Sharif Digital Repository

High throughput AES encryption/decryption is a necessity for many of modern embedded systems. This article presents a high performance yet cost efficient AES system. Maestro can be used in a wide range of embedded applications with various requirements and limitations. Maestro is about one million times faster than the pure software implementation. The Maestro architecture is composed of two major components; the soft processor aimed at system initialization and control, and the hardware AES engine for high performance AES encryption/decryption. A ten stage implicit pipelined architecture is considered for the AES engine. Two novel techniques are proposed in design of AES engine which enable... 

Autologous grafts, as the gold standard for vascular bypass procedures, associated with several problems that limit their usability, so tissue engineered vessels have been the subject of an increasing number of works. Nevertheless, gathering all of the desired characteristics of vascular scaffolds in the same construct has been a big challenge for scientists. Herein, a composite silk-based vascular scaffold (CSVS) was proposed to consider all the mechanical, structural and biological requirements of a small-diameter vascular scaffold. The scaffold's lumen composed of braided silk fiber-reinforced silk fibroin (SF) sponge covalently heparinized (H-CSVS) using Hydroxy-Iron Complexes (HICs) as... 

In this work, the electrophoretic deposition method was utilized to immobilize TiO2 particles on stainless steel substrates. In addition, for the first time, statistics-based experimental design using response surface methodology was employed to investigate the effect of four key coating parameters (i.e. applied voltage, calcination temperature, photocatalyst weight percentage, and deposition time) on the photocatalytic degradation. Analysis of variance revealed that the proposed model was adequate. X-ray diffraction and scanning electron microscope were used to evaluate the effects of the parameters on degradation efficiency. The optimum applied voltage, calcination temperature, catalyst... 

In this research work, different devices made of glutaraldehyde cross-linked chitosan hydrogels loaded by amoxicillin, have been prepared using freeze-drying method. Effects of system parameters such as cross-linker concentration, pH, and gel structure on the morphology and release behavior of devices have been investigated using standard methods. Morphological studies were performed using SEM instrument and controlled releases are followed via spectrophotometeric method. Reaction of glutaraldehyde with chitosan has been studied using FTIR instrument. SEM micrographs have shown that with increasing cross-linker percentage in hydrogel, pore sizes increased where pore size distribution... 

The wear-out of flash-based Solid-State Drives (SSDs) is a main concern that significantly affects their reliability. One major parameter that accelerates SSD wear-out is the number of write-cycles committed to flash chips. The number of write-cycles in SSD-based disk subsystem is highly dependent on the erasure code implemented in Redundant Array of Independent Disks (RAIDs). In this paper, we investigate the impact of erasure codes and the configuration of storage subsystems (i.e., the number of disks participated in the RAID array and stripe unit size) on the endurance of storage systems. The number of write-cycles is considered as a metric to evaluate the endurance of storage system. We... 

The Graphics Processing Unit (GPU) is the most promising candidate platform for faster rate of improvement in peak processing speed, low latency and high performance. The highly programmable and multithreaded nature of GPUs makes them a remarkable candidate for general purpose computing. However, supporting non-graphics computing on graphics processors requires addressing several architecture challenges. In this paper, we focus on improving performance by better hiding long waiting time to transfer data from the slow global memory. Thereupon study an effective light-overhead prefetching mechanism, which utilizes idle processing elements. Our results show that we can potentially improve... 

In this paper, we present a novel routing algorithm in order to avoid deadlock and packet dropping. In our proposed algorithm the network-on-chip (NoC) is capable of tolerating faults in presence of control faults in combinational parts of routers. In addition, by modifying the functionality of the router, the router is enabled to test its own, as well as the preceding router's functionality based on the routing algorithm, destination address and previous router's situation. Each router recognizes the faulty neighbor and announces it to successive routers. In this scheme no extra packets will be generated. We analyze the effects of our method on latency, power consumption and drop rate. Our... 

