Main Tube Research Articles

Development and testing of a measuring chamber for a device for express analysis of milk quality in a flow

Mechanization and robotization of dairy farms require the development of technologies for assessing the quality of manufactured products. Monitoring milk composition and milking duration in real time is especially important for prompt response to deviations in animal physiological state parameters and timely adjustment of rations when milk yields decrease. The first version of the scatterometric device for express analysis of milk quality used a glass measuring chamber with a simple round cross-section, but it did not ensure the reduction of the turbulent flow of the milk-air mixture to laminar. This study presents the development and testing of a prototype of a measuring chamber that provides deceleration and laminarization of the milk-air mixture flow. The device operates at a milking capacity of 1 to 6 l/min, flow speed from 0.2 to 1.8 m/s. In the developed measuring chamber, a special bypass is created at an angle of 45° so that it has a common slot with the main tube. In this bypass, the flow of the milk-air mixture is slowed down to reduce turbulence and the number of air bubbles that interfere with the operation of scatterometric devices. The measurement area of the device is located in the upper part of the bypass. As a result, the developed measuring chamber has an internal diameter of the main part of 15 mm, the bypass of 11 mm, and provides close to 100% filling of the branch with liquid at the moment of the milk plug passage. The developed measuring chamber allowed the new version of the express milk quality analysis device to achieve increased accuracy and stability of measurements.

Optimizing Ship Draft Observation with Wave Energy Attenuation and PaddlePaddle-OCR in an Anti-Fluctuation Device

With the development and application of artificial intelligence (AI) in the shipping industry, using AI to replace traditional draft survey methods in bulk carriers can significantly reduce manpower, lower the risks associated with visual observations, improve measurement accuracy, and minimize the impact of human subjective factors. Ultimately, the integration of software and hardware technologies will replace human visual observations with automated draft measurement calculations. A similar anti-fluctuation device described in this article has been used in ship draft observation based on AI-assisted proving, which can ease the fluctuation of the wave inside the pipe. Observers can directly read the water surface inside the pipe and compare it to the ship’s draft mark to obtain the final draft, effectively improving draft observation accuracy. However, some surveyors refuse to accept the readings obtained from this device, citing a lack of theoretical basis or the absence of accreditation from relevant technical authorities, leading to the rejection of results. To address these issues, this paper integrates wave energy attenuation theory with PaddlePaddle-OCR recognition to further validate the anti-fluctuation device for accurate ship draft observation. The experimental results are as follows: first, the pipe effectively suppresses the amplitude of external water surface fluctuations by 75%, explaining the fundamental theory that wave heights within the anti-fluctuation device are consistent with external swell heights. When taking a draft measurement, the system dynamically adjusts the position of the main tube in response to the ship’s movements, maintaining the stability of the measurement section and significantly reducing the difficulty of observations. Due to the reduction in fluctuation amplitude, there is a noticeable improvement in observation accuracy.

Observations from opening of a novel geotextile tube connection in field test site

A novel connection configuration for geotextile tubes was proposed, involving the insertion of an auxiliary tube between two main tubes, to ensure proper alignment and leveling when connecting them in a series, thus consolidating individual tubes into a unified structure while maintaining a consistent horizontal level. The novel connection was implemented at a test bed site in the Saemangeum reclaimed area, South Korea, to test exposure to the marine environment including sea waves, sun light exposure and reclamation process. This study presents the observations made upon opening the connection tube after 8 years. The observation shows that the connected geotextile tubes using the proposed auxiliary tube are suitable for use in long-term reclamation projects.

