Dynamic Response of Cantilever Retaining Walls Considering Soil Non-Linearity

For many decades the analysis of earth retaining structures under dynamic or seismic conditions has been carried out by means of standard limit equilibrium (Coulomb, M-O) or elastic methods (Wood, Veletsos and Younan). These approaches are simplified, as they make use of considerable approximations which are often applicable only under particular conditions. A different and perhaps more realistic approach is possible using established computer codes, which integrate numerically the governing equations of the soil and wall media. Since these problems may involve significant levels of strain in the backfill, material non-linearity should be taken into account to realistically simulate the response of the system. In the herein-reported study, a parametric analysis is carried out through the finite-difference code FLAC 5.0. Starting from simple cases involving elastic response, and moving gradually towards more realistic conditions, salient features of the dynamic wall-soil interaction problem are addressed. The case of non-linear hysteretic behaviour of soil and flexibility of wall is considered at a second stage. Results indicate that with increasing levels of acceleration, there is a clear transition from elastic behaviour (in which the aforementioned V-Y type methods are applicable), to plastic behaviour in which M-O methods are thought to be more suitable under pseudo-static conditions. The results of the parametric analyses are reported in terms of pertinent normalized parameters, to provide a general framework for the assessment of wall-soil dynamic interaction under strong seismic excitation

Performance assessment of ferrite- and neodymiumassisted synchronous reluctance machines

Growing attention towards environmental sustainability of energy conversion and stricter efficiency standards are encouraging the market penetration of high-efficiency electrical motors. Current regulations define international efficiency classes and the testing procedures for direct-on-line machines only, commonly induction motors. Synchronous reluctance machines are a valid alternative to the widely employed induction motors for variable-speed applications, due to their low manufacturing cost and higher efficiency. With proper design, torque ripple can be mitigated as much as to make rotor skewing unnecessary for most of applications. The low power factor downside can be fixed by inserting low-cost ferrite magnet into the rotor barriers, with benefits also on the torque capability and constant power speed range. The aim of this paper is to assess the performance and efficiency potential of one synchronous reluctance and two permanent magnet-assisted synchronous reluctance machine prototypes, obtained by replacing the rotor of a general-purpose induction motor with the said synchronous reluctance ones. The rotor barriers have been designed by means of a genetic optimization algorithm has and then adapted to insert commercially available magnets, compliant with minimum extracost requirements. The two prototypes were comprehensively characterized, to validate the design phase and to investigate the performance of the machines. The provided experimental results are critically examined and commented

Transient Overload Characteristics of PM-Assisted Synchronous Reluctance Machines, Including Sensorless Control Feasibility

Synchronous reluctance machines are a highefficiency alternative to induction motors for variable-speed applications. To mitigate the well-known downside of their lower power factor, permanent-magnet-assisted topologies, in which either rare-earth or ferrite magnets are inserted into the rotor in suitable quantities, are often adopted. The design and optimization procedures for PM-assisted topologies have been thoroughly discussed in the related literature. This paper compares synchronous reluctance machines assisted with NdFeB and ferrite magnets, focusing on torque overload capability and feasibility of saliency-based position estimation algorithms. Three prototypes were realized and tested. They all have the stator of a commercial induction motor and the same customdesigned synchronous reluctance rotor laminations. Of the three prototypes, one is a pure synchronous reluctance motor, and the other two have NdFeB and ferrite magnets, respectively; both are designed to give the same torque at rated current. Results from simulations and experiments are presented comparing the transient overload capability of the three machines, in terms of torque capability and de-magnetization limit. A dynamic thermal model of the machines was developed within this scope. Moreover, the feasibility of saliency-based sensorless methods was investigated and is presented here for the three machines, both at high- and low-current loads. The results of the paper suggest that the ferrite-assisted solution is the best candidate for replacing induction motors in variable-speed applications, for its optimal tradeoff between performance and cost

Living with phenylketonuria in adulthood: the PKU ATTITUDE study

Dietary treatment is the cornerstone of therapy for phenylketonuria (PKU), but adherence to low- phenylalanine diet progressively decreases after adolescence. We designed a survey to characterize the dietary habits of Italian adult PKU patients and to identify psychological factors influencing disease perception and adherence to diet. Participants to the survey (n = 111; response rate 94%) were asked to complete a structured questionnaire. Patients appeared to have an altered perception and awareness of the disease. About 40% of them did not consider PKU a disease and, despite declaring regular monitoring of phenylalanine levels (85%), nearly half of them reported a high plasma value over the last 6 months (>600 μmol/L, 48%) or were unable to specify it (31%). Adherence to PKU diet was unsatisfactory, with increased consumption of natural protein sources and reduced daily use of amino-acid supplements (<4–5 times/day in 82% patients). In addition to the intrinsic characteristics of AA formula (palatability, ease of use), the most important factor influencing their consumption was the increased social pressure associated with their use (55%). Plasma phenylalanine periodical measurements (61%) and examinations at metabolic centers (49%) were considered relevant for compliance to diet. In Italian adult PKU patients dietary management was found to be inadequate, likely due to inappropriate perception and knowledge of the disease, and lack of awareness of the negative impact of poor metabolic control in adult life. Clinicians should consider implementing more intense and tailored educational measures, as well as structured transitional care processes

