Film Sheet Research Articles

Thin-film electrodes of dielectric elastomer-based actuators for an active vibration control system

Precision research and technological equipment, as a rule, is not able to provide its specification characteristics without a high-quality vibration protection system. Active vibration control of an object is provided with the help of an additional source of movement, an actuator. The most promising high accuracy actuators are based on smart materials, such as materials with shape memory, piezoelectric and magnetostrictive materials, electro- and magnetic active fluids and elastomers. Dielectric elastomer is one of the types of electroactive polymers. Actuators based on a dielectric elastomer show high performance in terms of accuracy and speed and operate due to the controllable deformation of the elastomer under the action of a high voltage electric field. The paper provides a comparison of actuators based on sheet and thin film control electrodes. The influence of the quality of the polymer surface and the type of electrodes on the travel range of the actuator and maximum amplitude of vibrations the system can suppress on the basis of a dielectric elastomer is estimated. The formation of the electrode by magnetron sputtering in vacuum makes it possible to create a thin-film layer of copper that covers the elastomer, despite the developed surface. The effect of ion treatment of an elastomer before coating on the quality of the formed electrode is considered. After the ion treatment, the surface of the elastomer acquires a more uniform regular structure. A thin-film electrode layer is formed according to the topology of the elastomer to an accomplished standard.

Supercapacitive Multimode Sensing with Tunable Graphene Sheet Film Electrodes

AbstractSupercapacitive multimode sensing is gaining significant attention across diverse domains, particularly within burgeoning fields of intelligent wearables and human‐computer interaction. Typically, these sensors are constructed using a matrix of conductive nanowires and soft materials such as polydimethylsiloxane (PDMS), which serve as electrodes in thin film supercapacitors (TFSs). To facilitate multimode sensing, ability to modulate response curves is crucial for practical application. In this study, we introduce porous conducting graphene sheet (GS) films with customizable thickness as TFS electrodes. We first develop a wafer‐scale fabrication method using vacuum filtration, to yield GS films with adjustable sheet resistance that can approach the percolation threshold. The use of a hydrophilic cellulose acetate (CA) filter membrane facilitates spontaneuous and nondestructive detachment of the GS film from the membrane post‐dehydration. The spontaneous separation mechanism is elucidated through time‐dependent contact angle measurements on porous films. The GS film, once separated, can be seamlessly and consistently incorporated into TFS devices as electrodes. This integration allows for multimode sensing capability with simultaneous capacitive strain sensing and ionotropic temperature sensing. The tunable nature of these porous GS films by adjusting the electrode thickness, enables fine‐tuning of the response curves for multimode sensing.

An international film dosimetry intercomparison to establish a multi-center audit framework.

In 2021, a Technical Meeting was hosted by the International Atomic Energy Agency (IAEA) where it was recommended that a standardized method for assessing the accuracy of film dose calculations should be established. To design an audit that evaluates the accuracy of film dosimetry processes. To propose a framework for identifying out-of-tolerance results and to perform an international pilot study to test the audit design. Six members of an international Dosimetry Audit Network (DAN) developed an audit for radiochromic film dosimetry. A single host center provided the materials to each participating DAN member to conduct the audits. Materials included: (1) a set of two irradiated audit films (10 Sq: 10cm × 10cm, 15 Sq: 15cm × 15cm), (2) a reference calibration film set, and (3) a blank sheet of film. The participants were blinded to the dose and tasked with producing dose maps using their standard film dosimetry process. Average Region-Of-Interest (ROI: 2cm × 2cm) dose was measured from the dose maps and compared to the known dose. In the audit, all participants used their local scanning and software protocols. Film calibration was performed in two distinct ways: (1) using a calibration film set which was provided by the host center and (2) using a calibration film set which was locally irradiated. Several variations of the audit were also performed to examine how scanning and software processing can affect film dosimetry results. In the first variation of the audit (VariantA), a set of film scans was processed using five different software solutions. In the second variation of the audit (VariantB), all films were scanned on the same scanner and processed using two in-house software solutions. Taking one film scan from each participant, the standard deviations (1σ) (SD) in the dose returned from the host calibration and returned from the local calibration were±7.2% and±6.5% respectively, with variations from -12.4% to 12.9% of the known dose. The larger dose variations in the data set were attributed to the corrections applied for variations in scanner brightness during processing and incorrectly assigned calibration doses. When the raw image data set was processed by an expert user of each software solution (VariantA) the SDs were±2.7% and±3.7% for in-house and vendor-based software, respectively. When the films were scanned on a single scanner and processed with the two in-house software solutions (VariantB) the results had a SD of±2.3%. An audit has been designed and tested for radiotherapy film dosimetry at an international level. A framework for diagnosing issues within a film dosimetry process has been proposed that could be used to audit centers that use film as a dosimeter. Incorporating quality assurance throughout the film process is important in obtaining accurate and consistent film dosimetry. A better understanding of vendor-based software systems is necessary for users to process accurate and consistent film dosimetry.

