scholarly journals Reaction of Apple Skin following UV Exposure

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 536B-536 ◽  
Author(s):  
Harold N. Fonda ◽  
John K. Fellman ◽  
X. Fan ◽  
J.P. Mattheis
Keyword(s):  
Room Temperature ◽  
Uv Light ◽  
Light Exposure ◽  
Short Wave ◽  
Apple Fruit ◽  
Uv Exposure ◽  
Temperature Dependent ◽  
C Storage ◽  
Fuji Apple ◽  
Atmosphere Storage

In order to investigate biochemical events occurring at the surface of apple skin, UV light exposure was used to generate a skin-browning reaction in apples. `Fuji' apple fruit that had been kept for 2 months in regular atmosphere storage at 0°C were exposed to short-wave UV light for 24 or 48 hr at 0°C or 23°C. After treatment, skin browning was monitored on fruit returned to 0°C storage or kept at room temperature under laboratory conditions. Fruit exposed to short-wave UV light at 0°C developed skin browning after 2 to 3 days at room temperature, whereas fruit held at 0°C did not show signs of skin browning until 7 days later. Short-wave UV exposure for 24 or 48 hr at 23°C resulted in skin browning that continued to develop on fruit kept at both room temperature and 0°C. When fruit were exposed to short-wave UV light for 72 hr at 0°C, a small amount of skin browning was already apparent. Long-wave UV light exposure for 48 hr had no observable effect on fruit treated at 0°C and then placed at room temperature. Our observations suggest that events that lead to browning are related to dispersion of energy absorbed by the hydrophobic molecules in the skin, a temperature dependent phenomenon.

Temperature and Light Effects on the Germination of Seven Native Forbs.

1991 ◽  
Vol 39 (3) ◽  
pp. 219 ◽  
Author(s):  
AJ Willis ◽  
RH Groves
Keyword(s):  
Gibberellic Acid ◽  
Room Temperature ◽  
Temperature Dependent ◽  
Short Term ◽  
C Storage ◽  
Seasonal Factors ◽  
Natural Grasslands ◽  
Eastern Australia ◽  
Initial Basis ◽  
Light Effects

Seeds of seven native herbaceous species common in natural grasslands and woodlands of south-eastern Australia were tested for germination over a range of alternating temperatures (15/5-35/25°C) with and without light. Seeds were also exposed to low (4°C) and high (50/40°C) temperatures and the addition of gibberellic acid. Tests were conducted on seeds stored for 0-15 months at room temperature. The optimum temperature for germination differed among species, with only Helipterum albicans germinating maximally over all temperatures. Germination of Bulbine bulbosa seed was the most strongly temperature-dependent. Light and cold treatments promoted germination in Helipterum albicans and Vittadinia muelleri only. Short-term dormancy (3-4 months) was shown to occur in fresh seeds of Stylidium graminifolium, Helichrysum apiculatum and Wahlenbergia stricta, but not in seeds of the other species; addition of gibberellic acid to seeds of the two last-named species did not overcome that dormancy. Seeds of all species remained germinable after 15 months of storage. Seeds of most species germinated maximally at 20/10°C. Storage at high alternating temperatures for 1 month inhibited subsequent germination at 30/20° in Leptorhynchos squamatus and S. graminifolium but increased it in V. muelleri, H. albicans and H. apiculatum. In the last species, exposure of 1-month-old seeds to high temperature broke dormancy. These results show that germination and dormancy of seeds of a range of native forbs vary with temperature and light regime; they provide an initial basis on which to test and interpret the effects of seasonal factors on germination and field establishment.

scholarly journals Graphene Schottky Junction on Pillar Patterned Silicon Substrate

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 659 ◽  
Author(s):  
Giuseppe Luongo ◽  
Alessandro Grillo ◽  
Filippo Giubileo ◽  
Laura Iemmo ◽  
Mindaugas Lukosius ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Room Temperature ◽  
Light Exposure ◽  
Photovoltaic Effect ◽  
Reverse Current ◽  
Charge Carriers ◽  
Graphene Monolayer ◽  
Temperature Dependent ◽  
Thermal Generation ◽  
Photo Response

