Irradiated Part Research Articles

Effects of UV light on physicochemical changes in thermoplastic polyurethanes: Mechanism and disinfection byproduct formation

The presence of microplastics (MPs) products and particles in the environment can significantly impact the human body. Most MPs that enter the environment also enter the water cycle. During sunlight light irradiation (especially ultraviolet (UV) part) or UV disinfection, many of these MPs, particularly those rich in surface functional groups like thermoplastic polyurethanes (TPU), undergo physicochemical changes that can affect the formation of disinfection byproducts (DBPs). This study investigates the physicochemical changes of TPU in water after exposure to UV irradiation and incubation in the dark, as well as the formation of DBPs after chlorination. The results show that TPU undergo chain breakage, oxidation, and cross-linking when exposed to UV irradiation in an aqueous system. This leads to fragmentation into smaller particles, which facilitates the synthesis of DBPs. Subsequent research has demonstrated that the TPU leaching solution produces a significantly higher DBP content than the chlorination of TPU MPs, particularly at high concentrations of CHCl3. Therefore, it is important to give greater consideration to the soluble DBP precursors released by TPU.

Measuring DNI with a New Radiometer Based on an Optical Fiber and Photodiode.

A new cost-effective radiometer has been designed, built, and tested to measure direct normal solar irradiance (DNI). The proposed instrument for solar irradiance measurement is based on an optical fiber as the light beam collector, a semiconductor photodiode to measure the optical power, and a calibration algorithm to convert the optical power into solar irradiance. The proposed radiometer offers the advantage of separating the measurement point, where the optical fiber collects the solar irradiation, from the place where the optical power is measured. A calibration factor is mandatory because the semiconductor photodiode is only spectrally responsive to a limited part of the spectral irradiance. Experimental tests have been conducted under different conditions to evaluate the performance of the proposed device. The measurements confirm that the proposed instrument performs similarly to the expensive high-accuracy pyrheliometer used as a reference.

Effects of Partial-Body, Continuous/Pulse Irradiation at Dose Rates from FLASH to Conventional Rates on the Level of Surviving Blood Lymphocytes: Modeling Approach. I. Continuous Irradiation.

A mathematical model developed by Cucinotta and Smirnova is extended to describe effects of continuous, partial-body irradiation at high doses D and at dose rates N from FLASH to conventional rates on the level of surviving blood lymphocytes in humans and small laboratory animals (mice). Specifically, whereas the applicability of the model is limited to the exposure times shorter than a single cardiac cycle T0, the extended model is capable of describing such effects for the aforementioned and longer exposure times. The extended model is implemented as the algebraic equations. It predicts that the level of surviving blood lymphocytes in humans and mice increases with increasing the dose rate from N= D/T0 to FLASH rates and approaches the upper limiting level of 1-vR, where vR is the fraction of blood volume in the irradiated part of the blood circulatory system. Levels of surviving blood lymphocytes computed at doses from 10 Gy to 40 Gy and at dose rates N, which equal or exceed 40 Gy/s for humans and 400 Gy/s for mice, are nearly indistinguishable from the upper limiting level. In turn, the level of surviving blood lymphocytes in humans and mice decreases with decreasing the dose rate from N= D/T0 to conventional rates and approaches a lower limiting level. This level strongly depends on the dose D (it is smaller at larger values of D) with a slight dependence on the dose rate N. The model with the parameters specified for mice (together with the model of the dynamics of lymphopoietic system in mice after partial-body irradiation) reproduce, on a quantitative level, the experimental data, according to which the concentration of blood lymphocytes measured in mice in one day after continuous, partial-body irradiation at a high dose and conventional dose rate is smaller at the larger value of vR. Additionally, the model predicts at the same high dose (>10 Gy) a faster restoration of the blood lymphocyte population in humans exposed to continuous, partial-body irradiation at a FLASH dose rate compared to a conventional dose rate.

