Journal of Experimental and Theoretical Physics最新文献

{"title":"Development of a Security Fence Intrusion Detection Based on a Fiber Bragg Grating Sensor","authors":"S. M. Ali,&nbsp;A. I. Mahmood,&nbsp;S. K. Fandi,&nbsp;A. T. Lateef,&nbsp;M. K. Khalaf","doi":"10.1134/S1063776126601138","DOIUrl":"10.1134/S1063776126601138","url":null,"abstract":"<p>Fiber Bragg grating (FBG) sensors have significant advantages such as high sensitivity, small size, corrosion resistance, and resistance to electromagnetic interference. Therefore, it has become of great importance in the field of fiber optic sensors in recent times compared to conventional fiber optic sensors. Therefore, they are highly suitable for security fencing and protection systems applications to detect and locate intrusions at vital sites. In this research, a security fencing system based on fiber Bragg grating technology in the form of an array was designed and implemented to detect and locate intrusions at sites to be protected from hostile external intrusions. The research work included two aspects: the theoretical aspect, which was implemented using the Opt-system simulation program, and the practical aspect, which included the use of the first Bragg grating fiber operating at a wavelength of FBG1 (1545.3 nm) and the second Bragg grating fiber operating at a wavelength of FBG2 (1547.4 nm). The research results showed that fiber Bragg (FBG) networks are an innovative intrusion detection system in security surveillance applications, as they have many advantages over traditional surveillance tools. One of their most important features is that they are highly suitable for use in security fences to accurately locate intrusions in important strategic areas.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":"142 6","pages":"809 - 814"},"PeriodicalIF":1.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098376","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}

{"title":"Chirality of the Seeley–DeWitt Coefficients and Quartic Weyl Structure in Spectral Action","authors":"David Alfyorov","doi":"10.1134/S1063776126601060","DOIUrl":"10.1134/S1063776126601060","url":null,"abstract":"<p>It is proved that convolute Seeley–DeWitt coefficients for the Dirac operator on a Ricci-flat four-dimensional manifold can be decomposed as <span>({text{Tr}}({{a}_{{2n}}}) = {{f}_{n}}(p) + {{f}_{n}}(q))</span>, where <span>(p = {text{|}}{{C}^{ + }}{{{text{|}}}^{2}})</span> and <span>(q = {text{|}}{{C}^{ - }}{{{text{|}}}^{{text{2}}}})</span> are the squares of norms of self-dual and anti-self-dual Weyl tensors. The proof is supported by the <i>chirality theorem:</i> spinor connection generators <span>({{sigma }^{{rs}}} = frac{1}{4}[{{gamma }^{r}},{{gamma }^{s}}])</span> commute with chirality operator <span>({{gamma }_{5}})</span> in four dimensions, which renders the endomorphism of curvature <span>({{Omega }_{{mu nu }}})</span> block-diagonal in the chiral basis. The <i>crossed chiral correspondence</i> is established (the left spinor block is connected exclusively with the anti-self-dual Weyl tensor, while the right block is connected with the self-dual part using the decomposition in ’t Hooft symbols). On the quartic level (mass dimension 8), the theorem indicates that <span>({text{tr}}({{a}_{8}}))</span> contains only the combination <span>(c({{p}^{2}} + {{q}^{2}}))</span> with zero cross term <i>pq</i>, fixing ratio <span>({{({{C}^{2}})}^{2}}:({text{*}}CC{{)}^{2}} = 1:1)</span> exactly. The result is extended to the spectral triple of the Standard model on the nearly commutative <span>(M times F)</span> geometry. Using analysis of Molien’s series, three P-even quartic Weyl invariants are first reduced to two invariants using the Cayley–Hamilton identity, and then to a single effective structure due to chirality. This reduces the problem of three-loop finiteness for the spectral action from an overdetermined system to a single condition imposed on the ratio. It is shown that the exact hypothesis concerning the spectral renormalization for gravity <i>is excluded at the structural analysis level:</i> the graviton propagator is blind to chirality (is scalar in the transverse-traceless sector), and the sums over several eigenvalues on two loops and more generate cross terms <i>pq</i> outside the space of spectral functions. The exact obstacle is the multitrace structure of separated differences in the van Nuland–van Suijlekom approach applied to gravity, in which the metric changes the Dirac operator and does not appear as an internal fluctuation. Nevertheless, the violation is quantitatively negligible (cross terms are suppressed by factor <span>(alpha _{C}^{3}{text{/}}{{(16{{pi }^{2}})}^{3}} approx 3.2 times {{10}^{{ - 10}}})</span>, and the spectral action ensures the effective ultraviolet finiteness in the perturbative mode with a preset accuracy. All algebraic results are verified by numerical calculations on random Weyl tensor ensembles to within <span>( leqslant {{10}^{{ - 12}}})</span>.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":"142 6","pages":"870 - 881"},"PeriodicalIF":1.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098365","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}

