Simple Materials Research Articles

An approach to the mechanics of pantographic structures through swarm dynamics

This work concerns mechanical systems known as “pantographic structures”, which are considered a family of beams connected by pivots. We propose a computationally efficient and predictive model capable of providing a plausible description of deformation, using a discrete two-dimensional (2D) “kinematic” model. This model assigns the displacements of certain points, called leaders, while the other points, called followers, are left free to rearrange themselves according to the lattice structure and assigned flocking rules. The advantages of the kinematic model include savings in calculation time and easier handling of complicated structures and fracture phenomena. Moreover, extending the model to encompass non-local interactions, as exemplified by second-gradient materials, is a more straightforward process than solving partial differential equations. The model has previously been employed to elucidate the behaviour of simple materials. The principal innovation of this paper is the essential delineation of the constraint between the pantograph beams, which is contingent upon the presence of the pivot. This was accomplished by imposing an ”average” displacement on the component points of the pivot belonging to two separate beams, thereby introducing an additional parameter into the model. This also necessitated a significant alteration to the calculation algorithm. The model is still constrained by several limitations, including the absence of a physical interpretation for its parameters and the necessity of connecting it to the CUDA (Compute Unified Device Architecture, by NVIDIA) architecture for the calculation of the developed algorithm. The principal limitation of the present approach, however, is the absence of a correlation between the parameters of the ’kinematic’ model and the constitutive parameters of the material. This aspect will be the subject of future research.

High-temperature (800 °C) performance of spodumene slag-based ternary sulphate composite phase change materials with improved mechanical property

The large deployment of electric vehicles leads to decarbonised road transport. However, the mining and smelting of lithium resources will continue to increase, which generates lithium slag and urgently needs to be recycled. The integration of spodumene slag with ternary sulphate presents a green and promising approach to achieve resource recycling and high-performance composite phase change material (CPCM). Herein, toughened and strengthened CPCMs are prepared by the hybrid sintering method with mechanical properties better than reinterned glass, even after high-temperature thermal cycling. After the cold compression and hot sintering process, the production of colloidal sodium silicate bonds the ternary sulphate with the spodumene slag skeleton, which greatly enhances the strength of the CPCM for efficient and durable thermal energy storage (TES). The Hydroxyl polar group of sodium silicate interacts with the skeleton and leads to a record-breaking compressive strength of 155.23 MPa, and the CPCM can support its stacking of 23.6 m and 15 kg loading test at 700 °C. A negligible mass loss of 0.26 wt% was observed after 50 thermal cycles at 800 °C. Moreover, the CPCMs exhibit a high TES density of up to 873.0 J/g in the temperature range of 100–800 °C. High charging and round-trip efficiency in the heat recovery process from spodumene roasting is also achieved, as it is 5 % and 19 % higher than the common magnesium bricks, respectively. The CPCM achieves high thermal efficiency TES, and it is the effective resource recycling of lithium slag with simple material preparation, which, from two angles at once, attacks the carbon emission from the life cycle of the lithium-ion battery.

Divacancy graphene and graphyne as potential biomedical sensors: A first-principles study

Imbalance in the levels of hydrogen peroxide signals the onset of chronic diseases in our body. Thus, it becomes imperative to design simple material systems with single molecule sensitivity. In this study, we investigate graphene and graphyne based systems by including various vacancy structures to assess their potential as H2O2 sensor materials. From the computed adsorption energies, we select two promising candidates, interestingly both are divacancies in graphene and graphyne. We then investigate electron transport in both the systems using the DFT-NEGF approach. Upon adsorption of H2O2 on the 585 vacancy (a special case of divacancy) in graphene and divacancy graphyne monolayers, we observe distinguishing current-voltage and electron transmission characteristics, in particular, in the former. For the 585 divacancy graphene system through analysis of the electronic properties, we identify the underlying mechanisms responsible for the difference in current values between the clean and H2O2 adsorbed systems, and hence its sensing ability. This work opens up a new avenue of intelligently incorporating vacancy defects in cheaper carbon-based 2D materials to effectively serve as potentially highly sensitive and selective biosensors for early disease detection.

