Double Tube Research Articles

Comparative Analysis of the Performance of the Thermal Pasteurization System Using Ohmic Heating Method with an Electric Heater on Mango Puree

This study explains the comparative analysis of performance in the thermal pasteurization system of the ohmic heating method with the electric heater in mango puree. The goal is to find out which thermal pasteurization method is better and more efficient. The method used for this study is to compare the two thermal pasteurization methods from the performance obtained, heating time, electrical power and electricity consumption costs. In the pasteurization process, the product is heated not exceeding 70 oC in the ohmic tube with an electric current on an electrode with a thickness of 4 mm attached to the end of the ohmic tube, while pasteurization of the product electric heater is heated in a double jacket tube equipped with an electric heater. The results of the analysis were obtained for the ohmic heating method the efficiency value was 78%, while for the method with an electric heater the efficiency value was 4%, the heating time of the ohmic heating method is 555 seconds, while the heating time of the electric heater method is 1500 seconds, for electric power in the ohmic heating method is 224.59 watts, while in the electric heater method an electric power of 1730.2 watts is obtained, and the cost of electricity consumption of the ohmic heating method is Rp.1,498.33,-/month, while the electric heater method costs electricity consumption of Rp.31,407.26,-/month.

Evaluation of tumor microvasculature with 3D ultrasound localization microscopy based on 2D matrix array.

Evaluation of tumor microvascular morphology is of great significance in tumor diagnosis, therapeutic effect prediction, and surgical planning. Recently, two-dimensional ultrasound localization microscopy (2DULM) has demonstrated its superiority in the field of microvascular imaging. However, it suffers from planar dependence and is unintuitive. We propose a novel three-dimensional ultrasound localization microscopy (3DULM) to avoid these limitations. We investigated 3DULM based on a 2D array for tumor microvascular imaging. After intravenous injection of contrast agents, all elements of the 2D array transmit and receive signals to ensure a high and stable frame rate. Microbubble signal extraction, filtering, positioning, tracking, and other processing were used to obtain a 3D vascular map, flow velocity, and flow direction. To verify the effectiveness of 3DULM, it was validated on double helix tubes and rabbit VX2 tumors. Cisplatin was used to verify the ability of 3DULM to detect microvascular changes during tumor treatment. In vitro, the sizes measured by 3DULM at 3mm and 13mm were 178 and 182 , respectively. In the rabbit tumors, we acquired 9000 volumes to reveal vessels about 30 in diameter, which surpasses the diffraction limit of ultrasound in traditional ultrasound imaging, and the results matched with micro-angiography. In addition, there were significant changes in vascular density and curvature between the treatment and control groups. The effectiveness of 3DULM was verified in vitro and in vivo. Hence, 3DULM may have potential applications in tumor diagnosis, tumor treatment evaluation, surgical protocol guidance, and cardiovascular disease. 3D ultrasound localization microscopy is highly sensitive to microvascular changes; thus, it has clinical potential for tumor diagnosis and treatment evaluation. • 3D ultrasound localization microscopy is demonstrated on double helix tubes and rabbit VX2 tumors. • 3D ultrasound localization microscopy can reveal vessels about 30 in diameter-far smaller than traditional ultrasound. • This form of imaging has potential applications in tumor diagnosis, tumor treatment evaluation, surgical protocol guidance, and cardiovascular disease.

Ten-year experience of whole lung lavage in pediatric Pulmonary Alveolar Proteinosis.

Pulmonary Alveolar Proteinosis (PAP) is extremely rare and can be caused by hereditary dysfunction of the granulocyte macrophage colony-stimulating factor receptor (GM-CSF) receptor, autoantibodies against GM-CSF, or other diseases leading to alveolar macrophage (AM) dysfunction. This leads to protein accumulation in the lung and severe dyspnea and hypoxemia. Whole lung lavage (WLL) is the first line treatment strategy. Here, we present data from more than ten years of WLL practice in pediatric PAP. WLL performed by the use of a single lumen or double lumen tube (SLT vs. DLT) were compared for technical features, procedure time, and adverse events. A total of n=57 procedures in six PAP patients between 3.5 and 14.3 years of age were performed. SLT based WLL in smaller children was associated with comparable rates of adverse events but with longer intervention times and postprocedural intensive care treatment when compared to DLT based procedures. Our data shows that WLL is feasible even in small children. DLT based WLL seems to be more effective, and our data supports the notion that it should be considered as early as possible in pediatric PAP. WLL lavage is possible in small PAP patients but should performed in close interdisciplinary cooperation and with age appropriate protocols.

