Specific Mold Research Articles

Compaction Characteristics of Fly Ash and Pond Ash: A Comparative Analysis

This study investigates the compaction characteristics of Fly Ash and Pond Ash, which are by-products of coal combustion in thermal power plants. Thermal power plants generate three types of ash: (a) Fly Ash, (b) Pond Ash, and (c) Bottom Ash. Fly Ash consists of fine particles carried out of the boiler with flue gases, while Bottom Ash is the residue that settles at the bottom of the boiler. In most coal plants, Fly Ash is captured using electrostatic precipitators and other filtration equipment before the flue gases are released through the chimney. Pond Ash, on the other hand, is a by-product of thermoelectric power plants, often regarded as waste material, posing significant environmental disposal challenges. The compaction characteristics of Fly Ash and Pond Ash are influenced by various factors, including specific gravity, moisture content, compaction energy, layer thickness, and mold area. In this study, Fly Ash collected from NTPC Sipat , Chhattisgarh exhibited an Optimum Moisture Content (OMC) ranging from 18% to 27% and a Maximum Dry Density (MDD) ranging from 0.90 to 1.59 gm/cc under standard Proctor compaction energy. Similarly, Pond Ash demonstrated an OMC ranging from 33% to 46% and an MDD ranging from 0.856 to 1.248 gm/cc under the same conditions. The findings indicate that variations in these factors significantly affect the dry density of both Fly Ash and Pond Ash. The study also aims to determine the geotechnical properties of these materials, providing insights into their potential applications in engineering and environmental management

Flexural Properties, Wear Resistance, and Microstructural Analysis of Highly Filled Flowable Resin Composites.

This study aimed to evaluate the flexural properties and two-body wear resistance of nine highly filled flowable resin composites relative to those of viscous and conventional low-filled flowable composites. In addition, scanning electron microscopy (SEM) analysis of the microstructures was performed. For each resin composite group (n=12), 12 specimen bars (25 mm × 2 mm × 2 mm) were fabricated using a silicon mold for performing flexural strength (FS), flexural modulus (E), flexural toughness (FT), Weibull modulus (m) tests, and SEM microstructural analysis. For each group, ten bars were tested using a three-point flexural test on a universal testing machine, while the other two were embedded in acrylic resin before being observed by SEM for structural analysis. During the two-body wear test with a chewing simulator, 8 specimens (12 groups, n=8) of each resin composite group were manufactured in a specific mold and subjected to 120,000 cycles of wear against a steatite ball, and the depth loss was measured. Three one-way ANOVA tests followed by Tukey's post hoc tests were conducted to compare the flexural and wear properties among the different groups. The majority of highly filled composites tested in this study exhibited similar flexural strengths (between 105.68 MPa and 135.49 MPa) and superior wear resistance to those of viscous composites. The flexural moduli (between 5.12 GPa and 9.62 GPa) of these composites were in between those of the viscous and low-filled composites tested in this study. The highly filled flowable composites tested in this study exhibited different in vitro properties but were often superior to those of viscous resin composite suggesting their possible use for posterior restorations.

Hub production scheduling problem with mold availability constraints

This research delves into a scheduling challenge inherent in the wheel hub casting process, a critical stage in automotive wheel manufacturing. The process involves shaping molten metal into specific wheel hub designs using dedicated molds. Diverse customer demands necessitate a unique mold for each wheel hub design, posing a scheduling challenge due to the limited availability of these expensive and long-lasting molds. There are 2 machines available for casting. Each wheel hub design requires a specific mold. These molds are expensive, long-lasting, and need periodic maintenance. The objective function is to minimize the total time (makespan) to complete all casting jobs. Only one job requiring a specific mold can be processed at a time (due to mold limitations). Molds are unavailable during maintenance periods. The challenge lies in scheduling jobs considering both machine availability and mold constraints to minimize the overall production time. We formulate a mathematical model using mixed integer programming to precisely represent the problem and its constraints. Inspired by the Longest Processing Time (LPT) rule, we propose a heuristic named LRTPT to efficiently schedule jobs on the two machines. For large-scale problems, we employ a novel SIAIS algorithm to find near-optimal solutions effectively. We also present a dedicated branch and bound algorithm specifically tailored to solve smaller-sized instances of the problem. This algorithm leverages two lower bounds and several dominance properties to expedite the search for the optimal solution. To evaluate the effectiveness of our proposed approaches, we conduct a series of comprehensive experiments. The results demonstrate that the branch and bound algorithm significantly outperforms the widely used optimization solver CPLEX for smaller problems. Furthermore, the SIAIS algorithm proves to be more efficient than existing scheduling heuristics.

