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Despite the advances in the field of carbon‐halogen bond formation, the straightforward catalytic access to selectively functionalized iodoaryls remains a challenge. Here, we report a one‐pot synthesis of ortho‐iodobiaryls from aryl iodides and bromides by palladium/norbornene catalysis. This new example of Catellani reaction features the initial cleavage of a C(sp2)−I bond, followed by the key formation of a palladacycle through ortho C−H activation, the oxidative addition of an aryl bromide and the ultimate restoration of the C(sp2)−I bond. A large variety of valuable o‐iodobiaryls has been synthesized in satisfactory to good yields and their derivatization have been described too. Beyond the synthetic utility of this transformation, a DFT study provides insights on the mechanism of the key reductive elimination step, which is driven by an original transmetallation between palladium(II)‐halides complexes. [ABSTRACT FROM AUTHOR]

Despite the advances in the field of carbon‐halogen bond formation, the straightforward catalytic access to selectively functionalized iodoaryls remains a challenge. Here, we report a one‐pot synthesis of ortho‐iodobiaryls from aryl iodides and bromides by palladium/norbornene catalysis. This new example of Catellani reaction features the initial cleavage of a C(sp2)−I bond, followed by the key formation of a palladacycle through ortho C−H activation, the oxidative addition of an aryl bromide and the ultimate restoration of the C(sp2)−I bond. A large variety of valuable o‐iodobiaryls has been synthesized in satisfactory to good yields and their derivatization have been described too. Beyond the synthetic utility of this transformation, a DFT study provides insights on the mechanism of the key reductive elimination step, which is driven by an original transmetallation between palladium(II)‐halides complexes. [ABSTRACT FROM AUTHOR]

The composition of the catalyst layer plays an important role in the carbon dioxide reduction reaction (CO 2 RR), since it influences greatly the mass diffusion rate and the accessibility of active sites. Until now, tremendous efforts have been dedicated to the development of cathode materials with innovative characteristics, while scarce efforts have been concentrated on the study of the catalyst layer aiming at maximizing the performance of the electrodes toward the CO 2 RR. This work focuses on a full investigation of the key electrode components and their effects on the CO 2 RR performance. It is found that all key components such as Nafion binder, zinc oxide catalyst and carbon black conductor significantly affect the current density and the faradaic efficiency for carbon monoxide (CO) formation. [Display omitted] • A thorough study of the composition of a ZnO-based electrode is conducted for CO 2 RR. • All key components show significant effects on CO selectivity and production rate. • Nafion favors charge transfer while it limits electron transport and CO 2 diffusion. • Carbon black considerably increases electrical conductivity. • ZnO loading is associated with the number of active sites and their accessibility. [ABSTRACT FROM AUTHOR]

The synthesis of novel catalysts for the oxygen reduction reaction, by means of a fast one-pot microwave-assisted procedure, is reported herein and deeply explained. In particular, the important role of doping atoms, like sulfur and nitrogen, in Fe2O3-reduced graphene oxide nanocomposites is described to address the modification of catalytic performance. The presence of dopants is confirmed by X-ray Photoelectron Spectroscopy analysis, while the integration of iron oxide nanoparticles, by means of decoration of the graphene structure, is corroborated by electron microscopy, which also confirms that there is no damage to the graphene sheets induced by the synthesis procedure. The electrochemical characterizations put in evidence the synergistic catalysis effects of dopant atoms with Fe2O3 and, in particular, the importance of sulfur introduction into the graphene lattice. Catalytic performance of as-prepared materials toward oxygen reduction shows values close to the Pt/C reference material, commonly used for fuel cell and metal–air battery applications. [ABSTRACT FROM AUTHOR]

Let be a semistar operation on a domain D, the finite-type semistar operation associated to , and D a Prüfer -multiplication domain (P MD). For the special case of a Prüfer domain (where is equal to the identity semistar operation), we show that a nonzero prime P of D is sharp, that is, that , where the intersection is taken over the maximal ideals M of D that do not contain P, if and only if two closely related spectral semistar operations on D differ. We then give an appropriate definition of -sharpness for an arbitrary P MD D and show that a nonzero prime P of D is -sharp if and only if its extension to the -Nagata ring of D is sharp. Calling a P MD -sharp (-doublesharp) if each maximal (prime) -ideal of D is sharp, we also prove that such a D is -doublesharp if and only if each -linked overring of D is -sharp. [ABSTRACT FROM AUTHOR]

Dihydrodibenzo[b,f]azepines and dibenzo[b,f]azepines can be efficiently synthesized from aryl bromides, o‐bromoanilines and norbornene or norbornadiene by means of palladium catalysis. This protocol gives access to dibenzo[b,f]azepine core containing a variety of electron‐withdrawing substituents on both aromatic rings and complements the previously reported methodology where electron rich aryl iodides were preferentially used. The presence of KI, even in sub‐stoichiometric amount, is crucial for this three‐component reaction. The proper addition of iodide anions has a dramatic effect on reaction rate and selectivity. A formal three‐step synthesis of the tricyclic antidepressant Clomipramine (Anafranil®) is also described. KI‐ck‐start required: Dibenzo[b,f]azepine derivatives can be efficiently synthesized from aryl bromides, o‐bromoanilines and norbornene or norbornadiene by means of palladium catalysis. The presence of KI, even in sub‐stoichiometric amount, is crucial for this three‐component reaction, as it promotes reaction rate and selectivity. A formal three‐step synthesis of the tricyclic antidepressant Clomipramine (Anafranil®) is also described. [ABSTRACT FROM AUTHOR]

