As the world’s increasing population and global climate change place unprecedented stresses on Earth’s freshwater systems, microbiological and chemical pollutants in our water will create acute challenges for environmental engineers and public health scientists. Julius Rosenwald (1862-1932) was another self-made wealthy man with whom Washington found common ground and from whom he received much support. By 1908, Rosenwald, son of an immigrant clothier, had become part-owner and president of Sears, Roebuck and Company in Chicago. Rosenwald, a philanthropist, was deeply concerned about the poor state of African American education, especially in the Southern states. Figure 22 illustrates the four possible cases for a circuit element’s voltage and current configuration. According to the convention, if current and voltage are positive, with the arrow and polarity shown in figure 22, energy is absorbed. If either the current arrow or the voltage polarity is reserved, as in (b) and (c), energy is supplied to the circuit. If both the current direction and voltage polarity are reserved together as in figure 22(d), energy is absorbed. Fits, assembles, grinds and shapes metal parts and subassemblies to fabricate production machines and other equipment. Sensors are sometimes referred to as input transducers, and actuators as output transducers. Transducer is a very broad term that refers to any device that converts between an electrical quantity and a real-word quantity. This simple radio frequency (RF) based code lock incorporates a pair of 433MHz ready made RF transmitter and receiver modules. It is a remote-controlled, code-protected lock system. The code is fixedÂ makingÂ it easy to implement. ItÂ requires very less power. You can remotely operate the solenoid lock from 30 metres or more depending on the RF modules used. It is very important to understand the difference between conventional current flow and electron flow. Electrons have a negative charge, and consequently, they move from lower voltage to higher voltage. In Figure 2, however, the arrow indicates that current is flowing from the positive battery terminal to the negative battery terminalâ€”in other words, from higher voltage to lower voltage. Clearly, a broader focus of OSH requires the consideration and application of new skill sets in the field. These include more emphasis on psychosocial factors, human capital, organizational dynamics, education and life-long learning theory, human development, and economic disciplines. Ultimately, not only will a new focus be necessary for OSH practice but also technology may drastically transform the OSH profession in terms of the role of human experts (Susskind and Susskind 2015). Still, there is the need for proactive risk assessment and management of new technologies (Murashov et al. 2016) and the promotion of worker participation in design of technological and organizational innovation (Oeij et al 2017). Protecting the workforce of today and the future, as new technologies are applied, requires taking a holistic view of the hazards they experience and the range of adverse effects that may result.