Absorption Rate Research Articles

Transcriptional response of primary hippocampal neurons following exposure to 3.0 GHz radiofrequency electromagnetic fields.

Exposure to radiofrequency (RF) electromagnetic fields (EMF) has been associated with the modulation of neuronal electrophysiology and synaptic plasticity. Given the potential of these changes to coincide with alterations in gene expression, this study investigated whether a transcriptional response would occur in neurons following exposure to RF-EMF, under both thermal and nonthermal conditions. Rat primary hippocampal neurons (PHNs) underwent either a single (one-time) or a multiple (3-times, once a day) exposures to RF-EMF (3.0 GHz, CW) at two different mean specific absorption rate (SAR) values of 0.57 W/kg or 5.91 W/kg, which induced a temperature change (ΔT °C) of approximately 0.3°C or 3.6°C, respectively. Alteration in transcription in the RF-EMF-exposed PHNs versus the sham counterparts was assessed at 0, 4, and 24 h postexposure via high-throughput RNA sequencing using Illumina HiSeq. 2000. A total of 20 differentially expressed genes (DEGs) exhibited significant upregulation due to RF-EMF exposure, observed only with the high SAR dose that induced a thermal rise. However, the expression of these DEGs was not significant at 24 h postexposure. Our findings confirmed a lack of nonthermal effects on gene expression under low RF-EMF exposure conditions as evaluated. Additionally, the results indicated a slight thermal effect of exposures at the dose nearing the standards threshold of 4 W/kg; however, the effect appeared to be transient. The study suggests that RF-EMF exposures at a level close to the standards threshold, despite inducing mild temperature elevations (i.e., 3-5°C above normal), would not trigger biologically critical cellular changes.

Non-sintered ceramsite from alkali-activated gasification slag for adsorption through the regulation of physical properties and pore structure

With the development of the coal gasification industry, the comprehensive utilization of coal gasification fine slag (CGFS) has become increasingly important. This study explored the potential of producing non-sintered ceramsite by combining CGFS with blast furnace slag (BFS). The impacts of the alkali activator modulus, dosage, and BFS-CGFS ratio on the ceramsite's cylinder compressive strength, bulk density, apparent density, water adsorption ratio, hydration products, microstructure, and adsorption capacity were investigated. Moreover, the leaching behavior of heavy metals in acidic environments and the production costs were evaluated. The results indicated that the modulus and dosage of the alkali activator, along with the BFS-CGFS ratio, significantly affected the properties of the ceramsite. The cylinder compressive strength, bulk density, and apparent density of the ceramsite increased with the increase in the alkali activator dosage and modulus, but decreased as the BFS-CGFS ratio decreased. The water absorption rate behaved oppositely. With increasing alkali activator modulus and dosage, the ceramsite's adsorption capacity for iodine, CODCr, and methylene blue first increased and then decreased, peaking at a modulus of 1.4 and a dosage of 12%, respectively. A reduced BFS-CGFS ratio increased the adsorption capacity of the ceramsite for iodine and CODCr. Considering both mechanical and adsorption properties, the optimal composition for the ceramsite was found to be an alkali activator modulus of 1.4, a dosage of 12%, and a CGFS content of 70%. With this ratio, the use of ceramsite would not result in secondary environmental pollution. This study not only provided a new approach to enhance the utilization of CGFS but also avoided the use of calcination processes in producing ceramsite, demonstrating its potential in reducing environmental impact.

