Design and implementation of grid-connected photovoltaic power plant with the highest technical Efficiency

Energy is a necessity and the basis of human life. With the increase in the need for energy supply in recent years, the use of fossil fuels has intensified. Environment is a basic principle for human beings. In our dear country Iran, with an average sundial of approximately 4.5 hours per day, there is the highest potential for the use of photovoltaic systems. Connected to the national power grid as a micro grid, in accordance with the standardization and the highest efficiency with PVsyst software, the system losses were identified and the necessary solutions were provided to solve them. In case of using 1 to 5 kW systems, which due to small It can be installed even on the roofs of houses. In hot cities, where electricity consumption increases in the hot seasons of the year, the pressure is removed from the national electricity distribution network, and a significant amount of greenhouse gas emissions to the environment is prevented. At the end by plotting the current value of the project it was also proven to be economical

Transparent Solar Panel Antenna Array

This dissertation research presents a comprehensive study to answer the question of “Can it be possible to integrate a high gain optically transparent antenna array directly on top of solar cells?”. The answer to such question is extremely important in space exploration where very small satellites have been extensively employed. Due to their small mass and size, those small satellites create challenges for one to mount the antennas, and the challenge is further increased when a high gain antenna is need for more communication capacity. Based on feasibility studies, the dissertation concludes that it is possible to do such an integration, and then proceeds to present the approaches for design and integration. On the element level, the thesis presents research in assessing the effects between a planar antenna integrated on the solar cell and the photovoltaic cell. A series of experiments were designed to perform assessments for antennas operating from C to X bands. It is concluded that a commercial triple junction space–certified solar cell normally would decrease the gain of the antenna to 2–3 dB and is not affected by the working states of solar cells. The shadow of the antenna casts on solar cells, however, is not significant (less than 2%). The thesis also provides a model of a common space solar cell that helps to explain the gain loss. The model was validated by experimental data, and it was utilized to predict iv a possible custom design of solar cell where with a minimal design modification, it would facilitate less gain loss of the antenna integrated on top. On the array level, the research surveys different high gain antenna array design and then focus on an optimal sub–wavelength reflectarray design. The final antenna array design is a 30 cm by 20 cm, X band (8.475 GHz) reflectarray that shows 94% transparency, 24 dB gain, and higher than 40% aperture efficiency. The design is then prototyped and tested on actual solar panel. The measurement of the reflectarray placed on the solar panel showed a gain of 22.46 dB and an aperture efficiency of 29.3%. While those results are considered excellent, the thesis continues to address the reasons for reduction of the antenna’s performance due to the solar panel, through both theoretical analysis and experiments

The Behavior of Rectangular and Circular Reinforced Concrete Columns under Biaxial Multiple Excitation

The aim of this study is to investigate the dynamic performance of rectangular and circular reinforced concrete (RC) columns considering biaxial multiple excitations. For this purpose, an advanced nonlinear finite element model which can simulate various features of cyclic degradation in material and structural components is used. The implemented nonlinear fiber beam-column model accounts for inelastic buckling and low-cycle fatigue degradation of longitudinal reinforcement and can simulate multiple failure modes of RC columns under dynamic loading. Hypothetical rectangular and circular columns are used to investigate the failure modes of RC columns. A detailed ground motion selection is implemented to generate real mainshock and aftershocks. It was found that multiple excitations due to aftershock has the potential of increasing the damage of the RC columns and longitudinal reinforcements are significantly affected low-cycle fatigue. Also, it was found that rectangular column is more sensitive to accumulative damage due to cyclic fatigue. This study increases the accuracy of structural analysis of RC columns and consequently improves understanding the failure modes of RC columns with different cross-sectional shapes

Does length-weight equation fit clupeid fishes? An evaluation of LWRs for six clupeids from Iran (Teleostei: Clupeiformes)

This study investigates length–weight relationships of six clupeid species (Alosa braschnikowi, Alosa caspia, Dussumieria acuta, Nematalosa nasus, Sardinella albella and Tenualosa ilisha) captured from three main water bodies of Iran (Persian Gulf, Oman Sea and Caspian Sea), to evaluate if the LWR parameters fit for these fishes having specific morphological characteristics. Based on the obtained results, i) the b value was influenced by recorded length (TL, SL, FL) and body shape, ii) it was within the expected range of 2.27–3.48, iii) length–weight relationships were highly correlated and significant (r2>0.82-0.98, P<0.001), and hence length-weight equations fit well with six clupeid species in the Iranian water bodies. The results presented here, would be useful for fishery biologists and fisheries stake-holders in the study area

Birth prevalence of genital anomalies among males conceived by intracytoplasmic sperm injection cycles: A cross-sectional study

