Large-scale Manufacturing Research Articles

Wafer-scale fabrication of single-crystalline calcium fluoride thin-film on insulator by ion-cutting

Developing bulk materials into thin-films not only enables multiple physical fields to interact strongly within a smaller volume but also enhances the stability, scalability, and integrability of the system. This transformation has been witnessed to lead to significant improvements in the performance of devices utilizing diverse materials across various fields. Calcium Fluoride (CaF2), with remarkable optical properties such as ultralow optical loss and strong nonlinear features, is a preferable material for building ultra-high-Q resonators and stimulating light-matter interaction with low threshold. However, the integration of CaF2 material has remained elusive due to its low hardness and high thermal expansion, which plagues the large-scale fabrication of CaF2 thin film. Here, an optimized ion-cutting technique is proposed for engineering CaF2 thin films theoretically and experimentally. Taking the thermal expansion into consideration, we employ the Lithium niobate (LN) as substrate, and utilize accessible ion implantation, wafer bonding and precisely designed annealing process to attain the CaF2-LN and the CaF2-on-insulator (CaFOI) with high film thickness uniformity and maintained crystalline quality. The perspectives of our work are also illustrated by numerical simulation for further verifying the potential of integrated photonic applications, which could be extended to monolithic optical network by means of large-scale manufacturing method.

3D Bulk Metamaterials with Engineered Optical Dispersion at Terahertz Frequencies Utilizing Amorphous Multilayered Split-Ring Resonators.

A 3D bulk metamaterial (MM) containing amorphous multilayered split-ring resonators is proposed, fabricated, and evaluated. Experimentally, the effective refractive index is engineered via the 3D bulk MM, with a contrast of 0.118 across the frequency span from 0.315 to 0.366 THz and the index changing at a slope of 2.314 per THz within this frequency range. Additionally, the 3D bulk MM exhibits optical isotropy with respect to polarization. Moreover, the peak transmission and optical dispersion are tailored by adjusting the density of the split-ring resonators. Compared to reported conventional approaches for constructing bulk MMs, this approach offers advantages in terms of the potential for large-scale manufacturing, the ability to adopt any shape, optical isotropy, and rapid optical dispersion. These features hold promise for dispersive optical devices operating at THz frequencies, such as high-dispersive prisms for high-resolution spectroscopy.

Biomimetic Mechanical Robust Cement-Resin Composites with Machine Learning-Assisted Gradient Hierarchical Structures.

Biological materials relying on hierarchically ordered architectures inspire the emergence of advanced composites with mutually exclusive mechanical properties, but the efficient topology optimization and large-scale manufacturing remain challenging. Herein, this work proposes a scalable bottom-up approach to fabricate a novel nacre-like cement-resin composite with gradient brick-and-mortar (BM) structure, and demonstrates a machine learning-assisted method to optimize the gradient structure. The fabricated gradient composite exhibits an extraordinary combination of high flexural strength, toughness, and impact resistance. Particularly, the toughness and impact resistance of such composite attractively surpass the cement counterparts by factors of approximately 700 and 600 times, and even outperform natural rocks, fiber-reinforced cement-based materials and even some alloys. The strengthening and toughening mechanisms are clarified as the regional-matrix densifying and crack-tip shielding effects caused by the gradient BM structure. The developed gradient composite not only endows a promising structural material for protective applications in harsh scenarios, but also paves a new way for biomimetic metamaterials designing.

