Hairpin Bend Research Articles

Application of passive vortex generators to enhance vertical mixing in an open raceway pond

A novel use of vortex generators in a raceway pond is described here, with the flow field quantitatively simulated using computational fluid dynamics using the large eddy simulation turbulence model. Persistence lengths of the swirling motion generated by the vortex generators indicate that significant vertical mixing can be achieved by placing vortex generators in the straight section opposite the paddle wheel, downstream of the first hairpin bend. Relatively simple vortex generators are capable of creating stronger swirling motions that persist for a longer distance than those created by the paddle wheel. For optimal performance, vortex generators are positioned side by side but in opposite directions, and their diameters should be equal to or slightly less than the desired liquid depth. The optimal length of a 0.18 m diameter vortex generator in a 0.2 m deep pond was determined to be 0.3 m. Furthermore, it has been demonstrated that a longer persistence length is achieved by inducing a swirling motion with its rotational axis parallel to the primary flow direction.

Accident Prevention and Traffic Control at Hill Stations using Machine Learning & IoT

Accidents are a prevalent concern in hilly areas, particularly at hairpin bends, leading to both traffic congestion and endangering human lives. When a vehicle becomes stranded or an accident occurs at a hairpin bend, it often results in frustrating traffic jams that hinder the resolution of the issue and the management of the accident. These challenges are particularly troublesome in hilly regions and pose difficulties in accident prevention and traffic control. To tackle these issues, the Accidents are a prevalent concern in hilly areas, particularly at hairpin bends, leading to both traffic congestion and endangering human lives. When a vehicle becomes stranded or an accident occurs at a hairpin bend, it often results in frustrating traffic jams that hinder the resolution of the issue and the management of the accident. These challenges are particularly troublesome in hilly regions and pose difficulties in accident prevention and traffic control. To tackle these issues, the study seeks to offer a comprehensive solution to mitigate these drawbacks. We have conducted a thorough analysis of various research papers and have identified effective methodologies to address the unique challenges presented by hairpin bends in hilly terrains. By employing these proven methodologies, the primary objective of the study is to save lives, prevent accidents, and efficiently manage traffic in hilly areas. By implementing these solutions, we aim to make travel in hill stations safer and more efficient. This includes reducing the risks associated with accidents and alleviating the inconveniences caused by traffic congestion at hairpin bends.study seeks to offer a comprehensive solution to mitigate these drawbacks. We have conducted a thorough analysis of various research papers and have identified effective methodologies to address the unique challenges presented by hairpin bends in hilly terrains. By employing these proven methodologies, the primary objective of the study is to save lives, prevent accidents, and efficiently manage traffic in hilly areas. By implementing these solutions, we aim to make travel in hill stations safer and more efficient. This includes reducing the risks associated with accidents and alleviating the inconveniences caused by traffic congestion at hairpin bends.

Machine Learning-based Intelligent Smart Warning System in Twisty Swerve in Hill Station using IoT

The surveyed reports state that about 10% of car accidents in the hilly areas happen on curved roads. It is risky to drive through curves and bends. Therefore, this work suggests a hairpin bend road collision prevention system using Internet of Things (IoT). The proposed design employing IoT strives to prevent the collisions by initiating warning alarms on detecting vehicles on the either side of the hairpin bend. The detection of the vehicles in the either side is performed using an ultrasonic sensor.

The Design Vehicle Steering Path Construction Based on the Hairpin Bend Geometry—Application in Roundabout Design

A prerequisite for a well-designed roundabout is the definition of the design vehicle movement geometry and its turning envelopes. This is because kinematic and dynamic requirements lose their importance due to low driving speed. In this paper, the investigation of the deviations of design vehicle steering paths for straight passage through the roundabout constructed according to the two approaches is presented. The first approach (A-1) includes the application of short, straight lines between the adjacent arcs on the path, and the second (A-2) implies the application of consecutive circular arcs. A computer simulation of vehicle movement was conducted using the Autodesk Vehicle Tracking 2020 software. The results showed that A-2, a faster and simpler approach, is applicable with caution, as the resulting turning envelopes derived from this approach are more offset from the roundabout centers compared to the A-1 approach. A total of 72% of right-hand-side path and resulting right-hand-side design vehicle body and chassis turning envelope deviations were between 0.00 and 0.15 m, 27% were over 0.15 m, and 7% were over 0.25 m. This results in larger roundabout entry and exit widths as well as the need for large lateral clearances for entries and exits on roundabouts where heavy pedestrian traffic on sidewalks is expected. The noted offset of left-hand-side design vehicle trajectories on the circulatory roadway (which was mostly between 0.05 and 0.15 m) could have a positive impact on the deflection around the central island.