Iron wool as a heating agent for magnetic catalysis: Experiments and analysis of heating properties under a high-frequency magnetic field

Magnetically induced heterogeneous catalysis has been attracting attention due to its high energy efficiency and flexibility for dynamic reactor control. Iron wool is a commercial, low-cost, and versatile heating agent, which has been used in several magnetic catalysis studies, but its heating properties have never been investigated. Here, the properties of three types of Fe wool were studied using optical and electronic microscopy, x-ray diffraction, and measurements of both heating power and high-frequency hysteresis loops. The effects of strand width, packing, and magnetic field amplitude and frequency were studied. A maximum specific absorption rate (SAR) around 700 W/g under a rms field of 47.4 mT at 93 kHz was measured for the larger width Fe wool. High-frequency hysteresis loops were used to quantify the contribution of hysteresis losses and eddy currents to total heating. Eddy currents contribute 65%–90% to the global heating depending on the strand width. Coating the wool with SiO2 and Ni has negative effects on the SAR but none on hysteresis losses. It is interpreted as originating from the cut-off of inter-wire eddy currents due to the insulating (SiO2, oxidized Ni) nature of the coating. Last, it was found that adding more Fe wool in a given volume mostly decreases the SAR. This effect could be not only due to the absorption and/or screening of the field by surface strands but also due to magnetic interactions. The results described in this work give insights into the magnetic heating of microscale magnetic materials and optimize their use for heterogeneous catalysis.

Impacts of shellfish and macroalgae mariculture on the seawater carbonate system and air-sea [formula omitted] flux in Haizhou Bay, China

China is the largest mariculture country, and shellfish and algae output ranks first, showing high carbon sink capacity. In recent years, the single cultivation of macroalgae (Pyropia yezoensis) has been changed to macroalgae-shellfish mariculture in Haizhou Bay to increase the yield of P. yezoensis and improve the water environment quality. In this study, four surveys were carried out in July 2022 during the monoculture period of oyster (Magallana gigas), as well as at different stages of P. yezoensis culture (head-crop period, November 2022, peak growing season, January 2023, and end of harvesting, March 2023) in the mariculture and the surrounding waters of Haizhou Bay. The effects of different stages of culture on the seawater environment and seasonal and spatial variations in the carbonate system were analyzed, and the carbon sink capacity was preliminarily estimated. The results showed that in summer, the calcification of M. gigas and the primary production process of phytoplankton effectively reduced the dissolved inorganic carbon (DIC) level in the culture area. The culture area acts as a CO2 sink, with an average air-sea CO2 flux of −4.5 mmol m−2 d−1. During the polyculture period, the P. yezoensis culture activities maintained the stability of the seawater carbonate system, and the culture area shows strong CO2 sinks, with the average air-sea CO2 flux of −24.10 mmol m−2 d−1, -37.68 mmol m−2 d−1, and -38.99 mmol m−2 d−1, respectively. The absorption of CO2 by large-scale cultured P. yezoensis through the "biological pump" effect is the main factor affecting the CO2 exchange process at the air-sea interface, and the absorption rate of CO2 by P. yezoensis at the mature stage is higher than that at the growth stage before harvesting. The study revealed that macroalgae-shellfish mariculture could promote mutual growth, alleviate environmental pressure, and enhance the carbon sink of the culture area. The relationship between mariculture and the carbon cycle of a mariculture ecosystem is very complicated, and its biochemical process should be given great attention for further study.

Research on mercury re-release model in wet flue gas desulfurization (WFGD) in coal-fired power plants

Mercury (Hg), a toxic heavy metal, has triggered regulations for emission control from coal-fired power plants. It has been found that mercury re-release occurs in WFGD slurry, which is affected by WFGD process parameters. The coal co-combustion with bromide technology proves to be an efficient approach for enhancing mercury removal ratio but the accumulation of introduced bromine in WFGD slurry would impact the re-emission behavior of mercury significantly. Model study is efficient method to reveal the physicochemical processes in WFGD systems. However, previous model studies were carried out under Hg2+ contained simulated slurry systems without consideration of Hg2+ transformation process from gas to liquid phase, and co-combustion with bromide technology was not considered. Here, a model which encompasses droplets motion sub-model, gas–liquid heat transfer sub-model, gas–liquid mass transfer sub-model and the mercury re-release kinetic sub-model is developed and validated against experimental data. The effects of bromine concentration, slurry temperature, pH value and S(IV) concentration were investigated. It was found that introduced bromine has significant inhibitory effects on the re-release of mercury. When the slurry temperature is higher, the absorption rate of Hg2+ is lower and more Hg0 is released. Moreover, the increase in the slurry pH value and S(IV) concentration has certain inhibitory effects on the re-release of Hg0 in WFGD. Above all, the developed model has high prediction accuracy for the absorption of Hg2+ and the re-release of Hg0 in WFGD which is expected to be beneficial for guiding the operation of WFGD systems.

