Average Tension Research Articles

The impact mechanisms of intermediate water depth on the coupled dynamic responses of large-capacity floating wind turbines

ABSTRACT The currently planned floating wind farms in China mostly have water depths in the intermediate range. Therefore, investigating the impact mechanisms of intermediate water depths on the coupled dynamic responses of floating wind turbines is of significant importance. In comparison to deep water, mooring systems in intermediate water depths are more prone to experiencing catenary shape loss and stiffness. The contribution of difference-frequency effects increases with decreasing water depth, resulting in a more substantial impact on low-frequency responses. The Full Quadratic Transfer Function (QTF) method accurately captures low-frequency responses. Placing clump weights in the bottom section of the mooring line effectively restricts the displacement range of floating turbines while maintaining average fairlead tensions at levels similar to the other two forms. On this basis, focusing on the most optimal mooring system performance, experiments were conducted to validate the coupled dynamic responses of floating wind turbines in intermediate water depths.

Experimental study of a semi-submersible floating wind turbine with aquaculture cages under combined wind and irregular waves

The coordinated and integrated development of multiple marine industries is conducive to achieving efficient utilization of the ocean. Here, a novel semi-submersible floating wind power platform integrated with aquaculture cages is proposed. Then, model tests of the innovative floating wind-aquaculture platform (FWAP) with scaling ratio of 1/40 are carried out. Four sea conditions (below rated, rated, cut out and 50-year sea states) and three incident angles of combined wind and waves (0 deg, 90 deg and 180 deg) are considered in the tests. Correspondingly, three typical motion responses of the FWAP, the acceleration response of the wind turbine and the representative mooring line tension are analyzed. The experimental results show that one obvious response peak is mainly found in the response amplitude operator (RAO) curves for the in-plane motion of the new FWAP, including surge, sway and yaw. While for out-of-plane motions including heave, roll and pitch, the RAO curves show two distinct response peaks. Notably, as the environmental conditions progress from below rated to rated, cut out, and finally to 50-year extreme sea state, the motion response of the FWAP becomes increasingly pronounced. Furthermore, the acceleration of the wind turbine under rated and cut out conditions is significantly large, which can be attributed to the effect of rotor rotation. While the maximum mooring line tension in the FWAP is observed at the 50-year sea state, the maximum average tension occurs at the rated condition. The response power spectra of the new FWAP reveal the presence of multiple frequency components. Additionally, the nets can act as an excited or damping effect on the motion of the FWAP, the acceleration of the wind turbine and the mooring line system, depending on the variation of the sea conditions or the incident angle. This study can provide reference for the design improvement and engineering application of such new FWAP.

A technological solution to child safety seat errors: Efficacy of the cellular car seat

Objective Although child safety seats are highly effective in preventing injuries, they are frequently misused. Experts have identified two leading “critical misuses”: (1) loose harness straps and (2) loose vehicle attachment at the base. We designed an innovative child safety seat system that educates, instructs, and alarms participants of safety seat errors. The system includes both the Cellular Car Seat (CCS) smartphone app and a network of car seat sensors. Our objective was to determine if CCS system users had fewer child safety seat misuses than users with a child safety seat manual alone. Methods During the study visit, 92 participants completed three safety seat scenarios using a mock vehicle setup, test doll, and a convertible child safety seat: A) fully install a convertible safety seat, B) recognizing/correcting loose harness straps in a seat with intentionally loose straps, and C) recognizing/correcting loose attachment to the vehicle seat at the base in a seat with intentionally loose attachment. Intervention participants (n = 46) were asked to use the CCS app during each scenario and control participants (n = 46) were given only the paper child safety seat manual. For each scenario, researchers determined errors/misuses present at the end of the scenario, time to complete scenario, and tension achieved on the harness straps (collected via load cell). Results Compared with controls, intervention participants had significantly fewer errors and higher average harness tensions for all three scenarios; furthermore, a greater portion achieved a harness tension of 4 newtons. During Scenario A, the rate of loose harness strap errors was more than three times higher for controls and loose base attachment errors almost six times higher. We observed similar trends in Scenario B, with harness strap errors more than double for controls. In Scenario C, the rates of both critical misuse errors were four times higher for controls compared to the intervention group. Conclusions The innovative CCS system was highly effective at reducing child safety seat use errors, especially critical misuses. Reducing critical misuses will decrease injuries and fatalities among crash-involved children. The CCS system can alert families to everyday harnessing and installation errors and provide families and caregivers with ongoing, accessible support.

