Large antennas for ground-based astronomy above 1 THz

NARCIS (Netherlands)

Wild, Wolfgang; Guesten, R.; Holland, W. S.; Ivison, R.; Stacey, G. J.

2006-01-01

In its history astronomy has continuously expanded access to new wavelength regions both from space and on the ground. Today, one of the few unexplored regimes is the terahertz (THz) frequency range, more specifically above 1 THz (< lambda 300 mum). Astronomical observations above 1 THz are

Underside corrosion of above ground storage tanks (ASTs) | Rim ...

African Journals Online (AJOL)

... above statutory safe limits. The results showed that the physico-chemical characteristics of the water sample have diagnostic and predictive values to implicate and promote underside corrosion of the studied above ground storage tank. Journal of Applied Sciences and Environmental Management Vol. 9(1) 2005: 161-163.

The Influence of Tractor-Seat Height above the Ground on Lateral Vibrations

Directory of Open Access Journals (Sweden)

Jaime Gomez-Gil

2014-10-01

Full Text Available Farmers experience whole-body vibrations when they drive tractors. Among the various factors that influence the vibrations to which the driver is exposed are terrain roughness, tractor speed, tire type and pressure, rear axle width, and tractor seat height above the ground. In this paper the influence of tractor seat height above the ground on the lateral vibrations to which the tractor driver is exposed is studied by means of a geometrical and an experimental analysis. Both analyses show that: (i lateral vibrations experienced by a tractor driver increase linearly with tractor-seat height above the ground; (ii lateral vibrations to which the tractor driver is exposed can equal or exceed vertical vibrations; (iii in medium-size tractors, a feasible 30 cm reduction in the height of the tractor seat, which represents only 15% of its current height, will reduce the lateral vibrations by around 20%; and (iv vertical vibrations are scarcely influenced by tractor-seat height above the ground. The results suggest that manufacturers could increase the comfort of tractors by lowering tractor-seat height above the ground, which will reduce lateral vibrations.

Finite element analysis of CFRP reinforced silo structure design method

Science.gov (United States)

Yuan, Long; Xu, Xinsheng

2017-11-01

Because of poor construction, there is a serious problem of concrete quality in the silo project, which seriously affects the safe use of the structure. Concrete quality problems are mainly seen in three aspects: concrete strength cannot meet the design requirements, concrete cracking phenomenon is serious, and the unreasonable concrete vibration leads to a lot of honeycombs and surface voids. Silos are usually reinforced by carbon fiber cloth in order to ensure the safe use of silos. By the example of an alumina silo in a fly ash plant in Binzhou, Shandong Province, the alumina silo project was tested and examined on site. According to filed test results, the actual concrete strength was determined, and the damage causes of the silo was analysed. Then, a finite element analysis model of this silo was established, the CFRP cloth reinforcement method was adopted to strengthen the silo, and other technology like additional reinforcement, rebar planting, carbon fiber bonding technology was also expounded. The research of this paper is of great significance to the design and construction of silo structure.

temperature fluctuation inside inert atmosphere silos

African Journals Online (AJOL)

... the two silos for twenty-eight (28) months of storage were recorded in order to monitor temperature fluctuation at different sections inside the inert atmosphere silos loaded with two varieties of wheat namely LACRIWHT-2 (Cettia) and LACRIWHT-4 (Atilla-Gan-Atilla) from Lake Chad Research Institute, Maiduguri, Nigeria.

Cadmium uptake in above-ground parts of lettuce (Lactuca sativa L.).

Science.gov (United States)

Tang, Xiwang; Pang, Yan; Ji, Puhui; Gao, Pengcheng; Nguyen, Thanh Hung; Tong, Yan'an

2016-03-01

Because of its high Cd uptake and translocation, lettuce is often used in Cd contamination studies. However, there is a lack of information on Cd accumulation in the above-ground parts of lettuce during the entire growing season. In this study, a field experiment was carried out in a Cd-contaminated area. Above-ground lettuce parts were sampled, and the Cd content was measured using a flame atomic absorption spectrophotometer (AAS). The results showed that the Cd concentration in the above-ground parts of lettuce increased from 2.70 to 3.62mgkg(-1) during the seedling stage, but decreased from 3.62 to 2.40mgkg(-1) during organogenesis and from 2.40 to 1.64mgkg(-1) during bolting. The mean Cd concentration during the seedling stage was significantly higher than that during organogenesis (a=0.05) and bolting (a=0.01). The Cd accumulation in the above-ground parts of an individual lettuce plant could be described by a sigmoidal curve. Cadmium uptake during organogenesis was highest (80% of the total), whereas that during bolting was only 4.34%. This research further reveals that for Rome lettuce: (1) the highest Cd content of above-ground parts occurred at the end of the seedling phase; (2) the best harvest time with respect to Cd phytoaccumulation is at the end of the organogenesis stage; and (3) the organogenesis stage is the most suitable time to enhance phytoaccumulation efficiency by adjusting the root:shoot ratio. Copyright © 2015 Elsevier Inc. All rights reserved.

High Throughput Determination of Plant Height, Ground Cover, and Above-Ground Biomass in Wheat with LiDAR.

Science.gov (United States)

Jimenez-Berni, Jose A; Deery, David M; Rozas-Larraondo, Pablo; Condon, Anthony Tony G; Rebetzke, Greg J; James, Richard A; Bovill, William D; Furbank, Robert T; Sirault, Xavier R R

2018-01-01

Crop improvement efforts are targeting increased above-ground biomass and radiation-use efficiency as drivers for greater yield. Early ground cover and canopy height contribute to biomass production, but manual measurements of these traits, and in particular above-ground biomass, are slow and labor-intensive, more so when made at multiple developmental stages. These constraints limit the ability to capture these data in a temporal fashion, hampering insights that could be gained from multi-dimensional data. Here we demonstrate the capacity of Light Detection and Ranging (LiDAR), mounted on a lightweight, mobile, ground-based platform, for rapid multi-temporal and non-destructive estimation of canopy height, ground cover and above-ground biomass. Field validation of LiDAR measurements is presented. For canopy height, strong relationships with LiDAR ( r 2 of 0.99 and root mean square error of 0.017 m) were obtained. Ground cover was estimated from LiDAR using two methodologies: red reflectance image and canopy height. In contrast to NDVI, LiDAR was not affected by saturation at high ground cover, and the comparison of both LiDAR methodologies showed strong association ( r 2 = 0.92 and slope = 1.02) at ground cover above 0.8. For above-ground biomass, a dedicated field experiment was performed with destructive biomass sampled eight times across different developmental stages. Two methodologies are presented for the estimation of biomass from LiDAR: 3D voxel index (3DVI) and 3D profile index (3DPI). The parameters involved in the calculation of 3DVI and 3DPI were optimized for each sample event from tillering to maturity, as well as generalized for any developmental stage. Individual sample point predictions were strong while predictions across all eight sample events, provided the strongest association with biomass ( r 2 = 0.93 and r 2 = 0.92) for 3DPI and 3DVI, respectively. Given these results, we believe that application of this system will provide new

Siloe, Osiris, and the future perspective of swimming-pool reactors

International Nuclear Information System (INIS)

Chatoux, J.; Denielou, G.; Lerouge, B.

1964-01-01

Siloe and Osiris are two new general purpose research reactors of the 'Commissariat a l'energie Atomique'. Siloe, located within the 'Centre d'Etudes Nucleaires' of Grenoble is a swimming pool reactor of the same type as Melusine and Triton. It operates, at a nominal power of 15 MW thermal and has reached the peak power of 20 MW thermal with two thirds of its cooling system working. The fast flux above 1 MeV, which is maximum at the center of the core at 15 MW thermal is 1,2. 10 14 . The core, quite open, is downward cooled. Average specific power is 159 kW/l. Osiris is under construction at Saclay. Designed for 50 MW thermal, this reactor is upward cooled. The fast flux at the center of the core above 1 MeV is calculated to be 2, 5.10 14 . The average designed specific power is 280 kW/l. A fixed zircaloy gamma shield makes a box round the core. Future perspectives open to non-pressurised swimming-pool reactors are examined. Ways are suggested for neutronic; thermal and shielding modifications which make possible further improvements in the performances and economy of these devices. (authors) [fr

30 CFR 77.807-1 - High-voltage powerlines; clearances above ground.

Science.gov (United States)

2010-07-01

... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-1 High-voltage powerlines; clearances above ground. High-voltage powerlines located above driveways, haulageways, and railroad tracks...

Sodium vapor deposition onto a horizontal flat plate above liquid sodium surface, 2

International Nuclear Information System (INIS)

Kudo, Kazuhiko; Hirata, Masaru.

1977-01-01

The sodium vapor deposition onto a horizontal flat plate above liquid sodium surface was studied. The analysis was performed by assuming that the sodium mist is emitted into the main flow without condensation and then grows up in the main flow and drops on the sodium surface. The effects of growth of sodium mist to the system were investigated. The model of the phenomena is the sodium deposition onto a horizontal flat plate which is placed above the sodium surface with the medium cover gas. One-dimensional analysis can be done. The rate of deposition is greatly reduced when the temperature of the flat plate is lowered. For the analysis of this phenomena, it is assumed that the sodium mist grows by condensation. One of results is that the real state may be the state between the state that the condensation of mist is made in the boundary layer and the state that the mist is condensed in the main flow. Others are that there is no effect of sodium mist condensation on the rate of deposition, and that the rate of the vaporization of sodium is given by the original and the modified model. (Kato, T.)

Silos. Optimisation of underground storages' management

International Nuclear Information System (INIS)

Formaggio, M.

1997-01-01

The operation of Silos in the optimization of storages' management at Snam is presented, together with an assessment of the benefits obtained through closer attention and higher commitment of the staff, as well as better communication between Dispatching and other organizational functions. Silos has proven to be a useful decision-making tool, while applying traditional risk-assessment methods. (au)

Mapping Above-Ground Biomass in a Tropical Forest in Cambodia Using Canopy Textures Derived from Google Earth

Directory of Open Access Journals (Sweden)

Minerva Singh

2015-04-01

Full Text Available This study develops a modelling framework for utilizing very high-resolution (VHR aerial imagery for monitoring stocks of above-ground biomass (AGB in a tropical forest in Southeast Asia. Three different texture-based methods (grey level co-occurrence metric (GLCM, Gabor wavelets and Fourier-based textural ordination (FOTO were used in conjunction with two different machine learning (ML-based regression techniques (support vector regression (SVR and random forest (RF regression. These methods were implemented on both 50-cm resolution Digital Globe data extracted from Google Earth™ (GE and 8-cm commercially obtained VHR imagery. This study further examines the role of forest biophysical parameters, such as ground-measured canopy cover and vertical canopy height, in explaining AGB distribution. Three models were developed using: (i horizontal canopy variables (i.e., canopy cover and texture variables plus vertical canopy height; (ii horizontal variables only; and (iii texture variables only. AGB was variable across the site, ranging from 51.02 Mg/ha to 356.34 Mg/ha. GE-based AGB estimates were comparable to those derived from commercial aerial imagery. The findings demonstrate that novel use of this array of texture-based techniques with GE imagery can help promote the wider use of freely available imagery for low-cost, fine-resolution monitoring of forests parameters at the landscape scale.

Experimental silo-dryer-aerator for the storage of soybean grains

Directory of Open Access Journals (Sweden)

Paulo C. Coradi

Full Text Available ABSTRACT This study aimed to verify the capacity of silo-dryer-aerator prototype equipment operating as a silo-storage-aerator for soybean quality analysis. Soybeans with water content of 17% (wet basis – w.b. were dried and stored in a silo-dryer-aerator system that was designed using a drying chamber, four independent storage cells, and a static capacity of 164 kg. Another batch of grains was stored in a silo-storage-aerator with a capacity of 1,200 kg. The experiment was set up in a completely randomized factorial 5 × 4 experimental design including five grain batches stored after being dried at 30, 40, and 50 °C (mixed grains were dried at three temperatures in the silo-dryer-aerator cells and one mixed grain batch stored in the silo-storage-aerator system under ambient air conditions for four storage times (zero, one, two, and three months. There was no difference between the grains stored in the silo-dryer-aerator and silo-storage-aerator at the end of the three-month storage in terms of the physico-chemical quality. The storage time associated with drying at 50 °C caused a reduction in the physical-chemical quality of the grains. The silo-dryer-aerator system was presented as a possible alternative to store soybean (Glycine max L. grains.

Silo Storage Preconceptual Design

Energy Technology Data Exchange (ETDEWEB)

Stephanie L. Austad; Patrick W. Bragassa; Kevin M Croft; David S Ferguson; Scott C Gladson; Annette L Shafer; John H Weathersby

2012-09-01

The National Nuclear Security Administration (NNSA) has a need to develop and field a low-cost option for the long-term storage of a variety of radiological material. The storage option’s primary requirement is to provide both environmental and physical protection of the materials. Design criteria for this effort require a low initial cost and minimum maintenance over a 50-year design life. In 1999, Argonne National Laboratory-West was tasked with developing a dry silo storage option for the BN-350 Spent Fuel in Aktau Kazakhstan. Argon’s design consisted of a carbon steel cylinder approximately 16 ft long, 18 in. outside diameter and 0.375 in. wall thickness. The carbon steel silo was protected from corrosion by a duplex coating system consisting of zinc and epoxy. Although the study indicated that the duplex coating design would provide a design life well in excess of the required 50 years, the review board was concerned because of the novelty of the design and the lack of historical use. In 2012, NNSA tasked Idaho National Laboratory (INL) with reinvestigating the silo storage concept and development of alternative corrosion protection strategies. The 2012 study, “Silo Storage Concepts, Cathodic Protection Options Study” (INL/EST-12-26627), concludes that the option which best fits the design criterion is a passive cathotic protection scheme, consisting of a carbon steel tube coated with zinc or a zinc-aluminum alloy encapsulated in either concrete or a cement grout. The hot dipped zinc coating option was considered most efficient, but the flame-sprayed option could be used if a thicker zinc coating was determined to be necessary.

Local above-ground persistence of vascular plants : Life-history trade-offs and environmental constraints

NARCIS (Netherlands)

Ozinga, Wim A.; Hennekens, Stephan M.; Schaminee, Joop H. J.; Smits, Nina A. C.; Bekker, Renee M.; Roemermann, Christine; Klimes, Leos; Bakker, Jan P.; van Groenendael, Jan M.

Questions: 1. Which plant traits and habitat characteristics best explain local above-ground persistence of vascular plant species and 2. Is there a trade-off between local above-ground persistence and the ability for seed dispersal and below-ground persistence in the soil seed bank? Locations: 845

Final Harvest of Above-Ground Biomass and Allometric Analysis of the Aspen FACE Experiment

Energy Technology Data Exchange (ETDEWEB)

Mark E. Kubiske

2013-04-15

The Aspen FACE experiment, located at the US Forest Service Harshaw Research Facility in Oneida County, Wisconsin, exposes the intact canopies of model trembling aspen forests to increased concentrations of atmospheric CO2 and O3. The first full year of treatments was 1998 and final year of elevated CO2 and O3 treatments is scheduled for 2009. This proposal is to conduct an intensive, analytical harvest of the above-ground parts of 24 trees from each of the 12, 30 m diameter treatment plots (total of 288 trees) during June, July & August 2009. This above-ground harvest will be carefully coordinated with the below-ground harvest proposed by D.F. Karnosky et al. (2008 proposal to DOE). We propose to dissect harvested trees according to annual height growth increment and organ (main stem, branch orders, and leaves) for calculation of above-ground biomass production and allometric comparisons among aspen clones, species, and treatments. Additionally, we will collect fine root samples for DNA fingerprinting to quantify biomass production of individual aspen clones. This work will produce a thorough characterization of above-ground tree and stand growth and allocation above ground, and, in conjunction with the below ground harvest, total tree and stand biomass production, allocation, and allometry.

Slip-stick excitation and travelling waves excite silo honking

Science.gov (United States)

Warburton, Katarzyna; Porte, Elze; Vriend, Nathalie

2017-06-01

Silo honking is the harmonic sound generated by the discharge of a silo filled with a granular material. In industrial storage silos, the acoustic emission during discharge of PET-particles forms a nuisance for the environment and may ultimately result in structural failure. This work investigates the phenomenon experimentally using a laboratory-scale silo, and successfully correlates the frequency of the emitted sound with the periodicity of the mechanical motion of the grains. The key driver is the slip-stick interaction between the wall and the particles, characterized as a wave moving upwards through the silo. A quantitative correlation is established for the first time between the frequency of the sound, measured with an electret microphone, and the slip-frequency, measured with a high-speed camera. In the lower regions of the tube, both the slip-stick motion and the honking sound disappear.

Composição bromatológica e perfil fermentativo da silagem de capim-elefante obtida em diferentes tipos de silos experimentais e no silo tipo trincheira Chemical composition and fermentation characteristics of elephantgrass silage obtained in different experimental and bunker silos

Directory of Open Access Journals (Sweden)

Paulo Henrique Mazza Rodrigues

2002-11-01

Full Text Available Três diferentes tipos de silos experimentais, confeccionados a partir de baldes plásticos, sacos plásticos e manilhas de concreto não impermeabilizadas, foram comparados com o silo comercial tipo trincheira, amostrado a 30 e 60 cm da sua superfície, para a ensilagem do capim-elefante (cv. Napier. Utilizaram-se, ainda, dois diferentes graus de compactação, correspondentes a 400 ou 600 kg de silagem/m³. O capim (33,0% de MS e 4,2% de PB foi homogeneizado e utilizado para encher quatro silos por tratamento, distribuídos em delineamento inteiramente casualizado. Depois de abertos, estes foram amostrados, para análise da composição bromatológica e do perfil fermentativo. Silagens produzidas em manilhas de concreto não impermeabilizadas apresentaram altos valores de pH, NIDA e lignina, baixas concentrações de ácido lático e nitrogênio amoniacal, baixo poder tampão e baixa digestibilidade in vitro. Silagens produzidas em silos experimentais apresentaram qualidade superior, quanto aos parâmetros amido, carboidratos solúveis, concentração de nitrogênio amoniacal, poder tampão, ácidos acético, propiônico, butírico e lático, do que aquelas produzidas no silo comercial. Silagens obtidas dos diferentes extratos do silo comercial apresentaram maior variabilidade para os parâmetros de fermentação do que aquelas obtidas entre diferentes tipos de silos experimentais.One type of commercial silo and three types of experimental silos were used for determination of chemical composition and fermentation characteristics of elephant grass (Pennisetum purpureum (33.0% DM and 4.2% CP ensiled in two different densities (400 or 600 kg of silage/m³: 1 commercial bunker silo sampled at 30 (top and 60 (deep cm from the top; 2 plastic silo with bulsen valve; 3 plastic bag; and 4 concrete pipe. A completely randomized design was used. The concrete pipe silo produced silage with higher pH, ADIN and lignin values, as well as lower in vitro

Slip-stick excitation and travelling waves excite silo honking

Directory of Open Access Journals (Sweden)

Warburton Katarzyna

2017-01-01

Full Text Available Silo honking is the harmonic sound generated by the discharge of a silo filled with a granular material. In industrial storage silos, the acoustic emission during discharge of PET-particles forms a nuisance for the environment and may ultimately result in structural failure. This work investigates the phenomenon experimentally using a laboratory-scale silo, and successfully correlates the frequency of the emitted sound with the periodicity of the mechanical motion of the grains. The key driver is the slip-stick interaction between the wall and the particles, characterized as a wave moving upwards through the silo. A quantitative correlation is established for the first time between the frequency of the sound, measured with an electret microphone, and the slip-frequency, measured with a high-speed camera. In the lower regions of the tube, both the slip-stick motion and the honking sound disappear.

Los empujes del material almacenado en silos

Directory of Open Access Journals (Sweden)

Ayuga, Francisco

1995-04-01

Full Text Available The design of silos has been the object of scientific and technical research for a whole century and this has led to great advances in the field. The results have not always been adequately disseminated among the technicians. The aim of this paper is to present the techniques for calculation of the loads of the materials stored in silos, inform about and comment on the standards, introduce the latest works carried out worldwide based on the finite elements method and, lastly, venture an opinion on the changes this may cause in the future.

Durante un siglo el cálculo de silos ha sido objeto de investigación científica, técnica y aplicada y se han producido grandes avances. Todo este desarrollo no siempre ha sido bien dado a conocer entre los técnicos. El objeto de este artículo es precisamente presentar las técnicas de cálculo de acciones del material almacenado en silos, presentar y comentar la normativa, introducir los últimos trabajos que en el cálculo de silos se están haciendo en todo el mundo basados en la técnica de los elementos finitos y aventurar los cambios que esto va a suponer en un futuro.

Stress distribution in two-dimensional silos

Science.gov (United States)

Blanco-Rodríguez, Rodolfo; Pérez-Ángel, Gabriel

2018-01-01

Simulations of a polydispersed two-dimensional silo were performed using molecular dynamics, with different numbers of grains reaching up to 64 000, verifying numerically the model derived by Janssen and also the main assumption that the walls carry part of the weight due to the static friction between grains with themselves and those with the silo's walls. We vary the friction coefficient, the radii dispersity, the silo width, and the size of grains. We find that the Janssen's model becomes less relevant as the the silo width increases since the behavior of the stresses becomes more hydrostatic. Likewise, we get the normal and tangential stress distribution on the walls evidencing the existence of points of maximum stress. We also obtained the stress matrix with which we observe zones of concentration of load, located always at a height around two thirds of the granular columns. Finally, we observe that the size of the grains affects the distribution of stresses, increasing the weight on the bottom and reducing the normal stress on the walls, as the grains are made smaller (for the same total mass of the granulate), giving again a more hydrostatic and therefore less Janssen-type behavior for the weight of the column.

Above-ground tree outside forest (TOF) phytomass and carbon ...

Indian Academy of Sciences (India)

to classify TOF, to estimate above-ground TOF phytomass and the carbon content ... eral, trees outside forests (TOF) mean the trees ..... have been used to stratify the area, based on the ... The optimum plot size and num- .... population centres.

ERC hazard classification matrices for above ground structures and groundwater and soil remediation activities

International Nuclear Information System (INIS)

Curry, L.R.

1997-01-01

This document provides the status of the preliminary hazard classification (PHC) process for the Environmental Restoration Contractor (ERC) above ground structures and groundwater and soil remediation activities currently underway for planned for fiscal year (FY) 1997. This classification process is based on current US Department of Energy (DOE), Richland Operations Office (RL) guidance for the classification of facilities and activities containing radionuclide and nonradiological hazardous material inventories. The above ground structures presented in the matrices were drawn from the Bechtel Hanford, Inc. (BHI) Decontamination and Decommissioning (D and D) Project Facility List (DOE 1996), which identifies the facilities in the RL-Environmental Restoration baseline contract in 1997. This document contains the following two appendices: (1) Appendix A, which consists of a matrix identifying PHC documents that have been issued for BHI's above ground structures and groundwater and soil remediation activities underway or planned for FY 1997, and (2) Appendix B, which consists of a matrix showing anticipated PHCs for above ground structures, and groundwater and soil remediation activities underway or planned for FY 1997. Appendix B also shows the schedule for finalization of PHCs for above ground structures with an anticipated classification of Nuclear

Siloette, Siloe mock-up

International Nuclear Information System (INIS)

Delcroix, V.; Jeanne, G.; Mitault, G.; Schulhof, P.

1964-01-01

Siloette is the Siloe mock-up. The main installations are described: various tanks, building, auxiliaries, control systems... Precis ions are given about precautions taken for using spent fuel elements. (authors) [fr

Armazenamento de soja em silos tipo bolsa Soybean storage in bag type silos

Directory of Open Access Journals (Sweden)

Lêda R. A. Faroni

2009-03-01

Full Text Available Avaliaram-se as principais alterações qualitativas de soja armazenada em silos tipo bolsa e do óleo bruto extraído de soja com teores de água de 17,4% e 13,3%, armazenada em dois silos tipo bolsa, por 180 dias. Realizaram-se amostragens no dia do enchimento das bolsas, aos 30; 90 e 180 dias de armazenamento. Analisaram-se o teor de água, a condutividade elétrica, o percentual de germinação, a massa específica aparente da soja, além do teor de ácidos graxos livres e o índice de peróxido do óleo bruto extraído dela. Os teores de água da soja armazenada úmida e seca mantiveram-se próximos dos valores obtidos no início do período de armazenamento. Observou-se tendência de elevação da condutividade elétrica e decréscimo do percentual de germinação somente na soja úmida, principalmente após 90 dias de armazenamento. Não foi verificado decréscimo da massa específica aparente do material armazenado úmido e seco. Com relação aos parâmetros qualitativos do óleo bruto, observou-se que os valores obtidos se mantiveram abaixo do limite máximo exigido pela legislação para a comercialização de óleo bruto de soja. Pode-se concluir que os silos tipo bolsa representam alternativa viável do ponto de vista qualitativo para armazenagem de soja, e esse tipo de estrutura não ocasiona alterações qualitativas significativas no óleo bruto obtido desse material, em condições similares àquelas deste estudo.This study reports major qualitative changes in the soybean grains and the extracted crude oil when stored in bag type silos. Grains with moisture content of 17.4 or 13.3% were stored in two bag type silos. Samples were taken 30, 90 and 180 days of storage , to determine moisture content, electric conductivity of the grain leachate, germination percentage, apparent specific grain mass, and free fatty acid content, and peroxide index of the crude oil extracted from these grains. The wet and dry grains remained with

Analysis of Cylindrical Granular Material Silos under Seismic Excitation

Directory of Open Access Journals (Sweden)

Christoph Butenweg

2017-07-01

Full Text Available Silos generally work as storage structures between supply and demand for various goods, and their structural safety has long been of interest to the civil engineering profession. This is especially true for dynamically loaded silos, e.g., in case of seismic excitation. Particularly thin-walled cylindrical silos are highly vulnerable to seismic induced pressures, which can cause critical buckling phenomena of the silo shell. The analysis of silos can be carried out in two different ways. In the first, the seismic loading is modeled through statically equivalent loads acting on the shell. Alternatively, a time history analysis might be carried out, in which nonlinear phenomena due to the filling as well as the interaction between the shell and the granular material are taken into account. The paper presents a comparison of these approaches. The model used for the nonlinear time history analysis considers the granular material by means of the intergranular strain approach for hypoplasticity theory. The interaction effects between the granular material and the shell is represented by contact elements. Additionally, soil–structure interaction effects are taken into account.

The four silo STK Powderhorn Tape Library

CERN Multimedia

Patrice Loïez

2001-01-01

A view of the four silo Storage Tek (STK) Powderhorn Tape Library and its control area. Each silo can contain up to 6000 storage slots with cartridges of 10, 20, 25 or 50 GB capacity, reaching a data transfer rate of up to 12 Mbytes/sec. This will form part of the Grid system that will process the huge amounts of data produced at the LHC.

Facility design to apply cover material over radioactive residue in storage silos

International Nuclear Information System (INIS)

Fekete, L.J.; Emerson, R.J. Jr.; Heckendorn, L.A.

1991-01-01

This paper discusses the BentoGrout application system designed by Parsons under contract to the US Department of Energy (DOE) for the Environmental Remedial Action (ERA) Project, Fernald Environmental Management Project (FEMP) Fernald, Ohio, as cleaned by the K-65 removal action work plan prepared by Theta Technologies, Inc. and Westinghouse Environmental Management Company of Ohio (WEMCO) with the objectives to reduce radon emissions from the silos. The paper discusses support activities undertaken to develop the design basis and design criteria for the K-65 Silos BentoGrout Covering System. The development and execution of an application demonstration program is described with presentation of the results. Also addressed is the design of the full-scale application system and the philosophy of operational control. The instrumentation and monitoring subsystems are illustrated on system schematics. The paper concludes with an evaluation of the above activities in achieving the purpose and objectives set forth in the Removal Action Work Plan

30 CFR 56.16002 - Bins, hoppers, silos, tanks, and surge piles.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bins, hoppers, silos, tanks, and surge piles... MINES Materials Storage and Handling § 56.16002 Bins, hoppers, silos, tanks, and surge piles. (a) Bins, hoppers, silos, tanks, and surge piles, where loose unconsolidated materials are stored, handled or...

30 CFR 57.16002 - Bins, hoppers, silos, tanks, and surge piles.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bins, hoppers, silos, tanks, and surge piles... NONMETAL MINES Materials Storage and Handling § 57.16002 Bins, hoppers, silos, tanks, and surge piles. (a) Bins, hoppers, silos, tanks, and surge piles, where loose unconsolidated materials are stored, handled...

Vitrification of Simulated Fernald K-65 Silo Waste at Low Temperature

International Nuclear Information System (INIS)

Jantzen, C.M.

1999-01-01

Vitrification is the technology that has been chosen to solidify approximately 18,000 tons of geologic mill tailings at the Fernald Environmental Management Project (FEMP) in Fernald, Ohio. The geologic mill tailings are residues from the processing of pitchlende ore during 1949-1958. These waste residues are contained in silos in Operable Unit 4 (OU4) at the FEMP facility. Operable Unit 4 is one of five operable units at the FEMP. Operable Unit 4 is one of five operable units at the FEMP. Operating Unit 4 consists of four concrete storage silos and their contents. Silos 1 and 2 contain K-65 mill tailing residues and a bentonite cap, Silo 3 contains non-radioactive metal oxides, and Silo 4 is empty

Effects of above-ground plant species composition and diversity on the diversity of soil-borne microorganisms

NARCIS (Netherlands)

Kowalchuk, G.A.; Buma, D.S; De Boer, W.; Klinkhamer, P.G.L.; Van Veen, J.A.

2002-01-01

A coupling of above-ground plant diversity and below-ground microbial diversity has been implied in studies dedicated to assessing the role of macrophyte diversity on the stability, resilience, and functioning of ecosystems. Indeed, above-ground plant communities have long been assumed to drive

Correlation of horizontal and vertical components of strong ground motion for response-history analysis of safety-related nuclear facilities

Energy Technology Data Exchange (ETDEWEB)

Huang, Yin-Nan, E-mail: ynhuang@ntu.edu.tw [Dept. of Civil Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan (China); Yen, Wen-Yi, E-mail: b01501059@ntu.edu.tw [Dept. of Civil Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan (China); Whittaker, Andrew S., E-mail: awhittak@buffalo.edu [Dept. of Civil, Structural and Environmental Engineering, MCEER, State University of New York at Buffalo, Buffalo, NY 14260 (United States)

2016-12-15

Highlights: • The correlation of components of ground motion is studied using 1689 sets of records. • The data support an upper bound of 0.3 on the correlation coefficient. • The data support the related requirement in the upcoming edition of ASCE Standard 4. - Abstract: Design standards for safety-related nuclear facilities such as ASCE Standard 4-98 and ASCE Standard 43-05 require the correlation coefficient for two orthogonal components of ground motions for response-history analysis to be less than 0.3. The technical basis of this requirement was developed by Hadjian three decades ago using 50 pairs of recorded ground motions that were available at that time. In this study, correlation coefficients for (1) two horizontal components, and (2) the vertical component and one horizontal component, of a set of ground motions are computed using records from a ground-motion database compiled recently for large-magnitude shallow crustal earthquakes. The impact of the orientation of the orthogonal horizontal components on the correlation coefficient of ground motions is discussed. The rules in the forthcoming edition of ASCE Standard 4 for the correlation of components in a set of ground motions are shown to be reasonable.

Large-scale Homogenization of Bulk Materials in Mammoth Silos

NARCIS (Netherlands)

Schott, D.L.

2004-01-01

This doctoral thesis concerns the large-scale homogenization of bulk materials in mammoth silos. The objective of this research was to determine the best stacking and reclaiming method for homogenization in mammoth silos. For this purpose a simulation program was developed to estimate the

Performance Analysis of Slinky Horizontal Ground Heat Exchangers for a Ground Source Heat Pump System

Directory of Open Access Journals (Sweden)

Md. Hasan Ali

2017-10-01

Full Text Available This paper highlights the thermal performance of reclined (parallel to ground surface and standing (perpendicular to ground surface slinky horizontal ground heat exchangers (HGHEs with different water mass flow rates in the heating mode of continuous and intermittent operations. A copper tube with an outer surface protected with low-density polyethylene was selected as the tube material of the ground heat exchanger. Effects on ground temperature around the reclined slinky HGHE due to heat extraction and the effect of variation of ground temperatures on reclined HGHE performance are discussed. A higher heat exchange rate was experienced in standing HGHE than in reclined HGHE. The standing HGHE was affected by deeper ground temperature and also a greater amount of backfilled sand in standing HGHE (4.20 m3 than reclined HGHE (1.58 m3, which has higher thermal conductivity than site soil. For mass flow rate of 1 L/min with inlet water temperature 7 °C, the 4-day average heat extraction rates increased 45.3% and 127.3%, respectively, when the initial average ground temperatures at 1.5 m depth around reclined HGHE increased from 10.4 °C to 11.7 °C and 10.4 °C to 13.7 °C. In the case of intermittent operation, which boosted the thermal performance, a short time interval of intermittent operation is better than a long time interval of intermittent operation. Furthermore, from the viewpoint of power consumption by the circulating pump, the intermittent operation is more efficient than continuous operation.

On the use of plate-type normal pressure cells in silos

DEFF Research Database (Denmark)

Ramirez, Alvaro; Nielsen, Jørgen; Ayuga, F.

2010-01-01

the interpretation of results. Once the cells have been delivered from the manufacturer to the researcher, they should be calibrated and validated with reference to the measurement of pressure from a granular material against a silo wall. Two related papers deal with a specific plate-type normal pressure cell...... for use in an installation of three full-scale steel silos with different hopper eccentricities (concentric, half-eccentric and full-eccentric) as part of a silo research project. It was found to be necessary to validate the performance of the cells when measuring pressures in the silos in order to arrive...... at a solid basis for the interpretation of the pressure measurements in the silo installation aforementioned. This paper presents calibration results from three investigated methods as well as results from a finite element analysis of the plate deflection of the pressure cell which were performed to evaluate...

Extraction and textural characterization of above-ground areas from aerial stereo pairs: a quality assessment

Science.gov (United States)

Baillard, C.; Dissard, O.; Jamet, O.; Maître, H.

Above-ground analysis is a key point to the reconstruction of urban scenes, but it is a difficult task because of the diversity of the involved objects. We propose a new method to above-ground extraction from an aerial stereo pair, which does not require any assumption about object shape or nature. A Digital Surface Model is first produced by a stereoscopic matching stage preserving discontinuities, and then processed by a region-based Markovian classification algorithm. The produced above-ground areas are finally characterized as man-made or natural according to the grey level information. The quality of the results is assessed and discussed.

Natural phenomena hazards evaluation of concrete silos 1, 2, 3 and 4 at Fernald, Ohio

International Nuclear Information System (INIS)

Char, C.V.; Shiner, T.J.

1995-08-01

Fernald Environmental Management Project (FEMP) is a United States Department of Energy (DOE) site located near Cincinnati, Ohio. FEMP was formerly established as the Feed Materials Production Center (FMPC) in 1951 under the Atomic Energy Commission. FEMP is currently undergoing site wide environmental remediation. This paper addresses four concrete silos built during the 1950s and located in Operable Unit 4 (OU-4). Silos 1 and 2 known as K-65 Silos contain residues from Uranium Ore processing. Silo 3 contains metal oxides in powder form. Silo 4 is empty. The Silos are categorized as low hazard facilities and the Natural Phenomena Hazards (NPH) performance category is PC-2, based on a recently completed safety analysis report. This paper describes the structural evaluation of concrete Silos 1, 2, 3 and 4 for NPH. Non Destructive Tests (NDT) were conducted to establish the current conditions of the silos. Analytical and computer methods were used to evaluate the stresses and displacements for different silo configurations and different loading combinations. Finite element models were developed to uniquely represent each silo, and analyzed using SAP90 computer program. The SAPLOT post processor was used for rapid determination of critical areas of concern for critical loading combinations and for varying silo configurations

Exploring the Impact of Silos in Achieving Brand Orientation

DEFF Research Database (Denmark)

Gyrd-Jones, Richard I.; Helm, Clive; Munk, Jonas

2013-01-01

the achievement of brand orientation. Through inductive analysis of a case study of an organisation implementing a major brand-revitalisation strategy, this paper demonstrates how, despite a strong brand vision and high level of management commitment, functional silos associated with different mindsets......Brands are widely recognised as important sources of organisational value. Brand orientation describes the extent to which the organisation is orientated around the brand and around maximising brand potential. However, silos or divisions within the culture of an organisation can frustrate...... contributed to the failure of the new brand strategy. The paper concludes with recommendations for the brand platform to be implemented meaningfully and effectively within each silo....

Press tour Siloe CEA/GRENOBLE; Voyage de presse Siloe CEA/GRENOBLE

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-04-01

The experimental reactor, Siloe, has been stopped the 23 december 1997. This paper of the Cea Grenoble, presents the historical aspects of this reactor and its missions. It gives then a global description of the stopping and dismantling procedure, with the planning, the financing and the human impacts of the operation. The wastes management is also takes into account. (A.L.B.)

High-altitude electromagnetic pulse environment over the lossy ground

International Nuclear Information System (INIS)

Xie Yanzhao; Wang Zanji

2003-01-01

The electromagnetic field above ground produced by an incident high-altitude electromagnetic pulse plane wave striking the ground plane was described in this paper in terms of the Fresnel reflection coefficients and the numerical FFT. The pulse reflected from the ground plane always cancel the incident field for the horizontal field component, but the reflected field adds to the incident for the vertical field component. The results of several cases for variations in the observation height, angle of incidence and lossy ground electrical parameters were also presented showing different e-field components above the earth

SILOS, Reused Machine-Buildings: A Proposal for Its Transformation

Science.gov (United States)

Garrido-Cifuentes, María; Santiago-Zaragoza, Juan Manuel; Lafuente-Bolívar, Francisco Javier

2017-10-01

Second half of the 20th century: The Spanish rural landscape changes with the imposing profile of Silos. In the urban edge, next to the railroad, they are risen competing in height with church steeples. Today they are inseparable elements of the image of many peoples of cereal geography of any region of Spain. They are consequence of the autarkic economy of that time (storage of grain and state control over distribution and price) Silos were the answer given by the engineering efficiency and economy of means: A type of store operated by screw-conveyor moved with electricity, transport grain to fill high slender square plant cells. Hydraulic push offset between cells that form a matrix-walled plates constructed of thin sheets of brick or concrete block, armed only horizontally. And huge vertical loads carried by thick foundation reinforced concrete pillars. The political regime change and the energy crisis of the late seventies caused these magnificent building-machines stopped being used. Its radical specialization led them to death. After years of neglect and transfer of ownership between administrations, a consciousness has emerged in Spain (National Plan of Industrial Heritage, 2000) that has prevented its demolition, and recognize the values they bring to the landscape and structural-construction of its own, as beautiful works of Engineering which are worth cataloguing / protection. Hence this proposal tries to intervene these giants through new uses, transforming, allowing their conservation. This process investigates various structural types and implements strict standards of construction resolved with efficient construction solutions. The result is returned to society by publishing their work, while stressing heritage values, demonstrates the new strength of these local systems.

The Reclaim Screw in Mammoth Silos Operating on a Free Surface: Comparison Between Horizontal and Inclined Operation on Free Flowing Bulk Solids

NARCIS (Netherlands)

Oosterhuis, E.J.; Schott, Dingena; van Wijk, Arjen

2004-01-01

Although the screw conveyor, operating on a free surface, has been used for years as reclaim and storage equipment in mammoth silos, there is no documented knowledge about its spill characteristics. Research at Delft University of Technology together with ESI Eurosilo B.V. on the inclined use of the

Above-ground biomass investments and light interception of tropical forest trees and lianas early in succession

NARCIS (Netherlands)

Selaya, N.G.; Anten, N.P.R.; Oomen, R.J.; Matthies, M.; Werger, M.J.A.

2007-01-01

Background and Aims Crown structure and above-ground biomass investment was studied in relation to light interception of trees and lianas growing in a 6-month-old regenerating forest. Methods The vertical distribution of total above-ground biomass, height, diameter, stem density, leaf angles and

Cathodic Protection for Above Ground Storage Tank Bottom Using Data Acquisition

Directory of Open Access Journals (Sweden)

Naseer Abbood Issa Al Haboubi

2015-07-01

Full Text Available Impressed current cathodic protection controlled by computer gives the ideal solution to the changes in environmental factors and long term coating degradation. The protection potential distribution achieved and the current demand on the anode can be regulated to protection criteria, to achieve the effective protection for the system. In this paper, cathodic protection problem of above ground steel storage tank was investigated by an impressed current of cathodic protection with controlled potential of electrical system to manage the variation in soil resistivity. Corrosion controller has been implemented for above ground tank in LabView where tank's bottom potential to soil was manipulated to the desired set point (protection criterion 850 mV. National Instruments Data Acquisition (NI-DAQ and PC controllers for tank corrosion control system provides quick response to achieve steady state condition for any kind of disturbances.

Above-ground biomass equations for Pinus radiata D. Don in Asturias

Directory of Open Access Journals (Sweden)

E. Canga

2013-12-01

Full Text Available Aim of the study: The aim of this study was to develop a model for above-ground biomass estimation for Pinus radiata D. Don in Asturias.Area of study: Asturias (NE of Spain.Material and methods: Different models were fitted for the different above-ground components and weighted regression was used to correct heteroscedasticity. Finally, all the models were refitted simultaneously by use of Nonlinear Seemingly Unrelated Regressions (NSUR to ensure the additivity of biomass equations.Research highlights: A system of four biomass equations (wood, bark, crown and total biomass was develop, such that the sum of the estimations of the three biomass components is equal to the estimate of total biomass. Total and stem biomass equations explained more than 92% of observed variability, while crown and bark biomass equations explained 77% and 89% respectively.Keywords: radiata pine; plantations; biomass.

Height-diameter allometry and above ground biomass in tropical montane forests: Insights from the Albertine Rift in Africa.

Science.gov (United States)

Imani, Gérard; Boyemba, Faustin; Lewis, Simon; Nabahungu, Nsharwasi Léon; Calders, Kim; Zapfack, Louis; Riera, Bernard; Balegamire, Clarisse; Cuni-Sanchez, Aida

2017-01-01

Tropical montane forests provide an important natural laboratory to test ecological theory. While it is well-known that some aspects of forest structure change with altitude, little is known on the effects of altitude on above ground biomass (AGB), particularly with regard to changing height-diameter allometry. To address this we investigate (1) the effects of altitude on height-diameter allometry, (2) how different height-diameter allometric models affect above ground biomass estimates; and (3) how other forest structural, taxonomic and environmental attributes affect above ground biomass using 30 permanent sample plots (1-ha; all trees ≥ 10 cm diameter measured) established between 1250 and 2600 m asl in Kahuzi Biega National Park in eastern Democratic Republic of Congo. Forest structure and species composition differed with increasing altitude, with four forest types identified. Different height-diameter allometric models performed better with the different forest types, as trees got smaller with increasing altitude. Above ground biomass ranged from 168 to 290 Mg ha-1, but there were no significant differences in AGB between forests types, as tree size decreased but stem density increased with increasing altitude. Forest structure had greater effects on above ground biomass than forest diversity. Soil attributes (K and acidity, pH) also significantly affected above ground biomass. Results show how forest structural, taxonomic and environmental attributes affect above ground biomass in African tropical montane forests. They particularly highlight that the use of regional height-diameter models introduces significant biases in above ground biomass estimates, and that different height-diameter models might be preferred for different forest types, and these should be considered in future studies.

Degradation modelling for the concrete silo in TVO's VLJ repository

International Nuclear Information System (INIS)

Alcorn, S.R.; Christian-Frear, T.L.; Wallace, M.

1991-05-01

Teollisuuden Voima Oy (TVO) is currendy construcing in Finland an underground repository (the VLJ repository) for storage of low- and intermediate-level radioactive wastes generated at the Olkiluoto (TVO I and TVO II) nuclear power plant. Intermediate level wastes will be emplaced inside a large concrete silo, which is the principal engineered barrier in the repository. The primary objective of the investigation is to develop an estimate of the length of time it will take for the silo to degrade due to interaction with groundwater to the point that it fails to perform as designed. A secondary objective is to develop a methodology to estimate the length of time required for radio nuclides to migrate from the region inside the silo through the silo wall and floor to the accessible environment as a function of cement and concrete properties. Chemical modeling techniques using the codes EQ3NR/EQ6 were employed to model the degradation of the repository concrete due to interaction with groundwater, and porous flow and diffusion modeling approaches were taken to: (1) estimate the time it would take groundwater and ions to travel into and out of the silo concrete, and (2) determine how these travel times change as the concrete degrades. The results of the investigation suggest that the hydraulic conductivity of the concrete will decrease over time because of the considerable net volume increase (net porosity decrease) from the chemical interactions. Therefore, it appears likely, based on the geochemical and mass transport models, that the silo win perform as required for at least its 500-year design life, and possibly much longer

Efficacy of heat treatment for disinfestation of concrete grain silos

Science.gov (United States)

Field experiments were conducted in 2007 and 2008 to evaluate heat treatment for disinfestations of empty concrete elevator silos. A Mobile Heat Treatment Unit was used to introduce heat into silos to attain target conditions of 50°C for at least 6 h. Ventilated plastic containers with a capacity of...

Development And Evaluation Of A Prototype Household Wooden Silo

African Journals Online (AJOL)

A prototype household wooden silo with 8 kg capacity for storing shelled maize was designed, constructed and evaluated for performance. The structure was rectangular in shape, of total height of 0.6 m and width of 0.3 m, with a conical top inclined at an angle of 30 º with 0.1 m height and 0.3 m width. The silo had a top ...

Stability evaluation of ground considering dynamic vertical ground motion. Pt. 3. Effect of dynamic vertical motions on sliding safety factor of foundation ground and surrounding slope in nuclear power plant

International Nuclear Information System (INIS)

Ishikawa, Hiroyuki; Sato, Hiroaki; Kawai, Tadashi; Kanatani, Mamoru

2003-01-01

In this report, time differences of the peak accelerations between horizontal and vertical motions were investigated based on the earthquake records on the rock sites and analytical studies were carried out in order to investigate the effect of them to the fluctuations of the minimum sliding safety factors of the foundation ground and surrounding slope of nuclear power plants. Summaries of this report were as follows; (1) Maximum time difference of the peak accelerations between horizontal and vertical motions on the rock sites was approximately 10 seconds in the earthquakes within the epicenter distance of 100 km. (2) Analytical studies that employed the equivalent linear analysis with horizontal and vertical input motions were carried out against the representative models and ground properties of the foundation grounds and surrounding slopes in nuclear power plants. The combinations of the horizontal and vertical motions were determined from the above-mentioned investigation results based on the actual earthquake records. It was revealed that the fluctuations of the minimum sliding safety factors were not seriously affected by the time difference of the peak accelerations between horizontal and vertical motions. (author)

The impact of silo mentality on team identity: An organisational case study

Directory of Open Access Journals (Sweden)

Frans Cilliers

2012-03-01

Research purpose: The purpose of this research was to describe how the silo mentality impacts on team identity. Motivation for the study: During a recent organisational consultation the researchers realised that a so-called silo phenomenon had much more unexplained unconscious behaviour than was traditionally realised in terms of organisational development. It is hoped that findings from this qualitative study could give consultants entry into what happens below the surface in the silos’ unconscious. Research design, approach and method: A qualitative and descriptive research design using a case study strategy was used. Data gathering consisted of 25 narrative interviews. Using discourse analysis four themes manifested, integrated into four working hypotheses and a research hypothesis. Trustworthiness and ethical standards were ensured. Main findings: Themes that emerged were the physical environment and structure, intra-group relations, experiences of management, and intergroup relations. Practical/managerial implications: Consulting on silo behaviour as physical structures only may not be successful in changing organisational behaviour. The silo resembles an iceberg – the largest part is below the surface. Contribution/value-add: The findings evidenced silo behaviour to be an unconscious phenomenon influencing team identity negatively. Consultants are urged to study these manifestations towards understanding silos and their effect on team identity better.

Granular Silo collapse: an experimental study

Science.gov (United States)

Clement, Eric; Gutierriez, Gustavo; Boltenhagen, Philippe; Lanuza, Jose

2008-03-01

We present an experimental work that develop some basic insight into the pre-buckling behavior and the buckling transition toward plastic collapse of a granular silo. We study different patterns of deformation generated on thin paper cylindrical shells during granular discharge. We study the collapse threshold for different bed height, flow rates and grain sizes. We compare the patterns that appear during the discharge of spherical beads, with those obtained in the axially compressed cylindrical shells. When the height of the granular column is close to the collapse threshold, we describe a ladder like pattern that rises around the cylinder surface in a spiral path of diamond shaped localizations, and develops into a plastic collapsing fold that grows around the collapsing silo.

Regional analysis of ground and above-ground climate. Part I. Regional suitability of earth-tempering practices: summary and conclusions. Part II. Bioclimatic data

Energy Technology Data Exchange (ETDEWEB)

Labs, K.

The regional suitability of underground construction as a climate-control technique is discussed with reference to (1) a bioclimatic analysis of long-term weather data for 29 locations in the United States to determine appropriate above-ground climate-control techniques, (2) a data base of synthesized ground temperatures for the coterminous United States, and (3) monthly dewpoint ground temperature comparisons for identifying the relative likelihood of condensation, from one region to another. It is concluded that the suitability of earth tempering as a practice and of specific earth-sheltered design stereotypes varies geographically. While the subsurface almost always provides a thermal advantage on its own terms when compared to above-ground climatic data, it can, nonetheless, compromise the effectiveness of other, regionally more important climate-control techniques. Also contained in the report are reviews of above- and below-ground climate mapping schemes related to human comfort and architectural design, and a detailed description of a theoretical model of ground temperature, heat flow, and heat storage in the ground. Strategies of passive climate control are presented in a discussion of the building bioclimatic analysis procedure which has been applied in a computer analysis of 30 years of weather data for each of 29 locations in the United States. 3 references, 12 figures, 14 tables.

Horizontal ground coupled heat pump: Thermal-economic modeling and optimization

Energy Technology Data Exchange (ETDEWEB)

Sanaye, Sepehr; Niroomand, Behzad [Energy Systems Improvement Laboratory (ESIL), Department of Mechanical Engineering, Iran University of Science and Technology (IUST) (Iran)

2010-12-15

The modeling and optimizing processes of a Ground Coupled Heat Pump (GCHP) with closed Horizontal Ground Heat eXchanger (HGHX) are presented in this paper. After thermal modeling of GCHP including HGHX, the optimum design parameters of the system were estimated by minimizing a defined objective function (total of investment and operation costs) subject to a list of constraints. This procedure was performed applying Genetic Algorithm technique. For given heating/cooling loads and various climatic conditions, the optimum values of saturated temperature/pressure of condenser and evaporator as well as inlet and outlet temperatures of the water source in cooling and heating modes were predicted. Then, for our case study, the design parameters as well as the configuration of HGHX were obtained. Furthermore, the sensitivity analysis of change in the total annual cost of the system and optimum design parameters with the climatic conditions, cooling/heating capacity, and soil type were discussed. (author)

Horizontal ground coupled heat pump: Thermal-economic modeling and optimization

International Nuclear Information System (INIS)

Sanaye, Sepehr; Niroomand, Behzad

2010-01-01

The modeling and optimizing processes of a Ground Coupled Heat Pump (GCHP) with closed Horizontal Ground Heat eXchanger (HGHX) are presented in this paper. After thermal modeling of GCHP including HGHX, the optimum design parameters of the system were estimated by minimizing a defined objective function (total of investment and operation costs) subject to a list of constraints. This procedure was performed applying Genetic Algorithm technique. For given heating/cooling loads and various climatic conditions, the optimum values of saturated temperature/pressure of condenser and evaporator as well as inlet and outlet temperatures of the water source in cooling and heating modes were predicted. Then, for our case study, the design parameters as well as the configuration of HGHX were obtained. Furthermore, the sensitivity analysis of change in the total annual cost of the system and optimum design parameters with the climatic conditions, cooling/heating capacity, and soil type were discussed.

Carbon dioxide not suitable for extinguishment of smouldering silo fires: static electricity may cause silo explosion

DEFF Research Database (Denmark)

Hedlund, Frank Huess

2018-01-01

argues that injection of inert carbon dioxide into the silo headspace is unsafe. Carbon dioxide is generally available as a liquid under high pressure. When discharged, small particles of dry ice are formed. The rapid flow of particles can generate considerable amounts of static electricity, which can...... act as a source of ignition if ignitable pyrolysis gasses are present. This article discusses a serious wood pellet smouldering fire and silo explosion in Norway in 2010, which took place when firefighters discharged portable CO2 fire extinguishers into the headspace. The attempt to suppress the fire...... may have ignited pyrolysis gasses. The article examines selected guidelines, standards, popular wood pellet handbooks and other literature and argues that the electrostatic hazard is widely under-appreciated. In the past, major explosions have been attributed to electrostatic ignition of flammable...

A terrestrial biosphere model optimized to atmospheric CO2 concentration and above ground woody biomass

Science.gov (United States)

Saito, M.; Ito, A.; Maksyutov, S. S.

2013-12-01

This study documents an optimization of a prognostic biosphere model (VISIT; Vegetation Integrative Similator for Trace gases) to observations of atmospheric CO2 concentration and above ground woody biomass by using a Bayesian inversion method combined with an atmospheric tracer transport model (NIES-TM; National Institute for Environmental Studies / Frontier Research Center for Global Change (NIES/FRCGC) off-line global atmospheric tracer transport model). The assimilated observations include 74 station records of surface atmospheric CO2 concentration and aggregated grid data sets of above ground woody biomass (AGB) and net primary productivity (NPP) over the globe. Both the biosphere model and the atmospheric transport model are used at a horizontal resolution of 2.5 deg x 2.5 deg grid with temporal resolutions of a day and an hour, respectively. The atmospheric transport model simulates atmospheric CO2 concentration with nine vertical levels using daily net ecosystem CO2 exchange rate (NEE) from the biosphere model, oceanic CO2 flux, and fossil fuel emission inventory. The models are driven by meteorological data from JRA-25 (Japanese 25-year ReAnalysis) and JCDAS (JMA Climate Data Assimilation System). Statistically optimum physiological parameters in the biosphere model are found by iterative minimization of the corresponding Bayesian cost function. We select thirteen physiological parameter with high sensitivity to NEE, NPP, and AGB for the minimization. Given the optimized physiological parameters, the model shows error reductions in seasonal variation of the CO2 concentrations especially in the northern hemisphere due to abundant observation stations, while errors remain at a few stations that are located in coastal coastal area and stations in the southern hemisphere. The model also produces moderate estimates of the mean magnitudes and probability distributions in AGB and NPP for each biome. However, the model fails in the simulation of the terrestrial

The valuation of commercial grain silos

African Journals Online (AJOL)

The valuation of grain silos is a complex exercise when one considers all the variables that affect their ... their grains, larger grain-processing companies, traders, importers or exporters that have ..... 2015: personal interview). The percentages ...

Energy and exergy analysis of a ground-coupled heat pump system with two horizontal ground heat exchangers

Energy Technology Data Exchange (ETDEWEB)

Esen, Hikmet; Esen, Mehmet [Department of Mechanical Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey); Inalli, Mustafa; Pihtili, Kazim [Department of Mechanical Engineering, Faculty of Engineering, Firat University, 23119 Elazig (Turkey)

2007-10-15

In this paper we investigate of energetic and exergetic efficiencies of ground-coupled heat pump (GCHP) system as a function of depth trenches for heating season. The horizontal ground heat exchangers (HGHEs) were used and it were buried with in 1 m (HGHE1) and 2 m (HGHE2) depth trenches. The energy efficiency of GCHP systems are obtained to 2.5 and 2.8, respectively, while the exergetic efficiencies of the overall system are found to be 53.1% and 56.3%, respectively, for HGHE1 and HGHE2. The irreversibility of HGHE2 is less than of the HGHE1 as about 2.0%. The results show that the energetic and exergetic efficiencies of the system increase when increasing the heat source (ground) temperature for heating season. And the end of this study, we deal with the effects of varying reference environment temperature on the exergy efficiencies of HGHE1 and HGHE2. The results show that increasing reference environment temperature decreases the exergy efficiency in both HGHE1 and HGHE2. (author)

Influence of particle size in silo discharge

Directory of Open Access Journals (Sweden)

Gella Diego

2017-01-01

Full Text Available Recently Janda et al. [Phys. Rev. Lett. 108, 248001 (2012] reported an experimental study where it was measured the velocity and volume fraction fields of 1 mm diameter stainless steel beads in the exit of a two-dimensional silo. In that work, they proposed a new expression to predict the flow of granular media in silos which does not explicitly include the particle size as a parameter. Here, we study if effectively, there is not such influence of the particle size in the flux equations as well as investigate any possible effect in the velocity and volume fraction fields. To this end, we have performed high speed motion measurements of these magnitudes in a two-dimensional silo filled with 4 mm diameter beads of stainless steel, the same material than the previous works. A developed tracking program has been implemented to obtain at the same time both, the velocity and volume fraction. The final objective of this work has been to extend and generalize the theoretical framework of Janda et al. for all sizes of particles. We have found that the obtained functionalities are the same than in the 1 mm case, but the exponents and other fitting parameters are different.

Systemic model for the aid for operating of the reactor Siloe; Modelisation systeme pour l`aide a l`exploitation du reacteur de recherche Siloe

Energy Technology Data Exchange (ETDEWEB)

Royer, J.C.; Moulin, V.; Monge, F. [CEA Centre d`Etudes de Grenoble, 38 (France). Direction des Reacteurs Nucleaires; Baradel, C. [ITMI APTOR, 38 - Meylan (France)

1995-12-31

The Service of the Reactor Siloe (CEA/DRN/DRE/SRS), fully aware of the abilities and knowledge of his teams in the field of research reactor operating, has undertaken a project of knowledge engineering in this domain. The following aims have been defined: knowledge capitalization for the installation in order to insure its perenniality and valorization, elaboration of a project for the aid of the reactor operators. This article deals with the different actions by the SRS to reach the aims: realization of a technical model for the operation of the Siloe reactor, development of a knowledge-based system for the aid for operating. These actions based on a knowledge engineering methodology, SAGACE, and using industrial tools will lead to an amelioration of the security and the operating of the Siloe reactor. (authors). 13 refs., 7 figs.

In-situ grouting of the low-level radioactive waste disposal silos at ORNL's Solid Waste Storage Area Six

International Nuclear Information System (INIS)

Francis, C.W.; Farmer, C.D.; Stansfield, R.G.

1993-07-01

At Oak Ridge National Laboratory (ORNL), one method of solid low-level radioactive waste disposal has been disposed of in below-grade cylindrical concrete silos. Located in Solid Waste Storage Area 6 (SWSA 6), each silo measures 8 ft in diameter and 20 ft deep. Present day operations involve loading the silos with low-level radioactive waste and grouting the remaining void space with a particulate grout of low viscosity. Initial operations involving the disposal of wastes into the below-grade silos did not include the grouting process. Grouting was stated as a standard practice (in late 1988) after discovering that ∼75% of the silos accumulated water in the bottom of the silos in the ∼2 years after capping. Silo water (leachate) contained a wide range of types and concentrations of radionuclides. The migration of contaminated leachate out of the silo into adjoining soil and groundwater was considered to be a serious environmental concern. This report describes how a specially designed particulate-base grout was used to grout 54 silos previously filled with low-level radioactive waste. Grouting involved three steps: (1) silo preparation, (2) formulation and preparation of the grout mixture, and (3) injection of the grout into the silos. Thirty-five of the 54 silos grouted were equipped with a 3-in.-diam Polyvinyl Chloride (PVC) pipe used to monitor water levels in the silos. A method for rupturing the bottom section of these PVC wells was developed so that grout could be pumped to the bottom of those silos. Holes (2-in. diam) were drilled through the ∼18 in. thick concrete to fill the remaining 19 wells without the PVC monitoring wells. The formulation of grout injected into the silos was based on a Portland Type I cement, flyash, sand, and silica fume admixture. Compressive strength of grout delivered to SWSA6 during grouting operations averaged 1,808 lb/in 2 with a bulk density of 3,549 lb/yd 3

Feedback of the behaviour of a silo founded on a compressible soil improved by floating stone columns

Directory of Open Access Journals (Sweden)

Bahar Ramdane

2018-01-01

Full Text Available The coastal city of Bejaia, located 250 kilometers east of the capital Algiers, Algeria, is characterized by soft soils. The residual grounds encountered on the first 40 meters usually have a low bearing capacity, high compressibility, insufficient strength, and subject to the risk of liquefaction. These unfavorable soil conditions require deep foundations or soil improvement. Since late 1990s, stone columns technique is used to improve the weak soils of the harbor area of the city. A shallow raft foundation on soft soil improved by stone columns was designed for a heavy storage steel silo and two towers. The improvement of 18m depth have not reached the substratum located at 39m depth. The stresses transmitted to the service limit state are variable 73 to 376 kPa. A rigorous and ongoing monitoring of the evolution of loads in the silo and settlements of the soil was carried out during 1400 days that is from the construction of foundations in 2008 to 2012. After the loading of the silo in 2010, settlement occurred affecting the stability of the towers due to excessive differential settlements. Consequently, the towers were inclined and damaged the transporter. This paper presents and discusses the experience feedback of the behavior of these structures. Numerical calculations by finite elements have been carried and the results are compared with the measurements.

Cracked reinforced concrete walls of chimneys, silos and cooling towers as result of using formworks

Directory of Open Access Journals (Sweden)

Maj Marek

2018-01-01

Full Text Available There are presented in this paper some problems connected with reinforced concrete shell objects operation in the aggressive environment and built in method of formworks. Reinforced concrete chimneys, cooling towers, silos and other shells were built for decades. Durability of cracked shells are one of the most important parameters during process of designing, construction and exploitation of shells. Some reasons of appearance of horizontal and vertical cracks as temperature, pressure of stored material, live loads e.g. dynamic character of wind, moisture, influence of construction joints, thermal insulation, chemistry active environmental etc. reduce the carrying capacity of the walls. Formworks, as is occurred recently, are the reason for technological joints with leaking connection, imperfections of flexible formworks slabs and as result can initiate cracks. Cracked surface of this constructions causes decreasing capacity and lower the state of reliability. Horizontal, vertical cracks can caused corrosion of concrete and steel bars, decreasing stiffness of contraction, increasing of deflection and carbonation of concrete cover. Local and global imperfactions of concrete shells are increasing according to greater number of cracks...

Disposal facility in Olkiluoto, description of above ground facilities in tunnel transport alternative

International Nuclear Information System (INIS)

Kukkola, T.

2006-11-01

The above ground facilities of the disposal plant on the Olkiluoto site are described in this report as they will be when the operation of the disposal facility starts in the year 2020. The disposal plant is visualised on the Olkiluoto site. Parallel construction of the deposition tunnels and disposal of the spent fuel canisters constitute the principal design basis of the disposal plant. The annual production of disposal canisters for spent fuel amounts to about 40. Production of 100 disposal canisters has been used as the capacity basis. Fuel from the Olkiluoto plant and from the Loviisa plant will be encapsulated in the same production line. The disposal plant will require an area of about 15 to 20 hectares above ground level. The total building volume of the above ground facilities is about 75000 m 3 . The purpose of the report is to provide the base for detailed design of the encapsulation plant and the repository spaces, as well as for coordination between the disposal plant and ONKALO. The dimensioning bases for the disposal plant are shown in the Tables at the end of the report. The report can also be used as a basis for comparison in deciding whether the fuel canisters are transported to the repository by a lift or a by vehicle along the access tunnel. (orig.)

Disposal facility in olkiluoto, description of above ground facilities in lift transport alternative

International Nuclear Information System (INIS)

Kukkola, T.

2006-11-01

The above ground facilities of the disposal plant on the Olkiluoto site are described in this report as they will be when the operation of the disposal facility starts in the year 2020. The disposal plant is visualised on the Olkiluoto site. Parallel construction of the deposition tunnels and disposal of the spent fuel canisters constitute the principal design basis of the disposal plant. The annual production of disposal canisters for spent fuel amounts to about 40. Production of 100 disposal canisters has been used as the capacity basis. Fuel from the Olkiluoto plant and from the Loviisa plant will be encapsulated in the same production line. The disposal plant will require an area of about 15 to 20 hectares above ground level. The total building volume of the above ground facilities is about 75000 m 3 . The purpose of the report is to provide the base for detailed design of the encapsulation plant and the repository spaces, as well as for coordination between the disposal plant and ONKALO. The dimensioning bases for the disposal plant are shown in the Tables at the end of the report. The report can also be used as a basis for comparison in deciding whether the fuel canisters are transported to the repository by a lift or by a vehicle along the access tunnel. (orig.)

