The exact annihilating-ideal graph of a commutative ring

The rings considered in this article are commutative with identity. For an ideal $I$ of a ring $R$, we denote the annihilator of $I$ in $R$ by $Ann(I)$. An ideal $I$ of a ring $R$ is said to be an exact annihilating ideal if there exists a non-zero ideal $J$ of $R$ such that $Ann(I) = J$ and $Ann(J) = I$. For a ring $R$, we denote the set of all exact annihilating ideals of $R$ by $\mathbb{EA}(R)$ and $\mathbb{EA}(R)\backslash \{(0)\}$ by $\mathbb{EA}(R)^{*}$. Let $R$ be a ring such that $\mathbb{EA}(R)^{*}\neq \emptyset$. With $R$, in [Exact Annihilating-ideal graph of commutative rings, {\it J. Algebra and Related Topics} {\bf 5}(1) (2017) 27-33] P.T. Lalchandani introduced and investigated an undirected graph called the exact annihilating-ideal graph of $R$, denoted by $\mathbb{EAG}(R)$ whose vertex set is $\mathbb{EA}(R)^{*}$ and distinct vertices $I$ and $J$ are adjacent if and only if $Ann(I) = J$ and $Ann(J) = I$. In this article, we continue the study of the exact annihilating-ideal graph of a ring. In Section 2 , we prove some basic properties of exact annihilating ideals of a commutative ring and we provide several examples. In Section 3, we determine the structure of $\mathbb{EAG}(R)$, where either $R$ is a special principal ideal ring or $R$ is a reduced ring which admits only a finite number of minimal prime ideals

Engineering of activated carbon surface to enhance the catalytic activity of supported cobalt oxide nanoparticles in peroxymonosulfate activation

[EN] Commercial activated carbon has been functionalized by chemical or thermal treatments to introduce surface oxygen functional groups able to anchor small cobalt nanoparticles with superior catalytic activity for peroxymonosulfate activation. The resulting activated carbon supports where characterized by combustion elemental analysis, Fourier-transformed infrared spectroscopy, Raman spectroscopy, isothermal N-2 adsorption, temperature programmed desorption/mass spectrometry, X-ray diffraction and scanning electron microscopy. Activated carbon functionalization by nitric acid resulted the most appropriated method to provide a higher population of oxygenated functional groups able to anchor small cobalt nanoparticles. The catalytic activity of supported oxidized metal nanoparticles (4.7 +/- 0.05 nm) was higher than analogous non-oxidized cobalt nanoparticles (2.9 +/- 0.14 nm). The use of analogous supported oxidized iron or copper nanoparticles resulted in lower catalytic activity. Importantly, the supported oxidized cobalt nanoparticles at 0.2 wt% loading exhibit higher activity than benchmark catalysts such as unsupported Co3O4 solid or even homogeneous Co2+ ions. This is a reflection of the relatively low estimated activation energy for both processes, peroxymonosulfate decomposition and phenol degradation. The estimated activation energy values are about 30 and 32 kJ mol(-1). The stability of the most active catalyst was assessed by performing eight consecutive uses without observing decrease of catalytic activity, neither metal leaching or metal nanoparticle aggregation. Turnover numbers/turnover frequencies values as high as 440(5)/8.10(5)h(-1) for peroxymonosulfate activation and 39.10(3)/68.10(3) h(-1) for phenol degradation at pH 7 and 20 degrees C have been estimated, respectively. Electron paramagnetic resonance measurements and selective quenching experiments revealed that the generated sulfate radicals from peroxymonosulfate rapidly are transformed in highly reactive hydroxyl radicals. In excellent agreement with previous reports, this work demonstrates the importance of an adequate activated carbon functionalization to obtain superior and stable catalysts for peroxymonosulfate activation.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa, CTQ2015-65963-CQ-R1) and CTQ2014-53292-R is gratefully acknowledged. Generalitat Valenciana is also thanked for funding (Prometeo 2017/083). S.N. thanks financial support by the Fundacion Ramon Areces (XVIII Concurso Nacional para la Adjudicacion de Ayudas a la Investigacion en Ciencias de la Vida y de la Materia, 2016).Espinosa-López, JC.; Manickam-Periyaraman, P.; Bernat-Quesada, F.; Sivanesan, S.; Alvaro Rodríguez, MM.; García Gómez, H.; Navalón Oltra, S. (2019). Engineering of activated carbon surface to enhance the catalytic activity of supported cobalt oxide nanoparticles in peroxymonosulfate activation. Applied Catalysis B Environmental. 249:42-53. https://doi.org/10.1016/j.apcatb.2019.02.043S425324

