V-shaped Structure Research Articles

Dipeptides from lactiplantibacillus plantarum limit Pseudomonas aeruginosa pathogenesis.

Lactobacilli have drawn a great deal of attention due to the heterogeneity of their cells, as well as their remarkable ability to adapt to a range of harsh conditions. One such adaptation response by Lactiplantibacillus plantarum was forming a V-shaped cell structure in low acidic pH conditions. This study aims to identify low pH induced-biofilm formation in L. plantarum and Limosilactobacillus reuteri and their antagonistic interactions with an opportunistic pathogen, Pseudomonas aeruginosa PAO1. Dual species bacterial interactions revealed a Lactobacilli biofilm-mediated suppression of PAO1 biofilms and pyocyanin pigment. Furthermore, filtrates from Lactobacilli grown at low acidic pH (pH 3.5) effectively arrest the pathogenesis of P. aeruginosa PAO1 including biofilm, swarming motility, and pyocyanin formation. Liquid chromatography-mass spectroscopy analysis revealed the presence of several Lactobacilli secreted metabolites and dipeptides that exhibited strong LasR receptor antagonistic interactions in molecular docking analysis. Prolyl-tyrosine showed the best lasR antagonistic and PAO1 biofilm inhibitory activities of the identified dipeptides. Overall, the results will contribute to the development of anti-infective drugs against P. aeruginosa using Lactobacilli secreted dipeptides. Furthermore, the investigation identifies several dipeptides that can be extracted from V-shaped Lactobacilli for antimicrobial protein therapy against P. aeruginosa and other pathogens.

Effects of dynamic high-pressure microfluidization treatment on the structural, physicochemical, and digestive properties of wheat starch-Lonicera caerulea berry polyphenol complex

Polyphenol complexes can improve the physicochemical and functional properties of starch. In this study, a wheat starch-Lonicera caerulea berry polyphenol complex (WS-LCBP) was prepared using dynamic high-pressure microfluidization (DHPM). The effects of different DHPM pressures (150 and 250 MPa), number of cycles (1 and 3), and LCBP content (0 %, 6 %, 8 %, and 10 %) on the multiscale structure, physicochemical properties, and in vitro digestibility of WS-LCBP were examined. After a single 250 MPa DHPM cycle, Average particle size and water separation rate of WS were reduced by 42.40 % and 16.67 %, the freeze-thaw stability was significantly improved (P < 0.05), and the resistant starch (RS) content 68.67 % was significantly increased (P < 0.05). WS-LCBP has a V-shaped starch structure, which hinders gelatinization and increases enthalpy. The RS content of the WS-LCBP ranged from 72.46 % to 89.09 %, which was significantly higher (P < 0.05) than that of wheat starch subjected to a single 150 MPa DHPM cycle (36.31 %). Three 250 MPa DHPM cycles were beneficial for the formation of WS-LCBP. However, excessive DHPM treatment pressure and frequency reduced the recombination rate of LCBP and wheat starch. This study provides reference data for the industrial production of nutritionally functional wheat-resistant starch using green technologies.

Microporous membrane with ionized sub-nanochannels enabling highly selective monovalent and divalent anion separation

Membranes tailored for selective ion transport represent a promising avenue toward enhancing sustainability across various fields including water treatment, resource recovery, and energy conversion and storage. While nanochannels formed by polymers of intrinsic microporosity (PIM) offer a compelling solution with their uniform and durable nanometer-sized pores, their effectiveness is hindered by limited interactions between ions and nanochannel. Herein, we introduce the randomly twisted V-shaped structure of Tröger’s Base unit and quaternary ammonium groups to construct ionized sub-nanochannel with a window size of 5.89–6.54 Å between anion hydration and Stokes diameter, which enhanced the dehydrated monovalent ion transport. Combining the size sieving and electrostatic interaction effects, sub-nanochannel membranes achieved exceptional ion selectivity of 106 for Cl-/CO32- and 82 for Cl-/SO42-, significantly surpassing the state-of-the-art membranes. This work provides an efficient template for creating functionalized sub-nanometer channels in PIM membranes, and paves the way for the development of precise ion separation applications.