Design, construction and performance of the clay-based isolation of the SFR silo

Energy Technology Data Exchange (ETDEWEB)

Pusch, Roland [Geodevelopment AB, Lund (Sweden)

2003-09-01

The report describes the host rock performance, recording systems, silo movement, and performance of the wall filling and recording systems. Recommendations for future performance checking are given as well. The measurements of rock movements show that creep is very limited but that instantaneous block movements may have taken place soon after the excavation. Such movements may occur in future as a result of creep-induced stress accumulation, or generated by earthquakes. One cannot draw safe conclusions concerning the magnitude and direction of the vertical component of the strain of the cavern wall, which largely determines the accuracy of silo settlement recordings made by use of reference bolts anchored in the walls. However, it is reasonable to believe that the net movement is directed downwards and amounts at a couple of hundred micrometers to date. The initial settlement of the silo was somewhat faster than predicted while there is rather good agreement between actual and predicted settlement of the silo top for the period 1991 to 1997 when the waste loading rate was slightly below the assumed lower limit. From 1997 the annual waste loading rate dropped by about 50 % of this limit and gave a theoretical overestimation of the settlement by about 15 %. Considering the uncertainties and conservatism in selecting parameter values for the calculations it can be stated that the agreement between the predicted and actual subsidence of the silo top is acceptable. Major conclusions from the analysis are that the dominant part of the silo top settlement is caused by compression of the bottom bed and that this compression and the silo top subsidence are within the initially assumed ranges. The analysis can be taken as a basis of the design of the future top fill with respect to the desired continuity of the silo/top fill/rock system. The pressure of the wall fill on the silo and rock has reached a maximum value of 100 kPa, which equals the lower limit for highly

Design, construction and performance of the clay-based isolation of the SFR silo

International Nuclear Information System (INIS)

Pusch, Roland

2003-09-01

The report describes the host rock performance, recording systems, silo movement, and performance of the wall filling and recording systems. Recommendations for future performance checking are given as well. The measurements of rock movements show that creep is very limited but that instantaneous block movements may have taken place soon after the excavation. Such movements may occur in future as a result of creep-induced stress accumulation, or generated by earthquakes. One cannot draw safe conclusions concerning the magnitude and direction of the vertical component of the strain of the cavern wall, which largely determines the accuracy of silo settlement recordings made by use of reference bolts anchored in the walls. However, it is reasonable to believe that the net movement is directed downwards and amounts at a couple of hundred micrometers to date. The initial settlement of the silo was somewhat faster than predicted while there is rather good agreement between actual and predicted settlement of the silo top for the period 1991 to 1997 when the waste loading rate was slightly below the assumed lower limit. From 1997 the annual waste loading rate dropped by about 50 % of this limit and gave a theoretical overestimation of the settlement by about 15 %. Considering the uncertainties and conservatism in selecting parameter values for the calculations it can be stated that the agreement between the predicted and actual subsidence of the silo top is acceptable. Major conclusions from the analysis are that the dominant part of the silo top settlement is caused by compression of the bottom bed and that this compression and the silo top subsidence are within the initially assumed ranges. The analysis can be taken as a basis of the design of the future top fill with respect to the desired continuity of the silo/top fill/rock system. The pressure of the wall fill on the silo and rock has reached a maximum value of 100 kPa, which equals the lower limit for highly

Chapter 6: Above Ground Deterioration of Wood and Wood-Based Materials

Science.gov (United States)

Grant Kirker; Jerrold Winandy

2014-01-01

Wood as a material has unique properties that make it ideal for above ground exposure in a wide range of structural and non-strucutral applications. However, no material is without limitations. Wood is a bio-polymer which is subject to degradative processes, both abiotic and biotic. This chapter is a general summary of the abiotic and biotic factors that impact service...

Confined granular flow in silos experimental and numerical investigations

CERN Document Server

Tejchman, Jacek

2013-01-01

  During confined flow of bulk solids in silos some characteristic phenomena can be created, such as: —         sudden and significant increase of wall stresses, —         different flow patterns, —         formation and propagation of wall and interior shear zones, —         fluctuation of pressures and, —         strong autogenous dynamic effects. These phenomena have not been described or explained in detail yet. The main intention of the experimental and theoretical research presented in this book is to explain the above mentioned phenomena in granular bulk solids and to describe them with numerical FE models verified by experimental results.

Simulation study of the discharge characteristics of silos with cohesive particles

Science.gov (United States)

Hund, David; Weis, Dominik; Hesse, Robert; Antonyuk, Sergiy

2017-06-01

In many industrial applications the silo for bulk materials is an important part of an overall process. Silos are used for instance to buffer intermediate products to ensure a continuous supply for the next process step. This study deals with the discharging behaviour of silos containing cohesive bulk solids with particle sizes in the range of 100-500 μm. In this contribution the TOMAS [1,2] model developed for stationary and non-stationary discharging of a convergent hopper is verified with experiments and simulations using the Discrete Element Method. Moreover the influence of the cohesion of the bulk solids on the discharge behaviour is analysed by the simulation. The simulation results showed a qualitative agreement with the analytical model of TOMAS.

Stochastic stresses in granular matter simulated by dripping identical ellipses into plane silo

DEFF Research Database (Denmark)

Berntsen, Kasper Nikolaj; Ditlevsen, Ove Dalager

2000-01-01

A two-dimensional silo pressure model-problem is investigated by molecular dynamics simulations. A plane silo container is filled by a granular matter consisting of congruent elliptic particles dropped one by one into the silo. A suitable energy absorbing contact force mechanism is activatedduring...... the granular matter in the silo are compared to thesolution of a stochastic equilibrium differential equation. In this equation the stochasticity source is a homogeneouswhite noise gamma-distributed side pressure factor field along the walls. This is a generalization of the deterministic side pressure factor...... proposed by Janssen in 1895. The stochastic Janssen factor model is shown to be fairly consistentwith the observations from which the mean and the intensity of the white noise is estimated by the method of maximumlikelihood using the properties of the gamma-distribution. Two wall friction coefficients...

PRELIMINARY NOTE ON FODDER PLANT CONSERVATION IN TRENCH TYPE SILOS NOTAS PRELIMINARES SOBRE CONSERVAÇÃO DE FORRAGENS EM SILOS DO TIPO TRINCHEIRA

Directory of Open Access Journals (Sweden)

Anatoly Kravchenko

2007-09-01

Full Text Available

This study has the objective of evaluating the quality of silage (Napier, 60%; sorghum, 30%; and sugar-cane, 10% conserved in trench-silos. The silos were built with side and back walls made of bricks, with no waterproof or revetment process. The floor was in direct contact with the soil, and the forage was distributed in 25cm-layers and compressed with the use of a tire tractor. The biggest losses, caused by ascetic and butyric fermentation, harmful to the cattle, took place close to the walls, due to a lack of compactness and a direct contact between the forage and the soil. The poor roof also allowed the penetration of water and other agents responsible for the formation of butyric acid. It was concluded that the waterproof process is the main factor in the desirable fermentation and conservation of the silage.

Este trabalho tem como objetivo avaliar a qualidade da silagem - Napier (60%, sorgo (30% e cana (10% - conservada em silos tipo trincheira. Os silos foram construídos com paredes de tijolos nas laterais e no fundo, sem impermeabilização ou revestimento. O piso ficou em contato direto com o solo. A forragem foi distribuída em camadas de 25 cm e comprimida com trator de pneu. As perdas maiores, decorrentes das fermentações acética e butírica, prejudiciais ao rebanho, ocorreram junto às paredes, por falta de compactação e pelo contato direto da forragem com o solo. A má cobertura também favoreceu a penetração de água e os agentes formadores de ácido butírico. Concluiu-se que a impermeabilização é o fator principal para uma fermentação e conservação desejável da silagem.

PALAVRAS-CHAVE: Silo; forragem; Sorgum; Penisetum.

Modelling the pressurization induced by solar radiation on above ground installations of LPG pipeline systems

Science.gov (United States)

Leporini, M.; Terenzi, A.; Marchetti, B.; Giacchetta, G.; Polonara, F.; Corvaro, F.; Cocci Grifoni, R.

2017-11-01

Pipelining Liquefied Petroleum Gas (LPG) is a mode of LPG transportation more environmentally-friendly than others due to the lower energy consumption and exhaust emissions. Worldwide, there are over 20000 kilometers of LPG pipelines. There are a number of codes that industry follows for the design, fabrication, construction and operation of liquid LPG pipelines. However, no standards exist to modelling particular critical phenomena which can occur on these lines due to external environmental conditions like the solar radiation pressurization. In fact, the solar radiation can expose above ground pipeline sections at pressure values above the maximum Design Pressure with resulting risks and problems. The present work presents an innovative practice suitable for the Oil & Gas industry to modelling the pressurization induced by the solar radiation on above ground LPG pipeline sections with the application to a real case.

Above Ground Biomass-carbon Partitioning, Storage and Sequestration in a Rehabilitated Forest, Bintulu, Sarawak, Malaysia

International Nuclear Information System (INIS)

Kueh, J.H.R.; Majid, N.M.A.; Seca, G.; Ahmed, O.H.

2013-01-01

Forest degradation and deforestation are some of the major global concerns as it can reduce forest carbon storage and sequestration capacity. Forest rehabilitation on degraded forest areas has the potential to improve carbon stock, hence mitigate greenhouse gases emission. However, the carbon storage and sequestration potential in a rehabilitated tropical forest remains unclear due to the lack of information. This paper reports an initiative to estimate biomass-carbon partitioning, storage and sequestration in a rehabilitated forest. The study site was at the UPM-Mitsubishi Corporation Forest Rehabilitation Project, UPM Bintulu Sarawak Campus, Bintulu, Sarawak. A plot of 20 x 20 m 2 was established each in site 1991 (Plot 1991), 1999 (Plot 1999) and 2008 (Plot 2008). An adjacent natural regenerating secondary forest plot (Plot NF) was also established for comparison purposes. The results showed that the contribution of tree component biomass/ carbon to total biomass/ carbon was in the order of main stem > branch > leaf. As most of the trees were concentrated in diameter size class = 10 cm for younger rehabilitated forests, the total above ground biomass/ carbon was from this class. These observations suggest that the forests are in the early successional stage. The total above ground biomass obtained for the rehabilitated forest ranged from 4.3 to 4,192.3 kg compared to natural regenerating secondary forest of 3,942.3 kg while total above ground carbon ranged from 1.9 to 1,927.9 kg and 1,820.4 kg, respectively. The mean total above ground biomass accumulated ranged from 1.3 x 10 -2 to 20.5 kg/ 0.04 ha and mean total carbon storage ranged from 5.9 x 10 -3 to 9.4 kg/ 0.04 ha. The total CO 2 sequestrated in rehabilitated forest ranged from 6.9 to 7,069.1 kg CO 2 / 0.04 ha. After 19 years, the rehabilitated forest had total above ground biomass and carbon storage comparable to the natural regeneration secondary forest. The forest rehabilitated activities have the

Dry matter losses of grass, lucerne and maize silages in bunker silos

Directory of Open Access Journals (Sweden)

Brigitte Koehler

2013-03-01

Full Text Available An efficient feed management is important for a sustainable and economic agricultural production. One of the main points for improving the efficiency is the reduction of feed losses. In the present investigation the dry matter (DM losses of grass, lucerne and maize silages in farm scaled bunker silos were analysed. The method of determining DM losses was the total-in versus total-out DM mass flow of the silos, including the determination of DM content and other silage parameters via manual sampling. The results taken from 48 silos showed on average for all investigated crops 9–12% of DM losses. Density and feed out rate showed a negative correlation to DM losses in maize silages. According to the applied method for determining DM losses on farm scale, a guideline of 8% can be suggested for maximum DM losses in bunker silos for grass and maize silages. The described method seems to be applicable for improving the feed management by using largely automated measurements on the harvest and feeding side.

Cleanup Progress on High Hazard Legacy Facilities at Sellafield: Pile Fuel Cladding Silo

International Nuclear Information System (INIS)

Skilbeck, D.

2006-01-01

This facility was constructed in the 1940's as the original dry storage silo for Intermediate Level Waste (ILW) arising from the Windscale Pile Reactors. Subsequently it was used as the main storage facility for all ILW arising from the Sellafield operation. It was operated until it became full and the Magnox Swarf Storage Silos were constructed in the mid 1960's. A systematic and As Low As Reasonably Practicable (ALARP) risk reduction approach has been adopted at Sellafield to address issues in order of risk magnitude. Prior to being in a position to retrieve stored wastes it has been necessary to improve the overall safety performance of the silo. This has involved installing new fire prevention systems, improving structural integrity, clearing waste from the Transfer Tunnel, and improving overall seismic performance. A major step towards reducing the overall risk profile of this facility has been to seal the six charge holes in the Transfer Tunnel, that were used for tipping the waste into the silo compartments during operations. This also enabled the silo Transfer Tunnel to be removed. Overall this work has proved that significant cleanup can be performed safely and successfully, in one of the most hazardous environments at Sellafield. (authors)

An assessment of temperature history on concrete silo dry storage system for CANDU spent fuel

International Nuclear Information System (INIS)

Lee, Dong-Gyu; Sung, Nak-Hoon; Park, Jea-Ho; Chung, Sung-Hwan

2016-01-01

Highlights: • We performed thermal analysis to predict the temperature distribution in the concrete silo. • Thermal analysis of the concrete silo was based on CFD code. • Temperature distribution and history for storage period was presented. • Thermal analysis results and test results agreed well. • The correlations can predict the maximum fuel temperature over storage period. - Abstract: Concrete silo is a dry storage system for spent fuel generated from CANDU reactors. The silo is designed to remove passively the decay heat from spent fuel, as well as to secure the integrity of spent fuel during storage period. Dominant heat transfer mechanisms must be characterized and validated for the thermal analysis model of the silo, and the temperature history along storage period could be determined by using the validated thermal analysis model. Heat transfer characteristics on the interior and exterior of fuel basket in the silo were assessed to determine the temperature history of silo, which is necessary for evaluating the long-term degradation behavior of CANDU spent fuel stored in the silo. Also a methodology to evaluate the temperature history during dry storage period was proposed in this study. A CFD model of fuel basket including fuel bundles was suggested and temperature difference correlation between fuel bundles and silo’s internal member, as a function of decay heat of fuel basket considering natural convection and radiation heat transfer, was deduced. Temperature difference between silo’s internal cavity and ambient air was determined by using a concept of thermal resistance, which was validated by CFD analysis. Fuel temperature was expressed as a function of ambient temperature and decay heat of fuel basket in the correlation, and fuel temperature along storage period was determined. Therefore, it could be used to assess the degradation behavior of spent fuel by applying the degradation mechanism expressed as a function of spent fuel

Cathodic protection for the bottoms of above ground storage tanks

Energy Technology Data Exchange (ETDEWEB)

Mohr, John P. [Tyco Adhesives, Norwood, MA (United States)

2004-07-01

Impressed Current Cathodic Protection has been used for many years to protect the external bottoms of above ground storage tanks. The use of a vertical deep ground bed often treated several bare steel tank bottoms by broadcasting current over a wide area. Environmental concerns and, in some countries, government regulations, have introduced the use of dielectric secondary containment liners. The dielectric liner does not allow the protective cathodic protection current to pass and causes corrosion to continue on the newly placed tank bottom. In existing tank bottoms where inadequate protection has been provided, leaks can develop. In one method of remediation, an old bottom is covered with sand and a double bottom is welded above the leaking bottom. The new bottom is welded very close to the old bottom, thus shielding the traditional cathodic protection from protecting the new bottom. These double bottoms often employ the use of dielectric liner as well. Both the liner and the double bottom often minimize the distance from the external tank bottom. The minimized space between the liner, or double bottom, and the bottom to be protected places a challenge in providing current distribution in cathodic protection systems. This study examines the practical concerns for application of impressed current cathodic protection and the types of anode materials used in these specific applications. One unique approach for an economical treatment using a conductive polymer cathodic protection method is presented. (author)

Evaluation of Sentinel-1A Data For Above Ground Biomass Estimation in Different Forests in India

Science.gov (United States)

Vadrevu, Krishna Prasad

2017-01-01

Use of remote sensing data for mapping and monitoring of forest biomass across large spatial scales can aid in addressing uncertainties in carbon cycle. Earlier, several researchers reported on the use of Synthetic Aperture Radar (SAR) data for characterizing forest structural parameters and the above ground biomass estimation. However, these studies cannot be generalized and the algorithms cannot be applied to all types of forests without additional information on the forest physiognomy, stand structure and biomass characteristics. The radar backscatter signal also saturates as forest parameters such as biomass and the tree height increase. It is also not clear how different polarizations (VV versus VH) impact the backscatter retrievals in different forested regions. Thus, it is important to evaluate the potential of SAR data in different landscapes for characterizing forest structural parameters. In this study, the SAR data from Sentinel-1A has been used to characterize forest structural parameters including the above ground biomass from tropical forests of India. Ground based data on tree density, basal area and above ground biomass data from thirty-eight different forested sites has been collected to relate to SAR data. After the pre-processing of Sentinel 1-A data for radiometric calibration, geo-correction, terrain correction and speckle filtering, the variability in the backscatter signal in relation tree density, basal area and above biomass density has been investigated. Results from the curve fitting approach suggested exponential model between the Sentinel-1A backscatter versus tree density and above ground biomass whereas the relationship was almost linear with the basal area in the VV polarization mode. Of the different parameters, tree density could explain most of the variations in backscatter. Both VV and VH backscatter signals could explain only thirty and thirty three percent of variation in above biomass in different forest sites of India

Nitrogen mediates above-ground effects of ozone but not below-ground effects in a rhizomatous sedge

International Nuclear Information System (INIS)

Jones, M.L.M.; Hodges, G.; Mills, G.

2010-01-01

Ozone and atmospheric nitrogen are co-occurring pollutants with adverse effects on natural grassland vegetation. Plants of the rhizomatous sedge Carex arenaria were exposed to four ozone regimes representing increasing background concentrations (background-peak): 10-30, 35-55, 60-80 and 85-105 ppb ozone at two nitrogen levels: 12 and 100 kg N ha -1 yr -1 . Ozone increased the number and proportion of senesced leaves, but not overall leaf number. There was a clear nitrogen x ozone interaction with high nitrogen reducing proportional senescence in each treatment and increasing the ozone dose (AOT40) at which enhanced senescence occurred. Ozone reduced total biomass due to significant effects on root biomass. There were no interactive effects on shoot:root ratio. Rhizome tissue N content was increased by both nitrogen and ozone. Results suggest that nitrogen mediates above-ground impacts of ozone but not impacts on below-ground resource translocation. This may lead to complex interactive effects between the two pollutants on natural vegetation. - Nitrogen alters threshold of ozone-induced senescence, but not below-ground resource allocation.

EnviroAtlas - Above Ground Live Biomass Carbon Storage for the Conterminous United States- Forested

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset includes the average above ground live dry biomass estimate for the Watershed Boundary Dataset (WBD) 12-digit Hydrologic Unit (HUC) in kg/m...

Below- and above-ground effects of deadwood and termites in plantation forests

Science.gov (United States)

Michael D. Ulyshen; Richard Shefferson; Scott Horn; Melanie K. Taylor; Bryana Bush; Cavell Brownie; Sebastian Seibold; Michael S. Strickland

2017-01-01

Deadwood is an important legacy structure in managed forests, providing continuity in shelter and resource availability for many organisms and acting as a vehicle by which nutrients can be passed from one stand to the next following a harvest. Despite existing at the interface between below- and above-ground systems, however, much remains unknown about the role woody...

Systemic model for the aid for operating of the reactor Siloe

International Nuclear Information System (INIS)

Royer, J.C.; Moulin, V.; Monge, F.

1995-01-01

The Service of the Reactor Siloe (CEA/DRN/DRE/SRS), fully aware of the abilities and knowledge of his teams in the field of research reactor operating, has undertaken a project of knowledge engineering in this domain. The following aims have been defined: knowledge capitalization for the installation in order to insure its perenniality and valorization, elaboration of a project for the aid of the reactor operators. This article deals with the different actions by the SRS to reach the aims: realization of a technical model for the operation of the Siloe reactor, development of a knowledge-based system for the aid for operating. These actions based on a knowledge engineering methodology, SAGACE, and using industrial tools will lead to an amelioration of the security and the operating of the Siloe reactor. (authors). 13 refs., 7 figs

Estimate of induced stress during filling and discharge of metallic silos for cement storage

Directory of Open Access Journals (Sweden)

Wilmer Bayona-Carvajal

2015-01-01

Full Text Available El presente artículo describe el análisis estructural realizado a un silo metálico que almacena cemento por medio de un modelo paramétrico desarrollado en el software de elementos finitos ANSYS APDL, las presiones de llenado y vaciado que el material ejerce sobre las paredes del silo se determinan basados en la normativa del Eurocódigo EN 1991-4. El modelo se realiza con elementos tipos cáscara permitiendo que su estructura se ajuste que la geometría cilíndrica y cónica del silo. Se explica cada una de las fases involucradas en el desarrollo del modelo y se hace un análisis detallado de los resultados arrojados por el software, se evalúan diferentes modelos variando los espesores de lámina con el fin de seleccionar el más adecuado. También se analizan los resultados obtenidos cuando la tolva del silo cambia su ángulo de inclinación y se revisa el comportamiento que tiene el silo cuando es analizado en conjunto con su estructura soporte.

Long-term above-ground biomass production in a red oak-pecan agroforestry system

Science.gov (United States)

Agroforestry systems have widely been recognized for their potential to foster long-term carbon sequestration in woody perennials. This study aims to determine the above-ground biomass in a 16-year-old red oak (Quercus rubra) - pecan (Carya illinoinensis) silvopastoral planting (141 and 53 trees ha-...

Implementing 10 CFR 830 at the FEMP Silos: Nuclear Health and Safety Plans as Documented Safety Analysis

International Nuclear Information System (INIS)

Fisk, Patricia; Rutherford, Lavon

2003-01-01

The objective of the Silos Project at the Fernald Closure Project (FCP) is to safely remediate high-grade uranium ore residues (Silos 1 and 2) and metal oxide residues (Silo 3). The evolution of Documented Safety Analyses (DSAs) for these facilities has reflected the changes in remediation processes. The final stage in silos DSAs is an interpretation of 10 CFR 830 Safe Harbor Requirements that combines a Health and Safety Plan with nuclear safety requirements. This paper will address the development of a Nuclear Health and Safety Plan, or N-HASP

Solar grain drier associated with underground silo; Secador solar para graos associado a silo subterraneo

Energy Technology Data Exchange (ETDEWEB)

Braga, C.A.S.; Armond, G.; Oliveira, G.M. da; Correa, H.G.; Moreira, C.A.; Martins, F.P.

1992-12-31

This paper refers to the design and test of a system including a drier with solar heating and an underground silo for grain storage intend for small farms. The tests showed good performance of the system. Three tons of moist corn were dried. Drying time and area were reduced by 14 and 90% respectively when compared with the traditional drying on brick flat surfaces. (author) 8 refs., 11 figs., 3 tabs.

Successful range-expanding plants experience less above-ground and below-ground enemy impact.

Science.gov (United States)

Engelkes, Tim; Morriën, Elly; Verhoeven, Koen J F; Bezemer, T Martijn; Biere, Arjen; Harvey, Jeffrey A; McIntyre, Lauren M; Tamis, Wil L M; van der Putten, Wim H

2008-12-18

Many species are currently moving to higher latitudes and altitudes. However, little is known about the factors that influence the future performance of range-expanding species in their new habitats. Here we show that range-expanding plant species from a riverine area were better defended against shoot and root enemies than were related native plant species growing in the same area. We grew fifteen plant species with and without non-coevolved polyphagous locusts and cosmopolitan, polyphagous aphids. Contrary to our expectations, the locusts performed more poorly on the range-expanding plant species than on the congeneric native plant species, whereas the aphids showed no difference. The shoot herbivores reduced the biomass of the native plants more than they did that of the congeneric range expanders. Also, the range-expanding plants developed fewer pathogenic effects in their root-zone soil than did the related native species. Current predictions forecast biodiversity loss due to limitations in the ability of species to adjust to climate warming conditions in their range. Our results strongly suggest that the plants that shift ranges towards higher latitudes and altitudes may include potential invaders, as the successful range expanders may experience less control by above-ground or below-ground enemies than the natives.

The effect of cassava-based bioethanol production on above-ground carbon stocks: A case study from Southern Mali

International Nuclear Information System (INIS)

Vang Rasmussen, Laura; Rasmussen, Kjeld; Birch-Thomsen, Torben; Kristensen, Søren B.P.; Traoré, Oumar

2012-01-01

Increasing energy use and the need to mitigate climate change make production of liquid biofuels a high priority. Farmers respond worldwide to this increasing demand by converting forests and grassland into biofuel crops, but whether biofuels offer carbon savings depends on the carbon emissions that occur when land use is changed to biofuel crops. This paper reports the results of a study on cassava-based bioethanol production undertaken in the Sikasso region in Southern Mali. The paper outlines the estimated impacts on above-ground carbon stocks when land use is changed to increase cassava production. The results show that expansion of cassava production for bioethanol will most likely lead to the conversion of fallow areas to cassava. A land use change from fallow to cassava creates a reduction in the above-ground carbon stocks in the order of 4–13 Mg C ha −1 , depending on (a) the age of the fallow, (b) the allometric equation used and (c) whether all trees are removed or the larger, useful trees are preserved. This ‘carbon debt’ associated with the above-ground biomass loss would take 8–25 years to repay if fossil fuels are replaced with cassava-based bioethanol. - Highlights: ► Demands for biofuels make production of cassava-based bioethanol a priority. ► Farmers in Southern Mali are likely to convert fallow areas to cassava production. ► Converting fallow to cassava creates reductions in above-ground carbon stocks. ► Estimates of carbon stock reductions include that farmers preserve useful trees. ► The carbon debt associated with above-ground biomass loss takes 8–25 years to repay.

Who's worried about turkeys? How 'organisational silos' impede zoonotic disease surveillance.

Science.gov (United States)

Jerolmack, Colin

2013-02-01

Though emerging infectious diseases ignore boundaries between species, the agencies that respond to them do not. Based on interviews with state and federal epidemiologists, veterinarians, and physicians and on case studies of disease events, this article examines how the jurisdictional and cultural divides that exist among human and animal health agencies hinder efforts to successfully contain species-jumping diseases (zoonoses). I argue that newly emergent zoonoses make these agencies' organisational cultures function as silos because the institutionalised thinking and practices developed to address the diseases that traditionally concerned each agency constrain members from building the inter-organisational bridges required to manage the latest 'hybrid' diseases. The silo effect is evident both across the human-animal health divide and within the landscape of animal health, as agencies that monitor livestock and wildlife follow distinct and sometimes competing agendas. The article also touches on moments of inter-agency cooperation in order to specify how health practitioners can begin making connections between 'organisational silos'. This article encourages sociologists of health to explore the crucial link between animal and human health; and it introduces the concept of organisational silos to capture the relational dilemmas that arise when a 'hybrid' problem systemically links agencies with disparate organisational cultures. © 2012 The Author. Sociology of Health & Illness © 2012 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.

Silo effect a prominence factor to decrease efficiency of pharmaceutical industry.

Science.gov (United States)

Vatanpour, Hossein; Khorramnia, Atoosa; Forutan, Naghmeh

2013-01-01

To be sure, all the industries try to be involved in globalization with a constant trend to find out ways to increase productivity across different functions within an organization to maintain competitive advantage world. Pharmaceutical industries are not exceptional and further are based on fragmentation. So these kind of companies need to cope with several barriers such as silo mentality that may affect efficiency of their business activity. Due to eliminate a part of resources such as raw materials, new molecule developed, financial and human resources and so on, companies can gradually loss their competitive potentials in the market and increase their expenses. Furthermore, to avoid any business disturbances in financially connected companies due to silo effect, they should arrange their management to integrated organization form. Otherwise, actions taken by one business member of the chain can influence the profitability of all the other members in the chain. That is why recently supply chain has generated much interest in many business units. In this paper, it has been tried to investigate the different aspects of silo effect which can affect integrate supply chain. Finally, a fluent communication, high level of information exchange, fragmentation management, cross-functional control in a supply chain management format are needed to reduce or control silo effect within entire chain of the holding company by Supply chain management.

Fire and fire extinguishment in silos. An experimental study[Storage of wood fuel pellets]; Brand och brandslaeckning i siloanlaeggningar. En experimentell studie

Energy Technology Data Exchange (ETDEWEB)

Persson, Henry; Blomqvist, Per; Zhenghua Yan

2007-01-15

A series of four tests have been conducted with wood pellets stored in a reduced size silo. The tests were conducted in order to increase the knowledge on fire development, detection and extinction technique in silo fires. The project originated from a pre-study on the extinction of silo fires made for the Swedish Rescue Service Agency (SRV). The test silo was built of concrete rings, had a diameter of 1 m, and a height of almost 6 m, which gave a volume of 4.4 m{sup 3}. The silo was filled with wood pellets up to a height of 5 m. A local auto ignition was imitated by a coiled heating wire placed in the pellet bulk centrally in the silo and a self sustaining pyrolysis zone was established within one hour. The silo was instrumented with almost 100 thermocouples as a mean to follow the development of the pyrolysis zone and later the efficiency of the extinguishment. Gas analyses were further made, both in the top of the silo, and at four different levels in the pellet bulk. After 30 hours the extinguishment was initiated using nitrogen (N{sub 2}) and carbon dioxide (CO{sub 2}), respectively. The gas was injected into the bottom of the silo. Two tests were also conducted where gas injection was combined foam application in the top of the silo. The tests showed that the pyrolysis zone preferably spreads downwards in the silo, while moisture and pyrolysis gases form a wave that slowly spreads upwards. It was difficult to detect the fire before the main 'gas wave' reached the pellet surface in the silo top, and detection time was about 20 hours in these tests. The spread of the pyrolysis zone, downward, was even slower. The slow development is probably an explanation of why real silo fires often are rather extensive once discovered. Inerting the silo with either nitrogen or carbon dioxide worked out well in the tests. The gas must be in gas phase and slowly introduced into the silo, as close to the bottom as possible. An efficient extinction implies an air

Land-use type and intensity differentially filter traits in above- and below-ground arthropod communities.

Science.gov (United States)

Birkhofer, Klaus; Gossner, Martin M; Diekötter, Tim; Drees, Claudia; Ferlian, Olga; Maraun, Mark; Scheu, Stefan; Weisser, Wolfgang W; Wolters, Volkmar; Wurst, Susanne; Zaitsev, Andrey S; Smith, Henrik G

2017-05-01

Along with the global decline of species richness goes a loss of ecological traits. Associated biotic homogenization of animal communities and narrowing of trait diversity threaten ecosystem functioning and human well-being. High management intensity is regarded as an important ecological filter, eliminating species that lack suitable adaptations. Below-ground arthropods are assumed to be less sensitive to such effects than above-ground arthropods. Here, we compared the impact of management intensity between (grassland vs. forest) and within land-use types (local management intensity) on the trait diversity and composition in below- and above-ground arthropod communities. We used data on 722 arthropod species living above-ground (Auchenorrhyncha and Heteroptera), primarily in soil (Chilopoda and Oribatida) or at the interface (Araneae and Carabidae). Our results show that trait diversity of arthropod communities is not primarily reduced by intense local land use, but is rather affected by differences between land-use types. Communities of Auchenorrhyncha and Chilopoda had significantly lower trait diversity in grassland habitats as compared to forests. Carabidae showed the opposite pattern with higher trait diversity in grasslands. Grasslands had a lower proportion of large Auchenorrhyncha and Carabidae individuals, whereas Chilopoda and Heteroptera individuals were larger in grasslands. Body size decreased with land-use intensity across taxa, but only in grasslands. The proportion of individuals with low mobility declined with land-use intensity in Araneae and Auchenorrhyncha, but increased in Chilopoda and grassland Heteroptera. The proportion of carnivorous individuals increased with land-use intensity in Heteroptera in forests and in Oribatida and Carabidae in grasslands. Our results suggest that gradients in management intensity across land-use types will not generally reduce trait diversity in multiple taxa, but will exert strong trait filtering within

Can above-ground ecosystem services compensate for reduced fertilizer input and soil organic matter in annual crops?

NARCIS (Netherlands)

van Gils, Stijn; van der Putten, Wim H; Kleijn, David

2016-01-01

1.Above-ground and below-ground environmental conditions influence crop yield by pollination, pest pressure, and resource supply. However, little is known about how interactions between these factors contribute to yield. Here, we used oilseed rape Brassica napus to test their effects on crop

Can above-ground ecosystem services compensate for reduced fertilizer input and soil organic matter in annual crops?

NARCIS (Netherlands)

Gils, van S.H.; Putten, van der W.H.; Kleijn, D.

2016-01-01

1.Above-ground and below-ground environmental conditions influence crop yield by pollination, pest pressure and resource supply. However, little is known about how interactions between these factors contribute to yield. Here, we used oilseed rape Brassica napus to test their effects on crop

Propagation of a whistler wave incident from above on the lower nighttime ionosphere

Directory of Open Access Journals (Sweden)

P. Bespalov

2017-05-01

Full Text Available The problems of reflection and transmission of a whistler wave incident in the nighttime ionosphere from above are considered. Numerical solution of the wave equations for a typical condition of the lower ionosphere is found. The solution area comprises both the region of strong wave refraction and a sharp boundary of the nighttime ionosphere (∼ 100 km. The energy reflection coefficient and horizontal wave magnetic field on the ground surface are calculated. The results obtained are important for analysis of the extremely low-frequency and very low-frequency (ELF–VLF emission phenomena observed from both the satellites and the ground-based observatories.

Vitrification of Simulated Fernald K-65 Silo Waste at Low Temperature

International Nuclear Information System (INIS)

Jantzen, C.M.; Pickett, J.B.

1998-01-01

Vitrification is the technology that has been chosen to solidify approximately 15,500 tons of geologic mill tailings at the Fernald Environmental Management Project (FEMP) in Fernald, Ohio. The geologic mill tailings are residues from the processing of pitchlende ore during 1949-1958. These waste residues are contained in silos in Operable Unit 4 (OU4) at the FEMP facility. Operable Unit 4 is one of five operable units at the FEMP. Operating Unit 4 consists of four concrete storage silos and their contents. Silos 1 and 2 contain K-65 mill tailing residues and a bentonite cap, Silo 3 contains non-radioactive metal oxides, and Silo 4 is empty. The K-65 residues contain radium, uranium, uranium daughter products, and heavy metals such as lead and barium.The K-65 waste leaches lead at greater than 100 times the allowable Environmental Protection Agency (EPA) Resource, Conservation, and Recovery Act (RCRA) concentration limits when tested by the Toxic Characteristic Leaching Procedure (TCLP). Vitrification was chosen by FEMP as the preferred technology for the Silos 1, 2, 3 wastes because the final waste form met the following criteria: controls radon emanation, eliminates the potential for hazardous or radioactive constituents to migrate to the aquifer below FEMP, controls the spread of radioactive particulates, reduces leachability of metals and radiological constituents, reduces volume of final wasteform for disposal, silo waste composition is favorable to vitrification, will meet current and proposed RCRA TCLP leaching criteria Glasses that melt at 1350 degrees C were developed by Pacific Northwest National Laboratory (PNNL) and glasses that melt between 1150-1350 degrees C were developed by the Vitreous State Laboratory (VSL) for the K-65 silo wastes. Both crucible studies and pilot scale vitrification studies were conducted by PNNL and VSL. Subsequently, a Vitrification Pilot Plant (VPP) was constructed at FEMP capable of operating at temperatures up to 1450

A Comparison of Two Above-Ground Biomass Estimation Techniques Integrating Satellite-Based Remotely Sensed Data and Ground Data for Tropical and Semiarid Forests in Puerto Rico

Science.gov (United States)

Two above-ground forest biomass estimation techniques were evaluated for the United States Territory of Puerto Rico using predictor variables acquired from satellite based remotely sensed data and ground data from the U.S. Department of Agriculture Forest Inventory Analysis (FIA)...

Luxury consumption of soil nutrients: a possible competitive strategy in above-ground and below-ground biomass allocation and root morphology for slow-growing arctic vegetation?

NARCIS (Netherlands)

Wijk, van M.T.; Williams, M.; Gough, L.; Hobbie, S.E.; Shaver, G.R.

2003-01-01

1 A field-experiment was used to determine how plant species might retain dominance in an arctic ecosystem receiving added nutrients. We both measured and modelled the above-ground and below-ground biomass allocation and root morphology of non-acidic tussock tundra near Toolik Lake, Alaska, after 4

Parametric design of silo steel framework of concrete mixing station based on the finite element method and MATLAB

Directory of Open Access Journals (Sweden)

Long Hui

2016-01-01

Full Text Available When the structure of the silo steel framework of concrete mixing station is designed, In most cases, the dimension parameters, shape parameters and position parameters of silo steel framework beams are changed as the productivity adjustment of the concrete mixing station, but the structure types of silo steel framework will remain the same. In order to acquire strength of silo steel framework rapidly and efficiently, it is need to provide specialized parametric strength computational software for engineering staff who does not understand the three-dimensional software such as PROE and finite element analysis software. By the finite element methods(FEM, the parametric stress calculation modal of the silo steel framework of concrete mixing station is established, which includes dimension parameters, shape parameters, position parameters and applied load parameters of each beams, and then the parametric calculation program is written with MATLAB. The stress equations reflect the internal relationship between the stress of the silo steel frames with the dimension parameters, shape parameters, position parameters and load parameters. Finally, an example is presented, the calculation results show the stress of all members and the size and location of the maximum stress, which agrees well with realistic cases.

The role of above-ground competition and nitrogen vs. phosphorus enrichment in seedling survival of common European plant species of semi-natural grasslands.

Directory of Open Access Journals (Sweden)

Tobias Ceulemans

Full Text Available Anthropogenic activities have severely altered fluxes of nitrogen and phosphorus in ecosystems worldwide. In grasslands, subsequent negative effects are commonly attributed to competitive exclusion of plant species following increased above-ground biomass production. However, some studies have shown that this does not fully account for nutrient enrichment effects, questioning whether lowering competition by reducing grassland productivity through mowing or herbivory can mitigate the environmental impact of nutrient pollution. Furthermore, few studies so far discriminate between nitrogen and phosphorus pollution. We performed a full factorial experiment in greenhouse mesocosms combining nitrogen and phosphorus addition with two clipping regimes designed to relax above-ground competition. Next, we studied the survival and growth of seedlings of eight common European grassland species and found that five out of eight species showed higher survival under the clipping regime with the lowest above-ground competition. Phosphorus addition negatively affected seven plant species and nitrogen addition negatively affected four plant species. Importantly, the negative effects of nutrient addition and higher above-ground competition were independent of each other for all but one species. Our results suggest that at any given level of soil nutrients, relaxation of above-ground competition allows for higher seedling survival in grasslands. At the same time, even at low levels of above-ground competition, nutrient enrichment negatively affects survival as compared to nutrient-poor conditions. Therefore, although maintaining low above-ground competition appears essential for species' recruitment, for instance through mowing or herbivory, these management efforts are likely to be insufficient and we conclude that environmental policies aimed to reduce both excess nitrogen and particularly phosphorus inputs are also necessary.

Diffusion of dust particles from a point-source above ground level

International Nuclear Information System (INIS)

Hassan, M.H.A.; Eltayeb, I.A.

1998-10-01

A pollutant of small particles is emitted by a point source at a height h above ground level in an atmosphere in which a uni-directional wind speed, U, is prevailing. The pollutant is subjected to diffusion in all directions in the presence of advection and settling due to gravity. The equation governing the concentration of the pollutant is studied with the wind speed and the different components of diffusion tensor are proportional to the distance above ground level and the source has a uniform strength. Adopting a Cartesian system of coordinates in which the x-axis lies along the direction of the wind velocity, the z-axis is vertically upwards and the y-axis completes the right-hand triad, the solution for the concentration c(x,y,z) is obtained in closed form. The relative importance of the components of diffusion along the three axes is discussed. It is found that for any plane y=constant (=A), c(x,y,z) is concentrated along a curve of ''extensive pollution''. In the plane A=0, the concentration decreases along the line of extensive pollution as we move away from the source. However, for planes A≅0, the line of extensive pollution possesses a point of accumulation, which lies at a nonzero value of x. As we move away from the plane A=0, the point of accumulation moves laterally away from the plane x=0 and towards the plane z=0. The presence of the point of accumulation is entirely due to the presence of lateral diffusion. (author)

Well drilling by rotary percussive drill above ground

International Nuclear Information System (INIS)

Sabatier, G.

1987-01-01

Originally, the Well Drilling Section of Cogema used only the diamond core drilling technique. The appearance of independent rotation for compressed air rock drills has led to the use and to the development of this drilling system, as a drill core is not indispensable, when the material of the search is radioactive. During the last few years, hydraulic drills have replaced the compressed air drills and have resulted in a very marked improvement: - of the penetration rates; - of the depth achieved. The Well Drilling Section of Cogema has to drill about 400 km per year with rock drills above ground and holds also the record for depth achieved with this technique, i.e. 400 m in granite. In France, the costs of these types of drilling are for the same depth of the order of one-quarter of the core drilling and half of the drilling with a down-the-hole drill. Cogema has greatly developed the types of well logging which now permits the extension of this type of drilling to the search for other materials than uranium [fr

Impacts of Jatropha-based biodiesel production on above and below-ground carbon stocks: A case study from Mozambique

International Nuclear Information System (INIS)

Vang Rasmussen, Laura; Rasmussen, Kjeld; Bech Bruun, Thilde

2012-01-01

The need to mitigate climate change makes production of liquid biofuels a high priority. Substituting fossil fuels by biodiesel produced from Jatropha curcas has gained widespread attention as Jatropha cultivation is claimed to offer green house gas emission reductions. Farmers respond worldwide to this increasing demand by converting forests into Jatropha, but whether Jatropha-based biodiesel offers carbon savings depends on the carbon emissions that occur when land use is changed to Jatropha. This paper provides an impact assessment of a small-scale Jatropha project in Cabo Delgado, Mozambique. The paper outlines the estimated impacts on above and below-ground carbon stocks when land use is changed to increase Jatropha production. The results show that expansion of Jatropha production will most likely lead to the conversion of miombo forest areas to Jatropha, which implies a reduction in above and below-ground carbon stocks. The carbon debts created by the land use change can be repaid by replacing fossil fuels with Jatropha-based biodiesel. A repayment time of almost two centuries is found with optimistic estimates of the carbon debt, while the use of pessimistic values results in a repayment time that approaches the millennium. - Highlights: ► Demands for biofuels make production of Jatropha-based biodiesel a priority. ► Farmers in Northern Mozambique are likely to convert un-logged miombo to Jatropha. ► Converting miombo to Jatropha creates reductions in above and below-ground carbon. ► It takes 187–966 years to repay emissions from above and below-ground carbon stocks.

Root herbivory indirectly affects above- and below-ground community members and directly reduces plant performance

NARCIS (Netherlands)

Barber, N.A.; Milano, N.J.; Kiers, E.T.; Theis, N.; Bartolo, V.; Hazzard, R.V.; Adler, L.S.

2015-01-01

There is a widespread recognition that above- and below-ground organisms are linked through their interactions with host plants that span terrestrial subsystems. In addition to direct effects on plants, soil organisms such as root herbivores can indirectly alter interactions between plants and other

Should the scope of human mixture risk assessment span legislative/regulatory silos for chemicals?

Science.gov (United States)

Evans, Richard M; Martin, Olwenn V; Faust, Michael; Kortenkamp, Andreas

2016-02-01

Current chemicals regulation operates almost exclusively on a chemical-by-chemical basis, however there is concern that this approach may not be sufficiently protective if two or more chemicals have the same toxic effect. Humans are indisputably exposed to more than one chemical at a time, for example to the multiple chemicals found in food, air and drinking water, and in household and consumer products, and in cosmetics. Assessment of cumulative risk to human health and/or the environment from multiple chemicals and routes can be done in a mixture risk assessment (MRA). Whilst there is a broad consensus on the basic science of mixture toxicology, the path to regulatory implementation of MRA within chemical risk assessment is less clear. In this discussion piece we pose an open question: should the scope of human MRA cross legislative remits or 'silos'? We define silos as, for instance, legislation that defines risk assessment practice for a subset of chemicals, usually on the basis of substance/product, media or process orientation. Currently any form of legal mandate for human MRA in the EU is limited to only a few pieces of legislation. We describe two lines of evidence, illustrated with selected examples, that are particularly pertinent to this question: 1) evidence that mixture effects have been shown for chemicals regulated in different silos and 2) evidence that humans are co-exposed to chemicals from different silos. We substantiate the position that, because there is no reason why chemicals allocated to specific regulatory silos would have non-overlapping risk profiles, then there is also no reason to expect that MRA limited only to chemicals within one silo can fully capture the risk that may be present to human consumers. Finally, we discuss possible options for implementation of MRA and we hope to prompt wider discussion of this issue. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Profile of the horizontal wind variance near the ground in near neutral flow – K-theory and the transport of the turbulent kinetic energy

Directory of Open Access Journals (Sweden)

S. Yahaya

2009-05-01

Full Text Available This paper deals with the characteristics of the atmospheric turbulent flow in the vicinity of the ground, and particularly with the profile of the horizontal wind variance. The study is based on experimental measurements performed with fast cup anemometers located near the ground at 5 different levels (from 0.25 to 4 m and sampled at 1 Hz. The experiment was carried over two agricultural plots with various tillage treatments in a fallow semiarid area (Central Aragon, Spain. The results of this study reveal that near the ground surface and under moderate wind, the horizontal wind variance logarithmically increases with height, in direct relationship with the friction velocity and the roughness length scale. A theoretical development has allowed us to link this behaviour to the modeling of the turbulent kinetic energy (TKE transport through the eddy diffusivity. Thus, the study proposes a formulation of the similarity universal function of the horizontal wind variance. Besides, the formulation offers a new method for the determination of the friction velocity and the roughness length scale and can be used for the evaluation of the TKE transport rate.

Above-ground biomass production and allometric relations of Eucalyptus globulus Labill. coppice plantations along a chronosequence in the central highlands of Ethiopia

International Nuclear Information System (INIS)

Zewdie, Mulugeta; Olsson, Mats; Verwijst, Theo

2009-01-01

Eucalyptus plantations are extensively managed for wood production in the central highlands of Ethiopia. Nevertheless, little is known about their biomass (dry matter) production, partitioning and dynamics over time. Data from 10 different Eucalyptus globulus stands, with a plantation age ranging from 11 to 60 years and with a coppice-shoot age ranging from 1 to 9 years were collected and analyzed. Above-ground tree biomass of 7-10 sampled trees per stand was determined destructively. Dry weights of tree components (W c ; leaves, twigs, branches, stembark, and stemwood) and total above-ground biomass (W a ) were estimated as a function of diameter above stump (D), tree height (H) and a combination of these. The best fits were obtained, using combinations of D and H. When only one explanatory variable was used, D performed better than H. Total above-ground biomass was linearly related to coppice-shoot age. In contrast a negative relation was observed between the above-ground biomass production and total plantation age (number of cutting cycles). Total above-ground biomass increased from 11 t ha -1 at a stand age of 1 year to 153 t ha -1 at 9 years. The highest dry weight was allocated to stemwood and decreased in the following order: stemwood > leaves > stembark > twigs > branches. The equations developed in this study to estimate biomass components can be applied to other Eucalyptus plantations under the assumption that the populations being studied are similar with regard to density and tree size to those for which the relationships were developed

Above-ground biomass production and allometric relations of Eucalyptus globulus Labill. coppice plantations along a chronosequence in the central highlands of Ethiopia

Energy Technology Data Exchange (ETDEWEB)

Zewdie, Mulugeta; Olsson, Mats; Verwijst, Theo [Swedish University of Agricultural Sciences, Department of Crop Production Ecology, P.O. Box 7043, 75007 Uppsala (Sweden)

2009-03-15

Eucalyptus plantations are extensively managed for wood production in the central highlands of Ethiopia. Nevertheless, little is known about their biomass (dry matter) production, partitioning and dynamics over time. Data from 10 different Eucalyptus globulus stands, with a plantation age ranging from 11 to 60 years and with a coppice-shoot age ranging from 1 to 9 years were collected and analyzed. Above-ground tree biomass of 7-10 sampled trees per stand was determined destructively. Dry weights of tree components (W{sub c}; leaves, twigs, branches, stembark, and stemwood) and total above-ground biomass (W{sub a}) were estimated as a function of diameter above stump (D), tree height (H) and a combination of these. The best fits were obtained, using combinations of D and H. When only one explanatory variable was used, D performed better than H. Total above-ground biomass was linearly related to coppice-shoot age. In contrast a negative relation was observed between the above-ground biomass production and total plantation age (number of cutting cycles). Total above-ground biomass increased from 11 t ha{sup -1} at a stand age of 1 year to 153 t ha{sup -1} at 9 years. The highest dry weight was allocated to stemwood and decreased in the following order: stemwood > leaves > stembark > twigs > branches. The equations developed in this study to estimate biomass components can be applied to other Eucalyptus plantations under the assumption that the populations being studied are similar with regard to density and tree size to those for which the relationships were developed. (author)

Evaluation of ambient dose equivalent rates influenced by vertical and horizontal distribution of radioactive cesium in soil in Fukushima Prefecture

OpenAIRE

Malins, Alex; Kurikami, Hiroshi; Nakama, Shigeo; Saito, Tatsuo; Okumura, Masahiko; Machida, Masahiko; Kitamura, Akihiro

2015-01-01

The air dose rate in an environment contaminated with 134Cs and 137Cs depends on the amount, depth profile and horizontal distribution of these contaminants within the ground. This paper introduces and verifies a tool that models these variables and calculates ambient dose equivalent rates at 1 m above the ground. Good correlation is found between predicted dose rates and dose rates measured with survey meters in Fukushima Prefecture in areas contaminated with radiocesium from the Fukushima D...

Data from: Can above-ground ecosystem services compensate for reduced fertilizer input and soil organic matter in annual crops?

NARCIS (Netherlands)

Gils, van S.H.; Putten, van der W.H.; Kleijn, D.

2016-01-01

Above-ground and below-ground environmental conditions influence crop yield by pollination, pest pressure, and resource supply. However, little is known about how interactions between these factors contribute to yield. Here, we used oilseed rape Brassica napus to test their effects on crop yield. We

Estimation of Above Ground Biomass in a Tropical Mountain Forest in Southern Ecuador Using Airborne LiDAR Data

Directory of Open Access Journals (Sweden)

Víctor González-Jaramillo

2018-04-01

Full Text Available A reliable estimation of Above Ground Biomass (AGB in Tropical Mountain Forest (TMF is still complicated, due to fast-changing climate and topographic conditions, which modifies the forest structure within fine scales. The variations in vertical and horizontal forest structure are hardly detectable by small field plots, especially in natural TMF due to the high tree diversity and the inaccessibility of remote areas. Therefore, the present approach used remotely sensed data from a Light Detection and Ranging (LiDAR sensor in combination with field measurements to estimate AGB accurately for a catchment in the Andes of south-eastern Ecuador. From the LiDAR data, information about horizontal and vertical structure of the TMF could be derived and the vegetation at tree level classified, differentiated between the prevailing forest types (ravine forest, ridge forest and Elfin Forest. Furthermore, topographical variables (Topographic Position Index, TPI; Morphometric Protection Index, MPI were calculated by means of the high-resolution LiDAR data to analyse the AGB distribution within the catchment. The field measurements included different tree parameters of the species present in the plots, which were used to determine the local mean Wood Density (WD as well as the specific height-diameter relationship to calculate AGB, applying regional scale modelling at tree level. The results confirmed that field plot measurements alone cannot capture completely the forest structure in TMF but in combination with high resolution LiDAR data, applying a classification at tree level, the AGB amount (Mg ha−1 and its distribution in the entire catchment could be estimated adequately (model accuracy at tree level: R2 > 0.91. It was found that the AGB distribution is strongly related to ridges and depressions (TPI and to the protection of the site (MPI, because high AGB was also detected at higher elevations (up to 196.6 Mg ha−1, above 2700 m, if the site is

Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host-parasite interactions.

Science.gov (United States)

Tao, Leiling; Gowler, Camden D; Ahmad, Aamina; Hunter, Mark D; de Roode, Jacobus C

2015-10-22

Host-parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host-parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host-parasite systems. © 2015 The Author(s).

Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host–parasite interactions

Science.gov (United States)

Tao, Leiling; Gowler, Camden D.; Ahmad, Aamina; Hunter, Mark D.; de Roode, Jacobus C.

2015-01-01

Host–parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host–parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host–parasite systems. PMID:26468247

Emergent Ising degrees of freedom above a double-stripe magnetic ground state

Science.gov (United States)

Zhang, Guanghua; Flint, Rebecca

2017-12-01

Double-stripe magnetism [Q =(π /2 ,π /2 )] has been proposed as the magnetic ground state for both the iron-telluride and BaTi2Sb2O families of superconductors. Double-stripe order is captured within a J1-J2-J3 Heisenberg model in the regime J3≫J2≫J1 . Intriguingly, besides breaking spin-rotational symmetry, the ground-state manifold has three additional Ising degrees of freedom associated with bond ordering. Via their coupling to the lattice, they give rise to an orthorhombic distortion and to two nonuniform lattice distortions with wave vector (π ,π ) . Because the ground state is fourfold degenerate, modulo rotations in spin space, only two of these Ising bond order parameters are independent. Here, we introduce an effective field theory to treat all Ising order parameters, as well as magnetic order, and solve it within a large-N limit. All three transitions, corresponding to the condensations of two Ising bond order parameters and one magnetic order parameter are simultaneous and first order in three dimensions, but lower dimensionality, or equivalently weaker interlayer coupling, and weaker magnetoelastic coupling can split the three transitions, and in some cases allows for two separate Ising phase transitions above the magnetic one.

The simultaneous discharge of liquid and grains from a silo

Science.gov (United States)

Cervantes-Álvarez, A. M.; Hidalgo-Caballero, S.; Pacheco-Vázquez, F.

2018-04-01

The flow rate of water through an orifice at the bottom of a container depends on the hydrostatic pressure whereas for a dry granular material it is nearly constant. But what happens during the simultaneous discharge of grains and liquid from a silo? By measuring the flow rate as a function of time, we found that (i) different regimes appear, going from the constant flow rate to a hydrostatic-like discharge depending on the aperture size and grain diameter, (ii) the mixed material is always discharged faster than dry grains but slower than liquid, (iii) for the mixture, the liquid level drops faster than the grain level, but they are always linearly proportional to one another, and (iv) a sudden growth in the flow rate happens during the transition from a biphasic discharge to a single phase discharge. These results are associated to the competition between the decrease in hydrostatic pressure above the granular bed and the hydrodynamic resistance. A model combining Darcy's law with Bernoulli and mass conservation equations is proposed, and the numerical results are in good agreement with experiments.

ABOVE AND BELOW GROUND INTERACTIONS IN THE AGROFORESTAL ASSOCIATION 'RED CEDAR-PERSIAN LIME-CHAYA'

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Jesús Mao Estanislao Aguilar-Luna

2011-05-01

Full Text Available Above and below ground interactions were analyzed in the agroforestal association 'red cedar-Persian lime-chaya', to know the initial optimum planting density (PD, in Quintana Roo, Mexico. Red cedar and Persian lime were placed in a 'Nelder' circle of 3154 m2 which consisted of 20 concentric circles alternating red cedars and Persian limes to 1.50 m apart and 10 plants per circle; chaya rectangular frame was set at 1.50 x 3.00 m, superimposed on the 'Nelder' circle. Defined eight PD 2602 to 3772 pl·ha-1 with 10 repetitions, to evaluate the length of main root (LMR, radical exploration range (RER, below ground interaction (BGI, plant height (PH, crown diameter (CD, above ground interaction (AGI and soil fertility (SF. The growth intraspecific he present statistical difference (P≤0.05 when moving from one PD to another PD, while the growth interespecific manifested different growth habit. The agroforestal association propitious in soil decreased phosphorous ±2 %, and increases organic matter ±14 % and nitrogen ±10 % on all PD. The BGI was increased in direct relation with the PD, reaching its highest value (64±5.8 % to 3772 pl·ha-1; the AGI also increased in direct relation with the PD, its highest value (52±3.1 % went to 3772 pl·ha-1; therefore, to higher PD increased BGI and AGI, at 20 months after planting.

Overview of Remote Retrieval Equipment and the Strategy for removal of Radon Bearing Waste from Silos 1 and 2 at the Fernald Site

International Nuclear Information System (INIS)

Rinker, Michael W.; Samuel, Todd J.

2001-01-01

This document provides an overview of the remote retrieval equipment and strategy for the retrieval of waste from Silos 1 and 2 at the Department of Energy's Fernald site in southwestern Ohio. The scope of this paper is limited to general descriptions of remote equipment specifically related in-silo retrieval. The retrieval strategy describes how the contractor team is planning to utilize the various remote subsystems to efficiently remove the waste from the silos from a philosophical standpoint as opposed to a procedural and operational standpoint. The retrieval strategy and approach is based upon the successful tank retrieval operations conducted at DOE's Oak Ridge and Hanford Sites. Lessons learned from these previous operations have been utilized in planning an approach for the Fernald Silo Retrieval Project. The equipment overview includes discussion of the retrieval system configurations together with descriptions of the robotic arm and retrieval end effectors, the conditioning and transfer pumping system, the sluicer and sluicing pump, as well as the debris retrieval system. A unique challenge being addressed as part of this project is the waste contents. Silos 1 and 2 contain two distinct layers of material that need to be retrieved. The first layer is a Bentonite (trade name BentogroutTM) cap that was placed in the silos to prevent radon migration into the dome space and out of the silos. The Bentonite layer varies, but in general it is approximately six inches deep in the center of the silo and thirty-six inches near the silo walls. The material may have dried out on the surface, and may still be wetted near the bottom of the bentonite layer. The K-65 ore tailings, which were slurried into the silos, are the remainder of the waste that is over 20' in depth. This paper provides an overview of the retrieval strategies, technologies, and techniques that will be used to safely and efficiently retrieve the waste from the Fernald Silos

Examining spectral properties of Landsat 8 OLI for predicting above-ground carbon of Labanan Forest, Berau

Science.gov (United States)

Suhardiman, A.; Tampubolon, B. A.; Sumaryono, M.

2018-04-01

Many studies revealed significant correlation between satellite image properties and forest data attributes such as stand volume, biomass or carbon stock. However, further study is still relevant due to advancement of remote sensing technology as well as improvement on methods of data analysis. In this study, the properties of three vegetation indices derived from Landsat 8 OLI were tested upon above-ground carbon stock data from 50 circular sample plots (30-meter radius) from ground survey in PT. Inhutani I forest concession in Labanan, Berau, East Kalimantan. Correlation analysis using Pearson method exhibited a promising results when the coefficient of correlation (r-value) was higher than 0.5. Further regression analysis was carried out to develop mathematical model describing the correlation between sample plots data and vegetation index image using various mathematical models.Power and exponential model were demonstrated a good result for all vegetation indices. In order to choose the most adequate mathematical model for predicting Above-ground Carbon (AGC), the Bayesian Information Criterion (BIC) was applied. The lowest BIC value (i.e. -376.41) shown by Transformed Vegetation Index (TVI) indicates this formula, AGC = 9.608*TVI21.54, is the best predictor of AGC of study area.

RESFRIAMENTO ARTIFICIAL E USO DE TERRA DE DIATOMÁCEA PARA O CONTROLE DE INSETOS EM GRÃOS DE TRIGO ARMAZENADOS EM SILOS DE CONCRETO

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Marcus Bochi da Silva Volk

2009-01-01

Full Text Available The objective of this study was to evaluate the effectiveness of artificial cooling associated with the use of diatomaceous earth to control insects in grains of wheat stored in concrete silos. We used two concrete silos, with a static capacity of 2.500 t (Silo A and the other with static capacity of 5.000 t (Silo B. The surface of the grain silos were treated with diatom earth with a commercial assay (1.0 kg / t of product. For the cooling of the grains, cold air was blown through the aeration system silos until the grains reach a temperature of 17 ° C between the layers. After cooling, it is the retention period of five months. The monitoring of insects in the Silo A was accomplished by collecting infested grain and / or insects with probes. In Silo B, the monitoring was done through the capture of insects with traps of the type calador. In The Silo, were not detected representative quantities of insects in grain up to 120 days, when the collections were made with probes in the layer below the grain treated with diatomaceous earth. In Silo B, where the collection of insects was performed with traps of the type calador, increased population of insects of the species O. surinamensis and R. dominica with the extension of storage. This increase in the number of insects was greater after 60 days of the early experiments. This is happening due to the presence of insects in grain mass before cooling. The use of cooling associated with the inert powder has an effective control of insects in grain mass.

National security. Nuclear silo counterforce: calculating the Soviet--U.S. balance

International Nuclear Information System (INIS)

Anon.

1975-01-01

In recent months the nuclear counterforce work of Kosta Tsipis of the Stockholm International Peace Research Institute and the Massachusetts Institute of Technology has gained wide circulation. His arguments are grounded on comparing, for the Soviet Union and the U. S., the lethality (or K factor), rather than numbers of missiles or throw weight. The latter parameters, he claims, are irrelevant to a counterforce capability against ICBM silos, whereas K, which is a function of yield and accuracy, is a valid measure of potential counterforce performance. Using K factors, he reaches a number of conclusions indicating that the U. S. has and will continue to have counterforce superiority over the U.S.S.R. We have analyzed the counterforce situation also using K factors, but taking into account several parameters and arguments not included by Dr. Tsipis. Although some of the conclusions of our analysis agree with his, there are significant differences. In particular, we find that by 1985 the Soviet Union could equal the U. S. in counterforce lethality and could have a first-strike countersilo capability. (auth)

Estimation of above ground biomass by using multispectral data for Evergreen Forest in Phu Hin Rong Kla National Park, Thailand

International Nuclear Information System (INIS)

Suwanprasit, C.

2010-01-01

Tropical forest is the most important and largest source for stocking CO 2 from the atmosphere which might be one of the main sources of carbon emission, global warming and climate change in recent decades. There are two main objectives of this study. The first one is to establish a relationship between above ground biomass and vegetation indices and the other is to evaluate above ground biomass and carbon sequestration for evergreen forest areas in Phu Hin Rong Kla National park, Thailand. Random sampling design based was applied for calculating the above ground biomass at stand level in the selected area by using Brown and Tsutsumi allometric equations. Landsat 7 ETM+ data in February 2009 was used. Support Vector Machine (SVM) was applied for identifying evergreen forest area. Forty-three of vegetation indices and image transformations were used for finding the best correlation with forest stand biomass. Regression analysis was used to investigate the relationship between the biomass volume at stand level and digital data from the satellite image. TM51 which derived from Tsutsumi allometric equation was the highest correlation with stand biomass. Normalized Difference Vegetation Index (NDVI) was not the best correlation in this study. The best biomass estimation model was from TM51 and ND71 (R2 =0.658). The totals of above ground biomass and carbon sequestration were 112,062,010 ton and 56,031,005 ton respectively. The application of this study would be quite useful for understanding the terrestrial carbon dynamics and global climate change. (author)

Compatible above-ground biomass equations and carbon stock estimation for small diameter Turkish pine (Pinus brutia Ten.).

Science.gov (United States)

Sakici, Oytun Emre; Kucuk, Omer; Ashraf, Muhammad Irfan

2018-04-15

Small trees and saplings are important for forest management, carbon stock estimation, ecological modeling, and fire management planning. Turkish pine (Pinus brutia Ten.) is a common coniferous species and comprises 25.1% of total forest area of Turkey. Turkish pine is also important due to its flammable fuel characteristics. In this study, compatible above-ground biomass equations were developed to predict needle, branch, stem wood, and above-ground total biomass, and carbon stock assessment was also described for Turkish pine which is smaller than 8 cm diameter at breast height or shorter than breast height. Compatible biomass equations are useful for biomass prediction of small diameter individuals of Turkish pine. These equations will also be helpful in determining fire behavior characteristics and calculating their carbon stock. Overall, present study will be useful for developing ecological models, forest management plans, silvicultural plans, and fire management plans.

Mapping the spatial pattern of temperate forest above ground biomass by integrating airborne lidar with Radarsat-2 imagery via geostatistical models

Science.gov (United States)

Li, Wang; Niu, Zheng; Gao, Shuai; Wang, Cheng

2014-11-01

Light Detection and Ranging (LiDAR) and Synthetic Aperture Radar (SAR) are two competitive active remote sensing techniques in forest above ground biomass estimation, which is important for forest management and global climate change study. This study aims to further explore their capabilities in temperate forest above ground biomass (AGB) estimation by emphasizing the spatial auto-correlation of variables obtained from these two remote sensing tools, which is a usually overlooked aspect in remote sensing applications to vegetation studies. Remote sensing variables including airborne LiDAR metrics, backscattering coefficient for different SAR polarizations and their ratio variables for Radarsat-2 imagery were calculated. First, simple linear regression models (SLR) was established between the field-estimated above ground biomass and the remote sensing variables. Pearson's correlation coefficient (R2) was used to find which LiDAR metric showed the most significant correlation with the regression residuals and could be selected as co-variable in regression co-kriging (RCoKrig). Second, regression co-kriging was conducted by choosing the regression residuals as dependent variable and the LiDAR metric (Hmean) with highest R2 as co-variable. Third, above ground biomass over the study area was estimated using SLR model and RCoKrig model, respectively. The results for these two models were validated using the same ground points. Results showed that both of these two methods achieved satisfactory prediction accuracy, while regression co-kriging showed the lower estimation error. It is proved that regression co-kriging model is feasible and effective in mapping the spatial pattern of AGB in the temperate forest using Radarsat-2 data calibrated by airborne LiDAR metrics.

