Specific Energy Levels Research Articles

Surface‐Plasmon‐Assisted Photoelectrochemical Reduction of CO2 and NO3− on Nanostructured Silver Electrodes

AbstractElectrochemical reduction of carbon dioxide (CO2) typically suffers from low selectivity and poor reaction rates that necessitate high overpotentials, which impede its possible application for CO2 capture, sequestration, or carbon‐based fuel production. New strategies to address these issues include the utilization of photoexcited charge carriers to overcome activation barriers for reactions that produce desirable products. This study demonstrates surface‐plasmon‐enhanced photoelectrochemical reduction of CO2 and nitrate (NO3−) on silver nanostructured electrodes. The observed photocurrent likely originates from a resonant charge transfer between the photogenerated plasmonic hot electrons and the lowest unoccupied molecular orbital (MO) acceptor energy levels of adsorbed CO2, NO3−, or their reductive intermediates. The observed differences in the resonant effects at the Ag electrode with respect to electrode potential and photon energy for CO2 versus NO3− reduction suggest that plasmonic hot‐carriers interact selectively with specific MO acceptor energy levels of adsorbed surface species such as CO2, NO3−, or their reductive intermediates. This unique plasmon‐assisted charge generation and transfer mechanism can be used to increase yield, efficiency, and selectivity of various photoelectrochemical processes.

A theory on the role of π-electrons of docosahexaenoic acid in brain function

Background: Docosahexaenoic acid (DHA) has been the dominant acyl component of the membrane phosphoglycerides in neural signaling systems since the origin of the eukaryotes. In this paper, we propose, this extreme conservation, is explained by its special electrical properties. Based on the Pauli Exclusion Principle we offer an explanation on how its six methylene interrupted double-bonds provide a special arrangement of π-electrons that offer an absolute control for the precision of the energy of the signal. Precision is not explained by standard concepts of ion movement or synaptic strengthening by enhanced protein synthesis. Yet precision is essential to visual acuity, truthful recall and the exercise of a dedicated neural pathway. Concept: Synaptic membranes have been shown to actively incorporate DHA with a high degree of selectivity. During a learning process, this biomagnification will increase the proportion of membrane DHA with two consequential neuronal and synaptic enhancements which build into a David Marr type model of the real world: DHA induced gene expression resulting in enhanced protein synthesis; increased density of π-electrons which could provide memory blocks and provide for the preferential flow of a current in neural pathways. Proposal: Both the above imply memory from synaptic strengthening. We propose memory is achieved by the activation of neuronal synaptic activation with synaptic turnover resulting in enhanced membrane DHA, which in turn induces gene expression, protein synthesis and π-electron density. Repetition amplifies the process activating synapses, which form a matrix representing the memory. The electro-chemical potentials then fire the electrons as electromagnetic waves via the six methylene interrupted double bonds. These allow transmission at a specific energy level based on their quantum mechanical properties providing the precision required for faithful recall. It is difficult to conceive of protein synthesis alone providing for precision. Using the principle of the dual properties of photons and electrons we develop the idea of complex wave patterns representing the visual or auditory fields. These are likely to be non-computable. We suggest that harmonization of the electromagnetic waves can result in cohesion explaining recall and associations. The cohesion of electromagnetic flow leads to a surge above the resting level, which is recognized by the brain as, demonstrated in artificial, electrical stimulus during neurosurgery.

Controlling the Electrical Characteristics of Charge Carrier Transporting Layers in Organic Light-Emitting Devices by the Host–Guest Structure: A Master Equation Approach

Controlling the electron and hole current is a crucial requirement in organic light-emitting devices (OLEDs) as it has a significant impact on the charge balance factor and the location of exciton generation zone. In this paper, via a self-consistent solution of the 3-D master equation approach coupled to Poisson’s equation, it is shown that the charge carrier and current density can be controlled in a wide range in OLEDs by utilizing a host–guest structure in the charge carrier transporting layers of the device. To this end, first, the impact of the injection energy barrier height, trap depth, and blending ratio on the charge carrier and current density is investigated. Second, the strategy of partially blending the hole or electron transporting material with an appropriate guest material is presented, and it is shown that by employing this strategy, current density can be enhanced over two orders of magnitude for high injection energy barriers, where the charge injection is most difficult. Moreover, this strategy guarantees that the transport of charge carriers to the emissive layer is conducted by the hole or electron transporting material itself rather than the guest material which is important as hole and electron transporting materials must fulfill other requirements such as high charge carrier mobility or specific excitonic energy levels.

