bluuebunny/crossref_metadata_2025 huggingface dataset:
Algebraic families of groups and commuting involutions
Authors: Barbasch Dan , Higson Nigel , Subag Eyal
Published: March 2018

Let [Formula: see text] be a complex affine algebraic group, and let [Formula: see text] and [Formula: see text] be commuting anti-holomorphic involutions of [Formula: see text]. We construct an algebraic family of algebraic groups over the complex projective line and a real structure on the family that interpolates between the real forms [Formula: see text] and [Formula: see text].
Localizing virtual fundamental cycles for semi-perfect obstruction theories
Authors: Kiem Young-Hoon
Published: March 2018

Recently, Chang and Li generalized the theory of virtual fundamental class to the setting of semi-perfect obstruction theory. A semi-perfect obstruction theory requires only the local existence of a perfect obstruction theory with compatibility conditions. In this paper, we generalize the torus localization of Graber–Pandharipande [T. Graber and R. Pandharipande, Localization of virtual cycles, Invent. Math. 135(2) (1999) 487–518], the cosection localization [Y.-H. Kiem and J. Li, Localizing virtual cycles by cosections, J. Amer. Math. Soc. 26(4) (2013) 1025–1050] and their combination [H.-L. Chang, Y.-H. Kiem and J. Li, Torus localization and wall crossing for cosection localized virtual cycles, Adv. Math. 308 (2017) 964–986], to the setting of semi-perfect obstruction theory. As an application, we show that the Jiang-Thomas theory [Y. Jiang and R. Thomas, Virtual signed Euler characteristics, preprint (2014), arXiv:1408.2541] of virtual signed Euler characteristic works without the technical quasi-smoothness assumption from derived algebraic geometry.
W∗-superrigidity for coinduced actions
Authors: Drimbe Daniel
Published: March 2018

We prove W[Formula: see text]-superrigidity for a large class of coinduced actions. We prove that if [Formula: see text] is an amenable almost-malnormal subgroup of an infinite conjugagy class (icc) property (T) countable group [Formula: see text], the coinduced action [Formula: see text] from an arbitrary probability measure preserving action [Formula: see text] is W[Formula: see text]-superrigid. We also prove a similar statement if [Formula: see text] is an icc non-amenable group which is measure equivalent to a product of two infinite groups. In particular, we obtain that any Bernoulli action of such a group [Formula: see text] is W[Formula: see text]-superrigid.
Band head spin assignment of superdeformed bands in 133Pr using two-parameter formulae
Authors: Sharma Honey , Mittal H. M.
Published: March 2018

The two-parameter formulae viz. the power index formula, the nuclear softness formula and the VMI model are adopted to accredit the band head spin [Formula: see text] of four superdeformed rotational bands in [Formula: see text]. The technique of least square fitting is used to accredit the band head spin for four superdeformed rotational bands in [Formula: see text]. The root mean deviation among the computed transition energies and well-known experimental transition energies are attained by extracting the model parameters from the two-parameter formulae. The determined transition energies are in excellent agreement with the experimental transition energies, whenever exact spins are accredited. The power index formula coincides well with the experimental data and provides minimum root mean deviation. So, the power index formula is more efficient tool than the nuclear softness formula and the VMI model. The deviation of dynamic moment of inertia [Formula: see text] against the rotational frequency is also examined.
Spin and pseudospin towers of the Hubbard model on a bipartite lattice
Authors: Boretsky J. Z. , Cohn J. R. , Freericks J. K.
Published: March 2018

In 1989, Lieb proved two theorems about the Hubbard model. One showed that the ground state of the attractive model was a spin singlet state (S = 0) was unique and was positive definite. The other showed that the ground state of the repulsive model on a bipartite lattice at half-filling has a total spin given by [Formula: see text](N[Formula: see text]NB)/2[Formula: see text], corresponding to the difference of the number of lattice sites on the two sublattices divided by two. In the mid to late 1990s, Shen extended these proofs to show that the pseudospin of the attractive model was minimal until the electron number equaled 2NA where it became fixed at J = [Formula: see text](N[Formula: see text]NB)/2[Formula: see text] until the filling became 2NB, where it became minimal again. In addition, Shen showed that a spin tower exists for the spin eigenstates for the half-filled case on a bipartite lattice. The spin tower says the minimal energy state with spin S is higher in energy than the minimal energy state with spin S − 1 until we reach the ground-state spin given above. One long-standing conjecture about this model remains, namely, does the attractive model have such a spin tower for all fillings, which would then imply that the repulsive model has minimal pseudopsin in its ground state. While we do not prove this last conjecture, we provide a quick review of this previous work, provide a constructive proof of the pseudospin of the attractive model ground state, and describe the challenges by proving the remaining open conjecture.
How to pin down the pairing interaction for high Tc superconductivity in cuprates
Authors: Choi Han-Yong , Bok Jin Mo
Published: March 2018

