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Composite leaf springs represent a key application of composite materials in the field of automotive lightweight materials. Stiffness, as a critical parameter of composite leaf springs, is closely related to the handling stability and ride comfort of automobiles. Therefore, this paper proposes an explicit theoretical model, which can consider the anisotropy of composite materials and detailed structure of the leaf spring, to predict the stiffness based on the law of energy conservation. The obtained results are verified against the results of the finite element method and bench test of basalt/epoxy samples. Moreover, the influence of the relevant design parameters on the stiffness is analyzed to provide guidance for the stiffness matching of composite leaf springs. The thickness of the composite leaf spring considerably influences its stiffness. As a key parameter representing the bearing capacity, the strength is closely related to the reliability of leaf springs. Based on the Tasi-Wu strength failure criterion, the influence of the relevant design parameters on the strength ratio of a composite leaf spring is analyzed under the constraint of stiffness. An increase in the width of the composite leaf spring enhances its bearing capacity when the stiffness is required to be within a certain range.

In this paper, a theoretical model based on the electric field integration method is proposed to analyse radiation properties of the slotted annular Leaky-Wave Antenna (LWA), which can generate a Circularly Polarized (CP) conical beam or broadside beam. The annular LWA contains radiating elements arranged along a circular travelling-wave structure with equal intervals. By combining the proposed model and LWA theory, the design procedure for the annular SIW LWA is presented. To verify the model, three examples of LWAs with different beam angles have been designed and fabricated. Calculation results from the proposed model are consistent with the simulation and measurement results. The model can significantly reduce the design period and is an instructive tool for antenna design.

This paper constructs a partial equilibrium model under public health emergency shocks based on economic growth theory, and investigates the relationship between government intervention and virus transmission and economic growth path. We found that both close contacts tracing measures and isolation measures are beneficial to human capital stock and economic output per capita, and the effect of close contact tracing measures is better than that of isolation measures. For infectious diseases of different intensities, economic growth pathways differed across interventions. For low contagious public health emergencies, the focus should be on the coordination of isolation and tracing measures. For highly contagious public health emergencies, strict isolation, and tracing measures have limited effect in repairing the negative economic impact of the outbreak. The theoretical model provides a basic paradigm for the future researches to study economic growth under health emergencies, with good scalability and robustness.

Breaks in the so-called “continuous” (unspliced) belt sections, and not in the spliced areas, are infrequent but do happen in practice. This article presents some aspects, which may account for such breaks in conveyor belts. It indicates the so-called “sensitive points” in design, especially in the transition section of the conveyor belt and in identifying the actual strength of the belt. The presented results include the influence of the width of a belt specimen on the identified belt tensile strength. An increase in the specimen width entails a decrease in the belt strength. The research involved develops a universal theoretical model of the belt on a transition section of a troughed conveyor in which, in the case of steel-cord belts, the belt is composed of cords and layers of rubber, and in the case of a textile belt, of narrow strips. The article also describes geometrical forces in the transition section of the belt and an illustrative analysis of loads acting on the belt. Attention was also devoted to the influence of the belt type on the non-uniform character of loads in the transition section of the conveyor. A replacement of a conveyor belt with a belt having different elastic properties may increase the non-uniformity of belt loads in the transition section of the conveyor, even by 100%.

Background Zika virus (ZIKV) infection caused outbreak in Brazil, in 2015 and 2016. Disorganized urban growth, facilitates the concentration of numerous susceptible and infected individuals. It is useful to understand the mechanisms that can favor the increase in ZIKV incidence, such as areas with wide socioeconomic and environmental diversity. Therefore, the study analyzed the spatial distribution of ZIKV in the city of Rio de Janeiro, Brazil, in 2015 and 2016, and associations between the incidence per 1000 inhabitants and socio-environmental factors. Methods The census tracts were used as the analytical units reported ZIKV cases among the city’s inhabitants. Local Empirical Bayesian method was used to control the incidence rates’ instability effect. The spatial autocorrelation was verified with Moran’s Index and local indicators of spatial association (LISA). Spearman correlation matrix was used to indicate possible collinearity. The Ordinary Least Squares (OLS), Spatial Lag Model (SAR), and Spatial Error Model (CAR) were used to analyze the relationship between ZIKV and socio-environmental factors. Results The SAR model exhibited the best parameters: R2 = 0.44, Log-likelihood = − 7482, Akaike Information Criterion (AIC) = 14,980. In this model, mean income between 1 and 2 minimum wages was possible risk factors for Zika occurrence in the localities. Household conditions related to adequate water supply and the existence of public sewage disposal were associated with lower ZIKV cumulative incidence, suggesting possible protective factors against the occurrence of ZIKV in the localities. The presence of the Family Health Strategy in the census tracts was positively associated with the ZIKV cumulative incidence. However, the results show that mean income less than 1 minimum wage were negatively associated with higher ZIKV cumulative incidence. Conclusion The results demonstrate the importance of socio-environmental variables in the dynamics of ZIKV transmission and the relevance for the development of control strategies.

PurposeThe purpose of this paper is twofold. First, it highlights the emergence of Generation Z and the interface of its members with the tourism system. Second, by way of a theoretical model, the paper provides a more holistic approach to understanding Generation Z travel experiences in which the emphasis is shifted from the destination to the traveller. This is in keeping with the trend which lays more emphasis on people rather than landscape.Design/methodology/approachThis is qualitative research founded on an interpretive (constructivist) paradigm. Selecting Generation Z as the subject locates this study under generational theory and assumesprima faciea socially constructed reality. The paper is based on research conducted in New Zealand aimed at understanding the travel experiences of inbound Generation Z travellers. Data were collected from 12 semi-structured interviews lasting about 30 min each and from 5 blogs. Nvivo 11 programme was used in analysing data and developing themes. Core categories and related themes were generated forming building blocks of a theoretical model.FindingsFindings revealed interplay of multiple factors in Generation Z’s travel experiences at a destination. The factors are global in nature, destination centric and those which are immediate or proximate to the individual. To fully grasp the notion of experience requires the gestalt of the three as well as pre-trip, during-trip and post-trip factors.Research limitations/implicationsThe impact of significant events upon participants is assumed. A specific analysis of the events and the magnitude of their influence on the individual participants may be necessary.Practical implicationsDestination marketers tend to concentrate on psychological aspects to appeal to the traveller. The focus, in this case, is creating an attractive image in the mind of travellers to get them to come to the destination. This research suggests shifting the focus to understanding the evolving traveller.Social implicationsGovernments and tourism purveyors may require an ever-increasing budget to map out strategies to meet the continuously morphing needs of the future traveller. The constantly evolving global environment necessitates greater flexibility in institutional framework with less bureaucratic bottlenecks.Originality/valueGeneration Z is a relatively new entrant into the tourism market which makes this research relevant and timely. The paucity of academic literature on a generation which is contemporaneously in its “highly influenceable” period of life and entering adulthood in an increasingly changing world is further credence for this research. A more holistic theoretical model to understanding Generation Z travel experience is proposed.

