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Zinc and cadmium accumulation in cabbage aphid （Brevicoryne brassicae） host plants and developmental instability

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Insect Science 2009年第1期16卷 65-71页

作者： Gazi Gorur Department of Biology Science and Arts Faculty Nigde University 51100 Nigde Turkey

Developmental instability in morphological characters can occur during individual development due to various environmental stresses. Fluctuating asymmetry （FA） is often used as a measurement of developmental instability, but within-environment variation （CVo） is also considered an indicator of developmental instability. Cabbage aphid （Brevicoryne brassicae） populations were reared on zinc- （Zn） or cadmium- （Cd） contaminated cabbage and radish plants. Developmental instability indicators were measured and their relations with fitness were explored. Results revealed that cabbage aphids exposed to Cd and Zn displayed considerable developmental instability, particularly fluctuating asymmetry. Differences in developmental instability between the two metals were also detected, as well as differences between the two developmental instability measurements. For almost all measured traits, FA was greater on Cd- and Zn-contaminated compared to non-contaminated host plants. In contrast, CVo of some traits was greater on non-contaminated host plants, yet for other traits CVo was greater on contaminated host plants. There were also non-significant inverse relationships between FA and fitness of cabbage aphid populations. Due to weak correlations between FA and different patterns of two developmental instability measurements, this study does not support the hypothesis that developmental instability is a useful bioindicator of environmental quality.

关键词： aphid fluctuating asymmetry heavy metal

Effect of Plastic Deformation on Magnetic Properties of Fe-40%Ni-2%Mn Austenitic Alloy

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Journal of Iron and Steel Research International 2007年第4期14卷 56-60页

作者： Selva Büyükakka■ H Aktas S Akturk Physics Department Nigde UniversityNigde 51100NigdeTurkey Physics Department Kirikkale UniversityYahsihan 71450KirikkaleTurkey

The effects of plastic deformation on the magnetic properties of austenite structure in an Fe-40% Ni-2 % Mn alloy is investigated by using Mossbauer spectroscopy and Differential Scanning Calorimetry （DSC） techniques The morphology of the alloy has been obtained by using Scanning Electron Microscopy （SEM）. The magnetic behaviour of austenite state is ferromagnetic. After plastic deformation, a mixed magnetic structure including both paramagnet- ic and ferromagnetic states has been obtained at the room temperature. The volume fraction changes, the effective hyperfine fields of the ferromagnetic austenite phase and isomery shift values have also been determined by Mossbauer spectroscopy. The Curie point （Tc） and the Neel temperature （TN） have been investigated by means of DSC system for non-deformed and deformed Fe-Ni-Mn alloy. The plastic deformation of the alloy reduces the TN and enhances the paramagnetic character of austenitic Fe-Ni-Mn alloy.

关键词： Mossbauer spectroscopy differential scanning calorimetry (DSC) scanning electron microscopy (SEM) plastic deformation magnetically ordered material ferromagnetic austenite

Effect of the Velocity-Dependent Potentials on the Bound State Energy Eigenvalues

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Chinese Physics Letters 2011年第4期28卷 28-31页

作者： O.Bayrak A.Soylu I.Boztosun Department of Physics Akdeniz UniversityAntalya 07058Turkey Department of Physics Nigde UniversityNigde 51240Turkey

We investigate the effect of isotropic velocity-dependent potentials on the bound state energy eigenvalues for the first time for any quantum states of the Coulomb and harmonic oscillator potentials within the framework of the asymptotic iteration *** the velocity-dependent term is selected as a constant parameter𝜌0,we present that the energy eigenvalues can be obtained analytically for both Coulomb and harmonic oscillator ***,when the velocity-dependent term is considered as a harmonic oscillator type𝜌ρor^(2)𝑟,taking the velocity-dependent term as a perturbation,we present how to obtain the energy eigenvalues of the Coulomb and harmonic oscillator potentials for any n and e quantum states by using perturbation expansion and numerical calculations in the asymptotic iteration method procedure.