{"title":"Noise Propagation of 6 hp Farm Diesel Engine","authors":"Naresh Kumar Chhuneja,&nbsp;Ramandeep Singh,&nbsp;Sumit Chopra","doi":"10.1134/S106377612660131X","DOIUrl":"10.1134/S106377612660131X","url":null,"abstract":"<p>Considering the undesirable effects of noise and long working hours of farm workers, a study was conducted to investigate noise propagation of a commonly used 6 hp farm diesel engine in operator’s workspace. Height of muffler from ground was 0.9 m and direction of water discharge pipe was towards right w.r.t muffler opening. Measurements of sound pressure level (SPL) was made in three vertical planes viz. at height equal to engine muffler, 0.5 m above and 0.5 m below. In each vertical plane, five horizontal radial distances of 0.5, 1.0, 1.5, 2.0, and 2.5 m were taken. The direction of muffler opening was taken as 0° and it increased in anticlockwise direction. A total of eight angles with increment of 45° were taken for direction of measurement in a given vertical plane. The mean SPL at muffler opening of diesel engine was 120.9 dB. Mean SPL varied from 71.2 to 99.4 dB among all the treatments. SPL decreased with the change in angle from 0° to 180° for both clockwise and anti-clockwise directions. SPL towards right side of muffler opening was comparatively higher because of noise generated by irrigation water. Considering the results obtained, the findings can be extended for possible use in tractor operator’s workspace. It was concluded that operator’s seat should be located at a maximum possible radial distance from the muffler. The muffler opening should be in the opposite direction w.r.t. the operator’s seat.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":"142 6","pages":"815 - 821"},"PeriodicalIF":1.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098368","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}

{"title":"Effect of Engine Oils on Self-Ignition of a Fuel–Air Mixture in the Combustion Chamber of a Rotary Piston Engine","authors":"A. L. Kozlov,&nbsp;V. M. Ezhov,&nbsp;M. A. Ilina,&nbsp;L. S. Yanovskiy","doi":"10.1134/S1063776126700135","DOIUrl":"10.1134/S1063776126700135","url":null,"abstract":"<p>The paper studies the effect of adding M-5z/20 AERO and AERO 2T engine oils on the flammability and combustion characteristics of Avgas 100 LL and TS-1 fuels, which can be used in aircraft rotary piston engines. Data on the flammability of fuel–air mixtures, including those with engine oil additives, were obtained using a shock tube in the temperature range of 700–1500 K and pressure range of 16–18 bar at a stoichiometric ratio with air. The combustion characteristics of fuels with oil additives were determined using a combustion chamber of the evaporative type. The completeness of combustion was determined at a mass flow rate of 0.1 kg/s and an air excess ratios of 1 and 2 for 10 min. Soot formation was determined at an air flow rate of 0.05 kg/s and air excess ratio α = 4 for 1 h.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":"143 1","pages":"1 - 6"},"PeriodicalIF":1.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098595","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}

