Search results for "LOAD"
showing 10 items of 1967 documents
Limit analysis of a beam in bending immersed in an elastoplastic medium
1968
The behavior of the beam-soil system is examined within the scope of the bilateral schematization of ideal elastoplastic bodies, in the following work stages; the expression for the limit load is supplied for each stage: Two peculiar features of the problem are highlighted:1) the “plastic hinge migration” phenomenon, due to the elastic unloading of the material, and2) the successive propagation of plastification in the soil which, being related to the displacement of the hinges in the beam, leads to the identification of the collapse mechanism of the systme.
Theorems of restricted dynamic shakedown
1993
Abstract Dynamic shakedown for a rate-independent material with internal variables is addressed in the hypothesis that the load values are restricted to those of a specified load history of finite or even infinite duration, thus ruling out the possibility—typical of classical shakedown theory—of indefinite load repetitions. Instead of the usual approach to dynamic shakedown, based on the bounded plastic work criterion, another approach is adopted here, based on the adaptation time criterion. Static, kinematic and mixed-form theorems are presented, which characterize the minimum adaptation time (MAT), a feature of the structure-load system, but which are also able to assess whether plastic w…
The shakedown load boundary of an elastic-perfectly plastic structure
1995
In the hypothesis of small displacements and combined time-variable/steady loads, the geometrical-mechanical properties of the shakedown load boundary are investigated. It is shown that, in the load space, the shakedown load boundary plays the role of yield surface, and that a certain plastic strain accumulation vector—characterizing some impending inadaptation collapse mechanism—obeys the normality rule, whereas a specific form of the maximum plastic work theorem constitutes an effective tool for the evaluation of the shakedown limit load corresponding to a specified inadaptation collapse mode. The equations governing the state of the structure at the shakedown limit are provided and the r…
Job Characteristics, Recovery Experiences and Occupational Well-being: Testing Cross-lagged Relationships across 1 Year
2013
The aim of the present study conducted among 274 Finnish employees was to examine the relationships between job characteristics, recovery experiences and occupational well-being across 1 year. We hypothesized that these relationships would follow normal causation, that is, job characteristics at T1 predict recovery experiences (detachment, relaxation, mastery and control at off-job time) and well-being (fatigue at work and work engagement) at T2, and recovery experiences at T1 predict well-being at T2. The structural equation modelling analyses lent support to the hypothesized normal causation model compared with the reversed causation and reciprocal models. However, only the longitudinal r…
Academic Workload, Workaholism e benessere individuale: uno studio esplorativo su effetti e conseguenze del sovraccarico lavorativo in accademia
2016
La cosiddetta "dipendenza da lavoro" sembra essere uno stato sempre più diffuso all'interno delle professioni ad alta responsabilità: sebbene essa sia in qualche modo giustificata, in quanto approvata socialmente e culturalmente, non va dimenticato che essa è pur sempre una situazione in grado, a lungo termine, di produrre stati di malessere diffusi nelle persone che ne sono coinvolte. Tale condizione di continuo e persistente stato di impegno professionale è tipico di coloro i quali lavorano presso strutture accademiche: esiste un interessante filone di ricerca che ha esplorato il persistente aumento di richieste lavorative che affligge il mondo accademico occidentale, e che sovrappone ad …
Cognition and interpersonal communication: The effect of voice quality on information processing and person perception
2014
Abstract Against the backdrop of cognitive load theory (CLT) it was tested if irregular voice increases processing demands on working memory (WM). An experiment was designed to expose N = 54 participants to expository text delivered with a modal and a creaky human voice. Working memory capacity was measured by a secondary task on the visual modality. Listening to a creaky voice quality consumes more cognitive capacity as indicated by the significant decrease in secondary task performance; also, retention of information was found to be impaired. Results are explained within the framework of CLT and implications for professional communication are discussed.
65 Science reboot. Creation of an evidence-based literature by increasing the use of regional languages in science
2019
Objectives English as an International Language is widely used in science. Unfortunately, scientific information space is oversaturated by using International Language, while Regional Languages remain informatively poor. The oversaturation leads to the information overload 1–4 , reducing the quality of information and data interpretation. At the same time, non-English speaking countries publish new studies in regional journals, causing contrary effect – information deficiency in English. 5 Similarly to RCSB PDB and NCBI, the authors suggest to create a novel scientific database in order to: - Enrich the regional languages allowing them to be competitive; - Concentrate on the evidence-based …
Synthesis and high-throughput testing of multilayered supported ionic liquid catalysts for the conversion of CO2 and epoxides into cyclic carbonates
2014
Multilayered covalently supported ionic liquid phase (mlc-SILP) materials were synthesised by grafting different bis-vinylimidazolium salts on thiol-functionalised silica. These materials, which contain a cross-linked oligomeric network of imidazolium units, were characterised and tested as catalysts for the reaction of carbon dioxide with various epoxides to produce cyclic carbonates. The materials prepared by supporting a bis-imidazolium iodide salt with xylene or octane as a linker between the imidazolium units were identified as the most active catalysts and displayed high turnover numbers and improved productivity compared to known supported ionic liquid catalysts. The most promising m…
Unravelling [3+2] Cycloaddition Reactions through the Molecular Electron Density Theory
2018
Después de la primera clasificación de las reacciones 32CA en reacciones de tipo zw y pr, establecidas en el año 2014, la estructura y reactividad de los TACs más importantes utilizados en las reacciones 32CA ha sido completamente caracterizado en base a la MEDT propuesta recientemente. Entre la gran cantidad de trabajo desarrollado a lo largo de la presente tesis doctoral, se han seleccionado y discutido ocho publicaciones representativas, que permitieron caracterizar dos nuevos tipos de reactividad y consolidar la reactividad original de tipo zw. Así, dependiendo de las cuatro estructuras electrónicas diferentes de los TACs, es decir, pseudodiradical, pseudoradical, carbenoide y zwitterió…
Perfluoroketene dithioacetals and perfluorodithiocarboxylic acid derivatives: Versatile tools for organofluorine synthesis
2007
Perfluoroketene dithioacetals are simple and versatile compounds that can be transformed into a large variety of trifluoromethyl derivatives, in particular aza- and thiaheterocycles, perhalodithiocrotonic esters, and fluorinated dithiol thiones. These unsaturated perfluorodithioesters and analogs give interesting polar cycloaddition reactions whose mechanism is strongly influenced by the fluorine substitution. This substitution plays an important role in the reactivity of saturated perfluorodithiocarboxylic acids as well. Except for the carbophilic addition of allyl Grignard reagents to perfluorocarboxamides, a domino thiophilic addition-fluoride elimination was the main reaction process. I…