Regular Band Research Articles

Online Fault Detection Method for Steel Cord Conveyor Belt Using the Regularity Band

The X-ray images of steel cord conveyor belt are built on a repetitive unit of a pattern. Based on the statistical features and regularity analysis, a fast online automatic fault detection method named FRB (Fast Regular Band)was proposed to monitor the status of steel cord conveyor belt. Comparing with the MRB(Modified Regular Band)Method, FRB method is so fast that it can be used for the online fault detection for the steel cord conveyor belt especially when the image size is bigger than 600× 1216. And it doesn’t obviously decrease the accuracy of the identification.

Bistability suppression and low threshold switching using frozen light at a degenerate band edge waveguide

We predict that nonlinear waveguides which support frozen light associated with a degenerate photonic band edge, where the dispersion relation is locally quartic, exhibit a tunable, all-optical switching response. The thresholds for switching are orders-of-magnitude lower than at regular band edges. By adjusting the input condition, bistability can be eliminated, preventing switching hysteresis.

Influence of microcrystalline cellulose fiber (MCCF) on the morphology of poly(3-hydroxybutyrate) (PHB)

Biopolymer composites were prepared from poly(3-hydroxybutyrate) (PHB)/microcrystalline cellulose fiber (MCCF)/plastiziers/poly(vinyl acetate) by melt extrusion. The morphology, crystal structure, and non-isothermal crystallization of these composites were investigated by polarized optical microscopy (POM), differential scanning calorimetry, Fourier transform infrared spectrometer, and wide-angle X-ray diffraction. The results of DSC indicate that the addition of small amount of MCCF improved the crystallization rate. Non-isothermal crystallization shows that the composites 1 and 2 have lower crystallization half time (t 0 .5) than that of pure PHB. Higher MCCF contents in PHB (composite 4) lead to a decrease in the crystallization rate. POM micrographs show that the MCCF were well dispersed in the PHB matrix and served as a nucleating agent with a strong change in PHB morphology. Increasing the isothermal crystallization temperature above 120 °C, leads to the formation of banded spherulites with large regular band spacing. Decreasing the isothermal crystallization temperature below 100 °C produces more and small spherulites.

The effects of home exercise on insulin resistant in chronic kidney disease patients

Insulin resistance appears at an earlier stage of chronic kidney disease (CKD) and closely correlates with atherosclerosis and cardiovascular mortality. Exercise training may improve hyperinsulinemia in patients with chronic disease, but it has proven difficult to motivate many such patients to undergo exercise training chronically. We aimed to demonstrate the effect of regular home rubber band exercise on insulin resistant in patients with CKD stage 3-5.The randomized controlled trial was conducted in CKD clinic at Phramongkutklao hospital, Bangkok, Thailand, during June to December 2010. The eligible CKD stage 3-5 participants were asked to randomly assigned to do only home gentle exercise (control) or plus home resistance exercise by using rubber band (treatment) for 12 weeks. The exercise training was supervised and strictly monitored by sport scientist every four weeks. Fasting plasma glucose and insulin concentrations was performed to calculate homeostasis model assessment (HOMA). There were 21 patients in the control group (mean age 66.05±13.72 years) and 24 patients in the treatment group (mean age 66.05±13.72 years) . At the end of study, the fasting plasma glucose (-0.76±1.84 mmol/L) and HOMA-IR (-1.09±2.43) decreased significantly in the treatment group, whereas the fasting plasma glucose (0.49±1.65 mmol/L) and HOMA-IR (0.38±2.12) slightly increase significantly in the control group. In addition, there were significant different of HOMA-IR between the control group and the treatment group (1.9±1.85 vs 3.72±3.26, P= 0.031, respectively). Moreover, all patients in the treatment group did not have serious side effect from resistance exercise, but only five patients had muscle cramp. In conclusion, regular home exercise ameliorate insulin resistance without any serious adverse effects in the CKD population.

Magnetic rotation and quasicollective structures in58Fe: Influence of theνg9/2orbital

