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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

Characterisation of SAPPI SAICCOR pulp mill's effluent.

Moodley, Brenda. January 2001 (has links)
SAPPI SAJCCOR, whose factory is situated south of Durban, South Africa, is one of the few paper and pulp mills that uses the acid sulphite process with calcium and magnesium bases to produce a high-grade cellulose pulp. Four streams of effluent, namely, the calcium - spent liquor stream, the magnesium condensate stream and two streams from the bleaching effluent are produced during this sulphite pulping process and they contain a variety of organic compounds extracted from the wood. Characterisation of the effluent was based on isolation using column chromatography and identification using NMR techniques. A range of constituents, such as lignans and lignin - type precursors, a trilerpenoid and fatty acids were isolated and identified. X-ray diffraction was used to identify an inorganic residue obtained from the calcium - spent liquor stream and gas chromatography/mass spectrometry was used to identify a wax residue. which builds up in the process. In addition to this, the carbohydrate content of the four streams of effluent was detennined using UV/visiblc spectroscopy. / Thesis (M.Sc.)-University of Natal, Durban, 2001.
352

Análise do padrão de expressão de MMP-2, -9 e -8 em tecido humano pulpar normal e inflamado / Analysis of the expression perfile of MMP-2, -9 and -8 in normal and inflamed human pulp tissue

