Control of nanoparticle synthesis using physical and chemical dynamics of gas–liquid interfacial non-equilibrium plasmas

2012 ◽  
Vol 54 (12) ◽  
pp. 124027 ◽  
Author(s):  
T Kaneko ◽  
S Takahashi ◽  
R Hatakeyama
Keyword(s):  
Nanoparticle Synthesis ◽  
Chemical Dynamics ◽  
Physical And Chemical ◽  
Non Equilibrium

Non-equilibrium Thermodynamics of Fast Traveling Waves in a Catalytic Fixed Bed. Emergence of Near-equilibrium Spatiotemporal Dissipative Structure

2018 ◽  
Vol 43 (3) ◽  
pp. 221-235
Author(s):  
Alexander P. Gerasev
Keyword(s):  
Mathematical Model ◽  
Wave Propagation ◽  
Traveling Wave ◽  
Dissipative Structure ◽  
Fixed Bed ◽  
Dissipative Structures ◽  
Catalytic Reactors ◽  
Linear Ordinary Differential Equations ◽  
Physical And Chemical ◽  
Non Equilibrium

AbstractThis work presents the results of the mathematical modeling of the fast traveling wave propagation phenomenon in the fixed-bed catalytic reactors according to a simple (basic) mathematical model with a reversible reaction. Qualitative and quantitative research is used to study the behavior of separatrices’ trajectories of the system’s non-linear ordinary differential equations. Special attention has been paid to the non-equilibrium thermodynamic methods. The entropy balance equation is constructed and analyzed under the assumption of the simple mathematical model of physical and chemical processes. The influence of key physical and chemical parameters on the fast traveling wave properties is studied. The phenomenon of fast traveling wave propagation in the fixed-bed catalytic reactors provides a vivid example of a spatiotemporal dissipative structure in active heterogeneous medium. These dissipative structures are shown to exist near the thermodynamic equilibrium.

scholarly journals Consequences of Nonequilibrium Pesticide Fate Processes on Probability of Leaching from Agricultural Lands

1994 ◽  
Author(s):  
R.J. Waganet ◽  
John Duxbury ◽  
Uri Mingelgrin ◽  
John Hutson ◽  
Zev Gerstl
Keyword(s):  
Simulation Models ◽  
Chemical Processes ◽  
Relative Ease ◽  
Equilibrium Processes ◽  
Field Soils ◽  
Physical And Chemical ◽  
Insight Into ◽  
Structural Cracks ◽  
Non Equilibrium ◽  
Pesticide Leaching

Pesticide leaching in heterogeneous field soils is relatively unstudied and is the focus of this project. A wide variety of heterogeneous soils exist, characterized by processes that result from the presence of structural cracks, worm holes, and other preferred pathways within which the majority of transport can occur (called physical non-equilibrium processes), along with the presence of sorption processes that are both equilibrium and kinetic (chemical non-equilibrium processes). Previous studies of pesticide leaching have focused primarily on relatively homogeneous soils, which are less widely distributed in nature, but more studied due to the relative ease with which quantitative theory can be applied to interpret experimental results. The objectives of the proposed project were: first, to gain greater insight into the basic physical and chemical processes that characterize non-equilibrium systems, second, to improve our ability to predict pesticide leaching in heterogeneous field soils, and third, to estimate the consequences of non-equilibrium processes at the field scale by conducting an analysis of the probability of pesticide leaching when non-equilibrium processes prevail. The laboratory, theoretical and modelling aspects of the project were successful; the field aspects less so. We gained greater insight into basic processes in heterogeneous field soils, and we improved and tested tools (simulation models) and the methodology of using such tools for assessing the probability of pesticide leaching as a contribution to broader risk analysis efforts.

scholarly journals Green Synthesis of Copper Nanoparticles, Characterization and Their Applications

2020 ◽  
pp. 10-24
Author(s):  
Swathi Pavithran ◽  
Manikantan Pappuswamy ◽  
Yamuna Annadurai ◽  
Vijaya Anand Armugam ◽  
Thirunavukkarasu Periyaswamy
Keyword(s):  
Green Synthesis ◽  
Copper Nanoparticles ◽  
Dye Degradation ◽  
Biological Effects ◽  
Nanoparticle Synthesis ◽  
Nanoparticles Characterization ◽  
Bacteria And Fungi ◽  
Analytical Tools ◽  
Physical And Chemical

