Desperdícios na cadeia logística no âmbito industrial

Projecto apresentado ao Instituto Politécnico do Porto para obtenção do Grau de Mestre em Logística Orientada por Prof. Doutor Gouveia

Comportamento à fadiga de juntas soldadas de aços tipo 460M com fios fluxados

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Neonatal mortality: description and effect of hospital of birth after risk adjustment

OBJECTIVE: To assess the effect of hospital of birth on neonatal mortality. METHODS: A birth cohort study was carried out in Pelotas, Southern Brazil, in 2004. All hospital births were assessed by daily visits to all maternity hospitals and 4558 deliveries were included in the study. Mothers were interviewed regarding potential risk factors. Deaths were monitored through regular visits to hospitals, cemeteries and register offices. Two independent pediatricians established the underlying cause of death based on information obtained from medical records and home visits to parents. Logistic regression was used to estimate the effect of hospital of birth, controlling for confounders related to maternal and newborn characteristics, according to a conceptual model. RESULTS: Neonatal mortality rate was 12.7‰ and it was highly influenced by birthweight, gestational age, and socioeconomic variables. Immaturity was responsible for 65% of neonatal deaths, followed by congenital anomalies, infections and intrapartum asphyxia. Adjusting for maternal characteristics, a three-fold increase in neonatal mortality was seen between similar complexity hospitals. The effect of hospital remained, though lower, after controlling for newborn characteristics. CONCLUSIONS: Neonatal mortality was high, mainly related to immaturity, and varied significantly across maternity hospitals. Further investigations comparing delivery care practices across hospitals are needed to better understand NMR variation and to develop strategies for neonatal mortality reduction.

Factors associated with depression symptoms in high school students in São Paulo, Brazil

OBJECTIVE: To assess factors associated with depression symptoms in high school students. METHODS: A cross-sectional study involving high school students was conducted in the city of São Paulo, Brazil, 2001. A total of 724 students aged 14-18 years answered questionnaires on life and health conditions. Another questionnaire was applied to working (44.8%) and unemployed (22.9%) students to collect information on working conditions. Factors associated to depressive disorders were analyzed using multiple logistic regression controlled for occupational status. RESULTS: Overall prevalence rate of depression was 7.5%. Rates according to gender were 39 (10.3%) in females and 15 (4.3%) in males. The multiple logistic regression analysis showed that factors associated with depressive disorders were: poor self-perception of health (OR=5.78), being female (OR = 2.45), and alcohol consumption (OR=2.35). CONCLUSIONS: The study results showed that sociodemographic, lifestyle and health variables were associated with symptoms of depression in this population. These ndings suggest that it is important to have mental health professionals available in high schools for early detection of mental conditions and student counseling.

Clinical and functional aspects of work-related musculoskeletal disorders among active workers

OBJECTIVE: To evaluate musculoskeletal disorders among active industrial workers. METHODS: The study was carried out in São Carlos, Southeastern Brazil, in 2005. One hundred and thirty-four female workers were physically evaluated and answered questions about their physical symptoms, filled out a pain scale and gave responses in the Oswestry Disability Questionnaire, and the Work Ability Index questionnaire. The data were analyzed descriptively, and in correlation tests and through applying logistic regression. The outcome was evaluated in relation to the perceptions of pain, symptoms, physical assessment, ability to work and disability. RESULTS: Clinical evaluations and sick leave presented positive correlations with the subjective variables. The Work Ability Index presented a negative correlation with the physical disability index (r=-0.69). Symptoms reported at the time of the assessment presented a good correlation with the results from the pain scale and the clinical findings. Previous sick leave showed an association with disability (OR=1.13; 95% CI:1.08;1.18). CONCLUSION: Symptom reports and pain scales may be useful for assessing current conditions at the time of evaluating individuals with work-related musculoskeletal disorders, as they are easier to apply. In more severe cases of such injuries, clinical and functional evaluations and questionnaires such as those relating to ability to work and disability are preferable. Precise and specific evaluations of these disorders may contribute towards fairer legal and administrative decisions.

Helmet use among motorcyclists: observational study in the city of Mar del Plata, Argentina

The objective of the study was to assess the use of helmets in a community where helmet use is mandatory but low as there is no police enforcement. A sample comprising 451 motorcyclists in the city of Mar del Plata, Argentina, was studied in 2006. The following variables were studied: gender, type of motorcycle, weather conditions, time of the day, city area and type of road where motorcyclists traveled. Data were analyzed through a multiple logistic regression model. An overall 40% prevalence (95% CI: 35.5;44.5) of helmet use was found. Higher rates of helmet use were seen among women, and under unfavorable weather conditions, lower rates were found in the city outskirts, and variable use was seen according to the type of motorcycle. There is a need to improve law enforcement and to promote education of motorcyclists.

