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Aim: Marine biodiversity faces unprecedented threats from anthropogenic climate change. Ecosystem responses to climate change have exhibited substantial variability in the direction and magnitude of redistribution, posing challenges for developing effective climate-adaptive marine management strategies. Location: The California Current Ecosystem (CCE), USA. Methods: We project suitable habitat for 10 highly migratory species in the California Current System using an ensemble of three high-resolution (~10 km) downscaled ocean projections under the Representative Concentration Pathway 8.5 (RCP8.5). Spanning the period from 1980 to 2100, our analysis focuses on assessing the direction and distance of distributional shifts, as well as changes in core habitat area for each species. Results: Our findings reveal a divergent response among species to climate impacts. Specifically, four species were projected to undergo significant poleward shifts exceeding 100 km, and gain habitat (~7%–60%) in response to climate change. Conversely, six species were projected to shift towards the coast, resulting in a loss of habitat ranging from 10% to 66% by the end of the century. These divergent responses could typically be characterized by the mode of thermoregulation (i.e. ectotherm vs. endotherm) and species' affiliations with cool and productive upwelled waters that are characteristic of the region. Furthermore, our study highlights an increase in niche overlap between protected species and those targeted by fisheries, which may lead to increased human interaction events under climate change. Main Conclusions: By providing valuable species distribution projections, our research contributes to the understanding of climate change effects on marine biodiversity and offers critical insight and support for developing climate-ready management of protected and fished species.

In this paper, an on-line closed-loop identification of mainly mass and inertia of an under-actuated aerial vehicle, namely a quadrotor acting as an aerial manipulator, is presented. Being treated as a rigid body, only one set of eighteen- or six tri-axial linear accelerometers is used to facilitate such estimation. Force and torque disturbances acting upon the vehicle during identification are also estimated which will refine the overall estimation quality of the unknown parameters. Namely, recursive linear and nonlinear least squares methods are used to obtain initial and refined estimations, respectively. Random disturbances are introduced to the closed-loop system to ensure enough excitation of the overall system. Issues related to identifiability, stability and performance are discussed. Since the proposed method depends on general kinematical and dynamical analyses of motion, it is claimed that the presented method will be also applicable to a wider range of, mainly, aerial vehicles. [ABSTRACT FROM AUTHOR]

Accurate accident reconstruction requires the knowledge of the mass properties of vehicles, namely the centre of gravity location, the mass and the inertia tensor. Such data are seldom available, especially in case of newly produced electric vehicles. In this paper, vehicle inertia measurements, performed at Politecnico di Milano, refer to a number of electric vehicles. In addition to the "simple" measurement of vehicle inertia, measured mass properties are analysed to derive the proper empirical formulae for the estimation of the centre of gravity height and the moments of inertia. Both internal combustion and electric vehicles are considered. Data show a significant difference in the mass properties of the two types of vehicles. The proposed formulae can be effectively employed to quickly obtain a reasonable estimation of the mass properties of any vehicle. The results show that electric vehicles are characterised by higher values of mass with respect to internal combustion vehicles, but they present a lower centre of gravity location and proportionally lower values of the moments of inertia. [ABSTRACT FROM AUTHOR]

Problem: Participating in professional sport involves constant travel. From a review of the literature, the issue of transport in sport (passenger transport) in generating a carbon footprint has already been noted. A reliable assessment of the scale of this phenomenon is currently underway. The aim of this article is to assess the carbon footprint of transporting football players to away matches. It is complemented by a proposal to change the way matches are played using the Sports Centre concept. Methods: A systematic literature review was carried out in the theoretical part. The research part was conducted based on EN 16258 and the centre of gravity method. The objects of this study are five selected football clubs from the Polish Ekstraklasa, and their method of travel (by coach) to away matches. Results: The use of alternative (low-carbon) modes of transport reduces GHG levels from 13 per cent (Pogoń Szczecin) to 34 per cent (Jagiellonia Białystok). An interesting solution, although not yet adapted to the current times, is the implementation of the Sports Centre concept, which allows a 48 per cent reduction in the distance travelled (81,940 kgCO2e per year). Conclusions: Football clubs can neutralise their remaining carbon footprint through investments that indirectly contribute to total carbon neutrality, such as the planting of oxygen trees or the installation of a photovoltaic system to completely neutralise the carbon footprint. [ABSTRACT FROM AUTHOR]

Modern commentators have doubts about the authenticity and cogency of the early propositions of Archimedes’ On Equilibrium of Planes Book 1. Ernst Mach famously said that the proof of Prop. 6, the so-called law of the lever, assumes what is to be proven. Comparing the initial text in Heiberg’s modern edition (1881, 1913) to the first propositions in Eutocius’ commentary on EP 1, J. L. Berggren ([1976]. ‘Spurious Theorems in Archimedes’ Equilibrium of Planes: Book I’, Archive for History of Exact Sciences 16.2 (1976), 87–103.) claimed that the propositions up through Proposition 3 of the standard modern edition are schoolbook additions written by an ancient author inferior to Archimedes. The present paper argues for the logical connectedness of Postulates 1–5 to Props. 1–6, by means of a detailed examination of the course of the argument and a re-examination of Eutocius’ remarks. The paper reinterprets the role of the empirical in the early propositions and offers a reading of the contribution of Archimedes’ mechanics to the method of EP 1. [ABSTRACT FROM AUTHOR]

The dynamic performance of a high-speed train is heavily influenced by its centre of gravity and moment of inertia. Therefore, accurately measuring these parameters is crucial. This paper proposes an integrated test method for measuring the centre of gravity and moment of inertia based on the excitation method by analyzing the structural characteristics of the vibration test bench. The proposed method is efficient as it only requires installing the car body once, unlike the past method of combining excitation and suspension. This paper provides a comprehensive theoretical derivation of the method used to test the center of gravity and moment of inertia of a specific type of high-speed electrical motor units (EMU) car body. The results of the test were compared to the theoretical values, and the error was found to be minimal, meeting the necessary engineering application requirements. [ABSTRACT FROM AUTHOR]