Ruthenium active species containing Ruthenium Sulphide (RuS2) is synthesized together with a self-assembled reduced graphene oxide (RGO) aerogel by a one-pot hydrothermal synthesis. Ruthenium Chloride and L-Cysteine are used as reactants. The hydrothermal synthesis of the innovative hybrid material occurs at 180 °C for 12 h, by using water as solvent. The structure and morphology of the hybrid material are fully characterized by Raman, XRD, XPS, FESEM and TEM. The XRD and diffraction pattern obtained by TEM display an amorphous nanostructure of RuS2 on RGO crystallized flakes. The specific capacitance measured in planar configuration in 1 M NaCl electrolyte at 5 mV s−1 is 238 F g−1. This supercapacitor electrode also exhibits perfect cyclic stability without loss of the specific capacitance after 15,000 cycles. In summary, the RGO/Ruthenium active species hybrid material demonstrates remarkable properties for use as active material for supercapacitor applications. [ABSTRACT FROM AUTHOR]

Let be an integral domain with quotient field . Call an overring of a subring of containing as a subring. A family of overrings of is called a defining family of , if . Call an overring a sublocalization of , if has a defining family consisting of rings of fractions of . Sublocalizations and their intersections exhibit interesting examples of semistar or star operations [D. D. Anderson, Star operations induced by overrings, Comm. Algebra 16 (1988) 2535-2553]. We show as a consequence of our work that domains that are locally finite intersections of Prüfer -multiplication (respectively, Mori) sublocalizations turn out to be Prüfer -multiplication domains (PvMDs) (respectively, Mori); in particular, for the Mori domain case, we reobtain a special case of Théorème 1 of [J. Querré, Intersections d'anneaux intègers, J. Algebra 43 (1976) 55-60] and Proposition 3.2 of [N. Dessagnes, Intersections d'anneaux de Mori - exemples, Port. Math. 44 (1987) 379-392]. We also show that, more than the finite character of the defining family, it is the finite character of the star operation induced by the defining family that causes the interesting results. As a particular case of this theory, we provide a purely algebraic approach for characterizing P MDs as a subclass of the class of essential domains (see also Theorem 2.4 of [C. A. Finocchiaro and F. Tartarone, On a topological characterization of Prüfer -multiplication domains among essential domains, preprint (2014), arXiv:1410.4037]). [ABSTRACT FROM AUTHOR]

We prove that the space of radical ideals of a ring R , endowed with the hull-kernel topology, is a spectral space, and that it is canonically homeomorphic to the space of the non-empty Zariski closed subspaces of Spec ( R ) , endowed with a Zariski-like topology. [ABSTRACT FROM AUTHOR]

We investigate, from a topological point of view, the classes of spectral semistar operations and of eab semistar operations, following methods recently introduced in [11,13] . We show that, in both cases, the subspaces of finite type operations are spectral spaces in the sense of Hochster and, moreover, that there is a distinguished class of overrings strictly connected to each of the two types of collections of semistar operations. We also prove that the space of stable semistar operations is homeomorphic to the space of Gabriel–Popescu localizing systems, endowed with a Zariski-like topology, extending to the topological level a result established in [14] . As a side effect, we obtain that the space of localizing systems of finite type is also a spectral space. Finally, we show that the Zariski topology on the set of semistar operations is the same as the b -topology defined recently by B. Olberding [37,38] . [ABSTRACT FROM AUTHOR]

Many research efforts point nowadays towards the development of flexible, lightweight and efficient energy storage devices. Herein we report a simple procedure for the fabrication of nanostructured electrodes based on Cu x O nanowire/nanoporous layer grown on copper foils and we propose, for the first time to the best of our knowledge, their integration into solid-state pseudo-supercapacitors. An easy and scalable thermal oxidation process in ambient atmosphere is employed to grow a Cu x O film on Cu substrates. Electron microscopy, contact angle measurements, infrared and X-Ray photoelectron spectroscopy are employed to obtain a deep understanding of the morphology, wettability, structure and composition of the copper oxides. We show that the annealing time strongly influences the nanostructures formation promoting the evolution of the oxide film from Cu 2 O to CuO/Cu 2 O bilayer with the subsequent growth of CuO nanowires. The obtained materials represent flexible and binder-free electrodes for pseudo-supercapacitors in which the current collector and the active element are joined in the same substrate without further processing. The electrical characterizations of symmetric devices fabricated with a polymeric electrolyte show the pseudo-capacitive behavior of the proposed nanostructures. [ABSTRACT FROM AUTHOR]