Overcoming the inconsistent cell culture performance caused by single-use bioreactors during scaling-up the manufacturing process for a therapeutic bispecific antibody

Single use technology has been widely used in modern biopharmaceutical process development and manufacturing. However, there are concerns about the adverse effects of disposable materials on bioprocess, product quality and patient safety. Recently, we observed slow cell growth, increased lactate accumulation, and decreased production titer during scaling up a bispecific antibody (BsAb) upstream process from 3 L to 500 L bioreactor. To investigate the phenomenon, we conducted medium incubation and leachable spike-in experiments. We found that cell culture medium incubated in CX5–14 bag caused poor cell culture performance, which was correlated with the concentration of bis(2,4-di-tert-butylphenyl)-phosphate (bDtBPP), a breakdown product of the antioxidant Irgafos®168 in polyethylene film. In addition, when the media were spiked with 0.15 μg/ml or a greater concentration of bDtBPP, slow cell growth and reduced BsAb expression level were observed. In contrast, Aegis5–14 film produced bDtBPP at a level of below detection during medium incubation. Thus, the bispecific-expressing CHO cell line restores normal cell culture performance and production titer when Aegis5–14 single-use bioreactor was employed in large-scale manufacturing. Our results reveal the importance of evaluating leachable profiles from disposable materials during process development of bispecifics and other novel therapeutic modalities.

Role of crystalline orientations and additive layers on bulk tensile response of wire-arc directed energy deposited (WDED) single phase titanium

A significant challenge in improving metal-based wire-arc directed energy deposition (WDED) for additive manufacturing is the lack of knowledge about microstructure evolution and its correlation with layer-wise plastic response and bulk tensile behavior. For the first time, this paper establishes the role of crystalline orientation, dislocation densities, and layer-by-layer strength on the anisotropy of bulk uniaxial tensile deformation in commercially pure titanium (cp-Ti) processed by WDED. An integrated approach that combines microscopy, spectroscopy, millimeter-scale indentation and centimeter-scale uniaxial tensile techniques is adopted. The variation in thermal cycles during WDED results in a higher grain orientation spread greater than 5° in the longitudinal direction (LD) parallel to arc motion compared to about 4° along the normal direction (ND) of additive buildup. Similarly, the statistically stored dislocation density in LD, 1.8 x 1016 m−2, is double that in ND, 0.9 x 1016 m−2. These factors result in a greater strain localization in the LD than in ND. The higher strain localization results in plastic anisotropy manifested as material buildup and ductility, which are 40 μm and 33 % higher in ND than in LD. On the other hand, the monolithic macrostructure and absence of weak points at layer interfaces of the cp-Ti component led to comparable yield and ultimate tensile strengths across the individual layers and the bulk component at 311–328 MPa and 369–385 MPa, respectively. These properties are about 90 % of those in conventionally cast commercially cast titanium. Thus, the comprehensive understanding of titanium's nuanced isotropic strength and anisotropic ductility constitutes a major step in advancing WDED as a large-scale additive manufacturing technology and establishing a standardized database of mechanical properties.

Interfacial engineering and vacancy design of quasi-2D NiCoAl-LDH/Kaolin hybrid for activating peroxymonosulfate to boost degradation of antibiotics

Oxygen vacancies are prevalent in metal compounds and play a significant role in the activation of peroxomonosulfate (PMS) to mitigate water pollution. However, how to easily construct these oxygen vacancies and elucidate the mechanism of PMS activation by oxygen vacancies are still pending research and solution. This study presents the synthesis of a NiCoAl-LDH/Kaolin (NiCoAl-LDH/Kao) hybrid catalyst with quasi-2D layer structures morphology and abundant oxygen vacancies (OVs) for activating peroxymonosulfate (PMS). We proposed an intriguing phase transformation from NiCo-carbonate hydroxide (CH) to NiCoAl-layered double hydroxide (LDH), and elucidated the morphological evolution mechanism from nanorod to nanosheet structures through alkaline etching. The NiCoAl-LDH/Kao-PMS system exhibited excellent rapid kinetics and removal efficiency of norfloxacin (NOR), degrading 92.0 % of NOR within 10 min and achieving a final degradation rate of 97.2 %, along with remarkable reusability performance of the NiCoAl-LDH/Kao catalyst. Furthermore, reactive oxygen species including sulfate radical (SO4−), hydroxyl radical (OH), superoxide anion (O2−) and singlet oxygen (1O2) were found to be involved in the degradation process of NOR, and the degree of activity of the active groups from strong to weak is 1O2, SO4−, O2− and OH. The activation mechanism and conceivable degradation pathways of NOR were experimentally studied and proposed, and the toxicity of degradation intermediates was evaluated. The facile preparation method for NiCoAl-LDH/Kao nanocomposite holds potential for large-scale manufacturing in organic pollutant remediation, while also providing new insights on the indispensable role of OVs in heterogeneous catalysis.

