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Articles 18391 - 18420 of 59552

Full-Text Articles in Earth Sciences

Patterns Of Development And Nitrogen Reserves Mobilization During Regrowth Of Defoliated Clover, F. Le Dily, E. Goulas, P. Lainé, E. Le Deunff Aug 2021

Patterns Of Development And Nitrogen Reserves Mobilization During Regrowth Of Defoliated Clover, F. Le Dily, E. Goulas, P. Lainé, E. Le Deunff

IGC Proceedings (1977-2023)

Contribution of nitrogen reserves to regrowth following defoliation was studied in white clover plants (Trifolium repens) according to the morphological pattern of differentiation of the aerial parts during the same period. Low temperature and short day lengths were used as a pre-treatment in order to increase branching and enhance new sites of leaf production during a further 25 d period of regrowth. Pre-treated plants exhibited a large reduction in leaf area largely counterbalanced with a high increase in leaf pool size during the first 10 d of regrowth. The mobilization of nitrogen reserves during regrowth of defoliated clover …


Resistance To Drought In Shore Elurope (Aeluropus Litoralis) And Weeping Alkaligrass (Puccinellia Distans), Mohammad Jafari, A. G. Firouzabadi Aug 2021

Resistance To Drought In Shore Elurope (Aeluropus Litoralis) And Weeping Alkaligrass (Puccinellia Distans), Mohammad Jafari, A. G. Firouzabadi

IGC Proceedings (1977-2023)

Two rangeland grass species, Shore Elurope (Aeluropus litoralis) and Weeping Alkaligrass (Puccinellia distans) were studied. The research was done under a split plot experiment and completely randomized design. Plants were grown under two irrigation treatments (seven and fourteen day periods of irrigation treatments). Morphological response included determination of wilting percentage, leaf water potential, production of yield, root dry weight, weight ratio of root/stem and finally total dry weight of species. Anatomical studies included leaf descriptive structure such as comparison of stomata and their density in area unit, study of vascular structure, mesophyl tissues and epiderm. Results …


Mgrre_Pureoilscouttickets_Kinster_1_21127005020000, Mgrre Aug 2021

Mgrre_Pureoilscouttickets_Kinster_1_21127005020000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.


Investigations Of Trace Element Titanium In Silica Minerals, Zachary Robert Osborne Aug 2021

Investigations Of Trace Element Titanium In Silica Minerals, Zachary Robert Osborne

Dissertations - ALL

Quartz is a common mineral in many igneous, metamorphic, and sedimentary rocks because it is stable over a wide range of pressure (P) and temperature (T) conditions; therefore, quartz is an excellent mineral to target for thermobarometric uses. Thermobarometry is the quantitative determination of the pressure (baro-) and temperature (thermo-) conditions at which a natural rock sample reached chemical equilibrium. This dissertation contains three chapters describing mineral synthesis experiments that quantify and define the trace-element solubility behavior of titanium (Ti) in the silica minerals quartz and coesite, to advance the understanding and application of trace-element thermobarometry.Chapter 1 details the experiments …


Evaluating The Controls Of Neogene Exhumation In The Tropical Northern Andes (Colombia), Nicolas Perez Consuegra Aug 2021

Evaluating The Controls Of Neogene Exhumation In The Tropical Northern Andes (Colombia), Nicolas Perez Consuegra

Dissertations - ALL

Understanding how tectonic and climatic forces influence erosion and shape mountains is important to understand the evolution of the landscapes through earth's history. This dissertation aims to determine how do tectonic processes and climate variability interact to shape Earth's tropical mountains. In chapter 1, I studied the Eastern Cordillera of the Northern Andes, a mountain range located in Colombia in the tropics of South America. To obtain exhumation rates, I used thermochronology, which is a method that records—over timescales of millions of years—the rate at which rocks located at great depths within the Earth cool as they are transported to …


Analysis Of Rock Varnish From The Mojave Desert By Handheld Laser-Induced Breakdown Spectroscopy, Russell S. Harmon, Daria Khashchevskaya, Michelle Morency, Lewis A. Owen, Morgan Jennings, Jeffrey R. Knott, Jason M. Dortch Aug 2021

Analysis Of Rock Varnish From The Mojave Desert By Handheld Laser-Induced Breakdown Spectroscopy, Russell S. Harmon, Daria Khashchevskaya, Michelle Morency, Lewis A. Owen, Morgan Jennings, Jeffrey R. Knott, Jason M. Dortch

