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Constructing “constant-holistical shadow” space for universities in Guangzhou under the various roads orientation
Full text linkThe university campus in Guangzhou city, China, are heavily exposed to the sun in the summer, and it is essential to construct a Constant-holistical Shadow (CHS) space that allows university teachers and students to remain in the shadow during their outdoor activities within a certain range of time and during the entire activity period. In this paper, based on the date period in need of shadow for the outdoor activities of university teachers and students in Guangzhou, the CHS spaces under 4 typical orientations, east-west, south-north, southeast-northwest, and northeast-southwest, were simulated by Autodesk Ecotect Analysis. The correlation between the objects blocking the sunlight (sunlight-blockers) and the simulation results is analyzed, to explore the construction and design method of CHS space under the difference of the orientations, and to form a process of designing CHS space that can be applied to different orientations of the building environment. Finally, the feasibility and scientific validity of these methods are simulated and verified step by step using a campus environment in a university in Guangzhou as an example, hoping to provide reference ideas and directions for the planning and design of universities in Guangzhou and its similar latitudes, as well as for the design of buildings and their renovation
Functionalized cascaded tapered optical fiber sensor for simultaneous detection of dengue II E and SARS-CoV-2 S proteins
No full textThis work demonstrates a label-free dual-sensing biosensor utilizing cascaded single-mode tapered fiber (SMTF) for the concurrent detection of Dengue II envelope (E) and SARS-CoV-2 spike (S) proteins. Two fiber tapers of different dimensions were employed in-line, with each taper functionalized with specific complementary antibodies to the targeted antigens. The cascaded interferometric effect yielded composite spectral output that exhibited discrete response toward localized refractive index changes due to binding of antigens and antibodies. Consistent red shifts were observed with increasing concentration of the targeted analyte, which led to sensitivity values of 6.91 nm/nM for SMTF1 and 9.96 nm/nM for SMTF2, with a detection limit of 0.1 pM. This dual-sensing platform demonstrates high sensitivity and specificity, rapid response times, and the potential for integration into portable diagnostic devices, presenting it as a promising tool for point-of-care diagnostics and simultaneous detection of multiple disease biomarkers
Innovative deep eutectic solvent approach vs. conventional alkaline for kenaf seed protein extraction: a comprehensive comparison of structural, thermal, nutritional and techno-functional properties
No full textThis study was the first to compare the effects of innovative deep eutectic solvent-based green extractant (ChCl:U and ChCl:Gly) and conventional alkaline solubilisation-acid precipitation (CA) approaches on kenaf seed protein extractability, structural, thermal, nutritional and techno-functional properties. Both CA and ChCl:U methods showed better protein extractability than ChCl:Gly. DES-based extraction induced lesser structural changes in kenaf seed protein compared to CA method. All proteins displayed high digestibility, but DES extraction produced more balanced amino acid ratios. Both CA and ChCl:U methods exhibited superior functional performance at all the tested pH compared to ChCl:Gly. Notably, CA demonstrated superior emulsification properties, whereas ChCl:U exhibited the highest foaming properties. The emulsification and foaming activities with all extraction methods were the highest in alkaline conditions, while better stabilities were observed in acidic conditions. Overall, the DES protein extraction method using ChCl:U can be employed as green alternative for extracting kenaf seed protein
Some properties of bio-based epoxy vitrimers with activated carbon derived from oil palm biomass; effects of curing ratio and filer content
Full text linkThe increasing demand for recyclable, high-performance adhesives in engineered wood systems has led to growing interest in dynamic covalent resins. This study investigates a bio-based epoxy vitrimer reinforced with activated carbon derived from palm kernel shell (PKS), a lignocellulosic byproduct of the oil palm industry. The vitrimer matrix, formulated using Diglycidyl Ether of Bisphenol A (DGEBA) and a disulfide-based curing agent (2-aminophenyl disulfide), enables thermal reprocessability and self-healing via dynamic exchange reactions.
