Rectangular Cell Research Articles

Simulation‐Based Analysis of Environmentally Friendly Perovskite Solar Cells: Projecting 21.61% Efficiency with Lead‐Free CsSn0.5Ge0.5I3

In this study, a simulation‐based analysis of environmentally friendly, lead‐free perovskite (PVK) solar cells (PSC) with high power conversion efficiency (PCE), is presented. Various PVK materials, including lead‐, tin‐, germanium‐, and tin–germanium‐based compounds, are evaluated through simulations to explore their impact on device performance. Among these, CsSn0.5Ge0.5I3 demonstrates the highest simulated efficiency, with a rectangular cell architecture of 0.45 × 0.9 mm. Key parameters such as thickness, temperature, doping concentration, and bandgap are systematically varied in the simulations to study their effects on device performance. The optimized architecture is found to be Au/Spiro‐MeOTAD (hole‐transport layer)/CsSn0.5Ge0.5I3/TiO2 (electron‐transport layer)/FTO, achieving a simulated PCE of 21.61%, with an open‐circuit voltage (Voc) of 1.2 V, short‐circuit current density (Jsc) of 21.32 mA cm−2, and fill factor of 84.43%. Furthermore, in this study, detailed electrical simulations (electric field distribution, Shockley–Read–Hall recombination, and electron and hole concentrations) and thermal simulations (nonradiative recombination heating, joule heating) of the device are included. In this work, the potential of lead‐free PSCs is underscored and the importance of continuous simulation studies to design eco‐friendly, high‐efficiency photovoltaic devices is highlighted.

Global tsunami modelling on a spherical multiple-cell grid

A model of shallow water equations (SWEs) on a spherical multiple-cell (SMC) grid of 4-level (2.5–5–10–20 km) spatial resolutions is used to simulate tsunami propagation on global ocean surfaces. The unstructured SMC grid retains rectangular cells of the longitude-latitude grid so that efficient finite-difference schemes could be used. It also supports multi-resolutions like mesh refinement to resolve small islands and coastline details while keeping models compact enough to fit into available computers. Two earthquake-induced tsunami cases are simulated and compared with available observations. Results indicate that the modelled tsunami arrival times agree well with observations while tsunami wave heights are underestimated, particularly the observed runups on remote coastal lands. Possible reasons for this underestimation include the smoothing scheme used to suppress numerical oscillations and the missing of initial kinetic energy input from the earthquakes. Another reason is the limitation of the SWEs to describe coastal bores and breaking waves in coastal waters. A possible tsunami scenario induced by a landslide in the Canary Islands is also simulated to assess its potential impact on Atlantic coastal regions. Model results indicate that this kind of tsunami may cause severe damage to local areas but its effects on far fields, like the UK and American coastal regions are small. As the initial landslide disturbance is overly simplified, this study does not give a true representation of a real landslide tsunami but rather a qualitative assessment of its impact on the Atlantic Ocean. More realistic initial condition and improved model representation of coastal processes are needed for further studies of this possible landslide hazard.

Design and characterization of a multi-ring nested CMUT array for hydrophone

This paper presents the design, fabrication, packaging, and characterization of a high-performance CMUT array. The array, which features rectangular cells fabricated using a sacrificial release process, achieves a receiving sensitivity of −231.44 dB (re: 1 V/μPa) with a 40 dB gain. Notably, the CMUT array exhibits a minimal sensitivity variation of just 0.87 dB across a temperature range of 0 to 60 °C. Furthermore, the output voltage non-linearity at 1 kHz is approximately 0.44%. These test results demonstrate that the reception performance of the 67-element CMUT array is superior to that of commercial transducers. The high performance and compact design of this CMUT array underscore its significant commercial potential for hydrophone applications.

Multiple high-Q resonances from mirror-coupled dielectric arrays

This paper reports how high-Q resonances can be created at multiple designated wavelengths in a low-index-contrast dielectric nanoparticle array coupled with a metal mirror. A rectangular array of TiO2 nanoparticles over a silver film (separated by a SiO2 spacer layer) can support collective resonances of magnetic and electric dipoles with their wavelengths determined mainly by the lattice spacings of the rectangular lattice. These resonances can be modulated by the spacer layer thickness to form accidental bound states in the continuum. Furthermore, resonances related to the periodicity along the diagonal of the rectangular unit cell can be produced by perturbing the lattice through modifying the dimensions of adjacent nanoparticles in the unit cell. Our result expands the potential of lattice resonances in low-index-contrast dielectric lattices, making them promising for applications in compact multi-wavelength and unidirectional light-emitting devices.

