Occurrence Of Peak Research Articles

Analysis of a second peak of electron density observed in high-power impulse magnetron sputtering plasma using a Langmuir probe

Plasma characteristics of a high-power impulse magnetron sputtering (HIPIMS) for copper deposition were investigated using a time-resolved Langmuir probe to explore HIPIMS discharge physics. Various discharge frequencies and pulse widths were employed while operating the HIPIMS in a constant current mode. Waveforms of the HIPIMS cathode current remained constant throughout the HIPIMS voltage pulse. It was found that electrons exhibited a bi-Maxwellian energy distribution both during and after the HIPIMS pulse. After the HIPIMS pulse, plasma density built up to a second peak while the bulk electron temperature quickly decreased. By examining the effect of pulse width and discharge frequency on the temperature of hot electrons through Langmuir I–V curves, it is suggested that the hot electron ionization contributed to the occurrence of the second peak.

Characterizing extreme drought and wetness in Guangdong, China using global navigation satellite system and precipitation data

As global temperature rises, the frequency of extreme climate events, e.g., severe droughts and floods, has increased significantly and caused severe damage over the past years. To this regard, precipitation efficiency, a crucial meteorological parameter, could provide valuable insights for a better understanding of the patterns and characteristics of these extreme events. In this study, taking Guangdong province as an exemplary region, we first obtained long-term and high-resolution historical records of precipitation efficiency by integrating the observations from a dense network of Global Navigation Satellite System (GNSS) stations with precipitation data, and then characterized the extreme drought and wetness through climate indices. We found a distinct seasonal trend in precipitation efficiency in Guangdong, with annual fluctuations ranging from 10 to 25%. Notably, precipitation efficiency is higher in proximity to the Pearl River Delta Plain and gradually decreases towards the east and west. The occurrence of anomalous peaks and valleys in precipitation efficiency generally corresponds to dry and wet conditions, respectively. A total of 9 extreme wet events and 6 dry events occurred from January 2007 to May 2022, with durations from 3 to 6 months. Our results also demonstrated that both wet and dry frequencies exhibit an increasing trend with the expansion of the time scale, and the frequency of extreme events near the Pearl River Delta Plain surpasses that of other regions. Furthermore, the propagation time from meteorological anomalies to agricultural and hydrological anomalies is about 3 months. The periodic characteristics of meteorological anomalies are identified as the primary driver for other anomalous periodic patterns. Our work unveils the long-term dynamic behavior of precipitation efficiency, as well as the characteristics of extreme drought and wetness events in the regions characterized by intricate land–atmosphere interactions.

Truck Emission Forecasting and Peak Mitigation in a Port Terminal

The objective of this work is to predict the emissions generated by trucks upon their arrival at a port terminal. This prediction is based on a forecast model that predicts truck arrivals, serving as a key input for the proposed methodology. By using the curve of truck arrivals within specific time intervals, an emission model is adopted to estimate the corresponding pollutant emissions. Then, a redistribution algorithm is designed to optimize the scheduling of truck arrivals, effectively mitigating the occurrence of possible peaks in emissions. The algorithm, which takes into account constraints about the truck operations inside the terminal, operates by redistributing the arrival patterns of trucks in a smooth way in order to also consider the truck operators’ reluctance to change the existing schedule. The case study of export flows in the PSA Genova Pra’ (PSA GP) terminal is addressed in the paper.

Structural, morphological, optical and antibacterial performances of rare earth (Sm)-doped ZnO nanorods

