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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.
1

The Effects of the Soil Conditioner, Superbio, Upon the Cellulose Decomposing Bacteria and the Crop Yield of a Soil

Gunn, Bruce Alan 08 1900 (has links)
The purpose of this investigation was to determine if a commercial soil conditioner, Superbio, can improve crop yield, and if the "advertised" soil improvement might be due to an increase in the activity and numbers of aerobic cellulose decomposing bacteria following treatment.
2

The effect of pre-plant incorporation with sawdust, sawdust mulch, and nitrogen fertilizer rate on soil properties and nitrogen uptake and growth of 'Elliott' highbush blueberry /

White, Linda D. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 57-59). Also available on the World Wide Web.
3

Torkat bioavfall som jordförbättringsmedel / Dried Biowaste as a Soil Conditioner

Blad, Sofia January 2007 (has links)
<p>The main project Dry preservation of source-separated organic household wastes involves a new technique for treatment of biowaste through drying. Investigations are going on to determine how the dried biowaste best can be used to close the natural circular flow of nutrients. The objective of this degree project is to determine if the dried biowaste can be used as a soil conditioner. By restoring the nutrients in the material to the ground, the natural circular flow is closed. A declaration of contents, including the nutrient levels, C/N ratio, pH and the electrical conductivity of the dried biowaste, was constructed and a germination test was done to make sure that the material did not inhibit sprouting. Further on a method was developed to study the decomposition process, and in particular the nitrogen mineralization of the dried biowaste. This method was then used practically.</p><p>The results of this degree project indicate that the decomposition capacity of the dried biowaste is very good. The germination test showed that the material in a diluted form (up to 50 % dried biowaste) did not inhibit sprouting. The examination of the nitrogen mineralization showed a fast liberalisation of nutrients available to plants, with only a shorter period of nitrogen immobilization. Together these results imply that the dried material could function well as a soil conditioner.</p> / <p>Projektet Torrkonservering av matavfall från hushåll innefattar en helt ny teknik för behandling av bioavfall genom torkning. Undersökningar pågår angående hur det torkade bioavfallet bäst kan användas för att sluta det naturliga kretsloppet. Examensarbetets huvudsyfte var, som ett led i dessa undersökningar, att utreda om det torkade bioavfallet kan användas som ett jordförbättringsmedel. Genom att tillföra bioavfallet till jord så återförs näringen i materialet till marken och kretsloppet sluts. En varudeklaration, med materialets näringshalter, C/N-kvot, pH och elektrisk konduktivitet, togs fram och ett groningstest utfördes för att kontrollera att bioavfallet inte var groningshämmande. Vidare utvecklades en metod för att studera det torkade bioavfallets nedbrytningsegenskaper i form av dess kvävemineralisering. Denna metod användes därefter praktiskt.</p><p>Resultatet av detta examensarbete tyder på att torkat bioavfall har mycket goda nedbrytningsegenskaper. Groningsförsöket visade att materialet i utspädd form (upp till 50 % torkat bioavfall) inte är groningshämmande, och mineraliseringsförsöket visade på en snabb frigörelse av växttillgängligt kväve, och en immobiliseringsperiod på ett par veckor. Tillsammans indikerar dessa resultat att det torkade materialet kan fungera väl som ett jordförbättringsmedel.</p>
4

Torkat bioavfall som jordförbättringsmedel / Dried Biowaste as a Soil Conditioner

