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Articles 1471 - 1500 of 302419

Full-Text Articles in Physical Sciences and Mathematics

Exploring The Pyrolysis Of Tar-Rich Coals Under The Catalysis Of Cerium-Modified Magnetic Core-Shell Hzsm-5, Zhou Anning, Zhang Zhi, Chen Yongan, Zhang Huaiqing, Bai Zhuangwei, Shi Zhiwei, He Xinfu Jul 2024

Exploring The Pyrolysis Of Tar-Rich Coals Under The Catalysis Of Cerium-Modified Magnetic Core-Shell Hzsm-5, Zhou Anning, Zhang Zhi, Chen Yongan, Zhang Huaiqing, Bai Zhuangwei, Shi Zhiwei, He Xinfu

Coal Geology & Exploration

Objective Tar-rich coals are valuable resources integrating coal, tar, and gas properties. Catalytic pyrolysis serves as a significant approach for achieving green and low-carbon development of tar-rich coals. However, the research and development of efficient and recyclable catalysts for the pyrolysis of tar-rich coals remains highly challenging. Methods With HZSM-5@SiO2@MgFe2O4 (HSMF) as the raw material, this study prepared HZSM-5@SiO2@MgFe2O4 (mHSMF) with a hierarchical porous structure using the hydrothermal method and alkali modification, followed by the preparation of cerium-modified mHSMF (5-CeO2/mHSMF) using the precipitation method. Employing a fixed-bed reactor, …


Advances In Research On Hydrogenation Saturation Of Polycyclic Aromatic Hydrocarbons In Coal Tar, He Xinfu, Gao Fan, Wu Hongju, Zhang Xiaoqin, Ma Tao, Shi Zhiwei, Zhou Anning, Zhang Yating Jul 2024

Advances In Research On Hydrogenation Saturation Of Polycyclic Aromatic Hydrocarbons In Coal Tar, He Xinfu, Gao Fan, Wu Hongju, Zhang Xiaoqin, Ma Tao, Shi Zhiwei, Zhou Anning, Zhang Yating

Coal Geology & Exploration

Significance Polycyclic aromatic hydrocarbons (PAHs), a predominant component in coal tar, can be used to produce jet fuels with high energy density and thermal stability through hydrogenation saturation. Based on the characteristics of the PAH hydrogenation process, this study proposed that primary challenges in PAH hydrogenation saturation include the resonance energy of PAHs themselves, the spatial site resistance of hydrogenation intermediates, and the competitive adsorption of feedstocks and intermediates on active sites in the catalysts. Progress Based on the review of research progress in catalysts for PAH hydrogenation saturation in recent years, this study analyzed the substantial factor influencing the …


Simulation Of The Pyrolysis Process Of Tar-Rich Coals In An H2O Atmosphere Based On The Reactive Force Field Molecular Dynamics, Huang Zibo, Liu Qianru, Liu Hong, Zhou Wenjing, Wei Jinjia Jul 2024

Simulation Of The Pyrolysis Process Of Tar-Rich Coals In An H2O Atmosphere Based On The Reactive Force Field Molecular Dynamics, Huang Zibo, Liu Qianru, Liu Hong, Zhou Wenjing, Wei Jinjia

Coal Geology & Exploration

Objective Tar-rich coal resources, abundant in China, can be converted into energy products (e.g., chemicals and gas/liquid fuels) through pyrolysis, thus alleviating the country’s dependence on oil and gas imports. A thorough understanding of the product evolution and reaction mechanisms of the pyrolysis of tar-rich coals is crucial to research into the clean and efficient conversion processes of coals. Methods Based on the reactive force field molecular dynamics (ReaxFF MD), this study simulated the pyrolysis process of tar-rich coals (long-flame coals) and explored the impacts of the H2O atmosphere on the distribution of pyrolytic products, along with the …


Performance Of Carbon Foams Based On Heavy Tar Produced By Tar-Rich Coal Pyrolysis, Zhang Lei, Liu Chunjiang, Song Ruikang, Wang Qi, Chen Ya, Huang Pengcheng Jul 2024

