Parameterizing road construction in route-based road weather models: can ground-penetrating radar provide any answers?

International Nuclear Information System (INIS)

Hammond, D S; Chapman, L; Thornes, J E

2011-01-01

A ground-penetrating radar (GPR) survey of a 32 km mixed urban and rural study route is undertaken to assess the usefulness of GPR as a tool for parameterizing road construction in a route-based road weather forecast model. It is shown that GPR can easily identify even the smallest of bridges along the route, which previous thermal mapping surveys have identified as thermal singularities with implications for winter road maintenance. Using individual GPR traces measured at each forecast point along the route, an inflexion point detection algorithm attempts to identify the depth of the uppermost subsurface layers at each forecast point for use in a road weather model instead of existing ordinal road-type classifications. This approach has the potential to allow high resolution modelling of road construction and bridge decks on a scale previously not possible within a road weather model, but initial results reveal that significant future research will be required to unlock the full potential that this technology can bring to the road weather industry. (technical design note)

Environmentally friendly road construction

Directory of Open Access Journals (Sweden)

A.I. Essawy

2013-06-01

Full Text Available Environmental pollution is a major problem in developing countries like Egypt. Reuse of waste polymers is considered an attractive solution for environmental white pollution and reducing of the costs of road pavement and maintenance. This research aims to prepare environmentally friendly hot mix asphalt (HMA for paving using some industrial wastes as polypropylene and polyester fibers. The solid materials in the mix include normal and highly porous aggregates. 5% and 10% of waste polymers by weight of the asphalt were used to prepare special binders. The samples were tested for their physical properties, chemical properties, aging, scanning electron microscopy (SEM and thermo-gravimetric analysis (TGA. The results revealed that the prepared HMA using 5% of waste polymer had high performance as compared to the ordinary one and the waste polymer could be used in road construction.

Cost diviation in road construction projects: The case of Palestine

Directory of Open Access Journals (Sweden)

Ibrahim Mahamid

2012-02-01

Full Text Available This paper investigates the statistical relationship between actual and estimated cost of road construction projects using data from road construction projects awarded in the West Bank in Palestine over the years 2004–2008. The study is based on a sample of 169 road construction projects. Based on this data, regression models are developed. The findings reveal that 100% of projects suffer from cost diverge, it is found that 76% of projects have cost under estimation while 24% have cost over estimation. The discrepancy between estimated and actual cost has an average of 14.6%, ranging from -39% to 98%. The relation between the project size (length and width and the cost diverge is discussed.

IMPLEMENTATION OF THE CONCEPT OF AUTOMATION AND INTELLECTUALIZATION OF MANAGEMENT OF ROAD CONSTRUCTION PROCESSES

Directory of Open Access Journals (Sweden)

Ivanchura Vladimir Ivanovich

2018-02-01

Full Text Available Subject: management of operating modes of road-building machines, taking into account the implementation of the concept of information modeling of the road. We have reviewed the status and the development problems for directions of improving the control systems of road-construction machine processes. In this work we focus on the road construction stage “laying asphalt-concrete - compaction”, the effective control of which can lead to significant improvement in the quality of road surfaces, increase of durability and reduction of defects in pavements. Research objectives: rationale and directions of realization of the concept of intellectualization of the road construction management. Materials and methods: analysis of the shortcomings of construction of asphalt-concrete pavements, analysis of the methods of workflow management of road-building machines. Results: we have substantiated the methodological background for the development of intellectual control systems of road-building machines. Conclusions: we considered possible ways of introducing the concept of intellectualization of management systems for road-building machines.

Recycling of waste spent catalyst in road construction and masonry blocks.

Science.gov (United States)

Taha, Ramzi; Al-Kamyani, Zahran; Al-Jabri, Khalifa; Baawain, Mahad; Al-Shamsi, Khalid

2012-08-30

Waste spent catalyst is generated in Oman as a result of the cracking process of petroleum oil in the Mina Al-Fahl and Sohar Refineries. The disposal of spent catalyst is of a major concern to oil refineries. Stabilized spent catalyst was evaluated for use in road construction as a whole replacement for crushed aggregates in the sub-base and base layers and as a partial replacement for Portland cement in masonry blocks manufacturing. Stabilization is necessary as the waste spent catalyst exists in a powder form and binders are needed to attain the necessary strength required to qualify its use in road construction. Raw spent catalyst was also blended with other virgin aggregates, as a sand or filler replacement, for use in road construction. Compaction, unconfined compressive strength and leaching tests were performed on the stabilized mixtures. For its use in masonry construction, blocks were tested for unconfined compressive strength at various curing periods. Results indicate that the spent catalyst has a promising potential for use in road construction and masonry blocks without causing any negative environmental impacts. Copyright © 2012 Elsevier B.V. All rights reserved.

Towards high-performance materials for road construction

Science.gov (United States)

Gladkikh, V.; Korolev, E.; Smirnov, V.

2017-10-01

Due to constant increase of traffic, modern road construction is in need of high-performance pavement materials. The operational performance of such materials can be characterized by many properties. Nevertheless, the most important ones are resistance to rutting and resistance to dynamical loads. It was proposed earlier to use sulfur extended asphalt concrete in road construction practice. To reduce the emission of sulfur dioxide and hydrogen sulfide during the concrete mix preparation and pavement production stages, it is beneficial to make such a concrete on the base of complex sulfur modifier. In the present work the influence of the complex modifier to mechanical properties of sulfur extended asphalt concrete was examined. It was shown that sulfur extended asphalt concrete is of high mechanical properties. It was also revealed that there as an anomalous negative correlations between strain capacity, fatigue life and fracture toughness.

Natural road construction materials of Southern Africa

CSIR Research Space (South Africa)

Weinert, HH

1980-01-01

Full Text Available respectively. p. 210. column 4: Insert Notre in rect311glc directly below heading Matrix. p. 240, paragraph 5, line 4: J 770 should read I 700. I ~I -~ r THE NATURAL ROAD CONSTRUCTION MATERIALS OF SOUTHERN AFRICA ACADEMICA I PRETORIA ICAPE TOWN ISBN... and the author acknowledges gratefully the valuable assistance and the trouble taken by the following persons: Southern African road authorities: Mr W. J. Biesenbach, Mr H. K. Geel, Mr C. L. Laubscher, Mr G. P. Marais, Mr R. L. Mitchell, Mr I. P. A. Smit, Mr C...

Assessing Environmental Impact Indicators in Road Construction Projects in Developing Countries

Directory of Open Access Journals (Sweden)

Mohamed Marzouk

2017-05-01

Full Text Available Environmental pollution is considered to be one of the main concerns in the construction industry. Environmental pollution has become a major challenge to construction projects due to the huge amount of pollution caused by construction projects. There are different types of environmental impact indicators, such as the greenhouse gas (GHG footprint, eutrophication potential (EP, acidification potential (AP, human health (HH particulate, ozone depletion, and smog. Each of these environmental impact indicators can be linked to different phases of the construction projects. The overall environmental impact indicators can be divided into direct, indirect, and operational emissions. This paper presents a Building Information Modeling (BIM-based methodology for the assessment of environmental impacts in road construction projects. The model takes into account the overall life cycle of the road construction project, which is divided into: manufacturing phase, transportation phase, construction phase, maintenance phase, operational phase, recycling phase, and deconstruction phase. A case study is presented to demonstrate the applicability of the proposed model. The proposed model solves a major problem for road construction project teams who want to assess the environmental impact indicators associated with their project prior to the start of the execution of their projects.

36 CFR 223.84 - Small business bid form provisions on sales with specified road construction.

Science.gov (United States)

2010-07-01

... provisions on sales with specified road construction. 223.84 Section 223.84 Parks, Forests, and Public... specified road construction. For each sale described in § 223.82(b), the bid form must include provision for a small business concern: (a) To elect road construction by the Forest Service and where such...

Leaching behaviour of copper slag, construction and demolition waste and crushed rock used in a full-scale road construction.

Science.gov (United States)

Lidelöw, Sofia; Mácsik, Josef; Carabante, Ivan; Kumpiene, Jurate

2017-12-15

The leaching behaviour of a road construction with fayalitic copper slag, recycled concrete and crushed rock as sub-base materials was monitored over ten years. All studied materials used in the road construction, including crushed rock, contained concentrations of several elements exceeding the guideline values recommended by the Swedish EPA for total element concentrations for waste materials used in constructions. Despite that, leaching from the road construction under field conditions in general was relatively low. The leachates from the recycled materials contained higher concentrations of several constituents than the leachates from the reference section with crushed rock. The leaching of the elements of interest (Cr, Mo, Ni, Zn) reached peak concentrations during the second and fourth (Cu) years and decreased over the observation period to levels below the Swedish recommended values. Carbonation of the concrete aggregates caused a substantial but short-term increase in the leaching of oxyanions such as chromate. The environmental risks related to element leaching are highest at the beginning of the road life. Ageing of materials or pre-treatment through leaching is needed prior to their use in construction to avoid peak concentrations. Also, the design of road constructions should be adjusted so that recycled materials are covered with low-permeability covers, which would minimize the exposure to atmospheric precipitation and weathering. Copyright © 2017 Elsevier Ltd. All rights reserved.

Logistics Solution for Choosing Location of Production of Road Construction Enterprise

Science.gov (United States)

Gavrilina, I.; Bondar, A.

2017-11-01

The current state of construction of highways indicates that not all the resources of the construction organization are implemented and supported by the modern approaches in logistics problems solving. This article deals with the solution of these problems and considers the features of basic road linear works organization, their large extent and different locations of enterprises. Analyzing these data, it is proposed to simulate the logistics processes and substantiate the methods of transport operations organizing by linking the technology and the organization road construction materials delivery which allows one to optimize the construction processes, to choose the most economically advantageous options, and also to monitor the quality of work.

Construction demolition wastes, Waelz slag and MSWI bottom ash: a comparative technical analysis as material for road construction.

Science.gov (United States)

Vegas, I; Ibañez, J A; San José, J T; Urzelai, A

2008-01-01

The objective of the study is to analyze the technical suitability of using secondary materials from three waste flows (construction and demolition waste (CDW), Waelz slag and municipal solid waste incineration (MSWI) bottom ash), under the regulations and standards governing the use of materials for road construction. A detailed technical characterization of the materials was carried out according to Spanish General Technical Specifications for Road Construction (PG3). The results show that Waelz slag can be adequate for using in granular structural layers, while CDW fits better as granular material in roadbeds. Likewise, fresh MSWI bottom ash can be used as roadbed material as long as it does not contain a high concentration of soluble salts. This paper also discusses the adequacy of using certain traditional test methods for natural soils when characterizing secondary materials for use as aggregates in road construction.

Hygienic assessment of using rocks with high content of natural radionuclides in road construction

International Nuclear Information System (INIS)

Kornilov, A.N.; Ryabchikov, S.G.

1983-01-01

Experimental investigations on radiation hygienic assessment of the possibilities of using rocks with an increased content of natural radionuclides (NRN) are carried out. At experimental road portions constructed using such rocks, γ-radiation levels have been measured and radioactive contamination of the ad-- jacent territory has been determined. The danger presented by such roads for highway engineering workers and population also has been assessed. The results obtained permit to express a possitive opinion on the use of solid wastes with an increased NRN content for construction of roads with asphalt coating. Rocks with specific α-activity 3 Bq/kg are recommended to be used for any types of road construction, whereas wastes with specific α-activity 3 Bq/kg - only for road construction in an industrial zone, between populated areas and for thoroughfares and highways. The use of wastes with a higher NRN content is unreasonable as it leads to a growth of annular dose to population and excessive exposure of construction workers engaged in highway engineering operations

Construction of road network vulnerability evaluation index based on general travel cost

Science.gov (United States)

Leng, Jun-qiang; Zhai, Jing; Li, Qian-wen; Zhao, Lin

2018-03-01

With the development of China's economy and the continuous improvement of her urban road network, the vulnerability of the urban road network has attracted increasing attention. Based on general travel cost, this work constructs the vulnerability evaluation index for the urban road network, and evaluates the vulnerability of the urban road network from the perspective of user generalised travel cost. Firstly, the generalised travel cost model is constructed based on vehicle cost, travel time, and traveller comfort. Then, the network efficiency index is selected as an evaluation index of vulnerability: the network efficiency index is composed of the traffic volume and the generalised travel cost, which are obtained from the equilibrium state of the network. In addition, the research analyses the influence of traffic capacity decrease, road section attribute value, and location of road section, on vulnerability. Finally, the vulnerability index is used to analyse the local area network of Harbin and verify its applicability.

25 CFR 163.30 - Revocable road use and construction permits for removal of commercial forest products.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Revocable road use and construction permits for removal... Revocable road use and construction permits for removal of commercial forest products. (a) In accordance... revocable road use and construction permits to users for the purpose of removing forest products. (b) When a...

Bio fuel ash in a road construction: impact on soil solution chemistry.

Science.gov (United States)

Thurdin, R T; van Hees, P A W; Bylund, D; Lundström, U S

2006-01-01

Limited natural resources and landfill space, as well as increasing amounts of ash produced from incineration of bio fuel and municipal solid waste, have created a demand for useful applications of ash, of which road construction is one application. Along national road 90, situated about 20 km west of Sollefteå in the middle of Sweden, an experiment road was constructed with a 40 cm bio fuel ash layer. The environmental impact of the ash layer was evaluated from soil solutions obtained by centrifugation of soil samples taken on four occasions during 2001-2003. Soil samples were taken in the ash layer, below the ash layer at two depths in the road and in the ditch. In the soil solutions, pH, conductivity, dissolved organic carbon (DOC) and the total concentration of cations (metals) and anions were determined. Two years after the application of the ash layers in the test road, the concentrations in the ash layer of K, SO4, Zn, and Hg had increased significantly while the concentration of Se, Mo and Cd had decreased significantly. Below the ash layer in the road an initial increase of pH was observed and the concentrations of K, SO4, Se, Mo and Cd increased significantly, while the concentrations of Cu and Hg decreased significantly in the road and also in the ditch. Cd was the element showing a potential risk of contamination of the groundwater. The concentrations of Ca in the ash layer indicated an ongoing hardening, which is important for the leaching rate and the strength of the road construction.

Common risks affecting time overrun in road construction projects in Palestine: Contractors’ perspective

Directory of Open Access Journals (Sweden)

Ibrahim Mahamid

2013-06-01

Full Text Available The construction sector is one of the key economic sectors and is the main force motivating the Palestinian national economy. However, it suffers from number of problems that affect time, cost and quality performances. This study aims at identifying the common risks affecting time overrun in road construction projects in the West Bank in Palestine from contractors’ viewpoint. 45 factors that might cause delays of road construction projects were defined through a detailed literature review. A questionnaire survey was performed to rank the considered factors in terms of severity and frequency. The analysis of the survey indicated that the top risks affecting time overrun in road construction projects in Palestine are: financial status of the contractors, payments delay by the owner, political situation, segmentation of the West Bank, poor communication between construction parties, lack of equipment efficiency, and high competition in bids.

Quality of road construction projects in Sweden between 1990 and 2010

Directory of Open Access Journals (Sweden)

Abukar Warsame

2014-03-01

Full Text Available It has been reported that productivity developments in construction are slow compared to other sectors. Measuring productivity is however not easy and it might have been underestimated due to deficiencies in the index that is used when the value added in current prices is converted into value added at constant prices. A central problem when deflating nominal prices is that the deflation should only take away price changes for identical products and not price changes related to quality changes and improvements necessitated by new environmental conditions and legislation as well as demand for higher safety. The aim of this project is to help fill this gap by looking at the quality changes over time in road construction. A combination of comparative studies and interviews with practitioners from public and private sectors that are involved in road construction projects were conducted. It was found that there had been both direct quality changes in the roads, primarily to improve safety on the roads and for noise protection, and indirect quality changes related to building in more difficult circumstances because of giving higher weight to other social objectives, especially environmental objectives. As these quality increases are not taken into account when productivity is measured, productivity improvements could be underestimated by around 1% per year.

The assessment of environmentally sensitive forest road construction in Calabrian pine forest areas of Turkey.

Science.gov (United States)

Tunay, Metin

2006-07-01

Forest road construction by bulldozers in Calabrian Pine (Pinus brutia Ten.) forests on mountainous terrain of Turkey causes considerable damage to the environment and the forest standing alongside the road. This situation obliges a study of environmentally sound road construction in Turkey. This study was carried out in 4 sample sites of Antalya Forest Directorate in steep (34-50% gradient) and very steep terrain (51-70% gradient) conditions with bulldozer and excavator machine and direct damages to forest during road construction was determined, including forest area losses and damages to downhill trees in mountainous areas. It was determined that in steep terrain when excavators were used, less forest area (22.16%) was destroyed compared to bulldozers and 26.54% less area in very steep terrain. The proportion of damage on trees where bulldozer worked was nearly twofold higher than excavator was used. The results of this research show that the environmentally sensitive techniques applied for the road construction projects are considerably superior to the traditional use of bulldozers on steep slopes. The environmentally sound forest road construction by use of excavator must be considered an appropriate and reliable solution for mountainous terrain where areas of sensitive forest ecosystems are to be opened up.

PROSPECTS FOR APPLICATION OF COMPLEX-MODIFIED SAND ASPHALT CONCRETE IN ROAD CONSTRUCTION

Directory of Open Access Journals (Sweden)

D. Yu. Alexandrov

2017-01-01

Full Text Available The paper considers a possibility to use sand asphalt concrete as a material for protection of asphalt concrete and cement concrete road pavements against affection of external destructive factors. Advantages and disadvantages of sand asphalt concrete road pavements have been determined in the paper. The paper provides recommendations on improvement of sand asphalt concrete properties and contains an analysis of possible variants for usage of complex-modified sand asphalt concrete in the road construction. It has been noted that according to its potentially possible physical and mechanical properties activated quartz sand being micro-reinforced by dispersive industrial wastes is considered as an efficient component for creation of constructive layers in road asphalt concrete pavements. The paper reveals only specific aspects of the efficient application of quartz sand in road asphalt concrete. The subject of the paper loоks rather interesting for regions where there are no rock deposits for obtaining broken-stone ballast but there is rather significant spreading of local quarts sand. Its successful application is connected with the necessity to develop special equipment for physical and chemical activation of sand grain surface that permits strongly to increase an adhesive strength in the area of phase separation within the “bitumen–SiO2” system. The considered problem is a topical one and its solution will make it possible to local sand in a maximum way and partially to exclude application of broken stone in road construction.

Some problems for natural radiation impact assessment in road construction

International Nuclear Information System (INIS)

Li Xutong; Chen Xiaoqiu; Li Yuanxin

2002-01-01

Some instances have occurred for that road constructions were likely to meet with some high grade uranium mine in some provinces with abundant uranium resource and developed economy. Some of the constructions have made assessment for the radiation risk. The author discusses the problems existent in the assessments

Use of oil shale ash in road construction: results of follow-up environmental monitoring.

Science.gov (United States)

Reinik, Janek; Irha, Natalya; Koroljova, Arina; Meriste, Tõnis

2018-01-05

Oil shale ash (OSA) was used for road construction in a pristine swamp area in East-Estonia during 2013-2014. OSA was used as a binder both in mass stabilization of soft peat soil and in the upper layer. Use of OSA in civil engineering always raises questions about the environmental safety of such activities. Post-construction environmental monitoring of the pilot section was carried out in 2014 and 2015. The monitoring program involved surface water and soil sampling campaigns. Samples were analyzed for selected constituents and parameters of environmental concern. The paper gives data for assessing the environmental impact and evaluation of potential risks associated with construction of roads using OSA. Leaching of hazardous compounds from the pilot section to surrounding aqueous environment was not observed during the monitoring program. Still, the road construction affected the concentration of sulfates in surrounding surface water. Also, the water-soluble content of barium in surface water correlated significantly with the concentrations of chloride and sulfate ion and electric conductivity of the surface water. Therefore, it is recommended to monitor the electric conductivity, concentrations of sulfates, chlorides, and barium in nearby surface water when OSA is used in road construction.

Literature review of levels and determinants of exposure to potential carcinogens and other agents in the road construction industry.

Science.gov (United States)

Burstyn, I; Kromhout, H; Boffetta, P

2000-01-01

Workers in the road construction industry include asphalt plant, ground construction, and road paving workers. These individuals can be exposed to a wide range of potentially hazardous substances. A summary of levels of exposure to different substances measured during road construction is presented. In modern road paving, workers typically are exposed to 0.1 to 2 mg/m3 of bitumen fume, which includes 10 to 200 ng/m3 of benzo(a)pyrene. Sampling strategies and analytical methods employed in each reviewed survey are described briefly. The published reports provide some insight into the identity of factors that influence exposure to bitumen among road construction workers: type of work performed, meteorological conditions, temperature of paved asphalt. However, there is a lack of (a) comprehensive and well-designed studies that evaluate determinants of exposure to bitumen in road construction, and (b) standard methods for bitumen sampling and analysis. Information on determinants of other exposures in road construction is either absent or limited. It is concluded that data available through published reports have limited value in assessing historical exposure levels in the road construction industry.

Solidification/stabilization of dredged marine sediments for road construction.

Science.gov (United States)

Wang, Dong Xing; Abriak, Nor Edine; Zentar, Rachid; Xu, WeiYa

2012-01-01

Cement/lime-based solidification is an environmentally sound solution for the management of dredged marine sediments, instead of traditional solutions such as immersion. Based on the mineralogical composition and physical characteristics of Dunkirk sediments, the effects of cement and lime are assessed through Atterberg limits, modified Proctor compaction, unconfined compressive strength and indirect tensile strength tests. The variation of Atterberg limits and the improvement in strength are discussed at different binder contents. The potential of sediments solidified with cement or lime for road construction is evaluated through a proposed methodology from two aspects: I-CBR value and material classification. The test results show the feasibility of solidified dredged sediments for beneficial use as a material in road construction. Cement is superior to lime in terms of strength improvement, and adding 6% cement is an economic and reasonable method to stabilize fine sediments.

Influence of low impact development construction on pollutant process of road-deposited sediments and associated heavy metals.

Science.gov (United States)

Ma, Yukun; Gong, Manli; Zhao, Hongtao; Li, Xuyong

2018-02-01

Intense Low-Impact Development (LID) construction in China could lead to increasingly severe stormwater and receiving water pollution due to the lack of appropriate regulation for mitigating pollution from LID construction. Samples of road-deposited sediments (RDS) were collected from 50 study sites at seven LID construction stages and four road hierarchies to analyze the pollution process and determine the size of the region influenced by LID construction. Six heavy metals were analyzed, and the RDS index model was adopted to estimate the potential heavy metal load washed off by stormwater runoff. Analysis of variance revealed that the excavation and gravel filling of rain gardens and excavation of porous pavements were critical LID construction stages that contributed the largest masses of RDS per unit area to road surfaces. Although the concentration of heavy metals at LID construction sites was lower than at sites without LID construction, the load of heavy metals washed off from LID construction was much higher. In addition, the sizes of regions influenced by accumulated RDS from LID construction descended in the following order: arterial road (600-775m)>collector road (150-200m)>access road (100-150m)>laneway (20-30m). According to the characteristics of LID construction at the study sites, the potential total solid loads in stormwater throughout China were estimated to reach 36,694t by 2020 and 146,777t by 2030. According to the results of analysis, several recommendations are provided for designing LID construction regulations to mitigate stormwater pollution. Copyright © 2017 Elsevier B.V. All rights reserved.

Traffic condition with road upgrading during construction and operation stages based on level-of-service (LOS)

Science.gov (United States)

Tay, A. C.; Lee, H. H.

2018-04-01

In this study, traffic survey was done at signalized intersection of both ends of an upgrading road during morning and afternoon peak hours throughout construction period. The intersections of Tudan Road located at Miri City in Sarawak State, Malaysia were chosen as study sites. The aim of this research was to investigate the traffic condition for the signalized intersections of a R3 secondary road that being upgrading to standard U5 dual carriageway during peak hours for construction and operation stages. Data collected from these sites were analyzed according to Highway Capacity Manual (HCM) 2010. From the results, the level-of-services (LOS) of Kuala Baram By Pass Road intersection improved from Level F to Level E at operation stage for weekday during peak hours in the morning. LOS of Lutong-Kuala Baram Road intersection at construction stage were Level C during peak hours in the morning and Level D during peak hours in the afternoon for weekends. However, the LOS during both peak hours for weekends were projected to improve to Level B at the operation stage. It proved that the road construction has affected LOS, and this temporary issue can be solved after the upgraded road is in operation.

Methodology for construction compliance monitoring in the crediting of investment projects for road construction

Science.gov (United States)

Vaynshtok, Natalia

2017-10-01

The article provides the results of development of the methodology for construction compliance monitoring in the crediting of investment projects for road construction. Work scope analysis of construction audit was conducted and an algorithm of financial audit in the crediting investment projects was developed. Furthermore, the possible pitfalls and abuses of counterparties were investigated and recommendations were given allowing the bank to receive objective and independent information on the progress of the project in real time. This mechanism is useful for the bank in insurance of possible risks, targeted and rational use of credit funds.

Early cost estimating for road construction projects using multiple regression techniques

Directory of Open Access Journals (Sweden)

Ibrahim Mahamid

2011-12-01

Full Text Available The objective of this study is to develop early cost estimating models for road construction projects using multiple regression techniques, based on 131 sets of data collected in the West Bank in Palestine. As the cost estimates are required at early stages of a project, considerations were given to the fact that the input data for the required regression model could be easily extracted from sketches or scope definition of the project. 11 regression models are developed to estimate the total cost of road construction project in US dollar; 5 of them include bid quantities as input variables and 6 include road length and road width. The coefficient of determination r2 for the developed models is ranging from 0.92 to 0.98 which indicate that the predicted values from a forecast models fit with the real-life data. The values of the mean absolute percentage error (MAPE of the developed regression models are ranging from 13% to 31%, the results compare favorably with past researches which have shown that the estimate accuracy in the early stages of a project is between ±25% and ±50%.

25 CFR 170.405 - Can tribal transportation planning funds be used for road construction and other projects?

Science.gov (United States)

2010-04-01

... INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Planning, Design, and Construction of Indian... funds be used for road construction and other projects? Yes, any tribe can request to have its planning... 25 Indians 1 2010-04-01 2010-04-01 false Can tribal transportation planning funds be used for road...

Quantitative Decision Making Model for Carbon Reduction in Road Construction Projects Using Green Technologies

Directory of Open Access Journals (Sweden)

Woosik Jang

2015-08-01

Full Text Available Numerous countries have established policies for reducing greenhouse gas emissions and have suggested goals pertaining to these reductions. To reach the target reduction amounts, studies on the reduction of carbon emissions have been conducted with regard to all stages and processes in construction projects. According to a study on carbon emissions, the carbon emissions generated during the construction stage of road projects account for approximately 76 to 86% of the total carbon emissions, far exceeding the other stages, such as maintenance or demolition. Therefore, this study aims to develop a quantitative decision making model that supports the application of green technologies (GTs to reduce carbon emissions during the construction stage of road construction projects. First, the authors selected environmental soundness, economic feasibility and constructability as the key assessment indices for evaluating 20 GTs. Second, a fuzzy set/qualitative comparative analysis (FS/QCA was used to establish an objective decision-making model for the assessment of both the quantitative and qualitative characteristics of the key indices. To support the developed model, an expert survey was performed to assess the applicability of each GT from a practical perspective, which was verified with a case study using two additional GTs. The proposed model is expected to support practitioners in the application of suitable GTs to road projects and reduce carbon emissions, resulting in better decision making during road construction projects.

Aeolian sands as material to construct low-volume roads

CSIR Research Space (South Africa)

Paige-Green, P

2011-07-01

Full Text Available Aeolian sands are widespread in many semi-arid to arid areas of the world and often provide the only economic source of construction materials for low volume roads. Experience in southern Africa over a number of decades has shown that provided...

Estimation of resource savings due to fly ash utilization in road construction

Energy Technology Data Exchange (ETDEWEB)

Kumar, Subodh; Patil, C.B. [Centre for Energy Studies, Indian Institute of Technology, New Delhi 110016 (India)

2006-08-15

A methodology for estimation of natural resource savings due to fly ash utilization in road construction in India is presented. Analytical expressions for the savings of various resources namely soil, stone aggregate, stone chips, sand and cement in the embankment, granular sub-base (GSB), water bound macadam (WBM) and pavement quality concrete (PQC) layers of fly ash based road formation with flexible and rigid pavements of a given geometry have been developed. The quantity of fly ash utilized in these layers of different pavements has also been quantified. In the present study, the maximum amount of resource savings is found in GSB followed by WBM and other layers of pavement. The soil quantity saved increases asymptotically with the rise in the embankment height. The results of financial analysis based on Indian fly ash based road construction cost data indicate that the savings in construction cost decrease with the lead and the investment on this alternative is found to be financially attractive only for a lead less than 60 and 90km for flexible and rigid pavements, respectively. (author)

The potential of bioash for utilization in road construction in eastern Croatia

Science.gov (United States)

Zagvozda, Martina; Dimter, Sanja; Rukavina, Tatjana

2017-12-01

In recent years usage of biomass as energy source has intensified in eastern Croatia. Newly built biomass power plants generate great amounts of bioash that is being disposed at landfills. Due to its favorable properties bioashes could be reused as alternative materials in road construction or road fundation. Therefore, research on application of bioashes in construction industry is being conducted at Faculty of Civil Engineering in Osijek. The main motivation behind this research, in a form of biomass and bioash production in eastern Croatia as well as international research on potential application of this types of bioashes, is show in this paper.

The adoption of innovative asphalt equipment in road construction

NARCIS (Netherlands)

Habets, M.J.M.; Voordijk, Johannes T.; van der Sijde, Peter

2011-01-01

Purpose – The purpose of this paper is to provide insight into the adoption process of innovative asphalt equipment in road construction and how the level of knowledge as characterised by the level of education in the companies affects this process. The emphasis is on equipment used for transporting

The influence of management and construction methods in the repair costs of Spain’s low-volume road network

Directory of Open Access Journals (Sweden)

Eutiquio Gallego

2016-06-01

Full Text Available This paper describes the entire process of the implementation of the Spanish low volume road network, including the design criteria, the construction techniques and the management policies during all the periods. The current situation of low volume roads in Spain was analyzed with respect to the legal framework and their actual condition. In addition, the budget required for the repair of 41 low volume roads throughout Spain was calculated in order to statistically analyze the influence of the pavement materials and the period of construction. The main conclusions were that low volume roads constructed during the 1970´s are currently those in the best state of repair and those requiring the lower repair costs, even lower than those constructed after 1980´s. In addition, low volume roads constructed with higher quality materials and using standardized techniques required five times lower repair costs than those made of lower quality materials.

EVALUATION OF ECOLOGICAL AND ECONOMIC EFFICIENCY OF STEEL-MAKING SLAG IN ROAD CONSTRUCTION

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A. K. Коstenkо

2008-01-01

Full Text Available The paper provides an estimation of ecological and economic efficiency of utilization of the electric steel-melting slag of the Belarussian Steel Works in the road construction. The obtained results  give us a reason to consider that involvement of this type of industrial waste into economic turnover is an economically expedient and ecologically justified measure that will allow road-construction enterprises to reduce the cost of installation and construction works and enlarge their resource potential as well as to help the producer of wastes to release funds for innovation development and solve the problem of waste accumulation in the near future.

A framework of analysis for field experiments with alternative materials in road construction.

Science.gov (United States)

François, D; Jullien, A

2009-01-01

In France, a wide variety of alternative materials is produced or exists in the form of stockpiles built up over time. Such materials are distributed over various regions of the territory depending on local industrial development and urbanisation trends. The use of alternative materials at a national scale implies sharing local knowledge and experience. Building a national database on alternative materials for road construction is useful in gathering and sharing information. An analysis of feedback from onsite experiences (back analysis) is essential to improve knowledge on alternative material use in road construction. Back analysis of field studies has to be conducted in accordance with a single common framework. This could enable drawing comparisons between alternative materials and between road applications. A framework for the identification and classification of data used in back analyses is proposed. Since the road structure is an open system, this framework has been based on a stress-response approach at both the material and structural levels and includes a description of external factors applying during the road service life. The proposal has been shaped from a review of the essential characteristics of road materials and structures, as well as from the state of knowledge specific to alternative material characterisation.

Using remote sensing data to predict road fill areas and areas affected by fill erosion with planned forest road construction: a case study in Kastamonu Regional Forest Directorate (Turkey).

Science.gov (United States)

Aricak, Burak

2015-07-01

Forest roads are essential for transport in managed forests, yet road construction causes environmental disturbance, both in the surface area the road covers and in erosion and downslope deposition of road fill material. The factors affecting the deposition distance of eroded road fill are the slope gradient and the density of plant cover. Thus, it is important to take these factors into consideration during road planning to minimize their disturbance. The aim of this study was to use remote sensing and field surveying to predict the locations that would be affected by downslope deposition of eroding road fill and to compile the data into a geographic information system (GIS) database. The construction of 99,500 m of forest roads is proposed for the Kastamonu Regional Forest Directorate in Turkey. Using GeoEye satellite images and a digital elevation model (DEM) for the region, the location and extent of downslope deposition of road fill were determined for the roads as planned. It was found that if the proposed roads were constructed by excavators, the fill material would cover 910,621 m(2) and the affected surface area would be 1,302,740 m(2). Application of the method used here can minimize the adverse effects of forest roads.

Phytosociological studies on vegetation change caused by road construction in natural park. III

Energy Technology Data Exchange (ETDEWEB)

Kameyama, A

1975-06-01

An attempt has been made to explain how forests have been destroyed by road construction in a natural park in Japan. The author discussed the methods of analyzing the problem, as well as the impact of the construction on various developmental stages in plants. A survey of the plant community was taken and a vegetation map on a scale of 1:3,000 was made. According to the map, vegetation was affected in an area 10-20m from the road, sometimes 50 m, by exhaust fumes from the traffic.

Investigation into the Application of Construction and Demolition Waste in Urban Roads

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Youyun Li

2017-01-01

Full Text Available The recycling and reuse of waste materials is a topic of global concern and great international interest for those interested in sustainable development and protecting the environment. In recent decades, global production of construction and demolition waste (C&D waste has significantly increased and became a worldwide problem. This research proposes to evaluate the feasibility of using aggregate from recycled C&D waste for urban road embankment applications based on the Sanhuan road construction project in eastern Xi’an. An extensive suite of laboratory and field compaction tests were carried out to determine the physical properties and engineering characteristics of the C&D waste. The effect of curing on the strength of the C&D waste was investigated using unconfined compression strength (UCS, California bearing ratio (CBR, and deflection tests. The results show that the C&D waste has the characteristics of high strength and significant stability after simple treatment and further suggest that the use of these materials for paving urban road embankments is feasible. This study is of value for the reasonable and effective promotion of using C&D waste recycled materials in road subgrade applications.

Assessing changes to in-stream turbidity following construction of a forest road in West Virginia

Science.gov (United States)

Jingxin Wang; Pamela J. Edwards; William A. Goff

2011-01-01

Two forested headwater watersheds were monitored to examine changes to in-stream turbidity following the construction of a forest haul road. One watershed was used as an undisturbed reference, while the other had a 0.92-km (0.57-mi) haul road constructed in it. The channels in both are intermittent tributaries of the Left Fork of Clover Run in the Cheat River watershed...

A cost-benefit analysis of tracking and tracing systems in road construction

NARCIS (Netherlands)

Voordijk, Johannes T.; Akintoye, A

2001-01-01

A major problem in road construction is the lack of timely and accurate information about the location and productivity of equipment. As a result, the productivity rate of certain types of construction equipment is low and equipment has to be hired in from third parties. Lack of co-ordination

Dynamic Analysis of an Office Building due to Vibration from Road Construction Activities

Science.gov (United States)

Chik, T. N. T.; Kamil, M. R. H.; Yusoff, N. A.; Ibrahim, M. H. W.

2018-04-01

Construction activities are widely known as one of the predominant sources of man-made vibrations that able to create nuisance towards any adjacent building, and this includes the road construction operations. Few studies conclude the construction-induced vibration may be harmful directly and indirectly towards the neighbouring building. This lead to the awareness of study the building vibration response of concrete masonry load bearing system and its vibrational performance towards the road construction activities. This study will simulate multi-storey office building of Sekolah Menengah Kebangsaan (SMK) Bandar Enstek at Negeri Sembilan by using finite element vibration analyses. The excitation of transient loads from ground borne vibrations which triggered by the road construction activities are modelled into the building. The vibration response was recorded during in-situ ambient vibration test by using Laser Doppler Vibrometer (LDV), which specifically performed on four different locations. The finite element simulation process was developed in the commercial FEA software ABAQUS. Then, the experimental data was processed and evaluated in MATLAB ModalV to assess the vibration criteria of the floor in building. As a result, the vibration level of floor in building is fall under VC-E curve which was under the maximum permissible level for office building (VC-ISO). The vibration level on floor is acceptable within the limit that have been referred.

Experience in statistical quality control for road construction in South Africa

CSIR Research Space (South Africa)

Mitchell, MF

1977-06-01

Full Text Available of statistically oriented acceptance control procedures to a major road construction project is examined and it is concluded that such procedures promise to be of benefit to both the client and the contractor....

Knowledge Construction in a Teachers' Community of Enquiry: A Possible Road Map

Science.gov (United States)

Zellermayer, Michal; Tabak, Edith

2006-01-01

This action research is targeted at academic researchers who facilitate the construction of communities of enquiry in school-university partnerships and are interested in understanding the process of such an enterprise as well as the knowledge constructed within such communities. Our action research study provides a possible road map for such a…

HYDRAULIC UNITS FOR DRIVING SYSTEMS OF RUNNING EQUIPMENT IN ROAD CONSTRUCTION MACHINERY

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A. Ja. Kotlobai

2016-01-01

Full Text Available Operational efficiency of multi-functional road construction machines depends on number of working bodies which are simultaneously performing technological operations. Systems for propulsion pto to the running equipment drive and active working bodies of road construction machines are developing in the way of using three-axis hydraulic drives. When designing a hydraulic system for road construction machinery dividing of power flow from propulsion to the running equipment drive and active working bodies is considered as rather essential problem. Leading companies do not pay attention to the development of flow divider designs, preferring to produce more expensive multi-flow pumps. One of the ways to increase efficiency of multi-functional road construction machinery is an implementation of running equipment hydraulic driving system based on a mono-aggregate pump unit which consists of a pump and a volumetric divider of power fluid flow. A principle of volumetric division and summing-up of power fluid flows, technical realization and methodology for calculation of key parameters of discrete flow distributors has been developed on the basis of discrete hydraulics regulations. The paper presents results of mathematical modeling of hydraulic systems equipped with the discrete flow distributor. Analysis of a dual-motor hydraulic drive operation has shown the following results: a discrete flow distributor ensures independent load mode of the current consumer circuit operation from the load mode of the second consumer circuit within a wide range of loads; rational value of working fluid flow discretization parameter is the following value interval k = 4–6, maximum value of parameter efficiency is reached when an angular velocity of a distributor rotor coincides with the angular velocity of a pump shaft; discrete flow distributor provides a possibility to change parameters of hydraulic flow feeding in consumers’ pressure lines within a wide range

Comparing Environmental Impact Assessment (EIA) in Poland and Denmark for Road Construction in Relation to Wildlife and Nature Protection : Synopsis

DEFF Research Database (Denmark)

Sienkiewicz, J.; Briggs, L; Elmeros, M.

Project : Fauna Passages under Selected Roads in Poland - Education, Monitoring and Construction - Part A.......Project : Fauna Passages under Selected Roads in Poland - Education, Monitoring and Construction - Part A....

Soil retention of hexavalent chromium released from construction and demolition waste in a road-base-application scenario

DEFF Research Database (Denmark)

Butera, Stefania; Trapp, Stefan; Astrup, Thomas Fruergaard

2015-01-01

We investigated the retention of Cr(VI) in three subsoils with low organic matter content in laboratory experiments at concentration levels relevant to represent leachates from construction and demolition waste (C&DW) reused as unbound material in road construction. The retention mechanism appeared...... depth. However, in rigid climates and with high water infiltration through the road pavement, the reduction reaction could be so slow that Cr(VI) might migrate as deep as 200 cm under the road. The reaction parameters and the model can form the basis for systematically assessing under which scenarios Cr...

How is the older road users’ perception of risk constructed?

DEFF Research Database (Denmark)

Siren, Anu Kristiina; Kjær, Marlene Rishøj

2011-01-01

limitations but by perceiving other road users behaving dangerously. While the self-regulation practices adapted by the participants may have been responses to age-related changes, they were constructed as practices based on the driver’s skills, experience and preferences, and presented as responses...... in their driving behaviour, but there is no unequivocal proof for this in the research literature. The present study aims to help to understand the risk perception of this group by studying how older persons construct their perceptions about risk and safety. The study uses material from focus groups conducted...

Selection and ranking of occupational safety indicators based on fuzzy AHP: A case study in road construction companies

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Janackovic, Goran Lj.

2013-11-01

Full Text Available This paper presents the factors, performance, and indicators of occupational safety, as well as a method to select and rank occupational safety indicators based on the expert evaluation method and the fuzzy analytic hierarchy process (fuzzy AHP. A case study is done on road construction companies in Serbia. The key safety performance indicators for the road construction industry are identified and ranked according to the results of a survey that included experts who assessed occupational safety risks in these companies. The case study confirmed that organisational factors have a dominant effect on the quality of the occupational health and safety management system in Serbian road construction companies.

Geochemical anomalies from bottom ash in a road construction--comparison of the leaching potential between an ash road and the surroundings.

Science.gov (United States)

Lind, Bo B; Norrman, Jenny; Larsson, Lennart B; Ohlsson, Sten-Ake; Bristav, Henrik

2008-01-01

A study was performed between June 2001 and December 2004 with the primary objective of assessing long-term leaching from municipal solid waste incineration bottom ash in a test road construction in relation to a reference road made up of conventional materials and the natural geochemical conditions in the surroundings. The metal leaching from the test road and the reference road was compared with the natural weathering in the regional surroundings for three time scales: 16, 80 and 1000 years. The results show that Cu and Zn cause a geochemical anomaly from the test road compared with the surroundings. The leaching of Cu from the test road is initially high but will decline with time and will in the long term be exceeded by natural weathering. Zn on the other hand has low initial leaching, which will increase with time and will in the long term exceed that of the test road and the surroundings by a factor of 100-300. For the other metals studied, Al, Na, K and Mg, there is only very limited leaching over time and the potential accumulation will not exceed the background values in a 1000 years.

Safety impacts of rural road construction

Science.gov (United States)

2001-02-01

Crash data in Kentucky show that the fatal crash rate on two-lane rural roads is substantially higher than on any other type of road. Improvements have been proposed at some locations on this type of road which involve either upgrading the existing t...

Recommendations for Constructing Roadside Vegetation Barriers to Improve Near-Road Air Quality

Science.gov (United States)

The EPA report, Recommendations for Constructing Roadside Vegetation Barriers to Improve Near-Road Air Quality, summarizes the research findings on the best practices for building roadside vegetative barriers to improve air quality. This fact sheet describ

ASSESSMENT CRITERIA OF FUNCTIONALITY GEOTEXTILES USED IN ROAD CONSTRUCTION

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LUCA Cristinel

2016-05-01

Full Text Available This work was performed in order to assess the functionality of geotextiles used in road construction. To increase the quality of road works requires the use of geotextiles in their structure. Depending on the role and the benefits they offer, geotextiles have a number of physical properties, hydraulic, endurance and optimal characteristics regarding their degradation. Geotextile properties were identified and divided according to their characteristics area. Thus, there were obtained textile properties oriented towards geotextiles and properties geared to the application field respectively reinforcement, drainage, and filtration. Value engineering works at the level of constructive product conception and production. The instrumentation is done by functional analysis, value functions and design or redesign of geotextile based on the necessary functions. Systematic research method allowed geotextiles dimensioning functions in order to obtain products in terms of quality, reliability and maximum operational performance. Functions obtained from the analysis are appropriate for a single property. After obtaining the set of decisions was possible functions geotextiles hierarchy after the significance of their use. Establishing the importance of the coefficients or characteristics hierarchy after their weight requires the comparison of the features between them and grading them in proportion to their degree of importance. The ranking of these functions is beneficial when designing or redesigning geotextiles.

Testing the possibility for reusing mswi bottom ash in Greenlandic road construction

DEFF Research Database (Denmark)

Kirkelund, Gunvor Marie; Jørgensen, Anders Stuhr; Villumsen, Arne

2012-01-01

requirements (a grain size distribution, wear resistance, visual fraction analysis and bearing capacity) for reuse as fill material in road construction [2]. Environmental classification based on heavy metal content and leachability was also investigated. The tests showed that it will not be possible to use......, which can influence the quality of MWSI residues. About 15,000 tons MSWI bottom ash is produced annually in Greenland and is disposed of at the open disposal sites without leachate collection or encapsulation. The MSWI bottom ash could have value as a secondary resource in construction work in Greenland...... the bottom ash directly after the incineration as the bottom ash did not comply with all the requirements specified by the Danish Road Directorate. These technical requirements could be improved by removing large fractions (> 45mm) and metal parts as well as changing the grain size distribution...

Efficient Geo-Computational Algorithms for Constructing Space-Time Prisms in Road Networks

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Hui-Ping Chen

2016-11-01

Full Text Available The Space-time prism (STP is a key concept in time geography for analyzing human activity-travel behavior under various Space-time constraints. Most existing time-geographic studies use a straightforward algorithm to construct STPs in road networks by using two one-to-all shortest path searches. However, this straightforward algorithm can introduce considerable computational overhead, given the fact that accessible links in a STP are generally a small portion of the whole network. To address this issue, an efficient geo-computational algorithm, called NTP-A*, is proposed. The proposed NTP-A* algorithm employs the A* and branch-and-bound techniques to discard inaccessible links during two shortest path searches, and thereby improves the STP construction performance. Comprehensive computational experiments are carried out to demonstrate the computational advantage of the proposed algorithm. Several implementation techniques, including the label-correcting technique and the hybrid link-node labeling technique, are discussed and analyzed. Experimental results show that the proposed NTP-A* algorithm can significantly improve STP construction performance in large-scale road networks by a factor of 100, compared with existing algorithms.

An empirical study for ranking risk factors using linear assignment: A case study of road construction

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Amin Foroughi

2012-04-01

Full Text Available Road construction projects are considered as the most important governmental issues since there are normally heavy investments required in such projects. There is also shortage of financial resources in governmental budget, which makes the asset allocation more challenging. One primary step in reducing the cost is to determine different risks associated with execution of such project activities. In this study, we present some important risk factors associated with road construction in two levels for a real-world case study of rail-road industry located between two cities of Esfahan and Deligan. The first group of risk factors includes the probability and the effects for various attributes including cost, time, quality and performance. The second group of risk factors includes socio-economical factors as well as political and managerial aspects. The study finds 21 main risk factors as well as 193 sub risk factors. The factors are ranked using groups decision-making method called linear assignment. The preliminary results indicate that the road construction projects could finish faster with better outcome should we carefully consider risk factors and attempt to reduce their impacts.