{"title":"First-Principles Investigation of Pressure-Dependent Structural, Electronic, Vibrational, and Thermodynamic Properties of Zinc Blende CdTe under Hydrostatic Pressure","authors":"Mansy Samy","doi":"10.1134/S1063776126600911","DOIUrl":"10.1134/S1063776126600911","url":null,"abstract":"<p>This study presents a comprehensive first-principles investigation of the structural, electronic, vibrational, and thermodynamic properties of zinc blende (ZB) CdTe under hydrostatic pressure up to 50 GPa, using density functional theory (DFT) within the PBE-GGA framework as implemented in the CASTEP code. Cadmium telluride (CdTe) is a technologically important semiconductor widely used in thin-film photovoltaic devices, where CdTe-based solar cells have achieved conversion efficiencies of approximately 22%. The structural analysis reveals a monotonic reduction in the lattice parameter and unit cell volume with increasing pressure, confirming isotropic compression behavior consistent with the Birch-Murnaghan equation of state. The electronic band gap exhibits a pronounced non-monotonic pressure dependence, increasing from 1.59 eV at ambient pressure to a maximum of 2.22 eV at approximately 20 GPa, followed by a decrease to 1.63 eV at 50 GPa. This behavior is attributed to pressure-induced orbital redistribution and modifications at the band edges, primarily involving Te-5p and Cd-5s states, as elucidated by density of states (DOS) analysis. Vibrational properties, analyzed through Raman spectra, show a continuous blueshift in phonon wavenumbers with pressure, indicating bond stiffening and increased interatomic force constants, accompanied by significant variations in spectral intensity due to anharmonic effects. The thermodynamic response, including enthalpy, Gibbs free energy, heat capacity, and Debye temperature, demonstrates strong pressure sensitivity, reflecting modified lattice dynamics and reduced thermodynamic stability under compression. It is important to note that calculations beyond approximately 20 GPa were performed under constrained zinc blende symmetry to explore property trends and should be interpreted as indicative of metastable behavior. The results establish CdTe as a pressure-tunable semiconductor and identify ~20 GPa as a significant threshold for changes in its electronic and vibrational behavior, providing a valuable reference for future experimental and theoretical studies on CdTe under extreme conditions.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":"142 6","pages":"882 - 893"},"PeriodicalIF":1.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098201","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}

{"title":"Rear-Interface Engineering in Kesterite Solar Cells: Disentangling the Beneficial and Detrimental Effects of SnS","authors":"A. R. Latrous,&nbsp;N. Touafek,&nbsp;A. Taabouche","doi":"10.1134/S1063776126600947","DOIUrl":"10.1134/S1063776126600947","url":null,"abstract":"<p>Kesterite Cu₂ZnSnS₄ (CZTS) solar cells suffer from a persistent open-circuit voltage (<i>V</i>_OC) deficit, largely attributed to secondary phases and severe rear-interface recombination. In this work, a comprehensive SCAPS-1D numerical investigation is carried out to disentangle the dual role of the SnS secondary phase and to optimize rear-interface band engineering in CZTS solar cells. The influence of SnS thickness, acceptor concentration, defect density, and bandgap on device performance is systematically analyzed. Ultrathin SnS layers (~5 nm) are shown to induce a favorable spike-like conduction band offset (+0.15 eV), effectively suppressing electron recombination while preserving hole transport. In contrast, thicker SnS layers (&gt;50 nm) introduce parasitic absorption and resistive losses, leading to significant efficiency degradation. Furthermore, a comparative study of various back surface field (BSF) materials demonstrates that Cu₂O provides the most advantageous band alignment, enabling strong rear-field formation and efficient suppression of Shockley–Read–Hall recombination. An optimized device efficiency exceeding 12% is achieved, offering clear guidelines for mitigating the <i>V</i>_OC deficit in kesterite photovoltaics.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":"142 6","pages":"894 - 904"},"PeriodicalIF":1.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098203","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}

{"title":"Tailoring the Complex Dielectric Response and Achieving Bandgap Recovery in Single and Double Doped (Mg, Ni, Al) ZnO Thin Films","authors":"Maysam Shehab Ahmed,&nbsp;Abbas A. Kareem,&nbsp;Heba M. T. Khalil,&nbsp;Walaa Hussain Hamid","doi":"10.1134/S1063776126602016","DOIUrl":"10.1134/S1063776126602016","url":null,"abstract":"<p>Zinc oxide (ZnO) is a promising wide-bandgap semiconductor, yet isolated doping often induces structural disorder and optical energy dissipation. To address these challenges, this study investigates the structural, morphological, and opto-dielectric dynamics of mono- and co-doped (Mg, Ni, Al) ZnO thin films synthesized via spray pyrolysis. Structural characterization confirmed a stable hexagonal wurtzite lattice, revealing that while single Ni-doping caused excessive grain growth and morphological degradation, introducing synergistic dual-doping (Mg-Ni and Mg-Al) refined the microstructure and significantly enhanced surface homogeneity. By modulating the complex dielectric response governing both optical polarization and energy loss – the co-doping strategy successfully minimized defect-induced scattering, maintaining over 80% visible transmittance. Crucially, the targeted Mg-Ni co-doping effectively counteracted the detrimental band-narrowing caused by isolated Ni-doping, recovering the optical bandgap from 3.17 to 3.22 eV. Furthermore, these double-doping configurations substantially reduced structural disorder, as evidenced by a minimized Urbach energy and a suppressed extinction coefficient. These findings demonstrate that engineering the opto-dielectric properties through comprehensive single and double (Mg, Ni, Al) doping successfully overcomes structural degradation, optimizing the overall integrity of ZnO thin films for advanced optoelectronic and photovoltaic applications.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":"143 1","pages":"60 - 75"},"PeriodicalIF":1.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098610","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}

