Degradation Analysis of Jute Fiber Reinforced Waste Tile Powder-Filled Polymer Composite on Wear Characteristics

In this study, a polymer composite is made using chemically treated jute fiber and waste floor tile powder as an alternative source for roof tile application. The wear qualities were examined at various ages, and the outcomes were optimized. In order to improve the wetting properties of the jute fiber, it was chemically treated. MINITAB software was used to develop Taguchi method parameters such as jute fiber percentage, waste tile powder percentage, and NaOH chemical treatment using the MINITAB software. It was determined that hardness was the most important characteristic in terms of wear properties after the specimens were subjected to ageing and abrasion wear testing and hardness tests were carried out as per normal protocols. As a result of the waste tile powder addition, the surface and core pore formation rates were reduced and the wear index rates were low. Jute fiber with 15%, 9% tile powder, and 5% NaOH treatment were found to have the lowest wear index of the other specimen compositions tested, according to the wear index. Specimen made with 5% jute fiber addition, 9% tile powder inclusion, and 10% NaOH treatment, on the other hand, had more hardness. Degradation of the fibers and delamination are side effects of the ageing process. The wear resistance of the surface was increased by the use of waste tile powder.

Influence of Wheel Profile Wear Coupled with Wheel Diameter Difference on the Dynamic Performance of Subway Vehicles

In view of the coexistence of wheel profile wear (WPW) and wheel diameter difference (WDD) on an actual subway line, a dynamic analysis method based on coupling between WPW and equivalent in-phase WDD was proposed. Based on the measurements from a subway vehicle in operation on this line, dynamics modeling and calculations were performed for a single carriage of this vehicle. Later, the interaction between the effects of WPW and equivalent in-phase WDD on the vehicle dynamic performance was analyzed, and the dynamic response in the presence of coupled damage was compared between the outer and inner wheels. Furthermore, the difference in the dynamic response caused by different positions of the larger-diameter wheels (i.e., on the inner track or outer track) was analyzed for the case where equivalent in-phase WDD occurred between the front and rear bogies. The results show that when the vehicle ran on a straight line, the coupling between WPW and WDD reduced the vehicle’s stability but improved its ride comfort. When the vehicle traveled on a curved line, it showed reductions in the lateral wheel/rail contact force, derailment coefficient, axle lateral force, and wear index if the outer wheels had a larger diameter. As a result, the deterioration of the vehicle’s dynamic performance due to the increasing degree of WPW slowed down, and its curve negotiation performance improved. Meanwhile, the outer wheels had significantly greater lateral wheel/rail contact force, derailment coefficient, and wear index compared to the inner wheels. When a −1 mm WDD was coupled with the worn wheel profile for 14 × 104 kilometers traveled, the dynamic performance indexes of the vehicle were close to or even exceeded the corresponding safety limits. The findings can provide technical support for subway vehicle maintenance.

A Comparison of Etiology-Derived and Non-Etiology-Derived Indices Utilizing for Erosive Tooth Wear in People with Eating Disorders. The Validation of Economic Value in Clinical Settings

Increasing occurrence of non-carious lesions in their various forms and etiologies requires reliable and valid diagnostic tools to register their distribution, severity, and progression and to become helpful in planning treatment. The aim of this work is to evaluate eight selected (etiological and non-etiological) indices of tooth wear/erosion, taking into account the subjective opinion of the researcher/operator and the patients being treated for eating disorders. The research sample included 60 people with symptoms of dental erosion. The study group included 30 patients suffering from eating disorders, recruited from three independent medical institutions providing eating disorder therapy. The control group consisted of 30 patients with no eating disorders, but with dental erosion caused mostly by a low-pH diet. The indices chosen for evaluation were: Tooth Wear Index by Smith and Knight; indexes by Lussi, Johansson et al.; Tooth Wear Index modified by de Carvahlo Sales-Peres et al.; Linkosalo and Markkanen modified by Ganss et al.; and index Oilo et al., BEWE, VEDE. The examination took place during three short visits. The study group (suffering eating disorders) and the control group (without eating disorders) evaluated the indices chosen for this research similarly. In the assessment made by both groups of patients, the usefulness and application benefits of the etiological indices set were not significantly different than in the case of a set of non-etiological indexes. An analogous opinion has been made by the operator/researcher as far, as the following aspects are concerned: the number of indexes criteria, order of difficulty in memorizing criteria and in the procedure of indexes application. According to this research, for the group at risk of dental erosive wear (with or without eating disorders), optimal research tools to evaluate dental wear occurred: index by Lussi, Tooth Wear Index modified by de Carvahlo Sales-Peres et al., BEWE, index by Oilo et al.

