WorldWideScience

Sample records for bulldozers

  1. Bulldozing of granular material

    CERN Document Server

    Sauret, A; Caulfield, C P; McElwaine, J N

    2014-01-01

    We investigate the bulldozing motion of a granular sandpile driven forwards by a vertical plate. The problem is set up in the laboratory by emplacing the pile on a table rotating underneath a stationary plate; the continual circulation of the bulldozed material allows the dynamics to be explored over relatively long times, and the variation of the velocity with radius permits one to explore the dependence on bulldozing speed within a single experiment. We measure the time-dependent surface shape of the dune for a range of rotation rates, initial volumes and radial positions, for four granular materials, ranging from glass spheres to irregularly shaped sand. The evolution of the dune can be separated into two phases: a rapid initial adjustment to a state of quasi-steady avalanching perpendicular to the blade, followed by a much slower phase of lateral spreading and radial migration. The quasi-steady avalanching sets up a well-defined perpendicular profile with a nearly constant slope. This profile can be scale...

  2. A Computational Model of Soil Adhesion and Resistance for a Non-smooth Bulldozing Plate

    Institute of Scientific and Technical Information of China (English)

    Shi Wei-ping; Ren Lu-quan; Tian Li-mei

    2005-01-01

    Adhesive forces exist between soil and the surfaces of soil-engaging components; they increase working resistance and energy consumption. This paper tries to find an approach to reduce the adhesion and resistance of bulldozing plate. A simplified mechanical model of adhesion and resistance between soil and a non-smooth bulldozing plate is proposed. The interaction force between moist soil and a non-smooth bulldozing plate is analyzed. The pressure and friction distribution on the bulldozing plate are computed, and the anti-adhesive effect of a corrugated bulldozing plate is simulated numerically.Numerical results show that the wavy bulldozing plate achieves an effective drag reduction in moist soil. The optimal wavy shape of the corrugated bulldozing plate with the minimal resistance is designed. The basic principle of reducing soil adhesion of the non-smooth surface is discovered.

  3. Impact of Bulldozer's Engine Load Factor on Fuel Consumption, CO2 Emission and Cost

    Directory of Open Access Journals (Sweden)

    V. Kecojevic

    2011-01-01

    Full Text Available Problem statement: Bulldozers consume a large amount of diesel fuel and consequently produce a significant quantity of CO2. Environmental and economic cost issues related to fuel consumption and CO2 emission represent a substantial challenge to the mining industry. Approach: Impact of engine load conditions on fuel consumption and the subsequent CO2 emission and cost was analyzed for Caterpillar bulldozers. Results were compared with the data on bulldozers' fuel consumption from an operating coal surface mine in the United States. Results: There is a strong linear correlation among power, fuel consumption and engine load factor. Reduction in load factor by 15% may significantly reduce the fuel consumption and the CO2 emission. Conclusion/Recommendation: Application of appropriate bulldozer's load factor may help mine operators manage fuel consumption, cost and environmental burden.

  4. Design of Stress-Strain Measuring System for Bulldozing Plate Based on Virtual Instrument Technology

    International Nuclear Information System (INIS)

    Soil is a kind of discrete, multiphase compound that is composed of soil particles, liquid and air. When soil is disturbed by bulldozing plate, the mechanical behavior of the soil will become very complex. Based on the law of action and reaction, the dynamic mechanical behavior of disturbed soil was indirectly analyzed by measuring and studying the forces on the bulldozing plate by soil currently, so a stress-strain virtual measuring system for bulldozing plate, which was designed by the graphical programming language DASYLab, was used to measure the horizontal force Fz acting on the bulldozing plate. In addition, during the course of design, the experimental complexities and the interferential factors influencing on signal logging were analyzed when bulldozing plate worked, so the anti-jamming methods of hardware and software technology were adopted correlatively. In the end, the horizontal force Fz was analyzed with Error Theory, the result shown that the quantificational analysis of Fz were identical to the qualitative results of soil well, and the error of the whole test system is under 5 percent, so the tress-strain virtual measuring system was stable and credible

  5. ALGORITHM OF DETERMINATION OF POWER AND ENERGY INDEXES OF SCREW INTENSIFIER ON THE BULLDOZER WORKING EQUIPMENT AT TRENCH REFILLINGS

    Directory of Open Access Journals (Sweden)

    KROL R. N.

    2016-03-01

    Full Text Available Raising of problem. A bulldozer work at trench refilings is conducted by cyclic, machine shuttle motions that increases a right-of-way; increasing of time charges, fuel and labour by the side of the continuous refilling method. Besides the indicated defects gets worse also the quality of the trench refilling: the uneven soil output into a trench with large portions results the damages of pipes isolation and emptinesses formation, in consequence  settling and washing of soil. A bulldozer with the screw intensifier (SI, is deprived lacks of an odinary bulldozer  moving along a trench, it moves the loose soil that does not fall on a pipeline, but rolles on it. Thus the circuitous speed of a cutting edge of SI exceeds the speed of the base machine moving that provides the strong soil treatment (before dispersion before output into a trench. Purpose. The algorithm development of the rotational moment determination on the SI driveshaft, the consumable energy, the energy intensity and the working process productivity of the reverse trench refillings depending on physical and mechanical properties of soil, geometrical parameters of SI and bulldozer optimal speed. Conclusion. The developed algorithm allows to define that at the fixed value of the rotational speed the rotational moment and indicated efficiency of SI at the optimum speed increasing of the base machine change on a linear law; the optimum speed change of the base machine practically does not influence on the energy intensity at the considered change of the rotational speed .

  6. Ripper Design of Large-size Bulldozers%大型推土机松土器的设计

    Institute of Scientific and Technical Information of China (English)

    张明月; 侯文军

    2012-01-01

    针对大型推土机松土器工作的特点,介绍并分析了大型推土机松土器的合理结构,提出了松土器的设计思路及计算方法.%There are two types of basic structure in parallelogram ripper to the tractor (bulldozer) that one of them is in a fixed pitch of ripping angle, and the other is in variable pitch. The variable one is featured in applicability as an attachment to large sized bulldozer. The text further introduces and analyzes concepts and structural selections, plus how to compute the main data.

  7. Prolonged exposure and virtual reality-enhanced imaginal exposure for PTSD following a terrorist bulldozer attack: a case study.

    Science.gov (United States)

    Freedman, Sara A; Hoffman, Hunter G; Garcia-Palacios, Azucena; Tamar Weiss, Patrice L; Avitzour, Sara; Josman, Naomi

    2010-02-01

    In this case study, virtual reality was used to augment imaginal exposure in a protocol based on prolonged exposure. A 29-year-old male patient developed posttraumatic stress disorder after surviving a deadly terrorist bulldozer attack on two civilian buses and several cars in Jerusalem; the traumas witnessed by the survivor included a decapitation. The crowded bus in which the patient was riding was pushed over onto its side by the terrorist, injuring, trapping, and terrifying the passengers and causing gasoline to leak. Guided by his therapist, the patient entered an immersive computer-generated virtual world to go "back" to the scene of the traumatic event to help him gain access to his memories of the event, process and reduce the intensity of the emotions (fear/anger) associated with his pathological memories, and change unhealthy thought patterns. Traumatic memories of childhood abuse and traumatic memories of the bulldozer terrorist attack were treated using imaginal exposure while the patient was in the virtual environment BusWorld. The patient showed large posttreatment reductions in PTSD symptoms, and his Clinician-Administered PTSD Scale (CAPS) scores dropped from 79 pretreatment to zero immediately posttreatment, and CAPS was still at zero 6 months later. Although case studies are inconclusive by nature, these encouraging preliminary results suggest that further exploration of the use of virtual reality during modified prolonged exposure for PTSD is warranted. As terrorist attacks increase in frequency and severity worldwide, research is needed on how to minimize the psychological consequences of terrorism.

  8. 履带式推土机的维护与保养%Care and Maintenance of the Bulldozer

    Institute of Scientific and Technical Information of China (English)

    任洪涛

    2012-01-01

    With the extension of service time of track-type tractors, there will be a variety of faults. If faults can not be solved timely, it will affect the use of crawler tractors. Therefore, the care and maintenance of crawler bulldozer is particularly important. In this paper, how to effectively strengthen the care and maintenance of the track-type tractors is in-depth discussed and put forward the suggestions and opinions.%随着履带式推土机使用时间的延长,会出现多种故障,故障如果不能及时解决,那么会影响到履带式推土机的使用。因此,履带式推土机的维护与保养就显得尤为重要。本文就如何有效加强履带式推土机的维护与保养进行了深入的探讨,提出了建议和看法。

  9. Bulldozing Biodiversity: The Economics of Optimal Extinction

    OpenAIRE

    Clive L Spash

    2015-01-01

    Many conservationists have become enamoured with mainstream economic concepts and approaches, described as pragmatic replacements for appeals to ethics and direct regulation. Trading biodiversity using offsets is part of the resulting push for market governance that is promoted as a more efficient means of Nature conservation. In critically evaluationg this position I start by explaining the assumptions behind biodiversity and ecosystem valuation and how economic logic legitimi...

  10. The bulldozer herbivore: how animals benefit from elephant modifying an African savanna

    NARCIS (Netherlands)

    Kohi, E.

    2013-01-01

    Herbivore-vegetation interactions are important structuring forces in savanna that modify the availability and quality of forage resources. Elephant for example, are known for their ability to change the vegetation structure through toppling trees, uprooting, snapping, debarking and breaking branche

  11. OLD MAN AND BULLDOZER, OR TWO GREAT SUBVERTER OF THE XX CENTURY IN RUSSIA IN LIFE AND IN ACADEMIC LITERATURE

    Directory of Open Access Journals (Sweden)

    V. G. PETROVICH

    2016-01-01

    Full Text Available The article seeks to uncover the milestones of the modern period in history of our country through the figure of the first President of the Russian Federation B.N. Yeltsin. Made more than a century of insight into history and a comparative analysis of the life and work of two of the most controversial figures in Russian history of the XX century – V.I. Ulyanov (Lenin and B.N. Yeltsin. Clarified the reasons for both historical characters to fight with the existing system of power. Tracked key milestones of this struggle. On the basis of extensive historical material is characterized by the contribution of each of them in the history of Russia are historical Parallels in the role of B.N. Yeltsin and V.I. Ulyanov (Lenin as destroyers existed before them political order and economic system of the state. In the spirit of the requirements of the historical and cultural standard are analyzed literary sources on the contribution of V.I. Ulyanov (Lenin and B.N. Yeltsin in Russia's development. Alternative options considered the history of modern Russia, based on conflicting character traits B.N. Yeltsin. Analyzed several national history textbooks used in schools across the country in the early XXI century, the examples of the lighting considered in the paper problems in history textbooks, admitted to Russian schools in 2016 and the respective historical-cultural standard. Provides an overview of opinions about the identity of B.N. Yeltsin expressed his contemporaries and associates. Data from sociological studies reflecting the opinion of Russians about these historical figures. The conclusion reveals the more tolerant attitude of Russians to the figure of V.I. Ulyanov (Lenin compared to B.N. Yeltsin.

  12. 推土机底盘支架螺纹联接改造方法%Upgrading of screw connection of bulldozer's chassis supporting

    Institute of Scientific and Technical Information of China (English)

    方颜空

    2006-01-01

    潜孔钻和推土机是矿山主要采矿设备,检修上述设备经常遇到行走部分无法恢复诸多问题,尤为突出的是支重轮座子的联接因长期在复杂环境中使用出现锈蚀、松旷等无法修复的难题,本方法着重论述如何有效恢复行走部分支重轮座子的联接问题,并进行了方案的可行性论证,提出了相应的修复方案.以便指导矿山生产.

  13. T140型系列推土机后置悬挂铧犁装置%Rear-mounted Plough Attachment on Series Model T140 Bulldozer

    Institute of Scientific and Technical Information of China (English)

    韩毓文; 王步云

    2003-01-01

    @@ 推土机后置铧犁装置是为满足市场需求而开发设计的一种新的工作装置,该装置的开发为推土机多功能作业开辟了新的思路.这种装置在国内较为少见,但在国外早有开发,如德国利勃海尔(Lieb-herr)公司PR732静液压履带式推土机就带有此类装置,即在后部设置悬挂犁用于农业作业.

  14. 拆迁普店街:二十世纪末中国都市小说中摧毁和复兴主题的含混 (Bulldozing Pudian Street: Destruction or Renewal? Ambiguities in Big City Novels in Late 20th Century Chinese Literature

    Directory of Open Access Journals (Sweden)

    Xia Li

    2007-01-01

    Full Text Available There is little doubt that the most cogent literary representation of the experience of modernity has been realised in big city fiction and cinematographic masterpieces such as Fritz Lang's Metropolis (1926. Despite the formal and aesthetic incompatability of early twentieth century (predominantly Western works of this literary genre and more recent ones, East and West, the underlying dialectic tension between progressive optimism and disorientation, existential up-rootedness, alienation and angst (Rilke's loss of soul as archetypal manifestation of mega-city reality and its social structure and organisation, constitutes a generic hallmark, regardless of time and place. Significantly, the relevance of this problem is reinforced, theoretically and practically, by the eminent scholar and architect Rem Koolhaas whose reflections have China as a principal reference point of the global "out-of-control process of modernisation". This paper focuses on the literary representation of the complexity and universality of the problem and the social implications of the blurred and ambiguous vision of urban reality with particular reference to contemporary Chinese literature.

  15. DESTRUCTION CONDITIONS WHEN DITTING HOMOGENEOUS GROUND AND GROUND WITH INCLUSION

    OpenAIRE

    Nichke, V.; Demishkan, V.

    2005-01-01

    On the base of analyses strained state the strong a ground with inclusion, and take into account a bigger traction effort of a modern bulldozers, was shoved as destroyed a rocks ground, a ground with inclusion, homogeneous a ground.

  16. Environmental Impacts of Forest Road Construction on Mountainous Terrain

    Directory of Open Access Journals (Sweden)

    Erhan Caliskan

    2013-03-01

    Full Text Available Forest roads are the base infrastructure foundation of forestry operations. These roads entail a complex engineering effort because they can cause substantial environmental damage to forests and include a high-cost construction. This study was carried out in four sample sites of Giresun, Trabzon(2 and Artvin Forest Directorate, which is in the Black Sea region of Turkey. The areas have both steep terrain (30-50% gradient and very steep terrain (51-80% gradient. Bulldozers and hydraulic excavators were determined to be the main machines for forest road construction, causing environmental damage and cross sections in mountainous areas.As a result of this study, the percent damage to forests was determined as follows: on steep terrain, 21% of trees were damaged by excavators and 33% of trees were damaged by bulldozers during forest road construction, and on very steep terrain, 27% of trees were damaged by excavators and 44% of trees were damaged by bulldozers during forest road construction. It was also determined that on steep terrain, when excavators were used, 12.23% less forest area was destroyed compared with when bulldozers were used and 16.13% less area was destroyed by excavators on very steep terrain. In order to reduce the environmental damage on the forest ecosystem, especially in steep terrains, hydraulic excavators should replace bulldozers in forest road construction activities.

  17. Dynamic Modeling and Control Strategy Optimization for a Hybrid Electric Tracked Vehicle

    Directory of Open Access Journals (Sweden)

    Hong Wang

    2015-01-01

    Full Text Available A new hybrid electric tracked bulldozer composed of an engine generator, two driving motors, and an ultracapacitor is put forward, which can provide high efficiencies and less fuel consumption comparing with traditional ones. This paper first presents the terramechanics of this hybrid electric tracked bulldozer. The driving dynamics for this tracked bulldozer is then analyzed. After that, based on analyzing the working characteristics of the engine, generator, and driving motors, the power train system model and control strategy optimization is established by using MATLAB/Simulink and OPTIMUS software. Simulation is performed under a representative working condition, and the results demonstrate that fuel economy of the HETV can be significantly improved.

  18. New Product

    Institute of Scientific and Technical Information of China (English)

    铭瑄

    2012-01-01

    Double Coin Holdings Launch New OTR Tire REM-15 With the increase of the demand for large-scale bulldozer in American market, Double Coin Group Co., Ltd. developed the Double Coin REM-15 OTR tire. This product is applicable for large-scale loader and bulldozer. The most remarkable characteristic is that it has good energy-saving performance and durability with low operating cost while the performances of tires aren't lowered. The new REM-15 is currently offered in the 17.5R25 size, which will be expanded to larger sizes in the future.

  19. Diesel Engine Technician

    Science.gov (United States)

    Tech Directions, 2010

    2010-01-01

    Diesel engine technicians maintain and repair the engines that power transportation equipment such as heavy trucks, trains, buses, and locomotives. Some technicians work mainly on farm machines, ships, compressors, and pumps. Others work mostly on construction equipment such as cranes, power shovels, bulldozers, and paving machines. This article…

  20. 77 FR 42509 - Notice of Inventory Completion: The University of Montana, Missoula, MT

    Science.gov (United States)

    2012-07-19

    ... removed from within the city limits of Missoula, MT. This notice is published as part of the National Park..., represented only by several vertebrae, was also elderly, but exact age and sex cannot be determined. No known... bulldozer from an historical Indian burial in the city of Missoula, MT. This burial site location is...

  1. The Gift of Magi(extract)

    Institute of Scientific and Technical Information of China (English)

    O.Henry

    2008-01-01

    One dollar and eighty-seven cents.That was all. And sixty cents of it was in pennies.①Pennies saved one and two at a time by bulldozing the grocer and the vegetable man and the butcher until one’s cheeks burned with the silent imputation of parsimony(2)that

  2. A Mean Wink at Authenticity: Chinese Images in Disney's "Mulan."

    Science.gov (United States)

    Mo, Weimin; Shen, Wenju

    2000-01-01

    Offers a critique from two Chinese educators with regard to the historical, cultural, linguistic, and artistic authenticity of Disney's animated film "Mulan." Argues that the filmmakers robbed the original story of its soul and "ran over Chinese culture with the Disney bulldozer," imposing mainstream cultural beliefs and values. (SR)

  3. SHANTUI Fushun base:Go ahead under adverse market%山推抚起 在市场逆流中奋进——对话山推首席设计师叶文彪博士

    Institute of Scientific and Technical Information of China (English)

    贾泽辉

    2012-01-01

    As we all known,SHANTUI bulldozer sales leading global. With 32 years history of the new SHANTUI,today in other fields has also made a figure. As the most outstanding bulldozer manufacturers in domestic construction machinery industry,SHANTUI develops diversified products in accordance with the "internationalized vision diversified SHANTUI" strategic subject.At present SHANTUI has become complete engineering machinery manufacturers containing with combination excavator and hauler,road machinery,concrete machinery,aerial work machinery,piling machinery,industrial trucks,the core components of the product category. As the diversity of the new engine of SHANTUI, Fushun Industrial Park of SHANTUI play an important role in the production and business are advance steadily.

  4. More Durable Tracks for Heavy Vehicles

    Science.gov (United States)

    Collins, Earl R., Jr.

    1987-01-01

    Tie bars instead of threaded fasteners make track throwing less likely. Proposed undercarriage for tank or bulldozer has flanged edges to prevent rocks and other road debris from getting caught in track drive and damaging or casting off track. Improved track has no threaded fasteners to be loosened by road shock and vibration. Continuous chain of floating guide bars articulated at web junctions. Pins replace bolted connections. Guide bars and flanges on vehicle keep out stones.

