Transmission Coefficients Research Articles

Resiliency evaluation of sheltering in a net-zero energy house during summer power outage

This study examines the growing issue of power outages caused by natural disasters and proposes the use of net-zero energy houses (ZEH) as a safe alternative to traditional shelters. A ZEH, equipped with an independent energy system, can maintain essential living standards such as thermal comfort and 24-hour air conditioning during a summer power outage, reducing the risk of heatstroke. The research tested a ZEH in Japan, confirming its ability to support critical household appliances like refrigerators, lighting, and water heaters for up to 72 h. This demonstrates the ZEH's potential for offering safe, comfortable shelter during emergencies while addressing problems like poor sanitation and lack of privacy found in typical shelters. The experimental ZEH is located in Shizuoka, Japan, is a steel structure, and has a floor area of 110.94 m2 and overall heat transmission coefficient (UA) of 0.48 W/m2·K. The ZEH was equipped with a 5.1 kW photovoltaic system and 5.6/11.2 kWh storage battery (BT), which produced an output of up to 2.0/4.0 kVA. A ZEH with a 5.6 kWh BT can provide for ventilation and living/dining room/kitchen air conditioning (AC), refrigerator, television, lighting, mobile phone charging, rice cooker, microwave, electric kettle, and heat pump water heater during a 72-h power outage. The ZEH with a 11.2 kWh BT can also provide bedroom AC and high-load home appliances for lunch and dinner, in addition to a 5.6 kWh BT. The use of AC in a self-supporting circuit maintained the thermal environment at a low heat stroke risk.

Methodical approach to determining the main parameters of the evacuation system for the wounded with the use of different types of transport

The timeframe for evacuating the wounded is a critical factor that largely determines the fate of a wounded soldier. Even at the initial stage of the war waged by the russian federation against Ukraine, there were almost no frontline ambulances, and there was a critical shortage of ambulances. At present, despite significant efforts to provide the Armed Forces of Ukraine with weapons and military equipment, as well as material and technical means, including medical equipment and property, in particular through international technical assistance, the problem of the lack of the required number of specialised medical evacuation vehicles has not been fully resolved. From this point of view, the issue of correct formulation of requirements for the rational composition and specially equipped various types of vehicles (including sanitary transporters, ambulances), including general use, the system of evacuation of the wounded, and determining the possibility of its further improvement through the methodological apparatus is relevant. The purpose of the article is to present a methodological approach to determining the main parameters of the system of evacuation of the wounded of an operational group of troops with the involvement of various types of transport. The formation of a model of the casualty evacuation system as a mass service network (MSN) will minimise the time spent waiting for medical care by wounded personnel, determine the rational composition of forces and means of the tactical casualty evacuation system. To model the system and processes of evacuation of the wounded from the battlefield during hostilities, including their transportation to medical facilities located in the depths of the third logistics zone, the mathematical apparatus of the theory of mass service was used. In particular, we are talking about the devices of queuing systems (QS) and MSN. The existing system of military evacuation of the wounded and sick is a four-tier system in which all wounded with moderate and severe severity are evacuated. Based on this, the system of evacuation of the wounded can be represented as an MSN, which has a number of features. First of all, this MSN is an open queuing network (OQN), i.e. the flow of requests to enter the network is unlimited, homogeneous and comes from an external independent source. As a result of the calculations, data were obtained on the values of network parameters (average number of applications in queues – 119.47 applications/hour, average number of applications in the network – 158.53 applications/hour, average waiting time for applications in queues for service – 11.95 hours, average time of application stay in the network – 15.85 hours) and the parameters of each QS operating in the MSN – transmission coefficient, incoming flow intensity, load factor, average number of busy channels, average number of applications per QS, average queue length, average waiting time for an application in the service queue, average time for an application to stay in the QS. Analysing the calculated data, from the point of view of creating a rational OQN, the casualty evacuation system achieves maximum efficiency when its productivity in processing the incoming flow of requests is maximised, and the minimum values of such parameters as the number of requests for service in the queue and the number of service channels operating in the network are minimal.