Spacer Side-wall Processed 0.15 μm GaN HEMT for Ka-band Application

In this paper, we have effectively demonstrated 150 nm-gate-length AlGaN/GaN high electron mobility transistors (HEMTs) on 4-inch SiC substrate. The 150 nm gate-length was accomplished by utilizing traditional I-line stepper photolithography, together with a nitride spacer side-wall. This method offers superior processing efficiency compared to E-beam lithography with high wafer uniformity. The devices processed with this spacer side-wall aided method demonstrated comparable electrical performances as that of E-beam processed one with fT of 45 GHz, fMAX of 80 GHz, Pout of 31 dBm and PAE of 45% at 29 GHz, which can be imported to large scale manufacturing.

High-precision and Large-Scale Vat Photopolymerization Printing based on "Spatial-Pixel Integration Compensation" method

Vat photopolymerization (VPP) is widely known for its exceptional printing accuracy, but effectively controlling stitching errors to achieve high-precision, large-scale printing remains a significant challenge. This study introduces a novel compensation method, termed "Spatial-Pixel Integration Compensation" (SPIC), to address this key obstacle. SPIC combines Spatial Motion Compensation to initially control stitching errors between adjacent sub-images to be within 100 µm and Pixel Compensation for precise adjustments, further reducing stitching errors. Integrating SPIC with our high-precision printing system resulted in a remarkable reduction of stitching errors by a factor exceeding 40. Crucially, this method minimizes the stitching error between any two sub-images to be less than one pixel point, specifically below 4 µm. Notably, SPIC is the first method specifically focused on effectively controlling and reducing stitching errors to achieve large-scale printing while maintaining high precision. To validate the practical applicability of the SPIC method, we used SPIC to print both Zig-Zag and herringbone structures (HBS) and achieved high-precision large-scale manufacturing with dimensions of 44 mm × 33 mm. In the HBS structure, the minimum feature size was 14.2 µm, and the printing error was less than 1 µm. These printed structures were used as molds to fabricate proof-of-concept polydimethylsiloxane (PDMS) microfluidic chips, demonstrating the successful mixing of rhodamine B and ethanol within the microfluidic channels. Furthermore, SPIC was extended to the printing of complex three-dimensional (3D) Triple-Periodic Minimal Surface (TPMS) structures, successfully producing TPMS-Gyroid and TPMS-Diamond structures with a minimum feature size of 20 µm and a printing error below 1.5 µm. These results demonstrate that the SPIC algorithm effectively enables high-precision, large-scale printing. This work significantly advances the application of VPP technology in fields requiring complex, high-precision, and large-scale 3D structures and provides valuable insights for future research in high-precision and large-scale printing.

Green Intellectual Capital: Boosting Sustainability via Innovation, Value Creation & Resource Efficiency

