109 research outputs found

    Factores determinantes en la implementación de manufactura esbelta utilizando la teoría del desarrollo psicosocial: caso aplicado en una empresa del sector acerero en Nuevo León (Key factors in the implementation of lean manufacturing using the theory of psychosocial development: case applied to a steel company in Nuevo León)

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    Abstract. This paper presents a case of the implementation of some lean manufacturing initiatives such as lean Kaizen events, improvement project, standardization, training center, "Stage Gate", ideas and suggestion, ISO 14000, ISO 17025 in a steel company in Nuevo León. This study used a diagnostic tool proposed by Hiroyuki Hirano to determine the degree of maturity of the initiative of continuous improvement, and compare against the steps suggested by the main authors in this issue. The above determine the main steps and factors of success and crises and barriers that were presented. Also, we propose an adaptation of the model proposed by Erik Erikson to organism principle, which takes into account at every stage life cycle. Resumen. Este artículo presenta un estudio de caso de la implementación de algunas Iniciativas de Manufactura Esbelta como Lean- Eventos Kaizen, Proyectos de Mejora DMAIC, Equipos participativos, Estandarización, Centro de entrenamiento, Desarrollo de productos “Stage Gate”, Sistema de Ideas, ISO 14000, ISO 17025 en una empresa de acero en Nuevo León. Para dicho estudio se usó la herramienta de diagnóstico propuesta por Hiroyuki Hirano para determinar el grado de madurez de la iniciativa de mejora continua, y se compara contra los pasos sugeridos por los principales autores del tema. De lo anterior se puede determinar los principales pasos y factores de éxito en la implementación así como las crisis y barreras que se presentaron. Además proponemos una adaptación del principio organísmico de las personas propuesto por Erik Erikson al Ciclo de vida de las iniciativas, donde toma en cuenta en cada estadio

    Síntesis y caracterización fisicoquímica de circonia promovida con ácido tungstofosfórico y ácido bórico utilizada como catalizador en la isomerización de n-pentano

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    En este trabajo se muestra la preparación, caracterización y evaluación de la actividad catalítica de materiales del tipo ZrO2 promovida con ácido tungstofosfórico y ácido bórico. El Zr(OH)4 se sintetizó por el método sol-gel utilizando como precursores al n-butóxido de circonio y 1-butanol, manteniendo un pH = 8 durante la síntesis. El Zr(OH)4 se impregnó con un 15% en pesodel agente ácido, calcinado a 600 ºC e impregnado  posteriormente con 0,5% en peso de platino. Se observó que los iones [PW12O40]3– y [BO3]3– permanecen fuertementeenlazados a la superficie de la ZrO2 inhibiendo el crecimiento de la partícula, retardando la sinterización del material y la aparición de la fase monoclínica.Además, con la incorporación de estos dopantes se incrementó la acidez total del material, específicamente la población de sitios ácidos fuertes, siendo este tipo de sitios los predominantes en las muestras acidificadas.La acidez desarrollada por los materiales fue la adecuada para lograr catalizar la reacción de isomerización de n-pentano con conversiones superiores al 20% y selectividades hacia el isopentano que fluctuaron alrededor del 90%

    Instrumentation and automation system defects detection

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    UK: У статті подано методику, що використовується для автоматизації механотронної системи, з метою отримання інформації про стан зубів. Автоматизована система включає мікроконтролер, що дозволяє її реконфігурацію і порти комунікації та уведеннявиведення. Було розроблено систему вимірювання відстаней, яка дозволяє мікроконтролеру надавати інформацію про поточний стан кожної осі механізму. Розроблено програми управління, що забезпечують вільне переміщення механізму по кожній осі. Таким чином, програми забезпечують незалежне управління, що, в свою чергу, сприяє позиціонуванню механізму в будь-якій точці робочого простору для отримання інформації про стан зубів. EN:This paper presents the methodology used for the automation of a mechatronic system, which will be used for information of teeth, the work was done using a microcontroller, which allows the reconfiguration of the system, the use of different ports communication and input-output ports, It was made a distance measuring system which allows the microcontroller to provide information about current position of each axis of the mechanism. Control routines are performed which allow manipulation mechanism on each axis independently of thus obtained independent control shaft which facilitates its positioning in any point of the working space of the mechanism to obtain about the theet

    Acute Variceal Bleeding: Does Octreotide Improve Outcomes in Patients with Different Functional Hepatic Reserve?

