Latex Material Research Articles

Development of an experimental technique to determine the barrier performance of medical gloves when stretched.

Protective clothing standards, such as test methods published by ASTM International, play an integral role in ensuring the performance of personal protective equipment. The standard tests are not without limitations and are periodically reviewed and often updated. Some tests may not be reflective of in-use conditions. A new test cell was designed using sanitary fixtures to evaluate the effect of glove stretch on barrier performance using fluorescein solution as the challenge agent for enhanced visualization and fluorometer detection. Domed-shaped and flat screens were developed to permit and limit glove stretch within the test cell. The barrier performance of glove swatches was evaluated for both stretched and unstretched states. Latex, nitrile, and vinyl glove models of various thicknesses were evaluated. The tests were conducted following pressure and time parameters specified in ASTM F903, ASTM F1670, and ASTM F1671. Fluorescein solution movement, which may occur through penetration, was measured using a fluorometer. Glove stretch caused a reduction in glove thickness ranging from 16% to 40%. Overall, 21 sample failures were found (16.7%; n = 126) regardless of test condition. Nitrile gloves provided better barrier efficacy with the lowest failure rates (2.38%; 1 failure out of 42) compared to latex (19.4%; 7 failures out of 36) and vinyl gloves (27.1%; 13 failures out of 48). Differences in failure rates between stretched and unstretched gloves were insignificant; however, the latex material showed a 2.5 times increase in failures when stretched compared to unstretched. The new test apparatus was able to differentiate between the barrier performance of different glove materials. The use of a domed screen allowed the gloves to stretch, a condition that better represents the state of gloves when in use. Analysis of samples collected from the glove surface opposite to the exposure may provide a way to assess chemical permeation in addition to penetration.

911 How to Design a Low-Cost 3D Printed Laparoscopic Appendicectomy Simulation Model (LaApSi)?

Abstract Aim To develop a Low-cost Laparoscopic Appendicectomy Simulation (LaApSi) Model and to assess its application for surgical simulation in UK & Lower Middle-Income Countries (LMICs). To ensure a realistic and accurate representation of the anatomy of the appendix and the laparoscopic appendicectomy procedure. Method Autodesk Fusion 360 software was used to design the appendix mould which was 3D printed using Ultimaker Tough PLA material. LaTeX material, Reschimica Shore 20 silicon was used & Validity Testing following simulation by HST using Face Validity & Likert 5-Point scale. LaApSi model has been recently used for the Laparoscopic workshop endorsed by RCSEd organised in LMICs and multiple times within the UK (Hull Suture Centre Laparoscopic Courses & East of England Laparoscopic course for Core Surgery). Results Successful Development of a local low-cost Appendix model (under £5) vs expensive market models. Prototype testing results & feedback from the users within and outside the UK are very positive and inspiring. The continuous evolvement of the LaApSi models based on the efficacy testing via face validity and Likert 5 Point Testing results has proved to be effective as evidenced by quantitative assessment where the users scored on Model specification shape, size and Texture: 90%, 96%, 92 % resemblance respectively. Conclusions The notion of creating low-cost LA simulation models provides a variety of potential benefits for surgical simulation in LMICs and the UK, and it warrants support from the industry and charity. These simulations aid in offering a standardised, affordable, and safe method for surgical training.

Screening of Phytochemicals and Anticancer Potential of Maclura Pomifera Leaves Extract

Introduction: Maclura pomifera, is small deciduous tree which is commonly called as Osage orange. It typically grows about 8 to 15 meters tall. Maclura pomifera secrete white latex material which is sticky in nature on damaging. The common name of this plant is not related with citrus fruit family “orange” Maclura pomifera belongs to mulberry family called Moraceae. Method: The extract of Maclura pomifera leaves was prepared by using ethanol as a solvent. The major groups of phytochemicals were present it such as, alkaloids, tannins, saponins, flavonoids and steroids. Results: The different parts of plants contain, alkaloids, flavonoids, and polyphenolic and many other bio-compound. Due to these compounds, plants posse’s antidiabetic, anti-cardiovascular, and anticancer activities. The leaves of Maclura pomifera extract possessed higher cytotoxic potential with IC50 78.9 µg/ml. The cytotoxic potential of extract was checked through MTT assay against the hepatic cancer (HepG2) cells, Conclusion: These bio-compounds are present in the Maclura pomifera, due to this reason, this plant is used against several disorders such as diabetes, cardiovascular and cancer. Which give the valuable results. Keywords: Phytochemicals, Anticancer, Cardiovascular, Maclura pomifera, Bio-compounds, Cytotoxic potential

