bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Azipod Propulsion for High Power Arctic Offshore Vessels
Authors: Hanninen Samuli , Heideman Torsten , Tenhunen Erno
Published: December 2012

The traffic volumes in arctic waters are expected to grow rapidly in thenear future. New fleets of oil and LNG carriers as well as ice classeddrillships and offshore supply vessels and icebreakers with high ice-class areneeded for the transportation and oil exploration. The recent growth inactivities in the Arctic region has materialized in several projects, whereAzipod propulsion system is playing an important role in making the projectstechnically possible and economically feasible. Azipod propulsion offers a veryattractive and efficient propulsion solution for most of these vessels. However, there is an evident need for azimuthing propulsion units with power inexcess of 15 MW with highest ice classes, such as the " new" IACS PC1.

In response to the market demand ABB Marine has recently developed an Azipodpropulsion concept with high power to meet the requirements of the high arcticice classes.

This paper will outline some important design considerations during thedevelopment work, such as:–different ice class rule requirements–need for overload / overtorque capacity of the electric propulsion motor inice–utilisation of measurements from full-scale ice trials with poddedpropulsion

High power Azipod propulsion systems help the shipowners to accessopportunities in the Arctic areas by providing safe and reliable operation inthe region. With ABB electric propulsion and Azipod units, the shipowner getsequipment designed to meet the demanding Arctic requirements and which isproven to be reliable in ensuring safe navigation in the sensitive Arcticseas.
Vibratory Driven Piles in Cold Permafrost
Authors: Mayrberger T. , Braun K. , Scott W.N. , Cologgi J.
Published: December 2012

A two-year-long field study was conducted by ConocoPhillips Alaska, Inc. andPND Engineers, Inc., at Kuparuk in Alaska's arctic North Slope region. Thestudy verified that pipe piles can be directly driven into predrilled pilotholes in frozen ground, without requiring thermal modification of thepermafrost. The traditional " drill-and-slurry" method of permafrost pileinstallation involves hanging piles in an oversize hole and backfilling theannulus with a sand/water slurry. Vibratory driven pile installation isconsiderably more efficient with large benefits in installation time, expenses, and safety. Both methods require an adequate adfreeze bond for pileperformance. The objective of this testing program was to determine whetherdespite great benefits in installation efficiency the vibratory driven pilewould perform adequately. Twelve 12.75-inch-diameter steel pipe piles wereinstalled in permafrost in the Alaskan arctic; eight piles were installed inice-rich sandy silt and four piles were installed in a frozen gravel soil. Piles were loaded in tension for six different durations ranging from five daysto six months at loads varying from 35 kips to 145 kips. At the completion oflong-term testing, the test piles were unloaded, rested, and then loaded tofailure to characterize the adfreeze short-term strength. Pile load anddisplacement were continuously recorded with electronic displacement and loadtransducers. Subsurface soil temperatures were also monitored. Collected datawas used to characterize long- and short-term pile velocity as a function ofload and adfreeze temperature. Experimental results were compared to currenttheoretical and empirical performance.
Power Distribution for Arctic Subsea Tiebacks
Authors: Hazel Terence , Woodroffe Adrian
Published: December 2012

Subsea tiebacks are becomingincreasingly prevalent in oil and gas field developments. As the accessibilityof the production from wellheads becomes more difficult, the need for subseacompression and pumping increases. Compression and pumping require significantpower which can be distributed and controlled from a HVSS (High-Voltage SubseaSubstation). The viability of an Arctic field development will be determined bythe reliability of all elements in the tieback and in particular, thecentralized subsea power distribution system.

Introduction

This paper presents the conceptual design and capabilities of a modular, expandable and highly reliable subsea HV (High Voltage, U > 1000V)and LV (Low Voltage, U £ 1000V) power distribution system. The assemblyis designed to operate without intervention for extended periods of time and isideally suited to emerging green field developments in the Arctic. The conceptis built from components and subsystems each with a technology readiness levelof six or seven and is therefore well positioned for a prototype build anddeployment with minimal additional qualification.

The core switchgear is built around proven 36kV CBs (Circuit-Breakers)connected together via an SF6-insulated bus bar. The use ofSF6 as a dielectric medium allows the size of the CBs and bus barpressure vessel to be minimized, reducing the mass and thus deploymentconstraints of the assembly. Connections to the switchgear assembly for boththe incoming power feed and switched outputs are via wet mate connectors. Theonly components in the main pressure vessel are the CBs, current transformers, voltage transformers and busbars.

To maximize the overall system availability, the control and protectionsystems for each 36kV CB are redundant and housed in a series ofrecoverable modules rather than inside the main HV switchgear pressure vessel. Should there be a fault in the control and protection system, the redundancy isdesigned such that a faulty module can be replaced without loss of control ofits associated 36kV CB, thus maintaining production availability.

