Tube Shape Research Articles

Coniform Gastric Tube for End-to-End Anastomosis During Minimally Invasive McKeown Esophagectomy

For McKeown esophagectomy, gastric tube is widely used for constructing esophagogastrotomy. Traditionally, the gastric fundus is preserved for gastric tube formation in order to provide adequate length of the gastric conduit for neck anastomosis. Nevertheless, gastric stump necrosis, anastomotic leakage, and postoperative gastric tube dilatation are the common postoperative complications for McKeown esophagectomy using traditional gastric tube. Here, we report a novel coniform gastric tube shaping technique to maximally avoid conduit dilatation after the McKeown esophagectomy without nasogastric tube placement, while simultaneously maintaining a tension-free and well-perfused anastomosis.

Explicit error modeling of dynamic thermal errors of heavy machine tool frames caused by ambient temperature fluctuations

The frames of heavy machine tools generate considerable dynamic and position-dependent thermal errors due to their large scale and irregular temperature distribution caused by ambient temperature fluctuations. They are difficult to predict by conventional experimental data-based thermal error modeling methods. In this paper, a typical gantry frame of a heavy gantry type machine tool is taken as a vehicle to present a thermal error modeling methodology. The frame was firstly divided into several parts (elements). Then, an element simplification method was put forward to approximate it by simplified square tube shapes that retain most of the information from the original element. Based on this simplification, the temperature distribution and the equivalent load of the element were explicitly derived at selected key points on the frame. The static thermal error of the frame was obtained by the matrix displacement method, where a C1 continuity stiffness matrix, including the shear deformation, was used to improve calculation accuracy. According to the formulated calculation method of the static thermal error and of the temperature impact convolution, the dynamic thermal error was derived utilizing the historical temperature sequence at the key points. Finally, the proposed thermal error model was verified by comparing it with FEM results in the static-state and by experimental results in the dynamic-state. The proposed method allows the formulation of an explicit dynamic thermal error model with a simple expression, which can be easily embedded in the PLC of a machine tool for compensation purposes. The method has the potential to be used for structural thermal error compensation in a wide range of heavy machine tools.

Effects of physicochemical properties of TiO2 nanomaterials for pulmonary inflammation, acute phase response and alveolar proteinosis in intratracheally exposed mice

Nanomaterial (NM) characteristics may affect the pulmonary toxicity and inflammatory response, including specific surface area, size, shape, crystal phase or other surface characteristics. Grouping of TiO2 in hazard assessment might be challenging because of variation in physicochemical properties. We exposed C57BL/6 J mice to a single dose of four anatase TiO2 NMs with various sizes and shapes by intratracheal instillation and assessed the pulmonary toxicity 1, 3, 28, 90 or 180 days post-exposure. The quartz DQ12 was included as benchmark particle. Pulmonary responses were evaluated by histopathology, electron microscopy, bronchoalveolar lavage (BAL) fluid cell composition and acute phase response. Genotoxicity was evaluated by DNA strand break levels in BAL cells, lung and liver in the comet assay. Multiple regression analyses were applied to identify specific TiO2 NMs properties important for the pulmonary inflammation and acute phase response. The TiO2 NMs induced similar inflammatory responses when surface area was used as dose metrics, although inflammatory and acute phase response was greatest and more persistent for the TiO2 tube. Similar histopathological changes were observed for the TiO2 tube and DQ12 including pulmonary alveolar proteinosis indicating profound effects related to the tube shape. Comparison with previously published data on rutile TiO2 NMs indicated that rutile TiO2 NMs were more inflammogenic in terms of neutrophil influx than anatase TiO2 NMs when normalized to total deposited surface area. Overall, the results suggest that specific surface area, crystal phase and shape of TiO2 NMs are important predictors for the observed pulmonary effects of TiO2 NMs.

