scholarly journals Green manufacturing of metallic nanoparticles: a facile and universal approach to scaling up

2016 ◽  
Vol 4 (29) ◽  
pp. 11222-11227 ◽  
Author(s):  
Jicheng Feng ◽  
Xiaoai Guo ◽  
Nabil Ramlawi ◽  
Tobias V. Pfeiffer ◽  
Ruben Geutjens ◽  
...  
Keyword(s):  
Chemical Composition ◽  
High Frequency ◽  
Metallic Nanoparticles ◽  
Green Manufacturing ◽  
Building Blocks ◽  
Scaling Up ◽  
Universal Approach

A newly developed high frequency spark provides a green, sustainable and versatile platform for manufacturing diverse sub-10 nm particles with well-defined chemical composition that serve as key building blocks.

scholarly journals Excimer Laser Induced Spatially Resolved Formation and Implantation of Plasmonic Particles in Glass

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1035
Author(s):  
Maximilian Heinz ◽  
Jörg Meinertz ◽  
Manfred Dubiel ◽  
Jürgen Ihlemann
Keyword(s):  
Excimer Laser ◽  
Metallic Nanoparticles ◽  
Glass Matrix ◽  
Laser Pulses ◽  
Building Blocks ◽  
Phase Mask ◽  
Spatially Resolved ◽  
Stable Glass ◽  
193 Nm ◽  
Doped Glass

Metallic nanoparticles are important building blocks for plasmonic applications. The spatially defined arrangement of these nanoparticles in a stable glass matrix is obtained here by nanosecond excimer laser irradiation at 193 nm. Two approaches are addressed: (1) Laser induced formation of particles from a dopant material pre-incorporated in the glass, (2) Particle formation and implantation by irradiation of material pre-coated on top of the glass. Silver nanoparticles are formed inside Ag+ doped glass (method 1). Gold nanoparticles are implanted by irradiation of gold coated glass (method 2). In the latter case, with a few laser pulses the original gold film disintegrates into particles which are then embedded in the softened glass matrix. A micron sized spatial resolution (periodic arrangements with 2 µm period) is obtained in both cases by irradiating the samples with an interference beam pattern generated by a phase mask. The plasmonic absorption of the nanoparticles leads to a contrast of the optical density between irradiated and non-irradiated lines of up to 0.6.

HIV drug resistance in newly diagnosed adults in a rural prefecture of eastern China

2014 ◽  
Vol 143 (3) ◽  
pp. 663-672 ◽  
Author(s):  
J. HUA ◽  
H. LIN ◽  
Y. DING ◽  
D. QIU ◽  
F. WONG ◽  
...  
Keyword(s):  
Drug Resistance ◽  
High Frequency ◽  
Eastern China ◽  
Scaling Up ◽  
Genetic Mutations ◽  
Newly Diagnosed ◽  
Hiv Drug Resistance ◽  
Subtype B ◽  
Hiv Epidemic ◽  
Hiv 1

SUMMARYLittle is known about HIV drug resistance (HIVDR) in newly diagnosed HIV-infected adults in eastern China where the HIV epidemic is spreading predominantly through sexual contact. During 2008–2011, newly HIV-diagnosed adults in Taizhou prefecture, Zhejiang province in eastern China were examined for HIVDR by amplifying and sequencing the HIV-1 pol gene. Of 447 genotyped participants, 53·7% were infected with CRF01_AE, 20·1% with CRF07_BC, 12·5% with subtype B, and 11·6% with CRF08_BC. Most of the participants had one or more minor genetic mutations in the pol gene that are associated with HIVDR. Twelve (2·7%) participants met the standard guidelines of having low to high HIVDR, suggesting that the prevalence of HIVDR in newly HIV-diagnosed adults was low in the study area and current antiretroviral therapy (ART) regimens are likely to remain effective. However, given high frequency of minor HIVDR in HIV patients and the scaling up of ART programmes in China, larger HIVDR surveillance programmes are needed.

