Diameter Size Research Articles

Colloidal Protein–Silver Nanoparticle Metalloenzyme as Artificial Redox Biocatalyst

Efficient and sustainable catalytic processes are crucial for advancing green chemical manufacturing. Here, we describe the synthesis of novel silver artificial metalloenzymes in colloidal form in aqueous media and room temperature. The strategy is based on the in situ generation of silver nanoparticles by a genetically modified Geobacillus thermocatenulatus lipase (GTL) in the active site as an inducer and scaffold protein, producing an enzyme–Ag bioconjugate. Using a structural analysis of the formation of silver nanoparticles by XRD and UV spectra, we found the formation of Ag2O species with nanoparticles of around 11 nm average diameter size. Gel filtration chromatography demonstrated the presence of single protein molecules in the bioconjugates, although silver nanoparticles were initially formed by cysteine coordination in the active site but later were formed in other parts of the protein (five AgNPs per molecules, which is in concordance with the UV size). The enzyme structure was altered after nanoparticle formation and Ag-S interaction, which was observed in fluorescence analysis. This new enzyme showed reductive activity against p-nitrophenol to p-amino and a high conversion > 99% in the reduction of acetophenone to phenylethanol, although the enantioselective was quite moderate but higher in water that in the presence of co-solvents. Finally, oxidase-like activity was evaluated in the direct oxidation of phenylethanol to acetophenone in water, obtained at around a 23% yield of ketone after 60 h.

Highly Fluorescent Bio-Synthesized Carbon Quantum Dots for Latent Fingerprint Detection.

This study introduces an innovative approach to high-resolution latent fingerprint detection using carbon quantum dots (CQDs) biosynthesized from spent coffee grounds, enhanced with nitrogen doping. Conventional fingerprinting methods frequently use hazardous chemicals and are costly, highlighting the need for eco-friendly, affordable alternatives that preserve detection quality. The biosynthesized nitrogen-doped CQDs exhibit strong photoluminescence and high stability, offering a sustainable, effective alternative for fingerprint imaging. Using a one-step hydrothermal synthesis method, nitrogen-doped CQDs were developed, displaying intense cyan fluorescence under UV light at 365nm. The quantum yield was measured to be 19.73%. Characterization through UV-Visible and photoluminescence spectroscopy, FTIR, XRD and TEM confirmed the morphology, surface properties, optical properties and stability. The average particle size diameter was calculated to be around 8.71 ± 0.14nm. These CQDs were tested on various non-porous surfaces including marble, glass, aluminium, and metal where they provided detailed visualization of fingerprint ridge patterns, sweat pores, and minutiae with high fluorescence. Notably, the CQDs demonstrated excellent adherence and sustained fluorescence, maintaining photostability for up to 60 days under dark storage conditions at 2-8°C. This sustainable synthesis method thus produces nitrogen-doped CQDs with robust fluorescent properties, establishing a promising, eco-friendly solution for high-resolution latent fingerprint detection in forensic investigations.

Mycosynthesis of chitosan-selenium nanocomposite and its activity as an insecticide against the cotton leafworm Spodoptera littoralis.

The cotton leafworm, Spodoptra littoralis, causes great damage to cotton crops. A new, safer method than insecticide is necessary for its control. Selenium nanoparticles (SeNPs) are metalloid nanomaterial, with extensive biological activities. They have low toxicity and can be used safely in plant disease management. In this study, we successfully bio-fabricated selenium nanoparticles and chitosan-selenium nanocomposite (Ch-SeNPs) using a fungal cell-free filtrate of Penicillium griseofulvum. The biosynthesized nanomaterials were initially detected optically by the formation of a red color in the solution mixture and the appearance of a strong plasmon resonance peak at 240-300nm. The biosynthesized nanomaterials were fully characterized by UV-visible spectroscopy, transmission electron microscopy, dynamic light scattering, energy dispersive X-ray, inductively coupled plasma spectroscopy, and Fourier transform infrared. We tested the anti-insect activities of SeNPs, and Ch-SeNPs against larvae of S. littoralis compared to spore suspensions of P. griseofulvum. The results indicated that Ch-SeNPs followed by SeNPs gave a significantly higher mortality percentage than the spore suspension of the tested fungus. The highest production of all biosynthesized nanomaterials was detected after 7days at 40°C under alkaline conditions (pH 9). The average size diameter of SeNPs and Ch-SeNPs were 91.25 and 67.41nm with zeta potential - 8.05 and + 41mV, respectively. Both Ch-SeNPs and SeNPs gave high mortality rates and low values of LC50 and LC90 for both larvae and pupae. Ch-SeNPs showed stronger activity against S. littoralis than SeNPs and spore suspension at all experimental conditions. Cytotoxicity experiments indicated their safety against honeybee populations. The current study reveals the significant ultrastructure impact of SeNPs on larvae. These findings suggest that selenium nanoparticles and nanocomposite can be fabricated with a costless easy route using fungal filtrate, and they can be used safely in pest control systems that are safe for honeybee populations. It is the first report about the application of Ch-SeNPs as an anti-insect agent.

