Semiconductors are integral to wide array of daily activities like mobile phones and modern automobiles. With rapid advancements in the electronics industry, electronic devices are evolving towards miniaturization. This evolution drives to downsizing the existing semiconductor packages and imposes higher requirements on the quality and reliability of solder joints.

This study focuses on assessing the interfacial reactions between Sn-based solder and die-backside metallizations (BSM), Ti/Ni/Ag and Ti/Al/NiP. The dice with Ti/Al/NiP BSM underwent two processes: increased backside surface roughness and increased backside Aluminum content. They were assembled onto two distinct AMB substrates: Cu-exposed and Ni-plated.

Various intermetallic compounds (IMC) were identified near the die/solder interface. They were characterized using SAM, supplemented by mechanical cross-sectioning technique, SEM, and EDX.

The results show that the Ti/Ni/Ag BSM leads to the formation of fully fragmented IMC. The Ni-plated AMB substrate results in thinner IMCs compared to the Cu-exposed AMB. Increased die-backside roughness leads to a discontinuous IMC layer, while higher Al content promotes a thin IMC with scalloped and needle-like extensions. The SnAg₅ solder results in IMCs with distinct appearance compared to SAC305 due to its initial content of Cu. Finally, thermal cycling induces heterogeneous coarsening of IMCs, and formation of cracks and delamination at the interface and within the solder.

In conclusion, the study reveals that Ti/Al/NiP BSM provided a more reliable IMC. The increased BS roughness does not represent an optimal approach, this contrasts with the increase in Al content which results in a more favorable structure. The Ti/NiV/Ag BSM leads to highly fragmented IMC detached from the interface with the dispersion of plate-like Ag3Sn IMCs which represent a site for strain localization. Finally, the initial Cu content in SAC305 solder governs the IMC crystal growth.

This research focuses on the computational analysis of polylactic acid (PLA), a biodegradable polymer widely used in 3D printing. A commercial CFD software, Ansys-Fluent, was employed to simulate the extrusion process of PLA and to understand the behavior of the deposited flow under various printing conditions, including printing height, flow rate, and travel speed. An explicit Volume of Fluid formulation was employed. The PLA was characterized based on its density, specific heat, and heat conductivity, all of which were determined to vary with temperature, as reported in the literature. Also, a comparison between Newtonian and non-Newtonian models was carried out to understand their impact on the extrusion process.

The results show that the viscosity model influences the shape of the deposited filament. Also, both travel and extrusion speeds significantly affect the quality and geometric shape of the extruded filament. Specifically, excessive speed leads to a filament width reduction and creates instability, while insufficient extrusion speed affects stability and produces less heat accumulation. Additionally, excessive printing height negatively impacts the stability of the flow and increases solidification time.

In conclusion, the present work shows a promising approach to simulate filament deposition in 3D printing. Future research will focus on validating these results through experimental studies and optimizing printing parameters to achieve high-quality printing with less material waste.

For both residential and commercial buildings, one of the largest portions of the total energy consumption and environmental impact lies within the heating and cooling of the building and the thermal inefficiencies of the building envelope. To meet the Paris Climate Agreement’s goal of reducing global warming by 2 degrees Celsius, the thermal efficiency of buildings should be increased by 30%. Phase Change Materials (PCMs) have been used in gypsum wallboard with great success but have not performed as well in concrete due to the resulting decrease in the concrete’s compressive strength and the survivability of the PCM during mixing and curing. Testing has shown that concrete walls containing PCMs consistently show a 3-degreesCelsius change in temperature compared to similar walls without PCM. This study aims to build upon previous work in the literature and further explore the effect of the water–cement ratio, aggregate content, and PCM content on the thermal and mechanical properties of PCM concrete. The PCM concrete used in the study was composed of Type I cement, silica fume, sand, and 24 degree Celsius microencapsulated dry PCM. The compressive strength of the concrete was measured at 7 days, and the compressive strength and thermal performance were measured at 28 days. The thermal performance was assessed using a radial heat flow method that involved recording the temperature rise in a cylindrical concrete specimen as it was heated using a cartridge heater.