  5. Differential characteristics of photochemical acclimation to cold in two contrasting sweet sorghum hybrids.

    Science.gov (United States)

    Zegada-Lizarazu, Walter; Fernando Luna, Dario; Monti, Andrea

    2016-08-01

    Sweet sorghum has a photosynthetic system which is highly sensitive to cold stress and hence strongly limits its development in temperate environments; therefore, the identification of key exploitable cold tolerance traits is imperative. From a preliminary field trial, two dissimilar sweet sorghum hybrids (ICSSH31 and Bulldozer), in terms of early vigor and productivity, were selected for a controlled-environment trial aiming at identifying useful traits related to acclimation mechanisms to cold stress. The higher cold tolerance of Bulldozer was partially related to a more efficient photochemical regulation mechanism of the incoming light energy: the higher tolerance of photosystem II (PSII) to photo-inactivation was because of a more effective dissipation capacity of the excess of energy and to a more balanced diversion of the absorbed energy into alternative energy sinks. ICSSH31 increased the dissipation and accumulation of a large amount of xanthophylls, as in Bulldozer, but, at the same time, inactivated the oxygen evolving complex and the re-synthesis of chlorophyll (Chl) a and b, thus, leading to an overproduction of CO2 fixation enzymes after re-warming. In summary, in Bulldozer, the acclimation adjustments of the photosynthetic apparatus occurred through an efficient control of energy transfer toward the reaction centers, and this likely allowed a more successful seedling establishment; ICSSH31, conversely, exhibited a fast re-synthesis of Chl pigments, which appears to divert photosynthates from dry matter accumulation. Such broad acclimation traits may constitute a source for selecting higher genetic gain traits relevant for enlarging the growing season of promising biomass sorghum ideotypes in temperate climates. PMID:26867791

  6. Soil loss and displacement by heavy equipment in forest road subgrading projects

    Institute of Scientific and Technical Information of China (English)

    Aidin PARSAKHOO; Seyed Ataollah HOSSEINI; Majid LOTFALIAN; Hamid JALILVAND

    2009-01-01

    Forest soil is an important component of the natural environment, and is a primary medium for many biological activities. In this study, soil loss and displacement by excavator and bulldozer (heavy equipments) were measured on cut and fills slopes of forest roads located in Mazandaran province,Iran. The volumes of soil losses were estimated by prismoidal analyses of cut and fill slopes deformation between two time treatments (under subgrading and two years later) in slope classes of 30-50% and 50-70%. Weights of soil losses were calculated by multiplying the volumes of soil losses (cm3) to the general bulk density (1.3g/cm3). Soil displaced area by heavy equipment was evaluated according to earth working width. Results indicated that heavy equipment has significant effect on deformation of cut slope gradient and fill slope length (p<0.0001). During the two-year period, the cut (p<0.0002) and fill (p<0.0001) slope gradients were significantly deformed in different slope classes.The average soil loss by excavator and bulldozer were 160.35 t/ha.yr and 429.09 t/ha.yr, respectively.Moreover, the soil displaced area during the subgrading process by bulldozer was greater than excavator in both two slope classes (p<0.05). Soil loss and displacement in forest roads can be reduced by applying powerful excavators in subgrading project, especially in steep terrains.

  7. Sliding resistance of plates with bionic bumpy surface against soil

    Institute of Scientific and Technical Information of China (English)

    LI Jian-qiao; SUN Jiu-rong; REN Lu-quan; CHEN Bing-cong

    2004-01-01

    The non-smooth surface morphology of dung beetle, Copris ochus, was analyzed. The bulldozing plates with bionic geometric non-smooth or the chemical uneven surface were designed for the soil sliding test based on the simulation of the bumpy surface of the dung beetle. Special black metals-with different contents of alloys of manganese, silicon, chromium,copper and rare earth-were developed for making geometric non-smooth and chemical uneven surfaces by means of surface welding at the surfaces of a middle carbon steel plate. Four metals, with different surface properties including hardness and water contact angle were used to make the bulldozing plates for measuring the soil sliding resistance. Test results of soil sliding resistance indicate that all the geometric non-smooth plates and the chemical uneven plates reducing soil friction.Considering the materials and surface morphology, the bionic plate can reduce the soil sliding resistance from 18.1% up to 42.2%, compared to the traditional smooth bulldozing plate made from middle carbon steel. The test results also show that the smaller the normal load, the greater effect on resistance reduction by the bionic non-smooth surface plates.

  8. [Landscape pattern changes at village scale using high resolution satellite images: A case study in low-slope hilly area of Dali City, Northwestern Yunnan Province].

    Science.gov (United States)

    Zhao, Ming-yue; Peng, Jian; Liu, Yan-xu; Zhang, Tian

    2015-12-01

    Human activity is the main driving force of the change of land cover and landscape patterns. However, there are few studies focusing on the mechanism of human-induced change of land cover and landscape patterns at village scale. In this study, taking low-slope hilly area of Dali City, Northwestern Yunnan Province as a case study area, high resolution satellite images were introduced to find out the rules of land cover and landscape pattern changes, i.e. GeoEye-1 of 2009 and World- View-3 of 2014. The object-oriented and human-computer-interaction approaches were applied to interpret the images using ArcGIS 10.2 and ENVI 5.2. The results showed that, the main land cover types in the study area were forest land, paddy field and dry land in 2009, with forest, bulldozed unbuilt ground and paddy field in 2014, accounting for 82.8% and 70.9% of the total area, respectively. The land cover transition showed that, during 2009-2014, the main land cover change flows were from forest land, paddy field and dry land, to bulldozed unbuilt ground and construction land. Furthermore, the area of bulldozed but unbuilt land had increased to be 531.57 hm² in 2014, which mainly came from forest land (42.8%), dry land (21.7%), and paddy field (14.2%). Landscape pattern change was characterized as the increase of patch quantity and density, the decrease of mean patch size, the complication of patch shape, the fragmentation of landscape patches, and the diversification of landscape patterns.

  9. 液压机械传动在大功率履带拖拉机上的应用与分析%Applications of HMT on Large Crawler Tractors and its Construction Analysis

    Institute of Scientific and Technical Information of China (English)

    田全忠

    2001-01-01

    液压机械传动(HMT)是一种新型的无级变速装置。主要介绍了它的组成结构、基本原理以及国内外在大功率履带拖拉机、推土机上的应用与分析。%HMT (The hydraulic and mechanical transmission) is a new type stepless transmission. Its construction and primary principle are analysed. The application on large crawler tractors and bulldozers have been introduced.

  10. Defending Home

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ Television audiences around the country were shocked on November 21,2009, when national broadcaster China Central Television showed clips of two families violently fighting lawenforcement officials who were evicting them from their homes. The first incident being broadcast happened in June 2008, when Pan Rong and her husband stood on the roof of their four-story house to confront a demolition crew that consisted of police officers, firefighters and a bulldozer. Their family home stood in the way of a Shanghai Hongqiao Airport expansion project. Pan shouted into a loudspeaker,"If you don't have a court verdict, you are violating our property rights."

  11. Estimated radiation doses resulting if an exploratory borehole penetrates a pressurized brine reservoir assumed to exist below the WIPP repository horizon: a single hole scenario

    International Nuclear Information System (INIS)

    A radiation dose consequence analysis has been performed for a postulated scenario in which an exploratory gas or oil well-bore penetrates the repository and intercepts a brine reservoir in the Castile formation. The brine, corings and drilling mud are contained in a one acre holding pond on the surface. Upon the completion of drilling activities the dried holding pond area is reclaimed with a bulldozer to its original topographic conformation. The estimated radiation bone dose commitments to (1) a bulldozer operator, and (2) a member of a farm family 500 meters down wind are summarized for three penetration event times. The highest estimated 50 year bone dose commitment to an individual reclaiming the contaminated holding pond area was determined to be 590 mrem from the inhalation of CH-TRU wastes resuspended into the atmosphere at an event time of 100 years post-closure. A second dose model using a specific activity approach is developed in Appendix C for this same individual where an upper 50 year dose commitment of 450 mrem is calculated. Both of these derived estimates may be compared to the 5800 mrem to bone surfaces which may be expected from natural background radiation to an individual in the United States over a fifty year period

  12. Post-disturbance plant community dynamics following a rare natural-origin fire in a Tsuga canadensis forest.

    Directory of Open Access Journals (Sweden)

    Bryan D Murray

    Full Text Available Opportunities to directly study infrequent forest disturbance events often lead to valuable information about vegetation dynamics. In mesic temperate forests of North America, stand-replacing crown fire occurs infrequently, with a return interval of 2000-3000 years. Rare chance events, however, may have profound impacts on the developmental trajectories of forest ecosystems. For example, it has been postulated that stand-replacing fire may have been an important factor in the establishment of eastern hemlock (Tsuga canadensis stands in the northern Great Lakes region. Nevertheless, experimental evidence linking hemlock regeneration to non-anthropogenic fire is limited. To clarify this potential relationship, we monitored vegetation dynamics following a rare lightning-origin crown fire in a Wisconsin hemlock-hardwood forest. We also studied vegetation in bulldozer-created fire breaks and adjacent undisturbed forest. Our results indicate that hemlock establishment was rare in the burned area but moderately common in the scarified bulldozer lines compared to the reference area. Early-successional, non-arboreal species including Rubus spp., Vaccinium angustifolium, sedges (Carex spp., grasses, Epilobium ciliatum, and Pteridium aquilinium were the most abundant post-fire species. Collectively, our results suggest that competing vegetation and moisture stress resulting from drought may reduce the efficacy of scarification treatments as well as the usefulness of fire for preparing a suitable seedbed for hemlock. The increasing prevalence of growing-season drought suggests that silvicultural strategies based on historic disturbance regimes may need to be reevaluated for mesic species.

  13. Heavy construction equipment noise study using dosimetry and time-motion studies

    Science.gov (United States)

    Spencer, Ellsworth R.; Yantek, David S.

    2005-09-01

    Noise-induced hearing loss continues to afflict workers in many occupational settings despite longstanding recognition of the problems and well-known methods of prevention and regulations. Sound levels associated with heavy construction equipment range from 80 to 120 dB(A) and power tools commonly used in construction produce sound levels up to 115 dB(A). The focus of the research was to determine the noise exposures of heavy construction equipment operators while documenting the workers' tasks, (i.e., hauling, moving, and/or pushing construction material). Time-motion studies were performed at the construction sites and were used to correlate the noise dosage with the work performed by equipment operators. The cumulative dose for the operator was then plotted with references to work tasks, to identify the tasks that caused the greatest noise exposure. Three construction sites were examined and located in the western Pennsylvania and eastern Ohio areas. The types of construction equipment studied included asphalt pavers, backhoes, bulldozers, compaction equipment, excavators, haul trucks, telehandlers, and wheeled loaders. The results showed that bulldozer operators consistently had the highest noise exposures, ranging from a NIOSH REL (Recommended Exposure Limit) dose of 844% to 25836% and an OSHA PEL (Permissible Exposure Limit) dose of 139% to 1397%.

  14. Fuel breaks affect nonnative species abundance in Californian plant communities

    Science.gov (United States)

    Merriam, K.E.; Keeley, J.E.; Beyers, J.L.

    2006-01-01

    We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment programs throughout the United States to reduce the threat of wildland fire. Our study included 24 fuel breaks located across the State of California. We found that nonnative plant abundance was over 200% higher on fuel breaks than in adjacent wildland areas. Relative nonnative cover was greater on fuel breaks constructed by bulldozers (28%) than on fuel breaks constructed by other methods (7%). Canopy cover, litter cover, and duff depth also were significantly lower on fuel breaks constructed by bulldozers, and these fuel breaks had significantly more exposed bare ground than other types of fuel breaks. There was a significant decline in relative nonnative cover with increasing distance from the fuel break, particularly in areas that had experienced more numerous fires during the past 50 years, and in areas that had been grazed. These data suggest that fuel breaks could provide establishment sites for nonnative plants, and that nonnatives may invade surrounding areas, especially after disturbances such as fire or grazing. Fuel break construction and maintenance methods that leave some overstory canopy and minimize exposure of bare ground may be less likely to promote nonnative plants. ?? 2006 by the Ecological Society of America.

  15. Consideraciones sobre las máquinas de neumáticos y cadenas (Parte I

    Directory of Open Access Journals (Sweden)

    Chinchilla, M.

    1966-11-01

    Full Text Available The continued development of machinery takes place usually in a sustained and progressive manner. However, occasionally new possibilities emerge, which open up new fields and require entirely new techniques, both in the use, construction and design of the new equipment. A particular case is the adoption of wheels with pneumatic tyres on bulldozers, as a result of their use in loading units. The changes that have occurred in these last ten years have been so important that it may well be said that until recently the use of pneumatic tyres on bulldozers and loaders had not been clearly defined, in terms of their functions. At present the main characteristics that differentiate machines of the same type using tyres and those using caterpillars can be definitely enunciated. One of the main factors is that machinery using tyres must be limited to very specific tasks, whilst equipment using continuous tracks can carry out bulldozing and loading jobs under highly varied conditions.La evolución de la maquinaria se realiza normalmente de una forma continuada y progresiva. De vez en cuando aparecen, sin embargo, posibilidades nuevas que abren campos diferentes y que requieren técnicas distintas, tanto en el empleo como en la construcción y diseño de estos tipos de maquinaria. Uno de estos casos concretos, lo ha sido la aparición de las ruedas neumáticas en las máquinas topadoras, como consecuencia de su empleo en las unidades cargadoras. Los cambios sufridos en estos últimos diez años han sido tan grandes, que puede decirse que hasta hace muy poco el empleo de los neumáticos en las máquinas topadoras y cargadoras no ha quedado bien delimitado en cuanto a sus requerimientos y sus posibilidades. De todas formas, ya pueden enunciarse las principales características que diferencian las máquinas de cadenas y neumáticos, de la misma clase; una de estas características es la particularización que requieren las máquinas de neumáticos en su

  16. Demolitions of the Savannah River Site's concentrator and finishing facilities

    International Nuclear Information System (INIS)

    The Savannah River Site (SRS) has produced Special Nuclear Materials (SNMs) starting in the early 1950's to the mid 1970's for the Atomic Energy Commission (AEC) and from the mid 1970's to the present for the Department of Energy (DOE). In that time, over 1,000 facilities have been built in the sixteen operational areas of the eight hundred square kilometer site. Over the years, many of the facilities have been dispositioned by the DOE as inactive. In FY-03, DOE identified two hundred and forty-seven (inactive or soon to be inactive) facilities that required demolition. Demolition work was scheduled to start in FY-04 and be completed in the first quarter of FY-07. Two-hundred and thirty-nine of these facilities have been demolished employing Routine demolition techniques. This presentation reviews and discusses two of the eight Non-Routine demolitions Facilities, 420-D 'The Concentrator Facility', and 421-D 'The Finishing Facility'. Facilities 420-D and 421-D were toppled by attaching rigging from the structural steel building frame to bulldozers and toppling the facilities over. The greatest advantage of this method is that it employs equipment that is on hand at SRS, saving time on locating and leasing offsite equipment as well as operator training. In addition, although the toppled structure does not land in the original facilities footprint, it does land in a contained area that is easily barricaded to prevent access during the operation. There are several disadvantages. First, there must be adequate area for the structure to topple into. Also if the wire rope size required to topple the structure is larger than two in., the ropes become extremely difficult to work with. Lastly, the yield strength of steel members is guaranteed by the manufacturer as a minimum strength, so its ultimate strength is unknown. This requires extremely conservative specifications sizing the bulldozers and any rigging equipment employed. Two hundred and forty-seven facilities have

  17. Heavy impact-destructive pneumatic hammers

    Energy Technology Data Exchange (ETDEWEB)

    Georgiev, G.; Vasilev, V.; Dachev, L.; Kralev, I.; Gradishki, Kh.; Koev, S.

    1987-08-01

    Describes technical features of heavy impact-destructive pneumatic hammers, manufactured in the USSR, FRG, Japan, Belgium, France and the USA. The drawbacks and advantages of foreign pneumatic hammers were envaluated by Bulgarian specialists. Bulgarian mining and construction industries make little use of foreign heavy and pneumatic hammers. Units of the Soniet PN-1300 and PN-1700 were manufactured in 1978 by workshops of the Minstroi enterprise. The Probivna Technika laboratory developed an impact-destructive heavy pneumatic hammer - the BP-1801, which was followed by three further types - the LPT-520.1, LPT-520.2, and LPT-520.3, all of which may be attached to L.P.T. hydraulic excavators, bulldozers or loaders weighing more than 8 tons. A scheme of pneumatic hammer design is given and basic parameters are described. Hammers made in Bulgaria are of valveless construction, allowing for simplicity, mechanical effectiveness and reliability. Five prototypes were successfully tested in 1985. 2 refs.

  18. Sub-scour soil deformation and the development of ideas from field work in the last decade

    Energy Technology Data Exchange (ETDEWEB)

    Woodworth-Lynas, C.M.T. [PETRA International, Cupids, NF (Canada)

    1998-11-01

    The forces and deformation mechanisms experienced by different soils during ice scouring events are discussed. A series of modeling studies have been conducted at C-CORE for the past seven years to help in the design of offshore pipelines that must withstand scouring forces. The Pressure Ridge Ice Scour Experiments (PRISE) are a series of physical model studies conducted in a geotechnical centrifuge at accelerations of 75 to 200 g. They have helped in understanding scour induced failure mechanisms in a variety of different soil types and conditions. Another study, the Dynamics of Iceberg Grounding and Scouring (DIGS), has shown that horizontal bulldozing, although important, is not the only mechanism at work during ice/seabed interaction. 31 refs., 3 figs.

  19. The Challenge of Wireless Connectivity to Support Intelligent Mines

    DEFF Research Database (Denmark)

    Barbosa, Viviane S. B.; Garcia, Luis G. U.; Portela Lopes de Almeida, Erika;

    2016-01-01

    in terms of network planning, management and optimization. For example, the data rates required to support unmanned equipment, e.g. a teleoperated bulldozer, shift from a few kilobits/second to megabits/second due to live video feeds. This traffic volume is well beyond the capabilities of Professional...... for unmanned mine operations. Although voice and narrowband data radios have been used for years to support several types of mining activities, such as fleet management (dispatch) and telemetry, the use of automated equipment introduces a new set of connectivity requirements and poses a set of challenges...... Mobile Radio narrowband systems and mandates the deployment of broadband systems. Furthermore, the (data) traffic requirements of a mine also vary in time as the fleet expands. Additionally, wireless networks are planned according to the characteristics of the scenario in which they will be deployed...

  20. Automatic target classification of man-made objects in synthetic aperture radar images using Gabor wavelet and neural network

    Science.gov (United States)

    Vasuki, Perumal; Roomi, S. Mohamed Mansoor

    2013-01-01

    Processing of synthetic aperture radar (SAR) images has led to the development of automatic target classification approaches. These approaches help to classify individual and mass military ground vehicles. This work aims to develop an automatic target classification technique to classify military targets like truck/tank/armored car/cannon/bulldozer. The proposed method consists of three stages via preprocessing, feature extraction, and neural network (NN). The first stage removes speckle noise in a SAR image by the identified frost filter and enhances the image by histogram equalization. The second stage uses a Gabor wavelet to extract the image features. The third stage classifies the target by an NN classifier using image features. The proposed work performs better than its counterparts, like K-nearest neighbor (KNN). The proposed work performs better on databases like moving and stationary target acquisition and recognition against the earlier methods by KNN.

