scholarly journals The Response of Tomato Fruit Cuticle Membranes Against Heat and Light

2022 ◽  
Vol 12 ◽  
Author(s):  
José J. Benítez ◽  
Ana González Moreno ◽  
Susana Guzmán-Puyol ◽  
José A. Heredia-Guerrero ◽  
Antonio Heredia ◽  
...  
Keyword(s):  
Glass Transition ◽  
Phenolic Compounds ◽  
Developmental Stage ◽  
Tomato Fruit ◽  
Seasonal Temperature ◽  
Scanning Calorimetry ◽  
Chain Mobility ◽  
Structural Rigidity ◽  
The One

Two important biophysical properties, the thermal and UV-Vis screening capacity, of isolated tomato fruit cuticle membranes (CM) have been studied by differential scanning calorimetry (DSC) and UV-Vis spectrometry, respectively. A first order melting, corresponding to waxes, and a second order glass transition (Tg) thermal events have been observed. The glass transition was less defined and displaced toward higher temperatures along the fruit ripening. In immature and mature green fruits, the CM was always in the viscous and more fluid state but, in ripe fruits, daily and seasonal temperature fluctuations may cause the transition between the glassy and viscous states altering the mass transfer between the epidermal plant cells and the environment. CM dewaxing reduced the Tg value, as derived from the role of waxes as fillers. Tg reduction was more intense after polysaccharide removal due to their highly interwoven distribution within the cutin matrix that restricts the chain mobility. Such effect was amplified by the presence of phenolic compounds in ripe cuticle membranes. The structural rigidity induced by phenolics in tomato CMs was directly reflected in their mechanical elastic modulus. The heat capacity (Cprev) of cuticle membranes was found to depend on the developmental stage of the fruits and was higher in immature and green stages. The average Cprev value was above the one of air, which confers heat regulation capacity to CM. Cuticle membranes screened the UV-B light by 99% irrespectively the developmental stage of the fruit. As intra and epicuticular waxes contributed very little to the UV screening, this protection capacity is attributed to the absorption by cinnamic acid derivatives. However, the blocking capacity toward UV-A is mainly due to the CM thickness increment during growth and to the absorption by flavone chalconaringenin accumulated during ripening. The build-up of phenolic compounds was found to be an efficient mechanism to regulate both the thermal and UV screening properties of cuticle membranes.

Glassy State in Plant Cuticles during Growth

1994 ◽  
Vol 49 (3-4) ◽  
pp. 273-275 ◽  
Author(s):  
Patricia Luque ◽  
Antonio Heredia
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Tomato Fruit ◽  
Glassy State ◽  
Fruit Growth ◽  
Scanning Calorimetry ◽  
Plant Cuticles ◽  
Second Order Transition

The existence of a glassy state in isolated tomato fruit cuticles was investigated using differential scanning calorimetry. Tomato fruit cuticular membranes showed a glass transition temperature at -30 °C and an additional second order transition temperature near 30 °C. Changes in these temperatures during fruit growth were also studied

Thermal Properties of Hyperbranched Polymer/HTPB-PU IPN

2013 ◽  
Vol 575-576 ◽  
pp. 76-80
Author(s):  
Xue Jing Song ◽  
Yun Jun Luo
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Melting Point ◽  
Hyperbranched Polymer ◽  
Isophorone Diisocyanate ◽  
Scanning Calorimetry

Hyperbranched polymer/HTPB-PU IPNs were prepared, when HTPB (hydroxyl-terminated polybutadiene) and IPDI (isophorone diisocyanate) were cured into polyurethane (HTPB-PU) at the existence of hyperbranched polymer. Differential scanning calorimetry (DSC) was adopted to study the influence of hyperbranched polymer on thermal properties of HTPB-PU, while IPNs were formed. The result shows that the existance of hyperbranched polymer makes glass transition temperature of HTPB-PU reduces by around 2°C and that HTPB-PU lowers the melting point of hyperbranched polymer. Hyperbranched polymer plays a role of internal plasticization on HTPB-PU, and HTPB-PU influences crystallization of hyperbranched polymer in return.

