Quality of coastal water is of great importance in environment and other applications. Therefore, studying the quality of this water is quite vital. Traditional methods of water quality studies are time consuming processes that lead to pixel-based information and also impose a great deal of costs. Using satellite images and remote sensing can play an important role in enhancing the outcome of these studies. In this research, by field sampling of secchi depth, simultaneous to the satellite pass; an experimental statistic-mathematical model was fitted for the acquired data in the field and the processed images of the IRS-LISS-III sensor. The results indicated good relations between the Secchi depth and the radiance received by the sensor. The fitted model can be used to map Secchi depth in coastal areas.

Cyanate esters are one the most suitable matrixes for production of high temperature composites with carbon fibers due to their excellent thermo-mechanical properties. Since the curing of this resin has a high heat release, applying a suitable curing cycle has the ability to control the heat release during the curing. Cyanate ester provides high adhesion to carbon fibers even in less resin content, so cyanate ester can be used as a matrix for preparing advanced composites. 2,2'-bis(4-cyanatophenyl)propane resin was synthesized by the reaction of cyanogen bromide and bisphenol A. The synthesized resin was characterized by FT-IR, 1H-NMR and 13C-NMR spectroscopies. The curing behavior of cyanate ester resin was determined by DSC and a suitable curing cycle was defined and it’s efficiency was monitored by FT-IR. Cyanate ester/carbon fiber composite with 30% and 44% resin contents was prepared and their ILSS was determined and thermal and mechanical properties were investigated by DMTA and TGA. The defined curing cycle for 2,2'-bis(4-cyanatophenyl)propane had the ability to control the high heat release of cuing reaction with the curing ability of the resin up to 95.6%. Cyanate ester has a high adhesion to carbon fibers in the composite even in the relatively low resin content 30%. Hence, the amount of ILSS was increased about 9% compared to the ILSS for composite with 44% resin content. At temperatures as high as 250 °C, composite had only 16% decrease in flexural modulus. The cyanate ester/carbon fiber composite had a char yeild of 82.6%.

Cyanate esters are one the most suitable matrixes for production of high temperature composites with carbon fibers due to their excellent thermo-mechanical properties. Since the curing of this resin has a high heat release, applying a suitable curing cycle has the ability to control the heat release during the curing. Cyanate ester provides high adhesion to carbon fibers even in less resin content, so cyanate ester can be used as a matrix for preparing advanced composites. 2,2'-bis(4-cyanatophenyl)propane resin was synthesized by the reaction of cyanogen bromide and bisphenol A. The synthesized resin was characterized by FT-IR, 1H-NMR and 13C-NMR spectroscopies. The curing behavior of cyanate ester resin was determined by DSC and a suitable curing cycle was defined and it’s efficiency was monitored by FT-IR. Cyanate ester/carbon fiber composite with 30% and 44% resin contents was prepared and their ILSS was determined and thermal and mechanical properties were investigated by DMTA and TGA. The defined curing cycle for 2,2'-bis(4-cyanatophenyl)propane had the ability to control the high heat release of cuing reaction with the curing ability of the resin up to 95.6%. Cyanate ester has a high adhesion to carbon fibers in the composite even in the relatively low resin content 30%. Hence, the amount of ILSS was increased about 9% compared to the ILSS for composite with 44% resin content. At temperatures as high as 250 °C, composite had only 16% decrease in flexural modulus. The cyanate ester/carbon fiber composite had a char yeild of 82.6%.

Hypothesis: Bismaleimide resin, due to its favorable mechanical and thermal properties, can improve the properties of epoxy resin. 4,4'- Bis(maleimido)diphenylmethane resin (BMI) is one of bismaleimide resins that can be cured simultaneously with epoxy resin by amine curing agents and both resins can be cured with the same curing cycle. This improves the physical-mechanical properties of epoxy-based composites.Methods: BMI resin was synthesized using the reaction between maleic anhydride and 4,4'-diaminodiphenyl methane in acetone to form an intermediate of amic acid. The dehydration of the amic acid was carried out to form an imide using acetic anhydride, triethylamine and sodium acetate. The product was characterized by FTIR and 1H NMR spectroscopy techniques. The synthesized resin was blended with DGEBA epoxy resins in different amounts of 10, 20, 30 and 40 phr. Next, the blends were cured by 4,4'-diaminodiphenyl methane as a curing agent, and the composites were prepared from the blends and glass fibers. The interlaminar shear strength (ILSS) of the prepared composites was measured as a key parameter of composites. The curing behavior of epoxy/bismaleimide blend was investigated using isothermal differential scanning calorimetry (DSC) and FTIR spectroscopy.Findings: 4,4'-Bis(maleimido)diphenylmethane resin was used to improve ILSS properties of the composite prepared based on DGEBA epoxy resin and glass fibers. The value of 52.50 MPa was obtained as the optimum value of ILSS at 78°C for the mixture with 30 phr of bismaleimide. DGEBA and BMI resins have the ability to simultaneously cure by 73% and 78% using MDA curing agent at 160°C. Full curing of the epoxy and bismaleimide mixture requires a temperature higher than 160°C, such as 220°C.