According to accident case studies, one of the causes of accidents involving container ships was often the incorrectly declared weight of the container. For this reason, the International Maritime Organization introduced an amendment to the International Convention for the Safety of Life at Sea, requiring the verification of container weight declared in the transport document. It partially solved the problem of accurate determination of container ship stability, although an error of 5% by weight is accepted. In this study, using the Macs3 program, the weight of 100 containers was changed by 5% to assess how such a situation affects the ship's stability. It was found that even a slight change in the weight can affect stability. There are other problems that have to be addressed, e.g., loading of the containers as per positions in the loading plan or sharing information about mass distribution inside. In the last part, Ishikawa's diagram was used to determine the relationship between the causes and their effect on the accident of MSC Napoli in an attempt to determine other factors that may have contributed to the container ship's accident and highlight the need to systematize the rules and tools connected to container ship weighing. [ABSTRACT FROM AUTHOR]

Accurate accident reconstruction requires the knowledge of the mass properties of vehicles, namely the centre of gravity location, the mass and the inertia tensor. Such data are seldom available, especially in case of newly produced electric vehicles. In this paper, vehicle inertia measurements, performed at Politecnico di Milano, refer to a number of electric vehicles. In addition to the “simple” measurement of vehicle inertia, measured mass properties are analysed to derive the proper empirical formulae for the estimation of the centre of gravity height and the moments of inertia. Both internal combustion and electric vehicles are considered. Data show a significant difference in the mass properties of the two types of vehicles. The proposed formulae can be effectively employed to quickly obtain a reasonable estimation of the mass properties of any vehicle. The results show that electric vehicles are characterised by higher values of mass with respect to internal combustion vehicles, but they present a lower centre of gravity location and proportionally lower values of the moments of inertia.

Modern city buses are made of various construction materials and the share of material groups has changed over the decades. By replacing heavy materials for structural elements or bus components with their lighter counterparts, the kerb weight of the bus can be reduced by up to several hundred kilograms. This article presents the issues of the development of city bus design in terms of passenger space comfort and bus structure in the context of reducing the vehicle's own weight since the 1970s. The main changes in vehicle design allowing for reducing the weight of structural elements of bodies and chassis as well as the main assemblies in city buses are presented as well as research on body types in terms of aerodynamics, safety and travel comfort. It has been shown that reducing the weight of the bus does not negatively affect its load capacity and the new bus designs are equipped with safety and comfort systems, including ABS (Anti-lock Braking System), ASR (Automatic Stability Regulation), ESP (Electronic Stability Program) and air conditioning in the passenger space. Thanks to modern light construction materials, we gain the opportunity to improve safety and comfort without losing the transport capabilities developed as a result of the development of city buses over the years. [ABSTRACT FROM AUTHOR]

Welsh is a p-Celtic language spoken mostly in the British Isles. Its consonant inventory features six plosive phonemes, i.e. /p, t, k, b, d, g/. The Welsh plosives exhibit a contrast between the fortis and lenis series marked phonetically by a number of phonetic features, the most important of them being aspiration. A previous study on Welsh plosives conducted by the authors of this paper revealed that, unlike the other plosives, the Welsh /t/ has a strong tendency towards affrication in some contexts. Since affrication of plosives has received some attention in phonetic studies on other languages, it seemed striking that potential affrication of Welsh plosives has not yet been studied phonetically. The present study includes word-initial and word-final realisations of /t/ in Welsh monosyllabic lexemes. The analysis of four key spectral moments; namely, centre of gravity, dispersion, skewness and kurtosis, was conducted to confirm the assumptions regarding allophonic variation of the Welsh /t/ based on a visual inspection of spectrograms. The results suggest that the Welsh /t/ may actually have as many as four allophones, i.e. the aspirated allophone [th ], the affricated allophone [ts], which can also be aspirated in two different ways; namely, aspiration can occur simultaneously with affrication [tsh] or it can follow the affricated section [tsh]. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Forestry Society of Croatia / Sumarski List Hrvatskoga Sumarskoga Drustva is the property of Forestry Society of Croatia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article deals with the design of a concept for a mobile robotic platform for transporting equipment or people. For disabled people, this system can represent an alternative to a wheelchair with better mobility in an urbanized environment. The proposed solution is unique in that it maintains a stabilized vertical position of the base. [ABSTRACT FROM AUTHOR]

As an important spatial carrier of Hong Kong's economic development, construction land provides a critical site for Hong Kong's economic and social activities. The development of construction land directly affects the sustainable development of the city. Therefore, analysing the spatial and temporal evolution and driving mechanism of construction land in Hong Kong is of great significance in promoting sustainable urban development. This study aimed to evaluate the evolutionary characteristics and driving mechanism of construction land of Hong Kong in the period 1972–2020. Here, we extract construction land data from 1972 based on the historical map of Hong Kong. Then, we apply ArcGIS Pro and Fragstats software to calculate the rate of land expansion, land intensity, change in the centre of gravity, and landscape pattern index of construction land in Hong Kong from 1972–2020. Analysis shows the following: (1) The expansion of construction land in Hong Kong generally showed the characteristics of "rapid at first and then slowing down", with 2010 as the peak of the 1970–2020 timeframe. (2) The sources of construction land transfer mainly came from cultivated land, sea areas, and forest land, which were mainly distributed in the New Territories. (3) The centre of gravity of construction land in Hong Kong showed the spatial characteristics of "slowly shifting to the northwest" during the study period, indicating that Hong Kong's polycentric urban structure has been continuously strengthened. (4) The Spiltting index showed a tortuous upward trend, and the index of Mean Euclidean nearest neighbour distance showed a steady downward trend, which indicated that the landscape connectivity of city construction land steadily increased while the degree of fragmentation gradually increased. (5) The driving factors behind the expansion of Hong Kong construction land comes from population, economic, and traffic factors; the support factors come from location and policy factors; the elasticity factors mainly come from reclamation projects; the resistance factors mainly come from the restrictions of environmental protection departments, NGOs, and relevant laws on land reclamation. [ABSTRACT FROM AUTHOR]

According to accident case studies, one of the causes of accidents involving container ships was often the incorrectly declared weight of the container. For this reason, the International Maritime Organization introduced an amendment to the International Convention for the Safety of Life at Sea, requiring the verification of container weight declared in the transport document. It partially solved the problem of accurate determination of container ship stability, although an error of 5% by weight is accepted. In this study, using the Macs3 program, the weight of 100 containers was changed by 5% to assess how such a situation affects the ship’s stability. It was found that even a slight change in the weight can affect stability. There are other problems that have to be addressed, e.g., loading of the containers as per positions in the loading plan or sharing information about mass distribution inside. In the last part, Ishikawa’s diagram was used to determine the relationship between the causes and their effect on the accident of MSC Napoli in an attempt to determine other factors that may have contributed to the container ship’s accident and highlight the need to systematize the rules and tools connected to container ship weighing.