{"title":"Analysis of a Plastic Collision to Determine the Mass of a Bit","authors":"Jorge Reyes-Molina","doi":"10.1134/S1063776126601746","DOIUrl":"10.1134/S1063776126601746","url":null,"abstract":"<p>The possibility that information measured in bits has an associated equivalent mass has been argued by Vopson, who relied on Landauer’s principle, leading to the mass-energy-information equivalence principle. This principle states that the mass of a bit stored in classical digital memory at 300 K is on the order of <span>(3.19 times {{10}^{{ - 38}}}~)</span> kg, implying that a 1 TB device must increase its mass by <span>(2.5 times {{10}^{{ - 25}}}~)</span> kg to move from the erased state to the full digital information state. Similarly, in this work, we explore how an ideal gas can increase its mass owing to an increase in its entropy, based on the fact that information and entropy are related by an identity. Specifically, we have established that when one mole of an ideal gas changes its temperature from 50 to 4000 K, its entropy content increases by <span>(5.71 times {{10}^{{24}}})</span> bits, while its mass increases by <span>(5.47 times {{10}^{{ - 13}}}~)</span> kg. These calculations reaffirm the possibility that information is the fifth state of matter and that the mass-energy-information equivalence principle is correct.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":"143 1","pages":"38 - 42"},"PeriodicalIF":1.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098607","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}

{"title":"Rashba Spin–Orbit Interaction in Quantum Dot Superlattices with Position-Dependent Effective Mass and Its Impact on Intersubband Optical Absorption","authors":"G. B. Ibragimov,&nbsp;B. G. Ibragimov,&nbsp;Z. S. Agayev","doi":"10.1134/S1063776126601710","DOIUrl":"10.1134/S1063776126601710","url":null,"abstract":"<p>We present a theoretical study of Rashba spin–orbit interaction in quantum dot superlattices (QDSLs) with position-dependent effective mass (PDEM) under asymmetric confinement potentials. Within a Hermitian effective-mass framework combined with a tight-binding approach, we derive Rashba-split miniband structures and the corresponding Bloch spinor wavefunctions. It is shown that the mass-gradation parameter β provides an efficient mechanism for controlling interdot tunneling, leading to a pronounced modulation of miniband width and wavefunction localization. The intersubband optical absorption is analyzed using dipole transition matrix elements between Rashba-split miniband states. The results reveal that the absorption spectrum is highly tunable: PDEM primarily governs the spectral position and intensity of the absorption peaks, whereas Rashba interaction induces a characteristic spin dependent splitting. The nearly linear dependence of peak splitting on αR clear optical signature of spin–orbit coupling. These findings demonstrate that QDSLs with PDEM offer a versatile platform for engineering spin-dependent electronic and optical properties, with promising applications in spintronics and terahertz optoelectronic devices.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":"143 1","pages":"43 - 48"},"PeriodicalIF":1.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098609","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}

{"title":"Improving the Wear Resistance of Alloy Steel by Isothermal Stepwise Nitriding","authors":"L. G. Petrova,&nbsp;I. S. Belashova,&nbsp;M. A. Frolov,&nbsp;P. S. Bibikov","doi":"10.1134/S106377612660248X","DOIUrl":"10.1134/S106377612660248X","url":null,"abstract":"<p>The article investigates an isothermal staged nitriding process for 40KhN2MA structural steel, comprising a saturation stage in an ammonia–air mixture followed by a stage in pure ammonia. Experimental data reveal the patterns of nitride zone formation as a function of temperature and the total duration of the staged process. The effect of nitriding regimes on the growth kinetics and microhardness of the nitrided layer is examined. Tribological tests demonstrate improved wear resistance of the nitrided steel, characterized by an extended run-in period, a reduced friction coefficient, and decreased linear wear parameters. An optimal staged process regime is determined to produce a nitrided layer structure that ensures maximum wear resistance under dry sliding conditions.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":"143 1","pages":"7 - 12"},"PeriodicalIF":1.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098612","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}