• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.149-155
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• 2006

This study was carried out to investigate effects of different night temperature treatments during nursery period on flower bud differentiation and growth of pepper cv. Cheongyang. Number of leaves, top fresh weight and top dry weight of pepper seedlings were increased with increasing the night temperature during nursery periods. And also flower bud differentiation and days to flowering were accelerated as increasing the night temperature. Plant height, stem diameter, branch length and intermode length of pepper after transplanting were height at the low night temperature ($28/11^{\circ}C$), but they were retarded at the high night temperature ($28/21^{\circ}C$) treatment. Number of lateral branches was significantly reduced at the high night temperature, but there was no a regular tendency in branching habit of the main stem by temperature treatments. Seedling growth before transplanting was retarded at the low night temperature but gradually recovered after transplanting into the plastic house. However, seedling growth at the high night temperature was shown in contrast to above response of the low night temperature.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.264-270
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• 2015

Tropical night phenomenon has been increasing due to global warming recently, it is expected that fruit quality of apples will decrease due to elevated night temperature condition. In the present study, fruit quality at maturity, periodic anthocyanin biosynthetic gene expression and sugar contents in leaves and fruit flesh were investigated to establish the physiological responses of 'Fuji' apples under high night temperature. The night temperature were treated with such as ambient (control), ambient $-4^{\circ}C$, and ambient $+4^{\circ}C$. After the treatment, high night temperature didn't affect fruit diameter, weight, and soluble sugar contents. Coloration of ambient $+4^{\circ}C$ was poor than that of control, however there was no significant difference between these genes expression of control and that of ambient $+4^{\circ}C$ treatment in the late coloration season. Increase of sorbitol and glucose contents at ambient $+4^{\circ}C$ in leaves were smaller than those at control, and then sorbitol and sucrose contents in fruit flesh at ambient $+4^{\circ}C$ were smaller than those at control. The cross section of leaves showed that there were no differences with the structure of parenchyma and epidermis tissues between the treatments, but starch granules in the palisade parenchyma cells decreased in high night temperature treatments. Consequently, high night temperature didn't affect the fruit quality, but changed sugar contents in leaves and fruit flesh, and suppressed coloration regardless of anthocyanin biosynthetic gene expression.

• Current Research on Agriculture and Life Sciences
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• v.31 no.1
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• pp.61-64
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• 2013

This study identified the effect of night time temperatures on the flowering period of spray-chrysanthemum during the summer season in South Korea. According to the results for 2005, the temperature at night time sustained more than $25^{\circ}C$ for 23.6 days during the short day period and delayed the flowering period for 22 days. Similar observations were reported in 2006, as the night time temperature sustained more than $25^{\circ}C$ for 23.6 days during the short day period and delayed flowering period for 23 days. The results for 2007 year showed that night time temperature sustained more than $25^{\circ}C$ for 31.9 days during the same period and delayed flowering for 31 days. In conclusion, based on the results for 2005 to 2007, a specific correlation was found between high night time temperatures and a delayed flowering period for the 'Euro' spray-chrysanthemum.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.349-355
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• 2021

The effect of night temperature was investigated on mango (Mangifera indica cv. Irwin) for setting appropriate night temperature and managing mango cultivation in a greenhouse. Different night temperatures (10, 15, and 20℃) were treated from budding to fruit development in mango trees. As night temperature increased, the initiation of flowering, full blooming, fruiting, and fruit development tended to be accelerated. There were no significant differences in the growth of shoots flushed after the fruit harvest among trees treated with different night temperatures. The lengths of the flower stalk were the shortest at 10℃ of night temperature; however, there were no significant differences between 15℃ and 20℃ of the night temperature. The length, diameter, and weight of mango fruits were higher at 15℃ and 20℃ than 10℃. Soluble solid contents and acidities showed no difference; the firmness and skin color were better as the night temperature increased. Accordingly, setting the minimum night temperatures to 15℃ or 20℃ can increase the number of fruits and produce high-quality fruits when cultivating mango in the greenhouse. Even the minimum night temperature to 15℃ can reduce heating costs in the greenhouse.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.236-242
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• 2012

We investigated the influences of night interruption (NI) and night temperature on flowering and flower coloration in Cymbidium. Cymbidium 'Red Fire' and 'Yokihi' were grown under a 9 hours photoperiod (control), a 9 hours photoperiod with NI at a low light intensity (LNI) of 3-7 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, or a 9 hours photoperiod with NI at a high light intensity (HNI) of 120 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for four hours (22:00-02:00 HR) for 16 weeks during the reproductive growth stage (Experiment 1). Thirty month-old Cymbidium 'Red Fire' plants with initiated flowering buds were placed in four different growth chamber with night temperature set points of 6, 9, 12, or $15^{\circ}C$ for 16 hours (18:00 to 09:00 HR) and a daytime temperature of $25^{\circ}C$ (Experiment 2). In Experiment 1, the numbers of visible buds and flowers increased, and time to flowering decreased in both the LNI and HNI treatments, as compared to the control in both cultivars. Red color in Cymbidium 'Red Fire' increased by both LNI and HNI, as evidenced by an increased $a^*$ in plants grown under these conditions, relative to those grown under the control condition. Number of days to visible buds at 9-$15^{\circ}C$ ranged from 31-34 days, as compared to 39 days at $6^{\circ}C$ in Experiment 2. Although as the temperature increased days to flowering decreased when the plant was grown at $15^{\circ}C$ as compared to 6, 9, or $12^{\circ}C$, the red color ($a^*$) also decreased. The number of flowers and percent flowering increased when the night temperature was maintained higher than $9^{\circ}C$. Therefore, NI treatment and maintaining the night temperature at approximately 9-$12^{\circ}C$ during the winter season after flower spike initiation in the reproductive developmental growth stage improve flower quality and controls flowering time.

