Maximum Pressure Value Research Articles

Improving a methodology for estimating the cross-country ability of all-wheel-drive vehicles

The object of this study is the cross-country ability of four-wheel drive vehicles under off-road conditions. Based on the results of analysis of known studies, it was determined that the procedures of experimental assessment of the load-bearing capacity of bearing surfaces (BS), based on the use of the cone index, are used in NATO member countries. They take into account the characteristics of the surface of the theater of operations and make it possible to determine the approximate speeds of all-wheel drive vehicles with the help of standardized computer software. In the procedures for assessing the load-bearing capacity of BSs, which use the soil deformation module E, there is no possibility for calculating the speed of the car with known axle loads. In addition, they provide for the determination of a number of parameters of the bearing surface, such as the coefficient of adhesion, the angle of internal friction in the soil, and the shear modulus during the formation of a track. This makes them much more difficult compared to the procedures used by NATO. Therefore, the problem that is solved in this work is to improve the methodology for assessing the reference cross-country ability of four-wheel drive vehicles. Based on the results of scientific research, motion modeling was carried out in the MATLAB Simulink environment to determine parameters of reference cross-country ability of four-wheel drive vehicles. In order to determine the cross-country ability of samples of wheeled military vehicles (WMV) based on the indicator of the maximum pressure value (mean measure pressure – MMP), the conducted experimental studies were analyzed. They showed a difference in the speed modes of vehicles of the same gross weight but different layout schemes, within 11–12 %. Therefore, the methodology for assessing the cross-country ability based on MMP has been improved to take into account the features of the layout of WMV samples. Specifically, taking into account the different values of loads on the front axle of vehicles with hoodless and hood layouts at the same gross weight. In general, the improved procedure makes it possible to give a quantitative assessment of the movement mobility of WMV samples with various layout schemes and an assessment of their potential cross-country ability on the basis of the proposed refinement of MMP calculation

Water jet vacuum cooling system for improving the quality of multiflora honey from bee (Apis dorsata Fabricus) in Indonesia

Honey has great benefits to humans, both as medicine and food. It contains glucose, fructose and water in addition to small quantities of proteins, minerals, organic acids, and vitamins. Vacuum cooling is a rapid cooling technique based on the principle of evaporation, which lowers the boiling point of water based on the vacuum pressure inside a cooler room. A prototype vacuum-cooling jet water system was used to process the honey. Raw honey obtained from the forests of Riau was used in the present study. This study aimed to determine the effect of jet water vacuum cooling with variations in volume (V/V), capacity (12.5%, 25%, and 50%) on the quality of honey (Apis dorsata Fabricus) to accelerate the cooling process and preserve product quality. The cooling mechanical analysis parameters reviewed included the processing time and the lowest maximum pressure. The parameters of the quality of honey observed included moisture content, viscosity, density and total dissolved solids. As a result, the vacuum cooling process can suppress damage to the quality of honey owing to the heating process. At the cooling time and lowest maximum pressure value, the mechanical aspects of the water jet system vacuum cooling process showed the maximum results. The water contents of 12.5% (V/V), 25% (V/V) and 50% (V/V) filling were 13.69%, 12.89%, and 14.25%, respectively. The viscosities at 12.5% (V/V), 25% (V/V) and 50% (V/V) filling were 2.604 Pa.s, 2.355 Pa.s, and 1.644 Pa.s, respectively. Density with 12.5% (V/V), 25% (V/V) and 50% (V/V) filling were 1.52 g/cm3, 1.53 g/cm3 and 1.50 g/cm3, respectively. Total dissolved solid values of honey with 12.5 % (V/V), 25 % (V/V), and 50 % (V/V) fillings were 78.16%, 78.16% and 77.66%, respectively. Water jet vacuum cooling with a 25% chamber volume capacity accelerates honey with the best total dissolved solids, density and moisture content. Vacuum cooling can be used to improve product quality, shorten handling time, extend product shelf life and improve security. Key words: honey, pressure, vacuum cooling, density, moisture content, viscosity

Penyelidikan Tanah Menggunakan Metode Uji Sondir Di Universitas 17 Agustus 1945 Surabaya

