947 resultados para Heavy Process Manufacturing


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The aim of this paper is to analyse the effects of human capital, advanced manufacturing technologies (AMT), and new work organizational practices on firm productivity, while taking into account the synergies existing between them. This study expands current knowledge in this area in two ways. First, in contrast with previous works, we focus on AMT and not ICT (information and communication technologies). Second, we use a unique employer-employee data set for small firms in a particular area of southern Europe (Catalonia, Spain). Using a small firm data set, allows us to analyse the particular case of small and medium enterprises, since we cannot assume they have the same characteristics as large firms. The results provide evidence in favor of the complementarity hypothesis between human capital, advanced manufacturing technologies, and new work organization practices, although we show that the complementarity effects depend on what type of work organization practices are used by a firm. For small and medium Catalan firms, the only set of work organization practices that improve the benefits of human capital and technology investment are those practices which are more quality oriented, such as quality circles, problem-solving groups or total quality management.

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Objectives: Polychlorinated biphenyls (PCBs) are considered probable human carcinogens by the International Agency for Research on Cancer and one congener, PCB126, has been rated as a known human carcinogen. A period-specific job exposure matrix (JEM) was developed for former PCB-exposed capacitor manufacturing workers (n=12,605) (1938-1977). Methods: A detailed exposure assessment for this plant was based on a number of exposure determinants (proximity, degree of contact with PCBs, temperature, ventilation, process control, job mobility). The intensity and frequency of PCB exposures by job for both inhalation and dermal exposures, and additional chemical exposures were reviewed. The JEM was developed in nine steps: (1) all unique jobs (n=1,684) were assessed using (2) defined PCB exposure determinants; (3) the exposure determinants were used to develop exposure profiles; (4) similar exposure profiles were combined into categories having similar PCB exposures; (5) qualitative intensity (high-medium-low-baseline) and frequency (continuous-intermittent) ratings were developed, and (6) used to qualitatively rate inhalation and dermal exposure separately for each category; (7) quantitative intensity ratings based on available air concentrations were developed for inhalation and dermal exposures based on equal importance of both routes of exposure; (8) adjustments were made for overall exposure, and (9) for each category the product of intensity and frequency was calculated, and exposure in the earlier era was weighted. Results: A period-specific JEM modified for two eras of stable PCB exposure conditions. Conclusions: These exposure estimates, derived from a systematic and rigorous use of the exposure determinant data, lead to cumulative PCB exposure-response relationships in the epidemiological cancer mortality and incidence studies of this cohort. [Authors]

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We establish the validity of subsampling confidence intervals for themean of a dependent series with heavy-tailed marginal distributions.Using point process theory, we study both linear and nonlinear GARCH-liketime series models. We propose a data-dependent method for the optimalblock size selection and investigate its performance by means of asimulation study.

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Accomplish high quality of final products in pharmaceutical industry is a challenge that requires the control and supervision of all the manufacturing steps. This request created the necessity of developing fast and accurate analytical methods. Near infrared spectroscopy together with chemometrics, fulfill this growing demand. The high speed providing relevant information and the versatility of its application to different types of samples lead these combined techniques as one of the most appropriated. This study is focused on the development of a calibration model able to determine amounts of API from industrial granulates using NIR, chemometrics and process spectra methodology.

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The objective of the current study was to determine the predictive value of high normal gamma-glutamyltransferase (GGT) level as an indication of heavy drinking in young men. In a sample of 577 men attending a one-day army recruitment process mandatory for all Swiss men at age 19 years, GGT level was evaluated as the dependent variable for each of eight dichotomous classifications of individuals on the basis of meeting cut-off criteria for five indexes of alcohol use, two indexes of alcohol-related problems, and one index of body mass. The sensitivity, specificity, and predictive values of GGT level in identifying subjects as either heavy drinkers or being overweight were determined. Compared with findings for their counterparts, GGT level was higher in subjects reporting consumption of more than 14 drinks per week (20.5 +/- 7.81 vs. 18.9 +/- 7.60, P <.05), in those reporting being drunk at least once during the past 30 days (20.3 +/- 7.80 vs. 18.3 +/- 7.43, P <.001), and in individuals with body mass indexes >or=25 kg/m(2) (25.8 +/- 10.84 vs. 18.3 +/- 6.59, P <.001). At a GGT level cut-off of 20 U/l, the sensitivity, specificity, and positive and negative predictive values of either being a heavy drinker or overweight were 48.2%, 70.2%, 67.7%, and 51.2%, respectively. Exclusion of subjects with body mass indexes of >or=25 kg/m(2) revealed similar results. High normal GGT level in young men is indicative of heavy alcohol use or being overweight; when present, subjects should be screened further for potential concomitant drinking problems.

