scholarly journals Does the Ratio of Compounds in a Plant Volatiles Blend Remain Stable During Transmission by Wind?

2021 ◽  
Author(s):  
Xiaoming Cai ◽  
Yuhang Guo ◽  
Lei Bian ◽  
Zongxiu Luo ◽  
Zhaoqun Li ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Wind Speed ◽  
Wind Tunnel ◽  
Plant Volatiles ◽  
Principal Component ◽  
Odor Source ◽  
Plant Volatile ◽  
Principal Component Analyses ◽  
Odor Plumes ◽  
Volatile Profiles

Abstract For plant volatiles to mediate interactions in tritrophic systems, they must convey accurate and reliable information to insects. However, it is unknown whether the ratio of compounds in plant volatile blends remains stable during wind transmission. In this study, volatiles released from an odor source were collected at different points in a wind tunnel and analyzed. The variation in the amounts of volatiles collected at different points formed a rough cone shape. The amounts of volatiles collected tended to decrease with increasing distance from the odor source. Principal component analyses showed that the volatile profiles were dissimilar among different collection points. The profiles of volatiles collected nearest the odor source were the most similar to the released odor. Higher wind speed resulted in a clearer distinction of the spatial distribution of volatile compounds. Thus, variations in the ratios of compounds in odor plumes exist even during transport over short distances.

scholarly journals The Spatial Distribution of Atmospheric Conditions, Severe Storms Zab Basin in Iran (A Case Study of Cut off Low Synoptic Pattern)

2015 ◽  
Vol 61 ◽  
pp. 39-45
Author(s):  
Nader Parvin ◽  
Emam Ali Asheri ◽  
Ebrahim Mesgari ◽  
Abdolla Ahmadi
Keyword(s):  
Spatial Distribution ◽  
Wind Speed ◽  
Weather Forecasting ◽  
Principal Component ◽  
Data Matrix ◽  
Atmospheric Conditions ◽  
Synoptic Pattern ◽  
Temporal And Spatial Distribution ◽  
Severe Storms ◽  
Synoptic Conditions

Atmospheric circulation patterns is the most important method of identification of environmental change that, it is useful For purposes such as weather forecasting, predict natural events (air pollution, floods, drought, etc). The aim of this study is to analyze the synoptic conditions of severe storms is Zab basin. Daily data of wind speed over the period 1364/01/01 to 1390/12/29 of three synoptic stations was taken from the department of meteorology. Given the scale of temporal and spatial distribution, wind speed and comprehensiveness of the three threshold size and calculate the 90th percentile wind speed, 40 days pervasive and severe storms were selected. Sea level pressure data on the network with a size 5.2°*5.2° that was located on Cornell 0-80 degrees east longitude and 0-80 degrees northern latitude from the database NCEP/NCAR were extracted. Matrix was formed in the dimensions of 40*864 with storm was on the rows and elevation data middle levels of the atmosphere, was on the columns. A principal component analysis was performed on data matrix elevation and six factors were identified that about 97.4% of the Pressure elevation changes of 500hp level was explained. To identify synoptic patterns, cluster analysis integration "ward's" was performed on these components.The results showed that, Cut off low synoptic pattern of the upper atmosphere with an abundance of 47.5% in May and December had the highest frequency. Irregularities in the movement and position of the polar vortex caused the jet stream and storm paths meridional winds greater control and troughs are driven towards the low latitudes deeper. As a result, the pressure gradient and energy exchange at its maximum reached compression Isobaric lines and Strong winds in the catchment area level has been created. All patterns are identified for the winds mainly from the west and southwest.

Extremely Gusty Winds from a Viewpoint of Aerodynamic Force

2020 ◽  
Author(s):  
Junji Maeda ◽  
Takashi Takeuchi ◽  
Eriko Tomokiyo ◽  
Yukio Tamura
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Rise Time ◽  
Aerodynamic Force ◽  
Step Function ◽  
Object Size ◽  
Aerodynamic Forces ◽  
Wind Force ◽  
Wind Observation

To quantitatively investigate a gusty wind from the viewpoint of aerodynamic forces, a wind tunnel that can control the rise time of a step-function-like gust was devised and utilized. When the non-dimensional rise time, which is calculated using the rise time of the gusty wind, the wind speed, and the size of an object, is less than a certain value, the wind force is greater than under the corresponding steady wind. Therefore, this wind force is called the “overshoot wind force” for objects the size of orbital vehicles in an actual wind observation. The finding of the overshoot wind force requires a condition of the wind speed recording specification and depends on the object size and the gusty wind speed.

scholarly journals Fast diffusion kurtosis mapping of human brain at 7 Tesla with hybrid principal component analyses

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Fangrong Zong ◽  
Jiaxin Du ◽  
Xiaofeng Deng ◽  
Xubin Chai ◽  
Yan Zhuo ◽  
...  
Keyword(s):  
Human Brain ◽  
Principal Component ◽  
7 Tesla ◽  
Fast Diffusion ◽  
Principal Component Analyses ◽  
Diffusion Kurtosis

scholarly journals Changes in Phenols, Polysaccharides and Volatile Profiles of Noni (Morinda citrifolia L.) Juice during Fermentation

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2604
Author(s):  
Zhulin Wang ◽  
Rong Dou ◽  
Ruili Yang ◽  
Kun Cai ◽  
Congfa Li ◽  
...  
Keyword(s):  
Octanoic Acid ◽  
Solid Phase ◽  
Principal Component ◽  
Hexanoic Acid ◽  
Morinda Citrifolia ◽  
Gas Chromatography Mass Spectrometry ◽  
Aroma Characteristics ◽  
Volatile Profiles ◽  
The Difference ◽  
Aroma Components

