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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.
61

Modularni sistem za projektovanje alata za injekciono presovanje plastike / Modular system for plastic injection molding

Matin Ivan 15 May 2014 (has links)
<p>U disertaciji se prikazuje modularni sistem za projektovanje alata za<br />injekciono presovanje plastike. Analizirani su različiti prilazi u<br />projektovanu alata. Prikazana je koncepcija i funkcionisanje<br />razvijenog sistema. Verifikacija sistema je izvr&scaron;ena na konkretnim<br />plastičnim proizvodima. Na kraju su dati odgovarajući zaključci i<br />mogući pravci budućih istraživanja.</p> / <p>The dissertation shows the development of the modular system for<br />mold design for plastic injection molding. Different approaches were<br />analyzed in the field of mold design. The concept and functioning of<br />the developed modular system is presented. Validation of the<br />proposed system is made with the specific plastic parts. At the end<br />the appropriate conclusions and possible directions for future<br />research are given.</p>
62

Transfer Mold Design

Wang, Xiaoyan, Patel, Parthkumar January 2019 (has links)
The following report conducted with the collaboration with the University of Halmstad and Halmstad Gummi Fabric (HGF) rubber company which is in Halmstad. The focus on the project is to reduce the cost of the transfer mold material, increase efficiency of production, save energy and redesign the transfer mold. The methodology used in this project is based on the Quality Functional Deployment (QFD) which is widely appreciated globally in the product development, and other product development and mold design methods, FEM analysis are applied to achieve the goals. The implementation of this methods is efficient and beneficial to reduce the material cost and redesign the transfer mold without compromising the initial quality of the product. This thesis resulted in, for the transfer molding plates we recommended the proper material for the plates and the insulation parts. And we redesign the transfer mold plates and optimized the design for reducing the cost. We did FEM analysis for optimization purpose, and the benefits to optimizing this is to reduce the material cost, machining cost and labour cost. As well as, we add the insulation plates in the design so that the transfer molding plates works efficiently with the reducing the energy wastes.
63

Estudo do processo de replicação por laminação em polimetilmetacrilato (PMMA) aquecido / Study of the replication process by rolling of heated polimetilmethacrylate (PMMA)

Javarez Junior, Laercio 24 November 2009 (has links)
O crescente aumento na demanda de sistemas miniatuarizados, a criação e desenvolvimento de métodos simples e eficazes e com menor custo de fabricação de microcomponentes desafiam projetistas e pesquisadores. Dentro deste contexto, este trabalho visa o estudo do processo de replicação por laminação, com PMMA (polimetilmetacrilato) aquecido, para geração de microestruturas. O laminador utilizado é de precisão e a distância entre rolos possui controle milimétrico garantindo sua distância, mesmo quando em operação. Foi confeccionado um cilindro molde contendo microrranhuras que serão replicadas no PMMA. Utilizaram-se, como material do cilindro molde, o alumínio e a liga de alumínio 7075. O processo de aquecimento do PMMA consistiu de duas maneiras: condução através do contato com placa térmica, e convecção através do aquecimento em estufa. Para PMMA identificou-se a temperatura ótima para replicação a 105°C. O estudo demonstrou que, para replicar uma geometria com taxa de replicação elevada, devem-se levar em consideração fatores como a velocidade de laminação e a taxa de redução (distância entre cilindros). Este trabalho vai de encontro a pensamentos inovadores, demonstrando ser uma técnica que permite obter a replicação de determinadas geometrias com eficiência de produção. / The increasing demand for miniatuature systems, the creation and development of simple, effective and low cost manufacturing mehods of microcomponents challenge designers and researchers. Within this context, this work aims to study the replication process by rolling of heated PMMA (polymethylmethacrylate) to generate microstructures. A precision mill roll is used so that the distance between rolls has millimeter adjustment ensuring the distance is kept constant, even while in operation. A cylinder mold containing microgrooves to be replicated in PMMA was fabricated. Aluminum and 7075 aluminum alloy were used for the cylinder mold. The process of heating the PMMA occurred in two manners: conduction through the contact thermal plate, and convection by heating in an oven. For PMMA, the temperature for replication of 105°C was identified as being optimum. The study showed that, to replicate a geometry with a high rate of replication, one should take into account factors such as the rolling speed and the rate (distance between cylinders). This work goes towards the innovative thinking, proving to be a technique that allows for the replication of certain geometries and production efficiency.
64