New perspectives on the "silo effect": initial comparisons of network structures across public health collaboratives.

Science.gov (United States)

Bevc, Christine A; Retrum, Jessica H; Varda, Danielle M

2015-04-01

We explored to what extent "silos" (preferential partnering) persist in interorganizational boundaries despite advances in working across boundaries. We focused on organizational homophily and resulting silo effects within networks that might both facilitate and impede success in public health collaboratives (PHCs). We analyzed data from 162 PHCs with a series of exponential random graph models to determine the influence of uniform and differential homophily among organizations and to identify the propensity for partnerships with similar organizations. The results demonstrated a low presence (8%) of uniform homophily among networks, whereas a greater number (30%) of PHCs contained varying levels of differential homophily by 1 or more types of organization. We noted that the higher frequency among law enforcement, nonprofits, and public health organizations demonstrated a partner preference with similar organizations. Although we identified only a modest occurrence of partner preference in PHCs, overall success in efforts to work across boundaries might be problematic when public health members (often leaders of PHCs) exhibit the tendency to form silos.

Votive deposit or destroyed necropolis?: the protohistoric silo of El Pontarró (La Secuita, Tarragona

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Maria Carme Belarte

2017-12-01

Full Text Available This work analyzes the materials recovered from the silo of ‘El Pontarró’, located in La Secuita (Tarragona, filled with debris dated to the end of the 5th century BC or the beginnings of the 4th century BC. Among them, a number of bronze ornaments and about 6,000 glass beads stand out, together with pottery, spindle whorls, querns, as well as faunal, malacological (mainly Cypraea and archaeobotanical remains. Most elements are rare and related to funerary or ritual practices. This supports the hypothesis that the filling of the silo could correspond to a ritual action, perhaps after the destruction of a necropolis. The accidental discovery of the silo as well as the altered field conditions that for the moment make further archaeological intervention impossible, prevent gaining more information about the context of the deposit. Nevertheless, its contents include the biggest assemblage of glass beads from the Protohistory of the the Iberian Peninsula and are thus.

Continuous monitoring of a mountain snowpack in the Austrian Alps by above-ground neutron sensing

Science.gov (United States)

Schattan, Paul; Baroni, Gabriele; Oswald, Sascha E.; Schöber, Johannes; Fey, Christine; Francke, Till; Huttenlau, Matthias; Achleitner, Stefan

2017-04-01

In alpine catchments the knowledge of the spatially and temporally heterogeneous dynamics of snow accumulation and depletion is crucial for modelling and managing water resources. While snow covered area can be retrieved operationally from remote sensing data, continuous measurements of other snow state variables like snow depth (SD) or snow water equivalent (SWE) remain challenging. Existing methods of retrieving both variables in alpine terrain face severe issues like a lack of spatial representativeness, labour-intensity or discontinuity in time. Recently, promising new measurement techniques combining a larger support with low maintenance cost like above-ground gamma-ray scintillators, GPS interferometric reflectometry or above-ground cosmic-ray neutron sensors (CRNS) have been suggested. While CRNS has proven its potential for monitoring soil moisture in a wide range of environments and applications, the empirical knowledge of using CRNS for snowpack monitoring is still very limited and restricted to shallow snowpacks with rather uniform evolution. The characteristics of an above-ground cosmic-ray neutron sensor (CRNS) were therefore evaluated for monitoring a mountain snowpack in the Austrian Alps (Kaunertal, Tyrol) during three winter seasons. The measurement campaign included a number of measurements during the period from 03/2014 to 06/2016: (i) neutron count measurements by CRNS, (ii) continuous point-scale SD and SWE measurements from an automatic weather station and (iii) 17 Terrestrial Laser Scanning (TLS) with simultaneous SD and SWE surveys. The highest accumulation in terms of SWE was found in 04/2014 with 600 mm. Neutron counts were compared to all available snow data. While previous studies suggested a signal saturation at around 100 mm of SWE, no complete signal saturation was found. A strong non-linear relation was found for both SD and SWE with best fits for spatially distributed TLS based snow data. Initially slightly different shapes were

Evaluation of ambient dose equivalent rates influenced by vertical and horizontal distribution of radioactive cesium in soil in Fukushima Prefecture.

Science.gov (United States)

Malins, Alex; Kurikami, Hiroshi; Nakama, Shigeo; Saito, Tatsuo; Okumura, Masahiko; Machida, Masahiko; Kitamura, Akihiro

2016-01-01

The air dose rate in an environment contaminated with (134)Cs and (137)Cs depends on the amount, depth profile and horizontal distribution of these contaminants within the ground. This paper introduces and verifies a tool that models these variables and calculates ambient dose equivalent rates at 1 m above the ground. Good correlation is found between predicted dose rates and dose rates measured with survey meters in Fukushima Prefecture in areas contaminated with radiocesium from the Fukushima Dai-ichi Nuclear Power Plant accident. This finding is insensitive to the choice for modeling the activity depth distribution in the ground using activity measurements of collected soil layers, or by using exponential and hyperbolic secant fits to the measurement data. Better predictions are obtained by modeling the horizontal distribution of radioactive cesium across an area if multiple soil samples are available, as opposed to assuming a spatially homogeneous contamination distribution. Reductions seen in air dose rates above flat, undisturbed fields in Fukushima Prefecture are consistent with decrement by radioactive decay and downward migration of cesium into soil. Analysis of remediation strategies for farmland soils confirmed that topsoil removal and interchanging a topsoil layer with a subsoil layer result in similar reductions in the air dose rate. These two strategies are more effective than reverse tillage to invert and mix the topsoil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests

Science.gov (United States)

McIntosh, Anne C. S.; Macdonald, S. Ellen; Quideau, Sylvie A.

2016-01-01

Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta Forests.

Directory of Open Access Journals (Sweden)

Anne C S McIntosh

Full Text Available Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs and multiple carbon-source substrate-induced respiration (MSIR of the forest floor microbial community environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis showed that two above-ground (mean tree diameter, litter cover and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs properties were associated with variation in understory plant community composition. These results provide

Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests.

Science.gov (United States)

McIntosh, Anne C S; Macdonald, S Ellen; Quideau, Sylvie A

2016-01-01

Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

Construcción de silos con encofrados deslizantes - Santa Cruz de Tenerife – España

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Barrios Martínez, M.

1976-10-01

Full Text Available These cereal and oil-cake silos are made up of 10 exterior cylindrical cells, with an inner diameter of 6 m and a height of 31.88 m. The cells are joined together by means of walls whereby four additional octagonal cells are created. Out of these, three are subdivided into four cells and the fourth forms the central silo. Below this unit there is a corridor for the emptying of the silos. The work has been carried out with a travelling form with the following characteristics: mixed with regard to shape and materials; stiff, since the top platforms are connected; and it has a constant cross-section as the dimensions of the silos remain the same throughout the whole height. The form was lifted by means of elevation devices, controlled by a centralized hydraulic mechanism. In view of the characteristics of the travelling form, the concrete used ¡n the work had to fulfill several very special conditions, notably different from these applying to the concrete that is normally used for fixed forms. For this reason, it was submitted to a great number of studies and tests until the requirements had been met. The construction was finished in record time: in the first place, because a detailed programme had been worked out in advance, consisting of a diagram of bars and preference network and secondly, because continuous concreting was applied with day and night shifts, whebery the foreseen two and a half months for finishing the silos were reduced to 12 days.Estos silos, destinados a almacenamiento de cereales y borujo, están formados por 10 celdas exteriores cilíndricas, de 6 m de diámetro interior y 31,88 m de altura, que se unen entre sí por medio de muros, dando lugar a cuatro celdas adicionales de forma octogonal. De éstas, tres están subdivididas en cuatro interceldas, quedando la cuarta como silo central. Debajo del conjunto se ha dispuesto una galería para el vaciado de los silos. La obra se ha realizado con un encofrado deslizante

Squat Ground Reaction Force on a Horizontal Squat Device, Free Weights, and Smith Machine

Science.gov (United States)

Scott-Pandorf, Melissa M.; Newby, Nathaniel J.; Caldwell, Erin; DeWitt, John K.; Peters, Brian T.

2010-01-01

Bed rest is an analog to spaceflight and advancement of exercise countermeasures is dependent on the development of exercise equipment that closely mimic actual upright exercise. The Horizontal Squat Device (HSD) was developed to allow a supine exerciser to perform squats that mimic upright squat exercise. PURPOSE: To compare vertical ground reaction force (GRFv) on the HSD with Free Weight (FW) or Smith Machine (SM) during squat exercise. METHODS: Subjects (3F, 3M) performed sets of squat exercise with increasing loads up to 1-repetition (rep) maximum. GRF data were collected and compared with previous GRF data for squat exercise performed with FW & SM. Loads on the HSD were adjusted to magnitudes comparable with FW & SM by subtracting the subject s body weight (BW). Peak GRFv for 45-, 55-, 64-, & 73-kg loads above BW were calculated. Percent (%) difference between HSD and the two upright conditions were computed. Effect size was calculated for the 45-kg load. RESULTS: Most subjects were unable to lift >45 kg on the HSD; however, 1 subject completed all loads. Anecdotal evidence suggested that most subjects shoulders or back failed before their legs. The mean % difference are shown. In the 45-kg condition, effect sizes were 0.37 & 0.83 (p>0.05) for HSD vs. FW and HSD vs. SM, respectively, indicating no differences between exercise modes. CONCLUSION: When BW was added to the target load, results indicated that vertical forces were similar to those in FW and SM exercise. The exercise prescription for the HSD should include a total external resistance equivalent to goal load plus subject BW. The HSD may be used as an analog to upright exercise in bed rest studies, but because most subjects were unable to lift >45 kg, it may be necessary to prescribe higher reps and lower loads to better target the leg musculature

The impact of forest structure and spatial scale on the relationship between ground plot above ground biomass and GEDI lidar waveforms

Science.gov (United States)

Armston, J.; Marselis, S.; Hancock, S.; Duncanson, L.; Tang, H.; Kellner, J. R.; Calders, K.; Disney, M.; Dubayah, R.

2017-12-01

The NASA Global Ecosystem Dynamics Investigation (GEDI) will place a multi-beam waveform lidar instrument on the International Space Station (ISS) to provide measurements of forest vertical structure globally. These measurements of structure will underpin empirical modelling of above ground biomass density (AGBD) at the scale of individual GEDI lidar footprints (25m diameter). The GEDI pre-launch calibration strategy for footprint level models relies on linking AGBD estimates from ground plots with GEDI lidar waveforms simulated from coincident discrete return airborne laser scanning data. Currently available ground plot data have variable and often large uncertainty at the spatial resolution of GEDI footprints due to poor colocation, allometric model error, sample size and plot edge effects. The relative importance of these sources of uncertainty partly depends on the quality of ground measurements and region. It is usually difficult to know the magnitude of these uncertainties a priori so a common approach to mitigate their influence on model training is to aggregate ground plot and waveform lidar data to a coarser spatial scale (0.25-1ha). Here we examine the impacts of these principal sources of uncertainty using a 3D simulation approach. Sets of realistic tree models generated from terrestrial laser scanning (TLS) data or parametric modelling matched to tree inventory data were assembled from four contrasting forest plots across tropical rainforest, deciduous temperate forest, and sclerophyll eucalypt woodland sites. These tree models were used to simulate geometrically explicit 3D scenes with variable tree density, size class and spatial distribution. GEDI lidar waveforms are simulated over ground plots within these scenes using monte carlo ray tracing, allowing the impact of varying ground plot and waveform colocation error, forest structure and edge effects on the relationship between ground plot AGBD and GEDI lidar waveforms to be directly assessed. We

Long-term changes in above ground biomass after disturbance in a neotropical dry forest, Hellshire Hills, Jamaica

DEFF Research Database (Denmark)

Niño, Milena; McLaren, Kurt P.; Meilby, Henrik

2014-01-01

We used data from experimental plots (control, partially cut and clear-cut) established in 1998, in a tropical dry forest (TDF) in Jamaica, to assess changes in above ground biomass (AGB) 10 years after disturbance. The treatments reduced AGB significantly in 1999 (partially cut: 37.6 %, clear-cu...

SIMULATION OF A MATHEMATICAL MODEL FOR THE TEMPERATURE PROFILE IN A SILO BAG FOR BEAN

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M. R. Hauth

2015-02-01

Full Text Available The problems encountered with storage of agricultural products has warranted studies related to finding alternative methods of grain storage, thereby avoiding unnecessary losses. Stored grain deteriorates quickly at high temperatures. The moisture content of the grain influences the respiratory process; therefore, when at the recommended humidity of between 11 and 13%, this rate remains low, it prolongs maintenance of the product quality. The silo bag being airtight enables the grain mass to consume the entire internal O2 purse within it, and in that low or absent oxygen environment the grain mass saturates the CO2 atmosphere, inhibiting the multiplication of insects and fungi, thus providing a controlled environment. This study aims at simulating, using Computational Fluid Dynamics (CFD, the time it would take for the entire grain mass contained in a silo bag to reach thermal equilibrium with the environment and analyzes the feasibility of the technique employed here. The simulations were performed based on the data of the average air temperature in the region at each harvest time and the average storage temperature of the bean mass (60°C. The results obtained from the simulations reveal that after one month of silo storage the entire bag remains in thermal stabilization, and four months later when it hits the entire mass, all the beans are in thermal equilibrium. Therefore, maintaining stable temperature and humidity within the recommended silo bag preserves the grain quality well.

Impact of deforestation and climate on the Amazon Basin's above-ground biomass during 1993-2012.

Science.gov (United States)

Exbrayat, Jean-François; Liu, Yi Y; Williams, Mathew

2017-11-15

Since the 1960s, large-scale deforestation in the Amazon Basin has contributed to rising global CO 2 concentrations and to climate change. Recent advances in satellite observations enable estimates of gross losses of above-ground biomass (AGB) stocks due to deforestation. However, because of simultaneous regrowth, the net contribution of deforestation emissions to rising atmospheric CO 2 concentrations is poorly quantified. Climate change may also reduce the potential for forest regeneration in previously disturbed regions. Here, we address these points of uncertainty with a machine-learning approach that combines satellite observations of AGB with climate data across the Amazon Basin to reconstruct annual maps of potential AGB during 1993-2012, the above-ground C storage potential of the undisturbed landscape. We derive a 2.2 Pg C loss of AGB over the study period, and, for the regions where these losses occur, we estimate a 0.7 Pg C reduction in potential AGB. Thus, climate change has led to a decline of ~1/3 in the capacity of these disturbed forests to recover and recapture the C lost in disturbances during 1993-2012. Our approach further shows that annual variations in land use change mask the natural relationship between the El Niño/Southern Oscillation and AGB stocks in disturbed regions.

An experimental study on the resistance and movement of short pile installed in sands under horizontal pullout load

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Oh Kyun Kwon

2014-03-01

Full Text Available In this study, the model tests were conducted on the short piles installed in sands under a horizontal pullout load to investigate their behavior characteristics. From the horizontal loading tests where dimensions of the pile diameter and length, and loading point were varied, the horizontal pullout resistance and the rotational and translational movement pattern of the pile were investigated. As a result, the horizontal pullout resistance of the pile embedded in sands was dependent on the pile length, diameter, loading point, etc. The ultimate horizontal pullout load tended to increase as the loading point (h/L moved to the bottom from the top of the pile, regardless of the ratio between the pile length and diameter (L/D, reached the maximum value at the point of h/L = 0.75, and decreased afterwards. When the horizontal pullout load acted on the upper part above the middle of the pile, the pile rotated clockwise and moved to the pullout direction, and the pivot point of the pile was located at 150–360mm depth below the ground surface. On the other hand, when the horizontal pullout load acted on the lower part of the pile, the pile rotated counterclockwise and travelled horizontally, and the rotational angle was very small.

Extinguishing smouldering fires in silos. BRANDFORSK project 745-961

Energy Technology Data Exchange (ETDEWEB)

Tuomisaari, M.; Baroudi, D.; Latva, R. [VTT Building Technology, Espoo (Finland). Building Physics, Building Services and Fire Technology

1998-11-01

Combustible, porous materials may self-ignite during their storage time in silos as a result of internal heating. The self-ignition process may be slow, and it results in smouldering fires that are extremely difficult to extinguish. Suitable means to fight the smouldering fire were studied both theoretically and experimentally. General heat and mass transfer equations for porous media subject to fires and suppression were written. The equations together with dimensional analysis revealed critical parameters, like the grain size and moisture content, affecting the combustion and suppression process, but they also revealed the complexity of the problem. Experimental results of over 50 tests with varying combustibles and suppression agents were used as the basis for proposed qualitative guidelines on how to fight a smouldering silo fire. Among the potential gaseous agents, CO{sub 2} was found to be the most efficient one. Low expansion foam was also found to be a potential candidate, but its applicability requires further confirmation. Quantifying the guidelines requires a whole new study on the detection of a smouldering fire. The same detection system should be capable of monitoring the suppression process and - most importantly - verifying the extinguishment. (orig.) 46 refs.

Long-Term Performance of Silo Concrete in Low- and Intermediate-Level Waste (LILW) Disposal Facility

International Nuclear Information System (INIS)

Jung, Hae Ryong; Kwon, Ki Jung; Lee, Seung Hyun; Lee, Sung Bok; Jeong, Yi Yeong; Yoon, Eui Sik; Kim, Do Gyeum

2012-01-01

Concrete has been considered one of the engineered barriers in the geological disposal facility for low- and intermediate-level wastes (LILW). The concrete plays major role as structural support, groundwater infiltration barrier, and transport barrier of radionuclides dissolved from radioactive wastes. It also works as a chemical barrier due to its high pH condition. However, the performance of the concrete structure decrease over a period of time because of several physical and chemical processes. After a long period of time in the future, the concrete would lose its effectiveness as a barrier against groundwater inflow and the release of radionuclides. An subsurface environment below the frost depth should be favorable for concrete longevity as temperature and moisture variation should be minimal, significantly reducing the potential of cracking due to drying shrinkage and thermal expansion and contraction. Therefore, the concrete structures of LILW disposal facilities below groundwater table are expected to have relatively longer service life than those of near-surface or surface concrete structures. LILW in Korea is considered to be disposed of in the Wolsong LILW Disposal Center which is under construction in geological formation. 100,000 waste packages are expected to be disposed in the 6 concrete silos below EL -80m in the Wolsong LILW Disposal Center as first stage. The concrete silo has been considered the main engineered barrier which plays a role to inhibit water inflow and the release of radionuclides to the environments. Although a number of processes are responsible for the degradation of the silo concrete, it is concluded that a reinforcing steel corrosion cause the failure of the silo concrete. Therefore, a concrete silo failure time is calculated based on a corrosion initiation time which takes for chloride ions to penetrate through the concrete cover, and a corrosion propagation time. This paper aims to analyze the concrete failure time in the

Long-Term Performance of Silo Concrete in Low- and Intermediate-Level Waste (LILW) Disposal Facility

Energy Technology Data Exchange (ETDEWEB)

Jung, Hae Ryong; Kwon, Ki Jung; Lee, Seung Hyun; Lee, Sung Bok; Jeong, Yi Yeong [Korea Radioactive-waste Management Corporation, Daejeon (Korea, Republic of); Yoon, Eui Sik [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kim, Do Gyeum [Korea Institute of Construction Technology, Goyang (Korea, Republic of)

2012-05-15

Concrete has been considered one of the engineered barriers in the geological disposal facility for low- and intermediate-level wastes (LILW). The concrete plays major role as structural support, groundwater infiltration barrier, and transport barrier of radionuclides dissolved from radioactive wastes. It also works as a chemical barrier due to its high pH condition. However, the performance of the concrete structure decrease over a period of time because of several physical and chemical processes. After a long period of time in the future, the concrete would lose its effectiveness as a barrier against groundwater inflow and the release of radionuclides. An subsurface environment below the frost depth should be favorable for concrete longevity as temperature and moisture variation should be minimal, significantly reducing the potential of cracking due to drying shrinkage and thermal expansion and contraction. Therefore, the concrete structures of LILW disposal facilities below groundwater table are expected to have relatively longer service life than those of near-surface or surface concrete structures. LILW in Korea is considered to be disposed of in the Wolsong LILW Disposal Center which is under construction in geological formation. 100,000 waste packages are expected to be disposed in the 6 concrete silos below EL -80m in the Wolsong LILW Disposal Center as first stage. The concrete silo has been considered the main engineered barrier which plays a role to inhibit water inflow and the release of radionuclides to the environments. Although a number of processes are responsible for the degradation of the silo concrete, it is concluded that a reinforcing steel corrosion cause the failure of the silo concrete. Therefore, a concrete silo failure time is calculated based on a corrosion initiation time which takes for chloride ions to penetrate through the concrete cover, and a corrosion propagation time. This paper aims to analyze the concrete failure time in the

Performance evaluation of termite-mound clay, concrete and steel silos for the storage of maize grains in the humid tropics

Science.gov (United States)

Inadequate storage facilities have contributed to severe maize postharvest losses in many developing countries. This study determined the potential of termite mound clay (TMC), a readily-available material in Nigeria, as a construction material for storage silos. The performance of the TMC silo was ...

Contribution of above- and below-ground plant traits to the structure and function of grassland soil microbial communities.

Science.gov (United States)

Legay, N; Baxendale, C; Grigulis, K; Krainer, U; Kastl, E; Schloter, M; Bardgett, R D; Arnoldi, C; Bahn, M; Dumont, M; Poly, F; Pommier, T; Clément, J C; Lavorel, S

2014-10-01

Abiotic properties of soil are known to be major drivers of the microbial community within it. Our understanding of how soil microbial properties are related to the functional structure and diversity of plant communities, however, is limited and largely restricted to above-ground plant traits, with the role of below-ground traits being poorly understood. This study investigated the relative contributions of soil abiotic properties and plant traits, both above-ground and below-ground, to variations in microbial processes involved in grassland nitrogen turnover. In mountain grasslands distributed across three European sites, a correlative approach was used to examine the role of a large range of plant functional traits and soil abiotic factors on microbial variables, including gene abundance of nitrifiers and denitrifiers and their potential activities. Direct effects of soil abiotic parameters were found to have the most significant influence on the microbial groups investigated. Indirect pathways via plant functional traits contributed substantially to explaining the relative abundance of fungi and bacteria and gene abundances of the investigated microbial communities, while they explained little of the variance in microbial activities. Gene abundances of nitrifiers and denitrifiers were most strongly related to below-ground plant traits, suggesting that they were the most relevant traits for explaining variation in community structure and abundances of soil microbes involved in nitrification and denitrification. The results suggest that consideration of plant traits, and especially below-ground traits, increases our ability to describe variation in the abundances and the functional characteristics of microbial communities in grassland soils. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Water activities in Forsmark (Part II). The final disposal facility for spent fuel: water activities above ground

International Nuclear Information System (INIS)

Werner, Kent; Hamren, Ulrika; Collinder, Per; Ridderstolpe, Peter

2010-09-01

The construction of the repository for spent nuclear fuel in Forsmark is associated with a number of measures above ground that constitute water operations according to Chapter 11 in the Swedish Environmental Code. This report, which is an appendix to the Environmental Impact Assessment, describes these water operations, their effects and consequences, and planned measures

Strength and durability tests of pipeline supports for the areas of above-ground routing under the influence of operational loads

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Surikov Vitaliy Ivanovich

2014-03-01

Full Text Available The present article deals with integrated research works and tests of pipeline supports for the areas of above-ground routing of the pipeline system “Zapolyarye - Pur-pe” which is laid in the eternally frozen grounds. In order to ensure the above-ground routing method for the oil pipeline “Zapolyarye - Pur-pe” and in view of the lack of construction experience in case of above-ground routing of oil pipelines, the leading research institute of JSC “Transneft” - LLC “NII TNN” over the period of August, 2011 - September, 2012 performed a research and development work on the subject “Development and production of pipeline supports and pile foundation test specimens for the areas of above-ground routing of the pipeline system “Zapolyarye - Pur-pe”. In the course of the works, the test specimens of fixed support, linear-sliding and free-sliding pipeline supports DN1000 and DN800 were produced and examined. For ensuring the stable structural reliability of the supports constructions and operational integrity of the pipelines the complex research works and tests were performed: 1. Cyclic tests of structural elements of the fixed support on the test bed of JSC “Diascan” by means of internal pressure and bending moment with the application of specially prepared equipment for defining the pipeline supports strength and durability. 2. Tests of the fixed support under the influence of limit operating loads and by means of internal pressure for confirming the support’s integrity. On the test bed there were simulated all the maximum loads on the support (vertical, longitudinal, side loadings, bending moment including subsidence of the neighboring sliding support and, simultaneously, internal pressure of the carried medium. 3. Cyclic tests of endurance and stability of the displacements of sliding supports under the influence of limit operating loads for confirming their operation capacity. Relocation of the pipeline on the sliding

How to Move Away from the Silos of Business Management Education?

Science.gov (United States)

Nisula, Karoliina; Pekkola, Samuli

2018-01-01

Business management education is criticized for being too theoretical and fractional. Despite the numerous efforts to build integrated and experiential business curricula, learning is still organized in disciplinary silos. The curriculum integration efforts are carried out in separate sections of the curriculum rather than the core. There are…

Magnox Swarf Storage Silo Liquor Effluent Management -Sellafield Site, Cumbria, UK - Legacy radioactive waste storage - 59271

International Nuclear Information System (INIS)

Le Clere, Stephen

2012-01-01

The Sellafield Magnox Swarf Storage Silo (MSSS) was constructed to provide an underwater storage facility for irradiated magnox cladding metal Swarf, as well as miscellaneous beta-gamma waste from several sources. Liquid effluent arisings from hazard reduction activities at this facility represent the toughest effluent treatment challenge within the company's Legacy Ponds and Silos portfolio. The key requirement for hazard reduction has generated many substantial challenges as the facility is readied for decommissioning. This has demanded the production of carefully thought out strategies for managing, and overcoming, the key difficulties to be encountered as hazard reduction progresses. The complexity associated with preparing for waste retrievals from the Magnox Swarf Storage Silo, has also generated the demand for a mix of creativity and perseverance to meet the challenges and make progress. Challenging the status quo and willingness to accept change is not easy and the road to overall hazard reduction for the high hazard MSSS facility will demand the skills and investment of individuals, teams, and entire facility work-forces. The first steps on this road have been taken with the successful introduction of liquor management operations, however much more is yet to be achieved. Clear communication, investing in stakeholder management, perseverance in the face of difficulty and a structured yet flexible programme delivery approach, will ensure the continued success of tackling the complex challenges of treating liquid effluent from a legacy fuel storage silo at the Sellafield Site. (authors)

Mapping Above- and Below-Ground Carbon Pools in Boreal Forests: The Case for Airborne Lidar.

Science.gov (United States)

Kristensen, Terje; Næsset, Erik; Ohlson, Mikael; Bolstad, Paul V; Kolka, Randall

2015-01-01

A large and growing body of evidence has demonstrated that airborne scanning light detection and ranging (lidar) systems can be an effective tool in measuring and monitoring above-ground forest tree biomass. However, the potential of lidar as an all-round tool for assisting in assessment of carbon (C) stocks in soil and non-tree vegetation components of the forest ecosystem has been given much less attention. Here we combine the use airborne small footprint scanning lidar with fine-scale spatial C data relating to vegetation and the soil surface to describe and contrast the size and spatial distribution of C pools within and among multilayered Norway spruce (Picea abies) stands. Predictor variables from lidar derived metrics delivered precise models of above- and below-ground tree C, which comprised the largest C pool in our study stands. We also found evidence that lidar canopy data correlated well with the variation in field layer C stock, consisting mainly of ericaceous dwarf shrubs and herbaceous plants. However, lidar metrics derived directly from understory echoes did not yield significant models. Furthermore, our results indicate that the variation in both the mosses and soil organic layer C stock plots appears less influenced by differences in stand structure properties than topographical gradients. By using topographical models from lidar ground returns we were able to establish a strong correlation between lidar data and the organic layer C stock at a stand level. Increasing the topographical resolution from plot averages (~2000 m2) towards individual grid cells (1 m2) did not yield consistent models. Our study demonstrates a connection between the size and distribution of different forest C pools and models derived from airborne lidar data, providing a foundation for future research concerning the use of lidar for assessing and monitoring boreal forest C.

La vida de Santo Domingo de Silos: onirocrítica y semántica

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González, Javier Roberto

2007-12-01

Full Text Available We study the prophetic vision of Santo Domingo de Silos in Gonzalo de Berceo’s Vida de Santo Domingo de Silos, with the aim of: a analysing the text according to categories of prophecy, vision and dream in medieval christian culture; b analysing the configuration of oniric images as an allegorical discourse; c given the limits of allegorical semantics, interpreting those symbolic images characterized by prophetical obscuritas in the light of Grimaldus’ Vita Beati Dominici, source of Berceo’s Vida, and also in the light of medieval tradition of Other World visions and general chromatic an arithmetical symbolism, in order to establish semantic innovations and the proper meanning of Berceo’s text.Estudiamos la visión profética de Santo Domingo de Silos en la Vida de Santo Domingo de Silos de Gonzalo de Berceo, con el objeto de: a analizar el texto según las categorías de profecía, visión y sueño vigentes en la cultura cristiana medieval; b analizar la configuración de las imágenes oníricas como discurso alegórico; c dados los límites de la semántica alegórica, interpretar aquellas imágenes simbólicas caracterizadas por la obscuritas profética a la luz de la Vita Beati Dominici de Grimaldo, fuente de la Vida de Berceo, y también a la luz de la tradición medieval de las visiones de trasmundo y del simbolismo general cromático y aritmético, en orden al establecimiento de las innovaciones semánticas y con ellas del recto sentido del texto de Berceo.

Terrestrial laser scanning to quantify above-ground biomass of structurally complex coastal wetland vegetation

Science.gov (United States)

Owers, Christopher J.; Rogers, Kerrylee; Woodroffe, Colin D.

2018-05-01

Above-ground biomass represents a small yet significant contributor to carbon storage in coastal wetlands. Despite this, above-ground biomass is often poorly quantified, particularly in areas where vegetation structure is complex. Traditional methods for providing accurate estimates involve harvesting vegetation to develop mangrove allometric equations and quantify saltmarsh biomass in quadrats. However broad scale application of these methods may not capture structural variability in vegetation resulting in a loss of detail and estimates with considerable uncertainty. Terrestrial laser scanning (TLS) collects high resolution three-dimensional point clouds capable of providing detailed structural morphology of vegetation. This study demonstrates that TLS is a suitable non-destructive method for estimating biomass of structurally complex coastal wetland vegetation. We compare volumetric models, 3-D surface reconstruction and rasterised volume, and point cloud elevation histogram modelling techniques to estimate biomass. Our results show that current volumetric modelling approaches for estimating TLS-derived biomass are comparable to traditional mangrove allometrics and saltmarsh harvesting. However, volumetric modelling approaches oversimplify vegetation structure by under-utilising the large amount of structural information provided by the point cloud. The point cloud elevation histogram model presented in this study, as an alternative to volumetric modelling, utilises all of the information within the point cloud, as opposed to sub-sampling based on specific criteria. This method is simple but highly effective for both mangrove (r2 = 0.95) and saltmarsh (r2 > 0.92) vegetation. Our results provide evidence that application of TLS in coastal wetlands is an effective non-destructive method to accurately quantify biomass for structurally complex vegetation.

Diversity and above-ground biomass patterns of vascular flora induced by flooding in the drawdown area of China's Three Gorges Reservoir.

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Qiang Wang

Full Text Available Hydrological alternation can dramatically influence riparian environments and shape riparian vegetation zonation. However, it was difficult to predict the status in the drawdown area of the Three Gorges Reservoir (TGR, because the hydrological regime created by the dam involves both short periods of summer flooding and long-term winter impoundment for half a year. In order to examine the effects of hydrological alternation on plant diversity and biomass in the drawdown area of TGR, twelve sites distributed along the length of the drawdown area of TGR were chosen to explore the lateral pattern of plant diversity and above-ground biomass at the ends of growing seasons in 2009 and 2010. We recorded 175 vascular plant species in 2009 and 127 in 2010, indicating that a significant loss of vascular flora in the drawdown area of TGR resulted from the new hydrological regimes. Cynodon dactylon and Cyperus rotundus had high tolerance to short periods of summer flooding and long-term winter flooding. Almost half of the remnant species were annuals. Species richness, Shannon-Wiener Index and above-ground biomass of vegetation exhibited an increasing pattern along the elevation gradient, being greater at higher elevations subjected to lower submergence stress. Plant diversity, above-ground biomass and species distribution were significantly influenced by the duration of submergence relative to elevation in both summer and previous winter. Several million tonnes of vegetation would be accumulated on the drawdown area of TGR in every summer and some adverse environmental problems may be introduced when it was submerged in winter. We conclude that vascular flora biodiversity in the drawdown area of TGR has dramatically declined after the impoundment to full capacity. The new hydrological condition, characterized by long-term winter flooding and short periods of summer flooding, determined vegetation biodiversity and above-ground biomass patterns along the

Estimating Stand Volume and Above-Ground Biomass of Urban Forests Using LiDAR

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Vincenzo Giannico

2016-04-01

Full Text Available Assessing forest stand conditions in urban and peri-urban areas is essential to support ecosystem service planning and management, as most of the ecosystem services provided are a consequence of forest stand characteristics. However, collecting data for assessing forest stand conditions is time consuming and labor intensive. A plausible approach for addressing this issue is to establish a relationship between in situ measurements of stand characteristics and data from airborne laser scanning (LiDAR. In this study we assessed forest stand volume and above-ground biomass (AGB in a broadleaved urban forest, using a combination of LiDAR-derived metrics, which takes the form of a forest allometric model. We tested various methods for extracting proxies of basal area (BA and mean stand height (H from the LiDAR point-cloud distribution and evaluated the performance of different models in estimating forest stand volume and AGB. The best predictors for both models were the scale parameters of the Weibull distribution of all returns (except the first (proxy of BA and the 95th percentile of the distribution of all first returns (proxy of H. The R2 were 0.81 (p < 0.01 for the stand volume model and 0.77 (p < 0.01 for the AGB model with a RMSE of 23.66 m3·ha−1 (23.3% and 19.59 Mg·ha−1 (23.9%, respectively. We found that a combination of two LiDAR-derived variables (i.e., proxy of BA and proxy of H, which take the form of a forest allometric model, can be used to estimate stand volume and above-ground biomass in broadleaved urban forest areas. Our results can be compared to other studies conducted using LiDAR in broadleaved forests with similar methods.

Effects of above- and below-ground competition from shrubs on photosynthesis, transpiration and growth in Quercus robur L

Science.gov (United States)

Anna M. Jensen; Magnus Lof; Emile S. Gardiner

2011-01-01

For a tree seedling to successfully establish in dense shrubbery, it must maintain function under heterogeneous resource availability. We evaluated leaf-level acclimation in photosynthetic capacity, seedling-level transpiration, and seedling morphology and growth to gain an understanding of the effects of above- and below-ground competition on Quercus robur seedlings....

Non-linear thermal and structural analysis of a typical spent fuel silo

International Nuclear Information System (INIS)

Alvarez, L.M.; Mancini, G.R.; Spina, O.A.F.; Sala, G.; Paglia, F.

1993-01-01

A numerical method for the non-linear structural analysis of a typical reinforced concrete spent fuel silo under thermal loads is proposed. The numerical time integration was performed by means of a time explicit axisymmetric finite-difference numerical operator. An analysis was made of influences by heat, viscoelasticity and cracking upon the concrete behaviour between concrete pouring stage and the first period of the silo's normal operation. The following parameters were considered for the heat generation and transmission process: Heat generated during the concrete's hardening stage, Solar radiation effects, Natural convection, Spent-fuel heat generation. For the modelling of the reinforced concrete behaviour, use was made of a simplified formulation of: Visco-elastic effects, Thermal cracking, Steel reinforcement. A comparison between some experimental temperature characteristic values obtained from the numerical integration process and empirical data obtained from a 1:1 scaled prototype was also carried out. (author)

Waste-surface mapping of the Fernald K-65 silos using a structured light measurement system

International Nuclear Information System (INIS)

Burks, B.L.; DePiero, F.W.; Dinkins, M.A.; Rowe, J.C.; Selleck, C.B.; Jacoboski, D.L.

1992-10-01

A remotely operated surface-mapping measurement system was developed by the Robotics ampersand Process Systems Division at Oak Ridge National Laboratory for use in the K-65 waste-storage silos at Fernald, Ohio. The mapping system used three infrared line-generating laser diodes as illumination sources and three high-resolution, low-lux, calibrated, black-and-white, charge-coupled-device video cameras as receivers. These components were combined to form structured light source range and direction sensors with six different possible emitter-receiver pairs. A technology demonstration and predeployment tests were performed at Fernald using the empty Silo 4 into which was placed rectangular objects of known dimensions. These objects were scanned by the structured light sources to demonstrate functionality and verify that the system was giving sufficiently accurate range data in three dimensions. The structured light sources were deployed in Silos 1 and 2 to scan the waste surfaces. The resulting data were merged to create three-dimensional maps of those surfaces. A bentonite clay cap was placed over the waste surfaces and surface maps were obtained. The change in surface height before and after bentonite addition was utilized as a measure of clay cap thickness

Case study: evaluation of continuos blending silos in the cement industry, by the aid of tracer techniques; Caso de estudio: Evaluacion de silos continuos de homogenizacion en la industria del cemento, utilizando tecnicas de radiotrazadores

Energy Technology Data Exchange (ETDEWEB)

Sebastian, C; Maghella, G; Mamani, E [Direccion de Aplicaciones. Instituto Peruano de Energia Nuclear, Lima (Peru)

2000-12-01

Besides the actual burning process in cement manufacture, particular importance is attached to raw material preparation and homogenization, not only because of the quality of the kiln fed and therefore of the produced cement, but also because of the economy of the kiln operation, which significantly depends on the uniformity of the chemical composition of the material. As a result, the blending process of the cement raw material, before burning, is a basic stage of cement technology production. In this case, the pneumatic homogenization process is studied in a silo with a great storing and processing capacity. The objective is to evaluate the parameters which influence in the continuos operation. The method allows us to determine the optimal blending parameters, through the observation of the movement and distribution of the different fractions of fine dust raw meal, labelled with La-140 as tracer. Changes in blending according to time are discussed as well as the influence of the silo design on the degree of homogenization. It was showed that the silo blending operation has a strong influence on the production of good-quality cement as well as the implications on energy saving.

Maize Storage in Termite Mound Clay, Concrete, and Steel Silos in the Humid Tropics: Comparison and Effect on Bacterial and Fungal Counts

Science.gov (United States)

This study investigated the functional suitability of using the readily-available termite mound clay (TMC) for grain silo construction in comparison to conventional reinforced concrete (RC) and galvanized steel (GS) silos for maize storage in the humid tropics. The extent to which temperature and r...

Aplicación de la norma EN 14491:2006 a los silos de acero cilíndricos para la protección frente a explosiones de polvo

Directory of Open Access Journals (Sweden)

Tascón, A.

2012-06-01

Full Text Available Dust explosions represent a serious hazard in industries and silo facilities that handle combustible materials. Venting devices are commonly used to try to mitigate the damage caused by any dust explosion. To calculate vent area size, the recommendations given in European standard EN 14491:2006 can be used. However, the protection of silos is not always simple, and frequently the installation of vents becomes technically difficult and costly. The aim of the present work was to analyse the application of standard EN 14491:2006 to cylindrical steel silos, remarking the existing difficulties and limitations and explaining some critical points in order to understand the aforementioned standard. In addition, the cost of protection by venting in silos was studied. Finally, the authors have provided some suggestions to solve the protection of silos, alternative methods to calculate vent areas and expected future trends in this field.

Las explosiones de polvo representan un serio peligro en aquellas industrias y silos en los que se manejan materiales combustibles. Para mitigar los efectos de una posible explosión generalmente se utilizan dispositivos de venteo, que pueden dimensionarse siguiendo la norma europea EN 14491:2006. Sin embargo, frecuentemente surgen complicaciones que hacen que la instalación de venteos sea técnicamente complicada y muy costosa. El objetivo de este trabajo fue analizar la aplicación de la norma EN 14491:2006 a los silos metálicos cilíndricos, remarcando las dificultades y limitaciones existentes y explicando sus aspectos clave para poder aplicarla correctamente. También se ha calculado el coste que puede suponer la protección de silos mediante venteos. Finalmente, se proporcionan algunas sugerencias para afrontar la protección de silos, información sobre métodos alternativos de cálculo de venteos y tendencias de futuro en este campo.

Formulation and evaluation of gas release scenarios for the silo in Swedish Final Repository for Radioactive Waste (SFR)

International Nuclear Information System (INIS)

Carlsson, J.; Moreno, L.

1992-01-01

The Swedish Final Repository for Radioactive Waste (SFR) has been in operation since 1988 and is located in the crystalline rock, 60 m below the Baltic Sea. In the licensing procedure for the SFR the safety assessment has been complemented with a detailed scenario analysis of the performance of the repository. The scenarios include the influence on radionuclide release by gas formation and gas transport processes in the silo. The overall conclusion is that the release of most radionuclides from the silo is only marginally affected by the formation and release of gas, even for scenarios considering unexpected events. The largest effects were found for short-lived radionuclides and radionuclides that have no or low sorption ability. Except for very extreme scenarios for the silo the overall impact from repository on the environment is by far dominated by the release of radionuclides from the rock vaults. 10 refs., 6 figs

An improved system to verify CANDU spent fuel elements in dry storage silos

International Nuclear Information System (INIS)

Almeida, Gevaldo L. de; Soares, Milton G.; Filho, Anizio M.; Martorelli, Daniel S.; Fonseca, Manoel

2000-01-01

An improved system to verify CANDU spent fuel elements stored in dry storage silos was developed. It is constituted by a mechanical device which moves a semi-conductor detector along a vertical verification pipe incorporated to the silo, and a modified portable multi-channel analyzer. The mechanical device contains a winding drum accommodating a cable hanging the detector, in such a way that the drum rotates as the detector goes down due to its own weight. The detector is coupled to the multi-channel analyzer operating in the multi-scaler mode, generating therefore a spectrum of total counts against time. To assure a linear transformation of time into detector position, the mechanical device dictating the detector speed is controlled by the multi-channel analyzer. This control is performed via a clock type escapement device activated by a solenoid. Whenever the multi-channel analyzer shifts to the next channel, the associated pulse is amplified, powering the solenoid causing the drum to rotate a fixed angle. Spectra taken in laboratory, using radioactive sources, have shown a good reproducibility. This qualify the system to be used as an equipment to get a fingerprint of the overall distribution of the fuel elements along the silo axis, and hence, to verify possible diversion of the nuclear material by comparing spectra taken at consecutive safeguards inspections. All the system is battery operated, being thus capable to operate in the field where no power supply is available. (author)

An improved system to verify CANDU spent fuel elements in dry storage silos

Energy Technology Data Exchange (ETDEWEB)

Almeida, Gevaldo L. de; Soares, Milton G.; Filho, Anizio M.; Martorelli, Daniel S.; Fonseca, Manoel [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil)

2000-07-01

An improved system to verify CANDU spent fuel elements stored in dry storage silos was developed. It is constituted by a mechanical device which moves a semi-conductor detector along a vertical verification pipe incorporated to the silo, and a modified portable multi-channel analyzer. The mechanical device contains a winding drum accommodating a cable hanging the detector, in such a way that the drum rotates as the detector goes down due to its own weight. The detector is coupled to the multi-channel analyzer operating in the multi-scaler mode, generating therefore a spectrum of total counts against time. To assure a linear transformation of time into detector position, the mechanical device dictating the detector speed is controlled by the multi-channel analyzer. This control is performed via a clock type escapement device activated by a solenoid. Whenever the multi-channel analyzer shifts to the next channel, the associated pulse is amplified, powering the solenoid causing the drum to rotate a fixed angle. Spectra taken in laboratory, using radioactive sources, have shown a good reproducibility. This qualify the system to be used as an equipment to get a fingerprint of the overall distribution of the fuel elements along the silo axis, and hence, to verify possible diversion of the nuclear material by comparing spectra taken at consecutive safeguards inspections. All the system is battery operated, being thus capable to operate in the field where no power supply is available. (author)

Changes in ground beetle assemblages above and below the treeline of the Dolomites after almost 30 years (1980/2009)

OpenAIRE

Pizzolotto, Roberto; Gobbi, Mauro; Brandmayr, Pietro

2014-01-01

Very little is known about the changes of ground beetle assemblages in the last few decades in the Alps, and different responses to climate change of animal populations living above and below the treeline have not been estimated yet. This study focuses on an altitudinal habitat sequence from subalpine spruce forest to alpine grassland in a low disturbance area of the southeastern Dolomites in Italy, the Paneveggio Regional Park. We compared the ground beetle (Carabidae) populations sampled in...

Effect of nitrogen addition and drought on above-ground biomass of expanding tall grasses Calamagrostis epigejos and Arrhenatherum elatius

Czech Academy of Sciences Publication Activity Database

Fiala, Karel; Tůma, Ivan; Holub, Petr

2011-01-01

Roč. 66, č. 2 (2011), s. 275-281 ISSN 0006-3088 R&D Projects: GA ČR(CZ) GA526/06/0556 Institutional research plan: CEZ:AV0Z60050516 Keywords : nitrogen * drought * above-ground biomass Subject RIV: EF - Botanics Impact factor: 0.557, year: 2011

Competitive responses of seedlings and understory plants in longleaf pine woodlands: separating canopy influences above and below ground

Science.gov (United States)

Stephen D. Pecot; Robert J. Mitchell; Brian J. Palik; Barry Moser; J. Kevin Hiers

2007-01-01

A trenching study was used to investigate above- and below-ground competition in a longleaf pine (Pinus palustris P. Mill.) woodland. Trenched and nontrenched plots were replicated in the woodland matrix, at gap edges, and in gap centers representing a range of overstory stocking. One-half of each plot received a herbicide treatment to remove the...

A method for evaluating horizontal well pumping tests.

Science.gov (United States)

Langseth, David E; Smyth, Andrew H; May, James

2004-01-01

Predicting the future performance of horizontal wells under varying pumping conditions requires estimates of basic aquifer parameters, notably transmissivity and storativity. For vertical wells, there are well-established methods for estimating these parameters, typically based on either the recovery from induced head changes in a well or from the head response in observation wells to pumping in a test well. Comparable aquifer parameter estimation methods for horizontal wells have not been presented in the ground water literature. Formation parameter estimation methods based on measurements of pressure in horizontal wells have been presented in the petroleum industry literature, but these methods have limited applicability for ground water evaluation and are based on pressure measurements in only the horizontal well borehole, rather than in observation wells. This paper presents a simple and versatile method by which pumping test procedures developed for vertical wells can be applied to horizontal well pumping tests. The method presented here uses the principle of superposition to represent the horizontal well as a series of partially penetrating vertical wells. This concept is used to estimate a distance from an observation well at which a vertical well that has the same total pumping rate as the horizontal well will produce the same drawdown as the horizontal well. This equivalent distance may then be associated with an observation well for use in pumping test algorithms and type curves developed for vertical wells. The method is shown to produce good results for confined aquifers and unconfined aquifers in the absence of delayed yield response. For unconfined aquifers, the presence of delayed yield response increases the method error.

Estudo comparativo de diferentes tipos de silos sobre a composição bromatológica e perfil fermentativo da silagem de milho Comparative studies on chemical composition and fermentation characteristics of corn silage

Directory of Open Access Journals (Sweden)

Laércio Melotti

2002-04-01

Full Text Available Três diferentes tipos de silos de laboratório, confeccionados a partir de baldes plásticos, sacos plásticos e manilhas de concreto com revestimento plástico, em dois diferentes graus de compactação (400 ou 600 kg de silagem/m3, foram comparados com o silo comercial tipo trincheira amostrado a 0, 50 e 100 cm da sua superfície. A planta de milho (27,3% de MS e 8,4% de PB foi picada, homogeneizada e utilizada para encher quatro silos por tratamento. Depois de abertos, estes foram amostrados para análise da composição bromatológica e perfil fermentativo. Os teores de MS e PB variaram entre os diferentes extratos do silo comercial e foram intermediários nos silos laboratoriais, indicando maior translocação de água e nutrientes naquele do que nestes. Os silos laboratoriais representaram bem os comerciais, quanto aos componentes da parede celular, amido, carboidratos solúveis e DIVMS. O pH foi menor na silagem obtida no extrato médio, intermediário no profundo e maior na superfície do silo comercial. Silagens obtidas no extrato médio também apresentaram maiores teores de nitrogênio amoniacal e ácido lático, enquanto que as obtidas no extrato profundo apresentaram as concentrações mais elevadas de ácido acético. De forma geral, os silos laboratoriais representaram bem o perfil de fermentação dos silos comerciais (pH, concentração de etanol, acético, propiônico, butírico, lático e N amoniacal, já que a maior variabilidade de resposta foi observada entre os extratos do silo comercialA commercial bunker silo and three types of experimental silos were used for determination of chemical composition and fermentation characteristics of corn silage (27.3% DM and 8.4% CP ensiled in two different densities (400 or 600kg of silage/m3: 1 commercial bunker silo sampled at 0, 50 and 100 cm from the top; 2 plastic silo with bulsen valve; 3 plastic bag; and 4 concrete pipe. Dry matter and CP concentration showed larger variation

Above- and below-ground competition in high and low irradiance: tree seedling responses to a competing liana Byttneria grandifolia

NARCIS (Netherlands)

Chen, J.Y.; Bongers, F.; Cao, K.F.; Cai, Z.Q.

2008-01-01

Abstract: In tropical forests, trees compete not only with other trees, but also with lianas, which may limit tree growth and regeneration. Liana effects may depend on the availability of above- and below-ground resources and differ between tree species. We conducted a shade house experiment to test

Numerical simulations in granular matter: The discharge of a 2D silo

Indian Academy of Sciences (India)

... short and elementary review of numerical simulations in granular assemblies, giving the process of discharge of a 2D silo as an example. The strengths and limitations of different approaches are discussed, together with some comments on the specific issues related to the numerics of discontinuous dissipative collisions.

In situ air stripping using horizontal wells. Innovative technology summary report

International Nuclear Information System (INIS)

1995-04-01

In-situ air stripping employs horizontal wells to inject or sparge air into the ground water and vacuum extract VOC'S from vadose zone soils. The horizontal wells provide better access to the subsurface contamination, and the air sparging eliminates the need for surface ground water treatment systems and treats the subsurface in-situ. A full-scale demonstration was conducted at the Savannah River Plant in an area polluted with trichloroethylene and tetrachloroethylene. Results are described

Ground Boundary Conditions for Thermal Convection Over Horizontal Surfaces at High Rayleigh Numbers

Science.gov (United States)

Hanjalić, K.; Hrebtov, M.

2016-07-01

We present "wall functions" for treating the ground boundary conditions in the computation of thermal convection over horizontal surfaces at high Rayleigh numbers using coarse numerical grids. The functions are formulated for an algebraic-flux model closed by transport equations for the turbulence kinetic energy, its dissipation rate and scalar variance, but could also be applied to other turbulence models. The three-equation algebraic-flux model, solved in a T-RANS mode ("Transient" Reynolds-averaged Navier-Stokes, based on triple decomposition), was shown earlier to reproduce well a number of generic buoyancy-driven flows over heated surfaces, albeit by integrating equations up to the wall. Here we show that by using a set of wall functions satisfactory results are found for the ensemble-averaged properties even on a very coarse computational grid. This is illustrated by the computations of the time evolution of a penetrative mixed layer and Rayleigh-Bénard (open-ended, 4:4:1 domain) convection, using 10 × 10 × 100 and 10 × 10 × 20 grids, compared also with finer grids (e.g. 60 × 60 × 100), as well as with one-dimensional treatment using 1 × 1 × 100 and 1 × 1 × 20 nodes. The approach is deemed functional for simulations of a convective boundary layer and mesoscale atmospheric flows, and pollutant transport over realistic complex hilly terrain with heat islands, urban and natural canopies, for diurnal cycles, or subjected to other time and space variations in ground conditions and stratification.

Horizontal Air-Ground Heat Exchanger Performance and Humidity Simulation by Computational Fluid Dynamic Analysis

Directory of Open Access Journals (Sweden)

Paolo Maria Congedo

2016-11-01

Full Text Available Improving energy efficiency in buildings and promoting renewables are key objectives of European energy policies. Several technological measures are being developed to enhance the energy performance of buildings. Among these, geothermal systems present a huge potential to reduce energy consumption for mechanical ventilation and cooling, but their behavior depending on varying parameters, boundary and climatic conditions is not fully established. In this paper a horizontal air-ground heat exchanger (HAGHE system is studied by the development of a computational fluid dynamics (CFD model. Summer and winter conditions representative of the Mediterranean climate are analyzed to evaluate operation and thermal performance differences. A particular focus is given to humidity variations as this parameter has a major impact on indoor air quality and comfort. Results show the benefits that HAGHE systems can provide in reducing energy consumption in all seasons, in summer when free-cooling can be implemented avoiding post air treatment using heat pumps.

Towards ground-truthing of spaceborne estimates of above-ground biomass and leaf area index in tropical rain forests

Science.gov (United States)

Köhler, P.; Huth, A.

2010-05-01

The canopy height of forests is a key variable which can be obtained using air- or spaceborne remote sensing techniques such as radar interferometry or lidar. If new allometric relationships between canopy height and the biomass stored in the vegetation can be established this would offer the possibility for a global monitoring of the above-ground carbon content on land. In the absence of adequate field data we use simulation results of a tropical rain forest growth model to propose what degree of information might be generated from canopy height and thus to enable ground-truthing of potential future satellite observations. We here analyse the correlation between canopy height in a tropical rain forest with other structural characteristics, such as above-ground biomass (AGB) (and thus carbon content of vegetation) and leaf area index (LAI). The process-based forest growth model FORMIND2.0 was applied to simulate (a) undisturbed forest growth and (b) a wide range of possible disturbance regimes typically for local tree logging conditions for a tropical rain forest site on Borneo (Sabah, Malaysia) in South-East Asia. It is found that for undisturbed forest and a variety of disturbed forests situations AGB can be expressed as a power-law function of canopy height h (AGB=a·hb) with an r2~60% for a spatial resolution of 20 m×20 m (0.04 ha, also called plot size). The regression is becoming significant better for the hectare wide analysis of the disturbed forest sites (r2=91%). There seems to exist no functional dependency between LAI and canopy height, but there is also a linear correlation (r2~60%) between AGB and the area fraction in which the canopy is highly disturbed. A reasonable agreement of our results with observations is obtained from a comparison of the simulations with permanent sampling plot data from the same region and with the large-scale forest inventory in Lambir. We conclude that the spaceborne remote sensing techniques have the potential to

Dealing with Organizational Silos with Communities of Practice and Human Resource Management

Science.gov (United States)

Forsten-Astikainen, Riitta; Hurmelinna-Laukkanen, Pia; Lämsä, Tuija; Heilmann, Pia; Hyrkäs, Elina

2017-01-01

Purpose: Organizational silos that build on the existing organizational structures are often considered to have negative effects in the form of focus on private narrow objectives and organizational fragmentation. To avoid such harmful outcomes, competence management is called for, and in this, the human resources (HR) function takes a key role.…

Hiding levitating objects above a ground plane

DEFF Research Database (Denmark)

Zhang, Jingjing; Luo, Yu; Mortensen, Asger

2010-01-01

An approach to hiding objects levitating above a conducting sheet is suggested in this paper. The proposed device makes use of isotropic negative-refractive-index materials without extreme material parameters, and creates an illusion of a remote conducting sheet. Numerical simulations are perform...

Functional differentiation of trailing and leading forelimbs during locomotion on the ground and on a horizontal branch in the European red squirrel (Sciurus vulgaris, Rodentia).

Science.gov (United States)

Schmidt, André

2011-06-01

Mammalian locomotion is characterized by the frequent use of in-phase gaits in which the footfalls of the left and right fore- or hindlimbs are unevenly spaced in time. Although previous studies have identified a functional differentiation between the first limb (trailing limb) and the second limb (leading limb) to touch the ground during terrestrial locomotion, the influence of a horizontal branch on limb function has never been explored. To determine the functional differences between trailing and leading forelimbs during locomotion on the ground and on a horizontal branch, X-ray motion analysis and force measurements were carried out in two European red squirrels (Sciurus vulgaris, Rodentia). The differences observed between trailing and leading forelimbs were minimal during terrestrial locomotion, where both limbs fulfill two functions and go through a shock-absorbing phase followed by a generating phase. During locomotion on a horizontal branch, European red squirrels reduce speed and all substrate reaction forces transmitted may be due to the reduction of vertical oscillation of the center of mass. Further adjustments during locomotion on a horizontal branch differ significantly between trailing and leading forelimbs and include limb flexion, lead intervals, limb protraction and vertical displacement of the scapular pivot. Consequently, trailing and leading forelimbs perform different functions. Trailing forelimbs function primarily as shock-absorbing elements, whereas leading forelimbs are characterized by a high level of stiffness. This functional differentiation indicates that European red squirrels 'test' the substrate for stability with the trailing forelimb, while the leading forelimb responds to or counteracts swinging or snapping branches. Copyright © 2011 Elsevier GmbH. All rights reserved.

Presión en medios granulares en silos: experimentos para un curso de fluidos

Directory of Open Access Journals (Sweden)

Saulo Hernández López

2015-06-01

Full Text Available Se presentan las experiencias obtenidas en el análisis del comportamiento estático de un medio granular en un silo. Haciendo uso de un dispositivo experimental construido para tal fin, se explora el comportamiento de la presión ejercida sobre el fondo de un silo cuando sobre él descansa una columna de medio granular (maíz sobrecargado y se compara con el de un líquido. Se utiliza el modelo teórico de Janssen para describir el comportamiento de la presión, obteniendo resultados satisfactorios. Este trabajo podrá servir de base en la elaboración de protocolos de prácticas para los laboratorios de los cursos de física clásica que se imparten en los programas de licenciatura en ciencias e ingeniería.

Silo outflow of soft frictionless spheres

Science.gov (United States)

Ashour, Ahmed; Trittel, Torsten; Börzsönyi, Tamás; Stannarius, Ralf

2017-12-01

Outflow of granular materials from silos is a remarkably complex physical phenomenon that has been extensively studied with simple objects like monodisperse hard disks in two dimensions (2D) and hard spheres in 2D and 3D. For those materials, empirical equations were found that describe the discharge characteristics. Softness adds qualitatively new features to the dynamics and to the character of the flow. We report a study of the outflow of soft, practically frictionless hydrogel spheres from a quasi-2D bin. Prominent features are intermittent clogs, peculiar flow fields in the container, and a pronounced dependence of the flow rate and clogging statistics on the container fill height. The latter is a consequence of the ineffectiveness of Janssen's law: the pressure at the bottom of a bin containing hydrogel spheres grows linearly with the fill height.

Experimental study on detection of electrostatic discharges generated by polymer granules inside a metal silo

Science.gov (United States)

Choi, Kwangseok; Mogami, Tomofumi; Suzuki, Teruo

2014-04-01

To detect electrostatic discharges generated by polymer granules within a metal silo, we developed a novel and simple electrostatic discharge detector that utilizes a photosensor. The novel detector consists of a photosensor module in a metal cylinder, an optical band-pass filter, a quartz glass, a power supply, an amplifier for the photosensor module, and a digital oscilloscope. In this study, we conducted experiments at a real pneumatic powder transport facility that includes a metal silo to evaluate the novel detector using polypropylene granules. To determine the performance of the novel detector, we observed the electrostatic discharge within the metal silo using a conventional image intensifier system. The results obtained from the experiments show that the novel detector worked well in this study. The signals obtained with the novel detector were identical to the electrostatic discharges obtained with the conventional image intensifier system. The greatest advantage of this novel detector is that it is effective even when placed under external lights. In addition, the influence of various optical band-pass filters on the performance of the novel detector was discussed. Our study confirmed that an optical band-pass filter with a center wavelength of λ 330 nm (λ1/2: 315-345 nm) was the best performer among the optical band-pass filters used in this study.

Case study: evaluation of continuos blending silos in the cement industry, by the aid of tracer techniques

International Nuclear Information System (INIS)

Sebastian, C.; Maghella, G.; Mamani, E.

2000-12-01

Besides the actual burning process in cement manufacture, particular importance is attached to raw material preparation and homogenization, not only because of the quality of the kiln fed and therefore of the produced cement, but also because of the economy of the kiln operation, which significantly depends on the uniformity of the chemical composition of the material. As a result, the blending process of the cement raw material, before burning, is a basic stage of cement technology production. In this case, the pneumatic homogenization process is studied in a silo with a great storing and processing capacity. The objective is to evaluate the parameters which influence in the continuos operation. The method allows us to determine the optimal blending parameters, through the observation of the movement and distribution of the different fractions of fine dust raw meal, labelled with La-140 as tracer. Changes in blending according to time are discussed as well as the influence of the silo design on the degree of homogenization. It was showed that the silo blending operation has a strong influence on the production of good-quality cement as well as the implications on energy saving

Impacts of Woody Invader Dillenia suffruticosa (Griff. Martelli on Physio-chemical Properties of Soil and, Below and Above Ground Flora

Directory of Open Access Journals (Sweden)

B.A.K. Wickramathilake

2014-01-01

Full Text Available Dillenia suffruticosa (Griffith Martelli, that spreads fast in low-lying areas in wet zone of Sri Lanka is currently listed as a nationally important Invasive Alien Species that deserves attention in ecological studies. Thus, impact of this woody invader on physical, chemical properties of soil and below and above ground flora was investigated. Five sampling sites were identified along a distance of 46km from Avissawella to Ratnapura. At each site, two adjacent plots [1m x10m each for D. suffruticosa present (D+ and absent (D-] were outlined. Physical and chemical soil parameters, microbial biomass and number of bacterial colonies in soil were determined using standard procedures and compared between D+ and D- by ANOVA using SPSS. Rate of decomposition of D. suffruticosa leaves was also determined using the litter bag technique at 35% and 50% moisture levels. Above ground plant species richness in sample stands was compared using Jaccard and Sorenson diversity indices.  Decomposition of D. suffruticosa leaves was slow, but occurred at a more or less similar rate irrespective of moisture content of soil. Particle size distribution in D+ soil showed a much higher percentage of large soil particles.  Higher % porosity in D+ sites was a clear indication that the soil was aerated.  The pH was significantly lower for D+ than D- thus developing acidic soils whereas conductivity has been significantly high making soil further stressed. The significant drop in Cation Exchange Capacity (CEC in D+ soil was a remarkable finding to be concerned with as it correlated with fertility of soil. Significantly higher values of phosphates reported in D+ soil support the idea that plant invaders are capable to increase phosphates in soil. Higher biomass values recorded for D+ sites together with higher number of bacterial colonies could be related to the unexpectedly recorded higher Organic Carbon. Both  the  Jaccard  and  Sorenson   indices indicated  that

Estimating the CO2 mitigation potential of horizontal Ground Source Heat Pumps in the UK

Science.gov (United States)

Garcia-Gonzalez, R.; Verhoef, A.; Vidale, P. L.; Gan, G.; Chong, A.; Clark, D.

