Relations in the Size Variation of Plant Organs: a Case Study of Staghorn Sumac Leaves and Longleaf Pine Cone Scales

Plants automatically control the size variations in organs to achieve efficient exploitation of resources. However, it is unclear whether the scaling relationships of plant organs share a similar character for different individuals under varied micro-conditions (e.g., light and soil water). We conducted a case study of the lengths of staghorn sumac leaves and longleaf pine cone scales to test the relationships. Our results indicated that although there were size variations, there existed power laws of frequency in the lengths of staghorn sumac leaves and longleaf pine cone scales. The exponents differed but were positively correlated with the minimum length of leaves or cone scales. Taylor’s Law existed in the lengths of cone scales and some tree leaves, and scale break was observed. This study provides new information on scaling relationships and self-organization in the patterns of tree parts arrangement. Taylor’s Law may be used to detect minor changes in the growth regime.

Modal Decomposition Analysis of Combustion Instability Due to External Perturbation in a Mesoscale Burner Array

In this work, the growth regime of combustion instability was studied by analyzing 10 kHz OH planar laser induced fluorescence (PLIF) images through a combination of dynamic mode decomposition (DMD) and spectral proper orthogonal decomposition (SPOD) methods. Combustion instabilities were induced in a mesoscale burner array through an external speaker at an imposed perturbation frequency of 210 Hz. During the transient onset of combustion instabilities, 10 kHz OH PLIF imaging was employed to capture spatially and temporally resolved flame images. Increased acoustic perturbations prevented flame reignition in the central recirculation zone and eventually led to the flame being extinguished inwards from the outer burner array elements. Coherent modes and their growth rates were obtained from DMD spectral analyses of high-speed OH PLIF images. Positive growth rates were observed at the forcing frequency during the growth regime. Coherent structures, closely associated with thermoacoustic instability, were extracted using an appropriate SPOD filter operation to identify mode structures that correlate to physical phenomena such as shear layer instability and flame response to longitudinal acoustic forcing. Overall, a combination of DMD and SPOD was shown to be effective at analyzing the onset and propagation of combustion instabilities, particularly under transient burner operations.

Why does Germany abstain from statutory bargaining extensions? Explaining the exceptional German erosion of collective wage bargaining

Against the European trend, German statutory collective bargaining extensions (SBEs) have decreased in the last two decades, contributing to the exceptional erosion of German wage-bargaining coverage. This article distinguishes between two liberalization dynamics: an intrasectoral dynamic that started with the introduction of employers’ association memberships outside the scope of collective agreements, and an intersectoral dynamic. The latter is the result of an abnormal German institutional feature, the veto power of the employers’ umbrella association in the committees that have to approve SBE applications. Activation of this veto enabled employers to promote collective bargaining erosion in sectors other than their own, in order to contain cost pressures. This intersectoral liberalization dynamic has been part of Germany’s transition into an asymmetrically export-driven growth regime and could be stopped by means of political reforms.

Effects of Gas Composition in Producing Carbon Nanomaterials by Plasma Enhanced Chemical Vapor Deposition

Carbon nanomaterials are becoming new materials which can be used in many fields including transistors, sensors, displays, hydrogen storage, capacitors, catalyst supporters and so on. PECVD is an important method for producing carbon nanomaterials. However, it remains a challenge to control the final production of the PECVD process. This paper tries to figure out the gas factors influencing the growth of different carbon nanomaterials. This paper begins with a brief introduction of PECVD and the growth regime of carbon nanowalls and carbon nanotubes. It discusses how the Argon, carbon source, hydrogen and other gas affect the growth of CNMs. The paper ends with a discussion on the practical influence of confirming the function of each gas.

Study of the initial stage of GaAs growth on FIB-modified silicon substrates

In this work, we studied the effect of the deposition thickness, growth rate, arsenic flux, and implantation dose on the morphology of the GaAs nanostructures grown on modified Si areas. It is shown that an increase in the growth rate at the initial stages of the growth process leads to the transition of the growth regime from layered-like to one-dimensional with the formation of nanowires. Studies of the effect of As4 pressure have shown that a change in the equivalent As4 flux in the range of 3.7 - 5.0 ML/s does not lead to any significant change in the structure of the GaAs layer in the modified areas. An increase in the implantation dose during processing with a focused ion beam led to disordering of the directions of the grown nanowires due to the degradation of the substrate crystal structure.

Crystallisation and polymorph selection in active Brownian particles

We explore crystallisation and polymorph selection in active Brownian particles with numerical simulation. In agreement with previous work (Wysocki et al. in Europhys Lett 105:48004, 2014), we find that crystallisation is suppressed by activity and occurs at higher densities with increasing Péclet number ($${ Pe }$$ Pe ). While the nucleation rate decreases with increasing activity, the crystal growth rate increases due to the accelerated dynamics in the melt. As a result of this competition, we observe the transition from a nucleation and growth regime at high $${ Pe }$$ Pe to “spinodal nucleation” at low $${ Pe }$$ Pe . Unlike the case of passive hard spheres, where preference for FCC over HCP polymorphs is weak, activity causes the annealing of HCP stacking faults, thus strongly favouring the FCC symmetry at high $${ Pe }$$ Pe . When freezing occurs more slowly, in the nucleation and growth regime, this tendency is much reduced and we see a trend towards the passive case of little preference for either polymorph.

Wage- and profit-led growth regimes: a panel-data approach

The extensive empirical effort made in the growth and distribution literature to estimate whether economic growth is wage- or profit-led has not sufficiently considered the theoretical foundation of the Neo-Kaleckian model. This paper attempts to respect key tenets of the investment function by estimating a panel-data model in which country-specific structural characteristics and possible endogenous relationships in income distribution and economic growth are explicitly considered. The identification strategy is based on several estimates of the capital stock and the rate of capacity utilization for 61 countries over the period between 1995 and 2014. The main results suggest that the growth regime was wage-led in developed countries, while most developing countries exhibited a profit-led growth regime. Interestingly, however, while the profit-led regime occurs through the international trade channel in Latin American countries, in other developing countries, the causality channel is mainly related to the domestic investment function.

Agricultural Support Policies and China’s Cyclical Evolutionary Path of Agricultural Economic Growth

Due to the weak nature of agricultural production, governments usually adopt supportive policies to protect food security. To discern the growth of agriculture from 2001 to 2018 under China’s agricultural support policies, we use the nonlinear MS(M)-AR(p) model to distinguish China’s agricultural economic cycle into three growth regimes—rapid, medium, and low—and analyze the probability of shifts and maintenance among the different regimes. We further calculated the average duration of each regime. Moreover, we calculated the growth regime transfers for specific times. In this study, we find that China’s agricultural economy has maintained a relatively consistent growth trend with the support of China’s proactive agricultural policies. However, China’s agricultural economy tends to maintain a low-growth status in the long-term. Finally, we make policy recommendations for agricultural development based on our findings that continue existing agricultural policies and strengthen support for agriculture, forestry, and animal husbandry.