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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

Piktžolių naikinimo infraraudonaisiais spinduliais tyrimai / Weed control infrared analysis

Žalnieriūnaitė, Sandra 09 June 2009 (has links)
Magistro tezių tema – infraraudonųjų spindulių poveikio augalams tyrimai. Darbo apimtis 48 puslapiai, 30 paveikslų, 3 lentelės. Rašant darbą, remtasi 46 literatūros šaltiniais. Tyrimų objektas – laboratorinių bandymų metu, buvo matuojama stiebo šerdies skersmens įkaitimo trmperatūra trijų rūšių piktžolių: trikertės žvaginės (Capsella bursa), žliūgės (Stellaria media) ir paprastosios žilės (Senecio vulgaris). Įkaitimo iki 70 °C temperatūra laikoma pakankama suardyti piktžolių ląstelėms, nes piktžolę veikiant aukšta temperatūra, jų ląstelės staiga įkaista, sukreša baltymai ir sutrūkinėja jų apvalkalai, todėl sutrinka medžiagų apykaita ir augalas žūsta. Šio darbo tikslas – ištirti piktžolių trikertės žvaginės, žliūgės ir paprastosios žilės šiluminį jautrumą naudojant infraraudonųjų spindulių įrenginį ir šio įrenginio efektyvumą. Laboratoriniais tyrimais nustatėme, kad kaitinant infraraudonųjų spindulių įrenginiu piktžolių stiebus greičiausiai iki 70 oC įkaista žliūgė (1,4 mm skersmens per 3s.),o lėčiausiai paprastoji žilė (1,45 mm skersmens per 10,8s ). Kai įrenginys trauktas 0,10 m/s greičiu, buvo sunaikintos visos piktžolės, o kai įrenginys trauktas 0,14 m/s – 75% piktžolių. Piktžolių naikinimo infraraudonaisiais spinduliais efektyvumas išryškėja po kelių dienų. Piktžolės jau neatsigauna, nes jos išdžiūsta. / Summary Subject of investigation – the infrared effects of plant Subject of investigation - the infrared effects of plant research. The text corpus constitutes of 48 pages, including 30 pictures and 3 tables, 46 literature sources are used Research laboratory tests, were measured in the core of the stem diameter of heating trmperatūra three types of weeds: Capsella bursa, Stellar media and the Senecio vulgaris. Warm to 70 ° C is considered sufficient to destroy the cells of weeds, because weeds in the high temperature, the cells suddenly heated, clotting proteins and crazy in their shells, and therefore violated the metabolism and the plant dies. The aim of this work - to examine weed clang, and the simple gray thermal sensitivity using infrared ray device and the device performance. Laboratory studies have found that the infrared heating device is likely to weed stems up to 70 ° C heated Stellar media (1,4 mm in diameter through 3s.), and the simple gray slowest (1,45 mm in diameter through 10,8 s). When the device is included in 0,1 m / s, all the weeds were destroyed, and the device included a 0,14 m / s - 75% of weeds. Weeding infrared efficiency become apparent after a few days. Weed is not already, and because they are killed.
2

Metoder för vegetationsbekämpning på banvallar : en summering av resultat från UICs Vegetation Control Project och erfarenheter från Institutionen för landskaps- och trädgårdsteknik = Vegetation control methods on railway embarkment and track area/

Eriksson, Anna-Mia. Hansson, David. Huisman, Mark. Lundh, Jan-Erik. January 2004 (has links) (PDF)
Examensarbete. / Delrapport i FoU-projekt S 01-3284/08 "Skötsel av vegetation inom banområde"
3

E-weeding at Academic Libraries : Digital collection management and weeding practices at Swedish university libraries