Antioxidating and reinforcing effect of polydopamine functionalized silica on natural rubber latex films

AbstractSince the outbreak of COVID‐19, the demand for natural latex products with increased mechanical properties and aging resistance has surged. Based on the excellent adhesion and antioxidant properties of polydopamine (PDA), we employed a one‐pot method to modify the surface of silica substrates using PDA containing a polyphenol structure, to prepare a reinforced silica‐PDA composite latex material with antioxidant properties. As expected, the silica‐PDA composite achieved both uniform dispersion and good interfacial interactions with natural rubber latex (NRL). In addition, compared with common NRL/silica films, the mechanical properties of the NRL/silica‐PDA film were significantly improved; specifically, silica‐PDA can highly‐enhanced the mechanical property of NRL film from 24.94 to 32.18 MPa of tensile strength. Further, the antioxidant activity of the silica‐PDA film exceeded that of commercially available antioxidant D. Considering the notable performance boost of silica‐PDA composites on NRL films, we believe that the treatment of silica with natural polyphenols offers a convenient and facile new route for the preparation of environmentally friendly multifunctional silica additives.

Improvement of Emulsion Stability and Plugging Performance of Nanopores Using Modified Polystyrene Nanoparticles in Invert Emulsion Drilling Fluids.

Drilling fluid invasion and pressure transmission caused by the development of micropores and fractures in shale oil and gas formations are the major factors contributing to wellbore instability during drilling using oil-based drilling fluids (OBFs). In this study, a modified polystyrene latex (MPL) material was synthesized through emulsion polymerization and was characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), particle size analysis, scanning electron microscopy (SEM) observations, and contact angle testing. The influence of the MPL on the stability of a water-in-oil emulsion was analyzed via sedimentation observations and electrical stability tests. The effects of the MPL on the plugging mechanism of white oil and water-in-oil emulsions were evaluated using 0.1–1.0 μm micro-porous filtration films. The experimental results revealed that the MPL has a favorable thermal stability, with an initial thermal decomposition temperature of 363°C, a median particle size (D50) of 233 nm, and a three-phase contact angle of 103.5°. The MPL can enhance the sedimentation stability of an emulsion to a considerable extent and can improve the electrical stability (ES) of the emulsion, which is conducive to the stability of OBFs. Due to the deformability of the MPL, it has a wide range of adaptations for micro-scale pores and fractures. In both the white oil and water-in-oil emulsions, the MPL can reduce the filtration loss through microporous membranes with pore sizes of 0.1–1.0 μm to within 10 ml. This paper details the methodology of the synthesis of nanomaterials that can effectively plug a formation’s nanopores and fractures; thereby, stabilizing OBFs.

The Acceptance of Rubber Dam Isolation by Patients undergoing Endodontic Treatment and Its Feedback: A Questionnaire Based Survey

Objective: The study was done to evaluate the average time taken by the operators to apply the rubber dam, procedure time and the acceptability or rejection of placement of rubber dam by the patients during endodontic treatment procedures.
 Design: The study was carried out on 450 patients requiring endodontic treatment reported at department during the time interval of May, 2021 to August, 2021. Out of 450 patients, 180 patients were randomly selected for the study by lottery method. All the endodontic procedures were performed under rubber dam isolation and rubber dam application time and time for isolation was determined. Further, a questionnaire survey was performed to evaluate the patient’s acceptance or rejection of procedures rubber dam and various reasons for rejection.
 Results: The highest number of respondents belonged to 21-30 years of age group i.e. 26.6% followed by 31-40 years i.e. 26.11%. Average rubber dam application time and procedure time were estimated as 4.04 and 44.07 minutes respectively. More than 90 % of the participants were willing to accept the procedure under rubber dam isolation in future. However, on contrary, only 9.44 % of the participants rejected the procedure under rubber dam isolation and the most common reasons for rejection were uneasiness felt by the patient and difficulty in breathing.
 Conclusions: The acceptability of rubber dam isolation while performing endodontic procedures/ treatments was quite significant among the patients. Very few patients had allergy to the latex material of rubber dam sheets and respiratory disorders.

