Macromolecular Symposia最新文献

This article examines coplanar waveguide (CPW)-fed flame-retarded FR-4 woven fiberglass laminated antenna design methods and how to optimize electrical parameters, including impedance bandwidth, return loss, and gain. In this article, a comparative examination of different design strategies that can be employed in the CPW-fed antenna, including adding stubs, slots, notch bands, metamaterials, frequency selective surfaces (FSS), and CPW-fed multiple-input-multiple-output (MIMO) antennas, is investigated. In the proposed work, meander line effects are explored on the electrical parameters of CPW-fed FR-4 woven fiberglass-laminate antennas. These design methods and their effects on antenna electrical parameters are also examined.

Fluorotelomers (FT) are a class of perfluoroalkyl substances (PFAS) that have a variety of applications due to their unique chemical properties. However, fluorotelomers and some of their breakdown products have raised environmental and health concerns due to their persistence, bioaccumulation, and potential toxicity. Hence, its removal from industrial waste is essential. In this study, anion exchange resin as an adsorbent is investigated for fluorotelomer olefin (FTO) removal. Three different parameters are investigated: adsorbent dosage, contact time, and initial concentration of FTO. The effects of other compounds on FTO removal are also investigated. The surface morphology and surface area of anion exchange resin are also conducted using a scanning electron microscope (SEM) and Brunauer–Emmett–Teller (BET), respectively. The surface of anion exchange shows smooth and fractured structure with 2.0381 mg² g⁻¹ surface area. The results show fast and high removal of FTO up to 80% using optimum sorption condition (1.25 mg, 5 h, and 400 mg L⁻¹). In addition, the removal efficiency of FTO is not affected by the presence of other interference compounds. The understanding of FTO removal through anion exchange resin offered by this work should lead to more effective applications for fluorotelomers removal from the environment.

Propolis has the potential to serve as an alternative coating for coconut leaves, given its antimicrobial qualities attributed to compounds such as flavonoids and phenolic acids. The objective of this research is to assess the antibacterial activity of coconut leaf-based packaging coated with propolis. Specifically, 3% concentrations of two types of propolis from different regions, namely Indonesia (A) and Brazil (B), are chosen as coating materials for the coconut leaves. It chooses a 3% propolis concentration for the coating based on a preliminary test. The application of the coating influences the thickness of the leaves, ranging from 0.39 to 0.41 mm, and results in a color change (∆E) ranging from 23.95 to 28.06. The enhancement of antimicrobial features against Bacillus subtilis and Escherichia coli is more pronounced in propolis B-coated leaves (9.84 mm for B. subtilis; 13.22 mm for E. coli) compared to propolis A-coated leaves (8.94 mm for B. subtilis; 12.28 mm for E. coli), as observed through the inhibition zone test.

The research involves the preparation of 2–hydrazinobenzoimidazole (N1) from the reaction of the compound 2-tetrabenzoimidazole with aqueous hydrazine. A number of hydrazones (N2, N3) are prepared by the reaction of the compound (N1) with benzaldehyde derivatives. Thiazolidinone (N4) is also prepared by cyclization of the hydrazone compound (N3) using thioglycolic acid. As for the compound (N5), it is obtained from the reaction of the compound 2-mercaptobenzimidazole with ethyl chloroacetate in the presence of alcoholic potassium hydroxide. The newly synthesized compounds show a very good interaction through the docking score compared to co-crystalline ligand of each protein and in the same time the docking score is better than approved antibiotic in some cases. Furthermore, the study concluded that the compound N2 displayed the best and safest docking specifications out of all the compounds.

A 90 nm NMOS MOSFET model is simulated using Silvaco Visual T-CAD simulator. The materials used to simulate NMOS MOSFET are Al, Si, NpolySi, and SiO2. To overcome the problem of short circuits, lightly-doped drain (LDD) implantation is applied in NMOS model. The analysis of the model is determined with T-CAD simulator and obtained threshold voltage (V_th) 2.568 V, while keeping oxide thickness (T_ox) 2.373 nm and gate length 0.09 µm. The obtained result is compared with standard ITRS road map and gets almost similar results.

Polymer materials are an important part of everyday life, it is imperative to examine their properties, diverse applications, and their impact on the life of an individual. Polymers are vital in daily experiences from medical devices to household items. This study explores the characteristics of polymers that make them useful for various applications, emphasizing their adaptability, robustness, and affordability. The environmental aspects of polymer consumption are also covered, covering the difficulties and developments in sustainable polymer development. All things considered, this study clarifies the crucial part of polymer materials that play in improving and forming the standard of daily lives. This study also aims to find the recent as well as future developments in the field of polymers.

3D polymer printing and multimedia represent cutting-edge technologies that have become integral parts of our modern world. While 3D printing reshapes the physical realm by redefining how objects are manufactured, multimedia transforms the digital landscape, influencing how information is presented and consumed across diverse domains. 3D polymer printing, known for its layer-by-layer additive manufacturing process, has found a symbiotic relationship with multimedia, integrating visual, auditory, and interactive elements into the 3D printing realm. The research paper discusses how current and future 3D polymer printing can assist media industry through enhanced learning, interactive education experience, customized content, augmented and virtual reality, film and animation industry, as well as promotion of environmentally friendly practices. The versatility of 3D polymer printing has led to its widespread adoption across diverse industries, offering new possibilities in design, prototyping, and production. The tangible and interactive nature of 3D-printed objects enriches multimedia content across various industries.

Poly(vinyl alcohol)-based polymer electrolyte films doped with ionic liquid 1-ethyl-3-methylimidazolium tricyanomethanide (EMIMTCM) were prepared by the solution casting method. The structural characterization has been done with polarized optical microscopy and differential scanning calorimetry. Incorporation of ionic liquid shows the decrease in crystallinity in polymer matrix with an increase wt% of ionic liquid, which is confirmed with differential scanning calorimetry and polarized optical microscopy. The prepared samples were subjected to electrochemical impedance spectroscopy to measure the ionic conductivity and the dielectric constant. Electrochemical stability voltage measurement confirms the prepared polymer electrolyte film is stable up to 3.99 V, and the ionic transfer number was calculated by Wagner's polarization method, which confirms the ionic nature of prepared polymer electrolyte films.

The authors develop an inventory model for high-tech materials like those used in smartphones and electronics, and so on, where demand grows exponentially and the deterioration rate is constant. Holding costs increase linearly with time, and shortages are managed with partial backlogs. Their primary aim is to maximize total profit through this model, analyzing how changes in parameter values impact this objective. A numerical example illustrates sensitivity analysis, with graphs showing the connections among model parameters, economic order quantity (EOQ), optimal timing, and total profit.