scholarly journals Onset of planet formation in the warm inner disk

2019 ◽  
Vol 629 ◽  
pp. A66 ◽  
Author(s):  
Tunahan Demirci ◽  
Corinna Krause ◽  
Jens Teiser ◽  
Gerhard Wurm
Keyword(s):  
Size Distribution ◽  
Room Temperature ◽  
Filling Factor ◽  
Planet Formation ◽  
Protoplanetary Disks ◽  
The Other ◽  
Sticking Probability ◽  
Wide Range ◽  
First Time ◽  
Wide Size Distribution

Aims. Collisional growth of dust occurs in all regions of protoplanetary disks with certain materials dominating between various condensation lines. The sticking properties of the prevalent dust species depend on the specific temperatures. The inner disk is the realm of silicates spanning a wide range of temperatures from room temperature up to sublimation beyond 1500 K. Methods. For the first time, we carried out laboratory collision experiments with hot levitated basalt dust aggregates of 1 mm in size. The aggregates are compact with a filling factor of 0.37 ± 0.06. The constituent grains have a wide size distribution that peaks at about 0.6 μm. Temperatures in the experiments are varied between approximately 600 and 1100 K. Results. Collisions are slow with velocities between 0.002 and 0.15 m s−1, i.e., relevant for protoplanetary disks. Aside from variations of the coefficients of restitution due to varying collision velocities, the experiments show low sticking probability below 900 K and an increasing sticking probability starting at 900 K. Conclusions. This implies that dust can grow to larger size in hot regions, which might change planet formation. One scenario is an enhanced probability for local planetesimal formation. Another scenario is a reduction of planetesimal formation as larger grains are more readily removed as a consequence of radial drift. However, the increased growth at high temperatures likely changes planetesimal formation one way or the other.

Diversification of α–Ketoamides via Transamidation Reactions with Alkyl and Benzyl Amines at Room Temperature

2021 ◽  
Author(s):  
Shweta Singh ◽  
Sureshbabu Popuri ◽  
Qazi Mohammad Junaid ◽  
Sabiah Shahul Hameed ◽  
Jeyakumar Kandasamy
Keyword(s):  
Room Temperature ◽  
The Other ◽  
Alkyl Amines ◽  
Other Hand ◽  
Wide Range

A wide range of N-tosyl α–ketoamides underwent transamidation with various alkyl amines in the absence of catalyst, base, or additives. On the other hand, transamidation in N-Boc α–ketoamides is achieved...

InAsSbBi and InSbBi: Potential Material Systems for Infrared Detection

1986 ◽  
Vol 90 ◽  
Author(s):  
S. M. Bedair ◽  
T. P. Humphreys ◽  
P. K. Chaing ◽  
T. Katsuyama
Keyword(s):  
Infrared Detectors ◽  
Room Temperature ◽  
Infrared Detection ◽  
Electrical Measurements ◽  
Quaternary Alloys ◽  
Mocvd Growth ◽  
Wide Range ◽  
Metallic Bismuth ◽  
Bismuth Antimony ◽  
First Time

ABSTRACTInSb1−x Bix (0.01 < × < 0.14) and InAsSbBi quaternary alloys are potentially attractive materials for the development of semiconductor infrared detectors covering the 8–14 μm range [1,2,3].We report for the first time, MOCVD growth of InSo1−x Bix (0.01 < × < 0.14) and InAs1−x−y Sbx Biy with 0.5 < × < 0.7 and 0.01 < y < 0.04 on both GaAs and InSb substrates using AsH3, TMSb, TEI and TMBi. Electrical measurements of the undoped InSo0.99 Bi0.01 shows a background carrier concentration of approximately 1016/cm3 and a room temperature mobility of 20,215 cm2/V.sec. To-date, these are the best reported electrical measurements for this ternary alloy.The formation of a secondary Bi phase and single crystal growth of metallic bismuth-antimony at the surface of InSo1−x Bix which results in deterioration of morphology with increasing values of x is also investigated. A wide range of analytic techniques, including SEM, EDX, electron microprobe and AES have been employed in our surface analysis.