2012-04-01

By 2020, the UK will need to generate 15% of its energy from renewables to meet our contribution to the EU renewable energy target. Heating and cooling systems of buildings account for 30%-50% of the global energy consumption; thus, alternative low-carbon technologies such as horizontal Ground Couple Heat Pumps (GCHPs) can contribute to the reduction of anthropogenic CO2 emissions. Horizontal GCHPs currently represent a small fraction of the total energy generation in the UK. However, the fact that semi-detached and detached dwellings represent approximately 40% of the total housing stocks in the UK could make the widespread implementation of this technology particularly attractive in the UK and so could significantly increase its renewable energy generation potential. Using a simulation model, we analysed the dynamic interactions between the environment, the horizontal GCHP heat exchanger and typical UK dwellings, as well as their combined effect on heat pump performance and CO2 mitigation potential. For this purpose, a land surface model (JULES, Joint UK Land Environment Simulator), which calculates coupled soil heat and water fluxes, was combined with a heat extraction model. The analyses took into account the spatio-temporal variability of soil properties (thermal and hydraulic) and meteorological variables, as well as different horizontal GCHP configurations and a variety of building loads and heat demands. Sensitivity tests were performed for four sites in the UK with different climate and soil properties. Our results show that an installation depth of 1.0m would give us higher heat extractions rates, however it would be preferable to install the pipes slightly deeper to avoid the seasonal influence of variable meteorological conditions. A value of 1.5m for the spacing between coils (S) for a slinky configuration type is recommended to avoid thermal disturbances between neighbouring coils. We also found that for larger values of the spacing between the coils

Evaluation of drought and UV radiation impacts on above-ground biomass of mountain grassland by spectral reflectance and thermal imaging techniques

Czech Academy of Sciences Publication Activity Database

Novotná, Kateřina; Klem, Karel; Holub, Petr; Rapantová, Barbora; Urban, Otmar

2016-01-01

Roč. 9, 1-2 (2016), s. 21-30 ISSN 1803-2451 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : above-ground biomass * drought stress * grassland * UV radiation * precipitation * spectral reflectance * thermal imaging Subject RIV: EH - Ecology, Behaviour

El tabernáculo de la Catedral de Granada: de Diego de Siloe a Navas Parejo

Directory of Open Access Journals (Sweden)

José Antonio Peinado Guzmán

2010-03-01

Full Text Available Uno de los elementos más olvidados en los estudios acerca de la Catedral de Granada, ha sido, históricamente, el tabernáculo de su Capilla Mayor. El ideado por Diego de Siloe en 1561, supuso la creación de un elemento innovador dentro del ornato de su presbiterio. Este ciborio, venía a completar un programa iconográfico-teológico cargado de simbolismos. El paso del tiempo hizo que tuviese que ser sustituido por otros. Tras el de Siloe, tenemos referencias de la adquisición de uno en 1648 con forma de «Carro de Ezequiel», otro provisional en 1804 y, finalmente, el actual, hecho por Navas Parejo entre 1924-1929.

A first map of tropical Africa's above-ground biomass derived from satellite imagery

International Nuclear Information System (INIS)

Baccini, A; Laporte, N; Goetz, S J; Sun, M; Dong, H

2008-01-01

Observations from the moderate resolution imaging spectroradiometer (MODIS) were used in combination with a large data set of field measurements to map woody above-ground biomass (AGB) across tropical Africa. We generated a best-quality cloud-free mosaic of MODIS satellite reflectance observations for the period 2000-2003 and used a regression tree model to predict AGB at 1 km resolution. Results based on a cross-validation approach show that the model explained 82% of the variance in AGB, with a root mean square error of 50.5 Mg ha -1 for a range of biomass between 0 and 454 Mg ha -1 . Analysis of lidar metrics from the Geoscience Laser Altimetry System (GLAS), which are sensitive to vegetation structure, indicate that the model successfully captured the regional distribution of AGB. The results showed a strong positive correlation (R 2 = 0.90) between the GLAS height metrics and predicted AGB.

Semianalytical Solution and Parameters Sensitivity Analysis of Shallow Shield Tunneling-Induced Ground Settlement

Directory of Open Access Journals (Sweden)

Jifeng Liu

2017-01-01

Full Text Available The influence of boundary soil properties on tunneling-induced ground settlement is generally not considered in current analytic solutions, and the hypothesis of equal initial stress in vertical and horizontal makes the application of the above solutions limited. Based on the homogeneous half-plane hypothesis, by defining the boundary condition according to the ground loss pattern in shallow tunnel, and with the use of Mohr-Coulomb plastic yielding criteria and classic Lame and Kiersch elastic equations by separating the nonuniform stress field to uniform and single-direction stress field, a semiempirical solution for ground settlement induced by single shallow circular tunnel is presented and sensitivity to the ground parameters is analyzed. The methods of settlement control are offered by influence factors analysis of semiempirical solution. A case study in Beijing Metro tunnel shows that the semiempirical solution agrees well with the in situ measured results.

De portadas y retablos: Siloe y Vandelvira

Directory of Open Access Journals (Sweden)

Luz de Ulierte Vázquez

2009-12-01

Full Text Available Partiendo de Siloe y su portada del Perdón de la Catedral de Granada, Andrés de Vandelvira realiza con ciertas diferencias la principal del Salvador de Úbeda, convirtiéndola en una portada-retablo. La obra será punto de partida para una serie de portadas giennenses y para la introducción del lenguaje del retablo como arquitectura en la provincia de Jaén. En la de Granada, aparte de en Guadahortuna, la del Perdón no tendrá descendencia directa: el paradigma para las parroquiales de la provincia será el tipo de otras portadas de su Catedral, y sus retablos se convertirán al lenguaje arquitectónico algo más tardíamente.

Towards ground-truthing of spaceborne estimates of above-ground life biomass and leaf area index in tropical rain forests

Directory of Open Access Journals (Sweden)

P. Köhler

2010-08-01

Full Text Available The canopy height h of forests is a key variable which can be obtained using air- or spaceborne remote sensing techniques such as radar interferometry or LIDAR. If new allometric relationships between canopy height and the biomass stored in the vegetation can be established this would offer the possibility for a global monitoring of the above-ground carbon content on land. In the absence of adequate field data we use simulation results of a tropical rain forest growth model to propose what degree of information might be generated from canopy height and thus to enable ground-truthing of potential future satellite observations. We here analyse the correlation between canopy height in a tropical rain forest with other structural characteristics, such as above-ground life biomass (AGB (and thus carbon content of vegetation and leaf area index (LAI and identify how correlation and uncertainty vary for two different spatial scales. The process-based forest growth model FORMIND2.0 was applied to simulate (a undisturbed forest growth and (b a wide range of possible disturbance regimes typically for local tree logging conditions for a tropical rain forest site on Borneo (Sabah, Malaysia in South-East Asia. In both undisturbed and disturbed forests AGB can be expressed as a power-law function of canopy height h (AGB = a · h^b with an r² ~ 60% if data are analysed in a spatial resolution of 20 m × 20 m (0.04 ha, also called plot size. The correlation coefficient of the regression is becoming significant better in the disturbed forest sites (r² = 91% if data are analysed hectare wide. There seems to exist no functional dependency between LAI and canopy height, but there is also a linear correlation (r² ~ 60% between AGB and the area fraction of gaps in which the canopy is highly disturbed. A reasonable agreement of our results with observations is obtained from a

Towards ground-truthing of spaceborne estimates of above-ground life biomass and leaf area index in tropical rain forests

Science.gov (United States)

Köhler, P.; Huth, A.

2010-08-01

The canopy height h of forests is a key variable which can be obtained using air- or spaceborne remote sensing techniques such as radar interferometry or LIDAR. If new allometric relationships between canopy height and the biomass stored in the vegetation can be established this would offer the possibility for a global monitoring of the above-ground carbon content on land. In the absence of adequate field data we use simulation results of a tropical rain forest growth model to propose what degree of information might be generated from canopy height and thus to enable ground-truthing of potential future satellite observations. We here analyse the correlation between canopy height in a tropical rain forest with other structural characteristics, such as above-ground life biomass (AGB) (and thus carbon content of vegetation) and leaf area index (LAI) and identify how correlation and uncertainty vary for two different spatial scales. The process-based forest growth model FORMIND2.0 was applied to simulate (a) undisturbed forest growth and (b) a wide range of possible disturbance regimes typically for local tree logging conditions for a tropical rain forest site on Borneo (Sabah, Malaysia) in South-East Asia. In both undisturbed and disturbed forests AGB can be expressed as a power-law function of canopy height h (AGB = a · hb) with an r2 ~ 60% if data are analysed in a spatial resolution of 20 m × 20 m (0.04 ha, also called plot size). The correlation coefficient of the regression is becoming significant better in the disturbed forest sites (r2 = 91%) if data are analysed hectare wide. There seems to exist no functional dependency between LAI and canopy height, but there is also a linear correlation (r2 ~ 60%) between AGB and the area fraction of gaps in which the canopy is highly disturbed. A reasonable agreement of our results with observations is obtained from a comparison of the simulations with permanent sampling plot (PSP) data from the same region and with the

Physical Characterisation and Quantification of Total Above Ground Biomass Derived from First Thinnings for Wood Fuel Consumption in Ireland

OpenAIRE

Mockler, Nicholas

2013-01-01

Comprehensive knowledge of wood fuel properties assists in the optimisation of operations concerned with the harvesting, seasoning, processing and conversion of wood to energy. This study investigated the physical properties of wood fuel. These properties included moisture content and basic density. The field work also allowed for the quantification of above ground biomass partitions. The species investigated were alder (Alnus glutinosa), ash (Fraxinus excelsior L.), birch (Betula spp.), lodg...

Dosimetry of Rn-222 in the air in environments located above and below ground level

International Nuclear Information System (INIS)

Cazula, Camila Dias

2015-01-01

Exposure of the general population to ionizing radiation comes mainly from natural sources. The main contribution is due to inhalation of radon (Rn-222), a gas that occurs naturally (UNSCEAR, 2000). The Rn-222 concentration in the environment is controlled by factors such as soil permeability and water content, the weather variability, materials used in the foundation and the usual positive pressure differential between the soil and the internal environment. Studies indicate that the concentration of radon shows a wide variation in the basement, ground floor and upper floors of buildings. The objective of this study is to determine radon levels in basements, ground floor and floors above ground level, at a university in the city of Sao Paulo and in one residential building in the city of Peruibe. Rn-222 measurements were performed using the method with nuclear track of solid state detectors (CR-39). The studied environments present Rn-222 concentration well below the values recommended by the International Commission on Radiological Protection, published in the 2009 document, of 300 Bq/m 3 for homes and 1000 Bq/m 3 for the workplace. In the residential building, the concentration of Ra-266, Th-232 and K-40 in the materials used in the building construction was also analyzed, by gamma spectrometry. The effective total dose for the resident due to external exposure was 0.8 mSv y -1 , lower than the annual dose limit for the general public of 1 mSv y -1 . (author)

Exerimental study on the water permeability of a reinforced concrete silo for radioactive waste repository

International Nuclear Information System (INIS)

Iriya, K.; Itoh, Y.; Hosoda, M.; Fujiwara, A.; Tsuji, Y.

1992-01-01

A low permeable conrete structure is required in a shallow land disposal system in order to isolate radioactive waste from the biosphere. Two model silos (7.25 m dia., 5.25 m height, 1.50 m wall thickness) will be constructed to demonstrate the performance of the concrete structure constructed by the two concepts. One concept is called the improved grouting method. We intend to inject cementitious material to the defective zone such as a crack after its construction by an ordinary construction method. The other concept is called the improved constructing method. We intend to minimize the defective zone, which influences the permeability, during the construction by an improved constructing method. The permeability of the concrete structure as a whole structure will be assessed by two large-scale-model-silos until 1992. The design, objectives, and preliminary results of this experiment are mainly described in this paper. (orig.)

Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production

Science.gov (United States)

Morin, Jean-Benoît; Gimenez, Philippe; Edouard, Pascal; Arnal, Pierrick; Jiménez-Reyes, Pedro; Samozino, Pierre; Brughelli, Matt; Mendiguchia, Jurdan

2015-01-01

Recent literature supports the importance of horizontal ground reaction force (GRF) production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG) activity of the vastus lateralis, rectus femoris, biceps femoris, and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024) between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability. PMID:26733889

Sprint acceleration mechanics: the major role of hamstrings in horizontal force production

Directory of Open Access Journals (Sweden)

Jean-Benoit eMORIN

2015-12-01

Full Text Available Recent literature supports the importance of horizontal ground reaction force (GRF production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG activity of the vastus lateralis, rectus femoris, biceps femoris and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024 between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability.

Economic analysis of using above ground gas storage devices for compressed air energy storage system

Science.gov (United States)

Liu, Jinchao; Zhang, Xinjing; Xu, Yujie; Chen, Zongyan; Chen, Haisheng; Tan, Chunqing

2014-12-01

Above ground gas storage devices for compressed air energy storage (CAES) have three types: air storage tanks, gas cylinders, and gas storage pipelines. A cost model of these gas storage devices is established on the basis of whole life cycle cost (LCC) analysis. The optimum parameters of the three types are determined by calculating the theoretical metallic raw material consumption of these three devices and considering the difficulties in manufacture and the influence of gas storage device number. The LCCs of the three types are comprehensively analyzed and compared. The result reveal that the cost of the gas storage pipeline type is lower than that of the other two types. This study may serve as a reference for designing large-scale CAES systems.

Coeficiente de transferência de carga nas fundações de silos verticais cilíndricos

Directory of Open Access Journals (Sweden)

Marivone Z. Fank

2015-09-01

Full Text Available RESUMOO dimensionamento das estruturas armazenadoras de grãos carece de uma norma brasileira que prescreva sobre seus projetos e ações; contudo, existem muitas lacunas no estado atual do conhecimento sendo imprescindíveis pesquisas adicionais sobre o tema. Com o objetivo de determinar a distribuição das cargas nas fundações dos silos foram instrumentadas, por meio de células de carga, quatro estacas localizadas sob o anel de um silo protótipo. O experimento ocorreu durante o período de agosto a dezembro de 2009 em Palotina, PR. As leituras das células foram realizadas por sistema automático de aquisição de dados durante o carregamento de grãos de milho e, a partir dos resultados, pode-se destacar um coeficiente de transferência médio de 0,30 para o anel até o carregamento de 44% do silo, a partir do qual ocorreu um incremento na taxa de transferência. As cargas máximas atuantes nas estacas instrumentadas foram de 800, 845, 520 e 600 kN, correspondentes a coeficientes de transferência de 0,48; 0,51; 0,31 e 0,36, respectivamente. Assim, o coeficiente regionalmente adotado de 0,30 para o dimensionamento das fundações do anel está subestimado fazendo-se necessária uma análise mais criteriosa nas taxas de transferência.

Fighting fire with gas. CO{sub 2} extinguishes smouldering fires in biomass silos and waste bunkers; Effizientes Feuerwehr-Gas. CO{sub 2} loescht Schwelbraende in Biomasse-Silos und Abfallbunkern

Energy Technology Data Exchange (ETDEWEB)

Anon.

2011-07-01

Organic materials are a great source of energy and so biomass is in big demand. But wherever large amounts of wood, waste and straw are stored in huge silos, there is also a risk of smouldering fires and even explosions. Conventional methods are relatively ineffective at extinguishing fires such as these. But a new extinguishing system from Linde uses CO{sub 2} to effectively fight smouldering fires at the source. (orig.)

Ground deformation at collapse calderas: influence of host rock lithology and reservoir multiplicity

Energy Technology Data Exchange (ETDEWEB)

Geyer, A; Gottsmann, J [Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen' s Road, BS8 1RJ, Bristol (United Kingdom)], E-mail: A.GeverTraver@bristol.ac.uk

2008-10-01

A variety of source mechanisms have been proposed to account for observed caldera deformation. Here we present a systematic set of new results from numerical forward modelling using a Finite Element Method. which provides a link between measured ground deformation and the inaccessible deformation source. We simulate surface displacements due to pressure changes in a shallow oblate reservoir overlain by host rock with variable mechanical properties. We find that the amplitude and wavelength of resultant ground deformation is dependent on the distribution of mechanically stiff and soft lithologies and their relative distribution above a reservoir. In addition, we note an influence of layering on the critical ratio of horizontal over vertical displacements, a criterion employed to discriminate between different finite source geometries.

Reduction of horizontal wind speed in a boundary layer with obstacles

DEFF Research Database (Denmark)

Emeis, S.; Frandsen, S.

1993-01-01

The reduction of horizontal wind speed at hub height in an infinite cluster of wind turbines is computed from a balance between a loss of horizontal momentum due to the drag and replenishment from above by turbulent fluxes. This reduction is derived without assumptions concerning the vertical wind...... profile above or below hub height, only some basic assumptions on turbulent exchange have been made. Two applications of the result are presented, one considering wind turbines and one pressure drag on orographic obstacles in the atmospheric boundary layer. Both applications are basically governed...... by the same kind of momentum balance....

Evaluation and summary of seismic response of above ground nuclear power plant piping to strong motion earthquakes

International Nuclear Information System (INIS)

Stevenson, J.D.

1985-01-01

The purpose of this paper is to summarize the observations and experience which has been developed relative to the seismic behavior of above-ground, building-supported, industrial type piping (similar to piping used in nuclear power plants) in strong motion earthquakes. The paper also contains observations regarding the response of piping in experimental tests which attempted to excite the piping to failure. Appropriate conclusions regarding the behavior of such piping in large earthquakes and recommendations as to future design of such piping to resist earthquake motion damage are presented based on observed behavior in large earthquakes and simulated shake table testing

Relationships between ground reaction impulse and sprint acceleration performance in team sport athletes.

Science.gov (United States)

Kawamori, Naoki; Nosaka, Kazunori; Newton, Robert U

2013-03-01

Large horizontal acceleration in short sprints is a critical performance parameter for many team sport athletes. It is often stated that producing large horizontal impulse at each ground contact is essential for high short sprint performance, but the optimal pattern of horizontal and vertical impulses is not well understood, especially when the sprints are initiated from a standing start. This study was an investigation of the relationships between ground reaction impulses and sprint acceleration performance from a standing start in team sport athletes. Thirty physically active young men with team sport background performed 10-m sprint from a standing start, whereas sprint time and ground reaction forces were recorded during the first ground contact and at 8 m from the start. Associations between sprint time and ground reaction impulses (normalized to body mass) were determined by a Pearson's correlation coefficient (r) analysis. The 10-m sprint time was significantly (p < 0.01) correlated with net horizontal impulse (r = -0.52) and propulsive impulse (r = -0.66) measured at 8 m from the start. No significant correlations were found between sprint time and impulses recorded during the first ground contact after the start. These results suggest that applying ground reaction impulse in a more horizontal direction is important for sprint acceleration from a standing start. This is consistent with the hypothesis of training to increase net horizontal impulse production using sled towing or using elastic resistance devices, which needs to be validated by future longitudinal training studies.

Quantitative Estimation of Above Ground Crop Biomass using Ground-based, Airborne and Spaceborne Low Frequency Polarimetric Synthetic Aperture Radar

Science.gov (United States)

Koyama, C.; Watanabe, M.; Shimada, M.

2016-12-01

Estimation of crop biomass is one of the important challenges in environmental remote sensing related to agricultural as well as hydrological and meteorological applications. Usually passive optical data (photographs, spectral data) operating in the visible and near-infrared bands is used for such purposes. The virtue of optical remote sensing for yield estimation, however, is rather limited as the visible light can only provide information about the chemical characteristics of the canopy surface. Low frequency microwave signals with wavelength longer 20 cm have the potential to penetrate through the canopy and provide information about the whole vertical structure of vegetation from the top of the canopy down to the very soil surface. This phenomenon has been well known and exploited to detect targets under vegetation in the military radar application known as FOPEN (foliage penetration). With the availability of polarimetric interferometric SAR data the use PolInSAR techniques to retrieve vertical vegetation structures has become an attractive tool. However, PolInSAR is still highly experimental and suitable data is not yet widely available. In this study we focus on the use of operational dual-polarization L-band (1.27 GHz) SAR which is since the launch of Japan's Advanced Land Observing Satellite (ALOS, 2006-2011) available worldwide. Since 2014 ALOS-2 continues to deliver such kind of partial polarimetric data for the entire land surface. In addition to these spaceborne data sets we use airborne L-band SAR data acquired by the Japanese Pi-SAR-L2 as well as ultra-wideband (UWB) ground based SAR data operating in the frequency range from 1-4 GHz. By exploiting the complex dual-polarization [C2] Covariance matrix information, the scattering contributions from the canopy can be well separated from the ground reflections allowing for the establishment of semi-empirical relationships between measured radar reflectivity and the amount of fresh-weight above-ground

Forecasting Global Horizontal Irradiance Using the LETKF and a Combination of Advected Satellite Images and Sparse Ground Sensors

Science.gov (United States)

Harty, T. M.; Lorenzo, A.; Holmgren, W.; Morzfeld, M.

2017-12-01

The irradiance incident on a solar panel is the main factor in determining the power output of that panel. For this reason, accurate global horizontal irradiance (GHI) estimates and forecasts are critical when determining the optimal location for a solar power plant, forecasting utility scale solar power production, or forecasting distributed, behind the meter rooftop solar power production. Satellite images provide a basis for producing the GHI estimates needed to undertake these objectives. The focus of this work is to combine satellite derived GHI estimates with ground sensor measurements and an advection model. The idea is to use accurate but sparsely distributed ground sensors to improve satellite derived GHI estimates which can cover large areas (the size of a city or a region of the United States). We use a Bayesian framework to perform the data assimilation, which enables us to produce irradiance forecasts and associated uncertainties which incorporate both satellite and ground sensor data. Within this framework, we utilize satellite images taken from the GOES-15 geostationary satellite (available every 15-30 minutes) as well as ground data taken from irradiance sensors and rooftop solar arrays (available every 5 minutes). The advection model, driven by wind forecasts from a numerical weather model, simulates cloud motion between measurements. We use the Local Ensemble Transform Kalman Filter (LETKF) to perform the data assimilation. We present preliminary results towards making such a system useful in an operational context. We explain how localization and inflation in the LETKF, perturbations of wind-fields, and random perturbations of the advection model, affect the accuracy of our estimates and forecasts. We present experiments showing the accuracy of our forecasted GHI over forecast-horizons of 15 mins to 1 hr. The limitations of our approach and future improvements are also discussed.

Predictive modeling of hazardous waste landfill total above-ground biomass using passive optical and LIDAR remotely sensed data

Science.gov (United States)

Hadley, Brian Christopher

This dissertation assessed remotely sensed data and geospatial modeling technique(s) to map the spatial distribution of total above-ground biomass present on the surface of the Savannah River National Laboratory's (SRNL) Mixed Waste Management Facility (MWMF) hazardous waste landfill. Ordinary least squares (OLS) regression, regression kriging, and tree-structured regression were employed to model the empirical relationship between in-situ measured Bahia (Paspalum notatum Flugge) and Centipede [Eremochloa ophiuroides (Munro) Hack.] grass biomass against an assortment of explanatory variables extracted from fine spatial resolution passive optical and LIDAR remotely sensed data. Explanatory variables included: (1) discrete channels of visible, near-infrared (NIR), and short-wave infrared (SWIR) reflectance, (2) spectral vegetation indices (SVI), (3) spectral mixture analysis (SMA) modeled fractions, (4) narrow-band derivative-based vegetation indices, and (5) LIDAR derived topographic variables (i.e. elevation, slope, and aspect). Results showed that a linear combination of the first- (1DZ_DGVI), second- (2DZ_DGVI), and third-derivative of green vegetation indices (3DZ_DGVI) calculated from hyperspectral data recorded over the 400--960 nm wavelengths of the electromagnetic spectrum explained the largest percentage of statistical variation (R2 = 0.5184) in the total above-ground biomass measurements. In general, the topographic variables did not correlate well with the MWMF biomass data, accounting for less than five percent of the statistical variation. It was concluded that tree-structured regression represented the optimum geospatial modeling technique due to a combination of model performance and efficiency/flexibility factors.

Breaking down IT silos: a "connected" way to improve customer experience and the bottom line.

Science.gov (United States)

Hallowell, Bruce; Turisco, Frances

2009-03-01

Hospitals can provide customer service like Amazon.com without purchasing new technology. Making technology interactive requires sharing patient data across applications and enhancing existing IT with decision support. Breaking down technology silos between hospital and outpatient care provider systems significantly improves efficiency, lowers costs, and speeds care delivery.

The spring 2011 final stratospheric warming above Eureka: anomalous dynamics and chemistry

Directory of Open Access Journals (Sweden)

C. Adams

2013-01-01

Full Text Available In spring 2011, the Arctic polar vortex was stronger than in any other year on record. As the polar vortex started to break up in April, ozone and NO₂ columns were measured with UV-visible spectrometers above the Polar Environment Atmospheric Research Laboratory (PEARL in Eureka, Canada (80.05° N, 86.42° W using the differential optical absorption spectroscopy (DOAS technique. These ground-based column measurements were complemented by Ozone Monitoring Instrument (OMI and Optical Spectrograph and Infra-Red Imager System (OSIRIS satellite measurements, Global Modeling Initiative (GMI simulations, and meteorological quantities. On 8 April 2011, NO₂ columns above PEARL from the DOAS, OMI, and GMI datasets were approximately twice as large as in previous years. On this day, temperatures and ozone volume mixing ratios above Eureka were high, suggesting enhanced chemical production of NO₂ from NO. Additionally, GMI NO_x (NO + NO₂ and N₂O fields suggest that downward transport along the vortex edge and horizontal transport from lower latitudes also contributed to the enhanced NO₂. The anticyclone that transported lower-latitude NO_x above PEARL became frozen-in and persisted in dynamical and GMI N₂O fields until the end of the measurement period on 31 May 2011. Ozone isolated within this frozen-in anticyclone (FrIAC in the middle stratosphere was lost due to reactions with the enhanced NO_x. Below the FrIAC (from the tropopause to 700 K, NO_x driven ozone loss above Eureka was larger than in previous years, according to GMI monthly average ozone loss rates. Using the passive tracer technique, with passive ozone profiles from the Lagrangian Chemistry and Transport Model, ATLAS, ozone losses since 1 December 2010 were calculated at 600 K. In the air mass that was above Eureka on 20 May 2011, ozone losses reached 4.2 parts per million by

Remediation of a contaminated thin aquifer by horizontal wells

Energy Technology Data Exchange (ETDEWEB)

Breh, W.; Suttheimer, J.; Hoetzl, H. [Univ. of Karlsruhe (Germany); Frank, K. [GEO-Service GmbH, Rheinmuenster (Germany)

1997-12-31

At an industrial site in Bruchsal (Germany) a huge trichloroethene contamination was found. After common remedial actions proved to be widely ineffective, new investigations led to a highly contaminated thin aquifer above the main aquifer. The investigation and the beginning of the remediation of the thin aquifer by two horizontal wells is described in this paper. Special attention was given to the dependence between precipitation and the flow direction in the thin aquifer and to hydraulic connections between the thin and the main aquifer. Also a short introduction into a new remedial technique by horizontal wells and first results of the test phase of the horizontal wells are given.

PENGEMBANGAN PRODUK OLAHAN KOPI DI DESA SIDOMULYO KECAMATAN SILO KABUPATEN JEMBER

Directory of Open Access Journals (Sweden)

Yuli Hariyati

2014-04-01

Full Text Available ABSTRAKKopi (Coffea spp. L. merupakan komoditi perkebunan yang strategis. Kopi rakyat tersebar di beberapa kecamatan di Kabupaten Jember, terutama di Kalisat dan Silo. Adanya faktor pendorong dan faktor penghambat pada pengolahan produk olahan kopi dapat dirumuskan suatu rekomendasi kebijakan pengembangan produk olahan kopi, dimana meningkatkan faktor pendorong dan meminimalisir faktor penghambat. Penelitian ini bertujuan untuk mengetahui rekomendasi kebijakan pada pengembangan pengolahan kopi di Desa Sidomulyo Kecamatan Silo Kabupaten Jember. Metode penelitian yang digunakan adalah metode deskriptif dan metode analitis. Analisis data yang digunakan adalah analisis medan kekuatan. Hasil penelitian menunjukkan bahwa faktor pendorong tertinggi adalah motivasi petani yang tinggi dengan nilai faktor urgensi sebesar 1,74, sedangkan faktor penghambat tertinggi adalah bahan baku yang diolah terbatas dengan nilai faktor urgensi sebesar 1,42. Rekomendasi yang sebaiknya diterapkan untuk mendukung faktor pendorong adalah melakukan penyuluhan secara berkesinambungan, sedangkan rekomendasi sebagai solusi faktor penghambat adalah menjalin kerja sama dengan petani olah basah yang belum melakukan olah basah untuk melakukan olah basah  guna menjaga ketersediaan kopi olah basah dan menambah modal bagi unit usaha produksi pada koperasi ABSTRACTCoffee (Coffea spp. L. is one of a strategic commodity. The coffee public plantation is spread out to some sub-districts in Jember, especially in Kalisat and Silo. The existence of factors driving and inhibiting factors in the processing of coffee processed products can be formulated a policy recommendation development of processed coffee products, which enhance the driving factors and minimize the inhibiting factors. This study aims to determine policy recommendations on the development of coffee cultivation in the village of Shiloh Sidomulyo Jember District. The method used is descriptive method and analytical methods

Effect of Nitrogen Fertilizers on the Lysine Synthesis in Silo-Maize

Energy Technology Data Exchange (ETDEWEB)

Cencelj, J.; Jelenic, Dj. [Institute for the Application of Nuclear Energy in Agriculture, Veterinary Medicine and Forestry, Belgrade, Yugoslavia (Serbia)

1968-07-01

In investigations on amino acids of silo-maize, different nitrogen fertilizers were studied to determine their effect on amino acid composition and variation during the growth period. The experiment was carried out with silo-maize, hybrid W 464A, grown on sandy soil, which had not been treated for six years with either fertilizers or manure. Before cultivation phosphorus and potassium fertilizers were applied, and the nitrogen fertilizers, ammonium sulphate, ammonium nitrate, calcium cyanamide and urea, were applied at the most appropriate time of application. The first samples were taken at the time of flowering, the second after flowering, and the third, fourth and fifth in the lactic, wax, and full maturity phases, respectively. The percentages of crude protein of the maize gradually decreased while the nitrogen-free extraction matter increased during this period. The protein content of the maize was highest with sodium nitrate and urea fertilization and lowest when calcium cyanamide was used. Investigations to determine whether or not an increase in crude protein content was correlated with an increased content of lysine have shown that there is a correlation when plants are fertilized with calcium cyanamide. The content of essential amino acids was more satisfactory in plants fertilized with urea than with sodium nitrate. According to the statistical analysis, the best improvement in lysine content was obtained with urea (0.23%), the least satisfactory with calcium cyanamide (0.17%), and PK fertilizers without nitrogen (0.15%). (author)

Atmospheric horizontal divergence and diffusion

International Nuclear Information System (INIS)

Castans, M.

1981-01-01

The action of horizontal divergence on diffusion near the ground is established through.a very simple flow model. The shape of the well-known Pasquill-Gifford-Turner curves, that apparently take account in some way of divergence, is justified. The possibility of explaining the discre--pancies between the conventional straight line model and experimental results, mainly under low-wind-speed satable conditions, is considered. Some hints for further research are made. (auth.)

Above-ground biomass models for Seabuckthorn (Hippophae salicifolia) in Mustang District, Nepal

DEFF Research Database (Denmark)

Rajchal, Rajesh; Meilby, Henrik

2013-01-01

weight of fruit and oven-dry weight of wood (stem and branches) and leaves were measured and used as a basis for developing biomass models. Diameters of the trees were measured at 30 cm above ground whereas the heights were measured in terms of the total tree height (m). Among several models tested......, the models suggested for local use were: ln(woody biomass, oven-dry, kg) = -3.083 + 2.436 ln(diameter, cm), ln (fruit biomass, fresh, kg) = -3.237 + 1.346 ln(diameter, cm) and ln(leaf biomass, oven-dry, kg) = -4.013 + 1.403 ln(Diameter, cm) with adjusted coefficients of determination of 0.99, 0.73 and 0.......91 for wood, fruit, and leaves, respectively. The models suggested for a slightly broader range of environmental conditions were: ln (woody biomass, oven-dry, kg) = -3.277 + 0.924 ln(diameter2 × height), ln(Fruit biomass, fresh, kg) = -3.146 + 0.485 ln(diameter2 × height) and ln(leaf biomass, oven-dry, kg...

Irradiation testing of LEU fuels in the SILOE Reactor - Progress report

International Nuclear Information System (INIS)

Merchie, Francis; Baas, Claude; Martel, Patrick

1985-01-01

Irradiation of uranium-silicide fuels has continued in the SILOE reactor during the past year. Thickness vs. fission density data from four U 3 Si plates containing 5.5 and 6.0 g U/cm 3 have been analyzed, and the results are presented. The irradiation of a full 60 g U/cm 3 U 3 Si element has begun. In addition, four U 3 Si 2 plates containing 20 to 54 g U/cm 3 are now being irradiated. These irradiations and future plans are discussed in the paper. (author)

Potential of ALOS2 and NDVI to Estimate Forest Above-Ground Biomass, and Comparison with Lidar-Derived Estimates

Directory of Open Access Journals (Sweden)

Gaia Vaglio Laurin

2016-12-01

Full Text Available Remote sensing supports carbon estimation, allowing the upscaling of field measurements to large extents. Lidar is considered the premier instrument to estimate above ground biomass, but data are expensive and collected on-demand, with limited spatial and temporal coverage. The previous JERS and ALOS SAR satellites data were extensively employed to model forest biomass, with literature suggesting signal saturation at low-moderate biomass values, and an influence of plot size on estimates accuracy. The ALOS2 continuity mission since May 2014 produces data with improved features with respect to the former ALOS, such as increased spatial resolution and reduced revisit time. We used ALOS2 backscatter data, testing also the integration with additional features (SAR textures and NDVI from Landsat 8 data together with ground truth, to model and map above ground biomass in two mixed forest sites: Tahoe (California and Asiago (Alps. While texture was useful to improve the model performance, the best model was obtained using joined SAR and NDVI (R2 equal to 0.66. In this model, only a slight saturation was observed, at higher levels than what usually reported in literature for SAR; the trend requires further investigation but the model confirmed the complementarity of optical and SAR datatypes. For comparison purposes, we also generated a biomass map for Asiago using lidar data, and considered a previous lidar-based study for Tahoe; in these areas, the observed R2 were 0.92 for Tahoe and 0.75 for Asiago, respectively. The quantitative comparison of the carbon stocks obtained with the two methods allows discussion of sensor suitability. The range of local variation captured by lidar is higher than those by SAR and NDVI, with the latter showing overestimation. However, this overestimation is very limited for one of the study areas, suggesting that when the purpose is the overall quantification of the stored carbon, especially in areas with high carbon

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

K. Coppersmith; R. Quittmeyer

2005-01-01

This report describes a scientific analysis to bound credible horizontal peak ground velocities (PGV) for the repository waste emplacement level at Yucca Mountain. Results are presented as a probability distribution for horizontal PGV to represent uncertainties in the analysis. The analysis also combines the bound to horizontal PGV with results of ground motion site-response modeling (BSC 2004 [DIRS 170027]) to develop a composite hazard curve for horizontal PGV at the waste emplacement level. This result provides input to an abstraction of seismic consequences (BSC 2004 [DIRS 169183]). The seismic consequence abstraction, in turn, defines the input data and computational algorithms for the seismic scenario class of the total system performance assessment (TSPA). Planning for the analysis is documented in Technical Work Plan TWP-MGR-GS-000001 (BSC 2004 [DIRS 171850]). The bound on horizontal PGV at the repository waste emplacement level developed in this analysis complements ground motions developed on the basis of PSHA results. In the PSHA, ground motion experts characterized the epistemic uncertainty and aleatory variability in their ground motion interpretations. To characterize the aleatory variability they used unbounded lognormal distributions. As a consequence of these characterizations, as seismic hazard calculations are extended to lower and lower annual frequencies of being exceeded, the ground motion level increases without bound, eventually reaching levels that are not credible (Corradini 2003 [DIRS 171191]). To provide credible seismic inputs for TSPA, in accordance with 10 Code of Federal Regulations (CFR) 63.102(j) [DIRS 156605], this complementary analysis is carried out to determine reasonable bounding values of horizontal PGV at the waste emplacement level for annual frequencies of exceedance as low as 10 -8 . For each realization of the TSPA seismic scenario, the results of this analysis provide a constraint on the values sampled from the

Two-dimensional transport of dust from an infinite line source at ground level: non-zero roughness height

International Nuclear Information System (INIS)

Hassan, M.H.A.; Eltayeb, I.A.

1992-07-01

The previous study (Eltayeb and Hassan, 1992) of the two-dimensional diffusion equation of dust over a rough ground surface, which acts as a dust source of variable strength, under the influence of horizontal wind and gravitational attraction is here extended to all finite values of the roughness height Z 0 . An analytic expression is obtained for the concentration of dust for a general strength of the source. The result reduces to the previously known solutions as special cases. The expression for the concentration has been evaluated for some representative example of the source strength g(X). It is found that the concentration decreases with roughness height at any fixed point above ground level. (author). 4 refs, 2 figs

Mitigation potential of horizontal ground coupled heat pumps for current and future climatic conditions: UK environmental modelling and monitoring studies

Science.gov (United States)

García González, Raquel; Verhoef, Anne; Vidale, Pier Luigi; Gan, Guohui; Wu, Yupeng; Hughes, Andrew; Mansour, Majdi; Blyth, Eleanor; Finch, Jon; Main, Bruce

2010-05-01

An increased uptake of alternative low or non-CO2 emitting energy sources is one of the key priorities for policy makers to mitigate the effects of environmental change. Relatively little work has been undertaken on the mitigation potential of Ground Coupled Heat Pumps (GCHPs) despite the fact that a GCHP could significantly reduce CO2 emissions from heating systems. It is predicted that under climate change the most probable scenario is for UK temperatures to increase and for winter rainfall to become more abundant; the latter is likely to cause a general rise in groundwater levels. Summer rainfall may reduce considerably, while vegetation type and density may change. Furthermore, recent studies underline the likelihood of an increase in the number of heat waves. Under such a scenario, GCHPs will increasingly be used for cooling as well as heating. These factors will affect long-term performance of horizontal GCHP systems and hence their economic viability and mitigation potential during their life span ( 50 years). The seasonal temperature differences encountered in soil are harnessed by GCHPs to provide heating in the winter and cooling in the summer. The performance of a GCHP system will depend on technical factors (heat exchanger (HE) type, length, depth, and spacing of pipes), but also it will be determined to a large extent by interactions between the below-ground parts of the system and the environment (atmospheric conditions, vegetation and soil characteristics). Depending on the balance between extraction and rejection of heat from and to the ground, the soil temperature in the neighbourhood of the HE may fall or rise. The GROMIT project (GROund coupled heat pumps MITigation potential), funded by the Natural Environment Research Council (UK), is a multi-disciplinary research project, in collaboration with EarthEnergy Ltd., which aims to quantify the CO2 mitigation potential of horizontal GCHPs. It considers changing environmental conditions and combines

Influence of the environmental heterogeneity on the tree species richness –above ground biomass relationship in the Colombian Amazon

OpenAIRE

Posada Hernández , Carlos Alberto

2013-01-01

Abstract: In this study, we aimed to identify the shape and environmental drivers of the species richness (SR) –rarefied above ground biomass (RAGB) relationship across and within tree communities in the Colombian Amazon. We used a series of 130 0.1 ha plots to answer the next questions: 1) what is the shape of the SR - RAGB relationship both across and within tree communities in the Colombian Amazon? 2) At what extent does environmental heterogeneity drives the shape of the SR - RAGB relatio...

It's hard to play ball: A qualitative study of knowledge exchange and silo effects in public health.

Science.gov (United States)

Johnson, Rebecca; Grove, Amy; Clarke, Aileen

2018-01-02

Partnerships in public health form an important component of commissioning and implementing services, in England and internationally. In this research, we examine the views of staff involved in a City-wide health improvement programme which ran from 2009 to 2013 in England. We examine the practicalities of partnership work in community settings, and we describe some of barriers faced when implementing a large, multi-organisation health improvement programme. Qualitative, semi-structured interviews were performed. Purposive sampling was used to identify potential participants in the programme: programme board of directors, programme and project managers and intervention managers. Interviews were conducted one-to-one. We conducted a thematic analysis using the 'one sheet of paper' technique. This involved analysing data deductively, moving from initial to axial coding, developing categories and then identifying emerging themes. Fifteen interviews were completed. Three themes were identified. The first theme reflects how poor communication approaches hindered the ability of partnerships to deliver their aims and objectives in a range of ways and for a range of reasons. Our second theme reflects how a lack of appropriate knowledge exchange hindered decision-making, affected trust and contributed to protectionist approaches to working. This lack of shared, and communicated, understanding of what type of knowledge is most appropriate and in which circumstance made meaningful knowledge exchange challenging for decision-making and partnership-working in the City-wide health improvement programme. Theme three demonstrates how perceptions about silos in partnership-working could be problematic, but silos themselves were at times beneficial to partnerships. This revealed a mismatch between rhetoric and a realistic understanding of what components of the programme were functional and which were more hindrance than help. There were high expectations placed on the concept of

Relativistic electron beams above thunderclouds

DEFF Research Database (Denmark)

Füellekrug, M.; Roussel-Dupre, R.; Symbalisty, E. M. D.

2011-01-01

Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency similar to 40-400 kHz which they radiate. The electron beams occur similar to 2-9 ms after positive cloud-to-ground lightning discharges at heights between similar to 22-72 km above...... thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron beam. One electron beam was detected without any luminous sprite which suggests that electron beams may also occur independently of sprites. Numerical simulations show that beams...... of electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of similar to 7MeV to transport a total charge of similar to-10mC upwards. The impulsive current similar to 3 x 10(-3) Am-2 associated with relativistic electron beams above thunderclouds...

The cryogenic installations for irradiation in the reactors Melusine and Siloe; Les installations cryogeniques pour irradiations des reacteurs Melusine et Siloe

Energy Technology Data Exchange (ETDEWEB)

Bochirol, L; Le Calvez, J; Doulat, J; Verdier, J; Lacaze, A; Weil, L [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

The study of defects created in solids by irradiation is of considerable fundamental and practical interest. Low temperature irradiation allows defects to be obtained in their simplest 'primary' state, not being then annihilated or rearranged by thermal motion. In-pile irradiation at low temperature raises a number of technical problems connected to 1) the necessary refrigeration power which may be considerable, 2) chemical processes which may occur under irradiation, 3) the lack of space in a reactor. Furthermore the necessity that all the irradiation and subsequent measurements be done without reheating the samples demands continuous and reliable working of the irradiation device and its being designed so as to permit removal of the samples in the cold condition or their measurement and controlled annealing 'in situ'. The way in which these problems have been solved in Grenoble for irradiation devices at 78 deg. K, 28 deg. K and 4 deg. K in the swimming-pool reactors Melusine and Siloe is described. Some operation results are given about the liquid nitrogen rig, called mark A, which has worked for several years in Melusine. In particular certain observations about chemical reactions which may occur in impure liquid nitrogen under radiation are made. The liquid nitrogen rig, called mark B, which has just been installed in the Siloe reactor, is described with some detail. The essential features of this apparatus are that irradiation can be performed in higher fluxes with it than with the former one, and that its operation is made much easier by a design which allows the samples to be introduced and removed without any disconnection of the apparatus. A liquid hydrogen loop, which has worked for one year in the Melusine reactor, is then analysed. An entirely closed hydrogen refrigerating circuit provides the coldness to the irradiation enclosure, which contains neon. Owing to this solution, the samples may be recovered in the cold condition without hydrogen being

Modelling above Ground Biomass of Mangrove Forest Using SENTINEL-1 Imagery

Science.gov (United States)

Labadisos Argamosa, Reginald Jay; Conferido Blanco, Ariel; Balidoy Baloloy, Alvin; Gumbao Candido, Christian; Lovern Caboboy Dumalag, John Bart; Carandang Dimapilis, Lee, , Lady; Camero Paringit, Enrico

2018-04-01

Many studies have been conducted in the estimation of forest above ground biomass (AGB) using features from synthetic aperture radar (SAR). Specifically, L-band ALOS/PALSAR (wavelength 23 cm) data is often used. However, few studies have been made on the use of shorter wavelengths (e.g., C-band, 3.75 cm to 7.5 cm) for forest mapping especially in tropical forests since higher attenuation is observed for volumetric objects where energy propagated is absorbed. This study aims to model AGB estimates of mangrove forest using information derived from Sentinel-1 C-band SAR data. Combinations of polarisations (VV, VH), its derivatives, grey level co-occurrence matrix (GLCM), and its principal components were used as features for modelling AGB. Five models were tested with varying combinations of features; a) sigma nought polarisations and its derivatives; b) GLCM textures; c) the first five principal components; d) combination of models a-c; and e) the identified important features by Random Forest variable importance algorithm. Random Forest was used as regressor to compute for the AGB estimates to avoid over fitting caused by the introduction of too many features in the model. Model e obtained the highest r2 of 0.79 and an RMSE of 0.44 Mg using only four features, namely, σ°VH GLCM variance, σ°VH GLCM contrast, PC1, and PC2. This study shows that Sentinel-1 C-band SAR data could be used to produce acceptable AGB estimates in mangrove forest to compensate for the unavailability of longer wavelength SAR.

Experiences in the emptying of waste silos containing solid nuclear waste from graphite- moderated reactors

International Nuclear Information System (INIS)

Wall, S.; Schwarz, T.

2003-01-01

Before reactor sites can be handed over for ultimate decommissioning, at some sites silos containing waste from operations need to be emptied. The form and physical condition of the waste demands sophisticated retrieval technologies taking into account the onsite situation in terms of infrastructure and silo geometry. Furthermore, in the case of graphite moderated reactors, this waste usually includes several tonnes of graphite waste requiring special HVAC and dust handling measures. RWE NUKEM Group has already performed several contracts dealing with such emptying tasks. Of particular interest for the upcoming decommissioning projects in France might be the activities at Vandellos, Spain and Trawsfynnyd, UK. Retrieval System for Vandellos NPP is discussed. Following an international competitive tender exercise, RWE NUKEM won the contract to provide a turn-key retrieval system. This involved the design, manufacture and installation of a system built around the modules of a 200 kg capacity version of the ARTISAN manipulator system. The ARTISAN 200 manipulator, with remote slave arm detach facility, was deployed on a telescopic mast inserted into the silos through the roof penetrations. The manipulator deployed a range of tools to gather the waste and load it into a transfer basket, deployed through an adjacent penetration. After commissioning, the system cleared the vaults in less than the scheduled period with no failures. At the Trawsfynnyd Magnox plants two types of intermediate level waste (ILW) accumulated on site; namely Miscellaneous Activated Components (MAC) and Fuel Element Debris (FED). MAC is predominantly components that have been activated by the reactor core and then discharged. FED mainly consists of fuel cladding produced when fuel elements were prepared for dispatch to the reprocessing facility. RWE NUKEM Ltd. was awarded a contract to design, supply, commission and operate equipment to retrieve, pack and immobilize the two waste streams. Major

Changes in ground beetle assemblages above and below the treeline of the Dolomites after almost 30 years (1980/2009).

Science.gov (United States)

Pizzolotto, Roberto; Gobbi, Mauro; Brandmayr, Pietro

2014-04-01

Very little is known about the changes of ground beetle assemblages in the last few decades in the Alps, and different responses to climate change of animal populations living above and below the treeline have not been estimated yet. This study focuses on an altitudinal habitat sequence from subalpine spruce forest to alpine grassland in a low disturbance area of the southeastern Dolomites in Italy, the Paneveggio Regional Park. We compared the ground beetle (Carabidae) populations sampled in 1980 in six stands below and above the treeline (1650-2250 m a.s.l.) with those sampled in the same sites almost 30 years later (2008/9). Quantitative data (species richness and abundance) have been compared by means of several diversity indexes and with a new index, the Index of Rank-abundance Change (IRC). Our work shows that species richness and abundance have changed after almost 30 years as a consequence of local extinctions, uphill increment of abundance and uphill shift of distribution range. The overall species number dropped from 36 to 27, while in the sites above the treeline, species richness and abundance changed more than in the forest sites. Two microtherm characteristic species of the pioneer cushion grass mats, Nebria germari and Trechus dolomitanus, became extinct or showed strong abundance reduction. In Nardetum pastures, several hygrophilic species disappeared, and xerophilic zoophytophagous elements raised their population density. In forest ecosystems, the precipitation reduction caused deep soil texture and watering changes, driving a transformation from Sphagnum-rich (peaty) to humus-rich soil, and as a consequence, soil invertebrate biomass strongly increased and thermophilic carabids enriched the species structure. In three decades, Carabid assemblages changed consistently with the hypothesis that climate change is one of the main factors triggering natural environment modifications. Furthermore, the level of human disturbance could enhance the

Electroluminescence from completely horizontally oriented dye molecules

Energy Technology Data Exchange (ETDEWEB)

Komino, Takeshi [Education Center for Global Leaders in Molecular System for Devices, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Japan Science and Technology Agency, ERATO, Adachi Molecular Exciton Engineering Project, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Sagara, Yuta [Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Tanaka, Hiroyuki [Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Oki, Yuji [Japan Science and Technology Agency, ERATO, Adachi Molecular Exciton Engineering Project, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Department of Electronics, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Nakamura, Nozomi [Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Fujimoto, Hiroshi [Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Fukuoka i" 3-Center for Organic Photonics and Electronics Research (i3-OPERA), Fukuoka 819-0388 (Japan); and others

2016-06-13

A complete horizontal molecular orientation of a linear-shaped thermally activated delayed fluorescent guest emitter 2,6-bis(4-(10Hphenoxazin-10-yl)phenyl)benzo[1,2-d:5,4-d′] bis(oxazole) (cis-BOX2) was obtained in a glassy host matrix by vapor deposition. The orientational order of cis-BOX2 depended on the combination of deposition temperature and the type of host matrix. Complete horizontal orientation was obtained when a thin film with cis-BOX2 doped in a 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP) host matrix was fabricated at 200 K. The ultimate orientation of guest molecules originates from not only the kinetic relaxation but also the kinetic stability of the deposited guest molecules on the film surface during film growth. Utilizing the ultimate orientation, a highly efficient organic light-emitting diode with the external quantum efficiency of 33.4 ± 2.0% was realized. The thermal stability of the horizontal orientation of cis-BOX2 was governed by the glass transition temperature (T{sub g}) of the CBP host matrix; the horizontal orientation was stable unless the film was annealed above T{sub g}.

Exploring the Impact of Silos in Achieving Brand Orientation

DEFF Research Database (Denmark)

Gyrd-Jones, Richard; Helm, Clive; Munk, Jonas

silos are associated with different mindsets that create barriers to the achievement of brand orientation. The case follows a medium sized manufacturing company in its efforts to introduce a brand revitalization strategy across the organization. Despite the strategy having top management full support......Brands are widely recognised as important sources of competitive advantage. The newly emerged concept of brand orientation has be used to assess the extent to which the whole organisation is orientated around the brand and thus the extent to which organisational resources are focused around...... maximising brand potential. Whilst offering potential to improve our understanding of how brands can be effectively managed and offering practitioners a set of tool to this end, this concept is limited in both its empirical and theoretical foundations. Through a case study this paper documents how functional...

Estimation of crown biomass of Pinus pinaster stands and shrubland above-ground biomass using forest inventory data, remotely sensed imagery and spatial prediction models

Science.gov (United States)

H. Viana; J. Aranha; D. Lopes; Warren B. Cohen

2012-01-01

Spatially crown biomass of Pinus pinaster stands and shrubland above-ground biomass (AGB) estimation was carried-out in a region located in Centre-North Portugal, by means of different approaches including forest inventory data, remotely sensed imagery and spatial prediction models. Two cover types (pine stands and shrubland) were inventoried and...

New Perspectives on the “Silo Effect”: Initial Comparisons of Network Structures Across Public Health Collaboratives

Science.gov (United States)

H. Retrum, Jessica; M. Varda, Danielle

2015-01-01

Objectives. We explored to what extent “silos” (preferential partnering) persist in interorganizational boundaries despite advances in working across boundaries. We focused on organizational homophily and resulting silo effects within networks that might both facilitate and impede success in public health collaboratives (PHCs). Methods. We analyzed data from 162 PHCs with a series of exponential random graph models to determine the influence of uniform and differential homophily among organizations and to identify the propensity for partnerships with similar organizations. Results. The results demonstrated a low presence (8%) of uniform homophily among networks, whereas a greater number (30%) of PHCs contained varying levels of differential homophily by 1 or more types of organization. We noted that the higher frequency among law enforcement, nonprofits, and public health organizations demonstrated a partner preference with similar organizations. Conclusions. Although we identified only a modest occurrence of partner preference in PHCs, overall success in efforts to work across boundaries might be problematic when public health members (often leaders of PHCs) exhibit the tendency to form silos. PMID:25689195

Ultraviolet-B Radiation and Nitrogen Affect Nutrient Concentrations and the Amount of Nutrients Acquired by Above-Ground Organs of Maize

OpenAIRE

Correia, Carlos M.; Coutinho, João F.; Bacelar, Eunice A.; Gonçalves, Berta M.; Björn, Lars Olof; Moutinho Pereira, José

2012-01-01

UV-B radiation effects on nutrient concentrations in above-ground organs of maize were investigated at silking and maturity at different levels of applied nitrogen under field conditions. The experiment simulated a 20% stratospheric ozone depletion over Portugal. At silking, UV-B increased N, K, Ca, and Zn concentrations, whereas at maturity Ca, Mg, Zn, and Cu increased and N, P and Mn decreased in some plant organs. Generally, at maturity, N, Ca, Cu, and Mn were lower, while P, K, and Zn con...

Radiation transport in earth for neutron and gamma ray point sources above an air-ground interface

International Nuclear Information System (INIS)

Lillie, R.A.; Santoro, R.T.

1979-03-01

Two-dimensional discrete ordinates methods were used to calculate the instantaneous dose rate in silicon and neutron and gamma ray fluences as a function of depth in earth from point sources at various heights (1.0, 61.3, and 731.5 meters) above an air--ground interface. The radiation incident on the earth's surface was transported through an earth-only and an earth--concrete model containing 0.9 meters of borated concrete beginning 0.5 meters below the earth's surface to obtain fluence distributions to a depth of 3.0 meters. The inclusion of borated concrete did not significantly reduce the total instantaneous dose rate in silicon and, in all cases, the secondary gamma ray fluence and corresponding dose are substantially larger than the primary neutron fluence and corresponding dose for depths greater than 0.6 meter. 4 figures, 4 tables

Radiation transport in earth for neutron and gamma-ray point sources above an air-ground interface

International Nuclear Information System (INIS)

Lillie, R.A.; Santoro, R.T.

1980-01-01

Two-dimensional discrete-ordinates methods have been used to calculate the instantaneous dose rate in silicon and neutron and gamma-ray fluences as a function of depth in earth from point sources at various heights (1.0, 61.3, and 731.5 m) above an air-ground interface. The radiation incident on the earth's surface was transported through an earth-only and an earth-concrete model containing 0.9 m of borated concrete beginning 0.5 m below the earth's surface to obtain fluence distributions to a depth of 3.0 m. The inclusion of borated concrete did not significantly reduce the total instantaneous dose rate in silicon, and in all cases, the secondary gamma-ray fluence and corresponding dose are substantially larger than the primary neutron fluence and corresponding dose for depths > 0.6 m

Estimation and mapping of above-ground biomass of mangrove forests and their replacement land uses in the Philippines using Sentinel imagery

Science.gov (United States)

Castillo, Jose Alan A.; Apan, Armando A.; Maraseni, Tek N.; Salmo, Severino G.

2017-12-01

The recent launch of the Sentinel-1 (SAR) and Sentinel-2 (multispectral) missions offers a new opportunity for land-based biomass mapping and monitoring especially in the tropics where deforestation is highest. Yet, unlike in agriculture and inland land uses, the use of Sentinel imagery has not been evaluated for biomass retrieval in mangrove forest and the non-forest land uses that replaced mangroves. In this study, we evaluated the ability of Sentinel imagery for the retrieval and predictive mapping of above-ground biomass of mangroves and their replacement land uses. We used Sentinel SAR and multispectral imagery to develop biomass prediction models through the conventional linear regression and novel Machine Learning algorithms. We developed models each from SAR raw polarisation backscatter data, multispectral bands, vegetation indices, and canopy biophysical variables. The results show that the model based on biophysical variable Leaf Area Index (LAI) derived from Sentinel-2 was more accurate in predicting the overall above-ground biomass. In contrast, the model which utilised optical bands had the lowest accuracy. However, the SAR-based model was more accurate in predicting the biomass in the usually deficient to low vegetation cover non-forest replacement land uses such as abandoned aquaculture pond, cleared mangrove and abandoned salt pond. These models had 0.82-0.83 correlation/agreement of observed and predicted value, and root mean square error of 27.8-28.5 Mg ha-1. Among the Sentinel-2 multispectral bands, the red and red edge bands (bands 4, 5 and 7), combined with elevation data, were the best variable set combination for biomass prediction. The red edge-based Inverted Red-Edge Chlorophyll Index had the highest prediction accuracy among the vegetation indices. Overall, Sentinel-1 SAR and Sentinel-2 multispectral imagery can provide satisfactory results in the retrieval and predictive mapping of the above-ground biomass of mangroves and the replacement

Control program of the neutron four-circle-diffractometer P32 at the SILOE reactor/CEN Grenoble

International Nuclear Information System (INIS)

Guth, H.; Paulus, H.; Reimers, W.; Heger, G.

1983-09-01

The four-circle diffractometer P32 for elastic neutron scattering on single crystals was installed at the SILOE reactor/CEN Grenoble in 1981. The control program, presented here, is a new update of the former program versions used at the FR2 reactor/Kernforschungszentrum Karlsruhe. Important improvements concerning reliability and handling of the diffractometer are added. (orig.) [de

Above-ground woody carbon sequestration measured from tree rings is coherent with net ecosystem productivity at five eddy-covariance sites.

Science.gov (United States)

Babst, Flurin; Bouriaud, Olivier; Papale, Dario; Gielen, Bert; Janssens, Ivan A; Nikinmaa, Eero; Ibrom, Andreas; Wu, Jian; Bernhofer, Christian; Köstner, Barbara; Grünwald, Thomas; Seufert, Günther; Ciais, Philippe; Frank, David

2014-03-01

• Attempts to combine biometric and eddy-covariance (EC) quantifications of carbon allocation to different storage pools in forests have been inconsistent and variably successful in the past. • We assessed above-ground biomass changes at five long-term EC forest stations based on tree-ring width and wood density measurements, together with multiple allometric models. Measurements were validated with site-specific biomass estimates and compared with the sum of monthly CO₂ fluxes between 1997 and 2009. • Biometric measurements and seasonal net ecosystem productivity (NEP) proved largely compatible and suggested that carbon sequestered between January and July is mainly used for volume increase, whereas that taken up between August and September supports a combination of cell wall thickening and storage. The inter-annual variability in above-ground woody carbon uptake was significantly linked with wood production at the sites, ranging between 110 and 370 g C m(-2) yr(-1) , thereby accounting for 10-25% of gross primary productivity (GPP), 15-32% of terrestrial ecosystem respiration (TER) and 25-80% of NEP. • The observed seasonal partitioning of carbon used to support different wood formation processes refines our knowledge on the dynamics and magnitude of carbon allocation in forests across the major European climatic zones. It may thus contribute, for example, to improved vegetation model parameterization and provides an enhanced framework to link tree-ring parameters with EC measurements. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Below and above-ground carbon distribution along a rainfall gradient. A case of the Zambezi teak forests, Zambia

Science.gov (United States)

Ngoma, Justine; Moors, Eddy; Kruijt, Bart; Speer, James H.; Vinya, Royd; Chidumayo, Emmanuel N.; Leemans, Rik

2018-02-01

Understanding carbon (C) stocks or biomass in forests is important to examine how forests mitigate climate change. To estimate biomass in stems, branches and roots takes intensive fieldwork to uproot, cut and weigh the mass of each component. Different models or equations are also required. Our research focussed on the dry tropical Zambezi teak forests and we studied their structure at three sites following a rainfall gradient in Zambia. We sampled 3558 trees at 42 plots covering a combined area of 15ha. Using data from destructive tree samples, we developed mixed-species biomass models to estimate above ground biomass for small (forests, thereby adversely affecting their mitigating role in climate change.

Alterações químicas e microbiológicas nas silagens de capim-Tifton 85 após a abertura dos silos Chemical and microbiological changes of Tifton 85 grass silage after silos opening

Directory of Open Access Journals (Sweden)

Rúben Pablo Schocken-Iturrino

2005-04-01

Full Text Available O trabalho foi conduzido para avaliação da presença de Listeria sp. e de fungos nas silagens de capim-Tifton 85 sem emurchecimento, com emurchecimento por uma e duas horas e sem emurchecimento com adição ou não de polpa cítrica (5,0% do peso verde. As amostragens foram efetuadas no momento da abertura do silo (80 dias da ensilagem, aos 15 e 30 dias após exposição ao ar, para avaliar os teores de matéria seca (MS, as alterações químicas (pH, N amoniacal, ácidos orgânicos e a ocorrência de Listeria sp. e de fungos. Os dados foram analisados segundo o delineamento em blocos casualizados, em esquema de parcelas subdivididas (nas parcelas foram avaliadas as silagens submetidas aos tratamentos e nas subparcelas, os períodos de exposição ao ar, com quatro repetições. Observaram-se baixos teores de ácidos orgânicos e de N amoniacal decorrentes dos altos valores de MS, o que acarretou baixa formação de produtos fermentados e elevação do pH. A presença de Listeria sp. foi observada em 65,6% das amostras no momento da abertura dos silos e, destas, 10% foram positivas para Listeria monocytogenes. As silagens apresentaram baixa estabilidade aeróbia, tendo sido registrado aumento na ocorrência dos fungos Penicillium, Fusarium e Pithomyces com o prolongamento do período de exposição ao ar.The experiment was carried out to evaluate the fermentation characteristics, Listeria sp. and molds occurrence on Tifton 85 silage no wilted, wilted for one and two hours and no wilted with or without citrus pulp (5.0 % of fresh forage. The samplings were taken at the opening of the silos (80 days after ensiling, 15, and 30 days after air exposition to evaluated dry matter (DM content, chemical changes (pH, ammonia N, organic acids and Listeria sp., and molds occurrence. Data were analyzed according to a randomized block design in split plot scheme, considering the silage on the plots, and periods of air exposure on the split plot, with four

Landsat Imagery-Based Above Ground Biomass Estimation and Change Investigation Related to Human Activities

Directory of Open Access Journals (Sweden)

Chaofan Wu

2016-02-01

Full Text Available Forest biomass is a significant indicator for substance accumulation and forest succession, and a spatiotemporal biomass map would provide valuable information for forest management and scientific planning. In this study, Landsat imagery and field data cooperated with a random forest regression approach were used to estimate spatiotemporal Above Ground Biomass (AGB in Fuyang County, Zhejiang Province of East China. As a result, the AGB retrieval showed an increasing trend for the past decade, from 74.24 ton/ha in 2004 to 99.63 ton/ha in 2013. Topography and forest management were investigated to find their relationships with the spatial distribution change of biomass. In general, the simulated AGB increases with higher elevation, especially in the range of 80–200 m, wherein AGB acquires the highest increase rate. Moreover, the forest policy of ecological forest has a positive effect on the AGB increase, particularly within the national level ecological forest. The result in this study demonstrates that human activities have a great impact on biomass distribution and change tendency. Furthermore, Landsat image-based biomass estimates would provide illuminating information for forest policy-making and sustainable development.

Remediation and recycling of oil-contaminated soil beneath a large above-ground storage tank

International Nuclear Information System (INIS)

Wallace, G.

1994-01-01

While retrofitting a large 30-year-old, above-ground petroleum storage tank, Southern California Edison Company (SCE) discovered that soil beneath the fixed-roof, single-bottom tank was contaminated with 40,000 gallons of number-sign 6 fuel oil. The steel tank was left in place during the excavation and remediation of the contaminated soil to retain the operating permit. The resulting 2,000 tons of contaminated aggregate was recycled to make asphalt concrete for paving the tank basin and the remaining 5,600 tons of oily soil was thermally treated on site for use as engineered fill at another location. This successful operation provided an economical cleanup solution for a common leakage problem of single-lined tanks and eliminated the long-term liability of Class 1 landfill disposal. As a pro-active environmental effort, this paper shares SCE's site assessment procedure, reveals the engineering method developed to stabilize the tank, discusses the soil treatment technologies used, describes the problems encountered and lessons learned during the cleanup, discloses the costs of the operation, and offers guidelines and recommendations for similar tank remediation. This paper does not describe the work or costs for removing or replacing the tank bottom

Silo busting: how to execute on the promise of customer focus.

Science.gov (United States)

Gulati, Ranjay

2007-05-01

For many senior executives, shifting from selling products to selling solutions--packages of products and services--is a priority in today's increasingly commoditized markets. Companies, however, aren't always structured to make that shift. Knowledge and expertise often reside in silos, and many companies have trouble harnessing their resources across those boundaries in a way that customers value and are willing to pay for. Some companies--like GE Healthcare, Best Buy, and commercial real estate provider Jones Lang LaSalle (JLL)--have restructured themselves around customer needs to deliver true solutions. They did so by engaging in four sets of activities: COORDINATION: To deliver customer-focused solutions, three things must occur easily across boundaries: information sharing, division of labor, and decision making. Sometimes this involves replacing traditional silos with customer-focused ones, but more often it entails transcending existing boundaries. JLL has experimented with both approaches. COOPERATION: Customer-centric companies, such as Cisco Systems, develop metrics for customer satisfaction and incentives that reward customer-focused cooperation. Most also shake up the power structure so that people who are closest to customers have the authority to act on their behalf. CAPABILITY: Delivering customer-focused solutions requires some employees to be generalists instead of specialists. They need experience with more than one product or service, a deep knowledge of customer needs, and the ability to traverse internal boundaries. CONNECTION: By combining their offerings with those of a partner, companies can cut costs even as they create higher-value solutions, as Starbucks has found through its diverse partnerships. To stand out in a commoditized market, companies must understand what customers value. Ultimately, some customers may be better off purchasing products and services piecemeal.