The significant rise of ultra-violet (UV) radiation and pathogenic infectious bacteria poses a serious threat to global health. Numerous researchers’ interests are attracted by novel materials with strong UV-blocking ability, antibacterial activity and low toxicity to other species. In this case, a simple wet chemical method with different annealing temperatures (400, 500, and 600 °C) was employed to create highly effective rare earth (Sm)-doped ZnO nanorods. The (101) plane of wurtzite ZnO shifts towards a lower angle with increasing annealing temperature, according to the X-ray diffraction (XRD) study findings, which additionally establishes the consequence of lattice expansion. Occurrence of doublet peaks of Sm 3d (Sm 3d5/2 and Sm 3d3/2) in the X-ray photoelectron spectroscopy (XPS) spectrum clearly validates the substitution of Sm3+ ions in the 500 °C-annealed samples. The 500 °C-annealed nanorods exhibit combined performances of the wide band gap, improved UV absorbance, and vivid green luminescent emission (563 nm). Additionally, the nanorods have favorable UV-blocking execution of 96% for UVA at 360 nm, 92% for UVB at 320 nm, and 57% for UVC at 225 nm, which is greater than the majority of ZnO-related materials that have been reported up to this date. Sm doping is also appropriate for improving bacterial inhibition against the two studied strains (Escherichia coli and Staphylococcus aureus), in addition to the intriguing features discussed above. Furthermore, with maximum inhibition zone diameters of 20 ± 0.72 and 18 ± 0.57 mm, respectively, these nanorods exhibit high inhibitory action against E. coli and S. aureus bacterial strains. The rare earth-doped material developed during the current experiment, which was annealed at 500 °C, could potentially serve as an effective replacement for UV-blocking and antibacterial material, especially for biomedical applications.

A DFT study on the effect of lattice defects on the electronic structures and floatability of spodumene

The influences of lattice vacancies and lattice impurities on the electronic structures and floatability of spodumene were studied by the density functional theory (DFT) through analysis of partial density of states (DOS), Mulliken population, differential charge density, and frontier molecular orbitals. The calculation indicated that the effect of lattice Al, Si, and Li vacancies on the DOS, Mulliken population as well as the interaction between spodumene and oleate was insignificant. Cr, Fe, and Mn impurities caused the shift of Fermi level towards lower energy and the occurrence of peaks of impurity near Fermi level. K and Na impurities contributed little to the lowest unoccupied molecular orbital (LUMO) of spodumene, while Cr, Fe, and Mn impurities had great contribution, suggesting that Cr, Fe, and Mn impurities significantly affected the interaction between spodumene and oleate. The frontier molecular orbitals analysis indicated Cr, Fe, and Mn impurities are in favor of oleate adsorption.

Sulfate consumption during the hydration of Alite and its influence by SCMs

AbstractSCMs with a large specific surface area, such as calcined clays or fine limestone powder, can significantly accelerate the occurrence of the aluminate heat flow peak during the early hydration of blended cements. These systems therefore require a higher amount of sulfate. While this effect has been drawn back to the sulfate incorporation into C‐S‐H, which is formed more rapidly due to the filler effect, it has been recently shown that in systems with high amounts of metakaolin, the sulfate balance is influenced by further mechanisms. This study provides new results on the influence of aluminum‐rich and aluminum‐free SCMs on the early hydration of alite in presence of calcium sulfate. A synthesized alite was blended with 5 wt% of anhydrite and its hydration was investigated by isothermal calorimetry and in‐situ XRD at a w/b ratio of 0.5. It was shown that the formed C‐S‐H is able to take up the calcium and sulfate ions, indicated by a depletion of the solid anhydrite after approximately 20 hours. This process is significantly accelerated by incorporating 30 wt% of a fine limestone filler. The addition of metakaolin leads to an acceleration of the alite hydration compared to the reference as well, but to a significantly lower extend compared to the limestone. However, this system requires a lower degree of alite reaction to reach sulfate depletion. This indicates that in metakaolin‐rich systems, the sulfate demand is influenced by further effects. The results from in‐situ‐XRD reveal that significant ettringite formation is taking place in the metakaolin‐blended system already during the first hours of hydration. Correlations between the degree of alite hydration and the rate of sulfate depletion provide new insights into the mechanisms affecting the sulfate balance and early hydration of blended cements.

