Bend Area Research Articles

Using Fluridone Herbicide Systems for Weed Control in Texas Cotton (Gossypium Hirsutum L.)

Studies were conducted during 2015 through 2018 in south-central, Coastal Bend, and Southern High Plains areas of Texas to evaluate fluridone herbicide systems for weed control and cotton response. Fluridone alone at 0.17 to 0.23 kg ai ha-1 followed by postemergence (POST) herbicides controlled Amaranthus Palmeri 82 to 100% season-long while Cucumis melo control ranged from 92 to 100%. Control of Urochloa Texana with fluridone alone ranged from 40 to 96% early-season while late-season control ranged from 37 to 96%. Fluridone plus fomesafen systems controlled A. Palmeri, C. Melo, and U. Texana at least 98% early season; however, late-season control of A. Palmeri was less than 70% while C. Melo control was 91% and U. Texana control was 80%. Adding a POST application of glyphosate to fluridone plus fomesafen improved control to at least 98% for all three weed species. Fluridone plus fluometuron combinations provided similar control to fluridone plus fomesafen. Adding glyphosate (POST) improved A. Palmeri control to at least 82% season-long. Cotton yields reflect the level of weed control with significantly better yields from fluridone systems compared with the weedy check. However, in the one year when the untreated was maintained weed-free, no differences in cotton yield were noted between the weed-free and any herbicide treatment.

Experiment and numerical simulation of sand particle erosion under slug flow condition in a horizontal pipe bend

Sand erosion is a common problem in oil and gas field development. An experimental facility was designed and used to study the sand erosion of pipe bend under slug flow. A detachable test pipe bend was designed to measure the weight loss at 36 discrete locations on the pipe bend before and after each experiment. A Computational Fluid Dynamics (CFD) based erosion prediction method was developed to get a further understanding of the erosion. The relationships among the gas and liquid distribution, the sand movement and the erosion profile were analyzed to explain the erosion mechanism. The most severe erosion area of the pipe bend occurs at the axial angle of the elbow between 67.5° and 90° and at the circumferential angle of the elbow between 45° and 90°. The erosion profiles of the pipe wall are dominated by three particle collision mechanisms, namely, micro-cutting, plowing and impact deformation.

On physical basis of local current overload in vehicle electric mains

Introduction. The data presented in the article indicate that the problem of improving fire safety of vehicles is very topical. The aim of the article is to develop a scientifically based method for studying a copper conductor with signs of local current overload in order to establish the cause of its damage during a fire-technical examination. Materials and methods . The studies were carried out with a JSM-6390LV scanning electron microscope with an add-on device for energy dispersive microanalysis. The fracture surfaces of the copper conductor were analyzed without preliminary sample preparation. Theoretical foundations (theory and calculations). An updated model of ultimate stress-strain state of inelastic pure bending of a copper rod of circular cross section has been developed. The solution has been reduced to simple rating formulas that allow us to evaluate the bearing capacity of flexible single copper conductors. The applicability of the developed mathematical model during the fire-technical examination is shown by a specific example. Results and discussion . Examples of vehicle fires caused by critical bending of the wiring harness are given in the article. Experimental data confirmed that the copper conductor under current overload melts in the critical bend area. The need to clarify the wording of the term “local current overload” is justified. Conclusion. A method for determining the critical bending of a copper conductor at which its melting can occur under electric current has been proposed. The data presented in the article can be used by experts in an expert study of copper conductors from fire sites to establish the mechanism of their damage and, ultimately, the cause of a vehicle fire.

An experimental work on effect of bending down conductor with reinforced concrete

Down conductor is one of the pivotal parts of the Lightning Protection System (LPS) that diverting the lightning current captured by the air termination system to the earth termination system in each protected structure. A straight down conductor, is ideally suited for the best-case scenario regarding reliability and safety protection. One to aesthetical aspects, down conductor is undesirably bent in most current buildings. However, only the primary bare type of a down conductor is undergone such process, and bent at a certain degree which depending on the structure itself. Hence, this study is to investigate the bending degree effect on down conductors, by looking at breakdown voltage around the bent area with the presence of concrete wall and reinforcement bar. This experimental work conducted on a reduced scale of reinforced concrete which tested with high impulse voltage. It was determined that the bending down conductors has a significant effect on the bent (vertex) area with the interaction of concrete wall and reinforcement bar.

