Trapping Rate Research Articles

Underground hydrogen storage: A recovery prediction using pore network modeling and machine learning

Understanding the hydrogen-brine transport properties and the hydrogen trapping rate (i.e., ratio of residual hydrogen saturation after recovery to initial hydrogen saturation) is critical to the site selection for underground hydrogen storage (UHS). In this study, a three-dimensional pore network model (PNM) was used to simulate hydrogen-brine two phase flow in various porous media, including sandstone, carbonate, and sand packs. Surface contact angles measured from previous experiments were used to study the influence of the wettability on hydrogen transport in porous media. Many studies have investigated the impact of these factors on carbon dioxide sequestration. However, because of the difference in the thermal dynamic properties of the fluids and the purpose of UHS and carbon dioxide sequestration, it is still essential to analyze the UHS performance under the different rock and fluid properties. PNM simulations showed that a relatively larger contact angle with low water affinity was more suitable for UHS due to its low hydrogen trapping rate. Two machine learning methods, the least square fitting and the support vector machine (SVM), were developed to classify the ability of a rock to trap hydrogen and to predict hydrogen trapping rates. Hydrogen trapping rates simulated using the PNM were used as the training data in the machine learning models. The SVM classified rock samples into two groups which had high hydrogen trapping rates (>50 %) and low hydrogen trapping rates (<50 %). The machine learning results showed that rock samples with a low ratio of pore size to throat size and high pore connectivity (i.e., average number of throats connected to a given pore) were favorable for a low hydrogen trapping rate. This study illustrated that the impact of both rock surface wettability and pore structural geometry should be accounted for when evaluating a hydrogen-brine two-fluid system in porous media. This work is the first study that combined PNM simulation with machine learning to investigate the influence of rock surface wettability and pore structure features on the hydrogen trapping rate, which will provide insights into site selections and decision making in large-scale UHS projects.

Hydrated doped-BaZrO3 proton conductors studied by positron annihilation lifetime spectroscopy

The study of defect chemistry for doped BaZrO3 proton conductors is of particular interest because of defect interactions that can affect the proton conductivity of the material. Protons incorporated due to the material's hydration can be trapped by negatively charged immobile dopants, reducing proton mobility. The reduction of the proton conduction impedes the use of BaZrO3 materials in energy conversion applications at intermediate temperatures (300 °C – 600 °C). The probing of proton trapping in doped BaZrO3 is hindered by the limited availability of techniques sensitive to defect chemistries. In this work, we used positron annihilation lifetime spectroscopy (PALS) to study the defect chemistry of Y-doped and Sc-doped BaZrO3. Using a two-state positron trapping model we showed that PALS can be applied to study the defect chemistry of hydrated dense proton conductors. Positron trapping rates and lifetimes were correlated with doping levels of the materials. Probability significance t-tests were carried out for PALS parameters to verify whether there are differences/similarities for various populations: non-doped/doped, level and type of doping, high temperature, and surface effects. The results revealed that the initial doping generates a significant number of traps available for positrons. Doping with yttrium increased the positron trapping rate, while this effect was not observed with scandium. Low-temperature hydration affects specimens significantly inhibiting positron trapping at undoped BaZrO3 material and highly doped specimens. Positronium formation in rough surface layers, and highly doped specimens was detected but does not exceed 1%.

Study on Capture Efficiency of Particle Trap and Performance Improvement Method for DC GIL/GIS