Mountain Roads’ Geometric Design: Methodological Proposal for Hairpin Bend Design/Retrofitting

Mountainous roads often have to overcome considerable differences in height, which is why hairpin bends find a valid and common use. Despite this, there is a lack of specific international standards. Given the absence of a national standard governing the mountain roads’ design, in Italy, as in many other countries, the Swiss standard SNV 640198a is generally applied. This standard does not guarantee the correct geometric design of hairpin bends for Italian vehicle fleets and fleets according to the Directive 2002/7/EC. In this paper, the authors have developed a new methodology based on the Swiss standard upgrade, which is applicable internationally. Starting from hairpin bends’ geometric layouts provided by SNV 640198a and from related considerations, respectively, to the gyration formulae use and to swept path analysis’ simulations, they developed new planimetric layouts compatible with the vehicle fleet and with the cross-sectional dimensions of Italian roads. In this way, a generally valid methodology applicable to any international context was defined. In particular, the study allowed the definition of new geometric layouts to be used in hairpin bend design/retrofitting when it is necessary to guarantee the simultaneous entry into the bend of a 12 m long bus, and a car travelling in the opposite direction. Finally, the proposed methodology was applied to a mountain road case study in the Lucanian Dolomites area; an area of great tourist, cultural and environmental interest in southern Italy.

IoT Based Accident Prevention System for Hairpin Bend Roads

According to survey, 10% of the total vehicle accidents happen on curved segments in hill stations. It is risky while driving in bends and curves. In order to provide solution, an IoT based Accident Prevention System for Hairpin Bend Roads has been proposed in this work. The objectives of the proposed work are to provide a safe and comfort hill travel by avoiding accidents mainly at the Hairpin bends and U curves, and to alert the drivers of both the vehicles approaching the bend, by generating traffic warning signal that indicates the arrival of a vehicle ahead on the opposite side of the bend. The proposed system includes ultrasonic sensor to detect any vehicle reaching the hairpin bend and alert immediately the vehicles on the other side by enabling an yellow signal. In the proposed work, NodeMCU is used as a processing element which supports ESP-NOW communication technology to enable two-way communication. Therefore, this system reduces the incidence of vehicle collision especially in the forest or hilly region which has poor internet connection. To solve connectivity issues, it has been implemented with machine-to-machine communication protocol without internet.

Vehicle Alerting and Accident Detection System at Hairpin Bend Curves Using IOT

In the developing countries accident is the major cause of death. “Speed Kills”, but still people don’t care enough to act safe while driving on road. Road traffic accidents and deaths caused by them are most critical issues now days. It is also impacting the country’s economy. According to Million Death Study (MDS) about 2.3 million people die in India per year. In that 137 thousand is because of road accidents. That is about 377 people per day. In that 3.7% because of failed to look the road. We can see that many of them are curve roads. In the mountain roads there will be tight curves and the roads will be narrow. In these kinds of situations the driver of a vehicle cannot see vehicles coming from opposite side on the roads. Thousands of people lose their lives each year because of this problem. Since we are talking about mountain roads here other side might lead to a cliff and heavy bends. The solution for this problem is alerting the driver about the vehicles coming from opposite side in Ghats sections. This is done by keeping an ULTRASONIC SENSOR on one side of the road before the curve and keeping a LED light after the curve, so that if a vehicle comes from one end of the curve, sensor senses and LED light glows at the opposite side. By looking at the LED light on/off criteria driver can be alert and can slow down the speed of the vehicle.

Accident Prevention Road Safety Model with Speed Breaker Power Generation

The implementation of the Collision Avoidance System is aimed to reduce the risks of collisions at the hairpin bend on a Hilly track, Ghats, or other Zero visibility turns The proposed system contains a set of proximity sensors, warning lights combined with a convex mirror is installed by the side of the road. Moreoverthis project is about the design and manufacturing of speed breaker power generator. In this project we are trying to utilize one such source. In this report we explain in detail the various stages of research, design and manufacturing which was involved in the construction of various components such as springs, generator, rack and pinion mechanism.