Oblique Wave Scattering by a Pair of Asymmetric Inverse Π-Shaped Breakwater

Abstract The topic of wave scattering by different breakwaters has unfolded over the past few decades, largely driven by the profound impacts of global climate change. In this study, a completely new type of breakwater, inverse Π-shaped breakwater, has been taken into account for serving both purposes from analytical as well as an application point of view. During the formulation, the actual physical problem is transferred into a boundary value problem by employing the small amplitude water wave theory. With the aid of eigenfunction expansion, the problem is reduced to a set of integral equations having square-root singularities at the submerged edges of thin structures. To address such singularities, a multi-term Galerkin approximation technique is used along with Chebyshev polynomials (multiplied with suitable weights) as basis functions. The numerical methodology employed here validates with different previous literatures as special cases. Then, numerical solutions of the reflection and transmission coefficients, hydrodynamic forces are graphically illustrated across various dimensionless structural parameters. In summary, the present paper offers valuable insights into the dynamics of wave scattering by a pair of asymmetric inverse bottom-mounted Π-shaped breakwater, emphasizing the role of different non-dimensional parameters in this system.

Diagnostic And Post-Therapeutic Histopathology Of Hansen’s Disease in a Man With Rheumatoid Arthritis

Abstract Introduction/Objective Hansen’s Disease (leprosy), caused by Mycobacterium leprae, is a chronic infectious disease primarily affecting the skin and peripheral nerves. In the United States, leprosy remains rare, with less than 200 cases per year reported to the CDC. Diagnosis is often delayed, due to low clinical suspicion and lack of experience among healthcare providers, leading to potentially severe complications and increased transmission risk. Methods/Case Report A 71-year-old man presented to dermatology with a progressive, non-tender erythematous rash involving the arms and chest. He denied any travel history, or exposure to armadillos, and had no family history of a similar rash. His medical history was significant for rheumatoid arthritis, for which he was receiving methotrexate. The clinical differential included drug eruption, tinea infection, or sarcoidosis. Skin biopsy revealed extensive infiltration of the dermis by noncaseating granulomas surrounding cutaneous nerves, and AFB stain highlighted numerous bacilli consistent with Mycobacterium leprae, leading to the diagnosis of Hansen’s disease. The WHO classification was multibacillary leprosy, and the Ridley-Jopling classification was borderline tuberculoid (BT) to perhaps mid borderline (BB), based on clinical and histologic features. He was started on triple therapy, and biopsies performed during treatment, as well as at three years follow up showed marked improvement, with some remaining disease detected in unresolved rash. Results (if a Case Study enter NA) NA Conclusion This case presents a diagnostic challenge given the absence of typical risk factors for Mycobacterium leprae transmission. The patient’s immunocompromised status due to methotrexate therapy may have predisposed him to the disease. Documented cases of Hansen’s disease have more than doubled in the southeastern states since 2013, with concern for endemic regions emerging in Florida. Early recognition, classification, and prompt treatment are essential to prevent disease progression and reduce transmission. Increased education and awareness among healthcare providers are crucial to improving diagnostic accuracy and patient outcomes in cases of leprosy.

Investigation of optical fiber line with a positive transmission ratio of analog microwave signal

The influence of optical radiation power on the one-decibel compression point, harmonic distortion and dynamic range due to interference in a fiber-optic transmission line of an ultra-high frequency (microwave) signal has been studied. The line had a positive microwave signal transmission coefficient, and there were no amplification elements between the input and output. The amplification effect was achieved through the use of increased power of the carrier optical radiation and a photodetector with a high photocurrent. It has been shown that an increase in optical radiation power leads to a decrease in one-dB compression power and an increase in harmonic distortion, but an increase in optical radiation power does not lead to a change in the dynamic range of interference. It was found that the dynamic range free from interference was about 85…87 dB.

