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Effect of vertebral degeneration on the instability of spine 脊椎退变对脊柱不稳定性的影响
IF 0.6 4区 物理与天体物理
Lithuanian Journal of Physics Pub Date : 2020-04-28 DOI: 10.3952/physics.v60i2.4228
Olga Chabarova, R. Kačianauskas, V. Alekna
{"title":"Effect of vertebral degeneration on the instability of spine","authors":"Olga Chabarova, R. Kačianauskas, V. Alekna","doi":"10.3952/physics.v60i2.4228","DOIUrl":"https://doi.org/10.3952/physics.v60i2.4228","url":null,"abstract":"Insufficient exploration of the dependence between diseases of degenerative bones and the range of motion (ROM) during torsion, flexion and lateral bending limits further understanding about the lumbar biomechanics and treating of the lumbar related dysfunction. The objective of this study was to determine the effect of vertebral degradation on the instability of spine 2 motion L2–L4 segments during torsion, flexion and lateral bending by the finite element method (FEM). Three different 3D FE models comprising the healthy state and the degradation of trabecular bone and cortical bone were developed. Nonlinear numerical analyses of lumbar spine stability discovered that osteoporotic degradation can lead to critical segmental ROM and intervertebral shearing values, which results in the loss of spine stability for the case of flexion loading. Instability is caused by microscopic changes in the thickness of cortical shell. This analysis of the intervertebral shearing and ROM may be further used to diagnose such translation abnormalities like hypomobility or hypermobility.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48101010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Depopulation mechanism for incoherent terahertz source – THz torch – based on GaAsBi/GaAs quantum well in GaAs/AlGaAs parabolic quantum well GaAs/AlGaAs抛物量子阱中基于GaAsBi/GaAs量子阱的非相干太赫兹源太赫兹炬的退布居机制
IF 0.6 4区 物理与天体物理
Lithuanian Journal of Physics Pub Date : 2020-04-28 DOI: 10.3952/physics.v60i2.4226
M. Karaliūnas, A. Udal, G. Valušis
{"title":"Depopulation mechanism for incoherent terahertz source – THz torch – based on GaAsBi/GaAs quantum well in GaAs/AlGaAs parabolic quantum well","authors":"M. Karaliūnas, A. Udal, G. Valušis","doi":"10.3952/physics.v60i2.4226","DOIUrl":"https://doi.org/10.3952/physics.v60i2.4226","url":null,"abstract":"Parabolic quantum wells (PQWs) are known as a promising candidate for a compact terahertz (THz) source. PQWs have equidistant subbands that can be designed to be separated by few meV to meet the THz frequency range. To enhance the efficiency and power of THz emission from PQWs, a new approach is proposed by employing depopulation of the lowest subbands of PQW. In this work, the theoretical analysis of an incoherent THz torch device is presented. The findings suggest that the introduction of narrower band-gap GaAsBi/GaAs rectangular quantum well within the GaAs/AlGaAs PQW can alter subbands arrangement to enable a faster depopulation mechanism exploiting LO phonon scattering. The calculated radiative power spectra show the increase of oscillator strength between the rearranged subbands of PQW due to the added GaAsBi rectangular potential. The increased intersubband radiative transition probability can lead to an efficient compact incoherent THz source – THz torch.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49455846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Quantum paraelectricity and induced ferroelectricity by germanium doping of (PbySn1–y)2P2S(Se)6 single crystals 锗掺杂（PbySn1–y）2P2S（Se）6单晶的量子顺电性和感应铁电性
IF 0.6 4区 物理与天体物理
Lithuanian Journal of Physics Pub Date : 2020-04-28 DOI: 10.3952/physics.v60i2.4227
I. Zamaraite, A. Dziaugys, Y. Vysochanskii, J. Banys
