Ripening and quality of 'Laetitia' plums following harvest and cold storage as affected by inhibition of ethylene action

The inhibition of ethylene action by 1-methylcyclopropene (1-MCP) extends shelf and storage life of many climacteric fruits. However, 1-MCP appears to have limited effects on stone fruit depending on specie and cultivar. The effects of 1-MCP on ripening and quality of 'Laetitia' plums were determined during ripening at 23ºC following harvest and cold storage. Japanese plums (Prunus salicina, cv. Laetitia) were harvested at mature pre-climacteric stage, cooled to 2ºC within 36 hours of harvest and then treated with 0, 0.05, 0.10, 0.50 or 1.00 muL L-1 of 1-MCP at 1°C for 24 hours. Following treatment, fruits were either held at 23ºC for 16 days or stored at 1ºC for 50 days. Fruits were removed from cold storage at 10-day intervals and allowed to ripe at 23°C for five days. A delay of climacteric respiration and ethylene production by 1-MCP treatment during ripening following harvest and cold storage was associated to a slow rate of fruit softening. 1-MCP treatment also delayed the loss of titratable acidity and changes of flesh and skin color, whereas it had little or no effect on soluble solids content. 1-MCP effects were concentration- and storage duration-dependent and, generally, a saturation fruit response to 1-MCP occurred between 0.5 and 1.0 muL L-1. During ripening, 1-MCP treated fruits attained quality similar to that of controls. Results indicated that 1-MCP treatment may extend shelf life (23ºC) and storage life (1ºC) of 'Laetitia' plums by approximately six and 20 days, respectively.

Assessing the impact of high-pressure processing on selected physical and biochemical attributes of white cabbage (Brassica oleracea L. var. capitata alba)

The aim of this study was to investigate the effect of combined pressure/temperature treatments (200, 400 and 600 MPa, at 20 and 40 °C) on key physical and chemical characteristics of white cabbage (Brassica oleracea L. var. capitata alba). Thermal treatment (blanching) was also investigated and compared with high-pressure processing (HPP). HPP at 400 MPa and 20–40 °C caused significantly larger colour changes compared to any other pressure or thermal treatment. All pressure treatments induced a softening effect, whereas blanching did not significantly alter texture. Both blanching and pressure treatments resulted in a reduction in the levels of ascorbic acid, effect that was less pronounced for blanching and HPP at 600 MPa and 20–40 °C. HPP at 600 MPa resulted in significantly higher total phenol content, total antioxidant capacity and total isothiocyanate content compared to blanching. In summary, the colour and texture of white cabbage were better preserved by blanching. However, HPP at 600 MPa resulted in significantly higher levels of phytochemical compounds. The results of this study suggest that HPP may represent an attractive technology to process vegetable-based food products that better maintains important aspects related to the content of health-promoting compounds. This may be of particular relevance to the food industry sector involved in the development of convenient novel food products with excellent functional properties

Enzyme activities and pectin breakdown of sapodilla submitted to 1-methylcyclopropene

The objective of this work was to investigate the influence of 1-methylcyclopropene (1-MCP) at 300 nL L-1 on activities of cell wall hidrolytic enzymes and pectin breakdown changes which Sapodilla (Manilkara zapota cv. Itapirema 31) cell wall undergoes during ripening. Sapodilla were treated with ethylene antagonist 1-MCP at 300 nL L-1 for 12 hours and then, stored under a modified atmosphere at 25º C for 23 days. Firmness, total and soluble pectin and cell wall enzymes were monitored during storage. 1-MCP at 300 nL L-1 for 12 hours delayed significantly softening of sapodilla for 11 days at 25º C. 1-MCP postharvest treatment affected the activities of cell wall degrading enzymes pectinmethylesterase and polygalacturonase and completely suppressed increases in beta-galactosidase for 8 days, resulting in less pectin solubilization. Beta-galactosidase seems relevant to softening of sapodilla and is probably responsible for modification of both pectin and xyloglucan-cellulose microfibril network.

