Cone Tube Research Articles

Anopheles gambiae s.s. resistance to pyrethroids and DDT in semi-urban and rural areas of the Moyen-Ogooué Province, Gabon

BackgroundPyrethroids are the main insecticides used in vector control for malaria. However, their extensive use in the impregnation of long-lasting insecticidal nets (LLINs) and indoor residual spraying has led to the development of resistance, threatening its success as a tool for malaria control. Baseline data prior to large scale distribution of LLINs are important for the implementation of efficient strategies. However, no data on the susceptibility of malaria vectors is available in the Moyen-Ogooué Province in Gabon. The aim of this study was to assess the susceptibility to pyrethroids and organochlorides of malaria vectors from a semi-urban and rural areas of the province and to determine the frequency of insecticide resistance genes.MethodsLarvae were collected from breeding sites in Lambaréné and Zilé and reared to adults. Three to five-day old female Anopheles gambiae sensu lato mosquitoes were used in cone tube assays following the WHO susceptibility tests protocol for adult mosquitoes. A subsample was molecularly identified using the SINE200 protocol and the frequency of Vgsc-1014 F and − 1014 S mutations were determined.ResultsAnopheles gambiae sensu stricto (s.s.) was the sole species present in both Lambaréné and Zilé. Mosquito populations from the two areas were resistant to pyrethroids and organochlorides. Resistance was more pronounced for permethrin and DDT with mortality lower than 7% for both insecticides in the two study areas. Mosquitoes were statistically more resistant (P < 0.0001) to deltamethrin in Lambaréné (51%) compared to Zilé (76%). All the mosquitoes tested were heterozygous or homozygous for the knockdown resistance (Kdr) mutations Vgsc-L1014F and Vgsc-L1014S with a higher proportion of Vgsc-L1014F homozygous in Lambaréné (76.7%) compared to Zilé (57.1%).ConclusionThis study provides evidence of widespread resistance to pyrethroids in An. gambiae s.s., the main malaria vector in the Moyen-Ogooué Province. Further investigation of the mechanisms underlining the resistance of An. gambiae s.s. to pyrethroids is needed to implement appropriate insecticide resistance management strategies.

Surface Temperature Distribution Aluminum Block with Cone Tube Profile Calculated Using ANSYS Fluent

Thermal Cycler is the main part of the Polymerase Chain Reaction (PCR), which becoming a gold standard for Covid-19 diagnosis. The virus multiplication in an order to a detectable concentration is done by placing the virus solution at a deterministic temperature cycle. The solution is placed in a small tube inserted in a temperature block. Temperature distribution of the thermal block is important to make all the tube with sample treated at the same at desired target temperature. Study on the thermal block made of aluminium 7075 was simulated using fluid dynamic finite element method. Heating and colling to the target temperature was done by providing heat source and heat absorber. The temperature distribution on the surface was mapped. The temperature gradient perpendicular to the heat source was calculated. Assuming the environment of the thermal block was still air, the heating and cooling speed at given heat source and heat removal were calculated using the model. The temperature gradient from the top surface to the bottom surface is less than 2.5°C. The temperature difference among point at the surface is less than 0.1°C.

Design and Optimization of Sensitivity Enhancement Package for MEMS-Based Thermal Acoustic Particle Velocity Sensor.

In this paper, small-sized acoustic horns, the sensitivity enhancement package for the MEMS-based thermal acoustic particle velocity sensor, have been designed and optimized. Four kinds of acoustic horns, including tube horn, double cone horn, double paradox horn, and exponential horn, were analyzed through numerical calculation. Considering both the amplification factor and effective length of amplification zone, a small-sized double cone horn with middle tube is designed and further optimized. A three-wire thermal acoustic particle velocity sensor was fabricated and packaged in the 3D printed double cone tube (DCT) horn. Experiment results show that an amplification factor of 6.63 at 600 Hz and 6.93 at 1 kHz was achieved. A good 8-shape directivity pattern was also obtained for the optimized DCT horn with the lateral inhibition ratio of 50.3 dB. No additional noise was introduced, demonstrating the DCT horn’s potential in improving the sensitivity of acoustic particle velocity sensors.