Sclerotinia sclerotiorum em sementes de soja: sobrevivência, efeito na germinação, tamanho de amostra para análise e eficiência in vitro de fungicidas / Sclerotinia sclerotiorum in soybean seeds: survival, effect on germination, sample size for analysis and in vitro efficiency of fungicides

Camargo, Meyriele Pires de 27 January 2014 (has links)
O fungo Sclerotinia sclerotiorum, agente causal do mofo branco, encontra-se disseminado em todo o país e afeta mais de 400 espécies de plantas, dentre elas a cultura da soja, causando danos consideráveis no rendimento. A transmissão do patógeno ocorre por meio de sementes contendo micélio dormente ou pela presença de escleródios no lote, os quais podem permanecer viáveis por um longo período, dificultando o manejo da doença. Este trabalho teve como objetivos verificar a viabilidade do patógeno em sementes durante o armazenamento e seu efeito sobre o poder germinativo; comparar tamanhos de amostras de sementes visando à detecção do fungo; e avaliar a sensibilidade in vitro de S. sclerotiorum a fungicidas. Para avaliação da sobrevivência do patógeno, sementes de soja foram inoculadas, artificialmente, com três isolados de S. sclerotiorum, e armazenadas em duas condições, câmara fria e seca (20 ºC e 45% UR) e ambiente não controlado, durante oito meses. A cada dois meses foram realizados testes de sanidade pelo meio de cultura ágar-bromofenol (Neon), utilizando-se 4 repetições de 100 sementes, e testes de germinação, com 4 repetições de 50 sementes, pelo método do rolo de papel. No experimento de amostragem foram avaliadas dez amostras de sementes de soja pelo método do meio Neon, comparando-se quatro tamanhos de amostra: 400, 800, 1600 e 2400 sementes. Para avaliação da sensibilidade in vitro de S. sclerotiorum a fungicidas, foram utilizados 13 ingredientes ativos, em 7 doses e 5 repetições. Os valores da concentração inibitória de 50% (CI50) e 100% (CI100) foram estimados com base na percentagem de inibição do crescimento micelial. Além disso, realizaram-se a quantificação e pesagem dos escleródios formados após 15 dias de incubação. A presença do patógeno S. sclerotiorum, afetou negativamente a germinação das sementes, com redução média de 32% em relação à testemunha. Verificou-se diferença entre os isolados com relação à agressividade. O patógeno sobreviveu nas sementes em ambos os ambientes de armazenamento, porém, em ambiente controlado a redução na geminação das sementes foi de 14% e na incidência do fungo de 16%, enquanto que, em laboratório, esta redução foi de 23% na germinação e de 62% na incidência. Não houve diferença estatística com relação à quantidade de sementes amostradas na detecção de S. sclerotiorum, entretanto, constatou-se maior frequência de ocorrência do patógeno à medida que o número de sementes amostrado foi maior. Todos os fungicidas foram capazes de reduzir o crescimento micelial de S. sclerotiorum, bem como a produção de escleródios, sendo que os ingredientes ativos piraclostrobina, carbendazim, tiabendazol e tiofanato metílico, além de apresentarem CI50 inferior a 1 mg L-1, também inibiram totalmente a formação de escleródios em concentrações inferiores a 5 mg L-1. / The fungus Sclerotinia sclerotiorum, the causal agent of white mold is spread throughout the country and affects more than 400 species of plants, including soybean, causing considerable decrease in yield. The pathogen transmission occurs through seeds with dormant mycelium or by the presence of sclerotia in the lot, which can remain viable for a longer period, making hard the disease management. This study aimed to verify the viability of the pathogen in seeds during the storage period and its effect on germinative power; compare sizes of seed samples to determine the presence of the fungus; and to evaluate the in vitro sensibility of S. sclerotiorum to fungicides. To determine the pathogen survival, soybean seeds were inoculated artificially with three isolates of S. sclerotiorum, and stored into two conditions, cold and dry chamber (20 °C and 45% RU) and in uncontrolled environment, for eight months. Every two months health tests were performed by culture media bromophenol agar (Neon), using 4 repetition of 100 seeds, and germination tests, with 4 repetition of 50 seeds, by the method of the paper roll. During the experiment of sampling, ten samples of soybean seeds were evaluated by the method of media Neon, comparing four sample sizes: 400, 800, 1600 and 2400 seeds. To evaluate the in vitro sensibility of S. Sclerotinia to fungicides were used 13 active ingredients, in 7 doses and 5 repetitions. The values of the 50% inhibitory concentration (IC50) and 100% (IC100) were estimated based on the percentage inhibition of the mycelial growth. In addition, it was performed the quantification and weighing of sclerotia formed after 15 days of incubation. The pathogen S. sclerotiorum in soybean seeds affected negatively the germination of seeds, with an average reduction of 32% compared to the control. There was difference between the isolates in relation to aggressiveness. The pathogen survived in seeds in both storage environments, however, under controlled environment, the decrease in the germination of the seeds was 14% and in its incidence was 16%, while in laboratory this reduction was 23% in the germination and 62% in the incidence. There was no statistical difference in the quantity of seeds sampled in the detection of S. sclerotiorum, however, a higher frequency of pathogen occurrence was verified as the number of sampled seeds was enlarged. All fungicides were able to reduce the mycelial growth of S. sclerotiorum and sclerotia production, and the active ingredients pyraclostrobin, carbendazim, thiabendazole and thiophanate methyl, besides having IC50 of less than 1 mg L-1 also completely inhibited the formation of sclerotia in concentrations less than 5 mg L-1.
65