Carbon Nanomaterials for Road Construction

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Zaporotskova Irina Vladimirovna

2015-05-01

Full Text Available The requirement of developing and modernizing the roads in Russia and in the Volgograd region in particular, is based on need of expanding the directions of scientific research on road and transport complexes. They have to be aimed at the development of the theory of transport streams, traffic safety increase, and, first of all, at the application of original methods of road development and modernization, introduction of modern technologies and road-building materials.On the basis of the analysis of the plans for transportation sphere development in the Volgograd region assuming the need to apply the new technologies allowing to create qualitative paving, the authors propose the technology of creating a heavy-duty paving with the use of carbon nanomaterial. The knowledge on strengthening the characteristics of carbon nanotubes is a unique material for nanotechnology development which allowed to assume the analysis of general information about asphalt concrete. The analysis showed that carbon nanotubes can be used for improvement of operational characteristics of asphalt concrete, and it is possible to carry out additives of nanotubes in hot as well as in cold bitumen. The article contains the basic principles of creation of the new road material received by means of bitumen reinforcing by carbon nanotubes. The structures received by the offered technique binding on the basis of the bitumens modified by carbon nanomaterial can be used for coverings and bases on highways of all categories in all road and climatic zones of Russia. The technical result consists in increasing the durability and elasticity of the received asphalt covering, and also the increase of water resistance, heat resistance and frost resistance, the expansion of temperature range of its laying in the field of negative temperatures.

Planning of road construction projects with a view to stimulating economic growth and development

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Wessel Pienaar

2014-08-01

Full Text Available This paper provides an outline of how the economic evaluation and selection of road construction projects can be complemented by social evaluation with a view to achieving a more equitable welfare distribution within a developing country. The article commences by elaborating on the general economic benefits that can arise from investment in economically justified road infrastructure. The different classes of non-road-user beneficiaries are idenified and discussed. The operational characteristics of road transport that are conducive to the stimulation of economic activity are identified and described. The present inequality of income distribution in South Africa is dealt with briefly, followed by a discussion and analysis on the use of equity weights in project evaluation to help bring about a more equitable welfare distribution.

Characterisation of MSWI bottom ash for potential use as subbase in Greenlandic road construction

DEFF Research Database (Denmark)

Kirkelund, Gunvor Marie; Jørgensen, Anders Stuhr; Ingeman-Nielsen, Thomas

2012-01-01

of infrastructure due to increased oil and mineral exploitation. Thus, in this study MSWI bottom ash from a Greenlandic incinerator was tested for possible reuse as subbase in road construction. The mechanical properties (grain size distribution, wear resistance and bearing capacity) showed that the bottom ash...... grain sizes and could be reduced by removing some of these smaller grain sizes to obtain the stability requirement of the bottom ash. All in all, this study showed that the Greenlandic bottom ash has potential for being reused in road construction....... was acceptable for reuse after some small adjustments in the grain size distribution to prevent frost sensitivity. Results obtained from heavy metal content and heavy metal leaching complied with the Danish guideline values for reuse of waste materials in construction. Leaching of Cu and Cr was high from small...

Improving Role of Construction Industry for More Effective Post-Disaster Emergency Response To Road Infrastructure in Indonesia

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Pribadi Krishna S.

2018-01-01

Full Text Available Geo- and hydro-meteorological disasters typically caused disruptive impact to road networks due to damaged road infrastructure, which in turn disconnect access to and isolate the disaster affected areas. Road clearing work and emergency road recovery operation are considered a priority to reconnect the access during post-disaster emergency response. However, the operation is not always smooth and in many cases delayed due to various problems. An investigation is conducted to understand the current practice of post-disaster emergency road recovery operation in Indonesia and to study possible participation of construction industry in order to improve its effectiveness. In-depth interviews with Local Disaster Management Agencies (BPBDs and local road agencies in West Java Province were conducted to understand current practices in emergency road recovery operation and to view perspectives on local contractor participation. The surveys showed supports from the local governments for contractor involvement as long as it is still under guidance of related agencies (Ministry of Public Works and Housing despite some possible obstacles from the current regulation that may hamper contractors’ participation, which indicate that there is a potential role of construction industry for more effective post-disaster emergency response, provided that contractor associations are involved and existing procurement regulation is improved.

Recent trends of the emission characteristics from the road construction industry.

Science.gov (United States)

Chauhan, Sippy K; Sharma, Sangita; Shukla, Anuradha; Gangopadhyay, S

2010-11-01

Bitumen is a black, thermoplastic, hydrocarbon material derived from the processing of crude oil. At ambient temperature, bitumen is solid and does not present any health/environmental risks. This is one of the main reasons that bitumen is widely used for road construction all over the world. But during manufacturing/modification according to its application, storage, transportation, and use of bitumen is heated giving off various hydrocarbons emissions. In recent years, there has been increasing interest in investigating the potential of bitumen emissions to cause health effects. This is mainly because of the reason that bitumen has small amount of poly-aromatic hydrocarbons, along with some other volatiles like benzene, toluene, etc., which are known to be carcinogenic in nature. Thus, assessment of the emission characteristics and health hazards of bitumen fumes may have far reaching industrial economic and public health implications. In this review, we will discuss about the emission characteristics from bitumen, asphalts, or road construction, which is mainly contributed by bitumen fumes. Sampling strategies and analytical methods employed are also described briefly.

Carbon footprint comparison of innovative techniques in the construction and maintenance of road infrastructure in The Netherlands

NARCIS (Netherlands)

Keijzer, E.E.; Leegwater, G.A.; Vos-Effting, S.E. de; Wit, M.S. de

2015-01-01

The ambition of European countries to reduce their national greenhouse gas emissions, has been translated in the Netherlands in green procurement policy of the national road administration. An increasing amount of innovative techniques and approaches in road infrastructure construction and

Characterisation of Beaver Habitat Parameters That Promote the Use of Culverts as Dam Construction Sites: Can We Limit the Damage to Forest Roads?

Directory of Open Access Journals (Sweden)

Geneviève Tremblay

2017-12-01

Full Text Available The use of forest roads as foundations for dam construction by beavers is a recurrent problem in the management of forest road networks. In order to limit the damage to forest roads, our goal was to calculate the probability of beaver dam installation on culverts, according to surrounding habitat parameters, which could allow for improvement in the spatial design of new roads that minimise conflicts with beavers. Comparisons of culverts with (n = 77 and without (n = 51 dams in northwestern Quebec showed that catchment surface, cumulate length of all local streams within a 2-km radius, and road embankment height had a negative effect on the probability of dam construction on culverts, while flow level and culvert diameter ratio had a positive effect. Nevertheless, predicted probabilities of dam construction on culverts generally exceeded 50%, even on sites that were less favourable to beavers. We suggest that it would be more reasonable to take their probable subsequent presence into account at the earliest steps of road conception. Installing mitigation measures such as pre-dams during road construction would probably reduce the occurrence of conflicts with beavers and thus reduce the maintenance costs of forest roads.

Trajectory of a road vehicle during road maintenance

OpenAIRE

Stachová Darina

2017-01-01

Consider a vehicle moving on a road whose usage over time creates an uneven surface on the road. Road unevenness that we encounter on surface communications often arises as a consequence of dynamical effects of moving vehicles, of weather changes, and due to road construction works. This article concerns with mathematical modeling of the trajectory of a road vehicle moving on such a surface during the course of road maintenance.

Application of liquid-based cytology preparation in micronucleus assay of exfoliated buccal epithelial cells in road construction workers.

Science.gov (United States)

Arul, P

2017-01-01

Asphalts are bitumens that consist of complex of hydrocarbon mixtures and it is used mainly in road construction and maintenance. This study was undertaken to evaluate the micronucleus (MN) assay of exfoliated buccal epithelial cells in road construction workers using liquid-based cytology (LBC) preparation. Three different stains (May-Grunwald Giemsa, hematoxylin and eosin, and Papanicolaou) were used to evaluate the frequency of MN in exfoliated buccal epithelial of 100 participants (fifty road construction workers and fifty administrative staff) using LBC preparation. Statistical analysis was performed with Student's t-test, and Proad construction exhibit a higher frequency of MN in exfoliated buccal epithelial cells and they are under the significant risk of cytogenetic damage. LBC preparation has potential application for the evaluation of frequency of MN. This technique may be advocated in those who are occupationally exposed to potentially carcinogenic agents in view of improvement in the smear quality and visualization of cell morphology.

Assessment of the underground construction details of a road pavement using GPR antenna systems with different frequencies

Science.gov (United States)

Alani, Amir M.; Tosti, Fabio; Bianchini Ciampoli, Luca; Benedetto, Francesco; Benedetto, Andrea

2017-04-01

The assessment of the underground construction details of a road infrastructure is a problem of great concern in highway engineering. The case becomes complicated especially when damages reoccur after carrying out remedial surface maintenance and repair works over the life cycle of the infrastructure. The challenge will be exacerbated at the presence of underground watercourses, such that the geotechnical stability of the entire road structure could be threatened. In this respect, ground-penetrating radar (GPR) has been recognised and accepted as one of the most effective non-destructive testing (NDT) techniques that could be employed in identifying the cause/s of such problems. The recent advancements and developments made in the field of GPR hardware as well as the current level of understanding of the applications and processing techniques of the GPR data have immensely added to the reliability in the utilisation of this tool in variety of subsurface investigation projects. In view of this, the work presented in here focuses on the assessment of the underground construction details of a road pavement using different frequency GPR antenna systems. In addition to this, the possible presence and location of an underground watercourse was investigated in this work. The existence of the latter problem was perceived due to reoccurrence of longitudinal and traversal road surface cracking as well as subsidence at a particular location of the road. Reoccurrence of this damage was interpreted and related to the possible existence of an underground watercourse. The original design and the construction of the road were as such to prevent this movement. Therefore it seemed necessary to perform a GPR survey to investigate and confirm the underground construction details of the road. To this purpose, the identified area was surveyed using high to low frequency antennas with 2000 MHz, 900 MHz, 600 MHz and 200 MHz central frequencies of investigation. Scans were performed at 1m

Road user behaviour changes following a self-explaining roads intervention.

Science.gov (United States)

Mackie, Hamish W; Charlton, Samuel G; Baas, Peter H; Villasenor, Pablo C

2013-01-01

The self-explaining roads (SER) approach uses road designs that evoke correct expectations and driving behaviours from road users to create a safe and user-friendly road network. Following the implementation of an SER process and retrofitting of local and collector roads in a suburb within Auckland City, lower speeds on local roads and less variation in speed on both local and collector roads were achieved, along with a closer match between actual and perceived safe speeds. Preliminary analyses of crash data shows that the project has resulted in a 30% reduction crash numbers and an 86% reduction in crash costs per annum, since the road changes were completed. In order to further understand the outcomes from this project, a study was carried out to measure the effects of the SER intervention on the activity and behaviour of all road users. Video was collected over nine separate days, at nine different locations, both before and after SER construction. Road user behaviour categories were developed for all potential road users at different location types and then used to code the video data. Following SER construction, on local roads there was a relatively higher proportion of pedestrians, less uniformity in vehicle lane keeping and less indicating by motorists along with less through traffic, reflecting a more informal/low speed local road environment. Pedestrians were less constrained on local roads following SER construction, possibly reflecting a perceptually safer and more user-friendly environment. These behaviours were not generally evident on collector roads, a trend also shown by the previous study of speed changes. Given that one of the objectives of SER is to match road user behaviour with functionally different road categories, the road user behaviour differences demonstrated on different road types within the SER trial area provides further reinforcement of a successful SER trial. Copyright © 2012 Elsevier Ltd. All rights reserved.

Impacts of disturbance initiated by road construction in a subtropical cloud forest in the Luquillo Experimental Forest, Puerto Rico

Science.gov (United States)

Lydia P. Olander; F.N Scatena; Whendee L. Silver

1998-01-01

The impacts of road construction and the spread of exotic vegetation, which are common threats to upper elevation tropical forests, were evaluated in the subtropical cloud forests of Puerto Rico. The vegetation, soil and microclimate of 6-month-old road®lls, 35-year-old road®lls and mature forest with and without grass understories were compared. Recent road®lls had...

Complex solution of problem of all-season construction of roads and pipelines on universal composite pontoon units

Science.gov (United States)

Ryabkov, A. V.; Stafeeva, N. A.; Ivanov, V. A.; Zakuraev, A. F.

2018-05-01

A complex construction consisting of a universal floating pontoon road for laying pipelines in automatic mode on its body all year round and in any weather for Siberia and the Far North has been designed. A new method is proposed for the construction of pipelines on pontoon modules, which are made of composite materials. Pontoons made of composite materials for bedding pipelines with track-forming guides for automated wheeled transport, pipelayer, are designed. The proposed system eliminates the construction of a road along the route, ensures the buoyancy and smoothness of the self-propelled automated stacker in the form of a "centipede", which has a number of significant advantages in the construction and operation of the entire complex in the swamp and watered areas without overburden.

Environmental impact assessment of wood ash utilization in forest road construction and maintenance--A field study.

Science.gov (United States)

Oburger, Eva; Jäger, Anna; Pasch, Alexander; Dellantonio, Alex; Stampfer, Karl; Wenzel, Walter W

2016-02-15

The ever increasing use of wood material as fuel for green energy production requires innovative, environmentally safe strategies for recycling of the remaining wood ash. Utilizing wood ash in forest road construction and maintenance to improve mechanical stability has been suggested as a feasible recycling option. To investigate the environmental impact of wood ash application in forest road maintenance, a two-year field experiment was conducted at two Austrian forest sites (Kobernausserwald (KO) (soil pH 5.5) and Weyregg (WE) (pH 7.7)) differing in their soil chemical properties. Two different ashes, one produced by grate incineration (GA) and the other by fluidized bed incineration in a mixture with 15 vol% burnt lime (FBA), were incorporated in repeated road sections at a 15:85% (V/V) ash-to-soil rate. Leaching waters from the road body were collected and analyzed for 32 environmentally relevant parameters over two years. Upon termination of the experiment, sub-road soil samples were collected and analyzed for ash-related changes in soil chemistry. Even though a larger number of parameters was affected by the ash application at the alkaline site (WE), we observed the most pronounced initial increases of pH as well as Al, As, Fe, Mn, Ni, Co, Cu, Mo, and NO2(−) concentrations in leachates beneath GA-treated road bodies at Kobernausserwald due to the lower soil buffer capacity at this site. Despite the observed effects our results indicate that, when specific requirements are met (i.e. appropriate ash quality, sufficient soil buffer capacity below the road body, and single time-point ash incorporation within several decades), wood ash application in forest road construction is generally environmentally acceptable.

Some effects of logging and associated road construction on northern California streams

Science.gov (United States)

James W. Burns

1972-01-01

Abstract - The effects of logging and associated road construction on four California trout and salmon streams were investigated from 1966 through 1969. This study included measurements of streambed sedimentation, water quality, fish food abundance, and stream nursery capacity. Logging was found to be compatible with anadromous fish production when adequate attention...

Developing design methods of concrete mix with microsilica additives for road construction

Science.gov (United States)

Dmitrienko, Vladimir; Shrivel, Igor; Kokunko, Irina; Pashkova, Olga

2017-10-01

Based on the laboratory test results, regression equations having standard cone and concrete strength, to determine the available amount of cement, water and microsilica were obtained. The joint solution of these equations allowed the researchers to develop the algorithm of designing heavy concrete compositions with microsilica additives for road construction.

Cost of and soil loss on "minimum-standard" forest truck roads constructed in the central Appalachians

Science.gov (United States)

J. N. Kochenderfer; G. W. Wendel; H. Clay Smith

1984-01-01

A "minimum-standard" forest truck road that provides efficient and environmentally acceptable access for several forest activities is described. Cost data are presented for eight of these roads constructed in the central Appalachians. The average cost per mile excluding gravel was $8,119. The range was $5,048 to $14,424. Soil loss was measured from several...

Construction of Three-Dimensional Road Surface and Application on Interaction between Vehicle and Road

Directory of Open Access Journals (Sweden)

Lu Yongjie

2018-01-01

Full Text Available The quantitative description is given to three-dimensional micro and macro self-similar characteristics of road surface from the perspective of fractal geometry using FBM stochastic midpoint displacement and diamond-square algorithm in conjunction with fractal characteristics and statistical characteristics of standard pavement determined by estimation method of box-counting dimension. The comparative analysis between reconstructed three-dimensional road surface spectrum and theoretical road surface spectrum and correlation coefficient demonstrate the high reconstruction accuracy of fractal reconstructed road spectrum. Furthermore, the bump zone is taken as an example to reconstruct a more arbitrary 3D road model through isomorphism of special road surface with stochastic road surface model. Measurement is taken to assume the tire footprint on road surface to be a rectangle, where the pressure distribution is expressed with mean stiffness, while the contact points in the contact area are replaced with a number of springs. Two-DOF vehicle is used as an example to analyze the difference between three-dimensional multipoint-and-plane contact and traditional point contact model. Three-dimensional road surface spectrum provides a more accurate description of the impact effect of tire on road surface, thereby laying a theoretical basis for studies on the dynamical process of interaction of vehicle-road surface and the road friendliness.

Comparing Environmental Impact Assessment (EIA) in Poland and Denmark for Road Construction in Relation to Wildlife and Nature Protection : Report for Poland

DEFF Research Database (Denmark)

Sienkiewicz, J.; Adrados, L. C.; Briggs, L

Project : Fauna Passages under Selected Roads in Poland - Education, Monitoring and Construction - Part A. DANCEE M124/031-0212......Project : Fauna Passages under Selected Roads in Poland - Education, Monitoring and Construction - Part A. DANCEE M124/031-0212...

[Purveyors of technology: provincial engineers and the construction of road infrastructure in Minas Gerais].

Science.gov (United States)

Barbosa, Lidiany Silva

2011-01-01

The article analyzes the role played by engineers in the construction of road infrastructure in Minas Gerais between the 1840s and 1880s. Building and providing regular maintenance for roads and bridges was a task carried out by the Minas Gerais provincial government, which since the 1830s had a specific agency assigned to designing, building, and maintaining public communication routes. Engineers were part of the agency from its inception, playing a significant role in designing projects and in the actual execution of certain works. The current study is grounded in administrative documentation in which the details of work progress are reported to the provincial government. The gathered records provide technical, administrative, and financial information, along with data on labor power and the agents engaged in construction works.

How does grazing relate to body mass index, self-compassion, mindfulness and mindful eating in a student population?

Science.gov (United States)

Mantzios, Michail; Egan, Helen; Bahia, Henna; Hussain, Misba; Keyte, Rebecca

2018-01-01

Contemporary research investigating obesity has focused on grazing (i.e. an uncontrolled and repetitive consumption of small amounts of food). Meanwhile, constructs such as mindfulness, mindful eating and self-compassion have received much attention in assisting individuals with eating behaviours and weight regulation. The association between those constructs and grazing, however, has not been explored. In a cross-sectional study, university students ( n  = 261) were recruited to explore the relationship of mindfulness, mindful eating and self-compassion with current weight and grazing. Results indicated that all constructs were negatively related to grazing, but only mindful eating related negatively to current weight. In addition, mindful eating mediated the relationship between grazing and current weight. Possible explanations and future directions are discussed further with an emphasis on the need for more empirical work.

Impact of a Newly Constructed Motor Vehicle Road on Altitude Illness in the Nepal Himalayas.

Science.gov (United States)

Reisman, Jonathan; Deonarain, Dinesh; Basnyat, Buddha

2017-12-01

This study investigated the impact that motor vehicle travel along a newly constructed road has on altitude illness (including acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema). The new road from Besisahar (760 m) to Manang (3540 m) in Nepal was completed in December 2014. We enrolled all patients diagnosed with altitude illness at the Himalayan Rescue Association Manang clinic in fall 2016. Phi coefficients were calculated to test for an association between Nepali ethnicity and rapid ascent by motor vehicle. A retrospective review looked at all patients with altitude illness from fall (September-November) 2010 to spring (February-May) 2016. In fall 2016, more than half (54%) of patients with altitude illness traveled to Manang by motor vehicle, and one-third (33%) reached Manang from low altitude (Besisahar) in less than 48 hours. Nepali nationality had a significant association with motor vehicle travel (phi +0.69, P road (P constructed road from Besisahar to Manang appears to be related to a significant increase in the number of patients with all forms of altitude illness, especially among Nepalis. The authors believe that educational interventions emphasizing prevention are urgently needed. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Radiation load of the electro-thermal production of phosphorus. Part 2. The inhalation dose in road construction

International Nuclear Information System (INIS)

Erkens, W.H.H.; Hermans, P.M.J.A.; Timmermans, C.W.M.

2003-01-01

The phosphate ore which is processed by Thermphos International in Vlissingen, Netherlands, to produce element phosphorus contains circa 1 Bq per gram uranium 238. As a result of this production process radionuclides are emitted and slags that contain natural radioisotopes are formed. The slags can be used as a building material for roads and water works. During the production of phosphorus the waste material calcinate is formed as well. Operators, working in the production process of phosphorus and laborers, working in road construction and hydraulic engineering inhale radioisotopes. In two articles attention will be paid to the inhalation doses, how the doses are measured, measures that were taken to reduce and control the doses, and the ALARA-principles. This article is focused on the inhalation doses for road construction workers [nl

[Effects of road construction on regional vegetation types].

Science.gov (United States)

Liu, Shi-Liang; Liu, Qi; Wang, Cong; Yang, Jue-Jie; Deng, Li

2013-05-01

As a regional artificial disturbance component, road exerts great effects on vegetation types, and plays a substantial role in defining vegetation distribution to a certain extent. Aiming at the tropical rainforest degradation and artificial forest expansion in Yunnan Province of Southwest China, this paper analyzed the effects of road network extension on regional vegetation types. In the Province, different classes of roads had different effects on the vegetation types, but no obvious regularity was observed in the effects on the patch areas of different vegetation types due to the great variations of road length and affected distance. However, the vegetation patch number was more affected by lower class roads because of their wide distribution. As for different vegetation types, the vegetations on cultivated land were most affected by roads, followed by Castanopsis hystrix and Schima wallichii forests. Road network formation contributed most to the vegetation fragmentation, and there existed significant correlations between the human disturbance factors including village- and road distributions.

Assessment of the PCDD/F fate from MSWI residue used in road construction in France.

Science.gov (United States)

Badreddine, R; François, D

2009-01-01

MSWI fly ash is susceptible to contain high amount of polychlorinated dibenzo-dioxins and polychlorinated dibenzo-furans. However, the use of MSWI residue for road construction started in France at a period when MSWI Bottom Ash and MSWI fly ash were not separated. From four old road sites, MSWI residue, road soils, reference soils and geo-textiles were sampled and their PCDD/F contents were analyzed. MSWI residue show a great heterogeneity but also high amounts of PCDD/F (14-2960 ng I-TEQ kg(-1)dm). Soils underlying the road show less heterogeneity and PCDD/F contents between 0.57 and 7.23 ng I-TEQ kg(-1)dm, lower than ordinary soils. Moreover, the specific analysis of the 17 toxic PCDD/F congeners (notably the 2,3,7,8-TetraCDD) indicates the very low harmfulness of road soils. The study also allows to assert the relation between the MSWI residue particle size and the PCDD/F content.

Economic comparisons of haul road construction versus forwarding versus longer skid distances

Science.gov (United States)

Michael D. Erickson; Curt C. Hassler; Chris B. LeDoux

1992-01-01

There currently exists no set of basic guidelines for Appalachian loggers to use in the decision making process for selecting the best way to harvest a tract of timber. Specifically, guidelines are needed for deciding between the alternatives of constructing truck haul roads to access an area or other alternatives such as skidding or forwarding timber longer distances...

Engineering geological and geophysical investigations for road construction in the municipality of Sisimiut, West Greenland

DEFF Research Database (Denmark)

Ingeman-Nielsen, Thomas; Clausen, Helle; Foged, Niels Nielsen

2007-01-01

In connection with a road construction project between the towns of Sisimiut and Kangerlussuaq in Central West Greenland, the Arctic Technology Centre has been involved in prospecting and site investigations. This paper presents a selection of results concerning the climatic conditions...... and construction work in order to counter the effects of permafrost degradation and increased active layer thickness....

Hydrologic Impact of Harvesting and Road Construction in Mountainous Regime of Pacific Northwest

Science.gov (United States)

Du, E.; Hubbart, J.; Gravelle, J.; Link, T.

2006-12-01

The impact of forest management practices on hydrologic flow regimes have been debated for years. Vegetation removal and forest road construction are two anthropogenic disturbances that may affect watershed hydrology. The Mica Creek Experimental Watershed (MCEW), ID was initiated by Potlatch Corporation in 1990 to evaluate how contemporary forest harvest practices may impact water flows, quality and aquatic health. The study was recently expanded to identify the specific mechanisms producing the observed flow responses. The extensive and long term monitoring program in MCEW enables the validation of simulated internal watershed processes, thereby increasing our confidence in the ability of models to simulate the hydrologic effects of land cover change. The spatially-distributed, physically-based Distributed Hydrology Soil Vegetation Model (DHSVM), will be used to deconvolve the effects of canopy change, forest road construction, and climate variability in MCEW. First, the model performance will be assessed for pre-harvest, post-road, and post-harvest experimental periods. The model will then be used to explore how the flow regime would be expected to differ under historical, alternative management and future scenarios. A retrospective study of fully-harvested and increased forest road density (as opposed to current road density of 3 to 5 percent by surface area) will be compared with contemporary management practices. The impact of harvest patterns on sub-catchment flows will be assessed to understand the degree to which flow synchronization or desynchronization on confluent streams might affect cumulative downstream flow regime. Future scenarios will assess the potential impact of climatic variability that is expected to raise the transient snow zone and increase the wintertime rain to snow ratios in the Pacific Northwest. Variables such as harvest patterns and climate variation will be manipulated to project whether the hydrologic effects of land cover and

Development of econometric models for cost and time over-runs: an empirical study of major road construction projects in pakistan

International Nuclear Information System (INIS)

Khan, A.; Chaudhary, M.A.

2016-01-01

The construction industry is flourishing worldwide and contributes about 10% to the GDP of the world i.e. up to the tune of 4.6 Trillion US dollars. It employs almost 7% of the total employee dpersons and, consumes around 40% of the total energy. The Pakistani construction sector has displayed impressive growth in recent past years. The efficient road network is a key part of construction business and plays a significant role in the economic uplift of country. The overruns in costs and delays in completion of projects are very common phenomena and it has also been observed that the projects involving construction of roads also face problems of delays and cost over runs especially in developing countries. The causes of cost overruns and delays in road projects being undertaken by the premier road construction organization of Pakistan National Highway Authority (NHA) have been considered in this study. It has been done specifically in the context of impact of cause(s) determined from project report of a total of one hundred and thirty one (131) projects. The ten causative factors which we recognize as Design, Planning and Scheduling Related problems, Financial Constraint Related reasons, Social Problem Related reasons, Technical Reasons, Administrative Reasons, Scope Increase, Specification Changes, Cost Escalation Related reasons, Non-Availability of Equipment or Material and Force Majeure play a commanding role in determination of the cost and time over runs. It has also been observed that among these identified causes, the factors of Administrative Reason, Design, Planning and Scheduling Related, Technical Reasons and Force Majeure are the most significant reasons in cost and time overruns. Whereas, the Cost Escalation related reasons has the least impact on cost increase and delays. The NHA possesses a financial worth of around Rs. 36 billion and with an annual turn over amounting to Rs. 22 billion is responsible to perform road construction project in entire

Identifying unstable sites on logging roads

Science.gov (United States)

R. M. Rice; J. Lewis

1986-01-01

Logging roads are an important source of forestry-related erosion. The amount of erosion on a forest road is determined by the interaction between how the road is constructed and maintained and the environment in which it is built. The roads in this study were constructed with large bulldozers, and most excavated material was sidecast. The roads studied were...

Grazing behavior and intake of goats rotationally grazing Tanzania-grass pasture with different post-grazing residues

Directory of Open Access Journals (Sweden)

Marcia H.M.R. Fernandes

2016-05-01

Full Text Available This study aimed to evaluate intake and ingestive behavior of goats rotationally grazing Tanzania (Panicum maximum cv. Tanzânia 1 pastures with 2 levels of post-grazing residue. The experimental area consisted of 1.2 ha of Tanzania pasture divided into 12 paddocks (24 areas, managed under 2 post-grazing residues: low green (leaf + stem herbage mass (GHM post-grazing (LR, approximately 1,500 kg/ha GHM; and high GHM post-grazing (HR, approximately 3,000 kg/ha GHM. Each paddock was grazed for 3 consecutive days (D1, D2, D3 followed by 33 days rest and evaluated from October 2005 to April 2006. Animal behavior (grazing time, bite rate and bite size/weight was evaluated on each grazing day. While goats spent more time grazing on LR than HR (P=0.02, bite rate did not differ between treatments or among days (P=0.31 and averaged 26.5 bites/min. In contrast, bite weight was greater in HR (0.15 g/bite than in LR (0.12 g/bite, and decreased from D1 to D3 (P<0.001. Absolute dry matter intake of goats was greater in the HR (2.19 kg/d than the LR (1.89 kg/d treatment; however, differences were not significant (P>0.05 when intake was determined on a body weight or metabolic weight basis. Our findings are consistent with the general assumption that bite weight is a trade-off between quantity and quality of the herbage mass and is the main determinant of animal performance. More studies are needed to determine animal performance on the various treatments and to determine management strategies to provide a desirable balance between animal weight gain and pasture stability.Keywords: Animal behavior, foraging, grazing systems, Megathyrsus maximus, plant - animal relations.DOI: 10.17138/TGFT(491-100

ANALYSIS AND ASSESSMENT OF RISKS ASSOCIATED WITH CONSTRUCTION OF THE ROAD INFRASTRUCTURE IN SLOVAKIA

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Dávid Šimko

2014-06-01

Full Text Available The article analyzes the risks associated with the process of constructing the road infrastructure. It´s showing us how many different types of risks threats this process and what can happen if we ignore them. In the article are these risks divided in different groups according to the place in this process where they arise, they are also singly defined and described. In the end of the article is possible to find different proposals for the elimination of these risks and also there are mentioned a few reasons why is building of the road infrastructure in Slovakia so slow.

Soil density and moisture content on two unused forest roads during first 30 months after construction

Science.gov (United States)

J.D. Helvey; J.N. Kochenderfer; J.N. Kochenderfer

1990-01-01

Reports results of soil density and soil moisture measurements on two roads in the central Appalachians over a 30-month period. Density increased slightly during the measurement period at most locations. Almost all of the density changes occurred during the first few months after construction. Moisture content decreased during the first few months after construction,...

Behavior of crushed rock aggregates used in road construction exposed to cold climate conditions

Science.gov (United States)

Kuznetsova, Elena; Pérez Fortes, Ana Patricia; Anastasio, Sara; Willy Danielsen, Svein

2016-04-01

Presently, about 90% of the aggregate production in Europe comes from naturally occurring resources: quarries and pits. Due to the increased demand for sand and gravel for construction purposes, not only in building but also in road construction, the last decade has seen a significant trend towards the use of more crushed rock aggregates. This resource has been more and more preferred to sand and gravel thanks to the significant technological development of its process and use phase. The performance of the aggregates is generally evaluated depending on three main factors: the geological origin (mineral composition, texture, structure, degree of weathering), the aggregate processing (crushing, sieving, washing, storing) and the user technology for a specific area of use (e.g. road construction, asphalt binders). Nevertheless climatic conditions should carefully be taken into account in application such as road construction. Large temperature gradients and high levels of humidity are known to significantly affect the performance of the material. Although the problem is, at least in the asphalt field, considered mostly from the binder point of view, this article aims to investigate the effect of aggregate properties on road performance in cold climatic conditions. Two different climatic areas will be taken into account: Norway and Spain. While both these countries are listed among the main European producers of aggregates, they represent significantly different climatic regions. While Norwegian weather is characterized by humid cold winters and relatively mild summers, Spain has temperate climate with cold regions in mountainous and internal areas. Both countries have been significantly affected by climate change with increasing temperature variations and instability. At the same time, similar winter maintenance measures, including the use of a considerable amount of solid and liquid chemicals to avoid ice formation (e.g. NaCl) and/or to provide better friction, are

Quantification of the effects of environmental leaching factors on emissions from bottom ash in road construction.

Science.gov (United States)

Ecke, Holger; Aberg, Annika

2006-06-01

The re-use of bottom ash in road construction necessitates a tool to predict the impact of trace metals on the surroundings over the lifetime of the road. The aim of this work was to quantify the effect of environmental factors that are supposed to influence leaching, so as to suggest guidelines in developing a leaching procedure for the testing of incineration residues re-used in road constructions. The effects of pH, L/S (liquid-to-solid ratio), leaching time, and leaching atmosphere on the leachate concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were studied using a two-level full factorial design. The most significant factor for all responses was the pH, followed by L/S, though the importance of pH and L/S is often ignored in leaching tests. Multiple linear regression models describing the variation in leaching data had R(2) values ranging from 61-97%. A two-step pH-stat leaching procedure that considers pH as well as L/S and leaching time was suggested.

Marine dredged sediments as new materials resource for road construction.

Science.gov (United States)

Siham, Kamali; Fabrice, Bernard; Edine, Abriak Nor; Patrick, Degrugilliers

2008-01-01

Large volumes of sediments are dredged each year in Europe in order to maintain harbour activities. With the new European Union directives, harbour managers are encouraged to find environmentally sound solutions for these materials. This paper investigates the potential uses of Dunkirk marine dredged sediment as a new material resource for road building. The mineralogical composition of sediments is evaluated using X-ray diffraction and microscopy analysis. Since sediments contain a high amount of water, a dewatering treatment has been used. Different suitable mixtures, checking specific geotechnical criteria as required in French standards, are identified. The mixtures are then optimized for an economical reuse. The mechanical tests conducted on these mixtures are compaction, bearing capacity, compression and tensile tests. The experimental results show the feasibility of the beneficial use of Dunkirk marine dredged sand and sediments as a new material for the construction of foundation and base layers for roads. Further research is now needed to prove the resistance of this new material to various environmental impacts (e.g., frost damage).

Analysis on the Long Term Effect of Trial Test Road Constructed on Batu Pahat Soft Clay (BPSC) at Recess UTHM

Science.gov (United States)

Idrus, M. M. M.; Edayu, A. E.; Adnan, Z.; Ismail, B.

2016-07-01

The reinforcement used in soil for construction of roads on the soft clay is very important as it will determine the level of service of the road after it was built. Damage or defects on the road surface to be an indicator of the level of the road has dropped and shows the deformation of the road. For this research, an analysis has carried out on the long-term effect of trial test road constructed on Batu Pahat Soft Clay (BPSC) at RECESS UTHM. Through this research, the reinforcement using Rawell Geosynthetic Clay Liner (RGCL) was the best with the stability is 14964 N, a low flow is 2.69mm, stiffness modulus is 1766 MPa, the peak load is 739.4 N and a lower horizontal deformation which is 1.71 µm compared Woven Geotextile section and section without geotextile [1] [9]. In terms of deformation can be seen clearly from physical observations that section without geotextile suffered significant damage than others. Settlement of road can also be analyzed by a longitudinal section that plotted based on the result of leveling work. After that, settlements are more visible way on the right side of the road trial. Through lab tests conducted, it indicate that the coring samples obtained from sites of each section meets the specifications set by the Jabatan Kerja Raya (JKR) in terms of stability, flow and stiffness [1]. Through this study, a trial road built on soft soil can be used as a test site because of the uniqueness of these roads which has three different types of reinforcements.

GUIDELINES FOR THE CONSTRUCTION OF THE IT ROAD SAFETY MANAGEMENT SYSTEM

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Jacek CHMIELEWSKI

2016-07-01

Full Text Available The article presents the role, need and idea of implementing an IT system to manage road safety, which is a proposal of the practical implementation of the Gambit programme elements prepared for the Kujawsko-Pomorskie Voivodeship. The usefulness of constructing the system has been presented, together with its users, the proposed content and possibility of its funding. The whole article has been summarised by outlining the opportunities and threats that may occur in the course of system implementation.

AN INVESTIGATION ON THE FOREST ROAD PLANNING AND ROAD GROUND

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Hafız Hulusi ACAR

2001-01-01

Full Text Available It is required that the capital used for construction of road must be technical, economical and used in its location. For this reason, the projects must be prepared for forest roads and all operations belong to roads must be guided according to these projects. In this investigation, available forest road network plan and constructed forest roads were investigated at the point of view technical and forest transportation. After this, it were studied to reach the highest exploitation rate as can as possible. Available forest road density were found as 11.9 m/ha in forest areas for Yesiltepe District. In this condition, exploitation rate was 78 %. After that, optimum forest road network were planned and road density were reached to 22 m/ha and exploitation rate to 86 %. Directed sample method were used from taking soil sample methods and samples were took in mixed system. According to results of the experiments, available forest roads were found in a good degree at the point of view endurance, pressing and transportation capacity. With these results, it is aimed to reach higher exploitation rate with given attention to landslide areas during planning of forest roads on the mountain areas such as Black Sea Region. For this reason, required importance must be given to planning of truck and logging roads. Ground analysis must be done and took care before during planning process of forest road network.

Determining the optimal index of heat stress in foundry, die casting and road construction industries using FAHP_Topsis

Directory of Open Access Journals (Sweden)

Maryam Dehghanipoor

2016-12-01

Full Text Available Introduction: Heat stress is one of the harmful risks in casting and die casting industries, which can not only cause work-related diseases but also can impair the performance and safety of workers. Since the indicators that are used to evaluate heat stress are very different, it is very difficult to choose a suitable index. The aim of this study was to determine the optimum heat stress index in foundry, die-cast, and road construction industries using FAHP and Topsis methods. Material and Method: In order to determine optimum heat stress index in foundry, die-cast, and road construction industries, first, the prioritization criteria were defined by experts (including ease of measurement, measurement accuracy, comprehensiveness, time, cost, and correlation. Then, considering these criteria, the best heat stress index was determined based on experts’ opinions and using FAHP and Topsis methods. Result: The results of this study suggest that given the current conditions and criteria, WBGT and P4SR is the best indices for foundry, die casting and construction. Conclusion: The results showed that according to comprehensiveness, accuracy and correlation criteria, the WBGT index is considered as the best indicator of heat stress assessment in foundry, die-cast and road construction industries. Moreover, the HSI ranked in the last place due to the complexity and cost of its calculation.

Impact of government and corporate strategy on the performance of technology projects in road construction

NARCIS (Netherlands)

Caerteling, Jasper; Halman, Johannes I.M.; Song, Michael; Song, Michael; Doree, Andries G.

2009-01-01

In this study, we focus on road construction and analyze technology development projects. Based on the business strategy literature and literature on technology policy, we test the relative importance of a firm's strategies and government as a buyer and champion. Our empirical findings stress the

Developing improved opportunities for the recycling and reuse of materials in road, bridge, and construction projects.

Science.gov (United States)

2014-12-01

The use of recycled and reused materials in transportation construction reduces consumption of non-renewable : resources. The objective of this research was to develop opportunities for improving the recycling and reuse of : materials in road and bri...

Beyond the material grave: Life Cycle Impact Assessment of leaching from secondary materials in road and earth constructions.

Science.gov (United States)

Schwab, Oliver; Bayer, Peter; Juraske, Ronnie; Verones, Francesca; Hellweg, Stefanie

2014-10-01

In industrialized countries, large amounts of mineral wastes are produced. They are re-used in various ways, particularly in road and earth constructions, substituting primary resources such as gravel. However, they may also contain pollutants, such as heavy metals, which may be leached to the groundwater. The toxic impacts of these emissions are so far often neglected within Life Cycle Assessments (LCA) of products or waste treatment services and thus, potentially large environmental impacts are currently missed. This study aims at closing this gap by assessing the ecotoxic impacts of heavy metal leaching from industrial mineral wastes in road and earth constructions. The flows of metals such as Sb, As, Pb, Cd, Cr, Cu, Mo, Ni, V and Zn originating from three typical constructions to the environment are quantified, their fate in the environment is assessed and potential ecotoxic effects evaluated. For our reference country, Germany, the industrial wastes that are applied as Granular Secondary Construction Material (GSCM) carry more than 45,000 t of diverse heavy metals per year. Depending on the material quality and construction type applied, up to 150 t of heavy metals may leach to the environment within the first 100 years after construction. Heavy metal retardation in subsoil can potentially reduce the fate to groundwater by up to 100%. One major challenge of integrating leaching from constructions into macro-scale LCA frameworks is the high variability in micro-scale technical and geographical factors, such as material qualities, construction types and soil types. In our work, we consider a broad range of parameter values in the modeling of leaching and fate. This allows distinguishing between the impacts of various road constructions, as well as sites with different soil properties. The findings of this study promote the quantitative consideration of environmental impacts of long-term leaching in Life Cycle Assessment, complementing site-specific risk

Strabo's roads

DEFF Research Database (Denmark)

Bekker-Nielsen, Tønnes

2017-01-01

in the Geography, and the world-view, of Strabo. Strabo did not take much interest in roads as artefacts or monuments, in the technology of road construction, or in the mythological and historical background of individual roads. He is primarily interested in roads from a functional point of view. For the general......To ancient geographers, roads were important not only as arteries of communication, but also as sources of information, since mileages measured along the Roman highways were among the very few precise distances available to the ancient geographer. This chapter explores the place of roads...... or the statesman, roads provide routes of communication; for the systematic geographer, they provide measured distances and directions. Through case studies of Spain, Gaul, Italy, Greece and Anatolia, this chapter attempts to reach a better understanding of the place of roads in Strabo’s universe, especially two...

The study of KBP of road construction workers of highway AIDS prevention project before and after intervention.

Science.gov (United States)

Liu, Dan; Dong, Si-Ping; Gao, Guang-Ming; Fan, Ming-Yu; Zhang, Zong-Jiu; Fang, Peng-Qian

2013-10-01

To get scientific basis for further health education through the research of the road construction workers' KBP before and after the interventions of highway AIDS prevention project. Multi-stage random sampling method was employeed to select workers of 8 sites from 14 sites along highway to investigate their AIDS knowledge, belief and performance (KBP) before and after highway AIDS prevention project. Over 90% of the investigated workers had ever heard about AIDS, and the non-skilled workers of lower educational level improved more after intervention. The correct answer rate of the three transmitting ways of AIDS of drivers which is the focused group of highway before and after intervention had the obvious statistical significance (Proad construction workers is effective and further health education of HIV prevention should be carried out among the road construction workers to improve their knowledge and awareness of avoiding the high-risk behaviors. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

An Evaluation of Forest Road Standards and Road Gradients in Turkey in View of FAO Criteria and Some EU Practices

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Sadık Çağlar

2009-04-01

Full Text Available Forest roads are one of the inevitable infrastructures in conducting forestry operations. Around 1000 km under standardized forest roads have been largely repaired in addition to construction of 1000 km new forest roads in Turkey. Implementing uniform road gradient along the road sections is very important in terms of transportation techniques and safety, as well as the geometrical standardizations of the forest road. In this study, current road standards, longitudinal gradient values and their limitations in forest road constructions recommended by Food and Agriculture Organization of the United Nations (FAO and some Europe Union (EU countries were examined. Firstly, the forest road standards and their gradient values have been defined in Turkish forest road construction practices. Afterwards, the forest road standards and the gradient values applied by FAO and some EU countries were presented, and finally, the specifications were examined by comparing them with the current practices in Turkish forestry.

Beyond the material grave: Life Cycle Impact Assessment of leaching from secondary materials in road and earth constructions

International Nuclear Information System (INIS)

Schwab, Oliver; Bayer, Peter; Juraske, Ronnie; Verones, Francesca; Hellweg, Stefanie

2014-01-01

Highlights: • We model environmental impacts of leaching from secondary construction material. • Industrial wastes in construction contain up to 45,000 t heavy metals per year (D). • In a scenario, 150 t are leached to the environment within 100 years after construction. • All heavy metals but As, Sb and Mo are adsorbed by 20 cm subsoil in this scenario. • Environmental impacts depend on material, pollutant, construction type, and geography. - Abstract: In industrialized countries, large amounts of mineral wastes are produced. They are re-used in various ways, particularly in road and earth constructions, substituting primary resources such as gravel. However, they may also contain pollutants, such as heavy metals, which may be leached to the groundwater. The toxic impacts of these emissions are so far often neglected within Life Cycle Assessments (LCA) of products or waste treatment services and thus, potentially large environmental impacts are currently missed. This study aims at closing this gap by assessing the ecotoxic impacts of heavy metal leaching from industrial mineral wastes in road and earth constructions. The flows of metals such as Sb, As, Pb, Cd, Cr, Cu, Mo, Ni, V and Zn originating from three typical constructions to the environment are quantified, their fate in the environment is assessed and potential ecotoxic effects evaluated. For our reference country, Germany, the industrial wastes that are applied as Granular Secondary Construction Material (GSCM) carry more than 45,000 t of diverse heavy metals per year. Depending on the material quality and construction type applied, up to 150 t of heavy metals may leach to the environment within the first 100 years after construction. Heavy metal retardation in subsoil can potentially reduce the fate to groundwater by up to 100%. One major challenge of integrating leaching from constructions into macro-scale LCA frameworks is the high variability in micro-scale technical and geographical factors

Beyond the material grave: Life Cycle Impact Assessment of leaching from secondary materials in road and earth constructions

Energy Technology Data Exchange (ETDEWEB)

Schwab, Oliver [Swiss Federal Institute of Technology Zurich, Institute of Environmental Engineering, John-von-Neumann-Weg 9, 8093 Zurich (Switzerland); Karlsruhe Institute of Technology, Institute for Geography and Geoecology, Adenauerring 20, 76131 Karlsruhe (Germany); Bayer, Peter, E-mail: bayer@erdw.ethz.ch [Swiss Federal Institute of Technology Zurich, Geological Institute, Sonneggstrasse 5, 8092 Zurich (Switzerland); Juraske, Ronnie [Swiss Federal Institute of Technology Zurich, Institute of Environmental Engineering, John-von-Neumann-Weg 9, 8093 Zurich (Switzerland); Verones, Francesca [Swiss Federal Institute of Technology Zurich, Institute of Environmental Engineering, John-von-Neumann-Weg 9, 8093 Zurich (Switzerland); Department of Environmental Science, Institute for Water and Wetland Research, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands); Hellweg, Stefanie [Swiss Federal Institute of Technology Zurich, Institute of Environmental Engineering, John-von-Neumann-Weg 9, 8093 Zurich (Switzerland)

2014-10-15

Highlights: • We model environmental impacts of leaching from secondary construction material. • Industrial wastes in construction contain up to 45,000 t heavy metals per year (D). • In a scenario, 150 t are leached to the environment within 100 years after construction. • All heavy metals but As, Sb and Mo are adsorbed by 20 cm subsoil in this scenario. • Environmental impacts depend on material, pollutant, construction type, and geography. - Abstract: In industrialized countries, large amounts of mineral wastes are produced. They are re-used in various ways, particularly in road and earth constructions, substituting primary resources such as gravel. However, they may also contain pollutants, such as heavy metals, which may be leached to the groundwater. The toxic impacts of these emissions are so far often neglected within Life Cycle Assessments (LCA) of products or waste treatment services and thus, potentially large environmental impacts are currently missed. This study aims at closing this gap by assessing the ecotoxic impacts of heavy metal leaching from industrial mineral wastes in road and earth constructions. The flows of metals such as Sb, As, Pb, Cd, Cr, Cu, Mo, Ni, V and Zn originating from three typical constructions to the environment are quantified, their fate in the environment is assessed and potential ecotoxic effects evaluated. For our reference country, Germany, the industrial wastes that are applied as Granular Secondary Construction Material (GSCM) carry more than 45,000 t of diverse heavy metals per year. Depending on the material quality and construction type applied, up to 150 t of heavy metals may leach to the environment within the first 100 years after construction. Heavy metal retardation in subsoil can potentially reduce the fate to groundwater by up to 100%. One major challenge of integrating leaching from constructions into macro-scale LCA frameworks is the high variability in micro-scale technical and geographical factors

Study on Plastic Coated Overburnt Brick Aggregate as an Alternative Material for Bituminous Road Construction

Directory of Open Access Journals (Sweden)

Dipankar Sarkar

2016-01-01

Full Text Available There are different places in India where natural stone aggregates are not available for constructional work. Plastic coated OBBA can solve the problem of shortage of stone aggregate to some extent. The engineers are always encouraged to use locally available materials. The present investigation is carried out to evaluate the plastic coated OBBA as an alternative material for bituminous road construction. Shredded waste plastics are mixed with OBBA in different percentages as 0.38, 0.42, 0.46, 0.50, 0.54, and 0.60 of the weight of brick aggregates. Marshall Method of mix design is carried out to find the optimum bitumen content of such bituminous concrete mix prepared by plastic coated OBBA. Bulk density, Marshall Stability, flow, Marshall Quotient, ITS, TSR, stripping, fatigue life, and deformations have been determined accordingly. Marshall Stability value of 0.54 percent of plastic mix is comparatively higher than the other mixes except 0.60 percent of plastic mix. Test results are within the prescribed limit for 0.54 percent of plastic mix. There is a significant reduction in rutting characteristics of the same plastic mix. The fatigue life of the mix is also significantly higher. Thus plastic coated OBBA is found suitable in construction of bituminous concrete road.