SiO2/WO3/ZnO based self-cleaning coatings for solar cells

The accumulation of pollution and any kinds of contamination on the glass cover of the solar cell affects the efficiency of the photovoltaic (PV) systems. The contamination on the glass cover can absorb and reflect a certain part of the sunlight irradiation, which can decrease the intensity of the light coming in through the glass cover. With the study, it was planned to develop self-cleaning coatings for the PV systems. It was aimed to prevent or reduce the contamination-induced efficiency loss of the existing PV systems. In the scope of the project, SiO2/WO3 and SiO2/WO3/ZnO composites were coated from their solutions on the glass substrates using a dip-coating technique. WO3 was selected as a photocatalyst semiconductor. Under the UV light irradiation, WO3 could absorb the photons of the UV light, generating the photoinduced charge carriers. The photoexcited charge carriers provide both the photoinduced hydrophilicity on the surface of the coating and the photocatalytic degradation of the organic contaminants accumulated on the surface of the coating, which allows water droplets to spread and flow on the surface of the cover glass to remove the contaminations. However, the recombination rate of the photoexcited charge carriers on the WO3 film was high. In order to suppress the recombination of the photoinduced charge carriers, WO3 was coupled with SiO2 and ZnO. Both of these semiconductors improved the photocatalytic activity of the WO3 film. Although SiO2 has superior features in terms of the light transmission, it was not very effective under UV light as a photocatalyst alone. The widely preferred photocatalyst ZnO was added into the composite film structure to enhance the photocatalytic activity. The self-cleaning mechanism of the film coatings on a solar cell was investigated through the photocatalytic dye removal efficiency on the as-prepared film samples. There was a slight decrease in the light transparency and the solar cell efficiency because of the WO3 content of the composite film. On the other hand, coupling the SiO2/WO3 film with ZnO enhanced the photocatalytic activity, and it suppressed the reduction effect of the WO3 phase on both the light transparency and the solar cell efficiency. The photocatalytic dye removal efficiency was increased to over 90% after 240 min of UVA light irradiation. In addition, the solar cell coated with the SiO2/WO3/ZnO film provided almost the same solar cell efficiency as the uncoated solar cell. The water contact angle measurement also exhibited the photocatalytic degradation of the model contamination on the glass cover of the solar cell under the UVA light irradiation.Graphical

Proton PBS Planning Techniques, Robustness Evaluation, and OAR Sparing for the Whole-Brain Part of Craniospinal Axis Irradiation.

Proton therapy is a promising modality for craniospinal irradiation (CSI), offering dosimetric advantages over conventional treatments. While significant attention has been paid to spine fields, for the brain fields, only dose reduction to the lens of the eye has been reported. Hence, the objective of this study is to assess the potential gains and feasibility of adopting different treatment planning techniques for the entire brain within the CSI target. To this end, eight previously treated CSI patients underwent retrospective replanning using various techniques: (1) intensity modulated proton therapy (IMPT) optimization, (2) the modification/addition of field directions, and (3) the pre-optimization removal of superficially placed spots. The target coverage robustness was evaluated and dose comparisons for lenses, cochleae, and scalp were conducted, considering potential biological dose increases. The target coverage robustness was maintained across all plans, with minor reductions when superficial spot removal was utilized. Single- and multifield optimization showed comparable target coverage robustness and organ-at-risk sparing. A significant scalp sparing was achieved in adults but only limited in pediatric cases. Superficial spot removal contributed to scalp V30 Gy reduction at the expense of lower coverage robustness in specific cases. Lens sparing benefits from multiple field directions, while cochlear sparing remains impractical. Based on the results, all investigated plan types are deemed clinically adoptable.