Physical Characterization of Material for the Development of Orthopedic Orthosis for Diabetic Foot

The diabetic foot is characterized by the loss of foot ulcerations and sensitivity. The use of orthopedic orthosis can prevent pathological changes in the diabetic foot. The objective of this study was to characterize materials used for producing orthopedic orthosis: silicone; pre-vulcanized latex of Hevea brasiliensis; Evapod, and Podadur. The Hevea brasiliensis latex material is widely indicated in the literature for biomedical purposes. Physical–mechanical properties were determined (properties of elastic deformation, resistance, durability, lightness, energy absorption, resistance to high temperatures, and chemical composition—ASTM International). In the tensile test, the latex reached 6.02 ± 0.33 MPa, having the best performance among the other materials. In the elastic module, the Podadur stood out, with 28.2 ± 0.89 MPa, compared to silicone with 0.42 ± 0.05 MPa. The most excellent Shore A hardness material was Podadur with 58%. As for the resilience, the Podadur presented a minimum value of 22%, while latex had 63%. Silicone was the densest material, with a density of 1.48 g/cm3, and Evapod and Podadur were the lightest, respectively, at 0.22 g/cm3 and 0.42 g/cm3. Morphologically, Evapod, Podadur, and latex presented open and interconnected cells, characteristics that gave them a more significant water absorption capacity. Silicone was the only material with no empty cells in its structure. In X-ray diffraction, Evapod, Podadur, and silicone materials presented well-defined crystallographic planes, whereas amorphous behavior characterized latex. Thermogravimetry showed weight loss between 240 and 650 °C in the four materials. In the fluorescence test, the presence of metals was observed in the composition of the four materials. Among the materials studied, the Podadur was the material that stood out, with some good properties for the development of orthopedic orthosis.

Effect of rubber polymeric materials on moisture susceptibility of asphalt mixtures: Optimization and evaluation study

Pavements made with plain asphalt mixtures are subjected to premature failures due to the exposure to moisture. Polymers are one of the promising additives that are commonly used to extend the service life of asphalt mixtures. This paper evaluates the moisture sensitivity of asphalt mixtures using rubber polymeric materials such as crumb rubber and centrifuged latex. The crumb rubber material is collected from scrap tires (powder form), while the centrifuged latex material is extracted from hevea brasiliensis rubber tree (liquid form). Both crumb rubber and centrifuged latex polymeric materials are incorporated through the wet process at different percentages i.e., 2%, 4%, 6%, 8%, and 10% by the weight of the binder. The optimum crumb rubber and centrifuged latex contents are 8% and 6%, respectively, as per the storage stability test. Then moisture sensitivity of unmodified and rubber modified mixes is analyzed through different laboratory tests: marshal stability ratio, tensile strength ratio, and resilient modulus ratio. The tests clearly show that asphalt mixes exhibit higher moisture resistance with crumb rubber and centrifuged latex polymeric materials. In terms of marshal stability ratio and tensile strength ratio tests, crumb rubber material gives better moisture damage resistance than centrifuged latex material. The cost analysis reveals that rubber-modified mixes show slightly higher costs than unmodified mixes; however, this cost variation is insignificant. As a whole, pavements made with rubber-modified asphalt mixes have longer durability due to its higher moisture damage resistance.

Abrasion Resistant/Waterproof Stretchable Triboelectric Yarns Based on Fermat Spirals.

Emerging energy harvesting yarns, via triboelectric effects, have wide application prospects in new-generation wearable electronics. However, few studies have been carried out regarding simultaneously achieving high electrical performance, mechanical robustness, and comfortability in industrial-scalable yarn. Here, an electronic yarn twisted into Fermat spiral, which has outstanding dynamic structure stability, is reported. The Fermat-spiral-based energy yarns (FSBEY) can simultaneously realize ultrahigh abrasion resistance (over 5000 Martindale standard abrasion cycles), stable reversible strain (100%), and excellent electrical output. Considerably high output (105V, ≈1.2 µA under 2Hz) can be attained upon contacting a single yarn (30cm) with latex material, which is superior to most state-of-the-art stretchable triboelectric yarns. The application of these FSBEY in wireless gesture recognition, smart screen information protection, and harvesting of energy from water dropletsis demonstrated. Moreover, textiles knitted from the FSBEY have distinguished waterproof nature and are breathable. This work shows a feasible proposal for building future "energy garments".

