Absorption Rate Research Articles

New insights on impact wear of polycrystalline diamond compact: Effect of interface state on kinetic response and damage behavior

The impact wear of polycrystalline diamond compact (PDC) cutters caused by the discontinuous cutting during the drilling process significantly affects the lifespan and efficiency of the drilling tools. Different PDC impact contact interface states are realized through the selection of impact mating materials. Understanding the effects of different interface states on the kinetic response, damage behavior and impact wear mechanism of PDC is significant in guiding the practical design of material structures with excellent impact wear resistance. Therefore, the kinetic response and damage behavior of PDC impact with different mating materials are investigated. The results show that the kinetic response and damage behavior of PDC are correlated with the mechanical properties of the mating material and physicochemical changes at the impact surface interface. Adhesion and filling resulting from strong covalent bonding and filling effects mitigate the interfacial stress and reduce the average impact force of SiC and Al2O3. Moreover, brittle fracture and filling effects increase the consumption of kinetic energy of SiO2, resulting in an energy absorption of up to 86 %. In addition, the strong covalent bonding effects exacerbated the damage to the PDC interfaces, leading to the internal fracture of diamond particles and detachment at grain boundaries. Furthermore, the filling effect formed plays a specific protective role for diamonds. However, it increases the energy absorption rate and reduces the mating material damage efficiency. In this work, the relationship between impact interface state and impact wear mechanism has been established by understanding the kinetic response, damage morphology, and structural evolution.

Protective effect of radiofrequency exposure against menadione-induced oxidative DNA damage in human neuroblastoma cells: The role of exposure duration and investigation on key molecular targets.

In our previous studies, we demonstrated that 20 h pre-exposure of SH-SY5Y human neuroblastoma cells to 1950 MHz, UMTS signal, at specific absorption rate of 0.3 and 1.25 W/kg, was able to reduce the oxidative DNA damage induced by a subsequent treatment with menadione in the alkaline comet assay while not inducing genotoxicity per se. In this study, the same cell model was used to test the same experimental conditions by setting different radiofrequency exposure duration and timing along the 72 h culture period. The results obtained in at least three independent experiments indicate that shorter exposure durations than 20 h, that is, 10, 3, and 1 h per day for 3 days, were still capable to exert the protective effect while not inducing DNA damage per se. In addition, to provide some hints into the mechanisms underpinning the observed phenomenon, thioredoxin-1, heat shock transcription factor 1, heat shock protein 70, and poly [ADP-ribose] polymerase 1, as key molecular players involved in the cellular stress response, were tested following 3 h of radiofrequency exposure in western blot and qRT-PCR experiments. No effect resulted from molecular analysis under the experimental conditions adopted.

Influence of the radiofrequency applicators arrangement on the sizes of ablative zones inside hepatic tumor

Radiofrequency (RF) ablation is a popular therapeutic technique for heating solid tumors that are medically unsuitable for resection or other treatments. Thermal ablation applicators create high-frequency electromagnetic fields (EMFs) within the tumor site, which causes heating, coagulation, and ultimately death of the cancer cells. The aim of this study is the numerical analysis of the temperature distributions, ablation zones, and specific absorption rates (SAR) during RF ablation in relation to an ellipsoidal shaped tumor placed in the model of liver tissue. The source of heat is a three-element system of RF needle applicators operating at a frequency 100 kHz, with a given electrode potential, inserted into the tumor. In order to obtain an appropriate temperature distribution in the target area, the Laplace equation coupled with the Pennes equation were solved using the finite element method (FEM). The arrangement effect of three needle-type applicators on the resultant thermal profiles and the volumes of ablation zones were analyzed and compared. In addition, the ablation zones for various angles of the RF applicator placed in the center of the tumor were analyzed. The paper shows that in order to control temperature distribution and ablation zones the proposed system of RF applicators and the arrangement of electrodes can be successfully applied in hepatocellular carcinoma treatment.

Health Hazards Associated with Dietary Exposure of Female Rat to Cadmium-Contaminated Cooked Rice: Biochemical, Hormonal, and Histopathological Analysis.

