992 resultados para paper mill
Resumo:
Olive mill wastewater, hereafter noted as OMWW was tested for its composition in phenolic compounds according to geographical areas of olive tree, i.e. the plain and the mountainous areas of Tadla-Azilal region (central Morocco). Biophenols extraction with ethyl acetate was efficient and the phenolic extract from the mountainous areas had the highest concentration of total phenols' content. Fourier-Transform-Middle Infrared (FT-MIR) spectroscopy of the extracts revealed vibration bands corresponding to acid, alcohol and ketone functions. Additionally, HPLC-ESI-MS analyses showed that phenolic alcohols, phenolic acids, flavonoids, secoiridoids and derivatives and lignans represent the most abundant phenolic compounds. Nüzhenide, naringenin and long chain polymeric substances were also detected. Mountainous areas also presented the most effective DPPH scavenging potential compared to plain areas; IC50 values were 11.7 ± 5.6 µg/ml and 30.7 ± 4.4 µg/ml, respectively. OMWW was confirmed as a rich source of natural phenolic antioxidant agents.
Resumo:
The aim of this thesis is to define effects of lignin separation process on Pulp mill chemical balance especially on sodium/sulphur-balance. The objective is to develop a simulation model with WinGEMS Process Simulator and use that model to simulate the chemical balances and process changes. The literature part explains what lignin is and how kraft pulp is produced. It also introduces to the methods that can be used to extract lignin from black liquor stream and how those methods affect the pulping process. In experimental part seven different cases are simulated with the created simulation model. The simulations are based on selected reference mill that produces 500 000 tons of bleached air-dried (90 %) pulp per year. The simulations include the chemical balance calculation and the estimated production increase. Based on the simulations the heat load of the recovery boiler can be reduced and the pulp production increased when lignin is extracted. The simulations showed that decreasing the waste acid stream intake from the chlorine dioxide plant is an effective method to control the sulphidity level when about 10 % of lignin is extracted. With higher lignin removal rates the in-mill sulphuric acid production has been discovered to be a better alternative to the sulphidity control.
Resumo:
O artigo argumenta que é possível se falar em uma 'tradição' no campo de filosofia social e econômica unindo as obras de J.S. Mill e Alfred Marshall e J.M. Keynes. Essa 'tradição' pode ser caracterizada pelas seguintes concepções: (a) pela rejeição moral aos valores aquisitivos do capitalismo; (b) pela visão de que o sistema capitalista seria incapaz de resolver de forma espontânea as questões das desigualdades de renda e riqueza e da pobreza; (c) pela ideia de que, por uma questão de garantia de liberdade e da diversidade, além de por questões de eficiência econômica, dever-se-ia deixar a iniciativa individual agir livremente nas esferas em que é capaz de engendrar bons resultados, mas que o Estado deveria intervir, quando essa falha, atuando em benefício da coletividade; (d) pela crença de que seria possível melhorar significativamente esse sistema por meio de mudanças pontuais e graduais.
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O presente artigo apresenta argumentos em defesa da hipótese de que nomes próprios gerais são impossíveis no contexto da filosofia geral de Stuart Mill. Minha tese é contrária à posição de John Skorupski sobre esta questão. Ofereço dois argumentos que representam, respectivamente, duas diferentes perspectivas: pragmático e sistemático. No primeiro, analiso o problema dos nomes próprios gerais no contexto da linguagem natural. No segundo, discuto o problema no contexto interno do Sistema de Lógica de Mill.
Resumo:
Valssi on valssauslaitteiston keskeinen komponentti. Valssauksessa aihiota muokataan kuljettamalla sitä kahden valssin muodostaman raon välistä. Valssit altistuvat valssausprosessissa korkealle lämpötilalle ja pintapaineelle. Valsseille asetettavat vaatimukset tiukkenevat tuottavuuden vaatimusten kiristyessä. Valssit, yhtenä valssauslaitteiston komponenteista, muodostavat suuren osan valssauksen kustannuksista, joten valssien käyttöiän pidentämisen avulla voidaan parantaa valssauksen tuottavuutta ja kustannustehokkuutta. Tässä tutkimuksessa tarkasteltiin valssien käytettävyyttä ja kunnossapitoa, sillä näitä asioita kehittämällä on mahdollista saavuttaa valsseille pidempi kestoikä. Tutkimus toteutettiin kirjallisuusselvityksenä, jota täydennettiin valssausta tekevien yritysten haastatteluilla. Tavoitteena oli kerätä saatavissa oleva kirjallinen ja hiljainen tieto yksiin kansiin ja tutkia mahdollisia syy-seuraussuhteita valssien käytettävyyteen vaikuttavien ilmiöiden sekä valssien kulumisen ja vaurioitumisen välillä. Tutkimuksessa havaittiin, että vauriotyypit ovat riippuvaisia valssausprosessista, jolla tarkoitetaan, että kuuma- ja kylmävalssauksessa esiintyy erilaisia vauriotyyppejä. Kuuma- ja kylmävalssauksessa myös valssien kulumiseen vaikuttavat erilaiset ilmiöt. Valssien kulumista ja vaurioita on mahdollista ehkäistä erilaisilla pintakäsittely- ja pinnoitusmenetelmillä. Valssien kunnossapidon toteutusta tutkittaessa havaittiin, että kuluneiden valssien vaihto kunnostettuihin pyritään suorittamaan mahdollisimman nopeasti ja tätä varten on saatavilla kyseiseen tarkoitukseen kehitettyjä laitteistoja. Kuluneet valssit sorvataan ja hiotaan, jotta niiden pinnasta saadaan tasainen ja saavutetaan haluttu halkaisija. Tämän jälkeen pinnoitusmenetelmiä on mahdollista suorittaa uudelleen. Kunnossapitotoimenpiteet tehdään joko yrityksen omalla korjaamolla tai alihankintana toisen yrityksen tiloissa.