Blad, Sofia January 2007 (has links)
The main project Dry preservation of source-separated organic household wastes involves a new technique for treatment of biowaste through drying. Investigations are going on to determine how the dried biowaste best can be used to close the natural circular flow of nutrients. The objective of this degree project is to determine if the dried biowaste can be used as a soil conditioner. By restoring the nutrients in the material to the ground, the natural circular flow is closed. A declaration of contents, including the nutrient levels, C/N ratio, pH and the electrical conductivity of the dried biowaste, was constructed and a germination test was done to make sure that the material did not inhibit sprouting. Further on a method was developed to study the decomposition process, and in particular the nitrogen mineralization of the dried biowaste. This method was then used practically. The results of this degree project indicate that the decomposition capacity of the dried biowaste is very good. The germination test showed that the material in a diluted form (up to 50 % dried biowaste) did not inhibit sprouting. The examination of the nitrogen mineralization showed a fast liberalisation of nutrients available to plants, with only a shorter period of nitrogen immobilization. Together these results imply that the dried material could function well as a soil conditioner. / Projektet Torrkonservering av matavfall från hushåll innefattar en helt ny teknik för behandling av bioavfall genom torkning. Undersökningar pågår angående hur det torkade bioavfallet bäst kan användas för att sluta det naturliga kretsloppet. Examensarbetets huvudsyfte var, som ett led i dessa undersökningar, att utreda om det torkade bioavfallet kan användas som ett jordförbättringsmedel. Genom att tillföra bioavfallet till jord så återförs näringen i materialet till marken och kretsloppet sluts. En varudeklaration, med materialets näringshalter, C/N-kvot, pH och elektrisk konduktivitet, togs fram och ett groningstest utfördes för att kontrollera att bioavfallet inte var groningshämmande. Vidare utvecklades en metod för att studera det torkade bioavfallets nedbrytningsegenskaper i form av dess kvävemineralisering. Denna metod användes därefter praktiskt. Resultatet av detta examensarbete tyder på att torkat bioavfall har mycket goda nedbrytningsegenskaper. Groningsförsöket visade att materialet i utspädd form (upp till 50 % torkat bioavfall) inte är groningshämmande, och mineraliseringsförsöket visade på en snabb frigörelse av växttillgängligt kväve, och en immobiliseringsperiod på ett par veckor. Tillsammans indikerar dessa resultat att det torkade materialet kan fungera väl som ett jordförbättringsmedel.
5

Evaluation of clean chip residual as an alternative substrate for container-grown plants

Boyer, Cheryl ReNee', Gilliam, Charles Homer, Fain, Glenn Bradley, January 2008 (has links) (PDF)
Thesis (Ph. D.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 173-188).
6

Disposal of a primary papermill sludge on sandy cropland soil

Huettl, Peter Joseph Vincent, January 1982 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
7

Use of woody debris as an amendment for reclamation after oil sands mining

Brown, Robyn Leigh. January 2010 (has links)
Thesis (M.Sc.)--University of Alberta, 2010. / Title from PDF file main screen (viewed on July 9, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Land Reclamation and Remediation, Department of Renewable Resources, University of Alberta. Includes bibliographical references.
8

Síntese, caracterização e aplicação de hidrogéis nanoestruturados contendo nanoargila para melhorar a germinação e qualidade de muda de hortaliça / Synthesis, characterization and application of nanostructured hydrogels containing nanoclay to improve germination and seedling quality of vegetable