A Computational Study for Evaluating the Performance of Twisted Double Tube Heat Exchangers Fitted with Twisted Tape

Twisted double-tube heat exchangers are promising in improving the heat transfer efficiency on the tube side, decreasing the pressure drop on the shell side, and reducing the size of the equipment. Although offering immense potential, examining heat transfer enhancement techniques inside a heat exchanger. In this study, The thermal-hydraulic characteristics of twisted double-tube heat exchangers fitted with twisted tape inserted have been numerically studied. The Naiver-stokes, energy, and turbulence equations were used to model the fluid flow and heat transfer while the turbulence was with a k- ε model. ANSYS Fluent 23.1 was used to solve the governing equations. The effect of major design elements such as mass flow rate, varied pitches of twisted double tubes and twisted tape inserts was investigated. The hot water was used in the inner tube and the cold water in the outer tube to create a counter-flow apparatus. The Length of the heat exchanger was 1 meter, and the outer and inner diameter was 0.054 and 0.018 m respectively. The thickness of the two tubes was 0.004 m. The twisted ratio of the tubes was tested for =5, 10, and 15 while the twist ratio of the tape was 4, 6, and 8. The findings demonstrated that the utilization of a double twisted tube heat exchanger with a twisted tape insert resulted in enhanced heat transfer in comparison to a plain tube heat exchanger. The numerical analysis revealed that as the twisting ratio drops, the Nusselt number, pressure drop, and overall heat transfer coefficient increase.

Behavior of concrete-filled double steel tube stub columns under partial compression

This paper reports the investigation on the behavior of stub columns having two nested steel tubes filled with concrete, abbreviated as CFDST, consisting of core concrete, inner and outer steel section and sandwich concrete. A total of twenty-seven stub columns were fabricated and tested. The experimental parameters included the wall thickness of the outer steel tube, strength grade of the concrete, ratio of the partial compressive area and the cross-sectional shape of the bearing plate. The typical failure modes, load-displacement relationships, and stress-strain relationships were studied. The results showed that outward bulging of the upper end of the outer steel tube occurred for the CFDST columns, and the degree and extent of bulging increased with the ratio of the partial compressive area. The bearing capacity of the columns loaded on the partial compressive area increased with the wall thickness of the outer steel tube and concrete strength. When the wall thickness of the outer steel tube increased, the partial bearing capacity increased by 25.3% on average. Reduction of the ratio of the partial compressive area improved the compressive bearing capacity. However, the shape of the bearing plate had a minor effect of the bearing capacity. Based on the experimental results, the FEM model was developed for analyzing the bearing capacity of the CFST and CFDST columns. The results of the analyses were found consistent with the experimental results.

Helical-shaped double wall tubes solution for the breeding zone cooling in the WCLL breeding blanket

Helical-shaped double wall tubes solution for the breeding zone cooling in the WCLL breeding blanket

Numerical investigation on Double Tube Counter Flow Heat Exchanger

In the current study, the investigation of heat transfer and fluid flow Characteristics of Pure water when pass through a double tube heat exchanger (DTHX). this investigation has been conducted across various Reynolds Number to gain insights into their performance also conducted a computational fluid dynamics (CFD) simulation using the ANSYS-FLUENT 22 R1 software. Result obtained was validated by comparing to empirical correlation data found in the existing literature. The investigation considered various operating variable as Reynolds Number and temperature across the inner, and outer tubes. Specifically, the Reynolds Number of a range of 2500 to 5500 at 333 K, and 2500 at 303 K for the respective tubes. Key findings are that friction factor is increase by 6.38% as compared to correlation (Blasius) in existing literature. And Nusselt number (Nu) increase by 40.84% as compared to correlation at the Reynolds Number (Re) of 2500. The heat transfer coefficients (hi) were increased by 8.30% as compared to existing literature.

