فهرست مطالب vahid mottaghitalab

Current paper has been focused on development of perovskite textile solar cells with mechanical flexibility, low-temperature manufacturing, and cost-effectiveness. Polyethylene terephthalate (PET) has become the substrate of choice compared to other transparent plastic substrates like polyethylene naphthalate (PEN) because it is not only chemically stable but also much cheaper, as an important factor for the photovoltaics (PV) technology development. Herein, spiro-OMeTAD was substituted with CZTS nanoparticles for the first time as an inorganic hole transporting material in flexible perovskite solar cells based on SnO2 electron transport layer. Trough Optimization of CZTS concentration in IPA, the maximum PCE of 2.4% with open-circuit voltage (VOC) of 0.87 V, short current (JSC) of 9.1 mA/cm2 and fill factor (FF) of 30.1% was achieved at a concentration of 15 mg/mL and particle size of 10 nm. The enhanced PV performance of these cells is related to more efficient hole-extraction and reduced carrier recombination, leading to less transport resistance of hole transport layer compared to other concentrations. Subsequently, the flexible cells were successfully embedded on a textile substrate, indicating cells can be seamlessly integrated with portable and wearable smart electronics.

Today، along with the advances in circuit printing technology it has become possible to fabricate band lines integrated with circuit elements. The band lines are known as microstrip lines and the whole packages are called microstrip antennas. The microstrip antennas have three layers، including conductive patch layer، dielectric sub layer، and ground conductive layer. One of the most important problems of prevalent antennas is their inflexibility، which was addressed in the current paper using textile based structure with proper flexibility and flexural stiffness. This was done using ink jet printing techniques followed by electrolytic plating to provide diverse antenna patterns based on nickel particles. The coated surface was characterized by scanning electron microscope، elemental analysis and optical microscope. Moreover، the washing fastness and the other physical and mechanical specifications were measured using standard techniques. The elemental analysis of metal-coated fabric clearly indicated a high level of nickel. Furthermore، the morphological investigation proved the formation of homogenous nickel nanoparticle in a diameter range of 100-500 nm with an evident boundary and semi-spherical shape. In addition، the cumulative presence of particles in a sequence followed a cabbage-like structure originating from metallic crystals. The washing fastness tests revealed a high stability in electrical resistance after several washing steps. In the meantime، the antenna gain and the corresponding bandwidth were measured using spectrum analyzer. The results indicated a 1 kHz increase in bandwidth and 11 dB decrease in antenna gain for a large size compared to a small one. Meanwhile، the bandwidth of rectangular pattern showed a 0. 2 kHz increase and 2. 5 kHz decrease compared to spiral pattern. Finally، the four-probe electrical conductivity test demonstrated a high level of conductivity around 2632 S/cm.

Tissue engineering is an (interdisciplinary field that applies polymeric scaffolds to control tissue formation in three-dinemtion (3D). The scaffold provides the microenvironment (synthetic temporary extracellular matrix) for regenerative cells, supporting cell attachment, proliferation, differentiation, and neo tissue genesis due to their suitable chemical, physical and biological structures. In this study, chitosan/poly (vinyl alcohol) (CS/PVA) was exploited as scaffold for nerve regeneration. Electrospinning was used to fabricate CS/PVA nanocomposites for U373 cells seeding and proliferation. Electrospinning is a versatile and simple method to fabricate non-woven thin layer fibers from polymeric solutions. Consequently, the biocompatibility of CS/PVA nanocomposite was evaluated using biological assays and cell attachment study. Results indicated that CS/PVA nanocomposites with 15/85 proportion shown an almost homogenous network of the electrospun fibers and confirmed that they can be knitted in meshes and improve U373 cells proliferation and cell attachment. The nano-sized CS/PVA scaffolds are nontoxic and biocompatible which can promote proliferation of U373 cells and their appropriate adhesion to nanocomposite for improved peripheral nerve regeneration.