Investigation of grain separation through straw layer over …

Straw walker is a separator that separates grain from straw, and limits the efficiency of combine-harvesters therefore special attention is devoted to the development and improvement of its design and technological parameters. The most important parameter of walker operation is Froude-number k that depends on the amplitude of the straw walker movement in vertical direction, i.e., walker sieve oscillation amplitude r and angular velocity ω. High speed camera used in the investigation tests helped to determine not only the behavior of the straw layers on the oscillating sieve of straw walker but also the duration of grain penetration (separation) through the straw. With estimation of these parameters the rational values of Froude-number k were substantiated. It has been determined that at various ω and r combinations when k=const. sieve vertical accelerations when the crankshaft is rotated at the same angle are equal, but speeds and displacements are varied. For this reason the duration of grain separation is different. The rational angular velocity of the crankshaft is 22.5 s-1 (r=0.05 m), as then the straw layer when the crankshaft is rotated at the angle 2π, raised from the walker surface (sieve) the most early and strokes with it latest, i.e. the duration of free movement of the straw is 1.5 times longer and the grain separation about 15% more intensive than when ω=21.5 s-1. The estimation of grain separation enabled to define critical value of crankshaft angular velocity equal to ω=23.5 s-1. When this value is exceeded the top straw layers receive only one stroke when the crankshaft is rotated at the angle 4π, therefore the increase of crankshaft angular velocity and, simultaneously, sieve oscillation intensity above the critical value is inexpedient

Investigagation of vibrations of variable cross-section linking elements

The applicability of analytical models for vibrations of variable cross-section two- layered cylindrical structural elements is investigated. Natural frequencies of longitudinal and lateral vibrations are calculated and validated experimentally. Natural frequency )( 0 n ? dependence on material properties (?, E) and geometric parameters (l, R, r, S) of structural element provide means for optimization of vibration amplitude characteristic

Full characterization of vibrational coherence in a porphyrin chromophore by two-dimensional electronic spectroscopy

In this work we present experimental and calculated two-dimensional electronic spectra for a 5,15-bisalkynyl porphyrin chromophore. The lowest energy electronic Qy transition couples mainly to a single 380 cm–1 vibrational mode. The two-dimensional electronic spectra reveal diagonal and cross peaks which oscillate as a function of population time. We analyze both the amplitude and phase distribution of this main vibronic transition as a function of excitation and detection frequencies. Even though Feynman diagrams provide a good indication of where the amplitude of the oscillating components are located in the excitation-detection plane, other factors also affect this distribution. Specifically, the oscillation corresponding to each Feynman diagram is expected to have a phase that is a function of excitation and detection frequencies. Therefore, the overall phase of the experimentally observed oscillation will reflect this phase dependence. Another consequence is that the overall oscillation amplitude can show interference patterns resulting from overlapping contributions from neighboring Feynman diagrams. These observations are consistently reproduced through simulations based on third order perturbation theory coupled to a spectral density described by a Brownian oscillator model

Vibration and noise measurements during silage thickening with inertia directional vibrator

Literature review and performed theoretical investigation indicates that it is environmentally and economically feasible for small and average size farms to use vibrational thickening method for silage preparation. However, the results need to be verified with experiments. This research work provides analysis and evaluation of flat surface inertia type vibrator, in which the excitation force is induced by turning the unbalanced mass. Directed action vibrator was manufactured and tested. Results indicate that application of inertia directional vibrator for thickening of finely chopped corn and Jerusalem artichoke stalk mixture, after 40 minutes thickening, allows to obtain a 114.6 kg m-3 density for both layers, while thickening the first 65 kg mass mixture layer after 10 minutes - a 197.9 kg m-3 density. Dry material densities correspond to 61.5 and 106.3 kg m-3 respectively. After examination of fodder quality it was determined that corn mixture silage, thickened by the inertia directional vibrator, satisfies highgrade silage requirements. Performed tests demonstrated that the effect of vibrations on whole body and the measured noise levels do not have detrimental effect on human health and the established acceptable limits are not exceeded while operating the inertia directional vibrator. The vibrator is suitable for silage preparation since it does not contaminate the fodder with dirt and gasoline products during operation. The proposed silage preparation method provides opportunities to use ecologically safe containers as well as sectional and other types of enclosure

Investigation of grain separation through straw layer over …

Straw walker is a separator that separates grain from straw, and limits the efficiency of combine-harvesters therefore special attention is devoted to the development and improvement of its design and technological parameters. The most important parameter of walker operation is Froude-number k that depends on the amplitude of the straw walker movement in vertical direction, i.e., walker sieve oscillation amplitude r and angular velocity ω. High speed camera used in the investigation tests helped to determine not only the behavior of the straw layers on the oscillating sieve of straw walker but also the duration of grain penetration (separation) through the straw. With estimation of these parameters the rational values of Froude-number k were substantiated. It has been determined that at various ω and r combinations when k=const. sieve vertical accelerations when the crankshaft is rotated at the same angle are equal, but speeds and displacements are varied. For this reason the duration of grain separation is different. The rational angular velocity of the crankshaft is 22.5 s-1 (r=0.05 m), as then the straw layer when the crankshaft is rotated at the angle 2π, raised from the walker surface (sieve) the most early and strokes with it latest, i.e. the duration of free movement of the straw is 1.5 times longer and the grain separation about 15% more intensive than when ω=21.5 s-1. The estimation of grain separation enabled to define critical value of crankshaft angular velocity equal to ω=23.5 s-1. When this value is exceeded the top straw layers receive only one stroke when the crankshaft is rotated at the angle 4π, therefore the increase of crankshaft angular velocity and, simultaneously, sieve oscillation intensity above the critical value is inexpedient

