The main objective of the present study was to investigate the application of Box–Behnken design which is a type of optimization design of response surface methodology (RSM) to predict and optimize some aging condition of magnesium silica aerogel (MSA) for improving surface properties such as surface area, pore volume and pore size. Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) techniques, tap density method and helium pycnometer were used to characterize aerogels. The operating conditions were optimized as a function of the molar ratio of Mg:Si (0.35, 0.50 and 0.65), aging time (24 h, 60 h and 96 h) and aging temperature (50 oC, 70 oC and 90 oC). Lack of fit test indicates that the quadratic regression model was significant with the high coefficients of determination values for all three properties. Optimized aging factors for synthesis MSA with high BET surface area, high BJH pore volume and average BJH pore size were found to be 0.5 Mg:Si molar ratio, 79.62 oC and 61.51 h, respectively. Under these conditions, magnesium silica aerogels have great properties: 734 m2.g-1 BET surface area, 0.41 cm3.g-1 BJH pore volume and 4.91 nm BJH pore size, 0.12 g.cm−3 density and 95 % porosity. Box-Behnken is useful optimization tool for production of nanoporous magnesium silica aerogel.

By combining wood wastes with various binders, construction materials can be produced. These materials can be used in non-bearing parts such as wall block, insulation panel. In this study, prismatic specimens were taken from the mixtures produced considering the chip-cement ratio as 0.25, 0.5 and 1. The unit weight, ultrasonic pulse velocity, bending and compressive strengths of the specimens were determined by using the results of the experiments on these specimens. In addition, specimens were kept at 200 and 400°C for 3 hours in order to determine its behavior under high temperature, which is one of the most important problems for wood composites. With the experiments carried out on the cooled specimens, weight and strength losses, changes in ultrasonic pulse velocity were examined. As a result of the study, while determining that the chip-cement ratio can be used as 1, it is recommended to use the chip-cement ratio up to 0.5 when the high temperature effect is taken into consideration.

The increase in the population day by day and urbanization has led to a rapid increase in the construction sector. With the increase in demand in construction, the product types of building materials are increasing. It is seen that wastes are formed during and after the production of the materials used in the building. This highlights studies on waste management and recycling of waste.  After construction activities, wastes are recycled or converted to secondary products. One of these is wood waste, a traditional building material. In addition to the production of wood furniture, it is used in various areas from the beginning of construction to the end of the building. In this study, sawdust, which is the waste of a woodworking company, was used. Utilizing the advantages of wood, recyclable and sustainable cement bonded wood composite production practices have been explored. It is aimed to produce nature and environment friendly, ecological and economic and durable composite materials. In this research, it is aimed to determine the optimum ratio by using different ratios of sawdust-cement while keeping the water-cement ratio constant in production. The specimens taken from the production were exposed to high temperature after gaining strength. The strength results, unit weights and ultrasonic pulse velocity results of cement bonded wood composite samples exposed to high temperature were examined. Although cement bonded wood composites are exposed to high temperatures such as 400°C, it has been observed that strength is achieved. With this study, an alternative area was proposed for the evaluation of these wastes.