Whether the metal particles in DC GIL/GIS can be effectively captured by particle traps affects its safety and stability operation. In this paper, a test platform simulation of the real structure is set up to study the influence law of the particle trap on the capture rate. The effect of the key structure parameters and shielding balls on the capture rate of the up-lift particle trap is studied, and a surface coating strategy on the particle trap is proposed to improve the trapping efficiency of the trap. The results show that increasing the length and height of the trap can improve the capture efficiency of the particle, while a too-large or too-small grid is not conducive to trap capture. With the initial lifting position of the particle away from the particle trap, the capture rate decreases. The cone-shaped structure is conducive to the particles moving toward the trap direction and the hollow structure had the trapping efficiency of the particles. The research observations also indicate that the shielding balls with cone-shaped outside and hollow inside can improve the capture rate of the particle trap by 37.2% on average. Furthermore, it is found that the surface coating of the particle trap can isolate the charge transfer when moving particles arrive, which can increase the capture rate of the particle trap by 17.2% on average. Accordingly, typical trajectories of particles captured and escaped are analyzed and discussed. This work provides a significant idea to design the particle traps and the controlling strategies of DC GIL/GIS particle pollution.

Towards the optically stimulated luminescence dating of unheated flint

Flint tools are important archaeological finds, but unheated specimens remain challenging to date. The optical luminescence properties of the microcrystalline flint differ from sedimentary quartz grains, and optically stimulated luminescence (OSL) has, therefore, only occasionally been used to date heated flint specimens. However, if OSL dating could be used on unheated samples, this should expand the number of dateable flint samples from the archaeological record. This study investigates the luminescence sensitivity to blue, green, and infrared stimulation in flints collected from four sites in eastern Denmark. While stimulations at each wavelength yielded some luminescence emissions, blue OSL provided the strongest emission, and subsequent investigations here focus on measurements using this signal. The shape of the decay curves and the photo-ionising cross-sections for the blue OSL signal components are similar between natural and irradiated OSL and are also comparable to decay curves from calibration quartz. Dose–response curves show characteristic doses of ∽400 Gy, and dose recovery tests demonstrate that a SAR protocol can recover laboratory doses. The measured laboratory fading rates are considerable, where flint slices stored for up to six weeks provide average g-values of up to 9 % per decade. Also, the flint is less thermally stable compared to calibration quartz. However, a natural OSL signal remains in Cretaceous flints (albeit at 50 % or less of laboratory saturation), showing that signal loss did not outpace the electron trapping rate. The presence of a dose-dependent, natural OSL signal and acceptable dose recovery indicate that optical dating of flint surfaces could be feasible, at least in the flints from eastern Denmark, and that flint from other regions should be investigated.

A slow positron beam study of the oxidation behaviour of 310S stainless steel and alloy 800HT exposed to supercritical water

This paper reports a variable-energy slow positron beam characterisation of the surface oxide films in 310 S stainless steel and 800HT nickel-based alloy exposed to 550 °C supercritical water for 1000–4392 h. The evolution of the oxide layer was depth-profiled using positron beam energies from 0.5 to 20 keV, which enabled a probe of up to 2 mm of the near-surface region. SEM/EDS was used as a complementary characterisation tool to support and comprehend the positron annihilation spectroscopy data. A strong dependency on the positron trapping rate and the effective positron diffusion length on the microstructure of the studied materials enabled us to identify up to three non-bulk layers, which were preliminarily attributed to different oxide layers and Fe/Cr depletion regions. By calculating the effective positron diffusion length in the given multi-layer systems, we obtained the thicknesses of individual layers, which are in good agreement with the EDS analysis.

Black-bellied pangolin Phataginus tetradactyla documented in Deng Deng National Park, Cameroon, using camera traps

AbstractInformation on pangolin life history and ecology is becoming increasingly available in African countries through community-based surveys and camera-trapping. However, there is a paucity of information on the largely arboreal black-bellied pangolin Phataginus tetradactyla, which is categorized as Vulnerable on the IUCN Red List. By targeting fallen trees or logs with camera traps we recorded the black-bellied pangolin opportunistically in Deng Deng National Park (East Region, Cameroon), a locality within the presumed distribution of the species within Cameroon. We obtained a low trapping rate of 0.063 events per 100 trap-days and the capture probability was one event recorded over 1,571 trap-days (0.0006 captures per day). Deploying camera traps that focus on fallen trees or logs could be explored as a method for detecting black-bellied pangolins.

