Minimum Height Research Articles

A Novel Rotor Type Wave Energy Converter Design for Maximum Energy Captured in Low Wave Heights

Wave energy converter system (WEC) is generally used by obtaining of electrical energy. Maximise power capture is needed a range of sea-states. Continuity is improved to control of power take off. But wave energy have o lower force and a higher speed in onhore. Therfore, this paper is investigated the novel rotor type wave energy converter performance in this wave suitable conditional. The performance of this system is tested in laboratory condiotions.This aim of design is maximum power absorption from low wave height of waves. Results show that the higher wave height has caused the efficiency to decrease in all periods. The highest efficiency is obtained at a minimum wave height of 2 cm. At this wave height, the efficiency has reached its highest value when the period is 5 s (20.3%). In this case, it makes this prototype suitable for seas with low wave height and high wave period.

Recommended procedure for headroom design according to geometric parameters of building structures

The system of Czech technical standards for geometric accuracy assumes that the designer determines the functional geometric parameters for a specific building. By calculation, he verifies them in the so-called “geometric plan” in the project documentation. The functional geometric parameters should be determined primarily for critical elements, i.e. for structures whose geometric accuracy is important for the execution of subsequent works, such as technologies requiring high precision and specific structures. The assumption is that designers will incorporate variations in geometric accuracy primarily in the development of the spatial parameters of the structures, which should ensure that the dimensional requirements for the completed structures will be met. One of these parameters is headroom. The design of headroom must respect the minimum height requirements prescribed by legislation, and where appropriate, by technical standards. At the same time, the design must respect the technological possibilities of the construction of individual structures – geometric deviations. To comply with the dimensional requirements for the completed structures, the geometric accuracy deviations should be determined in accordance with the requirements of the technical standards for the execution of the individual parts of the building structures and/or for their design. The aim of this article is to establish a calculation procedure for determining the safe design clearance so that the requirements of the legislation are met after implementation. The increase is determined based on a calculation procedure of the limiting geometric deviations that may affect the resulting headroom.

Appraisement of the P-Delta Effects in Multi-Storey Reinforced Concrete Buildings Influenced by Seismic Load

Population increment encourages engineers to build high-rise structures. However, in high-rise structures lateral load has a more severe impact on the structure than axial loads and this effect is known as the P-Delta effect. The current study aims to evaluate P-Delta effects in a high-rise structure located in Kabul city and to pinpoint the minimum height required for considering P-Delta effects in structural analysis. The analysis is carried out utilizing the response spectrum method performed by ETABS software for a total of five models with a different number of storey and lateral load-resisting systems. It is observed that with the increase in lateral stiffness, P-Delta effects can be minimized to a certain extent. Lateral displacement, storey drift, and stability coefficient are some of the other parameters considered for comparison purposes which are significantly mitigated while a shear wall is provided. Also, an adequate and proper positioning of shear walls has resulted in an appropriate solution for minimizing the P-Delta effects. Keywords: P-Delta effect, Lateral displacement, Lateral stiffness, Stability coefficient.

Optimization of a combined tanker/platform type vessel based on simulation modeling

The choice of the height of the side of a cargo vessel, as a rule, is carried out on the basis of solving the equation of cargo capacity, while the remaining requirements for its size act as restrictions. However, if the ratios of the main dimensions and the requirements for the minimum freeboard height are somewhat conditional, then ensuring seaworthiness, which, in addition to capacity, when choosing the side height, should include unsinkability, requires high-quality accounting. The article presents a mathematical model for assigning the freeboard height, taking into account the requirements of the Rules of the Russian Classification Society for checking the landing and stability during flooding of one or several adjacent regulated compartments; an analysis of the effect on the height of the side of flooding of various compartments of an oil tanker of mixed (river-sea) navigation is carried out and an approximate formula for calculating it at the initial stages of design is proposed.