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Production flow analysis (PFA) is a well-established methodology used for transforming traditional functional layout into product-oriented layout. The method uses part routings to find natural clusters of workstations forming production cells able to complete parts and components swiftly with simplified material flow. Once implemented, the scheduling system is based on period batch control aiming to establish fixed planning, production and delivery cycles for the whole production unit. PFA is traditionally applied to job-shops with functional layouts, and after reorganization within groups lead times reduce, quality improves and motivation among personnel improves. Several papers have documented this, yet no research has studied its application to service operations management. This paper aims to show that PFA can well be applied not only to job-shop and assembly operations, but also to back-office and service processes with real cases. The cases clearly show that PFA reduces non-value adding operations, introduces flow by evening out bottlenecks and diminishes process variability, all of which contribute to efficient operations management.

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This paper investigates relationships between cooperation, R&D, innovation and productivity in Spanish firms. It uses a large sample of firm-level micro-data and applies an extended structural model that aims to explain the effects of cooperation on R&D investment, of R&D investment on output innovation, and of innovation on firms’ productivity levels. It also analyses the determinants of R&D cooperation. Firms’ technology level is taken into account in order to analyse the differences between high-tech and low-tech firms, both in the industrial and service sectors. The database used was the Technological Innovation Panel (PITEC) for the period 2004-2010. Empirical results show that firms which cooperate in innovative activities are more likely to invest in R&D in subsequent years. As expected, R&D investment has a positive impact on the probability of generating an innovation, in terms of both product and process, for manufacturing firms. Finally, innovation output has a positive impact on firms’ productivity, being greater in process innovations.

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This paper investigates relationships between cooperation, R&D, innovation and productivity in Spanish firms. It uses a large sample of firm-level micro-data and applies an extended structural model that aims to explain the effects of cooperation on R&D investment, of R&D investment on output innovation, and of innovation on firms’ productivity levels. It also analyses the determinants of R&D cooperation. Firms’ technology level is taken into account in order to analyse the differences between high-tech and low-tech firms, both in the industrial and service sectors. The database used was the Technological Innovation Panel (PITEC) for the period 2004-2010. Empirical results show that firms which cooperate in innovative activities are more likely to invest in R&D in subsequent years. As expected, R&D investment has a positive impact on the probability of generating an innovation, in terms of both product and process, for manufacturing firms. Finally, innovation output has a positive impact on firms’ productivity, being greater in process innovations. Keywords: innovation sources; productivity; R&D Cooperation

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We developed a semiquantitative job exposure matrix (JEM) for workers exposed to polychlorinated biphenyls (PCBs) at a capacitor manufacturing plant from 1946 to 1977. In a recently updated mortality study, mortality of prostate and stomach cancer increased with increasing levels of cumulative exposure estimated with this JEM (trend p values = 0.003 and 0.04, respectively). Capacitor manufacturing began with winding bales of foil and paper film, which were placed in a metal capacitor box (pre-assembly), and placed in a vacuum chamber for flood-filling (impregnation) with dielectric fluid (PCBs). Capacitors dripping with PCB residues were then transported to sealing stations where ports were soldered shut before degreasing, leak testing, and painting. Using a systematic approach, all 509 unique jobs identified in the work histories were rated by predetermined process- and plant-specific exposure determinants; then categorized based on the jobs' similarities (combination of exposure determinants) into 35 job exposure categories. The job exposure categories were ranked followed by a qualitative PCB exposure rating (baseline, low, medium, and high) for inhalation and dermal intensity. Category differences in other chemical exposures (solvents, etc.) prevented further combining of categories. The mean of all available PCB concentrations (1975 and 1977) for jobs within each intensity rating was regarded as a representative value for that intensity level. Inhalation (in microgram per cubic milligram) and dermal (unitless) exposures were regarded as equally important. Intensity was frequency adjusted for jobs with continuous or intermittent PCB exposures. Era-modifying factors were applied to the earlier time periods (1946-1974) because exposures were considered to have been greater than in later eras (1975-1977). Such interpolations, extrapolations, and modifying factors may introduce non-differential misclassification; however, we do believe our rigorous method minimized misclassification, as shown by the significant exposure-response trends in the epidemiologic analysis.