Sexting, defined as the exchange of sexually explicit contents among adolescents and young adults using electronic media, has become a popular topic of interest in the wider public. This paper proposed a theoretical model to explain motivational determinants of sexting behaviour. We reviewed sexting literature to show how multiple empirical confirmed motivational factors can be modelled within our framework. By analysing empirical research, we posited a set of individual characteristics and contextual characteristicsthat explain sexting behaviour. We offered a systematic review of motivational determinants relevant to capture sexting behaviour and guidelines for future research in this area. We intended by this theory to organize prior research into a more theoretically satisfying approach to study sexting and to encourage researchers to expand the model and use it in future studies., Seksting, definiran kao razmijena seksualno eksplicitnog sadržaja elektroničkim medijima među adolescentima i mladim osobama, aktualna je tema šire javnosti. U ovom je radu predložen teorijski model koji objašnjava motivacijske odrednice sekstinga. Autori su na temelju pregleda do sada provedih istraživanja prikazali kako se više empirijski potvrđenih motivacijskih čimbenika može integrirati u predloženi model. Konkretno, analizom su empirijskih istraživanja autori postavili set individualnih i kontekstualnih karakteristika koje objašnjavanju ponašanje kakvo upućuje na seksting. Predložen je sistematski pregled motivacijskih determinanti relevantnih za razumijevanje sekstinga ismjernice za buduća istraživanja u ovom području. Namjera je ovog modela organizacija rezultata do sada provednih istraživanja u teorijski prihvatljiv pristup s ciljem daljnjeg proučavanja sekstinga te poticanje istraživača na dodatni razvoj modela i njegovu primjenu u budućim istraživanjima.

In order to ensure the safety and reliability of the horizontal brace of semi-submersible platform (SEMI) which functions as the supporting structure in SEMI, this article presents an elastic-plastic method to analyze the variations of the crack tip opening displacement, elastic zone and plastic zone of the cracked section of the horizontal brace under beam wave. The brace of the SEMI was assumed to be located a circumferential through crack at its boundary in this article. In addition, the cracked section of the brace has been divided into crack zone, tensile plastic zone, elastic zone and compressive plastic zone in the presented theoretical model. Moreover, the closed form of the solution has been found in this article which is especially suitable solving complicated problems in practical engineering application. Also, a typical new-generation SEMI that is in practical use was selected to analyze the variation tendency of the cracked brace’s parameters using the proposed model which could give good suggestion to semi-submersible platform designers and managers.

Contains fulltext : 219511.pdf (Publisher’s version ) (Open Access) Purpose: The aim of this article is to conceptualise the phenomenon of therapy-related parental stress in parents of children with a physical disability. Methods: Three models related to parental stress were reviewed, i.e., general parental stress, burden of caregiving in parents of children with physical disabilities, and experiences of these parents with their child's therapy. Results: The proposed definition of therapy-related parental stress is "the subjective stress and subsequent changes of functioning and health experienced by a parent of a child with a physical disability in response to paramedical therapies (i.e., physical, occupational, and/or speech and language therapy)". A theoretical model is proposed to describe the process of therapy-related parental stress. Available questionnaires will most likely not be valid and responsive to capture the (changes in) stress parents experience related to therapy their child receives. Conclusions: This article provides a first definition of therapy-related parental stress and a theoretical model to visualise the processes with regard to this topic. Empirical testing of the presented components and their coherence is needed to confirm or improve the model. A questionnaire that specifically measures the concept of therapy-related parental stress is needed, along with evaluating therapy-related parental stress in clinical practice and research.Indications for rehabilitation It is imperative to recognise paramedical therapies (i.e., physical, occupational, and speech and language therapy) as a potential stressor for parents of children with a physical disability, both in paediatric rehabilitation practice and research. A definition and theoretical model of therapy-related parental stress is proposed and the need for measures to evaluate this phenomenon is argued. The authors provide a starting point for the evidence base of the concept of therapy-related parental stress. 8 p.

Typically, panel-to-panel and panel-to-foundation connection zones in Cross-Laminated Timber (CLT) walls consist of steel-to-timber mechanical connections (hold-downs and angle-brackets) and timber-to-timber contact. While hold-downs and angle brackets are extensively studied in literature, the role of timber-to timber contact is underestimated. The platform constructional technology used for build CLT walls requires that the vertical timber panels compresses the horizontal CLT floors, engaging the orthogonal to grain timber properties in the seismic response. This paper discusses a new development concerning a theoretical sectional model for CLT panels proposed by the authors in a recent work, where strength of the panels subjected to combined axial force and bending moment was studied accounting for orthogonal to grain timber properties. As advancement, a theoretical moment-curvature model for CLT panels is proposed in this paper and the displacement capacity (i.e., ductility) is investigated. The main parameters which affect the ductile behavior of the panels have been studied by means of parametric analyses, i.e. varying cross-section dimensions, amount of axial force, and hold-downs resistance. Theoretical results have been also compared with numerical ones derived from a bi-dimensional finite element model developed by the authors and a good matching between the results has been highlighted.

Research background. The electronic environment has become an integral part of today’s marketing environment. The transformation of information technology makes it possible to reach the desired customer through various business instruments, regardless of his location. The number of consumers using the Internet to search for goods and services is increasing. As a result, social networks are gaining in importance from both businesses and consumers. There are currently over 800 social networks in the world. Corporate social networking accounts where a variety of news can be posted: from company start-up history to the latest company prototype news, and often for small businesses, and represents the cost of the website. Most authors point out that the scope of e-marketing is wider than online marketing because online marketing refers only to the Internet. Businesses seek to disseminate information about goods through social networks, given their popularity and impact on consumers. Purpose of the article is to construct the theoretical model that would help to determine how the impact of social networks on online marketing of companies can be assessed. Methods: analysis of scientific literature, systematization, generalization. Findings and Value added. Based on the model, proposed by the authors, the elements of Internet marketing are analyzed, as well as research on the importance of social networks in information transfer and communication with the consumer is emphasized and the most commonly used indicators of social networks are singled out.

