Rubber Hose Research Articles

Performance of a ring-shaped emitter for subsurface irrigation in bell pepper (Capsicum annum L.) cultivation

A low-cost subsurface irrigation system with ring-shaped emitters has been applied and considered as a way to improve water irrigation efficiency in a region where farming is performed on a small scale, especially in rural areas of Indonesia. To build a ring-shaped emitter, a rubber water hose was bent into a ring shape with a diameter of about 20 cm, and a given number of 5-mm holes were drilled into it. The ring-shaped hose was then covered fully with a permeable textile so that irrigation water can be distributed in all directions around the emitter. Our previous study showed that, depending upon the soil type, the number of holes can be reduced from 5, which was originally used, to 2. We also proposed an emitter that was covered partially by the permeable textile to simplify maintenance. The study showed that the partially covered emitters performed similarly to a fully covered one. This study aims to investigate the performance of the newly designed emitter, with two drilled holes, in bell pepper cultivation. Cultivation experiments were carried out in a greenhouse during the summer of 2017. In the experiment, a bell pepper nursery was planted in a plant pot in which the ring-shaped emitter was buried at a depth of 15 cm. In addition to the newly designed emitter with two holes that was partially covered by the permeable textile, the original fully covered emitter with five holes was used in this experiment for comparison. Water was then supplied from a Mariotte tank connected to the buried emitter by maintaining a water pressure head of 1 cm at the inlet of the emitter for 2 h during cultivation. Plant heights, biomasses and yields were measured to determine water-use efficiency. As a result, while the irrigation was more efficient with the modified emitter in terms of enhancing root zone water distribution and water use efficiently (96.0% with the new emitter compared to 75.2% with the original emitter), plant growths were not significantly different. This study suggested that subsurface water application using a modified ring-shaped emitter will be able to maintain soil water content (SWC) in the root zone properly without causing water stress for plants.

Seepage mechanism technical practice of hydraulic fracturing of coal seam and auxiliary image simulation technology

A new method of fracturing hydraulic fracturing is proposed for the characteristics of poor coal permeability and soft coal in coal mine area in China. This method can make the hydraulic pressure concentrated on the coal at one point, and the water pressure is reduced, Effective water pressure increases, the smaller the flow that can get a better fracture effect. Through the numerical simulation, the law of fracture distribution and permeability evolution during segmental hydraulic fracturing is analyzed. Complete sets of anti-reflection equipment for segmented hydraulic fracturing have been developed, which is mainly composed of mobile high-pressure pump station, high-pressure rubber hose, water injector, putters and corresponding connecting parts. It solves the problem of tightness of hydraulic fracturing device, and breaks through the problem of miniaturization of high pressure pumping station, so that the high pressure pumping station can achieve larger working pressure at smaller flow rate. The whole process is simulated and validated by assistant image simulation technology, and applied to Pansidong Coal Mine of Huainan Mining Group. The industrial test of hydraulic directional fracturing of Pan coal mine in Huainan mining group shows that the loose influence range of coal can reach 10 m, and the pressure of underground movable high pressure hydraulic pumping station reaches 25 MPa, and the flow rate is 180 L/min. Compared with non fracturing drilling, drilling, the average gas concentration after fracturing, the average daily average flow rate of mixed gas drainage quantity is improved significantly, the application effect is good, and the equipment is simple, easy to use, can be repeatedly used, and has better economic benefit and application prospect.

Experimental and numerical evaluation of a ring-shaped emitter for subsurface irrigation