Особливості розрахунку елементів з деревини при прямому поперечному згині за деформаційною методикою

Розглянуто особливості методики розрахунку нормальних розрахункових перерізів елементів з цільної та клеєної деревини при поперечному прямому згині за деформаційною моделлю.

Bio-inspired anisotropic polymeric heart valves exhibiting valve-like mechanical and hemodynamic behavior

Native heart valve leaflets with layered fibrous structures show anisotropic characteristics, allowing them to withstand complex mechanical loading for long-term cardiac cycles. Herein, two types of silk fibroin (SF) fiber membranes with anisotropic (ASF) and isotropic (ISF) properties were prepared by electrospinning, and were further combined with poly(ethylene glycol) diacrylate (PEGDA) hydrogels to serve as polymeric heart valve (PHV) substitutes (PEGDA-ASF and PEGDA-ISF). The uniaxial tensile tests showed obvious anisotropy of PEGDA-ASF with elastic moduli of 10.95±1.09 and 3.55± 0.32 MPa, respectively, along the directions parallel and perpendicular to the fiber alignment, while PEGDA-ISF possessed isotropic property with elastic moduli of 4.54± 0.43 MPa. The PHVs from both PEGDA-ASF and PEGDA-ISF presented appropriate hydrodynamic properties from pulse duplicator tests according to the ISO 5840-3 standard. However, finite element analysis (FEA) revealed the anisotropic PEGDA-ASF valve showed a lower maximum principle stress value (2.20 MPa) in commissures during diastole compared with that from the isotropic PEGDA-ISF valve (2.37 MPa). In the fully open state, the bending area of the PEGDA-ASF valve appeared in the belly portion and near the attachment line like native valves, however, which was close to free edges for the PEGDA-ISF valve. The Gauss curvature analysis also indicated that the anisotropic PEGDA-ASF valve can produce appropriate surface morphology by dynamically adjusting the movement of bending area during the opening process. Hence, anisotropy of PHVs with bio-inspired layered fibrous structures played important roles in mechanical and hydrodynamic behavior mimicking native heart valves.

Roughness of the nuclear reactor pipe inner surface depending on the reactor operating time

During operation of nuclear reactors, there are various factors that affect the nuclear plant piping leading to erosion of the pipe inner surface and an increase of its micro-relief (roughness). Metal corrosion occurs and spreads faster on a surface having a higher value of the roughness parameter. Failure through erosive wear of the parent metal takes place predominantly in the pipe bend area. The roughness of the pipe inner surface has a sizeable effect on the signal attenuation in the process of the pipe wall ultrasonic testing. Defective main pipeline segments were cut out during preventive repairs from which samples with different operating times were taken. Five defective pipe segments of the austenitic 12Kh18N10T grade steel cut out of a high-pressure reheater’s piping and five defective pipe segments of the perlite-class steel of grade 20, after different operating times, were used to determine experimentally the actual value of the pipe inner surface roughness. Besides, a piece of a new Ø273 × 12 pipe of the 12Kh18N10T steel and a piece of a Ø159 × 6 pipe of grade 20 steel were cut out. The inner surface roughness was measured for different segments. Dependences of the roughness value on the operating time and the pipe segment type have been obtained. Company specimens were fabricated with the inner surfaces having the roughness corresponding to various pipe operating times. This made it possible to take into account the influence of the inner surface roughness on the signal attenuation in the process of the weld integrity ultrasonic testing and during ultrasonic measurements of the weld adjacent zone grain size value following the weld repair.

Desain Konstruksi Press Tool Sebagai Alat Bending Bentuk V Dengan Garis Bending Max. 300mm

Nowadays, the process of metal forming in the machining industry and welding workshop is developing very rapidly especially in the plate bending process. The bending process is the formation of metals which generally use plates or rods of both ferrous and non-ferrous metal materials by bending, which in the bending process will cause stretching or stretching on the neutral plane axis along the bending area and produce a straight bend line. The use of appropriate technology machines has been widely used to increase productivity, efficiency, and effectiveness in the production process for community businesses, especially those in the regions. One of the appropriate technologies that might be applied in the bending process is a hydraulic jack press that is equipped with a press tool. Press tool is one type of product forming, cutting and bending tools from the basic material of sheet plates whose operations are using a press tool. The results of the design of press tool bending tool V have a length of 300 mm bending line, 33 mm bending width, 110 mm spring height, free step distance of 19 mm. The punch angle used is 85⁰ with the punch radius used is 1.5 mm while the die angle is 85⁰. The selected punch and die material is Steel AISI 1045 HV HR.