Optimal Design of an Interior Permanent Magnet Synchronous Motor for Electric Vehicle Applications Using a Machine Learning-Based Surrogate Model

This paper presents an innovative design for an interior permanent magnet synchronous motor (IPMSM), targeting enhanced performance for electric vehicle (EV) applications. The proposed motor features a double V-shaped rotor structure with irregular ferrite magnets embedded in the slots between the permanent magnets. This design significantly enhances torque performance. Furthermore, a machine learning-based surrogate model is developed by integrating fine and coarse mesh data. Optimized using the Non-dominated Sorting Genetic Algorithm II (NSGA-II), this surrogate model effectively reduces computational time compared to traditional finite element analysis (FEA).

Observations of the Formation and Disappearance of a Funnel Prominence

We present an observational study of the formation and disappearance of a funnel prominence. Before the funnel prominence formed, cool materials from the top of a preexisting polar crown prominence flowed along saddle-shaped coronal loops to their base, forming a smaller prominence. Meanwhile, the saddle-shaped coronal loops gradually rose, and U-shaped coronal loops, termed prominence horns, began to appear along with a coronal cavity. Afterward, a cool column emerged from the chromosphere, rose vertically into the corona, and then moved laterally to be transported into the U-shaped coronal loops. The formed prominence slid into the chromosphere, while the U-shaped coronal loops and the coronal cavity became more pronounced. As cool materials accumulated at the base of the U-shaped coronal loops, these loops underwent a significant descent and a V-shaped structure appeared at the base of the cool materials, indicating that the U-shaped coronal loops may be dragged down to sag. Subsequently, cool materials from the V-shaped structure continued to flow almost vertically toward the chromosphere, forming the funnel prominence. The vertical downflows might be produced by magnetic reconnection within or between the sagging field lines. Due to persistent vertical downflows, the U-shaped coronal loops were lifted up and prominence materials followed along inclined coronal loops toward the chromosphere, causing the funnel prominence to disappear. Our observations suggest that chromospheric plasma transported into a coronal cavity and then drained out via vertical downflows can form a funnel prominence.

Nonlinear energy harvesting system with multiple stability

The nonlinear energy harvesting systems of the forced vibration with an electron-mechanical coupling are widely used to capture ambient vibration energy and convert mechanical energy into electrical energy. However, the nonlinear response mechanism of the friction induced vibration (FIV) energy harvesting system with multiple stability and stick-slip motion is still unclear. In the current paper, a novel nonlinear energy harvesting model with multiple stability of single-, double- and triple-well potential is proposed based on V-shaped structure spring and the belt conveying system. The dynamic equations for the energy harvesting system with multiple stability and self-excited friction are established by using Euler-Lagrangian equations. Secondly, the static characteristics of the nonlinear restoring force, the friction force, and the potential energy surfaces are obtained to show the nonlinear stiffness, multiple equilibrium points, discontinuous behaviors and multiple well responses. Then, the equilibrium surface of bifurcation sets for the autonomous system is given to show the third-order quasi zero stiffness (QZS3), fifth-order quasi zero stiffness (QZS5), double well (DW) and triple well (TW). The co-dimension bifurcation sets of the self-excited vibration system are analyzed and the corresponding phase portraits for the coexistent of multiple limit cycles are obtained. Furthermore, the analytical formula of amplitude frequency response of the approximated system are obtained by the complex harmonic method. The response amplitudes of charge, current, voltage and power of the forced electron-mechanical coupled vibration system for QZS3, QZS5, DW and TW are analyzed by using the numerically solution. Finally, a prototype of FIV energy harvesting system is manufactured and the experimental system is setup. The experimental works of static restoring forces, damping forcse and the electrical outputs are well agreeable with the numerical results, which testified the proposed FIV energy harvesting model.