MACULAR HOLE SURGERY AND RETINAL TECTONICS: The Impact of Internal Limiting Membrane Peeling Size on Tangential Retinal Displacement.

To evaluate the tangential retinal displacement occurring following macular hole (MH) surgery and to assess the impact of the internal limiting membrane (ILM) peeling size on the extent of the retinal movement. This retrospective study included patients with full-thickness MH undergoing 25-gauge pars plana vitrectomy with ILM peeling. Patients received either a small ILM peeling with a size of two-disk diameters or a large peeling extended up to the vascular arcades. Near-infrared retinal imaging was performed with the Spectral is (Heidelberg Engineering, Carlsbad, Germany) before and 6 months after the surgery. The tangential retinal displacement was evaluated comparing the optical flow of near-infrared images with a custom digital image analysis algorithm. Forty-four eyes of 44 patients undergoing vitrectomy with small (n = 24) or large (n = 20) ILM peeling were included. An average overall displacement of 31.3 ± 22.8 µ m toward the optic disk was observed after the surgery. Large ILM peeling was associated with a significantly higher overall displacement ( P = 0.009), displacement in the central 4-mm circle ( P < 0.001), and displacement in outer 8-mm ring ( P = 0.001). Macular holes closure was achieved in 100% and 83.3% of patients in the large and small peeling group, respectively ( P = 0.055). Pars plana vitrectomy with ILM peeling for MH results in a tangential retinal displacement toward the optic disk. A larger extent of the ILM peeling leads to a greater tangential movement, possibly improving the MH closure rate.

Does Radioactive Iodine Treatment Affect Thyroid Size and Tracheal Diameter?

Background/Objectives: There exist three principal treatment modalities employed in the management of hyperthyroidism attributable to excessive hormone secretion by the thyroid gland: antithyroid pharmacotherapy, surgical intervention, and radioactive iodine (RAI) therapy. Surgical intervention is typically indicated for markedly enlarged thyroid glands that exert pressure on the trachea. The objective of this investigation was to ascertain the influence of RAI on thyroid volume and tracheal diameter. Methods: This study included 20 patients, six females and 14 males, who received 20 mCi radioactive iodine treatment for toxic nodular goiter at a tertiary university hospital between March 2019 and February 2020. Pre-treatment and six-month post-treatment neck MRI scans were conducted on the cohort. Thyroid and tracheal volumes were quantified using the Cavalieri method based on MRI sections, and comparisons were conducted pre-and post-treatment. Statistical analysis of the comparative values was performed using the dependent samples t-test. Results: A statistically significant reduction in thyroid volume was observed among the 20 patients, averaging a decrease of 36.06% following RAI treatment compared to baseline measurements (p < 0.001). Additionally, an average increase of 12.76% in tracheal volume was noted post-treatment in comparison to initial measurements, which was also statistically significant (p < 0.05). None of the patients exhibited respiratory distress in the immediate postoperative period. Conclusions: The findings indicate that RAI therapy leads to a reduction in thyroid size, accompanied by an increase in tracheal diameters subsequent to treatment. Given the potential complications and risks associated with surgical intervention, it may be prudent to consider large thyroids for RAI therapy as an alternative to surgery.

Bolanthus turcicus: a promising antidiabetic with in-vitro antioxidant, enzyme inhibitory and antiadipogenic activities.