Yonezawa, Uilian Gabaldi [UNESP] 04 March 2016 (has links)
Submitted by UILIAN GABALDI YONEZAWA null (uilian_yonezawa@yahoo.com.br) on 2016-05-16T21:16:30Z No. of bitstreams: 1 dissertação Final.pdf: 3612402 bytes, checksum: b582b0fd2450b9deae8e2a4e625add5a (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-05-17T18:33:33Z (GMT) No. of bitstreams: 1 yonezawa_ug_me_ilha.pdf: 3612402 bytes, checksum: b582b0fd2450b9deae8e2a4e625add5a (MD5) / Made available in DSpace on 2016-05-17T18:33:33Z (GMT). No. of bitstreams: 1 yonezawa_ug_me_ilha.pdf: 3612402 bytes, checksum: b582b0fd2450b9deae8e2a4e625add5a (MD5) Previous issue date: 2016-03-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os hidrogéis são polímeros hidrorretentores reticulados, que são capazes de reter e absorver grande quantidade de água. A combinação de polissacarídeos e nanoargila na matriz polimérica otimiza o desenvolvimento de materiais biodegradáveis e nanoestruturados que podem ser utilizados na agricultura. Nesta dissertação foram preparados e caracterizados hidrogéis nanoestruturados biodegradáveis, afim de aplicá-lo como um acelerador no crescimento de mudas de hortaliça. Os hidrogéis foram preparados fixando as concentrações de acrilamida (AAm) em 6% m/v e carboximetilcelulose (CMC) em 1% m/v, e incorporando diferentes concentrações de nanoargila cloisita-Na+. Diferentes quantidades de hidrogéis foram incorporadas ao substrato e investigado a sua eficiência no cultivo de alface. Foram analisadas as propriedades hidrofílicas e cinéticas em água destilada e em soluções salinas. Os hidrogéis demonstraram excelentes resultados de intumescimento. A incorporação de nanoargila na matriz do polímero aumentou a velocidade de absorção de água (indicada pelo aumento da constante cinética k) quando intumescido em água destilada. A formação das redes poliméricas foi confirmada pela análise de espectroscopia no infravermelho com transformada de Fourier (FTIR). A difração do raios-x (DRX) e a espectroscopia de energia dispersiva de Raios-X (EDX) permitiu avaliar a conformação das plaquetas de nanoargila e os elementos químicos presente nos nanocompósitos, respectivamente. A microscopia eletrônica de varredura (MEV) demonstrou uma morfologia de estruturas porosas, com formas bem definidas e tamanhos de poros heterogêneos. A análise térmica evidenciou uma estabilidade térmica abaixo de 200 ºC para todas as amostras analisadas. A aplicação do hidrogel como condicionador de solo demonstrou ser eficiente no cultivo de alface, se aplicado na dose ideal. A presença de nanoargila na matriz polimérica melhorou a germinação, o desenvolvimento e a qualidade das mudas testadas. Os resultados demonstram que os nanocompósitos são produtos promissores em meio de cultura que precisam de liberação controlada e de condicionadores de solo. / Hydrogels are water-retainer crosslinked polymers which are able to retain and absorb large quantities of water. The combination of polysaccharides and nanoclay in the polymeric matrix enhanced the development of nanostructured and biodegradable materials and it can be used in agriculture. In this work, nanostructured biodegradable hydrogels was prepared in order to improve germination and seedling quality of lettuce cultivation. The hydrogels were prepared by fixing the concentrations of acrylamide (AAm) in 6% w/v carboxymethylcellulose (CMC) in 1% w/v, containing different nanoclay Cloisite-Na+ concentrations. Different amounts of hydrogel were incorporated to the substrate and investigated their efficiency in lettuce cultivation. Hydrophilic and kinetic properties were investigated in distilled water and in saline solutions. The hydrogels showed excellent swelling degree results. Also, the incorporation of nanoclay in the polymer matrix increased the water absorption speed (indicated by an increase in kinetic constant k) when swollen in distilled water. The formation of polymer networks was confirmed by Fourier transform infrared spectroscopy (FTIR) analysis. The x-ray diffraction (XRD) and energy dispersive spectroscopy X-ray (EDX) corfimed the conformation of the nanoclay platelets and chemical elements present in the nanocomposite, respectively. The scanning electron microscopy (SEM) showed porous structures morphology with well-defined shapes, but with heterogeneity in the size. Thermal analysis showed thermal stability for all samples below 200 °C. The application of hydrogel as a soil conditioner confirmed the efficiency in lettuce cultivation if applied in an optimal dose. The presence of nanoclay in the polymeric matrix enhanced the germination, the development and the quality of the tested seedlings. The results showed that nanocomposites are promising products in a culture medium that need controlled release and soil conditioners.
9

Chemical modification of lignocelluloses - their accessibility in selected reaction systems for the preparation of hydrogels / Chemische Modifizierung von Lignocellulosen - ihre Zugänglichkeit in ausgewählten Reaktionssystemen für die Herstellung von Hydrogelen