Submarine groundwater discharge in response to the construction of subsurface physical barriers in coastal aquifers

Submarine groundwater discharge (SGD) is an important component of the local and regional hydrologic cycles, affecting coastal water quality and ecology. However, the influence of subsurface physical barriers widely built in coastal aquifers for seawater intrusion control has not yet been fully understood with respect to the downstream SGD. In this study, we used both laboratory experiments and numerical simulations to quantify the contribution of subsurface physical barriers to the fresh and saline SGD fluxes. Different types of physical barriers, including cutoff wall and subsurface dam, were examined with various structures (e.g., barrier location, height, or penetration depth). The results demonstrated that subsurface physical barriers with different structures resulted in various changes in the location of the freshwater discharge at the aquifer-sea interface, e.g., the discharge location shifted seaward as the cutoff wall moved inland. The water exchange across the aquifer-sea interface was closely related to the structure of subsurface physical barriers. With the increase in the height of subsurface dam or the increase in the depth of cutoff wall, the fresh and saline SGD fluxes revealed a decreasing trend. Generally, the presence of a physical barrier hindered the hydraulic connection between the upstream and downstream aquifers, and the SGD fluxes were reduced compared to those without any barrier. For cutoff walls, the change in wall depths led to decreases in tide-induced saltwater circulation of 25%–33%, density-driven saltwater circulation of 10%–30%, fresh groundwater discharge of 17%–60%, and the total efflux of 18%–36%. Within the effective height range of the subsurface dam, fresh and saline SGD fluxes peaked at the minimum effective height. These findings provide a general framework for the prediction and monitoring of SGD behavior in coastal aquifers where subsurface physical barriers are intended or have been constructed.

Glenoid cavity morphometric study in human scapula

Relevance. Scapula is one of the bones that takes part in the formation of shoulder joint and has variable morphology. It is weak joint because glenoid cavity is variable in vertical diameter and transverse diameter. Hence glenoid cavity is shallow and gives rise to frequent dislocation of shoulder joint. Aim of the present study was to know various dimensions of glenoid cavity like vertical diameter and horizontal diameter and their variations in percentages. Materials and Methods. Fifty unknown dry human scapulae from the department of anatomy (Mahatma Gandhi Medical College, Sitapura, Jaipur, Rajasthan, India) constituted the materials for the present study. Each scapula was studied for glenoid cavity. The vertical diameter and horizontal diameters were studied from each above scapula. Twenty five scapulae were from right side and twenty five were from left side. The different shapes of glenoid cavity were observed. The shapes were pear shaped, inverted comma shaped and oval shaped. Results and Discussion. In the present study pear shaped glenoid cavity was found in 56 %, Inverted comma shape was found in 26 % and oval shape was observed in 18 %. The most common shape was pear shape (56 %) and least common shape was oval shape (18 %). The mean glenoid height was 35.52 mm. The maximum glenoid height was 41.22 mm and minimum glenoid height was 30.19 mm. The mean glenoid width was 20.77 mm. The maximum glenoid width was 24.31 mm and minimum glenoid width was 17.93 mm. Conclusion. Study showed that glenoid cavity has varied morphology. This varied morphology will be of great useful in various clinical and surgical procedures like hip replacement and in posterior glenoid osteotomy.