Resumo:
This master thesis presents a study on the requisite cooling of an activated sludge process in paper and pulp industry. The energy consumption of paper and pulp industry and it’s wastewater treatment plant in particular is relatively high. It is therefore useful to understand the wastewater treatment process of such industries. The activated sludge process is a biological mechanism which degrades carbonaceous compounds that are present in waste. The modified activated sludge model constructed here aims to imitate the bio-kinetics of an activated sludge process. However, due to the complicated non-linear behavior of the biological process, modelling this system is laborious and intriguing. We attempt to find a system solution first using steady-state modelling of Activated Sludge Model number 1 (ASM1), approached by Euler’s method and an ordinary differential equation solver. Furthermore, an enthalpy study of paper and pulp industry’s vital pollutants was carried out and applied to revise the temperature shift over a period of time to formulate the operation of cooling water. This finding will lead to a forecast of the plant process execution in a cost-effective manner and management of effluent efficiency. The final stage of the thesis was achieved by optimizing the steady state of ASM1.
Resumo:
Tilintarkastuksen sääntely on lisääntynyt merkittävästi 2000-luvulla. Samalla kilpailu on kiristynyt, tilintarkastuspalkkiot alentuneet ja raportointiaikataulut tiukentuneet. Näistä tekijöistä johtuen tilintarkastuksen tehostamiselle on tarvetta. Tämän tutkielman tavoitteena on selvittää ja tutkia, miten tilintarkastusprosessia voidaan tehostaa sekä arvioida eri tehostamiskeinojen käyttöarvoa punnitsemalla niiden mahdollisuuksia ja haasteita. Tutkielman empiirinen osa on toteutettu laadullisena tutkimuksena. Aineisto on kerätty haastattelemalla suomalaisia tilintarkastajia ja analyysimenetelmänä on käytetty teemoittelua. Empiirisessä osassa tutkitaan, miltä teoriasta löydettyjen tehostamiskeinojen käyttömahdollisuudet näyttävät käytännössä ja selvitetään, millä muilla keinoilla tilintarkastusprosessia voidaan tehostaa. Tutkimuksen perusteella tilintarkastuksen suunnitteluvaihetta voidaan tehostaa tilintarkastajien erikoistumisen, dokumentoinnin standardoinnin, sähköisen materiaalin tehokkaamman hyödyntämisen ja palvelukeskusten hyödyntämisen avulla. Toteutusvaihetta voidaan tehostaa näiden lisäksi big data -menetelmillä ja kontrollien tarkastuksella.
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Serving the Niagara and surrounding areas for over 120 years, Walker Industries has made its impact not only commercially, but also culturally. Beginning in 1875 with the erection of a stone sawing mill on a property John Walker purchased from the Welland Canal Loan Company. One of the first projects Walker cut stone for was the Merritton Town Hall. In 1882 the business expanded to include Walkers children, changing the name to Walker & Sons. Eventually in 1887 the two eldest sons took control of the business operation and their partnership changed the company’s name to Walker Brothers, the same year the company began operating its first quarry. The quarry was conveniently located alongside the 3rd Welland canal, offering easy access to Toronto and Hamilton. It was also close to the railway system which allowed immediate access to Thorold and Niagara Falls and later access to parts of Ontario and Quebec. The quarry supplied stone to build numerous halls and armouries across Ontario. A use was also found for the ‘waste products’ of cutting the limestone. Leftover stone chips were sent to paper mills, where stone was needed as part of the sulphite pulp process for making paper. Beginning to supply the Ontario Paper Company with stone in 1913, meant not only long, hard, work, but also more profit for the company. Before mechanization, most of the loading and unloading of the stone was done by hand, taking 19 man-hours to load an 18 yard railway car. Mechanization followed in 1947 when the plant became fully mechanized making the work easier and increasing production rates. In 1957 the company moved from its original location and opened the St. Catharines Crushed Stone Plant.
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Survey map of the land for the Mill Scibes Grand River Dam. Created by The Welland Canal Company. Included is a drawing of the land. Noteable features include; Sulphur Creek, post, bridge, Grand River, lot divisions, inside face of embankment. Surveyor notes are seen in pencil on the map.
Resumo:
This issue of Pleasant Hours: a paper for young folk contains an article titled "The Story of Queenston Heights".