Flat Type Research Articles

Flat breads qualities and attributes — ovens design, energy consumption, and environmental conservation: A review

Flat bread is considered a staple food worldwide and especially balady bread in Egypt and the Middle East region. The most common flat bread types produced all over the world, contents, used leavening agents, properties, and countries were reviewed. Also, balady bread ingredients, formula, preparation, dough rheology, baking conditions, as well as physical characteristics, color attributes, sensory evaluation, and freshness or staling retardation of loaves were presented. Flat bread (balady bread) is processed from attened dough of wheat our, sodium chloride, water, and yeast and is often served freshly baked and produced in both bakeries and homes. The main features of a balady bread oven, such as composition, construction, dimensions, fuels, emissions, and its effect on the environment and energy consumption, were also mentioned. The common specifications and general design of a balady bread industry oven in Egypt on a commercial scale were presented as follows: Oven length could be more or less than 600 cm depending on available space in the baking building. Also, oven width could be more or less than 90 cm, depending on the needed productivity of bread per hour. To “keep the environment, minimize heat losses, maximize quantity and quality of production, and assure economic visibility,” the determination of oven dimensions, selecting construction materials and transmission systems must be done by oven designers using the oven general model.

Impact of Preoperative Lacrimal Sac Morphology on Postoperative Rhinostomy Shape and Prognosis in Endoscopic Dacryocystorhinostomy

Purpose: To determine the association between the preoperative shape of the lacrimal sac and the postoperative shape of a rhinostomy in patients undergoing endoscopic dacryocystorhinostomy (DCR) for primary acquired nasolacrimal duct obstruction. Material and Methods: This retrospective study involved 180 cases among 129 patients. Preoperative dacryocystography (DCG) classified lacrimal sacs into constricted or cylindrical types based on their width relative to the nasolacrimal duct. Postoperative rhinostomy shapes were categorized into flat, ladle, and ice-scoop types according to the presence and visibility of borders between the lacrimal sac and nasal mucosa. Anatomic success required patency as verified by syringing, whereas functional success required the complete resolution of epiphora. Results: The 180 cases comprised 46 (25.7%) and 134 (74.3%) classified as constricted and cylindrical preoperative shapes, respectively. There were 24 flat, 92 ladle, and 64 ice-scoop types of rhinostomies observed postoperatively. The preoperative DCG shape influenced the postoperative rhinostomy shape, with constricted sacs more frequently resulting in flat-shaped rhinostomies, and cylindrical sacs more frequently resulting in ice-scoop-shaped rhinostomies. Functional success was more common in cylindrical and ladle-type sacs than in constricted types (P<0.001), and lower for flat-shaped rhinostomy than for the ladle and ice-scoop shapes (P=0.003). Conclusions: Lacrimal sac characteristics play a prominent role in determining the postoperative rhinostomy shape that is particularly relevant to functional outcomes. A preoperative cylindrical lacrimal sac and postoperative ice-scoop-shaped rhinostomy are predictive of functional success after endoscopic DCR. These observations will be crucial in creating a surgical plan and monitoring the postoperative rhinostomy configuration.

A morphology of the distal medial femoral surface that should be considered when performing coronal osteotomy in medial closed wedge distal femoral varus osteotomy.

The aim of the present study was to evaluate the morphology of the distal medial femoral surface during coronal osteotomy in medial closed wedge distal femoral varus osteotomy (MCWDFO) using plain CT. Twenty knees (mean age, 55.3years) were included. Preoperative CT images were obtained prior to MCWDFO for valgus OA. In the cross-section depicting the starting position of the transverse cut, a curve was drawn that passed through the centre of the femoral cortex, and lines parallel and perpendicular to the surgical epicondylar axis (SEA) were drawn to analyse the medial side. Inflection points on the medial line were defined as P1-P4. The radii of circles passing through P1-P3 (PR, posterior radius) and P2-P4 (AR, anterior radius) were drawn. Values for the PR, AR, and radius ratio (PR/AR) were measured. Based on the PR/AR, the cross-sectional morphologies were classified into 5 triangular types (PR/AR < 0.5), 4 flat types (PR/AR > 0.8), and 11 convex types (PR/AR 0.6 to 0.7). The medial anteroposterior width and flange thickness were easier to assess in the flat type; however, these were difficult to assess in the triangular type with a gentle anterior slope. Surgeons should consider the differences in the anterior slope according to cross-sectional morphologies when performing coronal osteotomy in MCWDFO.