Risk factors for sudden infant death syndrome in a developing country

OBJECTIVE: To analyze whether previously identified risk factors for sudden death syndrome have a significant impact in a developing country. METHODS: Retrospective longitudinal case-control study carried out in Porto Alegre, Southern Brazil. Cases (N=39) were infants born between 1996 and 2000 who died suddenly and unexpectedly at home during sleep and were diagnosed with sudden death syndrome. Controls (N=117) were infants matched by age and sex who died in hospitals due to other conditions. Data were collected from postmortem examination records and questionnaires answers. A conditional logistic model was used to identify factors associated with the outcome. RESULTS: Mean age at death of cases was 3.2 months. The frequencies of infants regarding gestational age, breastfeeding and regular medical visits were similar in both groups. Sleeping position for most cases and controls was the lateral one. Supine sleeping position was found for few infants in both groups. Maternal variables, age below 20 years (OR=2, 95% CI: 1.1; 5.1) and smoking of more than 10 cigarettes per day during pregnancy (OR=3, 95% CI: 1.3; 6.4), significantly increased the risk for the syndrome. Socioeconomic characteristics were similar in both groups and did not affect risk. CONCLUSIONS: Infant-maternal and socioeconomic profiles of cases in a developing country closely resembled the profile described in the literature, and risk factors were similar as well. However, individual characteristics were identified as risks in the population studied, such as smoking during pregnancy and maternal age below 20 years.

Oral health, hygiene practices and oral cancer

OBJECTIVE: To assess the association between oral health and hygiene practices and oral cancer. METHODS: Hospital-based case-control study in the metropolitan area of São Paulo, southeastern Brazil, from 1998 to 2002. A total 309 patients with squamous cell carcinoma of the mouth and the pharynx and 468 controls matched by sex and age were included in the study. Cases were recruited in seven reference hospitals and controls were selected in five out of the seven participating hospitals. Detailed information on smoking, alcohol consumption, schooling, oral health status and hygiene practices were obtained through interviews. Odds ratios (OR) and 95% confidence intervals (95% CI), adjusted by sex, age, schooling, smoking, alcohol consumption as well as the variables oral health status and hygiene practices were estimated using unconditional logistic regression analyses. RESULTS: The use of complete dental prosthesis was not associated with oral cancer but regular gum bleeding showed a strong association (OR 3.1; 95% CI 1.2-7.9). Those who never attended a dental visit were more likely to have oral cancer (OR 2.5; 95% CI 1.3-4.8). Daily mouthwash use showed a stronger association to pharynx (OR 4.7; 95% CI 1.8-12.5) than mouth cancer (OR 3.2; 95% CI 1.6-6.3). CONCLUSIONS: Gum bleeding, no dental care, and daily mouthwash use were factors associated with oral cancer regardless of tobacco and alcohol consumption.

Comorbidity adjustment index for the international classification of diseases, 10

OBJECTIVE: To develop a Charlson-like comorbidity index based on clinical conditions and weights of the original Charlson comorbidity index. METHODS: Clinical conditions and weights were adapted from the International Classification of Diseases, 10th revision and applied to a single hospital admission diagnosis. The study included 3,733 patients over 18 years of age who were admitted to a public general hospital in the city of Rio de Janeiro, southeast Brazil, between Jan 2001 and Jan 2003. The index distribution was analyzed by gender, type of admission, blood transfusion, intensive care unit admission, age and length of hospital stay. Two logistic regression models were developed to predict in-hospital mortality including: a) the aforementioned variables and the risk-adjustment index (full model); and b) the risk-adjustment index and patient's age (reduced model). RESULTS: Of all patients analyzed, 22.3% had risk scores >1, and their mortality rate was 4.5% (66.0% of them had scores >1). Except for gender and type of admission, all variables were retained in the logistic regression. The models including the developed risk index had an area under the receiver operating characteristic curve of 0.86 (full model), and 0.76 (reduced model). Each unit increase in the risk score was associated with nearly 50% increase in the odds of in-hospital death. CONCLUSIONS: The risk index developed was able to effectively discriminate the odds of in-hospital death which can be useful when limited information is available from hospital databases.

HIV infection and related risk behaviors in a community of recyclable waste collectors of Santos, Brazil

OBJECTIVE: To estimate the seroprevalence of HIV, hepatitis B and C and syphilis and to describe risk behaviors associated to their transmission among recyclable waste collectors. METHODS: A seroepidemiological survey was carried out in the city of Santos, Southeastern Brazil, in 2005. A total of 315 individuals were enrolled in the survey, of which 253 subjects underwent serological testing HIV, hepatitis B and C and syphilis. Statistical analysis consisted of univariate and bivariate analyses (cross-tabulation and odds ratio) and multivariate analysis (by logistic regression), relating HIV infection with established risk behaviors and seropositivity. RESULTS: Overall seroprevalences were: HIV, 8.9%; hepatitis B, 34.4%; hepatitis C, 12.4%; and syphilis, 18.4%. Subjects were characterized by a predominance of males with low educational and economic levels, subjected to parenteral and sexual exposures to HIV and other sexually transmitted infections. Multivariate analysis results indicated that risk factors for both sexually and parenterally related exposure were significantly associated with HIV in this community. CONCLUSIONS: Seroprevalences found in the study were approximately 10 to 12 times higher than the national average. These communities are socially marginalized and generally not recognized by national programs as potentially endangered populations.