Numerical investigation on the behaviour of concrete in-filled cold-formed duplex stainless steel square tubular column

PurposeConcrete in-filled stainless steel square tubular column combines both the benefits of concrete and steel material, providing enhanced ductility and high compressive strength to the vertical structural members. Other advantages include high stiffness, better resistance to corrosion, increased pace of construction, enhanced bearing capacity, etc. The purpose of this paper is to understand the various behavioural aspects of concrete in-filled cold-formed duplex stainless steel (CI-CFDSS) square tubular column under axial compressive loads and to assess its structural performance.Design/methodology/approachIn the current paper, the performance of CI-CFDSS square tubular column is numerically investigated under uniform static loading using finite element technique. The numerical study was based on an experimental investigation, which was carried out earlier, in order to study the effects of concrete strength and shape of stainless steel tube on the strength and behaviour of CI-CFDSS square tubular column. The experimental CI-CFDSS square tubular column has a length equal to 450 mm, breadth of 150 mm, width of 150 mm, thickness of 6 mm and a constant ratio of length to overall depth equal to 3. Numerical modelling of the experimental specimen was carried out using ABAQUS software by providing appropriate material properties. Non-linear finite element analysis was performed and the load vs axial deflection curve of the numerical CI-CFDSS square tubular column obtained was validated with the results of the experiment. In order to understand the behaviour of CI-CFDSS square tubular column under axial compressive loads, a parametric study was performed by varying the grade of concrete, type of stainless steel, thickness of stainless steel tube and shape of cross section. From the results, the performance of CI-CFDSS square tubular column was comparatively studied.FindingsWhen the grade of concrete was increased the deformation capacity of the CI-CFDSS square tubular column reduced but showed better load carrying capacity. The steel tube made of duplex stainless steel exhibited enhanced performance in terms of load carrying capacity and axial deformation than the other forms, i.e. austenitic and ferritic stainless steel. The most suitable cross section for the CI-CFDSS square tubular column with respect to its performance is rectangular cross section and variation of the steel tube thickness led to the change of overall dimensions of the N-CI-CFDSS-SHS1C40 square tubular column showing marginal difference in performance.Originality/valueThe research work presented in this manuscript is authentic and could contribute to the understanding of the behavioural aspects of CI-CFDSS square tubular column under axial compressive loads.

The effect of copper-based catalytic converter with circular tube shape on exhaust emission of Yamaha Vixion 1PA

Indonesia is one of the countries with the third highest air pollution in the world. The biggest contributor air pollution is produced by motorbikes by 60-70%. One the causes of increased exhaust emission is widespread use absorptive exhaust that designed without catalytic converter. The aims of this research is to determine the effect of copper-based catalytic converter with circular tube shape on exhaust emission of Yamaha Vixion 1PA. This study used an experimental research design. The objective of this research is copper catalyst with circular tube shape model. The research instrument used the gas analyzer HG-510 as a test tool for data collection of exhaust emission. Data analysis using inferential statistical techniques paired sample T test through the SPSS 24 statistical analysis application. The results showed that the addition of copper catalytic converter with a circular tube shape model can reduce CO exhaust emission by 16.67%, whereas for exhaust emission HC can be reduced by 32.54%.

Numerical simulation study on the flow and heat transfer characteristics of sub-cooled boiling in vertical round and flattened tubes

Sub-cooled boiling is crucial in dominating the operation performance in several engineering processes. In spite of the experimental investigations conducted in the previous reports, the mechanism of how tube shape affects the heat transfer is still in vagueness. Here, a simulation study on the sub-cooled water flow boiling in tubes of various shapes is performed by adopting the RPI (Rensselaer Polytechnic Institute) model to elucidate the structural effect on the hydraulic and thermal performance, including the average vapor volume fraction and pressure drop. The results demonstrate that for tubes with aspect ratio (AR) ranging from 0 to 5 the heat transfer performance varies greatly, among which the testing tube with AR = 3 exhibits the supreme. The heat transfer coefficient and pressure drop show an around 20% and 7% enhancement, respectively, when the tube AR increases from 0 to 3. Our results show: for these geometric and physical models, when aspect ratio (AR = 0, 1, 3 and 5) of flattened tube is equal to 3 which has the best heat transfer performance and then tends to be stable. For other factors, the heat transfer coefficient enhances by increasing heat flux (395.8 kW/m2, 475 kW/m2 and 570.0 kW/m2), mass flux (900, 990 and 1080 kg/(m2·s)). Heat transfer coefficient increases about 20%, pressure drop augments about 7% when the flattened tube’s AR increases from 0 to 3.