Investigation and Experiment of a Novel Chamfered V-Shaped Microstrip Slow-Wave Structure for W-Band Traveling-Wave Tube

Investigation and Experiment of a Novel Chamfered V-Shaped Microstrip Slow-Wave Structure for W-Band Traveling-Wave Tube

Kinematics and Star Formation in the Hub–Filament System G6.55-0.1

Hub–filament systems (HFSs) being the potential sites of formation of star clusters and high-mass stars, provide a testbed for the current theories that attempt to explain star formation globally. It is thus important to study a large number of HFSs using both intensity and velocity information to constrain these objects better observationally. Here, we present a study of the HFS associated with G6.55-0.1 using newly obtained observations of the radio continuum and the J = 2–1 transition of CO, 13CO, and C18O. The radio continuum maps show multiple peaks that coincide with far-infrared dust continuum peaks, indicating the presence of more than one young massive star in the hub of the HFS. We used the velocity information from the C18O(2–1) map to (a) show that the source G6.55-0.1 is not physically associated with the supernova remnant W28 and (b) disentangle and identify the velocity components genuinely associated with G6.55-0.1. Among the velocity-coherent structures identified in the region, we conclude that only the two filaments at 13.8 and 17.3 km s−1 contribute a total mass accretion rate of 3000 M ⊙ Myr−1 to the hub. Both the filaments also show a V-shaped structure, characteristic of gravitational collapse, in their velocity profile at the location of the hub. The estimated mass per unit length of the segments of the filaments is smaller than the critical line masses derived from virial equilibrium considerations. This suggests that the filaments are not gravitationally collapsing as a whole, although their inner parts clearly show evidence of collapse in the form of young star-forming cores. We further conclude that the observed velocity gradients are consistent with the gravitational collapse of the main source in the region as estimated from its mass and size.

High beam quality continuous-wave 320 nm UV laser from a walk-off compensated intracavity frequency-doubled Pr:YLF laser

We report a high beam quality continuous-wave (CW) 320 nm ultra-violet (UV) laser. An end-pumped praseodymium-doped yttrium lithium fluoride (Pr:YLF) laser is constructed in a typical V-shaped cavity structure, while the UV output is obtained through intracavity frequency doubling using LiB3O5 (LBO). We investigate the dependence of the UV output power, as well as the spot profile on the LBO length, and find that the “walk-off” within LBO severely affects both the frequency-doubling efficiency and the beam quality of the UV output. Rotated twin LBO crystals are then applied to substitute for single long LBO crystal to compensate the walk-off effect, resulting in high-power 320 nm output up to 410 mW under the absorbed pump power of 4.0 W at 444 nm, with a high beam quality of M x 2=1.02 and M y 2=1.04.

Steering the energy sharing of electrons in nonsequential double ionization with orthogonally polarized two-color field

Abstract Using the semiclassical ensemble model, the dependence of relative amplitude for the recollision dynamics in nonsequential double ionization (NSDI) of neon atom driven by the orthogonally polarized two-color field (OTC) laser field is theoretically studied. And the dynamics in two typical collision pathways, recollision-impact-ionization (RII) and recollision-excitation with subsequent ionization (RESI), is systematically explored. Our results reveal that the V-shaped structure in the correlated momentum distribution is mainly caused by the RII mechanism when the relative amplitude of the OTC laser field is zero, and the first ionized electrons will quickly skim through the nucleus and share few energy with the second electron. As the relative amplitude increases, the V-shaped structure gradually disappears and electrons are concentrated on the diagonal in the electron correlation spectrum, indicating that the energy sharing after electrons collision is symmetric for OTC laser fields with large relative amplitudes. Our studies show that changing the relative amplitude of the OTC laser field can efficiently control the electron–electron collisions and energy exchange efficiency in the NSDI process.

