China
Africa
Explore chapters and articles related to this topic
Procedures of Structural Appraisal
Published in Poul Beckmann, Robert Bowles, Structural Aspects of Building Conservation, 2012
If one were to take hourly readings with a sufficiently accurate instrument, one would get a plot showing the diurnal variations. If the readings were continued over a year one would see the diurnal variations superimposed on annual movements, but over several years there would be no total movement in one direction or another from ‘seasonal fluctuations’.
Recent spatial gradients and time trends in Dhaka, Bangladesh, air pollution and their human health implications
Published in Journal of the Air & Waste Management Association, 2019
Md Mostafijur Rahman, Shakil Mahamud, George D. Thurston
The diurnal patterns of pollution concentration were analyzed in this study based on 2017 data only, as we have no hourly data available for 2013–2016. A strong diurnal pattern was detected at all three sites (Figure 6, Figure S1, and Figure S2). Other than ozone, pollutants (PM2.5, PM10, SO2, NO2, NOx, NO, and CO) monitored at three sites followed the same diurnal pattern, in which the peak pollution concentrations were observed at night, between 10 p.m. and 9 a.m. The peak ozone pollutant concentrations were found between 2 p.m. and 8 p.m. This is consistent with other studies, because ozone formation is instead usually at a maximum in the middle of the day, when the sunlight is most direct (Masiol et al. 2017). Diurnal variations are governed by interplays among the pollution sources, photochemical processes, and weather factors. The diurnal variation of wind in Figure S9 shows that wind speed is way higher during the daytime between 9 a.m. and 6 p.m., with peak at 3 p.m., and lowest at 12 a.m. High pollution concentrations measured between 10 p.m. and 9 a.m. could result from the local rules on traffic flow in Dhaka (as the diesel-powered buses and freight trucks can use the Dhaka City route only at night, between 8 p.m. and 6 a.m.), low mixing height during the night (Geiß et al. 2017), and low wind speed during this time span (Figure S9). Long-route buses and any kind of heavy-duty diesel trucks are barred from using any highway inside Dhaka during the daytime (Transport and Board 2011).
Qualitative characteristics of hyssop (Hyssopus officinalis L.) under the influence of harvest time and drying methods
Published in Drying Technology, 2022
Farzaneh Jangi, Mohammad-Taghi Ebadi, Mahdi Ayyari
These results may be related to diurnal changes in environmental factors such as light, relative humidity and temperature.[43] Numerous researchers have also stated that the amount of EO increases around noon, when the maximum intensity of sun radiation and the reduction of relative humidity occurs.[32,34,40,52,53] For example, the effects of light as promoter on 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) activity, a key enzyme in the biosynthesis cycle of terpenes, has been documented and also the light-mediated alteration in HMGCR transcripts.[54] Also, Rodrìguez-Concepción[55] suggested about the light-dependent regulation of terpenoid biosynthesis during the early stages of development in Arabidopsis thaliana. In Artemisia annua, the discharging of β-pinene fluctuates as per the rhythm of day as well as night and it is higher in the day light than night.[56] The all terpenoid compounds of Arabidopsis thaliana flowers showed clear diurnal emission patterns.[57] However, some researchers believe that in the case of EO-bearing plants, the type of plant species and its reaction to environmental factors is very important, so that in some aromatic plants, the amount of EO is higher in the early morning and in others, at noon or night.[51] In relation to the EO components, the interaction of their biosynthesis cycle with environmental factors causes changes at different hours of the day.[45] These diurnal trends appear to be more than just a random variation but it is more complex than can be explained by simple environmental factors.[52] The environmental factors (temperature, humidity, sunlight intensity and duration of lighting period) are interdependent and affect each other. Therefore, it is very difficult to determine the independent role of each factor in the production of plant secondary metabolites.[58]