Distinct Particle Films Impacts on Olive Leaf Optical Properties and Plant Physiology

The olive fruit fly is worldwide considered a major harmful pest of the olive agroecosystem. In Italy, the fruit fly infestation is traditionally countered by spraying chemical insecticides (e.g., dimethoate), but due to the recent ban of dimethoate by the Reg EU2019/1090 and the increasing awareness of consumers of food sustainability, the interest in developing chemical-free alternatives to pesticides, such as the use of particle-films, is rising. A field experiment was conducted to assess the effect of different particle films (kaolin-base and zeolitite-base) on leaf gas exchanges and leaf optical properties. Results showed that with the dust accumulation on the leaves’ surface, photosynthesis, stomatal conductance, transpiration and water use efficiency were significantly lower in kaolin-treated olive trees compared to those treated with zeolitite and to the control, while olive trees treated with zeolitite showed physiological parameters similar to the untreated plants. Microstructural differences of different particle film on the leaf and olive surfaces emerged by ESEM observations also influenced leaf optical properties. Oils produced by zeolitite-treated plants show higher intensities of gustatory and olfactory secondary flavors compared to kaolin and test oils.

Distinct particle modes in the lower stratosphere constrain secondary aerosol chemistry and gas-phase concentrations

<p>There are distinct types of aerosol particles in the lower stratosphere. Stratospheric sulfuric acid particles with and without meteoric metals coexist with mixed organic-sulfate particles that originated in the troposphere. That these particles remain distinct has important implications for aerosol chemistry and the concentrations of several gas-phase species. Neither semi-volatile organics nor ammonia can be in equilibrium with the gas phase. The gas-phase concentrations of semi-volatile organics and ammonia must be very low, or else the sulfuric acid particles would not stay so pure. The upper concentration limits are around a pptv. Yet the sulfuric acid particles in the Northern Hemisphere show a very small but measurable uptake of organics and ammonia, indicating non-zero gas-phase concentrations of those species. Finally, the organic-sulfate particles must be resistant to photochemical loss, or else they would no longer retain their organic content.</p>

The effect of rotation speed and mixer size on granular flow and mixing in bladed mixers

Bladed mixers are widely used in the industry for granular mixing. In the past decades, the mixing of particles in bladed mixers has been extensively investigated experimentally and numerically. Recently, GPU-based DEM has been employed to simulate various industrial-scale applications. This work aims to apply the GPU-based DEM to investigate the effect of rotation speed and mixer size on granular mixing in bladed mixers of different sizes. The simulation in a larger mixer revealed distinct particle flow patterns that well-describe the mixing mechanism which is difficult to observe in a smaller mixer. The Lacey’s mixing index curves revealed a delay in mixing as the mixer size increases. The mixing rate decreases as the mixer size increases and it can be improved with increasing rotation speed. The average particle velocity increase significantly with increasing rotation speed and mixer size.

Distinct particle properties between ultrafine and accumulation modes under clean and polluted urban environments

<p>In this study, we report a phenomenon of fast changing in aerosol hygroscopicity between clean and pollution periods observed frequently in urban Beijing during winter using a hygroscopicity tandem mobility analyzer (H-TDMA). The cause of this phenomenon and the formation process of particles in different modes are discussed. During clean periods, ultrafine mode particles (Nucleation and Aitken modes) mainly stem from nucleation events with subsequent growth. During heavy pollution periods, they originate chiefly from primary emissions. Coarser-mode particles like accumulation mode particles are mainly from primary emission during clean periods and aqueous reactions during pollution periods. This finding based on H-TDMA measurement can make up the deficiency of mass-dependent instruments in analyzing sources and chemical processes of ultrafine mode particles.</p>

Growth and formation mechanism of shape-selective preparation of ZnO structures: correlation of structural, vibrational and optical properties

A shape-selective preparation method was used to obtain highly crystalline rod-, needle-, nut-, and doughnut-like ZnO morphologies with distinct particle sizes and surface areas.

Microfluidic particle zipper enables controlled loading of droplets with distinct particle types

We describe a microfluidic particle zipper which enables hydrogel bead pairing at high throughput for single-cell genomic applications.

Edge Detection Using Distinct Particle Swarm Optimization

Edge detection is long-established in computer perception approach such as object detection, shape matching, medical image classification etc. For this reason many edge detectors like, Sobel, Robert, Prewitt, Canny etc. has been progressed to increase the effectiveness of the edge pixels. All these approaches work fine on images having minimum variation in intensity. Therefore, a new objective function based distinct particle swarm optimization (DPSO) is proposed in this paper to identify unbroken edges in an image. The conventional edge detectors such as “Canny” & computational intelligent techniques like ACO, GA and PSO are compared with proposed algorithm. Precision, Recall & F-Score is used as performance parameters for these edge detection techniques. The ground truth images are taken as reference edge images and all the edge images acquired by different edge detection systems are contrasted with reference edge image with ascertain the Precision, Recall and F-Score. The techniques are tested on 500 test images from the “BSD500” datasets. The empirical results presented by the proposed algorithm performance better than other edge detection techniques in the images. The proposed method observes edges more accurately and smoothly than other edge detection techniques such as “Canny, ACO, GA and PSO” in different images

The Role of Particle Shape on the Sintering of Clay Based Ceramics

The influence of the clay particle morphology on the structural consolidation process associated with high temperature sintering was studied. By computer modeling, the different degrees of packing related to the distinct shapes naturally assumed by the particle clays as well as the consolidation conditions, based on solid sate reactions and surface diffusion were simulated. The model was compared with experimental data of clays fired at several temperatures. This permitted to explain differences in the behavior of red ceramics that was sintered with clays presenting distinct particle shapes.