Metal Profiles Research Articles

The interplay between feedback, accretion, transport, and winds in setting gas-phase metal distribution in galaxies

ABSTRACT The recent decade has seen an exponential growth in spatially resolved metallicity measurements in the interstellar medium (ISM) of galaxies. To first order, these measurements are characterized by the slope of the radial metallicity profile, known as the metallicity gradient. In this work, we model the relative role of star formation feedback, gas transport, cosmic gas accretion, and galactic winds in driving radial metallicity profiles and setting the mass–metallicity gradient relation (MZGR). We include a comprehensive treatment of these processes by including them as sources that supply mass, metals, and energy to marginally unstable galactic discs in pressure and energy balance. We show that both feedback and accretion that can drive turbulence and enhance metal-mixing via diffusion are crucial to reproduce the observed MZGR in local galaxies. Metal transport also contributes to setting metallicity profiles, but it is sensitive to the strength of radial gas flows in galaxies. While the mass loading of galactic winds is important to reproduce the mass–metallicity relation (MZR), we find that metal mass loading is more important to reproducing the MZGR. Specifically, our model predicts preferential metal enrichment of galactic winds in low-mass galaxies. This conclusion is robust against our adopted scaling of the wind mass-loading factor, uncertainties in measured wind metallicities, and systematics due to metallicity calibrations. Overall, we find that at z ∼ 0, galactic winds and metal transport are more important in setting metallicity gradients in low-mass galaxies whereas star formation feedback and gas accretion dominate setting metallicity gradients in massive galaxies.

A forward-modelling approach to overcome point spread function smearing and fit flexible models to the chemical structure of galaxies

ABSTRACT Historically, metallicity profiles of galaxies have been modelled using a radially symmetric, two-parameter linear model, which reveals that most galaxies are more metal-rich in their central regions than their outskirts. However, this model is known to yield inaccurate results when the point spread function (PSF) of a telescope is large. Furthermore, a radially symmetric model cannot capture asymmetric structures within a galaxy. In this work, we present an extension of the popular forward-modelling Python package lenstronomy, which allows the user to overcome both of these obstacles. We demonstrate the new features of this code base through two illustrative examples on simulated data. First, we show that through forward modelling, lenstronomy is able to recover accurately the metallicity gradients of galaxies, even when the PSF is comparable with the size of a galaxy, as long as the data are observed with a sufficient number of pixels. Additionally, we demonstrate how lenstronomy is able to fit irregular metallicity profiles to galaxies that are not well-described by a simple surface brightness profile. This opens up pathways for detailed investigations into the connections between morphology and chemical structure for galaxies at cosmological distances using the transformative capabilities of JWST. Our code is publicly available and open source, and can also be used to model spatial distributions of other galaxy properties that are traced by its surface brightness profile.

Исследование упругопластического изгиба листовой заготовки различной толщины при ее гибке с учетом эффекта пружинения

The work analyzes the process of bending the sheet work piece to obtain shaping of sheet metal parts and profiles. The analysis is carried out on the basis of strength calculations of elastoplastic bending of the metal plate. When pressing such a plate, in practice, a spring effect is observed when the curved blank changes its shape under the influence of residual elastic deformations at the end of the pressing process. To compensate for the spring effect, it is necessary to determine the values of elastic and plastic deformations in the sheet blank. The work considers the method of calculation of these values on the basis of available experimental works. Conclusions have been drawn and practical recommendations can be used in the process of setting process parameters for pressing sheet blanks.