Surface unequal charging effect of GEO satellite

When a satellite is in orbit, the plasma environment interacts with the surface material, and the surface charge accumulation of different structures is inconsistent,resulting in an unequal charging effect. In serious cases, this leads to electrostatic discharge and affects the normal operation of the satellite. In this study, a three-dimensional model of a geosynchronous orbit (GEO) satellite is constructed, and the particle cloud grid algorithm (Particle-In-Cell,PIC) was used to simulate the charging process and the unequal charged state between the satellite panels in the solar wind plasma environment and the hot plasma environment. The simulation results show that in the solar wind plasma environment, the charging balance potential of solar panels is low and the charging difference between panels is small, which does not affect the normal operation of the satellite. However, when the satellite is in an hot plasma environment, if some parts of the satellite suddenly encounter extremely strong interference, the charging balance of the satellite in the solar wind plasma will be destroyed, and there will be a large potential difference between the irradiated part and the adjacent structure, which can easily cause electrostatic discharge to harm the normal operation of the satellite.

Stretching-Induced 2D-to-3D Shape Transformation of an Elastic Composite for Sensitivity-Tailorable Soft Electronics.

The shapes of rubbers and elastomers are challenging to alter, and current methods relying on permanent plasticity and dynamic cross-linking strategies are usually laborious and can inevitably compromise the network elasticity. Here, we report a photoresponsive elastic composite that can be programmed into 3D shapes by first UV light irradiation and then stretching. The composite comprises ethylene propylene rubber as the elastic substrate and photoliquefiable azobenzene small molecules as the responsive filler. Upon UV light irradiation, the liquefication of the filler induces the destruction of the crystalline aggregates near the irradiated surface, and after stretching and subsequent stress release, the irradiated part bends to the irradiated side based on a gradient network orientation mechanism. The position and amplitude of bending deformation can be controlled to realize a 2D-to-3D shape transformation. We further show that the resulting 3D-shaped elastomer can integrate with silver conductive paste to develop soft conductive lines with tailorable strain-sensitive conductivities. This study may open a new door for the development of shape-tailorable elastomers and soft electronics with designable strain-sensitive conductivities.

Broadband solar irradiation reflection by multilayer photonic structures with randomized layer thickness

Reflecting components based on photonic crystals that are optimized to reflect the Sun irradiation are very useful for energy applications. The employment of photonic structures as back reflectors in solar cells is widely studied. Moreover, photo-thermal effect employing photonic crystals to enhance photocatalysis is recently attracting increasing attention. Here, we show the efficient reflectivity of the whole solar irradiation spectrum with multilayer disordered photonic structures. To build a multilayer photonic structure that reflects a wide portion of the solar irradiation, a structure with a random distribution of layer thicknesses has been designed. A sequence of thicknesses for a 30-layer photonic structure, which allows a remarkable reflectance in the infrared part of the solar irradiation, has been determined with a proper algorithm. The angular dependence of the reflection of the photonic structure has been also studied. Such multilayers are made with Earth abundant materials, i.e., silicon dioxide and zirconium dioxide.

Experimental results for a MW-scale fluidized particle-in-tube solar receiver in its first test campaign

To advance the development of particle-driven technologies, this study presents experimental results of a megawatt-scale solar receiver installed atop the Themis Solar Tower (France). The whole experimental loop and the solar flux distribution at the receiver aperture are described with the associated instrumentation. The solar receiver is composed of forty 4-meter long metallic tubes, and the irradiated part size is 3 m high and 2.6 m wide. The facility was operated at partial load with a maximum solar power of approximately 800 kW with a particle mass flow rate ranging from 2148 kg/h to 12456 kg/h. The tube wall temperature distribution is presented along with a particle temperature increase that reached 400 °C. The dynamic behavior of the solar loop is detailed, in particular the starting phase. The thermal efficiency of the solar receiver ranges from 35 to 63%. An assessment of the lessons learned during this experimental campaign is offered.

Poly(Acrylic Acid)-Sodium Alginate Superabsorbent Hydrogels Synthesized by Electron Beam Irradiation Part I: Impact of Initiator Concentration and Irradiation Dose on Structure, Network Parameters and Swelling Properties.