Cone Penetration Test (CPT) is a method designed to determine and test the strength of soil layers quickly and is one of the most widely used testing methods. The aim of this research is to determine the resulting bearing capacity and determine the hard soil layers on the Padhang-Padhang campus of West Sulawesi University using the Cone Penetration Test (CPT) or Sondir field testing tool. The method used in this research is the literature study method and direct testing in the field. From the results of this test, the Cone Penetration Test (CPT) data from 1 test point was processed and analyzed using Microsoft Excel 2019 software. The results of data processing and analysis were the maximum cone pressure (qc) value and the maximum number of sticking resistances (JHP), namely 650 kg/cm at a depth of 12.60 meters and 2496.00 kg/cm² at a depth of 15.00 meters. The maximum friction ratio (Rf) of 0.11% is at a depth of 14.00 meters, while the maximum Sticking Resistance Pressure (fs) value of 110 kg/cm² is at a depth of 14.00 meters.

Experimental Data on Maximum Swelling Pressure of Clayey Soils and Related Soil Properties

Clayey soils exhibit significant volumetric changes in response to variations in water content. The swelling pressure of clayey soils is a critical parameter for evaluating the stability and performance of structures built on them, facilitating the development of appropriate design methodologies and mitigation strategies to ensure their long-term integrity and safety. We present a dataset comprising maximum swelling pressure values from 759 compacted soil samples, compiled from 16 articles published between 1994 and 2022. The dataset is classified into two main groups: 463 samples of natural clays and 296 samples of bentonite and bentonite mixtures, providing data on various types of soils and their properties. Different swelling test methods, including zero swelling, swell consolidation, restrained swell, double oedometer, free swelling, constant volume oedometer, UPC isochoric cell, isochoric oedometer and consolidometer, were employed to measure the maximum swelling pressure. The comprehensive nature of the dataset enhances its applicability for geotechnical projects. The dataset is a valuable resource for understanding the complex interactions between soil properties and swelling behavior, contributing to advancements in soil mechanics and geotechnical engineering.

Research on optimal design of 6in offshore flange connector’s sealing structure

Taking the maximum contact pressure as the objective function for, the optimal design model of the offshore flange connector was established to analyze the impact of the flange cone's angle and the curvature radius of the lenticular gasket's contact surface on the sealing performance of the connector. An optimized three-dimensional model of the offshore flange connector was constructed using the MATLAB software's fmincon function to obtain the optimal size of the cone angle and curvature radius. The maximum contact pressure and maximum equivalent stress values of the non-optimized and optimized offshore flange connectors under the cross combination of two design pressures and six operating temperatures were analyzed by Workbench software, and the sealing performance of the non-optimized and optimized offshore flange connectors was compared according to the sealing judgment basis. The results show that compared with the previously studied offshore flange connector, the sealing structure of optimized offshore flange exhibits maximum increase in contact pressure increase but maximum decrease in equivalent stress. Under actual operating circumstances, the optimized offshore flange connection performs better in sealing and is less prone to breakage.

Study on the pullout bearing characteristics of root piles in coral sand foundations under different water content states

Offshore wind energy will become one of the important sources of energy in the future, and root piles with good pullout bearing characteristics can be used for the foundation of offshore wind power generation facilities. Through the model test, the pullout bearing characteristics of root piles with different water content states in coral sand foundation are comparatively analyzed, and the pullout bearing deformation law and pile body force transmission characteristic law of root piles is revealed. The results show that when the coral sand foundation is saturated and the water level rises and falls, compared with the dry sand foundation, the pullout bearing capacity of the root pile decreases, and the ability to control the displacement is sharply weakened. The axial force curve at the root is in the shape of a step; after the foundation is affected by water, the maximum value of lateral friction resistance first appears at the bottom root, and the lateral friction resistance at the lower root is always greater than that at the upper root; the water level rise and fall leads to a decrease in the lateral friction resistance in the area of the pile without a root, and the lateral friction resistance in the area of the root is increased. Under saturated and water level rise and fall condition, the total bearing ratio of the root pile section increases, and the bearing ratio of the lower root pile section is always larger than that of the upper root. After loading, the soil in the upper part of the pile is compacted, and the soil in the lower part is loosened; the maximum value of soil pressure in the compacted area of the dry sand condition gradually moves downward, and the maximum value of soil pressure in the saturated and water level rise and fall condition is always located in the lowermost part of the compacted area; the pore water pressure in the saturated and water level rise and fall condition is basically equal with the hydrostatic pressure, and there is no obvious super pore water pressure generated. The research results provide scientific basis for the application of root piles in coral sand foundation.

