Mylar Film Research Articles

Design, characterization, and fabrication of solar-retroreflective cool-wall materials

Raising urban albedo increases the fraction of incident sunlight returned to outer space, cooling cities and their buildings. We evaluated the angular distribution of solar radiation incident on exterior walls in 17 U S. climates to develop performance parameters for solar-retroreflective walls, then applied first-principle physics and ray-tracing simulations to explore designs. Our analysis indicates that retroreflective walls must function at large incidence angles to reflect a substantial portion of summer sunlight, and that this will be difficult to attain with materials that rely on total internal reflection.Gonio-spectrophotometer measurements of the solar spectral bi-directional reflectivity of a bicycle reflector showed little to no retroreflection at large incidence angles. Visual comparisons of retroreflection to specular first-surface reflection for four different retroreflective safety films using violet and green lasers suggest their retroreflection to be no greater than 0.09 at incidence angles up to 45°, and no greater than 0.30 at incidence angles of up to 70°.Attempts to produce a two-surface retroreflector with orthogonal mirror grooves by cutting and polishing an aluminum block indicate that residual surface roughness impedes retroreflection. Ongoing efforts focus on forming orthogonal surfaces with aluminized Mylar film, a material with very high specular reflectance across the solar spectrum. We investigated (1) folding or stamping a free film; (2) adhering the film to a pre-shaped substrate; or (3) attaching the film to a flat ductile substrate, then shaping. The latter two methods were more successful but yielded imperfect right angles.

Foil liner implosions with a nanosecond rise time of current through the liner

The paper presents the results of experiments on the implosion of cylindrical liners made of aluminum foil and mylar film with a deposited layer of aluminum. To reduce the rise time of current through a liner to several nanoseconds (1–3 ns), a low-density plasma was injected into the liner area. The experiments were carried out on the MIG generator at a current level through the liner of about 2 MA. A liner with a diameter of 1.8 mm, made of aluminum-deposited 2.5-μm thick mylar film, implodes in 11 ns and has a final velocity of 2×107 cm·s−1. The radius of pinched plasma is about 80–100 μm, which corresponds to a 20-fold radial convergence of the liner.

Charged particle radiobiology beamline using tandem accelerator-based MeV protons and carbon ions: a pilot study on the track-end radiation quality, variable biological effectiveness and Bayesian beam dosimetry

For in vitro cell irradiation using tandem accelerator-based MeV protons and carbon ions, by TOPAS simulation, a pilot study of performance evaluation is presented on a collimation beamline for 3 MeV protons and 10 MeV carbon ions from a 2 × 3 MV tandem accelerator. Based on the elements and source parameters, a collimated beam of 2.8 MeV protons or 2.5 MeV carbon ions, with 5.175 mm or 5.166 mm full width tenth maximum (FWTM), respectively, can be delivered to the target cell dish. TOPAS simulations and/or deterministic algorithms present a Bragg curve of linear energy transfer (LET) (10–70 keV μm−1) along a 138 μm range of the proton beam, and a declining LET of the carbon beam (900–100 keV μm−1) within 4 μm range. Based on the biophysical models for relative biological effectiveness (RBE) of protons, TOPAS RBE scorers presents a set of depth-variation curves of the proton RBE (for V79 and DU145 cells), linearly related to the Bragg curve of the proton LET. Based on the microdosimetric-kinetic (MK) theory, in the 4 μm range for a monolayer cell thickness, the mean RBEα (V79 cells) of the carbon ion beam is estimated as 3.612 (late S phase) and 1.737 (G1/S phase) for the mean LET of 492 keV μm−1. For practical irradiations, a tunable proton RBE can be acquired by changing the thickness of the cell dish. For the low-energy high-fluence (rate) beams, indirect beam measurements are proposed to detect the proton-beam induced scattering/recoil protons from a beam-intercepting Mylar film, and the carbon-beam induced backscattered electrons from a gold-deposited Havar-foil beam window. Statistical dosimetry for the indirect measurement is established, using a Bayesian model based on the preset number of detection counts, by which the mean value of the whole-dish dose can be prescribed and the uncertainty introduced in the survival data can be corrected.