Estimating mosquito abundance and population suppression in an incompatible insect technique study

Abstract Aedes aegypti (L.) is an invasive mosquito responsible for vectoring diseases such as dengue, Zika and Chikungunya. Dengue affects a large proportion of the global population, with the World Health Organization estimating that half the global population is at risk, with 390 million infections occurring each year. Control of mosquito vector populations over large geographical scales can be improved and made economically viable by computer models with potential to aid decision support. We introduce a method for estimating mosquito abundance (population size) over time in biocontrol programmes that involve the release of sterilised insects. We employ Bayesian state‐space modelling to provide insight into population trajectories using data from an application of incompatible insect technique (IIT) biological control, in Far North Queensland, Australia. The general approach could be adapted to other insect species. We demonstrate how the modelling approach can estimate trajectories of abundance over time as an unmarked–release–recapture analysis. Additionally, it provides a means for quantifying population suppression in IIT programmes (a statistic that can be challenging to estimate in practice) using counterfactuals. Modelling results show that estimated population trajectories exhibit similar temporal patterns to raw trapping rate data collected in the field, for example, the presence of peaks (and troughs) associated with the timing of rainfall events. Additional confidence in our model was demonstrated through a cross‐validation study where we left out each of the six landscapes from our dataset, fit the model using the remaining five regions and assessed its predictive skill. Modelled counterfactuals allowed us to estimate that population suppression in treated landscapes was 95%–99%. Synthesis and applications. Our model can provide valuable insights that can shape decision support systems in sterile insect technique and incompatible insect technique programmes operating over large geographical scales. The model helps determine how many sterile/incompatible insects should be released over time and how population control is progressing (via use of counterfactual scenarios). These outcomes are achieved because the model provides estimates of wild‐type populations over time, even when there has been no differentiation between sterile/incompatible and wild‐type insects caught in traps.

Tethered-flight performance of thermally-acclimated pest fruit flies (Diptera: Tephritidae) suggests that heat waves may promote the spread of Bactrocera species.

Thermal history may induce phenotypic plasticity in traits that affect performance and fitness. One type of plastic response triggered by thermal history is acclimation. Because flight is linked to movement in the landscape, trapping and detection rates, and underpins the success of pest management tactics, it is particularly important to understand how thermal history may affect pest insect flight performance. We investigated the tethered-flight performance of Ceratitis capitata, Bactrocera dorsalis and Bactrocera zonata (Diptera: Tephritidae), acclimated for 48 h at 20, 25 or 30 °C and tested at 25 °C. We recorded the total distance, average speed, number of flight events and time spent flying during 2-h tests. We also characterized morphometric traits (body mass, wing shape and wing loading) that can affect flight performance. The main factor affecting most flight traits was body mass. The heaviest species, B. dorsalis, flew further, was faster and stopped less often in comparison with the two other species. Bactrocera species exhibited faster and longer flight when compared with C. capitata, which may be associated with the shape of their wings. Moreover, thermal acclimation had sex- and species-specific effects on flight performance. Flies acclimated at 20 °C stopped more often, spent less time flying and, ultimately, covered shorter distances. Flight performance of B. dorsalis is greater than that of B. zonata and C. capitata. The effects of thermal acclimation are species-specific. Warmer acclimation temperatures may allow pest fruit flies to disperse further and faster. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Size distribution of clusters and nucleation preference of trimers during SiC (0001) surface epitaxial growth under low coverage

In order to better understand the microscopic nucleation behavior during the epitaxial growth of a SiC crystal, a lattice kinetic Monte Carlo model is developed, in which Si and C particles are set as the basic elements. The events list is built up to implement group search and binary search, which can improve the efficiency of the algorithm. In addition, the Hoshen–Kopelman algorithm is also used to calculate the statistics of the properties of clusters. Then, the cluster size distribution function and the nucleation preference of trimers are analyzed. The results show that the cluster size distribution function obeys the Gauss distribution, and the proportion of crystal nuclei close to the average size gradually increases. Moreover, the growth temperature mainly affects the trapping rate of adatoms by dimers, and the C/Si ratio affects the formation of different types of dimers and the concentration of adatoms.

