Redistribution Phase Research Articles

Assessing a semi-empirical model performance to predict the wetting patterns in subsurface drip irrigation

ContextBecause of the complexity of soil water distribution, accurate prediction of wetting pattern is not easily accessible and this has led to a inefficiency in some proposed models in the literature. These models do not consider the hydraulic characteristics of the irrigation system and are developed solely on the basis of the water volume or infiltration rate, soil hydrodynamic properties, and other conditions of the percolation environment. ObjectiveDue to the importance of the estimation of wetting front beneath Subsurface Drip Irrigation (SDI) laterals, a semi-empirical model using easily accessible data of the SDI system is proposed to predict the wetting patterns in both distribution and redistribution phases. The aforementioned model has been developed based on a novel approach that couples the governing equations of the lateral hydraulics with empirical equations derived by dimensional analysis. MethodsTo develop the model and evaluate its performance, three 16-mm drip line pipes with 0.2, 0.4, and 0.5 m emitter spacing, and 2–5 l/h discharge were placed at 0.20 m depth in a soil box filled with clay loam soil. Water was applied for 3 hours at 50, 100, and 150 kPa operating pressures, and the wetting patterns’ geometries were measured in each lateral after 1, 2, 3, and 24 h. The performance of the model was then assessed and compared with that of three other models. Results and conclusionThe result demonstrated that the proposed model provides the most accurate estimations of the wetting depths and widths. RMSE and MAE statistical indexes of the wetting depth were 0.001–0.002 m and 0.004–0.009 m, respectively, whereas those associated with the wetting width were 0.001–0.003 m and 0.005–0.016 m, respectively. These values resulted in the lowest error when compared with the corresponding obtained from other well-known models. Consequently, the model allows acceptable predictions of the wetting patterns using accessible hydraulic parameters of the SDI system. SignificanceUniquely, the results of the lateral hydraulic analysis were applied to determine the wetting front dimensions in this study. Also, the results demonstrated that the model was successful in wetting pattern prediction beneath the lateral as a line source. While other models usually are used to estimate the wetting front around a point source.

Carbonate morphological features of vineyard soils in a semiarid Mediterranean environment

AbstractMany vineyard soils in semiarid Mediterranean environments develop from carbonated materials and often show very diverse forms of pedogenic calcium carbonate accumulations. Based on 275 vineyard soil profiles in the Castilla La Mancha (CLM) territory (Spain), this paper presents an in‐depth comprehensive study of a large number of morphological expressions of these carbonate distributions, while exploring various pedogenesis formation hypotheses. The interactions among the calcareous nature of parent material, surface topography and climate are the factors that most affected their morphology and pedogenesis. The occurrence and distribution of carbonate features in CLM vineyard soils can be more complex than in other areas. Many accumulations are relatively ancient, which is the case of petrocalcic horizons, and in‐keeping with conservative means, which reveals the occurrence of successive carbonate accumulation cycles. More recently dissolved and precipitated seasonally pedogenic carbonates (sometimes as coatings) have appeared, which are nothing more than a simple recent redistribution of carbonates. A structural imprint is observed: pedogenic carbonates appeared much more abundantly on the lowermost horizons, which can be related to the repeated redistribution phases that occurred in different pedogenesis stages. The data provided herein help to improve the understanding of the nature of viticultural calcareous soils in semiarid Mediterranean regions.

