Search

We evaluated the thermal and chemical stratifications of Paldang Lake using Schmidt's stability index (SSI) and the chemical stratification index (IC-i) with weekly data from 2013 to 2022. The temporal trends of stratification were analyzed alongside correlations with meteorological, hydrological, and water quality variables. Thermal stratification intensified with rising air temperature and sunshine duration, while hydrological factors like discharge and retention time affected SSI during periods with less than five days of water retention. During summer, fewer occurrences of intense rainfall or early rainfall before August led to stronger stratification. In fall, nutrient influx from external sources during summer stimulated algal growth, increasing Chlorophyll-α (Chl-α) concentrations. Summer rainfall had a significant impact on the strength and duration of stratification in Paldang Lake. Annual rainfall patterns and subsequent changes in discharge were key factors affecting the physical environment of the lake, which in turn determined water quality and the extent of algal blooms. We provide insights into the seasonal stratification and water quality variations in temperate river-type reservoirs like Paldang Lake. SSI and IC-i from this research can be applied to understand stratification and mixing dynamics in other lakes. [ABSTRACT FROM AUTHOR]

Stability estimates are proposed for two variants of Markov processes defined by stochastic difference equations: uncontrolled and controlled. Processes of this type are widely used in applications where their “governing distributions” are known only approximately, for example, as statistical estimates obtained from real data. Therefore, the problem of estimating deviations of output characteristics arises. The Kantorovich metric is used to measure the variations of probability distributions that govern the processes. In the uncontrolled case, the Kantorovich distance between the stationary distributions of the initial process and its perturbation is evaluated. On the other hand, the control processes being compared are endowed with an expected total discounted cost, and the inequality for the corresponding stability index is obtained. The stability index measures the increase in costs when using the control policy optimal for the “approximating process.”

The increase in population growth and the demand for food supply and the high percentage of waste production in the food supply chain are among the reasons for increasing attention to the issue of waste management in the world. Due to its huge volume of important nutrients, food waste offers a lot of potential for animal feed production. The goal of this research was to examine the energy and exergy requirements for producing animal feed from food waste using a dryer in two states: reverse flow and non-reverse flow. Hot air is mixed with fresh air in reverse flow but in nonreverse flow fresh air is used. Food waste is collected from kitchen. Food waste was dried at three temperatures of 55°C, 70°C, and 85°C in three times of 90, 150, and 210 min after the dryer was set up in two conditions of return and nonreturn flow. The results showed that the quantity of energy spent is decreased to one-third of the non-return state due to the reuse of output energy. Exergy waste will be decreased by up to 11.5 times. Increasing device efficiency and lowering expenses entails decreasing wasted exergy. Furthermore, the modifications in the stability index mean that the amount of pollutants produced by reverse flow will be lower. [ABSTRACT FROM AUTHOR]

Background: Neck pain is one of the most burdensome chronic musculoskeletal problems globally. Impaired proprioception is associated with chronic nonspecific neck pain as the structures of the cervical spine are crucial for proprioception and balance. There is a paucity of literature examining objective measures of balance and postural sway in patients with nonspecific neck pain. Methods: This study was observational consisting 126 individuals (63 cases and 63 controls) who were recruited using convenience sampling. The demographics of the samples were collected and the postural and balance impairment was assessed using Biodex Balance SD. Mean, Median, and SD were obtained and the inferential analysis was done using the Whitney U Test and the level of significance was accepted at p < 0.05. Results: The subjects with neck pain showed had a lower static stability index, static sway index, static stability index—forward backward and static sway index lateral scores than the normal counterparts. There are significant differences in the overall static stability index (p < 0.001). There was a significant difference in static sway index (p = 0.003) and static stability index lateral (p = 0.004). There was no significant difference for static sway index forward and backward (p = 0.550) and lateral sway index (p = 0.711). Conclusion: Subjects with neck pain had a lower static stability index, static sway index, static stability index—forward backward, and static sway index lateral scores than the normal counterparts and there was a significant difference between the static sway and static stability index in forward and backward directions as well as in lateral direction. These findings may help to assess the specific balance parameters and address the underlying causes of balance issues in patients with neck pain and also provide a comprehensive care to the patients. Clinical Trial Registration: The trial was registered with CTRI India with registration number: CTRI/2022/07/044222. [ABSTRACT FROM AUTHOR]

ObjectiveTo explore the biomechanical factors affecting the stability of athletes in the 143D balance phase of competitive Tai Chi.MethodThe Vicon 3D motion capture system, Kistler 3D force platform, and Noraxon surface electromyography (sEMG) system were used to measure the joint angle, joint moment, center of gravity, ground reaction force, and sEMG data of athletes. The stability index was then calculated according to the formula. Pearson’s or Spearman’s correlation tests were used to analyze the associations between the biomechanical factors and stability index.Results(1) Medial lateral stability index (MLSI): A significant negative correlation was found between the ankle inversion angle of the supporting leg (SL) and MLSI (p < 0.05). (2) Anterior posterior stability index (APSI): Significant negative correlations were observed between the ankle intorsion angle, integrated electromyography (iEMG) of the gastrocnemius, and muscle contribution rates of the tibialis anterior, external oblique, and gastrocnemius of the non-supporting leg (NL) with the APSI (p < 0.05). The ankle dorsiflexion moment, iEMG of the rectus femoris and tibialis anterior, muscle contribution rate of the biceps femoris, and root mean-squared (RMS) amplitude of the gluteus maximus of the SL also showed significant negative correlations with the APSI (p < 0.05). Strong and significant negative correlations were also identified between the hip intorsion angle, iEMG of the tibialis anterior, and RMS amplitude of the rectus femoris of the NL with the APSI (p < 0.01). Further strong and significant negative correlation was also found between the RMS amplitude of the biceps femoris of the SL and APSI (p < 0.01). The knee extorsion angle of the NL was positively correlated with the APSI (p < 0.05). (3) Dynamic postural stability index (DPSI): The knee adduction angle, iEMG of the tibialis anterior, and RMS amplitude of the erector spinae of the NL were significantly positively correlated with the DPSI (p < 0.05). The knee abduction and hip extension moments of the SL were also significantly positively correlated with the DPSI (p < 0.05).ConclusionThe ankle inversion angle of the SL impacts left–right stability, while the NL’s hip and ankle intorsion angles, knee extorsion angle, and exertion on the core muscle and SL’s main muscles, as well as exertion of specific muscles of the NL affect anterior–posterior stability. The hip extension and knee abduction moments of the SL, knee adduction angle, exertion on the tibialis anterior, and activation of the erector spinae of the NL significantly affect the overall stability of an athlete.