Spiral shaped highly sensitive rectangular PCF-based cancer cells detector in terahertz regime

Abstract The increasing fatality rate of cancer in the modern world has become a global concern. To address this issue, early detection of cancer cells in human blood is essential. In this article, a rectangular spiral shaped photonic crystal fiber has been proposed for sensing cancer cells in terahertz regime. The proposed PCF based sensor features a square shaped core surrounded by rectangular air holes of different sizes in a spiral manner. Finite element method based COMSOL Multiphysics software has been used for the design and analysis of the model. The model is sensitive to refractive index variation for the identification of cancer cells. The values of effective refractive index, effective mode area, relative sensitivity, non-linearity, and confinement loss are obtained for MCF-7, MDA-MB-231, Jurkat, HeLa, Basal and PC-12. The PCF based sensor resulted in excellent results of relative sensitivity and Confinement loss as good as 99.377% and 8.59 × 10−12 dBm−1 respectively. Furthermore, the present PCF based sensor model is fabrication feasible, and we hope that it can be utilized at industrial level for biosensing applications in terahertz waveguide regime.

Enhancing the melting rate of RT42 paraffin wax in a square cell with varied copper fin lengths and orientations: A numerical simulation

Latent thermal energy storage units are especially preferred in renewable thermal energy systems for their significant capacity to store heat. Nevertheless, the phase change materials in these units have low thermal conductivity, prompting researchers to tackle this problem using several methods, such as incorporating fins. This numerical study contributes to improving the charging rate of a square cell (50 × 50 mm) used paraffin wax RT42 as phase change material by adding 4 copper fins inside, 1 mm thick and of different lengths. The fins were positioned on the left wall, where a constant-temperature heat flux was applied, while the other walls were thermally insulated. Four configurations of the cell were examined: without fins, with 10 mm length fins, with 20 mm length fins, and with 30 mm length fins, respectively. The results demonstrated that the presence of fins significantly improved the charging rate of the square cell. Compared to the baseline configuration without fins, the time required for the paraffin wax RT42 to completely melt was reduced by 22.22 %, 33.33 %, and 55.56 % with fins of 10 mm, 20 mm, and 30 mm lengths, respectively. Configuration four was also compared with a setup where similar fins were positioned on the bottom wall while maintaining the heat flux on the left wall. It was observed that the total melting time doubled compared to configuration four, suggesting that the optimal placement for the heat flux is on the wall where the fins are located. The study contributes to enhancing and developing the charge rates of square and rectangular PCM cells such as these used for cooling PV panels.

Analytical prediction of the formation factor for anisotropic mono-sized unconsolidated porous media

The rectangular Representative Unit Cell (RUC) models for mono-sized isotropic unconsolidated porous media have been extended to anisotropic media. Volume averaging was applied to Ohm's law in order to propose analytical expressions for the formation factor for electrical conduction in terms of the pore-scale linear dimensions. The formation factor, crucial for understanding electrical conduction in porous media, has significant applications in subsurface geophysics, petroleum reservoir characterization, and the durability assessment of construction materials. These analytical models provide valuable insights for optimizing the electrical properties of porous structures in various engineering fields, for example in mapping groundwater resources, differentiating oil-bearing zones in reservoirs, and predicting ion migration in concrete. Aspect ratios of the cell and solid dimensions have been introduced, and the formation factor expressed in terms thereof for five different arrays, i.e. a regular, a non-overlapping streamwisely fully staggered, an overlapping streamwisely fully staggered, a non-overlapping transversally fully staggered, and an overlapping transversally fully staggered array. The Laplace equation has furthermore been solved numerically for two-dimensional versions of the different arrays and the formation factor computed for several values of the aspect ratios. The proposed analytical models have been validated against the generated numerical data and compared to experimental and numerical data obtained from the literature. The proposed models have also been adapted to include a percolation threshold porosity in order to improve the model predictions for very low porosity media.

