Rubber Cover Research Articles

Rubber plantations are impermeable to an avian understory specialist in Sri Lanka

BackgroundUnderstanding how landscape characteristics affect animal movement is essential for conservation in human-dominated habitats. A fundamental question is how monoculture agroforests, including rubber and tea plantations, affect wildlife and its movement. Experimental translocations represent an important technique to assess animals’ habitat selection while moving through agricultural matrices, especially when complemented with observations of birds’ natural movements, and with “control” translocations, in which birds are moved within their natural habitat such as forest. Yet, experimental translocations have been little used for birds outside the Western Hemisphere.MethodsWe conducted experimental translocations and home-range measurements on an understory forest specialist, Brown-capped Babbler (BCBA, Pellorneum fuscocapillus), and a forest generalist, Tickell’s Blue Flycatcher (TBFL, Cyornis tickelliae). These species were studied in three rubber plantations, which also included some open areas mostly planted with tea, and in three forest reserves of Sri Lanka.ResultsFour of the five BCBAs translocated within disturbed habitats (rubber plantations) could not return to their capture locations. However, all four individuals within undisturbed habitats (forest reserves) successfully returned to their point of origin within 10.5 daytime hours. In contrast, all TBFLs returned to their capture locations in both disturbed (n = 7) and undisturbed habitats (n = 3) within 11.3 daytime hours. A Cox-proportional survival model demonstrated that the percentage of rubber cover decreased return time, similar to the effect of open-area cover. The home range surveys (n = 13 for BCBA, n = 10 for TBFL) revealed that very little of the birds’ natural home-ranges was covered by rubber (0.2% for BCBA, 13.1% for TBFL at 50% Kernel Density Estimates KDE). Home range size for BCBA was approximately half the size in disturbed habitats compared to undisturbed ones, although there was no significant difference between habitats for TBFL.ConclusionsWe conclude that rubber plantations can be impermeable to understory habitat specialist birds, and even generalist species may avoid them long-term. Our findings highlight the potential utility of strips of native vegetation, particularly those featuring understory layers, as corridors to facilitate the movement of forest specialists in landscapes dominated by rubber plantations and other types of disturbed habitats.

Performance Evaluation of a Nylon-like Polyester Tire Cord Combining the Characteristics of Nylon and Polyester.

A nylon-like polyester tire cord, which combined the characteristics of nylon and polyester tire cords, was designed as the carcass reinforcement material used to meet the increasing demands of the tire industry for performance and impact on the environment. Tires' carcass construction plays a crucial role in affecting handling performance and ride comfort. Small changes in the carcass component can lead to significant improvements in the total tire/vehicle performance. This study evaluated the performance of nylon-like polyester and nylon 6 motorcycle tires. The results showed that the nylon-like polyester tire passed all indoor tests, and post-cure inflation (PCI) could be eliminated, resulting in energy and cost savings. The rolling resistance coefficient of the nylon-like polyester tire was reduced by 6.8% compared to that of the nylon 6 control tire, which could save fuel and have a positive impact on the environment. Nylon-like polyester tire cord extracted from the experimental tire possessed a higher modulus compared to that of nylon 6 tire cord, which could lead to better handling and ride comfort performance. Morphological pictures showed that both nylon-like polyester and nylon 6 cords extracted from tires had a good rubber coverage and comparable adhesion properties.

Soil Health of Rubber Plantations in Southern Côte D'ivoire: The Case of Cnra Anguédédou Rubber Plantations

The rubber tree, a species of Amazonian forest tree, is cultivated for its natural rubber-rich latex. Its cultivation is of economic, social, climatic and environmental importance. However, it has been criticized as a soil-destroying crop. To clear up this ambiguity, a study was launched to assess the health of soils under rubber cover in southern Côte d'Ivoire. The methodology involved selecting rubber plantations of [1 to 5 years], [6 to 10 years], [11 to 20] and [20-40 years], and two (02) 42-year-old rubber tree plantations, abandoned for 8 years, were compared to those of a forest. In these biotopes, soil samples were taken using an auger and a metal cylinder, then analyzed in the laboratory to determine soil fertility and ecological parameters. The results showed that the saturated soils of young plantations aged 6 to 10 years are poor in organic matter and cation exchange capacity, mainly calcium and magnesium. However, organic carbon stocks are high in abandoned plantations (182.38 mg/ha) and plantations over 20 years old (164.5 mg/ha). The assessed deterioration index reveals that soils in young plantations aged 6 to 10 years are degraded, with an SDI = -40%. These soils recovered as the plantations aged, with a SDI of 151% in abandoned plantations.