It is crucial to investigate new anti-diabetic agents and therapeutic approaches targeting molecules in potential signaling pathways for the treatment of Type 2 diabetes mellitus (T2DM). The objective of the study was to investigate the total phenolic content, antioxidant capacity, α-glucosidase, and α-amylase inhibitory activities of Bolanthus turcicus (B. turcicus), as well as their cytotoxic, anti-adipogenic, anti-diabetic, apoptotic, and anti-migration potential on adipocytes. B. turcicus samples were extracted with methanol (MeOH), ethyl acetate (EA) and aqueous (Aq) solvents. The MeOH extract had the highest phenolic content (81.14mg GAE/g), followed by EA (74.93mg GAE/g) and Aq (51.09mg GAE/g). All extracts exhibited dose-dependent increases in α-glycosidase and α-amylase inhibitory activity. B. turcicus extracts showed cytotoxic effect on adipocytes with IC50 values of MeOH (141.0µg/mL) < Aq (155.3µg/mL) < EA (199.5µg/mL). Furthermore, B. turcicus extracts reduced lipid droplet formation and adipocyte diameter size. All extracts altered cell morphology to resemble fibroblasts. B. turcicus extracts exhibited anti-migratory effect delaying wound healing for up to 96h. The B. turcicus extracts showed a pro-apoptotic effects on adipocytes by increasing Caspase-3 enzyme activity and the population of DAPI-positive cell with apoptotic nuclear-morphology. B. turcicus extracts upregulated the expression of the Glut-4 gene at the mRNA, protein and intracellular level in adipocytes. In conclusion, our findings indicate that B. turcicus not only exhibits strong antioxidant properties and enzyme inhibitory activities but also exerts significant anti-adipogenic and pro-apoptotic effects in adipocytes, thereby providing a comprehensive mechanism through which it may contribute to the management of T2DM. These effects highlight the potential of B. turcicus as a therapeutic agent for improving glucose homeostasis and insulin sensitivity.

Starch distribution in sago palm (Metroxylon spp) trunk in East Luwu Regency

Sago is a starch-producing palm plant often found in marshland or peatland utilized by the community as food. East Luwu Regency is one of the areas where sago plants can be found. The purpose of this study was to determine sago starch distribution on the trunk of sago plants. The research methods used were interviews with farmers as key informants (qualitative) and direct observation of sago plants (quantitative). This study used 18 sago plant samples from two types of sago accessions, namely Uwwu accessions and Battang accessions, obtained from 3 sub-districts: Wotu, Kalaena, and Mangkutana. Sago morphological characteristics observed include plant height, trunk diameter, trunk circumference, pith weight, and dry starch weight. The circumference and diameter of the sago trunk varied among the lower, middle, and upper parts. The results showed that in Battang in Kalaena 3, the middle had a smaller diameter and trunk circumference compared to the lower and upper trunk but had the largest dry starch weight of 29.45 g, compared to the lower trunk (25.21 g) and the upper trunk (22.43 g). The environment is a factor that significantly influences the size of trunk circumference, trunk diameter, and starch content in sago plant trunk. Keywords: accession; Battang; pith; qualitative; starch; Uwwu

Evaluation of Moringa oleifera Incorporated With Zinc Oxide Nanoparticles/Poly(Vinyl) Alcohol Nanofibers as Antibacterial Material

ABSTRACTAntibacterial materials are increasingly significant, particularly for biomaterials and food packaging applications. Materials with good elasticity and antibacterial properties are crucial in this line of work. This study focused on the investigation of nanofiber properties in elasticity and antibacterial by combining Moringa oleifera (MO) zinc oxide nanoparticles (ZnO NPs) with polyvinyl alcohol (PVA) nanofiber. The PVA/MO/ZnO nanofiber is fabricated using the electrospinning method. The morphology of PVA/MO/ZnO nanofiber shows smooth and uniform fibers with 292 nm in diameter size. The EDX mapping also demonstrates the successful loading of ZnO NPs into fibers, and the tensile test gives modulus Young as 290 MPa, which corresponds to good elasticity or flexibility for biomedical applications. The antibacterial activity of PVA/MO/ZnO nanofiber mats against gram‐positive and gram‐negative microbial species shows a good inhibition zone of 6.84 mm for Escherichia coli bacteria. The hydrophilicity of the nanofibers also supported this antibacterial activity. These results show that PVA/MO/ZnO nanofiber is certainly a potential material that has good elasticity and antibacterial properties, which may be useful in biomaterial applications, food packaging, and coating material. It also suggested the simple preparation of an antibacterial material with good elasticity.

