Coil Spring Research Articles

Analysis of the Potency of Robusta Coffee (Coffea canephora) to Increase the Expression of FGF2, Collagen 1 and ALP in the Periodontal Ligament During Orthodontic Tooth Movement

Orthodontic treatment is relatively long and various efforts have been made to speed up the movement of orthodontic teeth. Coffee contains substances called caffeine (1,3,7 trimethylxanthine), chlorogenic acid and caffeic acid, as well as flavonoids which have antioxidant effects. Chlorogenic acid and caffeic acid are antioxidants that can reduce oxidative stress in osteoblasts and promote osteogenesis. The study aimed to analyze the expression of FGF2, Collagen 1 and ALP, on the movement of orthodontic teeth after administration of Robusta coffee extract. 24 wistar rats divided into 4 groups, namely groups C1 and C2: Rats were given orthodontic mechanical force (OMF) for 2 and 3 weeks and groups T1 and T2: Mice were given OMF and Robusta coffee extract for 2 and 3 weeks. OMF in mice (rats) was carried out by means of the right maxillary first molars teeth and on both maxillary incisors were given ligature wires. Then the right maxillary first molars moved to the mesial with a Niti closed coil spring. Observations were made on the day 15 and day 22 with immunohistochemical examinations to determine the expression of FGF2, Collagen 1 and ALP. The results indicated that administration of Robusta coffee extract for 2 and 3 weeks significantly increased the [expression of FGF2, Collagen 1 and ALP. The expression of FGF2, Collagen 1 and ALP (expression of GFß1, IGF1 and PDGF). The expression of TGFß1, IGF1 and PDGF during 3 weeks was greater than that at 2 weeks (p < 0.05. Robusta coffee extract can be used as an alternative ingredient in accelerating orthodontic treatment. HIGHLIGHTS Orthodontic treatment requires quite a long time and various efforts have been made to speed uporthodontic tooth movement, for example with drugs Robusta coffee extract contains ingredients that have antioxidant effects that can reduce oxidativestress on osteoblasts and promote osteogenesis Robusta coffee extract effectively increases the expression of FGF2, Collagen-1 and ALP which are bone formation markers GRAPHICAL ABSTRACT

Can the Nucleation Phase be Generated on a Sub-fault Linked to the Main Fault of an Earthquake?

We study the effects of seismic coupling, friction, viscous, and inertia on earthquake nucleation based on a two-body spring-slider model in the presence of thermal- pressurized slip-dependent friction and viscosity. The stiffness ratio of the system to represent seismic coupling is the ratio of coil spring K between two sliders and the leaf spring L between a slider and the background plate and denoted by s=K/L. The s is not a significant factor in generating the nucleation phase. The masses of the two sliders are m1 and m2, respectively. The frictional and viscous effects are specified by the static friction force, fo, the characteristic displacement, Uc, and viscosity coefficient, h, respectively. Numerical simulations show that friction and viscosity can both lengthen the natural period of the system and viscosity increases the duration time of motion of the slider. Higher viscosity causes lower particle velocities than lower viscosity. The ratios g=h2/h1, f=fo2/fo1, y=Uc2/Ucl, and m=m2/m1 are four important factors in influencing the generation of a nucleation phase. When s>0.17, g>1, 1.15>f>1, y<1, and m<30, simulation results exhibit the generation of nucleation phase on slider 1 and the formation of P wave on slider 2. The results are consistent with the observations and suggest the possibility of generation of nucleation phase on a sub-fault. Results exhibit independence of P wave at slider 2 on the shape and duration time of nucleation phase at slider 1.

Evaluation of systemic Omega-3 PUFAs effect on orthodontic tooth movement in a rabbit model: RCT.

