Effect Of Polyethylene Research Articles

Effect of Polyethylene on Fruit Yield and Morpho-Biochemical Features During Ripening of a Local Tomato Cultivar Grown in a Tropical Environmental Condition, India

The work was assessed the field performance of Polythene cover on morphology, fruit yield and post maturation changes on growing tomato (Lycopersicon esculentum). Data revealed that use of polythene gave adverse effect on average height in treated condition but favourable for matured ripen fruits (41.5%). Significant correlation observed in the post maturation (0.731, P≤0.01) and fruits ripening time (0.605, P≤0.01). The fruit yield was found to be significantly increased by 61.23%. Polythene induced ripening had shown the variation in the amount of lycopene (429.3mg/100gm), protein (1.92%), ascorbic acid (23.68 mg/ 100gm) and the sugar (5.02%). Polythene covering was significant and positively correlated with lycopene (0.788, P<0.01), lipid(0.853, P<0.01),ascorbic acid(0.515 P<0.01) but negatively correlated with protein(-0.221P<0.05).Maturity at harvest is a very important attribute to tomatoes quality that found to be regulated by the use of polythene. Analysis of variance also showed statistically significant result in the lipid (F-value=14.688801,p≤0.01) ,sugar(F value= 25.52718,p≤0.01) and ascorbic acid (F-value=9.44343,p≤0.01).

The effect of polyethylene on the properties of talc-filled recycled polypropylene

ABSTRACT The reinforcement of recycled polypropylene (rPP) with mineral fillers, to obtain modulus values of 3000–4000 MPa has proven challenging for recyclers, whereas this is common practice for virgin PP. The main difference between recycled and virgin PP is the contaminating presence of other polymers. In this study, the composition of rPP sourced from electrical and electronic waste was analytically estimated. The rPP was found to be a PP/HDPE blend with ca. 90/10 m% ratio. Furthermore, the effect of HDPE on the thermal and physical properties of talc-filled PP was investigated by means of re-engineered blends and talc-filled compounds. It was found that HDPE has a profound effect on the degree to which rPP can be reinforced by talc. However, the quantified effects of the HDPE alone were not of sufficient magnitude to account for the full difference in properties between talc-filled rPP and virgin PP.

Effect of Polyethylene and Butylated Hydroxytoluene on the histological structure and some enzymes of rat liver

Effect of Polyethylene and Butylated Hydroxytoluene on the histological structure and some enzymes of rat liver

Experimental and numerical study on smoke evolution in polyethylene (PE) slabs enclosed compartment fire

ABSTRACT Full-scale compartment fire experiment initiated by a corner gasoline pool fire was conducted to investigate the enhancement effect of polyethylene (PE) slabs attached on the internal walls on fire development and smoke evolution. An open door and an initially closed window served as the openings to provide natural ventilation condition. Corresponding numerical simulations, employing a CFD tool Fire Dynamics Simulation (FDS), were carried out as well to study the fire growth, smoke temperature, smoke layer height, and indoor visibility. Both PE and non-PE compartment fire circumstances were simulated to examine the intensifying mechanism of burning PE slabs. The results show that the attached PE slabs on the walls would greatly intensify the compartment fire and result in a much higher smoke temperature by about 325 °C, which could significantly facilitate the potential occurrence of flashover. The molten PE generated a considerable pool fire on the floor and resulted in a secondary peak in smoke temperature curve after the burnout of gasoline. However, this secondary peak is not found in the simulation results due to the neglect of melting and flowing process in numerical model. Some random ignition incidents in test, such as the splash of pool fire and collapse of furniture, contributed to the deviation between experimental and numerical results. Smoke layer height was empirically estimated to be 1.8 m and compared with numerical predictions. The empirical model predicted the smoke layer height well after the break of window at the steady state.

Pengaruh Polyethylene Fiber pada Material Resin Komposit Terhadap Jumlah Koloni Streptococcus mutans

Fiber reinforced composite (FRC) is a material made of polymer matrix and fiber. Polyethylene fiber is one of the commonly used fiber due its good strength. FRC in the oral cavity will interact with saliva and microorganisms.S. mutans is microorganisms present in oral cavity. The purpose of this study was to determine the effect ofpolyethylene fiber on FRC to S. mutans colony counts. Flowable composite and polyethylene fiber are material used in this study. Bar-shaped samples sized 5 x 4 x 2 mm (n = 4) immersed in 5 mL saliva for 1 hour, then immersed in suspension containing S. mutans and incubated for 24 hours at 37°C. The suspension diluted to 10 then 0.1 mL of the dilution were put in a solid medium and incubated for 48 hours at 37°C. Streptococcus mutans were grown on solid media was determined by direct count. Data were statistically analyzed using unpaired t-test. The results of unpaired t-test showed a significance difference of S. mutans colony between composite resin and FRC with polyethylene fiber (p <0.05). The conclusion from this study was the addition of polyethylene fiber on the composite material significantly increased the number of colonies of Streptococcus mutans.