The Role of Reduced Graphene Oxide in Enhancing the Mechanical and Thermal Properties of a Rubber Cover Joint.

The development of high-performance rubber composites has always been a research hotspot in the field of conveyor belt manufacturing. In this work, a rubber cover joint composite made of reduced graphene oxide (rGO) was prepared using latex mixing and mechanical blending methods, with a steel wire rope conveyor belt as the research object, and the influence of the rGO content on the properties of the rubber composite is discussed. The structure and morphology characterization of the rGO/NR rubber show that the addition of rGO does not change its crystal structure, and 1.2 phr rGO is uniformly dispersed throughout the rubber composite. As more rGO is added, the mechanical properties of the rGO rubber cover joint first improve and then worsen. With the addition of 1.2 phr, the cross-linking density increases by 80.6%, the tensile strength of the rubber composites increases by 49.7%, the elongation at break increases by 23.6%, and the adhesion strength increases by 12.4%. The tensile strength of the rGO rubber cover joint can still maintain 72.5% of its pre-thermal aging value. The wear resistance and thermal conductivity increase as more phr is added. When 3.0 phr is added, the wear resistance of the rubber composites increases by 32.9%, the thermal conductivity increases by 118.8%, and the temperature difference at the completion of vulcanization decreases from 4.5 °C to 1.8 °C. The results show that when 1.2 phr of rGO is added, the rubber conveyor belt joint obtains the best comprehensive performance. These enhanced comprehensive properties allow for the practical application of rGO nanomaterials to conveyor belt rubber.

Economic impact of investment in animal welfare–enhancing flooring solutions – Implications for promoting sustainable dairy production in Sweden

PurposeThe purpose of this paper was to assess the economic impact of investment in different animal welfare–enhancing flooring solutions in Swedish dairy farming.Design/methodology/approachThe authors developed a bio-economic model and used stochastic partial budgeting approach to simulate the economic consequences of enhancing solid and slatted concrete floors with soft rubber covering.FindingsThe findings highlight that keeping herds on solid and slatted concrete floor surfaces with soft rubber coverings is a profitable solution, compared with keeping herds on solid and slatted concrete floors without a soft covering. The profit per cow when kept on a solid concrete floor with soft rubber covering increased by 13%–16% depending on the breed. Practical implicationsPromoting farm investments such as improvement in flooring solution, which have both economic and animal welfare incentives, is a potential way of promoting sustainable dairy production. Farmers may make investments in improved floors, resulting in enhanced animal welfare and economic outcomes necessary for sustaining dairy production.Originality/valueThis literature review indicated that the economic impact of investment in specific types of floor improvement solutions, investment costs and financial outcomes have received little attention. This study provides insights needed for a more informed decision-making process when selecting optimal flooring solutions for new and renovated barns that improve both animal welfare and ease the burden on farmers and public financial support.

A lightweight waterborne acoustic meta-absorber with low characteristic impedance rods

We investigate a meta-absorber composed of impedance-matched rods for the broadband acoustic absorption. However, with a slow longitudinal wave speed, the absorber’s density is high to keep the characteristic impedance matching with that of water. To obtain a lightweight high efficiency absorber, we analyze the influence of characteristic impedance and loss factor on absorption behaviors and find that the characteristic impedance matching is not necessary and the low characteristic impedance structure can also attain the efficient absorption performance, and the high dissipation can reduce the density required for an efficient absorption. Based on this, we propose a meta-absorber composed of low characteristic impedance rubber rods in parallel coated by a rubber cover layer and backed with a stepped resin base. By the combination of the transfer matrix method and transmission line impedance transfer equation, the acoustic performance of meta-absorber is analyzed. Compared with the characteristic impedance matching rods, the low characteristic impedance rods can release restrictions on design to attain better acoustic behaviors with a lower density. Further, the integration of rods with designed lengths can motivate coherently coupled weak resonances to obtain a broadband absorption. Finally, an optimized meta-absorber is tested in a water-filled impedance tube and the experimental results agree well with the theoretical results which can achieve a broadband low frequency quasi-perfect absorption (α>0.9) in a deep subwavelength region (λ/158 at 950 Hz) with the density close to that of water. Our work finds a new mechanism that low characteristic impedance absorbing materials can achieve the high efficiency absorption with a slow longitudinal wave speed and low density and promise broad applications in the sound stealth of marine vehicles.