  1. Production and efficiency of large wildland fire suppression effort: A stochastic frontier analysis.

    Science.gov (United States)

    Katuwal, Hari; Calkin, David E; Hand, Michael S

    2016-01-15

    This study examines the production and efficiency of wildland fire suppression effort. We estimate the effectiveness of suppression resource inputs to produce controlled fire lines that contain large wildland fires using stochastic frontier analysis. Determinants of inefficiency are identified and the effects of these determinants on the daily production of controlled fire line are examined. Results indicate that the use of bulldozers and fire engines increase the production of controlled fire line, while firefighter crews do not tend to contribute to controlled fire line production. Production of controlled fire line is more efficient if it occurs along natural or built breaks, such as rivers and roads, and within areas previously burned by wildfires. However, results also indicate that productivity and efficiency of the controlled fire line are sensitive to weather, landscape and fire characteristics.

  2. Characterisation of carbonate rocks from near-surface cross-hole and reflection GPR investigations - A case study from southeast Zealand, Denmark

    DEFF Research Database (Denmark)

    Nielsen, Lars; Looms, Majken Caroline; Hansen, Thomas Mejer;

    Carbonates found in the near-surface of southeast Zealand, eastern Denmark, are analogous to deposits serving as groundwater and hydrocarbon reservoirs in the Danish region. The study site is located in the Boesdal limestone quarry. A 20 by 20 m area of the bottom of the quarry was levelled using...... a bulldozer, and a grid of 100 MHz and 250 Mhz reflection profiles were collected to facilitate geological interpretation of structures in the uppermost part of the subsurface. Secondly, four 15 m deep boreholes were drilled in a square geometry with side lengths of 5 m. Core material was recovered from...... to facilitate deeper imaging of the carbonates. The section studied with the cross-hole data is water-saturated. Simple 1D modelling of the cross-hole data indicates a strong drop in GPR velocity at 7 to 8 m depth. Different 2D inversion strategies are tested for fine scale resolution of the inter...

  3. Spreading granular material with a blade

    Science.gov (United States)

    Dressaire, Emilie; Singh, Vachitar; Grimaldi, Emma; Sauret, Alban

    2015-11-01

    The spreading of a complex fluid with a blade is encountered in applications that range from the bulldozing of granular material in construction projects to the coating of substrates with fluids in industrial applications. This spreading process is also present in everyday life, when we use a knife to turn a lump of peanut butter into a thin layer over our morning toast. In this study, we rely on granular media in a model experiment to describe the three-dimensional spreading of the material. Our experimental set-up allows tracking the spreading of a sandpile on a translating flat surface as the blade remains fixed. We characterize the spreading dynamics and the shape of the spread fluid layer when varying the tilt of the blade, its spacing with the surface and its speed. Our findings suggest that it is possible to tune the spreading parameters to optimize the coating.

  4. Enhancement factors for resuspended aerosol radioactivity: Effects of topsoil disturbance

    International Nuclear Information System (INIS)

    The enhancement factor for airborne radionuclides resuspended by wind is defined as the ratio of the activity density (Bq g-1) in the aerosol to the activity density in the underlying surface of contaminated soil. Enhancement factors are useful for assessment of worst-case exposure scenarios and transport conditions, and are one of the criteria for setting environmental standards for radioactivity in soil. This paper presents results of experimental studies where resuspension of 239Pu was measured when air concentrations were equilibrated to the soil surface. Enhancement factors were observed for several types of man-made disturbances (bulldozer-blading, soil raking, vacuum-cleaning) and natural disturbances (springtime thaw, soil-drying, wildfire). For some cases, enhancement factors are compared over range of geographical locations (Bikini Atoll, California, Nevada, and South Carolina). The particle-size distributions of aerosol activity are compared to particle-size distributions of the underlying soil

  5. Deformation Structures associated with the emplacement of high level intrusions: A study of Trachyte Mesa Intrusion, Henry Mountains, Utah

    Science.gov (United States)

    Wilson, P. I. R.; McCaffrey, K. J. W.; Jarvis, I.; Murphy, P.; Davidson, J. P.

    2012-04-01

    Most studies of sill and laccolith complexes have focused on the internal architecture and thermal effects of these intrusions, while few have looked in detail at host rock deformation structures associated with their emplacement. Various sill and laccolith emplacement mechanisms have been proposed (e.g. radial growth/ bulldozing, and two-stage growth), each with their own distinct deformation style. Compressional structures likely dominate during radial growth (bulldozing) emplacement, while extensional structures are more likely to form during two-stage growth emplacement. In this study we focus on deformation structures (faults, deformation bands and joints) associated with emplacement of Tertiary sills and laccolith intrusions in the Henry Mountains, Utah. Trachyte Mesa, the most distal satellite intrusion to the Mt. Hilliers intrusive centre, is an elongate (NE-SW) laccolith concordant with the Entrada sandstone it intrudes. The intrusion is comprised of multiple, stacked intrusive sheets. Two structural transects across the northwest lateral margin have identified distinct structural domains within the host rock that reflect both temporal and kinematic variations in deformation. Three deformation phases are identified, interpreted to be pre-, syn- and late-emplacement structures. A background set of deformation bands (phase 1), trending oblique to the intrusion margin, is apparent across the entire area. A second set of deformation bands (phase 2) overprint the early phase. These are characterised by conjugate deformation bands that parallel the intrusion margin, and increase in intensity and spacing towards the intrusion. Within this same zone a series of calcite filled normal faults, striking parallel and perpendicular to the intrusion margin, are apparent. Due to their spatial, kinematic and overprinting relationships we interpret these to be linked to the emplacement of the intrusive body. Overprinting all other structures, are two sets of tensile joints

  6. Ice marginal dynamics during surge activity, Kuannersuit Glacier, Disko Island, West Greenland

    Science.gov (United States)

    Roberts, David H.; Yde, Jacob C.; Knudsen, N. Tvis; Long, Antony J.; Lloyd, Jerry M.

    2009-02-01

    The Kuannersuit Glacier surged 11 km between 1995 and 1998. The surge resulted in the formation of an ice cored thrust moraine complex constructed by subglacial and proglacial glaciotectonic processes. Four main thrust zones are evident in the glacier snout area with phases of compressional folding and thrusting followed by hydrofracture in response to the build-up of compressional stresses and the aquicludal nature of submarginal permafrost and naled. Various types of stratified debris-rich ice facies occur within the marginal zone: The first (Facies I) comprises laterally continuous strata of ice with sorted sediment accumulations, and is reworked and thrust naled ice. The second is laterally discontinuous stratified debris-rich ice with distinct tectonic structures, and is derived through subglacial extensional deformation and localised regelation (Facies II), whilst the third type is characterised by reworked and brecciated ice associated with the reworking and entrainment of meteoric ice (Facies III). Hydrofracture dykes and sills (Facies IV) cross-cut the marginal ice cored thrust moraines, with their sub-vertically frozen internal contact boundaries and sedimentary structures, suggesting supercooling operated as high-pressure evacuation of water occurred during thrusting, but this is not related to the formation of basal stratified debris-rich ice. Linear distributions of sorted fines transverse to ice flow, and small stratified sediment ridges that vertically cross-cut the ice surface up-ice of the thrust zone relate to sediment migration along crevasse traces and fluvial infilling of crevasses. From a palaeoglaciological viewpoint, marginal glacier tectonics, ice sediment content and sediment delivery mechanisms combine to control the development of this polythermal surge valley landsystem. The bulldozing of proglacial sediments and the folding and thrusting of naled leads to the initial development of the outer zone of the moraine complex. This becomes

  7. Nature of crystalline particle assembly in ring shaped colloidal stains from concentrated dispersions

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Fenfen; Huynh, Trang [Laboratory for Optics and Applied Mechanics, Monash University, Clayton VIC 3800 (Australia); Somers, Anthony [Institute for Frontier Materials, Deakin University, 221 Burwood Highway, Burwood VIC 3125 Australia (Australia); Liu, Boyin; Fu, Jing [Department of Mechanical and Aerospace Engineering, Monash University, Clayton VIC 3800 (Australia); Muradoglu, Murat [Laboratory for Optics and Applied Mechanics, Monash University, Clayton VIC 3800 (Australia); Ng, Tuck Wah, E-mail: engngtw@gmail.com [Laboratory for Optics and Applied Mechanics, Monash University, Clayton VIC 3800 (Australia)

    2014-05-15

    The drying of colloidal droplet suspensions is important in many realms of practical application and has sustained the interest of researchers over two decades. The arrangements of polystyrene and silica beads, both of diameter 1 μm, 10% by volume of solid deposited on normal glass (hydrophilic), and silicone (hydrophobic) surfaces evaporated from a suspension volume of 3 μL, were investigated. Doughnut shape depositions were found, imputing the influence of strong central circulation flows that resulted in three general regions. In the central region which had strong particle build-up, the top most layers of particle arrangement was confirmed to be disordered using power spectrum and radial distribution function analysis. On closer examination, this appeared more like frustrated attempts to crystallize into larger grains rather than beads arranging in a disordered fashion throughout the piling process. With an adapted micro-bulldozing operation to progressively remove layers of particles from the heap, we found that the later efforts to crystallize through lateral capillary inter-particle forces were liable to be undone once the particles contacted the disorganized particles underneath, which were formed out of the jamming of fast particles arriving at the surface.

  8. Sounds and vibrations in the frozen Beaufort Sea during gravel island construction.

    Science.gov (United States)

    Greene, Charles R; Blackwell, Susanna B; McLennan, Miles Wm

    2008-02-01

    Underwater and airborne sounds and ice-borne vibrations were recorded from sea-ice near an artificial gravel island during its initial construction in the Beaufort Sea near Prudhoe Bay, Alaska. Such measurements are needed for characterizing the properties of island construction sounds to assess their possible impacts on wildlife. Recordings were made in February-May 2000 when BP Exploration (Alaska) began constructing Northstar Island about 5 km offshore, at 12 m depth. Activities recorded included ice augering, pumping sea water to flood the ice and build an ice road, a bulldozer plowing snow, a Ditchwitch cutting ice, trucks hauling gravel over an ice road to the island site, a backhoe trenching the sea bottom for a pipeline, and both vibratory and impact sheet pile driving. For all but one sound source (underwater measurements of pumping) the strongest one-third octave band was under 300 Hz. Vibratory and impact pile driving created the strongest sounds. Received levels of sound and vibration, as measured in the strongest one-third octave band for different construction activities, reached median background levels <7.5 km away for underwater sounds, <3 km away for airborne sounds, and <10 km away for in-ice vibrations.

  9. Negotiating Time: Design as Historical Practice

    Directory of Open Access Journals (Sweden)

    Cindy Lin

    2016-08-01

    Full Text Available In North Jakarta, the bulldozed remnants of the April 11 (2016 eviction of Kampung Pasar Ikan presented a site of radical transformation and urban planning. The eviction was in part motivated by a Dutch-Indonesian alliance, to construct a 40 billion USD sea wall and reclaimed islands to prevent the city from slowly sinking. In this text we start by asking, how are people living in Pasar Ikan responding to and enacting their own futures through repair? What does repair in a landscape of complete disrepair look like? And how is history both erased and enacted in this process? We then move to West Kalimantan where a DIY drone collective makes aerial drone technology and trains groups to map land that they say is vulnerable to incursions by resource developers. We ask, how is the forest located, recognized and constituted by these and other cartographic practices? Whose time and in what time are forest boundaries set and reset by mapping techniques in West Kalimantan? How do these cartographies become artifacts that travel and influence how history is thought and practiced?

  10. Bioenergy recovery from landfill gas: A case study in China

    Institute of Scientific and Technical Information of China (English)

    Wei WANG; Yuxiang LUO; Zhou DENG

    2009-01-01

    Landfill gas (LFG) utilization which means a synergy between environmental protection and bioenergy recovery was investigated in this study. Pressure swing adsorption technology was used in LFG purification, and laboratory experiment, pilot-scale test, and on-site demon-stration were carried out in Shenzhen, China. In the laboratory experiment, A-type carbon molecular sieve was selected as the adsorbent by comparison of several other adsorbents. The oPtimal adsorption pressure and adsorp-tion time were 0.25 MPa and 2 min, respectively, under which the product generation rate was 4.5 m3/h and the methane concentration was above 90%. The process and optimization of the pilot-scale test were also reported in the paper. The product gas was of high quality compared with the National Standard of Compressed Natural Gas as Vehicle Fuel (GB 18047-2000), when the air concentration in feed gas was under 10.96%. The demonstration project was composed of a collection system, production system,and utilization system. The drive performance, environ-mental protection performance, and economic feasibility of the product gas -- as alternative fuel in passenger car,truck, and bulldozer-were tested, showing the feasibility technology for LFG utilization.

  11. [An occupational physiology study at the Asarel Mining and Milling Works--screening for risk factors of the cardiovascular system in workers in an open-pit mine].

    Science.gov (United States)

    Mincheva, L; Khadzhiolova, I

    1995-01-01

    It was the purpose of this study to define the frequency of occurrence of a number of individual and occupational factors contributing to development of arterial hypertension in "Asarel" MMW open-pit workers. The investigated subjects numbered 36 and ranged in age from 22 to 55 years (average, 36 +/- 1.9 years). The jobs represented included mainly: diggers, bulldozers, driver, drillers, blasters, road-service workers, electric and mechanic fitters. Endpoints measured and evaluated included: arterial blood pressure, pulse rate, biometric characteristics (age, occupational experience, body height and weight), common risk factors, such as family antecedents, cigarette smoking, alcohol consumption, level of physical activity at and off work, etc. For this sample of open-pit workers, findings indicated a relatively high incidence of hypertension (28% of subjects). The level of arterial hypertension consistently correlated with worker age, length of occupational experience, and body weight. There was high prevalence of cardiovascular risk factors: alcohol consumption, family history, cigarette smoking, use of salty foods, overweight. The observed changes in the cardiovascular system and high prevalence of risk factors point to the necessity of taking specific medical prevention measures. These have been taken into consideration in designing the overall program of upgrading work conditions and organization, as well as improving the style of life of "Asarel" MMW workers. PMID:8524751

  12. Trace fossils from Eocene turbiditic deposits: A case study from the Slovak-Moravian Carpathians

    Directory of Open Access Journals (Sweden)

    Starek Dušan

    2015-12-01

    Full Text Available Well exposed, poorly bioturbated turbiditic sandstones of the Kýčera Beds (Zlín Formation; Eocene in the Bieščary Quarry contain the deep-sea Nereites ichnofacies. The trace fossils Ophiomorpha rudis, Halopoa annulata and Scolicia strozzii are mainly common in thick-bedded sandstone packages. They represent the Ophiomorpha rudis ichnosubfacies. Paleodiction strozzii, Nereites irregularis, and Zoophycos brianteus occur in a series of thin- to medium bedded fine grained turbiditic sandstones intercalated with mudstone shales. They belong to the Paleodictyon–Nereites ichnosubfacies. The sedimentological interpretation of the turbidity facies and the distribution of the trace fossils suggest that the recognized ichnosubfacies probably express a non-bathymetric facies trend from channel axis, levee to overbank or inter-channel/interlobe areas of a deep sea fan. The distribution and preservation of trace fossils depend mostly on lithology, sedimentation rate, erosion and amalgamation of beds in the proximal mid fan areas, bulldozing effect during colonization as well as on the hardly quantified effect of bottom oxygenation and supply of nutrients.

  13. Automatic control technique for construction of work; Kensetsu koji seko ni okeru jidoka gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, T. [Ministry of Agriculture Forestry and Fisheries, Tokyo (Japan)

    1996-03-01

    In this article, the history of development of construction technology in Japan after the Second World War is outlined, in addition, automation of work and supervision in the latest construction works is explained relatively in detail, and the trend of automated and manpower saving works in the future is shown. Regarding the development of construction technology after the war in Japan, it started with the introduction of new construction methods, etc. of the U.S.A. and the Netherland for business of restoration immediately after the war and also the mechanized technology such as bulldozers was studied. After that, technology concerning reclamation, construction of dams and irrigation channels and construction of tunnels and bridges progressed. Regarding the latest construction works, explanations are given on the two fields, namely automation and manpower saving of construction works and automation and manpower saving of construction supervision. Concerning the former field, automation of works laying dam concrete, automation of treatment of joint between laid dam concrete, mechanization of removal work of the core surface water, etc. are described and regarding the latter, supervision of compacting banking, photo supervision with digital cameras, etc. are referred to. The article also hints the trend in the future. 4 refs., 5 figs..

  14. Dynamic Modeling and Soil Mechanics for Path Planning of the Mars Exploration Rovers

    Science.gov (United States)

    Trease, Brian; Arvidson, Raymond; Lindemann, Randel; Bennett, Keith; Zhou, Feng; Iagnemma, Karl; Senatore, Carmine; Van Dyke, Lauren

    2011-01-01

    To help minimize risk of high sinkage and slippage during drives and to better understand soil properties and rover terramechanics from drive data, a multidisciplinary team was formed under the Mars Exploration Rover (MER) project to develop and utilize dynamic computer-based models for rover drives over realistic terrains. The resulting tool, named ARTEMIS (Adams-based Rover Terramechanics and Mobility Interaction Simulator), consists of the dynamic model, a library of terramechanics subroutines, and the high-resolution digital elevation maps of the Mars surface. A 200-element model of the rovers was developed and validated for drop tests before launch, using MSC-Adams dynamic modeling software. Newly modeled terrain-rover interactions include the rut-formation effect of deformable soils, using the classical Bekker-Wong implementation of compaction resistances and bull-dozing effects. The paper presents the details and implementation of the model with two case studies based on actual MER telemetry data. In its final form, ARTEMIS will be used in a predictive manner to assess terrain navigability and will become part of the overall effort in path planning and navigation for both Martian and lunar rovers.

  15. Aeolian sediment transport and landforms in managed coastal systems: A review

    Science.gov (United States)

    Jackson, Nancy L.; Nordstrom, Karl F.

    2011-11-01

    Humans modify beaches and dunes and aeolian transport potential by building structures, walking or driving, extracting resources, accommodating recreation, increasing levels of protection, removing storm deposits, or restoring landforms and habitats. The effects of human adjustments are reviewed here in terms of cross-shore zones because humans tend to compartmentalize landforms and habitats through their actions and regulations. Common human modifications in the beach zone include nourishing beaches, constructing shore protection structures and raking to remove litter. Modifications affecting the dune zone include altering the location, size and stability of dunes using sand-trapping fences, vegetation plantings and bulldozers or replacing dunes with shore-parallel structures. Modifications affecting the landward zone include buildings, roads, and parking lots. Landform and habitat resilience requires levels of dynamism and geomorphic complexity not often found in managed systems. Preserving or enhancing dynamism and complexity requires emphasis on innovative designs rooted in geomorphological and aeolian research. Future studies are suggested for: (1) quantifying the effect of small and large scale beach nourishment designs and sediment characteristics on dune initiation, development, and evolution; (2) quantifying the extent to which size and spacing of human structures and landform alterations inhibit sediment transfers alongshore or onshore; (3) identifying the advantages or disadvantages of "niche" dunes formed by structures; (4) providing quantitative data on the effects of raking or driving on the beach; (5) identifying the role of aeolian landforms on private properties; and (6) identifying alternative ways of employing sand fences and vegetation plantings to increase topographic and habitat diversity.

