Input Rate Research Articles

Process-based modeling of soil nitrous oxide emissions from United States corn fields under different management and climate scenarios coupled with evaluation using regional estimates

Direct emissions of soil nitrous oxide during a growing season (N2Ogs) can be quantified with process-based models considering interactions between management, climate, and soil moisture when key data are available. We used an adapted “parameterized CENTURY/DAYCENT-model” (pCENTURY) calibrated with crop growth and soil organic matter decay coefficients at the county-level for the estimation of N2Ogs in the United States Corn Belt. Model estimated N2O-emissions from corn-based biofuels scenarios considering crop rotation, fertilizer inputs, tillage, and weather were compared against meta-summary of field observations from 55 studies. Both model and meta-summary ranked N2Ogs-emissions to be corn > wheat > soybean phase while model likely underestimated cover crop N2Ogs-emissions. The N2Ogs-emissions and the associated emission factors (EFs) were modeled and summarized to be greater after anhydrous ammonia than urea application and from conventional tilled than non-tilled fields. Modeled and observed N2Ogs-emissions after organic and inorganic fertilizer amendment did not differ due to high variability associated with the treatments. However, the organic fertilizer associated EFs were greater according to meta-summary data because of N input rates. Regionalized weather scenarios indicate hotspots for N2Ogs-emissions can occur where crop N uptake is limited during dry years and in eastern states also during normal or wet seasons. The pCENTURY-derived N2Ogs EFs (0.91 ± 0.19%) for counties investigated were only slightly lower than literature (1.07 ± 0.57%) or Tier-1 (1%) values. Our preliminary evaluation of regional soil moisture estimates showed reasonable agreement between monthly soil moisture estimates and the North American Soil Moisture Dataset during the growing season, but overestimation of soil moisture in winter-spring can influence the estimates of annual N2O emissions so future work is needed to calibrate soil moisture-associated model parameters. Our work provided scenario-based estimates of climate and management impacts on soil N2Ogs-emissions together with valuable spatial insights into EFs that will be improved by more accurate information of fertilizer inputs and more temporally refined model evaluation.

Effects of Geologic Setting on Contaminant Transport in Deltaic Aquifers

AbstractCoastal deltaic aquifers are vulnerable to degradation from seawater intrusion, geogenic and anthropogenic contamination, and groundwater abstraction. The distribution and transport of contaminants are highly dependent on the subsurface sedimentary architecture, such as the presence of channelized features that preferentially conduct flow. Surface deposition changes in response to sea‐level rise (SLR) and sediment supply, but it remains unclear how these surface changes affect the distribution and transport of groundwater solutes in aquifers. Here, we explore the influence of SLR and sediment supply on aquifer heterogeneity and resulting effects on contaminant transport. We use realizations of subsurface heterogeneity generated by a process‐based numerical model, DeltaRCM, which simulates the evolution of a deltaic aquifer with different input sand fractions and rates of SLR. We simulate groundwater flow and solute transport through these deposits in three contamination scenarios: (a) vertical transport from widespread contamination at the land surface, (b) vertical transport from river water infiltration, and (c) lateral seawater intrusion. The simulations show that the vulnerability of deltaic aquifers to seawater intrusion correlates to sand fraction, while vertical transport of contaminants, such as widespread shallow contamination and river water infiltration, is influenced by channel stacking patterns. This analysis provides new insights into the connection between the depositional system properties and vulnerability to different modes of groundwater contamination. It also illustrates how vulnerability may vary locally within a delta due to depositional differences. Results suggest that groundwater management strategies may be improved by considering surface features, location within the delta, and the external forcings during aquifer deposition.