Conspectus: Direct C-H bond activation is an important reaction in synthetic organic chemistry. This methodology has the potential to simplify reactions by avoiding the use of prefunctionalized reagents. However, selectivity, especially site selectivity, remains challenging. Sequential reactions, in which different molecules or groups are combined in an ordered sequence, represent a powerful tool for the construction of complex molecules in a single operation. We have discovered and developed a synthetic methodology that combines selective C-H bond activation with sequential reactions. This procedure, which is now known as the "Catellani reaction", enables the selective functionalization of both the ortho and ipso positions of aryl halides. The desired molecules are obtained with high selectivity from a pool of simple precursors. These molecules are assembled under the control of a palladacycle, which is formed through the joint action of a metal (Pd) and an olefin such as norbornene. These two species act cooperatively with an aryl halide to construct the palladacycle, which is formed through ortho-C-H activation of the original aryl halide. The resulting complex acts as a scaffold to direct the reaction (via Pd(IV)) of other species, such as alkyl or aryl halides and amination or acylation agents, toward the sp² C-Pd bond. At the end of this process, because of steric hindrance, the scaffold is dismantled by norbornene extrusion. Pd(0) is cleaved from the organic product through C-C, C-H, C-N, C-O, or C-B coupling, in agreement with the well-known reactivity of aryl-Pd complexes. The cycle involves Pd(0), Pd(II), and Pd(IV) species. In particular, our discovery relates to alkylation and arylation reactions. Recently, remarkable progress has been made in the following areas: (a) the installation of an amino or an acyl group at the ortho position of aryl halides, (b) the formation of a C-B bond at the ipso position, (c) the achievement of meta-C-H bond activation of aryl rings bearing a chelating directing group by Pd(II)/Pd(IV)/norbornene catalysis, and (d) the activation of N-H and C-H bonds in sequence for indole 2-alkylation. In this Account, we explain the main features of this methodology, describe its synthetic potential, and illustrate some remarkable progress that has been made, emphasizing the most recent developments and applications in total synthesis. [ABSTRACT FROM AUTHOR]

Developments are reported in the catalytic synthesis of biaryls containing an ortho -carbaldehyde or 6 H -dibenzopyrans in the presence of palladium/norbornene as catalyst. The reaction of o -substituted aryl iodides and o -bromobenzyl alcohols proceeds by unsymmetrical aryl-aryl coupling to form a seven-membered oxapalladacycle intermediate, which may undergo an intramolecular redox process to form carbonyl groups or a C–O coupling to six-membered cyclic ethers. The predominant formation of dibenzopyrans as well as of biaryl structures containing the oxidized CHO group in one ring and the reduced CH 2 OH in the other is described along with some mechanistic insights. [ABSTRACT FROM AUTHOR]

We consider properties and applications of a compact, Hausdorff topology called the "ultrafilter topology" defined on an arbitrary spectral space and we observe that this topology coincides with the constructible topology. If K is a field and A a subring of K, we show that the space Zar(K|A) of all valuation domains, having K as the quotient field and containing A, (endowed with the Zariski topology) is a spectral space by giving in this general setting the explicit construction of a ring whose Zariski spectrum is homeomorphic to Zar(K|A). We extend results regarding spectral topologies on the spaces of all valuation domains and apply the theory developed to study representations of integrally closed domains as intersections of valuation overrings. As a very particular case, we prove that two collections of valuation domains of K with the same ultrafilter closure represent, as an intersection, the same integrally closed domain. [ABSTRACT FROM AUTHOR]

Abstract: We provide a complete solution to the problem of extending arbitrary semistar operations of an integral domain D to semistar operations of the polynomial ring . As an application, we show that one can reobtain the main results of the papers in Chang and Fontana (2007, 2011) [1,2] concerning the problem in the special cases of stable semistar operations of finite type or semistar operations defined by families of overrings. Finally, we investigate the behavior of the polynomial extensions of the most important and classical operations such as , , , and operations. [Copyright &y& Elsevier]

This paper introduces a novel contactless sensing principle conceived for measuring the rotation angle of a shaft. The sensor is based on a smart combination of low-cost components that can be effectively integrated in a mechanical assembly of a rotary joint. The working principle is based on the relative rotation of a small diametrically magnetized cylindrical or annular magnet and at least one Hall effect sensor. One of the main strengths of the new sensing principle is to be adaptable to any assigned dimensions and encumbrances without typical design limitations given by the use of standard components. A numerical model is developed for predicting the sensor output characteristic on the base of the concept of magnetic charge. Such a model is validated against results from laboratory experiments. The parameters that define the geometry and layout of the sensor are optimized in order to maximize linearity over an assigned angular range of measurement. Two examples of mechatronic systems that employ the new sensing principle are presented in order to show the possibility of obtaining with the new principle a compact/integrated sensor-design. [ABSTRACT FROM AUTHOR]

LetKbe a field, and letAbe a subring ofK. We consider properties and applications of a compact, Hausdorff topology called the “ultrafilter topology” defined on the space Zar(K | A) of all valuation domains havingKas quotient field and containingA. We show that the ultrafilter topology coincides with the constructible topology on the abstract Riemann-Zariski surface Zar(K | A). We extend results regarding distinguished spectral topologies on spaces of valuation domains. [ABSTRACT FROM AUTHOR]

Abstract: Objective: The aim of this study was to evaluate, through the Scanning Electron Microscopy, the loop closure of four types of stapedial prostheses and to compare the different systems of crimping to the long process of the incus. Materials and methods: Four types of stapedial prostheses (one platinum-teflon, two different titanium and one nitinol-teflon pistons) were inserted in 40 specially prepared temporal bones simulating the in vivo stapedotomy procedure. Two pistons were crimped by single manual manoeuvre with a McGee microforceps; the remainders were self-retained and thermal-crimped, respectively. All the specimens were evaluated through the Operative Microscopy and the Scanning Electron Microscopy. Results: Through the Operative Microscopy, all prostheses apparently achieved a correct adhesion to the long process of the incus; on the contrary the Scanning Electron Microscopy study demonstrated some limits of the manual crimping and the different coupling with the ossicular chain of each type of stapedial prosthesis. Conclusion: A complete adhesion of the prosthetic loop cannot be obtained because of the irregular profile of the incus at the site of attachment of the stapedial prosthesis. Consequently, on the basis of the morphological analysis with Scanning Electron Microscopy, in the surgical practice, the preference could be given to the stapedial prostheses that achieve greater contact such as the self-retaining and thermal crimping pistons compared to the standard sized prostheses considered. [Copyright &y& Elsevier]