To evaluate the effect of systemic administration of omega-3 fatty acids on orthodontic tooth movement (OTM) with histological analysis. OTM was induced in 20 adult albino New Zealand rabbits, divided into omega-3 and control groups, with nickel-titanium coil springs for 21 days. Omega-3 or saline was given every day via oral gavage during the experimental period. Animals were sacrificed for histomorphometric analysis of alveolar bone remodeling after 21 days of OTM. A significant difference in OTM amount was found in the third week of OTM with means of 1.445 ± 0.13 and 1.72 ± 0.15 for the experimental and control groups, respectively. Histomorphometric analysis showed a significant reduction in the area of active bone-resorptive lacunae and a significant increase in osteoblastic activity in the omega-3 group after 3 weeks. Strong evidence of the osteoclastic inhibitory effect of systemic omega-3 was found, which reduced the percentage and amount of OTM.

Optimization of suspension of rail vehicles with coil springs using marine predators algorithm

The topic of this paper is the usage of the algorithm of marine predator (MPA) in the optimization of the suspension of rail vehicles with coil springs. The aim is to reduce the mass of set of coil springs as the main parts of rail vehicles suspension. The optimized set of coil springs must satisfy the appropriate conditions related to the suspension characteristics, with the aim of achieving the required operation quality and running security of the observed rail vehicle. Starting from the bi-linear characteristic of rail vehicles suspension and the analytical description of its parameters, an optimization problem is formulated. It is composed of six optimization parameters, an objective function and 16 constraints (eight for each coil spring in the set). The developed approach is applied in two specific examples of suspension optimization of four-axled freight wagons, the first with axle load of 200 kN and the second with axle load of 225 kN. The optimization problem is resolved using MPA. The acquired results showed that the given optimization approach with MPA provide a significant mass decrease compared to conventional design method of rail vehicles suspension with coil springs. The mass decrease of one set of coil springs in both examples is about 15.5%. Given that each considered four-axled freight wagon has 16 sets of coil springs, the decrease of the total coil springs mass per wagon in both examples is more than 60 kg. Since certified rail vehicles are commonly produced in large series, the proposed approach can be very significant for increasing profitability in the rail vehicles industry.

Study on the dynamics characteristics and screening performance of the disc spring vibration screen

The disc spring system is applied to the vibration screen, which can effectively reduce the exciting force and improve screening capacity. In this work, the dynamic characteristics and screening performance of the disc spring vibration screen are studied. The modal simulation and experimental results show that the model vibration direction at first natural frequency is consistent with the working direction of the vibration screen. Moreover, the trajectory analysis and discrete element screening simulation prove that the disc spring vibration screen has better screening performance than the coil spring vibration screen. Eventually, by comparing required exciting force under the same amplitude, fatigue life of the spindle bearing, and energy consumption between the coil spring and disc spring vibration screen, it can be found that disc spring vibration screen has better mechanical properties, higher reliability, and lower energy consumption.

The in vitro biomechanics of anterior arch expansion using fixed lingual appliances with coil springs or archwire stops.

The presented study investigates differences in the biomechanics of straight and mushroom fixed lingual appliances when implementing coil springs and stops for anterior arch expansion. An in vitro orthodontic simulator was used to measure three-dimensional forces and moments on each tooth of a simulated maxillary arch. Mushroom and straight archwire forms of 0.016″ NiTi round archwire were considered, using 0.010″ × 0.030″ NiTi open coils and 0.016″-0.018″ archwire stops (n= 44 per group). Teeth in the anterior dental arch were moved from a neutral to crowded position to replicate anterior crowding of central and lateral incisors. Forces and moments of interest for lateral incisors and first premolars were compared using repeated measures mixed multivariate analysis of variance (α= 0.05). Three comparisons between straight versus mushroom archwires and two comparisons of coil springs vs. stops were not statistically significant. Overall, it was found that the use of a straight lingual archwire produced larger differences in forces and moments between using stops and coil springs than when using a mushroom archwire. Using stops produced larger forces and moments for both types of archwires as compared to using coil springs. The largest expansion forces were produced using straight archwires with stops, exceeding 3.0N of force. Straight archwires with coil springs produced the lowest expansion forces on lateral incisors, just exceeding 1.5N. The findings of this study have elucidated significant differences in the biomechanics of transverse arch expansion using straight or mushroom fixed lingual appliances with coil springs or stops.

