Air flow conditions in workspace of mulcher

ArticleCurrently, there has been a great effort on increasing the efficiency of agricultural machinery. The energy demands of mulching with the vertical axis of rotation depends on the amount of pr ocessed material per unit of time, its properties and efficiency of material processing. Another important factor that is affecting the overall energy demands is the energy losses, which can be even higher than energy, required for the processing of materi al. The efficiency of the material processing and the energy losses are influenced to a large extent by the air flow inside the mulcher workspace, which is created by the movement of working tools. The air flow ensures the repeated contact of the processed material with the working tools, affects the energy losses and the quality of work. The contribution deals with the air flow conditions inside the workspace of mulcher with the vertical axis of rotation. The velocity of the air flow was measured my means of LDA (Laser Doppler Anemometry) method in three planes above the surface (180, 100 and 20 mm ) and in two directions (peripheral and radial). The laboratory model of one mulcher rotor from mulcher MZ 6000 made by BEDNAR Ltd. company was used for the measu rement. From the results it is evident that the maximum values of peripheral velocity of the air flow reach approx. 50% of the velocity of the tools. In the radial plane an air vortex is created between 20 and 100 mm planes above the surface around the tip of the blade

Analysis of the Sam50 translocase of excavate organisms supports evolution of divergent organelles from a common endosymbiotic event

As free-living organisms the ancestors of mitochondria and plastids encoded complete genomes, proteomes and metabolomes. As these symbionts became organelles all these aspects were reduced – genomes have degenerated with the host nucleus now encoding the most of the remaining endosymbiont proteome, while the metabolic processes of the symbiont have been streamlined to the functions of the emerging organelle. By contrast, the topology of the endosymbiont membrane has been preserved, necessitating the development of complex pathways for membrane insertion and translocation. In this study, we examine the characteristics of the endosymbiont-derived β-barrel insertase Sam501 in the excavate super-group. A candidate is further characterized in Trichomonas vaginalis, an unusual eukaryote possessing degenerate hydrogen-producing mitochondria called hydrogenosomes. This information supports a mitochondriate eukaryotic common ancestor with a similarly evolved β-barrel insertase, which has continued to be conserved in degenerate mitochondria

The Minimal Proteome in the Reduced Mitochondrion of the Parasitic Protist Giardia intestinalis

The mitosomes of Giardia intestinalis are thought to be mitochondria highly-reduced in response to the oxygen-poor niche. We performed a quantitative proteomic assessment of Giardia mitosomes to increase understanding of the function and evolutionary origin of these enigmatic organelles. Mitosome-enriched fractions were obtained from cell homogenate using Optiprep gradient centrifugation. To distinguish mitosomal proteins from contamination, we used a quantitative shot-gun strategy based on isobaric tagging of peptides with iTRAQ and tandem mass spectrometry. Altogether, 638 proteins were identified in mitosome-enriched fractions. Of these, 139 proteins had iTRAQ ratio similar to that of the six known mitosomal markers. Proteins were selected for expression in Giardia to verify their cellular localizations and the mitosomal localization of 20 proteins was confirmed. These proteins include nine components of the FeS cluster assembly machinery, a novel diflavo-protein with NADPH reductase activity, a novel VAMP-associated protein, and a key component of the outer membrane protein translocase. None of the novel mitosomal proteins was predicted by previous genome analyses. The small proteome of the Giardia mitosome reflects the reduction in mitochondrial metabolism, which is limited to the FeS cluster assembly pathway, and a simplicity in the protein import pathway required for organelle biogenesis

Live Imaging of Mitosomes and Hydrogenosomes by HaloTag Technology

Hydrogenosomes and mitosomes represent remarkable mitochondrial adaptations in the anaerobic parasitic protists such as Trichomonas vaginalis and Giardia intestinalis, respectively. In order to provide a tool to study these organelles in the live cells, the HaloTag was fused to G. intestinalis IscU and T. vaginalis frataxin and expressed in the mitosomes and hydrogenosomes, respectively. The incubation of the parasites with the fluorescent Halo-ligand resulted in highly specific organellar labeling, allowing live imaging of the organelles. With the array of available ligands the HaloTag technology offers a new tool to study the dynamics of mitochondria-related compartments as well as other cellular components in these intriguing unicellular eukaryotes

The Physiology and Proteomics of Drought Tolerance in Maize: Early Stomatal Closure as a Cause of Lower Tolerance to Short-Term Dehydration?