It is becoming clear that post-traumatic stress disorder (PTSD) is not simply a psychiatric disorder, but one that involves pervasive physiological impairments as well. These physiological disturbances deserve attention in any attempt at integrative treatment of PTSD that requires a focus beyond the PTSD symptoms themselves. The physiological disturbances in PTSD range over many systems, but a common thread thought to underlie them is that the chronic effects of PTSD involve problems with allostatic control mechanisms that result in an excess in what has been termed “allostatic load” (AL). A pharmacological approach to reducing AL would be valuable, but, because of the large range of physiological issues involved – including metabolic, inflammatory, and cardiovascular systems – it is unclear whether there exists a simple comprehensive way to address the AL landscape. In this paper, we propose that the cannabinoid system may offer just such an approach, and we outline evidence for the potential utility of cannabinoids in reducing many of the chronic physiological abnormalities seen in PTSD which are thought to be related to excess AL.

Design Thinking (DT) has been chosen as an approach to support problem-solving by many software development companies. However, there are divergences between the professionals of these companies concerning which techniques are performed, which steps are followed, and the way to implement this approach, as it proposes itself, to be divergent to generate numerous alternatives and, also, convergent, to find a solution. As a practical way to apply DT in software development, a collection of techniques are implemented during different working spaces provided by the DT models. Therefore, selecting the appropriate techniques within the set of the available ones is challenging. Aiming to present a solution for helping software development professionals in how to select the appropriate techniques for DT activities, we propose the development of a theoretical context-based recommendation model for selecting DT techniques for software development. Thus, we aim to develop a recommender and collaborative system of DT techniques and to validate it through industry-based empirical studies. We have already characterized the DT techniques that professionals are using and how they select them, and the benefits and challenges of using DT. These results were used to inform the proposal and the validation of a first version of the DT techniques recommendation tool, which presents the tool first round of core features.

This paper presents a multi-objective optimization strategy for pump-as-turbines (PAT), which relies on one-dimensional theory and analysis of geometrical parameters. In this strategy, a theoretical model, which considers all possible losses incurred (mainly by the components of pipe inlet, impeller and volute), has been put forward for performance prediction of centrifugal pumps operating as turbines (PAT). With the established mathematical relationship between the efficiency of PAT (both at pump and turbine mode) and the impeller controlling variables, the geometric optimization of the PAT impeller is performed with constant rotational speed. Specifically, the optimization data consist of 50 sets of impellers generated from Latin Hypercube Sampling method with its corresponding efficiencies calculated. Subsequently, the pareto-based genetic algorithm (PBGA) was adopted to optimize the geometic parameters of the impellers through the theoretical model. To validate the theoretical optimization results, the high-fidelity Computational Fluid Dynamics (CFD) simulation and the experimental data are employed for comparison of the PAT performance. The findings show that the efficiencies of both the pump and PAT optimized variables increased by 0.27% and 16.3% respectively under the design flow condition. Based on the one-dimensional theoretical optimization results, the geometry of the impeller is redesigned to suit both pump and PAT mode operations. It is concluded that the chosen design variables (b2, &beta, 1, &beta, 2, and z) have a significant impact on the PAT efficiency, which demonstrates that the optimization scheme proposed in this study is practicable.

Purpose - The importance of developing theoretical models and their empirical validation, capable of explaining safety performance within organizations, has been pointed out by the scientific community. Fernandez-Mulliz, Montes-Peon, and Vazquez-Ordaz (2007) proposed a model that integrates dimensions considered as determinants of safety culture to explain safety performance, which was tested with Occupational Health and Safety technicians of Spanish companies. This study aims to verify if that theoretical model obtains empirical support in the Portuguese context, considering the supervisors' perspective. In addition, it also aims to contribute to the adaptation of the measurement instrument, which allowed for the empirical test of the model in the Portuguese context.Design/methodology/approach - The study conducted is quantitative with a cross-sectional study design. In total, 174 supervisors at different levels of supervision, in different Portuguese companies from different activity sectors, participated in the study. Data were gathered through the Portuguese version of the instrument developed by the authors of the model (Fernandez-Muniz et al., 2007).Findings - The results partially confirm the proposed model wherein supervisors play a determinant role in the development of safety culture and thus in the safety performance of organizations.Originality/value - This study addresses one of the demands present in the literature, having empirically tested a model that aims to explain the safety performance of organizations, expanding its application to the management perspective and to a different national context. The results emphasize the role supervisors may play in the development of safer organizations., (undefined)

Strands produced from small-diameter timbers of lodgepole and ponderosa pine were used to fabricate a composite sandwich structure as a replacement for traditional building envelope materials, such as roofing. It is beneficial to develop models that are verified to predict the behavior of these sandwich structures under typical service loads. When used for building envelopes, these structural panels are subjected to bending due to wind, snow, live, and dead loads during their service life. The objective of this study was to develop a theoretical and a finite element (FE) model to evaluate the elastic bending behavior of the wood-strand composite sandwich panel with a biaxial corrugated core. The effect of shear deformation was shown to be negligible by applying two theoretical models, the Euler&ndash, Bernoulli and Timoshenko beam theories. Tensile tests were conducted to obtain the material properties as inputs into the models. Predicted bending stiffness of the sandwich panels using Euler-Bernoulli, Timoshenko, and FE models differed from the experimental results by 3.6%, 5.2%, and 6.5%, respectively. Using FE and theoretical models, a sensitivity analysis was conducted to explore the effect of change in bending stiffness due to intrinsic variation in material properties of the wood composite material.