Research on Fatigue Performance of Palm Fiber Mattress

The palm fiber mattress is made of palm fiber and natural latex material. In recent years, with the society's environmental protection requirements and the sustainable development of resources, more and more researches on its performance have been made. In this paper, through the compression fatigue test of the palm fiber mattress test block, simulate the impact of human sleep on the mattress under 8 hours a day, study the fatigue performance of the palm fiber mattress under different loads, and analyze the experiment to find that the palm fiber mattress The stress-strain curve of the fiber mattress test block and the deformation of the mattress test block. Finally, the obtained results were subjected to finite element simulation and linear fitting, and the calculated results were consistent with the experiments, which proved the validity of the experimental data.

Mechanical Properties Optimization of the Elastomeric Matrix Reinforced Composite Material with Cabuya Fiber, Using the DOE/Complete Factorial Design and Desirability Function

The development of green composites to obtain scientific, technological and industrial application benefits, and evaluate different mechanical properties of those materials; as well as the great growth and the global market demand being considered as lightly and low manufacture cost materials, that has mechanical and physical properties equal or higher that will replace the materials that are traditionally seen in industry. Applying an analysis based in the experiments design (DOE) plus experimental essays, a mechanical characterization of composite material latex reinforced with short cabuya fiber was performed with random orientation and volumetric fractions of 20% latex - 80% cabuya fiber, 30% latex-70% cabuya fiber, 45% latex – 55% cabuya fiber; for the different combinations. Of the essays that were performed it was determined the test tubes that show better results in its mechanical properties through the UNE Norm (Tensil UNE - ISO 37, Compression UNE - ISO 7743, Strength UNE - ISO 48). With the analysis developed by the statistical methodology based on the complete general factorial design and the desirability function it was able to determine the best mechanical characteristics of the composite material that will be used, was the composite formed by fiber with 1 centimeter of length and a volumetric fraction of 20% Latex – 80% Cabuya.

Epoxidised natural rubber (ENR) latex: an alternative raw material for latex dipped products

The utilisation of epoxidised natural rubber (ENR) for latex products is limited due to the inability of the ENR latex to form film through typical coagulant dipping processes. This is due to the low total solid content (TSC) and the presence of the non-ionic surfactant in the ENR latex. To use the ENR latex for dipping applications, concentration process via membrane technology is used to reduce the surfactant level in the latex and increase the TSC of the ENR latex material. The current study focuses on two grades: 25% and 50% epoxidation levels of concentrated ENR latex as starting materials and the typical latex compounding behaviour, such as pH, zeta potential, particle size and viscosity, was also analysed to understand its characteristic. Results, such as pH, zeta potential, and particle size, were acceptable and suitable to be used for dipping purpose and it passed the general latex properties of compounding. The cure measurement, such as chloroform number and total swelling index, showed ENR latex is fully vulcanised after 2 days of maturation. On the aspect of physical characteristics of the ENR 25 and 50 films, it resulted with high tensile strength (23.7 MPa) and met the specification of Standard Malaysian glove (SMG). The ability for dipping was satisfactory as smooth continuous film was formed. Aside from that, oil-resistance test and contact angle were also analysed to understand its resistance to oil upon time and wettability parameter of the ENR films.

Foundations of Advanced Neuroanatomy: Technical Guidelines for Specimen Preparation, Dissection, and 3D-Photodocumentation in a Surgical Anatomy Laboratory.