Design of a high-throughput integrated microfluidic chip combining micromixing and particle sorting functions

Most of the current microfluidic chips can only achieve a single function, such as sample mixing, particle sorting, etc. Based on this, in this paper, we designed an integrated microfluidic chip that combines micromixers and separators, which can realize both sample mixing and particle sorting functions. We use software to simulate the chip’s performance and optimize its structure. The final design of the microfluidic chip consists of two parts: the micro-mixer adopts a V-shaped structure, and there are composite sidewall microstructures and contraction and expansion structures in the flow channel; in the part of the particle sorting, we use a combination of inertial sorting and microfiltration sorting. The chip can ultimately realize rapid short-range sample solution mixing and high-efficiency particle sorting within a specific flow rate, with a mixing effect of more than 94%, a sorting efficiency of up to 100%, and a sorting purity of more than 92%.

Numerical Simulation Study on the Effect of Resistance Microstructure on Blood Flow Resistance

The use of bionic drag-reducing microstructures in artificial blood vessels can effectively reduce their resistance to blood flow. The characteristics of the blood vessel are analysed and simplified, and the resistance reduction effects of three bionic microstructure models, namely V-shaped, rectangular and semi-circular, are compared and analysed by numerical simulations, and the resistance reduction effects of the three groove structures in the tubular model are verified. The results show that the V-shaped groove structure occupies a smaller volume compared to the rectangular and semi-circular structures of the same size, has a significant drag reduction effect, is highly achievable and stable, and is the best choice as a drag reduction microstructure for artificial blood vessels. In addition, the wall shear stresses of the V-groove structure were further analysed to verify the shear effect of this microstructure in artificial blood vessels and to reveal the shear mechanism of the V-groove microstructure.

Effect of Sprouted Buckwheat on Glycemic Index and Quality of Reconstituted Rice.

This study utilized sprouted buckwheat as the main component and aimed to optimize its combination with other grains to produce reconstituted rice with enhanced taste and a reduced glycemic index (GI). The optimal blend comprised wheat flour, sprouted buckwheat flour, black rice flour, and purple potato flour in a ratio of 34.5:28.8:26.7:10.0. Based on this blend, the reconstituted rice processed through extrusion puffing exhibited a purple-black hue; meanwhile, the instant reconstituted rice, produced through further microwave puffing, displayed a reddish-brown color. both imparted a rich cereal flavor. The starch in both types of rice exhibited a V-shaped structure with lower relative crystallinity. Compared to commercial rice, the reconstituted rice and instant reconstituted rice contained higher levels of flavonoids, polyphenols, and other flavor compounds, along with 1.63-fold and 1.75-fold more proteins, respectively. The GI values of the reconstituted rice and the instant reconstituted rice were 68.86 and 69.47, respectively; thus, they are medium-GI foods that can alleviate the increase in blood glucose levels.

Study on the flow characteristics of heterogeneous particles in three types of biomass fast pyrolysis down-tube reactors

A novel staircase down-tube reactor has been developed to solve the problem of the short residence time of ceramic balls in a vertical down-tube reactor and flow separation of biochar powder and ceramic balls in a V-shaped down-tube reactor. Numerical simulation was performed using a coupled approach that combined the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) to simulate the mixing flow of heterogeneous particles (biochar powder and ceramic balls) in three types of down-tube reactors: staircase, vertical, and V-shaped structure. The results show that at an equivalent vertical height. The average residence time for ceramic ball in a staircase down-tube reactor is longer than that of the other two types (tstaircase structure = 1.6 s > tV-shaped structure = 1.0 s > tvertical structure = 0.6 s). The average residence time of biochar powder in three types of down-tube reactors can be classified as follows: tV-shaped structure = tstaircase structure = 1.2 s > tvertical structure = 1.1 s. The flow separation and centripetal motion of heterogeneous particles were observed in V-shaped down-tube reactor. A distinct periodic motion is exhibited in staircase down-tube reactor, it has great significance for exploring the flow and heat transfer regularity of heterogeneous particles. Eccentric distance (E.d) was proposed as a measure of the spatial utilization efficiency of the device. While the degree of coherence (D.c) was used to assess the degree of flow separation among heterogeneous particles.