The normal and pairing self-energies are the microscopic quantities which reflect and characterize the underlying interaction in superconductors. The momentum and frequency dependence of the self-energies, therefore, provides the experimental criteria which can single out the long sought-after pairing interaction among many proposed ideas. This line of research to pin down the pairing interaction for the cuprate superconductors has been carried out with some success by analyzing the momentum distribution curves (MDCs) of laser angle-resolved photo-emission spectroscopy (ARPES) data. Some progress and results are presented and compared with theoretical calculations based on leading proposals. Comments are made on the proposed scenarios from the comparisons.
A low temperature drift coefficient crystal-less frequency reference clock compensated by temperature sensor for microsystem
Authors: Gao Zhiqiang , Wu Ruixuan , Wang Yuteng , Gao Yuan , Liu Xiaowei , Zhu Jiaqi
Published: March 2018

Quartz oscillator has been widely used as reference clock source in the microsystems due to its good performance. But a good crystal oscillator costs too much and its bulky size is not desired. This paper aims at designing an alternative integrated oscillator to replace the external quartz oscillator. The proposed circuit used maneatis delay cell to construct a ring oscillator for its superior linear I–V characteristic. As for a frequency reference clock, its frequency stability over temperature is required at first. After detailed mathematical deducing and careful analysis, a formula is proposed to describe the relationship between desired control voltage and temperature by assuming the frequency as constant. This paper utilized bipolar transistor as the temperature sensor, combining it with CTAT current source and resistor to create a first-order temperature compensation control voltage. The chip with typical frequency of 10 MHz was fabricated in a 0.35 [Formula: see text]m CMOS technology and occupied 0.45 mm2. The measured results show that the frequency variation is ±0.2% for supply changes from 4.8 V to 5 V, and frequency variation is 48 ppm when the temperature change is from −40[Formula: see text]C to 85[Formula: see text]C, while the average current of the tested chip consumes 50 [Formula: see text]A from 5 V.
On the intersection of tame subgroups in groups acting on trees
Authors: Lentzos Konstantinos , Sykiotis Mihalis
Published: March 2018

Let [Formula: see text] be a group acting on a tree [Formula: see text] with finite edge stabilizers of bounded order. We provide, in some very interesting cases, upper bounds for the complexity of the intersection [Formula: see text] of two tame subgroups [Formula: see text] and [Formula: see text] of [Formula: see text] in terms of the complexities of [Formula: see text] and [Formula: see text]. In particular, we obtain bounds for the Kurosh rank [Formula: see text] of the intersection in terms of Kurosh ranks [Formula: see text] and [Formula: see text], in the case, where [Formula: see text] and [Formula: see text] act freely on the edges of [Formula: see text].
Intrinsically knotted and 4-linked directed graphs
Authors: Fleming Thomas , Foisy Joel
Published: March 2018

We consider intrinsic linking and knotting in the context of directed graphs. We construct an example of a directed graph that contains a consistently oriented knotted cycle in every embedding. We also construct examples of intrinsically 3-linked and 4-linked directed graphs. We introduce two operations, consistent edge contraction and H-cyclic subcontraction, as special cases of minors for digraphs, and show that the property of having a linkless embedding is closed under these operations. We analyze the relationship between the number of distinct knots and links in an undirected graph [Formula: see text] and its corresponding symmetric digraph [Formula: see text]. Finally, we note that the maximum number of edges for a graph that is not intrinsically linked is [Formula: see text] in the undirected case, but [Formula: see text] for directed graphs.
Splitting number of augmented links
Authors: Girao Darlan
Published: March 2018

We completely determine the splitting number of augmented links arising from knot and link diagrams in which each twist region has an even number of crossings. In the case of augmented links obtained from knot diagrams, we show that the splitting number is given by the size of a maximal collection of Boromean sublinks, any two of which have one component in common. The general case is stablished by considering the linking numbers between components of the augmented links. We also discuss the case when the augmented link arises from a link diagram in which twist regions may have an odd number of crossings.
INDEX OPTIONS AND VOLATILITY DERIVATIVES IN A GAUSSIAN RANDOM FIELD RISK-NEUTRAL DENSITY MODEL
Authors: HAN XIXUAN , WEI BOYU , YANG HAILIANG
Published: March 2018

We propose a risk-neutral forward density model using Gaussian random fields to capture different aspects of market information from European options and volatility derivatives of a market index. The well-structured model is built in the framework of the Heath–Jarrow–Morton philosophy and the Musiela parametrization with a user-friendly arbitrage-free condition. It reduces to the popular geometric Brownian motion model for the spot price of the market index and can be intuitively visualized to have a better view of the market trend. In addition, we develop theorems to show how the model drives local volatility and variance swap rates. Hence, volatility futures and options can be priced taking the forward density implied by European options as the initialization input. The model can be accordingly calibrated to the market prices of these volatility derivatives. An efficient algorithm is developed for both simulating and pricing, and a numerical study is conducted using real market data.
The linearity of the Mitchell order
Authors: Goldberg Gabriel
Published: March 2018

We show from an abstract comparison principle (the Ultrapower Axiom) that the Mitchell order is linear on sufficiently strong ultrafilters: normal ultrafilters, Dodd solid ultrafilters, and assuming GCH, generalized normal ultrafilters. This gives a conditional answer to the well-known question of whether a [Formula: see text]-supercompact cardinal [Formula: see text] must carry more than one normal measure of order 0. Conditioned on a very plausible iteration hypothesis, the answer is no, since the Ultrapower Axiom holds in the canonical inner models at the finite levels of supercompactness.
Local types of Prüfer rings
Authors: Klingler Lee , Lucas Thomas G. , Sharma Madhav
Published: March 2018