The study of aerodynamics in racing motorcycle prototypes has become an essential phase, significantly enhancing performance during all riding phases. In the present study, three rear fairing winglet proposals for a racing motorcycle prototype were designed and evaluated. The three designs, realized in Siemens NX, were imported into a validated Simcenter STAR-CCM+ CFD (Computational Fluid Dynamics) model. From the analysis of the results, it was observed that the designs had varying impacts on the overall drag and lift values. The design and simulation campaigns conducted allowed for a comprehensive evaluation and appreciation of the aerodynamic functions crucial for vehicle dynamics, such as closing the wake to reduce drag and preventing advantages for following riders. By analysing the aerodynamic performance of each design, this study aimed to identify the configuration that best meets the required dynamic conditions. Furthermore, this study emphasized the importance of having a rear fairing that not only optimizes aerodynamic efficiency but also contributes to the overall stability and control of the motorcycle. Through iterative design and simulation processes, one of the three analysed designs emerged as the most effective solution, providing a balanced combination of reduced drag and improved downforce characteristics essential for competitive racing. Future developments could involve implementing optimization algorithms to further enhance the performance of the best rear winglet design.

This study presents a comparative Life Cycle Assessment (LCA) of two 3D printing technologies: Electron Beam Melting (EBM) and Material Extrusion (MEX) using metal-filled filaments, followed by debinding and sintering processes. The primary goal is to assess the environmental impact of both technologies.

The LCA methodology employed adheres to ISO 14040/44 guidelines. Data were collected from primary and secondary sources, including direct measurements, database information, and scientific literature.

Results indicate that EBM technology, despite its high energy consumption during metal melting, produces higher quality parts with less post-processing required. However, the significant energy impact raises concerns about energy efficiency, particularly in large-scale production contexts.

Conversely, the MEX technology with metal-filled filaments, followed by debinding and sintering, exhibits lower energy consumption during the printing phase and benefits from low operational costs due to the use of conventional 3D printers that are widely accessible and maintainable. Nevertheless, this technology requires additional processing steps that can introduce complexity and variability in the final results. Furthermore, parts produced via MEX generally exhibit lower quality compared to those produced by EBM, necessitating further machining to meet desired standards.

In conclusion, the LCA analysis highlights that the choice of 3D printing technology should be carefully evaluated based on specific project requirements and available resources. EBM technology is more suitable for applications demanding high quality and precision, while MEX with metal-filled filaments offers a more energy-efficient solution, albeit with challenges related to quality and process complexity.

These findings provide a foundation for future research and optimization of 3D printing technologies, contributing to informed decisions for sustainable manufacturing in advanced production sectors.

Surface plasmonic sensors are widely utilized in bioanalytical and diagnostic laboratories to track interactions between analytes and receptors.¹ The primary advantage of plasmonic technology over traditional diagnostic methods is the possibility of label-free monitoring of binding events in real time. However, the expensive chip and the laborious surface chemistries required for functionalization are notable drawbacks.

In this study, a novel sensing approach is introduced to detect receptor-target interactions at extremely low concentrations without any kind of sensing surface functionalization. The biosensor operates using a sensitive chip based on a microcuvette device fabricated by drilling the core of a multimode polymer optical fibre (POF) with nanoholes. This is connected in series with a surface plasmon resonance (SPR) D-shaped POF probe, and the detection is performed using a broad-spectrum halogen lamp and a spectrometer. The microhole is filled with a solution containing specific receptors that selectively capture the target molecules from samples placed on top of the filled nanohole. Any changes over time due to analyte-receptor binding alter the mode profile of the light propagating through the POF core, affecting the plasmonic interactions and resulting in a time-dependent shift in the resonance wavelength.²

In particular, The interactions of estradiol and cortisol, with their respective receptors (Estrogen Receptor³ and Glucocorticoid Receptor⁴) were tested as proof of concept.² The resonance wavelength shift was monitored over time to trace the interactions between the receptor–target pairs at attomolar concentration.²

This advanced sensing approach acts as a new class of laboratory instruments offering distinctive capabilities in ultra-high sensitivity and affordability.

References:

[1] Homola, J et al. Sens. Actuators B Chem. 54 (1999) 3–15.

[2] Cennamo, N et al. Sens Actuators B Chem. 2024, 416, 136050.

[3] Arcadio, F et al. Biosensors 2023, 13, 432.

[4] Arcadio, F et al. Biosensors 2024, 14, 351.