There are two techniques for a lateral sprint start: crossover (CS) and jab step (JS) starts. This study aimed to elucidate the difference in the CS and JS starts in terms of sprint performance and leg kinetics in athletes from ball-and-goal type sports (e.g. soccer and handball). Nineteen male athletes performed CS and JS starts, during which their motion and the force they applied to the ground were simultaneously recorded using a motion-capture system and two force platforms. The results showed that, although 5-m time via video analysis did not differ between CS and JS starts, forward velocity of centre of gravity (CG) and normalised average horizontal external power were greater for the JS start than the CS start. From waveform analysis, greater positive joint power in the sagittal plane leading to greater positive work in the JS start were found in the first three quarters of the push-off phase for rear hip extension and in the subsequent push-off phase for rear ankle plantar flexion. In conclusion, the results suggest that the JS start is superior to the CS start for start quickness, though the gains in the start did not appear to transfer to the 5-m performance. Moreover, greater positive joint power in the first three quarters of the push-off phase for the rear hip extension and in the subsequent push-off phase for the rear ankle plantar flexion were considered to be important contributing factors to the better performance of the JS start. [ABSTRACT FROM AUTHOR]

This article applies grounded theory and epistemological, teleological, ontological, and methodological (ETOM) lenses to describe the prevalent contemporary theories of the centre of gravity concept, originated by Carl von Clausewitz. These include the theories of John Warden, Joe Strange & Richard Iron, Antulio Echevarria II, Milan Vego, Dale Eikmeier, and Jacob Barfoed. The article then compares the theories across 14 deduced theoretical aspects and produces a comparison matrix, that can be used as an analytical tool, and discusses implications as guidance for further research and doctrine development. The article argues that the term "centre of gravity" is polluted, and that the application of the term in military planning and doctrines requires careful attention to the specific theory being applied, so that logical consistency and clear, accurate communication is achieved. Alternatively, the concept may be removed from doctrine altogether, renovated with inclusion of a new unpolluted term, or reconstructed with removal of the centre of gravity, leaving a "critical factor analysis" concept behind. This article also provides a level of granularity to the debate about the concept, that renders critics like Paparone & Davis Jr and Zweibelson partly irrelevant and can provide a more nuanced and qualitative basis for future discussion. [ABSTRACT FROM AUTHOR]

The spatial variability of soil nutrients can improve the yield per unit area of food crops and protect the agricultural ecological environment. Geostatistics and geographic information system (GIS) technology were applied to analyse the spatiotemporal variability and main influencing factors in soil organic matter (SOM) and soil total nitrogen (STN) in ecologically fragile regions of the Loess Plateau, China. The results showed that the mean SOM and STN contents significantly increased in the past 40 years. Compared to the 1980 data, both SOM and STN global Moran's I indices are lower, with less spatial structure and an increased role for stochastic factors. The centre of gravity of soil nutrients in the study area mainly to the south-east, a reduction in the area of the ellipse and a tendency to concentrate the spatial distribution of nutrients. And it was concluded that the variation in nutrients was mainly influenced by fertiliser management practices. Therefore, a long time series of soil nutrient study is of great research value to clarify the soil nutrient status of the study area and to improve the efficiency of arable land use, as well as providing a theoretical basis for precision agriculture. [ABSTRACT FROM AUTHOR]

Copyright of Contemporary Military Challenges / Sodobni Vojaški Izzivi is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of geostatistical indices to examine fishery-dependent data over time is novel. We assess the value of a range of these indices for describing trends in boat-based recreational fishing in Western Australia and areas of high effort and catches for two demersal species with varying biological characteristics, life histories and distributions. The number of blocks (10-× 10-nautical mile (~19-× 19-km) area) visited decreased by 40%, while the number of fishing trips with demersal species catch increased by 15%. Spatial indices showed a south-easterly shift in demersal catch per unit effort (CPUE) across survey years. The southerly shift of West Australian dhufish (Glaucosoma herbraicum) CPUE and subsequent return to the north likely to reflect the response of this temperate species to a marine heatwave. In comparison, CPUE of retained Baldchin groper (Choerodon rubescens) shifted north, whereas released catches shifted south with high probabilities of hotspots present associated with habitat structure. We identified hotspots of retained and released CPUE, highlighting potential areas where species experience high post-release mortality through barotrauma, and targeted spatial management strategies. Spatial indices allow quantitative definition of the structure of the fishery, identify high catch areas, and assess changes over time at a broader scale to sustainably manage multispecies fisheries. [ABSTRACT FROM AUTHOR]

The problem of increasing the accuracy of determining the mass and centre of gravity of vehicles in order to reduce accidents and improve transportation safety is considered. A comparative analysis of various systems and methods for determining the mass and centre of gravity of vehicles has been carried out. The advantages of non-contact methods and mass measuring instruments have been shown. The technique of non-contact determination of the vehicle mass by the vertical movement of its body has been proposed. An analytical and simulation model of a system for non-contact determination and remote control of the mass and centre of gravity of vehicles has been developed. On the example of aircrafts, the possibilities of simulating this system using various interpolation methods have been considered. For Airbus aircrafts, experiments have been carried out in the MathCad software using linear interpolation, fitting methods, least squares method, and Lagrange polynomials. The principles of constructing a system for non-contact determination of the mass and centre of gravity of aircrafts have been proposed. The choice of methods and instruments for measuring the aircraft fuselage vertical displacement for the implementation of such a system has been substantiated. The research results provide the possibility and prospect of creating a system for non-contact remote control of the mass and centre of gravity of aircrafts, as well as other types of aerial vehicles. [ABSTRACT FROM AUTHOR]

This paper deals with the measurement of spectral moments of Serbian fricatives. The four spectral moments: centre of gravity, spectral variance, skewness, and kurtosis were measured at the onset of the fricative, on the stable-state part and at the fricative offset. The results show that the highest values for the centre of gravity can be found in non-sibilants, except for the sound [v]. The measurements were taken in both Hertz and Bark scales, and the results show that the Bark scale serves better in distinguishing fricative types. The energy which is generated during the fricatives' production is not evenly allocated in the time-course of the fricative length. Voiced and voiceless fricatives differ in force of articulation within the fricative duration. The greatest factor effects were found to be the place of articulation and phonological voicing. The vowel that follows does not statistically influence the spectral moments’ values, except for the difference in fricative [x] which surfaces as an acoustically different segment before the vowels [i] and [u].