Study of the Effects of Plasma Pretreatment on the Microstructure of Peanuts

In this study, cold plasma treatments are employed to modify peanuts. This study systematically investigates the effects of various plasma treatment conditions, including power, duration, and gas type, on the microstructure of peanut seed coats and embryos. Observations under a scanning electron microscope (SEM) reveal that as plasma treatment power increases from 100 W to 500 W, the etching level of peanut seed coats significantly intensifies, surface roughness deepens, and concavities become more pronounced. Additionally, micro-pores on the seed coat gradually enlarge and form cracks. Specifically, when the plasma treatment is set at 200 W for 60 s, the oxygen (O2) treatment group shows interconnected cracks on the peanut seed coat surface, with lipid particles exuding and protein particles and polymers decomposing. In contrast, the helium (He) treatment group displays clear cell structures and deep grooves, with no noticeable lipid particles exuding around surface cracks. The argon (Ar) treatment group exhibits a distinct rectangular cell structure with clear boundaries, and although surface cracks form, only a few protein particles escape from the cracks. The embryo surface structure becomes looser after plasma treatment, leading to the disintegration of lipid particles, protein particles, and polymers, affecting the fusion and migration of large and small lipid bodies within the peanut’s internal structure. Increasing treatment duration intensifies the etching phenomenon, resulting in more lipid particles exuding, which indicates a positive correlation between lipid particles exuding and treatment duration. This study sheds light on the mechanisms underlying changes in peanut microstructure due to cold plasma treatment, providing scientific evidence for improving peanut quality, enhancing oil extraction efficiency, and optimizing food processing techniques.

Performance enhancement of vanadium redox flow battery with novel streamlined design: Simulation and experimental validation

Electrolyte utilization and the consequent concentration polarization significantly limit the potential increase in power density and contribute to electrode degradation in vanadium redox flow batteries during cycling. This study investigates a novel curvature streamlined design, drawing inspiration from natural forms, aiming to enhance the performance of vanadium redox flow battery cells compared to conventional square and rectangular flow-through cell designs. The simulated 3D single-cell model shows a notably superior uniformity in both current and species' concentration distribution within the streamlined design compared to the square and rectangular shapes. Experimental analysis conducted on 3D-printed flow frames demonstrated 2 % enhanced energy efficiency and 47 % improved capacity when compared to rectangular design at 150 mA cm−2, all achieved with minimal increase in pressure drop.

Experimental study of solute diffusion in oscillating flow in a rectangular cell

Abstract The mass transfer of a passive substance dissolved in a fluid in a rectangular Hele–Shaw cell is experimentally studied. We consider mass transfer when the fluid is (i) at rest and (ii) oscillates. In the first case, mass transfer is carried out due to molecular diffusion. The results of measuring the molecular diffusion coefficient of the fluorescent dye Rhodamine B in water are in good agreement with the data obtained by other methods. In the presence of oscillations, the mass transfer rate increases. The comparison of the obtained experimental results with theoretical predictions reveals that the mass transfer is enhanced due to the Taylor dispersion.

The anatomy, micromorphology, and essential oils of the Turkish endemic and endangered species Alchemilla orduensis

In this study, the anatomical and micromorphological characteristics of the vegetative organs and the essential oil constituents of the aerial and underground parts of the local and endangered endemic species A. orduensis Pawł. were evaluated. For anatomical study, sections of root, rhizome, stem, leaves and petiole were excised and stained with safranin/fast green mixture. Leaf and petiole structures were examined micromorphologically. Essential oil contents were determined by headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) analysis. The results showed that rectangular meristematic cells were present in the root. The leaf is of the bifacial and amphistomatic type. Stomata cells are of the anomocytic type. The stomatal index for the upper surface of the leaves is 0.04, while the stomatal index for the lower surface is 0.17. Druse crystals were found in the rhizome, stem and leaves. Among the various compounds identified, the most abundant groups in the aboveground parts are alcohols (39.81%) and ketones (14.99%) with 1-Octen-3-ol, 1-octan-3-one and borane- methyl sulfide complex as the main compounds. Terpenes (23.44%) and alcohols (11.82%), in which myrtenolis was the main compound, were most abundant in the underground parts.

