Low Cr Research Articles

Macroscopic and microscopic element distribution in transition zones of GTAW Alloy 52M weld joint and its PWSCC growth behaviour

The microstructure and element distribution in the transition zone (TZ) of Alloy 52M buttering (52Mb) layer near the fusion boundary to the SA508III low alloy steel in a dissimilar metal weld joint with post-weld heat treatment (PWHT) is characterized. Two macroscopic TZs in the heat-affected zone have lower Cr and Ni contents than the bulk Alloy 52Mb. The first TZ near the fusion boundary has the lowest Cr and Ni compositions, accompanying the highest Fe content. Cr depletion and Ni enrichment along with slight Fe enrichment at the dendrite boundaries in the TZs, are more significant than those in the bulk Alloy 52Mb. The number and the maximum depth of local oxidation penetrations at the alloy-inner oxide interface based on the oxidation tests, the number and the maximum length of locally interdendritic cracks, as well as the average crack growth rate (CGR) in terms of the stress corrosion cracking (SCC) band based on the SCC tests in the first TZ are higher than those in the second TZ. The average SCC CGR is enhanced by macroscopic element dilution, while local oxidation penetration, as well as locally interdendritic SCC, are thought to be enhanced by both the macroscopic dilution of Cr in the TZs and the microscopic Cr depletion at dendrite boundaries.

Impactor identification with spallogenic Cr isotopes: The Wabar impact craters (Saudi Arabia)

AbstractPrecise measurements of Cr isotopic composition of terrestrial impactites have successfully provided evidence for the presence of extraterrestrial material and have, in some cases, allowed the identification of the type of impactor responsible for the formation of the impact structure. The high Cr abundance in most meteorite groups aids in detecting extraterrestrial contamination while their distinct isotopic compositions can help with the identification of the nature of the projectile. However, this common approach of detection and identification of extraterrestrial contamination using mass‐independent 53Cr and 54Cr variations fails when the impactor type is an iron meteorite because of their low Cr abundances (which are in a similar range to terrestrial rocks). The present study demonstrates the viability of a spallogenic Cr contribution in iron meteorites (resulting from their long cosmic ray exposure times), which compensates for their low Cr abundances and facilitates the identification of iron‐meteoritic contamination in terrestrial impactites. Thus, it broadens the scope of impactors (and impactites) that can be investigated using mass‐independent Cr isotopes from solely chondrites and primitive achondrites to include iron meteorites. The Wabar impact craters are an optimal candidate for this study, characterized by low weathering, diverse impactites, partial meteorite survival, substantial impactor material contamination, and a felsic target lithology with low background Cr concentration. The Cr isotopic composition of the Wabar background sand, which represents the target lithology, is indistinguishable from the terrestrial Cr isotopic composition range, whereas the Wabar iron meteorites show coupled spallogenic excesses in ε53Cr and ε54Cr. The Cr isotopic compositions of Wabar impactites show resolved deviations from the terrestrial Cr isotopic composition, thereby indicating the presence of Wabar meteoritic contamination. Moreover, the study demonstrates that even an impactor with a non‐carbonaceous chondritic origin, such as a IIIAB iron meteorite, can have a carbonaceous chondrite‐like signature in ε54Cr anomalies due to spallogenic Cr contamination. The study advocates for a comprehensive investigation combining platinum group elements and Cr (and/or Ni, Ru) isotopes to accurately characterize impactor types.

Effectiveness of setarud (IMOD™) in attenuating gentamicin-induced nephrotoxicity in male rats