In today's environmentally conscious marketplace, achieving businesssustainability is paramount for manufacturing firms. This pressure is particularlyacute in developing nations like Pakistan, where balancing economic growth withenvironmental responsibility presents unique challenges. Hence this study delvesinto the critical relationship between green intellectual capital (GIC) and businesssustainability in Pakistan's manufacturing sector. The researcher also examined themediating effects of green innovation, value creation, and resource efficiency onthis association. Employing a survey instrument, data is collected from large scalemanufacturing firms located in three different industrial cities of Pakistan throughconvenient sampling. Smart PLS SEM was used to explore the hypothesizedrelationships and the mechanisms through which GIC impacts businesssustainability via mediating variables. The results confirmed all hypotheses asstatistically significant. The first hypothesis showed a positive and significantrelationship between GIC and business sustainability (β = 0.101, p < 0.05). Thesecond hypothesis demonstrated that value creation effectively mediates therelationship between GIC and business sustainability (β = 0.191, p < 0.05). Thethird and fourth hypothesis found that green innovation and Resource efficiencyboth significantly mediates between green intellectual capital and businesssustainability with (B=0.183, p<0.05) and (B=0.120, p<0.05) respectively. Henceall the hypotheses were supported. These findings hold significant implications forPakistani manufacturing firms, offering valuable insights into strengthening theirenvironmental practices and achieving long-term sustainability. However, theapplicability of these findings to other sectors or countries may require furtherinvestigation. Further research employing more robust sampling techniques canenhance the generalizability of the findings

Electric underwater tools for sun coral management

Sun coral, identified as Tubastraea coccinea and Tubastraea tagusensis, are invasive marine species originally from the Pacific Ocean that have become a significant threat to native biodiversity and ecosystems in Brazil. The rapid growth and unique reproduction strategies of Tubastraea species have facilitated their success as invasive species. In the past two decades, Brazil has experienced a notable loss of biodiversity, partially attributed to invasive species, as reported by the Brazilian Platform on Biodiversity and Ecosystem Services. Current management efforts primarily involve manual removal, often employing sledgehammers and chisels, carried out by environmental government agencies, in partnership with NGOs and volunteers. However, the need for more efficient management strategies emphasizes the important role of engineering and technology in improving environmental management. To address this issue, our work focuses on the development and prototyping of two underwater tools: an impact hammer and a rotating brush. These tools are designed with ergonomic features, operating time, and size considerations suitable for use by SCUBA divers. Our prototypes have successfully met the required specifications and offer potential for large-scale manufacturing, promising more effective measures for controlling invasive sun coral in Brazil.

Buried interface molecular hybrid for inverted perovskite solar cells.

Perovskite solar cells with an inverted architecture provide a key pathway for commercializing this emerging photovoltaic technology because of the better power conversion efficiency and operational stability compared with the normal device structure. Specifically, power conversion efficiencies of the inverted perovskite solar cells have exceeded 25% owing to the development of improved self-assembled molecules1-5 and passivation strategies6-8. However, poor wettability and agglomeration of self-assembled molecules9-12 cause interfacial losses, impeding further improvement in thepower conversion efficiency and stability. Here we report a molecular hybrid at the buried interface in inverted perovskite solar cells that co-assembled the popular self-assembled molecule [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz) with the multiple aromatic carboxylic acid 4,4',4″-nitrilotribenzoic acid (NA) to improve the heterojunction interface. The molecular hybrid of Me-4PACz with NA could substantially improve the interfacial characteristics. The resulting inverted perovskite solar cells demonstrated a record certified steady-state efficiency of 26.54%. Crucially, this strategy aligns seamlessly with large-scale manufacturing, achieving one of the highest certified power conversion efficiencies for inverted mini-modules at 22.74% (aperture area 11.1 cm2). Our device also maintained 96.1% of its initial power conversion efficiency after more than 2,400 h of 1-sun operation in ambient air.

Continuous flow production of bioactive ceria quantum dots: New paradigms to the effect of process parameters on surface oxygen vacancy tuning