Smart Heterostructures Based on Solid Solution ZnCdHgTe

2003 ◽  
Vol 785 ◽  
Author(s):  
Galina M. Khlyap ◽  
Petro G. Sydorchuk ◽  
Jacek Polit ◽  
Macej Oszwaldowsky
Keyword(s):  
Thin Films ◽  
Solid Solution ◽  
Spectral Range ◽  
Room Temperature ◽  
Signal Frequency ◽  
Applied Bias ◽  
Current Voltage ◽  
Wide Range ◽  
Capacitance Voltage ◽  
First Time

ABSTRACTCurrent – voltage (IVC) and capacitance – voltage (CVC) of heterostructures (Cd, Zn)Te/ZnCdHgTe are studied for the first time. Thin films ZnxCdyHg1-x-yTe were grown on monocrystalline (111) CdTe and ZnTe substrates by PLE technology. Deposition was carried out on substrates held at temperatures near 290 K. The thickness of investigated films was estimated to be about 5 μm. Electric characteristics of the as-grown structures were examined under T = 77–290 K in the wide range of applied bias. All investigated samples have demonstrated diode-like IVC and CVC under test signal frequency f = 1 kHz. Heterostructures CdTe/ZnCdHgTe have exhibited a room temperature photosensitivity in spectral range 0.50–0.65 μm.

scholarly journals AuBr3-catalyzed azidation of per-O-acetylated and per-O-benzoylated sugars

2018 ◽  
Vol 14 ◽  
pp. 682-687 ◽  
Author(s):  
Jayashree Rajput ◽  
Srinivas Hotha ◽  
Madhuri Vangala
Keyword(s):  
Room Temperature ◽  
Wide Range ◽  
First Time

Herein we report, for the first time, the successful anomeric azidation of per-O-acetylated and per-O-benzoylated sugars by catalytic amounts of oxophilic AuBr3 in good to excellent yields. The method is applicable to a wide range of easily accessible per-O-acetylated and per-O-benzoylated sugars. While reaction with per-O-acetylated and per-O-benzoylated monosaccharides was complete within 1–3 h at room temperature, the per-O-benzoylated disaccharides needed 2–3 h of heating at 55 °C.

Effect of Ammonia on the SiO2 Colloidal Particles Synthesized by the Stöber Method

2017 ◽  
Vol 865 ◽  
pp. 25-29 ◽  
Author(s):  
Yun Gao Cai ◽  
Xin Qi Li
Keyword(s):  
Size Distribution ◽  
Room Temperature ◽  
Colloidal Particles ◽  
Size Range ◽  
Tetraethyl Orthosilicate ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Result Show ◽  
Scanning Electron

Various sizes SiO2 colloidal particles in the size range of 260-950 nm were synthesized by the stöber method by adjusting the amount of ammonia from 9.0 ml to 3.0 ml while keeping 20.0 ml tetraethyl orthosilicate (TEOS), 125.0 ml ethanol, 6.0 ml ammonia and 18.0 ml distilled water fixed. In addition, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to analyze the crystallinity and morphology of the synthesized SiO2 colloidal particles; the XRD result show that the SiO2 colloidal particles are amorphous at room temperature; the SEM results demonstrated that the amount of ammonia could have significant effects on the size, size distribution and sphericity of the SiO2 colloidal particles. SiO2 colloidal particles were resulted with good monodispersity when the amount of ammonia was in the range of 6.0-90 ml, while SiO2 colloidal particles with double size distribution were obtained when the range is 3.0-4.5 ml; on the other hand, SiO2 spheres were resulted with good sphericity when the ammonia is in the range of 6.0-7.5 ml.