Inhibitory effects of essential oils on the growth of grain storage molds and the formation of aflatoxin in stored organic corn grains

AbstractBackgroundMold contamination in post‐harvest grain storage degrades grain quality and produces mycotoxins, causing economic losses and health issues. This study evaluated the inhibitory effects of six essential oils (cinnamon, clove, eugenol, orange terpenes, oregano, and thyme oil) on total and specific mold genera growth using potato dextrose agar (PDA) and selective media plates, respectively, at different concentrations of EOs (0–0.8 mg/mL). The antifungal index (AI) of each treatment were measured after 7 days incubation at 22°C. The fungicidal activity of EOs in stored organic corn grains was tested using a simulated fumigation method, and the aflatoxin contents in the corn grains were determined biweekly for 6 weeks.ResultsResults indicate that the tested EOs, except orange terpenes, significantly inhibited mold growth. Overall, eugenol demonstrated the highest effectiveness against total mold growth with cinnamon oil following closely behind. The cinnamon oil also consistently showed highest AI and lowest IC50 (0.065 mg/mL) against the growth of Aspergillus and Penicillium followed by clove oil with IC50 being 0.12 mg/mL. The Fusarium spp. was more sensitive to EOs, particularly cinnamon oil (IC50 = 0.006 mg/mL), and eugenol and oregano oil (IC50 = 0.01 mg/mL). In the simulated fumigation tests, cinnamon, oregano, and thyme oils at 0.05 mL/25 g corn significantly inhibited the mold growth and aflatoxin production at water activity 0.85, and temperature 25 and 35°C over a period of 42 days storage.ConclusionThe EOs tested in this study except orange terpenes can potentially serve as alternatives to toxic synthetic fungicides/fumigants for organic corn grain protection during storage.

Research and Application of the Simulation Method for Product Development Process Based on System Dynamics

Product development is a complex process involving intricate components, dynamics and constantly evolving internal and external environments, as well as numerous influencing factors. In order to accurately simulate and predict the effectiveness of the development process, this paper proposes a system dynamics simulation method based on information maturity. Different types of development processes are simulated, and the discussion includes the impact of activity information correlation, information evolution coefficient, start time, and other parameters on the dynamic behavior of the process. This study examines a specific mold development process as a case study to validate the method’s feasibility, accurately predicting the duration and cost of the process. It also investigates dynamic fluctuations resulting from uncertain events such as changes in customer demand and resource shortages. The method provides support for process optimization and resource scheduling.

Impacts of interfacial bonding between concrete substrate and cast/sprayed HPFRCC on flexural behaviour

The performance of repair materials is greatly enhanced by the integrity of the rehabilitation system, which depends on the behaviour of the boundary or interface bond between the repair material and the concrete substrate. The effects of the implementation of repair materials (casting or spraying), the spraying direction and the roughness of the concrete substrate on the interfacial bond behaviour were experimentally investigated through four-point bending tests on prisms of size 300 × 76.2 × 40 mm. As a first step, 2 cm thick concrete substrates were fabricated with five different types of surface roughness. After 28 days of curing, the repair material (a high-performance (high-ductility) fibre-reinforced cementitious composite (HPFRCC)) was sprayed or poured into specific moulds. The HPFRCC was developed using local materials and had a tensile strain capacity of 3.7%. The spraying direction and surface roughness of the concrete substrate were found to impact the ultimate deflection rate significantly; upward spraying produced the lowest deflection rate and downward spraying the highest. Because beams are often repaired from the lower part and spraying is in the upwards direction, the casting method must be used because of the negative effect of gravity on the interfacial bonding between the concrete substrate and the repair material.

