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In this paper I explore how members of rural Maya households in central Quintana Roo (Mexico) interact with the wider social system and cope with long-term transformations in productive relations since c. 1840. Maya householders integrate elements of capitalist and non-capitalist modes of production. Through particular cultural forms they regulate internal uses of wealth and their relationships with the larger capitalist world. Social and economic stratification is a fundamental feature of life among Maya householders today as it was in the past. While disparities between wealth strata within the local context have increased, the community is far from disintegrating into antagonistic groups.

Miniaturization with high thermal performance and lower cost is one of the advanced developments in industrial science chemical and engineering fields including microheat exchangers, micro mixers, micropumps, cooling microelectro mechanical devices, etc. In addition to this, the minimization of the entropy is the utilization of the energy of thermal devices. Based on this, in the present investigation, micropolar nanofluid flow through an inclined channel under the impacts of viscous dissipation and mixed convection with velocity slip and temperature jump has been numerically studied. Also the influence of magnetism and radiative heat flux is used.

The nonlinear system of ordinary differential equations are obtained by applying suitable dimensionless variables to the governing equations, and then the Runge–Kutta–Felhberg integration scheme is used to find the solution of velocity and temperature. Entropy generation and Bejan number are calculated via using these solutions.

It is established to notice that the entropy generation can be improved with the aspects of viscous dissipation, magnetism and radiative heat flux. The roles of angle of inclination (α), Eckert number (Ec), Reynolds number (Re), thermal radiation (Rd), material parameter (K),  slip parameter (δ), microinertial parameter (aj), magnetic parameter (M), Grashof number (Gr) and pressure gradient parameter (A) are demonstrated. It is found that the angle of inclination and Grashof number enhances the entropy production while it is diminished with material parameter and magnetic parameter.

Electrically conducting micropolar nanofluid flow through an inclined channel subjected to the friction irreversibility with temperature jump and velocity slip under the influence of radiative heat flux has been numerically investigated.

Microfluidics is one of the interesting areas of the research in thermal and engineering fields due to its wide range of applications in a variety of heat transport problems such as micromixers, micropumps, cooling systems for microelectromechanical systems (MEMS) micro heat exchangers, etc. Lower cost with better thermal performance is the main objective of these devices. Therefore, in this study, the entropy generation in an electrically conducting Casson fluid flow through an inclined microchannel with hydraulic slip and the convective condition hves been numerically investigated. Aspects of viscous dissipation, natural convection, joule heating, magnetic field and uniform heat source/sink are used

Suitable non-dimensional variables are used to reduce the non-linear system of ordinary differential equations, and then this system is solved numerically using Runge-Kutta-Fehlberg fourth fifth order method along with shooting technique. The obtained numerical solutions of the fluid velocity and temperature are used to characterize the entropy generation and Bejan number. Also, the Nusselt number and skin friction coefficient for various values of parameters are examined in detail through graphs. The obtained present results are compared with the existing one which is perfectly found to be in good agreement.

It is established that the production of the entropy can be improved with the aspects of joule heating, viscous dissipation and internal heat source/sink. The entropy generation enhances for increasing values of Casson Parameter (β) and Biot number (Bi). Furthermore, it is interestingly noticed that the enhancement of Reynolds number and uniform heat source/sink shows the dual behaviour of the entropy generation due to significant influence of the viscous forces in the region close to the channel walls. It was observed that increasing behaviour of the heat transfer rate for enhancement values of the Eckert number and heat source/sink ratio parameter and the drag force are retarded with higher estimations of Reynolds number.

Entropy generation analysis on MHD Casson fluid flow through an inclined microchannel with the aspects of convective, Joule heating, viscous dissipation, magnetism, hydraulic slip and internal heat source/sink has been numerically investigated.

Microfluidics is one of the extensive elaborated technologies in thermal and engineering fields due to its wide range of applications, such as micro heat exchangers, micro mixture and microchannel heat sinks, which is used to develop a large number of microscopic devices and systems. Enhancement of thermal energy using verity of nanoliquids is one of the challenges in these applications of microfluidics. Therefore, using single wall carbon nanotubes for enhancement of thermal energy in microchannel is the main purpose of this study. Hall effect of natural convection flow in a vertical channel with slip and temperature jump condition is considered. The impacts of radiative heat flux, uniform heat source/sink, viscous dissipation and joule heating are also taken into account.

Suitable non-dimension variables are applied to the governing equations to reduce the system into ordinary differential equations. The reduced nonlinear system is then solved numerically using Runge–Kutta–Fehlberg fourth–fifth-order method along with shooting technique. The impact of different pertinent parameters on numerical solutions of primary velocity, secondary velocity, temperature, entropy generation and Bejan number is comprehensively discussed in detail. Also, the obtained numerical results are compared with existing one which perfectly found to be in good agreement.

