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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.
21

Aloenxertos ósseos e enxerto sintético de hidroxiapatita em falha óssea ulnar em galinhas (Gallus gallus domesticus)

Schmitt, Bernardo January 2018 (has links)
A utilização de enxertos ósseos vem aumentando bastante em pequenos animais, entretanto, em aves esta utilização é menor devido à dificuldade de conseguir autoenxerto em quantidades adequadas. Sendo assim, o objetivo do projeto foi avaliar três tipos de enxertos em aves. Foram utilizadas 30 galinhas separadas em três grupos: grupo aloenxerto congelado em ultrafreezer (GUF) por duas semanas; grupo aloenxerto congelado em nitrogênio líquido (GNL) e grupo enxerto sintético de hidroxiapatita deficiente em cálcio (GHA). Os enxertos foram aplicados em defeito ósseo de aproximadamente 20mm na ulna das aves e fixados ao leito receptor com uma placa e quatro parafusos bloqueados. Os animais foram acompanhados por meio de avaliação clínica, radiográfica, histológica e biomecânica. A consolidação radiográfica ocorreu em 90% nos animais do GNL, 70% nos do GUF e 60% nos do GHA, com média de 47,14±13,50 dias no GUF, 61,67±21,79 dias no GNL e aos 70±18,17 dias no GHA, havendo diferença significativa entre o GUF e GHA. Histologicamente os enxertos do GUF apresentavam-se em processo de consolidação mais avançada, com remodelação óssea e a presença de osteoclastos. Na avaliação clínica todas as ulnas operadas tinham estabilidade, sem sinal de inflamação/contaminação, articulações preservadas, sem dor e sem desvios angulares graves na asa. Na análise biomecânica houve diferença significativa (p<0,05) entre o GNL e o GHA na resistência, já na avaliação de flexão máxima, observou-se diferença estatística entre o GHA e o GNL e entre o GHA e o GUF. Sendo assim, é possível concluir que os três enxertos testados podem ser utilizados em defeitos ósseos em aves, mas o melhor deles foi o GNL por apresentar mais vantagens na preparação, confecção, aplicação dos enxertos e resistência biomecânica, com maior taxa de consolidação óssea. / The use of bone grafts is increasing considerably in small animals, however, in poultry this use is less due to the difficulty of obtaining autograft in adequate quantities. Therefore, the objective of the project was to test three types of grafts, evaluating their best results over a period of 90 days. For this purpose, 30 chickens were divided into three groups: frozen ultra freezer allograft group (UFG) for two weeks; allograft frozen in liquid nitrogen group (LNG) and synthetic grafts of calcium deficient hydroxyapatite group (HAG). Grafts were applied to a bone defect of approximately 20 mm in the ulna of birds, in all three groups the grafts were fixed to the recipient bed with plates blocked and 4 screws locked. The animals were followed up by serial radiographs, histological examination, clinical orthopedic evaluation and biomechanical flexion assay. Radiographic consolidation occurred in 90% of the LNG, 70% in the GUF and 60% in the GHA, mean of 47.14 ± 13.50 days without UFG, 61.67 ± 21.79 days non LNG and at 70 ± 18.17 days without HAG, with a significant difference between UFG and HAG. Histologically, UFG grafts were in a more advanced consolidation process, presenting bone remodeling with a presence of osteoclasts In the clinical review, all of them were operated with stability, with no sign of inflammation / contamination, preserved joints, no pain and no angular deviations, graves in the nail. In the biomechanics, there was a significant difference (p <0.05) between LNG and HAG in the resistance, already in the evaluation of maximum flexion, it was observed statistical difference not HAG with LNG and HAG with UFG grafts. Thus, it is possible to conclude that the three grafts tested are feasible to be used in bone loss in birds, where the LNG was superior because it presented more advantages in the preparation, preparation and application of the grafts, presenting a higher rate of bone consolidation.
22

Aloenxertos ósseos e enxerto sintético de hidroxiapatita em falha óssea ulnar em galinhas (Gallus gallus domesticus)

