Perennial growers overwintering plant stock require information to assist in deciding which containerized plants are most likely to successfully overwinter. Three studies on container-grown herbaceous perennials were conducted to examine the influence of plant age, soil moisture, and temperature cycling date on cold hardiness. In January, plants were exposed to controlled freezing temperatures of -2, -5, -8, -11, and -14C and then returned to a 3-5C greenhouse. In June, plants were assessed using a visual rating scale of 1-5 (1 = dead, 3-5 = increasing salable quality, varying by cultivar) and dry weights of new growth were determined. Controlled freezing in November and March were also included in the third study. In the first study, two ages of plants were exposed to controlled freezing temperatures in January. For Geranium x cantabrigiense 'Karmina', age had no effect on either rating or dry weight in one study year. In two Sedum 'Matrona' study years, age had no effect on dry weight but ratings were higher for older plants than younger plants in the first year and higher for younger plants than older plants in the second year. In two Leucanthemum x superbum 'Becky' study years, age had an effect on both rating and dry weight which were both generally higher for younger plants than older plants. In the second study, plants were maintained in pots at two different soil moisture levels prior to exposure to controlled freezing temperatures in January. Coreopsis 'Tequila Sunrise' and Carex morrowii 'Ice Dance' showed no effect on either rating or dry weight from soil moisture level. Soil moisture level had no effect on dry weight but ratings were higher for Geranium x cantabrigiense 'Cambridge' “wet” plants and for Heuchera 'Plum Pudding' “dry” plants. Carex laxiculmus 'Hobb' (Bunny Blue™) soil moisture level had an effect where dry weight was higher for “dry” plants. Means at were of salable quality for Geranium and Heuchera at all temperatures and Carex laxiculmus at temperatures above -11C. The effects of soil moisture level on Carex oshimensis were inconclusive. In the third study, during November, January, and March, plants were subjected to temperature cycling treatments prior to exposure to controlled freezing temperatures. Geranium x cantabrigiense 'Cambridge' were more tolerant of both temperature cycling and freezing temperatures in January and an increased number of cycles in November had an advantageous effect. Sedum 'Matrona' were more tolerant of temperature cycling and freezing temperatures in January and an increased number of cycles in March had an advantageous effect. Leucanthemum x superbum 'Becky' were more tolerant of temperature cycling in January in the second year of the study and an increased number of cycles in November had an advantageous effect in the first year and in all months in the second year. Overwintering younger container-grown plants is likely to result in more growth and higher quality following exposure to freezing temperatures. Effects of soil moisture level on overwintering container-grown plant growth and quality are cultivar-specific and a general effect could not be established in these studies. Overwintering container-grown plants are likely to be hardier in January and slight temperature cycles prior to exposure to freezing temperatures generally increase hardiness.

Regenerative medicine is an emerging technology and with hundreds of cell therapies currently in clinical trials there is a need to expand the limited knowledge related to their storage, shipment and preservation. The most widely used medium for human cell cryopreservation is 10%wt dimethyl sulfoxide (DMSO) in serum. However given its potential toxicity, DMSO usage is a key issue in cryopreservation. Methods specify the need to reduce cell exposure time to DMSO above 0°C as much as possible but the maximum amount of time cells can be exposed to DMSO to prevent a detrimental effect needs to be clarified. There are also regulatory issues and concerns with the xenotoxicity, ethics and supply of the other core component in the standard cryomedia formulation: Foetal Bovine Serum (FBS). Developing a viable alternative to FBS is crucial. In cryobiology literature thawing appears poorly understood. A stable process is as vital as freezing to prevent injury to cells. Protocols are currently too vague for cell therapy regulation and need improvement. The time dependent DMSO cytotoxicity was evaluated by overexposing cells to DMSO during and/or after cryopreservation. A broad investigation found that after 1 hour overexposure post thaw viability of human mesenchymal stem cells (hMSCs) was reduced from 96.3±0.6% to 74.1±4.0% and the co-expression of five key hMSC markers was changed from 97.9±1.3% to 68.3±2.6%. This significant change could cause indicate a change in product efficacy and affect patient health, to prevent this, DMSO exposure must be kept to below 1 hour. A range of alternative vehicle solutions were screened and human platelet lysate (hPL) investigated as an alternative. In depth experimentation with hPL as a cryopreservation vehicle solution and culture supplement (in place of FBS) found it to be a worthy, statistically similar alternative. With no xenological or ethical concerns, lower costs than other serum-free alternatives hPL could allow for a move away from xenological components. A heat transfer model was developed and determined that 720J is required to thaw a vial. Using the heat transfer model and additional factors such as pre-thaw stabilisation and on thaw dilution, a two-stage experiment found that the current standard process (warming in a 37°C waterbath) within the current paradigm of a 1.8mL cryovial is optimal but further work is required to define the process for scaled-up product.