Pure copper extrusion additive manufacturing of lattice structures for enabling enhanced thermal efficiency in hydrogen production

The high geometrical complexity allowed by Additive Manufacturing (AM) of pure copper can support the development of more efficient catalytic supports that can enable the design of efficient reactors for key processes for energy transition, i.e., hydrogen production with methane steam reforming or CO2 conversion to synthetic methane, thanks to the enhanced thermal conductivity of the catalytic support. Low relative density lattice geometries with open cell copper geometries can be adopted as catalyst supports in the new generation chemical reactors to improve the heat transfer. This work presents a manufacturability study about pure copper lattice filters produced via metal Extrusion AM i.e., via feedstock 3D printing and sintering. The results show that feasible parts design can be reached and produced and that heat-exchange performances can be increased with respect to conventional supports, as confirmed by lab-scale heat transfer tests. A specific metrological assessment based on CTscan data is implemented on the printed parts to qualify them and to ensure a good thermal coupling between the printed filters and the heat exchanger main tube elements.

Introduction to a novel geotextile tube connection construction method: A case study of test site and field application

One particular challenge in constructing geotextile tubes is ensuring proper alignment and leveling, especially when connecting them in a series. This study introduces a novel connection configuration to address this challenge by inserting an auxiliary tube between two main tubes. The proposed connection method offers the advantage of consolidating individual geotextile tubes into a unified structure while maintaining a consistent horizontal level. The proposed connection technique was successfully applied both at test site and on dry construction platform for bridge construction. This study is beneficial for practicing engineers as it presents a new and effective method for connecting geotextile tubes, offering valuable insights into its practical application.

Cyclic deformation behaviors and damage mechanisms in P92 steel under creep-fatigue loading: Effects of hold condition and oxidation

P92 steel has gained plenty of attention as a top contender for steam generator components and main steam tubes due to the growing need to increase the energy conversion efficiency. However, a major contributor to the premature failure of these components remains the interaction of creep and fatigue damage caused by typical dwell fatigue loading conditions. In this study, creep-fatigue tests of P92 steel were conducted under strain-controlled cyclic loading including hold durations up to 3600 s at 873 K in air. Special attention was given to the influence of hold conditions and oxidation on cyclic deformation and damage mechanisms. The results revealed that introducing hold time substantially decreased the failure life, with compressive hold causing more severe damage than tensile hold. Additionally, oxidation became severer with longer hold time, resulting in increased surface roughness, crack initiation sites and density of secondary cracks. Fatigue dominated the failure in the case of the short-term tensile hold, and the interaction of creep, fatigue and oxidation dominated the failure in long-term tensile hold tests. In contrast, the failure in compressive hold case was dominated by fatigue and severe oxidation. Furthermore, a three-dimensional oxidation-creep-fatigue damage interaction diagram was proposed for quantitative assessments in practice.

Numerical Investigation of Heat Exchanger Enhancement for a Staggered Arrangement with Corrugated Rods in Front

The heat exchanger is used in many industrial and engineering activities.Where, numerous applications confirms on a large heat transfer rate. However, the twisted tube is one of heat transfer rate enhancement methods. Also, the turbulent flows are often used instead of laminar for enhancement heat transfer rate. Therefore, the tube arrangement can be used in a suitable way for utilized this purpose. The shape features of tubes in the heat exchangers are very important for enhancing their performance. As well, the pressure drop and heat transfer rate have a remarkable effect on the thermal efficiency of the heat exchanger. In this research, a numerical investigation with a new way for heat exchanger tube staggered arrangement is presented. Where new solid spiral rods with oval sections are inserted in front of main tubes to induce high turbulent flow intensity as well as redistribution airflow over exchanger tubes. However, the new air distribution will help the airflow pressure over all the tubes to push the thermal boundary symmetrically behind the tubes. Therefore, two different sectional tubes were presented (circular and elliptical). These cross-sectional areas for both types have the same values. The main tubes have no twisted to prevent decreases in pressure. The numerical analysis used the K- ε model at a low Reynolds number to the simulation of this situation. Where, the eddy will generate in the vicinity region to pipe walls due to twisted pipe as well as the obstruction the cross flow. However, there are a good improvement of heat transfer rate without spend any energy depending on the control the shape and arrangement of pipes. The results show that the corrugated rod will increase the Nusselt number at different values of Reynolds. However, the elliptic tube gives the best results for heat transfer rate and maximum Nusselt number. The results compared with others works and give a good agreement.

