995 resultados para Polyvinyl chloride industry


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This thesis considers optimization problems arising in printed circuit board assembly. Especially, the case in which the electronic components of a single circuit board are placed using a single placement machine is studied. Although there is a large number of different placement machines, the use of collect-and-place -type gantry machines is discussed because of their flexibility and increasing popularity in the industry. Instead of solving the entire control optimization problem of a collect-andplace machine with a single application, the problem is divided into multiple subproblems because of its hard combinatorial nature. This dividing technique is called hierarchical decomposition. All the subproblems of the one PCB - one machine -context are described, classified and reviewed. The derived subproblems are then either solved with exact methods or new heuristic algorithms are developed and applied. The exact methods include, for example, a greedy algorithm and a solution based on dynamic programming. Some of the proposed heuristics contain constructive parts while others utilize local search or are based on frequency calculations. For the heuristics, it is made sure with comprehensive experimental tests that they are applicable and feasible. A number of quality functions will be proposed for evaluation and applied to the subproblems. In the experimental tests, artificially generated data from Markov-models and data from real-world PCB production are used. The thesis consists of an introduction and of five publications where the developed and used solution methods are described in their full detail. For all the problems stated in this thesis, the methods proposed are efficient enough to be used in the PCB assembly production in practice and are readily applicable in the PCB manufacturing industry.

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Mercury is a xenobiotic metal that is a highly deleterious environmental pollutant. The biotransformation of mercury chloride (HgCl2) into methylmercury chloride (CH3HgCl) in aquatic environments is well-known and humans are exposed by consumption of contaminated fish, shellfish and algae. The objective of the present study was to determine the changes induced in vitro by two mercury compounds (HgCl2 and CH3HgCl) in cultured human lymphocytes. Short-term human leukocyte cultures from 10 healthy donors (5 females and 5 males) were set-up by adding drops of whole blood in complete medium. Cultures were separately and simultaneously treated with low doses (0.1 to 1000 µg/l) of HgCl2 and CH3HgCl and incubated at 37ºC for 48 h. Genotoxicity was assessed by chromosome aberrations and polyploid cells. Mitotic index was used as a measure of cytotoxicity. A significant increase (P < 0.05) in the relative frequency of chromosome aberrations was observed for all concentrations of CH3HgCl when compared to control, whether alone or in an evident sinergistic combination with HgCl2. The frequency of polyploid cells was also significantly increased (P < 0.05) when compared to control after exposure to all concentrations of CH3HgCl alone or in combination with HgCl2. CH3HgCl significantly decreased (P < 0.05) the mitotic index at 100 and 1000 µg/l alone, and at 1, 10, 100, and 1000 µg/l when combined with HgCl2, showing a synergistic cytotoxic effect. Our data showed that low concentrations of CH3HgCl might be cytotoxic/genotoxic. Such effects may indicate early cellular changes with possible biological consequences and should be considered in the preliminary evaluation of the risks of populations exposed in vivo to low doses of mercury.

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Finland, other Nordic countries and European Union aim to decarbonize their energy production by 2050. Decarbonization requires large scale implementation of non-emission energy sources, i.e. renewable energy and nuclear power. Stochastic renewable energy sources present a challenge to balance the supply and demand for energy. Energy storages, non-emissions fuels in mobility and industrial processes are required whenever electrification is not possible. Neo-Carbon project studies the decarbonizing the energy production and the role of synthetic gas in it. This thesis studies the industrial processes in steel production, oil refining, cement manufacturing and glass manufacturing, where natural gas is already used or fuel switch to SNG is possible. The technical potential for fuel switching is assessed, and economic potential is necessary after this. All studied processes have potential for fuel switching, but total decarbonization of steel production, oil refining requires implementation of other zero-emission technologies.

