Sharif Digital Repository

In interferometers, the more information about a quantum's path that is available in an ancillary quantum system (AQS), the less visibility the interference has. By use of Shannon entropy, we try to compare the amount of which-phase information with the amount of which-way information stored in the AQS of two-path interferometers with symmetric beam merging. We show that the former is less than or equal to the latter if the bipartite system of the single quantum and the AQS is initially prepared in a pure state and the interaction between the two parts is unitary. The equality holds when symmetry exists. No which-way information is obtained by the measurement that we use for extracting the... 

Hospital ventilation is defined as the providing of fresh and clean air stream in hospital wards or patients’ room to provide and establish a healthy environment for personnel’s and patient’s breath, reducing concentration of produced contaminations in hospital and removing them from clean spaces. Thus, it can prevent spread of airborne infections among patients, people who works around and more importantly, outside the hospital. Hospital infections have a huge influence on mortality of the patients in which respiratory tract infections and surgical wound infections plays a major role. Depending on the quality and the mass flow rate of the exploited air, cleanness of a surgery room can be... 

The ZnO nanowires have been synthesized using vapor-liquid-solid (VLS) process on Au catalyst thin film deposited on different substrates including Si(1 0 0), epi-Si(1 0 0), quartz and alumina. The influence of surface roughness of different substrates and two different environments (Ar + H2 and N2) on formation of ZnO nanostructures was investigated. According to AFM observations, the degree of surface roughness of the different substrates is an important factor to form Au islands for growing ZnO nanostructures (nanowires and nanobelts) with different diameters and lengths. Si substrate (without epi-taxy layer) was found that is the best substrate among Si (with epi-taxy layer), alumina and... 

The field emission properties of MoO2 nanostars grown on a silicon substrate and their emission performance in various vacuum gaps are reported in this article. A new structure of molybdenum oxides, named a nanostar, is grown by thermal vapor deposition with a length of ̃1 μm, a thickness of ̃50 nm, and its width in the range of 500-700 nm. The morphology, structure, composition, and chemical states of the prepared nanostars were characterized by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). According to XRD analysis, the grown nanostructures are composed of both crystalline Mo4O11 and... 

Modern thermal energy storage (TES) systems rely laboriously on finding a low-cost method to improve heat transfer. In the present analysis, adding CuO nanoparticles and tilting the enclosure simultaneously is compared with a novel approach that employed water as a supplemental fluid to improve the melting process using the density difference between PCM and supplemental fluid. Oleic acid is selected as an immiscible PCM in water, which causes PCM and auxiliary fluid utterly separate at the end of the melting process to be usable in more additional TES cycles. By placing water as a heavier material directly on top of oleic acid, the melted oleic acid is replaced by water at the bottom of the... 

Liquid-burning combustion chambers have a wide range of applications in propulsion systems and energy conversion processes. The growing need for reliable and low-NOx combustion systems highlights the role of high-performance burners, where the main design criticalities are related to injectors and swirlers. In the current study, an algorithm for coupling the design procedure of pressure-swirl injectors and axial swirlers is introduced. Also, this algorithm emphasizes the interrelation between the design parameters of these two components via employing the length of the recirculation zone as the coupling parameter for building a relationship between the design characteristics of the injector... 

In this paper an accurate real-time sequence-based system for representation, recognition, interpretation, and analysis of the facial action units (AUs) and expressions is presented. Our system has the following characteristics: 1) employing adaptive-network-based fuzzy inference systems (ANFIS) and temporal information, we developed a classification scheme based on neuro-fuzzy modeling of the AU intensity, which is robust to intensity variations, 2) using both geometric and appearance-based features, and applying efficient dimension reduction techniques, our system is robust to illumination changes and it can represent the subtle changes as well as temporal information involved in formation... 

Facial Action Coding System consists of 44 action units (AUs) and more than 7000 combinations. Hidden Markov models (HMMs) classifier has been used successfully to recognize facial action units (AUs) and expressions due to its ability to deal with AU dynamics. However, a separate HMM is necessary for each single AU and each AU combination. Since combinations of AU numbering in thousands, a more efficient method will be needed. In this paper an accurate real-time sequence-based system for representation and recognition of facial AUs is presented. Our system has the following characteristics: 1) employing a mixture of HMMs and neural network, we develop a novel accurate classifier, which can... 

In this paper, our main purpose is to embed data in the frequency domain of audio signals. Data was embedded by means of Quantization Index Modulation (QIM) in the frequency domain. With this aim, the spectrum of the audio signal was divided into two parts. The first part consisted of the first 19 Barks and the second included the remaining 6 Barks. Each of these parts had a different quantization step size. In order to have large quantization step sizes which yield more robustness, Human Auditory System (HAS) has been used. Decoder detects the watermark signal, without using the original audio signal. Simulation results have shown that this watermarking scheme has better robustness against... 

This research focused on high-performance alkali-activated slag concrete (HPASC) as an overlay material on ordinary Portland cement concrete (OPCC). HPASC specimens were designed with different NaOH molarity, silica fume (SF) content, steel fiber content, age of repair material, and proportion of grooved surface area to the gross area. The results indicated that the steel fibers in HPASC improved the compressive strength and increased the BSS strength. The convolutional neural network (CNN) and multilayered perceptron (MLP) were used to determine a comprehensive model for simulating the effect of each parameter on the BSS shear strength. The simulation results suggest that the CNN, as... 

The field-emission properties of molybdenum oxide nanowires grown on a silicon substrate and its emission performance in various vacuum gaps are reported in this article. A new kind of molybdenum oxides named nanowires with nanoscale protrusions on their surfaces were grown by thermal vapor deposition with a length of ~1 μm and an average diameter of ~50 nm. The morphology, structure, composition and chemical states of the prepared nanostructures were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). According to XRD, XPS, and TEM analyses, the synthesized samples...