DOMESTIC SEWAGE WASTEWATER IRRIGATION ON QUALITATIVE EVALUATION OF NAPIER GRASS (PENNISETUM PURPUREUM) AND ITS IMPACT ON COW MILK PARAMETERS REFERENCE TO ENVIRONMENTALLY SUSTAINABLE FOOD SECURITY

Domestic sewage wastewater irrigation for the agricultural fields is highly promoted for sustainable water resource management. The present case study investigated domestic sewage wastewater irrigation influences on the agro botanical parameters and biomass productivity of Napier grass. Further, the quality of milk (proximate and mineral composition) has also been checked from cows fed with wastewater-irrigated Napier grass. The study has been conducted in 5 different agricultural fields (4 wastewater irrigated fields and 1 well-water irrigated field as control (A-E)). The results of the study reveal that the physiochemical parameters of all the domestic wastewater samples were within the permissible limit of (FAO-1985)/(WHO-1993) and (BIS-1986) standards. However, all the parameters were found to be higher when compared with the control sample. Interestingly, the agro botanical characteristics of Napier grass grown in semiurban agro field (D) irrigated with wastewater were found to be significantly (P<0.05) higher. However, when compared to all experimental samples, significantly (P<0.05) higher values were observed for proximate compositions of both Napier grass and cow milk samples from agro field A (semi-urban). Moreover, macro-micronutrients and heavy metal profiles in the plant and milk samples were also found to be within acceptable/permissible limits. At this juncture, the results of the study reveal that, due to different mitigation measures, domestic sewage wastewater can be used as a potential organic liquid fertilizer, which will eventually reduce the extraction of freshwater and improve the wastewater reuse for the cultivation of such fodder crops and thereby ensure nature-based and sustainable water resource management.

Modeling the pattern of metal flow during forming of forgings from a flat billet

Parts made of the billets with a thin web and stiffeners are manufactured at metallurgical enterprises in special workshops equipped with powerful hydraulic presses. Often their production is accompanied by the defects that worsen the product macrostructure. In this regard, new techniques are relevant that allow modeling the processes of forming of forgings with stiffeners. The processes of metal processing by pressure are difficult to create a mathematical model describing the stress-strain state of plastic forming of metal. One of the ways to solve the problem of modeling the pattern of metal flow and the spatial diagram of contact pressures is the “theory of thin layer flow”, based on assumptions that simplify the initial system of differential equations. Then the problem is reduced to a purely geometric one and can be solved within the framework of the “sandy analogy” using the proposed methodology. The paper presents the results of computer and physical modeling of the forming of stamped forgings with contour stiffeners. The experiment was carried out in industrial conditions on the precipitation of flat billets made of AK6 alloy on a hydraulic press with a deformation force of 150 MN. It is shown that the proposed software package can have a different functional purpose: express analysis of the pattern of metal flow and calculation of the shape of the billet at the stages of its deformation. This allows, by sorting through values of the geometric parameters of the stamp engraving, to obtain different patterns of metal flow and profiles of stiffeners and choose from them those that guarantee the most uniform filling of the stamp cavities with metal under the stiffeners, which ensures defect-free production of the product.

Spectroscopy of a mesospheric ghost reveals iron emissions

Mesospheric Green emissions from excited Oxygen in Sprite Tops (ghosts) are infrequent and faint greenish transient luminous events that remain for hundreds of milliseconds on top of certain energetic sprites. The main hypothesis to explain this glow persistence is the long lifetime of excited atomic oxygen at 557.73 nm, a well-known emission line in aurora and airglow. However, due to the lack of spectroscopic campaigns to analyse such events to date, the species involved in the process can not yet be identified. Here we report observational results showing the temporal evolution of a ghost spectrum between 500 nm and 600 nm. Besides weak -but certain- traces of excited atomic oxygen, our results show four main contributors related to the slow decay of the glow: atomic iron and nickel, molecular nitrogen and ionic molecular oxygen. Additionally, we are able to identify traces of atomic sodium, and ionic silicon, these observations being consistent with previous direct measurements of density profiles of meteoric metals in the mesosphere and lower thermosphere. This finding calls for an upgrade of current air plasma kinetic understanding under the influence of transient luminous events.

Expression of Concern: Characterising the spatial and temporal brain metal profile in a mouse model of tauopathy.

Expression of Concern: Characterising the spatial and temporal brain metal profile in a mouse model of tauopathy.