Papéis para imprimir e escrever vítimas de enchente real: recuperação por radiação gama de Co-60 / Papers to writing and printing recovered from flood: treatment by gama radiation from Co-60

Auada, Fernanda Mokdessi 08 March 2018 (has links)
Este estudo trata dos efeitos da radiação gama de Co-60 sobre papéis atingidos por um sinistro. Sete livros de arquivo corrente do séc. XXI, recuperados de enchente e que apresentaram infestação biológica, foram selecionados como amostras para a investigação da irradiação empregada como agente de desinfestação. Partindo da identificação dos principais gêneros de fungos presentes no material para determinar as doses empregadas, estudou-se os efeitos da radiação nas propriedades do papel e nas manchas de lama e de fungos. Foram consideradas doses de radiação gama compatíveis com a possibilidade de repetição do tratamento, pois acervos tratados não ficam imunes a novas infestações e as doses são cumulativas. Importante observar o limite de dose que os suportes documentais e bibliográficos suportariam, sem que ocorram danos, em caso de um novo tratamento. / This study addresses the effects of Co-60 gamma radiation on paper. Seven books of registry office archives from 21 century, recovered from flood and that presented biological infestation were selected as samples to investigate the irradiation used as fungal infection treatment. Starting with the identification of the main fungi genera present in the material to determine the doses employed, some of the radiation effects on paper properties were studied as well as on mud and fungus stains. The gamma radiation doses compatible with the possibility of repeated treatment were also observed, because treated collections are not immune to new infestations by microorganisms and the doses are cumulative. It is important to consider the dose limit which documentary and bibliographic material could support without damages in case of a new irradiation treatment.
66

Estudo do processo de replicação por laminação em polimetilmetacrilato (PMMA) aquecido / Study of the replication process by rolling of heated polimetilmethacrylate (PMMA)