Performance Of Carbon Foams Based On Heavy Tar Produced By Tar-Rich Coal Pyrolysis, Zhang Lei, Liu Chunjiang, Song Ruikang, Wang Qi, Chen Ya, Huang Pengcheng

Coal Geology & Exploration

Objective Preparing graphitized foam materials using heavy tar produced by the pyrolysis of tar-rich coals plays a significant role in the high-value utilization of tar-rich coal resources. Methods This study aims to prepare high-performance carbon foam materials by investigating the relationships between various reaction conditions and carbon foam performance. First, using mesophase asphalt prepared with heavy tar as the precursor, carbon foams were developed via the high-temperature self-foaming method. Then, the effects of different reaction temperatures, heating rates, and reaction pressures on the performance of coal tar-based carbon foams were examined. Finally, quadratic multinomial regression equations were established using Box-Behnken …


Survey Of Space Professionals’ Perception Of Satellite Cybersecurity From 2012 To 2022: Decision-Makers’ Thoughts On Satellite Cybersecurity Evolving, Rachel C. Jones Jul 2024

Survey Of Space Professionals’ Perception Of Satellite Cybersecurity From 2012 To 2022: Decision-Makers’ Thoughts On Satellite Cybersecurity Evolving, Rachel C. Jones

Aerospace Sciences Student Publications

Cyberattacks on space assets are often portrayed in vague terms of doubt and mystery. Several claims depict satellites being compromised or attacked, but little corroboration has been published or made publicly available. As the commercial space industry grows, increased concern with space cybersecurity will prompt commercial satellite decision-makers to analyze the often-undefined risk of cyberattacks against satellites. This article identifies and characterizes the nature of cybersecurity risks to space assets and postulates why space professionals might not prioritize cybersecurity. Additional information was captured from a decadal survey of space professionals conducted in 2012 and 2022. The results show a rise …


2024 July 25 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University Jul 2024

2024 July 25 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.


Strategic Value And Scientific Exploration Of In-Situ Pyrolysis Of Tar-Rich Coals, Wang Shuangming, Shi Qingmin, Sun Qiang, Cui Shidong, Kou Bingyang, Qiao Junwei, Geng Jishi, Zhang Lei, Tian Hua, Jiang Pengfei, Cai Yue, Liu Lang Jul 2024

Strategic Value And Scientific Exploration Of In-Situ Pyrolysis Of Tar-Rich Coals, Wang Shuangming, Shi Qingmin, Sun Qiang, Cui Shidong, Kou Bingyang, Qiao Junwei, Geng Jishi, Zhang Lei, Tian Hua, Jiang Pengfei, Cai Yue, Liu Lang

Coal Geology & Exploration

Background Given China's significant demand shortfall of oil and gas, numerous constraints on oil and gas supply, an arduous task of green and low-carbon energy transition of coals, tar-rich coals, a type of coal resource integrating the properties of coal, oil, and gas, have great potential for increasing the oil and gas supply of the country. Advances Despite the successful engineering test conducted in Yulin, Shaanxi Province, in-situ pyrolysis of tar-rich coals remains in its exploratory stage. This technology holds great strategic value in two aspects: (1) It enables reduced demand shortfall of oil and gas in China to enhance …


Strong Gelfand Pairs Of Some Finite Groups, Joseph E. Marrow Jul 2024

Strong Gelfand Pairs Of Some Finite Groups, Joseph E. Marrow

Theses and Dissertations

Strong Gelfand pairs describe a relation between a group and a subgroup, using a relation between inner products of their characters. We find all strong Gelfand pairs of the dihedral and dicyclic groups, and several of the sporadic groups. We provide some results for the strong Gelfand pairs of the affine linear groups, in addition to the exceptional classical groups $\mathrm{Sp}_4(q)$ for $q$ a power of $2$.


