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The overall equipment effectiveness (OEE) is an indicator used in the management and continuous improvement of production systems, and is useful in identifying losses, thus reducing production costs. By analyzing the results of this indicator, the operation manager must make decisions to eliminate or reduce losses in the process. This study investigated the application of the OEE indicator in one production line in the pulp and paper industry. The implementation of OEE was performed in stages with a detailed analysis of the indicators that compose the OEE (quality, performance, and availability) to identify possible improvements. Thus, actions were implemented to improve the OEE quality index. This study provided important information that enabled the operation manager to diagnose and minimize the occurrence of failures and losses, which is often hidden and unknown to those involved in the production system.

Introduction: The National Scientific Congress (NSC) is an annual event held in Peru in which medical students from all over the country present their research work. Objectives: To determine the publication rate in indexed scientific journals of research papers submitted to the NSCs held between 2010 and 2014, as well as the factors associated with their publication, and to describe the characteristics of the published papers. Materials and methods: Retrospective study in which 407 abstracts of research papers were reviewed. A publication time window of 6 years (from submission) was considered. A bivariate analysis was performed to assess differences between categorical and numerical variables using the chi-square and Mann-Whitney U tests, respectively. In addition, a multivariate analysis was performed using Poisson regression models (a crude and an adjusted model), calculating relative risk (RR) values with their respective 95% confidence intervals (95%CI) to determine the factors associated with the publication of papers. A significance level of p

En este artículo se estudia la fabricación y el comportamiento mecánico de paneles a base de papel reciclado. El objetivo principal del proyecto es producir un prototipo de panel que emplee elementos provenientes de residuos sólidos (papel periódico) y de un material conglomerante (cemento Portland blanco). El panel debe ser económico, debe tener buenas propiedades mecánicas y debe tener dimensiones comerciales para su uso en muros tabiques y en cielos falsos en la industria de la construcción. El Recipanel es un panel no estructural a base de papel reciclado. El Recipanel cumple las normas colombianas en lo relativo a los paneles de uso no estructural y presenta además unas excelentes características mecánicas.

El lodo de papel reciclado es una materia prima promisoria para la producción de etanol. En esta investigación, nosotros primero evaluamos el efecto de la concentración de etanol, la carga de sólidos y la cristalinidad de la celulosa sobre la hidrólisis enzimática de la celulosa. También se evaluó la producción de etanol con lodo de papel mediante el proceso de sacarificación y fermentación simultanea (SSF) e hidrólisis y fermentación separada (SHF) empleando la levadura Kluyveromyces marxianus ATCC 36907. El etanol presenta un efecto inhibitorio sobre la hidrólisis de la celulosa. Una concentración de etanol de 40 g/L genera una reducción del 79 % en la producción teórica de azúcares reductores. Al incrementar la concentración de sólidos se observa una reducción en la conversión de la celulosa a azúcares reductores obteniéndose un 76 % de conversión con 9 % de sólidos. Una mayor conversión y productividad en etanol fueron alcanzadas en el proceso SSF en relación al proceso SHF en 72 horas de tratamiento.

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As Bagus and Howden (2010) highlighted, one of the paths to achieve a more fruitful understanding of the business cycle involves examining saving as a heterogeneous analytical category. The aim of this paper is to continue this line of inquiry using the capital-based framework developed by Garrison (2001). This paper contributes to the literature by studying the impact of heterogenous savings on economic growth and business cycles in a capital-based macroeconomics framework. With this aim the implications of disaggregated saving is analysed by means of the differential market signals that are generated by cash-build savings (Pătruți, 2017) and loanable funds accessible through the credit markets.

This paper presents a general model for the design to obtain the thickness and reinforcing steel areas of rectangular footings that support from 1 to “n” columns aligned on a longitudinal axis. The pressure diagram is considered linear. Some recently published papers are restricted to certain types of footings as the rectangular isolated footings, and rectangular combined footings that support two columns. The first part of this paper shows the minimum soil area that supports 1 to “n” columns aligned on a longitudinal axis. Three numerical examples are presented for design of rectangular footings subjected to an axial load and two orthogonal moments in each column that supports one, two and three columns. The main advantage of this document over other documents is: this model can be applied for one or more columns supported on a rectangular footing (unrestricted on its sides, one side restricted and two opposite sides restricted).