Elasto-Plastic Materials based on EPDM Rubber, LDPE, Plasticized Starch and OMMT

This paper describes the development of new types of dynamically cross-linked thermoplastic elastomers based on ethylene-propylene-terpolymer rubber and low-density polyethylene, reinforced with plasticized starch and montmorillonite with a chemically modified surface. An octylphenol-formaldehyde resin in the presence of stannous chloride dihydrate was used as a vulcanizing agent. The samples were obtained on a Brabender Plasti-Corder mixer, at appropriate temperatures and rotation speeds, using the dynamic vulcanization method and the melt intercalation technique. The mixtures obtained were modeled in the form of plates with standard dimensions using specific molds and a laboratory-scale electrical press. The obtained samples were analyzed from the point of view of the physical-mechanical properties, the melt flow index, as well as from the structural and morphological point of view. It was observed that the characteristics of the samples are influenced by both the composition and the methods of obtaining used. According to the obtained characteristics, the new elasto-plastic materials can be used in fields such as the footwear industry (for the production of: soles, heels, protective boots), in the rubber and plastics industry, the automobile industry, agriculture or construction (when making gaskets, technical items, hoses, etc.). They can be easily processed into different finished products by methods specific to plastics.

Exploiting light-based 3D-printing for the fabrication of mechanically enhanced, patient-specific aortic grafts

Despite polyester vascular grafts being routinely used in life-saving aortic aneurysm surgeries, they are less compliant than the healthy, native human aorta. This mismatch in mechanical behaviour has been associated with disruption of haemodynamics contributing to several long-term cardiovascular complications. Moreover, current fabrication approaches mean that opportunities to personalise grafts to the individual anatomical features are limited. Various modifications to graft design have been investigated to overcome such limitations; yet optimal graft functionality remains to be achieved. This study reports on the development and characterisation of an alternative vascular graft material. An alginate:PEGDA (AL:PE) interpenetrating polymer network (IPN) hydrogel has been produced with uniaxial tensile tests revealing similar strength and stiffness (0.39 ± 0.05 MPa and 1.61 ± 0.19 MPa, respectively) to the human aorta. Moreover, AL:PE tubular conduits of similar geometrical dimensions to segments of the aorta were produced, either via conventional moulding methods or stereolithography (SLA) 3D-printing. While both fabrication methods successfully demonstrated AL:PE hydrogel production, SLA 3D-printing was more easily adaptable to the fabrication of complex structures without the need of specific moulds or further post-processing. Additionally, most 3D-printed AL:PE hydrogel tubular conduits sustained, without failure, compression up to 50% their outer diameter and returned to their original shape upon load removal, thereby exhibiting promising behaviour that could withstand pulsatile pressure in vivo. Overall, these results suggest that this AL:PE IPN hydrogel formulation in combination with 3D-printing, has great potential for accelerating progress towards personalised and mechanically-matched aortic grafts.

Study on the Cleaning of Mold Spots on Embroidery and the Extraction and Identification of Mold

This article collected mold samples from Suzhou Zhenhu embroidery samples contaminated with mold, cultured, isolated, and identified them, and obtained six types of mold samples. Aspergillus, 2-1 (MH091025.1), 7-2 (KP269023.1), Penicillium, 3-1 (MN856268.1), 3-2 (MK368538.1), Eupenidiella, 1-2 (EU019278.1), and Talaromyces,6-2 (KU8666646.1). The use of ultrasound and other technologies to bleach specific mold stains has basically eliminated the traces of mold stains.

