Keep in mind that any voltage, by definition, is a difference in electric potential energy between two points. So while we may say that a voltage source has a voltage of 1.5V, we are actually saying that the voltage between the negative and positive polarities of the voltage source is 1.5V.
Jacksonville, Texas. As of the census[1] of 2000, there were 13,868 people, 4,882 households, and 3,358 families residing in the city. The population density was 981.0 people per square mile (378.7/km2). There were 5,397 housing units at an average density of 381.8 per square mile (147.4/km2).
Duval County, Florida. Duval County is a county located in the State of Florida. As of the 2010 census, the population was 864,263, with a 2016 estimate at 926,255. Its county seat is Jacksonville, with which the Duval County government has been consolidated since 1968. Duval County was established in 1822, and is named for William Pope Duval, Governor of Florida Territory from 1822 to 1834. Duval County is included in the Jacksonville, FL Metropolitan Statistical Area.