BackgroundGentamicin (GEN) can have serious adverse effects including nephrotoxicity. Setarud (IMOD™) is a new herbal drug with beneficial immune effects, obtained by mixing Tanacetum vulgare (tansy), Rosa canina and Urtica dioica (nettle) extracts as well as selenium, flavonoids and carotenes. This novel study aims to evaluate the effectiveness of Setarud (IMOD™) in attenuating GEN-induced nephrotoxicity in male rats. Twenty-eight adult male Sprague Dawley rats (weighing 180–200 g) were randomly divided into four groups (7 rats in each group): Control, IMOD treated (20 mg/kg body weight), GEN treated (100 mg/kg body weight), and GEN + IMOD co-treated. Injections were done intraperitoneally for 12 days. Serum urea, creatinine (Cr), Cr clearance, malondialdehyde (MDA), reduced glutathione (GSH) level, and activities of antioxidant enzymes Peroxidase (POD), Catalase (CAT), and Glutathione peroxidase (GPx) were measured by the colorimetric method. Volume density of proximal convoluted tubule (PCT), tubular necrosis, tubular cast formation, and leukocytic infiltration were evaluated histopathologically.ResultsIn the GEN group, there were significantly higher serum urea, Cr, and MDA levels with lower Cr clearance, GSH levels, POD, GPx and CAT activities, and PCT volume density with presence of tubular necrosis compared to the control and IMOD groups (P < 0.05). Treatment with IMOD significantly reduced the levels of urea, Cr and MDA, and increased Cr clearance and the activities of POD and CAT enzymes (P < 0.05). No significant differences in the activity of GSH and GPx were reported in the GEN + IMOD co-treated group compared to the GEN group. Moreover, IMOD significantly ameliorated PCT volume density and renal lesions caused by GEN.ConclusionIMOD (20 mg/kg body weight) can attenuate GEN-induced nephrotoxicity in rats by inhibition of oxidative stress or increasing the normal activity of antioxidant enzymes. Further studies are recommended on the effects of different doses of IMOD.

Comparison of diffusion coatings resistance on ferritic and austenitic-stainless steels at 650 °C in steam oxidation

Iron-aluminide coatings were deposited on T24, P92 and Incoloy 800HT (IN-800HT) by pack-cementation and by a water-based slurry. According to the differences in heat treatments between the two processes, Al-rich phases, i.e. Fe4Al13 and Fe2Al5 were obtained by pack cementation and only B2-(Fe, Ni)Al by slurry. Vertical or horizontal cracks were present on certain coatings, the former being due to the coefficient of thermal expansion (CTE) mismatch with the substrate while the latter were related to the brittleness of the Al-rich phases. The oxidation behaviour of uncoated and coated substrates was studied at 650 °C up to 1000 h under a low steam flow rate (1.07 × 10−5 m/s). The aluminide coatings were very protective on the low Cr substrates (i.e. T24 and P92) because of the formation of a very thin oxide scale compared to the non-protective thick layers of Fe3O4 and Fe2O3 that grew on both uncoated substrates. In contrast, none of the coatings significantly improved the oxidation resistance of the IN-800HT steel despite the growth of a thin oxide layer made of (Fe, Cr)2O3 and (Fe, Cr)3O4 at 650 °C.

Effects of alloying elements (Mo and W) on corrosion behavior of Ni-based alloys in NaCl-KCl-MgCl2 molten salt

The effects of elements (Mo and W) on the corrosion behavior of some Ni-based alloys (GH3535 and GH3539) with a low Cr content (6–7 wt%) in a NaCl-KCl-MgCl2 molten salt under Ar gas at 800°C were investigated by an immersion test combining with the microstructure analyses. GH3539 alloy suffered more severe corrosion attack than GH3535. The precipitates caused by the alloying elements affects the outward diffusion of Cr. W is more sensitive to corrosion than Mo in the chloride salt, resulting in the worse corrosion resistance of GH3539 compared to GH3535. The interactions among the elements also affect the corrosion.

Analysis of the Oxidation Behavior and Formation of an Extremely Thin Oxide Layer with a Novel Hot-Stamped Steel

This study investigates enhancing the high-temperature oxidation resistance of hot-stamped steels by adding the Cr/Mn/Si elements to form an extremely thin oxide layer. Under low oxygen partial pressure conditions and high Cr content in the matrix, the oxide layer of a 38Cr3MnNbVMo hot-rolled plate containing the Mo element and high Si content was further thinned to 0.6 μm after cooling at 900 °C for 5 min. The structure of the ultra-thin oxide layer consists of Fe3O4, Mn oxides, FeCr2O4, Cr2O3, and Fe2SiO4 oxides. Compared to other antioxidant elements, under low oxygen partial pressure conditions, Si is more prone to oxidation, forming ultra-thin (22 nm) Fe2SiO4 oxides at the matrix interface. Combined with Cr2O3, FeCr2O4, and Mn oxides, it collectively inhibits the mutual diffusion of external O ions and matrix Fe ions. Furthermore, the addition of the Mo element improves the oxidation resistance. The synergistic effect of multiple powerful oxidation-resistant elements and oxide products effectively inhibits the growth of the iron oxide scale, enhancing the oxidation resistance of hot-rolled, hot-stamped steel.

