There is little information about environmental contamination with antibiotic resistance genes (ARG) in Sub-Saharan Africa, home to about 1 billion people. In this study we measured the abundance of three genes (sul1, sul2, and intI1) used as indicators of environmental contamination with ARGs in the sediments of four urban wetlands in southwestern Nigeria by qPCR. In addition, we characterised the variable regions of class 1 integrons in sulfamethoxazole/trimethoprim (SMX/TRI)-resistant bacteria isolated from the wetlands by PCR and DNA sequencing. The indicator ARGs were present in all wetlands with mean absolute copy numbers/gram of sediment ranging between 4.7x10 6 and 1.2x10 8 for sul1, 1.1x10 7 and 1x10 8 for sul2, and 5.3x10 5 and 1.9x10 7 for intI1. The relative abundances (ARG/16S rRNA copy number) ranged from about 10 −3 to 10 −1. These levels of ARG contamination were similar to those previously reported for polluted environments in other parts of the world. The integrase genes intI1 and intI2 were detected in 72% and 11.4% SMX/TRIresistant isolates, respectively. Five different cassette array types (dfrA7; aadA2; aadA1| dfrA1; acc(6')lb-cr|arr3|dfrA27; arr3|acc(6')lb-cr|dfrA27) were detected among 34 (59.6%) intI1-positive isolates. No gene cassettes were found in the nine intI2-positive isolates. These results show that African urban ecosystems impacted by anthropogenic activities are reservoirs of bacteria harbouring transferable ARG.

Spray tools with multi-nozzle-arrays are used in a wide variety of applications. Monitoring the functionality of complex spraying tools with a large number of individual nozzles is a great challenge. For this purpose, we have developed a measurement technique based on the wetting pattern, which forms on a surface during spray impingement. To investigate the performance of this measurement technique we applied a spraying tool with nine external mixing air-water nozzles, the geometric alignment of which can be freely adjusted. In the first test series, the precision of the evaluation of the nozzle alignment is determined. The second test series focuses on the individual sizes of the wetted areas. Here the reproducibility, the influences of the operating modes and the nozzle type were evaluated. Subsequently, the functionality is tested in an exemplary test case in which two of nine nozzles were readjusted in a defined manner. Finally, the wetting pattern resulting from injecting a full spray is discussed and the necessary image processing steps are provided. In summary, this measuring system allows efficient, fast and cost-effective control and documentation of the alignment and functionality of spraying tools, thereby avoiding production downtime and related costs.

In casting technology spraying tools are used for cooling and cleaning purposes. Its heavy use is often accompanied by contamination and misalignment of the nozzles, which leads to the production of rejects and to production downtime. Therefore, control systems are necessary to check the function of the nozzles and in case of a problem to find the defect. From this starting point, we develop a new robust measuring technique. This measurement technic is based on the optical visualisation of the spray impingement on a frosted pane. A camera detects the resulting characteristic wetting pattern. From the camera recordings, conclusions can be drawn about the alignment and the mass flow of individual nozzles. To test the capabilities of the measurement method, we used a spray tool with 9 nozzles and equipped with different nozzles as shown in Figure 1. For this we have measure the position of spray impact and the size of the wetted area of the individual spray plumes on the frosted pane surface. As a result, we are able to show that the measurement results are reproducible and the measurement method achieves high sensitivity.

Multi-nozzle spraying tools are applied in numerous industrial applications, one of the most common being die-casting. To ensure the quality of a cast product and to avoid production downtimes proper functioning is required, e.g. in terms of spray targeting, mass flow, or reproducibility. To enable regular functional controls of a spraying tool, we have developed a specific measuring principle based on monitoring the spray impact on a heated plate using infrared thermography. In this paper, the performance of the developed measuring principle is examined. The study is performed with a typical spraying tool from foundries, it has nine external mixing air-water nozzles, which are freely adjustable in their orientation. During an injection, the spray impacts a heated plate positioned in front of the spraying tool and creates a wetting pattern that is individual to each spraying tool, like a fingerprint. The recorded cooling pattern can be used to determine the position of the individual spray impact areas, the size of the spray impact areas, and the intensity of the cooling. Based on these parameters, conclusions can be drawn about the functionality of the water-bearing lines and the air-bearing lines − as well as the correct alignment of the individual nozzles. The result shows that the presented measuring principle leads to very high precision and reproducibility of the evaluated parameters. Thus, the developed measuring system enables detailed functional tests of complex spraying tools.