Formulations varied epoxy-to-curing agent ratios (1:1.4, 1:1.6, 1:1.8) and activated carbon loadings (0.5–1.5 wt%). Mechanical, thermal, and self-healing properties were evaluated using tensile testing, TGA, DMA, FESEM, and FTIR. The 1:1.6 ratio with 1.0 wt% filler demonstrated the highest mechanical and thermal performance, including dual glass transitions, enhanced crosslinking, and improved char residue. In contrast, the 1:1.8 formulation achieved the highest self-healing efficiency (74%), attributed to increased chain mobility. FTIR confirmed strong N–H and Si–O–Si bonding, while FESEM revealed microstructural recovery. However, excessive filler content (1.5 wt%) caused agglomeration and reduced performance.
These findings revealed that vitrimer performance can be tailored through formulation tuning, supporting the development of renewable, reprocessable adhesives for engineered wood composites. Future research will investigate adhesion to wood substrates, long-term durability, and catalyst-assisted healing to further enhance sustainability and functional performance
Study of airflow dynamics and particle transport in the upper respiratory system using numerical simulation
Full text linkThe increase in pollution levels in recent years has increased the prevalence of pulmonary diseases. The accumulation of pollutant particles in the pulmonary tract is speculated to be one of the major reasons for the increase in chronic cases. This necessitates the study of the mechanism of particle deposition in human airways to develop better drug delivery systems. Aerosolized forms of drugs are commonly used to treat pulmonary diseases. The current study employed computational fluid dynamics (CFD) and discrete element method (DEM) techniques to study airflow patterns and particle deposition phenomena. An idealized 3D CAD model was developed based on available literature. A discretized finite-volume model was tested to ensure an independent solution. A user-defined function (UDF) was used to simulate realistic breathing dynamics for the respiration cycle. The aerosol particles of the calculated volume were mixed into the airflow domain. The analysis was conducted using ANSYS FLUENT CFD solver. This study found several regions of high turbulence in the upper human airways, with secondary flow structures exhibiting bifurcations and the glottal region. The study also found that the oral cavity and oropharynx regions with higher turbulence intensity had a concentrated deposition of particles. Most of the aerosol particles (5μm) were transported into the alveolar sacs, where they were absorbed into the bloodstream. The oral cavity and oropharynx have the highest pressure and particle deposition efficiency, while the trachea plays a crucial role in particle deposition during inhalation due to weak oscillatory flows and turbulence, especially in the tracheal region and lower respiratory tract. The oral cavity has the highest efficiency at 7.32%, while the trachea has the lowest at 0.4%. The overall deposition efficiency across all regions is 9.078%.This study did not account for the breakup of aerosol particles. Aerosol particles can break apart due to airflow and collisions, affecting their size and deposition efficiency. Ignoring this breakup could lead to inaccurate results, making accurate dosimetry essential for inhalation studies
Digital technologies and sustainable development: an insight from corporate sector
No full textThe excessive utilization of industrial output has drawn significant attention from authorities toward sustainable development. Given the substantial environmental challenges posed by the industrial sector, sustainable development has emerged as a paramount concern for scholars and organizations alike. In this context, considerable emphasis has been placed on the significance of digitization. Digital technologies, particularly blockchain technology (BCH) and digital finance (DF), are transforming the landscape of business and the economy, facilitating corporate sustainable development (CSD), enhancing corporate social practices, and fostering green innovation. Through the application of various econometric strategies using the Chinese business sector as a sample of the study, we found that BCH effectively promotes green innovation and corporate social activities. Additionally, our analysis underscores the critical role of DF in advancing corporate social practices and green innovation. Notably, we highlight the importance of human capital as a moderating factor that strengthens the relationships between BCH and CSD, as well as between digital finance and CSD. This study offers novel insights into ways, digital technology can enhance corporate sustainability practices and presents a framework that may be of significant utility to policymakers and decision-makers
Extraction variables optimization on phenolics content and antioxidant activities of in-vitro propagated leaves of Curcuma caesia Roxb. using response surface methodology