Designing and Manufacturing the Press Tool of Air Bending V Brake

Nowadays, the metal forming process in the welding machinery and machinery industry is developing very rapidly, especially in the bending process. The buckling process is a metal formation which generally uses sheet plates or rods from both ferrous and non-ferrous metals by bending, which in the bending process will cause a stretching or stretching on the neutral axis of the field along the bending area and producing a straight bending line. Appropriate technology machines have been widely used to increase productivity, efficiency, and effectiveness in the production process for community efforts. One of the appropriate technologies that can be applied in buckling is a tool equipped with a press tool. Press tool is one type of tool for the formation, cutting and bending of products from the base material of sheet plates whose operation uses a press machine. In this study, a V brake bending tool has been produced which has a capacity that is bending line length 300 mm, bending width 33 mm, spring height 110 mm, free step distance 19 mm, spring load received 263,820 N and material capacity that can be bent is a thickness of 3 mm, the punch angle used is 85⁰ with a punch radius used which is 1.5 mm while the die angle is 85⁰

Disparities in Temporal and Geographic Patterns of Myocardial Infarction Hospitalization Risks in Florida.

Knowledge of geographical disparities in myocardial infarction (MI) is critical for guiding health planning and resource allocation. The objectives of this study were to identify geographic disparities in MI hospitalization risks in Florida and assess temporal changes in these disparities between 2005 and 2014. This study used retrospective data on MI hospitalizations that occurred among Florida residents between 2005 and 2014. We identified spatial clusters of hospitalization risks using Kulldorff’s circular and Tango’s flexible spatial scan statistics. Counties with persistently high or low MI hospitalization risks were identified. There was a 20% decline in hospitalization risks during the study period. However, we found persistent clustering of high risks in the Big Bend region, South Central and southeast Florida, and persistent clustering of low risks primarily in the South. Risks decreased by 7%–21% in high-risk clusters and by 9%–28% in low-risk clusters. The risk decreased in the high-risk cluster in the southeast but increased in the Big Bend area during the last four years of the study. Overall, risks in low-risk clusters were ahead those for high-risk clusters by at least 10 years. Despite MI risk declining over the study period, disparities in MI risks persist. Eliminating/reducing those disparities will require prioritizing high-risk clusters for interventions.

Late Quaternary slip rate of the Central Sierra Madre fault, southern California: Implications for slip partitioning and earthquake hazard

The Sierra Madre fault system accommodates contraction within a large restraining bend area of the San Andreas fault along the northern margin of the Los Angeles metropolitan area in southern California. Reverse slip along this fault system during earthquakes controls growth of the San Gabriel Mountains and poses a significant seismic hazard to the region. Here, we measure the late Quaternary slip rate of the Central Sierra Madre fault (CSMF) using analysis of high-resolution topography combined with cosmogenic 10Be surface exposure dating and post-IR IRSL geochronology. We mapped terrace and fan surfaces from three drainages that cross the CSMF and correlate them based on deposit character and geomorphic position. Cosmogenic nuclide and luminescence ages are consistent amongst the three prominent surfaces offset ∼5 to 28 m across the fault zone. Age estimates for these surfaces are 53 +21/−15 ka, 35 ± 9 ka, and 12±5 ka based on data from two dating methods at three locations, refined by inset age relationships. Estimated slip for these geomorphic markers is more uncertain than the measured vertical separation due to uncertainties in fault dip and ranges from 7.5 +5.4/−3.1 m to 58.5 +46.3/−14.4 m. Incremental dip-slip rate estimates from different age surfaces and locations overlap within uncertainty, with median values ranging from 0.6 to 1.1 mm/yr. The average slip rate for all three generations of markers is 1.1 +1.1/−0.4 mm/yr. This late Quaternary slip rate for the CSMF is slower than estimates based on interseismic geodetic data, and emphasizes the importance of contraction distributed across multiple structures south of the Sierra Madre fault when assessed against the geodetic shortening budget. Despite being the central portion of the broader Sierra Madre fault system, the CSMF has a slip rate similar to or lower than neighboring sections, suggesting that slip transfer onto other nearby faults control the along-strike pattern of deformation rate. Paleoseismic evidence indicates that the last earthquake on the CSMF was in the early Holocene, and the slip rate we estimate suggests that the accumulated elastic strain could produce many meters of slip in future earthquakes.

