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Background Despite its utility, uncertainty exists on the feasibility of acute peritoneal dialysis (PD) and optimal PD catheter type for very low birth weight (VLBW < 1500 g) and extremely low birth weight (ELBW < 1000 g) infants. We hereby report our experience of acute PD among these high-risk infants and compare the outcome between stylet-based rigid catheter (SRC) and Cook Mac-Loc Multipurpose Drainage catheters® (CMMDC). Methods Case notes of infants < 1500 g undergoing PD between 2012 and 2021 in a network of five participating neonatal units supported by a tertiary paediatric nephrology centre in Kolkata, India, were retrospectively reviewed. PD was conducted either with SRC or after 2018 with CMMDC. Outcome parameters included complications, survival during PD, and survival to discharge. Results 24 infants (VLBW: n = 13 and ELBW: n = 11) underwent PD at median age 4.5 days (IQR 3-6) with either CMMDC (n = 14) or SRC (n = 10). Significant improvement in biochemical parameters and fluid removal was seen in both ELBW and VLBW infants. CMMDC was associated with significantly fewer PD-related complications 7/14 (50%) vs. 9/10 (90%) (p = 0.04) and higher survival during PD 13/14 (93%) vs. 5/10 (50%) (p = 0.02), without significant difference in survival to hospital discharge 8/14 (57%) vs. 3/10 (30%) (p = 0.25). CMMDC also enabled longer duration of PD, higher ultrafiltration, and better control of acidosis. Consumable cost was higher for CMMDC (USD$60) than SRC (USD$14). Conclusions In a low resource setting, CMMDC had lower PD complications and superior short-term survival among ELBW/VLBW infants. Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information, Author(s): Rajiv Sinha [sup.1] [sup.2] , Rana Saha [sup.1] [sup.3] [sup.4] , Deblina Dasgupta [sup.1] , Niladri Bose [sup.1] , Shamik Ghosh [sup.5] , Ashok Modi [sup.4] , Bikramjit Das [...]

Childhood and adolescent obesity is a public health concern worldwide. However, little attention has been paid on status of overweight and body composition of Indian Bengali urban middle and high SES population. The objective was to determine the prevalence of overweight and body composition status by age and sex in children, adolescents and young adults. This cross-sectional study was carried out among 4194 unmarried school and college students (1999 males and 2195 females) aged 7–21 years belonging to the Bengali Hindu Population in Kolkata, India. The survey period was from 1999 to 2011. Anthropometry of participants were measured. Age and sex specific ≥85 percentile of body mass index (BMI) for children (

With increasing interest and investment, the shipping industry is witnessing solid development in autonomous operations of vessels and transport networks in various configurations including the Shore Control Center (SCC) concept where command, control, and/or monitoring of ships will take place from the shore. However, detailed competence requirements for the SCC Operator (SCCO) are yet to be established. This study aims to map the competence requirements for SCCOs. Semi-structured interviews were conducted with expert informants (n = 10) from four different backgrounds, including academia, regulatory, technology developers and other stakeholders, who were selected through a purposive sampling technique. Results revealed three key competences to develop: (i) System understanding, (ii) Communicational and technical knowledge, and (iii) Maritime competence. Knowledge of regulations, Navigational competence, and Basic engineering knowledge—will also be required. The discussion also highlighted the scope of new regulations and a manning plan for SCC. The author concludes that several modifications of the competence and training requirements will occur during the early functioning period of SSC depending on the technological advancement and operational experiences. [ABSTRACT FROM AUTHOR]