Computational MHD analyses in support of the design of the WCLL TBM breeding zone

The Water-Cooled Lithium Lead (WCLL) is a blanket concept pursued in the framework of Test Blanket Module (TBM) campaign in ITER. Even if the liquid metal is circulated slowly in the component, magnetohydrodynamic (MHD) pressure losses are still expected to be significant.The aim of this paper is to assess the MHD pressure losses in the TBM frontal part, also called Breeding Zone (BZ). There, important contributions are caused by the manifold interface, the presence of cooling pipes obstructing the fluid movement, a sharp hairpin bend, and non-uniform wall thickness of the walls. Direct numerical simulation of 2D and 3D MHD flows is used to estimate the head loss for each one of these elements.A scaling law is derived to allow quick estimate of the pressure loss from reference parameters. The main contribution to the head loss is caused by the windows that connect the BZ with the manifold.

ARDUINO based accident prevention and auto intimation system

<p>Often modern cars have a collision avoidance system built into them known as Pre-Crash System, or Collision Mitigation System in order to reduce the collision. But majority of vehicles on the road, especially heavy motor vehicles lack in such a system. In this paper, the implementation of the Collision Avoidance System is to reduce the risks of collisions at the hairpin bend on a Hilly track, Ghats, or other Zero visibility turns. The proposed system contains a set of IR sensors, LEDs, etc. It uses four IR sensors, which are placed on either side of the hairpin bend. The sensors are mutually exclusive and are connected to LEDs through wires. Based on the output of sensors, the LEDs will glow and start alerting the other vehicle approaching from the other end, Hence the drivers will decrease their speeds which would help in preventing collision. The LEDs will help the drivers in detecting the position of the vehicles on either side of the bend. During climatic conditions like fog, snow, etc, the visibility of the drivers would decrease due to which they will not be able to see the LEDs, Hence, a collision may take place. To bring help as soon as possible to the injured, we have also made a proposed system which would alert the nearby hospitals that an accident has taken place. We have used Arduino UNO, GSM sim module and these will be kept inside a black box which will be inside the, car safe from breakage during the accident.<strong></strong></p>

Characterization of Rectangular Copper Wire Forming Properties and Derivation of Control Concepts for the Kinematic Bending of Hairpin Coils

As a result of the continuously growing demand for electric vehicles, innovative production technologies must be developed to fulfill the high automotive requirements for productivity and quality in the manufacturing of electric drives. By providing advantages regarding the degree of automation, the productivity as well as the attainable filling factors in comparison to established round wire winding technologies, the hairpin technology shows a high potential for meeting the requested specifications but also technological weaknesses, especially concerning the process reliability. The referring production process of stators is normally based on the spatial forming of open, hairpin-shaped coils of enameled flat copper wire as well as subsequent joining and contacting processes. Consequently, the hairpin coils represent the elementary components of the process chain and can be either shaped by robust tool-bound or flexible kinematic bending processes that enable the shaping of different contours at moderate tool costs. In this paper, the essential mechanical forming and product properties of flat copper wires with different dimensions and insulation coatings are characterized by means of uniaxial tensile tests as well as metallographic analyses of the material structure, at first. Subsequently, the identified forming properties are correlated to the applied manufacturing processes drawing, rolling as well as continuous extruding and considered as limits of possible material variations. To evaluate the effect of fluctuating wire qualities on the robustness of kinematic hairpin bending processes, the fabrication tolerances are analyzed by finite element simulations, using the example of elementary kinematic bending operations and modeled changes of the material properties. Based on the knowledge of material-based process tolerances, different control concepts for the kinematic bending of hairpin coils are derived and compared based on technical as well as economic aspects.