Stabilization and dewatering are essential treatment mechanisms for the management of fecal sludge (FS) that accumulates in onsite containment, but reliable predictors of treatment performance are lacking. FS in Lusaka, Zambia is typically 80–98% water, which when delivered to treatment first requires dewatering, followed by stabilization of varying levels of organic matter. In addition, varying levels of stabilization are themselves observed to influence dewatering performance. Therefore, this study evaluated rapid and low-cost metrics of stabilization and their relation to dewaterability. Fourteen metrics of stabilization were evaluated based on 11 criteria in a decision matrix. Four metrics were selected to then evaluate method performance and suitability with FS samples (n = 27). The relation between stabilization and dewatering performance of collected samples were analyzed, and also following anaerobic stabilization in the laboratory. The study found that metrics based on physical–chemical characteristics such as volatile/total solids (VS/TS) and biological oxygen demand/chemical oxygen demand (BOD/COD) were not reliable for measuring FS stabilization and its relation to dewaterability. Metrics that rely on microbial activity such as SOUR (specific oxygen uptake rate) are more promising based on the consistent results obtained throughout this study. HIGHLIGHTS Agreed-upon metrics of stabilization are needed for fecal sludge.; Metrics for wastewater and compost were evaluated for their applicability to fecal sludge.; Biological metrics (e.g. SOUR) are more representative than physical–chemical characteristics (e.g. VS/TS).; Anaerobic digestion, stabilization metrics, and dewatering performance were not consistent.;

Alfalfa (Medicago sativa L.) is used to support livestock. A stability study was carried out over three years. The stability indices for yield and main quality characteristics such as plant height, number of nodes, the yield of green mass and dry matter, crude protein and fiber (%), and ash (%), were examined. Statistical analysis revealed significant differences that indicated the presence of high genotype–year interactions. Heritability was higher in the case of qualitative traits than quantitative traits. The most intriguing correlation was between green mass yield and crude protein content because positive correlations may lead to indirect and simultaneous selection. According to the statistical biplot models AMMI and GGE, the best genotypes for almost all traits to use, regardless of the environment and cultivation type, were the G8 (Population 2) followed by cultivar G3 (Yliki). Despite the high index values shown by the parameter number of nodes, the latter and yield showed low heritability. [ABSTRACT FROM AUTHOR]

Abstract Background Neck pain is one of the most burdensome chronic musculoskeletal problems globally. Impaired proprioception is associated with chronic nonspecific neck pain as the structures of the cervical spine are crucial for proprioception and balance. There is a paucity of literature examining objective measures of balance and postural sway in patients with nonspecific neck pain. Methods This study was observational consisting 126 individuals (63 cases and 63 controls) who were recruited using convenience sampling. The demographics of the samples were collected and the postural and balance impairment was assessed using Biodex Balance SD. Mean, Median, and SD were obtained and the inferential analysis was done using the Whitney U Test and the level of significance was accepted at p

Sounding rockets constitute a class of rocket with a generally simple layout, being composed of a cylindrical center-body, a nosecone, a number of fins placed symmetrically around the longitudinal axis (usually three or four), and possibly a boat-tail. This type of flying craft is typically not actively controlled; instead, a passive stabilization effect is obtained through suitable positioning and sizing of the fins. Therefore, in the context of dynamic performance analysis, the margin of static stability is an index of primary interest. However, the classical approach to static stability analysis, which consists in splitting computations in two decoupled domains, namely, around the pitch and yaw axis, provides a very limited insight to the missile performance for this type of vehicle due to the violation of the classical assumptions of planar symmetry and symmetric flight conditions commonly adopted for winged aircraft. To tackle this issue, this paper introduces a method for analyzing static stability through a novel index, capable of more generally assessing the level of static stability for sounding rockets, exploiting the same information on aerodynamic coefficients typically required for more usual (i.e., decoupled) static stability analyses, and suggests a way to assess the validity and shortcoming of the method in each case at hand. [ABSTRACT FROM AUTHOR]

The use of grazing management strategies can influence canopy structure and the permanence of legumes. The objective of this work was to evaluate the determination of forage canopy heights as a grazing management strategy regarding herbage mass composition and tiller population dynamics in multispecies pastures comprising Megathyrsus maximus cv. Aruana and the legumes Macrotyloma axillare, Calopogonium mucunoides and Stylosanthes spp. Four treatments, defined by canopy heights of 15, 30, 45 and 60 cm, were evaluated in a randomised block design with four replications. The evaluations were performed under continuous stocking with sheep. Taller pastures (45 and 60 cm) contained greater (P

This article presents an approximation of discrete Markov decision processes with small noise on Borel spaces with an infinite horizon and an expected total discounted cost by the corresponding deterministic Markov process. In both cases, the dynamics evolve through a system consisting of two coupled difference equations. It is assumed that the difference equations of the system are perturbed by a small noise. Under our assumptions, a bound for the stability index is given, and the optimal cost convergence rate is estimated using a small perturbation parameter. Moreover, the convergence of the optimal policy on compact subsets is verified. Finally, two examples are presented to illustrate the developed theory.

This paper presents a preliminary examination of voltage stability in the context of enhancing the transmission system of Laos Electricity (EDL) Central 1. Real SCADA data from the EDL database are used to evaluate common stability indices, namely the Fast Voltage Stability Index (FVSI), Line Stability Factor (LQP), and Line Stability Index (Lmn). The weakest bus and the most sensitive line are determined by ranking the stability indices. Furthermore, the sensitivity of the bus and the load capability of the line are assessed. The stability analysis is conducted under different load conditions, and the results are compared with actual interruption data. The case study identifies substations No. 5 and No. 8, along with the corresponding lines Phontong–Donekoy and Naxaythong–Pontong, as the most vulnerable areas in the central 1 region. Improving the load capability of these lines is critical to increasing the stability of the EDL Central 1 system.

With the growing usage of renewable energy technologies like wind power and photovoltaics, and the increased integration of FACTS (Flexible Alternating Current Transmission System) devices into the power system, the transient characteristics of the evolving power system undergo changes that require appropriate analysis methods. As a new type of FACTS device, TCPST (Thyristor Controlled Phase Shifting Transformer) is introduced to facilitate the superior operation of renewable energy sources by controlling the power flow of access branches. From the perspective of branches, the dynamic characteristics of renewable energy sources and TCPST might be uniformly studied and simply calculated in the transient stability analysis. Therefore, the paper proposes a transient stability analysis method for wind power systems with TCPST based on the branch potential energy index. First, considering the variation characteristics of branch potential energy, this paper employed the stability index to analyze the transient stability of branches and the system by finding vulnerable lines. Then, based on the stability index, the paper investigates the influence of wind turbine removal, the installation and control parameter adjustment of TCPST on the transient stability of wind power systems. The simulation results in PSAT demonstrate that the removal of a proper amount of wind turbine post-fault and the installation of TCPST can improve the transient stability of the wind power system. Furthermore, it can also be improved by reasonably adjusting the TCPST control parameters. All simulation results are verified by the time domain simulation method.

Faba beans are considered one of the most important crops for animal feed. The genotype × environment interaction (GEI) has a considerable effect on faba bean seed production. The objectives of this study included assessing multiple locations and genotypes to understand how various ecosystems and faba bean genotypes relate to one another, and suggesting the ideal climatic conditions, crop management system, and genotypes so that they are carefully chosen for their stability. A 2-year experiment was conducted in order to define the stability across four environments based on stability indices for certain characteristics: moisture (%), ash content (%), crude protein content (%), crude fat (%), total starch (%), and crude fiber content (%). Statistically significant differences indicated that GEIs were present. The heritability was generally high for qualitative traits in comparison with quantitative traits. The crude protein content, plant height, and thousand-seed weight were all positively correlated with the seed yield; however, the other qualitative variables were adversely correlated. The crude protein content of the cultivar Tanagra displayed a high stability index, followed by Ste1. Under conventional management, Tanagra demonstrated high values for the seed yield in Giannitsa and Florina. Ste1 and Ste2 are particularly promising genetic materials that showed high values under low-input conditions. The best genotypes to use and the most favorable environments/types of cultivation were the Tanagra cultivar, followed by the Ste2 genotype, according to the additive main effects and multiplicative interaction (AMMI) and genotype plus genotype-by-environment (GGE) biplot models. Earliness showed significant heritability values and very high stability indices, again indicating qualitative behavior according to genetic parameters. With the exception of the number of pods per plant, which demonstrated low heritability while having excellent index values, traits like seed yield showed relatively low-stability-based heritability values. Global efforts aimed at improving the genetics of faba beans might benefit from genotypes that exhibit consistent yields in various conditions. [ABSTRACT FROM AUTHOR]