Transition-metal dichalcogenides intercalated with 3d-transition metals within the van der Waals (vdW) gaps have been the focus of intense investigations owing to their fascinating structural and magnetic properties. At certain concentrations the intercalated atoms form ordered superstructures that exhibit ferromagnetic or anti-ferromagnetic ordering. Here we show that the self-intercalated compound Cr1+δTe2 with δ ≈ 0.3 exhibits a new, so far unseen, three-dimensionally ordered (2×2×2) superstructure. Furthermore, high resolution X-ray diffraction reveals that there is an asymmetric occupation of the two inequivalent vdW gaps in the unit cell. The structure thus lacks inversion symmetry, which, thereby, allows for chiral non-collinear magnetic nanostructures. Indeed, Néel-type skyrmions are directly observed using Lorentz transmission electron microscopy. The skyrmions are stable within the accessible temperature range (100–200 K) as well as in zero magnetic field. The diameter of the Néel skyrmions increases with lamella thickness and varies with applied magnetic field, indicating the role of long-range dipole fields. Our studies show that self-intercalation in vdW materials is a novel route to the formation of synthetic non-collinear spin textures. Here, Saha et al. show that self-intercalation of e2Cr atoms in CrTe2 create an asymmetry in the number of atoms intercalated in the van der Waals gaps between the layers of CrTe2. This inversion symmetry breaking leads to non-collinear spin-textures and Néel-type magnetic skyrmions over a wide temperature range. [ABSTRACT FROM AUTHOR]

Objectives: To examine the pace of secular changes of selected body measurements and proportions of children and adolescents from Kolkata (India), between 1952–1966 and 1999–2011 in the context of differences between the sexes. Methods: The study group consisted of 7753 children, adolescents and young adults (7–21 years of age) included in two series of studies (1952–1966 and 2005–2011). The measurements included: body height, sitting height, biacromial and biiliocristal diameters, as well as body mass. Additionally, subishial leg length was derived. The pace of the observed intergenerational trends was estimated on the basis of the differences of the mean values of the analyzed characteristics between both cohorts and expressed as the change of a given parameter for a decade. Information regarding the educational and professional status of the parents of participants was obtained using a questionnaire. Results: In the majority of the analyzed characteristics, the pace of intergenerational changes was significantly higher among males, in comparison to females. It was visible especially during adolescence—between 11 and 19 years of age. The positive trends, especially, for characteristics such as body height or limb lengths occurred significantly quicker in males, in comparison to females. Conclusions: There were significant differences between the sexes in the pace of secular changes regarding the growth of the examined population. Considering the relatively homogenous economic situation of the families of the participants, it was more likely that those discrepancies effected from the social and domestic division of sexes, and the resulting differences in growth and development conditions. [ABSTRACT FROM AUTHOR]

This work presents a simple design procedure of a pressure compensator of a swash plate type variable displacement axial piston pump (VDAPP). The route of the work mainly focuses on static design through balancing the torque given by the pump pistons, rate cylinder and stroking cylinder on the swash plate during cut-in (maximum flow) and cut-off (minimum flow) pressure condition of the system with an objective of minimizing the output pressure ripples. The outcome in terms of pressure from the dynamic simulation of the designed compensator with pump has been compare with experimental result obtained from a reference commercial pump has compensator with duel spool. The model has been used for performance prediction for wide variations of the load valve area settings. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate inter-generational changes in selected mid-upper-arm measurements of boys from Kolkata, India. The analysis was based on the anthropometric measurements of two cohorts of Bengali boys aged 7-16 from middle-class families, in 1982-83 and 2005-11. The two cohorts were compared in terms of their mid-upper-arm circumference (MUAC) and mid-upper-arm area (MUAA), mid-upper-arm muscle area (MUAMA), mid-upper-arm fat area (MUAFA) and Arm Fat Index (AFI). The significances of the differences were determined using two-way ANOVA. All features differed significantly between the examined cohorts and all showed a general positive secular trend. In most cases, the biggest differences were noted for 14- and 16-year olds and the smallest for the youngest boys. The contemporary boys seemed to have more favourable overall developmental conditions, probably related to socioeconomic progress in India over recent decades. [ABSTRACT FROM AUTHOR]