Objective: To propose a theoretical model based on nine drivers of service innovation (organizational culture, strategies, research and development, employees, technological trajectory, institutional trajectory, competitors, consumers, and suppliers) in order to comprehend the phenomenon. Originality/value: Given its recent empowerment and the manufacturing focus it has initially received, service innovation still lacks models that seek to comprehend the phenomenon within an encompassing and particular framework. The originality of this study arises from this issue. Design/methodology/approach: The method consists of a multiple case study. We used semi-structured interviews with strategic hospital managers and documental research with an analysis of accounting balances, organograms, and other documents. We addressed the cases from a systemic perspective in order to permit comparison within the same structure. Results: The model permitted us to recognize that the analyzed hospitals were having difficulty innovating, as shown by some characteristics found through the drivers that were proposed by this study. More specifically, the hospitals follow a unidimensional and outdated concept of innovation; that is, they consider innovation in services to be the adoption of technologies from the industry, as shown by Barras (1986). There are also no strategic innovation programs. RESUMO Objetivo: Propor um modelo teórico suportado em nove drivers da inovação em serviços (cultura organizacional, estratégias, pesquisa e desenvolvimento, capital humano, competidores, clientes, fornecedores, trajetória tecnológica, trajetória institucional) para compreender o fenômeno. Originalidade/valor: Dado o seu recente protagonismo e pelo enfoque manufatureiro inicialmente recebido, a inovação em serviços ainda carece de modelos que busquem compreender o fenômeno dentro de um framework abrangente e particular. A originalidade do trabalho surge dessa problemática. Design /metodologia/abordagem: O método consiste em um estudo de casos múltiplos. Para sua execução, utilizaram-se entrevistas semiestruturadas com gestores estratégicos de hospitais, além de pesquisa documental com a análise de balanços contábeis, organogramas, entre outros. Para a análise dos resultados, utilizou-se a compreensão dos casos em uma perspectiva sistêmica, por meio da síntese de casos cruzados, permitindo a comparação de casos em uma mesma estrutura. Resultados: O modelo permitiu identificar que os hospitais em análise apresentam dificuldades para inovar, dadas algumas características levantadas a partir dos drivers propostos por este trabalho. Mais especificamente, os hospitais possuem conceito unidimensional e defasado da inovação, isto é, consideram a inovação em serviços como a adoção das tecnologias oriundas da indústria, tal qual se considerava com Barras (1986), além de inexistirem programas estratégicos de inovação.

The aim of this study is to introduce the development of the Chinese Assessment and Evaluation of Physical Literacy (CAEPL), to present the theoretical model of the CAEPL, and to quantify the weight of each domain of the CAEPL. 34 experts took part in the Delphi survey, and 23 experts completed all the three rounds of the survey. Experts’ opinions are used to develop the theoretical model of the CAEPL. The analytical hierarchy process (AHP) was employed for determining the weights of subdomains and items of the CAEPL. The CAEPL is a comprehensive model, including intention of physical activity (IPA), knowledge of physical activity (KPA), motor/sport skill (MSS), behavior of physical activity (BPA) and physical fitness (PF). Specific weights of IPA, KPA, MSS, BPA and PF are 17.25%, 16.23%, 27.01%, 23.72% and 15.79%, respectively. The CAEPL provides an important and useful instrument to measure and improve physical literacy (PL) among young Chinese people. Studies on the feasibility, reliability, validity and sensitivity of the CAEPL should be conducted to improve it in the future.

This paper is an attempt to advance research on walking at a neighborhood level of analysis for people with disabilities by proposing a theoretical model that combines the knowledge of two disciplines: traffic planning and environmental psychology. The aim is to provide guidance for a discussion and a plan for future interdisciplinary investigations by proposing a model that accounts for the dynamic interaction between environmental characteristics, human processes, and walking experience among individuals with a disability. For this purpose, traffic planners, and environmental psychologists came together to discuss theories, concepts, and thematic relevance in a series of focus group meetings. These meetings led to the selection of the Human Environment Interaction (HEI) model, originally developed from the field of environmental psychology and operationalized to describe how walking experiences result from the interplay between individual abilities, emotional processes, and the physical and social characteristics of the environment (Kuller, 1991). The proposed model aims to sustain interdisciplinary discussion and research planning around the topic of neighborhood walking for people with disabilities. By operationalizing each dimension in the model, a good fit between groups with disabilities and individual differences associated with walking experiences is assumed, which, in turn, will have the potential to provide a more conscious analysis of wellbeing-related outcomes, such as usability of the environment, frequency of mobility, and quality of life. However, to improve understanding of urban walking at a neighborhood level for people with disabilities, empirical studies must be carried out to test the proposed model.

An economical way to harvest tidal energy is by integrating free stream turbines in coastal infrastructure. While numerous studies have investigated how turbines should be arranged in idealized geometries to optimize their performance, only a few have considered the influence of realistic bed features. This research investigates the influence of a hydraulic structure on the performance of a tidal turbine, using the combination of field monitoring of full scale turbines installed in a Dutch storm surge barrier - comprising a weir and pillars - and by developing a corresponding theoretical model. The observed production by the turbines was large compared to situations with an unconstrained flow for two reasons. Firstly, the flow contraction by the weir increased the mass flux through the rotor plane. Secondly, the turbine suppressed energy losses in the recirculation zone downstream of a weir. The proposed model provides a quantitative estimate of these effects and is validated against field data. The model can be used as a design tool or parametrization of turbines in a large scale shallow water model, providing performance estimates covering a range of turbine-weir configurations. The work contributes to efficiently exploiting tidal energy with turbines in coastal bridges or flood defenses.

The burst pressure of steel reinforced flexible pipe (SRFP) considering plasticity is investigated through experimental, theoretical and numerical methods. The results obtained from the aforementioned methods are in good agreement with each other, which illustrates the accuracy and reliability of the proposed theoretical and numerical models. The mechanical responses of PE layers and the steel strips are studied in detail, and the rationality of the strain uniformity assumption for the steel strip's cross section in the theoretical model is confirmed from its von Mises stress variation along the width at different points in FEM. Some influential parameters of SRFP on the burst pressure are also investigated in order to guide its cross-section design. The theoretical model and the FEM proposed in this paper can not only give an estimation to the safety and reliability of the pipe when it is subjected to internal pressure, but can also provide some reference for improving and optimizing its cross-section design.

Fabric Reinforced Cementitious Matrix (FRCM) systems have been recently introduced for repairing or strengthening interventions of reinforced concrete and masonry structures. Thanks to the combination of a dry grid of fibers and a cement-based material (matrix), they present a good strength and numerous advantages with respect to traditional Fiber Reinforced Polymer (FRP) systems. The tensile and bond behavior of FRCM reinforcement systems is characterized by specific phenomena influencing their performance, which are generally not observed in the case of FRP, and that are still object of experimental and numerical studies. Aim of the present paper is the proposal of a theoretical model for numerically studying the tensile behavior of FRCM systems, able to consider the different phenomena characterizing the response of FRCM in tension. The model is carried out on the basis of equilibrium considerations by introducing both linear and nonlinear laws for schematizing the local behavior at the level of the matrix, reinforcement and reinforcement/matrix interface. The model is presented in detail in the first part of the paper and, in the second part, it is applied to an experimental case study derived from literature.