A key and unique feature of this switchgear assembly design is the abilityto power all of the protection, control and communication equipment independentof the main HV AC power. This is achieved by including two high voltage directcurrent and fiber optic cables in the umbilical. At the switchgear module, theHV DC voltage is stepped down to LV DC via a pair of redundant nodes thatdistribute auxiliary power and communication capabilities to the subseaequipment. By independently powering the control and monitoring system, thestatus and position of each CB can be known during a black start without theneed for a subsea battery-supplied UPS (Uninterruptible Power System). Inkeeping with the simple and robust design philosophy, only critical telemetryis provided to monitor and control the system. Where telemetry is provided, itis also redundant
A Constellation Of Satellites For Enhanced Mapping Of Sea Ice
Authors: Davidson Malcolm , Walker Nick , Williams Chris , Power Desmond , Ramsay Bruce , Partington Kim , Barber David , Arkett Matt , De Abreu Roger
Published: December 2012

In conducting safe and cost effective operations in ice prone waters, icemanagement and risk mitigation practices are integral to operations. A criticalelement in ice management is the mapping and characterisation of sea ice. Satellite synthetic aperture radar (SAR) is a standard tool used by icecharting agencies to map the extent of sea ice. Wide-swath SAR has become thepreferred sensor of choice for ice mapping and the collection of data regardingice parameters. SAR provides a high degree of information content on basic iceparameters such as concentration, type and topography. SAR can be used tocharacterise different sea ice types, such as multi-year versus first year ice, and the use of multiple SAR frequencies (L, C and X-Band) can reduceinterpretation ambiguities during the melt season. The advent ofmulti-frequency and polarization SAR systems, acting as a constellation, isseen as an important next step in the evolution of sea ice monitoring. Theevaluation of a SAR ice constellation is an interesting challenge since aquantitative evaluation is necessary. As a consequence, a sea ice backscattertool has been developed that provides a figure of merit estimation of iceclassification from a constellation scenario. The authors have used its sea-icebackscatter tool to simulate various ice constellation scenarios. Thesescenarios will be presented in the context of their utility and versatility inoil and gas operations. The implementation of a SAR ice constellation providesthe opportunity to significantly expand the ice information extractioncapabilities, over and above that of these systems acting alone. In the contextof its use within Arctic resource development, SAR constellations offerenhanced ice charting to the oil and gas industry.

Index Terms—Sentinel-1, SAR, sea-ice, backscatter, constellations

Introduction

In conducting safe and cost effective operations in ice prone waters, icemanagement and risk mitigation practices are integral to operations. A criticalelement in ice management is the mapping and characterisation of sea ice. Satellite synthetic aperture radar (SAR) is a standard tool used by icecharting agencies to map the extent of sea ice. Wide-swath SAR has become thepreferred sensor of choice for ice mapping and the collection of data regardingice parameters. SAR provides day-night, all-weather capability and relativelyhigh resolution. Additionally, SAR can provide a high degree of informationcontent on basic ice parameters such as concentration, type and topography.
Image Analysis Techniques for High Arctic, Deepwater Operation Support
Authors: Blunt J.D. , Garas V.Y. , Matskevitch D.G. , Hamilton J.M. , Kumaran K.
Published: December 2012

Safe and economic hydrocarbon exploration, development and productionoperations in the high arctic deepwater require a nuanced understanding of thesea ice environment. Robust image analysis techniques provide methods bywhich this nuance can be more objectively characterized and used for decisionmaking while in operations. Morphological segmentation and windowedstatistical analysis are proposed as two approaches that provide usefulinformation on the tactical scale by rapidly characterizing floe fieldmorphology and relative surface roughness. Their use is demonstratedwithin the context of actual high arctic field program data. Results fromthe method application are shown and the benefits and limitations of their useare discussed.

Introduction

A significant hydrocarbon reserve is believed to exist in the higharctic. Hamilton [2011] used U.S. Geological Survey data [Bird et al.2008] to estimate that 40 billion bbl of oil could lie in the high arcticdeepwater (defined as water depths >100m). A vision for addressingthe technical challenges associated with safe and economic floating drilling inthe high arctic was also defined. With respect to execution of icemanagement operation support, Hamilton et al. [2011] and Younan et al. [2012]begin to address these technical challenges by defining a near-field icebreakertasking process control framework and a far-field risk characterization / alertsystem framework respectively. Selected image analysis techniques areproposed as a means to build on this ice management framework by improving theobjectivity with which far-field sea ice characterization and decision makingcan be conducted while in operations.