In this work we present the design process, the characterization and testing of a novel three-axis mechanical force sensor. This sensor is optimized for use in closed-loop force control of haptic devices with three degrees of freedom. In particular the sensor has been conceived for integration with a dual finger haptic interface that aims at simulating forces that occur during grasping and surface exploration. The sensing spring structure has been purposely designed in order to match force and layout specifications for the application. In this paper the design of the sensor is presented, starting from an analytic model that describes the characteristic matrix of the sensor. A procedure for designing an optimal overload protection mechanism is proposed. In the last part of the paper the authors describe the experimental characterization and the integrated test on a haptic hand exoskeleton showing the improvements in the controller performances provided by the inclusion of the force sensor. [ABSTRACT FROM AUTHOR]

Abstract: Let D be an integral domain with quotient field K. The b-operation that associates to each nonzero D-submodule E of K, , is a semistar operation that plays an important role in many questions of ring theory (e.g., if I is a nonzero ideal in D, coincides with its integral closure). In a first part of the paper, we study the integral domains that are b-Noetherian (i.e., such that, for each nonzero ideal I of D, for some a finitely generated ideal J of D). For instance, we prove that a b-Noetherian domain has Noetherian spectrum and, if it is integrally closed, is a Mori domain, but integrally closed Mori domains with Noetherian spectra are not necessarily b-Noetherian. We also characterize several distinguished classes of b-Noetherian domains. In a second part of the paper, we study more generally the e.a.b. semistar operation of finite type canonically associated to a given semistar operation ⋆ (for instance, the b-operation is the e.a.b. semistar operation of finite type canonically associated to the identity operation). These operations, introduced and studied by Krull, Jaffard, Gilmer and Halter-Koch, play a very important role in the recent generalizations of the Kronecker function ring. In particular, in the present paper, we classify several classes of integral domains having some of the fundamental operations d, t, w and v equal to some of the canonically associated e.a.b. operations b, , and . [Copyright &y& Elsevier]

Call a semistar operation ⊛ on the polynomial domain D[X] an extension (respectively, a strict extension) of a semistar operation ☆ defined on an integral domain D, with quotient field K, if E☆ = (E[X])⊛ ∩ K (respectively, E☆[X] = (E[X])⊛) for all nonzero D-submodules E of K. In this article, we study the general properties of the above defined extensions and link our work with earlier efforts, centered on the stable semistar operation case, at defining semistar operations on D[X] that are 'canonical' extensions (or, 'canonical' strict extensions) of semistar operations on D. [ABSTRACT FROM AUTHOR]

The primary purpose of this paper is give a classification scheme for the nonzero primes of a Prüfer domain based on five properties. A prime P of a Prüfer domain R could be sharp or not sharp, antesharp or not, divisorial or not, branched or unbranched, idempotent or not. Based on these five basic properties, there are six types of maximal ideals and twelve types of nonmaximal (nonzero) primes. Both characterizations and examples are given for each type that exists. [ABSTRACT FROM AUTHOR]

Abstract: We give a classification of e.a.b. semistar (and star) operations by defining four different (successively smaller) distinguished classes. Then, using a standard notion of equivalence of semistar (and star) operations to partition the collection of all e.a.b. semistar (or star) operations, we show that there is exactly one operation of finite type in each equivalence class and that this operation has a range of nice properties. We give examples to demonstrate that the four classes of e.a.b. semistar (or star) operations we defined can all be distinct. In particular, we solve the open problem of showing that a.b. is really a stronger condition than e.a.b. [Copyright &y& Elsevier]

The so-called Prüfer υ-multiplication domains (PυMDs) are usually defined as domains whose finitely generated nonzero ideals are t-invertible. These domains generalize Prüfer domains and Krull domains. The PυMDs are relatively obscure compared to their very well-known special cases. One of the reasons could be that the study of PυMDs uses the jargon of star operations, such as the υ-operation and the t-operation. In this paper, we provide characterizations of and basic results on PυMDs and related notions without star operations. [ABSTRACT FROM AUTHOR]

Let D be an integral domain and X an indeterminate over D. It is well known that (a) D is quasi-Prufer (i.e., its integral closure is a Prufer domain) if and only if each upper to zero Q in D[X] contains a polynomial g ∈ D[X] with content cD(g) = D; (b) an upper to zero Q in D[X] is a maximal t-ideal if and only if Q contains a nonzero polynomial g ∈ D[X] with cD(g)v = D. Using these facts, the notions of UMt-domain (i.e., an integral domain such that each upper to zero is a maximal t-ideal) and quasi-Prufer domain can be naturally extended to the semistar operation setting and studied in a unified frame. In this article, given a semistar operation ☆ in the sense of Okabe-Matsuda, we introduce the ☆-quasi-Prufer domains. We give several characterizations of these domains and we investigate their relations with the UMt-domains and the Prufer v-multiplication domains. [ABSTRACT FROM AUTHOR]