Predicting the reaction rates between flavonoids and methylglyoxal by combining molecular properties and machine learning

The kinetics of the reaction between methylglyoxal (MGO) and epigallocatechin gallate have been investigated at pH 7.4 and 37 °C, and the kinetic data were combined with previously obtained data of six other flavonoids to develop a model that allows to predict the trapping capacity of MGO based on the molecular properties of the seven flavonoids. The observed data were augmented by using synthetic minority oversampling technique forming a new data set that was used to create the predicting models for the trapping rate constant of MGO by flavonoids via principal component regression (PCR) and back-propagation neural network algorithm, respectively. The PCR model based on the first six principle components was robust and accurate comparing other created models, with an associated root-mean-square error value of 8.02 × 10−7 on the testing set. This work provides quantitative structure-activity models for rapid and accurate prediction of the trapping rate constant of MGO by flavonoids.

TCAD Modeling of GaN HEMT Output Admittance Dispersion through Trap Rate Equation Green’s Functions

We present a novel and numerically efficient approach to analyse the sensitivity of AC parameters to variations of traps in GaN HEMTs. The approach exploits an in-house TCAD simulator implementing the drift-diffusion model self-consistently coupled with trap rate equations, solved in dynamic conditions with the Harmonic Balance algorithm. The capability of the model is demonstrated studying the low-frequency dispersion of a 150 nm gate-length AlGaN/GaN HEMT output admittance YDD as a function of the trap energy of Fe-induced buffer traps. The real part of YDD exhibits strong frequency dispersion and an important degradation of the output resistance at high frequency. The imaginary part is characterized by a peak at a frequency decreasing with trap energy deeper in the gap, in agreement with experimental data on similar structures. Distributed local sources show that YDD is most sensitive to trap energy variations localized in the buffer region under the gate, peaking under the unsaturated portion of channel towards the source. Trap variations affect the output admittance when localized in depth into the buffer up to a 100 nm distance from the channel.

Factors affecting yellow pan trap captures of the emerald ash borer biocontrol agents Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius galinae Belokobylskij & Strazanac (Hymenoptera: Braconidae): Implications for monitoring establishment and seasonal abundance

Yellow pan traps are frequently used to monitor establishment of hymenopteran parasitoids introduced for biological control of the invasive ash pest, emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). To evaluate and improve their efficacy as a monitoring tool, we conducted field studies during 2016–2019 in southern Michigan where the introduced hymenopteran larval parasitoids, Tetrastichus planipennisi Yang (Eulophidae) and Spathius galinae (Braconidae) Belokobylskij & Strazanac are established. Our objectives were to describe parasitoid seasonal abundance, identify host tree variables that might influence parasitoid capture numbers (i.e., number of adults captured) and capture rates (i.e., number of positive traps per collecting period), and compare parasitoid trap captures to parasitized EAB larval densities. Yellow pan trap capture numbers and rates of both species were low for most study sites and years. Captures of both parasitoid species occurred throughout the growing season and neither showed a consistent trend in seasonal abundance. Emerald ash borer infested trees with suppressed or intermediate crown classes had higher T. planipennisi capture numbers and rates than dominant or codominant crown classes. During some years, T. planipennisi capture rates increased with decreasing tree diameter at breast height (DBH) and T. planipennisi capture numbers increased with increasing numbers of epicormics sprouts on host trees. Spathius galinae captures had no significant relationship with host tree variables but low overall capture numbers, due to its more recent introduction, may have prevented detection of any relationships. Tetrastichus planipennisi adult capture numbers were positively related to previous year’s densities of T. planipennisi parasitized larvae dissected from trees. Spathius galinae capture numbers were not correlated with parasitized EAB larval densities. We discuss the relevance of our findings to improve yellow pan trap efficacy for monitoring introduced EAB larval parasitoids.

