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Quanta of light (single photon) play as one of building blocks of photonic based quantum computations, sensing and communications. This makes a necessity to develop practical approaches for tuning, guiding and coupling of single photons in photonic circuits for viable applications. Interaction and coupling efficiency of Single photon into optical fibers is a technical bottleneck of quantum optics and should be addressed by novel design and materials. Here, we introduce a fiber-based micro-photonic design to directly and efficiently coupling of the emitted single-photon to the core of a single mode fiber (SMF), the results of simulation indicate that emission of single photon source on a D-shaped SMF coated by a thin plasmonic film, provide remarkable amplifying of evanescent field by confined surface plasmons into the SMF. The numerical analysis on different types and thicknesses of plamsonic materials by finite element method (FEM) is conducted to study the propagation vectors along the SMF as function of emission angle and wavelength of the single photon source. The results revealed that by optimum thickness of tantalum layer as novel plasmonic material, the best record of coupling efficiency as high as 60% can be achieved in fiber optic communication region (∼1550 nm). This approach shed a light on novel plasmonic assisted coupling and promises a functional strategy for single photon manipulating in various field of quantum optics.

Thin layers of enhanced electron density, detected at the altitude range of 90 to 120km, are referred to as Sporadic E and abbreviated as Es. Wind shear theory is the most commonly accepted physical mechanism for mid-latitude Es layer formation. According to wind shear theory Es layers form by the convergence of metallic ions in the ionosphere dynamo region due to vertical shears of the neutral wind mainly caused by tides in the lower thermosphere. Apart from atmospheric tides, planetary waves can also contribute to wind shear formation in the lower thermosphere. Previous studies based on ground-based measurements suggested that planetary waves with periods of several days play a role in the day-to-day variation of Es intensity.The purpose of this study is to determine the role of planetary waves in the day to day variation of Es layer. For this investigation, radio occultation data of FORMASAT-3/COSMIC2 and Spire have been used. The use of the global data based on satellite measurements makes it possible to investigate the zonal structure of planetary wave signatures in Es. The results will be compared to planetary waves in the dynamo-region winds as simulated by the GAIA (Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy) model., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Two main methods used in the study of the Es layer are ground-based measurements and satellite observations. In this study, we compare mid- and low-latitude Es layer observations of FORMOSAT-3/COSMIC radio occultation with those recorded in ground-based digisonde stations. For this purpose, we have used a 2° latitude x 5° longitude grid around ionosonde sites, and compared ionosonde Es recording with GNSS radio occultation measurements of the Es layer within that grid.Es layer measurements of a multi-year radio occultation data set has been compared with conjunction Es recordings from six ionosonde stations in mid and low latitudes. It has been found that in more than 20% of cases Es layers detected by those two methods do not agree. The spatial and temporal dependence of their agreement has been discussed. This study suggests that Es layer recordings using ground-based ionosonde observations has the best agreement with the Es layers measured by radio occultation data during daytime and local summers., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The wind shear theory is widely accepted as an explanation for the formation of a sporadic E (Es) layer, but the direct comparison of Es with the local wind shear has been limited due to the lack of neutral wind measurements. This study examines the role of the vertical wind shear for Es, using signal‐to‐noise ratio profiles from COSMIC‐2 radio occultation measurements and concurrent measurements of neutral wind profiles from the Ionospheric Connection Explorer. It is observed that the Es occurrence rate and average S4 index are correlated with the negative vertical shear of the eastward wind, providing observational support for the wind shear theory. Es can be observed even when the vertical wind shear is positive, which is interpreted as metallic ion layers generated at an earlier time., Plain Language Summary: Sporadic E (Es) is anomalous radio propagation resulting from intense clouds of ionization at heights of the E‐region ionosphere (90–120 km). The formation of an Es layer is generally attributed to the vertical wind shear, which can move metallic ions in the vertical direction by the Lorentz force. According to the wind shear theory, a negative shear of the eastward wind is effective in converging the metallic ions into a thin layer to produce Es. Although previous observations and modeling studies have supported the theory to various degrees, the direct comparison of Es with the vertical wind shear has been limited due to sparse observations of neutral winds at E‐region heights. Neutral wind profiles from the Ionospheric Connection Explorer mission, together with Es data from COSMIC‐2 radio occultation measurements, provide an opportunity to fill this knowledge gap. Direct comparisons of these measurements reveal that the Es occurrence rate is higher and lower for larger negative and positive wind shears, respectively, providing observational evidence for the wind shear theory., Key Points: Conjunction observations of sporadic E (Es) from COSMIC‐2 and neutral wind profiles from Ionospheric Connection Explorer/Michelson Interferometer for Global High‐Resolution Thermospheric Imaging are analyzed. Es occurrence rate correlates with the negative vertical shear of eastward wind, providing observational evidence for the wind shear theory. Es can be observed even when the vertical shear of the local eastward wind is positive., Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659, NASA, DFG Priority Program Dynamic Earth