A combined process of non-thermal plasma and a low-cost mineral adsorber for VOC removal and odor abatement in emissions of organic waste treatment plants

Gaseous emissions from organic waste treatment processes are substantial contributors to global ammonia and greenhouse gas emissions. Regarding complexity of the waste gas mixture, low concentration levels of the single compounds, and their high odor relevance, non-thermal plasma (NTP) processes are an adequate technique for the treatment of such emissions. However, performance tests of NTPs were mainly carried out with artificial low-volume gas flows and highly experimental plasma catalysts. A combined process of a non-thermal plasma and a readily available low-cost halloysite-containing mineral adsorber for VOCs removal and odor abatement was tested for emission treatment of two organic waste treatment plants. The process revealed average removal rates for VOCs, ammonia, and methane of 62.9 %, 15.9 %, and 30.1 % at the first site and 43.2 %, 22.2 %, and 34.8 % at the second site at specific input energy (SIE) levels of 2.1–2.2 kWh 1000 m−3. Additional odor analysis in the latter case revealed a high potential for odor abatement of 95.9–98.3 % at similar SIE levels.

Enhanced UV–Visible photocatalytic activity of Cu-doped ZnO/TiO2 nanoparticles

Cu–ZnO/TiO2 nanoparticles were prepared by entrapping copper ions into crystalline matrix of ZnO/TiO2 through sol–gel synthesis method. The photocatalyst matrix loaded with different copper concentrations was calcined at 500 and 700 °C. Thermal property, crystalline structure, surface morphology and absorption spectra of Cu–ZnO/TiO2 were characterized by thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, transmission electron microscope and UV–Vis spectrophotometry. Besides, its specific surface area and band gap energy level were estimated through BET surface area method, Kubelka–Munk model and Planck’s equation. The results revealed that Cu–ZnO/TiO2 had a more thermally stable lattice compared to TiO2/ZnO and hence the phase transformation from anatase to rutile is retarded under higher calcination temperature in Cu–ZnO/TiO2 lattice. The photoactivity of Cu–ZnO/TiO2 was then evaluated through degradation of methyl orange under visible light irradiation. Among different samples, the samples that were calcined at 500 °C exhibited the highest photocactivity compared to those calcined at 700 °C. Cu–ZnO/TiO2 with a Cu content of 3 wt% was observed to have the maximum activity, giving C/C0 value of 0.03 after 150 min. This value was about 12 and 28.3 times higher than that of ZnO/TiO2 and TiO2, respectively.

Effects of Quantum Confinements in Tin Sulphide Nanocrystals Produced by Wet-Solution Technique

In thin film nano-crystals studies, electron energy levels are known not continuous in the bulk thin films but are rather discrete(finite density of states) because of confinement of their electron wave functions to the physically dimensions of the particles. This phenomenon is called Quantum confinement and therefore nano-crystals are also referred to Quantum dots. The quantum confinement effect is mainly observed when the size of the particle involved is too small to be comparable to the wavelength of the electron. To understand this effect, this study broke the words confinement to mean to confine the motion of randomly moving electron to restrict its motion in specific energy levels (discreteness) and the term quantum to reflects the atomic realm of particles involved in this study. So as the size of a particle decrease to a nano scale, then the decrease in confining dimension causes the particle energy levels to be too discrete and at the same time widens up the band gap. As a result the ultimately effect is that the band gap energy increases. In this study, nanocrystalline tin sulphide (SnS) powder was prepared using tin chloride (SnCl2) as a tin ion (Sn+2) source and sodium sulfide (Na2S) as a sulfur (S-2) ion source using solution magneto DC sputtering technique. The as-synthesized thin film in form of nanoparticles were then qualitatively and quantitatively analyzed and characterized in terms of their morphological, structural and optical properties and found to have an orthorhombic structure whose direct band gap had blue shifted (1.74 eV) and was confirmed using theoretical calculations of exciton energy based on the potential morphing method (PMM) in the Hartree Fock approximation.