The Optimal Distance of the Electrode to the Lifting Film Surface when Lifting Dust Footwear Impressions Using an Electrostatic Dust Print Lifter.

Footwear impressions are one of the valuable physical evidence encountered at crime scenes and its identification can facilitate narrowing down the suspects and establishing the identity of the criminals. The technique of electrostatic lifting (ESL) dust shoeprints at crime scenes is well established with scenes of crime examiners. And in the procedure, the recovery of the original item containing the impression should be made as good as it can and not damage the marks. In this study, the different particle sizes of SiO2 were used to simulate dust and light soil residues, comparing different particle sizes and electrode positions were used to compare the adsorption ability on the surface of electrostatic lifting film in high-voltage electrostatic field for the collection of shoeprints. The results indicated that lifting film in electrostatic field will be pressed down to the dust surface, the compaction and electrostatic adsorption force will vary with the distance between the high-voltage electrode and film surface. Reducing the distance can increase the electric field strength near the lifting film, and the adsorption capacity of Mylar aluminum-plating film to dusts can be improved significantly. Adsorption capacity of the lifting film was related to the size of dust particles and significantly improved with the increase of the particle charge. The optimum distance which can get the best adsorption capacity between the electrode and film surface is from 10 to 15mm.

Study of the influence of the electron irradiation dose on the deformation of mylar films taking into account the processes of destruction and crosslinking

Experimental studies of the dependence of the deformation ε on the dose of electron irradiation D taking into account the processes of destruction and crosslinking for films of the Mylar type have been carried out. It was obtained that the dependence of ε on D for the process of cross-linking is described by a linear and destruction by an exponential function.

Acoustic levitation and manipulation by a high-frequency focused ring ultrasonic transducer

Recently, acoustic levitation for non-contact micro-particle manipulation has been attracting great interest in physical, biological, and medical applications. Among the state-of-the-art manipulation technologies, single beam acoustic tweezing exhibits advantages of providing stronger trapping force and deeper penetration depth in tissues, inducing less tissue damage, and a simple configuration involving only one device. However, particle trapping by the single beam acoustic tweezer could only be operated on a smooth two-dimensional substrate, which limits the potential for real applications. Here, we report an initial attempt to acoustically levitate an individual micro-particle stably in water and manipulate the levitated micro-particle arbitrarily two-dimensionally by simply employing a 60-MHz focused ring ultrasonic transducer. The proposed working mechanism agrees well with the phenomenon. This approach could not only acoustically levitate and manipulate a micro-particle on a culture dish and on a mylar film, but could also work properly in levitating and manipulating a micro-particle placed inside the polyimide tube. This simple and low-cost approach is extremely useful for effective non-contact micro-particle manipulation without having critical concerns on the substrate properties.

Characterization of a Piezoelectric Inkjet Aerosol Generator for the Study of Bioaerosol Survivability

ABSTRACT In laboratory-based bioaerosol researches, the ability to reliably generate bioaerosols with minimal damage to the microorganisms is critical. In this work, a thermally consistent inkjet-based aerosol generation technique was adopted to generate bioaerosols, and its ability to preserve microbial survivability was assessed. The performance of the piezoelectric inkjet aerosol generator was evaluated using a potassium sodium tartrate solution and an aqueous suspension of 3-µm polystyrene latex spheres. An Aerodynamic Particle Sizer was employed to measure the aerosol number concentration and the size distribution. The main operating parameters of the inkjet print head for generating viable aerosols were the driving voltage, pulse duration, dispersion air flow, pulse frequency, and volume fraction of the solids in the nebulizing liquid. In the bioaerosol survivability experiments, yeast was used as the test microorganism. The nebulized yeast cells were sampled at different distances from the outlet of the inkjet aerosol generator and thus exposed to varying degrees of relative humidity for different residence times. Three bioaerosol samplers, namely, a BioSampler, a gelatin filter cassette, and a Marple cascade impactor with Mylar film, were used to collect the airborne yeast samples. Yeast survivability was determined by methylene blue viability staining. This study successfully demonstrated the feasibility and the advantages of using a piezoelectric inkjet print head to generate viable aerosols. Applying a square wave with appropriate combinations of voltage and pulse duration enabled the inkjet system to produce a liquid with rheological properties similar to those of water, and the particle generation rate was manipulated by adjusting the pulse frequency. Moreover, dispersion air was required to reduce coagulation. Although the number of droplets containing PSL spheres increased with the volume fraction of the spheres (Fv), a high Fv also reduced the probability of singlets forming.