In this research, partitioning of β-amylase and amyloglucosidase was investigated in polymer-salt aqueous two-phase systems containing poly(ethylene glycol) (PEG) with different molecular weights such as 4000, 6000 and 10,000 and Na2SO4 or KH2PO4. The experimental partition coefficients were measured at T = (298.5, 301.5, 303.5, 305.5 and 308) K. The results showed that the concentration of salt in feed had more effect on partition coefficients of β-amylase and amyloglucosidase in aqueous two-phase systems than the concentration of polymer in initial feed. Also, the results indicated that temperature had a small effect on partitioning of β-amylase and amyloglucosidase enzymes. The partition... 

A batch extraction of an essential amino acid, Phenylalanine, from an aqueous solution of different concentrations by an Emulsion Liquid Membrane (ELM) was developed using D2EHPA as a cationic carrier, Span 80 as the surfactant, paraffin and kerosene as the diluents, and HCl as the internal electrolyte. All effective parameters such as pH of initial aqueous external phase, electrolyte concentration in aqueous internal phase, carrier and surfactant concentration in emulsion, volume ratio of the organic to aqueous internal phase (Roi), volume ratio of the W/O emulsion to aqueous external phase (Rew) and time were examined and optimized using Taguchi method which was the first time of... 

Drug loading in electrospun nanofibers has gained a lot of attention as a novel method for direct drug release in an injury site to accelerate wound healing. The present study deals with the fabrication of silk fibroin (SF)-chitosan (CS)-silver (Ag)-curcumin (CUR) nanofibers using the electrospinning method, which facilitates the pH-responsive release of CUR, accelerates wound healing, and improves mechanical properties. Response surface methodology (RSM) was used to investigate the effect of the solution parameters on the nanofiber diameter and morphology. The nanofibers were characterized via Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron... 

Cancer has long been a leading cause of death. The primary tumor, however, is not the main cause of death in more than 90% of cases. It is the complex process of metastasis that makes cancer deadly. The invasion metastasis cascade is the multi-step biological process of cancer cell dissemination to distant organ sites and adaptation to the new microenvironment site. Unraveling the metastasis process can provide great insight into cancer death prevention or even treatment. Microfluidics is a promising platform, that provides a wide range of applications in metastasis-related investigations. Cell culture microfluidic technologies for in vitro modeling of cancer tissues with fluid flow and the... 

Background and Objective: Probiotics are dietary supplements with potential health benefits for humans when consumed regularly at appropriate quantities. The latest evidence shows possible beneficial effects of probiotics in COVID-19 treatment. Interests in probiotic consumption have led to provide products such as probiotic juices with vitamins, minerals, prebiotics and appropriate levels of probiotics to the market in free and encapsulated forms, which are not fully addressed in scientific literatures. The objective of this review was to investigate effects of probiotics for the management of human health. Other objectives included study on effects of free and encapsulated forms of... 

Background and Objective: Probiotics are dietary supplements with potential health benefits for humans when consumed regularly at appropriate quantities. The latest evidence shows possible beneficial effects of probiotics in COVID-19 treatment. Interests in probiotic consumption have led to provide products such as probiotic juices with vitamins, minerals, prebiotics and appropriate levels of probiotics to the market in free and encapsulated forms, which are not fully addressed in scientific literatures. The objective of this review was to investigate effects of probiotics for the management of human health. Other objectives included study on effects of free and encapsulated forms of... 

This paper presents a novel approach to speech recognition using fuzzy modeling. The task begins with conversion of speech spectrogram into a linguistic description based on arbitrary colors and lengths. While phonemes are also described using these fuzzy measures, and recognition is done by normal fuzzy reasoning, a genetic algorithm optimizes phoneme definitions so that to classify samples into correct phonemes. The method is tested over a standard speech data base and the results are presented. © 2005 IEEE  

v.1. Structural engineering and earthquake engineering.-- v.2. Geotechnical engineering.-- v.3. Transportation, civil engineering materials, construction management.-- v.4. Water resources and environmental engineering, surveying and mapping