Background: Several studies have been conducted worldwide to evaluate the prevalence and relative risks of congenital anomalies associated with assisted reproductive technology cycles; however, there is limited data in Iran. Objective: To investigate male genital anomalies among live births from assisted reproductive technology. Materials and Methods: This cross-sectional study was conducted on children born after intracytoplasmic sperm injection (ICSI) at Royan Institute, Tehran, Iran from April 2013-December 2015. The prevalence of male genitalia disorders that included hypospadias, epispadias, cryptorchidism, micropenis, and vanishing testis were reported. The relationship between the cause of infertility and type of embryo transfer (fresh or frozen), gestational age at birth (term or preterm), and birth weight with these male genitalia anomalies were evaluated. Results: In total, 4409 pregnant women were followed after their ICSI cycles to evaluate genitalia anomalies in their children. Out of 5608 live births, 2614 (46.61%) newborns were male, of which 14 cases (0.54%) had genital anomalies. The prevalence of various anomalies were cryptorchidism (0.34%), hypospadias (0.038%), micropenis (0.038%), vanishing testis (0.038%), and epispadias (0.077%). No relationship was found between the cause of infertility, type of embryo transfer (fresh or frozen), gestational age at birth (term or preterm), and male genital malformation (p = 0.33, p = 0.66, and p = 0.62, respectively). Conclusion: The prevalence of each male genital anomaly after the ICSI cycle was rare and less than 0.5%; however, no significant infertility-related factor was observed with these anomalies. Key words: Cryptorchidism, Hypospadias, Microinjections, Prevalence, Reproductive techniques, Urogenital abnormalitie

A Study on the Effect between Commercial Space Solar Cells and the Antennas Integrated on Their Cover Glass

A study to determine how commercial space solar cells affect the functionality of the antenna integrated on top of solar cells has been performed. The measured results show that solar cell affects the antenna gain and decreases it by approximately 3 dB at 5GHz. In addition, the pattern of the antenna was not affected significantly by solar cells whether when they were illuminated and terminated with different loads

Synthesis, characterization, and evaluation of nano-hydroxyapatite based experimental calcium silicate cement as a root repair material

Introduction: This study aimed to prepare a new root repair material including Portland cement, bismuth oxide, and nano-hydroxyapatite and analyze its physicochemical properties and its effects on the proliferation and differentiation of human dental pulp stem cells (hDPSCs). Material and Methods: Bismuth oxide as a radiopaque component and nano-hydroxyapatite particles were added to white Portland cement at 20% and 5% weight ratio, respectively. Characterization of the prepared cement was done using con-ventional methods. To examine the bioactivity of this new material, atomic absorption spectroscopy (AAS) was used for the investigation of the rate of calcium ions dissolution in simulated body fluid media. The viability of hDPSCs was assessed by an MTT assay after 1, 3 and 7 days. The odontogenic potential of this substance was evaluated by measuring alkaline phosphatase activity and alizarin red S staining. Results: Based on the bioactivity results, the cement presented high bio-activity, corroborating sufficiently with the calcium release patterns. The cell viability was significantly increased in new root repair ma-terial containing hydroxyapatite nanoparticles after 3 and 7 days (p<0.05). Conclusion: Moreover, alkaline phosphatase activity increased over 7 days in all experimental groups. The new cement containing nano-hydroxyapatite particles could be a good root repair material

Curcumin Nanocrystals: Production, Physicochemical Assessment, and In Vitro Evaluation of the Antimicrobial Effects against Bacterial Loading of the Implant Fixture

Background: This study aimed to prepare and study physicochemical properties as well as the antibacterial action of curcumin nanocrystals inside the implant fixture against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Enterococcus faecalis (E. faecalis). Methods: Curcumin nanocrystals were prepared via precipitation combined with the spray drying method. The produced curcumin nanocrystals were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Moreover, the in vitro antimicrobial effect of curcumin nanocrystals inside the implant fixture was assessed against E. coli, S. aureus, and E. faecalis. All implant-abutment assemblies were immersed in bacterial suspensions and were incubated at 24, 48, and 72 h. The contents of each implant were cultured to count the colony of bacteria at 37 ◦C for 24 h. Results: The prepared curcumin nanocrystals with a mean particle size of 95 nm and spherical morphology exhibited a removal rate of 99.99% for all bacteria. In addition, the colony-forming unit (CFU) of bacteria in exposure to nanocrystals significantly was reduced (p < 0.010) by increasing the time. Conclusions: Curcumin nanocrystals can be used inside the implant fixture as an antimicrobial agent in order to more stabilization of the implant

Effect of Sport Shoe Weight on Gait Kinetics in Athletes With Anterior Cruciate Ligament Reconstruction During Walking

Background and Aims Different shoe weights affect the gait mechanics. Some dynamic changes or adjustments induced by anterior cruciate ligament (ACL) reconstruction can be assessed through the analysis of the ground reaction forces (GRFs). This study aims to determine the effect of sports shoe weight on gait kinetics in athletes with ACL reconstruction.Methods Twenty healthy men and 20 athletes with ACL reconstruction volunteered to participate in this study. Each participant performed three walking trials with shoes having light (weight: 150±18 g), moderate (300±18 g), and heavy (450±18 g) weights in a randomized order. The GRFs were analyzed during shod walking. Results The GRF component at vertical direction during the heel contact phase changed significantly during the use of shoes with different weights (P=0.001). In addition, the GRF at vertical direction during the push-off phase and GRF at mediolateral direction during the push-off phase increased significantly (P=0.023 and 0.014, respectively).Conclusion The biomechanics of lower limbs and the GRFs are significantly different when using light and heavy shoes during the heal contact and push-off phases of walking