Knockout of EPO gene in blunt snout bream (Megalobrama amblycephala) by CRISPR/Cas9 reveals its roles in hypoxia-tolerance

Erythropoietin (EPO) is a glycoprotein hormone that plays a crucial role as a downstream regulator in the Hypoxia-inducible Factor (HIF) signaling pathway, mainly involved in the regulation of erythropoiesis. The open reading frame (ORF) of EPO in blunt snout bream (Megalobrama amblycephala, BSB) was 561 bp, encoding 186 amino acids. Phylogenetic analysis revealed it clusters with homologs in others teleost. We designed two target sites (targets 1, 2) to obtain gene knockout mutants, with the mature mRNA sequence of EPO that were located in exon 2, exon 3, respectively. The mutation efficiency of targets 1, 2 was 19.60%, 24.22%, respectively, both containing 6 mutation types. F1EPO+/− mutants with the same mutation type were screened, and select F2EPO−/− mutants after mating. At the age of five months, EPO−/− fish demonstrated a significant (p < 0.05) increase in the average oxygen tension threshold for the loss of equilibrium (LOEcrit) and the shedding degree of interlamellar cell masses (ILCM), whereas a significant (p < 0.05) decrease was observed in the number of red blood cells (RBC) and the concentration of hemoglobin (Hb) under hypoxia conditions, in comparison to the control group. Notably, injection of EPO mRNA rescued the downregulation of EPO expression in EPO−/− mutant, and overexpression of the EPO gene did not disturb the normal development of BSB embryos. These findings provide new insights into the potential for applying CRISPR/Cas9 in other aquaculture fish species and the breeding of hypoxia-tolerant BSB.

Simulation and experimental study on amphiphilic modified graphene oxide for EOR

The application of nanosheet in enhanced oil recovery (EOR) offers a practical approach to resolving some surface-related problems. In this study, theoretical calculation and experiment were combined to study the interfacial behavior and mechanism of amphiphilic modified graphene oxide. Octadecyl amine and aspartic acid were successfully grafted onto graphene oxide nanosheets by starch template method. The stability of the modified structure was verified by IR, XRD and SEM. The change of microstructure in molecular simulation can enhance the understanding of the structure of amphiphilic modified nanosheets under SEM. The contact angle experiment directly shows its amphiphilicity, which shows that the contact angle of hydrophilic surface is 34.6° and that of hydrophobic surface is 103.5°. The interfacial elasticity experiment shows that the interfacial film formed by synthetic GOTA has certain elasticity. When the concentration increases, the interfacial film formed in the adsorption process can effectively separate the oil and water phases. Based on the interfacial tension value, the ability of graphene oxide and modified graphene oxide with different concentrations to reduce the interfacial tension between distilled water and diesel oil was investigated successively. The mechanism of GOTA action was explained from the aspects of molecular structure and energy by molecular simulation. The results show that the interfacial tension fluctuates around 16 mN/m when the GOTA concentration is 0.005%, and the average interfacial tension is 17.48 mN/m when the GOTA concentration (molecular number percentage) is 0.004% in the simulation process, which is highly consistent. Further studies have shown that the interface formation energy of the system is significantly reduced after the addition of zwitterionic surfactants, and the interfacial tension can be reduced to 11.95 mN/m. With the help of molecular simulation, the adsorption mechanism of GOTA on the interface is explained from the aspects of microstructure change, interaction energy, cohesion energy, interface density and conformation. The adjustment of these interactions will directly affect the oil-water interface morphology and interfacial tension.