A graphene/silicon junction with rectifying behaviour and remarkable photo-response was fabricated by transferring a graphene monolayer on a pillar-patterned Si substrate. The device forms a 0.11 eV Schottky barrier with 2.6 ideality factor at room temperature and exhibits strongly bias- and temperature-dependent reverse current. Below room temperature, the reverse current grows exponentially with the applied voltage because the pillar-enhanced electric field lowers the Schottky barrier. Conversely, at higher temperatures, the charge carrier thermal generation is dominant and the reverse current becomes weakly bias-dependent. A quasi-saturated reverse current is similarly observed at room temperature when the charge carriers are photogenerated under light exposure. The device shows photovoltaic effect with 0.7% power conversion efficiency and achieves 88 A/W photoresponsivity when used as photodetector.

Strength Properties of Flexible Geogrids Under Indoor and Outdoor Ultraviolet Exposure

2003 ◽  
Vol 1849 (1) ◽  
pp. 221-230 ◽  
Author(s):  
Chiwan Wayne Hsieh ◽  
Chien Kuei Lin
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Carbon Black ◽  
Uv Light ◽  
Light Exposure ◽  
Outdoor Exposure ◽  
Uv Exposure ◽  
Fluorescent Light ◽  
Exposure Condition ◽  
Coating Materials

The outdoor ultraviolet (UV) light exposure program according to ASTM D5970 and the indoor UV fluorescent lamp device according to ASTM G154 were used to evaluate the UV degradation in test polyester geogrids. Eighteen months’ worth of data were obtained from the outdoor program. UV-A-340 lamps and exposure condition No. 7 were used for the indoor program. The outdoor exposure program was conducted at Pingtung, in southern Taiwan. The annual sunlight exposure energy was 4,263.50 MJ/m2. The accumulated annual UV-A and UV-B energies were 256.56 and 0.83 MJ/m2, respectively. The tensile strength of the test geogrids decreased as the outdoor exposure increased, but the decrease in the rate of tensile strength also lessened as UV exposure increased. Carbon black and antioxidants contained in the coating materials have a significant influence on the rate of degradation for the test geogrids; 2% carbon black and 1% antioxidant by weight are recommended. The proportions of average retained ultimate tensile strength for 1 month, 12 months, and 18 months of outdoor exposure were 88%, 71%, and 66%, respectively. The tensile strength half-life cycle due to UV exposure was greater than 18 months. Similar behavior was also observed for the elongation at break. However, no clear trend was found for strength at 5% strain due to UV exposure. The reduction factors due to 18 months of outdoor exposure varied from 1.27 to 1.99. The average reduction factor was about 1.60. The reduction in ultimate tensile strength under 180 h of UV exposure in the indoor UV exposure test program was very significant. However, the rate of lost tensile strength for the second and third 180-h UV exposure was very small. The average retained tensile strengths for the geogrids under 180-h and 540-h exposures were 81% and 77%, respectively. The effect of 540-h fluorescent light exposure on the tensile strength of polyester geogrids coated with polyvinyl chloride was equivalent to 151 days of outdoor exposure at Pingtung.

scholarly journals Inhibition of Polyimide Photodegradation by Incorporation of Titanate Nanotubes into a Composite

2020 ◽  
Author(s):  
Christian Harito ◽  
Dmitry V Bavykin ◽  
Brian Yuliarto ◽  
Hermawan K Dipojono ◽  
Frank C Walsh
Keyword(s):  
Methylene Blue ◽  
Raman Spectroscopy ◽  
Brittle Material ◽  
Uv Light ◽  
Light Exposure ◽  
Polymer Chains ◽  
Plasticity Index ◽  
Uv Exposure ◽  
Spectroscopy Optical ◽  
Positively Charged