An Evaluation of Traditional and Innovatory Approaches in Arnold Schoenberg’s Verklärte Nacht and ‘Nacht’ from Pierrot Lunaire

This study analyzes Arnold Schoenberg’s particular perspective on tradition and innovation. Verklärte Nacht (1899), which he composed in his tonal period and which thus has a more traditional character, and Pierrot Lunaire (1912), from his ‘free’ atonal period, are discussed to illustrate the composer’s different approaches. This article aims to show that these approaches do not represent two separate periods but rather create a single style and can be understood as mutually related within the composer’s output. Schoenberg’s Verklärte Nacht, Op. 4 and Pierrot Lunaire, Op. 21, No. 8 will be interpreted in the context of tradition-innovation relations by means of descriptive analysis and literature review, and in the context of wider tradition and innovation relations in his other works. It is observed that the composer still adhered to 19th-century traditions at some points; however, as he himself argued, it is unrealistic to force Schoenberg into a specific mould. When examining the different compositional periods of the composer, it is possible to discern diverse features. It should be noted that the traditionalist and innovative tendencies in the composer’s works are not distinguished as easily as may be thought, and that the composer should not be evaluated in terms of degrees of complexity. Results show that Schoenberg was not a composer who adhered to any one theory or technique, but rather a versatile composer. Describing him as a traditionalist on one hand or a radical innovator on the other does him a disservice.

Integrated optimization of production scheduling and maintenance planning with dynamic job arrivals and mold constraints

Effective management of production often requires harmonizing maintenance and production activities. However, decsions on production scheduling and machine maintenance are usually made independently, leading to potential overlaps and inefficiencies. This paper joinly investigates the production scheduling and maintenance planning for a production machine subject to different types of jobs that arrive randomly. A unique emphasis is placed on the prerequisite of loading specific molds prior to job execution, an element often overlooked in previous studies. Maintenance considerations employ the reliability/availability framework. The overarching goal is the creation of an integrated schedule that minimizes the weighted sum of total costs and the machine's maximum unavailability. To address this intricate challenge, a novel hybrid differential evolution and genetic algorithm (DE-GA) is proposed, complemented by a solution refinement strategy. Performance evaluations indicate that DE-GA methodology consistently outperforms Gurobi solver and four other prevalent algorithms across different test instances.

“Generating a eco friendly reinforced composite using human hair and analyzing it for commercial use”

This paper delves into the development and characterization of natural hair fiber-reinforced polymer composites, with a focus on their physical and mechanical attributes. Composite materials encompass ceramic matrix composites (CMC), metal matrix composites (MMC), and polymer matrix composites (PMC), with PMC being favored for its cost-efficiency and ease of production, notably employing thermoplastic polymers for recyclability. Natural fibers are gaining traction, especially in the automotive industry across Asia and Europe, due to their low density and environmental friendliness. Human hair stands out as a reinforcing material owing to its impressive tensile strength, sustainability, abundance, and keratin content. The paper addresses challenges linked to natural fibers in composites, including moisture resistance and dimensional availability. The research involves creating composites using human hair fibers, epoxy resin (polypropylene), and specific molds, varying hair fiber percentages. Detailed methodology covers materials, equipment, mold prep, specimen prep, and mathematical modeling. Tensile, flexural bending, and impact strength tests reveal insights into composite mechanics. Hair fiber additions strengthen the polymer matrix, particularly at 5 to 15 weight percentages, though flexural strength diminishes compared to non-reinforced composites. Higher hair fiber percentages enhance hardness. In conclusion, this study showcases human hair fiber's potential as a reinforcement in polymer composites, emphasizing the need for further exploration of matrix-fiber adhesion to boost composite performance. These findings contribute to the growing interest in natural fiber composites for sustainable and economical applications.

An In Silico study of a One-Day One-Machine Workflow for Definitive Radiotherapy Cases on a Novel Simulation and Treatment Platform