This paper researches the influence of zinc coating of galvanized DP600 steel (DP600G) on the nugget development and mechanical properties of dissimilar DP600 - AISI304 welded joints obtained by resistance spot welding process (RSW). The RSW evaluations consisted of determining, from the dynamic resistance curves, the different stages involved in nugget formation. The experimental results showed that the zinc coating on the DP600G steel has a significant influence on the time needed for the start of the nugget formation, two times higher than that used for non-galvanized steel. The expulsion time was delayed by 1.12 times. The presence of Zn in the DP600G/AISI304 welded joints produced smaller nugget diameters compared to the DP600/AISI304 joints for the same experimental conditions, however higher peak failure load values were obtained for the first. The causes of this unusual behavior are also analyzed in this paper.

This paper investigates factors that motivate entrepreneurs to completely operate within informality and the drivers of formal companies to underreport revenues. In particular, this work identifies and organizes the determinants of firm informality through a systematic literature review in Scopus and Web of Science databases. The article presents several contributions. First, it examines the two main frameworks of informality (structuralist/exclusion and legalistic/exit dimensions) and links this with the different roles of unregistered firms in economic development (survival, De Soto, and parasite views). It also studies the theoretical basis of informality, including economic, institutional, psychological, and sociological aspects. Second, the paper summarizes business informality determinants based on studies with different methodological approaches (macro, microeconomic), contexts (developed, emerging, transition economies), and periods (1983-2018). Our results show that firm informality is mostly addressed in the examined literature as a decision or voluntary choice by companies and entrepreneurs (legalistic vision). Third, the article proposes an integral theoretical model, according to which the firm informality level is determined by structural elements (company and entrepreneur’s characteristics) and environmental factors (corruption, bureaucracy, taxes, etc.). The analysis is relevant for researchers studying this subject and for policymakers as well.

Emerging serious games mark the beginning of a new era in video games. Emerging serious games introduce advances in distributed artificial intelligence into their design in order to guide the player’s manipulation of a specific subject in an adaptive way. In this article, we present a city simulator game, called Metropolis, which generates emergent properties. Metropolis can be used by a smart city for city planning, to make collective decisions, and for other purposes. This paper describes why Metropolis can be classified as a serious game. It also analyzes how its emergent properties can be used for managing a smart city, and especially how it promotes e-participation as an e-decision-making tool within the context of urban planning. In addition, this paper explores how Metropolis can be used to analyze a smart city’s emergent citizen and urban patterns (urban spatial distribution) based on strong e-participation.

We analyse gender gaps in published works on economics in Uruguay. First of all, we describe the evolution of the professional context and female participation in the discipline. We then provide an empirical analysis of the research output based on two databases: one containing working papers and technical documents and the other including articles published in journals. The main results are: a) men produce more published articles than women but there is no gender gap in working papers; b) women and men are unevenly represented throughout different fields; c) collaboration with non-local authors is more likely among men than women; d) non-local co-authorship is strongly associated with the gender gap in journal articles production.

This paper presents the phonological vowel systems of 16 Chibchan languages, according to existing descriptions. Its purpose is to provide a basic and systematic overview of the vowel systems found in this family. For each language, the distinctive features needed to distinguish the vowel phonemes are discussed, as well as their phonetic realizations when this is relevant. Whereas the phoneme classification is uncontroversial for many of the languages, there are also some Chibchan languages that have been subject to very different analyses over the years; in these cases, a more thorough discussion is provided. At the end of the paper, the Chibchan vowel systems are compared from a quantitative perspective.

Kamsá is a language isolate spoken in the Sibundoy Valley in the Putumayo department of southern Colombia. Its speech community lives on the eastern slopes of the Andes Mountains, between the linguistic areas of the Andes and the Amazon. This paper presents various grammatical features of Kamsá, including its phonology, nominal morphology (especially noun class and case marking), verbal morphology (especially person/number marking for core arguments and evidentiality), morphosyntactic alignment, and syntax (including discussion of causatives, comparatives, and subordinate clauses). In doing so, the paper places Kamsá within its typological and geographical context, between the Amazon and the Andes.