Granström, Beate, Häller, Nadia January 2022 (has links)
Weeding is one of the central tasks of collection management at academic libraries but is often not prioritized. Digital collections are constantly growing and soon there will be a need to manage these resources. This master thesis explores the general state of weeding and e-resource weeding to uncover how these practices are understood and enacted at Swedish academic libraries, while also introducing the term e-weeding. A mixed method study was conducted and both quantitative and qualitative content analysis were performed on policy documents and interview transcripts respectively. Sentiments, opinions and current practices surrounding weeding and e-weeding at Swedish academic libraries were investigated and discussed. It was observed that most policy documents did not mention practices that could be understood as e-weeding, but some presented guidelines for print weeding. From the interviews, respondents had no consensus around a definition of e-weeding but practices commonly thought of as digital collection management could be tied to this term. In addition, print weeding was considered by respondents as more acute than e-weeding due to the intangible nature of digital resources. Lastly, it was revealed that criteria used for print weeding could sometimes be used for evaluating digital resources, although unique aspects of e-resources need to be considered. Nevertheless, respondents were open to the idea of e-weeding their digital collections in the future.
4

Banco de sementes vi?veis e manejo de plantas daninhas em sistemas de cultivo do tomateiro industrial / Viable seed bank and weed management in industrial tomato cropping systems