OC24.04: Study on correlation between tubal patency and uterine pressure under three‐dimensional hysterosalpingo‐contrast‐sonography

This study focus on the relationship between patency and morphology of the fallopian tube and the dynamic changes of intrauterine pressure to explore the semi-quantitative grading of tubal patency. 125 fallopian tubes of 67 patients, including 2 single-horned uterus and 7 unilateral fallopian tubes because of a unilateral salpingectomy for an ectopic pregnancy were studied, exclude at least one side of patients with tubal obstruction. According to the patency classification standard of fallopian tubes, they were divided into patency group (the fallopian tube has a natural shape, uniform and aspillage from the fimbrial end of the tubes, 103 tubes) partial patency (the fallopian tube is twisted, the ampulla is bulging, the thickness is uneven and the a spillage from the fimbrial end is slow, 22 tubes). There was a significant difference between the development pressure of the fallopian tube and the peak pressure of the uterine cavity in the patency group and the partial patency group (P < 0.01). According to the ROC curve, the best cutoff value of partial patency fallopian tube development pressure is 18Kpa, the sensitivity is 71.43%, and the specificity is 81.73%. In the partial tubal, the tubal development pressure is low but the shape is distorted and reflexed, this is adhesion around the fallopian tube because of chronic pelvic inflammatory disease and other diseases, the fallopian tube is actually patency. While subtracting the case which the development pressure is lower than 18Kpa, the pressure value of the best cutoff value for the patency tubal is 18Kpa (the sensitivity is 93.75% and the specificity is 82.57%). 3D HyCoSy combined with uterine pressure can more clearly show the patency of the fallopian tube, which can further improve the diagnostic accuracy. Pressure quantification combined with the shape of the fallopian tube contribute to the specific grading of tubal patency.

Numerical and Experimental Study on Deficient Short Steel Tubes Strengthened with CFRP Under Compression

In view of development and repair costs, support of structures is imperative. Several factors, for example, design and calculation errors, absence of appropriate installation, change of structures application, exhaustion, seismic tremor, fire and natural conditions diminish their strength. In such cases, structures have need of rehabilitation and restoration to achieve their original performance. One of the most up to date materials for retrofitting is carbon fiber reinforced polymer (CFRP) that can provide an amount of restriction to postpone buckling of thin steel walls. This paper provides a numerical and experimental investigation on CFRP strengthened short steel tubes with initial horizontal and vertical deficiency under compression. Ten square and circular specimens were tested to study effects of the following parameters: (1) position of deficiency, horizontal or vertical; (2) tube shape, square or circular; (3) CFRP strengthening. In the experiments, axial static loading was gradually applied and for the numerical study three-dimensional (3D) static nonlinear analysis method using ABAQUS software was performed. The results show that deficiency reduces load-bearing capacity of steel columns and the impact of horizontal deficiency is higher than the impact of vertical deficiency, in both square and circular tubes. Use of CFRP materials for strengthening of short steel columns with initial deficiency indicates that fibers play a considerable role on increasing load bearing capacity, reducing stress at the damage location, preventing deformation caused by deficiency and delaying local buckling. Both numerical and experimental outcomes are in good agreement, which underlines the accuracy of the models adopted.