This paper examines African epistemologies of the environment as a place-based perspective that regards nature as having its inherent value, personhood, and agency. It presents the African way of relating with or living in the environment as a way of becoming one with nature beyond the discourse of the Anthropocene and environmental change. In particular, we will take African epistemological perspectives from Southern and Eastern Africa, the notions of Ubuntu and Tabot, to reflect on how the environment is traditionally perceived as sacred and part of a living community. The paper also considers how African indigenous ways of knowing and becoming one with nature have been supplanted through epistemic violence, the imposition of western views of the environment over African worldviews through systems and institutions that exclude or exploit local knowledges. Using Ethiopia as a case study, the paper demonstrates how epistemic violence is enacted by excluding indigenous knowledges of the environment from education and disseminating Eurocentric views of the environment. It shall show how the collecting and hording of Ethiopian manuscripts in western institutions has contributed to this loss of indigenous environmental knowledge. Finally, we will examine the importance of African perspectives to decolonise our ways of knowing and relating with the environment, and offer critical insights on how African epistemologies could be used to build a future that is decolonised and sustainable.

Workforce agility has been described as a management strategy that allows companies to respond quickly and effectively to threats and opportunities arising from a competitive and unstable business environment. In the current literature, there is still a lack of efforts to systematically review the state of the art on this subject. The aim of this paper is to address this gap by studying the academic progress on workforce agility. A systematic literature review was carried out to analyze the academic articles within the workforce agility topic that were published online until the end of June 2020 in three electronic databases: Web of Science (WoS), Scopus, and Science Direct. The bibliometric indicators present how the field has developed and which actors (authors, institutions, countries, journals) are the most relevant. Regarding the conceptual aspects, the findings allowed us to identify that an agile workforce consists of four interrelated and interdependent dimensions: proactivity, flexibility and adaptability, resilience, and competence. These attributes can be promoted through strategies related to i) learning and training, ii) forms of work organization, iii) human resource management; and iv) culture and organizational structure. Our findings also allowed us to propose an agenda for future studies on workforce agility and other related topics. This paper contributes by promoting a debate on a subject still incipient in the literature, especially in Latin America, and by highlighting the potential competitive advantage associated with workforce agility for companies.

This paper evaluates the real capacity of the customer service system in a Health Care Service Provider (HCSP) in which users request a service using a multi-channel M/M/n queueing system with Poisson arrivals and exponential times. The assistance process shows that an individual who wants to request a diagnostic test must wait his/her turn in several cubicles. The aim of this paper is to develop a methodology that generates two-way results in improving not only HCSP performance, but also in implementing strategies that lead to better service perception. A discrete-event simulation model is presented to determine the times for processes and forecast the demand. The entire process in HCSP takes up to four hours, although, based on our results, waiting times could be 50% shorter by decreasing the number of operative tasks that physicians and nurses should perform and implementing an electronic ticket dispenser. Improving customer service is relevant for a HCSP organization. Therefore, our simulation process could be implemented in different scenarios in order to integrate results in planning and decision-making processes.

This paper presents a method to calculate multiple voltage stability limits (VSLs), voltage stability margins (VSMs), and voltage stability curves (VSCs). A multiobjective metaheuristic algorithm was used to change real and reactive powers of loads and generators and perform contingencies of the network elements. The maximum values of real and reactive powers were selected using fast non-dominated sorting and crowding distance techniques, combined with a conventional power flow (PF), and referred to in this paper as NSPF. The results show that the method can select and assess multiple maximum real and reactive powers allowed for a bus, an area, or the power system and that it can consider changes in load, generation, and contingencies. Results were validated using the PF and continuation power flow methods. The method finds a large number of VSCs in less time than the conventional methods and estimates multiple VSLs and VSMs.

In warehouse operations management, picking is one of the most expensive and time-consuming activities; its impact can be seen in the final product delivered to clients, affecting logistic Key Performance Indicators and level of service. On the other hand, changes in picking policy and quality control are challenging to implement in a real-world context. In this paper, we used a simulation methodology to determine the best flow of products and the optimum ratio of the sample in control quality. Simulation has been shown as an useful tool for industrial engineering to determine the best flow and bottlenecks inside the warehouse. This paper found significant improvements when the proposed changes in the picking policy and quality control methods were simulated. Our research also showed that the sampling quality control brings substantial gains to the queuing time, while nonetheless maintaining the desirable quality.

