scholarly journals Responses of quinoa (Chenopodium quinoa Willd.) seeds stored under different germination temperatures

2017 ◽  
Vol 39 (1) ◽  
pp. 83 ◽  
Author(s):  
Andressa Strenske ◽  
Edmar Soares de Vasconcelos ◽  
Vanessa Aline Egewarth ◽  
Neusa Francisca Michelon Herzog ◽  
Marlene De Matos Malavasi
Keyword(s):  
Room Temperature ◽  
Storage Time ◽  
Chenopodium Quinoa ◽  
Seed Vigor ◽  
Continuous Darkness ◽  
Experimental Conditions ◽  
Growing Seasons ◽  
Germinating Seeds ◽  
Germinated Seeds ◽  
Plot Design

In this experiment, we assessed the germination and vigor of quinoa seeds packed in paper bags and stored at room temperature for 36, 85, 119, 146, 177 and 270 days. The seeds were harvested under experimental conditions in Marechal Candido Rondon, Paraná, during the 2012/13 growing seasons. Four replicates of 100 seeds each were established for each storage time, and the seeds were evaluated, on paper, based on the BOD under the following experimental temperature conditions: alternating temperatures of 20 and 30°C and a constant temperature of 25°C. The seeds from both treatments were subject to seven-hour photoperiods and 25°C under continuous darkness. The germinated seeds were counted daily for eight days after sowing, and we evaluated the percentages of normal and abnormal seedlings and the germination index. The experimental design was completely randomized using a split-plot design. Increasing the storage time decreased the percentage of germinated seeds and seed vigor due to the increased number of abnormal seedlings. Over the 430-day study period, quinoa seed germination completely declined under the experimental conditions. The final number of germinating seeds should be evaluated 7 days after the beginning of the germination test. 

The volatile exudates from germinating pea seeds of different viability and vigor

1985 ◽  
Vol 63 (6) ◽  
pp. 1035-1039 ◽  
Author(s):  
R. J. Gorecki ◽  
G. E. Harman ◽  
L. R. Mattick
Keyword(s):  
Gas Chromatography ◽  
Relative Humidity ◽  
Trichoderma Harzianum ◽  
Storage Time ◽  
Enterobacter Cloacae ◽  
Storage Condition ◽  
Seed Vigor ◽  
Embryonic Axes ◽  
Pea Seeds ◽  
Germinating Seeds

Pea seeds var. Kriter were stored aseptically at 92% relative humidity and 30 °C. After 0, 4, 6, 8, or 10 weeks of storage, viability, vigor, and volatile exudates were determined on sublots of seeds. As storage time increased, vigor, as measured by dehydrogenase activity, growth of embryonic axes, and conductivity decreased. Later, viability also decreased. Imbibing and germinating pea seeds produced ethanol, acetaldehyde, and lesser amounts of methanol. No qualitative differences in volatile exudates were observed from germinating seeds regardless of age or storage condition. Nonaged seeds with highest vigor produced the smallest amounts of volatiles, but with increased aging the quantities of ethanol and acetaldehyde gradually increased. Dry seed produced small quantities of both volatiles. The amount of these compounds produced reached a maximum between 12 and 48 h of germination. Infestation of seed samples with Enterobacter cloacae or Trichoderma harzianum reduced the quantities of these compounds measured. These results indicate that determinations of acetaldehyde and ethanol in the space over germinating seeds by means of gas chromatography may be a useful seed vigor test.

scholarly journals Colorimetric parameters as a stability indicative of banana alcoholic extract submitted to storage

2020 ◽  
Vol 9 (9) ◽  
pp. e884998227
Author(s):  
Josef Gastl Filho ◽  
Millena Almeida Resende ◽  
Flávio Caldeira Silva
Keyword(s):  
Food Industry ◽  
Room Temperature ◽  
Storage Time ◽  
Storage Period ◽  
Raw Material ◽  
Banana Peel ◽  
Alcoholic Extract ◽  
The Stability ◽  
Plot Design

Studying the stability of the raw material as a function of the storage time is fundamental to establish the characteristics performance and to determine the period that it should be stored. The objective of the present study was to evaluate the stability of the alcoholic extract for 28 days of storage. It was performed in a completely randomized and split-plot design (3x5) with 3 repetitions and using the following formulation: 500 g of banana components (peel, pulp or peel plus pulp), 1000 mL of cereal alcohol 96 ºGL and maceration process for fifteen days. Filtered alcoholic extracts were stored in a dark place at room temperature for analysis of colorimetric parameters Luminosity, hue, chroma, chromaticity a* and chromaticity b*. Results showed that storage period for 28 days significantly affected stability, promoting notable reduction in Luminosity, hue, chromaticity b* and chroma and also increased the chromaticity value chromaticity a*. It was observed that the banana pulp alcoholic extract showed the highest values for Luminosity and hue, and the banana peel alcoholic extract stood out in relation to the chromaticity chroma, chromaticity a* and chromaticity b*. The information obtained through colorimetric parameters can be used by the food industry to establish procedures that mitigate the effects of the storage period in the raw material, since the characteristics inherent to the raw material are significantly changed over time and result in changes in the quality of the final product.