Variable Radio Emission Of Neutron Star X-Ray Binary Ser X–1 During Its Persistent Soft State, E. C. Pattie, Thomas J. Maccarone, Alexandra J. Tetarenko, James C. A. Miller-Jones, Manuel Pichardo Marcano, Liliana E. Rivera Sandoval Jul 2024

Variable Radio Emission Of Neutron Star X-Ray Binary Ser X–1 During Its Persistent Soft State, E. C. Pattie, Thomas J. Maccarone, Alexandra J. Tetarenko, James C. A. Miller-Jones, Manuel Pichardo Marcano, Liliana E. Rivera Sandoval

Physics and Astronomy Faculty Publications and Presentations

Ser X–1 is a low-mass neutron star X-ray binary and has been persistently accreting since its discovery in the 1960s. It has always been observed to be in a soft spectral state and has never showed substantial long-term X-ray variability. Ser X–1 has one previous radio observation in the literature in which radio emission was detected during this soft state, which is contrary to the behavior of black hole X-ray binaries. We have recently obtained 10 randomly sampled radio epochs of Ser X–1 in order to further investigate its anomalous soft-state radio emission. Out of 10 epochs, we find 8 …


The Arbitrariness Of Symmetry In Mathematical Proofs, Melisa Vivanco Jul 2024

The Arbitrariness Of Symmetry In Mathematical Proofs, Melisa Vivanco

Philosophy Faculty Publications and Presentations

Symmetry is not an inherent characteristic of mathematical proofs; instead, it is a property that arbitrarily manifests in different modes of presentation. This arbitrariness leads to the conclusion that symmetry cannot be part of the defining or essential properties that characterize proofs. Consequently, contrary to some authors’ claims, symmetry does not significantly contribute to the validity, accuracy, or soundness of mathematical proofs. What is more, it does not even play any critical role in heuristic aspects such as explanatory power. The examples developed in this paper constitute compelling evidence supporting these claims.


Documentation Of Norm Negotiation In A Secondary Mathematics Classroom, Michelle R. Bagley Jul 2024

Documentation Of Norm Negotiation In A Secondary Mathematics Classroom, Michelle R. Bagley

Theses and Dissertations

While previous mathematics education research has shown that norms can change in mathematics classrooms, little research has closely documented the struggles, concessions, and compromises involved in the negotiation process. Negotiating norms is a complex process entailing deliberate teacher moves intended to promote norms, often met with misunderstandings or resistance from students. This thesis documented the negotiation process that occurred when a teacher attempted to require conceptual explanations from students who had not previously been accustomed to doing so. I recorded six days of instruction in a 9th grade algebra unit, transcribed the class discussions, and inferred norms "at play" for …


The Potential Influence Of Immune Modulatory Molecules (Tgf-Βiii And Ctla-4) In Pathogenicity Of Pcos, Mustafa Riyadh Abdullah, Hazima Mossa Alabassi Jul 2024

The Potential Influence Of Immune Modulatory Molecules (Tgf-Βiii And Ctla-4) In Pathogenicity Of Pcos, Mustafa Riyadh Abdullah, Hazima Mossa Alabassi

Karbala International Journal of Modern Science

Polycystic ovary syndrome (PCOS) is characterised by chronic anovulation, hyperandrogenism, polycystic ovaries, and immunological dysregulation. Immune homeostasis and inflammation management require immune functions. T-regulatory cells (Tregs) regulate PCOS's immune system, inflammation, insulin resistance, ovarian function, and homeostasis. Transforming growth factor βIII (TGF-βIII) and Cytotoxic-T-lymphocyte-associated-protein-4 (CTLA-4) receptors on the surfaces of Treg cells are important for controlling the immune system. The study included 68 PCOS patients and 22 non-PCOS women controls aged 20–45. The waist-hip ratio (WHR) determines obesity. We evaluated serum levels and gene expression of TGF-βIII and CTLA-4 via ELISA and real-time PCR. Women with PCOS had significantly higher …


Enhanced Optoelectronics Performance Of Hybrid Self Power Photodetectors Go: Tio2- Ad / N-Si Heterojunctions, Mohammed J. Alsultani, Maysoon F. Alias Jul 2024

Enhanced Optoelectronics Performance Of Hybrid Self Power Photodetectors Go: Tio2- Ad / N-Si Heterojunctions, Mohammed J. Alsultani, Maysoon F. Alias

