Amount Of Copper Research Articles

"Evaluation of Health Status and Effects of Thermal Power Plant Pollutants on the Population's Health and the Environment around the Plant"

The quality of the soil, air, and water are significantly impacted by coal-fired thermal power plants (TPPs), which negatively affects the surrounding environment and human health. The current study's goals were to detect specific heavy metals in fly ash, air, water, and soil samples, as well as to evaluate the respiratory health of the community living close to the plant. Materials and Procedures In the current cross-sectional study, 3533 adult people from two strata within a 10-kilometer radius of the TPP in the Karnataka state's Udupi district participated. Semi-structured questionnaires, spirometry, environmental air monitoring with a DustTrak aerosol monitor, water samples, and soil samples were used to obtain the data. Results: The majority of the study's participants were over 45 years old (41.4 percent). There were 70.6 percent females and 0.39 percent transgender people. There were different respiratory issues in 4.3 percent of the population. According to bivariable logistic regression, participants aged 46–65 and >65 respectively had 2.91- and 4.42-times greater risks of respiratory disease than those aged 45 years. The results of multivariable logistic regression revealed a significant correlation between older age groups and subjects who had closed their windows while cooking (P 0.006). While the amounts of iron, manganese, and copper in the ground water samples were overly high, the levels of heavy metals in soil samples and particulate matter 2.5 were well within allowable limits. The results of this study have consequences for the formulation of policies that safeguard the environment and human health.

Effects of Supplemental UV-A LEDs on the Nutritional Quality of Lettuce: Accumulation of Protein and Other Essential Nutrients

Light plays an important role in influencing the nutritional quality of food crops, especially with regard to the health-promoting phytochemicals. However, its role in affecting the nutritional quality with regard to the essential nutrients is not well understood. In this study, the effects of preharvest UV-A treatment on the nutritional quality of lettuce (Lactuca sativa, cv. red-leaf ‘New Red Fire’ and green-leaf ‘Two Star’) in relation to the essential nutrients and health-promoting phytochemicals were explored. Lettuce plants were grown in a growth chamber and were subjected to supplemental UV-A LEDs (peak wavelength 375 nm) for a brief period (3–6 days) prior to harvest. UV-A LEDs were equipped with lenses to control the light dispersion. Many growth indices such as shoot fresh mass, leaf area, and leaf number were unaffected by supplemental UV-A in both varieties while shoot dry mass decreased in response to a 6-day UV-A treatment compared to the control. Leaf chlorophyll and carotenoid concentrations increased significantly in green-leaf lettuce after 3 or 6 days of UV-A treatment, but only after 3 days of UV-A treatment in red-leaf lettuce compared to the control. Leaf protein concentration increased significantly in both lettuce varieties along with a number of essential nutrients such as phosphorus, potassium, calcium, manganese, and sulfur in response to supplemental UV-A. Supplemental UV-A increased the accumulation of protein by approximately 48% in green-leaf lettuce and 31% in red-leaf lettuce compared to the control plants. Moreover, in addition to the above essential nutrients, green-leaf lettuce accumulated higher amounts of magnesium, copper, and zinc compared to the control plants, indicating that green-leaf lettuce was more responsive to preharvest supplemental UV-A treatment than red-leaf lettuce. However, the accumulation of total phenolic compounds and flavonoids in both varieties was lower under supplemental UV-A. Furthermore, the use of LED lenses did not have a consistent impact on most of the plant responses studied. Overall, the results indicate that a brief preharvest exposure of both red- and green-leaf lettuce varieties to UV-A increased their nutritional quality by enhancing the accumulation of protein and other major essential nutrients.

Distribution, Assessment, and Source of Heavy Metals in Sediments of the Qinjiang River, China.

