To apply a new waterproofing membrane on top of an old bitumen waterproofing membrane, the surface of the old membrane should be thoroughly cleaned and prepared. Any loose debris, dirt, or old adhesive should be removed to ensure proper adhesion of the new membrane. Once the surface is clean, a primer should be applied to promote adhesion between the old and new membranes. Finally, the new waterproofing membrane can be installed according to the manufacturer's instructions, ensuring that it is properly sealed and bonded to the old membrane to provide effective waterproofing. **

A utility knife or a sharp blade is typically used to cut the waterproofing membrane. It is important to use a sharp tool to ensure clean and precise cuts, which will help in achieving a proper seal and prevent water leakage. Care should be taken to avoid damaging the underlying surface while cutting the membrane. **

Airplane windows are designed to block most of the harmful UV rays from the sun, so the likelihood of getting sunburned through a window is very low. However, it is still possible to get sunburned if you are sitting by a window for an extended period of time, especially at higher altitudes where UV rays are stronger. It is always a good idea to wear sunscreen or protective clothing if you are sitting by a window on a plane for a long duration. **

To reflect a plane on the plane x1x3, you would first find the equation of the plane you want to reflect. Then, you would substitute x2 with -x2 in the equation to reflect it across the x1x3 plane. This means changing the sign of the coefficient of x2 in the equation of the plane. The resulting equation will be the reflection of the original plane across the x1x3 plane. **

To reflect a plane across the plane x1x3, you can first find the equation of the mirror plane x1x3. Then, for each point on the original plane, you can find its reflection across the mirror plane by using the formula for reflecting a point across a plane. This involves finding the perpendicular distance from the point to the mirror plane and then using that distance to find the reflected point. By applying this process to all points on the original plane, you can obtain the reflected plane across the x1x3 plane. **

Airplane windows are typically made of materials that block most of the harmful UV rays from the sun. This means that you are unlikely to get a sunburn from sitting by the window on a plane. However, it is still possible to get some sun exposure through the windows, especially if you are on a long flight or sitting by a window for an extended period of time. It is always a good idea to wear sunscreen or protective clothing if you are concerned about sun exposure while flying. **

Airplane windows are designed to block most of the harmful UV rays that can cause sunburn. However, it is still possible to get a sunburn on a plane if you are sitting near a window for an extended period of time, especially at higher altitudes where UV rays are stronger. It is always a good idea to use sunscreen or cover up with clothing if you are sitting by a window during a flight to protect your skin from potential sun damage. **

Ideally, the waterproofing membrane should be applied in dry weather to ensure proper adhesion and effectiveness. If the membrane is applied and then it rains before it has fully cured, it can compromise its ability to create a watertight seal. Water exposure during the curing process can lead to delamination, reduced adhesion, and potential leaks. Therefore, it is best to apply the waterproofing membrane when there is no rain in the forecast and allow it to fully cure before any water exposure. **