Aerosol Inhalation of Luteolin-7-O-Glucuronide Exerts Anti-Inflammatory Effects by Inhibiting NLRP3 Inflammasome Activation.

Background: Luteolin-7-O-glucuronide (L7Gn) is a flavonoid isolated from numerous traditional Chinese herbal medicines that exerts anti-inflammatory effects. Previous research has revealed that aerosol inhalation is the most straightforward way of administration for the delivery of respiratory agents. Thus far, the impact of aerosol inhalation of L7Gn on lung inflammation and the underlying mechanisms remain unknown. Methods: The real-time particle size for L7Gn aerosol inhalation was detected by the Spraytec spray droplet size measurement system, including transmission and size diameters. The acute lung injury (ALI) rat model was induced by aerosol inhalation of LPS to evaluate the protective effect of L7Gn. The inhibitory effect of NLRP3 inflammasome activation assays was conducted in LPS-induced MH-S cells. Elisa, Western blotting, and RT-PCR were utilized to investigate the expression of NLRP3 inflammasome-relevant proteins and genes. Results: In this study, we found that inhalation of L7Gn aerosol significantly reduced pulmonary injury by inhibiting inflammatory infiltration and enhancing lung function. Meanwhile, the NLR family pyrin domain containing 3 (NLRP3) inflammasome was activated dramatically, accompanied by upregulated expression of IL-1β and IL-18, both in the ALI rat model and in LPS-induced MH-S cells. Moreover, L7Gn was found to significantly downregulate the expression of NLRP3, ASC, caspase-1, and cleaved caspase-1, which are critical components of the NLRP3 inflammasome, as well as the expression of IL-1β and IL-18. Conclusions: Based on our findings, L7Gn could exert anti-inflammatory effects by inhibiting NLRP3 inflammasome activation, which may emerge as potential therapeutic agents for the treatment of ALI.

Electrodeposition of Nanostructured Metals on n-Silicon and Insights into Rhodium Deposition.

In this study, we investigate the electrodeposition of various metals on silicon. Mn, Co, Ni, Ru, Pd, Rh, and Pt were identified as promising candidates for controlled electrodeposition onto silicon. Electrochemical evaluations employing cyclic voltammetry, Scanning Electron Microscopy (SEM) associated with energy-dispersive X-Ray Spectroscopy (SEM-EDS), and X-Ray Photoelectron Spectroscopy (XPS) techniques confirmed the deposition of Pd, Rh, and Pt as nanoparticles. Multi-cycle charge-controlled depositions were subsequently performed to evaluate the possibility of achieving tunable electrodeposition of nanostructured rhodium on n-doped silicon. The procedure increased surface coverage from 9% to 84%, with the average particle size diameter ranging from 57 nm to 168 nm, and with an equivalent thickness of the deposits up to 43.9 nm, varying the number of charge-controlled deposition cycles. The electrodeposition of rhodium on silicon presents numerous opportunities across various scientific and technological domains, driving innovation and enhancing the performance of devices and materials used in catalysis, electronics, solar cells, fuel cells, and sensing.

Numerical optimization of cold gas dynamic spray process parameters through response surface methodology

ABSTRACT Copper-Zinc and its alloys are extensively used for the corrosion protection of the metal substrate surfaces like steel. Cold gas dynamic spraying (CGDS) is a material coating technique in which metal particles directly adhere to the substrate surface at a relatively low temperature. Numerical simulation (CFD) is a better alternative to understanding CGDS as compared to experimental data due to less expenditure and less energy consumption in CFD. Optimisation of CGDS can be done either by varying the process parameters or by improving the design of the de-Laval nozzle. In this study, the Response Surface Methodology (Central Composite Design) was used to optimise cold spray deposition efficiency by using a 2-D axisymmetric model by varying the process parameters such as carrier gas temperature, stand-off distance, and particle size. Various models were used to predict the critical velocity and erosion velocity. All the process parameters under consideration were found significant in analysing the model by ANOVA. Copper-Zinc Alloy (C93200) particle size is varied from 2.96 µm to 87.04 µm and carrier gas temperature is varied from 287.78K to 708.22K. With the increase in carrier gas temperature and particle size diameter, critical velocity decreases resulting in improved deposition efficiency.