Effects of Perching on Poultry Welfare and Production: A Review

Perching is one of the essential natural behaviors for avian species. Providing an optimal perching design (e.g., shape, dimension, and materials) for commercial poultry production is critical for maintaining bird health, welfare, and production efficiency. This review paper summarized poultry perching studies and discussed the relationship between perch design, bird welfare, and production efficiency. Providing perches at an early stage may ensure optimum use during adulthood, reduce perching accidents, and lower the risk of floor eggs in cage-free (CF) hen houses. Therefore, a perch space of 15 cm per bird is recommended for the CF hen house. Similarly, rectangular perches are preferred to circular perches as the rectangular perch provides hens with an excellent tendon-locking mechanism to prevent slipping. In addition, perches with softer materials such as polyurethane and rubber coverings are recommended to increase the contact surface on the chicken’s toes. Perching behavior (PB) promotes a musculocutaneous system and reduces the incidences of footpad dermatitis and lesions. Generally, providing perching may reduce aggression and stress in birds and improve welfare and production efficiency. In the case of broilers, it is found that the broiler perches less during the latter stage of their lives because they are comparatively heavier and exhibit a more inactive lifestyle. Studies have investigated the effect of the surface temperature of the perch on broilers’ welfare. Perches with lower temperatures help improve performance and welfare by relieving heat stress and leg issues. Overall, PB is required to improve bird health and welfare.

The Synthetic Rubber Cover for Applicator Roll

The Synthetic Rubber Cover for Applicator Roll

Resin cement around tissue and bone level dental implants after two cementation techniques (an in vitro study)

Purpose: To detect the retained excess resin cement around tissue and bone level dental implants following two different cementation techniques. Methods: Fourteen tissue level and fourteen bone level implants (OCO Biomedical, U.S.A.) were embedded in models (Salvin Dental Specialties, U.S.A.) having rubber surface simulating the gingiva. Twenty-eight metal copings were fabricated and cemented to the implant’s abutments by RelyX U200 resin cement (3M, U.S.A.). Each group was subdivided according to the cementation technique into two subgroups: A1 and B1: Tack cure of the excess cement for three seconds, the partially set resin cement was carefully removed before complete cure. A2 and B2: 1mm vent was performed on the occlusal surfaces. Excess cement was carefully removed followed by a final cure. Rubber coverage was removed, retained cement net weight was determined. All specimens were visually examined under 30x magnification using Stereomicroscope (SZ-11, Japan). Results: Tissue level implants following the tack cure protocol had less retained excess cement percentage than the occlusal vent protocol. Statistical comparison showed a significant difference in the excess cement percentage within the tissue level subgroups (p=0.018), No significant difference observed within the bone level subgroups (p=0.096).

Resin cement around tissue and bone level dental implants after two cementation techniques (An In Vitro Study)

Purpose: To detect the retained excess resin cement around tissue and bone level dental implants following two different cementation techniques. Methods: Fourteen tissue level and fourteen bone level implants (OCO Biomedical, U.S.A.) were embedded in models (Salvin Dental Specialties, U.S.A.) having rubber surface simulating the gingiva. Twenty-eight metal copings were fabricated and cemented to the implant’s abutments by RelyX U200 resin cement (3M, U.S.A.). Each group was subdivided according to the cementation technique into two subgroups: A1 and B1: Tack cure of the excess cement for three seconds, the partially set resin cement was carefully removed before complete cure. A2 and B2: 1mm vent was performed on the occlusal surfaces. Excess cement was carefully removed followed by a final cure. Rubber coverage was removed, retained cement net weight was determined. All specimens were visually examined under 30x magnification using Stereomicroscope (SZ-11, Japan). Results: Tissue level implants following the tack cure protocol had less retained excess cement percentage than the occlusal vent protocol. Statistical comparison showed a significant difference in the excess cement percentage within the tissue level subgroups (p=0.018), No significant difference observed within the bone level subgroups (p=0.096). 