Analysis and Detection of Electrical Aging Effects on High-Speed Motor Insulation

© 1972-2012 IEEE. The use of fast wide-bandgap devices in high-speed electrical drives with steep pulsewidth modulation voltage waveforms is the main cause of increased stress on the electric machine insulation system and consequently, of reduced reliability of the whole system. This represents a major concern in safety-critical applications, such as in the aerospace and electric transportation fields. The novel contribution of this work is to assess the effects of electrical aging on complex insulation systems (i.e., a whole stator winding) by analyzing easily measurable macroscopic quantities. To this purpose, an electrical aging procedure is defined, and the effects produced on three tested motors are presented. Three different analysis methods are adopted with the aim of assessing the damage caused to an ac motor winding by such steep voltage waveforms and hence to evaluate the state of aging of the insulation system

A mouse model for creatine transporter deficiency reveals early onset cognitive impairment and neuropathology associated with brain aging.

Mutations in the creatine (Cr) transporter (CrT) gene lead to cerebral creatine deficiency syndrome-1 (CCDS1), an X-linked metabolic disorder characterized by cerebral Cr deficiency causing intellectual disability, seizures, movement and autistic-like behavioural disturbances, language and speech impairment. Since no data are available about the neural and molecular underpinnings of this disease, we performed a longitudinal analysis of behavioural and pathological alterations associated with CrT deficiency in a CCDS1 mouse model. We found precocious cognitive and autistic-like defects, mimicking the early key features of human CCDS1. Moreover, mutant mice displayed a progressive impairment of short and long-term declarative memory denoting an early brain aging. Pathological examination showed a prominent loss of GABAergic synapses, marked activation of microglia, reduction of hippocampal neurogenesis and the accumulation of autofluorescent lipofuscin. Our data suggest that brain Cr depletion causes both early intellectual disability and late progressive cognitive decline, and identify novel targets to design intervention strategies aimed at overcoming brain CCDS1 alterations

Mean field theory of hard sphere glasses and jamming

Hard spheres are ubiquitous in condensed matter: they have been used as models for liquids, crystals, colloidal systems, granular systems, and powders. Packings of hard spheres are of even wider interest, as they are related to important problems in information theory, such as digitalization of signals, error correcting codes, and optimization problems. In three dimensions the densest packing of identical hard spheres has been proven to be the FCC lattice, and it is conjectured that the closest packing is ordered (a regular lattice, e.g, a crystal) in low enough dimension. Still, amorphous packings have attracted a lot of interest, because for polydisperse colloids and granular materials the crystalline state is not obtained in experiments for kinetic reasons. We review here a theory of amorphous packings, and more generally glassy states, of hard spheres that is based on the replica method: this theory gives predictions on the structure and thermodynamics of these states. In dimensions between two and six these predictions can be successfully compared with numerical simulations. We will also discuss the limit of large dimension where an exact solution is possible. Some of the results we present here have been already published, but others are original: in particular we improved the discussion of the large dimension limit and we obtained new results on the correlation function and the contact force distribution in three dimensions. We also try here to clarify the main assumptions that are beyond our theory and in particular the relation between our static computation and the dynamical procedures used to construct amorphous packings.Comment: 59 pages, 25 figures. Final version published on Rev.Mod.Phy

Disciplinary problems among high achiever students: the types and the causes

This qualitative study has been done to 24 teachers and 72 students from various secondary schools in Penang, Malaysia, in order to investigate the effect of between class ability grouping (BCAG) on high achiever secondary school students. Studies reported that BCAG triggered correspondence bias among teachers, which eventually affect them to show different perception and expectations towards high achiever classes (HAC) and low achiever classes (LAC) students. Symbolic interaction theories explained that individuals tend to be affected by others’ expectation, and therefore behave in a way they were expected to. Therefore, according to the previous studies on BCAG, it was assumed that HAC students would achieve better and would not be significantly involved in disciplinary problems. After semi-structured interview had been conducted in order to collect the data, and two-cycled analyses method, namely In-Vivo and Thematic Analyses had been operated in order to analyze the massive amount of qualitative data, the it was discovered that HAC students were involved with disciplinary problems, such as being disrespectful to teachers, paying less attention in the classroom, neglecting assignments and doing external work during classes. Other findings of this study showed that the disciplinary problems among HAC are related to their self-esteem types due to locus of control difference, as well as bigger issues apart from the competition among themselves. School management system, BCAG itself, reciprocal envy between HAC and LAC students, as well as their inclination towards tuition centers contributed to disciplinary problems among HAC students