  16. Indirect estimation of emission factors for phosphate surface mining using air dispersion modeling.

    Science.gov (United States)

    Tartakovsky, Dmitry; Stern, Eli; Broday, David M

    2016-06-15

    To date, phosphate surface mining suffers from lack of reliable emission factors. Due to complete absence of data to derive emissions factors, we developed a methodology for estimating them indirectly by studying a range of possible emission factors for surface phosphate mining operations and comparing AERMOD calculated concentrations to concentrations measured around the mine. We applied this approach for the Khneifiss phosphate mine, Syria, and the Al-Hassa and Al-Abyad phosphate mines, Jordan. The work accounts for numerous model unknowns and parameter uncertainties by applying prudent assumptions concerning the parameter values. Our results suggest that the net mining operations (bulldozing, grading and dragline) contribute rather little to ambient TSP concentrations in comparison to phosphate processing and transport. Based on our results, the common practice of deriving the emission rates for phosphate mining operations from the US EPA emission factors for surface coal mining or from the default emission factor of the EEA seems to be reasonable. Yet, since multiple factors affect dispersion from surface phosphate mines, a range of emission factors, rather than only a single value, was found to satisfy the model performance. PMID:26971219

  17. Spatial patterns in meiobenthic assemblages in intermittently open/closed coastal lakes in New South Wales, Australia

    Science.gov (United States)

    Dye, A. H.; Barros, F.

    2005-03-01

    Intermittently closed and open lakes and lagoons (ICOLLs) are important features of the Australian coastline. Local authorities frequently open lakes by bulldozing or dredging the mouths, in an effort to improve water-quality and to reduce the risk of flooding and these interventions provided an opportunity to examine large-scale patterns in meiobenthos in relation to isolation from the sea. Even at a coarse level of taxonomic resolution (phylum, class and order), consistent differences between assemblages of meiobenthos in different reaches of the lakes and between open and closed lakes were revealed. The abundance of meiobenthos generally decreased with increasing distance from the sea. Multivariate analyses showed that nematodes, copepods and turbellarians were characteristic of assemblages near the mouths of lakes while polychaetes and oligochaetes characterised those in more isolated areas. Furthermore, assemblages in the inner reaches of open lakes also differed from those in closed lakes. Isolated localities were less diverse and more spatially variable. Differences in meiobenthos between natural lakes and those that are artificially opened became apparent when open and closed were analysed separately. Lakes that are kept open artificially are similar to naturally open lakes despite other impacts associated with human activities. These results are considered in the context of isolation and the implications of proposed changes in the way mouths are manipulated are discussed.

  18. Spatial variability of soil chemical properties after coffee tree removal Variabilidade espacial dos atributos químicos do solo após remoção de cafezal

    Directory of Open Access Journals (Sweden)

    Sidney Rosa Vieira

    2009-10-01

    Full Text Available Assessing the spatial variability of soil chemical properties has become an important aspect of soil management strategies with a view to higher crop yields with minimal environmental degradation. This study was carried out at the Centro Experimental of the Instituto Agronomico, in Campinas, São Paulo, Brazil. The aim was to characterize the spatial variability of chemical properties of a Rhodic Hapludox on a recently bulldozer-cleaned area after over 30 years of coffee cultivation. Soil samples were collected in a 20 x 20 m grid with 36 sampling points across a 1 ha area in the layers 0.0-0.2 and 0.2-0.4 m to measure the following chemical properties: pH, organic matter, K+, P, Ca2+, Mg2+, potential acidity, NH4-N, and NO3-N. Descriptive statistics were applied to assess the central tendency and dispersion moments. Geostatistical methods were applied to evaluate and to model the spatial variability of variables by calculating semivariograms and kriging interpolation. Spatial dependence patterns defined by spherical model adjusted semivariograms were made for all cited soil properties. Moderate to strong degrees of spatial dependence were found between 31 and 60 m. It was still possible to map soil spatial variability properties in the layers 0-20 cm and 20-40 cm after plant removal with bulldozers.A avaliação da variabilidade espacial dos atributos químicos do solo tem se tornado importante ferramenta na determinação de estratégias de manejo que visam aumentar a produtividade agrícola com menor degradação ambiental. O presente trabalho foi realizado no Centro Experimental Central do Instituto Agronômico, localizado em Campinas/SP, com o objetivo de caracterizar a variabilidade espacial dos atributos químicos de um Latossolo Vermelho após a remoção de um cafezal, cultivado por mais de 30 anos, com trator de esteira. As amostras de solo foram coletadas em grade georreferenciada de 20 x 20 m, totalizando 36 pontos nas camadas de 0

  19. 森林火灾扑救消防车装备的种类及使用技术%Kinds of Fire Engines and Technology Used in Forest Fire Suppression

    Institute of Scientific and Technical Information of China (English)

    高仲亮; 王秋华; 舒立福; 张明远

    2014-01-01

    森林消防车作为大型森林消防设备,包括森林消防推土机、森林消防越野车和森林消防指挥车,是扑救中高强度火和控制大面积森林火灾的主力。森林消防推土机能开辟通道和防火隔离带,扑救地下火;森林消防越野车具备良好的越野性能,能承载数吨水或灭火剂扑救中高强度的火灾;森林消防指挥车能实现多种通信方式互联,完成高清图像和视频的实时传输,辅助指挥人员进行扑火指挥调度和决策,提高扑火效率,保障扑火人员安全。森林消防车在火灾扑救中发挥了优越的响应性能、灭火性能、运载性能、越野性能和行车清障性能以及通信性能。高新技术和新型材料的应用,以及多功能、全地形森林消防车的研制将进一步提高森林消防车的技术性能。%As large forest firefighting equipment, forest engines consist of forest fire bulldozers, off-road vehicles and com-mand vehicles, which are the main force for suppressing medium-high strength fire and controlling large area forest fire. For-est fire bulldozers can open up channels and fire breaks, and rescue ground fire. Forest fire off-road vehicles have good cross-country equipment, and can carry tons of water or fire extinguishing agent to suppress medium-high strength fire. For-est fire command vehicles can also achieve interconnection of many communication ways, transmission of high-definition im-ages and real-time videos, and assist commanders to blaze scheduling command and make decisions,which can improve the efficiency of fire suppression and ensure safety of fire personnel. Forest engines bring out excellent performance in terms of response, fire suppression, delivery, cross-country, road block removal and communication. The application of advanced technology and new materials and the development of multifunctional and all-terrain forest engines will improve the perfor-mance of forest engines in

  20. Effectiveness of the GAEC standard of cross compliance Prohibition of performing unauthorized land levelling on soil erosion control

    Directory of Open Access Journals (Sweden)

    Paolo Bazzoffi

    2011-08-01

    Full Text Available The GAEC standard land levelling under authorization of cross compliance prohibits farmers from levelling land through bulldozing without a specific permission issued by the proper territorial authority. The aim of the standard is to ensure the protection of soil from accelerated erosion that almost always occurs when land is levelled without conservative criteria. Land levelling prior to planting or replanting specialized crops, especially orchards, is indicated by agronomists as essential to the full mechanization of cultivation and harvesting operations and the success of economic investment. Land levelling leads to a deep modification of the hill slopes, so it may produce serious damage to the environment if carried out in the absence of a carefully planned design. In other words, a design that takes the aspects of soil conservation into account, especially for steep hill slopes where the insite and offsite environmental impacts of soil erosion may be more pronounced. With regard to the areas involved, land levelling plays a key role on a national scale, one only needs to think of the vineyards planted on the country’s hill slopes, which in 1970 covered an area of 793,000 hectares. Moreover, despite the continued reduction in areas planted with vines, from 1990 to 2002 the area devoted to DOC and DOCG wines increased by about 29% and the average size of vineyards has also increased. This is a clear sign of the current trend, with the transition from the family model to the industrial model of orchard management, with extensive use of machinery and thus the use of bulldozers for levelling. The authorization topic, on which the standard of compliance is based, is analysed in detail. In summary we can say that, according to law, the permit required by the GAEC standard is currently mandatory only for those areas subject to the Hydrogeological constraint (Royal decree 30 December 1923 No. 3267 and for parks or other areas for which the

  1. Non-linear interactions between consumers and flow determine the probability of plant community dominance on Maine rocky shores.

    Directory of Open Access Journals (Sweden)

    Brian R Silliman

    Full Text Available Although consumers can strongly influence community recovery from disturbance, few studies have explored the effects of consumer identity and density and how they may vary across abiotic gradients. On rocky shores in Maine, recent experiments suggest that recovery of plant- or animal- dominated community states is governed by rates of water movement and consumer pressure. To further elucidate the mechanisms of consumer control, we examined the species-specific and density-dependent effects of rocky shore consumers (crabs and snails on community recovery under both high (mussel dominated and low flow (plant dominated conditions. By partitioning the direct impacts of predators (crabs and grazers (snails on community recovery across a flow gradient, we found that grazers, but not predators, are likely the primary agent of consumer control and that their impact is highly non-linear. Manipulating snail densities revealed that herbivorous and bull-dozing snails (Littorina littorea alone can control recovery of high and low flow communities. After ∼1.5 years of recovery, snail density explained a significant amount of the variation in macroalgal coverage at low flow sites and also mussel recovery at high flow sites. These density-dependent grazer effects were were both non-linear and flow-dependent, with low abundance thresholds needed to suppress plant community recovery, and much higher levels needed to control mussel bed development. Our study suggests that consumer density and identity are key in regulating both plant and animal community recovery and that physical conditions can determine the functional forms of these consumer effects.

  2. HOUDINI: RECONFIGURABEL IN-TANK ROBOT

    International Nuclear Information System (INIS)

    This report details the development of a reconfigurable in-tank robotic cleanup systems called Houdini(trademark). Driven by the general need to develop equipment for the removal of radioactive waste from hundreds of DOE waste storage tanks and the specific needs of DOE sites such as Oak Ridge National Laboratory and Fernald, Houdini(trademark) represents one of the possible tools that can be used to mobilize and retrieve this waste material for complete remediation. Houdini(trademark) is a hydraulically powered, track driven, mobile work vehicle with a collapsible frame designed to enter underground or above ground waste tanks through existing 24 inch riser openings. After the vehicle has entered the waste tank, it unfolds and lands on the waste surface or tank floor to become a remotely operated mini-bulldozer. Houdini(trademark) utilizes a vehicle mounted plow blade and 6-DOF manipulator to mobile waste and carry other tooling such as sluicing pumps, excavation buckets, and hydraulic shears. The complete Houdini(trademark) system consists of the tracked vehicle and other support equipment (e.g., control console, deployment system, hydraulic power supply, and controller) necessary to deploy and remotely operate this system at any DOE site. Inside the storage tanks, the system is capable of performing heel removal, waste mobilization, waste size reduction, and other tank waste retrieval and decommissioning tasks. The first Houdini(trademark) system was delivered on September 24, 1996 to Oak Ridge National Laboratory (ORNL). The system acceptance test was successfully performed at a cold test facility at ORNL. After completion of the cold test program and the training of site personnel, ORNL will deploy the system for clean-up and remediation of the Gunite storage tanks

  3. Hydraulic manipulator design, analysis, and control at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.; Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States); Basher, A.M.H. [South Carolina State Univ., Orangeburg, SC (United States)

    1996-09-01

    To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned to hydraulics as a means of actuation. Hydraulics have always been the actuator of choice when designing heavy-life construction and mining equipment such as bulldozers, backhoes, and tunneling devices. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem) sophisticated modeling, analysis, and control experiments are usually needed. To support the development and deployment of new hydraulic manipulators Oak Ridge National Laboratory (ORNL) has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The hydraulics laboratory at ORNL has three different manipulators. First is a 6-Degree-of-Freedom (6-DoF), multi-planer, teleoperated, flexible controls test bed used for the development of waste tank clean-up manipulator controls, thermal studies, system characterization, and manipulator tracking. Finally, is a human amplifier test bed used for the development of an entire new class of teleoperated systems. To compliment the hardware in the hydraulics laboratory, ORNL has developed a hydraulics simulation capability including a custom package to model the hydraulic systems and manipulators for performance studies and control development. This paper outlines the history of hydraulic manipulator developments at ORNL, describes the hydraulics laboratory, discusses the use of the equipment within the laboratory, and presents some of the initial results from experiments and modeling associated with these hydraulic manipulators. Included are some of the results from the development of the human amplifier/de-amplifier concepts, the characterization of the thermal sensitivity of hydraulic systems, and end-point tracking accuracy studies. Experimental and analytical

  4. Houdini{trademark}: Reconfigurable in-tank mobile robot. Final report, June 1995--January 1997

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, B.; Slifko, A.

    1998-12-31

    This report details the development of a reconfigurable in-tank robotic cleanup system called Houdini{trademark}. Driven by the general need to develop equipment for the removal of radioactive waste from hundreds of DOE waste storage tanks and the specific needs of DOE sites such as Oak Ridge National Laboratory and Fernald, Houdini{trademark} represents one of the possible tools that can be used to mobilize and retrieve this waste material for complete remediation. Houdini{trademark} is a hydraulically powered, track driven, mobile work vehicle with a collapsible frame designed to enter underground or above ground waste tanks through existing 24 inch riser openings. After the vehicle has entered the waste tank, it unfolds and lands on the waste surface or tank floor to become a remotely operated mini-bulldozer. Houdini{trademark} utilizes a vehicle mounted plow blade and 6-DOF manipulator to mobilize waste and carry other tooling such as sluicing pumps, excavation buckets, and hydraulic shears. The complete Houdini{trademark} system consists of the tracked vehicle and other support equipment (e.g., control console, deployment system, hydraulic power supply, and controller) necessary to deploy and remotely operate this system at any DOE site. Inside the storage tanks, the system is capable of performing heel removal, waste mobilization, waste size reduction, and other tank waste retrieval and decommissioning tasks. The first Houdini{trademark} system was delivered on September 24, 1996 to Oak Ridge National Laboratory (ORNL). The system acceptance test was successfully performed at a cold test facility at ORNL. After completion of the cold test program and the training of site personnel, ORNL will deploy the system for clean-up and remediation of the Gunite storage tanks.

  5. The Clearing : Heidegger’s Lichtung and the big scrub

    Directory of Open Access Journals (Sweden)

    Garbutt, Rob

    2010-01-01

    Full Text Available Clearings make settlement possible. Whether on a small scale using an axe and other hand implements to make way for a dwelling and a garden, or on a large scale with a chain strung between two D9 bulldozers in preparation for a major agribusiness development, the process of clearing creates spaces for installing something new. This paper uses the idea of (the clearing, as practice, process, outcome and metaphor, to examine the installation of the locals in a settler society. Using Lismore on the far-north coast of New South Wales, Australia, as a case example, the particular work of clearing that is discussed here is a practice that enables a form of colonisation and settlement that distances itself from its history of migration. This is a history of settler locals who were 'always here', and a colonial form of clearing clears the land and the mind of troubling pasts and of troubling presences. For the locals within a place, then, clearing manages and simplifies a complex set of social and material relations, histories and identities.Using Anthony Appiah's concept the 'space clearing gesture', the paper concludes with a reflection on the space in which the idea of "the clearing" and this paper appears. Do places, in this instance rural places, provide a type of clearing in which certain ideas might appear that may not appear elsewhere? If situatedness matters then the diversity of places where thinking is done is important for our ecology of thought, and in connection with this, perhaps what 'rural cultural studies' does is clear a particular type of space for thinking.

  6. Phase 1 archaeological investigation, cultural resources survey, Hawaii Geothermal Project, Makawao and Hana districts, south shore of Maui, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Erkelens, C. [International Archaeological Research Inst., Inc., Honolulu, HI (United States)

    1995-04-01

    This report details the archaeological investigation of a 200 foot wide sample corridor extending approximately 9 miles along the southern portion of Maui within the present districts of Hana and Makawao. The survey team documented a total of 51 archaeological sites encompassing 233 surface features. Archaeological sites are abundant throughout the region and only become scarce where vegetation has been bulldozed for ranching activities. At the sea-land transition points for the underwater transmission cable, both Ahihi Bay and Huakini Bay are subjected to seasonal erosion and redeposition of their boulder shorelines. The corridor at the Ahihi Bay transition point runs through the Maonakala Village Complex which is an archaeological site on the State Register of Historic Places within a State Natural Area Reserve. Numerous other potentially significant archaeological sites lie within the project corridor. It is likely that rerouting of the corridor in an attempt to avoid known sites would result in other undocumented sites located outside the sample corridor being impacted. Given the distribution of archaeological sites, there is no alternative route that can be suggested that is likely to avoid encountering sites. Twelve charcoal samples were obtained for potential taxon identification and radiocarbon analysis. Four of these samples were subsequently submitted for dating and species identification. Bird bones from various locations within a lava tube were collected for identification. Sediment samples for subsequent pollen analysis were obtained from within two lava tubes. With these three sources of information it is hoped that paleoenvironmental data can be recovered that will enable a better understanding of the setting for Hawaiian habitation of the area.

  7. Decontamination and Decommissioning of the Tokamak Fusion Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    E. Perry; J. Chrzanowski; K. Rule; M. Viola; M. Williams; R. Strykowsky

    1999-11-01

    The Tokamak Fusion Test Reactor (TFTR) is a one-of-a-kind, tritium-fueled fusion research reactor that ceased operation in April 1997. The Decontamination and Decommissioning (D and D) of the TFTR is scheduled to occur over a period of three years beginning in October 1999. This is not a typical Department of Energy D and D Project where a facility is isolated and cleaned up by ''bulldozing'' all facility and hardware systems to a greenfield condition. The mission of TFTR D and D is to: (a) surgically remove items which can be re-used within the DOE complex, (b) remove tritium contaminated and activated systems for disposal, (c) clear the test cell of hardware for future reuse, (d) reclassify the D-site complex as a non-nuclear facility as defined in DOE Order 420.1 (Facility Safety) and (e) provide data on the D and D of a large magnetic fusion facility. The 100 cubic meter volume of the donut-shaped reactor makes it the second largest fusion reactor in the world. The record-breaking deuterium-tritium experiments performed on TFTR resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 Mev neutrons. The total tritium content within the vessel is in excess of 7,000 Curies while dose rates approach 75 mRem/hr. These radiological hazards along with the size and shape of the Tokamak present a unique and challenging task for dismantling.

  8. Herbivore-Alga Interaction Strength Influences Spatial Heterogeneity in a Kelp-Dominated Intertidal Community.

    Science.gov (United States)

    Aguilera, Moisés A; Valdivia, Nelson; Broitman, Bernardo R

    2015-01-01

    There is a general consensus that marine herbivores can affect algal species composition and abundance, but little empirical work exists on the role of herbivores as modifiers of the spatial structure of resource assemblages. Here, we test the consumption/bulldozing effects of the molluscan grazer Enoplochiton niger and its influence on the spatial structure of a low intertidal community dominated by the bull kelp Durvillaea antarctica and the kelp Lessonia spicata. Through field experiments conducted at a rocky intertidal shore in north-central Chile (~30°-32°S), the edge of the grazer and algae geographic distributions, we estimated the strength and variability of consumptive effects of the grazer on different functional group of algae. We also used data from abundance field surveys to evaluate spatial co-occurrence patterns of the study species. Exclusion-enclosure experiments showed that E. niger maintained primary space available by preventing algal colonization, even of large brown algae species. The grazing activity of E. niger also reduced spatial heterogeneity of the ephemeral algal species, increasing bare space availability and variability through time in similar ways to those observed for the collective effect with other grazers. Overall, our result suggests that E. niger can be considered an important modifier of the spatial structure of the large brown algae-dominated community. Effects of E. niger on resource variability seem to be directly related to its foraging patterns, large body size, and population densities, which are all relevant factors for management and conservation of the large brown algae community. Our study thus highlights the importance of considering functional roles and identity of generalist consumers on spatial structure of the entire landscape. PMID:26360294

  9. Restoring Alternate Bar Sequences in Large Rivers: Flow, Sediment, and Elbow Room

    Science.gov (United States)

    Trush, W. J.; McBain, S. M.