Karbala International Journal of Modern Science

A GO:TiO2/n-Si heterostructure has been submerged in an anthocyanin dye solution that extracted from the red cabbage plant creates a high responsivity, self-powered UV, and visible photodetectors fabricated by the spray pyrolysis technique. The GO concentrations are varied, whereas TiO2 is fixed. Thin films' structure, shape, and optical characteristics were examined using X-ray diffraction, field emission scanning electron microscopy, and UV-Vis spectrophotometers respectively. Island-like polycrystalline film powders with grain boundaries and granular shapes are created. Two direct energy gaps between 3.33-3.02 and 2.39-2.04 eV exist in all films. J-V characteristics were examined. The saturation current density (J …


Uniformly Distributing Points On A Sphere, Flavio Arrigoni Jul 2024

Uniformly Distributing Points On A Sphere, Flavio Arrigoni

Rose-Hulman Undergraduate Mathematics Journal

In this paper, we are going to present and discuss different procedures for distributing points on a sphere's surface. Furthermore, we will assess their quality with three different distribution tests. The MATHEMATICA package that we created for testing and plotting the points is publicly available.


Modeling Virus Diffusion On Social Media Networks With The Smirq Model, Justin Browning, Arnav Mazumder, Gowri Nanda Jul 2024

Modeling Virus Diffusion On Social Media Networks With The Smirq Model, Justin Browning, Arnav Mazumder, Gowri Nanda

Rose-Hulman Undergraduate Mathematics Journal

As social networking services become more complex and widespread, users become increasingly susceptible to becoming infected with malware and risk their data being compromised. In the United States, it costs the government billions of dollars annually to handle malware attacks. Additionally, computer viruses can be spread through schools, businesses, and individuals’ personal devices and accounts. Malware affecting larger groups of people causes problems with privacy, personal files, and financial security. Thus, we developed the probabilistic SMIRQ (pSMIRQ) model that shows how a virus spreads through a generated network as a way to track and prevent future viruses. Our model is …


Approximating Equilibria In Restricted Games, Jack W. Doyle Jul 2024

Approximating Equilibria In Restricted Games, Jack W. Doyle

Rose-Hulman Undergraduate Mathematics Journal

We consider optimal play in restricted games with linear constraints, and use ϵ-equilibria to find near-equilibrium states in these games. We present three mathematical optimization formulations -- a mixed-integer linear program (MILP), a quadratic program with linear constraints (QP), and a quadratically constrained program (QCP) -- to both approximate and identify these states. The MILP has a short runtime relative to the QP and QCP for large games (a factor 100 faster for |S|=9) and exhibits linear growth in run time, but provides only relatively weak upper bound. The QP and QCP provide a tight bound and the precise value …


Monotone Functions On General Measure Spaces, Alejandro Santacruz Hidalgo Jul 2024

Monotone Functions On General Measure Spaces, Alejandro Santacruz Hidalgo

Electronic Thesis and Dissertation Repository

Given a measure space and a totally ordered collection of measurable sets, called an ordered core, the notion of a core decreasing function is introduced and used to generalize monotone functions to general measure spaces. The least core decreasing majorant construction, the level function construction, and the greatest core decreasing minorant, already known for functions on the real line, are extended to this general setting. A functional description of these constructions is provided and is shown to be closely related to the pre-order relation of functions induced by integrals over the ordered core.

For an ordered core, the down space …


Constraining The Evolutionary Stages Of A Hypogene Karst System By Combining Morphological, Geochemical And Geochronological Data - The Example Of Carbonate Breccia-Hosted Melnička Peštera, Marjan Temovski, Zsófia Ruszkiczay-Rüdiger, Kata Molnár, László Rinyu, Alexander Wieser, Oscar Marchhart, László Palcsu Jul 2024

Constraining The Evolutionary Stages Of A Hypogene Karst System By Combining Morphological, Geochemical And Geochronological Data - The Example Of Carbonate Breccia-Hosted Melnička Peštera, Marjan Temovski, Zsófia Ruszkiczay-Rüdiger, Kata Molnár, László Rinyu, Alexander Wieser, Oscar Marchhart, László Palcsu