Heise, Katja 05 June 2018 (has links) (PDF)
The world population is growing exponentially. At the same time, the availability of natural resources decreases dramatically – an alarming trend which demands for a sustainable use of our resources in a circular economic framework and hence, for the valorization of wastes and by-products. Owing to its high annual abundance, lignocellulosic biomass has a promising potential as renewable resource for the development of high-value products, covering fuels, platform chemicals, and specialty polymers. Besides, lignocelluloses offer an attractive basis for material applications, considering their peculiarity as natural composites and their inherent modifiability. Therefore, targeted chemical modifications have been widely used to exploit this potential and to further increase their spectrum of characteristics and application prospects. The objective of this study was to fabricate lignocellulose-based hydrogels, with the prospect to be used as soil conditioners in agriculture. Considering this application, this study was striving for the development of a simple synthetic pathway that ideally guarantees non-toxic and biodegradable products. Besides, two key factors were involved in the development of the synthetic route and constitute the center of this study: the accessibility of lignocelluloses towards chemical modifications – in view of their inherent recalcitrance – and the envisaged properties of the hydrogel, including high swelling rates and structural stability. To comply with both key factors, three basic processing steps were carried out: (1) feedstock activation by chemical or mechanical pretreatments, (2) introduction of ionic groups to induce swelling properties and (3) gel network formation via chemical crosslinking. Furthermore, to elucidate the behavior of different biomass types, wheat straw and beech sawdust were exemplarily surveyed. In the first step, different chemical (ozonolysis, alkaline and sulfite pulping) or mechanical (short-time ball milling) pretreatment approaches were used to activate the feedstocks by inducing compositional and/or structural alterations. In the second processing step, two modification reactions – carboxymethylation and phosphorylation (with phosphoric acid/molten urea) – were examined with emphasis on their ability to access lignocellulosic matrices and to realize high contents of ionic groups. In the final step, covalently crosslinked gel networks were formed using either citric acid or electron beam irradiation. Both crosslinking approaches were evaluated in detail with respect to yield and properties of the resulting hydrogels. In view of the two key factors proposed for this study – the accessibility of lignocelluloses and the final hydrogel properties – and amongst the approaches examined, the following synthetic pathway delivered the most promising results: ball milling ⟶ carboxymethylation ⟶ citric acid crosslinking. In this process, the promoting effect of ball milling can be attributed to particle size reduction, a breakdown of plant cell structures, and a decline of the cellulose crystallinity. The effectivity of carboxymethylation was particularly based on its alcoholic-alkaline media. Therefore, the uptake of alkali induced a partial disintegration of the lignocellulosic matrix, facilitating both the introduction of ionic groups and high swelling rates of the final gels. Overall, this path delivered promising results for straw-based gels, whereas beech sawdust was hardly accessible.
10

Polímeros como condicionadores de substrato em mudas associados a três lâminas de irrigação / Polymers as substrate conditioners in seedlings associated with three irrigation blades

