Sharif Digital Repository

The pipe-spool fabrication process is a critical operational section in the piping projects that usually used to accelerate and discipline the installation process, especially, when we have a particular deadline for the project. For this reason, the fast and optimal scheduling of the fabrication activities with considering the real conditions and using manual or traditional methods is a significant problem for the decision-makers. In this paper, we use a novel linear programming model to schedule the spool fabrication activities based on the flexible job shop scheduling problem (FJSP). Because FJSP is a challengeable NP-hard problem, we solve the proposed mathematical model with a heuristic... 

Photocatalytic membrane reactors (PMRs), coupling photocatalysts and membranes in a single system, have shown a considerable potential to reduce membrane fouling, which is one of the major drawbacks of using membranes to treat water and wastewater. In this study, the visible light-activated photocatalysts were incorporated into the polyacrylonitrile (PAN) casting solution to synthesize the photocatalytic composite membranes. The physicochemical properties and the morphology of the membranes and photocatalysts were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction analysis (XRD), ultraviolet–visible diffuse reflectance... 

The coupling of photocatalysis with membrane technology, which is known as photocatalytic membrane reactors (PMRs), has received great consideration in recent years and become a promising approach with the high potential to improve the fouling of membranes. In this paper, the photocatalyst of g-C3N4 treated with H2O2 was incorporated with a polysulfone membrane to enhance the anti-fouling properties of the membrane. AFM, FE-SEM images, porosity, and contact angle analysis indicated that the membrane properties like hydrophilicity, porosity, and surface roughness were improved. Also, UV–visible DRS, PL spectra, EIS analysis confirmed that the treated g-C3N4 (H2O2-g-C3N4) had high light... 

In this paper we propose a method for CBIR based on the combination of texture, edge map and color. As texture of edges yields important information about the images, we utilized an adaptive edge detector that produces a binary edge image. Also, using the statistics of color in two different color spaces provides complementary information to retrieve images. Our method is time efficient since we have applied texture calculations on the binary edge image. Our experimental results showed both the higher accuracy and lower time complexity of our method with similar related works using SIMPLIcity database  

Blood cell segmentation is a crucial part of many medical and laboratory procedures such as cell counting and blood cell disorder diagnosis. Among different types of blood cells, white blood cells are the most important clinically, as they suffer greatest from blood disorders. In this paper we propose a method for automatic segmentation of white blood cells nucleus. A distinctive function is used in YCbCr color space to segment the white blood cells nucleus. Next, the sub-images are extracted which contain the whole body of white blood cell nucleus. Then an active contour method is applied to the sub-images extracted from the previous step to accurately segment the cell nucleus boundary. Our... 

Dopamine is one of the most important neurotransmitters released by neurons in the central nervous system, and a variety of neurological illnesses and mental disorders are associated with impairments in the secretion and functionality of dopamine. Dopamine, depending on the type of receptors, can act as a stimulant or an inhibitor. In this study, dendrimer-conjugated dopamine was utilized as a chelating agent for Technetium-99m to investigate the organ distribution of this compound in vivo using the single-photon emission computed tomography (SPECT) technique. For this purpose, dendrimers were synthesized using polyethylene glycol diacid and citric acid precursors, and dopamine was... 

Learning a foreign language encompasses a process of trial and error that can lead to the progression of the learner's interlanguage, meaning that the learners make use of their language knowledge that receives feedback and brings about progress through diagnosis of the problems and being corrected by the teacher. Therefore, there exists a need to analyze the underlying reasons causing the students to remain taciturn with a low willingness to communicate (WTC) during a language class. There has been much work done investigating the role of the learner's stable personal characteristics (traits) along with their situational changes at a specific time (states) that influence the student's... 

Using 3-D scanned data to analyze and extract pore network plays a vital role in investigation of porous media's characteristics. In this paper, a new simple method is developed to detect pores and throats for analyzing the connectivity and permeability of the network. This automated method utilizes some of the common and well-known image processing functions which are widely accessible by researchers and this has led to an easy algorithm implementation. In this method, after polishing and quality control of images, using city-block distance function and watershed segmentation algorithm, pores and throats are detected and 3-D network is produced. This method can also be applied on 2-D images... 

In this paper, we try to recognize and distinguish different groups of arrhythmia using novel features which have been obtained from the heart rate's phase space in recent years. For this purpose, we used Triangular Phase Space Mapping (TPSM) and Parabolic Phase Space Mapping (PPSM). For recognition, we used three groups of 15 subjects using the Physionet database (Arrhythmia, Congestive Heart Failure (CHF), and Atrial Fibrillation (AF)) with Normal Sinus Rhythm (NSR). The obtained features discriminate arrhythmia from NSR by p