Computed Tomographic Evaluation of Mandibular Ramus for Gender Identification

Background: The ability to identify sex is essential for identification and plays a significant role in forensic medicine and medico legal investigations. Identification's first purpose is sex determination, which is followed by estimations of age, size, and ethnic population, all of which are influenced by the gender. When identifying morphologic characteristics for gender determination, gender analysis and estimate are carried out with almost 90% to 100% accuracy using a whole skeleton. On the other hand, partial or fragmented bones and badly injured bodies, such as in the case of a mass tragedy, might be challenging to analyse. The skull is the second-best marker for gender identification after the pelvis. However, as the mandible is the biggest bone of the skull, it may be crucial in circumstances when a whole skull is not recovered for gender identification. Objectives: To ascertain how computed tomography can be utilised to know a person's gender with the help of mandibular measurements. Methods: The study was done with the Siemens Somatom 16 slice CT machine. Patients who match the inclusion criteria and have received CT for a wide range of reasons will be considered. Various measurements such as Condylar height, Maximum ramus breadth, Minimum ramus breadth projective height of ramus, Coronoid height shall be measured. Data analysis must be done with SPSS 20. For comparisons between the right and left sides, the student t-test shall be applied. Results: 58 individuals between the ages of 18 and 35 (29 females, mean age, 26.3, 29 males, men age, 26.9 & overall mean for both sexes was 26.6 years). In the present study, mean score of five distinct mandibular parameters were calculated. All mandibular ramus variables on CT models were discovered to exhibit a statistically significant gender difference (p = 0.001). It was discovered that the mean condylar height was 64.5 mm in men and 59.56 mm in women, which was a significant (P = 0.001). It was noteworthy (P = 0.001) that whereas the mean maximal ramus width was 35.0 mm in females and 38.0 mm in men. Males and females had different mean values for the minimum ramus width, which were 31.3 mm and 28.8 mm, respectively (P = 0.001). Males and females had mean ramus projection height measurements of 52.38 mm and 47.91 mm, respectively. This difference was significant (P = 0.004). The mean coronoid height was 63.42 mm in men and 56.80 mm in women, which was significant (P = 0.001). 27 out of 29 female mandibular measures correctly identified the gender, with a prediction rate of 96.4%, and 27 out of 29 male mandibular measurements correctly identified the gender, with a prediction rate of 96.4%. The threshold for determining a per- son's sex. As a cut-off for predicting male sex, values over 62.8 mm for condylar height, 36.9 mm for maximum ramus height, 30.0 mm for lowest ramus height, 50.4 mm for projective ramus height, and 61.3 mm for coronoid height can be used. Conclusion: In forensic medicine, the assessment of mandible, particularly the ramus area, plays a crucial factor in determining gender. Future research should evaluate gender determination recommendations using various criteria in bigger sample sizes and across a range of age groups. Although there are differences in ramus measurements between both the genders, there are variations in measures between societies. Therefore, to accurately identify gender from skeletal remains, criteria that are unique to each population must be developed. We think the results of this study will be helpful to radiologists making diagnoses and surgeons working on the mandible and facial area. Keywords: Mandible, Determination of gender, Paranasal sinuses

Features of the technological calculation of the inlet separation plant with preliminary water discharge

To ensure efficient separation of oil production wells with a high content of associated petroleum gas, inlet separation units are used, consisting of an inlet separator, which ensures the separation of the main amount of free gas from liquid, an oil and gas separator, in which free gas is finally separated from the liquid, and a separator-drop catcher, designed to prevent entrainment of droplet liquid with gas. When a gas-water-oil mixture with a high water content enters the plant, an oil and gas water separator can be used instead of an oil and gas separator, which makes it possible to carry out a preliminary discharge of water simultaneously with degassing. The article considers the technology of separation and preliminary discharge of water for oils with high gas content and proposes a variant using heating of a partially degassed liquid. Empirical dependences of the minimum height of the liquid column above the oil and gas separator (gas and water separator) depending on the viscosity and density of the liquid are given. A technique for technological calculation of the mutual arrangement of apparatuses has been developed, the possibility of using heat exchangers as part of the installation has been shown.

The Influence of Cell Phone Usage on Dynamic Stability of the Body During Walking.

