scholarly journals Shock-heated radiation-driven outflows as a solution to the weak-wind problem of late O-type stars

2021 ◽  
Author(s):  
C. Lagae ◽  
F. A. Driessen ◽  
L. Hennicker ◽  
N. D. Kee ◽  
J. O. Sundqvist
Keyword(s):  
Weak Wind

Autonomous energy supply based on the wind-energy complex and hydrogen energy storage

2019 ◽  
pp. 12-26
Author(s):  
S. I. Nefedkin ◽  
A. O. Barsukov ◽  
M. I. Mozgova ◽  
M. S. Shichkov ◽  
M. A. Klimova
Keyword(s):  
Wind Speed ◽  
Wind Energy ◽  
Power Supply ◽  
Energy Supply ◽  
Heat Supply ◽  
Hot Water ◽  
Successful Implementation ◽  
High Wind ◽  
Wind Generators ◽  
Weak Wind

The paper proposes an alternative scheme of guaranteed electricity and heat supply of an energy-insulated facility with a high potential of wind energy without the use of imported or local fuel. The scheme represents a wind power complex containing the park of wind generators located at the points with high wind potential. The wind generators provide guaranteed power supply even in periods of weak wind. For heat supply of the consumer, all surplus of the electric power goes on thermoelectric heating of water in tanks of accumulators, and also on receiving hydrogen by a method of electrolysis of water. The current heat supply is carried out with the use of hot water storage tanks, and the heat supply during the heat shortage is carried out by burning the stored hydrogen in condensing hydrogen boilers. We have developed the algorithm of calculation and the program "Wind in energy" which allows calculating annual balance of energy and picking up necessary quantity of the equipment for implementation of the scheme proceeding from the annual schedule of thermal and electric loading, and also potential of wind energy in the chosen region. The calculation-substantiation of the scheme proposed in relation to the real energy-insulated object Ust-Kamchatsk (Kamchatka) is carried out. The equipment for the implementation of an alternative energy supply scheme without the use of imported fuel is selected and compared with the traditional energy supply scheme based on a diesel power plant and a boiler house operating on imported fuel. With the introduction of an alternative power supply scheme, the equipment of the traditional scheme that has exhausted its resource can be used for backup power supply. Using climate databases, a number of energy-insulated facilities in the North and East of Russia with high wind energy potential are considered and the conditions for the successful implementation of the energy supply scheme are analyzed. This requires not only a high average annual wind speed, but also a minimum number of days of weak wind. In addition, it is necessary that the profile of the wind speed distribution in the annual section coincides with the profile of the heat load consumption.

scholarly journals Formation of Conidial Pseudochains by Tomato Powdery Mildew Oidium neolycopersici

Plant Disease ◽  
2006 ◽  
Vol 90 (7) ◽  
pp. 915-919 ◽  
Author(s):  
W. Oichi ◽  
Y. Matsuda ◽  
T. Nonomura ◽  
H. Toyoda ◽  
L. Xu ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Powdery Mildew ◽  
Critical Level ◽  
Oidium Neolycopersici ◽  
Ambient Relative Humidity ◽  
Digital Microscope ◽  
Tomato Powdery Mildew ◽  
A Chain ◽  
Weak Wind ◽  
Generative Cells

The formation of conidial pseudochains by the tomato powdery mildew Oidium neolycopersici on tomato leaves was monitored using a high-fidelity digital microscope. Individual living conidiophores that formed mature conidial cells at their apex were selected for observation. The conidial cells were produced during repeated division and elongation by the generative cells of the conidiophores. Under weak wind conditions (0.1 m/s), these conidial cells did not separate from each other to produce a chain of conidial cells (pseudochain). The pseudochains dropped from the conidiophores once four conidial cells were connected. The conidiophores resumed conidium production, followed by another cycle of pseudochain formation. The formation of pseudochains by tomato powdery mildew was not influenced by the ambient relative humidity. On the other hand, the conidial cells produced were easily wind dispersed without forming pseudochains when conidiophores were exposed to stronger winds (1.0 m/s). The present study successfully demonstrated that the pathogen required wind to disperse progeny conidia from the conidiophores and produced conidial pseudochains when the wind was below a critical level, independent of high relative humidity as reported previously.

scholarly journals Mean Structure of the Nocturnal Boundary Layer under Strong and Weak Wind Conditions: EPRI Case Study