Application of 1-methylcyclopropene, calcium chloride and calcium amino acid chelate on fresh-cut cantaloupe muskmelon

The objective of this work was to determine the effects of postharvest application of 1-methylcyclopropene (1-MCP) and two calcium salts, applied individually or combined, on firmness and visual quality of fresh-cut muskmelon stored in air, for 18 days. Two sets of fruits, one of them exposed to 1-MCP at 300 nL L-1, were cut into cubes, dipped in deionized water, or in 1% Ca solutions as CaCl2, or in calcium amino acid chelate (Ca-chelate), placed in clamshell containers, and stored in air at 5±1ºC and 90±5% RH, for 18 days. The assay was conducted using an entirely randomized design, with three replications, in a split plot array. Evaluation of visual appearance, color, flesh firmness, total soluble solids, titratable acidity, and pH was performed right after treatments, and every period of three days, up to eighteen days. Application of 1-MCP at 300 nL L-1, calcium chloride or Ca-chelate, or the combination 1-MCP and calcium, preserved initial freshness and reduced softening of the samples. Ca-chelate synergistically enhanced the effect of 1-MCP on firmness after nine days of storage, while calcium chloride improved firmness of the samples throughout storage. Ca-chelate may serve as an alternative for shelf life extension of cantaloupe fresh-cut muskmelon.

The 2010 May Flaring Episode of Cygnus X-3 in Radio, X-rays, and γ-rays

In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV γ-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and soft X-ray, and γ-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a ~3 day softening and recovery of the X-ray emission, followed almost immediately by a ~1 Jy radio flare at 15 GHz, followed by a 4.3σ γ-ray flare (E > 100 MeV) ~1.5 days later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the γ-ray flare was followed by any significant unobserved radio flares. In this case, the sequencing of the observed events is difficult to explain in a model in which the γ-ray emission is due to inverse Compton scattering of the companion star's radiation field. Our observations suggest that other mechanisms may also be responsible for γ-ray emission from Cyg X-3.

Kosteuden ja lämpötilan vaikutus kartonkimassojen muovattavuuteen

Työn tavoitteena oli kartoittaa yleisesti kartongin valmistukseen käytettävien massatyyppien muovattavuuspotentaali. Muovattuvuuteen eniten vaikuttava tekijänä pidettiinmassojen murtovenymää. Työssä tutkittiin kosteuden ja lämpötilan sekä vetonopeuden vaikutusta mekaanisten ja sellumassojen ominaisuuksiin laboratorio-olosuhteissa. Kirjallisuusosassa tarkastellaan paperin lasisiirtymälämpötilaa muovauksen kannalta oleellisena tekijä. Lisäksi käydään läpi tapoja, joilla murtovenymää voidaan kasvattaa. Kartongin keskikerroksen aallotuksessa ja valmistettaessa paperipohjaisia tuotteita syvävedolla, käytetään hyväksi paperin pehmenemistä lämpötilan ja kosteuden alaisena. Niiden olosuhteita tarkastellaan lyhyesti. Lisäksi luodaan katsaus lämpötilan, kosteuden ja nopeuden vaikutuksistapaperin mekaanisiin ominaisuuksiin. Työn kokeellisessa osassa massojen mekaanisia ominaisuuksia testattiin erilaisissa kosteuspitoisuuksissasekä lämpötiloissa eri vetonopeuksilla. Kokeiden perusteella pyrittiin löytämään olosuhteet kullekin massalle, joissa niillä on paras murtovenymä. Lisäksi selvitettiin kuidun kihartamisen, sellumassojen jauhatuksen sekä arkin vapaan kuivumisen vaikutusta murtovenymään. Erilaiset massat saavuttavat parhaan murtovenymän erilaisissa kosteus- ja lämpötilaolosuhteissa. Sellumassoilla paras murtovenymä saadaan huoneenlämpötilassa ja paperin kosteuspitoisuuden ollessa välillä 11...12%. CTMP-massojen paras murtovenymä saadaan vedellä kyllästetyllä paperilla kohotetussa lämpötilassa. Lämpötila riippuu CTMP-massan valmistustavasta ja raaka-aineesta. Sellumassoilla on parempi kokonaisvenymä, kuin ligniinipitoisilla massoilla. Vetonopeuden vaikutus murtovenymään riippuu massasta sekä kosteudesta. Alhaisessa kosteudessa suurempi vetonopeus antaa aina pienemmän venymän. Kosteuden noustessa riippuu massasta, miten vetonopeus vaikuttaa murtovenymään. Plastinen osa tietystä venymästä on riippumaton massasta, jauhatusasteesta ja kuivatustavasta. Ainut vaikuttava muuttuja on kosteus. Kosteuden kasvu kasvattaa plastista venymää.

