Methods to Reproduce In-Plane Deformability of Orthotropic Floors in the Finite Element Models of Buildings

In the modelling of reinforced concrete (RC) buildings, the rigid diaphragm hypothesis to represent the in-plane behavior of floors was and still is very commonly adopted because of its simplicity and computational cheapness. However, since excessive floor in-plane deformability can cause a very different redistribution of lateral forces on vertical resisting elements, it may be necessary to consider floor deformability. This paper investigates the classical yet intriguing question of modeling orthotropic RC floor systems endowed with lightening elements by means of a uniform orthotropic slab in order to describe accurately the building response under seismic loads. The simplified method, commonly adopted by engineers and based on the equivalence between the transverse stiffness of the RC elements of the real floor and those of the orthotropic slab, is presented. A case study in which this simplified method is used is also provided. Then, an advanced finite element (FE)-based method to determine the elastic properties of the equivalent homogenized orthotropic slab is proposed. The novel aspect of this method is that it takes into account the interaction of shell elements with frame elements in the 3D FE model of the building. Based on the results obtained from the application of this method to a case study, a discussion on the adequacy of the simplified method is also provided

Methods to Reproduce In-Plane Deformability of Orthotropic Floors in the Finite Element Models of Buildings

In the modelling of reinforced concrete (RC) buildings, the rigid diaphragm hypothesis to represent the in-plane behavior of floors was and still is very commonly adopted because of its simplicity and computational cheapness. However, since excessive floor in-plane deformability can cause a very different redistribution of lateral forces on vertical resisting elements, it may be necessary to consider floor deformability. This paper investigates the classical yet intriguing question of modeling orthotropic RC floor systems endowed with lightening elements by means of a uniform orthotropic slab in order to describe accurately the building response under seismic loads. The simplified method, commonly adopted by engineers and based on the equivalence between the transverse stiffness of the RC elements of the real floor and those of the orthotropic slab, is presented. A case study in which this simplified method is used is also provided. Then, an advanced finite element (FE)-based method to determine the elastic properties of the equivalent homogenized orthotropic slab is proposed. The novel aspect of this method is that it takes into account the interaction of shell elements with frame elements in the 3D FE model of the building. Based on the results obtained from the application of this method to a case study, a discussion on the adequacy of the simplified method is also provided

An Educational Intervention to Train Professional Nurses in Promoting Patient Engagement: A Pilot Feasibility Study

Introduction: Growing evidence recognizes that patients who are motivated to take an active role in their care can experience a range of health benefits and reduced healthcare costs. Nurses play a critical role in the effort to make patients fully engaged in their disease management. Trainings devoted to increase nurses' skills and knowledge to assess and promote patient engagement are today a medical education priority. To address this goal, we developed a program of nurse education training in patient engagement strategies (NET-PES). This paper presents pilot feasibility study and preliminary participants outcomes for NET-PES. Methods: This is a pilot feasibility study of a 2-session program on patient engagement designed to improve professional nurses' ability to engage chronic patients in their medical journey; the training mainly focused on passing patient engagement assessment skills to clinicians as a crucial mean to improve care experience. A pre-post pilot evaluation of NET-PES included 46 nurses working with chronic conditions. A course specific competence test has been developed and validated to measure patient engagement skills. The design included self-report questionnaire completed before and after the training for evaluation purposes. Participants met in a large group for didactic presentations and then they were split into small groups in which they used role-play and case discussion to reflect upon the value of patient engagement measurement in relation to difficult cases from own practice. Results: Forty-six nurses participated in the training program. The satisfaction questionnaire showed that the program met the educational objectives and was considered to be useful and relevant by the participants. Results demonstrated changes on clinicians' attitudes and skills in promoting engagement. Moreover, practitioners demonstrated increases on confidence regarding their ability to support their patients' engagement in the care process. Conclusions: Learning programs teaching nurses about patient engagement strategies and assessment measures in clinical practice are key in supporting the realization of patient engagement in healthcare. Training nurses in this area is feasible and accepted and might have an impact on their ability to engage patients in the chronic care journey. Due to the limitation of the research design, further research is needed to assess the effectiveness of such a program and to verify if the benefits envisaged in this pilot are maintained on a long-term perspective and to test results by employing a randomized control study design

Semi-empirical model for shear strength of RC interior beam-column joints subjected to cyclic loads