Heavy metals are toxic, persistent, and non-degradable. After sedimentation and adsorption, they accumulate in water sediments. The aim of this study was to assess the extent of heavy metal pollution of Qinjiang River sediments and its effects on the ecological environment and apportioning sources. The mean total concentrations of Mn, Zn, Cr, Cu, and Pb are 3.14, 2.33, 1.39, 5.79, and 1.33 times higher than the background values, respectively. Co, Ni, and Cd concentrations are lower than the background values. Fe, Co, Ni, Cd, Cr, Cu, and Pb are all primarily in the residual state, while Mn and Zn are primarily in the acid-soluble and oxidizable states, respectively. Igeo, RI, SQGs, and RAC together indicate that the pollution status and ecological risk of heavy metals in Qinjiang River sediments are generally moderate; among them, Fe, Co, Ni, Cd, Cr, and Pb are not harmful to the ecological environment of the Qinjiang River. Cu is not readily released because of its higher residual composition, suggesting that Cu is less harmful to the ecological environment. Mn and Zn, as the primary pollution factors of the Qinjiang River, are harmful to the ecological environment. This heavy metal pollution in surface sediments of the Qinjiang River primarily comes from manganese and zinc ore mining. Manganese carbonate and its weathered secondary manganese oxide are frequently associated with a significant amount of residual copper and Cd, as a higher pH is suitable for the deposition and enrichment of these heavy metals. Lead–zinc ore and its weathering products form organic compounds with residual Fe, Co, Cr, and Ni, and their content is related to salinity. The risk assessment results of heavy metals in sediments provide an important theoretical basis for the prevention and control of heavy metal pollution in Qinjiang River.

Effect of Supporting Anion for Copper Corrosion in Gas Diffusion Microenvironments

Copper is used in a variety of capacities in the development of renewable energy technologies, including as a catalyst on gas diffusion electrodes in electrochemical devices such as CO2 reduction devices. By gaining a better understanding of Cu corrosion, we can learn more about the durability of devices that utilize copper. However, there are a myriad of factors that influence the kinetics of metal corrosion and deposition, which increases the difficulty to precisely analyze the fundamentals. Factors of concern include adsorbing/desorbing multiple layers of metal, uneven surfaces, defects on the electrode surface, and changes in electrode crystal facets. To mitigate these factors, obtain a more representative picture of Cu corrosion, and investigate the effect of the anions on copper, we created three model systems by employing copper underpotential deposition (UPD) on a single-crystalline Au[111] surface: 1) a phenomenal model system in sulfuric acid; 2) a bridging environment (methane sulfonic acid); and 3) a model microenvironment for gas diffusion (Nafion electrolyte). As a result, a loss in peak sharpness, as well as an increase in the number of peaks that are less resolved were observed in phenomenal and bridging environment, respectively, and a loss in ordered monolayers was seen in model microenvironment. Surprisingly, sulfuric acid and methane sulfonic acid have similar charges passed indicating the same amount of copper is deposited and stripped, whereas much less charge is passed in Nafion, demonstrating that small changes to the supporting anion can have a large effect on Cu UPD structure. As the real world does not exist in a model system, our model microenvironment will provide a better image of Cu corrosion fundamentals in a gas diffusion electrode, which is critical for electrochemical devices application. Figure 1

Photocatalytic efficiency of undoped and Cu-doped ZnO thin films coated inside transparent glass tube as one-piece photoreactor

In recent years, the contaminated rejects due to the rise of textile and dye industry have dramatically affected the ecosystem and aquatic reserves. In addition, the decontamination of organic species based on nanoparticles as photocatalyst is considered as a complicated route and material consumer. To address the separation issue, it is necessary to develop new methods to degrade organic dyes through coast effective processes. In this context, we present in our study a new photocatalysis design by implementation of the photocatalyst on the inner side surface of transparent glass tube as one piece-photoreactor. Among various Photocatalysis based on metal-oxide materials, zinc oxide is widely studied by tailoring its physical and chemical properties to improve the photocatalytic degradation activity. Accordingly, pure and Cu-doped ZnO catalysts with variable copper amount (1, 2.5 and 4 wt%) were synthesized by ultrasonic spray pyrolysis and characterized by X-ray diffraction (XRD), Raman spectroscopy, UV–visible spectroscopy, Photoluminescence spectroscopy (RT-PL), Atomic force microscopy (AFM), Scanning electron microscopy (SEM), Complex impedance spectroscopy and X-ray photoelectron spectroscopy (XPS). The methylene blue degradation rate was investigated through the decrease of the absorption band situated at 663 nm under UV–Vis irradiation. The reusability of the undoped and Cu-doped ZnO photocatalyst tests after six recycles give a steady photodegradation efficiency results.