Adaptation timescales of estuarine systems to human interventions

Many estuaries and tidal basins are strongly influenced by various human interventions (land reclamations, infrastructure development, channel deepening, dredging and disposal of sediments). Such interventions lead to a range of hydrodynamic and morphological responses (a changing channel depth, tidal amplitude and/or suspended sediment concentration). The response time of a system to interventions is determined by the processes driving this change, the size of the system, and the magnitude of the intervention. A quantitative understanding of the response time to an intervention therefore provides important insight into the processes driving the response. In this paper we develop and apply a methodology to estimate the response timescales of human interventions using available morphological and hydraulic data. Fitting an exponential decay function to data with sufficient temporal resolution yields an adaptation timescale (and equilibrium value) of the tidal range and deposited sediment volumes. The method has been applied in the Dutch Wadden Sea, where two large basins were reclaimed and where long-term and detailed bathymetric maps are available. Exponential fitting the morphological data revealed that closure of a very large part of a tidal basin in the Wadden Sea initially led to internal redistribution and import of coarse and fine sediments, and was followed by a phase of extensive redistribution while only fine-grained sediments are imported. Closure of a smaller part of a smaller basin led to shorter response timescales, and these response timescales are also more sensitive to rising mean sea levels or high waters. The method has also been applied to tidal water level observations in the Scheldt and Ems estuaries. Exponential fits to tidal data reveal that adaptation timescales are shortest at the landward limit of dredging. The adaptation time increases in the landward direction because of retrogressive erosion (Scheldt) or lowering of the hydraulic roughness (Ems). The seaward increase in adaptation time is related to the seaward widening of both systems.

Decreased Clinical Toxicity and Two-Phase Elimination Kinetics Observed After Intravenous Iron Sucrose Overdose

BackgroundManagement of oral iron overdoses is well-established, but there is limited literature regarding intravenous iron sucrose overdoses. Indications for administering deferoxamine after oral iron overdoses include clinical signs and symptoms of toxicity, along with a serum iron concentration ≥ 500 μg/dL. Reported signs and symptoms of iron sucrose overdose do not appear to correlate with those of oral iron overdoses. Case ReportWe present a case of intravenous iron sucrose overdose in a clinically well-appearing patient with a presenting serum iron concentration that was several times higher than the usual threshold concentration for initiating deferoxamine treatment. A 21-year-old woman presented to the emergency department after an accidental intravenous iron sucrose overdose. The patient received a home infusion of 1000 mg iron sucrose, which was five times the prescribed dose. Her presenting serum iron concentration was 1799 μg/dL, with bicarbonate and anion gap both within normal limits and an unremarkable physical examination. Because she did not have evidence of severe iron toxicity, she was treated supportively and deferoxamine was not administered. Her serum iron concentration decreased below the toxic range over the next 14 h, and she was discharged home the next day. Why Should an Emergency Physician Be Aware of This?This patient was managed successfully with expectant care alone, suggesting that iron sucrose overdose has much lower toxicity than oral iron salt overdose. This discrepancy between measured iron concentrations and clinical presentation may be explained by the elimination kinetics of iron sucrose having separate redistribution and elimination phases.

A Highly Integrated Tri-Path Hybrid Buck Converter With Reduced Inductor Current and Self-Balanced Flying Capacitor Voltage

This paper presents a single-stage tri-path buck converter with reduced inductor current and self-balanced flying capacitor voltage. The proposed converter introduces capacitor paths to reduce the average inductor current and inductor current ripple, hence decreasing the conduction loss. Operating with two states per conversion cycle, it exhibits a relatively low voltage conversion ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${D}$ </tex-math></inline-formula> /(1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$+\,\,2{D}$ </tex-math></inline-formula> ). Besides, it realizes a self-balanced flying capacitor voltage in the charge redistribution phase. Similar to the conventional buck converter, the proposed converter in continuous-current mode only has two complex poles. Therefore, we design a Type-III compensator to obtain a good transient response. Moreover, the circuit does not require extra supplies for gate drivers due to the reutilization of the flying capacitor voltages, eliminating additional circuit and power overheads. The proposed converter, validated in a 65-nm standard CMOS technology, regulates a 0.7 V – 1 V output voltage from a 3.3 V – 4 V input voltage, delivering a maximum output power of 270 mW. The peak efficiency is 84%, with a switching frequency up to 5 MHz.