The actual exposure, bioavailability, and body burden of dietary cadmium (Cd) vary with the food matrix. Here, we evaluated the health hazards of 45-day long-term exposure of growing Sprague-Dawley (SD) female rats to a natural and endogenous Cd-contaminated brown and white cooked rice dietary model. Cd was found mainly in the duodenum, kidney, and liver; the cecum and colon also contained substantial amounts of Cd in rats fed Cd-contaminated cooked white rice (cWR-test) but not Cd-contaminated cooked brown rice (cBR-test). Damage due to Cd exposure was reflected in liver dysfunction, altered estradiol levels, and distinctive pathologies in organ systems, although urinary Cd (U-Cd) excretion and blood Cd (B-Cd) were not detectable, suggesting that these are not the most accurate or appropriate biomarkers for evaluating dietary Cd exposure. Brown rice, despite being higher in Cd, can reduce Cd absorption and distribution in organs and increase the volume of Cd-containing feces, even achieving slightly higher excretion and lower apparent absorption rates of Cd than white rice, thereby reducing Cd damage to the body. The beneficial components of brown rice such as more dietary fiber, rice bran oil and polyphenol were speculated therefore to confer a degree of protection or repair. Nevertheless, the high apparent absorption levels observed here (> 5%) and signs of significant physical damage indicate that more stringent Cd intake guidelines and measures are needed to minimize Cd levels in rice.

Broadband Solar Absorber and Thermal Emitter Based on Single-Layer Molybdenum Disulfide.

In recent years, solar energy has become popular because of its clean and renewable properties. Meanwhile, two-dimensional materials have become a new favorite in scientific research due to their unique physicochemical properties. Among them, monolayer molybdenum disulfide (MoS2), as an outstanding representative of transition metal sulfides, is a hot research topic after graphene. Therefore, we have conducted an in-depth theoretical study and design simulation using the finite-difference method in time domain (FDTD) for a solar absorber based on the two-dimensional material MoS2. In this paper, a broadband solar absorber and thermal emitter based on a single layer of molybdenum disulfide is designed. It is shown that the broadband absorption of the absorber is mainly due to the propagating plasma resonance on the metal surface of the patterned layer and the localized surface plasma resonance excited in the adjacent patterned air cavity. The research results show that the designed structure boasts an exceptional broadband performance, achieving an ultra-wide spectral range spanning 2040 nm, with an overall absorption efficiency exceeding 90%. Notably, it maintains an average absorption rate of 94.61% across its spectrum, and in a narrow bandwidth centered at 303 nm, it demonstrates a near-unity absorption rate, surpassing 99%, underscoring its remarkable absorptive capabilities. The weighted average absorption rate of the whole wavelength range (280 nm-2500 nm) at AM1.5 is above 95.03%, and even at the extreme temperature of up to 1500 K, its heat radiation efficiency is high. Furthermore, the solar absorber in question exhibits polarization insensitivity, ensuring its performance is not influenced by the orientation of incident light. These advantages can enable our absorber to be widely used in solar thermal photovoltaics and other fields and provide new ideas for broadband absorbers based on two-dimensional materials.

Theoretical study of a triple-band tunable terahertz metamaterial absorber with polarization insensitive and high refractive index sensing based on bulk Dirac semimetal

In this paper, a triple-band metamaterial absorber in the terahertz frequencies is proposed, and its refractive index sensing characteristics are analyzed, where the bulk Dirac semimetal (BDS) periodic array is on top of a photonic crystal slab backed with a metal ground plane. The simulation results show that the absorber achieves three perfect absorption peaks in the range of 3.4–5.2 THz, whose absorption rates are over 96%, and a maximum quality factor (Q) of 74.1. The designed absorber exhibits excellent polarization insensitivity and dynamic tunability; further, the tuning of the Fermi energy level of BDS enables the dynamic adjustment of absorption frequencies and absorption rates of these peaks. By analyzing the distributions of the electromagnetic field and different structural parameters, it is revealed that the absorber mainly dissipates the electromagnetic wave through coupled resonance and localized surface plasmon resonance (LSPR) effects to achieve perfect absorption. Further, the metamaterial absorber shows the capacity to detect analytes with varying refractive indices, and the absorber has a maximum sensitivity S of 405 GHz/RIU with high detection accuracy. This work provides novel design options for triple-band terahertz metamaterial absorbers and their potential applications in refractive index sensing.