Suppression of humping bead in high-speed triple-wire gas indirect arc welding

Triple-wire gas indirect arc welding (TW-GIA) is a new technology with the advantages of low heat input and high deposition rate. However, the humping bead restricts the improvement of welding efficiency. In this article, the high-speed cameras and infrared thermal imaging system were used to characterize the formation mechanism of the TW-GIA humping bead. The physical model was established to discuss the force mechanism of the weld poor. And the influence of process parameters on humping bead was studied. The results show that the increase of the welding angle reduced the arc pressure and droplet impact force in the opposite direction of welding, which was beneficial to eliminate the hump. When the welding height was lower than 3 mm, the excessive arc pressure led to the humping bead with arc crater. When the welding height was greater than 20 mm, the distance between the droplets of side wires was far, forming the humping bead with “double bead” defect. In addition, the flow distance of the liquid metal shortened as the welding current decreased, which could suppress the humping bead. When the ratio of the total wire feeding speed to the welding speed was 10, the critical current was 360 A, and the critical current increased as the ratio increased. The maximum TW-GIA welding speed of bead-on-plate was 4.2 m/min, which was 137% higher than that of high-speed GMAW.

Arbuscular mycorrhizal hyphal respiration makes a large contribution to soil respiration in a subtropical forest under various N input rates

Arbuscular mycorrhizal fungi (AMF) are widespread in subtropical forests and play a crucial role in belowground carbon (C) dynamics. Nitrogen (N) deposition or fertilization may affect AMF and thus the flux of plant-derived C back to the atmosphere via AMF hyphae. However, the contribution of AMF hyphal respiration to soil respiration and the response AMF hyphal respiration to increased soil N availability remain unknown. We studied the effect of N fertilization (0, 50, 100 and 200 kg N ha−1 yr−1) on AMF hyphal respiration, root respiration and heterotrophic (microbial) respiration in a subtropical Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) plantation. We found that short-term N addition did not affect root, AMF hyphal and soil microbial respiration, because soil N availability and extraradical hyphae were not affected by N addition. The AMF hyphal respiration contributed 12 % of total soil respiration and 25 % of the autotrophic respiration. Root, AMF hyphal and soil microbial respiration were positively correlated with soil moisture content but not with soil temperature. Our results indicate that AMF hyphal respiration is a large source of soil respiration, and should be considered in partitioning soil respiration into different components in future studies to better understand the response of soil respiration to N addition.

Dynamics-based machine learning of transitions in Couette flow

We derive low-dimensional, data-driven models for transitions among exact coherent states (ECSs) in one of the most studied canonical shear flows, the plane Couette flow. These one- or two-dimensional nonlinear models represent the leading-order reduced dynamics on attracting spectral submanifolds (SSMs), which we construct using the recently developed SSMLearn algorithm from a small number of simulated transitions. We find that the energy input and output rates provide efficient parametrizations for the most important SSMs. By restricting the dynamics to these SSMs, we obtain reduced-order models that also reliably predict nearby, off-SSM transitions that were not used in their training.

IN-SITU WATER HARVESTING TECHNOLOGIES AND FERTILIZER RATES INCREASE MAIZE AND BEAN YIELDS IN THE SEMI-ARID KATUMANI, KENYA

<p><strong>Background: </strong>Crop production in the arid and semi-arid lands (ASALs) is constrained by erratic rainfall and poor soil fertility. Therefore, climate smart agriculture mechanisms such as <em>in-situ</em> rainwater harvesting technologies and recommended fertilizer rates would be vital for ensuring food security.<strong> Objective</strong>: To evaluate selected <em>in-situ</em> water harvesting technologies and fertilizer rates on soil water content and yield of maize and beans at KALRO Katumani Research Center in Machakos County, Kenya during the 2019 and 2020 short and long rain seasons, respectively. <strong>Methodology:</strong> The experiment was established in a randomized complete block design with a split-split plot arrangement, replicated three times, with <em>in-situ</em> water harvesting technologies comprising of zai pits, ngolo pits, contour furrows and conventional tillage, as the main plots, whereas the split plots were varying rates of fertilizer inputs: Di-ammonium phosphate (DAP), goat manure and control. The split-split plots comprised of maize and beans cropping systems. Soil moisture content was assessed at 4, 8, 12 and 16 weeks after emergence, whilst nutrient uptake, use efficiency and crop yields at physiological maturity. Data was subjected to analysis of variance. <strong>Results: </strong>Soil moisture, maize and beans yields, nutrient uptake and use efficiency were significantly (p<em> </em>≤ 0.05) increased by <em>in-situ</em> water harvesting technologies and fertilizer inputs. Highest soil moisture content was recorded under zai and ngolo pits and lowest in conventional tillage treatments. Ngolo pits recorded higher maize and beans grain yield. Application of DAP fertilizer increased maize and beans grain yield compared to control. Intercropping maize and beans increased grain yield significantly (p<em> </em>≤ 0.05) compared to sole maize and sole beans. <strong>Implications. </strong>There is need for promoting a combination of <em>in-situ</em> rainwater harvesting technologies especially ngolo and zai pits with application of DAP+ manure in semi-arid areas where water is scarce coupled with poor soil fertility. <strong>Conclusion:</strong> Ngolo and zai pits increased soil water retention capacity while application of DAP fertilizer led to increased crop yield and the study therefore recommends their adoption within the study area and extrapolation to areas of similar conditions. </p>