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To quantify the effects of methylmercury (MeHg) on amacrine and on ON-bipolar cells in the retina, experiments were performed in MeHg-exposed groups of adult trahiras (Hoplias malabaricus) at two dose levels (2 and 6 µg/g, ip). The retinas of test and control groups were processed by mouse anti-parvalbumin and rabbit anti-alphaprotein kinase C (alphaPKC) immunocytochemistry. Morphology and soma location in the inner nuclear layer were used to identify immunoreactive parvalbumin (PV-IR) and alphaPKC (alphaPKC-IR) in wholemount preparations. Cell density, topography and isodensity maps were estimated using confocal images. PV-IR was detected in amacrine cells in the inner nuclear layer and in displaced amacrine cells from the ganglion cell layer, and alphaPKC-IR was detected in ON-bipolar cells. The MeHg-treated group (6 µg/g) showed significant reduction of the ON-bipolar alphaPKC-IR cell density (mean density = 1306 ± 393 cells/mm²) compared to control (1886 ± 892 cells/mm²; P < 0.001). The mean densities found for amacrine PV-IR cells in MeHg-treated retinas were 1040 ± 56 cells/mm² (2 µg/g) and 845 ± 82 cells/mm² (6 µg/g), also lower than control (1312 ± 31 cells/mm²; P < 0.05), differently from the data observed in displaced PV-IR amacrine cells. These results show that MeHg changed the PV-IR amacrine cell density in a dose-dependent way, and reduced the density of alphaKC-IR bipolar cells at the dose of 6 µg/g. Further studies are needed to identify the physiological impact of these findings on visual function.

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The pulp and paper industry is currently facing broad structural changes due to global shifts in demand and supply. These changes have significant impacts on national economies worldwide. In this paper, we describe the recent trends in the pulp and recovered paper (RP) production, and estimate augmented gravity models of bilateral trade for chemical pulp and RP exports with panel data. According to our results, there is some variation in the effects of the traditional gravity-model variables between pulp grades and RP. The results imply also that, in comparison to export supply, import demand plays a larger role in determining the volume of exports. Finally, it is evident that Asia, particularly China, is the most important driver of chemical pulp and RP trade: China is hungry for fiber, and must import to satisfy its growing needs. Moreover, the speed of China’s growth in chemical pulp and RP imports has been driving the increased significance of planted forests in the exports of hardwood pulp (BHKP) as well.

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The present study was designed to evaluate the time course changes in peripheral markers of oxidative stress in a chronic HgCl2 intoxication model. Twenty male adult Wistar rats were treated subcutaneously daily for 30 days and divided into two groups of 10 animals each: Hg, which received HgCl2 (0.16 mg kg-1 day-1), and control, receiving the same volume of saline solution. Blood was collected at the first, second and fourth weeks of Hg administration to evaluate lipid peroxidation (LPO), total radical trapping antioxidant potential (TRAP), and superoxide dismutase (Cu,Zn-SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and catalase (CAT). HgCl2 administration induced a rise (by 26%) in LPO compared to control (143 ± 10 cps/mg hemoglobin) in the second week and no difference was found at the end of the treatment. At that time, GST and GPx were higher (14 and 24%, respectively) in the Hg group, and Cu,Zn-SOD was lower (54%) compared to control. At the end of the treatment, Cu,Zn-SOD and CAT were higher (43 and 10%, respectively) in the Hg group compared to control (4.6 ± 0.3 U/mg protein; 37 ± 0.9 pmol/mg protein, respectively). TRAP was lower (69%) in the first week compared to control (43.8 ± 1.9 mM Trolox). These data provide evidence that HgCl2 administration is accompanied by systemic oxidative damage in the initial phase of the process, which leads to adaptive changes in the antioxidant reserve, thus decreasing the oxidative injury at the end of 30 days of HgCl2 administration. These results suggest that a preventive treatment with antioxidants would help to avoid oxidative damage in subjects with chronic intoxication.

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Over the last 30 years, new technologies and globalization have radically changed the way in which marketing is conducted. However, whereas their effects on business in general have been widely discussed, the focus of the effects on marketing remains without clear recognition. Global research has been made to shed light onto the issue, but it has widely concentrated on the views of executives as well as the consumer markets. In addition, a research gap is existent in applying the concept of marketing change in a specific business-to-business (B2B) industry. Therefore, the main research question this study seeks to answer is: “How is contemporary marketing conducted in the high-technology industry?” In this research, the researcher considers the specific industry of high-technology. However, as the industry is comprised of differing markets, the focus will be given to one of the industry’s prime sectors – the information technology (IT) markets, where companies offer other firms products or services manufactured with advanced technology. The growing IT-market is considered of critical importance in the economies of technologically ready countries such as Finland, where this research is also conducted. Through multiple case studies the researcher aims to describe how the changes in technology, customer engagement and future trends have shaped the way in which successful high-tech marketing is conducted in today’s marketplace. Then, results derived from the empirical research are presented to the reader with links to existing literature. As a conclusion, a generalized framework is constructed to depict and ideal marketer-customer relationship, with emphasis on dynamic, two-way communication and its supporting elements of customer analytics, change adaptation, strategic customer communication and organizational support. From a managerial point of view, the research may provide beneficial information as contemporary marketing can yield profitable outcomes if managed correctly. As a new way to grasp competitive advantage, strategic marketing is much more data-driven and customer-focused than ever before. The study can also prove to be relevant for the academic communities, while its results may act as inspiring for new focus on the education trends of future marketers. This study was limited to the internal activities done at the high-tech industry, leaving out the considerations for co-marketing, marketing via business partners or marketing at other B2B-industries.