Abrasiveness of iron ores: Analysis of service-worn conveyor belts and laboratory Dry Sand/Rubber Wheel tests

Belt conveyors are currently one of the most commonly used technologies for transporting iron ore. Of the components of the conveyor system, the belt is the most expensive and susceptible to damage. Failures due to wear of the rubber cover lead to downtime for corrective maintenance, greater operational risks and performance and economic losses. To improve the tribological performance of conveyor belts, it is necessary to know the main parameters that influence their wear. As wear behavior is not an intrinsic property of a material, the most reliable results are obtained when the wear mechanisms produced in laboratory tests are similar to those in service. In this work, two types were investigated of belt rubber, one new and one worn in service, and four types of iron ore in two class sizes. Loose abrasive wear tests were carried out using the Dry Sand/Rubber Wheel apparatus with belt rubber test pieces and iron ores as abrasives. This work characterized the wear mechanisms that occur in service and in laboratory tests. The predominant wear mechanism found was the formation of Schallamach waves. In the wear tests, Friable Hematite samples presented the highest abrasiveness. In addition, the chemical, mineralogical and morphological features of the iron ore samples were characterized. The high abrasiveness of Friable Hematite was possibly due to the mineral assembly.

IDENTIFIKASI SURFACE RUBBER COVER UNIT INSERT MACHINE BILLING STATEMENT UNTUK MEMINIMALISIR LAJU KEGAGALAN

A rubber cover flyerroll on an insert machine that has been operating for 3600 hours and is damaged, so an analysis is needed to determine the cause of the damage and a process to overcome the damage and the same failure occurs in the future. This flyer roll functions as a billing statement folder before being inserted into an envelope with dimensions of 28 mm (OD) x 284 mm (L). To find out the cause of the damage, several tests were carried out, namely destructive testing and chemical composition testing. Physical tests carried out include hardness test, tensile strength test, modulus test, elongation break test, density test, and abrasion resistance test. resistance test) and in this study a chemical composition test was conducted. From the test results, it can be seen that the hardness value is still within the tolerance limit, which is 94 shore A with a tensile strength value of 31.7 N/mm2 and the results of the chemical composition are dominated by polyurethane rubber at 62.9% and polystar at 23%. So from the tests that have been carried out, it can be concluded that the cause of the damage that occurs to the rubber cover flyer roll is caused by improper maintenance methods, machine maintenance that is not carried out and standard operational procedures (SOPs) that are not carried out according to the recommended maintenance process

Effect of urea in steamed sago waste on rumen fermentation parameters in vitro tested

This study aims to determine urea’s effect in steamed sago waste on rumen fermentation parameters in vitro testing. Sago waste was dried for two days, discarded fibre sticks, steamed for 30 minutes, cooled and dried. Weighed 250 g of steamed sago waste, added urea with levels of 0%, 2%, 4% and 6%. Weighed 0.5 g of samples per treatments, inserted in fermentor tubes, added 10 ml buffer and 10 ml of rumen fluid (1:1). Fermentor tubes are inserted in waterbath with a temperature of 39°C, flowed with CO2 gas and covered with a valved rubber cover. For NH3 and VFA testing, incubation was carried out for 4 hours, while for DMD and OMD testing, incubation was carried out for 48 hours. The data obtained were analyzed using a completely random design with four urea level treatments (0%, 2%, 4%, 6%), with five replications. The results showed that increase of urea level up to 6%, increasing (P<0.01) NH3. The increase of urea level 2%, increasing (P<0.01) VFA, DMD and OMD. The increase of urea levels 4% and 6%, not significant effect on DMD and OMD, while at urea level 6%, decreasing (P<0.01) VFA. It can be concluded that urea was added in steamed sago waste, have an optimal effect on the rumen fermentation parameters at level 2–4%.