Microwave planar resonator-based sensor for pharmaceutical tablet-moisture characterization based on complementary symmetric meander line-shaped structure

ABSTRACT This paper presents a microwave planar resonator-based sensor for moisture sensing application. The resonator sensor is designed utilising the Complementary Symmetric Meander Line-Shaped Resonator topology and operated in the S-band with the frequency range of 2.6–3.3 GHz. The main design criteria of this sensor are based on low manufacturing complexity and cost, ease of fabrication and integration with existing equipment, despite its high sensitivity and accuracy. When this sensor is loaded/unloaded with four different Material Under Tests with relative permittivity values varying from 2.3 to 4.3, the electromagnetic simulations were validated against experimental measurements according to the resonant notch frequency of transmission coefficient for the sensor’s material-characterisation performance. The simulated and experimental results show good agreements on the resonant frequencies and demonstrate the sensor’s high performance with a normalised sensitivity of 6%. Resonant frequencies are well correlated with material permittivity using a quadratic-polynomial regression with R 2 = 0.999. Moreover, moisture-content percentages of both dry and moist paracetamol tablets, measured by a loss-on-drying moisture analyser between 1.74% and 17.72%, have good correlation with the sensor’s resonant-frequency shift from on-line measurements. This resonator sensor has exhibited the potential for detecting moisture contents in small-sized materials in various industries.

Universality of the Spectra of Multiterminal Josephson Junction

Andreev bound states are formed in multiterminal structures based on normal metals and superconductors. Their spectrum is determined by the system parameters, in particular the scattering phases and transmission coefficients at the nodes. The article found conditions under which Andreev bound states are universal: they don’t change with any change in the reflection phases. As a consequence, the spectrum is completely determined by the transport characteristics of the system. The result was obtained for a structure in the form of a normal metal M-finite star, each of the rays (terminals) Nk of which is in contact with its superconductor Sk, 1 ≤ k ≤ M. Together they form a multiterminal Josephson junction. At the center of the structure there is a non-magnetic impurity with its some scattering matrix.

Wideband microwave frequency response measurement based on optical phase-locked loop

Frequency response measurement, or the forward transmission coefficient (S21) measurement for a two-port network, is the key function of a vector network analyzer (VNA). In this paper, a broadband and high dynamic range (DR) microwave S21 parameter measurement scheme based on an optical phase-locked loop (OPLL) is proposed. By heterodyning two phase-locked hybrid integrated ultra-narrow linewidth lasers, a microwave signal with low phase noise and spurious level is generated as the incident signal and reference signal, and the signal frequency can be easily manipulated over a wide range by tuning the master laser wavelength. In the receiver, the radio frequency (RF) signals are down-converted to intermediate frequency (IF) signals with the phase-locked lasers. By sampling and processing the IF signals the S21 parameter of the DUT can be acquired. A proof-of-concept experiment is performed, and with available photodetectors, phase modulators and phase-locked loops, a measurable range of 2 to 18 GHz is achieved. The demonstrated minimum frequency resolution of the OPLL-based RF signal synthesizer is 10 Hz. The system DR exceeds 68 dB at an equivalent resolution bandwidth of 1 kHz. The S21 parameters of a power divider and a bandpass filter are measured, and the results are well consistent with those of a commercial VNA. The DR and measurable range limit factors and possible extension methods are discussed. The proposed approach offers a high potential way to develop a wideband, high DR, and fully integrated VNA.

A 3D-Printed Bi-Material Bragg-Based Reflectarray Antenna.

This paper presents a 3D-printed fully dielectric bi-material reflectarray with bandgap characteristics for multi-band applications. To achieve bandgap characteristics, a "1D Bragg reflector" unit cell is used. The latter is a layered structure characterized by a spatial distribution of refractive index that varies periodically along one dimension. By appropriately selecting the dimensions, the bandgap can be shifted to cover the desired frequency bands. To validate this bandgap characteristic, a (121.5 mm × 121.5 mm) with an f/D ratio of 0.5 reflectarray was fabricated. The measured gain at 27 GHz is 27.22 dBi, equivalent to an aperture efficiency of 35.05%, demonstrating good agreement between simulated and measured performances within the frequency range of 26-30 GHz. Additionally, the transparency of the reflectarray was verified by measuring the transmission coefficient, which exhibited a high level of transparency of 0.32 dB at 39 GHz. These features make the proposed reflectarray a good candidate for multi-band frequency applications.

