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Forest structure and woody plant species composition after a wildfire in beech forests in the north of Iran

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Journal of Forestry Research 2013年第2期24卷 255-262页

作者： Mohammad Naghi adel hassan Pourbabaei ali Omidi Daniel C Dey Facultad de Department of Forestry Natural Resources Faculty University of Guilan Department of Forestry Natural Resources Office USDA Forest Service Northern Research Station 202 Natural Resources Building

Beech （Fagus orientalis Lipsky） forest covers about 565,000 ha of land in Guilan province, north of Iran and forms a major carbon pool. It is an important economic, soil protection and recreation resource. We studied long-term effects of fire on the structure and composition 37 years after fire occurrence in these forests. To do this research, we selected 85 ha burned and 85 ha unburned beech forests）. The results indicated that the fire had not changed the overall uneven-aged structure, but it changed forest composition from pure stands to mixed stands that now include species such as Carpinus betulus, Acer cappadocicum and Alnus subcordata. The density of trees and regeneration was significantly increased, while the density of shrubs significantly decreased. The main reasons for increased tree regeneration were attributed to （1） reduction of litter depth, and （2） increase in available light from opening of the canopy and reduction in shrub competition. It is apparent that the forest is on a path to return to its natural state before the fire after 37 years.

关键词： fire structure composition regeneration beech forest Guilan Province

A Stochastic Flight Problem Simulation to Minimize Cost of Refuelling

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Computers, Materials & Continua 2021年第10期69卷 849-871页

作者： Said ali hassan Khalid Alnowibet Miral H.Khodeir Prachi Agrawal adel F.Alrasheedi ali Wagdy Mohamed Department of Operations Research and Decision Support Faculty of Computers and Artificial IntelligenceCairo UniversityGiza12613Egypt Department of Statistics and Operations Research College of ScienceKing Saud UniversityRiyadh11451Kingdom of Saudi Arabia Department of Mathematics and Scientific Computing National Institute of Technology HamirpurHimachal Pradesh177005India Department of Operations Research Faculty of Graduate Studies for Statistical ResearchCairo UniversityGiza12613Egypt Wireless Intelligent Networks Center(WINC) School of Engineering and Applied SciencesNile UniversityGizaEgypt

Commercial airline companies are continuously seeking to implement strategies for minimizing costs of fuel for their flight routes as acquiring jet fuel represents a significant part of operating and managing expenses for airline activities.A nonlinear mixed binary mathematical programming model for the airline fuel task is presented to minimize the total cost of refueling in an entire flight route *** model is enhanced to include possible discounts in fuel prices,which are performed by adding dummy variables and some restrictive constraints,or by fitting a suitable distribution function that relates prices to purchased *** obtained fuel plan explains exactly the amounts of fuel in gallons to be purchased from each airport considering tankering strategy while minimizing the pertinent cost of the whole flight *** relation between the amount of extra burnt fuel taken through tinkering strategy and the total flight time is also considered.A case study is introduced for a certain flight rotation in domestic US air transport *** mathematical model including stepped discounted fuel prices is *** problem has a stochastic nature as the total flight time is a random variable,the stochastic nature of the problem is realistic and more appropriate than the deterministic *** stochastic style of the problem is simulated by introducing a suitable probability distribution for the flight time duration and generating enough number of runs to mimic the probabilistic real *** similar real application problems are modelled as nonlinear mixed binary ones that are difficult to handle by exact ***,metaheuristic approaches are widely used in treating such different optimization *** this paper,a gaining sharing knowledge-based procedure is used to handle the mathematical *** algorithm basically based on the process of gaining and sharing knowledge throughout the human *** generated simulation runs of

关键词： Stochastic flight problem cost of refuelling ferrying strategy tankering discounted prices simulation procedure nonlinear mixed binary model metaheuristic algorithm gaining-sharing knowledge-based algorithm

Improved-Equalized Cluster Head Election Routing Protocol for Wireless Sensor Networks

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Computer Systems Science & Engineering 2023年第1期44卷 845-858页

作者： Muhammad Shahzeb ali ali Alqahtani Ansar Munir Shah adel Rajab Mahmood Ul hassan Asadullah Shaikh Khairan Rajab Basit Shahzad Department of Computer Science Institute of Southern PunjabMultan5932Pakistan College of Computer Science and Information Systems Najran UniversityNajran61441Saudi Arabia Department of Computer Skills Deanship of Preparatory YearNajran UniversityNajran61441Saudi Arabia Department of Engineering National University of Modern LanguagesIslamabad44000Pakistan

Throughout the use of the small battery-operated sensor nodes encou-rage us to develop an energy-efficient routing protocol for wireless sensor networks(WSNs).The development of an energy-efficient routing protocol is a mainly adopted technique to enhance the lifetime of *** routing protocols are available,but the issue is still *** is one of the most important techniques in the existing routing *** the clustering-based model,the important thing is the selection of the cluster *** this paper,we have proposed a scheme that uses the bubble sort algorithm for cluster head selection by considering the remaining energy and the distance of the nodes in each ***,the bubble sort algorithm chose the two nodes with the maximum remaining energy in the cluster and chose a cluster head with a small *** proposed scheme performs hierarchal routing and direct routing with some energy *** simulation will be performed in MATLAB to justify its performance and results and compared with the ECHERP model to justify its ***,the simulations will be performed in two scenarios,gate-way-based and without gateway to achieve more energy-efficient results.