Nanotechnology is one of the upcoming topics in the present era. Nanoparticles are synthesized by physical and chemical methods but limitations are due to their toxicity. Hence, green synthesis is more on demand which involves the use of plants, bacteria and fungi. In this review, copper nanoparticle synthesis is focused which is economically beneficial and eco-friendly when compared to other metal nanoparticles. Copper nanoparticles are used in diverse fields such as biomedicine, pharmaceuticals, bioremediation, molecular biology, bioengineering, genetic engineering, dye degradation, catalysis, cosmetics and textiles. Structural properties and biological effects of copper nanoparticles have promising affectivity in the field of life sciences. The characterization of biogenic copper nanoparticles by number of analytical tools for their compositional, morphological and topographical features has also been discussed.

scholarly journals Decision-Making in Physical Intelligent Systems Regulated by Growth Rate Factors

2014 ◽  
Vol 7 (4) ◽  
pp. 55
Author(s):  
Till D. Frank
Keyword(s):  
Decision Making ◽  
Growth Rate ◽  
Intelligent Systems ◽  
Equilibrium System ◽  
Discharge System ◽  
Chemical Systems ◽  
Self Organized ◽  
Current Flows ◽  
Physical And Chemical ◽  
Non Equilibrium

In the literature, self-organizing physical and chemical systems have been proposed as candidates for physical intelligent systems that may solve problems in the field of artificial intelligent in a non-algorithmic way that is not based on computation. In this theoretical study, decision-making in such physical intelligent systems is discussed in terms of non-equilibrium transitions between two self-organized states. The control parameter driving the non-equilibrium transitions is related to two growth rate factors. It is shown for a particular non-equilibrium system that the decision-making process satisfies the principle of selecting the state with the fastest growth rate factor. The system under consideration is a two component gas discharge system whose current flows can be described by means of an electronic blueprint.

Investigation of The Use of Titanium Dioxide Nanoparticles in Solar Cells

2020 ◽  
Vol 4 (1) ◽  
pp. 11-20
Author(s):  
Chen Luo ◽  
Jingting Li ◽  
Jie Xu
Keyword(s):  
Titanium Dioxide ◽  
Solar Cells ◽  
Electronic Device ◽  
Titanium Dioxide Nanoparticles ◽  
Synthesis Method ◽  
Nanoparticle Synthesis ◽  
Chemical Properties ◽  
Volume Ratio ◽  
Photochemical Reactions ◽  
Physical And Chemical

Today, nanoparticles have attracted the attention of many researchers due to their special properties as well as their many technological applications. Among these, titanium dioxide nanoparticles have many important applications in various industries due to their excellent optical, electrical and catalytic properties. These applications include use in industrial pigments, as photocatalysts in environmental cleansing, in sunscreens to protect the skin, in photovoltaic applications for solar cells, sensors, in electronic device components, and many more. Two important properties of this material that make it very efficient and useful in life are its photocatalytic and superhydrophobic properties. These two properties are used to purify water and wastewater, eliminate air pollution and buildings, accelerate photochemical reactions such as hydrogen production, fabricate surfaces and layers and self-cleaning glass. The properties of titanium dioxide nanoparticles are strongly dependent on the size of the doped particles, elements or compounds and the surface modifications made on them, which in turn are influenced by the nanoparticle synthesis method. For this reason, methods for the synthesis of titanium dioxide nanoparticles have received much attention today. As the size of the material gets smaller and smaller and reaches the nanoscale, new physical and chemical properties show up. Among the unique properties of nanomaterials, the motion of electrons and holes in semiconductor nanomaterials is dominated by quantum constraint, and the transfer properties of phonons and photons are strongly influenced by the size and geometry of the material. The effective surface area and surface to volume ratio increase with decreasing the material size. High effective levels are achieved by small particles, which will be useful in many 2TiO-based types of equipment in which the interaction of the common surface of the material is important.

scholarly journals Towards the First Principles in Biology and Cancer: New Vistas in Computational Systems Biology of Cancer

Life ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 21
Author(s):  
Aleš Prokop
Keyword(s):  
Systems Biology ◽  
First Principles ◽  
Genomic Analysis ◽  
Lessons Learned ◽  
Emergent Properties ◽  
Computational Systems Biology ◽  
New Paradigm ◽  
Equilibrium Thermodynamics ◽  
Physical And Chemical ◽  
Non Equilibrium