An all-position type control strategy of the haptic interactive virtual training system based on cable-driven

The virtual microgravity training system based on cable drive usually uses a force-position hybrid control strategy which has following problems: the force control method is sensitive to load disturbances, variable stiffness characteristics of cables reduce the control accuracy of PID controllers, and the expected tension fluctuations are large. These will affect the control accuracy, and further affect the tactile sensation and training effectiveness of astronauts. For the above problems, an all-position type control strategy is proposed to improve the system control accuracy. This strategy uses a compliant control method. In this method, elastic elements are connected in cables, the conversion model of tension and displacement is established, and the tension control is realized by the displacement control which has characteristics of high control accuracy and strong resistance to load disturbance. The PID controller is replaced by the active disturbance rejection controller. In this controller, the tracking differentiator is used to reduce high frequency noises of the input signal, and the extended state observer is used to estimate and compensate the error caused by the change of the cable stiffness. A tension distribution method is designed to make expected cable tensions approach the average tension to reduce the tension fluctuation. The experimental results show that compared with the force-position hybrid control strategy, the all-position type control strategy reduces the tension error and speed error by about 51% and 33% respectively.

Density, Surface Tension, and Viscosity of Molten Ni‐Based Superalloys Using the Maximum Bubble Pressure and Oscillating Crucible Methods

Accurate data on the high‐temperature thermophysical properties, which are density, surface tension, and viscosity, are indispensable for performing high‐precision casting simulations of Ni‐based superalloys. Viscosity is the most important thermophysical property for thermofluidic analysis. However, measuring the viscosity of an alloy, which is lower than that of molten glass, is difficult, and experimental viscosity data are limited. Herein, the density of Ni‐based superalloys is measured using the maximum bubble pressure (MBP) method to determine viscosity. The viscosity is evaluated using the oscillating crucible method. The surface tension is simultaneously measured using the MBP method. In these results, the average density values [kg m−3] of Alloy 65, Alloy 718, Alloy WA, and Alloy 720 are 7.52 × 103, 7.43 × 103, 7.82 × 103, and 7.52 × 103, respectively. The average surface tension values [N m−1] of Alloy 65, Alloy 718, Alloy WA, and Alloy 720 are 1.55, 1.54, 1.47, and 1.51, respectively. The fitting equations of the molten Ni‐based superalloys are as follows. 1) Alloy 65: ; 2) Alloy WA: ; 3) Alloy 720: ; 4) Alloy 718: .

Effect of oil phase type and lutein loading on emulsifying properties and in vitro digestion of mandarin peel pectin emulsions

Oil phases with different chain lengths and saturations were used to make mandarin peel pectin (MPP) emulsions with and without lutein loading. The outcomes demonstrated that the emulsifying, digesting characteristics and lutein bioaccessibility of MPP emulsion were related to the addition of lutein and also oil phase species. After lutein addition, the apparent viscosity of MPP emulsions and interfacial tension were dramatically decreased. MPP emulsions made from medium-chain triglyceride (MCT) oil displayed higher absolute zeta potential, free fatty acid release, and lutein bioaccessibility, while those made from long-chain triglyceride (LCT) (palm oil, corn oil, and olive oil) had higher volume average particle size and interfacial tension. The findings offered a theoretical foundation for effective delivery and release of lutein by pectin emulsion.

Pickering emulsions stabilized by chitosan-flaxseed gum-hyaluronic acid nanoparticles for controlled topical release of ferulic acid

Chitosan (CS) based nanoparticles (NPs) were fabricated via an ionic gelation reaction modified by flaxseed gum (FG) or sodium tripolyphosphate (STPP). The average particle size, morphology, interfacial tension, and wettability of NPs were characterized. The particle size of CS-STPP-HA (hyaluronic acid)-FA (ferulic acid) NPs and CS-FG-HA-FA NPs was 400.8 nm and 262.4 nm, respectively under the optimized conditions of CS/STPP = 5:1 (w/w) or CS/FG = 1:1 (v/v) with HA concentration of 0.25 mg/mL and FA dosage of 25 μM. FG acted as a good alternative for STPP to form particles with CS in stabilizing Pickering emulsion with an internal diacylglycerol (DAG) phase of 50–80 % (v/v). The complex nanoparticles had high surface activity and contact angle close to 90 °C, being able to tightly packed at the droplet surface. The emulsions had high thermal, ionic and oxidative stability. With the aid of moisturizing polysaccharides and DAG oil, the emulsions had a good sustained-release ability for FA with deeper penetration and retention into the dermis of the skin. Thus, FG and HA-based NPs serve as green vehicles for the fabrication of novel Pickering emulsions and possess great potential to be applied as a delivery system for lipophilic active agents in functional food and cosmetic products.

