High-quality Materials Research Articles

In situ self-assembly of pulp microfibers and nanofibers into a transparent, high-performance and degradable film

Despite the significant properties of fossil plastics, the current unsustainable methods employed in production, usage and disposal present a grave threat to both energy and environment. The development of degradable biomass materials as substitutes for fossil plastics can effectively address the energy-environment paradox at the source. Here, we prepared novel micro-nano multiscale composite films through assembling and crosslinking nanocellulose with coniferous wood pulp microfibers. The composite film combines the advantages of microfibers and nanocellulose, achieving a maximum transmittance of 91 %, foldability, excellent mechanical properties (tensile strength: 51.3 MPa, elongation at break: 4 %, young's modulus: 3.4 GPa), high thermal stability and complete degradation within 40 days. The composite film exhibits mechanochemical self-healing and retains properties even after fracture. Such exceptional performance fully meets the requirements for substituting petroleum plastics. By incorporating CaAlSiN3:Eu2+ into the composite film, it enables dual emission of red and blue light, thereby being able to promote plant growth and presenting potential as a novel sustainable alternative for agricultural films. By assembling microfiber and nanocellulose, such novel strategy is presented for the fabrication of high-quality biomass materials, thereby offering a promising avenue towards environment-friendly resource-sustainable new materials.

AI-based Cleft Lip and Palate Surgical Information is Preferred by Both Plastic Surgeons and Patients in a Blind Comparison.

The application of artificial intelligence (AI) in healthcare has expanded in recent years, and these tools such as ChatGPT to generate patient-facing information have garnered particular interest. Online cleft lip and palate (CL/P) surgical information supplied by academic/professional (A/P) sources was therefore evaluated against ChatGPT regarding accuracy, comprehensiveness, and clarity. 11 plastic and reconstructive surgeons and 29 non-medical individuals blindly compared responses written by ChatGPT or A/P sources to 30 frequently asked CL/P surgery questions. Surgeons indicated preference, determined accuracy, and scored comprehensiveness and clarity. Non-medical individuals indicated preference. Calculations of readability scores were determined using seven readability formulas. Statistical analysis of CL/P surgical online information was performed using paired t-tests. Surgeons, 60.88% of the time, blindly preferred material generated by ChatGPT over A/P sources. Additionally, surgeons consistently indicated that ChatGPT-generated material was more comprehensive and had greater clarity. No significant difference was found between ChatGPT and resources provided by professional organizations in terms of accuracy. Among individuals with no medical background, ChatGPT-generated materials were preferred 60.46% of the time. For materials from both ChatGPT and A/P sources, readability scores surpassed advised levels for patient proficiency across seven readability formulas. As the prominence of ChatGPT-based language tools rises in the healthcare space, potential applications of the tools should be assessed by experts against existing high-quality sources. Our results indicate that ChatGPT is capable of producing high-quality material in terms of accuracy, comprehensiveness, and clarity preferred by both plastic surgeons and individuals with no medical background.

Influence of Carboxylic Acid Structure on the Kinetics of Polyurethane Foam Acidolysis to Recycled Polyol.

Closed-loop recycling of plastics is needed to bridge the gap between the material demands imposed by a growing global population and the depletion of nonrenewable petroleum feedstocks. Here, we examine chemical recycling of polyurethane foams (PUFs), the sixth most produced polymer in the world, through PUF acidolysis via dicarboxylic acids (DCAs) to release recyclable polyols. Acidolysis enables recycling of the polyol component of PUFs to high-quality materials, and while the influence of DCA structure on recycled PUF quality has been reported, there are no reports that examine the influence of DCA structure on the kinetics of polyol release. Here, we develop quantitative relationships between DCA structure and PUF acidolysis function for ∼10 different DCA reagents. PUF acidolysis kinetics were quantified with ∼1 s time resolution using the rate of carbon dioxide (CO2) gas generation, which is shown to occur concomitantly with polyol release. Pseudo-zeroth-order rate constants were measured as a function of DCA composition, reaction temperature, and DCA concentration, and apparent activation barriers were extracted. Our findings demonstrate that DCA carboxyl group proximity and phase of transport are descriptors of PUF acidolysis rates, rather than expected descriptors like pK a. DCAs with closer proximity acid groups exhibited faster PUF acidolysis rate constants. Furthermore, a shrinking core mechanism effectively describes the kinetic functional form of the kinetics of PUF acidolysis by DCAs. Measurements of acidolysis kinetics for model PUF (M-PUF) and end-of-life PUF (EOL PUF) confirm the applicability of our analysis to postconsumer materials. This work provides insights into the physical and chemical mechanisms controlling acidolysis, which can facilitate the development of efficient closed-loop PUF chemical recycling schemes.

