Herd structure in the bovine Calvana breed

Farm structure is one of the principle components that influence profit, sustainability and survival of a herd, especially in endangered breeds. The sustainability of these herds is based on the capability to take advantage of specific niches of the market, of specific label or organic certification or "designation of geographical indications or origin for agricultural products"

Terahertz Metamaterial Optoelectronic Modulators with GHz Reconfiguration Speed

All-electronic ultrafast control of terahertz radiation is demonstrated in integrated metamaterial/graphene devices. By electrostatic gating the graphene conductivity, the overall optical response of the incident terahertz E-field is modified. Depending on the configuration, amplitude, phase, and polarization of terahertz radiation could be modulated with GHz range of reconfiguration speed. An extinction ratio of >7.6 dB in amplitude is achieved at the resonant frequency of 0.75 THz. Additionally, a relative phase shift of >17.4°. is observed around a frequency of 0.68 THz. When operating as a polarization modulator, the device has reported an ellipticity change of ~40% at a frequency of 0.68 THz and a dynamic rotation of the polarization plane by >9°at resonance. The switching capability of the modulators has been investigated all electronically reporting a speed exceeding 3 GHz, only limited by the available instrumentation. Consequently, GHz-speed of modulation can be achieved for frequencies around 0.75 THz. These results represent a breakthrough for all applications where a fast, versatile and efficient modulation of THz radiation is required, such as in next-generation wireless communication, quantum electronics, and ultrafast imaging