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Author(s):  
Uche A.K. Chude-Okonkwo

Aims: To model molecular signal propagation in confined environment. Background: Molecular communication (MC) is rooted in the concepts of understanding, modeling, and engineering information exchange among naturally and artificially synthesized nanosystems. To develop or analyze an MC system, there is the need to model the communication channel through which the molecular signal diffuse, from the transmitter to the receiver. Many models for the diffusion-based MC channel have been proposed in the literature for evaluating the performance of MC systems. Most of the contemporary works assume, and rightly so for some scenarios, that the MC channels under consideration have infinite boundaries. However, this assumption becomes invalid in bounded domains such as the interiors of natural cells and artificially synthesized nanosystems. Objective: In this paper, the model of molecular propagation in a confined. microenvironment is employ to explore the effect of such an environment on the MC system. Method: The mutual information of the channel and specifically the closed-form expression of the channel capacity of the molecular signaling in the confined geometry is derive. Result: Numerical results showing the variation in the channel capacity as the function of the channel dimension are presented. Conclusion: Results showed that the channel capacity increases with the decrease in the channel dimension. Subsequently, as the dimension of the channel tends to the nanoscale range typical of many artificially synthesized nanosystems, the effect of the channel width on the capacity and by induction on many other system metrics increases.


Author(s):  
Ghassan Adnan NAEEM ◽  
Ahmed Saadoun JALOOT ◽  
Mustafa Nadhim OWAID ◽  
Rasim Farraj MUSLIM

The present research aims to produce gold nanoparticles (AuNPs) from the aqueous extract of locally isolated mushroom Coprinus comatus from Hit city, Iraq. Its properties were studied using the optical vision, UV-Vis, EDX, XRD, FTIR, AFM, and Zetasizer analyses. The exposure of the colloidal solution of AuNPs to UV radiation was investigated for 1, 2, and 3 h. The results showed the color change of the interaction mixture from light yellow to purple after 25 min. The lambda max of the absorbance reached 530 nm using UV-Visible spectrum as evident in the formation of AuNPs. FTIR spectra revealed the presence of functional groups related to peptides, proteins, flavonoids, monosaccharides, and phenolic compounds, which reduced gold ions. The EDX technique showed that the formed nanoparticles were AuNPs. XRD results showed that AuNPs have a face-centered cubic (fcc) crystal. The UV irradiation at different times led to an increase in the intensity of absorbance and sizes of AuNPs from 17.39 nm before the irradiation and switched to 58.16, 59.13, and 47.35 nm after 1, 2, and 3 h, respectively, but their sizes remained within the nanoscale range (less than 100 nm). In conclusion, the best result was observed after about an hour on the effects of UV irradiation on sizes of AuNPs, which reached smaller nanoparticles compared with times 2 and 3 h.


2021 ◽  
Vol 12 (1) ◽  
pp. 38-45
Author(s):  
M. A. Kuznetsov ◽  
D. P. Ilyaschenko ◽  
A. V. Kryukov ◽  
S. A. Solodsky ◽  
E. V. Lavrova ◽  
...  

Modeling of velocities and temperatures processes distribution in the plasma-forming channel determining the design features and optimal parameters of the plasma torch nozzle is one of promising directions in development of plasma technologies. The aim of this work was to simulate the processes of velocities and temperature distribution in the plasma-forming channel and to determine the design features and optimal geometric parameters of the plasmatron nozzle  which  ensures  the  formation  of  necessary  direction  of  plasma  flows for generation of surface waves on the surface of a liquid metal droplet under the influence of the investigated instabilities.One of the main tasks is to consider the process of plasma jet formation and the flow of electric arc plasma. For obtaining small-sized particles one of the main parameters is the plasma flow  velocity.  It  is necessary that the plasma outflow velocity be close to supersonic. An increase of  the  supersonic  speed  is possible due to design of the plasmatron nozzle especially the design feature and dimensions of the gas channel in which the plasma is formed. Also the modeling took into account dimensions of the plasma torch nozzle, i. e. the device should provide a supersonic plasma flow with the smallest possible geometric dimensions.As a result models of velocities and temperatures distribution in the plasma-forming channel at the minimum and maximum diameters of the channel were obtained. The design features and optimal geometric parameters of the plasmatron have been determined: the inlet diameter is 3 mm, the outlet diameter is 2 mm.The design of the executive equipment has been developed and designed which implements the investigated process of generating droplets of the micro- and nanoscale range. A plasmatron nozzle was manufactured which forms the necessary directions of plasma flows for the formation of surface waves on the metal droplet surface under the influence of instabilities. An algorithm has been developed for controlling of executive equipment that implements the process of generating drops of micro- and nanoscale range.


2021 ◽  
Vol 23 (15) ◽  
pp. 9061-9064
Author(s):  
Ralph A. Wheeler ◽  
Emily E. Dalbey

Fitting X-ray structure factor lineshapes from experiment or simulation quantifies the nanoscale range of charge alternation in the title compound.


Author(s):  
Peter L. Rodríguez-Kessler ◽  
Macarena Rojas-Poblete ◽  
Alvaro Muñoz-Castro

Ultrasmall ligand-protected clusters prototypical species to evaluate the variation at the bottom of the nanoscale range. Here we explored the ultrasmall gold-phosphine M13(dppe)6 cluster, as a prototypical framework to gain...