Accident Prevention and Traffic Pattern Analysis System for Hilly Regions

In hilly regions, there will be a number of curves and hairpin bends. The roadway is one of the often-used modes of transport in these regions. Accident rate and death rate in hilly regions are increasing day by day. The roads in this region will definitely have bends and steep curves; hence, it is difficult to see the vehicles coming from the opposite side. The proposed system aims in reducing the risk of driving vehicle in the terrain region with hairpin bends and steep curves. The deployed controller with ultrasonic sensor senses the vehicle coming towards the bend and intimates it to the other side of the bend or curve; it gives three stages of LED alerts to the driver driving the vehicle from the opposite side of the hairpin bend or curve. It also senses the speed of the vehicle, if the vehicle speed is high, it will alert the drivers through the buzzer. These alerts will indirectly convey the drivers to slow down the speed of the vehicle. The foremost focus of the proposed system is to prevent accidents for the drivers and passengers in order to decrease the death rates in hilly regions. This system also provides a way for analyzing the number of uphill and downhill vehicles in the hill stations by storing the data in the cloud. The analyzed data is be viewed over the internet through a web application. The web application serves as a traffic pattern analyzer for people who wish to travel by that road.

Left-sided gallbladder: a systematic review of a rare biliary anomaly.

A left-sided gallbladder (LSGB) is a rare anatomical anomaly that is often not discovered until surgery. Two cases of LSGB managed with laparoscopic cholecystectomy (LC) stimulated this systematic review. The aims of this study were in LSGB to define the rate of pre-operative detection, variations in biliary anatomy, laparoscopic techniques employed and outcomes of surgery for symptomatic gallstones. A systematic review was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses principles. Fifty-three studies with 112 patients of which 90 (80.4%) had symptomatic gallstones. Pre-operative imaging was performed in 108 patients (96.4%) with an LSGB reported on imaging in 32 (29.6%) patients. The remainder of LSGB were discovered at surgery. Ultrasound detected an LSGB in three (2.7%) patients. Five variants of cystic union with the common hepatic duct (CHD) were identified. The most common (67.8%) was union on the right side of the CHD after a hairpin bend anterior to the CHD. A cholecystectomy for gallstone disease was performed in 90 patients, 23.3% open and 76.7% LC. Common variations in LC technique were different port site placement and techniques related to the falciform ligament to improve exposure. Common bile duct injury occurred in four (4.4%) patients. LSGB is a rare anatomical variation that in patients with symptomatic gallstones is usually discovered at surgery. Cholecystectomy is associated with a higher incidence of common bile duct injury.

Hairpin Bending Process

A flexible technique for hairpin bending enables the process to be accurate and free from physical damage, with geometric programming to speed up geometry definition

Effect of P Contents and Tube-shape on Stress Corrosion Cracks in Hair-pin Bending Copper Tube

銅の応力腐食割れに対する感受性は，Zn，P，As，Sb，Siなどの添加によって増大する．その中でもP，As，Sbは，極めて微量の添加量でも感受性を高める．Pは，銅管における重要な添加元素であり，最近になって，りん脱酸銅の約10倍のPを添加した合金（Cu-0.2～0.4％P合金）において，蟻の巣状腐食への耐性を示すことが分かっている．エアコンの熱交換器用伝熱管として使用される銅管での応力腐食割れは，これまでにほとんど発生しない事象であり，耐蟻の巣状腐食合金との関係は分かっていない．本研究では，銅管のP濃度と応力腐食割れの関係について，ヘアピン曲げの観点から調査を行った．

Strength and Microstructure of Copper Tube in Cross-Roll Straightening

The diameter and wall thickness of copper tubes used for heat transfer in heat exchangers have been decreased in order to improve performance and save resources. One of the problems related to the reduction in tube wall thickness and diameter is ensuring the workability of the products. Copper tubes used in heat exchangers are subjected to various types of processing, such as hairpin bending, expansion, and flaring. Since the necessary stiffness cannot be achieved in copper tubes with thin walls, defects such as buckling may occur. Copper tube manufacturers deal with such problems by fine control of the mechanical properties of the materials. This paper focuses on straightening used in tube manufacture as a potential machining method for providing precise control of mechanical properties. The strength and microstructure of a work-hardened copper tube before and after straightening was investigated.