A microfluidic in vitro method predicting the fate of peptide drugs after subcutaneous administration

For many biopharmaceuticals, subcutaneous (sc) administration is the only viable route. However, there is no in vitro method available accurately predicting the absorption profiles of subcutaneously injected pharmaceuticals. In this work, we show that a recently developed microfluidics method for interaction studies (MIS) has the potential to be useful in this respect. The method utilises the responsiveness of polyelectrolyte microgel networks to oppositely charged molecules as a means to monitor the interaction between peptides and hyaluronic acid (HA), a major constituent of the subcutaneous extracellular matrix. We use the method to determine parameters describing the strength of interaction between peptide and HA as well as the peptide’s aggregation tendency and transport properties in HA networks. The results from MIS studies of the peptide drugs exenatide, pramlintide, vancomycin, polymyxin B, lanreotide, MEDI7219 and AZD2820 are compared with results from measurements with the commercially available SCISSOR system and in vivo absorption and bioavailability data from the literature. We show that both MIS and SCISSOR reveal differences in the peptides’ diffusivity and tendency to aggregate in the presence of HA. We show that MIS is particularly good at discriminating between peptides forming aggregates stabilised by non-electrostatic forces in the presence of HA, and peptides forming complexes stabilised by electrostatic interactions with HA. The method provides two parameters that can be used to quantify the peptides’ aggregation tendency, the one describing the peptide packing density in complexes with HA and the other the apparent diffusivity upon release in a medium of physiological ionic strength and pH. The order of the peptides when ranked by increasing binding strength at pH 7.4 determined with MIS is shown to be in agreement with the order when ranked by the apparent 1st order absorption rate constant (ka) after sc administration in humans: lanreotide (Autogel) < exenatide (IRF) < AZD2820 < pramlintide < lanreotide (IRF) (IRF: Immediate release formulation). A correlation is found between the 1st order release rate constant determined with SCISSOR and ka for lanreotide (Autogel), exenatide and AZD2820. A mechanism relating the magnitude of ka to the peptides’ charge is proposed.

Achieving uniform distribution of nanoparticles in oxide dispersion strengthened (ODS) SS316L through laser powder bed fusion (L-PBF)

Oxide dispersion strengthened (ODS) SS316L is a promising candidate for the nuclear industry for its enhanced irradiation resistance and high temperature strength. Additionally, additive manufacturing enables the design flexibility of components. Achieving a uniform distribution of oxides in ODS SS316L is one of the remaining challenges in additive manufacturing. In this paper, we investigated the effects of printing parameters on the microstructure and mechanical properties of ODS SS316L (SS316L + 0.5 wt% Y2O3) through laser powder bed fusion (L-PBF) additive manufacturing. The results showed that plate-like Y-Si-rich oxides (∼50 μm) were observed along the molten pool boundary in the ODS SS316L printed with nominal parameters (48.5 J/mm3) for pure SS 316L, resulting from inadequate heat input in molten pool due to the reduced laser absorption rate of powder feedstock. Through higher volumetric energy density (76.2 J/mm3) and remelting, a bimodal distribution of oxides, including nanoparticles and fine spherical oxide (∼2.5 μm), was achieved. Consequently, this contributed to increased ultimate tensile strength (UTS) and strain of ODS SS316L from 685.2.6 ± 31.4 MPa and 27.8 ± 6.2 % to 706.6 ± 36.2 MPa and 33.0 ± 6.1 %, respectively. The exploration of parameters optimization provides valuable insights into the additive manufacturing of ODS alloys with uniformly distributed nanoparticles.