• Journal of the Korea Safety Management & Science
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• v.10 no.2
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• pp.53-60
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• 2008

A test was conducted using two high density discharge lamps, the H2D and the structurally new H4D. They were tested for luminous illumination and luminous temperature in the day and night time. The test was conducted without crippling the performance of the H2D by adding a magnetic actuator, enabling it to move left to right, and up and down. By making these modifications we constructed a sample of the H4D. We compared the H2D and the H4D sample's luminous illumination and luminous temperature by using a photometer and a digital thermometer in the day and night time. We discovered that the H2D and H4D performed similarly from the data we gathered. Now we know the H4D has potential use and extensive research needs to be made to gather more detailed data.

• Journal of Environmental Science International
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• v.16 no.5
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• pp.593-602
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• 2007

The frequency of tropical nights and tropical days in Busan during summer season (June-August) from 1995 to 2004 were investigated. When air temperature higher than $25^{\circ}C$ continuously maintains at night in summer, it is called the occurrence of tropical night. Tropical day is defined that maximum air temperature is higher than $30^{\circ}C$, In Jin-Gu and Daeyeon-dong shows a lot of frequency of tropical day and tropical night because there were located in downtown. Relatively, the areas where are located in seaside and riverside show very low frequency. This can be explained the cooling effects of sea and river. The main meteorological characteristics during tropical nights and tropical days is proved pattern of reverse tendency through wind rose. We analyzed heat index and discomfort index during tropical night and tropical day. This study is useful to understand the aspect of urban thermal environment but need some more observation to quantify.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.25-31
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• 2012

This study aimed to investigate the effect of night temperature on the productivity, growth, and fruit characteristics of tomatoes and set the optimal night air temperature. Tomatoes (Solanum lycopersicum Mill. cv. Superdoterang and cv. Rapito) were grown at 5, 10, 15, and $20^{\circ}C$ during night time and ventilation temperature point during day time set $27^{\circ}C$. Depending on night air temperature, plant height, leaf area, fresh and dry weight of each organ, leaf, stem, and root were changed. Condition of high night temperature resulted in promotion of tomatoes growth with high dry weight and fresh weight. However, the dry weight under night temperature $20^{\circ}C$ decreased, especially, in 'Superdoterang'. On changes of yield, 'Rapito' showed higher productivity than 'Superdoterang' and the highest productivity point for nigh temperature is $13.32^{\circ}C$ for 'Superdoterang' and $14.25^{\circ}C$ for 'Rapito'. Although the total yield decreased from the point, the daily productivity increased with increasing night temperature, the highest point for nigh temperature is $14.45^{\circ}C$ for 'Superdoterang' and $16.46^{\circ}C$ for 'Rapito'. High temperature deceased the fruit weight and increased total soluble solid content in fruits. It is concluded that the night air temperature changes productivity of tomato and the temperatures between productivity and growth velocity have differences depending on different cultivars. scores than the other beef jerky samples (p<0.05).

• Science of Emotion and Sensibility
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• v.20 no.4
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• pp.135-142
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• 2017

In the present study, we investigated the physiological effects of smartphone use at night when the display luminance and white balance were differently manipulated. Two levels of luminance and two types of white balance were combined to form four types of displays. Subjects were instructed to use smartphones between 23:00 to 01:00 twice a week for two weeks, and for each trial, subjects were given one of the four display types. Melatonin concentration in the saliva, body temperature and heart rate were measured before and after each experiment. The experimental result showed that the low luminance display supported melatonin secretion and thermoregulation compared to the high luminance display. With regard to the white balance, higher melatonin level was observed when using the display that filtered blue light. The low luminance display together with yellowish tint best supported restful sleep at night in terms of every physiological response. This study collectively demonstrates that bright and blue light emitted from smartphone displays adversely affect melatonin secretion, body temperature, and heart rate, and therefore, suggests the use of a display with low luminance or a display that filters blue light for a restful sleep at night.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.11
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• pp.421-427
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• 2016

The indoor temperature of a building increases during the day due to solar radiation. This behavior is significant in school buildings that are finished with high thermal capacity materials. Moreover, in school buildings, windows cannot be opened until the class has finished owing to the security policy of schools. Consequently, classrooms maintain a high temperature throughout the morning. It is thus important to remove the indoor heat before the commencement of classes in order to reduce the cooling energy needed. The Energy Recovery Ventilator (ERV) system is currently being installed in school buildings for ventilating the classrooms. Night-purge control using ERV can be a good strategy to cool the classroom in advance of the operation of the cooling system. However, the optimal operation method of the ERV for night-purge control has not yet been reported. In this study, the effect of night-purge control with ERV in school buildings is analyzed by simulation method. The results of this study showed that the energy saving effect of night-purge control with ERV is most effective in the case of 2 hours operation prior to the commencement of the first lass and when enthalpy based outdoor air cooling is used.