In the present paper, hydrogels based on acrylic acid (20%), sodium alginate (0.5%) and poly(ethylene oxide) (0.1%) were obtained by electron beam irradiation at room temperature with doses between 5 and 20 kGy, using potassium persulfate in concentrations up to 0.3% as a reaction initiator. The influence of initiator concentration and irradiation dose on hydrogel network parameters, swelling and deswelling behavior, gelation and degradation points, structure and morphology were investigated. Cross-link density increased with the irradiation dose and initiator addition, except at 20 kGy. The gel fraction was over 87.0% in all cases. Swelling experiments in distilled water showed swelling degrees of 40,000% at an irradiation dose of 5 kGy when a concentration of 0.1% initiator was added. A relationship between the swelling degree and irradiation dose, cross-linking degree (that increases from 0.044 × 102 to 0.995 × 102 mol/cm3) and mesh size (that decreases from about 220 nm to 26 nm) was observed. The addition of only 0.1% of PP led to the obtaining of hydrogels with a swelling degree of 42,954% (about 430 g/g) at an irradiation dose of 5 kGy and of 7206% (about 62 g/g) at 20 kGy, which are higher percentages than those obtained in the same irradiation conditions but without PP.

Effect of UV-C Radiation on 3D Printed ABS-PC Polymers.

During the initial stages of the COVID-19 pandemic, healthcare facilities experienced severe shortages of personal protective equipment (PPE) and other medical supplies. Employing 3D printing to rapidly fabricate functional parts and equipment was one of the emergency solutions used to tackle these shortages. Using ultraviolet light in the UV-C band (wavelengths of 200 nm to 280 nm) might prove useful in sterilizing 3D printed parts, enabling their reusability. Most polymers, however, degrade under UV-C radiation, so it becomes necessary to determine what 3D printing materials can withstand the conditions found during medical equipment sterilization with UV-C. This paper analyzes the effect of accelerated aging through prolonged exposure to UV-C on the mechanical properties of parts 3D printed from a polycarbonate and acrylonitrile butadiene styrene polymer (ABS-PC). Samples 3D printed using a material extrusion process (MEX) went through a 24-h UV-C exposure aging cycle and then were tested versus a control group for changes in tensile strength, compressive strength and some selected material creep characteristics. Testing showed minimal mechanical property degradation following the irradiation procedure, with tensile strength being statistically the same for irradiated parts as those in the control group. Irradiated parts showed small losses in stiffness (5.2%) and compressive strength (6.5%). Scanning electron microscopy (SEM) was employed in order to assess if any changes occurred in the material structure.

UV photometric assays on paper-based analytical devices by contact printing photography through transparent cellophane

A limitation of paper-based devices that employ optical readout is that they can only be used for assays in the visible range of the electromagnetic spectrum. This work describes the first paper-based analytical devices that can be used for UV absorption photometric assays without scientific equipment. The devices consist of a transparent cellulose film (cellophane) as a reaction vessel and photometric cuvette and a photosensitive paper as a detector of UV irradiation. The analytes or their derivatives absorb part of the incident UV irradiation on the cellophane surface while the transmitted irradiation passes through the cellophane and photoreduces the surface of the photosensitive paper, producing an image. In this manner, the “colorimetrically invisible” UV absorption signaling is transformed into a visible image that can be captured and processed with common imaging devices. The analytical utility of these devices is demonstrated, as a proof-of-concept, for six UV-absorption model assays. The results show that cellophane-analytical devices are suitable for high-sensitivity measurements but exhibit a relatively large standard deviation, dictating multiple trials to correct the accuracy of the results. Technical aspects related to the improvement of the devices and the quality of analytical data are elucidated and discussed.

Comparison of 3D-Conformal Planning Using Partially Wide Tangents and Direct Photon/Electron Portals for Breast Radiotherapy with Internal Mammary Nodes Inclusion: A Dosimetric Analysis

