Optimal Density Research Articles

Sintering behavior and thermal shock resistance of MgO-Mg2SiO4 refractories by co-doped silica fume and quicklime

To solve the serious environmental pollution of low-grade magnesite tailings, MgO-Mg2SiO4 refractories were prepared by low-grade magnesite tailings, materials and silica fume and quicklime as raw materials. The effects of calcium-silicate ratio (mol ratio) on the phase composition, microstructure, sintering behavior and thermal shock resistance of MgO-Mg2SiO4 refractories were investigated. When calcium-silicate ratio was 5/5, the samples showed the optimum bulk density and apparent porosity of 2.81 g/cm3 and 16.37 %, respectively. Controlled the calcium-silicate ratio of samples to 5/5 significantly improved the thermal shock resistance of samples, the residual compressive strength rate of 69.78 % and the residual flexural strength rate of 19.86 %, while the thermal parameter R was 34.45. The improvement in the thermal shock resistance can be attributed to the bonding phase transformation from monticellite phase to forsterite phase, thereby enhancing the bond strength between aggregate and matrix.

Experimental study on the low-temperature preheating performance of positive-temperature-coefficient heating film in the prismatic power battery module

The performance of a power battery directly affects the thermal safety performance of the vehicle. Aiming at the improvement of thermal safety of lithium-ion batteries under low temperature condition, this study focuses on the effect of the positive-temperature-coefficient (PTC) heating film on the heating performance of batteries through experimental testing. First, the side and bottom of the cell were heated, and the heat transfer path and mode of the single cell were analyzed. The effects of different power densities and geometric positions on the heating effect were studied by testing the heating time and temperature consistency. Second, for the battery module, a low-temperature heating thermal management heat transfer model was built to analyze the heating mechanism of the heating film under different heating power densities. Finally, the results of these studies were synthesized to obtain the optimal heating power density. The results show that for the cell, the optimum power density of side heating and bottom heating is 0.5 W /cm2 and 0.4 W /cm2, respectively. The time required for side heating from −20 °C to 10 °C is 730 s lower than that of bottom heating, and the maximum temperature difference is 1.885 °C lower. For battery modules, a power density of 0.5 W/cm2 was appropriate for both bottom and side heating methods. Due to the existence of heat conduction between battery packs, the battery modules will be quickly and evenly preheated. Under the optimal power density, the time length for side heating from –20 °C to 10 °C was 1459 s, and the maximum temperature difference was 6.32 °C; bottom heating time required slightly more time (1783 s), and the maximum temperature difference was 6.221 °C. Side heating can be beneficial for the rapid preheating of the battery module. This study will contribute to improving the performance and safety of batteries in cold environments.

A Novel Elastomeric Dielectric Materials: Natural Rubber/Copper-Modified Activated Carbon

In this research, a new elastomeric dielectric material is created by integrating natural rubber (NR) with activated carbon derived from coconut shells that has been modified with copper (Ac-Cu). Here, The copper content, ranging from 0 to 2%, was meticulously examined on the AC surface through a reduction technique from copper (II) to copper (0), with the Ac-Cu concentration fixed at 15 parts per hundred of rubber (phr). Systematic investigations into the effects of the additive were conducted across various parameters, encompassing optimum curing time (t90), density, crosslink density, mechanical properties, morphology, and dielectric properties. Results revealed a notable influence of copper on the curing process, resulting in decreased cure time, and a corresponding decrease in crosslink density as the copper content increased. Interestingly, copper incorporation demonstrated a positive impact on mechanical properties. Dielectric property analysis further confirmed a direct effect of increasing copper content on the frequency range of 0.85 to 1.15 GHz. This work not only introduces a pioneering dielectric material but also provides crucial insights into the nuanced effects of copper modification, offering avenues for tailored material design in the realm of enhanced dielectric applications.