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Heavy-ion reactions and other collective dynamical processes are frequently described by different theoretical approaches for the different stages of the process, like initial equilibration stage, intermediate locally equilibrated fluid dynamical stage, and final freeze-out stage. For the last stage, the best known is the Cooper-Frye description used to generate the phase space distribution of emitted, noninteracting particles from a fluid dynamical expansion or explosion, assuming a final ideal gas distribution, or (less frequently) an out-of-equilibrium distribution. In this work we do not want to replace the Cooper-Frye description, but rather clarify the ways of using it and how to choose the parameters of the distribution and, eventually, how to choose the form of the phase space distribution used in the Cooper-Frye formula. Moreover, the Cooper-Frye formula is used in connection with the freeze-out problem, while the discussion of transition between different stages of the collision is applicable to other transitions also. More recently, hadronization and molecular dynamics models have been matched to the end of a fluid dynamical stage to describe hadronization and freeze-out. The stages of the model description can be matched to each other on space-time hypersurfaces (just like through the frequently used freeze-out hypersurface). This work presents a generalized description of how to match the stages of the description of a reaction to each other, extending the methodology used at freeze-out, in simple covariant form which is easily applicable in its simplest version for most applications.

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Manufacturing of glass from tin mining tailings in Bolivia Tailings from mining activities in Bolivia represent an environmental problem. In the vicinity of the tin mines of Llallagua,Potosí department, there are large dumps and tailings. We present a study of the use of these wastes as raw materials for the manufacture of glass. This procedure aims to contribute to environmental remediation of mining areas through the vitrification, a process which offers an alternative for stabilization of hazardous waste. In addition, the marketing of the obtained product would provide an additional income to the mining areas. For this study three samples of mining waste, with grain size between sand and silt, were used. The chemical composition of these raw materials, determined by X-ray fluorescence, is granitic, with high contents of heavy metals. On the basis of its composition, glass were made from silica glass by adding CaCO3 and Na2CO3. The thermal cycle has been determined from TDA. Tg values of glass range from 626º to 709 °C. Leaching tests of the obtained glasses confirm their capacity to retain heavy metals.

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Työn tavoitteena oli perehtyä innovaatiojohtamisen ja järjestelmän soveltamiseen prosessiteollisuuden toimintaympäristöön. Kirjallisuuslähteitä apuna käyttäen perehdyttiin liiketoimintaympäristön innovaatiojohtamiselle asettamiin vaatimuksiin ja erilaisiin innovaatiojärjestelmiin. Olennaisena osana innovaatiojohtamiseen liittyy sidosryhmien tarpeiden ja niiden tarjoamien resurssien huomioiminen toiminnassa. Myöskin tuotekehityksen menetelmät ja työkalut ovat omalta osaltaan merkittävässä asemassa toiminnan tehokkuutta arvioitaessa. Innovaatiojärjestelmä tulee sopeuttaa yrityksen toimintoihin ja sen erityispiirteet huomioonottaen siten, että toiminnan johtaminen prosessina tuo yritykselle ja sen sidosryhmille lisäarvoa. Innovaatiojärjestelmän luominen yritykselle on ainayksilöllinen prosessi ja siihen ei ole olemassa yleispätevää menetelmää, joka voitaisiin ottaa käyttöön sellaisenaan. Yritys, jonka liiketoiminta keskittyy kuitupohjaisten pakkausmateriaalien valmistamiseen, joutuu täyttämään toiminnassaan materiaalintoimittajien, omien tuotantoprosessiensa ja asiakkaiden sekä jopa loppukäyttäjien uusille tuotteille luomat odotukset. Innovaatiojohtamista sävyttää toiminnan tulosten suuri epävarmuus ja sen vaativien aineellisten ja henkisten resurssien mittavuus. Innovaatiotoiminnan johtaminen prosessina, käyttäen hyväksi järjestelmämallia, tavoittelee systemaattista ja asetettujen kriteerien täyttämää lähestymistapaa tuotekehityksen ja uusien liiketoimintainnovaatioiden alueella. Kehitetyn mallin tulee palvella monimutkaista liiketoimintaympäristöä, jokatoisaalta perustuu tehokkaaseen massatuotantoon ja toisaalta pyrkii erilaistumaan palvelemalla sekä huomioimalla asiakkaidensa tuotteille asettamat vaatimukset.