Sistemas de liberação controlada vêm sendo cada vez mais utilizados em diferentes áreas tendo em vista sua aplicabilidade que os tornam uma tecnologia capaz de atender as necessidades econômicas e ambientais uma vez que permitem a utilização de princípios ativos em quantidades precisas e apenas nos locais desejados. Dentre a diversidade de opções de matrizes utilizadas nesses sistemas o poli(álcool vinílico) tem sido bastante empregado e pode ser obtido pela técnica de ciclos térmicos. Azadiractina, um princípio ativo encontrado em óleo de semente de Nim tem sido descrita como repelente de diferentes tipos de insetos e apresenta grande aplicabilidade na agricultura. Com base nas propriedades desse composto, propôs-se o desenvolvimento de um sistema de liberação controlada para combate a pulgas Ctenocephalides felis felis. No presente trabalho, foram realizadas caracterizações físico-químicas das matrizes e dispositivos através de ensaios de fração gel, intumescimento, calorimetria exploratória diferencial e microscopia eletrônica de varredura e caracterizações biológicas quanto à citotoxicidade do óleo de Nim, matrizes e dispositivos e bioensaio para análise do comportamento das pulgas na presença do óleo de Nim. As caracterizações físico-químicas permitiram a escolha da matriz mais adequada para o desenvolvimento do dispositivo. As caracterizações biológicas demonstraram ausência de citotoxicidade do óleo de Nim, das matrizes e dos dispositivos e o bioensaio resultou em 40% de mortalidade das pulgas testadas. Na cinética de liberação, verificou-se que todos os agentes encapsulantes utilizados permitiram a liberação de princípios ativos do óleo de Nim. / Controlled release systems has been increasingly used into different purposes due to its applicability that turns it onto a technology able to supply economic and environmental needs, once thats allows using precise amounts of active ingredients and only on aimed locations. Among the variety of matrix options used in this systems, poly (vinyl alcohol) has been larged employed and can be obtained by thermal cycles technics. Azadirachtin, an active ingredient found in Neem seed oil has been described as a repellent of different kinds of insects and has great agriculture\'s applicability. Based on compound properties, was proposed to develop a controlled release system to combat flea Ctenocephalides felis felis. In the present study was performed physicochemical characterizations of matrix and devices through gel fraction, swelling tests, differential scanning calorimetry, scanning electron microscopy and biological characterizations by cytotoxicity assay of Neen\'s oil, matrix and devices and analysis of flea\'s behavior at neem\'s oil presence by bioassay. The physical-chemical characterizations has enabled to choose the most suitable matrix to device\'s development. The biological characterizations has been demonstrated absence of oil\'s cytotoxicity, matrices and devices and bioassay has resulted in 40% mortality of fleas. On kinetic\'s release, was cheked that all used encapsulating agents has allowed the release neem\'s oil active principles.

Sistemas de liberação controlada vêm sendo cada vez mais utilizados em diferentes áreas tendo em vista sua aplicabilidade que os tornam uma tecnologia capaz de atender as necessidades econômicas e ambientais uma vez que permitem a utilização de princípios ativos em quantidades precisas e apenas nos locais desejados. Dentre a diversidade de opções de matrizes utilizadas nesses sistemas o poli(álcool vinílico) tem sido bastante empregado e pode ser obtido pela técnica de ciclos térmicos. Azadiractina, um princípio ativo encontrado em óleo de semente de Nim tem sido descrita como repelente de diferentes tipos de insetos e apresenta grande aplicabilidade na agricultura. Com base nas propriedades desse composto, propôs-se o desenvolvimento de um sistema de liberação controlada para combate a pulgas Ctenocephalides felis felis. No presente trabalho, foram realizadas caracterizações físico-químicas das matrizes e dispositivos através de ensaios de fração gel, intumescimento, calorimetria exploratória diferencial e microscopia eletrônica de varredura e caracterizações biológicas quanto à citotoxicidade do óleo de Nim, matrizes e dispositivos e bioensaio para análise do comportamento das pulgas na presença do óleo de Nim. As caracterizações físico-químicas permitiram a escolha da matriz mais adequada para o desenvolvimento do dispositivo. As caracterizações biológicas demonstraram ausência de citotoxicidade do óleo de Nim, das matrizes e dos dispositivos e o bioensaio resultou em 40% de mortalidade das pulgas testadas. Na cinética de liberação, verificou-se que todos os agentes encapsulantes utilizados permitiram a liberação de princípios ativos do óleo de Nim. / Controlled release systems has been increasingly used into different purposes due to its applicability that turns it onto a technology able to supply economic and environmental needs, once thats allows using precise amounts of active ingredients and only on aimed locations. Among the variety of matrix options used in this systems, poly (vinyl alcohol) has been larged employed and can be obtained by thermal cycles technics. Azadirachtin, an active ingredient found in Neem seed oil has been described as a repellent of different kinds of insects and has great agriculture\'s applicability. Based on compound properties, was proposed to develop a controlled release system to combat flea Ctenocephalides felis felis. In the present study was performed physicochemical characterizations of matrix and devices through gel fraction, swelling tests, differential scanning calorimetry, scanning electron microscopy and biological characterizations by cytotoxicity assay of Neen\'s oil, matrix and devices and analysis of flea\'s behavior at neem\'s oil presence by bioassay. The physical-chemical characterizations has enabled to choose the most suitable matrix to device\'s development. The biological characterizations has been demonstrated absence of oil\'s cytotoxicity, matrices and devices and bioassay has resulted in 40% mortality of fleas. On kinetic\'s release, was cheked that all used encapsulating agents has allowed the release neem\'s oil active principles.