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Työn aiheena oli tutkia vaahdon soveltuvuutta ohuiden päällystyskerrosten applikointiin paperin tai kartongin pinnalle. Paperia ja kartonkia päällystetään teollisessa mittakaavassa eri menetelmillä, mutta niille kaikille yhteistä on päällystyspastan laimentaminen vedellä ennen applikointia ja laimennusveden haihduttaminen applikoinnin jälkeen päällysteen asettamiseksi. Laimennus on tärkeää pastan komponenttien tasaisen levittämisen vuoksi, mutta veden haihduttaminen kuluttaa valtavasti energiaa. Tekstiiliteollisuudessa on saavutettu merkittäviä säästöjä kuivausenergiassa korvaamalla laajalti vedellä laimentaminen vaahdottamisella. Diplomityön kirjallisessa osassa käytiin läpi vaahdon kemiallisia ja fysikaalisia ominaisuuksia sekä selvitettiin mitä kemikaaleja ja laitteita vaahdotukseen käytetään. Lisäksi luotiin katsaus vaahtoprosessien käyttöön tekstiiliteollisuudessa ja muilla aloilla. Kokeellinen osa koostui esikokeista, joissa selvitettiin pastan koostumuksen vaikutuksia vaahtoamiseen, ja pilot-mittakaavan koeajoista, joissa esikokeiden tuloksia hyödynnettiin. Esikokeissa huomiota kiinnitettiin varsinkin eri polyvinyylialkoholien (PVA) seosten erinomaiseen vaahtoavuuteen. Pilot-koeajoissa vaahtopäällystys vaikutti lupaavalta menetelmältä, joskaan täysin tyydyttävää päällystystulosta ei saavutettu. Suurimpana ongelmana esiintyi ilman pääseminen pohjapaperin ja päällysteen väliin ja siitä seuraava huono päällystejälki. Toisen ongelmakokonaisuuden muodostivat päällysteeseen jäävät reiät. Vaahtopäällystys vaikuttaa lupaavalta tekniikalta ohuiden päällystekerrosten applikointiin, mutta pastareseptejä tulee optimoida ja ratkaista päällysteen alle pääsevän ilman ongelma.

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The main objective of this Master’s thesis is to develop a cost allocation model for a leading food industry company in Finland. The goal is to develop an allocation method for fixed overhead expenses produced in a specific production unit and create a plausible tracking system for product costs. The second objective is to construct an allocation model and modify the created model to be suited for other units as well. Costs, activities, drivers and appropriate allocation methods are studied. This thesis is started with literature review of existing theory of ABC, inspecting cost information and then conducting interviews with officials to get a general view of the requirements for the model to be constructed. The familiarization of the company started with becoming acquainted with the existing cost accounting methods. The main proposals for a new allocation model were revealed through interviews, which were utilized in setting targets for developing the new allocation method. As a result of this thesis, an Excel-based model is created based on the theoretical and empiric data. The new system is able to handle overhead costs in more detail improving the cost awareness, transparency in cost allocations and enhancing products’ cost structure. The improved cost awareness is received by selecting the best possible cost drivers for this situation. Also the capacity changes are taken into consideration, such as usage of practical or normal capacity instead of theoretical is suggested to apply. Also some recommendations for further development are made about capacity handling and cost collection.

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This study attempted to provide a project based on the already tested and successful results of foreign business which can help to contain the final price of innovation on desired levels. The research will attempt to dig out most of available information related to aforementioned definitions and thus completing theoretical background. Next author will explain used methodology and the process of evidence collection. After that the study will show the analysis of collected data in order to obtain results which are going to be compared with stated objectives in the final part. The conclusion of the research and proposed possibilities for additional work will be given in the last part. For this study author has chosen the qualitative model because it performs very well for analysis of small scale of data. The case study method was used because it gave author an opportunity to make an in-depth analysis of the collected information about particular organization so it became possible to analyze system's details in comparison. The results have been early considered valid and applicable to other studies. As the result thesis has proposed undertakings which reflect researches aimed on solving problems with provision of services and development of communications. In addition thesis has proposed formulation of database of postal service for Russian Post when (by request) customer possess an account where he or she can access postal services via PC or info table in postal office and order delivery of postal products which will be given private identification code. Project's payoff period has been calculated as well.