DEFORMATION DEPENDENCE OF POLYMER MATERIALS ON THE DOSE OF ELECTRONIC RADIATION

In this paper we consider the effect of high-energy electron irradiation, load and temperature on the mechanical properties of Mylar films. The simplest physical model is developed. Studies have shown that with an increase in the dose of electron irradiation to 104 Gy, there is a slow decrease in deformation for Mylar, and a further increase to 106 Gy leads to a sharp decrease in it. At the same time, with increasing temperature, the relative elongation increases by more than 50 %, associated with the growth of destructive processes in the material. The dependences of strain and stress on the dose of electron irradiation are described by exponential functions and are in satisfactory agreement with experimental data.

Tracking Chambers Made of Mylar Drift Tubes for Experiments at the Accelerator Complex of the National Research Center Kurchatov Institute–IHEP

The design, procedure of assembling, and tests of drift tubes with the diameter of 30 and 15 mm made of mylar film 125 μm thick covered with aluminum from both sides are presented. The assembly technology of three-layer chambers of such tubes is described and some results showing the technical performance of the chambers are given.

Bioinspired Low-Noise Wing Design for a Two-Winged Flapping-Wing Micro Air Vehicle

This work investigates the acoustic and thrust performances of different wing designs for a two-winged flapping-wing micro air vehicle (FW-MAV). The reference wings, made of a Mylar film membrane supported by carbon-fiber rods, produce a perceived overall noise of about 68.8 dBA when operating at the flapping frequency of 10 Hz typically required for flying such a flapping wing vehicle. This noise is much higher than the value of the environmental background. Wings of various materials and structural configurations are designed and tested in order to reduce the flapping-wing noise. Sound and force measurements are used to assess their acoustic and lift capabilities. It is found that a wing made with a highly elastic dielectric elastomer membrane can reduce the overall perceived noise of the flapping wing by 12 dBA while slightly increasing the thrust. The mechanisms leading to this noise reduction and their potential applications in quiet FW-MAVs are discussed.

Evaluation of the Dehydration Characteristics of Ginger (Zingiber Officinale) Root Slices Using Refractance Window Drying Technology

This study investigates the drying characteristics of ginger (zingiber officinale) root slices using the Refractance Window™ drying technology. A laboratory-scale dryer was constructed by modifying a water bath. 3 mm thick ginger root slices were dried on the transparent Mylar PET plastic film that covered the bath, and the variation of the moisture content of the slices with time was determined as the drying progressed. A water temperature of 60 oC was maintained beneath the plastic film. Various drying kinetic data curves are plotted from the drying data and the thin layer model that best fits the drying data was determined. Observations indicated that the ginger root slices dried to a moisture content of 0.1g H2O/g solid on a dry basis in about 210 minutes. The regression analysis results showed that the Haghi and Ghanadzadeh thin layer model best describes the drying data for 3 mm sized slices with the coefficient of determination ( ) value of 0.9985. An effective moisture diffusivity of 8.99 x 10-8 m2/s was observed for the ginger root slices.

High-throughput in situ X-ray screening of and data collection from protein crystals at room temperature and under cryogenic conditions.