Retraction of /s/ to a more [ʃ]-like sound is a well-known sound change attested across many varieties of English for /stɹ/ words, e.g. street and strong. Despite recent sociophonetic interest in the variable, there remains disagreement over whether it represents a case of long-distance assimilation to /ɹ/ in these clusters or a two-step process involving local assimilation to an affricate derived from the sequence /tɹ/. In this paper, we investigate Manchester English and apply similar quantitative analysis to two contexts that are comparatively under-researched, but which allow us to tease apart the presence of an affricate and a rhotic: /stj/ as in student, which exhibits similar affrication of the /tj/ cluster in many varieties of British English, and /stʃ/ as in mischief. In an acoustic analysis conducted on a demographically-stratified corpus of over 115 sociolinguistic interviews, we track these three environments of /s/-retraction in apparent time and find that they change in parallel and behave in tandem with respect to the other factors conditioning variation in /s/-retraction. Based on these results, we argue that the triggering mechanisms of retraction are best modelled with direct reference to /t/-affrication and with /ɹ/ playing only an indirect, and not unique, role. Analysis of the whole sibilant space also reveals apparent-time change in the magnitude of the /s/–/ʃ/ contrast itself, highlighting the importance of contextualising this change with respect to the realisation of English sibilants more generally as these may be undergoing independent change.

As an important spatial carrier of Hong Kong’s economic development, construction land provides a critical site for Hong Kong’s economic and social activities. The development of construction land directly affects the sustainable development of the city. Therefore, analysing the spatial and temporal evolution and driving mechanism of construction land in Hong Kong is of great significance in promoting sustainable urban development. This study aimed to evaluate the evolutionary characteristics and driving mechanism of construction land of Hong Kong in the period 1972–2020. Here, we extract construction land data from 1972 based on the historical map of Hong Kong. Then, we apply ArcGIS Pro and Fragstats software to calculate the rate of land expansion, land intensity, change in the centre of gravity, and landscape pattern index of construction land in Hong Kong from 1972–2020. Analysis shows the following: (1) The expansion of construction land in Hong Kong generally showed the characteristics of “rapid at first and then slowing down”, with 2010 as the peak of the 1970–2020 timeframe. (2) The sources of construction land transfer mainly came from cultivated land, sea areas, and forest land, which were mainly distributed in the New Territories. (3) The centre of gravity of construction land in Hong Kong showed the spatial characteristics of “slowly shifting to the northwest” during the study period, indicating that Hong Kong’s polycentric urban structure has been continuously strengthened. (4) The Spiltting index showed a tortuous upward trend, and the index of Mean Euclidean nearest neighbour distance showed a steady downward trend, which indicated that the landscape connectivity of city construction land steadily increased while the degree of fragmentation gradually increased. (5) The driving factors behind the expansion of Hong Kong construction land comes from population, economic, and traffic factors; the support factors come from location and policy factors; the elasticity factors mainly come from reclamation projects; the resistance factors mainly come from the restrictions of environmental protection departments, NGOs, and relevant laws on land reclamation.

Oculomotor research shows that eye movements are primed toward the midpoint of an array of visual stimuli, such that an eye movement to a visual target is executed most rapidly when it appears near the midpoint of an earlier array. At longer intervals between the prime and target, this facilitatory effect can reverse to become inhibitory - such that eye movements are slower when made toward the midpoint - but the source of this inhibition is unclear. One of our prior studies suggests a global source: target proximity to the midpoint determines inhibition, consistent with the notion that oculomotor activation is responsible for the effect and the original definition of inhibition of return. A later study suggests a local source: target proximity to the nearest array element determines inhibition, consistent with the notion that repeat stimulation of an input pathway is responsible. To resolve the ambiguity we systematically test whether timing differences between studies altered the source of the inhibition. We find that both previously observed patterns are reproducible depending on the prime offset - target onset asynchrony. We also resolve the discrepancy by showing that when this asynchrony is less than 200 ms, target proximity to the array's midpoint and its proximity to any given array element can jointly determine inhibition, whereas when the asynchrony is approximately 200 ms, inhibition is robust at the midpoint of the array. At longer asynchronies, all inhibitory effects rapidly dissipate. [ABSTRACT FROM AUTHOR]

Motor cortical representation can be probed non-invasively using a transcranial magnetic stimulation (TMS) technique known as motor mapping. The mapping technique can influence features of the maps because of several controllable elements. Here we review the literature on six key motor mapping parameters, as well as their influence on outcome measures and discuss factors impacting their selection. 132 of 1,587 distinct records were examined in detail and synthesized to form the basis of our review. A summary of mapping parameters, their impact on outcome measures and feasibility considerations are reported to support the design and interpretation of TMS mapping studies. [ABSTRACT FROM AUTHOR]

Floating devices under wave and current loads are typically designed based on numerical methods followed by a validation with experimental investigations. This allows an independent check due to the comparison of two different modelling approaches based on different assumptions. At an early stage of the project, numerical simulations are based on theoretical (ideal) values of the centre of gravity (CG) and moment of inertia (MI). The building process of a scaled model results very often in a requested simplification of certain parts, which can influence the CG and also the MI of the scaled model. Knowing those discrepancies allows us to improve the comparability of both approaches but the measurement of those values is connected with either a higher uncertainty or a high level of effort. A significant improvement of such measurements can be reached by the deployment of a specific experimental set-up. This paper presents the classification of the newly designed swing with a high accuracy inertial inclinometer, which was verified by the marker-based motion capturing system. The achieved experiences are useful for the future use of the set-up as well as similar investigations. The comparison with the theoretical values for the swing as well as an example model showed very good agreements and a high accuracy of few millimetres for the CG and an error smaller 1% for MI. [ABSTRACT FROM AUTHOR]