Effect of prestorage curing on storage life, internal and external qualities of sweet orange (Citrus sinensis)

Orange fruits from two seasons, in April and August 2006 representing late 2005 and early 2006 harvests respectively were cured in hot air at 36-37(0)C to 1%, 3%, 5% and 7% weight loss before storage at 28(0)C and 86% relative humidity (RH). The fruits were observed for incidence of decay, further weight loss, juice content, firmness or softening of the peel, total soluble solids (TSS), pH, titratable acidity, and colour during storage. Curing reduced the incidence of decay. All control fruits were rotten by day 21 in August harvest while 22.5% of the control was rotten by day 56 in the April harvest. Storage life was extended beyond 56 days in fruits cured with 1, 3, 5 and 7% in April harvest as there was no decay throughout, while decay incidence in August harvest was 88.9, 61.1, 22.2 and 31.3% in 1, 3, 5 and 7% respectively. Penicillium digitatum, Phytophthora sp., Alternaria citri and Collectotrichum gloeosporioides were among decay causing moulds detected. Control fruits lost more weight during storage than cured fruits did. Fruit rind hardening was more noticed in the control and those cured to 1% weight loss, especially from the April harvest. It was insignificant in other treatments in both trials. Titratable acidity, pH, juice content and TSS were not affected by the treatment. Colour change to yellow was however retarded by curing. Curing to 5% weight loss was best for decay control and quality retention.

Advances in apple culture worldwide

Over the last 60 years, planting densities for apple have increased as improved management systems have been developed. Dwarfing rootstocks have been the key to the dramatic changes in tree size, spacing and early production. The Malling series of dwarfing rootstocks (M.9 and M.26) have been the most important dwarfing rootstocks in the world but are poorly adapted in some areas of the world and they are susceptible to the bacterial disease fire blight and the soil disease complex, apple replant disease which limits their uses in some areas. Rootstock breeding programs in several parts of the world are developing improved rootstocks with resistance to fire blight, and replant disease, and improved cold hardiness and yield efficiency. A second important trend has been the increasing importance of new cultivars. New cultivars have provided opportunities for higher prices until they are over-produced. A new trend is the "variety club" in which variety owners manage the production and marketing of a new unique cultivar to bring higher prices to the growers and variety owners. This has led to many fruit growers being unable to plant or grow some new cultivars. Important rootstock and cultivar genes have been mapped and can be used in marker assisted selection of future rootstock and cultivar selections. Other important improvements in apple culture include the development of pre-formed trees, the development of minimal pruning strategies and limb angle bending which have also contributed to the dramatic changes in early production in the 2nd-5th years after planting. Studies on light interception and distribution have led to improved tree forms with better fruit quality. Simple pruning strategies and labor positioning platform machines have resulted in partial mechanization of pruning which has reduced management costs. Improved plant growth regulators for thinning and the development of a thinning prediction model based on tree carbohydrate balance have improved the ability to produce the optimum fruit size and crop load. Other new plant growth regulators have also allowed control of shoot growth, control of preharvest fruit drop and control of fruit softening in storage after harvest. As we look to the future, there will be continued incremental improvement in our understanding of plant physiology that will lead to continued incremental improvements in orchard management but there is likely to be dramatic changes in orchard production systems through genomics research and genetic engineering. A greater understanding of the genetic control of dwarfing, precocity, rooting, vegetative growth, flowering, fruit growth and disease resistance which will lead to new varieties and rootstocks which are less expensive to grow and manage.

The 2010 May Flaring Episode of Cygnus X-3 in Radio, X-rays, and γ-rays

In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV γ-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and soft X-ray, and γ-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a ~3 day softening and recovery of the X-ray emission, followed almost immediately by a ~1 Jy radio flare at 15 GHz, followed by a 4.3σ γ-ray flare (E > 100 MeV) ~1.5 days later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the γ-ray flare was followed by any significant unobserved radio flares. In this case, the sequencing of the observed events is difficult to explain in a model in which the γ-ray emission is due to inverse Compton scattering of the companion star's radiation field. Our observations suggest that other mechanisms may also be responsible for γ-ray emission from Cyg X-3.