Laercio Javarez Junior 24 November 2009 (has links)
O crescente aumento na demanda de sistemas miniatuarizados, a criação e desenvolvimento de métodos simples e eficazes e com menor custo de fabricação de microcomponentes desafiam projetistas e pesquisadores. Dentro deste contexto, este trabalho visa o estudo do processo de replicação por laminação, com PMMA (polimetilmetacrilato) aquecido, para geração de microestruturas. O laminador utilizado é de precisão e a distância entre rolos possui controle milimétrico garantindo sua distância, mesmo quando em operação. Foi confeccionado um cilindro molde contendo microrranhuras que serão replicadas no PMMA. Utilizaram-se, como material do cilindro molde, o alumínio e a liga de alumínio 7075. O processo de aquecimento do PMMA consistiu de duas maneiras: condução através do contato com placa térmica, e convecção através do aquecimento em estufa. Para PMMA identificou-se a temperatura ótima para replicação a 105°C. O estudo demonstrou que, para replicar uma geometria com taxa de replicação elevada, devem-se levar em consideração fatores como a velocidade de laminação e a taxa de redução (distância entre cilindros). Este trabalho vai de encontro a pensamentos inovadores, demonstrando ser uma técnica que permite obter a replicação de determinadas geometrias com eficiência de produção. / The increasing demand for miniatuature systems, the creation and development of simple, effective and low cost manufacturing mehods of microcomponents challenge designers and researchers. Within this context, this work aims to study the replication process by rolling of heated PMMA (polymethylmethacrylate) to generate microstructures. A precision mill roll is used so that the distance between rolls has millimeter adjustment ensuring the distance is kept constant, even while in operation. A cylinder mold containing microgrooves to be replicated in PMMA was fabricated. Aluminum and 7075 aluminum alloy were used for the cylinder mold. The process of heating the PMMA occurred in two manners: conduction through the contact thermal plate, and convection by heating in an oven. For PMMA, the temperature for replication of 105°C was identified as being optimum. The study showed that, to replicate a geometry with a high rate of replication, one should take into account factors such as the rolling speed and the rate (distance between cylinders). This work goes towards the innovative thinking, proving to be a technique that allows for the replication of certain geometries and production efficiency.
67

Papéis para imprimir e escrever vítimas de enchente real: recuperação por radiação gama de Co-60 / Papers to writing and printing recovered from flood: treatment by gama radiation from Co-60

Fernanda Mokdessi Auada 08 March 2018 (has links)
Este estudo trata dos efeitos da radiação gama de Co-60 sobre papéis atingidos por um sinistro. Sete livros de arquivo corrente do séc. XXI, recuperados de enchente e que apresentaram infestação biológica, foram selecionados como amostras para a investigação da irradiação empregada como agente de desinfestação. Partindo da identificação dos principais gêneros de fungos presentes no material para determinar as doses empregadas, estudou-se os efeitos da radiação nas propriedades do papel e nas manchas de lama e de fungos. Foram consideradas doses de radiação gama compatíveis com a possibilidade de repetição do tratamento, pois acervos tratados não ficam imunes a novas infestações e as doses são cumulativas. Importante observar o limite de dose que os suportes documentais e bibliográficos suportariam, sem que ocorram danos, em caso de um novo tratamento. / This study addresses the effects of Co-60 gamma radiation on paper. Seven books of registry office archives from 21 century, recovered from flood and that presented biological infestation were selected as samples to investigate the irradiation used as fungal infection treatment. Starting with the identification of the main fungi genera present in the material to determine the doses employed, some of the radiation effects on paper properties were studied as well as on mud and fungus stains. The gamma radiation doses compatible with the possibility of repeated treatment were also observed, because treated collections are not immune to new infestations by microorganisms and the doses are cumulative. It is important to consider the dose limit which documentary and bibliographic material could support without damages in case of a new irradiation treatment.
68

Generation of Carbon Dioxide and Mobilization of Antimony Trioxide by Fungal Decomposition of Building Materials

