Original Shape Research Articles

Effective Press Folding Line Process as Producing Smart Intersection in Square Steel Pipe Structures by Using Crushed Cross Section Compactly

As a cross section of square steel pipe is crushed, the upper plate and the lower plate deform inward, and the side plates deform outward from the original square cross section shape. When the press folding line process as deformation induction is applied, the upper plate and the lower plate keep flat, and the side plates are compactly folded inward. This deformation pattern is safe without causing any harm to the surrounding area, and makes it possible to improve impact energy absorption performance by folding side plates as overlapping. Moreover, square steel pipe structures include places as pipes intersect and places to avoid interference with other parts (piping, wiring, fork claws, etc.). In such cases, the current method is to create an opening by cutting off. At that time, the structural strength will decrease, so reinforcing materials are often installed as a countermeasure. On the other hand, if the opening is processed by laterally impact crushing using the press folding line process proposed in this paper, a crushed part will remain, suppressing the decrease in structural strength, and this can be handled without adding reinforcing material to be a smart intersection. This paper shows the findings based on experimental data, FEM (Finite Element Method) results on processing conditions for inward deforming side plates of square steel pipes and evaluation of impact energy absorption performance in laterally impact crushing.

A blind flow fingerprinting and correlation method against disturbed anonymous traffic based on pattern reconstruction

Tor is the most widely used anonymous communication system at present which can anonymize users’ network behavior. At the same time, many illegal network activities also appear more frequently with the help of Tor, posing serious challenges for cyberspace security. Therefore, flow fingerprinting and flow correlation analysis methods are put forward to de-anonymize the malicious anonymous behaviors, which utilize external traffic features as the side-channel information. However, the adversary often reduces the ability of above two methods by adding the disturbance to the anonymous traffic. As a countermeasure against the interference, disturbance-resistant analysis methods can effectively identify those adversarial behaviors while knowing how the traffic is modified. However, in real scenarios, it is unrealistic to distinguish between disturbed and non-disturbed anonymous traffic, let alone to have a clear grasp of the disturbing strategy. In this paper, we propose a blind anonymous traffic analysis method called Blind Analyzer based on pattern reconstruction skills in a “masking-generation” manner. Specifically, Blind Analyzer extracts the pattern knowledge from non-disturbed traffic samples by masking and reconstructing them. During the method application, disturbed anonymous traces are processed following the same way, aiming at removing the incremental noise at the masking stage and restoring the original shape at the reconstruction stage. Besides, a conditional discriminator is designed to determine whether the generated sample has obvious class characteristics. Benefited from the proposed method, we can improve the effectiveness of the anonymous network behavior analysis since the disturbed traffic can be restored as normal ones accurately enough. Experiment results on three datasets show that reconstructed traffic samples output by Blind Analyzer are more useful for base analysis models, which improve the corresponding metric values by 11.23% and 6.61% in max for flow fingerprinting and correlation tasks, respectively.

Pore-scale study of coupled heat and mass transfer during primary freeze-drying using an irregular pore network model

This study presents a pore network (PN) model with transient heat transfer and quasi-steady transitional vapor transport that is for the first time applied to irregular porous structures that are obtained by reconstruction of X-ray tomography image data. In contrast to previous studies, the irregular pores are not approximated by spheres but implemented in their original shape. Secondly, instead of assuming cylindrical throats as pore connections, the actual distance between pore centers as well as the pore cross sections are used for the computation of the vapor transport coefficient. The control volume elements of the computational model are matched with the cells obtained by Voronoi tessellation. The improvements have clear advantages over former approaches where the reconstructed void space is usually strongly simplified by balls and sticks confined in a regular lattice structure. A freeze-dried sample of maltodextrin DE12 with 20% (w/w) solid content is used for benchmarking the new methodology. Its morphological and thermal properties are determined by the novel PN model. The simulation results of primary freeze-drying (FD) are compared to reference cases in two ways. First, the differences in heat and mass transfer kinetics as compared to regular PNs are emphasized. Secondly, the PN simulation results are confronted with a simple literature model that neglects pore size distribution (PSD) and transient heat transfer. It is shown that already in small domains with relatively narrow PSD, the variation of the mass transfer coefficient affects the computed sublimation fluxes and yields a significant deviation from the simpler literature model. Moreover, it is revealed in this study that the structure has a significant impact on the sublimation front temperature. This is demonstrated by the comparison of FD in the irregular PN to a regular PN with almost identical PSD but different porosity. The development, verification, and benchmarking of the new PN model can be seen as an important step for studies of the structure dependence of FD.