Theoretical and Experimental Investigation of Bonded Patch Repairs of a Rubber Reinforced Composite Conveyor Belt.

The present study proposes a reparation method for designing and optimizing a rubber to rubber and rubber to textile reinforcement. The present application is the conveyor belt used in the transport industry. The tensile behavior of the repaired specimens was studied using experimental results. A bidirectional linear analysis allows us to predict the effect of geometric parameters on the stress concentration zone of the repaired belt under hygro-thermo mechanical loading and its consequence on the integrity of the structure. A tensile test was carried out in order to investigate the behavior of a repaired specimen made with a rubber cover patch and an inner composite patch. Two stacking sequences of an inner composite patch and the material properties are considered in the parametric study in order to reduce the stress concentration in the parent belt. The correlation between the theoretical and experimental results allows us to define a strength tool to understand the load transfer from rubber to a textile rubber patch.

Table Tennis: Effect of Humidity on Racket Rubber Tribology

In contrast to a flourishing development of racket rubber coverings, or rubbers, no technical data can be found on their performance under different environmental conditions. In light of this, here we report an experimental study on the frictional response of four different popular rubbers, with pimples-in and pimples-out gometry, tested against three different balls at five levels of relative humidity. It is found that the humidity does affect the frictional characteristics of the rubbers, with all parameters being responsive to changes in the environmental conditions and reaching maximum at the humidity of about 45–60% in a majority of the cases. Probably the most interesting finding is that the ball surface finish has significant effect on the frictional response of all rubbers. This can provide players with the ability to affect the rubber performance at different levels of humidity by simply choosing between different balls.

Impact of adhesive ingredients on adhesion between rubber and brass‐plated steel wire in tire

AbstractProficiency on underlying mechanism of rubber‐metal adhesion has been increased significantly in the last few decades. Researchers have investigated the effect of various ingredients, such as hexamethoxymethyl melamine, resorcinol, cobalt stearate, and silica, on rubber‐metal interface. The role of each ingredient on rubber‐metal interfacial adhesion is still a subject of scrutiny. In this article, a typical belt skim compound of truck radial tire is selected and the effect of each adhesive ingredient on adhesion strength is explored. Out of these ingredients, the effect of cobalt stearate is found noteworthy. It has improved adhesion strength by 12% (without aging) and by 11% (humid‐aged), respectively, over control compound. For detailed understanding of the effect of cobalt stearate on adhesion, scanning electron microscopy and energy dispersive spectroscopy are utilized to ascertain the rubber coverage and distribution of elements. X‐ray photoelectron spectroscopy results helped us to understand the impact of CuXS layer depth on rubber‐metal adhesion. The depth profile of the CuXS layer was found to be one of the dominant factors of rubber‐metal adhesion retention. Thus, this study has made an attempt to find the impact of different adhesive ingredients on the formation of CuXS layer depth at rubber‐metal interface and establish a correlation with adhesion strength simultaneously.

Mechanical behavior of lead rubber bearings under and after nonproportional plane loading

SummaryLead rubber bearings, which have been extensively applied in many seismic isolation designs for buildings, infrastructures, and facilities worldwide, were tested under unilateral reversal loading as well as nonproportional plane loading including circular, figure‐eight, and square orbits in this study. The test results indicate that unlike the unilateral hysteretic behavior, the bilateral one of lead rubber bearings is too complicated to be characterized adequately by a simplified bilinear hysteretic model. It is mainly attributed to the bilateral coupling effect, which can be clearly observed from the abnormal deformation of the mesh pattern drawn on the rubber cover during the tests. In addition, after being subjected to nonproportional plane loading, the tested bearings reveal visible permanent twisting deformation. The profiles of the cut bearings present the fracture of the inside lead plugs. Even so, the further unilateral reversal loading test results prove that the fracture might not affect the whole hysteretic behavior and mechanical properties very much. The applicability, robustness, and generalization of adopting three previously developed analytical models for describing the coupled bilateral hysteretic behavior of lead rubber bearings are further demonstrated by comparing their predictions with the nonproportional plane loading test results. Although the coefficients are identified from unilateral reversal loading tests, the three analytical models can still have an acceptable prediction capability.