Threshold temperatures for seed germination in nine species ofVerbascum(Scrophulariaceae)

2015 ◽  
Vol 26 (1) ◽  
pp. 30-46 ◽  
Author(s):  
Stefania Catara ◽  
Antonia Cristaudo ◽  
Andrea Gualtieri ◽  
Rosario Galesi ◽  
Carmen Impelluso ◽  
...  
Keyword(s):  
Seed Germination ◽  
Storage Time ◽  
Soil Surface ◽  
Mediterranean Area ◽  
Effect Of Temperature ◽  
Continuous Darkness ◽  
Threshold Temperatures ◽  
D 12 ◽  
Germinating Seeds ◽  
Fluctuating Temperatures

AbstractLight and fluctuating temperatures are two important factors triggering seed germination. The aim of this work was to: (1) elucidate the effect of temperature, light regime and storage time on seed germination in nine taxa ofVerbascumspp., collected from different habitats in the Mediterranean area; and (2) estimate threshold temperatures for seed germination. For all taxa, germination assays were performed at constant and fluctuating temperatures, both in continuous darkness (D) and in alternating light/dark (L/D; 12 h photoperiod). Final germinated proportions (FGPs), base (Tb), optimal (To) and cut-off (Tc) temperatures were derived. At constant temperatures, seed germination was strongly suppressed under the D regime. In L/D, the effect of storage time was very small and the highest FGPs were observed from 15 to 30°C (40–100%), depending on the species.Tbranged from below 7 to above 10°C and it appeared to be constant within each seed lot.ToandTcshowed some within-lot variability and were higher for fast-germinating seeds in each lot. Considering fluctuating temperatures, germination appeared to be quicker and more complete than at constant temperatures. The germination ofVerbascumspp. is favoured in L/D and fluctuating temperatures, which explains their pioneer character when positioned near the soil surface and under a low vegetation canopy.V. arcturusandV. pinnatifidumwere shown to be less favoured by L and fluctuating temperatures, which might explain their ability to germinate in rocky areas or sandy dunes, even when they are not directly exposed to the light.

A Reinvestigation of the Deceptively Simple Reaction of Toluene with ●OH, and the Fate of the Benzyl Radical. I. a Combined Thermodynamic and Kinetic Study on the Competition Between ●OH Addition and Hydrogen Abstraction Reactions.

2019 ◽  
Author(s):  
Zoi Salta ◽  
Agnie M. Kosmas ◽  
Marc E. Segovia ◽  
Martina Kieninger ◽  
Oscar Ventura ◽  
...  
Keyword(s):  
Density Functional ◽  
Room Temperature ◽  
Hydrogen Abstraction ◽  
Reaction Rates ◽  
Composite Model ◽  
Alternative Mechanism ◽  
Radical Intermediate ◽  
Experimental Conditions ◽  
Methyl Group ◽  
Benzyl Radical

This work reports density functional and composite model chemistry calculations performed on the reactions of toluene with the hydroxyl radical. Both experimentally observed H-abstraction from the methyl group and possible additions to the phenyl ring were investigated. Reaction enthalpies and heights of the barriers suggest that H-abstraction is more favorable than ●OH addition to the ring. The calculated reaction rates at room temperature and the radical-intermediate product fractions support this view. This is somehow contradictory with the fact that, under most experimental conditions, cresols are observed in a larger concentration than benzaldehyde. Since the accepted mechanism for benzaldehyde formation involves H-abstraction, a contradiction arises that begs for an explanation. In this first part of our work we give the evidences that support the preference of hydrogen abstraction over ●OH addition and suggest an alternative mechanism which shows that cresols can actually arise also from the former reaction and not only from the latter.

A Reinvestigation of the Deceptively Simple Reaction of Toluene with ●OH, and the Fate of the Benzyl Radical. I. a Combined Thermodynamic and Kinetic Study on the Competition Between ●OH Addition and Hydrogen Abstraction Reactions.

