Sharif Digital Repository

Single-walled carbon nanotubes (SWCNTs) emit near-infrared (NIR) fluorescence that is ideal for optical sensing. However, the low quantum yields diminish the sensor's signal-to-noise ratio and limits the penetration depths for in vivo measurements. In this study, we perform a systematic investigation of the plasmonic effects of Ag and Au nanoparticles of various geometries to tune and even enhance the fluorescence intensity of single-stranded DNA-wrapped SWCNTs (ssDNA-SWCNTs). We observe a chirality-dependent NIR fluorescence enhancement that varies with both nanoparticle shape and material, with Au nanorods increasing (7, 5) and (7, 6) chirality emissions by 80% and 60% and Ag nanotriangles... 

Providing Quality-of-Service (QoS) in many-core network-on-chip (NoC) platforms is critical due to the high level of resource sharing in such systems. This article presents a hard-built Equality-of-Service (EoS) and Differential-Service (DS) as subsets of QoS in NoC using weighted round-robin arbitration policy. In the proposed technique, packets can be injected with variable initial weights. An enhanced dynamic weight incremental technique is proposed that automatically increases the weights according to the contention degree that packets face along their paths. The proposed technique provides EoS for all packets that are injected with equal initial weights. Furthermore, the router's input... 

We explore whether localized surface plasmon polariton modes can transfer heat between molecules placed in the hot spot of a nanoplasmonic cavity through optomechanical interaction with the molecular vibrations. We demonstrate that external driving of the plasmon resonance indeed induces an effective molecule-molecule interaction corresponding to a heat transfer mechanism that can even be more effective in cooling the hotter molecule than its heating due to the vibrational pumping by the plasmon. This mechanism allows us to actively control the rate of heat flow between molecules through the intensity and frequency of the driving laser. © 2019 American Physical Society  

Design and modeling of a class of scanning near-field optical microscope (SNOM) probe for improving performance are reported. The basic idea is to generate more than one hot spot with well-known spatial distribution. This not only enables one to calibrate out many sorts of errors in conventional SNOM but also results in the increase in the speed of imaging. We utilize plasmonic nanocolor sorter structures to design aperture probes that create two spatially distinct hot spots. The method of moment analysis technique is employed to tune the probe for operation at standard Ar-ion laser wavelengths (457.9 and 514.5 nm). © 2018 Optical Society of America  

An important application of 3-D integration technology is stacked processor-DRAM systems. One of the major design issues in 3-D processor-DRAM stacks is power delivery. Presence of hot spots, high density power regions, in processor die poses serious challenges to the design of power distribution network (PDN). In this paper, we investigate solutions to ensure power integrity in the hot spot regions  

A new method for fluorescent microscopy has been proposed. Proposed method uses indirect excitation of fluorophores with nanometer localized illuminating source. Localized source is created at corners of gold nanotriangles which are deposited on glass substrate. Actually the combination of gold nanotriangle (deposited on glass) acts as active substrate (where species will be placed) for our proposed method. The structure will be scanned with a focused beam of laser (or combination of beams). Due to electric field enhancement in corners and edges of nanotringle (because of surface plasmons), third order nonlinear effect will be enhanced accordingly. Enhancement in third order nonlinearity... 

Traffic models exert different message flows in a network and have a considerable effect on power consumption through different applications. So a good power analysis should consider traffic models. In this paper we present power and throughput models in terms of traffic rate parameters for the most popular traffic models, i.e. Uniform, Local, HotSpot and First Matrix Transpose (FMT) as a permutational traffic model. We also select Mesh topology as the most prominent NoC topology and validate the presented models by comparing our results against simulation results from Synopsys Power Compiler and Modelsim From the comparison, we show that our modeling approach leads to average error of 2%... 

Hypermesh is a promising network topology and is suitable for a range of network-based computing systems. Although there are few models reported for hypermeshes with uniform traffic pattern, no analytical model has been reported to deal with hot-spot traffic. Since many parallel applications exhibit non-uniform traffic patterns such as hot-spots, uniform traffic assumption is not always justifiable in practice. In this study, we propose a new analytical model to predict the mean message latency in wormhole-switched hypermeshes in the presence of hot-spot traffic. The proposed model can also calculate the mean latency under uniform traffic load when the hot-spot ratio is set to zero.... 

Hypermesh is a promising network topology and is suitable for a range of network-based computing systems. Although there are few models reported for hypermeshes with uniform traffic pattern, no analytical model has been reported to deal with hot-spot traffic. Since many parallel applications exhibit non-uniform traffic patterns such as hot-spots, uniform traffic assumption is not always justifiable in practice. In this study, we propose a new analytical model to predict the mean message latency in wormhole-switched hypermeshes in the presence of hot-spot traffic. The proposed model can also calculate the mean latency under uniform traffic load when the hot-spot ratio is set to zero.... 

Plasmonic nanostructures offer great enhancement of the Raman signal due to the strong confinement of the electromagnetic field. Thus, they are considered as suitable candidates for surface enhanced Raman spectroscopy (SERS). In this work, we present an alternative fabrication route, called the glancing angle deposition (GLAD), for tunable fabrication of plasmonic self-organized Ag nanoparticle arrays aimed at SERS. Using the GLAD technique, the inter-particle distance within the arrays can be made as small as 1 nm. Moreover, the plasmonic resonance can be precisely tuned over the whole visible range. The GLAD method can be up-scaled; and when a transparent substrate is used, it enables...