On proper motions of the flat cosserat type structure

The problem of natural vibrations of a flat strip of anisotropic two-dimensional Cosserat medium under the assumption of small deformations and in the absence of external forces and moments is investigated. It is shown that two natural frequencies correspond to each wave number. The natural forms of oscillations and the relationship between them are found. It is concluded that at oscillations with the lower of the two frequencies the inclusion rotations accompany the longitudinal displacement of the strip, and at oscillations with a higher frequency they prevent it. The obtained results are illustrated on the example of a medium model with specific parameter values. The plots show the dependences of natural frequencies, phase and group velocities on the wave number, and their asymptotic behavior is studied.

3D morphometric analysis of the epiglottis using CBCT: age and gender differences

BackgroundThis study aimed to perform a comprehensive morphometric analysis of the epiglottis using cone-beam computed tomography (CBCT) images, including the determination of epiglottis dimensions, the investigation of shape variations, and the assessment of their relationship with gender and age.MethodsA retrospective analysis was conducted on high-quality CBCT images from 100 patients, obtained using the NewTom 5G system. In CBCT images, epiglottis thicknesses (right, midline, left) and horizontal angle at three levels (suprahyoid, hyoid, infrahyoid) were measured in axial sections, while the length and vertical angle of epiglottis were measured in midsagittal view. Epiglottis shapes were identified through 3D visualization.ResultsThe midline epiglottis thicknesses were 4.68 mm at the suprahyoid level, 5.51 mm at the hyoid level, and 6.80 mm at the infrahyoid levels. Epiglottis thicknesses and length were statistically significantly greater in males. Of the 100 patients, 51 had a normal curvature, 41 had a flat epiglottis, and 8 had an omega epiglottis. The omega-shaped epiglottis was significantly longer compared to both the flat and normal curvature types (p = 0.011). There was a positive correlation between age and epiglottis thicknesses at the suprahyoid level and horizontal angles at three levels.ConclusionsThis study visualizes epiglottis morphology and uncovers significant morphometric differences. Males exhibit greater epiglottis thickness and length compared to females, while the omega-shaped epiglottis is notably longer than other types. These findings underscore the need for further investigation into the clinical relevance of these morphometric differences, particularly in improving airway management and refining approaches to swallowing function.

The Impact of CO2 Dynamics within the Gas Diffusion Electrode on Electrochemical CO2 Reduction in Zero-Gap MEA Operation

Since the Industrial Revolution, massive amounts of generated from human industrial activities have been causing ongoing climate change and environmental impacts on Earth. Hence, there is a substantial body of research aimed at mitigating CO2 emissions to address climate change. Research on CO2 reduction has been actively conducted, focusing on electrochemical-based CO2 conversion capable of operating under high current and long-term conditions. Under high current and prolonged operation, catalyst are influenced by the concentration of CO2 within the catalytic layer. To investigate the impact of CO2 concentration, we fabricated reaction zones of flow plates used in zero-gap MEA electrolyzers in both flat and sunken shapes. The two flow plates feature an inlet with a channel to guide the incoming gas to the reaction zone and a channel within the reaction zone to distribute the gas effectively. Both the flat and sunken type feature. Both the flat and sunken shapes contain a reaction zone channel where the gas diffusion layer (GDL) is positioned at the top. However, In the sunken flow plate, gas introduced from the inlet can penetrate towards the GDL side, facilitating enhanced delivery of CO2 to the catalytic layer compared to flat flow plates. This leads to increased CO2 activity within the catalytic layer and, simultaneously, offers the advantage of easier water management, a major cause of equipment performance degradation. In this study, we confirm through simulation that the sunken shape in flow plates with serpentine channels in the reaction zone offers advantages in CO2 activity. Experimentally, we obtained partial current densities of 861 mA/cm2 and 1 A/cm2 for silver catalyst and NiNC catalyst, respectively, in the sunken serpentine structure. To analyze the reasons for the increase in these values, which are 34.5% and 18.3% higher respectively compared to the flat serpentine structure, we conducted device water discharge experiments and real-time CT imaging. Through this, we confirmed that water management is more efficient in the sunken serpentine structure. The insights and methods presented in this research are crucial for developing design principles suitable for large-scale industrial electrochemical CO2 electrolysis. Figure 1