Lujien terästen hitsauksen kehittäminen

Työn teoriaosuudessa käsitellään lujia hitsattavia teräksiä sekä niiden hitsauksessa huomioitavia erityispiirteitä. Työssä esitellään hitsattavuuden arviointiin kehitettyjä teoreettisia menetelmiä sekä otetaan kantaa hitsauksen suoritustekniikkaan ja lisäainevalintaan. Myös lujien terästen hitsauksessa tyypilliset hitsausvirheet on käsitelty tässä työssä. Työn kokeellisessa osassa selvitettiin metsäteknologian tuotteita valmistavan metalliyrityksen käyttämien lujien terästen hitsattavuus ja hitsauksen esivalmistelujen tarpeellisuus. Kokeelliseen osioon kuului myös sopivan lisäainelangan valinta sekä tarkempaan tarkasteluun valitun esimerkkituotteen hitsien laadun selvittäminen. Tutkimuksissa käytettyjä menetelmiä olivat makro- ja mikrohietutkimus, hitsausliitoksen poikittainen vetokoe, Vickersin kovuuskoe ja murtokoe. Tarkasteluissa peilautuu myös hitsauksen automatisoinnin vaikutukset lujien terästen hitsaukseen. Kokeellisessa osiossa huomattiin nuorrutettujen terästen pehmeneminen liian suurella lämmöntuonnilla. Termomekaanisesti valssatut teräkset ovat paremmin hitsattavissa kuin nuorrutetut ja karkaistut teräkset. Kyseessä olevassa yrityksessä hitsattavien materiaalien paksuudet ovat pääsääntöisesti niin ohuita, ettei korotettua työlämpötilaa tarvita. Alilujat lisäaineet soveltuvat hitsauslisäaineeksi tuotantokäyttöön muutamia tuotekohtaisia poikkeuksia lukuun ottamatta.

Polifosfatos em detergentes em pó comerciais

A didactic experiment is proposed in order to identify inorganic phosphates in home laundry detergents by ascending paper chromatography. Chemical principles related with hard water are also investigated. The role of polyphosphates in detergent formulations is discussed and the softening of hard water by sodium tripolyphosphate is illustrated. Several chemical concepts, related to the daily experience of the students, can be explored in post-lab discussions.

A Practical Micro Mechanical Model Based Local Approach Methodology for the Analysis of Ductile Fracture of Welded T-Joints

This thesis concentrates on developing a practical local approach methodology based on micro mechanical models for the analysis of ductile fracture of welded joints. Two major problems involved in the local approach, namely the dilational constitutive relation reflecting the softening behaviour of material, and the failure criterion associated with the constitutive equation, have been studied in detail. Firstly, considerable efforts were made on the numerical integration and computer implementation for the non trivial dilational Gurson Tvergaard model. Considering the weaknesses of the widely used Euler forward integration algorithms, a family of generalized mid point algorithms is proposed for the Gurson Tvergaard model. Correspondingly, based on the decomposition of stresses into hydrostatic and deviatoric parts, an explicit seven parameter expression for the consistent tangent moduli of the algorithms is presented. This explicit formula avoids any matrix inversion during numerical iteration and thus greatly facilitates the computer implementation of the algorithms and increase the efficiency of the code. The accuracy of the proposed algorithms and other conventional algorithms has been assessed in a systematic manner in order to highlight the best algorithm for this study. The accurate and efficient performance of present finite element implementation of the proposed algorithms has been demonstrated by various numerical examples. It has been found that the true mid point algorithm (a = 0.5) is the most accurate one when the deviatoric strain increment is radial to the yield surface and it is very important to use the consistent tangent moduli in the Newton iteration procedure. Secondly, an assessment of the consistency of current local failure criteria for ductile fracture, the critical void growth criterion, the constant critical void volume fraction criterion and Thomason's plastic limit load failure criterion, has been made. Significant differences in the predictions of ductility by the three criteria were found. By assuming the void grows spherically and using the void volume fraction from the Gurson Tvergaard model to calculate the current void matrix geometry, Thomason's failure criterion has been modified and a new failure criterion for the Gurson Tvergaard model is presented. Comparison with Koplik and Needleman's finite element results shows that the new failure criterion is fairly accurate indeed. A novel feature of the new failure criterion is that a mechanism for void coalescence is incorporated into the constitutive model. Hence the material failure is a natural result of the development of macroscopic plastic flow and the microscopic internal necking mechanism. By the new failure criterion, the critical void volume fraction is not a material constant and the initial void volume fraction and/or void nucleation parameters essentially control the material failure. This feature is very desirable and makes the numerical calibration of void nucleation parameters(s) possible and physically sound. Thirdly, a local approach methodology based on the above two major contributions has been built up in ABAQUS via the user material subroutine UMAT and applied to welded T joints. By using the void nucleation parameters calibrated from simple smooth and notched specimens, it was found that the fracture behaviour of the welded T joints can be well predicted using present methodology. This application has shown how the damage parameters of both base material and heat affected zone (HAZ) material can be obtained in a step by step manner and how useful and capable the local approach methodology is in the analysis of fracture behaviour and crack development as well as structural integrity assessment of practical problems where non homogeneous materials are involved. Finally, a procedure for the possible engineering application of the present methodology is suggested and discussed.

