Sobre (vivência) e mortalidade de pequenos negócios: o caso de mercados varejistas potiguares

This paper‟s starting point was the objective of understanding the relation between the reasons pointed out by small businesses owners for the continuity or shutdown of their businesses, and the reasons presented by the Environmental Theories. The paper discusses the Environmental Theories understand that it is supported by a systemic metaphor speech, discussing the theme in terms of organizational survival and mortality . The text reviews the literature showing the changes in the administrative thinking regarding the organization versus environment relation, and presenting general ideas about the micro and small businesses. In methodological terms, the qualitative approach was used in the research. Regarding the data collection technique, an in-depth thematic interview was used. It was carried out considering the elements of the techniques of life history and oral history, always giving priority to real world related narratives told by the interviewed subjects. The empirical corpus of the research was made up of seven owners of small retail businesses in two Potiguar cities: Natal and Mossoró. The interpretative and analytical process focused, at first, on the reflexive dialogue with each one of the owners‟ professional life history and business management experience, constituting the first level of analysis: reflections on individual narratives; and, afterwards, the interpretative process was developed through the analysis of all the subjects‟ statements, identifying the recurring themes and constituting the second level of analysis: reflection on the totalizing narrative. The themes identified in the totalizing narrative, that refer to the continuity of the businesses are: evolution, control, fidelity, liking what one does for a living. The themes that came up as reasons for shutdown are: lack of empathy with the business, lack of evolution, competition problems, suppliers and the government. The text synthesizes its comprehensions affirming that the reasons associated with continuity and shutdown of small markets, for this group of owners specifically, come up as a permanent tension between the volunteerism (quite human) and the determinism (systemic). The tension is shown in testimonies that at the same time evoke the organicist systemic logic through the themes evolution/no evolution, and also counterpoints with themes related to the interested human action, based on desires, feelings and personal convictions such as: liking what one does/ lack of empathy. As for the reflexive dialogue between the postulates of the Environmental Theories and the narratives, the results make it possible to affirm that, differently from the tension expressed by the subjects while talking about their reasons, the reasons associated with survival and mortality of businesses according to the Environmental Theories are theoretically polarized, seeming to preach options that are stagnated and shaping towards the subjects involved in the organization-environment relation

Construção, caracterização e aplicação de eletrodos para descarga por arco de cátodo oco