Study of psychosomatic disorders in adynamia among students and cyber addicts

Objective. To study psychosomatic health in adynamia in cyber addicts and students.Material and methods. 100 people at the stages 3-4 of cyber addiction underwent rehabilitation and reintegration into society, and 82% of them got employed. Surveys, research on autonomic balance, calculation of the health coefficient, and assessment of psycho-emotional state based on the characteristics of the HTP test, were conducted among 24 cyber addicts and 24 students.Results and discussion. The health coefficient of the cyber addicts averaged 2.38, while that of the students averaged The average emotional tension index is 10.53 for students and 10.63 for those with cyber addiction. Autonomic disorders were identified in the female subgroup of gamers using the Kerdo Students displayed normotonia. The Hildebrandt index for students averaged 4.51, while for those with cyber addiction it was 3.03. These indicators are within normal limits.Conclusion. The effectiveness of treatment methods for cyber addiction and the social rehabilitation of cyber addicts has been identified based on health coefficient A low level of this metric was observed in the control group. Students require such rehabilitation in the process of A comprehensive and informative set of tests has been selected to determine the psychosomatic health and adaptation of addicts and individuals who spend extended periods on the computer in a state of

Interference screw versus suture button fixation for tibialis anterior tendon transfer: a biomechanical analysis.

Tibialis anterior tendon (TAT) transfer to the lateral cuneiform is commonly utilized to treat dynamic supination for relapsed clubfoot deformity. Traditional suture button fixation (SBF) may lead to skin necrosis at the button/skin interface. While interference screw fixation (ISF) would mitigate this concern, this fixation method has not been investigated in clubfoot patients. This study aims to investigate the performance of ISF versus SBF for TAT transfer in a cadaveric model. Ten matched pairs of cadaveric feet were obtained. One of each matched specimen underwent TAT transfer to the lateral cuneiform using ISF and the other underwent TAT transfer using SBF. For each ISF specimen, the tension of the transferred TAT required to bring the ankle to neutral was measured. This tension was then applied to both matched specimens using an MTS machine. Tension dissipation was measured after a 20-minute interval. In specimens with SBF, a load cell was positioned between the plantar skin and suture button to determine plantar skin pressure at the time of initial tension application. Average tension necessary to achieve neutral dorsiflexion was 49.4 N. Average tension dissipation after 20 min was significantly less in the IFS group (20 N versus 23.6 N, P = 0.02). No fixation failures occurred in either group. Average plantar foot skin pressure was 196.5 mmHg at initial tension application, exceeding thresholds for tissue ischemia. ISF allows for tendon tensioning at forces beyond those expected to result in skin necrosis with SBF with less dissipation of tension over time.

Monolayer/Bilayer Equilibrium of Phospholipids in Gel or Liquid States: Interfacial Adsorption via Monomer or Liposome Diffusion?

Phospholipids (PLs) are widely used in the pharma industry and a better understanding of their behavior under different conditions is helpful for applications such as their use as medical transporters. The transition temperature Tm affects the lipid conformation and the interfacial tension between perfluoroperhydrophenanthrene (PFP) and an aqueous suspension of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), 1,2-distearoyl-sn-glycero-3-phosphatidylcholine (DSPC), as well as a mixture of these PLs with cholesterol. Interfacial tensions were measured with the Du Noüy ring at quasi-equilibrium; the area per molecule was calculated according to the Gibbsian approach and a time-dependent tension gradient. Results show that the time tε to reach quasi-equilibrium was shorter when the temperature was above Tm, indicating a faster adsorption process (tε,DPPC,36 °C = 48 h, tε,DPPC,48 °C = 24 h) for PL in the liquid crystalline state than in the gel state (T < Tm). In addition, concentration-dependent results of the interfacial tension revealed that above the respective Tm and at all concentrations c > 0.1 mM, the average minimum interfacial tension for DPPC and DSPC (14.1 mN/m and 15.3 mN/m) does not differ significantly between those two lipids. Equilibrium between monolayers and bilayers shows that for T < Tm, surface pressures ∏ ≈ 31 mN/m are reached while for T > Tm, ∏ ≈ 41 mN/m. Mixtures with cholesterol only reach ∏ ≤ 31 mN/m Tm, with no significant difference between the two PLs. The higher interfacial tension of the mixture indicates stabilization of the liposomal conformation in the aqueous phase by the addition of cholesterol. The high diffusion coefficients show that adsorption is mainly based on liposomes.