This article describes my more than four decades of not so straightforward journey through mathematical chemistry and QSAR research with descriptions of some valuable personal interactions and collaborations with Professors Milan Randić and Mircea Diudea. This work is licensed under a Creative Commons Attribution 4.0 International License.

The beneficial effect provided by external Fiber-Reinforced Polymers (FRP) confinement on the compressive behaviour of masonry columns has been widely demonstrated by experimental results. Conversely to FRP-confined concrete, for which some reliable stress–strain theoretical models have been developed, in case of confined masonry any unified model has been yet provided. In this paper, after the elaboration of a database containing experimental results on FRP-wrapped masonry columns tested under axial loads, new design-oriented stress–strain constitutive relationships for FRP-confined masonry are proposed. These laws—which have general validity for whatever confined masonry—were derived from the existing Lam and Teng’s model originally developed for FRP-confined concrete, and here adapted to confined tuff masonry. Two functions rule the shape of theoretical stress–strain curve: a second order parabola defines the elastic behaviour, while a straight-line describes the post-elastic behaviour. The entire axial stress–strain response is completely defined by unconfined masonry mechanical properties, composite material characteristics and by a single unknown parameter. This latter takes into account of the dispersion of experimental data and has been evaluated by means of the regression analyses procedure based on the least-squares optimization criteria. The outputs of the proposed constitutive laws were compared with the experimental results currently available in literature. A good matching is observed between the experimental results and the theoretical predictions in terms of axial stress–strain curves.

This article develops an empirically grounded model of antecedents and effects of green information systems (IS) initiatives. The model is empirically based on an in-depth case of the Nordic financial institution. The authors' study examines the effect of several organizational factors, and characteristics of Green IS initiatives themselves on organizations' intention to adopt Green IS initiatives. Their study finds that employees' attitudes toward these initiatives affect their participation in the initiatives, as well as the success of Green IS initiatives. The adoption of the initiatives was seen to affect individual and organizational level outcomes, with positive experiences enabling employees to continue to use/support the initiatives, and organizations also often realizing improvements in practice.

Flow is a well-known concept in the fields of positive and applied psychology. Examination of a large body of flow literature suggests there is a need for a conceptual model rooted in a cognitive approach to explain how this psychological phenomenon works. In this paper, we propose the Flow Engine Framework, a theoretical model explaining dynamic interactions between rearranged flow components and fundamental cognitive processes. Using an IPO framework (Inputs – Processes – Outputs) including a feedback process, we organize flow characteristics into three logically related categories: inputs (requirements for flow), mediating and moderating cognitive processes (attentional and motivational mechanisms) and outputs (subjective and objective outcomes), describing the process of the flow. Comparing flow with an engine, inputs are depicted as flow-fuel, core processes cylinder strokes and outputs as power created to provide motion.

Background: Diabetes is a major and costly health problem for patients and health care system, and requires a change in patient’s lifestyle. The present study aimed to determine the factors predicting fruit and vegetable consumption and HbA1C control in diabetic patients based on the transtheoretical model. Methods: In this cross-sectional study, 98 women with diabetes in Qazvin city were recruited. Information regarding demographic characteristic, transtheoretical model questionnaire, HbA1C level and weekly consumption of fruits and vegetables were completed for each participant. The variables were compared using analysis of variance. Results: The mean HbA1C level was 7.87 and the amount of consumed fruit and vegetables was 2.58 units per day. Of all participants, 77.55% were in the pre-action stage and 22.45% in the action stage of consumption of five portions of fruit and vegetables a day. Diabetic women in action stages of change had significantly higher mean score of self-efficacy (P-value= 0.046) and process of change (P-value= 0.023) compared to women in pre-action stage of change. Conclusion: The results showed that stage of change contributed to the behavior of fruits and vegetables consumption, patients’ self-efficacy and process of change. This study recommends applying transtheoritical model in intervention programs for taking fruits and vegetables in diabetic patients.

The present paper aims to demonstrate the capabilities of the Composite Bolted Joint Element (CBJE) methodology in the framework of single-lap multi-bolt joints analysis. This FE modeling approach exploits the CBJE, a user-defined finite element. It is founded on the complete elastic characterization of the bolted region through analytical models. The elastic behavior of a circular portion of the laminates enclosing the bolt is determined in the context of thick composite plate mechanics; a set of radial beam elements is made structurally equivalent through the custom definition of their stiffness matrix. The interaction between the bolt and the plates is modeled as a beam on elastic foundation. The stiffness contributions of the bolt and the specific properties of the joint, such as preload, bolt-hole clearance, contact stiffness, and friction effects are simulated utilizing an assembly of beam and spring elements. In this way, it is created a FE model from the theoretical solution of the bolted region featuring high fidelity and computational efficiency, as it requires a low amount of degrees of freedom. Experimental data are used to validate the FE model with CBJE of the single-lap three-bolt composite joint. Specimens with varying lay-up, radial clearances, bolts preload and bolt number are also analyzed to evaluate the bolt load distribution and out-of-plane behavior. The CBJE results are successfully compared with those of reference solid models.

This paper aims to accurately identify parameters of the natural charging behavior characteristic (NCBC) for plug-in electric vehicles (PEVs) without measuring any data regarding charging request information of PEVs. To this end, a data-mining method is first proposed to extract the data of natural aggregated charging load (ACL) from the big data of aggregated residential load. Then, a theoretical model of ACL is derived based on the linear convolution theory. The NCBC-parameters are identified by using the mined ACL data and theoretical ACL model via the derived identification model. The proposed methodology is cost-effective and will not expose the privacy of PEVs as it does not need to install sub-metering systems to gather charging request information of each PEV. It is promising in designing unidirectional smart charging schemes which are attractive to power utilities. Case studies verify the feasibility and effectiveness of the proposed methodology.