Precisely monitored nucleation-growth kinetics for governing the size, surface chemistry, and sought-after attributes of quantum dots (QDs) for large-scale manufacturing remains a formidable challenge. This study evinces the importance of ultrafast mixing and high heating rates for rapid nucleation, particularly in synthesizing monodispersed QDs with enriched surface defects. Recently, cerium oxide (CeO2) nanostructures have gained prominence in antioxidant therapy owing to the co-existence of Ce3+ and Ce4+. However, current batch processes lack scalability, reproducibility, and control over the reaction kinetics, key for fine-tuning the surface defect-driven properties of CeO2 nanostructures. Addressing this knowledge gap, we demonstrate a unique, sustainable, continuous flow platform that allows simultaneous engineering of surface oxygen vacancies (VO●) and regulates the size of L arginine functionalized CeO2 QDs (VO●-rich l-arg-CeO2 QDs). Introduction of the helical coil reactor regulated by dean vortices yields monodispersed QDs with enhanced Ce3+/Ce4+ratio and VO● at the surface. Through various experimental methodologies, we showed how adjusting temperature, flowrate, and pH enables achieving the desirable size (3 nm), thereby bestowing an optimal surface Ce3+ and VO● fractions, pivotal for size-dictated photo-response, physiochemical properties, and biofunctionality of the QDs. The abundant surface VO● (72 %) entails narrowing of the band gap (∼ 2.5 eV), resulting in unprecedented photothermal response (ΔT = 19.7 ± 0.6 °C) and photoluminescence, features not typically found in defect-free conventional CeO2 nanostructures. With a strategic combination of process parameters, the defect-rich material system displayed excellent biocompatibility (95.6 %), and antioxidant efficacy on human keratinocyte (HaCaT) cells, and long-term stability (ζ = -29±1.5 mV) in suspensions, even after 120 days. This economical, high throughput continuous flow platform for fabricating biofunctionalized VO●-rich l-arg-CeO2 QDs outperforms conventional batch processes, opening numerous possibilities for lab-to-clinic translation in the fight against oxidative stress-related disorders.

A Novel Process for Improving the Drug Loading of Highly Water-Soluble High-Dose Drug in FDM 3D Printed Tablets

ABSTRACTBackground: 3D printing technologies, also known as additive manufacturing technologies, are gaining importance in pharmaceutical research and manufacturing. These technologies are widely used in automobile, plastic, and material fabrication industries. In the recent past, pharmaceutical industries are actively working to increase the applicability of these technologies in commercial manufacturing. On the other hand, clinics and hospitals are ready to adopt these technologies due to their versatility such as flexibility, individual customization, and low-cost investment. FDM 3D printing technology is one of the widely used technologies for the manufacturing of finished products. However, this technology has limitations such as drug loading, scale-up issues, and regulatory requirements. The present study focused on developing a suitable solvent system along with a drug-loading method to increase the industrial applicability of this technology. Methods: Metformin, a high-dose, highly soluble drug, was selected as a model. Solvents such as water, ethanol, and methanol and their combinations were explored. Saturation solubility and drug loading in both PVA filaments and printed tablets were tested for drug loading. The solvent ratio of ethanol/methanol/water (8:1:1) was selected. The different infills of 10, 25, 50, 75, and 100% were printed using PVA filaments and were subjected to drug loading using soaking and solvent curing methods. Results: The soaking method has resulted in poor drug loading as well as layer separation and swelling of the polymer. The solvent curing method has a maximum drug loading of 91.9% w/w without physical deformities of the tablets. Moreover, the solvent curing method is a scalable process with less process time, and hence this method could be useful for both large-scale commercial manufacturing as well as customized formulations for personalized therapies. Conclusion: This method could be used for manufacturing thermoliable drug products and moderate-dose drug substances. Based on the research outcomes, we propose a novel, scalable, and rapid solvent-curing method for drug loading in the FDM 3D printing technique.

Topically Applied Therapies for the Treatment of Skin Disease: Past, Present, and Future.