Stiffness calculation of the nonlinearly elastic clutch with compressible metal inserts

In the drives of various machine units, clutches are widely used as a connecting element transmitting energy from one part of the machine to another. Among them, permanent clutches are prevailing, and they include elastic clutches with metal elements, such as cylindrical rods, cylindrical coil springs, tapes, spring holder packs and plate packs. The torsional rigidity is an important characteristic of clutches. Study results of the elastic non-linear clutch with a soft characteristic are presented. Elastic elements are plates exposed to buckling during compression. The study was performed numerically by the finite element method using the ANSYS R17.0 Academic software applied package. On the basis of the data obtained, analytical dependencies are proposed to determine the clutch torsional stiffness and to calculate the elastic elements strength. Description is provided of the tests carried out on the elastic elements to assess the analytical dependencies accuracy, which showed their suitability in practical calculation of strength and stiffness.

Reliability-based fatigue life assessment using random road load condition and local damage criteria

This study presents a fatigue reliability assessment of a vehicle coil spring based on random road load conditions for fatigue life characterisation. Fatigue life data characterisation was carried out to accelerate the durability analysis by retaining the higher amplitude cycles in the original strain signals and thus indicate the fatigue damage. To collect experimental data, road testing was conducted using various road profiles, which contributed significantly to the fatigue failure performance of the vehicle coil spring. Fatigue reliability analysis was performed to assess the failure behaviour of the coil spring utilising the probabilistic Gumbel distribution model to forecast the probability distribution of the fatigue life data. Furthermore, the highest and lowest mean-cycles-to-failure (McTF) of 5.44 × 107 and 2.46 × 105 blocks were estimated for the Coffin-Manson and Smith-Watson-Topper models from the highway and rural road profiles. The findings demonstrate that the lowest hazard rate corresponded to the highest McTF, making this an acceptable model to be implemented in reliability assessments of road profiles. Hence, the fatigue reliability assessment provided a hazard rate based on the fatigue life predictions for risk assessments when characterising the fatigue life data.

In vivo Comparison of Volume of Interest Determination on Maxillary Bone Regeneration in Orthodontic Treatment: Cone-Beam Computed Tomography Versus Micro-Computed Tomography

Orthodontic treatment can result in relapse, side effects associated with Orthodontic Tooth Movement (OTM) are root resorption, bone loss, and gingival inflammation which impairs long-term stability during orthodontic treatment. OTM creates a gap causing relapse after orthodontic treatment. Regenerate bone to prevent relapse after orthodontic treatment. Volume of interest (VOI) measurement by (3 Dimension) 3D imaging Cone-beam computed tomography (CBCT) or Micro-computed tomography (Micro-CT) in vivo. In vivo tests were carried out on 6 Wistar rats aged 5 months and performed 10gf maxillary Molar 1 (M1) withdrawal with 0.010 inch Nickel-Titanium (NiTi) and 8 mm close coil spring, maxillary separation was carried out by CBCT and Micro-CT tests. The tensile force of the orthodontic appliance in the compressed and tense area is a characteristic of OTM causing changes in remodeling. Alveolar bone displacement can occur when tooth roots move through the alveolar cortical bone occurring during OTM. Measurements on samples from CBCT and Micro-CT to investigate the accuracy and reproducibility of landmarks. CBCT resolution 0.0131 µm / pixel and Micro-CT 5.7 µm/pixel, Micro-CT can determine VOI boundaries. Comparison of VOI from CBCT and Micro-CT showed VOI CBCT 9.99% and VOI Micro-CT 22.22%. 3D Micro-CT visualization is more detailed than CBCT, so VOI can be determined easily and more accurately. Detailed, clear, and accurate 3D Micro-CT visualization in the determination of VOI versus CBCT.

Investigating the Effectiveness of Low-Level Laser in Reducing Root Resorption of the Upper Incisors During Intrusion Movement Using Mini-Implants in Adult Patients With Deep Overbite: A Randomized Controlled Clinical Trial.