The past twenty years have seen increased importance attached to high growth firms (HGFs). Despite decades of research, our knowledge of HGFs remains limited. Scholars have asserted that a key differentiator of HGFs is their ability to create value for their customers, yet this relationship has gone untested. This paper makes an important contribution to the literature by empirically exploring this relationship. Drawing on comparative cohorts of HGFs and non-HGFs, this paper finds that HGFs were found to be much more likely than their non-HGF counterparts to be positively influencing customer perceived value, the creation of which is considered to be an important enabler of firm performance and growth. In addition to its empirical contribution to the high growth entrepreneurship literature, this paper raises issues for future research.

The loosely coupled systems (LCS) perspective emerged as a new way to understand the organizational structure from the field of Organization Studies. The purpose of this article is to pres­ent the main features of previous research studies that have addressed the perspective of loosely coupled systems. This article is based on a systematic literature review of 76 papers published dur­ing a 36-year period (1983-2019). The findings indicate that the main concepts studied around this perspective have been loose coupling, tight coupling, decoupling, degree of coupling, and coupling mechanisms, which are analyzed considering the dialectical relationship between distinctiveness and responsiveness. Likewise, the study of organizational couplings has been extensively devel­oped through qualitative methodology with case studies, interviews and documentary reviews. In particular, there are two theoretical frameworks broadly used along with this perspective, the sociological new institutionalism and the theory of normal accidents, which give rise to future research on topics such as decoupling and the normality of accidents, among others. This article contributes to the discussion of organizational ties by highlighting the contemporary relevance of the LCS perspective, its usefulness for understanding current and future organizational issues in the field of Organization Studies, and encouraging greater adoption of LCS analysis in Latin America. Additionally, this paper provides conceptual clarity on the main categories of organizational cou­plings and its operationalization.

The dominant trend in variationist studies of Spanish subject expression is to focus on pronominal subjects, excluding lexical subjects (LSs). Due to such lack of attention to LSs in previous research, the current paper aims to fill this gap and to gain a better understanding of variation between LSs and subject pronouns (SPs). While previous research that analyzes LSs makes a significant contribution to the scholarship on subjects and enriches our understanding of the functions of LSs, a variable context for LSs in the variationist tradition has not heretofore been established. The current paper proposes a variable context methodology for LSs by investigating cases where LSs are produced (e.g. mi mamá trabaja ‘my mom works’), particularly in contexts in which SPs (overt or null) could have alternatively been produced (e.g. ella/∅ trabaja ‘she works’). Overall frequencies, constraints, and pragmatic functions of LSs are discussed.

This paper deals with the reactivation of three test benches of high, medium and low power electric generators for hydraulic energy conversion in the University of Carabobo Hydraulic Laboratory. The method involves three stages: i) Description of three high, medium and low power electric generators for hydraulic energy conversion, ii) Rehabilitation of three high, medium and low power electric generators for hydraulic energy conversion and iii) Evaluation of performance indexes of high, medium and low power electric generators for hydraulic conversion. The results indicate that for the low power electric generator, the position angle of the distributor blades is an experimental factor that has a significant effect on the response variables studied. With respect to the medium and high power electric generators, the most influential factor on operation and power generation is the flow supplied.

The objective of this paper is to evaluate the impact of fiscal instruments for Colombia on two of the country’s main issues: income inequality and informality, phenomena that have been exacerbated by the pandemic. For this purpose, we built a DSGE model whose main differentiating element is the level of liquidity of households. The model carried out various simulations of transfers to households, and we examined the effects of these on different macroeconomic variables. We conclude that for the economy to return to the same fiscal adjustment it had before a transfer, the government will somehow have to increase the productivity of the formal sector, as this increase will have a positive effect on growth, increase income taxes and employment, and decrease informality.

The neorealist approach to institutional change has the merits of emphasising the importance of the Dominant Social Bloc (DSB) in institutions, and of integrating economics, society, and politics in the formation and breakdown of the DSB. Since this approach was not designed for Colombia, it is necessary to integrate certain characteristics, such as economic dependence, armed conflict, and drug trafficking. This paper presents the first theoretical adaptation of the neorealist approach for a Latin American country. This extended theoretical framework evinces the role of crime and violence in providing political stability to an accumulation regime that satisfies the demands of a narrow DSB.

The Great Recession (2008-2013) worsened the labor market position of young Spaniards. despite governments launched labor market reforms in 2010 y 2012 to improve labor stability, permanent employment accounted for only 10 percent of total new contracts. This paper tries to disentangle which factors are hindering the promotion of open-ended contracts to stabilize Spanish young workers into permanent employment. These analysis use panel data from the MCVL (Muestra Continua de Vidas Laborales). The results indicate that, although having an open-ended contract increases the probability of being employed after two years, only 50 percent of these initial contracts survive. The structure of labor demand explains this instability.