Total contents, fractionation and bioaccessibility of nine heavy metals in household dust from 14 cities in China

The potential health risk caused by long-term exposure to heavy metals in household dust is not only depended on their total content, but also bioaccessibility. In this study, twenty-one dust samples were collected from residential buildings, schools, and laboratories in 14 provincial-capital/industrial cities of China, aiming to evaluate the total contents, fractionation, bioaccessibility and health risks of nine heavy metals (As, Cd, Cr, Ni, Pb, Mn, Zn, Fe, and Cu). Results showed that the highest levels of Cd, Cr, Ni and Zn were found in laboratory dust, As, Pb and Mn in school dust, and Fe and Cu in residential dust, indicating different source profiles of the heavy metals. The mean bioaccessibility of the heavy metals across all samples as evaluated using SBRC (Solubility Bioavailability Research Consortium), IVG (In Vitro Gastrointestinal), and PBET (Physiologically Based Extraction Test) assays was 58.4%, 32.4% and 17.2% in gastric phase (GP), and 24.9%, 21.9% and 9.39% in intestinal phase (IP), respectively. Cadmium had the highest content in the fractions of E1+C2 (43.7%), as determined by sequential extraction, and Pb, Mn, and Zn had a higher content in E1+C2+F3 (64.2%, 67.2%, 78.8%), resulting in a higher bioaccessibility of these heavy metals than others. Moreover, the bioaccessibility of most heavy metals was inversely related to dust pH (R = −0.18 in GP; −0.18 in IP; P < 0.01) and particle size, while a positive correlation was observed with total organic carbon (R = 0.40 in GP; 0.38 in IP; P < 0.01). The exposure risk calculated by the highest bioaccessibility was generally lower than that calculated by the total content. However, Pb in one school dust sample had an unacceptable carcinogenic risk (adult risk = 1.19 × 10−4; child risk = 1.08 × 10−4). This study suggests that bioaccessibility of heavy metals in household dust is likely related to geochemical fractions and physical/chemical properties. Further research is needed to explore the sources of bioaccessible heavy metals in household dust.

Lung toxicity, deposition, and clearance of thermal spray coating particles with different metal profiles after inhalation in rats

Thermal spray coating is a process in which molten metal is sprayed onto a surface. Little is known about the health effects associated with these aerosols. Sprague-Dawley rats were exposed to aerosols (25 mg/m3 × 4 hr/d × 4 d) generated during thermal spray coating using different consumables [i.e. stainless-steel wire (PMET731), Ni-based wire (PMET885), Zn-based wire (PMET540)]. Control animals received air. Bronchoalveolar lavage was performed at 4 and 30 d post-exposure to assess lung toxicity. The particles were chain-like agglomerates and similar in size (310–378 nm). Inhalation of PMET885 aerosol caused a significant increase in lung injury and inflammation at both time points. Inhalation of PMET540 aerosol caused a slight but significant increase in lung toxicity at 4 but not 30 d. Exposure to PMET731 aerosol had no effect on lung toxicity. Overall, the lung responses were in the order: PMET885≫PMET540 >PMT731. Following a shorter exposure (25 mg/m3 × 4 h/d × 1d), lung burdens of metals from the different aerosols were determined by ICP-AES at 0, 1, 4 and 30 d post-exposure. Zn was cleared from the lungs at the fastest rate with complete clearance by 4 d post-exposure. Ni, Cr, and Mn had similar rates of clearance as nearly half of the deposited metal was cleared by 4 d. A small but significant percentage of each of these metals persisted in the lungs at 30 d. The pulmonary clearance of Fe was difficult to assess because of inherently high levels of Fe in control lungs.

Characterization and evaluation of stress resistance in the structural bonding of electric cooktops

This work presents the definition and validation of a methodology for assuring proof of conformity of electrical appliances structural bonded joints. Stress and stress resistance calculation for assessing the adhesive bonding is performed. This includes analytical and simulation studies with Finite Element Analysis (FEA), contact substrate area calculation and real components experimental testing under ageing conditions such as high temperature, low temperature and humidity. To achieve this, standard DIN 2304-1:2020-04 was used as a reference for the definition of the methodology and to prove the fulfilment of the bonding requirements for the high quality structural joint design, covering all steps of the adhesive bonding process specially focusing on the joint design. The validation of this methodology was done with an electrical appliance, where metallic profiles are assembled with a ceramic glass by means of an adhesive structural bond. The results of the work prove that the evaluated bonding joint successfully meets the required criteria assuring that the stress is lower than stress resistance value.