Improvement of Formability in Parallel Double-Branched Tube Hydroforming Combined with Pre-Forming and Crushing Processes.

In hydroforming of parallel double-branch tubes, the material entering the branch zone is obstructed by material accumulation in the main tubes and corners, which decreases the branch height. A tube hydroforming approach is combined with pre-forming and crushing (THPC) to mitigate this problem. A larger diameter tube blank is flattened for pre-forming and then subjected to radial compression for crushing. In the next step, hydroforming forms the parallel double-branch tubes. Experiments and numerical simulations are then carried out to analyze the effect of traditional tube hydroforming (TTH) and the proposed THPC process on the formability of parallel double-branch tubes. The results show that for tubes obtained via THPC, the tube burst pressure increases by 27.5% and the branch height increases 2.37-fold compared to TTH. Additionally, the flattening, pre-forming, and crushing stages cause work hardening of the tube when using the TPHC process. Flattened tubes undergo radial compression to improve the material flowing into the branch tube. The formability of parallel double-branched tubes can be improved by using the TPHC process. Consequently, tube hydroforming, combined with pre-forming and crushing, has been confirmed as a feasible forming process for fabricating parallel double-branch tubes.

An improved resonant DC link inverter with a simple structure

To further streamline the architecture of the resonant DC link inverter, this article shows an improved resonant DC link inverter with straightforward architecture. There is no oscillating capacitor on the main tubes. Part of the resonant current during resonance is detached from the main tubes. The soft-switching action of all the tubes of this topology can be effectuated by using a set of resonant cavities, and its topology is simple. It has main tubes for ZVS movement and auxiliary tubes for ZCS movement. Also, the circuit has a controllable zero voltage notch duration. The article will elaborate on the operating scheme of the circuit. Eventually, the simulation outcomes are given to validate the effectiveness of the circuit.

Influence of Porous Inserts and Compact Resonators on Onset of Taconis Oscillations

Abstract Taconis oscillations represent excitation of acoustic modes due to large thermal gradients inside narrow tubes penetrating cryogenic vessels from a warm ambient environment. These oscillations are usually harmful, as they may drastically increase heat leakage into cryogenic vessels and result in strong vibrations of measuring instruments. Placing a porous material inside a tube with a goal to increase acoustic damping or attaching a small resonator to the main tube are some of the possible ways to suppress or mitigate Taconis effects. However, when the porous inserts are positioned in locations with large temperature gradients or the resonator parameters are selected incorrectly, these components may augment thermal-to-acoustic energy conversion and enhance Taconis oscillations. A low-amplitude thermoacoustic model has been extended and applied in this study to determine the effects of the insert location and pore radius, as well as the resonator dimensions, on the onset of Taconis phenomena in a hydrogen-filled tube of relevance to lines used in cryogenic hydrogen storage tanks. The presented findings can assist cryogenic specialists interested in suppressing or exciting Taconis oscillations.

Tube-to-tube impact wear damage mechanism and nonlinear ultrasonic detection method of alloy 690 tubes

Tube-to-tube impact wear is one of the prime reasons that cause the failure of alloy 690 tubes in nuclear steam generators. Therefore, it is of great importance to study the tube-to-tube impact wear damage mechanism and damage detection method of alloy 690 tubes. In this paper, the tube-to-tube impact wear experiments are conducted on alloy 690 tubes under different impact loads and cycle numbers. The impact wear damage mechanism of alloy 690 tubes is revealed by analyzing the macro and micro morphologies as well as metallographic structures of the wear scar. A nonlinear ultrasonic wave mixing (NUWM) method is proposed for damage detection of alloy 690 tubes. A detection device is developed to implement the NUWM method. A nonlinear modulation index is used to assess the damage degree of alloy 690 tubes. Experimental results indicate that, for an impact load lower than 100 N and a cycle number smaller than 2 × 105, the tube damage is mainly in forms of the surface plastic deformation and delamination. For a higher impact load or a larger cycle number, the fatigue cracking is the main tube damage mode. With increasing the impact load or cycle number, the tube damage degree increases, leading to an increase of the nonlinear modulation index. Therefore, the NUWM method is effective for detecting and assessing the damage of alloy 690 tubes.