An efficient verifiable secret redistribution scheme

A verifiable secret redistribution (VSR) scheme is a verifiable secret sharing scheme in which the shareholders can redistribute the secret from an old (t,n)-threshold access structure to a new (t′,n′)-threshold access structure without reconstructing the secret and without interacting with the dealer. There exists an important flaw in the previous VSR schemes which has not been addressed by now: During redistributing the secret from an old (t,n)-threshold access structure to a new (t′,n′)-threshold access structure, nt−n−t+1t restarts of the secret redistribution phase, in the worst case, are required to eliminate faulty shareholders and complete the secret redistribution phase. In this paper, we propose a new VSR scheme using Homogeneous linear recursions (HLR) and prove its security. Our scheme has the following interesting properties: First, it addresses the mentioned flaw of the previous VSR schemes without relaxing the security. Second, it does not have any restart and is more efficient than the previous VSR schemes. Finally, without observing the produced shares and sub-shares, the honesty of the dealer and shareholders can be verified publicly.

Targeted design of a recombinant tracer for SPECT renal imaging.

Rationale: A robust radiopharmaceutical has high uptake in the target and low retention in non-target tissues. However, traditional tracers for renal imaging that chemically chelate 99mTc are excreted through the renal route with transient resident time in the kidney. Following a rational design approach, we constructed a protein-based radiotracer, designated PBT-Fc, to sequentially bind tubular neonatal Fc-receptor and subsequently proximal tubular basement membrane for its targeted sequestration in kidney parenchyma. In this process, the tracer participates in physiologic glomerular filtration and tubular reabsorption while escaping lysosomal catabolism and urinary clearance.Methods: To specifically target renal receptors in navigating the urinary passage in the kidney, we produced a recombinant fusion protein with two separate functional parts: a polybasic PBT segment derived from human Vascular Endothelial Growth Factor and Fc segment of IgG1. The chimeric fusion of PBT-Fc was labeled with radionuclide 99mTc and tested in rodent models of kidney diseases. Planar scintigraphy and single-photon emission computerized tomography (SPECT) were performed to evaluate renal-specificity of the tracer.Results: When injected in mouse and rat, following a brief 10 - 15 min dynamic redistribution phase in circulation, ~ 95% of the [99mTc]-PBT-Fc signal was concentrated in the kidney and lasted for hours without urinary loss or surrounding tissue activities. Long-lasting tracer signals in the kidney cortex in conjunction with SPECT greatly augmented the image quality in detecting pathological lesions in a variety of disease models, including ischemic acute kidney injury, drug-induced renal toxicity, and chronic kidney disease from renin-angiotensin system (RAS) overactivation.Conclusion: Exclusive renal retention of the recombinant radiotracer greatly facilitated static-phase signal acquisition by SPECT and achieved submillimeter spatial resolution of kidney alternations in glomerular and tubular disease models.

Time- and Site-Dependent Postmortem Redistribution of Antidepressants and Neuroleptics in Blood and Alternative Matrices.

Postmortem redistribution (PMR) leads to challenges in postmortem case interpretation. Particularly antidepressants and neuroleptics are expected to undergo PMR based on their physico-chemical properties. For the current study, time- and site-dependent PMR of 20 antidepressants and neuroleptics were investigated in humans (authentic cases); five of which are discussed in detail (citalopram, mirtazapine, quetiapine, risperidone and venlafaxine) along with two metabolites (9-OH-risperidone and O-desmethylvenlafaxine). Blood [femoral (pB) and heart blood (HB)] and tissue biopsy samples (lung, kidney, liver, spleen, thigh muscle and adipose tissue) were collected upon admission to the institute utilizing a computed tomography-guided sample collection workflow (t1). Approximately 24h later (t2; mean 23±9.3h), samples from the same body regions were collected manually. Liquid chromatography-tandem mass spectrometry was used for quantification. Most antidepressants and neuroleptics showed significant time-dependent concentration changes indicating the occurrence of PMR. For the first time, two phases of redistribution in pB for quetiapine were proposed (concentration decreases in the early postmortem phase, followed by concentration increases) and contrasting existing literature, both concentration increases and decreases in pB overtime were observed for risperidone and 9-OH-risperidone. Venlafaxine and its metabolite only showed minimal concentration changes, while citalopram exhibited a trend for concentration increases and mirtazapine for concentration decreases in pB overtime. Based on time-dependent tissue data, passive diffusion processes along the muscle-to-pB, liver-to-HB and lung-to-HB concentration gradients could be proposed along with bacterial degradation. Overall, no case interpretation had to be adjusted, which suggests that PMR changes of antidepressants and neuroleptics do not seem to be relevant for forensic case interpretation within the 24h period that was investigated. However, limitations of the current study (e.g., temperature-controlled storage of the bodies) could have led to an underestimation of occurring postmortem changes, hence, interpretation of postmortem results should always be conducted with care, considering PMR phenomena and inter-individual variability.