关键词： Bubble sort algorithm gateway energy thresholds wireless sensor networks

Long-term effect of fire on herbaceous species diversity in oriental beech (Fagus orientalis Lipsky) forests in northern Iran

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Forestry Studies in China 2012年第4期14卷 260-267页

作者： Mohammad Naghi adel hassan POURBABAEI ali OMIDI David POTHIER Department of Forestry Natural Resources FacultyUniversity of Guilan Department of Forestry Natural Resources Office Centre d'étude de la forêt (CEF) et Département des sciences du bois et de la forêt Pavillon Abitibi-Price2405 rue de la TerrasseUniversité Laval

We studied the long-term impacts of natural burning on herbaceous species diversity 37 years after a fire occurred in the Roudbar forests of Guilan Province, northern Iran. Numerous studies have examined short-term changes in understory vegetation following wildfire; however, very few long-term studies are available or changes inferred from retrospective studies based on chro- nosequences. For this study, 170 ha of forest （85 ha, burned areas; 85 ha, unburned areas） were surveyed. Because the 1000 m2 plots were too large for detailed measurements of herbaceous species, we determined a sub-sample size according to the Whittaker＇s nested plot sampling protocol and minimal areas method. Hence, sub-plots of 32 m2 were used for herbaceous species measurements, which consisted of percent cover of each species based on the Domin criterion. We measured plant diversity （Shannon-Wiener index）, spe- cies richness （Margalef＇s index）, and evenness （Smith-Wilson index）. Mean percent cover, together with diversity, richness and even- ness, increased markedly in burned areas compared to unburned controls. This suggests that the biodiversity of these forests could be restored within 37 years after fire. However, the abundance of invasive species such as Rubus fruticosus and Bromus benekenii increased significantly in burned areas, but these could be controlled by relevant silvicultural operations.

关键词： fire diversity richness evenness beech forest northern Iran

ON THE STABILITY OF A FUNCTIONALLY GRADED RECTANGULAR MICRO-PLATE SUBJECTED TO HYDROSTATIC AND NONLINEAR ELECTROSTATIC PRESSURES

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Acta Mechanica Solida Sinica 2013年第2期26卷 205-220页

作者： adel Nabian Ghader Rezazadeh Morteza Almassi ali-Mohammad Borgheei Department of Agricultural Machinery Engineering Science and Research BranchIslamic Azad UniversityTehranIran Department of Mechanical Engineering Urmia UniversityUrmiaIran

This article studies the stability of a functionally graded clamped-clamped micro- plate subjected to hydrostatic and electrostatic pressures. Equilibrium positions of the micro-plate are determined and shown in the state control space. To study the stability of the equilibrium positions, the motion trajectories are given for different initial conditions in the phase plane. Effects of the electrostatic and hydrostatic pressure changes on the deflection and stability of the micro-plate for some sample value of k are studied and values of the applied voltage and hydrostatic pressure leading system to unstable conditions by undergoing a saddle node and homoclinic bifurcations are determined.

关键词： MEMS FGM stability micro-plate electrostatic hydrostatic pressure

Computational investigation of hydraulic performance variation with geometry in gabion stepped spillways

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Water Science and Engineering 2019年第1期12卷 62-72页

作者： Dominic E.Reeve ali adel Zuhaira Harshinie Karunarathna College of Engineering Swansea University

Over recent years, there has been a clear increase in the frequency of reported flooding events around the world. Gabion structures offer one means of flood mitigation in dam spillways. These types of structures provide an additional challenge to the computational modeller in that flow through the porous gabions must be simulated. We have used a computational model to investigate the flow over gabion stepped spillways. The model was first validated against published experimental results. Then, gabion stepped spillways with four different step geometries were tested under the same conditions in order to facilitate inter-comparisons and to choose the best option in terms of energy dissipation. The results show that normal gabion steps can dissipate more energy than overlap, inclined, and pooled steps. An intensive set of tests with varying slope, stone size, and porosity were undertaken. The location of the inception point and the water depth at this point obtained from this study were compared with those from existing formulae. Two new empirical equations have been derived, on the basis of a regression analysis, to provide improved results for gabion stepped spillways.