Background: Internal mammary lymph nodes (IMNs) are a potential site of metastasis for breast cancer. Targeting IMNs as part of a comprehensive regional nodal irradiation comes at the cost of higher unwanted doses to critical nearby organs at risk. Thus, the efficacy and safety of different radiotherapy techniques for the coverage of this area remain elusive. Objectives: We present a dosimetric comparison between partially wide tangents (PWT) and direct photon/electron (P/E) portals in terms of target volume coverage and normal tissue sparing. Methods: Patients with left-sided breast cancer, who were referred to our clinic for post-lumpectomy or post-mastectomy radiotherapy, underwent computed tomography (CT) simulation. The left breast and IMNs, heart, lung, right breast, and esophagus were contoured. Dosimetric comparisons were based on dose-volume histograms (DVHs) generated for all of the aforementioned organs. A subgroup analysis was also performed based on patients’ type of surgical treatment. Results: A total of 30 patients (10 with breast conserving surgery and 20 with modified radical mastectomy) were included. The P/E plan provided a higher coverage of the left breast (P-value of CTV V105%: < 0.001) and IMNs with a P-value of 0.087 regarding the mean dose received by IMNs, and also less volume of the heart (P-value of Heart V30Gy: 0.021), and lungs (P-value of Lung V20Gy: 0.003) were irradiated. However, these advantages came at the cost of a higher dose to the esophagus and right breast and more hotspots compared to the PWT technique. Conclusions: The P/E technique had advantages regarding target volume coverage and toxicity regardless of the type of surgery. Based on the results of this study, overall, the P/E portal is superior to the PWT for radiotherapy of breast cancer with internal mammary node inclusion. However, the appropriate treatment plan should be decided on a case-by-case basis.

Effects of Flash Radiotherapy on Blood Lymphocytes in Humans and Small Laboratory Animals.

A mathematical model, which describes the level of surviving lymphocytes in the blood after ultra-high (FLASH) and lower dose rates of partial-body irradiation, is developed. The model is represented by simple analytic formulae that involve a few parameters, namely, physiologic parameters (characteristics of the blood flow through the blood circulatory system and its irradiated part), a biophysical parameter (a characteristic of the blood lymphocytes radiosensitivity), and the physical parameters (characteristics of irradiation). The model predicts that the level of surviving blood lymphocytes increases as the dose rate increases and approaches the limiting level of (1 - vR), where vR is the fraction of the blood volume in the irradiated part of the blood circulatory system. The model also predicts that the level of surviving blood lymphocytes after the same exposure is higher for lower vR. It is found that FLASH irradiation in humans with doses of 10 to 40 Gy and with exposure times significantly less (<1 s) than the blood circulation time (∼60 s) leads to the maximal blood lymphocyte sparing. Simple formula, which determines effective dose rates for optimal blood lymphocyte sparing, is derived in the framework of the developed model. For the dose range specified above, the obtained modeling prediction of the range of effective dose rates for optimal blood lymphocyte sparing in humans (namely, N ≥40 Gy/s) coincides with the dose rate range in FLASH radiation therapy. It is revealed that the respective effective dose rates for mice are higher than those for humans (for the same dose range) due to the shorter blood circulation time in mice than in humans. Proceeding from the findings obtained in this paper, a hypothesis elucidating the mechanisms of the abscopal effect of FLASH radiation therapy (namely, an antitumor response on metastases located outside of irradiated part of a body) is proposed.

Technical note: Temporal and thermal stability of optical response for silicone-based 3D radiochromic dosimeters.

Radiochromic silicone-based dosimeters are flexible 3D dosimeters, which at appropriate concentration of leucomalachite green (LMG) and curing agent are dose-rate independent for clinical photon beams. However, their dose response is based on chemical processes that can be influenced by temporal and thermal conditions, impacting measurement stability. The aim of this study was to investigate the temporal stability of the dose response of radiochromic dosimeters for different curing times and post-irradiation storage temperatures. Six cylindrical dosimeters (5cm diameter, 5cm length) were produced in a single batch and separated into two groups that were irradiated 72 and 118h after production. The same photon plan, consisting of two 10 × 1.6 cm2 opposing fields, was delivered to all dosimeters. After irradiation, the dosimeters were separated into three groups, stored at 5°C, 15°C, and 20°C, and read out for five consecutive days. Storage temperature influenced the measurement stability, and changes in the optical response with time differed between irradiated and non-irradiated parts of the dosimeters. The relative change between signal and background was greater than 10% for all measurements performed 24h or more after irradiation, except for dosimeters stored at 5°C, which changed by 2%-5% after 24h. The dosimeter temporal stability was not influenced by curing time. For room temperature storage (15°C and 20°C), readout should take place as soon as possible after irradiation since the background color increased rapidly for both curing times (72 and 118h), whereas the dosimeters are stored at 5°C, readout can be performed up to 24h after.