The effect of UV light exposure on the properties of hexafluoroisopropylidene-diphthalic anhydride–oxydianiline (6FDA–ODA) polyimide (PI) and polyimide–titanate nanotube (TiNT/PI) composites has been studied using Raman spectroscopy, optical microscopy, nanoidentation and TEM. The degree of polymer photodegradation was estimated by measuring the change in affinity to a positively charged dye (methylene blue, MB). The mechanism of photoassisted transformations in polyimides usually involves scission of polymer chains accompanied by appearance of active radicals, which undergo further rapid transformations to more stable phenol, amine, and carboxylic functional groups. The accumulation of these groups can increase the degree of adsorption of charged dyes in the photodegraded polymer. It was found that neat PI showed a significantly increased capacity to adsorb MB after irradiation with UV, reaching a plateau after 1 h. In contrast, TiNT/PI composite demonstrated a much slower rise in concentration of adsorbed MB even after 4 h of UV exposure. Raman spectra indicated cleavage of C=O and C–F bonds in PI while only the C–F bond was damaged in TiNT/PI. Shorter cracks (≈ 40 µm long) appeared in TiNT/PI composites whereas macro cracks (> 100 µm) were visible in neat PI after 3 h of UV exposure. Brittleness was studied by comparing plasticity index which varied from 0 to 1 (0 corresponding to the most brittle material and 1 the most ductile one). Plasticity index reduced by 51% and 2% for PI and TiNT/PI, respectively after 3 h UV irradiation, indicating that TiNT can protect underlying PI from further damage. The hardness of neat PI decreased whereas, for TiNT/PI, it increased under UV, suggesting crosslinking of broken polymer chains with nanotubes.

scholarly journals Preharvest Applications of Sprayable 1-methylcyclopropene in the Orchard for Management of Apple Harvest and Postharvest Condition

HortScience ◽  
2007 ◽  
Vol 42 (5) ◽  
pp. 1192-1199 ◽  
Author(s):  
Don C. Elfving ◽  
Stephen R. Drake ◽  
A. Nathan Reed ◽  
Dwayne B. Visser
Keyword(s):  
Room Temperature ◽  
Titratable Acidity ◽  
Apple Fruit ◽  
Soluble Solids ◽  
Ethylene Concentration ◽  
Flesh Firmness ◽  
Solids Concentration ◽  
Commercial Harvest ◽  
Temperature Application ◽  
Atmosphere Storage

A sprayable formulation of 1-methylcyclopropene (1-MCP; AgroFresh, Spring House, PA) was applied to ‘Scarletspur Delicious’ and ‘Cameo’ apples in the orchard 1 to 3 weeks before harvest and compared in different postharvest studies with the commercial postharvest 1-MCP fruit treatment (SmartFresh; AgroFresh) and with aminoethoxyvinylglycine (AVG; ReTain; Valent BioSciences, Walnut Creek, CA). Treated apples were held in air storage for 50 to 60 d or in controlled-atmosphere storage for 120 to 125 or 215 to 225 d. With increased concentration, sprayable 1-MCP treatments were effective at controlling flesh firmness loss and internal ethylene concentration (IEC) up to 225 d of storage as well as during a 7-d poststorage shelf life simulation at room temperature. Application closer to harvest improved the effect of sprayable 1-MCP on control of flesh firmness loss and IEC. Concentrations of sprayable 1-MCP above 90 mg a.i./L produced similar fruit effects to 1-MCP. Treatment with 1-MCP showed little effect on soluble solids concentration (SSC), titratable acidity (TA), or skin or flesh color in ‘Delicious’ but slightly increased SSC and TA in ‘Cameo’ apples. AVG applied 4 weeks before commercial harvest controlled IEC nearly as well as either sprayable 1-MCP or 1-MCP during storage, but AVG-treated fruit allowed to ripen for 7 d at room temperature after storage lost much more flesh firmness regardless of storage regime. Sprayable 1-MCP also reduced starch hydrolysis, IEC and fruit drop at harvest. Sprayable 1-MCP may offer new opportunities for effective preharvest management of apple fruit condition, storability, and poststorage fruit quality.