Effects of Simvastatin-Loaded Nanomicelles on the Early Preservation of Tooth Extraction Sites.

The present study intended to evaluate the effect of simvastatin-loaded nanomicelles (SVNs) on promoting new bone formation and reducing alveolar ridge resorption at the tooth extraction sites at the early healing of the extraction sockets. SVNs were synthesized using a dialysis method. The rabbit tooth extraction model was established, SVNs and simvastatin (SV) were loaded on gelatin sponge and inserted into the extraction socket. CBCT scans were performed at 0, 2, and 4weeks postoperatively to evaluate bone formation and alveolar ridge absorption in the extraction sockets. And all the animals were sacrificed and the mandibles were harvested. And HE staining and Masson staining were used for histological evaluation of the bone formation in the extraction sockets. Radiographic evaluation showed that compared with the blank control group, at 2 and 4weeks after extraction, SVNs increased the new bone density in the extraction sockets by 75.7% and 96.5%, and reduced the absorption rate of alveolar ridge length at the extraction sites by 60.8% and 49.1%, respectively. Histological evaluation showed that SVNs significantly improved the maturation of new bone tissue in the extraction sockets. SVNs can significantly accelerate healing and effectively reduce the absorption of alveolar ridge at the extraction sites in the early stage of tooth extraction socket healing.

Research on CO2 capture performance and reaction mechanism using a novel low energy consumption and high cyclic performance absorbent for onboard application

High desorption energy consumption and low cyclic loading are critical issues limiting the application of onboard carbon capture (OCC) systems. In this study, a tetraethylenepentamine (TEPA) and 2–amino–2–methyl–1–propanol (AMP) mixed amine solvent with low desorption energy consumption and high CO2 cyclic loading, suitable for the operational environment of OCC systems, has been proposed. Detailed research was conducted on the capture performance and mechanism of the TEPA + AMP mixed amine solvent. The 0.25M TEPA+0.75M AMP mixed amine solvent exhibited the best performance, with an 86.5% increase in CO2 loading, a 214% increase in single–cycle CO2 loading, a 236% increase in CO2 loading after four cycles compared to monoethanolamine (MEA), and a 20.76% reduction in desorption energy consumption. In addition, to address the challenge of applying polyamine mixed solutions in the simulation studies of OCC systems, the capture mechanism was analyzed using density functional theory (DFT) calculations and nuclear magnetic resonance (NMR) characterization. The results indicated that increasing AMP promoted HCO3– formation in the TEPA + AMP mixed amine solvent. Since HCO3– decomposed more easily than carbamate, it reduced desorption energy consumption. However, an excess of AMP inhibited the absorption rate of TEPA, affecting the absorption capacity. Increasing the concentration of TEPA enhanced the amine concentration in the absorbent and improved the absorption performance. Nevertheless, excessive TEPA caused AMP to participate only in deprotonation reactions, which was not conducive to reducing desorption energy consumption.

Near-field metasurface sensor for an early-stage breast cancer detection

In this paper, a novel and highly sensitive metasurface sensor for microwave breast tumor detection is proposed. The proposed sensor array comprises 8 × 8 small-size sensor elements that are capable of reacting to changes in both electric and magnetic fields. This allows the sensor to detect even minor variations in the surrounding medium, resulting in improved sensitivity. Additionally, designing a sensor array improves sensitivity by covering all areas of the breast tissues with multiple small sensor elements. Numerical studies have been conducted to assess the sensor sensitivity using realistic healthy and non-healthy breast models with diagnosed tumors placed at different locations within healthy breast models in the CST simulation environment at varying stand-off distances. An experiment was conducted to validate the sensor’s concept. It involved testing a metasurface sensor with phantoms resembling both healthy female breast tissues and those with a 10 mm tumor. The results from simulations and experiments demonstrate that the metasurface sensor is capable of detecting breast tumors at different distances. For safety compliance, specific absorption rate (SAR) values were obtained through both simulation and experimentation. The simulated SAR values were calculated to be 0.357 W/kg and 0.216 W/kg at 1 g and 10 g, respectively, using 17 dBm for safety. The measured SAR values were 0.101 W/kg and 0.1 W/kg at 1 g and 10 g, respectively.