Effects of Whole and Partial Heart Irradiation on Collagen, Mast Cells, and Toll-like Receptor 4 in the Mouse Heart.

In radiation therapy of tumors in the chest, such as in lung or esophageal cancer, part of the heart may be situated in the radiation field. This can lead to the development of radiation-induced heart disease. The mechanisms by which radiation causes long-term injury to the heart are not fully understood, but investigations in pre-clinical research models can contribute to mechanistic insights. Recent developments in X-ray technology have enabled partial heart irradiation in mouse models. In this study, adult male and female C57BL/6J mice were exposed to whole heart (a single dose of 8 or 16 Gy) and partial heart irradiation (16 Gy to 40% of the heart). Plasma samples were collected at 5 days and 2 weeks after the irradiation for metabolomics analysis, and the cardiac collagen deposition, mast cell numbers, and left ventricular expression of Toll-like receptor 4 (TLR4) were examined in the irradiated and unirradiated parts of the heart at 6 months after the irradiation. Small differences were found in the plasma metabolite profiles between the groups. However, the collagen deposition did not differ between the irradiated and unirradiated parts of the heart, and radiation did not upregulate the mast cell numbers in either part of the heart. Lastly, an increase in the expression of TLR4 was seen only after a single dose of 8 Gy to the whole heart. These results suggest that adverse tissue remodeling was not different between the irradiated and unirradiated portions of the mouse heart. While there were no clear differences between male and female animals, additional work in larger cohorts may be required to confirm this result, and to test the inhibition of TLR4 as an intervention strategy in radiation-induced heart disease.

Моделирование поверхностно-объемного заряжения диэлектрика электронами с энергией от 6 до 30 keV

The physico-mathematical model applied to ground tests for geomagnetic plasma exposure based on the combined consideration of surface and bulk processes of transport and charge accumulation for calculating the kinetics of charging high-resistance dielectrics irradiated by medium-energy monoenergetic electrons (from 6 to 30 keV) is proposed. The model takes into account the contribution to the charging of the dielectric by the trains of longitudinal optical phonons generated by each thermalizing primary electron with energy below the band gap of the dielectric, which supplements the induced conduction current due to the generation of electron-hole pairs. As a result, the current induced by trains of longitudinal optical phonons of the tunnel conductivity through free electron traps is introdused, as well as the current induced in the conduction band due to multiphonon ionization the electron traps by trains of longutudinal optical phonons in the region of existence of electric field. Using the example of the α-Al2O3 (sapphire) dielectric, the results of computer simulation of the internal currents distributions, charges, and electric field in the dielectric with the open surface irradiated by monoenergetic electrons with energies from 6 to 30 keV are presented according with the achievement the quasi-equilibrium in the irradiated part of the dielectric and with switching of the energy of primary electrons during the irradiation process.

Enhanced light management and optimization of perovskite solar cells incorporating wavelength dependent reflectance modeling

Perovskite Solar Cells (PSCs) are the most promising candidates for low-cost and high-efficiency devices in the future photovoltaic market. PSCs are also used as the top cell in tandem devices with silicon bottom cells. However, research in PSCs is still at an early stage while racing towards a promising future. Along with experimental research, numerous simulation studies are conducted with PSCs aiming to analyze new materials and optimize their performance. Here, a wavelength-dependent model is implemented to account for the reflected part of irradiance from the cells, which is ignored in most SCAPS-1D based PSC simulated models. This model optimizes the MgF2 anti-reflective coating in SCAPS-1D simulation to allow maximum photons to pass inside the device. A simple structured PSC (MgF2/Glass/ITO/ZnO/CH3NH3PbI3/Spiro-OMeTAD/Au) is simulated and optimized optically as well as electrically with this model’s modified spectrum. The device was optimized for layer thickness, defects, and doping. Moreover, the effects of temperature and device resistances are discussed. The optimized device yields 21.62% power conversion efficiency, which can be further improved to reach over 25% through better processing schemes. Finally, the optimized device was compared with other devices having different ETL/absorber/HTL combinations and the pathway to achieving higher efficiencies was discussed. This article aims at improving the credibility of simulated devices by incorporating top surface reflection with electrical optimization.