Objective This study was aimed to provide a key update to the seminal works of Prof. Albert L. Rhoton Jr., MD, with particular attention to previously unpublished insights from the oral tradition of his fellows, recent technological advances including endoscopy, and high-dynamic range (HDR) photodocumentation, and, local improvements in technique, we have developed to optimize efficient neuroanatomic study. Methods Two formaldehyde-fixed cadaveric heads were injected with colored latex to demonstrate step-by-step specimen preparation for microscopic or endoscopic dissection. One formaldehyde-fixed brain was utilized to demonstrate optimal three-dimensional (3D) photodocumentation techniques. Results Key steps of specimen preparation include vessel cannulation and securing, serial tap water flushing, specimen drainage, vessel injection with optimized and color-augmented latex material, and storage in 70% ethanol. Optimizations for photodocumentation included the incorporation of dry black drop cloth and covering materials, an imaging-oriented approach to specimen positioning and illumination, and single-camera stereoscopic capture techniques, emphasizing the three-exposure-times-per-eye approach to generating images for HDR postprocessing. Recommended tools, materials, and technical nuances were emphasized throughout. Relative advantages and limitations of major 3D projection systems were comparatively assessed, with sensitivity to audience size and purpose specific recommendations. Conclusion We describe the first consolidated step-by-step approach to advanced neuroanatomy, including specimen preparation, dissection, and 3D photodocumentation, supplemented by previously unpublished insights from the Rhoton fellowship experience and lessons learned in our laboratories in the past years such that Prof. Rhoton's model can be realized, reproduced, and expanded upon in surgical neuroanatomy laboratories worldwide.

Cystic lesion caused by latex material.

Treatment of a maxillary second premolar with an associated cystic lesion through conventional endodontic therapy combined with decompression and cyst enucleation is reported. Although cystic lesions frequently heal simply with endodontic therapy, refractory large lesions after nonsurgical endodontic treatment may require additional diagnosis and treatment. In this case, conventional root canal treatment resulted in incomplete healing and required further surgery. Following cyst enucleation with biopsy of the lesion and apical surgery on the tooth, the cause of the refractory lesion was found to be associated with foreign latex material in the periapical tissue, which was speculated to have originated from exposure to a dental glove. At the 1-year follow-up visit, the lesion exhibited continued resolution.

RANCANGAN MEJA DAN KURSI SORTASI RSS (RIBBED SMOKED SHEET) YANG ERGONOMIS MENGGUNAKAN PENDEKATAN ANTHROPOMETRI (Studi Kasus PTPN XII Banjarsari)

Rubber is an export commodity which gave the country’s contribution in increasing Indonesia's foreign exchange effort. PTPN XII Banjarsari isone of the industries which process the latex material. From the whole processing stages, the sorting-part workers were the workers who complained the most about work discomfort. A sorting table with no cavities for the feet would caused workers complain about knee and calf pain. This study aimed to redesign the sorting chair and table based on the anthropometry principle. This research was expected to create table and chair sortation design that can reduce workers’ complaints in order to increase productivity and reduce human error. The data collecting method was done by 3 steps, they were interview, questioner, and direct measurement. Then, the obtained anthropometric data was made into the most appropriate sorting design of chair and the table based on the worker's posture and it was tested on the employee’s complaints, productivity and human error. The results showed that the redesign of the tables and chairs on RSS sortation caused the complaint of sorting workers in PTPN XII Banjarsari decreased. Productivity increased to 8.6%. Human error had decreased, before the redesign it was 8.1% and decreased to 1.9%. The lighting source before redesigned did not fulfill the lighting standard, therefore the redesigned lighting source used an 8 watt LED flourecent with average intensity of 685 lux. It was compatible with the lighting standard to do work that requires average intensity between 500 to 100 lux (Kuswono, 2014).
 Keywords: anthropometric, ergonomic, RSS

BIAXIAL RESPONSE OF RUBBER AND RAT RIGHT-VENTRICLE TISSUE

The objective of this study is to evaluate the differences in deformation presented by a latex material and a Rat Right-Ventricle tissue under biaxial loading. In order to perform the testing, it was used a planar biaxial loading technique, and the collected data was used to measure the stretching response of each material. The samples were stretched in both directions (x and y axis) at the same time, until the reference markers placed on the materials reached a deformation of 10 % of its original distance from the initial position. Isoparametric mapping was used to analyze the markers displacement, and according to the results, it was possible to map the deformation response of both types of material, and correlate that to its mechanical properties.

Immersed multilayer biodegradable ureteral stent with reformed biodegradation: An in vitro experiment.