ROSA FILHO, Sebasti?o Nunes da 30 July 2017 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-01-26T16:05:57Z No. of bitstreams: 1 2014 - Sebasti?o Nunes da Rosa Filho.pdf: 2091591 bytes, checksum: f35a1bfbdc5bdd66764178c67ffba67b (MD5) / Made available in DSpace on 2018-01-26T16:05:57Z (GMT). No. of bitstreams: 1 2014 - Sebasti?o Nunes da Rosa Filho.pdf: 2091591 bytes, checksum: f35a1bfbdc5bdd66764178c67ffba67b (MD5) Previous issue date: 2017-07-30 / CAPES / Industrial tomato production is hampered by weed occurrence, which may reduce productivity through competition, affect the efficiency of products applied to crops and host commercially important diseases and pathogens. Thus, this study aimed to evaluate the occurrence and management of weeds in industrial tomato cropping systems in the Cerrado of Goi?s. In Chapter One, the viable seed bank was evaluated in areas with different weed management systems. The evaluation was made in two conventional tillage areas (CT); two with no-till (NT) and four with no-till and reduced soil preparation (RSP). The most frequent weeds were Conyza bonariensis, Cenchrus echinatus, Ipomoea aristolochiaefolia, Leonotis nepetifolia, Spermacoce latif?lia, Senna obtusifolia, Nicandra physaloides, Euphorbia heterophylla, Gnaphalium spp., Brachiaria plantaginea, Zea mays, Bidens pilosa, Macroptilium spp., , Solanum lycopersicum (tiguera), Commelina benghalensis and Sida rhombifolia. Among the soil preparation systems, reduced preparation (RSP) resulted in two species with higher germination: Phyllanthus tenellus and Oxaliss pp. Conventional tillage (CT) resulted in six species with the highest plant emergence number ? Ageratum conyzoides, Coronopus didymus, Portulaca oleracea, Eragrostis pilosa, Digitaria horizontalis and Solanum americanum. In Chapter Two, different systems of weed management in tomato crops for industrial processing under center-pivot irrigation were evaluated. The applied treatments were combinations between harrowing and chemical management with glyphosate, s-metolachlor, sulfentrazone and metribuzin-based products at different application periods. The variables plant population and ?Brix were not influenced by the treatments. There was statistical difference within the production components: twenty-fruit mass, yield per plant and productivity. Highest productivity was observed in the following treatments: a) harrowing thirty days after transplant (DAT), application of glyphosate (1,080 g ha-1), metribuzin (480 g ha-1) and s-metolaclhor (1,200 g ha-1) on the seventh DAT (83.39 t ha-1); harrowing on the 30th DAT, glyphosate (1,080 g ha-1) and s-metolachlor (1,200 g ha-1) on the seventh DAT (74.75 t ha-1); c) harrowing on the thirtieth DAT, glyphosate (1,080 g ha-1) on the 14th DAT and sulfentrazone (100 g ha-1) on the seventh DAT (73.06 t ha-1); d) harrowing on the 30th DAT, glyphosate (1,080 g ha-1) on the 14th DAT and s-metolachlor (1,200 g ha-1) on the seventh DAT (71.83 t ha-1) and; e) harrowing on the 30 DAT, glyphosate (1,080 g ha-1) and sulfentrazone (100g ha-1) on the seventh DAT (71.75 t ha.-1).With the ?no weeding? and ?harrowing-only? treatments, there was reduction of 63.82% and 69.29% in fruit productivity, respectively, compared to the weeded sample. The conclusion is that the applications of sulfentrazone (100 g ha-1) or s-metolachlor (1,200 g ha-1) in weed management systems using glyphosate revealed potential alternatives for industrial tomato production in Goi?s. / O cultivo de tomateiro industrial ? prejudicado pela ocorr?ncia de plantas daninhas que podem reduzir a produtividade por competi??o, afetar a efici?ncia de produtos aplicados nas lavouras e serem hospedeiras de pragas e pat?genos de import?ncia comercial. Com isso, este trabalho teve como objetivos avaliar a ocorr?ncia e o manejo de plantas daninhas em sistemas de cultivo de tomateiro industrial no Cerrado goiano. No primeiro cap?tulo, avaliou-se o banco de sementes vi?veis de ?reas com diferentes sistemas de manejo de plantas daninhas. As avalia??es foram feitas em duas ?reas de plantio convencional (PC), duas de plantio direto (PD) e quatro de plantio direto modificado com preparo reduzido do solo (PPR). As esp?cies de plantas daninhas mais frequentes foram Conyza bonariensis, Cenchrus echinatus, Ipomoea aristolochiaefolia, Leonotis nepetifolia, Spermacoce latif?lia, Senna obtusifolia, Nicandra physaloides, Euphorbia heterophylla, Gnaphalium spp., Brachiaria plantaginea, Zea mays, Bidens pilosa, Macroptilium spp., Solanum lycopersicum(tiguera), Commelina benghalensis, Sida rhombifolia. Entre os sistemas de preparo do solo, o preparo reduzido (PPR) apresentou duas esp?cies entre as de maior germina??o, a esp?cie Phyllanthus tenellus e a Oxalis spp. O plantio convencional (PC) apresentou tr?s esp?cies com maior n?meros de plantas emergidas, sendo Eleusine indica, Digitaria horizontalis e Amaranthus hybridus. O plantio direto (PD) teve seis esp?cies com maior emerg?ncia em compara??o aos outros manejos de solo, sendo Ageratum conyzoides, Coronopus didymus, Portulaca oleracea, Eragrostis pilosa, Digitaria horizontalis e a Solanum americanum. No segundo cap?tulo, objetivou-se avaliar diferentes sistemas de manejo de plantas daninhas na cultura do tomateiro para processamento industrial em parte de lavoura comercial sob piv? central. Os tratamentos utilizados foram combina??es entre o uso da gradagem e manejo qu?mico com produtos ? base de glyphosate, s-metolachlor, sulfentrazone e metribuzin em diferentes ?pocas de aplica??o. As vari?veis popula??o de plantas e ?Brix n?o foram influenciadas pelos tratamentos. Houve diferen?as estat?sticas para os componentes de produ??o: massa de vinte frutos, produ??o por planta e produtividade. As maiores produtividades foram observadas nos seguintes tratamentos: a) gradagem aos trinta dias antes do transplantio (DAT), aplica??o de glyphosate (1.080 g ha-1), metribuzin (480 g ha-1) e de s-metolaclhor (1.200 g ha-1) aos sete DAT (83,39 t ha-1); b) gradagem aos 30 DAT, glyphosate (1.080 g ha-1) e s-metolachlor (1.200 g ha-1) aos sete DAT (74,75 t ha-1);c) gradagem aos trinta DAT, glyphosate (1.080 g ha-1) aos 14 DAT e sulfentrazone (100 g ha-1) aos sete DAT (73,06 t ha-1); d) gradagem aos 30 DAT, glyphosate (1.080 g ha-1) aos 14 DAT e s-metolachlor (1.200 g ha-1) aos sete DAT (71,83 t ha-1) e ; e) gradagem aos 30 DAT, glyphosate (1.080 g ha-1) e sulfentrazone (100 g ha-1) aos sete DAT (71,75 t ha.-1). Nos tratamentos ?sem capina? e ?apenas gradagem?, houve redu??o de 63,82% e 69,29% na produtividade de frutos, respectivamente, em rela??o ? testemunha capinada. Conclui-se que as aplica??es de sulfentrazone (100 g ha-1) ou s-metolachlor (1.200 g ha-1), em sistemas de manejo de plantas daninhas contendo glyphosate, se revelaram alternativas potenciais na cultura do tomateiro industrial em Goi?s.
5