2021 ◽  
Vol 21 (1) ◽  
pp. 578-583
Author(s):  
Chunhua Guo ◽  
Yu Yang ◽  
Hansen Sun ◽  
Wangang Chen ◽  
Ping Yan ◽  
...  

Because coal is quite weak compared with conventional sandstone, shear failure downhole will produce a large amount of nanoscale coal fines during the drainage process. Since the size of pores in coal is on the nanoscale range, these fines will sometimes cause serious damage problems downhole. The origin of coal fines cannot be explained by conventional sand prediction theory, which was previously designed for conventional sandstone. During the drainage process, the in situ stress change in coal was caused by the combination of the poroelastic effect, methane desorption and compression around the borehole. To prevent nanoscale coal fines, the critical pressure drawdown can be predicted by the comprehensive stress model. A special test was also designed to determine the key model parameters, making the model easy to use. It was proven that the induced stress due to methane desorption can exaggerate the shear failure, which is different from conventional sand prediction theory. Based on the stress model, the safe window of bottom hole pressure was applied for open-hole horizontal wells to prevent the origin of nanoscale coal fines.


Author(s):  
Asif Ahmad Malik ◽  
Nisar A. Dangroo ◽  
Rabia Amin ◽  
Zubaid Ul Khazir ◽  
Tabassum Ara

Nanotechnology offers multiple benefits. Nanomedicine and nanodelivery systems are relatively new areas in nanotechnology. There are number of outstanding applications of the nanomedicine in diagnosing diseases, delivering drugs to its target location, and thus treating human diseases. Here materials in the nanoscale range are employed to serve as means of diagnostic tools and also to deliver precise medicines to specific targeted sites in a controlled manner. Also, metal nanoparticles offer great interest in modern chemistry and materials research because of their applications in diverse fields such as photochemistry, nanoelectronics, optics, and catalysis. Chemistry provides various nanostructured materials either synthetic or isolated from natural sources offers opportunities and challenges in drug delivery and their applications including biomedical imaging, biosensing, diagnostic, and therapy. Thymoquinone, a bioactive compound in Nigella sativa, after encapsulation in lipid nanocarrier, has been found to show six-fold increase in bioavailability in comparison to free thymoquinone. In addition to this, organic nanomaterials have recently become of great interest for photovoltaic applications also.


2021 ◽  
Vol 09 (04) ◽  
pp. 57-64
Author(s):  
Muna Hajjyahya ◽  
Maen Ishtaiwi ◽  
Jeelan Sayyed ◽  
Ayyam Saddouq

2020 ◽  
Vol 1 ◽  
Author(s):  
H. Peneder ◽  
E. Punz ◽  
I.A. Joubert ◽  
M. Geppert ◽  
M. Himly

Due to their extremely small size, nanoparticles cannot be analyses by conventional approaches such as light microscopy. To visualise particles in the nanoscale range, a combination of an ultra-microscope and a laser illumination unit has to be applied. This combinatory technique is called Nanoparticle Tracking Anlysis (NTA) and can be used of thr nalysis of particles in a size range of approximately 10 nm up to 1 μm in liquid suspension. 


2019 ◽  
Vol 29 (10) ◽  
pp. 2050158
Author(s):  
M. Elangovan ◽  
K. Gunavathi

The ultimate aim of a memory designer is to design a memory cell which could consume low power with high data stability in the deep nanoscale range. The implementation of Very Large-Scale Integration (VLSI) circuits using MOSFETs in nanoscale range faces many issues such as increasing of leakage power and second-order effects that are easily affected by the PVT variation. Hence, it is essential to find the best alternative of MOSFET for deep submicron design. The Carbon Nanotube Field Effect Transistor (CNTFET) can eradicate all the demerits of MOSFET and be the best replacement of MOSFET for nanoscale range design. In this paper, a 10T CNTFET Static Random Access Memory (SRAM) cell is proposed. The power consumption and Static Noise Margin (SNM) are analyzed. The power consumption and stable performance of the proposed 10T CNTFET SRAM cell are compared with that of conventional 10T CNTFET SRAM cell. The power and stability analyses of the proposed 10T and conventional 10T CNTFET SRAM cells are carried out for the CNTFET parameters such as pitch and chiral vector ([Formula: see text]). The power and SNM analyses are carried out for [Formula: see text]20% variation of oxide thickness (Hox), different dielectric constant (Kox). The supply voltage varies from 0.9[Formula: see text]V to 0.6[Formula: see text]V and temperature varies from 27∘C to 125∘C. The simulation results show that the proposed 10T CNTFET SRAM cell consumes lesser power than conventional 10T CNTFET SRAM cell during the write, hold and read modes. The write, hold and read stability of the proposed 10T CNTFET SRAM cell are higher as compared with that of conventional 10T CNTFET SRAM. The conventional and proposed 10T SRAM cells are also implemented using MOSFET. The stability and power performance of proposed 10T SRAM cell is also as good as conventional 10T SRAM for MOSFET implementation. The proposed 10T SRAM cell consumes lesser power and gives higher stability than conventional 10T SRAM cell in both CNTFET and MOSFET implementation. The simulation is carried out using Stanford University 32[Formula: see text]nm CNTFET model in HSPICE simulation tool.


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