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. Study on Engine Speed Controling System of Industrial Bulldozer

    Institute of Scientific and Technical Information of China (English)

    冯开林; 陶明; 杨为民; 王世明; 陈康宁

    2003-01-01

    The functional range of actiyator of diesel engine used in bulldozer was limited when the load of bulldozer was heavy, inconstancy and in the condition of fine working. For this reason the engine rotary speed controlling system consisted of digital controller and proportional actuator was applied; to meet the needs of high controlling precision requirement the online system identification for the engine rotary speed controlling system was carry out;Based on the result of system identification the control parameter PID was optimized. Test study proved that this engine speed controlling method have an excellent speed controlling performance.

  3. FRACTOGRAPHY OF OPERATION FAILURE OF THE LITING GEAR OF BULLDOZER

    Directory of Open Access Journals (Sweden)

    Yakovleva S. P.

    2013-11-01

    Full Text Available The nature and causes of operational failure of the all-metal hydraulic cylinder rod of a bulldozer were studied. It is shown that the main mechanism of failure was evolving in time metal fatigue, initiated by defects of the heat treatment for chromizing

  4. 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.

  5. EXPERIMENTAL AND NUMERICAL RESEARCH ON BULLDOZER WORKING PROCESS

    Institute of Scientific and Technical Information of China (English)

    LI Yanjie; XU Yong; HUANG Wenbin; FENG Y T; OWEN D R J

    2007-01-01

    A simulative analysis coupled with experiment on behaviors of a soil bed cut by a model bulldozer blade is carried out using the finite element/distinct element method(FE/DEM) facility built in the ELFEN package. Before simulation, the soil specimens are examined through uniaxial tensile/compression, triaxial compression and direct shear tests to obtain model characteristics and relevant parameters, then soil cutting experiments are carried out via a mini-soil bin system with a soil bed of 60/120 mm in width and 10 mm in depth cut by a 1/9 scale model bulldozer blade moving with the velocity of 10 mm/s. The soil constitutive model includes the tensile elastic model for tensile breakage and the compressive elastoplastic relationship with Mohr-Coulomb criterion. The cutting length in simulation is set as 1/4 of that in the experiment divided into 1 869 triangular elements. The comparison between the simulated results and experimental ones shows that the used model is capable of analyzing soil dynamic behaviors qualitatively, and the predicted fracturing profiles in general conform to the experiment. Hence the feasibility for analyzing soil fracturing behaviors in tillage or other similar processes is validated.

  6. 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.

  7. Research on Fuel Consumption of Hybrid Bulldozer under Typical Duty Cycle

    Science.gov (United States)

    Song, Qiang; Wang, Wen-Jun; Jia, Chao; Yao, You-Liang; Wang, Sheng-Bo

    The hybrid drive bulldozer adopts a dual-motor independent drive system with engine-generator assembly as its power source. The mathematical model of the whole system is constructed on the software platform of MATLAB/Simulink. And then according to the velocity data gained from a real test experiment, a typical duty cycle is build up. Finally the fuel consumption of the bulldozer is calculated under this duty-cycle. Simulation results show that, compared with the traditional mechanical one, the hybrid electric drive system can save fuel up to 16% and therefore indicates great potential for lifting up fuel economy.

  8. 履带推土机行走系统推土转向工况仿真%Simulation of Walking System of Crawler Bulldozer in Bulldozing Steering Condition

    Institute of Scientific and Technical Information of China (English)

    张耀娟; 成凯

    2015-01-01

    采用多体动力学仿真软件RecurDyn对履带推土机行走系统推土转向作业工况进行运动学与动力学仿真研究.建立了与实际工况相同的仿真模型,对驱动轮力矩、张紧弹簧和托链轮所受载荷进行分析,得出各自所受载荷规律.所采用的虚拟样机技术,可作为履带式工程机械仿真研究的方法,仿真结果可作为履带推土机设计与优化的参考依据.%In order to study stress condition of various parts of walking system of crawler bulldozer when bulldozer is bulldozing as well as steering, this article uses the Multi Flexible Body Dynamics simulation software RecurDyn,it is created the simulation model that is the same as practical condition. The driving wheel torque, tension spring and carrying wheel load are analyzed and studied. Then it concluded that the law of load above parts. The virtual prototype technology can be applied to simulation research of tracked engineering machinery. The simulation results can be used as reference of design and optimization of crawler bulldozer.

  9. 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 .

  10. Current Status and Development Trends of Domestic and Oversea Bulldozer%国内外推土机的发展现状及趋势

    Institute of Scientific and Technical Information of China (English)

    蔡应强; 陈清林

    2013-01-01

    By analyzing the technology and market current status of domestic and oversea major bulldozer enterprises,the shortcomings of domestic bulldozer were pointed out,and a synthesis of technological gap between domestic bulldozer and the advanced level abroad was made. The development trends and research direction of domestic and oversea bulldozer in the future were concluded.%  通过分析国内外主要推土机生产企业技术及市场现状,指出国产推土机存在的不足,综合分析了国产推土机与国际先进水平的差距,总结出了国内外推土机的发展趋势和研究方向。

  11. 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.

  12. 混合动力推土机功率匹配控制研究%Power Matching Control Study of Electric Drive Bulldozer

    Institute of Scientific and Technical Information of China (English)

    姜友山; 金轲; 韦海云

    2014-01-01

    针对混合动力推土机的特点,通过对比履带实际行驶速度与电动机输出速度对应的履带理论行驶速度的大小关系,对混合动力推土机功率匹配控制方法进行了探讨,为提高混合动力推土机能量传递效率、降低能量损耗提供了理论依据。%The power matching control method of electric drive bulldozer was discussed according to the characteristics of electric drive bulldozer by comparing the relationship between the track actual speed and the motor output speed which was consistent with the crawler theory running speed.It provides theory basis for improving the efficiency of energy transmission of electric drive bulldozer and reducing energy consumption.

  13. Strength Finite Element Analysis of Bulldozer Drive Shaft%推土机传动轴强度有限元分析

    Institute of Scientific and Technical Information of China (English)

    白鹏伟; 史青录; 程结结; 周绍利

    2012-01-01

    利用ANSYS Workbench软件建立某型号推土机转向离合器输入轴在转矩载荷作用下的有限元模型,并对其进行有限元分析,得到传动轴危险部位的应力与应变结果.结果表明在花键或有过渡圆角的部位最易发生失效.%A finite element model was set up by utilizing ANSYS Workbench software for the steering clutch input shaft in a certain type bulldozer under a turning torque load while carrying out a finite element analysis thereof to have got stress and strain results at dangerous positions of the drive shaft. The results show that failures are vulnerable to happen at positions of the spline and/or transit radius.

  14. BULLDOZING AND RESTING TRACES OF FRESHWATER MUSSEL ANODONTA WOODIANA AND SUBSTRATE CHARACTERISTICS IN LAKE-MARGIN AND RIVER SETTINGS OF UMBRIA, ITALY

    Directory of Open Access Journals (Sweden)

    PAOLO MONACO

    2016-03-01

    Full Text Available The neoichnology of the freshwater mussel Anodonta (Sinanodonta woodiana (Lea, 1834 is examined herein in some continental environments of Umbria (central Italy, such as lake-margin and river dam-margin settings. This study, based on analysis of about 200 traces, reveals that this mussel burrows employing two types of behaviours: bulldozing which produces horizontal meanders to straight bilobate traces, often filled with peloidal faecal pellets (pseudofaeces and backfill, and resting (vertical stationary into substrate while filter feeding. A new type of very soft substrate, the ‘cloudground’ is proposed. It is placed at the water-sediment interface, above the soupground. After four years of observation, the cloudground was buried with shells and traces, preserving through the fossilization barrier about 20% of the Anodonta traces. This bivalve activity is a useful tool to recognize preservation of mud in quiet environments and parallels ichnological evidence of unknown epichnial trace fossils in the continental realm. Cloudground with resting traces must be investigated also in modern marine basin floor environments where cloud of mud dominates and considered also in geological record.

