Sharif Digital Repository

Thesedays, the electric power industry faces not only increasing electrical demand, but also improving the performance of electrical energy systems. In order to provide these requirements, the concept of smart grid is presented by academic researchers and industry experts. In different parts of a smart grid, the application of various technologies for easy monitoring and control of the system improves its performance. On demand side, making smart is the equivalent of smart consumption management to reduce energy consumption or cost. Considering the high contribution of heating/cooling loads to the energy consumption basket, and the high flexibility of these loads due to thermal inertia, the... 

The advent of nanopore-based sensors based on resitive pulse sensing gave rise to a remarkable breakthrough in the detection and characterization of nanoscale species. The sensors can detect the species’concentration, size, and charge using the resistive pulse characteristics. Some strong correlations have been reported between the resitive pulse characteristics and the particle’s geometrical and physical properties. These correlations are commonly used to obtain information about the particles in commercial devices and research setups. The correlations, however, do not consider the simultaneous effect of influential factors such as particle shape, charge, and off-axis translocation, which... 

Resistive pulse sensing (RPS) has proved to be a viable method for detection and characterization of micro and nano particles. This method works based on ionic current variation inside nanopores. Modern fabrication methods have introduced different nanopore geometries for resistive pulse sensors therefore studing the effects of geometry on sensing performance of nanaopores is important. Numerical simulation has been used to study a wide variation of nanopore’s geometry configurations and study the physics behind this phenomena. Based on the results, numerical simulation could be used as a fast and easy tool for size determination for nanopore. To compare the sensing performance of different... 

This study explores the significance of microfluidics, with a specific focus on the crucial role of droplet microfluidics. A novel microfluidic droplet generator is introduced in this study, employing a centrifuge-based approach. The generator features 2500 micropores on a single membrane, facilitating the production of over 50,000 droplets per second. An extensive investigation into various parameters, including centrifuge speed and micropore size, was conducted to assess their impact on the coefficient of variation in the final droplets. Remarkably, the experimentation resulted in achieving a coefficient of variation below 15 percent. Furthermore, the platform was utilized for synthesizing... 

The aim of this research is to design and optimize integrated microelectrodes on a chip for in-situ acid production and to investigate and utilize the capabilities of machine learning, particularly the reinforcement learning branch and genetic algorithms, in optimizing them with the goal of maximizing the number of electrodes on the chip, while ensuring that each operates independently. Initially, to validate and demonstrate the effectiveness of reinforcement learning using the DDQN algorithm, an agent was trained to optimize the geometric shape of an airfoil with the objective of maximizing the lift-to-drag ratio, showing that the agent can improve this ratio by over 100% in some cases.... 

The resistive pulse sensing (RPS) method based on the Coulter principle is a powerful method for particle counting and sizing in electrolyte solutions. This method involves measuring a current pulse that is produced as a particle transits a small channel, or pore. Throughout its development the technique has been expanded from detection of biological cells to counting nanoparticles and viruses, and even registering individual molecules, e.g., nucleotides in nucleic acids. This technique combined with microfluidic or nanofluidic systems shows great potential for various bioanalytical applications. An increasing number of production methods have been reported to make apertures, which have been... 

In this research, the ability of artificial intelligence to improve the biosensor performance of a microfluidic system has been investigated. Coulter counter is a microfluidic system that measures the concentration of particles in a fluid using signals obtained from a biosensor. The method of this system is called " Resistive Pulse Sensing (RPS)" method. The pulses in the Coulter counter signals are affected by the number, shape, size and speed of particles passing through the orifice. The pulse of two particles of the same size and different shape in these systems are very similar and this makes it difficult for an operator to distinguish the type of particle. Another disadvantage of... 

In recent years, significant attention has been given to methods for measuring micrometer and nanometer biological and synthetic particles using microfluidic systems. One such method is resistive pulse sensing, which is used to detect and count particles as well as determining their surface charge. This technique is based on Coulter's principle. When a micropore is placed in an electrolyte solution containing the target particles, a drop in electric current occurs as the particles pass through the pore. Electrodes on either side of the micropore allow for the analysis of the pulses generated by the particles. Tunable resistive pulse sensing enables the adjustment of the pore size, allowing... 

In this work a new innovative microfluidic system for the selection of motile sperms was developed. The novel aspect of this work is based on the fact the motile sperms follow microchannel walls. Immotile sperms are not able to follow curved paths and therefore their movement toward the outlet gets hindered and most of them could not reach to the outlet. But motile sperms, moving alongside the microchannel walls, reach to the outlet and get separated from the immotile ones. After designing, 3 microfluidic chips having curved microchannels with curvature radius of 150, 300 and 600 micrometer and one with a straight microchannel were fabricated using photolithography and soft lithography.... 

Droplet microfluidic platform generates monodisperse droplets in a desired size through immiscible multiphase flows inside microchannels. Droplets are individual reactor and can be used for bio(chemical) analyses. Also, for materials fabrication, droplet microfluidics offers a versatile platform for generation of nano- or micro-sized particles and microcapsules that are widely used in drug delivery. In addition to the monodispersity, high-throughput generation is also necessary in many applications. Therefore, droplets must be formed in stable regimes (dripping and squeezing) in the highest possible frequency. In this study, the flow-focusing geometry, which is the most common geometry in... 

The growing demand for diagnostic tools with enhanced analytical characteristics in terms of sensitivity, selectivity, and low response time has encouraged researchers to conduct their research towards the development of point-of-care (POC) biosensors. POC diagnostic devices are powerful tools for the detection, diagnosis, and monitoring of diseases at their initial stages. Microfluidic cytometers based on the Coulter principle have recently shown a great potential for POC biosensors for medical diagnosis. One of the most important components in detecting cells by a Coulter counter is a micropore or sensing gate. Therefore, in this study, for counting and sizing the cells using the resistive...