In this paper, a dual-core D-shaped photonic crystal fiber (PCF) based surface plasmon resonance (SPR) refractive index sensor coated by tantalum in two segments has been designed and studied. The sensing performance of the proposed sensor in the visible to near infrared (800–1300 nm) region for detecting low refractive index analytes is numerically investigated. The finite element method (FEM) is used to design and study the influence of different structure parameters by the optical loss spectrum on the sensing performance of the sensor. The chemically stable plasmonic material tantalum (Ta) is used to produce excitation between the core and plasmonic modes. On a pure silica (SiO2) substrate, a rectangular structured dual core is used to facilitate the coupling strength between the cores and the surface plasmon polariton (SPP) mode and thus improves the sensing performance. By tuning the geometric parameters, simulation results show a maximum wavelength sensitivity of 10400 nm/RIU (Refractive Index Unit) for analyte refractive indices ranging from 1.25 to 1.39. The sensor also attains a maximum figure of merit (FOM) of 35.25 /RIU and fine refractive index resolution of 9.615 × 10 −6 RIU. Owing to Ta chemical stability, low cost, simple structure, high sensitivity, relatively high FOM and improved sensing resolution, the proposed sensor is suited for real-time, inexpensive and accurate detection of biomedical and biological analytes, bimolecular, and hazardous corrosive gases.

In this paper, a plasmonic refractive index sensor using a D-shaped optical fiber coated by tantalum has been proposed. The interaction between fiber fundamental mode and plasmonic mode which lead to the formation of resonance peaks depending on the analyte refractive index (RI) are investigated in detail. Using spectral sensitivity methods, the sensing performance of the proposed sensor for detecting analytes is numerically studied. The effect of various design parameters of proposed sensor are optimized numerically to achieve the maximumwavelength sensitivity. The proposed D-shaped optical fiber sensor has a RI detection range of 1.30 to 1.43 and exhibits a non-linear increasing spectral sensitivity from 1300 nm/RIU to 3900 nm/RIU. The proposed RI sensor is attractive for detecting different RI chemical and biochemical samples due to simple design, relatively large detection range, cost-effective, non-toxic nature and highly corrosion resistivity plasmonic material.

Nowadays, being accountable or having effective accountability mechanisms is essential for success of any organization. This study aims at investigating the impact of tax system’s accountability on improving taxpayers’ voluntary tax compliance in tax offices in Mazandaran province of Iran. In the present study, a mixed research method is employed and as accountability is here taken as ‘responsiveness’, the Delphi technique is first used to identify the legitimate expectations and demands of the taxpayers. In the second step, 4 types of accountability mechanisms are identified as the components of overall accountability. In the third step, using partial least squares path modeling via Smart PLS software, the impact of tax system's accountability on public trust as well as the impact of public trust on voluntary tax compliance is tested. The variables of the research are also analyzed employing one-sample t - test . The obtained results indicate that tax system's accountability affects voluntary tax compliance through affecting taxpayers’ public trust. Furthermore, in the case that the political accountability is not at the optimal level, the optimality of managerial and legal accountability does not have a significant impact on voluntary tax compliance. Finally, it is suggested that in order to achieve an overall accountability, more attention should be paid to the mechanisms of political accountability in the political sector and social accountability in both the political and administrative sectors of the tax system.