Missed opportunities for congenital syphilis and HIV perinatal transmission prevention

OBJECTIVE: To estimate the prevalence of missed opportunities for congenital syphilis and HIV prevention in pregnant women who had access to prenatal care and to assess factors associated to non-testing of these infections. METHODS: Cross-sectional study comprising a randomly selected sample of 2,145 puerperal women who were admitted in maternity hospitals for delivery or curettage and had attended at least one prenatal care visit, in Brazil between 1999 and 2000. No syphilis and/or anti-HIV testing during pregnancy was a marker for missed prevention opportunity. Women who were not tested for either or both were compared to those who had at least one syphilis and one anti-HIV testing performed during pregnancy (reference category). The prevalence of missed prevention opportunity was estimated for each category with 95% confidence intervals. Factors independently associated with missed prevention opportunity were assessed through multinomial logistic regression. RESULTS: The prevalence of missed prevention opportunity for syphilis or anti-HIV was 41.2% and 56.0%, respectively. The multivariate analysis showed that race/skin color (non-white), schooling (<8 years), marital status (single), income (<3 monthly minimum wages), having sex during pregnancy, history of syphilis prior to the current pregnancy, number of prenatal care visits (<6), and last prenatal visit before the third trimester of gestation were associated with an increased risk of missed prevention opportunity. A negative association with missed prevention opportunity was found between marital status (single), prenatal care site (hospital) and first prenatal visit in the third trimester of gestation. CONCLUSIONS: High rates of non-tested women indicate failures in preventive and control actions for HIV infection and congenital syphilis. Pregnant women have been discontinuing prenatal care at an early stage and are failing to undergo prenatal screening for HIV and syphilis.

Use of analgesics in adults with pain complaints: prevalence and associated factors, Turkey

OBJECTIVE: Use of analgesics has been increasingly recognized as a major public health issue with important consequences in Turkey. The objective of the study was to determine the prevalence and patterns of analgesics usage and associated factors in adults with pain complaints. METHODS: A cross-sectional study was conducted in 15 cities selected from five demographic regions in Turkey. The study sample population comprised 1.909 adults 18-65 age groups suffering from pain. The sampling method was multi-step stratified weighted quota-adjusted sampling. Data were collected by face-to-face interviews using a semi-structured survey questionnaire consisting of 28 questions. Odds ratios were produced by logistic regression analyses. RESULTS: The prevalence of analgesic use was 73.1%, and it was higher in females (75.7%; p<0.05), in subjects 45-54 years (81.4%; p<0.05), in subjects in rural areas (74.6%; p<0.05), in subjects in northern region (84.3%; p<0.05), in illiterate subjects (79.1%; p>0.05), and in subjects of lower socioeconomic status (74.1%; p>0.05). One in ten of the participants used non-prescription analgesics. Non-prescription analgesics were more prevalent among the 55-65 age groups (18.1%; p<0.05), among female (11.6%; p>0.05), among the urban population (10.7%; p>0.05), and in subjects of lower middle socioeconomic status (13.2%; p<0.05). Logistic regression showed statistically significant ORs only for age groups, duration of education, socioeconomic status, and demographic regions (p<0.05). CONCLUSIONS: The results showed that the prevalence of analgesic use and prescription analgesic use is high in Turkey, and their use is related to sociodemographic characteristics.

Proposta de metodologia usando regressões lineares no cálculo dos efeitos vibratórios do rebentamento de explosivos

Este trabalho apresenta o estudo das leis de propagação das velocidades de vibração resultantes do uso de explosivo em diferentes maciços. Foram efectuados estudos para três tipos de maciços diferentes, granito, quartzito e calcário. Efectuaram-se campanhas de monitorização e registo dos dados em cada uma das situações. Caracterizando e utilizando duas leis de propagação de velocidades no maciço, a de Johnson e Langefors, calculou-se as suas variáveis por método estatístico de regressões lineares múltiplas. Com a obtenção das variáveis fizeram-se estudos de previsão dos valores de vibração a obter utilizando a carga explosiva aplicada nos desmontes. Através dos valores de vibração obtidos em cada pega de fogo para cada tipo de maciço comparou-se quais das duas leis apresentam o valor de velocidade de vibração menor desviado do real. Conforme ficou verificado neste estudo, a equação de Langefors garante uma mais-valia da sua aplicação na previsão das velocidades de vibração pois joga favoravelmente a nível da segurança assim como apresenta um menor desvio face à equação de Johnson quando comparada com o valor real de vibração obtido. Com isto o método de utilização de regressões lineares múltiplas como cálculo dos efeitos vibratórios é extremamente vantajoso a nível de prevenção de danos e cálculo de velocidades de vibração inferiores ao imposto pela Norma.