A low-cost subsurface irrigation system can generate benefits for small-scale farmers who have scarce water resources. A ring-shaped emitter made from a standard rubber hose has been developed and introduced for subsurface irrigation in Indonesia. It is a low-cost irrigation technology based on indigenous materials and skills. To build a ring-shaped emitter of the original design, a rubber hose is bent into a ring shape with a diameter of about 20 cm, and then five 5-mm holes are drilled into it at even intervals. Next, the entire ring-shaped hose is covered with a permeable textile so that water can infiltrate in all directions around the buried emitter. Water is applied from a water tank connected to the emitter by adjusting the pressure head imposed at the inlet of the emitter. Although it has been successfully used in practice, the performance of the ring-shaped emitter has not been evaluated in detail. Additionally, because the ring-shaped hose is fully covered with the textile, it may be difficult to detect any malfunctions or repair it. To promote the ring-shaped emitter for subsurface irrigation among small-scale farmers in arid or semi-arid regions, it is important to design an emitter that is easy to maintain. This study proposes a reduction in the number of holes and a change of covering method. Because the number of experiments that can be carried out to evaluate the performance of alternative ring-shaped emitters is usually limited, numerical simulations can be performed in addition to experiments. The main objectives of this study thus were 1) to experimentally investigate the water movement around a buried ring-shaped emitter and 2) to numerically evaluate the effect of modifying the design of the ring-shaped emitter on soil water dynamics around the emitter. Numerical simulations were carried out using HYDRUS, one of the most complete packages for simulating variably-saturated water flow in two- or three-dimensional domains. HYDRUS simulations in a fully three-dimensional domain were performed using the soil hydraulic parameters that were optimized against experimental data collected during experiments with the original ring-shaped emitter. Simulation results confirmed that reducing the number of holes does not significantly affect the water availability in silt for model plants, such as tomato and strawberry, and that covering the entire emitter is not necessary. Partially covering the emitter allows one to maintain the emitter much more easily compared to the original fully-covered emitter.

The War Diet Squad

World War I ended 100 years ago this year. As we remember this historic event, the poem below reminds us of some of the sacrifices that people on the home front made to further our understanding of the long-term effects of a restricted diet that would be one result of the war in Europe. These experiments performed by Francis Gano Benedict and his colleagues ((1)) as well as this poem about them give us a moment to be thankful for the volunteers who make metabolic research like this, and like the Minnesota Experiment 30 years later ((2)), possible; for the investigators who conduct these important studies; and for the people who have the wisdom to fund them. The poem below was found when examining my collection of books dealing with the work of Atwater and Benedict. Lying loose inside the front cover of one book was the poem that I transcribed below. It was on a piece of carbon paper folded in thirds and a bit browned after 100 years in this volume. After transcription, the poem was returned to the book from which it came. Elected to the diet squad They have us on the mat, For with unholy ecstasy They sacrifice our fat. Though volunteers we surely were We met our surprise With every kind of instrument That science could devise. No beauty sleep for us again We break our morning rest With rubber hose beneath our nose And chains across our chest Our pulse is taken as we sat Our weight recorded every morn, Our photograph taken twice In all the raiment we were born. The “Foxey” man devised our food While Emmes the bran alone Dr. Roth is over both And is our chaperon. Now Benedict comes in from town To keep us all in trim, The man has never yet been born That puts one over him. With differential calculus They estimate our pie, So when the light falls on it right We see with one eye. Pedometers now register How many miles we go, Prof. Miles and Cupid Hills Determine what we know. With mechanisms intricate They test our ears and eyes, One can’t make good on all of them No matter how he tries. Prof. Johnson has the last device A most ingenious plan. A stationary bicycle To help break down a man. Doc Goodall has a nifty touch With stunning perspicacity Determines where each organ lays And its exact capacity. He “mauls”, massages, and tickles us And marks how we grow thinner Can even feel and then reveal The bran we had for dinner. We now expend our odd week ends In a most distinguished town For churls and girls and brains and beans Has won a large renown. Hermetically sealed within A very real sarcophagus Without a peep, we sweetly sleep With angels watching over us. Emaciated, hollow, thin, We simply are a sight You never saw a billy-goat With such an appetite Miss Hendry is an antidote A joy, a glad surprise The one bright ray across the gloom A feast for all our eyes. All this fuss and this expense Is done to find the limit To which they can reduce our skin And keep our bones within it. R.W. Peckham October 27, 1917

Demonstrative effect of adapted hydraulic ram as a drawbar dynamometer in tractor operations