    2006-12-01

    Large river management must rely on crucial premises that the river channel is a product of its watershed's hydrology and the space within which it moves, and that native plant and animal species have evolved with, and still depend on, the natural annual hydrograph. While interesting academically, these premises may appear to offer very limited utility as management tools, given few large rivers in the Pacific Northwest and elsewhere have escaped major hydrologic and geomorphic change. The opposite, however, is likely true. Without reconstructing and incorporating an historical perspective, large river restoration will fail. Healthy river ecosystems can be achieved without completely restoring the natural unregulated hydrology, sediment supply regime, and original migration corridor. Usually there is little choice. An historical perspective identifies crucial threshold streamflow, sediment, and corridor processes driving a healthy river ecosystem. Alternating point bar sequences are the building blocks of alluvial rivers that also function as the physical template for creating abundant, high quality habitat for fish, amphibians, and riparian plant. While alternating bars can be created with bulldozers, their evolution, longevity, and quality will endure only if key geomorphic and biological threshold processes are provided by naturally variable annual hydrographs. An historical perspective therefore must identify how unregulated annual hydrographs once created and fostered dynamic alternating bar sequences. Restoration practitioners must then devise ways to restore these processes while purposefully cheating Mother Nature of some of her flow, sediment, and corridor width (elbow room). Two commonly prescribed high flow releases, flushing flows and the bankfull discharge, address several geomorphic requirements yet neither, or the two combined, can restore and maintain alternating bar sequences. Higher flood peak magnitudes from winter floods and spring snowmelt

  10. Lithology, fault displacement, and origin of secondary calcium carbonate and opaline silica at Trenches 14 and 14D on the Bow Ridge Fault at Exile Hill, Nye County, Nevada

    International Nuclear Information System (INIS)

    Yucca Mountain, a proposed site for a high-level nuclear-waste repository, is located in southern Nevada, 20 km east of Beatty, and adjacent to the southwest comer of the Nevada Test Site (NTS) (fig. 1). Yucca Mountain is located within the Basin and Range province of the western United States. The climate is semiarid, and the flora is transitional between that of the Mojave Desert to the south and the Great Basin Desert to the north. As part of the evaluation, hydrologic conditions, especially water levels, of Yucca Mountain and vicinity during the Quaternary, and especially the past 20,000 years, are being characterized. In 1982, the US Geological Survey, in cooperation with the US Department of Energy (under interagency agreement DE-A104-78ET44802), excavated twenty-six bulldozer and backhoe trenches in the Yucca Mountain region to evaluate the nature and frequency of Quaternary faulting (Swadley and others, 1984). The trenches were oriented perpendicular to traces of suspected Quaternary faults and across projections of known bedrock faults into Quaternary deposits. Trench 14 exposes the Bow Ridge Fault on the west side of Exile Hill. Although the original purpose of the excavation of trench 14 was to evaluate the nature and frequency of Quaternary faulting on the Bow Ridge Fault, concern arose as to whether or not the nearly vertical calcium carbonate (the term ''carbonate'' in this study refers to calcium carbonate) and opaline silica veins in the fault zone were deposited by ascending waters (ground water). These veins resemble in gross morphology veins commonly formed by hydrothermal processes

  11. The Clearing: Heidegger’s Lichtung and The Big Scrub

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2010-02-01

    Full Text Available Clearings make settlement possible. Whether on a small scale using an axe and other hand implements to make way for a dwelling and a garden, or on a large scale with a chain strung between two D9 bulldozers in preparation for a major agribusiness development, the process of clearing creates spaces for installing something new. This paper uses the idea of (the clearing, as practice, process, outcome and metaphor, to examine the installation of the locals in a settler society. Using Lismore on the far-north coast of New South Wales, Australia, as a case example, the particular work of clearing that is discussed here is a practice that enables a form of colonisation and settlement that distances itself from its history of migration. This is a history of settler locals who were 'always here', and a colonial form of clearing clears the land and the mind of troubling pasts and of troubling presences. For the locals within a place, then, clearing manages and simplifies a complex set of social and material relations, histories and identities. Using Anthony Appiah's concept the 'space clearing gesture', the paper concludes with a reflection on the space in which the idea of "the clearing" and this paper appears. Do places, in this instance rural places, provide a type of clearing in which certain ideas might appear that may not appear elsewhere? If situatedness matters then the diversity of places where thinking is done is important for our ecology of thought, and in connection with this, perhaps what 'rural cultural studies' does is clear a particular type of space for thinking.

  12. Surface radiological investigations at the proposed SWSA 7 Site, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, S.P.; Murray, M.E.; Uziel, M.S.

    1995-08-01

    A surface radiological investigation was conducted intermittently from June 1994 to June 1995 at the proposed site for Solid Waste Storage Area (SWSA) 7. The stimulus for this survey was the observation in June 1992 of a man`s trousers became contaminated with {sup 9O}Sr while he was reviewing work on top of the High Flux Isotope Reactor (HFIR) cooling tower. Radiation surveys identified {sup 9O}Sr on the roofs of older buildings at the HFIR site. Since no {sup 9O}Sr was found on buildings built between 1988 and 1990, the {sup 9O}Sr was thought to have been deposited prior to 1988. Later in 1992, beta particles were identified on a bulldozer that had been used in a wooded area southwest of the Health Physics Research Reactor (HPRR) Access Road. More recently in April 1995, {sup 9O}Sr particles were identified on the top side of ceiling tiles in the overhead area of a building in the HFIR Complex. Considering that the proposed SWSA 7 site was located between the HFIR complex and the HPRR Access Road, it was deemed prudent to investigate the possibility that beta particles might also be present at the SWSA 7 site. A possible explanation for the presence of these particles has been provided by long-time ORNL employees and retirees. Strontium-90 as the titanate was developed in the early 1960s as part of the Systems for Nuclear Auxiliary Power (SNAP) Program. Strontium titanate ({sup 90}SrTiO{sub 3}) was produced at the Fission Product Development Laboratory (Building 3517) in the ORNL main plant area. Waste from the process was loaded into a 1-in. lead-lined dumpster, which was transferred to SWSA 5 where it was dumped into a trench. Dumping allowed some articles to become airborne.

  13. Renewed mining and reclamation: Imapacts on bats and potential mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, P.E. [Univ. of California, Los Angeles, CA (United States); Berry, R.D. [Brown-Berry Biological Consulting, Bishop, CA (United States)

    1997-12-31

    Historic mining created new roosting habitat for many bat species. Now the same industry has the potential to adversely impact bats. Contemporary mining operations usually occur in historic districts; consequently the old workings are destroyed by open pit operations. Occasionally, underground techniques are employed, resulting in the enlargement or destruction of the original workings. Even during exploratory operations, historic mine openings can be covered as drill roads are bulldozed, or drills can penetrate and collapse underground workings. Nearby blasting associated with mine construction and operation can disrupt roosting bats. Bats can also be disturbed by the entry of mine personnel to collect ore samples or by recreational mine explorers, since the creation of roads often results in easier access. In addition to roost disturbance, other aspects of renewed mining can have adverse impacts on bat populations, and affect even those bats that do not live in mines. Open cyanide ponds, or other water in which toxic chemicals accumulate, can poison bats and other wildlife. The creation of the pits, roads and processing areas often destroys critical foraging habitat, or change drainage patterns. Finally, at the completion of mining, any historic mines still open may be sealed as part of closure and reclamation activities. The net result can be a loss of bats and bat habitat. Conversely, in some contemporary underground operations, future roosting habitat for bats can be fabricated. An experimental approach to the creation of new roosting habitat is to bury culverts or old tires beneath waste rock. Mining companies can mitigate for impacts to bats by surveying to identify bat-roosting habitat, removing bats prior to renewed mining or closure, protecting non-impacted roost sites with gates and fences, researching to identify habitat requirements and creating new artificial roosts.

  14. Effects of habitat disturbance on survival rates of softshell turtles (Apalone spinifera) in an urban stream

    Science.gov (United States)

    Plummer, M.V.; Krementz, D.G.; Powell, L.A.; Mills, N.E.

    2008-01-01

    We monitored Spiny Softshell Turtles (Apalone spinifera) using mark-recapture during 1994-2005 in Gin Creek, Searcy, Arkansas. In 1997-2000 the creek bed and riparian zone were bulldozed in an effort to remove debris and improve water flow. This disturbance appeared to reduce the quantity and quality of turtle habitat. We tested for the potential effect of this habitat disturbance on the survival rates of marked turtles. We estimated annual survival rates for the population using models that allowed for variation in survival by state of maturation, year, and effects of the disturbance; we evaluated two different models of the disturbance impact. The first disturbance model incorporated a single change in survival rates, following the disturbance, whereas the second disturbance model incorporated three survival rates: pre- and postdisturbance, as well as a short-term decline during the disturbance. We used a state-transition model for our mark-recapture analysis, as softshells transition from juveniles to adults in a variable period of time. Our analysis indicated that survival varied by maturation state and was independent of a time trend or the disturbance. Annual survival rates were lower for juveniles (S?? = 0.717, SE = 0.039) than for adults (S?? = 0.836, SE = 0.025). Despite the dramatic habitat disturbance, we found no negative effects on survival rates. Our results demonstrate that, like a few other freshwater turtle species known to thrive in urban environments, populations of A. spinifera are resilient and can persist in urban environments despite periodic habitat disturbances. Copyright 2008 Society for the Study of Amphibians and Reptiles.

  15. Deep India meets deep Asia: a seismological view of lithospheric slab interactions under Hindu Kush and Pamir

    Science.gov (United States)

    Schurr, Bernd; Kufner, Sofia; Sippl, Christian; Schneider, Felix; Yuan, Xiaohui; Ratschbacher, Lothar; Mechie, James

    2016-04-01

    It is part of the plate-tectonic paradigm that buoyant continental lithosphere subducts only in tow of a sinking oceanic plate after continent collision and that large deep (> 100 km) earthquakes occur exclusively in subducted oceanic lithosphere. Yet under the Pamir in Central Asia, far away from any (paleo-)ocean basins, continental lithosphere appears to subduct by itself and the Pamir-Hindu Kush seismic zone is one of the most active intermediate (100-300 km) depth earthquake zones globally. We show that large-scale indentation of cratonic Asia by a promontory of the Indian plate is causing subduction of continental lithosphere under the Pamir and that the Hindu Kush earthquakes are due to detachment of a narrow plate sliver. New precise earthquake hypocenters, a large number of source mechanisms and detailed receiver function sections and tomographic images allow us to distinguish an arcuate, stretched and partly torn slab of Asian lithosphere beneath the Pamir and a piece of Indian lithosphere beneath the deepest Hindu Kush earthquakes. This peculiar double subduction zone arises by contrasting modes of convergence under Pamir and Hindu Kush imposed by the different mechanical properties of the three types of lithosphere involved: We suggest that the buoyant northwestern salient of (1) Cratonic India bulldozes into (2) Cratonic Asia forcing delamination and rollback of its lithosphere. At the same time (3) India's thinned margin tears off from Cratonic India and subducts under Asia. The narrow swath of the subducted Indian continental margin forms a prominent high-velocity anomaly down to the mantle transition zone. Its uppermost section is thinned or already severed and intermediate depth earthquakes cluster at the final neck connecting it to the deeper slab. These images provide a rare glimpse of the ephemeral process of slab break-off.

  16. Mucking about : robot takes the risk out of sample collection

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, L.

    2010-05-15

    According to Directive 74 of the Alberta Energy Resources Conservation Board, oilsands mine operators must take regular samples of tailings to monitor the reduction of fluid tailings. The tailings are a mixture of water, clay, sand and residual bitumen. Soft tailings tend to have the consistency of toothpaste, often with a surface crust. Most of the sampling is currently performed by people in boats or in vehicles. However, a group of mechanical engineering students at the University of Alberta have developed a robot that can perform the risky task of taking soil samples from partially dried oil sands tailings ponds to help determine their degree of stability. The all-tailings rover can navigate on soft tailings and take measurements to characterize the deposits. The robot measures soil strength using a penetrometer, a cone-tipped probe that is pushed about a metre into the ground. The force used indicates strength of soil up to about 20 kilopascals. The all-tailings rover looks like a small dune buggy, about one metre long. It has a gas motor with a hydraulic system that actuates the drive wheels. It also has onboard microprocessor control, a navigation unit including a global positioning satellite system and other sensors to navigate on soft ground. An onboard computer plans the trajectory or takes trajectory commands that have been sent by radio. Status information can be sent by radio to a separate computer. The robot can be hooked up to a satellite phone and operated remotely. A future model will do a dynamic penetrometer test that can mimic the vibrations of heavy equipment so that operators can determine if the deposit can support a bulldozer. Another prototype might penetrate as far down as 5 metres. 1 ref., 3 figs.

  17. Herbivore-Alga Interaction Strength Influences Spatial Heterogeneity in a Kelp-Dominated Intertidal Community.

    Directory of Open Access Journals (Sweden)

    Moisés A Aguilera

    Full Text Available There is a general consensus that marine herbivores can affect algal species composition and abundance, but little empirical work exists on the role of herbivores as modifiers of the spatial structure of resource assemblages. Here, we test the consumption/bulldozing effects of the molluscan grazer Enoplochiton niger and its influence on the spatial structure of a low intertidal community dominated by the bull kelp Durvillaea antarctica and the kelp Lessonia spicata. Through field experiments conducted at a rocky intertidal shore in north-central Chile (~30°-32°S, the edge of the grazer and algae geographic distributions, we estimated the strength and variability of consumptive effects of the grazer on different functional group of algae. We also used data from abundance field surveys to evaluate spatial co-occurrence patterns of the study species. Exclusion-enclosure experiments showed that E. niger maintained primary space available by preventing algal colonization, even of large brown algae species. The grazing activity of E. niger also reduced spatial heterogeneity of the ephemeral algal species, increasing bare space availability and variability through time in similar ways to those observed for the collective effect with other grazers. Overall, our result suggests that E. niger can be considered an important modifier of the spatial structure of the large brown algae-dominated community. Effects of E. niger on resource variability seem to be directly related to its foraging patterns, large body size, and population densities, which are all relevant factors for management and conservation of the large brown algae community. Our study thus highlights the importance of considering functional roles and identity of generalist consumers on spatial structure of the entire landscape.

  18. Geomorphology of the Elwha River and its Delta: Chapter 3 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal

    Science.gov (United States)

    Warrick, Jonathan A.; Draut, Amy E.; McHenry, Michael L.; Miller, Ian M.; Magirl, Christopher S.; Beirne, Matthew M.; Stevens, Andrew Stevens; Logan, Joshua B.; Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.

    2011-01-01

    The removal of two dams on the Elwha River will introduce massive volumes of sediment to the river, and this increase in sediment supply in the river will likely modify the shapes and forms of the river and coastal landscape downstream of the dams. This chapter provides the geologic and geomorphologic background of the Olympic Peninsula and the Elwha River with emphasis on the present river and shoreline. The Elwha River watershed was formed through the uplift of the Olympic Mountains, erosion and movement of sediment throughout the watershed from glaciers, and downslope movement of sediment from gravitational and hydrologic forces. Recent alterations to the river morphology and sediment movement through the river include the two large dams slated to be removed in 2011, but also include repeated bulldozing of channel boundaries, construction and maintenance of flood plain levees, a weir and diversion channel for water supply purposes, and engineered log jams to help enhance river habitat for salmon. The shoreline of the Elwha River delta has changed in location by several kilometers during the past 14,000 years, in response to variations in the local sea-level of approximately 150 meters. Erosion of the shoreline has accelerated during the past 80 years, resulting in landward movement of the beach by more than 200 meters near the river mouth, net reduction in the area of coastal wetlands, and the development of an armored low-tide terrace of the beach consisting primarily of cobble. Changes to the river and coastal morphology during and following dam removal may be substantial, and consistent, long-term monitoring of these systems will be needed to characterize the effects of the dam removal project.

  19. Hydraulic manipulator design, analysis, and control at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned to hydraulics as a means of actuation. Hydraulics have always been the actuator of choice when designing heavy-life construction and mining equipment such as bulldozers, backhoes, and tunneling devices. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem) sophisticated modeling, analysis, and control experiments are usually needed. To support the development and deployment of new hydraulic manipulators Oak Ridge National Laboratory (ORNL) has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The hydraulics laboratory at ORNL has three different manipulators. First is a 6-Degree-of-Freedom (6-DoF), multi-planer, teleoperated, flexible controls test bed used for the development of waste tank clean-up manipulator controls, thermal studies, system characterization, and manipulator tracking. Finally, is a human amplifier test bed used for the development of an entire new class of teleoperated systems. To compliment the hardware in the hydraulics laboratory, ORNL has developed a hydraulics simulation capability including a custom package to model the hydraulic systems and manipulators for performance studies and control development. This paper outlines the history of hydraulic manipulator developments at ORNL, describes the hydraulics laboratory, discusses the use of the equipment within the laboratory, and presents some of the initial results from experiments and modeling associated with these hydraulic manipulators. Included are some of the results from the development of the human amplifier/de-amplifier concepts, the characterization of the thermal sensitivity of hydraulic systems, and end-point tracking accuracy studies. Experimental and analytical

  20. Did the emergence of animals have an impact on the carbon cycle of the ocean floor?

    Science.gov (United States)

    Meysman, Filip; Maire, Olivier; Bockelmann, Frank; van Oevelen, Dick; Glud, Ronnie

    2010-05-01

    The first animals appeared at or near the ocean floor, and paleontologists have suggested that the ensuing Cambrian explosion resulted in a regime shift in the biogeochemical functioning of the ocean floor. The newly evolved animals rapidly adopted a burrowing lifestyle, and as result, sediments became mixed and reworked, thus "bulldozing" the microbial mats that had covered the ocean floor in the Precambrian. Sedimentary redox conditions also changed, as burrow networks were flushed with oxygenated overlying water. But did the emergence of large burrowing fauna truly have an impact on the carbon cycle of the ocean? Here, we try to answer this question by looking at the present-day situation, that is, we estimate how large the impact is of large burrowing fauna on organic carbon processing in the ocean floor. We addressed this by a global synthesis and model analysis of the in situ oxygen uptake rate in marine sediments, where the oxygen uptake is used as a proxy for organic carbon mineralization. The total oxygen uptake can be split into a diffusive oxygen uptake, linked to oxygen supply by diffusion across the sediment water interface, and a faunal mediated uptake, linked to faunal respiration and bio-irrigation. Our results show that the faunal mediated contribution to the total oxygen uptake is about 20% for the global ocean floor and 45% for the global continental shelves. About 25% of this faunal mediated contribution is explained by direct respiration of macrofauna and meiofauna, the other 75% is linked to the stimulation of microbial decomposition through bio-irrigation. Overall, our analysis suggests a large imprint of benthic fauna on the sedimentary processing of organic carbon, particularly in continental shelves and coastal sediments. This then suggests that the evolution of large burrowing fauna may have had a substantial impact on the rate of mineralization and sequestration of organic matter in marine sediments.