The 'SILOE' reactor at Grenoble, France and associated hot cell facilities. Information sheets

International Nuclear Information System (INIS)

Hardt, P. von der; Roettger, H.

1981-01-01

Technical information is given on the SILOE reactor and associated hot cell facilities, with the main emphasis on experimental irradiation facilities, specialized irradiation devices (loops and capsules) and possibilities for post-irradiation examinations of samples. The information is presented in the form of eight information sheets under the headings: main characteristics of the reactor; utilization and specialization of the reactor; experimental facilities; neutron spectra; main characteristics of specialized irradiation devices; main characteristics of hot cell facilities; equipment and techniques available for post-irradiation examinations; utilization and specialization of the hot cell facilities

Cathodic protection simulation of above ground storage tank bottom: Experimental and numerical results

Energy Technology Data Exchange (ETDEWEB)

Schultz, Marcelo [Inspection Department, Rio de Janeiro Refinery - REDUC, Petrobras, Rio de Janeiro (Brazil); Brasil, Simone L.D.C. [Chemistry School, Federal University of Rio de Janeiro, UFRJ, Rio de Janeiro (Brazil); Baptista, Walmar [Corrosion Department, Research Centre - CENPES, Petrobras (Brazil); Miranda, Luiz de [Materials and Metallurgical Engineering Program, COPPE, UFRJ, Rio de Janeiro (Brazil); Brito, Rosane F. [Corrosion Department, Research Centre, CENPES, Petrobras, Rio de Janeiro (Brazil)

2004-07-01

The deterioration history of Above ground Storage Tanks (AST) of Petrobras' refineries - shows that the great incidence of corrosion in the AST bottom is at the external side. This is a problem in the disposability of storage crude oil and other final products. At this refinery, all AST's are built over a concrete base with a lot of pile to support the structure and distribute the charge homogeneously. Because of this it is very difficult to use cathodic protection as an anti-corrosive method for each one of these tanks. This work presents an alternative cathodic protection system to protect the external side of the tank bottom using a new metallic bottom, placed at different distance from the original one. The space between the two bottoms was filled with one of two kinds of soils, sand or clay, more conductive than the concrete. Using a prototype tank it was studied the potential distributions over the new tank bottom for different system parameters, as soil resistivity, number and position of anodes localized in the old bottom. These experimental results were compared to numerical simulations, carried out using a software based on the Boundary Element Method. The computer simulation validates this protection method, confirming to be a very useful tool to define the optimized cathodic protection system configuration. (authors)

A comparative analysis of extended water cloud model and backscatter modelling for above-ground biomass assessment in Corbett Tiger Reserve

Science.gov (United States)

Kumar, Yogesh; Singh, Sarnam; Chatterjee, R. S.; Trivedi, Mukul

2016-04-01

Forest biomass acts as a backbone in regulating the climate by storing carbon within itself. Thus the assessment of forest biomass is crucial in understanding the dynamics of the environment. Traditionally the destructive methods were adopted for the assessment of biomass which were further advanced to the non-destructive methods. The allometric equations developed by destructive methods were further used in non-destructive methods for the assessment, but they were mostly applied for woody/commercial timber species. However now days Remote Sensing data are primarily used for the biomass geospatial pattern assessment. The Optical Remote Sensing data (Landsat8, LISS III, etc.) are being used very successfully for the estimation of above ground biomass (AGB). However optical data is not suitable for all atmospheric/environmental conditions, because it can't penetrate through clouds and haze. Thus Radar data is one of the alternate possible ways to acquire data in all-weather conditions irrespective of weather and light. The paper examines the potential of ALOS PALSAR L-band dual polarisation data for the estimation of AGB in the Corbett Tiger Reserve (CTR) covering an area of 889 km2. The main focus of this study is to explore the accuracy of Polarimetric Scattering Model (Extended Water Cloud Model (EWCM) with respect to Backscatter model in the assessment of AGB. The parameters of the EWCM were estimated using the decomposition components (Raney Decomposition) and the plot level information. The above ground biomass in the CTR ranges from 9.6 t/ha to 322.6 t/ha.

Modelling Growth and Partitioning of Annual Above-Ground Vegetative and Reproductive Biomass of Grapevine

Science.gov (United States)

Meggio, Franco; Vendrame, Nadia; Maniero, Giovanni; Pitacco, Andrea

2014-05-01

In the current climate change scenarios, both agriculture and forestry inherently may act as carbon sinks and consequently can play a key role in limiting global warming. An urgent need exists to understand which land uses and land resource types have the greatest potential to mitigate greenhouse gas (GHG) emissions contributing to global change. A common believe is that agricultural fields cannot be net carbon sinks due to many technical inputs and repeated disturbances of upper soil layers that all contribute to a substantial loss both of the old and newly-synthesized organic matter. Perennial tree crops (vineyards and orchards), however, can behave differently: they grow a permanent woody structure, stand undisturbed in the same field for decades, originate a woody pruning debris, and are often grass-covered. In this context, reliable methods for quantifying and modelling emissions and carbon sequestration are required. Carbon stock changes are calculated by multiplying the difference in oven dry weight of biomass increments and losses with the appropriate carbon fraction. These data are relatively scant, and more information is needed on vineyard management practices and how they impact vineyard C sequestration and GHG emissions in order to generate an accurate vineyard GHG footprint. During the last decades, research efforts have been made for estimating the vineyard carbon budget and its allocation pattern since it is crucial to better understand how grapevines control the distribution of acquired resources in response to variation in environmental growth conditions and agronomic practices. The objective of the present study was to model and compare the dynamics of current year's above-ground biomass among four grapevine varieties. Trials were carried out over three growing seasons in field conditions. The non-linear extra-sums-of-squares method demonstrated to be a feasible way of growth models comparison to statistically assess significant differences among

Calculation of dose distribution above contaminated soil

Science.gov (United States)

Kuroda, Junya; Tenzou, Hideki; Manabe, Seiya; Iwakura, Yukiko

2017-07-01

The purpose of this study was to assess the relationship between altitude and the distribution of the ambient dose rate in the air over soil decontamination area by using PHITS simulation code. The geometry configuration was 1000 m ×1000 m area and 1m in soil depth and 100m in altitude from the ground to simulate the area of residences or a school grounds. The contaminated region is supposed to be uniformly contaminated by Cs-137 γ radiation sources. The air dose distribution and space resolution was evaluated for flux of the gamma rays at each altitude, 1, 5, 10, and 20m. The effect of decontamination was calculated by defining sharpness S. S was the ratio of an average flux and a flux at the center of denomination area in each altitude. The suitable flight altitude of the drone is found to be less than 15m above a residence and 31m above a school grounds to confirm the decontamination effect. The calculation results can be a help to determine a flight planning of a drone to minimize the clash risk.

Trampoline effect in extreme ground motion.

Science.gov (United States)

Aoi, Shin; Kunugi, Takashi; Fujiwara, Hiroyuki

2008-10-31

In earthquake hazard assessment studies, the focus is usually on horizontal ground motion. However, records from the 14 June 2008 Iwate-Miyagi earthquake in Japan, a crustal event with a moment magnitude of 6.9, revealed an unprecedented vertical surface acceleration of nearly four times gravity, more than twice its horizontal counterpart. The vertical acceleration was distinctly asymmetric; the waveform envelope was about 1.6 times as large in the upward direction as in the downward direction, which is not explained by existing models of the soil response. We present a simple model of a mass bouncing on a trampoline to account for this asymmetry and the large vertical amplitude. The finding of a hitherto-unknown mode of strong ground motion may prompt major progress in near-source shaking assessments.

Hovering performance of Anna's hummingbirds (Calypte anna) in ground effect.

Science.gov (United States)

Kim, Erica J; Wolf, Marta; Ortega-Jimenez, Victor Manuel; Cheng, Stanley H; Dudley, Robert

2014-09-06

Aerodynamic performance and energetic savings for flight in ground effect are theoretically maximized during hovering, but have never been directly measured for flying animals. We evaluated flight kinematics, metabolic rates and induced flow velocities for Anna's hummingbirds hovering at heights (relative to wing length R = 5.5 cm) of 0.7R, 0.9R, 1.1R, 1.7R, 2.2R and 8R above a solid surface. Flight at heights less than or equal to 1.1R resulted in significant reductions in the body angle, tail angle, anatomical stroke plane angle, wake-induced velocity, and mechanical and metabolic power expenditures when compared with flight at the control height of 8R. By contrast, stroke plane angle relative to horizontal, wingbeat amplitude and wingbeat frequency were unexpectedly independent of height from ground. Qualitative smoke visualizations suggest that each wing generates a vortex ring during both down- and upstroke. These rings expand upon reaching the ground and present a complex turbulent interaction below the bird's body. Nonetheless, hovering near surfaces results in substantial energetic benefits for hummingbirds, and by inference for all volant taxa that either feed at flowers or otherwise fly close to plant or other surfaces. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Above- and Belowground Biomass Allocation in Shrub Biomes across the Northeast Tibetan Plateau

Science.gov (United States)

Yang, Yuanhe; Yang, Lucun; Zhou, Guoying

2016-01-01

Biomass partitioning has been explored across various biomes. However, the strategies of allocation in plants still remain contentious. This study investigated allocation patterns of above- and belowground biomass at the community level, using biomass survey from the Tibetan Plateau. We explored above- and belowground biomass by conducting three consecutive sampling campaigns across shrub biomes on the northeast Tibetan Plateau during 2011–2013. We then documented the above-ground biomass (AGB), below-ground biomass (BGB) and root: shoot ratio (R/S) and the relationships between R/S and environment factors using data from 201 plots surveyed from 67 sites. We further examined relationships between above-ground and below-ground biomass across various shrub types. Our results indicated that the median values of AGB, BGB, and R/S in Tibetan shrub were 1102.55, 874.91 g m-2, and 0.85, respectively. R/S showed significant trend with mean annual precipitation (MAP), while decreased with mean annual temperature (MAT). Reduced major axis analysis indicated that the slope of the log-log relationship between above- and belowground biomass revealed a significant difference from 1.0 over space, supporting the optimal hypothesis. Interestingly, the slopes of the allometric relationship between log AGB and log BGB differed significantly between alpine and desert shrub. Our findings supported the optimal theory of above- and belowground biomass partitioning in Tibetan shrub, while the isometric hypothesis for alpine shrub at the community level. PMID:27119379

Estimating above-ground biomass on mountain meadows and pastures through remote sensing

Science.gov (United States)

Barrachina, M.; Cristóbal, J.; Tulla, A. F.

2015-06-01

Extensive stock-breeding systems developed in mountain areas like the Pyrenees are crucial for local farming economies and depend largely on above-ground biomass (AGB) in the form of grass produced on meadows and pastureland. In this study, a multiple linear regression analysis technique based on in-situ biomass collection and vegetation and wetness indices derived from Landsat-5 TM data is successfully applied in a mountainous Pyrenees area to model AGB. Temporal thoroughness of the data is ensured by using a large series of images. Results of on-site AGB collection show the importance for AGB models to capture the high interannual and intraseasonal variability that results from both meteorological conditions and farming practices. AGB models yield best results at midsummer and end of summer before mowing operations by farmers, with a mean R2, RMSE and PE for 2008 and 2009 midsummer of 0.76, 95 g m-2 and 27%, respectively; and with a mean R2, RMSE and PE for 2008 and 2009 end of summer of 0.74, 128 g m-2 and 36%, respectively. Although vegetation indices are a priori more related with biomass production, wetness indices play an important role in modeling AGB, being statistically selected more frequently (more than 50%) than other traditional vegetation indexes (around 27%) such as NDVI. This suggests that middle infrared bands are crucial descriptors of AGB. The methodology applied in this work compares favorably with other works in the literature, yielding better results than those works in mountain areas, owing to the ability of the proposed methodology to capture natural and anthropogenic variations in AGB which are the key to increasing AGB modeling accuracy.

An engineering geological investigation of ground subsidence above the Huntly East Mine

Energy Technology Data Exchange (ETDEWEB)

Kelsey, P.I.

1987-10-01

Ground subsidence above the Huntly East Mine at the N.Z.E.D. Hostel has affected an area of approximately seven hectares with measured settlements of over 800mm. Extensive damage was suffered by most buildings and services of the hostel complex To determine the cause(s) and mechanism(s) of the subsidence, site and laboratory investigations were undertaken. Site investigations included core and wash drilling, geophysical borehole logging, dutch cone penetrometer soundings plus piezometer installation and monitoring. Laboratory investigations included one dimensional consolidation and permeability testing, SEM fabric studies, XRD and chemical tests for clay mineralogy, and determinations of Atterberg Limits and grain size distributions. The mine overburden geology at the site consists of a 35 to 60m thick sequence of mudstones and coal seams of the Te Kuiti Group (Eocene to Oligocene), and overlain by a 50 to 70m thick succession of saturated sands, silts and gravels of the Tauranga Group (Pliocene to Holocene). Within the Tauranga Group three aquifers are present. The engineering geological model considered most likely to explain the subsidence is mine roof collapse causing void migration to near the top of the Te Kuiti Group sequence resulting in drainage and depressurising of aquifers at the base of the Tauranga Group. Aquifer depressurisation is considered likely to cause consolidation within both the aquifer and aquitards associated with it. Back-analyses of the dewatering consolidation model in terms of both magnitude and rates of settlement are consistent with observed values. A finite difference numerical analysis was developed for estimations of settlement rates. 98 refs., 67 figs., 12 tabs.

Dismantling the Justice Silos: avoiding the pitfalls and reaping the benefits of information-sharing between forensic science, medicine and law.

Science.gov (United States)

Kelty, Sally F; Julian, Roberta; Ross, Alastair

2013-07-10

Forensic science is increasingly relied on by police and the courts to exonerate the innocent and to establish links to crime. With this increased reliance the potential for unjust outcomes increases, especially in serious matters for two reasons. The more serious the matter, the more likely that evidence mishandling can lead to wrongful imprisonment, and the more likely the personnel involved will be multi-disciplinary (police, medicine, law, forensic science), and multi-organisational (Health, Justice, private legal/medical, police). The importance of identifying effective multi-organisational interactions was highlighted in the recent wrongful imprisonment of an Australian male for a sexual assault he did not commit. One factor that led to this unjust outcome was the justice silo effect: where forensic practitioners from different agencies operate in isolation (rarely communicating or sharing information/knowledge). In this paper we discuss findings from the Interfaces Project designed to assess the extent of the justice silos within Australia. We interviewed 103 police, forensic scientists, lawyers, judges, coroners, pathologists and forensic physicians Australian-wide. Five main themes were identified in the data: the silo effect was only partial and in each jurisdiction some form of inter-agency communication was actively occurring; inter-agency meetings were more common in homicide than sexual assault cases; forensic physicians were semi-invisible; there had been considerable momentum over the past ten years for practice improvement groups, and; practitioners gain more benefits than pitfalls from inter-agency information-sharing. Based on these findings, five recommendations are made for improving practice. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Anisotropic mechanical behaviour of sedimentary basins inferred by advanced radar interferometry above gas storage fields

Science.gov (United States)

Teatini, P.; Gambolati, G.; Ferretti, A.

2010-12-01

Natural gas is commonly stored underground in depleted oil and gas fields to provide safe storage capacity and deliverability to market areas where production is limited, or to take advantage of seasonal price swings. In response to summer gas injection and winter gas withdrawal the reservoir expands and contracts with the overlying land that moves accordingly. Depending on the field burial depth, a few kilometres of the upper lithosphere are subject to local three-dimensional deformations with the related cyclic motion of the ground surface being both vertical and horizontal. Advanced Persistent Scatterer Interferometry (PSI) data, obtained by combining ascending and descending RADARSAT-1 images acquired from 2003 to 2008 above gas storage fields located in the sedimentary basin of the Po river plain, Italy, provide reliable measurement of these seasonal vertical ups and downs as well as horizontal displacements to and from the injection/withdrawal wells. Combination of the land surface movements together with an accurate reconstruction of the subsurface geology made available by three-dimensional seismic surveys and long-time records of fluid pore pressure within the 1000-1500 m deep reservoirs has allowed for the development of an accurate 3D poro-mechanical finite-element model of the gas injection/removal occurrence. Model calibration based on the observed cyclic motions, which are on the range of 10-15 mm and 5-10 mm in the vertical and horizontal west-east directions, respectively, helps characterize the nonlinear hysteretic geomechanical properties of the basin. First, using a basin-scale relationship between the oedometric rock compressibility cM in virgin loading conditions versus the effective intergranular stress derived from previous experimental studies, the modeling results show that the ratio s between loading and unloading-reloading cM is about 4, consistent with in-situ expansions measured by the radioactive marker technique in similar reservoirs

Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species

Directory of Open Access Journals (Sweden)

Rachel L Vannette

2013-09-01

Full Text Available Belowground symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above and belowground herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed--which all produce toxic cardenolides--with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in above- and below-ground plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and

Above-ground woody biomass allocation and within tree carbon and nutrient distribution of wild cherry (Prunus avium L. – a case study

Directory of Open Access Journals (Sweden)

Christopher Morhart

2016-02-01

Full Text Available Background: The global search for new ways to sequester carbon has already reached agricultural lands. Such land constitutes a major potential carbon sink. The production of high value timber within agroforestry systems can facilitate an in-situ carbon storage function. This is followed by a potential long term ex- situ carbon sinkwithin long lasting products such as veneer and furniture. For this purpose wild cherry (Prunus avium L. is an interesting option for middle Europe, yielding high prices on the timber market. Methods: A total number of 39 wild cherry were sampled in 2012 and 2013 to assess the leafless above ground biomass. The complete trees including stem and branches were separated into 1 cm diameter classes. Wood and bark from sub-samples were analysed separately and nutrient content was derived. Models for biomass estimation were constructed for all tree compartments. Results: The smallest diameter classes possess the highest proportion of bark due to smaller cross sectional area. Tree boles with a greater amount of stem wood above 10 cm in diameter will have a more constant bark proportion. Total branch bark proportion also remains relatively constant above d1.3m measurements of 8 cm. A balance is evident between the production of new branches with a low diameter and high bark proportion offset by the thickening and a relative reduction in bark proportion in larger branches. The results show that a single tree with an age of 17 and 18 years can store up to 85 kg of carbon within the aboveground biomass portion, an amount that will increase as the tree matures. Branches display greater nutrient content than stem sections per volume unit which can be attributed to a greater bark proportion. Conclusions: Using the derived models the carbon and the nutrient content of above-ground woody biomass of whole trees can be calculated. Suggested values for carbon with other major and minor nutrients held within relatively immature trees

Knowledge silos: assessing knowledge sharing between specialties through the vestibular schwannoma literature.

Science.gov (United States)

Schnurman, Zane; Golfinos, John G; Roland, J Thomas; Kondziolka, Douglas

2017-12-01

OBJECTIVE It is common for a medical disorder to be managed or researched by individuals who work within different specialties. It is known that both neurosurgeons and neurotologists manage vestibular schwannoma (VS) patients. While overlap in specialty focus has the potential to stimulate multidisciplinary collaboration and innovative thinking, there is a risk of specialties forming closed-communication loops, called knowledge silos, which may inhibit knowledge diffusion. This study quantitatively assessed knowledge sharing between neurosurgery and otolaryngology on the subject of VS. METHODS A broad Web of Science search was used to download details for 4439 articles related to VS through 2016. The publishing journal's specialty and the authors' specialties (based on author department) were determined for available articles. All 114,647 of the article references were categorized by journal specialty. The prevalence of several VS topics was assessed using keyword searches of titles. RESULTS For articles written by neurosurgeons, 44.0% of citations were from neurosurgery journal articles and 23.4% were from otolaryngology journals. The citations of otolaryngology authors included 11.6% neurosurgery journals and 56.5% otolaryngology journals. Both author specialty and journal specialty led to more citations of the same specialty, though author specialty had the largest effect. Comparing the specialties' literature, several VS topics had significantly different levels of coverage, including radiosurgery and hearing topics. Despite the availability of the Internet, there has been no change in the proportions of references for either specialty since 1997 (the year PubMed became publicly available). CONCLUSIONS Partial knowledge silos are observed between neurosurgery and otolaryngology on the topic of VS, based on the peer-reviewed literature. The increase in access provided by the Internet and searchable online databases has not decreased specialty reference bias

Chip-scale fluorescence microscope based on a silo-filter complementary metal-oxide semiconductor image sensor.

Science.gov (United States)

Ah Lee, Seung; Ou, Xiaoze; Lee, J Eugene; Yang, Changhuei

2013-06-01

We demonstrate a silo-filter (SF) complementary metal-oxide semiconductor (CMOS) image sensor for a chip-scale fluorescence microscope. The extruded pixel design with metal walls between neighboring pixels guides fluorescence emission through the thick absorptive filter to the photodiode of a pixel. Our prototype device achieves 13 μm resolution over a wide field of view (4.8 mm × 4.4 mm). We demonstrate bright-field and fluorescence longitudinal imaging of living cells in a compact, low-cost configuration.

Measurement of ground and nearby building vibration and noise induced by trains in a metro depot.

Science.gov (United States)

Zou, Chao; Wang, Yimin; Wang, Peng; Guo, Jixing

2015-12-01

Metro depots are where subway trains are parked and where maintenance is carried out. They usually occupy the largest ground areas in metro projects. Due to land utilization problems, Chinese cities have begun to develop over-track buildings above metro depots for people's life and work. The frequently moving trains, when going into and out of metro depots, can cause excessive vibration and noise to over-track buildings and adversely affect the living quality of the building occupants. Considering the current need of reliable experimental data for the construction of metro depots, field measurements of vibration and noise on the ground and inside a nearby 3-story building subjected to moving subway trains were conducted in a metro depot at Guangzhou, China. The amplitudes and frequency contents of velocity levels were quantified and compared. The composite A-weighted equivalent sound levels and maximum sound levels were captured. The predicted models for vibration and noise of metro depot were proposed based on existing models and verified. It was found that the vertical vibrations were significantly greater than the horizontal vibrations on the ground and inside the building near the testing line. While at the throat area, the horizontal vibrations near the curved track were remarkably greater than the vertical vibrations. The attenuation of the vibrations with frequencies above 50 Hz was larger than the ones below 50 Hz, and the frequencies of vibration transmitting to adjacent buildings were mainly within 10-50 Hz. The largest equivalent sound level generated in the throat area was smaller than the testing line one, but the instantaneous maximum sound level induced by wheels squeal, contact between wheels and rail joints as well as turnout was close to or even greater than the testing line one. The predicted models gave a first estimation for design and assessment of newly built metro depots. Copyright © 2015 Elsevier B.V. All rights reserved.

Dispersion of a Passive Scalar Within and Above an Urban Street Network

Science.gov (United States)

Goulart, E. V.; Coceal, O.; Belcher, S. E.

2018-03-01

The transport of a passive scalar from a continuous point-source release in an urban street network is studied using direct numerical simulation (DNS). Dispersion through the network is characterized by evaluating horizontal fluxes of scalar within and above the urban canopy and vertical exchange fluxes through the canopy top. The relative magnitude and balance of these fluxes are used to distinguish three different regions relative to the source location: a near-field region, a transition region and a far-field region. The partitioning of each of these fluxes into mean and turbulent parts is computed. It is shown that within the canopy the horizontal turbulent flux in the street network is small, whereas above the canopy it comprises a significant fraction of the total flux. Vertical fluxes through the canopy top are predominantly turbulent. The mean and turbulent fluxes are respectively parametrized in terms of an advection velocity and a detrainment velocity and the parametrization incorporated into a simple box-network model. The model treats the coupled dispersion problem within and above the street network in a unified way and predictions of mean concentrations compare well with the DNS data. This demonstrates the usefulness of the box-network approach for process studies and interpretation of results from more detailed numerical simulations.

Results on MeV-scale dark matter from a gram-scale cryogenic calorimeter operated above ground

Energy Technology Data Exchange (ETDEWEB)

Angloher, G.; Bauer, P.; Bento, A.; Iachellini, N.F.; Hauff, D.; Kiefer, M.; Mancuso, M.; Petricca, F.; Proebst, F.; Reindl, F.; Rothe, J.; Seidel, W.; Stodolsky, L.; Strauss, R.; Tanzke, A.; Wuestrich, M. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Bucci, C.; Canonica, L.; Gorla, P.; Pagliarone, C.; Schaeffner, K. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Defay, X.; Erb, A.; Feilitzsch, F. v.; Lanfranchi, J.C.; Langenkaemper, A.; Mondragon, E.; Muenster, A.; Oberauer, L.; Potzel, W.; Schoenert, S.; Thi, H.H.T.; Ulrich, A.; Wawoczny, S.; Willers, M.; Zoeller, A. [Technische Universitaet Muenchen, Physik-Department and Excellence Cluster Universe, Garching (Germany); Guetlein, A.; Kluck, H.; Puig, R.; Schieck, J.; Stahlberg, M.; Tuerkoglu, C. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Vienna (Austria); Vienna University of Technology, Atominstitut, Vienna (Austria); Jochum, J.; Loebell, J.; Strandhagen, C.; Uffinger, M.; Usherov, I. [Eberhard-Karls-Universitaet Tuebingen, Tuebingen (Germany); Kraus, H. [University of Oxford, Department of Physics, Oxford (United Kingdom); Collaboration: CRESST Collaboration

2017-09-15

Models for light dark matter particles with masses below 1 GeV/c{sup 2} are a natural and well-motivated alternative to so-far unobserved weakly interacting massive particles. Gram-scale cryogenic calorimeters provide the required detector performance to detect these particles and extend the direct dark matter search program of CRESST. A prototype 0.5 g sapphire detector developed for the ν-cleus experiment has achieved an energy threshold of E{sub th} = (19.7 ± 0.9)eV. This is one order of magnitude lower than for previous devices and independent of the type of particle interaction. The result presented here is obtained in a setup above ground without significant shielding against ambient and cosmogenic radiation. Although operated in a high-background environment, the detector probes a new range of light-mass dark matter particles previously not accessible by direct searches. We report the first limit on the spin-independent dark matter particle-nucleon cross section for masses between 140 and 500 MeV/c{sup 2}. (orig.)

Results on MeV-scale dark matter from a gram-scale cryogenic calorimeter operated above ground

Science.gov (United States)

Angloher, G.; Bauer, P.; Bento, A.; Bucci, C.; Canonica, L.; Defay, X.; Erb, A.; Feilitzsch, F. v.; Iachellini, N. Ferreiro; Gorla, P.; Gütlein, A.; Hauff, D.; Jochum, J.; Kiefer, M.; Kluck, H.; Kraus, H.; Lanfranchi, J.-C.; Langenkämper, A.; Loebell, J.; Mancuso, M.; Mondragon, E.; Münster, A.; Oberauer, L.; Pagliarone, C.; Petricca, F.; Potzel, W.; Pröbst, F.; Puig, R.; Reindl, F.; Rothe, J.; Schäffner, K.; Schieck, J.; Schönert, S.; Seidel, W.; Stahlberg, M.; Stodolsky, L.; Strandhagen, C.; Strauss, R.; Tanzke, A.; Thi, H. H. Trinh; Türkoǧlu, C.; Uffinger, M.; Ulrich, A.; Usherov, I.; Wawoczny, S.; Willers, M.; Wüstrich, M.; Zöller, A.

2017-09-01

Models for light dark matter particles with masses below 1 GeV/c^2 are a natural and well-motivated alternative to so-far unobserved weakly interacting massive particles. Gram-scale cryogenic calorimeters provide the required detector performance to detect these particles and extend the direct dark matter search program of CRESST. A prototype 0.5 g sapphire detector developed for the ν -cleus experiment has achieved an energy threshold of E_{th}=(19.7± 0.9) eV. This is one order of magnitude lower than for previous devices and independent of the type of particle interaction. The result presented here is obtained in a setup above ground without significant shielding against ambient and cosmogenic radiation. Although operated in a high-background environment, the detector probes a new range of light-mass dark matter particles previously not accessible by direct searches. We report the first limit on the spin-independent dark matter particle-nucleon cross section for masses between 140 and 500 MeV/c^2.

Numerical and experimental analysis of a horizontal ground-coupled heat pump system

Energy Technology Data Exchange (ETDEWEB)

Esen, Hikmet; Esen, Mehmet [Department of Mechanical Education, Faculty of Technical Education, University of Firat, 23119 Elazig (Turkey); Inalli, Mustafa [Department of Mechanical Engineering, Faculty of Engineering, University of Firat, 23119 Elazig (Turkey)

2007-03-15

The main objective of this work is to evaluate a heat pump system using the ground as a source of heat. A ground-coupled heat pump (GCHP) system has been installed and tested at the test room, University of Firat, Elazig, Turkey. Results obtained during experimental testing are presented and discussed here. The coefficient of performance (COP{sub sys}) of the GCHP system is determined from the measured data. A numerical model of heat transfer in the ground was developed for determining the temperature distribution in the vicinity of the pipe. The finite difference approximation is used for numerical analysis. It is observed that the numerical results agree with the experimental results. (author) (author)

BEARING CAPACITY OF A HORIZONTALLY LOADED SINGLE PILE SUPPORT WITH SLEEPERS

Directory of Open Access Journals (Sweden)

Buslov Anatoliy Semenovich

2015-09-01

Full Text Available The supports of a overhead wiring used in transport take up substantial loads both because of wires and constructions holding them and wind, dynamic and other extraordinary impacts. In case of using single-member piles a question about their stability appears. For this reason different sleepers constructions are used. In order to improve the bearing capacity of horizontally loaded single pile supports of the contact systems used in urban, road and rail transport, power lines, etc.., it is recommended to use sleepers as horizontally laid under the ground in the depth of support beams. The calculation methods for different support sleepers of different lengths and cross sections are not well investigated. The proposed calculation method allows determining the carrying capacity of horizontally loaded bearings with soil pieces of different structural dimensions and their location in the soil, which allows choosing the best option for cost and material consumption. The calculations offered by the authors prove the efficiency of sleepers use in order to increase the bearing capacity of horizontally loaded piles and the possibility to chose their size.

Horizontal above-rack pool storage

International Nuclear Information System (INIS)

Moscardini, R.L.

1993-08-01

This report describes a unique method for storing spent, six year out of core, fuel at a prototypical PWR nuclear power station. The study describes a conceptual design, with favorable structural, thermal and criticality technical evaluations. However, economic considerations and licensing risks are judged to be less favorable. The concept study prescribes a fuel over fuel arrangement in an existing Spent Fuel Pool (SFP) with full maintenance of ALARA principles. This concept study is specific to a prototypical pool design, but may easily be projected to other nuclear facilities with other SFP conditions. For the prototypical PWR, the conceptual fuel bridge design will store over 200 additional fuel assemblies without significant facility modifications and for an indefinite time period

Fighting Smoldering Fires in Silos – A Cautionary Note on Using Carbon Dioxide to Inert

DEFF Research Database (Denmark)

Hedlund, Frank Huess

2017-01-01

This communication seeks to draw attention to the hazards of releasing liquid carbon dioxide into environments where an ignitable atmosphere may exist. Static discharges have sufficient energy to ignite flammable vapors and an internal explosion may result when fighting smoldering fires using...... this approach. A recent article in Biomass and Bioenergy examines an explosion in a Norwegian wood pellet silo when attempting to suppress a smoldering fire with CO₂. The article argues that the electrostatic hazard of CO₂ is widely under-appreciated and incidents like this are avoidable....

Salida de campo a Santo Domingo de Silos, en Burgos, el 14 de septiembre de 1953

OpenAIRE

Valverde Gómez, José Antonio, 1926-2003

2008-01-01

Salida de campo a Santo Domingo de Silos, en Burgos, el 14 de septiembre de 1953, de la que se anotaron observaciones sobre cangrejos, los siguientes peces: "Foxinellus sp." y Trucha (Salmo trutta o Oncorhynchus mykiss), los siguientes mamíferos: Bos taurus (Vaca), Capra aegagrus hircus (Cabra doméstica) y Galemys pyrenaicus (Desmán pirenaico), y las siguientes aves: Aquila sp. (Águila), Carduelis cannabina (Pardillo común, llamada Colorín y Acanthis cannabina por el autor), Carduelis carduel...

Advice about the safety of graphite storage silos of Saint Laurent des Eaux facility; Avis sur la surete des silos de stockage de graphite de Saint Laurent des Eaux

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

This document is the safety analysis made by the national association of the local commissions of information about nuclear activities (ANCLI), about the safety of graphite storage silos of Saint Laurent des Eaux nuclear facility. The analysis covers: the operation safety and the accident hypothesis, the monitoring of indoor and outdoor contamination in routine situation, the geotechnical characteristics of the site environment, the isotopic inventory and the estimation of radioactivity in routine and accidental situation, the estimation of doses received by the population in accidental situation and the internal emergency plan. After examination of these different points, the scientific committee of the ANCLI considers that a new global evaluation of risks, which integrates more recent exposure data, has to be carried out. (J.S.)

Dismantling the justice silos: Flowcharting the role and expertise of forensic science, forensic medicine and allied health in adult sexual assault investigations.

Science.gov (United States)

Kelty, Sally F; Julian, Roberta; Bruenisholz, Eva; Wilson-Wilde, Linzi

2018-04-01

Forensic science is increasingly used to help exonerate the innocent and establishing links between individuals and criminal activities. With increased reliance on scientific services provided by multi-disciplinary (police, medicine, law, forensic science), and multi-organisational in the private and government sectors (health, justice, legal, police) practitioners, the potential for miscommunication resulting unjust outcomes increases. The importance of identifying effective multi-organisational information sharing is to prevent the 'justice silo effect'; where practitioners from different organisations operate in isolation with minimal or no interaction. This paper presents the findings from the second part of the Interfaces Project, an Australia-wide study designed to assess the extent of the justice silos. We interviewed 121 police, forensic scientists, lawyers, judges, coroners, pathologists and forensic physicians. The first paper published in 2013 presented two key findings: first investigative meetings were rare in adult sexual assault cases; second many medical practitioners were semi-invisible in case decision-making with this low level of visibility being due to lawyers, forensic scientists or police not being aware of the role/expertise medical practitioners offer. These findings led to the development of a flowchart model for adult sexual assault that highlights the range of agencies and practitioners typically involved in sexual assault. The rationale for the flowchart is to produce a visual representation of a typical sexual assault investigative process highlighting where and who plays a role in order to minimise the risk of justice silos. This is the second paper in a series of two. Copyright © 2018 Elsevier B.V. All rights reserved.

Assessment of potential strong ground motions in the city of Rome

Directory of Open Access Journals (Sweden)

L. Malagnini

1994-06-01

Full Text Available A methodology is used which combines stochastic generation of random series with a finite-difference technique to estimate the expected horizontal ground motion for the city of Rome as induced by a large earthquake in the Central Apennines. In this approach, source properties and long-path propagation are modelled through observed spectra of ground motion in the region, while the effects of the near-surface geology in the city are simulated by means of a finite-difference technique applied to 2-D models including elastic and anelastic properties of geologic materials and topographic variations. The parameters commonly used for earthquake engineering purposes are estimated from the simulated time histories of horizontal ground motion. We focus our attention on peak ground acceleration and velocity, and on the integral of the squared acceleration and velocity (that are proportional to the Arias intensity and seismic energy flux, respectively. Response spectra are analyzed as well. Parameter variations along 2-D profiles visualize the effects of the small-scale geological heterogeneities and topography irregularities on ground motion in the case of a strong earthquake. Interestingly, the largest amplification of peak ground acceleration and Arias intensity does not necessarily occur at the same sites where peak ground velocity and flux of seismic energy reach their highest values, depending on the frequency band of amplification. A magnitude 7 earthquake at a distance of 100 km results in peak ground accelerations ranging from 30 to 70 gals while peak ground velocities are estimated to vary from 5 to 7 cm/s; moreover, simulated time histories of horizontal ground motion yield amplitudes of 5% damped pseudovelocity response spectra as large as 15-20 cm/s for frequencies from 1to 3 Hz. In this frequency band, the mean value is 7 cm/s for firm sites and ranges from 10 to 13 cm/s for soil sites. All these results are in good agreement with predictions

The relationship between growth and development of above ground organs with roots of winter wheat using 32P tracer

International Nuclear Information System (INIS)

Wang Zhifen; Chen Xueliu; Yu Meiyan

1997-01-01

The relationship of growth and development between above ground organs and roots of winter wheat, Lumai-14, was studied using 32 P tracer. The results showed that before the spike formation, dry matter accumulation in roots, stems and leaves were synchronous, and after that they were asynchronous. The dry matter accumulation in stems and leaves were significantly related to that of roots throughout the whole growing period of winter wheat. After the spike formation, the dry matter accumulation in spikes was not related to that of roots. The 32 P distribution in stems and leaves were related to that of roots significantly, however, the relationship between spikes and roots was not obviously related, which was consistent with the dry matter accumulations in various organs. The metabolic activities of stems, leaves and spike were significantly related to that of roots respectively

Evaluation of ground water nutrient loading to Priest Lake, Bonner County, Idaho

International Nuclear Information System (INIS)

Freeman, K.M.; Ralston, D.R.

1994-01-01

The quality of water of Idaho lakes is of increasing concern, particularly when related to waste disposal and land use practices within the watersheds. This study investigates the Kalispell Bay and Granite Creek areas. Conclusions are as follows: Both areas demonstrate direction of ground water towards Priest Lake. The Kalispell Bay area displays horizontal ground water flow throughout the entire area with an upward hydraulic gradient over a portion of the area. The Granite Creek Area displays strictly horizontal flow; both study areas contain particular sub-areas which display nutrient enrichment, particulary nitrogen, of ground water; the granite Creek study area contains a sub-area displaying both elevated nitrogen concentrations and positive tests for E. coli bacteria. 2 figs., 2 tabs

Probabilistic seismic hazard assessment for the effect of vertical ground motions on seismic response of highway bridges

Science.gov (United States)

Yilmaz, Zeynep

Typically, the vertical component of the ground motion is not considered explicitly in seismic design of bridges, but in some cases the vertical component can have a significant effect on the structural response. The key question of when the vertical component should be incorporated in design is answered by the probabilistic seismic hazard assessment study incorporating the probabilistic seismic demand models and ground motion models. Nonlinear simulation models with varying configurations of an existing bridge in California were considered in the analytical study. The simulation models were subjected to the set of selected ground motions in two stages: at first, only horizontal components of the motion were applied; while in the second stage the structures were subjected to both horizontal and vertical components applied simultaneously and the ground motions that produced the largest adverse effects on the bridge system were identified. Moment demand in the mid-span and at the support of the longitudinal girder and the axial force demand in the column are found to be significantly affected by the vertical excitations. These response parameters can be modeled using simple ground motion parameters such as horizontal spectral acceleration and vertical spectral acceleration within 5% to 30% error margin depending on the type of the parameter and the period of the structure. For a complete hazard assessment, both of these ground motion parameters explaining the structural behavior should also be modeled. For the horizontal spectral acceleration, Abrahamson and Silva (2008) model was used within many available standard model. A new NGA vertical ground motion model consistent with the horizontal model was constructed. These models are combined in a vector probabilistic seismic hazard analyses. Series of hazard curves developed and presented for different locations in Bay Area for soil site conditions to provide a roadmap for the prediction of these features for future

Simulation of ground-water flow and land subsidence in the Antelope Valley ground-water basin, California

Science.gov (United States)

Leighton, David A.; Phillips, Steven P.

2003-01-01

Antelope Valley, California, is a topographically closed basin in the western part of the Mojave Desert, about 50 miles northeast of Los Angeles. The Antelope Valley ground-water basin is about 940 square miles and is separated from the northern part of Antelope Valley by faults and low-lying hills. Prior to 1972, ground water provided more than 90 percent of the total water supply in the valley; since 1972, it has provided between 50 and 90 percent. Most ground-water pumping in the valley occurs in the Antelope Valley ground-water basin, which includes the rapidly growing cities of Lancaster and Palmdale. Ground-water-level declines of more than 200 feet in some parts of the ground-water basin have resulted in an increase in pumping lifts, reduced well efficiency, and land subsidence of more than 6 feet in some areas. Future urban growth and limits on the supply of imported water may continue to increase reliance on ground water. To better understand the ground-water flow system and to develop a tool to aid in effectively managing the water resources, a numerical model of ground-water flow and land subsidence in the Antelope Valley ground-water basin was developed using old and new geohydrologic information. The ground-water flow system consists of three aquifers: the upper, middle, and lower aquifers. The aquifers, which were identified on the basis of the hydrologic properties, age, and depth of the unconsolidated deposits, consist of gravel, sand, silt, and clay alluvial deposits and clay and silty clay lacustrine deposits. Prior to ground-water development in the valley, recharge was primarily the infiltration of runoff from the surrounding mountains. Ground water flowed from the recharge areas to discharge areas around the playas where it discharged either from the aquifer system as evapotranspiration or from springs. Partial barriers to horizontal ground-water flow, such as faults, have been identified in the ground-water basin. Water-level declines owing to

Statistical studies of vertical and horizontal earthquake spectra

Energy Technology Data Exchange (ETDEWEB)

Hall, W.J.; Mohraz, B.; Newmark, N.M.

1976-01-01

The study reveals that there is no well-defined dependence of normalized seismic design response spectra on the earthquake ground acceleration level. Recommendations for horizontal design response spectra are close to those given in Regulatory Guide 1.60. Recommendations for vertical response spectra are somewhat lower than Regulatory Guide 1.60 provisions in the frequency range 2 to 30 Hz aproximately. The results are based on seismic information recorded along the west coast of the United States and are directly applicable to that region only.

Two dimensional neutron transport calculation system for plate-reactors: experimental design and qualification with SILOE

International Nuclear Information System (INIS)

Roussos, N.

1982-01-01

The main objective of this work is to create a neutronic calculations system for the SILOE-SILOETTE reactors, adaptable to other types of plate reactors. The author presents the methodology and the development of the APOLLO 1D (99 gr.) calculations for the creation of cross sections libraries. After a recall of the Discrete Ordinate Method (DOT), the method accuracy is studied in order to optimize the spatial discretization of the calculations; calculations of DOT 3.5 and of SILOETTE core are conducted and their convergence and costs are examined. DOT calculations of SILOETTE and experimental tests results are then compared [fr

Calculation of Grounding Grids Parameter at Arbitrary Geometry

Directory of Open Access Journals (Sweden)

Carlos L. B. Silva

2017-06-01

Full Text Available This paper deals with the computation of ground resistance, surface voltage, touch voltage and step voltage, to mesh with horizontal wires arranged in different angles. The computer program implemented used in the mathematical modeling is based on the method proposed by Heppe, which allows obtaining the grounding parameters for homogeneous soil and soil stratified in two layers. The results obtained with the proposed method will be compared with other methods in literature. Also will be presented the results of a grounding grid using wires at various angles.

Microbial processes in the final repository, the silo part. Theoretical approach and preliminary experiments on the biodegradation of bitumen. Part 1

International Nuclear Information System (INIS)

Roffey, R.; Hjalmarsson, K.

1984-01-01

On Commission of SKBF/KBS the microbial processes that are likely to occur in the silo part of SFR, the final repository for medium- and low-level nuclear wastes, have been put together. The experimental studies concerning microbial degradation of bitumen are described. From a microbial point of view it is the biodegradation of bitumen that constitutes the greatest risk in the silo part of SFR. The degradation, aerobic as well as anaerobic, leads to production of carbon dioxide which might cause a decrease in pH to such an extent that hydrogen-gas producing corrosion of metal could occur. This production of gas can cause an increase in internal pressure of the repository. A culture of bacteria able to degrade bitumen aerobically has been enriched. Uptil now no culture degrading bitumen under anaerobic conditions have been obtained. When making a risk assessment of the SFR at the present time it is not possible to completely disregard the microbial activity. An account is also given for some international contacts in this area. 11 references

Creating value: unifying silos into public health business intelligence.

Science.gov (United States)

Davidson, Arthur J

2014-01-01

Through September 2014, federal investments in health information technology have been unprecedented, with more than 25 billion dollars in incentive funds distributed to eligible hospitals and providers. Over 85 percent of eligible United States hospitals and 60 percent of eligible providers have used certified electronic health record (EHR) technology and received Meaningful Use incentive funds (HITECH Act1). Certified EHR technology could create new public health (PH) value through novel and rapidly evolving data-use opportunities, never before experienced by PH. The long-standing "silo" approach to funding has fragmented PH programs and departments,2 but the components for integrated business intelligence (i.e., tools and applications to help users make informed decisions) and maximally reuse data are available now. Challenges faced by PH agencies on the road to integration are plentiful, but an emphasis on PH systems and services research (PHSSR) may identify gaps and solutions for the PH community to address. Technology and system approaches to leverage this information explosion to support a transformed health care system and population health are proposed. By optimizing this information opportunity, PH can play a greater role in the learning health system.

Modeling Water and Nutrient Transport through the Soil-Root-Canopy Continuum: Explicitly Linking the Below- and Above-Ground Processes

Science.gov (United States)

Kumar, P.; Quijano, J. C.; Drewry, D.

2010-12-01

Vegetation roots provide a fundamental link between the below ground water and nutrient dynamics and above ground canopy processes such as photosynthesis, evapotranspiration and energy balance. The “hydraulic architecture” of roots, consisting of the structural organization of the root system and the flow properties of the conduits (xylem) as well as interfaces with the soil and the above ground canopy, affect stomatal conductance thereby directly linking them to the transpiration. Roots serve as preferential pathways for the movement of moisture from wet to dry soil layers during the night, both from upper soil layer to deeper layers during the wet season (‘hydraulic descent’) and vice-versa (‘hydraulic lift’) as determined by the moisture gradients. The conductivities of transport through the root system are significantly, often orders of magnitude, larger than that of the surrounding soil resulting in movement of soil-moisture at rates that are substantially larger than that through the soil. This phenomenon is called hydraulic redistribution (HR). The ability of the deep-rooted vegetation to “bank” the water through hydraulic descent during wet periods for utilization during dry periods provides them with a competitive advantage. However, during periods of hydraulic lift these deep-rooted trees may facilitate the growth of understory vegetation where the understory scavenges the hydraulically lifted soil water. In other words, understory vegetation with relatively shallow root systems have access to the banked deep-water reservoir. These inter-dependent root systems have a significant influence on water cycle and ecosystem productivity. HR induced available moisture may support rhizosphere microbial and mycorrhizal fungi activities and enable utilization of heterogeneously distributed water and nutrient resources To capture this complex inter-dependent nutrient and water transport through the soil-root-canopy continuum we present modeling

Modelling above Ground Biomass in Tanzanian Miombo Woodlands Using TanDEM-X WorldDEM and Field Data

Directory of Open Access Journals (Sweden)

Stefano Puliti

2017-09-01

Full Text Available The use of Interferometric Synthetic Aperture Radar (InSAR data has great potential for monitoring large scale forest above ground biomass (AGB in the tropics due to the increased ability to retrieve 3D information even under cloud cover. To date; results in tropical forests have been inconsistent and further knowledge on the accuracy of models linking AGB and InSAR height data is crucial for the development of large scale forest monitoring programs. This study provides an example of the use of TanDEM-X WorldDEM data to model AGB in Tanzanian woodlands. The primary objective was to assess the accuracy of a model linking AGB with InSAR height from WorldDEM after the subtraction of ground heights. The secondary objective was to assess the possibility of obtaining InSAR height for field plots when the terrain heights were derived from global navigation satellite systems (GNSS; i.e., as an alternative to using airborne laser scanning (ALS. The results revealed that the AGB model using InSAR height had a predictive accuracy of R M S E = 24.1 t·ha−1; or 38.8% of the mean AGB when terrain heights were derived from ALS. The results were similar when using terrain heights from GNSS. The accuracy of the predicted AGB was improved when compared to a previous study using TanDEM-X for a sub-area of the area of interest and was of similar magnitude to what was achieved in the same sub-area using ALS data. Overall; this study sheds new light on the opportunities that arise from the use of InSAR data for large scale AGB modelling in tropical woodlands.

Water activities in Forsmark (Part II). The final disposal facility for spent fuel: water activities above ground; Vattenverksamhet i Forsmark (del II). Slutfoervarsanlaeggningen foer anvaent kaernbraensle: Vattenverksamheter ovan mark

Energy Technology Data Exchange (ETDEWEB)

Werner, Kent [EmpTec (Sweden); Hamren, Ulrika; Collinder, Per [Ekologigruppen AB (Sweden); Ridderstolpe, Peter [WRS Uppsala AB (Sweden)

2010-09-15

The construction of the repository for spent nuclear fuel in Forsmark is associated with a number of measures above ground that constitute water operations according to Chapter 11 in the Swedish Environmental Code. This report, which is an appendix to the Environmental Impact Assessment, describes these water operations, their effects and consequences, and planned measures

Testing the generality of above-ground biomass allometry across plant functional types at the continent scale.

Science.gov (United States)

Paul, Keryn I; Roxburgh, Stephen H; Chave, Jerome; England, Jacqueline R; Zerihun, Ayalsew; Specht, Alison; Lewis, Tom; Bennett, Lauren T; Baker, Thomas G; Adams, Mark A; Huxtable, Dan; Montagu, Kelvin D; Falster, Daniel S; Feller, Mike; Sochacki, Stan; Ritson, Peter; Bastin, Gary; Bartle, John; Wildy, Dan; Hobbs, Trevor; Larmour, John; Waterworth, Rob; Stewart, Hugh T L; Jonson, Justin; Forrester, David I; Applegate, Grahame; Mendham, Daniel; Bradford, Matt; O'Grady, Anthony; Green, Daryl; Sudmeyer, Rob; Rance, Stan J; Turner, John; Barton, Craig; Wenk, Elizabeth H; Grove, Tim; Attiwill, Peter M; Pinkard, Elizabeth; Butler, Don; Brooksbank, Kim; Spencer, Beren; Snowdon, Peter; O'Brien, Nick; Battaglia, Michael; Cameron, David M; Hamilton, Steve; McAuthur, Geoff; Sinclair, Jenny

2016-06-01

Accurate ground-based estimation of the carbon stored in terrestrial ecosystems is critical to quantifying the global carbon budget. Allometric models provide cost-effective methods for biomass prediction. But do such models vary with ecoregion or plant functional type? We compiled 15 054 measurements of individual tree or shrub biomass from across Australia to examine the generality of allometric models for above-ground biomass prediction. This provided a robust case study because Australia includes ecoregions ranging from arid shrublands to tropical rainforests, and has a rich history of biomass research, particularly in planted forests. Regardless of ecoregion, for five broad categories of plant functional type (shrubs; multistemmed trees; trees of the genus Eucalyptus and closely related genera; other trees of high wood density; and other trees of low wood density), relationships between biomass and stem diameter were generic. Simple power-law models explained 84-95% of the variation in biomass, with little improvement in model performance when other plant variables (height, bole wood density), or site characteristics (climate, age, management) were included. Predictions of stand-based biomass from allometric models of varying levels of generalization (species-specific, plant functional type) were validated using whole-plot harvest data from 17 contrasting stands (range: 9-356 Mg ha(-1) ). Losses in efficiency of prediction were <1% if generalized models were used in place of species-specific models. Furthermore, application of generalized multispecies models did not introduce significant bias in biomass prediction in 92% of the 53 species tested. Further, overall efficiency of stand-level biomass prediction was 99%, with a mean absolute prediction error of only 13%. Hence, for cost-effective prediction of biomass across a wide range of stands, we recommend use of generic allometric models based on plant functional types. Development of new species

Análisis de la distribución de presiones estáticas en silos cilíndricos con tolva excéntrica mediante el M. E. F. Influencia de la excentricidad y comparación con el Eurocódigo 1

Directory of Open Access Journals (Sweden)

Vidal López, Pablo

2001-04-01

Full Text Available At the European level, silos are considered under the European Standards (Eurocode 1, Part 4. Actions in si/os and tanks, with no proposed method of calculation in the case of an eccentric outlet. The guidelines include a brief mention that eccentricity should not exceed 25% of the silo diameter and that in the future, attempts will be made to cover large eccentricities. We have developed an analysis of static pressure distributions in grain silos with eccentric outlets. To this end, silos were modelled using ANSYS 5.5. According to the F.E.M. maximum normal pressures on the silo wall correspond to the si/o-hopper junction. on the opposite side to the displacement of the outlet for any eccentricity, increasing at this point as hopper eccentricity rises. Compared to the Eurocode, static pressures are proposed when the hopper is centered and considered to be valid up to an eccentricity limit of 0.25 times the diameter , their redistribution at the hopper wall when this is eccentric may be observed by means of the FE.M. increasing on the opposite side to the outlet and decreasing on the same side with respect to the central hopper. This leads us to conclude that a more conservative method of calculation should be used in the Eurocode for normal pressures on the hopper wall when centered, and coefficients drawn up to include the variations produced in the static state when it is off-center.En Europa las acciones en silos se recogen en la Norma Europea (ENV 1991-4. Eurocode l. Part 4: Actions on silos and tanks., sin proponer método alguno de cálculo cuando la boca de salida es excéntrica, limitándose a mencionar que la excentricidad de ésta no debe de ser mayor del 25% del diámetro y mencionando que en un futuro se intentará que cubra las grandes excentricidades. En este artículo realizamos un análisis de la distribución de presiones estáticas en silos cilíndricos con tolva excéntrica. Para ello hemos usado el programa ANSYS 5.5. con

Wind observations above an urban river using a new lidar technique, scintillometry and anemometry

Energy Technology Data Exchange (ETDEWEB)

Wood, C.R. [Department of Meteorology, University of Reading, Reading, RG6 6BB (United Kingdom); Finnish Meteorological Institute, Erik Palmenin aukio 1, Helsinki, 00101 (Finland); Pauscher, L. [King' s College London, Department of Geography, London, WC2R 2LS (United Kingdom); Ward, H.C. [King' s College London, Department of Geography, London, WC2R 2LS (United Kingdom); Centre for Ecology and Hydrology, Wallingford, Oxfordshire, OX10 8BB (United Kingdom); Kotthaus, S. [King' s College London, Department of Geography, London, WC2R 2LS (United Kingdom); Barlow, J.F., E-mail: j.f.barlow@reading.ac.uk [Department of Meteorology, University of Reading, Reading, RG6 6BB (United Kingdom); Gouvea, M. [King' s College London, Department of Geography, London, WC2R 2LS (United Kingdom); Lane, S.E. [Department of Meteorology, University of Reading, Reading, RG6 6BB (United Kingdom); Grimmond, C.S.B. [King' s College London, Department of Geography, London, WC2R 2LS (United Kingdom)

2013-01-01

Airflow along rivers might provide a key mechanism for ventilation in cities: important for air quality and thermal comfort. Airflow varies in space and time in the vicinity of rivers. Consequently, there is limited utility in point measurements. Ground-based remote sensing offers the opportunity to study 3D airflow in locations which are difficult to observe with conventional approaches. For three months in the winter and spring of 2011, the airflow above the River Thames in central London was observed using a scanning Doppler lidar, a scintillometer and sonic anemometers. First, an inter-comparison showed that lidar-derived mean wind-speed estimates compare almost as well to sonic anemometers (root-mean-square error (rmse) 0.65-0.68 m s{sup -1}) as comparisons between sonic anemometers (0.35-0.73 m s{sup -1}). Second, the lidar duo-beam operating strategy provided horizontal transects of wind vectors (comparison with scintillometer rmse 1.12-1.63 m s{sup -1}) which revealed mean and turbulent airflow across the river and surrounds; in particular, channelled airflow along the river and changes in turbulence quantities consistent with the roughness changes between built and river environments. The results have important consequences for air quality and dispersion around urban rivers, especially given that many cities have high traffic rates on roads located on riverbanks. -- Highlights: Black-Right-Pointing-Pointer An inter-comparison was made between lidar-derived winds and regular anemometry. Black-Right-Pointing-Pointer A new lidar operating technique was developed. Black-Right-Pointing-Pointer Airflow features above an urban river included channelling of wind.

Wind observations above an urban river using a new lidar technique, scintillometry and anemometry

International Nuclear Information System (INIS)

Wood, C.R.; Pauscher, L.; Ward, H.C.; Kotthaus, S.; Barlow, J.F.; Gouvea, M.; Lane, S.E.; Grimmond, C.S.B.

2013-01-01

Airflow along rivers might provide a key mechanism for ventilation in cities: important for air quality and thermal comfort. Airflow varies in space and time in the vicinity of rivers. Consequently, there is limited utility in point measurements. Ground-based remote sensing offers the opportunity to study 3D airflow in locations which are difficult to observe with conventional approaches. For three months in the winter and spring of 2011, the airflow above the River Thames in central London was observed using a scanning Doppler lidar, a scintillometer and sonic anemometers. First, an inter-comparison showed that lidar-derived mean wind-speed estimates compare almost as well to sonic anemometers (root-mean-square error (rmse) 0.65–0.68 m s −1 ) as comparisons between sonic anemometers (0.35–0.73 m s −1 ). Second, the lidar duo-beam operating strategy provided horizontal transects of wind vectors (comparison with scintillometer rmse 1.12–1.63 m s −1 ) which revealed mean and turbulent airflow across the river and surrounds; in particular, channelled airflow along the river and changes in turbulence quantities consistent with the roughness changes between built and river environments. The results have important consequences for air quality and dispersion around urban rivers, especially given that many cities have high traffic rates on roads located on riverbanks. -- Highlights: ► An inter-comparison was made between lidar-derived winds and regular anemometry. ► A new lidar operating technique was developed. ► Airflow features above an urban river included channelling of wind.

Vertical distribution of hydrocarbons in the low troposphere below and above the mixing height: tethered balloon measurements in Milan, Italy.

Science.gov (United States)

Sangiorgi, G; Ferrero, L; Perrone, M G; Bolzacchini, E; Duane, M; Larsen, B R

2011-12-01

A novel approach for measuring vertical profiles of HCs and particle number concentrations was described and applied in the low troposphere over Milan (Italy) during typical spring and summer days. Particle profiles yielded nearly homogeneous concentrations below the mixing height, with level-to-ground concentration ratios of 92-97%, while HCs showed a more pronounced decrease (74-95%). Vertical mixing and photochemical loss of HCs were demonstrated to cause these gradients. Much lower concentrations were observed for the profiles above the mixing height, where the HC mixtures showed also a different composition, which was partially explained by the horizontal advection of air with HC sources different to those prevailing at the site. The application of pseudo-first order kinetics for reactions between HCs and the hydroxyl radical allowed for the estimation of the vertical mixing time scale in the order of 100 ± 20 min. Copyright © 2011 Elsevier Ltd. All rights reserved.

Vertical distribution of hydrocarbons in the low troposphere below and above the mixing height: Tethered balloon measurements in Milan, Italy

Energy Technology Data Exchange (ETDEWEB)

Sangiorgi, G., E-mail: giorgia.sangiorgi1@unimib.it [POLARIS Research Centre, Department of Environmental Sciences, University of Milano-Bicocca, piazza della Scienza 1, 20126 Milano (Italy); Ferrero, L.; Perrone, M.G.; Bolzacchini, E. [POLARIS Research Centre, Department of Environmental Sciences, University of Milano-Bicocca, piazza della Scienza 1, 20126 Milano (Italy); Duane, M. [Institute for Environment and Sustainability, EU Joint Research Centre Ispra, 21020 Ispra, Varese (Italy); Larsen, B.R. [Institute for Health and Consumer Protection, EU Joint Research Centre Ispra, 21020 Ispra, Varese (Italy)

2011-12-15

A novel approach for measuring vertical profiles of HCs and particle number concentrations was described and applied in the low troposphere over Milan (Italy) during typical spring and summer days. Particle profiles yielded nearly homogeneous concentrations below the mixing height, with level-to-ground concentration ratios of 92-97%, while HCs showed a more pronounced decrease (74-95%). Vertical mixing and photochemical loss of HCs were demonstrated to cause these gradients. Much lower concentrations were observed for the profiles above the mixing height, where the HC mixtures showed also a different composition, which was partially explained by the horizontal advection of air with HC sources different to those prevailing at the site. The application of pseudo-first order kinetics for reactions between HCs and the hydroxyl radical allowed for the estimation of the vertical mixing time scale in the order of 100 {+-} 20 min. - Graphical abstract: Display Omitted Highlights: > Experimental vertical profiles of HCs and particle concentration by tethered balloon. > Effect of mixing height on the vertical distribution of HCs and particles. > Effect of tropospheric reactivity on vertical profiles of HCs. > Pseudo-first order kinetic reaction of HCs in convective systems. - Vertical transport and photochemical loss of HCs below and above the mixing height were studied by means of a novel and simple approach.

Effect of harvest time on fermentation profiles of maize ensiled in laboratory silos and determination of drying losses at 60°C

DEFF Research Database (Denmark)

Nielsen, Tina Skau; Kristensen, Niels Bastian; Weisbjerg, Martin Riis

2007-01-01

The objectives were to investigate the effect of premature ensiling of maize on alcohol fermentation in laboratory silos and the loss of fermentation products and glucose in silage following drying at 60°C for 48 h. During four consecutive weeks maize was harvested and ensiled for 60 days in vacuum-sealed...

Prediction Model of Mechanical Extending Limits in Horizontal Drilling and Design Methods of Tubular Strings to Improve Limits

Directory of Open Access Journals (Sweden)

Wenjun Huang

2017-01-01

Full Text Available Mechanical extending limit in horizontal drilling means the maximum horizontal extending length of a horizontal well under certain ground and down-hole mechanical constraint conditions. Around this concept, the constrained optimization model of mechanical extending limits is built and simplified analytical results for pick-up and slack-off operations are deduced. The horizontal extending limits for kinds of tubular strings under different drilling parameters are calculated and drawn. To improve extending limits, an optimal design model of drill strings is built and applied to a case study. The results indicate that horizontal extending limits are underestimated a lot when the effects of friction force on critical helical buckling loads are neglected. Horizontal extending limits firstly increase and tend to stable values with vertical depths. Horizontal extending limits increase faster but finally become smaller with the increase of horizontal pushing forces for tubular strings of smaller modulus-weight ratio. Sliding slack-off is the main limit operation and high axial friction is the main constraint factor constraining horizontal extending limits. A sophisticated installation of multiple tubular strings can greatly inhibit helical buckling and increase horizontal extending limits. The optimal design model is called only once to obtain design results, which greatly increases the calculation efficiency.

Discharge flow of a granular media from a silo: effect of the packing fraction and of the hopper angle

Science.gov (United States)

Benyamine, Mebirika; Aussillous, Pascale; Dalloz-Dubrujeaud, Blanche

2017-06-01

Silos are widely used in the industry. While empirical predictions of the flow rate, based on scaling laws, have existed for more than a century (Hagen 1852, translated in [1] - Beverloo et al. [2]), recent advances have be made on the understanding of the control parameters of the flow. In particular, using continuous modeling together with a mu(I) granular rheology seem to be successful in predicting the flow rate for large numbers of beads at the aperture (Staron et al.[3], [4]). Moreover Janda et al.[5] have shown that the packing fraction at the outlet plays an important role when the number of beads at the apeture decreases. Based on these considerations, we have studied experimentally the discharge flow of a granular media from a rectangular silo. We have varied two main parameters: the angle of the hopper, and the bulk packing fraction of the granular material by using bidisperse mixtures. We propose a simple physical model to describe the effect of these parameters, considering a continuous granular media with a dilatancy law at the outlet. This model predicts well the dependance of the flow rate on the hopper angle as well as the dependance of the flow rate on the fine mass fraction of a bidisperse mixture.

Infrasonic induced ground motions

Science.gov (United States)

Lin, Ting-Li

On January 28, 2004, the CERI seismic network recorded seismic signals generated by an unknown source. Our conclusion is that the acoustic waves were initiated by an explosive source near the ground surface. The meteorological temperature and effective sound speed profiles suggested existence of an efficient near-surface waveguide that allowed the acoustic disturbance to propagate to large distances. An explosion occurring in an area of forest and farms would have limited the number of eyewitnesses. Resolution of the source might be possible by experiment or by detailed analysis of the ground motion data. A seismo-acoustic array was built to investigate thunder-induced ground motions. Two thunder events with similar N-wave waveforms but different horizontal slownesses are chosen to evaluate the credibility of using thunder as a seismic source. These impulsive acoustic waves excited P and S reverberations in the near surface that depend on both the incident wave horizontal slowness and the velocity structure in the upper 30 meters. Nineteen thunder events were chosen to further investigate the seismo-acoustic coupling. The consistent incident slowness differences between acoustic pressure and ground motions suggest that ground reverberations were first initiated somewhat away from the array. Acoustic and seismic signals were used to generate the time-domain transfer function through the deconvolution technique. Possible non-linear interaction for acoustic propagation into the soil at the surface was observed. The reverse radial initial motions suggest a low Poisson's ratio for the near-surface layer. The acoustic-to-seismic transfer functions show a consistent reverberation series of the Rayleigh wave type, which has a systematic dispersion relation to incident slownesses inferred from the seismic ground velocity. Air-coupled Rayleigh wave dispersion was used to quantitatively constrain the near-surface site structure with constraints afforded by near-surface body

Polarimetric scattering model for estimation of above ground biomass of multilayer vegetation using ALOS-PALSAR quad-pol data

Science.gov (United States)

Sai Bharadwaj, P.; Kumar, Shashi; Kushwaha, S. P. S.; Bijker, Wietske

Forests are important biomes covering a major part of the vegetation on the Earth, and as such account for seventy percent of the carbon present in living beings. The value of a forest's above ground biomass (AGB) is considered as an important parameter for the estimation of global carbon content. In the present study, the quad-pol ALOS-PALSAR data was used for the estimation of AGB for the Dudhwa National Park, India. For this purpose, polarimetric decomposition components and an Extended Water Cloud Model (EWCM) were used. The PolSAR data orientation angle shifts were compensated for before the polarimetric decomposition. The scattering components obtained from the polarimetric decomposition were used in the Water Cloud Model (WCM). The WCM was extended for higher order interactions like double bounce scattering. The parameters of the EWCM were retrieved using the field measurements and the decomposition components. Finally, the relationship between the estimated AGB and measured AGB was assessed. The coefficient of determination (R2) and root mean square error (RMSE) were 0.4341 and 119 t/ha respectively.

