Design and operation of torpedo tubes installed on German U-Boats during WWII did not differ greatly from other such designs in the world. They used pressurized air to launch the torpedo and automatic venting after the launch.
These quarantinable diseases include cholera, diphtheria, infectious tuberculosis, plague, smallpox, yellow fever, viral hemorrhagic fevers, severe acute respiratory syndrome, and influenza caused by novel or reemerging influenza viruses that are causing or have the potential to cause a pandemic.
A chronic condition is a human health condition or disease that is persistent or otherwise long-lasting in its effects or a disease that comes with time. The term chronic is usually applied when the course of the disease lasts for more than three months.Common chronic diseases include arthritis, asthma, cancer, COPD, diabetes and viral diseases such as hepatitis C and HIV/AIDS. In medicine, the opposite of chronic is acute.A chronic course is further distinguished from a recurrent course; recurrent diseases relapse repeatedly, with periods of remission in between.ommon chronic diseases include arthritis, asthma, cancer, COPD, diabetes and viral diseases such as hepatitis C and HIV/AIDS. In medicine, the opposite of chronic is acute.