Pradela, Valter Alves 09 November 2016 (has links)
Submitted by Michele Mologni (mologni@unoeste.br) on 2018-08-02T14:10:57Z No. of bitstreams: 1 Valter Alves Pradela.pdf: 805718 bytes, checksum: a1e7be8282642614c408dd3af31ccf75 (MD5) / Made available in DSpace on 2018-08-02T14:10:57Z (GMT). No. of bitstreams: 1 Valter Alves Pradela.pdf: 805718 bytes, checksum: a1e7be8282642614c408dd3af31ccf75 (MD5) Previous issue date: 2016-11-09 / The objective of the project was to verify the use of synthetic hydro-seed polymers as soil conditioners together with the formation of pre-sprouted seedlings (MPB) of sugarcane. The research was conducted in the greenhouse of FATEC of Presidente Prudente - SP. The material studied was cultivar RB 86 7515. The substrate used was Bioplant®. The treatments consisted of eight doses (0; 1; 2; 3; 4; 8; 20; 40 g L-1) of a superabsorbent polymer (Hidrogel®), added to the substrate prior to filling the tubes. The sugarcane minirrebolos were heat treated and planted in trays, inside the greenhouse along with the substrate, being irrigated daily (15 mm per day). At 10 days, each pre-budded seedling was removed from the tray and placed in tubes (290 mL). At 31 days, the seedlings were transferred to full sun condition and submitted to three different daily irrigation slides (5, 10 and 15 mm), remaining in these conditions until the end of the experiment, totaling 60 days. It was considered the Factorial design, with eight treatments (dosages), three irrigation slides (5, 10, and 15 mm) and five replicates (seedlings in tubes), the means being compared by the Scott-Knott test (p <0, 05). Multiple regressions were performed using Microcal Origin software, with only those that presented significant "F" at 5%. Two types of analysis were carried out, one being destructive, where plants were sampled and conducted to the laboratory, and another one of non-destructive nature, in which the variables were obtained through surveys. It was found that the use of different doses of the polymer negatively affects the mass of the roots. The fresh mass of the aerial part was positively affected with the use of polymers, whereas the dry mass presented an inverse relation. The doses of 8 g L-1 and 20 g L-1 with irrigation of 15 mm presented better results for shoot production. The values of photosynthetic rate, CO2 concentration and stomatal conductance were affected by the treatments, and the dose of 4 g L-1, with the lowest irrigation level (5 mm), already presented differences. In relation to the water flow, it was observed that the irrigation slides and the polymer doses positively affected this parameter. The aerial parts and roots were positively affected by irrigation and negatively affected by the polymer. / O objetivo do projeto foi verificar a utilização de polímeros sintéticos hidroretentores como condicionadores de solo junto a formação de mudas pré-brotadas (MPB) de cana-de-açúcar. A pesquisa foi conduzida na casa de vegetação da FATEC de Presidente Prudente - SP. O material estudado foi o cultivar RB 86 7515. O substrato utilizado foi o Bioplant®. Os tratamentos consistiram de oito doses (0; 1; 2; 3; 4; 8; 20; 40 g L-1) de um polímero superabsorvente (Hidrogel®), adicionados ao substrato antes do enchimento dos tubetes. Os minirrebolos de cana-de-açúcar foram tratados termicamente e plantados em bandejas, dentro da casa de vegetação juntamente com o substrato, sendo irrigados diariamente (15mm por dia). Aos 10 dias, cada muda pré-brotada foi removida da bandeja e colocada em tubetes (290 mL). Aos 31 dias, as mudas foram transferidas para condição de pleno sol e submetidas a três diferentes lâminas de irrigação diária (5, 10 e 15 mm), permanecendo nessas condições até o final do experimento, totalizando 60 dias. Foi considerado o delineamento Fatorial, com oito tratamentos (dosagens), três lâminas de irrigação (5, 10, e 15 mm) e cinco repetições (mudas em tubetes), sendo as médias comparadas pelo teste de Scott-Knott (p<0,05). As regressões múltiplas foram realizadas utilizando software Microcal Origin, sendo utilizadas apenas as que apresentaram “F” significativo à 5%. Realizaram-se dois tipos de análise, sendo uma destrutiva, onde plantas foram amostradas e conduzidas ao laboratório, e outra de natureza não destrutiva, na qual as variáveis foram obtidas através de levantamentos. Constatou-se que a utilização de diferentes doses do polímero afeta negativamente a massa das raízes. A massa fresca da parte aérea foi positivamente afetada com a utilização de polímeros, já a massa seca apresentou uma relação inversa. As doses de 8 g L-1 e 20 g L-1 com irrigação de 15 mm apresentou melhores resultados para produção de parte aérea. Os valores de taxa fotossintética, concentração de CO2 e condutância estomática foram afetados pelos tratamentos, sendo a dose de 4 g L-1, com o menor nível de irrigação (5 mm), já apresentava diferenças. Com relação ao fluxo de água, tem-se que as lâminas de irrigação e as doses de polímero afetaram positivamente este parâmetro. As partes aéreas e raízes foram afetadas positivamente pela irrigação e negativamente pelo polímero.

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