Faculty, Staff, and Affiliated Publications--KGS

Laser-induced breakdown spectroscopy (LIBS) is a form of optical emission spectroscopy that can be used for the rapid analysis of geological materials in the field under ambient environmental conditions. We describe here the innovative use of handheld LIBS for the in situ analysis of rock varnish. This thinly laminated and compositionally complex veneer forms slowly over time on rock surfaces in dryland regions and is particularly abundant across the Mojave Desert climatic region of east-central California (USA). Following the depth profiling examination of a varnished clast from colluvial gravel in Death Valley in the laboratory, our in situ analysis of …


Mgrre_Pureoilscouttickets_Snow, Bert_1_21127002200000, Mgrre Aug 2021

Mgrre_Pureoilscouttickets_Snow, Bert_1_21127002200000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.


Microbial Activity Responses To Water Stress In Agricultural Soils From Simple And Complex Crop Rotations, Jorg Schnecker, D. Boone Meeden, Francisco Calderon, Michel Cavigelli, R. Michael Lehman, Lisa K. Tiemann, A. Stuart Grandy Aug 2021

Microbial Activity Responses To Water Stress In Agricultural Soils From Simple And Complex Crop Rotations, Jorg Schnecker, D. Boone Meeden, Francisco Calderon, Michel Cavigelli, R. Michael Lehman, Lisa K. Tiemann, A. Stuart Grandy

Faculty Publications

Increasing climatic pressures such as drought and flooding challenge agricultural systems and their management globally. How agricultural soils respond to soil water extremes will influence biogeochemical cycles of carbon and nitrogen in these systems. We investigated the response of soils from long-term agricultural field sites under varying crop rotational complexity to either drought or flooding stress. Focusing on these contrasting stressors separately, we investigated soil heterotrophic respiration during single and repeated stress cycles in soils from four different sites along a precipitation gradient (Colorado, MAP 421 mm; South Dakota, MAP 580 mm; Michigan, MAP 893 mm; Maryland, MAP 1192 mm); …


Allelopathic Influence Of Eragrostis Curvula Water Extract On Seed Germination And Seedling Growth Of Two Other Species, R. W. Coelho, R. E. Schmidt Aug 2021

Allelopathic Influence Of Eragrostis Curvula Water Extract On Seed Germination And Seedling Growth Of Two Other Species, R. W. Coelho, R. E. Schmidt

IGC Proceedings (1977-2023)

Weeping lovegrass (Eragrostis curvula Schrad. Nees) is a very agressive tropical species and does not grow well with other species. This study was set up to investigate the allelopathic effect of various extract concentrations of weeping lovegrass on seed germination of white clover (Trifolium repens L.) and bentgrass (Agrostis stolonifera L.) and the seedling development of white clover. Labotatory and growth chamber studies were conducted. Extract concentrations of 13.6, 27.2, 40.8, 54.4, and 62.0 g/100mL of water were studied. Treatments were arranged in a completely ramdomized design with three replications. The allelopathic effect of weeping lovegrass was …


Effect Of Aging In Tillers Of Panicum Maximum On Leaf Elongation Rate, D. D. Carvalho, C. Matthew, J. Hodgson Aug 2021

Effect Of Aging In Tillers Of Panicum Maximum On Leaf Elongation Rate, D. D. Carvalho, C. Matthew, J. Hodgson

IGC Proceedings (1977-2023)

Two cultivars of Guinea grass (P. maximum, Jacq.), Mombaça and Tanzânia, were cultivated in five litre pots, as single plants, in a green house. Plants were subjected to three defoliation levels (100, 200 and 400 mm height) for five successive monthly harvests. The experimental design was a 3x2 randomised block with five replicates. Three types of tiller (main, primary and secondary) were selected, at random, on each plant and leaf elongation rate (LER) above cutting height was measured, weekly, between harvests. There were significant differences (P < 0.05) in LER between tiller types in cv. Mombaça in all periods, but only in period two in cv. Tanzânia. In the last period tillers were classified, at random, as old (over four months age) mature (between two and four months) and young (between one and two months). Old tillers had a lower (P < 0.05) LER than the other two categories in both cultivars and lower (P < 0.05) SLA (specific leaf area) in Mombaça.