2019 ◽  
Author(s):  
Zoi Salta ◽  
Agnie M. Kosmas ◽  
Marc E. Segovia ◽  
Martina Kieninger ◽  
Oscar Ventura ◽  
...  
Keyword(s):  
Density Functional ◽  
Room Temperature ◽  
Hydrogen Abstraction ◽  
Reaction Rates ◽  
Composite Model ◽  
Alternative Mechanism ◽  
Radical Intermediate ◽  
Experimental Conditions ◽  
Methyl Group ◽  
Benzyl Radical

This work reports density functional and composite model chemistry calculations performed on the reactions of toluene with the hydroxyl radical. Both experimentally observed H-abstraction from the methyl group and possible additions to the phenyl ring were investigated. Reaction enthalpies and heights of the barriers suggest that H-abstraction is more favorable than ●OH addition to the ring. The calculated reaction rates at room temperature and the radical-intermediate product fractions support this view. This is somehow contradictory with the fact that, under most experimental conditions, cresols are observed in a larger concentration than benzaldehyde. Since the accepted mechanism for benzaldehyde formation involves H-abstraction, a contradiction arises that begs for an explanation. In this first part of our work we give the evidences that support the preference of hydrogen abstraction over ●OH addition and suggest an alternative mechanism which shows that cresols can actually arise also from the former reaction and not only from the latter.

scholarly journals Comparison of preservation methods of Atta spp. (Hymenoptera: Formicidae) for RAPD analysis

2000 ◽  
Vol 29 (3) ◽  
pp. 489-496 ◽  
Author(s):  
Alfredo O. R. Carvalho ◽  
Luiz G. E. Vieira
Keyword(s):  
Silica Gel ◽  
Low Temperatures ◽  
Room Temperature ◽  
Rapd Analysis ◽  
Limiting Factors ◽  
Dna Yield ◽  
Remote Locations ◽  
Leaf Cutting ◽  
Storage Methods ◽  
Plot Design

High quality DNA for molecular studies can be easily extracted from fresh specimens. However, live samples are difficult to keep for long periods thus making their preservation a serious problem, specially when they are collected and transported from remote locations. In order to establish an efficient method to preserve Atta spp. (leaf-cutting ants) for RAPD analysis, six different storage methods were examined: 1) -70°C; 2) 95% ethanol at -20°C; 3) 95% ethanol at 4°C; 4) 95% ethanol at room temperature; 5) silica gel at room temperature; and 6) buffer (0.25 M EDTA, 2.5% SDS, 0.5 M Tris-HCl, pH 9.2) at room temperature. DNA was extracted (Cheung et al., 1993 - modified) and examined after 90, 210 and 360 days of storage. Freshly killed specimens were used as control. DNA yield was measured with a minifluorometer. DNA quality was determined by scanning photographs with a densitometer and the integral of the scan was calculated for DNA of size > 9.4 kb. Data were analyzed using a completely randomized split-plot design with four replicates. All methods were efficient to preserve Atta spp. DNA up to 210 days. At 360 days, DNA was degraded only in 95% ethanol at room temperature, which resulted in RAPD profiles with missing bands. Although preservation at low temperatures is recommended for long periods, methods using silica gel and buffer can be considered satisfactory alternatives when refrigeration and transportation are limiting factors.

scholarly journals Materials for Future Quantum Dot-Based Memories

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
T. Nowozin ◽  
D. Bimberg ◽  
K. Daqrouq ◽  
M. N. Ajour ◽  
M. Awedh
Keyword(s):  
Cross Sections ◽  
Room Temperature ◽  
Storage Time ◽  
Thermal Emission ◽  
Current Status ◽  
Strong Electron ◽  
Self Organized ◽  
Hole Confinement ◽  
Storage Times ◽  
Capture Cross Sections

The present paper investigates the current status of the storage times in self-organized QDs, surveying a variety of heterostructures advantageous for strong electron and/or hole confinement. Experimental data for the electronic properties, such as localization energies and capture cross-sections, are listed. Based on the theory of thermal emission of carriers from QDs, we extrapolate the values for materials that would increase the storage time at room temperature to more than millions of years. For electron storage, GaSb/AlSb, GaN/AlN, and InAs/AlSb are proposed. For hole storage, GaSb/Al0.9Ga0.1As, GaSb/GaP, and GaSb/AlP are promising candidates.