Numerical analysis and optimization of triggered furrow irrigation system

Numerical methods have been proved to be useful tools for understanding different phenomena. In this paper, triggered furrow irrigation has been analyzed by means of numerical modeling. To this end, a special code is developed for simulation of triggered furrow irrigation system by coupling three-dimensional Richards’ equation and one-dimensional fully hydrodynamic form of Saint-Venant equations. The coordinate transformation technique was used for solving Richards’ equation that improves flexibility of model for simulation of water flow in irregularly shaped furrows. Furthermore, overland flow module benefits from high-resolution total variation diminishing scheme that avoids artificial oscillations commonly occurring on the advance water front. The code was validated against different analytical, numerical and experimental benchmarks. In all cases, the accuracy of model was acceptable. The code was subsequently employed to simulate all phases of triggered furrow irrigation system (including advance and redistribution phases) on a field cultivated with wheat. Finally, Taguchi technique was employed to deduct proposals to optimize performance of triggered furrow irrigation system in terms of sensor position, triggering and cutoff thresholds and inflow rate. It was concluded that optimal performance of triggered irrigation system was obtained when the water content sensor was installed close to the furrow, providing that triggering and cutoff thresholds were set as − 15 and − 3 m (close to field capacity) and inflow rate was 1 L s−1.

The world-class Nanling metallogenic belt (Jiangxi, China): W and Sn deposition at 160 Ma followed by 30 m.y. of hydrothermal metal redistribution

The W-Sn Maoping deposit and related W-Sn deposits from the world-class Nanling Range in Southeast China formed at ca. 160 Ma and experienced several phases of metal addition and metal redistribution between 160 and 130 Ma. Isotopic dating of ore mineral (wolframite) of Maoping demonstrates that W was deposited first, during a hydrothermal event at ca. 160 Ma. Successive fluid episodes, at ca. 156 Ma (Mo and Sn-rich fluid) and 152 Ma (REE-rich fluid), resulted in the formation of REE- and Fe-Cu-Zn-sulfide minerals. A last fluid event occurring at ca. 130 Ma was responsible for the deposition of Zr-REE-Nb-Ta minerals that are attributed to magmatic fluids derived from unexposed magmatic bodies. The three episodes of fluid circulation post-dating W deposition resulted in partial to complete resetting of the isotopic systems (mica, wolframite, xenotime), which are conventionally used for dating such deposits. We show that W and Sn mineralization in the Nanling Range formed during a unique fluid event at ca. 160 Ma. Later fluid episodes redistributed the previously deposited metals and sequentially introduced additional metals, including Mo-Sn, Fe-Cu-Zn, and Zr-REE-Nb-Ta. Direct dating of paragenetically well-constrained minerals is therefore critical for determining the age and the duration of mineralizing processes and for characterizing the fluid evolution of magmatic-hydrothermal systems, as exemplified in the Nanling Range.

Wetting Pattern for A Two-Line Trickle Source

The laboratory tests carried out 12 tests to follow the advance of wetting front at appropriate times during the wetting and redistribution phases as a resulting of water application from a single linear trickle source or two linear trickle sources with a certain spacing to soil profile. These data are used to express with an estimating relationships for the wetting pattern produced by single linear trickle source and two linear trickle sources during wetting and redistribution phases. The study showed that there is a significant correspond between the wetting pattern of the measured and the estimated by the experimental equations. The wetting pattern increases with the decreasing of spacing between the two linear trickle sources, and this increase is regular along the wetting front or the surrounding of the wetting pattern, and this increase in the vertical direction of the wetting pattern is more in sandy loam soil than in silty clay soil and vice versa in the horizontal direction, when compare among the wetting patterns at the end of the wetting phase and the redistribution phase at a total time of 72 hours.