Schmitt, Bernardo January 2018 (has links)
A utilização de enxertos ósseos vem aumentando bastante em pequenos animais, entretanto, em aves esta utilização é menor devido à dificuldade de conseguir autoenxerto em quantidades adequadas. Sendo assim, o objetivo do projeto foi avaliar três tipos de enxertos em aves. Foram utilizadas 30 galinhas separadas em três grupos: grupo aloenxerto congelado em ultrafreezer (GUF) por duas semanas; grupo aloenxerto congelado em nitrogênio líquido (GNL) e grupo enxerto sintético de hidroxiapatita deficiente em cálcio (GHA). Os enxertos foram aplicados em defeito ósseo de aproximadamente 20mm na ulna das aves e fixados ao leito receptor com uma placa e quatro parafusos bloqueados. Os animais foram acompanhados por meio de avaliação clínica, radiográfica, histológica e biomecânica. A consolidação radiográfica ocorreu em 90% nos animais do GNL, 70% nos do GUF e 60% nos do GHA, com média de 47,14±13,50 dias no GUF, 61,67±21,79 dias no GNL e aos 70±18,17 dias no GHA, havendo diferença significativa entre o GUF e GHA. Histologicamente os enxertos do GUF apresentavam-se em processo de consolidação mais avançada, com remodelação óssea e a presença de osteoclastos. Na avaliação clínica todas as ulnas operadas tinham estabilidade, sem sinal de inflamação/contaminação, articulações preservadas, sem dor e sem desvios angulares graves na asa. Na análise biomecânica houve diferença significativa (p<0,05) entre o GNL e o GHA na resistência, já na avaliação de flexão máxima, observou-se diferença estatística entre o GHA e o GNL e entre o GHA e o GUF. Sendo assim, é possível concluir que os três enxertos testados podem ser utilizados em defeitos ósseos em aves, mas o melhor deles foi o GNL por apresentar mais vantagens na preparação, confecção, aplicação dos enxertos e resistência biomecânica, com maior taxa de consolidação óssea. / The use of bone grafts is increasing considerably in small animals, however, in poultry this use is less due to the difficulty of obtaining autograft in adequate quantities. Therefore, the objective of the project was to test three types of grafts, evaluating their best results over a period of 90 days. For this purpose, 30 chickens were divided into three groups: frozen ultra freezer allograft group (UFG) for two weeks; allograft frozen in liquid nitrogen group (LNG) and synthetic grafts of calcium deficient hydroxyapatite group (HAG). Grafts were applied to a bone defect of approximately 20 mm in the ulna of birds, in all three groups the grafts were fixed to the recipient bed with plates blocked and 4 screws locked. The animals were followed up by serial radiographs, histological examination, clinical orthopedic evaluation and biomechanical flexion assay. Radiographic consolidation occurred in 90% of the LNG, 70% in the GUF and 60% in the GHA, mean of 47.14 ± 13.50 days without UFG, 61.67 ± 21.79 days non LNG and at 70 ± 18.17 days without HAG, with a significant difference between UFG and HAG. Histologically, UFG grafts were in a more advanced consolidation process, presenting bone remodeling with a presence of osteoclasts In the clinical review, all of them were operated with stability, with no sign of inflammation / contamination, preserved joints, no pain and no angular deviations, graves in the nail. In the biomechanics, there was a significant difference (p <0.05) between LNG and HAG in the resistance, already in the evaluation of maximum flexion, it was observed statistical difference not HAG with LNG and HAG with UFG grafts. Thus, it is possible to conclude that the three grafts tested are feasible to be used in bone loss in birds, where the LNG was superior because it presented more advantages in the preparation, preparation and application of the grafts, presenting a higher rate of bone consolidation.
23

Diagnostické metody solárních článků za velmi nízkých teplot / Diagnostic method of solar cells operating at very low temperatures

Bartoň, Jiří January 2011 (has links)
This work deals with the modern diagnostic methods of defects detection of solar cells. Defects are detected by electroluminescence and photoluminescence methods. The main focus of this work is an innovation workplace for measuring solar cell defects at very low temperatures using photoluminescence. Liquid nitrogen is used to cooling solar cells. By using low temperatures can be detection methods to obtain more objektive results of diagnostic defects.
24