Pharmacokinetic and Pharmacodynamic Interaction of Finerenone with Diltiazem, Fluconazole, and Ritonavir in Rats.

Finerenone, a novel selective non-steroidal mineralocorticoid receptor antagonist, has been indicated in chronic kidney disease associated with type 2 diabetes mellitus. Considering the potential complications of diabetes, finerenone can be co-administered with various drugs, including fluconazole, diltiazem, and ritonavir. Given that finerenone is a substrate of cytochrome P450 (CYP) 3A4, the concurrent administration of finerenone with CYP3A4 inhibitors (diltiazem or fluconazole or ritonavir) could potentially lead to drug interactions, which may cause adverse events such as hyperkalemia. No studies have investigated interactions between finerenone and diltiazem or fluconazole or ritonavir. Therefore, this study aims to investigate the pharmacokinetic interaction of finerenone with diltiazem or fluconazole or ritonavir and to evaluate the impact of fluconazole on the pharmacodynamics of finerenone. The pharmacokinetic study included four rat groups (n=8 rats/group), including a control group (finerenone alone) and test groups (finerenone pretreated with diltiazem or fluconazole or ritonavir) using both non-compartment analysis (NCA) and population pharmacokinetic (pop-PK) modeling. The pop-PK model was developed using non-linear mixed-effects modeling in NONMEM® (version 7.5.0). In the pharmacodynamic study, serum potassium (K+) levels were measured to assess the effects of fluconazole on finerenone-induced hyperkalemia. The NCA results indicated that the area under the plasma concentration-time curve (AUC) of finerenone increased by 1.86- and 1.95-fold when coadministered with fluconazole and ritonavir, respectively. In contrast, diltiazem did not affect the pharmacokinetics of finerenone. The pharmacokinetic profiles of finerenone were best described by a one-compartment disposition with first-order elimination and dual first-order absorption kinetics. The pop-PK modeling results demonstrated that the apparent clearance of finerenone decreased by 50.3% and 49.2% owing to the effects of fluconazole and ritonavir, respectively. Additionally, the slow absorption rate, which represents the absorption in the distal intestinal tract of finerenone, increased by 55.7% due to the effect of ritonavir. Simultaneously, a pharmacodynamic study revealed that finerenone in the presence of fluconazole caused a significant increase in K+ levels compared with finerenone alone. Coadministration of finerenone with fluconazole or ritonavir increased finerenone exposure in rats. Additionally, the administration of finerenone in the presence of fluconazole resulted in elevated K+ levels in rats. Further clinical studies are required to validate these findings.

Robust Multi-Band DNG metamaterial absorber for GPS (L1), ISM, and 5G application with Enhanced polarization and angle stability

This research introduces a triple-band metamaterial absorber characterized by insensitivity to both polarization and incident angles. The structure includes square ring resonators on the upper side and a continuous metal ground on the lower side, separated by an FR4 substrate. At the lowest operating frequency, the unit cell’s thickness, and length measure 0.0128λ and 0.156λ, respectively. Under normal incidence, the proposed absorber demonstrates three clear absorption peaks at 1.56, 2.43, and 3.36 GHz, achieving absorption rates of 98 %, 99 %, and 97 %, respectively. The absorption response exhibits variation with incident angles up to 70° for both TM and TE polarizations due to its high-level symmetry. This configuration attains negative permittivity and permeability suitable for operational frequencies in the L-band and S-band. The study examines the electric field, impedance, and surface current to provide additional evidence for the absorption analysis. A validated RLC circuit equivalent to the proposed structure has been confirmed using Advanced Design System (ADS). The results indicate a slight deviation, especially at frequencies beyond the resonance frequencies. The structure underwent fabrication and testing in an anechoic chamber, revealing a strong correlation between the simulated and measured results. The suggested absorber holds promise for ISM applications, radar systems, sensing technologies, and energy harvesting systems.