The system built to characterize electrodes and, consequently, deposited fine films are constituted by a hollow cathode that works to discharges and low pressures (approximately 10-3 to 5 mbar), a source DC (0 to 1200 V), a cylindrical camera of closed borossilicato for flanges of stainless steel with an association of vacuum bombs mechanical and spread. In the upper flange it is connected the system of hollow cathode, which possesses an entrance of gas and two entrances for its refrigeration, the same is electrically isolated of the rest of the equipment and it is polarized negatively. In front of the system of hollow cathode there is a movable sample in stainless steel with possibility of moving in the horizontal and vertical. In the vertical, the sample can vary its distance between 0 and 70 mm and, in the horizontal, can leave completely from the front of the hollow cathode. The sample and also the cathode hollow are equipped with cromel-alumel termopares with simultaneous reading of the temperatures during the time of treatment. In this work copper electrodes, bronze, titanium, iron, stainless steel, powder of titanium, powder of titanium and silício, glass and ceramic were used. The electrodes were investigated relating their geometry change and behavior of the plasma of the cavity of hollow cathode and channel of the gas. As the cavity of hollow cathode, the analyzed aspects were the diameter and depth. With the channel of the gas, we verified the diameter. In the two situations, we investigated parameters as flow of the gas, pressure, current and applied tension in the electrode, temperature, loss of mass of the electrode with relationship at the time of use. The flow of gas investigated in the electrodes it was fastened in a work strip from 15 to 6 sccm, the constant pressure of work was among 2.7 to 8 x 10-2 mbar. The applied current was among a strip of work from 0,8 to 0,4 A, and their respective tensions were in a strip from 400 to 220 V. Fixing the value of the current, it was possible to lift the curve of the behavior of the tension with the time of use. That curves esteem in that time of use of the electrode to its efficiency is maximum. The temperatures of the electrodes were in the dependence of that curves showing a maximum temperature when the tension was maximum, yet the measured temperatures in the samples showed to be sensitive the variation of the temperature in the electrodes. An accompaniment of the loss of mass of the electrode relating to its time of use showed that the electrodes that appeared the spherical cavities lost more mass in comparison with the electrodes in that didn't appear. That phenomenon is only seen for pressures of 10-2 mbar, in these conditions a plasma column is formed inside of the channel of the gas and in certain points it is concentrated in form of spheres. Those spherical cavities develop inside of the channel of the gas spreading during the whole extension of the channel of the gas. The used electrodes were cut after they could not be more used, however among those electrodes, films that were deposited in alternate times and the electrodes that were used to deposit films in same times, those films were deposited in the glass substrata, alumina, stainless steel 420, stainless steel 316, silício and steel M2. As the eletros used to deposit films in alternate time as the ones that they were used to deposit in same times, the behavior of the thickness of the film obeyed the curve of the tension with relationship the time of use of the electrode, that is, when the tension was maximum, the thickness of the film was also maximum and when the tension was minimum, the thickness was minimum and in the case where the value of the tension was constant, the thickness of the film tends to be constant. The fine films that were produced they had applications with nano stick, bio-compatibility, cellular growth, inhibition of bacterias, cut tool, metallic leagues, brasagem, pineapple fiber and ornamental. In those films it was investigated the thickness, the adherence and the uniformity characterized by sweeping electronic microscopy. Another technique developed to assist the production and characterization of the films produced in that work was the caloteste. It uses a sphere and abrasive to mark the sample with a cap impression, with that cap form it is possible to calculate the thickness of the film. Through the time of life of the cathode, it was possible to evaluate the rate of waste of its material for the different work conditions. Values of waste rate up to 3,2 x 10-6 g/s were verified. For a distance of the substratum of 11 mm, the deposited film was limited to a circular area of 22 mm diameter mm for high pressures and a circular area of 75 mm for pressure strip. The obtained films presented thickness around 2,1 µm, showing that the discharge of arch of hollow cathode in argon obeys a curve characteristic of the tension with the time of life of the eletrodo. The deposition rate obtained in this system it is of approximately 0,18 µm/min

Nitretação iônica sem efeito de borda :desenvolvimento e avaliação de uma nova técnica

The ionic nitriding process presents some limitations related with the control of the thickness of the layer and its uniformity. Those limitations that happen during the process, are produced due to edge effects, damage caused by arcing arc and hollow cathode, mainly in pieces with complex geometry and under pressures in excess of 1 mbar. A new technique, denominated ASPN (active screen shapes nitriding) it has been used as alternative, for offering many advantages with respect to dc plasma conventional. The developed system presents a configuration in that the samples treated are surrounded by a large metal screen at high voltage cathodic potencials, (varying between 0 and 1200V) and currents up to 1 A. The sample is placed in floting potential or polarized at relatively lower bias voltages by an auxiliary source. As the plasma is not formed directly in the sample surface but in the metal screen, the mentioned effects are eliminated. This mechanism allows investigate ion of the transfer of nitrogen to the substrate. Optical and electronic microscopy are used to exam morphology and structure at the layer. X-ray difration for phase identification and microhardness to evaluate the efficiency of this process with respect to dc conventional nitriding