Effect of deep oxidation of chalcopyrite on surface properties and flotation performance

In this study, chalcopyrite was oxidized in hydrogen peroxide (H 2 O 2 ) solutions of different concentrations to simulate different degrees of oxidation in real ores, and the effects of H 2 O 2 treatment on chalcopyrite surface properties and flotation performance were investigated by surface analysis techniques and floatation experiments, which implied the reason for the poor grade and recovery of oxidized chalcopyrite concentrate in the production process of the ore. Flotation results showed that when the concentration of H 2 O 2 increased from 0% (by weight) to 5%, the flotation recovery of chalcopyrite decreased sharply. However, with increasing H 2 O 2 concentration from 5% to 30%, chalcopyrite recovery improved relatively to different degrees with different collector concentrations. Analyses of X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-atomic optical emission spectrophotometry (ICP-OES) results indicated that the pretreatment with H 2 O 2 caused that hydrophilic substance formed on chalcopyrite surface with the dissolution of copper ions, and the dissolution amount of copper increased with the increase of H 2 O 2 concentration. UV–visible spectrophotometer and Fourier Transform Infrared spectrum (FTIR) studies indicated that the pretreatment of chalcopyrite with H 2 O 2 had little effect on the adsorption amount of potassium butyl xanthate (PBX) on chalcopyrite surface. However, due to the dissolution of copper ions, PBX interacted with chalcopyrite mainly as buthyl dixanthogen (BX) 2 .

Genesis of Cobalt Mineralisation Associated With Kalyadi Schist Belt, Dharwar Craton, South India: A Petrological and Fluid Inclusion Study

The Sargur Group of rocks belonging to the Kalyadi Schist Belt (KSB) in the Western Dharwar Craton (WDC) occur as large linear enclaves within younger peninsular gneisses. This belt is known for copper mineralization and exploited good amount of copper for many years. Recent studies have shown significant concentration of cobalt up to 2000 ppm associated with copper in this belt. Earlier studies have indicated pyrite containing cobalt in its crystal lattice. In the present study an attempt has been made to understand the genesis of cobalt mineralization in this belt through detailed petrography, fluid inclusion studies along with chlorite chemistry. Two distinct ore mineral assemblages and fluid sources are proposed based on ore petrography, mineral chemistry and fluid inclusion studies. In the initial stage chalcopyrite1 is associated with cobalt bearing pyrite and magnetite and in the later stage chalcopyrite2 is associated with arsenopyrite, pyrrhotite and safflorite [(Co, As) As2]. The initial stage fluids are characterized by low saline (~ 5 wt % NaCl equivalent) and slightly higher temperature (268° to 300° C with pressure ranging from 1.9 to 2.3 Kb), which are almost similar to temperatures obtained from the chlorite i.e. 202.8° to 322.43° C, this indicates that the fluids are related to regional low grade greenschist facies metamorphism. On the contrary, the late stage fluids are characterized by high density and high saline nature and show temperature range varying from162° to 224° C with pressure values ranging from 1.4 to 1.9 Kb and in addition native Bi association suggest their derivation from the granitic or felsic magmatic source associated with emplacement of the Desani Granite in the study area. Presence of safflorite mineral associated with the second stage fluids and mineral assemblage suggest that the remobilization Co from the crystal lattice of pyrite and chalcopyrite has occurred. Keywords: Cobalt mineralisation, Sargur Group of Rocks, Kalyadi Schist Belt (KSB), Western Dharwar Craton