Mullins effect in polyethylene and its dependency on crystal content: A network alteration model

This contribution is focused on the Mullins effect in polyethylene. An ultra-low-density polyethylene with 0.15 crystal content, a low-density polyethylene with 0.3 crystal content and a high-density polyethylene with 0.72 crystal content are subjected to cyclic stretching over a large strain range. Experimental observations are first reported to examine how the crystal content influences the Mullins effect in polyethylene. It is found that the cyclic stretching is characterized by a stress-softening, a hysteresis and a residual strain, whose amounts depends on the crystal content and the applied strain. A unified viscohyperelastic-viscoelastic-viscoplastic constitutive model is proposed to capture the polyethylene response over a large strain range and its crystal-dependency. The macro-scale polyethylene response is decomposed into two physically distinct sources, a viscoelastic-viscoplastic intermolecular part and a viscohyperelastic network part. The local inelastic deformations of the rubbery amorphous and crystalline phases are considered by means of a micromechanical treatment using the volume fraction concept. Experimentally-based material kinetics are designed by considering the Mullins effect crystal-dependency and are introduced into the constitutive equations to capture the experimental observations. It is shown that the model is able to accurately reproduce the Mullins effect in polyethylene over a large strain range. The inherent deformation mechanisms are finally presented guided by the proposed constitutive model.

Analysis of Mullins effect in polyethylene using ultrasonic guided waves

Abstarct Small strain deformations below yielding can cause plastic deformation in semicrystalline polymers by a process similar to what is described for filled rubber-like materials known as the Mullins effect. Inter-lamellae chains contribute predominantly in deformations at this level, and the residual plastic strain can be attributed to permanent damage to the tie chains, affecting the long-term mechanical resistance of a molded part. With little detectable alteration of the polymer crystallinity at this early onset of plastic deformation, the primary characterization method applied to date is cyclic tensile loading, which provides information of stress-softening by monitoring the unloading path or relaxed stress behavior. An alternative method for monitoring the development of Mullins effect is proposed that can examine a molded part by using selected modes based on ultrasonic guided waves analysis. The technique was examined to determine if it could follow this effect induced by cyclic strain-controlled tensile deformations since it does not require sample preparation and could ultimately be applied while a part was in-service. Results for different polyethylene grades agree in trend with relaxed stress values over four cycles for tests of increasing applied tensile strain, demonstrated by an increase in the attenuation of ultrasonic guided waves. The correlation reveals a good promise in applying this method to structural health monitoring of plastic parts, while in use, to follow the initiation and progress of early service damage.

Effect of Polyethylene on the Physical and Mechanical Properties of Particleboard

SummaryParticleboard is a common material used in furniture manufacturing. In the present study, it is made from natural rubber wood in the form of coarse and fine particles which is glued with urea formaldehyde adhesive. Because of the cellulosic structure containing many hydroxyl groups, the particleboard becomes a hygroscopic product. The objective of the present study was to increase the water resistance of the particleboard by adding polyethylene (PE). Four grades of PE were selected and mixed with the rubber wood particles before forming as a three‐layer particleboard. Water absorption and thickness swelling were determined. The mechanical properties of the particleboard were evaluated including modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength (IB) and screw holding force. It is found that the addition of 5 wt% PE decreased the thickness swelling at 2 h, e.g. from 19.27% to 13.18–17.16%, and at 24 h, e.g. from 23.81% to 16.88–21.04%. The presence of 5 wt% PE also decreased the water absorption at 2 h, e.g. from 56.17% to 42.01–52.98%, and at 24 h, e.g. from 70.89% to 58.63–66.76%. LDPE D209 and LDPE 2420T showed high potential in this application because they enhanced the water resistance and slightly increased the internal bond strength of the particleboard. MOR and MOE of particleboard could be ranked in the following order: D209 > control > 2420T.