Deep bite is a common characteristic of malocclusion, and many methods are used to treat it, including mini-implants used for the intrusion of the upper incisors. Orthodontically induced inflammatory root resorption (OIIRR) is an inevitable and unexpected side effect of orthodontic therapy. However, resorption of the root could be affected by the type of tooth movement, such as intrusion. Several studies have indicated the effectiveness of low-level laser therapy (LLLT) in accelerating orthodontic movement, but studies that have evaluated the role of this laser in reducing the risk of OIIRR have been limited. This trial aimed to investigate the effectiveness of LLLT in reducing the resorption of the roots of the upper incisors during their intrusion in the context of deep bite correction. Thirty patients (13 males, 17 females; mean age 22.4±3.37 years) with deep overbite were recruited and allocated to the laser or the control groups. Mini-implants were inserted between the roots of the upper central incisors and the lateral incisors from the labial aspect at the gingival-mucosal junction on both sides with a force of 40 g on each side through an NiTi coil spring. A low-level laser (Ga-Al-As) with 808 nm wavelength in a continuous mode, with the parameters250 milliwattpower output, 4 Joules/point energy density, and 16 seconds irradiation per point, was applied to the root of each of the upper incisors. The laser was applied on the first day of the upper incisor intrusion (T1), then on days 3, 7, and 14 of the first month. In the second month, the laser was applied every 15 days, adjusting the spring strength every four weeks until the end of the intrusion stage (T2), which was determined by reaching a normal overbite. As for patients in the control group, the strength of the nickel-titanium springs was adjusted every four weeks to the required strength of 40 g on each end until reaching a normal overbite. There was a volumetric decrease in both groups' upper central and lateral incisors roots, and this decrease was statistically significant (P<0.001). However, the difference between the two groups was not statistically significant in each central and lateral incisor volume root (P=0.345 and 0.263 for U1 and U2, respectively). Also, both groups had a linear decrease in upper central and lateral incisors roots, which was statistically significant (P<0.001). At the same time, the difference between the two groups was not statistically significant in each central and lateral incisor root length (P=0.343 and 0.461for U1 and U2, respectively). The low-level laser irradiation using the current protocol did not significantly affect the amount of root resorption induced by incisor intrusion in the experimental group compared to the control group.

Impact and Assessment of Suspension Stiffness on Vibration Propagation into Vehicle.

The impact of transport-induced vibrations on people is a particularly important problem. Sudden or intensifying vibration phenomena of a local nature may compromise safety, especially in transport. The paper addresses the results of research on the impact of spring stiffness parameters on the propagation of vibrations in the vehicle structure using simple amplitude and frequency measures. The use of the developed method of selective multi-criteria analysis of frequency bands made it possible to compare the vibrations recorded in the vehicle with a new or worn coil spring. The results of the present study allow the development of a large data base in which all signals are classified by the exploitation parameters and location of the propagation of vibration in the vehicle. The most important findings and achievements of the presented study are the testing of actual suspension components with real damage under controlled conditions, the identification of the vibration propagation path from the wheel to the driver and passenger feet, the quantitative comparison of vibrations affecting humans in the vehicle (through the feet), and the frequency decomposition of vibration for selected bands. These findings improve the proper interpretation of the developed measures and, as a result, the difficulties in using this knowledge at the engineering level, for example, in the design and construction improvement stage. Therefore, innovation points and engineering significances are a method of selective multi-criteria analysis of frequency bands and have potential applications in diagnostics and the design of suspension systems and in terms of passengers' comfort.

Magnetorheological semi-active shock mitigation control: Part II: System extension and application analysis

In Part I of this work, the dynamic model of drop-induced shock mitigation based on magnetorheological (MR) energy absorber (EA) was deduced. The shock mitigation control effectiveness of constant force control method and optimal Bi number control method were compared based on Bingham model and resistor-capacitor (RC) operator-based hysteresis model. In this part, to further explore the possibility of the application of MREA in the shock mitigation control system, a single-degree-of-freedom (SDOF) shock mitigation control system is built with MREA connected in parallel with a coil spring, which is then connected in series with a vehicle tire to build a one-fourth vehicle suspension shock mitigation control system. Next, the constant force control method and optimal Bi number control method are extended to the SDOF shock mitigation control system. Based on the concept of the optimal Bi number, a two-degree-of-freedom (2DOF) optimal Bi number control method applied to the one-fourth vehicle suspension system is proposed by decoupling and recoupling the damping and stiffness of the vehicle suspension system. Using the control methods conducted in Part I, the motion state of the drop-induced shock mitigation process is simulated and analyzed. The control performances of the control methods in the SDOF shock mitigation control system are compared. Besides, the average velocity change rate (AVCR) and velocity-acceleration conversion ratio (V-ACR) are used to evaluate the effectiveness and stability of the control methods. Finally, the conclusion that the 2DOF optimal Bi number control method can effectively realize the shock mitigation control of a one-fourth vehicle suspension system is verified.