Evaluation of new target structure and recognition for point cloud registration and coordinates transformation of China’s large double-span bridge

In view of the limited precision of traditional point cloud registration methods in bridge engineering, as well as the lack of intuitive guidance for bridge construction control regarding relative coordinate relationships of point clouds, this study proposes a novel dual-purpose target for the total station and laser scanner, along with a corresponding algorithm. The scanning point cloud undergoes intensity filtering, clustering, planar denoising, contour extraction, centroid fitting, registration transformation, target recognition, registration, and coordinate transformation. Experimental results demonstrate that the proposed algorithm can accurately extract the centroid coordinates of the targets and effectively handle complex on-site conditions. The coordinate transformation achieves high precision, with an amplification error of only 2.1 mm at a distance of 500 m. The registration precision between planar and spherical targets is nearly identical, surpassing that of planar iterative and ICP algorithms. Application of the algorithm in the context of China’s large double-span steel-tube concrete arch bridge scenario. it was found that the maximum deviation of the radius of the main chord tube was 10.8 mm, the maximum deviation of the distance from the center of the main chord tube was 8.3 mm, the average length of the merging opening was 775.0 mm, the maximum lateral deviation of the merging opening was 9.6 mm, and the maximum deviation of the height of merging opening was 25.2 mm. The results showed that no additional restraining measures were needed, and the smooth jointing could be realized only under a suitable temperature. Comparison with measurements obtained from the TS60 total station exhibits a close match, with a verification error within 3.9 mm, thereby meeting the precision requirements for construction control.

Hydroforming of double-layer Y-shaped tube controlled by a novel backward punch shape

PurposeA new backward punch shape was designed and used in the hydroforming process of double-layer Y-shaped tubes to achieve uniform wall thickness. This study focuses on the implementation and effectiveness of this novel punch shape.Design/methodology/approachA numerical simulation and experimental validation of the hydroforming process of double-layer Y-shaped tubes under various backward punch, replenishment ratios (left and right feed ratios) and internal pressure loading paths was performed using finite elements. During the hydroforming process, an analysis was made on the distribution of stress, strain and wall thickness in both the inner and outer layers of the Y-shaped conduit.FindingsThe novel backward punch parallel to the main tube has been found to improve the distribution of wall thickness in Y-shaped tubes. By controlling the feeding ratio and modifying the loading path of the internal pressure, it is possible to obtain the optimal forming part of the double-layer Y-shaped tube. The comparison between the simulation and experimental results of the double-layer Y-shaped tube formed under the optimal path indicates that the error is within 5% and the distribution of wall thickness is consistent.Originality/valueA novel backward punch technique is employed to control the hydroforming process in a Y-shaped tube. A study on hydroforming of double-layer Y-shaped tubes with asymmetric features and challenging forming conditions is being suggested.

Comparing the efficacy and safety of different thread-drawing surgery method for treating high complex anal fistula: a systematic review and network meta-analysis.