Gallring i allmänhetens tjänst? : en kvantitativ undersökning om gallringsprinciper på svenska folkbibliotek / Weeding for the public good? : a quantitative study regarding weeding practices at public libraries in Sweden

Hjalmarsson, David, Lindström, Patrik January 2012 (has links)
The purpose of this bachelor's thesis is to examine how public libraries in Sweden handles their weeding procedures. A series of questions are asked: How does libraries in Sweden motivate weeding? What principles constitutes the procedure of weeding? Which aspects are given most importance when weeding is decided. How does views on weeding differ between libraries of different sizes? How does longer or shorter professional experience influence the view on weeding? The study was done through an online questionnaire which was sent to a number of staff members on different libraries via e-mail. Based upon a previous study by Dilevko and Gottlieb, the staff members were asked to value different alternatives on questions concerning why they weed, criterias used for weeding decisions, reasons why weeding is not done, factors discouraging weeding, what is done with the weeded items and what sort of changes could improve the weeding procedure. Results from the survey confirms physical condition, accuracy of information and circulation as the three prime criteria for weeding. Answers about attitudes towards weeding showed a widespread consensus among library personnel regarding the positive effects of weeding. Additionally, results also show some difference between small- and larger-sized libraries where the small-sized libraries seem to take a rather patron-driven approach to weeding, thus leading to a more market-adapted role. In contrast larger-sized libraries seem to weed more out of a culture-intermediate role, giving qualitative criterias such as accuracy of information larger importance than circulation statistics.
6

Religião, negociação e família: um estudo antropológico sobre o casamento judaico em Manaus

Paiva, Paula Gama de 31 March 2010 (has links)
Made available in DSpace on 2015-04-11T13:59:45Z (GMT). No. of bitstreams: 1 Paula Gama.pdf: 772136 bytes, checksum: e4c34cd1698fc715391db2699151155e (MD5) Previous issue date: 2010-03-31 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This dissertation is an anthropological study on wedding in a Jewish community in Manaus city. The research subject is to understand the logic and the values that reign matrimonial union, the affinities hat create the meeting conditions and the way as the families face with the possible cultural differences of this union. On differences that do not resume, necessarily, to ethnic belonging. I observe specifically the couples formed by one of Jewish origin s member at Manaus middle class. Such wedding seeing as an intersection point of individual biographies and social trajectories are good to think on social identities constructions at metropolis, in other words the individual and society relation, the preservation and reproduction of collective memories, modernity and tradition, and finally the transmission of memories through the generations. / Essa dissertação é um estudo antropológico sobre o casamento na comunidade judaica de Manaus. O objetivo desta pesquisa é compreender a lógica e os valores que regem a união matrimonial, as afinidades que criaram as condições para o encontro e o modo como as famílias lidam com as possíveis diferenças culturais a partir desta união. Diferenças estas que não se resumem, necessariamente, ao pertencimento étnico. Trato especificamente de casais formados por pelo menos um cônjuge de origem judaica, oriundos das camadas médias da cidade de Manaus. Tais casamentos, tomados como um ponto de intercessão entre biografias individuais e trajetórias sociais, são bons para pensar sobre a construção de identidades sociais na metrópole, ou seja, a relação indivíduo/sociedade, a preservação e reprodução das memórias coletivas, as relações entre modernidade e tradição, e, finalmente, a transmissão das memórias através das gerações.
7