scholarly journals Determination of glass transition temperature and surface properties of novel chalcone modified poly (styrene) based polymer

2019 ◽  
Vol 23 (Suppl. 1) ◽  
pp. 193-202
Author(s):  
Aysegul Adiguzel ◽  
Fatih Cakar ◽  
Bahire Senkal ◽  
Ozlem Cankurtaran ◽  
Yesim Gursel ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Surface Properties ◽  
The Novel ◽  
Scanning Calorimetry ◽  
Chromatography Method ◽  
Kd Values ◽  
The One

The novel chalcone modified poly (styrene) based polymer (PVBC-DMAC) has been prepared and characterized. By using the inverse gas chromatography method, we determined glass transition temperature and surface properties of PVBC-DMAC. The obtained glass transition temperature, Tg, is a good agree with the one obtained by differential scanning calorimetry. Also considering some isomeric alcohol and acetate solvents in the temperature range from 303.2 K to 353.2 K, we investigated the polymer selectivity. The parameters KA(acidic) and KD(basic) of the PVBC-DMAC surface were calculated. The obtained KA, KD values reflected that PVBC-DMAC surface has a basic character.

Poly(lactic acid) phase transitions in the presence of nano calcium carbonate: Opposing effect of nanofiller on static and dynamic measurements

2018 ◽  
Vol 32 (3) ◽  
pp. 312-327 ◽  
Author(s):  
Omid Yousefzade ◽  
Javad Jeddi ◽  
Elham Vazirinasab ◽  
Hamid Garmabi
Keyword(s):  
Lactic Acid ◽  
Glass Transition ◽  
Calcium Carbonate ◽  
Mechanical Analysis ◽  
Polymer Chains ◽  
Poly Lactic Acid ◽  
Modulated Dsc ◽  
Scanning Calorimetry ◽  
Chain Mobility ◽  
Dispersion State

The effect of stearic acid-coated nano calcium carbonate (NCC) on transitions and chain mobility of poly(lactic acid) (PLA) was investigated. Dispersion state of NCC in polymeric matrix was explored using scanning electron microscopy and surface tension component measurements. Trends of PLA transitional phenomena were investigated using the results of dynamical mechanical analysis (DMA) and differential scanning calorimetry (DSC) in the nanocomposite systems based on PLA and NCC. In addition, two types of crystal structures and decreasing the glass transition temperature were distinguished using temperature-modulated DSC (TMDSC). Higher melting points of polymer crystals were found in TMDSC experiments due to low and dynamic heating rate compared to the conventional DSC. Dynamics of polymer chains, affected by NCC, were quantified using cooperativity length, ξ α, and the number of relaxing structural units, Nα, in the glass transition region. NCC particles hindered the cooperative motion of polymer chains at glass transitions and crystallization in TMDSC measurements, whereas the DMA results indicated that NCC particles may act as lubricant and simplified chain mobility.

You Are the One I Want to Communicate With!

2013 ◽  
Vol 44 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Sabrina Pierucci ◽  
Olivier Klein ◽  
Andrea Carnaghi
Keyword(s):  
Memory Bias ◽  
Shared Reality ◽  
Communication Partner ◽  
Shared Reality Theory ◽  
The One ◽  
Study Participants

This article investigates the role of relational motives in the saying-is-believing effect ( Higgins & Rholes, 1978 ). Building on shared reality theory, we expected this effect to be most likely when communicators were motivated to “get along” with the audience. In the current study, participants were asked to describe an ambiguous target to an audience who either liked or disliked the target. The audience had been previously evaluated as a desirable vs. undesirable communication partner. Only participants who communicated with a desirable audience tuned their messages to suit their audience’s attitude toward the target. In line with predictions, they also displayed an audience-congruent memory bias in later recall.

