- Underground copper and zinc mine1
- Underground mining1
- Underwater1
- Undesirable facility location1
- Unemployment1
- Unemployment anxiety1
- Unemployment policy1
- Uniform accounting plan1
- Uniform population2
- Unio elangatulus eucirrus1
- Unio elongatulus eucirrus2
- United Nations1
- Unit root test1
- universals1
- Universities7
- University1
- university degree1
- University hospitals1
- University laboratory1
- university life1
- University personnel3
- University ranking1
- University students10
- unmanned aerial vehicles1
- Unsanitary landfill leachate1
- Unsanitary storage1
- Unsteady flow2
- unsupervised machine learning1
- upcycling1
- Updated active fault map1
- Uplift Rate1
- Uptake1
- Uranium1
- Uranyl1
- Urartian Kingdom4
- Urartian tribal centers1
- Urbach's energy2
- Urban archaeology1
- Urban demolition waste1
- Urban flood risks1
- urban heat island1
- Urban mobility1
- urban transport1
- Urban transportation1
- Urban wastewater1
- Urban wastewater treatment1
- urea1
- Urtica dioica L1
- use1
- use of technology1
- Use value7
- UTAUT1
- utilization of artificial intelligence for scientific publication1
- U-type1
- UVeffect1
- UV radiation1
- UV-Vis absorbance1
- Uyum süreci1
- Uyuşturucu alışkanlığı1
- Uzaktan eğitim1