Sphere Sandwich Structures (SSS) are a new structure which may have the potentials to provide the energy absorption as compared with monolithic specimen material. By using innovation carving wax method, fifteen specimens have been prepared according to RSM optimize method and it machined by CNC-3axis machine with sphere end screw. Three factors sphere diameter(D), distance between spheres(X) and skin thickness(K) have been studied. The impact test has been achieved by Izod test to calculate specific fracture toughness. The results show the sample 642 has the highest specific fracture toughness value with an improvement of 300% compared with the monolithic sample. The optimal value of this test is 35.37 MPa m0.5 g-1 of the sample 682 (diameter = 6, distance between spheres = 8, skin thickness = 2 mm) with 10% error when compared with practice result at the same geometry. According to ANOVA analysis, the diameter of sphere(D) has greatest effect than other factors and then skin thickness(K).

The main idea of this research is to design a rechargeable paper battery from local cheap and available materials. The practical part is represented by adding Polyvinyl alcohol (PVA) to conductive polymer (PSS PEDOT) with adding different mineral salts for then study the quantum of electrical conductivity and heat influence on electrical conductivity and acidity factors of the Electrolyte solution.The next step was to produce a rechargeable, flexible battery manufactured from regular cellulose paper, sulfone, and ionic solution.The measurements were made using modern laboratory devices to study the electrical properties, conductivity, resistance (Hall Effect), and voltage quantum of the ionic solution. Through the results we obtained, we noticed an increase in the conductivity of the ionic solution when adding mineral salts. The voltage quantum of one battery ranged between 0.3-0.3 volts, also several batteries were connected in series, and the result was 1.8 volts. Manufactured paper batteries can be recharged with a direct current source and recover their efficiency marked up 98-99%.

This paper deals with synthesizing of nanocomposites of unsaturated polyester (UP) filled with nano silica and investigation the effect of silica content on the tribological behavior of UP and nanocomposites. Silica nanoparticles were prepared by burning rice husk ash (RHA) as an agricultural waste material. Three different percentages as 2%, 6% and 10% of nano silica were added to the unsaturated polyester and dispersed by using ultrasonic waves method. As a result of agglomeration and sedimentation of nano RHA particles, dispersing by ultrasonic waves was very effective to terminate these challenges. X-Rays diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM) technics were used for characterization of materials. RHA-UP nanocomposites were tested for their tribo-performance by pin-on-disc machine. XRD demonstrated that white rice husk ash consists of amorphous silica. SEM demonstrated that silica particles were distributed uniformly and well embedded within the polyester matrix. Results showed an improvement in wear resistance with relatively stable friction coefficient with the addition of 10% nano silica. Adding 2 wt% nano RHA negatively affected the wear resistance of RHA-UP nanocomposite .The best tribological performance of 10% RHA-UP nanocomposites achieved at load 10N. Incorporation of RHA with unsaturated polyester has advantages of reducing pollution, making the pollutant RHA as a valuable material to produce low cost and lightweight products with modified properties. Silica enriched RHA could prove to be cheaper anti-wear additives for producing high performance unsaturated polyester composites such as brake pads.

Sandwich Structure with pin core is widely used in foam core for crushing, debonding and interfacial delamination prevention; this structure has manufactured by drilling foam core frequently. On the other hand, a novel method for manufacturing a pin core sandwich structure has been the aim of this research. Machinable wax panel was used to achieve cavities in form of pin within the core by drilling the wax panel by CNC-drilling machine then casting of thermoset resin (unsaturated polyester resin) into a wax mold, after that melting of the wax mold to get pin core sandwich structure. Complex structure can't be designed by conventional method but by this method allows to design such complex structures: spheres, pyramids, ellipse…etc. According to Response Surface Methodology method, fifteen specimens were achieved and three variables were investigated to get optimization and prediction model. The results show that 300% improvement of stiffness performance index with 40% weight reduction comparative to reference sample with 4.46 GPa0.5 cm3 g-1 optimal value for the specimen ((High=11mm), (Diameter=9 mm) and (Pin-to-Pin distance=4.3 mm)). Strength performance index improvement is 126% and 50% weight reduction comparative to reference sample with 35.9 MPa2/3 cm3 g-1 optimal value for the specimen ((High=11mm), (Diameter=6.115 mm) and Pin-to-Pin distance=1.5 mm)). ANOVA analysis shows that the pin height (H) is effective parameter on stiffness property. On the other hand, the height and diameter of the pin are effective parameters on strength property.