Effects of aggregates and fibers on the strength and permeability of concrete exposed to low vacuum environment

The performance and regulation of concrete in low vacuum environments are receiving increasing attention. This study investigates the effects of aggregates and fibers on the strength and permeability of concrete in a low vacuum environment, using varying gradients of sand ratios (37.5 %, 40 %, and 42 %) and aggregate-to-binder ratios (3.27, 3.92, and 4.14). Three types of non-metallic fibers are utilized: polyethylene (PE), polyvinyl alcohol (PVA), and glass fibers. Evaluations focus on concrete strength, mass loss, gas permeability, capillary water absorption, and porosity. Results indicate that higher sand and aggregate-to-binder ratios enhance both flexural and compressive strength. Fiber incorporation improves flexural and compressive toughness, with PE fibers showing the most significant toughening effect. The low vacuum environment increases the strength of the concrete but reduces its axial compression toughness ratio and increases brittleness, while fiber incorporation helps improve the compression toughness of the concrete. Higher sand and aggregate-to-binder ratios reduce mass loss and accelerate drying equilibrium, while fibers increase mass loss and prolong drying equilibrium, with PVA fibers causing greater mass loss. The pattern of concrete mass loss can be explained by the tortuosity of the moisture diffusion path. Additionally, low vacuum significantly increases the gas permeability of concrete. Enhancing the sand and aggregate-to-binder ratios reduces permeability both before and after low vacuum treatment. Although fibers increase the gas permeability, they help mitigate this increase under low vacuum condition. Capillary water absorption tests reveal that concrete under low vacuum condition has a significantly higher water absorption rate compared to air-drying condition. Increasing sand and aggregate-to-binder ratios reduces water absorption and capillary water content, whereas fibers have the opposite effect. Porosity tests show that moisture migration in a low vacuum environment is mainly related to permeable porosity, while total porosity is more closely related to compressive strength.

Research on a broad-band X-band high power relativistic klystron amplifier

This paper introduces a high-power broadband X-band klystron amplifier that achieves an output power of 157 MW and a 3 dB operating bandwidth of 6.7%. The amplifier employs an explosive emission diode with high impedance, which balances the requirements of high power and broadband. The multi-gap input and output cavities are designed to operate at two different longitudinal modes within the operating frequency band, resulting in a flat absorption rate and output efficiency. Moreover, an eight-stage stagger-tuned bunching section is implemented to achieve a uniform fundamental harmonic current modulation depth across the frequency band. Simulation results indicate that when the diode voltage is 550 kV and the beam current is 550 A, the amplifier can achieve a maximum power of 157 MW with an efficiency of 51.9% at the central frequency of 9.8 GHz. Furthermore, within the 3 dB operating bandwidth of 6.7% (670 MHz), the power output remains higher than 80 MW. This novel klystron amplifier structure exhibits exceptional performance in terms of bandwidth, power, and efficiency, thus validating the effectiveness of the design in enhancing bandwidth and providing a solid foundation for the broadband design of high-power microwave sources.