Study aims to evaluate the potential of agrowaste, specifically cabbagepeels and bananatrunks, as adsorbents for removing heavy metals from wastewater. Atomic absorption spectroscopy(AAS) was employed to measure the concentrations of these metal ions in two wastewater samples(WW1 and WW2). Surface-morphology and elemental-composition of the cabbagepeels and bananatrunks were analyzed using scanning-electronmicroscopy(SEM) and energy-dispersiveX-ray-spectroscopy(EDX). Study examined the effects of pH, contact time, and adsorbent dosage on adsorption process. The adsorption-isotherms for the removal of heavy metals were determined. Zinc, copper, iron, and cadmium were detected in the wastewater samples. Effect of pH on zinc removal showed the highest removal at 39.42% at pH2 for WW1 and 16.2% at pH2 for WW2, for cadmium, the highest removal was 24.7% at pH2 for WW1 and 46.6% at pH2 for WW2. Iron removal was 15.6% at pH6 for WW1 and 41.5% at pH6 for WW2. Copper removal reached 39.3% at pH4 for WW1 and 43.6% at pH6 for WW2. The effect of adsorbent dosage for iron, the maximum removal was 28.42% at 1g of adsorbent for WW1 and 24.98% at 4g for WW2. For cadmium, the highest removal was 30.5% at 1g for WW1 and 20.43% at 1g for WW2. For zinc, the maximum removal was 40.08% at 4g for WW1 and 16.56% at 2g for WW2. For copper, the highest removal was 28.86% at 2g for WW1 and 38.56% at 2g for WW2. Contact time, the maximum removal of iron was 16.65% after 100minutes for WW1 and 23.01% for WW2. For cadmium, the highest removal was 14.92% after 20minutes for WW1 and 16.4% for WW2. Zinc removal reached 14.92% after 20minutes for WW1 and 3.32% for WW2. For copper, the maximum removal was 24.28% after 100minutes for WW1 and 33.42% for WW2. The adsorption equilibrium data for the metal-ions were best fitted with the Freundlich-isotherm model. Cabbagepeels and bananatrunk has considerable potential as low-cost adsorbents for the removal of heavy metals from wastewater.

Benzothiazolines are a class of heterocyclic compounds known for their diverse biological properties, as reported in the literature [1-2]. These properties have motivated extensive research to synthesize derivatives with enhanced and multiple biological activities.

Similarly, Schiff bases are well documented for their significant biological activity and diverse applications [3-5]. They remain a focus of research for the development of novel biologically active compounds.

In this study, we synthesized a Schiff base derivative of benzothiazolone, (E)-6-(((5-chloro-2-hydroxyphenyl)imino)methyl)-3-methylbenzo[d]thiazol-2(3H)-one, (1a), using a green chemistry approach. The reaction employed ultrasound-assisted synthesis in ethanol, resulting in an appreciable yield. Starting materials included 3-methyl-2-benzothiazolinone and 5-chloro-2-hydroxybenzaldehyde. The structure of SBM was confirmed using IR, ¹H NMR, and ¹³C NMR spectroscopic techniques.

Additionally, the pharmacokinetic and drug-likeness features of (1a) were evaluated using Lipinski's Rule of Five, a guideline that assesses a compound's potential as an orally active drug based on properties such as molecular weight, lipophilicity, and hydrogen bond donors/acceptors. The findings highlight the synthesized compound's potential biological relevance and suitability for further development.

[1] M. Erdogan et al., “Design, synthesis and biological evaluation of new benzoxazolone/benzothiazolone derivatives as multi-target agents against Alzheimer’s disease,” European J. of Med Chem, vol. 212, p. 113124, Feb. 2021, doi: 10.1016/j.ejmech.2020.113124.

[2] S. H. Ferreira, et al., “S14080, a peripheral analgesic acting by release of an endogenous circulating opioid‐like substance,” British J Pharmacology, vol. 114, no. 2, pp. 303–308, Jan. 1995, doi: 10.1111/j.1476-5381.1995.tb13227.x.

[3] N. Dharmaraj, et al., “Ruthenium(II) complexes containing bidentate Schi€ bases and their antifungal activity”.

[4] R. S. Joseyphus and M. S. Nair, “Antibacterial and Antifungal Studies on Some Schiff Base Complexes of Zinc(II),” Mycobiology, vol. 36, no. 2, pp. 93–98, Jun. 2008.

[5] A. Jarrahpour, et al., Molecules, vol. 12, no. 8, pp. 1720–1730, Aug. 2007, doi: 10.3390/12081720.