Morphological Factors and Forces Acting in Normal and Sickled Erythrocytes in Sickle Cell Anemia: A Mathematical Model

We carried out a theoretical study that considers the morphological factors and forces acting on a normal and a sickled blood cell. Sickle cell disease is associated with vaso-occlusion which creates blood flow crises as a result of loss in shape memory of the normal red blood cell. Certain forces and chemical compositions acting on the cell could retain the shape memory. The problem of a second order partial differential equation modeled was solved to get the forces and chemical composition required to restore the sickled red blood cells back to its original shape. The results gotten showed that, increase in chemical reaction increased the RBC growth by creating a stretching force that causes the sickle cell to regain elasticity with improved oxygen.

Assembly of Chitosan/Caragana Fibers to Construct an Underwater Superelastic 2D Layer-Supported 3D Architecture for Rapid Congo Red Removal.

Developing environmentally friendly bulk materials capable of easily and thoroughly removing trace amounts of dye pollutants from water to rapidly obtain clean water has always been a goal pursued by researchers. Herein, a green material with a 3D architecture and with strong underwater rebounding and fatigue resistance ability was prepared by means of the assembly of biopolymer chitosan (CS) and natural caraganate fibers (CKFs) under freezing conditions. The CKFs can randomly and uniformly distribute in the lamellar structure formed during the freezing process of CS and CKFs, playing a role similar to that of "steel bars" in concrete, thus providing longitudinal support for the 3D-architecture material. The 2D layers formed by CS and CKFs as the main basic units can provide the material with a higher strength. The 3D-architecture material can bear the compressive force of a weight underwater for multiple cycles, meeting the requirements for water purification. The underwater compression test shows that the 3D-architecture material can quickly rebound to its original shape after removing the stress. This 3D-architecture material can be used to purify dye-containing water. When its dosage is 3 g/L, the material can remove 99.65% of the Congo Red (CR) in a 50 mg/L dye solution. The adsorption performance of the 3D architecture adsorbent for CR removal in actual water samples (i.e., tap water, seawater) is superior than that of commercial activated carbon. Due to its porous block characteristics, this material can be used for the continuous and efficient treatment of wastewater containing trace amounts of CR dye to obtain pure clean water, meaning that it has great potential for the effective purification of dye wastewater.

Exploring the cyanobacterial diversity in Portugal: Description of four new genera from LEGE-CC using thepolyphasic approach.