The workflow in Radiotherapy (RT) has largely unchanged for the past three decades, despite increasing evidence suggesting that delayed access to RT, including the wait time between consultation, simulation, and treatment appointments, can negatively impact clinical outcomes. In this pilot study, we present preliminary results of an in silico study that demonstrate the feasibility of a novel RT platform, which integrates simulation into the treatment process and enables patients to receive immediate RT after their initial RT consultation. A prospective clinical study has been approved to assess the capabilities of a novel RT platform with a high quality CBCT system for imaging guidance as well as planning. This new platform enables a novel clinical workflow that allows clinicians to review contours and plans created on diagnostic CT images prior to the initial RT consultation and allow them to approve new plans adapted on the actual simulation dataset acquired on the first treatment fraction. Four patients receiving standard of care RT (three abdomen and one thorax) consented for this study and underwent additional experimental CBCT simulation on the new platform in addition to their standard CT simulation. The CBCT simulation was taken in two setups: with a specific mold on a flat couch and without a mold on a curved couch. To demonstrate the equivalence of the new workflow to the current standard of care, the plan created on the most recent diagnostic CT images was compared to the plans adapted on the experimental simulation images and the standard CT simulation images, using a knowledge-based model. Contours were propagated from approved datasets to the new datasets through deformable image registration. All experimental simulations were completed between 14 and 21 minutes with the assistance of two therapists. The contouring, editing, and replanning process took less than one hour in all cases, in line with our experience and peer-reviewed literature. Despite notable anatomical changes observed, the dose-volume histograms (DVH) were consistent, as shown in Table 1. The novel workflow presented herein was feasible and demonstrates that the integration of simulation with image-guided RT on one single platform may unlock the potential of accelerating the RT workflow and reducing the wait time for treatment from weeks to hours.

Seasonal variability of airborne mold concentrations as related to dust in a coastal urban area in the Eastern Mediterranean.

Recent studies have demonstrated that the amount of specific airborne mold types and their concentrations increase during dust events. This study investigates the seasonal variation of airborne mold concentrations before, during, and after the dust transport in an eastern Mediterranean coastal area, Izmir city, Turkey. A total of 136 airborne mold samples were collected between September 2020 and May 2021. Two different culture media, namely Potato Dextrose Agar (PDA) and Malt-Extract Agar (MEA), were used for enumeration and genus-based identification of the airborne mold. In addition to culture media, the influences of air temperature, relative humidity, and particulate matter equal to or less than 10µm (PM10) were also investigated seasonally. The HYSPLIT trajectory model and web-based simulation results were mainly used to determine dusty days. The mean total mold concentrations (TMC) on dusty days (543 Colony Forming Unit (CFU)/m3 on PDA and 668CFU/m3 on MEA) were approximately 2-2.5 times higher than those on non-dusty days (288CFU/m3 on PDA and 254CFU/m3 on MEA) for both culture media. TMC levels showed seasonal variations (p < 0.001), indicating that meteorological parameters influenced mold concentrations and compositions. Some mold genera, including Cladosporium sp., Chrysosporium sp., Aspergillus sp., Bipolaris sp., Alternaria sp., and yeast, were found higher during dusty days than non-dusty days. Thus, dust event impacts levels and types of airborne molds and has implications for regions where long-range dust transport widely occurs.

Exploring the potential benefits of 3D printing technology in laboratory equipment: Case studies on custom lab equipment and components

Although 3D printers are becoming more common in households, they are still under-represented in many laboratories worldwide. However, this paper highlights the potential benefits of 3D printing technology in laboratory equipment. Researchers and scientists may need to learn about the potential benefits of 3D printing technology. It is essential to note that 3D printers are not just toys. They can be valuable tools for laboratory equipment, creating custom lab equipment and components, which can be difficult or expensive to obtain through traditional means. 3D printing can save time and money while increasing research efficiency. Also, 3D printers can create complex structures and models that help visualize and understand scientific concepts and create prototypes of new inventions and ideas. This study explores two examples of using 3D printing techniques, including a 3D printer-created pipette tip sorting device and a specific mold for sand samples in biocementation. The application and errors, mistakes, and challenges in materials control, with suitable solutions, were also discussed. Although 3D printers may still need to become as standard in laboratories as other types of equipment, their potential applications make them a valuable addition to any research or development team.