Mud pressure simulation on large horizontal directional drilling

Energy Technology Data Exchange (ETDEWEB)

Placido, Rafael R.; Avesani Neto, Jose O.; Martins, Pedro R.R.; Rocha, Ronaldo [Instituto de Pesquisas Tecnologicas do Estado de Sao Paulo (IPT), Sao Paulo, SP (Brazil)

2009-07-01

Horizontal Directional Drilling (HDD) is being extensively used in Brazil for installation of oil and gas pipelines. This trenchless technology is currently used in crossings of water bodies, environmental sensitive areas, densely populated areas, areas prone to mass movement and anywhere the traditional technology is not suitable because of the risks. One of the unwanted effects of HDD is collapsing of the soil surrounding the bore-hole, leading to loss of fluid. This can result in problems such as reducing the drilling efficiency, ground heave, structures damage, fluid infiltration and other environmental problems. This paper presents four simulations of down-hole fluid pressures which represents two different geometrical characteristics of the drilling and two different soils. The results showed that greater depths are needed in longer drillings to avoid ground rupture. Thus the end section of the drilling often represents the critical stage. (author)

A case study of air quality above an urban roof top vegetable farm

International Nuclear Information System (INIS)

Tong, Zheming; Whitlow, Thomas H.; Landers, Andrew; Flanner, Benjamin

2016-01-01

The effect of elevation and rooftop configuration on local air quality was investigated at the Brooklyn Grange rooftop farm during a short-term observational campaign. Using multiple particle counters and sonic anemometers deployed along vertical gradients, we found that PM_2_._5 concentration decayed with height above the street. Samples adjacent to the street had the highest average PM_2_._5 concentration and frequent stochastic spikes above background. Rooftop observations 26 m above ground showed 7–33% reductions in average PM_2_._5 concentration compared with the curbside and had far fewer spikes. A relationship between the vertical extinction rate of PM_2_._5 and atmospheric stability was found whereby less unstable atmosphere and greater wind shear led to greater PM_2_._5 extinction due to damped vertical motion of air. - Highlights: • PM_2_._5 concentrations on a rooftop farm were 7–33% lower than at ground level. • Rooftop plantings will remove less pollution due to the less steep concentration gradient. • Vegetables are exposed to less vehicular pollution on roofs than that at ground level. - PM_2_._5 concentrations on a rooftop farm were 7–33% below those at ground level, and the vertical extinction rate of PM_2_._5 varied with the atmospheric stability, and a perimeter wall was the dominant factor governing rooftop boundary layer thickness.

A study on the characteristics of strong ground motions in southern Korea

International Nuclear Information System (INIS)

Bang, Chang Eob; Lee, Kie Hwa; Kang, Tae Seob

2001-12-01

Ground motion characteristics in southern Korea are analyzed such as the variations of ground motion durations depending on the hypocentral distance, the earthquake magnitude and the frequency contents of the motion, and the predominant frequency of the maximum ground motion, the ratio of the horizontal to the vertical component amplitudes, the frequency dependence of the Coda Q values, the local distribution of Lg Q values using recorded data sets

A study on the characteristics of strong ground motions in southern Korea

Energy Technology Data Exchange (ETDEWEB)

Bang, Chang Eob; Lee, Kie Hwa; Kang, Tae Seob [Seoul National Univ., Seoul (Korea, Republic of)

2001-12-15

Ground motion characteristics in southern Korea are analyzed such as the variations of ground motion durations depending on the hypocentral distance, the earthquake magnitude and the frequency contents of the motion, and the predominant frequency of the maximum ground motion, the ratio of the horizontal to the vertical component amplitudes, the frequency dependence of the Coda Q values, the local distribution of Lg Q values using recorded data sets.

Measurement of horizontal air showers with the Auger Engineering Radio Array

Science.gov (United States)

Kambeitz, Olga

2017-03-01

The Auger Engineering Radio Array (AERA), at the Pierre Auger Observatory in Argentina, measures the radio emission of extensive air showers in the 30-80 MHz frequency range. AERA consists of more than 150 antenna stations distributed over 17 km2. Together with the Auger surface detector, the fluorescence detector and the underground muon detector (AMIGA), AERA is able to measure cosmic rays with energies above 1017 eV in a hybrid detection mode. AERA is optimized for the detection of air showers up to 60° zenith angle, however, using the reconstruction of horizontal air showers with the Auger surface array, very inclined showers can also be measured. In this contribution an analysis of the AERA data in the zenith angle range from 62° to 80° will be presented. CoREAS simulations predict radio emission footprints of several km2 for horizontal air showers, which are now confirmed by AERA measurements. This can lead to radio-based composition measurements and energy determination of horizontal showers in the future and the radio detection of neutrino induced showers is possible.

Gravity-driven granular flow in a silo: Characterizing local forces and rearrangements

Directory of Open Access Journals (Sweden)

Thackray Emma

2017-01-01

Full Text Available While the gravity-driven flow of a granular material in a silo geometry can be modeled by the Beverloo equation, the mesoscale-level particle rearrangements and interactions that drive this flow are not wellunderstood. We have constructed a quasi-two-dimensional system of bidisperse, millimeter-scale disks with photoelastic properties that make force networks within the material visible. The system is contained in an acrylic box with an adjustable bottom opening. We can approach the clogging transition by adjusting this opening. By placing the system between cross-polarizers, we can obtain high-speed video of this system during flow, and extract intensity signals that can be used to identify and quantify localized, otherwise indeterminate forces. We can simultaneously track individual particle motions, which can be used to identify shear transformation zones in the system. In this paper, we present our results thus far.

Strong ground motion in the Kathmandu Valley during the 2015 Gorkha, Nepal, earthquake

Science.gov (United States)

Takai, Nobuo; Shigefuji, Michiko; Rajaure, Sudhir; Bijukchhen, Subeg; Ichiyanagi, Masayoshi; Dhital, Megh Raj; Sasatani, Tsutomu

2016-01-01

On 25 April 2015, a large earthquake of Mw 7.8 occurred along the Main Himalayan Thrust fault in central Nepal. It was caused by a collision of the Indian Plate beneath the Eurasian Plate. The epicenter was near the Gorkha region, 80 km northwest of Kathmandu, and the rupture propagated toward east from the epicentral region passing through the sediment-filled Kathmandu Valley. This event resulted in over 8000 fatalities, mostly in Kathmandu and the adjacent districts. We succeeded in observing strong ground motions at our four observation sites (one rock site and three sedimentary sites) in the Kathmandu Valley during this devastating earthquake. While the observed peak ground acceleration values were smaller than the predicted ones that were derived from the use of a ground motion prediction equation, the observed peak ground velocity values were slightly larger than the predicted ones. The ground velocities observed at the rock site (KTP) showed a simple velocity pulse, resulting in monotonic-step displacements associated with the permanent tectonic offset. The vertical ground velocities observed at the sedimentary sites had the same pulse motions that were observed at the rock site. In contrast, the horizontal ground velocities as well as accelerations observed at three sedimentary sites showed long duration with conspicuous long-period oscillations, due to the valley response. The horizontal valley response was characterized by large amplification (about 10) and prolonged oscillations. However, the predominant period and envelope shape of their oscillations differed from site to site, indicating a complicated basin structure. Finally, on the basis of the velocity response spectra, we show that the horizontal long-period oscillations on the sedimentary sites had enough destructive power to damage high-rise buildings with natural periods of 3 to 5 s.

Advice about the safety of graphite storage silos of Saint Laurent des Eaux facility

International Nuclear Information System (INIS)

2005-01-01

This document is the safety analysis made by the national association of the local commissions of information about nuclear activities (ANCLI), about the safety of graphite storage silos of Saint Laurent des Eaux nuclear facility. The analysis covers: the operation safety and the accident hypothesis, the monitoring of indoor and outdoor contamination in routine situation, the geotechnical characteristics of the site environment, the isotopic inventory and the estimation of radioactivity in routine and accidental situation, the estimation of doses received by the population in accidental situation and the internal emergency plan. After examination of these different points, the scientific committee of the ANCLI considers that a new global evaluation of risks, which integrates more recent exposure data, has to be carried out. (J.S.)

Detection of large above-ground biomass variability in lowland forest ecosystems by airborne LiDAR

Directory of Open Access Journals (Sweden)

J. Jubanski

2013-06-01

Full Text Available Quantification of tropical forest above-ground biomass (AGB over large areas as input for Reduced Emissions from Deforestation and forest Degradation (REDD+ projects and climate change models is challenging. This is the first study which attempts to estimate AGB and its variability across large areas of tropical lowland forests in Central Kalimantan (Indonesia through correlating airborne light detection and ranging (LiDAR to forest inventory data. Two LiDAR height metrics were analysed, and regression models could be improved through the use of LiDAR point densities as input (R2 = 0.88; n = 52. Surveying with a LiDAR point density per square metre of about 4 resulted in the best cost / benefit ratio. We estimated AGB for 600 km of LiDAR tracks and showed that there exists a considerable variability of up to 140% within the same forest type due to varying environmental conditions. Impact from logging operations and the associated AGB losses dating back more than 10 yr could be assessed by LiDAR but not by multispectral satellite imagery. Comparison with a Landsat classification for a 1 million ha study area where AGB values were based on site-specific field inventory data, regional literature estimates, and default values by the Intergovernmental Panel on Climate Change (IPCC showed an overestimation of 43%, 102%, and 137%, respectively. The results show that AGB overestimation may lead to wrong greenhouse gas (GHG emission estimates due to deforestation in climate models. For REDD+ projects this leads to inaccurate carbon stock estimates and consequently to significantly wrong REDD+ based compensation payments.

[Tree above-ground biomass allometries for carbon stocks estimation in the Caribbean mangroves in Colombia].

Science.gov (United States)

Yepes, Adriana; Zapata, Mauricio; Bolivar, Jhoanata; Monsalve, Alejandra; Espinosa, Sandra Milena; Sierra-Correa, Paula Cristina; Sierra, Andrés

2016-06-01

The distribution of carbon in “Blue Carbon” ecosystems such as mangroves is little known, when compared with the highly known terrestrial forests, despite its particular and recognized high productivity and carbon storage capacity. The objective of this study was to analyze the above ground biomass (AGB) of the species Rhizophora mangle and Avicennia germinans from the Marine Protected Area of Distrito de Manejo Integrado (DMI), Cispatá-Tinajones-La Balsa, Caribbean Colombian coast. With official authorization, we harvested and studied 30 individuals of each species, and built allometric models in order to estimate AGB. Our AGB results indicated that the studied mangrove forests of the DMI Colombian Caribbean was of 129.69 ± 20.24 Mg/ha, equivalent to 64.85 ± 10.12 MgC/ha. The DMI has an area of 8 570.9 ha in mangrove forests, and we estimated that the total carbon potential stored was about 555 795.93 Mg C. The equations generated in this study can be considered as an alternative for the assessment of carbon stocks in AGB of mangrove forests in Colombia; as other available AGB allometric models do not discriminate mangrove forests, despite being particular ecosystems. They can be used for analysis at a more detailed scale and are considered useful to determine the carbon storage potential of mangrove forests, as a country alternative to support forest conservation and emission reduction strategies. In general, the potential of carbon storage from Colombian Caribbean mangrove forests is important and could promote the country leadership of the “blue carbon” stored.

Experimental Study on Natural Convection Heat Transfer From two Parallel Horizontal Cylinders in Horizontal Cylindrical Enclosure

Directory of Open Access Journals (Sweden)

Ahmed T. Ahmed

2013-05-01

Full Text Available  An experimental study on natural convection heat transfer from two parallel horizontal cylinders in horizontal cylindrical enclosure was carried out under condition of constant surfaces temperature for two cylinders and cylindrical enclosure. The study included the effect of Rayleigh number, rotation angle that represent the confined angle between the passing horizontal plane in cylindrical enclosure center and passing line in two cylinders centers, and the spaces between two cylinders on their heat loss ability.39An experimental set-up was used for this purpose which consist watercontainer, test section which is formed of plastic cylinder that represent the cylindrical enclosure, and two heating elements which are formed of two copper cylinders with (19 mm in diameters heated internally by electrical sources that represents transfer and heat loss elements through this set-up.      The experiments were done at the range of Rayleigh number between ( , cylinders rotation angle at ( , and spacing ratio at ( .     The study showed that the ability of heat loss from two cylinders is a function of Rayleigh number, cylinders rotation angle, and the spaces between them. This ability is increased by increasing of Rayleigh number and it was showed that this ability reaches maximum value at the first cylinder ( and minimum value at the second cylinder ( at spacing ratio (S/D=3 and rotation angle ( for the first and ( for the second cylinder respectively.      The effective variables on natural convection heat transfer from the above two cylinders are related by two correlating equations, each one explains dimensionless relation of heat transfer from each cylinder that represented by Nusselt number against Rayleigh number, rotation angle, and the spacing ratio between two cylinders. 

Optimal Atmospheric Correction for Above-Ground Forest Biomass Estimation with the ETM+ Remote Sensor.

Science.gov (United States)

Nguyen, Hieu Cong; Jung, Jaehoon; Lee, Jungbin; Choi, Sung-Uk; Hong, Suk-Young; Heo, Joon

2015-07-31

The reflectance of the Earth's surface is significantly influenced by atmospheric conditions such as water vapor content and aerosols. Particularly, the absorption and scattering effects become stronger when the target features are non-bright objects, such as in aqueous or vegetated areas. For any remote-sensing approach, atmospheric correction is thus required to minimize those effects and to convert digital number (DN) values to surface reflectance. The main aim of this study was to test the three most popular atmospheric correction models, namely (1) Dark Object Subtraction (DOS); (2) Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) and (3) the Second Simulation of Satellite Signal in the Solar Spectrum (6S) and compare them with Top of Atmospheric (TOA) reflectance. By using the k-Nearest Neighbor (kNN) algorithm, a series of experiments were conducted for above-ground forest biomass (AGB) estimations of the Gongju and Sejong region of South Korea, in order to check the effectiveness of atmospheric correction methods for Landsat ETM+. Overall, in the forest biomass estimation, the 6S model showed the bestRMSE's, followed by FLAASH, DOS and TOA. In addition, a significant improvement of RMSE by 6S was found with images when the study site had higher total water vapor and temperature levels. Moreover, we also tested the sensitivity of the atmospheric correction methods to each of the Landsat ETM+ bands. The results confirmed that 6S dominates the other methods, especially in the infrared wavelengths covering the pivotal bands for forest applications. Finally, we suggest that the 6S model, integrating water vapor and aerosol optical depth derived from MODIS products, is better suited for AGB estimation based on optical remote-sensing data, especially when using satellite images acquired in the summer during full canopy development.

Heavy crude production from shallow formations: long horizontal wells versus horizontal fractures

Energy Technology Data Exchange (ETDEWEB)

Valko, P.; Economides, M. J. [Texas A and M Univ., TX (United States)

1998-12-31

The feasibility of producing heavy oil from shallow formations using either horizontal wells or short horizontal wells fractured horizontally is demonstrated. The problem of optimum proppant placement is solved in two steps. In step one, the finite productivity performance is considered in general terms showing that the performance is a function of two dimensionless parameters. Following derivation of optimum conditions, the solution is applied to the horizontal fracture consideration. The limiting factor is that to create an effective finite conductivity fracture, the dimensionless fracture conductivity must be on the order of unity, a fracture that is difficult to realize in higher permeability formations. The best candidates for the suggested configuration are shallow or moderate formations, or formations otherwise proven to accept horizontal fractures, and formations with low permeability/viscosity ratio. 7 refs., 2 tabs., 10 figs., 2 appendices.

Storage and discharge of a granular fluid.

Science.gov (United States)

Pacheco-Martinez, Hector; van Gerner, Henk Jan; Ruiz-Suárez, J C

2008-02-01

Experiments and computational simulations are carried out to study the behavior of a granular column in a silo whose walls are able to vibrate horizontally. The column is brought to a steady fluidized state and it behaves similar to a hydrostatic system. We study the dynamics of the granular discharge through openings at the bottom of the silo in order to search for a Torricelli-like behavior. We show that the flow rate scales with the wall induced shear rate, and at high rates, the granular bed indeed discharges similar to a viscous fluid.

RELIABILITY OF KINEMATICS AND KINETICS ASSOCIATED WITH HORIZONTAL SINGLE LEG DROP JUMP ASSESSMENT. A BRIEF REPORT

Directory of Open Access Journals (Sweden)

Markus Stålbom

2007-06-01

Full Text Available Determining the reliability of a unilateral horizontal drop jump for displacement provided the focus for this research. Eighteen male subjects were required to step off a 20cm box and land on a force plate with one leg and thereafter jump for maximal horizontal displacement on two different days. Dependent variables from the jump assessment included mean and peak vertical (V and horizontal (H ground reaction forces (GRF and impulses, horizontal displacement and contact time. The between-trial variability of all kinematic and kinetic measures was less than 7%. The most consistent measure over both trials was the horizontal displacement jumped (1.2 to 1.4% and the most variable were the contact time the first day (6.5% and peak HGRF the second day (4.3%. In all cases there was less variation associated with the second rather than the first day. In terms of test-retest variability the percent changes in the means and coefficient of variations (CVs were all under 10%. The smallest changes in the mean (0.43 %, least variation (< 2.26 % and second highest intraclass correlation co-efficient (ICC = 0.95 were found for horizontal displacement jumped. The highest ICC (0.96 was found for horizontal impulse. Given the reliability of the single leg drop jump, it may offer better prognostic and diagnostic information than that obtained with bilateral vertical jumps

[Distribution of 137Cs, 90Sr and their chemical analogues in the components of an above-ground part of a pine in a quasi-equilibrium condition].

Science.gov (United States)

Mamikhin, S V; Manakhov, D V; Shcheglov, A I

2014-01-01

The additional study of the distribution of radioactive isotopes of caesium and strontium and their chemical analogues in the above-ground components of pine in the remote from the accident period was carried out. The results of the research confirmed the existence of analogy in the distribution of these elements on the components of this type of wood vegetation in the quasi-equilibrium (relatively radionuclides) condition. Also shown is the selective possibility of using the data on the ash content of the components of forest stands of pine and oak as an information analogue.

Horizontal alternating steam drive process for the Orinoco heavy oil belt in eastern Venezuela

Energy Technology Data Exchange (ETDEWEB)

Edgar A. Fernandez R.; Bashbush, J.L. [Schlumberger, Sugar Land, TX (United States)

2008-10-15

Horizontal alternating steam drive (HASD) processes use single horizontal wells that cyclically switch between injection and production phases. The steam chambers generated by the wells are laterally driven by the pressure differentials created by adjacent producers to form a sweeping front between the wells. This feasibility study assessed the use of HASD processes at a heavy oil reservoir in Venezuela. The study used numerical simulations from a representative reservoir with a 5-horizontal well array to asses the HASD recovery technique under various scenarios. Sensitivity analyses were also conducted to consider the positioning of the horizontal well placement in the reservoir column; different injection sequences; variations in the duration of injection cycles; injection rates; and the lengths of the horizontal reach of the wells. Results of the study suggested that HASD is a suitable alternative for reservoirs with sands in the 20 foot to 50 foot thickness range. HASD achieved average recovery factors of above 20 per cent over a 15 year period, and required fewer wells than steam assisted gravity drainage (SAGD) processes. It was concluded that the wells must be designed to consider the additional thermal stresses resulting the repeated injection and production cycles associated with HASD processes. The 6 refs., 2 tabs., 16 figs.

Vertical distribution of hydrocarbons in the low troposphere below and above the mixing height: Tethered balloon measurements in Milan, Italy

International Nuclear Information System (INIS)

Sangiorgi, G.; Ferrero, L.; Perrone, M.G.; Bolzacchini, E.; Duane, M.; Larsen, B.R.

2011-01-01

A novel approach for measuring vertical profiles of HCs and particle number concentrations was described and applied in the low troposphere over Milan (Italy) during typical spring and summer days. Particle profiles yielded nearly homogeneous concentrations below the mixing height, with level-to-ground concentration ratios of 92-97%, while HCs showed a more pronounced decrease (74-95%). Vertical mixing and photochemical loss of HCs were demonstrated to cause these gradients. Much lower concentrations were observed for the profiles above the mixing height, where the HC mixtures showed also a different composition, which was partially explained by the horizontal advection of air with HC sources different to those prevailing at the site. The application of pseudo-first order kinetics for reactions between HCs and the hydroxyl radical allowed for the estimation of the vertical mixing time scale in the order of 100 ± 20 min. - Graphical abstract: Display Omitted Highlights: → Experimental vertical profiles of HCs and particle concentration by tethered balloon. → Effect of mixing height on the vertical distribution of HCs and particles. → Effect of tropospheric reactivity on vertical profiles of HCs. → Pseudo-first order kinetic reaction of HCs in convective systems. - Vertical transport and photochemical loss of HCs below and above the mixing height were studied by means of a novel and simple approach.

Kinetic Analysis of Horizontal Plyometric Exercise Intensity.

Science.gov (United States)

Kossow, Andrew J; Ebben, William P

2018-05-01

Kossow, AJ, DeChiara, TG, Neahous, SM, and Ebben, WP. Kinetic analysis of horizontal plyometric exercise intensity. J Strength Cond Res 32(5): 1222-1229, 2018-Plyometric exercises are frequently performed as part of a strength and conditioning program. Most studies assessed the kinetics of plyometric exercises primarily performed in the vertical plane. The purpose of this study was to evaluate the multiplanar kinetic characteristics of a variety of plyometric exercises, which have a significant horizontal component. This study also sought to assess sex differences in the intensity progression of these exercises. Ten men and 10 women served as subjects. The subjects performed a variety of plyometric exercises including the double-leg hop, standing long jump, single-leg standing long jump, bounding, skipping, power skipping, cone hops, and 45.72-cm hurdle hops. Subjects also performed the countermovement jump for comparison. All plyometric exercises were evaluated using a force platform. Dependent variables included the landing rate of force development and landing ground reaction forces for each exercise in the vertical, frontal, and sagittal planes. A 2-way mixed analysis of variance with repeated-measures for plyometric exercise type demonstrated main effects for exercise type for all dependent variables (p ≤ 0.001). There was no significant interaction between plyometric exercise type and sex for any of the variable assessed. Bonferroni-adjusted pairwise comparisons identified a number of differences between the plyometric exercises for the dependent variables assessed (p ≤ 0.05). These findings should be used to guide practitioners in the progression of plyometric exercise intensity, and thus program design, for those who require significant horizontal power in their sport.

Measurement of the solar ultraviolet radiation at ground level in Bangi, Malaysia

Energy Technology Data Exchange (ETDEWEB)

Aljawi, Ohoud; Gopir, Geri; Duay, Abdul Basit [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia. ohoud-aljawi@hotmail.com (Malaysia)

2015-04-24

Understanding the amount of ultraviolet (UV) radiation received by human, plant, and animal organisms near the earth’s surface is important to a wide range of fields such as cancer research, agriculture and forestry. The solar ultraviolet spectral irradiance at ground level was measured using the Avantes spectrometer for the period of January to March 2014 at Bangi (2°55´N, 101°46´E, 50 m above sea level) in Malaysia. These data were used to estimate the diurnal variation of UV irradiance (300 – 400 nm). The maximum irradiance of UV radiation was 45 W m{sup −2} on horizontal surface. The maximum irradiance of UV received in the local noon time, and the minimum values of UV irradiance was received in the local morning time. It is found a bigger value of UV radiation was observed on clear sky in January. The estimation of daily flux average of UV irradiance was (921± 91) kJ m{sup −2}.

Ventilation system design for control of radioactive airborne particulates during the decontamination and dismantlement (D&D) of the plant one ore silos

Energy Technology Data Exchange (ETDEWEB)

Williams, J.E. III [Parsons Environmental Services, Inc., Fairfield, OH (United States)

1995-02-01

The Fernald facility is a 1,050-acre site located in southwest Ohio. In July 1989, production was discontinued. The Fernald site has completed its site wide Remedial Investigation/Feasibility Study (RI/FS). In the RI/FS, a variety of response actions where identified for various Operable Unit (OU) area at the FEMP. Of the many response actions in progress at the FEMP, removal action No.17 (in OU-3), known as the Decontamination & Dismantlement (D&D) of the Plant One Ore Silos, exemplifies a state of the art nuclear air cleaning system. Constructed in 1953, Plant 1 was the Sampling Plant for the FEMP site and the receiving point for incoming ores and residues to be processed for the production of uranium metal. The contents were removed except for small amounts of residue. The objective of the removal action is to mitigate the potential for release of contaminants or potential hazards presented by the Plant One Ore Silos until total remediation of the OU-3 area is performed. All D&D work activity is controlled to prevent the release of contamination. The work areas are isolated with physical barriers and a ventilated containment system. The containment for the silo structures consists of scaffolding and polyethylene fabric sheeting (area containment). The containment material is flame-retardant and corrosion resistant in compliance with DOE Order 6430.1A. Ventilation air is filtered through portable air cleaning devices equipped with pre-filters and High Efficiency Particulate Air (HEPA) filters and monitored before discharge to the atmosphere. This paper will illustrate the design of the ventilation in compliance with ASME codes AG-1, N509, N510, and DOE order 6430.1A. The materials of construction and design of the ductwork, stack, portable nuclear air cleaning units, and the type of air sampler used will be addressed. Also, this paper will describe the phase approach to dismantlement and ventilation that resulted in reduced costs and waste minimization.

Horizontal wells in subsurface remediation

International Nuclear Information System (INIS)

Losonsky, G.; Beljin, M.S.

1992-01-01

This paper reports on horizontal wells which offer an effective alternative to vertical wells in various environmental remediation technologies. Hydrogeological advantages of horizontal wells over vertical wells include a larger zone of influence, greater screen length, higher specific capacity and lower groundwater screen entrance velocity. Because of these advantages, horizontal wells can reduce treatment time and costs of groundwater recovery (pump-and-treat), in situ groundwater aeration (sparging) and soil gas extraction (vacuum extraction). Horizontal wells are also more effective than vertical wells in landfill leachate collection (under-drains), bioremediation, and horizontal grout injection

Zenith-angle distributions of atmospheric muons above 20 GeV

International Nuclear Information System (INIS)

Decoster, R.J.; Stevenson, M.L.; Breakstone, A.; Flatte, S.M.

1975-01-01

The results of a magnetic-spectrometer experiment at ground level with optical spark chambers, scintillator hodoscope trigger and an air-gap magnet, are reported to given an evaluation of the zenith-angle distribution of the atmospheric muons above 20 GeV. An automatic flying spot digitizer, the Hummingbird, was used

Ground-truth aerosol lidar observations: can the Klett solutions obtained from ground and space be equal for the same aerosol case?

International Nuclear Information System (INIS)

Ansmann, Albert

2006-01-01

Upcoming multiyear satellite lidar aerosol observations need strong support by a worldwide ground-truth lidar network. In this context the question arises as to whether the ground stations can deliver the same results as obtained from space when the Klett formalism is applied to elastic backscatter lidar data for the same aerosol case. This question is investigated based on simulations of observed cases of simple and complex aerosol layering. The results show that the differences between spaceborne and ground-based observations can be as large as20% for the backscatter and extinction coefficients and the optimum estimates of the column lidar ratios. In cases with complex aerosol layering, the application of the two-layer approach can lead to similar results (space, ground) and accurate products provided that horizontally homogeneous aerosol conditions are given

Ground reaction forces during level ground walking with body weight unloading

Science.gov (United States)

Barela, Ana M. F.; de Freitas, Paulo B.; Celestino, Melissa L.; Camargo, Marcela R.; Barela, José A.

2014-01-01

Background: Partial body weight support (BWS) systems have been broadly used with treadmills as a strategy for gait training of individuals with gait impairments. Considering that we usually walk on level ground and that BWS is achieved by altering the load on the plantar surface of the foot, it would be important to investigate some ground reaction force (GRF) parameters in healthy individuals walking on level ground with BWS to better implement rehabilitation protocols for individuals with gait impairments. Objective: To describe the effects of body weight unloading on GRF parameters as healthy young adults walked with BWS on level ground. Method: Eighteen healthy young adults (27±4 years old) walked on a walkway, with two force plates embedded in the middle of it, wearing a harness connected to a BWS system, with 0%, 15%, and 30% BWS. Vertical and horizontal peaks and vertical valley of GRF, weight acceptance and push-off rates, and impulse were calculated and compared across the three experimental conditions. Results: Overall, participants walked more slowly with the BWS system on level ground compared to their normal walking speed. As body weight unloading increased, the magnitude of the GRF forces decreased. Conversely, weight acceptance rate was similar among conditions. Conclusions: Different amounts of body weight unloading promote different outputs of GRF parameters, even with the same mean walk speed. The only parameter that was similar among the three experimental conditions was the weight acceptance rate. PMID:25590450

Ground reaction forces during level ground walking with body weight unloading

Directory of Open Access Journals (Sweden)

Ana M. F. Barela

2014-12-01

Full Text Available Background: Partial body weight support (BWS systems have been broadly used with treadmills as a strategy for gait training of individuals with gait impairments. Considering that we usually walk on level ground and that BWS is achieved by altering the load on the plantar surface of the foot, it would be important to investigate some ground reaction force (GRF parameters in healthy individuals walking on level ground with BWS to better implement rehabilitation protocols for individuals with gait impairments. Objective: To describe the effects of body weight unloading on GRF parameters as healthy young adults walked with BWS on level ground. Method: Eighteen healthy young adults (27±4 years old walked on a walkway, with two force plates embedded in the middle of it, wearing a harness connected to a BWS system, with 0%, 15%, and 30% BWS. Vertical and horizontal peaks and vertical valley of GRF, weight acceptance and push-off rates, and impulse were calculated and compared across the three experimental conditions. Results: Overall, participants walked more slowly with the BWS system on level ground compared to their normal walking speed. As body weight unloading increased, the magnitude of the GRF forces decreased. Conversely, weight acceptance rate was similar among conditions. Conclusions: Different amounts of body weight unloading promote different outputs of GRF parameters, even with the same mean walk speed. The only parameter that was similar among the three experimental conditions was the weight acceptance rate.

The successful use of transverse hydraulic fractures from horizontal wellbores

Energy Technology Data Exchange (ETDEWEB)

Crosby, D. G.; Yang, Z.; Rahman, S. S. [New South Wales Univ., NSW (Australia)

1998-12-31

Since a significant proportion of the world`s recoverable hydrocarbon resources exist in reservoirs possessing permeabilities of less than one milli-Darcy (mD), some form of permeability enhancement or stimulation is necessary if the hydrocarbons are to be exploited economically. Multi-stage, transversely fractured horizontal wellbores are shown to have the potential to greatly increase production from low permeability formations. To overcome the problems caused by near-wellbore tortuosity, common to wells with multiple fracturing from the same perforated interval, a criterion was devised which predicts the wellbore pressures to initiate secondary multiple transverse hydraulic fractures in close proximity to primary fractures. The criterion, confirmed by laboratory experiments, demonstrates that transversely fractured horizontal wellbores have limited capacities to resist the initiation of multiple fractures from adjacent perforations. This characteristic can be used in designing hydraulic fracture treatments to establish injection pressure limits or threshold pressures, above which additional multiple fractures will initiate and propagate from the wellbore. 23 refs., 1 tab., 10 figs.

Ultraviolet spectra of field horizontal-branch A-type stars. II

International Nuclear Information System (INIS)

Philip, A.G.D.; Hayes, D.S.; Adelman, S.J.

1990-01-01

The spectra of six additional A-type stars have been obtained at low resolution between 1200 and 1900 A with the IUE. The energy distributions of four of the stars match that of the field horizontal branch (FHB) distribution in Huenemoerder et al. (1984) while those of the other two do not. Three of the FHB stars fall above a line in the C(19 - V)0 vs. (b-y)0 diagram; however, HD 60825 is anomalously blue for its C(19 - V) color. 7 refs

Hypersonic ground test capabilities for T and E testing above mach 8 ''a case where S and T meets T and E''

International Nuclear Information System (INIS)

Constantino, M; Miles, R; Brown, G; Laster, M; Nelson, G

1999-01-01

Simulation of hypersonic flight in ground test and evaluation (T and E) facilities is a challenging and formidable task, especially to fully duplicate the flight environment above approximately Mach 8 for most all hypersonic flight systems that have been developed, conceived, or envisioned. Basically, and for many years, the enabling technology to build such a ground test wind tunnel facility has been severely limited in the area of high-temperature, high-strength materials and thermal protection approaches. To circumvent the problems, various approaches have been used, including partial simulation and use of similarity laws and reduced test time. These approaches often are not satisfactory, i.e. operability and durability testing for air-breathing propulsion development and thermal protection development of many flight systems. Thus, there is a strong need for science and technology (S and T) community involvement in technology development to address these problems. This paper discusses a specific case where this need exists and where significant S and T involvement has made and continues to make significant contributions. The case discussed will be an Air Force research program currently underway to develop enabling technologies for a Mach 8-15 hypersonic true temperature wind tunnel with relatively long run time. The research is based on a concept proposed by princeton University using radiant or beamed energy into the supersonic nozzle flow

Seismic behavior of a low-rise horizontal cylindrical tank

Science.gov (United States)

Fiore, Alessandra; Rago, Carlo; Vanzi, Ivo; Greco, Rita; Briseghella, Bruno

2018-05-01

Cylindrical storage tanks are widely used for various types of liquids, including hazardous contents, thus requiring suitable and careful design for seismic actions. The study herein presented deals with the dynamic analysis of a ground-based horizontal cylindrical tank containing butane and with its safety verification. The analyses are based on a detailed finite element (FE) model; a simplified one-degree-of-freedom idealization is also set up and used for verification of the FE results. Particular attention is paid to sloshing and asynchronous seismic input effects. Sloshing effects are investigated according to the current literature state of the art. An efficient methodology based on an "impulsive-convective" decomposition of the container-fluid motion is adopted for the calculation of the seismic force. The effects of asynchronous ground motion are studied by suitable pseudo-static analyses. Comparison between seismic action effects, obtained with and without consideration of sloshing and asynchronous seismic input, shows a rather important influence of these conditions on the final results.

IMPROVED ALGORITHM FOR CALCULATING COMPLEX NON-EQUIPOTENTIAL GROUNDING DEVICES OF ELECTRICAL INSTALLATIONS TAKING INTO ACCOUNT CONDUCTIVITY OF NATURAL GROUNDINGS

Directory of Open Access Journals (Sweden)

K. A. Starkov

2017-08-01

Full Text Available Purpose. The method of natural concentrated groundings substitution by the set of electrodes taking them into account in the algorithm of electric characteristics calculation for complicated grounding connections of electric installation is offered. An equivalent model as a set of linear electrodes is chosen in accordance with two criteria: leakage resistance and potentials on the ground surface. Methodology. We have applied induced potential method and methods for computing branched electrical circuits with distributed parameters. Results. We have obtained the algorithm for calculating complex non-equipotential grounding connections, which makes it possible to obtain refined values of the potential distribution in the electric stations and substations with outdoor switchgear. Originality. For the first time, we have taking into account the conductivity of natural concentrated grounds by a set of vertical and horizontal electrodes based on equivalent electrical characteristics applied to a two-layer ground. Practical value. The using of the proposed calculation algorithm in the electric grids of JSC «Kharkivoblenergo» made it possible to determine the values of the potential distribution at short circuit in electrical substation taking into account the influence of the conductivity of natural concentrated groundings.

The influence of cricket fast bowlers' front leg technique on peak ground reaction forces.

Science.gov (United States)

Worthington, Peter; King, Mark; Ranson, Craig

2013-01-01

High ground reaction forces during the front foot contact phase of the bowling action are believed to be a major contributor to the high prevalence of lumbar stress fractures in fast bowlers. This study aimed to investigate the influence of front leg technique on peak ground reaction forces during the delivery stride. Three-dimensional kinematic data and ground reaction forces during the front foot contact phase were captured for 20 elite male fast bowlers. Eight kinematic parameters were determined for each performance, describing run-up speed and front leg technique, in addition to peak force and time to peak force in the vertical and horizontal directions. There were substantial variations between bowlers in both peak forces (vertical 6.7 ± 1.4 body weights; horizontal (braking) 4.5 ± 0.8 body weights) and times to peak force (vertical 0.03 ± 0.01 s; horizontal 0.03 ± 0.01 s). These differences were found to be linked to the orientation of the front leg at the instant of front foot contact. In particular, a larger plant angle and a heel strike technique were associated with lower peak forces and longer times to peak force during the front foot contact phase, which may help reduce the likelihood of lower back injuries.

Estimating Above-Ground Biomass in Sub-Tropical Buffer Zone Community Forests, Nepal, Using Sentinel 2 Data

Directory of Open Access Journals (Sweden)

Santa Pandit

2018-04-01

Full Text Available Accurate assessment of above-ground biomass (AGB is important for the sustainable management of forests, especially buffer zone (areas within the protected area, where restrictions are placed upon resource use and special measure are undertaken to intensify the conservation value of protected area areas with a high dependence on forest products. This study presents a new AGB estimation method and demonstrates the potential of medium-resolution Sentinel-2 Multi-Spectral Instrument (MSI data application as an alternative to hyperspectral data in inaccessible regions. Sentinel-2 performance was evaluated for a buffer zone community forest in Parsa National Park, Nepal, using field-based AGB as a dependent variable, as well as spectral band values and spectral-derived vegetation indices as independent variables in the Random Forest (RF algorithm. The 10-fold cross-validation was used to evaluate model effectiveness. The effect of the input variable number on AGB prediction was also investigated. The model using all extracted spectral information plus all derived spectral vegetation indices provided better AGB estimates (R2 = 0.81 and RMSE = 25.57 t ha−1. Incorporating the optimal subset of key variables did not improve model variance but reduced the error slightly. This result is explained by the technically-advanced nature of Sentinel-2, which includes fine spatial resolution (10, 20 m and strategically-positioned bands (red-edge, conducted in flat topography with an advanced machine learning algorithm. However, assessing its transferability to other forest types with varying altitude would enable future performance and interpretability assessments of Sentinel-2.

Applicability of petroleum horizontal drilling technology to hazardous waste site characterization and remediation

International Nuclear Information System (INIS)

Goranson, C.

1992-09-01

Horizontal wells have the potential to become an important tool for use in characterization, remediation and monitoring operations at hazardous waste disposal, chemical manufacturing, refining and other sites where subsurface pollution may develop from operations or spills. Subsurface pollution of groundwater aquifers can occur at these sites by leakage of surface disposal ponds, surface storage tanks, underground storage tanks (UST), subsurface pipelines or leakage from surface operations. Characterization and remediation of aquifers at or near these sites requires drilling operations that are typically shallow, less than 500-feet in depth. Due to the shallow nature of polluted aquifers, waste site subsurface geologic formations frequently consist of unconsolidated materials. Fractured, jointed and/or layered high compressive strength formations or compacted caliche type formations can also be encountered. Some formations are unsaturated and have pore spaces that are only partially filled with water. Completely saturated underpressured aquifers may be encountered in areas where the static ground water levels are well below the ground surface. Each of these subsurface conditions can complicate the drilling and completion of wells needed for monitoring, characterization and remediation activities. This report describes some of the equipment that is available from petroleum drilling operations that has direct application to groundwater characterization and remediation activities. A brief discussion of petroleum directional and horizontal well drilling methodologies is given to allow the reader to gain an understanding of the equipment needed to drill and complete horizontal wells. Equipment used in river crossing drilling technology is also discussed. The final portion of this report is a description of the drilling equipment available and how it can be applied to groundwater characterization and remediation activities

Safety assessment for the above ground storage of Cadmium Safety and Control Rods at the Solid Waste Management Facility

International Nuclear Information System (INIS)

Shaw, K.W.

1993-11-01

The mission of the Savannah River Site is changing from radioisotope production to waste management and environmental restoration. As such, Reactor Engineering has recently developed a plan to transfer the safety and control rods from the C, K, L, and P reactor disassembly basin areas to the Transuranic (TRU) Waste Storage Pads for long-term, retrievable storage. The TRU pads are located within the Solid Waste Management Facilities at the Savannah River Site. An Unreviewed Safety Question (USQ) Safety Evaluation has been performed for the proposed disassembly basin operations phase of the Cadmium Safety and Control Rod Project. The USQ screening identified a required change to the authorization basis; however, the Proposed Activity does not involve a positive USQ Safety Evaluation. A Hazard Assessment for the Cadmium Safety and Control Rod Project determined that the above-ground storage of the cadmium rods results in no change in hazard level at the TRU pads. A Safety Assessment that specifically addresses the storage (at the TRU pads) phase of the Cadmium Safety and Control Rod Project has been performed. Results of the Safety Assessment support the conclusion that a positive USQ is not involved as a result of the Proposed Activity

Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species

Science.gov (United States)

Vannette, Rachel L.; Hunter, Mark D.; Rasmann, Sergio

2013-01-01

Below-ground (BG) symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above- (AG) and BG herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF) on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed)—which all produce toxic cardenolides—with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in AG and BG plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and defense. PMID:24065971

Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species.

Science.gov (United States)

Vannette, Rachel L; Hunter, Mark D; Rasmann, Sergio

2013-01-01

Below-ground (BG) symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above- (AG) and BG herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF) on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed)-which all produce toxic cardenolides-with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in AG and BG plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and defense.

Control of quality and silo storage of sunflower seeds using near infrared technology

Energy Technology Data Exchange (ETDEWEB)

Gonzalez-Martin, I.; Vilaescusa-Garcia, V.; Lopez-Gonzalez, F.; Oiz-Jimenez, C.; Lobos-Ortega, I. A.; Gordillo, B.; Hernandez-Hierro, J. M.

2013-05-01

This work assesses the application of near infrared spectroscopy technology for the quality control of sunflower seeds direct from farmers and from a storage silo. The results show that the analytical method employing near infrared spectroscopy can be used as a rapid and non-destructive tool for the determination of moisture, fat and high/low oleic acid contents in samples of sunflower seeds. The ranges obtained were comparable to those reported for classic chemical methods, and were between 4.6-21.4% for moisture; 38.4-49.6% for fat, and 60.0-93.1% for oleic acid expressed as percentage of total fatty acids. A stepwise discriminant analysis was performed to determine the most useful wavelengths for classifying sunflower seeds in terms of their (high/low) oleic acid composition. The discriminant model allows the acid contents, with a prediction rate of 90.5% for internal validation and of 89.4% for cross-validation. (Author) 23 refs.

Control of quality and silo storage of sunflower seeds using near infrared technology

International Nuclear Information System (INIS)

Gonzalez-Martin, I.; Vilaescusa-Garcia, V.; Lopez-Gonzalez, F.; Oiz-Jimenez, C.; Lobos-Ortega, I. A.; Gordillo, B.; Hernandez-Hierro, J. M.

2013-01-01

This work assesses the application of near infrared spectroscopy technology for the quality control of sunflower seeds direct from farmers and from a storage silo. The results show that the analytical method employing near infrared spectroscopy can be used as a rapid and non-destructive tool for the determination of moisture, fat and high/low oleic acid contents in samples of sunflower seeds. The ranges obtained were comparable to those reported for classic chemical methods, and were between 4.6-21.4% for moisture; 38.4-49.6% for fat, and 60.0-93.1% for oleic acid expressed as percentage of total fatty acids. A stepwise discriminant analysis was performed to determine the most useful wavelengths for classifying sunflower seeds in terms of their (high/low) oleic acid composition. The discriminant model allows the acid contents, with a prediction rate of 90.5% for internal validation and of 89.4% for cross-validation. (Author) 23 refs.

A Low-Profile and Compact Split-Ring Antenna with Horizontally Polarized Omnidirectional Radiation

Directory of Open Access Journals (Sweden)

Kittima Lertsakwimarn

2015-01-01

Full Text Available This paper presents a low-profile and compact printed antenna having an omnidirectional radiation pattern with horizontal polarization to the ground. The proposed antenna consists of an inner small fed ring, an outer coupled split ring, and a ground plane. The overall dimension of the proposed antenna is 45 mm × 50.5 mm × 11.6 mm (0.138λ0 × 0.155λ0 × 0.036λ0. The −10-dB S11 of the antenna covers the 920-MHz RFID band, and the gain is about 1.45 dBi in the parallel direction to the ground plane. The measured results show good agreements with the simulated results. Furthermore, the reasons for the low-profile structure and the omnidirectional radiation pattern are also discussed.

Full-scale fire experiments on vertical horizontal cable trays

International Nuclear Information System (INIS)

Mangs, J.; Keski-Rahkonen, O.

1997-10-01

Two full-scale fire experiments on PVC cables used in nuclear power plants were carried out, one with cables in vertical position and one with cables in horizontal position. The vertical cable bundle, 3 m high, 300 mm wide and 30 mm thick, was attached to a steel cable ladder. The vertical bundle experiment was carried out in nearly free space with three walls near the cable ladder guiding air flow in order to stabilise flames. The horizontal cable experiment was carried out in a small room with five cable bundles attached to steel cable ladders. Three of the 2 m long cable bundles were located in an array, equally spaced above each other near one long side of the room and two correspondingly near the opposite long side. The vertical cable bundle was ignited with a small propane gas burner beneath the lower edge of the bundle. The horizontal cable bundles were ignited with a small propane burner beneath the lowest bundle in an array of three bundles. Rate of heat release by means of oxygen consumption calorimetry, mass change, CO 2 , CO and smoke production rate and gas, wall and cable surface temperatures were measured as a function of time, as well as time to sprinkler operation and failure of test voltage in cables. Additionally, the minimum rate of heat release needed to ignite the bundle was determined. This paper concentrates on describing and recording the experimental set-up and the data obtained. (orig.)

Vertical and horizontal subsidiarity

Directory of Open Access Journals (Sweden)

Ivan V. Daniluk

2016-02-01

Full Text Available This article makes an attempt to analyze the principle of subsidiarity in its two main manifestations, namely vertical and horizontal, to outline the principles of relations between the state and regions within the vertical subsidiarity, and features a collaboration of the government and civil society within the horizontal subsidiarity. Scientists identify two types, or two levels of the subsidiarity principle: vertical subsidiarity and horizontal subsidiarity. First, vertical subsidiarity (or territorial concerning relations between the state and other levels of subnational government, such as regions and local authorities; second, horizontal subsidiarity (or functional concerns the relationship between state and citizen (and civil society. Vertical subsidiarity expressed in the context of the distribution of administrative responsibilities to the appropriate higher level lower levels relative to the state structure, ie giving more powers to local government. However, state intervention has subsidiary-lower action against local authorities in cases of insolvency last cope on their own, ie higher organisms intervene only if the duties are less authority is insufficient to achieve the goals. Horizontal subsidiarity is within the relationship between power and freedom, and is based on the assumption that the concern for the common good and the needs of common interest community, able to solve community members (as individuals and citizens’ associations and role of government, in accordance horizontal subsidiarity comes to attracting features subsidiarity assistance, programming, coordination and possibly control.

In situ bioremediation using horizontal wells. Innovative technology summary report

International Nuclear Information System (INIS)

1995-04-01

In Situ Bioremediation (ISB) is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation. This process (ISB) involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove Volatile Organic Compounds (VOCs) from the vadose zone concomitant with biodegradation of the VOCs. This process is effective for remediation of soils and ground water contaminated with VOCs both above and below the water table. A full-scale demonstration of ISB was conducted as part of the Savannah River Integrated Demonstration: VOCs in Soils and Ground Water at Nonarid Sites. This demonstration was performed at the Savannah River Site from February 1992 to April 1993

Settlement mechanism of the backfilled ground around nuclear power plant buildings. Part 1. A series of 1G shaking table tests

International Nuclear Information System (INIS)

Ishimaru, Makoto; Kawai, Tadashi

2008-01-01

The large ground settlement locally occurred at the backfilled ground around the Kashiwazaki-Kariwa Nuclear Power Plant buildings during the Niigataken Chuetsu-oki Earthquake in 2007. The purposes of this study are to verify the assumed mechanism of the settlement and to discuss the influence factors on the settlement. For these purposes, we conducted a series of 1G shaking table tests using a rigid structure and sand. In the tests, parameters, which were variously changed, are related to two factors; one is the horizontal ground displacement relative to the structure, the other is the ground strength against the sliding failure. The following results were obtained: (1) All the results showed that the ground settlement sizes near the structure were larger than the ground settlement sizes far from the structure, (2) From the video observed at the ground near the structure, it was found that the settlement locally occurred due to the sliding failure after the ground was separated from the structure, (3) The ground settlement sizes near the structure were large as the horizontal ground displacement sizes were large, and the soil strength arising from fines affected the ground settlement sizes near the structure. (author)

Vertical and horizontal integration of knowledge and skills - a working model.

Science.gov (United States)

Snyman, W D; Kroon, J

2005-02-01

The new integrated outcomes-based curriculum for dentistry was introduced at the University of Pretoria in 1997. The first participants graduated at the end of 2001. Educational principles that underpin the new innovative dental curriculum include vertical and horizontal integration, problem-oriented learning, student-centred learning, a holistic attitude to patient care and the promotion of oral health. The aim of this research project was to develop and assay a model to facilitate vertical integration of knowledge and skills thereby justifying the above mentioned action. The learning methodology proposed for the specific outcome of the Odontology module, namely the diagnosis of dental caries and the design of a primary preventive programme, included problem-solving as the driving force for the facilitation of vertical and horizontal integration, and an instructional design for the integration of the basic knowledge and clinical skills into a single learning programme. The paper describes the methodology of problem-oriented learning as applied in this study together with the detail of the programme. The consensus of those teachers who represent the basic and clinical sciences and who participate in this learning programme is that this model is practical and can assist vertical as well as horizontal integration of knowledge.

Analysis of the D0 Crane Rail as a Support for a Horizontal Lifeline

International Nuclear Information System (INIS)

Cease, H.

2000-01-01

The D-Zero crane rail is analyzed for use as an anchor support for a one person Horizon(trademark) Horizontal Lifeline system that will span the pit area at D-Zero assembly hall. The lifeline will span 75 ft across the pit area, will be located out of the travel of the crane and above the concrete lentil wall. The crane rail is a suitable anchor for a one person Horizon TM Horizontal Lifeline system. The expected stress on the rail is 1,995 psi which has a factor of safety of 5.5 on the allowable stress. The anchor position is located 18 feet away from the concrete lentil wall and out of the travel of the overhead crane.

Improved waterflooding efficiency by horizontal wells

Energy Technology Data Exchange (ETDEWEB)

Popa, C. G. [Petroleum and Gas Univ., Ploesti (Romania); Clipea, M. [SNP Petrom SA, ICPT Campina (Romania)

1998-12-31

The influence of well pattern involving the use of horizontal wells on the overall efficiency of the waterflooding process was analyzed. Three different scenarios were examined: (1) a pattern of using two parallel horizontal wells, one for injection, the other for production, (2) a pattern of one horizontal well for water injection and several vertical wells for production, and (3) a pattern of using vertical wells for injection and one horizontal well for production. In each case, the waterflooding process was simulated using a two phase two dimensional numerical model. Results showed that the pressure loss along the horizontal section had a large influence on the sweep efficiency whether the horizontal well was used for injection or production. Overall, the most successful combination appeared to be using vertical wells for injection and horizontal wells for production. 4 refs., 1 tab., 15 figs.

Specific effects of small doses of 60Co-γ-radiation applied to the seeds before sowing on the yield of silo maize (small and large plot field experiments)

International Nuclear Information System (INIS)

Degner, W.; Schacht, W.; Koepp, R.

1975-01-01

Dry seeds of silo maize were cultivated under outside conditions after fractionated irradiation with low radiation doses. The yields of irradiated and unirradiated seeds were compared. The resistance of irradiated and unirradiated plants and ensilage were also studied and compared. The findings are discussed. (GSE/AK) [de

Model evaluation of seepage from uranium tailings disposal above and below the water table

International Nuclear Information System (INIS)

Nelson, R.W.; Meyer, P.R.; Oberlander, P.L.; Sneider, S.C.; Mayer, D.W.; Reisenauer, A.E.

1983-03-01

Model simulations identify the rate and amount of leachate released to the environment if disposed uranium mill tailings come into contact with ground water or if seepage from tailings reaches ground water. In this study, simulations of disposal above and below the water table, with various methods of leachate control, were compared. Three leachate control methods were used in the comparisons: clay bottom liners; stub-sidewall clay liners; and tailings drains with sumps, with the effluent pumped back from the sumps. The best leachate control for both above and below the water table is a combination of the three methods. The combined methods intercept up to 80% of the leachate volume in pits above the water table and intercept essentially all of the leachate in pits below the water table. Effluent pumping, however, requires continuous energy costs and an alternative method of disposal for the leachate that cannot be reused as makeup water in the mill process. Without the drains or effluent pumping, the clay bottom liners have little advantage in terms of the total volume of leachate lost. The clay liners do reduce the rate of leachate flow to the ground water, but the flow continues for a longer time. The buffering, sorption, and chemical reactions of the leachate passing directly through the liner are also advantages of the liner

Optical Remote Sensing of Electric Fields Above Thunderstorms

Science.gov (United States)

Burns, B. M.; Carlson, B. E.; Lauben, D.; Cohen, M.; Smith, D.; Inan, U. S.

2010-12-01

Measurement of thunderstorm electric fields typically require balloon-borne measurements in the region of interest. Such measurements are cumbersome and provide limited information at a single point. Remote sensing of electric fields by Kerr-effect induced optical polarization changes of background skylight circumvents many of these difficulties and can in principle provide a high-speed movie of electric field behavior. Above-thundercloud 100 kV/m quasi-static electric fields are predicted to produce polarization changes at above the part in one million level that should be detectable at a ground instrument featuring 1 cm2sr geometric factor and 1 kHz bandwidth (though more sensitivity is nonetheless desired). Currently available optical and electronic components may meet these requirements. We review the principles of this measurement and discuss the current status of a field-ready prototype instrument currently in construction.

A Study on the Improvement Effect and Field Applicability of the Deep Soft Ground by Ground Heating Method

Directory of Open Access Journals (Sweden)

Mincheol Park

2018-05-01

Full Text Available The soft ground in coastal areas should be treated when it needs to be used for the sustainably developed of urban or industrial complex constructions. The ground heating method for soft ground improvement was applied in Eastern Europe in the 1960s, but it was not widely used due to economic and environmental problems. The author developed a device for improving soft ground using an electric heating pipe. This paper investigates the improvement effect and field application of deep soft ground by the ground heating method using the electric heating pipe. Ground heating increases the temperature of the deep soft ground and increases the tip resistance of the static electronic piezo-cone penetration test. Additionally, the pressure of the pore water decreases because the pore water is evaporated due to the ground heating. As a result of the experiment, it was verified that there was an improvement in the effect of deep soft ground by the ground heating method. With ground heating for 96 h, the tip resistance was increased by 61% at a point 0.35 m horizontally away from the electric heat pipe, 22% at 0.97 m, and 2% at 1.31 m. As a result of the field test, it was found that there were no problems in the power supply of the diesel generator and the control panel. It was easy to install the electric heating pipes in the deep soft ground. However, due to boring, the ground was disturbed and water vapor was discharged through this gap. To minimize the discharge of water vapor, it is necessary to drive the electric heating pipe.

a Point Cloud Classification Approach Based on Vertical Structures of Ground Objects

Science.gov (United States)

Zhao, Y.; Hu, Q.; Hu, W.

2018-04-01

This paper proposes a novel method for point cloud classification using vertical structural characteristics of ground objects. Since urbanization develops rapidly nowadays, urban ground objects also change frequently. Conventional photogrammetric methods cannot satisfy the requirements of updating the ground objects' information efficiently, so LiDAR (Light Detection and Ranging) technology is employed to accomplish this task. LiDAR data, namely point cloud data, can obtain detailed three-dimensional coordinates of ground objects, but this kind of data is discrete and unorganized. To accomplish ground objects classification with point cloud, we first construct horizontal grids and vertical layers to organize point cloud data, and then calculate vertical characteristics, including density and measures of dispersion, and form characteristic curves for each grids. With the help of PCA processing and K-means algorithm, we analyze the similarities and differences of characteristic curves. Curves that have similar features will be classified into the same class and point cloud correspond to these curves will be classified as well. The whole process is simple but effective, and this approach does not need assistance of other data sources. In this study, point cloud data are classified into three classes, which are vegetation, buildings, and roads. When horizontal grid spacing and vertical layer spacing are 3 m and 1 m respectively, vertical characteristic is set as density, and the number of dimensions after PCA processing is 11, the overall precision of classification result is about 86.31 %. The result can help us quickly understand the distribution of various ground objects.

The effect of diameter on vertical and horizontal flow boiling crisis in a tube cooled by Freon-12

International Nuclear Information System (INIS)

Merilo, M.; Ahmad, S.Y.

1979-03-01

The influence of test section orientation and diameter on flow boiling crisis occurring in tubes has been studied experimentally using Freon-12 as a coolant. At low mass flux the critical heat flux (CHF) was lower in horizontal flow than in vertical. As either the liquid or vapour velocity, or both, were increased the vertical and horizontal CHF results converged. Above a mass flux of 4 Mg.m -2 .s -1 the results were essentially identical. The effect of tube diameter on boiling crisis in general depends crucially on the parameters which are maintained constant when the comparison is made. (author)

Horizontal drilling assessment in Western Canada

International Nuclear Information System (INIS)

Catania, Peter; Wilson, Malcolm

1999-01-01

The first horizontal well was drilled in Saskatchewan in 1987. Since then, the number of horizontal wells drilled has escalated rapidly, averaging approximately 500 per year since 1993. When combined with horizontal wells drilled in Alberta, the major Canadian oil-producing province, the total number drilled in 1995 was 978. This total exceeds the National Energy Board (NEB) projected maximum of 816 wells per year. The NEB projections were based on a break-even point for the drilling of horizontal wells of a return of CDN $285,000 using a discount rate of 15%. This corresponded to a cumulative production from each individual well of some 11,000 m 3 . The introduction of a royalty-free production volume of 12,000 m 3 per horizontal well in Saskatchewan was instrumental in stimulating the rapid expansion in the use of horizontal wells and helping Canada to exceed the forecasted drilling level. Within Saskatchewan, daily production from 1964 active horizontal wells is in excess of 20,000 m 3 . Comparative analysis indicates that the average daily production per well has increased from approximately by 40% with the advent of horizontal wells. In total production terms, provincial production has increased from 11.7 million cubic metres in 1989 to 20.9 million m 3 in 1996. This represents an increase of almost 79% based primarily on the extensive use of horizontal wells. In 1996, horizontal wells produced 36% of the province's oil from 12% of the active wells. In the southeastern producing areas of Saskatchewan, the Williston Basin, declining oil-production has jumped 100%, with horizontal wells accounting for approximately 50% of total regional production. Pay zones in this areas, as in most of the province, tend to be relatively thin, with net pay frequently less that 5 m. The modest investment of some CDN $5 million in government research funding 10 years ago to stimulate the development of horizontal wells, combined with a favourable royalty structure, has been at

Measurements of the spatial distribution of tritium in air above a chronically contaminated surface

International Nuclear Information System (INIS)

Workman, W.J.G.; Davis, P.A.; Wood, M.J.; Barry, P.J.

1993-01-01

Tritium in air (HTO) concentrations were measured over a 13 month period above a surface that is chronically contaminated by tritium-bearing groundwater from a waste management area. The measurements were made using passive diffusion samplers, which were sited at six locations (about 100 m apart) at 0.15, 0.9, and 1.8 m above ground level. The diffusion samplers were compact, sampled at a known rate, and required no external power source. They are ideal for remote locations and require a minimum of effort to collect and analyze the data. HTO-in-air concentration peaked in the summer at 500-1500 Bq.m -3 and decreased in the winter to 1-120 Bq.m -3 . In general, concentration decreased with height above ground level, implying that HTO is being lost from the surface to the atmosphere. The flux of tritium to the atmosphere must, therefore, be taken into account to estimate the tritium mass balance for a contaminated area. (Author) 3 figs., 5 tabs., 10 refs

Adaptive ground implemented phase array

Science.gov (United States)

Spearing, R. E.

1973-01-01

The simulation of an adaptive ground implemented phased array of five antenna elements is reported for a very high frequency system design that is tolerant to the radio frequency interference environment encountered by a tracking data relay satellite. Signals originating from satellites are received by the VHF ring array and both horizontal and vertical polarizations from each of the five elements are multiplexed and transmitted down to ground station. A panel on the transmitting end of the simulation chamber contains up to 10 S-band RFI sources along with the desired signal to simulate the dynamic relationship between user and TDRS. The 10 input channels are summed, and desired and interference signals are separated and corrected until the resultant sum signal-to-interference ratio is maximized. Testing performed with this simulation equipment demonstrates good correlation between predicted and actual results.

Quantifying above- and below-ground growth responses of the western Australian oil mallee, Eucalyptus kochii subsp. plenissima, to contrasting decapitation regimes.

Science.gov (United States)

Wildy, Dan T; Pate, John S

2002-08-01

Resprouting in the oil mallee, Eucalyptus kochii Maiden & Blakely subsp. plenissima Gardner (Brooker), involves generation of new shoots from preformed meristematic foci on the lignotuber. Numbers of such foci escalated from 200 per lignotuber in trees aged 1 year to 3,000 on 4- to 5-year-old trees. Removal of shoot biomass by decapitation 5 cm above ground in summer (February) or spring (October) resulted in initiation of 140-170 new shoots, but approx. 400 shoots were induced to form if crops of new shoots were successively removed until sprouting ceased and rootstocks senesced. Initially, the new shoot biomass of regenerating coppices increased slowly and the root biomass failed to increase appreciably until 1.7-2.5 years after cutting. Newly cut trees showed loss of fine root biomass, and structural roots failed to secondarily thicken to the extent shown by uncut trees. After 2 years, the biomass of shoots of coppiced plants was only one-third that of uncut control trees and shoot:root dry mass ratios of coppiced plants were still low (1.5-2.0) compared with those of the controls (average ratio of 3.1). Spring cutting promoted quicker and greater biomass recovery than summer cutting. Starch in below-ground biomass fell quickly following decapitation and remained low for a 12-18 month period. Utilization of starch reserves in naturally regenerating coppices was estimated to provide only a small proportion of the dry matter accumulated in new shoots. Results are discussed in relation to their impact on coppicing ability of the species under natural conditions or when successively coppiced for shoot biomass production.

Singlet Ground State Magnetism:

DEFF Research Database (Denmark)

Loidl, A.; Knorr, K.; Kjems, Jørgen

1979-01-01

The magneticGamma 1 –Gamma 4 exciton of the singlet ground state system TbP has been studied by inelastic neutron scattering above the antiferromagnetic ordering temperature. Considerable dispersion and a pronounced splitting was found in the [100] and [110] directions. Both the band width...

Stochastic Modeling and Simulation of Near-Fault Ground Motions for Performance-Based Earthquake Engineering

OpenAIRE

Dabaghi, Mayssa

2014-01-01

A comprehensive parameterized stochastic model of near-fault ground motions in two orthogonal horizontal directions is developed. The proposed model uniquely combines several existing and new sub-models to represent major characteristics of recorded near-fault ground motions. These characteristics include near-fault effects of directivity and fling step; temporal and spectral non-stationarity; intensity, duration and frequency content characteristics; directionality of components, as well as ...

Evaluating Generic Pantropical Allometric Models for the Estimation of Above-Ground Biomass in the Teak Plantations of Southern Western Ghats, India

Directory of Open Access Journals (Sweden)

S. Sandeep

2015-09-01

Full Text Available The use of suitable tree biomass allometric equations is crucial for making precise and non- destructive estimation of carbon storage and biomass energy values. The aim of this research was to evaluate the accuracy of the most commonly used pantropical allometric models and site-specific models to estimate the above-ground biomass (AGB in different aged teak plantations of Southern Western Ghats of India. For this purpose, the AGB data measured for 70 trees with diameter >10 cm from different aged teak plantations in Kerala part of Southern Western Ghats following destructive procedure was used. The results show that site specific models based on a single predictor variable diameter at breast height (dbh, though simple, may grossly increase the uncertainty across sites. Hence, a generic model encompassing dbh, height and wood specific gravity with sufficient calibration taking into account different forest types is advised for the tropical forest systems. The study also suggests that the commonly used pantropical models should be evaluated for different ecosystems prior to their application at national or regional scales.