Experimental Determination of a Mixture Composed of Camisea Natural Gas and CO2 Laminar Burning Velocity

The aim of this work is to provide new experimental data on laminar burning velocities for a new synthetic mixture composed of Camisea natural gas and CO2. It was found that the relevant published experimental background data are limited to mixtures composed of methane and CO2; considering the fact that Camisea natural gas is widely used in Peru, this experimental research will serve as a supportive resource for further experimental and industrial implementations in this country, such as the design and modeling of new engines or industrial burners that are designed to be fueled by this mixture. An experimental setup for analyzing three types of flame geometry, which is feasible to implement for a wide range of conditions, was built in PUCP PI0735 laboratory and all the measurements were obtained for a range of mixtures (0%, 21.2%, 28.5%, 38.9%, 50% CO2) and ratios from around 0.55 to 0.95 at atmospheric conditions. The laminar burning velocities results obtained were analyzed in groups based on %CO2. In addition, the experimental margin error was determined by considering all the sources. The following conclusions were reached: (1) The laminar burning velocity decreases with the increase in CO2 percentage in the mixture due to the CO2 decreasing the flame temperature effect. (2) The flat flame type provided the highest value of burning velocity for each group of CO2 percentage in which it appears. (3) The highest obtained laminar burning velocity value was 22.64 ± 0.15 cm/s, for a flat flame with a ratio of 0.72 and 29.98% of CO2, while the lowest obtained value was 6.78 ± 0.15 cm/s for a conical trunk flame with a ratio of 0.59 and 49.83% of CO2. (4) The highest evaluated CO2 percentage was 50.97% for a conical trunk flame with a ratio of 0.69 and a burning velocity value of 11.04.

Application of electronic laryngoscope combined with narrow band imaging endoscope and its classification in the diagnosis of vocal cord leukoplakia

Objective:To investigate the clinical value of electronic laryngoscope combined with narrow band imaging（NBI） endoscope and its classification in the diagnosis of vocal cord leukoplakia. Methods:A retrospective analysis was performed on 115 cases of patients treated in the Department of Otolaryngology, Head and Neck Surgery, Nanjing Drum Tower Hospital from September 2020 to November 2022. All 115 cases were diagnosed with vocal cord leukogramma using the electronic laryngoscopy and narrow band imaging endoscopy, followed by pathological examination in the outpatient tissue biopsy. The morphological characteristics of vocal cord leukoplakia and the correlation between narrow band imaging classification and pathological results were investigated. Results:Among 115 cases of vocal cord leukoplakia, 46 cases（40.00%） were diagnosed as benign lesions. Low grade intraepithelial neoplasia occurred in 29 cases（25.22%）. High-grade intraepithelial neoplasia（including carcinoma in situ） occurred in 22 cases（19.13%）. Invasive carcinoma（including suspected invasive carcinoma） was found in 18 cases（15.65%）. There were no statistical differences in the unilateral and bilateral distribution of vocal cord leukoplakia and pathological results（P>0.05）, but there were statistical differences in the size, thickness, lesion uniformity, clear boundary, pre-invasion commissure, symmetry,age over 55 years old, morphological classification, NBI classification and pathological results distribution（P<0.05）. The two-by-two comparison among the three groups of morphological classification（flat type, raised type, rough type） showed that P<0.017 was only compared between flat type and rough type, and P>0.017 was compared between the other two groups. The pairwise comparison among the three groups of NBI classification（Ⅲ, Ⅳ, Ⅴ） was statistically significant（P<0.017）. There was a high correlation between NBI classification and pathological diagnosis, and the correlation coefficient was 0.705（P<0.05）. The risk of high intraepithelial neoplasia and cancerization in type Ⅳ was 9.125 times higher than that in type Ⅲ, and the risk of high intraepithelial neoplasia and cancerization in type Ⅴ was 271.078 times higher than that in type Ⅲ. The area under the curve of morphological classification and NBI classification were 0.672 and 0.896, respectively. Conclusion:There is a high match and correlation between NBI classification and pathological diagnosis. Electronic laryngoscope combined with narrow band imaging endoscope has a high diagnostic value for vocal cord leukoplakia, and a strong predictive ability for malignant leukoplakia.