Heavy metal and trace element alterations in patients during a migraine attack.

The aim of the study was to determine the heavy metal and trace element (HMTE) profile in patients with migraine (PwM) and to compare it to that of healthy individuals without migraine. Migraine is a universal disease that affects more than 10% of the world's population; however, its pathophysiology is still obscure. A total of 100 participants were included in this prospective matched case-control study (50 PwM during acute attack and 50 age- and sex-matched healthy controls). The study was conducted in the university hospital in Yozgat, Turkey, where the inductively coupled plasma mass spectrometry system was used to measure the HMTE profile. The calibration curve was created with 11 points for heavy metals (arsenic [As], cadmium [Cd], cobalt [Co], lead [Pb], mercury [Hg], nickel [Ni], and tin [Sn]) and trace elements (antimony [Sb], chromium [Cr], copper [Cu], iron [Fe], magnesium [Mg], manganese [Mn], molybdenum [Mo], and zinc [Zn]). The median age was 27 (23-37) years, and the female/male ratio was 37/13 for both groups. The PwM group had significantly higher As, Co, Pb, and Ni levels among the heavy metals (p = 0.033, 0.017, 0.022, and 0.021, respectively). Also, PwM had significantly lower Cr, Mg, and Zn levels among the trace elements (p = 0.007, 0.024, and < 0.001, respectively). The only trace element that was elevated in the PwM group was Mn (p = 0.001). The PwM and control groups did not differ in terms of Cd, Sn, Sb, Cu, Fe, and Mo (p = 0.165, 0.997, 0.195, 0.408, 0.440, and 0.252, respectively). Some HMTE parameters are altered in PwM, which may provide additional insight into understanding migraine etiology.

Retrospective case-control non-inferiority analysis of ultrasound-guided erector spinae plane block in dogs undergoing mini-hemilaminectomy for intervertebral disc disease.

Veterinary medicine has seen significant advancements in locoregional anaesthesia and pain management, including the emergence of the erector spinae plane (ESP) block. However, limited clinical evidence exists on its efficacy and safety. This study compares ultrasound-guided ESP block (ESP group) with an intraoperative intravenous ketamine infusion analgesic protocol (CRI group) in dogs undergoing thoracolumbar mini-hemilaminectomy, focusing on intraoperative opioid consumption, cardiovascular response to surgical stimulation (CR), postoperative pain scores (PS), and postoperative opioid consumption. Retrospective, case-control, non-inferiority study conducted in a single centre. Data collected included demographics, bupivacaine dose, ESP block operator, intraoperative recorded variables (haemodynamic variables, CR, complications, rescue analgesia), pre- and postoperative analgesia, 24-hour PS and opioid administration, first food intake post-extubation and postoperative complications. Univariate and multiple regression analyses were applied. One-hundred dogs were included, 75 in the ESP group and 25 in the CRI group. Univariate analysis revealed no significant differences between treatment groups in terms of CR, PS, postoperative rescue analgesia, intraoperative and postoperative opioid consumption, or time to first meal intake. However, the multivariate regression analysis indicated that dogs receiving ketamine infusion had higher CR suspected to be nociception-related (p = 0.036), and higher postoperative opioid consumption (p = 0.013). Our study suggests that ultrasound-guided ESP block is as effective as intraoperative ketamine infusion providing perioperative analgesia in dogs undergoing thoracolumbar mini-hemilaminectomy for intervertebral disc disease. ESP group showed significantly lower CR suspected to be nociception-related intraoperatively and lower postoperative opioid consumption within the initial 24 hours.

Banking Performance During the Global Financial Crisis: Empirical Evidence from Bangladesh