Full text linkCurcuma caesia Roxb. (Zingiberaceae) is one of the endangered species in the genus Curcuma that possesses numerous beneficial bioactive compounds that are responsible for various pharmacological properties including anti-cancer, anti-asthmatic, anti-diabetic, and others. In the past few years, the number of C. caesia plants was reported to have drastically decreased due to over-harvesting activity. To conserve this species, plant tissue culture method was used as a propagation tool for the mass production of C. caesia plantlets. Hence, this study aimed to optimize the extraction of phenolics content and antioxidant activities using response surface methodology. In this study, central composite design (CCD) was used to investigate the effects of three independent variables, namely solvent-solid ratio (mL/g), methanol concentration (%), and extraction temperature (°C), on phenolics content and antioxidant activities. Based on the results, the optimal extraction condition was achieved using 54.02 mL/g solvent-solid ratio, 70% methanol concentration, and 70 °C of extraction temperature
Radiation-induced damage to concrete biological shielding materials: a state-of-the-art review
Full text linkConcrete is the primary material for such shielding due to its mechanical and structural properties, suitable for neutron and gamma radiation protection. This review provides a comprehensive examination of the impact of nuclear irradiation on the structural integrity of concrete used in biological shielding within nuclear power plants (NPPs). This review highlights the critical role of the hydrogen content of concrete in attenuating neutron flux and its versatility in shape, density, and cost-eff ectiveness. The review was systematically collected and reviewed previous research papers on the topic, focusing on studies that address the degradation of mechanical properties in concrete exposed to gamma and neutron radiation. Our methodology involved an extensive literature search, critical analysis, and synthesis of fi ndings from peer-reviewed journals, conference proceedings, and technical reports that specifically address the degradation of mechanical properties in concrete structures exposed to gamma and neutron radiation. Gamma radiation induces radiolysis in hydrated cement paste, while neutron radiation causes alterations in the crystalline structure of aggregates, leading to volumetric expansion and reduced mechanical strength. Additionally, this review highlights the combined effects of chemical attacks, moisture, and elevated temperatures on concrete degradation during reactor operation. The key findings underscore the need for further research into the degradation mechanisms of concrete biological shielding, emphasizing the influence of various types of nuclear radiation. This understanding is crucial for ensuring concrete’s long-term durability and effectiveness in NPPs, thereby contributing to the safe and sustainable operation of nuclear energy facilities
System of caputo fractional differential equations for tuberculosis disease with effects of immune and asymptomatic patients classes: theoretical and analytical solutions
Full text linkTuberculosis is an extremely serious disease that affects a large number of people around the world. In this paper, we investigate epidemic model of TB in the sense of Caputo derivative, integrating the impact of immune and asymptomatic classes. The primary challenge is accurately estimating the disease spread and assessing the effectiveness of human immunity. We establish the qualitative analysis of the constructed model, which include positivity, existence, and uniqueness of the solution, and Hyers–Ulam stability of the solution. The computed basic reproduction number R0 is used to obtain the normalized forward sensitivity index for each parameter with the purpose of identifying key parameters essential for the disease control. Numerical analysis are carried out utilizing the homotopy perturbation method and fractional differential transform method. The comparative study of integer order P = 1 is done to validate the numerical performance. Our findings suggest that immune class and asymptomatic class individuals play a significant role in reducing/spreading TB prevalence and burden within human populations. We noticed a significant decline in the susceptible and asymptomatic classes as a result of self–immune and adequate treatment. These findings contribute to the management and control of the tuberculosis disease
Jin opera huhu: a critical sound analysis of cultural representation in conventional Jin opera
Full text linkA comprehensive acoustic analysis was carried out for the huhu, a betelwood instrument from the Jin opera. Techniques included an acoustic visualiser and Fast Fourier Transform (FFT). The harmonic structure, frequency distribution, and timbre quality of the instrument were investigated, focusing on the effect of the use of leather finger cuff on the sound produced. Spectral analyses revealed complex overtones and distinctive spectral patterns for different playing techniques, ranging from 324.47 to 10,277.08 Hz. Finger cuffs significantly altered the harmonic content and timbre. The study utilised high fidelity equipment to conduct multiple recordings under controlled conditions to capture subtle acoustic changes. Statistical analysis of the frequency data revealed a consistent overtone structure, while an acoustic visualiser examined the relationship between playing technique and sound intensity. The analyses emphasised how traditional playing methods (particularly fretting) affect acoustic output. By documenting the current acoustic characteristics of the huhu, this work provides insight into its musical and cultural significance, contributes to the preservation of traditional musical heritage and provides a scientific basis for understanding the unique acoustic characteristics of betel nut wood