Bibliotek i Umeå stads medieplanering kring tv-spel

Beckeman, Daniel January 2023 (has links)
This paper aims to examine the various practices employed by libraries in the city ofUmeå in regards to the collection development of their video game selection.In addition to directly examining this process, it will also seek to develop anunderstanding of how different factors impact it, such as technical aspects, ageratings, genres, and game platforms. The study was conducted using both aqualitative and quantitative method, using interviews to gather insights fromlibrarians and a variety of statistical sources to build an image of the contents of thelibrary. The results indicated that the collection development endeavors were bothless frequent and needed compared to the book collections, in great part due to thelimited size of the selection. It was also found that the collections that did exist weregreatly influenced by the library patrons that engaged with them, with the cataloguemostly mirroring the demand in proportion, with the outlier of Nintendo Switchgames. Finally, a potential issue regarding the future of video game acquisition wasraised due to the evolving digital market potentially rendering library servicesobsolete or too expensive. In conclusion, this study found that unless the videogame market drastically shifts course from its digitalization the services librariesprovide in regards to this medium has to adapt to stay relevant to public interests
8

Use of Flame Cultivation as a Nonchemical Weed Control In Cranberry Cultivation

Ghantous, Katherine M. 01 September 2013 (has links)
Cranberry (Vaccinium macrocarpon Ait.) is a woody perennial crop that can remain productive for decades. Competition for resources between cranberries and weeds can depress cranberry farm yields, resulting in large annual crop losses. Renewed interest in reducing chemical inputs into cranberry systems has provided the motivation to evaluate methods, such as flame cultivation (FC), as potential nonchemical options for weed control. Also known as thermal weeding, FC exposes plants to brief periods of high temperature that causes the water in the plant tissue to expand rapidly, rupturing plant cells and leading to necrosis. Various FC methods have been used successfully in annual crops as both a preemergence and postemergence weed control, but few scientific reports have been published on the use of FC on perennial weeds in a woody perennial crop system. Dewberry (Rubus spp.), sawbrier (Smilax glauca), and common rush (Juncus effusus) are cranberry weeds that are difficult to control, spread quickly and can cause significant crop loss. Flame cultivation may be an effective non-chemical means for controlling these weeds in cranberry systems. FC would ideally be used as a spot treatment for weeds growing in the cranberry canopy, as well as on larger non-production areas where cranberry vines are not as abundant, such as bog edges, ditches, and dikes. Using FC to treat weeds within the cranberry canopy will likely cause localized damage to cranberry plants immediately surrounding the weeds, thus cranberry response to FC is also of interest. The following experiments were designed to examine the response of weeds and cranberry plants to FC. Perennial plants rely on reserves of nonstructural carbohydrates (NSC) for growth and survival, thus the efficacy of FC treatments to weeds will likely be impacted by the timing and frequency of treatments as they relate to the specific carbohydrate cycles of targeted weeds, such as dewberry. An additional experiment studied the seasonal fluctuations of NSC in dewberry roots. Cranberry growers were also surveyed on their past experiences with FC, as well as their willingness to adopt FC if proven an effective method for controlling weeds.
9

Acquisitions done innovatively: streamlining workflows within the Acquisitions department

January 2017 (has links)
Yes / In the last 10 years the University of Bradford Library Acquisitions Department has shrunk from 13 members of staff to 5. This has led to us embracing new technology to help streamline workflows within the department. As well as utilising EDI functionality, changing processing workflows and using shelf-ready books, we have devised innovative ways of dealing with everyday tasks. Topics included cover: PDA deduplication; spine labelling on a large scale; the weeding of discarded books; using saved global updates on incoming MARC records and using load profiles innovatively.
10