Simulation the Effect of impact on the Mobile Cover Using Solidworks Anal

Mobile phones are complex and sensitive electronic devices that may be susceptible to fracture if fell down unless shielded securely.Accordingly, Cases are effective means to defend the phones against sudden impact. The performance of these covers relay on many aspects such as design and the potential of the materials. For this reason, it is intended in this project to estimate the effect of the material properties on the impact resistance of the covers using the powerful of Solidworks program. The materials modeled linear elastically and the mobile impacted the ground from a 1 m height under the effect of gravitational force. The results showed that mobile cover made of silicone rubber failed in the impact and polycarbonate shelter was superior to thermoplastic polyurethane rubber cover due to the highest modulus of elasticity. In addition to that, verification of the simulation process was done by comparing the results to the experimental works cited in the literature. It is found that maximum Von Mises stress at the bottom edge and the corners of Gorilla Glass were satisfactory close to the result obtained by Bocko et al.

RETAINED EXCESS RESIN CEMENT AROUND TISSUE LEVEL IMPLANTS USING TWO DIFFERENT CEMENTATION TECHNIQUES (AN IN VITRO STUDY)

INTRODUCTION: The main disadvantage of a resin cement-retained implant fixed prosthesis is the entrapment of residual excess cement in the peri-implant tissues. Remaining cement has been shown to be associated with peri-implant inflammation and bleeding. OBJECTIVES: The aim of this study was to detect the retained excess resin cement around tissue level dental implants, and to determine which method of cementation will show less amount of retained excess cement. MATERIALS AND METHODS: Fourteen tissue level implants (OCO Biomedical, Inc. Albuquerque, U.S.A.) were embedded in drilling models (Salvin Dental Specialties, Inc. Charlotte, U.S.A.) having rubber surface covering simulating the gingiva. Fourteen metal copings were fabricated (Realloy e.k, Sliemsdyk 50, Krefeld, Germany). RelyX U200 (TM3M, ESPE Dental Products. St. Paul, U.S.A.) dual cure resin cement was used for cementation of the metal copings to the implants. The implants were divided into two main groups according to cementation technique (n=7): Group (A): non vented tack curing of the excess cement for three seconds then the excess resin cement was carefully removed. Group (B): occlusal vent was performed on the occlusal surface of the metal copings to allow excess cement to be extruded through the vent hole; then all the excess cement from the vent and margins was removed. The rubber coverage was removed and the retained cement was collected and the net weight of the retained cement was determined. RESULTS: Mann-Whitney U test revealed a statistically significant differences (p < 0.05) between the non-vented tack cure and the occlusal vent groups in the amount of retained excess cement, with the occlusal vent group (B) had more excess cement percentage than the non vented tack cure group (A). CONCLUSIONS: Tack curing of the excess resin cement during the cementation of implant-supported restorations might reduce the cement residue, but still couldn’t remove the problem of excess resin cement around dental implants.

Identification and harmfulness analysis of solid particles contained in medical injections and their removal by nuclear track membranes

Summary Two types of cascade nuclear track filters have been developed: (1) cascade filter made of polypropylene (PP) fiber membrane as preliminary filter and nuclear track membrane (NTM) as terminal filter; (2) Nylon tortuous-pore membrane as preliminary filter and NTM as terminal filter. Removal of solid particles by the cascade filters has been investigated. The solid particles studied include glass shards from broken ampoules and rubber fragments from rubber covers (plugs) of medical bottles. When an ampoule containing medicine is broken by emery wheel and by hands, large number of glass shards are produced and fall into the medicine. When a rubber cover is punctured by syringe needle, large number of rubber fragments are produced by friction between rubber and needle. The investigation shows that fiber or tortuous membranes alone usually cannot completely remove the microscopic particles due to existence of large gaps in the structure of the two common membranes. Nuclear track membranes alone and their cascade filters are superior to remove all solid particles bigger than the pore size of the track membrane. Removal efficiency for solid particles and flow rate of injections through the cascade filters have been calibrated and shown that both features above fulfill the requirements of Chinese regulations. The two types of cascade filters have been accepted for use in Chinese hospitals.