High performance plain carbon steels obtained through 3D-printing

Over the last century, improvement in mechanical performance of structural metals has primarily been achieved by creating more and more complex chemical compositions. Such compositional complexity raises costs, creates supply vulnerability, and complicates recycling. As a relatively new metal processing technique, metal 3D-printing provides a possibility to revisit and simplify alloy compositions, achieving alloy plainification, which enables simpler materials to be used versatilely. Here, we demonstrate that high performance simple plain carbon steels can be produced through 3D-printing. Our 3D-printed plain carbon steels achieve tensile and impact properties comparable, or even superior to those of ultra-high strength alloy steels such as Maraging steels. The sequential micro-scale melting and solidification intrinsic to 3D-printing provides sufficient cooling to directly form martensite and/or bainite, strengthening the steels while maintaining microstructural and property homogeneity without dimensional limitations or heat treatment distortion and cracking. By manipulating 3D-printing parameters, we can tailor the microstructure, thereby control the properties for customized applications. This offers a scalable approach to reduce alloy complexity without compromising mechanical performance and highlights the opportunities for the 3D-printing to help drive alloy plainification.

Theoretical study of solvent effects on the white light emission mechanism of single molecule 4-OH-naphthalimide

Organic white light materials fabricated on the basis of single molecules have applied to manufacture the white light-emitting diodes due to their good photostability and relatively simple material preparation. In this work, the different fluorescence emission mechanisms of the NapH1 in n,n-dimethylformamide (DMF) and toluene are investigated to elucidate the process for generating single-molecule near-white-light. From the analysis of bond lengths and electrostatic potential analysis, the intermolecular hydrogen bond can form in DMF instead of in toluene. From the potential energy curves, it is clear that intermolecular proton transfer is not feasible in either DMF or toluene. Frontier molecular orbitals analysis, the dissociation constants and the vertical excitation energies are used to confirm that NapH1 can undergo the deprotonation process in DMF rather than in toluene. Combined with the calculations of the fluorescence values, only the original structure exists stably in toluene which emits blue fluorescence. And the dual fluorescence peaks of NapH1 in DMF are originated from the enol form and the deprotonated form, interacting jointly to emit near-white light. This work contributes to the investigation and advancement for single-molecule organic white luminescent materials.

The Effect of Convenience, Attractiveness, and Motivation on the Effectiveness of Online and Offline BIPA Learning Based on Teacher Perceptions

Teachers must create an engaging, convenient, and motivating learning environment to ensure the effectiveness of both online and offline BIPA learning. This research aims to identify the characteristics of BIPA (Indonesian Language for Foreign Speakers) teachers and analyze the differences in the levels of effectiveness, attractiveness, motivation, and convenience experienced by teachers during offline and online learning. Furthermore, this research examines the impact of Convenience (ease of access and flexibility), Attractiveness (appeal of content and methods), and Motivation (strategies to inspire engagement) on the overall Effectiveness of BIPA learning based on teacher perceptions. The study finds that Convenience, Attractiveness, and Motivation significantly influence the overall Effectiveness of both online and offline BIPA learning. Additionally, this study seeks to identify strategies teachers employ to foster interest and motivation among BIPA students in both learning modes. This study employs a cross-sectional research design with 100 BIPA teachers as respondents. Data were analyzed using descriptive statistics and partial least squares structural equation modeling (PLS-SEM). The findings indicate that BIPA teachers are generally Indonesian citizens with less than one year of online teaching experience. The study reveals that the attractiveness, convenience, and effectiveness levels are higher offline than online learning. Moreover, attractiveness has a significant positive effect on effectiveness. Field trips are vital activities that generate interest and motivation in offline learning, while simple materials and applications are pivotal in online learning. This research highlights the positive aspects and activities undertaken by BIPA teachers to enhance the effectiveness of online and offline learning.