Effect of wound dressing porosity and exudate viscosity on the exudate absorption: In vitro and in silico tests with 3D printed hydrogels

Exudate absorption is a key parameter for proper wound dressing performance. Unlike standardized tests that consider exudate viscosity close to that of water, patients' exudates vary greatly in composition and, therefore, viscosity. This work aimed to investigate the effects of exudate viscosity and pore size of hydrogel-like dressings on the exudate absorption rate to establish rational criteria for the design of dressings that can meet the personalized needs of wound treatment. Computer-aided design (CAD) was used for Digital Light Processing (DLP) 3D printing of hydrogels with 0%, 30% and 60% porosity. The hydrogels were characterized in detail, and the absorption of two simulated exudate fluids (SEFs) was video-recorded. The same CAD files were used to develop in silico models to simulate exudate uptake rate. Both in vitro data and in silico modeling revealed that low-viscosity SEF penetrates faster through relatively small hydrogel pores (approx. 400 μm) compared to larger pores (approx. 1100 μm) due to capillary forces. However, in vitro vertical uptake took longer than when simulated using CAD design due to lateral fluid absorption through the pore walls in the hydrogel bulk. Distortions of hydrogel channels (micro-CT images) and lateral fluid absorption should be both considered for in silico simulation of SEF penetration. Overall, the results evidenced that porous hydrogel dressings allow rapid penetration (within a few seconds) and hosting of exudates, especially for pore size <1 mm. This information may be useful for design criteria of wound dressings with adequate fluid handling and drug release rate.

Indoor air quality improvement using developed polymeric membrane filter

Abstract Carbon dioxide (CO2) levels must be controlled to protect the environment and human health. Previous studies focused on improving indoor air quality (IAQ) by reducing these negative impacts with electrical equipment such as mechanical ventilators and air purifiers; however, passive techniques were lacking. This work develops a prototype membrane filters to improve IAQ by capturing and separating indoor CO2 levels. These filters use polyvinyl alcohol (PVA) membranes and activated carbon (AC) as innovative and effective passive materials at four concentrations. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-Ray diffraction (XRD) were employed to characterize the materials. The effectiveness of CO2 absorption across the four filter types was then assessed through tests conducted in a controlled environment. Subsequently, site monitoring was undertaken to evaluate the most effective filter. The absorption rates of CO2 levels indoors of the developed filters are 17.5%, 8.1%, 4.5%, and 3.4%, respectively, for four filters. The most efficient filter increased absorption efficiency by 47.8% in an unoccupied space and 35.5% in an occupied one. This passive material can be applied in various indoor spaces, including office buildings, residential buildings, and educational facilities, due to its benefits in saving energy and enhancing indoor environmental quality.

Improving The Geotechnical Properties of Cohesive Soils Using Portland Cement and Some Composite Polymers in A Selected Location in The City of Tanumah / Basrah Governorate – Southern Iraq

Background: The purpose of this research is to ascertain how adding Portland cement and composite polymers, as well as the ideal ratios between them, will affect cohesive soils' geotechnical characteristics. Materials and Methods: A composite polymer was created by combining three polymers—isocyanide, unsaturated polyester, polyvinyl acetate, and thinner—as well as a solvent. Portland cement was added to the soil at a rate of 5% of the sample weight. Different percentages of the weight of the cement supplied to the sample—5, 10, 15, 20, and 25%—were utilized as the composite polymer. Several geotechnical tests were carried out, including compaction, unconfined compressive strength, California bearing ratio, absorption, and Atterberg's limits, to ascertain the ideal amount of polymer for the aim of improvement. Results: The findings show that adding cement at a rate of 5% by weight of the sample and a polymeric mixture at a rate of 15% by weight of cement can improve the cohesive soil's engineering properties. It was found that the maximum dry density, unconfined compressive strength, and California bearing ratio had increased while the values of the optimal moisture content, absorption rate, liquid limit values, and plasticity index had decreased. Conclusion: The composite polymer used in soil improvement not only improves the geotechnical properties and resistance of the soil, but it also efficiently enhances and activates the effectiveness of cement. When 15% of the sample's weight of cement was composed of composite polymers, the soil's engineering attributes increased the most.