Improvement of the gel properties of curdlan gel by hydrogen bonding interaction with trehalose

This study investigated the effect of trehalose addition (0.5–2.0%) on the gelation properties of curdlan gels were investigated. The results demonstrated that the optimal gelation performance of curdlan-trehalose composite gel was determined at trehalose concentration of 1.0% with preferable water holding capacity, water absorption rate, and freeze-thaw stability. The gelation behavior of the curdlan-trehalose composite gel showed a more intense network structure with increasing storage modulus (G′), loss modulus (G″), and deceasing tan δ at the trehalose concentration in the range of 0%–1%. And the highest gel strength was also observed in 1% trehalose addition. Moreover, the structures characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Low field nuclear magnetic resonance (LF-NMR) and scanning electron microscope analysis (SEM) all revealed that the addition of trehalose strengthened the hydrogen bonding interaction with curdlan to create a much denser network of composite gel, which would provide a better mechanistic insight of the curdlan-trehalose gel in practical application potentials in food and medicine.

Effect of printing temperature on the mechanical properties of 3D printed polyphenylene sulfide (PPS) during simple and repeated impact tests

AbstractFused filament manufacturing (FFF), also known as 3D printing, is one of the most commonly used additive manufacturing techniques for creating high-quality materials. This process demonstrates the intricacies and challenges involved in choosing appropriate manufacturing parameters to achieve the desired outcomes. Among these critical parameters is the nozzle temperature, which can be adjusted to enhance the mechanical properties of the 3D-printed Polyphenylene Sulfide (PPS) parts. The main objective of this study is to investigate the influence of the printing temperature on the mechanical properties and failure characteristics of 3D printed polyphenylene sulfide (PPS) parts during impact testing. To do this, a series of simple and repeated impact tests were carried out on printed PPS samples in the nozzle temperature range (320–350 °C). CHARPY tests were carried out on the samples manufactured with different sequences for the optimal orientation of the filaments. Furthermore, the impact energy absorption capacity and the induced damage as a function of nozzle temperature were evaluated. CHARPY test results showed that samples with stacking sequence (0/0) had the best impact resistance and specific absorbed energy (SEA). This sequence, printed horizontally, was used to test different print temperatures in single and repeated impact tests. Furthermore, the results indicated that samples printed with a nozzle temperature of 340 °C exhibited higher CHARPY impact resistance and specific absorbed energy (SEA), with a percentage difference of 45.57%, 41.95% and 44.21% compared to samples printed with nozzle temperatures of 320 °C, 330 °C and 350 °C respectively. For repeated impact tests, the results also show that samples printed with a nozzle temperature of 340 °C have a higher initial energy absorption rate and a greater number of impacts before complete failure of the sample. This result proves also that the changing of nozzle temperature does not have a significant effect on the induced damage after CHARPY and repeated impact.

CO2 capture performance of AMP-EAE amine blends: Absorption in the microchannel and desorption from saturated solutions

Blended organic amine solutions are considered an effective strategy for developing highly efficient and low energy-consuming absorbents due to the possibility of combining the advantages of single amine. The 2-amino-2-methyl-1-propanol (AMP) and 2-(ethylamino)ethanol (EAE) amine blends were prepared in three molar ratios: blend-1 (nAMP:nEAE = 3:1), blend-2 (nAMP:nEAE = 1:1), and blend-3 (nAMP:nEAE = 1:3). The impacts of gas-liquid flow rate, amine concentration, molar ratio, temperature, and CO2 concentration on absorption performance were investigated using the serpentine microchannel. Additionally, the effects of amine concentration and molar ratio on the desorption performance of saturated solutions were also explored. The performance of amine blends in absorption and desorption was evaluated by measuring absorption rate, efficiency, and loading, as well as desorption efficiency, energy consumption, cycle capacity, and average desorption rate. The desorption results were compared to those of the benchmark solvent, 30 wt% MEA, under identical operating conditions. The results indicate that the 25 wt% blend-2 solution performs exceptionally well, exhibiting a 15 % increase in absorption efficiency compared to the AMP aqueous solution at a gas-liquid ratio of 20. Additionally, the cycle capacity and average desorption rate are 1.7 times higher than those of the 30 wt% MEA solution. Notably, the energy consumption of the 25 wt% blend-2 solution for desorption is only 60 % of the 30 wt% MEA solution.