The Vaendoera test road, Sweden: A case study of long-term properties of roads constructed with MSWI bottom ash; Projekt Vaendoera: En studie av laangtidsegenskaper hos vaegar anlagda med bottenaska fraan avfallsfoerbraenning

Energy Technology Data Exchange (ETDEWEB)

Bendz, David; Arm, Maria; Westberg, Gunnar; Sjoestrand, Karin; Lyth, Martin; Wik, Ola [Swedish Geotechnical Inst., Linkoeping (Sweden); Flyhammar, Peter [Lund Inst. of Technology (Sweden). Dept. of Water Resources Engineering

2006-03-15

The accumulated effects of leaching and aging in a subbase layer of bottom ash were investigated in this study. The paved test road were constructed in 1987 in Linkoeping, Sweden, and has been used until the start of this study. The objective of this study was to investigate: (i) the accumulated effects of leaching and aging (ii) the accumulated effects of load and aging on the geotechnical properties (iii) the prerequisites for separate excavation of the bottom ash for possible reuse. The study started in September 2003 and included tests with falling weight deflectometer, triax testing on undisturbed core samples of bottom ash, sampling for chemical analysis. Three trenches were excavated in the test road, samples of the subbase layer and the subgrade were taken in the shaft walls and brought to the laboratory for leaching tests (EN 12457-2) and extraction, respectively. The extraction procedure was used to estimate extractable and chemically available fractions. It was found that the steady increase of stiffness which had been detected by falling weight deflectometer during the first years after construction had ceased. The undisturbed samples showed stiffness comparable with recently produced bottom ash from the same incineration plant, but lower stiffness if compared with the reference material of crushed rock. The permanent deformation was significantly larger for the samples compared with the crushed rock and recent (1999-2001) bottom ash from other incineration plants. The spatial distribution patterns of leachable easily soluble constituents reveal the existence of horizontal gradients, directed from the center of the road towards the shoulders of the road. This implies that horizontal transport by diffusion is the rate limiting leaching process for all easily soluble constituents underneath the pavement in a road. The bottom ash that was used in the sub-base layer was fresh at the time of the construction of the test road with a pH of about 11. Measured p

Density and moisture measurements by nuclear method and its application to compaction control in road construction

International Nuclear Information System (INIS)

Mohd Azmi Ismail

1994-01-01

The application of nuclear technique in civil engineering sector which emphasises on the in-situ density and moisture measurements of soil in road construction is discussed. The nuclear density-moisture gauge utilises both gamma-rays and neutrons for the determination of the density and moisture content, respectively. The knowledge on the density and moisture content will be used to evaluate the degree of compaction of the compacted layers. The technique offers not only a fast and non-destructive measurement but it is also accurate, economical and repeatable. A calibration equation which is stored in the built-in microprocessor is applicable for any type of soil. Corrections for the interferences from needless gamma-rays produced as a result of thermal neutrons interaction with certain nuclei for the density measurement and effects of hydrogen other than absorbed water for the moisture measurement are considered in the equation. This paper describes briefly the theory and the characteristics of the nuclear gauge and its application in road construction work

Road construction replaceable materials. An alternative to oil-based materials

International Nuclear Information System (INIS)

Deneuvillers, C.; Chappat, M.

2008-01-01

For some time the world has been subjected enormous upheavals with regard to energy resources: on one hand there is the steep rise in the price of oil and the other energy sources whose price depends on it; on the other hand, the prospects are that during the next 25 to 30 years oil resources will become increasingly scarce, which raises the problem of its replacement. This situation obviously raises the vital question of the present and future energy needs of each country, and, consequently, what type of energy. These are not only political issues but also issues for society. How could the roads sector help to find at least partial solutions? This paper will describe a policy adopted by a private sector construction company which is determined to apply the criteria of sustainable development and green chemistry in its products. Bitumen is a derivative of oil, can it be replaced? Most of the chemical products used in roads are petrochemical in nature, can they be replaced? Turning towards vegetable resources provides one way of reducing energy dependency. The paper demonstrates how this could be done, and at what price and with what precautions. This topic inevitably involves a discussion of the criteria of life-cycle analysis and an examination of how they can be applied in a clear manner. This response from industry has already provided some excellent results, which are described in this paper. It also attempts to show how vegetable resources may provide an opportunity for both developing and developed countries. The first could produce a new energy resource and increase their standard of living. The second could be a partial solution to their energy resources problems. Roads, which provide a universal link between different peoples, may still provide a future and hope. (authors)

Life cycle assessment of disposal of residues from municipal solid waste incineration: recycling of bottom ash in road construction or landfilling in Denmark evaluated in the ROAD-RES model.

Science.gov (United States)

Birgisdóttir, H; Bhander, G; Hauschild, M Z; Christensen, T H

2007-01-01

Two disposal methods for MSWI bottom ash were assessed in a new life cycle assessment (LCA) model for road construction and disposal of residues. The two scenarios evaluated in the model were: (i) landfilling of bottom ash in a coastal landfill in Denmark and (ii) recycling of bottom ash as subbase layer in an asphalted secondary road. The LCA included resource and energy consumption, and emissions associated with upgrading of bottom ash, transport, landfilling processes, incorporation of bottom ash in road, substitution of natural gravel as road construction material and leaching of heavy metals and salts from bottom ash in road as well as in landfill. Environmental impacts associated with emissions to air, fresh surface water, marine surface water, groundwater and soil were aggregated into 12 environmental impact categories: Global Warming, Photochemical Ozone Formation, Nutrient Enrichment, Acidification, Stratospheric Ozone Depletion, Human Toxicity via air/water/soil, Ecotoxicity in water/soil, and a new impact category, Stored Ecotoxicity to water/soil that accounts for the presence of heavy metals and very persistent organic compounds that in the long-term might leach. Leaching of heavy metals and salts from bottom ash was estimated from a series of laboratory leaching tests. For both scenarios, Ecotoxicity(water) was, when evaluated for the first 100 yr, the most important among the twelve impact categories involved in the assessment. Human Toxicity(soil) was also important, especially for the Road scenario. When the long-term leaching of heavy metals from bottom ash was evaluated, based on the total content of heavy metals in bottom ash, all impact categories became negligible compared to the potential Stored Ecotoxicity, which was two orders of magnitudes greater than Ecotoxicity(water). Copper was the constituent that gave the strongest contributions to the ecotoxicities. The most important resources consumed were clay as liner in landfill and the

Impacts of road construction and removal on the hydrologic and geochemical function of a fen peatland

Science.gov (United States)

Wells, C. M.; Petrone, R. M.; Sutherland, G.; Price, J. S.

2015-12-01

Linear disturbances such as roads cover vast swaths of northeastern Alberta, the majority of which are wetlands with shallow and local hydrologic connections. Thus, the effects of road construction on wetland hydrological pathways can have significant implications on water movement within the region, and by extension the productivity of vegetation communities and carbon sequestration. However, little is known about the effect that roads have on wetland hydrology. In 2013, a gravel road built within a fen peatland was reclaimed to evaluate hydrologic impacts post removal. Prior to removal, ground and surface water flow was obstructed leading to surface ponding, and vegetation mortality was observed on the up-gradient (wet) side of the road. Rebounding of the peat column was observed throughout the fen immediately following road removal in 2013 (maximum of 12 cm, mean of 2 cm), with modest but slightly smaller expansion in 2014. For both years, peat rebound was greatest in areas where the road was removed. Peat physical properties contrasted sharply between the reclaimed road (RR) peat and the adjacent, unimpacted peatland (UP). Surface bulk densities (pb, 0-10 cm) ranged from 0.1-0.25 g cm-3 along the RR compared to 0.02-0.07 g cm-3 for the UP and on average, pb for all depths were lower at the RR compared to the UP. Similar spatial patterns were observed for peat porosity. Correspondingly low horizontal saturated hydraulic conductivities (Kh) were observed along the RR compared to the UP, averaging 5.7x10-4 m s-1 and 1.7x10-3 m s-1, respectively. The local flow system across the RR and thus subsurface flow was impeded by almost half (0.4 m d-1) compared to flow observed within the UP (0.8 m d-1), leading to ponding on the upgradient side. A marked change in hydrophysical properties and ground and surface water flow patterns post road removal has implications for plant reestablishment and restoration and will form the basis of further study.

Bio-monitoring for the genotoxic assessment in road construction workers as determined by the buccal micronucleus cytome assay.

Science.gov (United States)

Çelik, Ayla; Yildirim, Seda; Ekinci, Seda Yaprak; Taşdelen, Bahar

2013-06-01

Buccal micronucleus cytome (BMCyt) assay monitors genetic damage, cell proliferation and cell death in humans exposed to occupational and environmental agents. BMCyt is used as an indicator of genotoxic exposure, since it is associated with chromosomal instability. There is little research on the occupational exposure among road construction workers for genotoxicity testing. In the present study, we evaluated MN frequencies and other nuclear changes, karyorrhexis (KR), karyolysis (KL), broken egg (BE), binucleate (BN), condensed chromatin cell (CCC), and picnotic cell (PC) in buccal mucosa cells of 40 road construction workers (twenty smokers and twenty non-smokers) and 40 control groups consisting of healthy persons (twenty smokers and twenty non-smokers). Microscopic observation was performed of 2000 cells per individual in both road construction workers and control group. In control and worker groups, for each person repair index (RI) was calculated via formula KR+L/BE+MN. The results showed a statistically significant increase in the frequency of MN in buccal epithelial cells of exposed group compared with control group (proad construction workers, RI is lower than the control group. There is a significant difference between workers and control group (proad paving operations are absorbed by workers and that asphalt fume exposure is able to significantly induce cytogenetic damage in buccal mucosa cells of workers after controlling some possible confounding factors, such as age, sex and smoking habits. In addition to determination of nuclear changes and the micronucleus, the determination of RI value presents a new approach to genotoxic bio-monitoring assessment studies of occupationally exposed population. Copyright © 2013 Elsevier Inc. All rights reserved.

LUR models for particulate matters in the Taipei metropolis with high densities of roads and strong activities of industry, commerce and construction.

Science.gov (United States)

Lee, Jui-Huna; Wu, Chang-Fu; Hoek, Gerard; de Hoogh, Kees; Beelen, Rob; Brunekreef, Bert; Chan, Chang-Chuan

2015-05-01

Traffic intensity, length of road, and proximity to roads are the most common traffic indicators in the land use regression (LUR) models for particulate matter in ESCAPE study areas in Europe. This study explored what local variables can improve the performance of LUR models in an Asian metropolis with high densities of roads and strong activities of industry, commerce and construction. By following the ESCAPE procedure, we derived LUR models of PM₂.₅, PM₂.₅ absorbance, PM₁₀, and PMcoarse (PM₂.₅-₁₀) in Taipei. The overall annual average concentrations of PM₂.₅, PM₁₀, and PMcoarse were 26.0 ± 5.6, 48.6 ± 5.9, and 23.3 ± 3.1 μg/m(3), respectively, and the absorption coefficient of PM₂.₅ was 2.0 ± 0.4 × 10(-5)m(-1). Our LUR models yielded R(2) values of 95%, 96%, 87%, and 65% for PM₂.₅, PM₂.₅ absorbance, PM₁₀, and PMcoarse, respectively. PM₂.₅ levels were increased by local traffic variables, industrial, construction, and residential land-use variables and decreased by rivers; while PM₂.₅ absorbance levels were increased by local traffic variables, industrial, and commercial land-use variables in the models. PMcoarse levels were increased by elevated highways. Road area explained more variance than road length by increasing the incremental value of 27% and 6% adjusted R(2) for PM₂.₅ and PM₁₀ models, respectively. In the PM₂.₅ absorbance model, road area and transportation facility explain 29% more variance than road length. In the PMcoarse model, industrial and new local variables instead of road length improved the incremental value of adjusted R(2) from 39% to 60%. We concluded that road area can better explain the spatial distribution of PM₂.₅ and PM₂.₅ absorbance concentrations than road length. By incorporating road area and other new local variables, the performance of each PM LUR model was improved. The results suggest that road area is a better indicator of traffic intensity rather

30 CFR 816.151 - Primary roads.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Primary roads. 816.151 Section 816.151 Mineral... roads. Primary roads shall meet the requirements of section 816.150 and the additional requirements of this section. (a) Certification. The construction or reconstruction of primary roads shall be certified...

Employment creation, technological efficiency, and distributional judgements : a case study in road construction / [by] G.W. Irvin

NARCIS (Netherlands)

G.W. Irvin (George)

1975-01-01

textabstractThe present article is concerned with the relationship between distributional and efficiency criteria and the objective of employment creation in a single sector, that of road construction. The work is based on a series of case studies carried out in Iran, one such study being presented

30 CFR 817.151 - Primary roads.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Primary roads. 817.151 Section 817.151 Mineral... roads. Primary roads shall meet the requirements of § 817.150 and the additional requirements of this section. (a) Certification. The construction or reconstruction of primary roads shall be certified in a...

Erosion and sedimentation control on roads and construction sites in the Federated States of Micronesia

Science.gov (United States)

Robert R. Ziemer; Walter F. Megahan

1991-01-01

Enclosed is the report that Walt Megahan and I prepared following our trip to States of Micronesia. As we discussed earlier, we felt that it was redundant to produce a set of guidelines for road construction since the FAO Conservation Guide 13/5 that was issued in 1989 (ISBN 92-5-102789-X) covers the subject extensively. We felt that we could best tailor this report to...

25 CFR 265.3 - Roads prohibited.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Roads prohibited. 265.3 Section 265.3 Indians BUREAU OF... ON INDIAN RESERVATIONS § 265.3 Roads prohibited. (a) Within the boundaries of this officially... highways, roads, truck trails, work roads, and all other types of ways constructed to make possible the...

Soil retention of hexavalent chromium released from construction and demolition waste in a road-base-application scenario.

Science.gov (United States)

Butera, Stefania; Trapp, Stefan; Astrup, Thomas F; Christensen, Thomas H

2015-11-15

We investigated the retention of Cr(VI) in three subsoils with low organic matter content in laboratory experiments at concentration levels relevant to represent leachates from construction and demolition waste (C&DW) reused as unbound material in road construction. The retention mechanism appeared to be reduction and subsequent precipitation as Cr(III) on the soil. The reduction process was slow and in several experiments it was still proceeding at the end of the six-month experimental period. The overall retention reaction fit well with a second-order reaction governed by actual Cr(VI) concentration and reduction capacity of the soil. The experimentally determined reduction capacities and second-order kinetic parameters were used to model, for a 100-year period, the one-dimensional migration of Cr(VI) in the subsoil under a layer of C&DW. The resulting Cr(VI) concentration would be negligible below 7-70 cm depth. However, in rigid climates and with high water infiltration through the road pavement, the reduction reaction could be so slow that Cr(VI) might migrate as deep as 200 cm under the road. The reaction parameters and the model can form the basis for systematically assessing under which scenarios Cr(VI) from C&DW could lead to an environmental issue for ground- and receiving surface waters. Copyright © 2015 Elsevier B.V. All rights reserved.

Simulation of tunneling construction methods of the Cisumdawu toll road

Science.gov (United States)

Abduh, Muhamad; Sukardi, Sapto Nugroho; Ola, Muhammad Rusdian La; Ariesty, Anita; Wirahadikusumah, Reini D.

2017-11-01

Simulation can be used as a tool for planning and analysis of a construction method. Using simulation technique, a contractor could design optimally resources associated with a construction method and compare to other methods based on several criteria, such as productivity, waste, and cost. This paper discusses the use of simulation using Norwegian Method of Tunneling (NMT) for a 472-meter tunneling work in the Cisumdawu Toll Road project. Primary and secondary data were collected to provide useful information for simulation as well as problems that may be faced by the contractor. The method was modelled using the CYCLONE and then simulated using the WebCYCLONE. The simulation could show the duration of the project from the duration model of each work tasks which based on literature review, machine productivity, and several assumptions. The results of simulation could also show the total cost of the project that was modeled based on journal construction & building unit cost and online websites of local and international suppliers. The analysis of the advantages and disadvantages of the method was conducted based on its, wastes, and cost. The simulation concluded the total cost of this operation is about Rp. 900,437,004,599 and the total duration of the tunneling operation is 653 days. The results of the simulation will be used for a recommendation to the contractor before the implementation of the already selected tunneling operation.

7 CFR 760.305 - Eligible grazing losses.

Science.gov (United States)

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Eligible grazing losses. 760.305 Section 760.305... grazing losses. (a) A grazing loss due to drought is eligible for LFP only if the grazing loss for the... period for the specific type of grazing land or pastureland for the county.) (b) A grazing loss is not...

Degradation in urban air quality from construction activity and increased traffic arising from a road widening scheme.

Science.gov (United States)

Font, Anna; Baker, Timothy; Mudway, Ian S; Purdie, Esme; Dunster, Christina; Fuller, Gary W

2014-11-01

Road widening schemes in urban areas are often proposed as a solution to traffic congestion and as a means of stimulating economic growth. There is however clear evidence that new or expanded roads rapidly fill with either displaced or induced traffic, offsetting any short-term gains in eased traffic flows. What has not been addressed in any great detail is the impact of such schemes on air quality, with modelled impact predictions seldom validated by measurements after the expansion of road capacity. In this study we made use of a road widening project in London to investigate the impact on ambient air quality (particulate matter, NOX, NO2) during and after the completion of the road works. PM10 increased during the construction period up to 15 μg m(-3) during working hours compared to concentrations before the road works. A box modelling approach was used to determine a median emission factor of 0.0022 kg PM10 m(-2) month(-1), three times larger than that used in the UK emission inventory (0.0007 kg PM10 m(-2) month(-1)). Peaks of activity released 0.0130 kg PM10 m(-2) month(-1), three and eight times smaller than the peak values used in the European and US inventories. After the completion of the widening there was an increase in all pollutants from the road during rush hour: 2-4 μg m(-3) for PM10; 1 μg m(-3) for PM2.5; 40 and 8 μg m(-3) for NOX and NO2, respectively. NO2 EU Limit Value was breached after the road development illustrating a notable deterioration in residential air quality. Additionally, PM10, but not PM2.5, glutathione dependent oxidative potential increased after the road was widened consistent with an increase in pro-oxidant components in the coarse particle mode, related to vehicle abrasion processes. These increased air pollution indices were associated with an increase in the number of cars, taxis and LGVs. Copyright © 2014. Published by Elsevier B.V.

Modeling the grazing effect on dry grassland carbon cycling with modified Biome-BGC grazing model

Science.gov (United States)

Luo, Geping; Han, Qifei; Li, Chaofan; Yang, Liao

2014-05-01

Identifying the factors that determine the carbon source/sink strength of ecosystems is important for reducing uncertainty in the global carbon cycle. Arid grassland ecosystems are a widely distributed biome type in Xinjiang, Northwest China, covering approximately one-fourth the country's land surface. These grasslands are the habitat for many endemic and rare plant and animal species and are also used as pastoral land for livestock. Using the modified Biome-BGC grazing model, we modeled carbon dynamics in Xinjiang for grasslands that varied in grazing intensity. In general, this regional simulation estimated that the grassland ecosystems in Xinjiang acted as a net carbon source, with a value of 0.38 Pg C over the period 1979-2007. There were significant effects of grazing on carbon dynamics. An over-compensatory effect in net primary productivity (NPP) and vegetation carbon (C) stock was observed when grazing intensity was lower than 0.40 head/ha. Grazing resulted in a net carbon source of 23.45 g C m-2 yr-1, which equaled 0.37 Pg in Xinjiang in the last 29 years. In general, grazing decreased vegetation C stock, while an increasing trend was observed with low grazing intensity. The soil C increased significantly (17%) with long-term grazing, while the soil C stock exhibited a steady trend without grazing. These findings have implications for grassland ecosystem management as it relates to carbon sequestration and climate change mitigation, e.g., removal of grazing should be considered in strategies that aim to increase terrestrial carbon sequestrations at local and regional scales. One of the greatest limitations in quantifying the effects of herbivores on carbon cycling is identifying the grazing systems and intensities within a given region. We hope our study emphasizes the need for large-scale assessments of how grazing impacts carbon cycling. Most terrestrial ecosystems in Xinjiang have been affected by disturbances to a greater or lesser extent in the past

A case study of intelligent compaction used in road upgrades

CSIR Research Space (South Africa)

Leyland, R

2014-08-01

Full Text Available to traditional testing methods. In a field study numerous different IC systems where used during construction of a number of experimental road sections in South Africa. These sections formed part of a road upgrade project typical of most road construction...

Enhanced sensitivity of a mountain bog to climate change as a delayed effect of road construction

Directory of Open Access Journals (Sweden)

P. von Sengbusch

2015-01-01

Full Text Available Trees of Pinus rotundata (bog pine characterise many bogs in the mid-altitude mountains of central Europe (Switzerland, East and South Germany, Czech Republic. The research described here focuses on recent changes in the growth of bog pine on the Ennersbacher Moor, a mountain mire in the Black Forest (south-west Germany. An increase in the cover of bog pine is usually caused by drainage and subsequent drawdown of the water table. However, this bog has not been drained or directly disturbed in any other way. One possible explanation is that a road constructed in 1983 along one margin of the bog has diverted part of its water supply. Even though the road was designed to conduct potentially salt-contaminated drainage water away from the bog, its construction did not cause an immediate vegetation response in the 1980s and 1990s. Therefore, I hypothesise that it enhanced the sensitivity of the bog to climatic stress, predisposing it to a succession that was eventually triggered by a series of drought years in 2009–2011. Data collected near the centre of the bog over the period 1998–2014 indicate not only a distinct change in the relationship between height and trunk circumference of the trees, but also an increase of dwarf shrub cover and changes in the composition of Sphagnum communities. Although the pH of near-surface water may have increased slightly over this period, pH and EC values remain within typical ranges for raised bogs in the Black Forest. Examination of peat profiles reveals that the peat is more highly humified now than it was in 2002, and water table records from 2012–2014 show a greater amplitude of fluctuation than water table data collected in 1998–2001. Even though its mean level is only 105 mm below the ground surface, the water table is now observed to fall rapidly to depths of at least 350 mm during both wet and dry summers. Mapping surface (mesotopography and flow lines from the adjacent slope shows that the

Recycled aggregate in road construction following the Spanish General Technical Specifications for Roads and Bridge Works (PG-3: a case study

Directory of Open Access Journals (Sweden)

Martín-Morales, M.

2013-03-01

Full Text Available This research characterizes four samples of recycled aggregate for their potential use in road construction projects in consonance with the Spanish General Technical Specifications for Roads and Bridge Works (PG-3. Although some fractions were of sufficient quality for the construction of embankments, backfills, and quarry-run fills, they were ultimately found to be unsuitable for the construction of underground drainage, granular structural layers, soil stabilization and concrete pavements. They were negatively evaluated because of their particle size distribution and sulfate content. Nevertheless, the quality of this recycled aggregate could be substantially improved by manually removing the gypsum before the crushing process at the plant or by selecting the material with greater care at the beginning of the process. Finally, we suggest that Construction and Demolition (C&D waste plant managers should modify the manufacturing process to obtain a suitable particle size distribution in accordance with PG-3 requirements and the projected use of the aggregate.

En esta investigación se han caracterizado cuatro muestras de árido reciclado para su potencial uso en obras de carreteras en España siguiendo el Pliego de Prescripciones Técnicas Generales para Obras de Carreteras y Puentes (PG-3. Aunque algunas fracciones presentaron suficiente calidad para la construcción de terraplenes, rellenos localizados y rellenos todo en uno, resultaron inadecuadas para la construcción de drenes subterráneos, zahorras, suelos estabilizados y pavimentos de hormigón. Obtuvieron una evaluación negativa en cuanto a distribución granulométrica y contenido en sulfatos. No obstante, la calidad de este árido reciclado podría mejorar sustancialmente eliminando manualmente el yeso antes de la trituración en planta o seleccionando el material con un mayor cuidado al inicio del proceso. Finalmente, recomendamos que los empresarios de las plantas de residuos

Prerequisites for an effective use of ashes in road construction; Foerutsaettningar foer att askor kommer till anvaendning i vaegar

Energy Technology Data Exchange (ETDEWEB)

Kaerrman, Erik; Moeffaert, Denis van [Scandiaconsult Sverige AB, Stockholm (Sweden); Bjurstroem, Henrik; Berg, Magnus [AaF Energi och Miljoe AB, Stockholm (Sweden); Svedberg, Bo [Luleaa Univ. of Technology (Sweden)

2004-01-01

The aim of this project was to compile how different EU-countries have overcome the obstacles for the use of ashes in road constructions and conclude what has to be done in Sweden. An assumption and starting point for the study is that the use of ashes is beneficial. The study is focused on other EU countries through interviews with relevant actors in Belgium, Netherlands, France, England, Finland and Denmark. The conditions in these countries vary. Netherlands and Denmark were pioneers and have today many years of experience of using ashes in road construction. At the time for this investigation there were however drawbacks - in Netherlands due to mismanagement of ashes in large road constructions and in Denmark because of the introduction of stricter regulations. Belgium and England are making efforts towards recycling of ashes although only small amounts have been used hitherto. In some regions of France, ashes are used to a vast degree, which is mainly due to a strong network of material suppliers marketing ashes together. In Finland, finally, a comprehensive program for research and development were undertaken during the 1990s. An output of this program was guidelines, which facilitate the use of ashes. Typical obstacles for the use of recycled materials in constructions in Sweden have in previous projects been identified as 1) ambiguous laws and regulations, 2) lack of experiences, 3) weak economical incentives, 4) material-related decisions are made too late in project planning and, 5) lack of methods for showing the benefits of recycling. The experiences from the studied countries confirm that points 1, 3 and partly 2 also are valid there. Lack of competence can only be reconciled by active marketing. Point 5 can be overcome by the use of environmental system analysis (ESA) in which both the road construction and alternative management (e.g. disposal) of ashes are included. This type of analyses has not been carried out in the studied countries (except a

The grazing capacity of sweetveld: 2. A model to estimate grazing ...

African Journals Online (AJOL)

The relations between grazing capacity and three independent variables were investigated in the False Thornveld of the Eastern Cape. The variables were veld condition, rainfall and density of woody species. These relations were used to develop a preliminary model to assess grazing capacity in the veld type. Despite its ...

Practical implications of the relation between the clay mineral content and the plasticity index of dolerite road construction material

CSIR Research Space (South Africa)

Kleyn, E

2009-04-01

Full Text Available or the introduction of more expensive commercially manufactured materials. For this reason the naturally occurring materials have to be better assessed and utilised. The weathered rock most widely used for road construction in South Africa, yet also notorious for its...

The Effect of Different Type of Herbivores, Grazing Types and Grazing Intensities on Alpine Basiphillous Vegetation of the Romanian Carpathians

Science.gov (United States)

Ballová, Zuzana; Pekárik, Ladislav; Šibík, Jozef

2017-04-01

The major purpose of the present study was to test the hypothesis that there are significant differences in vegetation structure, plant species composition, and soil chemical properties in relation to type of grazing animals, various levels of grazing intensity and grazing type, and if potential differences alter with ecosystem productivity (increase in more productive ecosystems). The study was conducted in three mountain ranges of the Romanian Carpathians with a predominance of alkaline substrates (the Bucegi Mts, the Little Retezat Mts and the Ceahlău Massif). Statistical analyses were performed in R statistical software environment. The effects of grazing animals (cattle, horses and sheep), grazing types (fence, regular, irregular) and grazing intensity (low, medium, high) on the community structure were tested using ordination methods. In the case of soil properties, General Linear Mixed Model was applied. Special statistical approach eliminated the differences between the examined mountains and sites. Type of grazing animal does not significantly influence species cover but it is related to specific species occurrence. According to our results, grazing horses had similar effects as cattle compared to sheep. Grazing in restricted areas (surrounded by fence) and regular unrestricted grazing were more similar if compared to irregular grazing. When comparing the intensity of grazing, high and medium intensity were more similar to each other than to the low intensity grazing. Cattle grazed sites had significantly higher lichens cover, while the sheep patches were covered with increased overall herb layer (forbs, graminoids and low shrubs together). Medium grazing intensity decreased the lichens cover, cover of overall herb layer, and total vegetation cover compared to high and low grazing intensity. Grazing type had important impact on the lichens cover and cover of overall herb layer. The lichens cover appeared to decrease while the cover of overall herb layer

Multiyear nutrient removal performance of three constructed wetlands intercepting tile drain flows from grazed pastures.

Science.gov (United States)

Tanner, Chris C; Sukias, James P S

2011-01-01

Subsurface tile drain flows can be a major s ource of nurient loss from agricultural landscapes. This study quantifies flows and nitrogen and phosphorus yields from tile drains at three intensively grazed dairy pasture sites over 3- to 5-yr periods and evaluates the capacity of constructed wetlands occupying 0.66 to 1.6% of the drained catchments too reduce nutrient loads. Continuous flow records are combined with automated flow-proportional sampling of nutrient concentrations to calculate tile drain nutrient yields and wetland mass removal rates. Annual drainage water yields rangedfrom 193 to 564 mm (16-51% of rainfall) at two rain-fed sites and from 827 to 853 mm (43-51% of rainfall + irrigation) at an irrigated site. Annually, the tile drains exported 14 to 109 kg ha(-1) of total N (TN), of which 58 to 90% was nitrate-N. Constructed wetlands intercepting these flows removed 30 to 369 gTN m(-2) (7-63%) of influent loadings annually. Seasonal percentage nitrate-N and TN removal were negatively associated with wetland N mass loadings. Wetland P removal was poor in all wetlands, with 12 to 115% more total P exported annually overall than received. Annually, the tile drains exported 0.12 to 1.38 kg ha of total P, of which 15 to 93% was dissolved reactive P. Additional measures are required to reduce these losses or provide supplementary P removal. Wetland N removal performance could be improved by modifying drainage systems to release flows more gradually and improving irrigation practices to reduce drainage losses.

36 CFR 212.5 - Road system management.

Science.gov (United States)

2010-07-01

... construction, reconstruction, decommissioning, and maintenance. (2) Identification of unneeded roads... share of the costs. (d) Maintenance and reconstruction of National Forest System roads by users—(1... to cover maintenance or reconstruction of roads shall be used for the purposes deposited, except that...

Construction dust amelioration techniques.

Science.gov (United States)

2012-04-01

Dust produced on seasonal road construction sites in Alaska is both a traffic safety and environmental concern. Dust emanating from : unpaved road surfaces during construction severely reduces visibility and impacts stopping sight distance, and contr...

Spanish experiences with marginal and special materials on the construction of road embankments

International Nuclear Information System (INIS)

Cano Linares, H.; Perucho Martinez, A.

2015-01-01

The use of existing materials along the alignment of a road is an essential problem within the Sustainable Development policies, which is being promoting worldwide since a long time. In the Word road Association (PIARC-AIPCR) this subject has being investigated by different Technical Committees during last decades. Additionally, the review of the article 330 Embankment of PG-3 (FOM 1382/2002) has opened the door to new non-conventional materials, as wastes and artificial materials, to be used on embankments. This could come to adequate solutions, technically, and environmentally, contributing with national legislation on valorisation policies. In this sense, the use of marginal materials and wastes con represent and important save on natural resources and dumping sites. In Spain, some experiences with marginal materials and wastes have being carried out. The work presented has consisted in compiling and analysing the experiences executed with marginal materials and wastes on Spanish road embankments. Although there are many other cases, 24 cases published with adequate information have being analysed, summarising aspects as: materials problems arrangement solutions or treatments employed. Analysing these experiences and making them public can be a way to transmit confidence, help to improve knowledge, and progress on the preparation of recommendations. This work has being carried out on the frame of the Project Geotechnical Engineering, Materials and Structures and Impact of Infrastructure in Civil engineering (TTIGEM), within the frame Program Border Cooperation Spain-External Borders (POCTEFEX); particularly in the Activity 2 related to Technology Transfer of Construction Materials, including marginal materials and wastes. (Author)

Quantification of Gravel Rural Road Sediment Production

Science.gov (United States)

Silliman, B. A.; Myers Toman, E.

2014-12-01

Unbound rural roads are thought to be one of the largest anthropogenic sources of sediment reaching stream channels in small watersheds. This sediment deposition can reduce water quality in the streams negatively impacting aquatic habitat as well as impacting municipal drinking water sources. These roads are thought to see an increase in construction and use in southeast Ohio due to the expansion of shale gas development in the region. This study set out to quantify the amount of sediment these rural roads are able to produce. A controlled rain event of 12.7 millimeters of rain over a half hour period was used to drive sediment production over a 0.03 kilometer section of gravel rural road. These 8 segments varied in many characteristics and produced from 2.0 to 8.4 kilograms of sediment per 0.03 kilometers of road with the average production over the 8 segments being 5.5 kilograms of sediment. Sediment production was not strongly correlated with road segment slope but traffic was found to increase sediment production from 1.1 to 3.9 times as much sediment after traffic use. These results will help inform watershed scale sediment budgeting, and inform best management practices for road maintenance and construction. This study also adds to the understanding of the impacts of rural road use and construction associated with the changing land use from agricultural to natural gas extraction.

Cost, performance, and esthetic impacts of an experimental forest road in Montana

Science.gov (United States)

Rulon B. Gardner

1978-01-01

An experimental logging road designed to minimize environmental and esthetic impact was constructed in northwest Montana. The road was single-lane (14-foot finished surface, 3-foot ditch), constructed along the contour. Esthetically, the single-lane experimental road was judged far superior to existing roads on the forest.

Simulating grazing practices in a complete livestock system model: estimating soil carbon storage and greenhouse gas emissions in grazed versus un-grazed agroecosystems using the Manure-DNDC model

Science.gov (United States)

Campbell, E. E.; Dorich, C.; Contosta, A.; Varner, R. K.

2017-12-01

In livestock agroecosystems, the combined contributions of enteric fermentation, manure management, and livestock grazing and/or feed production play an important role in agroecosystem carbon (C) storage and GHG losses, with complete livestock system models acting as important tools to evaluate the full impacts of these complex systems. The Manure-DeNitrification-DeComposition (DNDC) model is one such example, simulating impacts on C and nitrogen cycling, estimating methane, carbon dioxide, nitrous oxide, and ammonium dynamics in fields, manure storage, and enteric emissions. This allows the evaluation of differences in GHG and soil C impacts between conventional and organic dairy production systems, which differ in their use of grazed pasture versus confined feeding operations. However, Manure-DNDC has received limited testing in representing variations in grazed pasture management (i.e. intensive rotational grazing versus standard grazing practices). Using a set of forage biomass, soil C, and GHG emissions data collected at four sites across New England, we parameterized and validated Manure-DNDC estimations of GHG emissions and soil C in grazed versus un-grazed systems. Soil observations from these sites showed little effect from grazing practices, but larger soil carbon differences between farms. This may be due to spatial variation in SOC, making it difficult to measure and model, or due to controls of edaphic properties that make management moot. However, to further address these questions, model development will be needed to improve Manure-DNDC simulation of rotational grazing, as high stocking density grazing over short periods resulted in forage not re-growing sufficiently within the model. Furthermore, model simulations did not account for variation in interactions between livestock and soil given variability in field microclimates, perhaps requiring simulations that divide a single field into multiple paddocks to move towards more accurate evaluation of

Quantification of carbon footprint of urban roads via life cycle assessment

DEFF Research Database (Denmark)

Mao, Ruichang; Duan, Huabo; Dong, Dan

2017-01-01

assessment method. For given years (ranged from 2004 to 2013), various activities of urban roads (e.g. newly planned road construction, maintenance of road in use, and road renovation and demolition) have been examined in this study. The results show that the total carbon footprint from urban roads...... in Shenzhen was 260 (±20) thousand tons CO2e in 2013. The major contributor was the materials use (embodied impact) from newly constructed roads, which accounts for 52.3% of the total carbon footprint, followed by the maintenance stage (24.3%). The eco-design process of road construction plays a vital role...... studies attempted to examine the impacts from transport infrastructure, especially at a city or country level. This paper, taking Shenzhen in China (a fast developing megacity) as the case study, is specially designed to quantify the carbon footprint of the urban roads by using streamlined life cycle...

Reliability-based optimization design of geosynthetic reinforced road embankment.

Science.gov (United States)

2014-07-01

Road embankments are typically large earth structures, the construction of which requires for large amounts of competent fill soil. In order to limit costs, the utilization of geosynthetics in road embankments allows for construction of steep slopes ...

Snow as building material for construction of technological along-the-route roads of main pipelines

Science.gov (United States)

Merdanov, S. M.; Egorov, A. L.; Kostyrchenko, V. A.; Madyarov, T. M.

2018-05-01

The article deals with the process of compacting snow in a closed volume with the use of vacuum processing for the construction of technological along-the-route roads of main pipelines. The relevance of the chosen study is substantiated; methods and designs for snow compaction are considered. The publication activity and defenses of doctoral and candidate dissertations on the research subject are analyzed. Patent analysis of existing methods and equipment for snow compaction with indication of their disadvantages is carried out. A design calculation was carried out using computer programs in which a strength calculation was performed to identify the most stressed places in the construction of a vibrating hydraulic tyre-type roller. A 3D model of the experimental setup was developed.

25 CFR 166.307 - Will the grazing capacity be increased if I graze adjacent trust or non-trust rangelands not...

Science.gov (United States)

2010-04-01

... § 166.307 Will the grazing capacity be increased if I graze adjacent trust or non-trust rangelands not... trust or non-trust rangeland in common with the permitted land. Grazing capacity will be established... 25 Indians 1 2010-04-01 2010-04-01 false Will the grazing capacity be increased if I graze...

Use of wood ash for road stabilisation

International Nuclear Information System (INIS)

Lagerkvist, A.; Lind, B.

2009-01-01

Due to warmer winters in Sweden, the bearing capacity of forestry roads has become increasingly problematic in recent years. Road stabilization is needed in order to get timber out from the forests. This usually involves the addition of cement to the road body. However, wood ash is a possible substitute for cement because it has similar properties. Using wood ash has the added advantage of saving landfill space. This paper presented an ongoing laboratory study on leaching and mechanical stability, as well as frost-sensitivity using a 30 per cent ash addition to natural soils for reinforcing a forestry road near Timra in central Sweden. The road was being monitored with regard to environmental impact and mechanical properties. The paper discussed the potential of biofuel ashes and the increasing need to reinforce infrastructure due to climate change. The environmental impact from ash use in road constructions was then addressed. It was concluded that the application of ash in road construction would help to strengthen forest roads, make them more resistant to climatic change and render them accessible year-round. 32 refs., 3 tabs., 2 figs.

Role of asphalt paver productivity in direction development of road mechanical engineering

Directory of Open Access Journals (Sweden)

Karpushko Marina

2017-01-01

Full Text Available Road construction machinery is one of the largest and stable sectors of national economy. With the help of road-building machinery, construction, maintenance and repair of highways are carried out. Modern system of road and building machines is a complex of high-performance machines and mechanisms, of large and small capacity and productivity. Expansion of paved roads network of both federal and local values, use of resource-saving technologies, increasing of pace and quality of work, ensuring of reliability and durability of highways have a major impact on the development of road construction machinery. The level of foreign road and construction machinery puts forward complex requirements for compliance with world safety and environmental standards, increasing equipment mobility, expanding areas of effective use and, finally, increasing its capacity and productivity. Article contains approach to the calculation of the operational productivity of asphalt pavers that takes into account technical characteristics and conditions of works production and contributes to the reliability of decisions on organization and management of road maintenance works on urban roads.

36 CFR 293.7 - Grazing of livestock.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Grazing of livestock. 293.7...-PRIMITIVE AREAS § 293.7 Grazing of livestock. (a) The grazing of livestock, where such use was established..., shall be permitted to continue under the general regulations covering grazing of livestock on the...

50 CFR 35.9 - Livestock grazing.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Livestock grazing. 35.9 Section 35.9... NATIONAL WILDLIFE REFUGE SYSTEM WILDERNESS PRESERVATION AND MANAGEMENT General Rules § 35.9 Livestock grazing. (a) The grazing of livestock, where established prior to the date of legislation which designates...

Mortality of a cohort of road construction and maintenance workers with work disability compensation.

Science.gov (United States)

d'Errico, A; Mamo, C; Tomaino, A; Dalmasso, M; Demaria, M; Costa, G

2002-01-01

Surveillance systems of occupational mortality are useful tools to identify cases of diseases suspected as occupational and to monitor their occurrence over time, in space and in population subgroups. Many surveillance systems make use of administrative data in which information about occupations and/or economic sectors of the subjects enrolled is reported, such as death certificates, hospital discharge data, census data, tax and pension records, and workers' compensation archives. In the present study we analyzed the mortality of a cohort of road construction and maintenance workers enrolled through the Italian national archive of work disability compensations, also in order to evaluate the possible use of this administrative source to monitor occupational mortality. 8,000 subjects (7,879 males) receiving a disability compensation while working in the "road construction and maintenance" sector were identified from INAIL (National Institute for Insurance of Accidents at Work) archives. Vital status of these subjects was ascertained using the information available in INAIL archives and in the national tax register. For those found to be deceased from INAIL or tax archives, or without any information on vital status, a mail follow-up was started. We considered as observation period the years from 1980 to 1993. A record linkage with the ISTAT (Italian Institute of Statistics) national mortality registry was performed and the cause of death was retrieved for 964 out of 1,259 subjects. The analysis was restricted to males, leaving altogether 863 observed deaths with ascertained cause (84.7% of 1,019 total male deaths). SMR for overall mortality and PMR for specific cause mortality were computed, using the general Italian male population as reference. Overall mortality was significantly reduced (SMR = 79.0; 95% CI = 74.2-84.0). Proportional mortality analysis revealed significant excess risks for all malignant tumours (332 deaths, PMR = 1.08) and for digestive diseases

Road binders and energy savings. Strassenbau und Energie, Verwendung energiesparender Bindemittel

Energy Technology Data Exchange (ETDEWEB)

1987-01-01

This report is the outcome of a joint research project carried through by an international group of experts. The object was to establish whether current advances in research and practice permit to reduce energy consumption, especially the consumption of petroleum products, by making substitution, either in part or in full, for traditional binders in the construction, maintenance and strengthening of road pavements. The first part deals with bituminous binders, the second part is dedicated to hydraulic binders. As regards the possibility to make substitution for bitumen, the following materials are investigated: coal tar, sulfur, plastics, lignin, and natural rock impregnated with carbohydrates. The modification of the properties of bitumens (through polymers or rubber wastes), the use of emulsions, and the recovery of old road construction materials are dealt with in separate chapters. As regards hydraulic binders, the report investigates cements of low energy content, industrial by-products, and natural materials with hydraulic or pozzolanic properties as well as substandard materials. A separate chapter is dedicated to the possibility of reducing the thickness of the bituminous road cover over road bases with hydraulic binders. The appendix contains detailed energy balances for current road construction materials and pavement constructions. The report is meant to constitute a decision-aid for road authorities and contractors working in the public sector in choosing appropriate road construction materials and techniques on the basis of rational criteria. (orig.)

Effect of Grazing on Forage Quality and Quantity for Ungulates of ...

African Journals Online (AJOL)

This study examined the effect of grazing as simulated by clipping on forage quality and quantity in terms of above ground biomass, live, total production and nutrients content of forages utilized by ungulates of Kainji Lake National Park. Three 2.5m by 2.5m plots were constructed in the three main vegetation communities in ...

36 CFR 223.37 - Revegetation of temporary roads.

Science.gov (United States)

2010-07-01

... roads. 223.37 Section 223.37 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF... Provisions § 223.37 Revegetation of temporary roads. Timber sale contracts, permits and other documents... roads constructed or used thereunder so as to permit the reestablishment by artificial or natural means...

Modelling the impact of roads on regional population of Moor frogs (Rana arvalis)

DEFF Research Database (Denmark)

Pontoppidan, Maj-Britt

for decisions concerning road lay-out and mitigation measures. As model species was chosen the Moor frog (Rana arvalis). Populations of Moor frogs are assumed to follow a pattern of metapopulation dynamics, with colonisation, extinction and recolonisation of suitable habitat patches. Thus, road constructions...... to be constructed and analysed. The first scenario should be a map of the area as it is before the planned road construction (scenario 0). This analysis measures the ecological performance of the original landscape and is a reference against which other scenarios are to be compared. The second map (scenario 1......) should show the landscape as it is expected to be after the road constructions. In combination, the analyses of scenario 0 and scenario 1 make it possible to assess the effect of road construction on connectivity and population persistence. The analyses also constitute the basis for planning...

A two reservoir model to predict Escherichia coli losses to water from pastures grazed by dairy cows.

Science.gov (United States)

Muirhead, R W; Monaghan, R M

2012-04-01

Animal agriculture has been identified as an important source of diffuse faecal microbial pollution of water. Our current understanding of the losses of faecal microbes from grazed pasture systems is however poor. To help synthesise our current knowledge, a simple two reservoir model was constructed to represent the faecal and environmental sources of Escherichia coli found in a grazed pastoral system. The size of the faecal reservoir was modelled on a daily basis with inputs from grazing animals, and losses due to die-off of E. coli and decomposition of the faecal material. Estimates were made of transport coefficients of E. coli losses from the two reservoirs. The concentration of E. coli measured in overland flow and artificial drainage from grazed plots, used for calibration of the model, showed a significant (Ppasture systems. Research is needed to understand the behaviour and impact of this environmental reservoir. Scenario analysis using the model indicated that rather than manipulating the faecal material itself post defecation, mitigation options should focus on manipulating grazing management. Copyright © 2011 Elsevier Ltd. All rights reserved.

Noise Costs from Road Transport

Science.gov (United States)

Margorínová, Martina; Trojanová, Mária; Decký, Martin; Remišová, Eva

2018-06-01

Building and improving road infrastructure in Slovakia is currently influenced by the amount of state funding. Therefore, it is necessary to determine the effectiveness of each proposed solution of road project, which is based on life-cycle costs. Besides capital costs, social costs are also important, which valued the negative impacts due to road construction and operation on road users, the environment, and the population living in the affected area. Some components of social costs have shortcomings in quantifying and valuating, which need to be resolved. The one of important components which affects human health and the value of an area, and have some shortcomings are noise costs. Improvement of this component will lead to more accurate valuation of economic efficiency of roads.

Trend road safety measures : international course on transportation and road engineering in developing countries. Two-year postgraduate Diploma and M.Sc. programme.