International Journal of Speleology

A combination of morphological observations, geochemical data from calcite minerals and geochronology by burial age dating and U-series is used to constrain the geological and geomorphological setting and the evolutionary stages of a hypogene karst system. This methodological suit is applied to Melnička Peštera, a horizontal cave developed in carbonate breccia overlying dolomite marble in Melnica locality (N. Macedonia), where hydrothermal karst development occurred in both dolomite and calcite marble. The passage morphology of the cave, having a reverse triangle, Laughöhle cross-sections, suggests development near the water table by slowly moving waters. Calcite crusts are found throughout the cave, and …


Co2 Hypogene Speleogenesis In An Endogenic Travertine System, Mesa Del Oro, New Mexico, Usa, Victor J. Polyak, Jeffrey R. Forbes, Michael N. Spilde, Paula P. Provencio, John R. Cochran, Yemane Asmerom Jul 2024

Co2 Hypogene Speleogenesis In An Endogenic Travertine System, Mesa Del Oro, New Mexico, Usa, Victor J. Polyak, Jeffrey R. Forbes, Michael N. Spilde, Paula P. Provencio, John R. Cochran, Yemane Asmerom

International Journal of Speleology

The Mesa del Oro travertine, deposited by upwelling CO2-rich spring waters, is a large and thick mantle of calcite overlying soft Triassic Chinle Formation mudstones in western central New Mexico, USA. The travertine contains a system of small caves known as the Pronoun Cave Complex. Whut Cave is the largest known cave in the complex. While the travertine hydrologic system is no longer active, there is ample evidence that Whut Cave was formed by hypogene speleogenesis. The Whut Cave entrance is a small roughly circular shaft that descends ~four meters and intersects a linear fissure-controlled passage. Mn-oxide was …


Quantum Classical Algorithm For Solving The Hubbard Model Via Dynamical Mean-Field Theory, Anshumitra Baul Jul 2024

Quantum Classical Algorithm For Solving The Hubbard Model Via Dynamical Mean-Field Theory, Anshumitra Baul

LSU Doctoral Dissertations

Modeling many-body quantum systems is widely regarded as one of the most promising applications for near-term noisy quantum computers. However, in the near term, system size limitation will remain a severe barrier for applications in materials science or strongly correlated systems. A promising avenue of research is to combine many-body physics with machine learning for the classification of distinct phases. I present a workflow that synergizes quantum computing, many-body theory, and quantum machine learning (QML) for studying strongly correlated systems. In particular, it can capture a putative quantum phase transition of the stereotypical strongly correlated system, the Hubbard model. Following …


Resonant Solutions Of The Non-Linear Schrödinger Equation With Periodic Potential, Arein Duaibes, Yulia Karpeshina Jul 2024

Resonant Solutions Of The Non-Linear Schrödinger Equation With Periodic Potential, Arein Duaibes, Yulia Karpeshina

Mathematics Faculty Publications

The goal is construction of stationary solutions close to non-trivial combinations of two plane waves at high energies for a periodic non-linear Schrödinger Equation in dimension two. The corresponding isoenergetic surface is described for any sufficiently large energy k2. It is shown that the isoenergetic surface corresponding to k2 is essentially different from that for the zero potential even for small potentials. We use a combination of the perturbative results obtained earlier for the linear case and a method of successive approximation.


A Fresh Take: Seasonal Changes In Terrestrial Freshwater Inputs Impact Salt Marsh Hydrology And Vegetation Dynamics (Estuaries And Coasts, (2024), 10.1007/S12237-024-01392-1), Maya S. Montalvo, Emilio Grande, Anna E. Braswell, Ate Visser, Bhavna Arora, Erin C. Seybold, Corianne Tatariw, John C. Haskins, Charlie A. Endris, Fuller Gerbl Jul 2024

A Fresh Take: Seasonal Changes In Terrestrial Freshwater Inputs Impact Salt Marsh Hydrology And Vegetation Dynamics (Estuaries And Coasts, (2024), 10.1007/S12237-024-01392-1), Maya S. Montalvo, Emilio Grande, Anna E. Braswell, Ate Visser, Bhavna Arora, Erin C. Seybold, Corianne Tatariw, John C. Haskins, Charlie A. Endris, Fuller Gerbl