The formation of a sporadic-E (Es) layer at mid and low latitudes is generally attributed to the vertical wind shear, which is predicted to cause vertical ion convergence. According to wind shear theory, a negative shear of the eastward wind is effective in converging metallic ions into a thin layer to produce Es. However, the direct comparison of Es with the local wind shear has been limited due to the lack of neutral wind measurements. This study examines the role of the vertical wind shear for Es, using signal-to-noise ratio profiles from COSMIC-2 radio occultation measurements and concurrent measurements of neutral wind profiles from the Ionospheric Connection Explorer (ICON). We find that the Es occurrence rate is correlated with the negative vertical shear of the eastward wind, providing observational support for the wind shear theory.

We analyze sporadic E (ES) occurrence rates (OR) obtained from ionospheric radio occultation measurements by the FORMOSAT-3/COSMIC constellation. Maximum OR are seen at 95 - 105 km altitude at lower midlatitudes. Midlatitude ES are mainly due to wind shear in the presence of tides, and the strongest signals are a migrating diurnal and semidiurnal com- ponent. Especially at high latitudes of the southern hemisphere, nonmigrating components such as a diurnal westward wave 2 and a semidiurnal westward wave 1 are also visible. Near the equator, a strong diurnal eastward wavenumber 3 component and a semidiurnal eastward wavenumber 2 component is found in summer and autumn. Terdiurnal and quarterdiurnal components are weaker than the diurnal and semidiurnal ones

Irregular topography induces non-uniform excitation in the supports of large structures such as dams and bridges. The present study employs the 3-dimensional boundary element method to achieve the seismic response of Pacoima Dam’s valley and compares the numerical results with the real responses recorded during the 2001 Pacoima earthquake. The horizontal components recorded on the bottom of the valley are used as the input wave for the analysis. The time history of displacements and amplifications of different points are examined. The results revealed that the amplification factor enhanced from bottom to the top of the valley for the most frequencies. The displacement amplification ratio reached approximately 3 along the valley, suggesting the necessity for considering the non-uniform motions effects on huge structures.

Currently, designers require to use numerous incomplete data sources and make multiple assumptions to conduct an LCA. We argue that traditional methods are incapable of addressing LCA data requirements, and for such a data and meta-data intensive task, the semantic web is the only logical choice of technology. This paper presents a review of the semantic web and its applications in the construction industry, along with an overview of the current LCA tools. LCA challenges are thoroughly discussed, and a framework using the semantic web is developed to address the data management issues of BIM-LCA applications. For comparison, the implementation is also done using an LCA tool (Tally), and a method using Relational Database Management Systems (RDBMS). Results show that the proposed method is superior to RDBMS methods in terms of capturing semantics and can improve LCA tools by providing reliable data in the early design stages.

When the bridge piers are located in front of the water flow, vortices are formed against it and due to their activity, the materials of the river bed are eroded around the bridge piers and the scouring hole is created. If the foundation depth and bridge pier piles are insufficient, the bridge will fail. Now, due to the importance of identifying the mechanisms affecting the scouring on this types of bridge piers, the effect of the geometric shape of the piles that installed under the inclined piers and also the effect of the pile cap leveling in the sedimentary bed have been investigated and the properties of the scouring around the inclined pier group was studied numerically and using the Flow-3D software. The study of total shear stress in the flow bed at different leveling of the pile caps shows that of the highest shear stress was created when the pile cap position is at the same level with the river bed and by installing the pile cap at a lower level than the river bed, the maximum shear stress decreases. This may be due to the fact that in this case the distance between the pier group increases and the presence of the second pier decreases the flow rate in the pier group and different pier in the one pier group act as the two Independent piers in the formation of flow pattern. By comparing the final longitudinal sections of the scouring at different leveling of the pile cap, it is concluded that the largest reduction in scouring depth occurs in aerofoil-shaped pile caps and pile caps with the sharper nose and better aerodynamic shapes are good options to control the horseshoe vortices and will reduce the scouring depth around the inclined pier group.