Researching influence of the shape of blast resistant walls on the value of blast pressure impacting on structures by practical explosion test

This article presents the results of field explosion tests to determine the maximum pressure value of the blast wave acting on the front wall, side wall, roof and back wall of the building in cases with and without retaining walls. The author changed some retaining wall shapes to study the influence of the blast retaining wall shape on the maximum pressure value of the blast wave acting on the front wall, side walls, roof and back wall of the building, and draw some comments.

Mathematical modeling of the melt flow in the cone-ring channel of the extruder matrix

The peculiarity of the work is to develop a mathematical model of the melt flow in the cone-annular channel of the extruder die, which will allow you to choose the optimal geometric shape of the annular channel, as well as the angular rotation speed of the extruder screw. The object of the study is the cone-ring channel of the extruder matrix. To solve the three-dimensional problem of turbulent and laminar unsteady motion, the FlowVision software package was used, which allows solving partial differential equations using the finite volume method. The correct choice of the geometric shape of the annular gap made it possible to change the molecular structure of the product by creating a maximum pressure value. The optimally selected angular rotation speed of the extruder screw made it possible to carry out deep melting of the product due to the conversion of the mechanical energy of the screw into thermal energy. In the process of designing the forming of the cone-ring channel, the three volumes of the changing geometry of the stamp were selected, at the borders of the transition of which extreme points were observed. Deviations between the analyzed and experimental values of velocity and pressure were found in the limits of 9–12 % and 17–22 %, respectively. Based on the analysis of the obtained results of modeling, the optimal geometric shape of the annular gap and the recommended angular rotation speed of the extruder screw were revealed. The mathematical model proposed formed the basis of the developed design of the six-zone extruder. In the extruder, the geometric characteristics of the screw (variable pitch of the turns) were substantiated and selected, which provide the maximum effect of dissipation, i.e. autogenous mode of operation

Investigation of marginally explosible dusts

“Marginally explosible dusts (MEDs)” are a group of combustible dusts that are distinguished by relatively low volume-normalized maximum rate of pressure rise (KSt) and maximum explosion pressure (Pmax) values. Earlier studies have suggested that dusts with KSt values less than 45 bar m/s in the laboratory-scale 20-L chamber would not explode in the 1-m3 chamber and therefore not on an industrial scale. Conversely, for some metallic dusts, significantly higher KSt values are generated in the 1-m3 chamber. Industries that handle MEDs continue to search for answers to the questions “are they explosible or not?” and “should we protect or not protect against potential explosions of these dusts?“. To answer these questions, four well-characterized materials namely, carbon black, oat grain flour, urea, and zinc were tested in the current study. These materials were selected because they exhibit different combustion behaviors and also cover a range of industries. Five ignition energies (i.e., 0.5, 1, 2.5, 5, and 10 kJ) were used in the 20-L chamber tests. The results show a clear case of overdriving (as a result of the high ignition energy density in the 20-L chamber) with respect to urea and carbon black dusts. Nevertheless, the urea dust is non-explosible. The data also suggests that the choice of test chamber to generate suitable explosion data is strongly dictated by the combustion path of MEDs. However, there are exceptions. The study also establishes the importance of both chemico-physical and thermal analyses to understanding the explosion behavior of MEDs. With reference to urea dust, a new definition for MEDs has been suggested as dusts having Pmax < 3.0 bar(g), KSt < 20 bar m/s (in the 20-L chamber), MEC >1000 g/m3, MIE >1000 mJ, and MIT >600 °C. This work provides guidelines to industries that handle MEDs on the explosibility classification of these dusts, thus addressing the existing difficulty, and informing industry on the safety strategies required when handling this group of dusts.

