08/19/2023 at 22:10 •
Ozone is a molecule made up of three oxygen atoms (O3) that has a distinct smell and is found in the Earth's upper atmosphere. The history of ozone dates back to the early 20th century when scientists first discovered its existence and its role in protecting the Earth from harmful ultraviolet (UV) radiation. Ozone is used in a variety of applications, including air and water purification, as a disinfectant, and in the production of certain chemicals. It is also used in the treatment of certain medical conditions, such as chronic obstructive pulmonary disease (COPD). Ozone is an important part of our environment and has many beneficial uses.
What does an ozone generator do?
Ozone Generators are a type of air purification system that produces Ozone (O3) to help reduce the presence of airborne contaminants. Ozone's highly reactive composition of three Oxygen atoms allows the molecules to attach to airborne organic contaminants to oxidize and eliminate them.
A patent for producing ozone was filed by one of our inventors, Barend Visser, at the North-West University back in 2004. More information regarding the patent: https://patents.google.com/patent/US7067102B1/en
During the Corona Virus Pandemic, some of our researchers decided to revisit the patent and develop a better version that is IoT-enabled and more efficient.
The new version of the Ozone Generator is based on the ESP-32 chip and produces about 5Gs of O3/hour. They are connected and operated via the Blynk Console and can be set to run at specific times automatically.
A photo of the new version O3 generators:
They are being installed in the labs and lecture rooms all over campus at the moment.
07/14/2023 at 19:12 •
The radiation environment over the African continent, at aviation altitudes, remains mostly uncharacterized and unregulated. In this paper we present initial measurements made by a newly developed active dosimeter on-board long-haul flights between South Africa and Germany. Based on these initial tests, we believe that this low-cost and open-source dosimeter is suitable for continued operation over the Africa continent and can provide valuable long-term measurements to test dosimetric models and inform aviation policy.
The RPiRENA-based active dosimeter
This particle detector works on the same principles as previously assembled dosimeter prototypes. Here, the detection system draws its power from the 3.3 V and 5 V GPIO (general purpose input output) pins from the connected Raspberry Pi (RPi) zero micro-computer, which is in turn powered via a rechargeable power bank.
The instrument draws about 0.4 A of power. Data processing and storage are also performed on the RPi.
The silicone diodes (SDs) are connected to a reversed bias voltage of 45 V to fully deplete the 300 lm thick diodes. When ionizing radiation interacts with an SD a short charge pulse is generated due to the separated charges. However, the charge pulse is too small to be sensed directly.
Therefore, the pulse is ﬁrst sent to the ampliﬁer section of the analogue electronics.
Here, a charge-sensitive ampliﬁer (CSA) ampliﬁes the signals before the resulting pulse is shaped (by the pulse-height shaper, PHS), and then it is digitized by a 16-bit analogue-to-digital converter (ADC). A ﬁeld programmable gate array (FPGA) is programmed to periodically sample the ADC signals and detect the peak voltage (i.e. the pulse height). Since the pulse height is proportional to the energy deposited, the ADC value is proportional to the energy deposited in the detector after the appropriate calibrations are performed.