It is established that, with the aspects of Joule heating, viscous dissipation, radiative heat flux and uniform heat source/sink, the production in the entropy can be improved. Further, it is found that the increasing ratio of wall ambient temperature difference and nanoparticle volume fraction leads to enhance the entropy generation. The same effect reverses with increasing values of fluid wall interaction parameter (FWIP) and rare faction. The irreversibility ratio enhances with larger values of nanoparticle volume fraction and decelerates with increment values of FWIP.

The impact of single wall carbon nanoliquid in a vertical channel flow by using radiative heat flux, heat source/sink, joule heating and viscous dissipation is first time investigated. Further, the influence of Hall current is explored in detail.

Call centers generate stress and absenteeism in staff and the literature suggests that people-oriented leadership is the right way of supervision for such a situation. This study compared its effects versus those of other types of leadership.

Absentee data of 379 representatives of customer services of a Peruvian call center were analyzed and the representatives answered a questionnaire about the Framework of Values in Competition and its four types of leadership. Day and night work shifts were compared.

It was observed that absenteeism declines with people-oriented leadership, although only during the day shift, and the addition of leadership oriented to change, results and control devalues models.

Future studies should cover the performance of the worker. The findings suggest a need to re-focus the theoretical focus on environmental contingencies that affect leadership effectiveness.

Leadership theorists will ask themselves in what circumstances the multiple leadership is effective. Call center managers will appreciate the organizational value of people-oriented leadership at the first level of supervision.

Parameter identification is a technique which aims at determining material or other process parameters based on a combination of experimental and numerical techniques. In recent years, heuristic approaches, such as genetic algorithms (GAs), have been proposed as possible alternatives to classical identification procedures. The present work shows that particle swarm optimization (PSO), as an example of such methods, is also appropriate to identification of inelastic parameters. The paper aims to discuss these issues.

PSO is a class of swarm intelligence algorithms which attempts to reproduce the social behaviour of a generic population. In parameter identification, each individual particle is associated to hyper-coordinates in the search space, corresponding to a set of material parameters, upon which velocity operators with random components are applied, leading the particles to cluster together at convergence.

PSO has proved to be a viable alternative to identification of inelastic parameters owing to its robustness (achieving the global minimum with high tolerance for variations of the population size and control parameters), and, contrasting to GAs, higher convergence rate and small number of control variables.

PSO has been mostly applied to electrical and industrial engineering. This paper extends the field of application of the method to identification of inelastic material parameters.

The purpose of this paper is to conduct a quantitative analysis of the university accreditation processes in Chilean universities. The aim is to determine the effects of the different variables, especially the type of institutions (state- and privately owned, with and without state financial support) on the results obtained.

Univariate and multivariate statistical analysis of official data.

Results indicate consistency in the accreditation processes in Chilean universities, as those variables directly associated with the processes accounted for approximately 70 per cent of the variation in the length of accreditation periods (between 0 and seven years), these variables being the ones that defined the type of universities. High dispersion was found in six state-owned universities that behaved as if they were private universities and in two private universities that behaved as if they were state universities. However, a high percentage of the universities included in the analysis maintained their affiliation to their corresponding legal group, when their performance in accreditation processes was analyzed.

The results of the university accreditation processes in Chile have been the focus of a intense debate due to the legal and economic conflicts between the different types of universities. This study constitutes the first scientific analysis of the results of these processes, especially in terms of the performance of the different types of universities, thus enabling a better interpretation of the results. This information is useful not only in the terms of the legal reforms that are being carried out in Chile, but they also help the understanding of the processes of accreditation of higher education in other Latin American countries.

In a village of Eastern Yucatan, Mexico, cargo or kuuch sponsors compare their ritual tasks to “buying life” from crosses, Catholic saints, and Mayan deities or “owners.” The local notion of compromiso, engagement, or commitment, helps these festival participants express the condition of possibility to successfully perform such exchanges. Decisive for these life renewals, promises, and compromisos depend upon empathy to authorize ritualists and subsume social and natural phenomena under exchange paradigms. By defining, critiquing and using the concept of “disposition” as an inherently self-other stance through which economy transforms into religiosity and vice versa, this chapter analyzes this particular regime of engagement and the temporalities it implies. Through a commitment to the past and the practice of promissory exchange, sponsors develop a new perceptual scheme in which the ritual cultivation of discipline, awareness, expectation, and responsibility are expressed.

This chapter presents an overview of social entrepreneurship and social innovation in Colombia and explores its implications in the Pacific Alliance. It is organized into five sections that provide an overview of the fields of social entrepreneurship and social innovation with the aim of sharing experiences that have occurred in the country with the international academic community. It offers a description of the social and economic context of Colombia and then presents the situations that currently serve as the basis of social entrepreneurship and social innovation. It also discusses the main actors that are active in this context. In particular, the chapter emphasizes the experience of the city of Medellín, which is thought to provide an auspicious scenario for the establishment of a business ecosystem based on social entrepreneurship and social innovation. The learnings of Colombia can serve as a relevant example for the countries of the Pacific Alliance that are currently building their social business ecosystems.