Nutritional Composition and Volatile Compounds of Black Cumin (Nigella sativa L.) Seed, Fatty Acid Composition and Tocopherols, Polyphenols, and Antioxidant Activity of Its Essential Oil

This study was to assess the nutritional quality and bioactive properties of black cumin (Nigella sativa L.) seeds and oil commonly found in the Chinese market. The results showed that black cumin seeds contain 5.02, 21.07, 39.02, 3.02, 6.01, and 25.86% moisture, crude proteins, crude fat, ash, fiber, and carbohydrates, respectively. It also contains substantial amounts of minerals, namely calcium, potassium, phosphorus, magnesium, sodium, iron, zinc, and copper. Glutamic acid (4.10 g/100 g protein) is the major amino acid of black cumin seeds. The major volatile components in black cumin seeds were thymoquinone (21.01%), o-cymene (18.23%), and β-thujene (17.22%). Cumin seed oil extracted by the soxhlet method contains high quantities of unsaturated fatty acids (UFA; 85.16%) and low amounts of saturated fatty acids (SFA; 15.02%). The major fatty acid of black cumin seed oil was linoleic acid (57.71%), followed by oleic acid (24.46%). The most prominent TAG of black cumin seed oils was oleoyl-dilinoleoyl-glycerol (OLL; 38.87%). In addition, the levels of α-tocopherol, β-tocopherol, γ-tocopherol, and total polyphenols in the black cumin seed oil were 25.59, 14.21, and 242.83 mg/100 g, and 315.68 mg GAE/kg, respectively, and possessed high antioxidant activity (DPPH IC50%, of 4.02 mg/mL). These findings demonstrate that black cumin seeds are nutritionally rich with high potential applications in the food, pharmaceutical, and cosmetic industries.

Copper‐Catalyzed Carbonylative Cross‐Coupling of Alkyl Iodides and Amines

A general copper-catalyzed carbonylative cross-coupling between amines and alkyl iodides is reported. Using a simple combination of catalytic amounts of copper(I) chloride and N , N , N' , N" , N" -pentamethyldiethylenetriamine in the presence of sodium hydroxide under carbon monoxide pressure, a broad range of alkyl iodides and amines can be efficiently coupled to the corresponding amides that are obtained in good to excellent yields. Notable features of this process - the first one relying on a base metal catalyst - include the availability and low cost of the catalytic system, its successful use with primary, secondary, tertiary alkyl iodides and all classes of amines - with no or limited competing nucleophilic substitution without CO incorporation - as well as its efficiency with complex alkyl iodides and amines . Mechanistic studies demonstrated that a radical pathway is operative and the key role of CO.

Comparison of toxic effects of lead and copper and protective power of glutathione on oxidative stress parameters

IntroductionLead as an industrial pollutant can be detected at all stages of the working and living environment. Lead, based on its properties, solubility and mobility, accumulates in the soil, so that the average concentrations of oil in the soil are between 15 and 25 mg/kg (Radojević at all., 1999). Due to increased human activity, the amount of copper in the air, soil and water has increased. Glutathione (GSH) is an essential cofactor of many enzymes, such as: formaldehyde dehydrogenase, glyoxalase, prostaglandin endoperoxide isomerase, dehydrochlorinase and others. GSH is a biological redox in the metabolism of erythrocytes, it also plays a role in the transport of amino acids. Reactive forms of oxygen cause oxidative biomolecules (lipids, proteins, DNA) (Freidovich, 1999; Massaad i Klann, 2010).ObjectivesThe aim of this research was to examine the protective role of supplements GSH in conditions of chronic intoxication with sublethal doses of lead acetate and copper II sulfate.MethodsThe preparation of biomaterials for testing and making homogenates of brain tissue of albino rats of Wistar strain was performed and the activity of acid and alkaline DNase was measured spectrophotometrically (Kocić i sar., 1998).ResultsLead otherwise “as soft Lewis acid” has a pronounced affinity for interaction with “soft bases” such as S-atoms of the thiol group in antioxidants, natural biomolecules and supplements in this case in glutathione.ConclusionsIt can be said that GSH is a desirable supplement and antioxidant in the detoxification of reactive oxygen species in rats exposed to lead poisoning.DisclosureNo significant relationships.