Purpose-The Russia-Ukraine conflict and 19 pandemics have severely damaged the world economy. Banking institutions are crucial to the functioning of any economy, and their financial standing is a vital indicator of the economy&amp;apos;s stability. Any major development, be it political or economic, has an impact on the banking industry. The dollar rate&amp;apos;s volatility and other issues hurt the GDP. Therefore, the study examines banking performance in vulnerable global situations before and during the pandemic. This study utilizes 7 years of panel data to analyze global financial crisis banking performance. Design/methodology- Eight ratios were used to compare the banks&amp;apos; profitability, efficiency, liquidity position, and default risk: return on asset, asset utilization ratio, operational efficiency ratio, debt to asset ratio, loan to deposit ratio, loan to asset ratio, credit risk, and bank size. The descriptive statistics show lower ROA and AUR values for banks, but a lower CR value suggests that pandemic-era borrowers will repay their loans on time. Findings – Due to their reliance on borrowed capital, banks may be more vulnerable to default and financial leverage since they lack the liquidity to meet unforeseen requirements for funds. This is indicated by the higher mean values of DAR, LDR, and LAR. Ratio analysis shows that pre-pandemic banks profited well throughout the pandemic. State-owned banks have a worse position in profitability, efficiency, and default risk but a better position in liquidity in both study periods. Conventional banks placed first in profitability, but Islamishariah-based banks placed first in efficiency, high liquidity risk, and low default risk. Originality –This study will help bank officials find the flaw and prevent it from improving financial performance and recovering from the global crisis. This may assist bank investors and depositors in choosing wisely.

Rapidly and simply detecting Cr (VI) in aqueous media via a diketopyrrolopyrrole-based chemosensor with both high selectivity and low LOD

BackgroundThe high toxicity of hexavalent chromium [Cr (VI)] could not only cause harmful effects on humans, including carcinogenicity, respiratory issues, genetic damage, and skin irritation, but also contaminate drinking water sources, aquatic ecosystems, and soil, impairing the reproductive capacity, growth, and survival of organisms. Due to these harmful effects, detecting toxic Cr (VI) is of great significance. However, the rapid, simple, and efficient detection at a low Cr (VI) concentration is extremely challenging, especially in an acidic condition (existing as HCrO4−) due to its low adsorption free energy. ResultsA diketopyrrolopyrrole-based small molecule (DPPT-PhSMe) is designed and characterized to act as a chemosensor, which allows a high selectivity to Cr (VI) at an acidic condition with a low limit of detection to 10−8 M that is two orders of magnitude lower than the cut of limit (1 μM) recommended by World Health Organization (WHO). Mechanism study indicates that the rich sulfur atoms enhance the affinity to HCrO4−. Combining with favorable features of diketopyrrolopyrrole, DPPT-PhSMe not only allows dual-mode detection (colorimetric and spectroscopic) to Cr (VI), but also enables disposable paper-based sensor for naked-eye detection to Cr (VI) from fully aqueous media. The investigation of DPPT-PhSMe chemosensor for the quantification of Cr (VI) in real life samples demonstrates a high reliability and accuracy with an average percentage recovery of 102.1 % ± 4 (n = 3). SignificanceDPPT-PhSMe represents the first diketopyrrolopyrrole-derived chemosensor for efficient detection to toxic Cr (VI), not only providing a targeted solution to the bottleneck of Cr (VI) detection in acidic conditions (existing as HCrO4−) caused by its low adsorption free energy, but also opening a new scenario for simple, selective, and efficient Cr (VI) detection with conjugated dye molecules.

Phase I study of functionally enhanced CD33 CAR T cells in patients with relapsed or refractory acute myeloid leukemia.

