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This paper models and analyses the dynamic response of a synchronous generator driven off-grid micro hydro power system using Simulink tool of MATLAB software. The results are assessed from various perspectives including regulation through no load to full load and overload scenarios under normal and abnormal operating conditions. The investigation under the normal conditions of no load, linearly changing load and full load divulges that the system operates in a satisfactory manner as generator voltage and frequency remain approximately constant at 1 pu. However, at full load generator voltage and frequency drop 3% and 0.5% respectively from its nominal values but remain within prescribed standard IEC limits. The results also expose that the abnormal conditions produced by abrupt changes in load, system faults and severe overload, cause the unwonted variations in the magnitude of generator parameters. Moreover, the study reveals that the system stability significantly enhances when the system is run at full load because the regulation time to fix the variations in the generator parameters; except input mechanical power; decreases, e.g. from 4.1 sec to 0.8 sec for generator voltage, with the increase in the loading from quarter to full load respectively at unity power factor. Further, it is also observed that the regulation time rises, e.g. from 0.8 sec to 1.3 sec for generator voltage, with the reduction in load power factor from unity to 0.8, respectively. Thus, proper protection, to cater for increased fault current at full load and power factor correction must be provided to improve the system stability and protection. Furthermore, it is also concluded that the over loading in any case should be strongly avoided in this type of system and it should never be allowed to exceed 20% of the full load value to avoid system failure

Grapevine is one of the most economically important fruit crops cultivated worldwide. However, grapevine is highly susceptible to virus infections and exposed to the most diverse forms of viral diseases compared to other fruit crops, and virus-induced incompatibility affects plant growth to different degrees ranging from decline to death. The influence of virus-induced incompatibility could be mitigated to an acceptable level by using appropriate rootstocks. However, the viral tolerance of various grapevine rootstocks with diverse genetic backgrounds remains unclear, along with the identification of the specific viral tolerance factors. In this study, the viral tolerance of 21 grapevine rootstocks was evaluated in a green grafting system. Cabernet Franc varieties infected with a single virus [grapevine leafroll associated virus-1 (GLRaV-1)], a co-infection of two viruses (GLRaV-1 plus grapevine virus A—GVA), and no infection were used as the scions, respectively. The vegetative growth and photosynthetic function of the grafts were analyzed 4 months after grafting. The results indicated that some rootstocks could alleviate the influence of the virus infection, with vegetative growth and photosynthetic function sustained at a normal level, whereas other rootstocks were susceptible to the virus infection, resulting in a decline in the growth and photosynthetic function of the grafts. Our research provides evidence for the existence and diversity of viral tolerance among grapevine rootstocks, offering important information for appropriate rootstock selection in the establishment of new vineyards and in the breeding of grapevine rootstocks with enhanced viral tolerance. [ABSTRACT FROM AUTHOR]

Waterproof and breathable membranes (WBMs) have gained significant attention as versatile functional materials. However, developing a fluorine-free WBM with waterproofness, breathability, and thermo-regulation performance using a straightforward strategy remains a significant challenge. Direct electrospinning was used to fabricate fluorine-free silicon-based polyurethane/graphene quantum dots/stearic acid (SiPU/GQDs/SA) nanofiber membranes. SA, a phase change material with low surface energy, imparts the nanofiber membrane enhanced hydrophobicity and thermo-regulation performance. Graphene quantum dots (GQDs) further increased the phase transition enthalpy of the SiPU/GQDs/SA nanofiber membranes. The resulting SiPU/GQDs/SA-20 WBM demonstrates exceptional water resistance (hydrostatic pressure, 67.8 kPa), good breathability (water vapor transmission (WVT) rate, 5166 g m–2 d–1), remarkable tensile strength (tensile stress, 5.95 MPa), stable thermo-regulation performance (phase transition latent heat, 29.57 J/g), and outstanding anticounterfeiting performance. This fluorine-free, highly protective, and comfortable WBM offers extensive application prospects in fields such as outdoor textiles and electronic devices. [ABSTRACT FROM AUTHOR]