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Master equation and runaway speed of the Francis turbine

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Journal of Hydrodynamics 2018年第2期30卷 203-217页

作者： Zh.Zhang free researcher Zurich Switzerland

The master equation of the Francis turbine is derived based on the combination of the angular momentum（Euler） and the energy laws. It relates the geometrical design of the impeller and the regulation settings（guide vane angle and rotational speed） to the discharge and the power output. The master equation, thus, enables the complete characteristics of a given Francis turbine to be easily computed. While applying the energy law, both the shock loss at the impeller inlet and the swirling loss at the impeller exit are taken into account. These are main losses which occur at both the partial load and the overloads and, thus, dominantly influence the characteristics of the Francis turbine. They also totally govern the discharge of the water through the impeller when the impeller is found in the standstill. The computations have been performed for the discharge, the hydraulic torque and the hydraulic efficiency. They were also compared with the available measurements on a model turbine. Excellent agreement has been achieved. The computations also enable the runaway speed of the Francis turbine and the related discharge to be determined as a function of the setting angle of the guide vanes.

关键词： Francis turbine master equation runaway speed hydraulic efficiency shock loss swirling loss streamline similarity method

Explicit Estimates for Solutions of Nonlinear Radiation-type Problems

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Acta Mathematica Sinica,English Series 2015年第7期31卷 1123-1140页

作者： Luisa CONSIGLIERI Independent researcher Professor

We establish the existence of weak solutions of a nonlinear radiation-type boundary value problem for elliptic equation on divergence form with discontinuous leading coefficient. Quantitative estimates play a crucial role on the real applications. Our objective is the derivation of explicit expres- sions of the involved constants in the quantitative estimates, the so-called absolute or universal bounds. The dependence on the leading coefficient and on the size of the spatial domain is precise. This work shows that the expressions of those constants are not so elegant as we might expect.

关键词： Elliptic equation estimate regularity radiation-type boundary condition

freeform path fitting for the minimisation of the number of transitions between headland path and interior lanes within agricultural fields

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Artificial Intelligence in Agriculture 2021年第1期5卷 233-239页

作者： Mogens Graf Plessen MGP is an independent researcher

Within the context of in-field path planning this paper discusses freeformpath fitting for theminimisation of the number of transitions between headland path and interior laneswithin agricultural *** topic ismotivated by two *** to crossings of tyre traces such transitions in practice often cause an increase of compacted ***,for very tight angles between headland path and interior lanes undesired hairpin turnsmay becomenecessary due to the limited agility of in-field operating *** the number of interior lanes both detrimental effects can be *** potential of minimising the number of interior lanes by freeform path fitting is evaluated on 10 non-convex real-world fields including obstacle areas,and compared to the more common technique of fitting straight interior lanes.

关键词： In-field path planning freeform path fitting Agricultural logistics

Solutions in the Discrete Fractional Forms of Two Differential Equations with Singular Points

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Acta Mathematicae Applicatae Sinica 2020年第4期36卷 975-981页

作者： Okkes OZTURK Independent researcher Islahiye 27800Turkey

In present note,we apply the Leibniz formula with the nabla operator in discrete fractional calculus(DFC)due to obtain the discrete fractional solutions of a class of associated Bessel equations(ABEs)and a class of associated Legendre equations(ALEs),***,we exhibit a new solution method for such second order linear ordinary differential equations with singular points.

关键词： fractional calculus discrete fractional calculus discrete fractional solutions nabla operator

Numerical three-dimensional modeling of earthen dam piping failure

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Water Science and Engineering 2024年第1期17卷 72-82页

作者： Zhengang Wang Independent researcher HerndonVA 20171USA

A physically-based numerical three-dimensional earthen dam piping failure model is developed for homogeneous and zoned soil *** model is an erosion model,coupled with force/moment equilibrium *** flow and two-dimensional(2D)shallow water equations(SWE)are solved to simulate dam break flows at different breaching *** rates of different soils with different construction compaction efforts are calculated using corresponding erosion *** dam's real shape,soil properties,and surrounding area are *** outer 2D-SWE grids are used to control upstream and downstream hydraulic conditions and control the boundary conditions of orifice flow,and inner 2D-SWE flow is used to scour soil and perform force/moment equilibrium *** model is validated using the European Commission IMPACT(Investigation of Extreme Flood Processes and Uncertainty)Test#5 in Norway,Teton Dam failure in Idaho,USA,and Quail Creek Dike failure in Utah,*** calculated peak outflows are within 10%errors of observed *** results show that,for a V-shaped dam like Teton Dam,a piping breach location at the abutment tends to result in a smaller peak breach outflow than the piping breach location at the dam's center;and if Teton Dam had broken from its center for internal erosion,a peak outflow of 117851 m'/s,which is 81%larger than the peak outflow of 65120 m3/s released from its right abutment,would have been released from Teton Dam.A lower piping inlet elevation tends to cause a faster/earlier piping breach than a higher piping inlet elevation.