Computational fluid dynamics analysis of flat plate type solar collector under different fin variables to enhance air-based heat transfer

Purpose This study begins by outlining the core principles of how flat plate solar collectors (FPSC) operate and the underlying mechanisms of heat transfer. It underscores the pivotal role of fin patterns in enhancing convective heat transfer. Design/methodology/approach The primary objective is to examine the impact of diverse fin patterns on the thermal performance of FPSCs. The study involves the development of a 3D-CFD model for FPSC using the computational fluid dynamics (CFD) software ANSYS FLUENT. The analysis is conducted for variable mass flow rates (mf) ranging from 0.01 to 0.05 kg/s with an interval of 0.02 kg/s. Each flow rate is assessed for three distinct fin patterns: straight plate fins, V-shaped fins and wavy fins. Recognizing the variation in solar radiation intensity throughout the day, the analysis is executed at six different time points ranging 10:00 a.m. to 03.00 p.m. with a time interval of 1.00 h. Findings It is observed that the wavy fin pattern with a mass flow rate of 0.01 kg/s exhibited the highest outlet temperature, showing a significant temperature difference of 12.4 K at noon. Conversely, the V-shaped fin pattern with a mf of 0.05 kg/s has the lowest temperature difference value, measuring only 3 K. The analysis included the calculation of thermal efficiency for each case, revealing that the V-shaped fin pattern at a mf of 0.05 kg/s and a sun radiation intensity of 885.42 W/m2 achieved the maximum instantaneous thermal efficiency (ηth) of 34.7%. The study records the outlet air temperature for all of these combinations and presents the data graphically in the paper. Originality/value The findings of the simulations indicate that the thermal performance that is ηth and maximum temperature of outlet air of FPSCs can be improved through the utilization of variable fin patterns.

Factors affecting distribution of dose in horizontal direction during irradiation

Recording and managing the dose of x-rays in an x-ray machine is an important part of the data. In addition, recording and managing radiation dose data in x-ray devices plays an important role in providing transparency of radiation dose to medical staff and patients by quantifying the radiation dose data. Four mobile diagnostic X-ray units were used to analyze the dose by spatial location. The dose distribution by location was analyzed by identifying and analyzing the dose by angle for both image intensifier and flat panel detector types. The three-dimensional space of the radiation area consisted of 27 sides, and the structure of the space was assumed to be horizontal X, Y, and Z sides and vertical A, B, and C sides, and the dose analysis was performed at the assumed position. On the longitudinal side, the highest dose tissue (highest μSv/min) is B_Center : (R.B.M, Colon, Lung, Stomach, Breasts, Remainder of body) - 330.404 μSv/min, and the lowest dose tissue (lowest μSv/min) is 0.002 μSv/min on the (Skin, Bone surface, Salivary glands, Brain) side at C_270°. The findings from diagnostic X-ray devices have emphasized the importance of managing radiation exposure when using the devices and may raise questions about the management of radiation protection measures to protect the health of healthcare personnel and patients. This can be expected to advance the organization of the use of radiation devices in a safe healthcare environment. A system for managing data will be useful as an indicator to guide medical staff using the equipment and patients participating in procedures and surgeries where they can minimize their dose and avoid harm.