Mattos, Maria Cecília Ribeiro de 19 October 2009 (has links)
As metaloproteinases da matriz (MMPs) foram relacionadas a diversas doenças inflamatórias como artrite e também ao câncer. O presente trabalho tem por objetivo estabelecer o papel da MMP-2, MMP-9 e MMP-8 no processo de inflamação pulpar. Foram adotadas as seguintes hipóteses nulas: (1) o padrão de expressão das MMP-2, MMP-9 e MMP-8 não sofre alteração nos diferentes estágios da polpa humana: normal, reversível, transição, irreversível ou necrose; (2) não há diferença de expressão das MMP-2, -9 e MMP-8, considerando-se um mesmo estágio de inflamação tecidual pulpar. Os métodos utilizados foram: (I) Obtenção dos espécimes, que foram divididos em grupos de acordo com critérios adotados de semiologia subjetiva e objetiva. Obtiveram-se os seguintes grupos: GI (Controle) dentes hígidos (n=7); GII (Pulpite Reversível n=4); GIII (Pulpite Transição n=4); GIV (Pulpite Irreversível/Necrose n=8). Logo após exodontia, os dentes obtidos foram cortados ligeiramente abaixo da junção amelodentinária e fixados em formol a 10% por 48h. Foram lavados em água corrente (24h) para então serem processados histologicamente. Foram obtidas secções de 4m, aderidas em lâminas silanizadas e submetidas à imunomarcação (Técnica da Peroxidase), utilizando os anticorpos anti MMP-2, MMP-9 e MMP-8 humanos. A presença de imunomarcação foi realizada através da análise semi-quantitativa por escores, sendo que a quantificação de marcação por corte seguiu o seguinte escore: 0= ausente; 1= leve; 2= moderada; 3= intensa. Realizou-se teste estatístico não paramétrico Kruskal-Wallis, p<0,05. As comparações intergrupos revelaram, para CO: (1)MMP-2 - GI=GII=GIII, GIII=GIV, GI>GIV (p<0,01) e GII>GIV (p<0,05); (2)MMP-9 GI=GII=GIV, GII=GIII e GIII>GI (p<0,01); (3)MMP-8 GI=GII=GIII=GIV. Na região central da polpa, obteve-se: (1)MMP-2 GI=GII=GIII, GIII=GIV, GI>GIV (p<0,001) e GII>GIV (p<0,01); (2)MMP-9 GI=GII=GIII, GIII=GIV, GIV>GI (p<0,001) e GIV>GII (p<0,01); (3)MMP-8 GI=GII, GIII=GIV, GIII>GI (p<0,05), GIV>GI (p<0,01), GIII>GII (p<0,05) e GIV>GII (p<0,05). Quanto às comparações intragrupos, na CO mostraram: (1)GI - MMP-2>MMP9 (p<0,001), MMP-2=MMP-8 e MMP-9=MMP-8; (2)GII MMP-2>MMP-9 (p<0,01); MMP-2=MMP-8 e MMP-9=MMP-8; (3)GIII e GIV MMP-2=MMP-9=MMP-8. Para a região mais central da polpa: (1)GI e GII MMP-2=MMP-9=MMP-8; (2)GIII MMP9>MMP-2 (p<0,05), MMP- 2=MMP-8 e MMP-9=MMP-8; (3)GIV MMP-9>MMP-2 (p<0,01), MMP-2=MMP-8 e MMP-9=MMP-8. Sendo assim, as duas hipóstese nulas foram rejeitadas. Conclui-se ainda que MMP-2, MMP-9 e MMP-8 atuam no processo de inflamação pulpar de maneira distinta na CO e polpa central; MMP-2 é mais expressa em polpa sadia; a maior expressão de MMP-9 relaciona-se à presença de inflamação pulpar; em polpas inflamadas, a expressão de MMP- 8 é maior quando comparadas a polpas normal, embora tal enzima seja também levemente expressada em tecido pulpar normal. / The matrix metalloproteinases (MMPs) have been related to various inflammatory diseases, such as arthritis, as well as to cancer. The aim of the present study was to establish the role of MMP-2, MMP-9 and MMP-8 in the process of dental pulp inflammation. The following null hypotheses were adopted: (1) the pattern of MMP-2, MMP-9 and MMP-8 expression does not undergo alteration in the following different stages of human pulp: normal, reversible, transition, irreversible or necrosis; (2) there is no difference in the expression of MMP-2, -9 and MMP-8, when considering the same stage of pulp tissue inflammation. The methods used were: (I) Obtainment of specimens, which were divided into groups according to the subjective and objective criteria of semiology adopted. The following groups were obtained: GI (Control) healthy teeth (n=7); GII (Reversible Pulpitis n=4); GIII (Transition Pulpitis n=4); GIV (Irreversible Pulpitis/Necrosis n=8). Soon after extraction the teeth obtained were cut slightly below the amelodentinal junction and fixed in 10% formol for 48h. They were washed under running water (24h) and were histologically processed afterwards. Sections of 4m were obtained, adhered to silanized slides, and submitted to immunomarking (Peroxidase Technique), using human anti MMP-2, MMP-9 and MMP- 8 antibodies. The presence of immunomarking was determined through semi-quantitative analysis by scores, and marking by cut was quantified using the following score: 0= absent; 1= slight; 2= moderate; 3= intense. The Kruskal-Wallis non-parametric statistical test was performed, p<0.05. Intergroup comparisons revealed the following: for CO: (1)MMP-2 - GI=GII=GIII, GIII=GIV, GI>GIV (p<0.01) and GII>GIV (p<0.05); (2)MMP-9 GI=GII=GIV, GII=GIII and GIII>GI (p<0,01); (3)MMP-8 GI=GII=GIII=GIV. In the central region of the pulp, the following results were obtained: (1)MMP-2 GI=GII=GIII, GIII=GIV, GI>GIV (p<0.001) and GII>GIV (p<0.01); (2)MMP-9 GI=GII=GIII, GIII=GIV, GIV>GI (p<0.001) and GIV>GII (p<0.01); (3)MMP-8 GI=GII, GIII=GIV, GIII>GI (p<0.05), GIV>GI (p<0.01), GIII>GII (p<0.05) and GIV>GII (p<0.05). With regard to intragroup comparisons, in CO the following were shown: (1)GI - MMP-2>MMP9 (p<0.001), MMP-2=MMP-8 and MMP-9=MMP-8; (2)GII MMP-2>MMP-9 (p<0.01); MMP-2=MMP-8 and MMP-9=MMP-8; (3)GIII and GIV MMP- 2=MMP-9=MMP-8. For the most central region of the pulp: (1)GI and GII MMP-2=MMP- 9=MMP-8; (2)GIII MMP9>MMP-2 (p<0.05), MMP-2=MMP-8 and MMP-9=MMP-8; (3)GIV MMP-9>MMP-2 (p<0.01), MMP-2=MMP-8 and MMP-9=MMP-8. Therefore, the two null hypotheses were rejected. Moreover, it was concluded that MMP-2, MMP-9 and MMP-8 act in the process of pulp inflammation in a distinct manner in CO and central pulp; more MMP-2 is expressed in healthy pulp; the highest expression of MMP-9 is related to the presence of pulp inflammation; in inflamed pulp, the expression of MMP-8 is higher when compared with that of normal pulp, although this enzyme is also slightly expressed in normal pulp tissue.
353