A Data Acquisition System Experiment for Gas Temperature and Pressure Measurements on a Liquid-Nitrogen-Powered Vehicle

Lui, Samson Sze-Sang 05 1900 (has links)
A data acquisition system was set up to measure gas temperatures and pressures at various points on a liquid-nitrogen-powered vehicle. The experiment was attempted to develop a data acquisition method for applications on engines that use liquid air as the fuel. Two thermocouples and a pressure transducer were connected using data acquisition instruments interfaced to a laptop computer to acquire data.
25

ASSESSMENT OF GOVERNING HEAT AND MASS TRANSFER COEFFICIENTS FOR CRYOGENIC NO-VENT TOP-OFF MODELING

Ahlman, Robert 14 July 2021 (has links)
No description available.
26

Eiskalte Geschmacksexplosionen / Icecold Taste Explosions : Molecular Cooking at low Temperatures with Liquid Nitrogen and Dry Ice

Lang, Heinrich 06 July 2016 (has links) (PDF)
Chemiker sind Alchemisten, Köche Hexenmeister des Geschmacks. Beide Berufsgruppen haben sich in den vergangenen Jahren den Abenteuern des experimentellen Kochens bei sehr kalten Temperaturen verschrieben. Die Kombination von Chemie und Kochen bringt neue und spektakuläre kulinarische Kreationen hervor und schafft avantgardistische Gaumenverführungen mit verblüffenden Sinneserlebnissen und dies bei den sehr tiefen Temperaturen des flüssigen Stickstoffs (-196 °C) und des Trockeneises (-78.5 °C). Das Molekulare Kochen bei tiefen Temperaturen lebt von den spannungsgeladenen Gegensätzen von Wärme und Kälte und führt im Resultat zu neuartigen, bisher unbekannten Geschmackserlebnissen. Gleichzeitig wirkt die Molekulare Küche bei tiefen Temperaturen als Ideen- und Impulsgeber für innovative Speisen und Getränke und betritt dabei Neuland der Avantgarde-Küche, in der es dem sinnlichen Genuss eine neue, richtungsweisende Dimension verleiht. Dabei bedient sich das Molekulare Kochen mit flüssigem Stickstoff bzw. Trockeneis des Wissens um chemische und physikalische Prozesse. Dies macht die Molekularküche in der Kälte so spannend, denn sie bewegt sich damit auf dem Grenzgebiet der traditionellen Cuisine und den Wissensgebieten der Naturwissenschaften Chemie und Physik und führt zu einer gegenseitigen Wissensbereicherung in diesen Disziplinen. In diesem Buch wird der Autor, ein Chemiker, zum Grenzgänger seines Fachgebiets und verknüpft sein Wissen aus dem Chemielabor mit dem aus der Küche. Er schafft damit einen Ort für das Kochen mit Kälte und lässt Sie an außergewöhnlichen, unvergesslichen Geschmackserlebnissen sowie an chemischen und kulinarischen Augenfreuden teilhaben. Voraussetzung für ein erfolgreiches Kochen in der Kälte ist das Wissen um die Kältemittel wie dem flüssigen Stickstoff und dem Trockeneis. Deshalb befasst sich diese Schrift neben avantgardistischen Kochrezepten auch mit den beiden Kältemitteln, so dass beide Aspekte, nämlich die Chemie und die Küche, miteinander vereint werden. Basierend darauf, und gepaart mit diesen Erkenntnissen, werden innovative, „eiskalte“ Cocktails und Speisen vom Popcorn, über Bananasplit bis zu Espuma vorgestellt. Es handelt sich dabei um Speisen, die im Inneren flüssig bleiben, aber außen eine feste, krustige Hülle aufweisen, die beim Erwärmen im Mund zerplatzt, dabei kalte „Nebel“ bildet und sich so ein köstlicher Geschmack auf der Zunge ausbreitet. Ein unvergessliches Gaumen-Erlebnis! Des Weiteren werden einfache, aber spektakuläre und effektvolle chemische Experimente zu vereinzelten Kochrezepten rund um das Thema Molekulare Küche bei tiefen Temperaturen vorgestellt, die die Kochvorführungen bereichern und zeigen, dass die „Chemie“ zwischen Chemikern und Köchen stimmt. Die chemischen Vorgänge mit Reaktionsgleichungen zu den einzelnen Experimenten sind in Kapitel 4 dieser Schrift für Chemieinteressierte aufgeführt. In diesem Sinne wünscht der Autor beim Lesen, Experimentieren mit Flüssigstickstoff und Trockeneis, sowie beim Genießen der zubereiteten Köstlichkeiten viel Vergnügen und verspricht eine interessante Reise in die Molekulare Küche bei tiefen Temperaturen.
27