Fatigue analysis of coil springs in the primary suspension of a railway vehicle based on synthetic spectrum for time-varying vibration load

The fatigue life of coil springs is usually predicted with a stationary Gaussian vibration load and deterministic structural parameters. However, the obtained fatigue life is inconsistent with the observed fatigue life of fractured springs which varies within a wide range. The work aims to propose a method to predict the fatigue life of the coil spring by considering the time-varying vibration load, i.e., root mean square (rms) varies with time and the uncertainties of geometric parameters. First, a synthetic method for time-varying vibration loads is proposed. The time-varying load is decomposed into multiple stationary Gaussian short samples represented by their power spectral density (PSD). These PSDs are synthesized according to the distribution characteristics of spectral values, in which data that are non-Gaussian are processed with the Johnson system. Second, the influence of parameter uncertainties in the coil spring is studied by a Monte Carlo analysis of the stress frequency response function. Finally, the fatigue life is calculated and compared with the results predicted by using the measured stress. The results show that the synthetic spectrum has almost the same damage potential as the measured time-varying load. In comparison with results predicted from the measured stress, the synthetic spectrum gives much better estimates of the fatigue life of the coil spring than the average spectrum. Parameter uncertainties of coil springs significantly affect fatigue life and should be taken into account.

Finite element analysis of coil spring by using carbon fibre, carbon steel and epoxy resin materials

Coil springs stay one of the oldest suspension mechanisms. They are habitually used even now, particularly in the field of two-wheeled vehicles. The design of coil springs is based on compressive energy components. Location, celerity in addition to placement of the spring provides the thrust in the fork attachment positions. One more portion that requests focus, is the automobile industry which has given improved curiosity in exchanging steel springs for composite materials due to its high strength-to-flexibility ratio. Hence, examination and study of material become correspondingly vital to check the behavior of composite coil springs. In this study, analysis was done on composite coil springs using carbon fiber, carbon steel, and epoxy resin material. 3D modeling is prepared with CATIA V5 and Finite Element Analysis is done on ANSYS. The results show that among epoxy resin, carbon steel, and carbon fiber, carbon steel provides more strength compared to epoxy resin and carbon fiber. In finite element analysis, epoxy resin material has shown maximum deformation and has maximum stress concentration. Further various composite materials along with analysis (compression, tensile, wear as well as tear) are concluded by referring to the results in use from the FEA. From the results, carbon steel is found to be a superior material for coil springs.

A Review on Vehicle Suspension with Urethane Buffer

Abstract: Elastomers are extensively used in the automobile industry due to their excellent damping and energy absorption characteristics and low cost, to isolate the structures from vibration and shock loads. In this study, the aim is to analyse the effect of an elastomer buffer implanted in the suspension of an automobile. In this study, the effect of coil spring with and without polyurethane buffer on spring damping capabilities will be analysed. In new vehicle, performance of the suspension is better, but after some years performance of the suspension is reducing. Which also impact on suspension life, so performance of the suspension will be increased by using urethane buffer

Evaluation of SARDAC Technique During En-Masse Retraction in Lingual Orthodontics