Culture collections such as the Blue Biotechnology and Ecotoxicology Culture Collection (LEGE-CC) hold approximately 1200 cyanobacterial strains and are critical community resources. However, many isolates in this and other collections have not been described with a polyphasic approach, and this limits further study. Here, we employed a polyphasic methodology that integrates 16S rRNA gene phylogenetic analyses, similarity (p-distance), 16S-23S ITS rRNA region secondary structures, morphological analyses, and habitat assessments to describe four novel cyanobacterial genera from the LEGE-CC, Portugal. Pseudolimnococcus planktonicus gen. et sp. nov. (Chroococcales) is phylogenetically and morphologically related to Limnococcus. The 16S rRNA gene similarity between the types of both genera is only 93.1%. Morphologically, Pseudolimnococcus cells do not reach the original spherical shape before the next division or have aerotopes and firm mucilage, while Limnococcus cells reach the original shape, lack aerotopes, and have diffluent mucilage. Eucapsopsis lusitanus gen. et sp. nov. (Chroococcales) is morphologically similar to Eucapsis but differs from it by having aerotopes and diffluent envelope. Eucapsis lacks aerotopes and has firm mucilaginous envelopes, rarely diffluent. Both genera are phylogenetically very distant from each other and have only 90.68% 16S rRNA gene similarity. Pseudoacaryochloris arrabidensis gen. et sp. nov. (Acaryochloridales) differs from Acaryochloris by the lack of mucilaginous envelope, which is present in Acaryochloris. Both genera are phylogenetically distant and have only 94.1% 16S rRNA gene similarity. Moreover, Acaryochloris is marine (sponge symbiont), while Pseudoacaryochloris is from freshwater. Vasconcelosia minhoensis gen. et sp. nov. (Nodosilineales) is phylogenetically related to Cymatolege but has only 94.3% similarity with this genus. Morphologically both genera are distinct. Vasconcelosia has a Romeria-like structure, while Cymatolege has a Phormidium-like structure. In all cases the 16S-23S ITS rRNA region secondary structures are in agreement with the other analyses. These novel genera expand the diversity of cyanobacteria in culture collections.

Surface modification of h‐BN and electric field control of its orientation in sulfonated polyetheretherketone

AbstractSince thermally conductive fillers easily aggregate when introduced into polymer matrix, it is essential to apply a modifier to enhance the dispersion of the filler. In current study, the surface of boron nitride (h‐BN) is firstly modified by employing a double modification process and then added into sulfonated polyetheretherketone (SPEEK) to form the composite materials. Four different kinds of samples of double‐modified h‐BN were obtained. Ultimately, the XXX@h‐BN/SPEEK (XXX denoted as modifier, i.e. PDA, VTMS, TEOS, and APS) flexible film with the horizontally oriented XXX@h‐BN was produced by heating the mixture under an external electric field. The test results indicate that the thermally conductive filler PDA@h‐BN (PDA: polydopamine), which was prepared by modifying OH@h‐BN with PDA, loaded into SPEEK, and electrically oriented, shows the best overall performances. With a high tensile strength of 43.24 MPa and good flexibility, PDA@h‐BN/SPEEK flexible film exhibits an in‐plane thermal conductivity of 2.3 Wm−1 K−1 at a filling ratio of 10 wt%. The sample may be bent at a steep angle without breaking down and can recover to original shape bearing its high degree of flexibility.

Biaxially stretchable metamaterial absorber with a four-dimensional printed shape-memory actuator

Among the various methods for strain sensing, the metamaterial absorbers (MMAs) stand out due to their dual capabilities. Specifically, MMAs facilitate the wireless detection of deformations in the target and operate independently of any external power source. However, conventional research has a limitation in that stretchable strain sensors are unable to deform themselves autonomously, which puts constraints on being efficiently utilised in special environments where human intervention is difficult. Herein, we propose a wireless, power-independent, biaxial strain sensor equipped with self-shape and frequency recovery capability that addresses the limitations of existing wireless strain sensors through the unprecedented integration of a 4D-printed shape memory actuator and a biaxially stretchable MMA. The novel integration with the shape memory actuator enables the stretchable MMA to autonomously recover to its original shape and absorption frequency after being heated to 70 °C for a few minutes. This smart functionality enables the resulting wireless strain sensor based on the proposed idea to revert to the original state when sensing a new target without requiring human intervention. The highly sensitive biaxial sensing capability is as follows. When stretched horizontally from 0 % to 30 %, the absorption frequency of the proposed biaxially stretchable MMA demonstrates a linear change from 9.75 GHz to 7.94 GHz, exhibiting a high sensitivity of 4.3 × 10^7 Hz/%. Similarly, when stretched vertically from 0 % to 30 %, the absorption frequency linearly changes from 7.35 GHz to 6.01 GHz, indicating a sensitivity of 5.9 × 10^7 Hz/%. Accordingly, the wireless biaxial sensing capability of the proposed stretchable MMA, as well as its shape-recovery functionality facilitated by the 4D-printed actuator are highly effective for remote strain measurement in environments where direct human involvement is impractical.

