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Impact of Tillage and Fertilizer Application Method on Gas Emissions in a Corn Cropping System

Pedosphere 2012年第5期22卷 604-615页

作者： k. smith D. WATTS T. WAY H. TORBERT S. PRIOR Department of Math Science and Technology University of Minnesota Crookston Crookston MN 56716 (USA) USDA-ARS National Soil Dynamics Laboratory 411 S. Donahue Dr. Auburn AL 36832 (USA)

Tillage and fertilization practices used in row crop production are thought to alter greenhouse gas emissions from soil. This study was conducted to determine the impact of fertilizer sources, land management practices, and fertilizer placement methods on greenhouse gas （CO2, CH4, and N2O） emissions. A new prototype implement developed for applying poultry litter in subsurface bands in the soil was used in this study. The field site was located at the Sand Mountain Research and Extension Center in the Appalachian Plateau region of northeast Alabama, USA, on a Hartsells fine sandy loam （fine-loamy, siliceous, subactive, thermic Typic Hapludults）. Measurements of carbon dioxide （CO2）, methane （CH4）, and nitrous oxide （N20） emissions followed GRACEnet （greenhouse gas reduction through agricultural carbon enhancement network. protocols to assess the effects of different tillage （conventional vs. no-tillage） and fertilizer placement （subsurface banding vs. surface application） practices in a corn （Zea mays L.） cropping system. Fertilizer sources were urea-ammonium nitrate （UAN）, ammonium nitrate （AN） and poultry litter （M） applied at a rate of 170 k. ha^（-1） of available N. Banding of fertilizer resulted in the greatest concentration of gaseous loss （CO2 and N2O） compared to surface applications of fertilizer. Fertilizer banding increased CO2 and N2O loss on various sampling days throughout the season with poultry litter banding emitting more gas than UAN banding. Conventional tillage practices also resulted in a higher concentration of CO2 and N2O loss when evaluating tillage by sampling day. Throughout the course of this study, CH4 flux was not affected by tillage, fertilizer source, or fertilizer placement method. These results suggest that poultry litter use and banding practices have the potential to increase greenhouse gas emissions.

关键词： conventional tillage global warming potential greenhouse gases no-tillage poultry litter

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The discipline of teams

The discipline of teams

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作者： Jon R. k.tzenbach and Douglas k. smith.

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Discovery of β-HIO3: A Metastable Polymorph of HIO3

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Advances in Materials Physics and Chemistry 2018年第5期8卷 246-256页

作者： Dylan k. smith Daniel k. Unruh Michelle L. Pantoya Department of Mechanical Engineering Texas Tech University Lubbock USA Department of Chemistry Texas Tech University Lubbock USA

The β-HIO3 polymorph, previously difficult to detect and whose existence was questioned, has been structurally characterized. The crystal structure of β-HIO3 was solved in the same space group as α-HIO3 (P212121);however, it was found that the unit cell axes were all different by about 1 Å. Similar to that of α and γ phases, the unit cell contains only a single HIO3 molecule in the asymmetric unit with I-O bond lengths ranging from 1.786(5) to 1.903(7) Å. The I(V) atom is further coordinated by three oxygen atoms of neighboring acid molecules forming a distorted octahedral with a range of I-O distances (2.498(6) - 2.795(7) Å). The one structural difference that separates the β phase from the α and γ phases is that the hydroxyl group is bridging between two I(V) atoms, resulting in a smaller hydrogen bonding distance (O-O distance: 2.559 Å(β), 2.665 Å(γ) and 2.696 Å(α)) and presumably a different crystalline energy. Similar to γ-HIO3, β-HIO3 is metastable and slowly converts to α-HIO3. It is hypothesized that β-HIO3 is a transition step in the formation of α-HIO3 and β-HIO3 is a result of trapped water inside particles during crystallization.

关键词： X-Ray Diffraction Iodates Acids Crystal Structure Oxides

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光化-动力耦合重力波模式及其应用——Ⅱ.稳定传播的重力波对中层顶区化学成分分布的影响

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中国科学：数学 2001年第S1期39卷 149-156页

作者：徐寄遥马瑞平 A. k. smith 中国科学院空间科学与应用研究中心空间天气学开放实验室 NCAR P. O. Box 3000 Boulder CO 80307 USA

利用包含光化学过程的、非线性的、可压缩的二维重力波模式研究了中层顶区重力波对大气微量化学成分分布的影响,着重模拟了重力波穿过中层顶区时,通过非线性化学过程引起的大气氧族和氢族成分分布的改变.研究发现,当重力波通过中层顶时... 详细信息

利用包含光化学过程的、非线性的、可压缩的二维重力波模式研究了中层顶区重力波对大气微量化学成分分布的影响,着重模拟了重力波穿过中层顶区时,通过非线性化学过程引起的大气氧族和氢族成分分布的改变.研究发现,当重力波通过中层顶时,即使它不发生破碎,也仍然能够产生大气化学成分平均分布的变化,并且夜间该效应比白天更为强烈.