Cotton Reinforced Biopolymer Matrix Composite: Effect of Ultraviolet (UV) on its Mechanical Properties

2011 ◽  
Vol 471-472 ◽  
pp. 928-932
Author(s):  
Ahmad Zuraida ◽  
Hazleen Anuar ◽  
Zahurin Halim ◽  
Dayang Laila Abang Abdul Majid ◽  
M. Yusof Fauziah
Keyword(s):  
Morphological Study ◽  
Room Temperature ◽  
Uv Light ◽  
Raw Materials ◽  
Natural Fibers ◽  
Uv Exposure ◽  
Composite Effect ◽  
Renewable Raw Materials ◽  
Sem Micrograph ◽  
Matrix Loss

Research on the production of composites from natural fibers has an enormous attention from researchers due to environmental awareness, which focusing to produce compostable bio-based composites and renewable raw materials that can be safely disposed after their use without polluting the environment. This paper reports the study on the effect of the ultraviolet (UV) to the cotton/albumen composites (CAC). The CAC were prepared by using hands lay-up technique with 10 w/w % of cotton content and cured at room temperature for 14 days. The cured samples were cut before exposing to UV light up to 20 days. The increase in tensile strength was observed up-to 10 days of exposure before it is decreasing to about 15% after 20 days of exposure to UV. The morphological study through SEM micrograph shows that fibers breakage and the biopolymer matrix loss is more with longer duration of UV exposure.

scholarly journals Association among pterygium, cataracts, and cumulative ocular ultraviolet exposure: A cross-sectional study in Han people in China and Taiwan

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253093
Author(s):  
Natsuko Hatsusaka ◽  
Naoki Yamamoto ◽  
Hisanori Miyashita ◽  
Eri Shibuya ◽  
Norihiro Mita ◽  
...  
Keyword(s):  
Uv Light ◽  
Light Exposure ◽  
Cross Sectional Study ◽  
Classification Systems ◽  
Uv Exposure ◽  
Cross Sectional ◽  
High Prevalence ◽  
Surface Disorder ◽  
Progress Rate ◽  
Ocular Surface Disorder

Purpose Pterygium is an ocular surface disorder mainly caused by ultraviolet (UV) light exposure. This study explored the relationships between six cataract types with pterygium and UV exposure. Methods We have previously studied cataracts in residents of three regions in China and Taiwan with different UV intensities. From that study, we identified 1,547 subjects with information on the presence or absence of pterygium. Pterygium severity was graded by corneal progress rate. Cataracts were graded by classification systems as three main types (cortical, nuclear, posterior subcapsular) and three subtypes (retrodots, waterclefts, fiber folds) with high prevalence in middle-aged and elderly people. We calculated the cumulative ocular UV exposure (COUV) based on subject data and National Aeronautics and Space Administration data on UV intensities and used logistic regression to calculate odds ratios for the associations of COUV, cataract, and pterygium. Results We found an overall pterygium prevalence of 23.3%, with significant variation among the three regions. Four cataract types (cortical, nuclear, posterior subcapsular, and retrodots) were significantly associated with the presence of pterygium. Conclusions There was a significant association between COUV and pterygium, indicating that COUV is associated with the risk of pterygium development and that pterygium is useful as an index of UV exposure. Furthermore, the type of cataract in eyes with pterygium may indicate the level of UV exposure.

scholarly journals Evaluation of Physiological and Orgaleptic Properties of Mango cv. Kesar as Influenced by Ionizing Radiation and Storage Temperature

2014 ◽  
Vol 11 (2) ◽  
pp. 69-80 ◽  
Author(s):  
MK Yadav ◽  
NL Patel ◽  
BR Parmar ◽  
Dileswar Nayak
Keyword(s):  
Gamma Rays ◽  
Storage Temperature ◽  
Short Wave ◽  
Physiological Changes ◽  
Radiation Processing ◽  
Overall Acceptability ◽  
C Storage ◽  
And Control ◽  
Atmosphere Storage ◽  
And Storage