Experimental and theory investigations on falling film flow characteristics and heat extraction performance of spray heat exchanger for sewage heat pump system

The flow characteristics of sewage directly affect the technical and economic performance of sewage-source heat pump systems in heat extraction from sewage. To prove there is significant improvement in heat extraction from sewage with the spray heat exchanger for sewage heat pump system (SHPS): (1) The flow states of the falling film on and between the multiple horizontal tubes were investigated experimentally. The correlations of Reynolds number (range from 100 to 600) and the tube distances to the flow were derived; (2) A model was developed for the falling film flow state analysis of the horizontal elliptical tube of the spray heat exchanger using the ellipse plotting method, which was constructed using approximately three circular arcs. The laser-induced fluorescence technology was used to measure the horizontal tube falling film thickness of water. This experiment focused on the film thickness distribution characteristics of Al-brass tubes with outside diameters of 19 mm and 25.4 mm in column flow with the tube spacing ranging from 20 mm to 40 mm and the Reynolds number (Re) ranging from 184 to 368. The images of the gas-liquid interface were captured with a digital camera. The image processing technology was used to quantitatively describe the liquid film thickness around the horizontal tube. The comparisons between the falling film thickness calculation results and experimental data were in good agreement for the variation of the angle of the elliptical surface and the specific liquid rate. Furthermore, a novel correlation was developed to describe the Nusselt number which was subjected to the examined tube shapes; (3) The heat extraction performance of SHPS with spray heat exchanger was experimentally investigated. The temperature of the sewage ranged from 10 to 30℃. The heat supply, input power, COP, and output water temperature of the condenser of the SHPS were discussed. The results of the proposed calculation method were in conformity with the experimental data and gave good predictions with maximum deviation being lower than 8.6%. Thus, the proposed method is helpful in improving the design and the performance of the SHPS.

Wastewater treatment by dielectric barrier discharge plasma

This paper presents the influence of atmospheric non-thermal plasma on household wastewater by using dielectric barrier discharge (DBD) plasma generator. The model was designed in a vertical coaxial tube shape. The high voltage was supplied from high frequency AC power supply to the model for plasma generation at 0 (control group), 10, and 15 kV. Wastewater was released from the top of glass tube passing through DBD corona discharges that was generated between the needle tips and the glass tube, flowed down to the storage tank, and pumped to the top of the model again. The treatment process was operated for 30 minutes with the flow rate of water at 2 min/L. From the experimental results, it shows that all plasma treatment conditions could improve the wastewater quality. The best results were found at 15 kV plasma treated wastewater; the alkalinity, dissolved oxygen (DO), and conductivity were increased from the control group for 10.48%, 10.09%, and 17.79%, respectively. In addition, biochemical oxygen demands (BOD), and chemical oxygen demand (COD) were decreased from the control group for 7.5 times and 37.5%, respectively. An offensive odor of wastewater could be also improved.

Experimental study of falling film flow characteristics outside shaped tubes related to a spiral‐wound heat exchanger

AbstractIn this paper, the falling film flow and the effects of the marine inclination on the shell‐side flow pattern outside the sinusoidal corrugated tube and the square‐corrugated tube related to a spiral‐wound heat exchanger are experimentally studied using n‐pentane as the testing fluid. The flow field phenomenon and the film thickness are investigated with the utilization of high‐speed camera technology. The results show that the critical Re of the flow regime transition of the falling film outside the square‐corrugated and sinusoidal corrugated tubes is quite different from the critical Re of the flow regime transition of the falling film outside the horizontal circular tube. The tube shape has a certain impact on the falling film flow characteristics. Moreover, under the inclination conditions, the liquid column and liquid film will move toward the inclined side. The resistance ability of the inclination of the square‐corrugated tube is better than the resistance ability of the sinusoidal corrugated tube due to the dragging effect.