Steric Crowding of the Turn Region Alters the Tertiary Fold of Amyloid-β18–35 and Makes It Soluble

Aβ self-assembles into parallel cross-β fibrillar aggregates, which is associated with Alzheimer's disease pathology. A central hairpin turn around residues 23-29 is a defining characteristic of Aβ in its aggregated state. Major biophysical properties of Aβ, including this turn, remain unaltered in the central fragment Aβ18-35. Here, we synthesize a single deletion mutant, ΔG25, with the aim of sterically hindering the hairpin turn in Aβ18-35. We find that the solubility of the peptide goes up by more than 20-fold. Although some oligomeric structures do form, solution state NMR spectroscopy shows that they have mostly random coil conformations. Fibrils ultimately form at a much higher concentration but have widths approximately twice that of Aβ18-35, suggesting an opening of the hairpin bend. Surprisingly, two-dimensional solid state NMR shows that the contact between Phe(19) and Leu(34) residues, observed in full-length Aβ and Aβ18-35, is still intact in these fibrils. This is possible if the monomers in the fibril are arranged in an antiparallel β-sheet conformation. Indeed, IR measurements, supported by tyrosine cross-linking experiments, provide a characteristic signature of the antiparallel β-sheet. We conclude that the self-assembly of Aβ is critically dependent on the hairpin turn and on the contact between the Phe(19) and Leu(34) regions, making them potentially sensitive targets for Alzheimer's therapeutics. Our results show the importance of specific conformations in an aggregation process thought to be primarily driven by nonspecific hydrophobic interactions.

An unusual foreign body lodged in cricopharynx of one year old child - a rare case report

Foreign body ingestion is common in children, but can be seen among adults also. Most common foreign bodies in children are coins, but marbles, button, batteries, safety pins and bottle tops are also reported. The best method of removing impacted foreign body remain controversial. Rigid endoscopic removal of foreign body is safe and effective, but requires General anaesthesia. The flexible fibreoptic endoscopic removal, which can be done under LA in outpatient department has gained great popularity over the past decade. One year old female child came with history of accidental ingestion of unknown foreign body since one day. child is asymptomatic and taking breast feeding, on clinical examination child is stable. On radiological study, antero-posterior and lateral view for soft tissue neck shows a flat surfaced metallic foreign body in lateral and antero -posterior view showed a hair pin bend foreign body at the level of 4,5 and 6 cervical vertebrae. Under GA and under high risk, rigid oesophagoscopy was planned and proceeded. A uncuffed endotracheal tube inserted with throat pack around it. Negus Rigid Oesophagoscope of paediatric size used. Oesophagoscope is reinserted for re-examination of foreign body impaction and any erosion of mucosa or perforation or any other second foreign body. The procedure went uneventfully and the patient shifted with Ryle's tube in-situ to paediatric ICU and discharged after 2 days.

Математическое обеспечение системы автоматизированного проектирования объектов производственно-транспортной инфраструктуры лесопромышленного комплекса

The mathematical software computer aided design (CAD) of objects of production and transport infrastructure in timber industry (TI) is given, feature of which is the following. Tasks of establishing the optimal placement options of spur road on felling and loading points along it are solved together. At the next stage, the structural design of collapsible coatings of spur roads and topping hair-pin bend is made, if such coating is provided. Depending on the characteristics of accepted structures of the brain and deep sections of spur roads its length in the cutting area.

Aberrant Community Architecture and Attenuated Persistence of Uropathogenic Escherichia coli in the Absence of Individual IHF Subunits

Uropathogenic Escherichia coli (UPEC) utilizes a complex community-based developmental pathway for growth within superficial epithelial cells of the bladder during cystitis. Extracellular DNA (eDNA) is a common matrix component of organized bacterial communities. Integration host factor (IHF) is a heterodimeric protein that binds to double-stranded DNA and produces a hairpin bend. IHF-dependent DNA architectural changes act both intrabacterially and extrabacterially to regulate gene expression and community stability, respectively. We demonstrate that both IHF subunits are required for efficient colonization of the bladder, but are dispensable for early colonization of the kidney. The community architecture of the intracellular bacterial communities (IBCs) is quantitatively different in the absence of either IhfA or IhfB in the murine model for human urinary tract infection (UTI). Restoration of Type 1 pili by ectopic production does not restore colonization in the absence of IhfA, but partially compensates in the absence of IhfB. Furthermore, we describe a binding site for IHF that is upstream of the operon that encodes for the P-pilus. Taken together, these data suggest that both IHF and its constituent subunits (independent of the heterodimer), are able to participate in multiple aspects of the UPEC pathogenic lifestyle, and may have utility as a target for treatment of bacterial cystitis.