  15. Bulldozing Your Way Through Projectile Motion.

    Science.gov (United States)

    Lamb, William G.

    1983-01-01

    Presents two models and two demonstrations targeted at student understanding of projectile motion as the sum of two independent, perpendicular vectors. Describes materials required, construction, and procedures used. Includes a discussion of teaching points appropriate to each demonstration or model. (JM)

  16. The Snowmastodon Project: cutting-edge science on the blade of a bulldozer

    Science.gov (United States)

    Pigati, Jeffery S.; Miller, Ian M.; Johnson, Kirk R.

    2015-01-01

    Cutting-edge science happens at a variety of scales, from the individual and intimate to the large-scale and collaborative. The publication of a special issue of Quaternary Research in Nov. 2014 dedicated to the scientific findings of the “Snowmastodon Project” highlights what can be done when natural history museums, governmental agencies, and academic institutions work toward a common goal.

  17. 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

  18. Bulldozers, mental models, and aerial photography: Geographies of long-term private restoration on semi-arid rangelands

    Science.gov (United States)

    Private efforts to restore degraded Southwestern desert grasslands have been under way at least since the 1920s, but their effects are little studied and poorly understood. Most are considered simply to have failed, or to have been swamped by the effects of climate and fire suppression. These judgme...

  19. 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.

  20. 推土机单手柄转向、制动电液比例控制系统研制%Development of Hydro-electric Proportional Control System for Joystick Steering and Braking of Bulldozer

    Institute of Scientific and Technical Information of China (English)

    宫文斌; 赵晓红; 刘昕辉

    2004-01-01

    文章以推土机的转向和制动为主要研究内容,利用电液比例控制技术和PIC系列的单片机作为控制器,研制了推土机单手柄转向、制动控制系统,实现了推土机转向、制动的单手柄集中控制.介绍了该系统的总体方案设计,并对系统的硬件、软件做了比较详细的叙述.

  1. 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.

  2. 77 FR 60749 - Endangered and Threatened Wildlife and Plants; Proposed Endangered Species Status for the Florida...

    Science.gov (United States)

    2012-10-04

    ... on reproduction and demography is sparse. The Florida bonneted bat has low fecundity; litter size is... ``found under rocks when bull-dozing ground'' (Timm and Genoways 2004, p. 860). A colony was found in...

  3. 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.

  4. 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…

  5. 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…

  6. 29 CFR 1926.914 - Definitions applicable to this subpart.

    Science.gov (United States)

    2010-07-01

    ... in a drill hole, or to cover explosives in mud-capping. (y) Springing—The creation of a pocket in the... been loaded in a drill hole. (h) Conveyance—Any unit for transporting explosives or blasting agents... charge which failed to detonate. (r) Mud-capping (sometimes known as bulldozing, adobe blasting,...

  7. Final Environmental Assessment for Construction of Fisher House II, Wright-Patterson Air Force Base, Ohio

    Science.gov (United States)

    2008-03-25

    Impacts would be minimized by implementing erosion and siltation controls. Cultura l Resources (EA Section IV.F.): The proposed action is located...bulldozers (79-91 dB at 50 feet). It is possible to fit equipment with internal combustion engines with exhaust mufflers to provide a 5-10 dB noise

  8. Sub-Saharan Africa Report.

    Science.gov (United States)

    2007-11-02

    1987) 55 First Stage of Old Crossroads Upgrading Begins (Diane Cassere ; CAPE TIMES, 12 Mar 87) 61 Philosophy, Influence of Black Consciousness...87 p 5 [Article by Diane Cassere ] [Text] THE bulldozers are back at Crossroads — but this time to give it a R9,25-million facelift. This is the

  9. 40 CFR 1068.30 - What definitions apply to this part?

    Science.gov (United States)

    2010-07-01

    ..., particulate filter, or any other system, component, or technology mounted downstream of the exhaust valve (or... itself and performing another function (such as garden tractors, off-highway mobile cranes and bulldozers... storage areas or facilities, times during which people other than custodians and security personnel are...

  10. 40 CFR 89.2 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... technology that reduces emissions by routing exhaust gases that had been exhausted from the combustion... itself and performing another function (such as garden tractors, off-highway mobile cranes and bulldozers... conditions will be allowed with prior approval of the Administrator. Sulfur-sensitive technology means...

  11. ЭКОЛОГИЧНОСТЬ МЕТОДОВ И СРЕДСТВ ТУШЕНИЯ ЛЕСНЫХ ПОЖАРОВ (ОЦЕНКИ И РЕКОМЕНДАЦИИ)

    OpenAIRE

    ТЕЛИЦЫН Г.П.; ОСТРОШЕНКО В.В.

    2008-01-01

    Ecological assessment of existing techniques for forest fire suppression is given. Water-based methods are admitted most ecologically suitable. Chemical water solutions pollute both the forest floor and water receptors. Bulldozer lines are not ecologically admissible and their use for forest fire suppression must be restricted.

  12. 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.

  13. USSR Report, International Affairs

    Science.gov (United States)

    2007-11-02

    collecting metal pots and pans and other belongings. Several bulldozers, their strained engines revving, were filling in an enormous crater. "It was...country. Some people contribute money, some jewelry , others bicycles or motorcycles. The war has entered the home of virtually every Iranian and...ponsibility must prevail, not secondary friction and internecine strife." /9738 CSO: 1807/106 62 MIDDLE EAST/NORTH AFRICA/SOUTH ASIA ISRAELI

  14. Peterson Air Force Base Transportation Plan Final Environmental Assessment

    Science.gov (United States)

    2013-03-01

    Rocky Mountains . The majority of lands on Peterson AFB have been impacted by construction activities (e.g., excavation, grading, and bulldozing) and...The fauna of Peterson AFB and surrounding area is a mixture typical of both the foothills of the Southern Rocky Mountains and the western edge of...SSC Potentially present foraging for small mammals , including black-tailed prairie dogs Mountain Plover Charadrius montanus SSC Present as rare

  15. A History of the Louisville District, Corps of Engineers United States Army, 1970-1983

    Science.gov (United States)

    1984-01-01

    under oral agreements pending formal con- tracts, contractors with 134 bulldozers, graders, and other equipment promptly 85 went to work pushing...land acquisition phase, studied the village and its people, and in 1976 pub- lished an award-winning collection of oral interviews with the people...Historian 2 (Spring 1980):71-76; Ronald W. Johnson, "The Historia n and Cultura l Resource Management," Public Historian 3 (Spring 1981): 43-51

  16. Attacking Time

    Science.gov (United States)

    2015-06-01

    enforces protections for process memory using the read/write (R/W) and execute disable (XD) bits. When a process is loaded, the bits are set so that...present in newer Intel CPUs ( AMD has similar technology). EPT provides an extra layer of address translation that is transparent to the guest operating...boundary provided by the processor. These processors include the Intel i7, AMD bulldozer, and multiple ARM variants, including the A8 and A9. The