Krause, John D 25 March 2005 (has links)
Fungal contamination of buildings poses numerous challenges to researchers, building owners and occupants. Public health agencies promote prevention and remediation of mold and water damage, but lack sensitive methods to detect hidden mold growth and a complete understanding of the biological mechanisms that make occupying moldy buildings a hazard. The wide spread use of the fire retardant antimony trioxide (Sb2O3) on building materials and furnishings makes it inevitable that mold growth on treated materials will occur in some buildings with water damage. Several authors have speculation that microbial growth on materials treated with antimony trioxide could mobilize antimony through a volatile intermediate, trimethylstibine. The purpose of this study was to determine if fungal growth on a commonly used building material that contains antimony trioxide, fiberglass ductboard, results in the mobilization and release of antimony compounds. Additionally, CO2 generation rates were determined during fungal growth on fiberglass ductboard and gypsum wallboard. Results demonstrated a significant reduction of antimony concentration in fiberglass ductboard after fungal growth had occurred. Antimony emission rates and resulting concentrations of antimony oxide aerosols were estimated using an indoor mass balance mathematical model. Concentrations of CO2 were also modeled within a wall cavity and static HVAC ducts to determine if fungal growth could elevate CO2 levels above ambient concentrations. Although volatile phase antimony was not detected in chamber experiments, probably due to rapid oxidation and high humidity, mobilization of antimony trioxide from fiberglass ductboard components was demonstrated in several experiments. Indoor Air modeling of a residence suggest that concentrations of antimony could, under worst case conditions, exceed the reference concentration (RfC) of antimony trioxide by 10 to 1,000 times. These results suggest that biomethylation and mobilization of antimony by mold growth on building materials could result in elevated occupant exposures to antimony compounds. Antimony is a known respiratory irritant that can be similar to arsenic in its toxicity. Modeling results also suggest that elevated carbon dioxide concentrations due to fungal metabolic respiration are variable and dependent on environmental conditions. Measuring elevated carbon dioxide concentrations to detect hidden fungal growth was determined to not be a predictive assessment tool.
69