Design and Performance Analysis of a Low-Profile Dual-Band Antenna with Low Specific Absorption Rate Using Textile Materials for Wearable and RF Energy Harvesting Applications

Design and Performance Analysis of a Low-Profile Dual-Band Antenna with Low Specific Absorption Rate Using Textile Materials for Wearable and RF Energy Harvesting Applications

Study on Production Characteristics and Change in Production Location of Pottery Excavated from DongOe-dong Site in Goseong

As a result of scientific analysis of 26 pottery excavated from the DongOe-dong site in Goseong, pottery with various firing degrees was confirmed, ranging from low-firing pottery with mica minerals detected to high-firing pottery with high-temperature minerals such as cristobalite and mullite detected. In addition, low-firing pottery has an absorption rate of 9.7∼25.8% and generally shows high saturation value. On the other hand, high-firing pottery has low absorption rate and saturation value, so the physical characteristics of the pottery show a high correlation with the group classified by XRD analysis. Pottery with a low firing degree commonly contains fine-grained mineral particles and has a similar composition of trace elements such as Rb, Ba, and Sr. And they were most abundantly excavated from the No. 1-1 moat. However it was confirmed that there is a difference in the production area because compositions of the rare earth elements are distributed in two areas in the graph. High&intermediate-firing pottery samples are observed to have a vitrified base matrix and relatively less temper minerals. And their contents of Rb, Sr, and Ba are significantly different from low-firing pottery. In the composition of rare earth elements, they are all distributed in same area as one of the separated areas of low-firing pottery, so it is highly likely these pottery were produced in the same or nearby production region regardless of the firing degree. As a result of checking up the composition of rare earth elements according to the archaeological chronology of pottery, it is estimated that there was a change in the production region of the pottery introduced into the DongOe-dong site around 250 AD.

Enhanced mechanical, thermal, water and UV aging resistance properties of bamboo fiber/HDPE composites through silane coupling agent modified nano-SiO2-TiO2

Nano-TiO2 is widely employed to enhance the properties of plant fiber reinforced thermoplastic polymer composites due to its chemical inertness, anti-aging, and anti-bacterial properties. However, the enhancement of bamboo fiber/high-density polyethylene (BF/HDPE) composites is limited by the high photocatalytic activity of nano-TiO2 and its poor compatibility with the BF/HDPE matrix. This study employs an organic-inorganic co-modification to prepare BF/HDPE composites reinforced with silane coupling agent KH550 modified nano-SiO2 coated nano-TiO2 (KH550/SiO2-TiO2) by spray coating and melt mixing methods, and the properties of the composites were tested and characterized. The effects of KH550 and KH550/SiO2-TiO2 content on the properties of modified BF/HDPE composites, including mechanical properties, water absorption, thickness swelling rate, water contact angle, thermal stability, and UV aging resistance，which were characterized using methods of mechanical tests, FTIR, UV-Vis, XPS and SEM, both before and after modification. The results indicate that KH550 effectively improves the agglomeration phenomenon and enhances the dispersibility of nano-SiO2-TiO2 in the BF/HDPE composites. The optimal thermal stability is achieved when the BF/HDPE composites modified with a 5 wt% KH550/SiO2-TiO2, while BF/HDPE composites modified with a 3 wt% KH550/SiO2-TiO2 exhibit the better mechanical properties, water resistance, and UV aging resistance compared to other contents. Flexural strength and modulus of KH550/SiO2-TiO2 modified BF/HDPE composites increased by 18.71 % and 17.92 %, tensile strength and modulus increased by 7.74 % and 21.92 %, respectively. The 480-hour water absorption and thickness swelling rate decreased by 18.68 % and 20.73 %, respectively, and the contact angle increased by 19.17°; better thermal stability and color stability was observed. The spray coating method was more effective in improving the properties of the modified BF/HDPE composites than the melt mixing method. Comprehensive analysis indicates that the mechanical properties, water resistance, thermal stability, and UV aging resistance of the BF/HDPE composites reinforced with 3 wt% KH550/SiO2-TiO2 prepared by the spray coating method are significantly enhanced.