Bimetallic copper-tin catalysts are considered cost-effective and suitable for large-scale electrochemical conversion of CO2 to valuable products. In this work, a class of tin (Sn) modified cuprous oxide (Cu2O) is simply synthesized through a one-pot microwave-assisted solvothermal method and thoroughly characterized by various techniques. Sn is uniformly distributed on the Cu2O crystals showing a cube-within-cube structure, and CuSn alloy phase emerges at high Sn contents. The atomic ratio of Cu to Sn is found to be crucially important for the selectivity of the CO2 reduction reaction, and a ratio of 11.6 leads to the optimal selectivity for CO. This electrode shows a high current density of 47.2 mA cm−2 for CO formation at −1.0 V vs. the reversible hydrogen electrode and also displays good CO selectivity of 80–90% in a wide potential range. In particular, considerable CO selectivity of 72–81% is achieved at relatively low overpotentials from 240 mV to 340 mV. During the long-term tests, satisfactory stability is observed for the optimal electrode in terms of both electrode activity and CO selectivity. The relatively low price, the fast and scalable synthesis, and the encouraging performance of the proposed material implies its good potential to be implemented in large-scale CO2 electrolyzers. [ABSTRACT FROM AUTHOR]

Let R be a commutative ring and let Spec(R) denote the collection of prime ideals of R. We define a topology on Spec(R) by using ultrafilters and demonstrate that this topology is identical to the well-known patch or constructible topology. The proof is accomplished by use of a von Neumann regular ring canonically associated with R. [ABSTRACT FROM AUTHOR]

Abstract: Let D be an integral domain with quotient field K and let X be an indeterminate over D. Also, let be a defining family of quotient rings of D and suppose that * is a finite type star operation on D induced by . We show that D is a P*MD (respectively, PvMD) if and only if (respectively, ) for all . A more general version of this result is given in the semistar operation setting. We give a method for recognizing PvMD''s which are not P*MD''s for a certain finite type star operation *. We study domains D for which the *-class group equals the t-class group for any finite type star operation *, and we indicate examples of PvMD''s D such that . We also compute for certain valuation domains D. [Copyright &y& Elsevier]

Abstract: Given a stable semistar operation of finite type ⋆ on an integral domain D, we show that it is possible to define in a canonical way a stable semistar operation of finite type on the polynomial ring , such that D is a ⋆-quasi-Prüfer domain if and only if each upper to zero in is a quasi--maximal ideal. This result completes the investigation initiated by Houston–Malik–Mott [E. Houston, S. Malik, J. Mott, Characterizations of ∗-multiplication domains, Canad. Math. Bull. 27 (1984) 48–52, Section 2. ] in the star operation setting. Moreover, we show that D is a Prüfer ⋆-multiplication (respectively, a ⋆-Noetherian; a ⋆-Dedekind) domain if and only if is a Prüfer -multiplication (respectively, a -Noetherian; a -Dedekind) domain. As an application of the techniques introduced here, we obtain a new interpretation of the Gabriel–Popescu localizing systems of finite type on an integral domain D (Problem 45 of [S.T. Chapman, S. Glaz, One hundred problems in commutative ring theory, in: S.T. Chapman, S. Glaz (Eds.), Non-Noetherian Commutative Ring Theory, Kluwer Academic Publishers, 2000, pp. 459–476. ]), in terms of multiplicatively closed sets of the polynomial ring . [Copyright &y& Elsevier]

Let D be an integral domain with quotient field K. The Nagata ring D( X) and the Kronecker function ring Kr( D) are both subrings of the field of rational functions K( X) containing as a subring the ring D[ X] of polynomials in the variable X. Both of these function rings have been extensively studied and generalized. The principal interest in these two extensions of D lies in the reflection of various algebraic and spectral properties of D and Spec( D) in algebraic and spectral properties of the function rings. Despite the obvious similarities in definitions and properties, these two kinds of domains of rational functions have been classically treated independently, when D is not a Prfer domain. The purpose of this note is to study two different unified approaches to the Nagata rings and the Kronecker function rings, which yield these rings and their classical generalizations as special cases. [ABSTRACT FROM AUTHOR]

Abstract: We show that in certain Prüfer domains, each nonzero ideal can be factored as , where is the divisorial closure of and is a product of maximal ideals. This is always possible when the Prüfer domain is -local, and in this case such factorizations have certain uniqueness properties. This leads to new characterizations of the -local property in Prüfer domains. We also explore consequences of these factorizations and give illustrative examples. [Copyright &y& Elsevier]

We introduce a new general construction, denoted by R ⋈ E, called the amalgamated duplication of a ring R along an R-module E, that we assume to be an ideal in some overring of R. (Note that, when E2 = 0, R ⋈ E coincides with the Nagata's idealization R ⋉ E.). After discussing the main properties of the amalgamated duplication R ⋈ E in relation with pullback-type constructions, we restrict our investigation to the study of R ⋈ E when E is an ideal of R. Special attention is devoted to the ideal-theoretic properties of R ⋈ E and to the topological structure of its prime spectrum. [ABSTRACT FROM AUTHOR]

A natural development of the recent work about semistar operations leads to investigate the concept of “semistar invertibility”. Here, we show the existence of a “theoretical obstruction” for extending many results, proved for star-invertibility, to the semistar case. For this reason, we introduce two distinct notions of invertibility in the semistar setting (called ⋆-invertibility and quasi-⋆-invertibility), we discuss the motivations of these “two levels” of invertibility and we extend, accordingly, many classical results proved for the d-, v-, t- and w-invertibility. [ABSTRACT FROM AUTHOR]