United States Grown and Imported Rice on Sale in Las Vegas: Metal(loid)s Composition and Geographic Origin Discrimination.

Concentrations of metal(loid)s, Ag, Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Se, Sr, V and Zn, were determined in rice on sale in Las Vegas. The rice samples were grown in five different countries, the USA, Thailand, India, Pakistan, and Bangladesh. The elemental concentrations in rice grain were determined using inductively coupled plasma mass spectrometry (ICP-MS) following hot block-assisted digestion. The accuracy of the laboratory procedure was verified by the analysis of rice flour standard reference material (NIST SRM 1568b). The mean metal(loid) contents in rice of various geographic origins were 3.18-5.91 mg kg-1 for Al, 0.05-0.12 mg kg-1 for As, 3.64-41 μg kg-1 for Cd, 5.11-12 μg kg-1 for Co, 0.12-0.14 mg kg-1 for Cr, 1.5-1.91 mg kg-1 for Cu, 3.04-4.98 mg kg-1 for Fe, 4.2-10.4 mg kg-1 for Mn, 0.21-0.41 mg kg-1 for Ni, 0.02-0.07 mg kg-1 for Se, 0.68-0.88 mg kg-1 for Sr, 3.64-5.26 μg kg-1 for V, and 16.6-19.9 mg kg-1 for Zn. respectively. The mean concentration of As in US rice was significantly higher than in Indian, Pakistani, and Bangladeshi rice. On the other hand, it was found a significantly low mean level of Cd in US-grown rice. It was also found that the concentrations of metal(loid)s in black and brown rice on sale in Las Vegas were statistically similar, except for Mn and Se. The geographic origin traceability of rice grain involved the use of ICP-MS analysis coupled with chemometrics that allowed their differentiation based on the rice metal(loid) profile, thus confirming their origins. Data were processed by linear discriminant analysis, and US and Thai rice samples were cross-validated with higher accuracy (100%). This authentication quickly discriminates US rice from the other regions and adds verifiable food safety measures for consumers.

Heavy metal and persistent organic pollutant profile of sediments from marine protected areas: the northern Persian Gulf.

Marine protected areas (MPAs) are one of the policy tools to support marine biodiversity conservation and sustainable use of marine resources. The distribution, sources, and ecological risk assessment of persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbon (PAHs), total petroleum hydrocarbons (TPHs), polychlorinated biphenyls (PCBs), and heavy metals (HMs) in sediments of MPAs in the northern Persian Gulf, were evaluated for the first time in this study. The Σ16PAHs ranged from 4.65 to 20.86 μg/kg dry weight (dw). The molecular ratios and ring's pattern of PAHs suggested a mixed origin with a predominance of pyrogenic sources. The TPH concentration varied from 5.21 to 17.90 μg/g dw. Ecological risk assessment suggested that sediment samples in Bushehr Province's MPAs can be categorized as medium risk. The mean concentration of ∑18PCB was 0.345-0.419 ng/g dw, and the main components correspond to PCB-77, PCB-105, PCB-81, PCB-101, and PCB-114. The mean concentration of As, Co, Cr, Ni, V, Mg, Pb, Zn, Cu, Al, and Fe varied from 4.79 to 9.69, 2-12, 39-142, 18-90, 15-58, 184-425, 7-45.9, 6-42.4, 4-20 μg/g dw, 0.75-4.12%, and 0.35-1.62%, respectively. Multivariate analysis, such as principal component analysis (PCA) and cluster analysis (CA), coupled with correlation coefficient analysis, was used to analyze the analytical data and to identify possible pollution sources. The results of this study provided the background information on the extent of POP contamination in the sediment and highlighted the need to further control pollution in MPAs.