The proposed use of automated and semi-automated digital analysis techniquesto improve the consistency and speed of sea-ice data analysis is notnecessarily novel. Kwok et al. [1992] and Kwok [2004] demonstratedautomated segmentation methods for distinguishing between first-year ice (FYI)and multi-year ice (MYI) with synthetic aperture radar (SAR) satellitedata. The first iterations of this method used clustering to segment theimage and then a rule based look-up table (LUT) to classify image pixels. The later versions of this effort incorporated data fusion through the use ofsatellite based SSM/I and AMSR-E passive microwave and QuikSCAT radar data toimprove ice concentration and MYI classification respectively. The U.S. National Ice Center, under sponsorship of the U.S. Navy, U.S. Coast Guard andNational Oceanic and Atmospheric Administration has developed ARKTOS [Gineriset al. 2000] that uses SAR and passive microwave SSM/I data with watershedsegmentation and rule based classification.
Ice Information Services in the Era of Multiple SAR Satellites and Advanced Numerical Models
Authors: Carrieres T. , Langlois D.
Published: December 2012

Marine ice represents one of the greatest hazards to offshore developmentand transportation. While some operations may not tolerate the presence of anyice; others may only be affected by the most significant ice features such asmultiyear, heavily deformed sea ice or ice islands. With multiple SyntheticAperture Radar (SAR) and optical satellites, including RADARSAT-1 andRADARSAT-2, Envisat, Terra SAR X, NOAA NPP, etc., it is possible to have atleast daily coverage of virtually all areas of the Arctic. Ice informationservices have not only increased the accuracy of their products, but they havealso expanded the products available to include very detailed image analysesand tracking of specific ice hazards. At the same time, significant efforts inthe fields of data assimilation and modeling have started producing numericalsea ice analysis and forecast guidance products as part of routine operations. Techniques are currently under development in the field of ensemble modeling. These developments will introduce probabilistic forecast products that willprovide both improved ice information and measures of forecast confidence. These directions will enable the offshore development and transportationindustries to expand their risk management techniques to include ice andenvironmental information services. This presentation will provide a review ofthe systems under development

Background

Current ice information services provide sufficient guidance for a widevariety of marine operations to function safely. The complexity of theinformation required varies with the experience and use of the clients. Icebulletins warn of current and short term hazardous ice conditions. Daily icecharts suit the need of many users although more frequent coverage may berequired for optimal navigation. More advanced users may requiresatellite image analyses or even raw satellite images. The latter combined withshipboard marine radar and an experienced ice pilot will allow for an efficientevaluation of current and very short range ice conditions. Information on thelimitations of individual products and their day to day variations in accuracycould certainly improve their usability. Even less information is available onhow conditions will evolve even beyond 24 hours. Products are sometimesavailable on a predefined area and resolution in a limited number of productformats. Electronic charting may help in some ways but the amount ofinformation available to clients is quite limited and expensive to prepare.
Challenges Faced by the Marine Contractors Working in Western and Southern Barents Sea
Authors: Gudmestad Ove T. , Karunakaran Daniel
Published: December 2012

The Western and South Western Barents Sea is the offshore area south ofBjørnøya and east towards the newly agreed delineation boundary between Norwayand Russia while limited by the Norwegian mainland to the south.

In this area, the Snøhvit gas field is in production and the Goliat oilfield is being developed. Recently, encouraging oil finds (Skrugard and Havsul)have increased the interests in the geology and the oil and gas potential ofthe area. The older seismic (acquired more than 30 years ago) of the formerdisputed area between Russia and Norway shows potential for large hydrocarbonfinds, although there would be a possibility that the hydrocarbons might haveleaked out from the prospects.

This paper summarizes the large challenges for the marine constructioncontractors working in these areas and discusses various phenomena that affectthe marine operations at extreme cold climate conditions:Long fetch length towards the west causes long periodic waves, necessitating vessels with good motion characteristics outside the range of awide wave spectrum. Of particular importance is drilling rigs and drill shipsthat can work effectively in long periodic waves.The normal wind and wave conditions during the summer construction seasonis as for the Norwegian Sea, however, during fall and winter, the weather canbe extremely challenging. Of particular concern is the unpredictability of theweather caused by suddenly occurring polar lows, a phenomena caused by outburstof low air pressures from the ice edge to the north. The polar lows combinedwith low temperatures can cause vessel icing and loss of vessel stability forconstruction vessels with deck equipment having high centre of gravity.Furthermore, long distances and weak infrastructure lead to logisticschallenges as well as challenges related to evacuation and emergency response, in particular for activities outside the main construction season. It must alsobe noted that ice could be encountered early in the construction season, although very rarely, and that ice monitoring is important should activitiesstart as early as March and April.