O pão produzido de massa congelada tem sido aprimorado pelos avanços tecnológicos e diferentes formulações, porém ainda apresenta problemas como fermentação prolongada, baixo volume, textura e desempenho variados. O efeito do congelamento pode ser minimizado através do uso de aditivos e ingredientes adequados para a elaboração da massa. Entretanto o mecanismo de fortalecimento devido aos aditivos como, por exemplo, o emulsificante não é completamente conhecido. A análise térmica é uma ferramenta útil para pesquisa, desenvolvimento e controle de qualidade de alimentos, pois permite o estudo das alterações na sua estrutura durante um tratamento térmico. O objetivo do trabalho foi estudar a influência do uso de aditivos de panificação sobre o comportamento da massa de pão francês após ciclos de congelamento e descongelamento. O trabalho experimental foi dividido em quatro etapas: na primeira, diferentes formulações foram produzidas com os componentes estearoil-2-lactil lactato de cálcio (CSL), polisorbato 80 (PS80) e gordura vegetal hidrogenada (GVH); na segunda etapa foi realizado um projeto de mistura com três componentes (CSL, PS80 e ésteres de ácido diacetil tartárico de mono e diglicerídio - DATEM); na terceira foi estudada a influência do ácido ascórbico sobre as características reológicas e os eventos determinados através de Calorimetria Exploratória Diferencial (DSC) afim de otimizar o uso destes aditivos em massas congeladas. A análise térmica mostrou-se adequada aos eventos de congelamento e descongelamento, porém não em relação aos eventos relativos aos aquecimentos. A resistência à extensão bem como a extensibilidade da massa foram influenciadas pelo tempo de armazenamento congelado. Na quarta etapa do projeto, foram produzidos pães franceses à partir de massas com a mistura (0,3 % de PS80 e 0,2 % de DATEM sobre a farinha de trigo) e dois níveis de ácido ascórbico (0 e 200 ppm). Volume específico, perfil de textura, conteúdo de água e medida da produção de gás e tolerância da massa durante a fermentação foram determinados. Os pães produzidos com a adição de ácido ascórbico apresentaram maiores volumes específicos e menores valores para os parâmetros de textura dos pães (firmeza, elasticidade, coesividade e mastigabilidade). / Bread produced from frozen dough has been improved due to technological advances and formulation, however it still presents problems like long proofing, low specific volume, varied texture and performance. The effect of freezing can be minimized by use of additives and adequate ingredients. The mechanism of dough strengthening due to use of additives, such as emulsifiers, is not fully understood. Thermal analysis is a useful tool for food research, development and quality control, because it provides information on food structural changes during thermal treatment. The goal of this research is to study the influence of additives in bread making on French bread dough after a freeze-thaw cycles. The experimental part consists of four parts: in the first, different formulations were produced with the components calcium stearoyl-2-lactylate (CSL), polysorbate 80 (PS80) and vegetable shortening (VGH); in the second, a mixture design with three components (CSL, PS80 and diacetyl tartaric esters of mono and digliceride – DATEM) was made; in the third, influence of ascorbic acid was studied on rheological measurement and events determined by differential scanning calorimetry (DSC) to optimize the use of additives on frozen dough. Thermal analysis was adequate for the freeze-thaw events, however not for the heating events. Resistance to extension and dough extensibility were influenced by storage time. In the fourth part, French breads from frozen dough were produced with the mixture (0,3 % of PS80 and 0,2 % of DATEM in flour basis) and two levels of ascorbic acid. Specific volume, texture profile, water content, gas production and mass tolerance during proofing were determined. Breads made with ascorbic acid addition presented a higher specific volume and lower values for texture profile (firmness, springiness, cohesiveness and chewiness).

