Sharif Digital Repository

Despite the numerous researches in Stress Corrosion Cracking (SCC) risk of austenitic stainless steels in aqueous chloride solution, no formulation or reliable method for prediction of time to failure as a result of SCC has yet been defined. In this paper, the capability of artificial neural network for estimation of the time to failure for SCC of 304 stainless steel in aqueous chloride solution together with sensitivity analysis has been expressed. The output results showed that artificial neural network can predict the time to failure for about 74% of the variance of SCC experimental data. Furthermore, the sensitivity analysis also demonstrated the effects of input parameters (Temperature,... 

Growing nanocrystals in a matrix is a way to have separate, non-agglomerated nanoparticles, which are surface passivated and stabilized against environmental attacks. To create nanocrystals of the desired size and properties in a matrix, it is required that the growth parameters are properly tuned. In this work, we study the growth parameters for ZnS nanocrystals in an SiO2 matrix. Samples were prepared by cosputtering of SiO 2 and ZnS on a silica substrate, followed by annealing at different temperatures. Two categories of samples with low-content ZnS (4 mol%) and high-content ZnS (15 mol%) were examined. In the low-content samples, ZnS nanocrystals are not formed below 900°C annealing... 

It is well known that the quantum Zeno effect can protect specific quantum states from decoherence by using projective measurements. Here we combine the theory of weak measurements with stabilizer quantum error correction and detection codes. We derive rigorous performance bounds which demonstrate that the Zeno effect can be used to protect appropriately encoded arbitrary states to arbitrary accuracy while at the same time allowing for universal quantum computation or quantum control  

A series of nanohybrids using ZIF-8 in the presence of chitosan (CS) at various compositions (0.5–15 wt%) were synthesized. Thorough characterization exhibited that the morphology of the nanoparticles in terms of surface charge, particle size, specific surface area, and pore volume is significantly dominated by the CS content in the hybrid nanoparticles. Amongst the nanoparticles synthesized, a hybrid nanoparticle containing 2 wt% CS, named CS-ZIF-2, represented the largest positive zeta potential and smallest particle size. Moreover, adsorption experiments indicated that CS-ZIF-2 had considerable adsorption capacity against anionic dye (Congo Red, CR) compared with the individual ZIF-8 and... 

Background: Wolfram syndrome (WFS) is characterized by deafness, diabetes mellitus, and diabetes insipidus along with optic atrophy. WFS has an autosomal recessive mode of inheritance and is due to variants in WFS1 and CISD2. Methods: We evaluated the underlying molecular etiology of three affected members of a consanguineous family with hearing impairment, bicuspid aortic valve, diabetes mellitus and insipidus, clinodactyly, and gastrointestinal tract abnormalities via exome sequencing approach. We correlated clinical and imaging data with the genetic findings and their associated phenotypes. Results: We identified a homozygous missense variant p.(Asn1097Lys) in CDK13, a gene previously... 

Background: Wolfram syndrome (WFS) is characterized by deafness, diabetes mellitus, and diabetes insipidus along with optic atrophy. WFS has an autosomal recessive mode of inheritance and is due to variants in WFS1 and CISD2. Methods: We evaluated the underlying molecular etiology of three affected members of a consanguineous family with hearing impairment, bicuspid aortic valve, diabetes mellitus and insipidus, clinodactyly, and gastrointestinal tract abnormalities via exome sequencing approach. We correlated clinical and imaging data with the genetic findings and their associated phenotypes. Results: We identified a homozygous missense variant p.(Asn1097Lys) in CDK13, a gene previously... 

Blazed gratings can reflect an oblique incident wave back in the path of incidence, unlike mirrors and metal plates that only reflect specular waves. Perfect blazing (and zero specular scattering) is a type of Wood's anomaly that has been observed when a resonance condition occurs in the unit-cell of the blazed grating. Such elusive anomalies have been studied thus far as individual perfect blazing points. In this work, we present reflective blazed surfaces that, by design, have multiple coupled blazing resonances per cell. This enables an unprecedented way of tailoring the blazing operation, for widening and/or controlling of blazing bandwidth and incident angle range of operation. The... 

Purpose Whole genome sequencing of SARS-CoV2 is important to find useful information about the viral lineages, variants of interests and variants of concern. As there are not enough data about the circulating SARS-CoV2 variants in Iran, we sequenced 54 SARS-CoV2 genomes during the 5 waves of pandemic in Iran. Methods After viral RNA extraction from clinical samples collected during the COVID-19 pandemic, next generation sequencing was performed using the Nextseq platform. The sequencing data were analyzed and compared with reference sequences. Results During the 1st wave, V and L clades were detected. The second wave was recognized by G, GH and GR clades. Circulating clades during the 3rd... 

Analysis and investigation of the relation between different parts of biological cells such as biomembrane, cytoplasm and nucleus can help to better understand their behaviors and material properties. In this paper, first, the whole elastic properties of mouse oocyte and embryo cells have been computed by inverse finite element and Levenberg-Marquardt optimization algorithm and second, using the derived mechanical properties and the mechanical properties of its bio membrane from the literature, the mechanical properties of its cytoplasm has been characterized. It has been assumed that the cell behavior is as continues, isotropic, nonlinear and homogenous material for modeling. Matching the... 