Vibration suppression of power cabin for underwater vehicle based on mechanical metamaterial flanges

The vibration of underwater vehicles affects their instrumentation and acoustic stealth capabilities. Mechanical metamaterials offer an advanced alternative to conventional vibration control methods. This study develops metamaterial flanges consisting of rectangular star-shaped cells with horizontal ligaments and localized masses. The vibration attenuation performance of metamaterial flanges within the power cabin is validated through simulations and experiments. This research examines the correlation between the bandgaps of large radial span unit cells and the frequencies of vibration attenuation, using the bandgap superposition effect. The findings reveal that the metamaterial cell exhibits exceptional load-bearing capacity and directional bandgaps in the low- to mid-frequency domain. Notably, the vibration attenuation achieved via bandgap superposition reaches 5.1 dB within 823 Hz to 1359 Hz. Specifically, within the range of 1017 Hz to 1146 Hz, the attenuation peaks at an impressive 18.6 dB. The metamaterial structure significantly reduces weight, decreasing the power cabin mass by 36.5%. This research offers new insights and serves as a valuable reference for vibration suppression in small- to medium-sized underwater vehicles.

Impact of the nature of the linker on the 2D and 3D organization of lipid-phenalenone conjugates

A series of phenalenone-lipid conjugates (1A, 1B, 1C, 2) have been synthesized to compensate for the poor water solubility of the photosensitizer phenalenone (PN) and promote the formation of nano-assemblies. We show that the organization and structure of monolayers upon compression strongly depend on the nature of the linker connecting PN to the lipid backbone, and the number of C18 chains. Monolayer properties at the air-water interface were analyzed by surface pressure measurements, Brewster angle and atomic force microscopies, grazing incidence X-ray diffraction, and X-ray reflectivity. Whereas conjugate 1C (ester bond) organizes into multilayers upon compression, conjugates 1A, 1B, and 2 form stable monolayers whose structure is controlled by van der Waals (vdW) interactions between C18 chains, intermolecular H-bonding involving the linker, and for 1B, π-π stacking of PN moieties. Conjugate 1A (amide-triazole linker) is structured into a rectangular network of chains with an order that extends only to the molecule of the adjacent cell. Conjugate 1B (amide bond) forms two incommensurate networks, one for the chains and the other for the headgroups. The distance between molecules in the next near neighbor chain lattice and the sufficient degree of freedom of PN groups allow the latter to pile up via π-π interactions below the chains in a rectangular cell. Conjugate 2 with its double chain adopts a similar behavior to that of a saturated phospholipid. Strong vdW interactions predominate and allow, at high surface pressure, hexagonal packing with no chain tilt. The distance between molecules prevents PN stacking. The identified PN derivative structures explain the linker’s impact on the formation and stability of nano-assemblies.

Fast approximation of the traveling salesman problem shortest route by rectangular cell clustering pattern to parallelize solving

A method of quickly obtaining an approximate solution to the traveling salesman problem (TSP) is suggested, where a dramatic computational speedup is guaranteed. The initial TSP is broken into open-loop TSPs by using a clustering method. The clustering method is based on either imposing a rectangular lattice on the nodes or dividing the dataset iteratively until the open-loop TSPs become sufficiently small. The open-loop TSPs are independent and so they can be solved in parallel without synchronization, whichever the solver is. Then the open-loop subroutes are assembled into an approximately shortest route of the initial TSP via the shortest connections. The assemblage pattern is a symmetric rectangular closed-loop serpentine. The iterative clustering can use the rectangular assembling approach as well. Alternatively, the iterative clustering can use the centroid TSP assembling approach, which requires solving a supplementary closed-loop TSP whose nodes are centroids of the open-loop-TSP clusters. Based on results of numerical simulation, it is ascertained that both the iterative clustering and rectangular cell clustering pattern are roughly equally accurate, but the latter is way more computationally efficient on squarish datasets. Fast approximation of the TSP shortest route serves as an upper bound. In addition, the route can be studied to find its bottlenecks, which subsequently are separated and another bunch of open-loop TSPs is approximately solved. For big-sized TSPs, where the balance of the accuracy loss and computational time is uncertain, the rectangular cell clustering pattern allows obtaining fast solution approximations on multitudinous non-synchronized parallel processor cores.

