Terrestrial invasive alien weed plants are known to infest cultivated land, potentially releasing allelochemicals into the rhizosphere during decomposition, negatively impacting crop growth. This study aimed to evaluate: (1) the allelopathic activity of five invasive weed species (Ageratum conyzoides, Bidens pilosa, Cecropia peltata, Tithonia diversifolia, and Chromolaena odorata) on Lactuca sativa and Phaseolus vulgaris growth;and (2) the effects of A. conyzoides rhizospheric soil on P. vulgaris seed germination. Bioassays of aqueous and leachate extracts were prepared from fresh leaves of the invasive species at concentrations of 0%, 25%, 50%, 75%, and 100% to assess allelopathic effects on L. sativa and P. vulgaris seed germination. Additionally, rhizospheric soil from A. conyzoides stands was collected, processed, and applied at varied weights (0.5 - 7 kg) to P. vulgaris seeds, with germination observed over nine days. Polynomial regression analysis was applied to model the data. High-concentration extracts (75% and 100%) significantly inhibited germination, root, and shoot growth in both L. sativa and P. vulgaris (P 2 − 80.294922x3 + 41.541115x4 − 11.747532x5 + 1.8501702x6 − 0.1519795x7 + 0.0050631x8. Allelopathic effects were concentration-dependent, with roots more sensitive than shoots to the invasive extracts. L. sativa was the most susceptible, while P. vulgaris showed greater tolerance. Modelling the allelopathic impact of A. conyzoides rhizospheric soil offers valuable insight into the allelochemical dosage necessary to affect seed germination, informing potential agricultural management strategies for invasive plant control.
Lawrence Monh NdamFotso Ornella ToumguemVictor Nzengong JuruDavid Tavi AgborRita Mungfu NjilarBeatrice Ambo Fonge
Coriolis effects,encompassing the dilative,compressive,and deflective manifestations,constitute pivotal considerations in the centrifugal modelling of high-speed granular run-out processes.Notably,under the deflective Coriolis condition,the velocity component parallel to the rotational axis exerts no influence on the magnitude of Coriolis acceleration.This circumstance implies a potential mitigation of the Coriolis force's deflective impact.Regrettably,extant investigations predominantly emphasize the dilative and compressive Coriolis effects,largely neglecting the pragmatic import of the deflective Coriolis condition.In pursuit of this gap,a series of discrete element method(DEM)simulations have been conducted to scrutinize the feasibility of centrifugal modelling for dry granular run-out processes under deflective Coriolis conditions.The findings concerning the deflective Coriolis effect reveal a consistent rise in the run-out distance by 2%–16%,a modest increase in bulk flow velocity of under 4%,and a slight elevation in average flow depth by no more than 25%.These alterations display smaller dependence on the specific testing conditions due to the granular flow undergoing dual deflections in opposing directions.This underscores the significance and utility of the deflective Coriolis condition.Notably,the anticipated reduction in error in predicting the final run-out distance is substantial,potentially reaching a 150%improvement compared to predictions made under the dilative and compressive Coriolis conditions.Therefore,the deflective Coriolis condition is advised when the final run-out distance of the granular flow is the main concern.To mitigate the impact of Coriolis acceleration,a greater initial height of the granular column is recommended,with a height/width ratio exceeding 1,as the basal friction of the granular material plays a crucial role in mitigating the deflective Coriolis effect.For more transverse-uniform flow properties,the width of the granular column should be as large as possible.
Road traffic flow forecasting provides critical information for the operational management of road mobility challenges, and models are used to generate the forecast. This paper uses a random process to present a novel traffic modelling framework for aggregate traffic on urban roads. The main idea is that road traffic flow is random, even for the recurrent flow, such as rush hour traffic, which is predisposed to congestion. Therefore, the structure of the aggregate traffic flow model for urban roads should correlate well with the essential variables of the observed random dynamics of the traffic flow phenomena. The novelty of this paper is the developed framework, based on the Poisson process, the kinematics of urban road traffic flow, and the intermediate modelling approach, which were combined to formulate the model. Empirical data from an urban road in Ghana was used to explore the model’s fidelity. The results show that the distribution from the model correlates well with that of the empirical traffic, providing a strong validation of the new framework and instilling confidence in its potential for significantly improved forecasts and, hence, a more hopeful outlook for real-world traffic management.
State perception of long-span 10 kV cable lines is one of the critical issues in building intelligent distribution networks.Digital twin(DT),which can map the physical status of equipment in real-time,has received extensive attention.However,traditional modelling methods cannot meet the requirement of long-span complex DT's real-time computation and scalability.In order to reduce the modelling cost and improve the calculation speed,a modular DT modelling method for cable lines based on real-time temperature field inversion is proposed.The authors develop a modular reduced-order modelling method that applies to long-span 10 kV cable lines.Combined with the temperature field inversion,a DT inversion algorithm is proposed to evaluate the transient temperature field and contact resistance inside cable lines,which has been used to evaluate the emergency load capacity.Finally,temperature rise tests verified the DT inversion algo-rithm's correctness.The operating status of cable lines was evaluated through the modular DT,and the emergency time and emergency ampacity were calculated.The result shows that the new method meets the real-time and high-precision requirements of DT calculation in actual operation scenarios.It can be easily extended to cable lines of different voltage levels.
