Thin Plastic Sheet Research Articles

Determination of kilovoltage x-ray therapy depth doses with open-ended applicators.

The purpose of this work was to determine percentage depth dose (PDD) curves for kilovoltage x-rays from the WOmed-T105 unit, with open-ended steel applicators and beam qualities ranging from 0.5 to 4.2mm Al. Measurements were made with parallel plate chambers in a water phantom, with extrapolation based on a fifth order polynomial used to estimate the surface dose. Measurements were also made with parallel plate chambers in a plastic water phantom, with thin plastic sheets used to obtain detailed measurements at shallow depths (less than 1mm). Monte Carlo simulations were performed using the EGSnrc package, with two different sources as input: a SpekPy simulation of the x-ray beam and a full simulation of the x-ray tube, treatment head and applicators. Results showed that all four methods (two measurements and two simulations) agreed within the measurement uncertainty at depths greater than 2mm. At shallow depths, significant differences were noted. At depths less than 0.1mm, the full Monte Carlo simulation and the solid water measurements showed a sharp spike in surface dose which is attributed to electron contamination, which was not seen in the SpekPy Monte Carlo simulation or the extrapolated water measurements. At depths between 0.1mm and 2mm, beyond the range of contaminant electrons, the extrapolated water measurements underestimate the dose by up to 13% compared to the full Monte Carlo simulation and the solid water measurements, attributed to fluorescent photons generated in the applicators. This work demonstrates that for open-ended applicators, measurement of depth doses in water with extrapolation of surface dose has the potential to significantly underestimate the dose at shallow depths between the surface and 2mm, even after eliminating electron contamination from the beam.

Characterization of Shrink Film Properties for Rapid Microfluidics Lab-on-Chip Fabrication.

Shrink film is a thin sheet of polystyrene plastic that shrinks to 25-40% of its original size when heated. This study investigated the shrinkage factor of the film at different temperatures and baking times to determine the optimal fabrication recipe for shrink film microfluidic device production. Additionally, this study characterized the properties of shrink film, including minimum possible feature size and cross-section geometries, using manual engraving and the CAMEO 4 automated cutting machine. The optimal shrinkage factor ranged from 1.7 to 2.9 at 150 °C and a baking time of 4 min, producing the ideal size for microfluidic device fabrication. The X- and Y-axes shrank ~2.5 times, while Z-axis thickened by a factor of ~5.8 times. This study achieved a minimum feature size of 200 microns, limited by the collapsing of channel sidewalls when shrunk, leading to blockages in the microchannel. These findings demonstrate the feasibility and versatility of using shrink film as a cost-effective and efficient material for the rapid fabrication of microfluidic devices. The potential applications of this material in various fields such as the medical and biomedical industries, bacteria and algae culture and enumeration are noteworthy.

Particle removal performance of a novel ESP type air cleaning system for indoor air quality in a subway station

A novel electrostatic precipitation type air cleaning technology with near zero ozone emission for indoor air quality of a subway station was developed. To minimize ozone emission and achieve high particle removal performance against ultrafine particulate matters (PMs), a multi-channel charging method using soft ionization by micrometre carbon fibers and a narrow gap collection method using high electric field by thin conductive plastic sheets as a high voltage electrode were used. In this study, the novel electrostatic charging and collection technologies were applied to a real scale air cleaning system in an Air Handling Unit (AHU) with air flow rate of 950 m3/min in Yuseong Oncheon subway station with an area of 3000 m2 in Daejeon, South Korea. The particle removal performance of the demonstration system was evaluated with real suspended particles in the subway station during test period with high PM concentrations in Korea over 40 μg/m3. Particle collection efficiency, pressure drop and ozone emission were evaluated, and compared to those of the a minimum efficiency reporting value (MERV) 10 and 14 filters used in the typical subway stations in Korea. In the field researches, the developed ESP achieved over 80% of the PM collection efficiency higher than those of the filters with MERV-10 and -14, and even 10% higher efficiency against PM1.0, while generating only 10% of pressure drop and also emitting nearly zero ozone. It is concluded that a novel ESP type air cleaning system with near zero ozone emission could be a promising air cleaning method for a large indoor environment such as a subway station where polluted air with ultrafine particles flowed in with a very high flow rate.