Mussel-Inspired Multicomponent Codeposition Strategy toward Antibacterial and Lubricating Multifunctional Coatings on Bioimplants.

Bacterial infections and limited surface lubrication are the two key challenges for bioimplants in dynamic contact with tissues. However, the simultaneous lubricating and antibacterial properties of the bioimplants have rarely been investigated. In this work, we successfully developed a multifunctional coating with simultaneous antibacterial and lubricating properties for surface functionalization of bioimplant materials. The multifunctional coating was fabricated on a polyurethane (PU) substrate via polydopamine (PDA)-assisted multicomponent codeposition, containing polyethyleneimine (PEI) and trace amounts of copper (Cu) as synergistic antibacterial components and zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) as the lubricating component. The obtained PDA(Cu)/PEI/PMPC coating showed excellent antibacterial activity (antibacterial efficiency: ∼99%) to both Escherichia coli and Staphylococcus aureus compared with bare PU. The excellent antibacterial properties were attributed to the combined effect of anti-adhesion capability of hydrophilic PMPC and PEI and bactericidal activity of Cu in the coating. Meanwhile, the coefficient of friction of the coating was significantly decreased by ∼52% compared with bare PU owing to the high hydration feature of PMPC, suggesting the superior lubricating property. Furthermore, the PDA(Cu)/PEI/PMPC coating was highly biocompatible toward human umbilical vein endothelial cells demonstrated by in vitro cytotoxicity tests. This study not only contributes to the chemistry of PDA-assisted multicomponent codeposition but also provides a facile and practical way for rational design of multifunctional coatings for medical devices.

Use of exhausted biosorbent ash as ecofriendly filler in natural rubber

Biosorption is a promising cost-effective clean-up technology for treating wastewater laden with heavy metals. However, the commercial application of biosorption technologies has been limited because a large amount of toxic waste is left behind in this process. The post-sorbents need to be handled in a way that does not negatively affect the environment. In this research, one possibility to solve this problem was proposed and developed: incineration of used adsorbent, followed by the use of the obtained ash as a filler in rubber production. The results showed that the addition of biosorbent ash does not significantly affect the rubber mechanical and elastic properties. The ash addition affected only the beginning of the vulcanization by increasing the activation energy of the curing chemical reaction. This property can be used to prevent the premature start of vulcanization. Furthermore, it was determined whether and to what extent the ash-filled rubber releases metal ions in contact with water. Results showed that the amount of copper leached from rubber samples was negligible compared to the copper that remained permanently built in the rubber. Therefore, this novel approach to utilizing saturated biosorbents as rubber fillers is acceptable from the environmental safety perspective. © 2022 Society of Industrial Chemistry.

Fast photodetection in eco-friendly wurtzite CuInS2 nanocrystals based photodiode with a planar geometry

This study describes the optoelectronic characteristics of CuInS2 nanocrystals (NCs) in wurtzite (WZ) stoichiometry. Non-toxic CuInS2 NCs are successfully synthesized via simple solvothermal method with no secondary phases, due to proper control of copper, indium and sulfide precursors amount. Pure CuInS2 NCs based planar photodetector geometry provides a strong photo-response upon excitation from 390 nm to 950 nm optical spectra, including responsivity up to 21 AW-1, detectivity of 9.8 × 1011 Jones and response-speed of ∼ Tr/Tf = 2.32 s/4.93 s, at 950 nm wavelength. Moreover, to realize a fast response-time, a simple strategy is presented based on providing one vertical photodetector geometry in the lateral form. We designed a micro-spaced trench (channel length ∼ 40 μm) on FTO/glass substrate using CO2 laser. The device shows a noticeably fast response-time ∼ 60 ms over the whole examined spectral range, concomitant with responsivity and detectivity of 264.9 mAW−1 and 7.9 × 1010 Jones at 950 nm wavelength. The fast response-time could be attributed to the photovoltaic mode and the built-in electrical field at the interface between CuInS2 NCs and electron/hole transport layers. This device architecture may provide a proper route toward simple and low-cost alternative designs for photodetectors.