Energetic and economic analysis of a novel concentrating solar air heater using linear Fresnel collector for industrial process heat

Industrial processes share a relevant portion of global energy consumption. A large variety of high energy-demanding industrial processes need hot air in the medium temperature range, provided by natural gas combustion or by electricity. Hot air is used as a medium in a large variety of processes such as drying, curing, and thermal treatments of several products and materials. Heat can be provided by solar thermal technologies aimed at the sustainable industry. Non-concentrating flat plate type solar collectors can directly heat air up to 100 °C while higher temperatures can be achieved using linear concentrating technology. In this study an innovative system using linear Fresnel collectors directly provides hot air for the industry up to 350 °C, avoiding the need for liquid heat transfer fluids. Accordingly, the installation is simplified, and lower installation and maintenance requirements are expected compared to other solar technologies. The present studies provide an energetic and economic analysis of the concentrating solar air heater, considering a medium-scale benchmark as a reference case in representative European locations. The results indicate that the solar technology here presented can be economically competitive with conventional natural gas heating, having a huge potential for fossil fuel source replacement in hot air based industrial processes.

Achievement of advanced alkaline Ni-Zn batteries with good durability at a high areal capacity of 10 mAh cm−2 via the synergistic regulation of dual electrolyte additives

Though obvious advantages in terms of safety, cost, environmental compatibility and electrochemical performance (e.g, power and energy density), the commercial application of alkaline Ni-Zn batteries, a number of traditional aqueous batteries, is still under great restrictions owing to the poor durability (commonly less than 100 cycles). In this work, an effective electrolyte modification process using dual additives of hydroxy-rich carboxymethyl cellulose (CMC) that can inhibit hydrogen evolution reaction (HER) and suppress Zn dendrites, and benzyltrimethylammonium bromide (BTMAB) that can mitigate passivation and oxygen evolution reaction (OER) is developed. Meanwhile, our home made C coated ZnO (ZnO@C) microspheres were used as initial anode materials without the using of any other expensive composites. With a fixed areal charge capacity of 10 mAh cm−2, the flat type full cell matched with commercial Ni(OH)2 cathode can deliver a high average discharge capacity of ∼9.6 mAh cm−2 (corresponding to an average CE of 96 %) for a long lifespan of over 390 cycles, which drops to 8.2 mAh cm−2 at 400th cycle accompanied by the appearance of a peak in the charge curve. The cumulative discharge capacity of a full cell can reach ∼4,000 mAh cm−2 in 420 cycles’ cycling, much larger than that using commercial Zn/ZnO anode and the ZnO@C anode in unmodified or single additive modified electrolyte (less than 1,500 mAh cm−2).

Design and Optimization of the Shape of a Single-person Submersible based on ANSYS

Due to the complex growth environment of wild sea cucumbers, the difficulty and low efficiency of traditional ROV identification, at present, wild sea cucumber fishing is mainly obtained through manual fishing, in order to ensure the life safety of divers and improve the fishing efficiency of sea cucumbers, new ideas and solutions for single-man submersibles suitable for shallow water operations are proposed. Under the condition of ensuring the driver's operating space, the shape and structure of an easy-to-process manned submersible are designed to optimize its resistance performance. Creo was used to establish a model of a single-man submersible for shape design, and three design schemes were proposed: scheme 1 flat spindle type, scheme 2 imitation unmanned boat type, and scheme 3 imitation airfoil type. The drag performance of the single-man submersible is simulated and analyzed by using the Fluent module in the analytical fluid dynamics simulation software Ansys, and the results show that the drag performance of scheme 3 imitation airfoil type is better than that of other schemes.The conclusion was verified by simple experiments.It provides effective reference information for the subsequent structural optimization of single-man submersibles.