{"title":"Quantum paraelectricity and induced ferroelectricity by germanium doping of (PbySn1–y)2P2S(Se)6 single crystals","authors":"I. Zamaraite, A. Dziaugys, Y. Vysochanskii, J. Banys","doi":"10.3952/physics.v60i2.4227","DOIUrl":"https://doi.org/10.3952/physics.v60i2.4227","url":null,"abstract":"In this paper we report a dielectric study on four single crystals Pb2P2S6, (Pb0.98Ge0.02)2P2S6, (Pb0.7Sn0.3)2P2S6 + 5% Ge and (Pb0.7Sn0.3)2P2Se6 + 5% Ge down to 20 K. A new quantum paraelectric state was reported in the Ge-doped samples at low temperatures. In all of these materials the non-classical T2 temperature dependences of inverse dielectric permittivity were observed. The dielectric constants of Pb2P2S6-based single crystals were measured between 20 and 300 K. The temperature dependences of dielectric permittivity were analysed on the basis of Barrett’s model as a signature of quantum paraelectricity.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46715872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Activation of high flux test module sample holder after IFMIF-DONES operation IFMIF-DONES操作后高通量测试模块样品支架的激活
IF 0.6 4区 物理与天体物理
Lithuanian Journal of Physics Pub Date : 2020-02-05 DOI: 10.3952/physics.v60i1.4161
S. Breidokaite, G. Stankūnas, A. Tidikas
{"title":"Activation of high flux test module sample holder after IFMIF-DONES operation","authors":"S. Breidokaite, G. Stankūnas, A. Tidikas","doi":"10.3952/physics.v60i1.4161","DOIUrl":"https://doi.org/10.3952/physics.v60i1.4161","url":null,"abstract":"Nuclear safety assessment in nuclear fusion devices relies on the Monte Carlo method based neutron transport calculations. This paper presents information about the calculation results of the activities and dose rates caused by neuron irradiation for the structural materials of the high flux test module sample holder of IFMIF-DONES. The neutron induced activities and dose rates at shutdown were calculated by means of the FISPACT-2010 code with data from the EAF-2010 nuclear data library. Neutron fluxes and spectra were obtained with MCNP neutron transport calculations. The activities and dose rates were calculated at the end of irradiation of the assumed device operation scenario for cooling times of 0 s – 1000 year. In addition, radionuclides with contribution of at least 0.5% to the total value of activation characteristics at the previously mentioned cooling times were identified. After the operation, the most active radionuclide is 55Fe, with an activity share ranging from 30% (M200) to 63% (M8), and at the end of the prediction it accounts for 86% of the total activity. The highest dose rates at the end of irradiation are attributed to 56Mn radionuclide. 54Mn and 60Co are the most dominant radionuclides during intermediate and long cool-down periods.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49374045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effect of meta substitution of methyl group on 2-hydroxypyridine: Spectroscopic investigation 甲基间位取代对2-羟基吡啶的影响:光谱研究
IF 0.6 4区 物理与天体物理
Lithuanian Journal of Physics Pub Date : 2020-02-05 DOI: 10.3952/physics.v60i1.4162
A. Srivastava, S. Saxena
{"title":"Effect of meta substitution of methyl group on 2-hydroxypyridine: Spectroscopic investigation","authors":"A. Srivastava, S. Saxena","doi":"10.3952/physics.v60i1.4162","DOIUrl":"https://doi.org/10.3952/physics.v60i1.4162","url":null,"abstract":"We have reported here the detailed investigation of the effect of methyl group substitution on the meta-position of the 2-hydroxypyridine molecule. Resonance enhanced multiphoton ionization (REMPI), FT-IR and Raman spectroscopic techniques have been used for the experimental study of the molecules. Ab initio calculations were used for theoretical investigations of the molecules. The origin band of the molecules 3-methyl-2-hydroxypyridine (3M2HP) and 5-methyl-2-hydroxypyridine (5M2HP) was observed at 33830 and 34105 cm–1 in their REMPI spectroscopy, and the bands assigned as a ππ* transition state. The vibronic coupling of nπ* and ππ* transition states took place in 3M2HP, thus some low intense bands near the origin band of the molecule were observed in the REMPI spectrum. However, there was no such kind of bands in 5M2HP. The π*–σ* hyperconjugation is responsible for the conformational change of the methyl group in 3M2HP upon excitation (S0 → S1).","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43591502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Black silicon quality control by conditions of nickel-assisted etching of crystalline silicon surfaces in photovoltaic devices 用镍辅助蚀刻光电器件中晶体硅表面的条件控制黑硅质量
IF 0.6 4区 物理与天体物理