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The aim of this research study was to find out guidelines for outsourcing of logistics processes. The study was outlined to spare parts and `business-to-business' (B2B) markets in metal industry. This study can be applied as a manual for outsourcing especially warehousing and transportation activities. The study also touches other important areas of spare part logistics like manufacturing, customer service, procurement, quality control, reverse and recycling logistics, logistics technologies and valueadded services. The method of study consisted of three areas. Firstly exchanging views with logistics experts in participating companies, and secondly compiling material based on author's practical experience in logistics business with several international and domestic logistics service providers and vendors. Thirdlythe study includes also references to literature material. Due to the fact thatthe outsourcing of logistics functions can be handled widely and from differentpoint of views, in this study it is concentrated mainly on giving general levelguidelines for defining logistics strategy, hints both for tendering process and implementation project, and not forgetting the aftercare of business partnership.

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It is generally accepted that between 70 and 80% of manufacturing costs can be attributed to design. Nevertheless, it is difficult for the designer to estimate manufacturing costs accurately, especially when alternative constructions are compared at the conceptual design phase, because of the lack of cost information and appropriate tools. In general, previous reports concerning optimisation of a welded structure have used the mass of the product as the basis for the cost comparison. However, it can easily be shown using a simple example that the use of product mass as the sole manufacturing cost estimator is unsatisfactory. This study describes a method of formulating welding time models for cost calculation, and presents the results of the models for particular sections, based on typical costs in Finland. This was achieved by collecting information concerning welded products from different companies. The data included 71 different welded assemblies taken from the mechanical engineering and construction industries. The welded assemblies contained in total 1 589 welded parts, 4 257 separate welds, and a total welded length of 3 188 metres. The data were modelled for statistical calculations, and models of welding time were derived by using linear regression analysis. Themodels were tested by using appropriate statistical methods, and were found to be accurate. General welding time models have been developed, valid for welding in Finland, as well as specific, more accurate models for particular companies. The models are presented in such a form that they can be used easily by a designer, enabling the cost calculation to be automated.

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Työn tavoitteena oli arvioida ja selvittää toimittajasuhteeseen vaikuttavia tekijöitä JOT Automation Group Oyj.n ja sen alihankkijoiden välisessä yhteistyössä ja muodostaa yrityksen kilpailukykyä parantava toimittaja-arviointiprosessi. Työssä keskityttiin tarkastelemaan yleisillä materiaali- ja komponenttimarkkinoilla toimivia toimittajia elektroniikkateollisuuden tuotantojärjestelmien valmistuksessa. Ensin tutustuttiin toimittajasuhdetta ja sen arviointia käsitelleeseen kirjallisuuteen. Teorian tueksi tehtiin haastatteluja ja kartoitettiin ensisijaisia tarpeita ja tavoitteita arviointiprosessille. Valmis prosessi testattiin käytännössä kahden eri case-esimerkin avulla. Prosessista muodostui kahteen eri työkaluun jakautunut kokonaisuus, joista auditointi arvioi toimittajan kyvykkyyttä vastatta sille asetettuihin vaatimuksiin. Toimittajan suorituskyvyn mittaaminen puolestaan testaa ja vertaa jatkuvasti toiminnan todellista tasoa auditoinnissa saatuihin tuloksiin. Työ sisältää selvityksen ja ohjeistuksen toimittaja-arviointiprosessin käytöstä. Prosessin käyttö alentaa toimittajaan kohdistuvaa materiaalien saatavuuteen ja hankintaan liittyviä riskejä. Esimerkeistä saadut kokemukset osoittivat, että prosessin avulla päästään pureutumaan tärkeisiin ydinalueisiin ja kehittämään niitä sekä toimittajalle, että ostajayritykselle edullisella tavalla. Toimittaja-arviointiprosessista kehittyy toimintatapa yrityksen ja sen toimittajan välisen suhteen ylläpitämiseksi.