Numerical Assessment of Tsunami Forces on Vertical Wall Structures: Impact of Inundation Depth and Incident Fluid Velocity

This study evaluates the tsunami forces exerted on a terrestrial structure caused by a collision-induced tsunami. Conventionally, assessing these forces relies on the inundation depth of the colliding tsunami passing without the presence of the terrestrial structure. However, it is essential to consider the inundation depth and incident fluid velocity, as both significantly influence the resulting tsunami forces. In this research, ANSYS Fluent 17.2 is employed to simulate excitation sources using a Defined Function (UDF) code within a C++ framework. The dynamic meshing technique is adopted to replicate the interactions between the bore pressure of the tsunami and an idealised vertical wall structure across three distinct water levels. Computational Fluid Dynamics (CFD) modelling demonstrates the proposed methodology's capability to offer precise impact pressure distributions concerning geographical and temporal aspects. The findings reveal specific instances: at a water depth of 10 m, the maximum Froude number is attained at 3.5 and 6.9 seconds, corresponding to a maximum pressure value of 3.9x105 Pa at 3.85 seconds for a water flow velocity of 20 m/sec. Similarly, for a water depth of 12 m, the most significant Froude number is observed at 3.95 and 6.9 seconds, with a peak pressure value of 1.8x105 Pa at 4.6 seconds, associated with a water flow velocity of 15 m/s. Additionally, at a water depth of 14 m, the maximum Froude number is reached at 4.95 and 7.1 seconds, accompanied by a maximum pressure value of 7.4x104 Pa at 4.85 seconds for a water flow velocity of 10 m/s.

Modification of velopharyngeal closure pressures during phonation by neuromuscular electrical stimulation in healthy individuals.

Rhinophonia aperta may result from velopharyngeal insufficiency. Neuromuscular electrical stimulation (NMES) has been discussed in the context of muscle strengthening. The aim of this study was to evaluate in healthy subjects whether NMES can change the velopharyngeal closure pattern during phonation and increase muscle strength. Eleven healthy adult volunteers (21-57 years) were included. Pressure profiles were measured by high resolution manometry (HRM): isolated sustained articulation of /a/ over 5 s (protocol 1), isolated NMES applied to soft palate above motor threshold (protocol 2) and combined articulation with NMES (protocol 3). Mean activation pressures (MeanAct), maximum pressures (Max), Area under curve (AUC) and type of velum reactions were compared. A statistical comparison of mean values of protocol 1 versus protocol 3 was carried out using the Wilcoxon signed rank test. Ordinally scaled parameters were analyzed by cross table. MeanAct values measured: 17.15±20.69 mmHg (protocol 1), 34.59±25.75 mmHg (protocol 3) on average, Max: 37.86±49.17 mmHg (protocol 1), 87.24±59.53 mmHg (protocol 3) and AUC: 17.06±20.70 mmHg.s (protocol 1), 33.76±23.81 mmHg.s (protocol 3). Protocol 2 produced velum reactions on 32 occasions. These presented with MeanAct values of 13.58±12.40 mmHg, Max values of 56.14±53.14 mmHg and AUC values of 13.84±12.78 mmHg.s on average. Statistical analysis comparing protocol 1 and 3 showed more positive ranks for MeanAct, Max and AUC. This difference reached statistical significance (p=0.026) for maximum pressure values. NMES in combination with articulation results in a change of the velopharyngeal closure pattern with a pressure increase of around 200% in healthy individuals. This might be of therapeutic benefit for patients with velopharyngeal insufficiency.

Changes in body balance due to exposure to trauma – multi-center studies

Aim. The purpose of the study was to assess the impact of a traumatic event experienced by the subject on postural balance and biomechanical parameters of gait. Research methodology. The study involved 31 people (n = 100%), including 22 women (nk% = 70.97%), 9 men (nm% = 29.03), aged 29-60. People with diseases and dysfunctions affecting body balance and gait pattern were excluded from the study. Balance and gait tests were performed using pedobarography (pedobarograph mod. EPS R2, Biomech Studio v2 software). The balance test was performed while standing, for 20 seconds, with sampling every 1 ms (millisecond) – the number of samples during one test is 20,000. The balance and gait assessment tests were performed twice. Test I included testing in neutral conditions, Test II included testing in conditions in which the subject was exposed to a traumatic event he or she had experienced in the past (so-called exposure to “experienced trauma”). Results. The obtained results of studies on the impact of exposure to experienced trauma on body balance while standing showed significant differences in body fluctuations in the most important parameters of stabilometric assessment. The obtained results of research on the impact of exposure to trauma on the subject’s gait showed no significant differences between the test in neutral conditions and the test during exposure. Conclusions. (1) Exposure to the trauma experienced by the subject significantly affects the body’s balance in a standing position. (2) The research showed no influence of exposure to the experienced trauma on the subject’s gait in the area of the time of contact of the feet with the ground and on the values of maximum and average pressure; The area of the plane where the feet are placed on the ground changes significantly before and after exposure to the trauma experienced by the subject. (3) In research on the impact of trauma on body posture, detailed results of studies on the range of COP fluctuations in each plane should be taken into account – the study showed that the analysis of only average results may significantly indicate an incorrect result in the assessment of body balance.

