Search

Immobilized cobalt nanoparticles on SiO2 reduced via hydrogenation–carburization–hydrogenation (H C H) afforded a 40% higher CO conversion compared to the standard H 2 treatment. The H C H treatment increased the catalyst reducibility and the dispersion of Co-hcp, with a high intrinsic activity for Fischer–Tropsch synthesis (FTS), via the Co2C intermediate. It is postulated that the Co2C was responsible for the high CH4 and olefin selectivity observed over the H C H treated sample, which resulted in a detrimental effect on the selectivity of liquid fuels. Nonetheless, this is a groundbreaking contribution to future FTS catalyst design and for synthetic fuel production.

We present a three-dimension (3-D) to two-dimension (2-D) reduction procedure for the plates with the unidirectional system of inhomogeneities (fibers, cylindrical channels, etc.). The original 3-D...

Hydroboration of amides is a useful synthetic strategy to access the corresponding amines. In this contribution, it was found that the supported lanthanum benzyl material La(CH2C6H4NMe2-o)3@SBA-15 was highly active for the hydroboration of primary, secondary, and tertiary amides to amines with pinacolborane. These reactions selectively produced target amines and showed good tolerance for functional groups such as -NO2, -halogen, and -CN, as well as heteroatoms such as S and O. This reduction procedure exhibited the recyclable and reusable property of heterogeneous catalysts and was applicable to gram-scale synthesis. The reaction mechanisms were proposed based on some control experiments and the previous literature. This is the first example of hydroborative reduction of amides to amines mediated by heterogeneous catalysts.

Reducing the order of positive real and bounded real systems has received great interest over the years. Several methods have been published regarding these issues which are able to produce positive real or bounded real reduced models. However, none of them can guarantee that the reduced models are both positive real and bounded real at the same time. In this brief, a novel model reduction scheme is presented which focuses on preserving two possible properties of the system (positive realness and bounded realness) simultaneously. This is done by using one positive real Riccati equation and one bounded real Riccati equation in the reduction procedure. Thereafter, the gramians extracted from these Riccati equations are balanced based on the Balanced Truncation (BT) concept. Finally, a numerical example is provided to investigate the efficacy of the proposed method.

Complications of laser hair reduction should be classified not only to skin and ocular complications but to skin, ocular, and scalp hair complications. Do not forget the plumes. Awareness about laser dangers is very critical. In this way, able to progress the security of both patients and laser providers. Does Nd: YAG cause more bad effect than Alexandrite on scalp hair melanin of laser providers and why? The study aimed at detecting the effect of cumulative exposure to scattered beam during laser hair reduction on the laser providers which may cause unexpected scalp hair melanin affection. The study included 150 female subjects: One hundred medical personnel engaged in laser-assisted hair reduction procedure; half of them were wearing head cover (hijab) and 50 female subjects not dealing with hair reduction laser systems (half of them were wearing hijab). Two laser devices were used: Alexandrite laser (GentleLase PRO® 755 nm, Candela Corp., Wayland, MA, USA) and neodymium-doped Yttrium Aluminium Garnet (Nd: YAG) (Synchro HP 1064 nm, Deka M.E.L.A s.r.l., Calenzano (FI), Italy) laser. A significant higher number of grey hairs in medical personnel (P

Let (Pn ) n≥0 be the sequence of Padovan numbers defined by P 0 = 0, P 1 = 1 = P 2, and P n+3 = P n+1 +Pn for all n ≥ 0. In this paper, we find all Padovan numbers that are concatenations of two distinct repdigits.

The validity of using kinetic scheme reduction procedures to compare various kinetic models as well as the values of kinetic parameters of individual steps present in the literature is analyzed. The peculiarities of the development of the gas-phase reaction block as a part of the heterogeneous-homogeneous model of the oxidative coupling of methane (OCM) are considered and approaches to the selection of kinetic parameters of elementary steps are analyzed. It has been demonstrated that kinetic models developed in accordance with the principle of “independence of kinetic parameters” can exhibit low predictive power due to existing uncertainties in the values of the parameters presented in well-known review papers and databases. In addition, the effects of the accounting of the heterogeneous reaction block and variation of the OCM reaction conditions on the results of the reduction of the detailed kinetic scheme are addressed. It has been shown that the use of reduction procedures to analyze the mechanism of complex processes is limited due to the high degree of conjugation between their individual stages and the strong dependence of kinetic constants on the parameters of state.