RONC-14. Olfactory Perception During Proton Radiation and Differences in Frequency of Olfactory Perceptions Based on Proton Craniospinal Irradiation Technique for Pediatric Brain Tumor Patients.

Abstract BACKGROUND: Unusual olfactory perception has been reported during brain radiation treatments but is infrequent and does not typically interfere with the ability to deliver treatment or cause notable distress. Methods: We performed a retrospective review of 127 pediatric patients treated with proton radiation therapy (PRT) for primary brain tumors in a single institution between 2016-2021. Patients received PRT to the brain as part of craniospinal irradiation (CSI) followed by a boost to the brain. Proton CSI was delivered with 3D-CRT protons (n=53) or pencil beam scanning technique (PBS) (n=74). Within the PBS group, treatment delivery to the CSI utilized a single PA field (n=24) or two posterior oblique fields (n=50). We collected data on abnormal olfactory sensations, nausea/vomiting, and the use of medical intervention for those symptoms. Results: Our cohort included 80 males and 47 females. The median age of patients was 10 years old (range, 3 – 21). Seventy-one patients received concurrent chemotherapy. Prior to PRT, 31 patients were nauseous. During the radiation course, 104 patients developed worsening nausea while 63 patients reported emesis. Four patients vomited while receiving radiation. Seventeen patients reported olfactory perceptions during CSI. We found a higher rate of olfactory perception in patients treated with PBS (n=16, 22%) than 3D-CRT (n=1, 2%) (p=0.001) and, within the PBS group, patients treated with a single PA field (n=11, 46%) than two oblique fields (n=5, 10%) (p=0.002). Seventy-eight patients required intervention including addition of anti-emetic or anti-anxiety medication. Two patients required sedation due to the malodorous smell during CSI. We did not find any significant difference in nausea/vomiting based on treatment technique. Conclusions: PBS and PBS technique influence olfactory perceptions but not the occurrence of the rate of nausea/vomiting. Further studies should be performed to validate these findings and determine techniques to minimize unpleasant olfactory perceptions.

Design and analysis of a renewable energy driven greenhouse integrated with a solar still for arid climates

Closed or protected agriculture in arid climates requires a significant amount of energy to maintain optimum conditions due to the harsh external environment and unavailability of water for irrigation of crops. Therefore, this study proposes a novel greenhouse system integrated with a solar still that reduces the cooling load by absorbing a part of the incident solar irradiance. The greenhouse utilizes the humidification-dehumidification phenomena to supply cooling and water for the plants from the ambient air. The complete system consists of an evacuated tube collector, a greenhouse unit integrated with a solar still, an absorption cooling cycle, and thermal energy storage. A comprehensive thermodynamic model is developed and analyzed using the 1st and 2nd laws of thermodynamics. Moreover, the effect of solar irradiance, ambient temperature, and greenhouse operating parameters on the system’s performance is evaluated, demonstrating that the system can operate in a continuous and stable mode. Results illustrate that the humidification-dehumidification system inside the greenhouse produces sufficient water and cooling in an environment-friendly manner while the solar still reduces the cooling load by almost 20%. Moreover, the greenhouse maintains optimum temperature and relative humidity throughout the year while providing a space cooling load of 1437.95 kW and 4.03–5.20 m3/day of water. The proposed system provides an opportunity for year-round agriculture in harsh climates with a scarcity of fresh water. In addition, the system is flexible depending on the crop requirement and geographical location of the site.