A novel high-throughput assay to produce ring-shaped 3D cardiac tissues from human induced pluripotent stem cells

Cardiac tissue engineering aims at creating contractile structures that can optimally reproduce the features of human cardiac tissue. These constructs, associated to the induced pluripotent stem cell (iPSC) technology, are becoming valuable tools to model some of the cardiac functions, to set preclinical platforms for drug testing, or to model cardiac pathologies. Nevertheless, the techniques used to generate engineered tissues still require expertise and produce a limited number of tissues per batch. To develop a novel assay which allows a fast, reproducible and high-throughput generation of 3D cardiac rings in a 96-well plate. A specific mold was designed to generate ring-shaped tissues around a central PEG pillar mounted on glass coverslips (Fig. 1). Cardiomyocytes derived from wild-type human iPSCs (hiPSC-CMs) were mixed with human dermal fibroblasts (HDF) and then seeded in the wells. An inhouse Matlab code was used to measure the deformation of the central pillar in time, deriving the force exerted by the tissue, and several contraction parameters. At day 14, the tissues were fixed and stained to evaluate their organization by confocal imaging. Finally, drug response of the tissues was assessed with different drugs. After seeding, the cells mix fell at the bottom of the PEG microwells and compacted around the pillars, forming 21 beating cardiac tissues per well. An iPSC-CM/fibroblast ratio of 3:1 was optimal to generate the highest number of stable tissues in time. The staining of vimentin and troponin T showed that the fibroblasts form a layer, stabilizing the iPSC-CMs which form a ring-shaped muscular fiber above. Tissue motion was monitored by real-time video-microscopy. Tissues started contracting around the pillar at D1 and their fractional shortening increased until D7, reaching a plateau at 25 ± 0.55%, that maintained up to 14 days. The average stress developed was of 1,43 ± 0,37 μN/mm2. The cardiac constructs showed a positive inotropic response to increasing extracellular calcium concentrations and isoproterenol, while verapamil induced a strong negative inotropic response. Dofetilide induced arrhythmias at low concentrations and cardiotoxic effects. We report on the development on a novel, easy-to-use, reproducible and high-throughput platform to generate cardiac tissues using hiPSC-CMs. The platform can serve for disease modeling and pharmacological testing.

Valorization of wheat bread waste and cheese whey through cultivation of lactic acid bacteria for bio-preservation of bakery products

In this work, three lactic acid bacteria (LAB) strains, specifically, Lactiplantibacillus plantarum UMCC 2996, Furfurilactobacillus rossiae UMCC 3002, and Pediococcus pentosaceus UMCC 3010, were tested in new bread-whey media composed by wheat bread and sweet cheese whey, designed as an alternative to the conventional MRS medium. The medium resulting from hydrolysis with amylase and neutrase (AN) was considered the best for the growth of all the strains. This medium was particularly optimal for the strain F. rossiae UMCC 3002, which showed an increase in growth of 114% compared to that in MRS medium. Additionally, the bio-preservative ability of the selected LAB was assessed in pectin-based coated sliced bread inoculated with Aspergillus flavus ITEM 7828, Penicillium paneum ITEM 1381, and Aspergillus niger ITEM 7090. Different LAB strain behavior was observed towards the specific molds. A good bio-preservation activity was shown from F. rossiae UMCC 3002 against A. flavus ITEM 7828 with results compared to the protection by ethanol treatment. The results obtained in this study suggest a novel strategy for the cultivation of selected starters with a bio-protection activity by valorizing bread waste and cheese whey by-products, in a circular economy perspective.

Association of Mold Levels in Urban Children’s Homes With Difficult-to-control Asthma

