Results 271 to 280 of about 2,951,677 (344)

Climatic response of annual tree-rings

SPIE Proceedings, 2014
Extensive literature devoted to investigations into the influence of environmental conditions on the plant respiration and respiration rate. It is generally accepted that the respired CO2 generated in a stem completely diffuses into the atmosphere. Results obtained from explorations into the CO2 content in disc tree rings by the method proposed in this
Boris G. Ageev, Aleksandr N. Gruzdev, Yurii N. Ponomarev, Valeria A. Sapozhnikova   +3 more
openaire   +1 more source

An Annual Ring Antenna for UWB Communications

IEEE Antennas and Wireless Propagation Letters, 2006
An ultrawideband (UWB) annual ring antenna is presented in this letter. The annual ring antenna has a return loss better than 10 dB from 2.8 to 12.3 GHz. It has an average gain of 2.93 dBi and has a maximum gain of 5 dBi at 7 GHz. The antenna radiation patterns are stable within its operation band.
Y.-j. Ren, K. Chang
openaire   +1 more source

Annual Bird Ringing Totals and Population Fluctuations

Oikos, 1978
Ringing of migrant birds has taken place at Ottenby, Oland, southeast Sweden since 1947. The effect of the winter weather in northwestern Europe on the wren Troglodytes troglodytes, of precipitation in the Sahel zone on the common whitethroat Sylvia communis and of the use of alkyl mercury compounds in Swedish agriculture on the yellowhammer Emberiza ...
Christian Hjort, Claes-Göran Lindholm, Claes-Goran Lindholm   +2 more
openaire   +1 more source

Planar magnetostatic wave resonator with annual-ring slot

IEEE 1991 Ultrasonics Symposium, 2002
A novel type of resonator using magnetostatic forward volume waves (MSFVWs) with an annual-ring slot is presented, where the annual-ring slot formed on an yttrium iron garnet (YIG) film by a photolithography technique plays a role in confining the energy of magnetostatic waves.
N. Guan, K. Yashiro, S. Ohkawa
openaire   +1 more source

A simple model for density of annual rings

Wood Science and Technology, 1995
A simple model for density distribution within an annual ring is proposed. The model originates from the concept that a tree has two growing modes ''early'' and ''late'' wood mode respectively and ...
K. Pernest�l, B. Jonsson, B. Larsson
openaire   +1 more source

Proof of concept to characterize historical heavy-metal concentrations in atmosphere in North Turkey: determining the variations of Ni, Co, and Mn concentrations in 180-year-old Corylus colurna L. (Turkish hazelnut) annual rings

Acta Physiologiae Plantarum, 2023
K. Key, Şemsettin Kulaç, I. Koc, Hakan Şevik   +3 more
semanticscholar   +1 more source

Do Annual Rings Really Reveal Cd, Ni, and Zn Pollution in the Air Related to Traffic Density? An Example of the Cedar Tree

Water, Air and Soil Pollution, 2023
Hatice Çobanoğlu, Hakan Şevik, Ismail Koc   +2 more
semanticscholar   +1 more source

Determining the 180-year Change of Cd, Fe, and Al Concentrations in the Air by Using Annual Rings of Corylus colurna L

Water, Air and Soil Pollution, 2022
K. Key, Şemsettin Kulaç, Ismail Koc, Hakan Şevik   +3 more
semanticscholar   +1 more source

Broadband Dual-frequency CPW-fed Annual-ring Antenna

2006 IEEE Antennas and Propagation Society International Symposium, 2006
A new broadband annual-ring antenna fed by CPW (coplanar waveguide) is developed for mobile communication applications. The antenna adopts a single-layer double-side configuration. Two annual rings are used to activate the dual operating frequencies.
null Yu-Jiun Ren, null Kai Chang
openaire   +1 more source

The usability of Cupressus arizonica annual rings in monitoring the changes in heavy metal concentration in air

Environmental science and pollution research international, 2021
A. Cesur, İ. Zeren Çetin, Adel Easa Saad Abo Aisha, O. B. M. Alrabiti, Akram Mohamed Omar Aljama, Asma Asghar Jawed, M. Çetin, Hakan Şevik, H. Ozel   +8 more
semanticscholar   +1 more source