Attempts to promote the use of cryopreserved bovine semen: Effect of prostaglandin F2-alpha, sucrose and short-term dry ice storage

Abdussamad, Abdussamad Muhammad 30 October 2013 (has links)
No description available.
28

Investigation of novel cooling methods to enhance aerospace component manufacturing practices

Koen, Devan 12 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: The aerospace industry actively pursues innovation, especially in materials and their use in new applications, to improve their aircraft as well as their competitive position. Ti-6Al-4V has been available now for more than 50 years. Yet, in the new generation of aircraft using structural composites, a dramatic increase in the proportion of Ti-6Al-4V will be seen along with emerging application in automotive and chemical industries. This material possesses superior material properties compared to conventional materials such as steel and aluminium, although it is at the expense of machinability. Researchers are therefore actively searching for improved cutting technologies to improve production rates for Ti-6Al-4V. At higher cutting speeds than the industry norm of 60 - 90 m/min, machining becomes a challenge, resulting in low productivity on titanium parts. The limiting factor in the machining of Ti-6Al-4V is high tool temperatures of the order of 1000oC, caused by its resistance to absorb heat and good mechanical strength at elevated temperatures. The result is extreme temperatures that are concentrated on the cutting edge of the tool. The challenge to improve the tool life is therefore focused on removing heat from the insert. Liquid nitrogen was identified as a good candidate as coolant with the additional advantage of being environmentally friendly. The research presented investigates the use of a gravity feed enclosed liquid nitrogen cooling system to improve the tool life of the cutting inserts. The liquid nitrogen is contained on the insert rake face by means of a tool cap. To improve the effectiveness of the cooling method, a polycrystalline diamond (PCD) insert was used. This insert has a considerably higher thermal conductivity that aids in cooling the cutting edge. Tungsten carbide inserts are used for benchmark testing. The round tungsten carbide inserts with conventional cooling performed exceptionally well for machining titanium compared to square inserts, yielding exceptional tool life improvements while significantly increasing the material removal rate. Positive results were recorded with the liquid nitrogen cooling system when used with the polycrystalline diamond cutting insert. A number of far reaching performance issues are identified relating to the design of the tool cap that hindered clear scientific outputs. From a research perspective, the project makes a contribution to the knowledge base in this field. Additionally a new approach in cooling was investigated, resulting in clear indications of design changes required. / AFRIKAANSE OPSOMMING: Die lugvaart industrie streef aktief innovasie na, veral op die gebied van materiale en hul gebruike, om hul vliegtuie en kompeterende posisie in die mark te verbeter. Ti-6Al-4V is al vir meer as 50 jaar beskikbaar. ‘n Drastiese verhoging in die aanvraag na Ti-6Al-4V deur die lugvaart, motor en chemiese industrieë word verwag wanneer die volgende geslag vliegtuie wat koolstofvesel as strukturele materiaal begin gebruik, in produksie gaan. Die materiaal het beter materiaaleienskappe as konvensionele materiale soos staal en aluminium, maar dit kom egter teen die prys van masjieneerbaarheid. Ti-6Al-4V se masjienering bo die industrie norm van 60 – 90m/min is ‘n groot uitdaging. Navorsers soek daarom deurentyd na verbeterde sny tegnologieë om die produksie tempo van Ti-6Al-4V te verbeter. Die beperkende faktor vir Ti-6Al-4V masjienering is die temperatuur wat genereer word. Die weerstand van die materiaal om hitte te absorbeer en sy goeie meganiese eienskappe veroorsaak dat temperature in die beitel 1000oC bereik. Hierdie temperature word egter op die snykant van die beitel gekonsentreer. Die uitdaging is dus om hierdie temperature in die beitel te beheer. Vloeibare stikstof is geïdentifiseer as ‘n goeie kandidaat vir verkoeling met die bykomende voordeel dat dit omgewingsvriendelik is. Die navorsing wat hier uiteengesit word, ondersoek die gebruik van ‘n geslote kamer beitelverkoelingstelsel wat deur gravitasie met vloeibare stikstof voorsien word om die beitel leeftyd te verbeter. Die oppervlak van die beitel word in hierdie konsep direk aan die vloeibare stikstof blootgestel. Om die effektiwiteit van die stelsel te verbeter word van PCD beitels gebruik gemaak. Die beitel se verbeterde hittegeleidingsvermoë help om die beitel se snykant koel te hou. Tungstenkarbied beitels word gebruik om ‘n standaard te stel vir eksperimentele analise. Die ronde tungstenkarbied beitels en konvensionele verkoeling het verstommend goed presteer vir Ti-6A-4V masjienering in vergelyking met vierkantige beitels. Die materiaalverwyderingstempo is aansienlik verhoog sonder om die beitel se leeftyd in te boet. Positiewe resultate is waargeneem met die vloeibare stikstof sisteem saam met die PCD beitels. ‘n Aantal verreikende uitdagings is geïdentifiseer wat suiwer wetenskaplike afleidings bemoeilik. Hierdie probleme kan almal aan die ontwerp van die toerusting toegeskryf word. Die werk lewer egter steeds ‘n bydrae tot die kennis in die veld. ‘n Bykomende benadering vir verkoeling is ondersoek wat duidelik ontwerp-veranderings aandui.
29