Ice lines and the formation of Uranus and Neptune

2020 ◽  
Author(s):  
Olivier Mousis ◽  
Artyom Aguichine ◽  
Ravit Helled ◽  
Patrick Irwin ◽  
Jonathan I. Lunine
Keyword(s):  
Chemical Composition ◽  
Transport Model ◽  
Outer Region ◽  
Building Blocks ◽  
Planetary Formation ◽  
Physical Conditions ◽  
Elemental Abundances ◽  
Self Consistent ◽  
Protosolar Nebula ◽  
Do So

<p>We aim at investigating whether the chemical composition of the outer region of the protosolar nebula can be consistent with current estimates of the elemental abundances in the ice giants. To do so, we use a self-consistent evolutionary disc and transport model to investigate the time and radial distributions of H<sub>2</sub>O, CO, N<sub>2</sub>, and H<sub>2</sub>S, i.e., the main O-, C-, N, and S-bearing volatiles in the outer disc. We show that it is impossible to accrete a mixture composed of gas and solids from the disc with a C/H ratio presenting enrichments comparable to the measurements (70 times protosolar). We also find that the C/N and C/S ratios measured in Uranus and Neptune are compatible with those acquired by building blocks agglomerated from grains and pebbles condensed in the vicinities of N<sub>2</sub> and CO ice lines in the nebula. In contrast, the presence of protosolar C/N and C/S ratios in Uranus and Neptune would imply that their building blocks agglomerated from particles condensed at higher heliocentric distances. Our study demonstrates the importance of measuring the elemental abundances in the ice giant atmospheres, as they can be used to trace the planetary formation location and/or the chemical and physical conditions of the protosolar nebula.<span class="Apple-converted-space"> </span></p>

Spectroscopic study of chemical composition of high-frequency glow-discharge in halogen-containing gas mixtures

1985 ◽  
Vol 43 (3) ◽  
pp. 971-975
Author(s):  
O. P. Gushchin ◽  
V. M. Dolgopolov ◽  
L. E. Pereverzev ◽  
D. I. Slovetskii
Keyword(s):  
Chemical Composition ◽  
Glow Discharge ◽  
Spectroscopic Study ◽  
High Frequency ◽  
Gas Mixtures

scholarly journals Applying Cryo-X-ray Photoelectron Spectroscopy to Study the Surface Chemical Composition of Fungi and Viruses

2021 ◽  
Vol 9 ◽  
Author(s):  
Andrey Shchukarev ◽  
Emelie Backman ◽  
Samuel Watts ◽  
Stefan Salentinig ◽  
Constantin F. Urban ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Biological Systems ◽  
Building Blocks ◽  
Model Organisms ◽  
Surface Chemical ◽  
Surface Layers ◽  
Xps Spectra ◽  
X Ray ◽  
Surface Chemical Composition

Interaction between microorganisms and their surroundings are generally mediated via the cell wall or cell envelope. An understanding of the overall chemical composition of these surface layers may give clues on how these interactions occur and suggest mechanisms to manipulate them. This knowledge is key, for instance, in research aiming to reduce colonization of medical devices and device-related infections from different types of microorganisms. In this context, X-ray photoelectron spectroscopy (XPS) is a powerful technique as its analysis depth below 10 nm enables studies of the outermost surface structures of microorganism. Of specific interest for the study of biological systems is cryogenic XPS (cryo-XPS). This technique allows studies of intact fast-frozen hydrated samples without the need for pre-treatment procedures that may cause the cell structure to collapse or change due to the loss of water. Previously, cryo-XPS has been applied to study bacterial and algal surfaces with respect to their composition of lipids, polysaccharides and peptide (protein and/or peptidoglycan). This contribution focuses onto two other groups of microorganisms with widely different architecture and modes of life, namely fungi and viruses. It evaluates to what extent existing models for data treatment of XPS spectra can be applied to understand the chemical composition of their very different surface layers. XPS data from model organisms as well as reference substances representing specific building blocks of their surface were collected and are presented. These results aims to guide future analysis of the surface chemical composition of biological systems.

scholarly journals Inverse Molecular Design Techniques for Green Chemical Design in Integrated Biorefineries

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1569
Author(s):  
Jamie W. Y. Lee ◽  
Lik Yin Ng ◽  
Viknesh Andiappan ◽  
Nishanth G. Chemmangattuvalappil ◽  
Denny K. S. Ng
Keyword(s):  
Environmental Impact ◽  
Industrial Development ◽  
Molecular Design ◽  
Green Manufacturing ◽  
Building Blocks ◽  
Green Product ◽  
Technological Advancement ◽  
Process Route ◽  
Product And Process ◽  
Minimal Environmental Impact

Over the past decades, awareness of the increase in environmental impact due to industrial development and technological advancement has gradually increased. Green manufacturing is one of the key approaches that begin to address environmental issues. With the current global attention, methodologies to incorporate green manufacturing into the design of green products through the green process route are much needed. However, it is challenging for industries to achieve this, as there is no definite definition of green. This work presents a systematic approach that provides a clear and consistent green manufacturing definition with a measurement method in terms of both product and process. With the consistent green definitions, the developed approach designs a product that satisfies green property and other product performance properties. In addition, the developed approach synthesises the production process that fulfils green manufacturing definitions and financial considerations for the designed product. A case study on the design and production of green biofuel is solved to illustrate the efficacy of the approach. Green product design is obtained by identifying molecular building blocks that fulfil the targeted properties using an inverse molecular design technique. The goal is to design a chemical product that is environmentally friendly while fulfilling customer requirements. Moreover, a superstructural mathematical optimisation approach is used to determine optimal conversion pathways that have minimal environmental impact on the production of the identified green product. The utilisation of multi-objective optimisation allows the design of product and process to strike a good balance between operational and environmental performances.