Homemade BIOPLASTICS (Biodegradable Plastic From Cassava Peel Waste) with Analysis of the Effect of Glycerol and Cellulose Ratio on Tensile Strength, Elongation, and Thickness

The massive use of plastic as food and non-food packaging does not cause a few problems. The accumulation of plastic waste can cause environmental pollution, both water and soil pollution, because plastic will be damaged and decomposed within 300 to 500 years. For this reason, environmentally friendly plastics are needed for conventional plastics which of course have characteristics that are not far inferior to conventional plastics such as flexible, lightweight, not easy to break, waterproof, not corrosive. Bioplastic is a type of plastic that can be degraded so it is not harmful to the environment. This paper aims to see the effect of the ratio of glycerol and cellulose on tensile strength, elongation, and thickness of bioplastics using cassava peel waste. This research uses cassava peel as the basic material for making starch which is then given a mixture of glycerol and cellulose to be used as bioplastics. Tensile strength and elongation tests were carried out using the zwick/roell Universal Testing Machine (UTM). While the thickness uses Mitutoyo's Thickness Gauge. The results obtained are thin plastic sheets made using 5 grams of starch with a mixture of cellulose (0.4; 0.6; 0.8) grams and glycerol (100%, 150%, 200%) ml which have been tested for mechanical properties. The best mechanical properties of the tensile strength of bioplastics were indicated by the sample coded C2G2 with a concentration of 1.5 ml of glycerol and 0.8 gram of cellulose with an average tensile strength of 7.4808 (N/mm2), while the highest elongation was shown in the sample coded C3G3. with a concentration of 2.0 ml of glycerol and 0.8 grams of cellulose with an average sample elongation value of 6.2448%, while the highest thickness determined in the sample coded C2G2, a concentration of 1.5 ml of glycerol and 0.6 grams of cellulose with a value of the average thickness is 269,066 (µm).

Simple route to performance modulation of resistive strain sensor based on strain-engineered stretchable substrate with customized hard template

Despite recent remarkable advances in wearable strain sensors, it remains challenging to achieve a high sensitivity and high stretchability simultaneously within a single device. Herein, we present a simple yet universal route to geometric modulation of elastomeric substrates based on customized hard templates for systematically optimizing the sensing performance of stretchable strain sensors. The hard template is simply prepared by patterning a thin plastic sheet using a facile cut-patterning process and entirely embedded into elastomeric substrates to redistribute the surface strain upon stretching in a programmable manner. The proposed strain-engineered stretchable (SES) substrates with various designs of the hard templates are easily integrated with silver nanowire (AgNW)/elastomer composite sensory films and play a crucial role in achieving balanced sensing performance of the strain sensors. The AgNW/SES (AS) strain sensor exhibits a high stretchability (68%) and high mechanosensitivity (gauge factor of ∼4.5 at 0–25% and ∼33 at 25–68%) while exhibiting long-term performance stability (1000 stretching cycles at 30% strain). Owing to their excellent sensing performance and mechanical flexibility, the AS strain sensors are successfully used to monitor a wide range of strains caused by human activities during exercise, indicating the potential as practical wearable devices for real-time motion detection.

Exploiting Thermoplasmonic Effects for Laser‐Assisted Preparation of Au Nanoparticles/InZnO Thin Film with Visible Range Photodetection Properties

AbstractHere, a new method is proposed for preparing gold nanoparticles (Au NPs)/indium‐zinc‐oxide (IZO) nanocomposite thin films based on photothermal mechanisms with near‐Infrared (NIR) laser annealing, which allows integrating the nanomaterial on fragile substrates such as thin glass, plastic sheets, or 3D printed pieces. The Au NPs are first prepared by NIR laser dewetting of a thin Au layer. Then, the Au NPs are used to locally cure the semiconductor material and provide suitable electronic properties owing to their efficient thermoplasmonic effects under the NIR laser annealing conditions. Finally, the electronic properties of the Au NPs/IZO thin films are characterized in the dark and under light excitation. Good photoresponsivity at 410 nm (UV, >100 A W−1) is demonstrated, but interestingly, the presence of Au NPs significantly improves the detection ability to a longer wavelength range, such as to 515 nm (green, ≈5 × 10−3 A W−1), even extending to 630 nm (red, ≈5 × 10−4 A W−1), and 780 nm (NIR, ≈10−4 A W−1). In addition, with the critical evaluation of dynamic light detection and lifetime trace (>22 d), the laser‐annealed Au NPs/IZO photodetectors demonstrate useful operating reliability and stability.