2003 ◽  
Vol 42 (7) ◽  
pp. 952-969 ◽  
Author(s):  
T. B. P. S. Rama V. Krishna ◽  
Maithili Sharan ◽  
S. G. Gopalakrishnan ◽  
Aditi
Keyword(s):  
Boundary Layer ◽  
Nocturnal Boundary Layer ◽  
Mean Structure ◽  
Weak Wind

Observed features of the water masses in the Halmahera Sea in November 2016

2021 ◽  
Vol 26 (4) ◽  
pp. 225-236
Author(s):  
Mochamad Riza Iskandar ◽  
Adi Purwandana ◽  
Dewi Surinati ◽  
Wang Zheng
Keyword(s):  
Water Mass ◽  
Mixed Layer Depth ◽  
Strong Mixing ◽  
High Salinity Water ◽  
The North ◽  
Vertical Diffusivity ◽  
Water Mass Analysis ◽  
Salinity Water ◽  
Vertical Turbulence ◽  
Weak Wind

Halmahera Sea is one of the locations in the eastern route of Indonesian Throughflow (ITF), where high salinity water is mainly transported by the ITF. The description of water mass in the Halmahera Sea from the perspective of water mass, and related mixing is important. It is not only useful for understanding water mass features, but it can also be used to determine the strength of the turbulent mixing, and so allow how it relates to the water transformation. Here, we report the water mass properties and estimation of mixing quantities in the Halmahera Sea from the CTD profiles based on recent onboard observations during the IOCAS cruise in November 2016. The water mass analysis was done by examining the characteristics of water types in the Temperature-Salinity (T-S) diagram. The mixing estimation uses the density profile derived from temperature and salinity profiles and the quantification of vertical turbulence observed by density overturn. Halmahera Sea is to be found as the location where the thermocline salinity changes abruptly, it is shown from the erosion of salinity maximum in the density of 22-26σθ decreased from the north to the south of the basin. It is associated with strong mixing with spots of higher vertical diffusivity in the thermocline and intermediate layer. In the upper layer, the mixed layer depth in the Halmahera Sea is relatively shallow with an average of about 16.95 m and it is associated with weak wind stress during this month.

scholarly journals Material transport in a convective surface mixed layer under weak wind forcing

2015 ◽  
Vol 96 ◽  
pp. 226-242 ◽  
Author(s):  
Jean A. Mensa ◽  
Tamay M. Özgökmen ◽  
Andrew C. Poje ◽  
Jörg Imberger
Keyword(s):  
Mixed Layer ◽  
Wind Forcing ◽  
Surface Mixed Layer ◽  
Material Transport ◽  
Weak Wind

A climatological diffusion model for ground level and elevated emissions in a weak-wind area

1985 ◽  
Vol 8 (3) ◽  
pp. 282-299 ◽  
Author(s):  
P. Melli ◽  
A. Spirito ◽  
M. Alabiso ◽  
P. Bacci ◽  
G. Carboni ◽  
...  
Keyword(s):  
Diffusion Model ◽  
Ground Level ◽  
Weak Wind

Tall building influence on city wind pattern

2018 ◽  
Vol 29 (10) ◽  
pp. 1850086
Author(s):  
M. S. Almeida ◽  
A. D. Araújo ◽  
M. P. Almeida
Keyword(s):  
Population Growth ◽  
Numerical Simulations ◽  
Turbulence Model ◽  
Natural Ventilation ◽  
Tall Buildings ◽  
Navier Stokes ◽  
Urban Centers ◽  
Wind Pattern ◽  
Rans Equations ◽  
Weak Wind

The population growth in big urban centers generates the necessity for tall buildings. This phenomenon happens also in tourist regions where it is necessary to host many people. However, locations with high buildings interfere with the flow of the wind and can affect the comfort and safety of pedestrians at street level. Tall buildings barrier reduces the natural ventilation in regions far from the beach. This work presents the results concerning the effects created by tall buildings on Mucuripe beach, Fortaleza, Brazil. We performed numerical simulations to verify the wind interference with buildings in an area of [Formula: see text][Formula: see text]m2, using the OpenFOAM toolbox, to solve the Reynolds Averaged Navier–Stokes (RANS) equations with the [Formula: see text]–[Formula: see text] turbulence model. The results showed how the obstacles alter the airflow. From them, one can identify the regions with reduced safety and pedestrian comfort, and also the weak wind zone created by the downstream of the constructions for the different wind directions that are locally observed.

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