Performance evaluation of high-performance concrete mixes incorporating recycled steel scale waste as fine aggregates

In this study, steel-scale waste (SSW), a byproduct generated during the manufacturing of steel, was investigated as a potential alternative to natural fine aggregates (sand) for preparing high-performance concrete (HPC). Three grades of sand and SSW with different particle sizes were mixed in varying combinations. Three different compaction techniques (loose, tamped, vibration) were employed. The optimum packing density for both SSW and natural aggregates was achieved using the vibration compaction method. Since the combination of 50 % sand and 50 % SSW exhibited the best packing density for both materials, this bi-grade aggregate mixture was selected for the mix preparation. The mechanical tests (compressive strength, flexural strength) and durability assessment (bulk water sorptivity, rate of water absorption, chloride ion penetration) were performed to achieve the desired objectives. The specimens were exposed to two different curing regimes i.e., normal curing and heat curing at elevated temperature. A significant increase in compressive and flexural strength was observed with the increased content of SSW. A compressive strength as high as 140 MPa was obtained for the HPC mix containing SSW aggregates and steel fibers. The replacement ratio of SSW was optimized to achieve better strength and durability. Experimental results showed that heat curing was more effective than conventional curing methods in improving the performance of the concrete.

Performance Optimization of MgHfS3 Chalcogenide Perovskite Solar Cells Using SCAPS-1D

In this work, magnesium hafnium sulfide MgHfS3 perovskite solar cells have been investigated using numerical modelling and simulation. Perovskite solar cells have received increasing recognition owing to their promising light-harvesting properties. The modelling and simulation of MgHfS3 was successfully carried out using the Solar cell capacitance simulator (SCAPS-1D) software. Consequently, this study developed a base model structure of FTO/TiO2/MgHfS3/Cu2O/Au and subsequently explored the effect of varying device layer properties such as absorber thickness, total and interface defect densities with a view of optimizing these parameters for better device performance. Simulating the base model gave the performance characteristics of 0.99 V, 25.21 mA/cm2, 57.59%, and 14.36% which are the open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF) and PCE respectively. The optimal absorber thickness was found to be 300 nm and the optimum density of defects for both TiO2/Absorber interface and Absorber/Cu2O interface are respectively 1010 cm-3 and 109 cm-3. The obtained optimized PV parameters are Voc = 1.2629 V, Jsc = 24.44 mA/cm2, FF = 89.46% and PCE = 27.61%. Also, it was established that increasing the device temperature beyond 300K enhanced the short circuit current while other performance characteristics gradually declined. The obtained results suggest that chalcogenide MgHfS3 is a potential absorber material candidate for the production of cheap and very efficient environment-friendly perovskite solar cells.

Removal of Ammonia and Colour from Landfill Leachate using Integrated Electrocoagulation-Zeolite Adsorption Processes

The amount of waste generated in Malaysia had increased annually due to both economic and population accelerations. This resulted in an increase in leachate production that contains a high amount of ammonia nitrogen (NH3-N) and colour, which is a severe problem for both environments as well as for human health. Therefore, this study aimed to determine the potential of Electrocoagulation (EC) – zeolite adsorption for removing NH3-N and colour from landfill leachate. In the experimental works, two batch studies consist of batch EC using aluminium (Al) cylindrical electrode and batch adsorption study using clinoptilolite zeolites adsorbent were conducted using leachate sample collected from Pulau Burung Sanitary Landfill (PBSL). The batch EC experiment was carried out to determine the optimum removal of NH3-N and colour by the effect of current density (7 - 35 mA/mm2), initial pH (5 - 9), electrolysis time (0 - 90 minutes) and inter-electrode distance (5 - 25 mm). An integrated EC - zeolite adsorption was carried out under the optimum condition of 2.0 g/150 mL adsorbent dosage, contact time of 100 minutes and an initial pH value of 8. Based on the experiment, almost 50% of NH3-N and 95% of colour were removed using a single EC under the optimum current density of 14.0 mA/mm2, pH 5, electrolysis time of 75 minutes and 15 mm of inter-electrode distance. A comparison of colour removal between single EC and EC-Zeolite showed the same degradation performance. The interaction of hydrogen ion (H+) with aluminium hydroxide ion (Al (OH)3) produces during EC stabilises small particles forming larger sludge that reduces colour concentration. The removal of NH3-N increased from 50.0% to 93% when EC was integrated with clinoptilolite zeolite adsorption. In conclusion, the results show that both processes can potentially remove colour while the integrated process effectively removes NH3-N from landfill leachate. The proposed treatment helps optimise process performance while minimising the operational cost of the treatment. Thus, the proposed integrated EC – zeolite adsorption processes can be an alternative to landfill leachate treatment which aligns with the 12thMalaysia Plan to reduce pollution and carbon emissions to become a carbon neutral nation as early as 2050.