  17. Management of Florida Scrub for Threatened and Endangered Species

    Science.gov (United States)

    1998-12-01

    now known to be dissimilar in composition and structure based on differences in soils and disturbance regimes; allelopathy (the ability to produce...hearty enough to survive under this nutrient stress will grow on scrub soils. Some scrub plants may use allelopathy to avoid competition for scarce...seed and by rhizomes, which can be transported on equipment (e.g., bulldozers; FNAI 1994b, USFWS 1995). Rhizoma- tous spread and allelopathy aid

  18. First on the Line: The 35th Engineer Battalion in World War Two and the Evolution of a High-Performance Combat Unit

    Science.gov (United States)

    2009-12-11

    fifty-five gallon steel drum and various other parts. He was soon running a full-fledged laundry service for the regiment. 46 Stories of the...banter faded as the 35th‘s first bulldozer suddenly burst from the thicket. Trailing broken vines and mangled branches, it lumbered down the bank...erection of telephone poles and the construction of four camps along the route. 52 However, the project was soon embroiled in deep controversy as many in

  19. A Study on the Bionomics of Anopheles darlingi Root (Diptera: Culicidae) in Belize, Central America

    Science.gov (United States)

    2004-03-01

    shown). (B) A supervised classification of the image was used to quantify the difference in pixel counts of broadleaf/ palm forest (green), pasture...flow by bulldozed forest debris; contamination of freshwater by agrochemicals; and eutrophication of waterways by discharge from food and sugar...conditions of high populations and/or malaria transmission, the application of oils to potential breeding habitats surrounding homes will be performed

  20. 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.

  1. [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.

  2. 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."

  3. Obtención de ecuaciones de correlación para estimar las velocidades de las ondas de corte en los suelos de la ciudad de Guayaquil

    OpenAIRE

    Ramirez Calderon, Jenny; Tandazo Ortega, Eddie; Vera Grunauer, Xavier

    2009-01-01

    La presente tesis establece un aporte a los ingenieros consultores y diseñadores, proporcionándoles ecuaciones semiempíricas para la estimación de la velocidad de la onda de corte, adaptadas para los suelos de la ciudad de Guayaquil. Para la realización y obtención del perfil de velocidad de onda de corte se llevó a cabo una campaña de medición de las ondas de superficie generadas por una fuente activa (martillos, bulldozers) de vibraciones aleatorias de alta y baja frecuenc...

  4. Understanding tourist beaches as eco-social landscapes: seeking sustainability through integration of human and non-human wealth production

    Directory of Open Access Journals (Sweden)

    Jeff Baldwin

    2008-02-01

    Full Text Available IntroductionNow coral reefs are not merely pretty, ...of much greater consequence is their vital importance of protecting our shores, this may not be generally realised. We had a nice example of this in Barbados recently when a certain hotel, in order to improve its beach facilities, bulldozed a certain piece of inshore reef to make a “white hole” for bathing. Although the area removed was perhaps only 20 x 30 yards, the consequent change in wave action resulted not only in the removal of the...

  5. 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.

  6. Penerapan Reduced Impact Logging Menggunakan Monocable Winch (Pancang Tarik (Implementing Reduced Impact Logging with Monocable Winch

    Directory of Open Access Journals (Sweden)

    Yosep Ruslim

    2012-01-01

    Full Text Available Forest harvesting still encounters many problems especially concerning impact to the residual stand  and environmental damage. Implementing the reduced impact monocable winch and planning of good skid trails should have a positive impact on work efficiency as well as, reducing damage to the residual stand and soil during felling and skidding activities. Reduced impact logging (RIL with a monocable winch (Pancang Tarik system has been tried in several IUPHHKs and it can be concluded that RIL monocable winch system could be applied practically and reduce impact on residual stand and soil damage. Using this technology has many advantages, among others: cost efficiency, locally made, environmental friendly, and high local community participation. Application of  the monocable winch  system in reduced impact logging is an effort to reduce economical and environment  damages when compared to conventional system of ground based skidding with bulldozer system. The aim of this research is to verify the efficiency (operational cost, effectiveness (productivity and  time consumption of monocable winch system. The results  indicate that the implementation monocable winch system, has reduced the soil damage as much as 8% ha-1.  The skidding cost  with monocable system is Rp95.000 m-3. This figure is significantly cheaper if compare with ground base skidding with bulldozer system in which the skidding cost around Rp165.000 m-3.Keywords: mononocable winch, productivity,  skidding cost, reduced impact logging, local community

  7. 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%.

  8. 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

  9. 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.

  10. full on riot

    Directory of Open Access Journals (Sweden)

    Moses Iten

    2005-08-01

    Full Text Available “hey moses full on riot in lawson st the station’s on fire! been going since 4. molotov and more. full on,” reads an SMS message received on the backseat of a Tasmanian bus. What follows is a journey through the landscape of a Gunavidji, whose brothers have all gone to the land of the dead; metallic scraping in the glass cases of the Hobart Museum; a Palestinian woman giving up on her people; land-snails exposing cultural inaccuracies; photographing Australia’s war zone; entering the St Peter’s Basilica of Rome with bulldozers - all in the name of preparing to interview prominent Israeli writer Etgar Keret.

  11. 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.

  12. 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.

  13. Reducing level of manual labor at Kuzbassshakhtostroi construction sites

    Energy Technology Data Exchange (ETDEWEB)

    Gorlin, V.F.; Kosukhin, A.I.

    1988-07-01

    Relates how Kuzbassshakhtostroi is dealing with the task of reducing the proportion of manual labor in mine construction work. At present about half the employees is engaged in manual labor (61.3% of construction and assembly workers). Developments helping to phase out manual labor include: Wirth L-35 drilling units, K-1000 cranes and KS-2V/40 loaders for shaft excavation; small bulldozers and excavators; UDB foundation blocks for blowers, etc.; T-shaped concrete pieces for air ducts; standardization of foundation pieces; plastic pipes joined by welding or glueing; plasterboard sheets for buildings; new methods in concreting and plastering work; contour blasting to give more precise roadway contours. Better communication between design institutes and mine construction enterprises is urged.

  14. Improving machine operation management efficiency via improving the vehicle park structure and using the production operation information database

    Science.gov (United States)

    Koptev, V. Yu

    2017-02-01

    The work represents the results of studying basic interconnected criteria of separate equipment units of the transport network machines fleet, depending on production and mining factors to improve the transport systems management. Justifying the selection of a control system necessitates employing new methodologies and models, augmented with stability and transport flow criteria, accounting for mining work development dynamics on mining sites. A necessary condition is the accounting of technical and operating parameters related to vehicle operation. Modern open pit mining dispatching systems must include such kinds of the information database. An algorithm forming a machine fleet is presented based on multi-variation task solution in connection with defining reasonable operating features of a machine working as a part of a complex. Proposals cited in the work may apply to mining machines (drilling equipment, excavators) and construction equipment (bulldozers, cranes, pile-drivers), city transport and other types of production activities using machine fleet.

  15. Effects of Heavy, Tracked-Vehicle Disturbance on Forest Soil Properties at Fort Benning, Georgia

    Energy Technology Data Exchange (ETDEWEB)

    Garten, C.T.,JR.