Effective Troubleshooting of EZ-Blocker™ Endobronchial Blocker Insertion in Minimally Invasive CABG Surgery: A Case Series

EZ-Blocker™ is a specially designed semi-rigid Y-shaped Bronchial Blocker (BB) containing two inflatable cuffs. The difficulties and challenges encountered while inserting the Rusch EZ-Blocker™ (Teleflex Life Sciences Ltd., Athlone, Ireland) for isolating the left lung in Minimally Invasive Coronary Artery Bypass Graft (MICS CABG) surgery are numerous and varied. The present case series describes 28 different patients (out of 102 patients with attempted EZ-Blocker™) who faced various difficulties and technical problems while introducing the EZ-Blocker™ and how troubleshooting was performed in those cases with different manoeuvres. The difficulties in inserting the EZ-Blocker™ were due to a variety of reasons such as inadequate space between the carina and bronchus, a prominent right main bronchus at an acute angle compared to the obtuse angle of the left main bronchus, a compressed left main bronchus, deviation of the airway and a deep posterior bronchus. The manoeuvres used to overcome these challenges included controlled pulling of the endotracheal tube upwards, rotation of the head to the right-side with or without direct tracheal manual compression to the right-side, manual widening of the distal Y end of the EZ-Blocker™ and extension of the head in selected cases. Out of 102 attempted cases of EZ-Blocker™, difficulty (insertion time >90 seconds) was noted in 28 cases, which were managed with the different clinical manoeuvres mentioned above. However, in four other cases, the EZ-Blocker™ could not be introduced and the attempts failed. Although the EZ-Blocker™ is a safe and easy alternative to the Double Lumen Tube (DLT), it has not been widely used in India to date. The proposed manoeuvres will surely help clinicians use it more efficiently in cases where they encounter difficulty during insertion.

A Comparison of the Success of Intubation Using C-MAC D-Blade and McGrath MAC X3 Blade Videolaryngoscopes during Double Lumen Tube Insertion in One-Lung Ventilation: A Prospective, Randomized Clinical Trial

Objective: To compare the effects of C-MAC D-Blade and McGrath MAC X3 Blade videolaryngoscopes (VLs) during double lumen tube (DLT) insertion in one-lung ventilation (OLV) in patients who underwent chest surgery in terms of intubation durations, hemodynamic responses, and intubation-induced complications. Materials and methods: Fifty patients aged 18−65 years who were scheduled for OLV were included in this study. The patients were divided randomly into two groups: a Storz C-MAC D-Blade VL group (C-MAC group, n = 25) and a McGrath MAC X3 Blade VL group (McGrath group, n = 25). The results of a preoperative airway assessment, number of intubation attempts and incidence of success at the first attempt, glottic view times, intubation times, Cormack−Lehane scores, percentage of glottic opening (POGO) scores, ease of intubation, comorbidities, hemodynamic responses, and adverse intubation-related events were recorded. Results: The demographic characteristics and comorbidities of both groups were similar. The intubation characteristics of both groups were similar in terms of Cormack−Lehane scores, thyromental and intergingival distances, and POGO scores. In the C-MAC group, the glottic view times (p = 0.001) and intubation times (p = 0.001) were significantly shorter than those in the McGrath group. As shown by ease of intubation scores, ease of intubation in the C-MAC group was significantly better than that in the McGrath group (p = 0.001). All the patients in the C-MAC group were intubated at the first attempt, without a statistically significant difference. The two groups were similar with respect to intubation-related complications and hemodynamic responses (mean arterial pressure [MAP] and heart rate [HR]). Conclusion: We conclude that the C-MAC D-Blade VL is more beneficial for airway management due to shorter glottic view and intubation times, high success rates at the first attempt, and ease of intubation in patients intubated with a DLT in OLV.