Mechanistic Characteristics of HRS-WC Mixture Using Tabas Stone Waste Coated With Plastic Waste As Aggregate

Utilization of tabas stone waste and polypropylene (PP) plastic waste has not been carried out massively and optimally because it lacks economic value. The Tabas stone waste can be used as an aggregate for pavement. The porous characteristic of tabas stone results in a high rate of absorption and abrasion, so modifications are made by coating the aggregate with an PP plastic. The aim of this experiment was to determine the characteristics of the HRS-WC mixture with the aggregate of tabas stone coated with plastic. The initial step of this research was testing the tabas stone aggregates, bitumen material, and PP plastic according to the SNI procedure, the next step was Marshall test to find the Optimum Bitumen Content (OBC), the OBC value was obtained by 10%. Coating the aggregate with shredded plastic measuring ± 1 cm2 was done on coarse aggregate only using the dry method with the proportions of plastic are 5% and 10% of the total weight of coarse aggregate. The characteristics of the aggregate coated with plastic decrease in the value of absorption and abrasion, but only 10% of the plastic content met the specifications with a value of 2.5% and 19.63%. The Marshall testing on the HRS-WC mixture with plastic-coated aggregates was done at variations in bitumen content of 8.5%; 9%; 9.5%. The mixture at 5% plastic content only 9.5% bitumen content met the specifications, namely: stability 1352.72 kg, flow 3.39 mm, MQ 402.23 kg/mm, VIM 5.75%, VMA 18.62% , and VFB 69.16%. When at 10% plastic content, only 9% and 9.5% bitumen content met the specifications, namely the stability of 1370.06 kg; 1456.21 kg, flow 3.81 mm; 3.98 mm, MQ 365.31 kg/mm; 370.06 kg/mm, VIM 5.77%; 4.89%, VMA 18.07%; 18; 15%, and VFB 68.05%; 73.04%. Asphalt mixture of 9% bitumen content, 10% plastic content has more ITSM value compared to 5% plastic content. This is due to the plastic content in the mixture of 10% plastic content which causes the mixture to be stiffness. Asphalt mixture with a plastic content of 5%, with an bitumen content of 9.5% faster than the mixture with an bitumen content of 8.5% and 9% in the ITFT test. Asphalt mixture with a plastic content of 5%, with a variation of bitumen of 8.5% experienced a decrease in the dynamic creep strain value until the bitumen content was 9.5%. A mixture with a plastic content of 5% aggregate coating is recommended for HRS WC that uses tabas stone.

Microwave Frequency Analysis of Dielectric Properties in Biological Tissues: Insights into Dielectric Constant, Conductivity, and Resistivity at 9.4 GHz

This study investigates the dielectric properties of various biological tissues at microwave frequencies, specifically focusing on their dielectric constant, conductivity, resistivity, and loss tangent. Using methods such as Von Hippel’s and Yadav Gandhi’s techniques, the dielectric characteristics of heart, liver, brain, and muscle of chicken tissues were analysed at 9.4 GHz. It is found that tissues with higher water content exhibit greater dielectric constants and conductivities, while those with higher solid content, like liver, display higher resistivity. It has also been observed that tissues with lower dielectric constants and conductivities are those with greater absorption indices, which are typically associated with increased energy dissipation as heat. An increasing amount of energy dissipation may result from tissues with higher absorption rates being less effective at transferring microwave energy, as suggested by this inverse connection, which also emphasizes the complexity of electromagnetic wave interaction within tissues. This work provides critical insights into the interaction of electromagnetic waves with biological tissues, which is essential for applications in medical diagnostics, therapeutic technologies, and electromagnetic exposure safety standards.

From Sea to Lab: Angiotensin I-Converting Enzyme Inhibition by Marine Peptides-Mechanisms and Applications.