Vibration and noise measurements during silage thickening with inertia directional vibrator

Literature review and performed theoretical investigation indicates that it is environmentally and economically feasible for small and average size farms to use vibrational thickening method for silage preparation. However, the results need to be verified with experiments. This research work provides analysis and evaluation of flat surface inertia type vibrator, in which the excitation force is induced by turning the unbalanced mass. Directed action vibrator was manufactured and tested. Results indicate that application of inertia directional vibrator for thickening of finely chopped corn and Jerusalem artichoke stalk mixture, after 40 minutes thickening, allows to obtain a 114.6 kg m-3 density for both layers, while thickening the first 65 kg mass mixture layer after 10 minutes - a 197.9 kg m-3 density. Dry material densities correspond to 61.5 and 106.3 kg m-3 respectively. After examination of fodder quality it was determined that corn mixture silage, thickened by the inertia directional vibrator, satisfies highgrade silage requirements. Performed tests demonstrated that the effect of vibrations on whole body and the measured noise levels do not have detrimental effect on human health and the established acceptable limits are not exceeded while operating the inertia directional vibrator. The vibrator is suitable for silage preparation since it does not contaminate the fodder with dirt and gasoline products during operation. The proposed silage preparation method provides opportunities to use ecologically safe containers as well as sectional and other types of enclosure

Alumoxane/ferroxane nanoparticles for the removal of viral pathogens: the importance of surface functionality to nanoparticle activity

A bi-functional nano-composite coating has been created on a porous Nomex fabric support as a trap for aspirated virus contaminated water. Nomex fabric was successively dip-coated in solutions containing cysteic acid functionalized alumina (alumoxane) nanoparticles and cysteic acid functionalized iron oxide (ferroxane) nanoparticles to form a nanoparticle coated Nomex (NPN) fabric. From SEM and EDX the nanoparticle coating of the Nomex fibers is uniform, continuous, and conformal. The NPN was used as a filter for aspirated bacteriophage MS2 viruses using end-on filtration. All measurements were repeated to give statistical reliability. The NPN fabrics show a large decrease as compared to Nomex alone or alumoxane coated Nomex . An increase in the ferroxane content results in an equivalent increase in virus retention. This suggests that it is the ferroxane that has an active role in deactivating and/or binding the virus. Heating the NPN to 160 C results in the loss of cysteic acid functional groups (without loss of the iron nanoparticleﾒs core structure) and the resulting fabric behaves similar to that of untreated Nomex , showing that the surface functionalization of the nanoparticles is vital for the surface collapse of aspirated water droplets and the absorption and immobilization of the MS2 viruses. Thus, for virus immobilization, it is not sufficient to have iron oxide nanoparticles per se, but the surface functionality of a nanoparticle is vitally important in ensuring efficacy

Genotyping a second growth coast redwood forest : a high throughput methodology

The idea that excitonic (electronic) coherences are of fundamental importance to natural photosynthesis gained popularity when slowly dephasing quantum beats (QBs) were observed in the two-dimensional electronic spectra of the Fenna–Matthews–Olson (FMO) complex at 77 K. These were assigned to superpositions of excitonic states, a controversial interpretation, as the strong chromophore–environment interactions in the complex suggest fast dephasing. Although it has been pointed out that vibrational motion produces similar spectral signatures, a concrete assignment of these oscillatory signals to distinct physical processes is still lacking. Here we revisit the coherence dynamics of the FMO complex using polarization-controlled two-dimensional electronic spectroscopy, supported by theoretical modelling. We show that the long-lived QBs are exclusively vibrational in origin, whereas the dephasing of the electronic coherences is completed within 240 fs even at 77 K. We further find that specific vibrational coherences are produced via vibronically coupled excited states. The presence of such states suggests that vibronic coupling is relevant for photosynthetic energy transfer

Methylation levels of a novel genetic element, EgNB3 as a candidate biomarker associated with the embryogenic competency of oil palm

The association between DNA methylation status and embryogenic competency in oil palm tissue culture was examined through Representational Difference Analysis (RDA) approach, using methylation-sensitive restriction endonucleases. "Difference Products" (DPs) of RDA derived from palms of similar genetic backgrounds but exhibiting different embryogenesis rates during the regeneration process were isolated. The DPs were sequenced using a pyrosequencing platform. To our knowledge, this is the first study profiling partial HpaII methylation sites in oil palm young leaf tissues which are potentially associated with embryogenic amenability through a genomic subtractive approach. Quantitative real-time PCR analysis demonstrated that the methylation status of a novel fragment, EgNB3, was higher in highly embryogenic leaf explants compared to low embryogenesis rate materials. These differences are likely to be contributed by the 5′-mCCGG-3′ and/or 5′-mCmCGG-3′ methylation patterns. Our data suggest that the differentially methylated site in EgNB3 has potential as a molecular biomarker for the screening of oil palm leaf explants for their embryogenic potentials