This study is focused on adapting a pair-loader hydraulic ram for use as a drawbar hydraulic dynamometer for field tests and presenting simulative views in 3D. The ram pressure unit consists of a cylinder, piston and push rod with the hydraulic cylinder having a capacity of 26.7kN draft was used. The maximum length of ram is 540mm, diameter of piston is 80mm, and diameter of cylinder is 120mm. A hand held pressure gauge was used with maximum range capacity of 11N/mm2. The transmission line was made of a high pressure oil rubber hose, 2.75m long, and hydraulic adaptors were used to connect the oil tube to the cylinder and the pressure measuring gauge. Hydraulic dynamometers using calibrated pressure gauge indicator was adapted to measure heavy draft loads. It can be used to determine the draft, drawbar pull and travel reduction (slip) of a tractor with implement in operation and when not in operation. A field test carried out showed that at any given drawbar pull, the slippage increased with increase in draft (drawbar pull).Keywords: Hydraulic dynamometer, drawbar power, tillage operation, field demonstrative tests

Shallow hot-water ice drill: Estimation of drilling parameters and testing

Shallow hot-water systems are well-known ice-drilling devices used to create holes for temperature measurements and monitoring of glacier dynamics, basal sliding, and englacial water-pressure. A shallow hot-water ice drill system designed at Jilin University is based on a commercial high-pressure washer, Kärcher HDS 6/14C, that can deliver water at a temperature in the range of 80–155° C, a flow of 4–10 L/min and a pressure as high as 14 MPa. The system also includes a mast with a sheave on the top and a reel with a 100-m long rubber hose; a 2-m long, 60-mm diameter drill stem; a control and measuring system; sleds; a submersible pump; a return hose; a water tank with an affiliate heating unit; and a small 2-kW generator. Theoretical estimations were performed to predict the rate of penetration and mean diameter of the melted borehole. Experiments with a shallow hot-water drill were carried out in an ice drill testing facility to determine the relationship between the rate of penetration/borehole diameter and the diameter and type of nozzle, hot water temperature, and flowrate. Under a hot water flowrate of 10 L/min with a temperature of 60° C, the 1.8-mm and 2-mm nozzles created 98–114-mm diameter boreholes at a penetration rate of 34–37 m/h, while a 2.5-mm nozzle produced a 146–156-mm borehole at rate of 26 m/h. The deviation between the experimental data and theoretical estimations did not exceed 7%.

Investigation on structural behavior of ring-stiffened composite offshore rubber hose under internal pressure

Ring-stiffened composite offshore rubber hose of single carcass is commonly used for offshore oil transfer. Common hose dimensions are length of 10.7 m and nominal diameter of 500 mm. The nominal burst pressure is 7.5 MPa, equal to five times rated working pressure of 1.5 MPa. The hose carcass is composite cylindrical tube made of rubber, reinforcing fiber cords and steel spiral stiffener that provides radial stiffness. In hose design, the burst pressure shall be determined to verify its pressure bearing capacity. In this paper, a nonlinear finite element hose model is created with commercial software ABAQUS and validated to predict its structural behavior under internal pressure. The large deformations, interactions between components and nonlinear material properties of hyperelastic rubber and fibers are considered. Stresses of stiffener, radial and axial deformation and load in reinforcement plies are obtained. A bulging phenomenon amid two stiffeners is found, which indicates the confine effect of stiffeners. Failure pressure is jointly determined by the strength limit of polymer cords and steel stiffener. The influence of different fibers and rubbers on hose pressure-deformation response are compared. The results demonstrate good accordance with requirement of specification. The finite element model can predict hose failure pressure and provide guidance for reliable hose design in practice.