Characterization of a new low-dose and low-energy Gafchromic film LD-V1.

To characterize the dose-response, energy dependence, postexposure changes, orientation dependence, and spatial capabilities of LD-V1, a new low-dose Gafchromic film for low-energy x-ray dosimetry. A single sheet of LD-V1 Gafchromic film was cut into 15 × 20mm2 rectangles with a notch to track orientation. Eight different doses between 5 and 320mGy were delivered by an MXR-160/22 x-ray tube using x-ray beams of 90, 100, and 120kVp filtered with 3mm of Al and 2mm of Ti. The 120kVp films were scanned at 1, 1.5, 2, 3, 12, 24, 48, 72, and 168h postexposure in portrait orientation and additionally scanned in landscape orientation at 24h. The 90 and 100kVp films were scanned at 24h postexposure in portrait orientation. Lastly, a 20 × 200mm2 strip of film was irradiated using a thin-slit imaging collimator and scanned 24h postexposure to test the film performance in an x-ray imaging application. Of the three color channels, the red channel was found to produce a dose-response curve with a large range of net optical density (netOD) values across the considered dose range. A prominent energy dependence was discovered, resulting in dose discrepancies on the scale of 17mGy between 90 and 120kVp for a dose of 80mGy. The measured postexposure changes suggest that the calibration irradiation-to-scan time should be longer than 12h with a±4h scanning time window for dose errors of<0.5%. An average dose difference of 3.4% was found between the two scanning orientations. Lastly, noise of 4% was measured in the thin slit collimator film for a dose of 30mGy. We have characterized the LD-V1 film for low-energy, low-dose x-ray dosimetry. Energy, scan-time, and orientation dependencies should be considered when using this film.

Multi-Criteria Decision-Making for Selecting Solar Window Film Sheets for Energy Saving in Buildings

Recently, there have been several advancements in the field of sustainable energy solutions, particularly in the selection of solar window film sheets. In this research, a multi-criteria decision-making approach was applied to compare three different types of window film sheets, Silver 35, TrueVue 15, and Sterling 40, to aid in selecting the most suitable window film based on the United Arab Emirates market. The primary aim of this work is to provide decision-makers with a structured approach to enhance their choices for selecting window film sheets. The methodology employed involves evaluating various criteria, including visible light transmittance, solar energy rejected, energy transmittance, energy absorptance, cost, glare reduction, visible light reflectance interior, and fade reduction. These criteria are assessed using the Analytic Hierarchy Process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The results demonstrate that Sterling 40 is the best choice followed by Silver 35. Based on the final TOPSIS results, the difference between the scores of these two window film sheets was not significant, while they were far from the score of TrueVue 15.

Design and Realization of Visual and Contact-Type Fast Charging Power Source.