Buckling study on Two-Stage absorption energy coupler

A two-stage absorption energy structure composed of an expanding tube and a buffer has been conventionally applied to the couplers of the China Railway High-speed system. Previous investigations have revealed the energy-absorption characteristics of the couplers. However, in dynamic experiments, some of the couplers were found to buckle at the expansion cone. To analyse the buckling problem of the couplers, a simple theoretical model was established and verified via the finite element method (FEM) and experiments. The critical conditions for the couplers buckling and the bending strengths of the expansion tubes were studied. The results indicate that a slight initial misalignment between the expansion cone and outer tube can cause buckling of the couplers. Further, the stabilities of expansion tubes can be significantly improved by increasing the contact area of the expansion cone, reducing the length of expansion tubes, maintaining separation between the expansion cone and the midpoint of the couplers, and increasing the stiffness of expanding tubes. This study is expected to provide guidelines for solving the stability problems of long-stroke expansion tubes and advances the design of such expansion tubes.

Numerical Simulation and Parameter Study of Radial Forging of Conical Tube

The cone tube is an important part of the circuit connector, which has high requirements for its forming quality. In this paper, the cone tube is taken as the object, the finite element model is established, the radial forging process of the cone tube is simulated, the influence of process parameters such as axial feed and friction on the thickness of the cone tube is studied, and the influence law is analyzed, which has certain reference value for the analysis of the forming law of the radial forging.

Fabrication of the carbon fiber reinforced plastic (CFRP) cone tube through the laboratory-scale 3-axis winding machine

Filament winding process is one of the composite fabrication methods, which has relative lower manufacturing costs, higher efficiency and automation. It is commonly used to manufacture axisymmetric composite products, such as tubes, vessels, and domes, which is mainly used in aerospace, military and defense technology. However, it is a challenging task to fabricate a composite cone structure with the high winding angle through a laboratory-scale 3-axis winding machine. This paper aims to design and fabricate the carbon fiber reinforced plastic (CFRP) cone tube by using a low-cost filament winding machine. The cone mandrel was designed and prepared using additive printing technique. Dry and wet winding processes were conducted with yarn and 3K carbon fiber tow, respectively. The CFRP cone tube was successfully designed and fabricated with a winding angle of 75.11°±0.12°. It can be concluded that the wet winding process provides better winding quality and higher surface smoothness compared to the dry winding process. Moreover, the compressive modulus was 1.62 GPa, and the maximum compressive stress was 16.29 MPa under quasi-static compression loading.

Study of Heat Transfer and Pressure Drop Inside Helical Cone Tube

Study of Heat Transfer and Pressure Drop Inside Helical Cone Tube

Application to Artificial Skin of Double Cone Tube Made of Acrylic Resin Formed by Micro Stereolithography

Application to Artificial Skin of Double Cone Tube Made of Acrylic Resin Formed by Micro Stereolithography

A new endotracheal tube for infants – laboratory and clinical assessment: a preliminary study

Conventional endotracheal pediatric tubes offer high resistance due to their small diameters and relatively high flow during ventilation. Any increase of the diameter of the tube lumen decreases the airway resistance and subsequently, the work of breathing (WOB). We compared ventilation mechanics using a new, cone-shaped endotracheal tube of our design to the Cole and standard tubes. The study has been divided into three parts: (i) preliminary laboratory tests, (ii) in vitro study with infant lung model, and (iii) clinical study in infants. Flow resistance and WOB were compared, using standard, Cole (in experimental phase only) and cone tubes. We proved that inspiratory (Ri ) and expiratory (Re ) resistance, and WOB, were significantly lower in patients ventilated via a cone tube. Mean Ri decreased by 37%, compared with the baseline values, Re - by 35%, and total WOB - by 12%. The cone tube offers lower resistance to gas flow than the standard, used nowadays in clinical practice. It can be especially beneficial to spontaneously breathing patients reducing WOB and improving gas exchange.

AUDIO RADIATION TYPE REFLECTIVE SOUND BOX STRUCTURE

The present invention is to provide an audio radiation type reflective sound box structure, which comprises a hollow cone tube having a first end received in a box, a second end extended out of an opening of the box to form an inclined side wall, and at least one vent disposed adjacent to the first end. When a diaphragm of a speaker mounted on an inner side edge of the second end generates vibrations, compressed air in the hollow cone tube is pushed out of the opening through the vent, and then collides with the outer edge of the inclined side wall and is diffused toward a peripheral direction adjacent to a front side of the speaker along an extension direction of the inclined side wall. Thus, the sounds reflected by the box can be evenly transmitted to a peripheral environment adjacent to the front side of the speaker.