Cultural Landscape of Industrial Heritage: Aesthetic Literacy Education of the Spatial Production Thought

As China’s economy and culture become increasingly globalized and open to exchange, students’ aesthetic views have revealed potential danger signals during the evolution of civilization, sometimes manifesting as deliberate neglect and challenge to righteous culture. This study focuses on the issues faced by contemporary aesthetic education for students, particularly the oversight by teachers during lesson preparation in identifying learning materials that are both engaging for students and have experiential educational value. Based on the immersive learning characteristics of intuitive experiential education, the study employs an exploratory case study method, utilizing the industrial heritage cultural landscape of Fanshan Town in Anhui, China, as a tool and resource for students’ aesthetic education. It constructs a knowledge system of alum culture landscape aesthetic literacy, grounded in the thought of “Harmony between Man and Nature”, centered on the elements of contemporary students’ aesthetic literacy. The findings indicate that the cultural landscape of the alum industrial heritage situates the construction of the aesthetic literacy knowledge system within a broader and more credible temporal and spatial context. This provides high-quality learning materials for the experiential teaching process, helping students draw lessons from historical reflection and enrich their aesthetic cultural literacy.

New biocatalyst produced from fermented biomass: improvement of adsorptive characteristics and application in aroma synthesis.

This study presents a novel approach to producing activated carbon from agro-industrial residues, specifically cocoa fruit peel, using solid-state fermentation (SSF) with Aspergillus niger. The process effectively degrades lignin, a major impediment in traditional activated carbon production, resulting in a high-quality carbon material. This carbon was successfully utilized for enzyme immobilization and aroma synthesis, showcasing its potential as a versatile biocatalyst. The study meticulously evaluated the physical and chemical attributes of activated carbon derived from fermented cocoa peel, alongside the immobilized enzymes. Employing a suite of analytical techniques-electrophoresis, FTIR, XRD, and TG/DTG the research revealed that fermentation yields a porous material with an expansive surface area of 1107.87 m2/g. This material proves to be an excellent medium for lipase immobilization. The biocatalyst fashioned from the fermented biomass exhibited a notable increase in protein content (13% w/w), hydrolytic activity (15% w/w), and specific activity (29% w/w), underscoring the efficacy of the fermentation process. The significant outcome of this research is the development of a sustainable method for activated carbon production that not only overcomes the limitations posed by lignin but also enhances enzyme immobilization for industrial applications. The study's findings have important implications for the agro-industrial sector, promoting a circular economy and advancing sustainable biotechnological processes.

Development and application of artificial hydraulic lime for Chinese architectural heritage restorations