Avaliação do processo Compact CookingTM com o uso de aditivos para a polpação kraft de eucalipto / Evaluation of Compact CookingTM process with additives for kraft pulping of Eucalyptus

Trebbi, Laura Sabbatini 08 October 2015 (has links)
O Brasil ocupa a quarta colocação no ranking mundial de produção de celulose, sendo que quase 90% da matéria prima é madeira de fibra curta, especificamente do gênero Eucalyptus. O processo de produção de celulose mais utilizado pela grande maioria das indústrias do mundo todo é o químico e, entre os processos químicos modificados está o Compact CookingTM, que é reconhecido por gerar polpas de alta resistência físico-mecânica e boa branqueabilidade. Aditivos de cozimento são amplamente utilizados no processo de fabricação da celulose, pois permitem melhores rendimento e qualidade do produto obtido. O presente trabalho teve como objetivo avaliar a eficiência de quatro aditivos na polpação kraft de eucalipto através do processo Compact CookingTM, buscando melhorias no rendimento do processo e ganho na qualidade da polpa produzida. Os cozimentos foram conduzidos em digestor laboratorial da marca TSI com bomba dosadora acoplada. O tempo total de cozimento foi de 457 minutos, com temperatura máxima de 165&ordm; C, resultando em um perfil de cozimento com fator H de 2100. Os aditivos testados foram antraquinona, aditivo 2, aditivo 3 e xilenossulfonato de sódio. A antraquinona e os aditivos 2 e 3 foram aplicados em carga de 0,05% (base madeira) e o xilenossulfonato de sódio foi testado em três cargas: 2, 4 e 8 kg.ton-1 (base madeira). Os resultados obtidos mostraram que o uso do xilenossulfonato de sódio como aditivo na polpação kraft, levando em consideração as especificidades desta pesquisa, não gerou benefícios ao processo e, por isso, o mesmo não foi utilizado nos passos seguintes deste estudo. A antraquinona possibilitou a redução de um ponto percentual de álcali ativo aplicado e consequente ganho de rendimento de 1,6% em relação ao tratamento sem aditivo. Tanto para o aditivo 2 quanto para o aditivo 3 foi possível alcançar o mesmo grau de deslignificação (número kappa 17 &#177; 05) com redução de cinco pontos percentuais de álcali ativo aplicado em relação ao tratamento testemunha, gerando ganho de 2,3 e 2,4% em rendimento. A viscosidade das polpas com a antraquinona e com os aditivos 2 e 3 também aumentou de maneira significativa se comparada à polpa sem aditivo, sendo os melhores resultados alcançados nos tratamentos com os aditivos 2 e 3; tais aditivos também possibilitaram a maior queda nos valores de consumo específico de madeira e teor de sólidos gerados. Quando testadas em relação a propriedades físico-mecânicas, as polpas produzidas com a utilização dos aditivos 2 e 3 apresentaram as melhores performances, com benefícios na tração, estouro e resistência à passagem de ar. É possível concluir que, para a madeira e processo de polpação utilizados neste trabalho, os aditivos 2 e 3 se mostraram bastante superiores à antraquinona. Assim, fica a sugestão para que mais trabalhos e estudos sejam desenvolvidos com estes produtos, buscando o melhor conhecimento dos mesmos e a comprovação de tal desempenho para a produção de polpa celulósica. / Brazil occupies the fourth place in global pulp production ranking and almost 90% of the raw material used for the national production is hardwood, specifically Eucalyptus. The most used process for pulp production by industries worldwide is the chemical pulping and among the modified chemical processes, there is Compact CookingTM. This one is recognized for producing pulps with high resistance and good bleachability. Additives are widely used in the pulp production process, as they allow better yield and quality of the final product. This study aimed at evaluating the effectiveness of four additives in Eucalyptus kraft pulping, by using Compact CookingTM process, seeking for improvements in process yield and in the pulp quality. The pulp simulation was conducted in laboratory digester that had a pump coupled in it. The total cooking time was 457 minutes, with maximum temperature of 165&ordm; C, resulting in a cooking profile with H factor value equal to 2100. The additives used were anthraquinone, additive 2, additive 3 and sodium xylenesulphonate. The anthraquinone and additives 2 and 3 were applied in 0.05% wood base and sodium xylenesulphonate was tested in three loads: 2, 4 and 8 kg.ton-1 (wood base). The results showed that the use of sodium xylenesulphonate as an additive in kraft pulping, considering the specific case of this research, didn\'t generated benefits in the process and, because of this, it was eliminated from the next steps of this research project. Anthraquinone allowed the reduction of 1% in alkali applied and consequent 1.6% yield gain compared to treatment without additive. For both additives 2 and 3, it was possible to achieve the same delignification level (kappa number 17 &#177; 0.5) by reducing 5% of alkali applied in comparison to the control treatment and this allowed yield gain of 2.3 and 2.4%. The viscosity of the pulp produced by using anthraquinone and additives 2 and 3 increased significantly compared to the pulp without the chemicals, and better results were achieved for treatments with additives 2 and 3; with these additives the pulping process reached the lowest values on wood specific consumption and generated solids. When tested for the physical and mechanical properties, the pulps produced with additives 2 and 3 showed better performances, with benefits in tensile index, burst index and resistance to air flow. Therefore, it was possible to conclude that, for the wood and the pulping process used in this study, additives 2 and 3 showed better results than anthraquinone. The suggestion is that more studies must be developed with these two chemical products, with the objective of reaffirming such good performance in the pulp production.
354