A novel approach of mapping landscape aesthetic value and its validation with rural tourism data

Landscape aesthetic research that emerged from the second half of the 20th century has become increasingly appreciated and popular in the last few decades. There are two main reasons for this. On the one hand, it was recognized the role of landscape aesthetics in land use and environmental planning, management and conservation. On the other hand, its definition among Cultural Ecosystem Services has made it clear that landscape aesthetics has significant impact on human well-being and there is a need to examine it in the concept of Ecosystem Services and, in particular, Cultural Ecosystem Services (CES). The mapping of landscape aesthetics is mostly based on the exclusive evaluation of objective, biophysical landscape factors. The aim of the research was to create the landscape aesthetic map of Hungary with a novel method based on human perception. For this, a questionnaire survey and a GIS approach were used. In order to better understand the role of factors influencing the aesthetic value of the landscape, value maps separately for land cover and elevation that are decisive for the landscape experience were prepared. To validate the results of the maps, and contribute a better understanding of the interrelationship between CES, a certain tourism product was chosen, and the connection between landscape aesthetics and the offer of rural tourism was examined in Hungary and in the Danube Bend priority tourism development area. Our findings show that there is a difference in the results of the objective (GIS-based) and subjective (questionnaire-based) assessment of landscape aesthetic value with the more important role of elevation in the latter. According to our tourism product-based analysis, which represents a niche approach in its kind, landscape values are higher in the areas with rural accommodation. At the same time, based on the results of the Danube Bend region, it can also be concluded that elevation and land cover together are crucial factors in landscapes considered to be the most valuable in aesthetic terms. The most direct practical application of our research is to orientate further tourism development of the new Danube Bend area designated in 2017.

Changes in Pipe Geometry in the Course of Sequential Creation of Stresses on the Inner Surface under External Thermomechanical Impacts

In modern high-technology industry, pipe bending technology is widely used. Pipe bends are an integral part of pipeline systems. The most widely used methods are techniques of cold pipe bending accompanied by a number of negative phenomena such as reduction in the wall thickness on the outer side of the bend, ovalization of the cross section, and formation of crimps. The article presents a study of the influence of deforming pipe billets by rolling under high tension on the structure and properties of the billet’s material. The pipe deformation by rolling under tension allows obtaining radially bent billets without destroying them and without causing obvious defects on the surface and microstructure. The tests were conducted using samples manufactured of 3sp (ASTM 284 grade D) and 12Cr18Ni10Ti (UNS S32100) grade steels. The microstructure was examined in accordance with GOST 5639–82 state standard, the mechanical properties were investigated in accordance with GOST 1397–84, and the microhardness—in accordance with GOST 9450–76. The effect of geometry changes of the pipe billets on their structure and properties was studied. It is shown that the pipe deformation by rolling leads to changes in the mechanical properties of the tested materials. The microhardness and strength values increase, while the grain points decrease. In the course of deformation, the microstructure of the material may change as a result of structural transformations (quenching). The plastic flow of the metal during the thermomechanical deformation suggests possible change in the pipe wall structure as a result of recrystallization and heat treatment of the material in the bend area, which requires further study and in-depth analysis of the technology in question.