INSIGHT INTO METAL FOAM DOUBLE TUBE HEAT EXCHANGER: SIGNIFICANCE OF PORE DENSITY, PRESSURE DROP CHARACTERISTICS, AND PERFORMANCE ANALYSIS

This study investigates the integration of metal foam heat exchangers into solar flat plate collectors to enhance their thermal performance, addressing a critical need for efficient solar energy utilization. The primary aim is to comprehensively analyze the thermal and fluid flow behavior within this integrated system using numerical simulations conducted with ANSYS Fluent v2021, with water as the working fluid to emulate real-world conditions. Three types of metal foam materials, nickel, copper, and aluminum, with varying porosities (0.80 to 0.90) and pore densities (10 to 30) are considered, and the simulation results are rigorously validated against experimental data. In experimental trials, a nickel metal foam with a porosity of 0.90 and a pore density of 10 pores per inch (PPI) is inserted into the double tube heat exchanger's annular space, and measurements of temperature and pressure drop are collected both with and without the metal foam. The research employs Reynolds-averaged Navier-Stokes (RANS) equations coupled with the k-epsilon model to simulate fluid flow and heat transfer phenomena, treating the metal foam heat exchanger as a porous medium due to its complex geometry. The study's major conclusion is the identification of an optimal metal foam configuration that significantly enhances thermal performance in solar thermal applications. This conclusion is grounded in a thorough evaluation of performance criteria and parameters. Additionally, the research provides valuable insights for engineering design and optimization, ultimately advancing the development of more efficient and sustainable solar thermal systems, which is of paramount significance in the pursuit of cleaner and more sustainable energy sources.

Improving Thermo-Hydraulic Performance with Varying Concentrations of Alumina Nanofluids: A Numerical Investigation

In the current study, the investigation of heat transfer and fluid flow Characteristics of Pure water when pass through a double tube heat exchanger (DTHX). This investigation has been conducted across various Reynolds Number to gain insights into their performance also conducted a computational fluid dynamics (CFD) simulation using the ANSYS-FLUENT 22 R1 software. The study employed mathematical models and thermophysical properties of nanofluids and water, which were sourced from existing literature. The analysis focused on comparing pure water, 1% Al2O3/H2O nanofluids. The investigation considered various operating variable as Reynolds Number and temperature across the inner, and outer tubes. Specifically, the Reynolds Number of a range of 2500 to 5500 at 80°C, and 2500 at 15°C for the respective tubes. Key findings are that friction factor for pure water, 1% alumina nf, 2% alumina nf, and 3% alumina nf is increased by 4.61%,11.42%,15.06% and 16.21% as compared to Gnielinski correlation in existing literature at a Reynolds Number of 2500 and this increase in friction factor is 5.66%, 13.79%, 18.03% and 19.61% respectively at Reynolds number of 5500. Nusselt number (Nu) for pure water, 1% alumina nf, 2% alumina nf, and 3% alumina nf is increased by 24.92%, 50.04%, 59.90% and 64.31% as compared to Gnielinski correlation in existing literature at a Reynolds Number of 2500 and this increase is 10.84%, 28.68%, 35.31% and 41.55% respectively at Reynolds number of 5500. The heat transfer coefficients (hi) for pure water, 1% alumina nf, 2% alumina nf, and 3% alumina nf is increased by 3.17%, 7.29%, 8.49% and 8.94% as compared to Gnielinski correlation in existing literature at a Reynolds Number of 2500 and this increase is 8.04%, 18.49%, 21.54% and 22.64% respectively at Reynolds number of 5500.