Bioactive Hydrogel Scaffold for Guided Dental Pulp Regeneration

Prateepchinda, Sagaw January 2015 (has links)
Over 15 million root canal treatments (RCT) are performed yearly in the United States to treat deep caries and dental pulp infection. This procedure however, removes both the diseased and healthy pulp, leading to tooth devitalization. Furthermore, RCTs are associated with a high incidence of re-infection and dentin fracture, reduced sensitivity and eventual tooth loss. Thus there is an unmet clinical need for alternative endodontic therapies that can preserve tooth vitality and ensure long term dental health. The strategy of vital endodontic therapy explored in this thesis centers on the design of a bioactive scaffold that guides host cell homing while providing antibiotic release, in effect harnessing the intrinsic repair potential of the native pulp while simultaneously eliminating residual bacteria that can cause recurrent infection. Specifically, a bioactive polyethylene glycol fibrinogen (PEG-fibrinogen) hydrogel is optimized to support host cell infiltration, maintain dental pulp cell phenotype, and enable pulp regeneration. Ciprofloxacin, a clinically relevant antibiotic for RCT, is incorporated into PEG-fibrinogen to prevent infection. The scaffold and culturing parameters optimized in vitro using either explant or a tooth slice model includes fibrinogen, poly(ethylene glycol) diacrylate (PEGDA) and photoinitiator concentration, as well as cell source and density. In addition, dose-dependent antibiotic effects on both anaerobic bacteria isolated from deep caries and healthy pulp cells are evaluated. The collective findings of this thesis demonstrate that a cell-instructive hydrogel comprised of a fibrinogen backbone and cross-linked with difunctional poly(ethylene glycol) side chains supports pulp cell viability, phenotypic morphology, and host cell migration. Furthermore, increasing pulp cell density promotes cell biosynthesis and a higher fibrinogen concentration is found to enhance collagen deposition. Photoinitiator and PEGDA concentrations have been optimized to enhance hydrogel mechanical properties and gel degradation, while supporting pulp cell phenotype. An optimal antibiotic dosage in the hydrogel has been identified that significantly reduces bacteria count from infected dental pulp without harmful side effects on dental pulp cell phenotype and host cell migration. In summary, this thesis focuses on the design of a bioactive hydrogel-based scaffold with antibiotic release that can induce dental pulp regeneration without the addition of cells and stimuli such as growth factors and minimize post-therapy infection. The innovative scaffold design strategy presented here lays the foundation for the development of vital endodontic therapy that harnesses pulp self-repair and sustains long-term tooth function.
355