The purpose of this reflection paper is to provide a Foucauldian view of the influence of the neoliberal ethos on the rational choices of agents in organizations and how this impacts the tendency to make decisions about deviant behavior. We propose that practices of codes of ethics have less substantive effects and more symbolic effects. The control of corruption occurs in three dimensions: egoism, utilitarianism and opportunism. Codes of ethics and compliance systems, in this sense, possess only the capacity to partially meet each of these requirements, not being enough measure for business integrity assurance. We believe it is essential to distinguish the arguments presented in this paper from the dominant thinking on theories about ethics in organizations. Our interest is to give a politicized response to the discussions raised in the field. The originality of the article resides in the transposition of Foucauldian concepts for practices of control of conducts in the contemporary management. The inadequacy of the normative measures is worked out. Besides, alternative perspectives are proposed to the practices of management for ethical behavior in or­ganizations.

This paper aims to present a literature review that serves as a guide for the analysis of the relationship between socioeconomic conditions and food consumption. First, it shows different interpretations of this relationship from three categories: a) the position that a person occupies in the economic and social system; b) rational and functional aspects of food consumption; c) changes in food consumption and socioeconomic conditions. Then, based on the conclusions drawn from these sections, the analytical balance proposed in this article will be exposed. The paper concludes that there are different micro and macro; material and non-material elements; dynamic; in time and space; that restricts food consumption; thus, it is suggested to the beginner reader of this topic not to lose sight of the vast complexity of the problem.

This paper analyses the scope, origins, justification, and commitments of the extended fund arrangement (EFA) signed by the Ecuadorian government and the IMF in March 2019. This agreement, which represents a little more than a third of Argentina’ Stand-By Agreement, promotes Central Bank independence, austerity, as well as structural adjustment policies, but its basic’ diagnosis omits external sector problems. This paper presents the implications and contradictions of the agreement to promote structural changes in the real sector and how these foster policies that protect the interests of bondholders and bankers.

Introduction: Physicians’ main responsibility is to practice medicine for the benefit of patients. However, there are situations where secondary interests affect this commitment and give rise to conflicts of interest. Objective: To analyze currently available systematic reviews and meta-analyses on conflicts of interest in medicine to summarize relevant evidence in this regard. Material and methods: A literature search was performed in the MEDLINE and LILACS databases using the following search strategy: systematic reviews and meta-analysis on conflicts of interests in medicine published in serialized scientific journals; no publication time or language limits were applied. Studies that met the inclusion criteria were grouped according to the medical activity they assessed, and information on the type and number of studies and conclusions of all publications included in the review was collected. Results: 29 publications were included, and they were classified as follows: studies based on research articles, on clinical practice guidelines, on clinical practice, and on patient-oriented papers. Conclusions: It was found that the authors of the original research papers included in the meta-analyses and systematic reviews analyzed here do not always state if they have conflicts of interest or not. Nevertheless, when said conflicts are reported, they tend to present results favoring the drugs or medical technologies of their sponsor.

This paper presents a conceptual framework for the modelling and simulation of properties, interactions and processes of social systems based on computational templates using discrete event system specification (DEVS) formalism and OMG Systems Modelling Language (SysML) diagrams. No antecedents of this combination were found in the literature, and so this is one of the contributions of this paper. Additionally, this article explains how the principles and rules of SysML can be applied to the analysis of social systems. An example of the proposed framework based on a basic Agent_Zero model is shown. The conceptual framework was built based on a critical literature review, and included new additional elements to create a complete but simple conceptual framework. The codes for the simulations were written in Python 3.

This paper investigates the impact of the unprecedented climate shocks of the 2010 in Colombia on the results of the Saber 11 standardized test for the 2010- 2012 period. By using two unique datasets, this paper contributes to the literature by providing a better estimate of the human capital costs of climate shocks. The findings indicate that the climate shocks occurred on 2010 decreased Saber 11 test scores. The impact was stronger for female students, students from rural areas and students from low-income families. A possible channel of transmission is identified: the destruction of schools.