Excitações em cristais fotônicos unidimensionais

In this work, we present a theoretical study of the propagation of electromagnetic waves in multilayer structures called Photonic Crystals. For this purpose, we investigate the phonon-polariton band gaps in periodic and quasi-periodic (Fibonacci-type) multilayers made up of both positive and negative refractive index materials in the terahertz (THz) region. The behavior of the polaritonic band gaps as a function of the multilayer period is investigated systematically. We use a theoretical model based on the formalism of transfer matrix in order to simplify the algebra involved in obtaining the dispersion relation of phonon-polaritons (bulk and surface modes). We also present a quantitative analysis of the results, pointing out the distribution of the allowed polaritonic bandwidths for high Fibonacci generations, which gives good insight about their localization and power laws. We calculate the emittance spectrum of the electromagnetic radiation, in THZ frequency, normally and obliquely incident (s and p polarized modes) on a one-dimensional multilayer structure composed of positive and negative refractive index materials organized periodically and quasi-periodically. We model the negative refractive index material by a effective medium whose electric permittivity is characterized by a phonon-polariton frequency dependent dielectric function, while for the magnetic permeability we have a Drude like frequency-dependent function. Similarity to the one-dimensional photonic crystal, this layered effective medium, called polaritonic Crystals, allow us the control of the electromagnetic propagation, generating regions named polaritonic bandgap. The emittance spectra are determined by means of a well known theoretical model based on Kirchoff s second law, together with a transfer matrix formalism. Our results shows that the omnidirectional band gaps will appear in the THz regime, in a well defined interval, that are independent of polarization in periodic case as well as in quasiperiodic case

Desenvolvimento e caracterização de dispositivos para reposição de filmes finos por descarga em cátodo oco

In the present work we use a plasma jet system with a hollow cathode to deposit thin TiO2 films on silicon substrates as alternative at sol-gel, PECVD, dip-coating e magnetron sputtering techniques. The cylindrical cathode, made from pure titanium, can be negatively polarized between 0 e 1200 V and supports an electrical current of up to 1 A. An Ar/O2 mixture, with a total flux of 20 sccm and an O2 percentage ranging between 0 and 30%, is passed through a cylindrical hole machined in the cathode. The plasma parameters and your influence on the properties of deposited TiO2 films and their deposition rate was studied. When discharge occurs, titanium atoms are sputtered/evaporated. They are transported by the jet and deposited on the Si substrates located on the substrate holder facing the plasma jet system at a distance ranging between10 and 50 mm from the cathode. The working pressure was 10-3 mbar and the deposition time was 10 -60 min. Deposited films were characterized by scanning electron microscopy and atomic force microscopy to check the film uniformity and morphology and by X-ray diffraction to analyze qualitatively the phases present. Also it is presented the new dispositive denominate ionizing cage, derived from the active screen plasma nitriding (ASPN), but based in hollow cathode effect, recently developed. In this process, the sample was involved in a cage, in which the cathodic potential was applied. The samples were placed on an insulator substrate holder, remaining in a floating potential, and then it was treated in reactive plasma in hollow cathode regime. Moreover, the edge effect was completely eliminated, since the plasma was formed on the cage and not directly onto the samples and uniformity layer was getting in all sampl

Relação das condições socioeconômicas com as condições de saúde bucal em capitais brasileiras

Despite the improvement of Brazilian s living conditions in recent decades, this improvement occurred in a polarized way between groups of better social position. Then, there is still a health inequity´s panorama in Brazil which encompasses the oral health state. This panorama instigated the attainment of this ecological study that aimed to evaluate the relationship of socioeconomic conditions, and public health policies with oral health status in Brazilian capitals. Thus, we performed factor analysis and linear regression using oral health indicators collected from SB Brasil 2010, of socioeconomic conditions from Brazilian Census 2010 and related to water´s supply fluoridation from SISAGUA. Factor analysis with indicators of living conditions revealed two common factors, economic deprivation and socio-sanitary condition. Economic deprivation showed statistically significant positive correlation with DMFT 12 years (p= 0,03) and mean missing teeth (p = 0,002) and negative correlation with caries-free population (p=0,012). Socio-sanitary negatively correlated with DMFT (p <0,0001) and a positive correlation with caries-free population (p = 0.002). Fluoridated water had a significant association with DMFT (p <0,0001), mean missing teeth (p <0,0001) and caries free population (p <0.0001). Multiple linear regression analysis for the DMFT of capital was estimated by socio-sanitary condition and fluoridation, adjusted by economic deprivation, whereas the model for the mean missing teeth was estimated only by fluoridation and economic deprivation, and finally the model the rate for the population free of caries in Brazilian capitals was estimated by economic and socio-sanitary status adjusted fluoridated water supply. Therefore, factors related to living conditions and public policies are intrinsically linked to tooth decay issues. Thus, actions, beyond dental care assistance, must be development to impact positively in social and economic conditions, especially, between the most vulnerable populations