Avaliação de coprodutos da alimentação humana como fonte alternativa de fibras para cães: parâmetros digestivos e metabólicos / Evaluation of co-products human food as an alternative source of fiber for dogs: digestive and metabolic

Folconi, Livia Rosa 08 September 2015 (has links)
As fibras de coprodutos da produção de sucos, néctar e refrescos possuem propriedade funcional, envolvidas no metabolismo fermentativo da microbiota intestinal, com benefícios potenciais á saúde dos cães. O emprego de coprodutos alimentícios humano no desenvolvimento de petfood apresentam vantagens de sustentabilidade ambiental e econômica. O estudo objetivou avaliar os efeitos de dietas extrusadas com inclusão fixa de 3,5% de celulose (CEL), farelo de arroz desengordurado (FAR), polpa cítrica (PCT) e polpa de maçã (PMA) como fontes de fibras dietéticas solúveis e insolúveis nos coeficientes de digestibilidade aparente dos nutrientes (CDA), respostas glicêmicas e insulinêmicas pós- prandiais e produtos de fermentação nas fezes. O experimento foi realizado com oito cães adultos hígidos, peso médio de 15,0&#177;5,0kg e idade média de 5,0&#177;2,0 anos, distribuídos em delineamento em dois quadrados latino 4x4. Após 7 dias de adaptação dos animais, realizou-se coleta de fezes nos dias 5&ordm;-10&ordm; para determinar CDA das dietas, entre 12&ordm; ao 15&ordm; dia mensurados pH, produção de ácido lático, AGCC, AGCR e aminas biogênicas (AB) das fezes, seguidos pelas coletas de sangue para determinação das respostas glicêmicas e insulinêmicas pós-prandiais nos 16&ordm; e 17&ordm; dias. Não houve efeito dos tratamentos (p>0,05) no CDA da matéria orgânica (MO) e matéria mineral (MM), entretanto, houve efeito (p<0,05) nos CDAs da proteína bruta (PB), extrato etéreo em hidrólise ácida (EEHA), fibra bruta (FB) e extrativos não nitrogenados (ENN). O tratamento CEL apresentou maior CDA da PB e menor CDA da FB. O CDA dos ENN não apresentou diferença entre PMA e CEL. Em relação às características fecais, observou-se maior MS no tratamento CEL. Os tratamentos PCT e PMA resultaram em pH das fezes inferior aos tratamentos CEL e FAR e sem diferenças entre si. O tratamento PMA resultou em maior escore fecal e menor produção de fezes por cão/dia na MS, contrário ao tratamento PCT, que resultou em maior produção de fezes cão/dia, na MO e MS. Não foi observado efeito dos tratamentos (p>0,05) nas concentrações fecais de lactato e AB. O tratamento PCT resultou em maior produção de acetato, propionato e butirato que o tratamento CEL (p<0,05), enquanto que os tratamentos PCT e PMA resultaram em produção de AGCR mais elevados que FAR (p<0,05). Não houve efeito das fontes de fibras estudadas nas respostas glicêmicas e insulinêmicas pós- prandiais (p<0,05). / The coproducts of fiber production of juice, nectar and soft drinks have functional property, involved in fermentative metabolism of intestinal microbiota, with potential benefits to health of dogs. The use of co-products of human food industry in the development of petfood has advantages of environmental and economic sustainability. The study aimed to evaluate the effects of extruded diets with fixed inclusion of 3.5% cellulose (CEL), defatted rice bran (FAR), citrus pulp (PCT) and apple pulp (PMA) as sources of soluble and insoluble dietary fibers on dog total tract apparent digestibility coefficient of nutrients (ADC), glycemic and insulin postprandial responses, and fermentation products in the stool. The experiment was carried out on eight healthy adult dogs of mean weight of 15.0 &#177; 5,0kg and a mean age of 5,0 &#177; 2,0 years allotted to a 4 x 4 Latin square two. After 7 days of adjustment of the animals to the diets, there was feces collection in the days 5th-10th to determine CDA diets, between 12th to 15th measured pH, lactic acid production, AGCC, AGCR and biogenic amines (BA) of the stool, followed by blood samples for determination of glucose and insulin responses postprandial in 16 and 17 days. There was no effect of the treatments (p> 0.05) in the ADC of organic matter (OM) and mineral matter (MM), however, was no effect (p <0.05) in CDAs of dry matter (DM), crude protein (CP), ether extract acid hydrolysis (EEHA), crude fiber (CF) and nitrogen free extract (NFE). The CEL treatment obtained higher ADC of CP and lower ADC of FB. The ACD of NFE no difference between PMA and CEL. For fecal characteristics, there was a higher DM in CEL treatment. PCT treatments and PMA resulted in fecal pH lower than the CEL and FAR treatments and without differences. The PMA treatment resulted in greater fecal score and lower production of faeces per dog / day in DM, contrary to the PCT treatment, which resulted in increased production of dog feces / day in MO and DM. There was no effect of the treatments (p> 0.05) in fecal concentrations of lactate and AB. The PCT treatment resulted in increased production of acetate, propionate and butyrate that CEL treatment (p <0.05), while the PCT and PMA treatments resulted in higher production AGCR that FAR (p <0.05). There was no effect (p <0.05) of sources of fiber studied for glycemic and insulin curves, area under the curve (AUC) of glucose and insulin, increasing blood glucose and insulin.
356