    2004-05-20

    The purpose of this report is to describe the effects of heavy, tracked-vehicle disturbance on various measures of soil quality in training compartment K-11 at Fort Benning, Georgia. Predisturbance soil sampling in April and October of 2002 indicated statistically significant differences in soil properties between upland and riparian sites. Soil density was less at riparian sites, but riparian soils had significantly greater C and N concentrations and stocks than upland soils. Most of the C stock in riparian soils was associated with mineral-associated organic matter (i.e., the silt + clay fraction physically separated from whole mineral soil). Topographic differences in soil N availability were highly dependent on the time of sampling. Riparian soils had higher concentrations of extractable inorganic N than upland soils and also exhibited significantly greater soil N availability during the spring sampling. The disturbance experiment was performed in May 2003 by driving a D7 bulldozer through the mixed pine/hardwood forest. Post-disturbance sampling was limited to upland sites because training with heavy, tracked vehicles at Fort Benning is generally confined to upland soils. Soil sampling approximately one month after the experiment indicated that effects of the bulldozer were limited primarily to the forest floor (O-horizon) and the surface (0-10 cm) mineral soil. O-horizon dry mass and C stocks were significantly reduced, relative to undisturbed sites, and there was an indication of reduced mineral soil C stocks in the disturbance zone. Differences in the surface (0-10 cm) mineral soil also indicated a significant increase in soil density as a result of disturbance by the bulldozer. Although there was some tendency for greater soil N availability in disturbed soils, the changes were not significantly different from undisturbed controls. It is expected that repeated soil disturbance over time, which will normally occur in a military training area, would simply

  16. 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...

  17. Greenhouse Gas Assessment and Compensation on Brazilian Low Volume Rural Roads Using CarbonROAD—The Santa Rosa de Lima Case

    Directory of Open Access Journals (Sweden)

    Reus Salini

    2015-10-01

    Full Text Available The “Santa Catarina Rural” is a Program co-funded by The World Bank for improvements on 1300 km of low volume rural roads on Southern Brazil. The pioneer project under the program was on the municipality of Santa Rosa de Lima, where the greenhouse gas (GHG emissions resulting from the road improvement activities as well as the regular traffic were assessed on an experimental basis using the CarbonROAD software application. Here, we show details of the CarbonROAD software application and the construction emissions assessment procedure as well as the mitigating effect of the plants used for compensation. It was found that most of the emissions come from the road improvement work. This includes earthworks, fuel for motor graders, bulldozers and other machines, and materials and gravel extraction, industrialization and transportation, etc. Only a smaller portion comprises regular road traffic. The accumulated emission balance shows that the carbon absorption is larger than construction emissions after just 15 months. The potential for price appraisal of the generated carbon credits is explored.

  18. 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.

  19. 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.

  20. Evaluations of in-use emission factors from off-road construction equipment

    Science.gov (United States)

    Cao, Tanfeng; Durbin, Thomas D.; Russell, Robert L.; Cocker, David R.; Scora, George; Maldonado, Hector; Johnson, Kent C.

    2016-12-01

    Gaseous and particle emissions from construction engines contribute an important fraction of the total air pollutants released into the atmosphere and are gaining increasing regulatory attention. Robust quantification of nitrogen oxides (NOx) and particulate matter (PM) emissions are necessary to inventory the contribution of construction equipment to atmospheric loadings. Theses emission inventories require emissions factors from construction equipment as a function of equipment type and modes of operation. While the development of portable emissions measurement systems (PEMS) has led to increased studies of construction equipment emissions, emissions data are still much more limited than for on-road vehicles. The goal of this research program was to obtain accurate in-use emissions data from a test fleet of newer construction equipment (model year 2002 or later) using a Code of Federal Requirements (CFR) compliant PEMS system. In-use emission measurements were made from twenty-seven pieces of construction equipment, which included four backhoes, six wheel loaders, four excavators, two scrapers (one with two engines), six bulldozers, and four graders. The engines ranged in model year from 2003 to 2012, in rated horsepower (hp) from 92 to 540 hp, and in hours of operation from 24 to 17,149 h. This is the largest study of off-road equipment emissions using 40 CFR part 1065 compliant PEMS equipment for all regulated gaseous and particulate emissions.

  1. 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.

  2. The Thermal Simulation Analysis of the Hydraulic Torque Converter based on the MTALAB%基于MATlAB的液力变矩器的热仿真分析

    Institute of Scientific and Technical Information of China (English)

    吴新; 连晋毅

    2013-01-01

    针对液力机械传动中液力变矩器发热量过大的问题,简述了液力变矩器的发热机理.在所构建的热计算模型的基础上,以某型推土机的液力变矩器为实例,运用MATLAB编程并得出了发动机与液力变矩器共同工作时发热量与传动比的关系曲线,并应用Simulink软件对不同传动比下的油温进行了仿真,仿真结果反映了油温的动态变化趋势.可为底盘油冷系统的分析和优化提供一定的技术参考.%According to the excessive heat of hydraulic mechanical transmission, heating mechanism on torque converter is explained. With a certain type of torque converter in bulldozers, the relationship between heat production and transmission ratio is described by Matlab programing, which on the basis of thermal analysis model. Meanwhile, the oil temperature on different ratio can be simulated by simulink, the result reflects the dynamic changing trend of hydraulic oil temperature. It will provide some technical reference for the analysis of chassis oil cooling system.

  3. Neither altruistic suicide, nor terrorism but martyrdom: a Muslim perspective.

    Science.gov (United States)

    Abdel-Khalek, Ahmed M

    2004-01-01

    The objective of the present article is to elucidate specific Islamic and psychological aspects of martyrdom (Istish'had) in the light of one example, that is the Palestinian martyrs in the Israeli-Palestinian conflict. This conflict has historical roots. The day the British mandate in Palestine ended in 1948, Israel was declared a state. War broke out, and around half of the Palestinian population was expelled in the diaspora. In 1950, Israel passed a law that gave every Jew in any country the right to emigrate to Israel. Israelis are burying POWs alive, using arrested people as human spare parts for wounded Israelis, demolishing more than 17,000 houses, and bulldozing the farm lands. Therefore, the soil has become fertile ground for the growing phenomenon of martyrdom and has given rise to a culture of resistance, based on the Islamic principles of Jihad (holy war) and the right to resist the Israeli colonizer. Several specialists in Islamic law (Shari'a), consider that martyrdom is legitimate and does not count as suicide of any kind.

  4. Yemen watched from cement plant construction work. Cement plant koji wo toshite mita Yemen

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, M. (Kajima Corp., Tokyo (Japan))

    1993-06-25

    Construction of a cement plant was planned at southern part of Yemen. This is a cement plant with annual production 500,000 tons. The term of work was from January, 1990 to February, 1993. The present paper describes an outline the construction of this Cement Plant, the nationality and living environment in Yemen, and construction equipment which was used. The construction work consisted of 113,000m[sup 3] of digging, 82,000m[sup 3] of backfilling, 66,100m[sup 3] of concreting, and 29,285m[sup 3] of asphalt pavement. Reinforcing steel weighing 6,400 tons and steel frame weighing 3,600 tons were totally used. Equipment weighing 7,912 tons and electric devices weighing 1,299 tons were totally installed. For this construction work, two crawler cranes, six hydraulic cranes, aggregate plant, concrete mixers, and construction equipment, such as bulldozers, shovels, and dumpers, were brought from Japan. 5 figs.

  5. 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?

  6. 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.

  7. A method for assessing the physical recovery of Antarctic desert pavements following human-induced disturbances: a case study in the Ross Sea region of Antarctica.