A novel label free electrochemical aptasensor based on poly(anthranilic acid-co-aniline) for detection of miRNA-155, a cancer biomarker

Traditional electrochemical biosensors often rely on expensive materials like gold nanoparticles within their electrode structures. In contrast to existing methods, this research introduces a novel, groundbreaking, label-free aptasensor. This sensor comprises simple and inexpensive materials, making it accessible and budget-conscious. It boasts exceptional sensitivity, allowing for the identification of leukemia cancer biomarker (miRNA-155) in its early stages. The proposed aptasensor consisted of a copolymer of poly anthranilic acid and polyaniline on the graphite sheet, in which the receptor of miRNA-155 was self-assembled on the copolymer. The substrate of receptors has benefits, including high electrical conductivity, excellent stability, good biocompatibility, and simple synthesis. The important variables affecting the adequacy of the designed aptasensor were examined in the presence of [Fe(CN)6]3-/4- as a redox probe. The proposed aptasensor was successfully used in human blood plasma. Due to the ease of preparation, cost, and time effectiveness, the proposed aptasensor is promising for mass production. Finally, at optimum conditions, the sensor exhibited a linear response within a concentration range of 0.1 nM to 1 aM with a detection limit of 1 aM.

Metal organic framework derived composite as a new sorbent for micro-solid phase extraction of parabens from breast milk samples

In an attempt to enhance the adsorptive properties while addressing the limitations associated with powdered nature, zeolitic imidazolate framework (ZIF-67)-derived cobalt-doped nanoporous carbon (Co-NPC) was incorporated into chitosan and then shaped like hollow fiber by a simple casting method. Further modification with polyaniline (PANI) was also performed to improve extraction efficacy. The applicability of the modified hollow fibers was then investigated by packing them into a cartridge and utilizing them for conducting hollow fibers-packed in-cartridge micro solid-phase extraction (HF-IC µ-SPE) of parabens including methylparaben (MP), ethylparaben (EP), and propylparaben (PP) from human breast milk samples. Factors affecting extraction performance were studied using central composite design (CCD). Under the optimal conditions, good linearity was achieved within the range of 0.5–500 μg L−1 with the determination coefficient (R2) higher than 0.9901. All analytical parameters were obtained by liquid chromatography-tandem mass spectrometry (LC–MS/MS) analysis. In this regard, the limits of detection values (LODs) were 0.5 to 1.0 μg L−1. Intra- and inter-assay precision RSDs % were lower than 7.9 % and 8.4 %, respectively. Relative recoveries of breast milk samples were found in the range of 88.0–109.5 %. Accordingly, the novel nanocomposite sorbent based on PANI@Co-NPC/Chitosan hollow fiber was found to be an efficient, simple, and cost-effective packing material for HF-IC µ-SPE. It can also be offered as a promising alternative adsorbent to coated conventional hollow fiber.

Non‐linear time history analyses of a rigid block isolated with unbonded fiber‐reinforced elastomeric isolators (UFREIs): A comparison between 3D finite element and phenomenological models

AbstractNumerical modeling represents a pivotal tool in the seismic analysis and design of structural systems, enabling the detailed prediction and examination of structural responses under seismic loading. This research conducts a comparative analysis of two numerical modeling approaches aimed at simulating the seismic response of unbonded fiber‐reinforced elastomeric isolators (UFREIs). The research focuses on a finite element (FE) model developed using Abaqus and a developed phenomenological model implemented in OpenSees, outlining the development and calibration processes for each. The FE model is developed based on simple rubber material testing data, while the phenomenological model is calibrated using experimental results from cyclic shear tests conducted on the UFREI device and the FE model. The primary objective of this study is to assess the effectiveness of these modeling approaches in predicting UFREI behavior under seismic conditions. This evaluation entails comparing model predictions with experimental data obtained from unidirectional shake table tests performed on a rigid block isolated by two UFREIs. This paper highlights the distinct advantages and limitations of each model in simulating UFREI dynamic responses during seismic events. Furthermore, it provides insights into the modeling techniques and discusses the computational demands and data requirements of each model, thereby aiding in their application to various aspects of seismic analysis and design.

Ullmann coupling reaction of dihalobenzenes and malononitrile-heterocumulene adducts under ultrasound-irradiation

In this study, various benzothiazoles, benzoxazoles, and benzo[1,3]-dithiols derivatives with good yields were obtained using the Ullmann coupling reaction of dihalobenzenes and malononitrile-heterocumulene adducts in the vicinity of copper catalyst, Cs2CO3 as a base under ultrasound irradiation. The use of the popular sonochemical method, short reaction time, simple and available raw materials, mild catalytic copper reaction conditions, simple purification, and good efficiency are some of the notable characteristics of this protocol.