Seasonal Variation of Rainfall in Indonesia under Normal Conditions without ENSO and IOD Events from 1981-2021

This study explores the seasonal rainfall variation in Indonesia under normal conditions, excluding the influence of El-Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) events. Monthly rainfall data is sourced from the CHIRPS dataset, and wind and atmospheric movement data are obtained from the ECMWF ERA-5 dataset. Identification of normal conditions relies on the ONI and DMI indices. Results reveal that the seasonal rainfall patterns during these normal conditions align with previous studies encompassing all atmospheric conditions. Indonesia typically witnesses one or two peaks in rainfall annually, notably in December-January-February (DJF), May-June (MJ), and March-April-May (MAM), consistent with established rainfall zone classifications in earlier research. A nuanced discrepancy emerges in the timing of the May-June peak, previously noted in June-July. The congruence in peak rainfall patterns during normal conditions, as observed in prior comprehensive research, implies a negligible influence of ENSO and IOD on the timing of seasonal rainfall peaks. Although ENSO and IOD may impact the amplitude of seasonal variation, particularly in Indonesia's eastern and western regions, they do not alter the temporal occurrence of rainfall peaks. Consequently, the timing of rainfall peaks in Indonesia predominantly reflects the combined influence of the Asian and Australian monsoons.

Effects of Multi-Walled Carbon Nanotube Dosages and Sonication Time on Hydration Heat Evolution in Cementitious Composites.

This study aimed to investigate the heat generated during the hydration process in cementitious composites containing multi-walled carbon nanotubes (MWCNTs). The cumulative heat release and heat flow of these cementitious composites were measured over a period of 168 h using isothermal calorimetry. Three different MWCNT dosages, 0.05 wt%, 0.1 wt%, and 0.2 wt%, along with two different sonication times for the solution, which were 20 min and 60 min, were applied in the experimental program. The results reveal that the incorporation of MWCNTs and the use of a naphthalene-based superplasticizer to disperse the nanotubes generally led to a reduction in heat emission during the early stages of hydration, a lower first peak value in the initial stage of hydration, and a significant delay in the acceleration period compared with the reference sample lacking this superplasticizer. Furthermore, the results demonstrate that both the dosage of multi-walled carbon nanotubes (MWCNTs) and the sonication time have an impact on the heat emission and hydration process since the same amount of superplasticizer was applied to all pastes. An increase in the MWCNT dosage led to a decrease in the rate of hydration heat at the main peak for all pastes. Additionally, longer sonication times resulted in lower values of heat generated, reduced main peak values in the heat rate evolution, and generally extended delays in the occurrence of the main peak.

Experimental study of dynamic melting process in an ice-on-coil storage system

Ice storage air conditioners in the field of refrigeration and air conditioning have the ability to effectively regulate the power load curve by mitigating the occurrence of high peaks and filling in the low troughs in power consumption. In order to enhance the applicability of the ice-storage air conditioner, a method of experimental analysis was utilized to incorporate a dynamic circulation system into the specially designed ice-melting ice storage tank. The system consists predominantly of circulation pumps, transportation tubes, and sprinkler nozzles. The study examined the effects of several parameters, including the arrangement of sprinkler nozzles, the flow rate of the sprinkler nozzles, the temperature of the brine at the inlet, and the flow rate of the brine, on the performance of the system. The assessment of the performance was conducted by considering the average discharge rate, total discharge capacity, duration of melting, discharge rate, and the distribution of temperature within the phase change material (PCM) tank. Based on the empirical findings, the dynamic ice melting system exhibited a notable increase in the average discharge rate, ranging from 60.7 % to 89.2 %, as compared to the static ice melting system. The duration of ice melting experienced a decrease ranging from 45.3 % to 54.3 %, while the distribution of temperature in the tank containing PCM exhibited a greater level of uniformity in comparison to the process of static ice melting. The staggered arrangement of nozzles has demonstrated superior effectiveness in terms of parameter impacts. The study revealed a positive correlation between the rate at which ice melts and the flow rate of the sprinkler, the temperature at which brine enters the system, and the rate at which brine flows.

Determination of the distribution of relaxation times through Loewner framework: A direct and versatile approach

In this work, a direct data-driven approach is employed to extract the distribution of relaxation times (DRT) from impedance data. The proposed procedure is based on the Loewner framework, that is a data driven methodology with theoretical basis in the linear system theory. One of the main advantages is that the DRT can be computed without need of regularization procedures or iterative optimization algorithms. We test the Loewner framework based algorithm on synthetic impedance data generated through equivalent circuit models widely used for modeling electrochemical systems. Impedance data set including noise are also processed. In addition, experimental electrochemical impedance spectroscopy (EIS) data are analyzed. The study shows a significant improvement in the accuracy and a high versatility of the methodology. However, the presence of significant amount of noise compromises the reliability of the obtained DRT due to the occurrence of artifact peaks. Some recommendations how to deal with noisy data are discussed.