Effect of stocking density on gonadal development, pigmentation and survival of Carassius carassius (Crucian carp) in a biofloc system

The present study was carried out to investigate the optimum stocking density for gonadal development, pigmentation, and survival of Carassius carassius stocked at varying stocking densities under a biofloc-based system. C. carassius (25 ± 0.15 g) were randomly distributed in sixteen tanks, each with 250 L water at the stocking densities viz. 1 kg/m3, 2 kg/m3, 3 kg/m3, 4 kg/m3 (10, 20, 30 and 40 fish/250 L). The carbon‑nitrogen ratio of 15:1 was maintained using wheat flour as a carbon source. The best gonad performance in terms of absolute fecundity (4449.98 ± 115.636), relative fecundity (114.67 ± 2.770), GSI (5.62 ± 0.018 and 2.93 ± 0.014 for females & males respectively), and advanced maturation stages (vitellogenic oocytes and seminiferous tubules with spermatozoa) was observed in the density treatment having 20 fish/250 L. The skin carotenoid content showed an increasing trend with maximum content (8.11 ± 0.018 μg/g)) recorded for the fish stocked at 20/250 L. The scales of the fish from the same treatment presented a higher concentration of yellow orange pigments giving an overall golden hue to the scales while as the density and dispersion of melanophores increased with an increase in stocking density giving an overall darker coloration to the fish, indicating a stressful condition at higher stocking density. The survival rate of fish showed no significant difference (p≥0.05) between the various density groups. The results of this experiment elucidate that Carassius carassius could be cultured with better gonad performance, increased carotenoid content, and high survival at a stocking density of 2 kg/m3 in a biofloc system.

Enhancing Seed Yield of Daincha (Sesbania aculeata L.) New Variety TRY1 Through Optimum Spacing and Nutrient Management

Background: Increasing demand for leguminous green manure crop daincha seed is being noticed throughout the country mainly to restore the soil fertility. For maximizing seed production of newly released daincha variety, an optimum plant density per unit area and fertilizer application are an important management tool. The study was conducted to optimize the plant spacing and fertilizer dose for achieving higher seed yield of daincha variety TRY 1. Methods: Field experiments were conducted during Summer and Kharif 2023 to study the effect of different spacing and fertilizer doses on growth, yield and economics of new daincha variety TRY1. The treatments consisted of five different spacing (S1-75×30 cm, S2-60×30 cm, S3-75×45cm, S4-60×45 cm and S5-90×30 cm) in main plots and three fertilizer levels (F1-12.5:25:12.5 kg N, P2O5, K2O ha-1, F2-18.75:37.5:18.75 kg N, P2O5, K2O ha-1, F3-25:50:25 kg N, P2O5, K2O ha-1 and control) in sub plots were tested. The treatments were replicated thrice in split plot design. Result: Growing of daincha variety TRY 1 at 60×45 cm spacing produced significantly taller plants (223 cm), more number of branches per plant (15.9) and dry matter production (1766 kg ha-1), yield parameters viz., higher mean number of pods per plant (114), pod length (22.4 cm) and seeds per pod (36.7), seed yield (567 kg ha-1), mean net returns (Rs.24512 ha-1) and benefit cost ratio (2.36) than other spacing. Application of 25:50:25 kg N, P2O5, K2O ha-1 recorded significantly mean taller plants (217 cm), more number of branches per plant (19.3), dry matter production (1831 kg ha-1), nodules/plant (40.7), more number of pods /plant (121), pod length (23.7 cm) and seeds per pod (37.8), seed yield (572 kg ha-1), net returns (Rs.23369 ha-1) and benefit cost ratio (2.20) over other fertilizer doses. Thus, the optimum spacing of 60×45 cm and fertilizer dose of 25: 50:25 kg N, P2O5, K2O ha-1 could be recommended for getting higher growth, yield parameters, seed yield, net returns and benefit cost ratio of newly released daincha variety TRY 1.

