Evolution and development of brain networks: from Caenorhabditis elegans to Homo sapiens

Neural networks show a progressive increase in complexity during the time course of evolution. From diffuse nerve nets in Cnidaria to modular, hierarchical systems in macaque and humans, there is a gradual shift from simple processes involving a limited amount of tasks and modalities to complex functional and behavioral processing integrating different kinds of information from highly specialized tissue. However, studies in a range of species suggest that fundamental similarities, in spatial and topological features as well as in developmental mechanisms for network formation, are retained across evolution. 'Small-world' topology and highly connected regions (hubs) are prevalent across the evolutionary scale, ensuring efficient processing and resilience to internal (e.g. lesions) and external (e.g. environment) changes. Furthermore, in most species, even the establishment of hubs, long-range connections linking distant components, and a modular organization, relies on similar mechanisms. In conclusion, evolutionary divergence leads to greater complexity while following essential developmental constraints.     

Heat and mass transfer characteristics of radiative hybrid nanofluid flow over a stretching sheet with chemical reaction

Unsteady magnetohydrodynamic heat and mass transfer analysis of hybrid nanoliquid flow over a stretching surface with chemical reaction, suction, slip effects, and thermal radiation is analyzed in this study. A combination of alumina (Al₂O₃) and titanium oxide (TiO₂) nanoparticles are taken as hybrid nanoparticles and water is considered as the basefluid. Using the similarity transformation method, the governing equations are changed into a system of ordinary differential equations. These equations together with boundary conditions are numerically evaluated by using the Finite element method. The influence of various pertinent parameters on the profiles of fluids concentration, temperature, and velocity is calculated and the outcomes are plotted through graphs. The values of nondimensional rates of heat transfer, mass transfer, and velocity are also analyzed and the results are depicted in tables. Temperature sketches of hybrid nanoliquid intensified in both the steady and unsteady cases as the volume fraction of both nanoparticles rises.     

The use of life cycle tools to support decision making for sustainable nanotechnologies

Nanotechnology is a broad-impact technology with applications ranging from materials and electronics to analytical methods and metrology. The many benefits that can be realized through the utilization of nanotechnology are intended to lead to an improved quality of life. However, numerous concerns have been expressed regarding the unchecked growth of nanotechnology and the unforeseen consequences it may bring. To address the concerns, nanotechnology must be examined under the microscope of sustainability. This work applies the life cycle perspective to provide an understanding of the challenges facing the development of sustainable nanotechnology. A discussion of the holistic tools used to assess the components of sustainability serves as the basis to examine how a harmony between policy and product development can be maintained using decision making for sustainability. This harmony will be most readily achieved using an enhanced risk management strategy for sustainability that combines sustainability assessment with sustainable chemical design.     

Structural Modifications and Extended Spectral Response of CeO2/CoPc Nanocomposites for Potential Applications

CeO₂/CoPc nanocomposites were synthesized by simple chemical method. Thermal behavior of these nanocomposites was studied by thermogravimetric and differential thermal analysis. The as‐synthesized nanocomposite samples were characterized by various techniques. A decrease in band‐gap energy together with an improved absorption intensity of the composite material confirms the role of the cobalt phthalocyanine in the absorption properties of CeO₂/CoPc composite. This study confirms structural modifications and extended spectral response of the synthesized CeO₂/CoPc nanocomposites. The results demonstrate that CeO₂/CoPc nanocomposite samples are promising materials for organic light‐emitting diodes, solar cells, and optoelectronic devices.     

PREDICTION OF JAPANESE ENCEPHALITIS VECTORS IN KURNOOL DISTRICT OF ANDHRA PRADESH,INDIA BY USING BAYESIAN NETWORK

Japanese encephalitis (JE), a complex viral disease transmitted by mosquitoes. Determination of vector (mosquito) density is a prerequisite for devising effective control measures against this disease. Bayesian network is a widely used tool that has recently found application in the epidemiological surveillance studies. This article describes the application of Bayesian network tool to predict the Japanese encephalitis vector density using the longitudinal data collected from the Kurnool district of Andhra Pradesh, India, from 2001 to 2006. The entomological parameter from the study area indicates that various contributing factors are responsible for the prevalence of these vectors, making it difficult to estimate the importance of any particular parameter contributing to the increase of vector density. The application of this approach resulted in 73.12% to 95.12% accuracy compared to the test data with the corrected data.     