Abstract: For the domain R arising from the construction T, M, D, we relate the star class groups of R to those of T and D. More precisely, let T be an integral domain, M a nonzero maximal ideal of T, D a proper subring of , the natural projection, and let . For each star operation * on R, we define the star operation on D, i.e., the “projection” of * under φ, and the star operation on T, i.e., the “extension” of * to T. Then we show that, under a mild hypothesis on the group of units of T, if * is a star operation of finite type, then the sequence of canonical homomorphisms is split exact. In particular, when , we deduce that the sequence is split exact. The relation between and (and between and ) is also investigated. [Copyright &y& Elsevier]

Call a domain R an sQQR-domain if each simple overring of R, i.e., each ring of the form R[u] with u in the quotient field of R, is an intersection of localizations of R. We characterize Prüfer domains as integrally closed sQQR-domains. In the presence of certain finiteness conditions, we show that the sQQR-property is very strong; for instance, a Mori sQQR-domain must be a Dedekind domain. We also show how to construct sQQR-domains which have (non-simple) overrings which are not intersections of localizations. [ABSTRACT FROM AUTHOR]

Let D be an integral domain and ★ a semistar operation on D. As a generalization of the notion of Noetherian domains to the semistar setting, we say that D is a ★-Noetherian domain if it has the ascending chain condition on the set of its quasi-★-ideals. On the other hand, as an extension the notion of Prüfer domain (and of Prüfer v-multiplication domain), we say that D is a Prüfer ★-multiplication domain (P★MD, for short) if DM is a valuation domain, for each quasi-★f-maximal ideal M of D. Finally, recalling that a Dedekind domain is a Noetherian Prüfer domain, we define a ★-Dedekind domain to be an integral domain which is ★-Noetherian and a P★MD. For the identity semistar operation d, this definition coincides with that of the usual Dedekind domains and when the semistar operation is the v-operation, this notion gives rise to Krull domains. Moreover, Mori domains not strongly Mori are ★-Dedekind for a suitable spectral semistar operation.Examples show that ★-Dedekind domains are not necessarily integrally closed nor one-dimensional, although they mimic various aspects, varying according to the choice of ★, of the “classical” Dedekind domains. In any case, a ★-Dedekind domain is an integral domain D having a Krull overring T (canonically associated to D and ★) such that the semistar operation ★ is essentially “univocally associated” to the v-operation on T.In the present paper, after a preliminary study of ★-Noetherian domains, we investigate the ★-Dedekind domains. We extend to the ★-Dedekind domains the main classical results and several characterizations proven for Dedekind domains. In particular, we obtain a characterization of a ★-Dedekind domain by a property of decomposition of any semistar ideal into a “semistar product” of prime ideals. Moreover, we show that an integral domain D is a ★-Dedekind domain if and only if the Nagata semistar domain Na(D,★) is a Dedekind domain. Several applications of the general results are given for special cases of the semistar operation ★. [Copyright &y& Elsevier]

In this paper we study the star operations on a pullback of integral domains. In particular, we characterize the star operations of a domain arising from a pullback of “a general type” by introducing new techniques for “projecting” and “lifting” star operations under surjective homomorphisms of integral domains. We study the transfer in a pullback (or with respect to a surjective homomorphism) of some relevant classes or distinguished properties of star operations such as v−, t−, w−, b−, d−, finite type, e.a.b., stable, and spectral operations. We apply part of the theory developed here to give a complete positive answer to a problem posed by D.F. Anderson in 1992 concerning the star operations on the “D+M” constructions. [Copyright &y& Elsevier]

In 1994, Matsuda and Okabe introduced the notion of semistar operation, extending the "classical" concept of star operation. In this paper, we introduce and study the notions of semistar linkedness and semistar flatness which are natural generalizations, to the semistar setting, of their corresponding "classical" concepts. As an application, among other results, we obtain a semistar version of Davis' and Richman's overring-theoretical theorems of characterization of Prüfer domains for Prüfer semistar multiplication domains. [ABSTRACT FROM AUTHOR]

In 1994, Matsuda and Okabe introduced the notion of semistar operation. This concept extends the classical concept of star operation (cf. for instance, Gilmer's book (Gilmer, R. (1972). Multiplicative Ideal Theory. New York: Marcel Dekker) and, hence, the related classical theory of ideal systems based on the works by W. Krull, E. Noether, H. Prüfer and P. Lorenzen from 1930's. Fontana and Loper investigated properties of the Kronecker function rings which arise from arbitrary semistar operations on an integral domain D (Fontana M., Loper K. A. (2001a). Kronecker function rings: a general approach. In Anderson, D. D., Papick, I. J., eds. Ideal Theoretic Methods in Commutative Algebra. Lecture Notes Pure Appl. Math. 220, Marcel Dekker, pp. 189–205 and Fontana, M., Loper, K. A. (2001b). A Krull-type theorem for the semistar integral closure of an integral domain. ASJE Theme Issue “Commutative Algebra” 26:89–95). In this paper we extend that study and also generalize Kang's notion of a star Nagata ring to the semistar setting (Kang, B. G. (1987). ⋆-Operations on Integral Domains. Ph.D. dissertation, Univ. Iowa and Kang, B. G. (1989). Prüfer v-multiplication domains and the ring R[X]Nv, J. Algebra 123: 151–171). Our principal focuses are the similarities between the ideal structure of the Nagata and Kronecker semistar rings and between the natural semistar operations that these two types of function rings give rise to on D. [ABSTRACT FROM AUTHOR]