Effect of Acidic Strength of Surface Ligands on the Carrier Relaxation Dynamics of Hybrid Perovskite Nanocrystals.

Perovskite nanocrystals (PeNCs) are known for their use in numerous optoelectronic applications. Surface ligands are critical for passivating surface defects to enhance the charge transport and photoluminescence quantum yields of the PeNCs. Herein, we investigated the dual functional abilities of bulky cyclic organic ammonium cations as surface-passivating agents and charge scavengers to overcome the lability and insulating nature of conventional long-chain type oleyl amine and oleic acid ligands. Here, red-emitting hybrid PeNCs of the composition CsxFA(1-x)PbBryI(3-y) are chosen as the standard (Std) sample, where cyclohexylammonium (CHA), phenylethylammonium (PEA) and (trifuluoromethyl)benzylamonium (TFB) cations were chosen as the bifunctional surface-passivating ligands. Photoluminescence decay dynamics showed that the chosen cyclic ligands could successfully eliminate the shallow defect-mediated decay process. Further, femtosecond transient absorption spectral (TAS) studies uncovered the rapidly decaying non-radiative pathways; i.e., charge extraction (trapping) by the surface ligands. The charge extraction rates of the bulky cyclic organic ammonium cations were shown to depend on their acid dissociation constant (pKa) values and actinic excitation energies. Excitation wavelength-dependent TAS studies indicate that the exciton trapping rate is slower than the carrier trapping rate of these surface ligands.

Photoluminescence Blinking of Quantum Confined CsPbBr3 Perovskite Nanocrystals: Influence of Size

Quantum confined CsPbBr3 nanocrystals (NCs) with adjustable photoluminescence (PL) in the range of 470–500 nm are particularly desirable for applications in light-emitting diodes and many quantum technologies. Exploration of the full potential of these perovskite NCs requires an understanding of the random fluctuation of their PL at the single-particle level, commonly termed as blinking. In this work, we study the PL blinking of quantum confined single NCs of CsPbBr3 of three different sizes between 3.80 and 5.90 nm in immobilized and fluid conditions to understand the recombination pathways and dynamics of the photogenerated charge carriers. In the immobilized state, the PL intensity trajectories and PL lifetime-intensity distributions of these single NCs reveal the contributions of both Auger recombination and trapping of hot carriers to the PL fluctuation. The results suggest a higher carrier trapping rate constant for smaller NCs. The fluorescence correlation spectroscopy and fluorescence lifetime correlation spectroscopy measurements on freely diffusing NCs show a higher off-state fraction and lower per-particle brightness of the smaller NCs. It is concluded that a larger trap depth and higher probability density of the carriers at the surface in smaller NCs make the trapping process more feasible and detrapping more difficult. The results provide first information on the effect of size on PL blinking of the quantum confined CsPbBr3 NCs, and this knowledge is expected to be useful in better designing photoluminescent samples of this class for optoelectronic applications.

Research on Photoinduction-Based Technology for Trapping Asian Longhorned Beetle (Anoplophora glabripennis (Motschulsky, 1853) (Coleoptera: Cerambycidae)

Light traps play a crucial role in monitoring pest populations. However, the phototactic behavior of adult Asian longhorned beetle (ALB) remains enigmatic. To provide a theoretical foundation to select the suitable light emitting diode (LED)-based light sources used for monitoring ALB, we compared the effect of exposure time on the phototactic response rates of adults at wavelengths of 365 nm, 420 nm, 435 nm, and 515 nm, and found that the phototactic rate increased gradually when the exposure time was prolonged, but there was no significant difference between different exposure times. We evaluated the effect of diel rhythm and found the highest phototactic rate at night (0:00-2:00) under 420 nm and 435 nm illumination (74-82%). Finally, we determined the phototactic behavioral response of adults to 14 different wavelengths and found both females and males showed a preference for violet wavelengths (420 nm and 435 nm). Furthermore, the effect of the light intensity experiments showed that there were no significant differences in the trapping rate between different light intensities at 120 min exposure time. Our findings demonstrate that ALB is a positively phototactic insect, showing that 420 nm and 435 nm are the most suitable wavelengths for attracting adults.

