Called a swing, it is the movement that does something when, after completing a walk, it takes a step back and retraces the course in the opposite direction. For example: “He watched the clock’s pendulum swing for long minutes, oblivious to those around him”, “He hit the sandbag for the last time and left without looking at his swing”, “The swing of the trees, product of the wind scared the girl”.
The sea makes a typical back-and-forth motion. With each wave that reaches the shore, the sea advances on the sand, but then retreats. In this way, in front of those on the beach, the sea moves back and forth.
Continuing with the theme of the sea, the process known as desalination consists of removing salt from its water, and for this, desalination plants are used, thanks to which man obtains drinking water, so necessary for life. One of the biggest problems with desalination is its high cost, which is why many researchers do not rest in the search for cheaper alternatives. This is the case of Chris Matthews and Justin Sonnett, two students at the University of North Carolina, who in 2015 presented a project for a desalination plant that only needs the balance of waves to work . The name of this system is SAROS , abbreviation for Swell Acuated Reverse Osmosis System , and it was designed to serve those who do not have access to fresh water. This salinizer has reduced dimensions, which facilitates its movement and location in different areas of the sea, since it only needs the aforementioned water balance to work. Regarding the structure of SAROS, which consists of buoys at its base, which allow it to float, and a pendulum that moves with the swing of the waves and feeds a propulsion system, thanks to which the water is subjected to a pump of high. Pressure through a reverse osmosis membrane. Finally, the produced drinking water is stored in tanks until extraction. It is important to note that conventional desalination plants require a large amount of electrical energy to operate, while SAROS manages to generate the energy from the water itself, and this particularity makes it a highly environmentally friendly and convenient creation from the point of view. .from an economic point of view. If we add its self-sustaining nature to its small size, we understand that we are faced with an affordable and convenient system. The notion of reciprocal is also used in reference to the instability, oscillation, or fluctuation of a thing. In this case, the idea of oscillation is associated with something negative since the lack of stability implies a risk: “The ups and downs of the economy worry citizens”, “I hope that we will soon overcome this oscillation and get back on the path of growth” , “Since we got married, our relationship has gone through several ups and downs”.
Take the case of the economy of two countries. If, in country X, the Gross Domestic Product (GDP) grew by 8% in 2011, 5% in 2012, 7% in 2013 and 6% in 2014, the national economy showed stability in these years. Instead, country Z’s GDP grew by 1% in 2011, dropped by 3% in 2012, increased again by 2% in 2013 and dropped by 6% in 2014: so it can be said that the economy has shown a worrying balance. Life is full of ups and downs, in all its aspects, from the emotional plane to the economic situation, and we must face them with courage and maturity to move forward. In the best of cases, the experience that the countless battles provide us prepares us to less and more the impact of these comings and goings.