Advancements in shape-memory alloys: Properties, applications, challenges, and future prospects

Shape-memory alloys (SMAs) are advanced engineering materials that have gained significant attention in recent years due to their unique properties and potential applications. SMAs have the remarkable ability to recover their original shape after deformation, making them invaluable in various fields, from biomedical devices to aerospace engineering. Despite their many advantages, SMAs also face several challenges, including the need for improved processing techniques and the development of more efficient actuation systems. To address these challenges, researchers have adopted various approaches, including using advanced fabrication methods and developing novel actuation systems. Recent research has yielded several notable achievements in the field of SMAs. For example, researchers have developed new processing techniques that allow the production of SMAs with improved properties, such as higher strength and better fatigue resistance. Additionally, researchers have developed new actuation systems that allow for more precise and efficient control of SMA behavior. Looking ahead, the future of SMAs looks promising. With continued research and development, SMAs have the potential to revolutionize various fields, from aerospace engineering to biomedical devices. However, further work is needed to overcome the remaining challenges and fully realize the potential of these remarkable materials. This article provides a comprehensive overview of SMAs, including their properties, fabrication methods, and various applications. It also discusses the challenges facing the field, the approaches to address them, and recent achievements.

A Reconfigurable Proangiogenic Hydrogel Patch Enabling Minimally Invasive Drug Delivery.

Hydrogel is widely used for the sustained delivery of bioactive molecules that can treat various injuries, diseases, and tissue defects. However, inserting hydrogel implants without disrupting their functionality and microstructure often requires a large incision, leading to potential complications, such as infection, scarring, and pain. The gel implant is often manually rolled and inserted through a catheter for a minimally invasive delivery. However, success heavily depends on the user's skills, which can inadvertently damage the implant. To address this issue, we developed a reconfigurable hydrogel patch that can self-fold into a small tube and unfold spontaneously after implantation through a catheter. The hydrogel path was assembled by layering a drug-releasing poly(ethylene glycol) diacrylate (PEGDA) hydrogel sheet onto a PEGDA and polyethylenimine (PEI) hydrogel sheet, which rapidly swells and degrades homogeneously at controlled rates. The dynamics of the self-folding and unfolding process could be controlled by differences in the expansion ratio and elastic modulus between the two gel layers according to a mathematical model that closely matched experimental results. The unfolding process triggered a sustained release of the protein cargo. Specifically, the reconfigurable gel loaded with angiopoietin 1 significantly enhanced neovascularization, nearly doubling the vascular density compared to the control group following implantation through a tube with 15% smaller diameter than the original shape of the gel patch. This gel biopatch will be broadly useful for the minimally invasive delivery of a wide array of therapeutic molecules, potentially enhancing therapeutic outcomes.

The influence of acid rain on asphalt and its mixture performance, simulation and micro-mechanism exploration

