Abstract: Passive dehumidifiers for environmental control units (ECUs) are presented. In embodiments, the passive dehumidifier may include a plenum with an intake to receive an airflow with moisture (e.g., water droplets, water vapor, etc.) present. Upon entering the passive dehumidifier, the airflow may experience a reduction in inertia and a change from a first direction to a second direction. The directional change may be sharp enough (e.g., greater than 90 degrees) that the moisture in the airflow are not able to follow the airflow and are instead directed to impinge and be collected on a collector wall, which may include one or more hydrophilic surfaces facilitating the impinged water droplets to form a liquid film upon impact on the collector wall. The film may collapse due to gravity and may be drained out through and/or on a hydrophilic screen mesh (e.g., hydrophilic screen mesh surface) on the collector wall surface(s).

Abstract: The present invention process involves the exposure of antiperspirant salt solutions to ultraviolet light to cause lightening in color. The ultraviolet light can be in the wavelength range of 180 to 400 nanometers, with the longer wavelengths preferred and at an exposure time of 1 to 120 minutes. The color of the antiperspirant solutions treated with ultraviolet light approaches the color of water, commonly known in the cosmetic industry as water white. These exceptionally low color antiperspirant salt solutions are useful in development of clear and colorless antiperspirant gels, roll-ons and stick formulations.