The Random Vibrations of the Active Body of the Cultivators

The article continues the exposition of the results obtained in researching an agricultural machine for processing soil, designed for research with applications including exploitation. The MCLS (complex machine for soil tillage) was designed to research the working processes of the instruments intended for soil processing. The MCLS cultivator is a modulated machine (it can work for three working widths: 1, 2, and 4 m, with tractors of different powers) that is designed to use a wide range of working bodies. The experimental data obtained with the structure with a working width of 1 m and the results of their processing within the framework of the theory of random vibrations are presented in this article. The experimental results are analysed as random vibrations of the supports of the active working bodies. As a result, the main characteristics of random vibrations are exposed: the distribution function, the average value, the autocorrelation, and the frequency spectrum. These general results regarding random vibrations are used for several critical applications in the design, execution, and exploitation of some subassemblies and assemblies of agricultural machines of this type. The main applications include estimating the probability of the occurrence of dangerous load peaks, counting and selecting the load peaks that produce fatigue accumulation in the material of the supports of the working bodies, identifying some design deficiencies or defects in the work regime, and estimating the effects of vibrations on the quality of soil processing. All of the outcomes are composed of applications in MCLS research and exploitation. The applications pursue well-known objectives of modelling the working processes of agricultural machines: safety at work, increasing the quality of work, optimising energy consumption, and increasing productivity, all in a broad context to obtain a compromise situation. The material and the method are based on experimental data acquisition, processing, and interpretation.

Experimental Investigation of the Frequency Response of an LC-Filter and Power Transformer for Grid Connection

The power delivered by a voltage source inverter needs to be filtered to fulfill grid code requirements. A commonly used filter technology is the LCL-filter. An issue with the LCL-filter is the occurrence of a resonance peak, which can be mitigated with active or passive damping methods. The transfer function of the filter is often used to investigate the frequency response of the system and propose damping methods. The use of an LC-filter combined with a power transformer to form an LCL-filter has not been extensively investigated. Therefore, the study in this article introduces a model for an LC-filter and power transformer for the grid connection and a derived transfer function for the model. The transfer function for the system is validated with simulations and experimental investigations. The results from simulations and the results from a direct solution of the derived analytical function overlap almost perfectly. The magnitudes of the experimental results are approximately 1 dB lower than the simulation and analytical results before the resonance frequency. At the resonance frequency, the experimental results are approximately 13.4 dB lower. The resonance frequency, however, occurs at approximately the same frequency. It is also concluded that the system is significantly damped.

Changes in the physicochemical properties of isolated starch and plantain (Musa AAB Simmonds) flours for early maturity stage

This work focuses on the study of the physicochemical changes that take place during the first stage of ripening of plantain, with particular attention to the changes in the orthorhombic and hexagonal nanocrystals present in this starch, and its relation shift with resistance starch. Significant changes were observed in the proximal analysis of plantain flour. A gradual increase in moisture content was attributed to the high content of crystalline structures and molecules that can be removed by drying. Water activity increased with ripening, which was attributed to the hygroscopic nature of the flours. The protein content increased, and the carbohydrate content decreased, indicating the progress of biochemical reactions. The changes in the fat content are consistent with the hydrolysis and resynthesis of lipids during the ripening process. The obtained results indicate a significant influence of the ripening stage on the physicochemical properties of flour and starch of plantain, which is associated with the occurrence of a climacteric peak on the 4th day of ripening.The hydration properties of plantain flour decreased significantly during the ripening days, consistent with the occurrence of a climacteric peak. Water holding capacity (WHC) and water binding capacity (WBC) were affected by the degree of digestion of native starch granules and protein denaturation during fruit ripening. Scanning electron microscopes (SEM) showed that during ripening the surface of the isolated starches do not suffer any significative damage. X-ray diffraction patterns were used to identify crystalline structures and to study the changes in the crystalline structures. These results showed that the starch contains orthorhombic and hexagonal nanocrystals, which play and important role and which show small structural damage during ripening reflected in a decrease in their relative crystallinity. This is the first time that these nanocrystals have been studied and considered in the ripening process. Differential scanning calorimetry was used to study the thermal transition in isolated starch. The results indicated that the gelatinization of starch corresponds to the solvation of orthorhombic and hexagonal nanocrystals, and that during ripening there is a decrease in the enthalpy reflecting some crystal structural damage. Pasting properties were studied using a Starch cell for flours and isolated starches, indicating that the pasting profile is governed by intrinsic and extrinsic factors. The resistant starch does not show significant changes at this stage of maturation. This starch is the one with the highest resistant starch content reported in the literature (38%). It was hypothesized that the resistant starch is directly related to the amount of whole starch granules, and more importantly, directly related to the number concentration of orthorhombic and hexagonal nanocrystals. Therefore, knowledge of the physicochemical and nutritional properties of plantain and flour at each stage of ripening allows better selection according to industrial applications.