我國金屬射出成型產業競爭策略 / Metal injection molding industry competitive strategy

黃孟楨, Huang, Meng Cheng Unknown Date (has links)
現今是資訊發達且多變的環境,企業要生存必須因應環境的變化。目前在機械業界中最熱門的金屬射出成形(Metal injection mold) 技術,使得零組件成形與加工技術有革命性的改變。現今全球具規模的金屬射出成形產業的供應商將近30年的歷史,過去五年都維持在約15%以上成長,個案P公司是由粉末冶金產業開始,其主力產品是汽車零件,在2008年下半年金融風暴的襲擊,汽車產業衰退,該公司在此情況,精進金屬射出成形的技術,並研發節省能源設計的新材料,提供給汽車產業和其他市場的使用;另一個案T公司在金屬射出成形產業有十多年,主要是製造形狀複雜、高精密度的機械零件。本研究希望藉由產業環境分析與個案分析,找尋金屬射出成形產業的利基點,與企業在發展和成長過程,探討出未來經營策略或可行的方案。 本研究的理論基礎主要是參考Michael Porter的產業分析(1980)對於MIM產業的總體環境和產業分析,瞭解其發展趨勢;接著引用Porter的五力分析(1985),分析個案企業面臨外在產業的環境,與其競爭優勢;最後採用Weihrich,Heinz (1982)提出SWOT矩陣策略配對,將個案公司內部的優勢、劣勢與外部的機會及威脅以矩陣結構的方式分析,利用最大之優勢和機會、及最小之劣勢與威脅,以界定出其目前所處的情況,進而研擬出個案公司適當的因應對策。 經過產業分析和個案分析後,本研究得到以下結論:(一)、影響粉末冶金、金屬射出成形產業的因素為全球經濟環境、石油價格和科技技術。(二)、粉末冶金產業的生命週期已進入成長期,金屬射出成形正邁入成長期。(三)、形狀複雜高精密度的小型機械零件,以傳統加工方式不易生產,用MIM的技術可以量產出這些複雜的形狀,減少加工的步驟,為其利基點。(四)、目前以MIM技術生產持續降低成本,縮短交期、增加其競爭優勢。(五)、產品廣泛應用在各種需要金屬零件的產業界,如個案P公司生產汽車齒輪的數量,供應全球汽車產業需求量超過三分之ㄧ,而個案T公司生產小而複雜的零部件提供給手工具、3C產品和資訊等產業,都有獲利的空間。 對於金屬射出成型產業的建議為 (一)、在各國節約能源和環保愛地球,研發技術人員需開發輕金屬零件,以因應市場需求。(二)、因歐美市場汽車需求量降低,而大陸市場汽車需求量大,因此大陸正積極的發展金屬粉末射出成形產業,並尋求台灣零件的供給,是我們拓展市場的機會。(三)、對於3C和資訊產業的產品,因其產品生命週期短,需要有專案的技術人員以最短的開發和交樣時間,以ERP管理,降低庫存,並與客戶一起開發,節省資源,降低風險。 關鍵字: 金屬射出成型(MIM),SWOT矩陣策略。 / In the fast growing IT world of today, Metal Injection Molding (MIM) technology transform the traditional manufacturing method of the metallic parts to a revolutionary fabrication process in the machinery industries. MIM actually has been developed for more than 30 years, and in the latest 5 years, the annual growth rate is about 10 to 15%. End products are commonly component items used in various industries and applications. Company P has been using powder metallurgical technology to produce auto parts. Although its business was affected by the slowdown of auto industries due to the financial storm in the second half of 2008, its advancement in the MIM technology, including the development of the energy saving material, had helped the company to survive in the downturn of auto industries. Another Company T in the case study has used the MIM technology to provide the diversified geometrically complex metal parts for more than 10 years. This study was using the tools of analysis and case studies to find the niche of metal injection molding industry for the enterprise to explore the appropriate managing strategies during they were developing and growing process of the business. The theoretical background of this study is referring to the industry analysis and 「Five Force analysis」 made by Professor Michael Porter of Harvard University in 1980 and 1985. It gives an overview and the overall environmental and competitive analysis and used for studying the development trend of the MIM industry. Using the SWOT matrix for strategy matching proposed by Weihrich in 1982, the company’s internal strengths, weaknesses and external opportunities and threats, could be analyzed and expressed in an explicit form. Then, maximize the strengths and opportunities and minimize the weaknesses and threats to define the present situation, and then develop the best applicable strategies for the company. Through industry analysis and case studies, this study concludes the followings: (1) Powder metallurgy and metal injection molding industry are affected by the global economic environment, oil prices and the technological advancement. (2) The life cycle of powder metallurgy industry is at its growth period, but the metal injection molding is at the end of embryonic period and moving to growth period. (3) Since it’s not easy to use the traditional fabrication process to make the complicated or asymmetric shaped metallic parts, the metal injection molding technology has the advantages of making the complicated parts with less fabrication steps. (4) Powder metallurgy and metal injection molding could continuously reduce costs and shorten the delivery time to increase their competitiveness. (5) The products could be widely used in various kinds of industry where the metallic parts are needed. Company P is producing one-third of the gears used in the world-wide auto industries and Company T is making the small and complex parts for the hand tools, 3C and IT industries with profits. Finally, the suggestions for metal injection molding industry are listed as follows: (1) Under the regulations of the environment protection, we should develop the energy conserving and carbon-reducing materials to meet the requirements. (2) China is developing the metal injection molding technology aggressively to meet the demand of its automobile market, which provides a great business opportunity of the auto parts supplier of Taiwan, (3) Since the life cycle of 3C and IT products is very short, the engineering team should design and fabricate the products in a very short time to the market. Also, it is necessary to use ERP management to reduce inventory and co-work with customers to develop products, conserve resources and reduce the risk.
70

Effect of nutrition on postharvest quality and grey mould development in strawberries.