The design and implementation of a real-time object motion sensing and trajectory replicating system, dependent on the image-based visual servoing capabilities of an electrohydraulic eye-in-hand parallel manipulator has been described in this paper. The tracking system consists of a monocular vision apparatus affixed to the top platform of a six-cylinder parallel manipulator constructed with industry grade double-acting single rod hydraulic actuators and budget proportional valves. The control algorithm is an amalgamation of three principles: machine vision based object tracking, image based visual servoing and actuator-level feedback control utilizing the inverse kinematics of the parallel manipulator. The real-time experiments are performed on a laboratory scale parallel manipulator setup with the aid of a virtual tracking object rendered on a computer monitor. The results for a few reference trajectories reveal that accurate tracking of target motions can be achieved with visual servoing algorithms designed for parallel manipulators in real-time. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the study was to investigate the intergenerational changes of upper and lower limb lengths as well as the values of the upper, lower limb, and intermembral indicators of children, adolescents, and young adults from Kolkata (India) between 1952 to 1966 and 2005 to 2011. Methods: The analysis was based on the results of anthropometric measurements of 7488 Bengali children, adolescents, and young adults. They were included in three cross‐sectional surveys, carried out in 1955 to 1966, 1982 to 1983 (only males), and 2005 to 2011. The upper and lower limb lengths were obtained and the upper and lower limb indicators, as well as an intermembral index, were calculated. The differences between the cohorts were assessed using two‐way ANOVA. Results: Positive, statistically significant, secular trends regarding the length of the lower and upper limbs as well as the value of the lower limb index were observed. Negative intergenerational changes were noted for the values of the upper limb indicator and intermembral index, suggesting that the secular increase of the length of the upper limbs was less pronounced than those of the body height and lower limbs length. Conclusions: The secular increase regarding the lower limbs length was associated with the socioeconomic progress of the country, but the length of the upper limbs was less sensitive for those factors. It is also important to mention that there is still very little information on those characteristics in general, which further proves the need for similar studies. [ABSTRACT FROM AUTHOR]

Conductivity, carrier mobility, and a suitable Gibbs free energy are important criteria that determine the performance of catalysts for a hydrogen evolution reaction (HER). However, it is a challenge to combine these factors into a single compound. Herein, we discover a superior electrocatalyst for a HER in the recently identified Dirac nodal arc semimetal PtSn4. The determined turnover frequency (TOF) for each active site of PtSn4 is 1.54 H2 s−1 at 100 mV. This sets a benchmark for HER catalysis on Pt‐based noble metals and earth‐abundant metal catalysts. We make use of the robust surface states of PtSn4 as their electrons can be transferred to the adsorbed hydrogen atoms in the catalytic process more efficiently. In addition, PtSn4 displays excellent chemical and electrochemical stabilities after long‐term exposure in air and long‐time HER stability tests. [ABSTRACT FROM AUTHOR]

The objective of the study was to analyse selected anthropometric features of children, adolescents and young adults from middle-class families in Kolkata, India, by BMI and adiposity categories. Standardized anthropometric measurements of 4194 individuals (1999 male and 2195 female) aged 7-21 were carried out between the years 2005 and 2011. The results were compared by BMI and adiposity categories. Statistical significance was assessed using two-way-ANOVA and linear regression analysis was performed. The study population could be differentiated in terms of BMI and adiposity categories for all examined anthropometric characteristics (p ≤ 0.001). After taking age into consideration, differences were observed for males in the case of body height and humerus breadth in BMI and adiposity categories, and for femur breadth in the case of adiposity categories. For females, differences were noted in body height measurements in BMI and adiposity categories, a sum of skinfold thicknesses in BMI categories, and upper-arm and calf circumferences in adiposity categories. The patterns of differences in the BMI categories were found to be similar to those in adiposity categories. The linear regression analysis results showed that there was a significant relationship between BMI and body fat ratio in the examined population. Underweight individuals, and those with low adiposity, were characterized by lower extremity circumferences and skeletal breadths. These features reached highest values in overweight/obese persons, characterized by high body fat. However, the differences observed between each BMI and adiposity category, in most cases, were only present in early childhood. [ABSTRACT FROM AUTHOR]