PNÖ-MEKANİK ARMÜR MAKİNASININ TASARIM VE İMALATI

The contents of the shed opening frames used in the weaving machines and the pneumatic connections used in the dobby mechanisms of the shedding cost were made. As a result of the weaving, a new dobby with low cost, easy to manufacture and maintain was designed and produced in weaving machines. In particular, you can run a system that can manufacture fabrics with minimized tensions in warp threads. After executing the cam and tracking design, the drive, select, and motion acquisition to the frames were fabricated and assembled. After seeing the precise adjustments of the mechanisms, they were automatically operated at different speeds. Optimum results have been achieved in the incoming tension values in the warp with the new generation pneu-mechanical dobby machine, which is one of the shedding devices used to create sheds in Bizim Study weaving machines and provides the movements of frames for this purpose. The average warp tension during the weaving process was 34.6 cN.

The shape of things to come: Axisymmetric drop shape analysis using deep learning

HypothesisIn the traditional approach to Axisymmetric Drop Shape Analysis (ADSA), the determination of surface tension or interfacial tension is constrained by computational speed and image quality. By implementing a machine learning-based approach, particularly using a convolutional neural network (CNN), it is posited that analysis of pendant drop images can be both faster and more accurate. ExperimentsA CNN model was trained and used to predict the surface tension of drop images. The performance of our CNN model was compared to the traditional ADSA, i.e. direct numerical integration, in terms of precision, computational speed, and robustness in dealing with images of varying quality. Additionally, the ability of the CNN model to predict other drop properties such as Volume and Surface Area was evaluated. FindingsOur CNN demonstrated a significant enhancement in experimental fit precision, predicting surface tension with an accuracy of (+/-) 1.22×10−1 mN/m and at a speed of 1.50 ms−1, outpacing the traditional method by more than 5×103 times. The model maintained an average surface tension error of 2.42×10−1 mN/m even for experimental images with challenges such as misalignment and poor focus. The CNN model also demonstrated showcased a high degree of accuracy in determining other drop properties.

The Effects of Variable Tension Forces on Exoskeletons’ Effectiveness

Exoskeletons are ergonomic devices that can support workers to improve performance and worker safety. This study created an apparatus that simulated a head-and-neck exoskeleton designed for surgeons to test the effects of varying tension forces on muscle activation (splenius capitis, splenius cervices, and erector spinae), body part discomfort, dexterity, cognition, and overall usability of the device. Eight participants were involved in twelve trials over two days and held static postures (looking down at 45° or 90°) for 20 minutes with 10-minute breaks between trials. Six trials utilized tension forces, which were recorded every two minutes and then averaged for each trial. A bivariate regression analysis ( on each metric vs. average tension forces demonstrated that increasing tension forces led to decreased muscle activity of the left splenius capitis, change in general body pain, change in neck discomfort, and the rate of discomfort developing, and improved usability scores.

Mechanical properties of a bioabsorbable magnesium interference screw for anterior cruciate ligament reconstruction in various testing bone materials

Tears of the anterior cruciate ligament (ACL) negatively impact the stability and kinematics of the knee. Interference screws (ISs) are used for graft fixation in ACL reconstruction and provide sufficient fixation strength to withstand the patients' activities during the graft-to-bone integration process. Magnesium is a novel material used to manufacture IS given its strength and bioabsorbability. In previous studies, the selected magnesium IS design showed a better fixation performance in comparison to the conventional IS design due to its shape design and surface condition. In this study, bioabsorbable magnesium ISs were tested for their insertion (insertion torque and a number of turns to implement the IS) and fixation performance (pull-out and dynamic test). To obtain a reliable initial assessment of IS performance, ISs were implanted in 15 per cubic foot (PCF) Sawbones polyurethane foam blocks, Sawbones biomechanical tibia models with 17 PCF foam cores, and human cadaveric tibiae. Porcine tendons were used in the foam block pull-out test, and nylon ropes were used in all other test setups to prevent influences of the ligament graft material itself. In the pull-out test, the graft was subjected to tensile stress at a rate of 6 mm/min. For the dynamic test, 1000 cycles between 0 and 200 N were performed, followed by a final pull-out test. After each test, the tunnel widening pattern was observed by measuring the aspect ratio of the tunnel at the insertion site. The insertion torque lies within the normal insertion torque of the ISs as well as the average ligament tension before the insertion. In the foam block setup, the nylon rope showed a higher pull-out force than the porcine tendon. The comparison of each setup using nylon rope for both pull-out and pull-out after the dynamic test showed no significant difference between the foam block and cadaver setup. However, all tibia model setup shows unexpectedly high pull-out force due to the influence of its cortical layer. There were no statistically significant differences in tunnel widening between foam block-porcine tendon and foam block-nylon rope constructs. The pull-out resistance of magnesium ISs falls within the typical ACL tension range during daily activities. Even though the test results of the magnesium ISs are different in each bone material, the magnesium IS shows adequate fixation ability and workability during insertion without material failure.