Phytochemical Investigation and Determination of Antibacterial Activities of the Fruit and Leaf Crude Extract of Ficus palmata

To cure ailments, the global population makes medicines from plants. Ficus palmata can be used to cure a variety of ailments. The purpose of this study was to examine the phytochemical content and antibacterial activity of methanol extract from Ficus palmata fruit and leaf crude extract. Maceration was used to make the methanol extracts, which were subsequently fractionated. The crude extracts and fractions were subjected to standard phytochemical screening assays. Phytochemical screening revealed the presence of flavonoids, alkaloids, saponins, tannins, polyphenols, anthraquinones, steroids, coumarins, and terpenoids in the crude methanol fruit extract. Phytochemical screening revealed the presence of flavonoids, alkaloids, tannins, polyphenols, anthraquinones, steroids, and terpenoids in the extract. The determination of trace metals in leaves and fruit samples using a flame atomic absorption spectrophotometer revealed that the fruits contained relatively high quantities of iron and other nutritionally essential elements, such as magnesium, calcium, and copper, whereas the leaves contain a high level of calcium, magnesium, and iron, as well as a small amount of copper.

Biosorption of heavy metals in automobile panel workshop effluent using Bacillus safensis LAU13

Heavy metals are natural constituents of the environment, but improper application for human activities has altered their geochemical compositions and biochemical balance. There is a need to remediate heavy metals released into natural resources through anthropogenic activities. This paper centers on remediation by biosorption as an effective technique for reduction in the concentration of Mn, Co, Cu, Fe, Zn, Hg, Se, Cr, Pb and Cd using Bacillus safensis LAU13.Wastewater samples were obtained from Gbade automobile panel workshop, Grammar School area, Ogbomoso, Nigeria. Initial concentrations of heavy metals in the effluent samples after digestion were determined through Atomic Absorption Spectrometery (AAS). The glucose enriched wastewater samples were autoclaved, the inoculums cultured and subjected to bio-treatment using 250, 500, 750 and1000 µL dosages of Bacillus safensis LAU 13 (Gen Bank accession number KJ461434), a Gram-positive, mesophilic, spore-forming, aerobic and chemo- heterotrophic bacterium. Optical density of inoculated samples was determined through spectrophotometer and the growth monitored for 48hrs. Residual pellets were subjected to Scanning Electron Microscopy (SEM). Results showed that 100% removal was achieved for Mn2+ and Co3+. Chromium was reduced to a very minimal concentration, Zn2+, Cu3+, Pb4+and Se4+ were above average in the irremediation. Fe2+and Cd2+were remediated below average but very low remediation of Hg2+ with less than one percent removal. Optical density increased significantly showing rapid growth of micro-organism irrespective of glucose supplement, and 250 µL inoculum dosage has the optimum performance. SEM micrographs indicate certain accumulated aggregates taken as remediated heavy metals. The study confirmed efficiency of biosorption technique as an alternative to the conventional treatment methods of huge cost, and high precipitates and slurry. B. safensis LAU13 is therefore recommended as a bio-remediating agent in treating automobile workshop effluents with high amount of manganese, cobalt, chromium, zinc, copper, lead and selenium.