Protein crystallography has significantly advanced in recent years, with in situ data collection, in which crystals are placed in the X-ray beam within their growth medium, being a major point of focus. In situ methods eliminate the need to harvest crystals, a previously unavoidable drawback, particularly for often small membrane-protein crystals. Here, we present a protocol for the high-throughput in situ X-ray screening of and data collection from soluble and membrane-protein crystals at room temperature (20-25°C) and under cryogenic conditions. The Mylar in situ method uses Mylar-based film sandwich plates that are inexpensive, easy to make, and compatible with automated imaging, and that show very low background scattering. They support crystallization in microbatch and vapor-diffusion modes, as well as in lipidic cubic phases (LCPs). A set of 3D-printed holders for differently sized patches of Mylar sandwich films makes the method robust and versatile, allows for storage and shipping of crystals, and enables automated mounting at synchrotrons, as well as goniometer-based screening and data collection. The protocol covers preparation of in situ plates and setup of crystallization trials; 3D printing and assembly of holders; opening of plates, isolation of film patches containing crystals, and loading them onto holders; basic screening and data-collection guidelines; and unloading of holders, as well as reuse and recycling of them. In situ plates are prepared and assembled in 1 h; holders are 3D-printed and assembled in ≤90 min; and an in situ plate is opened, and a film patch containing crystals is isolated and loaded onto a holder in 5 min.

Reassessment of WD-XRF method for obsidian provenance shareable databases

The X-ray fluorescence technique using peak intensity ratios of trace elements is one of the faster, less expensive and less invasive methods for obsidian sourcing. Moreover, XRF peak intensity ratios are particularly useful when the artifact is slightly altered, particularly affecting the alkali cations, or when its surfaces are covered with a fine film of carbonate deposits formed while the sample was buried.The limitation of this technique results from the dimensions of the obsidian samples: very small obsidian samples, nowadays about 1 cm in size, are difficult to measure given the very few X-rays emitted by their surface.An aluminium holder closed with a very thin Mylar© polyester film was prepared and the specimen, positioned at the centre of the surface of the Mylar film, was placed in the XRF spectrometer. The use of recent technology XRF apparatus equipped with a 4 kW Rh anode X-ray tube coupled with an accurate measurement of refined X-ray characteristic lines, that exclude the X-ray background contribution, of five trace elements (Rb, Sr, Y, Zr, Nb), made it possible to determine the source geological outcrop of archaeological obsidian samples as little as 7 mm and as light as 40 mg.A database of peak intensity ratios, background and interference free, of five trace elements was produced for obsidian samples from Monte Arci, Palmarola, Lipari, Pantelleria, Gyali and Melos.This database may be used by other laboratories provided the X-ray intensity of the trace elements Rb, Sr, Y, Zr, Nb are measured as net intensities, that is purified from the contribution of the background and from interelemental interferences.A comparison between data obtained with two spectrometers, of different generation and differently calibrated, confirmed the possibility of obtaining a database that can be shared with other laboratories.The proposed XRF method was tested on Neolithic obsidians from four Apulian sites (Ripa Tetta at Lucera, Palestra ex G.I.L. at Foggia, Pulo di Molfetta and Grotta di Santa Barbara at Polignano a Mare), whose source outcrops had been also determined by SEM-EDS.

Inkjet-Printed Membrane for a Capacitive Acoustic Sensor: Development and Characterization Using Laser Vibrometer.

This paper describes the fabrication process and the method to determine the membrane tension and defects of an inkjet-printed circular diaphragm. The membrane tension is an important parameter to design and fabricate an acoustic sensor and resonator with the highest sensitivity and selectivity over a determined range of frequency. During this work, the diaphragms are fabricated by inkjet printing of conductive silver ink on pre-strained Mylar thin films, and the membrane tension is determined using the resonant frequency obtained from its measured surface velocity response to an acoustic excitation. The membrane is excited by an acoustic pressure generated by a loudspeaker, and its displacement (response) is acquired using a laser Doppler vibrometer (LDV). The response of the fabricated membrane demonstrates good correlation with the numerical result. However, the inkjet-printed membrane exhibits undesired peaks, which appeared to be due to defects at their boundaries as observed from the scanning mode of LDV.