The structure of ${}^{58}$Fe was investigated at Gammasphere using ${}^{48}$Ca(${}^{13,14}$C,$x$$n$) fusion-evaporation reactions at a beam energy of 130 MeV. The level scheme has been revised and extended to $J\ensuremath{\sim}17\ensuremath{\hbar}$ and an excitation energy of 16.6 MeV. Regular band structures consisting of low-energy $\ensuremath{\Delta}J=1\ensuremath{\hbar}$ transitions have been observed at moderate spin ($J\ensuremath{\sim}8\ensuremath{\hbar}$--15$\ensuremath{\hbar}$) and are candidates for magnetic rotational bands. Self-consistent tilted-axis-cranking calculations within a relativistic mean-field theory were applied to investigate these bands and were found to reproduce the experimental results well. In other parts of the level scheme, quasirotational bands composed of stretched-$E2$ transitions have been extended to high spin, and other new bands have been identified. Positive-parity experimental states were compared to predictions of the spherical shell model using the GXPF1A, KB3G, and FPD6 effective interactions in the $fp$ model space. The projected shell model, with a deformed quasiparticle basis including the neutron $\ensuremath{\nu}{g}_{9/2}$ orbital, was applied to interpret regular $\ensuremath{\Delta}J=2\ensuremath{\hbar}$ band structures that extend beyond the maximum spin available for $\ensuremath{\pi}$[(${f}_{7/2}$)${}^{\ensuremath{-}2}$] $\ensuremath{\bigotimes}$ $\ensuremath{\nu}$[(${p}_{3/2}{f}_{5/2}{p}_{1/2}$)${}^{4}$] configurations and exhibit features characteristic of rotational alignment. It is clear that the $\ensuremath{\nu}{g}_{9/2}$ intruder orbital plays a crucial role in describing the quasirotational structures in this nucleus, even starting as low as $J\ensuremath{\sim}5\ensuremath{\hbar}$.

Slow and frozen light in optical waveguides with multiple gratings: Degenerate band edges and stationary inflection points

We show that a waveguide with multiple gratings can have a modal dispersion relation which supports frozen light. This means that light can be coupled efficiently to low group velocity modes of an optical waveguide or can even have finite coupling to zero group velocity modes. These effects are associated with stationary points in the dispersion of the form $\ensuremath{\omega}\ensuremath{-}{\ensuremath{\omega}}_{o}\ensuremath{\propto}{(k\ensuremath{-}{k}_{o})}^{m}$, for integer order $m>1$, around a center frequency ${\ensuremath{\omega}}_{o}$ and wave number ${k}_{o}$. Stationary points of any order can be created, not only regular band edges ($m=2$), but also degenerate band edges ($m>2$ and even) and stationary inflection points ($m$ odd). Using the perturbation theory of matrices in Jordan normal form, the modes and their properties are calculated analytically. Efficient coupling is shown to stem from evanescent modes which must accompany the presence of high-order stationary points with $m>2$.

Extensions and covers for semigroups whose idempotents form a left regular band

Proper extensions that are “injective on ℒ-related idempotents” of ℛ-unipotent semigroups, and much more generally of the class of generalised left restriction semigroups possessing the ample and congruence conditions, referred to here as glrac semigroups, are described as certain subalgebras of a λ-semidirect product of a left regular band by an ℛ-unipotent or by a glrac semigroup, respectively. An example of such is the generalized Szendrei expansion.

Giant resonances near the split band edges of two-dimensional photonic crystals

We conduct a numerical study on the giant optical resonances near the split photonic band edges of two-dimensional square lattices. Their quality factors are $1$ order of magnitude higher than those near the regular band edges. Such enhancement results from the efficient interference of multiple Bloch waves, which minimizes light leakage from the periodic pattern of finite size. The variation of the quality factor with the pattern size is nonmonotonic for the split band edge resonance, leading to an optimal size for the maximal quality factor.

The Quiver of an Algebra Associated to the Mantaci-Reutenauer Descent Algebra and the Homology of Regular Semigroups

We develop the homology theory of the algebra of a regular semigroup, which is a particularly nice case of a quasi-hereditary algebra in good characteristic. Directedness is characterized for these algebras, generalizing the case of semisimple algebras studied by Munn and Ponizovksy. We then apply homological methods to compute (modulo group theory) the quiver of a right regular band of groups, generalizing Saliola’s results for a right regular band. Right regular bands of groups come up in the representation theory of wreath products with symmetric groups in much the same way that right regular bands appear in the representation theory of finite Coxeter groups via the Solomon-Tits algebra of its Coxeter complex. In particular, we compute the quiver of Hsiao’s algebra, which is related to the Mantaci-Reutenauer descent algebra.

The endometrial–myometrial junction: a fresh look at a busy crossing

The endometrial–myometrial junction: a fresh look at a busy crossing

GENERALIZATION OF F-INVERSE SEMIGROUPS BY USING MCALISTER'S APPROACH

We generalize the F-inverse semigroups within the class of lpp-semigroups by using McAlister's approach and FGC-systems. Consider a left GC - lpp monoid M. If M is lpp, then M is called a left F-pseudo group and for brevity, we call the semi-direct product of a left regular band and a cancellative monoid a twisted left cryptic group. In this paper, the structures of left F-pseudo groups are investigated. It is shown that a left F-pseudo group whose minimum right cancellative monoid congruence is cancellative can be embedded into a twisted left cryptic group. This result generalizes a number of known results in F-inverse semigroups previously given by C. C. Edwards, R. B. McFadden, L. O'Carrol, X. J. Guo and others. In particular, a new method constructing F -right inverse semigroups is provided.