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    Background. Current guidelines do not differentiate in the utilization of vasoactive drugs in patients with cirrhosis and acute variceal bleeding (AVB) depending on liver disease severity. Material and methods. In this retrospective study, clinical outcomes in 100 patients receiving octreotide plus endoscopic therapy (ET) and 216 patients with ET alone were compared in terms of failure to control bleeding, in-hospital mortality, and transfusion requirements stratifying the results according to liver disease severity by Child-Pugh (CP) score and MELD. Results. In patients with CP-A or those with MELD < 10 octreotide was not associated with a better outcome compared to ET alone in terms of hospital mortality (CP-A: 0.0 vs. 0.0%; MELD < 10: 0.0 vs. 2.9%, p = 1.00), failure to control bleeding (CP-A: 8.7 vs. 3.7%, p = 0.58; MELD < 10: 5.3 vs. 4.3%, p = 1.00) and need for transfusion (CP-A: 39.1 vs. 61.1%, p = 0.09; MELD < 10: 63.2 vs. 62.9%, p = 1.00). Those with severe liver dysfunction in the octreotide group showed better outcomes compared to the non-octreotide group in terms of hospital mortality (CP-B/C: 3.9 vs. 13.0%, p = 0.04; MEL

    Mollicutes antibiotic resistance profile and presence of genital abnormalities in couples attending an infertility clinic.

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    OBJECTIVE: The present study aimed to identify Mollicutes infection in the reproductive system. We also examined the microbiological, biochemical, and antimicrobial profiles of Mollicutes infection, which are potentially associated with clinical reproductive abnormalities causing infertility in couples. METHODS: Thirty-seven couples who were attending an infertility clinic were enrolled. Detection of genital mycoplasmas was performed in cervicovaginal samples or male urethral swabs. Microbiological culture and biochemical and antimicrobial profiles were characterized using a Mycoplasma kit. The results were associated with reproductive abnormalities, as assessed by medical specialists from the infertility clinic. RESULTS: Up to 28.3% of all biological samples (n = 74) showed positive cultures. Bacterial isolates were Ureaplasma urealyticum (71.4%), Mycoplasma hominis (9.5%), or coinfections (19%). Most Mollicutes showed significant resistance to fluoroquinolones, macrolides, and tetracycline; and showed susceptibility to doxycycline, josamycin, and pristinamycin. The presence of resistant strains to any antibiotic was significantly associated with genital abnormalities (χ2 test, relative risk = 11.38 [95% confidence interval: 5.8-22.9]), particularly in women. The highest statistical association was found for macrolide-resistant strains. CONCLUSION: The microbiological antibiotic resistance profile is epidemiologically associated with abnormalities of the reproductive system in couples attending an infertility clinic

    Worldwide trends in the burden of asthma symptoms in school-aged children: Global Asthma Network Phase I cross-sectional study

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    Background: Asthma is the most common chronic disease in children globally. The Global Asthma Network (GAN) Phase I study aimed to determine if the worldwide burden of asthma symptoms is changing. Methods: This updated cross-sectional study used the same methods as the International study of Asthma and Allergies in Childhood (ISAAC) Phase III. Asthma symptoms were assessed from centres that completed GAN Phase I and ISAAC Phase I (1993–95), ISAAC Phase III (2001–03), or both. We included individuals from two age groups (children aged 6–7 years and adolescents aged 13–14 years) who self-completed written questionnaires at school. We estimated the 10-year rate of change in prevalence of current wheeze, severe asthma symptoms, ever having asthma, exercise wheeze, and night cough (defined by core questions in the questionnaire) for each centre, and we estimated trends across world regions and income levels using mixed-effects linear regression models with region and country income level as confounders. Findings: Overall, 119 795 participants from 27 centres in 14 countries were included: 74 361 adolescents (response rate 90%) and 45 434 children (response rate 79%). About one in ten individuals of both age groups had wheeze in the preceding year, of whom almost half had severe symptoms. Most centres showed a change in prevalence of 2 SE or more between ISAAC Phase III to GAN Phase I. Over the 27-year period (1993–2020), adolescents showed a significant decrease in percentage point prevalence per decade in severe asthma symptoms (–0·37, 95% CI –0·69 to –0·04) and an increase in ever having asthma (1·25, 0·67 to 1·83) and night cough (4·25, 3·06 to 5·44), which was also found in children (3·21, 1·80 to 4·62). The prevalence of current wheeze decreased in low-income countries (–1·37, –2·47 to –0·27], in children and –1·67, –2·70 to –0·64, in adolescents) and increased in lower-middle-income countries (1·99, 0·33 to 3·66, in children and 1·69, 0·13 to 3·25, in adolescents), but it was stable in upper-middle-income and high-income countries. Interpretation: Trends in prevalence and severity of asthma symptoms over the past three decades varied by age group, country income, region, and centre. The high worldwide burden of severe asthma symptoms would be mitigated by enabling access to effective therapies for asthma. Funding: International Union Against Tuberculosis and Lung Disease, Boehringer Ingelheim New Zealand, AstraZeneca Educational Grant, National Institute for Health Research, UK Medical Research Council, European Research Council, and Instituto de Salud Carlos III
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