Prognostic implications of functional mitral regurgitation according to the severity of the underlying chronic heart failure: A long-term outcome study

AimsTo examine the independent prognostic role of functional mitral regurgitation (FMR) and its impact across the severity of chronic heart failure (CHF) in a large population of outpatients with systolic CHF followed at two multidisciplinary clinics.Methods and resultsEchocardiography was performed upon enrolment in 469 CHF patients. Follow-up for death and heart transplant was updated on January 2007. Five-year transplant-free survival was 82.7 in patients with no or Grade I FMR, 64.4 in Grade II, 58.5 in Grade III, and 46.5 in Grade IV (P < 0.0001). There was a strong graded association between FMR and the long-term risk of death and heart transplant, which remained significant after multivariable adjustment (P = 0.0003). The association between FMR and events was strong and independent in patients with less severe symptoms and in those at lower overall risk based on a propensity score analysis, while it was not significant in patients with more advanced CHF or in the high-risk subgroup (P < 0.0001 for interactions).ConclusionThis study clarifies previous apparently discrepant results by demonstrating that FMR is an independent determinant of death and heart transplantation only in less severe CHF and in patients with a lower risk profile. This finding indicates that FMR plays a major role in the early phase of CHF, suggesting that this should be the focus of strategies attempting to reduce it. \uc2\ua9 The Author 2010

The Genetic Landscape of Complex Childhood-Onset Hyperkinetic Movement Disorders

Acord transformatiu CRUE-CSICThis work was supported by an NIHR Professorship (to M.A.K.). M.A.K. has received funding from the Sir Jules Thorn Award for Biomedical Research and Wellcome Trust. B.P.-D. was supported by Instituto de Salud Carlos III, PI 18/01319 and PI21/00248, and has received funding from Beca José Castillejos (CAS14/00328). K.J.P. was supported by an MRC Clinician-Scientist Fellowship (511015) and was supported by the Dystonia Medical Research Foundation and Fight for Sight. S.S.M. has received funding from the Winston Churchill Memorial trust and Cerebral Palsy Alliance.Background and Objective: The objective of this study was to better delineate the genetic landscape and key clinical characteristics of complex, early-onset, monogenic hyperkinetic movement disorders. Methods: Patients were recruited from 14 international centers. Participating clinicians completed standardized proformas capturing demographic, clinical, and genetic data. Two pediatric movement disorder experts reviewed available video footage, classifying hyperkinetic movements according to published criteria. Results: One hundred forty patients with pathogenic variants in 17 different genes (ADCY5, ATP1A3, DDC, DHPR, FOXG1, GCH1, GNAO1, KMT2B, MICU1, NKX2.1, PDE10A, PTPS, SGCE, SLC2A1, SLC6A3, SPR, and TH) were identified. In the majority, hyperkinetic movements were generalized (77%), with most patients (69%) manifesting combined motor semiologies. Parkinsonism-dystonia was characteristic of primary neurotransmitter disorders (DDC, DHPR, PTPS, SLC6A3, SPR, TH); chorea predominated in ADCY5-, ATP1A3-, FOXG1-, NKX2.1-, SLC2A1-, GNAO1-, and PDE10A-related disorders; and stereotypies were a prominent feature in FOXG1- and GNAO1-related disease. Those with generalized hyperkinetic movements had an earlier disease onset than those with focal/segmental distribution (2.5 ± 0.3 vs. 4.7 ± 0.7 years; P = 0.007). Patients with developmental delay also presented with hyperkinetic movements earlier than those with normal neurodevelopment (1.5 ± 2.9 vs. 4.7 ± 3.8 years; P < 0.001). Effective disease-specific therapies included dopaminergic agents for neurotransmitters disorders, ketogenic diet for glucose transporter deficiency, and deep brain stimulation for SGCE-, KMT2B-, and GNAO1-related hyperkinesia. Conclusions: This study highlights the complex phenotypes observed in children with genetic hyperkinetic movement disorders that can lead to diagnostic difficulty. We provide a comprehensive analysis of motor semiology to guide physicians in the genetic investigation of these patients, to facilitate early diagnosis, precision medicine treatments, and genetic counseling. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society