Observation of soft X-ray Cherenkov radiation in Al

The soft X-ray radiation generated by 5.7 MeV electrons from both an Al foil and a Mylar film in forward direction was experimentally studied. A narrow specific directivity, an ultra-narrow spectral bandwidth and a good consistency between the experiment and theory prove that the Cherenkov radiation (CR) with photon energy near the L-edge of absorption in Al was observed. The results demonstrate that the CR spectral-angular properties and the absolute photon yield can be described well enough using Pafomov's theoretical model and Henke's refractive index database, which is essential for all practical applications.

Tracking chamber made of 15-mm mylar drift tubes

We are presenting a drift chamber composed from three layers of mylar drift tubes with outer diameter 15 mm. The pipe is made of strip of mylar film 125 micrometers thick covered with aluminium from the both sides. A strip of mylar is wrapped around the mandrel. Pipe is created by ultrasonic welding. A single drift tube is self-supported structure withstanding 350 g wire tension without supports and internal overpressure. About 400 such tubes were assembled. Design, quality control procedures of the drift tubes are described. Seven chambers were glued from these tubes of 560 mm length. Each chamber consists of 3 layers, 16 tubes per layer. Several chambers were tested with cosmic rays. Results of the tests, counting rate plateau and coordinate resolution are presented.

An Artificial Turf-Based Surrogate Surface Collector for the Direct Measurement of Atmospheric Mercury Dry Deposition.

This paper describes the development of a new artificial turf surrogate surface (ATSS) sampler for use in the measurement of mercury (Hg) dry deposition. In contrast to many existing surrogate surface designs, the ATSS utilizes a three-dimensional deposition surface that may more closely mimic the physical structure of many natural surfaces than traditional flat surrogate surface designs (water, filter, greased Mylar film). The ATSS has been designed to overcome several complicating factors that can impact the integrity of samples with other direct measurement approaches by providing a passive system which can be deployed for both short and extended periods of time (days to weeks), and is not contaminated by precipitation and/or invalidated by strong winds. Performance characteristics including collocated precision, in-field procedural and laboratory blanks were evaluated. The results of these performance evaluations included a mean collocated precision of 9%, low blanks (0.8 ng), high extraction efficiency (97%–103%), and a quantitative matrix spike recovery (100%).

Single-Phase Photo-Cross-Linkable Bioinspired Adhesive for Precise Control of Adhesion Strength.

A bioinspired, modular terpolymer adhesive, poly(N-methacryloyl-3,4-dihydroxyl-l-phenylalanine-co-9-(acryloyloxy)butyl anthracene-9-carboxylate-co-acrylic acid), has been synthesized containing three different functionalities: a photo-cross-linking segment, a wet interfacial adhesion segment, and a water-soluble segment. The synthesized adhesive polymer is the first example of a single-phase, photo-cross-linkable adhesive which does not require additional photoinitiator or other cross-linking agents. The terpolymer demonstrates strong adhesion when it swells in water and/or ethanol. The terpolymer is composed of three repeating units: N-methacryloyl-3,4-dihydroxyl-l-phenylalanine (MDOPA), which has been known to generate strong adhesion under wet conditions, poly(acrylic acid), which has been known to increase water solubility of polymers, and a photo-cross-linking segment consisting of an anthracene-based monomer used for enhancement of cohesion properties via UV irradiation (352 nm). A photomediated [4 + 4] cycloaddition reaction of anthracene results in the cross-linking of individual polymer chains after interfacial adhesion between substrates and adhesive polymers. Chemically, the covalent photo-cross-linking was confirmed by UV-vis, 1H NMR, and gel permeation chromatography (GPC). The cross-linking-fortified cohesion of the adhesive polymer network yields strengthened cohesion properties of the bulk material. The photoreaction was conveniently controlled via the duration of UV-irradiation. The adhesion properties of new adhesives were characterized by lap shear strength on transparent Mylar film and glasses after the adhesive was swollen in biologically friendly solvents including water and ethanol. The adhesion strength (J/m2) was enhanced by 850% under 352 nm UV-irradiation. Multiple application variables were tested to determine the optimal conditions, such as solvent, concentration, polymer composition, and substrate. The best adhesion properties were obtained from a 1:1 weight ratio of polymer:solvent in water on a Mylar film surface. As a single-phase system, the synthesized terpolymer is very convenient to use, and its adhesion strength can be easily modified by UV light. Additionally, the terpolymer's high water compatibility makes it ideally suited for application in the biomedical field.