Heavy metal concentration according to shrimp species and organ specificity: Monitoring and human risk assessment

This study assessed heavy metal levels (lead (Pb), cadmium (Cd), total arsenic (tAs), arsenite (As (III)), arsenate (As (V)), monomethyl arsenic acid (MMA), dimethylarsinic acid (DMA), total mercury (tHg), and methylmercury (MeHg)) in six organs (total portion, head, body, shell, muscle, and intestine) of 11 shrimp species distributed in Korea. Shrimp exhibited significant variability in heavy metal accumulation, with Alaskan pink and dried shrimp (Lesser glass, Southern rough, and Chinese ditch prawn) showing the highest metal concentrations. Notably, the intestine having the highest overall metal content, while Cd was most prominent in the head, tHg was highest in the muscle. The Hazard Quotient values of 11 shrimp species in South Korea were below the European Food Safety Authority's allowable limits for heavy metals. This study illuminates the heavy metal profiles of distributed shrimp in Korea and emphasizes the ongoing need for monitoring heavy metals on seafood to ensure consumer safety.

Harmful Substances in Cosmetics and Impact on Ocean

The article expresses the toxicological profile of micro plastics, heavy metals and active ingredients on cosmetics. The focus is on pollution hazards to the biosphere, humans and the environment. Animals easily absorb plastic particles, which not only spread throughout the food chain, but have also been shown to exist in humans. While the micro plastics in cosmetic bags themselves can leach toxins into the ocean, synergies between micro plastics and other pollutants can increase the toxicity of micro plastics to living things. Cosmetics are also harmful in the use of processing additives, polypropylene like absorb organic pollutants. In the future, in order to reduce the environmental pollution of cosmetics, we should use green cosmetics and reduce the use of packaging bags.

Historical trend of heavy metals in mangrove sediment from Nusa Lembongan, Bali using 210Pb-geochronology

Mangrove sediment is a natural filter for retaining pollutants before entering the coastal area and ocean. This study collected sediment cores from a Marine Protected Area (MPA) in Nusa Lembongan, Bali, to establish 210Pb geochronology and heavy metals records. Alpha spectrometry and Instrumental Neutron Activation Analysis (INAA) were used to determine 210Pb and heavy metals (Co, Cr, Fe, Hf, Sb, Sc, Se, and Zn), respectively. The Contamination Factor (CF), Enrichment Factor (EF), and Geo-accumulation Index (I_geo) were assessed. The result shows that 210Pb provided records of sediment accumulation spanning approximately 100 years. The vertical profiles of all heavy metals from the 1910s to the 1930s were slightly constant. From the 1930s to the 1990s, the profiles of Co, Cr, Hf, Sb, Sc, and Zn slightly increased; meanwhile, Fe and Se were slightly constant. From the 1990s to 2017, all heavy metals decreased gradually. Based on the CF, heavy metals Cr, Hf, Sb, Sc, and Zn were categorized as moderate contamination, and Co, Fe, and Se were low contamination. The average EFs of all heavy metals suggested their origin was derived from crustal material. In the I_geo index, only Sb was classified as moderate pollution, while the other heavy metals were not pollutants.

Environmental safety of soil genetic horizons in the impact zone of Lviv city landfill (Ukraine)

Landfills cause significant technogenic pressure on the environment, being the center of depositing large volumes of hazardous materials in a relatively small area. Interacting with each other they form hazardous substances and compounds. In this study, we describe three genetic soil horizons that are within the impact zone of the landfill of a city of millions of people. It was established that the distribution of mobile forms of heavy metals according to the profile of the studied soils tended to gradual decrease with depth. When describing the genetic horizons of three profiles located in the impact zone of the landfill, it was established that the content of heavy metals in them does not exceed the MPC, except for Pb. The soil at the foot of the landfill turned out to be the most contaminated with heavy metals (profile No. 3). The activity of micromycetes in this soil was the lowest here. In general, all soils in the impact area of the landfill are impoverished in micromycete distribution. The taxonomic composition of mycelial fungi and the identified species’ ecological and biological characteristics indicate significant ecosystem pollution by household waste.