Assessment of process stability is a key to ensuring the high quality of any product, service, activity, etc. The main tool for doing this is a Shewhart control chart. However, it becomes difficult to analyze hundreds or thousands of control charts at a time for some up-to-date complex processes. In order to solve this problem, various indicators of process stability have been recently proposed with the Stability Index (SI) being the latest one, and, in many opinions, the best one. We have thoroughly analyzed different suggestions and found many of them ambiguous and sometimes even harmful to practitioners. Some examples of possible problems with the SI are provided below. It is argued that abnormal values of the SI can be caused not only by process instability, but by non-homogeneity, non-randomness, nonnormality, and autocorrelation as well. It is proved that the SI can be helpful for practitioners as an index to attract primary attention to the process. A proposal to rename the SI and widen significantly its application is given. Finally, some ways that practitioners could use this index more effectively are discussed. [ABSTRACT FROM AUTHOR]

Herein, walnut without pellicle was utilized as the raw material for the production of fermented walnut milk. The factors affecting quality of fermented walnut milk were investigated. The formulation of stabilizer in fermented walnut milk was optimized by a single factor experiment and orthogonal test with the amount of carboxymethylcellulose sodium (CMC-Na), pectin and gellan gum as investigation factors. The stability index and sensory score were used as evaluation indices. Gas chromatography-mass spectrometry (GC-MS) combined with headspace solid-phase microextraction (HS-SPME) was used to characterize the volatile profile of walnut milk before and after fermentation. The results showed that the optimal formulation was 2.5‰ CMC-Na, 1.1‰ pectin and 0.3‰ gellan gum. Under these conditions, the walnut milk exhibited good stability and sour-sweet and delicious taste with the stability index 1.1 and sensory score 94.5. There was a great variability in aldehydes, ketones and alcohols and the aroma quality of walnut milk was significantly improved.

In increasing the efficiency of breeding work on the creation of spring soft wheat varieties information about the combinational ability of the source material is of great importance. In 2021-2022 in the conditions of the Kirov region the general and specific combinational ability of 8 varieties and 28 hybrids of the second generation of spring soft wheat was studied according to the degree of leaf septoria damage, grain size and yield. The studies were carried out under natural conditions of development on the leaves of Parastagonospora nodorum as the molecular-genetic affiliation of the causative agent of septoria blotch to this species had been established. As the result of the conducted studies, for further breeding work there were selected 14 resistant F2 hybrids characterized by average values of the resistance index and a slow growth of infection. According to the complex of selective-immunological traits, the hybrid Rosinka 2 × Tertsiya was isolated, combining resistance to septoria with a high mass of 1000 seeds (41.6 g) and yield (410.0 g/m2). The tolerant hybrid of the Stepnaya 50 × Daria was particularly noted, which with a high degree of damage (34.2 %) formed a large grain (42.6 g) and the maximum yield for the experiment (411.1 g/m2). The conducted dispersion analysis of the data obtained has shown that the spring wheat variety Tertsiya (Russia) has a significantly high overall combinational ability (ОСА) by all the studied traits and can be their source in breeding programs. Moreover, the Epos variety (Germany) is the most effective as a source of resistance to septoria; Egisar 29, Niva 2, Stepnaya 50 and Rosinka 2 (Russia) are sources of grain size; Daria (Belarus) is a source of high yield. As the result of the analysis of the dominance index in most of the studied hybrids, the additive effect of genes on the manifestation of resistance to leaf septoria and seeds size was found. The effect of heterosis by disease resistance was observed in 21.4 %, by weight of 1000 seeds – in 42.9 % and by productivity – in 50.0 % of the studied hybrid combinations.

Background: The stability index estimation algorithm was derived and applied to develop and implement a balance ability diagnosis system that can be used in daily life. Methods: The system integrated an approach based on sensory function interaction, called the clinical test of sensory interaction with balance. A capacitance and resistance sensing type force mat was fabricated, and a stability index prediction algorithm was developed and applied using the center of pressure variables. The stability index prediction algorithm derived a center of pressure variable for 103 elderly people by Nintendo Wii Balance Board to predict the stability index of the balance system (Biodex SD), and the accuracy of this approach was confirmed. Results: As a result of testing with the test set, the linear regression model confirmed that the r-value ranged between 0.943 and 0.983. To confirm the similarity between the WBB and the flexible force mat, each measured center of pressure value was inputted and calculated in the developed regression model, and the result of the correlation coefficient validation confirmed an r-value of 0.96. Conclusion: The system developed in this study will be applicable to daily life in the home in the form of a floor mat. [ABSTRACT FROM AUTHOR]

The stability of the atmosphere plays an important role in changes in air pollutant concentrations. Stable atmospheric conditions cause pollutant concentrations to reach high values, which degrades the air quality in a particular region. This study aims to reveal the relationship between atmospheric stability indices/parameters (thermodynamic indices) and changes in air pollutant concentrations. Pollutant concentrations of PM10, PM2.5, SO2, NO2, CO, and O3 were statistically analyzed for a 10-year (2013-2022) period for nine air quality stations located in the megacity Istanbul. Based on national and international air quality standards, 145 episode days were determined for the days when these parameters exceeded the threshold values. Five stability indices (Showalter Index – SI, Lifted Index – LI, Severe Weather Index – SWEAT, K Index – KI, Totals Totals Index – TTI), and three stability parameters (Convective Available Potential Energy – CAPE, Convective Inhibition – CIN, Bulk Richardson Number – BRN) were used to determine the stability of the atmosphere for episode days. It has been found that in cases where air pollutant concentrations are high, the stability parameters reveal the stability of the atmosphere better than the stability indices. It was also found that there was at least one vertical inversion layer on 122 of the 145 episode days, these layers mostly (84%) occurred between the surface and 850 hPa levels, and the layer thicknesses were mostly between 0-250 m (84%). [ABSTRACT FROM AUTHOR]

This study proposes an under-frequency load-shedding (UFLS) scheme based on a binary Archimedes Optimization Algorithm (BAOA) and the Weighted Sum Method (WSM) to maintain the stability of an islanded distribution system. These methods consider stability indices and load priorities to ensure effective load shedding during frequency deviations. The BAOA determines the optimal load shedding based on the stability index and power mismatch that minimizes the impact on critical loads while maintaining system stability in an islanded distribution system. The WSM determines the rank of the load to be shed based on four criteria: the load priority, the load category, the stability index, and the load size. Each load is assigned a weight based on its priority. These weight variables determine the order in which loads are shed during frequency deviations. The effectiveness of the proposed UFLS was tested on an 11 kV Malaysian distribution network with two mini hydro distributed generation systems. A comparative study was conducted based on five result outputs, including the number of loads shed, the size of the loads shed, the frequency undershoot, the frequency overshoot, and the time taken to achieve a stable frequency in three cases: base load, peak load, and peak load with photovoltaics (PV). The proposed UFLS showed the best results for 11 of 15 outputs (73.3%) for islanding events and 9 of 15 outputs (60%) for overloading events. The voltage profile and stability index, also, were improved after the proposed UFLS was applied. [ABSTRACT FROM AUTHOR]