School of Earth & Environment Departmental Research

Salt marshes exist at the terrestrial-marine interface, providing important ecosystem services such as nutrient cycling and carbon sequestration. Tidal inputs play a dominant role in salt marsh porewater mixing, and terrestrially derived freshwater inputs are increasingly recognized as important sources of water and solutes to intertidal wetlands. However, there remains a critical gap in understanding the role of freshwater inputs on salt marsh hydrology, and how this may impact marsh subsurface salinity and plant productivity. Here, we address this knowledge gap by examining the hydrologic behavior, porewater salinity, and pickleweed (Sarcocornia pacifica also known as Salicornia pacifica) plant productivity along …


Autumn Grass Growth- The Effect Of Rest Interval, R Neilan, E G. O'Riordan, G Keane Jul 2024

Autumn Grass Growth- The Effect Of Rest Interval, R Neilan, E G. O'Riordan, G Keane

IGC Proceedings (1993-2023)

The effect of closing dates (Experiment 1: August 1, August 14 and September 18) and grass regrowth interval (Experiment 2) on herbage yield in the autumn/winter and in the following spring were investigated on a previously grazed Lolium perenne sward. In Experiment 1, similar yields were obtained for the August 1 and August 14 closing. Yields decreased and the proportion of dead material increased from 0.19 to 0.61 between mid-October and late- December. In Experiment 2, dry matter yield increased linearly (P < 0.05) with rest interval up to 7 wks in swards closed in September. There was no significant yield advantage for rest intervals greater than 5-6 wks. It is concluded that accumulated autumn and spring yields showed increased DM production with the shorter regrowth intervals.


Improving Pasture Composition Increases Wool Returns In Eucalypt Woodlands, T J. Hall, R G. Silcock, J J. Sevil, J R. Van Der Meulen Jul 2024

Improving Pasture Composition Increases Wool Returns In Eucalypt Woodlands, T J. Hall, R G. Silcock, J J. Sevil, J R. Van Der Meulen

IGC Proceedings (1993-2023)

A sheep grazing experiment in red earth Eucalypt country on semiarid pastures dominated by either Gayndah buffel grass (Cenchrus ciliaris) or wiregrass (Aristida jerichoensis) quantified liveweight, wool production and quality, and financial returns. Wethers were grazed at 0.32 and 0.6 ha/sheep. In year 1 there was no significant effect of either stocking rate or pasture type on liveweight or wool growth rate. Vegetable fault was greater in the fleeces from the wiregrass. The sheep grazing buffel grew better than those on wiregrass when stocking rates were doubled in year 2, while pasture yields remained high. The …


Responses Of Artemisia Herba-Alba Asso. And Its Associated Species To Grazing Frequency (Midelt, Morocco), M Mejjati Alami, O Berkat, C Bensalem Jul 2024

Responses Of Artemisia Herba-Alba Asso. And Its Associated Species To Grazing Frequency (Midelt, Morocco), M Mejjati Alami, O Berkat, C Bensalem

IGC Proceedings (1993-2023)

The objective of this study (conducted in 1994) was to assess the effects of season and grazing frequency (control, continuous, intermittent during 2 days per week) on vegetation attributes, and animal feeding behavior. Mean standing crop, for which Artemisia herba alba contributed 72%, attained 533 for the control while it was maintained at 394 and 322 Kg DM/ha, for the continuous and the intermittent grazing, respectively. Mean productivity of Artemisia herba alba varied according to treatment and had values of 5.3, 3.0 and 2.5 Kg DM/ha/day, under the ungrazed control, the continuous and the intermittent grazing regimes, respectively. Percent utilization …


Grazing Management Of An Italian Ryegrass Sward With Dairy Sheep In The Mediterranean Environment, M Sitzia, P P. Roggero, N Fois, G Molle Jul 2024

Grazing Management Of An Italian Ryegrass Sward With Dairy Sheep In The Mediterranean Environment, M Sitzia, P P. Roggero, N Fois, G Molle