Earlier papers by Glaz, Boynton, and the authors established hierarchies of properties for commutative rings in general which become equivalent to “Prüfer domain” for integral domains. Between Gaussian rings and Prüfer rings, these papers considered locally (respectively, maximally) Prüfer (respectively, strong Prüfer) rings. In this paper, we refine these hierarchies still further by considering the restriction of these local conditions to just the regular (respectively, semiregular) prime (respectively, maximal) ideals of the ring. In addition, we also consider these local conditions for [Formula: see text]-Prüfer rings. This refinement leads to a hierarchy of 21 conditions between locally strong Prüfer rings and Prüfer rings, of which 17 are inequivalent. We also determine the extent to which these conditions pass between a ring and its total quotient ring.
New algebraic properties of quadratic quotients of the Rees algebra
Authors: D’Anna Marco , Strazzanti Francesco
Published: March 2018

We study some properties of a family of rings [Formula: see text] that are obtained as quotients of the Rees algebra associated with a ring [Formula: see text] and an ideal [Formula: see text]. In particular, we give a complete description of the spectrum of every member of the family and describe the localizations at a prime ideal. Consequently, we are able to characterize the Cohen–Macaulay and Gorenstein properties, generalizing known results stated in the local case. Moreover, we study when [Formula: see text] is an integral domain, reduced, quasi-Gorenstein, or satisfies Serre’s conditions.
Finitely projective modules with respect to a semidualizing module
Authors: Mao Lixin
Published: March 2018

Let [Formula: see text] be a commutative ring. We define and study [Formula: see text]-projective modules with respect to a semidualizing [Formula: see text]-module [Formula: see text], which are called [Formula: see text]–[Formula: see text]-projective modules. As consequences, we characterize several rings such as [Formula: see text]-coherent rings and Artinian rings using [Formula: see text]–[Formula: see text]-projective modules. Some known results are extended.
Conjugate real classes in general linear groups
Authors: Gongopadhyay Krishnendu , Mazumder Sudip , Sardar Sujit Kumar
Published: March 2018

Let [Formula: see text] be a field with a nontrivial involution [Formula: see text]. An element [Formula: see text] is called [Formula: see text]-real if it is conjugate to [Formula: see text]. We prove that for [Formula: see text], [Formula: see text] is [Formula: see text]-real if and only if it has a representation in some unitary group of degree [Formula: see text] over [Formula: see text].
Neutron Irradiation, Amorphous Transformation and Agglomeration Effects on the Permittivity of Nanocrystalline Silicon Carbide (3C-SiC)
Authors: Huseynov Elchin M.
Published: March 2018

Nanocrystalline 3C-SiC is irradiated by neutron flux ([Formula: see text][Formula: see text]n/cm2s) up to 20[Formula: see text]h in the TRIGA Mark II type research reactor. At the first stage, silicon carbide nanoparticles were analyzed by scanning electron microscope (SEM) and transmission electron microscope (TEM) devices before and after neutron irradiation. Amorphous transformation and agglomeration effects on the permittivity of nanocrystalline silicon carbide (3C-SiC) were comparisons investigated before and after neutron irradiation. Dielectric spectroscopies of nanocrystalline 3C-SiC have been conducted at the frequency ranges of 0.1[Formula: see text]Hz–2.5[Formula: see text]MHz and temperature ranges of 100–400[Formula: see text]K. Real and imaginary parts of the permittivity of the nanomaterial were analyzed for comparison before and after neutron irradiation. Neutron irradiation increased dopant elements concentration in the nanocrystalline 3C-SiC particles, and that directly affects dielectric polarization and increased permittivity. All the mechanisms of the observed effects are given in the work.
Graphene Decorated with Hierarchical CuS Nanoplates: Enhanced Photocatalytic Performance
Authors: Zeng Bin , Liu Wanfeng , Zeng Wujun , Jin Can
Published: March 2018

Graphene decorated with hierarchical CuS nanoplates (CuS NP-G) was synthesized using a microwave method to be used as a photocatalytic material. The incorporation of graphene into hierarchical CuS nanoplates was confirmed by structural, morphological and optical characterizations. The photocatalytic performance of the nanocomposite was evaluated. This study confirmed that the introduction of graphene was an effective way not only to improve the structural stability and service durability of the composite, but also to improve its solar photocatalytic activity by promoting the electron transfer and charge separation of hierarchical CuS nanoplates.
Solvothermal-Assisted Synthesis of Biomass Carbon Quantum Dots/Bismuth Oxyiodide Microflower for Enhanced Photocatalytic Activity
Authors: Yao Xin , Ma Changchang , Huang Hai , Zhu Zhi , Dong Hongjun , Li Chunxiang , Zhang Wenli , Yan Yongsheng , Liu Yang
Published: March 2018