Radiation processing of fruits involves exposure to short wave energy to achieve a specific purpose to maintain the physiological changes and sensory quality of the product. The effect of gamma irradiation and storage temperature on physiological changes and organoleptic properties of mango fruit var. Kesar was studied. The fruits were exposed to gamma radiation at different doses i.e. 0.00kGy, 0.20kGy, 0.40kGy and 0.60kGy from the radio isotope 60Co and stored at different storage environments i.e. at ambient storage (27±2°Cwith 60-70% RH); at 9°C with 90% RH; at 12°C with 90% RH and control atmosphere storage ( at 12°C, O2 2%, CO2 3% and RH 90%). The fruits irradiated with 0.40kGy gamma rays and stored at 9°C storage temperature with 90% RH recorded maximum reduction in physiological loss in weight and reduced ripening. The minimum physiological loss in weight and ripening and highest marketability of fruits was recorded from fruits irradiated with 0.40kGy gamma rays and stored at 12°C storage temperature with 90 RH including maximum scores on skin colour, pulp colour, texture, taste and overall acceptability at the end of shelf life (41.43 days). DOI: http://dx.doi.org/10.3329/sja.v11i2.18403 SAARC J. Agri., 11(2): 69-80 (2013)

scholarly journals Temporal Relationship between Ethylene and Ester Production during Maturation of Apple Fruit

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 536C-536
Author(s):  
J.P. Mattheis ◽  
D.A. Buchanan ◽  
J.K. Fellman
Keyword(s):  
Fruit Ripening ◽  
Fruit Development ◽  
Apple Fruit ◽  
Ethylene Concentration ◽  
Major Transition ◽  
Apple Cultivars ◽  
Fuji Apple ◽  
Harvest Maturity ◽  
Atmosphere Storage ◽  
The Relationship

Quantitative and qualitative changes in net production of volatile compounds by apples occurs during fruit development with a major transition to ester production occurring as fruit ripening begins. Ester production during fruit ripening is an ethylene-mediated response; however, differences in maturation patterns among apple cultivars led us to examine the relationship between ester production and onset of the ethylene climacteric in several commercial apple cultivars. Emission of volatile esters as a function of apple fruit development was evaluated for `Royal Gala', `Bisbee Delicious', `Granny Smith', and `Fuji' apple fruit during two harvest seasons. Apples were harvested weekly and analyses of harvest maturity were performed the day after harvest. Non-ethylene volatiles were collected from intact fruit using dynamic headspace sampling onto Tenax traps. Fruit from each harvest was stored at 1°C in air for 5 months (3 months for `Royal Gala') plus 7 days ripening at 20°C, then apples were evaluated for the development of disorders. The transition to ester production occurred after internal ethylene exceeded 0.1 μL for `Royal Gala', `Bisbee Delicious', and `Fuji'. Ester emission by `Granny Smith' apples remained low throughout the harvest period. Increased ester emission occurred after the optimum harvest date (as determined by the starch index and internal ethylene concentration) for controlled-atmosphere storage of `Bisbee Delicious' and prior to optimum maturity for `Royal Gala' and `Fuji'. A relationship between the potential for development of superficial scald and ester production at harvest was evident only for `Bisbee Delicious' apples.

(111) Monocrystalline Nickel Films

1972 ◽  
Vol 30 ◽  
pp. 512-513
Author(s):  
T.E. Pratt ◽  
R.W. Vook
Keyword(s):  
Film Thickness ◽  
Deposition Rate ◽  
Room Temperature ◽  
Narrow Range ◽  
High Vacuum ◽  
Residual Pressure ◽  
Temperature Dependent ◽  
Deposition Parameters ◽  
Transmission Electron ◽  
Substrate Temperatures

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

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