Ameliorated delivery of Amphotericin B to Macrophages using Chondroitin Sulfate Surface-Modified Liposome Nanoparticles

Background The neglected tropical disease leishmaniasis has significant adverse effects from current treatments and limited therapeutic options are currently available. Objective The aim of this study was to develop a surface-modified nano-liposomal drug delivery system, anchored with chondroitin sulfate (CS), to effectively transport Amphotericin B (AmB) to macrophages. Methods Conventional liposome formulations (CL-F) and CS-coated surface-modified liposome formulations (CS-SML-F) were formulated by the thin film hydration method and characterized for particle size, polydispersity index (PDI), zeta potential and entrapment efficiency with long-term stability. In-vitro drug release using simulation medium, deformability index (DI) by using a polycarbonate membrane, and cell uptake studies among murine macrophages via flow cytometry were analyzed. Scanning and transmission electron microscopy were used to study the surface morphology and shape of the particles. Results Optimized conventional liposome CL-F6, CL-F9 and surface-modified liposomes CS-SML-F6 and CS-SML-F9 exhibited particle size diameters around 280 nm with a PDI of approximately 0.3 over six months of storage at 5 °C, maintaining stable surface charge (circa -30 mV). Sustained drug release peaked between 4 and 12 hours and surface morphology showed a uniform distribution of spherical liposome particles. Cell uptake measured by flow cytometry showed the highest rate of macrophage targeting by the CS-SML-Fs. Conclusion These findings have demonstrated that CS surface-modification has enhanced nanoparticle targeting to macrophage binding sites, particularly the cysteine-rich domain, potentially advancing macrophage-targeted drug delivery systems.

Semantic priming as modulator of saccade size and pupil diameter in glaucoma patients

Semantic priming as modulator of saccade size and pupil diameter in glaucoma patients

Characteristics of Ketapang Leaf Extract and PVA Nano Fibers Using the Electrospinning Method

The electrospinning method is a method of making nanofibers using the influence of an electric field to produce a jet of electrically charged polymer solution. In this experiment, polyvinyl alcohol (PVA) nanofibers and ketapang leaf extract with various viscosities were made using electrospinning equipment with a static collector. Scanning using an electron microscope (SEM) shows that the morphology of the nanofibers formed looks homogeneous, continuous, and without beads (beads free). The SEM results were analyzed using ImageJ software, which was then carried out using Origin software to determine the fiber diameter. Diameter size distribution with fiber diameter size distribution ranging from 2000 to 8000 nm.

Study of electric field distribution on plasma and plasma catalysis reactor for different electrode configurations and pellet sizes

In various non thermal plasma based applications, the dynamics of electric fields and charged particle interactions are crucial. In order to find an efficient plasma reactor, the effects of different electrode configurations for the plasma approach and pellet packaging &amp; optimal sizing for the plasma catalysis approach were studied for 6 different types of volume discharge and surface discharge reactor using COMSOL Multiphysics 6.0. The different electrode configurations viz. concentric cylindrical, square and helical as volume discharged reactors and floating &amp; 2 types of non-floating electrodes as surface discharge reactors are considered. The effect of different size (diameter 1/3/5 mm) of pellets were studied for helical and cylindrical plasma reactors for plasma catalysis. The simulated results were then experimentally verified and validated for production of ozone and the conversion or reduction of NOx from diesel exhaust.

Developing energy-efficient cool roof coatings using microencapsulated eutectic phase-change material and poly(methyl methacrylate-co-methacrylic acid) copolymer shell emulsion

