styles

48

Mahim, Z., Nurul Razliana Abdul Razak, Mohd Arif Anuar Mohd Salleh, and Norainiza Saud. "Enhancement of Microstructural and Physical Properties of Sn-0.7Cu Lead-Free Solder with the Addition of SiC Particles." Solid State Phenomena 280 (August 2018): 181–86. http://dx.doi.org/10.4028/www.scientific.net/ssp.280.181.

Full text

Abstract:

Nowadays, composite solder has gained researcher’s attention due to its promising improvement in physical and mechanical properties for lead-free solder. To improve the properties of Sn-0.7Cu (SnCu): the promising lead-free candidate, addition of silicon carbide (SiC) as a reinforcement was used into this study. However, its limitation on solderability as compared with SnAgCu (SAC) make it not an attractive alternative lead-free solder. This study was carried out to investigate the effect of SiC particle on microstructure evolution and physical properties of SnCu based solder alloys. SnCu-SiC composite solders were synthesized by powder metallurgy method (PM), which consists of several processes such as mechanical blending, compaction and sintering. Five different weight percentages of SiC particle; 0.00, 0.25, 0.50, 0.75 and 1.00 were mechanically blended with SnCu lead-free solder. The result shows that the addition of SiC particle has decreased the β-Sn area and refined the microstructure of composite solder. In addition, the improvement in microhardness of composite was achieved.

APA, Harvard, Vancouver, ISO, and other styles

49

Sun, Xinnan, Xiaowei Yin, Xiaomeng Fan, Xiaokang Ma, Xiaoyu Cao, Laifei Cheng, and Litong Zhang. "Oxidation resistance of SiC/SiC composites containing SiBC matrix fabricated by liquid silicon infiltration." Journal of the European Ceramic Society 38, no. 2 (February 2018): 479–85. http://dx.doi.org/10.1016/j.jeurceramsoc.2017.09.004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Boakye, Emmanuel E., Pavel Mogilevsky, Triplicane A. Parthasarathy, Kristin A. Keller, Randall S. Hay, and Michael K. Cinibulk. "Processing and Testing of RE2 Si2 O7 Fiber-Matrix Interphases for SiC-SiC Composites." Journal of the American Ceramic Society 99, no. 2 (October 17, 2015): 415–23. http://dx.doi.org/10.1111/jace.13935.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'SiC'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles