Effects of catalyst droplets on wire growth and the resulting branched structures during VLS growth

This work deals with the selective heteroepitaxial growth of silicon carbide on (100) diamond substrates using the Vapour-Liquid-Solid (VLS) transport. The morphology, the structure and doping were determined using various characterization techniques. In order to achieve succesful heteroepitaxy, the diamond surface was silicided by solid-state reaction between a silicon layer and the substrate at 1350 °C. This allowed forming a SiC buffer layer on which p-doped 3C-SiC(100) islands elongated in the <110> directions were obtained after VLS growth. The influence of the experimental parameters on the epitaxial growth is discussed.

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VLS Growth of Si nanowhiskers on a H-terminated Si{111} surface

MRS Proceedings ◽

10.1557/proc-536-305 ◽

1998 ◽

Vol 536 ◽

Cited By ~ 1

Author(s):

N. Ozaki ◽

Y. Ohno ◽

S. Takeda ◽

M. Hirata

Keyword(s):

High Pressure ◽

Growth Condition ◽

Growth Mechanism ◽

Quantum Confinement ◽

Critical Value ◽

Extended Defects ◽

Vapor Liquid Solid ◽

Minimum Diameter ◽

Vls Growth ◽

Vapor Liquid

AbstractWe have grown Si nanowhiskers on a Si{1111} surface via the vapor-liquid-solid (VLS) mechanism. The minimum diameter of the crystalline is 3nm and is close to the critical value for the effect of quantum confinement. We have found that many whiskers grow epitaxially or non-epitaxially on the substrate along the 〈112〉 direction as well as the 〈111〉 direction.In our growth procedure, we first deposited gold on a H-terminated Si{111} surface and prepared the molten catalysts of Au and Si at 500°C. Under the flow of high pressure silane gas, we have succeeded in producing the nanowhiskers without any extended defects. We present the details of the growth condition and discuss the growth mechanism of the nanowhiskers extending along the 〈112〉 direction.

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The use of insoluble matter of Moroccan oil shale for removal of dyes from aqueous solution

10.31221/osf.io/x4v9p ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Methylene Blue ◽

Oil Shale ◽

Heating Temperature ◽

Blue Dye ◽

Adsorption Capacities ◽

Experimental Parameters ◽

Initial Ph ◽

New Material ◽

Activating Agent ◽

Moderate Cost

The study aims to use an adsorbent natural based of Moroccan oil shale of Timahdit area (Y layer) in a physical-chemical adsorption process for treating industrial discharges colorful. The used adsorbent is the insoluble party of the sub-critical extraction of decarbonized oil shale of Timahdit. The tests performed on the methylene blue (MB), showed a strong elimination in the first 10 minutes. The influences of various experimental parameters were studied: mass ratio of adsorbent, time and temperature of thermal treatment, contact time, pH of MB and heating temperature of solution on the parameters of material were studied. The experimental results have shown that the adsorption of methylene blue dye by the adsorbent is more than 90% at initial pH a range 6-7 at room temperature for 30 minutes. The process is simple and the adsorbent produced is a new material with interesting adsorption capacities of moderate cost which does not require an activating agent and can be used as industrial adsorbent for the decontamination of effluents containing organic pollutants.

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Optimization of Extraction Parameters of Reverse Iontophoretic Determination of Blood Glucose in an Artificial Skin Model

Current Analytical Chemistry ◽

10.2174/1573411015666190710232858 ◽

2020 ◽

Vol 16 (6) ◽

pp. 722-737

Author(s):

Cigdem Yengin ◽

Emrah Kilinc ◽

Fatma Gulay Der ◽

Mehmet Can Sezgin ◽

Ilayda Alcin

Keyword(s):

Ionic Strength ◽

Body Fluids ◽

Extraction Time ◽

Artificial Skin ◽

Dialysis Membrane ◽

Skin Model ◽

Non Invasive ◽

Electrode Distance ◽

Experimental Parameters

Background: Reverse İontophoresis (RI) is one of the promising non-invasive technologies. It relies on the transition of low magnitude current through the skin and thus glucose measurement becomes possible as it is extracted from the surface during this porter current flow. Objective: This paper deals with the development and optimization of an RI determination method for glucose. CE dialysis membrane based artificial skin model was developed and the dependence of RI extraction on various experimental parameters was investigated. Method: Dependence of RI extraction performance on noble electrodes (platinum, silver, palladium, ruthenium, rhodium) was checked with CA, CV and DPV, in a wide pH and ionic strength range. Optimizations on inter-electrode distance, potential type and magnitude, extraction time, gel type, membrane MWCO, usage frequency, pretreatment, artificial body fluids were performed. Results: According to the optimized results, the inter-electrode distance was 7.0 mm and silver was the optimum noble metal. Optimum pH and ionic strength were achieved with 0.05M PBS at pH 7.4. Higher glucose yields were obtained with DPV, while CA and CV achieved almost the same levels. During CA, +0.5V achieved the highest glucose yield and higher potential even caused a decrease. Glucose levels could be monitored for 24 hours. CMC gel was the optimum collection media. Pretreated CE membrane with 12kD MWCO was the artificial skin model. Pretreatment affected the yields while its condition caused no significant difference. Except PBS solution (simulated as artificial plasma), among the various artificial simulated body fluids, intestinal juice formulation (AI) and urine formulation U2 were the optimum extraction media, respectively. Conclusion: In this study, various experimental parameters (pretereatment procedure, type and MWCO values of membranes, inter-electrode distance, electrode material, extraction medium solvents, ionic strength and pH, collection medium gel type, extraction potential type and magnitude, extraction time and etc) were optimized for the non-invasive RI determination of glucose in a CE dialysis membrane-based artificial skin model and various simulated artificial body fluids.

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Effect of Experimental Parameters on Wear Response of Thermally Sprayed Carbide Based Coatings

Materials Research ◽

10.1590/1980-5373-mr-2018-0475 ◽

2018 ◽

Vol 22 (1) ◽

Cited By ~ 4

Author(s):

Nitesh Vashishtha ◽

Sanjay Sapate

Keyword(s):

Experimental Parameters ◽

Wear Response ◽

Thermally Sprayed

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Laser Floating Zone Growth: Overview, Singular Materials, Broad Applications, and Future Perspectives

Crystals ◽

10.3390/cryst11010038 ◽

2020 ◽

Vol 11 (1) ◽

pp. 38

Author(s):

Francisco Rey-García ◽

Rafael Ibáñez ◽

Luis Alberto Angurel ◽

Florinda M. Costa ◽

Germán F. de la Fuente

Keyword(s):

Equilibrium Phase ◽

Polycrystalline Materials ◽

Floating Zone ◽

High Crystalline Quality ◽

Experimental Parameters ◽

Phase Selectivity ◽

Oriented Polycrystalline ◽

Laser Heated ◽

Lfz Technique ◽

Zone Growth

The Laser Floating Zone (LFZ) technique, also known as Laser-Heated Pedestal Growth (LHPG), has been developed throughout the last several decades as a simple, fast, and crucible-free method for growing high-crystalline-quality materials, particularly when compared to the more conventional Verneuil, Bridgman–Stockbarger, and Czochralski methods. Multiple worldwide efforts have, over the years, enabled the growth of highly oriented polycrystalline and single-crystal high-melting materials. This work attempted to critically review the most representative advancements in LFZ apparatus and experimental parameters that enable the growth of high-quality polycrystalline materials and single crystals, along with the most commonly produced materials and their relevant physical properties. Emphasis will be given to materials for photonics and optics, as well as for electrical applications, particularly superconducting and thermoelectric materials, and to the growth of metastable phases. Concomitantly, an analysis was carried out on how LFZ may contribute to further understanding equilibrium vs. non-equilibrium phase selectivity, as well as its potential to achieve or contribute to future developments in the growth of crystals for emerging applications.

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Synthetic routes to manganese oxoborate and correlations between experimental parameters and properties

Ceramics International ◽

10.1016/j.ceramint.2021.03.049 ◽

2021 ◽

Author(s):

O. Icten ◽

G. Ozgenc ◽

D. Ozer ◽

D.A. Kose ◽

G. Elmaci ◽

...

Keyword(s):

Experimental Parameters ◽

Synthetic Routes

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Device-independent quantum key distribution with random key basis

Nature Communications ◽

10.1038/s41467-021-23147-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

René Schwonnek ◽

Koon Tong Goh ◽

Ignatius W. Primaatmaja ◽

Ernest Y.-Z. Tan ◽

Ramona Wolf ◽

...