Akuntabilitas Pengelolaan Tanah Bengkok Dalammeningkatkan Kinerja Perangkat Desa Di Kabupaten Jombang

This study aims to determine the extent to which the results of crooked land management on the performance of village officials in Jombang Regency. This research method uses a qualitative method by comparing the results of crooked land management with the results in the APBDes according to the instructions of the Regent Regulation (PERBUP) Number 10 of 2018 that the results of crooked land management must be included in the APBDes. Data collection techniques are carried out through interviews and collecting secondary data. Determination of the observation area was carried out by means of a study case, meaning that it considered the criteria for bent area, namely the widest, medium and narrowest bent soil in Jombang Regency. The results of this study indicate that village heads and village officials prefer the management of crooked land with a leasing system rather than being self-employed because the rental system of village equipment is avoided from the risk of crop failure and can find out how much revenue from leased land is rented to the community in one fiscal year. Reporting on the results of crooked land management at the research site can be said to be accountable because it has been included in the APBDes. With the results of the management of bent land, it turns out that it can improve the performance of village officials in Jombang Regency which includes: productivity, service quality, responsibility, responsiveness and accountability

Isolated superior mesenteric artery dissection: CTA features and clinical relevance.

To determine the detailed computed tomography angiography (CTA) features of isolated superior mesenteric artery dissection (ISMAD), aiming to improve the current understanding of ISMAD. We retrospectively analyzed 57 patients with confirmed diagnoses of ISMAD with CTA from June 2011 to June 2018 in our hospital. The superior mesenteric artery (SMA) angle, entry site of dissection, and features of both false and true lumen were analyzed individually. In general, middle-aged men with atherosclerosis (42.1%), hypertension (35.3%), or long-term smoking (33.3%) were the main populations. 80.7% of patients can be discharged successfully after conservative treatment. 87% of patients had a right (or almost right) SMA angle, and the entry site of dissection in 90% of patients occurred in the curved segment of the SMA. As a polymorphic disease, we can use the coded CTA features to delineate individual cases, including cases beyond the presenting classification systems. The diameter of the true lumen is the only different CTA feature between the conservative treatment group and the interventional treatment group (p = 0.000). The re-entry site (p = 0.501), thrombosis in the false lumen (p = 0.135), the distance between the entry site of dissection and SMA root (p = 0.133), and SMA branch involvement (p = 0.322) had no difference between the 2 groups. Based on CTA analysis, the bending area, especially in the SMA with right or nearly right SMA angle, is the most vulnerable anatomical region for the occurrence of ISMAD. The diameter of true lumen is the determined CTA feature for the decision of treatment. CTA should be recommended as a standardized diagnostic and classification tool for ISMAD.

Model Hubungan Kapasitas Rekatan Balok Beton Bertulang yang Diperkuat GFRP-S terhadap Lama Perendaman Air Laut

The construction of structures with reinforced concrete materials in coastal environments will face constraints in the form of chloride influences which can lead to a decrease in strength and even damage. One of the most popular reinforcement methods today is using a corrosion resistant Glass Fiber Reinforced Polymer (GFRP) material. This study was conducted to investigate the behavior of GFRP-S rectifying capacity in reinforced concrete beam reinforcement in 1, 3, 6, and 12 months. The test specimens consist of 10 reinforced beams with dimensions (15x20x330) cm that has been reinforced with GFRP-S in the bending area. Beams without immersion symbolized B0, immersion 1, 3, 6, and 12 months each given symbols B1, B3, B6 and B12. The test specimen is loaded statically until it fails. To record the data when testing is installed strain gauge and LVDT. From the result of the research, it can be seen that there is a decrease of GFRP-S rectification capacity in the test specimen after soaking in seawater. The value of the decrease in the capacity of the bonding can be predicted by using the equation

Flexible manufacturing chain with integrated incremental bending and Q-P heat treatment for on-demand production of AHSS safety parts

This work proposes a manufacturing chain that combines the two key technologies Incremental Swivel Bending (ISB) and Quenching and Partitioning (Q-P). While incremental forming methods offer chances for production flexibility, strain hardening often exhausts material’s ductility. Heat treatment processes can potentially renew the material’s capability to deform. Q-P, in particular, not only erases the influence of cold forming but also delivers advanced high strength properties (AHSS). Q-P has already been proposed for the incorporation of hot forming methods; however, integration methods for cold forming techniques represent a key research gap. The combined effects of cold forming of a Q-P suitable material in its initial pearlitic structure and subsequent Q-P heat treatment are investigated in this paper. Profiles of various cross sections are manufactured from a low alloyed, carbon enriched (42SiCr) steel and bent to various geometries by the flexible ISB process. An analytic model to determine the strain distribution caused by ISB is developed and validated within the bent areas by considering strain maps, local material properties and curvature distributions. Furthermore, material properties resulting from different Q-P treatments on the previously bent sections are evaluated with respect to accelerated heating gradients from quenching to partitioning. Tensile test specimens, locally extracted from the bent arcs, confirm the elimination of any remaining strain hardening after the heat treatments. Moreover, due to considerably high ductility at high tensile strength levels, the evaluation of energy dissipated during tensile tests demonstrates the Q-P treated material’s high potential to absorb energy even at elevated strain rates. The suggested manufacturing chain, combining ISB and Q-P, enables high production flexibility and delivers advanced high strength properties for the production of lightweight components, suitable for energy absorption at high strain rates, e.g. crash structures in cars.