Fuzzy entropy (FuzEn) was introduced to alleviate limitations associated with sample entropy (SampEn) in the analysis of physiological signals. Over the past decade, FuzEn-based methods have been widely used in various real-world biomedical applications. Several fuzzy membership functions (MFs), including triangular, trapezoidal, Z-shaped, bell-shaped, Gaussian, constant-Gaussian, and exponential functions have been employed in FuzEn. However, these FuzEn-based metrics have not been systematically compared yet. Since the threshold value r used in FuzEn is not directly comparable across different MFs, we here propose to apply a defuzzification approach using a surrogate parameter called 'center of gravity' to re-enable a fair and direct comparison. To evaluate these MFs, we analyze several synthetic and three clinical datasets. FuzEn using the triangular, trapezoidal, and Z-shaped MFs may lead to undefined entropy values for short signals, thus providing a very limited advantage over SampEn. When dealing with an equal value of the center of gravity, the Gaussian MF, as the fastest algorithm, results in the highest Hedges' g effect size for long signals. Our results also indicate that the FuzEn based on exponential MF of order four better distinguishes short white, pink, and brown noises, and yields more significant differences for the short real signals based on Hedges' g effect size. The triangular, trapezoidal, and Z-shaped MFs are not recommended for short signals. We propose to use FuzEn with Gaussian and exponential MF of order four for characterization of short (around 50-400 sample points) and long data (longer than 500 sample points), respectively. We expect FuzEn with Gaussian and exponential MF as well as the concept of defuzzification to play prominent roles in the irregularity analysis of biomedical signals. The MATLAB codes for the FuzEn with different MFs are available at https://github.com/HamedAzami/FuzzyEntropy_Matlab.

Abstract Background Various musculoskeletal changes occurring during pregnancy may lead to the change in gait and contribute to the increase in walking energy expenditure. Previous research indicates that changes in gait mechanics may lead to the increase in mechanical work required during walking. However, there is little information to indicate if changes in gait mechanics during pregnancy have impact on active or total energy expenditure. Therefore, the primary aim of this study was to investigate the relationship between changes in gait kinematics and walking energy expenditure in pregnant women. Methods Thirty-five women (mean age = 27.5 ± 6.1 years) volunteered for the study during various stages of pregnancy (1st trimester average = 12.1 ± 2.2 weeks; 2nd trimester = 22.3 ± 2.6 weeks; 3rd trimester = 31.4 ± 2.6 weeks). 3D motion analysis was used to assess changes in kinematic parameters during walking at self-selected pace. Resting metabolic rate, and walking energy expenditure expressed in terms of rate and cost of O2 were analysed with portable metabolic analyser. Results Only medio-lateral deviation of centre of gravity (COGML) increased 13.6% between the 1st and 2nd, and 39.3% between 2nd and 3rd trimester (p ≤ 0.001). However, self-selected walking speed depicted strong significant positive linear relationship with net O2 rate (r = 0.70; p ≤ 0.001), and was strongly associated with the vertical excursion of the COG (r = 0.75, p ≤ 0.001). Conclusions Changes in gait mechanics during pregnancy may lead to an increase in walking energy expenditure. However, the consequent increase in walking energy cost may not be sufficient to offset the natural energy sparing mechanism.

Accuracy in determination of coordinates for image having simple shapes is considered as one of important and significant parameters in metrological optoelectronic systems such as autocollimators, stellar sensors, Shack-Hartmann sensors, schemes for geometric calibration of digital cameras for aerial and space imagery, various tracking systems. The paper describes a mathematical model for a measuring stand based on a collimator which projects a test-object onto a photodetector of an optoelectronic device. The mathematical model takes into account characteristic noises for photodetectors: a shot noise of the desired signal (photon) and a shot noise of a dark signal, readout and spatial heterogeneity of CCD (charge-coupled device) matrix elements. In order to reduce noise effect it is proposed to apply the Wiener filter for smoothing an image and its unambiguous identification and also enter a threshold according to brightness level. The paper contains a comparison of two algorithms for determination of coordinates in accordance with energy gravity center and contour. Sobel, Pruitt, Roberts, Laplacian Gaussian, Canni detectors have been used for determination of the test-object contour. The essence of the algorithm for determination of coordinates lies in search for an image contour in the form of a circle with its subsequent approximation and determination of the image center. An error calculation has been made while determining coordinates of a gravity center for test-objects of various diameters: 5, 10, 20, 30, 40, 50 pixels of a photodetector and also signalto-noise ratio values: 200, 100, 70, 20, 10. Signal-to-noise ratio has been calculated as a difference between maximum image intensity of the test-object and the background which is divided by mean-square deviation of the background. The accuracy for determination of coordinates has been improved by 0.5-1 order in case when there was an increase in a signal-to-noise ratio. Accuracy improvement due to increase of a diameter in a test-object is typical for large signal-to-noise ratios: 70 or more. The conducted investigations have made it possible to establish that the algorithm for determination of coordinates of the energy gravity center is more accurate in comparison with contour methods and requires less computing power (for the MatLab software package), which is related to discreteness while determining a contour.

The paper presents a static lateral stability of a sub-compact tractor MT8-070 Mini in relation to a safe tractor operation. Axle weight distribution of the tractor was measured to calculate the vertical and longitudinal coordinates of a centre of gravity (COG). Experiments were aimed at the tractor equipped with no and four levels of rear wheel ballast weights (30.5, 61, 91.5 and 122 kg) at standard and extended overall width on tyres. A static overturning angle was calculated and experimentally measured when the tractor with right wheels touching the ground was in a state of unstable equilibrium. Comparing the experimental data with ISO 16231-2 (2015), the differences were 2.57%, 2.80%, 3.04%, 3.42% and 3.88% in the case of the standard overall width on tyres and 2.40%, 2.61%, 3.11%, 3.67% and 3.99% in the case of the extended overall width on tyres at 0, 30.5, 91.5 and 122 kg of the rear wheel ballast weight. Considering the vertical tyre deformation and the lateral shift of the tyre, the differences decreased to 0.95%, 1.11%, 1.29%, 1.85% and 1.42% (standard overall width on tyres) and 0.91%, 1.18%, 1.69%, 2.27% and 2.57% (extended overall width on tyres). The length of a rubber lug of a tyre contact patch did not change when the tractor was inclined at various ballast weights and did not affect the static overturning angle calculation according to ISO 16231-2 (2015). Results showed higher static overturning angle experimentally measured in comparison with calculated according to ISO 16231-2 (2015) due to the tyre deformation. Limiting the tractor operation on the basis of the static overturning angle calculated according to ISO 16231-2 (2015) avoids the tractor usage under dangerous operation conditions. [ABSTRACT FROM AUTHOR]