Charging power supplies with both fast and visualization functions have a wide range of applications in the information and new energy industries. In this paper, the visualized and contact-type fast charging power supply based on WO3 film and Zn sheet is presented, and the prototype devices are fabricated. Different with the charging method of conventional batteries, charging is achieved by a Zn sheet contacting with a WO3 film moistened with water, resulting in a rapid discoloration of WO3. Theoretical investigation indicates that the interaction between Zn sheet and water molecules is the primary cause of the color change in the WO3 film. The WO3 film completes the colouring state within 10 s in the presence of Zn sheet and water, and the open-circuit voltage of the device is 0.7 V, which can be used to drive various electronics by series-parallel connection. This research introduces a novel method to induce colouring of WO3 films and proposes a fast charging mode different from traditional power sources. It provides valuable insights for the future development of fast charging in the field of electrical energy.

Layered magnesium vanadate film electrodes as high-performance cathode materials for thin-film non-aqueous zinc-ion batteries

Thin-film non-aqueous zinc-ion batteries (ZIBs) are recognized as an alternative energy storage technology with large-scale application prospects. The use of organic electrolytes with a wide window of electrochemical stability to construct non-aqueous ZIBs results in high operating voltage and energy density. In this paper, magnesium vanadate (Mg0.01V2O5) films were in situ grown and annealed on indium tin oxide (ITO) conductive glass using low-temperature liquid-phase deposition, and directly assembled into thin-film ZIBs. The battery achieved a stable capacity of 137.5 mA h m−2 after 80 cycles at 167 mA m−2. In addition, it exhibited an initial capacity of 104.1 mA h m−2 at 250 mA m−2 and a capacity retention of 75.6 % after 200 cycles. Good rate performance feedback was also obtained. According to X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), the electrochemical reaction process of the Mg0.01V2O5 film electrode was analyzed and the insertion/extraction mechanism of Zn2+ was investigated. Due to the instability of the V2O5 structure, the pre-inserted layer of Mg2+ plays a role as a pillar between layers during preparation, supporting the vanadium–oxygen layer and improving structural stability and battery life. At the same time, thin-film ZIB directly composed of film, diaphragm, electrolyte and zinc sheet has good diffusion dynamics, simplicity and size controllability, making it more suitable for commercial applications. Therefore, the thin-film non-aqueous ZIBs in this work may provide new ideas for mobile novel micro power sources.

Preparation and electrochromism of amorphous Bi-doped TiO2 film for aqueous-based electrochromic device

Amorphous Bi–TiO2 films with improved electrochromic properties have been successfully fabricated by a facile sol-gel spin-coating technology. The influence of dopant bismuth (Bi) content and sol amount on the electrochromic performance of Bi–TiO2 films was studied. The optimized Bi–TiO2 films show outstanding electrochromic properties, including wide transmittance modulation (ΔT = 74.26 % at 640 nm), short switching times (2.6 s/3 s for bleaching and coloring), and large coloration efficiency (52.77 cm2 C−1). A proton-based electrochromic device was prepared by the amorphous Bi–TiO2 film as the electrochromic film and Cu sheet as the counter electrode. The prepared device has a small operating potential range (1.0 V) in aqueous electrolyte due to the excellent electrochromic performance and high proton activity for the amorphous Bi–TiO2 film. In addition, the device shows excellent performance (ΔT = 67.41 %, 2.5 s/3.9 s for bleaching and coloring), providing an important reference value for the development of high-efficiency electrochromic device.

Preliminary Study Effect of by-products of Biodiesel Glycerol in Increasing the Elasticity of Film sheets for Seaweed Derivative-Based Soft Capsules

Abstract Glycerol is a by-product in the production of biodiesel that has the potential to be used as a material for making films for soft capsules. This study aims to determine the effect of glycerin on the elasticity of film sheets for soft capsules. The method used is the determination of glycerin concentration based on trial and error, film solution preparation by casting technology, and physical testing of the sheet including tensile strength, elasticity, tackiness, and viscosity. The results showed that the best concentration in the manufacture of film for soft capsules was 15 % with a tensile strength of 2.3 MPa, elasticity of 3.4 MPa, and stickiness of 1500 gf. The appearance of the resulting film sheet is very clear and slightly elastic. The addition of glycerol can improve the quality of film sheets for soft capsules