Development of oil, freeze, high temperature resistant and flame retardant rubber compounds for high performance hydrolic hose

The high performance hydrolic rubber hose should resist to hydrolic oils and can run at temperature interval from –55 0C to 150 0C. In addition to these properties, for some areas such as mining should also be flame retardant. In this study, compound formulations having properties mentioned above were developped, mechanical properties, hydrolic oil and low, high temperature resistance performances were measured. Flame retardant tests were also been performed. Hoses were built using these newely developped compounds and then their burst tests were performed. The best performer compound for low temeperature performance hose was the one prepared with the blends of acrylonitrile butadiene (NBR), stirene-butadiene (SBR) and cis-butadiene (CBR) rubbers along with plasticizer diisononylphthalate (DINP). One of the compounds preapared with the blending of SBR, NBR rubbers, aluminium hydroxide, tricrezyl phoshate (TCP) and zinc borate was the best for the flame retardant hose. The best performer high temeperature resistant compound was preapred using MT N990 carbonblack and plasticizer paraplex G50 with blending of SBR 1502, NBR 2860 and NBR 3360 rubbers.

Особенности применения пеногенерирующих систем со сжатым воздухом для тушения пожаров

Проведен анализ результатов экспериментальных исследований пеногенерирующих систем со сжатым воздухом, приведен пример использования инженерной методики гидравлического расчета рукавных линий при движении компрессионной пены. По результатам теоретических и экспериментальных исследований сформулированы особенности применения пеногенерирующих систем со сжатым воздухом для тушения пожаров, которые учитывают отличие их тактико-технических характеристик от традиционных технологий пенного пожаротушения. Это позволило определить область применения пеногенерирующих систем со сжатым воздухом.

Experimental Analysis on Pre-Stress Friction Loss of Crushed Limestone Sand Concrete Beams

This paper presents an experimental research work that evaluates the pre-stress loss caused by friction in crushed limestone sand (CLS) concrete members with post-tensioning. A total of 26 full-scale pre-stressed concrete beams were constructed and tested for the friction loss experiment. The considered variables mainly included the duct-forming materials, wires of tendons and arrangement of ducts. The tensile forces at both active and passive ends of specimen were recorded by steps, and then the pre-stress friction loss for each case was calculated. The result shows that the proportion of pre-stress friction loss in specimen with multi-wire tendons is in the range of 10–40%, with the trend first increasing before decreasing. The pre-stress friction loss in specimen with curve duct accounts for 10–30%. The pressure on the curved part definitely increases the friction when compared with the straight duct. The pre-stress friction loss in specimen with rubber hose reaches nearly 40%, which is larger than the metal bellow and plastic bellow. The suggested values for each case are proposed for a deviation coefficient κ of 0.0017–0.007 and a friction coefficient μ of 0.108–0.858. This can provide reliable theoretical support for the design and construction.

Viability of Biogas Production from Manure/Biomass in Nigeria Using Fixed Dome Digester

Waste materials produced from agricultural products (such as crop residues, animal manure, and organic waste from Agro - industries dairy production) generally referred to as biomass constitute nuisance to the community as air, water and land pollutant if disposed without treatment. Anaerobic digestion of treating biomass is cheap, easier and economical compare to other methods of waste management like gasification. It produces methane (CH4) gas used for cooking and lighting domestically and industrially while the digestate is a source of fertilizer. A fixed dome digester is built for anaerobic digestion of biomass (cow dung), the plant has digester, mixing tank, gas pipe, inspection tank, gas dome and manhole as major components. Other accessories are rubber hose, gas burner, gas filter and the gas lamp. Materials for the construction of the plant were sourced locally while the accessories were imported from India. Production of biogas through anaerobic digestion improves fertilization efficiency and environmentally sound waste recycling.

Rubber hose surface defect detection system based on machine vision

As an important part of connecting engine, air filter, engine, cooling system and automobile air-conditioning system, automotive hose is widely used in automobile. Therefore, the determination of the surface quality of the hose is particularly important. This research is based on machine vision technology, using HALCON algorithm for the processing of the hose image, and identifying the surface defects of the hose. In order to improve the detection accuracy of visual system, this paper proposes a method to classify the defects to reduce misjudegment. The experimental results show that the method can detect surface defects accurately.