Dual-wavelength transmission based on liquid crystal tunable filter with high signal-to-noise ratio

Aiming at the problem of limited transmission energy of liquid crystal tunable filter (LCTF), a dual-wavelength transmission system with high signal-to-noise ratio (SNR) is proposed in this paper. The proposed transmission factor Qp is the main influence on the number and location of transmission wavelengths as well as the bandwidth of each transmission wavelength for dual-wavelength systems. Dual-wavelength LCTF can improve the effective transmission energy of the system by increasing the number of filtering channels, and the transmission energy can be increased by about 1.8 times and 70% at short and long wavelengths, respectively, which improves the signal-to-noise ratio (SNR) of the system. Moreover, the dual-wavelength LCTF system is even possible to increase the transmission energy by about 7% at a 33% increase in spectral resolution. Therefore, the dual-wavelength LCTF transmission method not only can improve the SNR of target detection with dual-wavelength response features, but also can effectively solve the problem of contradiction between spectral resolution and spectral transmission energy.

Associated Factors of Viral Hepatitis Transmission among Hemodialysis Adult Patients

Background: Individuals suffering from chronic kidney disease (CKD) are more likely to die, particularly those with end-stage kidney disease. Surprisingly, these deaths are related to many diseases, and this mortality rate motivates us to identify additional risk factors that can be modified to improve survival in patients requiring hemodialysis. Hepatitis virus infection has been associated with many comorbidities other than the liver, such as kidney disease, cardiovascular disease, insulin resistance, diabetes mellitus, and lymphoproliferative disease. Objective: To estimate the hepatitis prevalence in hemodialysis units and assess the risk factors contributing to viral hepatitis infection in hemodialysis centers. Materials and Methods: Cohort study design conducted in dialysis centers-Najaf AL Ashraf\ Iraq , , May 2023. The sample was collected by questionnaire and by referring to patient records to measure the prevalence of viral hepatitis. Results: 72 patients with hepatitis in hemodialysis centers responded to study. Their ages ranged from 20-78 years. The group of participants (41-60 years old) constituted approximately half of sample, and the percentage of sex was males more than females. The prevalence of viral hepatitis was 10.3 %. Among patients with hemodialysis treatment, hepatitis B virus is less than C.

Constraints on co- and cross-polarization reflection and transmission of Babinet-complementary metasurfaces

A study of constraints on reflection and transmission coefficients for Babinet-complementary metasurfaces is presented in this work. These coefficients have been found to describe circular paths in the complex plane, whose centers and radii are affected by losses. Additionally, it has been shown that it is possible to fully control the cross-polarization coefficients by rotating the metasurface with respect to the polarization direction. Our findings have been verified through numerical simulations and experiments. The properties discussed in this paper could be useful in limiting the types of possible responses of metasurfaces.

Decoupled Dipole Arrays Empowered by Invisible Complex Poles in Epsilon‐Near‐Zero Metamaterials

AbstractEvanescent waves, characterized by an exponential decay in propagation, have witnessed significant advancements in far‐field imaging and near‐field sensing applications. However, incoming evanescent waves can excite guided resonance inside a dielectric slab, resulting in a rapid growth of transmission coefficient toward infinity at the pole points. Such evanescent‐wave excited resonance benefits super‐resolution applications yet causes severe crosstalk in highly integrated multi‐channel devices. Here, the invisible complex poles are discovered in the transmission spectra of epsilon‐near‐zero (ENZ) metamaterials and demonstrate the striking suppression of near‐field crosstalk enabled by the anomalous transmission beyond the critical angle. Equipped with an ENZ metamaterial spacer, collinear dipole arrays exhibit 9.2 dB improvement in near‐field isolation among interior dipoles at a distance of less than one wavelength. Experimental measurements show negligible influence on the intrinsic impedance matching and radiation patterns of the dipole antennas. The discovered field divergence effect from the disappearance of real‐valued pole singularity in ENZ metamaterials offers an alternative solution for highly compact arrays in full duplex communication and multiple‐input multiple‐output technology.