Dormant Bud Development In Phalaris Aquatica L., Brendan R. Cullen, P. E. Quigley, D. F. Chapman Aug 2021

Dormant Bud Development In Phalaris Aquatica L., Brendan R. Cullen, P. E. Quigley, D. F. Chapman

IGC Proceedings (1977-2023)

The formation of dormant buds is critical to the summer survival of phalaris (Phalaris aquatica L.) in pastures. Dormant buds are formed on the base of reproductive tillers as they develop in spring. This project aimed to determine the seasonal pattern of dormant bud development and the influence of grazing management on bud dynamics. Approximately three buds per reproductive tiller were formed in the spring and early summer period. These buds responded to summer rainfall, with one third of buds becoming active following a 15-mm rainfall event in mid summer. In the following growing season, on average, 1.5 buds …


Tillering Dynamics Of Panicum Maximum Jacq. Cv. Tanzania-1 After Grazing, Rodrigo A. Barbosa, Domicio Nascimento Jr., Valéria P. B. Euclides, A. J. Regazzi, D. M. Fonseca Aug 2021

Tillering Dynamics Of Panicum Maximum Jacq. Cv. Tanzania-1 After Grazing, Rodrigo A. Barbosa, Domicio Nascimento Jr., Valéria P. B. Euclides, A. J. Regazzi, D. M. Fonseca

IGC Proceedings (1977-2023)

Tillering dynamics and tiller dry matter weight from Tanzania grass (Panicum maximum cv. Tanzania-1) were evaluated in two post-grazing stubbles (High Post-grazing Stubble – HPS-3.6 t of DM/ha and Low Post-grazing Stubble – LPS-2.3 t of DM/ha). There was no difference between post-grazing stubbles for decapitated axillary and basal remainder and new axillary tillers. The LPS presented greater number of new basal tillers. The rate of appearance of new basal and axillary tillers decreased with time after grazing. There were differences between the treatments on tiller dry matter weight, and greater values were found in the high post-graze stubble.


Flowering Distribution Pattern In White Clover Cultivars, B. S. Rosso, E. M. Pagano, P. Rimieri Aug 2021

Flowering Distribution Pattern In White Clover Cultivars, B. S. Rosso, E. M. Pagano, P. Rimieri

IGC Proceedings (1977-2023)

A trial was carried out at Pergamino Agricultural Experimental Station to examine the distribution pattern and the profuseness of inflorescence production of white clover (Trifolium repens L.). The treatments were 16 cultivars (Churrinche, El Lucero MAG, Bayucuá, Estanzuela Zapicán, Lucero Plus Inta, Haifa, California, Ladino Gigante Lodigiano, Dubrava, Susi, Merwi, Blanca, Sonja, Espanso, Nora, S 184) of different origins and leaf size. The experimental design was a lattice with four replications. Southamerican cultivars showed a similar distribution pattern and had the highest inflorescence production. They also flowered earlier than foreign cultivars, except Haifa. Some of the cultivars evaluated did …


Breeding Italian Annual Ryegrass For Tolerance To Pythium Ultimum, L. R. Nelson, I. J. Pemberton, G. R. Smith Aug 2021

Breeding Italian Annual Ryegrass For Tolerance To Pythium Ultimum, L. R. Nelson, I. J. Pemberton, G. R. Smith

IGC Proceedings (1977-2023)

This study was conducted in an attempt to improve tolerance of annual ryegrass to Pythium ultimum Trow. Improved tolerance of ryegrass as measured in laboratory experiments was confirmed in greenhouse studies. This tolerance was defined as improved emergence and increased root length of seedlings in the presence of P. ultimum, using rolled germination paper in the laboratory, and sand in the greenhouse. Further experimentation will be required to determine usefulness of this selected trait under field conditions.


Suitable Seed Harvesting Time For Six Grass Species, Hossein Arzani, A. Fakhireh Aug 2021

Suitable Seed Harvesting Time For Six Grass Species, Hossein Arzani, A. Fakhireh

IGC Proceedings (1977-2023)

Determination of the best period of seed harvesting was considered. Six grass species were selected. The research was conducted in three stations of Alborz, Sirachal and Homand Absard. According to maturing stages, seed collection for measuring seed water content (moisture content), weight of 1000 seeds and germination percentage has been done. The result showed that there were significant differences between harvesting time on seed germination for all species in all regions. Moisture content, germination rate, weight of 1000 seeds and seed shedding were important characteristics for determination of suitable seed harvesting time.