NARCIS (Netherlands)

1991-01-01

This course focuses mainly on traffic and transport in developing countries, and deals primarily with matters of infrastructure. Road safety and road safety problems are closely related to the construction and operation of the road network. (See also C 1341 - C1346).

From iPSC towards cardiac tissue-a road under construction.

Science.gov (United States)

Peischard, Stefan; Piccini, Ilaria; Strutz-Seebohm, Nathalie; Greber, Boris; Seebohm, Guiscard

2017-10-01

The possibility to generate induced pluripotent stem cells (iPSC) opens the way to generate virtually all cell types of our human body. In combination with modern gene editing techniques like CRISPR/CAS, a new set of powerful tools becomes available for life science. Scientific fields like genotype and cell type-specific pharmacology, disease modeling, stem cell biology, and developmental biology have been dramatically fostered and their faces have been changed. However, as golden as the age of iPSC-derived cells and their manipulation has started, the shine begins to tarnish. Researchers face more and more practical problems intrinsic to the system. These problems are related to the specific culturing conditions which are not yet sufficient to mimic the natural environment of native stem cells differentiating towards adult cells. However, researchers work hard to uncover these factors. Here, we review a common standard approach to generate iPSCs and transduce these to iPSC cardiomyocytes. Further, we review recent achievements and discuss their current limitations and future perspectives. We are on track, but the road is still under construction.

Grass composition and rangeland condition of the major grazing ...

African Journals Online (AJOL)

One area represented lightly grazed government ranches or parks which were used as benchmarks, another area represented the seasonal grazing areas with an intermediate grazing pressure and the remaining were the heavily grazed roadsides, lakeshores and other communal grazing lands. The range condition ...

Stress-in-motion (SIM) - tyre/road interface contact stresses

CSIR Research Space (South Africa)

De Beer, Morris

2012-06-01

Full Text Available Tyre or road interface stresses are those induced by vehicular traffic running on roads, and are the primary cause of surfacing problems. The cost of asphalt layers is often the most significant in road construction and maintenance work...

Modelling nitrous oxide emissions from grazed grassland systems

International Nuclear Information System (INIS)

Wang Junye; Cardenas, Laura M.; Misselbrook, Tom H.; Cuttle, Steve; Thorman, Rachel E.; Li Changsheng

2012-01-01

Grazed grassland systems are an important component of the global carbon cycle and also influence global climate change through their emissions of nitrous oxide and methane. However, there are huge uncertainties and challenges in the development and parameterisation of process-based models for grazed grassland systems because of the wide diversity of vegetation and impacts of grazing animals. A process-based biogeochemistry model, DeNitrification-DeComposition (DNDC), has been modified to describe N 2 O emissions for the UK from regional conditions. This paper reports a new development of UK-DNDC in which the animal grazing practices were modified to track their contributions to the soil nitrogen (N) biogeochemistry. The new version of UK-DNDC was tested against datasets of N 2 O fluxes measured at three contrasting field sites. The results showed that the responses of the model to changes in grazing parameters were generally in agreement with observations, showing that N 2 O emissions increased as the grazing intensity increased. - Highlights: ► Parameterisation of grazing system using grazing intensity. ► Modification of UK D NDC for the UK soil and weather conditions. ► Validation of the UK D NDC against measured data of N 2 O emissions in three UK sites. ► Estimating influence of animal grazing practises on N 2 O emissions. - Grazing system was parameterised using grazing intensity and UK-DNDC model was modified and validated against measured data of N 2 O emissions in three UK sites.

Synergistic Interactions within a Multispecies Biofilm Enhance Individual Species Protection against Grazing by a Pelagic Protozoan

Directory of Open Access Journals (Sweden)

Prem K. Raghupathi

2018-01-01

Full Text Available Biofilm formation has been shown to confer protection against grazing, but little information is available on the effect of grazing on biofilm formation and protection in multispecies consortia. With most biofilms in nature being composed of multiple bacterial species, the interactions and dynamics of a multispecies bacterial biofilm subject to grazing by a pelagic protozoan predator were investigated. To this end, a mono and multispecies biofilms of four bacterial soil isolates, namely Xanthomonas retroflexus, Stenotrophomonas rhizophila, Microbacterium oxydans and Paenibacillus amylolyticus, were constructed and subjected to grazing by the ciliate Tetrahymena pyriformis. In monocultures, grazing strongly reduced planktonic cell numbers in P. amylolyticus and S. rhizophila and also X. retroflexus. At the same time, cell numbers in the underlying biofilms increased in S. rhizophila and X. retroflexus, but not in P. amylolyticus. This may be due to the fact that while grazing enhanced biofilm formation in the former two species, no biofilm was formed by P. amylolyticus in monoculture, either with or without grazing. In four-species biofilms, biofilm formation was higher than in the best monoculture, a strong biodiversity effect that was even more pronounced in the presence of grazing. While cell numbers of X. retroflexus, S. rhizophila, and P. amylolyticus in the planktonic fraction were greatly reduced in the presence of grazers, cell numbers of all three species strongly increased in the biofilm. Our results show that synergistic interactions between the four-species were important to induce biofilm formation, and suggest that bacterial members that produce more biofilm when exposed to the grazer not only protect themselves but also supported other members which are sensitive to grazing, thereby providing a “shared grazing protection” within the four-species biofilm model. Hence, complex interactions shape the dynamics of the biofilm and

Lucerne varieties for continuous grazing

DEFF Research Database (Denmark)

Søegaard, Karen

2012-01-01

severe grazing with heifers in two cutting/grazing managements. Two new varieties, Verbena and Camporegio, and an older variety Luzelle were established in 2009 in pure stands and in two different mixtures with perennial ryegrass (Lolium perenne). Camporegio had the lowest yield, the lowest competitive...... strength, the lowest plant density in spring, and the density was most reduced during grazing. The results could not confirm significant differences between the new and the older varieties. The results for Luzelle were generally between Verbena and Camporegio. The varieties did not differ in herbage...

Productivity of grasslands under continuous and rotational grazing

NARCIS (Netherlands)

Lantinga, E.A.

1985-01-01

In the Netherlands, rotational grazing, with grazing periods of 2 to 5 days, is the most common grazing system at present. In contrast with other countries of North-western Europe, the continuous grazing system is used here only to a limited extent. However, the results of numerous

Effects of new roads on environmental resource use in the Central Himalaya

DEFF Research Database (Denmark)

Charlery, Lindy Callen; Nielsen, Martin Reinhardt; Meilby, Henrik

2016-01-01

Construction of roads into remote rural areas can improve livelihoods by reducing transportation costs, but may also have negative environmental impacts, such as increased deforestation. However, evidence of the effect of rural roads on household environmental income and reliance, as well as local...... income and reliance, and how are they affected by road establishment; and (iii) what are the short-term impacts of the construction of a rural road on local forest conservation? Following the Poverty Environment Network (PEN) methodology, income data from 176 randomly-sampled households were collected...... in 2006 from two similar Himalayan villages, Lete and Lulang, and again in 2012 after a new road was constructed in 2008 in Lete. Forest strata data were collected in Lete through permanent sample plots (n = 59) measured in 2005 and 2010 and used to estimate stock change (before and after road...

Effects of grazing strategy on limiting nitrate leaching in grazed grass-clover pastures on coarse sandy soil

DEFF Research Database (Denmark)

Hansen, Elly Møller; Eriksen, Jørgen; Søegaard, Karen

2012-01-01

-term mean. The experiment was initiated in a 4-yr-old grass-clover sward in south Denmark. Three treatments were as follows grazing only (G), spring cut followed by grazing (CG) and both spring and autumn cuts with summer grazing (CGC). Nitrate leaching was calculated by extracting water isolates from 80 cm......Urinations of ruminants on grazed pastures increase the risk of nitrate leaching. The study investigated the effect of reducing the length of the grazing season on nitrate leaching from a coarse sandy, irrigated soil during 2006–2007 and 2007–2008. In both years, precipitation was above the long...... depth using ceramic suction cups. Because of considerable variation in measured nitrate concentrations, the 32 installed suction cups per treatment were insufficient to reveal differences between treatments. However, weighted nitrate leaching estimations for G, CG and CGC showed estimated mean nitrate N...

Geo-Hazards and Mountain Road Development in Nepal: Understanding the Science-Policy-Governance Interface

Science.gov (United States)

Dugar, Sumit; Dahal, Vaskar

2015-04-01

The foothills of Nepalese Himalayas located in the neotectonic mountain environment are among some of the most unstable and geomorphologically dynamic landscapes in the world. Young fold mountains in this region are characterized by complex tectonics that influence the occurrence of earthquakes, while climatic processes such as intense orographic rainfall often dictate the occurrence of floods and landslides. Development of linear infrastructures, such as roads, in mountainous terrain characterized by high relief and orogeny is considerably challenging where the complexity of landscape in steep and irregular topography, difficult ground conditions and weak geology, presents engineers and planners with numerous difficulties to construct and maintain mountain roads. Whilst application of engineering geology, geomorphic interpretation of terrain in terms of physiography and hydrology, and identification of geo-hazards along the road corridor is critical for long term operation of mountain roads, low-cost arterial roads in the Himalayan foothills generally fail to incorporate standard road slope engineering structures. This research provides unique insights on policy and governance issues in developing mountainous countries such as Nepal, where achieving a sound balance between sustainability and affordability is a major challenge for road construction. Road development in Nepal is a complex issue where socio-economic and political factors influence the budget allocation for road construction in rural hilly areas. Moreover, most mountain roads are constructed without any geological or geo-technical site investigations due to rampant corruption and lack of adequate engineering supervision. Despite having good examples of rural road construction practices such as the Dharan-Dhankuta Road in Eastern Nepal where comprehensive terrain-evaluation methods and geo-technical surveys led to an improved understanding of road construction, learnings from this project have not

Modeling an impact of road geometric design on vehicle energy consumption

Science.gov (United States)

Luin, Blaž; Petelin, Stojan; Al-Mansour, Fouad

2017-11-01

Some roads connect traffic origins and destinations directly, some use winding, indirect routes. Indirect connections result in longer distances driven and increased fuel consumption. A similar effect is observed on congested roads and mountain roads with many changes in altitude. Therefore a framework to assess road networks based on energy consumption is proposed. It has been shown that road geometry has significant impact on overall traffic energy consumption and emissions. The methodology presented in the paper analyzes impact of traffic volume, shares of vehicle classes, road network configuration on the energy used by the vehicles. It can be used to optimize energy consumption with efficient traffic management and to choose optimum new road in the design phase. This is especially important as the energy consumed by the vehicles shortly after construction supersedes the energy spent for the road construction.

Competitiveness in Road Transport

DEFF Research Database (Denmark)

Borgström, Benedikte; Gammelgaard, Britta; Bruun, Poul

Road transport is an important sector, connecting time and space of production and consumption. Its market conditions has changed. The EU single market implementation has increased price pressure due to supply of low cost road freight transport from counties with lower cost structures. Changes...... in the market also encourage strategic development of some road hauliers into providers of unique services. Such road haulier strategic development contributes to efficiency and effectiveness in basically all business sectors of EU. Little research is available of such strategic and operational management....... In this paper we will explore that knowledge gap and analyze what value proposition(s) and capabilities can transform potential cost disadvantages of acting in a market that includes both high- and low-cost-country actors? And in conceptual terminology, how are capabilities deployed and developed to construct...

Challenges of raising road maintenance funds in developing countries: An analysis of road tolling in Zimbabwe

Directory of Open Access Journals (Sweden)

T. C. Mbara

2010-11-01

Full Text Available The condition of Zimbabwe's roads has been declining due to insufficient maintenance and rehabilitation. Year on year, budget allocations have compared unfavourably with funding considered adequate to maintain highway networks and conduct modest construction work. Road infrastructure shortcomings have manifested themselves in the form of high vehicle operating costs and rampant potholes, leading to a decline in road safety and a deterioration of service levels for those who use roads to deliver goods or connect to international markets. In order to try and stop this vicious cycle of decline, the Government of Zimbabwe, on 8 August 2009, introduced a new policy of road-user charges, which involved the setting-up of 22 toll gates on the trunk road network. The overall objective was to raise revenue in order to close the funding gap, blamed for declining road quality. Although alternative methods of financing road maintenance have been debated for years, a generally accepted understanding is that road users should pay costs for road provisioning. This paper assesses the implementation of a road tolling system in Zimbabwe and describes matters relating to, inter alia, implementation strategy, initial performance outcomes and sustainability.

Grazing Affects Exosomal Circulating MicroRNAs in Cattle

Science.gov (United States)

Muroya, Susumu; Ogasawara, Hideki; Hojito, Masayuki

2015-01-01

Circulating microRNAs (c-miRNAs) are associated with physiological adaptation to acute and chronic aerobic exercise in humans. To investigate the potential effect of grazing movement on miRNA circulation in cattle, here we profiled miRNA expression in centrifugally prepared exosomes from the plasma of both grazing and housed Japanese Shorthorn cattle. Microarray analysis of the c-miRNAs resulted in detection of a total of 231 bovine exosomal miRNAs in the plasma, with a constant expression level of let-7g across the duration and cattle groups. Expression of muscle-specific miRNAs such as miR-1, miR-133a, miR-206, miR-208a/b, and miR-499 were undetectable, suggesting the mildness of grazing movement as exercise. According to validation by quantitative RT-PCR, the circulating miR-150 level in the grazing cattle normalized by the endogenous let-7g level was down-regulated after 2 and 4 months of grazing (P cattle equalized when the grazing cattle were returned to a housed situation. Likewise, the levels of miR-19b, miR-148a, miR-221, miR-223, miR-320a, miR-361, and miR-486 were temporarily lowered in the cattle at 1 and/or 2 month of grazing compared to those of the housed cattle (P cattle at 2 months of grazing (P = 0.044). The elevation of miR-451 level in the plasma was coincident with that in the biceps femoris muscle of the grazing cattle (P = 0.008), which suggests the secretion or intake of miR-451 between skeletal muscle cells and circulation during grazing. These results revealed that exosomal c-miRNAs in cattle were affected by grazing, suggesting their usefulness as molecular grazing markers and functions in physiological adaptation of grazing cattle associated with endocytosis, focal adhesion, axon guidance, and a variety of intracellular signaling, as predicted by bioinformatic analysis. PMID:26308447

Cultural Resource Investigations for a Multipurpose Haul Road on the Idaho National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Brenda R. Pace; Cameron Brizzee; Hollie Gilbert; Clayton Marler; Julie Braun Williams

2010-08-01

The U. S. Department of Energy, Idaho Operations Office is considering options for construction of a multipurpose haul road to transport materials and wastes between the Materials and Fuels Complex (MFC) and other Idaho National Laboratory (INL) Site facilities. The proposed road will be closed to the public and designed for limited year-round use. Two primary options are under consideration: a new route south of the existing T-25 power line road and an upgrade to road T-24. In the Spring of 2010, archaeological field surveys and initial coordination and field reconnaissance with representatives from the Shoshone-Bannock Tribes were completed to identify any resources that may be adversely affected by the proposed road construction and to develop recommendations to protect any listed or eligible for listing on the National Register of Historic Places. The investigations showed that 24 archaeological resources and one historic marker are located in the area of potential effects for road construction and operation south of the T-25 powerline road and 27archaeological resources are located in the area of potential effects for road construction and operation along road T-24. Generalized tribal concerns regarding protection of natural resources were also documented in both road corridors. This report outlines recommendations for additional investigations and protective measures that can be implemented to minimize adverse impacts to the identified resources.

Comparisons of sediment losses from a newly constructed cross-country natural gas pipeline and an existing in-road pipeline

Science.gov (United States)

Pamela J. Edwards; Bridget M. Harrison; Daniel J. Holz; Karl W.J. Williard; Jon E. Schoonover

2014-01-01

Sediment loads were measured for about one year from natural gas pipelines in two studies in north central West Virginia. One study involved a 1-year-old pipeline buried within the bed of a 25-year-old skid road, and the other involved a newly constructed cross-country pipeline. Both pipelines were the same diameter and were installed using similar trenching and...

Livestock grazing, wildlife habitat, and rangeland values

Science.gov (United States)

Paul R. Krausman; David E. Naugle; Michael R. Frisina; Rick Northrup; Vernon C. Bleich; William M. Block; Mark C. Wallace; Jeffrey D. Wright

2009-01-01

Livestock managers make and implement grazing management decisions to achieve a variety of objectives including livestock production, sustainable grazing, and wildlife habitat enhancement. Assessed values of grazing lands and ranches are often based on aesthetics and wildlife habitat or recreational values, which can exceed agricultural values, thus providing...

Performance-based contracts for road projects comparative analysis of different types

CERN Document Server

Gajurel, Ashish

2014-01-01

This book focuses on the aspects of contracting contracts, basically related to road construction and management contracts. The book presents an analytical study of Performance-Based Road Management and Maintenance (PMMR), Funktionsbauvertrag (FBV) (Function-Based Construction Contract) and Public Private Partnerships (PPP). A separate chapter is also included about the comparative study of these contract types. The book provides useful material for university libraries, construction companies and government departments of construction.

In–Service Road Safety Audits

Directory of Open Access Journals (Sweden)

A. Mendoza–Díaz

2009-04-01

Full Text Available A road safety audit is a formal analysis that seeks to guarantee that an existing or future road fulfills optimal safety criteria, conducted by a team of experts who se members are independent of the road project. It can be carried out in one, several or all of the stages of the project (planning, design, construction, before opening the road to traffic, and operation. The development and implementation of a road safety audit process is one of the strategies that have been applied in Mexico in recent years to reduce road accidents and their associated consequences. The objective of this work is to present the procedures that have been developed and applied in Mexico, as well as the benefits and problems that have been encountered. The application of those procedures to a specific case is also shown. Emphasis is made in the audit of high ways in the operation stage, which is the type that greater application and development has had in Mexico.

Introduction to special issue on hydrologic and geomorphic effects of forest roads

Science.gov (United States)

Charles H. Luce; Beverley C. Wemple

2001-01-01

Roads have been a part of human landscapes for more than 40 centuries. During the 20th century, technological advances have increased our ability to construct new roads at unprecedented rates and into steeper terrain. In the last half of that century, an extensive network of roads has been constructed in forests and other wildlands to facilitate use and management of...

A good road lies easy on the land: Water harvesting from low-standard rural roads

OpenAIRE

Zeedyk, B.

2006-01-01

Metadata only record This book addresses the construction and maintenance of unpaved rural roads including strategies, techniques and practices for dealing with problems frequently encountered by landowners, land managers and maintenance personnel. Running water is the primary force affecting road condition and generating the need for maintenance. Economical maintenance means dealing effectively with water, but not just surface runoff. Standing water, seeping water, rain, snow, ice, frost ...

Grazing function g and collimation angular acceptance

Directory of Open Access Journals (Sweden)

Stephen G. Peggs

2009-11-01

Full Text Available The grazing function g is introduced—a synchrobetatron optical quantity that is analogous (and closely connected to the Twiss and dispersion functions β, α, η, and η^{′}. It parametrizes the rate of change of total angle with respect to synchrotron amplitude for grazing particles, which just touch the surface of an aperture when their synchrotron and betatron oscillations are simultaneously (in time at their extreme displacements. The grazing function can be important at collimators with limited acceptance angles. For example, it is important in both modes of crystal collimation operation—in channeling and in volume reflection. The grazing function is independent of the collimator type—crystal or amorphous—but can depend strongly on its azimuthal location. The rigorous synchrobetatron condition g=0 is solved, by invoking the close connection between the grazing function and the slope of the normalized dispersion. Propagation of the grazing function is described, through drifts, dipoles, and quadrupoles. Analytic expressions are developed for g in perfectly matched periodic FODO cells, and in the presence of β or η error waves. These analytic approximations are shown to be, in general, in good agreement with realistic numerical examples. The grazing function is shown to scale linearly with FODO cell bend angle, but to be independent of FODO cell length. The ideal value is g=0 at the collimator, but finite nonzero values are acceptable. Practically achievable grazing functions are described and evaluated, for both amorphous and crystal primary collimators, at RHIC, the SPS (UA9, the Tevatron (T-980, and the LHC.

Road Infrastructure and Road User’s Satisfactions: A Case Study of Motorway Route 7, Thailand

Directory of Open Access Journals (Sweden)

Suanmali Suthathip

2014-01-01

Full Text Available The development of tourism in Thailand relies on the development of appropriate infrastructure. Road access is the key infrastructure issue for tourist destinations throughout Thailand. Each year Thailand has welcomed over 15 million travelers, accounted approximately 7% of GDP. To support tourist activities, variety types of transportation modes have designed. However, road transportation is one of the most effective modes that connect most places together. Beside high-standard vehicles, road is another mechanism that derive comfort and safety of travelling. For this reason, Motorway networks were initiated and constructed to support high speed traffic with high safety and standard. Motorway route 7 is one of major motorway networks that lies between major cities and tourist landmarks. To raise the road standard could be the key to support tourist industry and economic growth. The road developments may not be precise and accurate without knowing the needs from road users’. Therefore, a questionnaire is developed and distributed to 890 randomly selected road users along Motorway route 7. Factor analysis and t-test are employed to analyze the factors affecting road users’ satisfaction and to compare the satisfaction level between both inbound and outbound travelers.

On application of stone filled subgrade construction technique in road construction%填石路基施工技术在公路工程中的应用

Institute of Scientific and Technical Information of China (English)

王宁

2017-01-01

介绍了填石路基的施工技术与质量控制要点,并以某公路工程为例,从基底施工、路基清理、边坡码砌、摊铺填料、路基平整等方面,阐述了填石路基的施工技术,提高了路基的性能.%The paper introduces the construction technique and quality control points for the stone filled subgrade,take a road project as an example,expounds the construction technique of the filling stone roadbed from the subgrade construction,subgrade cleaning,slope stone stocking,pavement and filling,and subgrade smoothness,so as to improve the performance of the subgrade.

Ecological Effects of Grazing in the Northern Tianshan Mountains

Directory of Open Access Journals (Sweden)

Xiaotao Huang

2017-11-01

Full Text Available Identifying the effects of grazing is critical for the conservation, protection and sustainable use of arid grassland ecosystems. However, research regarding the ecological effects of grazing along mountainous elevation gradients is limited in arid areas, particularly at the regional scale. Using the Biome-BGC grazing model, we explored the effects of grazing on grassland net primary productivity (NPP, evapotranspiration (ET and water use efficiency (WUE from 1979 to 2012 along an elevation gradient in the northern Tianshan Mountains. The NPP, ET and WUE values were generally lower under the grazing scenario than under the ungrazed scenario; the differences between the grazing and ungrazed scenarios showed increasing trends over time; and distinct spatial heterogeneity in these differences was observed. Distinct decreases in NPP and WUE under the grazing scenario mainly occurred in regions with high livestock consumption. The decrease in ET was greater in mountainous areas with high grazing intensity due to decreased transpiration and increased surface runoff. This study contributes to a better understanding of the ecological effects of grazing along an elevation gradient in the northern Tianshan Mountains and provides data to support the scientific management of grassland ecosystems.

Remembering Tomorrow: Wagon Roads, Identity and the Decolonization of a First Nations Landscape

OpenAIRE

Gibson, Erin L.S.

2016-01-01

Roads embody the experiences of those who construct, use and maintain them through time. Using a biographical approach I explore how memory and identity are entangled in the material remains of a wagon road in southwestern British Columbia, Canada. First constructed by the Royal Engineers in 1859 to enable miners to reach the Fraser River goldfields, the importance of this road transcends its colonial origins. Entwined in different webs of meaning, the material remains of the wagon road conti...

Road Impact on Deforestation and Jaguar Habitat Loss in the Mayan Forest

DEFF Research Database (Denmark)

Conde, Dalia Amor

2008-01-01

The construction of roads, either as an economic tool or as necessity for the implementation of other infrastructure projects is increasing in the tropical forest worldwide. However, roads are one of the main deforestation drivers in the tropics. In this study we analyzed the impact of road...... and important role in high developed areas. In the short term, the impact of a road in a low developed area is lower than in a road in a high developed area, which could be the result of the lag effect between road construction and forest colonization. This is consistent since roads resulted to be a significant...... investments on both deforestation and jaguar habitat loss, in the Mayan Forest. As well we used these results to forecast the impact of two road investments planned in the region. Our results show that roads are the single deforestation driver in low developed areas, whether many other drivers play...

The grazing pattern of Muturu cattle under range system | Nweze ...

African Journals Online (AJOL)

Eighty Muturu cattle were grazed on rangeland, twice daily for two years to determine their grazing pattern. Twenty bulls and cows each between two to four years and forty calves between one to three months were used. The field grazing time (FGT), active grazing time (GT) and grazing travel time (GTT) were monitored.

Ecology of grazing lawns in Africa

CSIR Research Space (South Africa)

Hempson, GP

2014-09-01

Full Text Available otherwise outcompete lawn species for light. Regular grazing that prevents shading and maintains sward quality is thus the cornerstone of grazing lawn dynamics. The strong interplay between abiotic conditions and disturbance factors, which are central...

Carbon budgets for an irrigated intensively grazed dairy pasture and an unirrigated winter-grazed pasture

Science.gov (United States)

Hunt, John E.; Laubach, Johannes; Barthel, Matti; Fraser, Anitra; Phillips, Rebecca L.

2016-05-01

Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. Here, we determined the NECB over one year for an irrigated, fertilised and rotationally grazed dairy pasture and a neighbouring unirrigated, unfertilised, winter-grazed pasture. Primary terms in the NECB calculation were: net ecosystem production (NEP), biomass carbon removed by grazing cows and carbon (C) input from their excreta. Annual NEP was measured using the eddy-covariance method. Carbon removal was estimated with plate-meter measurements calibrated against biomass collections, pre- and post-grazing. Excreta deposition was calculated from animal feed intake. The intensively managed pasture gained C (NECB = 103 ± 42 g C m-2 yr-1) but would have been subject to a non-significant C loss if cattle excreta had not been returned to the pasture. The unirrigated pasture was C-neutral (NECB = -13 ± 23 g C m-2 yr-1). While annual GPP of the former was almost twice that of the latter (2679 vs. 1372 g C m-2 yr-1), ecosystem respiration differed by only 68 % between the two pastures (2271 vs. 1352 g C m-2 yr-1). The ratio of GPP to the total annual water input of the irrigated pasture was 37 % greater than that of the unirrigated pasture, i.e. the former used the water input more efficiently than the latter to produce biomass. The NECB results agree qualitatively with those from many other eddy-covariance studies of grazed grasslands, but they seem to be at odds with long-term carbon-stock studies of other New Zealand pastures.

Fly ash stabilisation of gravel roads; Flygaska som foerstaerkningslager i grusvaeg

Energy Technology Data Exchange (ETDEWEB)

Macsik, Josef

2006-01-15

Majority of the existing gravel roads have low bearing capacity during spring and autumn, due to thaw and/or rain. Low bearing capacity leads often to bad road conditions. This situation results in higher costs for the lumber industry and the public. Management of gravel roads all the year around would traditionally require excavation of frost susceptible soils and replacement with natural materials. Fly ash (from bio fuels) has good technical properties as bearing layer in road constructions. Fly ash stabilised gravel roads have better function and longer life span with less maintenance than traditional gravel roads. The aim of this project is to show how fly ash stabilisation of gravel roads can increase bearing capacity and what its environmental impact is. The overall aim is to make it easier for entrepreneurs and consulting companies to use fly ash during gravel road renovation and/or constructing new gravel roads. This report targets fly ash producers and road constructors as well as environmental agencies. Two different pilot tests were investigated in this study, Norberg with fly ash from Stora Enso Fors AB, and Boerje (Uppsala) with fly ash from Vattenfall Uppsala AB. Both road sections with related reference section were investigated during a two year period. Only fly ash was used in the bearing layer at Norberg and fly ash gravel was used at Boerje. Bearing capacity was investigated twice, for both locations, November 2003 one month after the road renovation and during thawing, April 2004. Water samples from lysimeters, ground water and surface water were only collected and analysed from Norberg. Experience from the fly ash stabilised road sections show that curing and traffic load can with time compensate for less compaction. The same is noticed at Boerje, although deflection measurements show that there are small differences. Stabilisation of gravel roads increases the roads bearing capacity. Two years after stabilisation 90 timber loads were

Soil Stabilization with Lime for the Construction of Forest Roads

Directory of Open Access Journals (Sweden)

Reginaldo Sérgio Pereira

2018-02-01

Full Text Available ABSTRACT The mechanical performance of soil stabilization using lime to improve forest roads was assessed. This study was conducted with lateritic soil (LVAd30 using lime content of 2% in the municipality of Niquelândia, Goiás state, Brazil. Geotechnical tests of soil characterization, compaction, and mechanical strength were performed applying different compaction efforts and curing periods. The results showed that lime content significantly changed the mechanical performance of natural soil, increasing its mechanical strength and load-carrying capacity. Compaction effort and curing time provided different responses in the unconfined compressive strength (UCS and California Bearing Ratio (CBR tests. The best UCS value (786.59 kPa for the soil-lime mixture was achieved with modified compaction effort and curing time of 28 days. In the CBR test, soil-lime mixtures compacted at intermediate and modified efforts and cured for 28 days were considered for application as subbase material of flexible road pavements, being a promising alternative for use in layers of forest roads.

36 CFR 212.10 - Maximum economy National Forest System roads.

Science.gov (United States)

2010-07-01

... Forest System roads. 212.10 Section 212.10 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT... economy National Forest System roads. The Chief may acquire, construct, reconstruct, improve, and maintain National Forest System roads within and near the National Forests and other lands administered by the...

Construction and Demolition Waste

DEFF Research Database (Denmark)

Christensen, Thomas Højlund; Andersen, L.

2011-01-01

Construction and demolition waste (C&D waste) is the waste generated during the building, repair, remodeling or removal of constructions. The constructions can be roads, residential housing and nonresidential buildings. C&D waste has traditionally been considered without any environmental problems...... should be managed accordingly. Another reason is that it has been documented that a large fraction of C&D waste (about 90 %) can be easily recycled and thus can conserve landfill capacity. C&D waste may conveniently be divided into three subcategories: Buildings, roads and excavations. This chapter...

Herbage intake by grazing dairy cows

NARCIS (Netherlands)

Meijs, J.A.C.

1981-01-01

An extensive review of the literature is given of
- nine possible methods for estimating herbage intake by grazing ruminants, with special attention to the sward-cutting and indirect animal methods
- the factors determining the herbage intake by grazing ruminants.

The

An instrument for the measurement of road surface reflection properties

DEFF Research Database (Denmark)

Corell, Dennis Dan; Sørensen, K.

2017-01-01

surfaces in use have changed - for instance to road surface types with less noise from wheel passages. Because of this, a co-operation between the road administrations of the Nordic countries (abbreviated NMF) decided to construct a portable instrument to be used on selections of traffic roads within......Road surface reflection data in the form of standard r-tables serve as input for design calculations of road lighting installations on traffic roads. However, in several countries the use of the standard r-tables has not been verified by measurement in a long period of time, while the types of road...

Physical soil properties and slope treatments effects on hydraulic excavator productivity for forest road construction.

Science.gov (United States)

Parsakho, Aidin; Hosseini, Seyed Ataollah; Jalilvand, Hamid; Lotfalian, Majid

2008-06-01

Effects of moisture, porosity and soil bulk density properties, grubbing time and terrain side slopes on pc 220 komatsu hydraulic excavator productivity were investigated in Miana forests road construction project which located in the northern forest of Iran. Soil moisture and porosity determined by samples were taken from undisturbed soil. The elements of daily works were measured with a digital stop watch and video camera in 14 observations (days). The road length and cross section profiles after each 20 m were selected to estimate earthworks volume. Results showed that the mean production rates for the pc 220 komatsu excavators were 60.13 m3 h(-1) and earthwork 14.76 m h(-1) when the mean depth of excavation or cutting was 4.27 m3 m(-1), respectively. There was no significant effects (p = 0.5288) from the slope classes' treatments on productivity, whereas grubbing time, soil moisture, bulk density and porosity had significantly affected on excavator earthworks volume (p < 0.0001). Clear difference was showed between the earthwork length by slope classes (p = 0.0060). Grubbing time (p = 0.2180), soil moisture (p = 0.1622), bulk density (p = 0.2490) and porosity (p = 0.2159) had no significant effect on the excavator earthworks length.

Concrete debris assessment for road construction activities : final report.

Science.gov (United States)

2016-08-01

Two distinct but related issues of importance to FDOT were investigated: (1) the possible impact of : recycled concrete aggregate (RCA) used as road base on the subsurface environment and (2) the : management of concrete grinding residuals (CGR) resu...

How Does “Hunger” Level Impact Grazing Behavior?

Science.gov (United States)

Grazing behavior can be influenced through feeding and grazing management decisions. Research at our USDA-ARS lab showed that ruminal fill, or how ‘hungry’ the cow is, can affect grazing behavior. Cows that had less ruminal fill took a bigger bite that was shallow and wide, compared to a ‘full’ cow ...

Annual methane budgets of sheep grazing systems were regulated by grazing intensities in the temperate continental steppe: A two-year case study

Science.gov (United States)

Ma, Lei; Zhong, Mengying; Zhu, Yuhao; Yang, Helong; Johnson, Douglas A.; Rong, Yuping

2018-02-01

Methane (CH4) emission from animal husbandry accounts for a large percentage of anthropogenic contributions to CH4 emissions. Fully understanding of grazing management effects on the CH4 budget is essential for mitigating CH4 emissions in the temperate grazing steppe systems. Annual CH4 budgets for the sheep grazed steppes at various grazing intensities, un-grazing (UG, 0 sheep ha-1year-1), defer grazing (DG, 1.0 sheep ha-1 year-1), moderate grazing (MG, 1.43 sheep ha-1year-1), and heavy grazing (HG, 2.43 sheep ha-1year-1) were assessed across 2012-2014 in the agro-pastoral region of northern China. Annual soil CH4 uptake averaged across 2012-2014 were 1.1 ± 0.1, 2.4 ± 0.2, 2.2 ± 0.2, and 1.3 ± 0.1 kg CH4-C ha-1 for UG, DG (only 2013-2014), MG and HG sites. Non-growing season CH4 uptake comprised 50.0 ± 4.3% of annual CH4 uptake in 2012-2013 and 37.7 ± 2.0% in 2013-2014. DG and MG significantly promoted annual soil CH4 uptake (P 0.05). Bell-shaped relationship was presented between stocking rates and soil CH4 uptake (r2 = 0.59, P budgets for the grazed grasslands were -1.1 ± 0.1, 5.7 ± 0.6, 11.5 ± 1.5 and 15.5 ± 1.3 kg CH4-C ha-1 year-1 in UG, DG (only 2013-2014), MG and HG across 2012-2014. Soil CH4 uptake could offset 29.7 ± 5.6, 15.9 ± 4.3 and 6.8 ± 1.0% of total annual CH4 emissions from sheep, sheepfold and faeces in DG, MG, and HG. All grazed steppes are sources for atmospheric CH4 and the magnitude is regulated by grazing intensities. Sheep CH4 emissions for 1-g liveweight gain were 0.21, 0.32 and 0.37 g CH4-C in DG, MG and HG, respectively. DG is the recommended grazing management in this region to achieve greater herbage mass, higher sheep performance and lower CH4 emissions simultaneously.

Roads, interrupted dispersal, and genetic diversity in timber rattlesnakes.

Science.gov (United States)

Clark, Rulon W; Brown, William S; Stechert, Randy; Zamudio, Kelly R

2010-08-01

Anthropogenic habitat modification often creates barriers to animal movement, transforming formerly contiguous habitat into a patchwork of habitat islands with low connectivity. Roadways are a feature of most landscapes that can act as barriers or filters to migration among local populations. Even small and recently constructed roads can have a significant impact on population genetic structure of some species, but not others. We developed a research approach that combines fine-scale molecular genetics with behavioral and ecological data to understand the impacts of roads on population structure and connectivity. We used microsatellite markers to characterize genetic variation within and among populations of timber rattlesnakes (Crotalus horridus) occupying communal hibernacula (dens) in regions bisected by roadways. We examined the impact of roads on seasonal migration, genetic diversity, and gene flow among populations. Snakes in hibernacula isolated by roads had significantly lower genetic diversity and higher genetic differentiation than snakes in hibernacula in contiguous habitat. Genetic-assignment analyses revealed that interruption to seasonal migration was the mechanism underlying these patterns. Our results underscore the sizeable impact of roads on this species, despite their relatively recent construction at our study sites (7 to 10 generations of rattlesnakes), the utility of population genetics for studies of road ecology, and the need for mitigating effects of roads.

Road dust emissions from paved roads measured using different mobile systems.

Science.gov (United States)

Pirjola, Liisa; Johansson, Christer; Kupiainen, Kaarle; Stojiljkovic, Ana; Karlsson, Hans; Hussein, Tareq

2010-12-01

Very few real-world measurements of road dust suspension have been performed to date. This study compares two different techniques (referred to as Sniffer and Emma) to measure road dust emissions. The main differences between the systems are the construction of the inlet, different instruments for recording particulate matter (PM) levels, and different loads on the wheel axes (the weight of Sniffer was much higher than that of Emma). Both systems showed substantial small-scale variations of emission levels along the road, likely depending on-road surface conditions. The variations observed correlated quite well, and the discrepancies are likely a result of variations in dust load on the road surface perpendicular to the driving direction that cause variations in the measurements depending on slightly different paths driven by the two vehicles. Both systems showed a substantial influence on the emission levels depending on the type of tire used. The summer tire showed much lower suspension than the winter tires (one nonstudded and one studded). However, the relative importance of the nonstudded versus studded tire was rather different. For the ratio of studded/nonstudded, Emma shows higher values on all road sections compared with Sniffer. Both techniques showed increased emission levels with increasing vehicle speed. When the speed increased from 50 to 80 km hr(-1), the relative concentrations increased by 30-170% depending on the tire type and dust load. However, for road sections that were very dirty, Sniffer showed a much higher relative increase in the emission level with the nonstudded tire. Sniffer's absolute concentrations were mostly higher than Emma's. Possible reasons for the differences are discussed in the paper. Both systems can be used for studying relative road dust emissions and for designing air quality management strategies.

Livestock Grazing as a Driver of Vernal Pool Ecohydrology

Science.gov (United States)

Michaels, J.; McCarten, N. F.

2017-12-01

Vernal pools are seasonal wetlands that host rare plant communities of high conservation priority. Plant community composition is largely driven by pool hydroperiod. A previous study found that vernal pools grazed by livestock had longer hydroperiods compared with pools excluded from grazing for 10 years, and suggests that livestock grazing can be used to protect plant diversity. It is important to assess whether observed differences are due to the grazing or due to water balance variables including upland discharge into or out of the pools since no a priori measurements were made of the hydrology prior to grazing. To address this question, in 2016 we compared 15 pools that have been grazed continuously and 15 pools that have been fenced off for over 40 years at a site in Sacramento County. We paired pools based on abiotic characteristics (size, shape, slope, soil type) to minimize natural variation. We sampled vegetation and water depth using Solinst level loggers. We found that plant diversity and average hydroperiod was significantly higher in the grazed pools. We are currently measuring groundwater connectivity and upland inputs in order to compare the relative strength of livestock grazing as a driver of hydroperiod to these other drivers.

Long-term leaching from recycled concrete aggregates applied as sub-base material in road construction.

Science.gov (United States)

Engelsen, Christian J; van der Sloot, Hans A; Petkovic, Gordana

2017-06-01

In the present study, the metal leaching from recycled concrete aggregates (RCA) used in road sub-base is presented after >10years of exposure. The released levels of inorganic constituents, the effect of small variation of pH and the use of de-icing salt during winter season were studied. In addition, speciation modelling for the major elements has been provided. The pH varied from 7.5 to 8.5 for the sub-base constructed with RCA whereas the pH of around 8 was obtained for the test section not affected by the traffic and de-icing salts. Despite a small variation in pH, the leachability of Al, Ca and Mg was found to be strongly dependent on pH and fair agreement between the measured and predicted concentrations was obtained. The speciation modelling indicated that gibbsite, calcite and magnesite controlled the solubility of Al, Ca and Mg, respectively, which was in agreement with the expected carbonation products. Due to the larger pH fluctuations in the test sections exposed to the road traffic, increased concentrations were observed for the oxyanions. The same effect was not seen for the trace metal cations Cd, Cu, Ni, Pb and Zn. The distinct pH dependent leaching profile (solubility maximum in the mildly basic pH region) for vanadium could be seen after 10years of exposure. The simplified risk assessment showed that the released quantities did not exceed the chosen acceptance criteria for groundwater and fresh water. The results obtained for the test section not influenced by road dust and de-icing salts, complied with these criteria even without considering any dilution effects caused by the mixing of pore water with groundwater. Copyright © 2017 Elsevier B.V. All rights reserved.

Transitions and coexistence along a grazing gradient in the Eurasian steppe

Science.gov (United States)

Ren, Haiyan; Taube, Friedelm; Zhang, Yingjun; Bai, Yongfei; Hu, Shuijin

2017-04-01

Ecological resilience theory has often been applied to explain species coexistence and range condition assessment of various community states and to explicate the dynamics of ecosystems. Grazing is a primary disturbance that can alter rangeland resilience by causing hard-to-reverse transitions in grasslands. Yet, how grazing affects the coexistence of plant functional group (PFG) and transition remains unclear. We conducted a six-year grazing experiment in a typical steppe of Inner Mongolia, using seven grazing intensities (0, 1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 sheep/ hectare) and two grazing systems (i.e. a continuous annual grazing as in the traditional grazing system, and a mixed grazing system combining grazing and haymaking), to examine grazing effects on plant functional group shifts and species coexistence in the semi-arid grassland system. Our results indicate that the relative richness of dominant bunchgrasses and forbs had a compensatory coexistence at all grazing intensities, and the richness of rhizomatous grasses fluctuated but was persistent. The relative productivity of dominant bunchgrasses and rhizomatous grasses had compensatory interactions with grazing intensity and grazing system. Dominant bunchgrasses and rhizomatous grasses resist grazing effects by using their dominant species functional traits: high specific leaf area and low leaf nitrogen content. Our results suggest that: 1. Stabilizing mechanisms beyond grazing management are more important in determining plant functional group coexistence and ecological resilience. 2. Plant functional group composition is more important in influencing ecosystem functioning than diversity. 3. Ecosystem resilience at a given level is related to the biomass of dominant PFG, which is determined by a balanced shift between dominant species biomass. The relatively even ecosystem resilience along the grazing gradient is attributed to the compensatory interactions of dominant species in their biomass variations

Riparian Meadow Response to Modern Conservation Grazing Management

Science.gov (United States)

Oles, Kristin M.; Weixelman, Dave A.; Lile, David F.; Tate, Kenneth W.; Snell, Laura K.; Roche, Leslie M.

2017-09-01

Riparian meadows occupy a small proportion of the public lands in the western United States but they provide numerous ecosystem services, including the production of high-quality forage for livestock grazing. Modern conservation management strategies (e.g., reductions in livestock stocking rates and adoption of new riparian grazing standards) have been implemented to better balance riparian conservation and livestock production objectives on publicly managed lands. We examined potential relationships between long-term changes in plant community, livestock grazing pressure and environmental conditions at two spatial scales in meadows grazed under conservation management strategies. Changes in plant community were not associated with either livestock stocking rate or precipitation at the grazing allotment (i.e., administrative) scale. Alternatively, both grazing pressure and precipitation had significant, albeit modest, associations with changes in plant community at the meadow (i.e., ecological site) scale. These results suggest that reductions in stocking rate have improved the balance between riparian conservation and livestock production goals. However, associations between elevation, site wetness, precipitation, and changes in plant community suggest that changing climate conditions (e.g., reduced snowpack and changes in timing of snowmelt) could trigger shifts in plant communities, potentially impacting both conservation and agricultural services (e.g., livestock and forage production). Therefore, adaptive, site-specific management strategies are required to meet grazing pressure limits and safeguard ecosystem services within individual meadows, especially under more variable climate conditions.

Tourist Assessment of Croatian Roads

Directory of Open Access Journals (Sweden)

Joso Vurdelja

2012-10-01

Full Text Available As environmentally clean industry and as the most significantworld industry regarding the number of employees and theimpact on the social and economic development of a countTy,tourism represents an extremely important social and economicbranch for Croatia.As a functional unit of the mutually interweaving socialand economic relations, tourism is a complex phenomenonwhose development depends on a number of compatible factorsout of which the transport infrastructure is considered to bethe most obvious and almost the most significant one, i.e. thefirst among the equal. This is primarily true for road traffic infrastructure,since road trai!Sportation of tourists by passengercars, buses and motorcycles accounts for more than 90 percentof the overall tourist journeys in Croatia.The topic of this paper is precisely, among other things, thetourist assessment of the Croatian road network by means ofthe so-called econometric model regarding the contribution ofa certain road route to the overall tourist traffic.Practical implementation of the elaborated problematicshould result in the improvement of road infrastructure eitherby constructing new motonvays and/or roads, or by reconstructionand/or modernisation of the existing traffic routes.

SUNRA - a sustainability rating system framework for National Road Administrations

DEFF Research Database (Denmark)

Sowerby, Chris; Langstraat, James; Harmer, Clare

National Road Administrations (NRAs) across Europe strive to improve the performance of their road networks. This improvement has been underpinned by significant research in the optimisation of road planning, design, construction and maintenance, which has enhanced the understanding of the social......, environmental and economic aspects of managing a road network. Whilst there is common understanding in some aspects of sustainability there is not a common understanding of sustainability as a whole and thus how to benchmark and improve overall performance. The Sustainability: National Road Administrations...

Rehabilitation of a secondary network of forest traffic infrastructure (skid roads - skid trails

Directory of Open Access Journals (Sweden)

Bajrić Muhamed

2015-01-01

Full Text Available Forest transport infrastructure is the key segment of rational forest resource management. One of its constituent and inseparable segments are skid roads and skid trails whose network density significantly exceeds the primary network, i.e. truck roads. Skid road -skid trail network density in high economic forests of FB&H is most often between 40 and 100 m/ha. Simplified way of construction, non-existence of road construction, objects for surface water drainage as well as significant longitudinal inclination (up to 50% in which they are constructed, makes them subject to erosion processes. The lack of rehabilitation measures on skid roads - skid trails causes significant damages in post-exploitation period, and very often to the extent that the ones in the following exploitation round are unusable for skidding. Utilization of skid roads - skid trails damaged by erosion processes for forest operations often represents a significant expense. This paper considers rehabilitation measures efficient from the point of remedying erosion processes, and at the same time, acceptable from the point of financial expenditure for forest operations.

THE CONCEPTUAL FRAMEWORK OF FORMING THE PRODUCT QUALITY CONTROL STRATEGY OF ROAD-BUILDING ENGINEERING ENTERPRISES

Directory of Open Access Journals (Sweden)

Mariia Sadova

2017-11-01

Full Text Available The purpose of the work is the need of the theoretical justification and the development of relevant scientific and methodological approaches to the management of the road production quality of machine-building enterprises; it led to the choice of research topics. Methodology. Taking into account the value of existing methods of quality management of road production engineering companies, currently a particular attention requires improvement of the quality control functions: analysis, evaluation, planning and quality control during the operation of road-building equipment, because existing economic practices and quality management approaches are built on classical principles of ISO 9001, and in the practical application do not solve all of the drawbacks of traditional management models, but only smooth them a little. Therefore, the formation of the quality management strategy for the road production of mechanical engineering is essential to ensure the competitiveness of products and enterprises of the road-building complex in the period of development of market relations in the economy. The results showed that the current market conditions impose strict requirements to all production areas of the society. Especially stringent are requirements for the road construction, because the quality of the construction of the subgrade, covering roads and curbs, grading and soil compaction under different conditions of terrain and driving safety depends on people's lives. This factor determines the exceptional quality requirements for roadbuilding equipment, which must be reliable, functional and able to meet the totality of the design and operational characteristics of the road. Further European integration of Ukraine, deepening of external economic relations with the European countries are responsible for the growing needs of the national economy in the development and expansion of the transport network. However, large-scale road construction and repair

Response of mountain meadows to grazing by recreational pack stock

Science.gov (United States)

Cole, David N.; Van Wagtendonk, Jan W.; McClaran, Mitchel P.; Moore, Peggy E.; McDougald, Neil K.

