Baryogenesis from ultra-slow-roll inflation

The ultra-slow-roll (USR) inflation represents a class of single-field models with sharp deceleration of the rolling dynamics on small scales, leading to a significantly enhanced power spectrum of the curvature perturbations and primordial black hole (PBH) formation. Such a sharp transition of the inflationary background can trigger the coherent motion of scalar condensates with effective potentials governed by the rolling rate of the inflaton field. We show that a scalar condensate carrying (a combination of) baryon or lepton number can achieve successful baryogenesis through the Affleck-Dine mechanism from unconventional initial conditions excited by the USR transition. Viable parameter space for creating the correct baryon asymmetry of the Universe naturally incorporates the specific limit for PBHs to contribute significantly to dark matter, shedding light on the cosmic coincidence problem between the baryon and dark matter densities today.

Evaluation of optimum condition to improve the microstructure in hot-rolled medium carbon steel by elimination of coarse pearlite patches

The present study is aimed to eliminate the undesirable microstructure in the real working condition of the steel unit. In this work, the microstructure of hot-rolled medium carbon steel (grade 45C8) is studied for application in the automotive industry. The effect of the temperature and rolling rate on the microstructure has been thoroughly investigated by analyzing the microstructure containing ferrite and pearlite phases after each trial run of hot-rolled steel. The desired microstructure of fine ferrite and pearlite is very much essential in hot-rolled medium carbon steel for better strength and uniform properties of the material. The formation of coarse pearlite is undesirable, which may lead to breakage during drawing and hardness variation in the hot-rolled steel. Therefore, this study is focused to find the optimum condition for achieving the microstructure containing uniform distribution of fine pearlite and ferrite without the presence of blocky pearlite patches.

Aileron size and location to minimise induced drag during rolling-moment production at zero rolling rate

Most modern aircraft employ discrete ailerons for roll control. The induced drag, rolling moment, and yawing moment for an aircraft depend in part on the location and size of the ailerons. In the present study, lifting-line theory is used to formulate theoretical relationships between aileron design and the resulting forces and moments. The theory predicts that the optimum aileron geometry is independent of prescribed lift and rolling moment. A numerical potential flow algorithm is used to evaluate the optimum size and location of ailerons for a wide range of planforms with varying aspect ratio and taper ratio. Results show that the optimum aileron design to minimise induced drag always extends to the wing tip. Impacts to induced drag and yawing moment are also considered, and results can be used to inform initial design and placement of ailerons on future aircraft. Results of this optimisation study are also compared to theoretical optimum results that could be obtained from morphing-wing technology. Results of this comparison can be used to evaluate the potential benefits of using morphing-wing technology rather than traditional discrete ailerons.

Design and Test of Double-Cutterbar Structure on Wide Header for Main Crop Rice Harvesting

Harvesting main crop rice with a wide header at a required height can increase its ratoon crop yield by decreasing the stubble rolling rate. However, an increased harvest width brings in more input material in a specific time, causing the size enlargement or working speed slowdown of harvesters. To solve this issue, a double-cutterbar structure was proposed. To provide a design baseline for the structure, the cutterbar configuration methods based on rice plant deformation were developed and verified, stalk shearing tests were conducted, and a double-cutterbar prototype was fabricated and tested. The results indicated that the methods developed for the configuration of the upper and lower cutterbars could considerably implement their functions of lowering the straw-grain ratio and keeping stubble height as required. The shearing tests indicated that the bevel angle significantly influenced the total shearing energy on each cutting point in Internode 2 and 3 (p < 0.05) due to the increased stalk cross sectional area. The stubble rolling rate, panicle straw length and stubble height of the developed harvester were 26.9 %, 125 ± 80 mm and 332 ± 22 mm, respectively, which could meet the requirements of main crop rice harvesting. The outcomes indicated the functionality and practicability of the double-cutterbar structure developed based on rice plant deformation and shearing properties.