Design of double V-groove shape-based PCF sensor for cancer detection using RI technique

After COVID-19 healthcare shareholders are more attentive to the different solutions. One of the critical illnesses cancer becomes more changeling after this situation. There are different techniques are suggested as well as developed for detection of the cancer. People of still looking for low-cost solutions for cancer detection. The Photonic crystal fiber is a versatile device utilized for various bio-sensor applications. The double V-groove design proposed in this research offers significant advantages, including enhanced sensitivity, accurate detection capabilities, and easy fabrication. The surface plasmon resonance-based PCF sensor, with its unique V-shaped structure, not only addresses the limitations of conventional prism-based SPR sensors but also opens new possibilities for remote sensing applications. The proposed article is based on the double V-groove photonic crystal fiber (PCF)-based sensor for cancer detection. The Q factor is 155 and the figure of merit (FOM) is 6000RIU−1and sensitivity of the proposed sensor is 60μmRIU−1has obtained. This sensor provides a wide range of detection based on the refractive index (RI) profile of the infected blood.

Experimental Study on the Forced Ventilation Safety during the Construction of a Large-Slope V-Shaped Tunnel

The special large-slope V-shaped structure of underwater tunnels changes the ventilation characteristics during tunnel construction, making the traditional experience limited. Therefore, it is urgent to study the influence of the special structure on the safety of the air environment during construction. In this paper, a series of small-scale experiments were conducted to investigate the ventilation characteristics of V-shaped tunnels. The coupled effects of ventilation parameters (distance of duct outlet from working face Lo, air velocity at the duct outlet uo) and structural characteristics (digging length Ld, slope of the uphill section q) were considered. The extreme slope of the V-shaped tunnel of 8% was considered. The flow field and pollutant transport law were determined by using CO as a tracer in the experiments. The results show that uo has a positive impact on the air return velocity, while Ld has a negative impact, and neither of the other two factors has a significant effect. The transport characteristics of CO in V-shaped tunnels differ from those in flat tunnels, with the former tending to cause unconventional areas of high pollutant concentrations in the horizontal sections. Furthermore, the correlations between CO concentration and distance, ventilation time, and the influence factors discussed in this paper are derived from the experimental results. The conclusions provide guidance for the construction of V-shaped tunnels to prevent air pollution in the construction environment and to improve the working conditions of laborers. Additionally, it can also enrich the ventilation experience in tunnel construction.

Precision-Engineered Medium-Sized Molecular Host and Emitter for Ensuring Consistent Performance in Solution-Processed Narrowband OLEDs.

In this study, two novel multiple resonance (MR) emitters, DtCzBN and Cy-DtCzBN, were designed based on the well-known BCzBN structure and synthesized for narrowband solution-processed organic light-emitting diodes (OLEDs). Cy-DtCzBN possesses a dimeric V-shaped structure formed by coupling two individual DtCzBN units via a nonconjugated cyclohexane linker. When compared with DtCzBN, Cy-DtCzBN, as a medium-sized molecule, was found to maintain the optical and photophysical properties of the corresponding monomeric unit, DtCzBN, but exhibits high thermal stability, excellent solubility, and good film-forming ability. Additionally, solution-processed OLEDs were fabricated by using two sets of molecules: one set of small molecular hosts and emitters (i.e., mCP and DtCzBN) and the other set of medium-sized molecular hosts and emitters (i.e., Cy-mCP and Cy-DtCzBN). Notably, devices using medium-sized molecular hosts and emitters exhibited similar optical and photophysical properties but showed significantly improved reproducibility and thermal stability compared with those based on small molecular hosts and emitters. Our current study provides some insights into molecular design strategies for thermally stable hosts and emitters, which are highly suitable for solution-processed OLEDs.