AdaBoost algorithm for the recognition of young women’s body shapes based on 2D images

Classifying and recognizing the human body shape during human body measurements based on 2D images helps to improve measurement accuracy. In this paper, 430 young women's 2D body images were selected to establish 2D body datasets. The characteristic indices used to represent the body shape in 2D images were extracted by computer vision technology, namely the body height pixel value, projected unit area, and projected area ratio of the front and side of the body. The two-step cluster model was used to classify the body shape into three clusters: the tall, flat, and medium fatness type; the short, thin, and medium roundness type; and the round, fat, and medium height type. Then, the decision tree model and AdaBoost algorithm, an ensemble learning algorithm with the decision tree as the weak classifier, were used to recognize the body shape. The results show that the recognition accuracy of the decision tree recognition model was 93.19%. The body shape recognition method using AdaBoost achieved a better recognition effect than the decision tree model, and the recognition accuracy of the test set reached 97.35%. Through comparative study, we found that the recognition accuracy of the 2D body shape recognition method based on AdaBoost was improved and that the recognition accuracy was relatively stable. This study provides a new method for the recognition of human body shape in clothing customization and online shopping.

Characteristics and Simulation of Icing Thickness of Overhead Transmission Lines across Various Micro-Terrains

The hazard of ice accretion on overhead power circuits is significant, yet predicting it is very difficult. The key reason lies in the shortage of sufficient observational data on ice thickness, and previous studies have also rarely taken into account micro-terrain and micro-meteorological conditions. In response to the challenge of simulating overhead line icing, this study introduces a new icing simulation technique that fully considers the effects of micro-terrain and micro-meteorology. For this technique, typical micro-terrains of overhead line areas are first identified by using high-resolution elevation data, and the icing thickness characteristics in different micro-terrains are analyzed. Subsequently, icing thickness simulations for different micro-terrains are conducted. The results indicate that during the icing process, the icing thickness ranges from 5 mm to 8 mm under three types of micro-terrain, namely, “uplift type”, “alpine drainage divide type” and “canyon wind channel type”, whereas the icing thickness is less than 5 mm in the “flat type” of micro-terrain. This finding suggests that the first three micro-terrain types facilitate icing on overhead transmission lines due to the condensation and uplifting effects of water vapor caused by terrain. However, flat terrain lacks the conditions necessary for water vapor accumulation and thus is not easy to form icing. The results are advantageous for the deployment of overhead power lines in intricate terrain. It is advisable to steer clear of regions susceptible to icing, and endeavor to install circuits in level territories whenever feasible. In addition, the simulated icing thickness under different terrains is in good agreement with the observations. Specifically, the correlation coefficient between simulated and observed icing thickness is significant at the 0.99 confidence level, and the deviations between them are within 0.5 mm. This signifies that the forecasting methodologies employed are dependable and possess significant implications as a reference for disaster prevention and mitigation efforts.

Analysis of clinical characteristics and curative effects of 169 patients with bilateral sudden sensorineural hearing loss