This paper proposes an extension to RC interior beam-column joints of a model for the shear strength prediction of exterior joints under seismic actions, already presented in the literature and based, for certain assumptions, on a previous work of Park and Mosalam. The necessary changes, due to the joints\u2019 different physical configurations, only one beam converging in exterior joints and two beams converging in interior ones, are introduced. In the proposed model, on the basis of mechanical considerations, a direct formula for interior joint shear strength accounting for the resisting contributions of three inclined concrete struts and of joint reinforcements, the column horizontal stirrups and intermediate vertical bars, is derived. In comparison to the model for exterior joints, three struts are considered instead of two and the influenced of the upper column axial load on the inclination of the concrete struts is taken into account. The coefficients of the contributions of the struts and reinforcements are calibrated using 69 test data sets available in the literature, selecting only cyclic tests showing joint shear failure. For the validation of the proposed model, the shear strength predictions obtained using the proposed expression are compared with those obtained from Kassem\u2019s model, Wang et al.\u2019s formula and Kim and LaFave\u2019s formula, on a set of 28 specimens. It is also proposed a design formula, whose predictions are compared to those of Eurocode 8 and ACI Code

Recycling of multilayer packaging waste with switchable anionic surfactants

Switchable Anionic Surfactants (SAS) were used for delaminating flexible packaging waste composed of various plastic layers and aluminium, thereby promoting the recycling of such waste streams from a circular economy perspective. The delamination protocol was optimized on de-pulped food and beverage cartons containing low-density polyethylene (LDPE) and aluminium, varying the carboxylic acid and its counterion constituting the SAS (C8[sbnd]C18 carboxylic acids as the anionic part; inorganic bases and primary, secondary and tertiary amines as the cationic one) their molar ratio (carboxylic acid: base molar ratio from 1:1 to 1:3), SAS concentration (0.15, 0.3 and 0.5 wt%), time (0.5–3 h) and material weight in input (1–10 wt%). High-quality LDPE and aluminium were separated and recovered by using a diluted solution of a surfactant based on lauric acid and triethanolamine (C12-TEA), with performances not achievable with other anionic or cationic surfactants available on the market. The C12-TEA solution was then applied to a large variety of multilayer waste materials composed of polypropylene and aluminium, polyolefins/polyethylene terephthalate/aluminium, giving a material separation dependant on the structure and composition of the material in input. At the end of the process, lauric acid was recovered from the aqueous solution used for washing the separated materials by tuning its water solubility with CO2

The valuation of guaranteed lifelong withdrawal benefit options in variable annuity contracts and the impact of mortality risk

n light of the growing importance of the variable annuities market, in this paper we introduce a theoretical model for the pricing and valuation of guaranteed lifelong withdrawal benefit (GLWB) options embedded in variable annuity products. As the name suggests, this option offers a lifelong withdrawal guarantee; therefore, there is no limit on the total amount that is withdrawn over the term of the policy because if the account value becomes zero while the insured is still alive, he or she continues to receive the guaranteed amount annually until death. Any remaining account value at the time of death is paid to the beneficiary as a death benefit. We offer a specific framework to value the GLWB option in a market-consistent manner under the hypothesis of a static withdrawal strategy, according to which the withdrawal amount is always equal to the guaranteed amount. The valuation approach is based on the decomposition of the product into living and death benefits. The model makes use of the standard no-arbitrage models of mathematical finance, which extend the Black-Scholes framework to insurance contracts, assuming the fund follows a geometric Brownian motion and the insurance fee is paid, on an ongoing basis, as a proportion of the assets. We develop a sensitivity analysis, which shows how the value of the product varies with the key parameters, including the age of the policyholder at the inception of the contract, the guaranteed rate, the risk-free rate, and the fund volatility. We calculate the fair fee, using Monte Carlo simulations under different scenarios. We give special attention to the impact of mortality risk on the value of the option, using a flexible model of mortality dynamics, which allows for the possible perturbations by mortality shock of the standard mortality tables used by practitioners. Moreover, we evaluate the introduction of roll-up and step-up options and the effect of the decision to delay withdrawing. Empirical analyses are performed, and numerical results are provided

The small angle rear tracking detector of ZEUS

Abstract The design, construction, installation, and performance of the small angle rear tracking detector of the ZEUS experiment are described. The results on electron position measurement, electron energy correction, and background reduction at the first-level trigger are presented. The impact on the measurement of the proton structure function is discussed