To evaluate the effect of different surgical methods in the treatment of high complex anal fistula by systematic review and network meta-analysis. Randomized controlled trials that met the inclusion criteria in PubMed, Cochrane Library, Embase, Web of Science, CBM, CNKI, WANFANG DATA, VIP were searched from the date of database construction to May 23, 2023. Among the 48 randomized controlled trials (RCTs), 4205 patients were included in the network meta-analysis. Incision thread-drawing counter-drainage procedure (ITCP) in improving the effective rate, the cure rate; reduce the recurrence rate, reduce the anal canal damage has a huge advantage. Directional line-hanging method (DLM) is optimal for safety and postoperative pain relief. Directional line-hanging method (ITSS) protect the optimal anal function after surgery. Sphincter preserving thread-hanging method (SPTM) has a significant advantage in accelerating wound healing time. Main tube incision combined with thread-hanging branch tube drainage (MIBD) is second only to incision thread-drawing counter-drainage procedure (ITCP) in improving effective rate, cure rate, reducing recurrence rate and reduce complication rate. In general, different thread-drawing surgery methods have good clinical effect for the treatment of high complex anal fistula. In general, these methods provide evidence-based medical evidence for early treatment in terms of improving clinical efficacy, relieving anal pain and reducing wound healing time. However, there are differences in the number of included literature studies, and further verification by large-sample, high-quality, multicenter RCTS is still needed in the next stage.

Experimental demonstration of high-temperature (>1000 °C) heat extraction from a moving-bed oxidation reactor for thermochemical energy storage

Previously developed reduction-oxidation (redox) thermochemical energy storage technologies must store their products at high temperatures, complicating handling and transportation. This work describes a countercurrent, tubular, moving bed oxidation reactor at laboratory scale that produces high grade heat and allows solids to enter and exit the system at ambient temperatures. The particles implemented in the system consist of a novel magnesium‑manganese-oxide material well-suited for thermochemical energy storage. Output heat is obtained via a separate extraction gas flow, which exits from the middle portion of the main reactor tube. With this design, reactor temperatures in excess of 1000 °C and extraction temperatures above 950 °C were achieved. Deviation between the two measurements is a result of extraction thermocouple placement and losses in the reactor extraction arm; improvements to these parameters would bring the extraction temperature closer to the bed temperature. The reactor produces enough energy via oxidation to sustain both heat extraction and continued chemical reaction. During one representative steady state experiment at a particle flow rate of 1.5 g/s, an average of 447 W was extracted from the reactor out of an estimated 1083 W of released chemical energy for a duration of 70 min. Among the four experiments, the maximum bench-scale oxidation reactor energy efficiency of 36.2% and corresponding round-trip efficiency of 13.7% considering both redox reactors were demonstrated. Characteristics of an ideal system are considered and future improvements are proposed.

Brenner Basistunnel, Baulos H41 Sillschlucht–Pfons: Herausforderungen aufbauend auf den Vorlosen im betroffenen Projektbereich

AbstractThe construction lot H41 Sill Gorge–Pfons is one of the biggest construction lots of the Brenner base tunnel and carries out the work on the Austrian side between Austria and Italy. It is situated between the Sill Gorge in Innsbruck and the small mountain village of Pfons. Here, tunnel excavation and inner lining concrete works are carried out based on existing caverns and tunnels made by previous construction lots E41, Sill Gorge and H33 Tulfes–Pfons. The construction lot H41 Sill Gorge–Pfons started in January 2022 with preparation works, and will take 80 months of continuous construction work to complete. All together about 22.5 km of main tubes, 38 bypasses and the remaining parts of the underground Innsbruck emergency station/stop will be excavated by the drill and blast method and by mechanised means (TBM). Additionally, concrete inner lining works will be executed partly alongside the excavation works. In the connection tunnels which are already finished and link the existing Innsbruck bypass with the new Brenner base tunnel, barrier walls are being erected and a new long‐distance water flushing system is being implemented. The limited surface areas in this mountainous region present a huge challenge for logistics and storage as well as on‐site operations for the execution of this complex underground construction lot.

A research on the converging process in a T-shape tube

A T-shape tube is an important structure in chemical engineering and other fields. This article utilizes the CFD method on python with a simplified Navier-Stokes equation to stimulate the converging process of different fluids and studies the influence of inflow speed, viscosity, density, diffusion coefficient, the diameter of the tube and the length of the tube on the transmission characteristics like pressure and flow field. The results indicate that the ratio of the velocity of the main tube to that of the branch, the diameter of tube AC and tube B is inversely related with mixing efficiency and that the increase of pipe length at outlet tube and the diffusion coefficient of fluid is positive to the well-distributed concentration of outflow. However, the density and viscosity of inflow seem to have little impact on the mixing process.