In this paper, the biomass carbon quantum dots (CQDs) modified flower-like BiOI (CQDs/BiOI) composite photocatalyst was synthesized by a facile solvothermal method. Compared with the pristine BiOI, the biomass CQDs/BiOI exhibited outstanding photocatalytic activity for degradation of the typical methylene blue (MB) under visible light irradiation since the biomass CQDs could act as electron acceptors to effectively facilitate the separation efficiency of photon-generated carriers and prolong their lifetime. Furthermore, the mechanism detection experiment showed that the [Formula: see text] and H[Formula: see text] were major activity species, and the photocatalytic electron transfer mechanism was further investigated. This work provided a new insight into biomass CQDs effects and took an important step toward the development of improving Bi-based semiconductor photocatalyst activity.
Influence of Cu Content on the Microstructure, Mechanical, and Tribological Properties of ZrN–Cu Films
Authors: Chen Tong , Yu Lihua , Ju Hongbo , Xu Junhua , Koyama Shinji
Published: March 2018

A series of ZrN–Cu nano-composite films were deposited using the RF magnetron sputtering system. The microstructure, mechanical properties and tribological properties were investigated. The results showed that ZrN–Cu films were composed of face-centered cubice (fcc)-ZrN and face-centered cubic (fcc)-Cu. With the increase of Cu content, the hardness of ZrN–Cu composite film increased slowly first and then decreased rapidly. The maximum hardness value was 34.6[Formula: see text]GPa at 16[Formula: see text]at.% Cu. At room temperature, the coefficient of friction (Cof.) of ZrN–Cu films were lower than the ZrN film. When the content of Cu was lower than 39[Formula: see text]at.%, the wear rate of ZrN–Cu films were lower than the ZrN film. When the temperature of tribological testing was between 200–700[Formula: see text]C, the Cof. of ZrN–Cu films at 16[Formula: see text]at.% Cu were lower than ZrN film, while the wear rates were higher than the ZrN film. In summary, the addition of Cu improved the hardness and tribological properties of the ZrN–Cu film at room temperature, and decreased the Cof. of the ZrN-Cu during 200–700[Formula: see text]C.
Synchronized bioluminescence behavior of a set of fireflies involving fractional operators of Liouville–Caputo type
Authors: Escalante-Martínez J. E. , Gómez-Aguilar J. F. , Calderón-Ramón C. , Aguilar-Meléndez A. , Padilla-Longoria P.
Published: March 2018

In this paper, a system of fractional differential equations that model the synchronized bioluminescence behavior of a set of fireflies put on two spatial arrangements is presented; the alternative representation of these equations contains fractional operators of Liouville–Caputo type. The objective of the model is to qualitatively recover synchronization and show that it is persistent. It is shown that the effort made by each firefly glow changes with respect to the number of male competitors and the distance between them. The conditions on biological parameters are interpreted.
DNA cyclic codes over the ring 𝔽2[u,v]/〈u2 − 1,v3 − v,uv − vu〉
Authors: Dinh Hai Q. , Singh Abhay Kumar , Pattanayak Sukhamoy , Sriboonchitta Songsak
Published: March 2018

In this paper, our main objective is to find out the necessary and sufficient conditions for a cyclic code of arbitrary length over the ring of four elements [Formula: see text] [Formula: see text] to be a reversible cyclic code. We also obtain the structure of cyclic DNA codes of odd length over the ring [Formula: see text], which plays an important role in Computational Biology. Furthermore, we establish a direct link between the elements of ring [Formula: see text] and 64 codons used in the amino acids of living organisms by introducing a Gray map from [Formula: see text] to [Formula: see text]. Among others, binary images of cyclic codes over [Formula: see text] are also investigated. As applications, some cyclic DNA codes over [Formula: see text] using the Gray map are provided.
Global asymptotic stability for a SEI reaction–diffusion model of infectious diseases with immigration
Authors: Abdelmalek Salem , Bendoukha Samir
Published: March 2018

This paper studies the local and global stability of solutions for a spatially spread SEI epidemic model with immigration of individuals using a Lyapunov functional. It is shown that in the presence of diffusion, the unique steady state remains globally stable. Numerical results obtained through Matlab simulations are presented to confirm the findings of this study.
Parameter identification through mode isolation for reaction–diffusion systems on arbitrary geometries
Authors: Murphy Laura , Venkataraman Chandrasekhar , Madzvamuse Anotida
Published: March 2018

We present a computational framework for isolating spatial patterns arising in the steady states of reaction–diffusion systems. Such systems have been used to model many natural phenomena in areas such as developmental and cancer biology, cell motility and material science. In many of these applications, often one is interested in identifying parameters which will lead to a particular pattern for a given reaction–diffusion model. To attempt to answer this, we compute eigenpairs of the Laplacian on a variety of domains and use linear stability analysis to determine parameter values for the system that will lead to spatially inhomogeneous steady states whose patterns correspond to particular eigenfunctions. This method has previously been used on domains and surfaces where the eigenvalues and eigenfunctions are found analytically in closed form. Our contribution to this methodology is that we numerically compute eigenpairs on arbitrary domains and surfaces. Here we present examples and demonstrate that mode isolation is straightforward especially for low eigenvalues. Additionally, we show that in some cases the inhomogeneous steady state can be a linear combination of eigenfunctions. Finally, we show an example suggesting that pattern formation is robust on similar surfaces in cases that the surface either has or does not have a boundary.
Performance Enhancement of Window-Type Air-Conditioning Units
Authors: Shaker Al-Sayyab Ali K.
Published: March 2018