Direct Evidence for Sulfur-Induced Deep Electron and Hole Traps in Titania and Implications for Photochemistry

Numerous studies show that sulfating titania narrows its band gap, facilitating longer-wavelength photochemistry, but there are contradictory reports on whether this improves or degrades UV photocatalysis and whether reactions proceed via electron- or hole-mediated pathways. The widely proposed role of sulfur is that it induces deep electron traps, which increase hole lifetimes. There is, however, no direct evidence for unoccupied states deep in the band gap. By contrast, transient absorption spectroscopy indicates that sulfur induces hole traps. We present experiments on sulfur-free and sulfated titania in which dissociation of hydrogen generates electrons that fill the lowest unoccupied states. The energy of these electrons relative to the conduction band minimum (CBM) was measured with diffuse reflectance spectroscopy in the infrared and UV–vis ranges. For all commercial sulfur-containing anatase materials, conversion of tridentate sulfate species into sulfur substituted on lattice sites occurred under highly oxidizing conditions above 400 °C and led to partially unoccupied states ∼2.8 eV below the CBM. We assign this deep trap state to sulfur atoms substituted on a titanium lattice site with a formal charge of S5+ in non-stoichiometric TiO2+x, based on agreement between the experiment and the predicted UV–vis spectrum of Harb, Sautet, and Raybaud, using HSE06 density functional perturbation theory. Our band structure calculations demonstrate that titanium vacancies (or excess oxygen) are necessary to create partially unoccupied states, and X-ray diffraction Rietveld analysis confirms the existence of these vacancies. The partial occupancy of these states, along with sulfur’s ability to switch oxidation states, explains their role as both electron (S5+ + e– → S4+) and hole (S5+ + h+ → S6+) traps, reconciling previous work. We discuss how relative rates of electron vs hole trapping can enhance or degrade activity depending on the pathway and the TiO2+x non-stoichiometry. We consider how increasing the dopant concentration can induce band bending or pin the Fermi level and shift the redox reactions that are thermodynamically accessible.

Intricate Reaction Pathways on CH3NH3PbI3 Photocatalysts in Aqueous Solution Unraveled by Single-Particle Spectroscopy.

Organic-inorganic hybrid perovskites such as MAPbI3 (MA+ = CH3NH3+) have emerged as promising materials for solar cells and light-emitting devices. Despite their poor stability against moisture, perovskites work as hydrogen-producing photocatalysts or photosensitizers in perovskite-saturated aqueous solutions. However, the fundamental understanding of how chemical species or support materials in the solution affect the dynamics of the photogenerated charges in perovskites is still insufficient. In this study, we investigated the photoluminescence (PL) properties of MAPbI3 nanoparticles in aqueous media at the single-particle level. A remarkable PL blinking phenomenon, along with significant decreases in the PL intensity and lifetime compared to those in ambient air, suggested temporal fluctuations in the trapping rates of photogenerated holes by chemical species (I- and H3PO2) in the solution. Moreover, electron transfer from the excited MAPbI3 to Pt-modified TiO2 proceeds in a concerted fashion for photocatalytic hydrogen evolution under the dynamic solid-solution equilibrium condition.

Boundary homogenization for patchy surfaces trapping patchy particles.