Measurement of Water Matriial Potential in the Soil Through Instrumented Tensiometers with Pressure Sensors and Puncture Device

Objective: The search for a practical and accessible solution for measuring water tension in the soil using tensiometers is fundamental for irrigation management, efficient use of water and increased profitability of irrigated crops. The objective of this study was to propose a technique based on the instrumentation of a tensiometer with a pressure sensor and a device for reading the sensor's response. Theoretical Frame: This study used the following main quotes as a theoretical basis: Freescale and NPX Semiconductors manufacturers of pressure sensors, Azevedo &amp; Silva for the soil water tension correction methodology and Van Genuchten to describe the relationship between soil water content and suction. Method: Pressure transducers with a range of 0-50 and 0-100 kPa were used, with an analog signal varying between 200 and 4700 mV, whose response was measured by a digital multimeter with the scale adjusted to V or mV. The transducer was adapted by attaching a hypodermic needle Nº 7/30 to the vacuum measurement inlet, leaving the other inlet free for the atmosphere. The transducer was powered by a 9 Vcc battery with rectified voltage to 5 Vcc through a specific integrated circuit for this function. The conversion of the transducer response signal in mV to voltage in kPa was performed using the response function informed by the manufacturer, reversing the order of the variables so that the voltage could be measured as a function of the output signal in mV. The system was used to measure the water tension in the soil of tensiometers installed in an area cultivated with tomatoes in a greenhouse during a complete cycle, functioning satisfactorily. Results and conclusions: During the experimental period, the water tension in the soil observed with the new tensiometer with pressure sensor and sensor response reading device ranged from 0.00 kPa (minimum tension) to 53.33 kPa (maximum tension) in the two soil layers. analyzed soil, while the average tension was 23.64 kPa in the 0-20 cm soil layer and 21.38 kPa in the 20-40 cm layer. Soil moisture obtained from soil water tension and soil water retention curve ranged from 0.11 (minimum) to 0.50 m3 m-3 (maximum) in both studied soil layers, while that the average soil moisture in the depth from 0 to 20 cm was 0.21 m3 m-3 and from 20 to 40 cm was 0.20 m3 m-3. The instrumented tensiometer with pressure sensor and sensor response reading device makes it possible to satisfactorily determine the matrix potential of water in the soil. The matriial tension data obtained with the new pressure sensor are consistent with reports in the literature as adequate to provide higher yields in tomato cultivation. The technique and instrumentation proposed in this study allows measuring the water tension in the soil, knowing the soil moisture and carrying out irrigation management, applying an irrigation depth according to the needs of the plants, making a more efficient use of water and providing water and electricity savings. Implications of the research: This study qualifies as being of great relevance for the purposes of the Department of Agronomic Engineering at the Universidade do Estado de Mato Grosso, Nova Mutum Campus, as well as for the entire academic and scientific community and rural producers interested in tensiometers to carry out a management of water from the soil and farm sustainably. Originality and value: The study sought to present to the academic, scientific and rural producers community a practical and accessible solution for measuring the water tension in the soil through tensiometers, thus providing current information on a new instrument for irrigation management, which makes it possible to carry out a more efficient use of water and increase the profitability of irrigated crops.