ZLDI-8 suppresses angiogenesis and vasculogenic mimicry in drug-resistant NSCLC in vitro and in vivo

AimsThe chemotherapy drugs for NSCLC often face the consequences of treatment failure due to acquired drug resistance. Tumor chemotherapy resistance is often accompanied by angiogenesis. Here, we aimed to investigate the effect and underlying mechanisms of ADAM-17 inhibitor ZLDI-8 we found before on angiogenesis and vasculogenic mimicry(VM) in drug-resistant NSCLC. Main methodsThe tube formation assay was used to evaluate angiogenesis and VM. Migration and invasion were assessed with transwell assays in the co-culture condition. To explore the underlying mechanisms of how ZLDI-8 inhibited tubes formation, ELISA assay and western blot assay were preformed. The effects of ZLDI-8 on angiogenesis in vivo were investigated in Matrigel plug, CAM and Rat aortic ring assays. Key findingsIn the present study, ZLDI-8 significantly inhibited the tube formation of human umbilical vein endothelial cells (HUVECs) in either normal medium or in tumor supernatants. Furthermore, ZLDI-8 also inhibited VM tubes formation of A549/Taxol cells. In the co-culture assay, the interaction between lung cancer cells and HUVECs promotes increased cell migration and invasion, while ZLDI-8 eliminates this promotion. Moreover, the VEGF secretion were decreased by ZLDI-8 and the expression of Notch1, Dll4, HIF1α and VEGF were inhibited by ZLDI-8. In addition, ZLDI-8 can inhibit blood vessel formation in the Matrigel plug, CAM and Rat aortic ring assays. SignificanceZLDI-8 inhibits angiogenesis and VM in drug-resistant NSCLC through suppressing Notch1-HIF1α-VEGF signaling pathway. This study lays the foundation for the discovery of drugs that inhibit angiogenesis and VM in drug resistant NSCLC.

Design of heat exchanger for producing nickel ferrite (NiFe2O4) nanoparticles using coprecipitation method

This study examines the design of a heat exchanger (HE) in the production process of nickel ferrite (NiFe2O4) nanoparticles using the coprecipitation method by determining the shell and tube heat exchanger. The Microsoft Excel application is used as a manual calculating machine to facilitate the analysis of heat exchanger (HE) data calculations. The research flowchart starts with a literature study, preparation of tools and materials for design, calculation of the main shell and tube components, and then fabrication. Based on the calculation results, the design specification data for a shell and tube heat exchanger has a shell diameter of 0.032 m, a shell length of 4.267 mm, a thickness of 0.002 m with an initial heat transfer rate (Q) of 460130 W resulting in a heat transfer efficiency of 95.706% and an NTU of 6.165. The high effectiveness value makes the design of the one shell and tube type turbulent flow heat exchanger (HE) considered to have met the standards of high effectiveness and good performance. The design and design process is complete if the device functions properly. This study can be used as a reference for researchers in designing heat exchangers during production to make them more effective, reliable, and economical.

Numerical modeling of generalized Newtonian fluids flow in S-type geometry of bypass

This paper deals with a numerical simulation of the blood flow in bypass geometry, which consists of a main tube with a narrowing and its bridging by a bypass. Two different geometries of the bypass are considered, namely the classical bypass of the narrowed place and the second variant is the so-called S-type bypass. The optimal value of the connection angle of the bypass graft to the main channel is the subject of numerical testing in this work. Attention is focused on the values between 45 and 60 degrees. For the blood flow three relevant models are considered, namely Newtonian, Carreau and Power Law models. The numerical results are obtained using OpenFOAM and they are compared for all the considered types of geometry and for all values of the bypass connection angle and selected rheological viscosity models.