Experimental study on dominant vortex structures in near-wall region of turbulent boundary layer based on tomographic particle image velocimetry

Vortex structures are very popular research objects in turbulent boundary layers (TBLs) because of their prime importance in turbulence modelling. This work performs a tomographic particle image velocimetry measurement on the near-wall region ($y&lt;0.1\unicode[STIX]{x1D6FF}$) of TBLs at three Reynolds numbers $Re_{\unicode[STIX]{x1D70F}}=1238$, 2286 and 3081. The main attention is paid to the wall-normal evolution of the vortex geometries and topologies. The vortex is identified with swirl strength ($\unicode[STIX]{x1D706}_{ci}$), and its orientation is recognized by using the real eigenvector of the velocity gradient tensor. The vortex inclination angles in the streamwise–wall-normal plane and in the streamwise–spanwise plane as functions of wall-normal positions are investigated, which provide useful information to speculate on the three-dimensional shape of the vortex tubes in a TBL. The difference between the orientations of vorticity and swirl is discussed and their inherent relationship is revealed based on the governing equation of vorticity. Linear stochastic estimation (LSE) is further deployed to directly extract three-dimensional vortex models. The LSE velocity fields for ejection events happening at different wall-normal positions shed light on the evolution of the topologies for the vortices dominating ejection events. LSE based on a centred prograde spanwise vortex provides a typical packet model, which indicates that the population density of the packets in a TBL is large enough to leave footprints in conditionally averaged flow fields. This work should help to settle the severe debate on the existence of packet structures and also lays some foundation for the TBL model theory.

Heat and mass transfer performance of wet air flowing around circular and elliptic tube in plate fin heat exchangers for air cooling

Fin and tube heat exchangers are widely used in air conditioning. In this study the effect of tube shape on air-side heat and mass performance was experimentally and numerically investigated under typical operating condition, varying both dry bulb temperature and air flow velocity. The experimental results showed that the dry-bulb temperature has little impact on sensible heat transfer rate, whereas the mass transfer rate increased with the increase of dry-bulb temperature. Compared with circular tube, the heat transfer coefficient of elliptic tube is about 66% higher and the dehumidifying coefficient is around 21% higher. However, the difference of the dehumidifying coefficient between two tube shapes shrinks towards equality when the dry bulb temperature reaches to 28 °C. To further discuss the heat transfer mechanism of circular and elliptic tube heat exchangers, three-dimensional numerical simulations were conducted based on the experiments. The results showed that the heat and mass transfer performance was closely related to the tube shape. When wet air flowed around elliptic tube, the streamline shape served to make the flow and temperature field uniform. The flow boundary layer as well as temperature boundary layer was thinned, especially on the upstream and downstream of tubes, so the influence of wake was reduced and the water vapor was efficiently removed. This results in improvement of the heat and mass transfer performance in the wake region of each tube. For the same heat duty, the plate fin heat exchanger with elliptic tube is more compact than that with circular tube.

Study of collapsed deformation and energy absorption of polymeric origami-based tubes with viscoelasticity

The study aims to investigate the effects of origami morphology and interval distribution on the mechanical behavior of origami-based and conventional tubes. Quasi-static axial crushing experiments have been conducted on six geometrical types of polymeric tubes with different morphology (including arrangement and patterns), uniform and non-uniform interval. The polymeric tubes having viscoelasticity are fabricated through a polymer blow molding approach, in which, the approach can ensure the integrated formation of these tubes and avoid the structural asymmetry caused by the machining process. The experimental results show that it is convenient to observe the collapsed position, plastic hinges, and collapsed modes from the crushed and incompletely recovered shapes of the polymeric tubes after 24-h unloading. The initial elastic stiffness and initial peak force of the origami-based tubes reduce dramatically as compared with those of the conventional tubes under the axial crushing. In addition, the origami morphology and interval distribution can cause the initial collapse and have a large effect on the final collapsed mode of the tube, while the effect of wall thickness on the collapsed mode can be negligible. Therefore, the origami morphology or non-uniform interval distribution of the origami-based tubes can be used as a geometrical defect to change the collapsed mode and as a trigger to orient the initial collapse in a certain position of the tube in engineering design.