6518 Background: Chimeric antigen receptor (CAR) T-cell therapy has shown promising efficacy in B-cell malignancies (Majzner RG, et al. Nat Med. 2019 Sep;25(9):1341-1355). However, its feasibility in acute myeloid leukemia (AML) is not fully established. CD33 CAR T-cell therapy in relapsed or refractory (r/r) AML have reported limited or no significant anti-leukemic effects (Tambaro FP, et al. Leukemia. 2021 Nov;35(11):3282-3286; Wang QS, et al. Mol Ther. 2015 Jan;23(1):184-91). CD123 CAR T-cell therapy has weak proliferation and low CR rates (Wermke M, et al. Blood. 2021 Jun 3;137(22):3145-3148; Cummins, Katherine D. et al. Blood. 2017; 130: 1359), while CLL1 CAR T-cell therapy has induced anti-leukemic responses in a small subset of patients without sustained expansion (Pei K, et al. Cancer Med. 2023 Apr;12(8):9655-9661; Jin X, et al. J Hematol Oncol. 2022 Jul 7;15(1):88). Here, we present early safety and efficacy of functionally enhanced CD33 CAR T cells in AML. Methods: We improved the performance of CD33 CAR T cells by adding a potentiating molecule linked to human CD33 scFv by P2A. The study was registered with ClinicalTrials.gov (NCT04835519). The trial used the “3+3” approach, starting with an initial dose of 5×105 (±20%)/kg. The primary endpoint was safety with efficacy secondary. Results: Four relapsed patients, including three who underwent stem cell transplantation, were enrolled and received initial dose of CAR T cells between April 13, and July 28, 2021. The Data and Safety Monitoring Committee approved the preliminary report. Three patients (75%) experienced grade 1−2 cytokine release syndrome (CRS), while one (25%) had grade 4 CRS. One developed grade 2 CRS after the second infusion. One patient had dose-limiting toxicity. Two patients (50%) had grade 1 neurotoxicity, and two (50%) developed grade 1–2 graft-versus-host disease. All patients experienced grade 2–4 neutropenia, monocytopenia, and thrombocytopenia. One patient developed sepsis. Two patients achieved CR with incomplete hematologic recovery (CRi) and were MRD-negative at day 30, while two had no response. Of these, one patient received a second infusion and achieved MRD+ CRi. Two patients have remained disease free for over two years. One patient remained disease free for one year before CD33+ relapse. The two patients with CRi had peak CAR T cell counts of 192 and 23.5 cells/μl, while the two without CRi had lower peak counts of 2.12 and 10.3 cells/μl. One patient peaked at 1.73 cells/μl after the second infusion. The two patients with CRi also had a higher proportion of CAR T cells among the lymphocytes (46.8% and 53.0%). As expected, peripheral blood CD33+ cells decreased. Conclusions: We report the safety and efficacy of functionally enhanced CD33 CAR T cells. While some patients had CRi, there was also depletion of CD33-positive normal cells. Thus, further research is needed to address the issue of normal cell depletion. Clinical trial information: NCT04835519 .

Compositional evidence for chondrule origins of low‐Ca pyroxenes in comet Wild 2 and a giant cluster IDP

AbstractA literature compilation of 1136 low‐Ca pyroxene compositions from chondrules from 12 primitive type 2–3 carbonaceous, ordinary and enstatite chondrite groups define unique regions on an Al2O3 and Cr2O3 diagram when compared to low‐Ca pyroxenes from equilibrated type 4‐6 chondrites. Measured compositions of 100 low‐Ca pyroxenes from comet Wild 2 and a giant cluster IDP of probable cometary origin are similar to each other and fall in the type 2–3 chondrite chondrule region suggesting that most of the pyroxenes likely formed in the solar nebula like conventional chondrules. The data imply that most low Ca‐pyroxenes from comet Wild 2 and the giant cluster IDP formed from igneous crystallization processes and did not experience significant thermal metamorphism, indicating that the low‐Ca pyroxenes were unlikely incorporated into large parent bodies prior to accretion in their respective comet bodies. An intriguing group of nine low‐Ca pyroxenes from comet Wild 2 with low Cr and Al that fall where type 4–6 chondrites are located are interpreted as products of condensation. The compositional data combined with previously measured oxygen isotopes on 17 low‐Ca pyroxenes support earlier conclusions that comet samples have links with carbonaceous, ordinary, and possibly enstatite chondrite groups. Our results provide additional evidence that comets accreted materials from multiple chondrule reservoirs throughout the solar nebula.

Scalable, acid-resistant polyaniline deposited amidoxime PAN nanofibers for efficient adsorption and detoxification of Cr(VI) wastewater

Chromium (Cr(VI)) metal ions used in industries pose a serious threat to the health of humanity due to the challenge of removal from wastewater and high biotoxicity. Herein, a novel stable and scalable amidoxime modified polyacrylonitrile/polyaniline (AOPAN/PANI) nanofibers membrane (NFM) was prepared via a combined facile electrospinning and interfacial polymerization strategy, and investigated Cr(VI) adsorption performances by batch experiments. The adsorption kinetics, influencing factors, and removal mechanism of Cr(VI) through the scalable AOPAN/PANI NFM was systematically analyzed. The results indicated that the scalable AOPAN/PANI NFM was successfully prepared, and exhibited excellent Cr(VI) absorption capacity (299.56 mg/g), moreover, the prepared NFM exhibits good acid-resistance(pH=2). The pseudo-second-order model conformed to the adsorption kinetics, and the results from batch experiments were matched by the Langmuir adsorption isothermal model. The adsorption of Cr(VI) by the scalable AOPAN/PANI-16 NFM is a non-spontaneous exothermic process. The adsorption mechanism includes electrostatic interaction of Cr(VI) and the scalable AOPAN/PANI NFM, and convert Cr(VI) into low toxicity Cr(III) and chelate. In addition, the scalable AOPAN/PANI nanofibers membrane has good reusable performance. More importantly, this work fully demonstrates the great technical advantages of the industrial application of preparing adsorbent by electrospinning, and provides a novel stable, simple and efficient treatment method for the detoxification treatment of Cr(VI) in acid wastewater.

