Increasing the efficiency of drying cellulose by ultrasonic influence

Relevance. Significant part of renewable and fossil energy resources is spent to generate heat and electricity needed to implement drying. At the same time, cellulose drying, due to the large-tonnage production, is one of the significant consumers of energy resources. One of the ways to reduce energy costs of drying is ultrasonic vibrations impact. There are practically no studies on ultrasonic exposure during cellulose drying. Therefore, it is necessary to consider possible options for non-contact ultrasonic treatment during convective drying of wood cellulose. Main aim. To identify the most rational options for placing the material to be dried, taking into account the direction of exposure to ultrasonic vibrations and the flow of warm air relative to the layers of the material to be dried at different temperatures. Objects. Non-contact ultrasonic action on wood cellulose. Methods. Mathematical modeling based on the finite element method was used to determine the distribution of oscillation amplitudes of a disk radiator. In the experimental part of the research, a material moisture content was determined by the weight method using verified technical means. Results. When ultrasonic vibrations have parallel direction relative to cellulose thin layers, a 2.5-fold reduction in drying time was shown at a sound pressure level of 162 ±3 dB and a drying agent temperature of 60 °C. The authors have found that temperature decrease of a drying agent makes it possible to increase the relative efficiency of ultrasonic treatment. An assessment of energy efficiency showed that the use of ultrasonic exposure leads to a 2.3-fold decrease in the energy spent on drying compared to only convective drying, all other things being equal. The conducted studies confirmed the effectiveness of the ultrasonic drying method for industrial use and made it possible to recommend options for the most rational placement of the material to be dried when designing the structures of drying chambers

Effect of high-intensity ultrasonic field on fog droplet coagulation efficiency

The relevance. The urgent need to deal with fog for preventing limited visibility and creating improved meteorological conditions. Exposure to gas dispersed systems by mechanical vibrations of the ultrasonic frequency can be considered as the most effective way to deal with fog formation. However, the acoustic method has not found an industrial application for fog destruction mainly due to the lack of effective sources of acoustic exposure. Therefore, it is necessary to create emitters of higher power that provide a significantly greater range of radiation with a sound pressure level of at least 140 dB and study of their functionality. The main aim. Determination of the effectiveness of fog destruction through the use of ultrasonic vibrations generated by the developed ultrasonic emitters; identification of the most promising design of ultrasonic equipment that ensures effective destruction of fogs in open areas. Objects. Combining fog droplets under high-intensity ultrasonic exposure using specially designed ultrasonic emitters for gas media of four types. Methods. Experimental method for studying fog droplets combination under the influence of ultrasonic vibrations and their gravitational deposition. To determine the aerosol (water content and disperse composition) characteristics, during experimental studies, the authors have used the TIPAS-1 meter based on the method of small-angle scattering and the method of spectral transparency. Results. The authors established and shown the effectiveness of ultrasonic effect on fogs, as well as the possibility of its use for fog destruction in an open area. All developed disc ultrasonic emitters are capable of forming a sound pressure level within 140... 145 dB at 22±2.0 kHz. The time of fog natural destruction in the aerosol chamber is reduced by up to 11.5 times. The results obtained demonstrate that it is necessary to use more powerful disc emitters, since they can significantly reduce the time of fog destruction and increase the volumes voiced at the same time. The minimum time for establishing the required metrological range of visibility is provided by means of a directional emitter with a stepped-variable surface, forming a flat wave

Improving the separation efficient of particles smaller than 2.5 micrometer by combining ultrasonic agglomeration and swirling flow techniques.

The method for increasing the separation efficiency of particles smaller than 2.5 micrometers by combined ultrasonic agglomeration and swirling flow technique is proposed in the article. The swirling flow creates areas with an increased concentration of particles on the outer radius of the vortex. The ultrasonic exposure on these areas leads to more efficient agglomeration and the formation of agglomerates of many times larger than the original particles. The resulting agglomerates are easily separated from the gas flow. The design of the agglomerator was developed. The vortex velocity is determined, at which ultrasonic exposure on the swirling flow increases the average particle size d32 = 2.5 micrometer to 4.5 times. The ultrasonic exposure on a rectilinear flow can increase the particle size no more than 1.6 times for comparison. The proposed method is compared with inertial gas clearing in a cyclone. It was found that the proposed combined method allows increasing the cleaning efficiency from 46% to 85% at ultrasonic exposure on the swirling flow in the agglomerator and cyclone

XIV INTERNATIONAL CONFERENCE AND SEMINAR OF YOUNG SPECIALISTS ON MICRO / NANOTECHNOLOGIES AND ELECTRON DEVICES EDM 2013 U-SONIC.RU -Лаборатория акустических процессов и аппаратов БТИ АлтГТУ Центр ультразвуковых технологий Development of the Equipment For

Abstract -The article is devoted to the development of the equipment for contact-free energy action of high-intensity ultrasonic vibrations for practical treatmnet of biological tissues with simeltaneous spraying of medicines. The model of the apparatus, which was able to provide necessary treatment of biological tissues, was developed. The results of measurements of distribution of ultrasonic vibration intensity of the disk radiator were obtained, disperse composition of the aerosol was determined