Este estudo investiga o Módulo de Young (Módulo de Elasticidade) em amostras de osso cortical oriundas de uma mesma região da tíbia bovina depois de submetidas a congelamentos e descongelamentos sucessivos. As amostras foram coletadas da face caudal do terço médio da diáfise de tíbias bovinas e depois submetidas a testes de flexão em três pontos e ensaios de ruptura, obedecendo à norma ASTMD790M86ε1. Nesse experimento, 20 pares de amostras de ossos corticais foram retirados de 20 tíbias bovinas, cada amostra medindo 2 mm x 4 mm x 40 mm, aproximadamente. Todos os testes foram realizados à temperatura controlada (21 graus Celsius), e as condições de ensaio foram as mesmas durante os testes. As amostras foram identificadas e divididas em dois grupos experimentais: Grupo A: as amostras foram conservadas (em sacos plásticos) a - 20 graus Celsius (submetidos a congelamentos e descongelamentos sucessivos por 50 vezes: uma vez ao dia durante 50 dias). Esses descongelamentos produziram 15 ensaios de flexão, sendo que o primeiro foi realizado com as amostras ainda frescas mantidas em geladeira a 4 graus Celsius. Após os 50 descongelamentos foram levados até a ruptura. Grupo B: as amostras foram conservadas frescas (em sacos plásticos) a 4 graus Celsius em geladeira aguardando o tempo para que os ensaios do grupo A fossem concluídos e, posteriormente fez-se o teste de ruptura. Importantes cuidados foram tomados. Depois de cada descongelamento, as amostras foram analisadas e comparadas com as amostras frescas tanto para os ensaios de flexão em três pontos como para os ensaios de ruptura. Observamos que o congelamento não alterou de modo significativo as propriedades mecânicas destes ossos, pois não foi encontrada nenhuma diferença significativa entre o comportamento dos dois grupos testados. Isso implica que, congelando e estocando mesmo por longos períodos, as propriedades mecânicas não se alteram tanto nos ensaios de flexão em três pontos como nos ensaios de ruptura. Com respeito às diferenças observadas no dia a dia, as alterações do primeiro dia até o último dia não foram significativas / The present study was conducted to investigate the Young Module (Elasticity Module) in cortical bone samples submitted to successive freezing and thawing and then assayed in flexion tests at three points and in rupture tests according to the norms of ASTMD790M86ε1. Twenty pairs of cortical bone samples, each measuring approximately 2 x 4 x 40 mm, were collected from the same region of the caudal surface of the middle third of the diaphysis of 20 bovine tibiae and divided into two experimental groups: Group A: consisting of 20 cortical bone samples stored at – 20 Celsius degrees in plastic bags and submitted to successive freezing and thawing 50 times once a day for 50 days. These thawing episodes produced 15 flexion assays. After the 50 thawing episodes, the samples were tested until rupture. Group B: consisting of 20 cortical bone samples stored at 4 Celsius degrees in plastic bags in a refrigerator until the time when the assays of group A were concluded and then submitted to the rupture test. No statistically significant variation in the Young Module was observed after the flexion test at three points performed for Group A. The values of rupture tension also did not differ significantly between groups A and B. We observed that freezing did not cause a significant change in the mechanical properties of these bones, indicating that freezing and storage of these bones even for long periods of time does not alter their mechanical properties in flexion tests at three points or in rupture assays

It is surprising to know the small amount of work that has been done on alternate freezing and thawing of seeds. Many experiments, however, have been conducted to see the effect of very low temperatures on seeds and to notice the effect it had on their vitality. Some experimenters subjected seeds to temperatures as low as liquid hydrogen with very interesting results but in very few cases, if any, was the effect of alternate freezing and thawing studied. The work that follows deals directly with the effects of alternate freezing and thawing on impermeable seeds of alfalfa and of dodder. It is known that this seed does not germinate readily; therefore it often lays over winter in the soil. Does this natural freezing and thawing aid or hinder this impermeable seed in it's later germination? this has been the main question kept in mind throughout this experiment.