The purpose of this review is to summarize essential biological, pharmaceutical, and clinical aspects in the field of topically applied medicines that may help scientists when trying to develop new topical medicines. After a brief history of topical drug delivery, a review of the structure and function of the skin and routes of drug absorption and their limitations is provided. The most prevalent diseases and current topical treatment approaches are then detailed, the organization of which reflects the key disease categories of autoimmune and inflammatory diseases, microbial infections, skin cancers, and genetic skin diseases. The complexity of topical product development through to large-scale manufacturing along with recommended risk mitigation approaches are then highlighted. As such topical treatments are applied externally, patient preferences along with the challenges they invoke are then described, and finally the future of this field of drug delivery is discussed, with an emphasis on areas that are more likely to yield significant improvements over the topical medicines in current use or would expand the range of medicines and diseases treatable by this route of administration. SIGNIFICANCE STATEMENT: This review of the key aspects of the skin and its associated diseases and current treatments along with the intricacies of topical formulation development should be helpful in making judicious decisions about the development of new or improved topical medicines. These aspects include the choices of the active ingredients, formulations, the target patient population's preferences, limitations, and the future with regard to new skin diseases and topical medicine approaches.

Solution-processable organic–inorganic materials with colorful afterglow at room temperature

The development of large-scale manufacture for low-cost afterglow materials is critical for their applications and industrializations. Herein, we presented the organic–inorganic afterglow materials with multiple colors based on boric acid (BA) and aromatic dicarboxylic acids or their diesters. These hybrid materials were facilely prepared by a solution-processable method via evaporating the solvent of the BA and organics solution at room temperature. The crystalized BA provided a rigid surrounding for the organics via hydrogen bonds, which effectively inhibited the non-radiative decay of triplet excitons and gave efficient and persistent room temperature afterglow with the phosphorescent quantum yield up to 57.66%. The phosphorescence properties were almost unchanged when deuterated BA was used instead of BA, indicating the deuteration of the hydrogen bond would not suppress the non-radiative decay from the excited state. Furthermore, a phosphorescence resonance energy transfer process was achieved by introducing 4-[4-(Dimethylamino)styryl]-1-methylpyridinium iodide (DASPI) as the energy acceptor. These BA based system could be used as quick-writable phosphorescent inks for multifunctional applications, such as anti-counterfeiting, information storage, encryption, and even for phosphor layer of light emitting diode. These results not only strengthen the understanding of the luminescence mechanism of BA hybrid materials, but also provide a new access to organic–inorganic afterglow materials.

Large-scale production of a “skin-like” self-pumping fabric for personal sweat management

Fabrics designed for personal sweat management, capable of efficiently transporting sweat away from the skin, are highly sought after for enhancing thermal comfort and conserving energy. However, the fabrication processes for these functional garments require intricate physical and chemical modifications, resulting in poor durability and limited suitability for mass production. In this study, a “skin-like” self-pumping fabric, consisting of hydrophobic polyester coils and hydrophilic microfiber polyester coils arranged on a bi-layer knitting fabric, is presented. This configuration allows for unidirectional wicking of sweat away from the skin. The accumulative one-way transport index increased to 717.18% when spandex filaments were introduced into the polyester fabric, which was greater than that of the pristine polyester fabric (393.71%). This exceptional property is achieved by creating differential capillary effects across a predominant combination of microfiber polyester and ordinary hydrophobic polyester. In addition to functional clothing, this “skin-like” self-pumping fabric has great potential for various applications, including industrial textiles, medical wound dressings, geotechnical engineering, and device diaphragms. Overall, this work presents an effective design to achieve large-scale manufacturing of personal sweat management fabrics, which is expected to guide material design for future innovations in functional textiles.