Dual-task walking and cell phone usage, which is associated with high cognitive load and reduced situational awareness, can increase risk of a collision, a fall event, or death. The objective of this study was to quantify the effect of dual-task cell phone talking, texting, and reading while walking on spatiotemporal gait parameters; minimum foot clearance; and dynamic stability of the lower limb joints, trunk, and head. Nineteen healthy male participants walked on an instrumented treadmill at their self-selected speed as well as walking while simultaneously (1)reading on a cell phone, (2)texting, and (3)talking on a cell phone. Gait analyses were performed using an optical motion analysis system, and dynamic stability was calculated using the Maximum Lyapunov Exponent. Dual-task cell phone usage had a significant destabilizing influence on the lower limb joints during walking. Cell phone talking while walking significantly increased step width and length and decreased minimum foot clearance height (P < .05). The findings suggest that dual-task walking and cell phone conversation may present a greater risk of a fall event than texting or reading. This may be due to the requirements for more rapid information processing and cognitive demand at the expense of motor control of joint stability.

Composition and community structure of mangroves distributed on the east coast of Marajó Island, Brazil

The present study aimed to determine the composition and structure of the fringe and inland mangroves near the mouth of the Amazon River in Marajó Island. We established five study sites and, in each site, we established a fringe zone and an inland zone. In each zone, we delimited five 400-m2 plots, and we selected arboreal individuals with a minimum height of 1 m. The individuals were grouped into diameter and height classes and basal area, and we analyzed five phytosociological parameters. The composition, richness, density, diversity and dendrogram analysis used were compared between the sampled fringe and inland zones. In our exploration, 344 individuals were recorded, distributed in 10 species, suggesting that Marajó Island has one of the most diverse mangrove forests ever recorded in the world. We also recorded three typical species of mangrove, namely, Rhizophora racemosa, Avicennia germinans, and Laguncularia racemosa. We also observed that the Marajó mangroves have species that occur in other ecosystems (e.g., várzea and igapós), such as Paeonia officinalis, Phalaris aquatica, and Virola surinamensis. We observed that no significant variation between zones was found in terms of richness and density. The NMDS explained variance of 95.3% but no clear pattern of dissimilarity was observed between fringe and inland. In cluster analysis, four groups were statistically well supported, with an explanation of 85% on the dendrogram. These characteristics are important for conservation policies and specific management plans for the mangroves in Salvaterra, since, just as the vegetation is unique in this region.

Forming quality optimization and microstructure analysis of multilayer coatings with laser powder-fed additive manufacturing

To clarify the parameters interaction effects and improve the forming quality of Fe-Cr alloy multilayer laser powder-fed additive manufacturing (LPF-AM) on AISI 4340 substrate, experimental research for Fe-Cr alloy multilayer LPF-AM was carried out via the response surface method (RSM). The interaction effects and evolution rules of laser energy density ( E), powder feed rate ( Q), and Z-axis increment ( h) on minimum cladding height, deposition efficiency and surface spheroidization defects were discussed. The multiobjective particle filter resampling particle swarm optimization (MORPSO) algorithm was adopted to optimize the processing parameters. The phase transformation, grain growth, and microhardness of multilayer LPF-AM were analyzed. The results showed that the powder feed rate and Z-axis increment were found to affect the minimum cladding height and deposition efficiency, respectively. Laser energy density played an essential role in spheroidization defects. The forming quality was significantly improved based on the optimal process parameters of E = 33 J/mm2, Q = 0.5 g/s, and h = 0.8 mm. The primary and secondary remelting zones are fine equiaxed dendrites and irregular cellular structures, respectively, and the microstructure of the cladding tracks and layers showed a good metallurgical bonding. The microhardness of the cladding layer ranged from 321 ± 18 to 625 ± 24 HV0.5, and the average microhardness is twice that of the AISI 4340 substrate.

Anastomotic Rings and Inflammation Values as Biomarkers for Leakage of Stapled Circular Colorectal Anastomoses.