The Formation of Intermediate Product I in a Purified System The Role of Factor IX or of its Precursor and of a Hageman Factor-PTA Fraction

1961 ◽  
Vol 6 (02) ◽  
pp. 224-234 ◽  
Author(s):  
E. T Yin ◽  
F Duckert
Keyword(s):  
Intermediate Product ◽  
Factor Ix ◽  
Assay Method ◽  
Lag Phase ◽  
Factor X ◽  
Haemophilia B ◽  
Hageman Factor ◽  
One Stage ◽  
The One

Summary1. The role of two clot promoting fractions isolated from either plasma or serum is studied in a purified system for the generation of intermediate product I in which the serum is replaced by factor X and the investigated fractions.2. Optimal generation of intermediate product I is possible in the purified system utilizing fractions devoid of factor IX one-stage activity. Prothrombin and thrombin are not necessary in this system.3. The fraction containing factor IX or its precursor, no measurable activity by the one-stage assay method, controls the yield of intermediate product I. No similar fraction can be isolated from haemophilia B plasma or serum.4. The Hageman factor — PTA fraction shortens the lag phase of intermediate product I formation and has no influence on the yield. This fraction can also be prepared from haemophilia B plasma or serum.

THE ROLE OF ANTHROPONYMS IN THE SEMANTIC FIELD OF ARTISTIC WORKS

2019 ◽  
Vol 2019 (29) ◽  
pp. 66-77
Author(s):  
Lidiya Derbenyova
Keyword(s):  
Literary Work ◽  
Main Theme ◽  
Semantic Field ◽  
New Meanings ◽  
Minor Part ◽  
The One ◽  
A Minor ◽  
And Storage ◽  
Horizon Of Expectations

The article explores the role of antropoetonyms in the reader’s “horizon of expectation” formation. As a kind of “text in the text”, antropoetonyms are concentrating a large amount of information on a minor part of the text, reflecting the main theme of the work. As a “text” this class of poetonyms performs a number of functions: transmission and storage of information, generation of new meanings, the function of “cultural memory”, which explains the readers’ “horizon of expectations”. In analyzing the context of the literary work we should consider the function of antropoetonyms in vertical context (the link between artistic and other texts, and the groundwork system of culture), as well as in the context of the horizontal one (times’ connection realized in the communication chain from the word to the text; the author’s intention). In this aspect, the role of antropoetonyms in the structure of the literary text is extremely significant because antropoetonyms convey an associative nature, generating a complex mechanism of allusions. It’s an open fact that they always transmit information about the preceding text and suggest a double decoding. On the one hand, the recipient decodes this information, on the other – accepts this as a sort of hidden, “secret” sense.

Public Procurement Principles Generated by the Treaty of Rome

2020 ◽  
Vol 26 (2) ◽  
pp. 217-223
Author(s):  
Ioan-Gabriel Popa
Keyword(s):  
European Economic Community ◽  
Public Procurement ◽  
Free Movement ◽  
European Directives ◽  
Community Institutions ◽  
Treaty Of Rome ◽  
General Principles Of Law ◽  
Free Movement Of Goods ◽  
The One

AbstractIn order to understand the principles of public procurement in Romania, it is necessary to analyze, on the one hand, the European directives that regulate the actual public procurement and, on the other hand, the context in which the European directives were adopted. Even with the directives in force, the more general provisions contained in the Treaty of the European Economic Community (EEC) in Rome, hereinafter referred to as the Treaty, are applied, as well as many more general principles of law that will guide the interpretation of these directives. The Treaty was adopted in Rome, in 1957 and became applicable from January 1, 1958. It is considered that the source of the principles of public procurement is the Treaty. Even if in Treaty contained no specific provisions regarding the field of public procurement, it reflects the principles and the general framework for the functioning of the single market, a market characterized through the prism of the fundamental freedoms established by the Treaty: the free movement of goods, services, capital and persons. As the field of public procurement is closely linked to the free movement of goods, this principle is promoted and implemented in the practice of this field based on the regulations, directives and decisions of the Community institutions. The role of the free movement of goods is to harmonize the relationships involved in the process of purchasing goods, but also to ensure the homogeneity, coherence and balance of this process.

Sign in / Sign up

Export Citation Format

Share Document