Ultra-high capacity and anti-interference for Cr(VI) removal by tannin-polyvinylimine modified graphite carbon nitride

To combat the increasingly serious water pollution caused by heavy metal ions, the development of efficient adsorbents is of great significance. In this study, a novel composite adsorbent for Cr(VI) removal was smartly designed using environmentally friendly materials such as tannic acid (TA) and polyethyleneimine (PEI) for surface modification of g-C3N4 nanosheets through covalent assembly of polyphenols and amines. The obtained (PEI-TA)-g-C3N4 composite was capable of efficiently and quickly adsorbing Cr(VI) in water, with a maximum adsorption capacity of 769.23 mg/g at 308 K (35 °C), which was much higher than most reported Cr(VI) adsorbents. Notably, (PEI-TA)-g-C3N4 could reduce highly toxic Cr(VI) to low toxic Cr(III) and effectively adsorb it. The Cr(VI) adsorption process was a spontaneous thermal adsorption process that conformed to the pseudo-second-order kinetic model and Langmuir isotherm model. In addition, the excellent photothermal performance of (PEI-TA)-g-C3N4 further accelerated the adsorption of Cr(VI). Moreover, the strong anti-interference ability of (PEI-TA)-g-C3N4 composite against anions and other metal ions enabled it to effectively remove Cr(VI) in complex environments, expanding its practical application scenarios. The polymer coatings rich in phenolic hydroxyl- and amine-rich formed on the large surface area of g-C3N4 and the protonation of the amino groups are the keys for (PEI-TA)-g-C3N4 composite to have ultra-high adsorption performance and strong anti-interference ability towards Cr(VI). The designed strategy of this metal-free and environmentally friendly composite with ultra-high removal of Cr(VI) capability from wastewater provides new ideas for developing green, inexpensive, and efficient adsorbents.

Corrosion Behavior of Ni-Cr Alloys with Different Cr Contents in NaCl-KCl-MgCl2.

This study investigates the corrosion behavior of Ni-Cr binary alloys, including Ni-10Cr, Ni-15Cr, Ni-20Cr, Ni-25Cr, and Ni-30Cr, in a NaCl-KCl-MgCl2 molten salt mixture through gravimetric analysis. Corrosion tests were conducted at 700 °C, with the maximum immersion time reaching up to 100 h. The corrosion rate was determined by measuring the mass loss of the specimens at various time intervals. Verifying corrosion rates by combining mass loss results with the determination of element dissolution in molten salts using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Detailed examinations of the corrosion products and morphology were conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Micro-area elemental analysis on the corroded surfaces was performed using an energy dispersive spectrometer (EDS), and the elemental distribution across the corrosion cross-sections was mapped. The results indicate that alloys with lower Cr content exhibit superior corrosion resistance in the NaCl-KCl-MgCl2 molten salt under an argon atmosphere compared to those with higher Cr content; no corrosion products were retained on the surfaces of the lower Cr alloys (Ni-10Cr, Ni-15Cr). For the higher Cr alloys (Ni-20Cr, Ni-25Cr, Ni-30Cr), after 20 h of corrosion, a protective layer was observed in certain areas. The formation of a stable Cr2O3 layer in the initial stages of corrosion for high-Cr content alloys, which reacts with MgO in the molten salt to form a stable MgCr2O4 spinel structure, provides additional protection for the alloys. However, over time, even under argon protection, the MgCr2O4 protective layer gradually degrades due to chloride ion infiltration and chemical reactions at high temperatures. Further analysis revealed that chloride ions play a pivotal role in the corrosion process, not only facilitating the destruction of the Cr2O3 layer on the alloy surfaces but also possibly accelerating the corrosion of the metallic matrix through electrochemical reactions. In conclusion, the corrosion behavior of Ni-Cr alloys in the NaCl-KCl-MgCl2 molten salt environment is influenced by a combination of factors, including Cr content, chloride ion activity, and the formation and degradation of protective layers. This study not only provides new insights into the corrosion resistance of Ni-Cr alloys in high-temperature molten salt environments but also offers significant theoretical support for the design and optimization of corrosion-resistant alloy materials.