Objective The aim of this study was to develop a novel immersed multilayer biodegradable ureteral stent with reformed biodegradation and evaluate it in vitro. Methods Poly(glycolic-co-lactic acid) (PGLA), microsphere zein and BaSO4 were employed to produce a multilayer biodegradable stent using immersion technology. Tests of the biodegradable stents and conventional control stents were conducted in human urine in vitro to evaluate the biodegradable properties. The biocompatibility was assessed by the morphology and proliferation of urine-derived cells cultured with extracted media from the biodegradable stent and a latex material positive control. Results An immersed multilayer biodegradable stent was successfully produced. It began to degrade in week 2 and was fully degraded by week 4. The mass loss ratio in the first 2 weeks was low (approximately 10.0% at 1 week, 20.0% at 2 weeks) and increased after 3 weeks (approximately 70%) to the end of testing. During the first 2 weeks, the radial compression load performances of the biodegradable stents were better than those of the control stents with statistically significant differences ( p = 0.00, p = 0.01) and the tensile strengths were lower in the biodegradable stents than those in the control stents throughout the experiment. SEM showed that the stents degraded layer by layer from the outer to the inner wall. The influences on the cells of extracted medium from the biodegradable stents were morphologically slight and lower than 10% in relative growth rates. Conclusions This preliminary study demonstrates that the immersed multilayer biodegradable ureteral stent has good radial compression and biocompatible performance and can be degraded in vitro within 4 weeks in a moderate manner.

Synthesis and characterization of polymer-silica hybrid latexes and sol-gel-derived films

Sol-gel derived organic-inorganic hybrid systems were obtained by applying alkaline-catalyzed co-hydrolysis and copolycondensation reactions of tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), isobutyltriethoxysilane (IBTES), diethoxydimethylsilane (DMDES), and vinyltriethoxysilane (VTES), respectively, into a polymer latex functionalized with vinyltriethoxysilane (VTES). The properties of the latex hybrid materials were analyzed by FTIR, water contact angle, environmental scanning electron microscopy (ESEM), TEM and AFM analysis, respectively. FT-IR spectra confirmed that the chemical structures of the sol-gel derived organic-inorganic materials are changed as function of inorganic precursor and SiOSi networks are formed during the co-hydrolysis and copolycondensation reactions. The water contact angle on the sol-gel latex film containing TEOS+VTES increased to 135°±2 compared to 65°±5 for the blank latex, due VTES incorporation into latex material. TGA curves of hybrid sample modifies against neat polymer, the thermal stability being influenced by the presence of the inorganic partner. ESEM analysis showed that the latex hybrid films prepared with different inorganic precursors were formed and the Si-based polymers were distributed on the surface of the dried sol-gel hybrid films. TEM and AFM photos revealed that the latex emulsion morphology was modified due to the VTES incorporation into system.

Surface Tension Effect on Sound Absorption Characteristics of a Cavity-Backed Semi-Permeable Membrane

This paper describes the analysis on the characteristics of semi-permeable membrane sound absorber. The effects of membrane surface tension on the sound absorption characteristics were investigated. The characteristics of the membrane absorber was measured experimentally in terms of Sound Absorption Coefficient, α and Noise Reduction Coefficient, NRC. The membrane is made of thin, flexible, semi-permeable latex material and the tests were carried out by using impedance tube method according to ISO 10534-2 standard. The results showed that the surface tension has significant influence on the sound absorption characteristics. For the parameters used in the laboratory work, specimen with unstretched surface tension has the best absorption performance.

Biological safety evaluation of the modified urinary catheter.

The purpose of this study was to evaluate in vitro safety of the novel tosufloxacin (TOS)-treated catheters with the prolonged antimicrobial activity. The test samples of silicone latex catheter were prepared by the immobilization of TOS on chitosan (CHIT)-coated catheter by means of covalent bonds and non-covalent interactions. Each step of the modification process of catheter surface was observed using ATR-Fourier transform infrared spectroscopy. In vitro cytotoxicity of the modified and unmodified catheters was assessed by direct and indirect tests in accordance with ISO standards using green monkey kidney (GMK) cell line. The MTT, lactate dehydrogenase activity (LDH), WST-8, Sulforhodamine B (SRB) test results and microscopic observation clearly indicated that unmodified silicone latex catheters decrease cell metabolic activity, act as a cytotoxic agent causing cell lysis and induce cell death through necrotic or apoptotic process. We suggest that chitosan coat with TOS immobilized limits leaching of harmful agents from silicone latex material, which significantly enhances survivability of GMK cells and therefore is quite a good protection against the cytotoxic effect of this material.