Amitriptyline accumulation in tissues after coated activated charcoal hemoperfusion-a randomized controlled animal poisoning model.

Amitriptyline poisoning (AT) is a common poisoning, and AT possess the ability to promote life-threatening complications by its main action on the central nervous and cardiovascular systems. The pharmacokinetic properties might be altered at toxic levels compared to therapeutic levels. The effect of coated activated charcoal hemoperfusion (CAC-HP) on the accumulation of AT and its active metabolite nortriptyline (NT) in various tissues was studied in a non-blinded randomized controlled animal trial including 14 female Danish Land Race piglets. All piglets were poisoned with amitriptyline 7.5mg/kg infused in 20min, followed by orally instilled activated charcoal at 30min after infusion cessation. The intervention group received 4h of CAC-HP followed by a 1-h redistribution phase. At study cessation, the piglets were euthanized, and within 20min, vitreous fluid, liver tissue, ventricle and septum of the heart, diaphragm and lipoic and brain tissues were collected. AT and NT tissue concentrations were quantified by UHPLC-MS/MS. A 4-h treatment with CAC-HP did not affect the tissue accumulation of AT in the selected organs when tested by Mann-Whitney U test (p values between 0.44 and 0.73). For NT concentrations, p values were between 0.13 and 1.00. Although not significant, an interesting finding was that data showed a tendency of increased tissue accumulation of AT and NT in the CAC-HP group compared with the control group. Coated activated charcoal hemoperfusion does not significantly alter the tissue concentration of AT and NT in the AT-poisoned piglet.

Redistribution for cost minimization in disaster management under uncertainty with trapezoidal neutrosophic number

The activity of humanitarian logistic is urgently employed in the aftermath of the disaster. The sudden shock of disaster emerges high demand in the society. In this context, this research has introduced a mathematical model for humanitarian logistic applying the fact of redistribution of resources. The model aims to minimize the total cost of whole operation and the total time for redistribution phase so as to response the emergency situation quickly. According to the model distribution of humanitarian items to the affected areas are commenced by a governing authority in the first phase. The phase of redistribution is started after a certain period of time when some areas get relief and some are still unable to recover their vulnerable condition after the disaster. The concept of redistribution, established in the logistic model is beneficial for better response in the emergency condition as it quickly redistributed the resources from the areas which are recovered to the areas still being affected. The performance of the model is analyzed with some numerical data considering the uncertain parameter in the form of a trapezoidal Neutrosophic number. The model is solved through three different techniques: Neutrosophic programming approach, goal programming, and Pareto optimal solution approach. Moreover, a comparative analysis is performed in this study among the results obtained by three different techniques which are useful for the decision maker to make a practical decision in emergency response.

Computational evaluations of HYDRUS simulations of drip irrigation in 2D and 3D domains (i-Surface drippers)

HYDRUS is a popular package for simulating water and solutes movement in variably-saturated porous media. It is widely used by designers of drip irrigation systems to simulate the active wetting pattern. However, there are many design parameters of the domain and for the flux calculation; other than the acceptable simulations, some configurations might cause under-estimation or over-estimation of the wetting pattern. Comparative assessments of the surface drip simulation parameters were performed. We evaluated the effect of different domain geometries, element shapes, coordinate systems, emitter discharges, and soil textures on the accuracy and stability of the simulation. The results showed that the 3D simulations are more successful and reliable than the 2D simulations in terms of mass balance error. For the 2D domains, the error increases as the texture goes finer, and for axisymmetric domains than the Cartesian ones. We found a relationship between the flux and the soil hydraulic conductivity that their quotient should not exceed 1.8 and 3.2 for axisymmetric and cartesian coordinates. Our outcomes show that the infiltration stage took more time than the redistribution stage because of the variation in water content that delays the convergence at infiltration.Additionally, we found that the range between the saturated and the residual water content of the soil causes instability of the simulation as it gets higher. The differences between 2D simulations and the equivalent 3D slices were highly dependent on the soil texture, the heavier the larger; and dependent on the simulation phase, where the redistribution phase has fewer differences than the infiltration phase. Finally, we have determined the best matching 2D flux profile to each 3D profile and revealed the source of variation between 2D and 3D profiles where it was mostly-affected by the emitter’s location, the soil texture, and simulation phase. In part 2 of this paper, we expanded the study for subsurface drip simulations and showed the difference between the two systems’ designs.