关键词：重力波光化学中层顶中高层大气

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光化-动力耦合重力波模式及其应用——Ⅰ.模式的建立

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中国科学：数学 2001年第S1期39卷 142-148页

作者：徐寄遥马瑞平 A. k. smith 中国科学院空间科学与应用研究中心空间天气学开放实验室 NCAR P. O. Box 3000 Boulder CO 80307 USA

利用数值模拟的方法研究了大气重力内波传播的扰动对中间层上部和低热层大气化学成分分布的影响.着重探讨非线性、可压缩的二维光化-动力耦合重力波模式的建立、计算方法以及模式正确性分析.该模式考虑了光化学反应产生的非绝热效应以... 详细信息

利用数值模拟的方法研究了大气重力内波传播的扰动对中间层上部和低热层大气化学成分分布的影响.着重探讨非线性、可压缩的二维光化-动力耦合重力波模式的建立、计算方法以及模式正确性分析.该模式考虑了光化学反应产生的非绝热效应以及重力波对大气化学反应和对化学成分输运的影响.模式在水平方向利用拟谱方法,对垂直方向和时间采用有限差分方法,并利用FICE方法对模式求解.对小振幅波动的模拟结果与线性重力波理论结果符合得很好,证明了该模式算法的正确性,它表明拟谱法和有限差分法相结合是大气重力波模拟研究的有效的、并且计算量较小的方法之一.

关键词：重力波光化学非线性数值模拟

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Clinical Presentations of Pediatric Horner Syndrome

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Open Journal of Ophthalmology 2017年第1期7卷 37-43页

作者： Frank.e k. smith Geetanjali Rathore Donny W. Suh University of Nebrask. Medical Center Omaha USA Children’s Hospital and Medical Center Omaha USA Department of Pediatrics and Neurology University of Nebraska Medical Center Omaha USA Department of Ophthalmology and Visual Sciences University of Nebraska Medical Center Omaha USA

Purpose: To understand the multiple signs of Horner syndrome and to recommend protocols for pediatricians to obtain an accurate diagnosis of Horner syndrome. Methods: The medical records of 17 pediatric patients with Horner syndrome, neonates to eighteen years of age, were collected and analyzed. Data recorded included age, presenting symptoms, other medical history, allergies, medications, pupil size, presence of anhidrosis, and presence of ptosis. From the available pupil sizes, average degree of anisocoria was calculated. Results: All 17 patients had other clinical findings of Horner syndrome in addition to anisocoria. On initial evaluation, 100% had ptosis and 25% had anhidrosis. Of the available pupil size data, the average level of anisocoria was 2.06 mm, with a standard deviation of 1.17 mm. Conclusion: Physicians are reminded to measure pupil size to determine the degree of anisocoria when present, as it may help distinguish benign conditions from underlying pathology. Educating pediatricians on measurement of anisocoria and additional signs of Horner syndrome will help with proper referral patterns.

关键词： Horner Syndrome Anisocoria Ptosis Anhidrosis Pediatric

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Finishing Cattle in All-Natural and Conventional Production Systems

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Open Journal of Animal Sciences 2020年第2期10卷 237-253页

作者： Zachary k. smith Peter T. Anderson Bradley J. Johnson Department of Animal Science South Dakota State University Brookings SD USA Midwest PMS LLC Firestone CO USA Department of Animal and Food Sciences Texas Tech University Lubbock TX USA

Beef cattle producers in the North America have a variety of production and mark.ting options and must choose the best production system for their situation. This review describes considerations involved in choosing between feeding cattle conventionally versus feeding them in programs that prohibit the use of certain technologies. Data from peer-reviewed journals, extension publications, nutritional consultants, governmental organizations, and feed companies were used to construct this review. Most cattle in North America are fed in conventional production systems. Conventional beef production systems typically use steroidal implants, ionophores, and beta-adrenergic agonists to improve animal productivity;as well as feed grade and injectable antimicrobials to control, treat or prevent disease and improve animal health. These technologies have been shown to lower the cost of production, allowing for beef to be competitive in the global protein mark.t. Some consumers have expressed a preference for beef produced without these technologies. These “All-natural” (AN) cattle may bring a premium price in the mark.t. The economic impact of differing productions systems can be described in relation to 1) cost of production, 2) operating costs of the feedlot, 3) price paid for feeder calves, and 4) price received for fed cattle. Conventional production provides the most favorable outcome for factors 1, 2, and 3, while AN production provides the most favorable outcome for item 4. There are also industry wide and societal aspects related to differing beef production systems related to health and safety of beef, land use, and cost of production allowing for a greater share of the global protein mark.t. Technologies used in conventional production are critical tools to North American beef production. Differences in efficiencies between each type of non-conventional production systems must be re-captured in added premiums when cattle are mark.ted and sold. Premiums for AN cattle a