Lattice Structures-Mechanical Description with Respect to Additive Manufacturing.

Lattice structures, characterized by their repetitive, interlocking patterns, provide an efficient balance of strength, flexibility, and reduced weight, making them essential in fields such as aerospace and automotive engineering. These structures use minimal material while effectively distributing stress, providing high resilience, energy absorption, and impact resistance. Composed of unit cells, lattice structures are highly customizable, from simple 2D honeycomb designs to complex 3D TPMS forms, and they adapt well to additive manufacturing, which minimizes material waste and production costs. In compression tests, lattice structures maintain stiffness even when filled with powder, suggesting minimal effect from the filler material. This paper shows the principles of creating finite element simulations with 3D-printed specimens and with usage of the lattice structure. The comparing of simulation and real testing is also shown in this research. The efficiency in material and energy use underscores the ecological and economic benefits of lattice-based designs, positioning them as a sustainable choice across multiple industries. This research analyzes three selected structures-solid material, pure latices structure, and boxed lattice structure with internal powder. The experimental findings reveal that the simulation error is less than 8% compared to the real measurement. This error is caused by the simplified material model, which is considering the isotropic behavior of the used material PA12GB (not the anisotropic model). The used and analyzed production method was multi jet fusion.

Utilization of Artificial Intelligence to Improve Equitable Healthcare Access for Breast Implant Patients

Abstract The recently mandated US Food and Drug Administration (FDA) patient decision checklists were developed with the goal of improving the informed decision-making process for patients considering breast implants. Yet, prior research has demonstrated that these checklists are written at reading levels far in excess of that recommended by the National Institutes of Health and the American Medical Association. Patients considering breast implants are required to sign these forms prior to surgery, even if they have little to no comprehension of their contents. This study aims to improve the accessibility, and therefore the utility, of the mandated FDA patient literature using the assistance of artificial intelligence (AI). Patient decision checklists were obtained from the three most utilized breast implant manufacturers in the United States– Allergan, Mentor, and Sientra. AI was then asked to synthesize a novel patient decision checklist, written at the 6th grade reading level, using these checklists as source material. The AI-assisted checklist was edited by plastic surgeons for both formatting and content. Readability analysis of all documents was performed using the Flesch Reading-Ease Score, Flesch-Kincaid Grade Level, Gunning-Fog Index, Coleman-Liau Index, Simplified Measure of Gobbledygook, and Automated Readability Index. Textual analysis included sentence count, word count, number and percentage of complex words, average number of words per sentence, and average number of syllables per word. The overall readability of Allergan, Mentor, and Sientra patient checklists correlated with the college reading level. These documents were of a statistically significantly higher reading level the AI-assisted checklist, which was written at the recommended 6th grade level. Text composition analysis similarly demonstrated substantial differences between the AI-assisted and FDA mandated literature. The currently mandated breast implant patient checklists are written at a college reading level and are inaccessible to the average patient. We propose a new patient decision checklist, generated with the assistance of artificial intelligence, in order to improve healthcare access within plastic surgery. This simplified material can be used as an adjunct to the current checklists in order to improve shared decision making.

Recent Advances on the Construction of Functionalized Indolizine and Imidazo[1,2-a]pyridine Derivatives.

Indolizines and imidazo[1,2-a]pyridines are commonly found in natural products, synthetic drugs, and bioactive molecules. These two types of derivatives possess good antibacterial, antiparasitic, anticancer activities, and so on. The functionalization of indolizines and imidazo[1,2-a]pyridines has always been a hot topic in organic chemistry research and has made significant progress. In recent years, our group has been dedicated to developing diverse synthetic methods for the preparation of such important compounds. 1) We have developed diverse C-H functionalization reactions for efficient modification of the parent indolizines and imidazo[1,2-a]pyridines. 2) A variety of cycloaddition reactions were established for the construction of indolizine and imidazo[1,2-a]pyridine derivatives from simple raw materials. 3) We have developed intriguing deconstruction-functionalization reactions of indolizines, enabling the reorganization of heterocyclic frameworks. This paper outlines our group's latest advancements in constructing structurally diverse indolizine and imidazo[1,2-a]pyridine derivatives. We hope that this work will offer valuable insights and inspiration for the ongoing research in the field of N-heterocyclic compounds.