Abstract Background Selection is one of the essential skills whereby breeders reduce the population size and increase the chance of success. Various selection methods with special applications have been developed. Superior genotypes are assessed according to interesting traits, including univariate, multivariate, phenotypic, genotypic, etc. Methods Mathematical calculation of the traits' importance based on the genetic makeup of investigated population (average degree of dominance/additive involved in the action of genes) and arbitrary genetic parameters is functional. In this paper, a general model for multivariate selection has been presented whereby the selection can be made for (a) more than one interesting trait, (b) the trait(s) with complex inheritance, (c) finding superior genotypes from among a large-scale population, (d) finding superior genotypes in segregating generations and (f) finding tolerant genotypes to stresses. This model is developed based on biometric concepts in four steps. MATLAB script is provided for the model, and users can easily apply that to identify the most suitable genotypes after data collection according to the breeding purposes. Results The main features of this model are simplicity, precision, repeatability, and speed (improving several traits simultaneously). All the steps and the analysis of the results are explained step by step in a case study.

Bean breeding programs have focused on the generation of early bush cultivars with higher yields, commercial acceptance and resistance to crop-limiting diseases. This study prioritized the nutritional quality in terms of iron (Fe) and zinc (Zn) content in bean grains grown in three high tropical environments. Two bush bean cultivars and five climbing bean cultivars were evaluated. The mineral content of the grains was determined with atomic absorption spectroscopy. The results indicated that the bush genotypes Bacatá and Bianca are biofortified with Fe and Zn and the climbing cultivar Sutagao is biofortified with Zn. Statistical differences were found between genotypes (G), environments (E) and GxE interactions. According to the AMMI stability value (ASV), the cultivars Sutagao, Bianca and Iraca were stable, whereas Bacatá, which was the one with the highest nutritional quality, was moderately stable. The Simijaca environment showed an adequate edaphic contribution to bean production with nutritional quality. [ABSTRACT FROM AUTHOR]

Alfalfa (Medicago sativa L.) is used to support livestock. A stability study was carried out over three years. The stability indices for yield and main quality characteristics such as plant height, number of nodes, the yield of green mass and dry matter, crude protein and fiber (%), and ash (%), were examined. Statistical analysis revealed significant differences that indicated the presence of high genotype–year interactions. Heritability was higher in the case of qualitative traits than quantitative traits. The most intriguing correlation was between green mass yield and crude protein content because positive correlations may lead to indirect and simultaneous selection. According to the statistical biplot models AMMI and GGE, the best genotypes for almost all traits to use, regardless of the environment and cultivation type, were the G8 (Population 2) followed by cultivar G3 (Yliki). Despite the high index values shown by the parameter number of nodes, the latter and yield showed low heritability.

Sounding rockets constitute a class of rocket with a generally simple layout, being composed of a cylindrical center-body, a nosecone, a number of fins placed symmetrically around the longitudinal axis (usually three or four), and possibly a boat-tail. This type of flying craft is typically not actively controlled; instead, a passive stabilization effect is obtained through suitable positioning and sizing of the fins. Therefore, in the context of dynamic performance analysis, the margin of static stability is an index of primary interest. However, the classical approach to static stability analysis, which consists in splitting computations in two decoupled domains, namely, around the pitch and yaw axis, provides a very limited insight to the missile performance for this type of vehicle due to the violation of the classical assumptions of planar symmetry and symmetric flight conditions commonly adopted for winged aircraft. To tackle this issue, this paper introduces a method for analyzing static stability through a novel index, capable of more generally assessing the level of static stability for sounding rockets, exploiting the same information on aerodynamic coefficients typically required for more usual (i.e., decoupled) static stability analyses, and suggests a way to assess the validity and shortcoming of the method in each case at hand.

Background: Selection is one of the essential skills whereby breeders reduce the population size and increase the chance of success. Various selection methods with special applications have been developed. Superior genotypes are assessed according to interesting traits, including univariate, multivariate, phenotypic, genotypic, etc. Methods: Mathematical calculation of the traits' importance based on the genetic makeup of investigated population (average degree of dominance/additive involved in the action of genes) and arbitrary genetic parameters is functional. In this paper, a general model for multivariate selection has been presented whereby the selection can be made for (a) more than one interesting trait, (b) the trait(s) with complex inheritance, (c) finding superior genotypes from among a large-scale population, (d) finding superior genotypes in segregating generations and (f) finding tolerant genotypes to stresses. This model is developed based on biometric concepts in four steps. MATLAB script is provided for the model, and users can easily apply that to identify the most suitable genotypes after data collection according to the breeding purposes. Results: The main features of this model are simplicity, precision, repeatability, and speed (improving several traits simultaneously). All the steps and the analysis of the results are explained step by step in a case study. [ABSTRACT FROM AUTHOR]

Additive main effects and multiplicative interaction (AMMI), as well as various AMMI-derived statistics, Genotype, and Genotype × Environment Interaction (GGE) models were employed on 24 sugarcane genotypes planted during two seasons (2017–18, 2018–19) under different induced salinity stress environments using saline water irrigation (iw) viz., E1 (Normal iw during crop season 2017–18), E2 (Normal iw during crop season 2018–19), E3 (4 dsm−1 ECiw during crop season 2017–18), E4 (4 dsm−1 ECiw during crop season 2018–19), E5 (8 dsm−1 ECiw during crop season 2017–18), E6 (8 dsm−1 ECiw during crop season 2018–19), E7 (12 dsm−1 ECiw during crop season 2017–18) and E8 (12 dsm−1 ECiw during crop season 2018–19) to assess the genotype by the environment interaction for the cane yield, commercial cane sugar (CCS) yield, number of millable cane (NMC), single cane weight (SCW), and pol % in juice. Individual and interactive effects of the genotype and environment for all the traits were significant. In the expression of total variability, the environmental contribution was higher for the cane yield (66.98%), CCS yield (67.60%), NMC (65.78%), and SCW (43.27%), whereas genotypic contribution was higher in the expression of pol% (82.48%). As per AMMI Stability Value (ASV), G14 (Co 13033), G23 (Co 15026), G7 (Co 05009), G17 (Co 13036), and G2 (Co 15025) were the most stable genotypes for the cane yield. Whereas as per GSI (genotype selection index), genotypes G24 (Co 15027), G21 (Co 15023), G23 (Co 15026), and G17 (Co 13036) were found most stable. The Sustainability Index (SI) of the cane yield (CY) and its contributing and CY-based computed traits were low for most of the genotypes, which indicates the negative impact of increased levels of irrigation-induced salinity in the expression of these traits. In the mean vs stability biplot analysis, G21 (Co 15023), G24 (Co 15027), G16 (Co 13036), G6 (Co 0238), and G20 (Co 14036) were found to be highly productive and stable genotypes for the cane yield. The superior and stable performance of early maturing notified varieties G21 (Co 15023) and G6 (Co 0238) for CY and CCS yield indicates that they will help the farmers to obtain sustainable income in saline soil conditions. [ABSTRACT FROM AUTHOR]