The marine construction contractor will have to show patience when workingin the area. Joint efforts, improved knowledge, top standard equipment and goodunderstanding of the roles of the contractor and the oil company should, however, ensure successful project execution, also in this cold climateregion.
A New High Strength Drill Pipe Maximizing Safety and Performance in Low Temperature Environment
Authors: El Bachiri Kamal , Machecourt Philippe
Published: December 2012

The five Arctic regions of Russia, Alaska, Norway, Greenland and Canada holda tremendous potential for both discovered and undiscovered reserves of Oil andGas. The USGS estimates 160 BBO, and 1,670 TCF of natural gas reserves in theArctic, with most of these reserves being located offshore. The Arctic region, however, presents its own unique challenges; extreme low surface temperatures, a highly fragile environment protected by strict regulatory controls, very highcost of operations - and of failure prevention, and a narrow weather window tooperate. Combined, these challenges leave no room for complacency whileplanning an Arctic drilling campaign. The drilling tubular risks are mainlyaccentuated during transportation, storage, and surface handling in thepermafrost region. In order to drill safely and reliably in such harsh surfaceconditions, ordinary drillstring solution is neither considered safe norreliable due to the adverse and unpredictable effect of extereme lowtemperatures on mechanical properties of steel. VAM Drilling has successfullydeveloped and deployed proprietary Arctic steel grades that deliver a greatcombination of strength and ductilitly at temperatures as low as −60°C(−76°F).
A Novel t(2;10)(q31;p12) Balanced Translocation in Acute Myeloid Leukemia
Authors: Impera Luciana , Daniele Giulia , Marra Luisa , Baldazzi Carmen , Iacobucci Ilaria , Martinelli Giovanni , Testoni Nicoletta , Storlazzi Clelia Tiziana
Published: December 2012

We describe a case of acute myeloid leukemia M5 showing a balanced t(2;10)(q31;p12) translocation. This has never been described before as the sole cytogenetic abnormality in a bone marrow cell clone at onset. Using fluorescence in situ hybridization with properly designed bacterial artificial chromosome probes, we mapped the breakpoint regions on both derivative chromosomes 2 and 10:der(2) and der(10), respectively. The MPP7 gene, disrupted by the breakpoint on chromosome 10, was juxtaposed upstream of both HNRNA3 and NFE2L2 genes on chromosome 2, without the formation of any fusion gene. Using real-time quantitative polymerase chain reaction, we tested the possible disregulation of any of the breakpoint-associated genes as a consequence of the translocation, but we found no statistically significant alteration. Considering the potential role of this clonal cytogenetic abnormality in leukemogenesis, we speculate that this translocation could have an impact on additional genes mapping outside the breakpoint regions. However, the limited amount of RNA material available prevented us from testing this hypothesis in this present case.
A Sub-Grid Structure Enhanced Discontinuous Galerkin Method for Multiscale Diffusion and Convection-Diffusion Problems
Authors: Chung Eric T. , Leung Wing Tat
Published: December 2012

In this paper, we present an efficient computational methodology for diffusion and convection-diffusion problems in highly heterogeneous media as well as convection-dominated diffusion problem. It is well known that the numerical computation for these problems requires a significant amount of computer memory and time. Nevertheless, the solutions to these problems typically contain a coarse component, which is usually the quantity of interest and can be represented with a small number of degrees of freedom. There are many methods that aim at the computation of the coarse component without resolving the full details of the solution. Our proposed method falls into the framework of interior penalty discontinuous Galerkin method, which is proved to be an effective and accurate class of methods for numerical solutions of partial differential equations. A distinctive feature of our method is that the solution space contains two components, namely a coarse space that gives a polynomial approximation to the coarse component in the traditional way and a multiscale space which contains sub-grid structures of the solution and is essential to the computation of the coarse component. In addition, stability of the method is proved. The numerical results indicate that the method can accurately capture the coarse behavior of the solution for problems in highly heterogeneous media as well as boundary and internal layers for convection-dominated problems.
Prediction Modeling Of Resource Sharing Between Secondary School Agriculture Teachers And Science Departments
Authors: Dormody Thomas J.
Published: December 2012

No abstract available
AN EVALUATION OF A DISTANCE EDUCATION COURSE DESIGN FOR GENERAL SOILS
Authors: Murphy Tim H.
Published: December 2012

The purpose of this study was to evaluate a distance education course design with respect to both educational effectiveness and learner satisfaction. The findings support the large body of literature indicating that distance delivery, regardless of media or technology used is not by itself a contributing variable in student achievement (Russell, 1998). The course design developed for the delivery of this course over distance accomplished the primary objective of creating a location-neutral learning experience for the students. Students performed equally well regardless of location or method. Learners completing the course were satisfied with their experience overall. There was no significant difference in learner satisfaction found between the students collocated with the instructor and the distance learners. The literature supports a conclusion that student-student and student-instructor interaction is positively correlated with learner satisfaction (Fulford & Zhang, 1993; Garrison, 1990; Ritchie & Newby, 1989). This study clouds rather than clarifies that conclusion.
KENTUCKY 4-H AGENTS’ PERCEPTIONS OF THEIR LEVELS OF COMPETENCY AND FREQUENCY OF USE OF VOLUNTEER ADMINISTRATION FUNCTION
Authors: Culp Ken , Kohlhagen Bradley Scott
Published: December 2012