ABSTRACT The rise in the construction of modern structures of buildings has increased the demand for energy sources to cool indoor and outdoor temperatures. Cool coating is a highly effective roofing technology for absorbing less heat and reflecting more sunlight than conventional coating. These coatings are made from a special type of material with high solar reflectance, allowing them to reflect more sunlight. The cool coating is applied over the building roofs, which gives an efficient way to cool the building inside passively and the surrounding environment. In this context, incorporating phase-change material (PCM) into cool coating enhances its capacity for regulating temperature by storing and releasing heat as required. Combining these two would improve the coating’s overall cooling capabilities, increasing its efficacy in maintaining a lower surface temperature and lowering the cooling energy consumption in buildings. There is a lack of research studies incorporating PCM into a cool roof coating. The present work fills this gap. In this study, we have developed an easy-to-maintain thermal storage cool roof coating using microencapsulated phase-change material (MPCM) latex and white cement. This coating integrates a cooling effect, making it ideal for building applications. Lauric acid (LA), palmitic acid (PA), and stearic acid (SA) eutectic PCM as core were microencapsulated with polymethyl methacrylate-co-methacrylic acid (PMMA-co-MAA) shell using oil-in-water emulsion polymerization. The microcapsule was prepared by altering the core-to-shell ratio. The microcapsules were characterized using various techniques such as thermogravimetric analysis (TGA), polarized optical microscopy (POM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). The melting temperature of LA-PA-SA eutectic PCM, MPCM 1, and MPCM 2 was 32.66°C, 31.47°C, and 32.73°C, respectively. The TGA analysis indicates that the prepared microcapsules have good thermal stability and degrade in two steps. Microcapsules’ average particle size diameter was observed in the 3–9 µm range. The cool roof coating was fabricated by partially replacing the acrylic copolymer latex with prepared MPCM 1 latex. This study evaluates the influence of MPCM 1 latex loading on the coating’s mechanical and thermal properties. The temperature changes from the building’s exterior to the interior have been recorded using thermal energy transfer analysis. General coating properties such as water resistance, stain resistance, alkali resistance, and gloss were investigated. DSC result shows that the thermal storage enthalpy of the coating has been improved from 17.85 J/g to 37.45 J/g by partially replacing MPCM 1 latex with acrylic copolymer from 50 to 70 wt.%. Coating with 70 wt.% MPCM 1 latex reduced the rise in the room’s temperature, showing it to be a promising candidate for utilizing thermal energy within building technologies.

Electrospun herbal extract‐loaded poly (3-hydroxy butyric acid-co-3-hydroxy valeric acid) nanofiber mats as potential wound dressing materials

Electrospun nanofiber mats have aroused intensive attraction for the design and development of innovative wound dressing materials, due to their high specific surface area and porosity, great air permeability, and excellent extracellular matrix (ECM) imitativeness. In this study, piezoelectric poly (3-hydroxy butyric acid-co-3-hydroxy valeric acid) (PHBV) was electrospun into nanofibers, and two different concentrations of herbal extract, Salvia miltiorrhiza Bunge-Radix Puerariae herbal compound (SRHC), were loaded into PHBV nanofibers during the electrospinning process for constructing novel wound dressings with multiple functions. All the generated PHBV mats loading with or without SRHC were observed to be constructed with randomly oriented nanofibers with the diameters ranging from 200nm to 900nm, and the mean fiber diameter and mean pore size presented an increased trend with the addition of SRHC. The average fiber diameter and mean pore size of PHBV nanofiber mat loading with 5% SRHC was determined to be 649.6±242.1nm and 2.1±0.4 μm, respectively. The addition of SRHC was found to significantly enhance the surface hydrophilicity of as-generated PHBV nanofiber mats that was changed to be hydrophilic from hydrophobic, while maintain the high mechanical properties and piezoelectric properties originated from the main polymer, i.e., PHBV. Importantly, all the nanofiber mats exhibited great biological properties, and the nanofiber mat with high SRHC content was demonstrated to significantly improve the anti-oxidant and anti-inflammatory performances, as well as promote the adhesion and proliferation of human dermal fibroblasts. The present studies demonstrated pronounced advantages of SRHC-PHBV-5% nanofiber mats to be used as potential wound dressing materials for the wound treatment.

Research on optimizing the scope of impact considering decomposition products in the event of a nitric acid spill chemical accident

