Biochar particles size influenced the yield and water productivity of two mint (Mentha sp.) varieties under drip irrigation

In a two-year experiment conducted in 2019 and 2020, evaluation of the interaction between biochar particle sizes (without application (B1), <1 mm (B2), 6.60-9.50 mm (B3) and >13 mm (B4)) and irrigation treatments (120 (I1), 100 (I2) and 80% (I3) ETo) on yield, water use efficiency (WUE) and water productivity (WP) of two mint varieties (spearmint (V1) and peppermint (V2)) was done in the new soil of El-Behira Governorate under drip system. The results showed that, in both cuts, application of I1 and B4 increased the fresh yield by an average of 16.6 % for varieties and seasons, compared to other treatments. The highest oil yield was increased by an average of 28.0% for varieties and seasons under B2 and I3, compared to other treatments. The highest applied irrigation water was 11655 m3/ha under I1 averaged over varieties and seasons, which attained the highest yield under the application of the four biochar treatments. Application of I2 and B2 attained the highest values of WUE, namely 3.29 and 2.75 kg/m3 for V1 and V2, respectively averaged over seasons. The highest values of WP were also found under I2 and B2, namely 2.80 and 2.34 kg/m3. In conclusion, application of B2 could relieve the effect of water deficiency and increase both WUE and WP for both mint varieties. Keywords: Biochar particles size, spearmint (Mentha spicate), peppermint (Mentha piperita L.), water use efficiency, water productivit

Cooperation and Underlay Mode Selection in Cognitive Radio Network

In this research, we proposes a new method for cooperation and underlay mode selection in cognitive radio networks. We characterize the maximum achievable throughput of our proposed method of hybrid spectrum sharing. Hybrid spectrum sharing is assumed where the Secondary User (SU) can access the Primary User (PU) channel in two modes, underlay mode or cooperative mode with admission control. In addition to access the channel in the overlay mode, secondary user is allowed to occupy the channel currently occupied by the primary user but with small transmission power. Adding the underlay access modes attains more opportunities to the secondary user to transmit data. It is proposed that the secondary user can only exploits the underlay access when the channel of the primary user direct link is good or predicted to be in non-outage state. Therefore, the secondary user could switch between underlay spectrum sharing and cooperation with the primary user. Hybrid access is regulated through monitoring the state of the primary link. By observing the simulation results, the proposed model attains noticeable improvement in the system performance in terms of maximum secondary user throughput than the conventional cooperation and non-cooperation schemes

A simplified analytical approach for optimal planning of distributed generation in electrical distribution networks

DG-integrated distribution system planning is an imperative issue since the installing of distributed generations (DGs) has many effects on the network operation characteristics, which might cause significant impacts on the system performance. One of the most important characteristics that mostly varies because of the installation of DG units is the power losses. The parameters affecting the value of the power losses are number, location, capacity, and power factor of the DG units. In this paper, a new analytical approach is proposed for optimally installing DGs to minimize power loss in distribution networks. Different parameters of DG are considered and evaluated in order to achieve a high loss reduction in the electrical distribution networks. The algorithm of the proposed approach has been implemented using MATLAB software and has been tested and investigated on 12-bus, 33-bus, and 69-bus IEEE distribution test systems. The results show that the proposed approach can provide an accurate solution via simple algorithm without using exhaustive process of power flow computations