The Evolution Behavior of Defects in the Nanofilms of W/Cu and W Probed by Doppler Broadening Positron Annihilation Spectroscopy

2017 ◽  
Vol 373 ◽  
pp. 104-107
Author(s):  
Ling Wang ◽  
Ai Hong Deng ◽  
Kang Wang ◽  
Yong Wang ◽  
Xiao Bo Lu ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Positron Annihilation ◽  
Room Temperature ◽  
Storage Time ◽  
Positron Annihilation Spectroscopy ◽  
Doppler Broadening ◽  
Radio Frequency Magnetron Sputtering ◽  
Helium Ions ◽  
Near Surface ◽  
Evolution Behavior

W/Cu multilayer nanofilms and pure W nanofilms were prepared in pure Ar and He/Ar mixing atmosphere by radio frequency magnetron sputtering method. The defect evolution of the samples was characterized by Doppler broadening positron annihilation spectroscopy (DB-PAS).The results show that plenty of defects can be produced by introducing helium (He) into W/Cu multilayer nanofilms. With the natural storage time increasing, the helium located in the near surface of W/Cu multilayer nanofilm would be released gradually and induce the coalescence of the helium related defects due to the diffusion of the helium and defects. In addition, the pure W nanofilms were irradiated by 30 keV helium ions and 40 keV hydrogen (H) ions in sequence at room temperature. From the DB-PAS analysis, it can be shown that a large number of vacancy-type defects are produced due to the He and/or H irradiation. H ions would be trapped by He related defects and produced He-H-V complexes.

Long-term Room Temperature Instability in Thermal Conductivity of InGaZnO Thin Films

MRS Advances ◽  
2016 ◽  
Vol 1 (22) ◽  
pp. 1631-1636 ◽  
Author(s):  
Boya Cui ◽  
D. Bruce Buchholz ◽  
Li Zeng ◽  
Michael Bedzyk ◽  
Robert P. H. Chang ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Room Temperature ◽  
Storage Time ◽  
Laser Deposition ◽  
Low Oxygen ◽  
X Ray Diffraction ◽  
3Ω Method ◽  
X Ray

ABSTRACTThe cross-plane thermal conductivities of InGaZnO (IGZO) thin films in different morphologies were measured on three occasions within 19 months, using the 3ω method at room temperature 300 K. Amorphous (a-), semi-crystalline (semi-c-) and crystalline (c-) IGZO films were grown by pulsed laser deposition (PLD), followed by X-ray diffraction (XRD) for evaluation of film quality and crystallinity. Semi-c-IGZO shows the highest thermal conductivity, even higher than the most ordered crystal-like phase. After being stored in dry low-oxygen environment for months, a drastic decrease of semi-c-IGZO thermal conductivity was observed, while the thermal conductivity slightly reduced in c-IGZO and remained unchanged in a-IGZO. This change in thermal conductivity with storage time can be attributed to film structural relaxation and vacancy diffusion to grain boundaries.

scholarly journals Preparation of Whey-Based Banana Beverage and its Quality Evaluation

2021 ◽  
Vol 5 (01) ◽  
pp. 60-66
Author(s):  
Kunjal Shrestha ◽  
Abhishek Dahal
Keyword(s):  
Sensory Analysis ◽  
Room Temperature ◽  
Storage Time ◽  
Value Added ◽  
Body Color ◽  
Overall Acceptability ◽  
A Value ◽  
Banana Juice ◽  
Nutritional Qualities ◽  
The One

A value-added functional beverage was formulated utilizing unprocessed whey with excellent nutritional qualities and bland flavors; along with banana juice and the required amount of sugar. Five different formulations were prepared with varying proportions of whey, banana juice, and sugar. Sensory analysis was carried out for all five formulations and based on statistical analysis the one which showed the highest value for body, color, flavor, taste, and overall acceptability was selected for further analysis (85% liquid whey and 15% banana juice). The shelf-life of the final product was observed for 30 days at room temperature (25±5°C) and refrigerated temperature (7±1ºC). A significant variation in body, color, flavor, taste, and overall acceptability were observed by varying the composition of whey and banana juice (p<0.05). The beverage was pasteurized at 82.5°C for 20 min and stored at normal (25±5°C) and refrigerated (7±1°C) for 30 days. The effects of storage time and temperature on physicochemical (TSS, pH, acidity) and microbial (TPC, yeast & mold count) properties were evaluated. Out of five formulations, the one selected via sensory analysis had TSS of 12.4°Bx, total solids 14.21%, 0.302% acidity, pH 5.72, 5.087% reducing sugar, 0.53% protein, 0.56% ash, 0.87% crude fiber, 184.43mg potassium (mg/100gm) and 0.912mg vitamin C in 100 ml. The prepared beverage was stored for 30 days under refrigerated and normal conditions, and changes in TSS, pH and acidity were observed: 12.413.3%, 5.72-5.214, 0.32-0.43%, and 12.4-13.8%, 5.72-4.64, 0.32-0.68% respectively. Overall analysis showed that the beverage prepared with 85% liquid whey and 15% banana juice could be stored for 30 days under refrigerated conditions without the addition of preservatives.

Sign in / Sign up

Export Citation Format

Share Document