The chemistry of heterocycles has received a great deal of attention in recent times due to their importance, and among these heterocycles is benzothiazolinone, which has received a great deal of attention due to its biological, pharmacological [1], [2], and agricultural [3] benefits.
Schiff bases, which are molecules whose structure contains imine functions (C=N), have also been the subject of constant attention and development due to their different biological properties [4], [5].
In this context, we synthesized an imine-benzothiazolinone molecule (E)-3-methyl-6-((naphthalen-1-ylimino)methyl)benzo[d]thiazol-2(3H)-one according to an environmentally friendly green chemistry approach using ultrasound in ethanol, which enabled the target compound to be recovered in high yield in a short and pure time without the need for purification techniques.
The structure of the compound was confirmed by IR, ¹H NMR and ¹³C NMR spectroscopic methods. Additionally, a study was conducted to examine the synthetic compound's pharmacological ADME properties based on lipinski's rule of five , revealing favorable drug-likeness characteristics and supporting its potential for further pharmaceutical development." .

References

[1] M. Ciba, F. Kaynak, S. Ozgen, et al., “Microwave Synthesis and Antimicrobial Evaluation of Mannich Bases of 6-Benzoyl-2(3H)-benzothiazolone,” Asian J. Chem..

[2] J.-Q. Weng, X.-H. Liu, H. Huang, C.-X. Tan, and J. Chen, “Synthesis, Structure and Antifungal Activity of New 3-[(5-Aryl-1,3,4-oxadiazol-2-yl)methyl]benzo[d]thiazol-2(3H)-ones,” Molecules, vol. 17, no. 1, pp. 989–1001, Jan. 2012, doi: 10.3390/molecules17010989.

[3] “Elderfield, R.C. Heterocyclic Compounds; John Wiley & Sons: New York, NY, USA, 1957; p. 484.”.

[4] S. S. Tajudeen and G. Kannappan, “Schiff Base–Copper(II) Complexes: Synthesis, Spectral Studies and Anti-tubercular and Antimicrobial Activity,” Indian Journal of Advances in Chemical Science, 2016.

[5] A. Jarrahpour, D. Khalili, E. De Clercq, C. Salmi, and J. M. Brunel, “Synthesis, Antibacterial, Antifungal and Antiviral Activity Evaluation of Some New bis-Schiff Bases of Isatin and Their Derivatives,” Molecules, vol. 12, no. 8, pp. 1720–1730, Aug. 2007, doi: 10.3390/12081720.

Triazole containing compounds are very important due to their vast utility in medicinal, pharmaceutical, industrial, catalytic and agro-medicinal field. The Schiff base ligands incorporating triazole moiety and their derived metal complexes are of great interest due to their bonding beauties, structural diversities and easiness to prepare. The wide range of biological activities has created huge research interest in these compounds.

Triazole derived Schiff base ligand, 5-methyl-4-[(E)-(phenylmethylidene) amino]-4H-1,2,4-triazole-3-thiol (HL) and its metal complex with Cd(II) and Hg(II) was prepared in solid state. Green solvent free method was also applied for synthesis of ligand. The prepared compounds were characterized by elemental analysis, Infrared spectroscopy, NMR spectroscopy, magnetic moment & electrical conductivity data and Scanning electron microscopy analysis.

The ligand (HL) is potentially N,S donor molecule. The elemental analysis suggest that complexes have composition [M(L)₂] where M= Metal and L=Deprotonated ligand. The electrical conductivity values suggests that compounds are non-electrolytes. The metal complexes are diamagnetic in nature. The proton NMR spectra of ligand and its Hg(II) complex in DMSO-D6 indicated that ligand exists in thiol form and deprotonation of ligand is observed in Hg(II) complex. The infrared spectra of complexes clearly indicate that ligand is bidentate, donating to metal through aldimine N-atom and deprotonated thiol group. The SEM analysis was utilized to study the morphology and topography of the prepared compounds.

The schiff base ligand (HL) and its metal complexes with Cd(II) and Hg(II) ions were prepared and characterized using elemental and various spectral techniques. SEM analysis was used to describe the morphology of compounds. The complexes are neutral with composition [M(L)₂]. The NMR and IR spectra confirmed the formation of ligand and revealed that ligand is bidentate chelating molecule donating from aldimine N-atom and thiol group S-atom.