In this paper, by using linear forms in logarithms and the Baker–Davenport reduction procedure we prove that there are no even perfect numbers appearing in generalized Pell sequences. We also deduce some interesting results involving generalized Pell numbers, which we believe are of independent interest. This paper continues a previous work that searched for perfect numbers in the classical Pell sequence.

In this paper we investigate the compatibility of the BRST reduction procedure with the Hermiticity of star products. First, we introduce the generalized notion of abstract BRST algebras with corresponding involutions. In this setting we define adjoint BRST differentials and as a consequence one gets new BRST quotients. Passing to the quantum BRST setting we show that for compact Lie groups the new quantum BRST quotient and the quantum BRST cohomology are isomorphic in zero degree implying that reduction is compatible with Hermiticity., Comment: 24 pages. To appear in Communications in Mathematical Physics

Ruthenium particles with size from 1 to 7 nm were formed by reduction of ruthenium complexes with urea, ethylenediaminetetraacetic acid, acetone azine, 1,2-Bis(2-furylmethylene)hydrazine) inside halloysite nanotubes. Catalysts of different morphology with Ru content from 0.75 to 0.93 %wt. were obtained using NaBH4 or H2 as reducing agents and tested in benzene hydrogenation as a model reaction. NaBH4 reduced catalysts showed similar catalytic activity with 100 % benzene conversion after 1.5 h. Reduction with H2 resulted in a decrease of catalytic activity for all samples. High benzene conversion was achieved only in the case of 1,2-Bis(2-furylmethylene)hydrazine and ethylenediaminetetraacetic acid. It was concluded that the thermal stability of complexing agents plays a key role in activity of catalysts reduced with H2.

This study was performed to develop a new rat model of reduced masticatory activity in order to assess the effect of this reduction on the morphology of the temporomandibular joint (TMJ) over time. Female rats were used, and ovariectomy was performed to simulate aged/postmenopausal status. Twenty-four SD rats aged 6 weeks were divided into four groups: ovariectomy/sham procedure (Ov/S); ovariectomy/reduced masticatory activity (Ov/RMA); non-Ov/S (NO/S); and non-Ov/RMA (NO/RMA). The RMA procedure involved grinding down the edges of the upper and mandibular incisors by about 3 mm and supplying the rats with a powdered diet. The bilateral TMJ was examined by micro-computed tomography at 0, 1, 2, 4, 6, and 8 weeks after the start of RMA. Condylar width was greater in the NO/S group than in the Ov/S group after the 2nd week, showing that ovariectomy reduced the width of the condyle. After the 2nd week, significant differences in condylar width were apparent between the NO/S and NO/RMA groups, and between the Ov/S and Ov/RMA groups. This RMA procedure appeared to provide a good model of reduced masticatory activity. The present findings in female rats suggest that reduction of appropriate mastication activity in the growth period results in poor growth of the mandibular condyle and immediately induces atrophy of the mandibular condyle under conditions simulating aged/postmenopausal status.

Objective To assess the value and limitation of cervical traction in the evaluation of the reducibility of atlantoaxial dislocation (AAD) and basilar invagination (BI) using the intraoperative O-arm. Methods A total of 22 patients with hyperextensive, irreducible AAD were included. The cervical traction test under general anesthesia was performed, and the degree of reduction was evaluated using the O-arm before the operation started. The traction effects both vertically and horizontally were evaluated. All cases then underwent modified direct posterior reduction and fixation. Clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) scale. Radiologic measurements included the anterior atlantodental interval, the distance of odontoid tip above Chamberlain line, and the clivus–canal angle. Magnetic resonance imaging signal changes, size of syringomyelia, and the space ventral to medulla also were used to evaluate the postoperative reduction result. Results After the cervical traction test, 7 patients achieved incomplete reduction, 5 achieved only vertical reduction, 6 achieved only horizontal reduction, and 4 achieved complete reduction in both horizontal and vertical orientations as assessed by the O-arm. All patients underwent a direct reduction technique. The mean JOA score increased from 11.1 to 14.5. Complete reduction of AAD and BI were achieved in 19 patients (86.4%), with partial reduction achieved in 3 (13.6%). Sufficient cerebrospinal fluid space anterior to the medulla with improved JOA score was achieved in the 3 partially reduced patients. Conclusions With the innovations of direct posterior reduction techniques, cervical traction under anesthesia may not sufficiently predict the reducibility of BI and AAD. Cervical traction still plays an important role during the direct posterior reduction procedure.