Understanding the response of a crop to drought is the first step in the breeding of tolerant genotypes. In our study, two maize (Zea mays L.) genotypes with contrasting sensitivity to dehydration were subjected to moderate drought conditions. The subsequent analysis of their physiological parameters revealed a decreased stomatal conductance accompanied by a slighter decrease in the relative water content in the sensitive genotype. In contrast, the tolerant genotype maintained open stomata and active photosynthesis, even under dehydration conditions. Drought-induced changes in the leaf proteome were analyzed by two independent approaches, 2D gel electrophoresis and iTRAQ analysis, which provided compatible but only partially overlapping results. Drought caused the up-regulation of protective and stress-related proteins (mainly chaperones and dehydrins) in both genotypes. The differences in the levels of various detoxification proteins corresponded well with the observed changes in the activities of antioxidant enzymes. The number and levels of up-regulated protective proteins were generally lower in the sensitive genotype, implying a reduced level of proteosynthesis, which was also indicated by specific changes in the components of the translation machinery. Based on these results, we propose that the hypersensitive early stomatal closure in the sensitive genotype leads to the inhibition of photosynthesis and, subsequently, to a less efficient synthesis of the protective/detoxification proteins that are associated with drought tolerance

Partial molar volumes of organic solutes in water. II. Dihydroxybenzenes at temperaturesT=(298 to 473) K and pressures up to 30 MPa

Density data for dilute aqueous solutions of three dihydroxybenzenes in the temperature range (298.15 to 473.15) K and at either atmospheric pressure, or at pressures close to the saturated vapour pressure of water, and at elevated pressures up top=30 MPa are presented along with partial molar volumes calculated from the experimental data. The data were obtained using both a high-temperature high-pressure flow vibrating-tube densimeter, and a commercial vibrating-tube cell DMA 602HT

Partial molar volumes of organic solutes in water. IV. Benzoic and hydroxybenzoic acids at temperatures fromT = 298 K toT = 498 K and pressures up to 30 MPa

Density data for dilute aqueous solutions of benzoic acid and three hydroxybenzoic acids obtained in the temperature range 298.15 K to 498.15 K and at either atmospheric pressure or at pressures close to the saturated vapour pressure of water and at elevated pressures up to 30 MPa are presented along with partial molar volumes calculated from the experimental data. The data were obtained by using both a high-temperature high-pressure flow vibrating-tube densimeter and a commercial vibrating-tube cell DMA 602HT

Dysprosium doped amorphous chalcogenide films prepared by pulsed laser deposition

International audienceThin amorphous Ga-Ge-Sb-S films (pure and dysprosium doped) were prepared by pulsed laser deposition (PLD). Compositional, morphological and structural characteristics of the films were studied by SEM-EDS, atomic force, scanning electron microscopy, and Raman scattering spectroscopy analyses. The emission band centered at 1.3 μm corresponding to 6F11/2,6H9/2−6H15/2 radiative electron transitions of Dy3+ ions was identified in photoluminescence spectra of dysprosium doped thin films. A study of the optical properties (transmittance, index of refraction, optical band gap) and the effects of exposure and thermal annealing below the glass transition temperature on the optical parameters of thin films from the Ga-Ge-Sb-S system is presented

Simulation of size-dependent aerosol deposition in a realistic model of the upper human airways

An Eulerian internally mixed aerosol model is used for predictions of deposition inside a realistic cast of the human upper airways. The model, formulated in the multi-species and compressible framework, is solved using the sectional discretization of the droplet size distribution function to accurately capture size-dependent aerosol dynamics such as droplet drift, gravitational settling and diffusion. These three mechanisms are implemented in a consistent way in the model, guaranteeing that the total droplet mass as given by the droplet size distribution is always equal to the total droplet mass due to the mass concentration fields. To validate the model, we simulate monodisperse glycerol aerosol deposition inside the lung cast, for which experimental data is available. Provided that an adequate computational mesh is used and an adequate boundary treatment for the inertial deposition velocity, excellent agreement is found with the experimental data. Finally, we study the size-dependent deposition inside the lung cast for a polydisperse aerosol with droplet sizes ranging from the nanometer scale to beyond the micrometer scale. The typical ‘V-shape’ deposition curve is recovered. The aim of this paper is to 1) provide an overview of the Eulerian aerosol dynamics model and method, to 2) validate this method in a relevant complex lung geometry and to 3) explore the capabilities of the method by simulating polydisperse aerosol deposition