Reviewing the geodynamic impact of aseismic ridges subduction on the tectonic-magmatic evolution of the Southern Puna plateau

The Southern Puna (∼24° S to 27° S) is an outstanding segment of the Central Andes where the subduction of aseismic ridges, multi-scale lithospheric foundering, and the transition from normal Andean subduction to the Chilean-Pampean flat slab occur. The exponential increase in the volcanological and geophysical knowledge of the Southern Puna provides a unique opportunity to reappraise its geodynamic evolution. This paper presents an updated review of the spatial-temporal distribution of the volcanism along with a reassessment of the main geophysical and morphostructural features of this region. Contrasting our observations with new kinematic reconstructions of the Taltal and Copiapó ridges, we infer that their subduction under the Southern Puna plateau has played a fundamental role in its Neogene-Quaternary geodynamic evolution (e.g shallow subduction, lithospheric delamination). Specifically, we propose a new alternative hypothesis where the Transversal Volcanic Chains (TVCs), characterizing the Southern Puna, are related to slab tearing. Slab tearing is a valid explanation for the occurrence of local anomalous peaks of melt productivity in a relatively cold retreating mantle wedge during slab shallowing. In our model, slab tearing under the Southern Puna was influenced by the flexural deformation related to slab dip changes as a result of the anomalous slab buoyancy during the subduction of Copiapó and Taltal ridges.

The Impact of Microelectrode Pattern on the Sensitivity of Tracing Environmental CO2 Deficiency in Cellular Metabolism by a New Design of Electrochemical Biosensor.

Here, two different electrode patterns are described as cyclic voltammetry (CV) biosensors to detect the effect of a hypo CO2 condition (for 6 h) in ambient on cellular secretion. The cells were selected from breast cancer and endothelial standard lines. Changes in CV peaks of the secretions were recorded by the modified pattern whereby increasing the interactive surface with homogenous electric paths was considered by simulation before fabrication. The results of the simulation and experimental procedures showed a meaningful correlation between hypo CO2 samples and the occurrence of CV oxidative peaks at about 0.07 V and reductive peaks at approximately -0.22 V in the modified biosensor in all cell lines, while no apoptosis was found in any of the control and hypo CO2 samples. This observation could not be related to the lack of H+ (alkaline pH induction) in the media solution as such peaks were not observed in the pure cell culture medium but had been maintained in the hypo CO2 ambient. This approach could be used as a cell-free sensor to monitor ambient shocks. This may not induce apoptosis but may be vital in the proliferation and protein expression of the cells, such as the hypo CO2 ambient. The sensor is not disposable in use and showed repeatable responses after rinsing.

Hydrothermal synthesis of dual emission carbon dots with yellow fluorescence for ratio detection of Al3+

Dual-emission carbon dots with strong yellow fluorescence (Y-CDs) were prepared by one-step hydrothermal method from p-aminophenol and ethylenediamine. Two emission centres appeared at 380 nm and 520 nm under excitation of 270 nm. After adding Al3+, the fluorescence at 520 nm decreased due to static quenching, while the fluorescence at 380 nm gradually increased. Therefore, it could be used for ratiometric detection of Al3+. In addition, the synthesized Y-CDs were concentration dependent, and the occurrence of dual emission peaks was considerably related to the concentration. When the concentration of Y-CDs decreased, the intensity of its emission peak at 380 nm gradually increased. There was an excellent linear relationship between the concentration of synthesized Y-CDs and the ratio of two emission peaks after adding Al3+, which had been used for the detection of Al3+ in actual water samples. Moreover, the synthesized Y-CDs were successfully applied to A549 cell imaging.