Interactions between physical and psychosocial demands of work associated to low back pain

OBJECTIVE: To examine the interaction between physical and psychosocial demands of work associated to low back pain. METHODS: Cross-sectional study carried out in a stratified proportional random sample of 577 plastic industry workers in the metropolitan area of the city of Salvador, Northeast Brazil in 2002. An anonymous standard questionnaire was administered in the workplace by trained interviewers. Physical demands at work were self-rated on a 6-point numeric scale, with anchors at each end of the scale. Factor analysis was carried out on 11 physical demand variables to identify underlying factors. Psychosocial work demands were measured by demand, control and social support questions. Multivariate analysis was performed using the likelihood ratio test. RESULTS: The factor analysis identified two physical work demand factors: material handling (factor 1) and repetitiveness (factor 2). The multiple logistic regression analysis showed that factor 1 was positively associated with low back pain (OR=2.35, 95% CI 1.50;3.66). No interaction was found between physical and psychosocial work demands but both were independently associated to low back pain. CONCLUSIONS: The study found independent effects of physical and psychosocial work demands on low back pain prevalence and emphasizes the importance of physical demands especially of material handling involving trunk bending forward and trunk rotation regardless of age, gender, and body fitness.

Análise e melhoria de processo de pintura e vulcanização na Continental

A indústria automóvel é um dos setores mais exigentes do mercado global, por este motivo empresas como a Continental Mabor S.A, líderes de mercado, necessitam estar na linha da frente no que toca a programas de melhoria contínua e de uma gestão orientada para um crescimento rentável e sustentado. Nesta perspetiva, este estudo de dissertação tem como objetivo encontrar uma solução para a gestão de stock e FiFo (First in First out) de pneus em verde na supracitada empresa, situada em Lousado, Vila Nova de Famalicão. Este projeto de dissertação iniciou-se com uma análise e diagnóstico do processo produtivo do pneu, entre a Construção e a Vulcanização. Nesta análise, foi possível identificar vários problemas, sendo o mais crítico associado à logística interna de transporte do pneu “em curso”, de fabrico entre as fases do mesmo, Construção e Vulcanização. Devido a condicionantes estruturais e de organização, a logística interna de transporte entre estes dois sectores enfrenta estrangulamentos nos fluxos, a falta de espaço para acomodar o material em curso, problemas organizacionais de controlo e monitorização do processo produtivo, dificuldades de regulação do fluxo e localização dos carros de transporte dos pneus em verde. Face aos problemas detetados ao longo do estudo, foram analisadas várias soluções para a resolução ou minimização dos mesmos. Entre as soluções propostas salientam-se: o alargamento do sistema de transporte por tapetes rolantes GTC (Green Tire Conveying) a todos os módulos de construção. Esta solução diminui o fluxo de carros para a área da construção, descongestionando a zona próxima do sistema de carregamento automático GTAL (Green Tire Automatic Loading) na vulcanização. A implementação dum sistema Wi-Fi RFID, que permite identificar e localizar artigos em curso utilizando etiquetas inteligentes numa rede wireless, conseguindo melhorar a programação de produção e o respetivo sequenciamento. Sabendo também que a Continental se encontra numa fase de expansão, designada Projeto Route 17/20, as soluções propostas tomaram em consideração essa nova realidade futura. Assim, foram estudados e propostos novos layouts para esse atual processo. Nestes novos layouts, procurou-se uma reorganização dos processos de fabrico, bem como um redimensionamento dos espaços de parqueamento de carros de pneus verdes adequado aos volumes produtivos. De igual forma, adequou-se os espaços físicos à possível implementação de um sistema de FiFo de pneus em verde na planta fabril, quando concluída a expansão. Este trabalho de dissertação apresenta como vantagens diretas da sua implementação: gerar a menor perturbação no atual método de trabalho seguido na empresa; previsivelmente aumentar a eficiência do processo produtivo; potenciar o crescimento tecnológico programado pela empresa; e oferecer uma boa relação custo/benefício no investimento necessário. Como apreciação final, pode-se concluir que este estudo foi finalizado com sucesso, visto que as soluções propostas foram apreciadas positivamente pela Administração da Continental Mabor S.A. e estão correntemente a ser avaliadas pelo grupo.