Keyword(s):

Quantum Key Distribution ◽

Bell Inequality ◽

Key Distribution ◽

Theory And Practice ◽

Information Theoretic ◽

Information Theoretic Security ◽

Experimental Parameters ◽

Secret Keys ◽

Simple Variant ◽

First Time

AbstractDevice-independent quantum key distribution (DIQKD) is the art of using untrusted devices to distribute secret keys in an insecure network. It thus represents the ultimate form of cryptography, offering not only information-theoretic security against channel attacks, but also against attacks exploiting implementation loopholes. In recent years, much progress has been made towards realising the first DIQKD experiments, but current proposals are just out of reach of today’s loophole-free Bell experiments. Here, we significantly narrow the gap between the theory and practice of DIQKD with a simple variant of the original protocol based on the celebrated Clauser-Horne-Shimony-Holt (CHSH) Bell inequality. By using two randomly chosen key generating bases instead of one, we show that our protocol significantly improves over the original DIQKD protocol, enabling positive keys in the high noise regime for the first time. We also compute the finite-key security of the protocol for general attacks, showing that approximately 108–1010 measurement rounds are needed to achieve positive rates using state-of-the-art experimental parameters. Our proposed DIQKD protocol thus represents a highly promising path towards the first realisation of DIQKD in practice.

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Tentacle Morphological Variation Coincides with Differential Expression of Toxins in Sea Anemones

Toxins ◽

10.3390/toxins13070452 ◽

2021 ◽

Vol 13 (7) ◽

pp. 452

Author(s):

Lauren M. Ashwood ◽

Michela L. Mitchell ◽

Bruno Madio ◽

David A. Hurwood ◽

Glenn F. King ◽

...

Keyword(s):

Differential Expression ◽

Morphological Variation ◽

Expression Profiles ◽

The Body ◽

Sea Anemones ◽

Tissue Specific ◽

Venom Composition ◽

Specific Manner ◽

Branched Structures ◽

Morphological Variants

Phylum Cnidaria is an ancient venomous group defined by the presence of cnidae, specialised organelles that serve as venom delivery systems. The distribution of cnidae across the body plan is linked to regionalisation of venom production, with tissue-specific venom composition observed in multiple actiniarian species. In this study, we assess whether morphological variants of tentacles are associated with distinct toxin expression profiles and investigate the functional significance of specialised tentacular structures. Using five sea anemone species, we analysed differential expression of toxin-like transcripts and found that expression levels differ significantly across tentacular structures when substantial morphological variation is present. Therefore, the differential expression of toxin genes is associated with morphological variation of tentacular structures in a tissue-specific manner. Furthermore, the unique toxin profile of spherical tentacular structures in families Aliciidae and Thalassianthidae indicate that vesicles and nematospheres may function to protect branched structures that host a large number of photosynthetic symbionts. Thus, hosting zooxanthellae may account for the tentacle-specific toxin expression profiles observed in the current study. Overall, specialised tentacular structures serve unique ecological roles and, in order to fulfil their functions, they possess distinct venom cocktails.

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Signatures of the Carrier Envelope Phase in Nonlinear Thomson Scattering

Crystals ◽

10.3390/cryst11050528 ◽

2021 ◽

Vol 11 (5) ◽

pp. 528

Author(s):

Marcel Ruijter ◽

Vittoria Petrillo ◽

Thomas C. Teter ◽

Maksim Valialshchikov ◽

Sergey Rykovanov

Keyword(s):

Laser Pulse ◽

Radiation Spectrum ◽

Thomson Scattering ◽

High Energy ◽

Phase Changes ◽

High Energy Radiation ◽

Carrier Envelope Phase ◽

High Intensity Laser ◽

Experimental Parameters ◽

Intensity Laser

High-energy radiation can be generated by colliding a relativistic electron bunch with a high-intensity laser pulse—a process known as Thomson scattering. In the nonlinear regime the emitted radiation contains harmonics. For a laser pulse whose length is comparable to its wavelength, the carrier envelope phase changes the behavior of the motion of the electron and therefore the radiation spectrum. Here we show theoretically and numerically the dependency of the spectrum on the intensity of the laser and the carrier envelope phase. Additionally, we also discuss what experimental parameters are required to measure the effects for a beamed pulse.

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