A study on the fabrication procedure for a high-D/Ti-ratio-deuterated-titanium film on the disk-type neutron generator target

This study aims to present thin film deposition and deuterium adsorption procedure to fabricate disk-type targets with high D/Ti values for a neutron generator and increase their lifespan. The neutron target consists of a titanium thin film with hydrogen loading, and a copper substrate for heat removal. We optimized the incident deuterium ion beam energy and thin film thickness using Geant4 simulations. Additionally, we calculated the expected neutron yield under the optimized conditions. The hydrogen adsorption conditions were optimized by comparing the H/Ti results as per hydrogen adsorption temperature and loading time using titanium foils of different thickness values. Hydrogen (or deuterium) adsorption ratio is strongly influenced by the surface condition and the deposition conditions of the thin film. A titanium film was deposited in various conditions of plasma DC power and substrate temperature. The quality of the thin film was evaluated through surface roughness evaluation and thin film sheet resistance for each deposition conditions. Subsequently, the hydrogen adsorption results were compared according to the quality of the thin titanium films, and the thin titanium film deposition conditions with the highest hydrogen adsorption ratio were confirmed. The selected conditions were applied to conduct deuterium adsorption. In conclusion, this study underscores the critical relationship between thin film quality and hydrogen (or deuterium) adsorption ratio, reinforcing the importance of optimizing thin film deposition parameters for the design of neutron generator disk-type targets with high quality of film and extended lifespan.

Laser deposited ultra-thin silver nanoparticles on CMC-PVA blend film as sheet for wound dressings

In this study, silver nanoparticles (AgNPs) were synthesized using pulsed laser deposition and deposited on a sheet film composed of Carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and AgNPs. These polymeric-based nano-composites were investigated for their potential application in wound healing. The structural properties of the composites were examined using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Morphological features were observed through field emission scanning electron microscopy (FESEM), and roughness characteristics were studied using FESEM micrographs. The CMC-PVA-AgNPs scaffolds with deposition times of 10 and 12.5 min showed minimal deviations in surface structure compared to the composites with longer deposition times, where scattered AgNPs and aggregates were observed. Furthermore, the roughness parameter (Ra) values indicated the potential of silver NPs in creating trapping sites and crystal defects, as evidenced by an increase in Ra from 18.96 nm in the pure CMC-PVA blend to 34.17 nm at a deposition time of 20 min. The optical properties of the composites were investigated by determining the band-gap of direct and indirect transition modes, which exhibited a decreasing trend. The presence of silver NPs was confirmed by the plasmon absorption band observed around 400 nm. The intensity of the plasmon peaks increased with longer laser deposition times, indicating an increase in the silver content over time. Finally, the antibacterial activity of the prepared scaffolds against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Micrococcusluteus was evaluated, and the results strongly support the potential of the prepared material for biological applications. In conclusion, the synthesized CMC-PVA-AgNPs nano-composites deposited using pulsed laser deposition technique exhibited promising properties for wound healing applications. The comprehensive characterization of the composites, including their structural, morphological, optical, and antibacterial properties, provides valuable insights for further research and development in the field of biomaterials.

The Influence of TiO2-Lignin Hybrid Fillers in Low-Density Polyethylene Composites on Photocatalytic Performance and UV-Barrier Properties.