VOC removal and odor abatement by a low-cost plasma enhanced biotrickling filter process

A combined three stage waste air treatment system, consisting of a dielectric barrier discharge (non-thermal plasma), a low-cost zeolite adsorber, and a subsequent biotrickling filter, was investigated in respect to industrial practicability. Feasibility was proven by treatment of up to 1000m3*h−1 of emissions during sludge centrifugation in a waste water treatment plant under native conditions with ammonia and methane as the main compounds. In subsequent phases styrene, ethanol, n-butanol, 2-butoxyethanol, and gasoline were added as spiking components. Process parameters were pre-defined by a lab-scale plasma/adsorber system using ammonia, n-butanol, and methane as main compounds, and enhanced gas distribution after computational fluid dynamic simulation of the systeḿs geometry. Lab-scale tests without bioprocess at 300m3*h−1 showed a reduction of 31%, 44%, and 53% of the VOC content in matter of n-butanol feed, forming butyraldehyde as main intermediate, at specific input energy (SIE) levels of 2.8, 4.2, and 5.6kWh*1000m−3. Concentrations dropped by 76%, 98%, and 100% in case of n-butanol, and 41%, 56%, and 73% in case of ammonia at the same SIE levels. With exception of methane, VOCs as well as odor were efficiently eliminated by 50–100% and 60–94% in the pilot-scaled plasma/adsorber system at constant SIE levels of 2.0–2.2kWh*1000m−3. VOC removal and odor abatement were further improved to 95% or higher in combination with the subsequent bioprocess. Conversely, transformation of methane was negligible in both systems under these conditions.

Continuously flow microwave pre-treatment for enhanced anaerobic biodegradability of dairy industry sludge

Our research has focused on the investigation of the applicability of continuously flow microwave pre-treatment process for anaerobic digestion of dairy industry sludge. In the continuously flow operation effects of microwave specific process parameters, i.e. specific irradiated energy and microwave power level, were examined on the biogas yield and anaerobic digestion rate. Furthermore, the efficiency of process was characterized based on energetic analysis, as well. Our results show, that depend on the irradiated energy level the microwave power has effect on biogas yield, and determine the biodegradation rate, as well. Higher energy irradiation or higher power has been manifested in enhanced anaerobic digestion, but over a certain value of them led to worsened methane content. Considering the results obtained from energetic analysis can be concluded, that microwave pre-treatment followed by anaerobic digestion is efficient if irradiated energy was kept lower level (100 kJ L-1, in present experiments) with microwave power levels of 536 W, or 700W, respectively. Too high energy intensity at high power level, or too low microwave power, independently from the extent of irradiated energy, led to higher energy demand of pre-treatment, than can be recovered as energy content of surplus biogas.

Surfactant coupled sonic pretreatment of waste activated sludge for energetically positive biogas generation

The objective of this study was to evaluate the effect of dioctyl sodium sulphosuccinate (DOSS, a surfactant) on lysis rate of sludge and specific energy required for sonic pretreatment of waste activated sludge (WAS). Different ultrasonic power levels, WAS concentrations, DOSS dosages, and specific energy levels were used to compare pretreatment efficiencies. At an optimum time of 10min with ultrasonic power level of 160W, DOSS coupled sonic pretreatment resulted in better lysis rate (24.7%) of sludge than sonic pretreatment (17.6%). Biodegradability estimation through non-linear regression modeling revealed that DOSS coupled ultrasound pretreatment of sludge showed better biodegradability with higher hydrolysis constant (about 0.25d−1) than sonic pretreatment (0.19d−1). Nearly six times less energy was required for DOSS coupled ultrasound pretreatment compared to that required for sonic pretreatment. Therefore, DOSS coupled ultrasound pretreatment makes the pretreatment process energetically positive.

Quantifying K, U, and Th contents of marine sediments using shipboard natural gamma radiation spectra measured on DVJOIDESResolution