Lime is commonly employed in the restoration of historic buildings due to its strength properties, which align well with the demands of architectural heritage conservation. However, recent shortages in high-quality limestone raw materials and the commercial inclusion of finely ground limestone powder in hydrated lime powder have led to significant challenges. These include low initial strength, pronounced shrinkage and cracking, and poor resistance to frost. Although natural hydraulic lime (NHL) offers moderate strength, its high cost presents an obstacle to widespread use in architectural heritage restoration. Three types of artificial hydraulic lime (AHL) — AHL1, AHL2, and AHL3 — were prepared with the objective of low cost and easy scalability. These were formulated by incorporating white cement (WC), blast furnace slag powder (BFSP), heavy calcium carbonate powder (HCCP), and industrial-grade white sugar (WS) into industrial-grade hydrated lime powder (IHLP). To align the setting time of the AHLs with the requirements of traditional builders, WS was incorporated as a retarding agent. The addition of WC, BFSP, and HCCP to IHLP resulted in enhancements over IHLP in several key aspects: compressive strength, pore structure post-hardening, dry shrinkage rate, and frost resistance. This approach will enhance the restoration quality of architectural heritage in China, leading to fewer repeated repairs and significant savings in manpower and material costs. Ultimately, AHL2 was applied in the restoration of the Confucius Temple, proving its efficacy and alignment with traditional construction requirements. This research provides valuable theoretical and practical insights for enhancing the preservation of architectural heritage.

Polarized Raman Study of First-Order Phonons in Self-Flux Grown Single-Crystalline WTe2.

Bulk single crystals of WTe2 were grown by the self-flux method and characterized by X-ray diffraction, polarized micro-Raman spectroscopy, and optical microscopy. All methods revealed a high crystalline quality, thus demonstrating the advantages of the growth method used as a starting base for the synthesis of high-quality 2D materials. In each main scattering configuration, we recorded a series of Raman spectra in different sample orientations achieved by rotating the sample around the incident laser beam. In addition to the well-established case of excitation along the c crystal axis, we also applied laser excitation along the a and b axes. Thus, scattering configurations were also realized in the XZ and YZ polarization planes, for which no comparative literature data have yet been established. In these experiments, two new Raman-active phonons with B2 symmetry and frequencies of 89 cm-1 and 122 cm-1 were identified. The obtained experimental data enabled us to derive the magnitude ratios of all three tensor elements of the A1 modes and to find their phase differences.

Prior image-based generative adversarial learning for multi-material decomposition in photon counting computed tomography

BackgroundPhoton counting detector computed tomography (PCD-CT) is a novel promising technique providing higher spatial resolution, lower radiation dose and greater energy spectrum differentiation, which create more possibilities to improve image quality. Multi-material decomposition is an attractive application for PCD-CT to identify complicated materials and provide accurate quantitative analysis. However, limited by the finite photon counting rate in each energy window of photon counting detector, the noise problem hinders the decomposition of high-quality basis material images. MethodsTo address this issue, an end-to-end multi-material decomposition network based on prior images is proposed in this paper. First, the reconstructed images corresponding to the full spectrum with less noise are introduced as prior information to improve the overall signal-to-noise ratio of the data. Then, a generative adversarial network is designed to mine the relationship between reconstructed images and basis material images based on the information interaction of material decomposition. Furthermore, a weighted edge loss is introduced to adapt to the structural differences of different basis material images. ResultsTo verify the performance of the proposed method, simulation and real studies are carried out. In simulation study of structured fibro-glandular tissue model, the results show that the proposed method decreased the root mean square error by 67 % and 26 % on adipose, 66 % and 28 % on fibroglandular, 52 % and 8 % on calcification, compared to butterfly network and dual interactive Wasserstein generative adversarial network. ConclusionExperimentally, the proposed method shows certain advantages over other methods on noise suppression effect, detail retention ability and decomposition accuracy.

Regulation of dynamic recrystallization in p-type Bi2Te3-based compounds leads to high thermoelectric performance and robust mechanical properties