Pure MoO2 and MoO2/Mo are tuned via temperature control in a facile high temperature reduction procedure. Graphene oxide (GO) is then composited into them through physical mixing followed by freeze-drying. When assembled as anodes for Li-ion batteries, samples containing Mo, including MoO2/Mo and MoO2/Mo-GO, possess not only high initial columbic efficiency (ICE) but also high capacity, stability and rate performance. The MoO2/Mo hybrid exhibits a rather high ICE of 97%. The ICE of the MoO2/Mo-GO is still high as 85% with a largely enhanced capacity of 400 mA h g−1, which is gradually increased to 550 mA h g−1 after 150 cycles.

Open access version at https://arxiv.org/pdf/1810.04962.pdf, We discuss, in all generality, the reduction of a Hamilton — Jacobi theory for systems subject to nonholonomic constraints and invariant under the action of a group of symmetries. We consider nonholonomic systems subject to both linear and nonlinear constraints and with different positioning of such constraints with respect to the symmetries., This work has been partially supported by MINECO Grants MTM2016-76-072-P and the ICMAT Severo Ochoa projects SEV-2011-0087 and SEV-2015-0554. V.M. Jiménez wishes to thank MINECO for a FPI-PhD position.

In this paper, we study some Cauchy matrix type solutions for the nonlocal nonlinear Schrodinger equations, including Cauchy matrix type multisoliton solutions and Cauchy matrix type Jordan block solutions. These solutions are obtained from the Cauchy matrix type solutions of Ablowitz–Kaup–Newell–Segur equation through nonlocal reduction. The reduction procedure developed in this paper can apply to other systems which have Cauchy matrix type solutions and admit local and nonlocal reductions.

This paper considers a process for the creation and subsequent firing of sequences of neuronal patterns, as might be found in the human brain. The scale is one of larger patterns emerging from an ensemble mass, possibly through some type of energy equation and a reduction procedure. The links between the patterns can be formed naturally, as a residual effect of the pattern creation itself. This paper follows-on closely from the earlier research, including two earlier papers in the series and uses the ideas of entropy and cohesion. With a small addition, it is possible to show how the inter-pattern links can be determined. A compact Grid form of an earlier Counting Mechanism is also demonstrated and may be a new clustering technique. It is possible to explain how a very basic repeating structure can form the arbitrary patterns and activation sequences between them, and a key question of how nodes synchronise may even be answerable.

We revisit generalized Kahler reduction introduced by Lin and Tolman (2006) from a viewpoint of geometric invariant theory. It is shown that in the strong Hamiltonian case introduced in the present paper, many well-known conclusions of ordinary Kahler reduction can be generalized without much effort to the generalized setting. It is also shown how generalized holomorphic structures arise naturally from the reduction procedure.

A procedure for obtaining an interpreted and high-precision classifier which consists of two steps is proposed. At the first step, the rules of the original classifier, of which it consists, are modified using the aggregation procedure. It is applied to each rule and is aimed at making it more informative. At the second step, the classifier reduction procedure is performed based on the normalized boosting criterion. An empirical confirmation of the expediency of such a procedure is given. #CSOC1120.

OBJECTIVE. Intussusception is the most common cause of intestinal obstruction in young children. Radiology has a key role in its diagnosis and treatment. This systematic review summarizes the currently available evidence for best practices in radiologic management of pediatric intussusception. CONCLUSION. High diagnostic accuracy and lack of ionizing radiation make ultrasound (US) the preferred imaging modality for diagnosing intussusception. For intussusception reduction, fluoroscopy-guided pneumatic enema and US-guided hydrostatic enema are equally dependable and safe techniques. The areas that warrant further research in this field include the efficacy and safety of the US-guided pneumatic enema, potential benefits of sedation and general anesthesia for the reduction procedure, and the optimal management of intussusceptions potentially involving pathologic lead points.