AbstractDuring International Ocean Discovery Program (IODP) expeditions, shipboard‐generated data provide the first insights into the cored sequences. The natural gamma radiation (NGR) of the recovered material, for example, is routinely measured on the ocean drilling research vessel DV JOIDES Resolution. At present, only total NGR counts are readily available as shipboard data, although full NGR spectra (counts as a function of gamma‐ray energy level) are produced and archived. These spectra contain unexploited information, as one can estimate the sedimentary contents of potassium (K), thorium (Th), and uranium (U) from the characteristic gamma‐ray energies of isotopes in the 40K, 232Th, and 238U radioactive decay series. Dunlea et al. (2013) quantified K, Th, and U contents in sediment from the South Pacific Gyre by integrating counts over specific energy levels of the NGR spectrum. However, the algorithm used in their study is unavailable to the wider scientific community due to commercial proprietary reasons. Here, we present a new MATLAB algorithm for the quantification of NGR spectra that is transparent and accessible to future NGR users. We demonstrate the algorithm's performance by comparing its results to shore‐based inductively coupled plasma‐mass spectrometry (ICP‐MS), inductively coupled plasma‐emission spectrometry (ICP‐ES), and quantitative wavelength‐dispersive X‐ray fluorescence (XRF) analyses. Samples for these comparisons come from eleven sites (U1341, U1343, U1366‐U1369, U1414, U1428‐U1430, and U1463) cored in two oceans during five expeditions. In short, our algorithm rapidly produces detailed high‐quality information on sediment properties during IODP expeditions at no extra cost.

Impact Detection and Characterization in Composite Laminates with Embedded Fiber Bragg Gratings

The use of composite materials has expanded significantly across civil, aerospace, and marine structures in both new designs and retrofits. The performance benefits from composites–typically, weight reduction with increased strength, corrosion resistance, and improved thermal and acoustic properties–are challenged by a host of failure modes whose genesis and progression aren’t yet well understood. As such, structural health monitoring (SHM) plays a key role for in-situ assessment for the purposes of performance/operations optimization, maintenance planning, and overall life cycle cost reduction. In this work, arrays of fiber Bragg grating optical strain sensors are embedded into a pre-preg composite specimen that was designed by surrogate finite element model simulation, and will be subjected to both low-energy (non-damaging) impacts at various locations and high-energy damaging impacts at a known location. The impactor was designed along with the panel specimen for very specific energy levels, strain frequency, and strain amplitude response. Results from SHM algorithms developed via hypothesis testing are demonstrated on blind impact tests in order to determine the efficacy of embedded fiber Bragg grating arrays for assessing structural health of such composites.

Effect of pulsed electric fields on the structure and frying quality of “kumara” sweet potato tubers

Abstract The aim of this research was to study the effect of pulsed electric fields (PEF) on the microstructure of “kumara” sweet potato ( Ipomoea batatas cv. Owairaka ) and its quality after frying. Whole sweet potato tubers were treated at different electric field strengths ranging from 0.3 to 1.2 kV/cm with specific energy levels between 0.5 and 22 kJ/kg. Cell viability was determined using tetrazolium staining to investigate the uniformity of the PEF effect across tubers. Based on the patterns of viable cells it was observed that the effect of PEF was not homogeneous across the tuber. This result was also supported by the pattern of enzymatic browning due to PEF facilitating the reaction of polyphenoloxidase and phenols. PEF treatment resulted in significant softening of the ground tissues, but not on the dermal tissues, as determined by texture analysis. With respect to frying quality, tubers pre-treated with PEF at electric field strength of 1.2 kV/cm and fried at 190 °C had an 18% lower oil content than non-PEF treated samples. The kinetics of browning as a function of frying time could be described by a fractional conversion model. The activation energy ( Ea ) of the browning rate during frying increased (more temperature sensitive) due to PEF pretreatment at 0.5 kV/cm and 1.2 kV/cm. It implies that PEF pretreatment allows frying the potato chips at lower temperature in order to achieve the same brown colour intensity as the non-PEF treated tubers. This study shows clearly that PEF could reduce the energy required for cutting and frying of kumara. Industrial relevance This study provides evidence that the effect of PEF processing on whole kumara tubers is not uniform, demonstrating heterogenous distribution. These findings provide important information for food industry to design appropriate PEF processing conditions for solid materials. More importantly, PEF treatment reduced the energy required for cutting and frying of kumara, and reduced the oil content in the fried kumara chips.

Transition Metal-Involved Photon Upconversion.