Measuring space radiation shielding effectiveness

Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles is described. Using accelerated alpha particles at the National Aeronautics and Space Administration Space Radiation Laboratory at Brookhaven National Laboratory, the method is applied to sample tiles from the Heat Melt Compactor, which were created by melting material from a simulated astronaut waste stream, consisting of materials such as trash and unconsumed food. The shielding effectiveness calculated from measurements of the Heat Melt Compactor sample tiles is about 10% less than the shielding effectiveness of polyethylene. Shielding material produced from the astronaut waste stream in the form of Heat Melt Compactor tiles is therefore found to be an attractive solution for protection against space radiation.

Modification of isotactic polypropylene by additives of low-density polyethylene and powdered cellulose

The effect of addition of low-density polyethylene and/or cellulose powder on the structure of isotactic polypropylene was investigated using methods of wide-angle X-ray scattering and differential scanning calorimetry. The effect of polyethylene and cellulose on the structure and properties of the crystalline phase of isotactic polypropylene was demonstrated.

Improved efficiency of reactor startup in biological aerated filter by poly(lactic acid)

The enhancement effect of polyethylene (PE) surfaces modified with poly(lactic acid) (PLA) on formation of nitrifying biofilms in biological aerated filter (BAF) was investigated in this study. X-ray photoelectron spectroscopy, scanning electron microscope, and protein absorption analysis revealed that modified PE surfaces produced active groups, including carboxyl (O═C─O), hydroxyl (C─OH), and carbonyl (C═O), increased surface roughness, and enhanced the adsorption of both the bovine serum albumin and fibrinogen. During the startup period of 33 days, the average removal rates of ammonia nitrogen (NH3-H) were 68 and 72% before and after modification which were 36 and 43% for total nitrogen, 47 and 45% for total organic carbon. The results of denaturing gradient gel electrophoresis experiments demonstrated that modified carriers adsorbed and gathered more species of bacteria on surfaces. Thus, surface modification of PE suspended carrier by PLA improved the efficiency of reactor startup for drinking water treatment.

Effects of polyethylene and polyurethane Teflon-fillers on the energy absorption behavior of composite tubes during the flattening tests

This article performs an experimental analysis on the E-glass/polyester and vinylester composite tubes with circular cross-section subjected to the lateral compression loading during the flattening process in three different filling conditions: empty, polyethylene, and polyurethane Teflon-filled. Energy absorption behavior and failure response of the composite tubes during the lateral compression tests in the quasi-static condition are studied. The effects of Teflon-type, Teflon-filling, Teflon wall thickness and length, tube inner diameter, fiber fabric layer, and tube length are investigated on the crashworthiness parameters of lateral load, total absorbed energy, and specific absorbed energy (SAE) of the circular composite tubes. The experiments introduce the cylindrical polyethylene Teflon with the large wall thickness as the appropriate filler into the composite tubes, but the experimental measurements show that filling the tubes by the polyurethane Teflon-filler has undesirable effects on the mechanical behavior of the flattened specimens. Also, according to the flattening tests, it is found that in the polyethylene Teflon-filled specimens, the tubes with the vinylester resin have the higher SAE, compared with the corresponding specimens with the polyester resin.

Effect of Polyethylene Grafted Maleic Anhydride (PEgMAH) on Tensile Properties and Swelling Behavior of Ethylene Vinyl Acetate (EVA)/ Natural Rubber (NR)/ Feldspar Composites

The effects of polyethylene grafted maleic anhydride (PEgMAH) as a compatibilizer on the tensile properties and swelling behavior of ethylene vinyl acetate /Natural Rubber/ Feldspar (EVA/NR/FP) composites were studied. The EVA/NR/FP composites with and without PEgMAH were prepared using Brabender Plasticoder at 160oC with 50rpm rotor speed. The results indicated that EVA/NR/FP/PEgMAH had higher value of tensile strength and M100 but lower elongation at break and percentage mass swell.

Comparison of low-energy [formula omitted] radiation effects in polyethylene and cellulose by molecular dynamics simulations

Using molecular dynamics simulations, we have compared the low-energy β radiation effects in high density polyethylene and cellulose. We determined the threshold energy for creating defects as a function of the incident angle, for a carbon atom in polyethylene chain, and for one of the carbon atoms in cellulose chain. Our analysis shows that the damage threshold energy is in the both cases strongly dependent on the initial recoil direction and on average slightly higher for the carbon atoms in the polyethylene chain than for the target carbon atom in cellulose chain. Additionally we performed two sets of recoil event simulations on polyethylene sample, with 50 and 100eV recoil energy, and compared the outcome with previously reported recoil event results for cellulose sample.