In this work, the performance of window-type air-conditioning units was improved. The study was achieved by adding a diffuser at the compressor outlet. An experimental investigation was carried out on 2 RT window-type air-conditioning units with controlled environmental zones. According to the compressor-outlet conditions, an ANSYS-fluent program was used to achieve a suitable diffuser geometry for maximum pressure increase. The refrigeration cycle model was programmed in Engineering Equation Solver (EES). The experimental work shows that using a diffuser of (5[Formula: see text]mm ID [Formula: see text] 9[Formula: see text]mm OD [Formula: see text] 12[Formula: see text]mm L) in an air-conditioning system will decrease the required compressor pressure ratio by 6% from the base case with an overall pressure increase of 1.4 bar and a 29% COP increase from the base case[Formula: see text]
Model Averaging and Input Transformation for 3D Needle Steering
Authors: Fallahi Bita , Sloboda Ron , Usmani Nawaid , Tavakoli Mahdi
Published: March 2018

In this paper, a duty-cycle-based method is proposed for needle steering in 3D. The paper models the continuous 3D needle steering problem as a four-mode switching system and provides a new average-based formulation to transform the continuous input into a switching sequence. In this structure, the needle tip deflection control system is decomposed to two different 2D subsystems. Each subsystem has its own input, for which a controller can be designed to adjust a switching duty cycle. The duty cycles from the two subsystems are then combined to provide an axial needle rotation command to control the needle deflection in 3D. In order to show the application of the proposed formulation, robust sliding mode technique is employed to design controllers for each subsystem and, thus for the total system in 3D. The controllers are designed to be robust with respect to uncertainties in the value of the needle path curvature and to deal with measurement limitations. The performance of the proposed framework is shown by performing experiments in different scenarios.
On the reliability of experimental data in the geomechanical characterization of dimension stones
Authors: Angrisani A. C. , Di Martire D. , Calcaterra D. , de'Gennaro M. , Ramondini M.
Published: March 2018

In the last 40 years different procedures to estimate standard properties of dimension stones have been proposed by Italian and European technical committees as well as by international associations. The introduction of numerous and different standards, based on different sampling and testing conditions, has produced many practical consequences over the years, such as the doubtful reliability of results from the tests. This paper deals with this issue, analysing the differences between uniaxial compressive strength values of a Miocene limestone from the Central–Southern Apennines, Italy, calculated with four different standard procedures and evaluating the effects of loading rate, environmental conditions, specimen size and shape on the measured values. An additional finding of this study is a specific correlation between uniaxial compressive strength data and the size-corrected point load strength index. Although there are several studies asserting that point load test is an attractive alternative for indirect uniaxial compressive strength evaluation, there are many variables affecting this correlation, as shown by the high variability of results reported in the literature.
Overburden movement characteristics of top-coal caving mining in multi-seam areas
Authors: Zhu Zhijie , Zhang Hongwei , Nemcik Jan , Lan Tianwei , Han Jun , Chen Ying
Published: March 2018

The fully mechanized top-coal caving mining method was used to mine the 15 m thick No. 3–5 seam at a depth of 450 m in Tongxin mine, located in the Datong area, China. The seam was overlain with strong strata that are hard to cave and four partially mined coal seams. Excessive mine roadway closure and severe ground conditions at the longwall face and the tailgate were induced by periodic weighting and remnant coal pillars left in the four mined coal seams above. These ground conditions were studied using physical modelling and microseismic monitoring. The results indicated that hard rock strata above the coal seam did not cave readily, causing minor and major face loading events. The ground conditions deteriorated when mining was undertaken below the remnant pillars left in the four upper Jurassic seams. In addition, the physical model showed overlying longwall goaf collapse reaching the upper goafs and causing global movement in the strata. The data from the physical model and the underground microseismic survey presented here agreed closely with the visual observations and reported events that occurred at the underground longwall face in Tongxin coal mine. Overall, this study demonstrated the mechanisms of the overburden strata movement, longwall weighting occurrences and deteriorating ground conditions along the longwall face and the tailgate roadway when mining was undertaken under the overlapped Jurassic remnant coal pillars. Methods to minimize these bad ground conditions were suggested, using stress relief hydraulic fracturing methods and blasting, such as pre-splitting and softening of coal pillars and roof strata in key places. A design of small coal pillars <3–5 m in size were recommended for overlying seams to minimize stress concentrations in seams below.
The influence of geological conditions on erosion of unlined spillways in rock
Authors: Douglas Kurt , Pells Steven , Fell Robin , Peirson William
Published: March 2018

Erosion in 33 unlined spillways in rock has been studied for dams in Australia, South Africa and the USA. Geological factors which influence the amount of erosion have been identified using published and project data and spillway site inspections by the authors. These are the orientation, persistence, spacing and nature of rock defects including bedding partings, joints, foliation and shears. The presence of kinematically viable blocks which can be detached and the persistence of the basal defect for these blocks are the most important factors.

Where spillways discharge on to a natural slope the presence of valley stress relief features, such as sheet joints parallel to the slope, or kinematically viable blocks, often with open sub-vertical defects, can lead to significant erosion even with small spillway discharges. The mechanism can be one of slope instability rather than erosion as water pressure destabilizes the slope.