Let R be an integral domain, I an ideal of R and ΩR(I) the Kaplansky transform of R with respect to I. A ring homomorphism α : R→A is called an I-morphism if α−1(Q)⊉I for each prime ideal Q of A. We denote by KR(I,A) the set of all the I-morphisms from R to A. It is easy to see that KR(I,−) defines a covariant functor from Ring to Set. We prove that the following statements are equivalent: (i) KR(I,−) : Ring→Set is a representable functor; (ii) the natural embedding R→ΩR(I) is an I-morphism; (iii) IΩR(I)=ΩR(I); (iv) D(I)={P∈Spec(R) | P⊉I} is an open affine subscheme of Spec(R). [Copyright &y& Elsevier]

The main purpose of this paper is to undertake a more indepth study of the link between Nagata ideal transforms and the rings of fractions with respect to localizing systems. The principal result obtained here is a characterization of when the Nagata ideal transform T(I) of an ideal I of an integral domain R is a ring of fractions of R with respect to a localizing system; in this case, we also give a description of the localizing system F of R such that T(I) = R[sub F]. [ABSTRACT FROM AUTHOR]

[Display omitted] • Amino modified MWCNT sorbents are prepared with different structural properties. • Amino modified materials show CO 2 selectivity on CO 2 /N 2 adsorption-separation tests. • Higher N content and microporosity is linked with the best CO 2 up-take profiles. • The best amino-modified MWCNT material is water-resistant and multicycle reusable. Multi-walled carbon nanotubes (MWCNT) with different functionalities (standard–; OH–; and COOH– functionalized) are chemically modified with N1-(3-trimethoxysilylpropyl)diethylenetriamine (DETASi) aiming to enhance their CO 2 adsorption/separation properties. The grafting of the DETASi groups to the surface of the MWCNT samples is studied by X-ray photoelectron spectroscopy (XPS), operando thermogravimetric analysis - infrared spectroscopy (TGA-IR), –196 °C N 2 -sorption isotherms, and scanning electron microscopy (SEM). A comprehensive overview of the reaction mechanism and samples structure/composition is provided. It was found that the aforementioned functionalities highly influence the physical–chemical and the textural properties of the DETASi modified-MWCNT materials, impacting in the DETASi functionalization degree and its distribution on the sample. Amount (by TGA-IR) and homogeneity (by SEM) of the organosilicon group in the functionalized samples increases with the increase of the functionalities in the parent MWCNT materials. Standard-MWCNT and OH– functionalized MWCNT showed to be unable to adsorb CO 2 , while COOH– modified MWCNT adsorbed just 0.1% at 1 bar and 30 °C. At the same adsorption conditions, DETASi modification of the MWCNT materials enhanced the CO 2 adsorption capacity, with the maximum CO 2 uptake (2.11%) for COOH-MWCNT functionalized with DETASi. The selectivity for CO 2 /N 2 separation was also improved after DETASi grafting reaction, with the highest value (1.89%) observed for the standard-MWCNT material modified with DETASi. In general, the increase of the DETASi amount and of the microporosity in the functionalized MWCNT sorbents is accompanied by an improvement of the CO 2 adsorption-separation properties. The water vapor adsorption indicated that the standard-MWCNT sample modified with DETASi is resistant to the presence of water and its presence (water vapor of ~3.2 kPa) can improve the CO 2 uptake. [ABSTRACT FROM AUTHOR]

This paper presents a principle to develop multi‐function dielectric elastomer actuators (DEAs) that can concurrently accomplish linear actuation and sound generation through a single electrical input. A centimeter‐scale cone‐shaped DEA is fabricated using silicone‐based dielectric and electrodes. Measurements of the vibro‐acoustic response reveal that the pumping deformation of the DEA contributes to a negligible extent in the sound generation, which is hence ascribable to higher order structural modes whose frequency pass‐band is highly uncoupled from that of the pumping mode. Exciting the DEA with a multi‐chromatic input voltage allows achieving strokes close to 1 mm or blocking forces over 0.5 N, while simultaneously generating sound pressure levels over 60 dB, regardless of possible forces and/or mechanical constraints on the DEA pumping motion. The ability of the DEA to concurrently generate linear actuation and sound is demonstrated via proof‐of‐concept tests: the DEA can reproduce music, while at the same time generating a deformation pulse or lifting a load comparable with its own blocking force. Furthermore, measuring the current generated by the DEA allows detecting deformations impressed by the exterior and use the DEA as an active audio‐tactile interface, which produces a combined vibro‐acoustic stimulus in response to a user's touch. [ABSTRACT FROM AUTHOR]

The aim of this paper is to shed light on the application of graphene oxide (GO) membranes for the selective removal of benzene, toluene, and xylene (BTX) from wastewater. These molecules are present in traces in the water produced from oil and gas plants and are treated now with complex filtration systems. GO membranes are obtained by a simple, fast, and scalable method. The focus of this work is to prove the possibility of employing GO membranes for the filtration of organic contaminants present in traces in oil and gas wastewater, which has never been reported. The stability of GO membranes is analyzed in water solutions with different pH and salinity. Details of the membrane preparation are provided, resulting in a crucial step to achieve a good filtration performance. Material characterization techniques such as electron microscopy, x-ray diffraction, and infrared spectroscopy are employed to study the physical and chemical structure of GO membranes, while gas chromatography, UV-visible spectroscopy, and gravimetric techniques allow the quantification of their filtration performance. An impressive rejection of about 90% was achieved for 1 ppm of toluene and other pollutants in water, demonstrating the excellent performance of GO membranes in the oil and gas field. [ABSTRACT FROM AUTHOR]