The purpose of this study was to determine how 4-H Youth Development Agents in Kentucky perceived their level of competence and the frequency of use in each of the four categories and 18 phases outlined in the GEMS Model of Volunteer Administration. The difference between the level of competence and the frequency of use yields a need score which provides a framework for determining which phases of volunteer administration should be emphasized in staff development to increase agents’ knowledge or performance. These phases include: (Generate) needs assessment, writing job (position) descriptions, identifying, recruiting, screening, selecting; (Educate) orienting, protecting, providing resources, teaching; (Mobilize) engaging, motivating, supervising; (Sustain) evaluating, recognizing, retaining, redirecting and disengaging. The three phases of greatest competency were found to be Providing Resources, Recognizing and Engaging. Conversely, agents reported Disengaging as their least competent phase. Respondents also indicated that they most frequently Provide Resources, Recognize and Engage volunteers. 4-H Agents also least frequently use the Disengaging phase. The Borich Model (1979) was utilized to calculate the need score for each phase where by (Competency - Use) * Competency = Needs Score. The five phases with the highest need scores included Providing Resources, Recognizing, Supervising, Recruiting and Engaging. The findings indicate that 4-H Agents’ perceived level of competency to be greatest for the Mobilize category, followed by Educate, Generate and Sustain. An identical rank was calculated for frequency of use. The Mobilize category was also found to be ranked the highest for the calculated need score, followed by Sustain, Educate and Generate.
GLOBAL PERSPECTIVES AND ATTITUDES TOWARD CULTURAL DIVERSITY AMONG SUMMER AGRICULTURE STUDENTS AT THE OHIO STATE UNIVERSITY
Authors: Zhai Lijuan , Scheer Scott D.
Published: December 2012

The purpose of this study was to measure the level of global perspective and attitude toward cultural diversity among summer agriculture students using established survey scales for these constructs. A survey instrument was completed by 145 agriculture students at The Ohio State University. Survey results indicated that, in general, students tended to have a moderate global perspective and a positive attitude toward cultural diversity. High correlation was also found between global perspectives and attitudes toward diversity. In comparison with male students, females were more likely to have a higher level of global perspective and a more positive attitude toward cultural diversity. Students who had more contact with international people also scored higher on the global perspective and cultural diversity scales. Recommendations, implications, and future study directions derived from the survey results were discussed.
MODERNIZING THE AGRICULTURAL EDUCATION CURRICULUM: AN ANALYSIS OF AGRICULTURAL EDUCATION TEACHERS’ ATTITUDES, KNOWLEDGE, AND UNDERSTANDING OF BIOTECHNOLOGY
Authors: Boone Harry N. , Gartin Stacy A. , Boone Deborah A. , Hughes Jason E.
Published: December 2012

In 1917, the Smith-Hughes Act encouraged the development of an agricultural education curriculum that spread innovative farming techniques throughout the nation. During the last half of the 20th century, however, many programs failed to keep pace with rapidly changing technologies. In a major study funded by the National Academy of Sciences (National Research Council, Board on Agriculture, Committee on Agricultural Education in Secondary Schools, 1988), much of the focus and content of many vocational agriculture programs was found to be outdated. The authors challenged the profession to broaden the relevance and scope of the agricultural education curriculum to better prepare students for the study of agriculture. One response to this challenge was to infuse more science and technology into the agricultural education curriculum. The purpose of this descriptive research study was to provide information on the attitudes and knowledge of biotechnology by agricultural education teachers in West Virginia. A major finding of the study was the agricultural education teachers possessed a positive attitude towards biotechnology, but lacked the resources and knowledge to incorporate the subject matter into their curriculum. Teachers perceive themselves with more knowledge on biotechnology topics traditionally associated with agriculture (animal reproduction, hybridization) and less knowledge on topics associated with other fields (environmental biotechnology, human genomics).
Aligning Kolb’s Experiential Learning Theory with a Comprehensive Agricultural Education Model
Authors: Baker Marshall A. , Robinson J. Shane , Kolb David A.
Published: December 2012

Experiential learning has been a foundational tenant of agricultural education since its inception. However, the theory of experiential education has received limited attention in the permanent agricultural education literature base. As such, this philosophical manuscript examined Kolb’s experiential learning process further, and considered the implications for experiential learning theory (ELT) in secondary agricultural education. Specifically, the researchers outlined Kolb’s ELT and conducted a telephone interview with Dr. David A. Kolb. Analysis of the interview indicated that experiential learning is a critical component of a comprehensive agricultural education model (i.e., three–circle model). It was explained that experiential learning builds meta–cognitive skills and can be goal–oriented and assessed. However, agricultural educators must be present and purposeful when providing experiences for students. Additionally, they must ask reflection questions (e.g., “What happened?” “Now what?” “So what?”) during each phase of ELT throughout the comprehensive agricultural education model (i.e., classroom and laboratory, Supervised Agricultural Experience [SAE], and FFA). Based on these conclusions, a Comprehensive Model for Secondary Agricultural Education was proposed to include the role of experiential learning more intentionally.
Supervised Agricultural Experience: An Examination of Student Knowledge and Participation
Authors: Lewis Lauren J. , Rayfield John , Moore Lori L.
Published: December 2012