Topochemical and performance aspects of fiber oxidation

Barzyk, David 07 1900 (has links)
No description available.
357

Effects of ethanol media on chlorine dioxide and extraction stages for kraft pulp bleaching

Brogdon, Brian N. 08 1900 (has links)
No description available.
358

An Isotopic Study of Fiber-Water Interactions

Walsh, Frances Luella 04 August 2006 (has links)
A new technique for measuring the water content of fiber is presented. Tritiated water is added to a pulp/water suspension whereupon the tritium partitions between the bulk water and the pulp. Through this technique a fiber:water partition coefficient is developed, Kpw. This thesis will cover the development of the Kpw procedure and three different case studies. The first study involves comparing Kpw to traditional methods of fiber water content. The procedure provides a value of ten percent for the tightly bound water content of unrefined hardwood or softwood kraft fiber, either bleached or unbleached. If this water is assumed to cover the fiber surface as a monolayer, then an estimate of the wet surface area of fiber can be obtained. This estimate compares well to independent measurements of surface area. Kpw has also been found to be valuable in furthering the understanding of refining. Based on the study, it is proposed that refining occurs in three discrete stages. First, refining removes the primary cell wall and S1 layer while beginning to swell the S2 layer. Next, internal delamination occurs within the S2 layer. Finally, fiber destruction occurs at high refining levels. By using Kpw, the three stages of refining are clearly recognized. Lastly, Kpw is used to study the effect of hornification on bleached softwood kraft fiber. The recycling effects at three refining levels were characterized by Kpw and followed closely the findings of the refining study. At low and high refining levels, the impact of recycling was minimal according to Kpw results, but at 400 mL csf the impact of recycling was much more pronounced. This could be attributed to the closing of internal delaminations within the fiber.
359

