Sharif Digital Repository

With the rise of the concept of “Big Data”, both data volumes and data processing time increased, imposing the need for new methods of processing and computation of said data.Analytical and computational methods in Machine Learning are some of the most important applications of Big Data processing. There exist many methods of data analysis in the Machine Learning field, each requiring extensive processing on Big Data. One of the methods for working with Big Data is Distributed Systems. MapReduce is one of the most popular methods distributed computation by increasing the ease and speed of distributed processing of big data. But a number of bottlenecks have been discovered in MapReduce which... 

In this thesis we introduce Tropical Geometry and It’s Application in Arithmetic Geometry  

In this research, Al-20Si-5Fe-1Mg-xMn(x= 0,3,6) ribbons were produced by Melt spinning method. Microstructure and growth morphology of ribbons were studied by optical microscope (OM), scanning electron microscope (SEM) and X-ray diffraction (XRD). The results were compared with as cast samples. In OM results, two different zones were observed. Featureless zone (with planar growth morphology) and dendrites zone. Microstructure of ribbons were completely different from the as cast samples. It consisted of just Aluminium and silicon. XRD results approved that matter. In fact, high solidification rate of ribbons increased the solubility of silicon and other alloys in aluminium and consequently... 

In recent years, indirect methods of cancer detection that utilize changes in trace element levels in various parts of the body, such as hair and nails, have garnered significant attention from researchers.The primary objective of these methods is to identify alterations in trace element levels that serve as biological markers in the presence of disease. While direct examination of affected organs remains the gold standard for cancer diagnosis, it is often expensive, time-consuming, inconvenient, and associated with potential side effects. Therefore, if the effectiveness of this approach is validated, it could serve as a cost-effective, non-invasive, safe, and early diagnostic method in... 

The aim of this research is to develop a smart mesoporous bioactive glass-based carrier for targeted drug delivery to cancer cells, particularly bone cancer cells. To achieve this, mesoporous bioactive glass nanoparticles were first synthesized, followed by surface modification with amine groups. To prevent premature drug release before reaching the target tissue and to introduce pH sensitivity, the nanoparticle pores were coated with oxidized hyaluronic acid via Schiff-base bonding with the amine groups on the surface. The use of hyaluronic acid facilitates active targeting of CD44 receptors, which are overexpressed on the surface of cancer cells compared to healthy cells. This process... 

The present work describes sensing application of modified Pt nanostructures towards detection of glucose. Modified Pt nanostructured electrodes were prepared using electrodeposition method such as chronoampermetry and potentiostatic pulse methods. The electrodeposition of Pt nanostructures was first studied by voltammetry and amperommetry techniques and then potentiostatic pulse method has been used to produce the alloyed structures of platinum. In this regard, the first electrode was proposed based on alloyed Pt/Ni nanowire arrays (NWAs) for the non-enzymatic detection of glucose. The Pt/Ni NWAs were prepared by pulse electrodeposition of Pt and Ni within a nano-pore polycarbonate (PC)... 

Any physical system is characterized with some set of quantities or parameters, knowing which, is equivalent to estimation of the system. Evaluating such parameters is usually done using tomography methods. An important question to ask, is how to increase the precision of measurement, being able to do some specific set of physical operations, say, measurement?
this question is more important in parameter estimation in quantum meanical systems. It has been shown that, quantum meanics causes a fundamental limit, on precision of estimating su parameters, escribed by the so called “antum Cramér-Rao bound”.We must note that almost all quantum meanical systems are interacting with the... 

Improvement of semiconductors photocatalytic activity by different means has always been one of the challenges for researchers. Semiconductors doping for band-gap engineering and changing morphology to increase specific surface area and photocatalytic reaction sites are amongst these efforts. In this research simultaneous effect of these two parameters for three morphologies containing nanoparticle, nanowire and micro dandelion, simultaneously doped with carbon and nitrogen has been investigated. Final purpose of this thesis is to decrease the band-gap energy close to soft UV photon energies to make surface photodynamic therapy possible. Nanoparticle morphology with size distribution between... 

In this study, chitosan-based nanoparticles were prepared due to their biocompatibility, availability, high loading capacity of drug, stimulus responsive behavior and the presence of active functional groups. Chitosan was chemically functionalized with reactive oxygen species (ROS)-responsive moiety to respond to the oxidative stess and endosomal pH in nerve injuries. To prepare nanoparticles, functinalized chitosan ionically gelated with pH-responsive polyanions with ROS-scavenging properties such as polyacrylic acid and hyaluronic acid. Then, pH- and ROS-responsive nanoparticles were used for selective transfection into reactive astrocytes and axonal regeneration in spinal cord injuries.... 

Internet is the largest multi-purpose, self-reliant, complex and distributed computer network across the globe. The nodes of this network are placed in every place like homes, offices, military camps, schools and all other locations by utilizing many different communication protocols, media and capacities. Furthermore, by rapid technology development, there are many newly born applications utilizing internet in new ways such as Internet of Things systems. The explosive growth of technology causing accelerated addition of new nodes to the internet, and any new single node may have several new unpatched vulnerabilities. This is a serious issue for managing this vast chaotic configuration and...