The main objective of this study was to discover new packaging materials that could integrate one of the most expected properties, such as UV protection, with a self-cleaning ability defined as photocatalytic performance. Accordingly, new hybrid additives were used to transform LDPE films into materials with complex performance properties. In this study, titanium dioxide-lignin (TL) hybrid systems with a weight ratio of inorganic to organic precursors of 5-1, 1-1, and 1-5 were prepared using a mechanical method. The obtained materials and pristine components were characterized using measurement techniques and research methods, such as Fourier-transform infrared spectroscopy (FTIR), thermal stability analysis (TGA/DTG), measurement of the electrokinetic potential as a function of pH, scanning electron microscopy (SEM), and particle size distribution measurement. It was found that hydrogen bonds were formed between the organic and inorganic components, based on which the obtained systems were classified as class I hybrid materials. In the next step, inorganic-organic hybrid systems and pristine components were used as fillers for a low-density polyethylene (LDPE) composite, 5 and 10% by weight, in order to determine their impact on parameters such as tensile elongation at break. Polymer composites containing titanium dioxide in their matrix were then subjected to a test of photocatalytic properties, based on which it was found that all materials with TiO2 in their structure exhibit photocatalytic properties, whereby the best results were obtained for samples containing the TiO2-lignin hybrid system (1-1). The mechanical tests showed that the thin sheet films had a strong anisotropy due to chill-roll extrusion, ranging from 1.98 to 3.32. UV-Vis spectroscopy revealed four times higher light absorption for composites in which lignin was present than for pure LDPE, in the 250-450 nm range. On the other hand, the temperature at 5% and 30% weight loss revealed by TGA testing increased the highest performance for LDPE/TiO2 materials (by 20.4 °C and 8.7 °C, respectively).

The Development of a Composite Thin Film Barrier of Tungsten Fe3O4-rGO (FerGO) for the Radiation Shielding of Medical Personnel.

Tungsten is the most effective eco-friendly material used for radiation shielding in hospitals. However, despite its commendable density and shielding performance, tungsten faces challenges in miscibility with other materials because of its elevated melting point and strength. In this study, to protect medical personnel against scattered rays, which are indirect X-rays, a lightweight material was prepared by mixing graphite oxide material, considering its thinness and flexibility. Tungsten particles were evenly dispersed in the polymer, and nanofibers were prepared using this blended polymer solution via electrospinning. Concurrently, the process technology was explored to craft a thin film sheet and obtain a lead-like shielding effect. A spinning solution was prepared by mixing Fe3O4-rGO (FerGO) and tungsten. At 60 kVp, 0.1 mm was measured as 0.097 mmPb, at 80 kVp, 0.2 mm was measured as 0.196 mmPb, and at 100 kVp, 0.3 mm was measured as 0.279 mmPb, showing similar shielding performance to lead. As density directly affects the shielding effect, graphene oxide played an important role in increasing the density of the material from 1.941 g/cm3 to 2.302 g/cm3. Thus, this study provides an effective process for producing thin film sheets equivalent to lead.

Study of the dependence of relative elongation on mechanical stress of polyvinyl chloride films

The dependence of relative elongation on mechanical stress in polyvinyl chloride samples of various widths and working lengths was experimentally studied. The purpose of the study was to study the dependence of deformation on mechanical stress of polyvinyl chloride films of various sizes (width and length). The scientific and practical significance of the work lies in the fact that the data can serve as the basis for future research. Polyvinyl chloride film with a thickness of 100 microns was chosen as the material under study. The film sheets were cut into strips 3, 5, 7, 10 mm wide using a special cutting device with adjustable sample cutting width and length. The working length of the samples was: 4, 5, 6, 7, 8 cm. The tests were carried out on a special tensile testing machine RU-50. This setup is designed to study the dependence of strain (relative elongation) ε on stress σ. Significant changes in the mechanical properties of the material were discovered depending on various geometric parameters. The data obtained are satisfactorily described by the authors' models. The value of this study lies in the fact that the results of the work, according to the authors, will serve as an incentive to improve the mechanical properties of the research object.

Influence of Bulk Defect Density on the Efficiency of CIGS Based Photovoltaic Cell/Solar Cell

In CIGS-based thin-films, bulk defects are believed to represent disturbances either in a regular, periodical arrangement within the atoms or within the crystalline media which influence sheet resistivity. In this study, first a resistivity measurements were carried out on CIGS thin films using the Van Der Pauw technique. Then, a comparison between two Van Der Pauw four-point measurement configurations (aligned and square) were done which showed that the square configuration was the most appropriate configuration that can be recommended to measure thin film sheet resistance of CIGS films. Finally, a numerical simulation using SCAPS-1D software was used to study the influence of bulk defect density in a CIGS films as an absorber layer in a model photocell. Using the simulated data, three operating zones for the model photocell were identified depending based on the concentration of its bulk defect density. The influence of bulk defects on thickness, band gap and doping were then analyzed. It was revealed that when the bulk defect density was less than 5×1013 cm-3 for an absorber of thickness in the order of over 3 μm, a band gap between 1.3 eV-1.4 eV and acceptor density of 1016 cm-3were the optimal operating conditions for the model photocell. It was concluded that the CICS layer used as an absorber can be improved if its bulk defect density is tuned to optimal levels.