  1. Relating rock avalanche morphology to emplacement processes

    Science.gov (United States)

    Dufresne, Anja; Prager, Christoph; Bösmeier, Annette

    2015-04-01

    The morphology, structure and sedimentological characteristics of rock avalanche deposits reflect both internal emplacement processes and external influences, such as runout path characteristics. The latter is mainly predisposed by topography, substrate types, and hydrogeological conditions. Additionally, the geological setting at the source slope controls, e.g. the spatial distribution of accumulated lithologies and hence material property-related changes in morphology, or the maximum clast size and amount of fines of different lithological units. The Holocene Tschirgant rock avalanche (Tyrol, Austria) resulted from failure of an intensely deformed carbonate rock mass on the southeast face of a 2,370-m-high mountain ridge. The initially sliding rock mass rapidly fragmented as it moved towards the floor of the Inn River valley. Part of the 200-250 x 106 m3 (Patzelt 2012) rock avalanche debris collided with and moved around an opposing bedrock ridge and flowed into the Ötz valley, reaching up to 6.3 km from source. Where the Tschirgant rock avalanche spread freely it formed longitudinal ridges aligned along motion direction as well as smaller hummocks. Encountering high topography, it left runup ridges, fallback patterns (i.e. secondary collapse), and compressional morphology (successively elevated, transverse ridges). Further evidence for the mechanical landslide behaviour is given by large volumes of mobilized valley-fill sediments (polymict gravels and sands). These sediments indicate both shearing and compressional faulting within the rock avalanche mass (forming their own morphological units through, e.g. in situ bulldozing or as distinctly different hummocky terrain), but also indicate extension of the spreading landslide mass (i.e. intercalated/injected gravels encountered mainly in morphological depressions between hummocks). Further influences on its morphology are given by the different lithological units. E.g. the transition from massive dolomite

  2. The Palestinian mammalian fauna acquired by the zoological gardens in the Gaza Strip

    Directory of Open Access Journals (Sweden)

    ABDEL FATTAH N. ABD RABOU

    2011-07-01

    Full Text Available Abd Rabou AFN. 2011. The Palestinian mammalian fauna acquired by the zoological gardens in the Gaza Strip. Nusantara Bioscience 3: 82-91. The Gaza Strip, which is an arid strip of the Palestinian land along the southeastern Mediterranean, harbors a considerable number of mammalian fauna due to its eco-geo-strategic position. Prior to 2006, the establishment of zoological gardens in the Gaza Strip was a sort of imagination due to Israeli constraints. These constraints were nurtured by the total Israeli destruction and demolition of the Rafah and Gaza private zoological gardens in 2004 and 2009 respectively, using heavy tanks and bulldozers. The establishment of many zoological gardens following the Israeli evacuation from the Gaza Strip in late 2005 encouraged wildlife trading. Hence, the current study comes to document the Palestinian mammalian faunistic species acquired by the zoological gardens in the Gaza Strip through frequent visits to Gaza zoological gardens and meetings with local people, wildlife hunters and zoo owners. A total number of 17 Palestinian mammalian faunistic species belonging to 12 families and 5 orders was encountered in the zoological gardens throughout the study period. The encountered species represent a good mix of the families and sizes of mammals generally found in other parts of Palestine. Order Carnivora represents 52.94% of the caged mammals, while the orders Rodentia, Lagomorpha, Artiodactyla and Insectivora represent 47.06%. The study documented the first sight of the Greater Egyptian Gerbil Gerbillus pyramidis in the Gaza Strip. Local hunting, tunnel trade and delivery were the lonely sources of the mammals encountered in the zoological gardens. The economic deprivation under the current Israeli blockade and the poor implementation of environmental laws and legislations concerning wildlife protection have made wildlife trading as a common practice. Finally, The author recommends to improving the management

  3. The structure and origin of Prydz Bay and MacRobertson Shelf, East Antarctica

    Science.gov (United States)

    Stagg, H. M. J.

    1985-04-01

    A marine geophysical survey in early 1982, conducted by the Australian Bureau of Mineral Resources, indicated that much of Prydz Bay is underlain by a sedimentary basin. Severe seismic multiples preclude an accurate estimate of total sediment thickness, but interpretation of the seismic and magnetic data suggest that it is probably at least 5 km. The trends of the southeast basin margin and of mild faulting and folding in the southwest indicate an overall NNE trend, roughly orthogonal to the continental margin. In the south of Prydz Bay, two series of seismic sequences are evident, separated by a mildly erosional unconformity. The lower series ranges from poorly- to well-stratified, has minor folding and faulting, and probably derives from continental and perhaps shallow marine pre-breakup sediments. The upper series is generally well-stratified, and prograded near the shelf edge; it probably represents shallow marine post-breakup sediments. The seabed is distinctly unconformable with the underlying sediments, implying both that much of the upper series sediments and some of the lower series sediments have been bulldozed off by advances of the Amery Ice Shelf, and that present sedimentation rates are very low. Possible thin moraines or tillites in the northeast part of the Prydz Bay are also attributed to these glacial advances. The continental slope and rise sedimentary section ranges from at least 3 km thick off Prydz Bay, to thin off the MacRobertson Shelf to the west, reflecting the more prolific sediment source in Prydz Bay. The deep water section includes several seismic sequences, the most distinctive being interpreted as sheet volcanics and turbidite fans. The deepest visible unconformity is locally strongly faulted and may separate the pre-breakup and post-breakup sediments. Indo-Antarctic breakup has been tentatively dated as Early Neocomian (130 Ma) and the E-W orientation of the resultant Antarctic coast invites interpretation of the Lambert Glacier

  4. An evolving research agenda for human-coastal systems

    Science.gov (United States)

    Lazarus, Eli D.; Ellis, Michael A.; Brad Murray, A.; Hall, Damon M.

    2016-03-01

    Within the broad discourses of environmental change, sustainability science, and anthropogenic Earth-surface systems, a focused body of work involves the coupled economic and physical dynamics of developed shorelines. Rapid rates of change in coastal environments, from wetlands and deltas to inlets and dune systems, help researchers recognize, observe, and investigate coupling in natural (non-human) morphodynamics and biomorphodynamics. This same intrinsic quality of fast-paced change also makes developed coastal zones exemplars of observable coupling between physical processes and human activities. In many coastal communities, beach erosion is a natural hazard with economic costs that coastal management counters through a variety of mitigation strategies, including beach replenishment, groynes, revetments, and seawalls. As cycles of erosion and mitigation iterate, coastline change and economically driven interventions become mutually linked. Emergent dynamics of two-way economic-physical coupling is a recent research discovery. Having established a strong theoretical basis, research into coupled human-coastal systems has passed its early proof-of-concept phase. This paper frames three major challenges that need resolving in order to advance theoretical and empirical treatments of human-coastal systems: (1) codifying salient individual and social behaviors of decision-making in ways that capture societal actions across a range of scales (thus engaging economics, social science, and policy disciplines); (2) quantifying anthropogenic effects on alongshore and cross-shore sediment pathways and long-term landscape evolution in coastal zones through time, including direct measurement of cumulative changes to sediment cells resulting from coastal development and management practices (e.g., construction of buildings and artificial dunes, bulldozer removal of overwash after major storms); and (3) reciprocal knowledge and data exchange between researchers in coastal

  5. Phase I Archaeological Investigation Cultural Resources Survey, Hawaii Geothermal Project, Makawao and Hana Districts, South Shore of Maui, Hawaii (DRAFT )

    Energy Technology Data Exchange (ETDEWEB)

    Erkelens, Conrad

    1994-03-01

    This report details the archaeological investigation of a 200 foot wide sample corridor extending approximately 9 miles along the southern portion of Maui within the present districts of Hana and Makawao. A total of 51 archaeological sites encompassing 233 surface features were documented. A GPS receiver was used to accurately and precisely plot locations for each of the documented sites. Analysis of the locational information suggests that archaeological sites are abundant throughout the region and only become scarce where vegetation has been bulldozed for ranching activities. At the sea-land transition points for the underwater transmission cable, both Ahihi Bay and Huakini Bay are subjected to seasonal erosion and redeposition of their boulder shorelines. The corridor at the Ahihi Bay transition point runs through the Moanakala Village Complex which is an archaeological site on the State Register of Historic Places within a State Natural Area Reserve. Numerous other potentially significant archaeological sites lie within the project corridor. It is likely that rerouting of the corridor in an attempt to avoid known sites would result in other undocumented sites located outside the sample corridor being impacted. Given the distribution of archaeological sites, there is no alternative route that can be suggested that is likely to avoid encountering sites. A total of twelve charcoal samples were obtained for potential taxon identification and radiocarbon analysis. Four of these samples were subsequently submitted for dating and species identification. Bird bone from various locations within a lava tube were collected for identification. Sediment samples for subsequent pollen analysis were obtained from within two lava tubes. With these three sources of information it is hoped that paleoenvironmental data can be recovered that will enable a better understanding of the setting for Hawaiian habitation of the area. A small test unit was excavated at one habitation site

  6. 两种小型二冲程汽油机的配气方式及特点%Valve Means and Features of Two Kinds of Small Two-stroke Gasoline Engine

    Institute of Scientific and Technical Information of China (English)

    刘长生

    2011-01-01

    As Small two-stroke gasoline engine has the advantages of small size and easy to move, easy start (especially in cold winter) , easy maintenance and the price is low, it is used not only in a small hand-held e-quipment, but also used as the starter for large diesel engines of some construction machinery (such as bulldozers, loaders etc. ). However, for some reasons, old-fashioned small two-stroke gasoline engines whose intake is controlled by piston skirt are introduced in domestic published works, teaching materials and papers, more than the more advanced small two -stroke gasoline engine in international that's of mass production in domestic from 80of the last century and the intake is controlled by crankcase. In this article, the valve means and features of these two kinds of two-stroke gasoline engine are presented and compared. The results show that intake controlled by crankcase is the development direction of small two-stroke gasoline engine of China.%小型二冲程汽油机由于体积小、移动方便,再加上其易于起动(尤其在寒冷的冬天)、维护方便且价格较低,不但在小型手持机具中,而且在一些工程机械中(如推土机、装载机等)也大量用作其大型柴油机的起动机.然而,由于一些原因,我国目前出版的著作、教材以及发表的论文中,介绍的基本都是比较老式的活塞裙控制进气的小型二冲程汽油机,很少提及目前国际上较为先进,国内从上世纪80年代已成批生产的曲轴箱控制进气的小型二冲程汽油机.本文将这两种二冲程汽油机的配气方式及特点做了比较详细地介绍和对比.说明,曲轴箱控制进气的二冲程汽油机已是我国小型二冲程汽油机的发展方向.

  7. The detectability of archaeological structures beneath the soil using the ground penetrating radar technique

    Science.gov (United States)

    Ferrara, C.; Barone, P. M.; Pajewski, L.; Pettinelli, E.; Rossi, G.

    2012-04-01

    The traditional excavation tools applied to Archaeology (i.e. trowels, shovels, bulldozers, etc.) produce, generally, a fast and invasive reconstruction of the ancient past. The geophysical instruments, instead, seem to go in the opposite direction giving, rapidly and non-destructively, geo-archaeological information. Moreover, the economic aspect should not be underestimated: where the former invest a lot of money in order to carry out an excavation or restoration, the latter spend much less to manage a geophysical survey, locating precisely the targets. Survey information gathered using non-invasive methods contributes to the creation of site strategies, conservation, preservation and, if necessary, accurate location of excavation and restoration units, without destructive testing methods, also in well-known archaeological sites [1]-[3]. In particular, Ground Penetrating Radar (GPR) has, recently, become the most important physical technique in archaeological investigations, allowing the detection of targets with both very high vertical and horizontal resolution, and has been successfully applied both to archaeological and diagnostic purposes in historical and monumental sites [4]. GPR configuration, antenna frequency and survey modality can be different, depending on the scope of the measurements, the nature of the site or the type of targets. Two-dimensional (2D) time/depth slices and radargrams should be generated and integrated with information obtained from other buried or similar artifacts to provide age, structure and context of the surveyed sites. In the present work, we present three case-histories on well-known Roman archaeological sites in Rome, in which GPR technique has been successfully used. To obtain 2D maps of the explored area, a bistatic GPR (250MHz and 500MHz antennas) was applied, acquiring data along several parallel profiles. The GPR results reveal the presence of similar circular anomalies in all the investigated archaeological sites. In

  8. Short term recovery of soil physical, chemical, micro- and mesobiological functions in a new vineyard under organic farming

    Science.gov (United States)

    Costantini, E. A. C.; Agnelli, A. E.; Fabiani, A.; Gagnarli, E.; Mocali, S.; Priori, S.; Simoni, S.; Valboa, G.

    2014-12-01

    Deep earthwork activities carried out before vineyard plantation can severely upset soil profile properties. As a result, soil features in the root environment are often much more similar to those of the underlying substratum than those of the original profile. The time needed to recover the original soil functions is ecologically relevant and may strongly affect vine phenology and grape yield, particularly under organic viticulture. The general aim of this work was to investigate soil resilience after vineyard pre-planting earthworks. In particular, an old and a new vineyard, established on the same soil type, were compared over a five year period for soil chemical, physical, micro and mesobiological properties. The investigated vineyards (Vitis vinifera L., cv. Sangiovese) were located in the Chianti Classico district (Central Italy), on stony and calcareous soils and were not irrigated. The older vineyard was planted in 2000, after slope reshaping by bulldozing and back hoe ploughing down to about 0.8-1.0 m. The new vineyard was planted in 2011, after equivalent earthwork practices carried out in the summer of 2009. Both vineyards were organically managed and fertilized only with compost every autumn (1000 kg ha-1 per year). The new vineyard was cultivated by periodic tillage, while the old vineyard was managed with alternating grass-covered and tilled inter-rows. Soil samples were collected at 0-15 cm depth from the same plots of the new and old vineyards, during the springtime from 2010 to 2014. The old vineyard was sampled in both the tilled and the grass-covered swaths. According to the results from physical and chemical analyses, the new vineyard, during the whole 2010-2014 period, showed lower TOC, N, C/N and EC values, along with higher silt and total CaCO3 contents than the old vineyard, suggesting still evolving equilibrium conditions. The microarthropod analysis showed significantly different abundances and communities' structures, in relation to both

  9. The physical processes of seabed disturbance during iceberg grounding and scouring

    Science.gov (United States)

    Woodworth-Lynas, C. M. T.; Josenhans, H. W.; Barrie, J. V.; Lewis, C. F. M.; Parrott, D. R.

    1991-08-01

    Icebergs drifting in ocean currents over the Labrador continental shelf may contact and move through seabed sediments to create characteristically curvilinear features, commonly referred to as scours, which average 1-2 m in depth and about 30-40 m in width. Such scours may continue for several hundreds of metres or several kilometres. The period of seabed interaction may last from a few minutes to several months and results in modification of both the seabed sediments and the iceberg keel. When observed from submersible soon after their formation, scours exhibit morphological characteristics not seen in old, degraded scours. The scour trough, between two berm ridges, is generally flat-bottomed but is characterized by the presence of ridge-and-groove microtopography, with amplitudes up to 0.3 m developed parallel to the scour axis. These features are formed at the trailing edge of the keel by clastic material embedded in the ice and by open fissures in the ice. In places along the inner berm margins, ridges and grooves may be developed at an angle to the scour axis, reflecting lateral displacement of material towards the berm as the iceberg moves forward. Voids up to 1 m deep and 2 m wide occasionally truncate the ridges and grooves. Voids are formed following the dissolution of small (a few m 3) masses of debris-laden ice that are mechanically broken off from the base of the keel and pressed into the seabed by the scouring iceberg. Initially low areas within the scour trough may preserve seafloor that has not been affected by ice-seabed interaction. In these regions deposition of bulldozed sediment from the surcharge at the leading edge of the keel may partially fill the narrow spaces beneath the keel in areas of initially low seabed elevation. Scour berms consist of in situ fractured but intact blocks of material on the inner flanks, and disarticulated blocks 1-2 m high along the berm crest. The outer berm slopes generally consist of pieces of larger blocks

  10. Paleoseismology in Venezuela: Objectives, methods, applications, limitations and perspectives

    Science.gov (United States)

    Audemard M., Franck A.

    2005-10-01

    The privileged location of Venezuela along an active interplate deformation belt, despite of being a "so-called" developing country, has led to a long paleoseismic tradition as attested by 45 trench assessments since 1968. Since then, a first 2-trench study was carried out by the American Woodward-Clyde company across the Oca fault at Sinamaica. Since 1980, all further paleoseismic studies have been performed by FUNVISIS and the Uribante-Caparo hydroelectric project (southern Mérida Andes) became their first assessment where 22 huge trenches were bulldozer-dug. Except for these Compañía Anónima de Administración y Fomento Eléctrico (CADAFE) financed trenches and two others, all other assessments were for Petróleos de Venezuela S. A. -PDVSA-. In this paper, geographic and geologic factors, as well as logistic limitations, conditioning success in paleoseismic studies by trenching, shall be discussed based on the Venezuelan experience developed over the years. The scientific contribution of this approach refer to: confirmation of Holocene fault activity, slip-per-event and average slip rate of a given fault (or segment), seismic potential (repeat of maximum credible earthquakes) of known faults, fault segmentation, fault interaction as consequence of stress loading by stick-slip on contiguous faults, time-space distribution of seismic activity along a given tectonic feature, seismotectonic association of historical earthquakes and landscape evolution on the short term and its implications on the long-term evolution (poorly discussed since this is really part of the field of Neotectonics). In recent years (since 1999), a new approach has been introduced in Venezuela consisting in complementing the seismic history derived from trenching studies with the evaluation of seismically induced perturbations in the continuous Quaternary sedimentary record of (either active or fossil) lakes. The future of this discipline in Venezuela heads to more trenching and lake

  11. Analysis of recurring sinking events of armored tracked vehicles along dirt roads in the agricultural periphery of the Gaza Strip

    Science.gov (United States)

    Roskin, Joel

    2013-04-01

    The second (Al-Aqsa) intifada (Arab violent uprising) which erupted across Israel in 2000 eventually led the Israel Defense Forces to deploy armored tracked vehicles (ATVs) (tanks, armored personal carriers, and D-9 bulldozers) within Israel's agricultural periphery of the Gaza Strip, following daily attempts by Arab terrorists and guerillas to penetrate Israel. Combat movement of the ATVs was mainly concentrated to dirt roads, between agricultural fields, wherever possible. As a result of semi-arid Mediterranean (climate) winter rains, annually averaging 250 - 350 mm, it was reported that ATVs often sank in muddy terrain. This study investigated what caused ATVs to sink. The main data collected concerning the types of vehicles that sank related to: land-use characteristics, soil type, and daily rainfall. Interviews with commanders were also conducted for additional details. Between the fall and spring, surveys and weekly / bi-weekly field soil cone penetrometer tests were conducted at ten sites with different pedological and land-use characteristics. The loess soils, especially in agricultural fields, were generally found to be conducive to ATV traffic, even shortly after rainstorms of 10-30 mm. However, following several rainfall events exceeding 10 mm, ATVs and tanks regularly sank into local topographic depressions in the undulating landscape. These consisted of short segments of dirt roads where runoff and suspended sediment collected. After the early rains in late fall, tank ruts fossilize and become conduits of concentrated runoff and fine particles eroded by ATV activity during the summer months. Tank track ruts that formed in mud, compacted the soil, drastically altered drainage patterns by directing significant surface flow, and suspended sediment into these depressions, creating "tank-traps" whose trafficability ranged from "untrafficable" to "trafficable with constraints." This study shows that intense, routine, defensive military activity operated

  12. Bacterial Viability within Dental Calculus: An Untrodden, Inquisitive Clinico-Patho- Microbiological Research

    Science.gov (United States)

    Jain, PK; Kumra, Madhumani; Rehani, Shweta; Mathias, Yulia; Gupta, Ramakant; Mehendiratta, Monica; Chander, Anil

    2016-01-01

    Introduction Chronic inflammatory periodontal diseases i.e. gingivitis and periodontitis are one of the most common afflictions faced by human beings. Dental plaque, which is a pool of pathogenic microorganisms, remains to be current mainstay in etiopathogenesis. Dental calculus, which is a mineralized product of this plaque remains ignored and is considered merely as an ash heap of minor significance. However, the intriguing array in disease etiopathogenesis bulldozed researchers to suspect the role of calculus in disease chrysalis but still the viability of bacteria inside calculus and thus its pathogenicity remains an intricacy; the answer to which lies in the Pandora’s Box. Aim The present study was undertaken to investigate the viability of bacteria within dental calculus along with their identification. Also, to classify dental calculus on the basis of mineralization and to observe the variation of viable microflora found in dental calculus with the extent of mineralization and disease severity. Materials and Methods A total of 60 samples were obtained, by harvesting two samples of supragingival calculus from each patient having chronic inflammatory periodontal disease. These samples were divided into two groups (Group A and Group B). Samples of Group A were kept non-irradiated and samples of Group B were exposed to UV radiation. The samples were categorized into less, moderately and highly mineralized according to the force required for crushing them. All the crushed calculus samples were then divided into three parts. These were used for dark-field microscopy, gram staining and bacterial cultures. Bacterial identification of the cultures obtained was also carried out by performing various biochemical assays. Results The present study revealed the presence of motile spirochaetes within the samples under dark-field microscope. Gram staining revealed presence of numerous gram positive cocci and gram negative bacilli. Bacterial cultures showed growth of

  13. Assessment and evaluation of noise controls on roof bolting equipment and a method for predicting sound pressure levels in underground coal mining

    Science.gov (United States)

    Matetic, Rudy J.