Electronic band structure and optical properties of BGaAsBi/GaAs using 16 band kp Hamiltonian

The numerical simulations of optical and electronic properties of BGaAsBi/GaAs quantum wells (QWs) are obtained by diagonalizing the 16-band kp Hamiltonian with distinct boron and bismuth compositions that exhibit multifaceted potential in 1.3–1.5 μm. It has been observed that under strain-relaxed conditions for a doping concentration of 12.5 % (B, Bi), the anticipated values of spin-orbit (SO) coupling energy (ΔSO) and the bandgap (Eg) are 302 meV and 0.952 eV, respectively. Additionally, strain interaction on band structure decreases the band gap from (Eg = 0.92eV–0.85eV), increasing dopant concentration from 8 % to 12.5 %. The consequence of incorporating both Bi and B impurity is a reduction in electron effective mass of BGaAsBi by ∼1.3 times concerning the host GaAs, enhancing the optical properties of BGaAsBi/GaAs quantum-confined heterostructures. Moreover, an increase in well-width introduced a red shift and reduced the peak amplitude of the gain spectra. In addition, for solar cell application, the onset of the fundamental absorption edge is depicted at an energy of about 0.96 eV. For laser applications, the optimum threshold current density and quality factor of BGaAsBi/GaAs quantum well achieved at room temperature are 1089 A/cm2 and 3653, respectively, at well width (w = 2.0 nm), cavity length (L = 0.5 mm), and average thickness of the active region (d = 45 nm). The variation in power density is studied with injected current density, while the quality factor is calculated with well width. The outcomes could be beneficial for future use in optical devices.

Verification of Protection Performance of Concrete Blast-Proof Panels Against Internal Explosions

Recently, studies on blast-proof panels, which were attached to structures to protect facilities from local damage caused by explosions, have been actively performed. However, blast-proof panels are impractical yet due to the high installation cost and difficulty in construction, and protection performance for explosions inside a structure is not evaluated. In this study, a blast-proof panel consisting of concrete material was devised to ensure economic feasibility and constructability. Then, the protection performance of the concrete blast-proof panel for internal explosions was analyzed by numerical simulations and field experiments. First, field experiments on concrete explosion-proof panels were conducted for two cases, where panels without and with energy-absorbing foam were installed. As a result, the concrete blast-proof panel reduced the displacement of structures by up to 22% and the acceleration of structures by up to 86%. However, the reliability of the field experiment data was insufficient due to the shear failure of the test structure during experiments. Therefore, additional analysis was conducted by developing a numerical model. A series of numerical simulations was conducted according to the various densities of the energy-absorbing foam that was inserted between the panel and structure. Consequently, the optimum density of the impact-absorbing material differed depending on the type of structure damage to reduce (i.e., the displacement or acceleration of the structure).

Winter wheat response to plant density in yield contest fields

AbstractSeeding rate recommendations for wheat (Triticum aestivum L.) are often 150–450 seeds m−2. However, we hypothesize that wheat grown with high resource availability (i.e., fertility and moisture) can maximize yield under considerably lower rates. Our objectives were to explore winter wheat response to low populations under high resource availability using yield‐contest fields as a case study. A factorial experiment evaluated four wheat varieties (i.e., Joe, WB‐Grainfield, Langin, and LCS Revere) exposed to five seeding rates (50, 100, 150, 200, and 250 seeds m−2) during five seasons in commercial wheat fields managed by yield‐contest winning producers near Leoti, KS. Fields were silt‐loam soils with high available water‐holding capacity, long‐term history of manure application with non‐limiting fertility, and adopted a sorghum [Sorghum bicolor (L.) Moench]–fallow–wheat rotation. Plant density ranged from 26 to 341 plants m−2 and yield ranged from 3.2 to 6.8 Mg ha−1. Water use efficiency of 19.5 kg ha−1 mm−1 suggested no management limitations to yield. Quadratic models portrayed the grain yield–plant density relation well, with 95% of the maximum yield reached at 68 to 91 plants m−2 for crops sown at the optimum date (4 out of 5 years), and at 312 plants m−2 for a late‐sown crop. Greater fall temperature accumulation reduced the relative yield between the maximum and minimum seeding rates. There was no variety × plant density interaction and Langin was the most consistent yielding variety across environments. Optimum plant density for winter wheat in environments with high resource availability may be considerably lower than current recommendations.