Особенности взаимосвязи редокс-метаболизма и структуры растений кальцефитов

Calciphyte species form a systematically and structurally heterogeneous group of plants capable of tolerating highly stressful conditions. Various structural adaptations occur in calciphytes to protect them against excess light (leaf pubescence) and moisture loss (waxy coating). Their shoot structure determines the volume of primary plant production. The present work studied the relationship between the antioxidant status and structural features of some calciphyte species. Redox metabolism in plant leaves was assessed using parameters such as water content, photosynthetic pigments, soluble carbohydrates, water-soluble phenolic compounds, water-soluble and membrane-bound proteins, and lipid peroxidation (LPO) level. The data obtained showed that the contents of the components regulating redox metabolism correlate both with each other and with the structural parameters of plants. In particular, the content of photosynthetic pigments in multi-species communities is lower in taller plants than in low-growing ones. The content of phenolic compounds and the level of LPO in calciphyte leaves are associated with the level of development of wax covering. The plants forming clumps and vigorous shoots exhibit increased LPO activityРастения кальцефитных флор образуют систематически и структурно неоднородную группу растений, способных переносить высокострессовые условия. Кальцефиты реализуют различные структурные адаптации, противодействуя избытку света (опушение), снижая потери влаги (восковой налет). Структура их побегов определяет объем первичной продукции растений. Цель настоящей работы – изучить взаимосвязи антиоксидантного статуса со структурными особенностями некоторых представителей кальцефитной флоры. Редокс-метаболизм оценивали по оводненности листьев, содержанию фотосинтетических пигментов, углеводов, фенольных соединений, водорастворимых и мембранно-связанных белков, интенсивности накопления продуктов перекисного окисления липидов (ПОЛ). Полученные данные показали, что количественное содержание компонентов, регулирующих редокс-метаболизм, демонстрирует наличие корреляционных связей к ак между о тдельными г руппами э тих в еществ, т ак и со структурными показателями растений. В частности, в многовидовых сообществах у более высоких растений содержание фотосинтетических пигментов ниже, чем у низкорослых. Содержание фенольных соединений и уровень ПОЛ в листьях кальцефитов связаны с уровнем развития воскового налета. Растения, формирующие куртины и мощные побеги, характеризуются повышенной активностью ПО

Direct observation of the dead-cone effect in quantum chromodynamics

The direct measurement of the QCD dead cone in charm quark fragmentation is reported, using iterative declustering of jets tagged with a fully reconstructed charmed hadron

HΛ3 and H‾Λ‾3 lifetime measurement in Pb–Pb collisions at √sNN=5.02 TeV via two-body decay

An improved value for the lifetime of the (anti-)hypertriton has been obtained using the data sample of Pb–Pb collisions at √sNN = 5.02 TeV collected by the ALICE experiment at the LHC. The (anti-)hypertriton has been reconstructed via its charged two-body mesonic decay channel and the lifetime has been determined from an exponential fit to the dN/d(ct) spectrum. The measured value, τ = 242+34 −38 (stat.) ± 17 (syst.) ps, is compatible with representative theoretical predictions, thus contributing to the solution of the longstanding hypertriton lifetime puzzle

Multiplicity dependence of inclusive J/ψ production at midrapidity in pp collisions at √s=13 TeV

Measurements of the inclusive J/ψ yield as a function of charged-particle pseudorapidity density dNch/dη in pp collisions at √s = 13 TeV with ALICE at the LHC are reported. The J/ψ meson yield is measured at midrapidity (|y| < 0.9) in the dielectron channel, for events selected based on the charged-particle multiplicity at midrapidity (|η| < 1) and at forward rapidity (−3.7 < η < −1.7 and 2.8 < η < 5.1); both observables are normalized to their corresponding averages in minimum bias events. The increase of the normalized J/ψ yield with normalized dNch/dη is significantly stronger than linear and dependent on the transverse momentum. The data are compared to theoretical predictions, which describe the observed trends well, albeit not always quantitatively

Multiplicity dependence of K*(892)0 and ϕ(1020) production in pp collisions at t √s=13 TeV

The striking similarities that have been observed between high-multiplicity proton-proton (pp) collisions and heavy-ion collisions can be explored through multiplicity-differential measurements of identified hadrons in pp collisions. With these measurements, it is possible to study mechanisms such as collective flow that determine the shapes of hadron transverse momentum (pT) spectra, to search for possible modifications of the yields of short-lived hadronic resonances due to scattering effects in an extended hadron-gas phase, and to investigate different explanations provided by phenomenological models for enhancement of strangeness production with increasing multiplicity. In this paper, these topics are addressed through measurements of the K∗(892)0 and φ(1020) mesons at midrapidity in pp collisions at √s = 13 TeV as a function of the charged-particle multiplicity. The results include the pT spectra, pT-integrated yields, mean transverse momenta, and the ratios of the yields of these resonances to those of longer-lived hadrons. Comparisons with results from other collision systems and energies, as well as predictions from phenomenological models, are also discussed