This study aimed at analysing the influence of the position of the centre of gravity variability and the movement velocity on the demand for a torque and work time coverage of a wheelchair with an electromechanical drive. The variable parameter in the study was the configuration of the wheelchair, namely changes in the position of the batteries which changed the weight distribution. An analytical model describing the demand for torque was used in the analysis. The set of equations was introduced into the numerical calculation software. Simulations were carried out which allowed it to analyse selected parameters of the wheelchair dynamics. An increase in the torque demand was observed due to the increase in the mass of the system from 427.7 N to 533.1 N, ranging from 6.1% to 31.6% at the simulated velocity v7 = 4.2 m/s. The increase in the demand for torque due to the increase in velocity of the wheelchair from v2 = 1.05 m/s to v7 = 4.2 m/s ranged from 25.9% to 31.6% compared to the reference velocity v1 = 0.525 m/s. The centre of gravity of the wheelchair structure localization has a non-linear impact on the analysed values. At the same time, it was not possible to define its nature—this issue remains open and requires further research.

Floating devices under wave and current loads are typically designed based on numerical methods followed by a validation with experimental investigations. This allows an independent check due to the comparison of two different modelling approaches based on different assumptions. At an early stage of the project, numerical simulations are based on theoretical (ideal) values of the centre of gravity (CG) and moment of inertia (MI). The building process of a scaled model results very often in a requested simplification of certain parts, which can influence the CG and also the MI of the scaled model. Knowing those discrepancies allows us to improve the comparability of both approaches but the measurement of those values is connected with either a higher uncertainty or a high level of effort. A significant improvement of such measurements can be reached by the deployment of a specific experimental set-up. This paper presents the classification of the newly designed swing with a high accuracy inertial inclinometer, which was verified by the marker-based motion capturing system. The achieved experiences are useful for the future use of the set-up as well as similar investigations. The comparison with the theoretical values for the swing as well as an example model showed very good agreements and a high accuracy of few millimetres for the CG and an error smaller 1% for MI.

How special is Centros? This contribution places Centros in internal market law. It starts by turning the judgment on its head and imagines an alternative Centros: the judgment that the Danish authorities had wished for and which the Court declined to hand down. The aim of this exercise in legal fiction is to show that the Court could have decided Centros in another way. The choices underpinning Centros are then contrasted with other internal market cases to conclude that both the real Centros and the alternative Centros are in some ways aligned with the free movement case law. It is argued that Saydé's analysis of abuse best helps to make sense of this confusing state of play. The article ends with suggestions for further research: taking the cost dimension into account in a behavioural perspective could shed light on the allocation of regulatory powers between home state and host state. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Public Law / Zeitschrift für Öffentliches Recht is the property of Verlag Oesterreich GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Analytical optical field of a cosh-Airy beam in uniaxial crystals is derived. • The centre of gravity, the beam spot size, and the linear momentum are derived. • The influence of the uniaxial crystal on the cosh-Airy beam is investigated. • The effect of the cosh part on the cosh-Airy beam is also investigated. • The propagation properties of the cosh-Airy beam are shown to be abundant. Analytical optical field of a cosh-Airy beam propagating in uniaxial crystals orthogonal to the optical axis is presented. Analytical expressions of the centre of gravity, the beam spot size, and the linear momentum for the cosh-Airy beam in uniaxial crystals are also derived, respectively. The propagation properties of a cosh-Airy beam are numerically demonstrated in the uniaxial crystal. The cosh-Airy beam still has the feature of self-acceleration in the two transverse directions. However, the cosh-Airy beam in the y -direction accelerates more slowly than that in the x -direction. The centre of gravity and the beam spot size in the y -direction are always less than those in the x -direction. The influence of the uniaxial crystal on the intensity distribution, the phase distribution, the centre of gravity, the beam spot size, and the linear momentum of a cosh-Airy beam is investigated. The effect of the cosh part on the centre of gravity, the beam spot size, and the linear momentum is also studied in detail. The centre of gravity of the cosh-Airy beam is less than that of the corresponding Airy beam. However, the beam spot size and the linear momentum of the cosh-Airy beam are larger than those of the corresponding Airy beam. [ABSTRACT FROM AUTHOR]

Restoring the ability to walk with a prosthesis is considered a fundamental rehabilitation goal after transfemoral amputation. An essential prerequisite for achieving this goal is adequate force transmission between the prosthesis and the body. Does bone anchorage of an artificial limb permit a more normal force transmission? Data of 15 healthy subjects, nine amputees fitted with bone-anchored prostheses, nine amputees using socket prostheses, and 18 patients with a total hip replacement were included in this multicenter, observational study. Ground reaction force was measured using Kistler force plates. Kinematics was recorded with 12 Vicon Bonita cameras. Subjects were instructed to walk at three different speeds: first at their self-selected, then at slow, and finally at fast speed. Self-selected walking speeds of subject groups were significantly different, osseointegrated amputees walked the slowest. The lowest ground reaction force was measured for osseointegrated amputees on the prosthetic side, who also showed the highest force on their contralateral side. Patients with hip replacements showed values similar as healthy subjects. The vertical center of gravity movement was specific for each subject group. The force transmission capacity of the bone-anchored prosthetic leg is limited during walking and is lower than both in socket prostheses users without symptoms and patients with total hip replacement. Therefore, active amputees well fitted with a socket prosthesis who consider a transition to bone-anchorage should be advised that their walking speed may decrease with high probability, and that their self-selected walking speed may even be slower than 3 km/h. • Restoring gait with bone-anchored versus socket prostheses and hip replacements • Osseointegrated amputees have a special gait adaptation to unload the prosthetic leg • Physiological gait is impossible • Reduced force transmission in the implant-bone interface can be ruled out as a cause • Bone-anchored prostheses can be recommended at walking speeds of slower than 3 km/h [ABSTRACT FROM AUTHOR]

Knowledge of Mass Moment of Inertia of human body and its segments are necessary for various problems in biomechanics and its applications. This paper focusses on the estimation of Moment of Inertia of a human body when bending forward, which is needed for designing a robotic self-transfer facility for elderly and disabled. This paper also covers a brief review on studies of different anthropometric data like mass of the body segments, Centre of Mass, radius of gyration, etc. Using these data and certain assumptions, Mass Moment of Inertia of human body bending forward is estimated by applying laws of basic mechanics. This estimated value is then validated using a solid modelling CAD software.