Småskalig släckning av konstruktionsbränder

Paulusson, Herman, Larsson, Caroline January 2018 (has links)
Konstruktionsbränder kan idag orsaka stora problem för räddningstjänsten. Släckningsarbeten vid konstruktionsbränder brukar idag involvera släckmedel som bygger på vattenbaserade medel. Detta medför att primära skador kan begränsas, men istället uppstår problemet med sekundära skador som mögel eller vattenskador. Idag finns det flertalet släckmedel som används men det finns inga dokumenterade tillfällen där flytande kväve och/eller koldioxid används vid konstruktionsbränder. Branschen har istället funnit användningsområden för flytande kväve vid gruvbränder med flertalet lyckade insatser. Flytande kväve och koldioxidsläckare är båda kylande släckmedel som vid användning uppnår mycket låga temperaturer. Släckmedlen släcker på liknande sätt, båda kyler till en viss del, men den primära släckkällan är kvävning. Flytande kväve får en avsevärd volymutveckling vid fasövergång från flytande till gas. Gasen tränger undan syret i den brandhärjade konstruktionen och kan därmed släcka branden. Koldioxid verkar på samma sätt, kvävande, men i detta fall övergår den kondenserade gasen till fast fas (torr-is) vid aktivering som sedan sublimerar till gas och kväver branden. För att undersöka släckmedlens förmåga att bekämpa konstruktionsbränder samt återantändningsskyddet vid användning, har åtta konstruktioner byggts. De fristående konstruktionerna ska efterlikna ett regelfack från en väggkonstruktion. Vid försöken har fyra konstruktioner använts till att undersöka flytande kväve och fyra konstruktioner för att undersöka koldioxid. Av dessa åtta användes två som testkonstruktioner i syftet att bestämma metod för applicering av släckmedel och anläggning av brand i konstruktionen. För att anlägga en brand i konstruktionerna antändes de i det nedre högra hörnet med hjälp av en propanbrännare. Vid fyra försök applicerades släckmedlen i mitten av konstruktionen i ett hål som borrats för att nå innandömet. Vid de andra två konstruktionerna applicerades släckmedlen vid hålet där branden anlades. För att mäta de temperaturer som uppstod i konstruktionerna placerades fem termoelement i varje konstruktion. I de tre försök där flytande kväve applicerades sjönk temperaturen drastiskt och efter en timme, när försöken avslutades, registrerade inget termoelement temperaturer höga nog för att en återantändning skulle kunna ske. I de tre försök där koldioxid applicerades släcktes två av tre konstruktioner och den tredje återantändes. Fem av sex försök uppvisades en trend där temperaturen låg mellan 12 – 56 °C när försöken avslutades och där temperaturen fortfarande sjönk. En trend påvisades för bägge släckmedlen, där de dröjde kvar i konstruktionen när försöken avslutades, efter cirka en timme. Släckmedlen kunde därmed under en lång tid förångas och påverka den brandhärjade konstruktionen och motverka återantändning. Slutsatsen av detta projekt är att flytande kväve och koldioxid verkar lovande som släckmedel vid konstruktionsbränder. Fler försök bör dock utföras för att styrka resultatet innan ett välgrundat uttalande kan göras. / Today structural fires can cause big problems for