These days many leading scientists argue for a new paradigm for cancer research and propose a complex systems-view of cancer supported by empirical evidence. As an example, Thea Newman (2021) has applied “the lessons learned from physical systems to a critique of reductionism in medical research, with an emphasis on cancer”. It is the understanding of this author that the mesoscale constructs that combine the bottom-up as well as top-down approaches, are very close to the concept of emergence. The mesoscale constructs can be said to be those effective components through which the system allows itself to be understood. A short list of basic concepts related to life/biology fundamentals are first introduced to demonstrate a lack of emphasis on these matters in literature. It is imperative that physical and chemical approaches are introduced and incorporated in biology to make it more conceptually sound, quantitative, and based on the first principles. Non-equilibrium thermodynamics is the only tool currently available for making progress in this direction. A brief outline of systems biology, the discovery of emergent properties, and metabolic modeling are introduced in the second part. Then, different cancer initiation concepts are reviewed, followed by application of non-equilibrium thermodynamics in the metabolic and genomic analysis of initiation and development of cancer, stressing the endogenous network hypothesis (ENH). Finally, extension of the ENH is suggested to include a cancer niche (exogenous network hypothesis). It is expected that this will lead to a unifying systems–biology approach for a future combination of the analytical and synthetic arms of two major hypotheses of cancer models (SMT and TOFT).

scholarly journals Green Synthesis of Metallic Nanoparticles Using Some Selected Medicinal Plants from Southern Africa and Their Biological Applications

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1929
Author(s):  
Jumoke A. Aboyewa ◽  
Nicole R. S. Sibuyi ◽  
Mervin Meyer ◽  
Oluwafemi O. Oguntibeju
Keyword(s):  
Medicinal Plants ◽  
South African ◽  
Metallic Nanoparticles ◽  
Nanoparticle Synthesis ◽  
Biological Properties ◽  
Chemical Methods ◽  
One Pot ◽  
Anticancer Drug Delivery ◽  
African Plants ◽  
Physical And Chemical

The application of metallic nanoparticles (MNPs), especially that of silver, gold, cobalt, and zinc as antimicrobial, anticancer, drug delivery, contrast, and bioimaging agents has transformed the field of medicine. Their functions, which are attributed to their physicochemical properties, have gained prominence in various technological fields. Although MNPs can be produced via rigorous physical and chemical techniques, in recent years, a biological approach utilizing natural materials has been developed. With the increasing enthusiasm for safe and efficient nanomaterials, the biological method incorporating microorganisms and plants is preferred over physical and chemical methods of nanoparticle synthesis. Of these bio-entities, plants have received great attention owing to their capability to reduce and stabilize MNPs in a single one-pot protocol. South Africa is home to ~10% of the world’s plant species, making it a major contributor to the world’s ecological scenery. Despite the documented contribution of South African plants, particularly in herbal medicine, very few of these plants have been explored for the synthesis of the noble MNPs. This paper provides a review of some important South African medicinal plants that have been utilized for the synthesis of MNPs. The enhanced biological properties of the biogenic MNPs attest to their relevance in medicine. In this endeavour, more of the African plant biodiversity must be explored for the synthesis of MNPs and be validated for their potential to be translated into future nanomedicine.

scholarly journals Study of the Performance of the Organic Extracts ofChenopodium ambrosioidesfor Ag Nanoparticle Synthesis

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Luis M. Carrillo-López ◽  
Ramón M. Soto-Hernández ◽  
Hilda A. Zavaleta-Mancera ◽  
Alfredo R. Vilchis-Néstor
Keyword(s):  
Phenolic Compounds ◽  
Methanol Extract ◽  
Nanoparticle Synthesis ◽  
Chenopodium Ambrosioides ◽  
Flavone Glycoside ◽  
Nanoparticle Growth ◽  
Organic Extracts ◽  
Hexane Extracts ◽  
Reducing Activity ◽  
Physical And Chemical

There are many ways to obtain metal nanoparticles: biological, physical, and chemical ways and combinations of these approaches. Synthesis assisted with plant extracts has been widely documented. However, one issue that is under discussion refers to the metabolites responsible for reduction and stabilization that confine nanoparticle growth and prevent coalescence between nanoparticles in order to avoid agglomeration/precipitation. In this study, Ag nanoparticles were synthesized using organic extracts ofChenopodium ambrosioideswith different polarities (hexane, dichloromethane, and methanol). Each extract was phytochemically characterized to identify the nature of the metabolites responsible for nanoparticle formation. With methanol extract, the compounds responsible for reducing and stabilizing silver nanoparticle were associated with the presence of phenolic compounds (flavonoids and tannins), while, with dichloromethane and hexane extracts, the responsible compounds were mainly terpenoids. Large part of the reducing activity of secondary metabolites inC. ambrosioidesis closely related to compounds with antioxidant capacity, such as phenolic compounds (flavone glycoside and isorhamnetin), which are the main constituents of the methanol extracts. Otherwise, terpenoids (trans-diol,α-terpineol, monoterpene hydroperoxides, and apiole) are the central metabolites present in dichloromethane and hexane extracts.

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