Experimental Study on Hydrodynamic Characteristics of Barge-Type Breakwaters under Different Mooring Methods

In this paper, a yacht project in Tingjiang Town, Mawei, Fujian, is suggested as an example of a barge type breakwater made out of scrap barges. The physical modelling of a two-dimensional flume wave test was carried out on a barge-type breakwater, focusing on the wave dissipation and anchor chain forces under two different mooring methods, the “crossed tilt” mooring and the “front and rear direct pull” mooring, with no change in the size of the breakwater. The test results show that the effect of wave elimination of the barge-type breakwater gradually decreases with the increase of wave elements under different mooring conditions, but the effect of wave elimination of the barge-type breakwater is significantly better under the “crossed tilt” mooring systems than under the “front and rear direct pull” mooring systems; the maximum tension of the anchor chain under the “inner eight” diagonal mooring method is significantly higher than that under the front and rear straight pulling mooring method. The maximum anchor chain tension under the “crossed tilt” mooring system is significantly greater than that under the fore and aft straight mooring method, while the average anchor chain tension does not change significantly under the two mooring methods.

Abstract 644: Angiogenic Blood Vessels Reconfigure/ Attenuate Hypoxic Tumor Microenvironments In A Quantitative In Vitro Model

Introduction: Angiogenesis is crucial in the spread of cancer cells, and hypoxic tumor microenvironment (TME) plays a vital role in its initiation. Hypoxia stimulates the release of pro-angiogenic factors, promoting the growth of new blood vessels towards the tumor, which further alters the TME. The variation of in vivo hypoxic TME have been studied recently. However, due to technical limitations such as highly invasive procedure, high cost, tedious process, and poor signal-to-noise ratio, it is challenging to perform quantitative oxygen sensing. Here we develop an advanced in vitro model directly investigating the interaction between a solid tumor and blood vessels for an extended period. Hypothesis: The angiogenic blood vessels can reconfigure and attenuate the hypoxic TME, which can be directly measured Methods: The model is built using a microfluidic device with a sealed microwell for 3D tumor spheroid culture (human colon cancer cell line, HCT116), and a microfluidic channel beneath the microwell for endothelium formation (human umbilical vein endothelial cell, HUVEC), connected by a small hole for interaction between the cell types. Oxygen sensitive fluorescence particles are distributed in the hydrogel matrix, and the widefield frequency domain fluorescence lifetime imaging microscopy (FD-FLIM) is exploited to reliably characterize the oxygen tension around the tumor spheroid with minimal sensitivity to ambient optical noise. Results: The oxygen tension of TME around the tumor spheroid within the distance of 0 to 0.7 mm rapidly decreases during tumor growth, from 15% at day 1 to less than 6% at day 14. The presence of endothelial cells slows down this decreasing rate and maintains it in a stable range, from 16% to 14%. The average oxygen tension difference between the two experiments, with and without co-culture of endothelial cells, is statistically significant after 5 days of observation (p&lt;0.01). Conclusions: We develop a quantitative in vitro method to study the hypoxic TME for its dynamic pattern and as a target for cancer treatment. By observing the effect of angiogenesis on it, this method can aid in exploring optimal cancer management strategies, such as chemotherapy, immunotherapy, tailored anti-angiogenic agents and other targeted therapies.

Analysis of Factors Affecting Strand Tension in Cable-Twisting Equipment and Method for Equilibrated Control

To address the issue of tension fluctuations and deviations among the strands during cable-twisting production, it is necessary to establish a relationship model between the centrifugal force, frictional force, and tension experienced by each strand in a single span range under the state of traveling and rotating. Considering the differences of strand alignment at the distribution reel, the effects of centrifugal force and friction on strand tension under different twisting-deflection paths and cylinder-traveling paths should be analyzed. In our study, different stress states of each strand were applied to simulate and verify the tension fluctuations and deviations of every strand under various traveling and deflection paths. The experimental results show that the increasing travel path of the strand cylinder will cause an increase in the average strand tension. Different deflection paths in the distribution reel will affect the range of the strand tension fluctuation. A sliding mode controller based on a discrete system was designed in MATLAB to control the tension fluctuation and deviation among the strands. The results indicated that this control method can effectively reduce the tension deviation between strands, and the average tension fluctuation range of each strand was reduced by 79.5%.