Performance Simulation of a Double Tube Heat Exchanger Based on Different Nanofluids by Aspen Plus

Performance Simulation of a Double Tube Heat Exchanger Based on Different Nanofluids by Aspen Plus

CFD Study on Heat Transfer in Hybrid Nanofluid with Coil Controller in Double Tube Heat Exchanger

Abstract: Heat exchanger that heats up to two or more processing fluids. Heat exchangers have a range of domestic and commercial applications. Use in steam plants, manufacturing plants, heat and air conditioning facilities, transportation, and cooling systems. Through analysis, Ordinarily, the presence of Cu+Al2O3 nanoparticles in the base fluid increases the properties of convective heat transfer and is thus more efficient than Al2O3 nanoparticles (at a steady concentration of volume). The findings revealed that the average heat transfer coefficient increases in line with the Reynolds number. Analysis has shown that the average thermal transfer coefficient value for hybrid nanofluid is 12 percent greater than the average for a single nanofluid. In the case of hybrid nanofluid compared to Mono nanofluid, the value of Nusselt is 18 per cent higher.

Design and performance optimization of a novel zigzag channeled solar photovoltaic thermal system: Numerical investigation and parametric analysis

In order to overcome the drawbacks of traditional photovoltaic thermal systems, including their limited thermal power, low thermal exergy, and heat transfer fluid outlet temperature, it becomes essential to explore the optimal design configuration of the system for maximization both electricity and domestic hot water generation. Therefore, a detailed numerical modeling and comparative performance analysis on a solar photovoltaic thermal collector (PVT) are conducted under two novel structures of the cooling channels. The first system is a reference PVT collector with a classical straight zigzag-plated tube cooling channel (Case A), while the second PVT system proposes an innovative design of flow cooling channel which is divided into three equal zigzag-plated tube sections (Case B). Each section is also split into three double pass tubes and has a separate inlet and outlet in a staggered manner corresponding to the section that precedes and follows it. The two proposed PVT structures are investigated through computational fluid dynamic simulation under solar radiation values ranging from 200 to 1000 W/m2 and coolant flow rates varying between 0.001 and 0.005 kg/s using both water and air as coolant. The obtained results confirm the significant potential of the modified configuration (Case B) that yielded an improvement in the thermal efficiency by 7.23% and 15.75% for water-PVT and air-PVT system, respectively, over the reference PVT system (Case A). Also, the modified configuration (Case B) yielded an enhancement in the electrical efficiency by 4.0% and 4.6% for water-PVT and air-PVT systems, respectively. It can be concluded that dividing the cooling channel area into equally mini zigzag plate tube-shaped sections with multiple reciprocal entrances is regarded a feasible configuration for augmenting the performance of PVT collectors and maintaining a uniform coolant flow and reduced temperature distribution over the entire panel.

Study on seismic behavior of prefabricated shear walls with steel double tube connections

The joints are crucial for influencing the overall mechanical performance of precast shear wall constructions under seismic actions. The existing joint connections are complex and not efficient enough. To maximize the potential of prefabricated structures, this study proposed innovative prefabricated shear walls with steel double tube connections. Two pseudo-static tests were conducted to investigate the influence of axial compression ratio on the seismic behavior of the innovative shear walls. The failure modes were all bending failures, and it had been discovered that increasing the axial compression ratio can improve the carrying capacity and energy dissipation capacity. Seven models with different axial pressure ratios were established to conduct nonlinear finite element analysis. The result showed that as the axial compression ratios raised, the carrying capacity and stiffness of the models increased, but the decreasing trend of force–displacement curves were also more distinct. Therefore the recommended axial pressure ratio of the models did not exceed 0.4. Finally, the calculation method of the loading capacity of novel shear walls was proposed, which provided the basis for the design of innovative shear walls.

Improving the thermal performance of the heat exchanger through simultaneous utilization of novel magnetic turbulators and helical coil wire turbulators

In this study, the effect of simultaneously using two active and passive methods, namely the magnetic turbulator and the helical coil wire (HCW) turbulator, on the hydrothermal parameters of a double tube heat exchanger is being evaluated for the first time. The results are also being compared with those of a simple heat exchanger, a heat exchanger equipped with a magnetic turbulator, and a heat exchanger with a HCW turbulator insert. Finally, the most optimal option is selected using TEF. Tests have been conducted using different pitch ratios of the HCW turbulator (ranging from 2.5 to 10) and fluid flow rates (ranging from 0.5 to 4 l/min). According to the results, the usage of the HCW turbulator, magnetic turbulator, and the simultaneous use of both turbulators increases heat transfer by 237 %, 262 %, and 491 %, respectively. Additionally, the pressure drop in the presence of these two methods is 3.8 times that of a simple heat exchanger. Furthermore, with the help of TEF, the heat exchanger armed with both turbulators is chosen as the optimal option, achieving a TEF of 3.78.