An innovative design procedure has been formulated by developing a mathematical model for the pressure compensator of an axial piston pump. The compensator provides energy saving by making the pump variable displacement type depending on the system load, thereby providing energy saving by better resource management. The procedure involves simple static design steps to ensure a balanced swiveling torque on the swash plate for specified cut-in and cut-off pressure limits. Adopting the basic pump model from the earlier works, the dynamic model of the pump has been updated by including the compensator dynamics. A design sensitivity analysis through dynamic simulation has been performed that corroborates the need of the design through torque balancing. Also, through dynamic simulation, tolerances of some critical dimensions have been identified. The pressure compensator model has been validated against experimental result obtained from a reference pump. [ABSTRACT FROM AUTHOR]

Tetragonal Heusler compounds that exhibit large perpendicular magnetic anisotropy are promising materials for advanced spintronic devices. A prerequisite are thin films whose tetragonal axis is oriented perpendicular to the plane of the films. Here we show that highly textured, (001) oriented, tetragonal Mn3Sn layers can be prepared using metallic zinc-blende (ZB) MnN as underlayers. Moreover, we show that these layers can be deposited on amorphous substrates using reactive magnetron sputtering. The ferrimagnetic Mn3Sn layers exhibit perpendicularly magnetized hysteresis loops with coercive fields of ∼2 T. Stoichiometric ZB-MnN underlayers share an "equivalent" Mn-Mn layer at the interface with Mn3Sn, thus promoting their oriented growth. Other nitride underlayers are not effective due to their rock-salt (RS) crystal structure and the absence of Mn. Density functional theory calculations confirm that tetragonal Mn3Sn Heusler films are energetically stable when interfaced with ZB-MnN underlayers and not with any of the other RS nitride underlayers considered here. Such Heusler compounds have much promise as electrodes for magnetic tunnel junction memory elements for deeply scaled magnetic random access memories. [ABSTRACT FROM AUTHOR]

A novel I-controller with antiwindup feature has been proposed as a tangent hyperbolic function of an integral of a sliding function. This has been combined with an input-linearized first-order sliding mode controller (SMC). A practical two-parameter sliding mode with integral controller (SMIC), design thus formulated has been adapted online by minimizing a Lyapunov functional together with constraining the parameter growth by projection operator. Keeping only the I-control live, but not adaptable, small sliding variable together with withholding discontinuous form of SMC has been proposed to eliminate chattering. Both from theoretical standpoint and through numerical simulation, the design is established as convergent. A set up actuated by an electrohydraulic valve–cylinder pair providing angular motion, typical of aircraft wing maneuvering system, has been realized and a real-coded genetic algorithm, together with offline experiments, has yielded the parameters for the system and the initial controller setting. Real-time experiments have clearly shown the SMIC to have tracking accuracy and bandwidth better than those achievable from some existing controllers. The proposed design has yielded chattering-free real-time responses for different external loading and motion demands. [ABSTRACT FROM AUTHOR]

The isotropic property at home configuration for a semi-regular Stewart platform manipulator with equal leg lengths has been found to be nonachievable by kinematic design optimization study. In this context, a new approach of design optimization has been formulated here for achieving semi-isotropicity through variable transformation that has rendered the constrained optimization over a finite workspace to infinite workspace in the transformed domain. The proposed minimization methodology of a positive definite function for all the angular and translational motion has exhibited strong convergence to zero for values of the design parameters that can be worked out as a closed-form solution only for the cases of linear translation. Finally, the variations of the condition number over the permissible range of all single-degree-of-freedom motions have been carried out. The absence of any other minima in the entire workspace has clearly established the home position as globally optimized. [ABSTRACT FROM AUTHOR]

Epitaxial thin films of ferromagnetic La0.7Sr0.3MnO3 (LSMO) and charge-ordered, antiferromagnetic Y0.5Ca0.5MnO3 (YCMO) were deposited on SrTiO3 (100) substrates by pulsed laser deposition (PLD). The heterostructure undergoes tetragonal distortion due to strong biaxial tensile strain imposed by the substrate. The LSMO-YCMO bilayers exhibit significant exchange bias (EB) across the interface even in a very small remnant magnetic field (∼5 Oe) present in the superconductor magnet. The unidirectional exchange anisotropy at the interface can be switched by reversing the polarity of the remnant magnetic field. [ABSTRACT FROM AUTHOR]