Advanced Computational Insights Into the Optical, Electronic, and Thermoelectric Characteristics of Novel Rare‐Earth Ternary Chalcogenides

ABSTRACTRare‐earth ternary materials are distinguished by their tunable optoelectronic characteristics and high thermal stability. First principles computations examine the intricate interaction of novel rare‐earth‐based ternary chalcogenide's electronic, optical, and thermoelectric properties. The spin‐down channel of PrHSe exhibits a substantial energy gap resulting in half‐metallic behavior. The f orbitals of Pr and Er play an important role in forming bonds with Se and H atoms, contributing significantly to the valence band. The preponderance of Pr‐f and Er‐f orbitals near the top of the valence band indicate that electrons in these orbitals are the most energetic and participate in bonding interactions within these materials. The ErHSe has a greater absorption rate than PrHSe, and both materials behave isotropically in the xx and zz directions. The highest peaks of the reflection coefficient (50%–70%) in the 1.0–13.8 eV range suggested a significant level of UV reflectivity. The PrHSe has a higher intrinsic carrier concentration for conduction than ErHSe. At lower temperatures, carrier concentrations increase due to thermal activation processes, improving the Seebeck coefficient in these materials.

Wideband CPW fed four port MIMO antenna based microwave sensor for deep brain temperature measurement

This study presents a wideband CPW fed four-port multi-input multi-output (MIMO) antenna-based microwave sensor for measuring deep brain temperature inside human head. The range of frequency is from 5.45 to 8.56 GHz at the resonance frequency of 7.25 GHz. Coplanar Waveguide (CPW) fed approach on a low-cost FR4 substrate is used in designing the planar antenna. The presented antenna is compact, having overall dimensions of 40 × 40 × 1.6 mm3. In the operational frequency range, the obtained diversity performance for MIMO antenna shows Envelope Correlation Coefficient (ECC) < 0.05, Diversity Gain > 9.95, total active reflection coefficient (TARC ) < −13 dB and channel capacity loss (CCL) < 0.125 bits/S/Hz. For deep brain temperature measurements, the proposed sensor provides electric field of 3.92 V m−1 and specific absorption rate (SAR) value of 0.16 W kg−1 at the 9 mm distance inside the human head Phantom. The proposed sensor is capable of measuring 0.1 °C change in temperature at 10 W of input power for 60 s when all four ports are active.

Enhanced Water Resistance of TiO2-GO-SMS-Modified Soil Composite for Use as a Repair Material in Earthen Sites.

Most earthen sites are located in open environments eroded by wind and rain, resulting in spalling and cracking caused by shrinkage due to constant water absorption and loss. Together, these issues seriously affect the stability of such sites. Gypsum-lime-modified soil offers relatively strong mechanical properties but poor water resistance. If such soil becomes damp or immersed in water, its strength is significantly reduced, making it unviable for use as a material in the preparation of earthen sites. In this study, we achieved the composite addition of a certain amount of sodium methyl silicate (SMS), titanium dioxide (TiO2), and graphene oxide (GO) into gypsum-lime-modified soil and analyzed the microstructural evolution of the composite-modified soil using characterization methods such as XRD, SEM, and EDS. A comparative study was conducted on changes in the mechanical properties of the composite-modified soil and original soil before and after immersion using water erosion, unconfined compression (UCS), and unconsolidated undrained (UU) triaxial compression tests. These analyses revealed the micro-mechanisms for improving the waterproof performance of the composite-modified soil. The results showed that the addition of SMS, TiO2, and GO did not change the crystal structure or composition of the original soil. In addition, TiO2 and GO were evenly distributed between the modified soil particles, playing a positive role in filling and stabilizing the structure of the modified soil. After being immersed in water for one hour, the original soil experienced structural instability leading to collapse. While the water absorption rate of the composite-modified soil was only 0.84%, its unconfined compressive strength was 4.88 MPa (the strength retention rate before and after immersion was as high as 93.1%), and the shear strength was 614 kPa (the strength retention rate before and after immersion was as high as 96.7%).

Does GLP-1 cause post-bariatric hypoglycemia: ‘Computer says no’