Normal Values of High Resolution Anorectal Manometry in 132 Romanian Healthy People.

The primary method for assessing anorectal function is high resolution anorectal manometry (HRAM). It is a useful tool in the diagnosis of different anorectal functional disorders such as fecal incontinence or dyssynergia. The aim of the present study was to propose a new set of normal values to be used in practice for East-European individuals, as it was proven that the results are highly influenced by race and sociocultural status. We conducted a study based on anorectal manometric values of healthy volunteers analyzed at Clinic Fundeni Institute, Bucharest, Romania, between 2017 and 2022. The anorectal manometry was performed using a solid-state catheter (Diversatek, 23 pressure sensors). All anorectal measurement values were analyzed using the Bioview Software Analysys, respecting the timing and the order from the standardized IAPWG protocol. Manometric measurements were summarized using mean, median, standard deviation, minimum and maximum values. The impact of age and gender on 8 different manometric parameters was further analyzed. Normal ranges for all numeric variables were estimated using the 5th and 95th percentiles of the measurements. A total of 132 subjects (97 females, 35 males) were enrolled in the study. Median age was similar between groups (54 vs. 55 years). The values for rectal propulsion, anal gradient and anal relaxation proved to be higher in females under 54 years as opposed to older women. The values for resting pressure, maximum squeeze pressure, incremental squeeze pressure were significantly higher in males younger than 54. Regardless of age, values for maximum squeeze pressure, incremental squeeze pressure, duration of squeeze and rectal propulsion were found to be significantly higher in males than in females. Normal values of HRAM in healthy volunteers are presented in a table at the end of the study. The data presented in the current study are of high value and have a great impact on clinical practice, being the first study offering a spectrum of the normal values for HRAM in an Eastern Europe population.

The effects of speed and terrain characteristics on the distribution of force and plantar pressure during the gait of children with different levels of physical activity

&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Introduction. &amp;lt;/strong&amp;gt;The adoption of correct walking patterns is an indicator of the locomotor system readiness to establish optimal interaction between body force and the surface, and the way of creating pressure exerted by the feet during the walking cycle. The aim was to examine how the speed and characteristics of the terrain affect the distribution of force and plantar pressure during the gait of children with different levels of physical activity.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Methods.&amp;lt;/strong&amp;gt; A prospective comparative study included 150 students aged 11&amp;amp;ndash;12 years and their parents from Banja Luka. According to the protocol, each group of subjects walked at average and maximum speed on flat and 5% inclined terrain. For the purposes of the research, the Physical Activity Questionnaire PAQ-C (The Physical Activity Questionnaire for Older Children), a survey questionnaire for parents, measurement of anthropometric parameters and Zebris strips (Zebris Medical GmbH, Germany) were used for gait analysis.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Results.&amp;lt;/strong&amp;gt; When walking at maximum speed in inactive subjects, the maximum force on the left (F(148) = 14.878, p &amp;amp;lt; 0.001) and right (F(148) = 8.204, p &amp;amp;lt; 0.001) heel decreased, while in moderately and highly active subjects it grew moderately. In highly active subjects, the highest value of maximum pressure was registered (d = -1.41 for the left leg and d = 1.36 for the right leg). When the slope of the terrain changes in inactive subjects, the maximum force on the front part of both feet decreased (F(148) = 5.043, p = 0.008, d = 0). The influence of terrain characteristics was such that walking on a 5% incline almost as a rule had greater effects on inactive children, while moderately and highly physically active children gave an adequate response when walking on the 5% incline.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Conclusion.&amp;lt;/strong&amp;gt; Urbanization and new developments in society impose the need to involve children in organized activities so that children acquire the skills and demonstrate the competence they face in their environment.&amp;lt;/p&amp;gt;