La literatura en los manuales de ELE: una propuesta para su análisis

Literature is one of the most valuable teaching resources for language learning. Particularly, teaching ELE permit entire traineeship to Spanish student as a foreign language. It is possible in all skills trainees must achieve and improve. Especially, throughout associated with intercultural competence. In fact, for many years, literature has been part of foreign language books. Consequently, it is essential to review all the topics which book publishers select and incorporated in different ways, both from a qualitative and quantitative point of view. Therefore, the research aim focuses on analyzing literature´s role at ELE to assess aspects such as the place they are located, their integration in the thematic unit, the type of content, the origin of the authors and their genre. In this way, it will be possible to offer a template for the analysis of manuals. After its application on textbooks, it has been verified using texts and literature contents in general becomes irregular, even more so in the elements referring to the origin and gender of the authors. Therefore, results confirm the initial working hypothesis regarding; literature value as a cultural transmission factor, also beliefs at the time where textbooks were made.

Parental Depression Symptoms, Skin Conductance Level Reactivity and Parenting: Associations with Youth Psychopathology.

Parental depression symptoms are a prevalent risk factor for internalizing and externalizing problems in youth, with parenting and parents' physiological stress reactivity representing potential contributing factors in the intergenerational transmission of psychopathology symptoms. In a sample of adolescents (N = 97) and their parents, the current study examined parental depression symptoms, an observational measure of parenting, and parents' physiological reactivity during a dyadic conflict discussion task in association with adolescents' internalizing and externalizing psychopathology. Parental depression symptoms and harsh/insensitive parenting showed positive associations with youth psychopathology symptoms. Further, parental depression symptoms were associated with greater externalizing symptoms in youth, specifically for parents with higher physiological reactivity during the conflict task. The present study highlights risks associated with parental depression and harsh/insensitive parenting, and provides evidence for parental physiological reactivity as a moderator of the association between parent and youth psychopathology. Clinical implications, limitations, and directions for future research are discussed.

A comparative investigation of neutron and gamma radiation interaction properties of zircaloy-2 and zircaloy-4 with consideration of mechanical properties

Abstract This study has established the radiation shielding efficacy of zircaloy-2 and zircaloy-4 over a wide spectrum of energy levels. Using the Monte Carlo N-Particle (MCNP) method, the gamma and neutron transmission factors (TF and nTF) were calculated for various energy levels. Zircaloy-2 demonstrated the highest gamma-ray absorption capacity and the lowest neutron absorption capacity among the investigated alloys. The results indicate that zircaloy-2 and zircaloy-4 have nearly the same neutron transmission characteristics. Although many studies have examined the structure and physical characteristics of these materials, there has been a lack of Monte Carlo simulations to comprehensively investigate the correlation between gamma absorption, neutron absorption parameters, and mechanical qualities. This research aims to examine the ability of zirconium and its zircaloy-2 and zircaloy-4 alloys, which are critical materials used in the nuclear industry, to absorb gamma and neutron radiation over a broad spectrum of frequencies. According to the results, zircaloy-2 has the best ability to absorb secondary gamma rays and the highest level of resistance to them. Despite the minimal disparity in the nTF between the two alloys, simulation results have shown that zircaloy-2 has a higher level of neutron transmittance. These results have the potential to expedite the development of novel materials with enhanced attributes for various applications.