Lately, concern for green innovation has expanded in the business environment and many companies see it as a helpful element to gain competitive advantage. Due to the strains of maintaining sustainable businesses, mobile commerce companies are propelled to build up their own green innovation programs and harmonize them with the firm’s management programs. The central scope of this research is to examine the drivers for green innovation within a range of Romania-based mobile commerce companies that operate in different industries. With the aim of identifying the factors that determine the development of green innovation, a conceptual model has been conceived. The dependent variable within the model is the action of the company’s management to develop green innovation. Four independent types of variable structures that have an impact on the development of green innovation in mobile commerce firms were distinguished. The four categories of constructs are business environmental factors (1), green training (2), green supplier development (3), and technological factors (4). An online survey tested the model based on the responses of senior level management representatives from 182 Romanian mobile commerce companies from Bucharest. The validity of the model was fulfilled though factor analysis and reliability tests for the data; a logistic regression analysis was also used to test the research hypotheses. The research revealed that green training embodies the fundamental element enhancing green innovation among Romanian mobile commerce companies. This article benefits both academia and business. Firms could be inspired by the results of this paper to broaden the level of green innovation throughout the Romanian business environment.

INTRODUCTION Chronic diseases such as cancer have a strong influence on both physical health and quality of life, which together comprise the concept of health-related quality of life (HRQoL) - in other words, the complete state of physical, social, and psychological functioning. Herein, we review the literature on the theory of HRQoL in relation to oncological diseases. MATERIAL AND METHODS A literature search of English-language publications that included an analysis of the conceptual models of HRQoL was performed using PubMed. The data were screened and synthesized by all authors and relevant papers were selected. RESULTS We outline the theoretical models most often used to conceptualize HRQoL, including the Centre for Health Promotion model from the University of Toronto, the conceptual model of Wilson and Cleary and the contextual model of Ashing-Giwa formulated specifically for cancer patients. CONCLUSIONS Understanding the theoretical basis of HRQoL is indispensable for valid research in this area.

Metronomic dosing of chemotherapy - defined as frequent administration at lower doses - has been shown to be more efficacious than maximum tolerated dose treatment in preclinical studies, and is currently being tested in the clinic. Although multiple mechanisms of benefit from metronomic chemotherapy have been proposed, how these mechanisms are related to one another and which one is dominant for a given tumor-drug combination is not known. To this end, we have developed a mathematical model that incorporates various proposed mechanisms, and report here that improved function of tumor vessels is a key determinant of benefit from metronomic chemotherapy. In our analysis, we used multiple dosage schedules and incorporated interactions among cancer cells, stem-like cancer cells, immune cells, and the tumor vasculature. We found that metronomic chemotherapy induces functional normalization of tumor blood vessels, resulting in improved tumor perfusion. Improved perfusion alleviates hypoxia, which reprograms the immunosuppressive tumor microenvironment toward immunostimulation and improves drug delivery and therapeutic outcomes. Indeed, in our model, improved vessel function enhanced the delivery of oxygen and drugs, increased the number of effector immune cells, and decreased the number of regulatory T cells, which in turn killed a larger number of cancer cells, including cancer stem-like cells. Vessel function was further improved owing to decompression of intratumoral vessels as a result of increased killing of cancer cells, setting up a positive feedback loop. Our model enables evaluation of the relative importance of these mechanisms, and suggests guidelines for the optimal use of metronomic therapy. © 2017, National Academy of Sciences. All rights reserved. 114 1994 1999 1994-1999

It is well known that regular physical activity helps improve overall health and fitness and reduces the risk of many chronic diseases. However, excessive exercise might be harmful. Exercise addiction (EA) is a pattern of uncontrolled exercise that involves a craving for overwhelming exercise with addictive attributes. So far, little is known about this unique behavioral addiction. The aim of the current study is to introduce the diagnosis and assessment of EA, and to summarize several developing theoretical models. Eating disorders, body image disorder, low self-esteem, and high narcissism are related to high risk of EA. The paper also discusses the distinction between EA and highly involved physical activity. Keywords: Exercise addiction, Behavior addiction, Physical activity, Theoretical model

The current literature presents a discordant view of mild traumatic brain injury and its effects on the human brain. This dissonance has often been attributed to heterogeneities in study populations, aetiology, acuteness, experimental paradigms and/or testing modalities. To investigate the progression of mild traumatic brain injury in the human brain, the present study employed data from 93 subjects (48 healthy controls) representing both acute and chronic stages of mild traumatic brain injury. The effects of concussion across different stages of injury were measured using two metrics of functional connectivity in segments of electroencephalography time-locked to an active oddball task. Coherence and weighted phase-lag index were calculated separately for individual frequency bands (delta, theta, alpha and beta) to measure the functional connectivity between six electrode clusters distributed from frontal to parietal regions across both hemispheres. Results show an increase in functional connectivity in the acute stage after mild traumatic brain injury, contrasted with significantly reduced functional connectivity in chronic stages of injury. This finding indicates a non-linear time-dependent effect of injury. To understand this pattern of changing functional connectivity in relation to prior evidence, we propose a new model of the time-course of the effects of mild traumatic brain injury on the brain that brings together research from multiple neuroimaging modalities and unifies the various lines of evidence that at first appear to be in conflict., We investigate concussion’s effects on the human brain directly after impact and decades post-injury. Functional connectivity between a set of brain areas was heightened in recently concussed subjects and was diminished in subjects who sustained their injuries years prior (compared to age-matched controls). The study highlights the dynamic nature of concussion., Graphical Abstract Graphical Abstract

During the flood discharge in large-scale hydraulic engineering projects, intense flow-induced vibrations may occur in hydraulic gates, gate piers, spillway guide walls, etc. Furthermore, the vibration mechanism is complicated. For the spillway guide wall, existing studies on the vibration mechanism usually focus on the vibrations caused by flow excitations, without considering the influence of dam vibration. According to prototype tests, the vibrations of the spillway guide wall and the dam show synchronization. Thus, this paper presents a new vibration mechanism of associated-forced coupled vibration (AFCV) for the spillway guide wall to investigate the dynamic responses and reveal coupled vibrational properties and vibrational correlations. Different from conventional flow-induced vibration theory, this paper considers the spillway guide wall as a lightweight accessory structure connected to a large-scale primary structure. A corresponding simplified theoretical model for the AFCV system is established, with theoretical derivations given. Then, several vibrational signals measured in different structures in prototype tests are handled by the cross-wavelet transform (XWS) to reveal the vibrational correlation between the spillway guide wall and the dam. Afterwards, mutual analyses of numeral simulation, theoretical derivation, and prototype data are employed to clarify the vibration mechanism of a spillway guide wall. The proposed mechanism can give more reasonable and accurate results regarding the dynamic response and amplitude coefficient of the guide wall. Moreover, by changing the parameters in the theoretical model through practical measures, the proposed vibration mechanism can provide benefits to vibration control and structural design.