the rescue services. Extinguishing structural fires usually depends on methods involving water based extinguishers. These methods entails that the primary damages can be limited although secondary damages like mold or water damage may arise. Today there are several fire extinguishers that are used in the industry but few documented occasions have been found where liquid nitrogen or carbon dioxide is used on structural fires. Liquid nitrogen has long been used for mining fires with success. What liquid nitrogen and carbon dioxide in extinguishers have in common is that they are both cooling agents which upon activation reach very low temperatures. These extinguishing agents both put out a fire in a similar way, they both chill when applied, but that is not the primary source. The primary source of extinguishing comes by suffocating the fire by removing all the surrounding oxygen. The volumetric growth of gas between phase transitions displaces the oxygen present in the fire ravaged construction and thereby extinguishes the fire. Eight constructions were built to test these extinguishing agents and their potential for extinguishing construction fires. The purpose of these constructions was to simulate one part of an entire wall. To perform these tests, four out of the eight constructions were used to examine liquid nitrogen and the other four were used for carbon dioxide fire extinguishers. Two constructions were used as test constructions with the purpose to test different methods for the extinguishing agents as well as setting fire to the construction. A propane burner was used in the lower right corner of the construction to ignite it. The extinguishing agents were applied to the center of the constructions in four tests. In two tests the extinguishing agents were directed at the base of the fire in the lower right corner. A total of thirty thermocouples were used, divided evenly among the six tests that recorded data, with five thermocouples being placed in each construction. In the three tests with liquid nitrogen as extinguishing agent, the temperature dropped drastically. The temperatures registered in the wall by the thermocouples were not high enough to pose any risks for a fire to resurface at the end of the tests. In the tests using carbon dioxide as an extinguishing agent the fire managed to resurface in one out of three tests. In five out of six tests the thermocouples registered temperatures in the range of 12 – 56 °C and continually declining. Both of the extinguishers displayed similar behavior when observed, namely that the extinguishing medias could be observed remaining in the constructions long after the tests ended. This means that the extinguishing agents could evaporate during an extended period of time and counteract any flames from resurfacing. To conclude this report, the good qualities these extinguisher agents exhibit implies that they work well as extinguishing agents to combat construction fires. More experiments should be performed to strengthen the results from this project.
30

Conservação in vitro de morangueiro via crescimento lento e criopreservação / In vitro conservation of strawberry via slow growth and cryopreservation