Access to 2-Oxabicyclo[2.1.1]hexanes and their use in Scaffold Hopping.

Saturated isosteres of the ortho-substituted benzene ring remain rare due to the paucity of methods to access complex bridged systems. Using blue-light-mediated [2 + 2] photocycloaddition chemistry, we have developed a quick and practical route to provide novel 2-oxabicyclo[2.1.1]hexanes from simple feedstock materials in only three steps. Matched pair analysis confirmed that this motif could prove useful in the future to the drug discovery community as a scaffold endowed with remarkable properties.

Uncovering the universe of New Psychoactive Substances (NPS): Understanding the mechanisms of action and adverse effects in an accessible and didactic way

New Psychoactive Substances (NPS) constitute a heterogeneous group of drugs associated with a range of health harms, producing more intense effects than traditional drugs. NPS pose a challenge for public health policies due to the limited information available about their effects on the body. Understanding the primary effects of NPS and their mechanisms of action is crucial for guiding healthcare professionals and raising awareness about the dangers associated with their use. In this context, the aim of this study was to gather the most current scientific information on the mechanisms of action and adverse effects of NPS, transforming it into a simple and accessible educational material for the public. Based on the information collected in this review, it was possible to develop a playful educational tool that not only informs about the effects of NPS but also provides clear information about the mechanisms of action of these substances in the CNS, as currently known for the wide variety of NPS. By making this information accessible and understandable, the booklet contributes to public awareness and empowers individuals to make informed and responsible decisions about the use of psychoactive substances. Additionally, it serves as a valuable educational tool for healthcare professionals and educators.

Penerapan Media Postcard untuk Meningkatkan Keaktifan Siswa SMK Ma’arif NU Kajen Tahun 2021/2022

The learning model applied during the COVID-19 pandemic has changed the way students learn, so that student activity in the learning process in class is still low and there are many student absences after the pandemic. Almost 2 years of the pandemic have required students to study from their respective homes so that students are increasingly lazy or less active in learning. This is the basis for the idea of ​​how to make them more effective in learning by using postcard media. Postcard media is a media containing questions related to learning that must be answered by students by taking lucky coupons. The purpose of this study is 1) To describe the teacher's process in implementing postcard media in building student activity in learning in class XI of SMK Ma'arif NU Kajen. 2) To analyze the level of student activity of class XI of SMK Ma'arif NU Kajen through the application of postcard media in learning. This classroom action research was conducted at SMK Ma'arif NU Kajen with the research subjects of class XI students totaling 72 students with almost the same academic abilities, able to understand simple materials, but the level of student activity is low, the majority are less brave in expressing ideas, ideas and opinions. Data collection techniques include questionnaire sheets and documentation. Data analysis used is qualitative and quantitative data analysis. The results of the study showed that the process of implementing postcard media which was carried out through three stages, namely the process of designing a learning plan, the process of implementing learning, and the process of evaluating the use of learning media has been implemented well by teachers. In cycle I, the results of the questionnaire showed that the application of postcard media to increase student activity was successful with an average score reaching 86%. In cycle II, the application of postcard media to increase student activity was successful with an average questionnaire score reaching 88%. Postcard media has proven to be effective in increasing student activity in learning. For teachers, it is expected to be able to improve learning media so that students can be encouraged to be active in class. For schools, it is expected to be able to provide adequate facilities, especially the provision of teaching aids so that teachers can be more free in creating a creative learning process.

Far transfer of retrieval-practice benefits: rule-based learning as the underlying mechanism.

Benefits of self-testing for learning have been consistently shown for simple materials such as word lists learned by rote memorization. Considerably less evidence for such benefits exists for complex, more educationally relevant materials and its application to new situations. The present study explores the mechanisms underlying this transfer. To this end, a typical retrieval-practice-effect paradigm was applied to foster the learning of an artificial language. Participants either repeatedly studied grammatically correct exemplar sentences of the artificial language or engaged in a cloze test as the interim testafter learning. To assess far transfer, participants in both groups of restudy and retrieval practice engaged in a grammaticality judgment test after a delay of 5min and 1week. In addition, participants in both groups completed a final memory test (i.e., a cloze test identical to the initial test) 1week after learning. In addition to a long-term memory benefit of retrieval practice,results revealed alsoa retrieval-practicebenefit in the far-transfer test after the 1-week delay. The findings further support the view that far transfer is supported by learning the underlying grammatical rules as opposed to memorizing the material. Thus, retrieval practice is also effective for fostering learning of complex materials and, even more importantly, for promoting transfer of learning-a crucial goal in modern educational practices.