Numerical study of photonic crystals with a split band edge: Polarization dependence and sensitivity analysis

We examine photonic crystals (PhC) made of periodic stacks of anisotropic dielectric layers with a split band edge (SBE) on the band diagram. Just below the band edge frequency, the dispersion relation $\ensuremath{\omega}(k)$ of SBE PhCs can be approximated as a linear combination of a quadratic term and a quartic term. This is in contrast to regular (conventional) band edge PhCs, which produce a quadratic dispersion relation, and to degenerate band edge (DBE) PhCs, which produce a quartic dispersion relation. Finite-size DBE PhCs and SBE PhCs are of interest because they both can support slow-wave Fabry-Perot resonances with very good transmittance. One of the most significant differences between DBE and SBE is that the transmittance of the former depends on the incident wave polarization whereas in the latter it does not. In this work, we investigate the transmittance behavior of SBE PhCs and perform a sensitivity analysis of their responses against geometrical and/or material perturbations. Dielectric losses, thickness perturbations, and misalignment angle perturbations are considered. The analysis uses a full-wave numerical technique for transient Maxwell's equations in inhomogeneous anisotropic media based on a complex-envelope alternating-direction-implicit finite-difference time-domain. A comparison is also made between the sensitivity of the SBE PhCs response versus that of DBE PhCs.

Iron limitation in the marine cyanobacterium Trichodesmium reveals new insights into regulation of photosynthesis and nitrogen fixation

* As iron (Fe) deficiency is a main limiting factor of ocean productivity, its effects were investigated on interactions between photosynthesis and nitrogen fixation in the marine nonheterocystous diazotrophic cyanobacterium Trichodesmium IMS101. * Biophysical methods such as fluorescence kinetic microscopy, fast repetition rate (FRR) fluorimetry, and in vivo and in vitro spectroscopy of pigment composition were used, and nitrogenase activity and the abundance of key proteins were measured. * Fe limitation caused a fast down-regulation of nitrogenase activity and protein levels. By contrast, the abundance of Fe-requiring photosystem I (PSI) components remained constant. Total levels of phycobiliproteins remained unchanged according to single-cell in vivo spectra. However, the regular 16-kDa phycoerythrin band decreased and finally disappeared 16-20 d after initiation of Fe limitation, concomitant with the accumulation of a 20-kDa protein cross-reacting with the phycoerythrin antibody. Concurrently, nitrogenase expression and activity increased. Fe limitation dampened the daily cycle of photosystem II (PSII) activity characteristic of diazotrophic Trichodesmium cells. Further, it increased the number and prolonged the time period of occurrence of cells with elevated basic fluorescence (F(0)). Additionally, it increased the effective cross-section of PSII, probably as a result of enhanced coupling of phycobilisomes to PSII, and led to up-regulation of the Fe stress protein IsiA. * Trichodesmium survives short-term Fe limitation by selectively down-regulating nitrogen fixation while maintaining but re-arranging the photosynthetic apparatus.

Photonic crystals with a degenerate band edge: Field enhancement effects and sensitivity analysis

Photonic crystals (PhCs) with a degenerate band edge (DBE) are dispersion-tailored materials composed of a periodic arrangement of misaligned anisotropic dielectric layers and an isotropic dielectric layer. DBE PhCs yield an (approximately) quartic dispersion relation just below the DBE frequency rather than the conventional quadratic dispersion relation present below a regular band edge (RBE). We present a sensitivity analysis of the performance of DBE PhCs under various perturbations. This analysis is made possible by means of an unconditionally stable finite-difference time-domain scheme to solve Maxwell's equations in anisotropic media based on a complex-envelope alternating-direction-implicit algorithm. Numerical simulations are performed to examine the gigantic field intensity enhancement at Fabry-Perot resonances associated with finite-stack DBE PhCs. Numerical simulations are also used to investigate the sensitivity of field enhancement effects against the bandwidth of the excitation. The effects of layer thickness perturbations, grounding, and dielectric losses on the electromagnetic response of DBE PhCs are also examined. The numerical results are used to compare Fabry-Perot RBE resonances against Fabry-Perot DBE resonances.