Reliable markers to predict or diagnose anastomotic leakage (AL) of stapled circular anastomoses following colorectal resections are an important clinical need. Here, we aim to quantitatively investigate the morphology of anastomotic rings as an early available prognostic marker for AL and compare them to established inflammatory markers. We perform a prospective single-center cohort study, including patients undergoing stapled circular anastomosis between August 2020 and August 2021. The predictive value of the anastomotic ring configuration and the neutrophil-to-lymphocyte ratio (NLR) regarding anastomotic leakage is examined by ROC analyses and compared to the C-reactive protein (CRP) as an established marker. We included 204 patients, of which 19 suffered from anastomotic leakage (LEAK group), while in 185 patients the anastomoses healed well (HEAL group). The minimal height of the anastomotic rings as a binary classifier had a good ROC-AUC of 0.81 but was inferior to the NLR at postoperative day (POD) 5, with an excellent ROC-AUC of 0.93. Still, it was superior to the NLR at POD 3 (0.74) and the CRP at POD 3 (ROC-AUC 0.54) and 5 (ROC-AUC 0.70). The minimal height of the anastomotic rings as indicator for technically insufficient anastomoses is a good predictor of AL, while postoperatively the NLR was superior to the CRP in prediction of AL.

Surveying the effects of concave obstacles with different edge walls on hollow glycerin droplet impacting using the volume of fluid approach

The numerical analysis of the impact of a hollow droplet on a solid concave obstacle at various heights of the edge wall and impact velocity is presented in this study. The Volume Of Fluid (VOF) approach was used to simulate hollow droplet impact using OpenFoam software. The Newtonian, incompressible, and laminar properties of the glycerin hollow droplet are assumed. Hollow droplet collision hydrodynamic behavior and jet characteristics were explored. The height of the counter jet rose as the impact velocity and height of the edge wall increased. Maximum height and length have happened to case 8 in t = 2 ms and case 3 in t = 1 ms, so the amount of it is 9.75 and 19.75 mm, minimum height and length in the last time computed is 1.4 and 2.73 mm for cases 1 and 7, respectively.

Safety Analysis of a Nuclear Power Plant against Unexpected Tsunamis

The East Sea (Sea of Japan), surrounded by Korea, Japan, and Russia, is highly vulnerable to catastrophic tsunamis. Several nuclear power plants (NPPs) operate along the eastern coast of Korea and several more are under construction. Unexpected tsunamis can affect these power plants. The safety of NPPs has attracted worldwide attention since the Fukushima NPP accident. In this study, a coupled numerical model comprising propagation and run-up models was employed to investigate the safety of an NPP against unexpected tsunami attacks. The maximum and minimum tsunami heights and arrival times of the leading tsunami were numerically predicted to ensure the safety of the Uljin NPP, where six plants are already operational and two more are under construction. The predicted numerical results were compared with the safety guidelines proposed by relevant authorities. These results indicate that NPPs are reasonably safe from unexpected tsunamis. Additionally, we confirmed that the tsunami heights and arrival times of a leading tsunami becomes smaller and delayed as the latitude of the epicenter increased.

Individual tree detection from unmanned aerial vehicle (UAV) derived point cloud data in a mixed broadleaf forest using hierarchical graph approach

ABSTRACT Studying individual trees is a common way that scientists employ to study forests and estimate forest parameters. In this study, a graph-based approach was developed for detecting individual trees in a broadleaf, complex forest region based on UAV-derived point cloud data. Horizontal cross-sections at different heights were applied to the Canopy Height Model (CHM) to extract initial candidates for graph nodes. The graph was processed in multiple steps, and individual treetop locations were detected based on graph nodes’ properties. The impact of various parameters, such as minimum area of connected components and minimum tree heights, on the performance of the developed method was investigated. The evaluation step demonstrated the potential of the proposed graph-based method for individual tree detection in a complex forest region in Mazandaran, Iran. In particular, the graph-based method obtained Precision, Recall, and F1-score values of 0.64, 0.73, and 0.68, respectively. Furthermore, the intercomparison with the well-known and most used Local Maximum (LM) suggested the applicability of the proposed method. After point cloud generation, the proposed method was implemented entirely in Python using open-source packages, which increases its applicability for other scholars and managers. The source code of the proposed algorithm can be found at https://github.com/Seyed-Ali-Ahmadi/Graph-based_ITCD.