Study of Ceramic Hollow Buoyant Balls Prepared Based on Slip Mold Casting and Brazing Process

In the domain of deep-sea buoyancy material applications, hollow ceramic spheres, known for their high strength and low mass-to-drainage ratio, contribute to increased buoyancy and payload capacity enhancement for deep submersibles, constituting buoyancy materials of exceptional overall performance. This study entails the brazing of two ceramic hemispherical shells, obtained through slurry molding, to form a ceramic float. This process, which integrates slurry molding and ceramic brazing, facilitates buoyancy provision. Further refinement involves welding a ceramic connector onto the ceramic shell, incorporating a top opening to create a ceramic float equipped with an observation window seat. The ceramic float maintains uniform wall thickness, while the observation window facilitates external environmental observation in deep-sea research. Two pressure-resistant spherical shells, produced using this process, underwent testing, revealing the wall thickness of the prepared alumina ceramic hollow spheres to be 1.00 mm, with a mass-to-drainage ratio of 0.47 g/cm3 and a buoyancy coefficient of 53%. The resultant ceramic hollow floating ball can withstand hydrostatic pressure of 120 MPa, while the pressure-resistant ball shell with an observation window seat can endure hydrostatic pressure of 100 MPa, ensuring safe operation at depths of 5000–6000 m. This process provides a production method for subsequent large-scale ceramic float manufacturing for the transportation of objects or personnel.

Pathways to Upscaling Highly Efficient Organic Solar Cells Using Green Solvents: A Study on Device Photophysics in the Transition from Lab-to-Fab.

As the rise of nonfullerene acceptors (NFA) has allowed lab-scale organic solar cells (OSC) to reach 20% efficiency, translating these devices into roll-to-roll compatible fabrication still poses many challenges for researchers. Among these are the use of green solvent solubility for large-scale manufacture, roll-to-roll compatible fabrication, and, not least, information on charge carrier dynamics in each upscaling step, to further understand the gap in performance. In this work, the reproducibility of champion devices using slot-die coating with 14% power conversion efficiency (PCE) is demonstrated, under the condition that the optimal thickness is maintained. It is further shown that for the donor:acceptor (D:A) blend PM6:Y12, the processing solvent has a more significant impact on charge carrier dynamics compared to the deposition technique. It is found that the devices processed with o-xylene feature a 40% decrease in the bimolecular recombination coefficient compared to those processed with CB, as well as a 70% increase in effective mobility. Finally, it is highlighted that blade-coating yields devices with similar carrier dynamics to slot-die coating, making it the optimal choice for lab-scale optimization with no significant loss in translation toward up-scale.

An Agile Adaptive Biased-Randomized Discrete-Event Heuristic for the Resource-Constrained Project Scheduling Problem

In industries such as aircraft or train manufacturing, large-scale manufacturing companies often manage several complex projects. Each of these projects includes multiple tasks that share a set of limited resources. Typically, these tasks are also subject to time dependencies among them. One frequent goal in these scenarios is to minimize the makespan, or total time required to complete all the tasks within the entire project. Decisions revolve around scheduling these tasks, determining the sequence in which they are processed, and allocating shared resources to optimize efficiency while respecting the time dependencies among tasks. This problem is known in the scientific literature as the Resource-Constrained Project Scheduling Problem (RCPSP). Being an NP-hard problem with time dependencies and resource constraints, several optimization algorithms have already been proposed to tackle the RCPSP. In this paper, a novel discrete-event heuristic is introduced and later extended into an agile biased-randomized algorithm complemented with an adaptive capability to tune the parameters of the algorithm. The results underscore the effectiveness of the algorithm in finding competitive solutions for this problem within short computing times.

Reduced Graphene Synthesis via Eco-Friendly Electrochemical Exfoliation Method

A novel approach to mass producing graphene without inadvertent damage was needed to meet the increasing demand for the material. Graphite electrochemical exfoliation (EE) is an intriguing method for the large-scale, quick, and easy manufacture of graphene. Using leftover whey as an electrolyte, the EE of commercial graphite was examined in this work. It was shown that a straightforward and affordable exfoliation technique may produce graphene that, in the absence of functionalization or surfactant, forms a stable dispersion in the waste solvent. Because wastewater is acidic, it has been shown that storing it at +4 degrees aids EE. X-ray diffraction (XRD) was used to satisfactorily validate the manufactured graphene's existence. The results point to a low-cost method of producing graphene and graphene oxide.