A rock mass characterization index, the ‘Rock Mass Erodibility Index’ (RMEI), which considers spillway flow conditions and erosion mechanisms, has been developed. It can be used as a guide to spillway erosion and, when coupled with stream power for spillway flows, provides a method for preliminary assessments of likely amounts of spillway erosion.
From Multiscale to Mesoscience: Addressing Mesoscales in Mesoregimes of Different Levels
Authors: Li Jinghai , Huang Wenlai
Published: March 2018

This review covers three decades of research on mesoscale phenomena in chemical engineering, from the energy minimization multiscale (EMMS) model specific for gas–solid fluidization to a general principle of compromise in competition between dominant mechanisms, leading to the proposed concept of mesoscience. First, the concept of mesoscales is reviewed with respect to their commonality, diversity, and misunderstanding in different fields. Then, the evolution from the EMMS model to the EMMS principle common to all mesoscales is described to show the rationale of mesoscience referring to both mesoscales and mesoregimes. Finally, the potential universality of mesoscience and its importance, particularly to enable virtual process engineering (VPE) by realizing the consistency of logic and structure between the problem, the model, the software, and the computer, are discussed. The review concludes by illustrating possible case studies to collect more evidence and a potential framework for mesoscience.
On the Uniqueness of the Fock Quantization of the Dirac Field in the Closed FRW Cosmology
Authors: Cortez Jerónimo , Inácio Rodrigues Ilda , Martín-Benito Mercedes , Velhinho José
Published: March 2018

The Fock quantization of free fields propagating in cosmological backgrounds is in general not unambiguously defined due to the nonstationarity of the space-time. For the case of a scalar field in cosmological scenarios, it is known that the criterion of unitary implementation of the dynamics serves to remove the ambiguity in the choice of Fock representation (up to unitary equivalence). Here, applying the same type of arguments and methods previously used for the scalar field case, we discuss the issue of the uniqueness of the Fock quantization of the Dirac field in the closed FRW space-time proposed by D’Eath and Halliwell.
Antimicrobial Photodynamic Activity of Phthalocyanine Derivatives
Authors: Nyamu Samuel N. , Ombaka Lucy , Masika Eric , Ng’ang’a Margaret
Published: March 2018

Microbial pathogens have increasingly shown multidrug resistance posing a serious threat to the public health. Advances in technology are opening novel avenues for discovery of compounds that will mitigate the ever-increasing drug-resistant microbes. Use of photodynamic photosensitizer is one of the promising alternative approaches since they offer low risk of bacteria resistance as they use generated reactive oxygen species to kill the microbes. Phthalocyanine (Pc) is one such photosensitizer which has already shown promising antimicrobial photodynamic therapeutic properties. Previous studies have shown effectiveness of the Pc against Gram-positive bacteria. However, its effectiveness toward Gram-negative bacteria is limited by the impermeability of the bacteria’s outer membrane which is made up of lipopolysaccharides layer. The effectiveness of this photosensitizer is determined by its photophysical and photochemical properties such as singlet/triplet lifetimes, singlet oxygen quantum yields, and fluorescence quantum yield. Therefore, this review focuses on the recent significance advances on designing Pc that have this improved property by either conjugating with nanoparticles, quantum dots, functional groups in peripheral position, considering effect of cationic charge, and its position on the macrocycle.
Generalized Euler-Lagrange Equations for Fuzzy Fractional Variational Problems under gH-Atangana-Baleanu Differentiability
Authors: Zhang Jianke , Wang Gaofeng , Zhi Xiaobin , Zhou Chang
Published: March 2018

We study in this paper the Atangana-Baleanu fractional derivative of fuzzy functions based on the generalized Hukuhara difference. Under the condition of gH-Atangana-Baleanu fractional differentiability, we prove the generalized necessary and sufficient optimality conditions for problems of the fuzzy fractional calculus of variations with a Lagrange function. The new kernel of gH-Atangana-Baleanu fractional derivative has no singularity and no locality, which was not precisely illustrated in the previous definitions.
Stress-Adaptive Responses Associated with High-Level Carbapenem Resistance in KPC-ProducingKlebsiella pneumoniae
Authors: Adams-Sapper Sheila , Gayoso Adam , Riley Lee. W.
Published: March 2018

Carbapenem-resistant Enterobacteriaceae (CRE) organisms have emerged to become a major global public health threat among antimicrobial resistant bacterial human pathogens. Little is known about how CREs emerge. One characteristic phenotype of CREs is heteroresistance, which is clinically associated with treatment failure in patients given a carbapenem. Throughin vitrowhole-transcriptome analysis we tracked gene expression over time in two different strains (BR7, BR21) of heteroresistant KPC-producingKlebsiella pneumoniae,first exposed to a bactericidal concentration of imipenem followed by growth in drug-free medium. In both strains, the immediate response was dominated by a shift in expression of genes involved in glycolysis toward those involved in catabolic pathways. This response was followed by global dampening of transcriptional changes involving protein translation, folding and transport, and decreased expression of genes encoding critical junctures of lipopolysaccharide biosynthesis. The emerged high-level carbapenem-resistant BR21 subpopulation had a prophage (IS1) disruptingompK36associated with irreversible OmpK36 porin loss. On the other hand, OmpK36 loss in BR7 was reversible. The acquisition of high-level carbapenem resistance by the two heteroresistant strains was associated with distinct and shared stepwise transcriptional programs. Carbapenem heteroresistance may emerge from the most adaptive subpopulation among a population of cells undergoing a complex set of stress-adaptive responses.
Investigation of Relation between Fracture Scale and Acoustic Emission Time‐Frequency Parameters in Rocks
Authors: Zhang Junwen
Published: March 2018