Radiocesium accumulation in Lake Kasumigaura by riverine input and migration following the Fukushima Dai-ichi nuclear power plant accident

Vertical radiocesium concentration profiles and inventories in sediments were measured in Lake Kasumigaura following the 2011 Fukushima Dai-ichi Nuclear Power Plant accident. Further measurements of radiocesium concentrations in suspended solids (SS) have been conducted since September 2012 in the Koise and Sakura rivers inflowing into the lake. Cesium-137 (137Cs) accumulated intensively near the inflow outlets in the lake. At the lake center, the 137Cs inventory in sediments increased during 2011–2014; however, few changes were observed during 2014–2016. The 137Cs surface concentration and inventory decreased considerably in Tsuchiura-iri Bay until 3 years after the accident, indicating 137Cs migration. However, the rate of decrease subsequently slowed due to the 137Cs supply from the river. The 137Cs concentration in river SS declined during 2012–2015; however, it remained 1–2 orders of magnitude above its pre-accident level. The entrainment coefficient of particulate 137Cs in the inflows was initially higher in the Koise River but decreased exponentially more rapidly in the Koise River than in the Sakura River until 2015. Therefore, in the future, the difference in 137Cs concentrations will be smaller. The 137Cs concentration in the Koise River will continue to decrease; thus, the difference in the 137Cs inventory between the northern and southern parts of the lake will decrease. Total estimated amounts of 137Cs in the entire lake were 3.72 × 1012 Bq in December 2012 and 4.18 × 1012 Bq in August 2016. The accumulated amount of 137Cs in the entire lake based on sediment analysis was similar to the riverine input of particulate 137Cs based on riverine SS analysis from December 2012‒;August 2016, confirming the high trapping performance of the lake for particulate matter provided by the basin. Moreover, the amount of 137Cs accumulated in the lake in 2016 may have originated from comparable rates of atmospheric deposition and riverine input. These findings provide useful insights for future prediction and management of radiocesium contamination and the effects of riverine inputs in general shallow lakes.

Controls on labile and stabilized soil organic matter during long-term ecosystem development

A better understanding of factors controlling the distribution of soil organic matter (SOM) in differently stabilized pools in soils during ecosystem development is essential to more efficiently manage soil as a C sink and aid global warming mitigation. We, thus, investigated C and N stocks in bulk soil and differently stabilized soil fractions (free particulate organic matter (fPOM), micro- and macroaggregates, and mineral-associated organic matter (MAOM)), in seven chronosequences comprising primary and secondary successions at various locations in Europe and tested the influence of multiple environmental parameters on these C and N stocks.Best-subset multiple regression indicated that plant litter production and succession age were of minor importance. Above a certain threshold of organic matter inputs to the soil, changes in the quantity of such inputs may have little direct effect on the partitioning of organic matter to various soil fractions. Instead, biophysicochemical soil properties (such as pH and PLFA and clay contents) were the best predictors for both C and N stocks. We also found a shift in the relevance of biotic and abiotic factors from fPOM and the various aggregate fractions to MAOM, the latter being exclusively associated with pH and the clay content. This indicates that sites dominated by MAOM likely more slowly react to management interventions, such as increasing or diversifying organic matter inputs, than sites dominated by fractions more responsive to biotic factors, such as fPOM. Finally, as compared to primary successions, secondary successions were associated with higher C and N stocks in aggregate fractions, pointing towards better conditions for soil structure formation in the latter. Our results highlight the need to elucidate the form in which C and N exist in the soil for selection of proper management strategies and that soil biophysicochemical parameters may have a disparately larger impact on the partitioning of C and N to variously stabilized soil fractions than the rate of organic matter inputs.