scholarly journals Investigation of penetrator defect formation during high frequency induction welding in pipeline steels

2021 ◽  
Vol 349 ◽  
pp. 04002
Author(s):  
Christos Sofras ◽  
Marianthi Bouzouni ◽  
Nikolaos Voudouris ◽  
Spyros Papaefthymiou
Keyword(s):  
Chemical Composition ◽  
High Frequency ◽  
Defect Formation ◽  
Welding Process ◽  
High Strength ◽  
Chemical Compositions ◽  
Oxide Formation ◽  
Pipeline Steels ◽  
The Impact ◽  
High Frequency Induction

The aim of this study is to investigate the formation of oxide defects known as penetrators during high frequency induction welding process of high strength low alloy pipeline steels and to correlate their formation with the steel chemical composition. Penetrators formed during the welding process can be detrimental for the impact properties of the weld seam. For this purpose, three different samples, with different chemical compositions, were intentionally produced with penetrator-type oxides and investigated. In order to characterize the oxide defect and correlate their formation with the chemical composition of the steel, optical microscopy and scanning electron microscopy paired with energy dispersive spectroscopy were employed. In addition, thermodynamic calculations were performed in order to examine whether the chemical composition of pipeline steels is prone to oxide formation. The results showed that oxides with pancake type morphology were found alongside the fusion zone of the samples. They mainly consisted of manganese and silicon. First findings on the the Mn/Si ratio showed that the lower ratio is less susceptible to oxide formation.

Inclusion Compounds of Tetracyano Complexes and Their Electrical Properties

1994 ◽  
Vol 59 (11) ◽  
pp. 2436-2446 ◽  
Author(s):  
Mária Reháková ◽  
Anna Sopková ◽  
Vladimír Šály
Keyword(s):  
Electrical Conductivity ◽  
Chemical Composition ◽  
Electrical Properties ◽  
General Formula ◽  
Inclusion Compounds ◽  
High Frequency ◽  
Iodide Ions ◽  
Structure And Morphology ◽  
Composition Structure ◽  
Tetracyano Complexes

The presence of iodine and iodide ions in tetracyanonickelates inclusion compounds with the general formula Ni(B)mNi(CN)4 . n H2O (B = NH3 or ethylenediamine) changes the properties of these compounds. High frequency conductance measurements in the range of 10 - 105 Hz show that the products with ethylenediamine ligands have a higher electrical conductivity than those with NH3 ligands. The differences in the electrical properties between the compounds studied are mainly caused by chemical composition, structure and morphology.

scholarly journals Phyto-Nanocatalysts: Green Synthesis, Characterization, and Applications

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3418 ◽  
Author(s):  
Fierascu ◽  
Ortan ◽  
Avramescu ◽  
Fierascu
Keyword(s):  
Chemical Composition ◽  
Plant Extracts ◽  
Metallic Nanoparticles ◽  
Chemical Processes ◽  
Metallic Oxides ◽  
New Methods ◽  
Methods Of Synthesis ◽  
Promising Area ◽  
Shape Of Nanoparticles ◽  
Almost All

Catalysis represents the cornerstone of chemistry, since catalytic processes are ubiquitous in almost all chemical processes developed for obtaining consumer goods. Nanocatalysis represents nowadays an innovative approach to obtain better properties for the catalysts: stable activity, good selectivity, easy to recover, and the possibility to be reused. Over the last few years, for the obtaining of new catalysts, classical methods—based on potential hazardous reagents—have been replaced with new methods emerged by replacing those reagents with plant extracts obtained in different conditions. Due to being diversified in morphology and chemical composition, these materials have different properties and applications, representing a promising area of research. In this context, the present review focuses on the metallic nanocatalysts’ importance, different methods of synthesis with emphasis to the natural compounds used as support, characterization techniques, parameters involved in tailoring the composition, size and shape of nanoparticles and applications in catalysis. This review presents some examples of green nanocatalysts, grouped considering their nature (mono- and bi-metallic nanoparticles, metallic oxides, sulfides, chlorides, and other complex catalysts).

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