Bi2Te3-based bulk materials are the best commercially available thermoelectric materials for near room temperature applications. However, the poor mechanical properties of zone melting material and inferior thermoelectric performance of powder metallurgical material restrict their large scale deployment. In this study, p-type Bi₂Te₃-based materials were prepared using the hot extrusion technique, and the underlying mechanisms for microstructure evolution were revealed. The hot extrusion speed significantly impacts the strain rate, an indicator to modulate the dynamic recrystallization (DRX) and grain growth, thereby effectively regulating the microstructures of samples. For the sample extruded at a speed of 1.0 mm min−1, the refined grain with an average grain size of 1.53 μm and an orientation factor F(110) of 0.28 is achieved. This highly textured structure and high-density low-angle boundaries (LAGBs) maintain the high carrier mobility of 264 cm2 V−1 s−1, comparable with the zone melting sample. In contrast, increasing grain boundaries, dislocations, and inherent point defects intensifies the phonon scattering and suppresses the lattice thermal conductivity to 0.73 W m−1 K−1. All these contribute to a practical high ZT value of 1.1 at room temperature. Moreover, the fine grains and high-density dislocations ensure robust mechanic properties with a compressive strength of 189 MPa and a bending strength of 139 MPa, which is a guarantee for the successful cutting of microparticles with dimensions of 100 × 100 × 200 μm3. The fabrication of high-quality materials with both high thermoelectric performance and strong mechanical properties paves the way for the miniaturization of thermoelectric modules.

Generation of genome-wide SNP markers from minimally invasive sampling in endangered animals and applications in species ecology and conservation.

High-density genotyping methods have revolutionized the field of population and conservation genetics in the past decade. To exploit the technological and analytical advances in the field, access to high-quality genetic material is a key component. However, access to such samples in endangered and rare animals is often challenging or even impossible. Here, we used a minimally invasive sampling method (MIS) in the endangered cave salamander Proteus anguinus, the olm, to generate thousands of genetic markers using ddRADseq for population and conservation genomic analyses. Using tail clips and MIS skin swabs taken from the same individual, we investigated genotyping data properties of the two different sampling types. We found that sufficient DNA can be extracted from swab samples to generate up to 200,000 polymorphic SNPs in divergent Proteus lineages. Swab and tissue samples were highly reproducible exhibiting low SNP genotyping error rates. We found that SNPs were most frequently (~50%) located within genic regions, while the rest mapped to mostly flanking regions of repetitive DNA. The vast majority of DNA recovered from swabbing was host DNA. However, a fraction of DNA recovered from swabs contained additional ecological information on the species, including eDNA from the surrounding environment and bacterial skin fauna. Most exogenous DNA recovered from swabs were bacteria (~80%), followed by vertebrates (~20%). Our results demonstrate that MIS can be used to (i) generate tens of thousands of ddRADseq markers for conservation and population genomic analyses and (ii) inform on the species health status and ecology from exogenous DNA.

Leakage mechanisms of sub-pA InGaAs/GaAs nano-ridge waveguide photodetectors monolithically integrated on a 300-mm Si wafer

We report on a comprehensive temperature dependent dark current study of high-quality InGaAs/GaAs multi quantum well waveguide photodetectors monolithically integrated on silicon. They are integrated through metalorganic vapor-phase selective-area epitaxial growth in a 300 mm CMOS pilot line. Defects resulting from the metamorphic growth of III-V devices on Si make these devices susceptible to different leakage mechanisms at higher operating temperatures. For the high-temperature operation of complex photonics-electronics integrations, understanding the leakage mechanisms of the devices has critical significance. This will help to optimize designs promptly and ensure the reliability and longevity of such devices under extreme operating conditions. The photodetector devices exhibit dark currents below 1 pA, at room temperature and −1 V bias voltage, limited by the noise floor of the measurement setup. To resolve the different leakage mechanisms contributing to the dark current, the devices were measured at elevated temperatures and the results were cross-validated with device simulations. The devices exhibited very low dark currents, with a median below 0.1 nA at 195 °C, suggesting very high-quality material growth. Through device models, leakage mechanisms related to Shockley-Read-Hall (SRH) recombination at bulk volume defects are found to be the main factor contributing to the dark current. The surface SRH recombination is found to be limited, yet affecting the forward bias dark current due to the shortening of the diffusion paths of the majority carriers. Also, the device model shows that the actual dark currents at room temperature can be as low as 0.01 pA, more than 1-order lower than the measured levels. This study emphasizes the high quality of the III-V nano-ridge waveguide devices grown on Si, which can potentially expand the capabilities of silicon photonics platforms further.