Upconversion (UC) luminescence of lanthanide ions (Ln3+) has been extensively investigated for several decades and is a constant research hotspot owing to its fundamental significance and widespread applications. In contrast to the multiple and fixed UC emissions of Ln3+, transition metal (TM) ions, e.g., Mn2+, usually possess a single broadband emission due to its 3d 5 electronic configuration. Wavelength‐tuneable single UC emission can be achieved in some TM ion‐activated systems ascribed to the susceptibility of d electrons to the chemical environment, which is appealing in molecular sensing and lighting. Moreover, the UC emissions of Ln3+ can be modulated by TM ions (specifically d‐block element ions with unfilled d orbitals), which benefits from the specific metastable energy levels of Ln3+ owing to the well‐shielded 4f electrons and tuneable energy levels of the TM ions. The electric versatility of d 0 ion‐containing hosts (d 0 normally viewed as charged anion groups, such as MoO6 6‐ and TiO4 4‐) may also have a strong influence on the electric dipole transition of Ln3+, resulting in multifunctional properties of modulated UC emission and electrical behaviour, such as ferroelectricity and oxide‐ion conductivity. This review focuses on recent advances in the room temperature (RT) UC of TM ions, the UC of Ln3+ tuned by TM or d 0 ions, and the UC of d 0 ion‐centred groups, as well as their potential applications in bioimaging, solar cells and multifunctional devices.

Substantiation of installation angle of inclined wall of charging hopper of a root chopper

Tuberous roots obviously benefit in comparison with other feeds, due to the high level of specific volume energy, productivity and good digestibility. When they are mixed with other components, the palatability of finished mixtures for animals increases. The quantity of digestible nutrients in tuberous roots can reach up to 90%. To make the nutrients more fully digested by animals, the correct preparation for feeding is necessary, including chopping. One of the problems of roots cutting process is the increased exudation, which results in undue losses of vitamins. Therefore creation of choppers providing the required quality of finished product is a crucial task. The aim of the research is to determine the optimum angle of inclination of the wall of charging hopper depending on the size of tuberous roots and on the offset of horizontal knife of a chopper. Brief description of the developed chopper of tuberous roots is given, as well as the sources of information containing the detailed description of the installation and its operation principles. In the process of theoretical calculations, the scheme of all forces acting in the moment of tuber pinching between the wall of charging hopper and the horizontal knife is drawn; the chain of discourse and theoretical reasoning are shown in detail. As a result of calculations, the analytical dependences are obtained through which assigning the thickness of slices and sizes of chopped tubers, it is possible to calculate the desired inclination angle of wall of charging hopper. Under estimated values, the tuber does not roll over the cutting knife, and the deformation is minimal. Therefore the exudation decreases, and nutrients losses are minimal. On the basis of the derived dependence, the graphs and their analysis are given.

Reverse strain-induced martensitic transformation of the ferrite to austenite in duplex stainless steels

The possibility of a reverse strain-induced martensitic transformation (RSIMT) of ferrite into austenite was evaluated in two duplex stainless steels (DSS) solution treated at 1000, 1100, and 1200 °C. For each temperature, we evaluated the effect of stress–strain state (tensile tests—triaxial; compression tests—uniaxial, and plate rolling—biaxial) on the reverse martensitic transformation behavior. For each strain level, the ferrite volume fraction was measured with a ferritscope, and finite element analyses allowed the correlation of the stress–strain states to the total transformed ferrite. X-ray diffraction and metallographic analyses showed that microstructures of all samples are composed only by ferrite and austenite, and the general trend of lower ferrite contents associated to higher strains corroborates the hypothesis of RSIMT of the ferrite in austenite. The amount of martensitic transformation is proportional to equivalent strain or to the respective strain energy, but different stress–strain states lead to different transformation behaviors. In the triaxial stress state during necking, the amount of transformed ferrite by RSIMT in a specific strain energy level is higher than that obtained in the biaxial stress state of the plate rolling, which in turn is higher than that observed for uniaxial stress state generated by compression tests. It can be then concluded that different strain states, and not only the amount of plastic deformation, affect the behavior of the RSIMT of ferrite in austenite of DSS.

Passivation of Molecular n‐Doping: Exploring the Limits of Air Stability

Molecular doping is a key technique for flexible and low‐cost organic complementary semiconductor technologies that requires both efficient and stable p‐ and n‐type doping. However, in contrast to molecular p‐dopants, highly efficient n‐type dopants are commonly sensitive to rapid degradation in air due to their low ionization energies (IEs) required for electron donation, e.g., IE = 2.4 eV for tetrakis(1,3,4,6,7,8‐hexahydro‐2H‐pyrimido[1,2‐a]pyrimidinato)ditungsten(II) (W2(hpp)4). Here, the air stability of various host:W2(hpp)4 combinations is compared by conductivity measurements and photoemission spectroscopy. A partial passivation of the n‐doping against degradation is found, with this effect identified to depend on the specific energy levels of the host material. Since host‐W2(hpp)4 electronic wavefunction hybridization is unlikely due to confinement of the dopant highest occupied molecular orbital (HOMO) to its molecular center, this finding is explained via stabilization of the dopant by single‐electron transfer to a host material whose energy levels are sufficiently low for avoiding further charge transfer to oxygen–water complexes. Our results show the feasibility of temporarily handling n‐doped organic thin films in air, e.g., during structuring of organic field effect transistors (OFETs) by lithography.

