Interconnect Challenges and Carbon Nanotube as Interconnect in Nano VLSI Circuits

This chapter discusses about the behavior of Carbon Nanotube (CNT) different structures which can be used as interconnect in Very Large Scale (VLSI) circuits in nanoscale regime. Also interconnect challenges in VLSI circuits which lead to use CNT as interconnect instead of Cu, is reviewed. CNTs are classified into three main types including Single-walled Carbon Nanotube (SWCNT), CNT Bundle, and Multi-walled Carbon Nanotube (MWCNT). Because of extremely high quantum resistance of a SWCNT which is about 6.45 kΩ, rope or bundle of CNTs are used which consist of parallel CNTs in order to overcome the high delay time due to the high intrinsic (quantum) resistance. Also MWCNTs which consist of parallel shells, present much less delay time with respect to SWCNTs, for the application as interconnects. In this chapter, first a short discussion about interconnect challenges in VLSI circuits is presented. Then the repeater insertion technique for the delay reduction in the global interconnects will be studied. After that, the parameters and circuit model of a CNT will be discussed. Then a brief review about the different structures of CNT interconnects including CNT bundle and MWCNT will be presented. At the continuation, the time domain behavior of a CNT bundle interconnect in a driver-CNT bundle-load configuration will be discussed and analyzed. In this analysis, CNT bundle is modeled as a transmission line circuit model. At the end, a brief study of stability analysis in CNT interconnects will be presented

A Review of Electronic Band Structure of Graphene and Carbon Nanotubes Using Tight Binding

The electronic band structure variations of single-walled carbon nanotubes (SWCNTs) using Huckle/tight binding approximation theory are studied. According to the chirality indices, the related expressions for energy dispersion variations of these elements are derived and plotted for zigzag and chiral nanotubes

COX inhibition: Catalepsy and Striatum Dopaminergic-GABAergic-Glutamatergic Neurotransmission

Selective COX-2 and COX-1 inhibitors were administered (i.p. acutely) to normal and parkinsonian rats, followed by the analysis of the striatal dopamine, GABA and glutamate concentrations using the microdialysis technique, simultaneously, the catalepsy of animals was evaluated. Selective COX-2 inhibition showed improving effects on the catalepsy followed by decreasing the striatum glutamatergic-GABAergic and enhancing the dopaminergic neurotransmission. Nonetheless COX inhibition had no significant improving effects on damaged Substantia Nigra Pars Compacta (SNc) neurons

Comparación de los rendimientos del maíz, empleo de agua y crecimiento bajo diferentes sistemas de laboreo y tipos de fertilizantes

Contexto: EL maíz es uno de los cuatro cereales más importantes después del trigo y el arroz. El nitrógeno y variadas formas de laboreo son factores importantes para mejorar los rasgos y el rendimiento del maíz. La agricultura sostenible requiere de mejoras en cuanto al manejo del laboreo de los suelos, así como una aplicación más eficiente de los fertilizantes como recursos agrícolas. Objetivo: Esta investigación se enfocó en la importancia de realizar exámenes a las condiciones de los nutrientes, particularmente el consumo de nitrógeno en varios sistemas de laboreo, así como el impacto de estos factores en el rendimiento, crecimiento y eficiencia en el empleo del agua en el maíz cultivado en Irán. Métodos: El experimento se desarrolló en una parcela dividida, mediante un diseño experimental completamente aleatorio por bloques y cuatro réplicas, en la ciudad de Darreh shahr, provincia de Ilam, Irán. Los tratamientos consistieron en tres niveles de laboreo del suelo, incluyendo la siembra directa, mediante el laboreo combinado y surcos (arado Moldboard + gradas dobles + nivelador y surcos en la parcela principal). Resultados: Se demostró que la mayor cantidad de materia seca total se obtuvo en el tratamiento con mínimo laboreo (4542,7 g/m2), mientras que el menor valor se obtuvo mediante el cultivo tradicional (4029,2 g/m2). El volumen de fertilizante no utilizado (NPK)0 fue de 0,61 kg-m3. Se puede afirmar que el laboreo mínimo puede mejorar los rendimientos del maíz con el más alto EEA, y también puede incrementar sus propiedades durante la temporada de crecimiento. Conclusiones: Según los resultados de este estudio, se puede afirmar que el laboreo mínimo mejora los rendimientos del maíz con el más alto EEA, y también puede incrementar sus propiedades durante la temporada de crecimiento

Comparison of Corn Yield, Water Use Efficiency (WUE), and Growth under Different Tillage Systems and Fertilizer Inputs