A Framework for Curriculum Literacy in Initial Teacher Preparation: Policy, Practices, and Possibilities

Across the United States, current curricular reforms are centering high-quality instructional material (HQIM) as a lever for improving classroom instruction and student achievement. While multiple legislative definitions of HQIM attend primarily to the degree of standards alignment, we expand quality to encompass rigor and cultural responsiveness. As teachers make decisions about curriculum materials, they demonstrate curriculum literacy. We conceptualize curriculum literacy as the capacity to navigate teacher identities, learner and community assets, and instructional materials. We survey the literature related to curriculum, curriculum literacy, and teacher education. We then present a framework for curriculum literacy in initial teacher preparation and describe three instructional tools for developing preservice teachers’ curriculum literacy. These tools support teachers’ practices of critically reflecting on their identities in relation to curriculum, contextualizing curricular decisions, and evaluating existing instructional materials. Implications for policy, practice, and future research are discussed.

Room-Temperature (RT) Extended Short-Wave Infrared (e-SWIR) Avalanche Photodiode (APD) with a 2.6 µm Cutoff Wavelength.

Highly sensitive infrared photodetectors are needed in numerous sensing and imaging applications. In this paper, we report on extended short-wave infrared (e-SWIR) avalanche photodiodes (APDs) capable of operating at room temperature (RT). To extend the detection wavelength, the e-SWIR APD utilizes a higher indium (In) composition, specifically In0.3Ga0.7As0.25Sb0.75/GaSb heterostructures. The detection cut-off wavelength is successfully extended to 2.6 µm at RT, as verified by the Fourier Transform Infrared Spectrometer (FTIR) detection spectrum measurement at RT. The In0.3Ga0.7As0.25Sb0.75/GaSb heterostructures are lattice-matched to GaSb substrates, ensuring high material quality. The noise current at RT is analyzed and found to be the shot noise-limited at RT. The e-SWIR APD achieves a high multiplication gain of M~190 at a low bias of Vbias=- 2.5 V under illumination of a distributed feedback laser (DFB) with an emission wavelength of 2.3 µm. A high photoresponsivity of R>140 A/W is also achieved at the low bias of Vbias=-2.5 V. This type of highly sensitive e-SWIR APD, with a high internal gain capable of RT operation, provides enabling technology for e-SWIR sensing and imaging while significantly reducing size, weight, and power consumption (SWaP).

ЭФФЕКТИВНОСТЬ ПРИМЕНЕНИЯ РАЗЛИЧНЫХ ВИДОВ УДОБРЕНИЙ ПРИ ВЫРАЩИВАНИИ КНЯЖЕНИКИ АРКТИЧЕСКОЙ (RUBUS ARCTICUS L.)

The objective of research is to develop a nutrition system for Arctic brake. The paper presents the results of research on growing Arctic brake (Rubus arcticus L.) on acidic light sod-podzolic soils in the natural and climatic conditions of the Kostroma Region. Two soil fertilization options were used: 1) azophoska 400 kg/ha (N60P60K60 as the main fertilizer + N30P30K30 top dressing); 2) the developed nutrition system, including the main organomineral fertilizer containing humic substances and bacterial spores (Bacillus subtillis, Bacillus mucilaginosus) and 3 top dressings with solutions of the mineral fertilizer Akvarin in May, June and September (10 %, 6 and 3 %, respectively). Local application of organomineral fertilizers at a dose of 500 kg/ha with 3 additional feedings of water-soluble mineral fertilizers of the Akvarin brand containing macro- and microelements has a beneficial effect on increasing the microbiological activity of the soil, ammonifiers by 25.8 %, phosphate-mobilizing bacteria by 39.1 %, its agrochemical indicators, inclu¬ding the content of organic matter by 0.4 %, mobile phosphorus and exchangeable potassium by 7.6–12.4 mg/kg, the survival rate of R. arcticus plants, the formation of the bush habitus, with the additional formation of partial shoots by 35 pcs/bush, the physiological activity of plants, expressed in an increase in the productivity of photosynthesis by 38 % and a significant increase in the yield of berries to 53.2 g/m2 (by 47.6 %). Expanding the possibility of forming R. arcticus plantations on acidic sod-podzolic soils will increase the occupancy rate of fallow soils and put them into operation. Production of berry products in the Kostroma Region as an ecologically safe region will provide enterprises engaged in the preparation of baby and dietary food with high-quality medicinal raw materials.