Bimetallic iron-copper oxide nanoparticles supported on nanometric diamond as efficient and stable sunlight-assisted Fenton photocatalyst

[EN] Bimetallic iron and copper oxide nanoparticles (NPs) supported on hydroxylated diamond (D3) exhibits an improved activity for the heterogeneous Fenton phenol degradation under natural or simulated sunlight irradiation with respect to analogous monometallic samples or than analogous FeCu NPs on graphite, activated carbon and P25 TiO2 semiconductor. FeCu/D3 catalyst exhibits good recyclability and stability especially working at pH 6. Overall, the high activity of the Fe20Cu80(0.2 wt%)/D3 catalyst is mainly due to the combination of the high activity of reduced copper species decomposing H2O2 to HO center dot radical, while Fe2+ allows the regeneration of these reduced copper species.S.N. thanks financial support by the Fundacion Ramon Areces (XVIII Concurso Nacional para la Adjudicacion de Ayudas a la Investigacion en Ciencias de la Vida y de la Materia, 2016), Ministerio de Ciencia, Innovacion y Universidades RTI2018-099482-A-I00 project and Generalitat Valenciana grupos de investigacion consolidables 2019 (ref: AICO/2019/214) project. H.G. thanks financial support by the Spanish Ministry of Science and Innovation (Severo Ochoa SEV2016 and RTI2018-890237-CO2-1) and Generalitat Valenciana (Prometeo 2017/083) is also gratefully acknowledged.Manickam-Periyaraman, P.; Espinosa, JC.; Ferrer Ribera, RB.; Subramanian, S.; Alvaro Rodríguez, MM.; García Gómez, H.; Navalón Oltra, S. (2020). Bimetallic iron-copper oxide nanoparticles supported on nanometric diamond as efficient and stable sunlight-assisted Fenton photocatalyst. Chemical Engineering Journal. 393:1-11. https://doi.org/10.1016/j.cej.2020.124770S111393Malato, S., Fernández-Ibáñez, P., Maldonado, M. I., Blanco, J., & Gernjak, W. (2009). Decontamination and disinfection of water by solar photocatalysis: Recent overview and trends. Catalysis Today, 147(1), 1-59. doi:10.1016/j.cattod.2009.06.018Pera-Titus, M., Garcı́a-Molina, V., Baños, M. A., Giménez, J., & Esplugas, S. (2004). Degradation of chlorophenols by means of advanced oxidation processes: a general review. Applied Catalysis B: Environmental, 47(4), 219-256. doi:10.1016/j.apcatb.2003.09.010Pignatello, J. J., Oliveros, E., & MacKay, A. (2006). Advanced Oxidation Processes for Organic Contaminant Destruction Based on the Fenton Reaction and Related Chemistry. Critical Reviews in Environmental Science and Technology, 36(1), 1-84. doi:10.1080/10643380500326564Rahim Pouran, S., Abdul Aziz, A. R., & Wan Daud, W. M. A. (2015). Review on the main advances in photo-Fenton oxidation system for recalcitrant wastewaters. Journal of Industrial and Engineering Chemistry, 21, 53-69. doi:10.1016/j.jiec.2014.05.005Cheng, M., Zeng, G., Huang, D., Lai, C., Xu, P., Zhang, C., & Liu, Y. (2016). Hydroxyl radicals based advanced oxidation processes (AOPs) for remediation of soils contaminated with organic compounds: A review. Chemical Engineering Journal, 284, 582-598. doi:10.1016/j.cej.2015.09.001Garrido-Ramírez, E. G., Theng, B. K. ., & Mora, M. L. (2010). Clays and oxide minerals as catalysts and nanocatalysts in Fenton-like reactions — A review. Applied Clay Science, 47(3-4), 182-192. doi:10.1016/j.clay.2009.11.044Klavarioti, M., Mantzavinos, D., & Kassinos, D. (2009). Removal of residual pharmaceuticals from aqueous systems by advanced oxidation processes. Environment International, 35(2), 402-417. doi:10.1016/j.envint.2008.07.009Bokare, A. D., & Choi, W. (2014). Review of iron-free Fenton-like systems for activating H2O2 in advanced oxidation processes. Journal of Hazardous Materials, 275, 121-135. doi:10.1016/j.jhazmat.2014.04.054Chiron, S. (2000). Pesticide chemical oxidation: state-of-the-art. Water Research, 34(2), 366-377. doi:10.1016/s0043-1354(99)00173-6Chong, M. N., Jin, B., Chow, C. W. K., & Saint, C. (2010). Recent developments in photocatalytic water treatment technology: A review. Water Research, 44(10), 2997-3027. doi:10.1016/j.watres.2010.02.039Herney-Ramirez, J., Vicente, M. A., & Madeira, L. M. (2010). Heterogeneous photo-Fenton oxidation with pillared clay-based catalysts for wastewater treatment: A review. Applied Catalysis B: Environmental, 98(1-2), 10-26. doi:10.1016/j.apcatb.2010.05.004Wang, C., Liu, H., & Sun, Z. (2012). Heterogeneous Photo-Fenton Reaction Catalyzed by Nanosized Iron Oxides for Water Treatment. International Journal of Photoenergy, 2012, 1-10. doi:10.1155/2012/801694Ramirez, J. H., Maldonado-Hódar, F. J., Pérez-Cadenas, A. F., Moreno-Castilla, C., Costa, C. A., & Madeira, L. M. (2007). Azo-dye Orange II degradation by heterogeneous Fenton-like reaction using carbon-Fe catalysts. Applied Catalysis B: Environmental, 75(3-4), 312-323. doi:10.1016/j.apcatb.2007.05.003Navalon, S., Sempere, D., Alvaro, M., & Garcia, H. (2013). Influence of Hydrogen Annealing on the Photocatalytic Activity of Diamond-Supported Gold Catalysts. ACS Applied Materials & Interfaces, 5(15), 7160-7169. doi:10.1021/am401489nEspinosa, J. C., Navalón, S., Álvaro, M., & García, H. (2015). Silver Nanoparticles Supported on Diamond Nanoparticles as a Highly Efficient Photocatalyst for the Fenton Reaction under Natural Sunlight Irradiation. ChemCatChem, 7(17), 2682-2688. doi:10.1002/cctc.201500458Espinosa, J. C., Navalón, S., Álvaro, M., & García, H. (2016). Copper nanoparticles supported on diamond nanoparticles as a cost-effective and efficient catalyst for natural sunlight assisted Fenton reaction. Catalysis Science & Technology, 6(19), 7077-7085. doi:10.1039/c6cy00572aEspinosa, J. C., Catalá, C., Navalón, S., Ferrer, B., Álvaro, M., & García, H. (2018). Iron oxide nanoparticles supported on diamond nanoparticles as efficient and stable catalyst for the visible light assisted Fenton reaction. Applied Catalysis B: Environmental, 226, 242-251. doi:10.1016/j.apcatb.2017.12.060Garrido-Ramírez, E. G., Marco, J. F., Escalona, N., & Ureta-Zañartu, M. S. (2016). Preparation and characterization of bimetallic Fe–Cu allophane nanoclays and their activity in the phenol oxidation by heterogeneous electro-Fenton reaction. Microporous and Mesoporous Materials, 225, 303-311. doi:10.1016/j.micromeso.2016.01.013Karthikeyan, S., Pachamuthu, M. P., Isaacs, M. A., Kumar, S., Lee, A. F., & Sekaran, G. (2016). Cu and Fe oxides dispersed on SBA-15: A Fenton type bimetallic catalyst for N,N -diethyl- p -phenyl diamine degradation. Applied Catalysis B: Environmental, 199, 323-330. doi:10.1016/j.apcatb.2016.06.040Martin, R., Navalon, S., Delgado, J. J., Calvino, J. J., Alvaro, M., & Garcia, H. (2011). Influence of the Preparation Procedure on the Catalytic Activity of Gold Supported on Diamond Nanoparticles for Phenol Peroxidation. Chemistry - A European Journal, 17(34), 9494-9502. doi:10.1002/chem.201100955Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption.Dhakshinamoorthy, A., Navalon, S., Alvaro, M., & Garcia, H. (2012). Metal Nanoparticles as Heterogeneous Fenton Catalysts. ChemSusChem, 5(1), 46-64. doi:10.1002/cssc.201100517Burkitt, M. J., & Mason, R. P. (1991). Direct evidence for in vivo hydroxyl-radical generation in experimental iron overload: an ESR spin-trapping investigation. Proceedings of the National Academy of Sciences, 88(19), 8440-8444. doi:10.1073/pnas.88.19.8440Li, K., Zhao, Y., Janik, M. J., Song, C., & Guo, X. (2017). Facile preparation of magnetic mesoporous Fe3O4/C/Cu composites as high performance Fenton-like catalysts. Applied Surface Science, 396, 1383-1392. doi:10.1016/j.apsusc.2016.11.17