Near-infrared-to-near-infrared down-shifting and upconversion luminescence of KY3F10 with single dopant of Nd3+ ion

We have studied the structural and near-infrared (NIR) luminescent properties of KY3F10 phosphors, singly doped with Nd3+ serving as both sensitizer and activator. With a single laser diode at the wavelength of 808 nm as a pump source, simultaneous NIR-to-NIR upconversion (UC) and down-shifting (DS) emissions are effectively achieved, due to the specific energy levels of Nd3+ dopant and the low phonon energy of the host. The luminescence mechanism related to energy transfer is discussed. The luminescence can be modulated through controlling the population of Nd3+:4F3/2 state in our experiment. Interestingly, both UC and DS emissions of the material fall within the dual biological window, suggesting that the prepared phosphors have potential applications in the bioimaging field.

The Effect of Size and Shape on Breakage Characteristic of Mineral

Modelling used to describe the size reduction processes have undergoes significant advances in recent year. Industry demands for more detailed information regarding breakage particle for comminution process. However, comminution process is governed by a large number of factors that influence the breakage of particle. These papers present how to evaluate the effect of size and shape in single particle breakage of pegmatite. In this project, drop weight test was conducted to stimulate the single particle in comminution machine. The shapes of particle used are flaky and equidimensional shape. In drop weight test, the breakage characteristics of different size fractions can be examined at various input energy, Eis expressed in kWh/t. Relation between specific comminution energy level and the breakage index number (t10) was established on the size fractional based so that the variation in impact breakage characteristics of different particle shapes can be observed. From the result obtained, it has shown that the size and shape of particle do have influence on the breakage function.

Linking impact-related progeny sizes of cement clinker to modes of single-particle breakage

Fragmentation of particulate solids is an important process in many industrial activities, particularly in the mineral, cement and glass industries to comminute the raw materials to a required size. Understanding of processes and mechanisms responsible for fragmentation of particulate solids is a hard task. This may bring great precision for designing and controlling the comminution process. This work aims to contribute to understanding fragmentation of cement clinker particles under impact loading. For this purpose, six narrow-size classes of Portland clinker were fragmented with varying specific impact energy levels in a drop weight test apparatus. Then, breakage probabilities and functions of these size classes were determined from the product size distributions. The calculated breakage functions show evidences for the modes of breakage (meridian cracks to oblique cracks and shattering) given in the literature. Results of this study indicate that self-similarity of progeny size distributions can only be achieved, regardless of particle size and impact energy, if the particles have the same breakage probability, that is the same mode of breakage.

Study of soil aggregate breakdown dynamics under low dispersive ultrasonic energies with sedimentation and X-ray attenuation.

It has been increasingly recognized that soil organic matter stabilization is strongly controlled by physical binding within soil aggregates. It is therefore essential to measure soil aggregate stability reliably over a wide range of disruptive energies and different aggregate sizes. To this end, we tested high-accuracy ultrasonic dispersion in combination with subsequent sedimentation and X-ray attenuation. Three arable topsoils (notillage) from Central Europe were subjected to ultrasound at four different specific energy levels: 0.5, 6.7, 100 and 500 J cm-3, and the resulting suspensions were analyzed for aggregate size distribution by wet sieving (2 000-63 μm) and sedimentation/X-ray attenuation (63-2 μm). The combination of wet sieving and sedimentation technique allowed for a continuous analysis, at high resolution, of soil aggregate breakdown dynamics after defined energy inputs. Our results show that aggregate size distribution strongly varied with sonication energy input and soil type. The strongest effects were observed in the range of low specific energies (< 10 J cm-3), which previous studies have largely neglected. This shows that low ultrasonic energies are required to capture the full range of aggregate stability and release of soil organic matter upon aggregate breakdown.