Lithuanian Journal of Physics Pub Date : 2020-02-05 DOI: 10.3952/physics.v60i1.4164
M. Kamarauskas, M. Treideris, V. Agafonov, A. Mironas, V. Strazdienė, A. Rėza, A. Šetkus
{"title":"Black silicon quality control by conditions of nickel-assisted etching of crystalline silicon surfaces in photovoltaic devices","authors":"M. Kamarauskas, M. Treideris, V. Agafonov, A. Mironas, V. Strazdienė, A. Rėza, A. Šetkus","doi":"10.3952/physics.v60i1.4164","DOIUrl":"https://doi.org/10.3952/physics.v60i1.4164","url":null,"abstract":"Here we present a study of the nickel-assisted etching applied to form uniform black silicon layers on crystalline silicon substrates. We related the parameters used for technological process control (etchant, nickel thickness) to parameters of the obtained surface and explain the correlation using the etching model responsible for etching of the silicon covered by a thin nickel film. The increase in the thickness of the metal catalyst did not suppress the etching completely but allowed one to tune the roughness of the silicon surface. The rate of the electrochemical etching was additionally changed by adaptation of the proportion of components in the complex etchant. Depending on the intentionally selected conditions, the duration of the optimized process was from 3 to 10 min. The lowest optical reflection commonly accepted as the black silicon surface was obtained for the mixture with a low amount of the active etchant component. It was demonstrated that the method is acceptable to improve the characteristics of a photovoltaic cell.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47848466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Hybrid organic-inorganic Fe3O(TFBDC)3(H2O)3·(DMF)3 compound synthesized by slow evaporation method: Characterization and comparison of magnetic properties 慢蒸发法合成有机-无机杂化Fe3O（TFBDC）3（H2O）3·（DMF）3化合物：表征和磁性能比较
IF 0.6 4区 物理与天体物理
Lithuanian Journal of Physics Pub Date : 2020-02-05 DOI: 10.3952/physics.v60i1.4166
A. Laurikėnas, K. Mažeika, D. Baltrunas, R. Skaudžius, A. Beganskiene, A. Kareiva
{"title":"Hybrid organic-inorganic Fe3O(TFBDC)3(H2O)3·(DMF)3 compound synthesized by slow evaporation method: Characterization and comparison of magnetic properties","authors":"A. Laurikėnas, K. Mažeika, D. Baltrunas, R. Skaudžius, A. Beganskiene, A. Kareiva","doi":"10.3952/physics.v60i1.4166","DOIUrl":"https://doi.org/10.3952/physics.v60i1.4166","url":null,"abstract":"In this study for the synthesis of a hybrid organic-inorganic Fe3O(TFBDC)3(H2O)3·(DMF)3 compound a slow evaporation method has been suggested. THe synthesis product was characterized using X-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) coupled with SEM and electron paramagnetic resonance (EPR) spectroscopy. THe antiferromagnetic/weakly ferromagnetic behaviour of the synthesized sample was confirmed by magnetization measurements and Mössbauer spectroscopy. THe synthesized magnetic material could be itself tested for different medical applications and could be used as precursor material for the preparation of nanostructured iron oxides with a variety of useful properties for biomedicine.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41443939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Alternating current susceptibility and magnetisation of nanocrystalline Co2MnSi Heusler alloy films 纳米晶Co2MnSi Heusler合金薄膜的交流电磁化率和磁化性能
IF 0.6 4区 物理与天体物理
Lithuanian Journal of Physics Pub Date : 2020-02-05 DOI: 10.3952/physics.v60i1.4165
B. Vengalis, A. Maneikis, G. Grigaliūnaitė-Vonsevičienė, R. Juškėnas, A. Selskis
{"title":"Alternating current susceptibility and magnetisation of nanocrystalline Co2MnSi Heusler alloy films","authors":"B. Vengalis, A. Maneikis, G. Grigaliūnaitė-Vonsevičienė, R. Juškėnas, A. Selskis","doi":"10.3952/physics.v60i1.4165","DOIUrl":"https://doi.org/10.3952/physics.v60i1.4165","url":null,"abstract":"The Co2MnSi (CMS) Heusler alloy films with thickness d = 90 ÷ 110 nm were grown by DC magnetron sputtering on both nonheated and heated Si(100) and MgO(100) substrates. The films grown (annealed) at T ≥ 400°C demonstrated a nanocrystalline structure with a partially ordered B2 phase and traces of a highly ordered L21 phase as