The purpose of this study was to investigate student Supervised Agricultural Experience (SAE) knowledge and participation. This descriptive study was conducted in 120 randomly selected agricultural education programs throughout four purposively selected states representative of the National FFA regions. Students completed a questionnaire assessing knowledge of the five SAE categories. According to findings of this study, 46.1% of the students surveyed reported having a SAE program (n = 473). Students on average could only correctly categorize between three and four of the five SAE project scenarios and approximately one–third of the students surveyed in Indiana, Missouri, and Utah could categorize all five. Students appeared to be able to correctly identify the improvement, research and experimentation, and placement SAE categories more frequently. Those surveyed without a SAE program were either not familiar or somewhat familiar with the five SAE categories. The average number of classroom days spent on SAE instruction since enrolled in agricultural education courses varied from nine to 34 and half of the students in three of the states did not receive a grade for their SAE program or record book in agricultural education courses. Students surveyed did not believe they needed more classroom instruction from their teacher about SAEs.
Incorporating Learning Objects in a Curriculum Redesign to Meet Needs of Students with Specific Learning Disabilities in Illinois Agricultural Education Programs
Authors: Pense Seburn L. , Calvin Jennifer , Watson Dennis G. , Wakefield Dexter B.
Published: December 2012

A quasi-experimental pilot study of curriculum re-design using Learning Objects (LO) to instruct agricultural education students with Specific Learning Disabilities (SLD) was conducted in five high schools in the federally designated economically distressed area, the Illinois Delta Region. Six LOs were developed based on a unit of instruction in The Illinois Core Curriculum for Agriculture and designed in a manner appropriate to SLD students. Students were randomly assigned to treatment and control groups. Results from pre-posttests in this study found Learning Objects increased learning for both SLD and traditional students.
Multicultural Teaching Concerns: A Comparison Between Disciplines at the Secondary Pre–service Level
Authors: Vincent Stacy K. , Killingsworth Justin L. , Torres Robert M.
Published: December 2012

Cultural diversity in secondary and postsecondary agricultural education programs lags behind recent demographic shifts in the general U.S. population. An examination of the literature provides inquiries into the need for teaching of multicultural awareness and reducing the achievement gap between students of various cultures. This research sought to summarize current concern levels secondary pre–service teachers have toward teaching in a multicultural classroom. Multicultural Teaching Concern was calculated based upon the summation of four constructs: familial/group knowledge, strategies and techniques, cross–cultural competencies, and school bureaucracy. Results indicate sex, home residency, and academic major play a role in the overall concern displayed. Secondary agricultural education pre– service teachers are not as concerned as secondary pre–service teachers from other disciplines. Recommendations for the selected institution include the development of an agricultural education multicultural course; the implementation of cultural immersion projects for students within the major; and professional development in multiculturalism among teacher educators.
College Major Choice for Students of Color: Toward a Model of Recruitment for the Agricultural Education Profession
Authors: Vincent Stacy K. , Henry Anna L. , Anderson James C.
Published: December 2012

The purpose of this study was to gain a deeper understanding of the reasons students, identifying as non– White, made the decision to pursue a career in agricultural education. This phenomenological study allowed the researchers to obtain the overall phenomenon of the thought processes that encompass decisions of students of color when selecting an academic major in college. Participants described having external and internal value orientations toward college major choice. When a value orientation increased toward a major prior to college, participants tended to be more apt to pursue a specific degree program. It was concluded that in addition to particular value orientations, distinct barriers to the decision–making process also inhibit the choice of agricultural education.
Secondary organic aerosol formation from gasoline passenger vehicle emissions investigated in a smog chamber
Authors: Nordin E. Z. , Eriksson A. C. , Roldin P. , Nilsson P. T. , Carlsson J. E. , Kajos M. K. , Hellén H. , Wittbom C. , Rissler J. , Löndahl J. , Swietlicki E. , Svenningsson B. , Bohgard M. , Kulmala M. , Hallquist M. , Pagels J.
Published: December 2012