Enhancing Flow Batteries: Topology Optimization of Electrode Porosity and Shape Optimization of Cell Design

This research focuses on the improvement of porosity distribution within the electrode of an all‐vanadium redox flow battery (VRFB) and on optimizing novel cell designs. A half‐cell model, coupled with topology and shape optimization framework, is introduced. The multiobjective functional in both cases aims to minimize pressure drop while maximizing reaction rate within the cell. Topology optimization results reveal dependencies on initial value, porosity constraint, and flow rate. The distribution with lower porosity is preferred downstream of the inlet manifold. This design enhances active surface area, thus facilitating more effective conversion of incoming educts and improving mass transport of products. Compared to homogeneous electrodes, two‐part design demonstrates superior performance at specific porosity values. For combined porosities of 0.7 and 0.95, optimized distribution results in 81 % reduction in pressure drop, while conversion rate decreases by 7%. As regards various cell designs, optimization suggests a need to reconsider the vertical format of a rectangular cell. Horizontal cells are favored for nearly all porosities and flow rates. Trapezoidal and radial designs characterized by reduced downstream cross sections lead to higher pressure drops and are not preferred. This work provides further valuable insight into optimizing VRFB electrodes and challenges conventional cell design assumptions.

Heuristic approach to trajectory correlation functions in bounded regions with Lambert scattering walls

The behavior of spins undergoing Larmor precession in the presence of time varying fields is of interest to many research fields. The frequency shifts and relaxation resulting from these fields are related to their power spectrum, determined from the Fourier Transform of the auto-correlation functions of the time varying field. Using the method of images C. M. Swank, A. K. Petukhov, and R. Golub (2012 and 2016) calculated the position-position auto-correlation function for particles moving in a rectangular cell with specular scattering walls. In this work we present a heuristic model that applies the method of images to the case of Lambert scattering walls. The results of this model are compared to simulation and show remarkably good agreement from the ballistic to diffusive regime of gas collisions, for both square and general rectangular cells.

Assembly Structure Formation in Bulk and Ultrathin Films of Poly(substituted methylene) Having an Azobenzene Side Chain.

The density of the side chain introduced to a polymer main chain greatly influences the properties and functions of the polymer. This work first reports on the packing structure and properties at an interface of a poly(substituted methylene) where an azobenzene side chain is introduced at every carbon atom in the main chain (C1PAz). The structure and properties are compared with those of a conventional vinyl polymer [poly(methacrylate)] possessing an identical side-chain structure (C2PAz). The packing structure in the bulk state analyzed by X-ray measurements revealed that C1PAz adopts a highly ordered rectangular unit cell structure, whereas C2PAz shows a less ordered lamellar one. Langmuir film balance experiments indicated that both polymers with the trans-azobenzene give essentially the identical 2D side-chain occupying area on water, which agrees well with the smectic B (hexatic packing) model based on the X-ray data. Upon transfer onto a solid substrate, only C1PAz shows a conformational transformation to a spread bilayer-type layer, most probably due to conformational frustration stemming from the crowding of the side chains. This study proposes new insights into the effects of side-chain density on the self-assembly and photoreaction of azobenzene-containing polymers, which are expected to expand the possibilities of polymer design for various applications.

Anatomical structure of leaves in Magnolia kobus, M. obovata, M. denudata in the first stages of ontogenesis