NQNHC Ligand-Enabled Cu(I)-Catalyzed Double Hydroamination: A Regio- and Chemoselective Bicyclization of o-Amino 1,6-Diyne.

In this work, we have developed an efficient method for the intramolecular double hydroamination of aniline by employing o-amino 1,6-diyne as a potential starting material. This protocol enables easy access to bioactive motif 3,4-dihydro-1H-[1,4]oxazino[4,3-a]indole through an intramolecular cascade bicyclization and concomitant isomerization pathway in one pot. This transformation has been effectively achieved by utilizing a stereoelectronically tuned, π-accepting NHC-supported copper(I) system. During ligand optimization trials, naphthoquinone-annulated N-heterocyclic carbene, Nq(IDipp) [1,3-bis(2,6-diisopropylphenyl)-4,5-naphthoquino-imidazolidene]-supported copper(I) complexes of the type Nq(IDipp)CuX (X = Cl or I) were synthesized and fully characterized using various spectroscopic techniques. For this conversion, NHC plays a crucial role in providing the optimum electron density around the metal center. It is a highly regio- and chemoselective transformation with a high atom economy and uses cheap, environmentally benign copper-based catalysts. Furthermore, a plausible mechanism has been proposed on the basis of experimental observations and literature support.

EFFECTS OF PLANT DENSITY ON MICRONUTRIENT UPTAKE IN SUNFLOWER (Helianthus annuus L.) VARIETIES

The objective of this study was to determine the effects of plant population per unit area on micro nutrients (Fe, Cu, Zn, Mn, B) uptake of some sunflower genotypes. Three sunflower varieties (Sanay MR, Oliva CL and LG5543 CL) were used as genetic material and three different plant populations: 40800, 57100 and 95200 plants/ha (sowing spacing; 0.35 x 0.70, 0.25 x 0.70 and 0.15 x 0.70 m, respectively). According to the results, the micronutrient concentrations as well as the seed and oil yields and partly also oil content increased significantly as the plant population increased. For all analysed micronutrients, the highest concentration has been obtained with 95200 plant ha-1. Micronutrient elements as well as seed and oil yields differed according to plant density and cultivars. Among the varieties, LG 5543 CL more effected by plant population had the highest micronutrient concentration, seed yield and oil yield. As a result, a high plant population (95,200 plant ha) with the highest micronutrient content and also the highest seed and oil yield could be recommended for Mediterranean environments with a semi-humid climate. However, optimum plant density was found differently according to varieties and years.

Separation and conversion of CO2 reduction products into high-concentration formic acid using bipolar membrane electrodialysis

Electrochemical CO2 reduction to value-added chemicals such as formate represents a crucial pathway in advancing carbon-neutral fuel production. However, the separation of formate from KHCO3 electrolyte solutions and its conversion to formic acid remain cost intensive steps in this process. This study demonstrated the use of bipolar membrane electrodialysis (BMED) to efficiently convert and concentrate formic acid directly from a cathodic solution for CO2 electroreduction. The migration of formate ions during BMED was optimized under different cell configurations and current densities. Mathematical modelling was developed to predict the concentration evolution curves of formic acid production. The results showed that formic acid diffusion through an anion-exchange membrane was more pronounced than that a bipolar membrane; the former diffusion was a key factor that limited the formic acid concentration and reduced the current efficiency. A formic acid concentration of 3.49 mol/L was obtained at an optimum current density of 40 mA/cm2 and a salt-to-acid compartment volume ratio of 25:1. Thus, BMED has emerged as a viable and effective technique for isolating high-purity formic acid from a cathodic solution for CO2 electroreduction.