Increasing nitrogen addition rates suppressed long-term litter decomposition in a temperate meadow steppe

AbstractPlant litter decomposition is critical for the carbon (C) balance and nutrient turnover in terrestrial ecosystems, and is sensitive to the ongoing anthropogenic biologically nitrogen (N) input. Previous studies evaluating the N effect on litter decomposition relied mostly on short-term experiments (<2 years), which may mask the real N effect on litter decomposition. Therefore, long-lasting experiments are imperative for the overall evaluation of the litter decomposition dynamics under N enrichment. We conducted a relative long-term (4-year) N-addition experiment with N levels ranging from 0 to 50 g N m−2 yr−1 to identify the potential abiotic and biotic factors in regulating the decomposition process of litterfall from the dominant species Leymus chinensis. The results showed a consistent decrease of decomposition rate with increasing N-addition rates, providing strong evidence in support of the inhibitory effect of N addition on decomposition. The N-induced alterations in soil environment (acidification and nutrient stoichiometry), microbial activity (microbial biomass and enzyme activity), changes of litter quality (residual lignin and nutrient content) and plant community (aboveground productivity and species richness) jointly contributed to the lowered decomposition. During the whole decomposition process, the changes of litter quality, including accumulation of lignin and the concentrations of nutrient, were mainly driven by the soil and microbial activity in this N-enriched environment. The findings help clarify how increasing N input rates affect long-term litter decomposition, and advance the mechanistic understanding of the linkages between ecosystem N enrichment and terrestrial C cycling.

Characteristics of nitrogen deposition research within grassland ecosystems globally and its insight from grassland microbial community changes in China.

As global change continues to intensify, the mode and rate of nitrogen input from the atmosphere to grassland ecosystems had changed dramatically. Firstly, we conducted a systematic analysis of the literature on the topic of nitrogen deposition impacts over the past 30 years using a bibliometric analysis. A systematic review of the global research status, publication patterns, research hotspots and important literature. We found a large number of publications in the Chinese region, and mainly focuses on the field of microorganisms. Secondly, we used a meta-analysis to focus on microbial changes using the Chinese grassland ecosystem as an example. The results show that the research on nitrogen deposition in grassland ecosystems shows an exponential development trend, and the authors and research institutions of the publications are mainly concentrated in China, North America, and Western Europe. The keyword clustering results showed 11 important themes labeled climate change, elevated CO2, species richness and diversity, etc. in these studies. The burst keyword analysis indicated that temperature sensitivity, microbial communities, etc. are the key research directions. The results of the meta-analysis found that nitrogen addition decreased soil microbial diversity, and different ecosystems may respond differently. Treatment time, nitrogen addition rate, external environmental conditions, and pH had major effects on microbial alpha diversity and biomass. The loss of microbial diversity and the reduction of biomass with nitrogen fertilizer addition will alter ecosystem functioning, with dramatic impacts on global climate change. The results of the study will help researchers to further understand the subject and have a deep understanding of research hotspots, which are of great value to future scientific research.

Age and ageing cardiovascular collection: blood pressure, coronary heart disease and heart failure.