Dual-path coupling V-shaped structure off-axis integrated cavity output spectroscopy (V-OA-ICOS) for water vapor stable isotope detection at 3.66 μm

Residual cavity mode noise and weak output signal are the main factors that restrict the detection performance of off-axis integrated cavity output spectroscopy (OA-ICOS). In order to overcome the above drawbacks, a novel V-shaped off-axis integrated cavity output spectroscopy (V-OA-ICOS) device was demonstrated, and the dual-path coupling method was further proposed. The dual-path coupling V-OA-ICOS device can not only suppress the residual cavity mode noise but also enhance the intensity of the output signal. The V-shaped resonator cavity ensures a more uniform and square-shaped spot pattern distribution on the surface of the highly reflective mirrors, significantly reducing spots overlap. The dual-path coupling method can re-couple the laser reflected by the front cavity mirror, thereby increasing the total energy and mode density of the cavity. The spectrum of water vapor stable isotopes HD16O and H216O at 3.66 μm was measured to illustrate the performance of the presented approach, the dual-path coupling V-OA-ICOS increases the signal-to-noise ratio (SNR) by a factor ∼ 2.1 compared to single path V-OA-ICOS and the signal intensity by a factor of ∼ 2. The δD variation was obtained by measuring the outdoor water vapor isotope using this device for three consecutive days. The variation range of δD is −220‰ ∼ −120‰. This work proposes a new cavity structure and optical re-coupling method, which offers a novel approach to enhance the performance of OA-ICOS devices.

The effect of ligand/ metal-ligand ratio on the structural architectures of five different 1D zinc(II) coordination polymers with pyridyl derivative ligands

Five coordination compounds, [Zn(bppc)Cl]n·0.5nH2O (1) [Zn2(bppc)2(suc)]n (2), [Zn(dppb)Cl]n·nH2O (3) [Zn(dppb)Cl]n (4) [Zn2(dppb)2(bdc)]n·2nH2O(5) (Hbppc =2,6-bis(pyrazin-2-yl)pyridine-4-carboxylic acid, H2suc=succinic acid, Hdppb=4-(2,6-di(pyrazin-2-yl)pyridine-4-yl)-benzoic acid, H2bdc=1,4-benzenedicarboxylic acid), with the same one dimensions but different patterns have been hydrothermally synthesized and structurally characterized. Single crystal X-ray analysis revealed that compound 1 shows one-dimensional wave chain structure, compound 2 to 5 show one-dimensional ladder chain structure, one-dimensional V-shaped chain structure, one-dimensional linear chain structure and one-dimensional A-shaped chain structure, respectively. The structure differences of 1–5 show that ligand including auxiliary ligand and metal-ligand ratio have important influence on the final structures. Additionally, the luminescent properties of 1–5 have been investigated with fluorescent spectra in the solid state and fluorescence sensing experiments show that compound 1 exhibit a great selectivity and sensitivity for detection of Cu2+ion and nitrobenzene.

Atomic-scale characterization of V-shaped interface structure of η1 precipitates in Al–Zn–Mg alloy

Al–Zn–Mg alloys have attracted significant interest in the automotive industry owing to their high strength and light weight. Precipitation hardening is the primary mechanism by which these alloys are strengthened, meaning the analysis of the shape, size, and fraction of the precipitates is crucial. In this study, the interfacial structure of precipitates, which influences the mechanical properties of alloys, was investigated. Aberration-corrected scanning transmission electron microscopy studies revealed the atomic structure of the unique V-shaped interface structure of the η1 precipitates, which are the most prevalent among the η precipitates produced in this alloy. The structure was investigated from an energetic perspective using first-principles calculations, which revealed that the formation of the V-shaped interface structure increased the stability through strain relaxation in both the aluminum matrix and η1. The results provide valuable insights into the formation and growth mechanisms of precipitates, paving the way for further advancements in this field.