An Analysis of Electronic Primary Dental Practice Tooth Wear Referrals

We evaluated the quality of general dental practitioner (GDP) tooth wear (TW) referrals to secondary care services in Kent, Surrey and Sussex. Prospective consecutive referrals received via an electronic pathway were assessed from 1 June to 30 October 2019. Reasons for referral, patient demographics, quality of referral, opinion of the triaging clinician and outcome were assessed. Of 671 referrals, 32% were for TW. Males were referred more commonly (1.7:1.0). The median age was 52. Patients were more likely to be referred from distant locations than places closer to the referral centre (p<0.001). Only 55% of referrals suggested a cause for the TW, 33% provided a clinical photograph and 1% recorded a tooth wear index of any type. Referring clinicians most commonly cited attrition as reason for referral (p<0.001). Those under 40 years were referred for erosion (p=0.001) and those over 40 years, attrition (p=0.019). The triaging clinician was more likely to allocate a tooth wear score of three for those under 40 years and a score of four for over 40 years (p<0.001). 47% of referrals were rejected. Males and referrals with photographs were more likely to be accepted for treatment (p=0.017 and p<0.001, respectively). There is a high demand for specialist TW services. The number of referrals being rejected has not changed using the electronic referral system. We advocate the inclusion of mandatory fields for completion by GDPs as well as compulsory clinical photographs and tooth wear indices (Smith and Knight Tooth Wear Index or a basic erosive wear examination - BEWE index).

Wear Comparison of a Plain Toothbrush versus Eleven Commercial Toothbrushes

Objective: To compare the wear of the Sound Feelings SOFT Plain Toothbrush 47 tuft (flat bristles) versus eleven manual toothbrushes. Methods: Twelve brand-new manual toothbrushes (n = 35 in each group) were used for comparison. Each toothbrush was run on a toothbrushing simulator with a brushing force of 2N for approximately 2 hours to simulate 1 month of toothbrushing (9,333 strokes @ 45° lingual of posterior teeth, 9,333 strokes on the top surface, and 9,333 strokes @ 45° buccal of posterior teeth), using the Bass technique on a quadrant typodont. Wear was measured by wear index and wear rating. The Wear index measures the degree of bristle splaying whereby the bristles spread apart and take on a permanent curvature. Wear rating is a subjective rating scale consisting of a series of four numbers increasing from zero to three. The Olympus SZX16 microscope was used to measure the wear rating then was inputted into a formula and averaged. The subjective wear seen as bristle splay/ curling was also measured and recorded. Comparison of the wear index and wear rating between each manual toothbrush was conducted using the Mann-Whitney test. Results: Wear index and wear rating for all toothbrushes ranged from 0.03 to 0.34 and from 0.57 to 2.06, respectively. There was a significant difference in the wear index between each toothbrush and the Sound Feelings SOFT Plain toothbrush. The difference in the wear rating was significant between the Sound Feelings SOFT Plain toothbrush and all other toothbrushes other than the Reach Advanced Design Soft toothbrush. Conclusion: The Sound Feelings SOFT Plain Toothbrush had the lowest wear rating and index among all the manual toothbrushes tested.

The Study and Analysis of Sinter Ores` Fragmentation Situation after Times Continued Drum Test

The article concludes the drum index and wear index of sinter ores by times continued drum test. Based on the test results, we analysis the fragmentation situation of sinter ores and the principle which effects the grade distribution under drum test. The results show that after drum test, the quality of sinter ores between 0.00-5.00mm and 10.00-16.00mm rises apparently, while other part all get lower. What`s more, when the times of drum test are same, the powdery degree will get bigger if the time is longer. When the time of drum test is same, the powdery degree will get bigger if the times are more. When the times and times are all the same, the powdery degree will be closely, which shows the results fits the Experimental errors.

Evaluation of the cutting insert condition influence on the microstructure of surface layer after turning of Inconel 718 alloy

Research concerns the evaluation of the cutting insert condition on the microstructure of the surface layer after longitudinal turning of Inconel 718 alloy using carbide inserts. Value of the VBC wear index after dry machining with variable feed f and depth of cut ap was evaluated. White layer was observed up to 2,5 μm.

A Friction–Wear Correlation for Four-Ball Extreme Pressure Lubrication

A first-ever friction–wear model for four-ball extreme pressure (EP) lubrication is developed in this work based on 12 oil samples comprising minerals, esters, and other formulated lubricants. The model considers the rate of entropy generation and dissipation within the lubricated tribosystem to describe the interaction between the friction and the wear behaviors at extreme pressure conditions. The model can be used to calculate the probability to pass or fail at a specific load to estimate the weld point of a lubricant. The calculated probability exhibited a similar trend as a load-wear index from the ASTM D2783 EP test method. Besides, the model is able to estimate the EP performance of an unknown lubricant based on the model parameter, namely the dissipative coefficient. This parameter describes the proportionality between the friction and the wear phenomena from the perspective of thermodynamic analysis. This work provides useful tools to better understand the fundamentals of EP lubrication and to characterize the lubricants without overly relying on tribotest machines.