    Over-exposure to noise remains a widespread and serious health hazard in the U.S. mining industries despite 25 years of regulation. Every day, 80% of the nation's miners go to work in an environment where the time weighted average (TWA) noise level exceeds 85 dBA and more than 25% of the miners are exposed to a TWA noise level that exceeds 90 dBA, the permissible exposure limit (PEL). Additionally, MSHA coal noise sample data collected from 2000 to 2002 show that 65% of the equipment whose operators exceeded 100% noise dosage comprise only seven different types of machines; auger miners, bulldozers, continuous miners, front end loaders, roof bolters, shuttle cars (electric), and trucks. In addition, the MSHA data indicate that the roof bolter is third among all the equipment and second among equipment in underground coal whose operators exceed 100% dosage. A research program was implemented to: (1) determine, characterize and to measure sound power levels radiated by a roof bolting machine during differing drilling configurations (thrust, rotational speed, penetration rate, etc.) and utilizing differing types of drilling methods in high compressive strength rock media (>20,000 psi). The research approach characterized the sound power level results from laboratory testing and provided the mining industry with empirical data relative to utilizing differing noise control technologies (drilling configurations and types of drilling methods) in reducing sound power level emissions on a roof bolting machine; (2) distinguish and correlate the empirical data into one, statistically valid, equation, in which, provided the mining industry with a tool to predict overall sound power levels of a roof bolting machine given any type of drilling configuration and drilling method utilized in industry; (3) provided the mining industry with several approaches to predict or determine sound pressure levels in an underground coal mine utilizing laboratory test results from a roof bolting

  14. New 3D bathymetry and sediment distribution in Lake Vostok: Implication for pre-glacial origin and numerical modeling of the internal processes within the lake

    Science.gov (United States)

    Filina, Irina Y.; Blankenship, Donald D.; Thoma, Malte; Lukin, Valery V.; Masolov, Valery N.; Sen, Mrinal K.

    2008-11-01

    A new distribution of water and unconsolidated sediments in subglacial Lake Vostok, East Antarctica was developed via inversion of airborne gravity data constrained by 60 seismic soundings. A model was developed for host rock with a density of 2550 kg/m 3 that was inferred from prior 2D modeling. Our 3D bathymetry model of Lake Vostok corresponds better with seismic data (RMS of 125 m) than two previous models based on the same gravity dataset. The good match in both water and sediment thicknesses between the gravity model and seismic measurements confirms two major facts about Lake Vostok: (1) the lake is hosted by sedimentary rocks, and (2) the bottom of the lake is covered with a layer of unconsolidated sediments that does not exceed 300 m in the southern basin and thickens almost to 400 m in the northern basin. Our new bathymetry model suggests much shallower water thicknesses (up to twice the previous estimates) in the middle and northern parts of the lake, while the water layer is thicker in the southern basin. Numerical modeling of the internal processes in the lake reveals the relevance of our new bathymetry model to the basal mass balance. A significant decrease in transport is observed in the shallower northern basin, as well as a decrease of 33% in the turbulent kinetic energy. However, only minor differences were observed in the distribution of the calculated freezing and melting zones compared to previous models. Estimates for the sedimentation rates for six possible mechanisms were made. Possible sedimentation mechanisms are: (1) fluvial and periglacial, i.e. those that are active prior to the establishment of a large subglacial lake; (2) deposition due to overlying ice sheet, including melting out of the ice, as well as bulldozering by the overriding ice; and (3) suspended sediments from subglacial water flow including those deposited by periodical subglacial outbursts. The estimates for these mechanisms show that unconsolidated sediments of the

  15. 履带机器人通用地面力学模型分析与底盘设计%A universal terramechanics model and the chassis design of a tracked robot

    Institute of Scientific and Technical Information of China (English)

    李雨潭; 朱华; 高志军; 程新景

    2015-01-01

    为了解决如何选取最优的履带机器人底盘相关参数的问题,创建一个包含履带底盘相关参数的通用履带机器人地面力学模型. 选取在软地面进行转弯的履带机器人作为物理模型进行数学建模,在建模过程中,考虑履带推土阻力与地面摩擦力,并引入打滑速度,最终得到了履带转弯过程中所受阻力矩的数学模型. 根据正在设计的履带机器人以及其工作环境路面的相关参数进行优化设计,得到了最优的履带宽度、接地长度与两条履带的间距. 最后,根据所得到的结果进行了样机的试制与试验,所得结果与理论计算结果相接近. 结果表明,所创建的履带机器人通用地面力学模型在进行机器人底盘设计时具有一定的理论指导意义.%In order to solve the problem of selecting the optimal parameters of the tracked robot chassis, a universal terramechanics model of tracked robot with related parameters was created.The tracked robot turning in the soft ground was used as the physical model of the mathematical modeling.In the process of modeling, considering the bulldozing resistance and the ground friction, by introducing the sliding speed, the resistance moment mathematical model of the turning process was obtained.According to the parameters of the tracked robot being designed and the corresponding pavement parameters, the optimal track width, the length of track on the ground and the distance be-tween two tracks of the coal mine rescue robot were got.Finally, a trial of the prototype was carried out, and the test results were close to the theoretical calculation.The result proves that the universal terramechanics model has certain theoretical guidance meaning in the design of the robot chassis.

  16. 履带机器人通用地面力学模型分析与底盘设计%A universal terramechanics model and the chassis design of a tracked robot

    Institute of Scientific and Technical Information of China (English)

    李雨潭; 朱华; 高志军; 程新景

    2015-01-01

    为了解决如何选取最优的履带机器人底盘相关参数的问题,创建一个包含履带底盘相关参数的通用履带机器人地面力学模型。选取在软地面进行转弯的履带机器人作为物理模型进行数学建模,在建模过程中,考虑履带推土阻力与地面摩擦力,并引入打滑速度,最终得到了履带转弯过程中所受阻力矩的数学模型。根据正在设计的履带机器人以及其工作环境路面的相关参数进行优化设计,得到了最优的履带宽度、接地长度与两条履带的间距。最后,根据所得到的结果进行了样机的试制与试验,所得结果与理论计算结果相接近。结果表明,所创建的履带机器人通用地面力学模型在进行机器人底盘设计时具有一定的理论指导意义。%In order to solve the problem of selecting the optimal parameters of the tracked robot chassis, a universal terramechanics model of tracked robot with related parameters was created. The tracked robot turning in the soft ground was used as the physical model of the mathematical modeling. In the process of modeling, considering the bulldozing resistance and the ground friction, by introducing the sliding speed, the resistance moment mathematical model of the turning process was obtained. According to the parameters of the tracked robot being designed and the corresponding pavement parameters, the optimal track width, the length of track on the ground and the distance be⁃tween two tracks of the coal mine rescue robot were got. Finally, a trial of the prototype was carried out, and the test results were close to the theoretical calculation. The result proves that the universal terramechanics model has certain theoretical guidance meaning in the design of the robot chassis.

  17. Experimental constraints on the rheology and mechanical properties of lava erupted in the Holuhraun area during the 2014 rifting event at Bárðarbunga, Iceland

    Science.gov (United States)

    Lavallee, Yan; Kendrick, Jackie; Wall, Richard; von Aulock, Felix; Kennedy, Ben; Sigmundsson, Freysteinn

    2015-04-01

    A fissure eruption began at Holuhraun on 16 August 2014, following magma drainage from the Bárðarbunga volcanic system (Iceland). Extrusion initiated as fire fountaining along a segment of the fracture and rapidly localised to a series of small, aligned cones containing a lava lake that over spilled at both ends, feeding a large lava field. The lava composition and flow behaviour put some constraints on its rheology and mechanical properties. The lava erupted is a nearly aphyric basalt containing approximately 2-3% plagioclase with traces of olivine and pyroxene in a quenched groundmass composed of glass and 20-25% microlites. The transition from fire fountaining to lava flow leads to lava with variable vesicularities; pyroclasts expelled during fire fountaining reach up to 80% vesicles whilst the lava contain up to 45% vesicles. Textures in the lava vary from a'a to slabby pahoehoe, and flow thicknesses from several meters to few centimetres. Tension gashes, crease structures and shear zones in the upper lava carapace reveal the importance of both compressive and tensional stresses. In addition, occasional frictional marks at the base of the lava flow as well as bulldozing of sediments along the flow hint at the importance of frictional properties of the rocks during lava flow. Flow properties, textures and failure modes are strongly dependent on the material properties as well as the local conditions of stress and temperature. Here we expand our field observation with preliminary high-temperature experimental data on the rheological and mechanical properties of the erupted lava. Dilatometric measurements are used to constrain the thermal expansion coefficient of the lava important to constrain the dynamics of cooling of the flow. Micropenetration is further employed to determine the viscosity of the melt at super-liquidus temperature, which is compared to the temperature-dependence of viscosity as constrained by geochemistry. Lastly, uniaxial compression and

  18. CO2lonialismo y geografías de esperanza

    Directory of Open Access Journals (Sweden)

    Julianne Hazlewood

    2010-05-01

    Full Text Available Este artículo nos lleva, más allá de la crisis económica, hacia el calentamiento global y nos advierte de un problema profundo: un defecto estructural en el capitalismo. Vinculando teóricamente cambio climático, colonialismo y capitalismo, se estudia a San Lorenzo como una frontera agrícola en la que el CO2lonialismo se despliega a través del cultivo de palma aceitera y la producción de agrocombustibles. Esta investigación resalta las prácticas culturales y espaciales a través de las cuales las comunidades afro-ecuatoriana, chachi, y awá construyen y sostienen “geografías de esperanza” en medio de bosques talados, ríos envenenados y conflictos sociales. A través de la exposición detallada de la deuda ecológica del Norte global con el Sur global, este artículo condena discursos y acciones que se enfocan en el mejoramiento del clima económico mientras arrasan los bosques húmedos, las prácticas culturales de vida de las comunidades y las soluciones reales al cambio climático.This paper takes us beyond the present economic crisis to where global warming warns of a much more profound problem: a structural flaw in capitalism. Theoretically linking relations between climate change, colonialism, and capitalism, San Lorenzo is investigated as an agricultural frontier where “CO2lonialism” unfolds in African oil palm cultivation and agrofuel production. This research highlights the cultural and spatial practices through which Afro-Ecuadorian, Chachi, and Awá communities construct and sustain “geographies of hope” amid landscapes of fallen forests, poisoned rivers and social conflicts. Expounding on the ecological debt of the Global North to the Global South, this paper condemns discourses and actions that solely focus on improving the economic climate while bulldozing rainforests, livelihoods, and real solutions to climate change.

  19. MaMiCo: Software design for parallel molecular-continuum flow simulations

    KAUST Repository

    Neumann, Philipp

    2015-11-19

    The macro-micro-coupling tool (MaMiCo) was developed to ease the development of and modularize molecular-continuum simulations, retaining sequential and parallel performance. We demonstrate the functionality and performance of MaMiCo by coupling the spatially adaptive Lattice Boltzmann framework waLBerla with four molecular dynamics (MD) codes: the light-weight Lennard-Jones-based implementation SimpleMD, the node-level optimized software ls1 mardyn, and the community codes ESPResSo and LAMMPS. We detail interface implementations to connect each solver with MaMiCo. The coupling for each waLBerla-MD setup is validated in three-dimensional channel flow simulations which are solved by means of a state-based coupling method. We provide sequential and strong scaling measurements for the four molecular-continuum simulations. The overhead of MaMiCo is found to come at 10%-20% of the total (MD) runtime. The measurements further show that scalability of the hybrid simulations is reached on up to 500 Intel SandyBridge, and more than 1000 AMD Bulldozer compute cores. Program summary: Program title: MaMiCo. Catalogue identifier: AEYW_v1_0. Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEYW_v1_0.html Program obtainable from: CPC Program Library, Queen\\'s University, Belfast, N. Ireland. Licensing provisions: BSD License. No. of lines in distributed program, including test data, etc.: 67905. No. of bytes in distributed program, including test data, etc.: 1757334. Distribution format: tar.gz. Programming language: C, C++II. Computer: Standard PCs, compute clusters. Operating system: Unix/Linux. RAM: Test cases consume ca. 30-50 MB. Classification: 7.7. External routines: Scons (http:www.scons.org), ESPResSo, LAMMPS, ls1 mardyn, waLBerla. Nature of problem: Coupled molecular-continuum simulation for multi-resolution fluid dynamics: parts of the domain are resolved by molecular dynamics whereas large parts are covered by a CFD solver, e.g. a lattice Boltzmann automaton

  20. Numerical Modelling by FLAC on Coal Fires in North China

    Science.gov (United States)

    Gusat, D.; Drebenstedt, C.

    2009-04-01

    coal mine with the backfill. A smaller fires can also be handled by taking out burning coal by bulldozing techniques described above are applicable to small fires, but they do not work well in extinction of large coal fires. References [1] http://www.coalfire.caf.dlr.de [2] Schalke, H.J.W.G.; Rosema, A.; Van Genderen, J.L. (1993): Environmental monitoring of coal fires in North China. Project Identification Mission Report. Report Remote Sensing Programme Board, Derft, the Netherlands. [3] Zhang, X.; Kroonenberg, S. B.; De Boer, C. B. (2004): Dating of coal fires in Xinjiang, north-west China. Terra Nova. Band 16, No 2, S. 68-74. DOI: 10.1111/j.1365-3121.2004.00532.x [4] Deng Jun, Hou Shuang, Li Huirong, e.t.c (2006): Oxidation Mechanism at Initial Stage of a Simulated Coal Molecule with -CH2O-[J]. Journal of Changchun University of Science and Technology, 29(2), P. 84-87. [5] Deng, Jun (2008): Presentation. Chinese Researches and Practical Experiences on Controlling Underground Coal Fires. The 2nd Australia-China Symposium on Science, Technology and Education. 15-18 October 2008, Courtyard Marriott, Surfers Paradise Beach, Gold Coast, Queensland, Australia. [6] Itasca (2003): FLAC, Fast Lagrangian Analysis of Continua. Itasca Consultants Group, Inc., Minneapolis.

  1. Impact of land-levelling measures on gully and soil erosion analysed by rainfall simulation and UAV remote sensing data in the Souss Basin, Morocco

    Science.gov (United States)

    Peter, Klaus Daniel; d'Oleire-Oltmanns, Sebastian; Ries, Johannes B.; Marzolff, Irene; Hssaine, Ali Ait

    2013-04-01

    respectively) on levelled study sites compared to undisturbed sites. Consequently, the most active gullies with the highest gully erosion rates are also found on levelled test sites. For one of the test sites it can be stated that gully erosion accounts for up to 95 % of the total soil loss of the catchment. The surface area serves only as runoff source. The infilling of old gully systems is mostly done by transferring large amounts of soil material from the hillslopes into the channels. This may lower the soil surface in a gully catchment by about 10 cm on average. Runoff water often follows the old pathways. Thus, infilled gully systems tend to be re-activated very fast. The freshly provided soil material can easily be eroded. Additionally, the bulldozer furrows lead to parallel drainage network patterns in the development of new side gullies.

  2. Short-term recovery of soil physical, chemical, micro- and mesobiological functions in a new vineyard under organic farming

    Science.gov (United States)

    Costantini, E. A. C.; Agnelli, A. E.; Fabiani, A.; Gagnarli, E.; Mocali, S.; Priori, S.; Simoni, S.; Valboa, G.

    2015-06-01

    Deep earthwork activities carried out before vineyard plantation can severely affect soil profile properties. As a result, soil features in the root environment are often much more similar to those of the underlying substratum than those of the original profile. The time needed to recover the original soil functions is ecologically relevant and may strongly affect vine phenology and grape yield, particularly under organic viticulture. The general aim of this work was to investigate soil resilience after vineyard pre-planting earthworks. In particular, an old and a new vineyard, established on the same soil type, were compared over a 5-year period for soil chemical, physical, micro- and mesobiological properties. The investigated vineyards (Vitis vinifera L., cv. Sangiovese) were located in the Chianti Classico district (central Italy), on stony and calcareous soils, and were not irrigated. The older vineyard was planted in 2000, after slope reshaping by bulldozing and back-hoe ploughing down to about 0.8-1.0 m. The new vineyard was planted in 2011, after equivalent earthwork practices carried out in the summer of 2009. Both vineyards were organically managed, and they were fertilized with compost only every autumn (1000 kg ha-1 per year). The new vineyard was cultivated by periodic tillage, while the old vineyard was managed with alternating grass-covered and tilled inter-rows. Soil samples were collected at 0-15 cm depth from fixed locations in each vineyard every spring from 2010 to 2014. The old vineyard was sampled in both tilled and grass-covered inter-rows. According to the results from physical and chemical analyses, the new vineyard, during the whole 2010-2014 period, showed lower total organic carbon, total nitrogen, carbon to nitrogen ratio and electrical conductivity, along with higher silt and total CaCO3 contents than the old vineyard, suggesting still-evolving equilibrium conditions. The microarthropod analysis showed significantly different

  3. Nabarlek Traditional Owners' perspective on the current state of revegetation

    International Nuclear Information System (INIS)

    , which was then disposed through a tender process which in retrospect must be considered lacking in compulsion. But this is a more or less tractable matter compared to the revegetation strategy. Traditional Owners are of the view that the solution is much simpler than the re-establishment of vegetation on highly disturbed ground - essentially as simple as digging a pit and bulldozing the rubbish in. The NLC has stated that the success or failure of the present revegetation effort has not been satisfactorily determined. It is most unfortunate that the original operators of the minesite were not directly involved in the rehabilitation effort as this would have ensured a more continuous presence on the ground, and some of the apparent problems might not have arisen To Traditional Owners this transferral of responsibility is most unsatisfactory, the process off encumbrance has no ready counterpart, lines of responsibility relating to country are onerous and compelling and it confirms their perception of the inherent weakness of Western law. In their view, the responsible party is the company which conducted the mining. But in the end, it is a valid component of the Deed to which the NLC is party on their behalf, and a usual feature of commercial agreements. However, it is something that they will no doubt adjust to

  4. Structural, sedimentary and igneous evidence for the genesis and emplacement of the rifted continental margin of the Southern Neotethys, SE Turkey

    Science.gov (United States)

    Robertson, Alastair; Parlak, Osman; Dumitrica, Paulian; Tasli, Kemal; Yıldırım, Nail

    2014-05-01

    depleted mantle harzburgite, layered and massive gabbro, diabase and basaltic extrusives, are interleaved with the volcanic-sedimentary units to form a tectonic slice complex. In our working hypothesis, the Koçali Complex preserves the Late Triassic distal rifted margin of the Arabian continent. During Late Cretaceous accretion, crust that originally formed within the continent-ocean transition zone was preferentially preserved (proximal rifted margin crust is not exposed). The Koçali Complex accreted during Late Cretaceous northwards subduction, whereas MORB-type crust subducted. During subduction against the backstop (Koçali ophiolite), the sedimentary sequence on the incoming plate appears to have detached (delaminated) into a lower part (Triassic-Jurassic) that was sliced, folded and over-ridden, and an upper part that was bulldozed continentwards. Two scenarios are considered: 1. Two different successions are partially preserved, a relatively proximal slope/base-of-slope sequence (Karadat Complex) and a more distal volcanic-sedimentary sequence (Koçali Complex), with only parts of both original successions now being preserved. 2. The stratigraphically higher, Cretaceous levels of the Koçali volcanic-sedimentary sequence are now represented by the Karadut Complex. In this case, the Karadut Complex was emplaced beneath the Koçali Complex by out-sequence thrusting or re-thrusting. In either scenario, ophiolitic rocks, including sheared serpentinite and Mesozoic deep-sea pelagic/redeposited sediments locally advanced furthest to form the southernmost front of the allochthon (~Besni olistrostrome). The various allochthonous units were emplaced, subaerially exposed and partially eroded during the Maastrichtian, giving a precise timing for the emplacement of the S Neotethyan allochthonous units.