Design of a Fast Measuring System for the Section Size of Automobile Rubber Hose Withhold Parts

The quality of withhold parts determines the service life of high-pressure rubber hose to a great extent. Leakage at withholding is the main form of high pressure hose failure in the several forms. The quickest and most effective method to detect the withholding quality is measuring the section size of the withhold parts. As long as the section size is in line with the provisions, that is, the quality of hose withholding is qualified. In this paper, the mesurement system which is designed improves low efficiency of manual mesurement.

Mechanical property behavior and aging mechanism of carbon-black-filled EPDM rubber reinforced by carbon nano-tubes subjected to electro-chemical and thermal degradation

Ethylene propylene diene monomer (EPDM) rubber filled with Carbon black (CB) has been mainly used for the rubber hose of a cooling radiator in the internal combustion engine system. Moreover, EPDM aging occurs because of electro-chemical and thermal stresses. In this study, Carbon nanotubes (CNTs) with 0, 2 and 4 parts per hundred grams of rubber (phr) were added to EPDM rubber filled with 75 phr CB to form CNT reinforced CB-filled EPDM rubber. Under conditions of 3 temperatures (60, 80 and 100 °C) and constant voltage (DC 12 V), 3 types of EPDM rubber (CB75, C2CB7 and C4CB75) were immersed in coolant water and aged for 7 days (168 h). This study investigated the effects of CB and CNT concentrations in EPDM rubbers on electro-chemical and thermal degradation behaviors and mechanical properties (tensile strength, elongation at the breaking point and IRHD hardness). A conductive mechanism was also proposed for the addition of CNT and CB.

Numerical investigation of swaging process characteristics of fabric braided power steering hose

The power steering hose in automotive power steering system is composed of a rubber hose and two metal fittings. The rubber hose is reinforced by fabric braided layers, while metal fittings are firmly clamped to both ends of rubber hose by the special swaging job. Since the main function of power steering hose is to circulate internal oil without oil leakage, the swaging process of metal fitting should be elaborately designed based on the profound investigation of process characteristics. However, owing to the complex micro structure of braided layers, the swaging process has been investigated either by time- and cost-consuming experiment or by the simple numerical analysis in which the braided layers are simplified as an isotropic solid. To overcome the demerit of experiment and to improve the accuracy of numerical method, an effective numerical analysis method by considering the anisotropy of braided layer is presented in this paper. The braided layers are modeled as an orthotropic solid and their equivalent material properties are derived by utilizing the homogenization method. Through the numerical experiments, the difference between the simple isotropic model and the current orthotropic one is compared, and the swaging process characteristics are investigated to the helix angle.

An Analysis of Structural-Acoustic Coupling Band Gaps in a Fluid-Filled Periodic Pipe**Supported by the National Natural Science Foundation of China under Grant No 11372346.

A periodic pipe system composed of steel pipes and rubber hoses with the same inner radius is designed based on the theory of phononic crystals. Using the transfer matrix method, the band structure of the periodic pipe is calculated considering the structural-acoustic coupling. The results show that longitudinal vibration band gaps and acoustic band gaps can coexist in the fluid-filled periodic pipe. The formation of the band gap mechanism is further analyzed. The band gaps are validated by the sound transmission loss and vibration-frequency response functions calculated using the finite element method. The effect of the damp on the band gap is analyzed by calculating the complex band structure. The periodic pipe system can be used not only in the field of vibration reduction but also for noise elimination.

Design and optimization of CAM connecting rod system in high-speed drives based on dynamic characteristics and mathematical model

To explore the cause of structure vibration, this study aims to propose a kinematic equation and analyze its movement in relation to cam linkage mechanism for a jacketing machine and shearing mechanism. Finite element method is adopted to construct the kinetic model of linkage subsystem of shearing mechanism. This method can solve the inability of the shearing mechanism to accurately complete the shearing actions of the rubber hose during large vibration of the mechanism. Lumped parameter method is adopted to establish the kinetic model of the cam roller subsystem, and Newmark method is used to solve the kinetic equation of the shearing mechanism. The optimal parameters of the linking rod, cam profile, and shaking force and shaking moment of the mechanism at different rotation speeds are analyzed. Results show that rotation speed and cam profile are factors affecting the performance of the mechanism. The shaking force (shaking moment) is the main cause of the vibration of the mechanism on the rack. As such, the shaking force and shaking moment of the mechanism are selected as the objective functions of the optimization model. The node parameters of B-spline curve movement law and cross-section parameters of the linking rod are used as variables for the optimal design of the cam linkage system. Finally, the obtained optimal value is x = [0.33 0.2 0.54 0.62 8.7 3.0 7.8 16.3] T.