    Science.gov (United States)

    O'Neill, Tanya A; Balks, Megan R; López-Martínez, Jerónimo; McWhirter, Judi L

    2012-12-15

    With increasing visitor numbers an understanding of the impacts of human activities in Antarctic terrestrial environments has become important. The objective of this study was to develop a means for assessing recovery of the ground surface desert pavement following physical disturbance. A set of 11 criteria were identified to assess desert pavement recovery. Assessed criteria were: embeddedness of surface clasts; impressions of removed clasts; degree of clast surface weathering; % overturned clasts; salt on underside of clasts; development of salt coatings; armouring per m(2); colour contrast; evidence of subsidence/melt out; accumulation of salt on cut surfaces; and evidence of patterned ground development. Recovery criteria were assigned a severity/extent rating on a scale from zero to four, zero being highly disturbed, and four being undisturbed. A relative % recovery for each criteria was calculated for each site by comparison with a nearby undisturbed control area, and an overall Mean Recovery Index (MRI) was assigned to each pavement surface. To test the method, 54 sites in the Ross Sea region of Antarctica were investigated including areas disturbed by: bulldozer scraping for road-fill, contouring for infrastructure, geotechnical investigations, and experimental treading trial sites. Disturbances had occurred at timescales ranging from one week to 50 years prior to assessment. The extent of desert pavement recovery at the sites investigated in this study was higher than anticipated. Fifty of the 54 sites investigated were in an intermediate, or higher, stage of desert pavement recovery, 30 sites were in an advanced stage of recovery, and four sites were indistinguishable from adjacent control sites (MRI = 100%). It was found that active surfaces, such as the gravel beach deposits at the Greenpeace World Park Base site at Cape Evans, the aeolian sand deposits at Bull Pass, and the alluvial fan deposits of the Loop Moraine field campsite, recovered relatively

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. EFFICIENCY ANALYSIS OF ENERGY ACCUMULATING MECHANISM FOR TRACTOR WITH ELECTROMECHANICAL TRANSMISSION

    Directory of Open Access Journals (Sweden)

    Ch. I. Zhdanovich

    2017-01-01

    Full Text Available Dependence of tractor wheel torque on theoretical tractor motion speed has been used for comparison of tractor operation with electromechanical transmission with installation of energy accumulating mechanism and without its installation. In this case a traction asynchronous electric motor is operating under nominal and limit conditions. The paper also considers dependence diagrams of actual input power for the traction asynchronous electric motor and its losses due to theoretical tractor motion speed. Tractor wheel torque is limited during the operation of the traction asynchronous electric motor with energy accumulating mechanisms by the following factors: maximum electric motor torque at the given frequency of supply voltage; maximum value of internal combustion motor output which can be transferred to the traction asynchronous electric motor; grip of the wheels. During the operation of the traction asynchronous electric motor with energy accumulating mechanisms there is a possibility for short power consumption without regard to the second limitation because it is possible to use power not only of internal combustion motor but also the power which is stored in the energy accumulating mechanisms. Comparison of characteristics has been made when a tractor is operating at high gear and when it is operating at all gears (that is two gears. Operation of the 5th class tractors has been analyzed for all possible cases (operation with energy accumulating mechanisms and without the mechanisms while being operated at all gears and various types of work: tilling, sowing, cultivation, bulldozing work, transport mode. In this case equipment has been used which is aggregated with the 5th class tractor. 

  13. Analysis and Treatment of Common Danger of Foundation Pit Eneineering%基坑工程常见险情分析与处理措施

    Institute of Scientific and Technical Information of China (English)

    杨文生; 薛丽影

    2015-01-01

    This paper introduced the main destructional forms of foundation pit engineering and discussed the usual danger and corresponding measures of foundation pit engineering construction process. According to the situation that one pit in Beijing will collapse,the text successfully excluded the danger by making bulldozing backpressure to slope angle,adding anchor,cutting off sewers and hardening ground etc.,then the text using further reinforcement that ensure the safety of the pit. An efficiency “security contingency plans” should be established according to the character of the project before construction of foundation pit engineering to ensure the safety of foundation pit engineering,at the same time foundation pit engineering risk management system should be strictly enforced.%介绍了基坑工程的主要破坏形式,探讨了基坑支护施工过程中常见的险情及相应处理措施。针对北京某基坑即将坍塌的情况,通过采取对坡角进行堆土反压、加设地锚、截断污水管、硬化地面等措施,成功排除了险情,并采取进一步的加固措施,保证了基坑的安全。基坑工程施工前要针对项目特点,建立行之有效的“安全应急预案”,严格执行基坑工程风险管理制度,确保基坑工程安全。

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Coulomb theory applied to accretionary and nonaccretionary wedges: Possible causes for tectonic erosion and/or frontal accretion

    Science.gov (United States)

    Lallemand, Serge E.; Schnürle, Philippe; Malavieille, Jacques

    1994-06-01

    Based on observations from both modem convergent margins and sandbox modeling, we examine the possible conditions favoring frontal accretion and/or frontal and basal tectonic erosion. Mean characteristic parameters (μ, μ*b and λ) are used to discuss the mechanical stability of 28 transects across the frontal part of convergent margins where the Coulomb theory is applicable. Natural observations reveal that "typical accretionary wedges" are characterized by low tapers with smooth surface slope and subducting plate, low convergence rates and thick trench sediment, while "nonaccretionary wedges" display large tapers with irregular surface slopes and rough subducting plate, high convergence rates and almost no trench fill. Sandbox experiments were performed to illustrate the effects of seamounts/ridges in the subduction zone on the deformation of an accretionary wedge. These experiments show that a wedge of sand is first trapped and pushed in front of the seamount which acts as a moving bulldozer. This is followed by a tunnelling effect of the subducting seamount through the frontal wedge material, which results in considerable sand reworking. At an advanced subduction stage, the décollement jumps back from a high level in the wedge to its former basal position. We conclude that a high trench sedimentation rate relative to the convergence rate leads to frontal accretion. In contrast, several conditions may favor tectonic erosion of the upper plate. First, oceanic features, such as grabens, seamounts or ridges, may trap upper plate material during their subduction process. Second, destabilization of the upper plate material by internal fluid overpressuring causing hydrofracturing is probably another important mechanism.

  20. 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.

  1. 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.

  2. 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.

  3. Bedload exports in a forest catchment following wildfire and terracing, north-central Portugal

    Science.gov (United States)

    Martins, Martinho A. S.; Machado, Ana I.; Serpa, Dalila; Prats, Sergio A.; Faria, Sílvia R.; Varela, María E. T.; González-Pelayo, Óscar; Keizer, J. Jacob

    2014-05-01

    In Portugal, the occurrences of wildfires are frequently, on average, affects some 100.000 ha of rural lands each year, but in extreme years such as 2003 and 2005 the burnt areas can go over 300.000 ha. Studies in various parts of the world, including Portugal, have well-documented a strong and sometimes extreme response in overland flow generation and associated soil losses following wildfire. Over the last two decades, the construction of terraces in preparation of a new eucalypt plantation has become increasingly common in the mountain areas of north-central Portugal, including in recently burnt areas. Terraces are traditionally viewed as a soil conservation technique, however, the present authors have measured high splash and inter-rill erosion on recent terraces and have frequently observed gully formation connecting the terraces over the full hill slope length, as well as within the adjacent unsealed roads. The present study was carried out in a forest catchment in the north-central Portugal that was burnt by a wildfire during the summer of 2010 and logged and then terraced with a bulldozer during the winter 2010. The burnt catchment of roughly 25 ha was instrumented with two subsequent flumes with maximum discharge capacities of 120 and 1700 l sec-1. The bed load that deposited in the smallest flume was removed and weighted in the field at regular intervals during the subsequent three years. The records are being now analyzed, nonetheless preliminary results suggested that, besides the wildfire effects, also post-fire land management played an important role on bedload exports.