Detachable artificial micro-structured silicon chip for reconfigurable acoustofluidic particle manipulation

The utilization of reconfigurable acoustofluidic manipulation facilitates diverse and complex modes of particle patterning. Traditional approaches employ a variety of advanced acoustic transducers and equipment configurations to modify the acoustic field, which is challenging for disposable, portable, and cost-effective biomedical applications. For the first time, we demonstrate the feasibility of using an artificial micro-structured waveguide silicon chip to generate a variety of unique modes of the acoustic field for reconfigurable and versatile particle manipulation. The distribution of acoustic field for eleven different designs of artificial micro-hole structures and bare surfaces was simulated and subsequently fabricated using laser-cut techniques for acoustofluidic demonstration. The impact of using Polydimethylsiloxane (PDMS) film and glass sheet as the sealing layer on the particle pattern shape and moving velocity was characterized. It was observed that by adjusting the excitation frequency and microchamber size, the modes of the particle pattern were changed, thereby demonstrating the remarkable flexibility of particle reconfiguration. The investigation of thermal effect quantification validates the possibility of long-term operation while maintaining a high level of biocompatibility. Additionally, the plug-and-play assembly mode enables the elimination of microfluidic components to prevent the occurrence of cross-contamination. Such reconfigurable acoustofluidic manipulation platforms have the potential to serve as sample treatment tools in chemical and biomedical instruments.

A new electrostatic dust removal method using carbon nanotubes transparent conductive film for sustainable operation of solar photovoltaic panels

Electrostatic dust removal has the advantages of energy saving, high efficiency, and controllability, and has become the preferred dust removal solution for solar photovoltaic (PV) panels in recent years. This paper investigates a new electrostatic adsorption dust removal method for solar PV panels based on the electrostatic dust removal effect of carbon nanotubes (CNTs) transparent conductive films. In the sheet resistance range of 500–1×105 Ω/□, the electrostatic dust removal effect of CNTs transparent conductive films has little relationship with the film sheet resistance, and when the electric field strength in the dust removal area is 6 kV/cm, the final dust removal rate of different films can reach more than 98.6 %, and the power generation efficiency of the PV panels can reach 94–97 % of that of the ordinary PV panels in the surface clean state after dust removal. The influence of the environment on the dust removal effect is mainly reflected in the relative humidity. When the relative humidity of the dust removal environment is 70 %, it shows the optimal dust removal effect, and the electric field strength required for the dust particles to jump is the lowest, which is 2.46 kV/cm. The highest dust removal efficiency can be achieved by using a metal plate with a lower surface curvature of 1/9.08 cm−1, and the final dust removal rate can reach 98.92 %. The research results are of great significance for further developing electrostatic dust removal technology in the solar PV panel dust removal field.

Dose-rate dependence and IMRT QA suitability of EBT3 radiochromic films for pulse reduced dose-rate radiotherapy (PRDR) dosimetry.