The physical model of an electrohydraulic actuation system with pressure-reducing cylinder end cushioning has been obtained. In order to arrive at the closure of the model, experimental models for actuator friction and the characteristics of the relief, non-return and proportional valves have been constructed. The variation in discharge through the proportional valve with both pressure and command signal has been modeled by training a neural network with experimental data. For the characterization of the discharge through the proportional valve, besides square root of the pressure drop in each metered orifice, polynomial forms of command signal for the discharge coefficients have been used. Such a direct characterization of the discharge with the command signal eliminates the orifice opening as an intermediate variable. A simple friction model that retains all the features of the existing complex models has been developed. Parameters such as maximum dynamic friction and the corresponding velocity have been introduced for this purpose. All these nonlinear subsystem models have been integrated together in MATLAB/Simulink frame to predict the actuation dynamics. The variations in the predicted and experimental displacements of the piston against different command signals have been found to be quite close to each other. [ABSTRACT FROM AUTHOR]

Electrohydraulic actuation systems with proportional valves and industry-grade cylinders have widespread use due to their low cost and ease of maintenance. Achieving good tracking of output position of the piston in such a system by a proper controller design is the objective of this study. Due to various parameter uncertainties and complex nonlinearities like piston friction, valve deadband and flow characteristics, the variation of oil property with working temperature and air entrapment volume, the implementation of a model-based control becomes quite difficult for such systems. A notable contribution of this work is to couple a model-free fuzzy controller with a feedforward controller with all the parameters estimated by a real-coded genetic algorithm. Also, the optimizer has been used for identifying an appropriate fuzzy structure that is easy to implement in real time. A comprehensive experimental study has revealed the best fuzzy structure to be achieved through a Gaussian fuzzification of linear combination of the position and velocity errors as the input and singleton membership function for the output voltage actuating the proportional valve. Excellent responses with good disturbance rejection capability and energy efficiency have been achieved. These responses have emerged superior to those achieved in a similar system with different controller structures and in systems with much costlier components. [ABSTRACT FROM AUTHOR]

High-resolution neutron powder diffraction is used to demonstrate that the Eu2+ moments in EuZrO3 are oriented along the c axis, in contrast to EuTiO3 where the moments lie within the ab plane. By applying a Landau theory analysis to the Ti and Zr system we are able to contrast the differing magnetoelectric coupling symmetries resulting from the magnetic space groups of the two ordered structures. The observed order parameter is consistent with the asymptotic three-dimensional Ising model. [ABSTRACT FROM AUTHOR]

An adaptive fuzzy-bias sliding-mode controller has been designed by adding biasing to an existing controller for motion tracking by an electrohydraulic system. The system has a proportional valve with large deadband and a cylinder with jump in static friction and nonlinear but continuous dynamic friction. While the biasing controller takes care of the discontinuous features, the fuzzy controller approximates the other system nonlinearities. The sliding-mode controller compensates the approximations. By a number of real-time experiments, the appropriate choices for the number of fuzzy rule base and some free parameters have been established. Then, starting with the same set of initial parameters for tracking step and sinusoidal demands of different frequencies, the responses have demonstrated sufficient adaptability of the controller. [ABSTRACT FROM PUBLISHER]

An electrohydraulic system with a proportional valve and industry-grade cylinder has been used to target the servoclass tracking performance. Such systems have a wide range of heavy-duty applications, where the environment could be quite dirty along with the demands becoming faster and more precise every day. High static friction in the cylinder and large deadband of the valve in the system pose control challenges that are more severe than in a system with a servovalve and a low-friction cylinder. A fuzzy-feedforward-bias controller has been developed and a genetic algorithm has been used to optimize the controller parameters. The real-time control experiments revealed excellent tracking throughout the cycle for sinusoidal displacements beyond 1.5 Hz. [ABSTRACT FROM PUBLISHER]