Synchronous Grouting Analysis of Shield Tunneling through High Water Pressure Fault Fracture Zone

Using numerical software to establish a three-dimensional geological model of shield tunneling through fault fracture zones, considering the synchronous grouting effect at the shield tail, the disturbance of various geotechnical structures in the fault fracture zone under deep burial and high water pressure conditions is studied. According to the comparison between the numerical model analysis results and the on-site inspection results of the entire process of Shiziyang B3 section, synchronous grouting at the shield tail is the main reason for the changes in soil and water pressure in the fault fracture zone area. The soil and water pressure changes strongly during shield tunneling, and the maximum excess pore pressure value occurs when the shield tail passes. When the shield tunneling machine is far away, the soil and water stress shows a downward trend. The impact of synchronous grouting decreases with the increase in tunneling distance. Due to the difference in permeability, the variation law of pore pressure in the fault fracture zone is significantly different from the original rock, leading to a faster increase in pore pressure in the fracture zone area and a wider range of influence.

Analisis Ketahanan Rangka Stasiun Pengisian Kendaraan Listrik Berbasis Panel Surya Portabel Terhadap Laju Angin

High wind velocity can induce external pressures and loads on the structural framework of an Electric Vehicle Charging Station (EVCS), jeopardizing the overall stability and structural integrity of the framework. The objective of this research is to ascertain the magnitude of aerodynamic drag force and the maximum pressure values on the surface of the EVCS framework, with respect to variations in wind velocity. The methodology employed in this study involves Computational Fluid Dynamics (CFD) simulations utilizing the Solidworks Flow Simulation. Three wind velocity scenarios were considered: 3 km/h, 6 km/h, and 9 km/h, allowing for the observation of airflow acceleration phenomena, aerodynamic drag force values, and peak pressure distributions on the EVCS framework's surface. Research findings reveal that the aerodynamic drag force at a wind velocity of 3 km/h measures 22,34 N, escalating to 90,42 N at 6 km/h wind velocity, and reaching 202,7 N at 9 km/h wind velocity. Furthermore, the highest-pressure value at a wind velocity of 3 km/h is 101325,45 Pa. As the wind velocity increases to 6 km/h, the maximum pressure value rises to 101338,18 Pa. Under the condition of the highest input wind velocity, i.e., 9 km/h, the peak pressure reaches 101353,46 Pa.

Correlation between the female pelvic floor biomechanical parameters and the severity of stress urinary incontinence

BackgroundStress urinary incontinence (SUI) is a common condition that requires proper evaluation to select a personalized therapy. Vaginal Tactile Imaging (VTI) is a novel method to assess the biomechanical parameters of the pelvic floor.MethodsWomen with SUI were enrolled in this cross-sectional study. Participants completed the Medical, Epidemiologic, and Social Aspects of Aging (MESA) questionnaire and the Patient Global Impression of Severity Question (PGI-S) and underwent a VTI examination. Based on the MESA and PGI-S questionnaires, participants were divided into mild, moderate, and severe SUI groups. Fifty-two biomechanical parameters of the pelvic floor were measured by VTI and compared between the groups (mild vs. moderate and severe). SUI Score and Index were calculated from the MESA questionnaire. Pearson correlation was used to determine the strength of association between selected VTI parameters and the MESA SUI Index and MESA SUI Score.ResultsThirty-one women were enrolled into the study. Significant differences were observed in the VTI parameters 16, 22–24, 38, 39 when the difference between mild and severe subgroups of SUI based on the PGI-S score was examined. Parameter 16 refers to the maximum gradient at the perineal body, parameter 22–24 refers to the pressure response of the tissues behind the vaginal walls, and parameter 38, 39 refers the maximum pressure change and value on the right side at voluntary muscle contraction. VTI parameter 49, describing the displacement of the maximum pressure peak in the anterior compartment, showed a significant difference between the mild SUI and the moderate-severe SUI according to the MESA SUI score (mean ± SD 14.06 ± 5.16 vs. 7.54 ± 7.46, P = 0.04). The MESA SUI Index and SUI Score displayed a positive correlation concerning VTI parameters 4 (the maximum value of the posterior gradient) and 27 (the displacement of the maximum pressure peak in the anterior compartment) (VTI4 vs. MESA SUI Index r = 0.373, P = 0.039; VTI4 vs. MESA SUI Score r = 0.376, P = 0.037; VTI27 vs. MESA SUI Index r = 0.366, P = 0.043; VTI27 vs. MESA SUI Score r = 0.363, P = 0.044).ConclusionsFemale pelvic floor biomechanical parameters, as measured by VTI, correlate significantly with the severity of SUI and may help guide therapeutic decisions.