Stress redistribution of simply supported reinforced concrete beams under fire conditions

This study presents experimental and numerical investigations of simply supported steel reinforced concrete (RC) beams under fire. The temperature field of cross sections, the vertical deflection at mid-span, and specifically the axial expansion displacement at beam-ends were measured during the fire tests. A novel finite element (FE) model of a RC beam under fire was developed, in which the water loss in the heat transfer analysis and the concrete transient strain in the mechanical analysis were considered. Based on the validated FE model proposed in this study, parametric studies were conducted to investigate the effects of the beam type, the protective layer thickness, and the load ratio on the thermal and mechanical behavior of simply supported RC beams. It was found that greater fire resistance and fire performance of girder beams in comparison to secondary beams contributed to the non-structural reinforcements, which effectively compensated for the reduced tensile capacities of structural reinforcements because of the degradation of the material properties. In addition, the history of normal stress distributions of concrete under fire can be divided into three phases: expansion, stress redistribution and plateau phases.

3DMGAR: A Transient Quasi‐3D Point‐Source Green–Ampt Infiltration and Redistribution Model

Core Ideas Good design of point‐source irrigation systems needs simplified quasi‐spherical wetting models. Efficient irrigation with minimal impact, requires robust estimates of infiltration and redistribution. 3DMGAR is based on robust Green–Ampt infiltration and redistribution concepts for irrigation series. 3DMGAR tested favorably with benchmark 2D Richards simulations for a wide range of soils. Provided 3DMGAR source code is easy to apply and parameterize with readily available information. Although Richards' equation (RE) generally provides a good description of infiltration and water redistribution in soils, its numerical solutions can be computationally intensive or suffer from numerical instability and require extensive soil data. Simplified physically based approaches are often used in many practical settings after validation against RE used as a benchmark. The purpose of this research was to develop and test an approximated physical model for simulating transient point‐source infiltration and redistribution in a quasi three‐dimensional flow domain. An existing three‐dimensional Green–Ampt model that simulates only the infiltration phase is extended based on the one‐dimensional modified Green–Ampt with redistribution (MGAR) method to calculate the three‐dimensional soil water redistribution phase between point‐source events. Comparison with the HYDRUS‐2D numerical solution of RE showed the proposed model (3DMGAR) to provide satisfactory results for a broad range of soils. The ability of 3DMGAR to accurately and robustly simulate infiltration and redistribution for point‐source water application time series is particularly important for cases with difficult Richards solutions, such as in sandy soils, to improve water application efficiency and decrease chemical leaching in many settings like crop fertigation, waste water disposal, and mitigation of climate‐induced coastal salinization.

Disposition, Metabolism and Histone Deacetylase and Acetyltransferase Inhibition Activity of Tetrahydrocurcumin and Other Curcuminoids