found from XRD measurements. The films deposited onto the nonheated substrates followed by annealing at Tann = 300 ÷ 500°C demonstrated a gradual increase of the saturation magnetisation, Msat, up to about 4.0 μB/f.u. (at 295 K) while the coercity field, Hc, of the films increased from about 10 to 12 kA/m with Tann increasing from 400 to 500°C. Unusually low Hc values of about 0.1 and 0.3 kA/m have been indicated for the films grown in situ at 400°C on MgO and Si, respectively. A significant increase of the Hc values found for the films grown in situ at Ts = 450°C and reduced Msat values for similar films grown at 500°C have been associated with the instability of the ordered L21 structure at high temperatures.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48944594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Charge carrier mobility dynamics in organic semiconductors and solar cells 有机半导体和太阳能电池中的载流子迁移动力学
IF 0.6 4区 物理与天体物理
Lithuanian Journal of Physics Pub Date : 2020-02-05 DOI: 10.3952/physics.v60i1.4160
V. Gulbinas
{"title":"Charge carrier mobility dynamics in organic semiconductors and solar cells","authors":"V. Gulbinas","doi":"10.3952/physics.v60i1.4160","DOIUrl":"https://doi.org/10.3952/physics.v60i1.4160","url":null,"abstract":"Charge carrier mobility in organic semiconductors is not a constant value unambigously characterizing some particular material, but depends on the electric field, temperature and even on time after it was generated or injected. The time dependence is particularly important for the thin-film devices where charge carriers pass the organic layer before mobility reaching its stationary value. Here we give a review of experimental techniques with ultrafast timeresolution enabling one to address the mobility kinetics and analyse properties of the time-dependent mobility in conjugated polymers and organic solar cells. We analyse kinetics during the charge carrier generation and extraction of free charge carriers. The mobility typically decreases by several orders of magnitude on a picosecond-nanosecond time scale; however, its kinetics also depends on the investigation technique. The mobility kinetics in blends for bulk heterojunction solar cells strongly depends on the stoichiometric ratio of donor and acceptor materials.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44808708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Estimation of the charged defect density from hot-electron transport studies in epitaxial ZnO 外延ZnO热电子输运研究中带电缺陷密度的估计
IF 0.6 4区 物理与天体物理
Lithuanian Journal of Physics Pub Date : 2020-02-05 DOI: 10.3952/physics.v60i1.4163
L. Ardaravičius, O. Kiprijanovič, M. Ramonas, E. Šermukšnis, A. Simukovic, A. Matulionis
{"title":"Estimation of the charged defect density from hot-electron transport studies in epitaxial ZnO","authors":"L. Ardaravičius, O. Kiprijanovič, M. Ramonas, E. Šermukšnis, A. Simukovic, A. Matulionis","doi":"10.3952/physics.v60i1.4163","DOIUrl":"https://doi.org/10.3952/physics.v60i1.4163","url":null,"abstract":"High-field electron transport measurements by applying short (few ns) voltage pulses on nominally undoped n-type Zn-polar ZnO epilayers are reported and interpreted in terms of the Boltzmann kinetic equation. The transient measurements do not demonstrate a significant change in the electron density up to 320 kV/cm electric field. This result together with the experimental data on the current allows one to estimate the electron drift velocity from the measured current: the highest value of ~2.9 × 107 cm/s is obtained at the pre-breakdown field of 320 kV/cm for the ZnO layer with the electron density of 1.5 × 1017 cm–3. The densities of double-charged oxygen vacancies (~1.6 × 1017 cm–3) and other charged centres (~1.7 × 1017 cm–3) are assumed for the best fit of the simulated and measured hot-electron effect. A correlation with the epilayer growth conditions is demonstrated: the higher Zn cell temperature favours the formation of a higher density of the oxygen vacancies (1.9 × 1017 cm–3 at 347°C).","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42731167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
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