To assess the association of overall and specific mold levels in homes of urban children and difficult-to-control asthma.The study included 265 children from the Asthma Phenotypes in the Inner-City (APIC) study, aged 6 to 17 years old with asthma, and living in 8 urban cities across the United States. The study used 265 frozen-dust samples previously collected from the homes of APIC study-enrolled participants for analysis of mold concentrations. Although a total of 465 samples were collected during the APIC study, only the 265 samples that remained were used for post hoc analysis.The study was a cross-sectional analysis of 2 asthma cohorts: children with either difficult-to-control (DTC) and easy-to-control (ETC) asthma. DTC asthma participants required daily therapy of greater than or equal to 500 mcg fluticasone (with or without a long-acting β-agonist), and ETC asthma participants required less than or equal to 100 mcg fluticasone. Quantitative polymerase chain reaction assays were performed on frozen-dust samples that were obtained by wiping above-floor surfaces in participants’ homes using a Swiffer cloth (Procter and Gamble, Cincinnati, Ohio). The Environmental Relative Moldiness Index (ERMI) metric was used to classify mold species into 2 groups: group 1 (26 molds indicative of water damage in the home) and group 2 (10 molds commonly found indoors, even in homes without water damage). Average ERMI values and average concentrations of each of the 36 molds were compared in homes of children with DTC versus ETC asthma.No significant differences were found in average ERMI or average mold concentrations between homes of children with DTC asthma and ETC asthma. Mucor was the only mold with significantly greater average concentration in homes of children with DTC versus ETC asthma (average of 295 vs 67 cell equivalents per mg dust, P < .001). In homes with window air-conditioning (AC) units, the study found that Mucor concentration increased the probability of having DTC asthma (22% increase; 1.6 odds ratio) compared with ETC asthma.This study found that Mucor concentration is a predictor of DTC asthma, and homes with window AC units were more likely to have higher Mucor levels.Previous studies have shown an association between mold exposures and asthma. This study found that Mucor exposure in urban homes is associated with DTC asthma in a pediatric cohort with high geographic representation. Additionally, the study showed the association between elevated Mucor concentration, window AC units in urban homes, and the probability of DTC asthma. Further studies are needed to assess the role of decreasing home Mucor levels in reducing DTC asthma.URL: www.pediatrics.org/cgi/doi/10.1542/peds.10.1016/j.jaci.2021.07.047

Hybrid vacuum-robotic forming of reinforced composite laminates

A methodology is presented to implement robotic actuators into diaphragm forming of composite laminates. This Hybrid Vacuum-Robotic (HyVR) process is specifically targeted to prevent ‘bridging’ type defects. Examples are presented of successfully forming laminates with deep concave features that would otherwise be impossible by diaphragm forming. The robotically controlled end effectors apply localised pressure to concave regions during the diaphragm forming process. This force application is analogous to the incremental sheet forming process. A generalised methodology is presented which can be applied to develop a bespoke HyVR process for a specific mould. It can then inform what type of end effector should be used and how to apply it within the HyVR process. A key development included in this methodology is the use of the robot to ‘pin’ the laminate to the mould, preventing any unwanted movement. This process could enable automated production of more complex components using diaphragm forming, taking advantage of its lower tooling and equipment costs.

A toughened, transparent, anti-freezing and solvent-resistant hydrogel towards environmentally tolerant strain sensor and soft connection

Low-temperature tolerant and solvent-resistant soft electronic devices have received increasing attention due to their excellent adaptability under multiple environments. Herein, the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and zwitterionic betaine (ZB) are introduced into the Al3+ cross-linked polyacrylic acid (PAA) networks to construct a multipurpose hydrogel (PAA-Al3+/PEDOT:PSS/ZB), which exhibits superior stretchability (1457 %), tensile strength (1.43 MPa), freeze-tolerance (−35 °C) and solvent-resistant capability. Furthermore, a strain sensor with multi-environmental stability is fabricated based on this hydrogel, which could not only accurately monitor the different human motions (finger bending, writing, swallowing, breathing, walking, head-up/down and wrist-up/down) at room temperature, but also reliably distinguish the various mechanical deformations in diverse solvent media (water, cyclohexane and methylbenzene) and harsh climatic condition (−35 °C). In addition, a flexible tube-shaped PAA-Al3+/PEDOT:PSS/ZB hydrogel is also successfully developed in the specific reaction mold, which can be utilized as a soft connection for the tap or two severed glass tubes to transport different liquids benefiting from the significant mechanical toughness and anti-swelling property. It is anticipated that the as-prepared hydrogel may be a promising flexible material with multi-environmental stability applying in biomedical devices, soft robotics, electronic skins and wearable sensors under complex environments.