Background and Objective:Patients who underwent Roux-en-Y Gastric Bypass surgery for treatment of obesity or diabetes can suffer from post-bariatric hypoglycemia (PBH). It has been assumed that PBH is caused by increased levels of the hormone GLP-1. In this research, we elucidate the role of GLP-1 in PBH with a physiology-based mathematical model. Methods:The Eindhoven Diabetes Simulator (EDES) model, simulating postprandial glucose homeostasis, was adapted to include the effect of GLP-1 on insulin secretion. Parameter sensitivity analysis was used to identify parameters that could cause PBH. Virtual patient models were created by defining sets of models parameters based on 63 participants from the HypoBaria study cohort, before and one year after bariatric surgery. Results:Simulations with the virtual patient models showed that glycemic excursions can be correctly simulated for the study population, despite heterogeneity in the glucose, insulin and GLP-1 data. Sensitivity analysis showed that GLP-1 stimulated insulin secretion alone was not able to cause PBH. Instead, analyses showed the increased transit speed of the ingested food resulted in quick and increased glucose absorption in the gut after surgery, which in turn induced postprandial glycemic dips. Furthermore, according to the model post-bariatric increased rate of glucose absorption in combination with different levels of insulin sensitivity can result in PBH. Conclusions:Our model findings implicate that if initial rapid improvement in insulin sensitivity after gastric bypass surgery is followed by a more gradual decrease in insulin sensitivity, this may result in the emergence of PBH after prolonged time (months to years after surgery).

EVALUATION OF PROPERTIES OF WOOD PLASTIC COMPOSITES MADE FROM SEVEN TYPES OF LIGNOCELLULOSIC FIBERS

This article aims to investigate the characteristics of wood plastic composites (WPC) prepared from polyethylene (PE) reinforced with lignocellulosic fibers derived from the xylem and bark of Masson pine, fir, cypress, as well as from Moso bamboo. The surface polarity and elemental composition of fibers were determined through contact angle measurements and X-ray photoelectron spectroscopy (XPS). The lignocellulosic fiber/PE composites were manufactured through hot-pressing technique, and their water absorption, mechanical properties, and mildew resistance were evaluated. The results revealed that the surface free energy of xylem fibers was higher than that of bark fibers among the three conifer species. XPS analysis showed that the O/C ratio of bark was consistently lower than that of xylem fiber. Among the three conifers, the Masson pine bark had the lowest O/C ratio (22.25%), while its xylem fibers had the highest ratio of 41.64%. WPC made with bark fibers had better water resistance. Additionally, the composites reinforced with xylem fibers showed superior static bending strength, impact strength, and mildew-resistant properties as compared to the composites reinforced with bark fibers. WPC made from bamboo fibers exhibited the best water resistance, with a water absorption rate and thickness swelling rate of 1.83% and 1.42%, respectively. They also had the highest static bending strength, elastic modulus, and impact strength, at 41.31 MPa, 3.82 GPa, and 10.24 kJ/m2, respectively. The WPC made from fir xylem fibers showed the most effective mildew resistance, with the smallest damage (0.50).

Enhancing Power and Thermal Gradient of Solar Photovoltaic Panels with Torched Fly-Ash Tiles for Greener Buildings

Solar photovoltaic (PV) panels that use polycrystalline silicon cells are a promising technique for producing renewable energy, although research on the cells’ efficiency and thermal control is still ongoing. This experimental research aims to investigate a novel way to improve power output and thermal performance by combining solar PV panels with burned fly-ash tiles. Made from burning industrial waste, torched fly ash has special qualities that make it useful for architectural applications. These qualities include better thermal insulation, strengthened structural integrity, and high energy efficiency. Our test setup shows that when solar PV panels are combined with torched fly-ash tiles, power generation rises by 7% and surface temperature decreases by 3% when compared to standard panels. The enhanced PV efficiency is ascribed to the outstanding thermal insulation properties of fly ash tiles and their capacity to control panel temperature. To ensure longevity and safety in building applications, the tiles employed in this study had a water absorption rate of 5.37%, flexural strength of 2.95 N/mm2, and slip resistance at 38 km/h. Furthermore, we find improved structural resilience and lower cooling costs when up to 30% of the sand in floor tiles is replaced with torched fly ash, which makes this method especially appropriate for sustainable buildings. Key performance indicators that show how effective these tiles are in maximizing energy use in buildings include thermal emissivity (0.874), solar reflectance (0.8), and solar absorption (0.256). While supporting more ecofriendly building techniques, this study highlights the advantages of utilizing burned fly ash in solar PV systems: enhanced power generation and thermal comfort. The main results open a greater potential for fly ash use in different building materials. The use of torched fly ash in building materials enhances thermal insulation and structural integrity while lowering cooling costs, making it an ideal choice for eco-friendly construction and highlighting the potential for further research into environmentally responsible, energy-efficient solutions.