Weed dynamics in low-input dryland smallholder conservation agriculture systems in semi-arid Zimbabwe

Mashingaidze, Nester 06 May 2013 (has links)
The reported requirement for a higher weeding effort due to increased weed infestations under conservation agriculture (CA) relative to conventional mouldboard plough tillage is perceived by both smallholder farmers and extension workers as the main limiting factor to the widespread adoption of CA by smallholder farmers in southern Africa. However, proponents of CA argue that weeds are only a problem under CA in the initial two years and decline afterwards resulting in reduced labour requirements for weeding under CA. They further posit that weeds are only major problem where minimum tillage (MT) is adopted without crop residue mulching and diverse crop rotations. This thesis explores the effect of time under CA on weed population dynamics and crop growth under the recommended CA practices and actual smallholder farmer practice in semi-arid Zimbabwe. Assessment of weed and crop growth on a long-term CA experiment at Matopos Research Station revealed that the MT systems of planting basins and ripper tine were associated with higher early season weed density and biomass than conventional early summer mouldboard tillage (CONV) in both the fifth (cowpea phase) and sixth (sorghum phase) years of CA. This increased weed infestation within the first four weeks after planting in CA necessitated early weeding to provide a clean seedbed and avert significant crop yield loss. Maize mulching only suppressed early season weed growth in sorghum mostly at a mulch rate of 8 t ha-1 which is not a mulching rate that is attainable on most smallholder farms. However, the lower maize residue mulch rate of 4 t ha-1 was consistently associated with increased weed emergence and growth as from the middle of the cropping season in both crop species. The increased weed infestations under the mulch were probably due to the creation of ‘safe sites’ with moist conditions and moderate temperatures. The high weed growth under the mulch contributed to the low sorghum grain yield obtained under mulched plots. In addition, maize mulching was also associated with a less diverse weed community that was dominated by the competitive Setaria spp. and difficult to hoe weed Eleusine indica (L.) Gaertn. However, the weed community under CA was similar to that under CONV tillage with no evidence of a shift to the more difficult to control weed species. The increased early season weed growth and high weed pressure under CA meant that it was still necessary to hoe weed four times within the cropping season to reduce weed infestations and improve crop growth even after four years of recommended CA practices. Early and frequent weeding was effective in reducing weed growth of most species including Setaria spp. and E. indica demonstrating that on smallholder farms where labour is available hoe weeding can provide adequate weed control. The wider spacing recommended for use in CA contributed to the low cowpea and sorghum grain yields obtained under CA compared to CONV tillage. On smallholder farms in Masvingo District, the MT system of planting basin (PB) was the only conservation farming (CF) component adopted by farmers. There was no difference in the total seedling density of the soil weed seed bank and density of emerged weeds in the field in PB and conventional mouldboard ploughing done at first effective rains (CONV tillage). However, the first weeding in PB was done at least 15 days earlier (P < 0.05) than in CONV tillage suggesting high early season weed growth in PB relative to CONV tillage. As weed density did not decline with time in PB, weed management did not differ with increase in years under PB. Shortage of inputs such as seed and fertiliser was identified by smallholder farmers as the most limiting factor in PB crop production with the area under PB was equivalent to the seed and fertiliser provided by CARE International for most farmers. On this small area, weeds could be managed by available family labour. Double the maize grain yield was obtained in PB (mean: 2856 kg ha-1) due to improved weed management and soil fertility. However, the use of poorly stored composts was found to introduce weeds into some PB fields. The findings of this study demonstrated that weed pressure was still high and weed management were still a challenge under the practice recommended to smallholder farmers in Zimbabwe even in the sixth year of practice. There is, therefore, a need for research on the economic feasibility of using herbicides, intercropping and optimal crop density to ameliorate the high weed pressure under CA. / Thesis (PhD)--University of Pretoria, 2013. / Plant Production and Soil Science / unrestricted

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