Mailing viable mouse freeze-dried spermatozoa on postcards

SummaryFreeze-drying techniques allow the preservation of mammalian spermatozoa without using liquid nitrogen. However, the current method requires the use of glass ampoules, which are breakable, expensive, and bulky to store or transport. In this study, we evaluated whether mouse freeze-dried (FD) spermatozoa can be preserved and transported on thin materials. In this study, we demonstrated that FD sperm can be preserved in thin plastic sheets. Its DNA integrity was comparable to that of glass ampoule spermatozoa, and healthy offspring were obtained after preservation at −30°C for more than 3 months. We attached preserved FD sperm to postcards, and transported these to other laboratory inexpensively at room temperatures without any protection. This method will facilitate the preservation of thousands of mouse strains in a single card holder, promote collaboration between laboratories, conservation of genetic resources, and assisted reproductive technology.

Relief of Keloid-associated Symptoms by Topical Application of Thin Plastic Sheets.

Relief of Keloid-associated Symptoms by Topical Application of Thin Plastic Sheets.

Analysis of the Voltage-Dependent Plasticity in Organic Neuromorphic Devices

The bias-dependent signal transmission of flexible synaptic transistors is investigated. The novel neuromorphic devices are fabricated on a thin and transparent plastic sheet, incorporating a high-performance organic semiconductor, dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene, into the active channel. Upon spike emulation at different synaptic voltages, the short-term plasticity feature of the devices is substantially modulated. By adopting an iterative model for the synaptic output currents, key physical parameters associated with the charge carrier dynamics are estimated. The correlative extraction approach is found to yield the close fits to the experimental results, and the systematic evolution of the timing constants is rationalized.

Programmable Hierarchical Kirigami

AbstractKirigami—the Japanese art of cutting paper—has recently inspired the design of highly stretchable and morphable mechanical metamaterials that can be easily realized by embedding an array of cuts into a sheet. This study focuses on thin plastic sheets perforated with a hierarchical pattern of cuts arranged to form an array of hinged squares. It is shown that by tuning the geometric parameters of this hierarchy as well as thickness and material response of the sheets not only a variety of different buckling‐induced 3D deformation patterns can be triggered, but also the stress–strain response of the surface can be effectively programmed. Finally, it is shown that when multiple hierarchical patterns are brought together to create one combined heterogeneous surface, the mechanical response can be further tuned and information can be encrypted into and read out via the applied mechanical deformation.

Money for nothing: The possible use of recycled fish farm material as habitat for lumpfish

The use of lumpfish in salmon farming allows the removal of sea lice all year round, without the use of chemicals or mechanical treatments. For cleanerfish to perform effectively, husbandry is key. Within the husbandry requirements is the placement of habitats in salmon cages, to allow the cleanerfish to rest and shelter. Habitats currently used can be costly, and require manual labour efforts to be removed from salmon pens to dry biofoulants, which could potentially be an unwanted food source for the cleanerfish. This study analysed preference of different materials from a recycled fish farm source (walkway, feed pipe, cut feed pipe, plastic sheet), to develop a cost effective, easy to use, lumpfish hide for sea pen deployment. Preference for different colours of the preferred substrate was subsequently investigated. Initially the juvenile lumpfish preferred the thin sheet of plastic over the recycled substrates, but towards the end of the trial there was no significant difference found between the plastic sheet and the recycled feed pipe tubes and walkway tubes. This indicates that it is possible to use low-cost, recycled material as substrate, and hides, for lumpfish in salmon farms. The colour trial indicated a clear preference for the colour black by lumpfish.