Wide-band GaInAs MISFET amplifiers

The authors present the first reported results on wideband GaInAs MISFET amplifiers. Using 1-μm-gate-length, 0.56-mm-gate-width GaInAs MISFETs, they obtained: (a) a power output of 230±30 mW (0.41 W/mm) with 33±3% power-added efficiency; (b) a power output of 265±15 mW (0.47 W/mm) with 30±3% power-added efficiency (both over the 7-11-GHz band), and (c) a power output of 220±45 mW (0.39 W/mm) with 32±4% power-added efficiency over the 6-12-GHz band. With a 0.7-μm-gate-length GaInAs MISFET, a small-signal gain of 5±0.5 dB over the 11.4-22.6-GHz band was obtained. These data include all connector, bias network, and circuit losses. The authors present an equivalent circuit model of these MISFETs based on S-parameter measurements. The model is essentially that of a MISFET with capacitors representing gate-to-source and gate-to-drain overlap capacitances added at input and output     

High-fidelity lightwave transmission of multiple AM-VSB NTSCsignals

The progress towards developing AM lightwave links for the transmission of multiple TV signals is reported. While the signal-quality objectives and transmission distances are appropriate for CATV trunking, the technology is expected to have applicability to the distribution of video signals in the subscriber loop. Highly linear 1.3-μm distributed feedback (DFB) lasers designed expressly for analog requirements are used to transmit 42 continuous wave carriers according to the standard US CATV frequency plan. For the best lasers, when evaluated over 12 km of fiber, carrier to noise was >52 dB, composite second-order distortion was >70 dBc, and composite triple beat was >70 dBc. The relationship between measurements with continuous wave carriers and actual video signals is discussed. System design rules are offered. Properties that lead to superior analog performance are discussed. Data from 700 links indicate that composite third-order distortion generally scales with product count but that composite second-order distortion has a significant frequency-dependent component     

Silver–ethylene glycol and copper–ethylene glycol based thermally radiative nanofluid characteristics between two rotating stretchable disks with modified Fourier heat flux

In the present analysis, our aim is to investigate the mass and heat transport of silver (Ag)–ethylene glycol (EG) and copper (Cu)–EG-based nanofluids between two rotating stretchable disks under the convective boundary conditions. We have also incorporated Cattaneo–Christov heat flux, thermal radiation, and chemical reaction in the fluid flow. The system of coupled partial differential equations is transformed into ordinary differential equations by using similarity transformations. The finite element method has been accomplished to find numerical solutions to transformed equations. The behavior of radial and tangential velocity, temperature fields, and concentration fields influenced by the various parameters are sketched through graphs. The local skin friction coefficient, Nusselt number, and Sherwood number are also calculated for the pertinent parameters and displayed the results through tables. It is perceived that velocity sketches of both nanoliquids degenerate with larger values of thermal relaxation parameters. Also, the values local Nusselt number of both Ag–EG, and Cu–EG based Cattaneo–Christov nanofluid intensifies with improving values of stretching parameter at the lower disk, whereas, it impedes at the upper disk.     

Maxwell nanofluid heat and mass transfer analysis over a stretching sheet

The Buongiorno model Maxwell nanofluid flow, heat and mass transfer characteristics over a stretching sheet with a magnetic field, thermal radiation, and chemical reaction is numerically investigated in this analysis. This model incorporates the effects of Brownian motion and thermophoresis. The governing partial differential equations are transformed into a coupled nonlinear ordinary differential equation by using the similarity transformation technique. The resultant nonlinear differential equations are solved by using the Finite element method. The sketches of velocity, temperature and concentration with diverse values of magnetic field parameter (0.1 ≤ M ≤ 1.5), Deborah number (0.0 ≤ β ≤ 0.19), radiation parameter (0.1 ≤ R ≤ 0.7), Prandtl number (0.5 ≤ Pr ≤ 0.8), Brownian motion parameter (0.1 ≤ Nb ≤ 0.7), thermophoretic parameter (0.2 ≤ Nt ≤ 0.8), Chemical reaction parameter (1.0 ≤ Cr ≤ 2.5) and Lewis number (1.5 ≤ Le ≤ 3.0) have investigated and are depicted through plots. Moreover, the values of the Skin-friction coefficient, Nusselt number, and Sherwood numbers are also computed and are shown in tables. The sequels of this analysis reviewed that the values of Skin-friction coefficient and Sherwood number intensified with hiked values of Deborah number (β), whereas, the values of Nusselt number decelerate as values of (β) improves.     

Alkylation of benzene with isopropanol over SAPO‐5: A kinetic study

The kinetics of benzene alkylation with isopropanol has been studied in vapour phase over SAPO‐5 catalyst. On the basis of the product distribution pattern obtained over this large pore molecular sieve, a reaction mechanism has been proposed. Based on this reaction network, suitable phenomenological models have been derived and fitted to the kinetic data. A Langmuir‐Hinshelwood model with surface reaction involving single site mechanism fitted the data better than the other models. The deactivation kinetics has also been investigated in the low temperature chosen. The activation energy for the deactivation reaction in this range is found to be lower than that for the main reaction.