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

The exact annihilating-ideal graph of a commutative ring

The rings considered in this article are commutative with identity. For an ideal $I$ of a ring $R$, we denote the annihilator of $I$ in $R$ by $Ann(I)$. An ideal $I$ of a ring $R$ is said to be an exact annihilating ideal if there exists a non-zero ideal $J$ of $R$ such that $Ann(I) = J$ and $Ann(J) = I$. For a ring $R$, we denote the set of all exact annihilating ideals of $R$ by $\mathbb{EA}(R)$ and $\mathbb{EA}(R)\backslash \{(0)\}$ by $\mathbb{EA}(R)^{*}$. Let $R$ be a ring such that $\mathbb{EA}(R)^{*}\neq \emptyset$. With $R$, in [Exact Annihilating-ideal graph of commutative rings, {\it J. Algebra and Related Topics} {\bf 5}(1) (2017) 27-33] P.T. Lalchandani introduced and investigated an undirected graph called the exact annihilating-ideal graph of $R$, denoted by $\mathbb{EAG}(R)$ whose vertex set is $\mathbb{EA}(R)^{*}$ and distinct vertices $I$ and $J$ are adjacent if and only if $Ann(I) = J$ and $Ann(J) = I$. In this article, we continue the study of the exact annihilating-ideal graph of a ring. In Section 2 , we prove some basic properties of exact annihilating ideals of a commutative ring and we provide several examples. In Section 3, we determine the structure of $\mathbb{EAG}(R)$, where either $R$ is a special principal ideal ring or $R$ is a reduced ring which admits only a finite number of minimal prime ideals

Multiphasic inhibition of mild steel corrosion in H2S gas environment

Compounds like Octylpalmamide (OTP), Octylsteramide (OTS), Octylcaprylamide (OTC), Octylbenzamide (OTB) and one complex compound Dicyclohexylaminebenzotriazole (DCHAB) were synthesized and characterized by Fourier Transform infrared spectroscopy (FTIR). These synthesized compounds were drawn as volatile corrosion inhibitor (VCI) in H2S gas environment on mild steel (MS) at 323 K. Surface morphology and elemental analysis have been examined by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) respectively. Various studies like weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used for evaluating corrosion rate, inhibitor behaviour and change in charge transfer resistance (Rct) value, respectively. All the above experiments proved that DCHAB was the most efficacious corrosion inhibitor. Adsorption behaviour of the inhibitor was evaluated and it obeys Langmuir adsorption isotherm

Graphite with fullerene and filamentous carbon structures formed from iron melt as a lithium-intercalating anode

The electrochemical properties of flaky graphite containing carbon nanostructures, synthesized by a dissolution-precipitation method from a carbon-rich cast iron melt, were investigated. The formation of the highly crystalline graphite was realized at temperatures as low as 1600 jC. The presence of fullerenes and filamentous carbon structures on the graphite was confirmed by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. The reversible lithium intercalation capacity of the graphitic product was more than 300 mAh/g. The first-cycle irreversible capacity was a mere 14%. The coulombic efficiency seemed to stabilize at values >99% from the fifth cycle

Evaluation of Microstructural and Mechanical Behaviours of Tempered 2.25Cr-1Mo Steel Through Electromagnetic Characterization