A Review on Carbon Fiber Reinforced Metal Matrix Composites

The manufacturing sector perpetually seeks high-quality materials capable of meeting the requirements for enhanced mechanical properties, thereby enabling their widespread application across various industries. Integrating Carbon Fibers (CFs) into metal matrices has demonstrated significant efficacy in augmenting the comprehensive attributes of the resultant composites. This comprehensive review focuses on the latest advancements and techniques involving the utilization of carbon fibers in conjunction with metal matrix material, aimed at augmenting a spectrum of mechanical attributes. Various methods used to synthesize carbon fiber reinforced metal composites have been discussed and summarized. Liquid metallurgy technique is playing important role in the fabrication of the carbon fiber reinforced metal composites.

Effects of Fineness and Morphology of Quartz in Siliceous Limestone on the Calcination Process and Quality of Cement Clinker.

With the increasing depletion of high-quality raw materials, siliceous limestone, sandstone and other hard-to-burn raw materials containing crystalline SiO2 are gradually being used to produce clinker. This study investigates the influence of the quartz content and particle size in siliceous limestone on the calcination process and the resultant quality of cement clinker. Two different siliceous limestones were grinded to different fineness, and calcinated with some other materials. The content of the clinkers was analyzed with the XRD-Rietveld method and the microstructure of the clinkers was observed with laser scanning confocal microscopy (LSCM) and field emission scanning electron microscopy (FESEM). Three key outcomes of this study provide new insights on the use of siliceous limestone in cement production, namely that (i) reducing the fineness values of siliceous limestone from 15% to 0% of residue on a 0.08 mm sieve decreases the quantity of these larger quartz particles, resulting in an increase in C3S content by up to 8% and an increase in 28d compressive strength by up to 4.4 Mpa, which is 62.30 Mpa; (ii) the morphology of quartz-either as chert nodules or single crystals-affects the microstructure of C2S clusters in clinker, finding that chert nodules result in clusters with more intermediate phases, whereas large single crystals lead to denser clusters; (iii) the sufficient fineness values of siliceous limestone SL1 and SL2 are 5% and 7% of residue on a 0.08 mm sieve, respectively, which can produce a clinker with a 28d compressive strength greater than 60 Mpa, indicating that for different kinds of quartz in siliceous limestone, there is an optimum grinding solution that can achieve a balance between clinker quality and energy consumption without having to grind siliceous limestone to very fine grades.

High-strength tile production from yellow clay with high silicon dioxide content and its reflection in ultraviolet and visible regions

Presently, there is an increasing global demand for high-quality raw materials in tile production owing to rapid urbanization. In addition, the issues of insufficient reserves and low-quality clays are resolved by exploring the potential of environmentally friendly Bilecik yellow clay with high SiO2 content. In this study, the feasibility of producing high-strength earthen tiles from yellow clay, which has a higher SiO2 content than that of commercially used clays, is investigated. X-ray diffraction, field-emission scanning electron microscopy, and X-ray fluorescence spectroscopy are employed to analyze yellow clay. The tiles are produced in the Hatipoglu Günes Tile and Brick Industry Inc. factories. Galette tiles are obtained using a vacuum press device. Then, the galette tiles are fired at temperatures of 900, 950, and 1000 °C in an electric and Hoffman furnace. The tile fired at 1000 °C exhibits the highest transformed flexural strength (305.371 kg/cm2), which is 2.55 times higher than that specified in the TS EN 1304:2016 standard (Turkish standard-European norm). In addition, reflectance measurements are performed in ultraviolet and visible regions through UV–VIS and Fourier-transform infrared spectroscopy; the results confirmed that the galette tiles are reflected in the UV-C region. Therefore, it can be concluded that galette tiles exhibit sterilization and disinfectant effects under appropriate conditions. The usability of yellow clay with high SiO2 content in industry, the availability of high-strength products, and its production stages will create an important database for literature.