To evaluate the predictability of (SARDAC) technique regarding torque control and vertical movement during en-masse retraction in lingual orthodontics.Different setups of the SARDAC technique were tested during en-masse retraction in lingual orthodontics. Simulated retraction was performed using the Orthodontic Measurement and Simulation System (OMSS). Lever arms were welded between the lateral incisor and canine brackets bilaterally on a 0.017“X0.025” inch maxillary lingual stainless- steel wire. Bilateral, nickel titanium coil springs were used to apply a retraction force of 1.5 N per side on para-median mini-screws, inter radicular mini-screws and to the first molar brackets.Regarding the torque, the group where the force was applied between the 15 mm lever-arm and the first molar bracket, was the only group that showed statistically significant difference (palatal root torque) during en-masse retraction compared to the control group. Regarding the vertical movement, no statistically significant difference was found between any mechanical setup and the control group.SARDAC technique is predictable and efficient in controlling torque and vertical movement during en-masse retraction in lingual orthodontics.

Finite Element Study to Evaluate the Stress Around Mini-implant during Canine Retraction using Continuous and Interrupted Orthodontic Forces

Abstract:&#x0D; Objectives: This work aimed to determine the stress distribution around a mini-implant during dynamic canine retraction utilizing continuous and intermittent orthodontic forces and a three-dimensional finite element model.&#x0D; Materials and Methods: Establishing a three-dimensional finite element model of canine retraction. The model incorporates a mini-implant, alveolar bone, maxillary teeth, a closed coil spring, and an elastic chain. They were described as being homogeneous, isotropic, and linear elastic. Continuous and interrupted forces were approximated by a NiTi coil spring and an elastic chain, respectively. To retract the canine, a simulated orthodontic force of 1.5N, 2N, and 2.5N were loaded. ANSYS evaluated the value of the stress distribution around the mini-implant, canine, and bone interface (workbench 19).&#x0D; Results indicated that there was no significant difference between the values of maximum stress around the miniscrew, canine, and bone under different orthodontic loads when a closed coil spring and an elastic chain were evaluated.

In vitro study of the stretching time-associated force magnitude generated by NiTi and stainless-steel closed coil springs

Closed coil spring is an additional tool in a fixed-orthodontic treatment. NiTi is an orthodontic alloy that has shape memory and elasticity features, while stainless steel has properties of malleability, low friction between wire-bracket, as well as easy soldering and welding. Various properties of closed coil springs have been widely studied, but research on the stretching time remains unclear. This study aimed to determine the effect and differences in the stretching time for 7 days, 14 days, 21 days, and 28 days on the force magnitude of NiTi and stainless-steel (SS) closed coil spring. A 7 x 5 x 1 cm acrylic blocks with 1 cm acrylic posts were employed, and 25 mm closed coil springs were attached to the acrylic posts using modified T-sticks. The springs were immersed in an artificial saliva with pH of 6.75 for 7, 14, 21, and 28 days in an incubator at 37 °C. The container was removed from the incubator and the force was measured using a universal testing machine. Kolmogorov-Smirnoff test was carried out to analyze parametricdata, while independent T-test was used to determine the difference between each group. There was a significant effect of stretching time on the force magnitude of the SS closed coil spring in all the groups (p &lt; 0.05). There was no significant effect of stretching time on the force of the NiTi closed coil spring on days 7, 14, and 21 (p &gt; 0.05) but there was a significant effect on day 28 (p &lt; 0.05). A significant effect between the ratio of the SS and NiTi closed coil spring (p &lt; 0.05) was confirmed. Longer stretching time indicated a force loss in the SS closed-coil spring, while the NiTi spring had a more stable force which implies a formidable treatment-time for orthodontic treatment.

Spring Back the Lost Space: Fixed Space Regainer for E Space Loss- A Case Report

Maintenance of the E space is crucial to the normal development of dentition and early loss of second deciduous molars due to caries can compromise the same if not managed with a space maintainer. Fixed space regainers are being increasingly used to upright and distalisation of molars regaining the lost space and offering rapid results over their removable counterparts. Sectional orthodontics has been the focus of interceptive orthodontics in the recent past and the use of pre-adjusted edgewise appliances bonded to the erupted teeth and introduction of NiTi coil springs can help in rapid space regaining.

Analysis of the Material Properties of Vehicle Suspension Coil Spring

Analysis of the Material Properties of Vehicle Suspension Coil Spring