An innovative ionic liquid-aqueous biphasic system for simultaneously highly efficient dechroming and collagen recovery from chrome-tanned leather shavings at room temperature

Chrome-tanned leather shavings (CTLS) with abundant collagen of 70–90 wt% but high Cr content of 2–4 wt% are considered as hazardous wastes. Due to the stable covalent bond between Cr and collagen, current processes for collagen recovery from CTLS face challenges including low dechroming efficiency, collagen disruption, high energy and chemical consumption and secondary pollution. In this paper, an innovative IL-targeted homogeneous isolation (IL-THI) process based on the reusable ionic liquid-aqueous biphasic system (IL-ABS) was established for the simultaneous resource recovery and complete dechroming of CTLS at room temperature, with the recovery rate of collagen reached 72.4 % while Cr content in collagen is reduced from 35.65 × 103 mg/kg to 1.78 mg/kg. This IL-ABS enriched TBAH in the upper phase and potassium tartrate in the lower phase. Moreover, TBAH demonstrated excellent reproducibility across five cycles, achieving consistently low Cr content of 2.65 mg/kg in collagen, far below the 50 mg/kg limit in national standards. The triple helix conformation and the molecular weight of the collagen product were confirmed via Fourier-transform infrared spectroscopy, X-ray diffraction analyses, circular dichroism spectra analysis and SDS-PAGE. Moreover, economic calculations demonstrated the suitability of this novel process for sustainable CTLS recovery. The superior dechroming ability of IL-ABS is attributed to the formation of Cr(III)-Tartrate complexes, which preferentially migrate to the lower phase due to the solvophobic effect, while dissolved collagen is recovered from the upper phase, as disclosed by UV–Vis spectra, ICP-OES, and all-atom molecular dynamics simulations. Additionally, IL-THI process demonstrates considerable potential for the isolation of Cr(III) and collagen in solid waste, with low energy consumption, improved separation efficiency, and increased design flexibility.

Risk assessment of trace elements in vegetables grown in river Yamuna floodplain in Delhi.

Urban agriculture is common in fertile river floodplains of many developing countries. However, there is a risk of contamination in highly polluted regions. This study quantifies health risks associated with the consumption of vegetables grown in the floodplain of the urban river 'Yamuna' in the highly polluted yet data-scarce megacity Delhi, India. Six trace elements are analyzed in five kinds of vegetable samples. Soil samples from the cultivation area are also analyzed for elemental contamination. Ni, Mn, and Co are observed to be higher in leafy vegetables than others. Fruit and inflorescence vegetables are found to have higher concentrations of Cr, Pb, and Zn as compared to root vegetables. Transfer Factor indicates that Cr and Co have the highest and least mobility, respectively. Vegetable Pollution Index indicates that contamination levels follow as Cr > Ni > Pb > Zn. Higher Metal Pollution Index of leafy and inflorescence vegetables than root and fruit vegetables indicate that atmospheric deposition is the predominant source. Principal Component Analysis indicates that Pb and Cr have similar sources and patterns in accumulation. Among the analyzed vegetables, radish may pose a non-carcinogenic risk to the age group of 1-5year. Carcinogenic risk is found to be potentially high due to Ni and Cr accumulation. Consumption of leafy vegetables was found to have relatively less risk than other vegetables due to lower Cr accumulation. Remediation of Cr and Ni in floodplain soil and regular monitoring of elemental contamination is a priority.

Can competitive effects and responses of alien and native species predict invasion outcomes?