  5. Microrover Nanokhod enhancing the scientific output of the ExoMars Lander

    Science.gov (United States)

    Klinkner, Sabine; Bernhardt, Bodo; Henkel, Hartmut; Rodionov, Daniel; Klingelhoefer, Goestar

    pressure. The sinkage is minimised reducing the bulldozing effect and increasing the traction. The central Payload Cabine has 2 (Degree of Freedom) DOF, allowing inherently robust deployment and precise payload positioning. The two drives for lifting and rotating the Payload Cabine (PLC) provides a robust and repetitive accuracy for a congruent positioning of all payload instruments on the same sample. Furthermore the PLC drives can be used for climbing and overcoming obstacles. The latest developments on the Nanokhod rover have prepared the concept for a mission scenario on the Mercury surface. The mechanical design of the Nanokhod rover was developed from a conceptual stage to an engineering model which is able to withstand the demanding conditions of the Mercury mission such as: Surface temperature of -180(°) °C, significant mass restrictions, limited power and energy supply, operational surface covered with fine dust, shock loads of 200g for 20ms and high Vacuum. With the building and testing of the engineering model the concept achieved a Technical Readiness Level (TRL) of 5 to 6, and solutions were found for a set of requirements with a high complexity. With these design requirements exceeding most mission conditions of the ExoMars lander, the current design is well-prepared for the Mars scenario.

  6. Short term recovery of soil biological functions in a new vineyard cultivated in organic farming

    Science.gov (United States)

    Costantini, Edoardo; Agnelli, Alessandro; Fabiani, Arturo; Gagnarli, Elena; Mocali, Stefano; Priori, Simone; Simoni, Sauro; Valboa, Giuseppe

    2014-05-01

    Deep earthwork activities carried out before vineyard plantation completely upset soil profile and characteristics. The resulting soil features are often much more similar to the underlying substratum than original soil profile. The time needed to recover soil functions is ecologically relevant and affects vine phenology and grape yield, particularly in organic viticulture. The general aim of this research work was to investigate the time needed to recover soil functions after the earthworks made before vine plantation. This study compared for a four years period physical and chemical properties, microbial and mesofauna communities, in new and old vineyards, cultivated on the same soil type. The experiment was conducted in a farm of the Chianti Classico district (Central Italy), on hills of high altitude (400-500 m a.s.l.) on clayey-calcareous flysches, with stony and calcareous soils (Haplic Cambisol (Calcaric, Skeletic)). The reference vine cultivar was Sangiovese. The older vineyard was planted in 2000, after slope reshaping by bulldozing and back hoe ploughing down to about 0.8-1.0 m. The new vineyard was planted in 2011 after an equivalent earthwork carried out in the summer of 2009. Both vineyards were organically managed and only compost at the rate of 1,000 kg ha-1 -a was added every year. The new vineyard was periodically cultivated by mechanical tillage, while the older only at alternate rows. Soil samples from the first 15 cm depth were collected in 4 replicates in the younger as well as in the older vineyard during the springtime of 2010-2013; in the older vineyard, two samples were from the periodically cultivated swaths and two under permanent grass cover. Samples were analysed for physical (particle size, field capacity, wilting point), chemical (pH, electrical conductivity, lime, active lime, organic carbon, total nitrogen), microbiological (soil respiration, microbial biomass, DGGE), and mesofauna features (abundance, taxa richness, BSQ index and

  7. Unplanned roads impacts assessment in Phewa Lake watershed, Western region, Nepal

    Science.gov (United States)

    Leibundgut, Geoffroy; Sudmeier-Rieux, Karen; Devkota, Sanjaya; Jaboyedoff, Michel; Penna, Ivanna; Adhikari, Anu; Khanal, Rajendra

    2015-04-01

    This work describes current research being conducted in the Phewa Lake watershed, near Pokhara in Nepal's Siwaliks/Middle hills, a moist sub-tropical zone with the highest amount of annual rainfall in Nepal (4,500 - 5,000 mm). The watershed lithology is mainly siltstone, sandstones and intensively weathered rocks, highly prone to erosion and shallow landslides (Agrawala et al., 2003). The main purpose of this study is to focus on the impact of unplanned earthen road construction in the Phewa Lake watershed as part of land use changes over 30 years in one of Nepal's most touristic regions. Over the past three decades, the road network has expanded exponentially and a majority of rural earthen roads are often funded by communities themselves, with some government subsidies. They are usually constructed using a local bulldozer contractor with no technical or geological expertise increasing erosion processes, slope instabilities risk and impacts to settlements, forests, water sources, agriculture lands, and infrastructure. Moreover, these human-induced phenomena are being compounded by increasingly intense monsoon rains, likely due to climate change (Petley, 2010). Research methods were interdisciplinary and based on a combination of remote sensing, field observations and discussions with community members. The study compared 30 year-old aerial photos with current high resolution satellite images to correlate changes in land use with erosion and slope instabilities. Secondly, most of the watershed's roads were surveyed in order to inventory and quantify slope instabilities and soil loss events. Using a failure-characteristics grid, their main features were measured (location, size, type and extension of damage areas, etc.) and a GIS data base was created. We then estimated economic impacts of these events in terms of agriculture lands losses and road maintenance, based on field observations and discussions with affected people. Field work investigations have shown that

  8. Sustainability of land reclamation measures in erosional badlands: A comparative perspective on semi-arid landscapes of South Morocco and Central India

    Science.gov (United States)

    Marzolff, Irene; Pani, Padmini; Mohapatra, Surya; Ghafrani, Hassan; Aït Hssaine, Ali

    2015-04-01

    Semi-arid regions around the world, where gully erosion is a major land-degradation process, are particularly vulnerable to the effects of population growth and land-use change. In regions with high pressure on land as a resource - either due to population pressure or to agricultural intensification or both - erosion-affected areas are increasingly being reclaimed as agricultural land in an endeavour to turn marginal or unused land into fields, plantations, greenhouses or even building ground. Depending on the severity and depth of the erosion processes, this may be done by ploughing (for ephemeral gullying), land-levelling with bulldozers (for permanent gullies and badlands) or infilling with ex situ material (for large and deep gullies and badlands). The success of such measures, which also depends on subsequent soil-erosion protection, varies strongly and is not yet well researched. The little developed part of Lower Chambal Valley (Madhya Pradesh) is one of the four regions most badly affected by gully and badland erosion in India. Around 80% of the rural population are dependent on agriculture, an estimated 5000 km² are affected by gullies and badlands as deep as 80 m. Various land reclamation measures have been conducted on widely different spatial scales both by governmental and non-governmental agencies and individual farmers. However, the reclamation strategies of rich and poor farmers also exhibit significant differences, and agricultural use that often is based on short-term economic needs of households leads to inefficient land-use practices particularly in land-levelled and reclaimed areas. Although set in rural surroundings as well, the Souss Valley (South Morocco) is characterized by highly dynamic land-use changes with transformations from traditional agriculture to vast agro-industrial plantations of citrus fruits, bananas and vegetables. These plantations, as well as other arable land, are threatened by gullies and other forms of soil erosion

  9. Efeito da colheita seletiva de madeira sobre algumas características físicas de um latossolo amarelo sob floresta na Amazônia Central Effect of selective logging on some physical characteristics of a yellow latosol under rainforest in Central Amazonia State

    Directory of Open Access Journals (Sweden)

    Walane Maria Pereira de Mello-Ivo

    2006-10-01

    objective of this study was to evaluate the effects of selective logging on some soil physical characteristics. The study area lies about 80 km north of Manaus and the vegetation is a humid tropical rainforest. Seven to ten trees/ha (DAP > 55 cm were felled and removed by a D6 bulldozer, in 1993. Six disturbance classes were defined in the logged plots, with three replicates each: tractor track, center of clearing, edge of clearing, edge of forest, remaining forest and control forest. Soil under tractor tracks represented 13.8 % of the exploited area, and showed higher values of bulk density, and penetration resistance, and lower macroporosity and available water for plants than the other disturbance classes. The other classes were less affected and no significant differences were observed between their soil properties and the control forest, indicating selective logging as a practice that causes less impact on soils of Amazon forest ecosystems.

  10. Research on the extension of Tamarix shrubs resulted from development projects in arid area%干旱区开发工程引起柽柳植丛扩展现象研究

    Institute of Scientific and Technical Information of China (English)

    黄培祐; 高瑞如

    2004-01-01

    Tamarix plant is widely distributed in the arid areas of China for its great tolerance of draught, salt and alkali and attracts more attention by its strong capacity in windbreak and sand-fixations. "Tamarix dunes " constitute special desert bio-landscape in arid area. During last several decades, Tamarix shrubs declined and "Tamarix dunes" were also severely destroyed due to the land exploitation and serious deforestation, etc. From the 1980s until now, the extending phenomenon of Tamarix shrubs caused by developmental projects such as building highway, railway was studied in the western dry area of China, including western section of Hexi Corridor of Gansu, railroads and highways around the two greatest basin in Xinjiang and interior regions in Gurbantonggut desert, through on-the-spot survey along the transportation lines and setting up sampling plots along the roads. It was found that large quantities of Tamarix plants grow in the catchment area of low-lying lands that were formed by bulldozer operation during road building period. The extension of Tamarix shrubs caused by engineering was similar to that of the other section of the area to some extent, but went beyond the original distribution. This extension is beneficial to the ecological restoration and re-vegetation of western region of China and plays an important role in control of the sandstorms and improvement of ecological environments. As a result, it is necessary to make a further study on the extending phenomenon of Tamarix shrubs and to seek approach to promote wider extension of Tamarix shrubs in suitable habitats.%柽柳植物以其适应干旱、盐碱等恶劣环境而自然生繁于我国干旱地区,又以其强大的防风固沙能力在干旱区备受关注."红柳沙包"是干旱区颇为特异的生物景观.近数十年来,由于土地开发和樵伐等原因,柽柳植丛逐渐衰退,由柽柳植丛形成红柳沙包也被严重破坏.从20世纪80年代至今,作者在我国西部

  11. A New Perspective on Mount St. Helens - Dramatic Landform Change and Associated Hazards at the Most Active Volcano in the Cascade Range

    Science.gov (United States)

    Ramsey, David W.; Driedger, Carolyn L.; Schilling, Steve P.

    2008-01-01

    south of the 1980-86 lava dome. The erupting lava cleaved Crater Glacier in half and bulldozed it aside, causing thickening, crevassing, and rapid northward advance of the glacier?s east and west arms. Intermittent steam and ash explosions, some generating plumes that rose up to 11 kilometers, preceded and accompanied extrusion of the new lava dome, but ceased by early 2005. As the new dome grew, a series of large fins or spines of hot lava rose, some more than 100 meters high, and then crumbled producing sometimes spectacular rock falls. The largest of these rock falls generated dust or steam plumes that rose high above the crater rim. By February 2006, the new dome had grown to a volume similar to that of the 1980-86 lava dome; and by July 2007, the new dome had grown to a volume of 93 million cubic meters, exceeding the volume of the 1980-86 lava dome. The height of the new dome also exceeded that of the 1980-86 lava dome, and at its highest point (before collapse in 2005) reached to within 2 meters of the lowest point on the south crater rim. At this height, the new dome was taller than the Empire State Building in New York City. The new lava dome initially grew very quickly, at rates of 2 to 3 cubic meters (one small dump truck load) per second. If it had continued to grow at these rates for about 100 years, it would have replaced the volume of rock removed from the volcano during the May 18, 1980, eruption. However, the lava extrusion rate slowed throughout the eruption, and, by July 2007, it was oozing at a rate of 0.1 cubic meters per second. At that rate, it would take over 700 years to replace the volume of rock lost in 1980. Lava dome extrusion has continued into early 2008.

  12. 羽毛球接发球不同处理方式的效果对比研究--以2014年全国团体赛广西第一女双的比赛为例%Comparison of Receiving Effect in the Women’s Doubles Badminton---A Case study on the Games of the First Pair of Guangxi Players in 2014 National ;Team Competition

    Institute of Scientific and Technical Information of China (English)

    陈然; 于勇; 李霞; 邹金辉

    2015-01-01

    以2014年国羽毛球女子团体赛广西队第一双打对湖北队和福建队的两场比赛为例,对羽毛球女双接发球不同处理方式的优劣势效果进行对比分析,对广西球员实行录像回放指导方法干预,比较干预后的实战效果,探讨接发球技术使用的制胜规律,旨在为广西乃至全国羽毛球女双运动员的针对性训练提供参考。研究结果表明:接发球采用抢放、扑压、推平球的优势效果明显好于推高球、起高球。奥运会冠军、国家队队员在接发球处理的技术能力、战术意识明显强于省队队员,接发球多采用扑压、推平球、抢放等技术,处理方式更为积极,为本方取得主动局面,占据场上优势。录像回放和指导后运动员接发球处理取得优势效果的百分比大幅提高,说明此干预方法有助于强化年轻运动员的接发球抢网意识,改进其接发球处理方式。建议在训练和比赛中要贯彻“快、狠、准、活”的原则,加强身体素质训练,提高接发球的启动速度,保证抢网的效果;加强扑压球、平推球、抢放网的训练,加强抢网下压平推的战术意识,在比赛实战中敢于运用,在发接发的处理中争取主动。%Taking 2 games of the first pairs in Guangxi Vs Hubei, Guangxi Vs Fujian in 2014 national badminton women’s team competition for example, this paper com-pared and analyzed the advantages and disadvantages of the effect of diffrent treatment of receiving in women’s doubles badminton, using the intervention method in Guangxi players with video playback and guidance,com-pared the actual combat effect after intervention,discussed the winner rules of receiving technology, to provide the reference for the targeted training of the women’s doubles badminton athletes in Guangxi and even the whole coun-try. The research results show that the advantage effect of receiving with flapping,bulldozed ball is

  13. Detailed sedimentology and geomorphology elucidate mechanisms of formation of modern and historical sequences of minor moraines in the European Alps

    Science.gov (United States)

    Wyshnytzky, Cianna; Lukas, Sven

    2016-04-01

    moraines here formed as push moraines in two groups separated by a former proglacial basin and are composed dominantly of pre-existing proglacial outwash gravel through efficient bulldozing of the glacier front (Lukas, 2012). These findings show a range of mechanisms responsible for moraine formation. Furthermore, basal freeze-on processes incorporating subglacial sediment (till) have not been recorded in high-mountain moraine formation, suggesting a commonality of seasonal climatic controls between the glacier dynamics of high-mountain glaciers and those in more lowland, maritime settings. References Andersen, J.L., and Sollid, J.L., 1971, Glacial Chronology and Glacial Geomorphology in the Marginal Zones of the Glaciers, Midtdalsbreen and Nigardsbreen, South Norway: Norsk Geografisk Tidsskrift - Norwegian Journal of Geography, v. 25, no. 1, p. 1-38, doi: 10.1080/00291957108551908. Beedle, M.J., Menounos, B., Luckman, B.H., and Wheate, R., 2009, Annual push moraines as climate proxy: Geophysical Research Letters, v. 36, no. 20, p. L20501, doi: 10.1029/2009GL039533. Boulton, G.S., 1986, Push-moraines and glacier-contact fans in marine and terrestrial environments: Sedimentology, v. 33, p. 677-698. Evans, D.J.A., and Benn, D.I., 2004, A Practical Guide to the Study of Glacial Sediments: Hodder Education, London, United Kingdom. Hewitt, K., 1967, Ice-Front Deposition and the Seasonal Effect: A Himalayan Example: Transactions of the Institute of British Geographers, v. 42, p. 93-106. Kjær, K.H., and Krüger, J., 2001, The final phase of dead-ice moraine development: processes and sediment architecture, Kötlujökull, Iceland: Sedimentology, v. 48, p. 935-952. Krüger, J., 1995, Origin, chronology and climatological significance of annual-moraine ridges at Myrdalsjökull, Iceland: The Holocene, v. 5, no. 4, p. 420-427. Lukas, S., 2012, Processes of annual moraine formation at a temperate alpine valley glacier: insights into glacier dynamics and climatic controls: Boreas, v

  14. The coral reef of South Moloka'i, Hawai'i - Portrait of a sediment-threatened fringing reef

    Science.gov (United States)

    Field, Michael E.; Cochran, Susan A.; Logan, Joshua; Storlazzi, Curt D.

    2008-01-01

    finally washed out of the system—and that only happens if there is no more new mud washing onto the reef.I saw this myself a few years ago in Pila‘a Bay on Kaua‘i, where a bulldozed hillside of abandoned sugar cane fields had slumped right on top of a coral reef following exceptional rains. Years later, the algae species were zoned in a way that clearly mapped the distribution of nutrients washed into the bay, most likely from fertilizers bound to the eroded soils. That pattern closely mimics, on a small scale, that shown in Moloka‘i in this volume, where the inner reef is covered with algae, zoned by species in a way that points to land-based sources of nutrients, while the outermost reef slope is still coral dominated, and the deep algae seem to indicate deep-water nutrient upwelling.What of the future? The Hawaiian Islands have been exceptionally fortunate to be spared the worst coral heatstroke death from high temperatures, at least to date. So far, the worst global warming impacts have luckily been small in this region, and the small number of people on Moloka‘i has kept population densities, and sewage pollution, low compared to the more developed islands. Nutrients from years of sugar and pineapple fertilization, and the washing of this soil onto the reefs, show clear influences on the pattern of algae on the reef. Even at very low levels of nutrients, well below that which drives algae to smother and kill coral reefs, more algae is present. Soil erosion control is therefore the key to better management of both nutrients and turbidity on Moloka‘i reefs. To that end land management actions mentioned in this book, such as suppressing wild fires and eliminating wild goats and pigs, could be made even more effective if supplemented by active erosion control using plants whose roots bind the soil effectively in place. Through all of these efforts, Hina and the people of Moloka‘i could be happy again!