Effect Of Nitrogen Fertilizer On Reproductive Tiller Development In Perennial Ryegrass, I. Bahmani, E. R. Thom, C. Matthew, G. Lemaire Aug 2021

Effect Of Nitrogen Fertilizer On Reproductive Tiller Development In Perennial Ryegrass, I. Bahmani, E. R. Thom, C. Matthew, G. Lemaire

IGC Proceedings (1977-2023)

The objective of this study was to compare reproductive tiller development in two ryegrass (Lolium perenne L.) cultivars, when fertilized with nitrogen. Plots of the cultivars ‘Grasslands Ruanui’ and ‘Ellett’ ryegrass were sown in April 1996. Half of each plot received nitrogen fertilizer (30 kg N/ha) after each grazing by dairy cows from September 1996 to May 1997 and from October 1997 to April 1998. Ryegrass tiller dynamics was monitored from September 1996 to March 1998. The proportion of reproductive tillers in the total tiller population was higher, on average, over the first flowering period (October 1996 to January …


Mgrre_Pureoilscouttickets_Shuler - Beem Aka G. A. Beam_1_21127001820000, Mgrre Aug 2021

Mgrre_Pureoilscouttickets_Shuler - Beem Aka G. A. Beam_1_21127001820000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.


Experimental Study On Advanced Real Time Detection System Of Seismic-While-Excavating, Wang Ji, Qin Si, Wu Hai, Zhang Qingqing, Yu Junhui, Su Xiaoyun Aug 2021

Experimental Study On Advanced Real Time Detection System Of Seismic-While-Excavating, Wang Ji, Qin Si, Wu Hai, Zhang Qingqing, Yu Junhui, Su Xiaoyun

Coal Geology & Exploration

Experimental study on advanced real time detection system of seismic-while-excavating


Three-Component Seismic Data Acquisition System Of Coal Mine Based On Mems And Lwip, Wang Huaixiu, Qiu Shuai, Zhu Guowei, Chen Bo Aug 2021

Three-Component Seismic Data Acquisition System Of Coal Mine Based On Mems And Lwip, Wang Huaixiu, Qiu Shuai, Zhu Guowei, Chen Bo

Coal Geology & Exploration

Three-component seismic data acquisition system of coal mine based on MEMS and LwIP


Depth Correction Technique Of Electrical Marker Based On Electrical Field Component Of Csamt, Liu Zuiliang, Zhang Fenxuan, Zhang Jifeng, Zhou Guangyu, Zhao Hui, Zhang Xin Aug 2021

Depth Correction Technique Of Electrical Marker Based On Electrical Field Component Of Csamt, Liu Zuiliang, Zhang Fenxuan, Zhang Jifeng, Zhou Guangyu, Zhao Hui, Zhang Xin

Coal Geology & Exploration

Depth correction technique of electrical marker based on electrical field component of CSAMT


Evaluation On The Resolution Ability Of Underground Transient Electromagnetic Instrument To Disaster-Causing Water Bodies, Zhao Zhongnan, Xu Yangcheng, Wu Yanqing, Tan Qingqing, Kang Yueming, Wang Yao Aug 2021

Evaluation On The Resolution Ability Of Underground Transient Electromagnetic Instrument To Disaster-Causing Water Bodies, Zhao Zhongnan, Xu Yangcheng, Wu Yanqing, Tan Qingqing, Kang Yueming, Wang Yao

Coal Geology & Exploration

Evaluation on the resolution ability of underground transient electromagnetic instrument to disaster-causing water bodies


Technology Of Across-Goaf Drainage Of Coalbed Methane From A Lower Coal Seam Group And Its Primary Application: Taking Sihe Mine Field As An Example, Li Junjun, Li Guofu, Hao Haijin, Hao Chunsheng, Wang Zheng Aug 2021

Technology Of Across-Goaf Drainage Of Coalbed Methane From A Lower Coal Seam Group And Its Primary Application: Taking Sihe Mine Field As An Example, Li Junjun, Li Guofu, Hao Haijin, Hao Chunsheng, Wang Zheng

Coal Geology & Exploration

Technology of across-goaf drainage of coalbed methane from a lower coal seam group and its primary application: Taking Sihe mine field as an example


Sequence Stratigraphy And Coal Accumulation Of Barrier Coastal System Under Epicontinental-Sea Environment: A Case Study Of The Late Paleozoic Taiyuan Formation In Bohai Bay Area, Chang Jia, Chen Shiyue, Wang Qiong, Pu Xiugang, Yang Huaiyu Aug 2021