The Study on Force Behavior of Concrete Filled Steel Tube Lattice Wind Turbine Tower with Three Limb Columns

This paper refers to currently the 1.5MW cone tube type wind-driven generator tower, design the model of the concrete-filled steel tube wind turbine tower with three limb columns, and research on the force performance, such as the change of internal force, the process of failure, hysteretic behavior, bearing capacity, ductility and energy dissipation capacity by the pseudo-static experiment on the scale model of wind turbine tower. The study shows that the P- hysteretic curve of lattice concrete-filled steel tube wind-driven generator tower with three limb columns is asymmetric, relatively full “spindle” and the phenomenon of “knead shrink” is not obvious, which account for it has good force behavior and energy dissipation capacity. This kind of tower structure, of which the reverse bearing capacity is greater than the positive, and the reverse ductility coefficient is less than the positive, indicates that it’s reverse plastic deformation ability of the tower structure is weaker than it’s positive.

Application of CAD/CAM Technology in the Development and Lofting of Complex Sheet Metal Parts

For a development and lofting of complex sheet metal parts, the traditional work is hard and lack of accuracy. Using CAD/CAM to aid development and lofting needs neither lofting site nor mathematic models, but can achieve high quality and efficiency. The development and lofting of multi-tapered conical tube with 90º elbows as an example, the paper describes the methods of development and lofting of complex sheet metal parts based on CAD​/CAM technology, such as drawing view of four sections of tapered conical tube with 90º elbow, drawing graphic model and developed view of frustum conical tube, checking the coordination situation of each section oblique cone tube model, and blanking programming using CAXA wire EDM V2 software.

Single-phase heat transfer, friction, and fouling characteristics of three-dimensional cone roughness in tube flow

Abstract This paper reports heat transfer and friction characteristics of three tubes having a conical, three-dimensional roughness on the inner tube surface with water flow in the tube. The TC3 truncated cone tube has twice the cone area density as TC2 and provides a Nusselt number 3.74 times that of a plain tube. The h-value is 36% higher than TC2, but it has it has nearly 60% higher pressure drop. The three-dimensional roughness offers potential for considerably higher heat transfer enhancement (e.g., 50% higher) than is given by helical ridged tubes, such as the Turbo-B type. The two truncated cone tubes provide 14–20% higher h-value than the commercial Wolverine Turbo BIII tube. Further, they have both have approximately 5% higher efficiency index than Turbo BIII. Accelerated particular fouling data are also provided for 3-D tube TC3, and for helical-ribbed tubes. The results show that although the 3-D tube provided the highest heat transfer coefficient, relative to a plain tube (h/hp), it also had the highest asymptotic fouling resistance, relative to a plain tube ( R f ∗ / R P ∗ ). Significant long-term fouling would not be expected in applications using relatively clean water.

Dynamics of Solitary Waves Through Taper-Thin Elastic Tube with Localized Deformation

In order to elucidate the dynamical behaviour of nonlinear waves in tapered-thin and elastic tubes with localized deformations, we have developed a mathematical model based on equations of inviscid fluid flow in a slowly tapered cone tube. Numerical simulation of the resulting perturbed Korteveg–de Vries equation shows that the amplitude of the velocity wave decreases along the tube as the results of the decrease of the radius and the increase of the rigidity; we also find that the velocity of the pulse velocity wave increases. In the localized deformation area, after some fluctuations, the wave suffers important variations consisting firstly (in the case of constriction) by a decrease and then by an increase. The severity and the length of the variation depend respectively on the amplitude and the gradient scale of the localized deformation. Some biological implications are given.

Experimental quasi-static axial crushing of cone–tube–cone composite system

Abstract An experimental investigation was carried out to study the crashworthiness parameters of cone–tube–cone composite system. The quasi-static crushing behaviour of axially compressed cone–tube–cone composite system has been investigated experimentally. The conical parts of composed system were symmetric. The cone vertex angles used were 10 and 15°. Two arbitrary cone ratios of height-to-base-diameter ( C / D 1 ) have been explored. The tubular part heights were varied between 0 and 50 mm and between 0 and 20 mm for 1.41 and 0.69 of C / D 1 ratios, respectively. Load–displacements curves and deformation histories of typical specimens are presented and discussed. The results showed that structures with ratios (tube-height-to-total-height) vary between 0.06 and 0.11 exhibit a higher crashworthiness performance.