  4. 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

  5. Eliminating persistent fires on a large area in the zone of delimiting quarry fields of Merkur-Brezno. [Czechoslovakia

    Energy Technology Data Exchange (ETDEWEB)

    Stuchlik, R.; Schicker, J.

    1982-01-01

    Lignite in the North Czech Basin (CSSR) has a tendency to spontaneous combustion. Favorable conditions for spontaneous combustion and fires are created because of accumulation of coal fines. Usually the site of ignition is sprinkled with rock, mainly clay rocks of the overhanging side. Within several days, a fire develops through the layer of these rocks and spreads further. Despite this, in the majority of cases attempts are made to again eliminate the fire by sprinkling the next layer of clay materials. Thus persistent fires develop which can no longer be eliminated by standard resources. A characteristic example is a fire that has persisted in a large area on the boundary of two quarries Merkur and Brezno. This section has not been worked since 1970. Underground mining in this area was previously not done. Measures to eliminate fires initially were taken only when the fire covered practically the entire front of extraction work. The area spread of the fire was promoted by the fact that the clay rocks of the overhanging side contain fuel shales. On an area of length 300 m and height 12-15 m, an oblique ledge was made which was then sprinkled with a layer of clay rocks of the overhanging side. This fostered expansion of the fire. In order to eliminate the fire, continuous method of extinguishing was used which stipulates cooling of the rock at the site of combustion and subsequent removal of them. The process continued until cooling of the rock below 30/sup 0/C. Cooling was done using tangential sprayers, injection wells and by filling the well with carbon dioxide. Elimination of the fire lasted 14 weeks. The excavator DN-101 and bulldozers DT-250 were used to eliminate the cooled rocks.

  6. 彰武沙地水利改良与利用研究%Improved Water Conservation of Sand Land and its Utilization in Zhangwu County

    Institute of Scientific and Technical Information of China (English)

    焦树仁; 李春龙; 王宝泽; 佟威

    2015-01-01

    In order to improve water conservation and utilization of sand,the experimental demonstration zone in Aer Township of Zhangwu County in Liaoning Province was established.Result shows that:bulldozing dunes can improve the water condition of sand,increase the soil moisture content by 0.9%-1.3%,and expand the utilization area for sand land by 25%-30%;wells were made by using groundwater;a well is distributed every 3.3 hm2;the a-mount of water is seven tons per hour,which used for irrigating farmland,medicine garden,nursery and fast-grow-ing forest.Implementing micro-irrigation and laying underground pipe network can ensure the soil moist during the dry season,and can save water 2-3 times than that with irrigation pipe;using film bags planting and film planting method can save water about one time.%为了进行水利改良与利用沙地,在辽宁省彰武县阿尔乡建立了试验示范区。试验表明,推平沙丘,可以改善沙地水分状况,提高土壤含水率0.9%~1.3%,沙地利用面积扩大25%~30%;利用地下水,打机井,每3.3 hm2分布一眼,出水量每小时7 t,灌溉农田、药圃、苗圃和速生林;实施微润灌溉,铺设地下管网,保障在旱季土壤湿润,比管道灌水节水2~3倍;实行膜袋植树与覆膜植树法,可节水1倍左右。

  7. Seismic architecture and sedimentology of a major grounding zone system deposited by the Bjørnøyrenna Ice Stream during Late Weichselian deglaciation

    Science.gov (United States)

    Rüther, Denise Christina; Mattingsdal, Rune; Andreassen, Karin; Forwick, Matthias; Husum, Katrine

    2011-09-01

    A 280 km wide sediment wedge in outer Bjørnøyrenna (Bear Island Trough), south-western Barents Sea, has been investigated using 2D and 3D seismic data, sediment gravity cores, as well as regional swath and large scale bathymetry data. The bathymetry data indicate a division into an up to 35 m high frontal wedge with large depressions, and an upstream part characterized by mega scale glacial lineations (MSGL). From seismic sections increasing erosion is demonstrated for the upstream part, coinciding with the location of MSGL. Whether the latter are depositional features postdating an extensive erosional event or formed by erosion remains inconclusive. Based on the distinct morphology and internal structures, we infer that the system was deposited during a rapid readvance whereby the ice front pushed and bulldozed predominantly soft, diluted proglacial sediments. Analyses in the eastern part of the sediment system reveal the existence of imbricated thrust sheets in the frontal part of the wedge. This is suggested to imply upstream erosion of sedimentary rock and incorporation of thrusted blocks into the moraine, forming a composite ridge locally. We argue that observed large scale depressions are dead-ice features in the marine environment. It is envisioned that intense englacial thrusting may have developed into a decollement as the cold glacier snout got overrun by ice masses from the interior, thereby enabling the inclusion of slabs of ice in the push moraine mass. Radiocarbon dates indicate that the sediment wedge was deposited around 17,090 cal yrs BP (14,530 14C yrs BP) and that the ice front probably remained stable until 16,580 cal yrs BP (13,835 14C yrs BP).

  8. 基于定量分析的宁波市金融人才发展对策研究%A Quantitative Study on Policies to Cultivate Financial Professionals in Ningbo

    Institute of Scientific and Technical Information of China (English)

    朱丽萍; 余翔

    2015-01-01

    采用定量化方法对金融人才与金融业发展的相关性、金融人才缺口、学历和年龄结构对金融业发展影响分别进行分析,发现金融人才总量与金融业增加值高度正相关,宁波市 2020 年金融人才缺口将达2.5 万人,且高学历和年轻人才对金融业发展具有最大的推动作用.从人才规划、金融市场建设、人才政策、在职教育、学科建设和师资力量等方面提出若干加强金融人才队伍建设的措施.%This paper conducted a quantitative study to analyze the role of financial professional in financial development and factors of human resources shortage, educational experience and age structure that will impact the advance of financial industries. It found thatthe total pool of financial professionals and the added value of banking business are positively correlated, that young talents of higher degrees are bulldozers of financial development, and that there will be 25,000 financial professionals in need in Ningbo by 2020. And it put forward correspondent steps to strengthen the HR capacity-building of financial professionals in terms of long-term personnel pooling plan, banking market development, talents policies optimization, in-service education, financial disciplinary construction and faculty training.

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

    Science.gov (United States)

    Silliman, Brian R; McCoy, Michael W; Trussell, Geoffrey C; Crain, Caitlin M; Ewanchuk, Patrick J; Bertness, Mark D

    2013-01-01

    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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. Taku Glacier: Proglacial Deformation and Subglacial Erosion

    Science.gov (United States)

    Kuriger, E. M.; Motyka, R. J.; Truffer, M.; Bucki, A. K.