MT58 Implications of VivaSight-DL: Procedural Impact of a Camera-Integrated Double Lumen Tube

MT58 Implications of VivaSight-DL: Procedural Impact of a Camera-Integrated Double Lumen Tube

First 15 Years of Assisted Reproductive Technology Using Washed Sperm in HIV-Positive Individuals Under Antiretroviral Therapy: Sweden's Nationwide Outcomes.

Antiretroviral therapy has made HIV a chronic infectious disease. In Sweden, assisted reproductive technologies using sperm washing were implemented in 2004 for treatment of all HIV-positive males in serodiscordant couples at Karolinska Hospital in Stockholm. This study aimed to assess efficacy and safety of this approach and to investigate the effect of antiretroviral regimens on sperm quality of men treated for HIV. The study included all HIV-positive men (n = 53) adherent to antiretroviral treatment, including nucleoside/nucleotide analog reverse-transcriptase inhibitors (NRTIs) combined with non-nucleoside reverse-transcriptase inhibitors (NNRTIs) in 22 cases, or with other medication in 31 cases wishing fertility treatment. Sperm was washed using gradient centrifugation with a double tube system, frozen and thawed. Thereafter, single spermatozoa were injected in oocytes by intracytoplasmic sperm injection (ICSI). Treatment outcomes were compared to those of hepatitis B virus (HBV)-seropositive men in serodiscordant couples (n = 56), undergoing similar sperm washing protocols and ICSI at the center. In total, 82 fresh and 39 frozen/thawed embryo transfer (FET) cycles were performed in discordant HIV couples and 92 fresh and 36 FET cycles in HBV. Fertilization rates (69.2% vs. 64.6%, p = 0.310), clinical pregnancy rates (39.2% vs. 32.6%, p = 0.378), and live birth rates (35.8% vs. 31.5%, p = 0.565) were similar between the groups and the cumulative results yielded similar outcomes with a live birth rate of 52.8% and 51.8% (p = 0.913), respectively. No post-wash sperm sample was found positive for HIV viral particles. No partner seroconversion or offspring infection was reported. NNRTI-treated men had significantly lower motile sperm concentration than non-NNRTI-treated patients (54.48% vs. 36.41%, p < 0001). This study showed that in vitro fertilization/ICSI treatment with sperm washing was safe in individuals compliant to antiretroviral treatment and the reproductive outcome was similar to that of HBV-positive men. The observed moderate negative impact on sperm motility of NNRTI regimens may be overcome by using ICSI.

Numerical Investigation of Concrete Filled Double Circular Steel Tube Columns Using CFD

Numerical Investigation of Concrete Filled Double Circular Steel Tube Columns Using CFD

Double nested dual-core negative curvature fiber polarization beam splitter

In this paper, a polarization beam splitter（PBS） based on double nested dual-core negative-curvature fiber (DNHC-NCF) is designed. Two hollow cores are constructed by eight double nested cladding tubes arranged at certain angles. The influences of structural parameters on the performances of the DNHC-NCF PBS have been studied by using the finite element method (FEM). According to the simulation results, the structure of the proposed DNHC-NCF PBS is optimized. The final results indicate that the length of the proposed DNHC-NCF PBS is 1.38 cm and the extinction ratio (ER) is less than −20 dB in the wavelength range of 1.48–1.80 µm (320 nm, covers S + C + L + U bands). Besides, the higher order mode extinction ratio (HOMER) in the wavelength range of 1.3–1.71 µm is greater than 100, showing good single-mode characteristic as well. It is believed that the proposed double nested dual-core negative curvature fiber polarization beam splitter will have important applications in the fields of optical communication system.