Wreath Product Structure of Left C-rpp Semigroups

The concept of wreath product of semigroups was first introduced by Neumann in 1960, and later on, this concept was used by Preston to investigate the structure of some inverse semigroups. In this paper, we modify the wreath product given by Neumann and Preston to study the structure of some generalized Clifford semigroups. In particular, we prove that a semigroup is a left C-rpp semigroup if and only if it is the wreath product of a left regular band and a C-rpp semigroup. Our result provides a new insight to the structure of left C-rpp semigroups.

THE QUIVER OF THE SEMIGROUP ALGEBRA OF A LEFT REGULAR BAND

Recently it has been noticed that many interesting combinatorial objects belong to a class of semigroups called left regular bands, and that random walks on these semigroups encode several well-known random walks. For example, the set of faces of a hyperplane arrangement is endowed with a left regular band structure. This paper studies the module structure of the semigroup algebra of an arbitrary left regular band, extending results for the semigroup algebra of the faces of a hyperplane arrangement. In particular, a description of the quiver of the semigroup algebra is given and the Cartan invariants are computed. These are used to compute the quiver of the face semigroup algebra of a hyperplane arrangement and to show that the semigroup algebra of the free left regular band is isomorphic to the path algebra of its quiver.

Dual Wreath Product Structure of Right C-rpp Semigroups

The concept of wreath product of semigroups was initiated by Neumann in 1960, and later on, his concept was used by Preston to investigate the structure of some inverse semigroups. Recently, we start to investigate the structure of left C-rpp semigroups by using wreath products. In this paper, we modify the wreath product to “dual wreath product” so that we can study the structure of right C-rpp semigroups. We prove that a semigroup is a right C-rpp semigroup if and only if it is the dual wreath product of a right regular band and a C-rpp semigroup. Our theorem provides new insight to the structure of right C-rpp semigroups. In particular, a recent result given by Ren and Shum for right C-rpp semigroups is strengthened and enriched.

Fixation of the Access-Port is Not Required in Gastric Banding

Laparoscopic adjustable gastric banding (LAGB) is increasingly performed in patients with morbid obesity. Suturing of the access-port in LAGB can be difficult and time consuming but is felt necessary by many surgeons to prevent migration and facilitate band adjustments. Between 2003 and 2006, 226 patients underwent LAGB with the MIDband. All surgery was performed by the pars flaccida approach. The access-port was positioned in a subcutaneous pouch adjacent to the left hypochondrial port site and was not secured. Regular follow-up and band fills were offered. All band or port-related complications were duly recorded. A patient satisfaction survey was also conducted among 50 randomly selected post-banding patients. Mean age was 41.65 years (range 18-73 years) and mean BMI was 45.85 kg/m2 (range 34.0-74.93 kg/m2). The access-port was inaccessible at first attempt in 5 (2%) patients. 4 of these required radiological imaging to identify the port orientation and 1 required multiple attempts at port puncture with subsequent re-operation due to tube puncture. 91% of patients reported no significant trouble other than mild discomfort and prominence of the port. This study shows non-fixation of the access-port to be safe and effective with good patient acceptability. In addition, it avoids the need for regular X-ray localization of the port.

On the structure of semigroups of idempotent matrices

We prove that any pure regular band of matrices admits a simultaneous LU decomposition in the standard form. In case that such a band forms a double band called a skew lattice, we obtain the standard form without the assumption of purity.

Comprehensive two-dimensional liquid chromatography with parallel gradients for separation of phenolic and flavone antioxidants

Various combinations of PEG–silica, phenyl–silica and C18 columns in a single-column or serial (tandem) arrangement in the first dimension and a monolithic Chromolith column in the second dimension were tested for comprehensive two-dimensional (2D) LC × LC separation of phenolic and flavone natural antioxidants. The combinations of different stationary phase chemistries provided low selectivity correlations between the first-dimension and the second-dimension separation systems. Improvement in system orthogonality, bandwidths suppression, more regular band distribution over the whole 2D retention plane and increased peak capacity in different 2D setups was achieved by using gradients with matching profiles running in parallel in the two dimensions over the whole 2D separation time range. Instead of two sampling loops, two alternating trapping XTerra columns were used for sample fraction transfer from the first-dimension column to the second dimension. Stronger retention on the XTerra columns in comparison to PEG–silica or phenyl–silica columns in the first dimension allowed using focusing of sample fractions in narrow zones on the top of a trapping column and back-flushing into the second dimension in a very low volume of the mobile phase. This fraction transfer modulation provided significant bandwidth suppression in the second dimension. 2D systems with optimized stationary phase selectivity, parallel gradients and fraction transfer modulation using two trapping columns were applied for the analysis of natural antioxidants in beer and wine samples.