    2003-12-01

    Taku Glacier has advanced about 7~km since 1890 and is continuing its advance today. Located in southeastern Alaska, this glacier flows from the Juneau Ice Field down to sea level. In the last several decades the glacier has bulldozed a berm of marine and fluvial sediments from the fjord bottom; this berm now separates the terminus from tidewater. The force of the advancing glacier is causing large-scale deformation within these sediments. In 2001, a series of thrust scarps began to form in front of a 200~m section of the terminus. These scarps were active for several months and produced a series of bulges that grew to be several meters in height above the surrounding sediments. Ground penetrating radar (GPR) was used to image the internal structure of these bulges. A trench dug into one of the proglacial ridges revealed that a >2~m clay/sand layer might have played an important role as a thrust zone during deformation. This layer could also be identified in the GPR returns. Beside these scarp-formed bulges there are numerous indicators of the continued advance. Push moraines along the terminus range in height from 1~m to a towering 10~m. In some areas the advancing ice has dug into the sediments and has lifted the vegetation from below. We also observed up to 1~m thick debris freeze-on layers that, when exposed at the terminus, melt and contribute to the development of some moraines. In addition to these observations we performed a series of radio echo-soundings over a grid that extends about 5~km upglacier. These data are compared with depth measurements made in 1989. Since then the glacier has advanced about 180~m. Within 1~km of the present terminus the glacier has deepened its bed by about 15~m, which indicates an erosion rate of about 1~my-1 in this area. This rate agrees with the one observed over the past 100~years. Entrenchment plays an important role in the glacier's dynamics and needs to be taken into account when measuring volume changes.

  17. 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

  18. Linking the runoff response at micro-plot and catchment scale following wildfire and terracing, north-central Portugal

    Science.gov (United States)

    Martins, Martinho A. S.; Rial-Rivas, María E.; Machado, Ana I.; Serpa, Dalila; Prats, Sergio A.; Faria, Sílvia R.; Varela, María E. T.; González-Pelayo, Óscar; Keizer, J. Jacob

    2015-04-01

    Wildfires are known as one of the principal natural hazards affecting the Mediterranean region. This includes Portugal, where wildfires have affected some 100.000 ha of rural lands each year. The effects of wildfires on runoff generation and/or the associated soil (fertility) losses have been studied in Portugal for more than two decades. Some of these studies have reported strong and sometimes extreme hydrological responses in recently burnt areas. Forestry operations in such areas have increasingly come to include bench terracing in preparation of new eucalypt plantations. The hydrological impacts of bench terracing, however, have received little research attention so far and the few existing publications are limited to small spatial scales. The construction of terraces is commonly considered an effective practice for soil conservation on steep slopes, having been applied by mankind since early history. Nonetheless, the present authors have measured high rates of splash as well as inter-rill erosion on recently constructed terraces, and have regularly observed rill formation, including on forest tracks which typically constitute an extensive network in such bench terraced plantations. The present study was carried out in a 29-ha forest catchment in north-central Portugal that was burnt by a wildfire during the summer of 2010, logged during early winter 2010/11, and then bench terraced with bulldozers during late winter 2011, some 6 months after the wildfire. The catchment outlet was instrumented immediately after the fire with an automatic hydrometric station comprising two subsequent flumes with maximum discharge capacities of 120 and 1700 l sec-1. Within the catchment, rainfall was measured using several automatic and storage gauges and overland flow was monitored on two contrasting slopes using 3 micro-plots of approximately 0.25m2 on each slope.Overland flow was measured at 1- to 2-weekly intervals during the hydrological years of 2010/11 and 2011/12, i

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. TECTONIC POSITION OF MARBLE MELANGES IN THE EARLY PALEOZOIC ACCRETION-COLLISIONAL SYSTEM OF THE WESTERN PRIBAIKALIE

    Directory of Open Access Journals (Sweden)

    V. S. Fedorovsky

    2015-09-01

    Full Text Available The Early Paleozoic collisional system located in the Olkhon region at the western shores of Lake Baikal resulted from collision of the Siberian paleocontinent and a complex aggregate composed by fragments of a microcontinent, island arcs, back-arc structures and accretionary prisms. The main events were associated with complete manifestation of shear tectogenesis initiated by oblique collision. The current structure includes tectonically displaced components of ancient geodynamic systems that used to have been located dozens and hundreds of kilometres apart. Horizontal amplitudes of tectonic displacement seem to have been quite high; however, numerical data are still lacking to support this conclusion. Information about the structure of the upper crust in the Paleozoic is also lacking as only deep metamorphic rocks (varying from epidote-amphibolite to granulite facies are currently outcropped. Formations comprising the collisional collage are significantly different in composition and protoliths, and combinations of numerous shifted beds give evidence of a 'bulldozer' effect caused by the collisional shock followed by movements of crushed components of the ocean-continent zone along the margin of the Siberian paleocontinent. As evidenced by the recent cross-section, deep horizons of the Early Paleozoic crust comprise the collisional system between the Siberian craton and the Olkhon composite terrain. A permanent inclusion in the collisional combinations of rocks are unusual synmetamorphic injected bodies of carbonate rocks. Such rocks comprise two groups, marble melanges and crustal carbonate melted rocks. Obviously, carbonate rocks (that composed the original layers and horizons of stratified beds can become less viscous to a certain degree at some locations during the process of oblique collision and acquire unusual properties and can thus intrude into the surrounding rocks of silicate composition. Such carbonate rocks behave as protrusions

  8. 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

  9. Vegetation Response to the 1995 Drawdown of the Navigation Pool at Felsenthal National Wildlife Refuge, Crossett, Arkansas

    Science.gov (United States)

    Howard, Rebecca J.; Wells, Christopher J.

    2007-01-01

    Felsenthal Navigation Pool (?the pool?) at Felsenthal National Wildlife Refuge near Crossett, Ark., was continuously flooded to a baseline elevation of 19.8 m (65.0 ft) mean sea level (m.s.l.) from late fall 1985, when the final in a series of locks and dams was constructed, until the summer of 1995. Water level within the pool was reduced by 0.3 m (1.0 ft) beginning July 5, 1995, exposing about 1,591 ha (3,931 acres) of sediment; the reduced water level was maintained until October 25 of that year. A total of 15 transects was established along the pool margin before the drawdown, extending perpendicular from the pool edge to 19.5 m (64.0 ft) in elevation. Plant species composition and cover were recorded at six to seven quadrats on each transect; 14 of the transects were also monitored three times during the drawdown and in June 1996. Soil near five of the original transects was disturbed two weeks into the drawdown by scraping the soil surface with a bulldozer. Soil cores were collected to characterize soil organic matter, texture class, carbon and nitrogen content, and plant nutrient concentrations; soil samples were also collected to identify species present in the seed bank prior to and during the drawdown. Plant species, several of which were high quality food sources for waterfowl, colonized the drawdown zone within four weeks. Vegetation response, measured by species richness, total cover, and cover of Cyperus species, was often greater at low compared to high elevations in the drawdown zone; this effect was probably intensified by low rainfall during the summer of 1995. Vegetation response on the disturbed transects was reduced compared to that on the undisturbed transects. This effect was attributed to two factors: (1) removal of the existing seed bank by the disturbance technique applied and (2) reduced incorporation of seeds recruited during the drawdown because of unusually low summer rainfall. Seed bank studies demonstrated that several species

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 基于QFD的工程机械维修性设计要求分析%Design Requirements for Construction Machinery Maintainability Based on QFD

    Institute of Scientific and Technical Information of China (English)