关键词： method harmonic oscillator

Mechanical, electrical, and thermal properties of the directionally solidified Bi–Zn–Al ternary eutectic alloy

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International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 999-1008页

作者： M.Sahin E.adrli Department of Electronics and Automation Technical Vocational School of Sciences Nigde University Department of Physics Faculty of Arts and Sciences Nigde University

A Bi-2.0Zn-0.2A1 （wt%） ternary eutectic alloy was prepared using a vacuum melting furnace and a casting furnace. The samples were directionally solidified upwards at a constant growth rate （V= 18.4 μm/s） under different temperature gradients （G = 1.15-3.44 K/mm） and at a constant temperature gradient （G = 2.66 K/mm） under different growth rates （V= 8.3-500 μm/s） in a Bridgman-type directional so- lidification furnace. The dependence ofmicrostructure parameter （2） on the solidification parameters （G and V） and that of the microhardness （Hv） on the microstructure and solidification parameters were investigated. The resistivity （ρ） measurements of the studied alloy were per- formed using the standard four-point-probe method, and the temperature coefficient of resistivity （α） was calculated from the ρ-Tcurve. The enthalpy （AH） and the specific heat （Cp） values were determined by differential scanning calorimetry analysis. In addition, the thermal conductivities of samples, obtained using the Wiedemann-Franz and Smith-Palmer equations, were compared with the experimental results. The results revealed that, the thermal conductivity values obtained using the Wiedemarm-Franz and Smith-Palmer equations for the Bi-2.0Zn-0.2Al （wt%） alloy are in the range of 5.2-6.5 W/Km and 15.2-16.4 W/Km, respectively.

关键词： ternary eutectic alloys directional solidification microhardness electrical resistivity thermal conductivity

Parameters Calibration of the Combined Hardening Rule through Inverse Analysis for Nylock Nut Folding Simulation

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Computer Modeling in Engineering & Sciences 2021年第7期128卷 87-108页

作者： Ilyas Kacar Faculty of Engineering Department of Mechatronics EngineeringNigde Omer Halisdemir UniversityNigdeTurkey

Locking nuts are widely used in industry and any defects from their manufacturing may cause loosening of the connection during their service *** this study,simulations of the folding process of a nut’s flange made from AISI 1040 steel are *** the bilinear isotropic hardening rule,Chaboche’s nonlinear kinematic hardening rule is employed with associated flow rule and Hill48 yield criterion to set a plasticity *** bilinear isotropic hardening rule’s parameters are determined by means of a monotonic tensile *** Chaboche’s parameters are determined by using a low cycle tension/compression test by applying curve fitting methods on the low cycle fatigue ***,the parameter calibrations are performed in the finite element simulations by using an optimization approach based on the inverse *** accuracy for the nut is of primary concern due to the tolerance constraints of the nut *** diameter and height measurements of the folded locking nut are compared with those obtained from the optimized *** results reveal that the folding dimensions can be predicted more accurately when the model parameters are determined by using the combined hardening *** calibrated parameters are presented for the folding and cycling deformation processes.

关键词： Optimization Chaboche kinematic hardening bilinear isotropic hardening nylock nut folding genetic algorithm

Impact of Electric Vehicle Aggregator with Communication Time Delay on Stability Regions and Stability Delay Margins in Load Frequency Control System

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Journal of Modern Power Systems and Clean Energy 2021年第3期9卷 595-601页

作者： Ausnain Naveed Sahin Sonmez Saffet Ayasun the Department of Electrical and Electronic Engineering Nigde Omer Halisdemir UniversityNigdeTurkey the Department of Electrical and Electronic Engineering Gazi UniversityAnkaraTurkey

This paper investigates the impact of electric vehicle(EV)aggregator with communication time delay on stability regions and stability delay margins of a single-area load frequency control(LFC)***,a graphical method characterizing stability boundary locus is *** a given time delay,the method computes all the stabilizing proportional-integral(PI)controller gains,which constitutes a stability region in the parameter space of PI ***,in order to complement the stability regions,a frequency-domain exact method is used to calculate stability delay margins for various values of PI controller *** qualitative impact of EV aggregator on both stability regions and stability delay margins is thoroughly analyzed and the results are authenticated by time-domain simulations and quasi-polynomial mapping-based root finder(QPmR)algorithm.

