Sharif Digital Repository

Bones adapt their form and structure to make an efficient use of their mass against the applied mechanical loads. So, it is not surprising to assume that the geometry and density distribution of a bone contains information about its loading history. The objective of this work was to develop a framework to simulate the bone remodeling procedure as a topology optimization process and then use this framework to develop a simple technique for estimating the dominant joint loads based on the bone’s density distribution.
At first, the remodeling equation was derived from the structural optimization task of minimizing the strain energy in each time step, using the level set method. Employment... 

Coral reefs are one of the most important ecosystems in terms of animal diversity and affect the life of organisms in different ways. This ecosystem is under many stresses today. Among the most important events that threaten corals is the event of coral bleaching, the most important cause of which is the increase in Sea Surface Temperature (SST). Therefore, it is highly important to monitor changes in SST affecting corals. Generally, temperature anomalies are investigated using the Degree Heating Weeks index (DHW) and SST data. DHW index is variable in different coral areas and changes with time. Consequently, in the present study, this index has been investigated due to the lack of... 

In 2009, a general equation of state (EOS-III) based on an effective near-neighbor pair interaction of an extended Lennard-Jones (3, 6, 12) type has been introduced as : , where is the compressibility factor, p and ρ stand for pressure and molar density , respectively, T is Temperature , and e, f and g are the temperature dependent coefficient of the equation of state . the Z_th and Z_in are the thermal and internal contributions of pressure in the compressibility factor, respectively. this equation of state gives a good description of all types of nano- and bulk –solid and bulk fluid at entire temperature and pressure ranges for which thee is experimental data. Investigation show that... 

In the extension of his former developments of the theories of philosophy of mind and language, John Searle (1932- ) proceeded into the realm of social reality by his The Construction of Social Reality and Making the Social World, written in 1995 and 2010 respectively. With his naturalistic background, he placed his new theory on top of his former theories of mind and language already naturalized and fully worked out. As we will see, social reality comes with our three marvelous capacities, not coming together, to the extent we know, in animals other than us: collective intentionality, assignment of function, and language; all of them already being treated by Searle, in a naturalized manner,... 

The rise in carbon dioxide levels has led to the manifestation of numerous environmental challenges. Currently, the absorption and conversion of carbon dioxide into valuable fuel resources such as synthetic gas, methane, and ethylene are deemed crucial from both environmental and economic standpoints. Despite the presentation of photocatalysts such as titanium oxide and electrocatalysts such as copper, silver, and zinc, their efficiency in CO2 conversion is found to be insufficient. One potential solution to this problem is the utilization of photoelectrocatalytic CO2 recovery. In this study, the aim was to enhance the photoelectrocatalytic reduction of CO2 by designing and manufacturing... 

Sohail Inayatullah is one of the most successful futurists of the last decade. His proposed method for futures studies, which is called Causal Layered Analysis (CLA), has attracted a lot of attention and has won futurists’ admiration. Although, Wendell Bell counts the study of epistemological foundations of futures studies as one of the major purposes in this field, unfortunately, no significant attempt has been made to clarify the epistemological foundation of CLA, up to this time. The primary purpose of this thesis is to relieve this weakness. Inayatullah calls his approach, in developing CLA, “critical”. On the other hand, Wendell Bell claims that Roy Bhaskar’s “critical realism” is an... 

In this work, the in-motion estimation of Euler angles of a strapdown inertial navigation system is studied using a speedometer, as an aided navigation sensor. First, the derivation of governing error equations has been done. Then, the most appropriate heuristic filters available in references have been chosen for this study. Among this filters, unscented particle filter, that has better performance and conditions for the real-time implementation, has been chosen. Then, an innovative solution for improving the performance of this filter is presented. The proposed filter uses particle swarm optimization to resample the particles. The proposed... 

In recent years, much attention has been paid to the preparation of nanoparticles as carriers for drug delivery. Nanoparticle carriers, by changing the pharmacokinetic properties of the drug, improve the function of the drug and reduce its side effects. In the manufacture of nanoparticles, various materials such as polymers, metal particles, lipids, etc. are used to transfer the drugs, which can produce a different shape and size of the particles depending on their production method. The purpose of this project is the synthesis of liposomal nanoparticles (as nano-carriers) to load an antibiotic (Eucalyptus oil) and study the release of the encapsulated drug in the simulated environment of... 

An accurate numerical methodology for capturing the field quantities a center lamellar inhomogeneity within the interface of two different phases of a bimaterial rectangular plate subjected to non-uniform tensile stress, in the context of reproducing kernel particle method (RKPM), is of particular interest. For this purpose the innovative numerical technique, so-called extended augmented corrected collocation method is introduced; this technique is an extension of the augmented corrected collocation method used for imposing continuity condition of the displacement at the interface. The robustness of this methodology is shown by solving problems of material discontinuities, namely plates... 

Massive-MIMO and C-RAN are the two technologies which will be among most important parts of fifth generation (5G) stsrems. They will find widespread uses in future years. However, data transfer rate between these two technologies is a challenging problem. Also channel estimation is crucial in massive-MIMO systems. In this research, the problem of estimating the channel and the problems with the data transfer rate between these two technologies are investigated. We propose using 1-bit quantizers to solve the rate problem and also an algorithm with perfect performance in aspect of error rate is proposed. The mentioned algorithm is implemented on GPUs, which are available at C-RANs and resulted... 

Self-excitation vibration or chatter in the milling process is one of the most critical factors in reducing the tool life and surface smoothness. With the change of tool speed or depth of cut, bifurcation phenomena occur at some points (bifurcation points) such that the system behaviour becomes unstable and the chatter is observed. In this study, using nonlinear modelling for cutting forces, two main methods for active control of this process are proposed. The first is an intelligent control based on emotional learning, which is a model-free strategy. In this method, the critic generates a signal (stress signal) using error and its derivative. The purpose of this controller is to reduce the... 

Linear position sensors are widely used in linear motion-control drives. In this thesis, the design, optimization, performance analysis, and prototyping of a linear variable reluctance, variable area resolver is discussed. To test the new design approach of the studied sensor, three-dimensional time-stepping finite element analysis (3-D TSFEA) is crucial. However, the 3D TSFEA is a very time-consuming method which leads to an inappropriate choice for co-using with optimization algorithms. Hence, an accurate analytical model based on a winding function (WF) method presented in favor of calculating the inductances, air-gap flux density, induced voltages precisely and yet is a very fast method,...