2004-01-01

Effects of recreational pack stock grazing on mountain meadows in Yosemite National Park were assessed in a 5-year study. Yosemite is a designated wilderness, to be managed such that its natural conditions are preserved. Studies were conducted in 3 characteristic meadow types: shorthair sedge (Carex filifolia Nutt.), Brewer's reed grass (Calamagrostis breweri Thurber), and tufted hairgrass [Deschampsia cespitosa (L.) Beauv.]. Horses and mules grazed experimental plots at intensities of 15 to 69% utilization for 4 seasons. In all 3 meadows, grazing caused decreases in productivity. The mean reduction after 4 years of grazing was 18% in the shorthair sedge meadow, 17% in the Brewer's reed grass meadow, and 22% in the tufted hairgrass meadow. Grazing also caused shifts in basal groundcover (usually a reduction in vegetation cover and increase in bare soil cover), and changes in species composition. Productivity and vegetation cover decreased as percent utilization increased, while bare soil cover increased as utilization increased. Changes in species composition were less predictably related to differences in grazing intensity. Passive management of grazing is insufficient in wilderness areas that are regularly used by groups with recreational stock. Wilderness managers need to monitor meadow conditions and the grazing intensities that occur. Our study suggests that biomass and ground cover are more sensitive indicators of grazing impact than species composition. Managers must make decisions about maximum acceptable levels of grazing impact and then develop guidelines for maximum use levels, based on data such as ours that relates grazing intensity to meadow response.

A review of models relevant to road safety.

Science.gov (United States)

Hughes, B P; Newstead, S; Anund, A; Shu, C C; Falkmer, T

2015-01-01

It is estimated that more than 1.2 million people die worldwide as a result of road traffic crashes and some 50 million are injured per annum. At present some Western countries' road safety strategies and countermeasures claim to have developed into 'Safe Systems' models to address the effects of road related crashes. Well-constructed models encourage effective strategies to improve road safety. This review aimed to identify and summarise concise descriptions, or 'models' of safety. The review covers information from a wide variety of fields and contexts including transport, occupational safety, food industry, education, construction and health. The information from 2620 candidate references were selected and summarised in 121 examples of different types of model and contents. The language of safety models and systems was found to be inconsistent. Each model provided additional information regarding style, purpose, complexity and diversity. In total, seven types of models were identified. The categorisation of models was done on a high level with a variation of details in each group and without a complete, simple and rational description. The models identified in this review are likely to be adaptable to road safety and some of them have previously been used. None of systems theory, safety management systems, the risk management approach, or safety culture was commonly or thoroughly applied to road safety. It is concluded that these approaches have the potential to reduce road trauma. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of grazing on cow mortality in Danish dairy herds

DEFF Research Database (Denmark)

Burow, Elke; Thomsen, Peter Thorup; Sørensen, Jan Tind

2011-01-01

The effect of summer grazing in large Danish dairy herds and certain management characteristics of grazing were studied for their impact on dairy cow mortality. Mortality data (from the Danish Cattle Database) from 391 Danish dairy herds (>100 cows) were combined with information from...... a questionnaire survey of grazing procedures on these herds in 2008. In all, 131 of the herds were identified as summer grazing and 260 as zero-grazing herds. The mortality was affected by an interaction of summer grazing and milking system. The risk of a cow dying was reduced to 46% in a grazing compared...... and pasture was associated with increased cow mortality....

Woodlands Grazing Issues in Mediterranean Basin

Science.gov (United States)

Campos, P.

2009-04-01

In Mediterranean basin, woodlands grazing still continue to be important commercial owners' benefits. These owners manage woodlands vegetations as if they were not at risk of degradation and declining. Frequently, no temporally grazing set-aside is taken into account to avoid overgrazing of annual and perennial vegetations. Although less common, in the northern shore of Mediterranean basin undergrazing might increase the frequency and the number of catastrophic forest fires. This under/over grazing regime occurs in the Mediterranean basin woodlands with contrasted differences on land property rights, local economies and government livestock policy incentives. Spain and Tunisia are examples of these Mediterranean livestock contrasts. Most of Spanish Mediterranean woodlands and livestock herds are large private ownerships and owners could maintain their lands and livestock herds properties on the basis of moderate cash-income compensation against land revaluation and exclusive amenity self-consumption. The later is less tangible benefit and it could include family land legacy, nature enjoyment, country stile of life development, social status and so on. In public woodlands, social and environmental goals -as they are cultural heritage, biodiversity loss mitigation, soil conservation and employment- could maintain market unprofitable woodlands operations. Last three decades Spanish Mediterranean woodlands owners have increased the livestock herds incentivized by government subsidies. As result, grazing rent is pending on the level of European Union and Spanish government livestock subsidies. In this context, Spanish Mediterranean woodlands maintain a high extensive livestock stoking population, which economy could be called fragile and environmentally unsustainable because forest degradation and over/under grazing practices. Tunisian Mediterranean woodlands are state properties and livestock grazing is practice as a free private regimen. Livestock herds are small herd

Grazing disturbance increases transient but decreases persistent soil seed bank.

Science.gov (United States)

Ma, Miaojun; Walck, Jeffrey L; Ma, Zhen; Wang, Lipei; Du, Guozhen

2018-04-30

Very few studies have examined whether the impacts of grazing disturbance on soil seed banks occur directly or indirectly through aboveground vegetation and soil properties. The potential role of the seed bank in alpine wetland restoration is also unknown. We used SEM (structural equation modeling) to explore the direct effect of grazing disturbance on the seed bank and the indirect effect through aboveground vegetation and soil properties. We also studied the role of the seed bank on the restoration potential in wetlands with various grazing intensities: low (fenced, winter grazed only), medium (seasonally grazed), and high (whole-year grazed). For the seed bank, species richness and density per plot showed no difference among grazing intensities for each depth (0-5, 5-10, 10-15 cm) and for the whole depth (0-15 cm) in spring and summer. There was no direct effect of grazing disturbance on seed bank richness and density both in spring and summer, and also no indirect effect on the seed bank through its direct effect on vegetation richness and abundance. Grazing disturbance indirectly increased spring seed bank density but decreased summer seed bank density through its direct effect (negative correlation) on soil moisture and total nitrogen and its indirect effect on vegetation abundance. Species composition of the vegetation changed with grazing regime, but that of the seed bank did not. An increased trend of similarity between the seed bank and aboveground vegetation with increased grazing disturbance was found in the shallow depth and in the whole depth only in spring. Although there was almost no change in seed bank size with grazing intensities, grazing disturbance increased the quantity of transient seeds but decreased persistent seeds. Persistent seeds stored in the soil could play a crucial role in vegetation regeneration and in restoration of degraded wetland ecosystems. The seed bank should be an integral part of alpine wetland restoration programs. �

A review of experiments comparing systems of grazing management ...

African Journals Online (AJOL)

Experiments comparing different systems of grazing management on natural pastures in various parts of the world are reviewed. In experiments in which various rotational systems were tested against continuous grazing, fewer than half revealed pasture improvement relative to continuous grazing. In the majority of ...

Resource Roads demonstration project : final report

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-15

British Columbia's vast network of resource roads are considered to be amongst the most dangerous, high-risk workplaces in the province. Resource roads, also known as industrial roads, forest service roads, or petroleum development roads, present several unique safety challenges as workplaces. They are built for the purpose of access, egress and transport of materials, resources, equipment and people. However, the lack the same diligence of enforcement and a consistent design, construction, maintenance and standard for use as public highways or municipal roads. There are also safety challenges related to public use of resource roads. This report presented a project, called ResourceRoads by WorkSafe BC that focused on the organization and implementation of a management structure that would provide a system of coordination and a process of compliance for the users of the defined road systems. The project was based on information gathered in two forest districts of Prince George and the South Peace Forest Districts. A committee consisting of the actual owner of the road and other users was formed. The report presented a history of British Columbia's resource road system, and discussed resource roads as industrial workplaces and worksites, as well as resource road fatality statistics. The demonstration project was outlined in terms of project leadership; scope; strategic objectives; project purpose; performance objectives; project communication; demonstration areas; and project stages. Project fundamentals and project findings were also presented along with recommendations and responses to the Auditor General report and the Forest Safety Ombudsman report. It was concluded that potential uses of new technologies for resource road vehicles should be reviewed. tabs., figs.

Faster bridge construction using precast substructures : brief.

Science.gov (United States)

2011-07-01

Bridge replacement often requires road closures and detours that frustrate road users. It remains a key goal of Wisconsin DOT to reduce construction-related road use interruptions. This will be a challenge with bridges: Bridge inspections in 2007 ide...

Politics of contemporary "Silk Roads"

Directory of Open Access Journals (Sweden)

Andrey I. Litvinov

2016-01-01

Full Text Available Recently in mass media we can find the idea about a new Silk Road or the concept of "Silk Road Economic Belt" which has been formulated by the Chinese PresidentXi Jinping on September 7,2013, during his official visit to Kazakhstan. This project is not only the creation of a transport, power and trade corridor, and also the project which will promote development of tourism in the region and to strengthening of cultural exchanges of China with the countries of Central Asia, it also includes construction of a network of high-speed fiber-optical networks. The economic strip of the Silk Road will begin in China and pass across the Central and the Southern Asia, part of branches across the territory of the Russian Federation and to leave to Europe. This international investment project assumes creation of a continental transport way. For implementation of overland part of "A great Silk Road is a three railway corridors (northern, central have to be constructed and southern They have form a basis for development of other means of transport, including automobile subsequently. Construction of these three railway corridors acts as the most important and necessary stage of implementation of the project. The government of China declares that creation of an economic belt of the Silk way is a revival of once prospering trade-transport and cultural corridor from Asia to Europe which will promote activization of a friendly exchange between the people of the different countries. Further all this has to connect trade and economic space of Europe and Asia in a whole that has to serve implementation of deeper economic cooperation, between the countries participating in him, to increase in a trade turnover and expansion of scientific and technical exchanges between them.

Conceptual design report, TWRS Privatization Phase I, site development and roads, subproject W-505

International Nuclear Information System (INIS)

Singh, G.

1997-01-01

This document includes Conceptual Design Report (CDR) for the site development, construction of new roads and improvements at existing road intersections, habitat mitigation, roadway lighting, and construction power needed for the construction of two Private Contractor (PC) Facilities. Approximately 50 hectare (124 acres) land parcel, east of the Grout Facility, is planned for the PC facilities

Milk production, grazing behavior and nutritional status of dairy cows grazing two herbage allowances during winter

Directory of Open Access Journals (Sweden)

Miguel Ruiz-Albarran

2016-03-01

Full Text Available Winter grazing provides a useful means for increasing the proportion of grazed herbage in the annual diet of dairy cows. This season is characterized by low herbage growth rate, low herbage allowance, and low herbage intake and hence greater needs for supplements to supply the requirements of lactating dairy cows. The aim of this study was to determine the influence of herbage allowance (HA offered to autumn calving dairy cows grazing winter herbage on milk production, nutritional status, and grazing behavior. The study took 63 d using 32 multiparous Holstein-Friesian dairy cows. Prior to experimental treatment, milk production averaged 20.2 ± 1.7 kg d-1, body weight was 503 ± 19 kg, and days in milking were 103 ± 6. Experimental animals were randomly assigned to two treatments according to HA offered above ground level: low (17 kg DM cow-1 d-1 vs. high HA (25 kg DM cow¹ d¹. All cows were supplemented with grass silage supplying daily 6.25 and 4.6 kg DM of concentrate (concentrate commercial plus high corn moisture. Decreasing HA influenced positively milk production (+25%, milk protein (+20 kg, and milk fat (+17 kg per hectare; however no effects on milk production per cow or energy metabolic status were observed in the cows. In conclusion, a low HA showed to be the most significant influencing factor on milk and milk solids production per hectare in dairy cows grazing restricted winter and supplemented with grass silage and concentrate; but no effect on the milk production per cow was found.

Utilisation of metallurgical by-products in road construction in the Czech Republic

Science.gov (United States)

Kresta, František

2017-09-01

Metallurgical by-products, primarily blast furnace slag and steel slag, have ranked among important alternative sources of fill as well as of material for the structural layers in highways. Main hazards of metallurgical by-products are closely connected to their chemical and mineralogical composition and they can be resulted in volume changes. Fears from possible deformations similar to the D47 motorway meant that metallurgical by-products were excluded from several public tenders of road construction. Comparison of blast furnace slag, steel slag and other metallurgical by products parameters allow us to define the most hazardous material as steelworks waste. Linear swelling of steelwork waste achieves more than 40% at 75°C and swelling pressure was higher than 1.5 MPa. Compositional heterogeneity of steelworks waste makes it difficult to establish the long-term behaviour of this material. At the present time we cannot ascertain which maximum values can be reached by deformation and what are the swelling pressures acting on the material while the volume changes are in progress.

Soil contamination of plant surfaces from grazing and rainfall interactions

International Nuclear Information System (INIS)

Hinton, T.G.; Stoll, J.M.; Tobler, L.

1995-01-01

Contaminants often attach to soil particles, and their subsequent environmental transport is largely determined by processes that govern soil movement. We examined the influence of grazing intensity on soil contamination of pastures. Four different grazing densities of sheep were tested against an ungrazed control plot. Scandium concentrations were determined by neutron activation analysis and was used as a tracer of soil adhesion on vegetation. Soil loadings ( g soil kg -1 dry plant) increased 60% when grazing intensity was increased by a factor of four (p 0.003). Rain and wind removed soil from vegetation in the ungrazed control plots, but when grazing sheep were present, an increase in rain from 0.3 to 9.7 mm caused a 130% increase in soil contamination. Multiple regression was used to develop an equation that predicts soil loadings as a function of grazing density, rainfall and wind speed (p = 0.0001, r 2 = 0.78). The model predicts that if grazing management were to be used as a tool to reduce contaminant intake from inadvertent consumption of resuspended soil by grazing animals, grazing densities would have to be reduced 2.5 times to reduce soil loadings by 50%. (author)

Developmental instability and fitness in Periploca laevigata experiencing grazing disturbance

Science.gov (United States)

Alados, C.L.; Giner, M.L.; Dehesa, L.; Escos, J.; Barroso, F.; Emlen, J.M.; Freeman, D.C.

2002-01-01

We investigated the sensitivity of developmental instability measurements (leaf fluctuating asymmetry, floral radial asymmetry, and shoot translational asymmetry) to a long‐standing natural stress (grazing) in a palatable tannin‐producing shrub (Periploca laevigata Aiton). We also assessed the relationship between these measures of developmental instability and fitness components (growth and floral production). Developmental instability, measured by translational asymmetry, was the most accurate estimator of a plant’s condition and, consequently, environmental stress. Plants with less translational asymmetry grew more and produced more flowers. Plants from the medium‐grazed population were developmentally more stable, as estimated by translational and floral asymmetry, than either more heavily or more lightly grazed populations. Leaf fluctuating asymmetry was positively correlated with tannin concentration. The pattern of internode growth also responded to grazing impact. Plants under medium to heavy grazing pressure accelerated early growth and consequently escaped herbivory later in the season, i.e., at the beginning of the spring, when grazing activity was concentrated in herbaceous plants. Periploca laevigata accelerated growth and finished growing sooner than in the other grazing treatment. Thus, its annual growth was more mature and less palatable later in the season when grazers typically concentrate on shrubs. The reduction of developmental instability under medium grazing is interpreted as a direct effect of grazing and not as the release from competition.

Comparison of the yields of downstream migrant salmonids before and after logging and road construction on the South Fork Caspar Creek, Mendocino County

Science.gov (United States)

David S. Graves; James W. Burns

1970-01-01

Yields of juvenile steelhead rainbow trout Salmo gairdnerii gairdnerii) and silver salmon (Oncorhynchus kisutch) emigrants were compared in South Fork Caspar Creek, a small coastal stream in Mendocino County, California, before and after construction of a logging road along the stream in the summer of 1967. Numbers, lengths, and age class structures were compared....

Effects of grazing system on production and parasitism of dairy breed heifers and steers grazing wet marginal grasslands

DEFF Research Database (Denmark)

Kristensen, Troels; Thamsborg, S.M.; Andersen, Refsgaard

2006-01-01

Production and endoparasitism of first grazing season Holstein heifers and steers were investigated over two grazing seasons. Studies were conducted on low-lying peaty soil. In year 2000, 40 animals were included in a 2x2 factorial, replicated experiment with two sexes (steers v. heifers) and two...

Modelling traffic hindrance caused by road construction as part of a multi-criteria assessment framework

NARCIS (Netherlands)

van Berkum, Eric C.; ter Huerne, Henderikus L.; Jacob, B.; Kovarik, J.; Motyka, V.

2014-01-01

One of the consequences of the increased utilization of road infrastructure is more frequent maintenance work. Since generally road works result in less available road capacity, we can witness an increase in traffic hindrance, which involves delays and externalities as noise, air quality, safety and

Modernization of the Russian Automobile Road Network on the Base of Innovative Technologies

Directory of Open Access Journals (Sweden)

E. A. Zhukov

2017-01-01

Full Text Available Purpose: the main goal of the article is to build a conceptual model for the organization of effective functioning of the points of economic and innovative growth of the region in modern conditions, taking into account regional and municipal limitations of internal and external nature, with the aim of ensuring economic security, effective interaction of subjects of the "business-power" system Taking into account the influence of institutional factors. Methods: in the present study the following methods were used: systemic approach, methods of social diagnosis, comparative analysis, method of expert evaluations, and method of statistical processing of information. Results: the short characteristic of modern development and technical level of the Russian automobile roads network as the important part of the automobile roads material-technical base is presented. Realization process of the actual task putted by Russian President V.V. Putin to transport builders: two times increasing construction of automobile roads is analyzed. The reality of decision this task due to modernization roads economy material-technical base on the base of innovative technologies and progressive world experience in the field of roads construction is scientifically proved. Conclusions and Relevance: in spite of losing now in decision of the actual task putted by Russian President V.V. Putin to transport builders: two times increasing construction of automobile roads, nevertheless the real possibilities to reach the important aim still remain. It may be done only due to scientifically grounded modernization of the roads economy material-technical base on the base of innovative technologies and progressive world experience in the field of roads construction 

Evaluation of leachate emissions from crushed rock and municipal solid waste incineration bottom ash used in road construction.

Science.gov (United States)

Lidelöw, S; Lagerkvist, A

2007-01-01

Three years of leachate emissions from municipal solid waste incineration bottom ash and crushed rock in a full-scale test road were evaluated. The impact of time, construction design, and climate on the emissions was studied, and the predicted release from standard leaching tests was compared with the measured release from the road. The main pollutants and their respective concentrations in leachate from the roadside slope were Al (12.8-85.3 mg l(-1)), Cr (2-125 microg l(-1)), and Cu (0.15-1.9 mg l(-1)) in ash leachate and Zn (1-780 microg l(-1)) in crushed rock leachate. From the ash, the initial Cl(-) release was high ( approximately 20 g l(-1)). After three years, the amount of Cu and Cl(-) was in the same range in both leachates, while that of Al and Cr still was more than one order of magnitude higher in ash leachate. Generally, the release was faster from material in the uncovered slopes than below the pavement. Whether the road was asphalted or not, however, had minor impacts on the leachate quality. During rain events, diluted leachates with respect to, e.g., salts were observed. The leaching tests failed to simulate field leaching from the crushed rock, whereas better agreement was observed for the ash. Comparisons of constituent release from bottom ash and conventional materials solely based on such tests should be avoided.

Assessment of Quality of Asphalt Concrete used in Road ...

African Journals Online (AJOL)

OLUWASOGO

to layers beneath without compromising durability. The premature failure of road pavement shortly after construction or rehabilitation without meeting its designed life span has become a major challenge to highway engineers, contractors and the government in Nigeria. A study carried out by Federal Road Safety Corps of ...

Urban Road Transportation in Nigeria From 1960 To 2006 ...

African Journals Online (AJOL)

It was discovered that urban road transport system in Nigeria is inefficient and grossly inadequate even after 46 years of becoming independent from Colonial Rule. The paper suggested the construction of more motor-able roads within cities in order to increase the network; encourage increased public and private ...

The ecological impact assessment of a proposed road development (the Slovak approach)

International Nuclear Information System (INIS)

Igondova, Erika; Pavlickova, Katarina; Majzlan, Oto

2016-01-01

The construction of roads is one of the most widespread forms of natural landscape modification. Over the last 20 years, dozens of road constructions have been assessed in Slovakia, which makes it possible to talk about methodological positives and negatives. A special feature of Slovakia is that many planned or renovated roads are located in protected areas or are in contact with them (including Natura 2000 sites). Therefore, it is important to understand the scope of the roads' ecological impacts and find ways for their appropriate evaluation and incorporation into the Environmental Impact Assessment process. For this reason, the Ecological Impact Assessment methodology can be used as a basis for our research, which consists of three stages. In the first stage (scoping), a buffer circumventing the proposed road is created to determine the area for impact prediction and evaluation. Subsequently, the landscape structure and baseline landscape conditions are discussed, a map of current landscape structure is created and the current ecological status of the affected area is calculated. In the second stage (the evaluation of ecological resources), important ecological parts of the landscape are delineated. This step is based on the importance of previous information and its vulnerability, and leads to the mapping of the road ecological impact zone. In the third stage (impact assessment), important ecological parts are spatially correlated with the proposed road construction. Finally, the significance of ecological impacts of the activity is evaluated by applying specific criteria (duration, reversibility, magnitude, size and road ecological impact zone significance). A scale is proposed for each criterion to evaluate the total significance of impacts. In this way, detailed significant ecological impacts can be found which will help lead to proposed correct mitigation measures and a post-project analysis. - Highlights: • This paper proposes a methodology for the Ec

The ecological impact assessment of a proposed road development (the Slovak approach)

Energy Technology Data Exchange (ETDEWEB)

Igondova, Erika, E-mail: erika.igondova@gmail.com; Pavlickova, Katarina, E-mail: pavlickova60@gmail.com; Majzlan, Oto, E-mail: majzlan@fns.uniba.sk

2016-07-15

The construction of roads is one of the most widespread forms of natural landscape modification. Over the last 20 years, dozens of road constructions have been assessed in Slovakia, which makes it possible to talk about methodological positives and negatives. A special feature of Slovakia is that many planned or renovated roads are located in protected areas or are in contact with them (including Natura 2000 sites). Therefore, it is important to understand the scope of the roads' ecological impacts and find ways for their appropriate evaluation and incorporation into the Environmental Impact Assessment process. For this reason, the Ecological Impact Assessment methodology can be used as a basis for our research, which consists of three stages. In the first stage (scoping), a buffer circumventing the proposed road is created to determine the area for impact prediction and evaluation. Subsequently, the landscape structure and baseline landscape conditions are discussed, a map of current landscape structure is created and the current ecological status of the affected area is calculated. In the second stage (the evaluation of ecological resources), important ecological parts of the landscape are delineated. This step is based on the importance of previous information and its vulnerability, and leads to the mapping of the road ecological impact zone. In the third stage (impact assessment), important ecological parts are spatially correlated with the proposed road construction. Finally, the significance of ecological impacts of the activity is evaluated by applying specific criteria (duration, reversibility, magnitude, size and road ecological impact zone significance). A scale is proposed for each criterion to evaluate the total significance of impacts. In this way, detailed significant ecological impacts can be found which will help lead to proposed correct mitigation measures and a post-project analysis. - Highlights: • This paper proposes a methodology for the

Grazing behavior and production characteristics among cows differing in residual feed intake while grazing late season Idaho rangeland

Science.gov (United States)

The objectives were to determine if cows classified as either low- or high-residual feed intake (LRFI or HRFI) differed in BW, BCS, and winter grazing activity over time. Thirty Hereford x Angus (LRFI = 16; HRFI = 14) 2-year-old cows grazed sagebrush-steppe for 78 d beginning 29 September 2016. Body...

Submicron particle monitoring of paving and related road construction operations.

Science.gov (United States)

Freund, Alice; Zuckerman, Norman; Baum, Lisa; Milek, Debra

2012-01-01

This study identified activities and sources that contribute to ultrafine and other submicron particle exposure that could trigger respiratory symptoms in highway repair workers. Submicron particle monitoring was conducted for paving, milling, and pothole repair operations in a major metropolitan area where several highway repair workers were identified as symptomatic for respiratory illness following exposures at the 2001 World Trade Center disaster site. Exposure assessments were conducted for eight trades involved in road construction using a TSI P-Trak portable condensation particle counter. Direct readings near the workers' breathing zones and observations of activities and potential sources were logged on 7 days on 27 workers using four different models of pavers and two types of millers. Average worker exposure levels ranged from 2 to 3 times background during paving and from 1 to 4 times background during milling. During asphalt paving, average personal exposures to submicron particulates were 25,000-60,000, 28,000-70,000, and 23,000-37,000 particles/ cm(3) for paver operators, screed operators, and rakers, respectively. Average personal exposures during milling were 19,000-111,000, 28,000-81,000, and 19,000 particles/cm(3) for the large miller operators, miller screed operators, and raker, respectively. Personal peak exposures were measured up to 467,000 and 455,000 particles/cm(3) in paving and milling, respectively. Several sources of submicron particles were identified. These included the diesel and electric fired screed heaters; engine exhaust from diesel powered construction vehicles passing by or idling; raking, dumping, and paving of asphalt; exhaust from the hotbox heater; pavement dust or fumes from milling operations, especially when the large miller started and stopped; and secondhand cigarette smoke. To reduce the potential for health effects in workers, over 40 recommendations were made to control exposures, including improved maintenance of

75 FR 29572 - Information Collection; Grazing Management

Science.gov (United States)

2010-05-26

... Control Number 1004-0019] Information Collection; Grazing Management AGENCY: Bureau of Land Management... submitted an information collection request to the Office of Management and Budget (OMB) for a 3-year... INFORMATION: Title: Grazing Management (43 CFR 4120). OMB Number: 1004-0019. Forms: 4120-6 (Cooperative Range...

Bivalve grazing can shape phytoplankton communities

Science.gov (United States)

Lucas, Lisa; Cloern, James E.; Thompson, Janet K.; Stacey, Mark T.; Koseff, Jeffrey K.

2016-01-01

The ability of bivalve filter feeders to limit phytoplankton biomass in shallow waters is well-documented, but the role of bivalves in shaping phytoplankton communities is not. The coupled effect of bivalve grazing at the sediment-water interface and sinking of phytoplankton cells to that bottom filtration zone could influence the relative biomass of sinking (diatoms) and non-sinking phytoplankton. Simulations with a pseudo-2D numerical model showed that benthic filter feeding can interact with sinking to alter diatom:non-diatom ratios. Cases with the smallest proportion of diatom biomass were those with the fastest sinking speeds and strongest bivalve grazing rates. Hydrodynamics modulated the coupled sinking-grazing influence on phytoplankton communities. For example, in simulations with persistent stratification, the non-sinking forms accumulated in the surface layer away from bottom grazers while the sinking forms dropped out of the surface layer toward bottom grazers. Tidal-scale stratification also influenced vertical gradients of the two groups in opposite ways. The model was applied to Suisun Bay, a low-salinity habitat of the San Francisco Bay system that was transformed by the introduction of the exotic clam Potamocorbula amurensis. Simulation results for this Bay were similar to (but more muted than) those for generic habitats, indicating that P. amurensis grazing could have caused a disproportionate loss of diatoms after its introduction. Our model simulations suggest bivalve grazing affects both phytoplankton biomass and community composition in shallow waters. We view these results as hypotheses to be tested with experiments and more complex modeling approaches.

White clover regenerative ability under N fertilizing and grazing

Directory of Open Access Journals (Sweden)

Josip Leto

2008-12-01

Full Text Available Recently, ecological and economic factors in milk and meat production stimulate use of legumes and grass-legumes mixtures, with zero or minimum mineral N as alternative to grass monoculture with high rate of mineral N. Research objective was to examine the effect of N application (0-N0 and 150 kg ha-1 year-1-N150 and rotational grazing by cattle (C and sheep (S on white clover: growing points number, stolon lenght, stolon dry weight, dry matter yield and clover contribution to total annual herbage production. N150 significantly reduced the growing points number, stolon length and stolon dry weight for more than 70 % compared to N0. Grazing treatment affected stolon population density only in interaction with N application because of N150 significantly reduced white clover population density only in sheep grazing. S-treatment had higher clover DM yield (0.21 t ha-1 than C-treatment (0.13 t ha-1. N0 had higher clover DM yield (0.25 t ha-1 than N150 (0.09 t ha-1. However, the interaction grazing management x N rate was significant for clover DM yield and clover contribution to total DM yield. N150 reduced both parameters for 80 % only in sheep grazing while difference in DM yield and clover contribution to total DM yield between grazing treatment was recorded only in N0 Sheep grazing increased DM yield for 150 % and clover contribution for 99 % compared to cattle grazing.

Evidence for strain-specific exometabolomic responses of the coccolithophore Emiliania huxleyi to grazing by the dinoflagellate Oxyrrhis marina.

Directory of Open Access Journals (Sweden)

Kelsey L Poulson-Ellestad

2016-01-01

Full Text Available The coccolithophore Emiliania huxleyi forms massive blooms and plays a critical role in global elemental cycles, sequestering significant amounts of atmospheric carbon dioxide on geological time scales via production of calcium carbonate coccoliths and emitting dimethyl sulfoniopropionate (DMSP which has the potential for increasing atmospheric albedo. Because grazing in pelagic systems is a major top-down force structuring microbial communities, the influence of grazers on E. huxleyi populations has been of interest to researchers. Roles of DMSP (and related metabolites in interactions between E. huxleyi and protist grazers have been investigated, however, little is known about the release of other metabolites that may influence, or be influenced by, such grazing interactions. We used high-resolution mass spectrometry in an untargeted approach to survey the suite of low molecular weight compounds released by four different E. huxleyi strains in response to grazing by the dinoflagellate Oxyrrhis marina. Overall, a strikingly small number of metabolites were detected from E. huxleyi and O. marina cells, but these were distinctly informative to construct metabolic footprints. At most, E. huxleyi strains shared 25% of released metabolites. Furthermore, there appeared to be no unified metabolic response in E. huxleyi strains to grazing; rather these responses were strain specific. Concentrations of several metabolites also positively correlated with grazer activities, including grazing, ingestion, and growth rates; however, no single metabolite responded uniformly across all strains of E. huxleyi tested. Regardless, grazing clearly transformed the constituents of dissolved organic matter produced by these marine microbes. This study addresses several technical challenges, and presents a platform to further study the influence of chemical cues in aquatic systems and demonstrates the impact of strain diversity and grazing on the complexity of

Mixed grazing systems benefit both upland biodiversity and livestock production.

Directory of Open Access Journals (Sweden)

Mariecia D Fraser

Full Text Available With world food demand expected to double by 2050, identifying farming systems that benefit both agricultural production and biodiversity is a fundamentally important challenge for the 21(st century, but this has to be achieved in a sustainable way. Livestock grazing management directly influences both economic outputs and biodiversity on upland farms while contributing to potentially damaging greenhouse gas emissions, yet no study has attempted to address these impacts simultaneously.Using a replicated, landscape-scale field experiment consisting of five management 'systems' we tested the effects of progressively altering elements within an upland farming system, viz i incorporating cattle grazing into an upland sheep system, ii integrating grazing of semi-natural rough grazing into a mixed grazing system based on improved pasture, iii altering the stocking ratio within a mixed grazing system, and iv replacing modern crossbred cattle with a traditional breed. We quantified the impacts on livestock productivity and numbers of birds and butterflies over four years.We found that management systems incorporating mixed grazing with cattle improve livestock productivity and reduce methane emissions relative to sheep only systems. Systems that also included semi-natural rough grazing consistently supported more species of birds and butterflies, and it was possible to incorporate bouts of summer grazing of these pastures by cattle to meet habitat management prescriptions without compromising cattle performance overall. We found no evidence that the system incorporating a cattle breed popular as a conservation grazer was any better for bird and butterfly species richness than those based on a mainstream breed, yet methane emissions from such a system were predicted to be higher. We have demonstrated that mixed upland grazing systems not only improve livestock production, but also benefit biodiversity, suggesting a 'win-win' solution for farmers and

High motility reduces grazing mortality of planktonic bacteria

DEFF Research Database (Denmark)

Matz, Carsten; Jurgens, K.

2005-01-01

We tested the impact of bacterial swimming speed on the survival of planktonic bacteria in the presence of protozoan grazers. Grazing experiments with three common bacterivorous nanoflagellates revealed low clearance rates for highly motile bacteria. High-resolution video microscopy demonstrated...... size revealed highest grazing losses for moderately motile bacteria with a cell size between 0.2 and 0.4 mum(3). Grazing mortality was lowest for cells of >0.5 mum(3) and small, highly motile bacteria. Survival efficiencies of >95% for the ultramicrobacterial isolate CP-1 (less than or equal to0.1 mum......(3), >50 mum s(-1)) illustrated the combined protective action of small cell size and high motility. Our findings suggest that motility has an important adaptive function in the survival of planktonic bacteria during protozoan grazing....

Landscapes of Memory and Forgetting: Memorialisation, Emotion and Tourism along Australia’s Great Ocean Road

Directory of Open Access Journals (Sweden)

Rosemary Kerr

2013-12-01

Full Text Available This article explores the history of the Great Ocean Road, described in its recent National Heritage listing as “Australia’s most famous coastal drive”. The road is unique in Australia as it was purposely constructed as a scenic tourist route and as a memorial to World War I servicemen. Over time the road’s memorial function was largely forgotten in public memory, overtaken by its fame as a tourist route. The history of the road’s setting, construction, promotion and interpretation reveals that it is a route which reflects changing, and sometimes conflicting, cultural preoccupations. Despite attempts to link its sublime setting and challenges of building the road with the heroic struggles of the servicemen in war; in spite of physical commemorative markers along the road; and in spite of the power and endurance of the “Anzac legend” in Australian culture, the connection did not resonate as intended. The road’s construction and subsequent interpretation illustrate the difficulty of inscribing “memory” onto a landscape with no prior connection to the events being memorialised. Its history reveals insights into the road’s cultural construction; tangible and intangible expressions of remembering and forgetting along the road; and the relationship between the road, landscape, memory and emotion.

Improving concrete overlay construction.

Science.gov (United States)

2010-03-01

Several road construction projects involving concrete overlays at the state and county levels in Iowa in 2009 were studied for : construction techniques and methods. The projects that were evaluated consisted of sites in four Iowa counties: Osceola, ...

THE GREAT SILK ROAD BECOMES THE GREAT OIL AND GAS ROAD

Directory of Open Access Journals (Sweden)

I. S. Zonn

2015-01-01

Full Text Available The Great Silk Road (GSR called so in the late 19th century by German geographer Ferdinand von Richthofen started shaping in the 2nd century B.C. In the minds of peoples the Silk Road is a generalized symbol of trade caravan routes crossing Central Asia, connecting until the 16th century the Far East, in particular Japan, China, with Middle Asia. Appearance in the early 21st century of new independent states in Central Asia along the GSR route was a powerful impetus for revival of the ancient trade route. In September 2013 Xi Jinping, President of the People's Republic of China, during his visit to the Central Asian countries offered the strategic concept of joint construction of the “economic corridor along the Silk Road” based on innovative cooperation in order to revive and consolidate the economic contacts among the Eurasian countries. Establishment of the modern analog of GSR, a powerful transport and pipeline corridor includes the integrated system of railroads and automobile roads, oil and gas pipelines, airlines, and sea lines.

Effects of Roads on Amphibian Populations

DEFF Research Database (Denmark)

Hels, T.

is the result of my three year PhD study at the National Environmental Research Institute, Kalø, and University of Copenhagen. Funded by NERI, the Danish Research Academy, and the Danish Road Directorate, it has dealt mainly with the effects of traffic and roads on amphibian populations. The Spadefoot toad...... of Spadefoot toads (Pelobates fuscus Laur.) II The effect of road kills on amphibian populations III Simulating viability of a Spadefoot toad (P. fuscus) metapopulation in a landscape fragmented by a road The manuscripts are preceded by a synopsis which sums up the work and puts it into a broader perspective......, Johan Elmberg, Andreas Seiler, and Per Sjögren-Gulve, for sharing your knowledge and enthusiasm for science with me. Constructive ideas, different approaches, and elaborate discussions are crucial parts of any scientific process: I thank Lenore Fahrig for dedicated and original teaching and discussions...

Maslow Revisited: Constructing a Road Map of Human Nature

Science.gov (United States)

O'Connor, Dennis; Yballe, Leodones

2007-01-01

Given the scope and intent of Maslow's work, the current textbook treatment is wanting. Therefore, an inductive exercise has been created and is offered here to build "the road map of human nature." This age-old, philosophic focus on our true nature has been a way to successfully engage and inspire both our students and our pedagogy. In the spirit…

Longer rest periods for intensive rotational grazing limit diet quality ...

African Journals Online (AJOL)

Longer rest periods for intensive rotational grazing limit diet quality of sheep without enhancing environmental benefits. ... This experiment was established to compare three intensive rotational grazing strategies (fast rotation [FR], average 57-day rest; slow rotation [SR], average 114-day rest; and flexible grazing [FX], based ...

Nuclear gauge application in road industry

Science.gov (United States)

Azmi Ismail, Mohd

2017-11-01

Soil compaction is essential in road construction. The evaluation of the degree of compaction relies on the knowledge of density and moisture of the compacted layers is very important to the performance of the pavement structure. Among the various tests used for making these determinations, the sand replacement density test and the moisture content determination by oven drying are perhaps the most widely used. However, these methods are not only time consuming and need wearisome procedures to obtain the results but also destructive and the number of measurements that can be taken at any time is limited. The test can on be fed back to the construction site the next day. To solve these problems, a nuclear technique has been introduced as a quicker and easier way of measuring the density and moisture of construction materials. Nuclear moisture density gauges have been used for many years in pavement construction as a method of non-destructive density testing The technique which can determine both wet density and moisture content offers an in situ method for construction control at the work site. The simplicity, the speed, and non-destructive nature offer a great advantage for quality control. This paper provides an overview of nuclear gauge application in road construction and presents a case study of monitoring compaction status of in Sedenak - Skudai, Johor rehabilitation projects.

A Method for Extracting Road Boundary Information from Crowdsourcing Vehicle GPS Trajectories.

Science.gov (United States)

Yang, Wei; Ai, Tinghua; Lu, Wei

2018-04-19

Crowdsourcing trajectory data is an important approach for accessing and updating road information. In this paper, we present a novel approach for extracting road boundary information from crowdsourcing vehicle traces based on Delaunay triangulation (DT). First, an optimization and interpolation method is proposed to filter abnormal trace segments from raw global positioning system (GPS) traces and interpolate the optimization segments adaptively to ensure there are enough tracking points. Second, constructing the DT and the Voronoi diagram within interpolated tracking lines to calculate road boundary descriptors using the area of Voronoi cell and the length of triangle edge. Then, the road boundary detection model is established integrating the boundary descriptors and trajectory movement features (e.g., direction) by DT. Third, using the boundary detection model to detect road boundary from the DT constructed by trajectory lines, and a regional growing method based on seed polygons is proposed to extract the road boundary. Experiments were conducted using the GPS traces of taxis in Beijing, China, and the results show that the proposed method is suitable for extracting the road boundary from low-frequency GPS traces, multi-type road structures, and different time intervals. Compared with two existing methods, the automatically extracted boundary information was proved to be of higher quality.

A Method for Extracting Road Boundary Information from Crowdsourcing Vehicle GPS Trajectories

Directory of Open Access Journals (Sweden)

Wei Yang

2018-04-01

Full Text Available Crowdsourcing trajectory data is an important approach for accessing and updating road information. In this paper, we present a novel approach for extracting road boundary information from crowdsourcing vehicle traces based on Delaunay triangulation (DT. First, an optimization and interpolation method is proposed to filter abnormal trace segments from raw global positioning system (GPS traces and interpolate the optimization segments adaptively to ensure there are enough tracking points. Second, constructing the DT and the Voronoi diagram within interpolated tracking lines to calculate road boundary descriptors using the area of Voronoi cell and the length of triangle edge. Then, the road boundary detection model is established integrating the boundary descriptors and trajectory movement features (e.g., direction by DT. Third, using the boundary detection model to detect road boundary from the DT constructed by trajectory lines, and a regional growing method based on seed polygons is proposed to extract the road boundary. Experiments were conducted using the GPS traces of taxis in Beijing, China, and the results show that the proposed method is suitable for extracting the road boundary from low-frequency GPS traces, multi-type road structures, and different time intervals. Compared with two existing methods, the automatically extracted boundary information was proved to be of higher quality.

Preparation of Road Cuts by Usage of Drilling and Blasting Works

OpenAIRE

Dambov, Risto; Mijoski, Goran; Karanakova Stefanovska, Radmila

2011-01-01

This paper shows the basic methods of blasting in the construction of the (one-sided and double sided) road cuts in hilly terrain with different inclinations. By applying of these methods we get stable slopes of manufactured road cuts, minimal (or no) damage of the rest solid rocks. It is important to emphasize that the stable and undeformed slopes of the road cuts, to avoid the additional work of restoration and protection of slopes from landslides on the road. The application of these...

Unofficial Road Building in the Amazon: Socioeconomic and Biophysical Explanations

Science.gov (United States)

Perz, Stephen G.; Caldas, Marcellus M.; Arima, Eugenio; Walker, Robert J.

2007-01-01

Roads have manifold social and environmental impacts, including regional development, social conflicts and habitat fragmentation. 'Road ecology' has emerged as an approach to evaluate the various ecological and hydrological impacts of roads. This article aims to complement road ecology by examining the socio-spatial processes of road building itself. Focusing on the Brazilian Amazon, a heavily-studied context due to forest fragmentation by roads, the authors consider non-state social actors who build 'unofficial roads' for the purpose of gaining access to natural resources to support livelihoods and community development. They examine four case studies of roads with distinct histories in order to explain the socio-spatial processes behind road building in terms of profit maximization, land tenure claims, co-operative and conflictive political ecologies, and constraints as well as opportunities afforded by the biophysical environment. The study cases illustrate the need for a multi-pronged theoretical approach to understanding road building, and call for more attention to the role of non-state actors in unofficial road construction.

Zooplankton grazing in a eutrophic lake: implications of diel vertical migration

International Nuclear Information System (INIS)

Lampert, W.; Taylor, B.E.

1985-01-01

During summer and fall, depth profiles of zooplankton community grazing were determined in situ during day and night in the Schoehsee, a small eutrophic lake. Labeled algae of two different sizes were mixed with the natural suspension of phytoplankton in a grazing chamber. A small blue-green alga (Synechococcus, 1 μm) was labeled with 32 P; a larger green alga (Scenedesmus, 4-15 μm) was labeled with 14 C. During summer, grazing in the upper 5 m was negligible during day but strong at night. Hence, algae grow relatively unimpeded by grazing during daytime but are harvested at night. Vertical and diel differences in grazing rates disappeared when the vertical migration ceased in fall. Selectivity of grazing was controlled by the zooplankton species composition. Eudiaptomus showed a strong preference for Scenedesmus. Daphnia showed a slight preference for Scenedesmus, but Ceriodaphnia preferred Synechococcus. Cyclopoid copepodites did not ingest the small blue-green. Because Daphnia and Eudiaptomus were dominant, grazing rates on larger cells were usually higher than grazing rates on the small cells. Negative electivity indices for scenedesmus occurred only when the biomass of large crustaceans was extremely low (near the surface, during day). Zooplankton biomass was the main factor controlling both vertical and seasonal variations in grazing. Highest grazing rates (65%/d) were measured during fall when zooplankton abundance was high. Because differential losses can produce substantial errors in the results, it was necessary to process the samples on the boat immediately after collection, without preservation

Bison grazing increases arthropod abundance and diversity in a tallgrass prairie.

Science.gov (United States)

Moran, Matthew D

2014-10-01

How grazing-induced ecosystem changes by ungulates indirectly affect other consumers is a question of great interest. I investigated the effect of grazing by American Bison (Bos bison L.) on an arthropod community in tallgrass prairie. Grazing increased the abundance of arthropods, an increase that was present in both herbivorous and carnivorous assemblages, but not in detritivores. The increase in herbivores and reduction in plant biomass from grazing resulted in an arthropod herbivore load almost three times higher in grazed plots compared with controls. Among herbivores, the sap-feeding insect guild was dramatically more abundant, while chewing herbivores were not affected. Herbivorous and carnivorous arthropod richness was higher in grazed plots, although the response was strongest among herbivores. Arthropod abundance on individual grasses and forbs was significantly higher in grazed areas, while plant type had no effect on abundance, indicating that the change was ecosystem-wide and not simply in response to a reduction in grass biomass from grazing. The response of arthropods to grazing was strongest in the early part of the growing season. Published research shows that ungulate grazing, although decreasing available biomass to other consumers, enhances plant quality by increasing nitrogen level in plants. The arthropod results of this study suggest higher plant quality outweighs the potential negative competitive effects of plant biomass removal, although other activities of bison could not be ruled out as the causative mechanism. Because arthropods are extremely abundant organisms in grasslands and a food source for other consumers, bison may represent valuable management tools for maintaining biodiversity.

Introducing cattle grazing to a noxious weed-dominated rangeland shifts plant communities

Directory of Open Access Journals (Sweden)

Josh S. Davy

2015-10-01

Full Text Available Invasive weed species in California's rangelands can reduce herbaceous diversity, forage quality and wildlife habitat. Small-scale studies (5 acres or fewer have shown reductions of medusahead and yellow starthistle using prescribed grazing on rangelands, but little is published on the effects of pasture-scale (greater than 80 acres prescribed grazing on weed control and plant community responses. We report the results of a 6-year collaborative study of manager-applied prescribed grazing implemented on rangeland that had not been grazed for 4 years. Grazing reduced medusahead but did not alter yellow starthistle cover. Medusahead reductions were only seen in years that did not have significant late spring rainfall, suggesting that it is able to recover from heavy grazing if soil moisture is present. Later season grazing appears to have the potential to suppress medusahead in all years. In practice, however, such grazing is constrained by livestock drinking water availability and forage quality, which were limited even in years with late spring rainfall. Thus, we expect that grazing treatments under real-world constraints would reduce medusahead only in years with little late spring rainfall. After 10 years of grazing exclusion, the ungrazed plant communities began to shift, replacing medusahead with species that have little value, such as ripgut and red brome.

36 CFR 251.103 - Mediation of term grazing permit disputes.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Mediation of term grazing... Lands § 251.103 Mediation of term grazing permit disputes. (a) Decisions subject to mediation. In those States with Department of Agriculture certified mediation programs, any holder of a term grazing permit...

A new spectrometer for grazing incidence X-ray fluorescence for the characterization of Arsenic implants and Hf based high-k layers

International Nuclear Information System (INIS)

Ingerle, D.; Meirer, F.; Zoeger, N.; Pepponi, G.; Giubertoni, D.; Steinhauser, G.; Wobrauschek, P.; Streli, C.