Storage and discharge of a granular fluid

NARCIS (Netherlands)

Pacheco-Martinez, Hector; van Gerner, H.J.; Ruiz-Suarez, J.C.

2008-01-01

Experiments and computational simulations are carried out to study the behavior of a granular column in a silo whose walls are able to vibrate horizontally. The column is brought to a steady fluidized state and it behaves similar to a hydrostatic system. We study the dynamics of the granular

Near-ground tornado-like vortex structure resolved by particle image velocimetry (PIV)

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wei [Iowa State University, Aerospace Engineering Department, Ames, IA (United States); University of Minnesota, Saint Anthony Falls Laboratory, Minneapolis, MN (United States); Sarkar, Partha P. [Iowa State University, Aerospace Engineering Department, Ames, IA (United States)

2012-02-15

The near-ground flow structure of tornadoes is of utmost interest because it determines how and to what extent civil structures could get damaged in tornado events. We simulated tornado-like vortex flow at the swirl ratios of S = 0.03-0.3 (vane angle {theta}{sub v} = 15 -60 ), using a laboratory tornado simulator and investigated the near-ground-vortex structure by particle imaging velocimetry. Complicated near-ground flow was measured in two orthogonal views: horizontal planes at various elevations (z = 11, 26 and 53 mm above the ground) and the meridian plane. We observed two distinct vortex structures: a single-celled vortex at the lowest swirl ratio (S = 0.03, {theta}{sub v} = 15 ) and multiple suction vortices rotating around the primary vortex (two-celled vortex) at higher swirl ratios (S = 0.1-0.3, {theta}{sub v} = 30 -60 ). We quantified the effects of vortex wandering on the mean flow and found that vortex wandering was important and should be taken into account in the low swirl ratio case. The tangential velocity, as the dominant velocity component, has the peak value about three times that of the maximum radial velocity regardless of the swirl ratio. The maximum velocity variance is about twice at the high swirl ratio ({theta}{sub v} = 45 ) that at the low swirl ratio ({theta}{sub v} = 15 ), which is contributed significantly by the multiple small-scale secondary vortices. Here, the results show that not only the intensified mean flow but greatly enhanced turbulence occurs near the surface in the tornado-like vortex flow. The intensified mean flow and enhanced turbulence at the ground level, correlated with the ground-vortex interaction, may cause dramatic damage of the civil structures in tornadoes. This work provides detailed characterization of the tornado-like vortex structure, which has not been fully revealed in previous field studies and laboratory simulations. It would be helpful in improving the understanding of the interaction between the

Study of horizontal-vertical interactive Sway Rocking (SR) model for basemat uplift. Part 2: non-linear response analysis and validation

International Nuclear Information System (INIS)

Momma, T.; Shirahama, K.; Suzuki, K.; Ogihara, M.

1995-01-01

Non-linear earthquake response analyses of a BWR MARK-II type nuclear reactor building are conducted by using a Sway Rocking model (SR model) proposed in Part 1 considering the interaction between horizontal and vertical motion. The results are compared with those of accurate mathematical model using the Green Function method. Horizontal response of the SR model agrees very well with that of the Green Function model. The floor response spectra of induced vertical motions by both methods are also corresponding well in periodic characteristics as well as peak-levels. From these results, it is confirmed that the horizontal-vertical interactive SR model is applicable to non-linear response analyses considering basemat uplift. Based on the comparison of the induced vertical motions due to basemat uplift by both methods, an application limit of the horizontal-vertical interactive SR model is set up at the ground contact ratio of about 50%. (author). 4 refs., 8 figs., 1 tab

New horizontal and vertical mass transfer coefficient equation formulations applied to a refinery data base

International Nuclear Information System (INIS)

Hellums, L.J.; Fine, D.G.; DeCoursey, S.S.; Cronic, K.A.

1984-01-01

The American Petroleum Institute (API) has collected a large tracer data base representing the best field data on atmospheric dispersion performed up to 1982. Twelve of these tracer programs (Hanford 67, Green Glow, Prairie Grass, NRTS, TMI, Ocean Breeze, Dry Gulch, St. Louis, Rancho Seco, Paramount, Karlsruhe, Goodyear) were brought into Phillips Petroleum Company for Gaussian plume formulation using an optimal least squares procedure. The horizontal diffusion and the vertical diffusion were manipulated in an optimal fashion in the Gaussian plume formulation to give a best fit of calculated to experimental (field observations) data important conclusions from the many observations in this work are: 1. Field measured Turner stability when used with Pasquill-Gifford curves does not choose horizontal and vertical dispersion rates representative of true atmospheric turbulence in most cases, 2. Individual stabilities are required rather than assuming one stability for both dispersion rates, and 3. Horizontal diffusion is a function of downwind distance, crosswind distance, and stability for dispersion downwind of building complexes with considerable ground roughness

Evaluation of stability of foundation ground during earthquake, (5)

International Nuclear Information System (INIS)

Nishi, Koh-ichi; Kanatani, Mamoru

1987-01-01

The Central Research Institute of Electric Power Industry advances the research on the method of evaluating foundation grounds from the standpoint of developing in-situ ground survey testing method and the method of evaluating mechanical properties in the studies on the technology for siting nuclear power stations on Quaternary grounds. The newly developed analytical technique on ground stability by the results of the analytical method for equivalent linear response was already reported. In this paper, the analytical method for nonlinear response to investigate into the more detailed behavior of ground due to strong earthquake motion is reported. In particular, the constitutive relation based on elastoplasticity was newly proposed in order to represent the deformation behavior during cyclic loading, and the examples of its application to the response of horizontally leveled sandy ground to earthquake are described. The dialatancy characteristics of soil are constituted by yield function, plastic potential functioin and hardening function. The material constants in proposed constitutive relation are easily determined by laboratory tests. One-dimensional response analysis was conducted, using the constitutive relation. (Kako, I.)

Feed-forward segmentation of figure-ground and assignment of border-ownership.

Directory of Open Access Journals (Sweden)

Hans Supèr

Full Text Available Figure-ground is the segmentation of visual information into objects and their surrounding backgrounds. Two main processes herein are boundary assignment and surface segregation, which rely on the integration of global scene information. Recurrent processing either by intrinsic horizontal connections that connect surrounding neurons or by feedback projections from higher visual areas provide such information, and are considered to be the neural substrate for figure-ground segmentation. On the contrary, a role of feedforward projections in figure-ground segmentation is unknown. To have a better understanding of a role of feedforward connections in figure-ground organization, we constructed a feedforward spiking model using a biologically plausible neuron model. By means of surround inhibition our simple 3-layered model performs figure-ground segmentation and one-sided border-ownership coding. We propose that the visual system uses feed forward suppression for figure-ground segmentation and border-ownership assignment.

Feed-forward segmentation of figure-ground and assignment of border-ownership.

Science.gov (United States)

Supèr, Hans; Romeo, August; Keil, Matthias

2010-05-19

Figure-ground is the segmentation of visual information into objects and their surrounding backgrounds. Two main processes herein are boundary assignment and surface segregation, which rely on the integration of global scene information. Recurrent processing either by intrinsic horizontal connections that connect surrounding neurons or by feedback projections from higher visual areas provide such information, and are considered to be the neural substrate for figure-ground segmentation. On the contrary, a role of feedforward projections in figure-ground segmentation is unknown. To have a better understanding of a role of feedforward connections in figure-ground organization, we constructed a feedforward spiking model using a biologically plausible neuron model. By means of surround inhibition our simple 3-layered model performs figure-ground segmentation and one-sided border-ownership coding. We propose that the visual system uses feed forward suppression for figure-ground segmentation and border-ownership assignment.

Evaluation of a ground thermal energy storage system for heating and cooling of an existing dwelling

Energy Technology Data Exchange (ETDEWEB)

Leong, W.H; Lawrence, C.J. [Ryerson Polytechnic Univ., Toronto, ON (Canada). Dept. of Mechanical and Industrial Engineering; Tarnawski, V.R. [Saint Mary' s Univ., Halifax, NS (Canada). Dept. of Engineering; Rosen, M.A. [University of Ontario Institute of Technology, Oshawa, ON (Canada). Faculty of Engineering and Applied Science

2006-07-01

A ground-coupled heat pump (GCHP) system for heating and cooling a residential house in Ontario was simulated. The system uses the surface ground as a thermal energy storage for storing thermal energy in the summer for later use in the winter. In the summer, the ground receives both solar energy and the heat rejected by the system during cooling operation. The relationship between a heat pump and the ground is a ground heat exchanger (GHE). This presentation described the vertical and horizontal configurations of the GHE, which are the 2 basic configurations. It also described the modelling and analysis of the GCHP system. The modelling involved both simplified and comprehensive models. The simplified models of heating and cooling loads of a building, a heat pump unit, and heat transfer at the ground heat exchanger provided a direct link to the comprehensive model of heat and moisture transfer in the ground, based on the finite element method. This combination of models provided an accurate and practical simulation tool for GCHP systems. The energy analysis was used to evaluate the performance of the system. The use of a horizontal ground heat exchanging pipe and the impact of heat deposition and extraction through it in the ground were also studied with reference to the length of pipe, depth of pipe and layout of the pipe loop. The objective of the analysis was to find ways to optimize the thermal performance of the system and environmental sustainability of the ground. 14 refs., 3 tabs., 5 figs.

Making the Paradigm Shift from Siloed Population Health Management to an Enterprise-Wide Approach.

Science.gov (United States)

Matthews, Marc R; Miller, Claudia; Stroebel, Robert J; Bunkers, Kari S

2017-08-01

Health systems across the United States have started their journeys toward population health management and the future of accountable care. Models of population health management include patient-centered medical homes and private sector accountable care organizations (ACOs). Other models include public sector efforts, such as Physician Group Practice Transition Demonstrations, Medicare Health Care Quality Demonstration Programs, Beacon Communities, Medicare Shared Savings Program, and Pioneer ACOs. As a result, health care organizations often have pockets of population health initiatives that lack an enterprise-wide strategy. The next steps are to build on these efforts, leverage the learnings from these experiences, and incorporate the initiatives into an overarching framework and a road map for the future. This paper describes the current challenge many organizations face to implement an enterprise solution, describes how to transition from existing siloed initiatives, and shares a case study of how Mayo Clinic launched its Mayo Model of Community Care.

Revisiting Gill's Circulation. Dynamic Response to Diabatic Heating of Different Horizontal Extents

Science.gov (United States)

Reboredo, B.; Bellon, G.

2017-12-01

The horizontal extent of diabatic heating associated with the MJO is thought to be crucial to its development, and the inability of GCMs to simulate the spatial, horizontal organization of clouds is considered a leading hypothesis to explain their limited capacity to simulate MJO events. This prevents the MJO large-circulation response from developing and feeding back on the development of clouds. We apply mid-tropospheric heating of different size in simple linear and non-linear models of the tropical atmosphere following Gill's seminal work on heat-induced tropical circulations. Results show that there is a scale for which the characteristic circulation {Γ c} for the vertical advection of moisture to produce the latent heat mean {Q} gives a rough estimate of the real world MJO scale. Overturning circulation flow rates above {Γ c} account for a circulation that transports more moisture than necessary to be maintained, and below {Γ c}, circulation would not transport enough moisture to maintain circulation. This dynamic scale might constrain the size of the spatially-organised convection necessary to the development of an MJO event. However, other effects are expected to modulate this scale, such as vertical advection of moisture anomalies, horizontal advection, evaporation, radiative heating, and sensible heat fluxes.

Ground Shock Effects from Accidental Explosions

Science.gov (United States)

1976-11-01

1,200 P0 A = V P cp 8 Horizontal Dh = Dv tannin " 1 (cp/U)] Vh = Vv tan [sin" 1 (cp/U)] \\ - \\ tanfainŕ (cp/U)] For tan sin (c /U...explosive are not included in the present analysis . This effect will limit the credibility of the direct- induced ground shock predictions, but if the... analysis . Dr. D. R. Richmond of Lovelace Foundation provided data on human shock tolerances. 26 REFERENCES 1. "Structures to Resist the Effects of

Tundra plant above-ground biomass and shrub dominance mapped across the North Slope of Alaska

Science.gov (United States)

Berner, Logan T.; Jantz, Patrick; Tape, Ken D.; Goetz, Scott J.

2018-03-01

Arctic tundra is becoming greener and shrubbier due to recent warming. This is impacting climate feedbacks and wildlife, yet the spatial distribution of plant biomass in tundra ecosystems is uncertain. In this study, we mapped plant and shrub above-ground biomass (AGB; kg m-2) and shrub dominance (%; shrub AGB/plant AGB) across the North Slope of Alaska by linking biomass harvests at 28 field sites with 30 m resolution Landsat satellite imagery. We first developed regression models (p plant AGB (r 2 = 0.79) and shrub AGB (r 2 = 0.82) based on the normalized difference vegetation index (NDVI) derived from imagery acquired by Landsat 5 and 7. We then predicted regional plant and shrub AGB by combining these regression models with a regional Landsat NDVI mosaic built from 1721 summer scenes acquired between 2007 and 2016. Our approach employed a Monte Carlo uncertainty analysis that propagated sampling and sensor calibration errors. We estimated that plant AGB averaged 0.74 (0.60, 0.88) kg m-2 (95% CI) and totaled 112 (91, 135) Tg across the region, with shrub AGB accounting for ~43% of regional plant AGB. The new maps capture landscape variation in plant AGB visible in high resolution satellite and aerial imagery, notably shrubby riparian corridors. Modeled shrub AGB was strongly correlated with field measurements of shrub canopy height at 25 sites (rs  = 0.88) and with a regional map of shrub cover (rs  = 0.76). Modeled plant AGB and shrub dominance were higher in shrub tundra than graminoid tundra and increased between areas with the coldest and warmest summer air temperatures, underscoring the fact that future warming has the potential to greatly increase plant AGB and shrub dominance in this region. These new biomass maps provide a unique source of ecological information for a region undergoing rapid environmental change.

Evaluation of Above Ground Biomass Estimation Accuracy for Alpine Meadow Based on MODIS Vegetation Indices

Directory of Open Access Journals (Sweden)

Meng Bao-Ping

2017-01-01

Full Text Available Animal husbandry is the main agricultural type over the Tibetan Plateau, above ground biomass (AGB is very important to monitor the productivity for administration of grassland resources and grazing balance. The MODIS vegetation indices have been successfully used in numerous studies on grassland AGB estimation in the Tibetan Plateau area. However, there are considerable differences of AGB estimation models both in the form of the models and the accuracy of estimation. In this study, field measurements of AGB data at Sangke Town, Gansu Province, China in four years (2013-2016 and MODIS indices (NDVI and EVI are combined to construct AGB estimation models of alpine meadow grassland. The field measured AGB are also used to evaluate feasibility of models developed for large scale in applying to small area. The results show that (1 the differences in biomass were relatively large among the 5 sample areas of alpine meadow grassland in the study area during 2013-2016, with the maximum and minimum biomass values of 3,963 kg DW/ha and 745.5 kg DW/ha, respectively, and mean value of 1,907.7 kg DW/ha; the mean of EVI value range (0.42-0.60 are slightly smaller than the NDVI’s (0.59-0.75; (2 the optimum estimation model of grassland AGB in the study area is the exponential model based on MODIS EVI, with root mean square error of 656.6 kg DW/ha and relative estimation errors (REE of 36.3%; (3 the estimation errors of grassland AGB models previously constructed at different spatial scales (the Tibetan Plateau, the Gannan Prefecture, and Xiahe County are higher than those directly constructed based on the small area of this study by 9.5%–31.7%, with the increase of the modeling study area scales, the REE increasing as well. This study presents an improved monitoring algorithm of alpine natural grassland AGB estimation and provides a clear direction for future improvement of the grassland AGB estimation and grassland productivity from remote sensing

Permafrost degradation and associated ground settlement estimation under 2 °C global warming

Science.gov (United States)

Guo, Donglin; Wang, Huijun

2017-10-01

Global warming of 2 °C above preindustrial levels has been considered to be the threshold that should not be exceeded by the global mean temperature to avoid dangerous interference with the climate system. However, this global mean target has different implications for different regions owing to the globally nonuniform climate change characteristics. Permafrost is sensitive to climate change; moreover, it is widely distributed in high-latitude and high-altitude regions where the greatest warming is predicted. Permafrost is expected to be severely affected by even the 2 °C global warming, which, in turn, affects other systems such as water resources, ecosystems, and infrastructures. Using air and soil temperature data from ten coupled model intercomparison project phase five models combined with observations of frozen ground, we investigated the permafrost thaw and associated ground settlement under 2 °C global warming. Results show that the climate models produced an ensemble mean permafrost area of 14.01 × 106 km2, which compares reasonably with the area of 13.89 × 106 km2 (north of 45°N) in the observations. The models predict that the soil temperature at 6 m depth will increase by 2.34-2.67 °C on area average relative to 1990-2000, and the increase intensifies with increasing latitude. The active layer thickness will also increase by 0.42-0.45 m, but dissimilar to soil temperature, the increase weakens with increasing latitude due to the distinctly cooler permafrost at higher latitudes. The permafrost extent will obviously retreat north and decrease by 24-26% and the ground settlement owing to permafrost thaw is estimated at 3.8-15 cm on area average. Possible uncertainties in this study may be mostly attributed to the less accurate ground ice content data and coarse horizontal resolution of the models.

Mechanical and mathematical models of multi-stage horizontal fracturing strings and their application

Directory of Open Access Journals (Sweden)

Zhanghua Lian

2015-03-01

Full Text Available Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs, but on the other hand makes the mechanical environment of fracturing strings more complicated at the same time. In view of this, based on the loading features of tubing strings during the multi-stage fracturing of a horizontal well, mechanical models were established for three working cases of multiple packer setting, open differential-pressure sliding sleeve, and open ball-injection sliding sleeve under a hold-down packer. Moreover, mathematical models were respectively built for the above three cases. According to the Lame formula and Von Mises stress calculation formula for the thick-walled cylinder in the theory of elastic mechanics, a mathematical model was also established to calculate the equivalent stress for tubing string safety evaluation when the fracturing string was under the combined action of inner pressure, external squeezing force and axial stress, and another mathematical model was built for the mechanical strength and safety evaluation of multi-stage fracturing strings. In addition, a practical software was developed for the mechanical safety evaluation of horizontal well multi-stage fracturing strings according to the mathematical model developed for the mechanical calculation of the multi-packer string in horizontal wells. The research results were applied and verified in a gas well of Tahe Oilfield in the Tarim Basin with excellent effects, providing a theoretical basis and a simple and reliable technical means for optimal design and safety evaluation of safe operational parameters of multi-stage fracturing strings in horizontal wells.

Analytical solution for vacuum preloading considering the nonlinear distribution of horizontal permeability within the smear zone.

Directory of Open Access Journals (Sweden)

Jie Peng

Full Text Available The vacuum preloading is an effective method which is widely used in ground treatment. In consolidation analysis, the soil around prefabricated vertical drain (PVD is traditionally divided into smear zone and undisturbed zone, both with constant permeability. In reality, the permeability of soil changes continuously within the smear zone. In this study, the horizontal permeability coefficient of soil within the smear zone is described by an exponential function of radial distance. A solution for vacuum preloading consolidation considers the nonlinear distribution of horizontal permeability within the smear zone is presented and compared with previous analytical results as well as a numerical solution, the results show that the presented solution correlates well with the numerical solution, and is more precise than previous analytical solution.

Comparison of Light Interception and Field Photosynthesis between Vertically and Horizontally Trained Watermelon [Citrullus lanatus (Thunb.) Matsum. et Nakai] Plants

International Nuclear Information System (INIS)

Watanabe, S.; Nakano, Y.; Okano, K.

2001-01-01

The light-interception characteristics and field photosynthetic rates of individual leaves were compared between vertically and horizontally trained watermelon plants to determine why the former produced smaller fruit than the latter. The planting density of the vertically trained plants was 3 times greater than that of the horizontally trained plants, because in the former the shoots were trained upward, whereas the latter were spread on the ground. Although the amount of solar radiation received by the upper leaves was similar in both plots, significantly less light was received by the middle and lower leaves of the vertically trained plants than by those of the horizontally trained ones. In the vertically trained plants, the photosynthetic rate was high at the upper leaves and decreased gradually with lower leaf positions. The photosynthetic rate in the horizontally trained plants was generally high, but the difference in the rate among leaves in different positions varied. We conclude that the main reason for the lighter fruits on the vertically trained watermelon plants is that the middle and lower leaves received less light because of shading compared with horizontally grown vines

Well completion report on installation of horizontal wells for in-situ remediation tests

International Nuclear Information System (INIS)

Kaback, D.S.; Looney, B.B.; Corey, J.C.; Wright, L.M.

1989-08-01

A project to drill and install two horizontal vapor extraction/air-injection wells at the Savannah River Site (SRS), Aiken, South Carolina, was performed in September and October of 1988. This study was performed to test the feasibility of horizontal drilling technologies in unconsolidated sediments and to evaluate the effectiveness of in-situ air stripping of volatile organics from the ground water and unsaturated soils. A tremendous amount of knowledge was obtained during the drilling and installation of the two test wells. Factors of importance to be considered during design of another horizontal well drilling program follow. (1) Trips in and out of the borehole should be minimized to maintain hole stability. No reaming to enlarge the hole should be attempted. (2) Drilling fluid performance should be maximized by utilizing a low solids, low weight, moderate viscosity, high lubricity fluid. Interruption of drilling fluid circulation should be minimized. (3) Well materials should possess adequate flexibility to negotiate the curve. A flexible guide should be attached to the front of the well screen to guide the screen downhole. (4) Sands containing a minor amount of clay are recommended for completion targets, as better drilling control in the laterals was obtained in these sections

Natural Convection Heat Transfer in Concentric Horizontal Annuli Containing a Saturated Porous Medi

Directory of Open Access Journals (Sweden)

Ahmed F. Alfahaid, R.Y. Sakr

2012-10-01

Full Text Available Natural convection in horizontal annular porous media has become a subject receiving increasing attention due to its practical importance in the problem of insulators, such as ducting system in high temperature gas-cooled reactors, heating systems, thermal energy storage systems, under ground cable systems, etc. This paper presents a numerical study for steady state thermal convection in a fully saturated porous media bounded by two horizontal concentric cylinders, the cylinders are impermeable to fluid motion and maintained at different, uniform temperatures.  The solution scheme is based on two-dimensional model, which is governed by Darcy-Oberbeck-Boussinesq equations. The finite element method using Galerkin technique is developed and employed to solve the present problem. A numerical simulation is carried out to examine the parametric effects of Rayleigh number and radius ratio on the role played by natural convection heat transfer in the porous annuli. The numerical results obtained from the present model were compared with the available published results and good agreement is observed. The average Nusselt number at the heating surface of the inner cylinder is correlated to Rayleigh number and radius ratio.Keywords: Natural convection, numerical investigation, saturated porous media, finite element method, concentric horizontal annuli.

Fundamental study on airborne electromagnetic survey using grounded source; Chihyo source gata kuchu denji tansa no kisoteki kenkyu. 2

Energy Technology Data Exchange (ETDEWEB)

Mogi, T; Fujimitsu, Y [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Tanaka, Y [Kyoto University, Kyoto (Japan). Faculty of Science; Jomori, N [Chiba Electronics Research Institute, Chiba (Japan); Morikawa, T [Dowa Engineering Co. Ltd., Okayama (Japan); Kusunoki, K [Central Research Institute of Electric Power Industry, Tokyo (Japan)

1997-05-27

With an objective to develop an airborne electromagnetic survey method for greater depths achievable of exploration, a discussion was given on an exploration method of a type in which a transmitting device is placed on the ground to receive signals in an atmosphere. A prototype exploration apparatus is mounted with a fluxgate magnetometer, an attitude meter, a GPS, and a battery. This exploration apparatus is suspended on a 30 meter long rope from a helicopter to perform the exploration. Two flight tests on this apparatus were carried out in the Unzen area, Nagasaki Prefecture and the Motomiya area, Wakayama Prefecture. The ground source was extended to a distance of 1.5 km, and a current of about 20 A was flown with a quiescent wave having four-second cycles. The helicopter flew nearly horizontally at a ground speed of about 50 km, a flight altitude of 450 m above sea level, and a terrain clearances of 100 to 400 m. The obtained data had variations in correspondence with changes in roll and pitch angles, whereas the variation of about 5000 nT was reduced to about 1000 nT as a result of correction. It was not possible, however, to correct completely the variation with short cycles, requiring further discussions on frequency characteristics of the magnetometer. 6 figs., 1 tab.

Theoretical study of evaporation heat transfer in horizontal microfin tubes: stratified flow model

Energy Technology Data Exchange (ETDEWEB)

Honda, H; Wang, Y S [Kyushu Univ., Inst. for Materials Chemistry and Engineering, Kasuga, Fukuoka (Japan)

2004-08-01

The stratified flow model of evaporation heat transfer in helically grooved, horizontal microfin tubes has been developed. The profile of stratified liquid was determined by a theoretical model previously developed for condensation in horizontal microfin tubes. For the region above the stratified liquid, the meniscus profile in the groove between adjacent fins was determined by a force balance between the gravity and surface tension forces. The thin film evaporation model was applied to predict heat transfer in the thin film region of the meniscus. Heat transfer through the stratified liquid was estimated by using an empirical correlation proposed by Mori et al. The theoretical predictions of the circumferential average heat transfer coefficient were compared with available experimental data for four tubes and three refrigerants. A good agreement was obtained for the region of Fr{sub 0}<2.5 as long as partial dry out of tube surface did not occur. (Author)

Early Site Permit Demonstration Program: Guidelines for determining design basis ground motions

International Nuclear Information System (INIS)

1993-01-01

This report develops and applies a methodology for estimating strong earthquake ground motion. The motivation was to develop a much needed tool for use in developing the seismic requirements for structural designs. An earthquake's ground motion is a function of the earthquake's magnitude, and the physical properties of the earth through which the seismic waves travel from the earthquake fault to the site of interest. The emphasis of this study is on ground motion estimation in Eastern North America (east of the Rocky Mountains), with particular emphasis on the Eastern United States and southeastern Canada. Eastern North America is a stable continental region, having sparse earthquake activity with rare occurrences of large earthquakes. While large earthquakes are of interest for assessing seismic hazard, little data exists from the region to empirically quantify their effects. The focus of the report is on the attributes of ground motion in Eastern North America that are of interest for the design of facilities such as nuclear power plants. This document, Volume II, contains Appendices 2, 3, 5, 6, and 7 covering the following topics: Eastern North American Empirical Ground Motion Data; Examination of Variance of Seismographic Network Data; Soil Amplification and Vertical-to-Horizontal Ratios from Analysis of Strong Motion Data From Active Tectonic Regions; Revision and Calibration of Ou and Herrmann Method; Generalized Ray Procedure for Modeling Ground Motion Attenuation; Crustal Models for Velocity Regionalization; Depth Distribution Models; Development of Generic Site Effects Model; Validation and Comparison of One-Dimensional Site Response Methodologies; Plots of Amplification Factors; Assessment of Coupling Between Vertical ampersand Horizontal Motions in Nonlinear Site Response Analysis; and Modeling of Dynamic Soil Properties

Horizontal Accelerator

Data.gov (United States)

Federal Laboratory Consortium — The Horizontal Accelerator (HA) Facility is a versatile research tool available for use on projects requiring simulation of the crash environment. The HA Facility is...

Pilot study risk assessment for selected problems at the Fernald Environmental Management Project (FEMP)

Energy Technology Data Exchange (ETDEWEB)

Hamilton, L.D.; Meinhold, A.F.; Baxter, S.L.; Holtzman, S.; Morris, S.C.; Pardi, R.; Rowe, M.D.; Sun, C. (Brookhaven National Lab., Upton, NY (United States)); Anspaugh, L.; Layton, D. (Lawrence Livermore National Lab., CA (United States))

1993-03-01

Two important environmental problems at the USDOE Fernald Environmental Management Project (FEMP) facility in Fernald, Ohio were studied in this human health risk assessment. The problems studied were radon emissions from the K-65 waste silos, and offsite contamination of ground water with uranium. Waste from the processing of pitchblende ore is stored in the K-65 silos at the FEMP. Radium-226 in the waste decays to radon gas which escapes to the outside atmosphere. The concern is for an increase in lung cancer risk for nearby residents associated with radon exposure. Monitoring data and a gaussian plume transport model were used to develop a source term and predict exposure and risk to fenceline residents, residents within 1 and 5 miles of the silos, and residents of Hamilton and Cincinnati, Ohio. Two release scenarios were studied: the routine release of radon from the silos and an accidental loss of one silo dome integrity. Exposure parameters and risk factors were described as distributions. Risks associated with natural background radon concentrations were also estimated.

Pilot study risk assessment for selected problems at the Fernald Environmental Management Project (FEMP)

International Nuclear Information System (INIS)

Hamilton, L.D.; Meinhold, A.F.; Baxter, S.L.; Holtzman, S.; Morris, S.C.; Pardi, R.; Rowe, M.D.; Sun, C.; Anspaugh, L.; Layton, D.

1993-03-01

Two important environmental problems at the USDOE Fernald Environmental Management Project (FEMP) facility in Fernald, Ohio were studied in this human health risk assessment. The problems studied were radon emissions from the K-65 waste silos, and offsite contamination of ground water with uranium. Waste from the processing of pitchblende ore is stored in the K-65 silos at the FEMP. Radium-226 in the waste decays to radon gas which escapes to the outside atmosphere. The concern is for an increase in lung cancer risk for nearby residents associated with radon exposure. Monitoring data and a gaussian plume transport model were used to develop a source term and predict exposure and risk to fenceline residents, residents within 1 and 5 miles of the silos, and residents of Hamilton and Cincinnati, Ohio. Two release scenarios were studied: the routine release of radon from the silos and an accidental loss of one silo dome integrity. Exposure parameters and risk factors were described as distributions. Risks associated with natural background radon concentrations were also estimated

Improving a maximum horizontal gradient algorithm to determine geological body boundaries and fault systems based on gravity data

Science.gov (United States)

Van Kha, Tran; Van Vuong, Hoang; Thanh, Do Duc; Hung, Duong Quoc; Anh, Le Duc

2018-05-01

The maximum horizontal gradient method was first proposed by Blakely and Simpson (1986) for determining the boundaries between geological bodies with different densities. The method involves the comparison of a center point with its eight nearest neighbors in four directions within each 3 × 3 calculation grid. The horizontal location and magnitude of the maximum values are found by interpolating a second-order polynomial through the trio of points provided that the magnitude of the middle point is greater than its two nearest neighbors in one direction. In theoretical models of multiple sources, however, the above condition does not allow the maximum horizontal locations to be fully located, and it could be difficult to correlate the edges of complicated sources. In this paper, the authors propose an additional condition to identify more maximum horizontal locations within the calculation grid. This additional condition will improve the method algorithm for interpreting the boundaries of magnetic and/or gravity sources. The improved algorithm was tested on gravity models and applied to gravity data for the Phu Khanh basin on the continental shelf of the East Vietnam Sea. The results show that the additional locations of the maximum horizontal gradient could be helpful for connecting the edges of complicated source bodies.

Topographic gradient based site characterization in India complemented by strong ground-motion spectral attributes

KAUST Repository

Nath, Sankar Kumar; Thingbaijam, Kiran Kumar; Adhikari, M. D.; Nayak, Avinash; Devaraj, N.; Ghosh, Soumalya K.; Mahajan, Arun K.

2013-01-01

We appraise topographic-gradient approach for site classification that employs correlations between 30. m column averaged shear-wave velocity and topographic gradients. Assessments based on site classifications reported from cities across India indicate that the approach is reasonably viable at regional level. Additionally, we experiment three techniques for site classification based on strong ground-motion recordings, namely Horizontal-to-Vertical Spectral Ratio (HVSR), Response Spectra Shape (RSS), and Horizontal-to-Vertical Response Spectral Ratio (HVRSR) at the strong motion stations located across the Himalayas and northeast India. Statistical tests on the results indicate that these three techniques broadly differentiate soil and rock sites while RSS and HVRSR yield better signatures. The results also support the implemented site classification in the light of strong ground-motion spectral attributes observed in different parts of the globe. © 2013 Elsevier Ltd.

Topographic gradient based site characterization in India complemented by strong ground-motion spectral attributes

KAUST Repository

Nath, Sankar Kumar

2013-12-01

We appraise topographic-gradient approach for site classification that employs correlations between 30. m column averaged shear-wave velocity and topographic gradients. Assessments based on site classifications reported from cities across India indicate that the approach is reasonably viable at regional level. Additionally, we experiment three techniques for site classification based on strong ground-motion recordings, namely Horizontal-to-Vertical Spectral Ratio (HVSR), Response Spectra Shape (RSS), and Horizontal-to-Vertical Response Spectral Ratio (HVRSR) at the strong motion stations located across the Himalayas and northeast India. Statistical tests on the results indicate that these three techniques broadly differentiate soil and rock sites while RSS and HVRSR yield better signatures. The results also support the implemented site classification in the light of strong ground-motion spectral attributes observed in different parts of the globe. © 2013 Elsevier Ltd.

Ultraviolet-B radiation and nitrogen affect nutrient concentrations and the amount of nutrients acquired by above-ground organs of maize.

Science.gov (United States)

Correia, Carlos M; Coutinho, João F; Bacelar, Eunice A; Gonçalves, Berta M; Björn, Lars Olof; Moutinho Pereira, José

2012-01-01

UV-B radiation effects on nutrient concentrations in above-ground organs of maize were investigated at silking and maturity at different levels of applied nitrogen under field conditions. The experiment simulated a 20% stratospheric ozone depletion over Portugal. At silking, UV-B increased N, K, Ca, and Zn concentrations, whereas at maturity Ca, Mg, Zn, and Cu increased and N, P and Mn decreased in some plant organs. Generally, at maturity, N, Ca, Cu, and Mn were lower, while P, K, and Zn concentrations in stems and nitrogen-use efficiency (NUE) were higher in N-starved plants. UV-B and N effects on shoot dry biomass were more pronounced than on nutrient concentrations. Nutrient uptake decreased under high UV-B and increased with increasing N application, mainly at maturity harvest. Significant interactions UV-B x N were observed for NUE and for concentration and mass of some elements. For instance, under enhanced UV-B, N, Cu, Zn, and Mn concentrations decreased in leaves, except on N-stressed plants, whereas they were less affected by N nutrition. In order to minimize nutritional, economical, and environmental negative consequences, fertiliser recommendations based on element concentration or yield goals may need to be adjusted.

Ultraviolet-B Radiation and Nitrogen Affect Nutrient Concentrations and the Amount of Nutrients Acquired by Above-Ground Organs of Maize

Directory of Open Access Journals (Sweden)

Carlos M. Correia

2012-01-01

Full Text Available UV-B radiation effects on nutrient concentrations in above-ground organs of maize were investigated at silking and maturity at different levels of applied nitrogen under field conditions. The experiment simulated a 20% stratospheric ozone depletion over Portugal. At silking, UV-B increased N, K, Ca, and Zn concentrations, whereas at maturity Ca, Mg, Zn, and Cu increased and N, P and Mn decreased in some plant organs. Generally, at maturity, N, Ca, Cu, and Mn were lower, while P, K, and Zn concentrations in stems and nitrogen-use efficiency (NUE were higher in N-starved plants. UV-B and N effects on shoot dry biomass were more pronounced than on nutrient concentrations. Nutrient uptake decreased under high UV-B and increased with increasing N application, mainly at maturity harvest. Significant interactions UV-B x N were observed for NUE and for concentration and mass of some elements. For instance, under enhanced UV-B, N, Cu, Zn, and Mn concentrations decreased in leaves, except on N-stressed plants, whereas they were less affected by N nutrition. In order to minimize nutritional, economical, and environmental negative consequences, fertiliser recommendations based on element concentration or yield goals may need to be adjusted.

Effect of high-extraction coal mining on surface and ground waters

International Nuclear Information System (INIS)

Kendorski, F.S.

1993-01-01

Since first quantified around 1979, much new data have become available. In examining the sources of data and the methods and intents of the researchers of over 65 case histories, it became apparent that the strata behaviors were being confused with overlapping vertical extents reported for the fractured zones and aquiclude zones depending on whether the researcher was interested in water intrusion into the mine or in water loss from surface or ground waters. These more recent data, and critical examination of existing data, have led to the realization that the former Aquiclude Zone defined for its ability to prevent or minimize the intrusion of ground or surface waters into mines has another important character in increasing storage of surface and shallow ground waters in response to mining with no permanent loss of waters. This zone is here named the Dilated Zone. Surface and ground waters can drain into this zone, but seldom into the mine, and can eventually be recovered through closing of dilations by mine subsidence progression away from the area, or filling of the additional void space created, or both. A revised model has been developed which accommodates the available data, by modifying the zones as follows: collapse and disaggregation extending 6 to 10 times the mined thickness above the panel; continuous fracturing extending approximately 24 times the mined thickness above the panel, allowing temporary drainage of intersected surface and ground waters; development of a zone of dilated, increased storativity, and leaky strata with little enhanced vertical permeability from 24 to 60 times the mined thickness above the panel above the continuous fracturing zone, and below the constrained or surface effects zones; maintenance of a constrained but leaky zone above the dilated zone and below the surface effects zone; and limited surface fracturing in areas of extension extending up to 50 ft or so beneath the ground surface. 119 ref., 5 figs., 2 tabs

Horizontal drilling under Lake Erie

Energy Technology Data Exchange (ETDEWEB)

Meller, R.

2001-07-01

Drilling oil wells under Lake Erie calls for horizontal drilling wells to be drilled from shore out into the pay-zone under the lake. The nature and characteristics of horizontal wells as compared to vertical wells are explored. Considerations that have to be taken into account in drilling horizontal wells are explained (the degree of curvature, drilling fluid quality, geosteering in the pay-zone, steering instrumentation, measurements while drilling (MWD), logging while drilling (LWD)). The concept and reasons for extended reach wells are outlined, along with characteristic features of multilateral wells.

Alterations to the orientation of the ground reaction force vector affect sprint acceleration performance in team sports athletes.

Science.gov (United States)

Bezodis, Neil E; North, Jamie S; Razavet, Jane L

2017-09-01

A more horizontally oriented ground reaction force vector is related to higher levels of sprint acceleration performance across a range of athletes. However, the effects of acute experimental alterations to the force vector orientation within athletes are unknown. Fifteen male team sports athletes completed maximal effort 10-m accelerations in three conditions following different verbal instructions intended to manipulate the force vector orientation. Ground reaction forces (GRFs) were collected from the step nearest 5-m and stance leg kinematics at touchdown were also analysed to understand specific kinematic features of touchdown technique which may influence the consequent force vector orientation. Magnitude-based inferences were used to compare findings between conditions. There was a likely more horizontally oriented ground reaction force vector and a likely lower peak vertical force in the control condition compared with the experimental conditions. 10-m sprint time was very likely quickest in the control condition which confirmed the importance of force vector orientation for acceleration performance on a within-athlete basis. The stance leg kinematics revealed that a more horizontally oriented force vector during stance was preceded at touchdown by a likely more dorsiflexed ankle, a likely more flexed knee, and a possibly or likely greater hip extension velocity.

Uprooting force balance for pioneer woody plants: A quantification of the relative contribution of above- and below-ground plant architecture to uprooting susceptibility

Science.gov (United States)

Bywater-Reyes, S.; Wilcox, A. C.; Lightbody, A.; Skorko, K.; Stella, J. C.

2012-12-01

Cottonwood (Populus), willow (Salix), and tamarisk (Tamarix) populate riparian areas in many dryland regions, and their recruitment depends heavily on hydrogeomorphic conditions. The survival of pioneer woody seedlings depends in part on the establishment of root systems capable of anchoring plants in subsequent floods, and this root system development in turn influences the cohesion that plants provide to bars. The factors influencing the anchoring ability and resistance to scour of woody seedlings include plant frontal area and flexibility, root structure, and water table elevation. This study aims to quantify the factors comprising the force balance to uproot woody seedlings and saplings in two field sites characterized by different hydrologic conditions. The Bill Williams River (AZ) is an impounded river with elevated water table elevations produced by dam-released base flows. The Bitterroot River (MT) is an unimpounded river with a snowmelt hydrograph and seasonal fluctuations in river and water table elevation. We simulate uprooting from flooding events by saturating substrates and applying force near the base of the plant in a lateral, downstream direction until uprooting occurs, for a range of plant sizes but with a focus on small (plants, with cottonwood and tamarisk seedlings showing greater variability than willow. In contrast, root length and stem diameter are only weakly correlated with pull-out force. By combining pull test results with measurements of geomorphic and groundwater conditions, this study provides insights into the relative contribution of a plant's above-ground and below-ground architecture to uprooting potential and into the feedbacks between vegetation and morphodynamics on river bars.

Penetrating particles in horizontal air showers

International Nuclear Information System (INIS)

Wohlenberg, J.; Boehm, E.

1975-01-01

Particle density and arrival time of muons has been measured in Horizontal Air Showers. 5,600 showers have been recorded in 7,800 hours. Using stringent selection criteria 155 showers have been found horizontal (zenith angle larger 70 0 ) in the size range 4.1 > lg N > 5.5. The muons observed in these showers can be explained by purely electromagnetic origin of horizontal showers. (orig.) [de

Site Specific Ground Response Analysis for Quantifying Site Amplification at A Regolith Site

Directory of Open Access Journals (Sweden)

Bambang Setiawan

2017-08-01

Full Text Available DOI: 10.17014/ijog.4.3.159-167A numerical model has demonstrated that it can simulate reasonably well earthquake motions at the ground level during a seismic event. The most widely used model is an equivalent linear approach. The equivalent linear model was used to compute the free-field response of Adelaide regolith during the 1997 Burra earthquake. The aim of this study is to quantify the amplification at the investigated site. The model computed the ground response of horizontally layered soil deposits subjected to transient and vertically propagating shear waves through a one-dimensional-soil column. Each soil layer was assumed to be homogeneous, visco-elastic, and infinite in the horizontal extent. The results of this study were compared to other studies and forward computation of the geotechnical dynamic parameters of the investigated site. The amplification triggered by the 1997 Burra seismic event was deduced. This study reveals the amplification factor up to 3.6 at the studied site.

Federated Ground Station Network Model and Interface Specification

Science.gov (United States)

2014-12-01

of-sight of a small portion of the ground at any moment due to the geometry of a satellite in LEO above a planet of Earth’s size. The portion of the...Subnetwork 3 started out as a lone network in which there was a single CA and a number of ground stations. Then Subnetwork 3 joined with SA 1 and its

Horizontal violence in Nursing

Directory of Open Access Journals (Sweden)

Tsimoulaki Evangelia

2017-01-01

Full Text Available One’s effort to clarify the definition of horizontal labour violence is of great importance, due to the variety of definitions that are mentioned in the worldwide scientific literature. Furthermore, the reference of multiple forms of such violence herein the nurse professional group is challenging, as well. Another fact of great importance is that, any form of professional violence (horizontal violence, horizontal mobbing in the work place environment can be possibly escalated and include even physical abuse (Bullying, besides the psychological and emotional impact for the victim. The definitions of Horizontal violence, Mobbing and Bullying, include a repeated negative behaviour emanating from at least one “predator” towards at least one “victim”, with work status differences and the existence or lack of physical abuse (Bullying. Horizontal violence is a hostile, aggressive and harmful behaviour which is either overt or concealed and is pointed from an individual to another individual of the same working rank and causes intense emotional pain at the victim. The manifestations vary from humiliating tasks assignment or the victim’s efforts undermining to clearly aggressive behaviors (criticism, intimidation, sarcasm etc.. The reason behind this phenomenon is multifactorial extended not only towards the working environment but also to the personal characteristics of the “predator” as well as the possible “victim”. The researchers emphasize the high incidence of the phenomenon, as well as the cost that is induced by the violent behaviors to both the health professionals and the hospital. Finally, they point out the paradox of the presence of violence inside a system that is designed to promote health.

Horizontal steam generator thermal-hydraulics

Energy Technology Data Exchange (ETDEWEB)

Ubra, O. [SKODA Praha Company, Prague (Czechoslovakia); Doubek, M. [Czech Technical Univ., Prague (Czechoslovakia)

1995-09-01

Horizontal steam generators are typical components of nuclear power plants with pressure water reactor type VVER. Thermal-hydraulic behavior of horizontal steam generators is very different from the vertical U-tube steam generator, which has been extensively studied for several years. To contribute to the understanding of the horizontal steam generator thermal-hydraulics a computer program for 3-D steady state analysis of the PGV-1000 steam generator has been developed. By means of this computer program, a detailed thermal-hydraulic and thermodynamic study of the horizontal steam generator PGV-1000 has been carried out and a set of important steam generator characteristics has been obtained. The 3-D distribution of the void fraction and 3-D level profile as functions of load and secondary side pressure have been investigated and secondary side volumes and masses as functions of load and pressure have been evaluated. Some of the interesting results of calculations are presented in the paper.

Study of the Local Horizon. (Spanish Title: Estudio del Horizonte Local.) Estudo do Horizonte Local

Science.gov (United States)

Ros, Rosa M.

2009-12-01

The study of the horizon is fundamental to easy the first observations of the students at any education center. A simple model, to be developed in each center, allows to easy the study and comprehension of the rudiments of astronomy. The constructed model is presented in turn as a simple equatorial clock, other models (horizontal and vertical) may be constructed starting from it. El estudio del horizonte es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido se presenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (horizontal y vertical). O estudo do horizonte é fundamental para facilitar as primeiras observações dos alunos num centro educativo. Um modelo simples, que deve ser feito para cada centro, permite facilitar o estudo e a compreensão dos primeiros rudimentos astronômicos. O modelo construído apresenta-se, por sua vez, como um modelo simples de relógio equatorial e a partir dele pode-se construir outros modelos (horizontal e vertical)

An alternative approach for estimating above ground biomass using Resourcesat-2 satellite data and artificial neural network in Bundelkhand region of India.

Science.gov (United States)

Deb, Dibyendu; Singh, J P; Deb, Shovik; Datta, Debajit; Ghosh, Arunava; Chaurasia, R S

2017-10-20

Determination of above ground biomass (AGB) of any forest is a longstanding scientific endeavor, which helps to estimate net primary productivity, carbon stock and other biophysical parameters of that forest. With advancement of geospatial technology in last few decades, AGB estimation now can be done using space-borne and airborne remotely sensed data. It is a well-established, time saving and cost effective technique with high precision and is frequently applied by the scientific community. It involves development of allometric equations based on correlations of ground-based forest biomass measurements with vegetation indices derived from remotely sensed data. However, selection of the best-fit and explanatory models of biomass estimation often becomes a difficult proposition with respect to the image data resolution (spatial and spectral) as well as the sensor platform position in space. Using Resourcesat-2 satellite data and Normalized Difference Vegetation Index (NDVI), this pilot scale study compared traditional linear and nonlinear models with an artificial intelligence-based non-parametric technique, i.e. artificial neural network (ANN) for formulation of the best-fit model to determine AGB of forest of the Bundelkhand region of India. The results confirmed the superiority of ANN over other models in terms of several statistical significance and reliability assessment measures. Accordingly, this study proposed the use of ANN instead of traditional models for determination of AGB and other bio-physical parameters of any dry deciduous forest of tropical sub-humid or semi-arid area. In addition, large numbers of sampling sites with different quadrant sizes for trees, shrubs, and herbs as well as application of LiDAR data as predictor variable were recommended for very high precision modelling in ANN for a large scale study.

Satellite-to-ground radiowave propagation

CERN Document Server

Allnutt, JE

2011-01-01

This book is a follow up to the award winning first edition and is written as a comprehensive guide for those who need to obtain a working knowledge of radiowave propagation on satellite-to-ground links at frequencies above 1 GHz, and as a reference book for experts in the field.

Macroscopic quantum coherence in a magnetic nanoparticle above the surface of a superconductor

Science.gov (United States)

Chudnovsky; Friedman

2000-12-11

We study macroscopic quantum tunneling of the magnetic moment in a single-domain particle placed above the surface of a superconductor. Such a setup allows one to manipulate the height of the energy barrier, preserving the degeneracy of the ground state. The tunneling amplitude and the effect of the dissipation in the superconductor are computed.

Macroscopic Quantum Coherence in a Magnetic Nanoparticle Above the Surface of a Superconductor

Energy Technology Data Exchange (ETDEWEB)

Chudnovsky, Eugene M.; Friedman, Jonathan R.

2000-12-11

We study macroscopic quantum tunneling of the magnetic moment in a single-domain particle placed above the surface of a superconductor. Such a setup allows one to manipulate the height of the energy barrier, preserving the degeneracy of the ground state. The tunneling amplitude and the effect of the dissipation in the superconductor are computed.

Macroscopic Quantum Coherence in a Magnetic Nanoparticle Above the Surface of a Superconductor

International Nuclear Information System (INIS)

Chudnovsky, Eugene M.; Friedman, Jonathan R.

2000-01-01

We study macroscopic quantum tunneling of the magnetic moment in a single-domain particle placed above the surface of a superconductor. Such a setup allows one to manipulate the height of the energy barrier, preserving the degeneracy of the ground state. The tunneling amplitude and the effect of the dissipation in the superconductor are computed

Nature of short-period microtremors on the cliff-like ground. part 6; Gakechi kinbo no tanshuki bido. 6

Energy Technology Data Exchange (ETDEWEB)

Maiguma, T; Kimura, Y [Waseda University, Tokyo (Japan). School of Science and Engineering; Yasui, [Toda Corp., Tokyo, (Japan)

1997-10-22

Short-period microtremors were observed on the cliff-like ground to discuss vibration characteristics of the ground. It is known that damage of an earthquake becomes especially serious in the vicinity of the cliff-like ground with steep slopes. The present investigation has performed observations on short-period microtremors in two cliff-like grounds, one with a height of about 17 m and an inclination angle of about 55 degrees, and another with a height of 11 m and an inclination angle of about 60 degrees. The areas of the investigation are the Musashino tableland of the Pleistocene era covered by the Kanto loam bed, and the Oritate area (a farm land) with the cliff-like ground which has been formed as a result of erosion of a river terrace consisted of a gravel bed. The observation was carried out with nine moving coil type vibration converters having a natural period of one second installed for horizontal movements and seven converters installed for vertical movements. The result of the investigation revealed that, at the Musashino tableland, no noticeable influence of the cliff-like ground was recognized in the short-period microtremors; at the Oritate area, the spectra of the horizontal movements vary largely with vibrating directions; and the cliff effect can be seen in microtremors with frequencies from 5 Hz to 9 Hz. 5 refs., 9 figs.

Physical model of the dispersion of a radioactive contaminant in the atmosphere above a heat island

International Nuclear Information System (INIS)

Toly, J.A.; Tenchine, D.

1984-01-01

The project deals with the impact of surface heating in urban areas on the dispersion of contaminants in the atmosphere. - The atmospheric boundary layer is simulated in a water flume. Ground heating is applied locally reproducing the heat flux of an urban region. Fission products for which internal heat source is neglected are simulated by horizontal plumes at pHs different from the original pH of the flume. - The main results of the study concern: the characterization of the internal boundary layer downstream of the leading edge of the heated ground; the comparison of the concentration distributions of pollutants with and without surface heating. - A transposition of the results, expressed in terms of global parameters, enables information on the heat island effect due to urban regions on the dispersion of contaminants in the atmosphere to be obtained

Geology and ground water in the Platte-Republican Rivers watershed and the Little Blue River basin above Angus, Nebraska, with a section on chemical quality of the ground water

Science.gov (United States)

Johnson, C.R.; Brennan, Robert

1960-01-01

This report describes an area of about 7,300 square miles in south-central Nebraska. Approximately one-fourth of the area, largely at its east end, consists of an undissected southeastward-sloping upland plain and is almost wholly irrigable; the remainder is in various stages of dissection and only parts of it are suitable for irrigation. Although some of the deeper lying bedrock formations are potential sources of water supply, they are not likely to be tapped in the near future because abundant supplies are available at shallower depth from semiconsolidated and unconsolidated deposits. The Ogallala formation of Tertiary (Pliocene) age consists of gravel, sand, silt, and volcanic ash, some layers of which are partly cemented. It was deposited by eastward-flowing streams, which formed a constructional plain above a surface into which the streams had previously eroded broad valleys. In turn, valleys were cut into the surface of the Ogallala before the overlying deposits of gravel, sand, silt, and clay of Quaternary (Pleistocene) age were laid down, also forming a constructional plain. During Recent time, streams have dissected the older deposits and have deposited thin alluvium in their valleys; also, several parts of the area have become mantled by wind-deposited sand. Because during Tertiary and Quaternary time the area repeatedly was the site of deposition and erosion, the thickness of all the stratigraphic units differs markedly from place to place. In general, however, the Ogallala formation thins eastward and in the central and eastern parts of the area is overlain by the eastward-thickening deposits of Pleistocene age. The maximum thickness of the Ogallala formation is about 500 feet, and the maximum thickness of the Pleistocene deposits is a little more than 300 feet. Each thins to a featheredge and is completely absent in parts of the area. The water-bearing part of the combined Tertiary and Pleistocene deposits is considered to be a single zone of

Ground based measurements of SO2 and NO2 emissions from the oil refinery 'la Teja' in Montevideo city

International Nuclear Information System (INIS)

Frins, Erna; Casaballe, Nicolas; Osorio, Matias; Arismendi, Federico; Ibrahim, Ossama; Wagner, Thomas; Platt, Ulrich

2011-01-01

We present preliminary results of ground based measurements of SO 2 and NO 2 emissions from 'La Teja' oil refinery located in the northern part of Montevideo Bay. Our study is part of a long term effort to localize and monitor relevant emission sources in the city area of Montevideo. These measurements were performed with a Miniature Multi AXis Differential Optical Absorption Spectrometry (MiniMAX-DOAS) instrument, which is basically a temperature controlled medium-resolution spectrometer (∼ 0.5 nm) equipped with a small telescope and a stepper motor allowing automatic scans in one dimension. We present a discussion about the evolution and transformation of both above species in the atmosphere. Our observation site was approximately 1.9 km away from the oil refinery and we were able to perform vertical and horizontal scans of the plume emitted (during our measurements) almost horizontally from its stacks. The maximum value of the SO 2 slant column density (SCD) was found to be ∼ 4x10 17 molec cm -2 directly over the oil refinery, decreasing as the plume disperses. In contrast, the NO 2 SCD peaks at ∼ 1x10 16 molec cm -2 directly over the source and increases continuously as the plume disperses. The SO 2 flux measured immediately downwind of the refinery was found to be about 1200 kg h -1 (±40% uncertainty).

Modelling of Edge Insulation Depending on Boundary Conditions for the Ground Level

Science.gov (United States)

Stolarska, Agata; Strzałkowski, Jarosław

2017-10-01

The article presents results of CFD software aided simulations of a thermal bridge, existing at the wall-slab on ground connection. Calculations were made for different variants of the edge insulation location. Schemes without any edge insulation, with some vertical insulation, horizontal, diagonal, and diagonal combined with insulation used as formwork under the slab on ground were analysed. Each variant was differentiated with boundary conditions for the ground. Vertical borders of the model in the ground, as well as the lower border were described in the first solution as adiabatic, while in the second case, a variable temperature value, depending on the ground depth, was set. For comparison, additional calculations were conducted for non-stationary conditions, in which the initial temperature of the ground was set to the average annual temperature of air. The calculations were based on the location of Szczecin, for which the outside air temperature was set to -16.0°C. Results obtained from the simulation were then used to determine the thermal bridge parameters, in particular, thermal coupling coefficient and linear thermal transmittance. The effect of the set of boundary conditions is clearly seen. In general, for all the five variants, lower values of heat fluxes and linear thermal transmittances were obtained, when variable temperature in the ground was assumed. From the point of view of energy balance, it is more favourable to use the values of ψg obtained when the ground temperature is taken into account. The data breakdown shows that application of the actual temperature distribution in the ground to a model has a strong effect on distribution of the 0.0°C isotherm. The adiabatic model indicates that the ground under the slab freezes, while the model, which takes into account the temperature of the ground, shows that the ground under the floor has positive temperatures and the 0.0°C isotherm reaches only the edge of the outer wall. Moreover, the

The Development of an UAV Borne Direct Georeferenced Photogrammetric Platform for Ground Control Point Free Applications

Directory of Open Access Journals (Sweden)

Chien-Hsun Chu

2012-07-01

Full Text Available To facilitate applications such as environment detection or disaster monitoring, the development of rapid low cost systems for collecting near real time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. In this study, a fixed-wing Unmanned Aerial Vehicle (UAV-based spatial information acquisition platform that can operate in Ground Control Point (GCP free environments is developed and evaluated. The proposed UAV based photogrammetric platform has a Direct Georeferencing (DG module that includes a low cost Micro Electro Mechanical Systems (MEMS Inertial Navigation System (INS/ Global Positioning System (GPS integrated system. The DG module is able to provide GPS single frequency carrier phase measurements for differential processing to obtain sufficient positioning accuracy. All necessary calibration procedures are implemented. Ultimately, a flight test is performed to verify the positioning accuracy in DG mode without using GCPs. The preliminary results of positioning accuracy in DG mode illustrate that horizontal positioning accuracies in the x and y axes are around 5 m at 300 m flight height above the ground. The positioning accuracy of the z axis is below 10 m. Therefore, the proposed platform is relatively safe and inexpensive for collecting critical spatial information for urgent response such as disaster relief and assessment applications where GCPs are not available.

Feasibility of oil recovery by chemical flooding through horizontal wells

Energy Technology Data Exchange (ETDEWEB)

El-Abbas, A.M.; El-Sallaly, M. E.; Sayyouh, M. H.; El-Batanony, M. H.; Darwich, T. M.; Desouky, S. M. [Cairo Univ (Egypt)

1998-12-31

Crude oil production in the Gulf of Suez by polymer, surfactant, and surfactant/polymer flooding from a horizontal well in a scaled five-spot sandpacked model was studied. The suitability of the enhanced oil recovery predictive models, developed by the U.S. Department of Energy, was investigated for their ability to predict the experimental data and to assess the feasibility of oil recovery by chemical flooding. Good agreement was found between the predicted and experimental values. Experimental results showed that oil recovery was significantly affected by the physical properties of the crude oil and chemical solutions; that oil recovery was higher for a polymer flooding than for a surfactant flooding operation; and that oil recovery was improved by increasing the perforated length ratio up to a value of 0.81. A tendency for oil recovery to decrease was observed when the horizontal well was positioned below or above the central axis path of the formation at the advanced injection stages; and oil recovery by surfactant or polymer flooding was significantly affected by the onset timing of the surfactant or polymer slug injection. The oil-water bank stability in surfactant and polymer flooding processes was found to be dependent on slug size and slug injection time. 23 refs., 1 tab., 17 figs.

Representation of bidirectional ground motions for design spectra in building codes

Science.gov (United States)

Stewart, Jonathan P.; Abrahamson, Norman A.; Atkinson, Gail M.; Beker, Jack W.; Boore, David M.; Bozorgnia, Yousef; Campbell, Kenneth W.; Comartin, Craig D.; Idriss, I.M.; Lew, Marshall; Mehrain, Michael; Moehle, Jack P.; Naeim, Farzad; Sabol, Thomas A.

2011-01-01

The 2009 NEHRP Provisions modified the definition of horizontal ground motion from the geometric mean of spectral accelerations for two components to the peak response of a single lumped mass oscillator regardless of direction. These maximum-direction (MD) ground motions operate under the assumption that the dynamic properties of the structure (e.g., stiffness, strength) are identical in all directions. This assumption may be true for some in-plan symmetric structures, however, the response of most structures is dominated by modes of vibration along specific axes (e.g., longitudinal and transverse axes in a building), and often the dynamic properties (especially stiffness) along those axes are distinct. In order to achieve structural designs consistent with the collapse risk level given in the NEHRP documents, we argue that design spectra should be compatible with expected levels of ground motion along those principal response axes. The use of MD ground motions effectively assumes that the azimuth of maximum ground motion coincides with the directions of principal structural response. Because this is unlikely, design ground motions have lower probability of occurrence than intended, with significant societal costs. We recommend adjustments to make design ground motions compatible with target risk levels.

Structure and distribution of glandular and non-glandular trichomes on above-ground organs in Inula helenium L. (Asteraceae

Directory of Open Access Journals (Sweden)

Aneta Sulborska

2014-01-01

Full Text Available Micromorphology and distribution of glandular and non-glandular trichomes on the above-ground organs of Inula helenium L. were investigated using light and scanning electron microscopy (SEM. Two types of biseriate glandular trichomes, i.e. sessile and stalk hairs, and non-glandular trichomes were recorded. Sessile glandular trichomes were found on all examined I. helenium organs (with their highest density on the abaxial surface of leaves and disk florets, and on stems, whereas stalk glandular trichomes were found on leaves and stems. Sessile trichomes were characterised by a slightly lower height (58–103 μm and width (32–35 μm than the stalk trichomes (62–111 μm x 31–36 μm. Glandular hairs were composed of 5–7 (sessile trichomes or 6–9 (stalk trichomes cell tiers. Apical trichome cell tiers exhibited features of secretory cells. Secretion was accumulated in subcuticular space, which expanded and ruptured at the top, and released its content. Histochemical assays showed the presence of lipids and polyphenols, whereas no starch was detected. Non-glandular trichomes were seen on involucral bracts, leaves and stems (more frequently on involucral bracts. Their structure comprised 2–9 cells; basal cells (1–6 were smaller and linearly arranged, while apical cells had a prozenchymatous shape. The apical cell was the longest and sharply pointed. Applied histochemical tests revealed orange-red (presence of lipids and brow colour (presence of polyphenols in the apical cells of the trichomes. This may suggest that beside their protective role, the trichomes may participate in secretion of secondary metabolites.

UV hazard on Italian Apennines under different shading and ground cover conditions during peak tourist seasons of the year.

Science.gov (United States)

Grifoni, Daniele; Carreras, Giulia; Sabatini, Francesco; Zipoli, Gaetano

2006-12-01

In solar UV irradiance monitoring and forecasting services UV information is generally expressed in terms of its effect on erythema and referred to horizontal surface. In this work we define the UV radiative regime, in terms of biologically effective UV irradiance (UVBE) for skin and eye, under full sun and shaded conditions, over a mountainous tourist area of central Italy by means of two all-day measurements (summer and early spring) with different ground albedo (grass and snow cover respectively). UV irradiance was monitored on tilted surfaces (the most frequent for people standing and walking). Results show the significant contribution of ground albedo and sun position in determining the incident UVBE irradiance. On early spring days the UVBE irradiance measured on horizontal surface was much lower than on tilted ones; the opposite condition was observed in summer. The highest UVBE irradiance values, in particular conditions of sun elevation and ground cover, were reached in periods different from the summer both in full sun and shaded condition.

Cooperation of Horizontal Ground Heat Exchanger with the Ventilation Unit During Summer - Case Study

Science.gov (United States)

Romańska-Zapała, Anna; Furtak, Marcin; Dechnik, Mirosław

2017-10-01

Renewable energy sources are used in the modern energy-efficient buildings to improve their energy balance. One of them is used in the mechanical ventilation system ground air heat exchanger (earth-air heat exchanger - EAHX). This solution, right after heat recovery from exhaust air (recuperation), allows the reduction in the energy needed to obtain the desired temperature of supply air. The article presents the results of "in situ" measurements of pipe ground air heat exchanger cooperating with the air handling unit, supporting cooling the building in the summer season, in Polish climatic conditions. The laboratory consists of a ventilation unit intake - exhaust with rotor for which the source of fresh air is the air intake wall and two air intakes field cooperating with the tube with ground air heat exchangers. Selection of the source of fresh air is performed using sprocket with actuators. This system is part of the ventilation system of the Malopolska Laboratory of Energy-Efficient Building (MLBE) building of Cracow University of Technology. The measuring system are, among others, the sensors of parameters of air inlets and outlets of the heat exchanger channels EAHX and weather station that senses the local weather conditions. The measurement data are recorded and archived by the integrated process control system in the building of MLBE. During the study measurements of operating parameters of the ventilation unit cooperating with the selected source of fresh air were performed. Two cases of operation of the system: using EAHX heat exchanger and without it, were analyzed. Potentially the use of ground air heat exchanger in the mechanical ventilation system can reduce the energy demand for heating or cooling rooms by the pre-adjustment of the supply air temperature. Considering the results can be concluded that the continuous use of these exchangers is not optimal. This relationship is appropriate not only on an annual basis for the transitional periods (spring

HORIZONTAL WELL DRILL-IN FLUIDS

Directory of Open Access Journals (Sweden)

Nediljka Gaurina-Međimurec

1998-12-01

Full Text Available Main objective of horizontal driling is to place a drain-hole for a long distance within the pay zone to enhance productivity or injectivity. In drilling horizontal wells, more serious problems appear than in drilling vertical wells. These problems are: poor hole cleaning, excessive torque and drag, hole filling, pipe stucking, wellbore instability, loss of circulation, formation damage, poor cement job, and difficulties at logging jobs. From that reason, successful drilling and production of horizontal well depends largely on the fluid used during drilling and completion phases. Several new fluids, that fulfill some or all of required properties (hole cleaning, cutting suspension, good lubrication, and relative low formation damage, are presented in this paper.