Experimental study of metal cushion pads for high speed railways

The widespread use of railway concrete sleepers/slab track has led to the evolution of fastening systems towards the use of elastic rail pads. Pads are interposed between the rail and the sleeper as damping elements to minimize the transmission of shocks and vibrations to the sleeper, this function being of particular importance for high-speed railways. Polymeric materials have been extensively used to manufacture resilient rail pads. Plastics, however, suffer from a series of intrinsic limitations since the environmental agents (UV rays, temperature, air humidity, etc.) as well as the compressive fatigue loads they are subjected to, negatively affect their mechanical properties over time. This study proposes the use of a novel solution, the so-called ‘metal cushion’ pads, as a reliable alternative to polymer pads. Metal cushion pads are made of stainless steel wire, knitted, embossed and cold-pressed down into a mold to achieve the required shape and size. The thorough experimental scope carried out in this research includes the following tests: (i) static and dynamic stiffness, (ii) fatigue aging, (iii) electrical resistance and, (iv) corrosion resistance. The values of static and dynamic stiffness are very similar to those obtained with other traditional polymers such as EVA and TPE-M. In addition, it has been found that the stiffness of the metallic solution can be modified by changing the diameter and density of the wire. In the case of fatigue aging, the foremost wearing suffered by the metal cushion pads occurs mainly in the early cycling stages, although the total damage is comparable to that of the traditional solutions. The electrical resistance of the metal cushion does not fulfill the requirements demanded by the international standards; however, its behavior is satisfactory if the metallic solution is combined with a thin plastic sheet. Finally, the metal samples have passed the corrosion test in a saline environment without showing any signs of corrosion damage.

Synthesis of biodegradable plastic from tapioca with N-Isopropylacrylamid and chitosan using glycerol as plasticizer

One of natural polymers that can be used as raw material in the manufacture of biodegradable plastic is tapioca and chitosan. The addition of other compounds such as glycerol as plasticizer is to improve the characteristics of the plastic that already produced. N- Isopropylacrylamid (NIPAm) is an organic compound that can be synthesized into a polymer or polymer grafting which also biodegradable too. This research aims tostudy the synthesis of biodegradable plastics from tapioca with the addition of chitosan, NIPAm, poly(NIPAm) and analyze the characteristics of biodegradable plastics that already produced. This research was done in three stages, there are (1) polymerization NIPAm, (2) the grafting of chitosan-poly NIPAm and (3) the synthesis of biodegradable plastics from starch mixture with variation of addition chitosan, NIPAm, poly(NIPAm), chitosan-graft-poly(NIPAm) and also variations of glycerol as plasticizer. The results of this research is a thin sheet of plastic which is will get analyzed for the characteristics of functional groups, mechanical, morphological and its biodegradability. FTIR spectra showed the grafting process with the new group formation of CO single-bond at 850 cm-1. Plastic with the addition of NIPAm and 1 ml glycerol has the highest tensile strength value about 31.1 MPa. Plastic with poly(NIPAm) and 4 ml glycerol produces the highest elongation value about 153.72%. Plastic with Chitosan-graft-poly(NIPAm) with 1 ml glycerol has the longest biodegradation because of the small mass-loss for six weeks which is about 6.6%.

In-situ monitoring of electro-deposition for iron-nickle thin film by time-resolved X-ray absorption spectroscopy