Pulsed reduced dose rate (PRDR) is an emerging radiotherapy technique for recurrent diseases. It is pertinent that the linac beam characteristics are evaluated for PRDR dose rates and a suitable dosimeter is employed for IMRT QA. This study sought to investigate the pulse characteristics of a 6 MV photon beam during PRDR irradiations on a commercial linac. The feasibility of using EBT3 radiochromic film for use in IMRT QA was also investigated by comparing its response to a commercial diode array phantom. A plastic scintillator detector was employed to measure the photon pulse characteristics across nominal repetition rates (NRRs) in the 5-600 MU/min range. Film was irradiated with dose rates in the 0.033-4Gy/min range to study the dose rate dependence. Five clinical PRDR treatment plans were selected for IMRT QA with the Delta4 phantom and EBT3 film sheets. The planned and measured dose were compared using gamma analysis with a criterion of 3%/3mm. EBT3 film QA was performed using a cumulative technique and a weighting factor technique. Negligible differences were observed in the pulse width and height data between the investigated NRRs. The pulse width was measured to be 3.15±0.01 and the PRF was calculated to be 3-357Hz for the 5-600 MU/min NRRs. The EBT3 film was found to be dose rate independent within 3%. The gamma pass rates (GPRs) were above 99% and 90% for the Delta4 phantom and the EBT3 film using the cumulative QA method, respectively. GPRs as low as 80% were noted for the weighting factor EBT3 QA method. Altering the NRRs changes the mean dose rate while the instantaneous dose rate remains constant. The EBT3 film was found to be suitable for PRDR dosimetry and IMRT QA with minimal dose rate dependence.

Dose profile evaluation for small fields of a LINAC 6 MV beam using a solid water phantom

Radiotherapy is basically used in oncology and consists of the use of ionizing radiation to stop neoplastic cells from reproducing or to kill cells. Radiotherapy is one of the three main modalities of treatment for malignant diseases such as cancer, the other two are chemotherapy and radiosurgery. Unlike other medical specialties that rely primarily on the clinical knowledge and experience of specialist physicians, radiotherapy relies heavily on modern technology and the collaborative effort of several professionals whose coordinated team approach greatly influences the outcome of treatment. Linear accelerators with jaw or multileaf (MLC) field colimators are used to irradiate patients undergoing therapy and use fields with dimensions ranging from 4×4 to 40×40 cm². However, looking for the delivery of prescribed doses increasingly conforming to the target volume, small field beam openings are being used in advanced photon beam radiotherapy. In this work, the absorbed dose distribution of an X-ray beam was recorded using a solid water phantom. This phantom was irradiated using small fields with 1×1, 2×2, 3×3 and 5×5 cm². The 6 MV X-ray beam was generated on a Synergy Platform model linear accelerator from the manufacturer Elekta, and sheets of radiochromic film were used to record the dose profiles within the phantom. The solid water phantom loaded with radiochromic film was positioned 1.0 m away from the focus of the X-ray beam. The longitudinal profile of absorbed dose obtained showed the maximum dose value at 1.26 cm (peak) depth inside the phantom. The smaller field size (1×1) generated a smaller maximum absorbed dose (peak). Axial dose profiles were recorded at 1 cm depth and showed a plateau in the central region of the field. The mean absorbed dose at the plateau measured at 1 cm depth ranged from 98% to 90% of the maximum dose for the 5x5 and 1x1 cm² fields, respectively. The experiments performed showed a variations in the absorbed dose values due to the size of the fields. These variations occurred as in the amplitude of peak value in the depth profile as in the axial plane of distribution.

Study on Improving the Energy Efficiency of a Building: Utilization of Daylight through Solar Film Sheets

Daylight can contribute to substantial reductions in the energy consumed by artificial lighting applications. However, issues such as visual comfort, illumination intensity, and availability represent major issues when daylight is relied upon to illuminate buildings. There are many technologies that are used to control received sunlight and minimize its side effects. The placement of solar film sheets on window glass is a common and popular method utilized in many buildings to minimize electric lighting energy consumption without causing undue visual discomfort to occupants. To examine the practicality of this application and its effect on room lighting, a modern office was selected in which to conduct this field study. Two measures were used to evaluate this technique: firstly, field measurements and their comparison to the specified standard illumination levels; and secondly, a short-form questionnaire survey conducted to obtain occupants’ opinions of the office lighting. Actual measurements were conducted in the selected office spaces, with and without applying solar control film coating on the window glass. Indoor luminance levels and lighting comfort were systematically recorded and analyzed. The findings of this study show that using a solar film with a visible light transmittance of 50% can achieve savings in energy consumption of up to 33% if utilized as part of an integrated lighting system.