Electrical conduction in polyethylene: The role of positive charge and the formation of positive packets

A model for positive hole transport in polyethylene is developed which takes particular account of the crystalline-amorphous morphology of the polymer. The significant feature is the employment of super-exchange quantum mechanical tunneling to explain hole transport through the amorphous phase. The consequence is that the hole mobility exhibits a maximum as a function of the electric field, a manifestation of the inverse Marcus effect. It is shown that this feature accounts for the majority of the reported high-field hole transport effects in polyethylene, including packet formation.

Properties of Chicken Feather Fiber-Filled Low-Density Polyethylene Composites: The Effect of Polyethylene Grafted Maleic Anhydride

The effects of polyethylene grafted maleic anhydride on tensile properties, morphology, thermal degradation, and swelling behavior of low density polyethylene/chicken feather fiber composites were studied. The LDPE/CFF composites were prepared using a Z-Blade mixer at 180°C and rotor speed of 50 rpm for 15 min. LDPE/CFF/PEgMAH composites exhibit higher tensile strength, Young's modulus, and final decomposition temperature, but lower mass swell percentage and elongation at break than LDPE/CFF composites. SEM morphology showed that the chicken feather fiber more widely dispersed in the LDPE matrix with the addition of polyethylene grafted maleic anhydride as a coupling agent. It was also found that the addition of PEgMAH offers better thermal stability in LDPE/CFF/PEgMAH composites than LDPE/CFF composites.

Primary Radiation Defect Production in Polyethylene and Cellulose

Irradiation effects in polyethylene and cellulose were examined using molecular dynamics simulations. The governing reactions in both materials were chain scissioning and generation of small hydrocarbon and peroxy radicals. Recombination of chain fragments and cross-linking between polymer chains were found to occur less frequently. Crystalline cellulose was found to be more resistant to radiation damage than crystalline polyethylene. Statistics on radical formation are presented and the dynamics of the formation of radiation damage discussed.

Effect of Polyethylene on the Thermomechanical Properties of Green Rubber Mixes Based on 1675N Butyl Rubber and Skept-50 Ternary Ethylene–Propylene Copolymer Rubber

Effect of Polyethylene on the Thermomechanical Properties of Green Rubber Mixes Based on 1675N Butyl Rubber and Skept-50 Ternary Ethylene–Propylene Copolymer Rubber

Compatibilization Effects of PE-g-MA on Mechanical, Thermal and Swelling Properties of High Density Polyethylene/Natural Rubber/Thermoplastic Tapioca Starch Blends

Effect of polyethylene grafted maleic anhydride (PE-g-MA) on mechanical, thermal and swelling characteristic of high density polyethylene (HDPE)/natural rubber (NR)/thermoplastic tapioca starch (TPS) blends were studied. The measurements from differential scanning calorimetric (DSC), dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA), proved the effectiveness of PE-g-MA as compatibilizer in improving the miscibility between HDPE/NR – TPS blends. A decrement in crystallinity index was found after adding PE-g-MA. It is due to restriction in mobility of the HDPE chains. In the presence of PE-g-MA, the blends have better thermal stability. On top of that, the storage modulus which is reflected to the blend stiffness also increased as indicated the improvement in HDPE/NR – TPS interaction.

Low-Intensity Pulsed Ultrasound (LIPUS) May Prevent Polyethylene Induced Periprosthetic Osteolysis In Vivo

We investigated the effect of local low-intensity pulsed ultrasound (LIPUS) on polyethylene debris induced periprosthetic osteolysis. The periprosthetic osteolysis model was made by injecting endotoxin-free pure polyethylene particles into the distal part of the femur canal and inserting a stainless steel plug into this femur. The effects of polyethylene and LIPUS were assessed histologically and by the shear strength test and periprosthetic bone mineral density (BMD) test. Sixteen rabbits received a stainless steel plug on one side and both polyethylene and a stainless steel plug on the other side. Three months later, the side that received polyethylene showed periprosthetic osteolysis. Subsequently, another 16 rabbits received polyethylene plus local LIPUS (200 mW/cm 2 for 20 min daily) on one side and polyethylene alone on the other side. Three months later, LIPUS effectively prevented the periprosthetic osteolysis caused by polyethylene in this rabbit model.