关键词： 3D dam breach model 2D shallow water equations 3D slope stability analysis Piping failure Teton Dam Quail Creek Dike

Participative Research:What Are the Advantages of Thinking about Research on the Cancer Care Pathway?Views of Two Patient Co-researchers

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Psycho-Oncologie 2023年第3期17卷 195-199页

作者： Sylvie Faiderbe Nadège Berlioz Patient-researcher Regnéville-Sur-Mer50590France Patient-researcher Paris75000France

Two patients relate their experience as co-researchers in a research project in the human and social *** the genesis of the research project to the results,they detail their participation in each stage of this project alongside care professionals and researchers:their difficulties,their contributions,their pleasure,and speculations on the conditions for improving this type of active collaboration in a participative research project.

关键词： Participative research patient researcher patient expert patient partner care pathway

Eco-physiological studies on desert plants: germination of Halothamnus iraqensis Botsch. seeds under different conditions

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Journal of Arid Land 2019年第1期11卷 75-85页

作者： Arvind BHATT Narayana R BHAT Valentina MURRU ANDrea SANTO Kuwait Institute for Scientific Research University of Cagliari Independent researcher

With the aim to investigate if the halophyte Halothamnus iraqensis Botsch. can be suitable for re-vegetation and remediation of salt-affected lands, this study evaluated(1) the effects of photoperiod, thermoperiod, storage period and wings' presence on its seed germination, and(2) the ability of its seeds to have successful germination recovery after salt stress. Germination tests in different photoperiods(12 h light/12 h darkness and total darkness) and thermoperiods(15℃/20℃ and 20℃/25℃) were conducted for seeds collected in 2012, 2013, 2014, 2015 and 2016. The seeds collected in 2016 were sown under different salinity levels(0, 100, 200, 400 and 600 m M Na Cl) to assess the salinity tolerance during the germination. Wings' presence highly inhibited seed germination of this species in both photoperiods and thermoperiods under all salinity level treatments. In addition, the germination recovery occurred well when seeds were deprived of their wings. The photoperiod of 12 h light/12 h darkness and the thermoperiod of 15℃/20℃ were the best conditions for seed germination. Germination percentages of H. iraqensis seeds decreased with the increasing storage duration, especially after three years of the collection. In addition, H. iraqensis seeds were able to germinate under different salinity levels, and their germination percentages decreased with increasing salinity levels. H. iraqensis seeds have the ability to recover their germination after alleviating the salt stress, irrespective of photoperiod, highlighting the halophilous character of this species.

关键词： wings’ presence storage period photoperiod thermoperiod salt stress Halothamnus iraqensis Botsch

Nanotechnological approaches for counteracting multidrug resistance in cancer

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Cancer Drug Resistance 2020年第4期3卷 1003-1020页

作者： Chiara Martinelli Marco Biglietti Independent researcher Como 22100Italy Independent researcher Milan 20148Italy

Every year,cancer accounts for a vast portion of deaths *** clinical protocols are based on chemotherapy,which,however,is not tumor-selective and produces a series of unbearable side effects in healthy *** a consequence,multidrug resistance(MDR)can arise causing metastatic progression and disease *** therapy has demonstrated limited responses in the treatment of MDR,mainly due to the different pharmacokinetic properties of administered drugs and to tumor heterogeneity,challenges that still need to be solved in a significant percentage of cancer *** this perspective,we briefly discuss the most relevant MDR mechanisms leading to therapy failure and we report the most advanced strategies adopted in the nanomedicine field for the design and evaluation of ad hoc *** present some emerging classes of nanocarriers developed to reverse MDR and discuss recent progress evidencing their limits and promises.

关键词： Multidrug resistance cancer nanotechnology nanomedicine nanocarriers targeted delivery

Preserving Privacy of Software-Defined Networking Policies by Secure Multi-Party Computation

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Journal of Computer Science & Technology 2020年第4期35卷 863-874页

作者： Maryam Zarezadeh Hamid Mala Homa Khajeh Faculty of Computer Engineering University of IsfahanIsfahan ***Iran Independent researcher Isfahan ***Iran

In software-defined networking(SDN),controllers are sinks of information such as network topology collected from *** often like to protect their internal network topology and keep their network policies *** borrow techniques from secure multi-party computation(SMC)to preserve the privacy of policies of SDN controllers about status of *** the other hand,the number of controllers is one of the most important concerns in scalability of SMC application in *** address this issue,we formulate an optimization problem to minimize the number of SDN controllers while considering their reliability in SMC *** use Non-Dominated Sorting Genetic Algorithm II(NSGA-II)to determine the optimal number of controllers,and simulate SMC for typical SDNs with this number of *** results show that applying the SMC technique to preserve the privacy of organization policies causes only a little delay in SDNs,which is completely justifiable by the privacy obtained.

关键词： software-defined networking (SDN) privacy secure multi-party computation (SMC) structure function multi-objective optimization