The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation process. The phenol and polysaccharide contents and aroma characteristics clearly changed according to fermentation scale and time conditions. The flavonoid content in noni juice gradually increased with fermentation. Seventy-three volatile compounds were identified by solid-phase microextraction coupled with gas chromatography–mass spectrometry (SPME-GC-MS). Methyl hexanoate, 3-methyl-3-buten-1-ol, octanoic acid, hexanoic acid and 2-heptanone were found to be the main aroma components of fresh and fermented noni juice. A decrease in octanoic acid and hexanoic acid contents resulted in the less pungent aroma in noni juice from factory-scale fermentation. The results of principal component analysis of the electronic nose suggested that the difference in nitrogen oxide, alkanes, alcohols, and aromatic and sulfur compounds, contributed to the discrimination of noni juice from different fermentation times and scales.

scholarly journals Aphid endosymbiont facilitates virus transmission by modulating the volatile profile of host plants

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiao-Bin Shi ◽  
Shuo Yan ◽  
Chi Zhang ◽  
Li-Min Zheng ◽  
Zhan-Hong Zhang ◽  
...  
Keyword(s):  
Host Plants ◽  
Green Peach Aphid ◽  
Virus Transmission ◽  
Feeding Preference ◽  
Plant Viruses ◽  
Volatile Profile ◽  
Cmv Infection ◽  
Buchnera Aphidicola ◽  
Plant Volatile ◽  
Volatile Profiles

Abstract Background Most plant viruses rely on vectors for their transmission and spread. One of the outstanding biological questions concerning the vector-pathogen-symbiont multi-trophic interactions is the potential involvement of vector symbionts in the virus transmission process. Here, we used a multi-factorial system containing a non-persistent plant virus, cucumber mosaic virus (CMV), its primary vector, green peach aphid, Myzus persicae, and the obligate endosymbiont, Buchnera aphidicola to explore this uncharted territory. Results Based on our preliminary research, we hypothesized that aphid endosymbiont B. aphidicola can facilitate CMV transmission by modulating plant volatile profiles. Gene expression analyses demonstrated that CMV infection reduced B. aphidicola abundance in M. persicae, in which lower abundance of B. aphidicola was associated with a preference shift in aphids from infected to healthy plants. Volatile profile analyses confirmed that feeding by aphids with lower B. aphidicola titers reduced the production of attractants, while increased the emission of deterrents. As a result, M. persicae changed their feeding preference from infected to healthy plants. Conclusions We conclude that CMV infection reduces the B. aphidicola abundance in M. persicae. When viruliferous aphids feed on host plants, dynamic changes in obligate symbionts lead to a shift in plant volatiles from attraction to avoidance, thereby switching insect vector’s feeding preference from infected to healthy plants.

Study on the Relation Between Side Ratios of Rectangular Cross Sections and Secondary Vortices at Trailing Edge in Motion-Induced Vortex Excitation

2017 ◽  
Author(s):  
Kazutoshi Matsuda ◽  
Kusuo Kato ◽  
Kouki Arise ◽  
Hajime Ishii
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Cross Sections ◽  
Leading Edge ◽  
Trailing Edge ◽  
Wind Speeds ◽  
Smoke Flow ◽  
Flow Visualizations ◽  
Institute Of Technology ◽  
Secondary Vortices

According to the results of conventional wind tunnel tests on rectangular cross sections with side ratios of B/D = 2–8 (B: along-wind length (m), D: cross-wind length (m)), motion-induced vortex excitation was confirmed. The generation of motion-induced vortex excitation is considered to be caused by the unification of separated vortices from the leading edge and secondary vortices at the trailing edge [1]. Spring-supported test for B/D = 1.18 was conducted in a closed circuit wind tunnel (cross section: 1.8 m high×0.9 m wide) at Kyushu Institute of Technology. Vibrations were confirmed in the neighborhoods of reduced wind speeds Vr = V/fD = 2 and Vr = 8 (V: wind speed (m/s), f: natural frequency (Hz)). Because the reduced wind speed in motion-induced vortex excitation is calculated as Vr = 1.67×B/D = 1.67×1.18 = 2.0 [1], vibrations around Vr = 2 were considered to be motion-induced vortex excitation. According to the smoke flow visualization result for B/D = 1.18 which was carried out by the authors, no secondary vortices at the trailing edge were formed, although separated vortices from the leading edge were formed at the time of oscillation at the onset wind speed of motion-induced vortex excitation, where aerodynamic vibrations considered to be motion-induced vortex excitation were confirmed. It was suggested that motion-induced vortex excitation might possibly occur in the range of low wind speeds, even in the case of side ratios where secondary vortices at trailing edge were not confirmed. In this study, smoke flow visualizations were performed for ratios of B/D = 0.5–2.0 in order to find out the relation between side ratios of rectangular cross sections and secondary vortices at trailing edge in motion-induced vortex excitation. The smoke flow visualizations around the model during oscillating condition were conducted in a small-sized wind tunnel at Kyushu Institute of Technology. Experimental Reynolds number was Re = VD/v = 1.6×103. For the forced-oscillating amplitude η, the non-dimensional double amplitudes were set as 2η/D = 0.02–0.15. Spring-supported tests were also carried out in order to obtain the response characteristics of the models.

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