Context: Corn is one of the four most important cereals in the world after wheat and rice. Nitrogen and various tillage systems are important factors in improving the traits and performance of corn. Sustainable agriculture requires improvements in soil tillage management and more efficient application of fertilizers as agricultural resources. Objective: Considering the importance of examining the status of nutrients, particularly nitrogen consumption in various tillage systems, and the impact of these factors on the performance, growth, and water use efficiency of corn in Iran, this research was conducted. Methods: The experiment was performed as a split plot in a randomized completely block design (RCBD) with four replications in Darreh shahr city, Ilam province, Iran. The treatments consisted of three levels of soil tillage including NT (direct sowing), MT (using compound tillage and furrow) and CT (Moldboard plow+ double discs + leveler and furrow) as the main plot. Results: The results showed that the highest total dry matter (TDM) was obtained in MT treatment at 4542.7 g/m2 and the lowest in CT treatment at 4029.2 g/m2. The amount of non-use of fertilizer (NPK)0 was 0.61 kg/m3. It can be stated that MT can improve the grain yield of corn with the highest WUE as well as increasing the properties during the growing season. Conclusions: Based on the results of this study, it can be stated that MT can improve maize grain yield with the highest WUE and increase the characteristics during the growing season

Design of single-mode single-polarization large-mode-area multicore fibers

ABSTRACT: In laser science and industry, considerable effort is directed toward designing fibers for fiber laser and fiber amplifier applications, each of which offers a particular advantage over the others. Evanescently coupled multicore fibers, however, have been studied less extensively due to the relatively small mode area in the single-mode regime. Here, by proposing a new structure with stress-applying parts in a 37-core fiber and optimizing this structure through a comprehensive framework, we present 21 solutions characterized by large-mode-area and high beam quality in the single-mode, single-polarization regime. Different fiber designs are optimal for different output parameters. In one design, the mode area can significantly increase to above 880 μm², which is comparable with that of photonic-crystal fibers. Moreover, besides the single-mode operation, the beam quality factor (M² factor) of the fundamental mode is considered an output parameter in the bent state and is improved up to 1.05 in another design. A comprehensive tolerance analysis is then performed to assess the performance of the designs under deviations from normal conditions. Moreover, in spite of the shifts in the loss of modes, the proposed high beam quality LMA fibers maintain single-polarization, single-mode operation across a wide range of core pitches, bending orientation angles, and bending radius deviations. Our results highlight the potential of multicore fibers for the efficient operation of fiber lasers and amplifiers

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Refractive index sensor based on fano-magnetic toroidal quadrupole resonance enabled by bound state in the continuum in all-dielectric metasurface

Abstract For the first time, an all-dielectric metasurface ultra-sensitive refractive index (RI) sensor with very high quality factor (QF) and figure of merit (FOM), with Fano-magnetic toroidal quadrupole (MTQ) resonance enabled by bound state in continuum (BIC) in terahertz (THz) region was designed. Furthermore, the MTQ resonance in the THz due to a distortion of symmetry-protected bound states in the continuum in the designed structure was investigated. Also, to achieve the dark mode, a combination of three methods including (i) breaking the symmetry, (ii) design of complex structures, and (iii) changing the incident angle was utilized. The broken symmetry in the structure caused a new mode to be excited, which is suitable for sensing applications. The designed metasurface was able to sense a wide range of RI in MTQ resonance, where its properties were improved for the value of sensitivity (S) from 217 GHz/RIU to 625 GHz/RIU, for FOM from 197 RIU–1 to 2.21 × 106 RIU–1 and for QF from 872 to 5.7 × 106

High-performance perovskite solar cell using photonic–plasmonic nanostructure

Abstract In this paper, a coupled optical-electrical modeling method is applied to simulate perovskite solar cells (PSCs) to find ways to improve light absorption by the active layer and ensure that the generated carriers are collected effectively. Initially, a planar structure of the PSC is investigated and its optical losses are determined. To reduce the losses and enhance collection efficiency, a convex light-trapping configuration of PSC is used and the impacts of these nanostructures on all parts of the cell are investigated. In this convex nanostructured PSC, the power conversion efficiency (PCE) is found to be increased when the thickness of the absorbing layer remained unchanged. Then, a plasmonic reflector is applied to trap light inside the perovskite. In this structure, by scattering light through the surface plasmon resonance (SPR) effect of the Au back-contact, the electromagnetic field is found to concentrate in the active layer. This results in increased perovskite absorption and, consequently, a high current density of the cell. In the final structure, which is the integration of these two structures, optical losses are found to be greatly diminished and the short-circuit current density (Jsc) is increased from 18.63 mA/cm2 for the planar structure to 23.5 mA/cm2 for the proposed structure. Due to the increased Jsc and open-circuit voltage (Voc) caused by the improved carrier collection, the PCE increases from 14.62 to 19.54%