Let $$ (T_{n})_{n\ge 0} $$ ( T n ) n ≥ 0 be the sequence of Tribonacci numbers defined by $$ T_0=0 $$ T 0 = 0 , $$ T_1=T_2=1$$ T 1 = T 2 = 1 , and $$ T_{n+3}= T_{n+2}+T_{n+1} +T_n$$ T n + 3 = T n + 2 + T n + 1 + T n for all $$ n\ge 0 $$ n ≥ 0 . In this note, we use of lower bounds for linear forms in logarithms of algebraic numbers and the Baker-Davenport reduction procedure to find all Tribonacci numbers that are concatenations of two repdigits.

Ironsand is a type of titanic-ferrous solution ore. As most ironsands come from rapidly cooled lava, raw ironsand particles consist of complicated distributions of elements and a variety of Ti–Fe solid solution phases. In this study, samples of raw and pre-oxidized ironsands were reduced by hydrogen at 900°C for different time intervals. The formation of multiple microstructures of ironsand during the reduction process were investigated. For raw ironsand, a three-layer core structure, an incompletely reduced core structure, and a lump/net structure appeared in order with the reduction procedure. However, for pre-oxidized ironsand, the unit cells of major phases of ironsand shrink, leading to the formation of microcracks during the oxidation pretreatment. These cracks in turn trigger unordered reduction structures, significantly accelerating the reaction kinetics.

We study robustness of dc power networks with controllable link susceptances, or weights , toward balanced disturbances to a nominal supply–demand vector. Consider the set of balanced disturbances, for which there exist feasible link weights so that the resulting link flows are within specified capacity bounds. The margin of robustness is defined as the radius of the largest $\ell _1$ ball around the origin, which belongs to this set. Computation of this margin can be posed as a nonconvex optimization problem. We propose an equivalent multilevel programming approach for a class of networks, in which the nodes with nonzero demand or supply are relatively sparse. This approach is based on recursive application of equivalent bilevel formulation for a relevant class of, possibly nonconvex, optimization problems. The lower level problem in each recursion corresponds to replacing a subnetwork by a (virtual) link with equivalent weight and capacity functions. The equivalent capacity function for a link-reducible network possesses a strong quasi-concavity property. This property facilitates an easy solution to the multilevel programming formulation for tree-reducible networks . The computational gain from such a reduction procedure is illustrated via simulations on a benchmark IEEE network.

The CuO-CeO2@SiO2 catalyst with flower-sphere morphology was prepared by the impregnation method and then experienced the reduction-oxidation treatment at different temperatures. The multi-technique characterization shows that the reduction-oxidation treatment can remodel CuO, improve textural and surface properties and change Cu+ content and synergistic effect of copper and cerium. The importance of this work lies in the fact that the decrease of Cu+ content and synergistic effect of copper and cerium that occurs in the reduction-oxidation process results in the decrease of catalytic activity over the CuO-CeO2@SiO2 catalyst for preferential CO oxidation. The process of reaction in rich-hydrogen streams is equivalent to a reduction procedure which decreases Cu+ content and synergistic effect of copper and cerium.

Data clustering refers to the partition of a dataset into homogeneous subsets where each subset is dissimilar to the rest of the subsets. K-means is a familiar approach for data clustering particularly when all the attributes of the data objects are of numeric type. Though the k-means approach is popular and efficient it is susceptible to misclassify the data due to the noise and outliers that are common in datasets. The aim of this paper is to study the strategies available to overcome the problems like high dimensionality, redundancy, noise and outliers while implementing the k-means algorithm and to propose a better approach to deal with the problem. An iterative attribute reduction procedure based on correlations among attributes was proposed to cluster the given dataset using k-means algorithm in an improved manner. The standard dataset “Iris” was used to test the proposed methodology. The obtained results are reasonably better.

In this note we consider Gentzen's first ordinal notation, used in his first published proof of the consistency of Peano Arithmetic (1936). It is a decimal notation, quite different from our current notations. We give a rule to translate this notation into our usual set-theoretic notation and we show some of its peculiarities. Then we indicate how to decode Gentzen's assignment of ordinal notations to derivations and give some examples. Finally, we go through his proof of their decrease after the application of his reduction procedure, giving further examples.