Nomex sandwich structures are highly preferred in aerospace applications for their combination of lightweight and robust design. These panels feature Nomex honeycomb cores sandwiched between composite face sheets, usually made of CFRP or fiberglass, providing outstanding strength-to-weight ratios. The heat-resistant properties of Nomex enhance their suitability for aerospace environments, maintaining structural integrity even under high temperatures. These structures find application in aircraft fuselages, wings, and interior components, enhancing performance while minimizing weight. In this study, the effect of dispersing 30B nano clay in epoxy resin on the shear strength and flexural strength of Nomex honeycomb sandwich panels with CFRP skins and Nomex cores was investigated. Initially, 30B nano clay was dispersed in epoxy resin using two methods: ultrasonic mixing and high-speed stirrer, at weight percentages of 0.5%, 1%, 3%, and 5%. Then, three-point bending specimens were fabricated to assess interlaminar shear strength, fracture toughness, and flexural strength. Adding nano clay to the epoxy resin resulted in increased fracture toughness, with the highest toughness achieved at 1% weight percentage in both mixing methods. Moreover, nano clay increased the interlaminar shear strength, particularly with a carbon substrate. However, due to reduced adhesion between the substrate and resin, the interlaminar shear strength decreased compared to pure resin. The flexural strength results showed that adding a resin layer to the sandwich specimen increased strength and flexural modulus by up to 20%.

In the presen study, the effect of carbonate calcium (CaCO3) loading and CaCO3 modification on the interlaminar shear strength (ILSS) and flexural properties of carbon fiber/epoxy composite was investigated. Firstly, CaCO3 was functionalized with 3-glycidoxypropyltrimetoxysilane (3-GPTMS), which was confirmed by Fourier transform infrared (FTIR) spectroscopy. The CaCO3 nanoparticles were infused into carbon fiber/epoxy composite at various contents (0. 5, 1, 3, and 5 wt. % with respect to the matrix) using ultrasonication and standard mixing routes. The results of mechanical tests showed that adding 3 wt. % silanized-CaCO3 improved the ILSS, flexural modulus, and flexural strength of the carbon fiber/epoxy composite by 25%, 36%, and 27%, respectively. Micrographs of fracture surface analysis confirmed that the carbon fiber/matrix interfacial bonding can be improved significantly by incorporating the silanized CaCO3 nanoparticles. The ILSS, flexural modulus, and flexural strength of the silanized CaCO3/carbon fiber/epoxy composite were greater than that of unmodified CaCO3/carbon fiber/epoxy composite. These results indicated that the silane-modified CaCO3 dispersion within the matrix of fibrous composites plays a key role to achieve high performance composites.

The influence of autoclave cure vacuum on the microstructure and mechanical properties was studied for a woven carbon fiber/epoxy resin composite laminate, AS4/8552S. The laminates were cured at vacuum pressures varied from 0 to –,0. 08 MPa. Their corresponding thickness, density, resin volume fraction, fiber volume fraction, and void content were established accordingly as a function of vacuum pressure. The combined loading compression and short beam shear mechanical tests were determined at 120 °, C. The results showed that thickness, density, laminate compressive strength (LCS), and interlaminar shear strength (ILSS) varied exponentially with applied vacuum pressure and reached a steady state at the applied vacuum of –,0. 04 MPa. However, applying this vacuum level improved thickness, density, fiber volume fraction, and void content by approximately 42. 10, 50. 97, 46. 69 and 99. 84%, respectively, compared to that found without a vacuum bag. Pearson's correlation analysis revealed linear variation in ILSS and LCS modulus with density, fiber volume fraction, void content and between laminate compressive modulus (LCM) and density. One-way ANOVA statistical analysis showed that the most critical parameters affecting ILSS are density and void content. It is also shown that all physical microstructural parameters affect LCS, whereas density and fiber volume fraction are the most significant parameters affecting LCM.

Purpose: The main aim of this study was to determine the cost-utility of the integrated systems in the Iranian academic libraries.Methodology: This applied research was conducted through a survey method. The statistical population consisted of 118 academic libraries among which 75 libraries were selected using stratified sampling method. The researcher-made questionnaire was distributed among them. Finally 73 questionnaires were collected and the related data were analyzed using descriptive and inferential statistics by SPSS.Findings: Security and functionality were the most important priorities of choosing ILS by the libraries. Amongst the evaluated ILSs, Payam-e-Mashregh was the least costly system and the self-made systems were the most costly ones. Besides, Payam-e-Mashregh was the most satisfactory system while the least satisfaction was with the self-made systems. Finally, Payam-e-Mashregh had the best cost-utility ratio.

The degree of impregnation directly impacts the ultimate strength of thermoplastic composite (TPC) prepreg. To understand this relationship, an experimental procedure was developed to investigate key factors such as maximum interlaminar shear strength (ILSS), void content, and fiber volume fractions, which influence the residual strength of TPC prepreg. Additionally, three types of dies (A, B, and B+) were produced and examined for injection methods and direct pultrusion of commingled (COM) and side-by-side (SBS) wires. Factors like the fiber/void fraction ratio (Vf/Vv), ILSS, and ILSS/Vf were used to compare the impregnation capacity of each die and production method. The results revealed that the COM method achieved the maximum degree of impregnation, while the SBS method yielded the minimum. A remarkable correlation between the fiber fraction and void fraction was also observed, highlighting the accuracy of the Vf/Vv ratio in assessing impregnation quality. This research provides valuable insights into the factors affecting the residual strength of TPC prepreg and emphasizes the importance of optimizing impregnation techniques for enhanced composite performance. In this context, the samples with a 1% void volume fraction within a higher fiber volume fraction of 60% would demonstrate superior impregnation capacity compared to another sample with the same void volume fraction of 1% but a lower fiber volume fraction of 30%