DreamMat: High-quality PBR Material Generation with Geometry- and Light-aware Diffusion Models

Recent advancements in 2D diffusion models allow appearance generation on untextured raw meshes. These methods create RGB textures by distilling a 2D diffusion model, which often contains unwanted baked-in shading effects and results in unrealistic rendering effects in the downstream applications. Generating Physically Based Rendering (PBR) materials instead of just RGB textures would be a promising solution. However, directly distilling the PBR material parameters from 2D diffusion models still suffers from incorrect material decomposition, such as baked-in shading effects in albedo. We introduce DreamMat , an innovative approach to resolve the aforementioned problem, to generate high-quality PBR materials from text descriptions. We find out that the main reason for the incorrect material distillation is that large-scale 2D diffusion models are only trained to generate final shading colors, resulting in insufficient constraints on material decomposition during distillation. To tackle this problem, we first finetune a new light-aware 2D diffusion model to condition on a given lighting environment and generate the shading results on this specific lighting condition. Then, by applying the same environment lights in the material distillation, DreamMat can generate high-quality PBR materials that are not only consistent with the given geometry but also free from any baked-in shading effects in albedo. Extensive experiments demonstrate that the materials produced through our methods exhibit greater visual appeal to users and achieve significantly superior rendering quality compared to baseline methods, which are preferable for downstream tasks such as game and film production.

Quality Control to Reduce Appearance Defects at PT. Musical Instrument

This research was conducted at PT. Musical Instruments that aim to analyze quality control to reduce appearance defects in piano products on the assembling production line. The problem faced by the company is the high level of product defects which has an impact on decreasing quality and customer satisfaction. The research method used is Six sigma with a DMAIC (Define, Measure, Analyze, Improve, Control) approach. This type of research is quantitative, with data collected in the form of the number of production defects in pianos. To analyze the causes of defects, a fishbone diagram with 4M + 1E factors is used, namely Man, Machine, Method, Material, and Environment. The results of the analysis show that the main factors causing appearance defects in piano products include incompatibility with work methods, lack of worker training, use of non-standard materials, suboptimal jig conditions, and unsupportive working environment. Based on these findings, improvement proposals are given in the form of improving standard operating procedures, regular training for workers, the use of high-quality materials, regular maintenance and calibration of jigs, and improvement of work environment conditions. The implementation of this improvement proposal is expected to reduce the number of appearance defects in piano products, improve product quality, and meet the quality standards expected by PT. Musical instrument.

Isolation and identification of primary cells: A comprehensive primary cell culture experiment for graduate students.

Experimental teaching is an important part of postgraduate training in basic and clinical medicine. While primary cell isolation and identification are among the most important research techniques for medical graduate students, most graduate students do not understand and master these techniques before starting their research experience. In particular, many students lack training in this field, and high-quality teaching and learning materials are still very sparse. Here, we designed a practical experiment course for graduate students engaged in research. The target students usually have research projects involving primary cell culture in their future research, making the course highly applicable for the students. The lab exercise focused on the methods of primary cell isolation (including mechanical grinding method, explant culture method and enzymatic digestion method) and identification (including flow cytometry, immunofluorescence, and periodic acid-Schiff (PAS) staining). It aimed to help students master the conceptual, principle, technical, operation, and analytical skills related to primary cell culture and contributed to their foundation for future research. Students generally reflect that they have initially mastered the isolation and identification of primary cell culture as a result of the course. Student feedback also indicates significantly increased confidence in the practical application of primary cell culture in the future. Here, we provide our experience for others who may want to implement similar courses.