The use of grazing management strategies can influence canopy structure and the permanence of legumes. The objective of this work was to evaluate the determination of forage canopy heights as a grazing management strategy regarding herbage mass composition and tiller population dynamics in multispecies pastures comprising Megathyrsus maximus cv. Aruana and the legumes Macrotyloma axillare, Calopogonium mucunoides and Stylosanthes spp. Four treatments, defined by canopy heights of 15, 30, 45 and 60 cm, were evaluated in a randomised block design with four replications. The evaluations were performed under continuous stocking with sheep. Taller pastures (45 and 60 cm) contained greater (P < 0.05) total herbage mass of Aruana leaves and stems and also higher mass of legumes than smaller pastures (15 and 30 cm). The grass tiller population density was different between heights (P < 0.05) of 2.71, 2.02, 1.97 and 1.47 tillers/m2 for heights of 15, 30, 45 and 60 cm, respectively. The tiller appearance rate was highest in tall pastures (P < 0.05) and the lowest rate and stability index were found in 15 cm pastures. Aruana guineagrass and forage legumes can be managed in the height range of 30–60 cm under continuous stocking. [ABSTRACT FROM AUTHOR]

Introduction: The variability in the structure of aquatic communities is frequently attributed to environmental changes; however, in stable environments such as regulated rivers, trophic interactions could be another key environmental factor determining the structure of these communities. These alterations could cause a greater growth of algae, and in turn, changes in the functional groups and in the composition of the macroinvertebrate community favoring the dominance of certain groups of organisms. Objective: To identify the effects of environmental variations and changes in the structure of the phycoperiphyton on the macroinvertebrate community of regulated Andean rivers. Methods: We analyzed environmental and biological data collected in quarterly samples carried out between 2010 and 2018 in two rivers of the Central Andes (Antioquia - Colombia), for a total of 27 samples. Sample collections used standardized methods. Different statistical models were used to establish spatial and temporal patterns of the environmental variables, of the abundance and/or density and diversity of phycoperiphyton and macroinvertebrates, as well as the trophic relationships that exists between them. Results: We found that regulated rivers present relatively little environmental variability. The environmental parameters with the greatest variation were temperature, turbidity, and orthophosphates; these last two were the abiotic variables with the greatest contribution to benthic instability. Conclusion: The presence of scraping and foraging macroinvertebrates was more affected by the stability of the phycoperiphyton density than by environmental variables, showing the importance of trophic interactions in regulated rivers and the bottom up control in these ecosystems. [ABSTRACT FROM AUTHOR]

Faba beans are considered one of the most important crops for animal feed. The genotype × environment interaction (GEI) has a considerable effect on faba bean seed production. The objectives of this study included assessing multiple locations and genotypes to understand how various ecosystems and faba bean genotypes relate to one another, and suggesting the ideal climatic conditions, crop management system, and genotypes so that they are carefully chosen for their stability. A 2-year experiment was conducted in order to define the stability across four environments based on stability indices for certain characteristics: moisture (%), ash content (%), crude protein content (%), crude fat (%), total starch (%), and crude fiber content (%). Statistically significant differences indicated that GEIs were present. The heritability was generally high for qualitative traits in comparison with quantitative traits. The crude protein content, plant height, and thousand-seed weight were all positively correlated with the seed yield; however, the other qualitative variables were adversely correlated. The crude protein content of the cultivar Tanagra displayed a high stability index, followed by Ste1. Under conventional management, Tanagra demonstrated high values for the seed yield in Giannitsa and Florina. Ste1 and Ste2 are particularly promising genetic materials that showed high values under low-input conditions. The best genotypes to use and the most favorable environments/types of cultivation were the Tanagra cultivar, followed by the Ste2 genotype, according to the additive main effects and multiplicative interaction (AMMI) and genotype plus genotype-by-environment (GGE) biplot models. Earliness showed significant heritability values and very high stability indices, again indicating qualitative behavior according to genetic parameters. With the exception of the number of pods per plant, which demonstrated low heritability while having excellent index values, traits like seed yield showed relatively low-stability-based heritability values. Global efforts aimed at improving the genetics of faba beans might benefit from genotypes that exhibit consistent yields in various conditions.

In this paper, basing on the theory of matricial Hamburger moment problems, we establish the intrinsic connections between the quasi-stability of a monic or comonic matrix polynomial and the Stieltjes property of a rational matrix-valued function built from the even–odd split of the original matrix polynomial. As applications of these connections, we obtain some new criteria for quasi-stable matrix polynomials and Hurwitz stable matrix polynomials, respectively. [ABSTRACT FROM AUTHOR]

Digital technologies are currently one of the main engines of growth and technological development of the global economy. The introduction of digital technologies contributes to the competitiveness of various sectors of the world economy, the creation of new business opportunities in terms of connecting to digital global value chains, the emergence of new markets and niches, and the accelerated introduction of new digital goods into the global market. The digitalization process does not happen simultaneously in different countries of the world, so there is a certain gap in the degree of digitalization of national economies, which gives rise to digital inequality and, as a consequence, increasing the dependence of countries on developed countries. Politics, legal norms, traditions and culture, the level of economic development achieved, the level of education, and the country's own technological base, as well as many other factors, play an important role in the digital transformation of a country's economy. As a result of the digital transformation of the global economic architecture, new contours of the digital economy are emerging, characterized by the exponential growth of data flows. The formation of the digital market space contributes to increasing competitiveness primarily in the industrial sector through the creation of new products and their service system, which leads to the emergence of new market segments. In other words, the digital market, in fact, is a modern mechanism providing a rapid transition from national markets limited by state borders to a single global market. This situation requires a study of the economic aspects of digitalization in the context of sustainable development of our state, which determines the relevance of the chosen research topic. The purpose of the article is to assess the impact of digitalization on the economy through the example of Ukraine and its directions in peacetime and under martial law. Assessment of digitalization and its impact on the economy was carried out on the basis of open data, in particular GDP per capita, indexes of global and digital competitiveness, digital induction, and sustainability index were used. During the study, the following scientific methods were used: analysis and synthesis, the method of establishing cause-effect relationships, and graphical methods. As a result of the study, the main trends in the digitalization of the national economy and its risks were identified, focusing on the shift in emphasis from service to military goals of digital transformation. A conclusion was made about a significant breakthrough in the digital economy in Ukraine and further development regardless of russia's military invasion of Ukraine. The state of Ukraine was analyzed with the help of digitalization indices and the confirmation of the need for further monitoring of the digitalization of the Ukrainian economy and the study of its impact on the rate of economic growth was identified on their basis. [ABSTRACT FROM AUTHOR]