Parametric design exploration of fin-and-oval tube compact heat exchangers performance with a new type of corrugated fin patterns

The key incentive of current research is to perform numerically a parametric investigation of the thermal-hydraulic performance in a fin-and-tube compact heat exchanger (FTCHE) presenting innovative design of fin profiles and oval form of tubes. Three different corrugated profiles of fin design consist of ONCF (corrugated fin with one fluted domain), TWCF (corrugated fin with two fluted domains), and THCF (corrugated fin with three fluted domains) shapes are investigated by a parametric design exploration technique combined with response surface methodology (RSM). The impacts of the nine geometrical factors counting fin pitch (Fp), longitudinal tube spacing (SL), transverse tube spacing (ST), fin thickness (δf), fin width (Fw), fluted height (hf), wing length of corrugated fin (Wout), wing angle (α), and fluted angle (β) on improving the heat transfer performance of a corrugated-fin-and-tube compact heat exchangers with a four-row inline oval tube bank are studied for the range of Reynolds number between 500 and 5000. Fluid flow and heat transfer are simulated using Realizable k–ε turbulence model with steady and incompressible fluid flow. The numerical outcomes show that the fins with corrugated profiles can significantly increase heat transfer enhancement through modification of the situation with respect to the shape of oval tube, fluted number and different parameters of fluted areas. The outcomes of study indicated that the η-factor (Thermal-hydraulic performance criteria) of the FTCHE with one-corrugated fin is superior than that of conventional and other case studies. The η-factor in FTCHEs with THCF, TWCF, and ONCF designs displayed 20.9%, 13.3%, 36.0% augmentation compared with its conventional smooth fin and oval tubes counterpart, respectively. Furthermore, FTCHE with ONCF design has the best performance between other fin designs. The investigation indicated that the corrugated fins can significantly advance the heat transfer and performance of the FTCHEs.

Dynamic plastic behaviour of strain rate sensitive tubes under axial impact

In this paper, the axisymmetric buckling of circular strain rate sensitive tubes subjected to axial impact is investigated theoretically and experimentally. The nonlinear governing equations are first derived in an incremental form. Then, the finite difference method is employed to solve the obtained equations implicitly for the case when a stationary tube is impacted by a striking mass. Experimental tests are performed by using a gas gun. The effect of linear and multi-linear approximation for strain hardening and strain rate on the shortening, buckling shape and axial force of steel tubes are investigated in which the strain rate is considered as a function of time. By applying the strain rate effect and using the multi-linear approximation for strain hardening, we showed there is a significant association between theoretical and experimental results of steel tubes. Also, using the nonlinear dynamic equations and newly developed inexact finite similitude theory it is revealed that the response characteristics of full-scale strain rate sensitive tubes can be predicted using small-scale strain rate insensitive tubes.

Optimization of Kaplan Hydroturbine at Very Low Head With Rim-Driven Generator

The objective of the paper is to study the design and optimization of Kaplan hydroturbines for a very low head (less than 3 m), with a particular emphasis on the use of rim-drive electrical generators. The work is based on an experimental setup and computational fluid dynamics (CFD) analysis of various design parameters for maximum output power and efficiency. Two designs are presented in this paper. One is a 90-cm (35-in.) diameter vertical-oriented Kaplan hydroturbine system as an intended product capable of generating over 50 kW. The other is a smaller, 7.6-cm (3-in.) diameter horizontal-oriented system for prototyping and laboratory verification. Both are analyzed through CFD based on large eddy simulation (LES) of transient turbulence. Specific design for the runner and the stator, intake tube shape, as well as guide vanes upstream of the turbine was studied to get the most from the available head. The intent is to use 3D-printing manufacturing techniques, which may offer original design opportunities as well as the possibility of turbine and water conduit design customization as a function of the head and flow available from a specific site. Based on the CFD analysis, the 7.6-cm diameter system achieved the highest power output and the maximum efficiency at the rotational speed range of 1500–2000 rpm, while for the experimental testing, the optimum rotational speed range was 1000–1500 rpm. Because of the mismatch between CFD and experimental results, the CFD results were correlated due to the presence of air and friction; moreover, error and uncertainty analysis were presented for both methods. For the 90-cm case, the optimum performance was found at a rotational speed around 350 rpm according to the CFD results. Finally, investigating the shape of the intake tube of the hydroturbine setup can significantly increase the power output and the efficiency of the system.