Objective: To analyze the clinical characteristics, curative effect related factors and follow-up situation of bilateral sudden sensorineural hearing loss (BSSHL). Methods: The clinical data of 169 patients(338 ears) with BSSHL were retrospectively summarized, and the demographic characteristics, predisposing factors, concomitant symptoms and diseases, and audiological characteristics were statistically described. Additionally, influencing factors of curative effect and prognosis were statistically analyzed. Results: Among the 169 patients, 50.9% (86/169) of patients had at least one incentive, with cold and fatigue being the most common incentives(both 23/169). There were high rates of accompanying symptoms including tinnitus (150/169, 88.8%) and dizziness (100/169, 59.2%). Hypertension(49/169, 29.0%)and diabetes(23/169, 13.6%)were the most common concomitant diseases observed. Most cases exhibited all frequencies involvement, with flat type and total deafness type accounting for 83.1%(281/338 ears). The most common degree of hearing loss was total deafness(86/338 ears), with approximately 60.1%(203/338 ears) of the cases being severe or worse. The total effective rate of treatment was only 29.0%, but it increased to 39.5% for patients with course of disease≤14 days, however, when course of disease>30 days, the effective rate decreased sharply to 3.6%, showing a significant difference between these two groups(χ2=13.776,<0.01). Different types of hearing curves showed statistically significant difference in efficiency(χ2=14.782, P<0.01). Comparing the hearing improvements of 28 BSSHL patients from admission to discharge and from discharge to follow-up, it was found that the hearing improvement of the two groups showed statistically significant difference at the frequencies of L-250 Hz, L-500 Hz, R-125 Hz, R-250 Hz and R-500 Hz(Z value was -2.495, -3.083, -3.970, -3.388 and -3.264 respectively, all P<0.05). The proportion of patients with elevated serum IgE was much higher than that of the normal population. Conclusion: BSSHL patients suffer from serious hearing loss, and many also experience tinnitus and vertigo symptoms. Due to the poor efficiency of treatment, it is better for patients to be treated within 30 days of onset. For patients of hearing loss in the low frequency range, hearing improvement is more significant during hospitalization. And the occurrence of BSSHL may involve an immune mechanism.

Experimental Investigation of the Behavior of SlFCON Column under Eccentric Monotonic Load

Abstract This research delves into the performance of Slurry Infiltrated Fibrous Concrete (SIFCON) columns when subjected to eccentric monotonic loading, through the examination of twenty columns until their point of failure. The research addresses gaps in existing literature by examining the effects of various parameters, including fiber type, volume fraction, and eccentricity ratio, on SIFCON column performance. Results reveal significant correlations between the studied parameters and the structural behavior of SIFCON columns. The investigation shows how the ultimate load affect by the eccentricity ratio, for instance, the hook end steel fiber with a volume fraction of 6%, where the ultimate load decreased by a factor of 0.25 when the eccentricity ratio changed from 0.1 to 0.5. Furthermore, increasing the volume fraction of steel fibers significantly enhances the energy absorption of SIFCON columns. For instance, with the hook-end steel fiber and an eccentricity ratio of 0.3, the energy absorption increased by a factor of 2.76 when the volume fraction of steel fiber changed from 4% to 9%. The type of fibers used plays a pivotal role in the material behavior of SIFCON, with the straight micro fiber exhibiting an ultimate load 2.17 times greater than flat crimped steel fiber types when the volume fraction was 9% and the eccentricity ratio was 0.3. Finally, based on the experimental results, an interaction diagram has been established for three types of SIFCON: straight micro steel fiber with a volume fraction of 12%, hook end steel fiber with volume fractions of 6% and 4%.

Study of the variation of the leading edge of a railway crane on the aerodynamic characteristics

The front body design of the railway crane is flat or bluff type. The design causes a large drag, so the railway crane requires high fuel consumption to drive. Therefore, this study aims to modify the front body of the railway crane by applying the shape of the leading edge to reduce drag. This research also investigates the effect of leading-edge angles on aerodynamic characteristics. The method used is computational fluid dynamics, using the flow simulation feature of the Solidworks research licence software. This study considered three variations of leading edge angle (40°, 45° and 50°). The simulation results show that the larger the leading edge angle, the lower the drag coefficient value. In addition, the simulation shows that there is a high air pressure at the front of the railway crane with the bluff shape, while the modified railway crane with the leading edge applied has a lower air pressure at the front. Furthermore, the results and discussion in this article present the simulation results showing the velocity streamline and pressure contour of each model.

