Sharif Digital Repository

In this research binuclear platinum(IV) complexes with coinage metals have been synthesized and characterized. the trimethyl platinum(IV) complex [PtMe3(phthalazine)3]+X- has been prepared by the reaction of [PtMe3(THF)]4 with 3 equiv. phthalazine and used as initial material. The first complex, [PtMe3(µ-(phthalazine)2Cl)PtMe3], synthesized via reaction of 2 equiv. [Pt(Me)3(Phthalazine)3] with 1 equiv. [AuClSMe2]. The second complex, [PtMe3(µ-phthalazine)3Ag][BF4], synthesized by reaction of one equiv. of each compound [Ag(CH3CN)4]BF4 and [Pt(Me)3(Phthalazine)3] And the third complex, [PtMe3(µ-phthalazine)3Cu][PF6], synthesized like second one via reaction of [Cu(CH3CN)4]PF6 and... 

Planar visibility computing is defined as determining the region of the plane that is visible from a specific observer. This concept has many applications in computer graphics, robotic and computer games. In this thesis we consider two visibility problems: the visibility testing problem which checks the inter-visibility of two objects and the visibility counting problem which counts the number of visible objects from an observer. For these problems we propose new algorithms which have some improvements compare to the previous ones  

A simple, fast and sensitive method based on microextraction in packed syringe (MEPS), a new format of solid-phase extraction (SPE), as a sample preparation technique in off-line combination with gas chromatography-mass spectrometry (GC-MS) was developed. Polyaniline (PANI) nanowire network was synthesized and used as sorbent of MEPS for the multiresidue determination of selected analytes from triazine, organochlrorine and organophosphorous pesticides in aqueous samples. The PANI nanowires network was prepared using soft template technique and its characterization was studied by scanning electron microscopy (SEM). The use of micelles in this methodology has an important role in the shape of... 

Design and development of Unmanned Aerial Vehicles (UAVs) has been a hot topic in the past decades. In particular, Vertical Take Off & Landing Vehicles (VTOLs) have been extensively studied and are under constant development. Quad rotors are one of the major subcategories of VTOLs and a lot of effort have been devoted to their control optimization. In the present study, we have utilized a novel transformer quad rotor structure that can change the angle between its arms. This structural change is a type of design feature modification that can effect the moments of inertia by changing the flight dynamics of quad rotor. Modification of height difference between adjacent rotors, while avoiding... 

Planar visibility computing is defned as determining the region of the plane that is visible from a specifc observer. This concept has many applications in computer graphics, robotic and computer games. In certain visibility problems, counting the number of visible objects in an appropriate time is required. For obtaining a solution fast, current algorithms give an approximated count. In this thesis, we consider visibility testing problem and visibility counting problem.For a given set S = fs1; s2; :::; sng of non-intersecting segments and a query point p in the plane, the visibility testing problem checks the inter-visibility of p and a segment si 2 S and the visibility counting problem... 

Due to compability of Magnesium with the body, it is a suitable material for making biodegradable stents, Althogh, its mechanical properties are not desirable for stent application. Accordingly, lately, magnesium’s microstructure and mechanical properties have been improved using various methods, including the process of severe plastic deformation (SPD). Many severe plastic deformation methods have been introduced for the fabrication of ultrafine grain tubes till now, which the process of tubular channel angular pressing (TCAP) is the most effective one. In the first part of the research, Magnesium tubes with a thickness of 1 mm were processed using the TCAP with a trapezoidal channel, and... 

Form and angularity of aggregates are two important shape characteristics that have a significant effect on the performance of hot-mix asphalt. The first step toward the study of the effect of these characteristics on pavement performance is their proper measurement. Current test methods used in practice have several limitations in measuring these characteristics. In this thesis, a method based on image processing called “Sharif Aggregate Imaging System (SHAMS)” has been introduced which is capable of directly measuring aggregate dimensions and determining angularity index for aggregates classification. Calculated results related to the form and angularity of aggregates measured by SHAMS... 

Vocabulary knowledge is one of the main building blocks in the process of learning a new language and presents many challenges to language learners. Using computer software and online programs is suggested as possible approaches for overcoming some of these challenges. In the present study, the researcher attempted to study the effect of creating and sharing different sets of online flash cards on the use of vocabulary items among Iranian English for Academic Purposes (EAP) students. Thirty-nine university students in two groups participated in this study (29 males, 10 females). One group were instructed to create online flash cards containing the definitions of words and their synonyms and...