<p>There is consistent research evidence that shows improvement of the engineering properties of subgrade soils treated with lime or cement. However, limited information is available on the effect of climatic changes on the subgrade stiffness. The thesis studies the effects of changes in soil moisture content and temperature on the resilient modulus of treated and untreated subgrades in Indiana. Two types of soils were tested: A-6 and A-7-6, from two locations in Indiana: Hartford City and Bloomington, respectively. When existing standards ASTM D559/559-15 and ASTM D560/560-16 for wetting/drying (WD) and freezing/thawing (FT) processes, respectively, were followed, the treated and untreated samples failed through the process of preparation due to the stringent procedures in the standards. Appropriate test conditions were investigated, as part of the research, to develop new protocols more appropriate to the field conditions in Indiana. Two new test protocols were developed and successfully applied to the treated soils. A total of 26 resilient modulus, M_R, tests were conducted following the standard AASHTO T307-99. The M_R results showed that the repeated action of WD and FT cycles reduced the stiffness of the chemically-treated soils down to values similar to or lower than those of the untreated soils. However, when the amount of chemical was doubled, with respect to the optimum, the M_R of the treated soils improved over that of the untreated soils, even after the wetting-drying cycles.</p>

Darbo uždaviniai: 1. nustatyti triušienos svorio sumažėjimą priklausomai nuo atšildymo metodo; 2. nustatyti cheminių savybių pokyčius, kai ji atšildoma mikrobangų krosnelėje ir aplinkos ore; 3. nustatyti mėsos pH, spalvos intensyvumą, vandens rišlumo gebą, vandens išlašėjimo nuostolius ir virimo nuostolius; 4. nustatyti giliai sušaldytos triušienos laikymo trukmės ir atšildymo metodo poveikį juslinėms savybėms ir bendram bakterijų skaičiui. 5. atlikti gautų rezultatų statistinę analizę. Tyrimo metodika ir organizavimas. Tiriamasis darbas buvo atliktas Lietuvos sveikatos mokslų universitete, Veterinarijos akademijoje, Gyvūnų mitybos katedroje, Olštyno Varmijos – Mazūrų universitete Gyvūnų bioinžnerijos fakultete Rinkodaros ir gyvūninių žaliavų vertinimo katedroje. Tyrimai atlikti su triušiais mišrūnais, kurie gauti sukryžminus Naujosios Zelandijos triušių veislę su Kalifornijos triušių veisle. Analogų principų atrinkti 35 mišrūnai triušiai, kurie buvo laikomi vielos tinklo narveliuose po keturis, šeriami ad Libitum visaverčiais kombinuotaisiais pašarais. Triušai buvo skerdžiami pasiekus 3,2 kg kūno svorį (lyčių santykis 1:1) Visi mėginiai m. longissimus dorsi buvo supakuoti į PE-HD foliją, tuomet 28 jų buvo sušaldyti Bosch šaldiklyje (-28°C, 40% santykinė drėgmė), o likę 7 saugomi 4°C temperatūroje 24 valandas iki analizės. Praėjus 48 val. po triušių paskerdimo m. longissimus mėginiuose nustatyti mėsos fiziniai ir cheminiai rodikliai. Sušaldyti triušienos mėginiai po 2... [toliau žr. visą tekstą] / The tasks of the experiment: 1. Identify rabbit weight loss by using defrosting microwave oven and ambient atmospheric air; 2. Determine the changes of chemical properties when it should be thawed in a microwave oven or in the air; 3. To determine the acidity of the meat after thawing; 4. Identify the color intensity water-holding capacity, drip loss, thermal loss; 5. Set deep frozen rabbit meat storage time and thawing method on the sensory properties and total bacterial count. 6. To carry out a statistical analysis of the results obtained. Materials and methods. Research work was performed at Lithuanian University of Health Sciences, Veterinary Academy, Department of Animal Husbandry Technology, in the Vivarium of the Veterinary Academy and at the University of Warmia and Mazury in Olsztyn, the Faculty of Animal Bioengineering. The research was done with rabbits Hybrids - the crossing of the New Zealand rabbit breed to breed rabbits of California. Read-selected 35 crossbred rabbits that were kept in wire mesh cages, four, fed ad libitum, wholesome compound feed. Rabbits were slaughtered after they reached 3.2 kg body weight (sex ratio 1:1). All then samples of m. longissimus dorsi were packaged in HD-PE foil, and 28 of them were deep-frozen in the Bosch freezer, while the remaining 7 were stored at 4°C for 24 hours, until analyses. After 3 months of storage, deep-frozen samples were thawed in a microwave oven and in the atmospheric air. M. Longissimus dorsi samples as... [to full text]

Diss. (sammanfattning) Swedish University of Agricultural Sciences : Sveriges lantbruksuniv., 2006. / Härtill 4 uppsatser.