    郭鹏飞; 郑怀洲; 于春风; 赵永朋

    2011-01-01

    The design for maintainability is important in the construction machinery, and the identification of the design requirements of construction machinery maintainability is the pre-requirement. Firstly, the paper briefly discusses the QFD method, especially, the basic makeup of HoQ. Secondly, the analysis process of the design requirements of construction machinery maintainability based on QFD is discussed, mainly including six steps: analyzing the clients' maintainable requirements, evaluating the weight of each requirement, determining the design index of maintainability, constructing the design index matrix, constructing the design index and maintainable requirements matrix, and forming the design index weight matrix of maintainability. Lastly, through analyzing the design requirements of one bulldozer maintainability based QFD, the importance sequence of maintainability design indexes is obtained, as in the order: the disassembly-assembly character, the modularization, the standardization, the compactness, the accessability and the easiness to identify. It is shown that the analysis of design requirements of construction machinery maintainability based on QFD can effectively solve the problems of complexity and uncertainty in the analysis process and evaluate the design requirements of maintainability by integrating qualitative analysis with quantitative analysis, with a high practical value.%维修性设计是工程机械研究阶段必须开展的一项重要工程活动,而维修性设计要求的提出与确定又是后续各项维修性工作的前提与基础.简要介绍了质量功能展开(QFD)方法,重点论述了质量屋(HoQ)的基本构成;探讨了基于QFD的工程机械维修性设计要求分析过程,主要包括提出客户维修需求、确定维修需求权重、提出维修性设计指标、构造设计指标关系矩阵、构造设计指标——维修需求关系矩阵和得出维修性设计指标权重矩阵6个步骤.最后,通过运

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. Optimal design for cone valve of mechanical-hydraulic dual power engine%机械-液压双元动力发动机锥形配流阀的优化

    Institute of Scientific and Technical Information of China (English)

    霍炜; 张纪鹏; 张洪信; 张铁柱

    2013-01-01

    机械-液压双元动力输出发动机(MHPE)将传统的内燃机和柱塞泵融为一体,可同时或单独输出机械、液压2种动力。MHPE采用锥形阀配流系统,其容积效率高低直接影响MHPE的整机性能。该文以容积效率为目标函数,以锥形阀的工作条件和结构尺寸为约束条件,以MHPE锥形阀的结构参数为优化变量,建立了优化模型,并基于iSIGHT软件进行优化设计。优化结果表明,优化后系统的容积效率提高5.71%,改善程度较大。%Heat energy can be converted to hydraulic energy by a traditional engine-pump system(EPS). However, the EPS has some disadvantages, such as a long transmission line, low efficiency, and a complex and heavy structure. With an integrating traditional internal combustion engine and plunger pump to remove intermediate links, a mechanical-hydraulic dual power engine (MHPE) can convert heat energy to hydraulic energy directly. Therefore, the energy conversion efficiency was improved and the structure was simplified. MHPE can output one of or both machinery and hydraulic powers, and it can be used for excavators, loaders, bulldozers, and other engineering machineries. The distribution valve, the important element of MHPE, can affect the volume efficiency of the system directly by its structure and performance. The 36114ZG4B type six-cylinders radial MHPE was developed. A-H20L type one-way cone valve with the valve disk of 0.07557 kg quality, 0.028 m large diameter, 0.021 m small diameter and 40° angle is used as an inlet valve. A DIF-L20H type one-way cone valve with the valve disk of 0.04672 kg quality, 0.021 m large diameter, 0.016 m small diameter and 45° angle was used as an outlet valve. With the volume efficiency taken as an objective function, the cone valve’s working conditions and structure dimensions taken as constraint conditions, and the cone valve’s structure parameters taken as optimization variables, an optimization model

  2. 孤立性纤维瘤的影像学分析

    Institute of Scientific and Technical Information of China (English)

    陈建初; 李子平; 刘红艳; 黄奕妆; 王承光; 黄海连; 赖碧玉

    2015-01-01

    analyzed. all of 10cases underwent spiral CT plain and contrast enhanced scans, All of 10 cases underwent multi-planar reformatting(MPR )(coronal and sagital reformatting),2 cases underwent MR plain scans and contrast enhanced scans. we analysis all the images and study the imagingfindings of CT/MR.Results 8 cases SFT located in pleura cavity,1 case SFT rode across chest and abdomen,1 case SFT located in Upper neck and intracranial,performing as mass formed with communication. The small SFT (<10cm)inpleura cavity can be taken apart from the lung and the lung may be bulldozed;the large SFT (≥10cm) may be combined to the lung ,and we can’t distinguish the tumor from the lung. Sources of pleural SFT CT scan showed homogeneous or slightly inhomogeneous soft tissue mass, enhanced scan lesions showed heterogeneous enhancement, showing maps like enhancement, irregular necrotic lesions larger visible area. Extra pleural (mediastinum、 head and neck) SFT show the large soft tissue mass, growing more slowly, often relatively weak growth in the gap, push or invasion of adjacent organs. Unenhanced MRI T1WI as other signal, T2WI high signal is inhomogeneous, FS-T2WI showed heterogeneous mixed high signal, DWI showed low signal lesions significantly enhanced scan heterogeneous enhancement, peripheral enhancement slightly obvious.Conclusion SFT occur in the pleural cavity, expressed as an isolated soft tissue mass, wide base, and the boundary more clearly, pushing adjacent lung tissue,with the rich blood supply, no hilar, mediastinal, axillary lymph nodes; Mediastinum and head and neck can be the diseased parts of extrapleural SFT, tumor growth gap or weakness in the muscular gap, rich blood supply, significantly enhanced. Lesions greater than 10cm, inhomogeneous enhancement (with necrosis), malignancy may invade surrounding tissues.

  3. 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!

  4. 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.

  5. Rubber Tree Bark Necrosis: advances in symptomatology, etiology, epidemiology and causal factors of a physiological trunk disease%橡胶树树皮坏死:症状学、病原学、流行病学方面的发展和树干生理病症的发因

    Institute of Scientific and Technical Information of China (English)

    D. Nandris; R. Moreau; F. Pellegrin; H. Chrestin

    2005-01-01

    方法为由协迫诱导的多因素生理病害研究提供了一个完整的新模式.%The main constraint in rubber plantations worldwide is the cessation of latex production caused by twodifferent syndromes: (i) Tapping Panel Dryness (TPD) as a reversible physiological response to overexploitation; and(ii) Bark Necrosis (BN), an irreversible syndrome of the phloem that spreads from the collar.Bark Necrosis (BN) now affects most modern rubber plantations worldwide, with a wide range of severity acrosssites depending on the clone, the age of the trees, the site and the country. The controversial polymorphism of barksyndromes was recently settled thanks to surveys made in a large number of rubber plantations. While previous andrecent etiological analyses remain non-conclusive, environmental factors were shown to be associated with BN. Indeed,epidemiological surveys on recently tapped blocks revealed a non-random location of the earliest diseased trees. Theserisk areas are mainly characterized by the proximity of a swamp, plantation road, windrow, old bulldozer track, residualforest stump or slope break. In BN emergence areas, while no significant correlation was found with chemical soilparameters, physical soil analyses (e.g. penetrometry) revealed higher soil compaction, often associated with poorerrhizogenesis in BN trees. Complementary, initial BN symptoms were preferentially observed near the grafied bud at therootstock/scion junction (RS/S). Numerous comparative ecophysiological measurements using a PMS pressure chamberindicated water stress in BN trees. These results suggested a non-optimal vascular relation between the root system andthe trunk of BN trees. Thus, compaction-associated reduced water availability of the soil, poor root capacity to meet thewater demand during drier dry seasons, combined with disturbed sap flows and recurrent local water drainage) are nowsuspected to jointly act as the main exogenous causal stresses that induce the BN process at