Acid recovery from molybdenum metallurgical wastewater via selective electrodialysis and nanofiltration

The molybdenum mining industry discharges a large volume of acidic wastewater containing significant amounts of molybdenum, copper, and other non-valuable metals. In this study, the separation of metal ions (Mo6+, Fe2+, Ca2+, Na+) and recovery of sulfuric acid from molybdenum metallurgical wastewater were investigated via selective electrodialysis (SED) and nanofiltration (NF). A constant voltage of 6 V and volume ratio between the diluent and concentrate chamber of 1:1 was optimized for SED with a highest acid recovery of 89.6% and Mo6+ rejection rate of 98.1%. In contrast, an optimized operating pressure of 1.0 MPa led to highest acid recovery rate of 59.1% and Mo6+ rejection rate of 96.3% in the NF process. The comparison between SED and NF suggests that SED is more competitive than NF for this wastewater treatment with less energy consumption, higher acid recovery rate and higher purity for the recovered acid. Furthermore, coupling NF with SED could reach an acid recovery rate of over 94.2%. Moreover, it was feasible to convert the residual solution of the membrane process into MoO3 nanoparticles by post-treatment. Therefore, it could be concluded that SED and NF are both promising technologies for acid recovery from molybdenum metallurgical wastewater.

Surface chemical and geometrical properties of pure copper powder intended for binder jetting and sintering

One novel important application of sinter‐based additive manufacturing involving binder jetting is copper‐based products. Three different variants of nominally pure copper powder having particle size distributions with D90 < 16, 22, or 31 μm were investigated in this study. The packing behavior and the flow properties using dynamic test and shear cell, as well as specific surface area were evaluated. The analyses employed illustrate the multidimensional complexity. Because different measurements capture different aspect of the powder, it is imperative to apply a characterization approach involving different methods. Surface chemical analysis by means of X‐ray photoelectron spectroscopy (XPS) showed that all powder variants were covered by Cu2O, CuO, and Cu (OH)2, with Cu2O being dominant in all cases. The finest powder with D90 < 16 μm tended to have higher relative amount of copper in divalent state. The average apparent oxide thickness estimated by XPS depth profiling showed that the two coarser variants had similar overall average oxide thickness, whereas the finest one possessed smaller oxide thickness. The surface chemistry of the powder grades is found to be related to their rheological behavior in dynamic condition. Considering the specific surface areas in combination with the average oxide thicknesses, the amount of surface bound oxygen was estimated to be about ~220 ppm for all three variants. Specific concerns need to be taken during the sintering of powder to keep oxygen level below that of electrolytic pitch copper (400 ppm).

New insight into Bronze Age goldwork from northern Portugal. Bracelets, spirals and torcs from the region of Vila Real

This work is the first analytical study carried out on a representative group of early gold objects found in the region of Vila Real, situated in one of the richest gold-bearing areas in the northwest of the Iberian Peninsula. The objects were examined by optical microscopy and mobile XRF in four museums. Among them are the unique Early Bronze Age spiral ring from Vila Real (found at Fraga da Pitorca), one of the three chains of gold spirals from North Portugal and one of the few Villena-Estremoz type bracelets found in the Northwest (both from Alto da Pedisqueira). They constitute the Treasure of Chaves. Two of the three Bronze Age bracelets from Vila Real (found at Torgueda and Vinhós) have also been analysed together with typical productions of the region of Chaves, the Iron Age torcs from Rendufe, Codeçais and Paradela do Rio. Two similar torcs found in Lugo were analysed for comparison. When the earliest objects from Vila Real are compared to those found in neighbouring regions (Bragança, Minho and Galicia), they suggest regional exploitation of local gold resources. In Vila Real, native gold seems to be used as found until at least the end of the Bronze Age, but search and implementation of metallurgical practices related to several stages of production of intentional gold alloys seem to begin in the Early Iron Age. Some objects are made with gold containing a little more copper but amounts of silver within the same range as earlier objects, suggesting the addition of copper to local native gold, whereas others, particularly the torcs, contain increasing amounts of silver and copper. When copper and increasing amounts of silver are added to a gold containing 10 wt% Ag and 0.2 wt% Cu (native alloy observed at Vila Real) the theoretical debased alloys cover the chemical range defined by objects dated from the Iron Age to the early Roman period found north of Douro river, suggesting the use of well-established metallurgical practices.