Stability Influencing Factors and Control Methods of Residual Coal Pillars with Solid Waste Materials Backfilling Method

Affected by coal mining activities, the remaining coal pillars are very likely to be destabilized and cause safety accidents. The backfilling of the remaining goaf can maintain the stability of the coal pillar well, but the coal pillar in the unfilled zone may still be unstable. In this paper, the effect of backfilling materials on coal pillars and the reinforcement method are discussed using numerical simulation, statistical mathematics, elastic mechanics, and mechanical test methods. The results show that: backfilling with solid waste materials and reinforcing the coal pillar could maintain the stability of the bottom goaf, where the backfill body height is the main factor in the strength of the coal pillar. The propagation of the confining stress of the backfill body on the pillar in the unfilled zone is the primary way to influence the coal pillar strength. Changing the backfill body height filling can affect the coal pillar strength. By analyzing the propagation law of confining stress in the coal pillar, the minimum backfill body height is determined to be 7 m. Combined with mechanical tests and the Mohr–Coulomb criterion, the minimum confining pressure required to maintain the coal pillar stability under the peak ground pressure is analyzed. The ratio of solid waste materials is determined based on this. Field tests have proved that the coal pillar remains stable when the goaf is not filled, and the cement/fly ash ratio is 1:4, which can ensure product safety. The research has significant value and significance for the governance of the remaining coal pillars and production safety.

P-073 THE MODIFIED SUBLAY TECHNIQUE FOR THE MANAGEMENT OF MAJOR SUBCOSTAL INCISIONAL HERNIA: LONG-TERM FOLLOW-UP RESULTS OF 41 CONSECUTIVE PATIENTS

Abstract Aim To present the concept of original technique in the management of major incisional subcostal hernias bassed on sublay position of large haevy-weight polypropylene mesh between the two myofascial layers in the anterolateral abdominal wall. Material and methods Between January 2010 and May 2022, 41 consecutive patients underwent the modified sublay technique for major incisional subcostal hernia (minimal defect surface100 cm2 or minimal defect width or height 10 cm). The operative technique is: a) hernia sac dissetion and reposition into the abdominal cavity; b) rectus muscle and rectus muscle stump dissection from posterior rectus sheath, rectus muscle atachement dissection from thoracic wall and external oblique muscle dissection from internal oblique muscle around hernia defect at the side of the hernia defect; c) separate posterior and anterior rectus sheaths reconstruction at the midline; d) reconstruction of the posterior miofascial layer suturing internal oblique/transversal muscle and posterior rectus sheaths; e) large haevy-weight polypropilene mesh placement between posterior and anterior miofascial layer; e) reconstruction of the anterior miofascial layer by suturing external oblique muscle and anterior rectus sheaths. Results A median (range) hernia defect surface was 160 (100–500) cm2. A median operative time was 120 (90–330) minutes. The morbidity rate was 19.5%. A median (range) postoperative hospital stay was 7 (2–24) days. After the median follow-up of 50 (1–124) months, two patients (4,9%) developed recurrent hernia. Conclusions The modified sublay technique using large heavyweight polypropylene mesh provides good results in the management of major subcostal abdominal wall defects.

Die dimensions impact on fibrous plant protein formation during high moisture extrusion