Sorption thermal battery with solar powered absorption chiller for various building cooling applications

In the proposed sorption thermal energy storage (STES) system, the thermal energy storage (TES) tanks are integrated with solar assisted-absorption chiller (AC) to perform extended operation while matching the incompatibility of time gap between the renewable energy heat source and cooling demand of the building. In this study, the operating characteristics of sorption thermal battery (STB) at discharging process and storage capacity of STES charging process are studied. The feasibility study is conducted for four different types of buildings (hotel, hospital, single-family house, and office) to investigate the optimized discharging cooling capacity of STB and the optimized TES ratio. Under the condition of the 200 kWh of the building cooling load and cooling area of 181.63 m2, the most effectively meeting the demand is shown in the hotel, in which STES responds to 78.1 % of the cooling demand with 7.5 kW discharging cooling capacity of STB and 55 % charging the storage capacity of the STES system. The optimum energy storage density is 68.2 kWh/m3 and coefficient of performance is estimated of 0.41. The optimized STES can meet the cooling demand as much as 67.4 % for the hospital and 26.9 % for the single-family house. The office doesn’t require to apply the STES due to the absence of the cooling load at discharging period.

Mechanical Characteristics Rice Husk Fiber (RHF) Blended Recycled Polyethylene (RPE) for RHF/RPE Polymer Composite

This study investigates the mechanical characteristics of Rice Husk fibers (RHF) blended Recycled Polyethylene (RPE) to produce RHF/RPE polymer composites for building partition applications. The main objective is to formulate various composition ratios of RHF blended with RPE to fabricate optimum physical and mechanical properties to produce an RHF/RPE polymer composite. The significance of this research lies in developing a green polymer composite using natural resource materials such as RHF, which holds potential applications in Malaysia. Various ratios of RHF (0.2%, 0.4%, 0.6%, 0.8%, and 1.0% by weight) were combined with RPE to create RHF/RPE polymer composites. The RHF fibers were processed into fine fibers measuring 0.5 ± 0.05 mm using a high-speed grinding machine operating at 18000 rpm. The process involved blending RHF with RPE using a Bra-blender machine with a pressure of 20 kPa and a temperature of 120℃. The results indicated the composition ratio of 0.4 wt./wt.% of RHF/RPE polymer composite demonstrated the optimum density (ASTM C20-00) at 715.74 cm2 and porosity at 1.02 g/cm2, highest tensile strength at 0.60 MPa at tensile strength (ASTM D638) with SEM microstructure analysis confirming well-reinforced bonding between RHF/RPE matrix. The bending test at 0.4 wt./wt.% achieved the highest bending strength at 27.17 MPa, with a maximum bending strain of 2.41%, and the impact test (ASTM D256) demonstrated the highest impact strength at 36.16 MPa with an impact modulus of 1.25 MPa. It can be concluded that the optimal composition for building partition applications is 0.4 wt./wt.% of RHF/RPE polymer composites.

Optimum stocking density of adult freshwater crayfish Procambarus clarkii in recirculation system

Optimum stocking density of adult freshwater crayfish Procambarus clarkii in recirculation system

Tuning pore size and density of rigid polylactic acid foams through thermally induced phase separation and optimization using response surface methodology

Rigid polylactic acid (PLA) foams fabricated via thermally induced phase separation (TIPS) utilizing a ternary solution of PLA, Tetrahydrofuran (THF), and water. The PLA gels were stabilized mechanically by the substituting of the THF/water solvent mixture with ethanol as non-solvent and subsequently vacuum dried. A comprehensive characterization of PLA foams was achieved by Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD) and Brunauer–Emmett–Teller (BET) analyses. The BET area obtained in the PLA foam is up to 18.76 m2/g. The Response Surface Methodology (RSM) was utilized to assess the impacts of four independent variables (polymer concentration, solvent composition, quench temperature, and aging time) on the pore size and density of PLA foam. The experimental findings demonstrated that the fabrication parameters could be fine-tuned to govern the morphology of the pores, comprising their size and density. The optimal values of parameters for cell size were identified by RSM to be 8.96 (wt%), 91.60 (w/w), 5.50 °C, and 3.86 h for the optimum cell size of 37.96 µm (37.78 by Genetic Algorithm). Optimum density by RSM 88.88 mgr/cm3 (88.38 mgr/cm3 by Genetic Algorithm) was obtained at 5.00 (wt%), 89.33 (w/w), 14.40 °C and 2.65 h.