Objective: To explore the biomechanical factors affecting the stability of athletes in the 143D balance phase of competitive Tai Chi., Method: The Vicon 3D motion capture system, Kistler 3D force platform, and Noraxon surface electromyography (sEMG) system were used to measure the joint angle, joint moment, center of gravity, ground reaction force, and sEMG data of athletes. The stability index was then calculated according to the formula. Pearson's or Spearman's correlation tests were used to analyze the associations between the biomechanical factors and stability index., Results: (1) Medial lateral stability index (MLSI): A significant negative correlation was found between the ankle inversion angle of the supporting leg (SL) and MLSI ( p < 0.05). (2) Anterior posterior stability index (APSI): Significant negative correlations were observed between the ankle intorsion angle, integrated electromyography (iEMG) of the gastrocnemius, and muscle contribution rates of the tibialis anterior, external oblique, and gastrocnemius of the non-supporting leg (NL) with the APSI ( p < 0.05). The ankle dorsiflexion moment, iEMG of the rectus femoris and tibialis anterior, muscle contribution rate of the biceps femoris, and root mean-squared (RMS) amplitude of the gluteus maximus of the SL also showed significant negative correlations with the APSI ( p < 0.05). Strong and significant negative correlations were also identified between the hip intorsion angle, iEMG of the tibialis anterior, and RMS amplitude of the rectus femoris of the NL with the APSI ( p < 0.01). Further strong and significant negative correlation was also found between the RMS amplitude of the biceps femoris of the SL and APSI ( p < 0.01). The knee extorsion angle of the NL was positively correlated with the APSI ( p < 0.05). (3) Dynamic postural stability index (DPSI): The knee adduction angle, iEMG of the tibialis anterior, and RMS amplitude of the erector spinae of the NL were significantly positively correlated with the DPSI ( p < 0.05). The knee abduction and hip extension moments of the SL were also significantly positively correlated with the DPSI ( p < 0.05)., Conclusion: The ankle inversion angle of the SL impacts left-right stability, while the NL's hip and ankle intorsion angles, knee extorsion angle, and exertion on the core muscle and SL's main muscles, as well as exertion of specific muscles of the NL affect anterior-posterior stability. The hip extension and knee abduction moments of the SL, knee adduction angle, exertion on the tibialis anterior, and activation of the erector spinae of the NL significantly affect the overall stability of an athlete., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Huang, Ma, Lin, Zheng, Liu and Jia.)

ABSTRACT This work was conducted to evaluate the effect of deferred pasture condition of Brachiaria brizantha cv. Marandu in the late winter on tillering during the growing season. The treatments were three pasture conditions at late winter: short pasture, tall pasture and tall/mown pasture. In September and October, tiller appearance rate (TApR) and tiller mortality rate (TMoR) were greater in the tall/mown pasture. In November and December, tall pasture presented greater TApR. From November to January the TMoR was greater in the tall pasture. The tiller stability index of short and tall/mown pastures were greater in October. The short pasture presented a greater tiller number than the tall and tall/mown pastures during the entire experimental period. Deferred and short pasture of marandu palisade grass at late winter presents in general lower tiller mortality and higher population density of tillers from the early spring onwards, in comparison to tall pasture. The mowing of marandu palisade grass with high forage mass at the late winter, although it only temporarily compromises the population stability of tillers, also stimulates its fast tillering from spring on.

IMO stability regulations include various stability parameters such as GM values. To assess the stability of the ships, we should check all stability parameters of the IMO requirements. However, since this process is complex, a more convenient way to evaluate stability performance is required. In this research, the index for marine ship intact stability assessment (IMSISA) model was developed to solve these problems. The IMSISA model consists of a stability index calculation module and a stability assessment module. In the stability index calculation module, ten stability parameters, including GM, were used to develop the stability index, which has the advantage of being able to quantify the ship stability. The stability assessment module uses the stability index value to determine the stability status of the ship and provides the captain with stability management guidelines. To verify the proposed model, the basic stability calculations were performed for two model ships in 32 loading situations. The proposed model was found to provide better performance in the stability assessment than the previous study. By applying the IMSISA model to the ships, the captain can assess the ship stability more quantitatively and efficiently.

Background: The stability index estimation algorithm was derived and applied to develop and implement a balance ability diagnosis system that can be used in daily life. Methods: The system integrated an approach based on sensory function interaction, called the clinical test of sensory interaction with balance. A capacitance and resistance sensing type force mat was fabricated, and a stability index prediction algorithm was developed and applied using the center of pressure variables. The stability index prediction algorithm derived a center of pressure variable for 103 elderly people by Nintendo Wii Balance Board to predict the stability index of the balance system (Biodex SD), and the accuracy of this approach was confirmed. Results: As a result of testing with the test set, the linear regression model confirmed that the r-value ranged between 0.943 and 0.983. To confirm the similarity between the WBB and the flexible force mat, each measured center of pressure value was inputted and calculated in the developed regression model, and the result of the correlation coefficient validation confirmed an r-value of 0.96. Conclusion: The system developed in this study will be applicable to daily life in the home in the form of a floor mat.

This study proposes an under-frequency load-shedding (UFLS) scheme based on a binary Archimedes Optimization Algorithm (BAOA) and the Weighted Sum Method (WSM) to maintain the stability of an islanded distribution system. These methods consider stability indices and load priorities to ensure effective load shedding during frequency deviations. The BAOA determines the optimal load shedding based on the stability index and power mismatch that minimizes the impact on critical loads while maintaining system stability in an islanded distribution system. The WSM determines the rank of the load to be shed based on four criteria: the load priority, the load category, the stability index, and the load size. Each load is assigned a weight based on its priority. These weight variables determine the order in which loads are shed during frequency deviations. The effectiveness of the proposed UFLS was tested on an 11 kV Malaysian distribution network with two mini hydro distributed generation systems. A comparative study was conducted based on five result outputs, including the number of loads shed, the size of the loads shed, the frequency undershoot, the frequency overshoot, and the time taken to achieve a stable frequency in three cases: base load, peak load, and peak load with photovoltaics (PV). The proposed UFLS showed the best results for 11 of 15 outputs (73.3%) for islanding events and 9 of 15 outputs (60%) for overloading events. The voltage profile and stability index, also, were improved after the proposed UFLS was applied.

High salt concentration in irrigation water is often a limiting factor to tomato production in Brazil. However, there is limited information available regarding the tolerance of tomato genotypes to saline irrigation. An experiment was conducted in a protected environment using a randomized block design with four replications. Treatments consisted of 12 tomato genotypes cultivated in an environment with varying levels of salt stress. Moderate and severe salt stress affected plant height, transversal and longitudinal diameter of fruit, fresh mass, yield, and number of tomato fruit per plant. Cluster analysis, stability, and adaptability provided the best estimates to identify the most adaptable genotype to saline stress, with the genotypes Maestrina, Onix, Pizzadoro, and Shanty being the best adapted to moderate and severe saline stress conditions. The genotypes Maestrina, Onix, Pizzadoro, and Shanty were identified as most adaptable to and stable under salt stress. Sodium absorption increased as irrigation salinity increased. In addition, P, K, and Ca concentration decreased under salt stress, which caused damage to all yield components and plant nutrition. The genotype Onix was more tolerant to the effects of moderate saline irrigation, while the genotypes Sheena, Sperare, Santa Clara, IPA 6, and Dominador had lower losses under severe salt stress conditions. [ABSTRACT FROM AUTHOR]