Trapping diffusive particles at surfaces is a key step in many systems in chemical and biological physics. Trapping often occurs via reactive patches on the surface and/or the particle. The theory of boundary homogenization has been used in many prior works to estimate the effective trapping rate for such a system in the case that either (i) the surface is patchy and the particle is uniformly reactive or (ii) the particle is patchy and the surface is uniformly reactive. In this paper, we estimate the trapping rate for the case that the surface and the particle are both patchy. In particular, the particle diffuses translationally and rotationally and reacts with the surface when a patch on the particle contacts a patch on the surface. We first formulate a stochastic model and derive a five-dimensional partial differential equation describing the reaction time. We then use matched asymptotic analysis to derive the effective trapping rate, assuming that the patches are roughly evenly distributed and occupy a small fraction of the surface and the particle. This trapping rate involves the electrostatic capacitance of a four-dimensional duocylinder, which we compute using a kinetic Monte Carlo algorithm. We further use Brownian local time theory to derive a simple heuristic estimate of the trapping rate and show that it is remarkably close to the asymptotic estimate. Finally, we develop a kinetic Monte Carlo algorithm to simulate the full stochastic system and then use these simulations to confirm the accuracy of our trapping rate estimates and homogenization theory.

Folic acid conjugated-chitosan modified nanostructured lipid carriers as promising carriers for delivery of Umbelliprenin to cancer cells: In vivo and in vitro

The aim of this survey was to load Umbelliprenin (UMB) on nanostructured lipid carriers (NLCs) coated with folic acid-bound chitosan and to investigate its anti-cancer effects in vitro and in vivo. The fabrication of UMB-NCF-NPs was performed using high pressure homogenization and ultra-sonication method. Subsequently, the physiochemical properties, drug entrapment and release of formulation were examined. The trapping rate of the drug was 90.8 % ​​and within 10 days, it was released slowly about 97.2 %. In vitro assays including MTT, flow cytometry, fluorescence staining, and qPCR analysis on MCF-7 cells showed that UMB-NCF-NPs were effectively able to inhibit cancer cells by activating the apoptosis mechanism under the influence of increasing of ROS is intracellular. The antioxidant and pro-oxidant potential of UMB-NCF-NPs outside and inside the cell was confirmed by assessing the extent of free radical scavenging and molecular analysis respectively. In vivo experiments on chorioallantoic membrane (CAM) and tumor-bearing mice also confirmed the anti-angiogenesis (by reducing vascular factors and reduced expression of angiogenesis genes) and anti-tumor (by ∼ 75.42 % ​​reduction in tumor volume over 19 days) effects of UMB-NCF-NPs. According to the results of in vitro and in vivo tests, this formulation can be suggested as a suitable candidate for cancer treatment studies.

Regulation effect of slit-check dam against woody debris flow: Laboratory test

Woody debris flows (i.e., debris flows carrying wood) are common in mountainous and forested areas. They can cause more severe hazards due to the effects of LW (woody debris larger than 1 m in length and 10 cm in width) compared to debris flows without LW. Mitigation structures for debris flows have considered little of the regulating effect on LW and the influence of LW on the regulation effect of sediment. Thus, model tests were conducted to discuss the regulation effects of slit-check dams on woody debris flow. Research results demonstrated that slit-check dams can effectively regulate woody debris flows without overflows. Once overflow occurs, sediment trapping efficiency and the wood retention rate dramatically decrease. The sediment trapping efficiency of slit-check dams on debris flows without LW shared a linear relationship with the relative opening width, the height-to-width ratio of the opening, and the opening density. However, this was also influenced by the wood retention rate for woody debris flow. A logarithmic relationship between the sediment trapping rate and wood retention rate was obtained. The wood retention rate is mainly determined by the ratio of the LW length to the opening width, the ratio of the LW length to the channel width and the opening density of the slit-check dam. Three draining patterns of woody debris flows at the slit-check dam and three clogging types of LW at the openings of the slit-check dam were observed. Some design criteria for the structure parameters of the slit-check dam were proposed. These research results promote a better understanding of the regulation effect of slit-check dams on woody debris flows and provide a basis for the optimal design of slit-check dams.