Development of an Extreme Wind-Driven Rain Climatology for the Southeastern United States Using 1-Min Rainfall and Peak Wind Speed Data

Abstract A method is presented to obtain the climatology of extreme wind speeds coincident with the occurrence of rain. The simultaneous occurrence of wind and rain can force water through building wall components such as windows, resulting in building damage and insured loss. To quantify this hazard, extreme value distributions are fit to peak 3-s wind speed data recorded during 1-min intervals with specific reported rain intensities. This improves upon previous attempts to quantify the wind-driven rain hazard that computed wind speed and rainfall-intensity probabilities independently and used hourly data that cannot assure the simultaneous occurrence of peak wind that represents only a several-second interval within the hour and rain that is accumulated over the entire hour. The method is applied across the southeastern United States, where the wind-driven rain hazard is most pronounced. For the lowest rainfall intensities, the computed wind speed extremes agree with published values that ignore rainfall occurrence. Such correspondence is desirable for aligning the rain-intensity-dependent wind speed return periods with established extreme wind statistics. Maximum 50-yr return-period wind speeds in conjunction with rainfall intensities ≥0.254 mm min−1 exceed 45 m s−1 in a swath from Oklahoma to the Gulf Coast and at stations along the immediate Atlantic coast. For rainfall intensities >2.54 mm min−1 maximum, 50-yr return-period wind speeds decrease to 35 m s−1 but occur over a similar area. The methodology is also applied to stations outside the Southeast to demonstrate its applicability for incorporating the wind-driven rain hazard in U.S. building standards. Significance Statement Rainfall driven horizontally by strong winds can penetrate building components and cladding. If unmanaged, this can directly damage the building and its contents and become a substantial component of insured losses to buildings. A climatology of wind-driven rain is developed from recently available 1-min weather observations that better represent the joint occurrence of the extremes that define wind-driven rain occurrence than hourly data. This work is a first implementation of 1-min data into extreme-value statistical models, providing a basis for including wind-driven rain in United States building codes. This inclusion would be most significant in the hurricane-prone regions of the southeastern United States. The omission of wind-driven rain in U.S. building codes contrasts to its inclusion in Europe and Canada.

P-635 RELATION BETWEEN THE TIME OF CONTROLLED OVARIAN STIMULATION IN PROGESTIN AND GnRH ANTAGONIST PROTOCOLS AND THE OUTCOMES OF IVF – A RETROSPECTIVE OBSERVATIONAL STUDY