The aim of this study is the evaluation of electron dose enhancement and photon contamination production by various nanoparticles in the electron mode of a medical linac. MCNPX Monte Carlo code was used for simulation of Siemens Primus linac as well as a phantom and a tumor loaded with nanoparticles. Electron dose enhancement by Au, Ag, I and Fe2O3 nanoparticles of 7, 18 and 30 mg/ml concentrations for 8, 12 and 14 MeV electrons was calculated. The increase in photon contamination due to the presence of the nanoparticles was evaluated as well. The above effects were evaluated for 500 keV and 10 keV energy cut-offs defined for electrons and photons. For 500 keV energy cut-off, there was no significant electron dose enhancement. However, for 10 keV energy cut-off, a maximum electron dose enhancement factor of 1.08 was observed for 30 mg/ml of gold nanoparticles with 8 MeV electrons. An increase in photon contamination due to nanoparticles was also observed which existed mainly inside the tumor. A maximum photon dose increase factor of 1.07 was observed inside the tumor with Au nanoparticles. Nanoparticles can be used for the enhancement of electron dose in the electron mode of a linac. Lower energy electron beams, and nanoparticles with higher atomic number, can be of greater benefit in this field. Photons originating from nanoparticles will increase the photon dose inside the tumor, and will be an additional advantage of the use of nanoparticles in radiotherapy with electron beams.

The purpose of this study was to investigate the relationship between 25-m sprint front crawl swimming performance and muscle fascicle length in young male swimmers. 23 swimmers were selected and divided into two groups according to their best records of 25-m sprint performance: 14.6-15.7 sec (S1, n = 11) and 15.8-17 sec (S2, n = 12). Muscle thickness and pennation angle of Biceps Brachii (BB; only muscle thickness), Triceps Brachii (TB), Vastus Lateralis (VL), Gastrocnemius Medialis (GM) and Lateralis (GL) muscles were measured by B-mode ultrasonography, and fascicle length was estimated. Although, there was no significant differences between groups in anthropometrical parameter as standing height, body mass, arm length, thigh length and leg length (p < 0.001), however, S1 significantly had a greater muscle thickness in VL, GL, and TB muscles (p < 0.05). Pennation angle only in TB was significantly smaller in S1 (p < 0.05). S1 in VL, GL, and TB muscles significantly had greater absolute fascicle length and in VL and TB muscles had relatively (relative to limb length) greater fascicle length (p < 0.05). Moreover, there was a significant relationship between sprint swimming time and absolute and relative fascicle length in VL (absolute: r = -0.49 and relative: r = -0.43, both p < 0.05) and GL (absolute: r = -0.47 and relative: r = -0.42, both p < 0.05). Potentially, it seems that fascicle geometry developed in muscles of faster young swimmers to help them to perform their high speed movement.

The aim of the present study was to evaluate the biomechanical (stroke rate, stroke length, and stroke index), anthropometrical (body height, body mass, body mass index, arm span, shoulders width, thigh, leg and upper arm lengths), and muscle architectural (muscle thickness, pennation angle, and fascicle length) parameters as predictors of 200-m front crawl swimming performance in young male swimmers. Twenty-two county level male swimmers (mean ±SD: age: 14.52 ± 0.77 years; body height: 173 ± 5 m; body mass: 60.5 ± 5.7 kg) performed a 200-m front crawl swimming test in a 25-m pool. Stepwise regression analysis revealed that biomechanical parameters (87%) characterized best 200-m front crawl swimming performance, followed by anthropometrical (82%) and muscle architectural (72%) parameters. Also, stroke length (R2 = 0.623), body height (R2 = 0.541), fascicle length of Triceps Brachii (R2 = 0.392) were the best single predictors that together explained 92% of the variability of the 200-m front crawl swimming performance in these swimmers. As a conclusion, with respect to higher performance prediction power of biomechanical parameters, technique should represent the core of the training program at these ages. In addition, these findings could be used for male young swimmers selection and talent identification.