Ferreira, Liana Viviam, Ferreira, Liana Viviam 30 June 2017 (has links)
Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2018-06-11T14:24:03Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) resumo_tese_liana_viviam_ferreira.pdf: 24128 bytes, checksum: a7df3cf5619315eeca9e1e6cdb36bfa8 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-06-11T16:56:28Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) resumo_tese_liana_viviam_ferreira.pdf: 24128 bytes, checksum: a7df3cf5619315eeca9e1e6cdb36bfa8 (MD5) / Made available in DSpace on 2018-06-11T16:56:28Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) resumo_tese_liana_viviam_ferreira.pdf: 24128 bytes, checksum: a7df3cf5619315eeca9e1e6cdb36bfa8 (MD5) Previous issue date: 2017-06-30 / Sem bolsa / A conservação in vitro proporciona opções de armazenamento a curto e médio prazo mediante a redução do metabolismo da planta (chamado crescimento lento) ou a longo prazo pela inibição das reações metabólicas (chamado criopreservação) ao qual, ambos aumentam ao máximo o intervalo entre os subcultivos, evitando a variação somaclonal, como ocorre no morangueiro após sucessivos subcultivos. Neste contexto, avaliou-se o efeito de diferentes reguladores osmóticos, temperaturas, tipos de explante e períodos de avaliação na conservação in vitro de morangueiro ‘Benícia’ via crescimento lento e a adaptação de protocolos de criopreservação por diferentes métodos em diferentes cultivares. Foram utilizados explantes oriundos de plantas de morangueiro ‘Benícia’ pré-estabelecidos in vitro e mantidos em meio MS de multiplicação. O meio usado nos experimentos foi o MS básico suplementado com 20g L-1 ou 40g L-1 de manitol ou sorbitol. No tratamento controle não houve adição de regulador osmótico. Dois tipos de explantes foram inoculados nos meios: explante somente com a parte aérea formada (PA) e planta inteira (PI), mantidos por 6 meses a 24±2°C em sala de crescimento e 12 meses em B.O.D com temperatura de 4±2°C, ambos com fotoperíodo de 16 horas e intensidade luminosa de 45-55μmol m-2 s-1. O delineamento experimental foi inteiramente casualizado em esquema fatorial 5x2x5 (meio de cultura, tipo de explante e períodos de avaliação), com três repetições de 10 explantes, totalizando 30 explantes por tratamento. Parâmetros de crescimento, bioquímicos e fisiológicos foram avaliados. De acordo com os resultados obtidos pode-se concluir que a temperatura de 4°C, a planta inteira e o uso do sorbitol proporcionam redução do crescimento de explantes de morangueiro ‘Benicia’ durante 12 meses de conservação in vitro sem afetar os parâmetros de crescimento, fisiológicos e bioquímicos da espécie. Em todos os protocolos testados de criopreservação as gemas de morangueiro não sobreviveram ao nitrogênio líquido, porém foi significativa a temperatura de 4°C durante o período de pré-aclimatação por 2-8 semanas. A solução de sacarose a 0,75M ocasionou maior taxa de sobrevivência. Os tempos de dessecação não foram eficientes e o uso da prolina aumentou a tolerância das gemas a desseção. / In vitro conservation provides short and medium term storage options by reducing plant metabolism (called slow growth) or long-term inhibition of metabolic reactions (called cryopreservation), both of which maximize the interval between subcultures, avoiding the somaclonal variation, as occurs in the strawberry after successive subcultures. In this context, the effect of different osmotic regulators, temperatures, explant types and evaluation periods on the in vitro conservation of 'Benicia' strawberry by slow growth and the adaptation of cryopreservation protocols by different methods in different cultivars were evaluated. Explants from 'Benicia' strawberry plants were used in vitro and maintained in MS medium of multiplication. The medium used in the experiments was the basic MS supplemented with 20g L-1 or 40g L-1 of mannitol or sorbitol. In the control treatment there was no addition of osmotic regulator. Two types of explants were inoculated in the media: explant only with aerial part (PA) and whole plant (PI), maintained for 6 months at 24±2°C in growth room and 12 months in BOD with temperature of 4±2°C, both with photoperiod of 16 hours and luminous intensity of 45-55 μmol m-2 s-1. The experimental design was completely randomized in a 5x2x5 factorial scheme (culture medium, explant type and evaluation periods), with three replicates of 10 explants, totaling 30 explants per treatment. Growth parameters, biochemical and physiological parameters were evaluated. According to the results obtained, it can be concluded that the temperature of 4°C, the whole plant and the use of sorbitol provide a reduction in the growth of 'Benicia' strawberry explants during 12 months of in vitro conservation without affecting growth parameters, physiological and biochemical characteristics of the species. In all tested cryopreservation protocols the strawberry buds did not survive liquid nitrogen, but the temperature of 4°C during the preacclimation period for 2-8 weeks was significant. The sucrose solution at 0.75M resulted in a higher survival rate. The desiccation times were not efficient and the use of proline increased the tolerance of the egg yolks.

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