Abstract. Gasoline vehicles have elevated emissions of volatile organic compounds during cold starts and idling and have recently been pointed out as potentially the main source of anthropogenic secondary organic aerosol (SOA) in megacities. However, there is a lack of laboratory studies to systematically investigate SOA formation in real-world exhaust. In this study, SOA formation from pure aromatic precursors, idling and cold start gasoline exhaust from one Euro II, one Euro III and one Euro IV passenger vehicles were investigated using photo-oxidation experiments in a 6 m3 smog chamber. The experiments were carried out at atmospherically relevant organic aerosol mass concentrations. The characterization methods included a high resolution aerosol mass spectrometer and a proton transfer mass spectrometer. It was found that gasoline exhaust readily forms SOA with a signature aerosol mass spectrum similar to the oxidized organic aerosol that commonly dominates the organic aerosol mass spectra downwind urban areas. After 4 h aging the formed SOA was 1–2 orders of magnitude higher than the Primary OA emissions. The SOA mass spectrum from a relevant mixture of traditional light aromatic precursors gave f43 (mass fraction at m/z = 4 3) approximately two times higher than to the gasoline SOA. However O : C and H : C ratios were similar for the two cases. Classical C6–C9 light aromatic precursors were responsible for up to 60% of the formed SOA, which is significantly higher than for diesel exhaust. Important candidates for additional precursors are higher order aromatic compounds such as C10, C11 light aromatics, naphthalene and methyl-naphthalenes.
Statistical bias correction of global climate projections – consequences for large scale modeling of flood flows
Authors: Eisner S. , Voss F. , Kynast E.
Published: December 2012

Abstract. General circulation models (GCMs) project an increasing frequency and intensity of heavy rainfall events due to global climate change. This rather holds true for regions that are even expected to experience an overall decrease in average annual precipitation. Consequently, this may be attended by an increasing frequency and magnitude of flood events. However, time series of GCMs show a bias in simulating 20th century precipitation and temperature fields and, therefore, cannot directly be used to force hydrological models in order to assess the impact of the projected climate change on certain components of the hydrological cycle. For a posteriori correction, the so-called delta change approach is widely-used which adds the 30-year monthly differences for temperature or ratios for precipitation of the GCM data to each month of a historic climate data set. As the variability of the climate variables in the scenario period is not transferred, this approach is especially questionable if discharge extremes are to be analyzed. In order to preserve the variability given by the GCM, methods of statistical bias correction are applied. This study aims to investigate the impact of two methods of bias correction, the delta change approach and a statistical bias correction, on the large scale modeling of flood discharges, using the example of 25 macroscale catchments in Europe. The discharge simulation is carried out with the global integrated model WaterGAP3 (Water – Global Assessment and Prognosis). Results show that the two bias correction methods lead to distinctively different trends in future flood flows.
A weather dependent approach to estimate the annual course of vegetation parameters for water balance simulations on the meso- and macroscale
Authors: Förster K. , Gelleszun M. , Meon G.
Published: December 2012

Abstract. In order to simulate long-term water balances hydrologic models have to be parameterized for several types of vegetation. Furthermore, a seasonal dependence of vegetation parameters has to be accomplished for a successful application. Many approaches neglect inter-annual variability and shifts due to climate change. In this paper a more comprehensive approach from literature was evaluated and applied to long-term water balance simulations, which incorporates temperature, humidity and maximum bright sunshine hours per day to calculate a growing season index (GSI). A validation of this threshold-related approach is carried out by comparisons with normalized difference vegetation index (NDVI) data and observations from the phenological network in the state of Lower Saxony. The annual courses of GSI and NDVI show a good agreement for numerous sites. A comparison with long-term observations of leaf onset and offset taken from the phenological network also revealed a good model performance. The observed trends indicating a shift toward an earlier leaf onset of 3 days per decade in the lowlands were reproduced very well. The GSI approach was implemented in the hydrologic model Panta Rhei. For the common vegetation parameters like leaf area index, vegetated fraction, albedo and the vegetation height a minimum value and a maximum value were defined for each land surface class. These parameters were scaled with the computed GSI for every time step to obtain a seasonal course for each parameter. Two simulations were carried out each for the current climate and for future climate scenarios. The first run was parameterized with a static annual course of vegetation parameters. The second run incorporates the new GSI approach. For the current climate both models produced comparable results regarding the water balance. Although there are no significant changes in modeled mean annual evapotranspiration and runoff depth in climate change scenarios, mean monthly values of these water balance components are shifted toward a lower runoff in spring and higher values during the winter months.
Bed-load transport modelling by coupling an empirical routing scheme and a hydrological-1-D-hydrodynamic model – case study application for a large alpine valley
Authors: Gems B. , Achleitner S. , Plörer M. , Schöberl F. , Huttenlau M. , Aufleger M.
Published: December 2012