Khaled Hosny,1– 3 Hani Asfour,4 Waleed Rizg,1– 3 Nabil A Alhakamy,1– 3 Amal Sindi,5 Hala Alkhalidi,6 Walaa Abualsunun,1 Rana Bakhaidar,1 Alshaimaa M Almehmady,1 Sara Akeel,5 Sarah Ali,5 Adel Alghaith,7 Sultan Alshehri,7 Rasha Khallaf8 1Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 2Center of Excellence for Drug Research and Pharmaceutical Industries, King Abdulaziz University, Jeddah, 21589, Saudi Arabia; 3Advanced Drug Delivery Research Group, Faculty of Pharmacy, King Abdulaziz University, Jeddah, 21589, Saudi Arabia; 4Department of Medical Microbiology and Parasitology, Faculty of Medicine, King Abdulaziz University, Jeddah, 21589, Saudi Arabia; 5Oral diagnostic sciences department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; 6Department of Clinical pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 7Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia; 8Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, 62511, EgyptCorrespondence: Khaled HosnyDepartment of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi ArabiaTel +966 561682377Email elswaify2000@yahoo.com; kmhomar@kau.edu.saIntroduction: Natural oil-based nanoemulsions (NEs) have been widely investigated in many diseases that affect the oral cavity. NEs are delivery systems that enhance the solubility of lipid therapeutics and improve their delivery to target sites; they are known as self-nanoemulsifying drug delivery systems (SNEDDSs). The current investigation’s aim was to produce an oregano essential oil-based nanoemulsion (OEO-SNEDD) that would have antibacterial and antifungal effects against oral microbiota and improve oral health.Methods: Several OEO-SNEDDSs were developed using different percentages of OEO (10%, 14%, and 18%), percentages of a surfactant mixture Pluracare L64:Lauroglycol FCC (18%, 32%, and 36%), Smix ratios (1:2, 1:1, and 2:1), and hydrophilic-lipophilic balances (HLBs) of the surfactant mixture (8, 10, and 12) using the Box‒Behnken design. The optimized concentration of excipients was determined using a pseudoternary phase diagram to obtain the NEs. The formulations were evaluated for their droplet size, stability index, and antibacterial and antifungal activities.Results: The NEs had a droplet size of 150 to 500 nm and stability index of 47% to 95%, and the produced formulation reached antibacterial and antifungal inhibition zones of up to 19 and 17 mm, respectively. The Box‒Behnken design was adopted to get the optimum formulation, which was 18% OEO, 36% Smix, 10.29 HLB of Smix, and a 1.25:1 Smix ratio. The optimized formulation had a lower ulcer index compared with various other formulations evaluated in rats.Conclusion: This study illustrated that OEO-SNEDDSs can provide good protection against oral microbial infections.Keywords: oregano essential oil, nanoemulsion, Box‒Behnken design, ulcer index, required HLB, carvacrol, thymol, stability index

Yuki Nishi,1,2 Hayato Shigetoh,1 Ren Fujii,1 Michihiro Osumi,1,3 Shu Morioka1,3 1Department of Neurorehabilitation, Graduate School of Health Science, Kio University, Nara, Japan; 2Department of Rehabilitation Medicine, Nishiyamato Rehabilitation Hospital, Nara, Japan; 3Neurorehabilitation Research Center, Kio University, Nara, JapanCorrespondence: Yuki NishiDepartment of Neurorehabilitation, Graduate School of Health Science, Kio University, 4-2-2 Umaminaka, Koryo-cho, Kitakatsuragi-gun, Nara, 635-0832, JapanTel +81-74-554-1601Fax +81-74-554-1600Email y.nishi.pt@gmail.comBackground: Individuals with chronic low back pain (CLBP) experience changes in gait control due to pain and/or fear. Although CLBP patients’ gait has been performed in laboratory environments, changes in gait control as an adaptation to unstructured daily living environments may be more pronounced than the corresponding changes in laboratory environments. We investigated the impacts of the environment and pathology on the trunk variability and stability of gait in CLBP patients.Methods: CLBP patients (n=20) and healthy controls with no low-back pain history (n=20) were tasked with walking in a laboratory or daily-living environment while wearing an accelerometer on the low back. We calculated the stride-to-stride standard deviation and multiscale sample entropy as indices of “gait variability” and the maximum Lyapunov exponent as an index of “gait stability” in both the anterior-posterior and medial-lateral directions. The participants were assessed on the numerical rating scale for pain intensity, the Tampa Scale for Kinesiophobia, and the Roland–Morris Disability Questionnaire for quality of life (QOL).Results: In a repeated-measures ANOVA, the standard deviation was affected by environment in the anterior-posterior direction and by group and environment in the medial-lateral direction. Multiscale sample entropy showed no effect in the anterior-posterior direction and showed both effects in the medial-lateral direction. Maximum Lyapunov exponents showed both effects in the anterior-posterior direction, but none in the medial-lateral direction. These changes of trunk motor control by CLBP patients were found to be related to pain intensity, fear of movement, and/or QOL in the daily-living environment but not in the laboratory environment.Conclusion: These results revealed that CLBP patients exhibit changes in trunk variability and stability of gait depending on the environment, and they demonstrated that these changes are related to pain, fear, and QOL. We propose useful accelerometer-based assessments of qualitative gait in CLBP patients’ daily lives, as it would provide information not available in a general practice setting.Keywords: chronic low back pain, daily-living gait, variability index, stability index, inertial sensor

Intact stability represents one of the most important topics when addressing ship safety, and it is ruled by the IMO Intact Stability code, evaluating ship stability in a calm water scenario. However, the interest in ship stability in waves has increased in recent years and this has led to the formulation of the second generation intact stability criteria (SGISc), finalized at IMO in 2020. In this research, an approach to quantitatively and comprehensively evaluate the ship stability performance in waves has been pursued. A methodology is developed with reference to the SGISc. The intact stability in waves index (ISWI) has been proposed, with the aim to become a complementary tool for designers and shipbuilders in the assessment of stability performance in waves. The ISWI represents a comprehensive stability index, able to capture the stability in waves performance of a vessel. The stability index has been verified on a set of megayacht units and its sensitivity to the wave characteristics has been tested, changing the environmental conditions. The outcomes point to a good agreement between the ISWI and the influence of environmental condition changes on the stability performance.

Given a homogeneous linear discrete or continuous dynamical system, its stability index is given by the dimension of the stable manifold of the zero solution. In particular, for the $n$ dimensional case, the zero solution is globally asymptotically stable if and only if this stability index is $n.$ Fixed $n,$ let $X$ be the random variable that assigns to each linear random dynamical system its stability index, and let $p_k$ with $k=0,1,\ldots,n,$ denote the probabilities that $P(X=k)$. In this paper we obtain either the exact values $p_k,$ or their estimations by combining the Monte Carlo method with a least square approach that uses some affine relations among the values $p_k,k=0,1,\ldots,n.$ The particular case of $n$-order homogeneous linear random differential or difference equations is also studied in detail.

The article shows the procedure for determining the values of the stability index of hydraulic structures (earth dams). An approach to the creation of an engineering methodology for carrying out operational calculations for predicting the state of an earth dam under the influence of known characteristics of damaging factors of rapidly developing dangerous natural phenomena and man-made processes is presented. One of the directions of application of the proposed approach is shown — the definition of rational parameters for the protection of hydraulic structures and the development of a plan of measures to achieve them.

In Venezuela, sugarcane is grown in distinct environments, including soil categories and cultural practices. This research aimed to identify high-yield and stable sugarcane (Saccharum spp., hybrid) genotypes using selection indices. The experimental material consisted of sixteen genotypes and two commercial varieties as control. The genotypes were evaluated in five locations and by two harvest cycles. The yield in Ton Pol per hectare (TPH) was subjected to an analysis of variance according to the AMMI model. Methodologies of adaptability, stability, and indices that combine both stability and yield were determined. It was possible to distinguish the indices in three groups in the biplot. The superiority index (Pi), geometric adaptability index (GEI), and reliability index (Ii) were located in group 1 (G1). This group coincided in classifying genotypes CR87-339, C323-68, and V98-76 as the most stable and the best yield. The second group (G2) consisted of Kang's rank-sum (RS), Stability index (I), Sustainability index (SI), and geometric adaptability index (GDI) and located the genotypes CR87-339 and C323-68 as the most desired. The third group (G3) was constituted by the Ecovalence statistics (W), Shukla’s unbiased stability variance (σ2i) and the AMMI value (ASV) and classified the genotypes CP87-1762, V90-6 and CP 92-1641 as the best. The indices that best discriminated the genotypes and most associated with yield were PI, GAI and Ii.