Acid rain will destroy asphalt roads and affect human production and life. Therefore, this study has designed a new indoor simulated acid rain erosion test, and explored the effects of acid rain on the properties of 70# petroleum asphalt, SBS asphalt and their mixtures and the acid rain erosion mechanism from the micro and macro perspectives. In this paper, the influence of acid rain erosion on the microscopic properties of asphalt has been revealed through microscopic experiments. Through the combination with the basic performance test of asphalt, the effect of acid rain erosion on the conventional properties of asphalt was studied. The effects of acid rain on the properties of road asphalt mixtures were studied by Marshall immersion and high-temperature rutting tests. The results show that there is no obvious chemical reaction between the two kinds of asphalt after acid rain erosion, but the surface structure and morphology have changed significantly. There was a mass loss, the decreases of the softening point and ductility, and an increase of the penetration; the residual stability and high temperature resistance of both asphalt mixtures were reduced. In the worst case, the quality of petroleum asphalt was lost by 82.2%, the softening point and ductility decreased by 9.6% and 16.9% respectively, the penetration degree increased by 3.1% and the residual stability and dynamic stability of petroleum asphalt mixture decreased by 8.82% and 27.9% respectively. The mass loss of SBS asphalt was 82.5%, the softening point and ductility decreased by 5% and 3.3% respectively, the penetration increased by 2.6%, and the residual stability and dynamic stability of SBS asphalt mixture decreased by 4.82% and 25.4% respectively. In general, under the action of acid rain, the performance of 70# oil asphalt, SBS asphalt and their mixtures are affected to varying degrees. The specific performance is to destroy the original shape of asphalt, resulting in the loss of quality of asphalt, the reduction of deformation resistance, high temperature stability and low temperature stability of asphalt, weakening the high temperature stability and water stability of asphalt mixture, and leading to the decline of road performance.

Fully-Coupled Electric-Thermal-Flow Modeling and Investigation of Dynamic Thermal-Ledge Behavior in Aluminum Electrolysis Cell

Aluminum electrolysis cells (AECs) require effective thermal regulation to operate flexibly alongside renewable energy sources. Prior to implementing thermal regulation strategies, it is essential to predict the dynamic variations in the thermal field and ledge characteristics of a full-scale cell. This study introduces a transient electro-thermal-flow coupling model for a full-scale AEC, aimed at investigating the interactions between ledge distribution and various operational fields, including thermal, electric, and flow fields. The model facilitates the calculation and assessment of the dynamic properties of the ledge and thermal balance under ±15% flexible current variations. Results indicate that during a current increase, ledge melting predominantly occurs in the electrolyte layer, while ledge solidification is primarily observed in the metal layer during a current reduction. Regions with a thicker ledge and faster velocity tend to melt more during current increases and are less likely to return to their original shape and thickness during current reductions, complicating the rapid restoration of thermal equilibrium. To achieve uniform ledge distribution and real-time adaptation to flexible current variations, it is recommended to install distributed cooling devices on the sides of the AEC to enable differential ledge regulation at various locations.

One-step self-assembled biomass carbon aerogel/carbon nanotube/cellulose nanofiber composite for supercapacitor flexible electrode

Flexible and exceptionally lightweight energy storage devices are crucial for wearable electronic gadgets. Biomass materials are emerging as ideal flexible electrode components due to their biocompatibility and non-toxic nature. In this study, pineapple leaf fibers were utilized to create activated biomass carbon aerogel (Bio-CAA). Then, carbon nanotubes (CNTs) were integrated as conductive additives, combined with sturdy pineapple leaf cellulose nanofibers (CNFs) to establish a robust 3D framework. Utilizing a one-step self-assembly method, carbon aerogel/carbon nanotube/carbon nanofiber (Bio-CAA/CNT/CNF) flexible composite electrode materials were successfully synthesized. The porous structure of Bio-CAA effectively minimized the aggregation of CNTs, thereby significantly enhancing the electrochemical performance of the electrode material. The characterization indicated that the carbon aerogel composite exhibited a high specific surface area (684.275 m2 g−1) after tablet compression. The material was light yet robust, capable of being bent arbitrarily and recovering its original shape and withstanding 400 Kpa of pressure at an 88 % strain rate, demonstrating excellent mechanical properties. In a three-electrode system, the Bio-CAA/CNT/CNF = 19:1:1 based electrode exhibited a capacitance of 481 F g−1 at a current density of 1 A g−1. The CAA/CNT/CNF = 19:1:1 based solid symmetric supercapacitor (SSC) displayed excellent cycling stability, preserving 91.7 % capacitance after 10,000 cycles at a current density of 5 A g−1. It achieved an energy density of 39.63 Wh kg−1 at a power density of 500 W kg−1. This biomass-derived carbon aerogel-based composite material demonstrates exceptional energy storage capabilities, and its lightweight attributes make it highly suitable for use in flexible displays, wearable devices, and related fields.