Abstract Study question Comparison between IVF outcomes of two controlled ovarian stimulation (COS) protocols (the antagonist protocol and the progestin protocol) and their duration. Summary answer This data suggests that the protocols have comparable efficiency on the ovarian stimulation, leading to similar outcomes on IVF treatments. What is known already Both protocols aim to prevent early ovulation by blocking the LH surge but have slightly different mechanisms: the antagonist protocol uses a GnRH antagonist to block LH whereas in the progestin protocol a progestogen is administered. The aim of COS is to stimulate follicular growth for oocyte punction, avoiding an early ovulation. In this sense, some studies have shown that the use of oral dydrogesterone can offer a more stable maintenance of LH levels, with less occurrence of an early peak of this hormone, leading to fewer cases of premature ovulation and cycle cancellation. Study design, size, duration In this retrospective observational study data were collected from patients undergoing in vitro fertilization (IVF) treatment at Instituto Ideia Fértil between September 2019 and September 2020. The study was submitted to the evaluation of the Ethics and Research Committee (CEP) of the Faculdade de Medicina do ABC (CAAE: 54150621.8.0000.002) and approved. A total of 447 patients were included in the study, with 205 undergoing the antagonist protocol and 242 the progestin protocol. Participants/materials, setting, methods The participants were women of reproductive age that have undergone IVF at Instituto Ideia Fértil between September 2019 and 2020. They were divided between two groups: L-COS, which refers to cycles lasting ≥ 9 days, and S-COS, with cycles lasting ≤ 8 days. The variables included in the statistical analysis were: age, basal antral follicle count, and numbers of days of COS, collected and MII oocytes, zygotes, cleaved embryos and blastocysts. Main results and the role of chance Of the 447 patients, 392 underwent L-COS and 55 S-COS. Mean age was 38.5. When comparing groups, there was no statistical difference in the basal AFC (antral follicle count), average of recovered oocytes, mature oocytes, cleaved embryos, and blastocysts. There was a difference in the mean number of zygotes, which was greater in the L-COS group (2.77 ± 2.38 - 2.05 ± 2.16; p < 0.05). However, the final outcome did not show superiority, since the number of cleaved embryos and blastocysts did not show a significant difference. There were no significant differences between the L-COS and S-COS groups of women submitted to the progestin protocol for any outcomes. When comparing the outcomes of the L-COS and S-COS groups of women submitted to the antagonist protocol, a significant difference in the basal AFC was observed, which was higher in the L-COS group (3.87 ± 1.69 - 3.0 ± 1.57; p < 0.05), which may justify the need for more days of ovulation induction for oocyte growth and maturation. No other outcomes showed a significant difference between groups. Therefore, the duration of the COS does not appear to have an impact on outcomes in either the progestin or antagonist protocols. Limitations, reasons for caution The limitations of this study are the lack of data on BMI (body mass index), pregnancy rate and live birth rate, which does not allow us to analyze the future success of each of the ovarian stimulation protocols or trace the relationship between BMI and IVF. Wider implications of the findings This study showed no relevant differences between protocols. As the progestin protocol is cheaper and easier to administer and seems to have the same quality as the antagonist protocol it might be an interesting alternative, despite another step on the treatment, the freeze all. Trial registration number CAAE: 54150621.8.0000.002

Secondary electron emission from magnetron targets

Ion-induced secondary electron emission of surfaces occurs in all gas discharges which have contact to surfaces such as electrodes or chamber walls. These secondary electrons (SEs) play an important role, for instance, in the performance of DC discharges, RF discharges and magnetron sputtering discharges. SE generation can be separated into potential electron emission (PEE) due to the neutralization of the incident ion upon impact and kinetic electron emission (KEE) due to the electronic stopping of the penetrating ion in the solid. SE due to neutralization is usually described by Auger processes and the density of states of the electrons in the solid, whereas KEE scales with the electronic stopping of the ion in the solid, as being calculated by ion collision simulations. The measurement of the energy distribution of the SEs of three metals (Al, Ti, Cu) and their oxides reveals the occurrence of Auger peaks, which are not reflected by standard models such as the Hagstrum model. Instead, in this paper, a model is proposed describing these Auger peaks by Auger neutralization of holes created by the collision cascade of the incident ion. This shows decent agreement. The contribution of Auger peaks in the metals Al and Ti is very significant, whereas it is negligible in the case of Cu. The implication of these energy distributions to the performance of magnetron sputtering discharges is discussed.

Effects of controlled release silica nanocapsules containing sucrose on the heat release of cement hydration

The usage of chemical admixtures, such as starch-based materials, is a common approach to addressing the thermal cracking problem of cementitious materials. Capsule-based controlled release technique enables the adjustable action time of loaded chemical admixture and thus reveals the potential on inhibiting the exothermic process of cement hydration. Three types of silica-based nanocapsules loaded with 53–63% sucrose retarder are firstly prepared by interfacial polymerization in water-in-oil (W/O) emulsion. The release characteristics of three types of nanocapsules are precisely tuned by varied preparation conditions. The effects of nanocapsules on the exothermic process of cement hydration have been investigated through calorimetry measurements. All prepared nanocapsules not only delay the appearance of the main hydration peak as the retardation effect but also reduce the maximum heat flow of the main hydration peak, to some extent, as the depression effect. The depression and retardation effects are improved with the increased dosage and slower release rate of added nanocapsules. The relationship between the two effects and the action time of loaded sucrose suggests the importance of persistently inhibiting the cement hydration over the entire accelerating and decelerating processes, which can be estimated by the time window between the action of sucrose (50% release time) and occurrence of main hydration peak.