The purpose of this paper is to explore the process of Cloud Computing adoption within Romanian Small and Medium sized Enterprises in the digital age. Most of the scientific papers related to this topic examine the general outlook of cloud computing implementation in Romania and focus on the use of the afore-mentioned technologies by large scale companies. In order to identify the factors that have an influence over the choice of Romanian SMEs to adopt cloud computing technology, a conceptual model has been set forth. The model’s dependent variable is the choice of the company’s management to implement cloud computing technologies. Five different independent types of variable structures which have an effect on the adoption of cloud computing within SMEs were identified. The five categories of variables are competition & government, ICT providers & firm departments, employee, manager and technological factors. Each of these categories of determinants encompasses at their turn two or more constructs. An online survey tested the model based on the responses of managers and directors from 198 Romanian SMEs from the cities of Bucharest and Cluj. The validity of the model was performed by completing factor analysis and reliability tests of the data; a logistic regression analysis was deployed to test the research hypotheses. The results emphasized that the managers’ know-how on cloud computing and the perceived costs of implementing the technology represent the main components influencing the spreading of cloud computing among Romanian SMEs. This study makes a valuable contribution to the academic environment but to businesses as well. The model can be used to examine the implementation of different innovative applications. Companies which offer cloud computing services could take advantage of the outcomes of this study to expand the degree of cloud service introduction among SMEs.

The no-pillar mining method is widely used in coal mining engineering because of its superiority in resolving mine pressure hazards and protecting natural resources. In view of the geological conditions of stable strata in a coal mine of the Shandong Coal Zone, a novel segmented roadside plugging-filling mining method is proposed by introducing the filling coefficient into roadside filling. The operation process is designed with a new grouting filling forming device. Based on the relationship between the theoretical deflection of a cantilever beam and geometric settlement and parallel settlement models, strength formulas applicable to the segmented roadside plugging-filling (SRPF) method at different migration stages are obtained, and the deformation formulas of a roadway toward a rock slab are solved by an elastic equivalent model. Further, the determination procedure of the filling mode under the mining method is clarified. The SRPF method was implemented on a test stope, and the test results indicated that the theoretical deformation produced by the SRPF method was small and can meet the mining requirements. Through on-site test monitoring, the deformation of surrounding rock was 0–160 mm and the filling body under the SRPF method could maintain its own strength and the stability of the surrounding rock. In addition, entire successful mining been completed in the working stope, which further proves the applicability of this method. The backfilling cost of the gob-side filling was reduced by approximately 50%, and the backfilling efficiency was improved in the mine. The description of the novel mining method may provide theoretical and practical guidance for coal mining in similar geological conditions.

Flexible pipelines must be designed considering the extreme situation for which additional components are needed against severe loading and environmental conditions. Tensile armor is employed in case of high tensile forces , which increase with water depth; and massive components used against high internal and external pressures. In this paper, the mechanical behavior of the pipe under pure tension is investigated by both theoretical and numerical analysis, then the contribution of the external pressure to the axial problem is examined using an analytical analysis. As the deformations along the longitudinal direction of the studied pipe highly depend on the radial stiffness of the cross section, the influence of the pressure armor is carefully evaluated in the inception phase, and its radial stiffness is verified by its own numerical results. The plastic behavior for both steel and polymer layers is taken into account by using the secant modulus method. Moreover, this work answers a question raised by producers that need to know when tensile armor is required to reinforce Metallic Strip Flexible Pipes (MSFP). The theoretical model is employed to carry out the comparison between pipes with different configurations, in order to investigate the influencing parameters of the tensile stiffness . The results obtained from the theoretical and the numerical simulations lead to a remarkable confidence in the analytical solution thanks to a relatively small difference between the outcomes.

The use of sheep wool as a filler of cement in order to produce mortar or plaster involves several advantages for environment and energy. Moreover, it is considered as a waste and, therefore, its use is characterized by low cost. The aim of this paper is to evaluate the influence of wool fibers on thermal conductivity and mechanical properties of cement. The samples were prepared using wool fibers, obtained from a breed of Sicilian sheep, with three different lengths (i.e., 1, 6, and 20 mm). Furthermore, in order to evaluate the influence of fiber content, the samples were prepared by varying the fiber weight fraction. The thermal conductivity of the samples was analyzed by using a heat flow meter, whereas the mechanical behavior was studied through compressive tests. In order to validate the thermal measurements, on the experimental data, two theoretical models were applied. The experimental results showed that wool fibers can be used within cementitious matrices to obtain mortars or plasters with enhanced thermal insulation properties. Nevertheless, noticeable decrements in the compressive strength are also found. Therefore, it is needed to find a compromise between these two aspects

The Colombian swine supply chain (CSSC) has a low level of national competitiveness compared to other supply chains such as coffee and fruit. While consumption of pork has raised in Colombia, most dealers are importing it from The United States and Canada, since farmers in those countries have received agricultural incentives to breed and commercialize pigs. Additionally, agribusiness have received technological developments to share information and develop the swine sector. This article aims to state theoretical Knowledge Management (KM) dimensions for CSSC that were built under authors’ assumptions on the literature. These were proposed to identify the competitiveness level in CSSC, because only two different kinds of measuring for swine competitiveness were found, but on the other hand, no model about Swine Supply Chain (SSC) was found. Perspectives of researching KM in CSSC would integrate stakeholders using a technological web platform which allows interchange of information among them., La cadena de suministro porcina colombiana (CSSC) tiene un bajo nivel de competitividad nacional en comparación con otras cadenas de suministro como café y frutas. Si bien el consumo de carne de cerdo ha aumentado en Colombia, la mayoría de los comerciantes la importan de Estados Unidos y Canadá, ya que los ganaderos de esos países han recibido incentivos agrícolas para criar y comercializar cerdos. Adicionalmente, la agroindustria ha recibido desarrollos tecnológicos para compartir información y desarrollar el sector porcino. Este artículo tiene como objetivo establecer las dimensiones teóricas de la Gestión del conocimiento (KM) para CSSC que se construyeron bajo los supuestos de los autores en la literatura. Estos fueron propuestos para identificar el nivel de competitividad en CSSC, debido a que solo se encontraron dos tipos diferentes de medición para la competitividad porcina, pero por otro lado, no se encontró un modelo sobre Cadena de suministro porcina (SSC). Las perspectivas de investigar KM en CSSC integrarían a las partes interesadas utilizando una plataforma web tecnológica que permita el intercambio de información entre ellos.