Impact of surrounding environment on impinging supersonic jets resonances and their hysteretical behavior

Supersonic jets impinging on flat surface produce intense acoustic tones. Recent measurement campaigns have indicated that the surrounding environment geometry or its acoustic treatment can drastically change the observed resonance frequencies and amplitudes at identical flow regimes. For example, at supersonic speeds, a hard walled external nozzle shape leads to the existence of two main types of resonances: antisymmetric resonances (with frequencies close to the free jet screech) and axisymmetric resonances. Frequencies associated to those different resonances are very distinct. We have observed that Applying a simple non-reflective material to the outer surfaces of the nozzle suppresses the axisymmetric resonances and that antisymmetric resonances seems to be contained in the frequency range of existence of trapped acoustics modes, known to be responsible for screech resonances. Additionally, when no acoustic treatment is applied on the nozzle wall, the experiments show that the switch between different resonance regimes (symmetric - antisymmetric), induced by changes in Mach number, has an hysteretical behavior. To the authors' knowledge, this has been rarely discussed in the literature and adds to the actual complexity of the aeroacoustic behavior of such jet flows, especially when modeling is considered.

Fostering prospective teacher-students to contextualize blackbody radiation in astrophysics

Abstract In astrophysical concepts, a star can be treated as a blackbody. However, teaching blackbody radiation in physics classrooms is not often relevant to astrophysical contexts. Therefore, prospective teacher-students need to have experiences contextualizing blackbody radiation in astrophysics. This study aimed to investigate how the inquiry lesson activities for teaching blackbody radiation in an astrophysics context, including the design of a simple experimental setup and the worksheets. The experimental setup was designed using affordable equipment like a tungsten bulb, a basic meter, a small piece of compact disk, and a smartphone application called lux meter. By manipulating the voltage across the tungsten filament and measuring the current and intensity using a lux meter, students can calculate its temperature, analyze the spectrum through PHET simulation, and construct a graph of wavelength vs intensity. The method of this study combines a qualitative analysis to describe the resulted spectral by the apparatus, lesson design, and description of the implementation. In addition, quantitative analysis using a quasi-experimental one-group pre-test and post-test design was conducted with prospective teacher-student participants who had taken the astronomy course and are still taking the modern physics course. The results show that inquiry lesson using simple apparatus model and materials positively fosters prospective teacher-students understanding of how to contextualize the blackbody radiation concept in astrophysics.

Design, Synthesis and Biological Evaluation of Novel Capsaicin Analogues Containing Heterocyclic Fatty Acids

AbstractThere is an urgent need to study safe and biocompatible medicinal compounds which necessitates the discovery of new agents from simple natural starting materials. In this study, eight novel capsaicin derivatives have been synthesized by combination of oxadiazole containing fatty acids with vanillyl amide. All the compounds were characterized by spectral analysis and were examined for their cytotoxicity, antimicrobial, antioxidant and anti‐inflammatory properties. The antioxidant activity of the synthesized derivatives was evaluated by 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH) and thiobarbituric acid reactive substances (TBARS) assays. All of the synthesized derivatives have exhibited significant antioxidant activity in comparison to butylated hydroxy toluene (BHT) which is used as a reference antioxidant. The novel capsaicin derivatives with nitro (8 e) and methoxy substituents (8 f, 8 g and 8 h) exhibited the most significant antioxidant activity compared with BHT. In cytotoxicity assay against three cell lines, the derivative with bromo substituent showed excellent activity against B16‐melanoma cancer cell line followed by nitro and methoxy analogs which showed promising activity against HepG2‐ hepato and DU145‐prostate cancer cell lines respectively. In addition, all the derivatives exhibited moderate broad spectrum antibacterial, antifungal and anti‐inflammatory activity.