Innovations in additive manufacturing of shape memory alloys: Alloys, microstructures, treatments, applications

Exploring shape memory alloys (SMAs) is like diving into a world of material magic, especially when combined with additive manufacturing techniques. This detailed assessment delves into the fascinating realm of additive manufactured SMAs, examining their complex fabrication processes, captivating internal structures, wide-ranging applications, and unique properties. It is remarkable to observe how the combination of metals, particularly nickel and titanium, creates the very essence of SMA's capabilities and various other material combination for novel SMAs. Additional insights are provided regarding how additive manufacturing parameters and appropriate post-treatments can enable these materials to accomplish extraordinary functionalities. These SMAs also possess the ability to recollect and move, demonstrating superelasticity and the capacity to regain their original shape in various capacities. However, there are promising prospects for the development of novel SMA mixtures, enhanced post-treatments methods, and even more intelligent and responsive products with dimensional accuracy and uniformity. This work presents insights on opportunities in industries for resilient materials, ranging from everyday devices to the immense expanse of space and the human body. Even with the advancements, there is still work to be done in continuously improving their design and pocket comfort. This review not only presents information but also envisions a future in which additive manufactured SMAs are central to advancements in engineering and other fields.

The effect of forming conditions and treatment process applied to the material on springback

Abstract Heat treatment is often used to optimize the balance between the strength and formability of a material. However, aging during treatment affects the ability to return to its original shape after deformation. In this study, the effects of surface treatments during the painting of mild steel and aging time in the W-temper heat treatment on springback were investigated. Consequently, because of artificial aging during surface treatment, the material precipitates certain phases and enhances the mechanical properties of the material, which leads to the pre-painted mild steel being more sensitive to springback. On the other hand, it is also noted that springback is highly dependent on the transfer time between the W-temper heat treatment of high strength aluminum alloy and forming operations, and the change in shape increases with time. In summary, the springback phenomenon is a result of the interaction between the material properties, treatment procedures, and forming circumstances.

Elasticity in Daily Life: A Potential Topics in Learning Physics

As a branch of natural science, physics explores the fundamental properties of matter and energy and their interactions. This study specifically examines the concept of elasticity—the ability of an object to return to its original shape after removing an external force—and equilibrium, which are crucial in understanding various physical phenomena. The research aims to highlight the practical applications of elasticity and equilibrium principles in daily life across multiple fields. Additionally, it seeks to underscore the importance of physics education in preventing misconceptions about these fundamental concepts. The findings suggest that effectively applying elasticity and equilibrium principles can enhance problem-solving in everyday scenarios. However, there is a critical need to improve physics education, particularly in literature and practical simulations, to mitigate common misconceptions and enhance understanding.

A Power Law Reconstruction of Ultrasound Backscatter Images

Ultrasound B-scan images are traditionally formed from the envelope of the received radiofrequency echoes, but the image texture is dominated by granular speckle patterns. Longstanding efforts at speckle reduction and deconvolution have been developed to lessen the detrimental aspects of speckle. However, we now propose an alternative approach to estimation (and image rendering) of the underlying fine grain scattering density of tissues based on power law constraints. The key steps are a whitening of the spectrum of the received signal while conforming to the original envelope shape and statistics, followed by a power law filtering in accordance with the known scattering behavior of tissues. This multiple step approach results in a high-spatial-resolution map of scattering density that is constrained by the most important properties of scattering from tissues. Examples from in vivo liver scans are shown to illustrate the change in image properties from this framework.