As people age they are at increased risk of cardiovascular disease, the leading cause of mortality and morbidity worldwide. Understanding cardiovascular ageing is essential to preserving healthy ageing and preventing serious health outcomes. This collection of papers published in Age and Ageing since 2011 cover key themes in cardiovascular ageing, with a separate collection on stroke and atrial fibrillation planned. Treating high blood pressure remains important as people age and reduces strokes and heart attacks. That said, a more personalised approach to blood pressure may be even more important as people age to lower blood pressure to tight targets where appropriate but avoid overtreatment in vulnerable groups. As people age, more people experience blood pressure drops on standing (orthostatic hypotension), particularly as they become frail. This can predispose them to falls. The papers in this collection provide an insight into blood pressure and orthostatic hypotension. They highlight areas for further research to understand blood pressure changes and management in the ageing population. Inpatient clinical care of older people with heart attacks differs from younger people in UK national audit data. People aged over 80 had improved outcomes in survival after heart attack over time, but had lower rates of specialist input from cardiology compared with younger people. This may partly reflect different clinical presentations, with heart attacks occurring in the context of other health conditions, frailty and multimorbidity. The care and outcomes of acute and chronic cardiovascular disease are impacted by the frailty and health status of an individual at baseline. The research included in this collection reinforces the wide variations in the ageing population and the necessity to focus on the individual needs and priorities, and provide a person-centred multidisciplinary approach to care.

Multimodal Event Processing: A Neural-Symbolic Paradigm for the Internet of Multimedia Things

With the Internet of Multimedia Things (IoMT) becoming a reality, new approaches are needed to process real-time multimodal event streams. Existing approaches to event processing have limited consideration for the challenges of multimodal events, including the need for complex content extraction, and increased computational and memory costs. This article explores event processing as a basis for processing real-time IoMT data. This article introduces the multimodal event processing (MEP) paradigm, which provides a formal basis for native approaches to neural multimodal content analysis (i.e., computer vision, linguistics, and audio) with symbolic event processing rules to support real-time queries over multimodal data streams using the multimodal event processing language to express single, primitive multimodal, and complex multimodal event patterns. The content of multimodal streams is represented using multimodal event knowledge graphs to capture the semantic, spatial, and temporal content of the multimodal streams. The approach is implemented and evaluated within a MEP engine using single and multimodal queries achieving near real-time performance with a throughput of ~30 frames processed per second (fps) and subsecond latency of 0.075–0.30 s for video streams of 30 fps input rate. Support for high input stream rates (45 fps) is achieved through content-aware load-shedding techniques with a ~127X latency improvement resulting in only a minor decrease in accuracy.

The combined effect of sowing methods and nitrogen rates on wheat yield and regulation of soil water consumption in Loess Plateau

Field experiments were conducted to assess the effect of four sowing methods on the growth, photosynthetic, and yield traits of dryland winter wheat. Furthermore, the impact of N input rates was also evaluated on water consumption by the wheat plants from the soil. The seeds of winter wheat were sown using wide space sowing (WS), furrow sowing (FS), stereoscopic sowing (SS), and drill sowing (DS). The results indicated that different sowing methods significantly affected the yield and grain quality. The increase in grain yield was 25%, 17%, and 11%, respectively, under WS, FS, and SS compared to that in DS. From sowing to jointing, the water consumption was highest under WS, mainly in deep soil layers. The photosynthetic traits and leaf area index were highest under WS, followed by those under FS. The plant height was highest under DS. The water consumption index and grain yield were higher at the N rate 210-240 kg ha-1 than those at the other N rates applied. In conclusion, the WS and 210 kg N ha-1 improved the canopy structure, water consumption, and winter wheat yield.