We disentangle by means of a laboratory experiment two relevant drivers of voluntary payments in Pay-What-You-Want settings: the effects of interpersonal closeness and an audience. Our 2×2 between-subjects design varies the interpersonal closeness of buyers and the observability of their payments by other buyers. This allows us to enrich the research on both drivers and identify whether the presence of close others (closeness effect), payment observability (audience effect), or the combination of both affects voluntary payments. We find that both effects separately are sufficient to increase voluntary payments. Payments are, on average, higher if they are observed by an audience and if... 

Connected and autonomous vehicles (CAVs) have the potential to drastically change the structure of future cities and regions. Researchers predict different outcomes to result from the emergence of CAV technology. While some see their potential as amounting to a complete overhaul of the transport system, others predict the technology will be slow to be adopted and may face competition from other mobility options such as drones. Therefore, the future can be viewed along a spectrum, ranging from no CAVs to a fully driverless transport system. This paper presents an overview of the past attempts on studying CAVs and their impacts to provide a comprehensive view about possible futures with CAVs.... 

Complex product systems (CoPS) industries largely contribute to industrial development, economic growth and creation of national wealth in both developed and developing economies. CoPS also show a number of specific characteristics as a distinctive category of industrial products in comparison with mass-produced consumer goods. These aspects have attracted the attention of scholars to study CoPS over the last two decades, resulting in a fairly extensive body of literature on the subject. However, there is a further need to connect research findings in this area, to illustrate a macro view of the development in the field, explore common themes, and identify possible paths into the future.... 

The influx of solid or liquid particles of drilling mud into the pores of rock or mud loss phenomenon and clay swelling can sometimes lead to severe productive formation damage and cause to wettability alterations of reservoir rock from hydrophilic to oleophilic. Therefore, designing an appropriate fluid that is compatible with formation fluids and could reduce reservoir damage and increase the productivity of wells is very important. The two main mechanisms of surfactants are reduction of the surface tension and wettability alteration of rock reservoir that are effective in taking the oil. Regarding the importance of the wettability in reservoir productivity, this article is aimed to study... 

The influx of solid or liquid particles of drilling mud into the pores of rock or mud loss phenomenon and clay swelling can sometimes lead to severe productive formation damage and cause to wettability alterations of reservoir rock from hydrophilic to oleophilic. Therefore, designing an appropriate fluid that is compatible with formation fluids and could reduce reservoir damage and increase the productivity of wells is very important. The two main mechanisms of surfactants are reduction of the surface tension and wettability alteration of rock reservoir that are effective in taking the oil. Regarding the importance of the wettability in reservoir productivity, this article is aimed to study... 

The most important event following the establishmenet of the Internet network was the Web introduced by Tim Berners-Lee. Websites give their owners features that allow sharing with which they can publish their content with users and visitors. In the last 5 years, we have seen some changes in the use of web. Users want to participate in content sharing and they like to interact with each other. This is known as Web 2.0. In the last year, Web 2.0 has reached maturity and now we need a smart web which will be accordingly be called Web 3.0. Web 3.0 is based on semantic web definition. Changing the way of using the web has had a clear impact on E-Tourism and its development and also on business... 

The Wavelet based speech enhancement is considered. In this method, the noisy signal transfers to wavelet domain. Then with applying a thresholding algorithm, the wavelet coefficients will be improved. At last using the inverse wavelet transform the enhanced signal will be obtained. In this paper, we have presented a new method for thresholding algorithm. We compared our algorithm with some of the most popular methods by several experimental tests. Both subjective and objective tests show better performance and achievements  

Human body is constantly under the influence of acceleration loads in environments such as combat flying. This study investigates the effect of body acceleration on human heart function by using finite element analysis. The nonlinear mechanical behavior of myocardium is modeled by Yeoh hyperelastic model. Stress-strain curves of myocardium are determined based on uniaxial compression tests on bovine heart samples. Nonlinear least square curve fitting is conducted in order to obtain material parameters. Heart geometrical modeling in threedimension is done by segmentation of cardiac MRI images. Obtained material coefficients are assigned to the constructed heart model and appropriate pressure... 

Designers and manufacturers of cryptographic devices are always worried about the vulnerability of their implementations in the presence of power analysis attacks. This article can be categorized into two parts. In the first part, two parameters are proposed to improve the accuracy of the latest hypothetical power consumption model, so-called toggle-count model, which is used in power analysis attacks. Comparison between our proposed model and the toggle-count model demonstrates a great advance, i.e., 16%, in the similarity of hypothetical power values to the corresponding values obtained by an analog simulation. It is supposed that the attacker would be able to build such an accurate power... 

In this study, a review of the overlay/index methods served for delineation of vulnerable zones in coastal aquifers affected by SWI is provided. Then, a more realistic presentation of the vulnerability mapping of coastal aquifers to SWI through modified GALDIT index method by incorporating the influential factors on SWI is established. The modifications on GALDIT method including incorporating the seaward hydraulic gradient (i) instead of the height of groundwater level above sea level (L) (so-called GAiDIT), and considering hydraulic gradient (i) as an additional parameter to the GALDIT (so-called GALDIT-i). Three GALDIT, GAiDIT, and GALDIT-i methods were evaluated with data from three... 

In this work we present a sparse dictionary learning method, specifically tuned to solve the tracking problem. Recently, sparse representation has drawn much attention because of its genuineness and strong mathematical background. In this paper we present an online method for dictionary learning which is desirable for problems such as tracking. Online learning methods are preferable because the whole data are not available at the current time. The presented method tries to use the advantages of the generative and discriminative models to achieve better performance. The experimental results show our method can overcome many tracking challenges