Shock Waves in Nonlinear Transmission Lines

In the first half of the article, interaction between the small amplitude travelling waves (“sound”) and the shock waves in the transmission line containing both nonlinear capacitors and nonlinear inductors is considered. Herein, the “sound” wave coefficient of reflection from (coefficient of transmission through) the shock wave is calculated. These coefficients are expressed in terms of the speeds of the “sound” waves relative to the shock and the wave impedances. In the second half of the article, the dissipation in the system is explicitly included into consideration, introducing Ohmic resistors shunting the inductors and also in series with the capacitors. This allows us to justify the conditions on the shocks, postulated in the first half of the article. This also allows us to describe the shocks as physical objects of finite width and study their profiles, same as the profiles of the waves closely connected with the shocks—the kinks. The profiles of the latter, and in some particular cases, the profiles of the former are obtained in terms of elementary functions.

Analysis of diode mixers using the method of node potentials in generalized matrix form in the frequency domain. Part 2. Isolation between ports, miscondition effect, noise level

A method for theoretical analysis of “input-output” and “local oscillator-output” decouplings of three types of diode frequency converters is presented: balanced, double balanced, triple balanced. For two operating modes of the local oscillator – “non-intensive” and “intensive” – the dependences of the “input-output” decoupling of the balanced mixer on the load conductivity and on the amplitude of the local oscillator voltage were obtained. Theoretical analysis and modeling were carried out. It is shown that the error between the calculated results and the simulation results does not exceed 3 dB. Expressions are obtained for errors introduced by the technological spread of diode parameters, which make it possible to estimate the maximum achievable values of the mixer characteristics (transmission coefficient and port isolation). A method for analyzing the noise properties of mixers is presented, the output noise spectra are calculated for each of the circuit elements (input resistance, diodes and output resistance), and analytical expressions for noise coefficients are obtained. Theoretical noise figure estimates are confirmed by simulation results with an accuracy of 1 dB.

Research of the efficiency of Kravchenko weighting functions and combinations based on them in the problem of narrow band interference rejection

The influence of weight functions (WFs) of preliminary weighting on the quality of narrowband interference rejection based on direct and inverse discrete Fourier transforms has been studied. Classical and modern WFs are considered: Kravchenko, Kravchenko–Dolph–Chebyshev, Kravchenko–Gauss, Kravchenko–Bernstein–Rogozinsky. Quantitative estimates of efficiency were obtained – the coefficients of interference suppression and signal transmission, as well as their product – the total efficiency coefficient. Graphic examples of the behavior of the total efficiency coefficient depending on the interference frequency are shown. Estimates of the indicated quality indicators are presented when a fixed number of frequency samples are removed from the spectrum. The families of dependences of the probabilities of correctly performing a search for a spread spectrum signal on the “interference/signal” ratio when using modern WFs to weigh the implementations of an additive mixture of signal, interference and noise are presented. The significant advantage of modern WFs formed through combinations with Kravchenko functions in the problem of interference rejection has been demonstrated and confirmed.

Broadband low-transmission study of ventilation metasurfaces based on Archimedean spirals

The primary objectives of acoustic material design include ensuring indoor ventilation and isolating external noise. This study introduces a ventilation metamaterial surface based on Archimedean spirals (ASVM) and calculates its energy transmission coefficient using simulation and the Transfer Matrix Method (TMM). Experimental validation confirms the accuracy of the proposed model, highlighting ASVM’s potential as an effective ventilation metamaterial surface. Subsequently, ASVM is integrated with Helmholtz resonators (HR) to create two new metasurfaces: HR-ASVM without a neck and N-HR-ASVM with a neck. The former exhibits a power transmission coefficient below 0.2 across the broadband range of 1300 Hz to 2500 Hz, while the latter demonstrates superior sound insulation performance (power transmission coefficient below 0.1) from 639 Hz to 2500 Hz, with complete transmission suppression at 710 Hz. Notably, the thickness of N-HR-ASVM at this frequency is only 1/13 of the wavelength. Simulations of the acoustic pressure field and energy flow analyze the mechanisms responsible for low transmission. Finally, the energy transmission coefficient of N-HR-ASVM is experimentally measured and found to align closely with simulation results. This study provides valuable insights into the research on spiral ventilation metamaterial surfaces.