To reveal potent ACE inhibitors, researchers screen various bioactive peptides from several sources, and more attention has been given to aquatic sources. This review summarizes the recent research achievements on marine peptides with ACE-inhibitory action and application. Marine peptides are considered excellent bioactives due to their large structural diversity and unusual bioactivities. The mechanisms by which these marine peptides inhibit ACE include competitive binding to ACEs' active site, interfering with ACE conformational changes, and avoiding the identification of substrates. The unique 3D attributes of marine peptides confer inhibition advantages toward ACE activity. Because IC50 values of marine peptides' interaction with ACE are low, structure-based research assumes that the interaction between ACE and peptides increased the therapeutic application. Numerous studies on marine peptides focused on the sustainable extraction of ACE-inhibitory peptides produced from several fish, mollusks, algae, and sponges. Meanwhile, their potential applications and medical benefits are worth investigating and considering. Due to these peptides exhibiting antioxidant, antihypertensive, and even antimicrobial properties simultaneously, their therapeutic potential for cardiovascular disease and other illnesses only increases. In addition, as marine peptides show better pharmacological benefits, they have increased absorption rates and low toxicity and could perhaps be modified for better stability and bioefficacy. Biotechnological advances in peptide synthesis and formulation have greatly facilitated the generation of peptide-based ACE inhibitors from marine sources, which subsequently offer new treatment models. This article gives a complete assessment of the present state of knowledge about marine organism peptides as ACE inhibitors. In addition, it emphasizes the relevance of additional investigation into their mechanisms of action, the optimization of manufacturing processes, and assessment in in vivo, preclinical, and clinical settings, underlining the urgency and value of this study. Using marine peptides for ACE inhibition not only broadens the repertory of bioactive compounds but also shows promise for tackling the global health burden caused by cardiovascular diseases.

Interaction between Electromagnetic (EM) wave and human head: Normal adult and elderly heads

In recent years, there has been an increasing public concern about the health implications of electromagnetic (EM) wave exposure with the use of mobile telephones. In this paper, we have evaluated the EM absorption in the human head at GSM 900 MHz (Global System for Mobile telecommunications) and DCS 1800 MHz (Digital Cellular System) radiation. Two models for human head were considered. The first model was normal adult head whereas the second model was normal elderly head. First, a stratified structure of the human head is modeled. Next, a two-dimensional (2-D) cylindrical head model based on finite-difference time-domain (FDTD) method is investigated. Our previous described 2-D FDTD code based on LabVIEW has been utilized. Much attention has been paid to the induced specific absorption rate (SAR) in elderly human head.

Inovasi Paving Block Bentuk Ikan Pari

The weak interlock system in paving blocks can cause discomfort for drivers when passing over them. The more frequently traversed by vehicles, paving blocks with poor interlock systems will experience displacement. The compressive strength of paving blocks also affects their quality, thus supporting the performance of the paving block interlock system. This research aims to produce paving block products with a better interlocking system. The method used in this research is experimental and conducted in a laboratory setting. The results of the compressive strength test on stingray-shaped paving blocks, conducted at 14 days and converted to 28 days, showed superior compressive strength with an average of 24.04 MPa compared to conventional square and hexagonal paving blocks tested at 28 days, each with an average compressive strength of 20.07 MPa and 22.25 MPa, respectively. The water absorption test of the stingray-shaped paving blocks conducted at 7 and 14 days showed average water absorption rates of 5.67% and 4.31%, respectively, meeting the quality requirements of Grade B according to SNI -03-0691-1996, which requires less than 6%. Interlock system testing of the stingray-shaped paving blocks indicated superiority with an average displacement of 5.514 mm compared to conventional square and hexagonal paving blocks, each with an average displacement of 11.802 mm and 9.744 mm, respectively. The cost calculation for stingray-shaped paving blocks amounted to Rp. 2263.22 per paving block, 24,559% more economical than the total cost for conventional hexagonal paving blocks, which amounted to Rp. 3000.00.