Erosion Mechanism and Sensitivity Parameter Analysis of Natural Gas Curved Pipeline

With the deepening of natural gas exploitation, the problem of sand production in gas wells is becoming more and more serious, especially in high-yield gas wells. The solid particles in natural gas are very likely to cause erosion and wear of downstream pipelines and throttling manifolds, which makes the pipeline ineffective. Once the pipeline is damaged, the natural gas leaks, which may cause serious catastrophic accidents. In this paper, the impact of sand particles on the pipeline wall is predicted by the analysis of the research on bent and continuous pipeline combined with particle collision model. The parameters of different particles (particle shape factor, particle velocity, and particle diameter), different bent parameters (angle, diameter, and curvature-to-diameter ratio), and the influence of different continuous pipeline parameters (assembly spacing and angle) are explored on the erosion and wear mechanism of curved pipeline. The results show that the shape of the particles has a great influence on the wear of the curved pipeline. As the shape factor of the particles decreases, the wear tends to decrease. The bent area is subject to erosion changes as the particle parameters and piping parameters. The increase in pipeline diameter is beneficial to reduce the maximum and the average erosion wear rate. When the bent angle of the pipeline is less than 90 deg, the maximum erosion wear rate is basically the same. But when it is greater than 90 deg, it decreases with the increase in the bent angle. When the assembly angle of double curved pipeline is between 0 deg and 60 deg, the elbow is subject to severe erosion wear. At the same time, increasing the assembly spacing is beneficial to reduce the erosion wear rate. The research can provide a theoretical support for subsequent engineering applications.

Simulation of thin-walled workpieces ends expanding for pipelines making

Experience of pipelines operation shows that their failures are often connected with thinning of walls in bending areas and with abrupt transition from one wall diameter to another. It is possible to make this transition smoother by using of connecting pipes with variable diameter. Such parts can be obtained by forming process of expanding. In this paper, the process of cold expanding of the end of thin-walled tubular workpiece, which is made from aluminium alloy AMg6M, against hard die, is investigated by finite-element method in ANSYS. It is used the saddle-shaped die, which makes it enable to produce connecting branches similar to the form of two joined pipes with specified blending radius. It has been investigated maximal and residual stresses in deformed part, as well as wall thinning. This stresses do not exceed tensile strength of the material. Therefore, it has been proved the possibility to obtain connecting pipes per one processing step, which do not require subsequent mechanical treatment. Wall thinning corresponds to technological norms.

Diagnosis of abnormal temperature rise observed on a 275 kV oil-filled cable surface — A case study

This paper presents a case study on a 275 kV oil-filled cable. The condition assessment and diagnosis are based on analysis of cable surface temperature in relation to its current load and insulation dielectric loss. The work was initiated by a local abnormal temperature rise of 5.2 °C in cable surface temperature, which was observed during a routine inspection. The temperature rise occurred at bend area with a length of approximately one metre in the Blue phase. No PD activity was identified using on-line PD measurement. The relation between cable surface temperature, cable core temperature and cable insulation condition was then simulated based on the thermal model of power cables. According to simulation analysis, poor condition of cable insulation or oil from an oil duct penetrating a region under the cable surface were identified as possible reasons for the problem observed. An in service X-ray scanning technique was employed for further investigation and to aid diagnosis. The X-ray images revealed a slight distortion of the PVC sheath and the presence of multiple voids between cable insulation paper and the lead sheath. It was concluded that an oil leakage from the oil duct to the voids under the cable lead sheath was responsible for the local cable surface temperature rise. The result removed the concern of incipient cable breakdown, and a potential unplanned outage.