Rye containing compound feeds in the diet of bulls on rearing

Relevance. Rye occupies a special place among cereals as components of compound feeds. Rye, unsuitable for food purposes, but quite suitable for feeding farm animals, can be used for the production of compound feeds.Methods. To solve the problems, 4 groups of gobies were formed for rearing and 4 recipes of compound feed concentrates with different rye input rates were developed (0, 20, 30, 40%). The duration of the experiment was 135 days. To find out the effect of the compound feed composition on feed consumption, daily group feeding accounting was carried out. Experimental animals were weighed every 30 days, that is, monthly. To identify the effect of the tested grain (rye) consumption of the basic balanced diet, records were kept on the account of the feed consumed and their residues the next day. During the entire scientific and economic experience, feedabilitywas recorded.Results. Studies have shown that compound feeds prepared according to the developed recipes allow balancing the feeding of experimental bulls that will be raised to produce beef according to the detailed feeding standards available today, with a relatively low specific gravity of concentrated feeds. The inclusion of 20 to 40% rye in the composition of compound feeds does not reduce the balance of the diet of animals in the experiment. The gross increase in live weight and the increase per day in the experimental bulls of the first three groups did not differ significantly. Animals from group IV, which were fed compound feed with 40% rye, were inferior to control animals by 5.6 kg in total growth, in an average daily increase — by43 g. 5.87–6.03 ECU was spent per unit of live weight gain (1 kg).

Shallow magma dynamics at open-vent volcanoes tracked by coupled thermal and SO2 observations

Open-vent volcanic activity is typically sustained by ascent and degassing of shallow magma, in which the rate of magma supply to the upper feeding system largely exceeds the rate of magma eruption. Such unbalance between supplied (input) and erupted (output) magma rates is thought to result from steady, degassing-driven, convective magma overturning in a shallow conduit/feeding dyke. Here, we characterize shallow magma circulation at Stromboli volcano by combining independent observations of heat (Volcanic Radiative Power; via satellite images) and gas (SO2, via UV camera) output in a temporal interval (from August 1, 2018 to April 30, 2020) encompassing the summer 2019 effusive eruption and two paroxysmal explosions (on July 3 and August 28, 2019). We show that, during the phase of ordinary strombolian explosive activity that preceded the 2019 effusive eruption, the average magma input rate (0.1-0.2 m3/s) exceeds the magma eruption rate (0.001-0.01 m3/s) by ∼2 orders of magnitude. Conversely, magma input and output rates converge to an average of ∼0.4 m3/s during the summer 2019 summit effusion, implying an overall suppression of magma recycling back into the feeding system, and hence of excess degassing. We find that, during the effusive eruption, the peak in SO2 emissions lags behind the thermal emission peak by ∼27 days, suggesting that magma output, feeding the lava flow field, initially dominates over magma input in the conduit. We propose that this conduit mass unloading, produced by this initial phase of the effusive eruption, leads to an overall decompression (of up to 30 Pa/s) of the shallow plumbing system, ultimately causing ascent of less-dense, volatile-rich magma batch(es) from depth, enhanced explosive activity, and elevated SO2 fluxes culminating into a paroxysmal explosion on August 28. Our results demonstrate that combined analysis of thermal and SO2 flux time-series paves the way to improved understanding of shallow magmatic system dynamics at open-vent volcanoes, and of the transition from explosive to effusive activity regimes.

Guidance of the resonance energy flow in the mechanism of coupled magnetic pendulums

This paper presents a methodology of controlling the resonance energy exchange in mechanical system consisting of two weakly coupled magnetic pendulums interacting with the magnetic field generated by coils placed underneath. It is shown that properly guided magnetic fields can effectively change mechanical potentials in a way that the energy flow between the oscillators takes the desired direction. Studies were considered by using a specific set of descriptive functions characterizing the total excitation level, its distribution between the pendulums, and the phase shift. The developed control strategies are based on the observation that, in the case of antiphase oscillation, the energy is moving from the pendulum subjected to the repelling magnetic field, to the oscillator under the attracting field. In contrast, during the inphase oscillations, the energy flow is reversed. Therefore, closed-loop controller requires only the information about phase shift, which is easily estimated from dynamic state signals through the coherency index. Advantage of suggested control strategy is that the temporal rate of inputs is dictated by the speed of beating, which is relatively slow compared to the carrying oscillations.