To investigate relation between fracture scale and acoustic emission time‐frequency parameters in rocks, experiments of acoustic emission monitoring of granite uniaxial compression were carried out. The AE signal energy and dominant‐frequency of granite fracture process were extracted by means of AE time‐frequency analysis. The relation between fracture scale and AE time‐frequency parameters (energy and frequency) in granite fracture process was analyzed. The evaluation model of rock fracture scale based on AE energy and dominant‐frequency was established by using the intrinsic relation between the scale of rock fracture and the time‐frequency parameters of rock mass. The evolution of crack scale in the process of uniaxial compression was analyzed based on the evaluation model of rock fracture scale. Results show that the AE energy and the dominant‐frequency can reflect the crack scale inside the rock. The scale of rock fracture is proportional to the AE energy, which is inversely proportional to the AE dominant‐frequency. Signals with low frequency and high energy usually represent large‐scale cracks. On the contrary, if the high frequency has low energy value, it indicates a small‐scale crack. The theory and method of evaluation of rock rupture scale based on AE time‐frequency information (energy, frequency) can describe the failure process of rock crack scale variation characteristics. It provides a way and method for investigating the characterization of fracture size evolution process of rock fracture.
Adoptive Cell Therapy with Tumor-Infiltrating Lymphocytes in Advanced Melanoma Patients
Authors: Saint-Jean Mélanie , Knol Anne-Chantal , Volteau Christelle , Quéreux Gaëlle , Peuvrel Lucie , Brocard Anabelle , Pandolfino Marie-Christine , Saiagh Soraya , Nguyen Jean-Michel , Bedane Christophe , Basset-Seguin Nicole , Khammari Amir , Dréno Brigitte
Published: March 2018

Immunotherapy for melanoma includes adoptive cell therapy with autologous tumor-infiltrating lymphocytes (TILs). This monocenter retrospective study was undertaken to evaluate the efficacy and safety of this treatment of patients with advanced melanoma. All advanced melanoma patients treated with TILs using the same TIL expansion methodology and same treatment interleukin-2 (IL-2) regimen between 2009 and 2012 were included. After sterile intralesional excision of a cutaneous or subcutaneous metastasis, TILs were produced according to a previously described method and then infused into the patient who also received a complementary subcutaneous IL-2 regimen. Nine women and 1 man were treated for unresectable stage IIIC (n=4) or IV (n=6) melanoma. All but 1 patient with unresectable stage III melanoma (1st line) had received at least 2 previous treatments, including anti-CTLA-4 antibody for 4. The number of TILs infused ranged from 0.23 × 109to 22.9 × 109. Regarding safety, no serious adverse effect was reported. Therapeutic responses included a complete remission, a partial remission, 2 stabilizations, and 6 progressions. Among these 4 patients with clinical benefit, 1 is still alive with 9 years of follow-up and 1 died from another cause after 8 years of follow-up. Notably, patients treated with high percentages of CD4 + CD25 + CD127lowFoxp3+ T cells among their TILs had significantly shorter OS. The therapeutic effect of combining TILs with new immunotherapies needs further investigation.
Morphological Biomarker Differentiating MCI Converters from Nonconverters: Longitudinal Evidence Based on Hemispheric Asymmetry
Authors: Long Xiaojing , Jiang Chunxiang , Zhang Lijuan
Published: March 2018

Identifying subjects with mild cognitive impairment (MCI) who may probably progress to Alzheimer’s disease (AD) is important for better understanding the disease mechanisms and facilitating early treatments. In addition to the direct volumetric and thickness measurement based on high-resolution magnetic resonance imaging (MRI), hemispheric asymmetry could be a potential index to detect morphological variations in MCI patients with a high risk of conversion to AD. The present study collected a set of longitudinal MRI data from 53 MCI converters and nonconverters and investigated the asymmetry differences between groups. Asymmetry variation was observed in the medial temporal lobe, especially in the entorhinal cortex, between converters and nonconverters 3 years before the former developed AD. The proposed asymmetry analysis was observed to be sensitive to detect morphological changes between groups as compared to the methods of voxel-based morphometry (VBM) and thickness measurement. Hemispheric asymmetry in specific brain regions as a neuroimaging biomarker can provide helpful information for prediction of MCI conversion.
Thrombin Assessment on Nanostructured Label-Free Aptamer-Based Sensors: A Mapping Investigation via Surface-Enhanced Raman Spectroscopy
Authors: Scatena Elisa , Pascale Sara , Cairone Cristina , Fabbri Filippo , Del Gaudio Costantino
Published: March 2018