The effect of tempering treatment has been investigated on water quenched P22 steel with the chemical composition of 0.13C, 0.24Si, 0.47Mn, 0.012P, 0.005S, 2.19Cr, 0.93Mo and balance Fe (all in wt%) within the temperature ranges of 650–900 °C. The microstructural, mechanical and magnetic properties of as-quenched and tempered steels have been investigated through optical and scanning electron microscopy, hardness and universal tensile testing, electromagnetic sensor (Magstar), respectively. The water quenched sample consists of fine martensitic structure with a hardness of 381 HV. With the progress of tempering, the martensite becomes coarse till 800 °C, decreasing the hardness of steel samples. The tempering at 700 °C results in martensite coarsening and precipitation of rod and globular shaped carbides; while a fraction of globular carbide is observed to increase in the matrix after 750 °C of tempering. Beyond 800 °C, the ferrite and bainite phases gradually form by replacing martensite, and the ferrite structure is prevalent after 900 °C. Due to microstructural changes, the magnetic properties are also affected as a function of tempering temperature. The coarsening of martensite causes the decrease in coercivity with increasing tempering temperature, leading to magnetic softening

Estimation of magnesium in patients with functional hypoparathyroidism

Context: It is evident that about 30-50% of patients with Vitamin D deficiency (VDD) do not manifest develop secondary hyperparathyroidism (SHPT). A number of theories have been proposed to explain this lack of SHPT, including hypomagnesemia. Settings and Design: Retrospective review of laboratory database. Materials and Methods: We evaluated the differences in serum magnesium (Mg) levels among those with VDD with or without SHPT. A retrospective review of 6255 laboratory data of bone mineral profiles performed in the period of 2007-2013. After excluding patients with hypercalcemia, renal dysfunction/unknown kidney function and primary hypothyroidism, the remaining 1323 patient data were analyzed. SHPT was defined as serum parathyroid hormone >65 in those with VDD. Statistical Analysis Used: ANOVA and Wilcoxon tests as appropriate to compare means. Multivariate logistic regression to analyze relation between variables and outcome of SHPT. Results: We noted that 55% patients (n = 727) had VDD, and among those who had VDD, 23% (n = 170) were hypocalcemic (corrected serum calcium <8.5). Patients with VDD who did not exhibit SHPT were 56% (n = 407). The mean (±standard deviation) serum Mg levels in the entire cohort (n = 1323) was 1.94 ± 0.26 mg/dl and 1.95 ± 0.26 mg/dl in VDD cohort and 2 ± 0.31 mg/dl in the VDD-hypocalcemic cohort. There was no statistical difference in the Mg levels among those with SHPT compared to those without SHPT (P = 0.14). Serum calcium and phosphorus were lower in those with SHPT (P = 0.06 and P < 0.001, respectively). In multivariate logistic regression, serum calcium (P = 0.043), phosphorus (P < 0.001) and severe VDD (P < 0.001) independently correlated with occurrence of SHPT in VDD. Conclusions: Serum Mg levels did not explain the functional hypoparathyroidism seen in about half of the patients with VDD. A low normal serum calcium and phosphorus levels are more likely to be associated with VDD patients who develop SHPT

Synthesis, Characterization and Application of SnO₂@rGO Nanocomposite for Selective Catalytic Reduction of Exhaust Emission in Internal Combustion Engines

In this experimental investigation, a procreation approach was used to produce a catalyst based on SnO2@rGO nanocomposite for use in a selective catalytic reduction (SCR) system. Plastic waste oil is one such alternative that helps to ensure the survival of fossil fuels and also lessens the negative impacts of improper waste disposal. The SnO2@rGO nanocomposite was prepared by fine dispersion of SnO2 nanoparticles on monolayer-dispersed reduced graphene oxide (rGO) and carefully investigated for its potential in adsorbing CO, CO2, NOX, and hydrocarbon (HC). The as-synthesized SnO2@rGO nanocomposite was characterized by Fourier transform infrared spectroscopy, high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction spectroscopy, thermogravimetry, and surface area analyses. Then, the impact of catalysts inside the exhaust engine system was evaluated in a realistic setting with a single-cylinder, direct-injection diesel engine. As a result, the catalysts reduced harmful pollution emissions while marginally increasing brake-specific fuel consumption. The nanocomposite was shown to exhibit higher NOX adsorption efficiencies when working with different toxic gases. Maximum reductions in the emission of NOX, hydrocarbons, and CO were achieved at a rate of 78%, 62%, and 15%, respectively. These harmful pollutants were adsorbed on the active sites of catalyst and are converted to useful fuel gases through catalytic reduction thereby hindering the trajectory of global warming