In-plane seismic behaviour of Cross-Laminated Timber (CLT) walls is influenced by panel-to-panel and panel-to-foundation mechanical connections, which consist of hold-downs and angle brackets. Due to the platform constructional technology, the orthogonal to grain timber-to-timber contact is also involved in the seismic response of the panels. To date, literature theoretical approaches to evaluating the flexural load-bearing capacity of CLT panels focus their attention on the schematization of hold-downs and angle brackets only, under evaluating the role of timber compressed in the perpendicular direction. In this paper the influence of orthogonal to grain timber properties on the overall seismic behaviour of CLT walls has been investigated, proposing a general theoretical model to schematize the panel-to-panel and panel-to-foundation connections. A parabola-rectangle constitutive behaviour has been defined to describe the orthogonal to grain timber behaviour in the connection zones, while hold-downs and angle brackets are modelled adopting literature models. Five different failure conditions, described by mathematical formulations, able to describe the entire axial force-bending moment interaction domain have been defined. The proposed model has also been employed to schematize the connection zones in multi-storey CLT walls with openings, allowing to investigate the effect of the orthogonal to grain properties on its seismic behaviour. Results of nonlinear analyses demonstrate a significant influence of orthogonal to grain timber properties on seismic behaviour of the walls, affecting their strength, stiffness, ductility and collapse mechanisms.

Objective to identify possible mechanisms by which caseload midwifery reduces preterm birth for young childbearing women. Design a mixed methods triangulation, convergence design was used to answer the research question ‘How does the way maternity care is provided affect the health and well-being of young women and their babies?’ The project generated quantitative and qualitative findings which were collected and analysed concurrently then separately analysed and published. The research design enabled integration of the quantitative and qualitative findings for further interpretation through a critical pragmatic lens. Setting a tertiary maternity hospital in Australia providing care to approximately 500 pregnant young women (aged 21 years or less) each year. Three distinct models of care were offered: caseload midwifery, young women's clinic, and standard 'fragmented' care. Participants a cohort study included data from 1971 young women and babies during 2008–2012. An ethnographic study included analysis of focus group interviews with four caseload midwives in the young women's midwifery group practice; as well as ten pregnant and postnatal young women receiving caseload midwifery care. Findings integrated analysis of the quantitative and qualitative findings suggested particular features in the model of care which facilitated young women turning up for antenatal care (at an earlier gestation and more frequently) and buying in to the process (disclosing risks, engaging in self-care activities and accepting referrals for assistance). We conceptualised that Optimal Caseload Midwifery promotes Synergistic Health Engagement between midwife and the young woman. Key conclusions optimal Caseload Midwifery (which includes midwives with specific personal attributes and philosophical commitments, along with appropriate institutional infrastructure and support) facilitates midwives and young clients to develop trusting relationships and engage in maternity care. Health engagement can modify predictors for preterm birth that are common amongst pregnant adolescents by promoting earlier maternity booking, sufficient antenatal care, greater emotional resilience, ideal gestational weight gain, less smoking/drug use, and fewer untreated genito-urinary infections. Implications for practice the institutional infrastructure and managerial support for caseload midwifery should value and prioritise the philosophical commitments and personal attributes required to optimise the model. Furthermore the location of visits, between appointment access to primary midwife, and back-up system should be organised to optimise the midwife-woman relationship in order to promote the young woman's engagement with maternity care.

In this paper, a new analytical model is proposed to describe the behavior of uncertainty for a generic vision-based measurement system applied to mechanical vibration measurement. In particular, this paper proposes a novel way to evaluate the effects of motion blur. The theoretical framework presented here takes into account the camera acquisition parameters, the dynamics of the measurand (in terms of instantaneous speed), and the image scaling factor to develop a physical model of uncertainty when measuring a mainly monomodal vibration. Uncertainty is evaluated starting from the normalized discrepancy between a measured position and the actual one. The analytical model proposed here has been validated extensively with the help of a test stand that can generate biaxial monomodal vibrations. The motion of a target mounted on the test stand has been simultaneously monitored by a stereo vision rig and a set of triangulation lasers. Model validation has been carried out using two measurement techniques: stereo vision blob analysis and digital image correlation. The experimental results show that the proposed model is able to represent the behavior of uncertainty for both the techniques. After the model has been validated, it is shown how it is possible to exploit it to estimate the uncertainty of a vision rig starting from the nominal characteristics of both the vision system and the target. This can be a tool to facilitate the design of vision-based measurement systems.

Chamber testing is a common method to evaluate volatile organic compound (VOC) emissions from building materials. Empirical models based on short-term testing (typically less than 28 days) are frequently used to estimate long-term emissions (up to years). However, the applicability of the empirical models for long-term prediction remains unclear in practice. Four empirical models, i.e., two constant models with and without a prerequisite (M1 and M2), a power-law model (M3), and an exponential model (M4), were used to test the applicability of predicting year-long emissions using emission data that were less than one month. The diffusion-based mass-transfer model was used to generate reference emission data with random variations involved to represent measurement errors, etc. For M1 and M2, the discrepancy ratios between the constant emissions and the characteristic average emissions are quantified. For M3 and M4, an additional measure, i.e., normalized mean square error (NMSE), was adopted to statistically study the applicability of using empirical models to predict long-term emissions. The results shown that, first, the NMSE values indicate that M3 prefers slow emissions and generally performs better than M4. However, M4 performs better for predicting year-long emissions for cases with characteristic emission time of one year. Second, both M3 and M4 predict the average life-long emissions reasonably well for most scenarios. Third, while the effects of test duration are less significant for M3 than M4, the early-stage sampling points are more important for better long-term predictions. Additionally, experimental data by National Research Council Canada (NRC) were used to validate the applicability of the empirical models in year-long emission predictions, with the results similar to those from the simulated data. This paper can be used as a reference to select appropriate empirical model(s), as well as the testing duration, to simulate long-term VOC emissions from building materials using short-term testing data.