نتایج جستجو برای: clearing of trees

تعداد نتایج: 21171959  

2016
Astrid Ziemann Arthur Schady Dietrich Heimann

The influence of trees on sound propagation is currently discussed to reduce the sound exposure near transport infrastructure or industrial areas. This influence is direct due to reflection and scattering at the trees themselves as well as indirect through meteorological and ground effects modified by the trees. Previous investigations provide a mixed picture of sound attenuation within foreste...

Journal: :جنگل و فرآورده های چوب 0
آزاده دلجویی کارشناس ارشد مهندسی جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران احسان عبدی دانشیار گروه جنگلداری و اقتصاد جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران باریس مجنونیان استاد گروه جنگلداری و اقتصاد جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران

forest roads are directions in natural habitats that used to transport wood products, secondary forest products and recreation. constructing forest roads causes trees clearing with specified width thus lead to direct or indirect changes in forest ecosystems and forest environment. this study aims to assess the changes of diversity and richness indices in main and secondary forest roads in a par...

2006
Lindsay N Trapnell L R Malcolm C R Beverly

Abstract. The clearing of trees and native vegetation over the past 160 years has caused deep drainage to groundwater in the Broken Plains area. Predictions are that continuing recharge will bring the water-table to within 2 metres of the surface over the next 30 years. This will lead to water-logging and dryland salinity. A solution is to introduce deep-rooted perennial species such as lucerne...

Journal: :Cadernos de saude publica 1999
U Teodoro J B Kühl D R Santos E S Santos

Tree felling around a chicken coop and periodic insecticide spraying at the Palmital farm in the county of Terra Boa in southern Brazil impacted the ecology of sand fly species. The most prevalent species (51.6%) before clearing the trees and insecticide spraying was Lutzomyia migonei (França, 1920), and it is now Lutzomyia (Nyssomyia) whitmani (Antunes & Coutinho, 1939) (89.8%). There was a hi...

نجفی , مجتبی, احسان , مهدی , اخوین , علی , فتوحی فیروزآباد, محمود ,

A method for concurrent clearing of energy and reserve market is presented in this paper. The proposed method considers two important objectives in an optimization problem; the first one is including the stochastic nature of power generation variations by applying a probabilistic clearing model and Monte-Carlo simulation; the second one is assignment of energy and reserve capacities to generati...

Aslani Fatemeh Sari Bahraminia Sahar Brojeni Nahid Hemmatian Saki Nasrin

A 52-year-old woman sought medical attention because of several annular erythematous lesions with central clearing on her body since seven months ago. No pruritus or burning sensations were noted. Her medical and family history was unremarkable. Her Fitzpatrick skin photo-type was II. On dermatological physical examination, there were several annular erythematous plaques with raised borders and...

خرم نیا , رضا , رئوفت , مهدی ,

In restructured power systems, generation companies should offer a power - price curve to the market operator to participate the auction. The proposed bidding curve has a considerable impact on the unit profit, especially in pay as bid markets. The optimal bidding curve depends on the final market clearing price which is uncertain in the stage of bidding. This paper proposes a novel approach f...

Journal: :iranian endodontic journal 0
maryam javidi department of endodontics, dental school, mashad university of medical sciences, mashad, iran. [email protected] mehdi vatanpour department of endodontics, dental school, mashad university of medical sciences, mashad, iran shiva shirazian department of oral medicine, dental school, mashad university of medical sciences, mashad, iran

introduction: the aim of this study was to compare a clearing technique with conventional radiography in studying certain features of the root canal system in single root premolars. a secondary aim was to assess inter examiner agreement for these features using radiographs. materials and methods: fifty-eight recently extracted single rooted premolars were included in this study. two standard pe...

Supervisory control and data acquisition (SCADA) system monitors and controls industrial processes in critical infrastructures (CIs) and plays the vital role in maintaining the reliability of CIs such as power, oil, and gas system. In fact, SCADA system refers to the set of control process, which measures and monitors sensors in remote substations from a control center. These sensors usually ha...

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