가항력돛을 이용한 궤도이탈장치 개발

본 논문에서는 가항력돛을 이용한 궤도이탈 장치를 설계 및 제작하고 전개 특성을 연구하였다. 형상기억합금을 이용한 분리장치를 개발하고, 형상기억합금의 구동에 따라 테잎 스프링의 복원력을 이용해 구동되는 새로운 궤도이탈 장치를 설계하고 실험하였다. 가항력돛의 효율적인 수납 및 전개를 위해 origami flasher 방식 중 original ISO flasher 방식을 선정하였으며, 반복적인 실험을 하기 위해서 다른 재료들에 비해 저렴한 우주재료인 mylar film을 가항력돛의 재료로 사용하였다. 또한, 일회성 장치 신뢰성 평가 방법 중 하나인 FTA(fault tree analysis) 방법을 통해 장치의 신뢰도(0.997572)를 평가하고 가장 치명도가 높은 부분이 Roller failure임을 확인하였다. 최종적으로 가항력돛의 전개장치의 제작 및 실험을 통하여 향후 궤도이탈 장치의 개발 가능성을 확인하였다. In this paper, we design and fabricate a de-orbiter using drag-sail and evaluate deployment characteristics. Without employing an actuator to deploy, the de-orbiter is activated by the SMA wire based the release mechanism and driven by the restoring force of the tape-spring. For efficient storage and deployment of drag-sail, an origami method of original ISO flasher is chosen and low priced mylar film is used as the material of the drag-sail. In addition, through the fault tree analysis method which is one of the one-shot device reliability evaluation methods, we confirm the reliability of the de-orbiter(0.997572) and the Roller failure has the highest criticality. Finally, we find feasibility of the proposed de-orbiter through the deployment demonstration of drag-sail.

Channelled spectrum method for birefringence dispersion measurement of anisotropic Mylar film

A convenient and accurate interferometric technique for measuring the birefringence dispersion of anisotropic Mylar film according to a continuous spectral range of wavelengths in the ultraviolet, visible and near infrared region, using the so called “Channelled Spectrum” method is described. The technique proposed here consists of considering all the experimental data, not only the minima of the transmitted light obtained after recording the transmitted light that travelled a Mylar film sandwiched between two crossed polarizers. Furthermore, we are able to measure the transmission coefficients of the polarizers, the absorption of the Mylar sheet, and other parameters involved in the experiment by using a spectroscopic detection. Thus, the transmission of the Mylar sheet vs wavelength is deduced. Using the dispersion of the optical birefringence given by the birefringence dispersion theory for uniaxial organic compounds ie the one band, three-band, and Cauchy models, and by applying a nonlinear fitting procedure on the recorded experimental data, we have obtained the parameters involved in the expressions of the optical birefringence and we have computed the optical birefringence of the Mylar film vs wavelengths. In the visible and near-infrared regions, all models give excellent fits to the experimental data. In the UV region, the three-band model considers the resonance effect. Thus, in the near-resonance region the results from the three-band model are more accurate.