关键词： Computational modelling Energy dissipation Gabion stepped spillways Inception point location Skimming flow

Robust correlation to predict dew point pressure of gas condensate reservoirs

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Petroleum 2017年第3期3卷 340-347页

作者： Mohammad ali Ahmadi adel Elsharkawy Department of Petroleum Engineering Ahwaz Faculty of Petroleum EngineeringPetroleum University of TechnologyAhwazIran Department of Petroleum Engineering College of Engineering&PetroleumKuwait UniversityKuwait

When the bottom-hole flowing pressure in a gas condensate reservoir drops below the dew point pressure,liquid starts to build up around the well bore resulting in gas productivity *** this reason it is important to be able to accurately either measure or estimate the dew point *** condensate formed in the reservoir will not flow until its saturation reaches the critical saturation and in many cases it might not be entirely *** order to maximize gas production and condensate recovery,the reservoir pressure must be maintained close to the dew point *** attempts have been made to predict the dew point pressure in case the gas sample becomes unavailable or measured value is ***,most of these attempts have minor success rates and are based on limited *** this paper we present a robust,cheap,and easy model for predicting the dew point pressure for gas condensate *** new model is an intelligent based model called“Gene Expression Programming”that is carried out to generate a precise and accurate correlation to estimate the dew point pressure in condensate gas *** new model has been trained and tested using a large data bank collected for the *** of the suggested correlation has been compared to published *** validity of this model has also been compared to experimental data and other published correlations.

关键词： Dew point pressure Gene Expression Programming Condensate gas Modeling

A Solvation Model for Performance Enhancement of Dye-Sensitized Solar Cells

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Fluid Dynamics & Materials Processing 2022年第6期18卷 1569-1579页

作者： adel Daoud ali Cheknane Jean Michel Nunzi Afak Meftah Laboratoire des Matériaux Semi-Conducteurs et Métalliques(LMSM) Universitéde BiskraBiskraAlgeria Laboratoire des Semi-Conducteurs et Matériaux Fonctionnels(LSMF) UniversitéAmar Telidji de LaghouatLaghouatAlgérie Department of Chemistry Queen’s UniversityKingstonCanada Department of Engineering Physics and Astronomy Queen’s UniversityKingstonCanada

A solubility model for Merocyanine-540 dye together with the interface’s electron transfer kinetics of MC-540/TiO2 has been investigated(Merocyanine 540-based dye has been used effectively in dye-sensitized solar cells).The highest absorption peaks were recorded at 489 nm and 493 nm in Water and Ethanol solvent,*** vacuum phase which yielded 495 nm(associated with a modest electron injection-free energy value(Ginj)of−2.34 eV for both Water and Ethanol solvents).The time-dependent density functional theory(TD-DFT)method approach has been applied in this ***,the electronic structure and simulated UV-Vis spectra of the dye in different solvents have been determined,and the alignment with the solar spectrum has been discussed to a certain *** energy level diagrams and electron density of the primary molecular orbitals are shown,and the major issues that have an impact on our new interface’s performance are *** is concluded that the proposed Solvation Model(SM)can improve the performance of Dye-Sensitized Solar Cells.

关键词： Mc-540-based dye DFT method electron injection n-DSSCs

A numerical study of anti-vortex film-cooling holes designs in a 1-1/2 turbine stage using LES

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Propulsion and Power Research 2019年第4期8卷 275-299页

作者： Nabeel Al-Zurfi ali Turan adel Nasser Ahmed Alhusseny Department of Mechanical Engineering Faculty of EngineeringUniversity of KufaNajafIraq Visiting Researcher Department of MechanicalAerospace and Civil EngineeringSchool of EngineeringFaculty of Science and EngineeringThe University of ManchesterManchesterM139PLUK Department of Mechanical Aerospace and Civil EngineeringSchool of EngineeringFaculty of Science and EngineeringThe University of ManchesterManchesterM139PLUK

The primary focus of the present study is to investigate the impact of anti-vortex holes design on the film-cooling performance in a film-cooled rotor blade model using the large eddy simulation method(LES).One row of the film holes was positioned on the pressure surface of the rotor *** row had three cylindrical holes(the main hole in the present study)with a diameter(D)of 4 mm and a tangential injection angle of 28 *** main hole supplemented with the addition of two symmetrical side holes(anti-vortex holes),which branch out from the same main *** positions for the anti-vortex side holes were considered;namely:upstream to the outlet of the main hole;in line with the main hole;and downstream of the main *** Reynolds number was fixed at Re Z 1.92105 and the speed of the rotor blade was taken to be 1800 *** blowing ratio varied from 1.0 to 5.0 and the density ratio of coolant to mainstream was *** to the base hole,the film cooling performance of the all anti-vortex cases showed obvious improvement at all blowing *** middle stream side holes and downstream side holes each demonstrated good film cooling performance at all blowing ratios,while the upstream side holes perform well only at a lower blowing *** presence of side holes can restrain the CRVP(counter rotating vortex pairs)intensity of the main hole and reduce the coolant lift-off,improving the film coverage and film cooling *** downstream side holes can perform better in reducing the CRVP intensity.

关键词： Rotor blade Large eddy simulation Film-cooling effectiveness Turbulence Rotation Anti-vortex hole