This work aims to improve upon the aluminium impact attenuator currently used by the University of Lisbon Formula Student team through a composite solution. The influence of geometrical variations, particularly the use of curved walls, and the number of objectives considered for the optimization are studied. To perform the optimizations, Abaqus is coupled with the Direct Multisearch (DMS) algorithm, the overall performance of the solutions is evaluated and the influence of the introduction of curved walls on the energy absorption capabilities discussed. Off-axis impacts are studied and the effect of curved walls in that situation analysed. An overview of the best configurations achieved is provided and one final configuration is selected. • Design and optimization of a composite impact absorber to be used in an Formula Student car is presented. • The importance of the use of curved-walled structure was evident throughout the present work. • Off-axis impacts are studied. • To perform the optimizations, Abaqus is coupled with the Direct Multisearch (DMS) algorithm. [ABSTRACT FROM AUTHOR]

Underground Hydrogen Storage (UHS) provides a large-scale and safe solution to balance the fluctuations in energy production from renewable sources and energy consumption but requires a proper and detailed characterization of the candidate reservoirs. The scope of this study was to estimate the hydrogen diffusion coefficient for real caprock samples from two natural gas storage reservoirs that are candidates for underground hydrogen storage. A significant number of adsorption/desorption tests were carried out using a Dynamic Gravimetric Vapor/Gas Sorption System. A total of 15 samples were tested at the reservoir temperature of 45 °C and using both hydrogen and methane. For each sample, two tests were performed with the same gas. Each test included four partial pressure steps of sorption alternated with desorption. After applying overshooting and buoyancy corrections, the data were then interpreted using the early time approximation of the solution to the diffusion equation. Each interpretable partial pressure step provided a value of the diffusion coefficient. In total, more than 90 estimations of the diffusion coefficient out of 120 partial pressure steps were available, allowing a thorough comparison between the diffusion of hydrogen and methane: hydrogen in the range of 1 × 10−10 m2/s to 6 × 10−8 m2/s and methane in the range of 9 × 10−10 m2/s to 2 × 10−8 m2/s. The diffusion coefficients measured on wet samples are 2 times lower compared to those measured on dry samples. Hysteresis in hydrogen adsorption/desorption was also observed. [ABSTRACT FROM AUTHOR]

A class of metal-doped polyanilines (PANIs) was synthesized and investigated as electrocatalysts for the carbon dioxide reduction reaction (CO2RR). These materials show good affinity for the electrode substrate and allow to obtain stable binder-free electrodes, avoiding the utilization of expensive ionomer and additives. The emeraldine-base polyaniline (EB-PANI), in absence of metal dopant, shows negligible electrocatalytic activity and selectivity toward the CO2RR. Such behavior significantly improves once EB-PANI is doped with an appropriate cationic metal (Mn, Cu or Sn). In particular, the Sn-PANI outperforms other metal-doped samples, showing a good turnover frequency of 72.2 h−1 for the CO2RR at − 0.99 V vs the reversible hydrogen electrode and thus satisfactory activity of metal single atoms. Moreover, the Sn-PANI also displays impressive stability with a 100% retention of the CO2RR selectivity and an enhanced current density of 4.0 mA cm−2 in a 10-h test. PANI, a relatively low-cost substrate, demonstrates to be easily complexed with different metal cations and thus shows high tailorability. Complexing metal with conductive polymer represents an emerging strategy to realize active and stable metal single-atom catalysts, allowing efficient utilization of metals, especially the raw and precious ones. [ABSTRACT FROM AUTHOR]

SUMMARY: This paper presents an experimental study on new paradigms of haptic-based teleoperated navigation of underwater vehicles. Specifically, the work is focused on investigating the possibility of enhancing the user interaction by introducing haptic cues at the level of the user wrist providing a force feedback that reflects dynamic forces on the remotely operated underwater vehicle. Different typologies of haptic controllers are conceived and integrated with a real-time simulated model of an underwater robotic vehicle. An experimental test is designed to evaluate the usability of the system and to provide information on the global performance during the execution of simple tasks. Experiments are conducted with 7 candidates testing 12 different controllers. Among these, the most effective strategies have been identified and selected on the basis of minimization of errors on the vehicle trajectory and of the quality of the user's interaction in terms of perceived comfort during operation. Overall, the results obtained with this study underline that haptic navigation control can have a positive influence on the performance of remotely controlled underwater vehicles. [ABSTRACT FROM AUTHOR]

Spinal deformity is an abnormality in the spinal curves and can seriously affect the activities of daily life. The conventional way to treat spinal deformities, such as scoliosis, kyphosis, and spondylolisthesis, is to use spinal orthoses (braces). Braces have been used for centuries to apply corrective forces to the spine to treat spinal deformities or to stabilize the spine during postoperative rehabilitation. Braces have not modernized with advancements in technology, and very few braces are equipped with smart sensory design and active actuation. There is a need to enable the orthotists, ergonomics practitioners, and developers to incorporate new technologies into the passive field of bracing. This article presents a review of the conventional passive braces and highlights the advancements in spinal orthoses in terms of improved sensory designs, active actuation mechanisms, and new construction methods (CAD/CAM, three-dimensional (3D) printing). This review includes 26 spinal orthoses, comprised of passive rigid/soft braces, active dynamics braces, and torso training devices for the rehabilitation of the spine. [ABSTRACT FROM AUTHOR]