The crystal structure of iron-nickel thin films depends on the composition of iron and nickel dissolved with electrolytes. However, it is believed that in electro-deposition the iron and nickel ions are homogenous distribute in the solution and should provide the uniformly homogenous alloy thin film. Due to differences in ion mobility and sticking condition of iron and nickel ions, the real time investigation of electro-deposition of these alloy thin films were investigated by TRXAS during the applying current into the solution. In this work, the electrochemical cell consists of two 2.0 x 2.0 cm2 indium tin oxide (ITO) coated on thin plastic sheets for anode and cathode. These two electrodes separate by placing other two thin plastic sheets at the edges with the total thickness of 0.1 cm. The electrochemical cell is electro-deposited at the current density value of 0.25 mA/cm-2 for 10 minutes and collect the TRXAS data every 20 s with Fe K-edge (7112 eV) and Ni K-edge (8333 eV) at beam line 2.2, Synchrotron Light Research Institute (SLRI). Moreover, the intensity of X-ray at Fe edge dramatically decreases as the Fe ion deposits on the electrode. The slightly shift of Fe edge indicate the metal film forming i.e. Fe(II) ions convert to Fe(0) film. In addition, the signal of Fe(II) ion in R space also decrease as increasing the deposition time while the component at the nearest neighbor position of Fe metal alloy (at about 2Å) slight increase. However, the scattering signal of alloy at 1st nearest neighbor cannot determine the BCC and FCC crystal structure. These are needed the signal at the third and fourth nearest neighbor which are very weak at this initial deposition.

Quantitative Detection in Lateral Flow Immunoassay Using Integrated Organic Optoelectronics

A low cost, disposable point-of-care (POC) diagnostic device with integrated organic optoelectronic devices has been investigated for quantitative detection. The diagnostic component consists of a lateral flow immunoassay (LFIA) paper-based biosensor that uses capillary action for transportation of fluids. The absence of external fluid pumps and the low cost of materials utilized make LFIA a simple, inexpensive POC diagnostic device. For detection, the LFIA was integrated with organic optoelectronics devices on thin plastic sheets as a step toward a fully integrated lab-on-chip device. Organic semiconductor devices are suited for this purpose as they can be formed on many types of substrates and can have relatively large active area. For the light emitting component, phosphorescent green emitting organic light emitting diodes (OLED) have been used owing to their high brightness, while for the light detector an organic photodiode (OPD) that absorbs at green wavelengths has been used. Quantitative measurements were performed using optical transmission mode through the LFIA strip that forms red test and control lines by accumulation of gold nanoparticles (AuNP). In this configuration, the amount of transmitted light decreases as AuNPs accumulate on the test line, which directly correlates with the analyte concentration. This change in optical intensity results in a corresponding change in the measured OPD photocurrent. Initial quantification was obtained for 5 levels of rotavirus analyte. OLEDs and OPDs fabricated on plastic substrates were integrated within the LFIA chip to measure the intensity of line formation over a period of 30 min.

Modification of Sorghum Starch-Cellulose Bioplastic with Sorghum Stalks Filler

This study evaluated the feasibility of bioplastics production by various ratio of sorghum starch and cellulose from red seaweed Eucheuma spinossum, and the use of glycerol as plasticizer and sorghum stalks as filler. Solid-liquid matrix transition should be far over the operating temperature of gelatinization and extracted at 95oC in order to avoid the loss of conductivity. The analyzed variables were starch and cellulose seaweed Eucheuma spinossum and the addition of variation of filler. Sorghum stalk could be expected to affect the mechanical and physical properties of bioplastics. A thin sheet of plastic (plastic film) was obtained as a result that have been tested mechanically to obtain the best condition for the formulation of starch-cellulose 8.5:1.5 (g/g). From the result of morphological studies, the fillers in the mixture composites were more randomly in each product and the addition of filler can increase mechanical properties of bioplastics. Chemical modification had a major effect on the mechanical properties. The phenomena of degradation and thermoplasticization were visible at chemical changes that can be observed in FTIR spectrum test results.

A Cost-Effective Method for Repeated Slip Training Increases Recovery Rate Following Laboratory-Induced Slips