In the ontogenesis of woody plants in general, and magnolia species in particular, the virginal age is quite long, and therefore is critically important from the point of view of selecting optimal conditions for growing plants. The study was conducted on biennial plants of deciduous magnolias: Magnolia kobus Sarg., M. obovata Thunb., M. denudata Desr. The studied plants were at the beginning of the virginile stage of development. The material for the investigation is selected from plants, which were planted by us in the research area of A. V. Fomin Botanical Garden of the Taras Shevchenko National University of Kyiv. In this study, we used scanning electron and light microscopes to examine the ultrastructure of the surface of leaves of the studied species. The histological characteristics of the leaves of the studied species are similar. They are hypostomatic. Their stomata are of the paracytic type, they are evenly distributed on the abaxial surface of the leaves. The epidermal cells of the studied species of the genus Magnolia have tortuous (cells located on the periphery of the leaf) or straight (cells located on the veins) outlines and rectangular (cells located on the veins) or flattened (cells placed on the periphery of the leaf) projection. The cuticle is relatively thin, located on both the abaxial and adaxial surfaces of the leaves. Epicuticular wax is observed of three types in the studied species: films (M. denudata), crust (M. kobus, M. obovata) and wax granules (M. denudata, M. obovata). The amount of wax and pubescence is greater on the abaxial surface in M. obovata; very weak pubescence and waxy layer is observed only on the abaxial surface of the leaf in M. kobus, weak pubescence is present on both sides in M. denudata. In all species of the genus Magnolia pubescence is simple, formed by hairs that "accompany" the veins. There are two main types of lamina relief in the studied species: reticular (M. obovata, M. denudata (subtype reticular-collicular)) and pitted (M. kobus). The species clearly differ in this feature, so we believe that the type of relief of the lamina can be used as an additional diagnostic feature to distinguish species of the genus Magnolia. Magnolia denudata is characterized by a small number of stomata, while M. obovata and M. kobus are characterized by their average number. The Stomata Index varies from 2.8 in M. denudata to 1.02 in M. kobus. The lamina is the thickest in M. obovata, the thinnest is in M. kobus, but the total thickness of the epidermal tissue as a percentage of the thickness of the leaf is, in descending order: M. denudata (29%), M. kobus (24%), M. obovata (18%). The mesophyll varies from homogeneous-spongy (in M. kobus) to layered (in M. obovata, M. denudata) type. The number of layers of cells that form the mesophyll in all studied species is from 4 to 6. Thus, M. kobus is characterized by the least specialized type of mesophyll. The vascular system in the studied plants is represented by small central and lateral vascular bundles. The ground tissue is present only in the central and large side bundles. In the early stages of ontogenesis the studied plants are typical mesophytes with hypostomatic leaves adapted to exist in sufficiently moist conditions in soil and air. In practical terms, the results of investigation can be used to select optimal conditions for growing plants at the initial stages of ontogenesis.

Exploring the possibility of adding DGGS support to the S-100 Universal Hydrographic Data Model

reference systems. A DGGS is a spatial reference system consisting of multiple layers of grids with increasing resolution which partition the globe into polygon shaped cells of equal area. Individual cells can be easily identified and basic Geographic Information System (GIS) operations can be performed on data stored within the cells. Advantages of using DGGS for spatial data include the ability to integrate data layers of different data types in a statistically uniform way, the possibility to avoid distortions caused from projection, and the capability to scale analysis across multiple resolution levels. The benefits of using DGGS for hydrographic data, specifically Electronic Navigational Charts (ENC) are examined. The addition of DGGS to S-100 would provide a uniform gridding system for ENC cells, and would eliminate distortions in the Polar Regions caused when projecting rectangular cells based on latitude and longitude. The Open Geospatial Consortium (OGC) led a pilot project for which one of the participants developed a server that offers S-100 marine protected area data organized according to DGGS. Because of this success and the availability of open-source software for the implementation of DGGS, the BSH (German Federal Maritime and Hydrographic Agency) investigated the feasibility and possible benefits of using Discrete Global Grid Systems for S-100 data. The outcome was successful. However, it is recognized that DGGS as a standard is not yet advanced enough and the available software tools are inadequate for wide implementation. More investigation needs to be done, and additionally the best grid shape, orientation and aperture for a uniform grid for hydrographic data need to be determined. Overall, DGGS should be considered for future versions of S-100, the new universal hydrographic data model, because the benefits for ENCs and hydrographic data are clear and in the future, it is expected that DGGS will revolutionize GIS.

Morphology and Compressive Properties of Extruded Polyethylene Terephthalate Foam.

The cell structure and compressive properties of extruded polyethylene terephthalate (PET) foam with different densities were studied. The die of the PET foaming extruder is a special multi-hole breaker plate, which results in a honeycomb-shaped foam block. The SEM analysis showed that the aspect ratio and cell wall thickness of the strand border is greater than that of the strand body. The cells are elongated and stronger in the extruding direction, and the foam anisotropy of the structure and compressive properties decrease with increasing density. The compression results show typical stress-strain curves even though the extruded PET foam is composed of multiple foamed strands. The compression properties of PET foam vary in each of the three directions, with the best performing direction (i.e., extrusion direction) showing stretch-dominated structures, while the other two directions show bending-dominated structures. Foam mechanics models based on both rectangular and elongated Kelvin cell geometries were considered to predict the compressive properties of PET foams in terms of relative density, structure anisotropy, and the properties of the raw polymer. The results show that the modulus and strength anisotropy of PET foam can be reasonably predicted by the rectangular cell model, but more accurate predictions were obtained with an appropriately assumed elongated Kelvin model.