Articles

PLCs, or programmable logic controllers, are essential parts of contemporary industrial automation systems and are responsible for managing and keeping an eye on a variety of operations. PLC reliability is critical to maintaining industrial systems' continuous and secure operation. A wide range of reliability strategies were used to improve the reliability of Programmable Logic Controllers, and this article methodically looks at them all. The evaluation classified PLC reliability techniques into Root Cause Analysis (RCA), Reliability Centered Maintenance (RCM), Hazard analysis (HA), Reliability block diagram (RBD), Fault tree analysis (FTA), Physics of failure (PoF) and FMEA/FMECA, after thoroughly reviewing the body of literature. The proportion of reviewed papers using either RCA, RCM, FMEA/FMECA, FTA, RBD, RCM, PoF, or Hazard analysis to increase the reliability of PLCs showed that RCA, which makes up 20% of the publications reviewed, has been used the most to increase the reliability of the PLC, followed by HA, RCM, RBD, FTA, and PoF, which account for 17%, 16%, 16%,13%, 10%, and 8% of the articles reviewed, respectively. The paper discusses new developments and trends in PLC reliability, such as the application of machine learning (ML) and artificial intelligence (AI) to fault detection and predictive maintenance.

The study assessed knowledge base of food vendors’ hygiene practices in Koforidua in the eastern region of Ghana. As a descriptive survey study, fifty (50) respondents made up of food vendors were purposively and conveniently sampled respectively for the study. The data gathered was analyzed using SPSS Version 17 and converted into frequencies, percentages and tables. This study concluded that street food vendors do have relevant knowledge of hygienic food handling practices through the training they receive, but the knowledge they acquire is not put into practice. The study also revealed that effective and regular inspections by Environmental Health officers will couple stringent enforcement of all regulations governing their practices to streamline the activities of the food vendors for better health of their consumers. It is recommended that the training and certification of food vendors should be organized on a regular basis and should be designed using the Hazard Analysis of Critical Control Point (HACCP). Environmental Health Officers must conduct follow-up exercises after training programmes to ascertain whether food vendors are putting knowledge they have acquired into practice. It is also recommended that, the Metropolitan/Municipal/District environmental health officers should ensure that inspection of street food vendors are carried out effectively, efficiently and regularly so as to monitor the food handling practices of the food vendors’ right from the time of preparation to the point of sale. This is to ensure that food served to consumers is safe for consumption. Vendors who do not put the knowledge they have acquired into practice should have their certificates retrieved and signed up for retraining.