Lipídios estruturados obtidos a partir da mistura de gordura de frango, sua estearina e triacilgliceróis de cadeia média: II- pontos de amolecimento e fusão

The aim of the present work is to investigate the effects of blending and chemical interesterification reactions on the softening and melting behavior of chicken fat, its stearin and medium chain triacylglycerols, and blends thereof in various ratios. Chemical interesterification is a promising alternative to the current processes of modifying the physical properties of fats. In the experimental design 7 samples corresponding to 7 different blend proportions were used. The results were represented in triangular diagrams. The addition of stearin influenced the softening and melting points. The mixture response surface methodology proved to be an extremely useful tool for the optimization of the fat mixtures.

Lipídios modificados obtidos a partir de gordura do leite, óleo de girassol e ésteres de fitosteróis para aplicação em spreads

The objective of this paper was to evaluate the modifications in milkfat properties with the addition of sunflower oil (SO) and phytosterol esters (PE) and chemical interesterification. Fatty acid composition, softening point and consistency were determined. The saturation degree of milkfat decreased with the addition of SO and PE. Consequently, milkfat presented lower softening point and consistency. Chemical interesterification caused an increase in softening point due to the formation of higher amounts of trissaturated triacylglycerols with rearrangement. The incorporation of unsaturated fatty acids from SO and PE by milkfat triacylglycerols after chemical reaction caused linearization of consistency curves.

Performance during post-harvest storage of banana cv. 'prata', 'maçã' and 'nanica' exposed to physical and chemical treatments

Banana is the most consumed fruit in the world and Brazil is the second largest producer. Despite its global position, Brazil has an average of 40% losses during the post-harvest period. So, this experiment aimed at evaluating the efficiency of post-harvest treatments to improve the storage of banana cultivars cv. 'Prata', 'Maçã' and 'Nanica'. The fruits were acquired at CEASA with green peel, and were submitted to six different treatments: T- immersion in drinking water for 3 minutes (control), H3 - hot water (50 °C for 3 minutes), H8 - hot water (50 °C for 8 minutes), HP - immersion in hypochlorite 0.2% for 3 minutes, OS - immersion in soybean oil 10% for 3 minutes, and OM - immersion in mineral oil 10% for 3 minutes. The fruits were stored at room temperature at about 21 °C for 14 days and evaluated in three periods (1, 7 and 14 days) comparing peel color, flesh/peel ratio, titratable acidity (TA), soluble solids (SS), SS/TA ratio, and pH. The fruits of cv. 'Prata' and 'Maçã' submitted to the treatments H3, H8 and HP ripened at the same time as the control for peel color, which showed increased soluble solids, flesh/peel ratio, acidity and a decrease in pH. On the other hand, the cv. 'Nanica' did not respond significantly different when compared to the applied treatments and the control. The fruits treated with OM and OS were kept green for a longer time for the cultivars 'Prata' and 'Nanica', but there were some changes on peel color due dark spots in 'Prata' banana and a softening aspect in 'Nanica', indicating some level of toxicity of these treatments. Fruits of the 'Maçã' cultivar continued green with the application of mineral oil, without toxicity symptoms. In conclusion, the treatments applied did not show any advantage for storage of these fruits.