The organoleptic, chemical and microbiological quality of maggot s frass as alternative poultry feed ingredients

Maggot’s frass is waste from cultivating maggots (insect larvae) which consists of media from maggot cultivation mixed with feces, skin and dead body of the maggots. The aim of the study was to examine the organoleptic quality, chemistry, worm eggs, lead (Pb) as heavy metal and microbiological profile of maggot’s frass as an alternative ingredient of poultry feed. A completely randomized design (CRD) with 3 treatments (T1: frass media for household waste, T2: frass media for tofu dregs, and T3: frass media for vegetable and fruit waste) and 7 replications was used. The results showed that there was no effect of different types of media treatment on the organoleptic quality, chemistry and microbiological profile of maggot’s frass. The results of chemical analysis of maggot’s frass revealed moisture of 26.39 - 46.26%, crude protein of 10.92 - 16.37%, worm eggs in the dregs media tofu (16 EPG), vegetable and fruit waste (32 EPG), total bacteria of 1.91-4.95 x 108cfu/g, and no any Escherichia coli and Salmonella isolates. Maggot’s frass which comes from fruit and vegetable waste was recommended. Therefore, maggot feed using fruit and vegetable waste treatment is recommended because of its high crude protein and metabolic energy and also without any E.coli and Salmonella contamination.

MI-Poser

Inside-out tracking of human body poses using wearable sensors holds significant potential for AR/VR applications, such as remote communication through 3D avatars with expressive body language. Current inside-out systems often rely on vision-based methods utilizing handheld controllers or incorporating densely distributed body-worn IMU sensors. The former limits hands-free and occlusion-robust interactions, while the latter is plagued by inadequate accuracy and jittering. We introduce a novel body tracking system, MI-Poser, which employs AR glasses and two wrist-worn electromagnetic field (EMF) sensors to achieve high-fidelity upper-body pose estimation while mitigating metal interference. Our lightweight system demonstrates a minimal error (6.6 cm mean joint position error) with real-world data collected from 10 participants. It remains robust against various upper-body movements and operates efficiently at 60 Hz. Furthermore, by incorporating an IMU sensor co-located with the EMF sensor, MI-Poser presents solutions to counteract the effects of metal interference, which inherently disrupts the EMF signal during tracking. Our evaluation effectively showcases the successful detection and correction of interference using our EMF-IMU fusion approach across environments with diverse metal profiles. Ultimately, MI-Poser offers a practical pose tracking system, particularly suited for body-centric AR applications.

Health Risks from Intake and Contact with Toxic Metal-Contaminated Water from Pager River, Uganda.

Pollution of water resources is one of the major impediments to the realization of Sustainable Development Goals, especially in developing countries. The aim of this study was to investigate the physicochemical quality and potentially toxic element (lead and cadmium) concentrations in surface water sampled from Pager River, a tributary of the Nile River in Northern Uganda. Water samples (n = 18) were taken from six different points upstream (A, B, and C) and downstream (D, E, and F) of the river and analyzed following standard methods for their physiochemical properties. Atomic absorption spectroscopy was used to quantify lead and cadmium concentrations. Human health risks from ingestion and dermal contact with potentially toxic metal-contaminated water were calculated. The results obtained indicated that the mean temperature (27.7 ± 0.5-29.5 ± 0.8 °C), turbidity (40.7 ± 2.1-50.1 ± 1.1 NTU), lead (0.296 ± 0.030-0.576 ± 0.163 mg/L) and cadmium (0.278 ± 0.040-0.524 ± 0.040 mg/L) occurred at levels that surpassed their permissible limits as per World Health Organization guidelines for drinking water. Human health risk assessment showed that there are potential non-cancer risks from the ingestion of water from Pager River by adults, as the total hazard quotients were greater than one. These results emphasize the urgency to restrict the dumping of wastes into the river to minimize chances of impacting the Nile River, which flows northwards to the Mediterranean Sea. Further studies should perform routine monitoring of the river during both dry and wet seasons to establish the spatiotemporal variations of physicochemical, microbial, and trace metal profiles of the river and the associated health risks.

"Sacred Zamzam Water: Metallic Profile and Health Benefits"

"Sacred Zamzam Water: Metallic Profile and Health Benefits"