Polymerizable thioureas as innovative reducing agents for self-cured and dual-cured dental materials

ObjectiveTo evaluate polymerizable acylthioureas as reducing agents in two-component dental materials. MethodsAcylthioureas 1 and 2 were synthesized and characterized by 1H and 13C NMR spectroscopy. Self-cured composites based on the redox initiator system cumene hydroperoxide/acylthiourea 1 or 2/copper(II) acetylacetonate were formulated. Various amounts of cumene hydroperoxide, acylthiourea and copper(II) acetylacetonate were used. An equimolar cumene hydroperoxide/acylthiourea ratio was selected for each self-cured composite. The reactivity and the final double-bond conversions obtained with these two-component materials was assessed using RT-FTIR spectroscopy. The flexural strength and modulus were measured using a three-point bending setup, after storage of the specimens for 45 min at 37 °C (dry) and for 24 h in water at 37 °C. The working time of each composite was determined using an oscillating rheometer. ResultsAcylthioureas 1 and 2 were synthesized in three to four steps. In combination with cumene hydroperoxide and copper(II) acetylacetonate, both prepared compounds were found to be effective reducing agents. The higher the amount of cumene hydroperoxide and acylthiourea in the self-cured composite, the higher the flexural modulus and the faster the polymerization (lower working times). Similarly, it was shown that increased copper(II) acetylacetonate amounts result in an acceleration of the curing as well as in an improvement of the mechanical properties. The self-cured composite containing 1.25 wt% of cumene hydroperoxide in the monomer mixture of the first paste and 2.00 wt% of acylthiourea 1 in the monomer mixture of the second one provided excellent mechanical properties as well as an optimal working time. SignificancePolymerizable acylthioureas can be used as reducing agents in two-component dental materials. Due to the presence of the methacrylate group, such structures should be efficiently incorporated into the network during polymerization and should not leach out of the composite after curing. As a result, such dental materials are not expected to exhibit bitterness properties.

The physical, chemical, biological and geological properties of Kangal hot spring water and its use in the treatment of psoriasis

: Purpose: In this study, the physical and chemical properties of Kangal fish spa water, which is thought to be effective in the treatment of psoriasis, were evaluated, and the role of the chemical content in the treatment was examined with theoretical calculations. In addition, the role of the fish in the treatment and the role of water in the vital conditions of the fish have been tried to be explained in detail. Material and Methods: Hydrochemical analysis of Kangal hot spring mineral water according to balneological criteria; water temperature, pH value, total mineralization, followed by the presence of macro components i.e. ions, sodium, calcium, magnesium, hydrocarbonates, chlorides, sulfates and finally, iodine, bromine, lithium, fluorine, selenium, strontium, meta silicon and meta boric acid and the presence of microcomponents of carbon dioxide, hydrogen sulfide, nitrogen and oxygen from gases. Results: Average temperature of Kangal hot spring mineral water is 35°C, pH 7.42, dissolved oxygen and free carbon dioxide values are 4.4 and 8.74mg/L, respectively. The total flow rate of the pools was 130 L/s and the radioactivity was determined as 6 eman. Spring water, average electrical conductivity (EC): 530 μS cm-1, CO2 8.70 mg/L, and dissolved oxygen value (DO) 4 mg/L. The electrical conductivity was measured as 530 μS cm-1, and the total mineralization range was 590.9mg/L. Conclusion: As a result of the analyzsis and the values found, it has been shown that spring water with high mineral content and basic has positive effects on the skin. Considering the amount of selenium, copper, calcium, iron, magnesium and zinc in its content, it was concluded that it may have beneficial effects for psoriasis. It was also discovered that according to the Balneological criteria, the mineral waters of Kangal spa met most of the criteria and contained more of the listed therapeutic ingredients.