Sequence Stratigraphy And Coal Accumulation Of Barrier Coastal System Under Epicontinental-Sea Environment: A Case Study Of The Late Paleozoic Taiyuan Formation In Bohai Bay Area, Chang Jia, Chen Shiyue, Wang Qiong, Pu Xiugang, Yang Huaiyu

Coal Geology & Exploration

Sequence stratigraphy and coal accumulation of barrier coastal system under epicontinental-sea environment: A case study of the Late Paleozoic Taiyuan Formation in Bohai Bay Area


Distribution Characteristics Of Heavy Minerals In The Sandstone Of Zhiluo Formation Of Northern Ordos Basin And Its Implication, Zhang Yuanyuan, Zhang Pengfei, Nie Fengjun, Yan Pengbing, Zhang Zhibo, Yan Zhaobin, Zhang Xin Aug 2021

Distribution Characteristics Of Heavy Minerals In The Sandstone Of Zhiluo Formation Of Northern Ordos Basin And Its Implication, Zhang Yuanyuan, Zhang Pengfei, Nie Fengjun, Yan Pengbing, Zhang Zhibo, Yan Zhaobin, Zhang Xin

Coal Geology & Exploration

Distribution characteristics of heavy minerals in the sandstone of Zhiluo Formation of northern Ordos Basin and its implication


Effects Of Different Combined Pretreatments On Biogenic Methane Production By Anaerobic Digestion Of Lignite, Zhang Huaiwen, Yao Yiqing, Xie Changwen Aug 2021

Effects Of Different Combined Pretreatments On Biogenic Methane Production By Anaerobic Digestion Of Lignite, Zhang Huaiwen, Yao Yiqing, Xie Changwen

Coal Geology & Exploration

Effects of different combined pretreatments on biogenic methane production by anaerobic digestion of lignite


Development And Application Of Borehole Sealing Technology For Water-Sand Inrush From Ordovician Limestone Aquifer In Coal Mine, Li Xiaolong Aug 2021

Development And Application Of Borehole Sealing Technology For Water-Sand Inrush From Ordovician Limestone Aquifer In Coal Mine, Li Xiaolong

Coal Geology & Exploration

Development and application of borehole sealing technology for water-sand inrush from Ordovician limestone aquifer in coal mine


Exploration Method Of Underground Geological Anomaly And Its Application Based On Directional Drilling, Fang Jun Aug 2021

Exploration Method Of Underground Geological Anomaly And Its Application Based On Directional Drilling, Fang Jun

Coal Geology & Exploration

Exploration method of underground geological anomaly and its application based on directional drilling


Development Characteristics Of Coal Microfracture And Coal Petrology Control Under Cyclic High Voltage Electrical Pulse, Li Hengle, Qin Yong, Zhou Xiaoting, Zhang Yongmin, Chen Yilin Aug 2021

Development Characteristics Of Coal Microfracture And Coal Petrology Control Under Cyclic High Voltage Electrical Pulse, Li Hengle, Qin Yong, Zhou Xiaoting, Zhang Yongmin, Chen Yilin

Coal Geology & Exploration

Development characteristics of coal microfracture and coal petrology control under cyclic high voltage electrical pulse


Temporal And Spatial Evolution Of Surface Thermal Environment In Huainan Mining Area In The Last Decade, Fang Liangcheng, Chen Yongchun, An Shikai, Xu Yanfei, Zhao Yuejiao, Wang Ning, Li Zhihui, Zhao Ping Aug 2021

Temporal And Spatial Evolution Of Surface Thermal Environment In Huainan Mining Area In The Last Decade, Fang Liangcheng, Chen Yongchun, An Shikai, Xu Yanfei, Zhao Yuejiao, Wang Ning, Li Zhihui, Zhao Ping

Coal Geology & Exploration

Temporal and spatial evolution of surface thermal environment in Huainan Mining Area in the last decade


Numerical Study Of Mabian Landslide Kinematics And Impact Intensity, Chen Xing, Zhao Zhou, Wei Jiangbo, Xu Chong Aug 2021

Numerical Study Of Mabian Landslide Kinematics And Impact Intensity, Chen Xing, Zhao Zhou, Wei Jiangbo, Xu Chong

Coal Geology & Exploration

Numerical study of Mabian landslide kinematics and impact intensity