Structure-function analysis of the maize bulliform cell cuticle and its role in dehydration and leaf rolling

The cuticle is a hydrophobic layer on the outer surface plant shoots, which serves as an important interaction interface with the environment. It consists of the lipid polymer cutin, embedded with and covered by waxes, and provides protection against stresses including desiccation, UV radiation, and pathogen attack. Bulliform cells form in longitudinal strips on the adaxial leaf surface, and have been implicated in the leaf rolling response observed in drought stressed grass leaves. In this study, we show that bulliform cells of the adult maize leaf epidermis have a specialized cuticle, and we investigate its function along with that of bulliform cells themselves. Analysis of natural variation was used to relate bulliform strip pattering to leaf rolling rate, providing evidence of a role for bulliform cells in leaf rolling. Bulliform cells displayed increased shrinkage compared to other epidermal cell types during dehydration of the leaf, providing a potential mechanism to facilitate leaf rolling. Comparisons of cuticular conductance between adaxial and abaxial leaf surfaces, and between bulliform-enriched mutants vs. wild type siblings, provided evidence that bulliform cells lose water across the cuticle more rapidly than other epidermal cell types. Bulliform cell cuticles have a distinct ultrastructure, and differences in cutin monomer content and composition, compared to other leaf epidermal cells. We hypothesize that this cell type-specific cuticle is more water permeable than the epidermal pavement cell cuticle, facilitating the function of bulliform cells in stress-induced leaf rolling observed in grasses.One sentence summaryBulliform cells in maize have a specialized cuticle, lose more water than other epidermal cell types as the leaf dehydrates, and facilitate leaf rolling upon dehydration.

Application of Queuing Theory in Production Efficiency of Direct Rolling Process of Long Product

Based on the mathematical method of queuing theory, the queuing model of billets in the direct rolling process of the long product was established, which represented the conveying process of billets at the casting and rolling interface. Using the billets queuing model, the influence of different steel quantity, length, speed and other factors on the average waiting time of a single billet in the direct rolling production process was analyzed. Combined with the temperature drop of billets, the optimal average waiting time for a single billet was determined. The method improved the conveying connection efficiency of the casting-rolling interface and the direct rolling rate of billets.

Analytic and computational analysis of wing twist to minimize induced drag during roll

Geometric and/or aerodynamic wing twist can be used to produce a lift distribution that results in a rolling moment. A decomposed Fourier-series solution to Prandtl’s lifting-line theory is used to develop analytic spanwise antisymmetric twist distributions for roll control that minimize induced drag on wings of arbitrary planform in pure rolling motion. Roll initiation, steady rolling rate, and the transition between the two are each considered. It is shown that if these antisymmetric twist distributions are used, the induced drag is proportional to the square of the rolling moment, and the induced drag during a steady rolling rate is equal to that on the wing at the same lift coefficient with no rolling rate or antisymmetric twist distribution. Results also show that if these antisymmetric twist distributions are used on straight, tapered wings without symmetric twist, any rolling maneuver for which the rolling rate and rolling moment have the same sign will always produce a yawing moment in the opposite direction. Computational results are also included, which were obtained using a gradient-based optimization algorithm in combination with a modern numerical lifting-line algorithm to find the optimum twist solutions. The resulting twist, induced drag, and yawing moment solutions compare favorably with the analytic solutions developed in the text. The solutions presented here can be used to inform the design of morphing aircraft.

Development and Characterization of Bilayer Wound Healing Patch Nanofiber Fabricated by Electrospinning

The present study aims to develop bilayer polymeric nanofiber patch (PNP) fabricated by electrospinning technique using for wound dressing. The nanofiber was prepared by various concentrations of polyvinyl alcohol (PVA) and modified tamarind seed gum loaded with clindamycin HCl (CM) in first layer and Eudragit® S100 for a second layer. ​According to the SEM result, the physical appearance, the sprayed products prepared from PVA, mixture of PVA and gum, Eudragit® S100 were in round fiber with different diameter size ranged from 153-1830 nm. The polymer concentration, solution conductivity and surface tension affected on the appearance of the nanofiber. The patch was successfully prepared in form of two layer welded with the nanofiber under the optimized electrospinning condition which are 20 kV of applied voltage, 20 cm of injection distance, 0.25 mL of solution feed rate and 48 rpm of collector rolling rate. The DSC and PXRD indicated that the drug in PNPs was in amorphous form. Biological test revealed that bilayer PNPs contained PVA 10%, modified tamarind seed gum 5% and clindamycin 1% had an efficiency to inhibit Staphylococcus aureus. These results show the possibility of improving nanofiber patch strength by using Eudragit® S100 and modified tamarind gum seed as a natural material in nanofiber patch formulation.