2D material-enhanced multi-fold self-sensing and programmable deployable lattice structure

The development of intelligent and programmable smart composite structure that can remember and restore their original shape after being extensively deformed is highly sought after for a wide variety of applications, such as deployable and morphing structures, soft robots, and smart infrastructure. Despite recent advancements, there remains a plethora of unexplored possibilities in the field of deployable structures utilizing shape programmable and intelligent composite materials. The aim of this research is to manufacture a deployable structure that is intelligent enough to monitor the deployment and programmable to be deployed in specific way. Here, a smart deployable auxetic structure is reported that not only possesses thermal and piezoresistive sensing properties but also acts as a thermally activated intelligent shape memory polymer composite (iSMPC). We have fabricated an intelligent fabric and embedded it as reinforcement within a polyurethane-based shape memory polymer matrix to make an intelligent auxetic (A-iSMPC) structure. It has been demonstrated that the intelligent fabric enhances the overall mechanical properties of the auxetic structure and allows monitoring the temperature variation and strain changes during shape programming and recovery. The A-iSMPC offered a negative Poisson’s ratio of − 0.44, shape recovery ratio of 96%, shape fixity ratio of 88% and compaction ratio of 62%. With its shape memory, auxetic, thermal and piezoresistive sensing capabilities, this iSMPC has the potential to be a multifunctional and multipurpose structure for a variety of applications.

Extraction and purification of Pongame oiltree essential oils enhanced the anti-biofilm activity against biofilm-forming Acinetobacter baumannii

In the present study, plant essential oils were successfully extracted from the medicinal plant Pongame oiltree (P. oiltree) using the hydrodistillation method and found to possess excellent anti-biofilm properties against biofilm forming Acinetobacter baumannii (A. baumannii). GC-MS analysis confirmed the presence of all the essential oils in the crude P. oiltree extract. The agar well diffusion method of crude and HPLC purified fraction of the essential oils were showed anti-virulence behaviour instead of anti-bacterial activity. The anti-virulence metabolites were separately purified and confirmed by analytical HPLC. Subsequently, the minimum biofilm inhibition concentration and maximum biofilm inhibition concentration of the P. oiltree essential oils indicated 96 % biofilm inhibition against A. baumannii. In addition, the internal pathogenicity inactivation due to the HPLC purified essential oils was confirmed by inhibition of exopolysaccharide. The architectural biofilm damage with increased death cells and compromised external morphology with loss of original shape was validated by confocal laser scanning electron microscope and scanning electron microscope analysis. Overall, the present study suggests that the HPLC purified fraction of P. oiltree essential oils are an effective anti-biofilm agent against drug-resistant A. baumannii, and it is a future alternative drug discovered option to fight against biofilm-forming bacteria.

Positivity-Preserving Rational Cubic Fractal Interpolation Function Together with Its Zipper Form

In this paper, a novel class of rational cubic fractal interpolation function (RCFIF) has been proposed, which is characterized by one shape parameter and a linear denominator. In interpolation for shape preservation, the proposed rational cubic fractal interpolation function provides a simple but effective approach. The nature of shape preservation of the proposed rational cubic fractal interpolation function makes them valuable in the field of data visualization, as it is crucial to maintain the original data shape in data visualization. Furthermore, we discussed the upper bound of error and explored the mathematical framework to ensure the convergence of RCFIF. Shape parameters and scaling factors are constraints to obtain the desired shape-preserving properties. We further generalized the proposed RCFIF by introducing the concept of signature, giving its construction in the form of a zipper-rational cubic fractal interpolation function (ZRCFIF). The positivity conditions for the rational cubic fractal interpolation function and zipper-rational cubic fractal interpolation function are found, which required a detailed analysis of the conditions where constraints on shape parameters and scaling factor lead to the desired shape-preserving properties. In the field of shape preservation, the proposed rational cubic fractal interpolation function and zipper fractal interpolation function both represent significant advancement by offering a strong tool for data visualization.