关键词： Communication time delay electric vehicle(EV)aggregator frequency regulation proportional-integral(PI)controller design stability delay margin stability region

Binding energy of the donor impurities in GaAs-Ga_(1-x)Al_xAs quantum well wires with Morse potential in the presence of electric and magnetic fields

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Chinese Physics B 2016年第10期25卷 39-44页

作者： Esra Aciksoz Orhan Bayrak Asim Soylu Department of Physics Akdeniz University Department of Physics Nigde University

The behavior of a donor in the GaAs–GaAlAs quantum well wire represented by the Morse potential is examined within the framework of the effective-mass approximation. The donor binding energies are numerically calculated for with and without the electric and magnetic fields in order to show their influence on the binding energies. Moreover, how the donor binding energies change for the constant potential parameters(De, re, and a) as well as with the different values of the electric and magnetic field strengths is determined. It is found that the donor binding energy is highly dependent on the external electric and magnetic fields as well as parameters of the Morse potential.

关键词： Morse potential electric field magnetic field the donor atom quantum well wire

Tensile and Spring-Back Behavior of DP600 Advanced High Strength Steel at Warm Temperatures

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Journal of Iron and Steel Research International 2009年第6期16卷 41-46页

作者： F Ozturk S Toros S Kilic Department of Mechanical Engineering Nigde University

In recent years, the use of advanced high strength steels in automotive industry has been increased remarkably. Among advanced high strength steels, dual phase （DP） steels have gained a great attention owing to a combination of high strength and good formability. However, high strength usually increases the spring-back behavior of the material, which creates problems for the parts during the assembly. Thus, the uniaxial tensile deformation and spring-back behaviors of DP600 advanced high strength steel were investigated in rolling （0°）, diagonal （45°） , and transverse （90°） directions in the temperature range from room temperature （RT） to 300 ℃. All tests were performed at a deformation speed of 25 mm/min. A V-shaped die （60°） was used for the spring-back measurements. The results indicated that the formability and spring-back of the material were decreased with increasing the temperatures. The material showed complex behaviors in different directions and at different temperatures.

关键词： advanced high strength steel DP600 warm forming spring-back

The Allelopathic Effects of Sunflower and Wheat Root Exudates on Sinapis arvensis and Sinapis alba

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Phyton-International Journal of Experimental Botany 2019年第4期88卷 413-423页

作者： Bengu Turkyilmaz Unal Mustafa Bayram nigdeÖmer Halisdemir university Faculty of Arts and SciencesDepartment of Biotechnology51240NigdeTurkey nigdeÖmer Halisdemir university Faculty of Arts and SciencesDepartment of Biology51240NigdeTurkey

In this study,we aimed to investigate the allelopathic effects of sunflower and wheat root exudates on the common weeds such as wild mustard and white mustard in our *** root exudates which were obtained by soaking 8 weeks old sunflower and wheat seedlings(20 or 40 seedlings)in 100 mL of distilled water for 3 days were applied to the leaves of wild mustard and white *** order to compare the allelopathic effect,the recommended dose(1 ***^(-1))and twice the recommended dose(2 ***^(-1))of Gromstor(Tribenuron-methyl),a herbicide preferred by farmers for the chemical control of these weeds was also *** allelopathy was performed for wild mustard and white mustard seedlings by the measurement of different physiological and biochemical parameters,such as chlorophyll a,chlorophyll b,total chlorophyll,carotenoid,proline,total protein amounts and superoxide dismutase enzyme *** amounts of total chl and carotenoid in wild mustard leaves decreased in all treatment groups compared to *** highest decrease in total chl(50.93%)and carotenoid(46.69%)was oberved in the treatment of 40 wheat seedlings.100 mL^(-1) distilled *** the white mustard leaves,the amount of total chl in all treatment groups except the treatment group of Gromstor 2 ***^(-1) and carotenoid in all treatment groups increased compared to the *** highest increases again were observed in 40 wheat seedlings.100 mL^(-1) distilled water *** proline amounts in wild mustard and white mustard increased in all treatment *** highest increase was observed for the treatment of 20 wheat seedlings.100 mL^(-1) distilled water in wild mustard(459.69%)and 40 sunflower seedlings.100 mL^(-1) distilled water in white mustard plant(104.70%).In superoxide dismutase enzyme activities,treatments decreased activity except treatment of 40 sunflower seedling root exudate in wild mustard,while increased activity outside commercial herbicide treatment in white *** r

关键词： Allelopathy antioxidant enzymes bioherbicide photosynthetic pigments white mustard wild mustard