The paper presents a static lateral stability of a sub-compact tractor MT8-070 Mini in relation to a safe tractor operation. Axle weight distribution of the tractor was measured to calculate the vertical and longitudinal coordinates of a centre of gravity (COG). Experiments were aimed at the tractor equipped with no and four levels of rear wheel ballast weights (30.5, 61, 91.5 and 122 kg) at standard and extended overall width on tyres. A static overturning angle was calculated and experimentally measured when the tractor with right wheels touching the ground was in a state of unstable equilibrium. Comparing the experimental data with ISO 16231-2 (2015), the differences were 2.57%, 2.80%, 3.04%, 3.42% and 3.88% in the case of the standard overall width on tyres and 2.40%, 2.61%, 3.11%, 3.67% and 3.99% in the case of the extended overall width on tyres at 0, 30.5, 91.5 and 122 kg of the rear wheel ballast weight. Considering the vertical tyre deformation and the lateral shift of the tyre, the differences decreased to 0.95%, 1.11%, 1.29%, 1.85% and 1.42% (standard overall width on tyres) and 0.91%, 1.18%, 1.69%, 2.27% and 2.57% (extended overall width on tyres). The length of a rubber lug of a tyre contact patch did not change when the tractor was inclined at various ballast weights and did not affect the static overturning angle calculation according to ISO 16231-2 (2015). Results showed higher static overturning angle experimentally measured in comparison with calculated according to ISO 16231-2 (2015) due to the tyre deformation. Limiting the tractor operation on the basis of the static overturning angle calculated according to ISO 16231-2 (2015) avoids the tractor usage under dangerous operation conditions.

The article deals with correlation of strategy and operational art. The aim of the article is to point on deficit of relationship between political decision-making and military planning. The first part of the article simply introduces doctrinal tools of operational art, applicable at both the operational and strategic level. The second part refers to the fact that application of some standard elements of operational art in terms of overall strategic framework loses partly importance because of their use in the context of unconventional conflict has been less appropriate. The third part deals with criticism of the mutual undesirable separation of politicians and military professionals involved in operations planning. Conclusion of the article offers possible solutions of this deficit.

This study examined if the centre of mass (CM) position of static balances in gymnastics textbooks were correctly illustrated. Out of 108 gymnastics textbooks screened for figures that illustrated CM positions in static balance postures, 33 images from four textbooks were retrieved for analysis. In each image, the actual CM was calculated using the segmentation method based on measured segmental lengths and body segmental inertial parameters. The offset distance between the illustrated and calculated CM was quantified to indicate the accuracy of the book illustration. To facilitate comparisons among images of different sizes, the offset distance was normalised to the leg length of the body as a percentage error. An error of less than 10% was considered small, 10 to 20% moderate, and greater than 20% large. Results showed that the average error was 12.8% (ranging from 0% to 39.0%). The error was small in 17 (52%) images, moderate in 11 (33%) images, and large in 5 (15%) images. Calculated CM were often (26 out of 33, or 78.8%) superior to the illustrated positions. One common misconception was that the illustrated CM tended to lie within the body in postures where the calculated CM was outside the body (e.g. half headstand, seated pike stretch). These incorrect CM illustrations and concepts in gymnastics textbooks may misguide the pedagogical practices for physical education teachers and coaches. To better reflect the true CM of gymnastics postures, future reference materials should incorporate anatomical and biomechanical expertise in the preparation of figures. [ABSTRACT FROM AUTHOR]

This paper proposes a procedure to mathematically model the counterweight of rotating links based on calculations according to design requirements. The main objective of the research is to introduce an effective method to design the counterweight using CAD drawing. A parameterized equation is formulated with the help of counterweight geometry derived from a typical crankshaft counterweight design. Using the law of moments and Center of gravity of links, the geometry of counterweight can be found using the formula that is parameterized with a single variable. The results were obtained by finding the roots of the final equation. The method was found to be effective in term of time consumption rather than implementing the iterative method. [ABSTRACT FROM AUTHOR]

Assembly Sequence Planning (ASP) is one of the well-known optimization problems in the manufacturing industry. It represents a great deal of interest over the past three decades. This paper aims to present a method for generating ASP, taking into account the stability assignment during assembly’s operations. The developed method uses the topological and geometrical assembly constraints extracted and generated from CAD system (assembly constraints, mass and center of gravity of components, interference and contact matrices), to guarantee the generation of a feasible ASP. The main contribution of this research is the development of a method which respects the stability assignment of heavy machines during the assembly’s operations. Also, it reduces the design costs and minimizes the time of replacement or repair of failing components of industrial equipments, which has become complicated task given the complexity of today’s mechanisms. A validation example is used to highlight the advantages of the proposed approach. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to examine the validity of total body centre of gravity (COG) measurement during gait with markerless motion capture system (MLS) on the basis of values acquired with a marker-based motion capture system (MBS).Materials and Methods: Thirty young healthy subjects walked on a flat surface as coordinate data from their bodies were acquired using the Kinect v2 (as a MLS) and Vicon systems (as a MBS). COG was calculated using coordinate data of the total body. Comparisons of COG ensemble curves in the mediolateral and vertical directions were performed between MLS and MBS throughout the gait cycle. The relative consistency between these systems was assessed using Pearson correlation coefficients.Results: The COG trajectory made by using MLS data followed the trend of the COG trajectory with MBS in the mediolateral direction. In the vertical direction, however, the COG trajectories did not match between two systems. High correlation coefficients (r  > 0.79) were observed from 30% to 80% of the gait cycle. The greatest difference of COG between MLS and MBS in the mediolateral direction was 1.1 mm. Differences in the vertical direction appeared to be proportional to the distance between the participant and the Kinect v2 sensor.Conclusion: In the mediolateral direction, COG calculated with MLS data during gait was validated with COG calculated on the basis of a MBS. Further correction of systematic error is necessary to improve the validity of COG calculations in the vertical direction. [ABSTRACT FROM AUTHOR]