The relative competitive ability of native and alien species, which consists of competitive effect (CE) and response (CR), has often been invoked as a key determinant of invasion success. Previous studies have reported that an alien species with a high CE and/or a low CR would successfully invade a native species. However, no studies have yet empirically examined the hypothesis or tested the consistency of invasion outcomes predicted by the CE-CR framework and modern species coexistence theory (MCT). To fill this research gap, we conducted a pairwise competition experiment between five alien and five native species, quantified CE and CR based on their biomass in the absence and presence of one competitor, and predicted invasion outcomes based on both CE-CR and MCT frameworks. We have demonstrated theoretically that the CE and CR frequently measured in previous work are only approximations of interspecific competitive coefficients, and thus could not completely predict the invasion outcomes. As we expected, the invasion outcomes predicted by the CE-CR framework were partially consistent with the predictions by the MCT framework. Specifically, aliens with low CR and high CE tended to exclude natives, while aliens with high CR and low CE tended to be excluded by natives according to MCT. In contrast, pairs of stable coexistence and priority effects did not conform to the theoretical expectation. Despite the theoretical defects of the CE-CR framework, it can provide some useful value in predicting the invasion outcomes, especially when intrinsic growth rate and intraspecific competition coefficients are not available. Our study is the first to compare invasion outcomes separately derived from qualitative (the CE-CR framework) and quantitative (the MCT framework) methods. We recommend that future research should adopt quantitative approaches such as MCT as far as possible, to more comprehensively understand and predict the biotic outcomes of interacting species.

Petrology and Geochemistry of the Ultramafic Rocks of Yerrabali Schist Belt, Eastern Dharwar Craton, Telangana, India

Abstract The Yerrabali schist Belt (YSB) is a NW–SE trending 10 km long and 4 km wide belt located at the north eastern corner of Eastern Dharwar Craton (EDC) consisting of Banded Magnetite Quartzite (BMQ), ultramafic rocks, quartz–cordierite– gedrite ± garnet bearing schist, sillimanite–garnet–cordierite schist, metadolomite, amphibolite, ferruginous quartzite, tremolite schist and dolerite dyke. The ultramafic rocks consist of olivine, orthopyroxene, clinopyroxene and spinel. The Fe content of olivine varies from 88-91 and consists of high amount of NiO (0.3-0.511%). Orthopyroxone are enstatitic and clinopyroxene are Mg-augite in nature. The spinel grains are rich in Al2O3 (48.32-59.09%) and show very low Cr# values (0.08-0.29). Thermo-barometric analyses show equilibrium condition of 700°-1100°C temperature and 19-21 kb pressure. Oxygen fugacity of the ultramafic rocks range from -0.035 to -1.356 log units below FMQ buffer. Low Cr# values of spinel along with low oxygen fugacity suggest their formation by low degrees of partial melting from a less refractory Mid Oceanic Ridge (MOR) type mantle.

Petrogenesis of Late Triassic adakitic plutons in the East Kunlun Orogen, Northern Tibet: Geodynamic implications for the Paleo-Tethyan orogeny and crustal evolution

Adakitic rocks found within continental arcs are pivotal in unraveling the geodynamic processes and tectonic evolution of East Kunlun Paleo-Tethyan orogen. We present an integrated study on the petrography, zircon U-Pb geochronology, whole-rock geochemistry, and Sr-Nd-Hf isotopes of newly identified Late Triassic adakitic plutons in the East Kunlun Orogenic Belt (EKOB), Northern Tibet, aiming to constrain their petrogenesis and geodynamic implications. These plutons comprise by mylonitized granite, monzogranite, granodiorite and dioritic porphyrite, exhibiting consistent zircon U-Pb ages of approximately 204–212 Ma. They have high SiO2, K2O and Sr (average of 479 ppm) contents, but low contents of Y (5.6–18 ppm) and Yb (0.5–1.0 ppm) with high Sr/Y ratios (17–63), resembling adakitic rocks. These adakitic rocks can be classified into high-Mg (Mg#= ∼51) and low-Mg groups (Mg#= ∼35), although they all display enriched large ion lithophile elements and light rare earth elements but depleted high field strength elements. The studied low-Mg adakitic rocks have low MgO (∼0.68 wt%) and Cr (∼35 ppm) with enriched zircon Hf isotopes (εHf(t) = − 1.16 t 2.44), suggesting their derivation by partial melting of thickened juvenile crust. Conversely, the high-Mg adakitic rocks exhibit high MgO (∼1.94 wt%) and Cr (∼61 ppm) with relatively high zircon εHf(t) values (−0.68 to 4.95), indicating their derivation from foundered crustal root with subsequent interaction with enriched mantle-derived magma. Tectonic reconstructions suggest that the formation of these Late Triassic adakitic rocks occurred in a post-collisional extension setting and the East Kunlun Paleo-Tethyan Ocean closed no later than Norian.