IGC Proceedings (1993-2023)

A grazing experiment was conducted in North-West Sardinia with the aim of testing the sward height as a mean to set up an efficient spring management of Italian ryegrass (Lolium multiflorum Lam.). Three fields were continuously grazed during spring 1992 by three groups of 12 dairy Sarda ewes, at three different sward heights (SH): 30 - 60 - 90 mm. The target sward height was obtained by continuously adjusting the field sizes. The results showed that the different grazing managements influenced the above ground biomass production and partitioning of the Italian ryegrass and the animal performances. During the vegetative …


Estimation Of Herbage Intake Of High Producing Milking Cows Under Intensive Grazing With A Supplementary Feeding Method In Northern Japan, K Ohiai, K Sudo, T Ikeda, T Honma Jul 2024

Estimation Of Herbage Intake Of High Producing Milking Cows Under Intensive Grazing With A Supplementary Feeding Method In Northern Japan, K Ohiai, K Sudo, T Ikeda, T Honma

IGC Proceedings (1993-2023)

The objective of this study was to estimate the herbage intake and to assess a supplementary feeding method for high producing milk cows under intensive grazing. Eight high producing milking cows were grazed rotationally on perennial ryegrass (Lolium perenne L) dominant mixed pasture and on meadow fescue (Festuca elatior L) dominant mixed pasture, changing rotation period and grazing area ccording to seasonal pasture growth rate. Pasture intakes were estimated to be about 2% of body weight by TDN requirements estimation of animals. A supplementary feeding method is examined to be proper for high producing milking cows under …


Palatability Of Grasses And Grazing On Hungarian Grassland, Z Barcsak, I Kertesz, L Szeman Jul 2024

Palatability Of Grasses And Grazing On Hungarian Grassland, Z Barcsak, I Kertesz, L Szeman

IGC Proceedings (1993-2023)

Grasslands provide the most basic and cheapest forage diet for cattle. The palatability studies were carried out on pure and mixed swards sown in 1990 on the GATE experimental farm. The studies involved the following 12 species: Lolium perenne, Trifolium repens, Festuca arundinacea, Festuca rubra, Poa pratensis, Festuca pratensis, Bromus inermis, Phalaris arundinacea, Lotus corniculatus, Agropyron crystatum, Dactylis glomerata and a mixed sward. During the study the morning and afternoon grazings were investigated with the involvement of 60 Limousin cattle. The following observations were made: 1. On the basis of our ethological observations regarding the bite rates the animals found …


Selective Sheep Grazing In An Heterogeneous Wheatgrass Dominated Pasture Related To Stocking Rate, G L. Siffredi, M A. Brizuela, M S. Cid, C Cangiano Jul 2024

Selective Sheep Grazing In An Heterogeneous Wheatgrass Dominated Pasture Related To Stocking Rate, G L. Siffredi, M A. Brizuela, M S. Cid, C Cangiano

IGC Proceedings (1993-2023)

It has been hypothesized that patch and community selection are driven by forage quality and/or quantity. We assess the relationship between vegetation characteristics and community and patch selection by sheep under continuous grazing at different stocking rates in an heterogeneous pasture. Our results suggest that when communities strongly differed in nutritive value sheep recurrently select the higher quality community in spite of its low biomass. However, sheep do not completely exclude the poorer quality community, generating a patchy vegetation pattern.


Grazing Management Of Elephant-Grass For Milk Production, F Deresz, L L. Matos Jul 2024

Grazing Management Of Elephant-Grass For Milk Production, F Deresz, L L. Matos

IGC Proceedings (1993-2023)

The objectives of these experiments were to study the effects of three resting periods (RP) of elephant-grass pasture on milk production and composition of Holstein-Zebu cows. These trials were carried out during two consecutive rainy seasons (December to May) using 24 cows in each year. They were randomly assigned by blocks according to milk yield and live weight (LW) to four treatments: 30- day RP with no concentrate (30N), 30-day RP with concentrate (30C), 36 and 45-day RP with C (36C and 45C) in the first year. In the second year the treatments were: 30C, 30N, 36N and 45N. Concentrate …