Cable driven robots have been a widely researched topic in the last few years, this is due to the advantages that they present over conventional parallel robots. In this paper, all the areas of robotic design have been studied for a planar cable driven robot, with the objective of making it parametric, meaning that the design process and mathematical models used in this paper could be used to implement the suggested architecture to solve any specific need. Finally, using the parametric design approach, a prototype was developed and built in order to validate the design process, evaluate the robot’s precision, identify future works and improvements and foresee any trouble that was not considered during the design phase.

Offshore outsourcing by organizations has been gaining momentum, powered by advances in information technology and costs differentials. A review of the literature on the subject, though, shows that those scholars who have focused on offshore outsourcing have centered their attention on the activities of multinational enterprises (MNEs) in the manufacturing and services sectors, leaving behind small and medium enterprises (SMEs). Through a number of propositions, this paper suggests that SMEs could also benefit from offshore outsourcing given their particular characteristics and needs. The paper also discusses the similarities and differences in the motivations that SMEs might have in subcontracting their activities outside their boundaries in comparison to MNEs. Knowing this information is important for foreign suppliers in order to adapt and expand their offerings to the needs of these particular firms.

The majority of components used in aeronautic, automotive or transport industries are subjected to fatigue loads. Those elements should be designed considering the fatigue life. In this paper the geometrical design of a right angle bracket has been simulated by FEM, considering the type of material, the applied load and the geometry of the pieces. The geometry of the right angle bracket has been optimized using the Taguchi’s robust optimization method. As far as the authors know, there are no publications dealing with the use of the Taguchi’s robust optimization method applied to the geometric design of industrial pieces having as output variable the Findley fatigue coefficient. This paper presents a method for determining the critical design parameters to extend the product life of components subject to fatigue loading. This pioneer idea is applicable to any other design or physical or mechanical application so it can be widely used as new methodology to fatigue robust design of mechanical parts and components.

The use of information and telecommunication technologies (ICT) for the development of educational tools such as virtual laboratories has become a valuable teaching support practice in different areas of professional training. Current applications range from virtualization practices in fundamental sciences, to virtual experimentation on specific engineering topics. This paper describes the development of the Virtual Earthquake Engineering Lab (SISMILAB). This lab includes different applications with the objective of becoming an aid in the process of understanding and applying fundamental concepts related to the field of earthquake engineering. The aim of the lab is to strengthen the academic and research experiences of students both inside and outside the classroom. Students have readily used SISMILAB and given positive feedback regarding its effectiveness in conveying concepts and aiding in the visualization and interpretation of results. Finally, the paper discusses the impact of the virtual laboratory based on metrics obtained from questionnaires regarding student and faculty satisfaction.

This paper presents a review on hydrogels applied to agriculture emphasizing on the use of natural fibers. The objectives were to examine, trends in research addressed to identify natural fibers used in hydrogels development and methods for modifying natural fibers, understand factors which determine the water retention capacity of a hydrogel. Consequently, this paper shows some methodologies used to evaluate the hydrogels efficiency and to collect in tables, relevant information in relation to methods of natural fibers modification and hydrogel synthesis. It was found that previous research focused on hydrogels development processed with biodegradable polymers such as starch, chitosan and modified natural fibers, cross-linked with potassium acrylate and acrylamide, respectively. In addition, current researches aimed to obtaining hydrogels with improved properties, which have allowed a resistance to climatic variations and soil physicochemical changes, such as pH, presence of salts, temperature and composition. In fact, natural fibers such as sugarcane, agave fiber and kapok fiber, modified with maleic anhydride, are an alternative to obtain hydrogels due to an increasing of mechanical properties and chemically active sites. However, the use of natural nanofibers in hydrogels, has been a successful proposal to improve hydrogels mechanical and swelling properties, since they give to material an elasticity and rigidity properties. A hydrogel efficiency applied to soil, is measured throughout properties as swellability, mechanical strength, and soil water retention. It was concluded that hydrogels, are an alternative to the current needs for the agricultural sector.

This paper presented a study of abrasive disintegration in a 400 MPa Abrasive Water Jet (AWJ). Abrasive particle size and distribution play a major role in machining and cutting efficiency of abrasive water jets. Tested garnet abrasive, commonly used in the abrasive water jet treatment, and corundum. It is of scientific interest to observe the disintegration of these particles which have been interactive with uncommonly used abrasive materials. Time impact of abrasive grains on the workpiece is very short and not all the grain in the stream of being able to do the work of cutting, you should expect the possibility of recovering the abrasive treatment. Considerable importance is the increase in cutting capacity crushed grains due to reveal new cutting edges. Based on a feasibility study this paper will present some results on achieved cutting data and shows also wear of the used focusing tube - the main part responsible for the formation of the jet.