Two-channel combination methods for count-loss correction in radiation measurements at high rates and with pulsed sources

Pile-up effects due to the overlap of signals within the system dead-time (τ) influence the counting capability of radiation detection devices, necessitating the use of correction algorithms to compensate for the count-losses at high radiation rates. Count-rate linearity is especially critical for clinical applications like X-ray imaging or beam monitoring in particle therapy. In particular, in proton therapy the number of delivered particles must be measured online during the treatment session with a maximum error of 1 % up to an average input beam flux of about 1010cm−2s−1. For a segmented detector used to identify and count the single beam particles, assuming a channel area of 1 mm2 and a dead-time τ=2ns, a maximum counting inefficiency of 1 % is required up to τ.fin=0.2 for each detector channel, where fin represents the input rate. Moreover, the beam is often delivered in bunches with higher instantaneous particle rates, and the saturation model of the detector and electronic chain could not be easily determined. Similar considerations are applicable for pixelated detectors used for photon counting.Two methods are proposed to mitigate counting inefficiencies with radiation sources of variable time-structures. Both methods are based on the collection of logic signals provided by two independent detector channels exposed to the same radiation field after discriminating the detector analog outputs with a fixed threshold, assuming that the duration of the discriminator output signal corresponds to the system dead-time. The correction algorithms employ the measurements of the time durations, the number of signals from the two channels and of their AND/OR combinations. The methods provide count-loss corrections without the need to know the dead-time model.The performances of the proposed algorithms are evaluated by using simulations of ideal boxcar signals of fixed duration τ, distributed randomly in time to emulate the dead-time behavior of the system. Both methods provide an effective count-loss correction with a maximum deviation of 1% for different input rates up to τ.fin=1, assuming a uniform random time distribution of input events for both paralyzable and non-paralyzable systems. The simulations of pulsed radiation fluxes provide the same results as a function of the instantaneous input rates.These results are similar to those obtainable by the standard live-time correction algorithm. However, the latter algorithm can only be applied to continuous particle fluxes, while the proposed algorithms work also for pulsed beams, without any hypothesis on the bunch duration or frequency. The robustness of the algorithms with respect to the resolution of the time measurement is studied and the potential limitations in more realistic systems are discussed.The algorithms can be easily implemented in standard logical circuits with multiple input signals provided by segmented detectors. Even if the methods are intended for real-time correction in beam particle counting, they could be applied in a wider range of applications of radiation measurements.

Cold ironing: modelling the interdependence of terminals and vessels in their choice of suitable systems

Cold ironing has the potential to reduce the impact of ship exhausts in densely populated areas. However, especially for tankers, the implementation of this concept is almost non-existent. Still, these vessels have a relatively high port energy use, despite relatively short port visits, as they provide power to both pumps and inert gas systems during unloading and loading. A key factor in the reluctance, besides the fact that a sparkless connection is required, is the lack of a standard and the uncertainty from both tanker owners visiting a berth and terminal owners on which shore power systems to apply. This paper investigates the interdependency between ship and terminal owner choices for systems and establishes the overall most economical solution. Cold ironing was reviewed to identify existing systems and solutions and analyse the tanker fleet and terminals. The insights were combined in an integrated economic model consisting of two sub-models; one relating terminal decisions to a cold ironing price and one establishing the vessel side costs and savings. By using fuel price as an input and acceptance rates (for both terminals and vessels) for cold ironing systems as key variables to determine. The models have been used to identify the potential of cold ironing for shortsea and parcel tankers against different fuel prices and % of fleet and terminals that have shore power equipment. In all cases, shore power was not economical, which was caused by the high costs of the fixed costs of electricity, due to the high powers required. Interesting avenues for further research would be to increase the individuality of the model using e.g. an agent based model. Also extending the model with a battery pack on the terminal to allow for peak-shaving could lead to much lower costs and higher economic potential.