• A method to identify the 3D position of the CoG in a tiltrotor aircraft using photogrammetry and scales without previous levelling the aircraft. • Fast and automated method for the CoG measurement. • Multibody simulation of the system to obtain validation data for the proposed method. • Evaluation of the uncertainty of the measurement considering the uncertainty of the sensors used. • Suitable results of the proposed method and identification of the most relevant factor influencing the results. The aircraft weight and balance are a consequence of the own mass and the payload distribution, resulting in a position of the Centre of Gravity (CoG) that affect the behavior of the aircraft, its stability and the control effectiveness. The aircraft weight is normally measured statically using ground scales or sensors in the landing gear axles or struts, driving to 2D measurements of the CoG in longitudinal and lateral directions. Sometimes the 3D measurement is relevant because the aircraft architecture can involve weight shifts, i.e., the tiltrotor case. This paper studies the fast 3D measurement of the CoG in a tiltrotor type aircraft using photogrammetry and scales without previous levelling the aircraft. The system is modelled using multibody simulations to obtain data for the validation of the proposed methods. Finally, the expected uncertainty of the measurement is evaluated using Montecarlo method, analyzing the results statistically. [ABSTRACT FROM AUTHOR]

Centre of mass is a fundamental anatomical and biomechanical parameter. Knowledge of centre of mass is essential to inform studies investigating locomotion and other behaviours, through its implications for segment movements, and on whole body factors such as posture. Previous studies have estimated centre of mass position for a range of organisms, using various methodologies. However, few studies assess the accuracy of the methods that they employ, and often provide only brief details on their methodologies. As such, no rigorous, detailed comparisons of accuracy and repeatability within and between methods currently exist. This paper therefore seeks to apply three methods common in the literature (suspension, scales and digital modelling) to three 'calibration objects' in the form of bricks, as well as three birds to determine centre of mass position. Application to bricks enables conclusions to be drawn on the absolute accuracy of each method, in addition to comparing these results to assess the relative value of these methodologies. Application to birds provided insights into the logistical challenges of applying these methods to biological specimens. For bricks, we found that, provided appropriate repeats were conducted, the scales method yielded the most accurate predictions of centre of mass (within 1.49 mm), closely followed by digital modelling (within 2.39 mm), with results from suspension being the most distant (within 38.5 mm). Scales and digital methods both also displayed low variability between centre of mass estimates, suggesting they can accurately and consistently predict centre of mass position. Our suspension method resulted not only in high margins of error, but also substantial variability, highlighting problems with this method. [ABSTRACT FROM AUTHOR]

This article presents a structural analysis of the Unmanned Aerial System UAS-S4 ETHECATL. Mass, centre of gravity position and principal mass moment of inertia are numerically determined and further experimentally verified using the ‘pendulum method’. The numerical estimations are computed through Raymer and DATCOM statistical-empirical methods coupled with mechanical calculations. The mass of the UAS-S4 parts are estimated according to their sizes and the UAS-S4 class, by the means of Raymer statistical equations. The UAS-S4 is also decomposed in several simple geometrical figures which centres of gravity are individually computed, weighted and then arithmetically averaged to find the whole UAS-S4 centre of gravity. In the same way, DATCOM equations allows us to estimate the mass moments of inertia of each UAS-S4 parts that are finally sum up according to the Huygens-Steiner theorem for computing the principal moment of inertia of the whole UAS-S4. The mass of de UAS-S4 is experimentally determined with two scales. Its centre of gravity coordinates and its mass moment of inertia are found using the pendulum method. A bifilar torsion-type pendulum methodology is used for the vertical axis(14) and a simple pendulum methodology is used for the longitudinal and transversal axes(12). The test object is installed on a pendulum (simple or bifilar torsion pendulum) which is led to oscillate freely while recording the oscillation's angles and speed, by the means of three sensors (an accelerometer, a gyroscope and a magnetometer) that the calibration is also discussed. Simultaneously, nonlinear dynamic models are developed for the rotational motion of pendulums, including the effects of large-angle oscillations, aerodynamic drag, viscous damping and additional momentum of air. ‘Algorithms of minimization’ are then used to simulate and actualise the dynamic models and finally chose the model that simulated data best fit the experimentally recorded one. Pendulum parameters, such as mass moment of inertia, are lastly extracted from the chosen model. To determine the accuracy of the nonlinear dynamics approach of the pendulum method, the experimental results for an object of uniform density for which the mass moments of inertia are computed numerically from geometrical data are presented along with the experimental results obtained for the UAS-S4 ETHECATL. For the uniform density object, the experimental method gives, with respect to the numerical results, an error of 4.4% for the mass moment of inertia around the Z axis and 9.5% for the moment of inertia around the X and Y axes. In addition, the experimental results for the UAS-S4 inertial values validate the numerical calculation through DATCOM method with a relative error of 6.52% on average. [ABSTRACT FROM PUBLISHER]

Copyright of Archives of Mining Sciences is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An 8-month greenhouse experiment with ryegrass ( Lolium perenne L.) examined the relationship between the dynamics of potassium (K) reserves in soil and changes in clay minerals, using X-ray diffraction. The capacity of soil to release K was consistent with its ability to supply it and was the highest in the soil samples collected from Laiyang (H1T2a), Harbin (H1T1) and Beibei (H2T4), followed by the sample from Jiangyan (H1T2b), and the lowest in the samples from Gao'an (H2T3a) and Wangcheng (H2T3b). Removal of soil K decreases the intensity of reflections for illite and increases that for interstratified clay minerals. The centre of gravity values of the clay fractions was significantly negatively correlated to the depletion of soil K reserves, as ascertained through chemical extraction or through plant action. The quantitative regression equations between the centre of gravity values and the dynamics of soil reserves of K can be used for predicting the release and plant availability of K even without growing a crop. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]