Human activities generate more hazard wastes (HWs) than can be handled by the technologies available. Due to the rapid growth of industrial and commercial activities in past decades, the products as well as the wastes containing Hazardous Materials (HMs) have increased drastically in both volume and type. Avoiding and treating HMs thus represents a crucial task for the industry on the pathway to a sustainable future. In the present paper, an Efficiency-Oriented Batch Reduction Procedure (EO-BRP) is introduced, which aims at supporting plants in reducing the use of HMs. EO-BRP has been validated by reducing the HMs in three different production sites. The results show an increase of efficiency by allowing the analysis of a large number of different materials in a shorter processing time.

Mapping of disulfide bonds is an essential part of protein characterization to ensure correct cysteine pairings. For this, mass spectrometry (MS) is the most widely used technique due to fast and accurate characterization. However, MS-based disulfide mapping is challenged when multiple disulfide bonds are present in complicated patterns. This includes the presence of disulfide bonds in nested patterns and closely spaced cysteines. Unambiguous mapping of such disulfide bonds typically requires advanced MS approaches. In this study, we exploited in-source reduction (ISR) of disulfide bonds during the electrospray ionization process to facilitate disulfide bond assignments. We successfully developed a LC-ISR-MS/MS methodology to use as an online and fully automated partial reduction procedure. Postcolumn partial reduction by ISR provided fast and easy identification of peptides involved in disulfide bonding from nonreduced proteolytic digests, due to the concurrent detection of disulfide-containing peptide species and their composing free peptides. Most importantly, intermediate partially reduced species containing only a single disulfide bond were also generated, from which unambiguous assignment of individual disulfide bonds could be done in species containing closely spaced disulfide bonds. The strength of this methodology was demonstrated by complete mapping of all four disulfide bonds in lysozyme and all 17 disulfide bonds in human serum albumin, including nested disulfide bonds and motifs of adjacent cysteine residues.

Reduction theory has played a major role in the study of Hamiltonian systems. Whilst the Hamilton–Jacobi theory is one of the main tools to integrate the dynamics of certain Hamiltonian problems and a topic of research on its own. Moreover, the construction of several symplectic integrators relies on approximations of a complete solution of the Hamilton–Jacobi equation. The natural question that we address in this paper is how these two topics (reduction and Hamilton–Jacobi theory) fit together. We obtain a reduction and reconstruction procedure for the Hamilton–Jacobi equation with symmetries, even in a generalized sense to be clarified below. Several applications and relations to other reduction of the Hamilton–Jacobi theory are shown in the last section of the paper. It is remarkable that as by-product we obtain a generalization of the Ge–Marsden reduction procedure [18] and the results in [17] . Quite surprisingly, the classical ansatze available in the literature to solve the Hamilton–Jacobi equation (see [2] , [19] ) are also particular instances of our framework.

In this work we present a model reduction procedure to derive a hybrid-dimensional framework for the mathematical modeling of reactive transport in fractured porous media. Fractures are essential pathways in the underground which allow fast circulation of the fluids present in the rock matrix, often characterized by low permeability. However, due to infilling processes fractures may change their hydraulic properties and become barriers for the flow and creating impervious blocks in the underground. The geometrical as well as the physical properties of the fractures require a special treatment to allow the subsequent numerical discretization to be affordable and accurate. The aim of this work is to introduce a simple yet complete mathematical model to account for such diagenetic effects where chemical reactions will occlude or empty portions of the porous media and, in particular, fractures.

In this paper we propose a stochastic model reduction procedure for deterministic equations from geophysical fluid dynamics. Once large-scale and small-scale components of the dynamics have been identified, our method consists in modelling stochastically the small scales and, as a result, we obtain that a transport-type Stratonovich noise is sufficient to model the influence of the small scale structures on the large scales ones. This work aims to contribute to motivate the use of stochastic models in fluid mechanics and identifies examples of noise of interest for the reduction of complexity of the interaction between scales. The ideas are presented in full generality and applied to specific examples in the last section.