Research on Efficient Preparation of Ethanol and C4 Olefins Based on Polynomial Regression and Two-Way ANOVA

C4 olefins and ethanol are essential chemical raw materials, and efficiently preparing them is a valuable topic. In this paper, in order to explore the influence of different catalyst combinations and temperatures on ethanol conversion and C4 olefin selectivity, firstly, for each catalyst combination, by observing the scatter diagram of ethanol conversion, C4 olefin selectivity and temperature, a polynomial regression model of no more than three times was established. Then, 42 regression equations corresponding to 21 catalyst groups were obtained. Twenty-one kinds of catalyst combinations were grouped by controlling variables. After grouping, the relationship between a single factor and temperature was discussed. Non-interactive two-way ANOVA judged the significance of a single factor, and the control variables among different groups were compared to determine the strong significant factors of ethanol conversion rate and C4 olefin selectivity. For judging the significance of temperature, the input rate of ethanol is ignored based on grouping, and the same catalyst combination is regarded as a repeated test. By single factor analysis, it is finally found that the temperature has higher significance to ethanol conversion rate and 400℃, while the selectivity to C4 olefins is much lower.

Palladium Recovery from Aqueous Solution By Electrodialysis

In this work, we investigate the potential of Electrodialysis to increase the palladium concentration stage in Pd recycling to ensure a maximum recovery rate. We further explore and discuss optimization of Electrodialysis process design.PGMs are in high global demand, driven mainly by their use in autocatalysts. However, the European Commission classifies PGMs as Critical Raw Materials, and the primary production of PGMs is covered to a large extent by South Africa and Russia (ca. 85%). As a result, the PGM market is in continuous deficit. Furthermore, the recycling input rate of End-of-life products containing PGMs is estimated at 21% in Europe, which is largely insufficient to meet the EU demand. At the same time, recovery rates are low, and significant amounts of metals are lost in bi-products and residuals.Palladium containing End-of-life products are typically leached in aqua regia (hydrochloric and nitric acid) before elemental separation. The separation methods are chemical intensive and do not allow for a 100 % recovery rate. However, with Pd being a critical raw material, recovering even very dilute concentrations is relevant.We investigate the potential of Electrodialysis to increase the palladium concentration stage in industrial draw solution after the chemical separation of PGMs. The only consumable required by the process is electricity. We evaluate the viability of the process and investigate the most beneficial process conditions that ensure the highest recovery rate and energy efficiency.In Electrodialysis, anion and cations-exchange membranes are stacked alternatingly between two electrodes. When a current is drawn, the cations will move towards the cathode, passing the cation-exchange membrane and vice versa for the anions. Since the membranes are selective for either anions or cations, they strongly retard the passage of the opposite ion. Therefore, cations and anions are accumulated in every second compartment, while every other chamber is desalinated.In Electrodialysis, the current density is proportional to the sum of the ion fluxes and their charges. Due to boundary layer effects at the membrane surfaces causing depletion of ions, the resistance, and specific power consumption will increase with increasing current density. We investigate the optimal operating current for an industrial mixed-ion solution containing dilute concentrations of Pd (~1200 mg/L) by doing amperodynamic sweeps and recording current-voltage curves. We then test the desalination performance of the ED stack with two different commercially available anion-/cation-exchange membrane pairs. Membrane properties are a crucial factor for ED performance. To increase the concentration stage of a target ion (Pd), the ability of the membrane to exclude water from transporting through it is of paramount importance. Therefore, we compare two types of membranes with different hydrophobicity and discuss the influence of water transport on ion permselectivity. The ion permselectivity of the ED stack is evaluated based on irreversible thermodynamics, taking into account the transport numbers for ions and water. Mass transport of ions and water will depend both on membrane properties and process design.The flow rate and the applied current density are the dominant performance parameters concerning the process design. The flow velocity is limited by the pressure drop through the electrochemical cell, while the current density determines the energy efficiency to a large extent. Therefore, we vary those two parameters to investigate their effect on the system performance.Within three hours of Electrodialysis, we increased the Pd concentration in an industrial multi-component solution by more than 60 %. However, the decrease on the desalinated side was higher than the increase on the concentrated side, suggesting that some Pd is stuck in the membrane. We conclude that ED is a promising technology for Palladium recovery, justifying large room for future research and development of membranes and operational design.