关键词： All-Natural Beef Beta-Adrenergic Agonist Conventional Ionophore

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Microelectronic Circuits 5th ed.

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2004年

作者： Adel S. Sedra k. C. smith

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ROTOR INTERFERENCE IN SCREW COMPRESSORS

ROTOR INTERFERENCE IN SCREW COMPRESSORS

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第三届国际压缩机技术会议

作者： Professor N. Stosic Professor lan k. smith Mr A. k.vacevic Centre for Positive Displacement Compressor Technology City University Centre for Positive Displacement Compressor Technology City University Centre for Positive Displacement Compressor Technology City University

＜正＞Small rotor clearances are today a vital prerequisite for an efficient screw compressor. The clearances are mainly responsible for compressor leak.ges, a small clearance will minimize them and thereby increase both, the volumetric and adiabatic efficiency. A continuous improvement in the rotor manufacturing equipment has been achieved during the recent years and tight production tolerances may now be applied to compressor rotors. This imposes a new approach upon the design of compressor elements, such as the rotor and bearing housings and bearings to respond properly to this challenge. A mathematical apparatus to quantify eventual rotor interference in screw compressors due to the bearing clearance and the imperfections in compressor housing manufacturing is presented in this paper an applied for identification of their significance and influence upon the screw compressor behaviour. The analysis based on this approach has shown that the rotor interference may have negative, either static or dynamic effects on the compressor efficiency, safety, endurance and reliability and enhancing compressor noise.

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Body Weight and Steroidal Implants Impact Animal Growth Performance, Sera Metabolites, and Pulmonary Arterial Pressure in Feedlot Cattle

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Open Journal of Animal Sciences 2020年第3期10卷 414-430页

作者： Tyler A. Vogel Joseph M. Neary Zachary k. smith Bradley J. Johnson Department of Animal and Food Science Texas Tech University Lubbock TX USA Department of Animal Science South Dakota State University Brookings SD USA

The study objective was to evaluate steer growth performance, sera metabolite responses, carcass characteristics, and pulmonary arterial pressure as affected by body weight at time of implantation and steroidal implant administration. Crossbred steers (n = 20) were used in a 2 × 2 factorial arrangement of treatments in a completely randomized design experiment, Factors included: body weight: light (L), or heavy (H) and implant: Non-implanted (NoIMP), or Implanted (IMP) with steer serving as the experimental unit for all analyses. Initial weights for L and H steers were 398 ± 27.6 and 547 ± 25.2 k., respectively. Implanted steers received a terminal implant (200 mg trenbolone acetate and 20 mg estradiol-17β;Revalor-200;Merck.Animal Health, Madison, NJ) on d 0. Cattle within treatments were group housed in common pens (n = 5 steers/pen). Bodyweight, blood samples, and pulmonary arterial pressure were collected on d 0, 14, 35, 70 and 104. Cattle were fed a common diet once daily to provide ad libitum access to feed. The finishing diet contained (DM basis) 13.3% CP, 2.13 Mcal/k. NEm, and 1.45 Mcal/k. NEg. Growth performance (body weight and ADG) and carcass traits were analyzed using the MIXED procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC). Sera metabolites were analyzed as repeated measures over time, with day as the repeated measure. For all analyses, α level k. more per head of DM daily than L cattle and IMP steers consumed 1.0 k. more DM daily than NoIMP steers. Cumulative ADG did not differ between the L and H steers (1.41 vs. 1.52 ± 0.060 k.;P = 0.20). Implanting increased (P k.). No differences (P > 0.05) in ADG were observed in NoIMP vs. IMP cattle beyond d 70 (1.21 vs. 1.01 ± 0.16 k.;P = 0.38). Sera urea-N concentrations were decreased (P < 0.01) in L cattle subjected to IMP during the study and tended to increase over time for the other treatments. Ribfat, HCW,

关键词： Cattle Estradiol Pulmonary Pressure Trenbolone

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