Walking is commonly promoted as a way to increase physical activity; however, walking involves an inherent risk of slips and falls. Prior research has shown that repeated exposure to slips or slip-like perturbations improves balance recovery following actual slips. Researchers have explored repeated slip training (RST) as a fall prevention intervention by repeatedly exposing subjects to slips or slip-like perturbations in a safe, controlled manner. However, current methods for RST require non-trivial financial resources. PURPOSE: To evaluate the efficacy of a cost-effective method for RST compared to no-training (NT). METHODS: Twenty-four adults (18-28 years, 12 male) were randomized to RST or NT (n=12 in each), and completed one training session and one session the following day to assess recovery rate after an actual slip. For RST, subjects repeatedly walked along a 10m walkway. During 20 randomly selected walks, a 0.9 x 0.9 m thin plastic sheet was placed at random locations along the walkway to induce a slip. The material of this sheet (e.g. polyethylene) was selected to provide low-friction with the floor and was camouflaged to match the floor surface. The NT group walked along the walkway 20 times. On the following day, vegetable oil was applied to the walkway to expose subjects in both groups to an actual unexpected slip. Balance was successfully recovered if less than 4.5% body weight, averaged over 1s periods, was applied to a safety harness worn during both sessions. Slip severity and slipping foot kinematics were measured using reflective markers on the calcanei, first metatarsal heads, and sacrum. RESULTS: Seven of 12 RST subjects recovered balance while only two of 12 NT subjects recovered (p=.045). RST subjects experienced less severe slips, with 94 cm/s slower peak slip speeds (p<.001) and 17 cm shorter slip distances (p<.001), and maintained slipping heel positions more proximal to the sacrum at heel contact (p=.019) and non-slipping foot lift-off (p=.002) and touch-down (p=.005). CONCLUSION: RST increased recovery rate by reducing slip severity and maintaining slipping heel positions more proximal to the sacrum. This cost-effective method for RST may improve its potential for adoption as a slip-and-fall prevention intervention.

Use of additive manufacturing to obtain moulds to thermoform tactile graphics for people with visual impairment

Tactile graphics with raised surfaces are used to convey information to visually impaired persons through haptic perception. For many temporary use applications, portable, easy to handle and moderately durable tactile graphics are needed and, therefore, fast, flexible and inexpensive production of small batches is required. In this paper, the feasibility of using increasingly popular rapid tooling techniques based on additive manufacturing to produce moulds to thermoform final tactile graphics is addressed. In particular, a study comparing two low cost additive manufacturing techniques, usually used for final part rapid prototyping and not for rapid tooling, 3D Printing and Fused Deposition Modelling, is shown and discussed. Geometrical reproduction of the moulds and their suitability for very thin plastic sheet thermoforming of tactile graphics is analysed. The study reveals that these techniques are technically feasible and, furthermore, costs are low in comparison to conventional techniques used to produce thermoforming moulds.

The Effect of Plastic Mulch on Growth and Yield of Rain-fed Cowpea and Watermelon in North Kordofan State of Sudan

A research was carried to identify the effect of plastic mulch on growth and yield of water melon (citrullus lanatus) and cowpea ((Vigna unguiculata L.Walp).), two popular crops extensively grown in Western Sudan under rain-fed condition. The experiment was conducted during rainy seasons (2014/15-2016/16) at two locations in North Kordofan of Sudan, consisted of two treatments (covered or uncovered with thin plastic sheet) laid out in a Randomized Complete Block Design (RCBD) with four replications. Plastic sheet mulching significantly increased plant height, fruit weight, fruit number and seed yield of watermelon by 30%, 70%, 17%, and 65%, respectively. In cowpea plastic sheet mulching significantly increased number of pods per plant, grain yield and 100- seed weight by 17%, 30% and 10% respectively. It can be concluded that using plastic mulch as a soil cover increased the vegetative growth and yield of watermelon and cowpea crops under marginal sandy rain-fed conditions of North Kordofan State.

Extensive characterization of seismic laws in acoustic emissions of crumpled plastic sheets

Statistical similarities between earthquakes and other systems that emit cracking noises have been explored in diverse contexts, ranging from materials science to financial and social systems. Such analogies give promise of a unified and universal theory for describing the complex responses of those systems. There are, however, very few attempts to simultaneously characterize the most fundamental seismic laws in such systems. Here we present a complete description of the Gutenberg-Richter law, the recurrence times, Omori's law, the productivity law, and Båth's law for the acoustic emissions that occur in the relaxation process of uncrumpling thin plastic sheets. Our results show that these laws also appear in this phenomenon, but (for most cases) with different parameters from those reported for earthquakes and fracture experiments. This study thus contributes to elucidate the parallel between seismic laws and cracking noises in uncrumpling processes, revealing striking qualitative similarities but also showing that these processes display unique features.