2010-01-01

Grazing Incidence X-ray Fluorescence Analysis (GIXRF) is a powerful technique for depth-profiling and characterization of thin layers in depths up to a few hundred nanometers. By measurement of fluorescence signals at various incidence angles Grazing Incidence X-ray Fluorescence Analysis provides information on depth distribution and total dose of the elements in the layers. The technique is very sensitive even in depths of a few nanometers. As Grazing Incidence X-ray Fluorescence Analysis does not provide unambigous depth profile information and needs a realistic input depth profile for fitting, in the context of the EC funded European Integrated Activity of Excellence and Networking for Nano and Micro-Electronics Analysis (ANNA) Grazing Incidence X-ray Fluorescence Analysis is used as a complementary technique to Secondary Ion Mass Spectrometry (SIMS) for the characterization of Ultra Shallow Junctions (USJ). A measuring chamber was designed, constructed and tested to meet the requirements of Grazing Incidence X-ray Fluorescence Analysis. A measurement protocol was developed and tested. Some results for As implants as well as Hf based high k layers on Silicon are shown. For the determination of the bulk As content of the wafers, Instrumental Neutron Activation Analysis has also been applied for comparison.

MODERN CONDITIONS OF ROAD FACILITIES AND INTERNATIONAL AUTOMOTIVE TRANSPORTATION OF THE REPUBLIC OF BELARUS

Directory of Open Access Journals (Sweden)

I. M. Tsarenkova

2008-01-01

Full Text Available For analysis of technical and economic conditions of automotive roads and determination of reserves for improvement of financial situation and usage of capital in road facilities operational efficiency of road facilities and automotive freight-traffic services that provide significant currency receipt for Republic budget. The main ways for higher export of construction services are involvement of road facilities enterprises in this activity and introduction of highly-productive technologies in their operation. The paper demonstrates an importance of non-conventional sources of investment attractions such as leasing which is used for renovation of capital assets and invests resources in the basic capital on the return basis in the natural form. For application of new technologies and modern technique it is justifiable to establish joint road-construction enterprises with foreign sub-contractors. The paper reveals main reasons of profit increase due to operation and services of road branch.

Heating of roads. Heat consumption and heat output as a function of climate, construction, demands on surface conditions and principle of heat supply. Uppvaermning av vaegar

Energy Technology Data Exchange (ETDEWEB)

Magnusson, R

1977-01-01

In this work analytical formulas for calculation of temperatures in a heated roadbed are given. The heat flux from a heated surface has been studied. The methods for snowclearence on different types of roads have been investigated. The construction work has been studied. The analytical formulas have been evaluated by comparison between calculated temperatures and temperatures measured in field and laboratory. The heat transfer coefficients in those formulas have been developed empirically by tests in laboratory and field. Surfaces with different types of traffic are divided into three classes according to the demands for snow removal. The construction work has been divided into cost elements. This has given a basis for calculating the economic effects of alternative designs. By this work has been developed a method useful on one hand for calculation of the optimum principle of regulation of the supply of heat and on the other hand for the design of the heat installations in the road.

Grazing-incident PIXE Analysis Technology

International Nuclear Information System (INIS)

Li Hongri; Wang Guangpu; Liang Kun; Yang Ru; Han Dejun

2009-01-01

In the article, the grazing incidence technology is first applied to the PIXE (proton induced X-ray emission) analysis. Three pieces of samples were investigated, including the contaminated aluminium substrate, the SIMOX (separated by oxygen implantation) SOI (Silicon on Insulator) sample and the silicon wafer implanted with Fe + . The results reveal that the grazing-incident proton can improve the sensitivity of PIXE in trace analysis, especially for samples contaminated on surface. With the penetration depth of the proton bean decreased, the ratio of the peak area to the detection limit raised observably and the sensitivity near the sample surface increased. (authors)

Technology transfer of large aggregate mix base [LAMBS] on Johannesburg roads.

CSIR Research Space (South Africa)

Horak, E

1994-10-01

Full Text Available [LAMBS] for which new mix design procedures had been developed. An early focus of this research was the constructability issues associated with this road building material. The superior performance of LAMBS was validated by means of accelerated road tests...

Horse grazing systems: understory biomass and plant biodiversity of a Pinus radiata stand

Directory of Open Access Journals (Sweden)

Antonio Rigueiro-Rodríguez

2012-02-01

Full Text Available Horse grazing systems may affect productivity and biodiversity of understory developed under Pinus radiata D. Don silvopastoral systems, while acting as a tool to reduce the risk of fire. This study compared continuous and rotational grazing systems effect upon biomass, fractions of stem, sprouts, leaves and woody parts of Ulex europaeus L. and alpha (Species Richness, Shannon-Wiener and beta (Jaccard and Magurran biodiversity for a period of four years in a P. radiata silvopastoral system. The experiment consisted of a randomized block design of two treatments (continuous and rotational grazing. Biomass, and species abundances were measured - biodiversity metrics were calculated based on these results for a two years of grazing and two years of post-grazing periods. Both continuous and rotational grazing systems were useful tools for reducing biomass and, therefore, fire risk. The rotational grazing system caused damage to the U. europaeus shrub, limiting its recovery once grazing was stopped. However, the more intensive grazing of U. europaeus plants under rotational had a positive effect on both alpha and beta biodiversity indexes due to the low capacity of food selection in the whole plot rather than continuous grazing systems. Biomass was not affected by the grazing system; however the rotational grazing system is more appropriate to reduce U. europaeus biomass and therefore forest fire risk at a long term and to enhance pasture biodiversity than the continuous grazing system.

Assessment of noise environment during construction of a major bridge and associated approach road.

Science.gov (United States)

Roy, T K; Mukhopadhyay, A R; Ghosh, S K; Majumder, G

2011-10-01

In this paper a methodology to quantify the noise environment, during a major bridge construction and upgrading approach road connectivity, has been provided. Noise levels were monitored at eleven sites. These eleven sites have been classified into three categories - commercial, residential and silence zones. The study was carried out to measure the ambient noise levels in all the eleven sites falling in the above three categories during both day and night times considering both "working" and "non-working" days. It was found that the mean noise level during night time was more, compared to that during day time for commercial, residential as well as silence zones. The likely causes of more noise during night time have been explored. Appropriate remedial measures have been suggested to reduce the noise levels. In addition, the noise levels in the above three zones have been compared, wherever feasible statistically, with the respective zonal standards. Significance has been found in all the cases. The underlying causes and remedies have been provided.

Grass species selection patterns on rotationally-grazed Dohne ...

African Journals Online (AJOL)

Herbaceous species preference was studied during autumn and winter periods of occupation, on rotationally-grazed Dohne Sourveld, at four different stocking rates. Reports on species selection by cattle and sheep grazing together. Illustrates with graphsLanguage: English. Keywords: Grass species; Herbage availibility; ...

Land use/Land Cover Changes and Causes of Deforestation in the ...

African Journals Online (AJOL)

ADOWIE PERE

2015-09-04

Sep 4, 2015 ... The semi – Automatic Classification Plugin Version 4.9.1 of the QGIS was used for the land use/land ... logging, grazing, urbanisation, road construction and ... environment. The most dramatic impact is loss of habitat for millions of species with serious implication for eco – tourism and loss of biodiversity.

Performance and Grazing Pattern of West African Dwarf Sheep to ...

African Journals Online (AJOL)

Sixty (60) West African Dwarf sheep managed semi intensively and grazing on natural pastures were used in a study to determine the performance and grazing pattern to seasonal forage supply and quality. The animals were allowed to graze for about 6 hours daily for four months each in the dry and wet seasons, ...

Large roads reduce bat activity across multiple species.

Science.gov (United States)

Kitzes, Justin; Merenlender, Adina

2014-01-01

Although the negative impacts of roads on many terrestrial vertebrate and bird populations are well documented, there have been few studies of the road ecology of bats. To examine the effects of large roads on bat populations, we used acoustic recorders to survey bat activity along ten 300 m transects bordering three large highways in northern California, applying a newly developed statistical classifier to identify recorded calls to the species level. Nightly counts of bat passes were analyzed with generalized linear mixed models to determine the relationship between bat activity and distance from a road. Total bat activity recorded at points adjacent to roads was found to be approximately one-half the level observed at 300 m. Statistically significant road effects were also found for the Brazilian free-tailed bat (Tadarida brasiliensis), big brown bat (Eptesicus fuscus), hoary bat (Lasiurus cinereus), and silver-haired bat (Lasionycteris noctivagans). The road effect was found to be temperature dependent, with hot days both increasing total activity at night and reducing the difference between activity levels near and far from roads. These results suggest that the environmental impacts of road construction may include degradation of bat habitat and that mitigation activities for this habitat loss may be necessary to protect bat populations.

Effects of past and present livestock grazing on herpetofauna in a landscape-scale experiment.

Science.gov (United States)

Kay, Geoffrey M; Mortelliti, Alessio; Tulloch, Ayesha; Barton, Philip; Florance, Daniel; Cunningham, Saul A; Lindenmayer, David B

2017-04-01

Livestock grazing is the most widespread land use on Earth and can have negative effects on biodiversity. Yet, many of the mechanisms by which grazing leads to changes in biodiversity remain unresolved. One reason is that conventional grazing studies often target broad treatments rather than specific parameters of grazing (e.g., intensity, duration, and frequency) or fail to account for historical grazing effects. We conducted a landscape-scale replicated grazing experiment (15,000 km 2 , 97 sites) to examine the impact of past grazing management and current grazing regimes (intensity, duration, and frequency) on a community of ground-dwelling herpetofauna (39 species). We analyzed community variables (species richness and composition) for all species and built multiseason patch-occupancy models to predict local colonization and extinction for the 7 most abundant species. Past grazing practices did not influence community richness but did affect community composition and patch colonization and extinction for 4 of 7 species. Present grazing parameters did not influence community richness or composition, but 6 of the 7 target species were affected by at least one grazing parameter. Grazing frequency had the most consistent influence, positively affecting 3 of 7 species (increased colonization or decreased extinction). Past grazing practice affected community composition and population dynamics in some species in different ways, which suggests that conservation planners should examine the different grazing histories of an area. Species responded differently to specific current grazing practices; thus, incentive programs that apply a diversity of approaches rather than focusing on a change such as reduced grazing intensity should be considered. Based on our findings, we suggest that determining fine-scale grazing attributes is essential for advancing grazing as a conservation strategy. © 2016 Society for Conservation Biology.

Response of moose to a high‐density road network

Science.gov (United States)

Wattles, David W.; Zeller, Katherine A.; DeStefano, Stephen

2018-01-01

Road networks and the disturbance associated with vehicle traffic alter animal behavior, movements, and habitat selection. The response of moose (Alces americanus) to roads has been documented in relatively rural areas, but less is known about moose response to roads in more highly roaded landscapes. We examined road‐crossing frequencies and habitat use of global positioning system (GPS)‐collared moose in Massachusetts, USA, where moose home ranges have road densities approximately twice that of previous studies. We compared seasonal road‐crossing frequencies of moose with a null movement model. We estimated moose travel speeds during road‐crossing events and compared them with speeds during other home range movements. To estimate the extent of the road effect zone and determine how roads influenced moose habitat use, we fit a third‐order resource selection function. With the exception of the lowest use road class (roads less than expected based on the null movement model and frequency decreased with increasing road size and traffic. Moose crossed roads faster than they traveled during other times. This effect increased with increasing road use intensity. Overall, roads were a major factor determining what portions of Massachusetts moose used and how they moved among habitat patches. Our results suggest that moose in Massachusetts can adapt to a high‐density road network, but the road effect is still strongly negative and, in some cases, is more pronounced than in study areas with lower road densities. Future road construction and the expansion of road networks may have a large effect on moose and other wildlife.

Geotextiles in Flexible Pavement Construction

Science.gov (United States)

Alungbe, Gabriel D.

2004-01-01

People everywhere in the developed world regularly drive on paved roads. Learning about the construction techniques and materials used in paving benefits technology and construction students. This article discusses the use of geosynthetic textiles in pavement construction. It presents background on pavements and describes geotextiles and drainage…

An introduction to the integrated design of surface mine haul roads

Energy Technology Data Exchange (ETDEWEB)

Thompson, R.J.; Visser, A.T. [University of Pretoria, Pretoria (South Africa). Dept. of Mining Engineering

1997-12-01

The world-wide expansion of surface mining has led to the development of very large off-highway trucks currently capable of hauling layloads in excess of 160 t. Typical axle loads ranging from 110 t to 170 t are applied to haul roads that have been, at best, empirically designed on the premise of `satisfactory` or `failed`, both in terms of structure and function of the road. The use of these empirical pavement design techniques will prove inadequate when high axle loads are encountered. Not only will the maintenance costs of existing haul roads of inadequate thickness increase, but vehicle operating and maintenance costs will also increase prohibitively. Under these conditions there is thus a clearly defined need for improved construction and management techniques for flexible mine haulage roads, appropriate for the wheel loads of vehicles now in use. The aim of this paper is to introduce developments in haul road structural, functional and maintenance design and management which overcome the limitations associated with the previously empirical design techniques and to show how these developments are combined into an integrated design strategy combining construction techniques, available material and road maintenance equipment with hauler choice to realise a reduction in haulage and road maintenance costs. Future contributions will enumerate on the fundamental haul road structural, functional and maintenance design and management research from which these developments originated. 7 refs., 5 figs., 2 tabs.

Road traffic crashes and risk groups in India: Analysis, interpretations, and prevention strategies

Directory of Open Access Journals (Sweden)

Raj V. Ponnaluri

2012-03-01

Recommended prevention strategies include: developing a road accident recording system and an access management policy; integrating safety into corridor design and road construction; undertaking capacity-building efforts; and expanding emergency response services.

Products based on the mixes of fly ashes and fibre sludge (fibre-ashes) for road construction; Produkter baserade paa blandningar av flygaska och fiberslam (fiberaskor) foer vaegbyggande

Energy Technology Data Exchange (ETDEWEB)

Lahtinen, Pentti; Maijala Aino; Macsik, Josef

2005-03-01

The project has derived benefits from the earlier Finnish research and development as well as from the experience in the fibre-ash materials for geotechnical applications. The fly ashes used for the project have been taken from the same sources as the fly ashes for the earlier Vaermeforsk project 870: FACE. The project's objective was to develop construction materials based on mixtures of fibre sludge and fly ash for geotechnical applications, and for the final commercialisation of the fibre-ash materials. The mixtures are based on fly ashes from energy production (bark, peat and sludge used for incineration) and on kaolin containing fibre sludge from the paper industry. With help of laboratory tests the project has been searching for fibre ashes with excellent technical characteristics like good frost resistance combined with a good bearing capacity and resilience in geotechnical structures. The project's results has given additional knowledge about alternative road construction materials to construct technically good, sustainable and environmentally friendly roads and other constructions with lower costs than the conventional constructions. The results of laboratory tests have shown that this is possible. However, it has to be verified with help of field tests and pilot constructions. The first tasks of the project were to make choices of the appropriate fibre sludge and fly ashes for the project targets. The laboratory tests have been carried out in the geotechnical laboratory of Ramboll Finland Oy (earlier SCC Viatek Oy, SGT - later in the report SGT). After arrival of all test material in the laboratory the test programme started in order to find out the most optimal fibre-ash mixtures with or without any activator. The most potential mixtures were tested for their geotechnical long-term properties (mainly resistance against climatic load) and for their environmental risk potential. The results comprise of several technically, environmentally and

Forage patch use by grazing herbivores in a South African grazing ecosystem

NARCIS (Netherlands)

Venter, J.A.; Nabe-Nielsen, J.; Prins, H.H.T.; Slotow, R.

2014-01-01

Understanding how different herbivores make forage patch use choices explains how they maintain an adequate nutritional status, which is important for effective conservation management of grazing ecosystems. Using telemetry data, we investigated nonruminant zebra (Equus burchelli) and ruminant red

Livestock grazing and the desert tortoise in the Mojave Desert

Science.gov (United States)

Oldemeyer, John L.

1994-01-01

A large part of the Mojave Desert is not in pristine condition, and some current conditions can be related to past grazing-management practices. No information could be found on densities of the desert tortoise (Gopherus agassizii) or on vegetative conditions of areas that had not been grazed to allow managers a comparison of range conditions with data on tortoises. Experimental information to assess the effect of livestock grazing on tortoises is lacking, and researchers have not yet examined whether the forage that remains after grazing is sufficient to meet the nutritional needs of desert tortoises.

Evaluation of primary DNA damage, cytogenetic biomarkers and genetic polymorphisms for CYP1A1 and GSTM1 in road tunnel construction workers.

Science.gov (United States)

Villarini, M; Moretti, M; Fatigoni, C; Agea, E; Dominici, L; Mattioli, A; Volpi, R; Pasquini, R

2008-01-01

In tunnel construction workers, occupational exposure to dust (alpha-quartz and other particles from blasting), gases (nitrogen dioxide, NO(2)), diesel exhausts, and oil mist has been associated with lung function decline, induction of inflammatory reactions in the lungs with release of mediators that may influence blood coagulation, and increased risk of chronic obstructive pulmonary disease. The present molecular epidemiology study was designed to evaluate whether occupational exposure to indoor pollutants during road tunnel construction might result in genotoxic effects. A study group of 39 underground workers and a reference group of 34 unexposed subjects were examined. Primary and oxidative DNA damage, sister-chromatid exchanges (SCE), and micronuclei (MN) were measured in peripheral blood cells. The possible influences of polymorphisms in gene encoding for CYP1A1 and GSTM1 xenobiotic-metabolizing enzymes were also investigated. Exposure assessment was performed with detailed interviews and questionnaires. There were no significant differences in the level of primary and oxidative DNA damage and frequency of SCE between the tunnel workers and controls, whereas the frequency of MN showed a significant increase in exposed subjects compared to controls. No effects of CYP1A1 or GSTM1 variants were observed for the analyzed biomarkers. Since MN in peripheral blood lymphocytes are recognized as a predictive biomarker of cancer risk within a population of healthy subjects, the genotoxic risk of occupational exposure to various indoor environmental pollutants during road tunnel construction cannot be excluded by this biomonitoring study.

Review: Behavior and daily grazing patterns of cattle

NARCIS (Netherlands)

Gregorini, P.; Tamminga, S.; Gunther, S.A.

2006-01-01

Grazing ruminants consume their food in discrete grazing events. The frequency and distribution of these events depend on the current physiological state of the animal and its environment. Within a small spatio-temporal scale, foraging decisions such as when to begin, which frequency, and how to

Dynamics of forage accumulation in Elephant grass subjected to rotational grazing intensities

Directory of Open Access Journals (Sweden)

Braulio Maia de Lana Sousa

2013-09-01

Full Text Available We assessed the accumulation dynamics of forage and its components in Elephant grass cv. Napier (Pennisetum purpureum Schum. that were subjected to three post-grazing height treatments (30, 50, and 70 cm from February through May 2009 (experiment one and December 2009 through May 2010 (experiment two. In experiment one, the grazing events started when the light interception by the canopy reached 95%. The same was adopted for experiment two, except for the first grazing event, which was based on the height of the apical meristems of basal tillers. The experimental design for both experiments was a randomized complete block with three replications. The pastures that were managed at a post-grazing height of 30 cm exhibited lower rates of leaf and stem growth, total growth and forage accumulation than those that were managed at 50 or 70 cm, indicating that post-grazing height affects Elephant grass. The pastures that were managed at 50 cm exhibited relatively stable accumulation rates and less stem accumulation. Pastures managed at 70 cm of pos-grazing height presented more leaf and stem accumulation. Most apical meristems of Elephant grass should be removed in the first grazing when they reach the post-grazing target height of 50 cm. The elevation in the residual post-grazing height, especially in the summer, raises the regrowth vigor in the Elephant grass cv. Napier pasture. The post-grazing height of 30 cm reduces the growth of the Elephant grass cv. Napier.

Grazing livestock are exposed to terrestrial cyanobacteria.

Science.gov (United States)

McGorum, Bruce C; Pirie, R Scott; Glendinning, Laura; McLachlan, Gerry; Metcalf, James S; Banack, Sandra A; Cox, Paul A; Codd, Geoffrey A

2015-02-25

While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in all samples tested, including 6 plant washings, 1 soil sample and ileal contents from 2 grazing horses. Further work was performed to test the hypothesis that ingestion of cyanotoxins contributes to the pathogenesis of some currently unexplained diseases of grazing horses, including equine grass sickness (EGS), equine motor neuron disease (EMND) and hepatopathy. Phormidium population density was significantly higher on EGS fields than on control fields. The cyanobacterial neurotoxic amino acid 2,4-diaminobutyric acid (DAB) was detected in plant washings from EGS fields, but worst case scenario estimations suggested the dose would be insufficient to cause disease. Neither DAB nor the cyanobacterial neurotoxins β-N-methylamino-L-alanine and N-(2-aminoethyl) glycine were detected in neural tissue from 6 EGS horses, 2 EMND horses and 7 control horses. Phormidium was present in low numbers on plants where horses had unexplained hepatopathy. This study did not yield evidence linking known cyanotoxins with disease in grazing horses. However, further study is warranted to identify and quantify toxins produced by cyanobacteria on livestock fields, and determine whether, under appropriate conditions, known or unknown cyanotoxins contribute to currently unexplained diseases in grazing livestock.

Road and railway network of the Paks nuclear power plant, Hungary

International Nuclear Information System (INIS)

Szoukup, I.; Komlos, Cs.

1983-01-01

Meeting the demands of reception, unloading and transportation of materials during the construction and later, during the operation of the plant, is ensured by a suitable road and railway network. The tasks of internal roads and tracks, their connection with the national transportation network are presented. (author)

Afghanistan’s Road Infrastructure: Sustainment Challenges and Lack of Repairs Put U.S. Investment at Risk

Science.gov (United States)

2016-10-01

requires the MOF to collect the fuel tax revenue and place it into a special account and transfer the funds to the MOPW for road maintenance...objectives of this audit were to determine the extent to which (1) U.S. agencies have fully accounted for the road construction they funded in...335 million for short-term employment programs, including road construction, in support of counterinsurgency efforts. Although USAID could account

Road roughness evaluation using in-pavement strain sensors

Science.gov (United States)

Zhang, Zhiming; Deng, Fodan; Huang, Ying; Bridgelall, Raj

2015-11-01

The international roughness index (IRI) is a characterization of road roughness or ride quality that transportation agencies most often report. The prevalent method of acquiring IRI data requires instrumented vehicles and technicians with specialized training to interpret the results. The extensive labor and high cost requirements associated with the existing approaches limit data collection to at most once per year for portions of the national highway system. Agencies characterize roughness only for some secondary roads but much less frequently, such as once every five years, resulting in outdated roughness information. This research developed a real-time roughness evaluation approach that links the output of durable in-pavement strain sensors to prevailing indices that summarize road roughness. Field experiments validated the high consistency of the approach by showing that it is within 3.3% of relative IRI estimates. After their installation and calibration during road construction, the ruggedized strain sensors will report road roughness continuously. Thus, the solution will provide agencies a real-time roughness monitoring solution over the remaining service life of road assets.

Environmental sensitive road planning and transportation techniques in forest engineering

Directory of Open Access Journals (Sweden)

H. Hulusi Acar

2016-07-01

Full Text Available Forestry management has activities dealing with technical, economic, social and environmental services. Forestry operations which are carried out on forest areas , an important part of the ecosistem are materialized in open space. This forestry activities on large areas and high sloping generally, include many different techniques. It is needed primarily to the forest road network in terms of forest management. Determining the approriate route in the natural environment, planning and road construction affairs for forest roads which are necessary accessing in forest areas, is also of great importance from an environmental viewpoint as well as technical and economic manner. Forest road planning which can not be changed later and left a permanent mark on the natural environment carries much more importance to the environment especially on sloping land. This is because, it is important choosing correct type of roaf structure, and doing periodic maintenance of the roads. Skidding activities, after wood production, is important in terms of its impact on forest soil and by means of effects on saplings and trees on the releated forest areas.The development of environmental sensitive techniques is difficult, limited or expensive for this wood extraction works which are made more difficult conditons in the sloping terrain. Therefore, especially in using some silvicultural methods wood extraction damages are even greater. In this study; some road planning, road construction and wood extraction techniques which performed by me have been made to examine the environmental aspects. Environment-friendly forest roads and primary transport techniques on the forest ecosystem are briefly explained and discussed in the frame of the environmental aspects.

The road to development : the construction and use of 'the Great North Road' in Gold Coast Ghana

NARCIS (Netherlands)

Ntewusu, S.A.

2014-01-01

This article is a historical study of a 'motor road' linking the north of the Gold Coast (present day Ghana) to the South. Historians concerned with routes and trade in nineteenth century Gold Coast usually end their accounts at the onset of colonial rule. While studies that concentrate on transport

A decision algorithm for determining safe clearing limits for the construction of skid roads

Science.gov (United States)

Chris LeDoux

2006-01-01

The majority of the timber harvested in the United States is extracted by ground-based skidders and crawler/dozer systems. Ground-based systems generally require a primary transportation network (a network of skid trails/roads) throughout the area being harvested. Logs are skidded or dragged along these skid roads/trails as they are transported from where they were cut...

Grazing reduces soil greenhouse gas fluxes in global grasslands: a meta-analysis

Science.gov (United States)

Tang, Shiming; Tian, Dashuan; Niu, Shuli

2017-04-01

Grazing causes a worldwide degradation in grassland and likely alters soil greenhouse gas fluxes (GHGs). However, the general patterns of grazing-induced changes in grassland soil GHGs and the underlying mechanisms remain unclear. Thus, we synthesized 63 independent experiments in global grasslands that examined grazing impacts on soil GHGs (CO2, CH4 and N2O). We found that grazing with light or moderate intensity did not significantly influence soil GHGs, but consistently depressed them under heavy grazing, reducing CO2 emission by 10.55%, CH4 uptake by 19.24% and N2O emission by 28.04%. The reduction in soil CO2 was mainly due to decreased activity in roots and microbes (soil respiration per unit root and microbial biomass), which was suppressed by less water availability due to higher soil temperature induced by lower community cover under heavy grazing. N2O emission decreased with grazing-caused decline in soil total N. The inhibitory effect on methanotroph activities by water stress is responsible for the decreased CH4 uptake. Furthermore, grazing duration and precipitation also influenced the direction and magnitude of responses in GHGs fluxes. Overall, our results indicate that the reduction in soil CO2 and N2O emission under heavy grazing is partially compensated by the decrease in CH4 uptake, which is mainly regulated by variations in soil moisture.

Population Dynamics and Transcriptomic Responses of Chorthippus albonemus (Orthoptera: Acrididae to Herbivore Grazing Intensity

Directory of Open Access Journals (Sweden)

Xinghu Qin

2017-11-01

Full Text Available Livestock grazing can trigger outbreaks of insect pests in steppe ecosystems of Inner Mongolia in China. However, the physiological responses of the grasshopper Chorthippus albonemus to grazing are not well-understood. Here we investigated the effects of sheep grazing on the population dynamics and transcriptomic response of C. albonemus. We collected the insects three times (about 20 days apart in 1.33-ha plots in which there were no grazing, light grazing, moderate grazing, heavy grazing, or overgrazing. Our results showed that continuous grazing significantly decreased plant biomass and influenced plant succession. Total insect species diversity significantly declined along the grazing intensity gradient and over time. Results of the first two collections of C. albonemus indicated that moderate grazing significantly increased the abundance of C. albonemus. However, abundance was significantly decreased in plots that were overgrazed, possibly because of food stress and environmental pressures. Under moderate grazing, betA and CHDH genes were significantly upregulated in C. albonemus. In response to higher grazing intensity, upregulated genes included those involved in serine-type peptidase activity, anatomical structure development, and sensory organ development; downregulated genes included those involved in the structural constituents of the ribosome and ribosome processes. Genes strongly upregulated in response to heavy grazing pressure included adaptive genes such as those encoding ankyrin repeat domain-containing protein and HSP. These findings improve our understanding of the role of the transcriptome in C. albonemus population response to livestock grazing and may provide useful targets for grasshopper control.

Reproductive performance of ewes grazing lucerne during different periods around mating.

Science.gov (United States)

Robertson, S M; Clayton, E H; Friend, M A

2015-11-01

High intake of lucerne pastures or feeding of other high quality diets during early pregnancy may increase embryo mortality, negating any benefit of improved nutrition on ovulation rate in ewes. This study was conducted to determine whether grazing ewes on lucerne (Medicago sativa) pastures for 7 days prior to and throughout joining would result in greater foetal numbers than if ewes were removed 7 days after the commencement of joining, or if ewes grazed senescent pasture throughout the joining period. Merino ewes (300) were allocated to two replicates of three treatments, grazing pastures between Days -7 and 36 of an unsynchronised, natural autumn joining. Grazing lucerne to Day 7 of joining resulted in 30% more (Pewe than grazing senescent pasture (1.60±0.07 and 1.31±0.07, respectively), and 19% more lambs marked per ewe joined. Extending grazing of lucerne past Day 7 of joining did not result in additional foetuses per ewe (1.61±0.06) in comparison with only grazing lucerne to Day 7 of joining. Greater than 80% of ewes mated during the first 14 days of joining, and the proportions of ewes returning to oestrus and re-mating (0.18±0.022) and of non-pregnant (0.09±0.017) ewes were similar (P>0.05) among all treatment groups, suggesting no differences between treatments in embryo mortality. Grazing naturally cycling ewes on lucerne prior to and during joinings in autumn is recommended as a means to increase the number of lambs born, although additional gains may not be obtained by grazing past day seven of joining. Copyright © 2015 Elsevier B.V. All rights reserved.

Recent developments and current policy issues in road pricing in the US and Canada

OpenAIRE

Lindsey, Robin

2005-01-01

The United States and Canada lag Europe and Singapore in implementing road pricing on a large scale. But the two countries have shown interest in tolling roads as a way to curb congestion and to generate revenues. The US is funding congestion pricing demonstration projects through its Value Pricing Pilot Program, and Canada has examined new ways to charge for road use and to finance road construction and maintenance. This paper reviews the current state of road pricing and funding...

IRI performance models for recently constructed low and medium-traffic two lane roads of the province of Biscay

Energy Technology Data Exchange (ETDEWEB)

Perez Acebo, H.; Gonzalo-Orden, H.

2016-07-01

Reliable pavement prediction models are needed for pavement management systems (PMS), as they are a key component to forecast future conditions of the pavement and to prioritize maintenance, rehabilitation and reconstruction strategies. The International Roughness Index (IRI) is the most used parameter worldwide for calibrating pavement roughness and measures reasonably the ride comfort perceived by occupants of passenger cars. The Regional Government of Biscay also collects this value on the road network under its control These surveys are carried out regularly in the XXI century. Several IRI performance models have been proposed by different authors and administrations, varying greatly in their comprehensiveness, the ability to predict performance with accurancy and input data requirements. The aim of this paper is to develop a roughness performance model for Biscay's roads, based on availablbe IRI data, taking into account heavy traffic volume and the age of pavement. Local characteristics as climate conditions and average rainfall are not considered. IRI performance models have been suggested for regional two lane highways with low and medium heavy traffic constructed in the last 20 years in the province of Biscay, with no treatments during their life. They can be applied for flexible pavements, but no logical coherent results have been concluded for semi-rigid pavements. (Author)

The Effects of Timing of Grazing on Plant and Arthropod Communities in High-Elevation Grasslands

Science.gov (United States)

Davis, Stacy C.; Burkle, Laura A.; Cross, Wyatt F.; Cutting, Kyle A.

2014-01-01

Livestock grazing can be used as a key management tool for maintaining healthy ecosystems. However, the effectiveness of using grazing to modify habitat for species of conservation concern depends on how the grazing regime is implemented. Timing of grazing is one grazing regime component that is less understood than grazing intensity and grazer identity, but is predicted to have important implications for plant and higher trophic level responses. We experimentally assessed how timing of cattle grazing affected plant and arthropod communities in high-elevation grasslands of southwest Montana to better evaluate its use as a tool for multi-trophic level management. We manipulated timing of grazing, with one grazing treatment beginning in mid-June and the other in mid-July, in two experiments conducted in different grassland habitat types (i.e., wet meadow and upland) in 2011 and 2012. In the upland grassland experiment, we found that both early and late grazing treatments reduced forb biomass, whereas graminoid biomass was only reduced with late grazing. Grazing earlier in the growing season versus later did not result in greater recovery of graminoid or forb biomass as expected. In addition, the density of the most ubiquitous grassland arthropod order (Hemiptera) was reduced by both grazing treatments in upland grasslands. A comparison of end-of-season plant responses to grazing in upland versus wet meadow grasslands revealed that grazing reduced graminoid biomass in the wet meadow and forb biomass in the upland, irrespective of timing of grazing. Both grazing treatments also reduced end-of-season total arthropod and Hemiptera densities and Hemiptera biomass in both grassland habitat types. Our results indicate that both early and late season herbivory affect many plant and arthropod characteristics in a similar manner, but grazing earlier may negatively impact species of conservation concern requiring forage earlier in the growing season. PMID:25338008

Impact of Graze-­‐Out in Hard Red Winter Wheat Production

OpenAIRE

Neupane, Diwash; Moss, Charles B.

2014-01-01

We investigate the relationship between wheat graze-­‐out and cattle-­‐wheat price ratio and moisture level and examine the impact of graze-­‐out on wheat yield in major wheat-­‐producing states in US. Results indicate that cattle-­‐wheat price ratio and moisture level affect farmers’ graze out decision and graze-­‐out have significant impact on wheat yield.

The road safety audit and road safety inspection.

NARCIS (Netherlands)

2007-01-01

A road safety audit (RSA) and a road safety inspection (RSI) are used to test the safety level of the road infrastructure. The RSA tests the design of new roads or the reconstruction of existing roads, whereas the RSI is used for testing existing roads. An RSA, therefore, aims to 'improve' the road

36 CFR 222.53 - Grazing fees in the East-noncompetitive procedures.

Science.gov (United States)

2010-07-01

... lands and the total costs (other than grazing fee costs) of operating on National Forest System lands... the percentage change in the cost of alternative livestock feed. (3) Computation of Annual Grazing Fee... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Grazing fees in the East...

Effects of Grazing Abandoned Grassland on Herbage Production and Utilization, and Sheep Preference and Performance

Directory of Open Access Journals (Sweden)

Håvard Steinshamn

2018-05-01

Full Text Available Large areas of farmland are abandoned in Norway, which for various reasons are regarded as undesirable. Loss of farmland may have negative implications for biodiversity and ecosystem function and food production potential. The objectives of this study were to assess forage mass production and utilization, botanical composition, lamb performance, and grazing distribution pattern when reintroducing livestock grazing to an abandoned grassland. The study area was located in Central Norway, unmanaged for 12 years. Sheep grazed the area for 10 weeks in 2013 and 4 weeks in spring and autumn, respectively, in 2014 and 2015. During the summer of 2014 and 2015, the area was subjected to the following replicated treatments: (1 No grazing, (2 grazing with heifers, and (3 grazing with ewes and their offspring. The stocking rate was similar in the grazed treatments. Forage biomass production and animal intake were estimated using grazing exclosure cages and botanical composition by visual assessment. Effect on lamb performance was evaluated by live weight gain and slaughter traits in sheep subjected to three treatments: (1 Common farm procedure with summer range pasturing, (2 spring grazing period extended by 1 month on the abandoned grassland before summer range pasturing, and (3 spring and summer grazing on the abandoned grassland. Grazing distribution patterns were studied using GPS position collars on ewes. Total annual biomass production was on average 72% higher with summer grazing than without. Annual consumption and utilization was on average 218 g DM/m2 and 70% when summer grazed, and 25 g DM/m2 and 18% without grazing, respectively. Botanical composition did not differ between treatments. Live weight gain was higher in lambs subjected to an extended spring grazing period (255 g/d compared to common farm practice (228 g/d and spring and summer grazing on the abandoned grassland (203 g/d, and carcass value was 14% higher in lambs on extended spring

Development in techniques for studying forest roads on peatlands

International Nuclear Information System (INIS)

Saarilahti, M.

1988-01-01

A light seismic method, a short-pulse radar and a microwave probe are tested in assessing the properties of a forest road constructed on peatland. The light seismic method gave reliable values for estimating the bearing capacity of the road. It was found that bearing capacity was mostly dependent on embankment thickness, but quality of labric might also have an influence. Embankment thickness and peat depth can be measured on the radargram, and some additional information on road bed and peat obtained. The microwave peat probe permits recording of the continuous moisture profile in situ, which improves accuracy of planning

Development in techniques for studying forest roads on peatlands

Energy Technology Data Exchange (ETDEWEB)

Saarilahti, M.

1988-07-01

A light seismic method, a short-pulse radar and a microwave probe are tested in assessing the properties of a forest road constructed on peatland. The light seismic method gave reliable values for estimating the bearing capacity of the road. It was found that bearing capacity was mostly dependent on embankment thickness, but quality of labric might also have an influence. Embankment thickness and peat depth can be measured on the radargram, and some additional information on road bed and peat obtained. The microwave peat probe permits recording of the continuous moisture profile in situ, which improves accuracy of planning.

Sustainable use of oil sands for geotechnical construction and road building

CSIR Research Space (South Africa)

Anochie-Boateng, Joseph

2012-02-01

Full Text Available Oil sands are natural deposits of bituminous sand materials that are mined and processed for crude oil. They are routinely used in oil sand fields for building temporary and sometimes permanent roads serving mining and hauling activities. Although...

Scaling roads and wildlife: The Cinderella principle

Science.gov (United States)

Bissonette, J.A.

2002-01-01

It is clear that a reduction in both direct and indirect effects of roads and road networks must be the goal of management agencies. However, increased permeability of roaded landscapes can only be achieved by up-front planning and subsequent mitigative actions. The key is to understand that roads must be made permeable to the movement of animals. More profoundly, ecosystem services, i.e., clean water, clean air, uncontaminated soil, natural landscapes, recreation opportunities, abundant wildlife, and life sustaining ecological processes must not be seriously impacted. In other words, quality of life as measured by ecosystem services should be a major component of the planning process when roads are constructed or improved. Mitigative structures exist to increase permeability of roads. Wildlife overpasses and underpasses, often referred to as ecoducts or green bridges, with associated structures to enable larger animals to exit the road right of way, e.g., earthen escape ramps (BISSONETTE and HAMMER, 2001), various culvert designs for smaller animals including badger pipes and amphibian and reptile tunnels, and fish ladders are but a small sampling of the structures already in place around the world. What is needed is attention to the big picture. Landscapes need to be reconnected and made more permeable. Responsible agencies and organizations need to be aggressive about promoting mitigations and a conservation ethic into road planning. Only with a broad based effort between a concerned public, a database to work from, and a willingness of responsible agencies, will the now very large virtual footprint of roads and road networks be reduced to more closely approximate the physical footprint. By embracing the Cinderella Principle of making the virtual shoe fit more closely the actual physical footprint of roads, we will be able to achieve a closer connection with ecological harmony with its resultant effect of abundant wildlife.

Radioactive materials in construction projects

International Nuclear Information System (INIS)

Herrmann, Ralf; Ohlendorf, Frank; Kaltz, Andrea Christine

2014-01-01

Till 1990 residues often of the former uranium mining were partly used as building material for road construction, terrain compensation and house construction in Saxony. These recommendations for action are addressed to applicants, planners and building constructors in the engineering and construction sector. It provides information for planning, preliminary investigations, applications, construction supervision related to radiation protection measures and documentation of construction projects where radioactive materials are expected.

Grazing preference and utilization of soil fungi by Folsomia candida (Collembola)

Science.gov (United States)

Hedenec, Petr; Frouz, Jan

2016-04-01

Soil fungi are important food resources for soil fauna. Here we ask whether the collembolan Folsomia candida shows selectivity in grazing between four saprophytic fungi (Penicillium chrysogenum, Penicillium expansum, Absidia glauca, and Cladosporium herbarum), whether grazing preference corresponds to effects on collembolan reproduction, and whether the effects of fungi on grazing and reproduction depends on the fungal substrate, which included three kinds of litter (Alnus glutinosa, Salix caprea, and Quercus robur) and one kind of agar (yeast extract). On agar, Cladosporium herbarum and Absidia glauca were the most preferred fungi and supported the highest collembolan reproduction. On fungal-colonized litter, grazing preference was more affected by litter type than by fungal species whereas collembolan reproduction was affected by both litter type and fungal species. On fungal-colonized litter, the litter type that was most preferred for grazing did not support the highest reproduction, i.e., there was an inconsistency between food preference and suitability. Alder and willow were preferred over oak for grazing, but alder supported the least reproduction.

User costs as one of main advantages of precast concrete application in highway construction

Science.gov (United States)

Tomek, Radan

2017-09-01

Road user cost primarily refer to the monetized components of road (re)construction impacts, such as the user delay costs, vehicle operating costs, crash costs and emission costs. Objective of this paper is to analyze and appraise the advantages and benefits of the innovative prefabrication approach in contrast to traditional cast-in-place construction method. The goal is to reduce these additional costs borne by motorists and the community at-large as a result of road construction activity to their minimum through application of the prefabrication. Assessing two basic possible approaches to highway infrastructure construction - casting the road pavements and structures either in place or precast off the site - it can be concluded that the initial capital investment costs do not vary much. Substantial differences can be recognized when comparing their life-cycle costs and an extent to which their construction process affects the public, environment and the local economy. Prefabrication of any structure component off-site offers major construction time and user cost savings in comparison with the traditional cast-in-place methods of construction. Precast prestressed road pavements’ technology and precasting bridges’ parts and elements offers dramatic increase in durability, while it also substantially decreases construction time and resulting user costs.

Quarry Haul Road Ecological Survey

International Nuclear Information System (INIS)

1992-09-01

This biological survey was performed to document the summer flora and fauna found along the haul road constructed as part of the remedial action for the quarry bulk waste. State and Federal species listed as threatened or endangered were noted if encountered while surveying. Sampling locations were equally spaced along the quarry haul road, and a survey for vegetation and birds conducted at each location. Bird observations were conducted as breeding bird surveys once in June of 1991, and again in June of 1992. Each year's survey includes two observations in the early morning and one late in the evening. Vegetation surveys were conducted in 1991 using quadrants and transects. mammal, reptile, and amphibian sightings were noted as encountered

Building lunar roads - An overview

Science.gov (United States)

Rutledge, Bennett

The problems involved in constructing lunar roads are explored. The main challenges are airlessness, low gravity, and solar effects, especially temperature extremes. Also involved are the expense of delivering equipment and material to the job site (especially for bridges and other structures), obtaining skilled labor, and providing maintenance. The lunar road will most likely be gravel, but with the size of the material closer to cobblestone to reduce scattering. They will probably be very winding, even on the flats, and feature numerous bridges and some cuts. This traffic will be mostly automatic or teleoperated cargo carriers with a handful of shirtsleeve-pressurized 'passenger cars' large enough to live in for several days.

Grazing exit versus grazing incidence geometry for x-ray absorption near edge structure analysis of arsenic traces

International Nuclear Information System (INIS)

Meirer, F.; Streli, C.; Wobrauschek, P.; Zoeger, N.; Pepponi, G.

2009-01-01

In the presented study the grazing exit x-ray fluorescence was tested for its applicability to x-ray absorption near edge structure analysis of arsenic in droplet samples. The experimental results have been compared to the findings of former analyses of the same samples using a grazing incidence (GI) setup to compare the performance of both geometries. Furthermore, the investigations were accomplished to gain a better understanding of the so called self-absorption effect, which was observed and investigated in previous studies using a GI geometry. It was suggested that a normal incidence-grazing-exit geometry would not suffer from self-absorption effects in x-ray absorption fine structure (XAFS) analysis due to the minimized path length of the incident beam through the sample. The results proved this assumption and in turn confirmed the occurrence of the self-absorption effect for GI geometry. Due to its lower sensitivity it is difficult to apply the GE geometry to XAFS analysis of trace amounts (few nanograms) of samples but the technique is well suited for the analysis of small amounts of concentrated samples

Genetic strain and diet effects on grazing behavior, pasture intake, and milk production.

Science.gov (United States)

Sheahan, A J; Kolver, E S; Roche, J R

2011-07-01

Understanding how dairy cows adjust their grazing behavior in response to feed supplements is important for the development of management strategies that optimize profit from supplementation. New Zealand Holstein-Friesian (HF) cows have been selected for milk production on a predominantly pasture-based diet; in comparison, HF cows of North American (NA) ancestry have been selected almost exclusively for milk yield and fed diets high in nonfiber carbohydrates (NFC). We hypothesized, therefore, that supplementation would have differing effects on grazing behavior, pasture dry matter intake (DMI), and milk production in these genetic strains at peak, mid, and late lactation. A study was conducted over 2 consecutive lactations, with NA and NZ cows randomly allocated at calving to 0, 3, or 6 kg of dry matter/day concentrate plus unrestricted access to pasture. Pasture DMI, milk production, and grazing behavior were recorded at peak, mid, and late lactation. Concentrates were fed in equal amounts at morning and afternoon milking. The NA cows produced more milk and milk components, and had a greater pasture DMI, despite spending less time grazing. Declines in time spent grazing and pasture DMI were associated with increasing concentrate DMI. Grazing behavior following morning supplementation was different from that recorded following afternoon supplementation. Grazing ceased following morning supplementation before rumen fill could be a limiting factor, and the length of the grazing interval was inversely proportional to the amount of concentrate offered; these results suggest that physiological rather than physical stimuli were responsible for grazing cessation. The decrease in time spent grazing with increasing concentrate DMI is consistent with changes in neuroendocrine factors secreted in response to the presence of food in the digestive tract or with circulating products of digestion. After afternoon supplementation, sunset signaled the end of grazing irrespective of

The Extraction of Road Boundary from Crowdsourcing Trajectory Using Constrained Delaunay Triangulation

Directory of Open Access Journals (Sweden)

YANG Wei

2017-02-01

Full Text Available Extraction of road boundary accurately from crowdsourcing trajectory lines is still a hard work.Therefore,this study presented a new approach to use vehicle trajectory lines to extract road boundary.Firstly, constructing constrained Delaunay triangulation within interpolated track lines to calculate road boundary descriptors using triangle edge length and Voronoi cell.Road boundary recognition model was established by integrating the two boundary descriptors.Then,based on seed polygons,a regional growing method was proposed to extract road boundary. Finally, taxi GPS traces in Beijing were used to verify the validity of the novel method, and the results also showed that our method was suitable for GPS traces with disparity density,complex road structure and different time interval.

Changes in semi-arid plant species associations along a livestock grazing gradient.

Directory of Open Access Journals (Sweden)

Hugo Saiz

Full Text Available In semi-arid ecosystems, vegetation is heterogeneously distributed, with plant species often associating in patches. These associations between species are not constant, but depend on the particular response of each species to environmental factors. Here, we investigated how plant species associations change in response to livestock grazing in a semi-arid ecosystem, Cabo de Gata-Níjar Natural Park in South East Spain. We established linear point-intercept transects at four sites with different grazing intensity, and recorded all species at each point. We investigated plant associations by comparing the number of times that each pair of species occurred at the same spatial point (co-occurrences, with the expected number of times based on species abundances. We also assessed associations for each shrub and grass species by considering all their pairs of associations and for the whole plant community by considering all pairs of associations on each site. At all sites, the plant community had a negative pattern of association, with fewer co-occurrences than expected. Negative association in the plant community increased at maximum grazing intensity. Most species associated as expected, particularly grass species, and positive associations were most important at intermediate grazing intensities. No species changed its type of association along the grazing gradient. We conclude that in the present plant community, grazing-resistant species compete among themselves and segregate in space. Some shrub species act as refuges for grazing-sensitive species that benefit from being spatially associated with shrub species, particularly at intermediate grazing intensities where positive associations were highest. At high grazing intensity, these shrubs can no longer persist and positive associations decrease due to the disappearance of refuges. Spatial associations between plant species and their response to grazing help identify the factors that organize

Predicting the effectiveness of road safety campaigns through alternative research designs.