Abstract. Sediment transport in mountain rivers and torrents is a substantial process within the assessment of flood related hazard potential and vulnerability in alpine catchments. Focusing on fluvial transport processes, river bed erosion and deposition considerably affects the extent of inundation. The present work deals with scenario-specific bed-load transport modelling in a large alpine valley in the Austrian Alps. A routing scheme founding on empirical equations for the calculation of transport capacities, incipient motion conditions and drag forces is set up and applied to the case study area for two historic flood events. The required hydraulic data result from a distributed hydrological-1-D-hydraulic model. Hydraulics and bed-load transport are simulated sequentially providing a technically well-founded and feasible methodology for the estimation of bed-load transport rates during flood events.
Potential climate change impacts on the water balance of subcatchments of the River Spree, Germany
Authors: Pohle I. , Koch H. , Grünewald U.
Published: December 2012

Abstract. Lusatia is considered one of the driest regions of Germany. The climatic water balance is negative even under current climate conditions. Due to global climate change, increased temperatures and a shift of precipitation from summer to winter are expected. Therefore, it is of major interest whether the excess water in winter can be stored and to which extent it is used up on increasing evapotranspiration. Thus, this study focuses on estimating potential climate change impacts on the water balance of two subcatchments of the River Spree using the Soil and Water Integrated Model (SWIM). Climate input was taken from 100 realisations each of two scenarios of the STatistical Analogue Resampling scheme STAR assuming a further temperature increase of 0 K (scenario A) and 2 K by the year 2055 (scenario B) respectively. Resulting from increased temperatures and a shift in precipitation from summer to winter actual evapotranspiration is supposed to increase in winter and early spring, but to decrease in later spring and early summer. This is less pronounced for scenario A than for scenario B. Consequently, also the decrease in discharge and groundwater recharge in late spring is lower for scenario A than for scenario B. The highest differences of runoff generation and groundwater recharge between the two scenarios but also the highest ranges within the scenarios occur in summer and early autumn. It is planned to estimate potential climate change for the catchments of Spree, Schwarze Elster and Lusatian Neisse.
SWAT model calibration of a grid-based setup
Authors: Rathjens H. , Oppelt N.
Published: December 2012

Abstract. The eco-hydrological model SWAT (Soil and Water Assessment Tool) is a useful tool to simulate the effects of catchment processes and water management practices on the water cycle. For each catchment some model parameters (e.g. ground water delay time, ground water level) remain constant and therefore are used as constant values; other parameters such as soil types or land use are spatially variable and thus have to be spatially discretized. SWAT setup interfaces process input data to fit the data format requirements and to discretize the spatial characteristics of the catchment area. The primarily used configuration is the sub-watershed discretization scheme. This spatial setup method, however, results in a loss of spatial information which can be problematic for SWAT applications that require a spatially detailed description of the catchment area. At present no SWAT interface is available which provides the management of input and output data based on grid cells. To fill this gap, the authors developed a grid-based model interface. To perform hydrological studies, the SWAT user first calibrates the model to fit to the environmental and hydrological conditions of the catchment. Compared to the sub-watershed approach, the grid-based setup significantly increases model computation time and hence aggravates calibration according to established calibration guidelines. This paper describes how a conventional set of sub-watershed SWAT parameters can be used to calibrate the corresponding grid-based model. The procedure was evaluated in a sub-catchment of the River Elbe (Northern Germany). The simulation of daily discharge resulted in Nash-Sutcliffe efficiencies ranging from 0.76 to 0.78 and from 0.61 to 0.65 for the calibration and validation period respectively; thus model performance is satisfactory. The sub-watershed and grid configuration simulate comparable discharges at the catchment outlet (R2 = 0.99). Nevertheless, the major advantage of the grid-based set-up is an enhanced spatial description of landscape units inducing a more realistic spatial distribution of model output parameters.
Modeling of water balance response to an extreme future scenario in the Ötztal catchment, Austria
Authors: Tecklenburg C. , Francke T. , Kormann C. , Bronstert A.
Published: December 2012

Abstract. The aim of the study was to investigate the impact of climate change on the water balance of the Ötztaler Ache catchment in Tyrol, Austria. For this purpose the conceptual hydrological model HBV-D REG was applied. First, the model was calibrated and validated using current observed climate and discharge data. Second, the calibrated model was applied with reanalysis data. Third, downscaled climate scenarios from 2010 to 2099 served as input data to the HBV-D REG. Thereby two extreme land cover scenarios were considered: for water balance modeling a constant glacier coverage from today and additionally for runoff simulations a complete loss of glaciered area. The downscaled climate data were generated with the expanded downscaling method. Scenario simulations indicated an increase in annual areal temperature by 3.4 °C and a slight decrease in annual areal precipitation by 89 mm in the next one hundred years. According to the hydrological modeling, these climate changes caused an increase in evapotranspiration and a decrease in snow coverage. Furthermore model simulations showed an increase in winter and spring runoff, whereas summer runoff was highly sensitive to glacier coverage and decreased with complete loss of glacier coverage.