Transport Characteristics and Potential Source Areas of PM2.5 in Yangquan City Under Different Pollution Levels

Based on the PM2.5 monitoring data, NCEP data, and the meteorological data of the weather situation analysis at the corresponding time in Yangquan City from 2020 to 2022, using the HYSPLIT4 backward trajectory model, multi-station potential source contribution factor analysis （MS-PSCF） and trajectory density analysis （TDA） were introduced to study the differentiation and classification of PM2.5 transport channels and potential sources in Yangquan City. The results showed that： ① The PM2.5 pollution in Yangquan was mainly concentrated in Yangquan and Pingding, whereas the pollution in Yuxian was relatively light. The proportion of days with different pollution levels and the average and maximum values of PM2.5 concentration in Yangquan and Pingding were significantly higher than those in Yuxian, and the distribution characteristics of PM2.5 were closely related to the local special terrain. ② The amount of PM2.5 pollution and the concentration of PM2.5 in different pollution levels were the highest in light wind weather. The influence of east-west regional transport on PM2.5 pollution times and PM2.5 concentration of Yangquan and Pingding was obvious, and the contribution of east wind was significant. The influence of local pollution sources was the main factor in the moderate pollution weather in Yuxian County. ③ There were four main ground conditions for the generation and maintenance of moderate or above pollution weather： warm low pressure type （22%）, high pressure front （bottom） type （54%）, high pressure back type （14%）, and pressure equalization field （10%）. High pressure front （bottom） type was the main ground situation causing the increase in PM2.5 concentration. There were two types of upper air conditions, namely, flat westerly flow type （78%） and northwest flow type （22%）. The upper westerly flow type was the main upper air condition that caused the increase in PM2.5 concentration. ④ The results of transport channels and potential source areas of PM2.5 with different pollution levels obtained by MS-PSCF and TDA were consistent. The main transport channels of PM2.5 were the northeast, southeast, and northwest channels, whereas the northeast and southeast channels were short-distance transport routes, which were the main routes causing the increase in PM2.5 concentration. The northwest channel was consistent with the northwest dust transport channel, belonging to long-distance transmission. The main potential source areas of PM2.5 pollution were located in the central and western parts of Hebei and the southeast part of Hebei, the northeast part of Henan and its junction with the southwest part of Shandong, and the southeast part of Shanxi.

Metrology analysis and thoughts of literatures on tinnitus associated with sudden deafness based on CiteSpace

Objective: To explore the incidence of sudden deafness accompanied with tinnitus, the selection of examination protocols and treatment, and to provide reference for the establishment of new guidelines for sudden deafness. Methods: CiteSpace software was used for analysis and data mining to analyze and summarize the computer-retrieved articles on diagnostic examination and treatment of sudden deafness accompanied with tinnitus collected from CNIC, Wanfang and Web of Science databases from 2011 to 2021. Results: A total of 207 randomized controlled studies were retrieved in this study, including 121 in Chinese and 86 in English. Finally, 74 Chinese literatures and 16 English literatures were included. Among the 74 valid Chinese literatures, 64 (86.5%) were accompanied with tinnitus, 58 (78.4%) with dizziness/vertigo, 25 (33.8%) with aural fullness, 10 (13.5%) with headache, 4 (5.4%) with insomnia, 4 (5.4%) with a mixture of dizziness and tinnitus, and 2 (2.7%) with vomiting. Among the 16 English literatures, 15 (93.8%) were accompanied with tinnitus, 12 (75.0%) with vertigo, 1 (6.3%) with aural fullness, and 1 (6.3%) with a mixture of various symptoms. Among the 64 Chinese articles mentioning tinnitus, only 9 mentioned tinnitus matching tests, and 1 mentioned that the treatment for tinnitus accompanying symptoms was sound therapy and psychological counseling. The incidence rates of tinnitus accompanying four different types of sudden deafness, from low to high, are as follows: low-to-mid frequency, 82.4%; mid-to-high frequency, 90.7%; complete deafness, 92.4%; and flat type, 92.8%. Conclusion: Tinnitus is the most common accompanying symptom of sudden deafness, and tinnitus matching test is an effective evaluation method. When establishing a scientific, comprehensive, and systematic diagnosis and treatment system or guidelines for sudden deafness, attention should be paid to the diagnosis and treatment of tinnitus symptoms and their adverse psychological reactions, in order to reduce the incidence of tinnitus patients in the later stage of recovery from sudden deafness.