THE INDUCTION OF DENTIN BRIDGE-LIKE STRUCTURES BY CONSTRUCTS OF SUBCULTURED DENTAL PULP-DERIVED CELLS AND POROUS HA/TCP IN PORCINE TEETH

ANDO, YUSUKE, HONDA, MASAKI J., OHSHIMA, HAYATO, TONOMURA, AKIKO, OHARA, TAKAYUKI, ITAYA, TOSHIMITSU, KAGAMI, HIDEAKI, UEDA, MINORU 02 1900 (has links)
No description available.
360

Žemsiurbės „Watermaster Classic III“ darbo efektyvumo įvertinimas / Dredger's "Wattermaster Classic III" work efficiency rating

Valančius, Lukas 21 June 2013 (has links)
Magistriniame darbe pateikta literatūros analizė, tyrimų tikslas ir uždaviniai, tyrimo metodika, tyrimų rezultatai ir jų analizė, išvados. Nustatyta, kad Lietuvoje ežerams valyti naudojamų žemsiurbių pagrindinis trūkumas yra siurbiama skysta pulpa ir mažas jos transportavimo atstumas. Tyrimų tikslas yra įvertinti dažniausiai naudojamos žemsiurbės „Watermaster Classic III“ tinkamumą ežerų valymui Lietuvoje. Tiesioginiais matavimais, trijuose pjūviuose, buvo nustatyti vandens gyliai išvalytose Masčio ežero ir Pakruojo tvenkinio dalyse. Suspenduotų dalelių kiekiui vandenyje nustatyti, iš Masčio ežero buvo paimti buteliu – batometru vandens mėginiai (iš karto baigus siurbimą), tūriniu būdu išmatuotas žemsiurbės našumas. Išmatavus vandens gylius, buvo atlikta aprašomoji stastika, kurios metu buvo pasitelkta „Hydrotech” bei “Microsoft Excel”programinė įranga. Autorius savo jėgomis atliko visus tyrimus. Nustatyta, kad valant Masčio ežero dalį žemsiurbe „Watermaster Classic III“, valymo tolygumas atskiruose pjūviuose siekė 8,1–10,2 %, žymiai prastesnis nei palyginimui Pakruojo tvenkinio dalyje, valant žemsiurbe „3350MK“ (tolygumas sieke 2,9–3,2 %). Esant darbinei konsistencijai 3,7 %, žemsiurbės „Watermaster Classic III“ našumas už 433 m siekė 76 %. Suspenduotų dalelių kiekis tik pirmą dieną prie žemsiurbės buvo žymiai didesnis už foninį lygį, už 10–20 m foninio lygio, o vėliau visur tapo foninio lygmens. Žemsiurbės „Watermaster Classic III“ dienos darbo laiko panaudojimo... [toliau žr. visą tekstą] / This Master's thesis presents the analysis of the literature, the aim and tasks of researches, the methodology, results, analysis and conclusions of the research. It was found that the main drawbacks of dredges which are cleaning lakes in Lithuania are the liquid pulp pumped and its low transportation distance. The aim of this research is to evaluate the most commonly used dredges’ “Watermaster Classic III” suitability for cleaning lakes in Lithuania. The water depths in three sections cleaned in Mastis and Pakruojis lakes were determined by direct measurements, to identify the quantity of suspended particles in the water in Mastis lake (immediately after dredging) water samples were taken with bottle – bathometer and the efficiency of dredge was evaluated using volumetric method. After measuring water death the descriptive statistic was carried out using “Hydrotech“ and “Microsoft Excel” software. All researches were made by author itself. It was found that dredging part of the lake Mastis with “Watermaster Classic III” cleaning uniformity in separate sections was 8.1 to 10.2% while cleaning the part of lake Pakruojis with the dredge „3350MK“ uniformity was significantly lower (2,9 to 3,2 %). In 3.7 % operating consistency “Watermaster Classic III” performance at 433 m was 76 %. The quantity of suspended particles only the first day around the dredge was significantly higher than the background level – 10-20 m above it but later everywhere became equal to background level... [to full text]

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