Tetrahydrocurcumin (THC), curcumin and calebin-A are curcuminoids found in turmeric (Curcuma longa). Curcuminoids have been established to have a variety of pharmacological activities and are used as natural health supplements. The purpose of this study was to identify the metabolism, excretion, antioxidant, anti-inflammatory and anticancer properties of these curcuminoids and to determine disposition of THC in rats after oral administration. We developed a UHPLC–MS/MS assay for THC in rat serum and urine. THC shows multiple redistribution phases with corresponding increases in urinary excretion rate. In-vitro antioxidant activity, histone deacetylase (HDAC) activity, histone acetyltransferase (HAT) activity and anti-inflammatory inhibitory activity were examined using commercial assay kits. Anticancer activity was determined in Sup-T1 lymphoma cells. Our results indicate THC was poorly absorbed after oral administration and primarily excreted via non-renal routes. All curcuminoids exhibited multiple pharmacological effects in vitro, including potent antioxidant activity as well as inhibition of CYP2C9, CYP3A4 and lipoxygenase activity without affecting the release of TNF-α. Unlike curcumin and calebin-A, THC did not inhibit HDAC1 and PCAF and displayed a weaker growth inhibition activity against Sup-T1 cells. We show evidence for the first time that curcumin and calebin-A inhibit HAT and PCAF, possibly through a Michael-addition mechanism.

Comparative Analysis of Steady-State Models for a Switched Capacitor Converter

A recently reported modeling methods for a switched capacitor converter either assume output as “firm” voltage or a resistor to facilitate calculation. When the size of output filter capacitor is moderate, accompanied by noticeable output ripple, previous modeling results may not provide accurate prediction and design guidelines. In this paper, a new modeling technique taking into account the output capacitor effect is proposed for simple dual-phase switched capacitor converters without complex coupling loops. The proposed model employs transient calculation, takes charge redistribution phase into account, and includes the duty cycle, switching frequency as well as output capacitor simultaneously in the final output impedance formula, which enhances accuracy of the model. It is suitable for interleaved and noninterleaved switched capacitor converters. The simulation and experimental results for the unity gain SC converter are provided to verify the proposed theory.

Radiocaesium partitioning in Japanese cedar forests following the "early" phase of Fukushima fallout redistribution.

Our study focused on radiocaesium (137Cs) partitioning in forests, three vegetation periods after the Fukushima Daiichi nuclear power plant accident. 137Cs distribution in forest components (organic and mineral soil layers as well as tree compartments: stem, bark, needles, branches and roots) was measured for two Japanese cedar stand ages (17 and 33 years old). The results showed that around 85% of the initial deposit was found in the forest floor and topsoil. For the youngest stand almost 70% of the deposit is present in the forest floor, whereas for the oldest stand 50% is present in the 0–3 cm mineral soil layer. For trees, old and perennial organs (including dead and living needles and branches, litter fall and outer bark) directly exposed to the fallout remained the most contaminated. The crown concentrated 61–69% of the total tree contamination. Surprisingly the dead organs concentrated 25 ± 9% (young cedars) to 36 ± 20% (mature cedar) of the trees’ residual activity, highlighting the importance of that specific compartment in the early post-accident phase for Japanese cedar forests. Although the stem (including bark) represents the highest biomass pool, it only concentrates 3.3% and 4.6% of the initial 137Cs deposit for mature and young cedars, respectively.

Soil water movement under a drip irrigation double-point source

Particularly in dry regions, the scarcity of high-quality fresh water has heightened the importance of urban runoff water re-use, leading as well to the improvement of water use efficiency through the surface drip irrigation method. Given the limited research on wetting front migration under a surface drip irrigation emitter, soil water movement under a double-point-source irrigation emitter was investigated. An experimental soil bin was designed and filled with silt loam soil, and time domain reflectometry and tensiometers were used to measure soil moisture contents and soil water potential, respectively. The results show that under the conditions of 6 hours of irrigation with two drippers each delivering 1.05 L hr−1 and spaced at 45 cm, the soil moisture content of the 0–30 cm layer increased rapidly and reached 0.29 cm3 cm−3, and was greater than that in the 30–60 cm layer as irrigation proceeded. After 6 hours the irrigation was stopped, such that in the redistribution phase, soil moisture of the top layer gradually decreased, while that of the sublayer gradually increased. The results indicate that 6 hours of irrigation under given emitter flow conditions produced adequate soil moisture down to 30 cm for most shallow-rooted crops.