A numerical simulation and analysis of chalcogenide BaZrS3-based perovskite solar cells utilizing different hole transport materials

Recently, barium zirconium sulfide (BaZrS3) chalcogenide perovskite (CP) material has attracted much attention in the photovoltaic community because of its excellent light harvesting ability, stability, and nontoxicity. BaZrS3 has shown great potential in becoming the best alternative to hybrid halide perovskites. Herein, we have numerically simulated and optimized the performance of a device with the general architecture FTO/WS2/BaZrS3/HTL/Au, using SCAPS-1D (version 3.3.07) software. In this general device, inorganic CuSCN, Cu2O and organic poly(3-hexylthiophene) (P3HT) were inserted, and performance was evaluated as hole transport layer (HTL) materials. Moreover, the influence of various parameters on the device, such as the effect of changing the absorber defect density, varying the operation temperature, and using different metal back contacts, were examined. The best HTL material was organic P3HT, and it exhibited a power conversion efficiency (PCE) of 13.86 %, with a Fill factor (FF) of 11.97 %, open circuit voltage (Voc) of 6.58 V, and current density (Jsc) of 17.59 mA cm−2. The other tested inorganic CuSCN and Cu2O HTL showed a PCE of 13.83 and 13.70 %, respectively. For all the devices, the optimum density of defects was kept at 1.0 × 1015 cm−2. It was established that the P3HT-based device can operate and be stable between 240–––340 K temperature window, while devices with CuSCN and Cu2O can work between 280 – 400 K temperature range. Thus, the CuSCN- and Cu2O-based devices were more stable because they could form a more compact structure that can withstand relatively higher operation temperatures than organic-based devices with P3HT as HTL. Finally, it was established that relatively cheaper metals such as Pt, Ni, and Pd can be suitable alternatives to expensive gold metal back contact. It is expected that this work would shed additional light on the utilisation of BaZrS3 as a promising absorber material in the actual manufacturing of solar cells for clean energy production.

Validation of the Elekta iBEAM Evo couchtop modeling in the Monaco treatment planning system

IntroductionRecently, carbon fiber (CF) has prevailed as the primary material used in radiotherapy couchtops. Modern couchtops incorporate the CF sandwich design, in which two thin CF plates sandwich an air-equivalent polymeric foam. Developments in radiotherapy necessitate irradiation from posterior angles through the couchtop. However, the presence of the couchtop needs proper modeling in the Treatment Planning System (TPS) due to attenuation; otherwise, the tumor dose is reduced. In the current study, an effort was made with the intent of finding the optimum electron density (ED) values for Elekta's iBEAM Evo couchtop components (CF and Foam Core (FC)) for its proper modeling in Monaco TPS. Also, the attenuation of the beam due to the couchtop's presence was investigated. Materials and MethodsA cylindrical phantom with an ionization chamber positioned at the isocenter was utilized for the measurements. The phantom was placed centrally on the iBEAM Evo couchtop and was irradiated with an Elekta Infinity linear accelerator's 6, 10, and 15 MV photon beams. The gantry angle was set at 0o and from 120o to 180o with an increment of 10o. The same procedure was designed and followed in Monaco TPS. Measured and calculated dose values were compared by calculating percentage deviation (PD). Attenuation has also been calculated using the measurements of the experimental setup and the Monaco calculations. ResultsThe values of ED that provided the optimum agreement between measured and Monaco-calculated dose values while minimizing PD were 0.55 g/cm3 for CF, and 0.1 g/cm3 for FC. The maximum values of PD for the beams of 6, 10, and 15 MV were -0.62%, +1,78%, and +2.35% , respectively, for a 5x5 cm2 field size. Furthermore, Monaco predicted attenuation from 1.83% to 6.26% (calculated values), while from the measurements, an attenuation from 1.44% to 5.75% (measured values) regarding the posterior angles was found. Thus, good agreement was verified between the TPS calculations and experimental measurements. ConclusionsElekta's iBEAM Evo couchtop modeling was successfully validated in Monaco TPS. The couchtop's presence alters the patient's dose regarding irradiation from the posterior angles. Due to the attenuation of the beam, proper incorporation, modeling, and validation of the couchtop are necessary to improve the radiotherapy outcome and ensure that each patient receives the optimal treatment.