Numerical investigation of deformed layout and fatigue life of automotive braking hose to the helix angle of fabric braided layers

The fabric braided rubber hose used in the automotive hydraulic braking system exhibits the anisotropic large deformation while its movable end is moving along the cyclic path during the steering and bump/rebound motions of vehicle. The complicated large deformation may cause not only the interference with other neighboring parts but also the durability problem resulting in the fatal micro cracking. In this regard, the design of high-durable braking hose with the interference-free layout becomes a hot issue in the automotive industry. However, it has been traditionally relied on the cost-/time-consuming trial and error experiments because the computational methodology for the large deformation and fatigue evaluation of the braking hose with the fabric braided layers in complex micro structure pattern has not been fully developed. Furthermore, the hose deformed layout and fatigue life are significantly influenced by the helix angle of braided layers, so that their characteristic investigation becomes an important research subject. As a preliminary step for the optimum design of high-durable and interference-free braking hose, this study investigates the hose deformed layout and the fatigue life cycle with respect to the helix angle of braided layers.

Thermally conductive thin films derived from defect free graphene-natural rubber latex nanocomposite: Preparation and properties

Commercially useful rubber products viz. gloves, condoms, tyres, and rubber hoses used in high temperature environments, etc., require efficient thermal conductivity, which increases the lifetime of these products. Graphene can fetch this property, if it is effectively incorporated into the rubber matrix. The great challenge in preparing graphene-rubber nanocomposites is formulating a scalable method to produce defect free graphene and its homogeneous dispersion into polymer matrices through an aqueous medium. Here, we used a simple method to produce defect free few layer (2–5) graphene, which can be easily dispersed into natural rubber (NR) latex without adversely affecting its colloidal stability. The resulting new composite showed large increase in thermal conductivity (480–980%) along with 40% increase in tensile properties and 60% improvement in electrical conductivity. This study provides a novel and generalized approach for the preparation of graphene based thermally conductive rubber nanocomposites.

Electrochemical degradation tests on a carbon-black-filled ethylene propylene diene monomer rubber under tensile strain

Rubber hoses play an important role as a path for carrying the coolant liquid between the radiator and the automotive engine. However, the rubber hoses are apt to deteriorate because of the formation of a galvanic circuit between the rubber hose, the coolant water and the fitting metal part of the engine. Such electrochemical degradation can damage the inner skin of the hose in contact with the coolant liquid heated by the working engine, which often leads to leakage of the coolant water and thereby to hose failure. An ethylene propylene diene monomer rubber has mostly been utilized as the material for the coolant hoses of automotive engines because of the strong resistance to various environmental stresses. This study conducted experimental simulation tests and evaluation of the electrochemical degradation behaviours of the carbon-black-filled ethylene propylene diene monomer rubber used for the coolant hoses. The tests were performed by considering the actual circumstances together with the combined thermal, tensile strain and electrostatic voltage loadings on the rubber hoses. The behaviour of the change in the electrical resistance of a specimen and, thus, the apparent decrease in the current were analysed quantitatively. An Arrhenius life prediction by using the decrease in the current was reasonably expressed for the accelerated life tests. Many microhole networks were thus formed in the skin part of the specimen by the microbreaks in the carbon-black phase and the scission of the sulphur cross-links. The coolant liquid penetrated significantly into the skin, which resulted in a considerable swelling of the skin. The larger the strain application to the rubber, the lower are the strength and the elongation at the breaking point. An exponential index parameter can represent quantitatively the behaviours of the decreases in the mechanical properties used for accurate life prediction.