An aerostatic bearing has been designed for supporting a heavy payload. The bearing involves an axial gap on the stator top that provides an upward lift, a bottom gap for counterbalancing the tendency of large lift-off, and a feeding orifice at the bearing inlet that is connected with the gaps by a network of holes or inherences yielding the damping. Notable contributions of the work are proving the concept by numerical simulation through first-principle order-separated modeling and evolving a simple solution strategy. The predicted vertical motion dynamics of the payload reveals that, depending on the target range of the payload weight, alternatives could be free or choked orifice designs. [ABSTRACT FROM AUTHOR]

The spool valve is the key component of hydraulic control system, and the performance of spool valve depends on its leakage behaviour. Again, the leakage flow of spool valve is highly susceptible to valve uncertain dimensions, radial clearance and overlap or underlap. In the present work, the relative performance of critically lapped, underlapped and overlapped valves has been demonstrated in terms of leakage flow rate and pressure sensitivity about the metered ports. An approach to explore uncertain dimensions of the valve has been developed using CFD as an investigating tool. The comparison of CFD prediction against experimental results has also been carried out. It is found that the CFD predictions are in excellent agreement with the experimental results. [ABSTRACT FROM AUTHOR]

The potassium vanadium oxide-fluoride phase β-KVOF3 was prepared by in-situ reduction with hydrothermal methods and characterized by single-crystal X-ray diffraction and magnetic susceptibility measurements. The compound is orthorhombic [space group Pnma, a = 7.1596(2) Å, b = 7.5392(2) Å, c = 13.0506(4) Å, Z = 8]. The material is structurally similar and isoformulaic to d1 materials of formulae AVOF3 ( A+ = alkali metal, ammonium, or organic cation). Magnetic susceptibility data were successfully fit with a Heisenberg chain model. In-situ reduction of V5+ to V4+ during the hydrothermal reaction conditions was observed in the presence of Br- anions. The role of bromide ions in this reduction is explained and employed to reduce a d0 vanadium species to obtain a material with magnetic behavior. [ABSTRACT FROM AUTHOR]

Abstract: GaFeO3, AlFeO3 and related oxides are ferrimagnetic exhibiting magnetodielectric effect. There has been no evidence to date for ferroelectricity and hence multiferroicity in these oxides. We have investigated these oxides as well as oxides of the composition Al1−x−y Ga x Fe1+y O3 (x=0.2, y=0.2) for possible ferroelectricity by carrying out pyroelectric measurements. These measurements establish the occurrence of ferroelectricity at low temperatures below the Nèel temperature in these oxides. They also exhibit significant magnetoelectric effect. We have tried to understand the origin of ferroelectricity based on non-centrosymmetric magnetic ordering and disorder by carrying out first-principles calculations. [Copyright &y& Elsevier]

AlFeO3 and GaFeO3, which crystallize in a chiral orthorhombic (Pna21) structure, transform to a rhombohedral (R3c) structure when subjected to ball-milling. There is a distinct difference between the transformations of AlFeO3 and GaFeO3. AlFeO3 first transforms to an orthorhombic P212121 structure followed by its transformation to the R3c structure, while GaFeO3 goes directly to the R3c structure. The transformations have been characterized by X-ray diffraction and Raman spectroscopy. Magnetic properties of Pna21 and the transformed phases show significant differences. It is noteworthy that partial substitution of aluminum by gallium in AlFeO3 as in Al0.5Ga0.5FeO3 eliminates the intermediate P212121 phase, causing direct transformation of the Pna21 structure to the R3c structure. All of the transformations are thermodynamically first-order associated with significant changes in volume. We have used first-principles simulations to determine the pressure-dependent properties of AlFeO3 and GaFeO3 in orthorhombic and corundum structures and have estimated the critical pressures for the structural phase transition between the two structures. On the basis of this information, we also comment on the differences in the behavior of AlFeO3 and GaFeO3 under ball-milling. [ABSTRACT FROM AUTHOR]