Science.gov (United States)

Adamos, Giannis; Nathanail, Eftihia

2016-12-01

A large number of road safety communication campaigns have been designed and implemented in the recent years; however their explicit impact on driving behavior and road accident rates has been estimated in a rather low proportion. Based on the findings of the evaluation of three road safety communication campaigns addressing the issues of drinking and driving, seat belt usage, and driving fatigue, this paper applies different types of research designs (i.e., experimental, quasi-experimental, and non-experimental designs), when estimating the effectiveness of road safety campaigns, implements a cross-design assessment, and conducts a cross-campaign evaluation. An integrated evaluation plan was developed, taking into account the structure of evaluation questions, the definition of measurable variables, the separation of the target audience into intervention (exposed to the campaign) and control (not exposed to the campaign) groups, the selection of alternative research designs, and the appropriate data collection methods and techniques. Evaluating the implementation of different research designs in estimating the effectiveness of road safety campaigns, results showed that the separate pre-post samples design demonstrated better predictability than other designs, especially in data obtained from the intervention group after the realization of the campaign. The more constructs that were added to the independent variables, the higher the values of the predictability were. The construct that most affects behavior is intention, whereas the rest of the constructs have a lower impact on behavior. This is particularly significant in the Health Belief Model (HBM). On the other hand, behavioral beliefs, normative beliefs, and descriptive norms, are significant parameters for predicting intention according to the Theory of Planned Behavior (TPB). The theoretical and applied implications of alternative research designs and their applicability in the evaluation of road safety

Restoring habitat connectivity across roads: where to begin?

NARCIS (Netherlands)

Grift, van der E.A.; Reijnen, R.; Veen, van der M.; Pelk, M.

2002-01-01

A study of the potential effect of migration measures on the viability of wildlife populations to prioritize the construction of wildlife passages and the restoration of habitat connectivity across roads in The Netherlands.

Morphogenesis in guinea grass pastures under rotational grazing strategies

Directory of Open Access Journals (Sweden)

Denise Baptaglin Montagner

2012-04-01

Full Text Available This study was conducted in order to evaluate the morphogenetic and structural characteristics of guinea grass cv. Mombasa under three post-grazing heights (intense - 30 cm, lenient - 50 cm and variable - 50 in spring-summer and 30 cm in autumn-winter when sward light interception reached 95% during regrowth. Post-grazing heights were allocated to experimental units (0.25 ha in a completely randomized block design with three replications. Post-grazing heights affected only leaf elongation rate and the number of live leaves. Pastures managed with variable post-grazing height showed higher leaf elongation rate in the summer of 2007. This management strategy also resulted in a higher number of live leaves. During the spring of 2006, plants showed lower leaf elongation rate, leaf appearance rate and number of live leaves, and greater phyllochron and leaf lifespan. In contrast, during the summer of 2007, the leaf appearance rate, leaf elongation rate, number of live leaves, and final leaf length were greater while phyllochron, stem elongation rate, and leaf senescence rate were lower. The management of the guinea grass cv. Mombasa with intense or variable post-grazing height throughout the year seems to represent an interesting management target, in terms of leaf appearance rate and number of live leaves.

Environmental Assessment of Beale AFB Grazing Lease Program

Science.gov (United States)

2012-12-01

Beale AFB will use livestock (cattle, sheep and goats ) on its properties throughout the year as needed for the control of noxious weeds, reduction...initiating a wildfire. California Farm Bureau Federation policy recognizes that grazing is the most practical and environmentally acceptable way to...Site Monitoring Well Installation and Annual Targeted Goat Grazing Project, Placer County, California. 21 September 2011.  

Effect of grazing frequency and intensity on Lolium perenne L ...

African Journals Online (AJOL)

) system. Low frequency, low intensity grazing produced lower CDMD and herbage N levels than higher grazing frequencies and intensities. These differences were, however, generally small. Overall, levels of herbage digestibility (estimated ...

An agent-based model of cattle grazing toxic Geyer's larkspur.

Science.gov (United States)

Jablonski, Kevin E; Boone, Randall B; Meiman, Paul J

2018-01-01

By killing cattle and otherwise complicating management, the many species of larkspur (Delphinium spp.) present a serious, intractable, and complex challenge to livestock grazing management in the western United States. Among the many obstacles to improving our understanding of cattle-larkspur dynamics has been the difficulty of testing different grazing management strategies in the field, as the risk of dead animals is too great. Agent-based models (ABMs) provide an effective method of testing alternate management strategies without risk to livestock. ABMs are especially useful for modeling complex systems such as livestock grazing management, and allow for realistic bottom-up encoding of cattle behavior. Here, we introduce a spatially-explicit, behavior-based ABM of cattle grazing in a pasture with a dangerous amount of Geyer's larkspur (D. geyeri). This model tests the role of herd cohesion and stocking density in larkspur intake, finds that both are key drivers of larkspur-induced toxicosis, and indicates that alteration of these factors within realistic bounds can mitigate risk. Crucially, the model points to herd cohesion, which has received little attention in the discipline, as playing an important role in lethal acute toxicosis. As the first ABM to model grazing behavior at realistic scales, this study also demonstrates the tremendous potential of ABMs to illuminate grazing management dynamics, including fundamental aspects of livestock behavior amidst ecological heterogeneity.

Risk management model in road transport systems

Science.gov (United States)

Sakhapov, R. L.; Nikolaeva, R. V.; Gatiyatullin, M. H.; Makhmutov, M. M.

2016-08-01

The article presents the results of a study of road safety indicators that influence the development and operation of the transport system. Road safety is considered as a continuous process of risk management. Authors constructed a model that relates the social risks of a major road safety indicator - the level of motorization. The model gives a fairly accurate assessment of the level of social risk for any given level of motorization. Authors calculated the dependence of the level of socio-economic costs of accidents and injured people in them. The applicability of the concept of socio-economic damage is caused by the presence of a linear relationship between the natural and economic indicators damage from accidents. The optimization of social risk is reduced to finding the extremum of the objective function that characterizes the economic effect of the implementation of measures to improve safety. The calculations make it possible to maximize the net present value, depending on the costs of improving road safety, taking into account socio-economic damage caused by accidents. The proposed econometric models make it possible to quantify the efficiency of the transportation system, allow to simulate the change in road safety indicators.

Analysis of travel patterns between road and transit-oriented development areas

International Nuclear Information System (INIS)

Lee, S.; Park, D.; Lee, C.

2010-01-01

Rapid economic growth has caused severe traffic congestion and air pollution in the Seoul metropolitan area (SMA). As a consequence, traffic demand management (TDM) policies have been implemented to mitigate traffic congestion in the region. This study analyzed travel patterns that occurred as a result of transport policy changes in Seoul between 1996 and 2002. General travel pattern changes in the SMA were compared with the travel patterns of regions with car-oriented road construction policies and public transit-invested regions. Results of the study showed that investment in road construction had no significant impact on reducing traffic congestion. The modal shift to public transit modes caused a reduction in the number of cars on roads. The study demonstrated that transit-oriented policies can be used to overcome severe traffic congestion. 7 refs., 7 tabs., 6 figs.

MANUAL. Fly ash in civil engineering, Gravel roads; HANDBOK. Flygaska i mark- och vaegbyggnad, Grusvaegar

Energy Technology Data Exchange (ETDEWEB)

Munde, Hanna; Svedberg, Bo; Macsik, Josef; Maijala, Aino; Lahtinen, Pentti; Ekdahl, Peter; Neren, Jens [Vattenfall AB, Stockholm (Sweden). Vaerme Norden

2006-01-15

Fly ash based on biofuels or coal has been used as construction material for a long time in roads and other civil engineering applications. Some example, where it has been used in roadbase and subbase of gravel roads, are in the counties of Uppsala, Soedermanland, Vaestmanland and in Finland. The use of fly ash has contributed to good function for example as bearing capacity, thaw and frost capacity and good durability. This has also reduced costs for maintenance. The objective of this project was to develop a manual to provide a base for contemporary use of fly ash in road constructions. In the manual experience from studies, field tests and regulations has been compiled. The manual handles fly ash as base for products to be used in base and subbase in gravel roads. Future user of the guidelines are mainly consultant engineers and contractors. However the aim of the manual is to also support road administrators, environmental authorities and industry. The project has been carried out parallel to another ongoing national project titled 'Guidelines, Use of alternative materials in civil engineering'. The objective of that project is to establish a base for handling of alternative materials in Sweden. Fly ash in gravel roads are mainly used in two typical applications, one without any additive in a single layer and one with fly ash mixed with gravel. The use of flyash provides functional properties such as increased stiffness, stability and enhanced frost and thaw capacity for the road construction in total. Furthermore the products based on fly ash will have low permeability and good frost and thaw durability. These properties are for example related to fly ash quality, design and construction and are in general expected to be better than for traditional constructions using, for example, sand or gravel. The properties can be enhanced further by using binders such as cement and Merit. Fly ash should always be used above the ground water table with

Livestock grazing intensity affects abundance of Common shrews (Sorex araneus) in two meadows in Denmark

Science.gov (United States)

Schmidt, Niels M; Olsen, Henrik; Leirs, Herwig

2009-01-01

Background Current nature conservation in semi-natural grasslands often includes grazing and hay cutting, as well as the abandonment of draining. Semi-natural grassland and in particular meadows constitute important habitat type for a large number of animal species in today's fragmented and intensively cultivated landscape of Europe. Here we focus on the population characteristics of Common shrews Sorex araneus in relation to livestock grazing intensity in two wet meadows in western Denmark. Results High grazing intensity had a significant negative effect on Common shrew number compared to low grazing intensity and no grazing. Common shrew abundance was generally, but not significantly, higher on the low grazing intensity plots than on the ungrazed controls. No differences in body mass, sex ratio, or reproductive output between Common shrew individuals from the various grazing treatments were found. Conclusion No negative effects of low intensity grazing on Common shrew abundance were found compared to the ungrazed control. Low intensity grazing thus seems a suitable management regime for Common shrews, when grazing is needed as part of the meadow management scheme. High intensity grazing on the other hand is not a suitable management tool. PMID:19152713

Livestock grazing intensity affects abundance of Common shrews (Sorex araneus in two meadows in Denmark

Directory of Open Access Journals (Sweden)

Olsen Henrik

2009-01-01

Full Text Available Abstract Background Current nature conservation in semi-natural grasslands often includes grazing and hay cutting, as well as the abandonment of draining. Semi-natural grassland and in particular meadows constitute important habitat type for a large number of animal species in today's fragmented and intensively cultivated landscape of Europe. Here we focus on the population characteristics of Common shrews Sorex araneus in relation to livestock grazing intensity in two wet meadows in western Denmark. Results High grazing intensity had a significant negative effect on Common shrew number compared to low grazing intensity and no grazing. Common shrew abundance was generally, but not significantly, higher on the low grazing intensity plots than on the ungrazed controls. No differences in body mass, sex ratio, or reproductive output between Common shrew individuals from the various grazing treatments were found. Conclusion No negative effects of low intensity grazing on Common shrew abundance were found compared to the ungrazed control. Low intensity grazing thus seems a suitable management regime for Common shrews, when grazing is needed as part of the meadow management scheme. High intensity grazing on the other hand is not a suitable management tool.

THE IMPROVEMENT OF TECHNOLOGY PRODUCTION OF BITUMEN FOR THE ROAD PAVING

Directory of Open Access Journals (Sweden)

N. A. Belova

2016-01-01

Full Text Available Aim. The oil (artificial bitumens, got by conversion of the oil cheese, are broadly used in the road construction. The track record of the development road covering, studies, bound with improvement their characteristic and development of the competitions among technology is presented in this article.Methods. Nowdays the modern developments in the field of production bitumen road marks are implemented using such technological-go acceptance as chemical actuated heavy oil cheese, which principles are based on regulation of the energybetween molecular interactions and optimization their dimensionality, allowing raise quality bitumen.Results. Adjusting the depth of recovery of the oxidized product, it is possible to obtain different composition, plasticity and heat resistance of the bitumen. The residual bitumen obtained by two-stage oxidation with subsequent vacuum distillation of the oxidized product comply with GOST 60/90. Vacuum gas oil in the production of residual bitumen corresponds to the motor fuel for marine installations.Conclusion. Today, the bitumen production leaves on positions packed-valuable segment oil processing industry. The Main customer roads - a state. Herewith important role as ideologues of the development of the culture road construction plays the Federal road agency, supporting developing competition amongst leading technology. Introduction new technology at conversion remaining component oils, founded on do active cheese to account physical and chemical of the influence, with using the modern equipment, including equipment, using subject to influence effects, ultrasonic and electro-magnetic fields, and others, allows to get the qualitative road bitumens from majority of the oils, scanned earlier unfit for production bitumen.

Economical energy use in road traffic

Energy Technology Data Exchange (ETDEWEB)

Diekmann, A

1980-01-01

The energy situation calls for a more rational use of energy. Although the overall share of road transport in energy consumption is only 12%, this sector is looked upon to make a substantial contribution to the saving of energy. The production of more efficient motor vehicles as well as changing patterns in the use of such vehicles will probably lead to a lower overall consumption of fuel by 1985 regardless of an increase in the number of vehicles registered. This can only be achieved if the progress made in vehicle construction is not annihilated by a deterioration in traffic flow owing to insufficient improvement of the road network.

Grazing effects on species composition in different vegetation types (La Palma, Canary Islands)

Science.gov (United States)

Arévalo, J. R.; de Nascimento, L.; Fernández-Lugo, S.; Mata, J.; Bermejo, L.

2011-05-01

Grazing management is probably one of the most extensive land uses, but its effects on plant communities have in many cases been revealed to be contradictory. Some authors have related these contradictions to the stochastic character of grazing systems. Because of that, it is necessary to implement specific analyses of grazing effects on each community, especially in natural protected areas, in order to provide the best information to managers. We studied the effects of grazing on the species composition of the main vegetation types where it takes place (grasslands, shrublands and pine forests) on the island of La Palma, Canary Islands. We used the point-quadrat intersect method to study the species composition of grazed and ungrazed areas, which also were characterized by their altitude, distance to farms, distance to settlements, year of sampling, herbaceous aboveground biomass and soil organic matter. The variables organic matter, productivity and species richness were not significantly affected by grazing. The species composition of the analyzed plant communities was affected more by variables such as altitude or distance to farms than by extensive grazing that has been traditionally carried out on the island of La Palma involving certain practices such as continuous monitoring of animals by goat keepers, medium stocking rates adjusted to the availability of natural pastures, supplementation during the dry season using local forage shrubs or mown pastures and rotating animals within grazing areas Although some studies have shown a negative effect of grazing on endangered plant species, these results cannot be freely extrapolated to the traditional grazing systems that exert a low pressure on plant communities (as has been found in this study). We consider extensive grazing as a viable way of ensuring sustainable management of the studied ecosystems.

Density and success of bird nests relative to grazing on western Montana grasslands

Science.gov (United States)

Fondell, Thomas F.; Ball, I.J.

2004-01-01

Grassland birds are declining at a faster rate than any other group of North American bird species. Livestock grazing is the primary economic use of grasslands in the western United States, but the effects of this use on distribution and productivity of grassland birds are unclear. We examined nest density and success of ground-nesting birds on grazed and ungrazed grasslands in western Montana. In comparison to grazed plots, ungrazed plots had reduced forb cover, increased litter cover, increased litter depth, and increased visual obstruction readings (VOR) of vegetation. Nest density among 10 of 11 common bird species was most strongly correlated with VOR of plots, and greatest nest density for each species occurred where mean VOR of the plot was similar to mean VOR at nests. Additionally, all bird species were relatively consistent in their choice of VOR at nests despite substantial differences in VOR among plots. We suggest that birds selected plots based in part on availability of suitable nest sites and that variation in nest density relative to grazing reflected the effect of grazing on availability of nest sites. Nest success was similar between grazed plots and ungrazed plots for two species but was lower for nests on grazed plots than on ungrazed plots for two other species because of increased rates of predation, trampling, or parasitism by brown-headed cowbirds (Molothrus ater). Other species nested almost exclusively on ungrazed plots (six species) or grazed plots (one species), precluding evaluation of the effects of grazing on nest success. We demonstrate that each species in a diverse suite of ground-nesting birds preferentially used certain habitats for nesting and that grazing altered availability of preferred nesting habitats through changes in vegetation structure and plant species composition. We also show that grazing directly or indirectly predisposed some bird species to increased nesting mortality. Management alternatives that avoid

The influence of grazing on surface climatological variables of tallgrass prairie. Final Technical Report

International Nuclear Information System (INIS)

Seastedt, T.R.; Dyer, M.I.; Turner, C.L.

1992-01-01

Mass and energy exchange between most grassland canopies and the atmosphere are mediated by grazing activities. Ambient temperatures can be increased or decreased by grazers. Data have been assembled from simulated grazing experiments on Konza Prairie Research Natural Area and observations on adjacent pastures grazed by cattle show significant changes in primary production, nutrient content, and bidirectional reflectance characteristics as a function of grazing intensity. The purpose of this research was to provide algorithms that would allow incorporation of grazing effects into models of energy budgets using remote sensing procedures. The approach involved: (1) linking empirical measurements of plant biomass and grazing intensities to remotely sensed canopy reflectance, and (2) using a higher resolution, mechanistic grazing model to derive plant ecophysiological parameters that influence reflectance and other surface climatological variables

Life Cycle Assessment Of Danish Concrete Waste Recycled In Road Base Applications

DEFF Research Database (Denmark)

Butera, Stefania; Birgisdottir, H.; Astrup, Thomas Fruergaard

2013-01-01

LCA was used to assess the environmental impacts from recycling of C&DW in road construction. The scenario comprised all stages in the end of life of C&D concrete, including recovery of materials, as well as avoided production of the substituted goods. Results show the importance of transportation...... of the material, especially when considering global warming, acidification and human toxicity categories. Ecotoxicity is dominated by leaching of pollutants from the concrete material, where Cr and Sb play a major role. Compared to landfilling of the same waste stream, reuse in road construction provides lower...

Aplanatic grazing incidence diffraction grating: a new optical element

International Nuclear Information System (INIS)

Hettrick, M.C.

1986-01-01

We present the theory of a grazing incidence reflection grating capable of imaging at submicron resolution. The optic is mechanically ruled on a spherical or cylindrical surface with varied groove spacings, delivering diffraction-limited response and a wide field of view at a selected wavelength. Geometrical aberrations are calculated on the basis of Fermat's principle, revealing significant improvements over a grazing incidence mirror. Aplanatic and quasi-aplanatic versions of the grating have applications in both imaging and scanning microscopes, microprobes, collimators, and telescopes. A 2-D crossed system of such gratings, similar to the grazing incidence mirror geometry of Kirkpatrick and Baez, could potentially provide spatial resolutions of --200 A

Roads Rehabilitation and Environment in Moldova: Some Legal and Normative Harmonization Aspects

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Cocirta Petru

2014-05-01

Full Text Available This paper analyzes the environmental regulatory reforms of the Republic of Moldova to restore roads and problems over time. Goals and objectives are the analysis of the current situation on road rehabilitation and environmental assessments in this area, as well as issues that require in rehabilitation and maintenance of roads in the Republic of Moldova.Are described briefly: general aspects of road rehabilitation issues; legislation and environmental regulations in the road; differences between Moldova and procedures of the World Bank's environmental assessment in the construction and rehabilitation of roads; problem of national legislative and normative acts harmonization to international requirements.The paper discusses specific environmental to appear on completion of the rehabilitation of roads in the Republic of Moldova. In the final part of the paper presents the conclusions and some suggestions on how to facilitate the rehabilitation of roads in accordance with Agenda 21 of the country and European and international requirements.

Poultry performance in different grazing densities: forage characteristics, losses due to grazing and feed intake

Directory of Open Access Journals (Sweden)

Luciano Cristiano França

2014-02-01

Full Text Available Morphological characteristics of three forage species grazed by rustic poultry in stocking were evaluated. Coast-cross fodder, kikuyu grass, and stylosanthes were planted in 33-m2 paddocks with two densities (m2/animal: D1 = 3m2/animal and D2 = 1m2/animal. The design was a randomized complete block with a 3 x 2 factorial (three grasses and two densities and three replications. Grass canopy height, grass mass, morphological composition (leaf, stem, and dead material, losses due to grazing, poultry weight gain and consumption, and concentrate feed conversion ratio and efficiency were evaluated. At the end of the experiment, forage and leaves masses were considered low to stylosanthes in D2 (0.28 to 0.03 kg/m2 and to kikuyu grass in D1 (0.13 to 0.05 kg/m2 and in D2 (0.11 and 0.03 kg/m2, respectively. In addition, the grass canopy height was considered low for stylosanthes (6.50 cm that could jeopardize the entry of new poultry lot. The three grass species had similar weight gain and revealed better results for 3m²/ chicken (3.20 kg/animal. Coast-cross fodder, kikuyu grass, and stylosanthes, with some exceptions, can be considered suitable for grazing fattening poultry at 3m2/animal at the evaluated time of the year (autumn.

Governing Grazing and Mobility in the Samburu Lowlands, Kenya

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Annemiek Pas

2018-03-01

Full Text Available Pastoral mobility is seen as the most effective strategy to make use of constantly shifting resources. However, mobile pastoralism as a highly-valued strategy to manage grazing areas and exploit resource variability is becoming more complex, due to recurrent droughts, loss of forage, government-led settlement schemes, and enclosure of land for community conservation, among other reasons. Yet knowledge of how Samburu pastoralists perceive these changes, and govern and innovate in their mobility patterns and resource use, has received limited attention. This paper seeks to understand how Samburu pastoralists in the drylands of northern Kenya use and govern natural resources, how livestock grazing and mobility is planned for, and how boundaries and territory are constructed and performed both within and beyond the context of (nongovernmental projects. Fieldwork for this paper was conducted in Sesia, Samburu East, and consisted of interviews, focus group discussions, and participatory observation. Findings show that livestock mobility involves longer periods and more complex distances due to a shrinking resource base and new rules of access. Although access was previously generated based on the value of reciprocity, the creation of new forms of resource management results in conditional processes of inclusion and exclusion. Policy and project implementation has historically been driven by the imperative to secure land tenure and improve pasture in bounded areas. Opportunities to support institutions that promote mobility have been given insufficient attention.

Regional Guidebook for Applying the Hydrogeomorphic Approach to Assessing the Functions of Flat and Seasonally Inundated Depression Wetlands on the Highland Rim

Science.gov (United States)

2013-06-01

soil (dirt roads, construction areas, etc.) 82 Cropland (poor condition) 80 High- density residential (1/8-acre lots) 75 Cropland (fair condition) 75...Cropland (good condition) 70 Low- density residential (1-acre lots) 68 Forest (grazed) 66 Green space (lawns, parks, golf courses, etc.) 61...VCATCH.  Increased surface runoff from residential development. Stormwater from commercial development directed to the wetland, thus increasing

Re-visiting the nutrition of dairy sheep grazing Mediterranean pastures

Directory of Open Access Journals (Sweden)

M. Decandia

2010-04-01

Full Text Available In the light of recent findings in sheep nutrition and behaviour, the diets of grazing dairy sheep should be based on forages encompassing a variety of complementary nutritional values and containing moderate levels of complementary plant secondary metabolites, until recently regarded as "anti-nutritional". In lactating sheep, pastures of tannin-containing legumes like sulla (Hedysarum coronarium and chicory (Cichorium intybus can be integrated with annual grasses for establishing sustainable artificial pastures under rainfed conditions. Diets based on these forages, while ensuring high milking performance, can mitigate the unbalance of CP to energy ratio of grazing sheep. By grazing sulla and annual or Italian ryegrass (50:50 by area as spatially conterminal monocultures or in timely sequence (complementary grazing sheep eat more and perform better than by grazing the ryegrass pasture only. Concentrate supplementation of lactating sheep should be preferably based on fibrous sources (soyhulls or beet pulps, particularly from mid-lactation onwards and when supplementation levels are high. Milk urea concentration is confirmedly a useful monitoring tool to balance protein nutrition and curb the waste of N at animal and system level.

Root Characteristics of Perennial Warm-Season Grasslands Managed for Grazing and Biomass Production

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Rattan Lal

2013-07-01

Full Text Available Minirhizotrons were used to study root growth characteristics in recently established fields dominated by perennial C4-grasses that were managed either for cattle grazing or biomass production for bioenergy in Virginia, USA. Measurements over a 13-month period showed that grazing resulted in smaller total root volumes and root diameters. Under biomass management, root volume was 40% higher (49 vs. 35 mm3 and diameters were 20% larger (0.29 vs. 0.24 mm compared to grazing. While total root length did not differ between grazed and biomass treatments, root distribution was shallower under grazed areas, with 50% of total root length in the top 7 cm of soil, compared to 41% in ungrazed exclosures. These changes (i.e., longer roots and greater root volume in the top 10 cm of soil under grazing but the reverse at 17–28 cm soil depths were likely caused by a shift in plant species composition as grazing reduced C4 grass biomass and allowed invasion of annual unsown species. The data suggest that management of perennial C4 grasslands for either grazing or biomass production can affect root growth in different ways and this, in turn, may have implications for the subsequent carbon sequestration potential of these grasslands.

Day and night grazing by cattle in the Sahel

NARCIS (Netherlands)

Ayantunde, A.A.; Fernandez-Rivera, S.; Hiernaux, P.H.; Keulen, van H.; Udo, H.M.J.

2002-01-01

The influence of night grazing on feeding behavior, nutrition and performance of cattle was studied. Twenty-four steers weighing 367 kg (SD = 76) grazed either from 0900 to 1900 (day grazers), 2100 to 0700 (night grazers) or 0900 to 1900 and 2400 to 0400 (day-and-night grazers) during 13 weeks. Four

Environmental implications of Universal Rural Road Access Program (URRAP roads in Southwestern Ethiopia: The case of Jimma and Buno Bedelle zones

Directory of Open Access Journals (Sweden)

Hassen Negesso

2018-03-01

Full Text Available Ethiopia has been undertaking numerous development programs and projects with the objective of taking a country to the middle-income countries in the near future. Universal Rural Road Access Program (URRAP roads being constructed in Jimma and Bunno Bedele zones are among the projects in Ethiopia. Although these projects are assumed to bring desirable positive change, there are sometimes negative consequences on environmental issues. Accordingly, the objective of this study was to investigate the negative sides of these projects on environmental elements. Household survey with randomly selected household heads and in-depth interview, focus group discussion (FGD and observation for purposively selected samples were used to collect relevant and required data. Thereby, data were analyzed quantitatively by using Statistical Package for Social Sciences (SPSS and qualitatively through thematic method. The findings from the analyzed data show that rural roads being constructed by URRAP have both positive and negative impacts on plant species, bird species, reptile species, mammal’s species, amphibians’ species, soil, and climate. Finally, URRAP is in dilemma and needs an extensive and frequent supervision, monitoring, inclusive, interdisciplinary and sound strategies and policies by responsible bodies at all expected levels and contexts.

RESOURCE SAVING IN CONSTRUCTION INDUSTRY WITH HIGHWAY BRANCH AS EXAMPLE

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A. V. Roudensky

2011-01-01

Full Text Available Consumption of energy is an objective (independent on cost fluctuations technical efficiency criterion of any construction or repair work. Highway/road (particularly bituminous pavement sector is an important construction industry part. Bituminous road pavement construction consists of such components as excavation and preparation of basic materials, manufacture of mixes, ready mix laying/compacting and transportation of all materials. Average energy consumption for every bituminous pavement construction component is assessed. Approach to resource and energy saving presented in the article may be used in construction industry to develop and implement innovativetechnical and organizational solutions both of general application and for individual projects.

Optimising stocking rate and grazing management to enhance environmental and production outcomes for native temperate grasslands

Science.gov (United States)

Badgery, Warwick; Zhang, Yingjun; Huang, Ding; Broadfoot, Kim; Kemp, David; Mitchell, David

2015-04-01

Stocking rate and grazing management can be altered to enhance the sustainable production of grasslands but the relative influence of each has not often been determined for native temperate grasslands. Grazing management can range from seasonal rests through to intensive rotational grazing involving >30 paddocks. In large scale grazing, it can be difficult to segregate the influence of grazing pressure from the timing of utilisation. Moreover, relative grazing pressure can change between years as seasonal conditions influence grassland production compared to the relative constant requirements of animals. This paper reports on two studies in temperate native grasslands of northern China and south eastern Australia that examined stocking rate and regionally relevant grazing management strategies. In China, the grazing experiment involved combinations of a rest, moderate or heavy grazing pressure of sheep in spring, then moderate or heavy grazing in summer and autumn. Moderate grazing pressure at 50% of the current district average, resulted in the better balance between maintaining productive and diverse grasslands, a profitable livestock system, and mitigation of greenhouse gases through increased soil carbon, methane uptake by the soil, and efficient methane emissions per unit of weight gain. Spring rests best maintained a desirable grassland composition, but had few other benefits and reduced livestock productivity due to lower feed quality from grazing later in the season. In Australia, the grazing experiment compared continuous grazing to flexible 4- and 20-paddock rotational grazing systems with sheep. Stocking rates were adjusted between systems biannually based on the average herbage mass of the grassland. No treatment degraded the perennial pasture composition, but ground cover was maintained at higher levels in the 20-paddock system even though this treatment had a higher stocking rate. Overall there was little difference in livestock production (e.g. kg

The future of forests and orangutans (Pongo abelii) in Sumatra: predicting impacts of oil palm plantations, road construction, and mechanisms for reducing carbon emissions from deforestation

Science.gov (United States)

Gaveau, David L. A.; Wich, Serge; Epting, Justin; Juhn, Daniel; Kanninen, Markku; Leader-Williams, Nigel

2009-09-01

Payments for reduced carbon emissions from deforestation (RED) are now attracting attention as a way to halt tropical deforestation. Northern Sumatra comprises an area of 65 000 km2 that is both the site of Indonesia's first planned RED initiative, and the stronghold of 92% of remaining Sumatran orangutans. Under current plans, this RED initiative will be implemented in a defined geographic area, essentially a newly established, 7500 km2 protected area (PA) comprising mostly upland forest, where guards will be recruited to enforce forest protection. Meanwhile, new roads are currently under construction, while companies are converting lowland forests into oil palm plantations. This case study predicts the effectiveness of RED in reducing deforestation and conserving orangutans for two distinct scenarios: the current plan of implementing RED within the specific boundary of a new upland PA, and an alternative scenario of implementing RED across landscapes outside PAs. Our satellite-based spatially explicit deforestation model predicts that 1313 km2 of forest would be saved from deforestation by 2030, while forest cover present in 2006 would shrink by 22% (7913 km2) across landscapes outside PAs if RED were only to be implemented in the upland PA. Meanwhile, orangutan habitat would reduce by 16% (1137 km2), resulting in the conservative loss of 1384 orangutans, or 25% of the current total population with or without RED intervention. By contrast, an estimated 7824 km2 of forest could be saved from deforestation, with maximum benefit for orangutan conservation, if RED were to be implemented across all remaining forest landscapes outside PAs. Here, RED payments would compensate land users for their opportunity costs in not converting unprotected forests into oil palm, while the construction of new roads to service the marketing of oil palm would be halted. Our predictions suggest that Indonesia's first RED initiative in an upland PA may not significantly reduce

The future of forests and orangutans (Pongo abelii) in Sumatra: predicting impacts of oil palm plantations, road construction, and mechanisms for reducing carbon emissions from deforestation

International Nuclear Information System (INIS)

Gaveau, David L A; Leader-Williams, Nigel; Wich, Serge; Epting, Justin; Juhn, Daniel; Kanninen, Markku

2009-01-01

Payments for reduced carbon emissions from deforestation (RED) are now attracting attention as a way to halt tropical deforestation. Northern Sumatra comprises an area of 65 000 km 2 that is both the site of Indonesia's first planned RED initiative, and the stronghold of 92% of remaining Sumatran orangutans. Under current plans, this RED initiative will be implemented in a defined geographic area, essentially a newly established, 7500 km 2 protected area (PA) comprising mostly upland forest, where guards will be recruited to enforce forest protection. Meanwhile, new roads are currently under construction, while companies are converting lowland forests into oil palm plantations. This case study predicts the effectiveness of RED in reducing deforestation and conserving orangutans for two distinct scenarios: the current plan of implementing RED within the specific boundary of a new upland PA, and an alternative scenario of implementing RED across landscapes outside PAs. Our satellite-based spatially explicit deforestation model predicts that 1313 km 2 of forest would be saved from deforestation by 2030, while forest cover present in 2006 would shrink by 22% (7913 km 2 ) across landscapes outside PAs if RED were only to be implemented in the upland PA. Meanwhile, orangutan habitat would reduce by 16% (1137 km 2 ), resulting in the conservative loss of 1384 orangutans, or 25% of the current total population with or without RED intervention. By contrast, an estimated 7824 km 2 of forest could be saved from deforestation, with maximum benefit for orangutan conservation, if RED were to be implemented across all remaining forest landscapes outside PAs. Here, RED payments would compensate land users for their opportunity costs in not converting unprotected forests into oil palm, while the construction of new roads to service the marketing of oil palm would be halted. Our predictions suggest that Indonesia's first RED initiative in an upland PA may not significantly reduce

Monitoring and assessment of ingestive chewing sounds for prediction of herbage intake rate in grazing cattle.

Science.gov (United States)

Galli, J R; Cangiano, C A; Pece, M A; Larripa, M J; Milone, D H; Utsumi, S A; Laca, E A

2018-05-01

Accurate measurement of herbage intake rate is critical to advance knowledge of the ecology of grazing ruminants. This experiment tested the integration of behavioral and acoustic measurements of chewing and biting to estimate herbage dry matter intake (DMI) in dairy cows offered micro-swards of contrasting plant structure. Micro-swards constructed with plastic pots were offered to three lactating Holstein cows (608±24.9 kg of BW) in individual grazing sessions (n=48). Treatments were a factorial combination of two forage species (alfalfa and fescue) and two plant heights (tall=25±3.8 cm and short=12±1.9 cm) and were offered on a gradient of increasing herbage mass (10 to 30 pots) and number of bites (~10 to 40 bites). During each grazing session, sounds of biting and chewing were recorded with a wireless microphone placed on the cows' foreheads and a digital video camera to allow synchronized audio and video recordings. Dry matter intake rate was higher in tall alfalfa than in the other three treatments (32±1.6 v. 19±1.2 g/min). A high proportion of jaw movements in every grazing session (23 to 36%) were compound jaw movements (chew-bites) that appeared to be a key component of chewing and biting efficiency and of the ability of cows to regulate intake rate. Dry matter intake was accurately predicted based on easily observable behavioral and acoustic variables. Chewing sound energy measured as energy flux density (EFD) was linearly related to DMI, with 74% of EFD variation explained by DMI. Total chewing EFD, number of chew-bites and plant height (tall v. short) were the most important predictors of DMI. The best model explained 91% of the variation in DMI with a coefficient of variation of 17%. Ingestive sounds integrate valuable information to remotely monitor feeding behavior and predict DMI in grazing cows.

The present condition of forest roads as a result of their past maintenance

OpenAIRE

Hribernik, Boštjan; Potočnik, Igor

2006-01-01

Forest roads are built for forest management purposes, to which planning of their use and maintenance is adapted. The increasing importance of non-forestry use of forest roads leads to higher maintenance standard, which by formed maintenance system causes permanent shortage of funds. Higher maintenance costs occur due to the past forest roads construction characteristics, which gave priority to quick opening of villages and farms, on the account of building quality. Other funds expenditure re...

Experimental study of collapsing properties of the compacted soil foundation of auto-road embankment

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Yushkov Boris Semenovich

2014-06-01

Full Text Available The loess collapsing soils are practically ubiquitously distributed in the Perm region. They occupy about 30% of the region area. The mass construction of buildings and structures of different purposes is conducted there. Design and construction of auto-roads on the collapsing soils by ensuring their strength and normal operation is one of the most important and difficult problems of the modern construction. It is recommended to eliminate collapsing properties of soils within the entire collapsing strata with the use of deep compaction by rammers and presoaking of foundation soils, including that with deepwater explosions, chemical or thermal fixing. Multi-year practice of construction on the collapsing soils in the regions of our country showed that during erection of the various structures the removal of the powerful loess soil collapsibility is achieved with the help of methods described above, each of which is selected on the basis of the conditions and possibilities of application. This article describes the following tasks: 1. Study and generalization of the available experience of road construction on the loess soils; 2. Zoning and classification (typing of the loess strata; 3. Selection of the engineering-geological factors influencing the choice of method for compacting collapsing soils; 4. General provisions for road construction on the collapsing soils.

Safer Roads: Comparisons Between Road Assessment Program and Composite Road Safety Index Method

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Mohd Razelan Intan Suhana

2017-01-01

Full Text Available In most countries, crash statistics have becoming very crucial in evaluating road’s safety level. In Malaysia, these data are very important in deciding crash-prone areas known as black spot where specific road improvements plan will be proposed. However due to the unavailability of reliable crash data in many developing countries, appropriate road maintenance measures are facing great troubles. In light of that, several proactive methods in defining road’s safety level such as Road Assessment Program (RAP have emerged. This research aim to compare two proactive methods that have been tested in Malaysian roads ; road assessment program and road environment risk index which was developed based on composite index theory in defining road’s safety level. Composite road environment risk index was combining several crucial environment indicators, assigning weight and aggregating the individual index together to form a single value representing the road’s safety level. Based on the results, it can be concluded that both road assessment program and composite road environment risk index are contradicted in six different ways such as type of speed used, type of analysis used and their final outcomes. However, with an aim to promote safer roads, these two methods can be used concurrently as the outcomes in both methods seems to fulfil each other’s gap very well.

Prescribed grazing for management of invasive vegetation in a hardwood forest understory

Science.gov (United States)

Ronald A. Rathfon; Songlin Fei; Jason Tower; Kenneth Andries; Michael. Neary

2014-01-01

Land managers considering prescribed grazing (PG) face a lack of information on animal stocking rates, timing of grazing, and duration of grazing to achieve desired conditions in natural ecosystems under invasion stress from a variety of nonnative invasive plant (NNIP) species. In this study we tested PG treatments using goats for reducing NNIP brush species and...

Grassland Fire and Cattle Grazing Regulate Reptile and Amphibian Assembly Among Patches

Science.gov (United States)

Larson, Danelle M.

2014-12-01

Fire and grazing are common management schemes of grasslands globally and are potential drivers of reptilian and amphibian (herpetofauna) metacommunity dynamics. Few studies have assessed the impacts of fire and cattle grazing on herpetofauna assemblages in grasslands. A patch-burn grazing study at Osage Prairie, MO, USA in 2011-2012 created landscape patches with treatments of grazing, fire, and such legacies. Response variables were measured before and after the application of treatments, and I used robust-design occupancy modeling to estimate patch occupancy and detection rate within patches, and recolonization and extinction (i.e., dispersal) across patches. I conducted redundancy analysis and a permuted multivariate analysis of variance to determine if patch type and the associated environmental factors explained herpetofauna assemblage. Estimates for reptiles indicate that occupancy was seasonally constant in Control patches ( ψ ~ 0.5), but declined to ψ ~ 0.15 in patches following the applications of fire and grazing. Local extinctions for reptiles were higher in patches with fire or light grazing ( ɛ ~ 0.7) compared to the controls. For the riparian herpetofaunal community, patch type and grass height were important predictors of abundance; further, the turtles, lizards, snakes, and adult amphibians used different patch types. The aquatic amphibian community was predicted by watershed and in-stream characteristics, irrespective of fire or grazing. The varying responses from taxonomic groups demonstrate habitat partitioning across multiple patch types undergoing fire, cattle grazing, and legacy effects. Prairies will need an array of patch types to accommodate multiple herpetofauna species.

Resilience of soils and vegetation subjected to different grazing ...

African Journals Online (AJOL)

The resilience of rangeland soils and vegetation to different levels of grazing is still poorly understood. A study was conducted to determine the recovery of a rangeland grazed at different intensities and allowed a two-year rest period. The following treatments were applied to 0.5 hectare plots: 0, 4, 8 and 16 heifers per ...

Seasonality constraints to livestock grazing intensity.

Science.gov (United States)

Fetzel, Tamara; Havlik, Petr; Herrero, Mario; Erb, Karl-Heinz

2017-04-01

Increasing food production is essential to meet the future food demand of a growing world population. In light of pressing sustainability challenges such as climate change and the importance of the global livestock system for food security as well as GHG emissions, finding ways to increasing food production sustainably and without increasing competition for food crops is essential. Yet, many unknowns relate to livestock grazing, in particular grazing intensity, an essential variable to assess the sustainability of livestock systems. Here, we explore ecological limits to grazing intensity (GI; i.e. the fraction of net primary production consumed by grazing animals) by analysing the role of seasonality in natural grasslands. We estimate seasonal limitations to GI by combining monthly net primary production data and a map of global livestock distribution with assumptions on the length of nonfavourable periods that can be bridged by livestock (e.g. by browsing dead standing biomass, storage systems or biomass conservation). This allows us to derive a seasonality-limited potential GI, which we compare with the GI prevailing in 2000. We find that GI in 2000 lies below its potential on 39% of the total global natural grasslands, which has a potential for increasing biomass extraction of up to 181 MtC/yr. In contrast, on 61% of the area GI exceeds the potential, made possible by management. Mobilizing this potential could increase milk production by 5%, meat production by 4% or contribute to free up to 2.8 Mio km² of grassland area at the global scale if the numerous socio-ecological constraints can be overcome. We discuss socio-ecological trade-offs, which may reduce the estimated potential considerably and require the establishment of sound monitoring systems and an improved understanding of livestock system's role in the Earth system. © 2017 John Wiley & Sons Ltd.

Intelligent Transport Systems in the Management of Road Transportation

Science.gov (United States)

Kalupová, Blanka; Hlavoň, Ivan

2016-11-01

Extension of European Union causes increase of free transfer of people and goods. At the same time they raised the problems associated with the transport, e.g. congestion and related accidents on roads, air traffic delays and more. To increase the efficiency and safety of transport, the European Commission supports the introduction of intelligent transport systems and services in all transport sectors. Implementation of intelligent transport systems and services in the road transport reduces accident frequency, increases the capacity of existing infrastructure and reduces congestions. Use of toll systems provides resources needed for the construction and operation of a new road network, improves public transport, cycling transport and walking transport, and also their multimodal integration with individual car transport.

Identifying significant predictors of head-on conflicts on two-lane rural roads using inductive loop detectors data.

Science.gov (United States)

Shariat-Mohaymany, Afshin; Tavakoli-Kashani, Ali; Nosrati, Hadi; Ranjbari, Andisheh

2011-12-01

To identify the significant factors that influence head-on conflicts resulting from dangerous overtaking maneuvers on 2-lane rural roads in Iran. A traffic conflict technique was applied to 12 two-lane rural roads in order to investigate the potential situations for accidents to occur and thus to identify the geometric and traffic factors affecting traffic conflicts. Traffic data were collected via the inductive loop detectors installed on these roads, and geometric characteristics were obtained through field observations. Two groups of data were then analyzed independently by Pearson's chi-square test to evaluate their relationship to traffic conflicts. The independent variables were percentage of time spent following (PTSF), percentage of heavy vehicles, directional distribution of traffic (DDT), mean speed, speed standard deviation, section type, road width, longitudinal slope, holiday or workday, and lighting condition. It was indicated that increasing the PTSF, decreasing the percentage of heavy vehicles, increasing the mean speed (up to 75 km/h), increasing DDT in the range of 0 to 60 percent, and decreasing the standard deviation of speed significantly increased the occurrence of traffic conflicts. It was also revealed that traffic conflicts occur more frequently on curve sections and on workdays. The variables road width, slope, and lighting condition were found to have a minor effect on conflict occurrence. To reduce the number of head-on conflicts on the aforementioned roads, some remedial measures are suggested, such as not constructing long "No Passing" zones and constructing passing lanes where necessary; keeping road width at the standard value; constructing roads with horizontal curves and a high radius and using appropriate road markings and overtaking-forbidden signs where it is impossible to modify the radius; providing enough light and installing caution signs/devices on the roads; and intensifying police control and supervision on workdays

Paving the Way for Invasive Species: Road Type and the Spread of Common Ragweed ( Ambrosia artemisiifolia)

Science.gov (United States)

Joly, Martin; Bertrand, Pascale; Gbangou, Roland Y.; White, Marie-Catherine; Dubé, Jean; Lavoie, Claude

2011-09-01

Roads function as prime habitats and corridors for invasive plant species. Yet despite the diversity of road types, there is little research on the influence of these types on the spread of invaders. Common ragweed ( Ambrosia artemisiifolia), a plant producing large amounts of allergenic pollen, was selected as a species model for examining the impact of road type on the spread of invasive plants. We examined this relationship in an agricultural region of Quebec, Canada. We mapped plant distribution along different road types, and constructed a model of species presence. Common ragweed was found in almost all sampling sites located along regional (97%) and local paved (81%) roads. However, verges of unpaved local roads were rarely (13%) colonized by the plant. A model (53% of variance explained), constructed with only four variables (paved regional roads, paved local roads, recently mown road verges, forest cover), correctly predicted (success rate: 89%) the spatial distribution of common ragweed. Results support the hypothesis that attributes associated with paved roads strongly favour the spread of an opportunistic invasive plant species. Specifically, larger verges and greater disturbance associated with higher traffic volume create propitious conditions for common ragweed. To date, emphasis has been placed on controlling the plant in agricultural fields, even though roadsides are probably a much larger seed source. Strategies for controlling the weed along roads have only focused on major highways, even though the considerable populations along local roads also contribute to the production of pollen. Management prioritizations developed to control common ragweed are thus questionable.

Road construction on Caspar Creek watersheds --- 10-year report on impact

Science.gov (United States)

J. S. Krammes; David M. Burns

1973-01-01

In 1960, Federal and State agencies jointly started a long-term study of the effects of logging and road building on streamflow, sedimentation, aquatic habitat, and fish populations on two watersheds of Caspar Creek, in northern California. The experimental watersheds are the North and South Forks of the Creek. The data being collected consist of continuous streamflow...

Methodology for logistic planning of forest roads for harvesting Eucalyptus globulus Labill. using optimization tools

International Nuclear Information System (INIS)

Leal Robert, Orlando; Lopez, Cesar Amilcar

2011-01-01

Using an un capacitated and non directed network model, we propose a methodology for the preliminary design of second order forests roads to extract products from Eucalyptus globulus plantations using an aerial cable system to minimize road network construction costs. The model takes into account topographical conditions and road construction costs related to the terrain slope. In order to solve the problem the Dijstrak algorithm was used, in which the minimum cost of the shortest paths that connect all the stockyards are defined. In addition, the Kruskal algorithm was used to obtain the minimum spanning tree. Finally, the network was connected to an open road for the timber to be taken to consumption centers. In order to develop the algorithms mentioned above, an application on Mat lab was designed, which gave an easier handling of the cartography data obtained from these algorithms.