As the size of the chemical industry increases, chemical accidents continue to occur as the handling volume of chemicals also increases. Currently, in the case of a chemical accident, the prediction of the scope of influence mainly analyzes the scope of the impact on a single substance in the accident and does not consider the scope of the decomposition and reaction products. Nitric acid, one of the many chemical accidents, produces nitrogen dioxide, which is harmful when decomposed. In this research, we at first assumed an outflow accident of nitric acid. After conducting our research using the Chemical Accident Response Information System (CARIS), we discovered that the impact range and breakdown of nitric acid were comparable to that of nitrogen dioxide. Furthermore, we were able to identify the potential ramifications associated with such occurrences. In this study, the impact scenarios were evaluated according to the worst-case scenario, the alternative scenario, the size of the leak hole diameter, atmospheric temperature, atmospheric wind speed, and atmospheric stability. The results showed that the end point concentration distance of nitrogen in ERPG-1, 2 and 3 was larger than nitric acid in most conditions, with differences of up to 5.45 times in the worst-case scenario, 5.96 times in the alternative scenario, up to 6.952 times in the leak hole diameter scenario, up to 10 times in the atmospheric temperature scenario, up to 13 times in the wind speed-specific scenario, and up to 4 times in the atmospheric stability scenario. In the event of a nitric acid spill chemical accident, the response agency should set up a boundary area at a greater distance in consideration of the impact of nitrogen dioxide when setting up a boundary area such as the Hot zone and the Warm zone. Nitric acid handling sites should install additional detectors for nitrogen dioxide, which is decomposition products, to monitor the diffusion of decomposition products into the atmosphere when installing detection alarm equipment in preparation for leakage accidents. It is believed that the government should continuously secure and study data on other decomposable chemicals besides nitric acid to provide material information and disaster prevention methods to chemical accident response agencies and communities for effective and early treatment of chemical accidents.

Alumina Crucibles from Free Dispersant Suspensions: A Useful Labware to form Advanced Powders for Radiation Dosimetry

Background: Powder technology provides conditions to control particle-particle interactions that drive the formation of final-component/material, which also includes the crystalline structure, microstructure and features. Alumina (Al2O3) is the most studied ceramic based material due to its useful properties, disposal, competitive price, and wide technological applicability. This work aims to produce alumina crucibles with controlled size and shape from free dispensant suspensions. These crucibles will be used as containers for the synthesis of new materials for radiation dosimetry. Methods: The Al2O3 powders were characterized by XRD, SEM, PCS, and EPR. The stability of alumina particles in aqueous solvent was evaluated by zeta potential determination as a function of pH. Alumina suspensions with 30 vol% were shaped by slip casting in plaster molds, followed by sintering at 1600oC for 2 h in an air atmosphere. Alumina based crucibles were characterized by SEM and XRD. Results: ɑ-Al2O3 powders exhibited a mean particle diameter size (d50) of 983nm. Besides, the stability of particles in aqueous solvent was achieved at a range of pH from 2.0-6.0, and from 8.5-11.0. EPR spectra revealed two resonance peaks P1 and P2, with g-values of 2.0004 and 2.0022, respectively. The as-sintered ɑ-alumina based crucibles presented uniform shape and controlled size with no apparent defects. In addition, the final microstructure driven by solid-state sintering revealed a dense surface and uniform distribution of grains. Conclusion: The ɑ-Al2O3 crucibles obtained by slip casting of free dispensant alumina suspensions, followed by sintering, exhibited mechanical strength, and controlled shape and size. These crucibles will be useful labwares for the synthesis of new materials for radiation dosimetry.

Inhibitory Effects of Iron Oxide Nanoparticles Biosynthesized by Prodigiosin Pigment Against Clinical Bacteria Isolates of Pseudomonas aeruginosa

The current study aimed to reveal the biosynthesis technique of Fe2O3 nanoparticles by using prodigiosin pigment production from Serratia marcescens. One hundred and twenty samples were obtained from burn and wound infections to isolate Pseudomonas aeruginosa. In addition, the optimum conditions for Fe2O3 nanoparticles biosynthesis were characterized via different methods, including ultraviolet-visible (UV-Vis), atomic force microscope (AFM), fourier transforms infrared (FT-IR) spectroscopy analysis, X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). In particular, spherical shape particles were observed utilizing FE-SEM technique. In addition, the analysis of AFM revealed Fe2O3 NPs with an average diameter size of 50.73 nm. The influences of varied concentrations of iron nanoparticles (6.25, 12.5, 25 , 50, 100and 200 mg/ml) on a bacterial isolate of Pseudomonas aeruginosa were examined. The maximum inhibition zone of P. aeruginosa was 24 mm at a concentration of 200 mg/ml of Fe2O3 NPs, whereas the minimum inhibition zone were 10 mm located at 25 mg/ml Fe2O3 NPs concentrations.