Plant-based meat analogues that mimic the structure and texture of meat are becoming very popular. They can be produced using high moisture extrusion (HSE). . High protein materials first undergo intense thermomechanical treatment in the extruder barrel and then are textured and simultaneously cooled in the die. The mechanisms underlying this structuring process are not sufficiently understood and depend on numerous and interconnected factors, including raw materials composition and process parameters. This study focuses on the effects of die height and die length on extruder responses (torque, pressure), textural properties and fibration of soy concentrate extrudate obtained at high moisture (60% w/w). In order to evaluation the quality of fibration, and to complete texture analysis, a visual method base on angle of fibration was developed. By comparing extrudate obtained with die of 2 mm and 5 mm height, this study shows that a minimum height is necessary for temperature gradient and velocity profile creation in the die. In order to study die length higher than the one observed in the literature, a modular die with different lengths was specially developed for this study, going from 150 to 600 mm for a extrusion barrel length of 640 mm. Results show a linear correlation between fibration and die length: the longer is the die, the more elongated is the internal flow pattern. This change in flow pattern leads to an improvement in the quality of the extrudate fibration.It confirms that die length is one of the main influencing factor for fiber formation, and that a minimum length is required to obtain extrudats which structure really mimics meat fibres.

Bed expansion at backwashing in pressurised porous media filters for drip irrigation: Numerical simulations and analytical equations

Actions for improving the energy efficiency of pressurised porous media filters used in drip micro-irrigation require methods to properly determine the behaviour of both filtration and backwashing modes. The latter is essentially a fluidisation process. Though many authors have analysed fluidised bed columns, very few studies have dealt with the backwashing of granular media filters used in agriculture. The purpose of the present work was 1) to validate a computational fluid dynamics (CFD) model to simulate the backwashing regime, and 2) to assess the extent of analytical expressions for determining the expanded bed height. Experimental data were obtained using a laboratory filter for two types of porous media at superficial velocities <150 m h −1 . The CFD model used the Eulerian–Eulerian approach, and its sensitivity was investigated in a simplified two-dimensional domain. A modified three-dimensional model effectively reproduced the bed expansion for most of the experimental conditions using large time steps (0.025 s) and few internal iterations (20). Well-known analytical equations overestimated the expanded bed height at superficial velocities <150 m h −1 , but the recent RIO 1 model proposed by Kramer et al. (2020) showed very good predictive capacities. Two analytical expressions based on basic principles were developed, providing a trend which was also close to observations and a lower bound for the expanded bed height value. These conclusions were confirmed by analysing external data obtained using commercial pressurised sand filters. • The backwashing mode of a pressurised granular media filter was investigated. • The CFD model reproduced the fluidised bed behavior for superficial velocities <150 m h −1 . • The set-up of the CFD model required a case-by-case analysis. • A new analytical equation to determine the expanded bed height was obtained. • An equation to estimate the minimum expanded bed height was developed.

Дослідження характеристик резонансної системи на основі прямокутного хвилеводу з двома діафрагмами

Microwave methods for the study and control of the dielectric properties of substances using regular and irregular rectangular metal waveguides have many applications and are of great practical interest. The dielectric properties of materials are assessed based on the determination of the reflection and transmission coefficients in a resonant system. This article considers resonant phenomena of electromagnetic oscillations in a prismatic cavity based on a length of a rectangular waveguide with two diaphragms and with a dielectric specimen in the form of a cylinder centrally positioned between them. The goal of this work is to evaluate the resonant properties of a prismatic cavity based on a length of a rectangular waveguide with two diaphragms as a function of the geometrical dimensions of the rectangular diaphragm windows, the distance between the diaphragms, and the dimensions and dielectric properties of the specimen located at the center of the waveguide length. By computer simulation, the resonant properties of the system were determined as a function of the dielectric constant and diameter of the specimen and the geometrical dimensions of the diaphragm windows. It was found that for each value of the specimen diameter there exists a maximum allowable value of the dielectric constant at which the resonant properties of the system are kept in a selected operating frequency range. The effect of the height of the diaphragm windows on the resonant frequency of a prismatic cavity and the reflection and transmission coefficients was studied, and the behavior of the intrinsic Q factor was assessed qualitatively. A minimum possible diaphragm window height was found such that both the required coupling between the rectangular cavity and the external microwave line is provided and the maximum value of the loaded Q factor in the absence of a dielectric specimen is kept. The results of this work may be used in the design of high-frequency sensors for controlling the dielectric properties of materials in various industries.