Effect of Grazing Behavior on Weight Regain Post-Bariatric Surgery: A Systematic Review

Directory of Open Access Journals (Sweden)

Nathalia Pizato

2017-12-01

Full Text Available Grazing, a type of maladaptive eating behavior, has been associated with poor weight outcomes in bariatric patients. The purpose of this study was to conduct a systematic review of the association between grazing behavior and weight regain post-bariatric surgery. Literature searches, study selection, design of the method, and quality appraisal were carried out by two independent authors. The search strategy was performed until October 2017 in Medline, Embase, Cochrane, Lilacs, Scopus, Web of Science, Google Scholar, ProQuest Dissertation & Theses, and Open Grey. Of a total of 3764 articles, five papers met the inclusion criteria (four original articles and one thesis, comprising 994 subjects, mostly women. The prevalence of grazing behavior ranged from 16.6 to 46.6%, and the highest prevalence of significant weight regain was 47%. The association between grazing and weight regain was observed in four of the five evaluated studies. Our findings support an association between grazing behavior and weight regain after bariatric surgery, regardless of surgery type and contextual concept of grazing. Further studies are needed to confirm the clarity of the real prevalence and interfering factors related to grazing behavior and weight outcomes.

Tree-shrub associations in grazed woodlands: First rodents, then cattle?

NARCIS (Netherlands)

Smit, C.; Verwijmeren, M.

2011-01-01

Spatial associations of tree saplings with spiny or toxic plants in grazed woodlands are generally explained by associational resistance, i. e., protection against grazing via a well-defended neighbor. In this study, we tested whether directed seed dispersal and post-dispersal seed removal by wood

The evaluation of four Eragrostis curvula ecotypes with grazing sheep.

African Journals Online (AJOL)

There were no significant differences in the dry matter production and chemical composition of the clipped samples of the ecotypes. Keywords: afrikaans; chemical composition; dry matter production; ecotypes; eragrostis curvula; grazing; live mass; live mass gains; open rotational grazing system; production; sheep; south ...

Morphological Responses Explain Tolerance of the Bamboo Yushania microphylla to Grazing

Directory of Open Access Journals (Sweden)

Kesang Wangchuk

2014-01-01

Full Text Available Mechanisms of tolerance of the bamboo Y. microphylla to ungulate herbivory were investigated by measuring above- and belowground morphogenetic traits and biomass allocation patterns of the bamboo Y. microphylla under grazed and ungrazed conditions in a Himalayan mixed conifer forest. Data were collected from 5 populations consisting of 10 ramets each in adjacent grazed and ungrazed plots. Compared with ungrazed ramets, the aboveground morphological modifications of grazed ramets were higher culm density, shorter and thinner culms, shorter internode, and shorter top leaf. The belowground morphological modifications for the grazed ramets were thinner rhizomes, lower rhizome biomass and dry matter, more nodes, and shorter internodes. Despite the lower biomass and dry matter, the root-to-shoot ratio was higher for grazed ramets. Results suggest that Y. microphylla subjected to herbivory shows aboveground overcompensation in terms of densification at the cost of belowground biomass, but at the same time maintains a higher proportion of belowground reserves, as compared to ungrazed conditions. These responses provide adequate evidence to conclude that Y. microphylla tolerates ungulate herbivory through above- and belowground morphological modifications.

A Multi-stage Method to Extract Road from High Resolution Satellite Image

International Nuclear Information System (INIS)

Zhijian, Huang; Zhang, Jinfang; Xu, Fanjiang

2014-01-01

Extracting road information from high-resolution satellite images is complex and hardly achieves by exploiting only one or two modules. This paper presents a multi-stage method, consisting of automatic information extraction and semi-automatic post-processing. The Multi-scale Enhancement algorithm enlarges the contrast of human-made structures with the background. The Statistical Region Merging segments images into regions, whose skeletons are extracted and pruned according to geometry shape information. Setting the start and the end skeleton points, the shortest skeleton path is constructed as a road centre line. The Bidirectional Adaptive Smoothing technique smoothens the road centre line and adjusts it to right position. With the smoothed line and its average width, a Buffer algorithm reconstructs the road region easily. Seen from the last results, the proposed method eliminates redundant non-road regions, repairs incomplete occlusions, jumps over complete occlusions, and reserves accurate road centre lines and neat road regions. During the whole process, only a few interactions are needed

75 FR 71144 - Notice of Availability of Record of Decision for the Solar Millennium, LLC, Amargosa Farm Road...

Science.gov (United States)

2010-11-22

..., Amargosa Farm Road Solar Energy Project AGENCY: Bureau of Land Management, Interior. ACTION: Notice of... (ROD) for the Solar Millennium, LLC, Amargosa Farm Road Solar Energy Project Environmental Impact... INFORMATION: The applicant, Solar Millennium, LLC, is authorized to construct the Amargosa Farm Road Solar...

Patterns in Greater Sage-grouse population dynamics correspond with public grazing records at broad scales.

Science.gov (United States)

Monroe, Adrian P; Aldridge, Cameron L; Assal, Timothy J; Veblen, Kari E; Pyke, David A; Casazza, Michael L

2017-06-01

Human land use, such as livestock grazing, can have profound yet varied effects on wildlife interacting within common ecosystems, yet our understanding of land-use effects is often generalized from short-term, local studies that may not correspond with trends at broader scales. Here we used public land records to characterize livestock grazing across Wyoming, USA, and we used Greater Sage-grouse (Centrocercus urophasianus) as a model organism to evaluate responses to livestock management. With annual counts of male Sage-grouse from 743 leks (breeding display sites) during 2004-2014, we modeled population trends in response to grazing level (represented by a relative grazing index) and timing across a gradient in vegetation productivity as measured by the Normalized Vegetation Difference Index (NDVI). We found grazing can have both positive and negative effects on Sage-grouse populations depending on the timing and level of grazing. Sage-grouse populations responded positively to higher grazing levels after peak vegetation productivity, but populations declined when similar grazing levels occurred earlier, likely reflecting the sensitivity of cool-season grasses to grazing during peak growth periods. We also found support for the hypothesis that effects of grazing management vary with local vegetation productivity. These results illustrate the importance of broad-scale analyses by revealing patterns in Sage-grouse population trends that may not be inferred from studies at finer scales, and could inform sustainable grazing management in these ecosystems. © 2017 by the Ecological Society of America.

The construction of the spatio-temporal database of the ancient Silk Road within Xinjiang province during the Han and Tang dynasties

International Nuclear Information System (INIS)

Bi, Jiantao; Wang, Xingxing; Luo, Guilin; Zhu, Zuojia

2014-01-01

As the bridge over the Chinese and Western civilization, the ancient Silk Road has made a huge contribution to cultural, economic, political exchanges between China and western countries. In this paper, we treated the historical period of Western Han Dynasty, Eastern Han Dynasty and Tang Dynasty as the research time domain, and the Western Regions' countries that were existed along the Silk Road at the mean time as the research spatial domain. Then we imported these data into the SQL Server database we constructed, from which we could either query the attribute information such as population, military force, the era of the Central Plains empire, the significant events taking place in the country and some related attribute information of these events like the happened calendar year in addition to some related spatial information such as the present location, the coordinates of the capital and the territory by inputting the name of the Western countries. At the same time we could query the significant events, government institution in Central Plains and the existent Western countries at the mean time by inputting the calendar year. Based on the database, associated with GIS, RS, Flex, C# and other related information technology and network technology, we could not only browsing, searching and editing the information of the ancient Silk Road in Xinjiang Province during the Han and Tang Dynasties, but preliminary analysing as well. This is the combination of archaeology and modern information technology, and the database could also be a reference to further study, research and practice in the related fields in the future

The construction of the spatio-temporal database of the ancient Silk Road within Xinjiang province during the Han and Tang dynasties

Science.gov (United States)

Bi, Jiantao; Luo, Guilin; Wang, Xingxing; Zhu, Zuojia

2014-03-01

As the bridge over the Chinese and Western civilization, the ancient Silk Road has made a huge contribution to cultural, economic, political exchanges between China and western countries. In this paper, we treated the historical period of Western Han Dynasty, Eastern Han Dynasty and Tang Dynasty as the research time domain, and the Western Regions' countries that were existed along the Silk Road at the mean time as the research spatial domain. Then we imported these data into the SQL Server database we constructed, from which we could either query the attribute information such as population, military force, the era of the Central Plains empire, the significant events taking place in the country and some related attribute information of these events like the happened calendar year in addition to some related spatial information such as the present location, the coordinates of the capital and the territory by inputting the name of the Western countries. At the same time we could query the significant events, government institution in Central Plains and the existent Western countries at the mean time by inputting the calendar year. Based on the database, associated with GIS, RS, Flex, C# and other related information technology and network technology, we could not only browsing, searching and editing the information of the ancient Silk Road in Xinjiang Province during the Han and Tang Dynasties, but preliminary analysing as well. This is the combination of archaeology and modern information technology, and the database could also be a reference to further study, research and practice in the related fields in the future.

Automatic Road Centerline Extraction from Imagery Using Road GPS Data

Directory of Open Access Journals (Sweden)

Chuqing Cao

2014-09-01

Full Text Available Road centerline extraction from imagery constitutes a key element in numerous geospatial applications, which has been addressed through a variety of approaches. However, most of the existing methods are not capable of dealing with challenges such as different road shapes, complex scenes, and variable resolutions. This paper presents a novel method for road centerline extraction from imagery in a fully automatic approach that addresses the aforementioned challenges by exploiting road GPS data. The proposed method combines road color feature with road GPS data to detect road centerline seed points. After global alignment of road GPS data, a novel road centerline extraction algorithm is developed to extract each individual road centerline in local regions. Through road connection, road centerline network is generated as the final output. Extensive experiments demonstrate that our proposed method can rapidly and accurately extract road centerline from remotely sensed imagery.

Item Construction and Psychometric Models Appropriate for Constructed Responses

Science.gov (United States)

1991-08-01

which involve only one attribute per item. This is especially true when we are dealing with constructed-response items, we have to measure much more...Service University of Ilinois Educacional Testing Service Rosedal Road Capign. IL 61801 Princeton. K3 08541 Princeton. N3 08541 Dr. Charles LeiS Dr

Performance Prediction Modelling for Flexible Pavement on Low Volume Roads Using Multiple Linear Regression Analysis

Directory of Open Access Journals (Sweden)

C. Makendran

2015-01-01

Full Text Available Prediction models for low volume village roads in India are developed to evaluate the progression of different types of distress such as roughness, cracking, and potholes. Even though the Government of India is investing huge quantum of money on road construction every year, poor control over the quality of road construction and its subsequent maintenance is leading to the faster road deterioration. In this regard, it is essential that scientific maintenance procedures are to be evolved on the basis of performance of low volume flexible pavements. Considering the above, an attempt has been made in this research endeavor to develop prediction models to understand the progression of roughness, cracking, and potholes in flexible pavements exposed to least or nil routine maintenance. Distress data were collected from the low volume rural roads covering about 173 stretches spread across Tamil Nadu state in India. Based on the above collected data, distress prediction models have been developed using multiple linear regression analysis. Further, the models have been validated using independent field data. It can be concluded that the models developed in this study can serve as useful tools for the practicing engineers maintaining flexible pavements on low volume roads.

Vegetation patterns and nutrients in relation to grazing pressure and ...

African Journals Online (AJOL)

A major challenge confronting managers of extensive grazing systems is uneven use of erbaceous forage plants by livestock. The concentration of grazing in preferred areas or around foci points (e.g. water points) eventually results in adverse impacts in soil nutrients, vegetation structure, production and composition.

The numerical model for parametric studies of forest haul roads pavements

Directory of Open Access Journals (Sweden)

Lenka Ševelová

2010-01-01

Full Text Available Forest roads pavement structures are considered to be low volume roads. These roads serve as a mean of transport of wood and people. Besides they are currently often used for recreational purpose. The construction of the pavements should be suitable for forest transportation irrespective of their low bearing capacity. These pavement structures are very specific for special unbound materials that are used in their construction. To meet the requirements of the pavement designs and simulation analysis the FEM model in the software ANSYS was created.This paper compares two material models used for the description of the behaviour of unbound materials. The first is linear elastic according to Hook theory (H model and the second one is nonlinear plastic model Drucker-Prager (D–P model. ANSYS software has been used to create flexible model based on the parametrers of variable principle. The flexible model is parametric to realize repeated calculations useful for optimization analysis.

Phytoplankton growth and microzooplankton grazing in the subtropical Northeast Atlantic.

Directory of Open Access Journals (Sweden)

Carlos Cáceres

Full Text Available Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E. Our design included two phytoplankton size fractions (0.2-5 µm and >5 µm and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11-1.60 d(-1, especially in the case of the large fraction. Grazing rates were also high (0.15-1.29 d(-1, suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres.

Phytoplankton Growth and Microzooplankton Grazing in the Subtropical Northeast Atlantic

Science.gov (United States)

Cáceres, Carlos; Taboada, Fernando González; Höfer, Juan; Anadón, Ricardo

2013-01-01

Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E). Our design included two phytoplankton size fractions (0.2–5 µm and >5 µm) and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11–1.60 d−1), especially in the case of the large fraction. Grazing rates were also high (0.15–1.29 d−1), suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres. PMID:23935946

Effects of previous grazing nutrition and management on feedlot performance of cattle.

Science.gov (United States)

Drouillard, J S; Kuhl, G L

1999-01-01

Management strategies designed to improve grazing animal performance can influence feedlot performance and carcass traits both positively and negatively. In spite of the economic relevance of potential interactions between grazing and finishing performance, controlled experiments evaluating integrated production systems are limited in number. Effects of grazing treatments can result from, or be overshadowed by, changes in gut fill, thus making it difficult to assign precise costs to different phases of production. Published reports have considered the effects of stocking rate, duration of grazing, forage characteristics, supplementation, and growth-promoting implants on subsequent finishing performance. Improvements in cattle performance attributed to changes in stocking rate generally have been neutral to positive with respect to effects on finishing performance. Comparisons among forages have led to the suggestion that forage species may contribute to differences in gastrointestinal fill of grazing cattle, thereby influencing gain and efficiency during the subsequent finishing phase. Creep-feeding suckling calves generally has increased preweaning performance but has had relatively little influence on performance during the subsequent finishing phase. Grain supplementation of stocker cattle during the grazing period has improved grazing performance, but effects on subsequent feedlot performance have been inconsistent. Potential carryover effects from protein and mineral supplementation also have been inconclusive. Lack of congruence among studies is puzzling but may be the consequence of highly varied production systems, differences in experimental procedures, and changes in gut fill or mass of internal organs. Based on the studies reviewed, the expression or absence of compensatory growth during the finishing phase appears to be related to the nutritional quality of forages utilized in the grazing period, with higher quality forages tending to yield greater

At the end of the potholed road

DEFF Research Database (Denmark)

Jordt Jørgensen, Nanna

It took nearly 2 hours to drive the 60 km potholed Kenyan road from the administrative center in Laikipia North to the nearest big town by car or minibus. And much longer if riding on top of one of the heavy lorries transporting sand from dry riverbeds in the area to construction sites in town....... When young people travelled to town, they would often, when reaching the smoother part of the tarmac road, exclaim something like ‘now we have arrived in Kenya’ or ‘this is where development begins’, as if Laikipia North was not really part of the Kenyan state. The relation between pastoral communities...... proclaimed their community to be marginalized and in political opposition to the government, they also dreamed about infrastructure development and aspired to a closer incorporation in the Kenyan state and its development schemes. This paper explores the ambiguities of roads leading to rural places...

X-ray grazing incidence diffraction from multilayers

Energy Technology Data Exchange (ETDEWEB)

Tixier, S.; Boeni, P.; Swygenhoven, H. van; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-09-01

Grazing incidence scattering geometries using synchrotron radiation have been applied in order to characterise the roughness profiles and the structural coherence of multilayers. The lateral correlation length of the roughness profiles was evaluated using diffuse reflectivity in the `out of plane` geometry. This type of measurement is the only diffuse reflectivity technique allowing large lateral momentum transfer. It is typically suitable for correlation lengths smaller than 1000 A. The lateral structural coherence length of Ni{sub 3}Al/Ni multilayers as a function of the layer thickness was obtained by grazing incidence diffraction (GID). 3 figs., 1 ref.

Winter road access to projected works in the diversion of the Little Whale River

International Nuclear Information System (INIS)

Goulet, R.

1993-01-01

The Great Whale hydroelectric complex in northern Quebec will require diversion of the Little Whale River, involving construction of dams 40 m and 30 m high and a canal 600 m long. The main mode of access to the construction sites will be a winter road, supplemented by an airfield designed for large-capacity aircraft. The method used by Hydro-Quebec in its environmental assessment of the winter road project is described. This method comprises five steps: delimitation of the study zone; establishment of a road corridor of choice by successively eliminating territory according to given constraints; description of the physical and biological environment; determination and optimization of the road route; and evaluation of potential impacts, along with establishment of measures to mitigate those impacts. The optimal routing is determined on the basis of criteria such as the presence of permafrost, the nature of the soils, avoidance of slopes steeper than 10%, and the depth and width of ice crossings

Roads to agency : Effects of Enhancing Women’s Participation in Rural Roads Projects on Women’s Agency

OpenAIRE

World Bank Group

2015-01-01

Infrastructure projects, and more specifically, roads construction, and maintenance are one of the core operations of the World Bank. However, despite the increase of gender mainstreaming efforts in transport projects little is known about the effects of these interventions on women’s agency defined as the ability to make effective choices and transform these choices into desired outcomes’...

Possibilities and constraints for grazing in high output dairy systems

NARCIS (Netherlands)

Hennessy, D.; Delaby, L.; Pol, van den A.; Shalloo, L.

2015-01-01

In temperate and oceanic regions, grazed grass is the lowest cost feed available for milk production. In other regions, grazed grass is less important but can contribute to the diet of livestock. Within high output systems the interaction between the animal and sward is challenging for a host of

Effect of mowing and grazing on ramet emergence of Leymus ...

African Journals Online (AJOL)

user

2011-03-21

Mar 21, 2011 ... experiment was conducted in the spring of 2004 to investigate the effects on the surface soil temperature caused by mowing, grazing and grazing exclusion, and the influence of these factors on the ramets emergence characteristics. The primary effect of the treatments was significant changes in.

Herbage availability €rs a stress factor on grazed Coastcross II ...

African Journals Online (AJOL)

) relationships for Coastcross ll Bermuda grass grazed for four consecutive summer periods by young growing beef cattle. Stocking rate affected the daily. LWG/animal through its influence on herbage availability. Rota- tional grazing showed a ...

Spatial Extent of the Impact of Transported Road Materials on the Ecological Function of Forested Landscapes

Science.gov (United States)

2012-08-16

Roads have varied ecological impacts on the adjacent plant and soil environment due to physical and chemical disturbances resulting from roadway construction, roadside maintenance, and vehicle deposition. The two main areas influenced by a road are t...

Plasma protein loss associated with gastrointestinal parasitism in grazing sheep.

Science.gov (United States)

Yakoob, A Y; Holmes, P H; Parkins, J J; Armour, J

1983-01-01

Some pathophysiological effects of parasitic gastroenteritis in two groups of lambs grazing paddocks either heavily or lightly contaminated with trichostrongyle larvae were investigated between July and October 1980. The leak of plasma protein was measured on three occasions at pasture using 51chromic chloride. Total faecal output was measured indirectly using chromic oxide. Losses of 51chromic chloride-labelled plasma protein into the gastrointestinal tract were significantly higher in the lambs grazing the heavily contaminated pasture than in those grazing lightly infected ground in both July and August. The increased plasma losses were associated with high faecal egg counts, hypoalbuminaemia and elevated levels of plasma pepsinogen.

Adjustable Grazing-Incidence X-Ray Optics

Science.gov (United States)

O'Dell, Stephen L.; Reid, Paul B.

2015-01-01

With its unique subarcsecond imaging performance, NASA's Chandra X-ray Observatory illustrates the importance of fine angular resolution for x-ray astronomy. Indeed, the future of x-ray astronomy relies upon x-ray telescopes with comparable angular resolution but larger aperture areas. Combined with the special requirements of nested grazing-incidence optics, mass, and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. The goal of this technology research is to enable the cost-effective fabrication of large-area, lightweight grazing-incidence x-ray optics with subarcsecond resolution. Toward this end, the project is developing active x-ray optics using slumped-glass mirrors with thin-film piezoelectric arrays for correction of intrinsic or mount-induced distortions.

Road networks predict human influence on Amazonian bird communities.

Science.gov (United States)

Ahmed, Sadia E; Lees, Alexander C; Moura, Nárgila G; Gardner, Toby A; Barlow, Jos; Ferreira, Joice; Ewers, Robert M

2014-11-22

Road building can lead to significant deleterious impacts on biodiversity, varying from direct road-kill mortality and direct habitat loss associated with road construction, to more subtle indirect impacts from edge effects and fragmentation. However, little work has been done to evaluate the specific effects of road networks and biodiversity loss beyond the more generalized effects of habitat loss. Here, we compared forest bird species richness and composition in the municipalities of Santarém and Belterra in Pará state, eastern Brazilian Amazon, with a road network metric called 'roadless volume (RV)' at the scale of small hydrological catchments (averaging 3721 ha). We found a significant positive relationship between RV and both forest bird richness and the average number of unique species (species represented by a single record) recorded at each site. Forest bird community composition was also significantly affected by RV. Moreover, there was no significant correlation between RV and forest cover, suggesting that road networks may impact biodiversity independently of changes in forest cover. However, variance partitioning analysis indicated that RV has partially independent and therefore additive effects, suggesting that RV and forest cover are best used in a complementary manner to investigate changes in biodiversity. Road impacts on avian species richness and composition independent of habitat loss may result from road-dependent habitat disturbance and fragmentation effects that are not captured by total percentage habitat cover, such as selective logging, fire, hunting, traffic disturbance, edge effects and road-induced fragmentation. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Road networks predict human influence on Amazonian bird communities

Science.gov (United States)

Ahmed, Sadia E.; Lees, Alexander C.; Moura, Nárgila G.; Gardner, Toby A.; Barlow, Jos; Ferreira, Joice; Ewers, Robert M.

2014-01-01

Road building can lead to significant deleterious impacts on biodiversity, varying from direct road-kill mortality and direct habitat loss associated with road construction, to more subtle indirect impacts from edge effects and fragmentation. However, little work has been done to evaluate the specific effects of road networks and biodiversity loss beyond the more generalized effects of habitat loss. Here, we compared forest bird species richness and composition in the municipalities of Santarém and Belterra in Pará state, eastern Brazilian Amazon, with a road network metric called ‘roadless volume (RV)’ at the scale of small hydrological catchments (averaging 3721 ha). We found a significant positive relationship between RV and both forest bird richness and the average number of unique species (species represented by a single record) recorded at each site. Forest bird community composition was also significantly affected by RV. Moreover, there was no significant correlation between RV and forest cover, suggesting that road networks may impact biodiversity independently of changes in forest cover. However, variance partitioning analysis indicated that RV has partially independent and therefore additive effects, suggesting that RV and forest cover are best used in a complementary manner to investigate changes in biodiversity. Road impacts on avian species richness and composition independent of habitat loss may result from road-dependent habitat disturbance and fragmentation effects that are not captured by total percentage habitat cover, such as selective logging, fire, hunting, traffic disturbance, edge effects and road-induced fragmentation. PMID:25274363

Verification of road databases using multiple road models

Science.gov (United States)

Ziems, Marcel; Rottensteiner, Franz; Heipke, Christian

2017-08-01

In this paper a new approach for automatic road database verification based on remote sensing images is presented. In contrast to existing methods, the applicability of the new approach is not restricted to specific road types, context areas or geographic regions. This is achieved by combining several state-of-the-art road detection and road verification approaches that work well under different circumstances. Each one serves as an independent module representing a unique road model and a specific processing strategy. All modules provide independent solutions for the verification problem of each road object stored in the database in form of two probability distributions, the first one for the state of a database object (correct or incorrect), and a second one for the state of the underlying road model (applicable or not applicable). In accordance with the Dempster-Shafer Theory, both distributions are mapped to a new state space comprising the classes correct, incorrect and unknown. Statistical reasoning is applied to obtain the optimal state of a road object. A comparison with state-of-the-art road detection approaches using benchmark datasets shows that in general the proposed approach provides results with larger completeness. Additional experiments reveal that based on the proposed method a highly reliable semi-automatic approach for road data base verification can be designed.

Mixed farming in a grazing reserve in Northern Nigeria | Babalobi ...

African Journals Online (AJOL)

Nigeria's main pastoral development strategy is the settlement of pastoralists in grazing reserves. The goal of the strategy is to turn such nomadic pastoralists into mixed farmers who will take up crop farming to supplement livestock farming. Using the Bobi Grazing Reserve, Niger State, Nigeria as case study, the attainment ...

Transformation of a savanna grassland by drought and grazing | O ...

African Journals Online (AJOL)

The relative effects of drought and heavy grazing on the floristic composition, population size and and structure, and basal cover of an African savanna grassland were differentiated by comparing changes over eight years over eight years, which included a severe drought year, across a gradient of grazing history. Drought ...

Dairy farmers using mob grazing in Pennsylvania and New York

Science.gov (United States)

Proponents of ultra-high stocking density grazing emphasize increased forage use efficiency and soil improvement by grazing mature forage with stocking densities up to 500,000 lb per acre of beef cattle on small paddocks with rest periods up to 180 days. However, it is unclear if this management tec...

The grazing index method of range condition assessment | du Toit ...

African Journals Online (AJOL)

Owing to the difficulty of examining succession theory in the Karoo, it is suggested the ecological index method (EIM), be replaced by the grazing index method (GIM), through the introduction of grazing index values (GIV) for Karoo plant species. The GIM may provide more acceptable range condition scores and more ...

Forage selection and performance of sheep grazing dry annual range.

NARCIS (Netherlands)

Ridder, de N.; Benjamin, R.W.; Keulen, van H.

1986-01-01

During 114 days of grazing, sheep grazing a dry annual pasture in Israel selected the fine fraction available with a higher nutritive value. As this fraction became depleted and feed quality dropped, organic matter intake dropped from 1.73 to 0.75 kg/sheep/d. Sheep lost weight, body condition and

Grasses grazed by springbok and sheep | R. | African Journal of ...

African Journals Online (AJOL)

Grazing habits were determined by analysis of rumina from slaughtered springbok and sheep where springbok grazed together with Merino sheep in False Upper Karoo and together with Dorper sheep in Kalahari Thornveld. Results show that in both veld types, grass constituted about 39 percent of the dry mass intake of ...

Gravel road stabilisation of Ehnsjoevaegen, Hallstavik[Using fly ash]; Skogsbilvaegsrenovering av Ehnsjoevaegen, Hallstavik

Energy Technology Data Exchange (ETDEWEB)

Macsik, Josef; Svedberg, Bo [Ecoloop, Stockholm (Sweden)

2006-03-15

Fly ash in geotechnical applications has stabilising, isolating, low permeability and hardening effect. Fly ash can be used in road constructions with low bearing capacity, as well as on top cover material on landfills. The aim of the project was to build a road section with fly ash stabilised gravel, based on laboratory studies, and follow up technical and environmental aspect during the first year after stabilisation. The overall aim of this project was to evaluate fly ash from Holmen Paper, Hallstavik, from technical and environmental point of view in a gravel road construction. A gravel road, Ehnsjoevaegen, was stabilised with fly ash during autumn 2004. This road was a low priority road. The fly ash stabilised road section was 1300 m long. Gravel from the road Ehnsjoevaegen was stabilised and investigated in a laboratory study. Leachability of metals and geotechnical aspects were investigated. The laboratory study showed that fly ash stabilised gravel has high shear strength, however its thawing resistance is not fully acceptable. Additives of cement or merit are needed in order to increase its thawing resistance. The actual road section is not going to be used during thawing period and no additives were used. The test road is divided into different sections including a reference section. The road stabilisation work was conducted with gravel transported to Ehnsjoevaegen from off site and not with gravel from the site. Fly ash was tipped off on a levelled road, followed by tipping of gravel. Mixing fly ash and gravel was done on site by a road scraper. After the mixing the road was gravelled with 0,1 m graded gravel. In this project the fly ash had low water content. In order to get optimal compaction water was added from a tanker supplying water before compacted with a compactor. Results from the pilot test shows that fly ash stabilised gravel can be tipped, mixed and compacted effectively. Tipping can be optimised if fly ash and gravel is mixed in a mixer

Effect of grazing on the cow welfare of dairy herds evaluated by a multidimensional welfare index

DEFF Research Database (Denmark)

Burow, E.; Rousing, T.; Thomsen, P. T.

2013-01-01

Structural development in the prime sector has led to increasing herd sizes and new barn systems, followed by less summer grazing for dairy cows in Denmark. Effects of grazing on single welfare measures in dairy cows - for example, the presence of integument alterations or mortality - have been......) inspired multidimensional dairy cow welfare assessment protocol, the within-herd effect of summer grazing compared with winter barn housing in Danish dairy herds with cubicle free-stall systems for the lactating cows. Our hypothesis was that cow welfare in dairy herds was better during summer grazing than...... out to be more beneficial than few daily grazing hours (range average above 9 to 21 h) for the welfare of the dairy herds. In conclusion, this study reports a positive within-herd effect of summer grazing on dairy cow welfare, where many daily grazing hours were more beneficial than few daily grazing...

Death by 1,000 Cuts: Road Politics at Sumatra′s Kerinci Seblat National Park

Directory of Open Access Journals (Sweden)

Keith Bettinger

2014-01-01

Full Text Available This paper examines how decentralisation reforms have led to an increase in road proposals in the districts around Sumatra′s Kerinci Seblat National Park (KSNP. Roads through KSNP, which is still under the authority of the central government, are illegal, but the newly empowered districts argue that KSNP′s existence is an unfair obstacle to regional economic development, and that the roads would aid in improving the local economies. The article examines Sumatra′s extractive economy in a historical context, arguing that past economic patterns have helped in shaping the conflicts over access to resources in KSNP. District elites are attempting to maximise their access to, and benefits from, natural resources by using a variety of strategies to push for the construction of roads through KSNP; these strategies include the discursive construction of a new district geographic identity, the use of formal powers to encourage informal and illegal activities, and the formation of ad-hoc coalitions across scales. Using three case studies, I describe how the road proposals illustrate the different manifestations of centre/district struggles to gain control over, and access to, natural resources.

Ground-water problems in highway construction and maintenance

Science.gov (United States)

Rasmussen, W.C.; Haigler, L.B.

1953-01-01

This report discusses the occurrence of ground water in relation to certain problems in highway construction and maintenance. These problems are: the subdrainage of roads; quicksand; the arrest of soil creep in road cuts; the construction of lower and larger culverts necessitated by the farm-drainage program; the prevention of failure of bridge abutments and retaining walls; and the water-cement ratio of sub-water-table concrete. Although the highway problems and suggested solutions are of general interest, they are considered with special reference to the State of Delaware, in relation to the geology of that State. The new technique of soil stabilization by electroosmosis is reviewed in the hope that it might find application here in road work and pile setting, field application by the Germans and Russians is reviewed.

Assessment of forest roads and firebreaks in Turkey

African Journals Online (AJOL)

STORAGESEVER

2009-09-15

Sep 15, 2009 ... involves more than merely road construction techniques. The preparation and ... be overseeded in each fall with legumes, small grains, or ryegrass. (Turkish ... Human activities (smoking, carelessness, accidents, or ... important to get equipment and forestry workers quickly ..... Forest fire risk analysis. Hum.

Reuse of harbour sediments in the Greenlandic construction industry

DEFF Research Database (Denmark)

Belmonte, Louise Josefine; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

2010-01-01

The purpose of this study is to investigate possibilities of using harbour sediments from the Greenlandic harbours as substitutes in the Greenlandic construction industry, mainly for concrete production and road construction. Materials for use in the Greenlandic construction industry are shipped...

Road profile estimation of city roads using DTPS

Science.gov (United States)

Wang, Qi; McDaniel, J. Gregory; Sun, Nian X.; Wang, Ming L.

2013-04-01

This work presents a non-destructive and non-contact acoustic sensing approach for measuring road profile of road and bridge deck with vehicles running at normal speed without stopping traffic. This approach uses an instantaneous and real-time dynamic tire pressure sensor (DTPS) that can measure dynamic response of the tire-road interaction and increases the efficiency of currently used road profile measuring systems with vehicle body-mounted profilers and axle-mounted accelerometers. In this work, a prototype of real-time DTPS system has been developed and demonstrated on a testing van at speeds from 5 to 80 miles per hour (mph). A data analysis algorithm has been developed to remove axle dynamic motions from the measured DTPS data and to find the transfer function between dynamic tire pressure change and the road profile. Field test has been performed to estimate road profiles. The road profile resolution is approximately 5 to 10 cm in width and sensitivity is 0. 3 cm for the height road surface features at driving speeds of 5 to 80 mph.

Towards evenly distributed grazing patterns: including social context in sheep management strategies

Directory of Open Access Journals (Sweden)

Agustina di Virgilio

2016-06-01

Full Text Available Background. A large proportion of natural grasslands around the world is exposed to overgrazing resulting in land degradation and biodiversity loss. Although there is an increasing effort in the promotion of sustainable livestock management, rangeland degradation still occurs because animals’ foraging behaviour is highly selective at different spatial scales. The assessment of the ecological mechanisms modulating the spatial distribution of grazing and how to control it has critical implications for long term conservation of resources and the sustainability of livestock production. Considering the relevance of social interactions on animals’ space use patterns, our aim was to explore the potential effects of including animals’ social context into management strategies using domestic sheep grazing in rangelands as case study. Methods. We used GPS data from 19 Merino sheep (approximately 10% of the flock grazing on three different paddocks (with sizes from 80 to 1000 Ha during a year, to estimate resource selection functions of sheep grazing in flocks of different levels of heterogeneity. We assessed the effects of sheep class (i.e., ewes, wethers, and hoggets, age, body condition and time since release on habitat selection patterns. Results. We found that social rank was reflected on sheep habitat use, where dominant individuals (i.e., reproductive females used more intensively the most preferred areas and low-ranked (i.e., yearlings used less preferred areas. Our results showed that when sheep grazed on more heterogeneous flocks, grazing patterns were more evenly distributed at all the paddocks considered in this study. On the other hand, when high-ranked individuals were removed from the flock, low-ranked sheep shifted their selection patterns by increasing the use of the most preferred areas and strongly avoided to use less preferred sites (i.e., a highly selective grazing behaviour. Discussion. Although homogenization and segregation of

Towards evenly distributed grazing patterns: including social context in sheep management strategies.

Science.gov (United States)

di Virgilio, Agustina; Morales, Juan Manuel

2016-01-01

Background. A large proportion of natural grasslands around the world is exposed to overgrazing resulting in land degradation and biodiversity loss. Although there is an increasing effort in the promotion of sustainable livestock management, rangeland degradation still occurs because animals' foraging behaviour is highly selective at different spatial scales. The assessment of the ecological mechanisms modulating the spatial distribution of grazing and how to control it has critical implications for long term conservation of resources and the sustainability of livestock production. Considering the relevance of social interactions on animals' space use patterns, our aim was to explore the potential effects of including animals' social context into management strategies using domestic sheep grazing in rangelands as case study. Methods. We used GPS data from 19 Merino sheep (approximately 10% of the flock) grazing on three different paddocks (with sizes from 80 to 1000 Ha) during a year, to estimate resource selection functions of sheep grazing in flocks of different levels of heterogeneity. We assessed the effects of sheep class (i.e., ewes, wethers, and hoggets), age, body condition and time since release on habitat selection patterns. Results. We found that social rank was reflected on sheep habitat use, where dominant individuals (i.e., reproductive females) used more intensively the most preferred areas and low-ranked (i.e., yearlings) used less preferred areas. Our results showed that when sheep grazed on more heterogeneous flocks, grazing patterns were more evenly distributed at all the paddocks considered in this study. On the other hand, when high-ranked individuals were removed from the flock, low-ranked sheep shifted their selection patterns by increasing the use of the most preferred areas and strongly avoided to use less preferred sites (i.e., a highly selective grazing behaviour). Discussion. Although homogenization and segregation of flocks by classes

Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass.

Science.gov (United States)

Quiroga, R Emiliano; Golluscio, Rodolfo A; Blanco, Lisandro J; Fernández, Roberto J

2010-10-01

It has been proposed that aridity and grazing are convergent selective forces: each one selects for traits conferring resistance to both. However, this conceptual model has not yet been experimentally validated. The aim of this work was to experimentally evaluate the effect of aridity and grazing, as selective forces, on drought and grazing resistance of populations of Trichloris crinita, a native perennial forage grass of the Argentinean Arid Chaco region. We collected seeds in sites with four different combinations of aridity and grazing history (semiarid/ subhumid x heavily grazed/lightly grazed), established them in pots in a common garden, and subjected the resulting plants to different combinations of drought and defoliation. Our results agreed with the convergence model. Aridity has selected T. crinita genotypes that respond better to drought and defoliation in terms of sexual reproduction and leaf growth, and that can evade grazing due to a lower shoot: root ratio and a higher resource allocation to reserves (starch) in stem bases. Similarly, grazing has selected genotypes that respond better to drought and defoliation in terms of sexual reproduction and that can evade grazing due to a lower digestibility of leaf blades. These results allow us to extend concepts of previous models in plant adaptation to herbivory to models on plant adaptation to drought. The only variable in which we obtained a result opposite to predictions was plant height, as plants from semiarid sites were taller (and with more erect tillers) than plants from subhumid sites; we hypothesize that this result might have been a consequence of the selection exerted by the high solar radiation and soil temperatures of semiarid sites. In addition, our work allows for the prediction of the effects of dry or wet growing seasons on the performance of T. crinita plants. Our results suggest that we can rely on dry environments for selecting grazing-resistant genotypes and on high grazing pressure

Geogrid reinforced road subgrade influence on the pavement evenness

Science.gov (United States)

Šiukščius, A.; Vorobjovas, V.; Vaitkus, A.

2018-05-01

As a result of increasing geogrid reinforcement applications in the road subgrade, there are number of projects where geogrid reinforcement is used to control road pavement evenness when there are small layers of peat or mud deeper under road construction. For this task geogrid reinforcement application is not documented but widely used in Lithuania for over a decade. This paper evaluates the long term influence of the geogrid reinforced soil influence on the road surface evenness, when the organic soils stratify in the deeper layers of the subgrade. The geological conditions of the investigated sections are reviewed. The experiment methodology and test results are described, which leads to the conclusions and insights how the pavement evenness depend on the geological conditions and its enhancement. The question is raised about the need for including this geogrid application to the normative documentation. Explanation of the problems that are encountered and the need for further research is given.

Using NDVI to estimate carbon fluxes from small rotationally grazed pastures

Science.gov (United States)

Satellite-based Normalized Difference Vegetation Index (NDVI) data have been extensively used for estimating gross primary productivity (GPP) and yield of grazing lands throughout the world. However, the usefulness of satellite-based images for monitoring rotationally-grazed pastures in the northea...

Does grazing management matter for soil carbon sequestration in shortgrass steppe?

Science.gov (United States)

Considerable uncertainty remains regarding the potential of grazing management on semiarid rangelands to sequester soil carbon. Short-term (less than 1 decade) studies have determined that grazing management potentially influences fluxes of carbon, but such studies are strongly influenced by prevail...

1000 years of sustainable grazing in Nordic conditions?

DEFF Research Database (Denmark)

Brandt, Jesper

landscapes at different spatial levels. Information on much of this sort of regulation has however been lost through modern times, tended to prefer modern (nature) scientific methods primarily developed as general (meaning not spatially contextual) recommendations for raising productivity. During the later...... years this modern tradition has also been preferred by investigations to find solutions for non-sustainable types of land use in grazing systems. However, much sustainability-relevant wisdom has been accumulated in historical grazing-systems that should be included in the repertoire of knowledge...

Construction work

CERN Multimedia

2004-01-01

Construction work on building 179 will start on the 16th February 2004 and continue until November 2004. The road between buildings 179 and 158 will temporarily become a one way street from Route Democrite towards building 7. The parking places between buildings 179 and 7 will become obsolete. The ISOLDE collaboration would like to apologize for any inconveniences.

Tillering dynamics in pastures of guinea grass subjected to grazing severities under intermittent stocking

Directory of Open Access Journals (Sweden)

Denise Baptaglin Montagner

2012-03-01

Full Text Available This experiment was carried out to analyze the tillering dynamics of the species Panicum maximum cv. Mombaca subjected to three post-grazing heights: residue of 30 cm (30; residue of 50 cm (50; and residue of 50 cm during spring and summer, lowered to 40 cm in the first fall season grazing and to 30 cm in the following grazing cycle, resuming to 50 cm after the first grazing of the following spring season (50-30. Grazings were initiated whenever the swards intercepted 95% of the incident light. The post-grazing heights were allocated in the experimental units in a completely randomized block design with three replications. The density of basal tillers did not vary between the residual heights evaluated. Swards managed with variable residual height (50-30 presented higher rates of appearance and mortality of basal tillers during the summer of 2007, indicating high tiller renovation. Regardless of the post-grazing height evaluated, lower rates of appearance of basal tillers were found in the spring of 2006. The stability index of guinea grass cv. Mombaca was close to 1.0 throughout the experimental period. Swards managed with variable post-grazing present structural changes able to improve the regrowth vigor, which may be important to maximize the use of the forage species in the production system.

The future of forests and orangutans (Pongo abelii) in Sumatra: predicting impacts of oil palm plantations, road construction, and mechanisms for reducing carbon emissions from deforestation

Energy Technology Data Exchange (ETDEWEB)

Gaveau, David L A; Leader-Williams, Nigel [Durrell Institute of Conservation and Ecology, University of Kent, Canterbury, Kent CT2 7NR (United Kingdom); Wich, Serge [Great Apes Trust of Iowa, 4200 SE 44th Avenue, Des Moines, IA 50320 (United States); Epting, Justin; Juhn, Daniel [Center for Applied Biodiversity Science, Conservation International, 2011 Crystal Drive, Suite 500, Arlington, VA 22202 (United States); Kanninen, Markku, E-mail: dgaveau@yahoo.co.u, E-mail: swich@greatapetrust.or, E-mail: justep22@myfastmail.co, E-mail: d.juhn@conservation.or, E-mail: m.kanninen@cgiar.or, E-mail: n.leader-williams@kent.ac.u [Center for International Forestry Research, Jalan CIFOR, Situ Gede, Sidang Barang, Bogor, West Java (Indonesia)

2009-09-15

Payments for reduced carbon emissions from deforestation (RED) are now attracting attention as a way to halt tropical deforestation. Northern Sumatra comprises an area of 65 000 km{sup 2} that is both the site of Indonesia's first planned RED initiative, and the stronghold of 92% of remaining Sumatran orangutans. Under current plans, this RED initiative will be implemented in a defined geographic area, essentially a newly established, 7500 km{sup 2} protected area (PA) comprising mostly upland forest, where guards will be recruited to enforce forest protection. Meanwhile, new roads are currently under construction, while companies are converting lowland forests into oil palm plantations. This case study predicts the effectiveness of RED in reducing deforestation and conserving orangutans for two distinct scenarios: the current plan of implementing RED within the specific boundary of a new upland PA, and an alternative scenario of implementing RED across landscapes outside PAs. Our satellite-based spatially explicit deforestation model predicts that 1313 km{sup 2} of forest would be saved from deforestation by 2030, while forest cover present in 2006 would shrink by 22% (7913 km{sup 2}) across landscapes outside PAs if RED were only to be implemented in the upland PA. Meanwhile, orangutan habitat would reduce by 16% (1137 km{sup 2}), resulting in the conservative loss of 1384 orangutans, or 25% of the current total population with or without RED intervention. By contrast, an estimated 7824 km{sup 2} of forest could be saved from deforestation, with maximum benefit for orangutan conservation, if RED were to be implemented across all remaining forest landscapes outside PAs. Here, RED payments would compensate land users for their opportunity costs in not converting unprotected forests into oil palm, while the construction of new roads to service the marketing of oil palm would be halted. Our predictions suggest that Indonesia's first RED initiative in an

Effects of livestock grazing on grasshopper abundance on a native rangeland in Montana.

Science.gov (United States)

O'Neill, Kevin M; Olson, Bret E; Wallander, Roseann; Rolston, Marni G; Seibert, Catherine E

2010-06-01

Livestock grazing can affect habitat quality for grasshoppers through effects on food and oviposition site availability, microclimate, and other factors. Because of this, some authors have suggested that grazing programs can be used to help manage pest grasshopper populations. In a 6-yr study, we controlled access of cattle to replicated experimental plots on an Agropyron spicatum/Poa sandbergii pasture to create consistent year-to-year differences in postgrazing plant cover, with resultant affects on microclimate. After sampling grasshoppers multiple times after grazing treatments each summer, we found evidence of between-treatment differences in grasshopper abundance for the entire assemblage during 4 of the 6 yr. Some species, including Melanoplus sanguinipes (perhaps the worse rangeland grasshopper pest in the western United States), tended to be more abundant on ungrazed plots, whereas Melanoplus gladstoni often had greater densities on heavily-grazed plots. The effect of grazing on grasshopper densities in this study was lower in magnitude and less consistent among years than in a study we conducted simultaneously at a nearby site where the vegetation was dominated by the exotic species crested wheatgrass (Agropyron cristatum). Our results generally support proposals that grazing could be used to reduce pest grasshopper densities, although the effectiveness of a particular grazing scheme may vary among sites, years, and grasshopper and vegetation assemblages.

[Community structure and diversity of soil arthropods in naturally restored sandy grasslands after grazing].

Science.gov (United States)

Liu, Ren-tao; Zhao, Ha-lin; Zhao, Xue-yong

2010-11-01

Taking the Naiman Desertification Research Station under Chinese Academy of Sciences as a base, an investigation was conducted on the community structure of soil arthropods in the naturally restored sandy grasslands after different intensity grazing disturbance, with the effects of vegetation and soil on this community structure approached. In the non-grazing grassland, soil arthropods were rich in species and more in individuals, and had the highest diversity. In the restored grassland after light grazing, soil arthropods had the lowest evenness and diversity. In the restored grassland after moderate grazing, the individuals of soil arthropods were lesser but the major groups were more, and the evenness and diversity were higher. In the restored grassland after heavy grazing, the individuals of soil arthropods were more but the major groups were lesser, and the diversity was higher. Plant individuals' number, vegetation height and coverage, and soil alkalinity were the main factors affecting the soil arthropod community in naturally restored grasslands after different intensity grazing disturbance. It was implied that after 12-year exclosure of grassland, soil arthropod community could be recovered to some degree, while grazing disturbance had long-term negative effects on the arthropod community.

Milk from cows grazing on cool-season pastures provides an enhanced profile of bioactive fatty acids compared to those grazed on a monoculture of pearl millet.

Science.gov (United States)

Bainbridge, Melissa L; Egolf, Emily; Barlow, John W; Alvez, Juan P; Roman, Joe; Kraft, Jana

2017-02-15

The demand for dairy products from grass-fed cows is driven, in part, by their more desirable fatty acid (FA) profile, containing more n-3 FA and conjugated linoleic acids (CLA) than conventionally produced dairy products. This study investigated the effects of pearl millet (PM) vs. cool-season pasture (CSP) on animal performance and milk FA in a grazing system. Eight Holstein dairy cows were used in a repeated measures design with four-week periods. Forage type had no effect on animal performance (estimated dry matter intake, milk production, fat, or protein). The contents of CLA and n-3 FA in a serving of whole milk (3.25% fat) increased when cows grazed CSP compared to PM. A serving of whole milk from cows grazing PM had a higher content of saturated FA and branched-chain FA. In conclusion, the contents of various bioactive FA were higher in milk fat of cows grazing a CSP compared to PM. Copyright © 2016 Elsevier Ltd. All rights reserved.