Numerical investigation on the effects of fueling the Turbulent Jet Ignition gas engine with methane and hydrogen

The modern solution of two-stage combustion, namely the Turbulent Jet Ignition (TJI), enables the combustion of ultra-lean mixtures. Thanks to this solution, it became possible to reduce fuel consumption and, at the same time, to increase the combustion process indicators (including the overall combustion system efficiency). The article presents the results of numerical tests of a heavy-duty engine equipped with the TJI system running on gas fuels. The AVL BOOST software was used to analyze the effects of different fuel injection rates into the pre-chamber and various ignition timing angles, while maintaining a constant global excess air ratio. Increasing the proportion of hydrogen in the pre-chamber resulted in its reduction in the main chamber (the fuel dose was kept constant with different excess air coefficients in each of the chambers). The maximum combustion pressure values in both chambers were investigated. Changes in the amount of heat released and its release rate were determined. As a result of the simulations, different ignition and combustion conditions were presented for the tested fuels. Based on this, maps of fuel dose to prechamber vs. ignition advance angle were drawn up, showing selected thermodynamic indicators of the combustion process.

Quantification of liquid nitrogen injection efficiency and phase change expansion boost laws in coal seam borehole

The implementation of liquid nitrogen injection into coal seam boreholes is a prerequisite for its application to increase coal seam permeation. Exploring the efficiency of liquid nitrogen injection is of great significance in optimizing the settings of key injection parameters, thereby reducing costs. By using high-pressure liquid nitrogen tank, flowmeter, endoscope, thermocouple and mass balance, experiments of different liquid nitrogen injection rates were carried out in 1 m long coal seam borehole. The rules for changing the liquid nitrogen net level in the borehole at different injection rates were obtained: slow growth-linearly growth-slowly growth to stability, and the maximum net liquid level could reach 60 cm. The effective convection coefficient and radiation coefficient during the transient film boiling at the early stages of liquid nitrogen injection were calculated, and it was found that convective heat transfer dominated this stage. The liquid nitrogen injection efficiency at different injection rates was quantitatively investigated, and the maximum efficiency was 8.75 %, and the injection efficiency increases with the increase of injection rate. After stopping the injection, the net liquid nitrogen level in the borehole was analyzed, and they all decreased exponentially. A liquid nitrogen phase change expansion boost model was established and experimental verification passed. Further, it was calculated that the maximum value of liquid nitrogen phase change expansion pressure in a closed borehole of 1 m long coal seam was 45.8 MPa. The expansion pressure can play a dominant role in fracture propagation during the fracturing process, and combined with the damaging effects of liquid nitrogen cold shock on coal, it has a great development prospect in the field of coal seam permeability enhancement.

Fluid dynamics analysis for a production line

Magnetic filters are used on companies for mass flux and volume flux values that helps to cover day-to-day production. This work begins describing the problem of magnetic filters fractures as industrial interest. A brief description of how magnetic filters must work on application, according to requirements on process line. On next sections is possible to find the explaining of structural fracture and mistakes on the design or data sheet usually not considered on guaranteed policy. Are mentioned more than one math modeling, taking the simplest to show the effective value of maximum pressure tolerated on magnetic filters differs from estimated for controlled conditions. Solutions shown on the article are a first approach of a future general model theory that could explain how applied science works on a factory where there is no time to stop production. This work relates math model and some values on application, meaning both the project hypothesis modeling on factories requirements for their equipment. Results depict volume, velocity, density, and pipeline relation to the pressure increase over the values on data sheet from quality department tests. Conclusions describe the connection of the math model analysis and with real situations on the application or possible structural damage. And its relationship with the proper function of magnetic filters for the purpose of lifespan analysis on future works. This work is a proof that on few weeks, companies can have a solution for their problems letting them to buy some time to avoid any future issue.