ABSTRACT This study was carried out to evaluate the effect of nitrogen fertilization on tillering dynamics of Alexandergrass (Urochloa plantaginea (Link) Hitch) grazed by beef heifers in a rotational stocking grazing method. The experiment was conducted in a completely randomized design following a repeated measure arrangement, three levels of nitrogen (Zero, 150 and 300kg ha-1) and two area repetition. The classification of tillers into categories (basal and axillary) showed a greater number of basal tillers, due to their higher appearance rate, in the absence of nitrogen fertilization. Nitrogen fertilization promoted higher axillary tiller density. The use of nitrogen promotes the renewal of axillary tillers of Alexandergrass, without compromising the stability of the tiller population.

Yacon (Smallanthus sonchifolius) is a tuber with a high content of active compounds that offer health benefits, so its productive chain seeks new alternatives to generate yacon products with added value; however, it tends to be a perishable product due to its high aw, chemical composition, and enzymatic activity. The influence of both composition and homogenization in the colloidal stability of yacon suspensions was evaluated for later use in spray drying. Response surface methodology and a central composite design were used, considering three independent variables: homogenization time (TH) (4-6 min), xanthan gum (XG) (0.1-0.2%), and acidity (0.1-0.3%); and the following dependent variables: zeta potential (ζ), color (CIELab), viscosity (μ), stability index by spectral absorption (R), and particle size (D10, D50, and D90). The values of the independent variables that best fit the experimental optimization criteria were: XG=0.16%, acid=0.3%, and TH=4.8 min. The values of the experimental dependent variables and the variables predicted by the quadratic model were ζ=-33.8±4.0 and -37.6 mV, µ=1143.0±93.4 and 1000 cP, R=0.45±0.1 and 0.48, D10=127.8±8.2 and 138.1 µm, D50=251.2±16.3 and 267.7 µm, D90=424.3±28.7 mm and 463.9 µm, L*=41.7±1.4 and 41.8, a*=0.02±0.85 and 1.6, and b*=15.0±1.3 and 14.8, respectively. The colloidal suspension showed adequate physicochemical stability, favored mainly by repulsive forces, homogenization, and rheology of the continuous phase; reaching a content of total solids of 12.5%.

Nitrogen fertilization can increase the appearance of new tillers, which can improve the structure of deferred sward, since the deferral period is not long. Thus, the objective of this study was to estimate the effects of nitrogen fertilization on structure and tillering dynamics of Piata palisade grass (Brachiaria brizantha cv. Piata) during deferment. We evaluated three nitrogen fertilization levels (none - 0 kg ha -1; medium - 75 kg ha -1; and high - 150 kg ha -1) associated with deferment periods (1, 30, 60, 90, and 120 days). The experimental design was set in completely randomised blocks in a split-plot arrangement, with three replications. The deferment period influenced foliage area index quadratically (p < 0.01) at all fertilization levels. The improvement in nitrogen fertilization levels increased light interception and reduced the foliage angle, but it did not affect tillering dynamics of Piata palisade grass during the deferment period. Appearance and mortality rates, the balance between tiller appearance and mortality and the stability index of the population of aerial and basal tillers of Piata palisade grass were higher at the beginning of the pasture deferment period. Nitrogen fertilization does not stimulate appearance of tillers on deferred Piata palisade grass. Tiller population stability, however, is only high at the beginning of deferment, decreasing after this initial period.

High-voltage direct current (HVDC) transmission is playing an increasingly important role in modern power systems, and the resulted power/voltage stability issue has raised widespread concern. This paper presents an on-line power/voltage stability index (PVSI) for multi-in-feed HVDC (MIDC) systems. Different from the existing indices which are developed mainly for off-line and static analysis, the proposed PVSI can be applied in real time. Effects of system changes on stability assessment such as change of system states and control strategies are considered. Thus, helpful guidance can be provided for on-line HVDC stability and controls. The PVSI is originally deduced for single-infeed HVDC systems in an “AC way” by analyzing the power and voltage stability of both pure AC systems and HVDC systems. Moreover, its on-line application in practical MIDC systems is realized by building an equivalent single-infeed model, and utilizing nowadays measurement and communication infrastructures such as wide-area measurement system (WAMS). The effectiveness of the PVSI is verified through simulations in real-time digital simulator (RTDS).

Abstract The reactive power losses caused by the power grid Geomagnetically Induced Current (GIC) severely disturb the static voltage stability of power systems, and may even trigger voltage collapses. In this paper, the 1 V/km uniform induced geoelectric field is adopted to analyze how greatly geomagnetic disturbance (GMD) can influence the static voltage stability of power systems, given the features of GMD disasters hitting the power grids of China. Considering the GIC reactive power losses, a method that combines second‐order sensitivity adaptive variable step size and local curve fitting is put forth to calculate the critical point of the active power and voltage nodes (PV) curve. With the increment ratio of the curve slope set at discretion, the method enables the curve to approach its critical point with great strides, a design managing to reduce the quantity of power flow calculations remarkably. By taking into account the reactive power violation of PV nodes in the acquisition of load increment step size, the method calculates the critical point of the PV curve in a much more accurate way. The method applied to the Northwest 750 kV power grid, the calculation results suggest that the 1 V/km induced geoelectric field markedly undermines the static voltage stability, thus posing grave threats to the above grid.

Understanding rhythmic behavior in the context of coupled auditory and motor systems has been of interest to neurological rehabilitation, in particular, to facilitate walking. Recent work based on behavioral measures revealed an entrainment effect of auditory rhythms on motor rhythms. In this study, we propose a method to compute the neural component of such a process from an electroencephalographic (EEG) signal. A simple auditory-motor synchronization paradigm was used, where 28 healthy participants were instructed to synchronize their finger-tapping with a metronome. The computation of the neural outcome measure was carried out in two blocks. In the first block, we used Generalized Eigendecomposition (GED) to reduce the data dimensionality to the component which maximally entrained to the metronome frequency. The scalp topography pointed at brain activity over contralateral sensorimotor regions. In the second block, we computed instantaneous frequency from the analytic signal of the extracted component. This returned a time-varying measure of frequency fluctuations, whose standard deviation provided our " stability index " as a neural outcome measure of auditory-motor coupling. Finally, the proposed neural measure was validated by conducting a correlation analysis with a set of behavioral outcomes from the synchronization task: resultant vector length, relative phase angle, mean asynchrony, and tempo matching. Significant moderate negative correlations were found with the first three measures, suggesting that the stability index provided a quantifiable neural outcome measure of entrainment, with selectivity towards phase-correction mechanisms. We address further adoption of the proposed approach, especially with populations where sensorimotor abilities are compromised by an underlying pathological condition. The impact of using stability index can potentially be used as an outcome measure to assess rehabilitation protocols, and possibly provide further insight into neuropathological models of auditory-motor coupling. [ABSTRACT FROM AUTHOR]