Recent developments in arylation of N-nucleophiles via Chan-Lam reaction: updates from 2012 onwards

2021 ◽  
Vol 17 ◽  
Author(s):  
Fahimeh Abedinifar ◽  
Mohammad Mahdavi ◽  
Elham babazadeh Rezaei ◽  
Mehdi Asadi ◽  
Bagher Larijani
Keyword(s):  
Organic Synthesis ◽  
Room Temperature ◽  
Cross Coupling ◽  
Recent Decade ◽  
Boronic Acids ◽  
Research Progress ◽  
Wide Range ◽  
Recent Developments ◽  
Comprehensive Survey ◽  
First Time

: ''Chan-Evans-Lam'' (CEL) reaction is the copper-mediated cross-coupling of N-nucleophiles with boronic acids that was independently reported in 1998 by Chan, Evans, and Lam for the first time. This reaction is accomplished at room temperature with a remarkably wide range of nucleophiles. In the recent decade, it has been particularly attractive as a convenient method for constructing the various C–N bonds in organic synthesis. Therefore, a comprehensive survey through all reported process was crucial. In this review, we summarized research progress about N-Arylation, based on the type of N-nucleophile involved in this reaction and catalysts from 2012 onwards.

New method and treatment technique applied to interband transition in GaAs1−x Px ternary alloys

Open Physics ◽  
2011 ◽  
Vol 9 (3) ◽  
Author(s):  
Cristina-Mihaela Băleanu ◽  
Raoul Nigmatullin ◽  
Saime Cetin ◽  
Dumitru Băleanu ◽  
Suleyman Ozcelik
Keyword(s):  
Room Temperature ◽  
Interband Transition ◽  
The Other ◽  
Ternary Alloys ◽  
New Method ◽  
Treatment Technique ◽  
Nonlinear Fitting ◽  
Wide Range ◽  
Fitting Parameters ◽  
Good Agreement

AbstractIn this paper we presented a new method (Eigen-Coordinates (ECs)) that can be used for calculations of the critical points (CPs) energy of the interband-transition edges of the heterostructures. This new method is more accurate and complete in comparison with conventional ones and has a wide range of application for the calculation of the fitting parameters related to nontrivial functions that initially have nonlinear fitting parameters that are difficult to evaluate. The new method was applied to determine the CPs energies from the dielectric functions of the MBE grown GaAs1−xPx ternary alloys obtained using spectroscopic ellipsometry (SE) measurements at room temperature in the 0.5-5 eV photon energy region. The obtained results are in good agreement with the results of the other methods.

scholarly journals The Fabrication of the Infrared CdSe Doped With Cu Photodetector

2016 ◽  
Vol 8 (3) ◽  
pp. 96
Author(s):  
Hassan H. Mohammed ◽  
Salwan K. J. AL-Ani
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Visible Region ◽  
Film Structure ◽  
Electromagnetic Spectrum ◽  
Wide Range ◽  
Implementation Method ◽  
First Time

In this work, the implementation method of the CdSe doped with Cu (CdSe: Cu) photodetector is presented. This detector is prepared by vacuum evaporation of CdSe films on glass substrate followed by vacuum annealing under an argon atmosphere for doping with copper. This detector is found, for the first time, to cover a wide range of the infrared besides the visible region of the electromagnetic spectrum. This finding of the wavelength tuning is due to the localized energy states of copper atoms inside the band gap of the CdSe. This tuning is compared with recent work in the corresponding colloidal CdSe-ZnS core shell quantum dots and with the quantum well (QWIR) and quantum dots (QDIR) infrared detectors. The major significance of this developed detector is in its synthesis simplicity and its fabrication processes costs in comparison with that of the (QWIR) and (QDIR) detectors. The structural analysis results demonstrated that the vacuum annealing in competition with the doping concentration improves significantly the film structure. Better crystalline structure was reported at 5 wt% of Cu concentration and at annealing temperature of 350 ºC. Besides the measured detectivity at room temperature is D*=2.31×108 cm Hz1/2W-1. This value approaches the detectivity of the state of art mercury cadmium telluride (MCT). This result paves the way for further investigations and improvements.

scholarly journals “…Into the fighting ranks of the Revolutionary Communist Party”: Admission of Former Socialists to the RSDLP(b) – RCP(b) (1917-1924)

