Particle Scavenging Properties of Rain Clarified by a Complementary Study with Bulk and Semi-bulk Samples

2018 ◽  
Vol 34 (1) ◽  
pp. 177-186 ◽  
Author(s):  
Chang-Jin Ma ◽  
Gong-Unn Kang
2010 ◽  
Vol 10 (12) ◽  
pp. 5685-5705 ◽  
Author(s):  
X. Wang ◽  
L. Zhang ◽  
M. D. Moran

Abstract. Current theoretical and empirical size-resolved parameterizations of the scavenging coefficient (Λ), a parameter commonly used in aerosol transport models to describe below-cloud particle scavenging by rain, have been reviewed in detail and compared with available field and laboratory measurements. Use of different formulations for raindrop-particle collection efficiency can cause uncertainties in size-resolved Λ values of one to two orders of magnitude for particles in the 0.01–3 μm diameter range. Use of different formulations of raindrop number size distribution can cause Λ values to vary by a factor of 3 to 5 for all particle sizes. The uncertainty in Λ caused by the use of different droplet terminal velocity formulations is generally small than a factor of 2. The combined uncertainty due to the use of different formulations of raindrop-particle collection efficiency, raindrop size spectrum, and raindrop terminal velocity in the current theoretical framework is not sufficient to explain the one to two order of magnitude under-prediction of Λ for the theoretical calculations relative to the majority of field measurements. These large discrepancies are likely caused by additional known physical processes (i.e, turbulent transport and mixing, cloud and aerosol microphysics) that influence field data but that are not considered in current theoretical Λ parameterizations. The predicted size-resolved particle concentrations using different theoretical Λ parameterization can differ by up to a factor of 2 for particles smaller than 0.01 μm and by a factor of >10 for particles larger than 3 μm after 2–5 mm of rain. The predicted bulk mass and number concentrations (integrated over the particle size distribution) can differ by a factor of 2 between theoretical and empirical Λ parameterizations after 2–5 mm of moderate intensity rainfall.


2008 ◽  
Vol 22 (23) ◽  
pp. 3816-3822 ◽  
Author(s):  
Yuko T. Iwata ◽  
Kenji Kuwayama ◽  
Kenji Tsujikawa ◽  
Hajime Miyaguchi ◽  
Tatsuyuki Kanamori ◽  
...  

Author(s):  
AHMAD FIRDAUSE MD FADZIL ◽  
MOHD RAFI YAACOB ◽  
FAUZILAH SALLEH ◽  
AHMAD SHUKRI YAZID ◽  
ZAINUDIN AWANG

A number of intensive studies on entrepreneurs which consider entrepreneurship as one of the mostimportant elements in business have been conducted within the past few years. An entrepreneur isresponsible for every aspect of a new venture’s creation considering that they are usually the lead personin every business decision. To date, researchers have tended to ignore the issues related to the qualitiesof entrepreneurs in the creation of new e-commerce ventures. While entrepreneurial competencies havebecome extremely important recently, as a complementary study, the personality traits of the entrepreneurcould also be studied. Much uncertainty still exists; hence, this study set out to determine the role ofpersonality and entrepreneurial competencies in the creation of new e-commerce ventures in Malaysia.This research uses a case studies approach in which data was collected by interviewing twelve e-commerceentrepreneurs from May 2013 until December 2014. The fi ndings have identifi ed that seven personalitytraits are most prevalent; namely, creativity, risk taking, inspiration, need for autonomy and freedom,tolerance of ambiguity, a hardworking and persistent attitude, and optimism, all of which vigorously havecontributed to new e-commerce venture creation in Malaysia. In the case of entrepreneurial competencies,it was deemed crucial for entrepreneurs to be equipped with both computer and communication skills tofacilitate the creation of new ventures. Therefore, it is best for the government to promote entrepreneurialactivity by highlighting the elements of entrepreneurs in terms of personality traits and entrepreneurialcompetency aspects. Finally, through a better understanding of our entrepreneurs, we will amplify theemergence of new ventures to strengthen the economic progress of the country.   Kajian lepas secara intensif telah melihat keusahawanan adalah sesuatu elemen yang penting dalamperniagaan sejak kebelakangan ini. Usahawan adalah bertanggungjawab terhadap segala aspekkeputusan dalam perniagaan yang dijalankan. Para penyelidik kini telah cenderung mengabaikan isuisu yang berkaitan dengan kualiti dimiliki usahawan terutamanya dalam konteks peniagaan e-dagangyang diketahui telah memberikan sumbangan besar terhadap nilai ekonomi kepada negara. Walaupunelemen kompetensi dimiliki usahawan menjadi kajian yang penting, sebagai pelengkap, personalitiusahawan turut menjadi keutamaan untuk dikaji oleh para penyelidik. Dengan ketidakpastian yangmasih wujud; objektif kajian ini adalah melihat peranan personaliti dan kompetensi usahawan terhadapproses penciptaan perniagaan baharu e-dagang di Malaysia. Kajian ini menggunakan pendekatan secarakajian kes iaitu seramai dua belas usahawan e-dagang telah ditemubual bermula Mei 2013 sehinggaDisember 2014. Penemuan kajian ini telah mengenal pasti terdapat tujuh ciri-ciri personaliti; iaitu kreativiti,mengambil risiko, inspirasi, keperluan autonomi dan kebebasan, toleransi terhadap kekaburan, sikapyang rajin dan cekal, dan optimistik adalah menyumbang kepada proses penciptaan perniagaan baharu e-dagang di Malaysia. Dalam konteks kompetensi, ia dianggap penting bagi usahawan untuk dilengkapidengan kemahiran komputer dan kemahiran berkomunikasi bagi memudahkan mereka semasa prosespenciptaan perniagaan baharu tersebut. Oleh itu, adalah terbaik bagi kerajaan mempromosikan aktivitikeusahawanan dengan menonjolkan espek personaliti dan kompetensi diri perlu dimiliki oleh usahawan.Akhirnya, penerapan pemahaman yang lebih baik berkenaan keusahawanan akan mengukuhkan nilaiekonomi di sesebuah negara melalui peningkatan KDNK, penciptaan peluang pekerjaan, dan nilai tambahmelalui kemunculan perniagaan baharu. 


2006 ◽  
Vol 45 (20) ◽  
pp. 4898 ◽  
Author(s):  
Didier Bruneau ◽  
Fabien Gibert ◽  
Pierre H. Flamant ◽  
Jacques Pelon

Cureus ◽  
2016 ◽  
Author(s):  
Jose Martinez-Mas ◽  
Alberto Miranda-Paanakker ◽  
Paloma Gomez-Leal ◽  
Patricia Navarro-Sanchez ◽  
Andres Bueno-Crespo ◽  
...  

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