Aptamers, synthetic single-stranded DNA or RNA molecules, can be regarded as a valuable improvement to develop novel ad hoc sensors to diagnose several clinical pathologies. Their intrinsic potential is related to the high specificity and sensitivity to the selected target biomarkers, being capable of detecting very low concentrations and thus allowing an early diagnosis of a possible disease. This kind of probe can be usefully integrated into a number of different devices in order to provide a reliable acquisition of the analyte and properly elaborate the related signal. The study presents the fabrication and characterization of a label-free aptamer sensor designed using a gold-coated silicon nanostructured substrate to map the target molecule by means of surface-enhanced Raman spectroscopy (SERS). As a proof, thrombin was used as a model at four different concentrations (i.e., 0.0873, 0.873, 8.73, and 87.3 nM). SERS mapping analysis was carried out considering each representative band of the aptamer-thrombin complex (centered at 822, 1140, and 1558 cm−1) and then combining them in order to acquire a comprehensive and unambiguous measure of the target. In both cases, a valuable correlation was evaluated, even if the first approach can suffer from some limitations in the third band related to lower definition of the characteristic peak compared to those in the other two bands.
A Secure and Scalable Data Communication Scheme in Smart Grids
Authors: Hu Chunqiang , Liu Hang , Ma Liran , Huo Yan , Alrawais Arwa , Li Xiuhua , Li Hong , Xiong Qingyu
Published: March 2018

The concept of smart grid gained tremendous attention among researchers and utility providers in recent years. How to establish a secure communication among smart meters, utility companies, and the service providers is a challenging issue. In this paper, we present a communication architecture for smart grids and propose a scheme to guarantee the security and privacy of data communications among smart meters, utility companies, and data repositories by employing decentralized attribute based encryption. The architecture is highly scalable, which employs an access control Linear Secret Sharing Scheme (LSSS) matrix to achieve a role‐based access control. The security analysis demonstrated that the scheme ensures security and privacy. The performance analysis shows that the scheme is efficient in terms of computational cost.
Output Information Based Fault-Tolerant Iterative Learning Control for Dual-Rate Sampling Process with Disturbances and Output Delay
Authors: Tao Hongfeng , Liu Yan , Yang Huizhong
Published: March 2018

For a class of single-input single-output (SISO) dual-rate sampling processes with disturbances and output delay, this paper presents a robust fault-tolerant iterative learning control algorithm based on output information. Firstly, the dual-rate sampling process with output delay is transformed into discrete system in state-space model form with slow sampling rate without time delay by using lifting technology; then output information based fault-tolerant iterative learning control scheme is designed and the control process is turned into an equivalent two-dimensional (2D) repetitive process. Moreover, based on the repetitive process stability theory, the sufficient conditions for the stability of system and the design method of robust controller are given in terms of linear matrix inequalities (LMIs) technique. Finally, the flow control simulations of two flow tanks in series demonstrate the feasibility and effectiveness of the proposed method.
Silver Nanoparticles Obtained by Aqueous or Ethanolic Aloe vera Extracts: An Assessment of the Antibacterial Activity and Mercury Removal Capability
Authors: Vélez Ederley , Campillo Gloria , Morales Gladis , Hincapié César , Osorio Jaime , Arnache Oscar
Published: March 2018

Silver nanoparticles (AgNPs) were synthesized by chemical reduction of Ag+ ions (from silver nitrate AgNO3), using aqueous or ethanolic Aloe vera extracts as reducing, stabilizing, and size control agent. The nanoparticles’ sizes were between 2 and 7 nm for ethanolic extract and between 3 and 14 nm for aqueous extract, as measured by High-Resolution Transmission Electron Microscope (HRTEM). The antibacterial activity against a mesophilic microorganism, Kocuria varians, a Gram-positive coccus, was measured by counting bacterial colonies in agar plate for both extracts. We found that 4% effective concentration is the lowest concentration that completely inhibited visible growth. Mercury removal was investigated by Atomic Absorption Spectroscopy (AAS) measurements, where it was shown that it is not necessary to use high concentrations of nanoparticles for effective removal of mercury inasmuch as with a 20% V/V concentration of both extracts; the Hg(II) removal percentage was above 95%. These results show that the mercury remaining unremoved from the different essays is below the level allowed by World Health Organization (WHO) and the Environmental Protection Agency (EPA).
Drosophila as a Model System to Study Cell Signaling in Organ Regeneration
Authors: Ahmed-de-Prado Sara , Baonza Antonio
Published: March 2018

Regeneration is a fascinating phenomenon that allows organisms to replace or repair damaged organs or tissues. This ability occurs to varying extents among metazoans. The rebuilding of the damaged structure depends on regenerative proliferation that must be accompanied by proper cell fate respecification and patterning. These cellular processes are regulated by the action of different signaling pathways that are activated in response to the damage. The imaginal discs ofDrosophila melanogasterhave the ability to regenerate and have been extensively used as a model system to study regeneration. Drosophila provides an opportunity to use powerful genetic tools to address fundamental problems about the genetic mechanisms involved in organ regeneration. Different studies in Drosophila have helped to elucidate the genes and signaling pathways that initiate regeneration, promote regenerative growth, and induce cell fate respecification. Here we review the signaling networks involved in regulating the variety of cellular responses that are required for discs regeneration.