Naradisorn, Matchima January 2008 (has links)
Strawberries are an extremely perishable fruit mainly due to their soft texture and sensitivity to fungal infection. The fungal pathogen Botrytis cinerea is responsible for grey mould on strawberries and is the main causal agent of postharvest decay and subsequent economic loss. As an alternative to fungicides, manipulation of plant nutrition, such as calcium and boron, has been suggested as a means of disease management. This project investigated the effects of calcium and boron application on fruit quality and grey mould development in strawberry. The effect of calcium on fruit quality, grey mould development and leaf blight in strawberry cultivars ‘Aromas’ and ‘Selva’ was investigated through preharvest and postharvest applications. To determine the effect of preharvest application, calcium sulphate in 0.25X strength Hoagland’s solution was applied at 0, 100, 300 and 500 ppm Ca through fertigation. Fully-ripened fruit were harvested and evaluated for postharvest quality at harvest and then after storage at 10⁰C, 90±5% RH for 2 to 10 days. Although fruit firmness of both cultivars declined slightly during storage, this was not affected by preharvest calcium application. Similarly, preharvest calcium treatment had no effect on the external appearance, pH, soluble solids content (SSC) or titratable acidity (TA). No grey mould development was observed on fruit at harvest when flowers were inoculated with a conidia suspension of B. cinerea (10⁴ conidia per mL). However, fruit harvested from plants that received calcium at any concentration had less incidence of grey mould during storage at 10⁰C, 90±5% RH for 14 days than fruit harvested from plants that received no calcium for both cultivars. For ‘Aromas’, 79% and 51% of fruit, and for ‘Selva’, 69% and 43% of fruit, showed rot when treated with 0 and 500 ppm Ca, respectively. The shelf life of ‘Aromas’ and ‘Selva’ increased by about 8% when plants received 500 ppm Ca in comparison with plants that received 0 ppm Ca. After 7 days of incubation at 22 to 24⁰C, there was no difference between blight lesions on wound-inoculated detached leaves from different calcium treatments for either cultivar. However, the lesions on ‘Selva’ were smaller than on ‘Aromas’. The calcium levels in leaves from plants that received calcium at any concentration were adequate for strawberry growing and significantly higher (P < 0.05) than in leaves from plants that received 0 ppm Ca. However, calcium treatment did not ensure transfer of calcium to fruit tissues. Calcium lactate and calcium chloride were used as postharvest calcium treatments at 1500, 3000 and 4500 ppm Ca. Fruit of ‘Selva’ were dipped in calcium solution for 5 min and wound-inoculated with B. cinerea (10⁶ conidia per mL). Calcium lactate and calcium chloride at 3000 and 4500 ppm Ca, respectively, were most effective in delaying Botrytis rot development on ‘Selva’ after 7 days of storage at 10⁰C, 90±5% RH. Storage for least 24 h after calcium dips prior to inoculation was required to delay the development of fruit rot. Fruit harvested early in the season seemed to be less susceptible to grey mould than those harvested later. However, calcium treatment tended to be more effective when applied to late-season fruit. Preharvest boron treatment, applied as for calcium but at 0, 0.25, 0.5 and 1.0 ppm B, had no effect on fruit firmness of either cultivar. However, firmness of ‘Aromas’ fruit was slightly greater than ‘Selva’ fruit for all treatments. The amount of boron applied had no effect on the external appearance, pH, SSC or TA for either cultivar after storage of fruit for up to 10 days. Application of boron had no effect on fruit grey mould development in either cultivar. Furthermore, boron had minimal effect on the incidence of blight on woundinoculated detached leaves of ‘Aromas’ 7 days after inoculation. However, blight lesion diameters on ‘Selva’ leaves in the 1.0 ppm B treatment (8.0 mm) were significantly smaller (P < 0.001) than in the 0 ppm B treatment (13.0 mm). Phytotoxicity was observed in boron treatments even at the level considered optimum for strawberry growing. Severity increased with increasing boron concentration but no consistent effect on flower death or flower abortion was observed. In conclusion, strawberry is sensitive to boron toxicity. Calcium may enhance fruit firmness and, consequently, delay grey mould development if calcium penetrates the fruit. Postharvest calcium treatment tended to be more effective in delaying development of grey mould when applied to late-season fruit. Calcium lactate is a potential alternative to calcium chloride for reducing decay caused by B. cinerea in strawberry without providing undesirable bitterness. This finding may provide a basis for application in industry. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1331382 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine 2008

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