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The purpose of this research was to define content marketing and to discover how content marketing performance can be measured especially on YouTube. Further, the aim was to find out what companies are doing to measure content marketing and what kind of challenges they face in the process. In addition, preferences concerning the measurement were examined. The empirical part was conducted through multiple-case study and cross-case analysis methods. The qualitative data was collected from four large companies in Finnish food and drink industry through semi-structured phone interviews. As a result of this research, a new definition for content marketing was derived. It is suggested that return on objective, or in this case, brand awareness and engagement are used as the main metrics of content marketing performance on YouTube. The major challenge is the nature of the industry, as companies cannot connect the outcome directly to sales.

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The goal of this research – which is to critically analyze current theories and methods of intangible assets evaluation and potentially develop and test new methodology based on the practical example(s) in the IT industry. Having this goal in mind the main research questions in this paper will be: What are advantages and disadvantages of the current practices of measurement intellectual capital or valuation of intangible assets? How to properly measure intellectual capital in IT? Resulting method exhibits a new unique approach to the IC measurement and potentially even larger field of application. Despite the fact that in this particular research, I focused my attention on IT (Software and Internet services cluster – to be exact), the logic behind the method is applicable within any industry since the method is designed to be fully compliant with measurement theory and thus can be properly scaled for any application. Building a new method is a difficult and iterative process: in the current iteration the method stands out as rather a theoretical concept rather than a business tool, however even current concept totally fulfills its purpose as a benchmarking tool for measuring intellectual capital in IT industry.

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Vacuolar H+-ATPase is a large multi-subunit protein that mediates ATP-driven vectorial H+ transport across the membranes. It is widely distributed and present in virtually all eukaryotic cells in intracellular membranes or in the plasma membrane of specialized cells. In subcellular organelles, ATPase is responsible for the acidification of the vesicular interior, which requires an intraorganellar acidic pH to maintain optimal enzyme activity. Control of vacuolar H+-ATPase depends on the potential difference across the membrane in which the proton ATPase is inserted. Since the transport performed by H+-ATPase is electrogenic, translocation of H+-ions across the membranes by the pump creates a lumen-positive voltage in the absence of a neutralizing current, generating an electrochemical potential gradient that limits the activity of H+-ATPase. In many intracellular organelles and cell plasma membranes, this potential difference established by the ATPase gradient is normally dissipated by a parallel and passive Cl- movement, which provides an electric shunt compensating for the positive charge transferred by the pump. The underlying mechanisms for the differences in the requirement for chloride by different tissues have not yet been adequately identified, and there is still some controversy as to the molecular identity of the associated Cl--conducting proteins. Several candidates have been identified: the ClC family members, which may or may not mediate nCl-/H+ exchange, and the cystic fibrosis transmembrane conductance regulator. In this review, we discuss some tissues where the association between H+-ATPase and chloride channels has been demonstrated and plays a relevant physiologic role.

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Currents mediated by calcium-activated chloride channels (CaCCs), observed for the first time in Xenopus oocytes, have been recorded in many cells and tissues ranging from different types of neurons to epithelial and muscle cells. CaCCs play a role in the regulation of excitability in neurons including sensory receptors. In addition, they are crucial mediators of chloride movements in epithelial cells where their activity regulates electrolyte and fluid transport. The roles of CaCCs, particularly in epithelia, are briefly reviewed with emphasis on their function in secretory epithelia. The recent identification by three independent groups, using different strategies, of TMEM16A as the molecular counterpart of the CaCC is discussed. TMEM16A is part of a family that has 10 other members in mice. The discovery of the potential TMEM16 anion channel activity opens the way for the molecular investigation of the role of these anion channels in specific cells and in organ physiology and pathophysiology. The identification of TMEM16A protein as a CaCC chloride channel molecule represents a great triumph of scientific perseverance and ingenuity. The varied approaches used by the three independent research groups also augur well for the solidity of the discovery.