QuBiT: a quantitative tool for analyzing epithelial tubes reveals unexpected patterns of organization in the Drosophila trachea.

Biological tubes are essential for animal survival, and their functions are dependent on tube shape. Analyzing the contributions of cell shape and organization to the morphogenesis of small tubes has been hampered by the limitations of existing programs in quantifying cell geometry on highly curved tubular surfaces and calculating tube-specific parameters. We therefore developed QuBiT (Quantitative Tool for Biological Tubes) and used it to analyze morphogenesis of the embryonic Drosophila trachea (airway). In the main tube, we find previously unknown anterior-to-posterior (A-P) gradients of cell apical orientation and aspect ratio, and periodicity in the organization of apical cell surfaces. Inferred cell intercalation during development dampens an A-P gradient of the number of cells per cross-section of the tube, but does not change the patterns of cell connectivity. Computationally 'unrolling' the apical surface of wild-type trachea and the hindgut reveals previously unrecognized spatial patterns of the apical marker Uninflatable and a non-redundant role for the Na+/K+ ATPase in apical marker organization. These unexpected findings demonstrate the importance of a computational tool for analyzing small diameter biological tubes.

Performance and Evaluation of Drip Irrigation System, and Its Future Advantages

The drip irrigation system is a kind of micro-irrigation system that has the potential to salvage the water and other nutrients by entrance water to drip gradually to the main roots of plants and other plant parts, which is from on the soil surface or buried inside the soil surface. The main aim of drip irrigation is to place water directly into the main root zone and decrease the water vapor. The system Drip irrigation spreads water through a schematic shape of different tubes, emitters, pipes, and valves. Its depending on the designed how well it make, maintained, installed, and operated it is, a system drip irrigation can be more useful than other various types of drip irrigation systems, like as sprinkler irrigation or surface irrigation. The system drip irrigation is firstly introduced mainly to save water and step-up the water use efficiency in agriculture field. More ever, it also presents various other social and economic benefits to the society. In drip irrigation system water is utalized micro jet or by drop by drop, on the surface of soil or under the soil, at a lower rate than the infiltration of the soil. In our this research, deeply research works heed water management for system drip irrigation and its upcoming advantages has been discussed and reviewed so that a precise perception may be existence for the farmers and for futures. Keywords: Drip irrigation, dipper line, water, Fertigation system. DOI: 10.7176/JBAH/9-9-04 Publication date:May 31st 2019

Cyclic behavior of steel tube-reinforced high-strength concrete composite columns with high-strength steel bars

To study the cyclic behavior of steel tube-reinforced, high-strength concrete columns with high-strength steel bars, a cyclic loading test of six full-sized square columns was carried out, including one traditional reinforced concrete (RC) column and five steel tube-reinforced concrete (STRC) composite columns. The cross-sectional shape of the inner steel tube, the strength matching of the outer concrete and the core concrete, and the presence of steel fiber in outer concrete were the major parameters of the test. The research shows that steel fiber-reinforced high-strength STRC composite columns had better seismic behavior compared to RC columns. The strength matching method, where the C90 core concrete was combined with the C70 outer concrete, resulted in a better composite effect in comparison to the method of using C80 concrete in both core concrete and outer concrete. Moreover, the addition of steel fibers in outer concrete effectively reduced the damage degree and improved the ductility, resilient capacity, and energy dissipation capacity of the specimens. Finally, based on the test research and theoretical analysis, a calculation model for predicting the maximum load-carrying capacity was proposed. The model was then verified by comparing its predictions with test results.