Output characteristics of torsion arc blade type horizontal axis windmill; Nejire enko yokugata suiheijiku fusha no shutsuryoku tokusei

Energy Technology Data Exchange (ETDEWEB)

Kojima, N; Kishimura, K [Meiji University, Tokyo (Japan)

1997-11-25

The previous paper theoretically analyzes characteristics of a torsion arc blade type (TABT) horizontal axis windmill to derive the theoretical equations, which give the results in good agreement with the observed ones, when multiplied by a blade shape factor. This paper discusses that the theoretical and observed results are in good agreement with each other by taking into consideration shape-related solidity and number of blades. The following findings are obtained, when parameters related to a 6-blade TABT horizontal axis wind mill are introduced and hysteresis brake is used as the load resistance for torque measurement. Shape factor can be represented by two factors of blade number and solidity. The same equation for shape factor is applicable to both elliptical and rectangular blades. These blades need different theoretical equations to give the results in agreement with the observed ones, when operated at a tip speed ratio (TSR) of 1.77 and 1.58, respectively. Rotational force is affected by the rear blade shape when they are operated at a respective TSR below the above level, but unaffected at beyond the above level. 5 refs., 9 figs., 1 tab.

Productivity and injectivity of horizontal wells

Energy Technology Data Exchange (ETDEWEB)

Aziz, Khalid

2000-03-06

One of the key issues addressed was pressure drop in long horizontal wells and its influence on well performance. Very little information is available in the literature on flow in pipes with influx through pipe walls. Virtually all of this work has been in small diameter pipes and with single-phase flow. In order to address this problem new experimental data on flow in horizontal and near horizontal wells have been obtained. Experiments were conducted at an industrial facility on typical 6 1/8 ID, 100 feet long horizontal well model. The new data along with available information in the literature have been used to develop new correlations and mechanistic models. Thus it is now possible to predict, within reasonable accuracy, the effect of influx through the well on pressure drop in the well.

Incremental Dynamic Analysis of Koyna Dam under Repeated Ground Motions

Science.gov (United States)

Zainab Nik Azizan, Nik; Majid, Taksiah A.; Nazri, Fadzli Mohamed; Maity, Damodar; Abdullah, Junaidah

2018-03-01

This paper discovers the incremental dynamic analysis (IDA) of concrete gravity dam under single and repeated earthquake loadings to identify the limit state of the dam. Seven ground motions with horizontal and vertical direction as seismic input considered in the nonlinear dynamic analysis based on the real repeated earthquake in the worldwide. All the ground motions convert to respond spectrum and scaled according to the developed elastic respond spectrum in order to match the characteristic of the ground motion to the soil type. The scaled was depends on the fundamental period, T1 of the dam. The Koyna dam has been selected as a case study for the purpose of the analysis by assuming that no sliding and rigid foundation, has been estimated. IDA curves for Koyna dam developed for single and repeated ground motions and the performance level of the dam identifies. The IDA curve of repeated ground motion shown stiffer rather than single ground motion. The ultimate state displacement for a single event is 45.59mm and decreased to 39.33mm under repeated events which are decreased about 14%. This showed that the performance level of the dam based on seismic loadings depend on ground motion pattern.

Statistical analysis of global horizontal solar irradiation GHI in Fez city, Morocco

Science.gov (United States)

Bounoua, Z.; Mechaqrane, A.

2018-05-01

An accurate knowledge of the solar energy reaching the ground is necessary for sizing and optimizing the performances of solar installations. This paper describes a statistical analysis of the global horizontal solar irradiation (GHI) at Fez city, Morocco. For better reliability, we have first applied a set of check procedures to test the quality of hourly GHI measurements. We then eliminate the erroneous values which are generally due to measurement or the cosine effect errors. Statistical analysis show that the annual mean daily values of GHI is of approximately 5 kWh/m²/day. Daily monthly mean values and other parameter are also calculated.

Fate of Escherichia coli O26 in Corn Silage Experimentally Contaminated at Ensiling, at Silo Opening, or after Aerobic Exposure, and Protective Effect of Various Bacterial Inoculants▿

Science.gov (United States)

Dunière, Lysiane; Gleizal, Audrey; Chaucheyras-Durand, Frédérique; Chevallier, Isabelle; Thévenot-Sergentet, Delphine

2011-01-01

Shiga toxin-producing Escherichia coli (STEC) strains are responsible for human illness. Ruminants are recognized as a major reservoir of STEC, and animal feeds, such as silages, have been pointed out as a possible vehicle for the spread of STEC. The present study aimed to monitor the fate of pathogenic E. coli O26 strains in corn material experimentally inoculated (105 CFU/g) during ensiling, just after silo opening, and after several days of aerobic exposure. The addition of 3 bacterial inoculants, Propionibacterium sp., Lactobacillus buchneri, and Leuconostoc mesenteroides (106 CFU/g), was evaluated for their abilities to control these pathogens. The results showed that E. coli O26 could not survive in corn silage 5 days postensiling, and the 3 inoculants tested did not modify the fate of pathogen survival during ensiling. In the case of direct contamination at silo opening, E. coli O26 could be totally eradicated from corn silage previously inoculated with Leuconostoc mesenteroides. The combination of proper ensiling techniques and the utilization of selected bacterial inoculants appears to represent a good strategy to guarantee nutritional qualities of cattle feed while at the same time limiting the entry of pathogenic E. coli into the epidemiological cycle to improve the microbial safety of the food chain. PMID:21984243

Investigation of Magnetospheric Line Radiation above China

Science.gov (United States)

Sheng, X.; Wu, J.; Pu, X.

2017-12-01

Magnetospheric Line Radiation (MLR) is a kind of VLF emission that is considered by some researchers to be related with the power system on ground, and in frequency-time spectrograms of electromagnetic field, it has a line structure with large frequency bandwidth. These emission waves propagate through the magnetosphere and strongly interact with energetic electrons trapped in the earth's magnetic field. Such a wave-particle interaction amplifies the radiation and scatters energetic electrons, which may trigger new radiations. We detected 328 MLR events by analyzing the electric field data observed by DEMETER satellite in the space above China from the year of 2008 to 2010. Their characteristics and possible cause have been investigated systematically. There were more MLR events in daytime than in nighttime and more in winter than in summer. Such diurnal and seasonal differences were closely associated with whistlers and ionosphere conditions. Comparing Kp indices at the occurring time of MLR events and nationwide Kp indices through the analyzed years, we found these MLR events were not significantly dependent on geomagnetic activity. Most of events were distributed in the low latitude, while their peak intensities in frequency-time spectrograms seemed to be independent of latitude. The frequency intervals of MLR events were between 50 to 95Hz, and the frequency drifts were mostly in 0 0.4Hz/s. The above characteristics of MLR events were similar to those of Power Line Harmonic Radiation (PLHR) events observed in the space above China, therefore we inferred that these two emissions have close relation.

Field measurements of horizontal forward motion velocities of terrestrial dust devils: Towards a proxy for ambient winds on Mars and Earth

Science.gov (United States)

Balme, M. R.; Pathare, A.; Metzger, S. M.; Towner, M. C.; Lewis, S. R.; Spiga, A.; Fenton, L. K.; Renno, N. O.; Elliott, H. M.; Saca, F. A.; Michaels, T. I.; Russell, P.; Verdasca, J.

2012-11-01

Dust devils - convective vortices made visible by the dust and debris they entrain - are common in arid environments and have been observed on Earth and Mars. Martian dust devils have been identified both in images taken at the surface and in remote sensing observations from orbiting spacecraft. Observations from landing craft and orbiting instruments have allowed the dust devil translational forward motion (ground velocity) to be calculated, but it is unclear how these velocities relate to the local ambient wind conditions, for (i) only model wind speeds are generally available for Mars, and (ii) on Earth only anecdotal evidence exists that compares dust devil ground velocity with ambient wind velocity. If dust devil ground velocity can be reliably correlated to the ambient wind regime, observations of dust devils could provide a proxy for wind speed and direction measurements on Mars. Hence, dust devil ground velocities could be used to probe the circulation of the martian boundary layer and help constrain climate models or assess the safety of future landing sites. We present results from a field study of terrestrial dust devils performed in the southwest USA in which we measured dust devil horizontal velocity as a function of ambient wind velocity. We acquired stereo images of more than a 100 active dust devils and recorded multiple size and position measurements for each dust devil. We used these data to calculate dust devil translational velocity. The dust devils were within a study area bounded by 10 m high meteorology towers such that dust devil speed and direction could be correlated with the local ambient wind speed and direction measurements. Daily (10:00-16:00 local time) and 2-h averaged dust devil ground speeds correlate well with ambient wind speeds averaged over the same period. Unsurprisingly, individual measurements of dust devil ground speed match instantaneous measurements of ambient wind speed more poorly; a 20-min smoothing window applied to

Method for explosive expansion toward horizontal free faces for forming an in situ oil shale retort

Science.gov (United States)

Ricketts, Thomas E.

1980-01-01

Formation is excavated from within a retort site in formation containing oil shale for forming a plurality of vertically spaced apart voids extending horizontally across different levels of the retort site, leaving a separate zone of unfragmented formation between each pair of adjacent voids. Explosive is placed in each zone, and such explosive is detonated in a single round for forming an in situ retort containing a fragmented permeable mass of formation particles containing oil shale. The same amount of formation is explosively expanded upwardly and downwardly toward each void. A horizontal void excavated at a production level has a smaller horizontal cross-sectional area than a void excavated at a lower level of the retort site immediately above the production level void. Explosive in a first group of vertical blast holes is detonated for explosively expanding formation downwardly toward the lower void, and explosive in a second group of vertical blast holes is detonated in the same round for explosively expanding formation upwardly toward the lower void and downwardly toward the production level void for forming a generally T-shaped bottom of the fragmented mass.

A case study of air quality above an urban roof top vegetable farm.

Science.gov (United States)

Tong, Zheming; Whitlow, Thomas H; Landers, Andrew; Flanner, Benjamin

2016-01-01

The effect of elevation and rooftop configuration on local air quality was investigated at the Brooklyn Grange rooftop farm during a short-term observational campaign. Using multiple particle counters and sonic anemometers deployed along vertical gradients, we found that PM2.5 concentration decayed with height above the street. Samples adjacent to the street had the highest average PM2.5 concentration and frequent stochastic spikes above background. Rooftop observations 26 m above ground showed 7-33% reductions in average PM2.5 concentration compared with the curbside and had far fewer spikes. A relationship between the vertical extinction rate of PM2.5 and atmospheric stability was found whereby less unstable atmosphere and greater wind shear led to greater PM2.5 extinction due to damped vertical motion of air. Copyright © 2015 Elsevier Ltd. All rights reserved.

Performance of horizontal versus vertical vapor extraction wells

International Nuclear Information System (INIS)

Birdsell, K.H.; Roseberg, N.D.; Edlund, K.M.

1994-06-01

Vapor extraction wells used for site remediation of volatile organic chemicals in the vadose zone are typically vertical wells. Over the past few years, there has been an increased interest in horizontal wells for environmental remediation. Despite the interest and potential benefits of horizontal wells, there has been little study of the relative performance of horizontal and vertical vapor extraction wells. This study uses numerical simulations to investigate the relative performance of horizontal versus vertical vapor extraction wells under a variety of conditions. The most significant conclusion that can be drawn from this study is that in a homogeneous medium, a single, horizontal vapor extraction well outperforms a single, vertical vapor extraction well (with surface capping) only for long, linear plumes. Guidelines are presented regarding the use of horizontal wells

Implications of Nash Bargaining for Horizontal Industry Integration

OpenAIRE

Richard E. Just; Siddhartha Mitra; Sinaia Netanyahu

2005-01-01

This article shows how horizontal industry integration can arise from transferable asymmetry of technologies and endowments. The Nash bargaining solution suggests that greater technological diversity among coordinating parties yields greater gains from horizontal integration. The framework fits the case where a firm with a superior technology franchises the technology by horizontal integration. The results appear to fit hog production where integration has been primarily horizontal and, in pa...

Jerusalem artichoke above ground biomass

Energy Technology Data Exchange (ETDEWEB)

Lemieux, C.; Pageau, D.; Dubuc, J-P. [Agriculture and Agri-Food Canada, Ste. Foy, PQ (Canada)

1997-07-01

The possibility of using Jerusalem artichoke in an ethanol production scheme was discussed. A study was conducted to determine the yield stability, competitive ability and weed control requirements of this member of the sunflower family under the climatic conditions in eastern Canada. Two cultivars, the sunroot and fusil, were planted at four experimental sites in which three weed control treatments were tested (two arrowings, one arrowing, and no control). During the establishment, there was little difference between one and two arrowings, but the no weed control treatment was harmful to crop growth. It was concluded that Jerusalem artichoke is very competitive, and if it were included in an ethanol production scheme, weed control would only be necessary in the establishment year. After that, a single arrowing three to four weeks after planting would be sufficient to ensure proper establishment of the plant stand. 4 refs., 1 tab., 2 figs.

Early Site Permit Demonstration Program: Guidelines for determining design basis ground motions. Volume 2, Appendices

Energy Technology Data Exchange (ETDEWEB)

1993-03-18

This report develops and applies a methodology for estimating strong earthquake ground motion. The motivation was to develop a much needed tool for use in developing the seismic requirements for structural designs. An earthquake`s ground motion is a function of the earthquake`s magnitude, and the physical properties of the earth through which the seismic waves travel from the earthquake fault to the site of interest. The emphasis of this study is on ground motion estimation in Eastern North America (east of the Rocky Mountains), with particular emphasis on the Eastern United States and southeastern Canada. Eastern North America is a stable continental region, having sparse earthquake activity with rare occurrences of large earthquakes. While large earthquakes are of interest for assessing seismic hazard, little data exists from the region to empirically quantify their effects. The focus of the report is on the attributes of ground motion in Eastern North America that are of interest for the design of facilities such as nuclear power plants. This document, Volume II, contains Appendices 2, 3, 5, 6, and 7 covering the following topics: Eastern North American Empirical Ground Motion Data; Examination of Variance of Seismographic Network Data; Soil Amplification and Vertical-to-Horizontal Ratios from Analysis of Strong Motion Data From Active Tectonic Regions; Revision and Calibration of Ou and Herrmann Method; Generalized Ray Procedure for Modeling Ground Motion Attenuation; Crustal Models for Velocity Regionalization; Depth Distribution Models; Development of Generic Site Effects Model; Validation and Comparison of One-Dimensional Site Response Methodologies; Plots of Amplification Factors; Assessment of Coupling Between Vertical & Horizontal Motions in Nonlinear Site Response Analysis; and Modeling of Dynamic Soil Properties.

On the coupled unsaturated–saturated flow process induced by vertical, horizontal, and slant wells in unconfined aquifers

Directory of Open Access Journals (Sweden)

X. Liang

2017-03-01

established with special consideration of the coupled unsaturated–saturated flow process and the well orientation. Groundwater flow in the saturated zone is described by a three-dimensional governing equation and a linearized three-dimensional Richards' equation in the unsaturated zone. A solution in the Laplace domain is derived by the Laplace–finite-Fourier-transform and the method of separation of variables, and the semi-analytical solutions are obtained using a numerical inverse Laplace method. The solution is verified by a finite-element numerical model. It is found that the effects of the unsaturated zone on the drawdown of a pumping test exist at any angle of inclination of the pumping well, and this impact is more significant in the case of a horizontal well. The effects of the unsaturated zone on the drawdown are independent of the length of the horizontal well screen. The vertical well leads to the largest water volume drained from the unsaturated zone (W during the early pumping time, and the effects of the well orientation on W values become insignificant at the later time. The screen length of the horizontal well does not affect W for the whole pumping period. The proposed solutions are useful for the parameter identification of pumping tests with a general well orientation (vertical, horizontal, and slant in unconfined aquifers affected from above by the unsaturated flow process.

Research on Ground Motion Metal Target Based on Rocket Projectile by Using Millimeter Wave Radiometer Technology

Directory of Open Access Journals (Sweden)

Zhang Dongyang

2014-06-01

Full Text Available How to detect the ground motion metal target effectively is an important guarantee for precision strike in the process of Rocket Projectile flight. Accordingly and in view of the millimeter- wave radiation characteristic of the ground motion metal target, a mathematical model was established based on Rocket Projectile about millimeter-wave detection to the ground motion metal target. Through changing various parameters in the process of Rocket Projectile flight, the detection model was studied by simulation. The parameters variation and effective range of millimeter wave radiometer were obtained in the process of rotation and horizontal flight. So a certain theoretical basis was formed for the precision strike to the ground motion metal target.

Development of techniques for storing rough rice in cold regions, 1: Storage of rough rice at country elevator with natural heat radiation in winter

International Nuclear Information System (INIS)

Takekura, K.; Kawamura, S.; Itoh, K.

2003-01-01

An on-farm experiment in which 361 metric tons of rough rice was stored in a silo from November until July was conducted at a country elevator in Hokkaido to develop new techniques for storing rough rice in cold regions. The temperature of the rough rice near the inner silo wall decreased to below ice point (-5°C) due to natural heat radiation in winter, which the temperature of the rough rice in the center of the silo was maintained at almost the same temperature as that at the beginning of storage (5°C). Ventilation in the upper vacant space of the silo prevented moisture condensation on the inside surface of the silo during storage. When the cold rough rice was unloaded from the silo in summer, an unheated forced-air drier was used to increase the temperature of rough rice to above the dew point temperature of surrounding air. During the unloading and rewarming process, the moisture content of the rough rice increased due to moisture condensation on the grain from the air. However, the husks first absorbed the condensation and then the moisture slowly permeated into the brown rice kernel. Thus the rewarming process didn't cause any fissures in the brown rice. The results of the experiment indicate that condensation on rough rice doesn't give rise to any problems

Earthquake strong ground motion studies at the Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

Wong, Ivan; Silva, W.; Darragh, R.; Stark, C.; Wright, D.; Jackson, S.; Carpenter, G.; Smith, R.; Anderson, D.; Gilbert, H.; Scott, D.

1989-01-01

Site-specific strong earthquake ground motions have been estimated for the Idaho National Engineering Laboratory assuming that an event similar to the 1983 M s 7.3 Borah Peak earthquake occurs at epicentral distances of 10 to 28 km. The strong ground motion parameters have been estimated based on a methodology incorporating the Band-Limited-White-Noise ground motion model coupled with Random Vibration Theory. A 16-station seismic attenuation and site response survey utilizing three-component portable digital seismographs was also performed for a five-month period in 1989. Based on the recordings of regional earthquakes, the effects of seismic attenuation in the shallow crust and along the propagation path and local site response were evaluated. This data combined with a detailed geologic profile developed for each site based principally on borehole data, was used in the estimation of the strong ground motion parameters. The preliminary peak horizontal ground accelerations for individual sites range from approximately 0.15 to 0.35 g. Based on the authors analysis, the thick sedimentary interbeds (greater than 20 m) in the basalt section attenuate ground motions as speculated upon in a number of previous studies

Nutrient cycling and Above- and Below-ground Interactions in a Runoff Agroforestry System Applied with Composted Tree Trimmings

Science.gov (United States)

Ilani, Talli; Ephrath, Jhonathan; Silberbush, Moshe; Berliner, Pedro

2014-05-01

The primary production in arid zones is limited due to shortage of water and nutrients. Conveying flood water and storing it in plots surrounded by embankments allows their cropping. The efficient exploitation of the stored water can be achieved through an agroforestry system, in which two crops are grown simultaneously: annual crops with a shallow root system and trees with a deeper root system. We posit that the long-term productivity of this system can be maintained by intercropping symbiotic N fixing shrubs with annual crops, and applying the pruned and composted shrub leaves to the soil, thus ensuring an adequate nitrogen level (a limiting factor in drylands) in the soil. To test our hypothesis we carried a two year trial in which fast-growing acacia (A. saligna) trees were the woody component and maize (Zea mays L.) the intercrop. Ten treatments were applied over two maize growth seasons to examine the below- and above-ground effects of tree pruning, compost application and interactions. The addition of compost in the first growth season led to an increase of the soil organic matter reservoir, which was the main N source for the maize during the following growth season. In the second growth season the maize yield was significantly higher in the plots to which compost was applied. Pruning the tree's canopies changed the trees spatial and temporal root development, allowing the annual crop to develop between the trees. The roots of pruned trees intercropped with maize penetrated deeper in the soil. The intercropping of maize within pruned trees and implementing compost resulted in a higher water use efficiency of the water stored in the soil when compared to the not composted and monoculture treatments. The results presented suggest that the approach used in this study can be the basis for achieving sustainable agricultural production under arid conditions.

Derivation of the RPA (Random Phase Approximation) Equation of ATDDFT (Adiabatic Time Dependent Density Functional Ground State Response Theory) from an Excited State Variational Approach Based on the Ground State Functional.

Science.gov (United States)

Ziegler, Tom; Krykunov, Mykhaylo; Autschbach, Jochen

2014-09-09

The random phase approximation (RPA) equation of adiabatic time dependent density functional ground state response theory (ATDDFT) has been used extensively in studies of excited states. It extracts information about excited states from frequency dependent ground state response properties and avoids, thus, in an elegant way, direct Kohn-Sham calculations on excited states in accordance with the status of DFT as a ground state theory. Thus, excitation energies can be found as resonance poles of frequency dependent ground state polarizability from the eigenvalues of the RPA equation. ATDDFT is approximate in that it makes use of a frequency independent energy kernel derived from the ground state functional. It is shown in this study that one can derive the RPA equation of ATDDFT from a purely variational approach in which stationary states above the ground state are located using our constricted variational DFT (CV-DFT) method and the ground state functional. Thus, locating stationary states above the ground state due to one-electron excitations with a ground state functional is completely equivalent to solving the RPA equation of TDDFT employing the same functional. The present study is an extension of a previous work in which we demonstrated the equivalence between ATDDFT and CV-DFT within the Tamm-Dancoff approximation.

Use of tree-ring chemistry to document historical ground-water contamination events

Science.gov (United States)

Vroblesky, Don A.; Yanosky, Thomas M.

1990-01-01

The annual growth rings of tulip trees (Liriodendron tulipifera L.) appear to preserve a chemical record of ground-water contamination at a landfill in Maryland. Zones of elevated iron and chlorine concentrations in growth rings from trees immediately downgradient from the landfill are closely correlated temporally with activities in the landfill expected to generate iron and chloride contamination in the ground water. Successively later iron peaks in trees increasingly distant from the landfill along the general direction of ground-water flow imply movement of iron-contaminated ground water away from the landfill. The historical velocity of iron movement (2 to 9 m/yr) and chloride movement (at least 40 m/yr) in ground water at the site was estimated from element-concentration trends of trees at successive distances from the landfill. The tree-ring-derived chloride-transport velocity approximates the known ground-water velocity (30 to 80 m/yr). A minimum horizontal hydraulic conductivity (0.01 to .02 cm/s) calculated from chloride velocity agrees well with values derived from aquifer tests (about 0.07 cm/s) and from ground-water modeling results (0.009 to 0.04 cm/s).

Geological-geotechnical investigation for large horizontal directional drilling

Energy Technology Data Exchange (ETDEWEB)

Martins, Pedro R.R.; Rocha, Ronaldo; Avesani Neto, Jose Orlando; Placido, Rafael R.; Ignatius, Scandar G.; Galli, Vicente Luiz [Instituto de Pesquisas Tecnologicas do Estado de Sao Paulo (IPT), Sao Paulo, SP (Brazil); Amaral, Claudio S. [Centro de Pesquisa Leopoldo A. Miguez de Melo (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil)

2009-07-01

Use of Horizontal Directional Drilling - HDD for large diameter (OD>20 inches) pipeline installation started in the second half of the seventies. Since then the method became the preferred alternative for situations in which it is necessary an underground pipeline but there are concerns about digging trenches. Crossings of roadways, water bodies and environmental sensitive areas are typical examples of its application. Technical and economic feasibility of HDD depends significantly on the properties of the materials that will be drilled. Lack of information about these materials can lead to several problems as: schedule delays, cost elevation, pipeline damage, unforeseen environmental impacts and even the failure of the entire operation. Ground investigation campaigns for HDD should define a consistent geological-geotechnical model, which must include determination of behaviour parameters for soil and rock masses that will be drilled. Thus it is proposed an investigation in tree stages: review of available geological-geotechnical information, site reconnaissance, and field survey. (author)

Estimation of the Above Ground Biomass of Tropical Forests using Polarimetric and Tomographic SAR Data Acquired at P Band and 3-D Imaging Techniques

Science.gov (United States)

Ferro-Famil, L.; El Hajj Chehade, B.; Ho Tong Minh, D.; Tebaldini, S.; LE Toan, T.

2016-12-01

Developing and improving methods to monitor forest biomass in space and time is a timely challenge, especially for tropical forests, for which SAR imaging at larger wavelength presents an interesting potential. Nevertheless, directly estimating tropical forest biomass from classical 2-D SAR images may reveal a very complex and ill-conditioned problem, since a SAR echo is composed of numerous contributions, whose features and importance depend on many geophysical parameters, such has ground humidity, roughness, topography… that are not related to biomass. Recent studies showed that SAR modes of diversity, i.e. polarimetric intensity ratios or interferometric phase centers, do not fully resolve this under-determined problem, whereas Pol-InSAR tree height estimates may be related to biomass through allometric relationships, with, in general over tropical forests, significant levels of uncertainty and lack of robustness. In this context, 3-D imaging using SAR tomography represents an appealing solution at larger wavelengths, for which wave penetration properties ensures a high quality mapping of a tropical forest reflectivity in the vertical direction. This paper presents a series of studies led, in the frame of the preparation of the next ESA mission BIOMASS, on the estimation of biomass over a tropical forest in French Guiana, using Polarimetric SAR Tomographic (Pol-TomSAR) data acquired at P band by ONERA. It is then shown that Pol-TomoSAR significantly improves the retrieval of forest above ground biomass (AGB) in a high biomass forest (200 up to 500 t/ha), with an error of only 10% at 1.5-ha resolution using a reflectivity estimates sampled at a predetermined elevation. The robustness of this technique is tested by applying the same approach over another site, and results show a similar relationship between AGB and tomographic reflectivity over both sites. The excellent ability of Pol-TomSAR to retrieve both canopy top heights and ground topography with an error

Small horizontal emittance in the TESLA damping ring

International Nuclear Information System (INIS)

Decking, W.

2001-01-01

The present TESLA damping ring is designed for a normalized horizontal emittance of 8x10 -6 m. γ-γ collisions at the TESLA linear collider will benefit from a further decrease of the horizontal emittance. This paper reviews the processes which limit the horizontal emittance in the damping ring. Preliminary estimates on the smallest horizontal emittance for the present TESLA damping ring design as well as an ultimate limit of the emittance reachable with the TESLA damping ring concept will be given

Mud peeling and horizontal crack formation in drying clays

KAUST Repository

Style, Robert W.

2011-03-01

Mud peeling is a common phenomenon whereby horizontal cracks propagate parallel to the surface of a drying clay. Differential stresses then cause the layer of clay above the crack to curl up to form a mud peel. By treating the clay as a poroelastic solid, we analyze the peeling phenomenon and show that it is caused by the gradient in tensile stress at the surface of the clay, analogously to the spalling of thermoelastic materials. For a constant water evaporation rate at the clay surface we derive equations for the depth of peeling and the time of peeling as functions of the evaporation rate. Our model predicts a simple relationship between the radius of curvature of a mud peel and the depth of peeling. The model predictions are in agreement with the available experimental data. Copyright 2011 by the American Geophysical Union.

Experimental Investigation of a Lift Augmented Ground Effect Platform

National Research Council Canada - National Science Library

Igue, Roberto T

2005-01-01

.... Lift, torque and efficiency were measured and calculated for each setting. Pressure and velocity information was also collected at specific points around the craft when operating at different heights above ground...

3_D modeling using TLS and GPR techniques to characterize above and below-ground wood distribution in pyroclastic deposits along the Blanco River (Chilean Patagonia)

Science.gov (United States)

Valdebenito, Galo; Tonon, Alessia; Iroume, Andrés; Alvarado, David; Fuentes, Carlos; Picco, Lorenzo; Lenzi, Mario

2016-04-01

To date, the study of in-stream wood in rivers has been focused mainly on quantifying wood pieces deposited above the ground. However, in some particular river systems, the presence of buried dead wood can also represent an important component of wood recruitment and budgeting dynamics. This is the case of the Blanco River (Southern Chile) severely affected by the eruption of Chaitén Volcano occurred between 2008 and 2009. The high pyroclastic sediment deposition and transport affected the channel and the adjacent forest, burying wood logs and standing trees. The aim of this contribution is to assess the presence and distribution of wood in two study areas (483 m2 and 1989 m2, respectively) located along the lower streambank of the Blanco River, and covered by thick pyroclastic deposition up to 5 m. The study areas were surveyed using two different devices, a Terrestrial Laser Scanner (TLS) and a Ground Penetrating Radar (GPR). The first was used to scan the above surface achieving a high point cloud density (≈ 2000 points m-2) which allowed us to identify and measure the wood volume. The second, was used to characterize the internal morphology of the volcanic deposits and to detect the presence and spatial distribution of buried wood up to a depth of 4 m. Preliminary results have demonstrated differences in the numerousness and volume of above wood between the two study areas. In the first one, there were 43 wood elements, 33 standing trees and 10 logs, with a total volume of 2.96 m3 (109.47 m3 km-1), whereas the second one was characterized by the presence of just 7 standing trees and 11 wood pieces, for a total amount of 0.77 m3 (7.73 m3 km-1). The dimensions of the wood elements vary greatly according to the typology, standing trees show the higher median values in diameter and length (0.15 m and 2.91 m, respectively), whereas the wood logs were smaller (0.06 m and 1.12 m, respectively). The low dimensions of deposited wood can be probably connected to their

Structural, physiognomic and above-ground biomass variation in savanna–forest transition zones on three continents – how different are co-occurring savanna and forest formations?

Directory of Open Access Journals (Sweden)

E. M. Veenendaal

2015-05-01

Full Text Available Through interpretations of remote-sensing data and/or theoretical propositions, the idea that forest and savanna represent "alternative stable states" is gaining increasing acceptance. Filling an observational gap, we present detailed stratified floristic and structural analyses for forest and savanna stands located mostly within zones of transition (where both vegetation types occur in close proximity in Africa, South America and Australia. Woody plant leaf area index variation was related to tree canopy cover in a similar way for both savanna and forest with substantial overlap between the two vegetation types. As total woody plant canopy cover increased, so did the relative contribution of middle and lower strata of woody vegetation. Herbaceous layer cover declined as woody cover increased. This pattern of understorey grasses and herbs progressively replaced by shrubs as the canopy closes over was found for both savanna and forests and on all continents. Thus, once subordinate woody canopy layers are taken into account, a less marked transition in woody plant cover across the savanna–forest-species discontinuum is observed compared to that inferred when trees of a basal diameter > 0.1 m are considered in isolation. This is especially the case for shrub-dominated savannas and in taller savannas approaching canopy closure. An increased contribution of forest species to the total subordinate cover is also observed as savanna stand canopy closure occurs. Despite similarities in canopy-cover characteristics, woody vegetation in Africa and Australia attained greater heights and stored a greater amount of above-ground biomass than in South America. Up to three times as much above-ground biomass is stored in forests compared to savannas under equivalent climatic conditions. Savanna–forest transition zones were also found to typically occur at higher precipitation regimes for South America than for Africa. Nevertheless, consistent across all three

Study of radial distribution of 239,240Pu and 90Sr in annual tree rings and trunk bark of a 103 years old Norway spruce at four different heights above ground

International Nuclear Information System (INIS)

Holgye, Z.; Schlesingerova, E.

2016-01-01

Radial distribution of 239,240 Pu and 90 Sr originating from atmospheric nuclear tests in tree rings and trunk bark at heights of 1.3, 10, 18 and 22 m above ground was studied. 239,240 Pu activity concentrations in air dried tree ring samples (each containing 10 annual rings) at all heights were under detection limit of the used method. 90 Sr activity concentrations in tree ring samples ranged from 0.54 to 2.81 Bq kg -1 . 239,240 Pu and 90 Sr were present in the trunk bark. The paper presents data for 239,240 Pu and 90 Sr aggregated transfer factors to tree trunk. (author)

Modelling horizontal and vertical concentration profiles of ozone and oxides of nitrogen within high-latitude urban areas

International Nuclear Information System (INIS)

Nicholson, J.P.; Weston, K.J.

2001-01-01

Urban ozone concentrations are determined by the balance between ozone destruction, chemical production and supply through advection and turbulent down-mixing from higher levels. At high latitudes, low levels of solar insolation and high horizontal advection speeds reduce the photochemical production and the spatial ozone concentration patterns are largely determined by the reaction of ozone with nitric oxide and dry deposition to the surface. A Lagrangian column model has been developed to simulate the mean (monthly and annual) three-dimensional structure in ozone and nitrogen oxides (NO x ) concentrations in the boundary-layer within and immediately around an urban area. The short-time-scale photochemical processes of ozone and NO x , as well as emissions and deposition to the ground, are simulated. The model has a horizontal resolution of 1x1km and high resolution in the vertical. It has been applied over a 100x100km domain containing the city of Edinburgh (at latitude 56 o N) to simulate the city-scale processes of pollutants. Results are presented, using averaged wind-flow frequencies and appropriate stability conditions, to show the extent of the depletion of ozone by city emissions. The long-term average spatial patterns in the surface ozone and NO x concentrations over the model domain are reproduced quantitatively. The model shows the average surface ozone concentrations in the urban area to be lower than the surrounding rural areas by typically 50% and that the areas experiencing a 20% ozone depletion are generally restricted to within the urban area. The depletion of the ozone concentration to less than 50% of the rural surface values extends only 20m vertically above the urban area. A series of monitoring sites for ozone, nitric oxide and nitrogen dioxide on a north-south transect through the city - from an urban, through a semi-rural, to a remote rural location - allows the comparison of modelled with observed data for the mean diurnal cycle of ozone

Spondylolysis and the sacro-horizontal angle in athletes

International Nuclear Information System (INIS)

Swaerd, L.; Hellstroem, M.; Jacobsson, B.; Peterson, L.; Sahlgrenska Sjukhuset, Goeteborg; King Faisal Specialist Hospital and Research Centre, Riyadh

1989-01-01

The frequency of spondylolysis and the relationship between spondylolysis and the sacro-horizontal angle in 143 athletes and 30 non-athletes is reported. Athletes had a larger sacro-horizontal angle than non-athletes. The sacro-horizontal angle was larger in athletes with spondylolysis as compared with those without. An increased incidence of spondylolysis with an increased angle was demonstrated. It is suggested that an increased sacro-horizontal angle may predispose to spondylolysis, especially in combination with the high mechanical loads sustained in certain sports. (orig.)

Spondylolysis and the sacro-horizontal angle in athletes

Energy Technology Data Exchange (ETDEWEB)

Swaerd, L.; Hellstroem, M.; Jacobsson, B.; Peterson, L. (Oestra Sjukhuset, Goeteborg (Sweden). Dept. of Orthopaedics; Sahlgrenska Sjukhuset, Goeteborg (Sweden). Dept. of Diagnostic Radiology; King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Dept. of Radiology)

The frequency of spondylolysis and the relationship between spondylolysis and the sacro-horizontal angle in 143 athletes and 30 non-athletes is reported. Athletes had a larger sacro-horizontal angle than non-athletes. The sacro-horizontal angle was larger in athletes with spondylolysis as compared with those without. An increased incidence of spondylolysis with an increased angle was demonstrated. It is suggested that an increased sacro-horizontal angle may predispose to spondylolysis, especially in combination with the high mechanical loads sustained in certain sports. (orig.).

Identification of Natural Frequency of Low Rise Building on Soft Ground Profile using Ambient Vibration Method

Science.gov (United States)

Kamarudin, A. F.; Zainal Abidin, M. H.; Mokhatar, S. N.; Daud, M. E.; Ibrahim, A.; Ibrahim, Z.; Noh, M. S. Md

2018-04-01

Natural frequency is the rate at which a body to vibrate or oscillate. Application of ambient vibration (AV) excitation is widely used nowadays as the input motion for building predominant frequency, fo, and ground fundamental frequency, Fo, prediction due to simple, fast, non-destructive, simple handling operation and reliable result. However, it must be emphasized and caution to isolate these frequencies (fo and Fo) from spurious frequencies of site-structure effects especially to low rise building on soft ground deposit. In this study, identification of fo and Fo by using AV measurements were performed on ground and 4-storey primary school reinforced concrete (RC) building at Sekolah Kebangsaan (SK) Sg. Tongkang, Rengit, Johor using 1 Hz of tri-axial seismometer sensor. Overlapping spectra between Fourier Amplitude Spectra (FAS) from and Horizontal to Vertical Spectra Ratio (HVSR) were used to distinguish respective frequencies of building and ground natural frequencies. Three dominant frequencies were identified from the FAS curves at 1.91 Hz, 1.98 Hz and 2.79 Hz in longitudinal (East West-EW), transverse (North South-NS) and vertical (UD) directions. It is expected the building has deformed in translational mode based on the first peak frequency by respective NS and EW components of FAS spectrum. Vertical frequency identified from the horizontal spectrums, might induces to the potential of rocking effect experienced by the school building. Meanwhile, single peak HVSR spectrum at low ground fundamental frequency concentrated at 0.93 Hz indicates to the existence deep contrast of soft deposit. Strong interaction between ground and building at similar frequency (0.93 Hz) observed from the FAS curves on the highest floor has shown the building to behave as a dependent unit against ground response as one rigid mass.

Broadband Ground Motion Reconstruction for the Kanto Basin during the 1923 Kanto Earthquake

Science.gov (United States)

Sekiguchi, Haruko; Yoshimi, Masayuki

2011-03-01

Ground motions of the 1923 Kanto Earthquake inside the Kanto Basin are numerically simulated in a wide frequency range (0-10 Hz) based on new knowledge of the earthquake's source processes, the sedimentary structure of the basin, and techniques for generating broadband source models of great earthquakes. The Kanto Earthquake remains one of the most important exemplars for ground motion prediction in Japan due to its size, faulting geometry, and location beneath the densely populated Kanto sedimentary basin. We reconstruct a broadband source model of the 1923 Kanto Earthquake from inversion results by introducing small-scale heterogeneities. The corresponding ground motions are simulated using a hybrid technique comprising the following four calculations: (1) low-frequency ground motion of the engineering basement, modeled using a finite difference method; (2) high-frequency ground motion of the engineering basement, modeled using a stochastic Green's function method; (3) total ground motion of the engineering basement (i.e. 1 + 2); and (4) ground motion at the surface in response to the total basement ground motion. We employ a recently developed three-dimensional (3D) velocity structure model of the Kanto Basin that incorporates prospecting data, microtremor observations and measurements derived from strong ground motion records. Our calculations reveal peak ground velocities (PGV) exceeding 50 cm/s in the area above the fault plane: to the south, where the fault plane is shallowest, PGV reaches 150-200 cm/s at the engineering basement and 200-250 cm/s at the surface. Intensity 7, the maximum value in the Japan Meteorological Agency's intensity scale, is calculated to have occurred widely in Sagami Bay, which corresponds well with observed house-collapse rates due to the 1923 event. The modeling reveals a pronounced forward directivity effect for the area lying above the southern, shallow part of the fault plane. The high PGV and intensity seen above the

Horizontal alveolar bone loss: A periodontal orphan

Science.gov (United States)

Jayakumar, A.; Rohini, S.; Naveen, A.; Haritha, A.; Reddy, Krishnanjeneya

2010-01-01

Background: Attempts to successfully regenerate lost alveolar bone have always been a clinician’s dream. Angular defects, at least, have a fairer chance, but the same cannot be said about horizontal bone loss. The purpose of the present study was to evaluate the prevalence of horizontal alveolar bone loss and vertical bone defects in periodontal patients; and later, to correlate it with the treatment modalities available in the literature for horizontal and vertical bone defects. Materials and Methods: The study was conducted in two parts. Part I was the radiographic evaluation of 150 orthopantomographs (OPGs) (of patients diagnosed with chronic periodontitis and seeking periodontal care), which were digitized and read using the AutoCAD 2006 software. All the periodontitis-affected teeth were categorized as teeth with vertical defects (if the defect angle was ≤45° and defect depth was ≥3 mm) or as having horizontal bone loss. Part II of the study comprised search of the literature on treatment modalities for horizontal and vertical bone loss in four selected periodontal journals. Results: Out of the 150 OPGs studied, 54 (36%) OPGs showed one or more vertical defects. Totally, 3,371 teeth were studied, out of which horizontal bone loss was found in 3,107 (92.2%) teeth, and vertical defects were found only in 264 (7.8%) of the teeth, which was statistically significant (P<.001). Search of the selected journals revealed 477 papers have addressed the treatment modalities for vertical and horizontal types of bone loss specifically. Out of the 477 papers, 461 (96.3%) have addressed vertical bone loss, and 18 (3.7%) have addressed treatment options for horizontal bone loss. Two papers have addressed both types of bone loss and are included in both categories. Conclusion: Horizontal bone loss is more prevalent than vertical bone loss but has been sidelined by researchers as very few papers have been published on the subject of regenerative treatment modalities for

Estimating the Above-Ground Biomass in Miombo Savanna Woodlands (Mozambique, East Africa Using L-Band Synthetic Aperture Radar Data

Directory of Open Access Journals (Sweden)

Maria J. Vasconcelos

2013-03-01

Full Text Available The quantification of forest above-ground biomass (AGB is important for such broader applications as decision making, forest management, carbon (C stock change assessment and scientific applications, such as C cycle modeling. However, there is a great uncertainty related to the estimation of forest AGB, especially in the tropics. The main goal of this study was to test a combination of field data and Advanced Land Observing Satellite (ALOS Phased Array L-band Synthetic Aperture Radar (PALSAR backscatter intensity data to reduce the uncertainty in the estimation of forest AGB in the Miombo savanna woodlands of Mozambique (East Africa. A machine learning algorithm, based on bagging stochastic gradient boosting (BagSGB, was used to model forest AGB as a function of ALOS PALSAR Fine Beam Dual (FBD backscatter intensity metrics. The application of this method resulted in a coefficient of correlation (R between observed and predicted (10-fold cross-validation forest AGB values of 0.95 and a root mean square error of 5.03 Mg·ha−1. However, as a consequence of using bootstrap samples in combination with a cross validation procedure, some bias may have been introduced, and the reported cross validation statistics could be overoptimistic. Therefore and as a consequence of the BagSGB model, a measure of prediction variability (coefficient of variation on a pixel-by-pixel basis was also produced, with values ranging from 10 to 119% (mean = 25% across the study area. It provides additional and complementary information regarding the spatial distribution of the error resulting from the application of the fitted model to new observations.

comparative evaluation of pressure distribution between horizontal

African Journals Online (AJOL)

user

This paper presents comparative analysis between the pressure behavior of ... Green and source function were used to evaluate the performance of horizontal well and ..... Superscript. ' derivative. D = dimensionless. h = horizontal. = change.

A status report on artificial lift systems and challenges in North Dakota horizontal completions

Energy Technology Data Exchange (ETDEWEB)

Fangmeier, K. [Amerada Hess Corp., ND (United States)

2005-07-01

Partially pressure depleted reservoirs and unfavorable horizontal flow geometries can impact artificial lift designs and diagnostics. In addition, terrain slugging, drilling fines, high gas volume fractions, H{sub 2}S gas and high bottom hole temperatures also pose challenges. This paper provides an overview of various systems utilized by Amerada Hess, a company which examines methods of reducing gas lift gas volumes to achieve maximum flow. A description of naturally fractured reservoirs and limited natural fractures was provided. A comparison was presented between the original conditions at Beaver Lodge Madison and existing conditions with horizontal development. Various artificial lift challenges were examined. It was suggested that high volume lift utilizing gas lift was the preferred artificial lift system for high volume wells. It was noted that downhole sensors can be used as an indicator of potential run life. However, reliability is limited by downhole operating temperatures and electrical ground faults. A comparison of friendly and unfriendly flow systems was presented, as well as a gas lift pressure chart. A summary of average gas volume systems was provided as well as an example of a response to increase drawdown. Examples of downhole Electric Submersible Pump (ESP) sensors were provided, as well as possible flowing pressure profiles in horizontal completion because of the constraints of lift capacity. It was concluded that a single point injection and proven gas lift system is the next step in high volume lift strategy. 2 tabs, 16 figs.

The development of Canadian leadership in horizontal drilling technology

Energy Technology Data Exchange (ETDEWEB)

Hawkins, J R

1989-01-01

Horizontal wells are of increasing interest in the oil and gas industry, as is evident from the increase in the numbers of such wells being drilled. Horizontal well technology is used to improve production rates, notably in low permeability formations; to capture reserves if a reservoir is not economic using non-horizontal wells; to manage breakthrough of sweep fluids and increase sweep efficiency; and to extend the areal reach from a single surface location, especially in offshore production. The types of horizontal wells, differentiated on the basis of how quickly the well becomes horizontal, are briefly outlined and a short history of horizontal wells is presented. Canadian accomplishments in this field are then described, including steerable drilling systems, measurement-while-drilling systems, management of hole drag and torque, and well completion techniques. About 25 horizontal wells are forecast to be drilled in Canada in 1989, indicating the favorable future of this technology. 2 figs., 5 tabs.

Low-impact sampling under an active solid low-level radioactive waste disposal unit using horizontal drilling technology

International Nuclear Information System (INIS)

Puglisi, C.V.; Vold, E.L.

1995-01-01

The purpose of this project was to determine the performance of the solid low-level radioactive waste (LLRW) disposal units located on a mesa top at TA-54, Area G, Los Alamos National Laboratory (LANL), Los Alamos, NM, and to provide in-situ (vadose zone) site characterization information to Area G's Performance Assessment. The vadose zone beneath an active disposal unit (DU 37), was accessed by utilizing low-impact, air-rotary horizontal drilling technology. Core samples were pulled, via wire-line core method, in 3 horizontal holes fanning out below DU 37 at approximately 5 foot intervals depending on recovery percentage. Samples were surveyed and prepared in-field following Environmental Restoration (ER) guidelines. Samples were transferred from the field to the CST-9 Radvan for initial radiological screening. Following screening, samples were delivered to CST-3 analytical lab for analyses including moisture content, 23 inorganics, 60 volatile organic compounds (VOC's), 68 semivolatile organic compounds (SVOC's), tritium, lead 210, radium 226 ampersand 228, cesium 137, isotopic plutonium, americium 241, strontium 90, isotopic uranium, and isotopic thorium. Other analyses included matric potential, alpha spectroscopy, gamma spectroscopy, and gross alpha/beta. The overall results of the analysis identified only tritium as having migrated from the DU. Am-241, Eu-152, and Pu-238 were possibly identified above background but the results are not definitive. Of all organics analysed for, only ethyl acetate was tentatively identified slightly above background. All inorganics were found to be well below regulatory limits. Based on the results of the above mentioned analyses, it was determined that Area G's disposal units are performing well and no significant liquid phase migration of contaminants has occurred

Communications construction on mining grounds influenced by mining damage. Budownictwo komunikacyjne na terenach objetych szkodami gorniczymi

Energy Technology Data Exchange (ETDEWEB)

Rosikon, A

1979-01-01

This book considers problems associated with construction of communication lines on grounds influenced by underground coal mining. It is stated that about 50% of coal mined in Poland comes from protective coal pillars. Improving methods of strata control and ground control after underground mining will influence perspectives of mining in protective pillars. The following problems associated with minimizing mining damage are analyzed: types of ground deformation caused by underground mining, continuous and discontinuous deformation, factors which influence formation of subsidence troughs, forecasting ground subsidence according to the Knothe and Budryk theory, horizontal and vertical ground dislocation, coefficients used for description of ground deformation, Kochmanski's theory of continuous deformation, effects of ground subsidence of foundations of buildings and industrial structures, construction of roads, railway tracks and other communication lines on ground influenced by discontinuous deformations caused by coal mining, problems associated with construction of bridges and tunnels, construction of sewage systems, effects of underground mining on maintenance and repair of communication lines and sewage systems. Ways of minimizing discontinuous ground deformation are analyzed.

The horizontal plane appearances of scoliosis

DEFF Research Database (Denmark)

Illés, Tamás S.; Burkus, Máté; Somoskeőy, Szabolcs

2017-01-01

Purpose: A posterior-anterior vertebral vector is proposed to facilitate visualization and understanding of scoliosis. The aim of this study was to highlight the interest of using vertebral vectors, especially in the horizontal plane, in clinical practice. Methods: We used an EOS two-/three-dimen......Purpose: A posterior-anterior vertebral vector is proposed to facilitate visualization and understanding of scoliosis. The aim of this study was to highlight the interest of using vertebral vectors, especially in the horizontal plane, in clinical practice. Methods: We used an EOS two...... cases of a normal spine and a thoracic scoliosis are presented. Results: For a normal spine, vector projections in the transverse plane are aligned with the posterior-anterior anatomical axis. For a scoliotic spine, vector projections in the horizontal plane provide information on the lateral...... decompensation of the spine and the lateral displacement of vertebrae. In the horizontal plane view, vertebral rotation and projections of the sagittal curves can also be analyzed simultaneously. Conclusions: The use of posterior-anterior vertebral vector facilitates the understanding of the 3D nature...

The first fermi-lat catalog of sources above 10 GeV

Energy Technology Data Exchange (ETDEWEB)

Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Belfiore, A.; Bellazzini, R.; Bernieri, E.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Campana, R.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chaves, R. C. G.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D' Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Desiante, R.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Franckowiak, A.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hewitt, J.; Hill, A. B.; Horan, D.; Hughes, R. E.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Kataoka, J.; Kawano, T.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Massaro, E.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Okumura, A.; Orienti, M.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Ritz, S.; Romani, R. W.; Roth, M.; Saz Parkinson, P. M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stawarz, Łukasz; Strong, A. W.; Suson, D. J.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Werner, M.; Winer, B. L.; Wood, K. S.; Wood, M.

2013-11-14

We present a catalog of gamma-ray sources at energies above 10 GeV based on data from the Large Area Telescope (LAT) accumulated during the first three years of the Fermi Gamma-ray Space Telescope mission. The first Fermi-LAT catalog of >10GeV sources (1FHL) has 514 sources. For each source we present location, spectrum, a measure of variability, and associations with cataloged sources at other wavelengths. We found that 449 (87%) could be associated with known sources, of which 393 (76% of the 1FHL sources) are active galactic nuclei. Of the 27 sources associated with known pulsars, we find 20 (12) to have significant pulsations in the range >10GeV (>25GeV). In this work we also report that, at energies above 10 GeV, unresolved sources account for 27+/-8 % of the isotropic gamma-ray background, while the unresolved Galactic population contributes only at the few percent level to the Galactic diffuse background. We also highlight the subset of the 1FHL sources that are best candidates for detection at energies above 50-100 GeV with current and future ground-based gamma-ray observatories.

Measurement protocol for radon measurements in workplaces above ground

International Nuclear Information System (INIS)

Mjoenes, L.; Soederman, A.-L.

2004-01-01

measurement made during the warmer part of the year is likely to show radon levels that are not representative for the whole year. Measurements have to cover at least 20 % of the rooms used for work places situated on the ground floor, in upper floors one measurement per floor has to be made and at least one per 500 m 2 . More measurements are recommended for buildings constructed from material with enhanced uranium and radium levels, such as blue lightweight concrete. Rooms in upper floors with vertical piping or other vertical openings through the building or rooms adjacent to rooms with piping should be measured. The detectors should not be moved during the measurement period and they should be placed so that the result is representative for the work place. Measurement devises must be calibrated every 12 months. This can be done at SSI or another laboratory recommended by SSI. Laboratories, consulting firms etc responsible for radon measurements have to guarantee that the results are correct. A quality system is required in order to perform measurements. The measurement protocol describes every method that can be used for radon measurements in detail as far as calibration and control systems are concerned. (author)

Analysis of Gas Vent System in Overseas LILW Disposal Facilities

Energy Technology Data Exchange (ETDEWEB)

Kim, Ju Yub; Kim, Ju Youl [FNC Technology Co., Yongin (Korea, Republic of); Jung, Hae Ryong; Ha, Jae Chul [Korea Radioactive Waste Management Corporation, Daejeon (Korea, Republic of)

2012-05-15

A Low- and Intermediate-Level Radioactive Waste (LILW) disposal facility is currently under construction in Korea. It is located in the aquifer, 80{approx}130 m below the ground surface. Thus, it is expected that disposal facility will be saturated after closure and various gases will be generated from metal corrosion, microbial degradation of organic materials and radiolysis. Generated gases will move up to the upper part of the silo, and it will increase the pressure of the silo. Since the integrity of the engineered barrier could be damaged, development of effective gas vent system which can prevent the gas accumulation in the silo is essential. In order to obtain basic data needed to develop site-specific gas vent system, gas vent systems of Sweden, Finland and Switzerland, which have the disposal concept of underground facility, were analyzed

Source and ground-motion parameters of the 2011 Lorca earthquake; Parametros de la fuente y del movimiento del suelo del terremoto de Lorca de 2011

Energy Technology Data Exchange (ETDEWEB)

Alguacil de la Blanca, G.; Vidal Sanchez, F.; Stich, D.; Mancilla Perez, F. L.; Lopez Comino, J. A.; Morales Soto, J.; Navarro Bernal, M.

2012-07-01

113 events of the Lorca seismic series has been relocated by using Double difference algorithm and data from both temporary and permanent seismic networks. Relocations yield shallow hypo central distribution of aftershocks with a {approx}5 km long, NE-SW trending, placed SW of the mainshock, suggesting a SW propagating rupture along the Alhama de Murcia fault. Similar oblique reverse faulting mechanism has been obtained for three largest events. Source parameters of these three earthquakes have been estimated. Horizontal ground motion was estimated at 11 city points whose local structure was known by SPAC experiments. A set of ground motion parameters (PGA, PGV, AI, CAV, SI, SA and SV) here calculated, have higher values at these points respect to the ones at LOR station. All parameter values are also above the expected values for Euro -Mediterranean earthquakes with local intensity VIII (EMS). Nevertheless, SD values are unusually short and less than the reference ones. Higher values of the response spectra of acceleration and velocity are given for periods of less than 0.7 s, with maximum spectral acceleration at 0.15 s and velocity at 0.5 s. The elastic input energy spectrum is well connected to the shake destructiveness in each place. Equivalent velocity > 60 cm/s is found in almost all sites and > 100 cm/s (for periods 0.3 to 0.6 s) in someone. Factors such as proximity, and focal mechanism and ground response characteristics explain the high ground motion parameter values obtained in Lorca sites and show the great influence of the source and site conditions on the characteristics of strong ground motion in the vicinity of the rupture. (Author) 68 refs.

Towards Horizontal Architecture for Autonomic M2M Service Networks

Directory of Open Access Journals (Sweden)

Juhani Latvakoski

2014-05-01

Full Text Available Today, increasing number of industrial application cases rely on the Machine to Machine (M2M services exposed from physical devices. Such M2M services enable interaction of physical world with the core processes of company information systems. However, there are grand challenges related to complexity and “vertical silos” limiting the M2M market scale and interoperability. It is here expected that horizontal approach for the system architecture is required for solving these challenges. Therefore, a set of architectural principles and key enablers for the horizontal architecture have been specified in this work. A selected set of key enablers called as autonomic M2M manager, M2M service capabilities, M2M messaging system, M2M gateways towards energy constrained M2M asset devices and creation of trust to enable end-to-end security for M2M applications have been developed. The developed key enablers have been evaluated separately in different scenarios dealing with smart metering, car sharing and electric bike experiments. The evaluation results shows that the provided architectural principles, and developed key enablers establish a solid ground for future research and seem to enable communication between objects and applications, which are not initially been designed to communicate together. The aim as the next step in this research is to create a combined experimental system to evaluate the system interoperability and performance in a more detailed manner.

Energy extracted from underground rock area by using a horizontal closed loop system in Mutah University/Jordan

International Nuclear Information System (INIS)

Al-Dabbas, Mohammed Awwad Ali; Al-Rousan, Ammar A.

2013-01-01

Highlights: ► The ground can be used as a storage tank to store hot or cooled water in Jordan. ► The stored energy in rocks was utilized to provide heating cooling, and hot water for homes. ► The underground geothermal horizontal loop in rocks was technically approved. ► It can extract up to six times the heat energy that used in electrical energy. ► Its low capital cost and zero environmental emissions. - Abstract: Earth Energy Systems (EESs) utilize the thermal energy that is stored in rocks and ground water under the earth’s surface to provide homes, commercial buildings, and industrial facilities with heating, cooling, and hot water. Solar energy is absorbed by the earth’s surface which stores up to 50% of the sun’s energy that radiates on it. Consequently, the earth and groundwater’s temperature is relatively constant compared to that of the surface air. The earth’s temperature is generally warmer than the surface temperature during the colder months of the year, while it is generally cooler than the surface temperature during the hot months of the year. In this study, energy was extracted from the underground rocks at Mutah University in Jordan by using the geothermal horizontal closed loop system. Two-meter holes were drilled into the earth’s surface; copper pipes were inserted for liquid to pass through them into the heat exchange system. Then, the liquid was circulated back into the ground. Several temperature differences were measured and reported in the cold and hot months. The experimental results showed that thermal energy stored in rocks can be used to provide homes with heating, cooling, and hot water with low capital cost and zero environmental emissions.

Fabrication of a Horizontal and a Vertical Large Surface Area Nanogap Electrochemical Sensor

Directory of Open Access Journals (Sweden)

Jules L. Hammond

2016-12-01

Full Text Available Nanogap sensors have a wide range of applications as they can provide accurate direct detection of biomolecules through impedimetric or amperometric signals. Signal response from nanogap sensors is dependent on both the electrode spacing and surface area. However, creating large surface area nanogap sensors presents several challenges during fabrication. We show two different approaches to achieve both horizontal and vertical coplanar nanogap geometries. In the first method we use electron-beam lithography (EBL to pattern an 11 mm long serpentine nanogap (215 nm between two electrodes. For the second method we use inductively-coupled plasma (ICP reactive ion etching (RIE to create a channel in a silicon substrate, optically pattern a buried 1.0 mm × 1.5 mm electrode before anodically bonding a second identical electrode, patterned on glass, directly above. The devices have a wide range of applicability in different sensing techniques with the large area nanogaps presenting advantages over other devices of the same family. As a case study we explore the detection of peptide nucleic acid (PNA−DNA binding events using dielectric spectroscopy with the horizontal coplanar device.

Two-phase flow through small branches in a horizontal pipe with stratified flow

International Nuclear Information System (INIS)

Smoglie, C.

1985-02-01

In the field of reactor safety the occurrence of a small break in a horizontal primary coolant pipe is of great importance. This report presents the description and results of experiments designed to determine the mass flow rate and quality through a small break at the bottom, the top or the side of a main pipe with stratified gas-liquid flow. If the interface level is far below (above) the branch, only single-phase gas (liquid) flow enters the branch. For smaller distances the interface is locally deformed because of the pressure decrease due to the fluid acceleration near the branch inlet (Bernoulli effect) and liquid (gas) can be entrained. This report contains photographs illustrating the flow phenomena as well as a general correlation to determine the beginning of entrainment. Results are presented on the branch mass flow rate and quality as a function of a normalized distance between the interface and the branch inlet. A model was developed which enables to predict the branch quality and mass flux. Results from air-water flow through horizontal branches, were extrapolated for steam water flow at high pressure with critical branch mass flux. (orig./HS) [de

106 17 Telemetry Standards Chapter 2

Science.gov (United States)

2017-07-31

frequencies at Department of Defense (DoD)-related test ranges and contractor facilities. The goal of frequency management is to encourage maximal...depends on the horizontal distance d, the altitude of the aircraft ht , and the height above ground of the AMT receive antenna, hr. Using trigonometry

Horizontal drilling in Miocene thin sand of Lake Maracaibo

Energy Technology Data Exchange (ETDEWEB)

Partidas, C. [PDVSA Exploration and Production (Venezuela)

1998-12-31

Horizontal drilling in the mature Lake Maracaibo field in Venezuela as a means of stimulating production are discussed. The Miocene sand where the horizontal well technology was applied, presented a number of intervals of unconsolidated sand of varied continuity, pay intervals at ten to twenty feet thickness, and reservoir pressures mostly at hydrostatic or below hydrostatic values. This paper evaluates a horizontal drilling program in the Lagunallis Lago Production Unit of Maracaibo, involving 91 wells to date (since 1995). When assessed in economic terms, results indicate that horizontal wells are a better economic alternative than vertical wells. The same results also showed that drainage from thin sand reservoirs resulted in better production with horizontal well technology than production from vertical wells. Payout was less than two years for 50 per cent of the horizontal wells while 40 per cent had payouts of between two and four years. Profit to investment ratio was greater than two in the case of about 70 per cent of the horizontal wells drilled in 1996. 2 tabs., 10 figs.

Distribution of 'Candidatus Liberibacter asiaticus' Above and Below Ground in Texas Citrus.

Science.gov (United States)

Louzada, Eliezer S; Vazquez, Omar Ed; Braswell, W Evan; Yanev, George; Devanaboina, Madhavi; Kunta, Madhurababu

2016-07-01

' was detected more frequently and bacterial abundances were higher among horizontally growing roots just under the soil surface (96%) than among deeper vertically growing roots (78%). Bacterial abundance declined slightly with distance from the trunk. These results point to paths of research that will likely prove useful to combating this devastating disease.

Common Gamma-ray Glows above Thunderclouds

Science.gov (United States)

Kelley, Nicole; Smith, David; Dwyer, Joseph; Hazelton, Bryna; Grefenstette, Brian; Lowell, Alex; Splitt, Michael; Lazarus, Steven; Rassoul, Hamid

2013-04-01

Gamma-ray glows are continuous, long duration gamma- and x-ray emission seen coming from thunderclouds. The Airborne for Energetic Lightning Emissions (ADELE) observed 12 gamma-ray glows during its summer 2009 flight campaign over the areas of Colorado and Florida in the United States. For these glows we shall present their spectra, relationship to lightning activity and how their duration and size changes as a function of distance. Gamma-ray glows follow the relativistic runaway electron avalanche (RREA) spectrum and have been previously measured from the ground and inside the cloud. ADELE measured most glows as it flew above the screening layer of the cloud. During the brightest glow on August 21, 2009, we can show that we are flying directly into a downward facing relativistic runaway avalanche, indicative of flying between the upper positive and negative screening layer of the cloud. In order to explain the brightness of this glow, RREA with an electric field approaching the limit for relativistic feedback must be occurring. Using all 12 glows, we show that lightning activity diminishes during the onset of the glow. Using this along with the fact that glows occur as the field approaches the level necessary for feedback, we attempt to distinguish between two possibilities: that glows are evidence that RREA with feedback, rather than lightning, is sometimes the primary channel for discharging the cloud, or else that the overall discharging is still controlled by lightning, with glows simply appearing during times when a subsidence of lightning allows the field to rise above the threshold for RREA.

Ground-water quality beneath solid-waste disposal sites at anchorage, Alaska

Science.gov (United States)

Zenone, Chester; Donaldson, D.E.; Grunwaldt, J.J.

1975-01-01

Studies at three solid-waste disposal sites in the Anchorage area suggest that differences in local geohydrologic conditions influence ground-water quality. A leachate was detected in ground water within and beneath two sites where the water table is very near land surface and refuse is deposited either at or below the water table in some parts of the filled areas. No leachate was detected in ground water beneath a third site where waste disposal is well above the local water table.

The Holy Grail of Resource Assessment: Low Cost Ground-Based Measurements with Good Accuracy

Energy Technology Data Exchange (ETDEWEB)

Marion, Bill; Smith, Benjamin

2017-06-22

Using performance data from some of the millions of installed photovoltaic (PV) modules with micro-inverters may afford the opportunity to provide ground-based solar resource data critical for developing PV projects. The method used back-solves for the direct normal irradiance (DNI) and the diffuse horizontal irradiance (DHI) from the micro-inverter ac production data. When the derived values of DNI and DHI were then used to model the performance of other PV systems, the annual mean bias deviations were within +/- 4%, and only 1% greater than when the PV performance was modeled using high quality irradiance measurements. An uncertainty analysis shows the method better suited for modeling PV performance than using satellite-based global horizontal irradiance.

Benefits of a horizontal well in sandstone waterflood