The recognized biogenic production corresponds to corporal materials, and ethological structures (ichnofossils). Ethological structures include bioturbation, bioerosion, and biogenic granule-classification structures. Biogenic materials and structures traditionally include biogenic aggregates (such as fecal pellets or castings and coprolite grapstones); bioturbation structures or ichno-structures (burrows, tracks, trails, and root penetration structures); biogenic granulo-classification or biostratification structures (algal and bacterial stromatolites of graded bedding of biogenic origin); bioerosion structures (borings, scrapings, and bitings); and biolitites (e.g., reef structures). This paper presents a new classification system for biogenic materials applicable to the fossil record. It summarizes our efforts to standardize terminology, use new and existing terms, correct any contradictions in some terms, and facilitate teaching and learning processes related to this subject. In our proposal, biogenic production is used for any materials or structures produced, built, modified, or used by living organisms. Biogenic production includes the following five groups: direct production (corporal, biodeposition, bioexhudation, and bioclaustration materials and structures); bio-modified materials and structures (predation, bioerosion, and bioturbation); bio-built materials and structures (biofoodcaches, bioconstructions, and biostratification structures); microbial induced materials and structures; and biotools. All types of biogenic production have examples in the sedimentary record.

The transportation sector has been fundamental in Colombia and faces serious consequences in terms of traffic accidents. This paper examines the relationship between accidentability and most outstanding road infrastructure factors in ten urban stretches of Neiva in the period 2017-2018, following the inclusion and exclusion criteria of the International Road Assessment Program (IRAP) for developing countries in order to characterize the state of road infrastructure of the selected points. The results showed that the central sections of the city tend to be related to the day, time, type of vehicle and victim, attribute and direction of the road. The motorcyclist was the road actor most vulnerable to injuries and fatalities, Saturday and 8:00 am was where more crashes occurred. The road infrastructure factors contributing to accidents highlight the relevance of the environment in the city.

Keroplatidae is a family of Diptera that is poorly known and with scarce previous studies in Colombia, with only five species in four genera, and another five genera with non-identified species. This paper provides an extensive revision of the Keroplatidae from Colombia, with specimens collected along different altitudinal gradients, from Amazonian areas to Andean mountains. We found 17 genera, nine of these represent new records for Colombia (Cerotelion, Heteropterna, Placoceratias, Platyroptilon, Lapyruta, Micrapemon, Plautyra, Pyrtaula and Xenoplatyura). Additionally, the distribution in Colombia is extended for the genera Isoneuromyia, Keroplatus, Lyprauta, Macrocera, Neoceroplatus, Neoditomyia, Neoplatyura and Proceroplatus. For each genus we present a diagnosis, annotations of their biology based on literature and new field observations, and a distribution map.

This paper focuses upon a place called the Vertical Village, a building in the center of Rio de Janeiro inhabited exclusively by indigenous peoples from different ethnic groups belonging to different parts of the country. In this paper, we discuss questions related to the experience of being indigenous in a city, the construction of a residential space as a village, and the constitution of indigenous identity in the urban context. Following the paths of three inhabitants of the building, the questions considered emerge from their transiting between cities and villages, frontiers either real or imaginary, prejudices and expectations of indigenous identity.

This paper focuses upon a place called the Vertical Village, a building in the center of Rio de Janeiro inhabited exclusively by indigenous peoples from different ethnic groups belonging to different parts of the country. In this paper, we discuss questions related to the experience of being indigenous in a city, the construction of a residential space as a village, and the constitution of indigenous identity in the urban context. Following the paths of three inhabitants of the building, the questions considered emerge from their transiting between cities and villages, frontiers either real or imaginary, prejudices and expectations of indigenous identity.

This paper provides insights into how to approach the assessment of scientific production efficiency using Data Envelopment Analysis (DEA). The methods employed in this paper take into account both the CCR and Assurance Region (AR) models, which are based on science, technology and innovation (STI) indicators. The sample focuses on the departments in Colombia as well as the Capital District (C.D.). The research concludes that both models calculate the efficiency of the units of analysis. Furthermore, according to the country’s STI targets, AR is susceptible to hierarchies generated within the variables.