2020 ◽  
Vol 19 (8) ◽  
pp. 79-91
Author(s):  
Tatyana I. Morozova ◽  
Vladimir I. Shishkin
Keyword(s):  
Social Work ◽  
Communist Party ◽  
Small Groups ◽  
Scientific Knowledge ◽  
The Other ◽  
Extensive Experience ◽  
Social Democratic ◽  
Wide Range ◽  
The Subject ◽  
First Time

The article analyzes one of the problems of inter-party interaction in Russia in 1917–1924, which was not studies either intentionally or occasionally by Russian or foreign scholars. The subject of the research is the admission of socialists, who quit other parties, to the RSDLP(b) - RCP(b): more specifically who resigned the membership of Russian Social Democratic Labour Party (of Internationalists), Mensheviks, Right and Left wings of Party of Socialist-Revolutionaries, Socialist-Revolutionaries-autonomists, Union of Socialists-Revolutionaries Maximalists, Party of Revolutionary Communism, anarchists and so on. Based on the wide range of published materials, including data from the central and local periodicals, as well as unique archival sources that were added to the ever-growing aggregate of scientific knowledge for the first time, the article investigate, when, how and on what conditions former members of socialist parties (so-called “vykhodets”) were accepted for the RSDLP(b) – RCP(b) membership. The authors conclude that during 1917-1924 the conditions of admitting to Bolshevik Party changed crucially. At different moments, the Communist leadership solved different problems allowing former socialists to join the Bolshevik ranks. In 1917-1919 the admission of former socialists was initiated in order to rise the number of members of the RSDLP(b) - RCP(b), and the target audience mainly consisted of revolutionaries who had extensive experience in party and social work. After the October Revolution in 1917, the entering former members of the other parties to the Bolshevik party was considered as a tool of splitting and fragmentation of socialist parties and groups that were opponents and / or competitor for the Bolsheviks. Since the end of 1919, the admission of socialists to the RCP(b) had been gradually lost its significance as a source of recruiting and transformed mainly into an instrument for the destruction of the Mensheviks and Party of Socialist-Revolutionaries, as well as a mechanism for the adoption and incorporation of small groups with socialist and communist orientation. Since 1921, the admission of former socialists to the RCP(b) actually ceased to play the role into the process of increasing membership, but became one of the most important implement of degrading and defeating the Mensheviks and Party of Socialist-Revolutionaries. From the beginning of 1924, it was used exclusively as a factor of discrediting the socialists.

scholarly journals Benzoyl Peroxide Oxidation Route to the Synthesis of Solvent Soluble Polycarbazole

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Rajender Boddula ◽  
Palaniappan Srinivasan
Keyword(s):  
Thermal Stability ◽  
Emulsion Polymerization ◽  
Benzoyl Peroxide ◽  
Room Temperature ◽  
The Other ◽  
Solution Polymerization ◽  
Peroxide Oxidation ◽  
Polar Solvents ◽  
Amorphous Nature ◽  
First Time

Carbazole was oxidized by benzoyl peroxide in presence of p-toluenesulfonic acid to polycarbazole salt at room temperature for the first time. Polycarbazole salts were synthesized via solution and emulsion polymerization pathways. Polycarbazole bases were prepared by dedoping from polycarbazole salts. Formation of polycarbazoles was confirmed from infrared, electronic absorption and EDAX spectra. Polycarbazole salt was obtained in amorphous nature in semiconductor range (10−5 S/cm), which was found to be soluble in less and high polar solvents. Polycarbazole salt prepared by emulsion polymerization pathway showed mixture of shapes with microrod, sphere, and pores, whereas its corresponding base showed only micropores structure. On the other hand, polycarbazole salt and its corresponding base prepared by solution polymerization pathway showed flake-like morphology. Higher thermal stability was obtained for polycarbazole salt prepared by emulsion polymerization pathway than that of the salt prepared by solution polymerization pathway.

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